Andrographolide was separated from Andrographis paniculata Nees by using column chromatography and recrystallized from methanol. 1H and 13C NMR, IR, UV spectroscopic and GCMS data were in agreement with the previous report. The crystallined product has a monoclinic system with space group P21, a=6.541(1), b=8.003(1), c=17.962(2) Å and β=97.39(1)19o. The bicyclohexane fragments have a chair conformation with the methyl and the methylene hydroxyl groups occupying the axial position, while the OH and the C2-lactone are in the equatorial positions. The bond lengths and the angles are in the normal ranges. There are two intramolecular interactions of the type O-H … O and C-H …. O in the molecule. The molecule is stabilized by two interhydrogen bonds O-H … O and C-H … O to form polymeric chains parallel to b-axis.
Andrografolid telah dipisahkan daripada herba Andrographis paniculata Nees dengan kaedah kromatografi turus dan dihablur semula daripada metanol. Analisis spektroskopi RMN 1H dan 13C, 1M, UL, KGSJ bersetuju dengan laporan terdahulu. Hablur produk mempunyai sistem monoklinik dengan kumpulan ruang P21, a=6.541(1), b=8.003(1), c=I7.962(2)Å dan β =97.39(1)°. Fragmen bisikloheksana berkonformasi kerusi dengan kumpulan metil dan CH2OH mengisi kedudukan paksi. Kumpulan OH serta C2-lakton berada di kedudukan khatulistiwa. Panjang dan sudut ikatan adalah normal. Terdapat dua ikatan intrahidrogen O-H .... O dan satu C-H .. O. Molekul distabilkan oleh dua ikatan interhidrogen O-H ……O dan C-H .… O membentuk rangkaian polimer tak terhingga selari dengan paksi- b.
Optical sensing material for detection of pH has been prepared by immobilising phenol red in nafion membrane. Glass slides with dimension 3 in × 1 in were used as a support. The nafion membrane doped with phenol red was characterized by using uv-Visible Spectrophotometer to study the responses at different pH, repeatability and photo stability. The sensing materials were able to be used for the development of an optical pH sensor since the reagent could be successfully immobilised and produced good responses at different pH.
Bahan sensor untuk pengesanan pH telah disediakan dengan memegunkan reagen fenol merah dalam membran nafion. Slaid kaca yang berukuran 3 in × 1 in telah digunakan sebagai penyokong. Setelah dipegunkan. membran terdop dengan reagen fenol merah dicirikan menggunakan Spektrofotometer uL-Nampak untuk mengkaji kebolehulangan. kestabilan foto dan kesan terhadap pH berbeza. Hasil kajian menunjukkan bahawa bahan ini boleh digunakan sebagai bahan sensor dalam pembinaan sensor optik pH kerana reagen berjaya dipegunkan dan memberikan rangsangan yang baik pada pH yang berbeza.
A new species from the Goniothalamus genus, G. tomentosus, was investigated. Two alkaloids, aristololactam BII 1 and ouregidione 2 together with a stigmasterol isolated from the stem bark and roots were identified using spectroscopic techniques.
Spesies baru daripada genus Gonitothalamus, G. tomemtosus telah dikaji. Dua sebatian alkaloid aristololaktam BII 1 dan ouregidion 2 serta stigmasterol yang dipencilkan daripada kulit batang dan akar telah ditentukan dengan menggunakan teknik spektroskopi.
A study on the design of solid-state ion sensor was carried out. The electrode used was based on Ag/AgCl and two types of Ag/AgCl electrode designs used were rod-shape and screen printed (SPE) Ag/AgCl electrodes. The assessment of the electrode response was based on anion response, especially the response of chloride ions. Apart from that, the solid-state electrodes were also assessed for their response to several cations after a photocured polymer membrane with an immobilised lipophilic salt sensitive to cations was deposited on the electrodes. The results show that the use of a poly(hydroxyl ethyl methacrylate) hydrated with a salt solution is important to replace the inner reference solution of a conventional non solid-state ionÂ-selective electrode if normal response of an electrode is to be obtained. The sensor response which remains near to Nernstian after undergoing membrane deposition processes by photocuring technique indicate that these solid-state ion sensors can be used for the construction of biosensors that are based on potentiometric transduction.
Kajian rekabentuk sensor ion jenis keadaan-pepejal telah dilakukan. Elektrod yang digunakan adalah berdasarkan kepada Ag/AgCl. Rekabentuk dua jenis elektrod keadaan pepejal telah dipilih, iaitu berdasarkan elektrod Ag/AgCl jenis rod dan jenis elektrod Ag/AgCl bercetak skrin (screen printed electrode, SPE). Penilaian termasuk kajian responsnya terhadap anion, khasnya ion klorida. Di samping itu, respons elektrod keadaan-pepejal ini terhadap beberapa kation juga dilakukan setelah elektrod rod dan SPE disalutkan dengan beberapa jenis fotopolimer serta pemegunan garam lipofilik yang peka kepada kation. Hasil kajian menunjukkan penggunaan poli(hidroksi etil metakrilat) terhidrat dengan larutan garam untuk menggantikan larutan rujukan dalaman bagi elektrod pemilih ion konvensional yang bukan berbentuk keadaan-pepejal adalah penting demi menghasilkan sensor berbentuk keadaan pepejal yang bersifat normal. Ciri sensor ion yang masih bersifat hampir Nernstian walaupun telah mengalami beberapa proses fabrikasi sistem fotopolimer menunjukkan bahawa sensor keadaan-pepejal ini boleh juga digunakan dalam rekabentuk biosensor potentiometrik selain daripada sensor ion.
Two adducts of bis(N-benzyl-N-isopropyldithiocarbamato) zinc(II) with 2,2'Â-bipyridine and 1,10-phenanthroline have been successfully synthesized and characterized by elemental analysis and spectroscopic studies. The IR specÂtra of these adducts showed the thioureide band, v(C---- N) which occurred at 1440 and 1438 cm-1 respectively, lower than the parent compound at 1471 cm-1. The 13C NMR spectroscopic data for these compounds showed that the carbon signal from CS2 moiety shifted slightly downfield to 206.6 and 208.5 ppm compared to the parent compound at 205.1 ppm. The single crystal structure of bis (N-benzyl-N-isopropyldithiocarbamato )zinc(II)(bipy) has been determined. The structure of this compound showed monomeric nature with hexacoordination of the metal in a highly distorted octahedral geometry.
Dua sebatian aduk zink(II) benzilisopropilditiokarbamat dengan ligan 2,2-bipiridil dan 1,10-fenantrolin telah berjaya disediakan dan dianalisis menggunakan analisis unsur dan kaedah spektroskopi. Spektrum IR untuk kedua-dua sebatian aduk ini telah menunjukkan kehadiran jalur tioureida, V(C----- N) pada 1440 dan 1438 cm-1 masing-masing yang mana jalur serapan ini didapati teranjak pada nilai yang lebih rendah berbanding sebatian asalnya iaitu pada 1471 cm-1. Data RMN 13C pula menunjukkan kehadiran signal karbon CS2 yang teranjak sedikit ke medan yang lebih rendah iaitu pada 206.6 dan 208.5 ppm masing-masing jika dibandingkan dengan sebatian asalnya pada 205.1 ppm. Struktur hablur tunggal bagi sebatian bis( N-benzilÂ-N-isopropilditiokarbamat)zink(11)(bipy) telah ditentukan. Struktur sebatian ini didapati bersifat monomerik dan berkoordinat enam dengan atom logam pusatnya mempunyai geometri oktahedron yang sangat terherot.
New organotin(IV) sec-butylpropyldithiocarbamate complexes have been sucÂcessfully synthesized by the reaction between N-sec-butyl-N-propylamine, carbon disulfide and organotin(IV) chloride (dimethyltin(IV), dibutyltin(IV) and triphenyltin(lV) chloride) using in-situ method. All the complexes have been characterized using elemental analysis, gravimetric analysis, infrared and NMR (1H and I3C) spectroscopy. Elemental and gravimetric analyses showed that the complexes agree with the suggested formulae, R2Sn[S2CN( sÂC4H9)(C3H7)]2 dan R‘3Sn[S2CN(s-C4H9)(C3H7)] (R = CH3 or R = C4H9; R' = C6H5 The presence of the v(C = N) and v(C = S) bands in the infrared spectra confirmed the presence of dithiocarbamate ligand in that complex. The 13C NMR spectra for all the complexes showed a resonance in the region 196.22 - 200.62 ppm, which is attributed to the carbon atom of NCS2 group. The dimethyltin(lV) sec-butylpropyldithiocarbamate, Me2Sn(SBPDtc)2 was recrystallized from CHCl3 and the structure had been determined using X-ray crystallography analysis. The structure of Me2Sn[s-C4H9)(C3H7)]2 is found to be in the monoclinic system with space group P21/n, a = 14.358(2), b = 10.6956(18), c = 17.323(3) Ã…; α = 90°, β = 99.765(4)°, γ = 90°. The complex is six-coordinated with the tin atom bonded by two dimethyl groups in cis positions and two chelating sec-butylpropyldithiocarbamates in bidentate mode.
Kompleks baru organostanum(IV) sek-butilpropilditiokarbamat telah berjaya disediakan melalui tindak balas di antara N-sek-butil-N-propilamina, karbon disulfida dan sebatian dimetilstanum(lv), dibutilstanum(IV) dan trifenilstanum(IV) klorida menggunakan kaedah in-situ. Kesemua kompleks telah dicirikan menggunakan analisis unsur, analisis gravimetri, spektroskopi inframerah dan spektroskopi resonans magnet nukleus 1H dan 13C. Analisis unsur (CHNS) dan gravimetri menunjukkan sebatian yang disintesis bersetuju dengan formula yang dicadangkan, iaitu R2Sn[S2CN(s-C4H9)(C3H7)]2 dan R'3Sn[S2CN(s-C4H9)(C3H7] (R = CH3 atau C4H9; R' = C6H5). Kehadiran jalur serapan v(C ---- N) dan v(C ---- S) pada spektrum inframerah menunjukkan kehadiran ligan ditiokarbamat dalam sebatian yang disediakan. Spektrum RMN I3C bagi ketiga-tiga kompleks menunjukkan resonan N13CS2 terletak pada julat 196.22- 200.61 ppm. Kompleks dimetilstanum(1V) sekÂbufilpropilditiokarbamat telah berjaya dihablurkan menggunakan pelarut kloroform. Kajian kristalograji sinar-X menunjukkan hablur Me2Sn[s-ÂC4H9)(C5H7)]2 bersistem monoklinik dengan kumpulan ruang P21/n, a = 14.358(2), b = 10.6956(18), c = 17.323(3) Ã…; α = 90°, β= 99.765(4)°, γ = 90°. Kompleks membentuk geometri enam koordinat dengan atom pusat stanum yang berikat dengan dua kumpulan metil pada kedudukan sis dan mengkelat secara bidentat dengan ligan sek-butil propilditiokarbamat.
A faster method for sample preparation and qualitative analysis of phytohormones, i.e. abscisic acid (ABA), indole-3-acetic acid (IAA) and 1Â-aminocyclopropane-l-carboxylic acid (ACC) is reported. Solid phase extracÂtion of Umbellifereae sp. plant extract was performed using C18 catridge ana the effluent collected was reacted to form the pentafluorobenzyl derivatives of ABA, IAA and ACC mixture. The derivatives mixture was separated and negative ion chemical ionization was carried out by using methane in a gas chromatograph-mass spectrometric instrument (GC-MS). Mass spectra of the three phytohormones are quite simple and therefore suitable for selective ion monitoring (S/M) at high sensitivity, together with their respective internal standards labeled with deuterium. However, only IAA can be determined quantitatively by GC-MS technique through the peak area ratio of SIM chromatograms for m/z 179 with m/z 174. This method allows the correction for the loss of IAA endogen during extraction when compared to the internal standard without the need for precise sampling, except during addition of the internal standard. The detection limit of IAA by this method is 5 femtomole/g wet weight of the plant.
Satu kaedah penyediaan sampel dan analisis kualitatif yang pantas bagi fitohormon iaitu asid absisik (ABA), asid indol-3-asetik (IAA) dan asid 1Â-aminosiklopropana-l-karboksilik (ACC) dilaporkan. Ekstrak daripada tumbuhan Umbellifereae sp. dilakukan pengekstrakan fasa pepejal dengan menggunakan katrij C18 dan efluen yang dipungut ditindakbalaskan bagi membentuk terbitan pentafluorobenzil bagi campuran ABA, IAA dan ACC. Campuran terbitan tersebut dipisahkan dan dilakukan pengionan kimia ion negatif dengan menggunakan metana di dalam instrumen kromatografi gas-spektrometri jisim (GC-MS). Spektrum jisim tiga hormon tersebut agak mudah dan oleh itu adalah sesuai bagi pemonitoran ion terpilih (S/M) pada kepekaan tinggi bersama dengan piawai dalaman masing-masing yang berlabel deuterium. Walau bagaimanapun, penentuan kuantitatif hanya dapat dilakukan untuk IAA menggunakan kaedah GC-MS melalui penisbahan luas puncak kromatogram S/M bagi m/z 179 dengan m/z 174. Ini membolehkan pembetulan kehilangan IAA endogen semasa pengekstrakan berbanding piawai dalaman tanpa perlu pensampelan yang teliti, kecuali semasa penambahan piawai dalaman. Had pengesanan bagi IAA melalui kaedah ini ialah 5 femtomol/g berat basah tumbuhan.
Blends of fibre-reinforced rubber based on natural rubber-thermoplastic (NR/LLDPE) reinforced by aramid fibre have been done using melt blending process. Two different processing methods were used; internal mixer and extrusion compounding in twin screw extruder. Twaron loading in the system was varied from 0 to 30%. It was found that increasing the amount of aramid fibre led to an increase in the tensile strength, tensile modulus and hardness of the composites while the strain decreased rapidly. The results showed that the optimum composition of filler loading in NR/LLDPE blend is 20%. The ,echanical behaviour was caused by the strong Twaron-matrices interaction in the composites and effective stress concentrating function of Twaron. Composites prepared using the twin-screw extruder have a higher tensile strength and tensile using the twin-screw extruder have a higher tensile stength and tensile modulus but lower impact strength compared to those prepared using internal mixer. Study of the fracture surface by scanning electron microscopy showed that the composite prepared using the internal mixer produced random fiber orientation while the twin-screw extruder produced the fibers aligned to the longitudinal direction. The results indicate that the mechanical properties of the composite were significantly influenced by the processing technique.
Penyediaan komposit getah asli termoplastik daripada NR/LLDPE yang diperkuat gentian Twaron telah dijalankan melalui proses adunan leburan. Dua kaedah penyediaan yang berbeza digunakan iaitu menggunakan mesin pencampur dalaman manakala kaedah kedua menggunakan pengekstrud skru kembar. Kandungan Twaron di dalam komposit telah diubah daripada 0 hingga 30%. Keputusan menunjukkan bahawa penambahan Twaron telah meningkatkan nilai tegasan maksima, modulus Young dan kekuatan hentaman komposit tetapi menurunkan nilai terikan maksima. Kandungan Twaron yang optimum adalah 20%. Kehadiran Twaron telah membentuk satu jaringan saling tindak gentian-matriks menyebabkan kekuatan regangan komposit meningkat. Twaron juga berfungsi sebagai penyerap hentaman yang berkesan. Penyediaan komposit menggunakan pengekstrud skru berkembar telah menghasilkan nilai kekuatan regangan yang lebih tinggi berbanding penggunaan pencampur dalaman sebaliknya kekuatan hentaman yang lebih rendah. Kajian morfologi menggunakan mikroskop imbasan elektron mendapati komposit yang disediakan menggunakan pencampur dalaman menghasilkan gentian dengan orientasi rawak manakala pengekstrud skru kembar menghasilkan orientasi gentian yang selari. Keputusan ini menunjukkan bahawa sifat mekanik komposit NR/LLDPE yang diperkuat Twaron sangat dipengaruhi oleh teknik pemprosesan.
Poly(4,4'-diphenylene diphenylvinylene) was synthesised from 4,4' dibenzoylbiphenyl with TiCl4 and zinc dust as the catalyst and reducing agent respectively in THF. 4,4' -Dibenzoylbiphenyl was prepared via Friedel-Crafts reaction with benzoylchloride and biphenyl as starting materials. The cataÂlyst used was anhydrous AlCl3 Elemental analysis, GCMS chromatogram, FTIR spectrum and melting point measurement indicated that 4,4'Âdibenzoylbiphenyl was obtained with 100% purity. The polymer was successÂfully obtained with mass recovery of 72%. Glass transition, Tg and degradaÂtion, temperature, Td found were 196°C and 465°C, respectively. Number average molecular weight and weight average molecular weight found were 7,400 g/mol and 15,500 g/mol as measured by using gel permeation chromaÂtography. Conductivity of the pristine polymer was 8.3 x 10-11 Scm-I, whereas maximum conductivity found for LiCLO4 and iodine doped samples were 1.7 x 10-7 Scm-1 (2007 fold increase) and 5.5 x 10-9 Scm-1 (66 fold increase) with 18.75% and 37.50% of optimum doping contents respectively.
Poli(4,4'-difenilena difenilvinilena) telah disintesis daripada 4,4'Â-dibenzoilbifenil menggunakan TiCl4 dan serbuk zink masing-masing sebagai mangkin dan agen penurun di dalam THF. 4,4'-Dibenzoilbijenil telah disediakan melalui tindak balas Friedel-Crafts daripada benzoilklorida dan bijenil sebagai bahan mula dan AlCl3 kontang sebagai mangkin. Analisis unsur, kromatogram GCMS, spektrum FTIR dan penentuan takat lebur menunjukkan sebatian 4,4' -dibenzoilbifenil telah berjaya diperolehi dengan ketulenan 100%. Polimer telah berjaya disintesis dengan pengumpulan semula bahan sebanyak 72%. Suhu peralihan kaca, Tg dan suhu penguraian terma, Td bagi polimer masing-masing adalah 196°C dan 465°C. Kromatografi penelapan gel menunjukkan polimer yang dihasilkan mempunyai jisim molekul purata nombor dan jisim molekul purata berat masing-masing adalah 7,400 g/mol dan 15,500 g/mol. Kekonduksian polimer asal adalah 8.3 x 10-11 Scm-1, manakala kekonduksian maksimum polimer terdop LiClO4 dan iodin masing-masing adalah 1.7 x 10-7 Scm-I (peningkatan sebanyak 2007 kali ganda) dan 5.5 x 10-9 Scm-1 (peningkatan sebanyak 66 kali ganda) dengan kandungan agen pendop optimum sebanyak 18. 75% dan 37.50%.
An investigation of the effect of discharge of domestic sewage to rivers at Kajang (Jeluh and Langat River) and coastal waters at Negeri Sembilan (Port Dickson and Blue Lagoon) was carried out. The parameters studied focused on the characteristics of sewage such as organic content (biochemiÂcal oxygen demand, BOD and nutrients (dissolved phosphate, (PO4) and nitrate (NO)). The discharge of domestic sewage from oxidation ponds near Kajang has resulted in high levels of BOD and PO4 in river water, i.e. 1.9-5.1 and 0.15-2.03 mg/L respectively. The increase in BOD is correlated (r =0.77) with the decrease in the level of dissolved oxygen (DO) in the river water. In general. the effects of domestic sewage discharge on water quality is more obvious in the Jeluh and Langat rivers at Kajang when compared to the effect on marine water.
Organostannum(IV) complexes derived from dicarboxylic acids have been successfully synthesised from triphenylstannum(IV) hydroxide (Ph3SnOH). The complexes were obtained by refluxing Ph3SnOH and the respective dicarboxylic acids (malonic, succinic, glutaric and adipic acids) using a Dean and Stark apparatus in the appropriate solvent. The free ligands and complexes were characterised by C, Hand Sn elemental analysis and spectroscopic methods such as infrared and nuclear magnetic resonance (1H, 13C NMR). Structure determination of triphenylstannum(IV) succinate, 2, showed that each dicarboxylate anion was bonded monodentatically to two triphenylstannum(IV) moieties. The geometry surrounding each stannum atom is close to a tetrahedron. Spectroscopic data obtained for all complexes were found to be similar and thus it may be concluded that all complexes have the same structure as 2.
Computer simulations is now becoming a common feature in many underÂgraduate physics textbook together with online supplements to supposedly enhance learning and understanding. Many questions arise as to how these computer simulations and online supplements are developed and is it a worthy investment on the part of the physics educators. In this paper we look at the ways how "Physlets" (Physics Applets) are developed for the purpose of the undergraduate physics curriculum. JAVA is the fastest-growing proÂgramming language today. In scientific programming, the JAVA language meets the need for a simpler object-oriented language than C++ but is not yet popular, useful and widely used in very large scale or number crunching physics simulations. One of JAVA applets’s strength is that it is device independent. And for physics learning, simulation applets embedded in World Wide Web pages allow interactive learning and students-programmable demonstrations. We will examine a few physics simulations using JAVA applets that we have developed. We also discuss the various different aspects of using JAVA applets in developing physics simulation. And finally we will look into the reasons as to why it is still not ready for use in intensive physics simulation.
Food contaminations are global problems that arise from industrial polluÂtion, agricultural practices, or from food preparation and storage processes. Food contamination may lead to adverse health effects and there is considÂerable effort on the part of governments and industry to minimize the level of contamination. A joint Food Contamination Monitoring and Assessment Programme under the UN Environmental Programme (UNEP) in conjunction with FAO and WHO was established in 1976. There are increases in numbers of 40 countries participating the programme in 1992. The main objectives of the Programme is to be informed about levels and trends of contamination in food, their contribution to total human exposure and significance with regard to public health and trade. The Programme have been concerned with levels of priority chemicals in foods of major dietary importance and a significant portion of the data concerns the estimated total dietary intake of those contaminants selected for further comparison with toxicologically available standards or tolerance intake levels.
This is a study of the incidence of dental fluorosis and the urine fluoride concentration among school children. About 84 Malay students with the age range of 16 to 17 years from a National Secondary School in the district of Kuala Lipis, Pahang was selected as respondents. The selection was based on the exposure to fluoride in drinking water supply systems. Fifty two respondents were selected from the fluoridated water supply area while 32 others were selected from the non-fluoridated area (comparative group). The objectives of this study were to determine the relationship between urine fluoride concentrations with the incidence of dental fluorosis and to compare the difference in these two variables between the 2 groups of respondents. The urine fluoride concentration was determined using a fluoride-ion specific electrode. Dental fluorosis was examined through a physical examination using the Tooth Surface Index of Fluorosis (TSIF). There was no significant difference in the mean urine fluoride concentration (mg/L) (t=0.186, p=0.853), mean urine fluoride concentration (mg/g creatinine) (t=0.069, p=0.945) and dental fluorisis (TSIF mean score) (t=0.288, p=0.774) between the two groups. There was a significant direct correlation between the urine fluoride concentrations (mg/L) (r= 0.425, p<0.00l) and the urine fluoride concentraÂtions (mg/g creatinine) (r=0.252, p=0.021) with dental fluorisis (TSIF mean score). Multiple regression statistics, indicated that dental fluorosis was significantly related to urine fluoride concentrations (b=0.0.61, p=0.028) and the number of glass of their favourite drink consumed daily (b=0.071, p=0.003). In conclusion, the urine fluoride concentrations, which represent the degree of exposure to fluoride, were found to be related to dental fluorosis, which is the biological indicator for excessive exposure to fluoride. There is no difference on the degree and the effects of exposure to fluoride between the two groups of respondents although they consumed water from two different water supply systems. Thus, the exposure to fluoride is not only through the drinking water supply, but also by other sources such as the intake of carbonated drinks and fruit juice.
Due to the increase in consumer interest, mengkudu (Morinda citrifolia) extract is being produced in several forms including dry powder. One of the methods that can be used to produce dry powder is spray drying. This study was done to determine the physical properties of powdered mengkudu extract produced by spray drying from different sections of the spray-dryer. Mengkudu extract at 50% (v/v) dilution was spray-dried using two levels of feed flow rate (350 mL/hr and 475 mL/hr) and inlet air temperature (170oC and 190oC). Spray dried mengkudu extract from the cyclone and colletion sections of the spray dryer was collected and analyzed for amount produced, moisture content and colour. No significant interaction between feed flow rate and inlet air temperature used was observed for all parameters measured. Inlet temperature used did not show any significant effect on amount of production. However, increasing the inlet air temperature from 170oC to 190oC did produce lower moisture content for samples from the cyclone but no significant difference for samples from the collection bottle, while lowering the degree of redness of samples from the collection bottle, while lowering the degree of brightness for samples from both cyclone and collection sections of the spray-dryer. Feed flow rate used did not produce any significant effect on all parameters measured.
This study compares the mean blood lead concentration and its association with the mean neurobehavioral scores between 2 groups of workers. The exposed group was made up of 50 male workers from 2 battery manufacturÂing factories and the comparative group was made up of 40 male adminisÂtrative workers from a local university. The neurobehavioral test was carried out by using a modified World Health Organization Neurobehavioral Core Test Battery (NCTS). The NCTS consists of 7 tests, which are made up of the Benton Visual Retention Test, Digit Symbol, Digit Span, Pursuit Aiming Test, Reaction Time, Santa Ana Manual Dexterity Test and Trail Making Test. Blood samples were collected by venous puncture method. Blood lead concentrations were determined by the Graphite Furnace Atomic Absorption Spectrophotometer (GFAAS). The mean blood lead concentration of the exposed group (38.5 μg/dL) is higher than the comparative group (5.6 μg/dL). Results show significant difference in the mean blood lead concentration between the 2 groups (p<0.001). There are also significant differences in the mean scores of each NCTS test such as Benton Visual Retention Test (p = 0.001), Digit Span Test (p< 0.001), Digit Symbol Test(p< 0.001), Pursuit Aiming Test (p< 0.001), Reaction Time Test (p< 0.001), Santa Ana Manual Dexterity Test (p< 0.001), Trail Making Test (p<0.001) (p< 0.001) and the overall NCTS test (p<0.001) between the 2 groups. There are significant inverse correlation between blood lead concentrations with each and overall NCTS scores when the two groups are combined. There are significant inverse correlations between blood lead concentrations with educational years and income for all respondents. Statistical tests show that blood lead, age, years of formal education, total income, years of work, and ethnicity contributes to the overall NCTS scores. The GLM model shows that 56.9% of the mean NCTS scores are influenced by the variability in the contributing factors mentioned before.
Palm oil mill effluent (POME) can be utilised directly as the sole substrate in the anaerobic fermentation of acetone-butanol-ethanol (ABE) and hydrogen by Clostridium acetobutylicum NClMB13357 in a submerged batch system. Effects of sedimented POME concentration and the initial culture pH on the production of ABE/H were studied. Sedimented POME with 90% v/v (POME90) at pH 5.8 is capable of producing 4.01 g/L ABE with acetone concentration at 1.97 g/L; butanol 1.74 g/L and ethanol 0.3 g/L. The highest concentration of butanol (1.86 g/L) was produced from a culture with initial pH 6.0. The production of hydrogen gas was proportioned to the concentration of POME. The highest hydrogen gas production was at pH 5.5 (31 mL). More than 50% (v/v) of hydrogen gas was produced at different pH except pH 4.5, when only 16% (v/v) or 5 mL of hydrogen was produced.
Off grade egg with egg yolk content of 50% higher than normal egg can be successfully used in processing of hydrolysate flavourings. Protein extracÂtion using ethanol with two different ratios of egg yolk: ethanol: water ( 1: 1: 1 and 1:5:2) was carried out. The egg yolk protein was hydrolysed with 3N and 5N HCI for 10 hours at 11 ()'C. The protein hydrolysate obtained was freeze dried. Studies showed that extraction using 1:5:2 ratio gave the highest protein content. The protein hydrolysate treated with 5N HCI gave the highest degree of hydrolysis. Sample of 1:5:2 - 5N had the highest degree of hydrolysis (78.8%),followed by sample of 1:1:1-5N (69.4%) and 1:5:2 - 3N (66.9%). Sensory evaluation results showed that sample of 1:5:2 - 3N produced the strongest aroma among the four samples studied. Aroma of egg yolk protein hydrolysate was similar to Brands Chicken Essence or Brovil Beef Extract. The presence of volatile compounds with amine chemical groups, alcohol, alkane, indole and phenol were detected using headspace Gas Chromatography.
A preliminary study was conducted to determine the presence and abundance of aquatic worms in Lake Chini ecosystem, Pahang (Gumum Sea). Samplings were conducted twice in 2000. Water quality analysis was conducted to determine the water quality of the lake at the sampling locations. Results showed that nutrient levels in the water body was low and values for other physical parameters such as temperature, pH and conductivity suggested that Gumum Sea in Lake Chini is free from pollution. According to Malaysian interim river classification (Department of Environment, Malaysia), Lake Chini falls within class I to III which indicates good water quality. Annelida was the most dominant phylum found in the study area, which comprise of two major families namely Naididae and Tubificidae. This phylum contributed about 59% of the total individuals sampled and the rests were Arthropoda and Plathyhelmintes. Naididae was the most dominat family and contributed over 98% of the toal population of aquatic worms present. Dero, Aulophorus, Pristina, Branchiodrilus and Ripistes were amongst the dominant genera and showed good adaptations to the pollution free ecosystem of Lake Chini.
The main purpose of this article is to introduce the technique of panel data analysis in econometrics modeling. The elasticity of labour, capital and economic of scale for twenty two food manufacturing firms covering from 1989 to 1993 is estimated using the Cobb-Douglas model. The three main techniques of panel data analysis discussed are least square dummy variables (LSDV), analysis of covariance (ANCOVA) and generalized least square (GLS). Ordinary Least Square (OLS) method is included as the basis of comparison.
MeSH terms: Commerce; Data Collection; Elasticity; Food; Least-Squares Analysis