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Wyszukujesz frazę "Mohamed, A." wg kryterium: Autor


Tytuł:
Study of big Movement of Temporary Sheet Pile in Elatf Power plant North of Egypt using Finite Element Analysis
Autorzy:
Mohamed, A. A.
Powiązania:
https://bibliotekanauki.pl/articles/115733.pdf
Data publikacji:
2014
Wydawca:
Fundacja na Rzecz Młodych Naukowców
Tematy:
finite element analysis
sheet pile
soil profile
3D analysis
2D analysis
Opis:
The failure of sheet pile walls used for temporary works may cause loss of project construction time and money. The failure can be due to lack of knowledge about the soil conditions or a requirement of three dimension analysis, as it may be important for some cases. In this paper a study was made for a big movement during temporary excavation works using sheet pile walls. A back analysis was made using three and two dimensional finite element analysis as well as simple manual calculation in order to find out the causes of the big movement. The results from the analysis was represented and compared with field data and observation. The results from the two dimensional analysis showed higher values than that from three dimensional analysis and both indicated lower results than that from field observation. However the wall movement values deduced from F.E. indicated possible failure. The performed simple manual calculation indicated also failure. The general conclusion was considered that the failure was due to design mistake.
Źródło:
Challenges of Modern Technology; 2014, 5, 1; 28-33
2082-2863
2353-4419
Pojawia się w:
Challenges of Modern Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A new BEM for modeling and simulation of 3T MDD laser-generated ultrasound stress waves in FGA smart materials
Autorzy:
Fahmy, Mohamed A.
Powiązania:
https://bibliotekanauki.pl/articles/29520102.pdf
Data publikacji:
2021
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
oundary element method
modeling and simulation
three-temperature
memory-dependent derivative
laser ultrasonic
nonlinear thermal stress waves
functionally graded anisotropic
smart materials
Opis:
The goal of this study is to present a new theory known as the three-temperature memory-dependent derivative (MDD) of ultrasound stress waves in functionally graded anisotropic (FGA) smart materials. It is extremely difficult to address the difficulties related to this theory analytically due to its severe nonlinearity. As a result, we suggest a new boundary element method (BEM) to solve such equations. The suggested BEM technique incorporates the benefits of both continuous and discrete descriptions. The numerical results are visually represented to demonstrate the impacts of MDD three temperatures and anisotropy on the ultrasound stress waves in FGA smart materials. The numerical findings verify the proposed methodology’s validity and accuracy. We may conclude that the offered results are useful for comprehending the FGA smart materials. As a result, our findings contribute to the advancement of the industrial applications of FGA smart materials.
Źródło:
Computer Methods in Materials Science; 2021, 21, 2; 95-104
2720-4081
2720-3948
Pojawia się w:
Computer Methods in Materials Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Uncertainty and accuracy of vision-based tracking concerning stereophotogrammetry and noise-floor tests
Autorzy:
Ngeljaratan, Luna
Moustafa, Mohamed A.
Powiązania:
https://bibliotekanauki.pl/articles/2051854.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
stereophotogrammetry
noise-floor
vision-based tracking
displacement
uncertainty
accuracy
Opis:
This work proposes a systematic assessment of stereophotogrammetry and noise-floor tests to characterize and quantify the uncertainty and accuracy of a vision-based tracking system. Two stereophotogrammetry sets with different configurations, i.e., some images are designed and their sensitivity is quantified based on several assessments. The first assessment evaluates the image coordinates, stereo angle and reconstruction errors resulting from the stereophotogrammetry procedure, and the second assessment expresses the uncertainty from the variance and bias errors measured from the noise-floor test. These two assessments quantify the uncertainty, while the accuracy of the vision-based tracking system is assessed from three quasi-static tests on a small-scaled specimen. The difference in each stereophotogrammetry set and configuration, as indicated by the stereophotogrammetry and noise-floor assessment, leads to a significant result hat the first stereophotogrammetry set measures the RMSE of 3.6 mm while the second set identifies only 1.6 mm of RMSE. The results of this work recommend a careful and systematic assessment of stereophotogrammetry and noise-floor test results to quantify the uncertainty before the real test to achieve a high displacement accuracy of the vision-based tracking system.
Źródło:
Metrology and Measurement Systems; 2022, 29, 1; 75-92
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Identification of water treatment plant based on feedforward neural network
Autorzy:
Mohamed, A. F.
Radwa, H. Z.
Powiązania:
https://bibliotekanauki.pl/articles/971051.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
water treatment plant
coagulation process
PID
neural network control
Opis:
Coagulation process is the main process in conventional water treatment process sequence. It influences the following treatment process aspects: maintaining plant efficiency and increasing the quality of the produced water. This is accomplished by adding chemicals to raw water, such as alum sulphate. To secure the appropriate plant performance, a mathematical model is proposed in this paper for the coagulation unit, followed by the development of the control strategy. Classic PID and neural network based controller regulating the process are used. Tests were performed, based on the real data for water treatment, using MATLAB/SIMULINK. Simulation results showed better values for both settling time and overshoot in the case of using neural network based controller than PID.
Źródło:
Control and Cybernetics; 2017, 46, 3; 247-258
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Unconventional alternatives for control of tomato root rot caused by Rhizoctonia solani under greenhouse conditions
Autorzy:
Hamza, A.
Mohamed, A.
Derbalah, A.
Powiązania:
https://bibliotekanauki.pl/articles/66331.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
biological agent
control
tomato
root rot
Rhizoctonia solani
greenhouse condition
plant oil
nanoparticle
Opis:
This study was done to assess the antifungal effect of some biocontrol agents effective microorganisms (EMs1), Pseudomonas fluorescences, and Bacillus pumilus, titanium dioxide (TiO2) nanoparticles, black cumin and wheat germ oils as well as the recommended fungicide (flutolanil) against root rot of tomato. Moreover, gas chromatography-mass spectrometry (GC-MS) examination was completed to identify the bioactive compounds in plant oils (dark cumin and wheat germ). Also the impact of these medicines on some biochemical and growth parameters of tomato was examined. Flutolanil was the best treatment followed by dark cumin, TiO2, EMs1, Pseudomonas fluorescens, Bacillus pumilus and wheat germ oil, individually in both test seasons. The outcomes demonstrated a marked increase in each biochemical character (chlorophyll substance, peroxidase and polyphenoloxidase) and plant development (height and fresh and dry weight) under all the tried treatments in comparison to the controls.
Źródło:
Journal of Plant Protection Research; 2016, 56, 3
1427-4345
Pojawia się w:
Journal of Plant Protection Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental and Computational Vibration Study of Amino Acids
Autorzy:
Mohammed, M. E.
Mohamed, A. M. A.
Powiązania:
https://bibliotekanauki.pl/articles/412478.pdf
Data publikacji:
2013
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Vibrational studies
Amino Acids
semi-empirical methods (PM6 and RM1)
ab initio methods (B3LYP/6-31+G(d)
Opis:
Vibrational studies of amino acids experimentally and theoretically have been performed. The Semi-empirical methods optimization by PM6 and RM1 on the l- and d-amino acids (alanine, phenylalanine, aspartic and glutamic acid), showed no difference in energy between l-and d-isomers. The vibrational frequencies were calculated by semi-emprical methods (PM6 and RM1) and ab initio methods (B3LYP/6-31+G(d) and were scaled down by factors of 0.925 (RM1), 1.09 (PM6) and 0.89 (B3LYP/6-31+G(d)). The calculated and experimental vibrational frequencies have shown good general agreement.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2013, 10, 1; 1-17
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Exploitation of spent nickel-metal hydride (Ni-MH) batteries as a source of value-added products
Autorzy:
Farghal, Fatma E.
Abdel-Khalek, Mohamed A.
Powiązania:
https://bibliotekanauki.pl/articles/2146864.pdf
Data publikacji:
2021
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
nickel–metal hydride
batteries
nickel
recovery
cementation
leaching
recycling
Opis:
Spent Nickel–metal hydride batteries can be sources of valuable metals such as nickel, cobalt, manganese, rare earths and toxic chemicals. The recycling of these materials is necessary from both economic and environmental points of view. In this study the nickel is leached in acid solution followed by precipitation and thermal decomposition or by cementation. The affecting parameters such as acid type and concentration, time, temperature and solid/liquid ratio were investigated. The maximum of leached nickel could be obtained in 3M sulfuric acid at 65°C for 60 min with solid-to-liquid ratio of 30 g L-1. The liquid film is a more suitable model for demonstrating the kinetics of the nickel leaching. Thermal decomposition of the precipitated nickel dimethyl-glyoxime was employed in preparation of nickel oxide. Nickel was separated from aqueous solution by cementation on zinc. The cementation process follows pseudo first-order kinetics and diffusion controlling steps. The yield was 91% of the original nickel content.
Źródło:
Physicochemical Problems of Mineral Processing; 2021, 57, 6; 95--101
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Low Back Muscle Activity in an Automobile Seat with a Lumbar Massage System
Autorzy:
Kolich, M.
Taboun, S. M.
Mohamed, A. I.
Powiązania:
https://bibliotekanauki.pl/articles/90384.pdf
Data publikacji:
2000
Wydawca:
Centralny Instytut Ochrony Pracy
Tematy:
automotive seating
electromyography
low back pain
ból pleców
elektromiografia
masaż
Opis:
This investigation was conducted to determine the effects of a massaging lumbar support system on low back muscle activity. The apparatus included a luxury-level automobile seat, six 10-mm diameter bipolar surface electrodes, an amplifier, an anaiog-to-digital conversion board, data acquisition software, and a personal computer. Six experimental conditions, each involving a variation of massage time, were considered. The dependent variable was the change in the root mean square variation of the EMG signal. One minute of lumbar massage every 5 min was found to have a beneficial effect on low back muscle activity (as compared to no massage). This may prove to be an extremely important result in the quest to combat low back pain attributable to automobile seating.
Źródło:
International Journal of Occupational Safety and Ergonomics; 2000, 6, 1; 113-128
1080-3548
Pojawia się w:
International Journal of Occupational Safety and Ergonomics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of foliar application of Sida compound fertilizer on growth, yield, and fruit chemical composition of "Early Superior" grapevine
Autorzy:
Mohamed, A.-R.M.A.
Abdel-Aziz, F.H.
Mohamed, M.A.
Gobara, A.
Powiązania:
https://bibliotekanauki.pl/articles/2087.pdf
Data publikacji:
2013
Wydawca:
Instytut Ogrodnictwa
Tematy:
foliar application
natural fertilizer
growth
vegetative growth
yield
fruit
chemical composition
grape-vine
Early Superior cultivar
leaf mineral content
Źródło:
Journal of Horticultural Research; 2013, 21, 2
2300-5009
Pojawia się w:
Journal of Horticultural Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The impact of smart transformer on different radialdistribution systems
Autorzy:
Mahmoud, Ibrahem Mohamed A.
Abdelsalam, Tarek Saad
Swief, Rania
Powiązania:
https://bibliotekanauki.pl/articles/1841278.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
smart transformer
smart grid
direct approach
power flow
power loss reduction
inteligentny transformator
inteligentna sieć
bezpośrednie podejście
przepływ mocy
redukcja strat mocy
Opis:
The work is intended to extend the application of a smart transformer on a radialdistribution system. In this paper, an updated algorithm on the backward/forward powerflow is introduced. The so-called direct approach of power flow is employed and analyzed.In addition, the paper focused on integrating a smart transformer to the network and solvingthe updating network also using the direct approach load flow. The solution of the smarttransformer using the direct approach power flow method is quite straightforward. Thismodel is applied to radial distribution systems which are the IEEE 33- and IEEE 69-bussystems as a case study. Also, the paper optimizes the best allocation of the smart transformerto reduce the power losses of the grid.
Źródło:
Archives of Electrical Engineering; 2021, 70, 2; 271-283
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
CuO–water mhd mixed convection analysis and entropy generation minimization in double-lid–driven u-shaped enclosure with discrete heating
Autorzy:
Mliki, Bouchmel
Miri, Rached
Djebali, Ridha
Abbassi, Mohamed A.
Powiązania:
https://bibliotekanauki.pl/articles/2204647.pdf
Data publikacji:
2023
Wydawca:
Politechnika Białostocka. Oficyna Wydawnicza Politechniki Białostockiej
Tematy:
U-shaped enclosure
MHD mixed convection
nanoliquids
double lid-driven cavity
entropy generation
LBM
Opis:
The present study explores magnetic nanoliquid mixed convection in a double lid–driven U-shaped enclosure with discrete heat-ing using the lattice Boltzmann method (LBM) numerical method. The nanoliquid thermal conductivity and viscosity are calculated using the Maxwell and Brinkman models respectively. Nanoliquid magnetohydrodynamics (MHD) and mixed convection are analyzed and entropy generation minimisation has been studied. The presented results for isotherms, stream isolines and entropy generation describe the interaction between the various physical phenomena inherent to the problem including the buoyancy, magnetic and shear forces. The operating parameters’ ranges are: Reynolds number (Re: 1–100), Hartman number (Ha: 0–80), magnetic field inclination (γ: 0°–90°), nanoparticles volume fraction (ϕ: 0–0.04) and inclination angle (α: 0°–90°). It was found that the and the total entropy generation augment by increasing Re, ϕ: and γ. conversely, an opposite effect was obtained by increasing Ha and α. The optimum magnetic field and cavity inclination angles to maximum heat transfer are γ = 90° and α = 0.
Źródło:
Acta Mechanica et Automatica; 2023, 17, 1; 112--123
1898-4088
2300-5319
Pojawia się w:
Acta Mechanica et Automatica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Second law analysis of mhd forced convective nanoliquid flow through a two-dimensional channel
Autorzy:
Miri, Rached
Abbassi, Mohamed A.
Ferhi, Mokhtar
Djebali, Ridha
Powiązania:
https://bibliotekanauki.pl/articles/2204682.pdf
Data publikacji:
2022
Wydawca:
Politechnika Białostocka. Oficyna Wydawnicza Politechniki Białostockiej
Tematy:
MHD
LBM
channel flow
nanoliquids
entropy generation
Brownian motion
Opis:
The present study deals with fluid flow, heat transfer and entropy generation in a two-dimensional channel filled with Cu–water nanoliquid and containing a hot block. The nanoliquid flow is driven along the channel by a constant velocity and a cold temperature at the inlet, and the partially heated horizontal walls. The aim of this work is to study the influence of the most important parameters such as nanoparticle volume fraction (0%≤ϕ≤4%), nanoparticle diameter (5 nm≤dp≤55 nm), Reynolds number (50≤Re≤200), Hartmann number (0≤Ha≤90), magnetic field inclination angle (0≤γ≤π) and Brownian motion on the hydrodynamic and thermal characteristics and entropy generation. We used the lattice Boltzmann method (LBM: SRT-BGK model) to solve the continuity, momentum and energy equations. The obtained results show that the maximum value of the average Nusselt number is found for case (3) when the hot block is placed between the two hot walls. The minimum value is calculated for case (2) when the hot block is placed between the two insulated walls. The increase in Reynolds and Hartmann numbers enhances the heat transfer and the total entropy generation. In addition, the nanoparticle diameter increase reduces the heat transfer and the irreversibility, the impact of the magnetic field inclination angle on the heat transfer and the total entropy generation is investigated, and the Brownian motion enhances the heat transfer and the total entropy generation.
Źródło:
Acta Mechanica et Automatica; 2022, 16, 4; 417--431
1898-4088
2300-5319
Pojawia się w:
Acta Mechanica et Automatica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dynamics of Trade Openness in Sri Lanka
Autorzy:
Mohamed Aslam, A. L.
Powiązania:
https://bibliotekanauki.pl/articles/1178315.pdf
Data publikacji:
2017
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Gross Domestic Product
Money supply
Sri Lanka
Trade openness
Opis:
In Sri Lanka, even it was verbally confirmed that the trade openness occurs the wonder on the economy of Sri Lanka, which was not statistically proofed. This study was to test the trade openness dynamics of the economic growth in Sri Lanka using annual time series data over the period of 1975 to 2014. In this study the following variables were used as variables gross domestic product, which was the proxy variable of the economic growth, the trade openness and the money supply. Furthermore, in order to test the long run relationship between the variables, the Johansen cointegration technique was employed while, the VECM technique was employed to test the short run behaviour of the trade openness. In this study, both techniques confirmed that the trade openness negatively and significantly had the long run relationship with the economic growth. While, the lag values of the trade openness in short run period, jointly had not impacted on the economic growth over the sample period. Finally, this study recommended to the government of Sri Lanka that the export should be increased when they formulate the trade development policy.
Źródło:
World Scientific News; 2017, 81, 2; 94-105
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The history of genome mapping in Fragaria spp.
Autorzy:
Mohamed, A.-R. M. A.-W.
Jecz, T.
Korbin, M.
Powiązania:
https://bibliotekanauki.pl/articles/2139.pdf
Data publikacji:
2014
Wydawca:
Instytut Ogrodnictwa
Tematy:
woodland
strawberry
genome mapping
Fragaria vesca
mapping population
linkage
physical mapping
disease resistance
fruit colour
photoperiodic flower
Źródło:
Journal of Horticultural Research; 2014, 22, 2
2300-5009
Pojawia się w:
Journal of Horticultural Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Potential Application of Used Coffee Grounds in Leather Tanning
Autorzy:
Nasr, Ahmed I.
El Shaer, Mohammed A.
Abd-Elraheem, Mohamed A.
Powiązania:
https://bibliotekanauki.pl/articles/24201785.pdf
Data publikacji:
2023
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
leather properties
tannins
vegetable tanning
Opis:
Safety of environment and human health is an essential requirement of modern industrial techniques. Therefore, using natural agents in tanning industry may emerge as a trusted method to avoid the chemical contamination caused by using traditional chromium salts in tanning process. This study aimed to evaluate the hot water extract of used coffee grounds (UCGs) as a vegetable tanning agent. The collected UCGs were dried and extracted with hot water at 90 °C for 2h. The phytochemical screening properties of UCGs extract were determined. Sufficient amount of extract was prepared to be used in leather tanning. Three groups were tanned with UCGs extract solely at concentrations of 20, 30 or 40% of pelts’ weight, while another three groups were tanned with the same concentrations and then re-tanned with 10% of a synthetic tanning agent “Phenol sulfonates”. On tanned leathers, organoleptic, physical and chemical properties were determined; scanning electron micrographs were depicted to examine the leather surface and collagen fiber bundles. Analysis of UCGs extract revealed that it has good tanning properties, as it contained tannins (14.92%), tannins/non tannins ratio (2.06), hide powder (39.57) and Stiasny number (21.16). The results of leather properties showed that using UCGs extract alone at concentration of 40% achieved the best results for the vegetable tanning where the tanned leather had higher (P<0.05) tensile strength, tearing strength and shrinking temperature than that treated with the lower level of 20% UCGs extract. However, 40% of UCGs extract is highly recommended to be used to accomplish the required shrinkage temperature that should be ≥ 70 °C. UCGs extract could be successfully used as tanning agent in vegetable tanning to produce durable leathers with good fullness; it may be used for different manufacturing products, such as footwear and bags. Moreover, using a combination of UCGs extract at any of the used concentrations with phenol sulfonates 10% led to significant improvement in all studied traits as compared with using UCGs extract alone.
Źródło:
Journal of Ecological Engineering; 2023, 24, 3; 10--19
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł

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