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AbstractHeterojunction CdS/CdTe thin film solar cells were fabricated with a superstrate structure consisting of the successive layers: soda lime glass/ITO/CdS/CdTe/back contact. ZnTe:Cu films were deposited on the back surface of the CdTe layer presenting as ohmic back contact. The substrate was soda lime glass coated with ITO films by rf magnetron sputtering serving as the transparent front contact. A thin layer of CdS with thickness about 80nm was applied by chemical bath deposition. Close-spaced sublimation of the CdTe films was accomplished by placing a CdTe source in a close proximity (6mm) to the substrate in vacuum chamber with low pressure about 3×10-2 mbar. The source was heated to 550 ∘C and the substrate to 450 ∘C. This arrangement causes Cd and Te to sublime from source and diffuse to the substrate. The fabricated cells were investigated using current-voltage (I-V) in the temperature range 20-300K under a standard AM1.5 illumination in order to define the transport mechanism in the heterojunction. Tunnelling enhanced interface recombination has been found to dominate carrier transport mechanism in the junction at all investigated temperatures.

Abstract: The free but intermittent sources of energy such as photovoltaic and wind energy has become more popular nowadays. The installation of this type of power source usually requires a secondary power source, often the energy storage system such as battery to smoothen power output over time. In this article, we introduce, an alternative energy storage system, an organic-electrolyte redox flow battery (RFB), which uses anthraquinone-2-sulfonic acid (AQS) and 1,2-benzoquinone-3,5-disulfonic acid (BQDS) as the electrolytes. The membrane is coated with Vulcan carbon using an ultrasonic spray technique allowing for higher current density. The polarization curve of this system has shown that the RFB with organic AQS and BQDS has impressive amount of energy density, and can deliver the maximum current density up to 45 mA/cm 2 and the maximum power density up to 4 mW/cm 2 . At 5 mA/cm 2 current density, the power delivery has the current efficiency and energy efficiency of 96% and 48%, respectively.

AbstractA two-stage thermophilic fermentation for hydrogen and methane production from wastewater of cassava rice and corn starch at different concentration (5,10 and 15g/L) was studied. The hydrogen production from cassava starch at concentrations of 5g/L gave the highest hydrogen yield and followed by cassava starch at a concentration 10g/L, rice starch at concentrations of 15g/L. The hydrogen and methane yields from cassava starch processing wastewater by two-stage was 81.5 L H2 kgCOD-1 and 310.5 L CH4 kgCOD-1, respectively with total energy yield of 13363kJ kgCOD-1. Mixed hydrogen and methane (biohythane) production was 9.51 L biogas l-1 with containing of 55% CH4, 11% H2 and 34% CO2.

AbstractThis paper presents a study on the burning of oil palm empty fruit bunch and palm kernel shell in a fluidized-bed combustor using alumina sand as the bed material to prevent bed agglomeration. During 60-h combustion testing, the biomasses were burned at similar heat input to the combustor (200 kWth) with excess air of 40%. SEM/EDS analyses were performed to investigate the time-domain changes in the alumina grain morphology and elemental composition of the grain coating. Composition of the used/reused bed material and that of PM emitted from the combustor were determined by a XRF method at different operating times. No features of bed agglomeration were found during the entire tests. However, physical and chemical properties of the bed material underwent substantial changes with time.

AbstractAnaerobic co-digestion of canned seafood wastewater (CSW) with glycerol waste (GW) and wolffia arrhiza (WA) for methane production was investigated. Methane yields from anaerobic co-digestion of CSW with 1%GW, CSW with 1%GW and 5%WA, CSW with 1%GW and 10%WA and CSW with 1%GW and 15%WA were 577, 789, 545 and 474 mL CH4/g VS-added, respectively. Methane production from CSW with 1%GW and 5%WA increased approximately 4-fold when compared with CSW alone (278 mLCH4/g VS-added). Co-digestion of CSW with 1% GW and 5% WA was the best condition and gave the maximum methane production of 8.8 m3 CH4/m3 mixed wastewater and 96.8% biodegradability. The maximum methane production rate and yield were 3.71 L CH4/L-reactor.day and 858 mL CH4/g VS-added (352 mLCH4/g COD-removed) at OLR of 4 g COD/L. day in UASB reactor. The methane composition in biogas was 62.3%. The Monod, Modified Stover–Kincannon and Grau second-order models were used to explain the performance of UASB reactor. The results showed that the kinetic coefficient of the Modified Stover–Kincannon model could explain the performance of UASB reactor in term of COD removal efficiency and microbial growth by having the regression coefficient (R2) as 0.987.

AbstractThe aim of this research is to use medium ammonia concentrated latex mixed in mortar for developing the strength and thermal insulation properties. The concentrated latex to cement ratios (P/C) are fixed at 0.000, 0.025, 0.050, 0.075, 0.100, 0.125 and 0.150 by weight. Cement to sand ratio is maintained at 1: 2.75. Water to cement ratio is 0.50 (not include water content in concentrated latex). The mortar samples are cast for testing the properties followed the ASTM standard. From the results, it is found that the increase of concentrated latex affects in decreasing of density, elongation, compressive strength, bending strength and coefficient of thermal conductivity. For rate of water absorption, it decreases considerably when the concentrated latex is added at small amount but it becomes higher values when adding the concentrated latex reaches at some amount. In the future, this indicates that the use of concentrated latex at some suitable amount can develop the concrete having the properties of waterproof and thermal insulation.

AbstractSustainable energy has turned into one of the most promising ways to handle the challenges of energy demand problems of numerous consumers worldwide. Myanmar's energy consumption mainly depends upon traditional energy such as fuel wood, charcoal and biomass. The government had laid the energy policy guidelines and emphasized in renewable energy resources to replace traditional energy types. Although domestic conventional energy sources such as oil and natural gas have been increasing a little bit through discoveries and development, these does not satisfy the demand of the country. In this paper, the energy utilization and the present sustainable energy status are mentioned. Following that, completed projects by each sector are provided. The future plan for energy conservation is finally highlighted.

AbstractWith the lack of a management budget and weak policy for waste management of local communities in developing countries, especially for clusters that have the amount of garbage less than 5 tons per day, open dumping or open burning is the most common municipal solid waste (MSW) management, leading to severe impact on the environment. This study focuses on the sustainable development and eco-friendly waste management concept for these local communities. First, public participation campaigns with the 3R's concept (Reduced, Reuse and Recycle) must be launched to reduce and separate waste from households to be mixed with combustible waste, organic waste, and recycled waste. If the separation at the source is successful, the treated waste of about 2.5 tons is divided into wet and dry fractions. The wet fraction can be easily treated by conventional composting to produce soil conditioners and generate income for communities. The dry fraction must be treated by an incinerator. However, due to the high moisture content and low heating value of the waste, the incinerator needs to run with additional fossil fuel, causing high operating costs. Therefore, a novel hybrid incineration-gasification system has been introduced in this study to use Refuse Derived Fuel (RDF) prepared by dry fraction as feedstock to a downdraft gasifier. The producer gas generated from the gasifier can be used to substitute fossil fuel. This sustainable and eco-friendly model of waste management can be used as a prototype model for other rural areas in low or low-middle income countries.