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Challenges, Volume 6, Issue 1 (June 2015) , Pages 1-187

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Open AccessArticle
In Vivo Cytogenotoxicity of Electronic Waste Leachate from Iloabuchi Electronic Market, Diobu, Rivers State, Nigeria on Allium Cepa
Challenges 2015, 6(1), 173-187; https://doi.org/10.3390/challe6010173 - 03 Jun 2015
Cited by 5 | Viewed by 2373
Abstract
The human and environmental impact of electronic waste is increasing due to its careless disposal. Cytogenotoxicity of electronic waste from Iloabuchi electronic market, Diobu, Rivers State was investigated using the Allium cepa bioassay comprised of the root elongation and chromosome aberration tests. Leachate [...] Read more.
The human and environmental impact of electronic waste is increasing due to its careless disposal. Cytogenotoxicity of electronic waste from Iloabuchi electronic market, Diobu, Rivers State was investigated using the Allium cepa bioassay comprised of the root elongation and chromosome aberration tests. Leachate samples of e-waste analysed were above maximum permissible limits. Toxicity to root growth of A. cepa was evaluated at concentrations of 5%, 10%, 25%, 50%, and 100% showed root growth inhibition at all concentrations of the samples compared to the control and root growth inhibition was concentration dependent. An effective concentration (EC50) at which root growth amounted to 50 % of control for the sample was 37.5%. Various morphological defects of the onion roots were observed including short, crochet roots, C-tumor roots and severe toxic effects where no growth was observed. In the in vivo genotoxity assay, all samples lowered the frequency of mitotic cells in the meristematic region of the roots at statistically significant levels (P < 0.05) compared to the control and mitotic inhibition was also concentration dependent. There was significant induction of aberrations at all concentrations tested compared to control. The high metal content of the e-waste leachate may be responsible for observed cytotoxicity in A. cepa roots cells. Full article
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Open AccessArticle
Biomass Resource Assessment and Existing Biomass Use in the Madhya Pradesh, Maharashtra, and Tamil Nadu States of India
Challenges 2015, 6(1), 158-172; https://doi.org/10.3390/challe6010158 - 27 May 2015
Cited by 3 | Viewed by 2781
Abstract
India is experiencing energy crisis and a widening gap between energy supply and demand. The country is, however, endowed with considerable, commercially and technically available renewable resources, from which surplus agro-biomass is of great importance and a relatively untapped resource. In the policy [...] Read more.
India is experiencing energy crisis and a widening gap between energy supply and demand. The country is, however, endowed with considerable, commercially and technically available renewable resources, from which surplus agro-biomass is of great importance and a relatively untapped resource. In the policy making process, knowledge of existing biomass use, degree of social reliance, and degree of biomass availability for energy production is unequivocal and pre-conditional. Field observations, documentation, and fill-in sheet tools were used to investigate the potential of biomass resources and the existing domestic, commercial, and industrial uses of biomass in selected Indian states. To do so, a team of field observers/supervisors visited three Indian states namely: Maharashtra (MH), Madhya Pradesh (MP), and Tamil Nadu (TN). Two districts from each state were selected to collect data regarding the use of biomass and the extent of biomass availability for energy production. In total, 471 farmers were interviewed, and approximately 75 farmers with various land holdings have been interviewed in each district. The existing uses of biomass have been documented in this survey study and the results show that the majority of biomass is used as fodder for domestic livestock followed by in-site ploughing, leaving trivial surplus quantities for other productive uses. Biomass for cooking appeared to be insignificant due to the availability and access to Liquefied Petroleum Gas (LPG) cylinders in the surveyed districts. Opportunities exist to utilize roadside-dumped biomass, in-site burnt biomass, and a share of biomass used for ploughing. The GIS-based maps show that biomass availability varies considerably across the Taluks of the surveyed districts, and is highly dependent on a number of enviromental and socio-cultural factors. Developing competitive bioenergy market and enhancing and promoting access to more LPG fuel connections seem an appropriate socio-economic and environmental approach to reduce the use of biomass for indoor cooking and increasing the share of surplus biomass for energy production. Full article
(This article belongs to the Special Issue Bioenergy in the BRICS Countries)
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Open AccessArticle
On Global Electricity Usage of Communication Technology: Trends to 2030
Challenges 2015, 6(1), 117-157; https://doi.org/10.3390/challe6010117 - 30 Apr 2015
Cited by 87 | Viewed by 14873
Abstract
This work presents an estimation of the global electricity usage that can be ascribed to Communication Technology (CT) between 2010 and 2030. The scope is three scenarios for use and production of consumer devices, communication networks and data centers. Three different scenarios, best, [...] Read more.
This work presents an estimation of the global electricity usage that can be ascribed to Communication Technology (CT) between 2010 and 2030. The scope is three scenarios for use and production of consumer devices, communication networks and data centers. Three different scenarios, best, expected, and worst, are set up, which include annual numbers of sold devices, data traffic and electricity intensities/efficiencies. The most significant trend, regardless of scenario, is that the proportion of use-stage electricity by consumer devices will decrease and will be transferred to the networks and data centers. Still, it seems like wireless access networks will not be the main driver for electricity use. The analysis shows that for the worst-case scenario, CT could use as much as 51% of global electricity in 2030. This will happen if not enough improvement in electricity efficiency of wireless access networks and fixed access networks/data centers is possible. However, until 2030, globally-generated renewable electricity is likely to exceed the electricity demand of all networks and data centers. Nevertheless, the present investigation suggests, for the worst-case scenario, that CT electricity usage could contribute up to 23% of the globally released greenhouse gas emissions in 2030. Full article
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Open AccessArticle
Hybrid Life Cycle Assessment of Low, Mid and High-Rise Multi-Family Dwellings
Challenges 2015, 6(1), 98-116; https://doi.org/10.3390/challe6010098 - 30 Apr 2015
Cited by 4 | Viewed by 2944
Abstract
We undertake Life Cycle Assessment (LCA) of the cumulative energy demand (CED) and global warming potential (GWP) for a portfolio of 10 multi-family residences in the U.S. We argue that prior LCA studies of buildings use an inconsistent boundary for processes to be [...] Read more.
We undertake Life Cycle Assessment (LCA) of the cumulative energy demand (CED) and global warming potential (GWP) for a portfolio of 10 multi-family residences in the U.S. We argue that prior LCA studies of buildings use an inconsistent boundary for processes to be included in the supply chain: The operational phase includes all energy use in a building, but supply chains for the production of appliances, equipment and consumables associated with activities done in the building are neglected. We correct this by starting the analysis with an explicit definition of a functional unit, providing climate controlled space, and including processes associated with this functional unit. Using a hybrid LCA approach, the CED for low, mid and high-rise multi-family residences is found to increase from 30, 34, to 39 GJ/m2, respectively. This increase is due to the need for energy-intensive structural materials such as concrete and steel in taller buildings. With our approach, the share of materials and construction of total life cycle energy doubles to 26%, compared with a 13% share that would be obtained with inconsistent system boundaries used in prior studies. We thus argue that explicit definition of functional unit leads to an increase in the contribution of supply chains to building energy life cycles. Full article
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Open AccessTechnical Note
A New Compendium of Soil Respiration Data for Africa
Challenges 2015, 6(1), 88-97; https://doi.org/10.3390/challe6010088 - 27 Apr 2015
Cited by 4 | Viewed by 2151
Abstract
The objective of this paper is to present to the scientific community a new dataset derived from existing literature on soil respiration in Africa. The data has thus been obtained by searching for records in peer review papers and grey literature. The main [...] Read more.
The objective of this paper is to present to the scientific community a new dataset derived from existing literature on soil respiration in Africa. The data has thus been obtained by searching for records in peer review papers and grey literature. The main search engines used are: Scientific Citation Index (SCI) database, ISI Science web and Google scholar. This data description paper has greatly advanced the number of data points on soil respiration in Africa from 4 in 2010 to 62 in 2014. The new data points are culled from 47 peer review publications and grey literature reports. The data lends its self to a lot of possible analytical methods such as correlation analysis, multiple linear regressions, artificial neural network analysis and process base modeling. The overall conclusion that can be drawn here is that this paper has greatly advanced the availability of soil respiration data in Africa by presenting all the available records that before now were only reported in different studies. Full article
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Open AccessArticle
Perspectives of Feedstock Supply for Biomass-Based Energy Plant Development in India: Views from an Expert Survey
Challenges 2015, 6(1), 71-87; https://doi.org/10.3390/challe6010071 - 27 Apr 2015
Cited by 2 | Viewed by 2128
Abstract
Utilization of renewable energy resources is imperative due to energy access, energy security, and energy sustainability coupled with the rising environmental concern. India is one of the largest land mass countries in the world and amply bestowed with biomass resources. Investigations on biomass [...] Read more.
Utilization of renewable energy resources is imperative due to energy access, energy security, and energy sustainability coupled with the rising environmental concern. India is one of the largest land mass countries in the world and amply bestowed with biomass resources. Investigations on biomass supply potential, socio-economic challenges, local people attitudes, current bioenergy markets, and technologies are prerequisite while seeking to develop sustainable energy plants. The study aimed to assess expert attitudes on wood-based energy development in India. This assessment was based on the opinions of Indian Forest Service (IFS) officers who are involved in managing wood-based biomass resources in different parts of the country. The study gave emphasis to the advantages, problems, and directions of the biomass based energy development in the country. The results showed that the development of biomass-based energy plants involves a number of challenges both locally and nationally. In addition, the study also highlighted the possible benefits of developing biomass based energy plants at local and national levels. The outcomes of this study provide useful information to the policy decision makers, energy entrepreneurs, and other stakeholders in the development of biomass based energy in India. Full article
(This article belongs to the Special Issue Bioenergy in the BRICS Countries)
Open AccessArticle
Regional Transport Indicators Used in Sweden for Measurement, Reporting and Verification of CO2 Emissions
Challenges 2015, 6(1), 55-70; https://doi.org/10.3390/challe6010055 - 15 Apr 2015
Cited by 2 | Viewed by 1730
Abstract
Established practice is available as a reference for evaluating sustainable transport and CO2 emissions at national, European and global levels, but comparing corresponding systems at the regional and local levels are more challenging. Therefore, this paper analyses the use of indicators, evaluation [...] Read more.
Established practice is available as a reference for evaluating sustainable transport and CO2 emissions at national, European and global levels, but comparing corresponding systems at the regional and local levels are more challenging. Therefore, this paper analyses the use of indicators, evaluation methods and data availability at local and regional levels for applied policies and measures in transport planning. Sweden is used as a case study. Available data show that total surveys (e.g., vehicle registry data), sample surveys (e.g., interviews) or modelling can be used to develop transport indicators, and that either generated (volume generated in the area) or performed (volume in the area) traffic and transportation is estimated. However, there are limitations with all methods and the design of evaluations needs careful consideration in order to reflect changes in local and regional transport systems and to relate those changes to specific measures and policies. In most cases, survey methods need to be used in order to follow up the most common indicators. All evaluation methods need to be complemented with analyses of a baseline to determine additionality and also potential rebound effects need to be considered, which requires the application of a wider systems perspective. Full article
Open AccessArticle
Indian Farmers’ Perceptions and Willingness to Supply Surplus Biomass to an Envisioned Biomass-Based Power Plant
Challenges 2015, 6(1), 42-54; https://doi.org/10.3390/challe6010042 - 10 Apr 2015
Cited by 9 | Viewed by 2661
Abstract
The main objectives of this socio-technical study are to investigate the Indian farmers’ biomass production capacities and their perceptions and willingness to supply their surplus biomass to fuel an envisioned biomass-based power plant in three selected Indian states: Maharashtra, Madhya Pradesh and Tamil [...] Read more.
The main objectives of this socio-technical study are to investigate the Indian farmers’ biomass production capacities and their perceptions and willingness to supply their surplus biomass to fuel an envisioned biomass-based power plant in three selected Indian states: Maharashtra, Madhya Pradesh and Tamil Nadu. For doing so, 471 farmers (about one-third from each state) have been interviewed in the field with info-sheet filled in by the field investigators. The farmers from all of the states appeared very much willing to sell their surplus biomass directly to a power plant. The farmers seem to depreciate the involvement of a middleman in the biomass procurement process. The farmers, however, appeared to highly appreciate a community-based association to regulate the biomass prices, with varying perceptions regarding government intervention. The majority of the farmers perceived the establishment of a biomass-based power plant in their region with positive economic outcomes. The farmers identified several barriers to supply biomass to a power plant where transportation logistics appeared to be the main barrier. The study recommends considering biomass collection, storage and transportation logistics as a fundamental segment of any envisioned investment in a biomass-based power plant. Biomass processing, such as pelletization or briquetting is recommended for efficient transportation of biomass at longer distances to reduce the transportation costs. The study further encourages the establishment of a farmers’ association aimed at collecting and selling biomass in agriculture areas predominant for small land holdings. Full article
(This article belongs to the Special Issue Bioenergy in the BRICS Countries)
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Open AccessArticle
The Italian University Habilitation and the Challenge of Increasing the Representation of Women in Academia
Challenges 2015, 6(1), 26-41; https://doi.org/10.3390/challe6010026 - 10 Mar 2015
Cited by 4 | Viewed by 2673
Abstract
Increasing the representation of women in academia is a priority challenge in higher education policy. This study uses data from the Italian University habilitation competition in 2012 to test whether this national, standardized and quantitative assessment of researchers contributed to improving the situation. [...] Read more.
Increasing the representation of women in academia is a priority challenge in higher education policy. This study uses data from the Italian University habilitation competition in 2012 to test whether this national, standardized and quantitative assessment of researchers contributed to improving the situation. The proportion of female applications (on the whole about 36%) was in many fields higher than the reported proportion of female University professors (27%, 2010), but lower than the proportion of female researchers (2010) in Italy (45% and 51% for researchers with and without a permanent position, respectively). There was still a gap between the proportion of female applications at the associate (on average 39%) and full professor level (29%). A similar gap was also present between scientific disciplines and the humanities. Average success rates of female applications (41.2%) were on the whole lower than those of male applications (43.9%), but in most fields these differences were not significant. Overall, it is generally much lower proportion of female applications rather than their lower success rate that perpetuates the low proportion of female academics in Italy. More effort is needed to support female researchers in choosing and pursuing an academic career. Full article
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Open AccessConcept Paper
Retrofitting Precincts for Heatwave Resilience: Challenges and Barriers in Australian Context
Challenges 2015, 6(1), 3-25; https://doi.org/10.3390/challe6010003 - 16 Jan 2015
Cited by 4 | Viewed by 2655
Abstract
As the frequency and intensity of heatwaves are growing in Australia, strategies to combat heat are becoming more vital. Cities are exposed to urban heat islands (UHIs) due to excess urbanisation. In this study, a definition of urban heatwave (UHW) is conceptualised to [...] Read more.
As the frequency and intensity of heatwaves are growing in Australia, strategies to combat heat are becoming more vital. Cities are exposed to urban heat islands (UHIs) due to excess urbanisation. In this study, a definition of urban heatwave (UHW) is conceptualised to investigate the combined impacts of heatwaves and UHIs. To quantify the negative impacts of UHW, indicators—such as excess morbidity, electricity and water consumption—are considered. The intensity of UHWs is calculated using the unit of excess heat factor (EHF), developed by the Australian Bureau of Meteorology. EHF enables the comparability of UHWs in different geographical locations. Using the indicators and the intensity of UHWs, a calculation method to quantify heatwave resilience at a precincts scale is proposed. The study summarises the assumed influential factors of precinct heatwave resilience based on the existing literature and propose a “cool retrofitting toolkit” (CRT). CRT creates the framework to assess the adaptation to and mitigation of UHWs available to retrofit existing precincts, and to evaluate potential retrofitting strategies in terms of energy and carbon efficiency, financial affordability and perceived acceptability by population. This study illuminates the importance of climate, function, built environment and population characteristics-conscious retrofitting. Full article
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Open AccessEditorial
Acknowledgement to Reviewers of Challenges in 2014
Challenges 2015, 6(1), 1-2; https://doi.org/10.3390/challe6010001 - 08 Jan 2015
Viewed by 1605
Abstract
The editors of Challenges would like to express their sincere gratitude to the following reviewers for assessing manuscripts in 2014:[...] Full article
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