To develop comparative understanding on recent model of supercapacitor for various parameter valu... more To develop comparative understanding on recent model of supercapacitor for various parameter values. The different parameters addressed here are performance variables of supercapacitor. Greenhouse gas emission mitigation, waste minimization and green technologies are need of hour. Conclusively environment protection is essential now for sustainability of life. This paper focuses on how effectively simulation software called MATLAB-Simulink be used to develop optimized model of supercapacitor before fabricating the real device.
This article introduced a unique MPPT controller for thermoelectric generators. Our method uses a... more This article introduced a unique MPPT controller for thermoelectric generators. Our method uses a modified incremental conductance (IC) algorithm to track MPP efficiently. The proposed method is simple to install, fast-tracking, and stable. Traditionally, MPPT trades off steady-state and transition-state properties. Various designs flows are explored. The study’s common parameters are fast convergence, efficiency, and low oscillations. Use a proposed strategy that effectively handles these difficulties. The proposed methodology improves TEG MPPT efficiency and convergence times.
2020 3rd International Conference on Intelligent Sustainable Systems (ICISS), 2020
The recent developments in the field of energy storage made a significant impact on in transporta... more The recent developments in the field of energy storage made a significant impact on in transportation, industry and domestic applications. This review aims to develop comparative understanding on high energy density storage system called supercapacitor for various materials and methods explored recently. The different parameters addressed in this review are performance variables of supercapacitor and different material-method framework explored recently. Greenhouse gas emission mitigation, waste minimization and green technologies are need of hour for the planet blue. Conclusively environment protection is essential now for sustainability of life. This review focuses on how effectively environmental wastes have been used to develop green energy storage device for renewable applications.
Journal of emerging technologies and innovative research, 2018
Jaswanth Nakula, Raam Dheep* School of Electronics and Electrical Engineering, Lovely Professiona... more Jaswanth Nakula, Raam Dheep* School of Electronics and Electrical Engineering, Lovely Professional University, Punjab. Abstract Thermoelectric Generators (TEG) are solid state semiconductor devices which generates electrical energy directly from temperature difference. The TEG works on the principle of Seebeck effect. The most commonly used commercial TEG devices use Bismuth Telluride (Bi2Te3) as the thermoelectric material, and can work up to a maximum temperature of 300 C. This article gives an review on various organic and inorganic materials that can be used for thermo-electric generator applications. Introduction In 1821 Johann Seebeck discovered the Seebeck effect which means the when temperature difference (∆T) at the joint of two different metals resulting in current and created an electromotive force in the executed circuit [1]. The temperature difference (∆T) between metal joints can be raised up by raising up the voltage difference (∆V). The seebeck coefficient is denoted...
The Ultra Capacitor finds its application in lot of industrial applications. The super-capacitor ... more The Ultra Capacitor finds its application in lot of industrial applications. The super-capacitor (SC) behavior is used in a number of innovative applications. This paper deals with a circuit that uses battery and power electronics components to mimic the super-capacitor discharge behavior. That can be used to operate a (constant 5volt) d.c- d.c boost converter. This paper alsoreport the creation of a new ultra capacitor voltage decay structure with the help of power electronics components. By this new ultra-capacitor voltage decay circuit we can use it low voltage battery charging and other different voltage level application.
This paper presents circuit methodology in which a constant DC voltage source or power supply has... more This paper presents circuit methodology in which a constant DC voltage source or power supply has been given from which an exponentially decaying voltage can be generated by the application of buck converter circuit. The circuit methodology presented shows the generation of switching pulse of exponentially decaying duty ratio decaying from 1 to zero which will be used to operate the controlled switch of the buck converter. This in turn will result in the generation of output voltage which will follow the decay curve of the duty ratio. Also it must be kept in mind that the amplitude of the switching pulse must be high enough to trigger the controlled switch of the buck converter. This decaying voltage can be used in charging devices in which voltage decreases over time as the device charges or could be used to resemble the characteristic of discharging supercapacitor. The components used in the circuit have been specified. The current at the beginning of the exponentially decaying vo...
Groundwater contamination with heavy metals is considered as serious environmental hazard that af... more Groundwater contamination with heavy metals is considered as serious environmental hazard that affect the human society. Nano adsorbents incorporating magnetite nanoparticles provides promising alternative to facilitate removal of heavy metal ions from wastewater. The present work focuses on removal of chromium (VI) cationic metals from aqueous media using Polyvinyl Pyrrolidone (PVP)/Magnetite (Fe3O4) Nanocomposite (MNC). Magnetite nanoparticles are synthesized using chemical co-precipitation and grafted using polyvinyl pyrrolidone to form a magnetite nanocomposite. MNC were characterized with X-ray diffraction (XRD) and Infrared absorption spectrum (FT-IR) studies to affirm the formation and presence of polymeric functional groups of PVP/Magnetite nanocomposite. Batch experiments are carried out at exclusive concentration intervals to study about the adsorption efficiency of MNC on chromium (VI) cationic metal using U-Vis spectroscopy. The results obtained through adsorption studie...
Solar air heaters (SAHs) are the simplest form of nonconcentrating thermal collectors. SAHs utili... more Solar air heaters (SAHs) are the simplest form of nonconcentrating thermal collectors. SAHs utilize solar thermal energy to increase the temperature of air for thermal applications of less than 80 °C. The energy efficiency of SAHs is significantly low due to poor convective heat transfer between the absorber and the air medium. In this present study, it is aimed to increase the convective heat transfer by modifying the absorber and the type of air flow inside the duct. Experimental studies were performed to study about the energy and exergy efficiencies of SAH with the absorber of longitudinal circular fins. The thermal analysis of the SAH is evaluated for five mass flow rates of 30, 45, 60, 75, and 90 kg/h m2 flowing inside the duct of thickness 100 mm. The impact of the flow rate on the absorber and air temperature, temperature difference (ΔT), energy and exergy efficiencies, irreversibility, improvement potential, sustainability, and CO2 reduction potential is studied. The experi...
The increasing interest in solar thermal energy storage necessitates the identification of new la... more The increasing interest in solar thermal energy storage necessitates the identification of new latent heat based phase change materials (PCMs). Testing the reliability and corrosion of newly identified PCMs upon repeated thermal charging and discharging cycles helps to evaluate the long term feasibility of latent heat storage system. Phenyl acetic acid (PAA) is an organic PCM with phase transition temperature of 75-80°C and latent heat of 152 J/g. In this present work the thermal reliability on thermo-physical properties and corrosive nature of phenyl acetic acid is studied for 2000 accelerated thermal cycles. The experimental result shows that phase transition temperature and latent heat of fusion of PCM varies only ± 1-3% and also has less corrosive nature to aluminium and stainless steel than copper metal containers throughout the thermal cycles. This study also comprises of experimental investigation on thermal performance of solar air heater (SAH) with built-in latent heat thermal energy storage. The solar air heater with PCM has outlet air temperature higher than ambient by 2-13°C for 2.5 h and 1-8°C for 2 h after solar hours at the mass flow rate of 30 and 45 kg/hr.m 2 respectively. Therefore the newly identified phenyl acetic acid is a promising PCM for solar space heating applications due to good heat storage properties, long term thermal reliability and less corrosive nature.
Investigation on thermal reliability and corrosion characteristics of Glutaric acid as an organic... more Investigation on thermal reliability and corrosion characteristics of Glutaric acid as an organic phase change material for solar thermal energy storage applications,
Integration of appropriate thermal energy storage system plays a predominant role in upgrading th... more Integration of appropriate thermal energy storage system plays a predominant role in upgrading the efficiency of solar thermal energy devices by reducing the incongruity between energy supply and demand. Latent heat thermal energy storage based on phase change materials (PCM) is found to be the most efficient and prospective method for storage of solar thermal energy. Ensuring the thermal reliability of PCM through large number of charging (melting) and discharging (solidification) cycles is a primary prerequisite to determine the suitability of PCM for a specific thermal energy storage applications. The present study explains the experimental analysis carried out on two PCM's namely benzamide and sebacic acid to check the compatibility of the material in solar thermal energy storage applications. The selected materials were subjected to one thousand accelerated melting and solidification cycles in order to investigate the percentage of variation at different stages on latent heat of fusion, phase transition temperature, onset and peak melting temperature. Differential Scanning Calorimeter (DSC) was used to determine the phase transition temperature and heat of fusion upon completion of every 100 thermal cycles and continued up to 1000 cycles. Relative Percentage Difference (RPD%) is calculated to find out the absolute deviation of melting temperature and latent heat of fusion with respect to zeroth cycle. The experimental study recorded a melting temperatures of benzamide and sebacic acid as 125.09°C and 135.92°C with latent heat of fusion of 285.1 (J/g) and 374.4 (J/g). The maximum RPD for melting temperature and heat of fusion for benzamide was calculated as 0.02% and À14.83% whereas sebacic acid it was À0.85% and À6.06% upon 1000 thermal cycles. The study revealed that both benzamide and sebacic acid are potential candidates for thermal energy storage due to their superior thermal reliability characteristics even after one thousand thermal cycles.
Renewable energy sources are time-dependent in nature and the effective utilization of devices ba... more Renewable energy sources are time-dependent in nature and the effective utilization of devices based on renewable energy requires appropriate energy storage medium to commensurate the mismatch between energy supply and demand. Solar energy is the primary source of energy among renewable energy sources which can be used for a wide variety of electrical and thermal applications. Intermittent and unpredictable nature of solar energy generally necessitates a storage medium in between that stores energy whenever is available in excess and discharges energy whenever it is inadequate. Therefore, the storage of thermal energy becomes necessary in order to meet the larger energy demand and to achieve high efficiency. Thermal energy storage using latent heat-based phase change materials (PCM) tends to be the most effective form of thermal energy storage that can be operated for wide range of low-, medium-, and high-temperature applications. This chapter explains the need, desired characteristics, principle, and classification of thermal energy storage. It also summarizes the selection criteria, potential research areas, testing procedures, possible application, and case studies of PCM-based thermal energy storage system.
Thermal energy storage system plays a critical role in developing an efficient solar energy devic... more Thermal energy storage system plays a critical role in developing an efficient solar energy device. As far as solar thermal devices are concerned, there is always a mismatch between supply and demand due to intermittent and unpredictable nature of solar radiation. A well designed thermal energy storage system is capable to alleviate this demerit by providing a constant energy delivery to the load. Many research works is being carried out to determine the suitability of thermal energy storage system to integrate with solar thermal gadgets. This review paper summarizes the numerous investigations on latent heat thermal energy storage using phase change materials (PCM) and its classification, properties, selection criteria, potential research areas and studies involved to analyze the thermal-physical properties of PCM.
Biosynthesis of silver nanoparticles using the leaf extract of Amaranthus tristis was evaluated i... more Biosynthesis of silver nanoparticles using the leaf extract of Amaranthus tristis was evaluated in the present report. The biosynthetic approach of nanoparticles synthesis deserves merit in biomedical applications due to its better biocompatibility. The biosynthesized silver nanoparticle was embedded in PVA polymer matrix as dispersed phase to craft an Ag/PVA nanocomposite membrane. The silver nanoparticles and the Ag/PVA nanocomposite membrane were characterized by UV-Vis, FTIR, AFM, SEM and TEM analyses. The membrane was fabricated by varying the ratios of Ag nanoparticles and PVA. Further, these membranes were tested against airborne microbes by exposing in air and compared with the control PVA membrane. 2:8 ratio of Ag: PVA nanocomposite membrane was found to possess a good activity in prevention of microbial growth and hence was studied further and characterized. UV-Vis spectra exhibited the characteristic Surface Plasmon Resonance (SPR) peak at 452 nm for Ag nanoparticle and 442 nm for Ag/PVA nanocomposite membrane (2:8). The AFM analysis of the nanoparticles showed the presence of uniform sized nanoparticles with an average size of 20-40 nm. This size was further confirmed with TEM analysis and nanoparticles were found to exist in the same size range of 20-40nm. The membrane was further characterized by Energy Dispersive X-ray Spectroscopy (EDS) which confirmed the presence of Ag nanoparticles (24.3 weight% of Ag) in Ag/PVA nanocomposite membrane. The antimicrobial efficiency of Ag/PVA nanocomposite membrane and Ag nanoparticles were tested against Pseudomonas fluorescens and Klebsiella pneumonia.
The surging demand for thermal energy storage (TES) directs considerable attention towards the de... more The surging demand for thermal energy storage (TES) directs considerable attention towards the development of phase change materials (PCMs). This study has the objective to develop a eutectic PCM for effective cold thermal energy storage. The work involves preparation, thermophysical property analysis and experimental studies of a novel binary eutectic mixture. The technique of Differential Scanning Calorimetry is used in determination of thermophysical properties of the prepared eutectic. Results show that the 80:20 eutectic composition of lauryl alcohol and cetyl alcohol with melting temperature of 20.01°C and latent heat of 191.63 J g −1 is fit for use in cold thermal energy storage. The material also proves to have good thermal conductivity. Thermal stability and reliability studies which are carried out using accelerated thermal cycling tests and thermo gravimetric analysis provide positive reports for the new mixture. An experimental investigation on the effectiveness of the identified PCM is carried out by using it in a cold storage chamber. Experimental studies report a solid improvement in cold energy containment of the PCM incorporated storage chamber resulting in considerable energy savings.
Journal of emerging technologies and innovative research, 2018
This article is oriented to perform a comprehensive study on various modular multilevel converter... more This article is oriented to perform a comprehensive study on various modular multilevel converter (MMC) topologies and their properties for solar photovoltaic farms interconnected to power grid. These topologies are advantageous in terms of lower power dissipation on switching, less harmonics at the output, lower electromagnetic interference and are used in medium and high power delivery systems. The selection of particular topology depends upon the power rating and application based demand of converter. The MMC contributes to the improvement in power quality issues such as imbalance and distortions because of interconnection of systems.
To develop comparative understanding on recent model of supercapacitor for various parameter valu... more To develop comparative understanding on recent model of supercapacitor for various parameter values. The different parameters addressed here are performance variables of supercapacitor. Greenhouse gas emission mitigation, waste minimization and green technologies are need of hour. Conclusively environment protection is essential now for sustainability of life. This paper focuses on how effectively simulation software called MATLAB-Simulink be used to develop optimized model of supercapacitor before fabricating the real device.
This article introduced a unique MPPT controller for thermoelectric generators. Our method uses a... more This article introduced a unique MPPT controller for thermoelectric generators. Our method uses a modified incremental conductance (IC) algorithm to track MPP efficiently. The proposed method is simple to install, fast-tracking, and stable. Traditionally, MPPT trades off steady-state and transition-state properties. Various designs flows are explored. The study’s common parameters are fast convergence, efficiency, and low oscillations. Use a proposed strategy that effectively handles these difficulties. The proposed methodology improves TEG MPPT efficiency and convergence times.
2020 3rd International Conference on Intelligent Sustainable Systems (ICISS), 2020
The recent developments in the field of energy storage made a significant impact on in transporta... more The recent developments in the field of energy storage made a significant impact on in transportation, industry and domestic applications. This review aims to develop comparative understanding on high energy density storage system called supercapacitor for various materials and methods explored recently. The different parameters addressed in this review are performance variables of supercapacitor and different material-method framework explored recently. Greenhouse gas emission mitigation, waste minimization and green technologies are need of hour for the planet blue. Conclusively environment protection is essential now for sustainability of life. This review focuses on how effectively environmental wastes have been used to develop green energy storage device for renewable applications.
Journal of emerging technologies and innovative research, 2018
Jaswanth Nakula, Raam Dheep* School of Electronics and Electrical Engineering, Lovely Professiona... more Jaswanth Nakula, Raam Dheep* School of Electronics and Electrical Engineering, Lovely Professional University, Punjab. Abstract Thermoelectric Generators (TEG) are solid state semiconductor devices which generates electrical energy directly from temperature difference. The TEG works on the principle of Seebeck effect. The most commonly used commercial TEG devices use Bismuth Telluride (Bi2Te3) as the thermoelectric material, and can work up to a maximum temperature of 300 C. This article gives an review on various organic and inorganic materials that can be used for thermo-electric generator applications. Introduction In 1821 Johann Seebeck discovered the Seebeck effect which means the when temperature difference (∆T) at the joint of two different metals resulting in current and created an electromotive force in the executed circuit [1]. The temperature difference (∆T) between metal joints can be raised up by raising up the voltage difference (∆V). The seebeck coefficient is denoted...
The Ultra Capacitor finds its application in lot of industrial applications. The super-capacitor ... more The Ultra Capacitor finds its application in lot of industrial applications. The super-capacitor (SC) behavior is used in a number of innovative applications. This paper deals with a circuit that uses battery and power electronics components to mimic the super-capacitor discharge behavior. That can be used to operate a (constant 5volt) d.c- d.c boost converter. This paper alsoreport the creation of a new ultra capacitor voltage decay structure with the help of power electronics components. By this new ultra-capacitor voltage decay circuit we can use it low voltage battery charging and other different voltage level application.
This paper presents circuit methodology in which a constant DC voltage source or power supply has... more This paper presents circuit methodology in which a constant DC voltage source or power supply has been given from which an exponentially decaying voltage can be generated by the application of buck converter circuit. The circuit methodology presented shows the generation of switching pulse of exponentially decaying duty ratio decaying from 1 to zero which will be used to operate the controlled switch of the buck converter. This in turn will result in the generation of output voltage which will follow the decay curve of the duty ratio. Also it must be kept in mind that the amplitude of the switching pulse must be high enough to trigger the controlled switch of the buck converter. This decaying voltage can be used in charging devices in which voltage decreases over time as the device charges or could be used to resemble the characteristic of discharging supercapacitor. The components used in the circuit have been specified. The current at the beginning of the exponentially decaying vo...
Groundwater contamination with heavy metals is considered as serious environmental hazard that af... more Groundwater contamination with heavy metals is considered as serious environmental hazard that affect the human society. Nano adsorbents incorporating magnetite nanoparticles provides promising alternative to facilitate removal of heavy metal ions from wastewater. The present work focuses on removal of chromium (VI) cationic metals from aqueous media using Polyvinyl Pyrrolidone (PVP)/Magnetite (Fe3O4) Nanocomposite (MNC). Magnetite nanoparticles are synthesized using chemical co-precipitation and grafted using polyvinyl pyrrolidone to form a magnetite nanocomposite. MNC were characterized with X-ray diffraction (XRD) and Infrared absorption spectrum (FT-IR) studies to affirm the formation and presence of polymeric functional groups of PVP/Magnetite nanocomposite. Batch experiments are carried out at exclusive concentration intervals to study about the adsorption efficiency of MNC on chromium (VI) cationic metal using U-Vis spectroscopy. The results obtained through adsorption studie...
Solar air heaters (SAHs) are the simplest form of nonconcentrating thermal collectors. SAHs utili... more Solar air heaters (SAHs) are the simplest form of nonconcentrating thermal collectors. SAHs utilize solar thermal energy to increase the temperature of air for thermal applications of less than 80 °C. The energy efficiency of SAHs is significantly low due to poor convective heat transfer between the absorber and the air medium. In this present study, it is aimed to increase the convective heat transfer by modifying the absorber and the type of air flow inside the duct. Experimental studies were performed to study about the energy and exergy efficiencies of SAH with the absorber of longitudinal circular fins. The thermal analysis of the SAH is evaluated for five mass flow rates of 30, 45, 60, 75, and 90 kg/h m2 flowing inside the duct of thickness 100 mm. The impact of the flow rate on the absorber and air temperature, temperature difference (ΔT), energy and exergy efficiencies, irreversibility, improvement potential, sustainability, and CO2 reduction potential is studied. The experi...
The increasing interest in solar thermal energy storage necessitates the identification of new la... more The increasing interest in solar thermal energy storage necessitates the identification of new latent heat based phase change materials (PCMs). Testing the reliability and corrosion of newly identified PCMs upon repeated thermal charging and discharging cycles helps to evaluate the long term feasibility of latent heat storage system. Phenyl acetic acid (PAA) is an organic PCM with phase transition temperature of 75-80°C and latent heat of 152 J/g. In this present work the thermal reliability on thermo-physical properties and corrosive nature of phenyl acetic acid is studied for 2000 accelerated thermal cycles. The experimental result shows that phase transition temperature and latent heat of fusion of PCM varies only ± 1-3% and also has less corrosive nature to aluminium and stainless steel than copper metal containers throughout the thermal cycles. This study also comprises of experimental investigation on thermal performance of solar air heater (SAH) with built-in latent heat thermal energy storage. The solar air heater with PCM has outlet air temperature higher than ambient by 2-13°C for 2.5 h and 1-8°C for 2 h after solar hours at the mass flow rate of 30 and 45 kg/hr.m 2 respectively. Therefore the newly identified phenyl acetic acid is a promising PCM for solar space heating applications due to good heat storage properties, long term thermal reliability and less corrosive nature.
Investigation on thermal reliability and corrosion characteristics of Glutaric acid as an organic... more Investigation on thermal reliability and corrosion characteristics of Glutaric acid as an organic phase change material for solar thermal energy storage applications,
Integration of appropriate thermal energy storage system plays a predominant role in upgrading th... more Integration of appropriate thermal energy storage system plays a predominant role in upgrading the efficiency of solar thermal energy devices by reducing the incongruity between energy supply and demand. Latent heat thermal energy storage based on phase change materials (PCM) is found to be the most efficient and prospective method for storage of solar thermal energy. Ensuring the thermal reliability of PCM through large number of charging (melting) and discharging (solidification) cycles is a primary prerequisite to determine the suitability of PCM for a specific thermal energy storage applications. The present study explains the experimental analysis carried out on two PCM's namely benzamide and sebacic acid to check the compatibility of the material in solar thermal energy storage applications. The selected materials were subjected to one thousand accelerated melting and solidification cycles in order to investigate the percentage of variation at different stages on latent heat of fusion, phase transition temperature, onset and peak melting temperature. Differential Scanning Calorimeter (DSC) was used to determine the phase transition temperature and heat of fusion upon completion of every 100 thermal cycles and continued up to 1000 cycles. Relative Percentage Difference (RPD%) is calculated to find out the absolute deviation of melting temperature and latent heat of fusion with respect to zeroth cycle. The experimental study recorded a melting temperatures of benzamide and sebacic acid as 125.09°C and 135.92°C with latent heat of fusion of 285.1 (J/g) and 374.4 (J/g). The maximum RPD for melting temperature and heat of fusion for benzamide was calculated as 0.02% and À14.83% whereas sebacic acid it was À0.85% and À6.06% upon 1000 thermal cycles. The study revealed that both benzamide and sebacic acid are potential candidates for thermal energy storage due to their superior thermal reliability characteristics even after one thousand thermal cycles.
Renewable energy sources are time-dependent in nature and the effective utilization of devices ba... more Renewable energy sources are time-dependent in nature and the effective utilization of devices based on renewable energy requires appropriate energy storage medium to commensurate the mismatch between energy supply and demand. Solar energy is the primary source of energy among renewable energy sources which can be used for a wide variety of electrical and thermal applications. Intermittent and unpredictable nature of solar energy generally necessitates a storage medium in between that stores energy whenever is available in excess and discharges energy whenever it is inadequate. Therefore, the storage of thermal energy becomes necessary in order to meet the larger energy demand and to achieve high efficiency. Thermal energy storage using latent heat-based phase change materials (PCM) tends to be the most effective form of thermal energy storage that can be operated for wide range of low-, medium-, and high-temperature applications. This chapter explains the need, desired characteristics, principle, and classification of thermal energy storage. It also summarizes the selection criteria, potential research areas, testing procedures, possible application, and case studies of PCM-based thermal energy storage system.
Thermal energy storage system plays a critical role in developing an efficient solar energy devic... more Thermal energy storage system plays a critical role in developing an efficient solar energy device. As far as solar thermal devices are concerned, there is always a mismatch between supply and demand due to intermittent and unpredictable nature of solar radiation. A well designed thermal energy storage system is capable to alleviate this demerit by providing a constant energy delivery to the load. Many research works is being carried out to determine the suitability of thermal energy storage system to integrate with solar thermal gadgets. This review paper summarizes the numerous investigations on latent heat thermal energy storage using phase change materials (PCM) and its classification, properties, selection criteria, potential research areas and studies involved to analyze the thermal-physical properties of PCM.
Biosynthesis of silver nanoparticles using the leaf extract of Amaranthus tristis was evaluated i... more Biosynthesis of silver nanoparticles using the leaf extract of Amaranthus tristis was evaluated in the present report. The biosynthetic approach of nanoparticles synthesis deserves merit in biomedical applications due to its better biocompatibility. The biosynthesized silver nanoparticle was embedded in PVA polymer matrix as dispersed phase to craft an Ag/PVA nanocomposite membrane. The silver nanoparticles and the Ag/PVA nanocomposite membrane were characterized by UV-Vis, FTIR, AFM, SEM and TEM analyses. The membrane was fabricated by varying the ratios of Ag nanoparticles and PVA. Further, these membranes were tested against airborne microbes by exposing in air and compared with the control PVA membrane. 2:8 ratio of Ag: PVA nanocomposite membrane was found to possess a good activity in prevention of microbial growth and hence was studied further and characterized. UV-Vis spectra exhibited the characteristic Surface Plasmon Resonance (SPR) peak at 452 nm for Ag nanoparticle and 442 nm for Ag/PVA nanocomposite membrane (2:8). The AFM analysis of the nanoparticles showed the presence of uniform sized nanoparticles with an average size of 20-40 nm. This size was further confirmed with TEM analysis and nanoparticles were found to exist in the same size range of 20-40nm. The membrane was further characterized by Energy Dispersive X-ray Spectroscopy (EDS) which confirmed the presence of Ag nanoparticles (24.3 weight% of Ag) in Ag/PVA nanocomposite membrane. The antimicrobial efficiency of Ag/PVA nanocomposite membrane and Ag nanoparticles were tested against Pseudomonas fluorescens and Klebsiella pneumonia.
The surging demand for thermal energy storage (TES) directs considerable attention towards the de... more The surging demand for thermal energy storage (TES) directs considerable attention towards the development of phase change materials (PCMs). This study has the objective to develop a eutectic PCM for effective cold thermal energy storage. The work involves preparation, thermophysical property analysis and experimental studies of a novel binary eutectic mixture. The technique of Differential Scanning Calorimetry is used in determination of thermophysical properties of the prepared eutectic. Results show that the 80:20 eutectic composition of lauryl alcohol and cetyl alcohol with melting temperature of 20.01°C and latent heat of 191.63 J g −1 is fit for use in cold thermal energy storage. The material also proves to have good thermal conductivity. Thermal stability and reliability studies which are carried out using accelerated thermal cycling tests and thermo gravimetric analysis provide positive reports for the new mixture. An experimental investigation on the effectiveness of the identified PCM is carried out by using it in a cold storage chamber. Experimental studies report a solid improvement in cold energy containment of the PCM incorporated storage chamber resulting in considerable energy savings.
Journal of emerging technologies and innovative research, 2018
This article is oriented to perform a comprehensive study on various modular multilevel converter... more This article is oriented to perform a comprehensive study on various modular multilevel converter (MMC) topologies and their properties for solar photovoltaic farms interconnected to power grid. These topologies are advantageous in terms of lower power dissipation on switching, less harmonics at the output, lower electromagnetic interference and are used in medium and high power delivery systems. The selection of particular topology depends upon the power rating and application based demand of converter. The MMC contributes to the improvement in power quality issues such as imbalance and distortions because of interconnection of systems.
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