A relative study on energy and exergy analysis between conventional single slope and novel stepped absorbable plate solar stills.

The innovation of novel absorbing materials using composite materials and nanotechnology is of new trends for many researches. Here, the present study is concerning to enhance the distilled water productivity of a proposed solar still (PSS) using novel absorbing materials. The absorbing material is composed of chitosan (obtained from waste shrimp shells), ethylene diamine tetraacetic acid (EDTA), and Chrysopogon zizaniodes (Vetiver). The combination of these materials is coined as CHEDZ, and it acts as a super absorbent polymer that is coated on the stepped solar still. Evaporation rate increases due to this absorbent, which further increases the yield of the still. In this present study, the PSS is compared with the conventional solar still (CSS) for the use of assessing the yield of freshwater in the same atmospheric circumstance. The experimental setup was performed through the period from December to February 2020 in the Indian climatic condition. The freshwater productivity was improved to 3.05 L/day while the yield of the CSS is 2.47 L/day. The increase in efficiency obtained from a PSS is 39.71% more than the productivity attained from the CSS. The energy efficiency of the PSS is 18.34% and the exergy efficiency is 0.45%.

Impact of Mindfulness-based Stress Reduction (MBSR) on Depression among Elderly Residing in Residential Homes.

Old age is a period when people need physical, emotional, and psychological support. Depression is the most prevalent mental health problem among older adults and it contributes to increase in medical morbidity and mortality, reduces quality of life and elevates health care costs. Therefore early diagnosis and effective management are required to improve the quality of life of older adults suffering from depression. Intervention like Mindfulness based Stress Reduction is a powerful relaxation technique to provide quick way to get rid of depression and negative emotions by increasing mindfulness. The study was undertaken to assess the effectiveness of MBSR on depression among elderly residing in residential homes, Bangalore. In this study, quasi experimental pre-test post-test control group research design was used. There were two groups: experimental and control, each group had 30 samples selected from different residential homes by non-probability convenience sampling technique. Pre-test depression and mindfulness was assessed before the first day of intervention. Experimental group participants were provided intervention on MBSR. Assessment of post-test depression and mindfulness was done at the end of the intervention programme for both group participants. The study revealed significant reduction in depression (p < 0.001) and increase in mindfulness (p < 0.001) among elderly in the experimental group who were subjected to MBSR technique.

Role of the stimulated-emission rate in the photostability of solid-state dye lasers.

The lasing and photostability characteristics of Rhodamine 6G and Pyrromethene 567 dyes dispersed in polymeric host materials have been investigated as a function of the intensities of incident pump and signal beams in a longitudinally pumped dye laser in an oscillator-amplifier configuration. A substantial reduction in the rate of photodegradation was observed under lasing conditions and with increasing signal intensity in a dye amplifier, establishing that the service lives of these materials improve with an increase in the rate of stimulated emission. We observed approximately 62% amplifier efficiency at 2 Hz operation and 10% reduction in amplifier efficiency at 10 Hz operation after exposure of 72,000 pulses by use of a Pyrromethene disk.

High-repetition-rate, narrow-band dye lasers with water as a solvent for dyes.

The performance of a copper vapor laser-pumped narrow-band dye laser in oscillator-amplifier configuration with water-based binary mixture solvents is described. Although oscillator efficiency in water-surfactant (sodium lauryl sulfate) solvent was comparable with that that employed pure ethanolic solvent, amplifier efficiency was found to be lower. Experiments that were carried out with vertically polarized pump beams and either horizontally or vertically polarized signal beams show that, in case of both the pump and signal having orthogonal polarization (horizontal) and same polarization (vertical), the extraction efficiency for both ethanolic and water-micelle media increased substantially from 15.7% to 18.5% and from 10% to 12.5%, respectively. However, the relative difference remained nearly the same, indicating that a slower orientational diffusion of excited dye molecules in a micellar medium is not responsible for a decrease in amplifier efficiency. Amplifier efficiency comparable with that containing ethanolic dye solutions could be obtained with a binary solvent that comprises a mixture of water and about 30% n-propanol. The performances of two efficient dyes, Rhodamine-6G and Kiton Red S, using water-based solvents were studied.