Parametric study of an empty diffuser geometric parameters and shape for a wind turbine using CFD analysis.

This research examines the optimal 3D geometric parameters and shape of empty diffusers to enhance the mass flow rate of the HAWT rotor plane using a detailed parametric study. Previous works have investigated the use of diffusers to augment turbine power output; however, different curvature surfaces and the effects of all associated angles have not been considered for a thorough evaluation. This work mainly focuses on analyzing the effect of opening angles (2° to 22°), inlet shroud angles (8° to 24°), flange height ratios, flange angles (0° and 15°), and shape of the diffuser as well as flanges on velocity, pressure at the diffuser entry, and through the diffuser section at a wind speed of 4.5 m/s. At an inlet-shroud angle of 24° and an opening angle of 8°, with a diffuser flange height-throat diameter ratio of 0.3, the system achieved an 82.9% increase in flowrate. The diffuser with an inlet shroud-side lower stepped flange showed an optimum velocity of 9.12 m/s (maximum) and 8.2 m/s (average), resulting in a 102.66% and 82.2% increase in velocity, respectively. The percentage increase in velocity of the present study is 92.61%, compared with the previous maximum increase in rate of 53.8%, and then an increase in velocity of 38.81% was obtained. The optimum speed occurred at 0.175 m from the inlet section of the diffuser, indicating where the turbine should best be located. The CFD results from this work were validated with experimental data from the literature, showing a good agreement between the two. Integrated diffuser-turbine system simulation and experimental work with field tests are recommended as a way forward.

Toxicity study and evaluation of biochemical markers towards the identification of the causative agent for an outbreak of liver disease in Tahtay Koraro Woreda, Tigray.

BACKGROUND: A team of experts of the Faculty of Medicine, Addis Ababa University reported the emergence of unidentified fatal liver disease in Tahtay Koraro Woreda, Tigray in the mid of December 2005. The EHNRI has been then instructed to investigate the possible etiological agent that are likely to be responsible in triggering the health problem and a field survey team consisting of experts were went to the affected area to investigate the situations surrounding the disease. OBJECTIVES: This investigation was conducted to determine the possible etiological agent(s) for the stated health problem in the affected village. METHOD: Acute toxicity study was performed on animal model for the various samples used in human consumption, which was followed by histopathological examination of the liver of the sacrificed laboratory animals. In order to facilitate the elucidation of the causative agent for the alleged health problem further tests for clinical markers and antigens were also performed on the serum collected from affected persons. RESULT: Neither death nor toxic symptoms manifestations were observed on laboratory animals when feeding the consumable samples for a period of two weeks, however histopathological examination of the liver of the sacrificed animals that were given the unprotected pond water and Tela samples from the affected village as a drink revealed severe hepatoic necrosis. Biochemical test results of the serum samples revealed raised level of some clinical markers that are highly significant for detecting liver abnormality of toxic origin. Serological test for surface antigen ruled out the possible causes of infectious origin such as viral hepatitis. CONCLUSION: The overall results confirmed that the causative agent for the outbreak of the liver disease was of toxic origin rather than due to infectious agent and this was found to be associated with consumption of contaminated water as well as Tela.

Barriers to Maternal and Child Health Care Service Uptake in Assosa Zone, Benishangul Gumuz Region, Ethiopia: A Qualitative Study.

BACKGROUND: Ethiopia has reduced maternal mortality from 871 to 412 per 100,000 live births between 2000 and 2016. In 2019, under-5 mortality rates in Ethiopia were 55 deaths per 1,000 live births. Benishangul Gumuz was the second-largest region in the under-5 mortality rate (98/1,000 live births) in the country. Maternal and child health care service uptake is an important indicator of health outcomes. This study is aimed at exploring major barriers to maternal and child health care uptake in Assosa Zone. METHODS: This study was conducted in the Bambasi, Menge, and Sherkole districts of the Assosa Zone from July 17 to August 31/2019. The study explored the life experience of study participants about MCH services. The sampling technique was purposive, and data collection methods were focus group discussions, key informant interviews, and in-depth interviews. Data were analyzed thematically. RESULT: The main barriers to child health care services were financial problems, lack of knowledge, preference of traditional medicines for a sick child, women having no time to care for their sick child, poor roads. poor health facility readiness, the poor economy of families, lack of ambulance, cultural and traditional beliefs, providers being male, and unprofessional behaviors which were the major barriers hindering the uptake of maternal health service utilization. CONCLUSION: Poor health facility readiness, indirect costs, inaccessibility to health facilities, and cultural and traditional practices were among the major barriers to service uptake identified by this research in the study area.

Sero-prevalence of brucellosis in occupationally exposed people in Addis Ababa, Ethiopia.

OBJECTIVE: Brucellosis is a Zoonosis, recognized worldwide as a serious public health hazard and economically significant disease. The etiologic agent of this disease is a bacterial species of the genus Brucella that causes undulant fever, sterility and other systemic illnesses in human. Thus, the aim of this study was to undertake seroepidemiological study of brucellosis on occupationally exposed persons in Addis Ababa abattoirs enterprise and different dairy farms. METHODS: Three hundred thirty six human individuals were screened using Rose Bengal Plate Test (RBPT) and the sera were further subjected to 2- Mercapto Ethanol Test (2-MET). Simultaneously, survey was conducted in farms and slaughterhouse to investigate epidemiological factors. RESULTS: An overall seroprevalence rate of 4.8% (16/336) was determined by taking RBPT+/2MET+ as confirmatory test (P < 0.05). Some of the risk factors contributing to the occurrence of the disease include occupation, gender, and unsafe handling of infected materials. Raw milk and meat consumption, lack of awareness and use of detergents were also found as important factors. CONCLUSION: The seroprevalence of brucellosis is expected to be more in other areas of the Region, where there is high human-animal contact and high number of cattle population with a respective traditional system of animal rearing.

Endemic existence of rabies in Ethiopia.

The study on the prevalence of rabies was conducted on a retrospective data gathered from EHNRI rabies diagnostic laboratory Addis Ababa, in the years 1979-1987. During this period a total of 8036 animals were brought to the rabies diagnostic laboratory. Ninety one percent (7329) of these animals were dogs. The remaining 8.8% (707) comprised of cats, domestic animals (donkeys, cows, sheep) and wild animals (monkeys, jackals and hyenas). Out of 7329 dogs examined 832 were positive for rabies. Dogs accounted for the majority of animal rabies (94.01% of the total positive animals). The remaining 5.99% (53) of the animals diagnosed with rabies-comprised of cats, domestic animals and some wild animals. A total of 15,940 people were given post exposure anti-rabies prophylaxis treatment that came from different parts of the country in the years 1979-1987. The prevalence rates of rabies were found to be higher soon after dogs' breeding seasons. Such an observation indicates that among dogs infection, transmission through biting is significant during the breeding season. However, despite the high incidence of rabies in Ethiopia, only 320 people were reported to have died of rabies in the years 1979-1984. This supports, the hypothesis that there is a lack of appropriate reporting system on prevalence of rabies and its impact on humans in Ethiopia.