Structural and properties of Zn-Al2O3-SiC nano-composite coatings by direct electrolytic process

In this paper, Zn-SiC and Zn-Al2O3-SiC composite coating were fabricated by electrodeposition technique from sulfates bath. The resulting composite coating was carried out by adding Al2O3/SiC particulate to a zinc-containing bath. The properties of the composite coating were investigated by SEM equipped with EDS, XRD, and AFM. The electrochemical behavior of the coating alloy was evaluated in 3.65 % NaCl with linear polarization technique and mechanically examined by durascan microhardness tester. The morphology of the thermal treated coatings at 400 °C in 6 h was viewed with high optical microscope (OPM). The results show hardness, thermal stability, and anti-corrosion properties of Zn-Al2O3-SiC were improved significantly as against Zn- SiC coating matrixes. This was attributed to dispersive strengthening effect and grain induced effort of Al2O3/SiC particulate. The decrease in corrosion and thermal stability at 15 g/L of SiC concentration may be as a result of agglomeration and the superimposed particle in the plating bath

A Mini Review on the Impact of Sewage Disposal on Environment and Ecosystem

Human activities contribute immensely to the production of wastewater which emanates from residences, industries and agricultural practices that pollutes the environment and water bodies. Up to 80-90% of the wastewater produced in developing countries is disposed of into surface and groundwater which is a major cause of environmental pollution that threatens human health. According to UN report, over 80% of the wastewater produced in the world and over 95% in some least developed countries is released without being treated into the environment. This paper reviews the methods of sewage disposal, the impact on the environment, aquatic contaminant and the human health. Emphasis is placed on the impact of disposal of various contaminants in aquifers and water bodies which could make water unsafe for drinking and to perform other domestic and recreational activitie

Production of Biodiesel from Soybean Oil Using Calcium Oxide and Cow Bone as Catalysts

Biodiesel was produced from the transesterification of soybean oil using calcium oxide and cow bone (an animal waste bone that contains hydroxyapatite, a calcium phosphate mineral) as heterogeneous catalysts. The soybean oil used was characterized using gas chromatography mass spectrometer (GCMS) and the cow bone catalyst produced was characterized using X-ray diffractometer (XRD) and X-ray fluorescence (XRF) spectrometer. The effects of the variation of methanol/oil mole ratio (9–15), catalyst concentration (10–20 wt/wt%) and reaction temperature (55–65 °C) on biodiesel yield during the transesterification of soybean oil with methanol was investigated. Reaction time of 3 hours and stirring rate of 500 rpm were kept constant. It was observed that the calcination of cow bone catalyst (at 800 °C) enhanced its conversion to apatite [Ca5(PO4)3OH] and increased the yield of biodiesel obtained. Biodiesel yield results revealed an optimum condition of methanol/oil mole ratio of 9, catalyst concentration of 15 wt/wt% and reaction temperature of 55 °C. Also, the results obtained showed that the performance trends of the two catalysts used were similar. And the close values of highest biodiesel yields obtained when the two heterogenous catalysts were used separately (yields of 94.8 and 92.2% using calcium oxide and calcined cow bone catalysts respectively) implies that the use of low-cost and readily available calcined cow bone catalyst is a promising alternative to CaO catalyst

Composición en nutrientes de cinco variedades de maní (Arachis hypogaea L.) de consumo habitual en Nigeria

The nutrient composition of the five major varieties of groundnut (Arachis hypogaea L.) commonly consumed in the south-western part of Nigeria was investigated. Raw dryshelled samples were analyzed for proximate (moisture, ash, protein, fat, fiber and carbohydrate), ‘vitamins’ (β-carotene, thiamine, niacin and tocopherol) and minerals (Na, K, Ca, P, Mg, Fe, Mn, Zn, Cu, Se, Co, Al, As, Cd and Pb). Results showed that the groundnuts had 4.12-9.26% moisture, 2.77-3.31% ash, 24.26-26.35% protein, 45.41-48.14% fat, 2.51-2.94% fiber and 15.90-17.75% carbohydrate. All the varieties analyzed showed β-carotene (63.32-65.35mg/100g), thiamin (0.73-0.98mg/100g), niacin (14.00-16.03mg/100g) and tocopherol (18.62-21.07mg/100g) activities; with boro red having significantly (P P> Mg> Ca> Mn> Cu> Na> Zn> Fe> Al> Se in most of the varieties. Boro red also had the highest elemental contents in most of the minerals analyzed. Thus, these groundnuts can be considered useful foodstuffs in minimizing proteinenergy malnutrition (PEM) and micronutrient deficiencies in Nigeria. However, the boro red variety is most recommended. The outcome of this research is a contribution to the food composition table.Se ha investigado la composición en nutrientes de las cinco principales variedades de maní (Arachis hypogaea L.) de consumo habitual en la parte sur-occidental de Nigeria. A las muestras crudas con cáscara y secas se les analizó su composición proximal (humedad, ceniza, proteína, grasa, fibra e hidratos de carbono), vitaminas (β-caroteno, tiamina, niacina y tocoferol) y minerales (Na, K, Ca, P, Mg, Fe, Mn, Zn, Cu, Se, Co, Al, As, Cd y Pb). Los resultados mostraron que el maní tenía entre 4.12 - 9.26% de humedad, 2.77- 3.31% de cenizas, 24.26 - 26.35% de proteína, 45.41 - 48.14% de materia grasa, 2.51 - 2.94% de fibra y 15.90 -17.75% de carbohidratos. Todas las variedades analizadas contenían β-caroteno (63.32-65.35mg/100g), tiamina (0.73-0.98mg/100g), niacina (14.00-16.03mg/100g) y tocoferoles (18.62-21.07mg/100g), siendo la variedad “Boro rojo” la que contiene las cantidades significativamente más altas (P P> Mg> Ca> Mn> Cu> Na> Zn> Fe> Al> Se. La variedad “Boro rojo” también tuvo el mayor contenido elemental en la mayoría de los minerales analizados. Por lo tanto, estos cacahuetes de la variedad “Boro rojo” es la más recomendable y pueden ser considerados unos productos alimenticios útiles para minimizar la malnutrición proteico-energética (MPE) y las deficiencias de micronutrientes en Nigeria. El resultado de esta investigación puede suponer una significativa contribución a la tabla de composición de alimentos

Dataset on noise level measurement in Ota metropolis, Nigeria

Datasets contained in this article are noise level measurementcarried out at 41 different locations in Ota metropolis, Nigeria. Thenoise readings were measured at a time interval of 30 min for eachsite considered using a precision grade sound level meter. Theanalysis was based on the noise descriptors LAeq,L10,L90,LD, TNIand NEI. Results from the study reflects that the highest and lowestequivalent noise levels (LAeq) were recorded at commercial areas(96 dB (A)) and residential areas (52 dB (A)), respectively, thebackground noise level (L90) has the highest and lowest values atcommercial areas (77 dB (A)) and residential areas (44 dB (A)),respectively and the peak value (L10) has the highest value andlowest value at the commercial areas (96 dB (A)) and residentialareas (56 dB (A)). Based on the WHO recommendations and stan-dards, only 2 out of the 41 locations considered are under normallyacceptable situation while the noise levels of other areas are notacceptable. Noise map developed in this study provides enoughinformation for technical controls and interim legislation againstenvironmental noise pollution in the metropolis. Moreover, con-sidering the noise emission standards, planning and promoting thecitizens awareness about the high noise risk could help to mitigatethe effect of noise in Ota, Metropolis. The noise data in this study are useful as reference and guideline for future regulations onnoise limit to be implemented for urban areas in Nigeria anddeveloping countries at large

A comparative analysis of the chemical composition and compliance level to established standards of concrete reinforcement steel rods rolled in Nigeria

Nigeria is presently facing the challenges of collapsing buildings and bridges due to substandard materials used as reinforcement products. The increasing use of scraps as feedstock for the production of reinforcing steel bars by steel rolling mill companies has adversely affected the quality of rebars in Nigeria. This research study aimed to appraise the chemical properties of selected brands of steel rebars of Nigeria. Thirty selected brands of rebars were sourced from the six geopolitical zones in Nigeria, and their chemical compositions were analysed for level of compliance with five selected standards (SON, BSI, ASTM, AISI, ISO). The chemical composition test was performed using Optical Light Spectrometric methods. One way analysis of variance (ANOVA) test was performed using SPSS version 20 to examine whether significant differences exist or not in mean chemical composition for the different categories of selected steel rods. Statistical analysis shows a significant difference (P < 0.05) in chemical composition and compliance level between the different types of selected steel rods. The imported steel rods recorded the highest mean (μ = 101.4) in terms of chemical composition and compliance, followed by locally rolled from imported billets (μ = 101.2), TMT steel rods (μ = 101.0), and ordinary steel rods (μ = 100.6). Concerning CEV1 and CEV2, it was observed that all the brands were fully compliant within the maximum permissible ranges given in the local, foreign and international standards except an ordinary steel bar of Brand 16, which has value beyond the specified limits of CEV1. This study also shows that all imported and 77.8% of locally-rolled steel bars are low-carbon steel as specified by the selected standards

Wastewater-based epidemiology in hazard forecasting and early-warning systems for global health risks

With the advent of the SARS-CoV-2 pandemic, Wastewater-Based Epidemiology (WBE) has been applied to track community infection in cities worldwide and has proven succesful as an early warning system for identification of hotspots and changingprevalence of infections (both symptomatic and asymptomatic) at a city or sub-city level. Wastewater is only one of environmental compartments that requires consideration. In this manuscript, we have critically evaluated the knowledge-base and preparedness for building early warning systems in a rapidly urbanising world, with particular attention to Africa, which experiences rapid population growth and urbanisation. We have proposed a Digital Urban Environment Fingerprinting Platform (DUEF) – a new approach in hazard forecasting and early-warning systems for global health risks and an extension to the existing concept of smart cities. The urban environment (especially wastewater) contains a complex mixture of substances including toxic chemicals, infectious biological agents and human excretion products. DUEF assumes that these specific endo- and exogenous residues, anonymously pooled by communities’ wastewater, are indicative of community-wide exposure and the resulting effects. DUEF postulates that the measurement of the substances continuously and anonymously pooled by the receiving environment (sewage, surface water, soils and air), can provide near real-time dynamic information about the quantity and type of physical, biological or chemical stressors to which the surveyed systems are exposed, and can create a risk profile on the potential effects of these exposures. Successful development and utilisation of a DUEF globally requires a tiered approach including: Stage I: network building, capacity building, stakeholder engagement as well as a conceptual model, followed by Stage II: DUEF development, Stage III: implementation, and Stage IV: management and utilization. We have identified four key pillars required for the establishment of a DUEF framework: (1) Environmental fingerprints, (2) Socioeconomic fingerprints, (3) Statistics and modelling and (4) Information systems. This manuscript critically evaluates the current knowledge base within each pillar and provides recommendations for further developments with an aim of laying grounds for successful development of global DUEF platforms