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Analysis of Cutout Fiber as Source of Delamination in Composites System Using FEm

Journal of Chemistry and Chemical Engineering 2013年第1期7卷 34-39页

作者： ramadan A. Al-madani Aimen. Elmahmody m. Jamaz Engineering Faculty Al-Jabel Algharbi University Gharian 00218 Libya Engineering Faculty Tripoli University Tripoli 00218 Libya Academy of Graduate Studies Tripoli 00218 Libya

Delamination in composite structures can be a serious threat to the safety of the structure. Delamination leads to loss of stiffness and strength of laminates under some conditions. This is particularly so in the case of compressively loaded structures as the loss of stiffness may lead to separation of layers, the consequences of which can be catastrophic. Causes of delamination are many. In aerospace applications, this includes manufacturing defects, as well as operationally induced defects such as bird strikes, hits due to runway debris and tool drops. In this work one of the main causes of delamination that is dealt with, is the one that redistribution of the stress state due to some defects all mostly like here is broken single fiber （cutout fiber） in composite system.already initiated by one of the above causes. When a laminate is subjected to in-plane tension, the effects of delamination on the stiffness and strength may be characterized by analytical results concerning the onset of delamination growth and its subsequent development. many of the analytical treatments deal with just free-edge delamination. In m.an time the redistribution and the gradient of the stress state in composite system is playing an important role for causing delamination. The main task of this work is to analyze single fiber with and without cutout embedded in matrix. Different FE models were generated, from the results, the redistribution of the stress state around the defected fiber were presented and discussed. Finally concluded remarks were indicated.

关键词： Composite materials interlaminar stress delamination.

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A Transmission Line Fault Classification Approach by Support Vector machines

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Journal of Energy and Power Engineering 2011年第3期5卷 268-274页

作者： A.m. Ibrahim.a.Y. Abdelaziz S.F. mekhamer m. ramadan Electrical Power and machines Department Faculty of Engineering Ain Shams University Cairo Egypt

This paper presents an approach for shunt faults detection and classification in transmission line using Support Vector machine （SVm）. The paper com.ares between using three line post-fault current samples for one-half cycle and one-fourth cycle from the inception of the fault as inputs for SVm. Two SVms are used, first SVmabc is used for faulty phase detection and second SVmg is used for ground detection. SVms with polynom.al kernel with different degrees are used to obtain the best classification score. The classification test results show that the proposed method is accurate and reliable.

关键词： Transmission line protection fault detection fault classification support vector machine.

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Effect of metformin on Endometrial Thickness and Subendometrial Flow Patterns in Anovulatory Patients with Polycystic Ovarian Syndrome

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Open Journal of Obstetrics and Gynecology 2018年第14期8卷 1465-1475页

作者： Waleed m. Khalaf Sherif A. Akl Rania R. ramadan Obstetrics and Gynecology Department Faculty of Medicine Ain Shams University Cairo Egypt misr University for Sciences and Technology Giza Egypt

Background: Polycystic ovarian syndrome (PCOS) is considered the commonest endocrinological disorder affecting reproductive aged women. PCOS compromises fertility through various pathways. These pathways include hyperandrogenism, insulin resistance and impedance of the uterine and endometrial blood flow. metformin improves the blood flow to the endometrium. It acts by reducing androgen level and correction of insulin resistance. Endometrial vascular indices were evaluated in this study to evaluate endometrial receptivity in anovulatory patients with PCOS. Aim of the Work: To evaluate the outcome of metformin administration in anovulatory patients with PCOS and its effect on the endometrium. This included its role in ovulation and improvement of pregnancy rates. Patients and methods: This study included 85 patients from.ain Shams University outpatient infertility clinics from 1st of January, 2018 till 30th of June, 2018. We investigated these patients before treatment with ultrasound on day 14, 21. We evaluated endometrial thickness, uterine artery flow pattern, endometrial and subendometrial flow patterns. The patients received metformin 500 mg three times per day for three months. After this duration, we reevaluated them by ultrasound at days 14, 21. Results: metformin therapy resulted in a significant increase of endometrial thickness and had a significant decrease on uterine, endometrial and subendometrial resistance index (R.I) and pulsatility index (P.I) at day 14, 21 com.ared to pre-treatment values indicating better blood flow. Conclusion: metformin therapy resulted in improvement of endometrial flow patterns. Also, it resulted in increase in endometrial thickness and improvement of uterine artery flow.

关键词： Endometrial Thickness Subendometrial Flow Patterns Anovulatory PCOS metformin

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Flexible Reduced Logarithmic-Inverse Lomax Distribution with Application for Bladder Cancer

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Open Journal of modelling and Simulation 2021年第4期9卷 351-369页

作者： mohamed m. Buzaridah Dina A. ramadan Beih S. El-Desouky Department of mathematics Faculty of Science Mansoura University Mansoura Egypt

In this paper, a new method for adding parameters to a well-established distribution to obtain more flexible new families of distributions is applied to the inverse Lomax distribution (IFD). This method is known by the flexible reduced logarithmic-X family of distribution (FRL-X). The proposed distribution can be called a flexible reduced logarithmic-inverse Lomax distribution (FRL-IL). The statistical and reliability properties of the proposed models are studied including moments, order statistics, moment generating function, and quantile function. The estimation of the model parameters by maximum likelihood and the observed information matrix are also discussed. In order to assess the potential of the newly created distribution. The extended model is applied to real data and the results are given and compared to other models.

关键词： Lomax Distribution Inverse Lomax Distribution Hazard Rate Function maximum Likelihood Estimators Skewness and Kurtosis moment Generating Function

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The Length-weight Relationship of Diplodus vulgaris ／（Teleostei, Sparidae） from Benghazi Coast （Libya）

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Journal of Life Sciences 2016年第2期10卷 59-65页

作者： Abdalla Nassir Elawad Anwaar m. Saeid ramadan A. S. Ali Omar AI-mukhtar University Faculty of Science-Department of Zoology Marine Biology Branch

Length-weight relationships （LWRs） were determined for fish species Diplodus vulgaris from the Benghazi coast along the eastern mediterranean Sea coast of Libya. Samples were collected using trammel nets. The parameters a and b from the LWR formula W = aLb were estimated. The values of the exponent b of the length-weight relationships in all categories range between 2.295 in September to 3.208 in August. The total number of fish samples investigated were 290, from which 179 were males, 41 females and 70 fishes im.ature. The sex ratio male to female were 4.3：1. In January, August and Females the slope ＂b＂ close to equal 3, were the categories exhibited isometric relationship, in September, October and November were slope ＂b＂ not equal 3, which the categories exhibited negative allometric relationship. The m.an observed length of male was 18.29 cm.at m.an observed weight 114.8 g, and m.an observed length of female was 19.15 cm.at m.an observed weight 133.97 *** general equation for the length-weight relationship for both sex was： W = 0.03835L277, for male was： W = 0.036 L274, for female, W = 0.016 L302.

关键词： Diplodus vulgaris allometric ismeteric Benghazi coast sex ratio.

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Air Quality Indices, Sources and Im.act on Human Health of Pm10and Pm2.5in Alexandria Governorate, Egypt

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Journal of Environmental Protection 2018年第12期9卷 1237-1261页

作者： Ashraf A. Zahran m. Ismail Ibrahim.alaa El-Din ramadan m. m. Ibrahim Department of Natural Resources and Planning to Development Environmental Studies and Research Institute El Sadat University Sadat City Egypt matroh Branch Affairs Alexandria University Alexandria Egypt Faculty of Science Alexandria University Alexandria Egypt Environmental Sciences Faculty of Science Alexandria University Alexandria Egypt

In this study, Pm10 and Pm2.5 were m.asured in seven sites representing different activities (the same sites of EEAA monitoring stations) in addition to eighth site that used as a background. All results were higher than AQLs of EEAA, US/EPA, and EC although Pm10 and Pm2.5 are considered to be a direct cause of cardiovascular diseases as well as lead to death and it may be a reason for a number of chest diseases in short-term.as well as long-term. Results were com.ared to the Air Quality Forecast system which developed by EEAA and AQI which created by US/EPA was calculated for some Pm10 and Pm2.5. Probable potential anthropogenic sources for such high concentrations of Pm included unpaved roads, indiscriminate demolition and construction work, industrial activities, and solid wastes. This study resulted in a number of suggestions and recommendations include: 1) Implementation of integrated ISO 26000 and ISO 14001, 2) EImP/EEAA monitoring stations need restructuring plan to cover all areas in Alexandria, 3) EImP/EEAA must be supported with Pm2.5 monitors, 4) Pm control systems must be used in all industrial activities to reduce Pm pollution from the source, 5) AQL of Pm2.5 in the ambient environment must be reduced and it must be included in the working environment parameters, 6) Environmental law must be applied strictly, and 7) multidisciplinary co-operation especially between environment and public health specialists must be increased.

关键词： Air Pollution Pm Pm10 Pm2.5 Air Quality Forecast Air Quality Index Human Health

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Rendering of Cellulose Acetate Fabrics Self-Cleaning through Treatment with TiO2Nano Particles

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materials Sciences and Applications 2012年第12期3卷 872-879页

作者： m. A. ramadan W. m. Raslan E. m. El-Khatib A. Hebeish National Research Centre Textile Research Division Cairo Egypt

Finishing using TiO2-nanosol treatment of cellulose acetate (CA) fabrics before and after the latter were pretreated with H2O2was undertaken with a view to im.art unique properties to CA fabrics, notably, self-cleaning. Finishing was performed as per the pad-dry-cure method. The finishing treatment involved dispersing the nano-sized TiO2particles in a mixture of water and ethylene glycol (1:1) and application of the dispersions to CA fabrics was made under a variety of conditions. Self cleaning ability of the fabrics is favored by 1) increasing the concentration of TiO2-nanosol to certain limit;2) prolongation of curing time up to 15 second;3) raising the microwave power from 80% to 100% but with the certainty that power of 90% is the most proper. Besides, exposure time-to UV radiation-up to 90 minutes is essential to have remarkable self cleaning properties while keeping other technical properties, namely, strength, roughness and wettability practically unaltered. Incorporation of binder in the finishing pad-bath helps stabilizing the deposition of TiO2 with excellent self-cleaning. Pretreatment of CA fabrics with H2O2 is a pre requisite to guarantee excellent self-cleaning ability. Thermofixation and microwave fixation produces fabrics with very com.arable technical properties.

关键词： Self-Cleaning Cellulose Acetate microwave Thermofixation Tio2-Nano Particles

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Boundary Layer Development on a Concave Surface： Flow Visualization and Hot Wire Velocity m.asurements

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Journal of Energy and Power Engineering 2014年第7期8卷 1177-1182页

作者： Farouk Hachem mahmoud Khaled mohamad ramadan Charbel Habchi ETF (Energy and Thermo-Fluids) Group School of Engineering L1U (Lebanese International University) Beirut 146404 Lebanon

Gortler vortices are key issues in the design of gas turbine blades. The present study deals with flow visualization over concave surface for gas turbine applications. The aim is to comprehend qualitatively the flow trends, particularly the Gortler vortices formation and development. Gortler vortices have the shape of mushroom-like vortices regularly spaced at 25 mm. These vortices grow and increase in strength more rapidly along the surface in the case of the same grid of turbulence applied to the m.asuring section. The curvature radius of the studied blade is 0.5 m.and the stream turbulence intensity level is 2.6%. The velocity field is m.asured by hot wire anemometer in the streamwise direction. The velocity profile is found to be highly distorted by the momentum transfer associated with Gortler vortices. The results are com.ared to Blasius flow and to literature data for a blade with curvature radius equal to 2 m.

关键词： Gortler vortices concave surface flow visualization velocity profile gas turbine.

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PNPLA3 and TNF-α G238A Genetic Polymorphisms in Egyptian Patients with Different Grades of Severity of NAFLD

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Open Journal of Gastroenterology 2016年第3期6卷 53-64页

作者： mona A. Hegazy Rasha m. Abdel Samie Ahmed Ezzat Nagwa ramadan Laila A. Rashed Abeer m. ElSayed Internal medicine Department Cairo University Cairo Egypt medical Biochemistry Department Cairo University Cairo Egypt Pathology Department National Cancer Institute Cairo University Cairo Egypt

Introduction: There is growing evidence that genetic and environmental factors play an important role in the development and progression of non-alcoholic fatty liver disease (NAFLD). We investigated the association of single nucleotide polymorphism (SNP) rs738409 in PNPLA3 gene and TNF-α G238A polymorphism with the development and severity of NAFLD in an overweight and obese Egyptian population. material and methods: 100 overweight and obese patients with NAFLD and 30 control subjects were enrolled. All NAFLD patients underwent a confirmatory biopsy. Laboratory investigations included fasting plasma glucose, kidney and liver function tests, liver enzymes, lipid profile and hepatitis markers. Abdominal ultrasound was performed and all subjects were genotyped for (rs738409) PNPLA3 and (rs361525) TNF-α gene polymorphisms using polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP). Results: The homozygous GG genotype of the PNPLA3 was most frequent among patients with NASH (26%) as com.ared to borderline NASH (20.5%) and simple steatosis (20%). Higher serum levels of transaminases were observed in NAFLD patients and controls who were carriers of the G allele of rs738409, but this was not statistically significant. Regarding the TNF-α G238A SNP;the frequency of the A allele was significantly higher in NAFLD patients (20%) com.ared to controls (5%) (p value = 0.006). The highest TNF G allele frequency was observed in the NASH group (88%) and this was statistically significant (p value = 0.009). Conclusion: Our study confirmed the association of the PNPLA3 (rs738409) and TNF-α promoter region G238A polymorphisms with susceptibility to NAFLD and its progression.

关键词： NAFLD PNPLA3 TNF-α Polymorphism NASH

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The Prevalence of Human Papilloma Virus (HPV) among Egyptian Women and Its Im.act: An Observational Study

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Open Journal of Obstetrics and Gynecology 2021年第7期11卷 879-884页

作者： m. Elazab O. Ali m. C. ramadan m. Hassan H. Aljedaani F. Gardner Al Galaa Teaching Hospital Cairo Egypt North Cumbria University Hospital North Cumbria UK New Cairo General Hospital Cairo Egypt Ibn Sina College Hospital for medical Science Jeddah KSA DFFP MRCOG Portsmouth Hospital Portsmouth UK

Cancer is one of the most prevalent causes of mortality worldwide. In the cervix, it is confirmed to be caused by different high-risk human papillomavirus (HPV) types. Although many studies have already been conducted worldwide on the epidemiology of HPV infection and their oncogenic properties, limited data are available on HPV prevalence, incidence and its im.acts in Egypt.

关键词： HPV Screening Test Cancer Cervix

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