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排序方式: 共有329条查询结果,搜索用时 640 毫秒
321.
Wan-Cheng Tan Radzali Othman Akihiko Matsumoto Fei-Yee Yeoh 《Journal of Thermal Analysis and Calorimetry》2012,108(3):1025-1031
Activated carbon fibre (ACF) is a nanoporous material which is useful for various important applications such as safe biogas and natural gas storage as well as heavy/precious metals removal and recovery. It is commonly produced from synthetic fibres such as rayon, polyacrylnitrile and pitch mainly derived from petroleum products, which are less environmental friendly. Besides, cost of ACF production is high due to the high burnt off percentage of such expensive raw materials. As an alternative, natural fibre of oil palm empty fruit bunch was used as a raw material for ACF preparation. Thermogravimetric analysis was carried out with two different gases, i.e. nitrogen gas and oxygen gas in order to observe pyrolysis and combustion behaviours in different gases. Carbonisation temperatures were then identified from the peaks of derivative thermogravimetry results. Different carbonisation temperatures (85?C200?°C) were chosen to carbonise the EFB fibre to observe the effect of carbonisation temperatures on the nanoporous characteristics, i.e. surface area, pore size distribution and pore volume of the ACF produced. Good nanoporous characteristics such as surface area up to 2,740?m2/g of the ACF prepared were observed, suggesting EFB fibre as an excellent candidate to replace synthetic fibre for ACF production. The discussion of relationship between thermal characteristics and nanopores in ACF derived from EFB were also included in this study. 相似文献
322.
323.
A. Kovcs M. Baranyai L. Wojnrovits A. Moussa I. Othman W. L. McLaughlin 《Radiation Physics and Chemistry》1999,55(5-6):799-803
The ions of nitro blue tetrazolium (NBT2+) in aqueous ethanol solution are readily reduced radiolytically first to monoformazan (MF+) and then to diformazan (DF) having high linear molar extinction coefficients at the absorption maxima of 522 and 570–610 nm. Spectrophotometric analysis then provides potential use in high-dose dosimetry over the dose ranges of 0.1–1 and 1–30 kGy. The solution is stable for the first 24 h after the irradiation. 相似文献
324.
The synthesis of isoindolo[2,1-b]pyrrolo[1,2-d][2,4]benzodiazocine 7 and isoindolo[1,2-d]pyrrolo[1,2-a]-[1,5]benzodiazocine 13 are described starting from 2-(2-methoxycarbonyl)benzylphthalimide 1a and ethyl α-bromohomophthalate 9 respectively. 相似文献
325.
Pascal Pigeon Mohamed Othman Pierre Netchitaïlo Bernard Decroix 《Journal of heterocyclic chemistry》1999,36(3):691-695
Isoindolo[2,1-a]quinolines 10 , 11 , 12 were synthesized from hydroxylactams 8 or 9 via an N-acyliminium ion-π-olefin nucleophile cyclization reaction. 相似文献
326.
Othman Al Musaimi Oscar M. Mercado Valenzo Daryl R. Williams 《Journal of separation science》2023,46(2):2200743
Hydrophobicity is an important physicochemical property of peptides and proteins. It is responsible for their conformational changes, stability, as well as various chemical intramolecular and intermolecular interactions. Enormous efforts have been invested to study the extent of hydrophobicity and how it could influence various biological processes, in addition to its crucial role in the separation and purification endeavor as well. Here, we have reviewed various studies that were carried out to determine the hydrophobicity starting from (i) simple amino acids solubility behavior, (ii) experimental approach that was undertaken in the reversed-phase liquid chromatography mode, and ending with (iii) some examples of more advanced computational and machine learning models. 相似文献
327.
Walaa S. Baslyman Dr. Othman Alahmed Dr. Santanu Chand Somayah Qutub Prof. Niveen M. Khashab 《Angewandte Chemie (International ed. in English)》2023,62(25):e202302840
Effective immobilization and delivery of genetic materials is at the forefront of biological and medical research directed toward tackling scientific challenges such as gene therapy and cancer treatment. Herein we present a biologically inspired hydrogen-bonded zinc adeninate framework (ZAF) consisting of zinc adeninate macrocycles that self-assemble into a 3D framework through adenine-adenine interactions. ZAF can efficiently immobilize DNAzyme with full protection against enzyme degradation and physiological conditions until it is successfully delivered into the nucleus. As compared to zeolitic imidazolate frameworks (ZIFs), ZAFs are twofold more biocompatible with a significant loading efficiency of 96 %. Overall, our design paves the way for expanding functional hydrogen-bonding-based systems as potential platforms for the loading and delivery of biologics. 相似文献
328.
329.
Azman Hassan Norhayani Othman Mat Uzir Wahit Lim Jian Wei Abdul Razak Rahmat Zainal Ariffin Mohd Ishak 《Macromolecular Symposia》2006,239(1):182-191
A series of polyamide 6/polypropylene (PA6/PP) blends and nanocomposites containing 4 wt% of organophilic modified montmorillonite (MMT) were designed and prepared by melt compounding followed by injection molding. Maleic anhydride polyethylene octene elastomer (POEgMAH) was used as impact modifier as well as compatibilizer in the blend system. Three weight ratios of PA6/PP blends were prepared i.e. 80:20, 70:30, and 60:40. The mechanical properties of PA6/PP blends and nanocomposite were studied through flexural and impact properties. Scanning electron microscopy (SEM) was used to study the microstructure. The incorporation of 10 wt% POEgMAH into PA6/PP blends significantly increased the toughness with a corresponding reduction in strength and stiffness. However, on further addition of 4 wt% organoclay, the strength and modulus increased but with a sacrifice in impact strength. It was also found that the mechanical properties are a function of blend ratio with 70:30 PA6/PP having the highest impact strength, both for blends and nanocomposites. The morphological study revealed that within the blend ratio studied, the higher the PA6 content, the finer were the POEgMAH particles. 相似文献