Effect of Reinforcing by Palms-Carbon Hybrid Fibers on Mechanical Properties of Conbextra Epoxy EP-10 Resin

يهدف هذا البحث الى دراسة تاثير التقوية بنسب مختلفة (20%,40%,60%) من الياف النخيل-الكاربون الهجينة على الخواص الميكانيكية لراتنج الإيبوكسي كونبكسترا EP-10 ,حيث الهدف من دكج هذين النوعين من الألياف في ارضية واحدة هو الحفاظ على الخواص الميكانيكية و خفض تكاليف التصنيع . في هذا البحث تم دراسة مقاومة الصدمة ,مقامة الشد , مقاومة الانثناء , الصلادة للمادة المركبة الناتجة المقواة بالياف هجينة من ألياف النخيل الطبيعية و الياف الكاربون بشكل حصيرة ثانية (0°-90°) و بكثافة ( 1.45g/). حيث تم مزج هذه الالياف في ارضية من راتنج الايبوكسي كونبكسترا و بنسب تقوية مختلفة و دراسة اثر ذلك على الخواص الميكانيكية , اظهرت النتائج تحسن هذه الخواص بعد التقوية بالالياف اضافة الى زيادة قيمة هذه الخواص مع زيادة نسبة التقوية بالالياف اضافة الى ويادة قيمة هذه الخواص مع زيادة نسبة التقوية. فبالنسبة الى مقاومة الصدمة ارتفعت من ( ) و مقاومة الشد من (70MPa) الى (365MPa) و مقاومة الانثناء من (1.162GPa) الى (1.55GPa) و الصلادة من( /8.5 N) الى (80N/  ) و لنسب تقوية 0% و 60% على التوالي. يهدف هذا البحث الى دراسة تاثير التقوية بنسب مختلفة (20%,40%,60%) من الياف النخيل-الكاربون الهجينة على الخواص الميكانيكية لراتنج الإيبوكسي كونبكسترا EP-10 ,حيث الهدف من دكج هذين النوعين من الألياف في ارضية واحدة هو الحفاظ على الخواص الميكانيكية و خفض تكاليف التصنيع . في هذا البحث تم دراسة مقاومة الصدمة ,مقامة الشد , مقاومة الانثناء , الصلادة للمادة المركبة الناتجة المقواة بالياف هجينة من ألياف النخيل الطبيعية و الياف الكاربون بشكل حصيرة ثانية (0°-90°) و بكثافة ( 1.45g/). حيث تم مزج هذه الالياف في ارضية من راتنج الايبوكسي كونبكسترا و بنسب تقوية مختلفة و دراسة اثر ذلك على الخواص الميكانيكية , اظهرت النتائج تحسن هذه الخواص بعد التقوية بالالياف اضافة الى زيادة قيمة هذه الخواص مع زيادة نسبة التقوية بالالياف اضافة الى ويادة قيمة هذه الخواص مع زيادة نسبة التقوية. فبالنسبة الى مقاومة الصدمة ارتفعت من ( ) و مقاومة الشد من (70MPa) الى (365MPa) و مقاومة الانثناء من (1.162GPa) الى (1.55GPa) و الصلادة من( /8.5 N) الى (80N/  ) و لنسب تقوية 0% و 60% على التوالي.The objective of this research is to study the effect of reinforcing with different percentage (20%, 40%, and 60%) of hybrid palms-carbon fibers on mechanical properties of conbextra epoxy EP-10 resin. The aim from this incorporation of both fibers into a single matrix will stabilize mechanical properties and lowering manufacturing costs. In this research the impact strength, tensile strength, flexural strength, and hardness were studied for composite material reinforced with hybrid fibers for palms and carbon as a woven roving (0°-90°) with density (1.45g/m3). These fibers were mixed with conbextra epoxy EP-10 resin in different reinforcement percentage and studied these effects on the mechanical properties of conbextra epoxy EP-10 resin. It has shown an improvement in these mechanical properties after reinforcement by fibers where the value of mechanical properties will increase with increasing percentage of reinforcement. Impact strength increased from (23Kj/m2) to (170Kj/m2), and tensile strength from(70MPa) to (365MPa), and flexural strength from(0.162GPa) to (1.55GPa), and hardness from(8.5N/m2) to (80N/m2) for reinforcing percentages 0% and 60% respectively

Marfan syndrome diagnosis and management

Marfan syndrome is the most common inherited multisystem disorder of connective tissue. This autosomal dominant condition has an incidence of 2-3 per 10,000 individuals. Although genetic diagnostic techniques are available, the diagnosis is primarily made using the Ghent diagnostic criteria. Early identification and appropriate management improves the prognosis of patients with Marfan syndrome who are prone to the life-threatening cardiovascular complications of aortic dissection and rupture. Beta-blockers have been demonstrated to slow aortic growth and thus delay the time to aortic surgery. Operative intervention has markedly changed the prognosis of patients with Marfan syndrome and can be safely performed on an elective basis. The advance in the understanding of the cause of Marfan syndrome, as well as early recognition of the disorder and subsequent institution of medical and surgical therapy has resulted in dramatic improvement

Analisa dan Perancangan Website Media Sosial Untuk Komunitas Tari Dengan Metode Prototyping

Informasi adalah sesuatu yang selalu dibutuhkan ketika setiap pengguna internet melakukan browsing. Informasi tersebut bisa berupa artikel, musik, foto, dan juga video. Dalam dunia tari, informasi sangat mempunyai pengaruh yang besar dalam berkembangnya setiap penari. Website adalah salah satu cara penari untuk mendapatkan informasi berupa konten video atau artikel yang dapat mereka akses dan digunakan untuk bertukar informasi dengan penari yang lain baik lokal atau internasional. Dengan adanya website yang mempunyai ruang lingkup lebih spesifik akan membantu untuk penari tersebut lebih efisien dalam saling bertukar informasi. Website dengan berbasis media sosial akan sangat membantu dalam melakukan komunikasi kepada setiap pengguna di dalamnya. Dalam penilitian ini akan menggunakan metode prototyping, supaya website yang dibuat akan lebih user friendly karena perancangan website akan melibatkan calon pengguna dalam menentukan desain dan fitur yang akan digunakan

Nonlinear Finite Element Analysis of Reinforced Concrete Arched Beams with Normal and High Compressive Strength

This study describes a three-dimensional nonlinear finite element model suitable for the analysis of high strength reinforced concrete arched beams under static load. The twenty node isoperimetric brick element has been used to model the concrete and reinforcing steel bars have been idealized as axial members embedded within the brick elements. Perfect bond was assumed to occur between the concrete and the reinforcing bars. The behavior of concrete in compression is simulated by an elasto-plastic work hardening model followed by a perfectly plastic response, which is terminated at the onset of the crushing. In tension, a smeared crack model with fixed orthogonal cracks has been used. High and normal strength reinforced concrete arched beams have been analyzed in the present study. Parametric studies have been carried out to investigate the effect of radius to span length ratio, boundary conditions, (α2) [the sudden loss of stress at the instant of cracking], and effect of compressive strength. In general good agreement between the finite element solutions and the experimental results have been obtained

Effect of Fibers Orientation on the Nonlinear Dynamic Performance of Laminated Composite Plate under Different Loading In-plane

Non-linear dynamic analysis of a cross-ply laminated composite with fibre spacing plates under in-plane loading was presented. The mathematical formulation is based on first-order shear deformation theory and von-Karman non-linearity. Eight-node isoperimetric quadrilateral elements with five degrees of freedom per node were used to maintain geometric nonlinearity. In this investigation, a variety of fiber spacings and fibre orientations were used for the purpose of studying the effect of improvements on the behaviour of samples with this type of load. The dynamic equilibrium equations were solved using the Newmark integration technique. The non-linear dynamic analysis addressed several functions of changing fibre spacing with various changes in volume percentage and diverse fibre orientations. Fibre orientation, volume fraction fluctuation, and fibre distribution significantly affected laminated composite plates' non-linear dynamic behaviour. This study showed that the combination of improvements does not give a clear vision of the ideal improvement, and the best case for fibre distribution and the best case for layer rotation and combination should be studied to know the effect of the ameliorations one on the other and distinguish the impact of the transverse loading pattern in one direction on rotating the sample layers with axial load in one direction, so that changing the fibre distribution is more effective in the behaviour and stability of the plate by taking advantage of the orientation change, as demonstrated in this paper. Doi: 10.28991/CEJ-2022-08-12-03 Full Text: PD

Left atrial appendage thrombus is not uncommon in patients with acute atrial fibrillation and a recent embolic event: A transesophageal echocardiographics tudy

AbstractObjectives. The objective of this study was to determine the frequency of left atrial thrombus in patients with acute atrial fibrillation.Background. It is commonly assumed but unproved that left atrial thrombus in patients with atrial fibrillation begins to form after the onset of atrial fibrillation and that it requires ≥3 days to form. Thus, patients with acute atrial fibrillation (i.e., <3 days) frequently undergo cardioversion without anticoagulation prophylaxis.Methods. Three hundred seventeen patients (250 men, 67 women; mean [±SD] age 64 ± 12 years) with acute (n = 143) or chronic (n = 174) atrial fibrillation were studied by two-dimensional transesophageal echocardiography.Results. Left atrial appendage thrombus was present in 20 patients (14%) with acute and 47 patients (27%, p < 0.01) with chronic atrial fibrillation. In patients with a recent embolic event, the frequency of left atrial appendage thrombus did not differ between those with acute (5 [21%] of 24) and those with chronic (12 [23%] of 52, p = NS) atrial fibrillation. Patients with acute versus chronic atrial fibrillation, respectively, did not differ (p = NS) in mean age (64 ± 13 vs. 65 ± 11 years), frequency of concentric left ventricular hypertrophy (32% vs. 26%), hypertension (32% vs. 41%), coronary artery disease (35% vs. 39%), congestive heart failure (43% vs. 48%), mitral stenosis (4% vs. 7%) or mitral valve replacement (1.4% vs. 6%). The minimally detectable difference in proportions between patients with acute and chronic atrial fibrillation based on a power of 0.80 and base proportion of 0.20 was 14%.Conclusions. Left atrial thrombus does occur in patients with acute atrial fibrillation <3 days in duration. The frequency of left atrial thrombus in patients with recent emboli is comparable between those with acute and chronic atrial fibrillation. These data suggest that patients with acute atrial fibrillation for <3 days require anticoagulation prophylaxis or evaluation by transesophageal echocardiography before cardioversion and should not be assumed to be free of left atrial thrombus

Flammability action of tires material after adding flame inhibitor

Magnesium hydroxide was used as flame inhibitor to increased flame resistance for tires .Magnesium hydroxide was adding with (5%,10%) weight percents to rubber master batch of tire and then exposed the resulting material to a flame generated from gas torch with (10 mm) exposure distance . Method of measuring the surface temperature opposite to the flame was used to determine the heat transferred through tire material. The results were obtained shows enhanced flame resistance for tire by added magnesium hydroxide and this resistance increased by increasing hydroxide Percentage

A Challenging Combination: Anomalous Left Anterior Descending Coronary Artery, Myocardial Bridging, and Endothelial Dysfunction

50 years old female patient with a medical history of hypertension presented to the clinic with chest pain, palpitations, and dyspnea on exertion of 2 years duration. Extensive workup in search of the culprit etiology of her chest pain revealed a challenging combination of an anomalous left anterior descending artery with myocardial bridging and endothelial dysfunction. She was treated medically with long acting nitrates, L-arginine and calcium channel blockers, and remains asymptomatic after 12 months of follow up

The Role of Elementary School Principals inside the Green Line in Compromising Students with Attention Deficit Hyperactivity Disorder and its Relationship to their Personal Traits from the Teachers’ Point of View دور مديري المدارس الابتدائية داخل الخط الأخضر في دمج الطلبة ذوي اضطراب نقص الانتباه المصحوب بفرط الحركة وعلاقته بسماتهم الشخصية

Abstract: The study aimed to identify the role of elementary school principals within the green line in integrating students with ADHD and its relationship to their personal traits from the teachers’ point of view. The correlational descriptive methodology was used, and the questionnaire represented the tool of the study. The study sample consisted of (409) teachers, divided into (228) males and (181) females, who were randomly selected from elementary schools within the Green Line. The results showed that the level of the overall role of elementary school principals within the green line in compromising students with ADHD was high, and that the overall level of personal traits among the affected students was medium, and the existence of a positive correlation between the role of elementary school principals within the green line in compromising students with ADHD and their personal traits. ملخص: هدفت الدراسة تعرف دور مديري المدارس الابتدائية داخل الخط الأخضر في دمج الطلبة ذوي اضطراب نقص الانتباه المصحوب بفرط الحركة وعلاقته بسماتهم الشخصية. استخدمت الدراسة المنهج الوصفي الارتباطي واستخدمت الاستبانة أداة للدراسة، وتكونت عينة الدراسة من (409) معلماً ومعلمة يتوزعون إلى (228) معلماً و(181) معلمة تم اختيارهم بالطريقة الطبقية العشوائية. أظهرت النتائج أن مستوى دور مديري المدارس الابتدائية داخل الخط الأخضر في دمج الطلبة ذوي اضطراب نقص الانتباه المصحوب بفرط الحركة ككل جاء بدرجة بمستوى كبير، وأن المستوى الكلي للسمات الشخصية لدى الطلبة ذوي اضطراب نقص الانتباه المصحوب بفرط الحركة جاء متوسطاً، ووجود علاقة ارتباطية موجبة بين دور مديري المدارس الابتدائية داخل الخط الأخضر في دمج الطلبة ذوي اضطراب نقص الانتباه المصحوب بفرط الحركة وسماتهم الشخصية