Transient memory response of a thermoelectric half-space with temperature-dependent thermal conductivity and exponentially graded modulii

Magdy A. Ezzat 국제구조공학회 2021 Steel and Composite Structures, An International J Vol.38 No.4

In this work, we consider a problem in the context of thermoelectric materials with memory-dependent derivative for a half space which is assumed to have variable thermal conductivity depending on the temperature. The Lamé’s modulii of the half space material is taken as a function of the vertical distance from the surface of the medium. The surface is traction free and subjected to a time dependent thermal shock. The problem was solved by using the Laplace transform method together with the perturbation technique. The obtained results are discussed and compared with the solution when Lamé’s modulii are constants. Numerical results are computed and represented graphically for the temperature, displacement and stress distributions. Affectability investigation is performed to explore the thermal impacts of a kernel function and a time-delay parameter that are characteristic of memory dependent derivative heat transfer in the behavior of tissue temperature. The correlations are made with the results obtained in the case of the absence of memory-dependent derivative parameters.

Effect of gamma irradiation on polymer modified white sand cement mortar composites

Magdy M. Khattab 한국공업화학회 2014 Journal of Industrial and Engineering Chemistry Vol.20 No.1

This study focuses on the substitution effect of standard sand of cement mortar by different ratios ofwhite sand to prepare white sand cement mortar. The prepared samples were first cured under tap waterfor different time intervals 3, 7, 28 and 90 days. The effect of addition of 10% styrene–acrylic ester as wellas the effect of different doses of gamma rays on the physico-mechanical properties of polymer modifiedwhite sand cement mortar specimens also, discussed. Compression strength test, total porosity andwater absorption percentages were measured. The results were confirmed by scanning electron microscopy, and thermogravimetric analysis studies.

CD163 and c-Met expression in the lymph node and the correlations between elevated levels of serum free light chain and the different clinicopathological parameters of advanced classical Hodgkin’s lymphoma

Magdy Bedewy,Shereen El-Maghraby,Ahmed Bedewy 대한혈액학회 2013 Blood Research Vol.48 No.2

Background Advances in the understanding of Hodgkin’s lymphoma (HL) show various functions of infiltrating immune cells and cytokines in relation to clinical outcomes. The expression of CD163 and c-Met has been suggested to have a role in lymphoid malignancy. Thus, we evaluated the expressions of CD163, c-Met, and serum free light chain (sFLC) in relation to the clinicopathological features of patients with advanced classical HL (cHL). Methods We assessed the expression of CD163 and c-Met in 34 patients with cHL through immunohistochemistry on the lymph node biopsy sections and the levels of pretreatment sFLC were estimated using ELISA. Results High CD163 expression correlated with increased age, B symptoms, International Prognostic Score (IPS) ≥3, mixed cellularity subtype, and low response to treatment. Further, high c-Met expression correlated with increased age at diagnosis, leukocytosis, B symptoms, and lower chance to achieve complete remission. The sFLC levels correlated with increased age at diagnosis, lymphopenia, IPS ≥3, B symptoms, and lower complete remission rates. Conclusion In advanced cHL, increased expression of CD163 and c-Met showed a significant association with adverse prognostic parameters and poor response to treatment. Pretreatment high sFLC level also correlated with poor risk factors, suggesting its use as a candidate prognostic marker. A comprehensive approach for prognostic markers might represent a step towards developing a tailored therapeutic approach for HL.

Thermo-mechanical response of size-dependent piezoelectric materials in thermo-viscoelasticity theory

Magdy A. Ezzat,Zeid I.A. Al-Muhiameed 국제구조공학회 2022 Steel and Composite Structures, An International J Vol.45 No.4

The memory response of nonlocal systematical formulation size-dependent coupling of viscoelastic deformation and thermal fields for piezoelectric materials with dual-phase lag heat conduction law is constructed. The method of the matrix exponential, which constitutes the basis of the state-space approach of modern control theory, is applied to the non-dimensional equations. The resulting formulation together with the Laplace transform technique is applied to solve a problem of a semiinfinite piezoelectric rod subjected to a continuous heat flux with constant time rates. The inversion of the Laplace transforms is carried out using a numerical approach. Some comparisons of the impacts of nonlocal parameters and time-delay constants for various forms of kernel functions on thermal spreads and thermo-viscoelastic response are illustrated graphically.

Occurrence of Three Strains of Cucumber mosaic virus Affecting Tomato inKuwait

Magdy Shaban Montasser,Narjes Haji Dashti,Neda Yousef Ali,Radhika Guleri Bhardwaj,Bader Al-Hamar 한국식물병리학회 2006 Plant Pathology Journal Vol.22 No.1

Three strains of Cucumber mosaic virus (CMV) have been found to cause a lethal disease, referred to as fern leaf syndromes and mild mosaic symptoms in tomato (Lycopersicon esculentum Mill.) crops grown in Kuwait. CMV strains were detected and identified based on host range, symptomatology, serology, electron microscopy, and ribonucleic acid (RNA) electrophoresis in polyacrylamide gels. A high degree of viral genomic heterogeneity was detected among CMV strains isolated in Kuwait, with no apparent correlation to symptomatology in tomato host plants. Two different virus satellites of “CMV associated RNA 5”, designated CARNA 5, were detected in two virus strains that caused both lethal disease and mild symptoms, designated CMV-D1 and CMV-S1 respectively. CARNA5 was not detected in the third CMV strain that caused fern leaf syndromes designated CMV-F. All the three isolated strains were serologically indistinguishable from each other and may belong to one serotype according to Ouchterlony gel diffusion tests. These strains transmitted via aphids (Myzus persicae Sulz) in a non-persistent manner. Physical properties of the virus strains were very similar where thermal inactivation test showed that virus withstood heating for 10 min at 70oC, dilution end point was 10−4, and the longevity in vitro at room temperature was less than 5 days for all virus strains. CMV-D1 and CMV-F were the most devastating diseases spreading in both greenhouse and field-grown tomato where aborted flower buds failed on fruit setting due to the viral infection. This is the first report to isolate three different strains of CMV in Kuwait.

Thermoelectric viscoelastic materials with memory-dependent derivative

Magdy A. Ezzat,Ahmed S. El Karamany,A.A. El-Bary 국제구조공학회 2017 Smart Structures and Systems, An International Jou Vol.19 No.5

A mathematical model of electro-thermoelasticity has been constructed in the context of a new consideration of heat conduction with memory-dependent derivative. The governing coupled equations with time-delay and kernel function, which can be chosen freely according to the necessity of applications, are applied to several concrete problems. The exact solutions for all fields are obtained in the Laplace transform domain for each problem. According to the numerical results and its graphs, conclusion about the proposed model has been constructed. The predictions of the theory are discussed and compared with dynamic classical coupled theory. The result provides a motivation to investigate conducting thermoelectric viscoelastic materials as a new class of applicable materials.

Biological Control of a Severe Viral Strain Using a Benign Viral Satellite RNAAssociated with Cucumber mosaic virus

Magdy Shaban Montasser,Bader Al-Hamar,Radhika Guleri Bhardwaj 한국식물병리학회 2006 Plant Pathology Journal Vol.22 No.2

Two strains of Cucumber mosaic virus (CMV) isolated in Kuwait were confirmed their infectivity based on symptomatology and host range on different cultivars of tomato (Lycopersicon esculentum), tobacco (Nicotiana tabacum L.) and squash (Cucurbita pepo). The pattern of symptoms differed for the two CMV strains in tomato and tobacco, showing severe stunting and mosaic symptoms with one strain designated KU2, and almost symptomless with the other strain designated KU1. A satellite RNA 5 (sat-RNA) was found to be associated with the KU1 strain and was characterized as a benign viral satellite RNA. Using reverse transcription and polymerase chain reaction (RT-PCR) with sat- RNA specific primers, an amplified PCR product of about 160bp was determined and analyzed by gel electrophoresis. This naturally occurring benign viral satellite RNA was successfully used as a biological control agent to protect tomato plants against the severe KU2 strain. Tomato plants grown in plant-growth chambers, were preinoculated with KU1 containing the benign viral satellite and then challenge inoculated with the severe KU2 strain at different time intervals. All plants challenged three weeks after preinoculation showed nearly complete protection from subsequent infection by the severe strain. This biological control technology using plant viruses was found protective and could be successfully established sooner after the preinoculation.

Preparation of membranes based on high-density polyethylene graft copolymers for phosphate anion removal

Magdy M.H. Senna,Yasser K. Abdel-Moneam,Osama A. Gamal,Abdallah Alarifi 한국공업화학회 2013 Journal of Industrial and Engineering Chemistry Vol.19 No.1

This work was undertaken to synthesize graft copolymers that possess functional groups via the radiation-induced grafting of acrylamide onto a high-density polyethylene (HDPE) substrate. The optimum conditions suitable for radiation graft copolymerization were determined. In this regard, the effects of the solvent, the inhibitor concentration, the monomer concentration and the irradiation dose on the grafting yield were investigated. Selected properties of the prepared graft copolymers were investigated to elucidate the possibility of their practical use in the removal of metals and phosphate anions. The effects of different parameters that may affect the metal chelation process, such as pH, metal feed concentration and time of contact, were also studied. A chemically modified membrane loaded with Cu(II) was used for the removal of phosphate ions from aqueous solutions.

Prevalence of Eosinophilic Esophagitis in Adult Patients with Upper Gastrointestinal Symptoms in a Locality in Upper Egypt

Magdy Fouad,Yasser Mahrous Fouad,Hamdy Ahmed Mokareb,Dalia Mohammed Abdel-Rehim 대한소화기내시경학회 2018 Clinical Endoscopy Vol.51 No.4

Background/Aims: Eosinophilic esophagitis (EoE) is gaining importance in the diagnosis of upper gastrointestinal (UGI) symptoms. Diagnosis is based on the clinical presentation of esophageal dysfunction and pathological findings in the absence of other causes oftissue eosinophilia. Our study was designed to evaluate EoE prevalence in patients with UGI symptoms in our locality (El-Minia, Egypt). Methods: This single-center, cross-sectional study recruited all patients with UGI symptoms who agreed for endoscopic evaluation. Esophageal biopsy samples were obtained and histological evaluation for the presence of eosinophils was performed for every patient. EoE was defined when at least 15 eosinophils were present in a single high-power field, in the absence of other causes of esophagealeosinophilia. Results: Between 2013 and 2015, 218 of 476 adult patients with UGI symptoms underwent upper endoscopy after giving consent. Amongthe 218 patients, only 4 (1.87%) had the diagnosis of EoE based on the presence of eosinophils in esophageal biopsies and exclusion ofother causes of esophageal eosinophilia. Three patients with EoE presented mainly with dysphagia (75%) and/or other UGI symptoms,such as heartburn. Conclusions: We observed a low prevalence of EoE in our locality. The diagnosis of EoE should be considered in patients withdysphagia and/or heartburn.

Characterization of electron beam irradiated natural rubber/modified starch composites

Magdy M. Senna,Rasha M. Mohamed,Amira N. Shehab-Eldin,Sabrnal El-Hamouly 한국공업화학회 2012 Journal of Industrial and Engineering Chemistry Vol.18 No.5

The effects of electron beam irradiation on thermal, mechanical and morphological properties of natural rubber/starch blends were investigated. The results of thermogravimetric analysis indicated that the thermal stability of natural rubber was improved by the addition of modified starch and by irradiation. On the other hand, thermal stability of irradiated natural rubber and natural rubber/unmodified starch blends is lower than that of pure natural rubber. The tensile strength of natural rubber (2.01 MPa) was improved to 3.82 MPa with the addition of 5 phr unmodified starch. There was a further increase from 2.01 MPa to 6.44 MPa when 5 phr modified starch was used.