Decentralization of Markets and Environmental Sanitation Scheme: A Focus on Urban Core of Akure, Nigeria

Unplanned and overcrowded market places especially in developing countries usually grapple with sanitation problems. This phenomenon poses threats such as pollution of the environment and deterioration of city landscape. In Akure the capital of Ondo State, Nigeria, government in its urban renewal effort introduced neighbourhood markets in a decentralized market system, as a way of resolving these problems. This study focuses on the extent of these urban renewal efforts and their impacts on the socio-economic and general wellbeing of the market users. It further suggests ways to achieve proper sanitation in markets places in a manner that is sustainable. The methodology includes the use of structured questionnaires, interviews, as well as observations. The study reveals a successful decongestion of the king’s market and a considerable improvement in sanitation. It concludes that sanitation in market places is absolutely expedient to ensure public health and proper public hygiene. Keywords: Decentralization, pollution, sanitation, urban core, market

Influence of laser power on microhardness and wear resistance properties of laser metal deposited 17-4 PH stainless steel

Abstract: This aim of this research is to investigate the impact of laser power on the hardness and the wear resistance properties of laser metal deposited 17-4 PH stainless steel. Hardness was studied using Zwick/Roell microhardness tester and the wear resistance property was carried out using ball-on-disc Anton Paar-tribometer wear tester. The study revealed that an irregular increase and decrease in the average hardness value and wear behaviour were observed. This could be attributed to the presence of copper precipitate which was more concentrate at the overlapping region because of the reheating activity that is happening between the succeeding and preceding track layers

Microstructural evolution of laser metal deposited 17-4 PH SS-tungsten composite with varying volume percent tungsten

Abstract: This study investigates the influence of quantity of tungsten powder on the microstructural evolution of 17-4 PH stainless steel-tungsten composite produced using laser metal deposition process. The 17-4 PH stainless steel and tungsten powders were deposited on 316 stainless steel substrate at laser power of 2600 W. The tungsten powder flow rate was varied between 0.5 rpm and 2.0 rpm while 17-4 PH stainless steel powder flow rate, the scanning speed, the gas flow rate and the laser spot size were fixed at 2.0 rpm, 0.5 m/s, 2.5 l/min and 2.0 mm respectively. Five (5) multiple track of 17-4 PH stainless steel and tungsten powder were deposited on 316 stainless steel of thickness 10 mm from different hopper at 50% overlapping percentage to produce 17-4 PH SS-W composite. During the microstructural study, it was observed that tungsten carbide has been precipitated in-situ and evenly dispersed in the 17-4 PH SS-W composite produced. SEM and EDS analysis also revealed the presence of BCC alpha (α) ferrite and FCC gamma (δ) ferrite with the presence of sigma (σ) phase precipitates

Spatial analysis of soil hydraulic properties of an alfisol in Akure, Southwestern Nigeria

The knowledge of soil hydraulic properties and processes leads to better predictions of both agricultural and environment impact. The objectives of this research are to determine, predict and compare the relationship between measured and estimated soil hydraulic properties and also spatially characterize these properties using geostatistics. Mini disc infiltrometer at a suction rate of 2 cm per second was used for the determination of soil hydraulic properties at different points of an alfisol in Nigeria. Soil samples (100, 200 and 300 mm depths) were also analyzed to determine soil bulk density (BD), total porosity (PT) and water holding capacity (WHC). The coefficients of variation (CV) of the textural classes indicate a non-considerable variability of the sand (CV=6%), silt (CV=20%) and clay (CV=3%) contents. From the statistical and spatial analysis for the different parameters, the variability of hydraulic conductivity (48%>33%>31%), cumulative infiltration (40%>26%>23%), soil water sorptivity (19%>11%>8%), followed the trend upper soil layer (0–100 mm) > middle (100–200 mm) > lower (200–300 mm) soil layers. Hydraulic conductivity and infiltration were more pronounced in soils with higher organic matter content (OMC) and PT. Pedotransfer models (PTF) for prediction of hydraulic conductivity (K), soil water sorptivity (Sw) and cumulative infiltration (I) from basic soil properties such as OMC, PT were developed and validated using multiple-linear regression method. K, Sw and I predicted by the PTF models were significant for the upper and middle soil layers respectively (r = 0.812 and 0.670; 0.825 and 0.670, and 0.820 and 0.670). Contour and wireframe representation were used to spatially analyze the soil hydraulic properties across the field. These contour and 3D surface plots are useful for establishing farm operating conditions, especially in water, fertilizers or pesticides management

Influence of laser power on microstructure of laser metal deposited 17-4 ph stainless steel

Abstract: The influence of laser power on the microstructure of 17-4 PH stainless steel produced by laser metal deposition was investigated. Multiple-track of 17-4 stainless steel powder was deposited on 316 stainless steel substrate using laser metal deposition, an additive manufacturing process. In this research, laser power was varied between 1.0 kW and 2.6 kW with scanning speed fixed at 1.2 m/s. The powder flow rate and the gas flow rate were also kept constant at values of 5 g/min and 2 l/min respectively. The microstructure was studied under optical microscope and it revealed that the microstructure was dendritic in structure with finer and lesser δ-ferrite at low laser power while the appearance of coarse and more δ-ferrite are seen at higher laser power

Comparison of Electrode Configurations for Impedance Plethysmography Based Heart Rate Estimation at the Forearm

Electrical impedance plethysmography (EIP) is a cost effective and power efficient physiological measurement method that could potentially be applied for measuring pulse waves along limbs in ambulatory conditions. The pulse wave information could be utilized to determine the heart rate or other relevant parameters such as heart rate variability or cardiac rhythm. We compared three electrode configurations for EIP at the forearm, with the focus on assessing its utility in a wearable device. The evaluation included EIP measurements with ten healthy participants using adhesive gel electrodes. The evaluated electrode configurations were tetrapolar configuration along the forearm and tetrapolar and bipolar configurations around the wrist. For each electrode configuration, the measurements were performed in stationery condition and during finger movement. The collected data was evaluated for finding out differences in the signal to noise ratio (SNR) between the configurations during the two conditions. The results show that pulse wave signal with adequate SNR for heart rate estimation is obtained from the wrist area while stationary and mostly also during the presence of mild movement. There was no significant difference in the data quality between wrist area and conventional configuration along the limb.acceptedVersionPeer reviewe