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排序方式: 共有157条查询结果,搜索用时 31 毫秒
21.
Irshad Ahmad Shazia Shukrullah Muhammad Yasin Naz Muhammad Athar Rasheed Mukhtar Ahmad Ejaz Ahmed Muhammad Shoaib Akhtar N.R. Khalid Abid Hussain Sadia Khalid 《International Journal of Hydrogen Energy》2021,46(53):26711-26724
CNTs were decorated onto Sr doped ZnO nanoparticles to construct an efficient photocatalyst via a facile sol-gel method. The as-fabricated Sr doped ZnO/CNTs with recyclability exhibits Sr and CNTs content dependent hydrogen evolution activit under visible light illumination. The Sr doped ZnO/CNTs photocatalyst shows the highest hydrogen evolution rate of 2732.2 μmolh?1g?1, which is 33.7 and 2.83 times higher than pure ZnO and Sr doped ZnO photocatalysts, respectively. The improved hydrogen evolution activity of Sr doped ZnO/CNTs is primarily assigned to high surface area, Sr doping and construction of heterojunction, which can extend the light absorption, decrease the optical band gap and improve the charge separation. Moreover, the underlying photocatalytic mechanism is proposed on the basis of Mott-Schottky study and explains the interfacial charge transfer process from ZnO to CNTs and Sr. This work open new strategies to synthesize CNTs based nanocomposite for hydrogen evolution. 相似文献
22.
Muhammad Shoaib Arif Ali Raza Muhammad Rafiq Mairaj Bibi Rabia Fayyaz Mehvish Naz Umer Javed 《计算机、材料和连续体(英文)》2019,59(3):787-804
In this paper, a reliable stochastic numerical analysis for typhoid fever incorporating with protection against infection has been considered. We have compared the solutions of stochastic and deterministic typhoid fever model. It has been shown that the stochastic typhoid fever model is more realistic as compared to the deterministic typhoid fever model. The effect of threshold number T* hold in stochastic typhoid fever model. The proposed framework of the stochastic non-standard finite difference scheme (SNSFD) preserves all dynamical properties like positivity, bounded-ness and dynamical consistency defined by Mickens, R. E. The stochastic numerical simulation of the model showed that increase in protection leads to low disease prevalence in a population. 相似文献
23.
24.
Rizwana Batool Masood Sadiq Butt Muhammad Tauseef Sultan Farhan Saeed Rabia Naz 《Critical reviews in food science and nutrition》2015,55(2):242-253
The wheel of industrialization that spun throughout the last century resulted in urbanization coupled with modifications in lifestyles and dietary habits. However, the communities living in developing economies are facing many problems related to their diet and health. Amongst, the prevalence of nutritional problems especially protein–energy malnutrition (PEM) and micronutrients deficiencies are the rising issues. Moreover, the immunity or susceptibility to infect-parasitic diseases is also directly linked with the nutritional status of the host. Likewise, disease-related malnutrition that includes an inflammatory component is commonly observed in clinical practice thus affecting the quality of life. The PEM is treatable but early detection is a key for its appropriate management. However, controlling the menace of PEM requires an aggressive partnership between the physician and the dietitian. This review mainly attempts to describe the pathophysiology, prevalence and consequences of PEM and aims to highlight the importance of this clinical syndrome and the recent growth in our understanding of the processes behind its development. Some management strategies/remedies to overcome PEM are also the limelight of the article. In the nutshell, early recognition, prompt management, and robust follow up are critical for best outcomes in preventing and treating PEM. 相似文献
25.
Minimizing transmission delays in vehicular ad hoc networks by optimized placement of road-side unit
Wireless Networks - In a vehicular ad hoc network (VANET), a road side unit (RSU) is a network traffic transmitter statically placed along the route to facilitate communication between vehicles and... 相似文献
26.
In oil and gas industry, the economic considerations determine the selection of low cost materials, in general, carbon steel, for pipelines. However, another type of deformation that is not well understood is its erosion resistance. The objective of this study was to investigate the factors affecting the erosion of carbon steel in a dry sand stream. In this work, a laboratory built test rig was used to erode representative carbon steel plates with accelerated sand streams. The results revealed that the normal incidence sand stream of larger particles and higher impact velocities causes more erosion of the carbon steel. The highest erosion rate of 6.75 ± 0.16 was predicted at an impact angle of 90°, which was three times higher than the erosion rate at impact angle of 30°. Similarly, the erosion caused by the smaller particles was not as severe as the larger particles. The cross-section profiles revealed that the crater depth was increased from 7° to 32.8° with an increase in sand size from 200 µm to 600 µm. The deepest crater of 32.8° was induced by the largest sand size of 600 µm. 相似文献
27.
Nausheen Naz Fawad Tariq Rasheed Ahmed Baloch 《Journal of Failure Analysis and Prevention》2009,9(4):370-379
This case study describes the failure analysis of steel nozzle in which cracking was observed after a circumferential welding
process. The nozzle assembly was made from low C–CrMoV alloy steel that was subsequently single pass butt welded using gas
tungsten arc welding. No cracks were found in visual inspection of the welds; however, X-ray radiography showed small discontinuous
cracks on the surface in the area adjacent to weld bead, i.e. heat affected zone. The welding of nozzle parts made of same
material was a routine process and this type of cracking did not occur in the past. Therefore, it became essential to determine
the root cause of the failure. A detailed investigation including visual examination, non-destructive testing, optical microscopy,
microhardness measurements and residual stress measurements were carried out to find out the primary cause of failure and
to identify actions required to avoid its reoccurrence in future. Results of the investigation revealed that the principal
cause of failure was the presence of coarse untempered martensite in the heat affected zone due to localized heating. The
localized heating was caused by high welding heat input or low welding speed and resulted in the high transformation stresses.
These transformation stresses combined with the thermal stresses and the constraint conditions to cause intergranular brittle
fracture. 相似文献
28.
Farhan Saeed Rabia Shabir Ahmad Muhamad Umair Arshad Bushra Niaz Rizwana Batool Rabia Naz 《International Journal of Food Properties》2016,19(2):420-437
The natural products are gaining immense importance in the domain of nutrition to prevent various maladies and improve the quality of life. Among these, natural exudates are of significant worth as these biochemical compounds are released by various living entities having pharmacological properties for utilization in various drug developments. These natural exudates are the promising source for the discovery of new medications. Numerous bioactive moieties collected by honeybees from exudates and buds of particular trees and plants, considered to be utilized as defensive barrier with special reference to propolis. It generally contains numerous biochemical components, i.e., polyphenols, steroids, terpenoids, and amino acids. They also contain isoferulic acid, sinapinic acid, caffeic acid, and chrysin responsible for antibacterial perspectives. With special attention to propolis, it has been utilized in folk medicines due to several of its therapeutic activities, i.e., antioxidant, antidiabetic, anti-inflammatory, antiviral, and anticancer properties. In this context, it is extensively used in foodstuffs and beverages to improve health related disorders like inflammation, diabetes, heart disease, protects injured gums, and cancer insurgence. Moreover, it has been used to curtail stomatology, gastroenterology, skin lesions, and otorhinolaryngologic and respiration diseases. 相似文献
29.
Muhammad Younis Talpur Syed Tufail Hussain Sherazi Sarfaraz Ahmed Mahesar Saba Naz Huseyin Kara 《European Journal of Lipid Science and Technology》2012,114(2):222-228
The study was carried out to investigate the changes in saturated (SFA), monoene (MUFA), trans (TFA), and polyunsaturated (PUFA) fatty acids and the key fatty acid ratios (SFA/UFA, cis PUFA/SFA, C18:2/C16:0 and C18:3/C16:0) during potato chips frying in canola oil using single bounce attenuated total reflectance FTIR (SB‐ATR‐FTIR) spectroscopy. The data obtained from GC‐FID were used as reference. The calibration of main fat groups and their key fatty acid ratios were developed by partial least square (PLS) regression coefficients using 4000 to 650 cm?1 spectral range. FTIR PLS regression for the predicted SFA, MUFA, TFA, and PUFA were found 0.999, 0.998, 0.998, and 0.999, respectively, whereas for SFA/UFA, cis PUFA/SFA, C18:2/C16:0 and C18:3/C16:0 the regression coefficients were 0.991, 0.997, 0.996, and 0.994, respectively. We conclude that FTIR‐PLS could be used for rapid and accurate assessment of changes in the main fat groups and their key fatty acid ratios ratio during the frying process. Practical applications: FTIR‐ATR method is very simple, rapid, and environmentally friendly. No sample preparation is required and one drop of oil is enough for FTIR analysis. The proposed method could be applied for quick determination of key fatty acid ratios in the food processing industry. 相似文献
30.
The one speed, isotropic scattering, planar Milne’s problem in neutron transport has been a test bed for many methods. We further explore here a numerical solution of the related integral equation. We find that with the use of singularity subtraction, high order quadratures, some interval transformations, and very high precision in all computations, it is possible to obtain results of benchmark accuracy in a straightforward manner. 相似文献