1,856 research outputs found
Development of framework for aluminum recycling management using Analytical Hierarchy Process
This research focuses on the establishment of a new framework an efficient used aluminum
cans management system in the context of sustainable development based on Melaka
situations. The Analytical Hierarchy Process (ARP) a multi-criteria decision malting
analys is was evaluated using a quantitative data generated from survey on solid waste
management company in Melaka (SWM Environment Sdn Bhd and Tzu chi Foundation).
Quantitative weightings from the AHP were used to identify alternative systems that have
similar outcomes in meeting the aluminum cans management objective were evaluated
based on multiple criteria comprising technology, economics, quality, environment and
management which were used to validate the appropriateness of the three aluminum cans
management models which are recycling model, reuse and disposal model that were used.
The result showed that reuse model (37.0 %) and recycling model (37.0 %) ranked first
and lastly disposal model (26.0 %). The present research finding can be used to optimize
aluminum cans management practices in Melaka with respect to the criteria that were
evaluated
Etude physicochimique de l’huile essentielle de Ruta Chalepensis L. de Tlemcen, Algérie
Ruta chalepensis L. (Rutacée), est une plante aromatique médicinale encore utilisée dans la médecine traditionnelle de nombreux pays comme laxatif, antiinflammatoire, analgésique, antipasmodique, abortif, antiépileptique, emménagogue et pour le traitement de pathologies cutanées. Des screening phytochimiques ont mis en évidence la présence de coumarines en sus d’alcaloïdes et ont donné la composition chimique de l’huile essentielle de la partie aérienne de la plante provenant de différents pays. Ce travail a porté sur la composition chimique de l’huile essentielle de la plante provenant de l’Algérie, qui n’a jamais fait l’objet de publication. Les analyses ont été réalisées par chromatographie en phase gazeuse (CG) et CG – spectrométrie de masse (SM). 20 composés représentant 64.66 - 93.99% de l’huile essentielle ont été identifiés et, comme composé majoritaire le 2-undécanone (20.40 - 82.74%). L’étude des variations du rendement, des propriétés physicochimiques et de lacomposition chimique de l’huile essentielle a été réalisée en fonction de la partie de la plante étudiée, la période et le lieu de cueillette de la plante. Les résultats ainsi obtenus ont montré l’extrême variabilité du rendement, des propriétés physicochimiques et de la composition.Mots-clés : Ruta chalepensis, huile essentielle, composition chimique, chromatographie en phase gazeuse, spectrométrie de masse, chemotype, 2- undécanone
Exploring double skin façade as strategy for achieving thermal comfort in proposed mixed use office complex Kano, Nigeria
Thermal comfort can be defined as a state of mind which a human feels neither too hot nor too cold. Thermal discomfort in the case of hot humid climates, becomes a great threat to our livelihood and thermal comfort in offices in general. The ability of designers to harness and use the building envelope make life much better and livable is of great importance. This research seeks to use Double skin façade as a strategy for improving indoor thermal comfort by testing the air gap between the double skins. Climate and Weather readings were obtained and used to simulate and check the effect of Double skin façade in improving indoor thermal comfort in office complex. Double skin facade has been suggested by many researchers as a possible alternative technique for improving indoor thermal comfort. The double skin facade study in this research involved computer simulation using Emissions Control Optimization TEChnology (ECOTEC). The result of the final base case model shows that double skin façade can increase the indoor thermal comfort in a building and the wider the air gap, the higher the thermal comfort by showing the hours of comfort and discomfort to the simulated office building. The other important factor is that it can continuously induce the flow of natural ventilation, regardless of the available wind outside of the office complex building. This effect is significant toward improving the thermal comfort performance in the office complex through passive natural ventilation
Sukuk: Literature Review
Abstract. At the heart of a global financial crisis triggered since 2008, Islamic finance has been seen as an alternative less affected by the global crisis to cover the financing and investment needs and bringing a new vision that involves sharing of losses and gains and thus prohibit the notion of the interest rate. With the emergence of the concept of Islamic finance a new market has emerged known as sukuk market where its last ones play the role of bonds. These financial instruments have been able, like conventional bonds, to constitute a reliable investment alternative for both companies and governments that want to conduct their business within a framework that respects the precepts of the Sharia. The purpose of this article is to understand the concept and the mechanism of these obligations and to present a review of the literature on sukuks.Keywords. Sukuk, Islamic Finance, Bonds, Financial Instruments.JEL. A10, H12
Developing human capital in Africa: carving a role for human resource professionals and practitioners
Africa is a continent with remarkable economic potential yet the least developed largely due to its inadequate human capital to transform this potential into social and economic development. The focus on provision of classroom education as the cornerstone of human capital development in Africa has not produced the desirable outcomes expected. We see an important role in this process within the workplace, and thus argue that the role of Human Resource (HR) professionals in Human Capital development in Africa deserves serious attention. The paper outlines why and how HR professionals can contribute to the development of Africa's human capital. It also highlights the challenges HR professionals will face and the competencies they will need to address the challenges. The paper concludes with suggestions for further research
Boosting the Performance of Solar Cells with Intermediate Band Absorbers The Case of ZnTe:O
[EN] This work reports on modeling IB (intermediate band) solar cells based on ZnTe:O semiconductor and determination of their photovoltaic parameters using SCAPS (solar cell capacitance simulator) software. A comparative study between photovoltaic performance of ZnTe and ZnTe:O based solar cells has been carried out. It has been found that the energy conversion efficiency ¿, short-circuit current density Jsc, EQE (external quantum efficiency) and FF (fill factor) increased with increasing oxygen doping concentration Nt up to the shallow acceptor density NA and decreased when Nt was higher than NA. The open circuit-voltage Voc remained constant for Nt lower than the acceptor doping concentration NA and decreased for Nt higher than NA. The increase of ¿, Jsc and FF is due to the fact that IB is fully empted, so sub-bandgap photons can be absorbed by hole photoemission process from the VB (valence band) to the IB. The decrease of ¿, Jsc, EQE and FF is attributed to overcompensation for the base doping NA making electron photoemission process from IB to the CB (conduction band) maximized. This indicates that there is a competition between oxygen doping and intrinsic acceptor defects. The optimal concentrations of oxygen and shallow acceptor carriers were found to be Nt ¿ 1015 cm-3 and NA ¿ 1014 cm-3. The corresponding photovoltaic parameters were ¿ = 41.5%, Jsc = 31.2 mA/cm2, Voc = 1.80 V and FF = 75.1%. Finally, the EQE spectra showed a blue shift of absorption edge indicating that the absorption process is extended to the sub-bandgap photons through IB.Skhouni, O.; El Manouni, A.; Bayad, H.; MarÃ, B. (2017). Boosting the Performance of Solar Cells with
Intermediate Band Absorbers The Case of ZnTe:O. Journal of Energy and Power Engineering. 11:417-426. doi:10.17265/1934-8975/2017.06.007S4174261
Informing aerial total counts with demographic models: population growth of Serengeti elephants not explained purely by demography
Conservation management is strongly shaped by the interpretation of population trends. In the Serengeti ecosystem, Tanzania, aerial total counts indicate a striking increase in elephant abundance compared to all previous censuses. We developed a simple age-structured population model to guide interpretation of this reported increase, focusing on three possible causes: (1) in situ population growth, (2) immigration from Kenya, and (3) differences in counting methodologies over time. No single cause, nor the combination of two causes, adequately explained the observed population growth. Under the assumptions of maximum in situ growth and detection bias of 12.7% in previous censuses, conservative estimates of immigration from Kenya were between 250 and 1,450 individuals. Our results highlight the value of considering demography when drawing conclusions about the causes of population trends. The issues we illustrate apply to other species that have undergone dramatic changes in abundance, as well as many elephant populations
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