1,259 research outputs found
Flight simulator for hypersonic vehicle and a study of NASP handling qualities
The research goal of the Human-Machine Systems Engineering Group was to study the existing handling quality studies in aircraft with sonic to supersonic speeds and power in order to understand information requirements needed for a hypersonic vehicle flight simulator. This goal falls within the NASA task statements: (1) develop flight simulator for hypersonic vehicle; (2) study NASP handling qualities; and (3) study effects of flexibility on handling qualities and on control system performance. Following the above statement of work, the group has developed three research strategies. These are: (1) to study existing handling quality studies and the associated aircraft and develop flight simulation data characterization; (2) to develop a profile for flight simulation data acquisition based on objective statement no. 1 above; and (3) to develop a simulator and an embedded expert system platform which can be used in handling quality experiments for hypersonic aircraft/flight simulation training
A study of the reactions between halamines and varieties of phosphorus species
In this work the oxidation of various low-valent phosphorus species with halomines and halogens has been studied. (^31)P nuclear magnetic resonance spectroscopy has been used to follow the reactions, and the pairwise additivity rule has been tested to determine if it is possible to predict the chemical shifts of the new species prepared. The reaction of Me(_2)NX (X = C1 or Br) with a number of phosphorus(III)species produced the phosphonium salt of the corresponding halide by simple amination at the phosphorus atom. This reaction occurred for(Me(_2)N)(_n)PX((_3-n)), (X = F, C1, Br and n = 1, 2) except for Me(_2)NPF(_2); for Ph(_n)PR((_3-n)) (R = Me, C(_6)H(_11), Me(_2)N, and n = 0-3) except for (Me(_2)N)(_3)P; and for the species Me(_2)PC1, MePC1(_2), (C(_6)H(_11))(_2)PC1 and Bu(^n)(_3)P. The fluorine containing phosphorus species studied, where there was more than one fluorine on the phosphorus (PF(_3) and Me(_2)NPF(_2)), gave more complex reactions which probably occurred due to rearrangement of the intially formed phosphorus(V) species. The overall stoichiometery of one such reaction was found to be: 2Me(_2)NPF(_2) + 3Me(_2)NBr = [(Me(_2)N)(_3)PF]Br + (Me(_2)N)(_2)PF(_3) + Br(_2) In the case of (Me(_2)N)(_3)P halogenation was found to occur with formation of tetramethylhydrazene. Reaction of dimethylchloramine and dimethyl bromamine with phosphorus(III) species containing the MeO group ((MeO)(_n)PX((_3-n), X -= C1 or Ph and n = 1-3) may well have formed a phosphonium salt but the observed products were the halomethane and a phosphorus(V) species contain a P=0 bond, e.g. (MeO)(_3)P + Me(_2)NBr = Me(_2)NPO(OMe)(_2) + MeBr. In the case of the aryl and thioesters studied ((MeS)(_3)P and (PhO)(_3)P) the intermediate species are observed
Comparison of Plasma Concentrations for Some Biological Markers in Patients with Type 2 Diabetes Before and After Consuming a Vegetarian Diet
Background: The prevalence of diabetes mellitus has been increasing worldwide in recent years. Long-term diabetes results in vascular changes and dysfunction. Complications of diabetes are the major causes of morbidity and mortality in diabetic patients. [1] Renal involvement is an important complication of diabetes mellitus. End-stage kidney with renal failure accounts for deaths in more than 10% of all diabetics. [2] Diet therapy is fundamentally important for both diabetes and diabetic kidney disease (DKD) to maintain glucose control and suppress the progression of renal damage.[3] The main nutrition-related goals for people with chronic kidney disease (CKD) involve the slowing of kidney failure progression rate and minimizing uremic toxicity and metabolic disorders of kidney failure, diminishing proteinuria, maintaining good nutritional status, and lowering the risk of secondary complications including cardiovascular disease, bone disease, and disturbed blood pressure control [4]. The aim of our study was to compare some biological markers in patients with type 2 diabetes whom are at risk of developing kidney failure, before and after starting a vegetarian diet for at least 30 days. Materials & Methods: In this study we measured plasma concentrations of Urea, Creatinine, Fasting Glucose, and calculated EGFR according to Cockcroft-Gault equation for of 20 patients with type 2 diabetes (5 males, 15 females), with an average age of 63 years. Blood-sampling and testing was conducted in two time periods. The first one was at the regular diet for subjects consuming all kind of foods including proteins of animal and plant sources, the second one was after at least 30 days of fasting involves abstention from all animal products (Easter Fasting). Results: Plasma Urea was significantly lower after the diet (mean ± SD: 27 ± 11 mg/dl) than before diet (mean ± SD: 42 ± 23.55 mg/dl). Using student’s t-test P was: 0.001 ˂ 0.05. Plasma Creatinine was significantly lower after the diet (mean ± SD: 1.09 ± 0.25 mg/dl) than before diet (mean ± SD: 1.2 ± 0.3 mg/dl). Using student’s t-test P was: 0.022 ˂ 0.05. Plasma Glucose was lower after the diet (mean ± SD: 126 ± 52.15 mg/dl) than before diet (mean ± SD: 140 ± 67.44 mg/dl). Using student’s t-test P was: 0.108 ˃ 0.05. EGFR was higher after the diet (mean ± SD: 71.45 ± 26.2 ml/min) than before diet (mean ± SD: 69.45 ± 25.54 ml/min). Using student’s t-test P was: 0.039 ˂ 0.05. Conclusion: These results may indicate that the vegetarian diet could be a kidney protective for patients with type 2 diabetes. DOI: 10.7176/CMR/11-6-04 Publication date: August 31st 201
Antibacterial Activity of Syrian Capparis spinosa. (Capparidaceae) Fruits and Roots
The ethanolic extract of Capparis Spinosa. Roots and Fruits were tested for their antibacterial activity against four species of bacteria, Bacillus subtilis, Escherichia coli, Klebsiella sp.and Staphylococcus aureus using disc diffusion technique. The extract concentrations of ethanolic roots and fruits extracts used were 0 (control), 125, 250, 500 and 1000 ppm in triplicates along with standard antibiotic, Ciprofloxacine (5 μg), Gentamycine (10 μg). Comparatively, ethanolic roots extracts showed higher activity than ethanolic fruits extracts. The results showed that In 1000 ppm ethanolic roots extract, a maximum of 3.2 cm ZI was observed against Staphylococcus aureus followed by 2.3 cm against Escherichia coli. The maximum ZI of 2.1 cm was recorded in 1000 ppm ethanolic extract of fruits against Pseudomonas aeruginosa followed by 1.5 cm against Bacillus subtilis. DOI: 10.7176/JBAH/9-18-02 Publication date:September 30th 201
Reconstruction of Anterior Table Frontal Sinus Defects with Pericranial Flap and Titanium Mesh
A certain class of analytic functions of complex order connected with a q-analogue of integral operators
The establishment of the Egyptian geographic network EGN : review the development phases, lesson learned and the impact on the GIS industry in Egypt
Isolation and antibiotic susceptibility of Salmonella and Shigella strains isolated from children in Gaza, Palestine from 1999 to 2006
Background and Aim: Diarrhea and acute gastroenteritis are among the leading causes of illnesses and death in infants and children throughout the world, especially in developing countries, Globally, Salmonella and Shigella remain the major contributors to acute enteric infections and diarrhea.
Methods: In the present study, Shigella‐ and Salmonella‐related diarrhea was studied among 3570 children in Gaza, Palestine from January 1999 to September 2006 to determine the prevalence and the antimicrobial susceptibility of the isolates.
Results: The frequency of isolation was 1.8% (65/3570) for Salmonella spp. and 0.8% (28/3570) for Shigella spp. Shigella flexneri (16/28) was the most frequently isolated Shigella species. Most of the Shigella isolates were resistant to trimethoprim‐sulfamethoxazole (89%), ampicillin (79%) and chloramphenicol (46%) and most of the Salmonella isolates showed resistance
Chicken Quantitative Trait lLoci for Growth and Body Composition Associated with the Very Low Density Apolipoprotein-II Gene
Very low density apolipoprotein-II (apoVLDL-II) is a major constituent of very low density lipoprotein and is involved in lipid transportation in chickens. The current study was designed to investigate the associations of an apoVLDL-II gene polymorphism on chicken growth and body composition traits. The Iowa Growth and Composition Resource Population was established by crossing broiler sires with dams from 2 unrelated highly inbred lines (Leghorn and Fayoumi). The F1 birds were intercrossed, within dam line, to produce 2 related F2 populations. Body weight and body composition traits were measured in the F2 population. Primers for the 5\u27-flanking region in apoVLDL-II were designed from database chicken genomic sequence. Single nucleotide polymorphisms (SNP) between parental lines were detected by DNA sequencing, and PCR-RFLP methods were then developed to genotype SNP in the F2 population. There was no polymorphism in the 492 bp sequenced between broiler and Leghorn. The apoVLDL-II polymorphism between broiler and Fayoumi was associated with multiple traits of growth and body composition in the 148 male F2 individuals, including BW, breast muscle weight, drumstick weight, and tibia length. This research suggests that apoVLDL-II or a tightly linked gene has broad effects on growth and development in the chicken
The Effectiveness of a Developed Unit based on the Educational Scaffolding Strategy in Improving Visual Thinking Skills and Solving Mathematical Problems among Fourth Grade Female Students in Palestine
ملخص: هدفت الدراسة التعرف على فاعلية وحدة مطورة وفقاً لإستراتيجية السقالات التعليمية في تحسين مهارات التفكير البصري وحل المسائل الرياضية لدى طالبات الصف الرابع الأساسي في فلسطين، وتم استخدام التصميم شبه التجريبي، وتمثلت أدوات الدراسة باختباري التفكير البصري وحل المسائل الرياضية في الهندسة، وتكونت عينة الدراسة من (82) طالبةمن طالبات الصف الرابع الأساسي، قسمت إلى مجموعتين: تجريبية وضابطة، قوام كلٍ منهما (41) طالبةً، حيث تعلمت طالبات المجموعة التجريبية مادة الهندسة باستخدام إستراتيجية السقالات التعليمية، أما طالبات المجموعة الضابطة فقد تعلمن بالطريقة العادية. وأبرزت نتائج الدراسة وجود فروق ذات دلالة إحصائية بين المجموعتين التجريبية والضابطة في القياس البعدي في اختبار مهارات التفكير البصري، وكذلك اختبار حل المسائل الرياضية لصالح طالبات المجموعة التجريبية، اللاتي استخدمن إستراتيجية السقالات التعليمية في مادة الهندسة،وأظهرت النتائج فاعليةِ إستراتيجية السقالات التعليمية في تنمية مهارتي التفكير البصري وحل المسائل الرياضية، ووجود تأثيرٍ كبيرٍ لإستراتيجية السقالات التعليمية في تنمية هاتيّن المهارتيّن لدى الطالبات في وحدة الهندسة والقياس. وأوصت الدراسة بضرورة تنفيذ ورش العمل والدورات لمعلمي الرياضيات وفقاً لإستراتيجية السقالات التعليمية، وتصميم دليل لبيان خطواتها، وتشجيع الطلبة على ممارسة التفكير البصري وحل المسائل الرياضية.Abstract: The current study aimed to identify the effectiveness of a developed unit based on the educational scaffolding strategy (EDS) in improving visual thinking skills (VTS) and solving the mathematical problem (SMP) for the fourth-grade female students in Palestine. A quasi-experimental design was used. The tools include a (VTS) test, and an (SMP) test in geometry and measurement. The sample consisted of (82) fourth grade female students divided into two equal groups. The experimental group was taught geometry using the (EDS), while the control group was taught via the normal method. The results of the study showed that there was a statistically significant difference, between control group and experimental group for the benefit of the experimental group in VTS and SMP. Also, the findings indicated the effectiveness of the (EDS) in improving both (VTS) and (SMP). Additionally, the study recommended the necessity of implementing workshops and courses for mathematics teachers according to the (EDS), designing a guide to show its steps, and encouraging students to practice (VTS) and (SMP)
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