Life cycle cost analysis of a double-effect solar still

In this present paper, the study focuses on the development of a double-effect solar still with evacuated tubes for water desalination considered for small-scale applications at remote locations where only saline water or brackish water is available. In this present paper, the potable water cost per litre has been evaluated. The payback periods for different conditions of the distribution of distilled water, namely at the cost it is produced and at the selling price on market rate, have been evaluated. The cost of water per litre was a minimum of Rs. 0.19 with the average distillate output being about 20?l/day, when the interest rate and the lifetime of the solar still are taken as 4% and 50 years, respectively. The lowest payback time of 45 days was obtained when the selling price of water was Rs. 20?per litre.     

Various techniques for improvement in distillate output from active solar still: a review

Solar still is one of the most promising technology to convert available brackish or saline water into drinkable water. It is not widely used due to the lower distillate output from it. Passive and active are the two main types of solar still. Distillate output of a passive solar still is lower compared with that of an active solar still. Hence, for increment in distillate output from the solar still, active solar still is the only viable option. The present review shows the various techniques available in an active solar still for increment in distillate output.     

Structural,optical, and electrical properties of flash-evaporated copper indium diselenide thin films

Copper indium diselenide (CuInSe₂) compound was synthesized by reacting its elemental components, i.e., copper, indium, and selenium, in stoichiometric proportions (i.e., 1:1:2 with 5% excess selenium) in an evacuated quartz ampoule. Structural and compositional characterization of synthesized pulverized material confirms the polycrystalline nature of tetragonal phase and stoichiometry. CuInSe₂ thin films were deposited on soda lime glass substrates kept at different temperatures (300–573 K) using flash evaporation technique. The effect of substrate temperature on structural, morphological, optical, and electrical properties of CuInSe₂ thin films were investigated using X-ray diffraction analysis (XRD), atomic force microscopy (AFM), optical measurements (transmission and reflection), and Hall effect characterization techniques. XRD analysis revealed that CuInSe₂ thin films deposited above 473 K exhibit (112) preferred orientation of grains. Transmission and reflectance measurements analysis suggests that CuInSe₂ thin films deposited at different substrate temperatures have high absorption coefficient (~10⁴ cm⁻¹) and optical energy band gap in the range 0.93–1.02 eV. Results of electrical characterization showed that CuInSe₂ thin films deposited at different substrate temperatures have p-type conductivity and hole mobility value in the range 19–136 cm²/Vs. Variation of energy band gap and resistivity of CuInSe₂ thin films deposited at 523 K with thickness was also studied. The temperature dependence of electrical conductivity measurements showed that CuInSe₂ film deposited at 523 K has an activation energy of ~30 meV.     

Influence of silicon content on the microstructure and hardness of CrN coatings deposited by reactive magnetron sputtering

CrN and CrSiN films were deposited on the stainless steel and silicon substrates by DC magnetron sputtering and their microstructural features were investigated by X-ray diffraction (XRD), scanning electron microscope (FE-SEM/EDS), and atomic force microscopy (AFM). The influence of Si content along with process parameters such as power on the microstructural characteristics of Cr–Si–N and CrN films were investigated and compared between each other. The power and increasing Si contents strongly influence the microstructural and hardness of the deposited films. XRD analysis of the coatings indicates a grain refinement with increase in Si content during deposition of coatings, which is tandem with AFM and SEM results. Also, the surface roughness and particle size are decreasing with addition of Si in the films. The hardness of CrN and CrSiN was measured by microhardness tester and found that introduction of Si content in the CrN system increases its hardness from 1839 Hv to 2570 Hv.     

Influence of sputtering parameters and nitrogen on the microstructure of chromium nitride thin films deposited on steel substrate by direct-current reactive magnetron sputtering

Chromium nitride thin films were deposited on SA-304 stainless steel substrates by using direct-current reactive magnetron sputtering. The influence of process conditions such as nitrogen content in the fed gas, substrate temperature, and different sputtering gases on microstructural characteristics of the films was investigated. The films showed (200) preferred orientation at low nitrogen content (< 30%) in the fed gas. The formation of Cr₂N and CrN phases was observed when 30% and 40% N₂ were used, with a balance of Ar, respectively. Field emission scanning electron microscopy and atomic force microscopy were used to characterize the morphology and surface topography of the thin films, respectively. Microhardness tests showed a maximum hardness of 16.95 GPa for the 30% nitrogen content.     

Theoretical and experimental performance analysis of sandstones and marble pieces as thermal energy storage materials inside solar stills

The present research paper deals with the theoretical and experimental investigation of solar stills with two different thermal energy storage materials, namely, marble pieces and sandstones. To carry out this research, three solar stills of 1?m square area have been made. All solar stills have been provided with a glass cover and a cooling and dripping arrangement for reducing top heat loss and maintaining a constant level of water. It has been found that the use of sandstones as storage materials and the cooling and dripping arrangement have a remarkable effect on the distillate output of a solar still. The set-up has been used to augment the distillate output throughout the day. Theoretical results have also been compared with the experimental results and have been found to be in good agreement.     

Optical sensor for temperature measurement using bimetallic concept

In this paper, we report an optical fiber sensor for measuring temperature based on bimetallic concept. The sensor is designed by following the basic principle of Fabry–Perot interferometer and theoretical detail of the sensor has been outlined here with a numerical study. An important feature of the proposed sensor is that the fabrication will be done on a commercial multimode optical fiber. The Micro-Electro-Mechanical Systems (MEMS) based fabrication process could be performed directly on a multimode optical fiber end face which will eliminate the need for adhesive in packaging. The sensor could be fabricated as sensor arrays for micro level applications. The potential application of the proposed optical sensor includes biomedical applications, nano research, microfluidics, and other MEMS devices.     

Investigation of thermoelectric power in indium sesquitelluride(In2Te3) thin films

Polycrystalline and stoichiometric thin films of indium sesquitelluride (In₂Te₃) belonging to the -phase were prepared on glass substrates by flash evaporation technique at a constant temperature of 473 K. The thermoelectric power of these p-type -In₂Te₃ thin films was determined as a function of temperature of the hot end of the films and also of film thickness. It was found that the thermoelectric power is nearly independent of temperature and a possible reason for this behavior has been given. The dependence of the thermoelectric power on the reciprocal thickness of the films has also been discussed on the basis of the size effect theories.     

A RAPID,SIMPLE AND RELIABLE METHOD OF DIFFERENTIATING BREWING YEAST STRAINS BASED ON DNA RESTRICTION PATTERNS

DNA was isolated from polyploid brewing ale and lager yeast strains using a simple and rapid procedure which was a modification of a previously described method of Seehaus et al.¹⁴ The isolated DNA was cut with a number of restriction enzymes and subjected to agarose gel electrophoresis. Significant differences in banding patterns were observed between a Saccharomyces cerevisiae ale strain DNA and Saccharomyces uvarum (carlsbergensis) lager strain DNA, particularly with the enzyme Hpal. Differences were also observed between the banding patterns of digests from two ale strains, and from two lager strains. Use of this technique with appropriate restriction enzymes should prove useful for the rapid differentiation of brewing yeast strains.     

Enhancement of the yield of solar still with the use of solar pond: A review

A solar pond (SP) is a remarkable growth of renewable energy technology that has stored solar energy for storage purposes and is used in many solar thermal applications. It is also utilized for many purposes, such as heating, cooling, space heating, air conditioning, and many more. The present paper shows the use of an SP to improve the yield of solar still (SS) by providing hot water through the heat energy stored in it. It also reveals the use of shallow and mini SPs with SS to improve yield. Various future research works on SS using SPs have also been included in this paper. From the current review paper, it was concluded that the SP increases the yield of the SS.