Archives-February 2019

The valorization of minerals requires physicochemical and thermal treatments, using various materials such as crucibles. They are refractory ceramics mainly based on clays. Crucibles must be resistant to chemical aggression by molten slag and metals at high temperature during repeated thermal cycles, to ensure the durability in use. Fire-assaying is extensively used in gold mining in Burkina Faso, needing a huge quantity of ceramic crucibles imported per year. In this study, we have characterized different clays to manufacture refractory ceramics for crucibles. Physical characteristics of laboratory made crucibles were compared to that of industrial crucibles. The behavior of an optimized composition with 25wt% of clay and 75wt% of chamotte (fired clay) was experimented to optimize the properties in use. Particularly, the adequate adjustment of all process parameters, as the paste plasticity, leads the control of the density and porosity of the fired ceramic. Fusion tests with copper and aluminum at temperature between 600°C and 1100°C proved the small penetration depth of the molten metal into the ceramic that reduce the corrosion phenomenon. Our work evidences the existence of both a scientific and a technological knowledge in the use of silico-aluminate mineral resources from Burkina Faso, for manufacturing refractory crucibles for the melting of both slag and precious metals.

We report the case of spinal cord compression from pathological fractures of the vertebral bodies with Gammapathy monoclonal in conjunction with multiple myeloma in a 52-year-old man who had recently been examined for paraplegia after two weeks of full pain. In our kwnoledge we thing that is a rare condition and must mainly been reported as a case presentation in the literature.

The study sought to know how Library and Social Media serve as a facilitator for national unity and security in Nigeria. The study adopted a correlational research design with a population of 3,840 comprising of students and lecturers of different levels. A random sampling technique was adopted and Krejcie and Morgan method was used to determine the sample size of 350. The instrument used was tagged “Library and Social Media as a Facilitator for National Unity and Security (LSMFNUSQ)”. The instrument was validated by five experts and a field trial of test retest was done to know the internal consistency which yielded 0.79 co-efficient. 350 copies of questionnaire items were face-to-face administered to the respondents and 200 successfully retrieved. Mean statistics was used to analyse the research questions and Pearson Product Moment Correlation (r) was adopted to test the hypotheses. The study noted that Library and Social Media played a high level of role towards national unity and security. Among other things, the study recommended that there is need as an issue of priority to establish more public and school libraries which will help cultivate reading habits among youth and adults. Books on security issues should be stocked in the libraries for users

This study adopted a correlational research design to find out the relationship between the roles of Library and Information Science (LIS) Education and the 21st Century Information Users in Nigeria. The study covered six higher institutions with twelve Departments and a population of 2, 400 year 1 and National Diploma I students. A researcher-designed instrument and four point scale was used. 331 was the sample size using Krejcie and Morgan sampling method of determining the sample of a known population. Mean statistics was used to answer the research question and Pearson Product Moment Correlation adopted in analysing the hypothesis. The study discovered that LIS education played high level of roles for the 21st century information users in Nigeria. Among other things, it was recommended that government should formulate a workable policy that will see that students are introduced to the use of library education from the Nursery, Primary and Secondary school levels.

Direct gamma spectrometry study was carried out within the Adenta municipality in the greater Accra Region of Ghana to ascertain a baseline radioactivity levels of naturally occurring radioactive materials in borehole water at the Adenta Municipality. The average activity concentrations of 226Ra, 232Th and 40K in twenty boreholes were measured. The activity concentration of 226Ra, 232Th and 40K in the samples ranged from0.27 ±0.05Bq/L to 1.83 ±0.55Bq/L, 0.11±0.06Bq/L to 4.29±0.27Bq/L and 1.24 ±0.16Bq/L to 28.75 ±4.82Bq/L respectively. The average activity concentration values were 0.77±0.42, 0.93±0.62 and 9.77±4.55 Bq/L respectively. The total committed annual effective doses due to intake of natural radionuclides in the borehole water was estimated to be 40.29±48.82µSv/yr, which is far below the World Health Organization recommendation limit of 100µSv/yr. However, four of the boreholes exceeded the WHO recommended limit for total committed annual effective dose. The results obtained in this study shows that some of the inhabitants in Adenta municipality were expose to a significant radiological health hazards due to drinking water from the boreholes in the municipality. The results from this study will serve as a baseline data for future research in the study area.

In many developing countries, it is estimated that 60% of project management professionals appear to pay less attention to project success factors of timely completion, budget fidelity, and high quality, considered the critical success factors for successful completion of construction initiatives and projects. The purpose of this correlational study was to examine the relationship between project budget and the independent variables of time and in the Greater Accra Region of Ghana, in Africa. The theories of iron triangle, scientific management, and strategic management represented the theoretical underpinning and constituted the theoretical framework for this study. In this study, one hundred and sixteen project managers were randomly selected from the population of construction professionals in the Greater Accra Region of Ghana. The project managers recruited for this study, completed the survey entitled the Six Key Performance Indicators developed by Ngacho and Das (2014). The results of this study involving multiple linear regression analysis, indicated that a weak positive correlation exists between the independent variables (time and quality) and project budget, F(1, 114) = 37.08, p < 0.001. Time recorded the highest beta (? = .50) and quality (? = .06). Attention to key the project management performance indicator of time could improve project outcomes in the Ghanaian construction sector. From a social welfare and positive change standpoint, this study findings could be useful to improve the quality of projects and the knowledge from it in some way could contribute to ameliorating the lives of project management professionals and community members in the area.

Scientists all over the world have been concern for the earth due to the effect of climate change that has now become a matter of discuss. The effect of climate change is not only limited to several natural disasters such as Tsunami, melting of ice Berge, high rise water bodies etc. It has been agreed that mitigating the effect of climate change can be achieved through reforestation and replanting of trees in the forest. To ensure that climate change is mitigated holistically, all hand must be on deck. As such implementing the use of treated wood to forestall needless replacement of wood due to failure resulting from fungi decay and insect attack is another practical approach to ensure that the forest the major player in mitigating climate change is kept intact. It is therefore recommended that government policy should include ensuring that wood meant for building construction is given necessary treatment before installation to safeguard the integrity of the forest.

The psychophysiological influence of the virtual reality on a human has already been under discussion for a long time. There is an empirical correlation of immersion with hardware and software parameters of the virtual reality such as a frame rate, tracking a head rotation, audio, and interaction methods applied in the virtual reality. On the other side, a deep level of interaction can be explained by activation of similar cognitive structures in the brain and sensory stimuli as in same situation on practice. In this perspective, psychophysiological test is simple model of human activity and could be provided benefit to measuring of performance man-machine interaction with graphic monitor (desktop application) and head-mounted display (in virtual reality). Its key idea is to measuring of human performance in different environments (desktop and virtual reality) by the test for a reaction rate to a movable object with feedback and without. It was shown that effectiveness of man-machine interaction turns out to be higher when using head-mounted display (in virtual reality) than when using a video display (desktop application) independently on the different orders of performing the testing tasks. The data obtained could be provided benefit to modeling training systems in virtual reality and for improving learning performance. The material presented can open new prospects for further research studies. It seems interesting to those who work in the field of usability engineering, training simulation and human-computer interaction.

Table of contents for the month of February 2019