Challenges2015, 6(2), 271-281; doi:10.3390/challe6020271 (registering DOI) - published 27 November 2015 Show/Hide Abstract
Abstract: Estimation and forecast of groundwater recharge and capacities of aquifers are essential issues in water resource investigation. In the current research, groundwater recharge and the recharge coefficient were determined through a case study using empirical methods applicable to the tropical zones. The related climatological data between January 1983 and December 2014 were collected in Ogun-Oshun River Basin Development Authority (OORBDA), Ogun State, Nigeria. The results showed that groundwater recharge was 194.7 mm per year, evapotranspiration was 1296.2 mm per year, and the recharge coefficient was 20.2% for the study area. The result showed that about 11% of rainfall infiltrated the aquifer, 73% was loss to evapotranspiration, and 36% ended up as run-off. Correlation between climatic parameters and groundwater recharge showed the highest correlation between recharge and rainfall. Temperature, humidity, solar radiation and evapotranspiraton were at the 0.01 significance level, and the results of linear regressions proved that precipitation has a significant effect (with R2 = 0.983) on estimated recharge.
Abstract: The transportation sector is severely correlated with major problems in environment, citizens’ health, climate and economy. Issues such as traffic, fuel cost and parking space have make life more difficult, especially in the dense urban environment. Thus, there is a great need for the development of the electric vehicle (EV) sector. The number of cars in cities has increased so much that the current transportation system (roads, parking places, traffic lights, etc.) cannot accommodate them properly. The increasing number of vehicles does not affect only humans but also the environment, through air and noise pollution. According to EPA, the 39.2% of total gas emissions in 2007 was caused by transportation activities. Studies have shown that the pollutants are not only gathered in the major roads and/or highways but can travel depending on the meteorological conditions leading to generic pollution. The promotion of EVs and the charging stations are both equally required to be further developed in order EVs to move out of the cities and finally confront the range problem. In this work, a wind resource and a GIS analysis optimizes in a wider area the sitting of wind based charging stations and proposes an optimizing methodology.
Abstract: There is widespread contamination of the environment of the Niger Delta, which may include enhanced background levels of naturally occurring radioactive materials (NORM) due to oil production and rapid urbanization activities. Sediments and seafood from the Bonny estuary, Niger Delta, were collected for the purpose of determining baseline data on artificial and natural radioactivity and estimation of effective doses for the public due to ingestion of seafood from the study area. The highest and lowest activity concentrations were reported for 40K and 137Cs in both sediments and fish samples of the Bonny estuary. There was some evidence of spatial variability in the 40K and 137Cs data, with the latter being the likely result of dredging. Other radionuclides were not significantly different between sites impacted by industrial activities or not. Activity of radionuclides measured in the sediments of the study area were higher than reported elsewhere in the Niger Delta and Nigeria and higher than reported global averages by UNSCEAR. The total highest activity concentration in all fish species of gamma emitting radionuclides was observed for 40K, followed by 238U, 232Th and 226Ra, respectively, while 137Cs had the lowest activity concentration. However, 210Po activities were the most important in terms of dose contribution. Consumption of molluscs at typical rates could result in doses exceeding 1 mSv·y−1. Although this baseline data may not be conclusive on prevailing trends in radioactivity in the study area, higher consumption rates of the species studied may have public health consequences due to effects of low dose ionising radiation.
Challenges2015, 6(2), 229-243; doi:10.3390/challe6020229 - published 23 September 2015 Show/Hide Abstract
Abstract: Introduction: Diarrhea remains the second leading cause of death among children under five years globally. Nearly one in five child deaths, about 1.5 million each year, are due to diarrhea. It kills more young children than Acquired Immunodeficiency Syndrome (AIDS), malaria and measles combined. World Health Organization has accordingly underlined the need for epidemiological surveys of infantile diarrhea in all geographical areas. The main research objectives were to estimate the prevalence of diarrhea and identify factors associated with diarrheal diseases in Tiko city in Cameroon. Method: The present study was a cross-sectional community household survey which was conducted in Tiko town from 1st to 31st of August 2012. With the use of a questionnaire, a total of 602 households that had at least one child under five years of age were interviewed. Mothers/caregivers were questioned on the morbidity of diarrhea and the logistic regression model was employed to examine the determinants of childhood diarrhea. Both univariable and multivariable data analysis was performed using SPSS version 16.0. Results: The results of this study showed that the prevalence of diarrhea was 23.8% and children under 24 months were highly affected. We found children using the main toilet and other types of toilet facilities such as bushes, diaper, and streams (OR: 0.194; p < 0.001, 95% CI) and usage of narrow-mouth container for storage of drinking water (OR: 0.492; p < 0.001, 95% CI) less likely to suffer from diarrhea. In contrast, higher rates of diarrhea prevalence were seen in children from households with two or more siblings (OR: 1.222; p < 0.001, 95% CI) and whose mothers/caregivers never had the knowledge of safe sources of drinking water (OR: 1.849; p < 0.01, 95% CI). Conclusion: Childhood diarrhea is a public health problem in Tiko city. Hence, interventions aimed at reducing the prevalence should take into consideration the integration of family planning activities in the prevention of childhood diarrhea and the deployed of health personals to educate the community to adopt a hygienic behavior. Future research on the topic should be qualitative inquiry to complement the quantitative nature of this study.
Abstract: An exercise has been prepared and executed to simulate international interactions on policies related to greenhouse gases and global albedo management. Simulation participants are each assigned one of six regions that together contain all of the countries in the world. Participants make quinquennial policy decisions on greenhouse gas emissions, recapture of CO2 from the atmosphere, and/or modification of the global albedo. Costs of climate change and of implementing policy decisions impact each region’s gross domestic product. Participants are tasked with maximizing economic benefits to their region while nearly stabilizing atmospheric CO2 concentrations by the end of the simulation in Julian year 2195. Results are shown where regions most adversely affected by effects of greenhouse gas emissions resort to increases in the earth’s albedo to reduce net solar insolation. These actions induce temperate region countries to reduce net greenhouse gas emissions. An example outcome is a trajectory to the year 2195 of atmospheric greenhouse emissions and concentrations, sea level, and global average temperature.
Abstract: The transition from the era of massive renewable energy deployment to the era of cheaper energy needed has made scientists and developers more careful with respect to energy planning compared with a few years ago. The focus is—and will be—placed on retrofitting and on extracting the maximum amount of locally generated energy. The question is not only how much energy can be generated, but also what kind of energy and how it can be utilized efficiently. The waste heat coming from wind farms (WFs) when in operation—which until now was wasted—was thoroughly studied. A short-term forecasting methodology that can provide the operator with a better view of the expected heat losses is presented. The majority of mechanical (due to friction) and electro-thermal (i.e., generator) losses takes place at the nacelle while a smaller part of this thermal source is located near the foundation of the wind turbine (WT) where the power electronics and the transformers are usually located. That thermal load can be easily collected via a working fluid and then be transported to the nearest local community or nearby agricultural or small scale industrial units using the necessary piping.