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New Lymantriidae record for Peninsular Malaysia: Toxoproctis hemibathes (Swinhoe)
No full textThis paper reports on a new record of the itch moth from the family Lymantriidae, Toxoproctis hemibathes (Swinhoe), for Peninsular Malaysia. The islands of Sumatera and Borneo are known to be within the geographical range of Lymantriidae, their habitat preference being the wetland and coastal forests. Our study showed that this species can also erupt in large numbers in specific locations in the southern parts of Peninsular Malaysia and thus, our finding is considered a new record for T. hemibathes (Swinhoe). This specimens were collected using portable ultra violet (UV) light trap during a population outbreak of this species in the Labis District of Johor
Simple calculation of the anisotropic factor for minimum current path in MgB2 material using the extrapolated kramer field as priori parameter
No full textThe volume flux pinning force density of MgxB2 (x = 0.8, 1.0 and 1.2) materials was calculated for grains boundary and point pinning potentials. Stoichiometric Mg0.8, MgB2, and Mg1.2B2 samples were prepared by the conventional solid state reaction method. Three pellets were annealed at temperature range of 650-800°C. Structural analysis revealed large values for FWHM at (hkl) (110)(°) which indicates distortion in the boron plane of these specimens. The a and c – axis lattice parameters showed respective contraction and elongation with the increase in processing temperature. The low crystallinity found in Mg0.8B2 and Mg1.2B2 specimens was concluded to be due to structural defects, which act as flux pinning centres. Experimental anisotropic factor and the minimum fraction for current path, obtained from the framework of current percolation theory were used to explain the strong field dependence of the critical current density, Jc in the specimens. The summit of the maximum pinning force density was shifted to lower magnetic field position with the increase of anisotropy. The scaling laws were employed in a Kramer– like field in order to identify the dominant pinning mechanism correspondence to the summit of maximum pinning. For MgB2 specimens however, a renormalization field based on the current percolation exposition is considered for the identification of their dominant pinning since it is very difficult to account for the flat behaviour of the pinning force in the weakened current region of these specimen
A long chain alcohol as support in solid phase organic synthesis
No full textThe solid phase synthesis is a method by which organic compound synthesis are performed on a support. With this method, the purification can be carried out easily by simple filtration and washing procedures. Long-chain alcohol (C-100 alcohol) can be used as a support because of its insolubility in organic solvents and its simple structure which enables it to be stable in various reaction conditions. In this study, a 4-aminopyridine derivative has been synthesized from C-100 β-keto ester and a cyano enamine using tin(VI)chloride as catalyst. C-100 β-keto ester was obtained by transesterification of long chain alcohol (the support) with ethyl acetoacetate using boric acid protocol. The cyano enamine was successfully synthesized by Thorpe-Ziegler cyclization initiated by sodium hydride. The 4-aminopyridine derivative was successfully cleaved from the support using sodium isopropoxide in refluxing isopropanol. From the 1H-NMR spectrum at ~ 120oC, it was found that the cleaved support has the same spectrum with the long-chain alcohol used in the beginning of reaction, thus, this long chain alcohol can be reused for other reaction
Kesan modifikasi sekam padi dengan getah asli cecair dan dedahan kepada alur elektron ke atas sifat mekanik komposit Nr/Hdpe /Sekam Padi
No full textSerbuk sekam padi (SP) merupakan serabut semula jadi yang boleh bertindak sebagai pengisi penguat dalam adunan getah asli termoplastik (TPNR) NR/HDPE selepas permukaan serbuk dimodifikasikan sewajarnya. Rawatan serbuk SP merangkumi pra-rawatan dengan 5% larutan natrium hidroksida (NaOH), rendaman dalam larutan getah asli cecair (LNR) dan dedahan SP tersalut LNR kepada sinaran electron (EB). Komposit TPNR/SP disediakan secara pengadunan leburan dalam pengadun dalaman pada keadaan yang telah ditentupastikan terlebih dahulu. Morfologi komposit yang dianalisis menggunakan mikroskop elektron imbasan (SEM), menunjukkan taburan zarah pengisi SP termodifikasi adalah homogen dan kewujudan interaksi matriks-zarah. Komposit terisi SP terubahsuai LNR-EB menunjukan perubahan sifat mekanik yang ketara. Nilai maksimum tegasan dan kekuatan impak adalah masing masing 6.7 MPa dan 13.2 kJ/cm2 pada dedahan 20 kGy dos EB, manakala modulus regangan adalah 79 MPa pada dos 30 kGy. Ini menunjukkan terdapat peningkatan interaksi berkesan antara-muka SP dan TPNR bagi SP terwat LNR pada dos 20-30kGy EB. Peningkatan dos EB pada SP tersalut LNR menyebabkan degradasi salutan NR dan meningkatakan interaksi antara zarah SP. Pengaglomerasian zarah SP akan berlaku dan menyebabkan serakan zarah dalam komposit menjadi tidak homoge
Microbial fuel cells using mixed cultures of wastewater for electricity generation
No full textFossil fuels (petroleum, natural gas and coal) are the main resources for generating electricity. However, they have been major contributors to environmental problems. One potential alternative to explore is the use of microbial fuel cells (MFCs), which generate electricity using microorganisms. MFCs uses catalytic reactions activated by microorganisms to convert energy preserved in the chemical bonds between organic molecules into electrical energy. MFC has the ability to generate electricity during the wastewater treatment process while simultaneously treating the pollutants. This study investigated the potential of using different types of mixed cultures (raw sewage, mixed liquor from the aeration tank & return waste activated sludge) from an activated sludge treatment plant in MFCs for electricity generation and pollutant removals (COD & total kjeldahl nitrogen, TKN). The MFC in this study was designed as a dual-chambered system, in which the chambers were separated by a NafionTM membrane using a mixed culture of wastewater as a biocatalyst. The maximum power density generated using activated sludge was 9.053 mW/cm2, with 26.8% COD removal and 40% TKN removal. It is demonstrated that MFC offers great potential to optimize power generation using mixed cultures of wastewater
Synthesis, characterization and thermal properties of two novel lanthanide 2,2’-biquinoline-4,4’-dicarboxylate complexes
No full textTwo new lanthanide coordination complexes with 2,2’-biquinoline-4,4’-dicarboxylic acid (H2bqda) and 1,10-phenanthroline (phen), [La2(Hbqda)2(bqda)2(phen)]n [1] and [Gd(bqda)1.5(phen)]n [2] were successfully synthesized and characterized. The complexes were obtained through hydrothermal method at 170oC for 3 days. The metal to acid to 1,10-phenanthroline ratio, 1:1:2 had been chosen to synthesize 1 and 2. The percentage yield for 1 and 2 was 68% and 75%, respectively calculated based on the starting lanthanide salt used. The yellow coloured complexes were found to be stable at room temperature and insoluble in organic solvents. The complexes obtained were characterized by elemental analysis (CHN), infrared spectroscopy (FTIR) and thermogravimetric (TGA) analysis. The FTIR spectra of these complexes confirm the complexation had taken place by the existence of COO- symmetric and asymmetric stretching peaks at 1385 and 1542-1532 cm-1, respectively
Kesan kepekatan glukopon 215 csup terhadap saiz dan sifat magnet nanozarah Co-Ni-Cu yang disediakan dengan kaedah elektropengendapan
No full textNanozarah Co-Ni-Cu telah disediakan dengan kaedah elektropengendapan pada keupayaan pengendapan -925 mV (SCE) menggunakan larutan sulfat (0.018M Co2++ 0.180M Ni2+ + 0.002M Cu2+) yang mengandungi surfaktan Glukopon 215 CSUP dan juga tanpa surfaktan. Kesan kepekatan surfaktan terhadap saiz dan sifat magnet nanozarah Co-Ni-Cu yang terhasil telah dikaji. Analisis morfologi permukaan endapan yang diperoleh dilakukan dengan menggunakan mikroskop elektron imbasan pancaran medan (FESEM) manakala sifat magnetnya diselidiki dengan menggunakan magnetometer getaran sampel (VSM). Nanozarah Co-Ni-Cu yang disediakan daripada larutan yang mengandungi Glukopon 215 CSUP didapati berbentuk sfera dengan saiz berskala nanometer. Saiz zarah paling kecil ialah lebih kurang 50 nm, diperoleh pada kepekatan surfaktan 5 %v, iaitu kepekatan paling tinggi yang dikaji dalam kajian ini. Kepaksaan (Hc) didapati lebih tinggi pada sampel yang disediakan daripada elektrolit yang mengandungi surfaktan berbanding tanpa surfaktan
Kesan kepekatan asid performik terhadap pengepoksidaan minyak sawit olein
No full textKajian pengoptimuman tindak balas pengepoksidaan minyak sawit olein (POo) dengan menggunakan mangkin asid performik (HCOOOH) telah dijalankan. Kesan tindak balas terhadap nisbah kepekatan HCOOH : H2O2 dan masa tindak balas telah dikaji pada suhu 45oC. Kandungan oksigen oksirana (OOC) optimum sebanyak 3.61% diperoleh dengan menggunakan nisbah mol 1 : 5 : 2 pada 150 min dan sebanyak 96.5% penukaran dapat dicapai. Hasil tindak balas adalah sebanyak 91.3%. Puncak kromatografi cecair berprestasi tinggi (HPLC) bagi minyak sawit olein terepoksida (EPOo) telah berubah sepenuhnya berbanding puncak HPLC POo. Spektrum transformasi Fourier infra-merah (FTIR) telah menunjukkan kehadiran puncak ikatan gelang oksirana pada 844 cm-1
Perubahan cuaca dan penyakit denggi: kajian kes di daerah Seremban, Negeri Sembilan, Malaysia.
No full textDenggi merupakan penyakit endemik di Malaysia. Perubahan cuaca mengakibatkan peningkatan kematian, kemorbidan serta peningkatan kes penyakit seperti denggi. Artikel ini bertujuan untuk melihat hubungan antara perubahan cuaca dengan kes denggi yang dilaporkan di Daerah Seremban.
Objektif kajian ini ialah untuk mengenalpasti hubungan antara perubahan cuaca dengan bilangan kes denggi di Daerah Seremban. Data sekunder berkaitan dengan bilangan kes penyakit bawaan-vektor dikumpul dari Pejabat Kesihatan Daerah Seremban, laman sesawang Kementerian Kesihatan
Malaysia serta temubual dengan key informant yang berpengetahuan tentangg perubahan cuaca dan kesihatan awam. Temubual telah dilaksanakan dari bulan Mac hingga Novembe 2009. Data kelembapan relatif dan data taburan hujan diperolehi dari Jabatan Meteorologi Malaysia dan Jabatan
Pengairan dan Saliran. Kaedah korelasi Pearson digunakan untuk mengkaji hubungan antara pembolehubah perubahan cuaca dengan kes denggi pada aras keyakinan p < 0.05. Hasil kajian
mendapati bahawa min suhu maksimum dan kelembapan relatif masing-masing mempunyai hubungan yang signifikan dengan bilangan kes denggi di Daerah Seremban (yakni masing-masing r = 0.625, p < 0.05 dan r = 0.969, p < 0.05). Bagi taburan hujan pula, hanya dua daripada empat stesen hujan di Daerah Seremban yang mempunyai hubungan yang signifikan dengan bilangan kes denggi:Stesen Stor JPS Sikamat (r = 0.613, p < 0.05) dan Stesen Hospital Seremban ( r = 0.64, p < 0.05)
