NUMERICAL SIMULATION OF OUTER DIE ANGLE OF EQUAL CHANNEL ANGULAR EXTRUSION PROCESS

The study of the simulation of effect of outer die angle in Equal Channel Angular Extrusion (ECAE) process was investigated. The simulation was carried out on 6063 aluminium alloy with a view to achieve ultra-fine grain structures. ADINA user interphase Version 8.6 (900 modes) was used for the simulation. The unextruded parameters of the 6063 aluminium alloy were used as input codes and some basic assumptions were made in designing the model on 2-Dimensional scale. The billet was meshed by dividing the vertical and horizontal geometry into 30 and 4 elements respectively. The die angle was varied from 0o to 90o and the simulation results were displayed. The results showed that the force of 27.5X106 N, 27.5X106 N, 27.6X106 N and 31.2 X106 N was required to deform when the outer die angle was 0o , 22.5o , 45o and 90o respectively. Also, the strains achieved were 0.61, 0.62, 0.66 and 0.69 respectively. Thus, highest force is required at 90o and the strain achieved at 0o is the lowest. Based on the results, it was recommended that it is more economical to extrude at an outer angle between 22.5o and 45o as a relatively higher effective strain will be induced

Security Risks Management in Selected Academic Libraries in Osun State, Nigeria

The survival of a library depends to a large extent on how secured its collections are. Security of collections constitutes a critical challenge facing academic libraries in Nigeria. It is against this background that this studyinvestigated the security risks management in selected academic libraries in Osun State, Nigeria. The study adopted a descriptive survey design of the ex-post facto type. The population of the study comprised 145 librarypersonnel and 14,317 registered library users in four selected academic libraries in Osun State while the sample size consisted of all the145 library personnel and 2% of the registered users to make a total of 432  respondents. Questionnaire and interview with the Chief Librarians of the selected academic libraries were the instruments used for data collection. Data were analysed using frequency distribution and percentages run using statistical package for social sciences (SPSS). The study established that the most prevalent security risks in the libraries included stealing/theft of library materials, mutilation of library materials, defacing,   misuse/mishandling of library materials, insect attack, fire outbreak and flood. It also established inadequate funding, shortage of staff/personnel, erratic power supply and lack of institutional security policy/disaster plan as some of the challenges confronting security management in the libraries. Based on the findings, recommendations were made towards improving security management in the libraries

Microstructural Characterization and Some Mechanical Behaviour of Low Manganese Austempered Ferritic Ductile Iron

This work studied the microstructural characterization and mechanical behavior of low manganese Austempered Ductile Iron (ADI), with a view to improve the properties of iron and to increase the areas of applications. Three sets of ductile iron of specified composition were machined from Y-blocks to tensile and hardness pieces. The samples were preheated at 350 0C for 1hr and austenitised at 900 0C for 1hr in salt bath furnace. The three sets of samples were immediately austempered in the austempering salt bath furnace at uniform austempering temperatures of 300 0C, 350 0C and 400 0C for 90, 120 and 150 minutes; each sample for each temperature window. All sets were prepared for metallographic examination; tensile and hardness tests were carried out. The results showed that maximum hardness, tensile and yield strength were obtained at austempering temperature of 350 0C and at 150 minutes. At 300 0C and 350 0C, it was noticed that the hardness and strength increase with austempering time. The optimum tensile strength was 1300 MPa at 350 0C after austempering for 150 minutes. In conclusion the austempering operation has a significant effect on the mechanical and microstructural properties of ADI

Identification and Characterization of Candida Species Isolated from Clinical Specimens in Illorin, Kwara State

Candida has been reported has one of the most prevailing yeast genera. Candida is of diverse species that are commonly leave on soil and in the mucosal surfaces of  genitourinary tract,  gastrointestinal tract, and the mouth of human and have ability to cause oral thrush or vaginal thrush. The incidence of Candida infections has dramatically increased in recent years due to a significant increase in cases like HIV/AIDS, cancer, diabetes mellitus, long time use of antibiotic and tissue transplant. It is a cross-sectional study involving patients diagnosed of Candidiasis. The aim of this study is to identify, characterize and determine the prevalence of Candida species isolated from clinical specimens in selected health care facilities in Ilorin, Kwara state, Nigeria using conventional methods such as CHROM agar Candida differential media and Germ tube test. Of the 232 isolates recovered from Sabouraud dextrose agar, sub-cultured on CHROM agar and tested for Germ Tube Test. C. albicans 131(56.5%), has the highest prevalence, non-albicans such as C. tropicalis has the prevalence of 36(15.5%), C. dubliniensis 27(11.6%), C. glabrata 14(6.0%), C. krusei 12(5.2%), there was mixed growth 7(3.0%) and 3(1.3%) did not grow on CHROM agar. Candida albicans is the most prevalence of Candida species isolate from clinical specimen in Ilorin, Nigeria in this study (56.5%) and C. albicans is also the most prevalence in Female (59.6%) while C. tropicalis has the highest prevalence in Male (36.8). Age group between 20 -29 has the highest prevalence (64.5%). Clinical specimens that produce highest number of Candida species in this study was High Vaginal Swab (58.2%) and pelvic inflammatory disease was the most clinical diagnosis (34.1%) and female subject has the highest prevalence of Candida infections (91.8%) while male has  (8.2%) in Ilorin, Nigeria. There was a statistical significant difference (P < 0.01) between age and Candida species distribution among participant

Study of the Performances of Nano-Case Treatment Cutting Tools on Carbon Steel Work Material during Turning Operation

The degree of holding temperature and time play a major role in nano-case treatment of cutting tools which immensely contributed to its performance during machining operation. The objective of this research work is to carryout comparative study of performance of nano-case treatment tools developed using low and medium carbon steel as work piece. Turning operation was carried out under two different categories with specific work piece on universal lathe machine using HSS cutting tools 100 mm x 12mm x 12mm that has been nano-case treated under varying conditions of temperatures and timeof 800,850, 900, 950oC and 60, 90, 120 mins respectively. The turning parameters used in evaluating this experiment were cutting speed of 270, 380 and 560mm/min, feed rate of 0.15, 0.20 and 0.25 mm/min, depth of cut of 2mm, work piece diameter of 25mm and rake angle of 7o each at three levels. The results of comparative study of their performances revealed that the timespent in the machining of low carbon steel material at a minimum temperature and time of800°C, 60 mins were1.50, 2.17 mins while at maximum temperature and time of 950°C , 120 mins were 1.19, 2.02 mins. It was also observed that at a corresponding constant speed of 270,380 and 560mm/min at higher temperature and time, a relative increased in the length of cut were observed. Critical observation of the result showed that at higher case hardening temperature and time (950°C/120mins), the HSS cutting tool gave a better performance as lesser time was consumed during the turning operation

The Prevalence, Effects, and Reactions to Use of Short Message Services in University Settings in South West Nigeria

This chapter focuses on the extent of the usage of Short Message Services (SMS) in three universities in Southwest Nigeria, with 243 participants drawn from Covenant University, Bells University, and Lagos State University, who responded to a questionnaire on SMS. Data generated from the study confirmed the high usage of SMS among subjects in general and males in particular, within the age range of 31 to 40 years; a large number of subjects, especially those in administrative positions, were affected by the usage of SMS; most of the subjects are more tolerant when the messages are related to religion, are work-related, or are from family members. Subjects expressed concern when the contents of the SMS are related to adverts, when SMS are used when there are network problems, and the possible exploitation of recipients. Steps to minimize the disadvantages of the use of SMS are discusse

CONTRIBUTORY ROLE OF INSTITUTIONAL, LEGAL AND ETHICAL FACTORS AS PRECURSORS OF CONSORTIUM BUILDING READINESS AMONG UNIVERSITY LIBRARIES IN SOUTHWESTERN NIGERIA

Consortium Building Readiness (CBR) is inevitable for university libraries that intend to provide adequate information resources and services to users. Preliminary investigations showed that efforts at CBR have not been successful in Nigeria. This may be as a result of the unpreparedness among university libraries to provide Institutional Factors–IF (Organisational Culture–OC, Organisational Policy–OP, finance, Power Supply–PS, Internet Connection–IC, ICT Literacy skills–ILS and digitisation), Legal Factors–LF (Governing Law–GL, Log-in-Option–LO, Non-disclosure of Log-in-Option–NDO, Dispute Resolution–DR, Cash Contribution–CC and dissolution) and Ethical Factors–EF (professional and business) to drive Consortium Building (CB). Little attention, however, has been paid to factors that could predict readiness for a successful CB among university libraries. This study therefore was carried out to investigate institutional, legal and ethical factors as precursors of CBR among university libraries in Southwestern Nigeria. Exchange and Resources Dependence, Social Exchange, Socio-Technical theories and Teamwork Model were used as the framework, while the survey design of the correlational type was adopted. All the 643 university library personnel in 45 university libraries in southwestern Nigeria were enumerated. The instruments used were Institutional Factors (α=0.75), Legal Factors (α=0.79), Ethical Factors (α=0.89), CBR (α=0.81) scales. Key informant interviews were conducted with nine selected university librarians. Quantitative data was analysed using descriptive statistics, Pearson product moment correlation and Multiple regression at 0.05 level of significance, while the qualitative data was thematically analysed. The IF, LF and EF jointly influenced CBR (R = 0.47; F(3; 545) =51.17; Adj. R2=0.22), contributing 22.0% of its variance. The business ethics (β=0.34), OC (β=0.33), GL (β=0.24), LO (β=0.24), finance (β=0.17), PS (β=0.10) and digitisation (β=0.07) relatively contributed to CBR. The university librarians complained that CBR was impossible due to lack of acceptable platform for all university libraries to disseminate and share resources. There were yearnings to come together as a team of consortium but finance and organisational commitment of their various institutions limited the move. Business ethics, organisational culture, governing law, log-in-option, finance, power supply and digitization and accessible platform level enhanced consortium building readiness among university libraries in southwestern Nigeria. These factors should be addressed to drive consortium building among them