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排序方式: 共有616条查询结果,搜索用时 15 毫秒
101.
Adnan Umar Khan Naveed Ahmed Syed Tauseef Mohyud-Din Ilyas Khan El-Sayed M. Sherif 《计算机、材料和连续体(英文)》2021,67(1):477-489
The investigation of local thermal transport rate in the nanolubricants is significant. These lubricants are broadly used in environmental pollution, mechanical engineering and in the paint industry due to high thermal performance rate. Therefore, thermal transport in ZnO-SAE50 nanolubricant under the impacts of heat generation/absorption is conducted. The colloidal suspension is flowing between parallel stretching disks in which the lower disk is positioned at z = 0 and upper disk apart from distance d. The problem is transformed in dimensionless version via described similarity transforms. In the next stage, an analytical technique (VPM) is implemented for the solution purpose. The graphical results against multiple flow parameters were furnished over the region of interest and explained comprehensively. It is imperative to mention that the results are plotted for ZnO-SAE50 and conventional liquid as well. Further, rapid motion of the fluid is perceived against high Reynolds and γ parameters. The wall shear stresses at the upper end rises for multiple Reynolds and γ while; decrement is detected at the lower end. The significant contribution of an internal heat source is noted for thermal performance rate at the upper end. Foremost, the local heat transport rate declines at the lower disk. By altering Reynolds number, prompt heat transfer rate is gained at the upper disk and increasing behavior of the local heat transport rate is slow at the lower disk. From the study, it is concluded that the nanolubricants have high thermal characteristics. Therefore, such fluids are reliable to use in above stated areas. 相似文献
102.
In this study, magnetohydrodynamic (MHD) three-dimensional (3D)
flow of alumina (Al2O3) and copper (Cu) nanoparticles of an electrically conducting incompressible fluid in a rotating frame has been investigated. The shrinking
surface generates the flow that also has been examined. The single-phase (i.e.,
Tiwari and Das) model is implemented for the hybrid nanofluid transport phenomena. Results for alumina and copper nanomaterials in the water base fluid are
achieved. Boundary layer approximations are used to reduce governing partial
differential (PDEs) system into the system of the ordinary differential equations
(ODEs). The three-stage Lobatto IIIa method in bvp4c solver is applied for
solutions of the governing model. Graphical results have been shown to
examine how velocity and temperature fields are influenced by various applied
parameters. It has been found that there are two branches for certain values of
the suction/injection parameter b: The rise in copper volumetric concentration
improved the velocity of hybrid nanofluid in the upper branch. The heat transfer
rate improved for the case of hybrid nanofluid as compared to the viscous fluid
and simple nanofluid. 相似文献
103.
Waleed El Nahal Hatim G. Zaini Raghad H. Zaini Sherif S. M. Ghoneim Ashraf Mohamed Ali Hassan 《计算机、材料和连续体(英文)》2022,73(1):33-50
Recently, many researchers have tried to develop a robust, fast, and accurate algorithm. This algorithm is for eye-tracking and detecting pupil position in many applications such as head-mounted eye tracking, gaze-based human-computer interaction, medical applications (such as deaf and diabetes patients), and attention analysis. Many real-world conditions challenge the eye appearance, such as illumination, reflections, and occasions. On the other hand, individual differences in eye physiology and other sources of noise, such as contact lenses or make-up. The present work introduces a robust pupil detection algorithm with and higher accuracy than the previous attempts for real-time analytics applications. The proposed circular hough transform with morphing canny edge detection for Pupillometery (CHMCEP) algorithm can detect even the blurred or noisy images by using different filtering methods in the pre-processing or start phase to remove the blur and noise and finally the second filtering process before the circular Hough transform for the center fitting to make sure better accuracy. The performance of the proposed CHMCEP algorithm was tested against recent pupil detection methods. Simulations and results show that the proposed CHMCEP algorithm achieved detection rates of 87.11, 78.54, 58, and 78 according to Świrski, ExCuSe, Else, and labeled pupils in the wild (LPW) data sets, respectively. These results show that the proposed approach performs better than the other pupil detection methods by a large margin by providing exact and robust pupil positions on challenging ordinary eye pictures. 相似文献
104.
Effects of 2-amino-5-ethylthio-1,3,4-thiadiazole (AETD) on copper corrosion as a corrosion inhibitor in an aerated acidic pickling solution of 0.50 M HCl have been investigated using gravimetric and electrochemical techniques. Weight losses of copper coupons in 0.50 M HCl measured after varied exposure periods of 2–12 h indicate that the addition of AETD significantly decreases the dissolution rate and the effect increases upon increasing its concentration. Results of potentiodynamic polarization experiments show a large decrease in cathodic, anodic, and corrosion currents due to the presence of the organic molecules. Potentiostatic current–time measurements at 200 mV versus Ag/AgCl for 120 min, scanning electron microscope (SEM), and energy dispersive X-ray (EDX) investigations also indicate that AETD greatly lowers the dissolution currents as a result of its strong adsorption onto the copper surface preventing it from being corroded easily. EIS measurements confirmed that the charge transfer resistance increases and mass transport decreases in the presence of AETD upon increasing its concentration. 相似文献
105.
Sherif Elbasuney Amir Elsaidy Mohamed Kassem Hesham Tantawy 《Journal of Inorganic and Organometallic Polymers and Materials》2018,28(5):1718-1727
Infrared (IR) guided missiles are real threat; they caused 90% of aircraft damage. Fluorocarbon polymer nanocomposite based on super-thermites can offer superior thermal signature to countermeasure IR guided missile seekers. This study reports on the sustainable fabrication of mono-dispersed colloidal Fe2O3 nanoparticles with 3 nm average particle size. Fe2O3 nanoparticles were dispersed in acetone for subsequent integration in fluorocarbon polymer. The impact of Fe2O3 content on thermal signature was evaluated using (FT-MIR 2–6 μm) spectrophotometer. Nanocomposite polymer with 8 wt% Fe2O3 offered an increase in the average intensity of α (2–3 μm) and β (4–5 μm) bands by 50 and 85% respectively to that of reference formulation. Quantification of stimulated emitting species in the combustion flame was conducted using ICT thermodynamic code. The developed nanothermite particles extended the primary reaction zone by 183%. Full discussions about combustion zones with associated exothermic chemical reactions have been represented. 相似文献
106.
Efficiency Enhancement of Single‐Walled Carbon Nanotube‐Silicon Heterojunction Solar Cells Using Microwave‐Exfoliated Few‐Layer Black Phosphorus 下载免费PDF全文
Munkhjargal Bat‐Erdene Munkhbayar Batmunkh Sherif Abdulkader Tawfik Marco Fronzi Michael J. Ford Cameron J. Shearer LePing Yu Mahnaz Dadkhah Jason R. Gascooke Christopher T. Gibson Joseph G. Shapter 《Advanced functional materials》2017,27(48)
Carbon nanotube‐silicon (CNT‐Si)‐based heterojunction solar cells (HJSCs) are a promising photovoltaic (PV) system. Herein, few‐layer black phosphorus (FL‐BP) sheets are produced in N‐methyl‐2‐pyrrolidone (NMP) using microwave‐assisted liquid‐phase exfoliation and introduced into the CNTs‐Si‐based HJSCs for the first time. The NMP‐based FL‐BP sheets remain stable after mixing with aqueous CNT dispersion for device fabrication. Due to their unique 2D structure and p‐type dominated conduction, the FL‐BP/NMP incorporated CNT‐Si devices show an impressive improvement in the power conversion efficiency from 7.52% (control CNT‐Si cell) to 9.37%. Our density‐functional theory calculation reveals that lowest unoccupied molecular orbital (LUMO) of FL‐BP is higher in energy than that of single‐walled CNT. Therefore, we observed a reduction in the orbitals localized on FL‐BP upon highest occupied molecular orbital to LUMO transition, which corresponds to an improved charge transport. This study opens a new avenue in utilizing 2D phosphorene nanosheets for next‐generation PVs. 相似文献
107.
Synthesis,Characterization, and Evaluation of Ethoxylated Lauryl-Myrisityl Alcohol Nonionic Surfactants as Wetting Agents,Anti-Foamers,and Minimum Film Forming Temperature Reducers in Emulsion Polymer Lattices 下载免费PDF全文
M. A. Abd El-Ghaffar M. H. Sherif A. Taher El-Habab 《Journal of surfactants and detergents》2017,20(1):117-128
Two nonionic FAEO (fatty alcohol ethoxylated) surfactants with varying solubility were obtained by the reaction of lauryl-myrisityl alcohol (LMA) with ethylene oxide to yield lauryl-myristyl/alcohol ethoxylated with 3 and 31 mol of ethylene oxide by changing the length of polyethylene glycol segment. The prepared surfactants, designated as LMAEO-3 and LMAEO-31, were characterized for their structures using spectroscopic measurements; in addition, their surface properties were investigated. The results indicated that LMAEO-31 exhibits excellent surface activity. Evaluation of the surfactants as wetting agents, anti-foamers, and minimum film forming temperature (MFFT) reducer in emulsion polymer lattices achieved promising results indicating high performance in the mentioned industrial applications. 相似文献
108.
Biswas G Manders EJ Ramirez J Mahadevan N Abdelwahed S 《Habitation (Elmsford, N.Y.)》2004,10(1):21-37
This article describes methods for online model-based diagnosis of subsystems of the advanced life support system (ALS). The diagnosis methodology is tailored to detect, isolate, and identify faults in components of the system quickly so that fault-adaptive control techniques can be applied to maintain system operation without interruption. We describe the components of our hybrid modeling scheme and the diagnosis methodology, and then demonstrate the effectiveness of this methodology by building a detailed model of the reverse osmosis (RO) system of the water recovery system (WRS) of the ALS. This model is validated with real data collected from an experimental testbed at NASA JSC. A number of diagnosis experiments run on simulated faulty data are presented and the results are discussed. 相似文献
109.
110.