106 research outputs found
Two-phase flow characteristics in multiple orifice valves
No full textThis work presents an experimental investigation on the characteristics of two-phase flow through multiple orifice valve (MOV), including frictional pressure drop and void fraction. Experiments were carried out using an MOV with three different sets of discs with throat thickness-diameter ratios (s/d) of 1.41, 1.66 and 2.21. Tests were run with air and water flow rates ranging between 1.0 and 3.0 m(3)/h, respectively. The two-phase flow patterns established for the experiment were bubbly and slug. Two-phase frictional multipliers, frictional pressure drop and void fraction were analyzed. The determined two-phase multipliers were compared against existing correlations for gas-liquid flows. None of the correlations tested proved capable of predicting the experimental results. The large discrepancy between predicted and measured values points at the role played by valve throat geometry and thickness-diameter ratio in the hydrodynamics of two-phase flow through MOVs. A modification to the constants in the two-phase multiplier equation used for pipe flow fitted the experimental data. A comparison between computed frictional pressure drop, calculated with the modified two-phase multiplier equation and measured pressure drop yielded better agreement, with less than 20% error. (C) 2010 Elsevier Inc. All rights reserved
The conventional versus a constructionist Scratch programming and first-year students' achievements in higher education classes: experimental data.
No full textGlobally, learning or teaching the first programming (popularly called CS1) remains a significant educational challenge. Indicators such as CS1 students' engagement, failure and attrition rates, and lack of diversity, continue to show the need for innovating the learning or teaching of novice computer science students. To ease initiating novices to programming, Scratch, a visual programming language, has become a staple of K-12 CS1 classes.
As outcomes of a research project aiming to explore a constructionist Scratch pedagogy with novice CS students in higher education, we present these datasets. In the research lasting two successive academic sessions, we conducted two quasi-experimental studies involving four intact CS1 classes in selected public polytechnic in the north central Nigeria. In each study, we randomly assigned the classes to the experimental and control groups, constituting the constructionist Scratch and the conventional CS1 classes, respectively.
Instruments for collecting data include a student profile questionnaire, a pretest, and posttest. Sequel to ethical clearance and permission from the selected schools, we conducted each study during the first semester of each academic session, in the first seven to eight weeks. During the first to second week, we administered students who consented to take part with the questionnaire and the pretest. Learning or teaching in the two classes lasted six weeks. Then both classes took the posttest. An independent CS educator who is not part of this research marked all the achievement tests, following a rubric prepared by the first author. To strengthen the research design and the possibility of arriving at valid causal evidence, we employed a Coarsened Exact Matching (CEM) algorithm to generate matched samples of experimental and control data, which we used in the analysis.
Data presented here includes the raw, unmatched and matched experimental datasets from both studies. A researcher can make use of the data:
To explore if some background variables not addressed in the original research may moderate CS1 students' achievements. For instance, their prior achievements in mathematics, physics, or English.
To uncover some interesting patterns using machine learning algorithms.
To validate the outcome of the original experiment by using the unmatched, matched or newly generated matched samples.
The authors welcome further research collaborations in using the data or the accompanying research instruments.
Enable GingerCannot connect to Ginger Check your internet connection
or reload the browserDisable in this text fieldRephraseRephrase current sentence4Edit in Ginger
Book Review: African Philosophy: Reflections on Yoruba Metaphysics and Jurisprudence
No full textBook Title: African Philosophy: Reflections on Yoruba Metaphysics and JurisprudenceBook Author: Oladele Abiodun BalogunPublisher: Xcel Publishers. Pages: 387. Year of Publication: 201
Retrospective analysis of Newcastle disease diagnosed at the poultry clinic of Ahmadu Bello University, Zaria, Nigeria
No full textNewcastle disease (ND) is a highly contagious viral disease of domestic and wild birds with devastating impact on poultry health and production. Many vaccines and vaccination schedules are in use in controlling the disease but prevention and control are still a problem. A ten-year retrospective study (2002-2011) of Newcastle disease and other poultry diseases diagnosed at the Poultry Clinic of Ahmadu Bello University Veterinary Teaching Hospital (ABUVTH), Zaria, Kaduna, Nigeria was conducted. Out of 2,649 cases of poultry presented, 43.9% (1,164 cases) were confirmed as ND. The highest number of cases of the disease was in August followed by July and May. The cases of ND were observed to be higher in the rainy season (July to September), but it seems to be 1.43 times more likely to occur during pre-dry season (October to December). Most of the cases of ND were recorded in chickens and turkeys. Birds between the ages of 9 and 20 weeks were 2.01 times more likely to suffer from ND than younger birds. Most of the cases of ND were reported in birds that were vaccinated against ND than non-vaccinated ones. It was recommended that monitoring of Newcastle disease antibody titre should be intensified during rainy season and birds should be vaccinated against the disease as at when due.Keywords: Newcastle disease, Poultry, Seasonal distribution, Vaccine, Zari
Modelling particle transport in gas-oil-sand multiphase flows and its applications to production operations
No full textUse of Computational Fluid Dynamics Model for Evaluating Performance of High Pressure High Temperature Wells
No full textA Functional Networks Softsensor for Flowing Bottomhole Pressures and Temperatures in Multiphase Flow Production Wells
No full textPublic perception of climate change and its impact on health and environment in rural southwestern Nigeria
No full textEsther O Asekun-Olarinmoye,1 James O Bamidele,2 Olusola O Odu,2, Adenike I Olugbenga-Bello,3 Olugbenga L Abodurin,3 Wasiu O Adebimpe,1 Edward A Oladele,4 Adeleye A Adeomi,3 Oluwatosin A Adeoye,3 Ebenezer O Ojofeitimi31Department of Community Medicine, College of Health Sciences, Osun State University, Osogbo, Nigeria; 2Department of Community Medicine, College of Health Sciences, Ekiti State University, Ado Ekiti, Nigeria; 3Department of Community Medicine, College of Health Sciences, Faculty of Clinical Science, Ladoke Akintola University of Technology, Ogbomosho, Nigeria; 4SIDHAS Project, Family Health International, Abuja, NigeriaBackground: Climate change (CC) has received extensive media attention recently, and it is currently on the international public health agenda. A study of knowledge and attitudes to climate change, most especially from rural Nigerian communities, is important for developing adaptation strategies. This is a study of public perceptions of CC and its impact on health and environment in rural southwestern Nigeria.Methods: This was a community-based descriptive cross-sectional study of 1,019 rural respondents using a multistage sampling method. The research instrument used was a pretested, structured, interviewer-administered questionnaire. Data were analyzed using SPSS software. χ2, Cramér's V, and Kendall's τ-c statistics were employed in addition to fitting the data to a logistic regression model to explore associations found significant on bivariate analysis.Results: Mean age of respondents was 36.9 (±12.4) years. About 911 (89.4%) of respondents opined that there has been a change in climate in the last 10 years. Supernatural reasons were prominent among respondent-reported causes of CC. Identified risky behavior contributing to CC included smoking (10.7%), bush burning (33.4%), and tree felling (41.0%). Poor knowledge of causes but good knowledge of effects of CC were found in this study. About two-thirds of respondents had a positive attitude to causes of CC, while half had a positive attitude to the effects of CC. A significant association was found between educational status (P<0.001, Kendall's τ-c=-0.042), occupational status (P<0.01, Kendall's τ-c=0.088), and attitude to causes of CC. Further analysis using logistic regression showed that occupational status was significantly associated with likelihood of having a positive attitude, but educational status and marital status were not.Conclusion: Rural areas of Nigeria are vulnerable to the adverse effects of CC. Respondents' poor knowledge but positive attitude to CC calls for dissemination of adequate information on CC in sustained health-promotion programs.Keywords: climate change, global warming, public perception, rural child health, environmental effec
Assessment of Protective Potentials of Ficus Exasperata Leaf on Arsenate-Mediated Dyslipidemia and Oxidative Damage in Rat’s Brain
No full textThis study investigated the protective potentials of methanolic leaf extract of Ficus exasperata on sodium arsenate-mediated dyslipidemia and oxidative damage in the brain of rats. Twenty-eight rats were sorted into four groups containing seven rats each. Group A (control) received distilled water while 10 mg/kg bw of arsenic in form of sodium arsenate (As) was administered intraperitoneally to groups B, C and D. Group C and D were treated with oral administration of 100 mg/kg bw and 200 mg/kg bw of F. exasperata leaf respectively for 14 days. Arsenate administration resulted in dyslipidemia as shown by significant elevation (P<0.05) in total cholesterol, triglycerides, LDL-cholesterol and coronary heart disease risk ratio while it also reduced HDL-cholesterol in the rats. It also causes lipid peroxidation and oxidative damage in the brains of the rat with significant elevation of malondialdehyde level and decrease in levels of reduced glutathione, glutathione s-transferase, catalase and superoxide dismutase. Histology of the cortex region of brain of the rats treated with arsenate showed abnormal neuronal morphology with neuronal degeneration and necrosis. However, treatment with F. exasperata significantly reversed and attenuated the arsenatemediated biochemical alterations. We demonstrated in this study that F. exasperata leaf effectively protects against arsenate-induced dyslipidemia and oxidative damage in rat’s brain
Performance Evaluation of Wireline-Retrievable Downhole Chemical Injection System Used in HPHT Wells
No full text- …
