Fractographic Analysis of Tensile Failures of Zirconia Epoxy Nanocomposites

هذا العمل يصف ملامح سطح الكسر لمادة للايبوكسي النقي وللمتراكب النانوي للايبوكسي زروكونيوم. تم اخضاع جميع العينات لاختبار الشد لتحديد قوة الشد ومعامل الشد. تم استخدام صور المجهر الماسح الالكتروني SEM لدراسة تركيب سطح الكسر لكل العينات. تمت دراسة تركيب سطح الكسر لمادة للايبوكسي النقي وللمتراكب النانوي للايبوكسي زروكونيوم باستخدام برنامج تحليل الصور  (j-images) لتحديد تأثير الجسيمات ZrO2 النانوية على أداء الشد وآلية الفشل للمتراكب النانوي للايبوكسي الزركونيوم. نتائج اختبار الشد تبين أن إضافة الجسيمات النانوية ZrO2 (بنسب 2 و 4 و 6 و 8  و 10 % نسب حجمية ) إلى مصفوفة الايبوكسي يؤدي إلى زيادات في قوة الشد بنسبة 40% ومعامل الشد يتضاعف 200% للنسبة 4% من اضافة الجسيمات الناوية للمتراكب النانوي للايبوكسي زروكونيوم. صور SEM تبين أن أنماط السطوح المكسورة للمتراكب النانوي للايبوكسي زروكونيوم مختلفة عن نمط الايبوكسي النقي. حيث ان خشونة سطح الكسر للمتراكب النانوي للايبوكسي زروكونيوم تزداد مع زيادة في النسب المئوية للجسيمات النانوية ZrO2.This work characterizes the fractographic features of the neat epoxy and ZrO2 epoxy nanocomposites. All samples were subjected to a tensile test to determine the tensile strength and tensile modulus. SEM images were used to study the morphology of the fractured surface. The fractographic of the fracture surfaces were studied by microstructure analysis program (j-images) to specify the effect of ZrO2 nanoparticles on tensile performance and failure mechanism for ZrO2 epoxy nanocomposites. The tensile test results show that the addition of ZrO2 nanoparticles (2, 4, 6, 8, and 10 vol.%) to the epoxy matrix leads to increase the tensile strength about 40% for optimal content of ZrO2 nanoparticles at 4 vol.%, tensile modules of ZrO2 epoxy nanocomposites increased about 200% for optimal content of ZrO2 nanoparticles at 4 vol.%. SEM images show that the patterns of fractured surfaces of ZrO2 epoxy nanocomposites are different from the pattern of the neat epoxy. The fracture roughness of ZrO2 epoxy nanocomposites increased with the increases of the percentages of ZrO2 nanoparticles, where the increment of fracture roughness about 30% for optimal content of ZrO2 nanoparticles at 4 vol.% can be indicator for the improvement of mechanical properties (tensile strength and modules)

Dermatology for the Practicing Allergist: Tinea Pedis and Its Complications

Tinea pedis is a chronic fungal infection of the feet, very often observed in patients who are immuno-suppressed or have diabetes mellitus. The practicing allergist may be called upon to treat this disease for various reasons. Sometimes tinea infection may be mistaken for atopic dermatitis or allergic eczema. In other patients, tinea pedis may complicate allergy and asthma and may contribute to refractory atopic disease. Patients with recurrent cellulitis may be referred to the allergist/immunologist for an immune evaluation and discovered to have tinea pedis as a predisposing factor. From a molecular standpoint, superficial fungal infections may induce a type2 T helper cell response (Th2) that can aggravate atopy. Th2 cytokines may induce eosinophil recruitment and immunoglobulin E (IgE) class switching by B cells, thereby leading to exacerbation of atopic conditions. Three groups of fungal pathogens, referred to as dermatophytes, have been shown to cause tinea pedis: Trychophyton sp, Epidermophyton sp, and Microsporum sp. The disease manifests as a pruritic, erythematous, scaly eruption on the foot and depending on its location, three variants have been described: interdigital type, moccasin type, and vesiculobullous type. Tinea pedis may be associated with recurrent cellulitis, as the fungal pathogens provide a portal for bacterial invasion of subcutaneous tissues. In some cases of refractory asthma, treatment of the associated tinea pedis infection may induce remission in airway disease. Very often, protracted topical and/or oral antifungal agents are required to treat this often frustrating and morbid disease. An evaluation for underlying immuno-suppression or diabetes may be indicated in patients with refractory disease

Pile Setup in Cohesive Soil. I: Experimental Investigation

Pile setup in cohesive soils has been a known phenomenon for several decades. However, a systematic field investigation to provide the needed data to develop analytical procedures and integrate pile setup into the design method rarely exists. This paper summarizes a recently completed field investigation on five fully instrumented steel H-piles embedded in cohesive soils, while a companion paper discusses the development of the pile setup method. During the field investigation, detailed soil characterization, monitoring of soil total lateral stress and pore-water pressure, collection of pile dynamic restrike data as a function of time, and vertical static load tests were completed. Restrike measurements confirm that pile setup occurs at a logarithmic rate following the end of driving, and its development correlates well with the rate of dissipation of the measured porewater pressure. Based on the field data collected, it was concluded that the skin friction component, not the end bearing, contributes predominantly to the setup, which can be accurately estimated for practical purposes using soil properties, such as coefficient of consolidation, undrained shear strength, and the standard penetration testN-value

Empathic accuracy and aggression in couples: Individual and dyadic links

This study examined links between intimate partner aggression and empathic accuracy – how accurately partners can read one another’s emotions – during highly affective moments from couples’ (N = 109) video recall of laboratory-based discussions of upsetting events. Less empathic accuracy between partners was generally related to higher levels of aggression by both partners. More specific patterns emerged based on the type of aggression and emotion being expressed. Women’s poorer ability to read their partners’ vulnerable and positive emotions was linked to both men’s and women’s greater physical and psychological aggression. Moreover, women’s inaccuracy in reading their partner’s hostility was linked to women’s greater psychological aggression towards the men. Men’s inaccuracy in reading their partner’s hostility was linked to women’s (not men’s) greater physical and psychological aggression. Findings suggest important nuances in the links between empathic inaccuracy and aggression, and implications for prevention and treatment of partner aggression are discussed

SIMULATION OF NATURALTY FRACTURED RESERVOIRS WITH SIMBESTII

Simulation of naturally fractured reservoirs is a laborious techniques, because there are two different porous media in which fluids exist and flow. The porous media exhibit wide variations in their physical properties. The matrix usually represents the major storage capacity while the fractures system provides the main paths of the flowing fluids. Several simulators have been constructed by specialist companies. One is the SimBestII, which is the product of Scientific Software- Intercomp. In order to simulate a reservoir properly by such simulator, one should have an idea about the equations and the procedures encountered in it. In the present study, an attempt has been made to understand the general structure of SimBestll. The flow equations that are employed in SimBestII are investigated and some of the calculation procedures are clarified. The exchange term in the flow equations is discussed comprehensively and the justifications to reduce or magniff the imbibition rate are explore

Predicting Player Power In Fortnite Using Just Nueral Network

Accurate statistical analysis of Fortnite gameplay data is essential for improving gaming strategies and performance. In this study, we present a novel approach to analyze Fortnite statistics using machine learning techniques. Our dataset comprises a wide range of gameplay metrics, including eliminations, assists, revives, accuracy, hits, headshots, distance traveled, materials gathered, materials used, damage taken, damage to players, damage to structures, and more. We collected this dataset to gain insights into Fortnite player performance and strategies. The proposed model employs advanced machine learning algorithms and data preprocessing techniques. We aim to identify key performance indicators and influential factors that contribute to Fortnite success. By exploring patterns and relationships within the dataset, our model can provide valuable insights into gameplay optimization. Our research involves feature analysis to determine the most influential factors in predicting Fortnite performance. These factors include eliminations, assists, revives, accuracy, hits, headshots, distance traveled, materials gathered, materials used, damage taken, damage to players, damage to structures, and more. By understanding the impact of these factors, we aim to help Fortnite players enhance their skills and strategies. Through extensive training and validation of our machine learning model, we achieved remarkable results, with an accuracy rate of [Your Accuracy Rate]% and an average error of [Your Average Error]. This research not only provides valuable insights into Fortnite gameplay but also offers a foundation for future research in the field of esports analytics and performance optimization

The Hydraulic and Environmental operation for the Main Outfall Drain, Ad Dalmaj Lake and Al Hammar Marsh System

Iraqi Marshlands which are located within the southern part of Iraq were dried after 1991. The dried marshes were re-flooded after year 2003. Because of the shortage of water that feeds the marshes during the last years, these marshes began to dry again. Therefore, finding new feeding sources became very necessary matter. The Main Outfall Drain, MOD, is suggested to be one of these sources to feed Al Hammar Marsh during the dry water years. Ad Dalmaj Lake which is located upstream of Al Hammar Marsh is mainly feeding by the MOD water and then the outfall of this lake is discharge again into the MOD. Therefore, the hydrological operation of this lake and then the quantity and quality of the outflow water from this lake into the MOD affected the water quality of Al Hammar Marsh when using the MOD water to feed the marsh. A hydrological and water quality routing model was prepared based on mass conservation low, mass balance model, and two scenarios were applied for Ad Dalmaj Lake feeding, constant inflow with variable outflow and constant outflow with variable inflow, based on the incoming and outgoing discharges. Each scenario includes six cases of lake maximum inundation area; 100%, 90%, 80%, 70%, 60% and minimum inundation. For each case the inundation area varied with respect to the ET0 variation from minimum area during the month of maximum ET0 to maximum area, of this case, during the month of minimum ET0. TDS concentration was used as a measure of the salinity of the water because it fairly indicates the level of salinity problem. The variation of inflow and outflows discharges, water level, lake and marsh area, storage volume, and the water salinity within the lake and marsh were Results of applying these models with these flow scenarios and inundation cases show that the water salinity within Ad Dalmaj Lake and Al Hammar Marsh was out of the acceptable range of international standards for most of the studied cases. While for other cases it was unpalatable for drinking, several restrictions must be imposed when used for irrigation to prevent salts effects on crops, soil, and ground water, and not acceptable for livestock and unfit for poultry in most of the months during two operation years and in some months in the beginning of the first year, the water can be used for growing livestock and poultry

Side lobe reduction in array antenna by using novel design of EBG

A novel design of EBG is used to replace the mushroom like EBG for surrounding the array patch antenna. In order to improve its radiation performances, Electromagnetic band stop for reducing the surface waves effects is presented. The novel design of Triple Side Slotted EBG (TSSEBG) showed an improvement in the antenna efficiency, directivity and gain as compared to the reference antenna without using EBG, due to reduce the surface waves effects which leads to decrease the side lobes. TSSEBG has been introduced by some modifications in conventional mushroom-like EBG structure. Reducing the complexity was achieved by reducing the number of unit cells and vias, in case of used TSSEBG instead of mushroom like EBG. Additionally, the TSSEBG provided triple band gap compared with mushroom like EBG structure which had only one band gap frequency at 6 GHz. The placement of TSSEBG is a flexible structure which provides a good choice in the antenna applications. The simulation results of array patch antenna with and without mushroom like EBG and TSSEBG are arranged in Table 1. This structure has vast applications in satellite communications

Mechanical Properties Comparison of Four Models, Failure Theories Study and Estimation of Thermal Expansion Coefficients for Artificial E-glass Polyester Composite

In this paper, the mechanical properties of artificial E-glass reinforced polyester composite were evaluated; the elastic properties and the strength of the composite were measured experimentally by tensile tests and then compared with the predicted values by theoretical four micromechanical constitutive models. The strength of the composite lamina and laminates were also determined experimentally and compared with five widely used theoretical failure theories. The lamination theory was also used to determine the strength of laminates by applying Hill- Tsai failure criterion. The theoretical models showed that the composite stiffness increases with increasing the fibre volume fraction and the volume fraction which gave the best fit to the experimental results of elastic modulus (E1) corresponds to volume fraction (Vf) equal 0.37. The stiffness of a unidirectional lamina depends on the fiber orientation relative to the off-axis load direction, and it drops sharply as the fiber alignment angle increases. In addition, the prediction of thermal expansion coefficients of composite is carried out in the present analysis, whereas the values of the coefficient that estimated to be based on the mechanical properties of the certain composite theoretically and experimentally