Relationship between ultrasonic pulse velocity test result and concrete cube strength

This paper presents the findings of a study on the relationship between Ultrasonic Pulse Velocity (UPV) and Concrete Cube Strength; in three distinct stages. First, a preliminary investigation of the various properties of the materials used for the production of concrete was undertaken. This was followed by trial mix using a nominal mix of 1:2:4, water – cement, W/C, ratios of 0.4, 0.5 and 0.6; along with two different consolidation methods – manual and machine vibrated. Based on the result of trial mix, W/C ratio of 0.5 was used to prepare and cure 150mm x 150mm x 150mm concrete cubes. The third stage subjected the samples to UPV and destructive tests at the end of the following curing days: 1, 3, 7, 14, 21, 28, 56 and 90 days. Ultrasonic Pulse Velocity test result showed an inverse relationship (of -0.935) with the crushed concrete compressive strength. Correlation test, multiple regression analysis, graphs and visual inspection were used to analyze the results. The conclusion drawn is that there exists a relationship between UPV test results and compressive strength. It is expressed as follows: y = 151- 3.2x1; where y and x1 are compressive strength and UPV test results respectively. Hence it is recommended that the above formula can be used in converting the UPV test results to compressive strengthKeywords: Concrete, cube strength, non-destructive test, relationship, ultrasonic pulse velocit

P-Value, a true test of statistical significance? a cautionary note

While it’s not the intention of the founders of significance testing and hypothesis testing to have the two ideas intertwined as if they are complementary, the inconvenient marriage of the two practices into one coherent, convenient, incontrovertible and misinterpreted practice has dotted our standard statistics textbooks and medical journals. This paper examine factors contributing to this practice, traced the historical evolution ofthe Fisherian and Neyman-Pearsonian schools of hypothesis testing, exposed the fallacies and the uncommon ground and common grounds approach to the problem. Finally, it offers recommendations on what is to be done to remedy the situation

Knowledge Management Practice on Construction Project Performance in Nigeria

The study which was exploratory in nature evaluated the benefits of KM practice on construction project performance. A field survey was conducted with the use of structured questionnaires, self-administered to a sample of stakeholders in the built environment. Descriptive statistics was employed for the analysis. Results of the study have identified eight (8) value-adding KM factors as essential for obtaining KM benefits. Likewise, the results further indicated 19 benefits of KM practice for improving construction project performance and include: improve project quality, cost and time; practice and process improvement; encourage effective teamwork and innovation; improve the client satisfaction; boost productivity of employees and processes; enhanced organisational competence; higher levels of expertise and knowledge; enhanced employee capability and organization learning; risk minimisation; and improved decision-making, among others. The survey has systematically reviewed the scientific contributions of knowledge management practice that guide stakeholders on construction project performance. Moreover, the findings will assist government and other agencies in the adoption of KM practice in the Nigerian construction industry. It recommends that government and professional bodies should mandate the use of KM practice on construction project delivery for better performance.Keywords: Benefits, Construction project performance, Knowledge Management, Nigeria

Comparative reliability of ultrasonic pulse velocity and rebound hammer test methods in assessing compressive strength

This is an evaluation of the efficacy of the two most popular Non Destructive Testing (NDT) methods – Ultrasonic Pulse Velocity (UPV) and Rebound Hammer (RH) in assessing compressive strength of concrete. 150mmx150mmx150mm concrete cube samples were prepared, cured and subjected to UPV and RH tests at the end of : 1, 3, 7, 14, 21, 28, 56 and 90 days. The same samples were, then subjected to destructive (compressive strength) test. Correlation test, multiple regression analysis, graphs and visual inspection were used to analyze the data obtained. Results indicated increase in rebound hammer from 24 rebounds on the first day to 43 rebounds on the 90th day; while the result of UPV decreases from 43.10 Micro-Sec. on the first day, to 35.90 Micro-Sec. on the 90th day of curing. Regression Model which combines UPV with RH gave the following results: 10.93 N/mm2, 13.99 N/mm2, 25.23 N/mm2 29.72 N/mm2, 33.45 N/mm2, 33.32 N/mm2, 35.45 N/mm2 and 36.75N/mm2 for 1, 3, 14, 21, 28, 56 and 90 curing days, respectively. The conclusion drawn from the analysis, is that combination of rebound hammer and UPV methods is effective in assessing compressive strength of concrete. Hence it is recommended that for more accurate result, rebound hammer should be combined with UPV testing concrete, and that the following formula should be used = 45.80 + 0.88 X -1.31 X . 1 2Keywords: Concrete, Comparative study, compressive strength, rebound hammer, ultrasonic pulse velocit

Automation in Nigerian University Libraries: Mirage or Reality?

The trend in IT in the information society is that library automated systems are geared to function in the digital library environment. With this unprecedented success in library automation we would be able to organize and preserve our knowledge without fear of loss of access and maintain a single or central database for all the library subsystems. This paper has analyses the Nigeria’s ICT environment, current state of automation in Nigerian university libraries with particular reference to Ahmadu Bello University, Zaria and University of Ibadan Libraries and concludes by proposing a model for achieving automated library system in our universities for effective information access, management and delivery based on enormous benefits accruable to libraries that embraced the system. Key Words: ICTs, Library Automation, Nigerian Universities, University Librarie

Patterns of scholarly collaboration among academics in Nigerian universities: Knowledge sharing or knowledge hoarding?

This study investigates the patterns of scholarly collaboration among academic staff in the four Nigerian universities, Bayero University, Kano; University of Maiduguri; University of Ibadan; and University of Porthacourt, using quantitative approach through survey questionnaire administered randomly to collect data from the population of academics in the four universities. The study found that Nigerian university academics collaborate in the pursuit of their scholarly activities in the areas of publishing/writing article, data collection, data analysis, and workshops/seminar presentations. The findings also revealed that phones, emails, web forums/blogs/wikis, instant messaging service, Voice over IP (VoIP), social networking sites and post mail were the means of communicating research and other scholarly endeavors to colleagues, both within and outside their universities. The study will serves as a springboard for strengthening and facilitating scholarly collaborations and knowledge sharing, thereby bridging the knowledge gaps that exist between the haves and have not knowledge in the Nigerian higher education sub-sector. The contribution of the study lies in the fact that the findings add to the understanding of knowledge sharing activities available in the Nigerian universities, and no such study exists in the literature

Effects of Collaborative Learning on Chemistry Students’ Academic Achievement and Anxiety Level in Balancing Chemical Equations in Secondary School in Katsina Metropolis, Nigeria

The study investigated effects of Collaborative learning on Chemistry students’ academic achievement and Anxiety level in Balancing Chemical Equations in Secondary Schools in Katsina metropolis, Nigeria. The study sampled 80 SSII students, randomly selected from two senior secondary schools in katsina metropolis. The two schools were randomly placed as experimental and control groups each with 40 students. A quasi-experimental pretest-posttest research design was used for the study. The study subjects in the experimental group was taught/ allowed to learn using Collaborative learning concept of Balancing Chemical Equation, while the control group also was taught the same concept using traditional method for the period of six weeks. A chemistry Achievement test and Students Anxiety scale Questionnaire were used as the instruments for data collection. Performance of the two groups were compared using post-test mean scores, and t-test unrelated sample, at a significant level (P) =0.05. The findings from the study shows those students taught using Collaborative learning tent to achieve significantly higher and their anxiety was found to be low when compared with those taught using lecture method. Based on the findings, the recommendations were made among which; Chemistry teachers should always use Collaborative learning in teaching chemistry concepts, as this method enhance students achievement and reduce students anxiety

Antenatal care as a determinant of perinatal mortality in Nigeria: population-based study

Research Report Submitted To the Faculty of Humanities, University of the Witwatersrand Johannesburg, In Fulfilment of the Requirements for the Award of Degree of Masters of Arts in Demography and Population Studies Academic Year, 2014The World Health Organization has recommended focused antenatal care as a strategy for reducing the burden of perinatal mortality and for the overall improvement of maternal and child health. Fragmentary studies in Nigeria indicate that lack of ANC or inadequate ANC is a predictor of perinatal death. However, most of these studies are hospital-based and suffer heavily from selection bias and therefore do not adequately represent the general population. This study examined the association between focused antenatal care and perinatal mortality in Nigeria. Data Source and Methods The data for this study comes from the 2013 Nigeria Demographic and Health Survey (DHS). The 2013 Nigeria DHS is the fifth round of nation-wide organized data collection system supported by USAID and implemented by the National Population Commission (NPC 2014). The 2013 survey consists of nationally representative sample of 38,945 women aged 15- 49years and 17,359 men aged 15-59 years living in 38,904 households. The unique feature of the 2013 survey is the collection of information that allows the estimation of perinatal mortality possible. The main outcome variables are stillbirth (death of fetus after 7months of pregnancy or 22weeks of gestation), early neonatal death (death within 6days of delivery) and perinatal mortality (sum of stillbirths and early neonatal death). The main exposure variable is having at least four antenatal care visits in the most recent pregnancy within the five year period preceding the survey as recommended by WHO. Cox proportional hazard models were fitted to answer the research question. Results There were 396 stillbirths and 925 early neonatal deaths and use of focused ANC is 61%; perinatal mortality rate as a whole is 41 per 1000 births. About 29% of all the early neonatal deaths occurred on the day they were born while 61% within 48 hours of delivery. Use of ANC varies significantly with maternal age, geopolitical zone (North/South), place of residence (rural/urban), maternal education, wealth index, religion, and parity, sex of household head, marital status and type of marriage (polygyny/monogamy). Further, perinatal mortality rate vary according to some previously established trends: more at the extremes of maternal ages, higher in northern than in the southern geopolitical zone, highest among those with primary level of education and among lowest wealth quintile; among parity one and five or more, male child, very small babies and small babies (<2.5Kg) and those delivered in health facility. In the final model, factors significantly reducing the risk of perinatal mortality are use of focused ANC (HR=0.69, 95%CI: 0.65-0.73); being in the middle or rich wealth quintile (HR=0.87, 95%CI: 0.83-0.92); living in southern zone of the country (HR=0.87, 95%CI: 0.84- 0.89); being of parity between two and four (HR=0.91, 95%CI: 0.83-0.99); having had a urine test (HR=0.86, 95%CI: 0.81-0.91) and receiving all the six components of antenatal care (HR=0.18, 95%CI: 0.13-0.25). Those factors found to increase the risk perinatal death include living in rural area of the country (HR=1.32, 95%CI: 1.27-1.38); having between one and three cowives (HR=1.21, 95%CI: 1.17-1.26) having had a complication during the pregnancy (HR= 1.20, 95%CI: 1.16-1.25); having a female as the head of the household (HR=1.05, 95%CI: 1.02- 1.09) and taking iron tablets for more than six months (HR=1.24, 95%CI: 1.15-1.34). Conclusion The results of the analysis show that use of focused ANC significantly reduces the risk of perinatal mortality by about 31%; varying between 26% (risk reduction for early neonatal death) and 28% (risk reduction for stillbirths). Other factors that are significantly associated with reduction of perinatal mortality are residing in Southern part of the country, being of parity of between two and four, being in the middle and/or rich wealth quintile, having had a urine test during ANC visits and receiving all the six elements of antenatal care. Policy implication This results calls for the more investment in maternal and child health services particularly antenatal care to make it more easily accessible in the overall framework of improving maternal and child health. It specifically implies that socioeconomic development programs should target basic schooling (especially female education), economic welfare/poverty eradication, women empowerment as well as allocating more health resources in the disadvantaged rural areas and Northern part of Nigeria. Research implication While this research has corroborated the recommendations of WHO it has also opened up new areas of future research. There is the need to test the validity of World Health Organization’s recommendations on the role of focused ANC on perinatal mortality using more advanced statistical methods and designs such multi-level modelling, instrumental variable and propensity score matching. To have a smooth transition from research to practice, operations research have to be conducted in specific cultural and health systems contexts to deal with issues specific to these contexts. Such operations research will involve assessing the capacity of the health system on how to implement the new model of ANC in terms infrastructure, staffing, training and re-training of staff and supplies. Attitudes and perception of providers and clients about the new model needs to be determined also. It is also important to conduct a multicountry analysis to assess the claim of WHO knowing fully that WHO conducted the trial of this model in only four countries none of which is from sub-Saharan Africa

Value Management Concept in Construction Projects Delivery in Kano State

Construction projects delivery play an important role in the economic development of any nation. Nevertheless, review of project documents in Nigeria and Kano State in particular indicates that, the design of these projects is such that the whole life-value is not achieved. One of the suitable tools for the compensation of this drawback is the use of Value Management (VM) technique. This paper presents that the use of organized framework for the VM technique in the initial phase of a project generates good ideas that has the capacity to increase the project value. The objective of the study is to investigate the application of the VM in public construction projects, identify the constraint factors limiting its application, and suggest ways to expand its use in the built environment. Questionnaire survey methodology, addressed to government ministries and agencies actively involved in construction and to project management consulting firms, was utilized. A total of 94 questionnaires responses were received from 7 ministries and agencies. Another 13 responses were received from randomly selected consulting firms. The data was analyzed using SPSS 23 version. &nbsp;It was found that value management as a formal programme is not applied to the development of construction projects in Kano State. Lack of knowledge about the value management technique and its financial and technical benefits was found to be among the constraint factors of its application. Furthermore, lack of government demand on VM, unfamiliarity with VM technique, and unavailability of experts to perform were determined to be the top constraint factors. Therefore, it is recommended that the promotion of value management use can be achieved by creating awareness among the construction stakeholders, gaining top management support, providing training programmes, guideline, and financial incentives to procurement administrators

Knowledge sharing and dissemination among academics in Nigerian universities: Patterns and trends

The paper investigates the phenomenon of knowledge sharing among academic staff in the four Nigerian universities, namely Bayero University, Kano; University of Maiduguri; University of Ibadan; and University of Porthacourt. The quantitative approach was used in the study to randomly administer questionnaire on three hundred and sixty four (364) academic staff in the four universities. The study found the evidence of knowledge sharing among academics in the four universities through workshops, seminars and conferences, membership of professional associations/societies and readiness to share knowledge and other resources with colleagues. The study serves as springboard for universities and their lecturers in Nigeria to reevaluate and re-strategise the present scenario, particularly regarding use of modern technologies to increase awareness, communication and networking for improved research and teaching activities, since knowledge sharing is a critical factor in the survival of educational institutions across the globe