Dalam kertas ini dibentangkan hasil kajian sifat fizikal dan terma komposit elektrolit berasaskan samarium terdop seria (Ce0.8Sm0.2O1.9, SDC) dan karbonat (67%mol Li2CO3/ 33%mol Na2CO3). Komposit SDC-(Li/Na)2CO3 adalah pengalir berion yang berpotensi digunakan sebagai bahan elektrolit sel fuel oksida pepejal bersuhu rendah (LT-SOFC). Pencirian komposit elektrolit ini meliputi morfologi, luas permukaan bahan, analisis terma dan keliangan pelet elektrolit. Komposit elektrolit SDC-(Li/Na)2CO3 disediakan dalam dua langkah: (1) penyediaan serbuk samarium terdop seria melalui kaedah sol-gel dan (2) pencampuran samarium terdop seria dan karbonat dalam pelbagai komposisi yang berbeza melalui kaedah tindak balas keadaan pepejal. Pelet elektrolit dihasilkan dengan tekanan mampatan 25, 50, 150 and 200 MPa pada suhu pensinteran 500, 600, 700 dan 800oC. Keputusan XRD menunjukkan bahawa penambahan karbonat tidak mengubah struktur fasa SDC. Keputusan FESEM menunjukkan bahawa sebatian karbonat adalah amorfus dan tersebar dengan baik dalam matriks SDC. Semakin tinggi kandungan karbonat dalam komposit, luas permukaan serbuk komposit didapati semakin kecil. Keputusan analisis terma menunjukkan bahawa takat lebur fasa karbonat berkurang dengan berkurangnya kandungan karbonat. Keliangan optimum yang sesuai bagi elektrolit LT-SOFC iaitu 3.38% dan 4.85% telah dicapai masing-masing untuk sampel dengan kandungan karbonat 20% (SDC8020) dan 30% (SDC7030) dengan suhu pensinteran 600oC dan tekanan mampatan 200 MPa.
A comparative study on the fatty acids contents of three Malaysian marine fishes Tenualosa toli (Terubok), Rastrelliger kanagurta (Kembong), Stolephorus baganensis (Bilis) and three freshwater fishes Channa striatus (Haruan), Pangasius hypothalamus (Patin), Clarias macrocephalus (Keli) were carried out. Marine fishes showed more unsaturated fatty acids with 3, 4, 5 and 6 double bonds than in freshwater fishes. Two n-3 polyunsaturated fatty acids (PUFAs); eicosapentaenoic acid (EPA) and docasahaexaenoic acid (DHA) were found more in marine fishes PUFAs than in freshwater fishes. Based on the fatty acids content of DHA, EPA and arachidonic acid (AA), Stolephorus baganensis provides the best source of it (4.68%,10.5%, 4.68%) followed by Rastrelliger kanagurta (10.62%, 4.85%, 3.17%) and Tenualosa toli (9.93%, 2.50%, 0.16%). However, freshwater fishes showed small range of DHA (0.63% - 1.41%), EPA (0.11% - 0.25%) and AA (1.41% - 4.46%). Saturated fatty acids palmitic was the major fatty acid found in all fishes studied.
This study was carried out to determine the optimal parameters for the production of biomass of Trichoderma virens UKMP-1M, a fungus isolated from oil-polluted wastewater. The isolate showed maximum growth at day six after incubation in Mineral Salt Medium (MSM) in the presence of 3% (v/v) heavy Khefji Sour crude oil. Although it grew at pH between 5.0 and 7.0, it grew best at pH 5.5. T. virens UKMP-1M grew at temperatures between 25°C and 35°C, with its highest growth at 30°C. Aeration by agitation at 200 rpm was shown to yield the greatest biomass. Peptone at concentration of 1.5% (w/v) was determined to be a better nitrogen source than urea, potassium nitrate (KNO3), yeast extract, ammonium sulphate ((NH4)2SO4) and ammonium chloride (NH4Cl). Addition of 1% (v/v) crude oil to the MSM medium led to higher biomass production than the addition of 3%, 5%, 7% and 10% (v/v) crude oil. The result also revealed that 40% of total petroleum hydrocarbon (TPH), 100% of pristane and 74% of phytane compounds were degraded after 9 days of incubation at optimal physical and nutrient parameters.
In this study, juvenile male Sprague-Dawley rats (PND 22) were fed with soya extract, bisphenol A, and 17β-estradiol, respectively by oral gavage to determine the potential effect on the morphology of their reproductive organs and their hormonal levels. After three weeks of treatment (PND 43), all animals were sacrificed and the blood and testes were collected. All the three treatment groups showed histological differences in testes morphology compared to the control. Animals treated with soya extract and bisphenol A showed a decrease in circulating estradiol levels while animals treated with 17β-estradiol showed elevated circulating levels of estradiol. Only the animals treated with soya extract showed elevated levels of circulating testosterone. The results of the present study showed that, soya extract, bisphenol A, and 17β-estradiol can alter the histological structure of the testes and influence circulating steroidal hormone levels.
Kajian anatomi stip telah dijalankan ke atas tujuh spesies Davallia, iaitu D. denticulata, D. divaricata, D. trichomanioides var. trichomanioides, D. trichomanioides var. lorrainii, D. corniculata, D. repens dan D. solida var. solida di Malaysia. Kajian ini melibatkan keratan rentas bahagian stip menggunakan mikrotom gelongsor. Hasil kajian menunjukkan ciri anatomi stip seperti bentuk luaran stip, corak kehadiran sel sklerenkima di bawah epidermis, jenis dan bentuk stel, bilangan berkas vaskular, bilangan lapisan sel parenkima dan juga kehadiran cuping pada keratan rentas stip boleh digunakan untuk pengecaman dan pembezaan spesies. Ciri sepunya bagi genus Davallia ialah kehadiran sel sklerenkima mengelilingi stel dan di bawah lapisan sel epidermis, serta kehadiran sel parenkima berdinding tebal. Banyak ciri diagnostik ditemui dalam kajian ini dan antaranya ialah kehadiran satu cuping pada keratan stip tengah ditemui hanya pada D. trichomanioides var. lorrainii, corak 4 kehadiran sel sklerenkima di bawah epidermis ditemui hanya pada D. repens, corak 3 hanya ditemui pada D. solida var. solida, corak 5 dan 7 hanya ditemui pada D. corniculata, stel jenis dorsiventral protostel bagi D. divaricata dan bagi D. trichomanioides var. trichomanioides pula, kehadiran stel bentuk arka pada stip atas, stip tengah dan juga bawah merupakan ciri diagnostik yang baik untuk pengecaman spesies ini. Hasil kajian ini menunjukkan bahawa ciri anatomi stip mempunyai nilai taksonomi dalam genus Davallia dan boleh digunakan sebagai data sokongan untuk tujuan pengecaman dan pembezaan spesies.
The investigation of the aerial parts of Haplophyllum laeviusculum (Rutaceae), a perennial herb native to Iran, afforded three alkaloids, skimmianine (1), lunamarine (2), ribalinidine (3) and and two common sterols, γ-sitosterol and campesterol. The structures of compounds were identified by using spectroscopic methods by using UV, IR, NMR, MS spectra and also by comparison with previous works. There has been no detail phytochemical investigation report on the plant carried previously. This is the first report on the identification of skimmianine (1), lunamarine (2) from genus Haplophyllum.
The extraction of pectin from dragon fruit (Hylocereus polyrhizus) peels under three different extraction conditions was identified as an alternative source of commercial pectin. In this work, dried alcohol-insoluble residues (AIR) of dragon fruit peels were treated separately with 0.25% ammonium oxalate/oxalic acid at a pH of 4.6 at 85oC; 0.03 M HCl at a pH of 1.5 at 85oC; and de-ionized water at 75oC. The pectin obtained from these methods was compared in terms of yield, physicochemical properties and chemical structure. Fourier Transform Infrared Spectroscopy (FTIR) was used in the identification of dragon fruit pectins. The results showed that the pectin yield (14.96-20.14% based on dry weight), moisture content (11.13-11.33%), ash content (6.88-11.55%), equivalent weight (475.64-713.99), methoxyl content (2.98-4.34%), anhydrouronic acid (45.25-52.45%) and the degree of esterification (31.05-46.96%) varied significantly (p < 0.05) with the various extraction conditions used. Pectin extracted with ammonium oxalate gave the highest yield of pectin, with high purity and low ash content. Based on the value of methoxyl content and the degree of esterification, dragon fruit pectin can be categorized as low-methoxyl pectin.
Classified as a small island, Kapas Island experiences major problems especially in supplying freshwater where groundwater abstraction is the only way to meet the demand of drinking water and domestic use. Groundwater samples were collected from seven constructed boreholes to examine the hydrochemistry properties of major ions and in-situ parameters as these could provide a basis for future reference. The chemical composition showed strong and significant correlation for each studied parameter; an indication of the effect of environmental variables to the groundwater composition. The composition changed from Ca-rich to Na-rich are explained mostly by mixing and cation exchange processes. This study provided an input for water management at Kapas Island where groundwater is a crucial resource to maintain the hydrogeological balance of the island.
A study was conducted at Kenong Forest Park, Kuala Lipis, Pahang, to determine species composition and floristic variation of tree communities in two distinct habitats. Two plots of one hectare each were established adjacent to a limestone cave (BK) and in a lowland area (TR) of the forest park. A total of 2091 tree individuals with diameter at breast height (dbh) of 5.0 cm and above were enumerated in both plots where 1091 trees and 1000 trees occurred in the plots BK and TR, respectively. Floristic composition of tree communities at BK plot comprised of 45 families, 110 genera and 199 species, whilst the TR plot contained 232 tree species and 133 genera from 50 families. Altogether, combination of both plots produced floristic composition of 322 species, 161 genera and 54 families. Euphorbiaceae was the most speciose family for both plots, represented by 30 and 27 species in BK and TR plots, respectively. The most dominant species in the BK plot was Streblus ilicifolius (Moraceae) with Importance Value Index (IVi) of 19.18%, whilst in the TR plot, Intsia palembanica (Leguminosae) was the most dominant species with IVi of 14.58%. Total tree basal area for BK and TR plots was 26.91 m2/ha and 29.23 m2/ha, respectively, with Leguminosae dominated basal area in both plots. The Shannon-Weiner diversity Index (H’) of tree communities in both plots show high diversity values where the BK plot indicates H’ value of 4.42 (H’max= 5.26) while the TR plot shows H’ value of 4.79 (Hmax= 5.44), of which the values were different significantly (P<0.05). Community similarity between the two plots was moderate with Sorenson Similarity Index for species composition showed a value of 0.48 (48%). The ordination diagram constructed using Detrended Correspondence Analysis (DCA) demonstrated floristic variation between the two study plots. The DCA obviously separated plots between sites and this indicated a gradient of species change from the BK to the TR sites.
The objective of this study was to investigate the applicability of Bolton’s ratios in orthodontic population of Malaysian main ethnics; Malay, Chinese and Indians. Ninety convenient samples consisting of 30 pre-orthodontic study casts from each ethnic that fits the inclusion criteria were selected. The greatest mesiodistal widths of each tooth from six to six for overall ratio and three to three for anterior ratio were measured using a digital callipers linked to Hamilton Arch Tooth System software to the nearest 0.01mm. Means of the ratios were calculated using Bolton analysis. One sample t-test statistic analysis was carried out to compare the means with Bolton values of anterior ratio and overall ratio and one-way ANOVA was used to analyze comparison between ethnic groups of the anterior ratio and the overall ratio with the level of statistical significance set at p < 0.05. However, there were no significant differences when comparing Bolton values with Chinese and Indian anterior and overall ratios. The Bolton standards could be applied to Malaysian Chinese, Indians and Malay’s female. Subsequently, a specific standard should be used for the Malays orthodontic population.
Two explicit hybrid methods with algebraic order seven for the numerical integration of second-order ordinary differential equations of the form y̋ = f (x, y) are developed. The algebraic order of these methods is the highest in comparison with other explicit hybrid methods of the same class. Numerical comparisons carried out show the advantage of the new methods.
Sistem pengering suria untuk pengeringan hasil pertanian dan laut telah direka bentuk, dibina dan diuji dalam suasana cuaca di Malaysia. Sistem pengeringan suria yang dibina, diuji untuk mengeringkan rumpai laut Gracilaria changii. Rumpai laut yang dikeringkan mempunyai kandungan air sekitar 95% asas berat basah untuk menghasilkan produk kering yang mempunyai kandungan air 10%. Proses pengeringannya mengambil masa selama kira-kira 7 jam, pada purata keamatan sinaran suria 593 W/m2 dan kadar aliran udara pengering 0.0613 kg/s. Pemadanan tiga model pengeringan telah dilakukan dengan data uji kaji pengeringan rumpai laut menggunakan sistem pengering suria pada suhu udara purata dalam kebuk 50oC dan purata kelembapan relatif udara 20%. Kejituan padanan model ditentukan berdasarkan nilai R2 yang paling tinggi, juga nilai MBE dan RMSE yang paling rendah. Kajian ini mendapati model pengeringan rumpai laut yang sesuai adalah model pengeringan Page dibandingkan dengan model pengeringan yang lain (model pengeringan Newton dan model Henderson dan Pabis).
The modified spectral index r(α); the Westcott gLu(Tn) factor and absolute neutron temperature Tn were determined for the handling of non-1/ν (n, γ) reaction based on the Westcott formalism using k0-neutron activation analysis (k0-NAA) method at the Malaysian Nuclear Agency (MNA) research reactor. The r(α) was determined by the bare bi-isotopic monitor method using measurement of radionuclides of 97Zr and 95Zr. The 176Lu as non-1/ν and 197Au as 1/ν monitors were utilized for determination of gLu(Tn). The r(α) and gLu(Tn) values ranged from 0.0715 to 0.1417 with a RSD of 15.24% and from 1.7832 to 2.0149 with a RSD of 3.58%, respectively. The accuracy of the method was evaluated based on the calculated absolute neutron temperature (Tn) value. The calculated average value of Tn was 40.56±9.32°C while the value reported by MNA was 40°C, which represents an acceptable level of consistency.
Liquefactions of kenaf core wood were carried out at different phenol-kenaf (P/k) ratios. Characterizations of kenaf core wood liquefied residue were carried out to measure the degree of liquefaction. This provides a new approach to understand some fundamental aspects of the liquefaction reaction. Functional groups on the raw kenaf core wood and liquefied residue were examined using Fourier transform infrared spectroscopy (FTIR). The crystallinity index of the kenaf wood liquefied residue, which represents crystallinity changes of the cellulose component after the liquefaction process, was studied using X-ray diffraction (XRD). The surface morphology of the wood residue was observed using scanning electron microscopy (SEM). The thermal behavior of the residues was analyzed using thermogravimetric analysis (TGA). Abroad peak around 3450-3400 cm-1 representing OH stretching in lignin start to disappear as P/K ratio increases. The results showed that the higher the P/K ratio the greater the liquefaction of the lignin component in the kenaf core wood. The crystallinity index (CrI) on the kenaf liquefied residues increased with the increase in P/K ratio. SEM images showed that the small fragments attached on the liquefied kenaf residue surface were gradually removed as the P/K ratio was increased from 1.5/1.0 to 2.5/1.0, which is mainly attributed to the greater chemical penetration toward reactive site of the kenaf fibres. Residue content decreased as the P/K ratio increased from 1.5/1.0 to 2.5/1.0. TGA results showed the increase of heat resistance in the residue as the P/K ratio was increased.
Titanium dioxide nanoparticles were synthesized by using sol gel method and their physico-chemical properties were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and UV-Vis spectrophotometer. The photocatalytic property of TiO2 nanoparticles was investigated by inactivation of Escherichia coli under irradiation of fluorescent lamp. The results showed that the size of TiO2 was in the range of 3 to 7 nm with high crystallinity of anatase phase. The sharp peaks in FTIR spectrum determined the purity of TiO2 nanoparticles and absorbance peak of UV-Vis spectrum showed the energy band gap of 3.2 eV. Optimum inactivation of E. coli was obtained at 1.0 g/L TiO2 nanoparticles, with 80% of E. coli population was inactivated. The light scattering effect and insufficient concentration are the factors that cause the less effective inactivation reaction for 2.5 g/L and 0.1 g/L TiO2 concentration.
Spectrophotometric methods for the trace amount determination of Hg(II) via extraction and polyvinylalcohol (PVAl) water stabilization was explored. The methods are based on the formation of ion-association complex of Hg(II) with Rhodamine B, [(HgI4)2-][(Rhodamine B)+]2 in highly acidic solution. Extraction using benzene showed the Beer’s law was obeyed for mercury(II) in the range of 5 to 27 μg Hg(II) / 20 mL of sample and molar absorptivity, ε = 17.68 × 104 L mole-1cm-1. For polyvinylalcohol (PVAl) stabilization method, Beer’s law showed the validity range of 10 to 120 μg Hg(II) / 10 mL of sample and molar absorptivity, ε = 16.84 × 103 L mole-1cm-1. The benzene-extraction method has been applied in assessing the performance of copper sulfide ion-exchanger in removing Hg(II). The result was comparable to the result obtained using cold vapor atomic absorption spectrometry (CVAAS).
A method of PCR-restriction fragment length polymorphism (RFLP) has been utilized to differentiate the mitochondrial genes of pork and wild boar meat (Sus scrofa). The amplification PCR products of 359 bp and 531 bp were successfully amplified from the cyt b gene of these two meats. The amplification product of pork and wild boar using mt-12S rRNA gene successfully produced a single band with molecular size of 456 bp. Three restriction endonucleases (AluI, HindIII and BsaJI) were used to restrict the amplification products of the mitochondrial genes. The restriction enzymes of AluI and BsaJI were identified as potential restriction endonucleases to differentiate those meats. HindIII enzyme was unable to restrict the PCR product of both meats. The genetic differences within the cyt b gene among the two meats were successfully confirmed by PCR-RFLP analysis.
MeSH terms: Red Meat; Animals; Chromosome Mapping; DNA Restriction Enzymes; Meat; Polymorphism, Restriction Fragment Length; Swine; Polymerase Chain Reaction; Genes, rRNA; Sus scrofa; Cytochromes b; Genes, Mitochondrial
Air environmental health indicators were defined operationally as a combination of “air quality” and “air-related health” indicators. Clean air is a basic precondition of human health. Air pollutants had been identified with potential negative impact on health especially on respiratory and cardiovascular diseases. Thus, studies are necessary to identify and understand the state of environmental health. This study was aimed to examine and analyse the air environmental health condition in city of Kuala Lumpur by using a set of indicators. House to house questionnaire survey was carried out to collect air-related health data, and air quality sampling was carried out to identify ambient air quality level of the city. In general, city of Kuala Lumpur was found to have a “moderate level” of air quality. Air-related illnesses indicated by acute respiratory infection and asthma were found to be higher in more developed or higher density zones, as compared to other zones. Besides, air-related illnesses were significantly correlated to respondents’ exposure to air pollution. The findings imply that human health can be improved by managing the urban development and its environmental quality properly.
This paper studies the harvesting strategies for tilapia fish farming. Two logistic growth models have been used namely constant harvesting and periodic harvesting. Even though tilapia fish farming has been commercialized, the use of mathematical models in determining harvesting strategies has not been widely applied in Malaysia. Logistic growth model is appropriate for population growth of animal when overcrowding and competition resources are taken into consideration. The objectives of this study were to estimate the highest continuing yield from fish harvesting strategies implemented. Secondly, the study predicted the optimum quantity for harvesting that can ensure the tilapia fish supply is continuous. Finally, to compare the results obtained between the two strategies. The best harvesting strategy for the selected fish farm is periodic harvesting. These findings can assist fish farmers to increase the supply to meet the demand for tilapia fish.
The effectiveness of the hot oil treatment process on 15 year old cultivated Acacia hybrid was studied. Accelerated laboratory durability studies were conducted on the hot oil treated Acacia hybrid inoculated with fungi Coriolus versicolors, Gloeophyllum trabeum and Pycnoporus sanguineus. The logs of Acacia hybrid were harvested, segregated into bottom, middle and top portions, and later were oil-heat treated in an organic palm oil at temperatures of 180, 200 and 220°C for the duration of 30, 60 and 90 min. The wood samples that were dried and ground into sawdust was air-dried again before undergoing accelerated laboratory durability tests. Untreated samples were used as control. The durability of the wood increases with an increase in temperature and duration of the treatment. The hot oil treated samples could reduce the attack of G. trabeum from 20.89%, 20.94% and 21.29% in the control samples to 0.88-4.07%, 1.22-4.84% and 1.28-4.22% at bottom, middle and top portions, respectively. The attack of C. versicolors were reduced from 26.59%, 30.28% and 34.79% in the control samples to 2.89-9.41%, 3.88-16.84 and 4.27-17.34% at bottom, middle and top portions. However, the attacked of P. sanguineus were least effective with 31.42%, 36.33% and 36.55% in control samples to 3.26-12.55%, 4.67-15.36% and 4.69-19.22% at bottom, middle and top portions. Massive colonization of mycelia occurs in vessels of the untreated Acacia hybrid wood in comparison to the hot oil treated wood when observed through scanning electron microscope.