363 research outputs found

    Novel nonimaging solar concentrator for portable solar systems for developing countries

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    Portable solar chargers have been gaining popularity as a new technology to help increase electrification in rural areas in developing countries. It is a fast developing industry aiming to produce a low-cost solution for the application of off-grid solar lighting and charging of small devices to be used by the poorest and most vulnerable of society. Solar concentrators are proposed as an add-on to help further reduce costs, to increase light-output hours and to reduce charging time. So far, no suitable concentrator designs have been proposed. This paper presents a novel concept for the design of a static nonimaging concentrator, suitable for portable solar systems for developing countries. The novel concentrator design is compared with existing concentrators and its suitability for portable solar chargers, as well as its potential for further improvement, are highlighted

    Using illustrations to make decisions on the most appropriate qualitative research methodology: the industry 4.0 scenario.

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    Industry 4.0 is viewed as a complex scenario. This complex scenario could be interpreted using illustrations such as sketches or drawings. Ideally, sketches and drawings are useful in illustrating complexity and multiple abstracts from observed social reality. The use of illustrations allows novice qualitative researchers to explore observed social reality in depth with less linear insight. However, few scholars mention the use of illustrations at the research planning stage because most sketches and drawings have been used as tools during data collection, merely to understand an interviewee's perspective. Therefore, this article aims to demonstrate the use of illustrations as a tool to facilitate the research process from problem identification to the selection of the qualitative research methodology. Five specific purposes of illustration that significantly contribute to the body of knowledge for effective decision making and are useful tools in delivering information are demonstrated in this article. Based on the illustrations demonstrated in this article, the most appropriate qualitative research methodology is the case study. Overall, the proposed use of illustrations can assist a novice qualitative researcher in determining the appropriate epistemological and ontological stances - as well as their methodology and method - more effectively

    Building integrated photovoltaics: the journey so far and future.

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    The road to decarbonization has led to the exploration of sustainable energy sources for domestic and industrial use. Various nations have shown commitment and, hence, set ambitious targets, with the overall aim of cutting down greenhouse gas (GHG) emissions across the board. The fight against climate change seems to be intensifying, partly due to the visible signs of environmental hazards and threats to human life and the ecosystem. Environmental policies, behavioural changes and complex decisions have been taken in various sectors to ensure set targets are met

    Distribution power loss minimization via distributed generation, capacitor and network reconfiguration

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    This paper presents a solution to solve the network reconfiguration, DG coordination (location and size) and capacitor coordination (location and size), simultaneously. The proposed solution will be determined by using Artificial Bee Colony (ABC). Various case studies are presented to see the impact on the test system, in term of power loss reduction and also voltage profiles. The proposed approach is applied to a 33-bus test system and simulate by using MATLAB programming. The simulation results show that combination of DG, capacitor and network reconfiguration gives a positive impact on total power losses minimization as well as voltage profile improvement compared to other case studies

    Public-private partnership in Ghana's solar energy industry: the history, current state, challenges, prospects and theoretical perspective.

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    Public Private Partnerships (PPPs) have been used as a viable tool to accelerate infrastructural development in many countries. In recent years, the repercussions of climate change have heightened the need to adopt cleaner energy sources such as solar. Ghana has attempted investments in solar energy for obvious advantages such as ensuring energy security, cost advantage and expansion of rural electrification. PPPs have been adopted in various sectors of Ghana's economy including transport, construction, education, energy and health but the extent of success is arguable. This paper throws light on the history, current state, the challenges and prospects of the solar sector in Ghana. Issues such as accountability and transparency, tensions due to land litigation, politicisation of PPPs and poor bargaining abilities due to low knowledge of PPP agreements are established in this paper as hindrances to PPPs in Ghana. Indeed, Ghana has a huge prospect for solar energy and if PPPs are treated as a ‘Game’ of fairness or with the ‘Parito Optimality’ notion rather than with an ‘altruistic incline’, investor confidence may potentially rise. It is also recommended that, the current national policy on PPP under Ghana's Ministry of Finance and Economic Planning (MOFEP) must be enhanced and implemented fully in order to boost investor confidence in the solar sector

    Design method for nonimaging solar photovoltaic concentrators using genetic algorithms.

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    Off-grid solar chargers are one of the ways forward to achieve universal access to affordable, reliable, sustainable and modern electricity. To achieve this goal, the sustainability aspect of the solar chargers must be further improved. Nonimaging, static solar photovoltaic (PV) concentrators reduce the amount of PV material and thus the embodied energy and greenhouse gas emissions of the solar PV panel, improve its recyclability and reduce the use of hazardous chemicals during its manufacturing, recycling and disposal stages. A novel nonimaging solar PV concentrator named circular rotational square hyperboloid (CRSH) was recently proposed for portable solar systems for developing countries. To further reduce the material usage and production time of the concentrator while achieving an optical concentration ratio above 3x within the angles of incidence of ± 40°, the parameters of the design were optimised using genetic algorithms. The optimisation parameters are discussed and the influence of the objective function on the optimised design is presented. The genetically optimised circular rotational square hyperboloid (GOCRSH) concentrator shows an improved gain-to-volume ratio compared to the CRSH and to several nonimaging solar photovoltaic concentrators proposed for building integrated concentrated PV

    Modeling and simulation of heterojunction solar cell; determination of optimal values.

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    A heterojunction solar cell of ZnSe/ZnO/CIGS/Si structure has been simulated in order to determine the optimal values. The performed modeling and Simulation is used to get an idea and identify the optimal values that can be use in the manufacturing process, and the values obtained in this simulation presented an electrical parameters using Solar Cell Capacitance Simulator (SCAPS). In this study, the influence of absorber or wafer thickness and doping concentration were varied on the solar cell device and the following optimal values were obtained; Current density (Jsc)=35.0833SmA/cm2, Open circuit voltage (Voc)=0.S339V, Fill Factor (FF) =S5.45%, and an efficiency (η)=25%. The range of doping concentration (lx1012 to lx1020 cm−3). These variations lead to the achievement of 25% efficiency of the heterojunction solar cell and the optimal values shows a promising performance that the manufacturers can adopt

    Polymer nanocomposites and related legal issues: an overview.

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    Manipulation of engineered nanomaterials (ENMs) to develop different consumer and industrial products are the preferred choice in modern day industrial production due to their unprecedented, but diversified promises and prospects. The researchers claimed in 2006 that the NMs were in a stage where plastic was in the 1960s. This analogy was made to indicate the potential wide use of the NMs in consumer and industrial products. Burgeoning research has been carried out in almost every corner of the world to explore and exploit the prospects of ENMs. Application of nanoparticles (NPs) into polymer matrix materials have also been tested, and dramatic changes in the mechanical, thermal, electrical, and diffusion properties to the properties of the host polymers were observed. The polymer nanocomposites (PNCs) are undoubtedly very prospective and it can be anticipated that PNCs will widely be used in the automotive industry to replace the metal accessories and to reduce CO2 emissions. However, in order to do so, it is crucial that the manufacturers handle different socio-legal and regulatory issues around the ENMs and PNCs carefully. This record only contains an introduction to the chapter, the full chapter is available from: https://doi.org/10.1016/B978-0-12-811033-1.00026-

    Eye-tracking assistive technologies for individuals with amyotrophic lateral sclerosis

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    Amyotrophic lateral sclerosis, also known as ALS, is a progressive nervous system disorder that affects nerve cells in the brain and spinal cord, resulting in the loss of muscle control. For individuals with ALS, where mobility is limited to the movement of the eyes, the use of eye-tracking-based applications can be applied to achieve some basic tasks with certain digital interfaces. This paper presents a review of existing eye-tracking software and hardware through which eye-tracking their application is sketched as an assistive technology to cope with ALS. Eye-tracking also provides a suitable alternative as control of game elements. Furthermore, artificial intelligence has been utilized to improve eye-tracking technology with significant improvement in calibration and accuracy. Gaps in literature are highlighted in the study to offer a direction for future research

    Upgrading biogas to biomethane by use of nano-structured ceramic membranes.

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    In order to meet the demands of growing economies while considering environmental implications, the use of clean and renewable sources of energy has increasingly become of interest. Biogas utilisation is a means by which these rising needs can be met. This involves the use of waste materials; which are deposited on a daily basis by agriculture, sewage, household, to produce energy that may be used for heating, electricity, transportation and other daily needs. This paper would look into the use of nano-structured ceramic membranes for the upgrading of biogas to a high value fuel that can be used for a variety of purposes. The use of membranes offers great advantages including low running costs, high efficiency and the elimination of the need for phase change of the gas. Experiments were carried out using membranes of different pore sizes (15nm, 200nm and 6000nm) to ascertain which would be the most suitable for use in terms of permeability and yield of product gas. The 15nm membrane showed the greatest exit flow of methane compared to carbon dioxide and a mechanism approaching an ideal knudsen regime. Taking into account the effect of molecular weight and viscosity, these results show that the smallest membrane pore size of 15nm had a greater impact on the flow mechanism and thus improvement can be made by modification of the membrane to achieve a mechanism of surface diffusion of the particles
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