Development and evaluation of a drill re-grinding fixture

Generally, manual method of re-grinding drills poses the dangers of damage and accidents. This paper reports the method used in the design, fabrication and testing of the drill re-grinding fixture. The fabricated fixture can withstand maximum normal and tangential forces of 121.34 N and 87.76 N respectively. The developed fixture shows it is suitable as work holding device for re-grinding drills bits with diameter of at least 4.5 mm and above without breakage and difficulty. The average time for complete re-grinding is about six minutes (loading and unloading time inclusive) and no injuries were recorded. The grinded surfaces conform to the standard tool geometry for a twist drill. Hence, the use of this drill re-grinding fixture in the engineering workshops obviates the rigor of manual handling of drills during grinding.Keywords: design, evaluation, drill, fixture, grinding, cost

Survey data on factors affecting negotiation of professional fees between Estate Valuers and their clients when the mortgage is financed by bank loan: A case study of mortgage. valuations in Ikeja,Lagos State,Nigeria

In this article,two sets of questionnaires were administered to professionals and clients(commercial banks)on their willingness to negotiate the professional fees charged by the Estate Valuers assuming that the mortgage in valuation was financed by bank loan. A range of fees options were provided.Other factors such as the business environment and mortgage valuation can influence the negotiated fees when the data obtained from the survey data is analyzed

Effect of spatial configuration of an extended nonlinear Kierstead-Slobodkin reaction-transport model with adaptive numerical scheme

In this paper, we consider the numerical simulations of an extended nonlinear form of Kierstead-Slobodkin reaction-transport system in one and two dimensions. We employ the popular fourth-order exponential time differencing Runge-Kutta (ETDRK4) schemes proposed by Cox and Matthew (J Comput Phys 176:430-455, 2002), that was modified by Kassam and Trefethen (SIAM J Sci Comput 26:1214-1233, 2005), for the time integration of spatially discretized partial differential equations. We demonstrate the supremacy of ETDRK4 over the existing exponential time differencing integrators that are of standard approaches and provide timings and error comparison. Numerical results obtained in this paper have granted further insight to the question "What is the minimal size of the spatial domain so that the population persists?" posed by Kierstead and Slobodkin (J Mar Res 12:141-147, 1953 ), with a conclusive remark that the popula- tion size increases with the size of the domain. In attempt to examine the biological wave phenomena of the solutions, we present the numerical results in both one- and two-dimensional space, which have interesting ecological implications. Initial data and parameter values were chosen to mimic some existing patternsScopus 201

Amphibian host-defense peptides with potential for Type 2 diabetes therapy - an updated review

Investigations conducted since 2018 have identified several host-defense peptides present in frog skin secretions whose properties suggest the possibility of their development into a new class of agent for Type 2 diabetes (T2D) therapy. Studies in vitro have described peptides that (a) stimulate insulin release from BRIN-BD11 clonal β-cells and isolated mouse islets, (b) display β-cell proliferative activity and protect against cytokine-mediated apoptosis and (c) stimulate production of the anti-inflammatory cytokine IL-10 and inhibit production of the pro-inflammatory cytokines TNF-α and IL-1β. Rhinophrynin-27, phylloseptin-3.2TR and temporin F are peptides with therapeutic potential. Studies in vivo carried out in db/db and high fat-fed mice have shown that twice-daily administration of [S4K]CPF-AM1 and [A14K]PGLa-AM1, analogs of peptides first isolated from the octoploid frog Xenopus amieti, over 28 days lowers circulating glucose and HbA1c concentrations, increases insulin sensitivity and improves glucose tolerance and lipid profile. Peptide treatment produced potentially beneficial changes in the expression of skeletal muscle genes involved in insulin signaling and islet genes involved in insulin secretion in these murine models of T2D. Lead compounds uncovered by the study of frog HDPs may provide a basis for the design of new types of agents that can be used, alone or in combination with existing therapies, for the treatment of T2D.

STRUCTURAL ANALYSIS OF A LIGHTWEIGHT ELECTRIC VEHICLE CHASSIS

This study presents a comprehensive investigation into the design and structural analysis of lightweight chassis for electric vehicles. A chassis needs to be able to withstand twist, shock, vibration, and other stresses caused by acceleration, braking, road condition, and shock initiated by other parts of a vehicle. It should carry a maximum load under all operating conditions. Two materials, 304L steel, and Ti-6AL-4V alloy were evaluated, with parameters such as total deformation, equivalent stress, and equivalent elastic strain under consideration. The outcome of the Finite Element Analysis revealed that Ti-6AL-4V can withstand higher stresses than 304L Steel. By investigating the static behaviors of the chassis under static loading due to weight and overload conditions, Ti-6AL-4V was chosen as a suitable replacement for a 304L Steel chassis

Methyl orange, an organic dye: its health impact and sorptive removal from waste water

AbstractMethyl Orange (MO) a member of Azo dyes are commonly used as synthetic dyes in textile, food, paper and cosmetics. Their use is easy and cost-effective, compared with natural dyes. However, azo bonds are hardly removed because of their high water solubility as well as low exhaustion with the potential for persistence and accumulation in the environment, therefore aqueous solution of MO is toxic and irritating. Thus, the removal of them from industrial wastewaters is capital with regard to protect public health, environment, and aquatic life

Effects of acute exposure to cotton insecticide thalis 112 EC (emamectin benzoate 48 g.l-1 and acetamiprid 64 g.l-1) in African catfish Clarias gariepinus embryos

Thalis 112 EC, a binary insecticide based on Emamectin benzoate (48 g.L-1) and Acetamiprid (64 g.L-1), is widely used in agriculture in Benin, to control cotton pests including Helicoverpa armigera. In order to assess the impact of acute concentrations of this binary on the development of  eggs/embryos of the African catfish Clarias gariepinus, an experiment was conducted in the laboratory. The fertilized eggs of C. gariepinus (n 100)  were exposed to six concentrations of Thalis (T0: 0.0; T1: 10.0; T2: 60.0; T3: 110.0; T4: 160.0 and T5: 210.0 ppm), each in three replicates. The  arithmetic method of Karber was used to calculate LC50 values. The 24h-LC50 and 48h-LC50 values of Thalis for eggs/embryos were 124.09 and  117.58 ppm, respectively. High Thalis concentrations significantly increased eggs/ embryos mortality and decreased hatching success (p<0.05,  Dunnett’s test). Rates of various physical deformities such as short-tail and lordosis, and the abnormalities such as black pigmentation on yolk sac,  intense lethargy, etc., also climbed with increasing Thalis concentrations (p<0.05, Dunnett’s test). The findings from the current study showed that  Thalis exerts adverse effects on embryo development of C. gariepinus. They constitute an alert on the toxic effect of chemical pesticides used in  Benin on the first developmental stages of fish inhabiting aquatic ecosystems. &nbsp

SYSTEMATIC REVIEW OF BUILDING FAILURE AND COLLAPSE IN NIGERIA

Building failure often results to collapse if not discovered and addressed. Many authors have in times past discussed on various factors that contribute to incessant building failure and collapse in Nigeria. Most of the findings are based on individual findings and as such, general consensus on the causes of building failures and collapses in Nigeria have not been reached. This systematic review harmonizes the various causes from papers indexed in Scopus database and recommendations were given. The causes of building collapse in Nigeria are: poor materials used in the construction of buildings, geophysical or natural causes, structural defects, failure of efficient management of construction processes, construction defects, corruption or sharp practices and noncompliance to legal requirements in the building industry. The review concluded with some likely research areas on building failure and collapse as it relates to the study are