Solar energy, its conversion and utilization

The work being carried out at the University of Florida Solar Energy and Energy Conversion Laboratory in converting solar energy, our only income, into other needed and useful forms of energy is described. A treatment such as this demonstrates, in proper perspective, how solar energy can benefit mankind with its many problems of shortages and pollution. Descriptions were given of the conversion processes, equipment, and performance. The testing of materials, solar water heating, space heating, cooking and baking, solar distillation, refrigeration and air-conditioning, work with the solar furnace, conversion to mechanical power, hot air engines, solar-heated sewage digestion, conversion to electricity, and other devices will be discussed

Computation of irradiance in a solar still by using a refined algorithm

A refined solar algorithm from the ESP-r system has been used to calculate the distribution of solar irradiation inside a basin-type solar still. In the approach, surface finish, view factors and multiple reflections are taken into consideration in the computation of the solar radiation that reaches the surface of the saline water in the distillation system. The algorithm was applied to a solar still tested at the University of Strathclyde in Glasgow (55 520 N, 4 150 W). Under the prevailing meteorological conditions, it was found that previous models overestimated the computed solar load on the saline water surface. The present modelling approach is demonstrated to exhibit a higher degree of accuracy than previous methods for irradiance distribution prediction, yielding new insights into approaches to solar still performance improvement. The modelling outcomes are presented and discussed

Potential for water distillation by using solar energy in Malawi

The potential for solar water distillation in Malawi has been modelled. Mean monthly global solar radiation (H) data from 19 sites spread all over the country was used to compute the mean monthly daily distillate productivity (M). Results show that H varies from 15.3 MJ m*-2 to 27.8 MJ m*-2 while M varies from 1.0 kg m*-2 to 2.5 kg m*-2. Distillate productivity is high (up to 2.5 kg m*-2) during the dry season, in phase with the shortage of water supply. It appears that there is enormous potential for harnessing solar radiation to improve the quality of drinking water in the country

Fabrication of Composite Membranes for Solar-thermal Desalination

With rising human populations, the demand for freshwater is an ever-growing problem. One emerging technology to combat this problem is membrane distillation (MD). MD has several advantages for water desalination such as: •100% rejection of solute (salt, heavy metals, etc.) •Mergeable with other affordable energy sources (solar heat, electric resistance, etc.) However, at the moment the specific energy consumption (SEC) of MD is very high due to low water production rates and large energy inputs to heat water. In a solar-assisted design for MD, the high cost of solar collectors (~$200/m2) inhibits low cost of water production in comparison to reverse osmosis (RO).[1] Low water production rates for MD designs can be addressed with high-performance membranes and distillation modules. Solar-integrated devices will improve MD efficiencies and make it a marketable technology for desalination processes. This research poster shows great improvement upon current MD efficiencies

Design Construction and Performance Evaluation of Solar Still for Rural Dwellers

This paper is aimed at designing, constructing and performance evaluation of a solar still. The solar still is design and constructed with locally source materials for rural dwellers. The still absorber plate is constructed with 2 mm galvanised plate painted black with an area of 2 m2 to absorb solar radiation effectively. The side wall and the base is constructed with concrete. Sawdust and felt is used between the retaining wall and base to resist heat transfer from the system to the surrounding vice-versa. The top cover of the still is constructed with transparent glass pane of 4 mm housed in an aluminium frame. The catch basin that collects the condensate is constructed with PVC pipe channel of 50 mm. The performance of the still was evaluated with; Overall yield (sum of daily yield and over-night yield) at a different water depth of (20, 40, 60 mm), (5127 ml/m2/hr, 4558 ml/m2/hr, and 3852 ml/m2/hr). The efficiency of the system at different water depth (20, 40, 60 mm) 51.27 %, 45.58 %, and 38.52 %. The water analysis before and after distillation was certified safe and portable for human consumption

Rancang Bangun Sistem Distilasi Air dalam Proses Pengolahan Air Bersih dengan Menggunakan Fresnel Lens Solar Collector

Distillation system using direct solar energy, often called solar still, has been considered as the environmentally friendly system in utilizing solar energy. In this study, double slope solar still has been fabricated with galvanis basin for the test solution and also the addition of fresnel lens solar collector. The issues to be discussed include how much the average distilled water (distilant) can be produced from the system, so that the result can be compared to the theoretically distilant for obtaining an efficiency of the distillation system that has been fabricated. In distilant composition testing, salinity testing performed in both test solution (NaCl solution) and distilant, so it can be seen the reduction in salinity in the distillation process on the system. The measurement was conducted in May 2014, the average solar irradiation was recorded in the range 309.4 - 574.4 Watt/m2 and a system efficiency is obtained around 6- 8,2%. In salinity testing, the result showed that the salinity of distilant decreased by 96.42% compared to the test solution

Cosmic-ray strangelets in the Earth's atmosphere

If strange quark matter is stable in small lumps, we expect to find such lumps, called ``strangelets'', on Earth due to a steady flux in cosmic rays. Following recent astrophysical models, we predict the strangelet flux at the top of the atmosphere, and trace the strangelets' behavior in atmospheric chemistry and circulation. We show that several strangelet species may have large abundances in the atmosphere; that they should respond favorably to laboratory-scale preconcentration techniques; and that they present promising targets for mass spectroscopy experiments.Comment: 28 pages, 4 figures, revtex

Energy-water-environment nexus underpinning future desalination sustainability

Energy-water-environment nexus is very important to attain COP21 goal, maintaining environment temperature increase below 2 °C, but unfortunately two third share of CO2 emission has already been used and the remaining will be exhausted by 2050. A number of technological developments in power and desalination sectors improved their efficiencies to save energy and carbon emission but still they are operating at 35% and 10% of their thermodynamic limits. Research in desalination processes contributing to fuel World population for their improved living standard and to reduce specific energy consumption and to protect environment. Recently developed highly efficient nature-inspired membranes (aquaporin & graphene) and trend in thermally driven cycle's hybridization could potentially lower then energy requirement for water purification. This paper presents a state of art review on energy, water and environment interconnection and future energy efficient desalination possibilities to save energy and protect environment

Acrylic purification and coatings

Radon (Rn) and its decay daughters are a well-known source of background in direct WIMP detection experiments, as either a Rn decay daughter or an alpha particle emitted from a thin inner surface layer of a detector could produce a WIMP-like signal. Different surface treatment and cleaning techniques have been employed in the past to remove this type of contamination. A new method of dealing with the problem has been proposed and used for a prototype acrylic DEAP-1 detector. Inner surfaces of the detector were coated with a layer of ultra pure acrylic, meant to shield the active volume from alphas and recoiling nuclei. An acrylic purification technique and two coating techniques are described: a solvent-borne (tested on DEAP-1) and solvent-less (being developed for the full scale DEAP-3600 detector).Comment: Proceedings of Topical Workshop on Low Radioactivity Techniques (LRT 2010), SNOLAB, Sudbury, Canada, Aug 28-29, 201