Hydrogeological and Hydrochemical Characterization of Coastal Aquifers with Special Reference to Submarine Groundwater Discharge in Uttara Kannada, Karnataka, India

In coastal areas of our country, in spite of having excess rainfall (more than 3000 mm), groundwater become a rare commodity during summer. Number of researchers have discussed the issues related to water scarcity of coastal areas where there is a huge pressure on environment due to increased population, tourism, agriculture and industrial growth. Fast depletion of groundwater is also reported in coastal districts due to continuous discharge of direct runoff and also through subterranean flow which is termed as Submarine Groundwater Discharges (SGD). Large quantity of contaminants enter the ocean system through runoff. This necessitated a detailed investigation to understand the hydrological processes involved and the source of contaminants. The present investigation is an attempt to make quantitative and qualitative assessment of SGD based on hydrological, hydrogeological and hydrochemical components. Accordingly, water balance components were evaluated based on hydrological and hydrogeological investigations. Hydrochemical parameters were also evaluated to understand the impact of seawater intrusion in pre and postmonsoon of 2019. Study revealed that, there are signatures of considerable quantity of submarine groundwater discharge in parts of Honnavara, Kumta, Ankola and Karwar talukas. The influence of seawater in coastal aquifers is quite rare all along the coast of Uttara kannada district which is attributed to high groundwater recharge (15-20%) occurring in catchment areas

Integration of emerging PCMs and nano-enhanced PCMs with different solar water heating systems for sustainable energy future: A systematic review

Solar water heaters (SWHs) are primarily used to generate hot water to meet daily needs in domestic and industrial applications. Due to its technical and economic practicality, solar water heating has been widely exploited for use of solar energy. However, the inconsistent availability of solar radiation and lack of energy storage facilities restrict its utilization. Thermal energy storage materials (Phase change materials and nano-enhanced phase change materials) are key solutions for effectively harvesting thermal energy from solar radiation. Integrating phase-change materials (PCMs) and nano-enhanced phase-change materials (NE-PCMs) with SWHs overcome the constraint of only being used during the daytime and making them more efficient. The main aim of this systematic review article is to summarize and highlights the key results of recent studies on SWHs integrated with PCMs and NE-PCMs for domestic and industrial water heating applications. This study also highlights the technical issues associated with SWH systems. In addition, the perspectives, recommendations, and future improvements of the SWH systems integrated with PCMs and NE-PCMs are explored to overcome the technical barriers to their practical use. In conclusion, the thermal performance of SWHs with the help of PCMs and NE-PCMs increased significantly, and the cost of the system was reduced, resulting in a shorter payback period compared to conventional SWHs. Also, there is a considerable reduction in CO2 emissions from an environmental perspective. It is intended that this study will provide new insights to the researchers to design and develop highly efficient SWH systems

Optimum Criteria on the Performance of an Irreversible Braysson Heat Engine Based on the new Thermoeconomic Approach

An irreversible cycle model of a Braysson heat engine operating between two heat reservoirs is used to investigate the thermoeconomic performance of the cycle affected by the finite-rate heat transfer between the working fluid and the heat reservoirs, heat leak loss from the heat source to the ambient and the irreversibility within the cycle. The thermoeconomic objective function, defined as the total cost per unit power output, is minimized with respect to the cycle temperatures along with the isobaric temperature ratio for a given set of operating parameters. The objective function is found to be an increasing function of the internal irreversibility parameter, economic parameters and the isobaric temperature ratio. On the other hand, there exist the optimal values of the state point temperatures, power output and thermal efficiency at which the objective function attains its minimum for a typical set of operating parameters. Moreover, the objective function and the corresponding power output are also plotted against the state point temperature and thermal efficiency for a different set of operating parameters. The optimally operating regions of these important parameters in the cycle are also determined. The results obtained here may provide some useful criteria for the optimal design and performance improvements, from the point of view of economics as well as from the point of view of thermodynamics of an irreversible Braysson heat engine cycle and other similar cycles as well

Energy and exergy performance evaluation of a typical solar photovoltaic module

This paper presents the energy and exergy performance evaluation of heterojunction with intrinsic thin layer (HIT) solar photovoltaic (SPV) module for a particular day of different months of the year of a typical climatic zone of north India. The energy, exergy and power conversion efficiencies have been calculated and plotted against time based on hourly insolation. The variation in all the efficiencies has been observed with respect to variation in solar radiation and wind speed and found that all the efficiencies are higher in morning and evening time as compared to noon time which is due to the variation in temperature of module throughout the day. Performance of SPV module has been found to be the best in the month of February i.e. all the three efficiencies have been found to be the highest among all the months analysed and presented in the study for the month of February. The energy efficiency is found to be always higher than that power conversion and exergy efficiencies. However, exergy efficiency in some months like February, May, June, September, October and December has been found to be higher than that of power conversion efficiency, reverse is found in rest of the months

Activation of GPR56, a novel adhesion GPCR, is necessary for nuclear androgen receptor signaling in prostate cells.

The androgen receptor (AR) is activated in patients with castration resistant prostate cancer (CRPC) despite low circulating levels of androgen, suggesting that intracellular signaling pathways and non-androgenic factors may contribute to AR activation. Many G-protein coupled receptors (GPCR) and their ligands are also activated in these cells indicating that they may play a role in development of Prostate Cancer (PCa) and CRPC. Although a cross talk has been suggested between the two pathways, yet, the identity of GPCRs which may play a role in androgen signaling, is not established yet. By using blast analysis of 826 GPCRs, we identified a GPCR, GPCR 205, which exhibited maximum similarity with the ligand binding domain of the AR. We demonstrate that adhesion GPCR 205, also known as GPR56, can be activated by androgens to stimulate the Rho signaling pathway, a pathway that plays an important role in prostate tumor cell metastasis. Testosterone stimulation of GPR56 also activates the cAMP/ Protein kinase A (PKA) pathway, that is necessary for AR signaling. Knocking down the expression of GPR56 using siRNA, disrupts nuclear translocation of AR and transcription of prototypic AR target genes such as PSA. GPR56 expression is higher in all twenty-five prostate tumor patient's samples tested and cells expressing GPR56 exhibit increased proliferation. These findings provide new insights about androgen signaling and identify GPR56 as a possible therapeutic target in advanced prostate cancer patients

Chemical sintering of TiO2 based photoanode for efficient dye sensitized solar cells using Zn nanoparticles

Recombination reactions due to poor inter-particle contact at lower temperatures (< 450 °C) is a bottle neck for cost effective flexible dye sensitized solar cells (DSSCs). In this study, TiO2sintering to Coble initial stage at low temperatures has been achieved with low melting point zinc (Zn) metal nanoparticles. Zn nanoparticles showed improved inter-particle contact by formation of necks due to high surface diffusion at relatively lower temperatures (200 °C). Addition of Zn nanoparticles showed comparable, rather improved efficiency at 200 °C compared to reference TiO2photoanode fabricated at 450 °C due to neck formation and surface plasmonic resonance (SPR) effect. Morphological studies revealed high contact formation between TiO2 and Zn nanoparticles. Electrochemical impedance and Uv–vis spectroscopy showed improvements in charge transfer and light absorption activity respectively. Structural studies showed no any detectable change in phase due to high surface diffusion and capillary forces produced by Zn nanoparticles at the TiO2/Zn interface