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The modeling of both the synchronous generator and induction motor which is represented by the rotor reference frame was studied where the modeling was established using MATLAB /SIMULINK software package for an isolated synchronous generator direct-on-line with different sized induction motors; 20, 50, and 100 Hp, at manually adjusted excitation voltage values which were maintained constant at 3.35, 4.55, and 6.21 V, respectively. The purpose of this work is to study the impact of a sudden increase in the load torque; from 0 to 150 % with an increase of 25 %, of full load torque was studied at a constant motor speed of 188.49 rad sec-1. On the other hand, the impact of a sudden decrease in the rotor speed by about 20 % from its rated value; from 188.49 to 150.79 rad sec-1 was also studied at full load torque of the same different-sized induction motors. These values were manually recorded and response variables of the generator including terminal voltage, current, output power, electromagnetic torque, and load angle were determined and represented as a function of time. The results illustrated the Changes in the terminal voltage, the current, the output power, the electromagnetic torque, and the load angle as parameters of a synchronous generator for different-sized induction motors.

development of cytomegalovirus (CMV)-specific CD8+ T cell response is crucial in preventing symptomatic CMV infection specially, in stem cell transplant (SCT) patients. The aim of this study was to evaluate CMV-specific CD8+ T cell reconstitution in allogeneic SCT recipients and to study the possible association between CMV-specific CD8+ T cell recovery with protection from CMV reactivation and persistency.Human leuKocyte antigen (HLA)-tetramers were used for CMV-specific CD8+ cell quantitation by Flow cytometry in twenty post-allogeneic SCT patients.Nine patients (45%) developed rapid recovery of CMV-specific CD8+ cells, among them; 7 patients (78%) had no CMV reactivation in the first 95 days post-transplant. Five patients had developed persistent CMV viremia; all of them had not developed CMV-specific CD8+ recovery till day 95 post-transplant. Patients with persistent CMV viremia had a statistically significant lower means of CMV-specific CD8+ percent and absolute count compared to those without persistent viremia (p = .001, .015), respectively.The incidence of CMV reactivation and persistency was higher among patients with delayed CMV-specific CD8+ reconstitution in the first 95 days post-transplant.CMV-specific CD8+ cells can help in categorizing patients into risk groups: (early recovery/low risk) and (delayed recovery/increased risk), this tool may guide clinicians in the selection of patients who may profit from prophylactic antiviral therapy and frequent viral monitoring.

Background Cefpodoxime is a broad spectrum third generation cephalosporin with antibacterial activity similar to parenteral cephalosporins. Active against Gram-negative and -positive bacteria, empirical treatment with cefpodoxime is recommended for a wide range of community-acquired infections. We assessed the efficacy of cefpodoxime for the treatment of upper respiratory tract infections (URTI) in Egyptian adults, and evaluated its safety in daily practice. Methods This prospective, observational, multicentre study recruited adult patients, presenting with acute maxillary sinusitis and tonsilopharyngitis, prescribed 200 mg/day cefpodoxime for 5–10 days by their physicians decision. Effectiveness, defined as the proportion of patients exhibiting a complete recovery of clinical symptoms for acute sinusitis and tonsilopharyngitis, was assessed. Safety was evaluated by measuring the prevalence and severity of adverse events (AEs). Results A total of 1425 adult patients were recruited from 134 centers across Egypt. Significant reductions in URTI-related signs and symptoms were observed in subjects prescribed cefpodoxime for a mean 5.87 ± 1.73 days. An 83.3% cure rate and a 16.2% improvement rate were noted for both acute maxillary sinusitis and tonsilopharyngitis patients. Superior outcomes were observed in patients with acute tonsilopharyngitis compared to the acute maxillary sinusitis cohort (86.3% and 77.4%, respectively; p Conclusions High cure rates for acute maxillary sinusitis and acute tonsilopharyngitis, and a favorable safety and tolerability profile were noted following treatment with cefpodoxime. Thus, cefpodoxime seems to be effective as empirical treatment in adult Egyptian patients with acute UTRIs.

The present study was an attempt to determine the effectiveness of using multi- devices technique to develop students' grammatical ability. Participants were 40 Preparatory Year Treatment students from Qassim Private Colleges in Saudi Arabia. The experimental group (N 20) used multi devices technique for testing grammar; online testing, mobile testing, machine testing (auto test) and pen and paper testing technique whereas the control group (N20) was tested through two exams; midterm and final exams in a paper and a pen format. The pre-post-test comprised two parts, the first part includes multiple-choice questions, the second part includes fill in gaps questions. Results of the t. test analysis revealed that using multi devices technique yielded significant effects on students' grammar, i.e. the experimental group outperformed the control group. . Key words: Multi- devices, Testing grammar, mobile testing, online testing.

This paper addresses the problem of scheduling and load balancing in heterogeneous computational grids. We proposed a two-level load balancing policy for the multi -cluster grid environment where computational resources are dispersed in different adm inistrative domains or clusters which are located in different local area networks. The proposed load balancing policy takes into account the heterogeneity of the computational resources. It distributes the system workload based on the processing elements capacity which leads to minimize the overall job mean response time and maximize the system utilization and throughput at the steady state. To evaluate the performance of the proposed load balancing policy, an analytical model is developed. The results ob tained analytically are validated by simulating the model using Arena simulation package. The results show that the overall mean job response time obtained by simulation is very close to that obtained analytically. Also, the simulation results show that th e performance of the proposed load balancing policy outperforms that of theRandom and Uniform distribution load balancing policies in terms of mean job response time. The maximumimprovement ratio obtained when the system workload is low. It decreases slowly as the system workload gradually increases and it decreases rapidly when the system arrival rate λ approaches the system processing rate µ because the system gradually approaches its saturation point.

Two field experiments, were conducted during 2002/2003, 2003/2004 at Awish El-Hagar village, Mansoura city, Dakahlia Governorate to study the effect of irrigation frequency (one, two and three irrigations besides to sowing irrigation), nitrogen fertilization (0, 25 and 50 kg N/fed.) and their interaction on growth, mineral composition, yield and its components of broad bean (Vicia faba L.) plants. The results summarized as follows : (1) Increasing watering number from one to three resulted in significant responses and increments in all growth characters, N, P and K concentration of leaves, number of pods /plant, pod diameter, pod yield / plant and total yield / fed. of broad bean plants during the two seasons. There was no satisfactory differences in pod yields between two and three irrigation treatments. (2) Increasing N rate from 0 up to 50 kg N/fed. significantly increased tillering, and dry matter accumulation potential, also mineral concentration, pod yield and its components in the two seasons. The results prove also, the importance of N fertilization and insufficienty of the fixed nitrogen for optimum performances and maximum yield for broad bean. (3) In similar trend, the interaction gave significant effects on the whole performances of broad bean plants, during both seasons. The present study concluded that, for obtaining the best growth, mineral concentration and maximum productivity of broad bean crop, it could be fertilized with nitrogen 50 kg N /fed. and irrigated two times (just before the beginning of flowering and at the beginning of pod formation) after sowing irrigation.

We consider a distributed computer system in Wardrop equilibrium, i.e., situations where no user can reduce its own response time by unilaterally choosing another path, if all the other users retain their present paths. The Braess paradox is a famous example of paradoxical cases where adding capacity to a network degrades the performance of all users. This study examines numerically some examples around the Braess-like paradox in a distributed computer system. We found that Braess’s paradox can occur, namely in equilibrium the mean job response time in the network after adding a communication line for the sharing of jobs between nodes, for some system parameter setting, can be greater than the mean job response time in the network before adding the communication line. Indeed, two different types of paradox called weak and strong paradox have been characterized. In the range of parameter values examined, the worst case ratio of performance degradation obtained in the examined network model is about 75% and 65% for the cases of weak and strong paradox respectively.

A distributed computer system is considered to be a collection of autonomous computers (nodes) located at possibly different sites and connected by a communication network. Through the communication network, resources of the system can be shared by users at different locations. Performance enhancement is one of the most important issues in distributed systems. The performance of a distributed computer system can often be improved to an acceptable level by redistributing the workload among nodes. The problem of load redistribution in distributed computer systems is called load balancing. Load balancing policies may be either static or dynamic. Static load balancing policies use only the statistical information on the system (e.g., the average behavior of the system) in making load balancing decisions. On the other hand, dynamic load balancing policies attempt to dynamically balance the workload reflecting the current system state and are therefore thought to be able to further improve the system performance. Generally, the purpose of load balancing policies either static or dynamic is to improve the performance of the system by redistributing the workload among nodes. We can choose between several distinct objectives for performance optimization in many systems including communication networks, distributed computer systems, transportation flow networks, etc. Among them, we have the following three typical objectives or optima: ..., 2003, Includes bibliographical references