Autor: Mohamed, M. - Prolib Integro

Skocz do pozycji: 1.

Tytuł:: Theoretical Inversion of Amino Acids (Alanine and Aspartic Acid) by Semi-empirical Methods
Autorzy:: Mohamed, M. E.
Tematy:: inversion
alanine
aspartic
semi-empirical methods
AM1; Pokaż więcej
Wydawca:: Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Powiązania:: https://bibliotekanauki.pl/articles/412336.pdf Link otwiera się w nowym oknie
Opis:: The inversion reaction coordinate of free amino acids (alanine, aspartic acid) have been computationally calculated by semi-empirical methods AM1. A transition state for free alanine and aspartic acid were obtained as a three membered ring in which the α-C-H and α-C-CH3 are slightly elongated, 1.2 and 2.17 Å respectively in the alanine transition state. The activation energy of alanine is 77.52 kcal/mol in the gas phase and 76.66 kcal/mol in aqueous phase, and for aspartic acid is 54.87 kcal/mol in the gas phase and 50.86 kcal/mol in aqueous phase.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: The Transient Performance of Partially-Undergrounded Overhead Lines in the Presence of Corona
Autorzy:: Saied, Mohamed M.
Tematy:: distributed parameter circuits
non-uniform lines
power transmission lines
line modeling
transients
power networks
mixed
overhead-cable lines
partial undergrounding
distributions
mathematica; Pokaż więcej
Wydawca:: Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie
Powiązania:: https://bibliotekanauki.pl/articles/262791.pdf Link otwiera się w nowym oknie
Opis:: The paper presents a method for investigating the electromagnetic transients of partially under-grounded high voltage overhead transmission lines in the presence of corona. It is based on a time domain model in which the corona is simulated by distributed voltage-dependent shunt current sources. The line segments and the inserted cable section are represented by a single equivalent transmission element having location-dependent circuit parameters per unit length. The numerical solution of the resulting set of differential equations yields the distributions of the voltage, the longitudinal current and the shunt corona current (per unit length) as functions of location and time. The presented two-, three-dimensional and contour plots proved to be helpful in discussing these distributions and in identifying any eventual current and/or voltage concentrations. The developed computer code in Mathematica can handle any time waveform of the source initiating the transients, any line termination as well as any lengths of the overhead line and cable section.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Synthesis and Spectroscopic Characterization of l-aspartic Acid Complexes with Metals of the Lanthanides Family
Autorzy:: Mohamed, M. E.
Tematy:: L-aspartic acid
Lanthanides (III) complexes
IR and NMR; Pokaż więcej
Wydawca:: Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Powiązania:: https://bibliotekanauki.pl/articles/412075.pdf Link otwiera się w nowym oknie
Opis:: The complexes between l-aspartic acid and metals of lanthanide series (La3+, Pr3+, Eu3+, Gd3+) have been prepared and characterized using a variety of techniques including, infrared spectroscopy, 1H NMR, 13C NMR, elemental analysis and metal contents. The sought metal effect on the electronic environment of the chiral carbon and its neighbouring atoms was observed in case of Europium and Praseodymium. The 13C downfield shift indicates a lower electron density at the carbon with consequent downfield shift observed on the ?-H attached to it increasing its acidity.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: Impact of addition oxy-hydrogen gas (HHO) on vehicle engines performance and emissions
Autorzy:: Nabil, Tamer
Khairat Dawood, Mohamed M.
Tematy:: HHO gas
engine performance
gas emissions
gaz HHO
wydajność silnika
emisja gazów; Pokaż więcej
Wydawca:: Politechnika Koszalińska. Wydawnictwo Uczelniane
Powiązania:: https://bibliotekanauki.pl/articles/95358.pdf Link otwiera się w nowym oknie
Opis:: The electrolysis process of water produces oxy-hydrogen (HHO) gas that can be used as an energy source to solve the shortage problem of fossil fuel and reduces the exhaust emissions of greenhouse gases from vehicles engines. In this study, HHO dry cell generator was designed, fabricated and tested experimentally to investigate its performance. The hybrid internal combustion engines using HHO gas is considered one of the most important studied applications. The vehicle engines performance and gas emissions are investigated for two different engines; 150CC with carburetor and 1300CC with Electronic Control Unit (ECU). The results recorded the consumption of the fuel is reduced by 14.8% for 150CC engine and 16.3% for 1300CC engine. HHO gas reduced the emission gases by 33% and 24.5% reduction in CO and 27.4% and 21% reduction in HC for 150CC and 1300CC engines respectively. HHO gas can be efficient used as a secondary fuel for vehicle engines.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 5.

Tytuł:: Cloud Cooperated Heterogeneous Cellular Networks for Delayed Offloading using Millimeter Wave Gates
Autorzy:: Mohamed, E. M.
Tematy:: millimeter wave
delayed offloading
CC-HetNet
ANDSF
C/U splitting; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/227204.pdf Link otwiera się w nowym oknie
Opis:: Increasing the capacity of wireless cellular network is one of the major challenges for the coming years. A lot of research works have been done to exploit the ultra-wide band of millimeter wave (mmWave) and integrate it into future cellular networks. In this paper, to efficiently utilize the mmWave band while reducing the total deployment cost, we propose to deploy the mmWave access in the form of ultra-high capacity mmWave gates distributed in the coverage area of the macro basestation (Macro BS). Delayed offloading is also proposed to proficiently exploit the gates and relax the demand of deploying a large number of them. Furthermore, a mobility-aware weighted proportional fair (WPF) user scheduling is proposed to maximize the intra-gate offloading efficiency while maintaining the longterm offloading fairness among the users inside the gate. To efficiently link the mmWave gates with the Macro BS in a unified cellular network structure, a cloud cooperated heterogeneous cellular network (CC-HetNet) is proposed. In which, the gates and the Macro BS are linked to the centralized radio access network (C-RAN) via high-speed backhaul links. Using the concept of control/user (C/U) plane splitting, signaling information is sent to the UEs through the wide coverage Macro BS, and most of users’ delayed traffic is offloaded through the ultra-high capacity mmWave gates. An enhanced access network discovery and selection function (eANDSF) based on a network wide proportional fair criterion is proposed to discover and select an optimal mmWave gate to associate a user with delayed traffic. It is interesting to find out that a mmWave gate consisting of only 4 mmWave access points (APs) can offload up to 70 GB of delayed traffic within 25 sec, which reduces the energy consumption of a user equipment (UE) by 99.6 % compared to the case of only using Macro BS without gate offloading. Also, more than a double increase in total gates offloaded bytes is obtained using the proposed eANDSF over using the conventional ANDSF proposed by 3GPP due to the optimality in selecting the associating gate.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 6.

Tytuł:: Semi-analytical scheme with its stability analysis for solving the fractional-order predator-prey equations by using Laplace-VIM
Autorzy:: Adel, Mohamed
Sweilam, Nasser H.
Khader, Mohamed M.
Tematy:: fractional predator-prey equations
Caputo-Fabrizio fractional derivative operator
Laplace transform
fixed point
VIM
równanie ułamkowe
pochodna ułamkowa Caputo-Fabrizio
równanie Laplace’a
metoda Laplace’a
punkt stały; Pokaż więcej
Wydawca:: Politechnika Częstochowska. Wydawnictwo Politechniki Częstochowskiej
Powiązania:: https://bibliotekanauki.pl/articles/58907611.pdf Link otwiera się w nowym oknie
Opis:: The article’s goal is to implement a semi-analytical technique named, the Laplace variational iteration method (LVIM), which is the combination of VIM and Laplace transform method. Although both the Laplace transform method and VIM cannot be applied to some nonlinear fractional differential equations (FDEs) individually, this combination will give a fast-convergent solution to the problem under study. The proposed scheme is used to numerically solve a biodynamic system called the Lotka-Volterra system, i.e. Predator-Prey Equations (PPEs). The system of FDEs can be used to represent this scenario, as well as the Caputo-Fabrizio fractional derivative will be used throughout the study. By assessing the residual error function, we can confirm that the given procedure is effective and accurate. The outcomes demonstrate that the technique used is an effective tool for simulating such models.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 7.

Tytuł:: On the stability analysis for a semi-analytical scheme for solving the fractional order blood ethanol concentration system using LVIM
Autorzy:: Adel, Mohamed
Sweilam, Nasser H.
Khader, Mohamed M.
Tematy:: fractional blood ethanol concentration system
Caputo-Fabrizio fractional derivative operator
Laplace transform
VIM
fixed point theorem
etanol
ułamkowa Caputo-Fabrizio
transformata Laplace'a
twierdzenie o punkcie stałym; Pokaż więcej
Wydawca:: Politechnika Częstochowska. Wydawnictwo Politechniki Częstochowskiej
Powiązania:: https://bibliotekanauki.pl/articles/58907610.pdf Link otwiera się w nowym oknie
Opis:: The purpose of this article is to present the Laplace variational iteration method, which combines the VIM with the Laplace transform approach (LVIM). This combination will result in a better and more quickly convergent sequence since nonlinear fractional differential equations (FDEs) cannot be solved using the Laplace transform. With the use of the fixed point theory, the stability analysis is specifically discussed and examined. The blood ethanol concentration system is solved numerically by using the suggested scheme. This model can be represented by a system of FDEs. The investigation will emploi the Caputo-Fabrizio fractional derivative. To provide a more in-depth study of this model, we have taken it in its fractional form so that we can more accurately follow the behavior of the solution in the future and history based on the memory effect of fractional derivatives. We determine the accuracy and efficiency of the provided process by evaluating the absolute errors, and a comparison with the existing published work. The results show that the approach is a useful tool for simulating this model.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 8.

Tytuł:: Evaluation of modified hard fluors for biscuit making
Przydatność zmodyfikowanej mąki pochodzącej z twardej pszenicy do produkcji ciastek
Autorzy:: Damir, A.A.
Salem, A.
Mohamed, M.S.
Wydawca:: Instytut Rozrodu Zwierząt i Badań Żywności Polskiej Akademii Nauk w Olsztynie
Powiązania:: https://bibliotekanauki.pl/articles/10314.pdf Link otwiera się w nowym oknie
Opis:: Przeprowadzono próby modyfikacji mąki pochodzącej z pszenicy twardej w celu uzdatnienia jej jako surowca do produkcji ciastek. W tym celu do mąki mocnej dodawano w różnych stężeniach metadwusiarczyn sodu, siarczyn, skrobię oraz mąkę słabą z mąką słodową. Jako kryterium zmian jakościowych służyły wskaźniki reologiczne ciasta. Potrzebne zmiany jakościowe we właściwościach reologicznych uzyskano przez dodatek 228 mg/kg S₂O₅, 64 mg/kg SO₃, 5% skrobi lub 50% mąki słabej. Mieszanina 20% słodu i 64 mg/kg SO₃ powodowała zmiękczenie ciasta i wzrost jego rozciągliwości, co w efekcie dało najlepszy surowiec do otrzymywania ciastek o wysokiej jakości organoleptycznej. Zmiękczenie ciasta pod wpływem czynników redukujących i słodu powiązane było z ilością wolnych grup SH. Oprócz poprawy jakości uzyskano 27% wzrost objętości ciastek.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 9.

Tytuł:: Radiation dose associated with multi-detector 64-slice computed tomography brain examinations in Khartoum State, Sudan
Autorzy:: Babikir, Esameldeen
Elmahdi, Ali
Abuzaid, Mohamed M.
Sulieman, Abdelmoneim
Opis:: Background: Radiation exposure due to computed tomography (CT) has become an important issue, as the number of CT examinations has been increasing worldwide. Radiation doses associated with CT are higher in comparison to other imaging procedures. CT-related radiation doses should be monitored and controlled in order to ensure reduction of radiation exposure and optimization of image quality. The aim of this study was to evaluate radiation doses in adult patient who underwent routine CT brain examinations, and to assess how CT scanning protocols affect patient doses in practice. Material/Methods: A total of 118 patients underwent brain CT at two radiology departments equipped with 64-slice CT scanners, Khartoum, Sudan. Patient doses regarding weighted CT dose index (CTDIw) and dose length product (DLP) values were recorded. Quality control tests were performed for both scanners. Results: The mean CTDIw values ranged from 62.9 to 65.8 mGy, DLP values ranged from 1003.7 to 1192.5 mGy, and the effective dose varied from 2.4 to 3.7 mSv. Conclusions: Patient doses in this study was higher compared to previous research, suggesting that patients exposed to unnecessary radiation. Therefore, optimization of radiation doses with the use of specified imaging protocols, well-documented indications for CT, training of technicians, and quality control programs will reduce the necessary radiation doses. Establishment of the diagnostic reference level is recommended for further dose reduction.
Dostawca treści:: Repozytorium Uniwersytetu Jagiellońskiego

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Skocz do pozycji: 10.

Tytuł:: Assessment of submerged floor water jets to minimize the scour downstream from a stepped spillway
Autorzy:: Ibrahim, Mohamed M.
Diwedar, Al Sayed Ibrahim
Ibraheem, Ahmed Mahmoud
Tematy:: floor jets
flume
jet rows
stepped spillway
scour depth
scour length; Pokaż więcej
Wydawca:: Instytut Technologiczno-Przyrodniczy
Powiązania:: https://bibliotekanauki.pl/articles/1841974.pdf Link otwiera się w nowym oknie
Opis:: Because of hydraulic jump, the scour downstream a stepped spillway is the most confusing issue that endangers the overall stability of the spillway. In this paper, thirty-six exploratory runs are described to explore the impact of utilizing submerged water jets fixed in the stilling basin of a stepped spillway on the downstream scour measurements under various flow conditions. A smooth apron where the water jets are disabled is incorporated to characterize the impact of adjustments studied. Trials are performed utilizing different upstream discharges, jets arrangements, and tailwater depths. The results are analyzed and graphically presented. The experimental data are contrasted to a scour formulae developed by other specialists. Outcomes indicated that by utilizing submerged floor water jets, the maximum scour depth is decreased between 14.3 and 36.0%. Additionally, the maximum scour length is reduced by 9.7 to 42.3%. Finally, involving regression analysis, simple formulas are developed to estimate different scour parameters.
Dostawca treści:: Biblioteka Nauki

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