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Analytical solution and numerical simulation of the thermal entrance region problem for laminar flow through a circular pipe

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International Journal of Modeling, Simulation, and Scientific Computing 2020年第2期11卷 69-90页

作者： ali Belhocine oday ibraheem Abdullah Faculty of Mechanical Engineering University of Sciences and the Technology of oran L.P 1505 El-MnaouerUSTO 31000 OranAlgeria System Technologies and Mechanical Design Methodology Hamburg University of TechnologyHamburgGermany

In this paper,the assumptions implicited in Leveque’s approximation are re-examined,and the variation of the temperature and the thickness of the boundary layer were illustrated using the developed *** defining a similarity variable,the governing equations are reduced to a dimensionless equation with an analytic solution in the entrance *** report gives justification for the similarity variable via scaling analysis,details the process of converting to a similarity form,and presents a similarity *** analytical solutions are then checked against numerical solution programming by FoRTRAN code obtained via using Runge-Kutta fourth order(RK4)***,other important thermal results obtained from this analysis,such as;approximate Nusselt number in the thermal entrance region was discussed in detail.A comparison with the previous study available in literature has been done and found an excellent agreement with the published data.

关键词： Thermal entrance region thermal boundary layer dimensionless variables temperature Nusselt number Runge-Kutta method

Analysis of strong refractive effect within 11Li projectile structure

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Chinese Physics C 2021年第2期45卷 414-425页

作者： Kassem o.Behairy M.El-Azab Farid Awad A.ibraheem ola Ramadan M.Anwar Physics Department Aswan UniversityAswan 81528Egypt Physics Department Assiut UniversityAssiut 71516Egypt Physics Department King Khalid UniversityAbhaSaudi Arabia Physics Department Al-Azhar UniversityAssiut 71524Egypt

In the context of the double folding optical model,the strong refractive effect for elastic scattering of 11Li+12C and 11Li+28Si systems at incident energies of 29,50,and 60 MeV/n is *** folded potentials are generated based on a variety of nucleon-nucleon interactions with the suggested density distributions for the halo structure of 11Li *** rearrangement term(RT)of the extended realistic density dependent CDM3Y6 effective interaction is *** imaginary potential was taken in the traditional standard Woods-Saxon *** results for the calculated potentials are obtained,with a slight effect of the RT in CDM3Y6 *** reproduction with a normalization factor close to one for the observed angular distributions of the elastic scattering differential cross section has been achieved using the derived *** obtained reaction cross-section is studied as a guide by extrapolating our calculations and previous results.

关键词： optical model elastic and inelastic scattering halo nuclei folding model refraction effect

Efficient Resource Allocation Algorithm in Uplink oFDM-Based Cognitive Radio Networks

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Computers, Materials & Continua 2023年第5期75卷 3045-3064页

作者： omar Abdulghafoor Musbah Shaat ibraheem Shayea Ahmad Hamood Abdelzahir Abdelmaboud Ashraf osman Ibrahim Fadhil Mukhlif Herish Badal Norafida Ithnin ali Khadim Lwas Electronic&Telecommunications Engineering Department The American University of KurdistanDuhokKurdistan RegionIraq CTTC BarcelonaSpain Faculty of Electrical and Electronics Engineering Istanbul Technical UniversityIstanbulTurkey Department of Information Systems King Khalid UniversityMuhayel AseerSaudi Arabia Faculty of Computing and Informatics University Malaysia SabahKota KinabaluMalaysia Information Assurance and Security Research Group(IASRG) School of ComputingFaculty of EngineeringUniversiti Teknologi MalaysiaJohorMalaysia R&D Ministry of Industry and MineralsBaghdadIraq

The computational complexity of resource allocation processes,in cognitive radio networks(CRNs),is a major issue to be ***,the complicated solution of the optimal algorithm for handling resource allocation in CRNs makes it unsuitable to adopt in real-world applications where both cognitive users,CRs,and primary users,PUs,exist in the identical geographical ***,this work offers a primarily price-based power algorithm to reduce computational complexity in uplink scenarioswhile limiting interference to PUs to allowable ***,this paper,compared to other frameworks proposed in the literature,proposes a two-step approach to reduce the complexity of the proposed mathematical *** the first step,the subcarriers are assigned to the users of the CRN,while the cost function includes a pricing scheme to provide better power control algorithm with improved reliability proposed in the second *** main contribution of this paper is to lessen the complexity of the proposed algorithm and to offer flexibility in controlling the interference produced to the users of the primary networks,which has been achieved by including a pricing function in the proposed cost ***,the performance of the proposed power and subcarrier algorithm is confirmed for orthogonal frequency-division multiplexing(oFDM).Simulation results prove that the performance of the proposed algorithm is better than other algorithms,albeit with a lesser complexity of o(NM)+o(Nlog(N)).

关键词： Cognitive radio resource allocation oFDM pricing

Kinetic Study of Curing Phenol-Formaldehyde/Tannin-Formaldehyde Composite Resins

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Natural Resources 2015年第10期6卷 503-513页

作者： Hussein ali Shnawa ibraheem Kadum ibraheem Ashwaq Aboud Shenta Polymer Research Center University of Basrah Basrah Iraq Department of Chemistry College of Education for Pure Science University of Basrah Basrah Iraq

This work presents a study on the uses of tannin-formadehyde derivative into phenolic resins. Eucalyptus tannins (T) were reacted with formaldehyde to form tannin-formaldehyde resin (TF). Then this derivative was used to prepare tannin-formaldehyde/phenol-formaldehyde resins (TFPF) at 20 and 40 %w/w. The kinetic values of thermal curing of Phenol-formaldehyde (PF), tannin-formaldehyde and tannin-formaldehyde/phenol-formaldehyde resins (TFPF) at 20 and 40 wt% from TF were studied by monitoring the weight changes which occurred in the samples weight during thermosetting process at four temperature (160°C, 180°C, 200°C and 220°C). The total evolved condensation products from curing reactions were about 32% - 36% per sample weight, and the rate of curing reaction constants was ranged between 0.163 %wt·min-1 at 160°C and 0.50 %wt·min-1 at 220°C. The path of TFPF curing and kinetic values indicated that these resins could be cured with the behavior and velocity comparable to that of PF. The activation energy of TFPF cross-linking was higher than that of PF. Increasing TF level to 20% and 40% into PF can reduce the amount of PF curing reactions density and weight loss percentage. The global kinetic properties showed that the TF participated in the thermoset network formation with acceptable activity and performance. The general results of this paper show that the TF is a suitable alternative material for partially replacement into PF resin.

关键词： Phenol-Formaldehyde Tannin-Formaldehyde Curing Reactions Weight Loss Monitoring Kinetic Properties

Andrographolide effect on both Plasmodium falciparum infected and noninfected RBCs membranes

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Asian Pacific Journal of Tropical Medicine 2015年第7期8卷 505-510页

作者： Zaid o ibraheem Abd Majid R Sabariah MN Hasidah MS Al-Zihiry K Yam MF Basir R Pharmacology Unit Department of Human Anatomy Faculty of Medicine and Health Sciences Universiti Putra Malaysia Department of Medical Microbiology and Parasitology Faculty of Medicine and Health Sciences Universiti Putra Malaysia Department of Hematology Faculty of Medicine and Health Sciences Universiti Putra Malaysia School of Bioscience and Biotechnology Faculty of Science and Technology Universiti Kebangsaan Malaysia School of pharmaceutical science Universiti Sains Malaysia

objective: To explore whether its antiplasmodium effect of andrographolide is attributed to its plausible effect on the plasma membrane of both Plasmodium falciparum infected and noninfected RBCs. Methods: Anti-plasmodium effect of andrographolide against Plasmodium falciparum strains was screened using the conventional malaria drug sensitivity assay. The drug was incubated with uninfected RBCs to monitor its effect on their morphology, integrity and osmotic fragility. It was incubated with the plasmodium infected RBCs to monitor its effect on the parasite induced permeation pathways. Its effect on the potential of merozoites to invade new RBCs was tested using merozoite invasion assay. Results: It showed that at andrographolide was innocuous to RBCs at concentrations approach its therapeutic level against plasmodia. Nevertheless, this inertness was dwindled at higher concentrations. Conclusions: In spite of its success to inhibit plasmodium induced permeation pathway and the potential of merozoites to invade new RBCs, its anti-plasmodium effect can't be attributed to these functions as they were attained at concentrations higher than what is required to eradicate the parasite. Consequently, other mechanisms may be associated with its claimed actions.

关键词： Andrographolide Terpenoid Plasmodium falciparum Merozoites Permeation & osmotic fragility

An Investigation of ~4He+^(12)C and ~4He+^(16)o Reactions Using the Cluster Model

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Communications in Theoretical Physics 2012年第7期58卷 135-140页

作者： A.H.Al-Ghamdi Awad A.ibraheem M.El-Azab Farid Physics Department Faculty of ScienceKing Abdul Aziz UniversityJeddahSaudi Arabia Physics Department Al-Azhar UniversityAssiut BranchAssiut 71524Egypt Physics Department King Khalid UniversityAbhaSaudia Arabia Physics Department Assiut UniversityAssiut 71516Egypt

The α-target semimicroscopic single folding potentials have been derived by folding a composite (repul-sive and attractive) effective α-α interaction with the α-cluster distribution density in the target nuclei. The obtained potentials are considered as the real part of the nuclear optical model potentials, while the imaginary parts are phe-nomenologicaly expressed using the Woods-Saxon form. Nine sets of measured experimental data of the 4He+12C and 4 He+16o elastic rainbow scattering over the energy range 80-240 MeV are analyzed using the obtained potentials. The data are successfully reproduced using the extracted potentials. The resulted reaction cross sections are also investigated and compared with the available corresponding data.

关键词： optical model elastic scattering folding potential cluster model

Algal massive growth in relation to water quality and salinity at Damietta,north of Egypt

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Journal of Coastal Life Medicine 2015年第2期 113-121页

作者： Mohamed ali ibraheem Deyab Taha Mohamed El-Katony Botany Department Faculty of ScienceDamietta UniversityNew Damietta CityEgypt

objective:To relate the proliferation and dominance of certain algal species at the Damietta and its relation to water ***:Water and algal biomass were bimonthly sampled from five selected sites at Damietta Province,Egypt during *** were identified and ***,algae and sediment were ***:The physicochemical properties of water showed limited seasonal but substantial local *** high levels of nitrogen and phosphorus and turbidity of water pointed to marked eutrophication,which could enhance massive algal *** temporal fluctuation in temperature,exposure to industrial and domestic sewage and salinity results in succession between blooming algal *** platensis and Chlorella vulgaris alternated in a moderately saline water and oscillatoria agardhii and Mougeotia scalaris in a fresh water body during summer and winter ***,Microcystis aureginosa and Ulva lactuca alternated in a moderately saline site during autumn and summer *** albida dominated a fish pond of brackish water and Dunaliella salina dominated the most saline water over the whole period of ***:Growth of the predominant algal species is correlated to water *** species are of considerable nutritive value,with moderate contents of protein,carbohydrate,macronutrients and micronutrients,which evaluates them for usage as food(green and macroalgae),fodder or bio-fertilizer(cyanophytes).

关键词： Algal growth Water quality Sediment North Damietta Egypt Waste water treatment Algal succession

Assessment of Arterial Stiffening and Vascular Calcifications in End‐Stage Renal Disease Patients

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World Journal of Cardiovascular Diseases 2017年第4期7卷 131-143页

作者： Mahmoud Kamal Elsamman Mohamed Abdel Wahab Ezzat Medhat ibraheem Mohammad Raghda Gamal Mostafa ali Taha ali Hassan Internal Medicine Department Sohag Faculty of Medicine Sohag University Sohag Egypt Diagnostic Radiology Department Sohag Faculty of Medicine Sohag University Sohag Egypt

Background and objective: Epidemiological and clinical studies have shown that vascular calcification and arterial vascular stiffness are associated with all-cause and cardiovascular (CV) mortality in the general populations and end-stage renal disease (ESRD) patients. The objective of this study was the assessment of arterial stiffness and vascular calcification in ESRD patients in Sohag University Hospital. Patients and Methods: In this cross-sectional descriptive study, 100 patients with ESRD (63 males and 37 females) were included. The patients were on regular hemodialysis (HD) for 65.18 ± 50.25 months. Arterial stiffness was measured by brachial pulse pressure (PP). A simple vascular calcification score (SVCS) based on plain radiographic films of pelvis and hands was used for assessment of vascular calcification. The patients undergoing clinical evaluation and serum calcium, phosphorus and parathyroid hormone (PTH) were obtained. Results: PP > 70 mmHg was observed in 24 patients (24%) and vascular calcifications were detected in 50 patients (50%). SVCS ≥ 3 was observed in 36 patients (36%) and 10 patients (10%) had both SVCS ≥ 3 and PP > 70 mmHg. PP > 70 was significantly associated with presence of vascular disease (odds ratio;5, 95% CI = 1.56 - 16.01;P = 0.007). In multivariate analysis, PP > 70 was independently associated with elevated systolic blood pressure (odds ratio;1.34, 95% CI = 1.11 - 1.6;P = 0.002) and serum PTH (odds ratio;1.004, 95% CI = 1 - 1.008;P = 0.03). SVCS ≥ 3 was association with age (odds ratio;1.05, 95% CI = 1.02 - 1.09;P = 0.003) and presence of vascular disease (odds ratio;3.19, 95% CI = 1.3 - 7.85;P = 0.01). Elevated systolic blood pressure was independently associated with SVCS ≥ 3 (odds ratio;1.08, 95% CI = 1.03 - 1.14;P = 0.002). Conclusion: Arterial stiffness and vascular calcifications are common in patients with ESRD on regular hemodialysis. PP and SVCS are simple and inexpensive methods in assessment of vascular calcifications

关键词： Arterial Stiffness Vascular Calcification Pulse Pressure Haemodialysis

磁流体动力压缩黏性流体在多孔介质中的流动分析

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Journal of Central South University 2023年第3期30卷 844-854页

作者： HUSSAIN Shafqat ATIF Shahzada M. SAGHEER Muhammad JAHANGEER ibraheem Department of Mathematics Statistics and PhysicsCollege of Arts and SciencesQatar UniversityP.O.Box 2713DohaQatar Department of Mathematics Capital University of Science and TechnologyIslamabadPakistan

本文通过数值分析,讨论了倾斜磁场效应下压缩黏性流体流动特征的意义。对于高效传热现象,温度方程中还考虑了黏性耗散和焦耳热效应。利用打靶法求解了无量纲守恒方程。对模型中所考虑的特定参数对流体运动、传热能量分配率和表面阻力系... 详细信息

本文通过数值分析,讨论了倾斜磁场效应下压缩黏性流体流动特征的意义。对于高效传热现象,温度方程中还考虑了黏性耗散和焦耳热效应。利用打靶法求解了无量纲守恒方程。对模型中所考虑的特定参数对流体运动、传热能量分配率和表面阻力系数的行为进行了图解和详细讨论。倾斜磁场效应对流体速度和换热速率的影响非常重要。从模拟结果可知,当普朗特常数从1增加到5时,热传导率增加了56%,而当倾斜磁参数γ从π/8增加到π/2时,热传导率下降了9.7%。实验还发现,随着挤压参数的增大,换热速率减小,而下板拉伸参数的增大则趋势相反。

关键词：挤压流黏性流体磁流体动力流吸/注射