检索结果-南通市图书馆

Flow Curves in the Centered Cylindrical Couette Geometry of a Polyethylene Oxide Solution

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Open Journal of Fluid Dynamics 2017年第4期7卷 673-695页

作者： Ngargoto Ngarmoundou Rilengar Godfroyd Ousman barka mahamat Aboubaker Chedikh Beye Group of Laboratories of Physics of Solids and Materials Science (GPSSM) Department of Physics Faculty of Sciences and Techniques Cheikh Anta Diop University Dakar Senegal Department of Mechanic Faculty of Sciences and Techniques University of Mongo Mongo Chad Department of Physical Science Faculty of Exact and Applied Sciences University of N’Djamena N’Djamena Chad

Polyethylene oxide solutions have a behavioral flexibility that provides researchers with the opportunity to use constitutive law models in a variety of ways for their MRI characterization. Our results obtained in numerical simulation carried out in 2D and 3D for speed profiles of a solution of PEO deployed by the simple method of the cylindrical Couette geometry considering the fluid Newtonian defect, allowed to identify the behavior of fluid complex (rheo-fluidifying threshold fluid). The relevance and the interest of the method are examined by analyzing these results generated by the numerical data obtained, since these profiles depend on the non-Newtonian properties of the fluid which one does not know a priori and which one seeks to measure by postulating first to the power law of Ostwald, then to the truncated power law.

关键词： Rheology Behavior Polyethylene Oxide Couette Geometry Viscosity Speed Profiles Shear Stress Shear Bands Shear Rate Localization Rheo-Fluidifying Threshold

Prevalence and Risk Factors of Hepatitis B among the Population at Algamosi Locality, Gezira State, Sudan

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Health 2022年第12期14卷 1191-1198页

作者： Youssouf Amine Goni Mohamed Abdelsalam Adoum Doutoum Ali barka mahamat Djamalladine mahamat Doungous Abdelsafi Abass Gabbad Rania Mohamed Osmab Department of Biomedical and Pharmaceutical Sciences National Institute of Sciences and Techniques of Abéché Abéché Chad Department of Epidemiology Faculty of Public and Environmental Health University of Khartoum Khartoum Sudan Department of Food and Quality Control Faculty of Public and Environmental Health University of Khartoum Khartoum Sudan

Background: The local population in developing countries is at higher risk of contracting hepatitis B (HBV) due to some of the factors they practice which promote its establishment and distribution within their communities and may constitute a burden for them. Objective: This study aimed to determine the prevalence and risk factors associated with the hepatitis B virus in populations of the Algamosi region, Gezira State, central Sudan. Method: A cross-sectional study was conducted among 492 people, populations of the Algamosi region, Gezira state in central Sudan. A questionnaire was used to collect information on socio-demographic factors, transmission, and prevention of hepatitis B infections. As well, blood samples were taken from each participant, and serum was used for rapid tests for HBsAg. Positive samples were then tested by the ELISA method for confirmation. Data were obtained using SPSS version 21 and a P value of less than 0.05 was considered statistically significant. Results: The prevalence of hepatitis B was 16.10% and was higher in men than in women (05.7 - 1.00). People aged 31 to 45 had the highest prevalence of 27 (20,600%) for HBV infection. There was a significant association between HBV and age groups (X2 = 7.816 and P value = 0.05). This study also found that there was a significant association between viral hepatitis and knowledge about transmission and prevention (P value Conclusion: Although most people who live in developing countries are at high risk for transmission of hepatitis B, this indicates the need to implement the screening policy and integrate it with other health services and create awareness such as proper treatment and surveillance for hepatitis infection in all nations.

关键词： Socio-Demographic Transmission Prevention HBV Population Gezira State Central Sudan

Factors Influencing Hepatitis C Viral Infections in the Population of Algamosi Locality, Gezira State, Central Sudan

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Biosciences and Medicines 2022年第9期10卷 332-339页

Hepatitis C (HCV) remains a global health challenge and is transmitted via contact with contaminated blood and body fluids. This study aimed To find the factors influencing hepatitis c viral infections and to identify its prevalence among populations of the Algamosi area, Gezira state central Sudan. This cross-sectional community-based study was conducted. A total of 492 participants were randomly selected from among 4 villages and were interviewed to find out the factors that lead to transmission of infection and tested for markers of hepatitis C infection. ELISA confirmed all the positive card tests. The results showed that the individuals within the age groups > 45 and 31 - 45 years are more affected by HCV the percentage was 3.37% and 0.6% respectively, while the age groups of 15 - 30 and p 2 = 14.588 and p value = 0.001) The study concluded that the prevalence of hepatitis C viruses was only detected in three areas. This study explored many possible causes associated with viral hepatitis, tattooing is the common cause of hepatitis C virus. Based on the finding the study recommends, the crucial intervention program to screen most of the Algamosi population who have been not screened for HCV, proper treatment for HCV, and the health education program is strongly recommended to create awareness among the general population.

关键词： Hepatitis C Tattooing The Population at Algamosi Locality

Long-Term Variation of Sunshine Duration and Their Inter-Action with Meteorogical Parameters over Chad, Central Africa

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Natural Resources 2019年第3期10卷 47-58页

作者： Saka Goni Haroun Ali Adannou Dialo Diop Mamadou S. Drame Bienzeube Tikri mahamat barka Aboubaker Cheidikh Beye Groupe de Laboratoire de Physique des Solides et Sciences des Matériaux Faculté des Sciences et Techniques Université Cheikh Anta Diop de Dakar Dakar Sénégal Département de Génie Industriel et Maintenance Université Polytechnique de Mongo Mongo Tchad Département Génie Chimique Institut National Supérieur de Pétrole de Mao Mao Tchad Faculté des Sciences Exactes et Appliquées Université de Ndjamena Ndjamena Tchad

This study aims to evaluate the long-term variations of sunshine duration and to estimate its interaction with meteorogical parameters from 1950 to 2010 in Chad, Central Africa. The results show that Chad is the one of world’s sunniest countries. Each year, Chad receives more than 3030.91 ± 176.33 hours of sunning corresponding to 8.9 hours daily. Likewise, a strong north-south gradient is noted over Chad. For instance, the daily insolation is 10 ± 0.41 hours in the north, 8.85 ± 1.1 hours in the center and 7.75 ± 1.8 hours in the south. Furthermore, there is a marked seasonality of sunshine duration with maximums in dry season and minimums during the rainy season. The lowest values of sunshine duration are found in August. On the contrary, maximums are recorded from November to February with values greater than 9.5 hours per day. Moreover, the annual anomalies study allowed determining three great periods in terms of sunshine variability in Chad. Firstly, the period between 1950 to 1970 (named humid period) is characterized by the lowest values of sunshine duration in Chad. Secondly, from 1970 and 1990, the region suffered an unprecedented drought which resulted in an increase of sunstroke duration in Chad. And finally, the period from 1990 to 2010 called the return period is characterized by a rapid year-to-year fluctuations of insolation duration. Unlike to surface temperature, we have also shown that there is a direct relation between the duration of insolation and the meteorological parameters such as precipitations and relative humidity.

关键词： Sunshine Duration Solar Energy Climate Variability Chad Central Africa

Upper Tract Treatment of Urogenital Fistulas at the National Fistula Treatment Center (CNTF)

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Open Journal of Urology 2024年第1期14卷 11-19页

作者： mahamat Ali mahamat Vadandi Valentin Aché Haroun Saleh Nedjim Abderassoul Abdraman Gadam Kimassoum Rimtebaye Faculty of Health Sciences University of N’Djamena N’Djamena Chad Faculty of Health Sciences University of Adam Barka Abeche Chad University Hospital of National Reference N’Djamena Chad

Introduction: Urogenital fistula is the existence of an abnormal pathway between a urinary organ and a genital organ. It is a public health problem because of its frequency and social aspect. The aim of this study was to analyse the management of urogenital fistulas by the upper route at the National Fistula Treatment Centre in N’Djamena. Material and Methods: This was a 10-year retrospective descriptive and analytical study from May 2011 to April 2021. The records of all patients who had received fistula treatment during this period were identified and analysed. Results: During the study period 2369 patients were managed for cure of urogenital fistula including 84 by the upper route, i.e. 3.5%. The mean age was 28.5 ± 8.13 years. Loss of urine was the most common reason for consultation (71.4%). Primigravida were represented in 50% (n = 42). The average gestational age was 3.2 ± 2.8 with extremes of 0 to 9 pregnancies. Obstetric aetiology was the most common (92.8%). Ureterovaginal fistulas were the most common anatomoclinical type (36.9%). Uretero-vesical reimplantation was the main surgical procedure (41.7%). Late postoperative follow-up was successful in 85.7% of cases. Conclusion: Urogenital fistulas are common in our practice. The only way to combat this scourge is through prevention through information, education and communication.

关键词： Urogenital Fistula Upper Tract CNTF N’Djamena Chad

Boundedness of Rough Operators on Grand Variable Herz Spaces

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Applied Mathematics 2021年第7期12卷 614-626页

作者： Bechir mahamat Acyl Shuangping Tao Omer Khalill College of Mathematics and Statistics Northwest Normal University Lanzhou China Faculty of Sciences and Technology Adam Barka University of Abeche Abeche Chad Faculty of Education Sudan University of Science and Technology Khartoum Khartoum State Sudan

In this paper, we prove the boundedness of Calderón-Zygmund singular integral operators TΩ on grand Herz spaces with variable exponent under some conditions.

关键词： Calderón-Zygmund Singular Integral Operator Grand Herz Spaces Variable Exponent

Phytochemical Screening, Total Phenolic and Antioxidant Activity of Numerous Extracts from Leaves and Bark of Bauhinia rufescensLam

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Food and Nutrition Sciences 2021年第6期12卷 544-556页

作者： Seid Ali mahamat Niang Lahat Ayessou Nicolas Cyrille Cisse Mady Diop Codou Mar Adam barka University Abeche Tchad Water Energy Environment and Industrial Processes Laboratory (LE3PI) ESP-UCAD Dakar Sénégal Center for Studies on Food Safety and Functional Molecules (CESAM-RESCIF) ESP-UCAD Dakar Sénégal

Researches for natural antioxidants that play an important role in the prevention of diseases linked to free radicals have increased in recent years. In this study, antioxidant activity of Bauhinia rufescens Lam which is a medicinal plant was investigated. The methanol extract, acetone extract and water extract of leaf and trunk bark had antioxidant activity. Three methods were used: 2,2-diphenyl-1picryl-hydrazyl (DPPH), 2,2’-Azino-bis-(3-ethylbenzoth iazoline-6-sulfonic acid) (ABTS) and ferric ion reducing power (FRAP) by spectrophotometry. Phytochemical screening was carried out followed by the quantification of the total phenolic by the Folin-Ciocalteu method. The analysis of variance (ANOVA) with the STATISTICA 7.1 software revealed significant differences (p 0.05). Percentage inhibition (PI) and IC50 of the extracts were obtained using the OriginPro 8.5 software. These tests show that the bark is as rich in total phenolic as the leaves. The DPPH test shows that at 2.5 mg/ml, the bark and

关键词： Bauhinia rufescens Lam Total Phenolic Antioxidant Activity

Antioxidant Activity of Hydro-Acetonic, Hydro-Methanolic and Aqueous Leaf and Bark Extracts of Sclerocaria birrea(A. Rich.) Hochst

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Food and Nutrition Sciences 2021年第5期12卷 429-438页

作者： Lahat Niang Seid Ali mahamat Nicolas Cyrille Ayessou Mady Cisse Codou Mar Diop Laboratory of Electrochemistry and Membrane Processes (LEPM) ESP-UCAD Dakar Sénégal Center for Studies on Food Safety and Functional Molecules (CESAM-RESCIF) ESP-UCAD Dakar Sénégal Adam barka University Abeche Tchad

Bioactive compounds in plants are associated with the reduction of chronic diseases. The free radical scavenging activity of different extracts of a medicinal plant, Sclerocarya birrea, has been investigated using the DPPH test, ABTS test and FRAP. Three extracts were prepared from the leaves and bark: hydro-methanolic, hydro-acetonic and aqueous. Phytochemical screening was carried out the standard methods followed by the determination of the polyphenol by Folin-Ciocalteu method. The analysis of variance (ANOVA) with the STATISTICA 7.1 and statistical significance was set at p 0.05. Evolution of percent inhibition (PI) as well as the IC50 of the extracts was obtained using the Origin Pro 8.5 software and Microsoft Excel. The results show that the bark extracts

关键词： Sclerocarya birrea Antioxidant Activity DPPH ABTS Total Phenolic

Lycopen’s Stability in Watermelon Juice (Citrullus lanatus) Regarding to Technological Routes

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Food and Nutrition Sciences 2021年第7期12卷 693-702页

作者： Seid Ali mahamat Khadim Niane Nicolas Cyrille Ayessou Alioune Sow Samba Balde Oumar Ibn Khatab Cisse Matar Coume Adam barka University Abeche Chad Water Energy Environment and Industrial Processes Laboratory (LE3PI) ESP-UCAD Dakar Senegal Center for Studies on Food Safety and Functional Molecules (CESAM-RESCIF) ESP-UCAD Dakar Senegal Gaston Berger University Saint-Louis Senegal National Institute of Agronomic Sciences (INSA) Thies Senegal

Highly prized by consumers, watermelon is rich in water, but also in micronutrients including lycopene, pigment responsible for the red color. It is also a powerful antioxidant which has many virtues including the prevention and treatment of certain diseases. The transformation into nectar of watermelons combined with treatment could cause several modifications including the alteration of coloring. It is in this context that this study focuses on the variation of the lycopene content in nectars. Thus, nectars of 12°Brix and 15°Brix were prepared from three varieties of watermelon (Sugar Baby, Crimson Sweet and Charleston Gray). To study the stability, two pasteurization scales (85°C/15min and 95°C/15min) and one sterilization scale (105°C/15min) were applied to the different n

关键词： Citrullus lanatus Nectars Variety Thermal Treatment Micronutrient