Thermal diffusivity behaviour of multi-walled carbon nanotube reinforced Ti6Al4V metal matrix composites

Abstract: This study investigated the thermal diffusivity behaviours of spark plasma sintered (SPS) multi-walled carbon nanotubes (MWCNTs) reinforced Ti6Al4V composites containing 0, 1, 2 and 3 wt. % of the reinforcement respectively, over a range of 50 – 300 °C. The MWCNTs were dispersed into the Ti6Al4V matrices by high-energy ball milling (HEBM) technique and the milled composite powders were consolidated by SPS under a vacuum atmosphere. The sintering conditions employed were heating rate (100 °C/min), holding time at temperature (5 min), sintering temperature (850 °C) and applied pressure of 50 MPa. The relative densities of the composite discs were measured according to Archimedes’ principle while the thermal diffusivities of as-sectioned composite samples were measured using the Laser Flash equipment. Relative densities of the synthesized nanocomposites deteriorated with increase in the weight fraction of MWCNTs added to Ti6Al4V. The thermal diffusivities of the composites containing 1 and 2 wt. % MWCNTs improved with increase in temperature and weight fraction of MWCNTs contents. A reverse trend was observed in the composite containing 3 wt. % MWCNTs, as the measured thermal diffusivities continued to drop with increase in temperature. Although this composite exhibited the best thermal diffusivities compared to the other composites up to 200 °C, a significant drop in thermal diffusivity was recorded between 250 and 300 °C respectively with the values lower than that of the unreinforced Ti6Al4V alloy. However, the thermal diffusivities of MWCNTs/Ti6Al4V composites were generally not dependent on their densification as the composites with higher weight fractions of the reinforcement had higher thermal diffusivities in spite of their lower relative densities

Design and Fabrication of an Automated Low-Cost Non-Contact Temperature Scanner and Sanitizer for Covid-19 Prevention

The rate at which the novel virus Covid-19 spread across the world in an alarming rate with high rate of death of the infected persons is quite disturbing, hence the need to checkmate its spread by quickly identifying persons with the symptoms of this viral infection. This paper discusses the development of an automated low-cost non-contact temperature scanner and sanitizer. The system automatically detects a human being, scans for temperature, and sanitizes the person with no interference required. The circuit for the system comprises an Arduino microcontroller, LCD display, relays, ultrasonic sensors, temperature sensor, 12v DC pump motion sensor and a high pressure 12v DC pump. The temperature sensor (MLX90614) senses the temperature, certifies that the value is within the specified range as controlled by its ultrasonic sensor and displays the temperature on the LCD. Thereafter, an ultrasonic sensor activates the 12V DC pump to dispense the sanitizer. At the disinfectant chamber, the motion sensor will trigger the high-pressured DC pump when it senses movement, it dispenses the body sanitizer through the nozzles. C++ was used to program the Arduino in Arduino user interface. The entire process takes 60seconds and it helps to maintain personal preventive measures as well as detecting a possible symptomatic person as fever with high temperature which is one of the major symptoms of Covid-19. The device has been tested and works effectively, and it will be very useful for any organization with one or more buildings. It can be positioned at the entrance of buildings to sanitize and scan all staff and visitors against Covid-19

Performance Evaluation of Sand-based Surface flow Constructed wetland in Domestic Wastewater Treatment using Typha Orientalis as Macrophyte

A laboratory-scale free water surface-flow constructed wetland was set up at the Department of Civil Engineering; Ladoke Akintola University of Technology (LAUTECH) Ogbomoso, Nigeria in May 2013 to demonstrate the performance of sand- based constructed wetland, using Typha Orientalis as a viable low-cost efficient treatment option for domestic wastewater from kitchen. The nutrient removal and performance evaluation of the constructed wetland in treatment of kitchen wastewater against retention period of ten days was investigated. During the 10-day retention period, the sand- based constructed wetland set up with Typha Orientalis had improved the wastewater quality significantly as it had reduced 94.9% of Turbidity, BOD5 by 79.0%, NO-3 by 66.7%, 87.9% of SO-4 , 70.24% of Cl-, Conductivity by 70.8% and Magnesium by 80.62%. The pH value and Dissolve Oxygen increased by 28.3% and 64.01% respectively and the initial offensive odour of the raw water was no more noticeable. The final effluent was found to be suitable for non-drinking purposes like crop irrigation and keeping aquatic animals. However, it was noted that a 7- day detention time was optimal for the treatment of domestic wastewater from kitchen. The treatment system was found to be economical, as the cost of construction only was involved and maintenance cost very minimal. It was environmentally friendly as it was free from offensive odour and insect invasion. The prototype scale is recommended for in-situ use, especially for wastewater from kitchen. Keywords: Constructed wetland, Domestic wastewater, Nutrient removal, Retention period, Typha Orientalis

A cross-sectional study on urogenital schistosomiasis in children; haematuria and proteinuria as diagnostic indicators in an endemic rural area of Nigeria

Background: Rapid and accurate diagnosis is necessary for the management of schistosomiasis in endemic areas.Objective: To assess the burden of urogenital schistosomiasis and the diagnostic efficiency of morbidity indicators of the disease in an endemic rural community of Nigeria.Methods: A cross-sectional school-based study was conducted. Urine samples of 487 pupils were screened microscopically for S. haematobium and tested for haematuria and proteinuria using chemical reagent strips.Results: The prevalence and intensity of infection were 57.1% and 45.0 eggs/10 mL urine respectively. Prevalence of infection in male (54.1%) and female (60.3%) individuals showed no significant variation (P>0.05). However, prevalence of infection was age dependent with those in age groups 3-5 and 12-14 years having the least and highest prevalence of infection respectively (P<0.05). Microhaematuria and proteinuria varied significantly with ages of the pupils with least (14.0, 40.0%) and highest (60.0, 80.0%) prevalence recorded in age groups 3-5 and 15-19 years respectively (P<0.05). Proteinuria showed higher sensitivity (80.3%) compared to microhaematuria (73.3%).Conclusion: Schistosomiasis is highly endemic in the study area and the use of microhaematuria and proteinuria for mapping the infected  population prior treatment could be adopted.Key words: Schistosomaisis, haematuria, proteinuria, Nigeri

Evaluation of a hybrid solar power system as a potential replacement for urban residential and medical economic activity areas in southern Nigeria

A hybrid solar power system (HSPS) is an alternate method of supplying electricity that can reduce fuel usage while maintaining power supply security. In this study, the efficiency of HSPS, which consists of Grid Supply (GS), Diesel Power Generation (DPG), Solar-Photovoltaic (SPV), and Battery Storage (BS) systems, was evaluated in two economic activity areas (EAAs) in Southern Nigeria. The cross-sectional research design was used, and the research was based on Behera's energy-led growth theory. Urban-residential and Health were the EAAs considered and chosen using a stratified random sample technique. Southern Nigerian states of Oyo and Lagos provided the samples, which were combined and used for the study. Electricity consumption was calculated using electricity load demand for the two EAAs from 2008 to 2017. For each EAA, an Integrated Renewable Energy Mini/Microgrid Model (IREMMM) based on power load demand and solar irradiation was constructed. Levelized Cost of Electricity (LCOE) (/kWh), and Net Present Cost (NPC) (M) were calculated for one hybrid configuration, SPV-DPG-BS-GS, and two standalone configurations, DPG and SPV-BS. Configurations with SPV integrated had lower LCOEs than DPGs in both EAAs. In Southern Nigeria, solar PV combinations with battery storage provided the highest performance for a hybrid power system. In the medical contexts, a hybrid power system achieves higher overall performance

Multi-site calibration and validation of SWAT with satellite-based evapotranspiration in a data-sparse catchment in southwestern Nigeria

The main objective of this study was to calibrate and validate the eco-hydrological model Soil and Water Assessment Tool (SWAT) with satellite-based actual evapotranspiration (AET) data from the Global Land Evaporation Amsterdam Model (GLEAM_v3.0a) and from the Moderate Resolution Imaging Spectroradiometer Global Evaporation (MOD16) for the Ogun River Basin (20&thinsp;292&thinsp;km2) located in southwestern Nigeria. Three potential evapotranspiration (PET) equations (Hargreaves, Priestley–Taylor and Penman–Monteith) were used for the SWAT simulation of AET. The reference simulations were the three AET variables simulated with SWAT before model calibration took place. The sequential uncertainty fitting technique (SUFI-2) was used for the SWAT model sensitivity analysis, calibration, validation and uncertainty analysis. The GLEAM_v3.0a and MOD16 products were subsequently used to calibrate the three SWAT-simulated AET variables, thereby obtaining six calibrations–validations at a monthly timescale. The model performance for the three SWAT model runs was evaluated for each of the 53 subbasins against the GLEAM_v3.0a and MOD16 products, which enabled the best model run with the highest-performing satellite-based AET product to be chosen. A verification of the simulated AET variable was carried out by (i) comparing the simulated AET of the calibrated model to GLEAM_v3.0b AET, which is a product that has different forcing data than the version of GLEAM used for the calibration, and (ii) assessing the long-term average annual and average monthly water balances at the outlet of the watershed. Overall, the SWAT model, composed of the Hargreaves PET equation and calibrated using the GLEAM_v3.0a data (GS1), performed well for the simulation of AET and provided a good level of confidence for using the SWAT model as a decision support tool. The 95&thinsp;% uncertainty of the SWAT-simulated variable bracketed most of the satellite-based AET data in each subbasin. A validation of the simulated soil moisture dynamics for GS1 was carried out using satellite-retrieved soil moisture data, which revealed good agreement. The SWAT model (GS1) also captured the seasonal variability of the water balance components at the outlet of the watershed. This study demonstrated the potential to use remotely sensed evapotranspiration data for hydrological model calibration and validation in a sparsely gauged large river basin with reasonable accuracy. The novelty of the study is the use of these freely available satellite-derived AET datasets to effectively calibrate and validate an eco-hydrological model for a data-scarce catchment.</p

DNA barcoding of Tribolium castaneum (Coleoptera: Tenebrionidae) from selected states in Nigeria based on mitochondrial DNA sequences

Tribolium castaneum also known as red flour beetle is one of the most important pests of stored grain product with a cosmopolitan distribution in Nigeria and all over the world contributing to food spoilage. The aim of this study was to characterize the T. castaneum by morphometric and molecular analyses. Samples of yam flour with evidence of the red flour beetles present inside were obtained from four locations in Kwara, Kogi, Oyo and Ekiti states in Nigeria. Morphological and molecular identifications of T. castaneum were carried out using standard methods. A dissecting microscope was used to identify the beetles and measurements were taken using ImageJ. Genomic DNA was extracted and checked on 1.5% agarose gel to confirm the presence of DNA. Species-specific primers were used to amplify mitochondrial cytochrome oxidase I (COI) gene of T. castaneum and the PCR amplicon size was also checked on 1.5% agarose. Morphometric measurements showed that the highest mean number (33.00±4.24 mm) of T. castaneum larvae observed was recorded on day 61 in Ilorin and the lowest was in Iwo, Osun state (4.00±0.00 mm) on the same day. The mean of the total body length of larvae from sampling sites was (1.31±0.37 mm) with minimum and (1.63±1.14 mm) maximum lengths respectively. There was no significant difference (p>0.05) between the mean length of the larvae collected from the study locations. Aligned cytochrome oxidase subunit 1 (COI) sequences of 313bp were analyzed. Phylogenetic analysis inferred by maximum likelihood method showed that the T. castaneum sequences analyzed for this study and sequences obtained from GenBank formed a monophyletic group. The molecular and phylogenetic analyses confirmed the presence of a single species of T. castaneum. The results from this study showed low levels of genetic diversity and variability in the studied T. castaneum populations. The observed genetic similarity in T. castaneum could be due to the fact that they were probably from similar origin when compared with those in the GenBank database. However, further studies are needed with more samples to characterize T. castaneum species from stored food grains across Nigeria

Genetic Diversity of West African Honey Bee (Apis ‎mellifera adansonii Latreille, 1804) from Rural and Urban ‎Areas of ‎Kwara State, North-Central Nigeria

Over one third of the world’s crops– including fruits, vegetables, nuts, spices, and oilseed–‎require insect pollination, and human reliance on ‎pollination services by honey bees (Apis ‎mellifera) to promote these crops continues to rise due to increasing demands from growing ‎human ‎populations. Identifying the effects of urbanization on genetic diversity on this ‎pollinating insect is important in the field of bioscience. This study aimed to investigate genetic diversity of A. mellifera in Kwara State, Nigeria, using the random amplified polymorphic DNA (RAPD) marker. ‎Thirty honey bees ‎were simultaneously collected from both rural and urban regions in ‎Kwara state, Nigeria. Samples were morphologically identified using ‎standard methods, ‎genomic DNA isolated and amplified using five RAPD primers. Data collected were ‎analysed using PyElph, ‎ARLEQUIN, and GeneAlEx version 6.501 software. The results ‎showed that the DNA fragment sizes produced per primer varied from 200 to ‎‎3000 bp. Percentages of polymorphic loci amplified by each primer varied from 17.33 to 33.33%. ‎Analysis of unbiased Nei genetic ‎distance values showed that Agbede (rural) and Adewole ‎‎(urban) showed the highest value of unbiased genetic distance (0.073), while ‎Amoyo ‎‎(rural) to Idofian (urban) exhibited the lowest value (0.027). Dendrogram analysis revealed ‎genetically close relationships among the sampled ‎A. mellifera‎ populations. The low level of genetic ‎polymorphisms observed among the honey bee populations in the two ‎regions ‎indicated that there is genetic relatedness among them. This study concluded that RAPD ‎marker is a useful method for ‎understanding population genetic structure of the African honey ‎bees. These results can be used as baseline information for future genetic ‎diversity ‎assessment of honey bees in Nigeria with larger samples. It is therefore recommended that ‎there is a need to safeguard the genetic ‎diversity of A. mellifera‎ to prevent extinction or ‎gradual loss of diversity‎‎‎.    

Intergenerational Community-Based Research and Creative Practice: Promoting Environmental Sustainability in Jinja, Uganda

This article critically reflects on the methodological approach developed for a recent project based in Jinja, Uganda, that sought to generate new forms of environmental knowledge and action utilizing diverse forms of creative intergenerational practice embedded within a broader framework of community-based participatory research. This approach provided new opportunities for intergenerational dialogue in Jinja, generated increased civic environmental engagement, and resulted in a participant-led campaign to share knowledge regarding sustainable biomass consumption. We term this approach intergenerational community-based research and creative practice. We discuss the advantages of this model while also reflecting throughout on the challenges of the approach

Grain and seed protein functionality

Editado por Jiménez-López, José Carlos (CSIC