ABOUT THE ASEAN JOURNAL ON SCIENCE AND TECHNOLOGY FOR DEVELOPMENTThe ASEAN Journal on Science and Technology for Development is a refereed Journal of the ASEAN Committeeon Science and Technology (ASEAN COST). It reports on science and technology policies and programmes, andresearch activities undertaken by COST in support of social and economic development of the ASEAN membercountries.The coverage is focused but not limited to, the main areas of activity of ASEAN COST, namely, Biotechnology,Non-Conventional Energy Research, Materials Science and Technology, Marine Sciences, Meteorology andGeophysics, Food Science and Technology, Microelectronics and Information Technology, Space Applications,and Science and Technology Policy, Infrastructure and Resources Development. ABOUT THE ASEAN COMMITTEE ON SCIENCE AND TECHNOLOGYThe ASEAN Committee on Science and Technology was established to strengthen and enhance the capability ofASEAN in science and technology so that it can promote economic development and help achieve a high qualityof life for its people. Its terms and reference are: ●● To generate and promote development of scientific and technological expertise and manpower in the ASEAN region; ●● To facilite and accelerate the transfer of scientific and technological development among ASEAN countries and from more advanced regions of the world to the ASEAN region; ●● To provide support and assistance in the development and application of research discoveries and technological practices of endogenous origin for the common good, and in the more effective use of natural resources available in the ASEAN region and in general; and ●● To provide scientific and technological support towards the implementation of existing and future ASEAN projects.Information on the activities of ASEAN COST can be obtained at its website http://www.asnet.org DISCLAIMERWhile every effort is made to see that no inaccurate or misleading data, opinion or statement appears in the Journal,articles and advertisements in the Journal are the sole responsibility of the contributor or advertiser concerned. Theydo not necessarily represent the views of the Editors, the Editorial Board nor the Editorial Advisory Committee.The Editors, the Editorial Board and the Editorial Advisory Committee and their respective employees, officersand agents accept no responsibility or liability whatsoever for the consequences of any inaccurate or misleadingdata, opinion or statement. © Copyright 2013: ASEAN Committee on Science and TechnologyNo part of this publication may be reproduced, stored in a retrieval system or transmitted in any form of by any means, without permission in writing from the copyright holder.
Editorial Board Editor-in-Chief Prof Emeritus Dr Md Ikram Mohd Said School of Chemical Sciences and Food Technology,Faculty of Science and Technology, Universiti Kebangsaan MalaysiaEditorial Board MembersMalaysia Assoc. Prof Tan Tin WeeDr Ahmad Ibrahim Department of Biochemistry,Academy of Sciences Malaysia National University of SingaporeProf Abdul Halim Shaari ThailandFaculty of Science, Universiti Putra Malaysia Prof Narongrit Sombatsompop School of Energy, Environment and Materials,Prof Thong Kwai Lin King Mongkut’s University of Technology,Institute of Biological Science, Faculty of ThonburiScience/UMBIO Cluster, Institute of GraduateStudies, University of Malaya Prof Prida Wibulswas President, Shinawatra UniversityBrunei DarussalamRosita Abdullah CambodiaSenior Special Duties Officer, Pal DesMinistry of Development Vice-Rector, Royal University of Phnom PenhAssoc. Prof Zohrah Sulaiman IndonesiaDeputy Vice-Chancellor, Dr Warsito Purwo TarunoUniversiti Brunei Darussalam Minister, Special Advisor for Research and CooperationMyanmarDr Zaw Min Aung Lao PDRDirector General, Department of Technical and Kongsaysy PhommaxayVocational Education, Acting Director General,Ministry of Science and Technology Cabinet Office of the Ministry of Science and TechnologyPhilippinesDr Carol M. Yorobe Keonakhone SaysulianeUndersecretary for Regional Operations, Acting Director General,Department of Science and Technology Department of Information TechnologySingapore VietnamAssoc. Prof Ong Sim Heng Dr Mai HaDepartment of Electrical and Computer Director General,Engineering, National University of Singapore Ministry of Science and Technology
Editorial Advisory PanelBrunei Darussalam Lao PDREddie Sunny Dr Maydom ChanthanasinhDeputy Permanent Secretary, Deputy Minister, Ministry of Science andMinistry of Development Technology, National COST ChairmanMyanmar SingaporeDr Ko Ko Oo Prof Low Teck SengNational COST Chairman, National COST Chairman,Deputy Minister, Ministry of Science and Managing Director, Agency for Science,Technology Technology and ResearchCambodia ThailandDr Om Romny Assoc. Prof Weerapong PairsuwanDirector, Institute of Technology of Cambodia Deputy Permanent Secretary, Ministry of Science and TechnologyPhilippinesDr Graciano P. Yumul MalaysiaUndersecretary for R&D, Dr Noorul Ainur Mohd NurDepartment of Science and Technology National COST Chairman, Secretary General, Ministry of Science,Indonesia Technology and InnovationProf Syamsa Ardisasmita, DEADeputy Minister for Science and Technology VietnamNetwork, National COST Chairman Dr Le Dinh Tien Deputy Minister for Science and Technology, National COST ChairmanEditor/Technical Editor Kanesan SolomalaiEx-Academy of Sciences Malaysia Amirul Ikhzan Amin Zaki Academy of Sciences Malaysia Production Manager Kamariah Mohd Saidin Universiti Putra Malaysia Publisher Universiti Putra Malaysia Press
Contents ASEAN J. Sc. Technol. Dev. Volume 31(1), 2014Fabrication, Rheology and Antioxidant Activity of Palm Esters-based Emulsions 1Loaded with Tocotrienol 15 S. H. Ng, B. Mahiran and I. Zahariah 24 31Pd(II) Complexes with Nitrogen-oxygen Donor Ligands: Synthesis, 38Characterization and Catalytic Activity for Suzuki-MiyauraCross-Coupling Reaction M. T. Amalina, B. Hadariah, K. Karimah and W. I. W. NazihahCigarette Smoking among Male Teenagers in Malaysia ― A Narrative Review R. III P. DiosoForecsting of Hydrological Time Series Data with Lag-one Markov Chain Model M. A. Malek and A. M. BakiAssessment Attributes on Effective Construction Management for PropertyDevelopers in Malaysia Ayob Norizam, M.A. Malek and I. Mohamad
ASEAN J. Sci. Technol. Dev., 31(1): 1 – 14 Fabrication, Rheology and Antioxidant Activity ofPalm Esters-based Emulsions Loaded with Tocotrienol S. H. NG1*, B. MAHIRAN2 AND I. ZAHARIAH3Palm oil esters are wax esters derived from palm oil and oleyl alcohol. Palm oil esters have manyapplications due to their luxurious moisturizing properties, non-greasy and blend easily withfragrances and colours when applied on skin surface. The aim of this research was to fabricate palmesters-based emulsions cream for topical delivery, characterise the rheological properties and in vitroantioxidant activity of the palm esters-based emulsions system. Emulsions containing palm oil esters loaded with tocotrienol were obtained in two stages, withpropagation of rotor-stator at 6000 r.p.m. for 5 min and further emulsified using an ultrasound atvarious acoustic amplitudes for another 5 min. A stress/rate controlled Kinexus Rheometer with atemperature controller was used to measure the rheological properties of the emulsion. Rheologymeasurements were performed at 25.0°C ± 0.1°C with 4°/40 mm cone and plate geometry. Thein vitro antioxidant activity was investigated using UV-Vis spectrophotometer. The yield stress of the emulsions increased with increasing acoustic amplitudes. Theviscoelasticity of the emulsions were enhanced by the increase in the oil and surfactant concentrations.The emulsions with higher oil phase concentration [30% (w/w)] showed greater elasticity whichimplied strong dynamic rigidity of the emulsions. The cohesive energy increased significantly withsurfactant concentration especially for the emulsions with 30% (w/w) oil phase concentration. Thepalm oil esters emulsions containing tocotrienol gave higher Trolox equivalent antioxidant capacityvalues which implied higher antioxidant capability. The tocotrienol in emulsion with 30% (w/w) dispersed phase showed that they were the moststable with longest shelf life and exhibited greater inhibitory effects on the ABTS•+.Key words: Emulsion; rheological properties; antioxidant activity; yield stress; cohesive energy;palm oil esters; tocotrienolPalm oil is produced from the fruit of oil non-toxicity, good fat solubility propertiespalm (Elaeis guineensis) which is grown in and excellent wetting at interfaces (Radzimass plantations in tropical countries such et al. 2006) but without the greasy feelingas Malaysia, Indonesia and Nigeria. The when applied on the skin surface; these haveoil consists of 95% triglycerides and 5% attracted the attention of the industry. Thediglycerides whereby carbons of the carboxyls emollient effect of POEs had been provenrange from 10–20 with or without double thereby making this oil highly recommendablebonds (Tanaka et al. 2008). Palm oil esters for its incorporation into the topical preparation(POEs) are a constituent of modified form as oil phase. Thus, palm oil esters are excellentof palm olein oil known simply as palm oil. ingredient to be used in cosmeceutical andDesirable characteristics of fat esters including pharmaceutical formulations.1 School of Pharmacy, International Medical University, 57000 IMU Bukit Jalil, Kuala Lumpur, Malaysia2 Department of Chemistry, Faculty of Science, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia3 Sime Darby Research Sdn. Bhd Carey Island, 42960 Pulau Carey, Selangor, Malaysia* Corresponding author (e-mail: [email protected])
ASEAN Journal on Science and Technology for Development, 31(1), 2014 Nanoemulsions are emulsion with droplet stress (byproducts of cellular energy) andsize in the range 20 nm–200 nm (Solans et al. exogenous stressors (ultraviolet light, pollution,2003). They are independent of molecular size cigarette smoke etc.) (Choi & Berson 2006).of the hydrophilic solute and the nature of the Tocotrienol are fat-soluble vitamins relatedaqueous phase. In addition, nanoemulsions to the family of tocopherols. Tocopheroldelivery system was independent of animal and tocotrienol are well recognized for theirskin characteristics such as the stratum antioxidative effect (Kamal 1996). This effectcorneum thickness and the follicle-type (Wu depends primarily on the phenolic group inet al. 2001). Thus, nanoemulsions due to their the chromanol ring, rather than the side chainextremely small size are suitable to be used as (Burton & Ingold 1989). The trolox equivalentdelivery system in cosmeceuticals. However, antioxidant capacity (TEAC) assay is widelynanoemulsions are only kinetically stable applied to assess the amount of radicals thatand therefore, it is also a very fragile system can be scavenged by an antioxidant, i.e. theby nature (Tadros et al. 2004). As they are antioxidant capacity (Lien et al. 1999).transparent and usually very fluid, the slightestsign of destabilization easily appears. They The present investigation was focused onbecome opaque and creaming may be visible. the preparation of palm esters-based emulsionsThus, stability of the nanoemulsion is a critical of tocotrienol and to characterise the rheologicalfactor to be analysed. The achievement of properties of the emulsion systems. Furthermore,developing long time stability of cosmetic assessment of the in vitro antioxidant activity ofproducts (3-years shelf life) is often difficult esters-based palm was done by the TEAC assay.and deeply affects costs in the development ofnew formulations. EXPERIMENTAL Rheology is an independent scientific Materialsdiscipline: studying the deformability, and flowproperties of a matter under an applied stress or POEs was prepared in the laboratory accordingstrain is revealed by McClements (1999). Owing to the method of Keng et al. (2009) Sorbitanto the fact that rheology can give a better picture monooleate (Span® 80) and polyoxethyleneof the behaviour of a material, it is therefore (20) sorbitan monooleate (Tween®80) werewidely used as a tool to test the texture and flow purchased from Merck, Germany. The HLBbehaviour of industrial products especially in values of sorbitan monooleate (Span® 80)the processing industries such as food (Lorenzo and polyoxethylene (20) sorbitan monooleateet al. 2008), cosmetics (Bummer & Godersky (Tween® 80) are 4.3 and 15.0, respectively.1999), pharmaceuticals (Zumalacarregui Tocotrienol (Gold Tri. E 70) was from Goldenet al. 2004), polymer (Karg et al. 1985), coating Hope Bioganic, Malaysia. Xanthan gum(Kikic et al. 1979), and oil processing (Martin from Xanthomonas campestris was obtainedet al. 2006). The rheological results also enable from Fluka Chemie GmbH, France. Freshlyscientists to estimate the product’s quality such deionized water was obtained from wateras elasticity, viscosity, deformability, storage, deionizer, Mili-Q (Milipore, USA).shelf life including intermolecular interactionsdue to ultra-sensitivity at microstructure of Methodsmaterials. Preparation of emulsions containing toco- Antioxidants neutralize damaging free trienol. Emulsions were formulated using POEsradicals by quenching reactive molecules and, containing tocotrienol as dispersed oil phasethus protecting cells from both endogeneous and Mili-Q water as the continuous aqueous phase. Xanthan gum was dispersed in deionized 2
S.H. Ng et al.: Fabrication, Rheology and Antioxidant of Palm Esters-based Emulsions with Tocotrienolwater at 0.8% (w/w). Preparation of dispersed of 0.70 (± 0.02) at 734 nm and equilibrated atoil phase was performed by homogenizing 30°C (Roberta et al. 1999).5% (w/w) of surfactants into oil phase witha Polytron homogenizer (Kinematica GmbH, Diluted ABTS.+ solution (1.0 ml) (A734 nm =Germany) rotor stator. The ratio of Span® 0.700 ± 0.020) was added to 10 μl of antioxidant80:Tween® 80 was 1:4. The preparation was compounds or Trolox standards in ethanol. Thecontinued by adding the oil phase dropwise absorbance of the sample was taken at 30ºCto the aqueous solution with continuous every min after initial mixing up to 6 min. Anhomogenized at 6000 r.p.m. for 5 min. The appropriate solvent blanks were run in eachtemperature was lowered to 40°C. At 40°C, assay. All determinations were carried out threethe active ingredient was added. The emulsions times, and in triplicate, on each occasion andwere further homogenized using ultrasonic at each separate concentration of the standardcavitation for 5 min. The sonifier tip horn was and samples. The percentage inhibition ofadjusted to 2 cm below the surface of a 100 ml absorbance at 734 nm was calculated andsample. plotted as a function of concentration of antioxidants and of Trolox for the standard Rheology measurement. A stress/rate reference data (Roberta et al. 1999).controlled Kinexus Rheometer (MalvernInstrument, UK) with a temperature controller, RESULTS AND DISCUSSIONwas used to measure the rheological propertiesof the emulsion. The measurements were Rheological Properties of Emulsionsperformed at 25.0 ± 0.1°C with 4°/40 mm cone Systemand plate geometry. The samples were allowedto relax for 10 min after being loaded to the plate Steady-state flow: The sensitivity ofbefore the measurement was started. emulsions to shearing. The sensitivity of these emulsions to shearing was tested in steady- In vitro antioxidant activity. The antioxidant state flow. The greater the yield stress σY, theactivity was assessed as described below. more brittle the emulsion, and this leads toExperiments were performed on the Varian believe that the emulsion either undergoesCary 50 UV-Vis spectrophotometer (Varian, disorganization of its structure or takes longerAustralia). Trolox (2.5, 5.0, 10.0, 15.0 μM) to recover its initial states. Figures 1 and 2was prepared in ethanol. Ascorbic acid was summarize the yield stress data as a functionprepared in 18 MΩ water to a concentration of of acoustic amplitudes (%) and surfactant10.0, 15.0, 20.0 μM and α-tocopherol in ethanol concentration [% (w/w)], respectively. Theat 10.0, 15.0, 20.0 μM. ABTS, 2,2’-azinobis yield stress of the emulsions increased with(3-ethylbenzothiazoline-6-sulphonic acid) increasing acoustic amplitudes. The increasediammonium salt was dissolved in water to in acoustic amplitudes (20% to 100%) led toa 7 mM concentration. ABTS radical cation decrease in mean droplet size. The decrease(ABTS +) was produced by reacting ABTS stock of droplet size leads to the increase in the totalsolution with 2.45 mM potassium persulphate droplet surface area. When the total surface(final concentration) and allowing the mixture area of the droplet increased, the strength of theto stand in the dark at room temperature for 12 attractive force will also increase. Thus, greaterh–16 h before use. The radical was stable in this stress is required to initiate flow when highform for more than two days when stored in attractive force is holding the droplets resultingthe dark at room temperature. ABTS.+ solution high viscosity with high yield stress (Pal 1996).was then diluted with ethanol to an absorbance Mean droplet size was another factor affecting the flow behaviour of the emulsion. 3
Yield stress (Pa) 8 7 40 60 80 100 6 Amplitude (%) 5 4 3 2 1 0 20 Figure 1. The yield stress of the emulsions as a function of acoustic amplitudes and oil phase concentration. Emulsions with 10% ( ), 20% ( ) and 30% ( ) oil phase concentration.Yield stress (Pa) 10 8 6 4 2 0 4 6 8 10 Surfactant concentration [% (w/w)] Figure 2. The yield stress of the emulsions as a function of surfactant concentration. Emulsions with 10%( ), 20% ( ) and 30% ( ) oil phase concentration. 4
S.H. Ng et al.: Fabrication, Rheology and Antioxidant of Palm Esters-based Emulsions with Tocotrienol The yield stress of the emulsions increased zero shear rate the shear stress responses are notwith surfactant concentration (Figure 2) zero. This suggested that these emulsions wereindicating structural integrity arising from shear thinning non-ideal plastic-like material,the strong colloidal interaction between the with yield stress (σY) response. In other words,droplets. The yield stress is the stress that has they behaved like pseudoplastic material,to be overcome before the emulsion starts to which implied that flow can only be induced onflow (Barnes 1999). The system with higher these emulsions with the application of certainsurfactant concentration tends to form a denser minimum amount of stress called yield stress.interfacial layer, which is incompressible Figure 3 shows that above the yield stress these(Hamill & Petersen 1966). Hence, the droplets samples assume a linear shear stress—shearin such sterically stabilized system are usually rate relationship. This in turn suggested that,characterized as ‘hard sphere’ (McClements these emulsions did not follow ideal Newtonian1999). The strength of interaction forces flow behaviour even at high shear rate domain.(mainly the attractive and repulsive interactions) By contrast, the shear stress—shear ratebetween the droplets for the hard sphere system relationship increased exponentially with a(high surfactant concentration system) was certain power law exponent at low-shear raterelatively greater than the one with lower domain below yield stress, suggesting that thesurfactant concentration. In the absence of the flow behaviour of these emulsions resembledstrong sterically repulsive effect, the droplets that of plastic-like material at these low shear-in the emulsions system with lower surfactant rate domain.concentration were able to pack more efficientlyeven at low shear. Therefore, the droplets were As far as the effect of concentration on yieldaligning themselves easily with the shear field to stress was concerned, these profiles suggestedinitiate flow. This explained that the increase in that yield stress increased monotonically withsurfactant concentration led to increase in yield surfactant concentration. This in turn indicatedstress of emulsion system. that all samples examined here exhibited non-Newtonian model type fluid behaviours, Oil phase concentration in an emulsion implying that the viscoelastic force dominatedsystem is another factor affecting the flow over the elastic force, and that the emulsionsbehaviour (Akhtar et al. 2005). The attractive under investigation underwent structuralforce is one of the colloidal interactions deformation with shear rate irrespective ofwhich play an important role in the increase surfactant concentration. The increase inin viscosity and yield stress. The magnitude the yield stress as a function of surfactantof viscosity and yield stress depend on the concentration further indicated that emulsionsstrength of the attractive force between the with higher surfactant concentration possessdroplets (Pal 1996). Higher strength of attractive higher degree of material structuring as opposedforce between the droplets leads to increase in to lower surfactant concentration. This alsoviscosity and yield stress. means that emulsions with higher surfactant concentration offer a larger resistance toShear Stress versus Shear Rate Profile external force before they started flowing. This in turn suggested that emulsions stabilizedThe shear stress—shear rate profile of stabilized with higher surfactant concentration undergoemulsions are depicted in Figure 3. Much like a greater degree of deformation under appliedviscosity—shear rate profile, the rate of change shear in comparison to emulsions stabilizedof shear stress depends largely on the rate of with lower surfactant concentration.change of shear rate. As depicted in Figure 3, at 5
Shear stress (Pa) Shear rate (s-1)Shear stress (Pa) (a)Shear stress (Pa) Shear rate (s-1) (b) Shear rate (s-1) (c)Figure 3. Effect of shear rate of emulsions on the shear stress for (a) 10% (b) 20% (c) 30% oil phase concentration. Surfactant concentration: 5% ( ); 6% ( ); 7% ( ); 8% ( ); 9% ( ) and 10% ( ). 6
S.H. Ng et al.: Fabrication, Rheology and Antioxidant of Palm Esters-based Emulsions with TocotrienolOscillatory Measurements: Strain Sweep system. Since the strength of the interdropletProfile interactions corresponded to the mean separation distance between the droplets, theA critical strain (γc) is the maximum applied highly packed emulsion system will thereforestrain where the emulsion still gives a linear has greater interdroplet interaction forces. Theresponse to shear stress with constant elastic high interdroplet interaction strength was ablemodulus. The critical strain, γc of emulsions to hold the droplets and withstand the largein different oil phase concentration is shown deformation forces applied during the strainin Figure 4. The γc of the emulsions increased sweep test.with the oil volume fraction and surfactantconcentration. The γc was increased 50%, The strain sweep profiles also provided46% and 86% as the surfactant concentration information about the elastic component of thewas increased from 5% to 10% (w/w) for emulsions. Figures 5 and 6 show increasingemulsions with 30%, 20% and 10% (w/w) oil trends in the elastic modulus (G′) of thephase concentration, respectively. On the other emulsions with surfactant and oil concentrationhand, the γc increased more than 100% when indicating that the interactions between dropletsthe oil concentration was increased from 10% are relatively strong. A trend of increasingto 30% (w/w). elastic modulus accompanying the increased of γc was observed. The cohesive energy (Ec) The increase of critical strain of emulsion within the linear viscoelastic regime for whenwith 30% (w/w) oil phase concentration when G′ is in phase with the applied strain amplitudethe surfactant concentration was increased can also be obtained (Bossard et al. 2007), asimplied that the highly packed droplets have shown below:developed a strong structure due to the highinterdroplet interaction between the droplets (1)which corresponded to the droplet sizeand droplet concentration of the emulsionsCritical strain (γc) 35 30 25 6 78 9 10 20 Surfactant concentration [% (w/w)] 15 10 5 0 5Figure 4. The critical strain, γc of the emulsions as a function of surfactant concentration. Emulsions with 10% ( ), 20% ( ) and 30% ( ) oil phase concentration. 7
Elastic modulus, G’ (Pa) Shear strain (%)Elastic modulus, G’ (Pa) (a)Elastic modulus, G’ (Pa) Shear strain (%) (b) Shear strain (%) (c)Figure 5. The linear viscoelastic region of the emulsions with a series of surfactant concentration [5% ( )]; [6% ( )]; [7% ( )]; [8% ( )]; [9% ( )] and [10% ( )] for (a) 10%, (b) 20% and (c) 30% oil phase concentration. 8
S.H. Ng et al.: Fabrication, Rheology and Antioxidant of Palm Esters-based Emulsions with Tocotrienol When σ equals G′ in the linear viscoelastic phase concentration. Ec was low for emulsionregion, the cohesive energy is defined as: with 5% (w/w) surfactant concentration in 10% (w/w) oil phase concentration as the (2) elasticity was low (Figure 6). The higher the cohesive energy, the more stable a system was Tadros (2004) explained that the cohesive as the elastic strength was basically a measureenergy was related to the structure of the of the strength of the internal structure. This inemulsion system, which correlated to the droplet turn demonstrated that the emulsion samplessize and number of contact area between the under examination were stable systems, anddroplets. The droplet concentration and the that the stability of these emulsions systems waspacking of the droplets influenced the strength enhancing with decreasing droplet size.of the cohesive force. As discussed before,the number of droplets was increased as the Figure 7 show that the cohesive energyoil concentration was increased from 10% to increased significantly with surfactant30% (w/w) at fix surfactant concentration. As concentration especially for the emulsionsa result, the number of contacts area within with 30% (w/w) oil phase concentration.the droplets increased. Thus, increases in the The dramatic increase of cohesive force wascohesive energy of the emulsions system were due to the highly packed systems related toobserved. the interdroplet interactions that had been previously discussed. Ec ranged from a low 0.13 J/m3 for emulsionwith 5% (w/w) surfactant concentration in In vitro Antioxidant Activity10% (w/w) oil phase concentration to a highof 15.88 J/m3 for emulsion with 10% (w/w) The concentration-response curve forsurfactant concentration in 30% (w/w) oil six sequentially and separately prepared stock standards of Trolox was illustrated inElastic modulus, G’ (Pa) 45 40 35 2 4 6 8 10 12 30 Surfactant concentration [% (w/w)] 25 20 15 10 5 0 0Figure 6. The elastic modulus of the emulsions as a function of surfactant concentration. Emulsions with 10% ( ), 20% ( ) and 30% ( ) oil phase concentration. 9
ASEAN Journal on Science and Technology for Development, 31(1), 2014Ec (Jm–3) 16 14 12 24 68 10 12 10 Surfactant concentration [% (w/w)] 8 6 4 2 0 0 Figure 7. The cohesive energy of the emulsions as a function of surfactant concentration and oil concentration. Emulsions with 10% ( ), 20% ( ) and 30% ( ) oil phase concentration.Figure 8. Trolox, the water-soluble analogue and 10% dispersed phase emulsion containingof α-tocopherol was known for its high tocotrienol (15 μM) with ABTS + within 6radical scavenging activity and was therefore min. The absorption at wavelength 734 nm forfrequently used as a model compound. It was ABTS + radical cation was 0.73 followedcommonly used as a reference antioxidant, by ABTS + radical cation in ascorbic acidin which the radical scavenging activity was and tocopherol which gave 0.42 and 0.28,expressed as Trolox equivalents. The higher respectively. From the results, 30% dispersedthe concentration of Trolox used, the more the phase emulsion containing tocotrienol (15 μM)absorbance of ABTS radicals was suppressed. revealed better antioxidant properties byThe selected absorption wavelength was at 734 presenting lower absorbance value as comparednm because ABTS + has maximum absorption the standard reference compound, Trolox.at 734 nm and most antioxidant does not The extent of inhibition of the absorbanceabsorb light at 734 nm. Figure 9 illustrates of the ABTS + was plotted as a functionthe effects of the duration of interaction of of concentration in order to determine thespecific antioxidants on the suppression of TEAC that can be assessed as a functionthe absorbance of the ABTS + radical cation of time. The dose-response curve obtainedat 734 nm for Trolox, the standard reference by analysis of a range of concentrations ofcompound, compared with α-tocopherol, antioxidant compounds and Trolox standardsascorbic acid and emulsion samples containing was plotted as the percentage inhibition of thetocotrienol. absorbance of the ABTS + solution as a function of concentration of antioxidant (Figure 10). The results demonstrated that the reaction The result showed that 30% dispersed phasewith ABTS + was completed after 1 min. 30% emulsion containing tocotrienol (15 μM) has andispersed phase emulsion containing tocotrienol inhibitory effect, a maximum concentration of(15 μM) has minimum absorption than in 20% 20 μM reducing ABTS + by about 93%. 10
Inhibition [%]S.H. Ng et al.: Fabrication, Rheology and Antioxidant of Palm Esters-based Emulsions with Tocotrienol 100 90 80 70 60 50 40 30 20 10 0 0 2.5 5 10 15 20 Trolox [μM] Figure 8. Concentration-response curve for the absorbance at 734 nm for ABTS as a function of concentration of standard Trolox solution.Absorbance 0.9 0.8 0.7 23456 0.6 Time (min) 0.5 0.4 0.3 0.2 0.1 0 0 Figure 9. Effects of time on the suppression of the absorbance of the ABTS ; ABTS ( ); ABTS + ascorbic acid ( ); ABTS + tocopherol ( ); ABTS + Trolox ( ); ABTS + 10% disperse phase containing tocotrienol ( ); ABTS + 20% disperse phase containing tocotrienol ( ) and ABTS + 30% disperse phase containing tocotrienol ( ). The concentration of the samples used in the determination is 15 μM. From the result, 20% dispersed phase effect on the ABTS + since 20 μM of 20%emulsion containing tocotrienol (15 μM) dispersed phase emulsion containing tocotrienolappears to exert a slightly greater inhibitory (15 μM) and 10% disperse phase emulsioneffect on the ABTS + than on that of 10% containing tocotrienol (15 μM) only produceddispersed phase emulsion. The presence of 87.5% and 82.8% inhibition; respectivelythe 30% dispersed phase emulsion containing of the ABTS assay system. The antioxidanttocotrienol (15 μM) enhanced its inhibitory activity could be expressed in terms of the 11
ASEAN Journal on Science and Technology for Development, 31(1), 2014total contribution to the antioxidant activity TEAC at the specific time points, 1 min, 4 minover the time range studied by calculating the and 6 min (Figure 11).TEAC, the gradient of the plot of the percentageinhibition of absorbance vs. concentration plot From the results, it was found that allfor the antioxidant in question is divided by the samples tested were able to scavenge ABTS +gradient of the plot for Trolox. This gives the radical cation. Their antioxidant activities % Inhibition 100 90 80 10 15 20 Concentration (μM) 70 60 50 40 30 20 10 0 0 Figure 10. Effects of concentration of the antioxidant on the inhibition of the ABTS ; ABTS + ascorbic acid ( ); ABTS + tocopherol ( ); ABTS + Trolox ( ); ABTS + 10% dispersed phase containing tocotrienol ( ); ABTS + 20% dispersed phase containing tocotrienol ( ) and ABTS + 30% dispersed phase containing tocotrienol ( ). The concentration of the samples used in the determination is 15 μM.TEAC (TE) 2.5 2.0 1.5 1.0 0.5 00 1 4 6 Time (min) Figure 11. Profile of the variation of gradient of the percent inhibition vs. concentration plot of each antioxidant at 1, 4 and 6 min: ABTS + ascorbic acid ( ); ABTS + tocopherol ( ); ABTS + Trolox ( ); ABTS + 10% dispersed phase containing tocotrienol ( ); ABTS + 20% dispersed phase containing tocotrienol ( ) and ABTS + 30% dispersed phase containing tocotrienol ( ). The concentration of the samples used in the determination is 15 μM. 12
S.H. Ng et al.: Fabrication, Rheology and Antioxidant of Palm Esters-based Emulsions with Tocotrienolmeasured at 6 min and expressed as the TEAC Barnes, HA 1999, ‘The yield stress – everythingvalue or IC50 were relatively low as compared to flows?,’ Journal of Non-Newtonian FluidTrolox. The higher TEAC values implied higher Mechanics, vol. 81, pp. 133–178.antioxidant capability. The TEAC at 6 minof 30% dispersed phase emulsion containing Basri, MR, Salleh, M, Ariff, AB, Mohammad, BA,tocotrienol (15 μM) was 2.00 whereas the Abdul Rahman, RMB & Rahman, RNZ 2006,TEAC values of tocopherol and ascorbic acid ‘Optimization study of large-scale enzymaticwere 1.64 and 1.42 respectively. Tocotrienol synthesis of oleyl oleate, a liquid fat esters byin 30% dispersed phase appeared to have a response surface methodology’, Journal ofmuch higher TEAC value than tocopherol Chemistry Technology Biotechnology, vol. 81,and ascorbic acid in 15 μM concentrations, pp. 374–380.respectively. This means that tocotrienol canbe qualified as the best antioxidant compared Bossard, F, Moan, M & Aubry, T 2007, ‘Linearto tocopherol and ascorbic acid with the TEAC and non-linear viscoelastic behaviour of veryassay. concentrated plate-like kaolin suspensions’, Journal of Rheology, vol. 51, no. 6, pp. 1253– CONCLUSIONS 1270.The results obtained in the present work showed Bummer, R & Godersky, S 1999, ‘Rheologicalthat emulsions containing palm esters-based as studies to objectify sensations occurring whenoil phase was a suitable carrier system for the cosmetic emulsions are applied to the skin’,incorporation of tocotrienol with reasonably Colloids and Surfaces A: Physicochemical andhigh values of yield stress, suggesting the Engineering Aspects, vol. 152, pp. 89–94.stabilization of emulsions. In vitro antioxidantactivity using TEAC assay was applied to Burton, GW & Ingold, KU 1989, ‘Vitamin E as inassess the total amount of radicals that could vitro and in vivo antioxidant’, Ann. New Yorkbe scavenged by antioxidant samples. The Academy Science, vol. 570, pp. 7–22.findings indicated that tocotrienol in emulsionwith 30% (w/w) dispersed phase exhibited Choi, CM & Berson, DS 2006, ‘Cosmeceuticals’,greater inhibitory effects on the ABTS·+. Results in Seminars in Cutaneous Medicine and Surgery,were encouraging and it substantiated the role vol. 25, no. 3, pp. 163–168.of palm esters-based emulsions containingtocotrienol as an effective antioxidant therapy. Hamill, HD & Petersen, RV 1966, ‘Effects of aging and surfactant concentration on the rheology ACKNOWLEDGMENTS and droplet size distribution of a nonaqueous emulsion’, Journal of Pharmaceutical Sciences,We acknowledge the financial support from vol. 55, pp. 1268–1277.University Putra Malaysia. Kamal, EA 1996, ‘The chemistry and antioxidant Date of submission: June 2014 properties of tocopherols and tocotrienols’, Lipids, vol. 31, pp. 671–701. Date of acceptance: October 2014 Karg, RF, Boozer, CE & Benefield, RE 1985, REFERENCES ‘Injection molding of elastomers’, Rubber World,Akhtar, M, Stenzel, J, Murray, BS & Dickinson, E vol. 192, pp. 14–19. 2005, ‘Factors affecting the perception of Keng, PS, Basri, M, Zakaria, MRS, Abdul Rahman, creaminess of oil-in-water emulsions’, Food MB, Ariff, AB, Abdul Rahman, RNZ & Salleh, Hydrocolloids, vol. 19, pp. 521–526. AB 2009, ‘Newly synthesized palm esters for cosmetics industry’, Industrial Crops and Products, vol. 29, pp. 37–44. Kikic, I, Lapasin, R, Torriano, G & Papo, A 1979, ‘Processing intermediates for high-build paints’, Journal of Coatings Technology, vol. 51, pp. 29–33. Lien, EJ, Ren, S, Bui, HH & Wang, R 1999, ‘Quantitative structure activity relationship analysis of phenolic antioxidants’, Free Radical Biology and Medicine, vol. 26, pp. 285–294. 13
ASEAN Journal on Science and Technology for Development, 31(1), 2014Lorenzo, G, Zaritzky, N & Califano, A 2008, Solans, C, Esquena, J, Forgiarini, AM, Morales, D, ‘Modelling rheological properties of low-in-fat Izquierdo, P, Azemar, N & Garcia-Celma, MJ o/w emulsions stabilized with xanthan/guar 2003, ‘Nanoemulsions: formation, properties and mixture’, Food Research International, vol. 41, applications’, Surfactant Science Series, vol. 109, pp. 487–494. pp. 525–554.Martin-Alfonso, MJ, Martinez-Boza, F, Partal, P Tadros, T, Izquierdo, P, Esquena, J & Solans, C 2004, & Gallegos, C 2006, ‘Influence of pressure and ‘Formation and stability of nano-emulsions’, temperature on the flow behaviour of heavy fuel Journal of Colloid and Interface Science, vol. oil’, Rheologcal Acta, vol. 45, pp. 357–365. 108–109, pp. 303–318.McClements, DJ 1999, Emulsion rheology in food Tanaka, R, Hirose, S & Hatakeyama, H 2008, emulsions: principles, practice and techniques, ‘Preparation and characterization of polyurethane CRC Press, Boca Raton, FL. foams using a palm oil-based polyol’, Bioresource Technology, vol. 99, pp. 3810–3816.Pal, R 1996, ‘Rheology of emulsions containing polymeric liquids’, in Encyclopedia of Emulsion Wu, H, Ramachandran, C, Weiner, N & Roessler, Technology, Marcel Dekker, New York. B 2001, ‘Topical transport of hydrophilic compounds using water-in-oil nanoemulsions’,Roberta, R, Nicoletta, P, Anna, P, Ananth, P, Min, International Journal of Pharmaceutics, vol. 22, Y & Catherine, RE 1999, ‘Antioxidant activity pp. 63–75. applying an improved ABTS radical cation decolourization assay’, Free Radical Biology Zumalacarregui, L, Vazquez, M, Estevez, T, and Medicine, vol. 26, pp. 1231–1237. Aguilera, A & Hardy, E 2004, ‘Rheological studies of interferon creams’, Applied Rheology, vol. 14, pp. 251–255. 14
ASEAN J. Sci. Technol. Dev., 31(1): 15 – 23 Pd(II) Complexes with Nitrogen-oxygen Donor Ligands: Synthesis, Characterization and CatalyticActivity for Suzuki-Miyaura Cross-coupling Reaction M. T. AMALINA1, B. HADARIAH1*, K. KARIMAH1 AND W. I. W. NAZIHAH1Inexpensive bidentate Schiff base ligands (O1, O3) and their Pd(II) complexes (OPd1, OPd3) weresuccessfully synthesized and characterized using CHN elemental analysis, FTIR, 1H and 13C NMR,melting point determination, molar conductivity and magnetic moment. It revealed that these Schiffbases behaved as bidentate ligands in their complexes. The spectral data indicated that the ligandsco-ordinated through the phenolic oxygen and the azomethine nitrogen atoms. Magnetic momentdata suggested the existence of square planar Pd(II) complexes, while non-electrolytic behaviourindicated the absence of counter ions in chloroform. The Pd(II) complexes showed good catalyticactivities for Suzuki-Miyaura cross-coupling reaction between iodobenzene with phenylboronicacid at 1.0 mmol% catalyst loading.Key words: Bidentate Schiff base; nitrogen-oxygen donor ligands; Pd(II); Suzuki-Miyaura cross-coupling reaction; synthesis; physicochemical properties; catalytic activity; characterizationSchiff base ligands are considered ‘privileged Schiff base ligands are able to co-ordinateligands’ and are attractive because they are many different metals (Osman 2006; Sallameasily prepared by the condensation between 2006) and to stabilize them in various oxidationaldehyde/ketone and imines both of which states. The Schiff base complexes have beenare relatively cheap and easily available. used in catalytic reactions (Dhara et al. 2010;Stereogenic centres or other elements of Tamizh & Karvembu 2012) and as models forchirality such as planes and axes can be biological systems (Singh et al. 2012; Mohamedintroduced in the synthetic design (Cozzi 2004) et al. 2010). Many Schiff base complexesas well as benzene rings containing electron show excellent catalytic activity in variousdonating or withdrawing substituents. The reactions at high temperature (>100°C) and inmono- , di- , tri- and multi-dentate chelating the presence of moisture (Gupta & Sutar 2008).Schiff base ligands can be designed accordingto the binding environments of metal ions. The Suzuki-Miyaura cross-couplingThe metal complexes of chiral Schiff base reaction is a powerful method for the synthesisligands showed stereoselectivity in organic of biaryl bonds. The importance of biaryl unitstransformation, hence the synthesis of chiral as molecular components in pharmaceuticals,complexes become an important area of current herbicides and natural products, as well asresearch in co-ordination chemistry (Gupta & in engineering materials such as conductingSutar 2008). polymers, molecular wires and liquid crystals,1 Faculty of Applied Sciences, Universiti Teknologi MARA, 40450 Shah Alam, Selangor, Malaysia* Corresponding author (e-mail: [email protected])
ASEAN Journal on Science and Technology for Development, 31(1), 2014has attracted enormous interest (Paul & corrections were calculated from GuoyClark 2003). Numerous variants (Gillis & method. Molar conductance measurements ofBurke 2009), optimizations and applications freshly prepared Schiff base ligands and their(McGlaken & Fairlamb 2009) have been transition metal complexes solutions weredisclosed in the literature. The robust nature determined in chloroform (∼10–3 M) at roomof this reaction has led to its widespread use temperature using a Mettler Toledo Inlab 730in the pharmaceutical industry (Torborg & conductivity meter. The formation of productsBeller 2009). The relative thermal stability, from catalytic testing was monitored using Gasinsensitivity to air or moisture, and low toxicity Chromatography (GC) technique (Bhunia et al.(Miyaura & Suzuki 1995) of boronic acid 2010). Yields were calculated for a specific setconstitute a highly valuable practical advantage of parameters at a specific time according to thefor both academic and industrial applications. product ratios. As a part of our interest in designing Synthesis of Schiff base ligands.new, inexpensive ligands and studyingtheir co-ordination behaviour and catalyticapplication, we report herein the synthesis andcharacterization of a new type of ligands andtheir Pd(II) complexes as catalysts in Suzuki-Miyaura cross-coupling reaction. MATERIALS AND METHODS Figure 1. General reaction for the synthesis of Ovan-series ligands.Experimental Sections Synthesis of (E)-2-[(benzylimino)methyl]-6- Materials. All reagents and chemicals methoxyphenol [O1]used in this investigation were laboratory puregrade available from Acros, Merck and Sigma- To o-vanillin (50 mmol, 7.6091 g) was dissolvedAldrich. The solvents for the spectral study were in ethanol (25 ml), an ethanolic solution ofspectroscopic grade and used without further benzylamine (50 mmol, 5.3869 g) was addedpurification. and the mixture was stirred for overnight. The ethanol was allowed to evaporate slowly Techniques. Microanalyses for carbon, at room temperature. Orange-coloured solidhydrogen and nitrogen were determined using product was evident after a week. The solida Thermo Finnigan Flash Elemental Analyzer residue was filtered, washed with ice-cold2000. The IR spectra were obtained on a ethanol and air-dried at room temperature. ThePerkin Elmer 1750X FTIR spectrophotometer yield was 36.8%.(4000 cm–1 – 400 cm–1) with samples preparedas KBr pellets. Melting points of the products Synthesis of (E)-2-methoxy-6-[(4-methoxy-were determined using Buchii-B454 and are benzylimino)methyl]phenol [O3]uncorrected. Proton (1H) and carbon (13C) NMR(300 MHz) spectra were recorded on a Bruker To o-vanillin (2 mmol, 0.3075 g) was dissolvedVarian spectrometer in CDCl3 and reported in ethanol (5 ml), an ethanolic solution ofin p.p.m. (δ) from the internal standard TMS. 4-methoxybenzylamine (2 mmol, 0.2744 g)The magnetic susceptibilities were determined was added dropwise and the mixture was heatedon Sherwood Auto Magnetic Susceptibility under reflux for 2 h. Upon cooling, there wasBalance at room temperature (25°C) usingHg[Co(SCN)4] as a calibrant; the diamagnetic 16
Amalina et al.: Synthesis and Characterization of a New Type of Ligands and their Pd(II) Complexesno formation of solid materials. Ethanol was General reaction of Suzuki-Miyaura cross-removed using rotary evaporator. The ligand coupling reaction. The palladium(II) Schiffwas used in complexation with Pd(II) metal salt. base complexes were tested as homogeneousSynthesis of Pd(II) complexes. catalysts in a series of Suzuki-Miyaura cross- coupling reaction, between iodobenzene and Figure 2. General reaction for the synthesis of phenylboronic acid to produce biphenyl. The Pd-Ovan-series complexes. general procedure (Figure 1) is as follows: Iodobenzene (1 mmol), phenylboronic acid (2 mmol), triethylamine, Et3N (2.4 mmol), palladium(II) Schiff base (0.01 mmol) and solvent DMA (7 ml) were mixed in Radley’s 12-placed reaction carousel and refluxed whilst being purged with nitrogen. The reaction was monitored every 6 h and sampling was done at 6 h, 12 h and 24 h.Synthesis of Bis(2-((E)-(benzylimino)methyl)- Figure 3. Catalytic reaction of iodobenzene with6-methoxyphenoxy)palladium(II) [OPd1] phenylboronic acid.The ligand, O1, (5 mmol, 1.2064 g) was RESULTS AND DISCUSSIONdissolved in acetonitrile (10 ml) in a round-bottomed flask. Palladium(II) acetate Physicochemical Properties of the(2.5 mmol, 0.5612 g) was dissolved separately Synthesized Compoundsin acetonitrile (10 ml) and added into the flaskcontaining the ligand solution. The mixture was All of these bidentate Schiff base ligandsstirred and refluxed for 4 h upon which brown and their Pd(II) complexes were intenselysolids were formed. It was isolated by gravity coloured, air and moisture free. The ligandsfiltration, washed with ice-cold acetonitrile and their metal complexes were very stableand air dried at room temperature. The yield solids at room temperature, without undergoingwas 90.6%. decomposition. Yields of the complexes were higher than those of the ligands. The ligandsSynthesis of Bis(2-methoxy-6-((E)-(4- had very high solubility in almost all polarmethoxybenzylimino)methyl)phenolato) solvents attributable to their polar nature. Thepalladium(II) [OPd3] complexes however, had very low solubility in polar organic solvents such as Et3OH,The ligand, O3, (2 mmol, 0.5426 g) was MeOH, DMSO, CH2Cl2, etc. but soluble indissolved in acetonitrile (5 ml) in a round- relatively less polar CHCl3. These synthesizedbottomed flask. Palladium(II) acetate (1 ligands contained both polar and non-polarmmol, 0.2246 g) was dissolved separately in groups such as -OH, -OCH3, -CH3 etc. Theacetonitrile (5 ml) and added into the flask C, H and N percentages were theoreticallycontaining the ligand solution. The mixture was calculated and the measured values were instirred and refluxed for 4 h upon which a brown accordance to the suggested formula. Thesolid was formed. It was isolated by gravity physical and analytical data of the Schiff basefiltration, washed with ice-cold acetonitrile ligands and their complexes are shown inand air dried at room temperature. The yield Table 1.secured was 80.8%. 17
ASEAN Journal on Science and Technology for Development, 31(1), 2014 Table 1. Physical and analytical data for ovan-series ligands and their complexes.Ligand/ Empirical Colour Melting point Elemental Analysis (%) (Found)Complex formula (°C) C HN Yellow 74.67 (74.77) 6.27 (6.31) 5.81 (5.91) O1 C15H15NO2 Brown 62–65 61.39 (61.47) 4.81 (4.79) 4.77 (4.74) OPd1 C30H28N2O4Pd Yellow 259–261 70.83 (71.08) 6.32 (6.32) 5.23 (5.23) Brown 59.40 (59.12) 4.98 (4.99) 4.33 (4.35) O3 C16H17NO3 – OPd3 C32H32N2O6Pd 204–205IR Spectral Studies of electron density from the nitrogen atom owing to co-ordination (Zolezzi et al. 1999).In general, all infrared spectra presented the A similar effect was observed in the stretchingsame general characteristics. The appearance vibration of the Schiff base phenolic C-O andof the C=N (azomethine) peaks in the range methoxy groups, with respect to the same1620–1634 cm–1 could be clearly seen in the group in the complexes where it was shiftedspectra, indicating the formation of the Schiff to a lower frequency, strongly indicatingbases. The broad band at 2300 cm–1–3300 cm–1 oxygen co-ordination to the metal centre. Thecould be attributed to the intramolecular appearance of new bands at 462 cm–1–544 cm–1hydrogen-bonded O-H group (Zolezzi et al. and 581 cm–1–660 cm–1, that ascribed Pd-O1999). This band was absent in the spectra of and Pd-N vibrations, support the evidence ofcomplexes due to deprotonation of the phenolic the participation of the nitrogen atom of themoiety upon complexation. The Pd(II) ion azomethine group and oxygen atom of the ofwas co-ordinated through the nitrogen and OH group of the ligand in the complexationoxygen atoms of the hydroxyl group. The with metal ions (Ouf et al. 2010; Mustafa et al.azomethine C=N bands were seen to be shifted 2009). The significant bands of ligands andto lower frequencies, 1612 cm–1–1623 cm–1 in their Pd(II) complexes and their spectra areall Pd(II) complexes due to the withdrawal summarized in Table 2 and Figure 4. Transmitance (%T) Wavenumber (cm–1) OPd1 O1 O3 OPd3 Figure 4. FTIR Spectra of O1, O3, OPd1 and OPd3. 18
Amalina et al.: Synthesis and Characterization of a New Type of Ligands and their Pd(II) Complexes Table 2. Infrared data for ligands and their Pd(II) complexes.Ligand/ Frequency (cm-1)Complex ν(C=N) ν(C–N) ν(C–O) ν(OCH3) ν(C-OH) ν(M–O, M–N) O1 1634(s) 1344(w) 1254(s) 1054(w) 2300–3300(b) –OPd1 1622(s) 1316(s) 657 416(w) 1630(w) 1344(w) 1241(s) 1095(w) – O3 1620(s) 1320(s) –OPd3 1251(s) 1033(w) 2500-3200(b) 567 515(w) 1239(s) 1032(w) –(s) = Strong; (b) = Broad; (w) = Weak.1H and 13C NMR Studies disappeared upon complexation, indicating that the complexation was successfullyIn the 1H NMR of the ligands (Table 3), achieved through deprotonation of the phenol.the chemical shift for methylene appear at The OH peak in O3 that was expected to appear4.74 p.p.m.–4.82 p.p.m. as singlets and slightly in the downfield region (10 p.p.m.–14 p.p.m.)shifted to higher values of 5.04 p.p.m.– (Saheb & Sheikhshoaie 2011) of the spectra5.12 p.p.m. in their respective Pd(II) complexes. was not observed as the labile phenolic protonThe methoxy peaks for ligands appear at may have undergone a rapid exchange with the3.88 p.p.m.–3.90 p.p.m. while in complexes, deuterium in the solvent.they appear at 3.75 p.p.m.–3.76 p.p.m., slightlyshifted to lower values. Upon co-ordination, The 13C singlet signals for the imine carbonsthere is an upfield shift of peaks for azomethine (C=N) in complexes are found in the regionprotons from 8.38 p.p.m.–8.42 p.p.m. to 162.3 p.p.m.–162.8 p.p.m. (Table 4). This is an7.69 p.p.m.–7.72 p.p.m.. This upfield shift upfield shift from 165.2 p.p.m.–165.6 p.p.m.is attributed to the conformational change observed for the free ligands, further affirmingthat occurs in the ligand upon chelation the co-ordination of the ligand through the(Mahamo et al. 2012). The phenolic imine group to the metal centre. There isproton appears at 13.85 p.p.m. in O1 and Table 3. Chemical shift of 1H NMR for ligands and their Pd(II) complexes.Assignments Chemical shifts (p.p.m.) O1 OPd1 O3 OPd3 C-CH2 4.82(s) 5.12(s) 4.74(s) 5.04(s) N=CH 8.42(s) 7.72(s) 8.38(s) 7.69(s) C3-H (Ar) 6.84–6.89(d) 6.76–6.81(d) 6.92–6.93(d) 6.78–6.79(d) C4-H (Ar) 6.81–6.84(t) 6.47–6.52(t) 6.86–6.89(t) 6.83–6.84(t) C5-H (Ar) 6.89–6.91(d) 7.26–7.29(d) 7.21–7.24(d) 7.36–7.39(d) C13-H (Ar) 6.91–7.26(t) 7.29(t)C11,C15-H (Ar) 7.32(d) 7.44–7.46 (d) – –C12, C14-H (Ar) 7.26–7.32(t) 7.22–7.26(t) 6.76–6.79(d) 6.47–6.52(d) C13-OCH3 7.29–7.30(d) 6.77–6.86(d) Ar-OCH3 – – C1-OH 3.90(s) 3.75(s) 3.79(s) 3.77(s) 13.85(b) 3.88(s) 3.76(s) – N.D. –(s) = Singlet; (d) = Doublet; (t) = Triplet; (b) = Broad; N.D. = Not detected; Ar = Aromatic. 19
ASEAN Journal on Science and Technology for Development, 31(1), 2014Table 4. Chemical shift of 13C NMR for ligands and their Pd(II) complexes.Assignments Chemical shifts (p.p.m.) O1 OPd1 O3 OPd3 C-CH2 62.68(s) 58.85(s) 64.40(s) 58.33(s) N=CH 165.6(s) 162.8(s) 165.2(s) 162.3(s) C3-H (Ar) 113.9(s) 114.0(s) 114.0(s) 113.8(s) C4-H (Ar) 117.9(s) 120.2(s) 117.8(s) 113.8(s) C5-H (Ar) 122.9(s) 125.4(s) 122.9(s) 125.4(s) C13-H (Ar) 127.3(s) 127.1(s) 158.8(s) 158.8(s)C11,C15-H (Ar) 127.5(s) 127.1(s) 129.9(s) 129.8(s)C12, C14-H (Ar) 128.6(s) 128.4(s) 114.2(s) 114.0(s) C13-OCH3 55.30(s) 55.24(s) Ar-OCH3 – – 56.04(s) 55.95(s) C1-OH 56.01(s) 55.90(s) 151.9(s) 151.7(s) – –(s) = Singlet; Ar = Aromatic.also an upfield shift from 62.68 p.p.m.–64.40 iodobenzene with phenylboronic acid in thep.p.m. to 58.33 p.p.m.–58.85 p.p.m. and from presence of triethylamine (Et3N) as base in56.01 p.p.m.–56.04 p.p.m. to 55.90 p.p.m.– N,N-dimethylacetamide (DMA) at 100°C.55.95 p.p.m. with respect to the free ligand Et3N that is soluble in the reaction mixturein the signals for the methylene and methoxy was a good base for the reaction due to itscarbons, respectively, upon co-ordination to capability to give high conversion, althoughthe metal centre as per reported by Mahamo in its presence trace quantities of palladiumet al. (2012) and Dilworth et al. (1994). In metal could occasionally be observed as athe free ligands, C-OH signals appear at precipitate against the walls of the glass tubes.151.7 p.p.m.–151.9 p.p.m. (Şenol et al. 2011)and disappeared upon complexation where the In most of the cases, Et3N was the base ofphenolic moiety was deprotonated. choice to activate the boron species in order to increase its nucleophilicity and give a cleanMolar Conductance and Magnetic Moment reaction. This is because the organoborons compounds are highly covalent in characterThe molar conductance values of the Pd(II) (Matos & Soderquist 1998). Solubility of thecomplexes was found to be 0 Ω–1 cm2 mol–1 bases plays a great rule in Suzuki-Miyaurasuggesting their non-electrolytic nature (Ben- coupling reaction (Papp et al. 2006).Saber et al. 2005). The magnetic moment ofthe complexes revealed their diamagnetic The reaction was monitored using GC-FIDnature where μeff = 0, consistent with the by percentage conversion of iodobenzene atexpected square planar geometry (Raman every 3 h and sampling was done at 3, 6, 9, 12et al. 2007). and 24 h. A control reaction without catalyst had been set up and there was no indication ofCatalytic Activity iodobenzene conversion after 24 h.The Pd(II) complexes namely OPd1 The results are summarized in the Figure 5.and OPd3 were tested as catalysts in the It is observed, with increasing time, the %Suzuki-Miyaura cross-coupling reaction of 20
Amalina et al.: Synthesis and Characterization of a New Type of Ligands and their Pd(II) Complexes% Conversion Time (H)Figure 5. Percentage conversion of Iodobenzene using OPd1 and OPd3 as catalysts within 24 h.conversion of iodobenzene also increased. no. 600-RMI/FRGS 5/3 (51/2013) and 600-OPd1 showed its ability to convert iodobenzene RMI/FRGS 5/3 (52/2013).faster than OPd3 in the early hours. At the endof the reaction, phenylboronic acid was found Date of submission: September 2013to couple smoothly with iodobenzene providingexcellent yields up to 100% after 24 h for both Date of acceptance: September 2014catalysts. REFERENCES CONCLUSION Ben-saber, SM, Maihub, AA, Hudere, SS & El-Two ligands and their Pd(II) complexes ajaily, MM 2005, ‘Complexation behaviorwere successfully synthesized as confirmed of Schiff base toward transition metal ions’,by the characterization via various physico- Microchemical Journal, vol. 81, no. 2, pp.spectral techniques. The Schiff base ligands 191–194.co-ordinated through phenolic oxygen andazomethine nitrogen atoms as bidentate Bhunia, S, Sen, R & Koner, S 2010, ‘Anchoringchelates as indicated by the spectral data. of palladium(II) in chemically modifiedIt was observed that both Pd(II) complexes, mesoporous silica: an efficient heterogeneousOPd1 and OPd3 displayed properties of good catalyst for Suzuki cross-coupling reaction’,catalysts for the reaction, with up to 100% Inorganica Chimica Acta, vol. 363, no. 2, pp.conversion of iodobenzene after 24 h of 3993–3999.reaction time at 100°C in inert conditions. Cozzi, PG 2004, ‘Metal-Salen Schiff base ACKNOWLEDGEMENTS complexes in catalysis: practical aspects’, Chemical Society Reviews, vol. 33, no. 7, pp.Thanks are gratefully extended to Universiti 410–421.Teknologi MARA and the Ministry of Educationof Malaysia for scholarship and FRGS grants Dhara, K, Sarkar K, Srimani D, Saha, SK, Chattopadhyaye P & Bhaumik, A 2010, ‘A new functionalized mesoporous matrix supported Pd(II)-Schiff base complex; an efficient catalyst 21
ASEAN Journal on Science and Technology for Development, 31(1), 2014 for the Suzuki-Miyaura coupling reaction’, Mustafa, IM, Hapipah, MA, Abdulla, MA & Ward, Dalton Transactions, vol. 39, no. 28, pp. 6395– TR 2009, ‘Synthesis, structural characterization, 6402. and anti-ulcerogenic activity of schiff base ligands derived from tryptamine and 5-chloro,Dilworth, JR, Howe, SD, Hutson, AJ, Miller, JR, 5-nitro, 3,5-ditertiarybutyl salicylaldehyde Silver, J, Thompson, RM, Harman, M & and their nickel(II), copper(II), and zinc(II) Hursthouse, MB 1994, ‘Complexes of complexes’, Polyhedron, vol. 28, no. 18, pp. functionalised phosphine ligands. Part 1. 3993–3998. Complexes of FeIII, CoIII, NiII and ReV with tridentate Schiff bases having PNO, NNO Osman, AH 2006, ‘Synthesis and characterization and NNS donor sets. Crystal structures of of cobalt(II) and nickel(II) complexes of some 2-(Ph2PC6H4N=CH)C6H4OH and [Co{2- Schiff bases derived from 3-hydrazino-6- (Ph2PC6H4CH=N)C6H4O}2][PF6]’, Journal of methyl[1,2,4] triazin-5(4H)one’, Transition Metal The Chemical Society, Dalton Transactions, no. Chemistry, vol. 31, no. 1, pp. 35–41. 24, pp. 3553–3562. Ouf, AE, Ali, MS, Saad, EM & Mostafa, SI 2010,Gillis, EP & Burke, MD 2009, ‘Iterative cross- ‘pH-Metric and spectroscopic properties of coupling with MIDA boronates: towards a new 4-hydroxysalicylidene-2-aminopyrimidine general platform for small-molecule synthesis’, Schiff-base transition metal complexes’, Journal Aldrichimica Acta, vol. 42, no. 1, pp. 17–27. of Molecular Structure, vol. 973, no. 1–3, pp. 69–75.Gupta, KC & Sutar, AK 2008, ‘Catalytic activities of Schiff base transition metal complexes’, Papp, A, Tóth, D, Molnár, A 2006, ‘Suzuki– Coordination Chemistry Reviews, vol. 252, no. Miyaura coupling on heterogeneous palladium 12–14, pp. 1420–1450. catalysts’, Reaction Kinetics, Mechanisms and Catalysis, vol. 87, no. 2, pp. 335–342.Mahamo, T, Mogorosi, MM, Moss, JR, Mapolie, SF, Slootweg, JC, Lammertsma, K & Smith, GS Paul, S & Clark, JH 2003, ‘A highly active and 2012, ‘Neutral palladium(II) complexes with P,N reusable heterogeneous catalyst for the Suzuki Schiff-base ligands: Synthesis, characterization reaction: synthesis of biaryls and polyaryls’, and application as Suzuki-Miyaura coupling Green Chemistry, vol. 5, no. 5, pp. 635–638. catalysts’, Journal of Organometallic Chemistry, vol. 703, pp. 34–42. Raman, N, Sakthivel, A & Rajasekaran, K 2007, ‘Synthesis and spectral characterization ofMatos, K & Soderquist, JA 1998, ‘Alkylboranes in antifungal sensitive schiff base transition metal the Suzuki-Miyaura coupling: stereochemical complexes’, Mycobiology, vol. 35, no. 3, pp. and mechanistic studies’, Journal of Organic 150–153. Chemistry, vol. 63, no.3, pp. 461–470. Saheb, V & Sheikhshoaie, I 2011, ‘A new SchiffMcGlaken, GP & Fairlamb, JS 2009, ‘Palladium- base compound N,N’-(2,2-dimetylpropane)- catalysed cross-coupling and related processes: bis(dihydroxylacetophenone): synthesis, some interesting observations that have been experimental and theoretical studies on its exploited in synthetic chemistry’, European crystal structure, FTIR, UV-visible, 1H NMR and Journal of Organic Chemistry, vol. 2009, no. 24, 13C NMR spectra’, Spectrochimica Acta Part A, pp. 4011–4029. vol. 81, no. 1, pp. 144–150.Miyaura, N & Suzuki, A 1995, ‘Palladium-catalyzed Sallam, SA 2006, ‘Binuclear copper(II), nickel(II) cross-coupling reactions of organoboron and cobalt(II) complexes with N2O2 chromophores compounds’, Chemical Reviews, vol. 95, no. 7, of glycylglycine Schiff-bases of acetylacetone, pp. 2457–2483. benzoylacetone and thenoyltrifluoroacetone’, Transition Metal Chemistry, vol. 31, no. 1, pp.Mohamed, GG, Zayed, MA & Abdallah, SM 2010, 46–55. ‘Metal complexes of a novel Schiff base derived from sulphametrole and varelaldehyde. Synthesis, Şenol, C, Hayvali, Z, Dal, H & Hökelek, T 2011, spectral, thermal characterization and biological ‘Syntheses, characterizations and structures of activity’, Journal of Molecular Structure, vol. NO donor Schiff base ligands and nickel(II) and 979, no. 1–3, pp. 62–71. copper(II) complexes’, Journal of Molecular Structure, vol. 997, no. 1–3, pp. 53–59. 22
Amalina et al.: Synthesis and Characterization of a New Type of Ligands and their Pd(II) ComplexesSingh, BK, Rajour, HK & Prakash, A 2012, Torborg, C & Beller, M 2009, ‘Recent applications ‘Synthesis, characterization and biological of palladium-catalyzed coupling reactions in the activity of transition metal complexes with Schiff pharmaceutical, agrochemical, and fine chemical bases derived from 2-nitrobenzaldehyde with industries’, Advanced Synthesis Catalysis, vol. glycine and methionine’, Spectrochimica Acta 351, no. 18, pp. 3027–3043. Part A, vol. 94, pp. 143–151. Zolezzi, S, Decinti, A & Spodine, E 1999, ‘SynthesesTamizh, MM, & Karvembu, R 2012, ‘Synthesis and characterization of copper(II) complexes with of triethylphosphite complexes of nickel(II) Schiff-base ligands derived from ethylenediamine, and palladium(II) with tridentate Schiff base diphenylethylenediamine and nitro, bromo and ligand for catalytic application in carbon-carbon methoxy salicylaldehyde’, Polyhedron, vol. 18, coupling reactions’, Inorganic Chemistry no. 6, pp.897–904. Communications, vol. 25, pp. 30–34. 23
ASEAN J. Sci. Technol. Dev., 31(1): 24 – 30Cigarette Smoking among Male Teenagers in Malaysia ― A Narrative Review R. III P. DIOSO.This narrative review of a contemporary healthcare issue focuses on strategies and healthcareinitiatives to curtail the increasing prevalence of active cigarette smoking among male teenagersin Malaysia — a mission of the Malaysian Millennium Development Goal and the United NationsDevelopment Programmes on all health sectors. This narrative review analysed global and Malaysianviews on cigarette smoking.Key words: Healthcare; strategies; initiatives; curtail cigarette smoking; male teenagers; MalaysiaThis narrative review aims to analyse the impact et al. 2006; Lee et al. 2005; Naing et al. 2004;of active cigarette-smoking as a contemporary WHO, 2012; Ferrante et al. 2010). The secondhealthcare issue in Malaysia. Another aim of type is called the second-hand smoking orthis review is to identify the best strategy and passive smoking defined as, the exposure tohealthcare initiative to curtail the prevalence of environmental cigarette smoke (Kiechl et al.cigarette-smoking in all health sectors. 2002; Lim et al. 2010). According to World Health Organisation Search Strategy(WHO 2012), cigarette smoking is the actionor habit of inhaling and exhaling the smoke of Literatures reviewed were from years 2000–cigarettes. Smoking in general can attribute to 2014. Limitations were set on databases toa lot of physical illnesses and diseases; hence, English language. Key words used were:it distracts the mental, psychological and social Malaysian male teenage cigarette smokers;capacity of an individual to adapt (Kiechl et al. active cigarette smoking habits; prevalence2002; Lim et al. 2010; Isohanni et al. 2006; of male cigarette smoking in Malaysia andLee et al. 2005; Naing et al. 2004; WHO 2012; worldwide; and severity of the prevalenceFerrante et al. 2010). Specifically, active of active cigarette smoking among malecigarette-smoking disturbs a person’s well being teenagers, that were entered as text in search(Mohide, 1988; Kiechl et al. 2002) because it engines such as Researchgate, Google Scholarsweakens their heart, brains and lungs. and Cochrane databases with abstracts and full texts. There are two types of cigarette smoking.The active smoking or first-hand smoking is Methods of Reviewknown as the first type defined as, the act ofinhaling the smoke of cigarettes from one’s self A critiquing framework (Figure 1) was used to(Kiechl et al. 2002; Lim et al. 2010; Isohanni analyse the literatures selected for this review since it was designed with nine categoriesLincoln University College, Block A, Lot 1, Mayang Plaza, 1 Jalan SS 26/1, Taman Mayang, 47301 Petaling Jaya, MalaysiaE-mail: [email protected]
R. III P. Dioso: Cigarette Smoking among Male Teenagers in Malaysia ― A Narrative ReviewCommon features of:Quantitative QualitativeResearch design Philosophical backgroundExperimental hypothesis Research designOperational definitions ConceptsPopulation ContextSample SampleSampling SamplingValidity/reliability of data Auditability of dataData analysis Credibility/comfirmability of data analysisGeneralizability TransferabilityFigure 1. Critiquing framework (Couglan et al. 2007; Ryan et al. 2007).as guides to conveniently aid the reviewer to of America (11%), Europe (24%), Eastmake sense of evidence from clinical trials and Mediterranean (6%), Western Pacific (48%),theories (Polit & Beck 2011; Ryan et al. 2007; Africa (3%) and Southeast Asia (8%) (WHOCouglan et al. 2007). 2012). It was also found that from year 2000 to 2010, the global severity of cigarette RESULT smoking by male teenagers increased over 100 times with an average of 865 pieces ofWorldwide Prevalence of Cigarette cigarettes or 43 packs per day worldwide.SmokingA World Health Organisation (WHO, 2012) In Malaysia, a ten-year survey wasstudy has showed a total of 43 trillion conducted by a global organisation calledactive cigarette smokers all over the world Global Adult Tobacco Survey (GATS 2012)(Figure 2). They are found on the regions and found that 43.9% of cigarette smokers America Europe Western Pacific Africa Southeast Asia East MediterraneanFigure 2. Global illustration from six regions where cigarettes are smoked for their whole life from a total population of 43 trillion. 25
ASEAN Journal on Science and Technology for Development, 31(1), 2014were male teenagers. Active teenage cigarette The perception of a relief from stresssmokers in Malaysia smoke on a daily basis, as after so much of studying and thinking makessurveyed by GATS (2012), are local citizens, teenage boys influence each other (Isohannitransient visitors from foreign countries, regular et al. 2006; Child et al. 2010; Jeanfreau et al.male teenage tourists and children of foreign 2010; Lee et al. 2005).immigrants. Aside from gender, the successful lifestyle Another study was done by Lim et al. coming from a specific race, ethnicity and(2010) for 1180 teenage students in comparison culture are also influential (Isohanni et al.and in contrast with the GATS (2012) survey, 2006; Gonseth et al. 2012; Poland et al. 2006).with a response rate of 94.7% (1117). Of the Eventually these become influential to young1117 respondents, 705 (63.1%) are former boys making them actively smoke cigarettes assmokers and 397 (35.5%) are current smokers. a part of thier lifestyle.Among the current smokers, 36 (9.1%) wasdaily smokers, 48 (12.1%) smoke once every Lastly, cigarettes used for entertainmenttwo days, 131 (33.0%) smoke once or twice a influences male teenagers to actively smokeweek and the rest smoke once a week (Lim et al., cigarette smoking (Isohanni et al. 2006; Afiah2010; WHO-MOH 2012). et al. 2006). According to Poland et al. (2006), active cigarette smoking entertains the social The GATS survey in comparison with the appetite and social life. It is also entertainingstudies done by Lim et al. (2010) was found when young boys in Malaysia tend to showto be higher as prevalent in male adolescents’ off their ability to buy cigarettes to make theircigarette smoking. It was also higher compared social status higher as influenced by adults (Limwith what is reported by the MOH (2006) et al. 2010; Naing et al. 2004).spanning from the city of Kota Bharu in the stateof Kelantan to the city of Petaling Jaya in the These health determinants were evaluatedstate of Selangor (Afiah et al. 2006). using a system called health screening. Health screening is done in public and private schools The prevalence of cigarette smoking in in Malaysia by GATS (2012) and MOH (2007).Malaysia, complicated by gender, race, ethnicity High school young boys ages 13–19 years oldand culture, particularly influenced male were interviewed with survey forms to knowteenage cigarette smokers who continue the their perceptions regarding smoking cigaretteschain of influence among their peers (Wakefield (WHO-MOH 2012).et al. 2000; Naing et al. 2004; Poland et al.2006). Health screening also involved organisations to visit hospitals and to analyse DISCUSSION statistics on average teenage adolescents confinement taken yearly with collaborationsInfluence is a determinant of health that from the MOH (Gabing 2010). A scheduleincreases the prevalence of cigarette smoking of yearly statistical presentation among otheramong male teenagers (Child & Wi 2010; healthcare institutions and hospitals gatherFerrante et al. 2010; Watsen et al. 2010). together in a certain place to present findings or analyse statistical data collected from hospital Teenage boys are perceived to influence confinement, mortality and discharged patientstheir peers of the same gender (Lim et al. 2010; with presenting illnesses and diseases as causedAfiah 2006; Ferrante et al. 2010). by cigarette smoking (MOH 2007). 26
R. III P. Dioso: Cigarette Smoking among Male Teenagers in Malaysia ― A Narrative Review Another form of health screening is soon adopted by the Malaysians in 2008. Thebeing done annually on a continuous research MOH used teenagers to rally and march acrossconducted by Disease Control Division (MOH main roads and all over national highways of2007). Malaysia carrying a banner with printed words saying Tak nak (Say No) (MOH 2008). This The survey results found that active kind of campaign may stimulate the minds ofcigarette smokers among teenage boys are influenced teenagers that it is not good to smokedivided into current smokers, daily smokers, (MacFarlane et al. 2010) and that egos can beoccasional heavy smokers and former daily boosted in other ways that are non-health hazard(not more than 5 years ago) smokers (Lim related (MOH 2008).et al. 2010; GATS 2012; MOH 2007). Thisimpacts the MOH’s healthcare delivery system Another campaign implemented by thesince teenagers’ health are at risk if they are Malaysian MOH (2008/2006) was adoptedinfluenced to become active cigarette smokers from the policies of the World Bank (Lewit(Lim et al. 2010; WHO 2008; Lee et al. 2005). et al. 1981) recommending governmentsThere is a need to ensure that the Malaysian worldwide to introduce a dedicated tax ongovernment invests strategies to control or tobacco products. Teenagers, as anticipated,decrease the number of teenagers who smoke cannot afford to buy cigarettes in their youth(WHO-MOH 2012). (Wakefield et al. 2000). However, some of the school age students in Malaysia who cannotImplications to Health Promotions afford a pack of cigarettes will buy a single stick (Lim et al. 2010), that is allowed by some statesWHO-MOH (2012) implemented varieties of like Sabah and Sarawak (MOH 2006).programmes to control cigarette smoking withan aim to reduce its consumption. The control of the habit of cigarette smoking was not strong enough using taxes, that was why One of its programmes is to promote another policy to make the strategy strongerpictorial health warnings on cigarette packs with was initiated.a general message that says Smoking CausesHarm to Health (MOH 2008). These photos The Malayasian MOH (2006/2007) bannedwere further enhanced when other researchers certain areas in Malaysia from smoking andsuggested showing pictures of cancerous used signboards with written warnings fororgans i.e. throat, neck, lung, mouth and brain smokers such as smoke-free area. The privatecancers (Azam & Maizura 2004). Another and government owned institutions in Malaysiaillustration of these pictures suggested by Azam supported this strategy by imposing a fine onand Maizura (2004) used heart failures with smokers caught by security personnel smokingischemic tissues, chronic obstructive pulmonary within the ‘no smoking’ zone. Over 80% ofdiseases, veins with plaques as adopted from institutions in Malaysia supported this campaignanatomy and physiology books (Tortora & using a total cigarette smoking ban indoors withDerrickson 2010). air-conditioners such as restaurants, hospitals and educational institutions (MOH 2006/2007). Another programme implemented by This is also practiced worldwide as indoor-the Malaysian MOH (2007/2008) launched private institutions placed a smoking area that isa campaign called Say No in 2004. This located in a small location so that lesser peoplecampaign was first initiated by the Southeast will smoke (Wakefield et al. 2000).Asian Tobacco Control Alliance and was 27
ASEAN Journal on Science and Technology for Development, 31(1), 2014Analysis CONCLUSIONThe identified strategies on health promotions The prevalence of active and second-handand illness preventions against active cigarette cigarette smoking among male teenagers insmoking acquired a critical understanding Malaysia should be prevented.and demonstrated a commitment to applyprofessional values in complex healthcare It is therefore concluded that in order forsituations. Active cigarette smoking in a healthcare initiatives, such as MMDG andMalaysia is a contemporary healthcare issue UNDP, to overcome problems of cigarettethat needs to be identified. smoking, a good strategy is important especially on campaigning preventive measures against This narrative review is for future reference the threats of chain cigarette smoking. Inamong healthcare professionals to be vigilant addition, an awareness campaign shouldin preventing illnesses or promoting measures emphasise on preventing teenagers’ influentialand procedures to improve a person’s wellbeing capabilities to non-cigarette smokers.(Olla 2006; Mohide 1988). Active and second-hand cigarette smoking The target of the Malaysian Millennium can cause chronic and/or incurable physiologicDevelopment Goal (MMDG) (WHO-MOH imbalances. That is why prevention is better2012) in the health sector is to curtial the than cure.threats of cigarette smoking that impacts onteenage boys in Malaysia. Teenage active Date of submission: July 2014cigarette smokers influence other teenagers tosmoke cigarettes (Lim et al. 2010; Watsen et al. Date of acceptance: November 20142010). REFERENCES United Nations Development Programmes(UNDP) (2011) recommended to healthcare Afiah, MZ, Hejar, AR, Kulanthayan, KC, Fadhilah, Jprofessionals a multi-disciplinary approach & Law, TH 2006, ‘Prevalence of smoking andto encourarge individuals to join campaigns drinking habits among form six students inagainst cigarette smoking (WHO 2012) using Petaling district, Selangor’, Medical Journalhealthcare intitiatives. Malaysia, vol. 61, no. 1, pp. 41–47. Campaigns must endeavour to curtail Azam, A & Maizurah, O 2004, ‘Cigarette Packages:chain smoking as a health hazard (Isohanni how far the visual messages influence youth’, inet al. 2010; Ferrante et al. 2010). Chain smokers The 7th Asia Pacific Conference on Tobacco oramong male teenagers can acquire diseases Health, MOH, Malaysia.and illnesses that are morbid and very difficultto cure when they grow older (Kiechl et al. Child, E & Wi, HD 2010, ‘Effects of acute2002; Tortora & Derrickson 2010). psychosocial stress on cigarette craving and smoking’, Nicotine and Tobacco Research, vol. This is the wider health threat that impacts 12, no. 4, pp. 449–453.teenage boys who smokes cigarettes (Lim et al.2010) especially if their smokes affects their Coughlan, M, Cronin, P & Ryan, F 2007, ‘Step-by-family members or peers who are confirmed to step guide to critiquing research methodologies,be pregnant or ill — extending to the severity Part 1: quantitative Research’, British Journal ofof second-hand smoking. Nursing, vol. 16, no. 1, pp. 658–663. Ferrante, M, Fiore, M, Lean, L, Costantidines, F, Castaing, M, Fallico, R, Sciacca, S & Modonutti, GB 2010, ‘Age of smoking initiation, tobacco habits and risk perception among primary, middle and high school students in Southern Italy’, 28
R. III P. Dioso: Cigarette Smoking among Male Teenagers in Malaysia ― A Narrative Review Italian Journal of Public Health, vol. 7, no. 3, ‘Prevalence, smoking habit and factors related pp. 262–267. to smoking and nicotine addiction among lower secondary school male students in Kota TinggiGabing, F 2010, ‘The Sabah perspective: health District, Johor, Malaysia’, Malaysian Journal promotion initiatives in rural health’, The of Public Health Medicine, vol. 10, no. 1, pp. Malaysian Journal of Nursing. A Journal for 28–37. the Healthcare and Nursing Community, vol. 1, no. 3, pp. 21–24. MacFrlane, K, Paynter, J & Arroll, B 2011, ‘Tax as a motivating factor to make a quit attemptGlobal Adult Tobacco Survey 2012, GATS from smoking’, Journal of Primary Health Care, collaborative group: question-by-question vol. 3, no. 4, pp. 283–288. specifications, Version 2.0, Centers for Disease Control and Prevention, Atlanta. Ministry of Health 2008, Food Act 1983, Control of tobacco product (amendment) regulations,Gonseth, S, Sadowski, IJ, Diethelm, PA, Barras, V Malaysia, MOH. & Cermiz, J 2012, ‘The tobacco industry’s past role in weight control related to smoking’, The Ministry of Health 2007, Disease Control Division, European Journal of Public Health Advance, Clinical Practice Guidelines. Treatment of vol. 22, no. 2, pp. 234–237. tobacco smoking and dependence, MOH, KL, Malaysia.Isohanni, M, Moilanen, I & Rantakallio, P 2006, ‘Determinants of teenage smoking, with special Ministry of Health Malaysia 2006, Smoking: the reference to non-standard family background’, third national health and morbidity survey, 2006, British Journal of Addiction, vol. 86, no. 4, Institute of Public Health, Malaysia. pp. 391–398. Mohide, EA, Torrance, GW, Streiner, DL, Pringle,Jeanfreau, S, Porche, D & Lee, OD 2010, DM & Gilbert, R 1988, ‘Measuring the ‘Determinants of health: a framework for wellbeing of family caregivers using the advanced health assessment: men’s health’, The time trade-off technique’, Journal of Clinical Journal for Nurse Practitioners, vol. 6, no. 3, Epidemiology, vol. 41, no. 5, pp. 475–482. pp. 226–227. Naing, NN, Zulkifli, A, Razlan, M, Farique Rizal,Kiechl, S, Werner, P, Egger, G, Oberhollenzer, AH, Haslan, G & Mohd Hilmi, AB 2004, ‘Factor F, Mayr, G, Xu, Q, Poewe, W & Willeit, J related to smoking habit of male adolescents’, 2002, ‘Active and passive smoking, chronic Tobacco Induced Diseases, vol. 2, no, 3, pp. infections, and the risk of carotid atherosclerosis 133–140. prospective results from the Bruneck study’, Journal of the American Heart Association, Olla, P 2006, Book review: handbook of informatics vol. 33, pp. 2170–2176. for nurses and health care professionals, 3rd edn, International Journal of Healthcare InformationNaing, NN , Zulkifli, A, Razlan, M, Farique Rizal, Systems and Informatics, vol. 1, no. 3, pp. 77–79. AH, Haslan, G & Mohd Hilmi, AB 2004, ‘Factor related to smoking habit of male Poland, B, Frohlich, K, Haines, RJ, Mykhalorskiy, E, adolescents’, Tobacco Induced Diseases, vol. 2, Rock, M & Sparkus, R 2006, ‘The social context no. 3, pp. 133–140. of smoking: the next frontier in tobacco control’, Tobacco Control, vol. 15, pp. 59–63.Lee, LK, Paul, CYC, Kam, CW & Jagmohni, K 2005, ‘Smoking among secondary school Polit, DF & Beck, C T 2011, Nursing research: students in Negeri Sembilan, Malaysia’, Asia generating and assessing evidence for nursing Pacific Journal of Public Health, vol. 17, no. 2, practice, 9th edn, Lippincott Williams & Wilkins, pp. 130–136. USA.Lewit, EM, Coate, D & Grossman, M 1981, ‘The Ryan, F, Coughlan, M & Cronin, P 2007, ‘Step-by- effects of government regulation on teenage step guide to critiquing research methodologies, smoking’, Journal of Law and Economics, vol. part 2: qualitative research’, British Journal of 24, no. 3, pp. 273–298. Nursing, vol. 16, no. 2, pp. 738–744.Lim, KH, Sumarni, MG, Kee, CC, Norhamimah, A, Tortora, G & Derrickson, B 2010, Essentials of Wan Rozita, WM & Amal, NM 2010, anatomy and physiology (Malaysian student version), 8th edn, John Wiley and Sons, Asia. 29
ASEAN Journal on Science and Technology for Development, 31(1), 2014United Nations Development Programmes 2011, ‘brief advice’ letters plus nicotine replacement Malaysian development goal, UNDP, Geneva. therapy vouchers’, Journal of Primary Health Care, vol. 2, no. 1, pp. 4–10.Wakefield, M, Frank, J, Kaufman, NJ, Orleans, CT, Barker, D & Ruel, E 2000, ‘Effect of restrictions World Health Organization–Ministry of Health, on smoking at home, at school, and in public 2012, World health organization–Malaysia: places on teenage smoking: cross sectional country cooperative strategy 2009–2013, WHO, study’, British Medical Journal, vol. 321, pp. Geneva. 623–630. World Health Organization 2012, World healthWatsen, D, Bullen, C, Glover, M, McRobbie, report on the global tobacco epidemic, 2008: H, Parag, V & Walker, N 2010, ‘Impact on the MPOWER package, WHO, Geneva. quit attempt of mailed general practitioner 30
ASEAN J. Sci. Technol. Dev., 31(1): 31 – 37Forecsting of Hydrological Time Series Data with Lag-one Markov Chain Model M. A. MALEK1* AND A. M. BAKI2Planning and operation are important elements in water resource management. Rainfall forecastingis one of the conducts commonly used to extend the lead-time for catchments with short responsetime. However, it is difficult to obtain a high degree of accuracy in rainfall forecasting usingdeterministic models. Therefore, a probability-based rainfall forecasting model, based on MarkovChain provided a better alternative due to its ability to preserve the basic statistical properties ofthe original series. This method was especially useful in the absence of long-term recorded data, arampant phenomenon in Malaysia. Comparison of statistics in the generated synthetic rainfall dataagainst those of the observed data revealed that reasonable levels of acceptability were achieved.Key words: Rainfall forecasting; Lag-one Markov chain; model; stochastic; synthetic rainfall dataMalaysia’s climate is overwhelmingly can be very different in magnitude with thecharacterised by uniform temperature, high next most extreme event. It is often debatablehumidity, copious rainfall and light winds. As whether the extreme event is representativein any parts of equatorial doldrums, intermittent of the period recorded. The severity of a longrain and sunshine within a day is a norm, drought can change drastically by adding oras such, a long period of clear sky is rare. subtracting one year of its duration. To enableOne of the commonly identified problems in estimates of likelihood of severe events to bewater resource management in Malaysia is made, stochastic process is simulated whereunavailability of long-term historical records. long sequences of events are generated. If theWhere there is data availability, it was found generation is done correctly, the hypotheticalto be discontinuous. Since forecasting using sequences would have as equal likelihood ofrainfall data requires long-term continuous occurrences in the future as in the observedrecorded historical data, a stochastic type of records.model simulation that can cope with thesesituations is proposed. Any hydrological time series data are typically supported by two contributing factors MODEL CONCEPTALISATION namely random and persistence (stochastically deterministic) factor. Rainfall is regarded asIn this study, the available hydrological records the most basic weather variable, independentused were usually less than 100 years. In fact of temperature and evaporation. Therefore,most of the records are less than 25 years. generation of long-term synthetic rainfall dataEven in the case of the longest record, the can provide basic sets of weather variable formost extreme event such as drought or flood1 The Institute of Energy, Policy and Research, Universiti Tenaga Nasional, Jalan IKRAM-UNITEN, 43009, Kajang, Selangor. Malaysia2 Faculty of Civil Engineering, Universiti Technologi MARA, Shah Alam, Selangor, Malaysia* Corresponding author (e-mail: [email protected])
ASEAN Journal on Science and Technology for Development, 31(1), 2014long-term forecasting. In Lag-One Markov in Peninsular Malaysia, to the river mouthChain Model, one-year historical data can be spanning over a total length of 120 km. Theused to forecast the subsequent year’s rainfall location map of the catchment areas is as showndata. Similarly if a three-year historical data in Figure 1.are used, we can forecast the next three-yearrainfall data. Gombak river catchment area was selected because of the long period of data available. Daily rainfall data used in this model was For automatic station, 28 years of data wereavailable from three types of recordings namely recorded. For data logger stations, differentthe manual, automatic and data logger. Rainfall period of recorded data was found as thedata from chart and data logger recordings were loggers were originally installed on differentselected based on the period of data provided by dates. Detail information about the location,the recorder. Data from either the data logger period of data recorded and type of recordingsor manual method were selected to replace the is as shown in Table 1. Types of rainfall gaugenon-available data in the chart recorder method. available at the study area and its capability areIf all these three methods failed to supply the shown in Table 2.data for any particular day then the data fromthe nearby rainfall stations were used. The types of data used in this study are as follows: The time series rainfall data used in thisstudy must satisfy certain requirements. The 1. Automatic Station — 30 year periodaim of the analysis is to find scale-independent of daily rainfall data.properties. Thus, the series should span over alarge range of scale. This means that the data 2. Data Logger Station — Period of dailyhas to be continuous and of high temporal and rainfall data will depend on the dateintensity resolution. All intensity levels must be of the instrument installed.correctly represented in the data. However thisis difficult to be accomplished when measuring Analysis was performed on the totalat high intensity resolution. It has been shown monthly rainfall figures (mm): maximumthat an insufficient intensity resolution, which rainfall for every month (mm); minimumleads to erroneous representation of especially rainfall for every month (mm); mean of thelow-intensity rainfall, might attract artificial rainfall for every month (η); skew of rainfallbreaks in scaling behaviour. amount for every month (γ); standard deviation rainfall amount for every month (σ) and In this study, analysis was made on daily coefficient of variation (Cv).rainfall data from 1974 to 2003 for eight rainfallstations in the Gombak river catchment areas Benson and Matalas (1967) and Solomonin Selangor (one of the states in Malaysia). (1976), found that regionalized parametersThe Gombak river is geographically located are more suitable than single site parametersat latitude 3° 8’ 53” north of the Equator because regionalization reduced operational biasand longitude 101° 41’ 44” east of the Prime due to temporal and spatial variations inherentMeridian on the map of Kuala Lumpur. The in historic sequences. Based on these findings,river drains from the main river which is the the use of catchment area’s average rainfallKlang river. The Klang river drains an area of data instead of rainfall data from individualabout 12002 km extending from the headwaters stations was found to be more desirable inin steep mountain forests of the Main Range stochastic method of generating synthetic data. The usage of catchment area’s average 32
M.A. Malek and A.M. Baki: Forecsting of Hydrological Time Series Data with Lag-one Markov Chain ModelFigure 1. Location of rainfall stations at the Gombak river catchment area. (Source: Jabatan Pengairan dan Saliran (JPS), Malaysia, 2005).TABLE 1. Location, station number, period of data recorded and type of recording methods at rainfall stations in the Gombak river catchment area. Location Station no. Data period / recording methodP1 Genting Sempah 3317004 1974–2002 / Automatic and data loggerP2 Air Terjun Sg. Batu 3317001 1985–2003/ Automatic and data loggerP3 Kampung Sg. Sleh 3217004 1993–2003/ Automatic and data loggerP4 Ibu Bekalan KM 16 3217001 1985–2003/ Automatic and data loggerP5 Kampung Sg. Tua 3216001 1993–2003/ Automatic and data loggerP6 Gombak Simpang 3 3217005 1982–1999/ Automatic and data loggerP7 Empangan Genting Klang 3217002 1993–2003/ Automatic and data loggerP8 Ibu Bekalan KM 11 3217003 1974–2002/ Automatic and data loggerTable 2. Type of rainfall gauge and capability available at study area.Type of rainfall gauge Instrument capability 1. Automatic Monthly (Daily) / Annually 2. Data logger Monthly (Daily) / Annually 33
ASEAN Journal on Science and Technology for Development, 31(1), 2014rainfall data allowed better approximations of The outline of model operations was asrainfall stochastic properties. The catchment’s follows:average rainfall is computed using ThiessenPolygon Method (Thiessen 1911). Figure 2 1. The daily recorded data was calculated:shows a sample of Thiessen average rainfall mean and standard deviation (σi) ofdata determination. everyday (i) in a year. METHODOLOGY 2. The overall serial correlation (ri) of the recorded data was also calculated.Baki (1997) adopted the approach used byAdamowski and Smith (1972) by using runoff 3. The standardized daily rainfall (Zi) wasgeneration type model to generate daily rainfall computed.data. A first order Markov model (also knownas the Lag-one Markov Chain) was used to 4. Normally distributed random numbers (ti)generate standardized daily rainfall data. with zero mean and unit variance are generated. 5. All negative daily rainfall values were set to zero. 3317004 3317001 P1(Genting Sempah)P2(Air terjun Sg Batu) P3(Kg Sg Sleh) 3216001 P4(Ibu Bekalan KM 16)P5(Kg Sg Tua) 3217001 3217004P6(Go3m2b1a7k005Simpang 3) P7(Empangan Genting Klang) 3217003 3217002 P8(Ibu Bekalan KM 11)Figure 2. Average rainfall in the catchment areas computed using Thiessen (1911). 34
M.A. Malek and A.M. Baki: Forecsting of Hydrological Time Series Data with Lag-one Markov Chain Model DATA ANALYSIS AND RESULTS The daily estimated statistical parameters obtained are shown graphically in Figures 3The data generated was analyzed using to 5. Figure 3 shows the comparison of meanstatistical components. Table 3 shows the values for both recorded and generated data.comparison of statistical parameters obtained Figure 4 shows the comparison of standardfrom both recorded and generated data. It deviation values for both recorded and generatedwas found that the daily means were modeled data. Figure 5 shows the comparison of skewsatisfactorily. The daily standard deviations values for both recorded and generated data.achieved were almost reasonable.Table 3. Comparison of statistics on recorded DISCUSSION and generated data. In the validation of synthetic daily rainfall data Element Mean Std. deviation Skew generated from the proposed Lag-one MarkovRecorded data Chain model, three statistical parameters wereGenerated data 5.809 9.229 1.589 analyzed namely mean, standard deviation and 5.797 2.721 0.469Mean value Comparison of mean Mean recorded Mean generated 10.0 9.0 8.0 7.0 6.0 5.0 4.0 3.0 2.0 1.0 0.0 Mean Figure 3. The Mean comparison of recorded and generated data.SD value Comparison of standard deviation 10.0 8.0 6.0 SD recorded 4.0 SD generated 2.0 0.0 1 Stdev Figure 4. The standard deviation comparison of recorded and generated data. 35
ASEAN Journal on Science and Technology for Development, 31(1), 2014Skew value Comparison of skew Skew recorded Skew generated 1.8 1.6 1.4 1.2 1.0 0.8 0.6 0.4 0.2 0.0 1 Skew Figure 5. The Skew comparison of recorded and generated data.skew values. The daily mean values obtained of generated data were not significant andfrom generated data were found to be similar to could be neglected.the mean values of recorded data. It was alsofound that the model generateds reasonable CONCLUSIONdata sequences of wet and dry days. However,standard deviation values of generated data The synthetic daily rainfall data forecastedwere found to be lower than standard deviation from Lag-one Markov Chain model gave anvalues of recorded data. approximation of the statistical properties on the historical record available. The statistics The negative rainfall values presented of the generated data seemed to be sensible inin the historical rainfall records indicated generating reasonable values of daily rainfallmissing rainfall data. Setting the negative data, monthly and annual mean values, dailyrainfall values to zero affected the skew values maximum values of rainfall data, monthlyproduced by the proposed model. The skew maximum and minimum values of rainfallvalues of generated data were found to be data, as well as the length of sequences formuch lower than the skew values of recorded both dry and wet days. Thus, the proposeddata. The differences of these values indicated model was able to give a quick analysis of dailythat the generated data was almost normally rainfall data in stochastic hydrology.distributed. APPLICATION AND RECOMMENDATION In generating synthetic daily rainfall data, FOR FURTHER STUDYFortran 90 could not detect the presence ofleap years which occurred in the 26 years of Daily rainfall data analysis using the proposedrainfall records analyzed. By assuming that method could be useful for agriculturaleach year in the 26 years of rainfall record planning in Malaysia, as the method enableswas a leap year i.e. every year has 366 days, the planners to regionalize the characteristics ofFortran 90 produced additional numbers of wet and dry days. The proposed method couldgenerated data. Nevertheless, due to its small also be potentially applied as an early warningamount, the effect of these additional numbers system of probable natural disaster. The model could also be tested on other climatic data such as temperature and wind. 36
M.A. Malek and A.M. Baki: Forecsting of Hydrological Time Series Data with Lag-one Markov Chain Model ACKNOWLEDGMENT Baki, ABM 1997, ‘Stochastic rainfall generationThe authors wish to thank Jabatan Pengairan using Lag-one Markov chain Model’, Journaldan Saliran (JPS), Malaysia for access to of the Institution of Engineers Malaysia, vol. 58,data. no. 3, pp. 55–61. Date of submission: June 2014 Benson, MA & Matalas, NC 1967, ‘Synthetic Date of acceptance: October 2014 hydrology based on regional statistical parameters’, Water Resources Research, vol. 3, REFERENCES no. 4, pp. 931–935.Adamowski, K & Smith, AF 1972, ‘Stochastic Solomon, S 1976, ‘Parameter regionalization and generation of rainfall’, Journal of Hydraulics network design’, in Stochastic approaches to Division, ASCE, vol. 98(HY11), pp. 1935–1945. water resource, ed HW Shen, Colorado State University Press, Colorado, pp. 12.1–12.37. Thiessen, AH 1911, ‘Precipation averages for large areas’, in Monthly Weather Review, vol. 39, no. 7, pp. 1082–1084. 37
ASEAN J. Sci. Technol. Dev., 31(1): 38 – 48 Assessment Attributes on Effective ConstructionManagement for Property Developers in Malaysia AYOB NORIZAM1, M.A. MALEK2* AND I. MOHAMAD3Property developers are financially capable of running construction projects. Nevertheless, inMalaysia it was found that many of these construction practitioners failed to provide effectiveconstruction management which affected society. The success of a project and its Critical SuccessFactors (CSFs) are considered as tools to improve the effectiveness of project management. Eventhough many researchers have conducted studies on CSFs, the use of CSFs has remained ambiguous.The main objective of this study is to validate the proposed assessment attributes obtained fromthe property developers based on CSFs. A questionnaire survey was conducted to validate this pre-determined attributes. Comparison was made with attributes from Project Management Book ofKnowledge in order to explore the underlying suitability of the proposed attributes with the study areain terms of climate, economy, etc. Factor Analysis was adopted to investigate the group componentrelationships. This study focuses on the link between CSFs and the implementation of an effectiveconstruction management specifically for property developers in Malaysia.Key words: Critical Success Factors; property developer; assessment; construction industry;Malaysia; management; factor analysisMalaysia has shown very rapid growth treats project management as one of the severalin property and construction since the ways of handling organizational activity.1970s. The competition among property Similar arguments and standpoints are founddevelopers has created major changes in the in numerous project management research textsconstruction industries mainly in the design (Söderlund 2004).and infrastructure, in order to satisfy theneeds of the property buyers. Eventually, the Research on Critical Success Factors (CSFs)capability of property developers varies. Project in the construction industries were mainlymanagement, including the tools, techniques, based on theoretical rather than empiricaland knowledge-based practices applied to evidences (Khosrowshahi & Howes 2005).manage the creation of products and services, is But, what is the extent of expectation that couldbecoming an increasingly accepted and applied be obtained from CSFs? The outcome of thisdiscipline across industry sectors (Jugdev study is therefore to determine the measurementet al. 2007). Adoption of project management arrays as attributes in developing an effectiveis used as ‘a method’ for solving complex costruction management (CM) assessment fororganizational problems. Such a viewpoint property developer in Malaysia.1 Civil Engineering Deptartment, Universiti Tenaga Nasional, Jalan Ikram – UNITEN, 43000 Kajang, Selangor, Malaysia2 The Institute of Energy, Policy and Research (IEPRe), Universiti Tenaga Nasional, Jalan Ikram – UNITEN, 43000 Kajang, Selangor, Malaysia3 Dept of Mathematical Science, Universiti Teknologi Malaysia, 81310 Johor Bahru, Malaysia* Corresponding author (e-mail: [email protected])
Ayob Norizam et al.: Assessment Attributes on Effective Construction Management for Property DevelopersLiterature Review Chan (2004) identified five primary CSFs from 44 identified factors, which are: project-CSFs has been defined as a tool to identify related factors; project procedures; projectexecutive information needs (Rockart 1982). management actions; human-related factorsRockart et al. (1979) identified four prime and external environment (Yong & Mustaffasources of CSFs in any industry, which are: 2011; Doloi et al. 2011) established attributes(1) Structure of the industry: has its own set of that relate to schedule and performance,CSFs which are dependent on its characteristics; listing 55 attributes that were subsequently(2) Competitive strategy, industry position grouped into six CSFs and seven Criticaland geographic allocation: each organization Failure Factors. Those factors are projecthas its own strategies and strategic plan managers’ competence, supportive owners,due to the nature of the industry in which it top management monitoring, feedback, andoperates; (3) Environmental factors: the effects co-ordination. Love et al. (2002) identified 55of the environment upon the organization attributes and grouped them into five CSFs forbehaviour are essential to understand the CSFs; public-private partnership projects in the United(4) Temporal factors: CSFs changes with the Kingdom. The five categories were: effectivechange of the organization priorities, where procurement; project implementation ability;the areas of activity for success changes and government guarantees; favourable economicsome activities become more critical and others conditions, and the available financial market.become less critical (Elwakil et al. 2009). Abraham (2004) identified seven CSFs that influence the success of construction industries In Managing Information Systems, CSFs which are: competitive strategy; marketexamine their existing methodologies, and analysis; political environment; economicfrom time to time, CSFs has been widely used environment; technical application; employee/by other industries, including the construction organizational enhancement and processindustry. In the construction industry, CSFs benchmarking. Saqib (2008) listed the top fiveare integrated with eight elements that are CSFs affecting the construction industries inused as benchmarking parameters which are: Pakistan, developed from 77 identified factorsstructure of industry; competitive strategy; which are: contractor-related factors; projectmarket conditions; political environment; management factors; procurement-relatedorganizational structure; technical applications; factors and design team-related factors. Marcemployee enhancements and process Hockins (Stolton & Leverington 2006) provedbenchmarking (Rockart 1982; Sanvido et al. that CSFs are the best methodology to develop1992; Abraham 2003). Success is defined an executive monitoring system to containby Ashley et al. (1987) as ‘results much corporate-wide indicators of success (Elwakilbetter than expected or normally observed in et al. 2009). In this study, the function of CSFsterms of cost, schedule, quality, safety and is reversed by using attributes obtained fromparticipant satisfaction’. The investigation of the questionnaire survey conducted.success factors in construction industries haveattracted the interest of many researchers and RESEARCH METHODOLOGYmany studies have been conducted with theaim of providing valuable insights into how In order to achieve the objective of thisto consistently achieve superior results for the study, a questionnaire survey was distributedprojects. Although construction projects are among the practitioners in the constructionby their nature repetitive activities, each one industry which included government sectors,has its own characteristics and circumstances consultants, property developers, contractors(Salleh 2009). and others (suppliers, manufacturers, planners 39
ASEAN Journal on Science and Technology for Development, 31(1), 2014and others.). The questionnaire contained In order to determine the validity of37 nominated success factors for property the questionnaire developed in this study,developers. It was developed from an extensive Cronbach’s alpha was tested to provide anliterature review and was consolidated by a accurate estimate of internal consistencyseries of pilot studies conducted in several and indicates how well the items in the setstates of Malaysia. were correlated to one another (Brown & Adams 2000). The internal consistency ranges Five hundred sets of questionnaires were between zero and one. A commonly-accepteddistributed within Malaysia. The distribution rule of thumb is that scores of above 0.70 arewas categorized into few regions which considered acceptable (Nunnally 2010). In thisconsisted of the central region (Selangor study, Cronbach’s alpha was computed at 0.791and Kuala Lumpur), northern region ((Pulau which indicated that the items were in the formPinang, Kedah, Perak and Perlis), eastern of a scale with reasonable internal consistencyregion (Kelantan, Terengganu and Pahang), reliability.southern region (Negeri Sembilan, Melaka andJohor) and East Malaysia (Sabah and Sarawak). DATA ANALYSIS AND RESULTSData were collected and analyzed using FactorAnalysis in statistics via SPSS (V.20). The Response RateFactor Analysis technique used was PrincipalComponent Analysis (PCA) where effective A total of 344 questionnaires were satisfactorilyvariables are used to identify the principal completed, resulting to a total response ratefactors. This techniques enables a more in-depth of 68.8%. This is acceptable as accordingunderstanding of factor grouping techniques to Takim et al. (2004) and Peansupap et al.to underpin the success measures (Robinson (2005); they stated normal response rate in theet al. 2005). PCA can also be used for hypothesis construction industries for postal questionnairestesting or in searching for constructs within a is approximately between 20% to 30%. Thegroup of variables (Sommerville et al. 2004). General Respondent Demographic showed thatIt is a series of methods for finding clusters of the majority of the respondents (48.3%) wererelated variables and hence an ideal technique from property developers as shown in Table 1.for reducing a large number of items into amore easily understood framework (Norusis The questionnaires were distributed to2008). Since the numbers of variables for all practitioners in the construction industriesCSFs for pre-determined attributes were about in Malaysia. Based on Table 1, it was found37 numbers, Factor Analysis was used in this that the highest respondents were propertystudy, to converge these numbers to make it developers (48.4%), followed by contractorsmore reliable. (20.6%), consultants (14.2%), the government sector (12.5%) and others (4.4%). Table 1. Respondent to questionnaire based on General Respondent Demographics.Valid Type of organization Frequency Percent Valid prcent Cumulative percent Government 43 12.5 12.5 12.5 Consultants 49 14.2 14.2 26.7 Property developer 166 48.3 48.3 75.0 Contractor 71 20.6 20.6 95.6 Others 15 4.4 4.4 100.0 Total 344 100.0 100.0 40
Ayob Norizam et al.: Assessment Attributes on Effective Construction Management for Property DevelopersRanking of Critical Success Factors The CSFs identified in this study were largely in line with the findings of otherThe first analysis was performed to rank researchers in the field of CSFs. Nevertheless,the nominated factors based on the mean unlike other studies on CSFs, this study ledvalues of the responses. In this study, it was to the refinement of the assessment attributesassumed that if two or more factors happen that would ensure affective constructionto have the same mean values, then the one management in Malaysia.with the lowest standard deviation would beassigned as the highest important rank among Factor Analysisthe nominated factors. In addition, factorswith means exceeding or equal to the value In this study, Factor Analysis is used to exploreof four are recognized as CSFs based on the and detect the underlying relationships amongconsensus of the respondents. In this study, the identified CSFs. This statistical technique15 factors were identified as CSFs having identifies a relatively small number of factorssignificant influence on the success of this that can be used to represent relationships amongstudy. Table 2 shows the ranking of these factors sets of many interrelated variables. Various testsaccording to the value of their statistical means.Table 2. Ranking of success factors based on ‘Mean’ value.Success factors Mean Standard Ranking deviation 1 2Construction Manager’s organizing skills 4.60 0.644 3 4.51 0.752All aspects of safety, with particular reference to implementation 4.43 0.551 4 of safety programme 4.41 0.646 5Monitoring results of specific construction as per required with 6 relevant quality standards. Identifying ways to eliminate 4.40 0.654 7 causes of unsatisfactory 4.35 0.769 4.30 0.768 8Evaluating overall construction performance on a regular basis 9 to provide confidence that the constructions as per required 4.30 0.675 10 quality standard 4.28 0.511 11 4.27 0.607 12Identifying which quality standards are relevant to the 4.25 0.667 construction and execution as per requirement 4.22 0.618Identifying ways to eliminate causes of unsatisfactoryConstruction Manager’s experience and capabilities with particular reference to technical, administrative, human relations and communication skillsConstruction Manager’s leadership skillsConstruction planning processes in design, implementation and monitoring are as per approved documentation.Developing individual and group skills to enhance construction performance.Subdividing major construction deliverables into smaller, more manageable componentsCarrying out the Construction plan by performing the activities included there in 41
ASEAN Journal on Science and Technology for Development, 31(1), 2014Table 2 (Cont.). Ranking of success factors based on ‘Mean’ value.Success factors Mean Standard Ranking deviation 13Analyzing activity sequences 4.18 0.656 14 4.17 0.611 15Estimation of period for each construction stage 4.17 0.556 16 4.15 0.763 17Company have their own monetary capabilities before start work 4.14 0.687 18Coordinating changes across the entire construction 4.13 0.759 19Establish a written scope statement as basis for future 4.13 0.836 construction decisions 20 4.12 1.029All aspects of safety, with particular reference to safety 21 monitoring programme 4.12 0.655 22Construction Manager’s commitment to meeting cost, schedule, 4.11 0.944 safety and quality commitment 23 4.08 0.767 24Defining enhancement steps for opportunities and responses 4.07 0.869 to threats 25 4.07 0.729All aspects of safety, with particular reference to safety 26 programme regulations and requirement 4.07 0.642 27Evaluating risks to assess the range of possible construction 4.05 0.918 outcomes 28 4.04 0.729Analyzing activity durations 29 3.97 0.799 30Construction Manager’s co-ordinating ability and rapport with 3.93 0.777 31 owner/owners representatives 3.92 0.632 32 3.90 1.091Construction Manager’s co-ordinating ability and rapport with 33 contractors/subcontractors 3.89 1.010 34Committed to disburse effective construction process to the 3.88 0.986 organization throughout the project 35 3.75 1.058 36Evaluating risks interactions to assess the range of possible 3.73 0.998 37 construction outcomes 3.60 0.973Developing an approximation (estimate) for the costs of resourcesAnalyzing activity requirementsControlling changes to the construction budgetAllocation of overall cost estimation to individual work itemsResponding to changes in risk over the course of the constructionDeveloping an approximation (estimate) for the costs of resourcesDetermining which risks are likely to affect the construction and documenting the characteristics of eachDetermining resources (people, equipment, materials)Monitoring changes to the construction scheduleDetermining quantities 42
Ayob Norizam et al.: Assessment Attributes on Effective Construction Management for Property Developersare required for the appropriateness of this The advantage of this method over othermethod for factor extraction. factor analytical approaches is that the mathematical representation of the derived In this study, 37 numbers of CSFs were linear combinations avoids the need for theobtained as shown in Table 3 subjected to Factor use of questionable causal models (Johnson &Analysis using PCA and varimax rotation. PCA Carter 1993; Shen & Liu 2003).is a common method in Factor Analysis. Itinvolves the generation of linear combinations Interpretations of the Components Groupof variables in Factor Analysis so that thevariance present in the collected data are In this study, eight numbers of groupconsidered. This analysis summarizes the components were extracted using varimaxvariability in the observed data by means of rotation Factor Analysis. In accordance toa series of linear combination of ‘factors’. Burgees (2006), based on Factor AnalysisEach factor can be viewed as a ‘supervariable’ output for factor loading the results on allcomprising a specific combination of the attributes could be defined as very highactual variables examined in the survey. (0.6), high (0.3), and ignored (less than 0.3) (Kozak-Holland & Procter 2013). Table 3. Factor analysis at each group component Group component 12345678Evaluating risks interactions to assess .957 the range of possible construction outcomesDefining enhancement steps for .903 opportunities and responses to threatsDetermining resources (people, .866 equipment, materials)Determining which risks are likely .822to affect the construction anddocumenting the characteristics of eachEvaluating risks to assess the range of .789 possible construction outcomesMonitoring changes to the construction .760 scheduleDeveloping an approximation (estimate) .739 for the costs of resourcesDetermining quantities .637Developing an approximation (estimate) – .409 for the costs of resourcesConstruction Manager’s organizing skills .021Subdividing major construction – .008 deliverables into smaller, more manageable components 43
ASEAN Journal on Science and Technology for Development, 31(1), 2014Table 3 (Cont.). Factor analysis at each group component Group component 12345678Construction planning processes in design, .677 implementation and monitoring are as per approved documentation .619 .582Establish a written scope statement as .494 basis for future construction decisions .107Analysing activity sequences – .095Construction Manager’s leadership skills .636Construction Manager’s experience and .553 capabilities with particular reference to technical, administrative, human .280 relations and communication skills .037All aspects of safety, with particular .685 reference to safety monitoring .484 programme .139Evaluating overall construction .715 performance on a regular basis – .666 to provide confidence that the .245 constructions as per required quality standard – .156Identifying which quality standards are relevant to the construction and execution as per requirementAnalysing activity requirementsCo-ordinating changes across the entire constructionCompany have their own monetary capabilities before start workDeveloping individual and group skills to enhance construction performanceConstruction Manager’s co-ordinating ability and rapport with contractors/ subcontractorsAnalysing activity durationsControlling changes to the construction budgetAll aspects of safety, with particular reference to implementation of safety programmeIdentifying ways to eliminate causes of unsatisfactory 44
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