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61.
Yassen Mahmood T. Hussan Mohammed R. Hammas Hussain A. Al-Saedi Hussam Ali Jawad K. 《Wireless Personal Communications》2019,104(2):649-662
Wireless Personal Communications - The design of a fractal based slot antenna, to serve the dual-band communication applications, is proposed in this paper. The structure of the proposed antenna is... 相似文献
62.
Chang Abeer Memon Tayab Din Hussain Zahir M. Kalwar Imtiaz Hussain Chowdhry Bhawani Shankar 《Wireless Personal Communications》2019,106(4):1915-1929
Wireless Personal Communications - Matched filtering has found its way in many diverse applications such as communication, signal processing and more. The emphasis of this paper is on the design... 相似文献
63.
Nadeem Abbas Faisal Abdullah Ijaz Hussain Muhammad Ikram Shazia Anwer Bukhari 《International Journal of Food Properties》2017,20(11):2782-2792
The objective of the present study was to analyze and compare the phenolic compounds and their antioxidant capacities of new lines of Dacus carota. The selected cultivars showed high variation in the contents of total phenolics (30.26–65.39 mg/100 g FW) and total ascorbic acid (41.12–58.36 mg/100 g FW). Analysis on RP-HPLC revealed that hydroxycinnamic acids and its derivatives were major phenolic compounds present in D. carota extracts, whereas 5-caffeolquinic acid was a major hydroxycinnamic acid (ranged from 30.26 to 65.39 mg/100 g FW). DCP cultivar showed high total antioxidant capacity (77.69 mg/100 g), 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging capacity (52.36 mg/100 g), superoxide radical scavenging capacity (53.69 mg/100 g), and hydroxyl radical scavenging capacity (51.91 mg/100 g). A linear relationship was found between total phenolic acid contents and antioxidant capacity. Both phenolic compounds and antioxidant capacities varied significantly (ρ < 0.05) among cultivars. DCP cultivar was found to be a rich source of phenolics and ascorbic acid with high antioxidant activity. 相似文献
64.
Bowsher JG Hussain A Williams PA Shelton JC 《Proceedings of the Institution of Mechanical Engineers. Part H, Journal of engineering in medicine》2006,220(2):279-287
This study investigated changes in metal-on-metal (MOM) hip wear and wear particle characteristics arising from a more aggressive patient activity level compared with normal walking. The test hypothesis was that 'severe'-gait conditions will change wear, wear particle sizes, and morphology owing to a decline in joint lubrication. Four carbon MOM hip bearings 40 mm high were subjected to normal-walking and fast-jogging simulations in an orbital hip joint simulator with 25 per cent alpha-calf serum as a lubricant. Co-Cr-Mo wear particles were extracted using an enzymatic method, and prolate ellipsoid equations were used to estimate particle volume and surface area. Fast-jogging simulations generated a sevenfold increase in volumetric wear, a 33 per cent increase in mean wear particle size, and a threefold increase in the number of larger (needle) particles compared with walking. This resulted in a twentyfold increase in total wear particle surface area per 10(6) cycles compared with walking, thereby confirming our hypothesis. The clinical significance of this result suggests that highly active MOM patients may exhibit greater ion release than less active patients. 相似文献
65.
M Yu L Zhong AK Rishi M Khadeer G Inesi A Hussain L Zhang 《Canadian Metallurgical Quarterly》1998,273(6):3542-3546
High levels of resistance to thapsigargin (TG), a specific inhibitor of intracellular Ca2+ transport ATPases (SERCAs), can be developed in culture by stepwise exposure of mammalian cells to increasing concentrations of TG. We have identified, in two independently selected TG-resistant hamster cell lines of different lineages, mutant forms of SERCA. In the TG-resistant Chinese hamster lung fibroblast cell line DC-3F/TG, a T --> C change at nucleotide 766 introduces a Phe256 --> Leu alteration within the first cytosolic loop of the SERCA. In contrast, in the TG-resistant Syrian hamster smooth muscle cell line DDT/TG 4 microM, a T --> C change at nucleotide 767 introduces a Phe256 --> Ser mutation at that position. When these specific mutations are introduced into a wild-type full-length avian SERCA1 cDNA, transfection experiments reveal that Ca2+ transport function and ATP hydrolytic activity are not altered by such mutations. However, a 4-5-fold resistance to TG inhibition of Ca2+ transport function occurs upon the introduction of either the Phe256 --> Leu or the Phe256 --> Ser mutation into wild-type SERCA1. These specific mutations also render the hydrolytic activity of the ATPase resistant to inhibition by TG. Our results not only implicate amino acid 256 in TG-SERCA interactions, but also demonstrate that specific mutations within SERCA can mediate resistance to TG. 相似文献
66.
67.
This paper describes the investigations carried out on the kinetics of the solid-gas reaction between terephthalic acid and methyl alcohol in presence of phosphoric acid as the catalyst. As phosphoric acid itself reacts with the alcohol forming methyl phosphates, the kinetic data obtained have been analysed taking this reaction into account. The rate of formation of monomethyl phosphate has been found to be proportional to the square of the mole fraction of the acid present at any instant. The activation energy involved in this reaction is 11.3 kcal/g mole. The data obtained on terephthalic acid esterification show that; (i) the conversion sharply increases with an increase in the catalyst concentration between 30–35 per cent (w/w), (ii) the ‘shrinking particle’ model, proposed by Levenspiel for solid-gas reactions, can be conveniently adapted to represent the reaction, and (iii) the temperature dependency of the reaction follows the Arrhenius law, with activation energy being 11.5 kcal/g mole. 相似文献
68.
Amido-Amine-Based Cationic Gemini Surfactants: Thermal and Interfacial Properties and Interactions with Cationic Polyacrylamide 下载免费PDF全文
S.?M.?Shakil Hussain Muhammad?Shahzad?Kamal Abdullah?S.?SultanEmail author 《Journal of surfactants and detergents》2017,20(1):47-55
Experimental studies were conducted to investigate thermal and interfacial properties of two in‐house synthesized amido‐amine‐based cationic gemini surfactants namely: dodecanoic acid [3‐({4‐[(3‐dodecanoylamino‐propyl)‐dimethyl‐amino]‐butyl}‐dimethyl‐amino)‐propyl]‐amide dibromide ( 12‐4‐12 ) and dodecanoic acid [3‐({6‐[(3‐dodecanoylamino‐propyl)‐dimethyl‐amino]‐hexyl}‐dimethyl‐amino)‐propyl]‐amide dibromide ( 12‐6‐12 ). Thermogravimetric analysis showed the excellent thermal stability of surfactants and no structural degradation was observed at temperatures up to 250 °C. The long‐term thermal stability of the surfactants was investigated with the aid of spectroscopic techniques such as nuclear magnetic resonance (NMR (1H and 13C) and Fourier transform infrared (FTIR) spectroscopy. Both surfactants were found to be thermally stable, and no changes in structure were observed after aging for 10 days at 90 °C. The interfacial tension of the surfactants was measured at three different temperatures (30, 60, and 80 °C), and the results showed a decrease in interfacial tension with increasing temperature and increasing spacer length of the surfactants. Rheological measurements were used to assess the interactions between the cationic gemini surfactant and cationic polyacrylamide. The addition of cationic surfactant reduced the viscosity and storage modulus of the polymer at low shear rate and frequency due to surfactant–polymer interactions and charge screening. The investigated surfactant–polymer system has great potential in high‐temperature carbonate reservoirs, where conventional anionic surfactants are not recommended due to high adsorption. 相似文献
69.
Tapas Debnath Subrata Chandra Roy Claus H. Rüscher Altaf Hussain 《Journal of Materials Science》2009,44(1):179-185
Needle-shaped crystals of sizes up to 5 μm × 5 μm × 40 μm of nominal composition K
x
Nb
y
W1−y
O3 were synthesized by solid state method at 800 °C using appropriate amount of WO3, WO2, Nb2O5, and K2WO4. The samples were characterized with XRD, SEM, microprobe analysis, optical spectroscopy, and Raman spectroscopy. The XRD
patterns of the samples show single phase of tetragonal tungsten bronze (TTB) type (P4/mbm, No. 127) up to y = 0.07. Structure refinements reveal an increase in cell parameter with increasing nominal niobium content within the TTB
phase. The elemental compositions of the crystals determined by electron microprobe analysis also show an increase in Nb content
with increasing y. With increasing Nb content the reflectivity minimum in the near infrared spectral range shifts towards lower wavenumber
indicating the effect of decreasing carrier concentration. Pyrochlore type phase (KNbWO6) is obtained as a second phase when nominal composition y > 0.07. 相似文献
70.
Discretization: An Enabling Technique 总被引:26,自引:0,他引:26