91 research outputs found

    Performance Enhancement of a Variable Speed Permanent Magnet Synchronous Generator Used for Renewable Energy Application

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    The paper aims to develop an improved control system to enhance the dynamics of a permanent magnet synchronous generator (PMSG) operating at varying speeds. The generator dynamics are evaluated based on lowing current, power, and torque ripples to validate the effectiveness of the proposed control system. The adopted controllers include the model predictive power control (MPPC), model predictive torque control (MPTC), and the designed predictive voltage control (PVC). MPPC seeks to regulate the active and reactive power, while MPTC regulates the torque and flux. MPPC and MPTC have several drawbacks, like high ripple, high load commutation, and using a weighting factor in their cost functions. The methodology of designed predictive voltage comes to eliminate these drawbacks by managing the direct voltage by utilizing the deadbeat and finite control set FCS principle, which uses a simple cost function without needing any weighting factor for equilibrium error issues. The results demonstrate several advantages of the proposed PVC technique, including faster dynamic response, simplified control structure, reduced ripples, lower current harmonics, and decreased computational requirements when compared to the MPPC and MPTC methods. Additionally, the study considers the integration of blade pitch angle and maximum power point tracking (MPPT) controls, which limit wind energy utilization when the generator speed exceeds its rated speed and maximize wind energy extraction during wind scarcity. In summary, the proposed PVC enhanced control system exhibits superior performance in terms of dynamic response, control simplicity, current quality, and computational efficiency when compared to alternative methods

    Techno-Economical Optimization for River Nile Container Ships

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    This work introduces a procedure for the preliminary design of a self-propelled container ship working between Cairo and Aswan through the River Nile. The characteristics of the navigation route from Cairo to Aswan are investigated to defi ne the constraints on dimensions and speed of the River Nile container ships. Also, the dimensions of some existing inland ships are collected and investigated to set limits on the dimensional ratios of such ships. Two empirical formulae, for the determination of ship steel weight and power prediction in the preliminary design stage of conventional self propelled inland container ships, are proposed. This problem is handled as a single objective constrained optimization problem using a specially developed computer program (CACSO). As the required freight rate refl ects the major goal of any commercial ship, it is considered as the objective function for this optimization process. A sensitivity study is carried out to indicate the relative dependence of the objective function on a variety of factors to which the objective function may be sensitive

    Concerns, perceived impacts and preparedness of health care workers in a referral hospital in Egypt in facing influenza (H1N1) epidemic

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    Objective. In Egypt, influenza A(H1N1) cases have been detected and deaths have been reported. The aim of this study was to investigate Concerns, Perceived Impacts and Preparedness of Physicians and Nurses of Chest Specialty Hospital in Cairo (Egypt) concerning Influenza A(H1N1). Methods. A questionnaire was applied to a total of 72 Physicians and 41 Nurses from Chest Specialty Hospital in Cairo (Egypt). Results. More than half of physicians (55.6%) were men, while most of nurses (92.7%) were women. The mean age in years of physicians was 36.6 ± 11.3 compared to 26.5 ± 8 in nurses. Physicians feel that they are at greater risk by their job to the pandemic100% compared to 87.6% among nurses and the difference is highly significant. More than one third of the studied physicians reported that they are not ready to face H1N1 pandemic. Residents feel less ready to face the danger of Influenza A(H1N1) compared with Consultants and Specialists/Assistant Specialists, with no statistical significant difference. In concordance, Residents reported less Personal Protective Equipment training compared with Consultants and Specialists/Assistant Specialists, with no statistical significant difference. All Consultants received Seasonal Influenza Vaccine compared with Specialists/Assistant Specialists (68.2%) and Residents (44.7%). Conclusion. Higher work related and non work related stress was found among physicians compared to nurses, which reflects the demand of more information and training courses for physicians about the pandemic nature and its consequences, complications, and methods infection prevention

    Techno-Economical Optimization for River Nile Container Ships

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    This work introduces a procedure for the preliminary design of a self-propelled container ship working between Cairo and Aswan through the River Nile. The characteristics of the navigation route from Cairo to Aswan are investigated to defi ne the constraints on dimensions and speed of the River Nile container ships. Also, the dimensions of some existing inland ships are collected and investigated to set limits on the dimensional ratios of such ships. Two empirical formulae, for the determination of ship steel weight and power prediction in the preliminary design stage of conventional self propelled inland container ships, are proposed. This problem is handled as a single objective constrained optimization problem using a specially developed computer program (CACSO). As the required freight rate refl ects the major goal of any commercial ship, it is considered as the objective function for this optimization process. A sensitivity study is carried out to indicate the relative dependence of the objective function on a variety of factors to which the objective function may be sensitive

    The Egyptian Arabic version of the Juvenile Arthritis Multidimensional Assessment Report (JAMAR)

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    The Juvenile Arthritis Multidimensional Assessment Report (JAMAR) is a new parent/patient-reported outcome measure that enables a thorough assessment of the disease status in children with juvenile idiopathic arthritis (JIA). We report the results of the cross-cultural adaptation and validation of the parent and patient versions of the JAMAR in the Egyptian Arabic language. The reading comprehension of the questionnaire was tested in ten JIA parents and patients. Each participating centre was asked to collect demographic, clinical data and the JAMAR in 100 consecutive JIA patients or all consecutive patients seen in a 6-month period and to administer the JAMAR to 100 healthy children and their parents. The statistical validation phase explored descriptive statistics and the psychometric issues of the JAMAR: the 3 Likert assumptions, floor/ceiling effects, internal consistency, Cronbach\u2019s alpha, interscale correlations, test\u2013retest reliability, and construct validity (convergent and discriminant validity). A total of 100 JIA patients (20.0% systemic JIA, 40.0% undifferentiated arthritis, 24.0% RF negative polyarthritis, 16.0% other categories) and 100 healthy children were enrolled in one paediatric rheumatology centre. The JAMAR components discriminated well healthy subjects from JIA patients. All JAMAR components revealed satisfactory psychometric performances. In conclusion, the Egyptian Arabic version of the JAMAR is a valid tool for the assessment of children with JIA and is suitable for use both in routine clinical practice and in clinical research

    Consensus evidence-based recommendations for treat-to-target management of immunoglobulin A vasculitis

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    IgA vasculitis (IgAV), formerly known as Henoch-Schönlein purpura, is the most common cause of systemic vasculitis in childhood. Given its potential life-threatening systemic complications, early and accurate diagnosis as well as management of IgAV represent a major challenge for health care professionals. This study was carried out to attain an evidence-based expert consensus on a treat-to-target management approach for IgAV using Delphi technique. The preliminary scientific committee identified a total of 16 key clinical questions according to the patient, intervention, comparison, and outcomes (PICO) approach. An evidence-based, systematic, literature review was conducted to compile evidence for the IgAV management. The core leadership team identified researchers and clinicians with expertise in IgAV management in Egypt upon which experts were gathered from different governorates and health centers across Egypt. Delphi process was implemented (two rounds) to reach a consensus. An online questionnaire was sent to expert panel (n = 26) who participated in the two rounds. After completing round 2, a total of 20 recommendation items, categorized into two sections were obtained. Agreement with the recommendations (rank 7–9) ranged from 91.7–100%. Consensus was reached (i.e. ⩾75% of respondents strongly agreed or agreed) on the wording of all the 20 clinical standards identified by the scientific committee. Algorithms for the diagnosis and management have been suggested. This was an expert, consensus recommendations for the diagnosis and treatment of IgAV and IgA vasculitic nephritis, based on best available evidence and expert opinion. The guideline presented a strategy of care with a pathway to achieve a state of remission as early as possible

    Epidemiology of hepatitis viruses among hepatocellular carcinoma cases and healthy people in Egypt: A systematic review and meta-analysis

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    Liver cancers are strongly linked to hepatitis B virus (HBV) and hepatitis C virus (HCV). Egypt has the highest prevalence of HCV worldwide and has rising rates of hepatocellular carcinoma (HCC). Egypt's unique nature of liver disease presents questions regarding the distribution of HBV and HCV in the etiology of HCC. Accordingly, a systematic search of MEDLINE, ISI Web of Science, ScienceDirect and World Health Organisation databases was undertaken for relevant articles regarding HBV and HCV prevalence in Egypt among healthy populations and HCC cases. We calculated weighted mean prevalences for HBV and HCV among the populations of interest and examined differences in prevalence by descriptive features, including age, year and geographic region. Prevalences for HBV and HCV were 6.7% and 13.9% among healthy populations, and 25.9% and 78.5% among HCC cases. Adults had higher prevalences of both infections (Adult HBV = 8.0%, Child HBV = 1.6%; Adult HCV = 15.7%, Child HCV = 4.0%). Geographically, HBV was higher in the south, whereas HCV was greater in the north (North HBV = 4.6%, South HBV = 11.7%; North HCV = 15.8%, South HCV = 6.7%). Among HCC cases, HBV significantly decreased over time ( p = 0.001) while HCV did not, suggesting a shift in the relative influences of these viruses in HCC etiology in Egypt. Our results highlight large amounts of heterogeneity among the epidemiological factors associated with liver disease in Egypt and underscore the necessity of an integrated strategy for the successful prevention of viral hepatitis infections and chronic liver disease. © 2008 Wiley-Liss, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/61320/1/23937_ftp.pd

    Egyptian consensus on treat-to-target approach for osteoporosis: a clinical practice guideline from the Egyptian Academy of bone health and metabolic bone diseases

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    Background: This study was carried out to achieve an Egyptian expert consensus on a treat-to-target managementstrategy for osteoporosis using Delphi technique. A scientific committee identified researchers and clinicians with expertise in osteoporosis in Egypt. Delphi process was implemented (2 rounds) to establish a consensus on 15 clinical standards: (1) concept, (2) diagnosis, (3) case identification, (4) whom to treat, (5) who should treat?, (6) case stratification and intervention thresholds, (7) falls risk, (8) investigations, (9) treatment target, (10) management, (11) optimum treatment duration, (12) monitoring, (13) drug holiday, (14) osteoporosis in men, and (15) post-fracture care and fracture liaison service. Results: The surveys were sent to an expert panel (n = 25), of whom 24 participated in the two rounds. Respondents were drawn from different governorates and health centres across Egypt including the Ministry of Health. Most of the participants were rheumatologists (76%), followed by internists (8%), orthopaedic doctors (4%), rehabilitation doctors (4%), primary care (4%), and ortho-geriatrics (4%) physicians. Seventy-two recommendations, categorised into 15 sections, were obtained. Agreement with the recommendations (rank 7–9) ranged from 83.4 to 100%. Consensus was reached (i.e. ≥ 75% of respondents strongly agreed or agreed) on the wording of all 15 clinical standards identified by the scientific committee. An algorithm for the management of postmenopausal osteoporosis has been suggested. Conclusion: A wide and representative panel of experts established a consensus regarding the management of osteoporosis in Egypt. The developed guidelines provide a comprehensive approach to the assessment and management of osteoporosis for all Egyptian healthcare professionals who are involved in its management

    Consensus evidence-based clinical practice recommendations for the diagnosis and treat-to-target management of osteoporosis in chronic kidney disease stages G4-G5D and post-transplantation: An initiative of Egyptian Academy of Bone Health

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    The aim of this study was to reach a consensus on an updated version of the recommendations for the diagnosis and Treat-to-Target management of osteoporosis that is effective and safe for individuals with chronic kidney disease (CKD) G4-G5D/kidney transplant. Delphi process was implemented (3 rounds) to establish a consensus on 10 clinical domains: (1) study targets, (2) risk factors, (3) diagnosis, (4) case stratification, (5) treatment targets, (6) investigations, (7) medical management, (8) monitoring, (9) management of special groups, (10) fracture liaison service. After each round, statements were retired, modified, or added in view of the experts' suggestions, and the percent agreement was calculated. Statements receiving rates of 7-9 by more than 75% of experts' votes were considered as achieving consensus. The surveys were sent to an expert panel ( = 26), of whom 23 participated in the three rounds (2 were international experts and 21 were national). Most of the participants were rheumatologists (87%), followed by nephrologists (8.7%), and geriatric physicians (4.3%). Eighteen recommendations, categorized into 10 domains, were obtained. Agreement with the recommendations (rank 7-9) ranged from 80 to 100%. Consensus was reached on the wording of all 10 clinical domains identified by the scientific committee. An algorithm for the management of osteoporosis in CKD has been suggested. A panel of international and national experts established a consensus regarding the management of osteoporosis in CKD patients. The developed recommendations provide a comprehensive approach to assessing and managing osteoporosis for all healthcare professionals involved in its management. [Abstract copyright: Copyright © 2022 by The Author(s). Published by S. Karger AG, Basel.

    Symptomatic Acute Hepatitis C in Egypt: Diagnosis, Spontaneous Viral Clearance, and Delayed Treatment with 12 Weeks of Pegylated Interferon Alfa-2a

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    The aim of this study was to estimate the proportion of spontaneous viral clearance (SVC) after symptomatic acute hepatitis C and to evaluate the efficacy of 12 weeks of pegylated interferon alfa-2a in patients who did not clear the virus spontaneously.Patients with symptomatic acute hepatitis C were recruited from two "fever hospitals" in Cairo, Egypt. Patients still viremic three months after the onset of symptoms were considered for treatment with 12 weeks of pegylated interferon alfa-2a (180 microg/week).Between May 2002 and February 2006, 2243 adult patients with acute hepatitis were enrolled in the study. The SVC rate among 117 patients with acute hepatitis C was 33.8% (95%CI [25.9%-43.2%]) at three months and 41.5% (95%CI [33.0%-51.2%]) at six months. The sustained virological response (SVR) rate among the 17 patients who started treatment 4-6 months after onset of symptoms was 15/17 = 88.2% (95%CI [63.6%-98.5%]).Spontaneous viral clearance was high (41.5% six months after the onset of symptoms) in this population with symptomatic acute hepatitis C. Allowing time for spontaneous clearance should be considered before treatment is initiated for symptomatic acute hepatitis C
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