602 research outputs found
Comparisons of urban and rural heat stress conditions in a hot–humid tropical city
Background: In recent years the developing world, much of which is located in the tropical countries, has seen dramatic growth of its urban population associated with serious degradation of environmental quality. Climate change is producing major impacts including increasing temperatures in these countries that are considered to be most vulnerable to the impact of climate change due to inadequate public health infrastructure and low income status. However, relevant information and data for informed decision making on human health and comfort are lacking in these countries. Objective: The aim of this paper is to study and compare heat stress conditions in an urban (city centre) and rural (airport) environments in Akure, a medium-sized tropical city in south-western Nigeria during the dry harmattan season (January–March) of 2009. Materials and methods: We analysed heat stress conditions in terms of the mean hourly values of the thermohygrometric index (THI), defined by simultaneous in situ air temperature and relative humidity measurements at both sites. Results: The urban heat island (UHI) exists in Akure as the city centre is warmer than the rural airport throughout the day. However, the maximum UHI intensity occurs at night between 1900 and 2200 hours local time. Hot conditions were predominant at both sites, comfortable conditions were only experienced in the morning and evenings of January at both sites, but the rural area has more pleasant morning and evenings and less of very hot and torrid conditions. January has the lowest frequency of hot and torrid conditions at both sites, while March and February has the highest at the city centre and the airport, respectively. The higher frequencies of high temperatures in the city centre suggest a significant heat stress and health risk in this hot humid environment of Akure. Conclusions: More research is needed to achieve better understanding of the seasonal variation of indoor and outdoor heat stress and factors interacting with it in order to improve the health, safety, and productivity of Akure city dwellers
Public Participation in the Local Budgeting Process: Definitions, Impediments, and Remaining Questions
Abstract Despite a great deal of popular rhetoric and scholarly research, there is no universal agreement on which categories of behaviors constitute civic engagement or public participation in the policy process. This paper showcases various definitions, arguing for a more holistic understanding of the phenomena in popular and scientific literature and discussions. Afterward, the research explores impediments to public participation in one area of policy, public budgeting. The paper concludes by discussing some optimistic happenings that have begun to unfold in this arena
EFFECT OF GROUNDNUT CAKE AND SOYA BEANS ON ENHANCED CITRIC ACID PRODUCTION FROM PAWPAW AND ORANGE PEEL BY MUTANTS OF ASPERGILLUS NIGER
This present study was concerned with the biosynthesis of citric acid (CA) with mutant strain of Aspergillus niger using pawpaw and orange peel as substrates by solid state fermentation process. The A. niger strain isolated from spoilt orange was identified, screened for CA production on Czapek-Dox Agar and subjected to mutation by ethidium bromide. The effect of carbon sources, nitrogen sources and substrates were also determined. Among the mutant strains, A. niger PJ-02 A120 was found to be the best mutant that produced citric acid (65.00±0.58f) after 48 hours in Vogel’s medium. The effects of carbon sources (sucrose and glucose) on CA production from each substrate (orange and pawpaw peel) using mutant A. niger PJ-02 was determined and sucrose, the best carbon source was combined with two the nitrogen sources (groundnut cake and soyabeans) to determine the most suitable supplement for CA production. Groundnut cake enhances the production of citric acid while soyabeans was inhibitory. Citric acid was further produced in pawpaw peel and orange peel medium containing sucrose (5 %) groundnut cake (2 %), methanol (1.5 %) and the mutant strain. The orange peel substrates yielded 112.07g/kg of CA while 107.17g/kg was recorded for pawpaw peel when fermented for 5 days at 30°C. The Production of citric acid with mutant Aspergillus niger proved better with orange peel than pawpaw peel when optimized with alcohol.
 
Changes in Vegetation and Rainfall over West Africa during the Last Three Decades (1981-2010)
The decadal variability of rainfall and vegetation over West Africa have been studied over the last three decades, 1981-1990, 1991-2000 and 2001-2010 denoted as 1980s, 1990s and 2000s, respectively. Climate Research Unit (CRU) monthly precipitation and Normalized Difference Vegetation Index (NDVI) from the National Oceanic and Atmosphere Administration (NOAA), all covering the period 1981-2010 have been used. This study aimed to assess the changes in the land surface condition and the spatio-temporal distribution of rainfall over West Africa region. The relationship between rainfall and vegetation indices over this region was determined using Pearson’s correlation. Also, the decadal comparison between rainfall and NDVI over the region was based on the significant t-test and the Pearson’s correlation. Results showed that significant return to wet conditions is observed between decade 1980s and decade 1990s over West Africa, and also during decade 2000s with the exception of central Benin and the western Nigeria. Meanwhile, a regreening of the central Sahel and Sudano-Sahel regions is noted. From 1990s to 2000s, this regreening belt is located in the South and the coastal areas: the Guinea Coast, Sudano-Guinea and western Sahel regions. A northward displacement of this re-greening belt is also detected. Thus, a linear relationship occurs between rainfall and NDVI in the Sudanian savannah region, but it is not the case in the rest of West Africa. This may suggest that the re-growth of vegetation in the Sudanian savannah region may be linked to rainfall supplies. Therefore, re-greening over Sahel region in1990s is related to rainfall recovery. However, this re-greening was not sustained in the decade 2000s due to a slight decrease in rainfall
Investigation and Scaling of Hydrogen Production by Klebsiella sp. ABZ11 for Optimal Yield and the Kinetics of Batch Fermentation Process
The slow metabolism of bacteria at low temperatures affects the catalytic efficiency of enzymes and productivity. This article investigates the use of a psychrotolerant bacteria (Klebsiella sp. ABZ11) for biohydrogen production, yield and scaling at optimal temperature, pH and glucose in a batch fermentation process within a 2-liter bioreactor using Response Surface Methodology (RSM) to report the process performance. The results show 33.5°C, pH 6.75 and 9.15 g glucose as the optimal conditions. Scale-up yielded 137.56 mol/L biohydrogen, 22.13% more than production under optimized conditions. Biomass grew at 0.081/h and doubled in 17 h with 0.71 g cells to reach maximum production. Compared to 0.062/h, 22 h with 0.87 g cells in optimal condition to achieve maximum biohydrogen production. This result shows the potential of biohydrogen production using Antarctic psychrotolerant bacteria at mesophilic temperature
Global impacts of scientific publications by academic staff: a case study of College of Medical Sciences, University of Maiduguri, Nigeria
The impacts of scientific research by an individual or institution are measured using various bibliometric indices such as the h-index and citations index among others. Objective: The present study assessed the global impacts of scientific publications by academic staff of the College of Medical Sciences, University of Maiduguri (CMS-UNIMAID) using selected bibliometric indices. Methodology: The data (demographic data, research experience, and the number of publications) of the 202 academic staff of College of Medical Sciences CMS-UNIMAID were obtained from the records submitted for the 2019/2020 annual appraisal. The h-index, citations index (CI), number of documents (ND), RG score, research interest (RI), citation/item, and citation/year of the staff were extracted from Google Scholar, Publons, ResearchGate, and Scopus using th authors search until 25 December 2020. Staff and publication online visibilities were determined. Descriptive statistics were prepared for all records obtained and subjected to appropriate inferential statistics. Results: The mean age and research experience of the staff were 45.4±9.2 and 13.9±9.6 years, respectively. The majority (p<0.05) of the staff were male (85.1%), had a PhD/Professional Fellowship (61.4%), and were senior academic staff (53.5%). Atotal of 4940 publication entries were submitted for the appraisal. Only 2.5% of the staff were visible on all platforms with staff online visibility of 63.9, 55.5, 15.8, and 5.0% (p<0.05) on Scopus, ResearchGate, Google Scholar, and Publons, respectively. Male staff (68.0%) were more visible (p<0.05) than their female counterparts (40.0%) on Scopus while senior academic staff were more visible (p<0.05) than junior academic staff on all platforms except Publons. Publication online visibility was highest (p<0.05) in Google Scholar (78.4%) and ResearchGate (65.9%) than Publons (28.0%) and Scopus (25.1%). The mean h-index, CI, and ND were 8.3±1.1, 401.8±97.8, and 36.2±4.9, respectively on Google Scholar and 5.0±0.4, 166.4±25.6 and 9.0±0.9, on ResearchGate. Publons showed means h-index, CI, and ND of 5.0±0.3, 77.2±13.7, and 25.6±2.1, respectively while Scopus showed 4.0±1.6, 144.4±95.3, and 14.5±6.2, respectively. In addition, the means RG score and RI were 10.0±0.7 and 113.1±15.4, respectively while the means citation/item and citation/year were 3.9±1.7 and 10.7±6.8, respectively. Conclusions: Low bibliometric indices indicate poor global impact of scientific publications from CMS-UNIMAID. Concerted efforts are required to improve the quality of research and publication through adequate funding, infrastructure, and mentorship among others
Energy consumption and carbon footprint analysis of Fused Deposition Modelling: A case study of RP Stratasys Dimension SST FDM.
It is envisaged and expected that professional engineers, process and product developers plays an active role in the sustainable development of manufacturing activities to overcome the global challenges of depletion of natural resources, environmental pollution and damage to the ecosystems. This however calls for the necessity of the industry to adapt and improve on the various manufacturing processes employed for their products not only to keep up with global competition by reducing its variable costs, but also for the sustainable manufacture of their products. Rapid prototyping is one of the new 3D and additive manufacturing technology available globally. This technology has been viewed as a sustainable technology since it optimises electrical energy demand and promotes zero waste technology. This overstretched hypothesis need to be tested. This work evaluate the direct electrical energy demand in fused deposition modelling FDM machine using the Stratasys Dimension SST FDM as a case study and as a panacea to understudy the electrical energy requirement and carbon footprint for rapid prototyping
Development and Application of Asphalt Bonded Solar Thermogenerator in Small Scale Agroforestry Based Industry
Specific energy based characterization of tool wear in mechanical machining processes
The global trend for energy consumption as a foundational requirement for economic and social development is an increasing
one. Electricity consumption is proportional to the CO2 emitted at the process level and especially for machining processes. The electrical
energy demand during machining can be categorized and modelled as basic energy (energy demand by the machine tool while operating
at zero load) and tip energy (energy for actual material removal – cutting). The tool tip energy is evaluated from the specific cutting energy.
At present limited data exists with regards to the key parameters required for modelling the tip energy. Previous studies and data for
specific energy were based on the normalisation of the total energy demand with the material removal rate and have not investigated the
effect of tool wear. In this work, the impact of tool wear on the specific energy coefficients in machining were studied and modelled. Cutting
tests were performed and tool wear and tool life based on the specific energy coefficient for each wear land value were evaluated. The
study has for the first time provided data on the variation of specific cutting energy for higher tool wear lands and presents vital sensitivity
analysis. With longer cutting time, tool wear increases which leads to higher specific cutting energy and energy consumption during
machining. The specific energy coefficient increased by up to 50% when turning EN8 steel alloy between 2 and 10 passes. This knowledge
is vital information for process planners and could enable energy estimates to be more accurate and realistic with regards to capturing the
impact of tool wear
Serum Iron and Nitric Oxide Production in Trypanosoma brucei Infected Rats Treated with Tetracycline
The effects of tetracycline on serum iron, nitric oxide production, and
haematological parameters in Trypanosoma brucei infected rats were
investigated. T. brucei infected and uninfected rats were treated with
tetracycline intraperitoneally at 10mg/kg body weight. Four rats each
from various groups were treated daily from the first day parasites
were sighted in the blood and continued until the animals died.
Infected rats, treated and untreated, were sacrificed daily for the
serum iron levels and nitric oxide synthase activities. For
haematological parameters, infected and uninfected but treated rats
were sacrificed on days 7 and 12 along with untreated rats. Results
showed that tetracycline brought about a significant reduction in the
serum iron status and a modulation of nitric oxide synthase activity of
T. brucei infected rats. Red blood cell counts, haemoglobin
concentrations, packed cell volumes, white blood cell and platelet
counts were also significantly higher in infected as a result of
treatment with tetracycline. The results from this study suggest that,
tetracycline which has previously been reported as a possible cheap
drug in the management of African trypanosomiasis, probably exerts its
trypanocidal action through reduction in serum iron status, which in
turn modulates nitric oxide synthase activity, thereby reducing the
severity of anaemia in infected rat
- …