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Yu Dong Tariq Mosaval Hazim J. Haroosh Rehan Umer Hitoshi Takagi Kin‐Tak Lau 《Journal of Polymer Science.Polymer Physics》2014,52(9):618-623
This pilot study elaborates the development of novel epoxy/electrospun polylactic acid (PLA) nanofiber composites at the fiber contents of 3, 5, and 10 wt % to evaluate their mechanical and thermal properties using flexural tests and differential scanning calorimetry (DSC). The flexural moduli of composites increase remarkably by 50.8 and 24.0% for 5 and 10 wt % fiber contents, respectively, relative to that of neat epoxy. Furthermore, a similar trend is also shown for corresponding flexural strengths being enhanced by 31.6 and 4.8%. Fractured surface morphology with scanning electron microscopy (SEM) confirms a full permeation of cured epoxy matrix into nanofiber structures and existence of nondestructive fibrous networks inside large void cavities. The glass transition temperature (Tg) of composites increases up to 54–60 °C due to embedded electrospun nanofibers compared to 50 °C for that of epoxy, indicating that fibrous networks may further restrict the intermolecular mobility of matrix in thermal effects. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2014 , 52, 618–623 相似文献
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Muhammad Umer Faroque Sammer Yousuf Salman Zafar M. Iqbal Choudhary Maqsood Ahmed 《Acta Crystallographica. Section C, Structural Chemistry》2016,72(5):398-404
Biotransformation is the structural modification of compounds using enzymes as the catalysts and it plays a key role in the synthesis of pharmaceutically important compounds. 10β,17β‐Dihydroxy‐17α‐methylestr‐4‐en‐3‐one dihydrate, C19H28O3·2H2O, was obtained from the fungal biotransformation of methyloestrenolone. The structure was refined using the classical independent atom model (IAM) and a transferred multipolar atom model using the ELMAM2 database. The results from the two refinements have been compared. The ELMAM2 refinement has been found to be superior in terms of the refinement statistics. It has been shown that certain electron‐density‐derived properties can be calculated on the basis of the transferred parameters for crystals which diffract to ordinary resolution. 相似文献
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Four new carbamates (RZ1–RZ4) were synthesized from different amine moieties through reported methods. The reaction was monitored using thin layer chromatography and characterization was done using m.p., fourier‐transform infrared spectroscopy (FTIR), and X‐ray diffraction (XRD) techniques. Density functional theory (DFT) studies were carried out using Gaussian 09 software to compare the theoretical and practical parameters of the synthesized compounds. Highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) were also drawn to calculate the energy difference between orbitals. In‐vitro enzyme inhibition potential against acetylcholine esterase (AChE), butyrylcholine esterase (BChE), and protease was checked through standard protocols that suggested moderate inhibition against selected enzymes. Docking studies were also carried out, which depicted that these compounds have ability to bind on the active site of AChE and BChE. 相似文献
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Alibe Ibrahim Mustapha Matori Khamirul Amin Sidek Hj Ab Aziz Yaakob Yazid Rashid Umer Alibe Ali Mustapha Zaid Mohd Hafiz Mohd Nasir Salisu Nasir Maharaz Mohammed 《Journal of Thermal Analysis and Calorimetry》2019,136(6):2249-2268
Journal of Thermal Analysis and Calorimetry - Willemite is an inorganic semiconductor material used for optoelectronic applications. The present study purposes a new polymer thermal treatment... 相似文献
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Ilyas Suhaib Umer Pendyala Rajashekhar Narahari Marneni 《Journal of Thermal Analysis and Calorimetry》2019,135(2):1197-1209
Journal of Thermal Analysis and Calorimetry - The carbon nanotubes are considered as one of the highest thermal conductive material which is having a variety of heat transfer applications. The... 相似文献
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A three-dimensional mathematical model is developed to examine the flow of nonlinear thermal radiation Oldroyd-B nanofluid past a bidirectional linearly stretched surface in a porous medium. The flow is induced by temperature dependent thermal conductivity, chemical reaction and convective heat and mass conditions. Novel characteristics of Brownian motion and thermophoresis are accompanied by magnetohydrodynamic and heat generation/absorption. Self-similar transformations are employed to convert the system of nonlinear partial differential equations to a system of ordinary differential equations with high nonlinearity and are solved by strong analytic technique named as Homotopy Analysis method (HAM). Effects of varied arising parameters on involved distributions are reflected through graphical illustrations. From this study, it is perceived that strong magnetic field hinders the fluid's motion and leads to rise in temperature that eventually lowers heat transfer rate from the surface. Further, decrease in heat transfer rate is also observed for enhanced values of thermal radiation parameter. To validate our results, a comparison with already published paper in limiting case is also given and results are found in excellent oncurrence; hence reliable results are being presented. 相似文献
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Ararat an Ulus Firdevs Umer Muhammad 《Journal of Optimization Theory and Applications》2022,194(2):681-712
Journal of Optimization Theory and Applications - We propose an algorithm to generate inner and outer polyhedral approximations to the upper image of a bounded convex vector optimization problem.... 相似文献
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Brajendra K. Sharma Umer Rashid Farooq Anwar Sevim Z. Erhan 《Journal of Thermal Analysis and Calorimetry》2009,96(3):999-1008
The increasing application of biobased lubricants could significantly reduce environmental pollution and contribute to the
replacement of petroleum base oils. Vegetable oils are recognized as rapidly biodegradable and are thus promising candidates
for use as base fluids in formulation of environment friendly lubricants. Although many vegetable oils have excellent lubricity,
they often have poor oxidation and low temperature stability. Here in, we report the lubricant potential of Moringa oil, which
has 74% oleic acid content and thus possess improved oxidation stability over many other natural oils. For comparison, Jatropha
oil, cottonseed oil, canola oil and sunflower oil were also studied. Among these oils, Moringa oil exhibits the highest thermo-oxidative
stability measured using PDSC and TG. Canola oil demonstrated superior low temperature stability as measured using cryogenic
DSC, pour point and cloud point measurements. The friction and wear properties were measured using HFRR. Overall, it was concluded
that Moringa oil has potential in formulation of industrial fluids for high temperature applications.
Names are necessary to report factually on available data; however, the USDA neither guarantees nor warrants the standard
of the product, and the use of the name by USDA implies no approval of the product to the exclusion of others that may also
be suitable. 相似文献