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91.
Amin Mirzaei Awang Jusoh Zainal Salam Ehsan Adib Hosein Farzanehfard 《Simulation Modelling Practice and Theory》2011,19(7):1651-1667
This paper presents a high efficiency non-isolated bidirectional converter which can be employed as an interface circuit between ultracapacitors or batteries and DC bus voltage. All semiconductor devices in the proposed converter are soft switched while the control circuit remains PWM. So, the energy conversion through the converter is highly efficient. The proposed converter acts as a zero-voltage transition (ZVT) buck to charge an ultracapacitor or battery and acts as a ZVT boost to discharge an ultracapacitor or battery. The performance of the proposed converter with respect to abrupt load and operating mode change is shown through computer simulation results. The results confirm the aforementioned advantages and features of the proposed converter. 相似文献
92.
Iqbal M.M. Hossain R.M. Rahman H. Das S. Hossain J. Salam A. Islam M.N. Mohsin M. 《Hemodialysis international. International Symposium on Home Hemodialysis》2005,9(1):95-96
Objective: This observational study was undertaken to evaluate the frequency of acute complications occurring during dialysis sessions and their association with other clinical and biochemical parameters. Method: Forty‐six maintenance hemodialysis patients were selected and evaluated. Mean of the weekly evaluations of different parameters over a three‐month period is presented here. Result: Age of study subjects was 39 ± 13 years and body mass index (BMI) 21 ± 4 kg/m2. Duration of hemodialysis was 41 ± 29 months. Most of the patients were hypertensive (98%), taking multiple anti‐hypertensive drugs. Mean of the blood pressures before and at the end of dialysis sessions over the three month period were: systolic blood pressure (SBP) 159 ± 18 vs. 163 ± 22 (p < 0.05) and diastolic blood pressure (DBP) 92 ± 13 vs. 87 ± 7 mmHg (p < 0.003). Frequency of acute complicating symptoms during dialysis sessions were: headache (75%), rise in blood pressure (73%), leg cramps (67%), vomiting (60%), palpitation (58%), sweating (52%), and hypotension (35%). Raised blood pressure showed a positive correlation with headache (r = 0.50, p < 0.01) and sweating (r = 0.53, p < 0.05). Vomiting and palpitation were more frequent at low post‐dialysis blood pressure (vomiting vs. post‐SBP‐r = ?0.41, p < 0.05 and palpitation vs. post‐DBP‐r = ?0.48, p < 0.05), and these patients were likely to get inadequate dialysis (hypotension vs. Kt/V‐r = ?0.63, p < 0.01). Pre and post dialysis weight variation was 53 ± 11 vs. 51 ± 11 kg (p < 0.001), average ultrafiltration during dialysis (UF)?2.39 (0.5–4) liter and single session Kt/V was 0.95 ± 0.38. The rising tendency of post‐dialysis blood pressure correlated positively with increasing UF (SBP vs. UF‐r = 0.36, p < 0.01 and DBP vs. UF‐r = 0.25, p < 0.05). Conclusion: From this study it may be concluded that acute complications during dialysis sessions have a significant correlation with deranged blood pressure regulation, and optimum control of blood pressure could provide better dialysis. 相似文献
93.
Sameh E. Ahmed Mohamed A. Mansour Emad A.‐B. Abdel‐Salam Eman F. Mohamed 《亚洲传热研究》2020,49(4):1895-1919
This paper studies the effect of fractional derivatives on the fractional convective flow of hybrid nanofluids in a wavy enclosure that has inlet and outlet parts near the left wall and is filled with a porous medium. The Caputo definition of the fractional derivatives is applied on the partial differential equations governing flow. The complex shape is mapped to a rectangular domain using appropriate transformations. The finite difference method is used to solve the resulting system. The results showed that an increase in order of the fractional derivatives causes a low activity of the fluid flow and a reduction in the rate of heat transfer. Also, an increase in the nanoparticles volume fractions reduces the activity of the fluid flow and, as a result, the rate of heat transfer is diminished. An enhancement in fluid motion and rate of the heat transfer is obtained by increasing the amplitude of the wavy wall. 相似文献
94.
Omotayo Owomofoyon Erejuwa Siti Amrah Sulaiman Mohd Suhaimi Abdul Wahab Sirajudeen Kuttulebbai Nainamohammed Salam Md Salzihan Md Salleh Sunil Gurtu 《International journal of molecular sciences》2010,11(5):2056-2066
Hyperglycemia exerts toxic effects on the pancreatic β-cells. This study investigated the hypothesis that the common antidiabetic drugs glibenclamide and metformin, in combination with tualang honey, offer additional protection for the pancreas of streptozotocin (STZ)-induced diabetic rats against oxidative stress and damage. Diabetes was induced in male Sprague Dawley rats by a single dose of STZ (60 mg/kg; ip). Diabetic rats had significantly elevated levels of lipid peroxidation (TBARS), up-regulated activities of superoxide dismutase (SOD) and glutathione peroxidase (GPx) while catalase (CAT) activity was significantly reduced. Glibenclamide and metformin produced no significant effects on TBARS and antioxidant enzymes except GPx in diabetic rats. In contrast, the combination of glibenclamide, metformin and honey significantly up-regulated CAT activity and down-regulated GPx activity while TBARS levels were significantly reduced. These findings suggest that tualang honey potentiates the effect of glibenclamide and metformin to protect diabetic rat pancreas against oxidative stress and damage. 相似文献
95.
Twenty-five patients with bilateral nasal obstruction due to hypertrophy of the inferior turbinates were entered into a prospective study to compare the efficacy and the associated complications of total inferior turbinectomy and concho-antropexy. We found no significant statistical difference in the efficacy of these procedures in relieving nasal obstruction and discharge (p > 0.5). Total inferior turbinectomy was associated with more post-operative pain (p < 0.05) and with long-term dryness and crusting (p < 0.05) which were statistically significant. This is the first trial where concho-antropexy and total inferior turbinectomy are compared. 相似文献
96.
97.
M. Ahmed I. Salam F. H. Hashmi A. Q. Khan 《Journal of Materials Engineering and Performance》1997,6(2):165-171
Chemical inhomogeneity results in the formation of banded structure in high-strength maraging steels. Segregation of titanium
and molybdenum was found to be the primary cause of banded structure formation. When the concentrations of these elements
increased beyond certain critical levels, bands comprising different grain sizes formed. The inclusions existed preferentially
along the interface of the bands. A high-temperature homogenization treatment substantially reduced or eliminated the banded
structure. The large grain size resulting from the homogenization treatment was subsequently reduced by a grain refinement
treatment. The mechanical properties of the steel substantially improved following homogenization and grain refinement. 相似文献
98.
Selective radiation coatings suitable for operation at high temperatures with focused sunlight are described. Coatings of CuO and Co3O4 on polished nickel, silver, and platinum have high absorptivity for solar radiation and low emissivity in the infrared when heated. They are stable at at high temperatures. 相似文献
99.
Mannar R. Maurya Maneesh Kumar Salam J.J. Titinchi Hanna S. Abbo Shri Chand 《Catalysis Letters》2003,86(1-3):97-105
Liquid-phase hydroxylation of phenol with H2O2 to a mixture of catechol and hydroquinone in acetonitrile has been reported using oxovanadium(IV) Schiff base complexes encapsulated in zeolite-Y as catalysts. Reaction conditions have been optimized by considering the concentration of substrate and oxidant, amount of catalyst, volume of solvent and temperature. Under the optimized reaction conditions, [VO(sal-1,3-pn)]-Y (H2sal-1,3-pn = N,N'-bis(salicylidene)propane-1,3-diamine) has shown the highest conversion of 34.3% after 6 h, [VO(salen)]-Y (H2salen = N,N'-bis(salicylidene)ethane-1,2-diamine) and [VO(saldien)]-Y (H2saldien = N,N'-bis(salicylidene)- diethylenetriamine) have comparable catalytic activity (33% conversion) while [VO(sal-1,2-pn)]-Y (H2sal-1,2-pn = N,N'-bis(salicylidene)propane-1,2-diamine) has the poorest performance (10.6% conversion). All these catalysts are more selective (90%) toward catechol formation except [VO(sal-1,3-pn)]-Y, which only gives 68% selectivity. 相似文献
100.
The authors present initial results of a pattern/character recognition and association experiment using a newly fabricated 50-neuron CMOS analog silicon chip with digital on-chip learning. Attention is given to the circuit architecture, the VLSI chips, and the interface circuitry. 相似文献