EXPERIMENTAL INVESTIGATION OF THE POTENTIAL OF LIQUIFIED PETROLEUM GAS IN VAPOUR COMPRESSION REFRIGERATION SYSTEM

The essence of refrigeration systems cannot be overemphasized especially in this part of the globe. Perishable items are to be preserved for some periods before usage while human comfort should also be also be paramount since we are in the northern hemisphere of the globe. The device hat doe this uses refrigerants as working fluids which are traditional harmful to human beings through depletion of the ozone layer. Majorly Ozone layer protects the earth from warming which could lead to flooding. Common economical refrigerants like CFCs (Chlorofluorocarbons) have been discovered to be harmful to the earth. This article therefore, experimented the quantity replacement of CFCs with Liquefied Petroleum Gas in various mixes. The LPG (Liquefied Petroleum Gas) used consists a mixture of propane and butane in the ratio 6:4 by mass. The blend of the two refrigerants were shaped essentially by blending at least two single-part refrigerants, the GWP (Global Warming Potentials) of a refrigerant mix is the mass-weighted normal of GWPs of individual parts in the mix. That is, to compute the GWP of a mix, one essentially adds the GWP of the singular parts with respect to their (GWP (LPG) x M (LPG)) + (GWP(R-134a) x M(R-134a)) = GWP (blend). From the evaluated GWP of the 6 different % mass composition, the % mass of (100%/0%) was the only refrigerant to adhere to the preferred GWP<150. The mass composition of blend (100%/0%) LPG/R-134a was first performed. In-order to achieve this, 8kg of each of the refrigerant was used. The blend was formed in an empty cylinder which was measured as 2482g with the aid of a digital beam balance, by gradually injecting LPG into the empty cylinder till the mass percentage of the 2000g entered, making the mass read as 4,482g (i.e., 2482g of the empty cylinder + 2000g of LPG). Based on the above observations, it could be inferred that the COP (Coefficient of Performance) of mixed refrigerants blends was higher than that of R-134a indicating that each of the blend exhibit higher performance. The experiment discovered that LPG could be used in the place of R134a without affecting the operation efficiency of a vapor compression refrigeration system. The study concludes that LPG offers the best alternative when the COP and flammability are combined as performance metric

Development of a Proactive Fault Diagnosis for Critical System

Large-scale network environments, such as the Internet, are characterized by the presence of various devices connected at various remote locations. There is a scenario of main office connected to different branch offices in another town and cities, with the presence of central administrative system at the main office. Any problem at branches is reported to the main office, due to availability of enough resources there. However, few support tools have been developed to allow the administrators at the central office to remotely control and monitor the computers at the branches. Even, in local area network environment, diagnosing the computers on the network is always a big problem for the administrator, as he/she moves from one computer to another, running the diagnostic program and collecting report for each machine tested. This is strenuous and time consuming. To help address these problems, I have employed the concept of mobile agent to design an architecture that can remotely perform various checks and tests on computers on network, and report its findings to the server administrator as central location. This architecture was implemented with Java, using Jini lookup service to establish communication between the computers. The agent tasks were implemented in C programming language. The result of this research work shows that the use of mobile agent for remote maintenance of computers on network was found to provide an improved, efficient, and dynamic diagnostic management system. All the same, it has proven to be a substantive contributor to efficient network management

A rare metastatic region of cervical cancer; the brain: a case report

Cervical cancer metastasizes commonly to the bone, lungs, liver and the supraclavicular lymph nodes. Rare sites of metastasis the brain, breast, paraspinal muscles, duodenum and heart have been reported. Case report: A 53-year-old postmenopausal woman presented to our facility with a one-month history of vaginal bleeding. She was found to have an exophytic cervical mass on pelvic examination. She was managed as a case of stage IIIB cervical cancer. Histology revealed Squamous Cell Carcinoma type. She had radiotherapy and was symptoms free. She represented 3 months later with visual disturbance, headache and vomiting. She was found to have metastatic lesion to her brain. She survived for 3 months and 3weeks after first treatment. Conclusion: The prognosis of cervical cancer patients with brain metastases is frequently poor with median survival of only a few months such as in this case who survived 3 months and 3 weeks after first treatment. Only few reports have incidences of long-term, disease-free survival in these patients

EFFECTS OF COMPENSATION PRACTICES ON ACADEMIC STAFF’S JOB PERFORMANCE IN FEDERAL UNIVERSITY OF AGRICULTURE, ABEOKUTA, OGUN STATE, NIGERIA

The study examined the effect of compensation practices on academic staff’s job performance in Federal University of Agriculture, Abeokuta, Ogun State, Nigeria. Multi stage sampling technique was used to purposively select 3 Agricultural base colleges followed by proportionate stratified sampling technique where respondents were randomly selected. One hundred and three (103) respondents from the three colleges of agriculture of the university were selected of which 92 questionnaires were retrieved. Data obtained was analyzed using descriptive and inferential statistics such as mean, standard deviation, chi-square and Pearson Product Moment Correlation. Finding revealed that the mean age of the respondents was 42.71 years, 71.7% of the respondents were male, 81.5% of them were married and 79.3% of the respondents were PhD holders. The mean years of experience was 10 years while their mean income was ₦217447.29. Most (79.4%) academic staff perceived that there is a pressing need to review and rationalize the pay structure to improve employee efficiency, some of the compensation packages available were; retirement benefit (100%), study leave (91.3%), career development opportunity (82.6%). The major constraints to compensation strategies identified were poor insurance scheme (21.7%), inadequate welfare package (20.7%) and poor communication network (19.6%). Furthermore, a significant relationship existed between respondents’ age (r= -0.204, P<0.05), compensation packages (r= 0.26, P<0.05) and their job performance. The results concluded that academic staff perceived a pressing need to review the compensation packages by involving them in the compensation decision making process. Effective management and implementation of compensation packages is highly recommended. , , Job Performanc

PERCEIVED EFFECT OF COACHING AND MENTORING ON EMPLOYEE JOB PERFORMANCE AMONG ACADEMIC STAFF IN UNIVERSITY OF IBADAN, OYO STATE, NIGERIA

The study assessed the effect of coaching and monitoring on employees’ job performance among academic staff in University of Ibadan, Oyo State, Nigeria. Multistage sampling technique was used in obtaining data from ninety academic employees of Faculty of Agriculture University of Ibadan for the study. The data was analysed using Chi square and Pearson Product Moment Correlation. The mean age of the respondents was 51years while 66.3% were between ages 51-70 years, 52.3% were female and 50.2% were married. The average year of experience of the respondents was 18.1 years while majority (79.1%) of the respondents has obtained their PhD degree. On challenges facing coaching and mentoring, respondents identified mentee unwillingness to be mentored (x̅=2.84), and non conducive environment for coaching and mentoring (x̅=2.67) as the major constraints, while the least constraint was time and workload pressure (x̅=2.03). Many (62.1%) of the respondents have high job performance level. There was significant relationship between respondents’ marital status and job performance (P≤0.05). The study concluded that coaching and mentoring influence employees’ job performance positively among academic staff in academic institutions and recommended that provision of good work-environment for coaching and mentoring of academic staff should be provided by university management.   &nbsp

Activities of a Cellulase of the Termite, Ametermes Eveuncifer (Silverstri) Soldier: Clue to Termites Salt Intolerance

Table salt which contains predominantly NaCl is both toxic and lethal to termites and is therefore used to control the insect traditionally. In an attempt to find out a scientific explanation for this treatment and possibly design a pesticide for the destructive insect, we carried out some tests on the effects of NaCl (table salt), some other chloride and sodium salts on some important enzymes produced by termites. At 0.1mM concentration, all the chloride salts inhibited all the enzymes. Acid phosphatase and arginase were however mildly inhibited. Interestingly, some chloride salts were more potent than NaCl the conventional pesticide.  The greatest inhibition was by the chlorides of mercury (81%), manganese (78%), and sodium (76%). The inhibitory effect was more on cellulolytic enzymes; β-glucosidase and cellulase than on detoxifying enzymes; 3-MST and rhodanese. Again, all the sodium salts tested inhibited cellulase drastically with most of them more potent than NaCl. Thus both the sodium and chloride ions contributed immensely to the inhibition. Form these discoveries, one of the chloride salts of mercury, manganese and sodium or a combination of at least two can be used as a pesticide for termites. Almost all the sodium salts tested or a combination of at least two can also be used. Keywords: cellulase, cellulose, termites, salts, insects, enzyme

Comparative Analysis of Selected Animal and Vegetable Oils Suitability in Machining of Plain Carbon Steels

Due to the alarming rate in public awareness on environmental issues, there has been growing demand for biodegradable materials which has opened an avenue for using vegetable and animal oils as alternatives to petroleumbased polymeric materials in the market, most especially in machining operations. Thus, research on biodegradable functional fluids has emerged as one of the top priorities in lubrication, due to their applicability in many diverse areas. In this quest, there is need to conduct machining trials to determine the suitability of these oils in metal cutting (turning) operations of plain carbon steels. This study investigate the effect of the selected cutting fluids on certain parameters like machine removal rate (MRR), machining time, tool wear and spindle power consumption, etc. under different machining combination in turning operations of plain carbon steels obtained from universal steel Ikeja, Nigeria, using 150 x 10 HSS cutting tool. The selected oils purchased from Ogunpa market in Ibadan, Nigeria, were sieved to remove any foreign particles or dirt. The solution; water, based-oil, and emulsifier (to allow thorough mixing of water and oil without separation), were mix at an elevated temperature of 550C in a proportion 4:1:3. Experimental results clearly showed that Conventional cutting fluid might be replaced with Non-conventional cutting fluids (vegetable and animal based) as they give better performance. With slight modifications and deliberate but careful alterations in some of the components of such oils, even better performing cutting fluids could be obtained.Self-sponsore

Optimization of Absorber Layer and Operating Temperature of Copper Indium Gallium Selenide Solar Cells Using Different Metal Contacts

Device simulation was employed to investigate the effect of metal back contact electrodes on the performance of n-type CdS/p-CIGS thin film solar cells using varying thicknesses of absorber layer at operating temperature of 300K. The effect of working temperatures was also studied from 300K to 400K in steps of 10K. The simulations were carried out using standard solar cell capacitance simulator (SCAPS) 3.3.03 version software. The results showed better efficiencies at the optimized thickness of 3µm for all the back contact electrodes under study. The maximum efficiencies of 17.5 %, 15.5 %, 11.5 %, 3.5 % and 3 % were estimated for CIGS thin film solar cell at 300 K for platinum, gold, cobalt, silver and copper back contact electrodes respectively. The efficiency decreases as the operating temperatures increases from 300 K to 400 K. It is recommended that the optimized thickness of 3 µm is appropriate as absorber layer for efficient and cost effective CIGS thin film solar cells for economic reasons

Combining ability studies in tropical sorghum (Sorghum bicolor (L.) Moench)

Sorghum varieties grown in West Africa usually have low production potential. Information on combining ability of diverse open-pollinated cultivars and gene pools is needed for efficient choice of breeding methods and parental materials to use in developing breeding programs to increase production. Twenty parental lines including 15 restorers and 5 male-sterile A-lines were mated. The 20 parents were sampled from elite germplasm available for cultivar development in the region. Combining ability studies were conducted on these parents along with their F1 hybrids for grain yield, days to anthesis, plant height, inflorescence length, threshing percentage, and seed mass in 2 years and in two locations. Each location-year combination was considered as an environment. For each trait, general combining ability (GCA) and specific combining ability (SCA) effects were estimated using the line-tester method of analysis. Highly significant GCA effects of males were found for all traits under study. Significant SCA was detected in all traits except inflorescence length. From the ratio of general combining ability to specific combining ability non-additive gene action was predominant for most traits. Parental lines with good performance per se and good performance in crosses for most agronomic traits included: ICSA 902 NG, NR 71182-2, NR 71182-3, CS 144, and Damougari. Both additive and non-additive gene effects are involved in variations observed among crosses. Hybrid breeding could contribute to sorghum improvement in the dry land agriculture of West Africa. Importance of genotype-environment interaction underlines the necessity of evaluating breeding materials under broad range of conditions. The various traits studied can be improved through breeding procedures using a range of different intra-population and inter-population selection procedures. In hybrid breeding procedures, testing of parent lines for general combining ability should be supplemented by evaluation of individual F1 hybrids for specific combining ability

Occurrence of Similar Periods in Geomagnetic Field Variations and Solar Activity

The periodicities associated with some geomagnetic field parameters under quiet and disturbed solar conditions have been examined using a set of data spanning through five years obtained courtesy of INTERMAGNET network. Hourly values of the Horizontal component of the geomagnetic field simultaneously obtained at seven INTERMAGNET stations were engaged in the study. The stations were well distributed across the latitudes, viz: Bangui, 4.4°N; Kourou, 5.1°N; Alibag, 18.6°N; San Juan18.1°N; Crozet, 46.4°S; Barrow, 71.3°N; Scott  Base, 77.9°S). Solar quiet daily variation Sq, Superposed Magnetic field SPMF and Solar disturbance daily variation SD in the horizontal magnetic field component were evaluated and studied for their spectral characteristics. The spectral analysis revealed the periods of 6 hours, 12 hours, 24 hours, 3 months, 6 months, 12 months and 16 months in the geomagnetic field variations. The observed periodicities were explained in terms of associated solar terrestrial processes. This clearly shows the influence of an extra terrestrial source (the Sun) on terrestrial processes. Sun is the undisputable driver of space weathe