990 research outputs found

    Performance Evaluation of Fuel Cell and Microturbine as Distributed Generators in a Microgrid

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    This paper presents dynamic models of distributed generators (DG) and investigates dynamic behaviour of the DG units within a microgrid system. The DG units include micro turbine, fuel cell and the electronically interfaced sources. The voltage source converter is adopted as the electronic interface which is equipped with its controller to maintain stability of the microgrid during small signal dynamics. This paper also introduces power management strategies and implements the DG load sharing concept to maintain the microgrid operation in standalone, grid-connected and islanding modes of operation. The results demonstrate the operation and performance of the microturbine and SOFC as distributed generators in a microgrid. Keywords: Microgrid, Distributed Generation, Microturbine, Fuel Cel

    The financial performance of small firms in Lebanon (1975-1986)

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    The purpose of this thesis is to contribute to a better understanding of the financial performance of small businesses. This work represents a contribution to the literature on the subject. The methodology adopted may perhaps be also applied to small business in many developing countries. The approach takes the form of a multi-stage model assessing the firm's financial performance. This is applied to small firms in Lebanon during the war period between 1975 and 1985.A review of the literature on financial performance is presented identifying the key issues of concern and debate where research was needed with special concentration on small firms. Furthermore, an extensive and original historical review of the literature which chronologically describes the Lebanese socioeconomic system is presented. Severed hypotheses were formed and tested practically through cut original survey undertaken in Lebanon which included 75 small manufacturing firms. The financial performance of these firms was tested extensively in terms of their manpower, financial management, structure, finance, profit and growth and the environment. The results enabled the major hypotheses to be proven. It has been demonstrated that changes in the economic and financial resources of the country as a result of the wcw have lead to a radical change in the structure of small firm. Much criticism has been made of government policy because of the limited contribution the government has made to the financing of small manufacturing firms. The major conclusions are discussed and a series of recommendations for policy makers were indicated together with suggestions for further research topics

    Programmes de nutrition au sein des centres de sante communautaires: rôle dans l’amélioration de la prise en charge des femmes enceintes.

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    Au Mali, l’incidence de l’anémie ferriprive au cours de la grossesse est élevée. Pour contribuer à la réduction de cette anémie, un projet visant à renforcer les connaissances des professionnels de la santé en nutrition périnatale et sensibiliser les femmes enceintes pour une bonne supplémentation en fer/folate a été initié dans 14 centres de santé à Bamako. Cette étude a évalué les activités de ce projet au cours des six premiers mois de sa mise en oeuvre. Les connaissances des professionnels ont été évaluées par un questionnaire; les pratiques des sages-femmes et matrones ont été observées durant les consultations et les registres ont été utilisés pour recueillir les données rétrospectives (6 mois) et prospectives (6 mois) sur le nombre de sessions d’éducation en nutrition tenues ; le nombre de participantes à ces sessions et la quantité des comprimés de fer/folate vendus. Les résultats ont montré que les sessions d’éducation nutritionnelle sont passées de 13% à 40% de l’ensemble des sessions pour la santé et le nombre des femmes qui y ont participé a augmenté de 2.016 à 11.079. La moyenne mensuelle des comprimés de fer/folate vendus au sein des pharmacies des centres aux femmes enceintes est passée de 20.030±3.764 à 38.005±2.412 (P < 0,05) et les sages-femmes et matrones ont incorporé les conseils nutritionnels dans leur pratique quotidienne. Ce programme de nutrition a pu être intégré facilement dans les activités de routine des services de santé. Il a permis d’améliorer les connaissances du personnel et la qualité des services offerts aux femmes enceintes.MOTS CLES: Femmes enceintes - Santé communautaire - Nutrition - Anémie - Fer/Folate - Mali

    Screening Stylo accessions for anthracnose tolerance: Preliminary report

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    Evaluates the susceptibility of stylo to anthracnose on 17 Stylosanthes guianensis lines acquired from CIAT and on two reference materials Cook and Verano stylo. Describes the two experiment sites-Kaduna and Kacchia. Presents data on disease score and fungal types isolated from samples of screened stylo lines and dry-matter & herbage crude protein of 19 stylo accessions

    Impacts of Different Water Pollution Sources on Antioxidant Defense Ability in Three Aquatic Macrophytes in Assiut Province, Egypt

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    The present study was undertaken to evaluate the impacts of surface water pollution with wastes coming from sewage effluents (Site 2), agricultural runoff (Site 4) and oils and detergents factory (Site 3) on the stability of leaf membrane (measured as injury %), hydrogen peroxide (H2O2), ascorbic acid (Asc A), lipid peroxidation, chlorophyll (Chl) content, soluble sugars (SS), soluble proteins (SP) and total free amino acids (TAA) of Cyperus alopeucroides, Persicaria salicifolia and Echinochloa stagnina. Concentration of H2O2, MDA and TAA were higher in the three plants collected from polluted sites as compared with those of plants grown in control Nile site (Site1). The opposite was true for Asc A, SS and SP where their concentrations reduced significantly in response to water pollution. Leaf membrane was more damaged (high injury %) in plants exposed to wastes from different sources than in plants growing at control site. The results of this study indicated that water pollution reduced the oxidative defense abilities in the three plants through reduction of Asc A activities, enhancement of H2O2 production and increasing MDA accumulation. In addition it impaired the metabolic activity through lowering the SS and SP contents and enhancement of TAA accumulation and increase membrane injury. The over production of hydrogen peroxide by the studied aquatic plants under water pollution could be used as an oxygen source needed to oxidize the more resistant organic and inorganic pollutants and used for pollution control and municipal and industrial wastewater treatment

    Ductal Carcinoma in situ of the female Breast

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    The breast is the most common site of cancer in females in many parts of the world. Mammary carcinoma is either ductal arising from ducts or lobular arising from lobules. When ductal carcinoma is still confined to the mother duct it is called ductal carcinoma in situ "DCIS" &amp; when confined to the lobules it is called lobular carcinoma in situ "LCIS"

    Occurrence of Virulent and Antibiotic-resistant Enteropathogenic and Shiga toxin- producing Escherichia coli in some Milk Products Sold in Assiut City, Egypt

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    This study was undertaken to detect the enteropathogenic and shiga toxin-producing Escherichia coli (EPEC and STEC) in 120 milk products samples (soft cheese, hard cheese, yoghurt and ice cream). All samples were submitted for bacteriological examination, serological and molecular identification of virulent and antibiotic resistant genes using eaeA, hylA, blaTEM, blaCTX-M1, blaOXA and blaSHV primers. The bacteriological examination revealed that the incidence of occurrence of EPEC was 3.33% in ice cream samples, while it could not isolated from other types of milk products. In addition, STEC failed to detect in all examined milk products. The isolated EPEC strain following E. coli O18 serotyping. Moreover, the molecular identification of the isolated strain revealed that the strain contains eaeA, blaTEM and blaCTX-M1 genes

    TRADITIONAL TO RECENT APPROACHES IN HERBAL MEDICINE THERAPY OF COVID-19

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    Coronavirus pneumonia disease (COVID-19) is a newly identified coronavirus strain that causes symptoms ranging from cold-like signs to deaths that reached millions around the world. Until this time, there is no approved vaccine has been invented for clinical use, therefore, developing an effective program for therapy is of high priority to save the lives of patients and protect others from being infected. Nature resembles a huge reservoir of anti-infectious compounds, from which innovative ideas, therapies, and products can be deduced. Chinese herbal medicine had succeeded in the treatment of other coronavirus pneumonia such as SARS, MERS and, H7N9 avian influenza which gives us hope to find the targeted remedy in the traditionally used natural herbs consumed by natives from different regions. This work aims to highlight the use of natural traditional remedies to treat viral pneumonia. This systematic review will include studies of the effects of traditional herbal medicine and its role in the treatment of COVID-19 pneumonia. Although promising results were obtained in many cases, but, only a few studies reported the fractional characterization of bioactive principles and/or mechanisms of action. It is requested that pharmaceutical industries, government agencies, and the scientific community will have a gaze at some of these plants for future research and, to find a potential drug candidates for the development of anti-SARSCoV-2 therapeutics in the near future. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Peer Review History: Received: 6 September 2020; Revised: 10 October; Accepted: 25 October, Available online:&nbsp;15 November 2020 Academic Editor: Dr. Sally A. El-Zahaby, Pharos University in Alexandria, Egypt, [email protected] UJPR follows the most transparent and toughest ‘Advanced OPEN peer review’ system. The identity of the authors and, reviewers will be known to each other. This transparent process will help to eradicate any possible malicious/purposeful interference by any person (publishing staff, reviewer, editor, author, etc) during peer review. As a result of this unique system, all reviewers will get their due recognition and respect, once their names are published in the papers. We expect that, by publishing peer review reports with published papers, will be helpful to many authors for drafting their article according to the specifications. Auhors will remove any error of their article and they will improve their article(s) according to the previous reports displayed with published article(s). The main purpose of it is ‘to improve the quality of a candidate manuscript’. Our reviewers check the ‘strength and weakness of a manuscript honestly’. There will increase in the perfection, and transparency. Received file:&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Reviewer's Comments: Average Peer review marks at initial stage: 5.0/10 Average Peer review marks at publication stage: 7.0/10 Reviewer(s) detail: Prof. Dr. Ali Gamal Ahmed Al-kaf, Sana'a university, Yemen, [email protected] Prof. Dr. Amani S. Awaad, College of Pharmacy, Prince&nbsp;Sattam Bin Abdulaziz University, Al-Kharj. KSA. [email protected] Similar Articles: EUCALYPTUS ESSENTIAL OIL; AN OFF-LABEL USE TO PROTECT THE WORLD FROM COVID-19 PANDEMIC: REVIEW-BASED HYPOTHESES THE RISKS AND ADVANTAGES OF ANTI-DIABETES THERAPY IN THE POSITIVE COVID-19 PATIEN

    Electrohydrodynamic Kelvin-Helmholtz instability for a velocity stratified fluid

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    AbstractThe electrohydrodynamic stability of a conducting incompressible stratified fluid topping a dielectric fluid layer is studied. The stability of the system is discussed theoretically and numerically. It is found that the normal electric field has a destabilising effect while the increase of the thickness of the layer has a stabilising influence. The special case of the Rayleigh-Taylor instability is also examined
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