Publications by authors named "Ravishankar Sathyamurthy"

42 Publications

Analysis of a solar still with photovoltaic modules and electrical heater - Energy and exergy approach.

Environ Sci Pollut Res Int 2022 Mar 29. Epub 2022 Mar 29.

Department of Mechanical Engineering, KPR Institute of Engineering and Technology, Arasur, Coimbatore, Tamil Nadu, 641407, India.

The availability of drinkable water, along with food and air, is a fundamental human necessity. Because of the presence of higher amounts of salt and pollution, direct use of water from sources such as lakes, sea, rivers, and subsurface water reservoirs is not normally suggested. Solar is still a basic technology that can use solar energy to transform accessible waste or brackish water into drinkable water. Exergy analysis is a strong inferential technique for evaluating the performance of thermal systems. Exergy is becoming more popular as a predictive tool for analysis, and there is a rising interest in using it. In this paper, performance analysis on the aspect of energy and exergy from the proposed solar still (PSS) (conventional solar still with the photovoltaic modules-AC heater) was analyzed on three different water depths (W) conditions (1, 2, and 3 cm). Using a solar still with an electric heater, the daily potable water production was found as 8.54, 6.37, and 4.43 kg, for the variations in water depth (W) of 1, 2, and 3 cm respectively. The energy and exergy efficiency of the PSS at the W of 1, 2, and 3 cm were 75.67, 51.45, and 37.21% and 5.08, 2.29, and 1.03%, respectively. At 1 cm W, PSS produced the maximum freshwater yield as compared to the other two water depths. When the W is increased from 1 to 2 cm and from 1 to 3 cm, the yield is decreased up to 27.3 and 52.7%, respectively. Similarly, the energy and exergy efficiency is decreased up to 36.8 and 53.2% and 50.4 and 80.6%, respectively. The water cost of the modified solar still is calculated as 0.028 $/kg for the least water thickness.
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http://dx.doi.org/10.1007/s11356-022-19674-1DOI Listing
March 2022

Comparative studies on performance of solar towers with variable scale ratios.

Environ Sci Pollut Res Int 2022 Feb 11. Epub 2022 Feb 11.

Department of Mechanical Engineering, KPR Institute of Engineering, Tamil Nadu, Arasur, Coimbatore, 641407, India.

Improvements in the geometry of solar towers are explained in this study. Both computational and experimental studies are carried out. Three different solar towers of 1:60, 1:70, and 1:122 scale ratios are taken for the study. All the studies are carried out in an open atmosphere, where a hot wire anemometer is used to measure the peak velocity at the collector-tower junction. The collector geometry is kept flat, inclined, and semi-divergent. The tower geometry is modified from the straight tower into semi-divergent and fully divergent towers. The fully divergent tower with a semi-convergent collector achieves the highest power output among the other two models. The area convergence is the prime factor for an increase in peak velocity. The divergent tower with a semi-convergent collector achieves 54% more power output than a cylindrical tower with a flat collector.
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http://dx.doi.org/10.1007/s11356-022-19079-0DOI Listing
February 2022

Improving the potable water generation through tubular solar still using eggshell powder (bio-based energy source) as a natural energy storage material - an experimental approach.

Environ Sci Pollut Res Int 2022 Jan 27. Epub 2022 Jan 27.

Department of Mechanical Engineering, KPR Institute of Engineering and Technology, Arasur, Coimbatore, 641407, Tamil Nadu, India.

The demand for fresh water is rapidly growing as a consequence of the increasing population and urbanization. Tubular solar still offers larger evaporative and condensing surface area as compared to single slope solar still. The aim of this study is to improve the performance of tubular solar still by employing eggshell powder (collected from Babcobb Broilers chicken) as the sensible energy storage material in form of bed, placed inside the basin of still to improve the water production. Results showed that the influence of eggshell powder as energy storage material in the basin improved the average water temperature by 3%, 6.2%, and 3.2% for the water thickness of 10, 15, and 20 mm, respectively. The usage of eggshells as a sensible energy storage in the basin augmented the peak hourly water yield by 67.64% with minimum water thickness. The total observed distillate output from the solar still is 1.45 kg without eggshell powder and 2.67 kg for with eggshell powder in the absorber at the lowest water thickness of 10 mm. TSS with eggshell powder as energy storage has a daily energy efficiency of 48.17%, 42.38%, and 36.38%, respectively, for water thicknesses of 10, 15, and 20 mm in the basin. Water thickness of 10, 15, and 20 mm has performance improvement ratios of 1.83, 1.81, and 1.78, respectively. Using cost analysis, it was found that the cost of drinkable water generated using eggshell as an energy storage material is 0.011$/kg, but the cost of water by traditional still without any storage material was 0.021$/kg.
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http://dx.doi.org/10.1007/s11356-022-18906-8DOI Listing
January 2022

Performance improvements of hemispherical solar still using internal aluminum foil sheet as reflector: energy and exergy analysis.

Environ Sci Pollut Res Int 2022 May 22;29(24):36887-36896. Epub 2022 Jan 22.

Department of Mechanical Engineering, KPR Institute of Engineering and Technology, Arasur, Coimbatore, Tamil Nadu, 641407, India.

Various scientists are looking for effective and easy solutions for the augmentation of yield from the hemispherical solar still (HSS). In this study, aluminum foil sheet was used to reflect the intensity, hence augmenting the evaporation rate and daily yield. Experimentations were conducted on two SS: the first SS is HSS; the second SS is HSS with reflective aluminum foil sheet walls (HSS-RAFW). The highest distilled water production from the HSS and HSS-RAFW is 3.36 and 4.1 kg/m, respectively. Compared to the HSS, the yield of distilled water was augmented by 22.21% when using the HSS-RAFW. The daily energy and exergy efficiencies (EnE and ExE) of the HSS are 26.27 and 1.04%, respectively, and the daily EnE and ExE of the HSS-RAFW are 32.75 and 1.71%, respectively.
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http://dx.doi.org/10.1007/s11356-021-17973-7DOI Listing
May 2022

Solar distillation meets the real world: a review of solar stills purifying real wastewater and seawater.

Environ Sci Pollut Res Int 2022 Apr 20;29(16):22860-22884. Epub 2022 Jan 20.

Department of Mechanical Engineering, Pohang University of Science and Technology, Pohang, 37673, South Korea.

Solar energy-driven evaporation-based freshwater production is one of the sustainable ways to purify contaminated/salty water. Recent advances in solar absorbers' assemblies, design modifications, and integrations with heating sources improved the rate of freshwater productivity. However, the type of feed water affects the evaporation rate in a solar desalination system (SDS). Many studies used tap water with added contaminants to test the performance of a SDS and studied the water quality improvement. As a typical result, pH, total dissolved solids (TDS), and electrical conductivity (µS/cm) are reduced after solar evaporation. The performance of SDSs for real wastewaters are also important to understand, e.g., the reduction of high organic pollutants after solar evaporation. In this aspect, the main objective of the present work is to review solar distillation of real wastewaters and seawater by using SDSs. Further, the mechanism of a solar distiller with heat transfer principles, parameters affecting evaporation process, real wastewaters and seawaters purified in a solar distillation system, improvement of various parameters before and after solar evaporation, pathways of handling wastewaters, challenges, and future perspectives are discussed. Conclusively, SDSs are found to remove pollutants effectively after solar evaporation. The evaporation rate is relatively slower due to high concentration of pollutants that reduce vapor pressure. The COD removal of various real wastewaters, including sludge, kitchen, textile, palm oil, petroleum, water plant, and municipal wastewaters, was 98.13%, 97.85%, 96.84%, 96.71%, 87.99%, 86.99%, and 85.67%, respectively. The reduction rate of salt concentration in real seawater after evaporation in the solar distiller was 99.99%.
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http://dx.doi.org/10.1007/s11356-022-18720-2DOI Listing
April 2022

Sinusoidal pulse width modulation for a photovoltaic-based single-stage inverter.

Environ Sci Pollut Res Int 2022 Apr 7;29(20):29830-29840. Epub 2022 Jan 7.

Department of Mechanical Engineering, KPR Institute of Engineering and Technology, Coimbatore, 641407, Tamil Nadu, India.

The work proposed in this paper focuses on providing an effective solution to the shortage of power in rural areas with an effective technique implemented in an economically feasible way. The traditional inverters used for either residential or commercial purposes consume electrical energy from the grid to fulfill the charging and discharging of the battery, which may lead to overloading. The shortcomings of the traditional inverters such as the nonrenewable nature of power sources increased cost of manufacturing, and multistage conversion complexity is considered by the researchers for improvement. As a result, an attempt has been made to provide a cost-effective renewable energy system with a single-stage topology for ac power applications. Single-stage power conversion with an allowed shoot through the state is used here to avoid additional components and reduce the switching losses. Unlike the traditional inverters, the quasi-impedance source inverter (QZSI) that is brought forward can be utilized as a standalone system or a capable backup at the time of power outages. Sinusoidal pulse width modulation (SPWM) is applied to attain reduced harmonics which are measured by observing the harmonic pattern in the total harmonic distortion (THD) curve. The lab results obtained through MATLAB simulation confirm the noteworthy diminution of the THD level in the proposed system compared to the reported one. Usage of photovoltaic (PV) panels to tap energy with reduced stochastic fluctuations due to the high filtering capacity of the proposed circuit, eliminating the need for additional filters, is the uniqueness of this technique.
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http://dx.doi.org/10.1007/s11356-021-18422-1DOI Listing
April 2022

Optimization of thermal efficiency on solar parabolic collectors using phase change materials - experimental and numerical study.

Environ Sci Pollut Res Int 2022 Feb 7;29(10):14719-14732. Epub 2021 Oct 7.

Department of Mechanical Engineering, KPR Institute of Engineering and Technology, Arasur, Coimbatore, Tamil Nadu, 641407, India.

Solar energy is a one-of-a-kind renewable energy source that has many uses, and in the thermal applications, it is receiving more attention and is becoming more feasible. The present work presents numerical and experimental studies to investigate the performance of a parabolic trough solar concentrator (PTC) integrated with a thermal energy storage system. A new receiver design is built that stores thermal energy using phase change material (PCM). A concentric absorber tube with two different kinds of PCM - MgCl·6HO and erythritol (filling the annular-space of absorber tube) - were used to construct a PTC, and its thermal performance and thermal efficiency were investigated under two different HTF flow rates of 0.005 kg/s and 0.033 kg/s. Solar energy is transformed into heat, which is then used to store in the PCM before being discharged to cold water, which is the final heat transfer fluid in the receiver's inner pipe. The simultaneous studies of the PTC with and without PCM are investigated. A commercial Mat Lab's operating model through an imperialist competitive algorithm of the entire PTC system is presented, and the numerical results were compared to the experimental results, which were carried out with and without PCM in PTC. With the PCM in PTC (0.005 kg/s and 0.033kg/s), the HTF exhibited gain in peak temperatures of 11°C (erythritol) and 9°C (MgCl2·6H2O) at 0.05 kg/s, whereas the peak temperatures further increase to 14°C (erythritol) and 12°C (MgCl2·6H2O) respectively at 0.033 kg/s, as compared to HTF without PCM. Average thermal efficiency of PTC with HTF flow rate of 0.033 kg/s was highest with usage of erythritol (40.6%), among all the cases. The experimental and predicted thermal efficiency performance indices for different flow rates and PCM are found to be with a deviation of around ± 1.9%, demonstrating the accuracy of the developed numerical model.
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http://dx.doi.org/10.1007/s11356-021-16705-1DOI Listing
February 2022

Experimental investigation of an active inclined solar panel absorber solar still-energy and exergy analysis.

Environ Sci Pollut Res Int 2022 Feb 2;29(10):14005-14018. Epub 2021 Oct 2.

Mechanical Power Engineering Department, Faculty of Engineering, Tanta University, Tanta, Egypt.

The objective of the current study is to investigate the performance of the inclined solar panel basin still (ISPBS) incorporated with a spiral tube collector (STC) for various mass flow rates of water (m). The maximum potable water yield of 8.1, 6.9, and 6.1 kg is obtained for different mass flow rates of 1.8, 3.2, and 4.7 kg/h in each instance. Also, for m of 1.8, 3.2, and 4.7 kg per hour, the daily average energy and exergy efficiency of the ISPBS is recorded to be 47.9, 39.3, and 31.02 % and 9.8, 7.9, and 5.6 %, in each instance. The average electrical, thermal, and exergy efficiency of the PV panel is noted to be 6.5, 7.1, and 7.5 %; 15.67, 17.1, and 18.04 %; and 20.03, 22.21, and 23.36 % for m of 1.8, 3.2, and 4.7 kg/h in each instance. The rise in m causes a drop in the fresh water production yield; thermal, exergy, and overall thermal effectiveness; and an enhancement in the power production of the panel, electrical, thermal, exergy, and overall exergy efficiency of the system. Also, the cost of yield production is noted to be low-cost in AISS at minimum m of 1.8 kg per hour (0.019 $/l) when compared to the other two m of 3.2 and 4.7 kg per hour (0.022 and 0.025 $/l).
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http://dx.doi.org/10.1007/s11356-021-16444-3DOI Listing
February 2022

Exploring the photo-thermal conversion behavior and extinction coefficient of activated carbon nanofluids for direct absorption solar collector applications.

Environ Sci Pollut Res Int 2022 Feb 28;29(9):13188-13200. Epub 2021 Sep 28.

School of Mechanical Engineering, Yeungnam University, 280 Daehak-Ro, Gyeongsan, Gyeongbuk, 712-749, Republic of Korea.

This work aims to explore the optical and thermal conversion characteristics of activated carbon-solar glycol nanofluids with various volume fractions namely 0.2, 0.4, and 0.6%, respectively. Kigelia africana leaves were synthesized into porous activated carbon nanomaterials by using the high-temperature sintering process and the pyrolysis process in a muffle furnace. The experimental investigation was carried out with different nanofluid concentrations by using the solar simulator. Nanofluids were heated with the assistance of a solar simulator test system and the convection/conduction heat loss was decreased by using the glass as an insulating material around the test section. Prepared nanofluid with 0.6 vol% activated carbon augmented the thermal conductivity by 14.36% at 60°C. The maximum temperature difference of 10°C was attained at 0.6% volume concentrations of nanofluid as compared with base fluid (solar glycol). In addition, maximum receiver efficiency of 94.51% was attained at 0.6% volume fractions of activated carbon-based nanofluid compared with solar glycol thru a light radiation time of 600 s. Moreover, activated carbon-based nanofluid exhibited significantly higher absorption efficiency as the majority of the radiation was absorbed by the nanofluid. It is concluded that activated carbon-based nanofluids could be a suitable low-cost highly stable material for developing working fluid for direct absorbance solar collector-based applications.
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http://dx.doi.org/10.1007/s11356-021-16637-wDOI Listing
February 2022

Experimental investigation of removal of flue gas emissions exhaust from municipal solid waste incinerator using photovoltaic-based electrostatic precipitator.

Environ Sci Pollut Res Int 2022 Feb 16;29(8):11209-11218. Epub 2021 Sep 16.

Department of Mechanical Engineering, KPR Institute of Engineering and Technology, Arasur, Coimabtore, Tamil Nadu, 641407, India.

For the past decades, the flue gas emitted from municipal solid waste incinerator, power plant, and various industries is a permanent problem for the environment and has been affecting human life. Many flue gas filtration devices have been emerging out over the years. Although the electrostatic precipitator was an appropriate device due to high filtration efficiency and little pressure drop and energy efficiency, the cost and design of the electrostatic precipitator is a major restriction for manufacturers and end-users. With recent advances in technology, designing a cost-effective and less complex electrostatic precipitator has become mandatory. This article aims to design and develop a solar-powered cost-effective needle-plate type electrostatic precipitator which includes a static power converters and high-voltage transformer-rectifier (T-R) set with an input voltage as 230V AC, output voltage as 80-kV direct current (DC), and output current of 40mA for mitigation of flue gas emissions exhaust from municipal solid waste incinerator. The analysis of flue gas at ESP inlet and outlet has been performed using Ecotech stack sampler and flue gas analyzer. The obtained experimental results are validated with emission standards provided in the Solid Waste Management rules book, India, 2016.
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http://dx.doi.org/10.1007/s11356-021-16378-wDOI Listing
February 2022

Exploring the thermo-physical characteristic of novel multi-wall carbon nanotube-Therminol-55-based nanofluids for solar-thermal applications.

Environ Sci Pollut Res Int 2022 Feb 15;29(7):10717-10728. Epub 2021 Sep 15.

School of Mechanical Engineering, Yeungnam University, Gyeongsan, Gyeongbuk, 712-749, Republic of Korea.

This work aims to develop a novel nanofluid using Therminol-55 (T-55) as heat transfer fluid and multi-wall carbon nanotubes (MWCNTs) as dispersants with various volume concentrations of 0.05, 0.1, 0.3, and 0.5% and assess its thermo-physical properties for solar-thermal applications. The pH values of nanofluid MWCNT/T-55 with various particle loading were too far-flung from the pH (I) value, which confirmed the good dispersion stability of nanofluid. The measured density shows tremendous deviation from predicted density with increasing MWCNT loading owing to the non-considering of microstructural parameters in Pak & Cho correlation predication. The highest augmentation in nanofluid thermal conductivity was 16.83% for 0.5 vol. % MWCNT at 60 °C. The maximum improvement in dynamic viscosity of nanofluid with 0.5 vol. % of MWCNT is found to be 44%, and this rise is reduced at higher temperatures. The thermal effectiveness of the nanofluids demonstrates that nanofluid with all volume fractions of MWCNTs was favorable at higher temperatures in the laminar region. Mouromtseff number ratio decreases with a rise in temperature and MWCNT volume concentration. It is concluded that the excellent thermo-physical properties and prolonged thermal stability of the MWCNT will be highly beneficial in improving the overall performance of various kinds of heat transfer fluids (HTFs) for process heating and solar-thermal applications.
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http://dx.doi.org/10.1007/s11356-021-16393-xDOI Listing
February 2022

Exergy and energy analysis of a tubular solar still with and without fins: a comparative theoretical and experimental approach.

Environ Sci Pollut Res Int 2022 Jan 28;29(5):6612-6621. Epub 2021 Aug 28.

Department of Mechanical Engineering, KPR Institute of Engineering and Technology, Arasur, Coimbatore, Tamil Nadu, India.

One of the major challenges faced by human society is the freshwater crisis and shortage of conventional energy. Solar still is considered as one of the promising sources for the production of freshwater from saline water by desalination method. This paper represents the theoretical and experimental study of tubular solar still with and without fins. In this experimental study, the readings were recorded from 8:00 AM to 6:00 PM. The results of this experiment show that the efficiency of tubular solar still (TSS) with fins and without fins is found as 23.39 and 13.76% respectively. The rate of irreversibility from the basin of TSS with flat is higher than TSS with finned absorber and also the rate of irreversibility from water is significantly reduced by TSS with the finned absorber. The exergy analysis showed the maximum exergy efficiency of about 11.8% from the TSS with fins and about 10.6% from the TSS with a flat absorber.
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http://dx.doi.org/10.1007/s11356-021-16065-wDOI Listing
January 2022

Energy and exergy analysis of conventional acrylic solar still with and without copper fins.

Environ Sci Pollut Res Int 2022 Jan 26;29(4):6194-6204. Epub 2021 Aug 26.

Department of Mechanical Engineering, KPR Institute of Engineering and Technology, Arasur, Coimbatore, Tamil Nadu, 641407, India.

A detailed exergy analysis of a conventional and copper finned acrylic solar still has been presented in this manuscript. The evaporative, convective, and radiative heat transfer coefficient of water-glass has been calculated. Also energy efficiency, exergy destruction of basin, water, and glass has been determined. Conventional acrylic solar still with fins produced maximum hourly output of 1.24 kg and it produced daily output of 5.08 kg. The conventional acrylic solar still without fins produced maximum hourly output of 0.94 kg and it produced daily output of 3.75 kg. The maximum exergy destruction of the basin, water, and glass for the conventional acrylic solar still with fins are 655.206, 83.35, and 90.48 W/m, respectively, and conventional acrylic solar still without fins are 616.28, 122.34, and 48.64 W/m, respectively. The energy and exergy effectiveness of the conventional acrylic solar still with fins are 32 and 2.81%, respectively, and without fins are 24.93 and 1.69%, respectively. The study reveals that exergy destruction of water in the case of still with fins is minimum as related to the exergy destruction of water in the case of still without fins.
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http://dx.doi.org/10.1007/s11356-021-16124-2DOI Listing
January 2022

Modeling and simulation of single- and double-diode PV solar cell model for renewable energy power solution.

Environ Sci Pollut Res Int 2022 Jan 18;29(3):4414-4430. Epub 2021 Aug 18.

Department of Mechanical Engineering, KPR Institute of Engineering and Technology, Aras, Coimbatore, Tamil Nadu, ur-641407, India.

Nowadays, most of the country switched to generate their power by renewable energy sources as well as the power industries also mainly focused on the renewable resources for power generation. The renewable resources are solar, wind, biomass, and hydroelectric; out of these, the solar market is developing due to shortage of non-renewable resources. The solar energy is freely obtainable during the year; also, it provides a clean and noiseless environment. Most of the large- and small-scale industries and household consumers moved to generate the power through a PV solar cell. Most of the research work includes the modelling of the PV solar cell based on their requirement in a one-diode model. In this article, a detailed study is provided about the circuit-based single-diode solar cell (SCSC) model and double-diode solar cell (DDSC) with different conditions done in MATLAB/Simulink. Both the SDSC and DDSC models are tested with different values of temperature, irradiation, and shunt resistance. This work helps the researchers study V-I and P-V characteristics of the PV solar cell clearly with different conditions. The outputs of SDSC and DDSC models are compared with simulation outputs. Effect of partial shading is also discussed to get a better idea.
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http://dx.doi.org/10.1007/s11356-021-15870-7DOI Listing
January 2022

Experimental studies on natural convection open and closed solar drying using external reflector.

Environ Sci Pollut Res Int 2022 Jan 5;29(1):1391-1400. Epub 2021 Aug 5.

Faculty of Engineering, Kuwait College of Science and Technology, Doha District, Kuwait.

For low temperature agricultural crop and meat drying, dryers utilizing the renewable energy source (solar energy) appear to be an efficient technique as it is ecofriendly, energy efficient, and available in free of cost. This work presents the experimental investigation on a solar food dryer equipped with external reflectors to enhance the rate of drying efficiency by removing the moisture content available in the anchovy fish. A comparison of conventional open solar drying is carried out to assess the parameters such as drying efficiency, moisture removal rate, and heat energy required for drying the anchovy fish using the modified solar dryer using the natural convection technique. From the experimental results it is observed that the relative humidity greatly influence the rate of drying. The average relative humidity during the experiments using open solar drying is found as 50-65% whereas, the using solar dryer the average relative humidity inside the chamber is found as 20-35%. The relative humidity of the fish using open solar drying is higher as compared to solar dryer drying as the drying products are kept in open atmosphere. The physical examination results on the dried products proved that using a modified solar dryers, the dried product is free from insects, and dust. Also, it is found that the loss of color from the product is a minimum while compared to conventional open solar drying. The results showed that the thermal efficiency of top tray (dryer 1) and bottom tray (dryer 2) is comparatively higher as compared to that of conventional open solar drying and found as 16.73 and 19.34 %, respectively. Results also showed that nearly 20.05% of the energy could be saved using the modified solar dryer as compared to the open solar drying technique.
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http://dx.doi.org/10.1007/s11356-021-15768-4DOI Listing
January 2022

A case study of SARS-CoV-2 transmission behavior in a severely air-polluted city (Delhi, India) and the potential usage of graphene based materials for filtering air-pollutants and controlling/monitoring the COVID-19 pandemic.

Environ Sci Process Impacts 2021 Jul;23(7):923-946

Department of Materials Science and Engineering, Chonnam National University, Gwangju 61186, Republic of Korea.

Globally, humanity is facing its most significant challenge in 100 years due to the novel coronavirus, SARS-CoV-2, which is responsible for COVID-19. Under the enormous pressure created by the pandemic, scientists are studying virus transmission mechanisms in order to develop effective mitigation strategies. However, no established methods have been developed to control the spread of this deadly virus. In addition, the ease in lockdown has escalated air pollution which may affect SARS-CoV-2 transmission through attachment to particulates. The present review summarizes the role of graphene nanomaterials, which show antimicrobial behavior and have antiviral efficacy, in reducing the spread of COVID-19. Graphene and its derivatives have excellent antimicrobial efficacy, providing both physical and chemical mechanisms of damage. Coupled with their lightness, optimal properties, and ease of functionalization, they are optimal nanomaterials for coating onto fabrics such as personal protection equipment, face masks and gloves to control the transmission of SARS-CoV-2 effectively. Biosensors using graphene can effectively detect the virus with high accuracy and sensitivity, providing rapid quantification. It is envisioned that the present work will boost the development of graphene-based highly sensitive, accurate and cost-effective diagnostic tools for efficiently monitoring and controlling the spread of COVID-19 and other air-borne viruses.
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http://dx.doi.org/10.1039/d1em00034aDOI Listing
July 2021

Experimental Investigation of the Emission and Performance Characteristics of a DI Diesel Engine Fueled with the Seed Oil Methyl Ester and Diesel Blends.

ACS Omega 2021 Jun 21;6(22):14068-14077. Epub 2021 May 21.

Department of Mechanical Engineering, SRM Institute of Science and Technology, Kattankulathur 603203, Tamil Nadu, India.

The rapid growth in industrialization steadily increased the energy demand. The world's population ultimately depends on petroleum as a major share of fuel for transportation and industrialization. Even though it is widely used in various sectors, its emission into the atmosphere creates serious problems in the form of acid rain, smog, etc. This present experimental investigation highlights the utilization of seed oil methyl ester (VNSOME) synthesized from seed oil (VNSO) fueled in a diesel engine to assess the emission and performance characteristics. VNSOME is produced using the alkaline catalyst (NaOH) transesterification technique. Four different fuel blends of biodiesel, namely, VNSOME5, VNSOME10, VNSOME15, and VNSOME20, were prepared and fueled in an unmodified engine. The engine brake thermal efficiency is lower, the brake-specific fuel consumption (BSFC) using VNSOME20 is higher, and the temperature of exhaust gas emitted after combustion is increased. The thermal efficiency is reduced by 7.34% with increased BSFC and exhaust gas temperature (EGT) of 9.3 and 14.28%, respectively, as compared to diesel fuel. Similarly, using an optimized biodiesel blend (VNSOME20), the emission emitted such as HC and CO is reduced by 19.14 and 22.2%, respectively. However, the engine fueled with the VNSOME20 biodiesel blend increased the level of CO and NO emitted into the atmosphere when compared to diesel fuel.
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http://dx.doi.org/10.1021/acsomega.1c00437DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8190802PMC
June 2021

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

Environ Sci Pollut Res Int 2021 Nov 5;28(41):57602-57618. Epub 2021 Jun 5.

Ingenium Research Group, Universidad Castilla-La Mancha, Ciudad Real, Spain.

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%.
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http://dx.doi.org/10.1007/s11356-021-14640-9DOI Listing
November 2021

Augmenting the productivity of stepped distiller by corrugated and curved liners, CuO/paraffin wax, wick, and vapor suctioning.

Environ Sci Pollut Res Int 2021 Oct 3;28(40):56955-56965. Epub 2021 Jun 3.

Mechanical Engineering Department, College of Engineering, Taif University, P.O. Box 11099, Taif, 21944, Saudi Arabia.

This paper aimed to improve the thermal performance of the stepped solar still. So, the effects of using different types of basin liners (corrugated and curved basin liners), jute cloth wick, CuO/paraffin wax, and vapor suction on the stepped solar still performance were investigated. The CuO/paraffin wax was placed into a groove parallel to the basin steps' liner. Also, the stepped distiller was integrated with an external condensation unit. The experimental results revealed that using the corrugated and curved liners increased the productivity of the modified stepped solar still (MSSS) by 42% and 33%, respectively. In addition, using the corrugated liner with wick, corrugated liner with wick and CuO/paraffin wax, corrugated liner with wick, CuO/paraffin wax, and vapor suction improved the freshwater productivity of the distiller by 95%, 127%, and 170%, respectively. At the last studied case (MSSS with corrugated liner, wick, CuO/paraffin wax, and vapor suction), the daily freshwater productivities of the MSSS and conventional still (CSS) were 7000 and 2600 mL/m·day, respectively. Also, the thermal efficiency of MSSS was calculated as 59% which was obtained at the last studied case. And the efficiency of the CSS was 35%. Besides, the distilled water cost of CSS and MSSS with corrugated liner with wick, CuO/paraffin wax, and vapor suction was 0.023 and 0.014 $/L, respectively.
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http://dx.doi.org/10.1007/s11356-021-14669-wDOI Listing
October 2021

Recent advancements, technologies, and developments in inclined solar still-a comprehensive review.

Environ Sci Pollut Res Int 2021 Jul 18;28(27):35346-35375. Epub 2021 May 18.

Department of Automobile Engineering, SRM Institute of Science and Technology, Kattankulathur, Tamil Nadu, India.

People around the world are facing water scarcity, and the demand for freshwater is continuously increasing. The purification of water is the only way to satisfy the need for water. Purification can be done in many ways by purifying seawater or by storing rainwater and letting it to the ground. Different types of solar still are there, which are used to increase the output of water produced. Among others, inclined solar still (ISS) is an outstanding solution as it has a wide exterior area of water, having less depth of water to complement the regular potable water production, even the effectiveness of the inclined solar still. A lot of research had been done by increasing the surface area of water. The day to day collection of water from the ISS was found to be 1-8 kg m. In this review, an analysis was made on the current status of different ISS designs to make advance modifications and research to improve the productivity of the ISS to satisfy the increasing demand for potable water. From this investigation, it is identified that active ISS and hybrid ISS are the most effective as compared to other ISS techniques.
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http://dx.doi.org/10.1007/s11356-021-13714-yDOI Listing
July 2021

Correction to: Energy and exergy efficiency analysis of solar still incorporated with copper plate and phosphate pellets as energy storage material.

Environ Sci Pollut Res Int 2021 Sep;28(35):48637

Department of Mechanical Engineering, KPR Institute of Engineering and Technology, Arasur, Coimbatore, Tamil Nadu, India.

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http://dx.doi.org/10.1007/s11356-021-14359-7DOI Listing
September 2021

Energy and exergy efficiency analysis of solar still incorporated with copper plate and phosphate pellets as energy storage material.

Environ Sci Pollut Res Int 2021 Sep 29;28(35):48628-48636. Epub 2021 Apr 29.

Department of Mechanical Engineering, KPR Institute of Engineering and Technology, Arasur, Coimbatore, Tamil Nadu, India.

In this work, a new attempt was made to study the behavior of the conventional solar still (CSS) by adding a black-painted copper plate and phosphate pellets. Therefore, the performance of the three solar stills has been studied and compared. The first is the CSS, and the second is the modified solar still (MSS). The MSS performance was tested using black-coated copper plate (measuring 49 × 49 cm and 0.2 cm thick) with and without phosphate pellets and compared to the CSS in the similar climatic conditions. The results showed that the combination of black coated copper plate and the inclusion of phosphate pellets improved the evaporation rate and daily productivity. During the experiments, yields using black coated copper plate without and with phosphate pellets were 14.96% and 29.53% greater than the CSS. The effectiveness of the CSS, MSS with copper metal plate (MSS-CP), and MSS with copper metal plate with phosphate pellets (MSS-CP and PP) are around 30.23, 35.3, and 41.44%, respectively.
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http://dx.doi.org/10.1007/s11356-021-14080-5DOI Listing
September 2021

Secondary transmission of SARS-CoV-2 through wastewater: Concerns and tactics for treatment to effectively control the pandemic.

J Environ Manage 2021 Jul 19;290:112668. Epub 2021 Apr 19.

School of Mechanical Engineering, Yeungnam University, 280 Daehak-Ro, Gyeongsan, Gyeongbuk, 712-749, Republic of Korea.

The SARS-CoV-2 virus has spread globally and has severely impacted public health and the economy. Hand hygiene, social distancing, and the usage of personal protective equipment are considered the most vital tools in controlling the primary transmission of the virus. Converging evidence indicated the presence of SARS-CoV-2 in wastewater and its persistence over several days, which may create secondary transmission of the virus via waterborne and wastewater pathways. Although, researchers have started focusing on this mode of virus transmission, limited knowledge and societal unawareness of the transmission through wastewater may lead to significant increases in the number of positive cases. To emphasize the severe issue of virus transmission through wastewater and create societal awareness, we present a state of the art critical review on transmission of SARS-CoV-2 in wastewater and the potential remedial strategies to effectively control the viral spread and safeguard society. For low-income countries with high population densities, it is suggested to identify the virus in large scale municipal wastewater plants before following up with one-to-one testing for effective control of the secondary transmission. Ultrafiltration is an effective method for wastewater treatment and usually more than 4 logs of virus removal are achieved while safeguarding good protein permeability. Decentralized wastewater treatment facilities using solar-assisted disinfestation methods are most economical and can be effectively used in hospitals, isolation wards, and medical centers for reducing the risk of transmission from high local concentration sites, especially in tropical countries with abundant solar energy. Disinfection with chlorine, sodium hypochlorite, benzalkonium chloride, and peracetic acid have shown potential in terms of virucidal properties. Biological wastewater treatment using micro-algae will be highly effective in removal of virus and can be incorporated into membrane bio-reaction to achieve excellent virus removal rate. Though promising results have been shown by initial research for inactivation of SARS-CoV-2 in wastewater using physical, chemical and biological based treatment methods, there is a pressing need for extensive investigation of COVID-19 specific disinfectants with appropriate concentrations, their environmental implications, and regular monitoring of transmission. Effective wastewater treatment methods with high virus removal capacity and low treatment costs should be selected to control the virus spread and safeguard society from this deadly virus.
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http://dx.doi.org/10.1016/j.jenvman.2021.112668DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8055200PMC
July 2021

Correction to: A comparative energy and exergy efficiency study of hemispherical and single-slope solar stills.

Environ Sci Pollut Res Int 2021 Jul;28(27):35660

Department of Electronics and Communication Engineering, Kongu Engineering College (Autonomous), Perundurai, Erode, Tamil Nadu, 638060, India.

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http://dx.doi.org/10.1007/s11356-021-13670-7DOI Listing
July 2021

An experimental investigation of a water desalination unit using different microparticle-coated absorber plate: yield, thermal, economic, and environmental assessments.

Environ Sci Pollut Res Int 2021 Jul 13;28(28):37371-37386. Epub 2021 Mar 13.

Key Laboratory of Hydraulic Machinery Transients (Wuhan University), Ministry of Education, Wuhan, 430072, China.

This study aims to augment the performance of a solar desalination unit. To experimental examine this idea, a modified solar still with three different microparticles doped in black paint-coated absorber were designed, fabricated, and tested in Jaipur, India. Three different microparticles such as copper, aluminum, and tin with particle size of 50-80 μm with weight concentration of 10% were doped in black paint and then coated on the absorber of solar still. The coated absorber of solar still were compared with the conventional solar still without any microparticle coating to obtain the effect of different coating materials on the water productivity, thermal performance, economic, and environment-economics analysis of solar still. The result showed that under the water depth of 1 cm, coating of copper, aluminum, and tin on absorber augmented the full-day water yield by 33.13, 22.18, and 11.53%, compared to conventional solar still without any coating. In addition, full-day energy and exergy efficiency of solar still with copper-coated absorber exhibited maximum values compared to all other solar stills, owing to the higher thermal conductivity and excellent solar-thermal conversion behaviors of copper. The cost of water per liter estimated through economic analysis was found to be US $ 0.0074 for conventional solar still, which was significantly reduced to US $ 0.0066 in the case of solar still with copper-coated absorber along with the payback time of 2.7 months. The environment-economic assessment estimated that solar still with copper-coated absorber plate has reduced the 13.19 tons of CO emission. It is concluded that augmented heat transfer rate from water basin to inner glass surface through utilization of microparticle coating would pave a pathway to develop energy-efficient low-cost solar-based desalination system.
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http://dx.doi.org/10.1007/s11356-021-12837-6DOI Listing
July 2021

A comparative energy and exergy efficiency study of hemispherical and single-slope solar stills.

Environ Sci Pollut Res Int 2021 Jul 6;28(27):35649-35659. Epub 2021 Mar 6.

Department of Electronic and Communication Engineering, College Perundurai, Erode, Tamil Nadu, India.

In this experimental work, a comparative energy and exergy efficiency study of hemispherical solar still and a single-slope solar still has been carried out. The experiments were conducted in southeast Algeria on 25-5-2020 and 3-6-2020 in the natural climatic environment, and daily accumulation of distilled water produced for both distilleries was measured. The maximum obtained cumulative yield of distilled products is equal to 5.38 kg/m/day for the hemispherical solar still, and 3.64 kg/m/day for the single-slope solar still. The overall daily productivity was improved by 47.96% for the hemispherical solar still compared to the single-slope solar still. The maximum daily energy efficiency of the single-slope solar still is 25.81%, and hemispherical solar still is 38.61%. Similarly, the maximum daily exergy efficiency of single-slope solar still is 1.8%, and hemispherical solar still is 3.1%. The main conclusion from the study is the hemispherical distillery greatly enhances productivity as compared to the single-slope distillate and gives more efficiency. Thus, the hemispherical solar still is recommended to be used to provide safe drinking water from salty water.
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http://dx.doi.org/10.1007/s11356-021-13161-9DOI Listing
July 2021

Effect of fins and silicon dioxide nanoparticle black paint on the absorber plate for augmenting yield from tubular solar still.

Environ Sci Pollut Res Int 2021 Jul 4;28(26):35102-35112. Epub 2021 Mar 4.

Department of Chemical Engineering, Hindustan Institute of Technology and Science, Chennai, Tamil Nadu, 603103, India.

The present study aims at enhancing the yield of tubular solar still (TSS) by employing fins and coating the absorber plate. We doped the SiO nanoparticles into black paint at the weight concentration ranging from 10 to 40%. The solar still was tested in a bright sunny climatic condition of Chennai, Indian (lat. 13° 08' N and long. 80° 27' E). Under transient heat flux conditions, water, basin, and TSS glass temperatures with and without fin were measured. The rate of heat transfer by convection between the water and absorber plate was increased. Results revealed that the basin and water temperatures were improved by 10.49% and 10.88%, respectively when using black paint with SiO nanoparticle in the concentration of 20%, coated on the absorber plate compared to that when using the ordinary black paint, while using the fins on the absorber plate enhanced the potable water produced by 55.18% when using 20% SiO nanoparticle compared to that of conventional TSS. The cost per liter of water produced using the flat and finned absorber coated using 20% SiO2 nanoparticle in black paint is found as 0.0187 and 0.012 $/L respectively.
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http://dx.doi.org/10.1007/s11356-021-13126-yDOI Listing
July 2021

Investigation on the performance enhancement of single-slope solar still using green fibre insulation derived from Artocarpus heterophyllus rags reinforced with Azadirachta indica gum.

Environ Sci Pollut Res Int 2021 Feb 25. Epub 2021 Feb 25.

Department of Mechanical Engineering, KPR Institute of Engineering and Technology, Arasur, Coimbatore, Tamil Nadu, 641 407, India.

The fruits and vegetable waste has become the highest compared with the production rate. These types of wastes had reached up to 70% by 2019-2020 as estimated by Food and Agriculture Organization (FAO). Improvisation of the performance of still using fibre insulation (Artocarpus heterophyllus rags and Azadirachta indica gum (AHRAIG)) has been carried out in this study. Potable water demand in arid areas is a vast problem where fresh water is very expensive. The proposed solar still (PSS) retains the basin temperature and raises the rate of evaporation. Rags are latex-like filament extracted from the waste of the jackfruit peels and an adhesive agent from Azadirachta indica tree. A comparison is made among still without insulation (SWI), still with polystyrene insulation (SPI) and still with fibre insulation (SFI) in producing the fresh water under same ambient conditions. The experiments result a promising yield of 9.3% rate of rise of potable water produced using AHRAIG insulation related to conventional still. The energy efficiency is premeditated as 26.45%, while the exergy efficiency is 4.07%. The production of the potable water reached 2.58 L/m for still with polystyrene insulation, 3.26 L/m for fibre insulation and 1.93 L/m for still without insulation, respectively.
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http://dx.doi.org/10.1007/s11356-021-13062-xDOI Listing
February 2021

Performance enhancements of conventional solar still using reflective aluminium foil sheet and reflective glass mirrors: energy and exergy analysis.

Environ Sci Pollut Res Int 2021 Feb 24. Epub 2021 Feb 24.

Department of Mechanical Engineering, KPR Institute of Engineering and Technology, Arasur, Coimbatore, Tamil Nadu, India.

Many researchers are seeking simple and successful solutions to increase the output from the solar distiller. In this research work, reflective mirrors and reflective aluminium foil sheet were fixed on inner surfaces of the single-slope solar distiller, leading to more water production. The presence of reflective mirrors and reflective aluminium foil sheet on inner surfaces of the solar distillate permits the reflection of solar radiation falling inside the basin. Experiments were carried out on three stills: the first distiller is conventional solar still with black painted walls (CSS-BPW); the second distiller is conventional solar still with reflective aluminium foil sheet walls (CSS-RAFW); and the third distiller is conventional solar still with reflective glass mirror walls (CSS-RGMW). The maximum total drinking water productions from the CSS, CSS-RAFW and the CSS-RGMW are 3.41, 5.1 and 5.54 kg/m, respectively. Compared to the CSS-BPW, the production of drinking water was increased by 68.57% when using the reflective glass mirrors and 48.57% when using the reflective aluminium foil sheet.
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http://dx.doi.org/10.1007/s11356-021-13087-2DOI Listing
February 2021

Phosphate bags as energy storage materials for enhancement of solar still performance.

Environ Sci Pollut Res Int 2021 May 7;28(17):21540-21552. Epub 2021 Jan 7.

Department of Mechanical Engineering, KPR Institute of Engineering and Technology, Arasur, Coimbatore, Tamil Nadu, 641407, India.

In this experimental work, the effect of cotton bags filled with phosphate on solar distillery performance has been investigated. In this study, 25 phosphate bags are evenly distributed (5 × 5) with a length equal to 50 cm in a wooden box called the modified solar still (MSS). This system was compared with the conventional solar still (CSS) in the same climatic conditions. Phosphate bags are placed vertically to increase the energy storage capacity, and the water's surface area since the capillaries inside the phosphate bags play an important role in increasing the energy storage capacity. Experiments were conducted at El Oued University in Algeria during April and May 2020, with 1 cm and 2 cm of saltwater depth. The cumulative yield of 5.27 and 4.87 kg was produced from the MSS at 1 cm and 2 cm of saltwater, respectively, while the cumulative yield of the CSS was 3.8 kg. The MSS's overall efficiency at 1 cm and 2 cm of saltwater was enhanced by 28 and 22.5%, respectively compared with the CSS. The presence of calcium and copper in phosphate stores the heat energy during morning and afternoon, and stored heat energy was released during evening. Finally, it can be concluded that increasing phosphate bags significantly enhances the productivity in solar distillation, increasing efficiency and productivity.
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http://dx.doi.org/10.1007/s11356-020-12018-xDOI Listing
May 2021
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