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Synthesis and antimicrobial activity of 1-(5-Mercapto-1,3,4-Oxadiazol-2-yl) -2-(Pyridine-2-ylamino)ethanone
No full text1-(5-Mercapto-1,3,4-oxadiazol-2-yl)-2-(pyridine-2-ylamino)ethanone (3), has been synthesized from 2-(pyridine-2-ylamino)acetohydrazide (2). A yellow colored compound (2) was reacted with carbon disulfide and potassium hydroxide in absolute ethanol to obtain the 1-(5-mercapto-1,3,4-oxadiazol-2-yl)-2-(pyridine-2-ylamino)ethanone. Structures of the synthesized compounds were supported by means of IR, NMR, MS spectroscopic and elemental analysis. The synthesized compounds were evaluated for their antimicrobial activity and were expressed as the corresponding minimum inhibitory concentration (MIC). A brown colored compound (3) with 90% yield has been successfully synthesized. This compound was found to have significant antimicrobial activity with MIC value ranging from 30.2 - 43.2 μg cm-3. The findings of the present study indicate that cyclization of hydrazide acid group of 2-(pyridine-2-ylamino)acetohydrazide (2) into 1,3,4-oxadiazole nucleus resulted in increased antimicrobial activity
Variation in mycorrhizal specificity for in vitro symbiotic seed germination of grammatophyllum speciosumBlume
No full textGrammatophyllum seeds are minute and lack endosperm. As with their other orchids counterpart, the seeds are dependent on mycorrhizal fungi for seed germination in nature. The ability to uptake nutrients from substrate is assisted by preferable fungal symbionts. Seeds of Grammatophyllum speciosum Blume. were used to determine the specificity of its fungus relationship using fungi isolated from roots of G. speciosum, G. stapeliiflorum and G. scriptum. A total of 31 different species of fungus was isolated and inoculated onto G. speciosum seed on Oat Meal Agar (OMA). The result obtained from the test demonstrated that seed germination rates were best when co-cultured with Fusarium sp. number 3 isolated from G. speciosum. An increment in 63.3% was measured when compared to the seed’s original size. The seed can also germinate when inoculated with fungus isolated from different species, implying that G. speciosum is a generalist in its association with fungal symbionts
Hubungan kelikatan minyak enjin terhadap usia guna serta suhu
No full textKelikatan minyak enjin bergred tunggal mengalami perubahan apabila berlakunya perubahan pada suhu dan tekanan. Namun begitu, secara realiti kelikatan minyak enjin juga mengalami perubahan terhadap usia guna. Oleh itu, kajian ini memperkenalkan satu hubungan kelikatan minyak enjin terhadap perubahan suhu serta usia guna. Hubungan ini berasaskan kepada persamaan matematik empirik yang melibatkan teori pelincir Newtonan dan bukan Newtonan. Hubungan yang baru ini dikenali sebagai model kelikatan matematik (ηmath). Dalam model ini, kelikatan minyak enjin dipengaruh oleh dua faktor iaitu faktor suhu (ks) dan faktor masa (km). Nilai kedua-dua faktor ini bergantung kepada formula bahan tambah minyak enjin tersebut. Analisis reologi meter likat telah digunakan untuk mendapatkan nilai kedua-dua faktor ini. Hasil kajian menunjukkan kelikatan minyak enjin mengalami penurunan apabila usia guna meningkat. Ini dibuktikan melalui model kelikatan matematik (ηmath) dan juga analisis reologi meter likat
Quantity and quality of groundwater in fractured metasedimentary rocks of the West Coast of Peninsular Malaysia
No full textGroundwater in fractured metasedimentary rock in Malaysia is a potential source of water for drinking and industrial
uses. Industries including agricultural processing, mineral water bottling, manufacturing and golf courses pumped
the water from the underlying fractured rocks. Fifty eight tubewells belong to private companies operating in various
places in West Coast of Peninsular Malaysia were evaluated for their yield and quality of water. Rotary percussion
methods were used for the drilling to a maximum depth of 200 m. The productivity of the wells and the characteristics
of the aquifer were evaluated by pumping test using both the constant discharge rate and steps drawdown methods. The
average yield of the wells at allowable drawdown of 40 m was found to be 416 m3 per day. Results from water quality
analysis indicated that the water was fresh with an average total dissolved solids (TDS) concentration of 101 to 150
mg/L. The hardness of the water varies from as low as 13 mg/L to a maximum of 353 mg/L. On the average, the water
was moderately hard with the average hardness value of 80 mg/L. The water facies of the groundwater was found to be
of calcium-sodium-bicarbonate water
Heavy metal concentrations in ceiling fan dusts sampled at schools around Serdang area, Selangor
No full textIn this study, ceiling fan dust samples were collected from three schools in the district of Serdang Selangor, Malaysia. The sampled dust were analysed for the concentrations of Cd, Cu, Fe, Ni, Pb and Zn. The heavy metal ranges found in all the schools were 2.96-7.74 μg/g dry weight for Cd, 75-442 μg/g dry weight for Cu, 3445-3852 μg/g dry weight for Fe, 24-66 μg/g dry weight for Ni, 140-734 μg/g dry weight for Pb and 439-880 μg/g dry weight for Zn. SMK Seri Serdang School was found to have elevated concentrations of Cd, Cu, Ni, Pb, and Zn which indicated the anthropogenic sources of the study sites. In comparison to other reported studies in the literature, the maximum levels of Cd, Cu, Ni, and Pb were comparable or higher to those cities reported. Therefore, more monitoring studies should be conducted in future since dusts could be related to human health hazards and the dusts can be used as a potential monitoring tool for heavy metal pollution in the atmosphere
Kesan lapisan berliang dan nisbah keluasan plat berlubang terhadap ciri akustik serabut sabut kelapa sebagai bahan penyerap bunyi
No full textPenyelidikan ini dilakukan untuk mengkaji ciri akustik serabut sabut kelapa yang berpotensi digunakan sebagai bahan penyerap bunyi. Untuk meningkatkan ciri akustik serabut sabut kelapa pada frekuensi rendah, lapisan berliang digunakan di bahagian depan atau belakang bertujuan untuk meningkatkan nilai galangan permukaan. Bahan selanjutnya dilapisi dengan plat berlubang dengan nisbah keluasan yang berbeza. Sampel diuji mengikut piawaian antarabangsa ASTM E 1050-98 untuk menentukan pekali penyerapan bunyi. Daripada hasil uji kaji, plat 1 mm berlubang yang diperbuat daripada kepingan aluminium yang melapisi serabut sabut kelapa, didapati bahawa nilai maksimum pekali penyerapan bunyi berada pada frekuensi antara 2750 Hz hingga 2825 Hz iaitu dengan nilai 0.97. Nilai nisbah keluasan plat berlubang memberikan pengaruh penurunan pekali penyerapan bunyi pada frekuensi tinggi. Penurunan nilai pekali penyerapan bunyi terjadi apabila plat berlubang mempunyai nilai nisbah keluasan di bawah 0.22. Akan tetapi, penggunaan plat berlubang boleh meningkatkan prestasi penyerapan bunyi serabut sabut kelapa pada frekuensi rendah. Kesepakatan yang baik diperoleh daripada keputusan uji kaji dan analisis dengan pendekatan rangkaian elektrik setara yang digunakan untuk menghitung nilai pekali penyerapan bunyi. Ini menunjukkan bahawa pendekatan rangkaian elektrik setara boleh digunakan untuk merancang dan mengoptimumkan ciri akustik serabut sabut sebagai bahan penyerap buny
Kepelbagaian kaedah penyoalan lisan dalam pengajaran guru bahasa melayu: kaedah pemerhatian
No full textThis study was conducted to gain information on the different approach used
in oral questions by Malay Language teachers. The main aspects studied are the frequency
of questions posted to students in teaching and learning process, cognitive level of the
question, the questioning skill component and the scope of the questions. The subjects were
two Malay Language teachers who have more than 10 years of teaching experience. The
observation method was used to collect the data. However, the Malay Language tearchers
tend to focus on asking simple to moderately types of questions rather than the highly
challenging ones. The findings show that the teachers frequently ask questions to the
students in the teaching and learning process. The scopes of the questions asked however
tend to be focused on individual and society rather than on global or national issues. The
student were not given the chance to think critically as the teachers prefer to use question
of the low level. The result also show a there is connection between the teacher’s teaching
experiences and the questions posted in the class. The implied that when the high level of
questioning is seldom used in teaching and learning process. The culture of teaching
critically and the student participation are limite
Synthesis and characterization of a new heterocyclic azo pigment
No full textA new heterocyclic coupling agent has been produced from the reaction of maleic anhydride and p-aminophenol, namely N-(4-hydroxylpheneyl)maleimide. The coupling agent underwent azo coupling reaction with aromatic amine, which is p-aminophenol to produce a new heterocyclic azo pigment. The pigment was then subjected to solubility, hiding power and light fastness test. Fourier Transform Infrared Spectroscopy (FTIR), Ultraviolet/Visible (UV/Vis) Spectroscopy, and Nuclear Magnetic Resonance Spectroscopy (1H-NMR, 13C-NMR) were used to obtain the characteristics and structural features of the pigment
Variasi alkohol lemak dalam sedimen permukaan di Sungai Sepang Besar, Sepang, Selangor
No full textKandungan alkohol lemak di dalam 19 sampel sedimen permukaan di Sungai Sepang Besar, Sepang, Selangor telah dianalisis menggunakan kromatografi gas-spektrometer jisim (GC-MS). Sebanyak 19 sebatian alkohol lemak dengan julat kepekatan 0.02 μg/g – 9.01 μg/g berat kering dikenalpasti yang terdiri daripada alkohol lemak C12 sehingga C30 termasuk 4 sebatian bercabang. Alkohol lemak C26 mendominasi kebanyakan stesen persampelan dengan julat 0.29 – 5.43 μg/g berat kering, iaitu 15.5% daripada jumlah alkohol lemak. Berdasarkan kepekatan individu sebatian alkohol lemak dan nisbah [Σ(C12 - C20)/Σ(C22 - C30)], Sungai Sepang Besar boleh dikatakan mengandungi alkohol lemak berantai pendek (C12 - C20) yang tinggi berasal daripada organisma marin. Walau bagaimanapun, nilai Indeks Sumber Alkohol (ASI) tidak menunjukkan Sungai Sepang Besar didominasi oleh alkohol lemak rantai pendek kerana faktor kandungan sebatian C26 yang tinggi di kebanyakan stesen persampelan. Nilai nisbah alkohol lemak (rantai ganjil)/(rantai genap) adalah tinggi bagi hampir kesemua stesen persampelan yang dipengaruhi oleh aktiviti bakteria yang tinggi. Dengan itu dapat disimpulkan bahawa sedimen permukaan Sungai Sepang Besar mengandungi campuran bahan organik yang berasal dari marin, terestrial dan bakteri
Penentuan aktiviti antimikrob herba kacangma leonurus sibiricus
No full textKajian keberkesanan sifat antimikrob ekstrak kacangma dijalankan menggunakan ujian resapan cakera dan ujian perencatan langsung. Hasil menunjukkan ekstrak etanol dengan kepekatan 50 dan 100 mg/mL merencat Staphylococcus aureus. Bagi ekstrak air, kepekatan 10, 25, 50 dan 100 mg/mL merencat Aspergillus niger, 25, 50 dan 100 mg/mL dapat merencat Saccharomyces cerevisae dan kepekatan 100 mg/mL dapat merencat Staphylococcus aureus. Perlakuan suhu yang berbeza ke atas ekstrak dalam ujian perencatan langsung tidak menunjukkan sebarang perbezaan ke atas perencatan mikroorganisma yang dikaji