MACHINE LEARNING APPLICATIONS IN COMPUTER INTEGRATED MATERIAL DESIGN AND MODELING

This research seeks to develop and test a framework for considering Inductive Hierarchical Analysis (IHA) using Machine Learning (ML) technique in a multistage material design of a gear manufacturing process. A ML model was developed, which implements Random Forest (RF) regression algorithm together with analysis of variance (ANOVA) approach for mapping sets of material and product design variables, thus classifying the design space into feasible and non-feasible solution space. This approach is applied to the design of steel gear within specified performance requirements by exploring the design space for the Process-Structure-Property-Performance (PSPP) relation in the hot rolling process. With an objective of how machine learning models can be incorporated into the material design and modeling for predicting the material properties of steel used for gear manufacturing, a working hypothesis was outlined, and tasks for accomplishing this objective was developed. Feasible solution space was derived by the RF approach across the PSPP chain for the gear design by considering forward and inverse mapping. For the forward process, feasible range set of 84.68 - 84.9 and 32.54 - 32.84 was mapped at the structural stage to give feasibility range of 193.169 - 193.1818 at the property stage and eventually a feasibility range of 1.578 - 1.676 for the performance stage. The feasibility range was used as an input for the inductive process to generate feasible region of 193.171 - 193.174 at the property stage, 32.61 - 32.69 and 84.41 - 84.70 at the structural stage, while a feasible range of 1340 - 1360K evolved at the processing stage. The inverse process shows propagated reduction in variable size across the PSPP linkage with a Root Mean Square Error value of . This indicates a negligible error propagation across the modeling analysis and shows the robustness of RF as an ensemble of multiple decision trees. To further test the developed model, a predictive analysis of the Time-Temperature Transformation (TTT) curve was carried out by implementing Monte Carlo simulations together with the RF algorithm. This method accurately predicts the TTT curve with an accuracy matrix of 92.7%. The application of Monte Carlo helps to increase the robustness of the RF model by generating more input data points. This research work was extended to model the constitutive behavior of a flexinol wire to incorporate Artificial Intelligence (AI) with Finite Element Methods (FEM) as a way validating the approaching methods in this research. Being able to implement machine learning applications to computer integrated material design and modeling presents a novel approach to material design by using RF method. This broadens the knowledge base in material design processing and opens up opportunities for further research with the application of RF to material design. In addition, this research will help in bridging the gap and timeline in meeting customer’s performance requirements by serving as a tool for designing materials that are feasible with optimum performance capability for any engineering need

Structural Integrity of Functionally Graded Composite Structure using Mindlin-Type Finite Elements.

In this paper, two new Mindlin-type plate bending elements have been derived for the modelling of functionally graded plate subjected to various loading conditions such as tensile loading, in-plane bending and out-of-plane bending. The properties of the first Mindlin-type element (i.e. Average Mindlin element) are computed by using an average fibre distribution technique which averages the macro-mechanical properties over each element. The properties of the second Mindlin-type element (i.e. Smooth Mindlin element) are computed by using a smooth fibre distribution technique, which directly uses the macro-mechanical properties at Gaussian quadrature points of each element. There were two types of non-linearity considered in the modelling of the plate, which include finite strain and material degradation. The composite plate considered in this paper is functionally graded in the longitudinal direction only, but the FE code developed is capable of analysing composite plates with functional gradation in transverse and radial direction as well. This study was able to show that the structural integrity enhancement and strength maximisation of composite structures are achievable through functional gradation of material properties over the structure

DRUG ABUSE AND ITS ACADEMIC IMPLICATIONS AMONG STUDENTS AT THREE SECONDARY SCHOOLS IN MUTASA CENTRAL AREA OF MUTASA DISTRICT

This project explored the occurrence of drug abuse and its academic implications to students at three secondary schools in Mutasa Central area in Mutasa District. The study used the mixed method research design which combines qualitative and quantitative approaches in one study to answer research questions. The study population for this research comprised 48 secondary school teachers, 3 school heads and 150 students. Random sampling was employed to select the sample for classes within each form. Simple random sampling was used to select 8 senior school prefects for focus group discussions. School heads were selected for the study through purposive sampling for interviews. The main findings were that teachers did not teach anything about drug use during lessons as they concentrated on their subject content. They had some experience in dealing with drug problems in the schools. The main reasons why students took drugs was influence of peer pressure and lack of models at home. The most common drugs taken by students were tobacco and beer obtained from friends and road side markets. Schools experienced conflicts between teachers and students and students performed poorly in examinations as a result of drug abuse in schools. The main recommendations were made were that the Ministry of Primary and Secondary Education must formalize and support establishment of vibrant guidance and counselling system in schools and school administrators must establish vibrant guidance and counselling departments which effected individual and peer counselling. Teachers should incorporate drug education in the teaching-learning of other subjects and schools should invite guest speakers to address students on danger of drug abuse

IMPACT OF TEAM WORK ON TERTIARY INSTITUTION PERFORMANCE: A STUDY OF SELECTED COLLEGES IN FUNAAB

Successful teamwork is being recognized as a necessity for many aspects of effective administrative assignments and team-leadership has proved effective in improving team performance. Using two management-related colleges of Federal University of Agriculture, Abeokuta (FUNAAB) as organization of study, ninety respondents were sampled through the use of questionnaire. It was concluded after analysis that the practice of team-working is and should be embraced by corporate organizations, especially tertiary institution i.e. the more collectively engaged staff members are, the better the outcomes for the organization generally. Likewise it was also concluded that working in well-structured teams with an effective team-leader is a predictors of both individual and collective performance. The recommendation among others was that other institutions (private/ public) in the education sector should emulate the FUNAAB team-working initiative in order to continually and effectively meet their corporate obligations. Keywords:, , &nbsp

On the Generalized Pareto Probability Density Function of the Mean Annual Rainfall of Katsina State

This work was accomplished to assess the rainfall probability density function (pdf) of Katsina State and adopt the most parsimonious density function using 2003 – 2018 rainfall data from the Nigeria Institute of Meteorological Services. The data were subjected to cleaning, descriptive statistics and investigation of five distribution functions (General pareto, general extreme value, Gumbel maximum, Uniform and Normal distribution) through parameterizations. The results intimated that Daura experienced the highest mean annual rainfall ranging between 75.667 mm for 2003 and 82.417 mm for 2018. Both Dutsin-Ma and Safana local Government returned the least mean annual rainfall alternately and it ranged between 57.500 mm (2009 rainfall for Dutsin-Ma) and 67.167 mm for 2018 mean annual rainfall of Safana.  The order of performance of the five (5) prominent pdf in each of the sites differs but the Generalized Pareto distribution (GPD) ranked highest across all the sites. The distribution characteristics for the GPD (the most parsimonious of the pdf) are, mean = 61.15098 (Duara), 58.93371 (Dutsinma) and 79.20851 (Safana) and variance of 9212.603 (Duara), 6709.908 (Dutsinma) and 6687.102 (Safana).  The examination of the visual analysis of the residuals of the mean annual rainfall indicated that only the mean rainfall for Dutsin-Ma gave the most precise parameter estimates

Critical factors for insolvency prediction: Towards a theoretical model for the construction industry

© 2016 Informa UK Limited, trading as Taylor & Francis Group. Many construction industry insolvency prediction model (CI-IPM) studies have arbitrarily employed or simply adopted from previous studies different insolvency factors, without justification, leading to poorly performing CI-IPMs. This is due to the absence of a framework for selection of relevant factors. To identify the most important insolvency factors for a high-performance CI-IPM, this study used three approaches. Firstly, systematic review was used to identify all existing factors. Secondly, frequency of factor use and accuracy of models in the reviewed studies were analysed to establish the important factors. Finally, using a questionnaire survey of CI professionals, the importance levels of factors were validated using the Cronbach's alpha reliability coefficient and significant index ranking. The findings show that the important quantitative factors are profitability, liquidity, leverage, management efficiency and cash flow. While important qualitative factors are management/owner characteristics, internal strategy, management decision making, macroeconomic firm characteristics and sustainability. These factors, which align with existing insolvency-related theories, including Porter's five competitive forces and Mintzberg's 5Ps (plan, ploy, pattern, position and perspective) of strategy, were used to develop a theoretical framework. This study contributes to the debate on the need to amalgamate qualitative and quantitative factors to develop a valid CI-IPM

Chemical evaluation of foliage of some tropical leguminous trees and shrubs as fodder

Foliage of thirteen leguminous species viz: Mzelia africana, Albizia zygia, Baphia nitida, Cassia siamea, Delonix regia, Parkia biglobosa, Samanea saman, Caesalpinia pulcherrima, Cassia mimosoides, Desmodium velutinum, Flemingia macrophylla, Tephrosia bracteolata and T. densiflora were collected from the wild and the Fulani cattle rearers' settlement around Abeokuta, Nigeria. The samples were analysed for their proximate constituents: crude protein {(CP) ether extract (EE), crude fibre (CF), ash and nitrogen free extracts (NFE)} , and the levels of macro- (Ca, P, Mg, K and Na) and micro-mineral (Mn, Cu, Zn and Fe) elements. The mean values of CP, EE, CF, ash and NFE for trees were 15.2 ± 3.5, 5.2±1.7, 17.8±3.7, 6.2±2.2 and 46.8±3.1 % respectively. The corresponding values for the shrubs were 15.4±1.3, 4.1±0.9, 19.3±1.1, 6. 7±1.3 and 46.4±2. 8 %. The foliage analysed contained adequate level of Ca, Mg and Fe for growth of ruminant livestock with mean values of 0.56±0.30%, 0.16±0.08% and 131.1±74.2 ppm respectively for trees and 1.15±O.49%, 0.2 ±0.06% and 88. 7±49.9 ppm for shrubs. The levels of P, Cu, Zn and K in the foliage were inadequate using the NRC recommendations for ruminants (NRC 1981). The respective mean values were 0.09±0.06%, 3.9±3.1 ppm, 19.5±16.4 ppm, and O.07±O.5 %, 3.7±2.6ppm, 21.7±21.6 ppm and 0.21±0.14% for shrubs. The levels of Na (0.11±0.07% for trees; 0.06 0.04% for shrubs) and Mn (96. 0±142.9 ppm for trees; 49.2±27.21 ppm for shrubs) were marginally adequate. It is suggested that more effort be undertaken to conserve these species as they have better nutritive potential than grasses when used as forage in the dry season

SUBSURFACE FLOW CONSTRUCTED WETLAND SYSTEM VEGETATED WITH PHRAGMITES KARKA IN THE TREATMENT OF DYE-RICH WASTEWATER

Some major parts of tropical Africa, especially in West Africa are nowadays grappling with the problem of degradation of the quality of fresh water by the introduction of effluents containing dyes from textile industries. In this study a low cost and economical method of treating dye-rich effluent using locally available macrophyte was investigated. The pilot Constructed Wetland (CW) consists of 1200 × 1000 × 1000 mm plastic tanks, filled with 500 mm deep 10-15 mm size granite overlaid with 150 mm thick sand (Cu = 1.15 and Cc = 6.8) substrate. The substrates had an hydraulic conductivity of 0.002 m/s. The pilot CW was planted with Phragmites Karka Retz. at 200 mm c/c to provide a high density bed. Irrigation was done intermittently at 6 days retention period with 0.05 m3 indigo dye rich wastewater from the local tie and dye textile industries and plant growth monitored. Physico-chemical parameters, Cr, Pb, Cu, Zn and Fe removal were also evaluated. The study revealed a 24 % growth rate reduction in the plants irrigated with indigo dye-rich wastewater. Reduction of TDS (50 %), TSS (66 %), EC (46 %) were also observed and the heavy metals evaluated showed an uptake of 64 %, 68 %, 78 %, 58 %, and 68 % for Cr, Pb, Zn, Cu, and Fe respectively by the CW. Phragmites karka as a macrophyte in Constructed Wetland was found to be efficient in dye-rich wastewater treatment.     &nbsp

OCULAR TOLERANCE AND IN-VITRO RELEASE OF CHLORAMPHENICOL IN PROSPECTIVE EYE OINTMENT BASES

Objective: Chloramphenicol is poorly released from official eye ointment (EO) base. This study investigated alternative promising bases, enhanced drug release with surfactant and evaluated ocular tolerance of prototypes.Methods: Chloramphenicol eye ointment (1 %w/w) was prepared by levigation in five bases: EO, simple ointment (SO), hydrous wool fat (HW), hydrous sheabutter (HS), and neat sheabutter (NS). In-vitro drug release of these and EO and SO formulations containing graded concentrations (0.1–10.0 %w/v) of surfactant (polysorbate 80 or propylene glycol) were studied over 3 h by dialysis technique, and the release kinetics assessed. Water-absorption capacity (WAC) and melting temperature of the bases was determined for probable influence on drug release. Ocular tolerance of the formulations, bases and surfactants was evaluated by in vivo irritancy test on albino rabbits.Results: Total drug released from test formulations differed with base used: NS 12, HS 11, SO 7, HW 5, and EO 4 %. The Higuchi release kinetics was determined. HS and NS demonstrated highest release extent and rate; EO and HW exhibited poor release. WAC and softening temperature of bases showed some correlation with drug release propensity. Propylene glycol in EO and polysorbate 80 in SO formulations showed 3-fold and 2-fold enhanced drug release, respectively. All items for ocular toxicity test gave scores indicating practically no irritation, except neat HW that was mildly irritant.Conclusion: HS and NS proved best alternatives to EO. Propylene glycol (10 %) in the EO formulation was 3-fold drug-release enhanced. All prototype formulations were non-irritant to eye tissue