29 research outputs found

    Unsteady Aerodynamics of Highly Maneuvering Flyers

    Get PDF
    In this chapter, a set of analytical aerodynamic models, based on potential flow, that can be used to predict the unsteady lift response during pitching maneuvers are presented and assessed. The result examines the unsteady lift coefficients experienced by a flat plate in high-amplitude pitch ramp motion. The pitch ramps are chosen based on two ramp pitch maneuvers of a maximum amplitudes of 25 and 45 degrees starting from zero degree. The aim is investigate the use of such classical models in predicting the lift dynamics compared to a full physical-based model. Among all classical methods used, the unsteady vortex lattice method (without considering the leading edge vortex) is found to be a very good predictor of the motion lift dynamic response for the 25 ° ramp angle case. However, at high pitch maneuvers (i.e.,the 45 ° ramp angle case), could preserve the response pattern with attenuated amplitudes without high computational burden. These mathematical analytical models presented in this chapter can be used to obtain a fast estimate for aircraft unsteady lift during pitch maneuvers instead of high fidelity models, especially in the early design phases

    Towards an approach for web services substitution

    Get PDF
    This paper presents an approach whose objective is to support Web services substitution. Substitution means replacing a component with another component, as long as the replacing component produces the same output and satisfies the same requirements as the replaced component. Motives for substitution include Web service\u27s non-responsiveness to client requests and better arrangement with another, competitor Web service. To perform Web services substitution with less impact on the ongoing, and sometimes critical, business processes, the approach proposes deploying communities of Web services. A community promotes the dynamic binding of Web services through a common interface, known as Open Service Connectivity. The Open Service Connectivity directs requests to and responses from Web services regardless of how these latter are specified, implemented, and located. © 2006 IEEE

    A Multi-Layer and Multi-Perspective Approach for Web Services Composition

    Get PDF
    This paper presents a Web services composition approach that is built upon three layers known as component, community, and composite. The contribution of each layer towards this composition approach is assessed from two perspectives known as organization and management. Furthermore this paper discusses how Web services in a community are specialized into abstract and concrete. Interactions between abstract/concrete Web services and composite Web services happen through a driver known as open service connectivity. This driver permits first, binding any abstract Web service to any composite Web service and second, triggering any concrete Web service from any composite Web service

    Procjena stanja okoliša u odnosu na prostornu rasprostranjenost zooplanktonske zajednice u egipatskom jezeru Manzalah

    Get PDF
    Lake Manzalah is the largest of the four Nile Delta lakes in Egypt. It provides more than 50% of the total inland fisheries of the country. During the last two decades the Lake has been exposed to multiple changes mainly due to local human activities. Monthly zooplankton samples were collected during an integrated environmental monitoring program within the MELMARINA Project that extended from July 2003 to September 2004 to study the distribution and occurrence of zooplankton community in Lake Manzalah. Results showed that, the average zooplankton standing crop was 1277 x 103 individuals m-3 . Spring was the most productive season (2127 x 103 individuals m-3 ) representing 41.65% to the total zooplankton counts. Five groups dominated zooplankton community; Rotifera, Copepoda, Ostracoda, Protozoa and Cladocera. The meroplanktonic larvae of Polychaeta, Cirripedia, Mysidacea and Gastropoda as well as free living nematods were rarely recorded. Rotifera contributed 81.89% to the total zooplankton community. They were represented by 38 species belonging to 19 genera dominated by genus Brachionus (86.65% of the total Rotifera) followed by genus Keratella (8.68%). Keratella species has been indicated as an indicator of pollution. Copepoda (including their larval stages) was the second group in order of abundance forming about 14.28% of the total zooplankton counts and represented by seven species. Acanthocyclops americanus was the dominant species. The productivity of Lake Manzalah decreased from 1979 to become highly eutrophic lake during the present study, but with higher production than the other Egyptian lakes. Management is needed to stabilize the Manzalah lake ecosystem in a way that promotes the sustainability of the system.Jezero Manzalah najveće je od četiri jezera u egipatskom dijelu delte rijeke Nil. Iz njega se izlovljava više od 50% ukupnog ribarstva kopnenih voda u zemlji. Tijekom posljednja dva desetljeća jezero je bilo izloženo brojnim promjenama uglavnom zbog antropogenih lokalnih aktivnosti. Mjesečni uzorci zooplanktona sakupljani su za vrijeme integriranog programa praćenja stanja okoliša u sklopu projekta MELMARINA kojim se od srpnja 2003. do rujna 2004. proučavala raspodjela i učestalost zooplanktonske zajednice u jezeru Manzalah. Rezultati su pokazali da je prosječna gustoća populacije zooplanktona iznosila 1277 jedinki m-3 . Tijekom proljeća je zabilježena najveća produktivnost (2127×103 jedinki m-3 ) koja predstavlja 41.65% od ukupnog broja zooplanktona. U zooplanktonskoj zajednici prevladavalo je pet skupina: Rotifera, Copepoda, Ostracoda, Protozoa i Cladocera, dok su meroplanktonske larve Polychaeta, Cirripedia, Mysidacea i Gastropoda kao i slobodne živuće nematode rijetko zabilježene. Skupina Rotifera doprinosila je 81.89% od ukupnog broja zooplanktona. Zastupljeno je 38 vrsta koje spadaju u 19 rodova kojima dominira rod Brachionus (86.65% od ukupnog broja Rotifera). Slijedi genus Keratella (8.68%) koji se smatra pokazateljem zagađenja. Veslonošci (uključujući ličinačke stadije) su bili na drugom mjestu po zastupljenosti (14.28%), sa zabilježenih sedam vrsta, od kojih je dominantna bila Acanthocyclops americanus. Produktivnost jezera Manzalah je smanjena od 1979. godine i jezero je postalo vrlo eutrofično za vrijeme ove studije, no još uvijek je produktivnije od ostalih egipatskih jezera. Potrebno je ciljano upravljanje kako bi se stabilizirao ekosustav jezera Manzalah na način koji će unaprijediti održivost sistema

    Impact of a suggested nursing protocol on the occurrence of medical device-related pressure ulcers in critically ill patients

    Get PDF
    Aim: Medical Device-Related Pressure Ulcers are skin breakdowns related to certain medical devices that increase morbidity, lengthen hospital stays, and increase the cost of treatment. Approximately one third of reported pressure ulcers are associated with medical devices. The aim of this study is to examine the impact of a suggested nursing intervention protocol on the occurrence of medical device-related pressure ulcers in critically ill patients. Design: A prospective, quasi-experimental research design was used in this study. Methods: 100 patients participated in our study, divided into study and control groups. The researchers selected Endo-tracheal and Nasogastric tubes to examine their association with the development of pressure ulcers. The researchers observed the prevalence of pressure ulcers caused by the selected devices through daily clinical observation. Patients receiving routine care were used as a control group, while the suggested nursing intervention protocol was implemented to the study group of patients. The results of the given protocol on the study subjects were compared to the collected base line data for the control group. Results: The study revealed a highly statistically and clinically significant difference between the study and control groups in relation to incidence of endo-tracheal and nasogastric tube pressure ulcers. The results indicate that the incidence of endo-tracheal tube pressure ulcers decreased from 90% to 32.1% after implementation of the suggested nursing intervention protocol (p = 0.031), whereas the incidence of nasogastric tubes pressure ulcers fell from 77.8% to 13.1% (p = 0.012). Conclusion: the examined evidence based suggested nursing intervention protocol proved highly effective in reducing the occurrence of selected Medical Device-Related Pressure Ulcers in critically ill patients

    Review on carbonation study of reinforcement concrete incorporating with bacteria as self-healing approach

    Get PDF
    This study carried out a comprehensive review to determine the carbonation process that causes the most deterioration and destruction of concrete. The carbonation mechanism involved using carbon dioxide (CO2 ) to penetrate the concrete pore system into the atmosphere and reduce the alkalinity by decreasing the pH level around the reinforcement and initiation of the corrosion process. The use of bacteria in the concrete was to increase the pH of the concrete by producing urease enzyme. This technique may help to maintain concrete alkalinity in high levels, even when the carbonation process occurs, because the CO2 accelerates to the concrete and then converts directly to calcium carbonate, CaCO3 . Consequently, the self-healing of the cracks and the pores occurred as a result of the carbonation process and bacteria enzyme reaction. As a result of these reactions, the concrete steel is protected, and the concrete properties and durability may improve. However, there are several factors that control carbonation which have been grouped into internal and external factors. Many studies on carbonation have been carried out to explore the effect of bacteria to improve durability and concrete strength. However, an in-depth literature review revealed that the use of bacteria as a self-healing mechanism can still be improved upon. This review aimed to highlight and discuss the possibility of applying bacteria in concrete to improve reinforcement concrete

    Investigating Bisphenol A Level Estimation and Possible Effects on Fetal Biometry

    Get PDF
    Background: The estrogenic endocrine disruptor bisphenol A (BPA), which is used in plastics and resins, may have an impact on the fetus’s growth and development and can modify postnatal development. This study aims to assess how bisphenol A affects fetal biometry.Methods: This analytical cross-sectional study included 384 healthy Egyptian women in their third trimester during childbearing (15–44 years). They were selected from the outpatient Clinic of Obstetrics and Gynecology at Kasr El-Ainy Hospital, Cairo, Egypt. Fetal biometry was measured and urine samples were collected to estimate BPA levels. Results: Fetal weight, centile, and corrected bisphenol A levels were significantly higher in the studied age groups (P<0.05). A significant positive correlation was found between BPA level and estimated fetal weight, centile, and age of the mother per year. On the other hand, no significant difference was detected with other fetal measurements in the studied groups (P>0.05).Conclusion: Fetal exposure to BPA is associated with higher estimated fetal weight and centile commonly in the maternal age range 25 to 35 years

    Marine yeast isolation and industrial application

    Get PDF
    Over the last century, terrestrial yeasts have been widely used in various industries, such as baking, brewing, wine, bioethanol and pharmaceutical protein production. However, only little attention has been given to marine yeasts. Recent research showed that marine yeasts have several unique and promising features over the terrestrial yeasts, for example higher osmosis tolerance, higher special chemical productivity and production of industrial enzymes. These indicate that marine yeasts have great potential to be applied in various industries. This review gathers the most recent techniques used for marine yeast isolation as well as the latest applications of marine yeast in bioethanol, pharmaceutical and enzyme production fields. Keyword

    Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

    Get PDF
    BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

    Injection Drug Use Is a Risk Factor for HCV Infection in Urban Egypt

    Get PDF
    OBJECTIVE: To identify current risk factors for hepatitis C virus (HCV) transmission in Greater Cairo. DESIGN AND SETTING: A 1:1 matched case-control study was conducted comparing incident acute symptomatic hepatitis C patients in two "fever" hospitals of Greater Cairo with two control groups: household members of the cases and acute hepatitis A patients diagnosed at the same hospitals. Controls were matched on the same age and sex to cases and were all anti-HCV antibody negative. Iatrogenic, community and household exposures to HCV in the one to six months before symptoms onset for cases, and date of interview for controls, were exhaustively assessed. RESULTS: From 2002 to 2007, 94 definite acute symptomatic HCV cases and 188 controls were enrolled in the study. In multivariate analysis, intravenous injections (OR = 5.0; 95% CI = 1.2-20.2), medical stitches (OR = 4.2; 95% CI = 1.6-11.3), injection drug use (IDU) (OR = 7.9; 95% CI = 1.4-43.5), recent marriage (OR = 3.3; 95% CI = 1.1-9.9) and illiteracy (OR = 3.9; 95% CI = 1.8-8.5) were independently associated with an increased HCV risk. CONCLUSION: In urban Cairo, invasive health care procedures remain a source of HCV transmission and IDU is an emerging risk factor. Strict application of standard precautions during health care is a priority. Implementation of comprehensive infection prevention programs for IDU should be considered
    corecore