Application of Taguchi Methods and Regression Analysis to Optimize Process Parameters and Reinforcements for Maximizing Composite’s Coefficient of Friction for Brake Disc Application: A Statistical Optimization Approach

for Al-CA-PB composites, with a focus on optimizing the coefficient of friction of the composite for brake disc production. The pumice, coal ash, and aluminum alloy were characterized using X-ray fluorescence (XRF), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). The Taguchi method was employed to design the experimental runs and to identify optimal process parameters and reinforcements for maximizing the composite\u27s coefficient of friction. At the same time, regression analysis was utilized to establish a robust mathematical model for predicting the composite\u27s coefficient of friction based on the process variables. The XRF characterization results revealed that aluminum alloy contained Al, Si, and Mg as the major elements. The analysis also shows that the predominant constituents in coal ash were Si, Al, Fe, Ti, and Ca, whereas that of brown pumice particulates were Si, Fe, Al, Ca, K, and Ti. The XRD characterization analysis revealed that brown pumice and coal ash consist of SiO2, Fe2O3, and Al2O3 as the major phases, making them well-suited as reinforcement in metal matrixes. According to the thermogravimetric and differential thermal analyses, the aluminum alloy, brown pumice, and coal ash have an onset temperature of 264.08, 724 °C, and 606.61°C, respectively, before deterioration. The optimal composite\u27s coefficient of friction of 0.661 (experimental) was achieved at 2.5vol% of brown pumice, 10 vol% of coal ash, 400 rpm stirrer speed, 700 °C pouring temperature, and 15 minutes stirring duration. The developed mathematical model shows an excellent level of coefficient of friction prediction, with an R-squared value of 99.42%, 97.82%, and 76.40% for R-square, adjusted R-square, and predicted R-square, respectively

Self-efficacy, Information Accessibility and Utilization as Determinants of Creativity of Managers in Packaging Companies in Nigeria

This paper investigated self-efficacy information accessibility and utilization as factors determining creativity of managers in packaging companies in Nigeria. The research design adopted for the study was survey method. The study population comprised 540 managers in eleven packaging companies in Nigeria. The questionnaire was used to collect data from the 540 managers out of which 485 responded and valid for analysis given a response rate of 89.8 percent.The study revealed that self-efficacy, information accessibility and utilization had significant positive correlations with the creativity of the respondents. In addition, self-efficacy, information accessibility and utilization were found to be significant determinants of creativity of the managers in the packaging companies in Nigeria.It is therefore recommended that the Board of management in these companies should give much attention to self-efficacy, information accessibility and utilization when planning to improve the creativity of their managers. They should endeavour to encourage their managers to make intensive use of information and have wide access to available information resources internally and externally for better creativity. Keywords: Self-Efficacy, Information Accessibility, Information Utilization, Managers, Packaging Companies, Nigeria

Antinociceptive and anti-arthritic properties of hydroethanolic leaf extract of Clausena anisata (Willd.) Hook. f. ex Benth (Rutaceae) in Rodents: possible mechanism of actions

Summary: The leaves of Clausena anisata (Willd.) Hook. f. ex Benth (Rutaceae) is used in Traditional African medicine for the treatment of various ailments including arthritis. The present study sought to investigate the antinociceptive and anti-arthritic properties of hydroethanolic leaf extract of Clausena anisata (HeCA). HeCA (100, 200 or 400 mg/kg, p.o.) was administered 1 h before intraplantar injection of formalin 1%v/v in saline to evaluate antinociceptive effect. Moreover, its possible mechanism of antinociceptive action was investigated through pretreatment of mice with antagonists of receptors implicated in nociception. Anti¬inflammatory effect of the extract was investigated using the carrageenan-induced paw oedema and complete Freund's adjuvant (CFA)-induced arthritis models in rats. HeCA (400 mg/kg) treatment significantly reduced the duration of paw licking/biting during both in the early (42.12%) and late (75.79%) phases of formalin-induced nociception. However, the antinociceptive effect elicited by HeCA was reverse by pretreatment of mice with naloxone, prazosin, yohimbine, ketanserin, L-arginine, and parachlorophenylalanine (PCPA). HeCA produced dose-dependent and time course decrease in carrageenan-induced paw oedema. Pre- and post-treatment of rats with HeCA ameliorated CFA-induced arthritis evidenced in the significant decrease in arthritic index comparatively similar to the effect of celecoxib. CFA- induced oxidative and nitrosative stress were attenuated by subchronic treatment with HeCA. Findings from this study shows that C. anisata possesses antinociceptive activity through possible interaction with opioidergic, noradrenergic, L-arginine-nitric oxide and serotonergic pathways as well as anti-arthritic property which could be attributed to its ability to prevent the release of inflammatory mediators and oxidative stress.Keywords: Complete Freund's adjuvant; L-arginine-nitric oxide; nociception; antioxidant; rheumatoid arthritis; serotonergic

Correlation of Features of Allergic Rhinitis and Allergic Conjunctivitis with Treatment Modalities

Introduction: Allergic Rhinitis (AR) is a chronic, symptomatic allergic disorder of the nose that is usually caused by IgE-mediated inflammatory response following exposure to an allergen. The allergen could be in the form of dust, pollen, flower, animal dander, mold, cold, food allergens or insect. Clinically, AR occurs when there are recurrent nasal symptoms which are reversible either spontaneously or with medication in the preceding one year. Such symptoms include at least two of the following; excessive sneezing, running nose, nasal itching, nasal discharge, nasal congestion or obstruction. Previous studies have linked AR to be co-existed with another form of allergic disorders including AC, Atopic dermatitis and Allergic Asthma. This study is aimed at assessing the feature of AR patients with coexistent AC as well as evaluating the effectiveness of the treatments offered to them. Objectives: The study was aimed at finding the correlation between the nasal and eye features in a patient who has co-existing allergic rhinitis and allergic conjunctivitis. Methodology: This was a cross-sectional descriptive study conducted between August 2018 and November 2019 among 38 patients who presented to ENT and Ophthalmology departments of Federal Teaching Hospital Ido-Ekiti, Ekiti State, Southwestern Nigeria and was diagnosed with both allergic rhinitis and allergic conjunctivitis. Relevant data obtained were analyzed using SPSS version 20. P ≤ 0.05 was taken as significant. Results: The patients’ age range between 8 and 81 years with a median age of 33 years. The majority were less than 45 years (63.2%) with the male to female ratio of almost. Eye pain, itching, and redness account for 97.4% of all the eye features, while the presence of Cobblestone-like papillae is the least and accounted for 5%. Nasal itching (92.1%) was the commonest nasal symptom. Sleep disturbance was found to be the most common among those with eye itching (29.7%). Conclusion: This research was conducted to correlate the features of allergic rhinitis with those of conjunctivitis and common management and preventive measures offered to the patients seen in our clinics. The majority of the patients were less than 45 years with almost equal sex ratio. Eye pain, itching, and redness account for the majority of all the eye features, while the presence of Cobblestone-like papillae is the least eye feature. Nasal itching was the commonest nasal symptom and this was seen in the majority of the patients with eye symptoms

Evaluation of Radiation Emissions, Physico-Chemical Parameters and Insect Fauna around the Environment of National Institute of Radiation Protection and Research

Abstract: Radiation emissions from the University of Ibadan National Institute of Radiation Protection and Research (NIRPR), physico-chemical properties measurement and insect's fauna collection around the surrounding of the Institute were conducted for a period of six months (November, 2011-April, 2012. Radiation survey meter model (RDS-30) type was used to take readings along the immediate surroundings of the NIRPR surroundings. Soil samples were collected at five points in the study site at a distance of 50 m from the Institute and the football pitch with a distance of 250 m away from the Institute as control site. Heavy metals (Fe, Cu, Zn, Cr, and Pb) were analysed using MiniPal 4 energy-dispersive X-Ray fluorescence (EDXRF) bench top spectrometer. Pit falls and sweep net were used in collection of crawling and flying insects respectively, some other arthropods were also collected. Results showed that radiation emission values of 0.012-0.016 µSv/hr was recorded, which was higher than the control site with reading of 0.009 µSv/hr. Heavy metal readings showed that iron (Fe) was higher at the sites than other metals. Correlation between chromium and lead was high (0.797) at (p<0.01). Diversity indices (Margalef, Shannon Wiener and Evenness respectively) for control site (3.56, 0.54, and 0.52) were higher than at the study site (2.62, 0.15 and 0.17). There was no correlation between arthropods abundance and radiation. This result therefore suggests that radiation could not be implicated in abundance and distribution of these arthropods

Dichlorvos Induced AChE Inhibition in Discrete Brain Regions and the Neuro-Cognitive Implications: Ameliorative Effect of Nigella Sativa

Background: There has been a rise in accidental poisoning cases resulting from the indiscriminate use and exposure to Dichlorvos (DDVP), especially in developing countries, and no antidote with satisfactory efficacy is currently available. Thus, we investigated the AChE reactivation potential of Nigella sativa oil (NSO) following DDVP induced AChE inhibition patterns in the brain and the associated cognitive implications. Methods: Fourty Wistar rats were randomly divided into four groups of 10 each.; The controls were administered PBS (1 ml/kg); DDVP (8.8 mg/kg) was given to the experimental group I; while DDVP+NSO (8.8 mg/kg + 1 ml/kg) and NSO (1 ml/kg) was administered orally to the experimental groups II and III respectively. All treatments lasted for 14 consecutive days. Morris Water Maze (MWM) paradigm was used to assess the working memory, then rats were euthanized, the brain excised, three brains were fixed for histological examination (Nissl staining), and the other seven brains were homogenized for AChE activity and Ca2+ concentrations. Data were analyzed statistically, using ANOVA method and P values of ≤0.05 was considered as significant. Results: In this study, DDVP differentially inhibited AChE activities in various brain regions: cerebellum (86.1%), hippocampus (40.6%), frontal cortex (33.2%), medulla (21.5%), spinal cord (14.8%), and occipital cortex (8.9%). It reduced Ca2+ concentration, but had no effect on the delayed escape latency in the MWM, nor impaired the neuro-architectures. NSO caused increased AChE activities, Ca2+ concentration and reduced escape latency, and improved histologic architectures. Conclusion: We concluded that NSO reactivated DDVP-induced AChE inhibition and improved memory indices, thus, it may serve as a potential treatment in the management of DDVP poisoning cases

The Mediating Effect between Some Determinants of SME Performance in Nigeria

The purpose of this study is to examine the relationship of owner/manager knowledge, competitive intensity, complexity of marketing, technical competence, firm size with the mediation of advisory services on the performance of Nigerian SMEs. The study employed structured questionnaire survey involving a sample of 278 manufacturing SMEs operating in Kano State, a total of 198 valid questionnaires were completed and returned representing 71 percent response rate. Evidence suggests that there is significant relationship between owner/manager knowledge, complexity of marketing decision and technical competence and advisory services. In contrast, the result found no significant relationship between firm size and advisory services. Similarly, the result found that owner/manager knowledge, complexity of marketing decision, technical competence and advisory services have significant relationship with performance. The result also indicates that, there is no significant relationship between firm size performance and technical competence and Performance. We also found that advisory service mediates the relationship between owner manager knowledge and the complexity of marketing decision. The findings of this study will benefit owner/managers of SMEs, regulatory agencies, accounting firms, government at all levels and will also serve as frame of reference to future studies

The Mediating Effect between Some Determinants of SME Performance in Nigeria

The purpose of this study is to examine the relationship of owner/manager knowledge, competitive intensity, complexity of marketing, technical competence, firm size with the mediation of advisory services on the performance of Nigerian SMEs. The study employed structured questionnaire survey involving a sample of 278 manufacturing SMEs operating in Kano State, a total of 198 valid questionnaires were completed and returned representing 71 percent response rate. Evidence suggests that there is significant relationship between owner/manager knowledge, complexity of marketing decision and technical competence and advisory services. In contrast, the result found no significant relationship between firm size and advisory services. Similarly, the result found that owner/manager knowledge, complexity of marketing decision, technical competence and advisory services have significant relationship with performance. The result also indicates that, there is no significant relationship between firm size performance and technical competence and Performance. We also found that advisory service mediates the relationship between owner manager knowledge and the complexity of marketing decision. The findings of this study will benefit owner/managers of SMEs, regulatory agencies, accounting firms, government at all levels and will also serve as frame of reference to future studies

Effect of Scent Leaf on Haematological Indices of Broilers

A 56-days feeding trial was conducted to evaluate the effects of dietary inclusion of Ocimiumm gratissimmum leaf meal on the haematological indices of broilers. The Ocimum gratissimmum leaves uses in the experiment were manually harvested, air-dried and milled to become Ocimum gratissimmum leaf meal. The Ocimum gratissimmum leaf meal was included in broiler starter to finisher diets at 0.50,100, and 150g levels respectively. One hundred and twenty unsexed day old broilers chicks Arbor acre broiler chicks were raised on self-compounded mash for eight were used. They were divided into 4 groups of 30 birds each and randomly assigned to the 4 experimental diets in a completely randomized design (CRD). Each group was sub-divided into 3 replicates of 10 birds each and each replicate housed in a cage fitted with necessary brooding facilities. Feed and water were given to them ad libitum for 8 weeks. At the end of the feeding trial, blood was collected from the birds, 3 per treatment and analyzed for haematological incides. Haemoglobin (Hb) and packed cell volume (PVC) of birds were not significantly reduced (P<0.05) but were within considerate range normal for birds. The haematological parameters obtained from this suggest that dietary inclusion of Ocimum gratissimmum leaf meal has no deleterious effects on the internal physiology of broiler

Whole-genome analysis of Nigerian patients with breast cancer reveals ethnic-driven somatic evolution and distinct genomic subtypes

Black women across the African diaspora experience more aggressive breast cancer with higher mortality rates than white women of European ancestry. Although inter-ethnic germline variation is known, differential somatic evolution has not been investigated in detail. Analysis of deep whole genomes of 97 breast cancers, with RNA-seq in a subset, from women in Nigeria in comparison with The Cancer Genome Atlas (n = 76) reveal a higher rate of genomic instability and increased intra-tumoral heterogeneity as well as a unique genomic subtype defined by early clonal GATA3 mutations with a 10.5-year younger age at diagnosis. We also find non-coding mutations in bona fide drivers (ZNF217 and SYPL1) and a previously unreported INDEL signature strongly associated with African ancestry proportion, underscoring the need to expand inclusion of diverse populations in biomedical research. Finally, we demonstrate that characterizing tumors for homologous recombination deficiency has significant clinical relevance in stratifying patients for potentially life-saving therapies