Energy and Exergy for Sustainable and Clean Environment, Volume 1

The energy demand due to the population growth and the exhaustible nature of fossil fuels led to the research and development in the grid integrated renewable energy system. The power electronic interfaces play a vital role for this integration. But the power electronic interfaces and the generally used non-linear loads like switched mode power supplies affect the power quality by making the non-sinusoidal grid current. In order to make the grid current sinusoidal, a controller is essential to govern the power electronic interface. In this work, a solar photovoltaic system is integrated to grid through inverter. Depending upon the weather conditions, the power generation in the solar photovoltaic system varies. This uncertainty is investigated as three cases in this work. They are nil generated power, insufficient generated power, and excess generated power to feed the load. A proportional-resonant controller is employed in this work to handle these cases and also to improve the quality of power. The simulation is performed in MATLAB/SIMULINK environment and the results are presented to validate the cases.

Demand for renewable energy is enhancing nowadays due to the higher amount of growth in the industrial sector and its impact on the environmental. It was found that power plants based on solar sources are one of the important environment-friendly energy generation systems which uses solar energy for power generation. Out of that, the parabolic solar collector is the most efficient one (PTCs). Till now, various studies have been done to improvise the thermal characteristics of PTC by introducing various types of tabulating inserts or modifying the design of the trough collector tube. In the present study, a comparative analysis between the performance of normal absorber tube and spiral absorber tube of PTC is performed considering the receiver tube length as 1 m and inner as well as outer diameter as 27.5 mm and 30 mm, respectively. One model has been simulated for a 1 m long spiral absorber with 15 turns and results were compared with the results obtained with a straight absorber tube with a mass flow rate within the range of 1.5–15 L/min (0.025–0.25 kg/s). Ambient temperature was considered as the inlet temperature within the range of 298–310 K. The models were made in ANSYS 14.0 (Design Modeler) and then the flow analysis was done in fluent. The temperature at the outlet was found to be 341 K for the absorber tube with 15 turns of a 1 m long tube at 1.5 L/min (0.025 kg/s), whereas under the same inlet condition, the outlet temperature for the straight absorber tube was found to be 318 K. It was found by introducing the spiral absorber tube that there is an enhancement of exergy efficiency, thermal efficiency, and overall efficiency within 15–20% and the operating pressure was found within the range of 2.3–5.64 bar.

Primary energy sources are running out with the increase in electrical energy consumption. Energy is the key driver to the growth in any economy. One of the biggest challenges today is to meet the continuously rising demand for energy. Renewable energy serves as a solution to the above issue. Renewable energy site selection is a Multiple Criteria Decision-Making (MCDM) problem. MCDM is a complex Decision-Making (DM) tool. This context relates to the optimal site selection for solar power plant (SPP). The SPP selection of site relies on a set of qualitative and quantitative criteria, which are uncertain. The objective of this paper is to enable policy-maker to achieve the best potential SPP installation site focusing on attributes such as solar radiation, temperature, distance from the road, distance from the protected area and sunshine hour. This paper reviews an MLP-BP algorithm to carry out site selection for SPP in Rajasthan, West Bengal and Karnataka, and results are obtained as the weight of the output and attributes its class as good, fair and poor. This algorithm helps in simplicity for the site selection for utility-scale Photovoltaic (PV) solar energy systems by considering the important criteria for the decision process.

Now a days, vigorous population growth, sudden climatic changes and etc. leads to drinking water scarcity, thus becoming challenging task to researchers as days pass on. Addition to that non-renewable energy crisis mandates the use of renewable energy and mainly solar which is abundantly available and cost free in production in desalination which increasing sustainability. Due to less production rate of solar stills, many researchers are contributing to increase by optimizing different parameters. Research had been done in optimizing the partitioned at bottom and at top in solar still to increase its performance and flow pattern. In this research, the baffle is introduced inside the partitioned solar still and analyzing the flow pattern before and after introducing the baffle. First, the solar still is analyzed without baffle and compared with introducing baffle and furthermore by introducing in modified stills. It will be then analyzed and the changes in productivity recorded. As the amount of Rayleigh number raises the solar still productivity may progressively increase as it is changed at the condensing surface into multiple curves. But the performance of the still with baffle is way far low than the still without baffle because the flow alignment/confinement can only be done in one side of the still and not in both the sides of the still.

The awareness about limited energy resources has urged the scientific community to scrutinize the energy conversion devices and optimize existing limited resources. In this analytical study, the exergetic performance analysis of a triangular cross-section square ribbed solar air heater (SAH) is compared with a conventional SAH. Reynolds number (Re) and temperature rise parameter (∆T/G) are varied, and their effect on exergetic efficiency is quantified. For the present study, maximum exergetic efficiency for the present study is obtained for non-dimensionalized rib height (e/D) of 0.05 and non-dimensionalized rib pitch (P/e) of 10. The optimum combinations of roughness parameters are interpreted through plots to design turbulators for triangular cross-section solar air heaters.

The paper focuses on the flow and performance analysis of diverged chimney-based solar updraft tower (DCSUT) plant. It investigates the effect of chimney divergence angle (θch), ambient temperature (Tamb) and solar flux (I) variation on the system performance. A 3D computational domain of DCSUT plant was modelled. Turbulence and radiation models were considered for evaluating the flow and performance characteristics. The results from the study look promising and found that the optimum performance of the SUT plant was noticed at θch of 2°. The velocity of air and power potential of the system was enhanced by 59.4% and 312.5%, respectively, than θch of 0°. The increase in I and Tamb also enhanced the flow and power potential of the plant. Due to an increase in Tamb from 293 to 318 K, the air velocity at the chimney base (CB) increased from 2.3 to 4.9 m/s (which is 113% enhancement). The collector temperature increases from 313.4 K to 350.4 K with an increment in I from 600 to 1200 W/m2. The velocity of air near CB, temperature, power potential and overall efficiency of the plant were determined as 3.52 m/s, 315.9 K, 1.62 W and 0.0112%, respectively. Furthermore, the optimized data of the DCSUT plant was compared with the conventional cylindrical chimney-based solar updraft tower (CCSUT) plant and found good matches.

In general, a majorly accepted method of converting solar energy into thermal energy is by using flat plate collectors. The elementary function of these collectors is to heat water at a certain temperature by using solar energy and yield the hot water at a higher temperature can be used for boiling the vegetables by solar cooking, for yielding the saline water from the salty water by using solar desalination and for space heating and cooling by using solar refrigeration and air conditioning processes. In this paper, an attempt has been made to increase the water outlet temperature by adding a plane mirror or reflector along the North–South direction at the same tilting angle of the flat plate collector. Experiments were also conducted with and without reflector on the same collector by varying the mass flow rates, and at different solar insolation. It is noticed that with the added secondary reflector, the solar water heater's overall instantaneous collector efficiency is more than the plain solar flat plate water heater. It is clearly observed that even though the added weight for the collector by the inclusion of the reflective mirrors, but eventually boost the outlet temperature at 5° and 8% of enhancement in conversion efficiency of the collector.

This paper discusses the concept of a PV (photovoltaic integrated grid) system. MPPT technique based on proportional integration (PI) is used to derive maximal power from the PV Module. PV system performance is influenced by the irradiations and temperature of the atmosphere. The PI control has played a major role in enhancing the PV system performance response. The duty cycle is developed using an MPPT integrated PI controller for the DC–DC boost converter. Sine cosine algorithm (SCA) is implemented to increase the performance response of the developed PV module to the proposed controller's gain parameter. The efficiency of the PI controller on the basis of the MPPT is higher than the traditional P&O techniques. The proposed PI-based MPPT technique for optimization showed that the proposed PV method improved in terms of time response.

Commercial laundries are great candidates to study, analyze, and redesign in terms of multigeneration, integration, and waste heat recovery. Large-scale laundry processes might seem simple yet are very energy intensive and highly inefficient in terms of energy management. Laundry processes rely on unsustainable energy sources such as diesel and a significant amount of waste heat is lost in the form of steam. This research aims to study the feasibility of transforming a commercial laundry facility located in Qatar into a renewable-energy-based multigeneration system and to analyze it through energy and exergy analysis. In this study, a CSP/T-based integrated energy system is developed and analyzed. The system is proposed to produce electric power, thermal energy, compressed air, cooling, and water. The system is integrated with compressed air energy storage and absorption cooling system for space cooling purposes. In addition, a parametric study is performed to investigate the effect of varying certain parameters such as atmospheric temperature, solar heat transfer fluid temperature, mass flow rate of heat transfer fluid, solar irradiance, space cooling temperature, organic Rankine cycle turbine pressure ratio, etc. on the performance of the proposed system. The designed system is capable of generating about 8 MW thermal energy at 800 W/m2 solar irradiance. This thermal energy generated from the CSP/T subsystem is utilized for the required electricity production of about 1.3 MW via an organic Rankine cycle as well as required steam production of 0.1 kg/s. In addition, compressed air is produced and stored in a compressed air energy storage (CAES) unit, where the heat content of this compressed air is initially utilized to provide the necessary heat for the absorption cooling cycle to produce a space cooling load of about 210 kW.

These days biodiesels are an advancement for substitute employments of petroleum derivatives. In this work, an experiment was carried out at 1500 rpm in a CI engine, where Undi biodiesel was utilized at a proportion of 10 and 20% in 90 and 80% diesel, respectively. The analysis was directed in a diesel engine at 4, 8, and 12 kg loads. The engine parameters such as BThE, UHC, and NOx of the used two blends were compared with diesel. UHC emission resulted less for both blends compared to diesel at max loads. BThE was higher for 10% biodiesel and 90% diesel, however, NOx was higher for the two mixtures compared to diesel. Analytical hierarchy process (AHP) was additionally executed to discover the most effective fuel mix among all the fuels (pure diesel and 10, 20% mixtures of the Undi biodiesel with 90 and 80% diesel, respectively), which were implemented within the engine and the AHP model demonstrated Blend 1 (i.e., Undi biodiesel 10% and diesel 90%) was the optimum fuel within the utilized fuel mixes.

The aim of this work is to optimize the injection pressure (Pi), injection timing (Ti), and blend ratio (Bl) of a Kirloskar, air-cooled, single-cylinder, 4.3 kW, 4-stroke direct injection diesel engine, with a compression ratio of 17.5:1, at a constant speed of 1500 rpm at full load condition. The 3-hole nozzle was used to inject the fuel. The free fatty acid methyl esters (FAME) were derived from refined palmolein oil using the transesterification process. The FAME and diesel were blended in different proportions and used as the fuel. Based on the design of experiments, the experiments were designed using statistical analysis like metamodeling and aimed to reduce the emission and increase the performance of the engine. For the study, the injection pressure, injection timing, and blend ratio were the input controlled parameters, and carbon monoxide (CO), hydrocarbon (HC), carbon-dioxide (CO2), and nitrogen oxides (NOx) were output responses. In order to identify the optimal interaction between the input and the output responses, the desirability-based approach was used. The optimal values of the refined palmolein methyl esters were found to be: (i) injection pressure of 232 bar, (ii) injection timing of 23○ BTDC, and (iii) the blend ratio of B29. The optimum values of the CO, HC, CO2, opacity, NOx, BSFC, and BTE were found to be 0.04%, 17 ppm, 6.9%, 25.1%, 1263.07 ppm, 0.0263 kg/Kw h, and 35.59%, respectively.

The transport requirement in India is enormously increasing, which stimulates the energy utilization by 4.1–6.1% rise every year from 2010 to 2050. Additionally, the number of private vehicles keeps on increasing every year and consumes more fuel which makes India the third largest foreign buyer of crude oil in the world. Owing to this issue, the promotion of alternative fuels (biodiesel) which are from different feedstocks for transportation is necessary. These biodiesels hold enhanced emission characteristics compared with neat diesel, therefore the biodiesel can be considered as a substitute for diesel and if blended with diesel, it gives enhanced performance characteristics. Tests on the performance of the engine were carried out at different numbers of holes, different weight percentages of blends, and different loads. The objective of this work is to identify the optimal process parameter, which minimizes the Brake-Specific Energy Consumption (BSEC) and maximizes the Brake Thermal Efficiency (BTE). The experiments were designed based on the RSM Design of experiments. Using the RSM desirability function, the process parameters are optimized for better performance. The influence of process parameters on responses is investigated using ANOVA. The blending ratio has the maximum percentage contribution of 44% for BSEC and the number of holes has the maximum percentage contribution of 39.85% for BTE. The optimal parameters of four holes in the fuel injector, 40% of biodiesel with 60% of diesel, and 100% of load are identified.

In this paper, the performance and emission characteristics were studied for a CI engine that was fueled with cottonseed oil blended with diesel in different ratios, i.e., B10, B20, and B30, and also another combination with the addition of 10% of kerosene in all the blends. This experiment was performed with the help of a four-stroke single cylinder diesel engine with a load variation from 4 to 16 kg. The results obtained showed that the addition of cottonseed oil (CSO) slightly reduced the brake thermal efficiency with an increase in specific fuel consumption and lowered exhaust gas temperature. With an increase in the amount of cottonseed oil, the emission parameters reduced (CO, O2, CO2, and NOx) with an increase in hydrocarbon emission. The same results were also observed with the addition of kerosene. Hence, satisfactory results were obtained with combustion characteristics improving with the increase of load.

The need for an alternative fuel with biodegradability, low toxicity, and long-term sustainability has prompted a surge in biodiesel research in recent years. Bean oils, animal fats, microalgal oils, and waste materials such as food manufacturing waste and cooking oils were biodiesel feedstocks. A detailed understanding of the factors affecting the process of extraction and their relative importance is needed. The current study investigates the manufacture of biodiesel from Punnai crude, a nonedible oil. A three-stage method for the development of biodiesel is addressed, including pre-treatment, alkali, and acid catalyzed transesterification. For biodiesel extraction, reaction parameters such as the molar ratio (methanol to oil), catalyst concentration, reaction temperature, and reaction time have been optimized. Under optimal conditions, the yield of biodiesel from punnai oil is observed to be 85%.

Light-emitting diode (LED) based luminaires have brought a drastic change in the lighting world by conquering and replacing the earlier used incandescent and fluorescent bulbs. At the present time, they are used almost everywhere from street lights to industries, from household applications to artificial lighting. LED-based luminaire emits direct light and hence needs to be diffused. An ideal diffuser for a luminaire would hide the appearance of the light source behind it and scatter all light within a specified beam distribution with no backscatter or absorption. Another ideal property for such a diffuser would be controllable anisotropic scattering which could be tailored according to the particular needs. This study focuses on the importance of diffusers and lenses in low-wattage white-LED-based DC luminaire. LED-based DC luminaire has been considered for the experiment because the wattage of these luminaires are lesser compared to the AC one and the focus of this experiment is to give preference in the application of the solar photovoltaic system. The experiments performed with different diffusers and lenses show that these cannot be used to improve the efficacy of the system but are important to prevent consumers from the negative effects of white light. The effect of diffusers and lenses on various optical parameters like CCT, CRI, and luminous flux has also been studied.

The power structure incorporating of sustainable power source, customary fuel source, and fuel supply is a great choice for giving power to far-off areas where admittance to regional grid isn’t achievable or prudent. Dependability and cost-viability are the two most significant targets for planning a hybrid power system (HPS). The expense execution and dependability of power supply are broken down for a miniature coordinated micro-integrated HPS (MIHPS) made out of sun-powered photovoltaic (PV), diesel generator (DG), and batteries (BAT) in different framework designs. The size and limit of power sources are figured for system reliability based on loss of power supply probability (LPSP). The impact of fluctuating PV, DG sizes, and BAT limits on reliability of power supply (as LPSP) and cost of energy (CoE) are altogether surveyed in different structures. The MIHPS of various designs and sizes are considered for the least CoE at worthy LPSP. The satisfactory LPSP is kept invariant at  < 0.001 (likeness 99.9% power supply reliability) for the investigations. The precise methodology of estimating the power sources through execution of guaranteeing adequate power supply dependability is the purpose of the current investigation.

In the escalating load demand scenario, the need for incorporating the additional regional generating sources is essential which further increases the complexity of the power network. The oscillations injected due to the injection of energy sources to the existing grid will lead to maloperation of remaining system components that is not permissible. This paper presents a rigorous analysis on the impact of installing additional energy systems to the existing grid and suggests suitable methods to get rid of it. The study on various techniques has been studied and appropriate techniques have been presented in this paper. The techniques presented in this paper cover a traditional power system stabilizer (PSS), installation of flexible AC transmission system (FACTS) controllers, optimized controller parameters and robust controller technique. A sample power system has been designed and the proposed techniques are compared with the modern optimized stabilization techniques. The study on FACTS devices and robust controller have been presented which has resulted better performance over the CPSS and optimized PSS controller parameters for a variety of system operating conditions.

Fossil fuels are depleting at an alarming rate. Keeping that in mind, present-day research is highly aimed at energy generation from renewable sources such as sun, wind, running water, biomass, etc. The present work aims at performing an optimisation analysis of a hybrid energy system (HES) to be used for energy supply to type VI faculty quarters at the National Institute of Technology, Silchar, India. For the present scenario, a hybrid energy system consists of solar or photovoltaic (PV) energy system, wind energy conversion system (WECS), biomass gasifier, battery bank and diesel generator. The HES is considered to be the only source of energy thereby replacing grid-based power supply to the quarters. In order to analyse the required energy by the quarters, an energy requirement curve is plotted for 12 different months. Based on the requirement, different types of solar panels, wind turbines, battery banks, etc., are chosen based on area, material, cost and power output. Multiple-criteria decision-making (MCDM) techniques are applied to evaluate the most optimal combination of energy sources for the present case. Two MCDM techniques are applied, namely, Fuzzy TOPSIS (Technique for Order of Preference by Similarity to Ideal Solution) and Grey Relation Analysis (GRA). Fuzzy TOPSIS results show that solar–diesel–battery combination is the optimal configuration for energy supply, whereas GRA solar–diesel–biomass is the optimal combination.

Photovoltaic cells (PVc), as an energy provider to the next generation and the biggest source of renewable energy. Since last decade, improving efficiency and reducing the cost of PVc has been a subject of active research among scientists. Promising progress in the field of material science and manufacturing process at nanolevel played a big role. Still, at present, there are many challenges before photovoltaics for efficient and economic energy. However, photovoltaic cells based on p–n type homojunction semiconductors with different organic and inorganic materials reported thus generally suffer from poor performance. According to the available literature, colloidal quantum dots having immense properties like a wide range of light absorption, easily charge separation and transport. To utilize the maximum part of the spectrum of solar energy reaching to the earth and making effective energy production, here we introduce the complete cell architecture and numerical investigation on quantum dot-based solar cells (QDSCs) with a heterostructure multijunction approach. Successive ionic layer adsorption at different heterogeneous interfaces was analyzed. We majorly focused on improving the electrical and optical properties of the QDSCs achieved by different materials and structural approaches. Here, we report a heterostructure II-Type of band alignment engineering strategy for QDSCs interfaces that significantly enhances the efficiency descriptors. In the context of intermediate band solar cell (IBSC), we investigated optical properties of QDs and strain effects on multilayer PVc and we summarize the strain effect in QDs growth and local energy band bending of conduction band (CB) and valence band (VB).

A large portion of the energy input to an LED lamp, usually about 70%, is dissipated as heat. A suitable arrangement is necessary to transfer this heat to the ambient and a radial heat sink may be an attractive option. Thermal performance of radial heat sink has been carried out numerically considering free convection as the sole mode of energy transport. The heat sink base is placed horizontally upon which a number of plate fins are attached at equal angular space. The heat sink draws the surrounding air toward it. The air enters the heat sink nearly horizontally which then removes the heat from the LED, becomes warmer and finally goes out from the heat sink almost vertically. Fins appreciably augment the rate of heat dissipation over that of the smooth circular plate. Effect of the variables such as Grashof number, number of fins, and fin height on heat losses from heat sink has been studied. Heat transfer monotonically rises with rise in Grashof number and fin height. But with increasing fin number, the improvement in heat transfer is not monotonic. At a given Gr and fin height, maximum heat transfer occurs at a particular fin number. For most of the realistic cases, 20 numbers of fins are a worthy choice with fin length equal to radius of the base plate.

The development of a country depends upon the availability of energy sources for power generation and utilization in end-use sectors. Use of renewable energy sources are gaining more attention for sustainable future of energy future. At present solar, wind, and biomass are the main renewable energy sources that are using for power generation. However, renewable energy sources are intermittent and dependent on the availability. In view of the continuous power requirement for buildings in educational institutes, current work is concentrated on design of optimal Hybrid Renewable Energy System (HRES). Two different hybrid renewable energy systems such as solar-wind and solar-biomass are considered for meeting the building energy demand of an educational institute in Vizianagaram, India. The building hourly, daily, monthly, and yearly energy demand is estimated. Solar energy is assessed using NASA (National Aeronautics and Space Administration). The Vizianagaram biomass web portal is used to assess the availability of biomass. A thorough survey is done for selecting different components such as PV panel, wind turbine, biomass generator, battery, and converter based on the economic and technical aspects. Optimization and sensitivity analysis of the hybrid renewable energy system is done using HOMER software. The results are analyzed with the help of life cycle cost, capital cost, cost of energy (COE), total annual power generation, and monthly average power production. Optimization of hybrid energy system is done using the net present cost (NPC). Further, the sensitivity analysis is implemented for understanding the effect of various parameters on the feasibility of hybrid energy system to provide the energy requirement of the building. It is seen that the solar–biomass hybrid energy system is providing the economic feasible solution for the meeting the electrical energy requirement of the building. The suggested hybrid energy system outcomes could be useful for implementing the hybrid energy system in similar buildings and availability of energy resources in the world for meeting the energy demand.

The complexity of Power system networks increase with energy demand. The real-time model plays a vital role in monitoring and control of the network. State estimation (SE) tools are essential to build the realistic models, to filter the redundant data, eliminate incorrect measurements, and produce reliable state estimates. It measures the power flow in various parts of the power system which are not directly metered. The bus voltage magnitude, real power injections, reactive power injections, active power flow, reactive power flow, and line current flows are common measurements available in SCADA systems. The main objective of the paper is to deal with dynamic state of the system. It mainly focuses on investigating the various operating conditions like normal operation, bad data measurement, and sudden load change/drastic generation variations for time-varying system states. Various linear and nonlinear Kalman filter techniques like Kalman filter, extended Kalman filter, and adaptive extended Kalman filter are proposed and applied. The case studies are performed on IEEE 14 bus system to study linear and nonlinear state estimators. The obtained results are compared by using Mean Absolute Percentage Error (MAPE) value and performance indices.

The load demand and usage of electricity is high in the present situation. To Monitor dynamic tariff and to warn consumer about his electric expense this “Energy meter with real time Electricity bill prediction” is used. It can give a remedy for the power and rate of consumption to the consumer. In this process, the meter pulses are fed into the program. The real-time units, daily usage of power (kWh) and money to be paid for consumed units are calculated and can be monitored in this meter. By using this, the user can limit the power (units) usage according to his requirement inorder to save his electric expense. Using this meter, the users need not separately calculate their day-to-day electric expense and no need to worry about their monthly bill as it is displayed time-to-time giving an idea over their monthly bill. This project warns in a way that he/she can start reducing his/her consumption at a particular time, and it also intimates him/her when their electricity bill is posted or generated as by observing if the count on LCD is reset it means the bill is generated by EB person.

In this paper, a novel method for energy modeling of normal Electroencephalography (EEG) signal using empirical mode decomposition (EMD) and autoregressive (AR) modeling is performed. The energy estimation is the well-accepted parameter for the analysis behavior of abnormal EEG signal. The EEG signal is decomposed into different intrinsic mode function (IMF) components by using the EMD method, which is a well-accepted algorithm to handle non-stationary, nonlinear signals like EEG. The Teager energy of the first IMF is fed to an AR model to estimate the model parameters using the Burg method. These estimated energy signals are compared with the original signal. The proposed energy model shows around 90% accuracy by means of the error signal in AR modeling.

Harmonics are important parameters which affect the performance of a three phase induction motor. Among these harmonics, the effects of even harmonics nullify each other. Therefore, the presence of odd harmonics will increase the energy losses of the motor and thereby decrease the exergy efficiency. The exergy of the system is the maximum work possible during the processes of energy conversion. The proposed wavelet packet transform is effectively used to extract and eliminate the higher order odd harmonics in the power supply system. Hence, it can reduce the energy losses such as hysteresis loss and eddy current loss. Therefore, the overall exergy efficiency of the system is improved. Here using the proposed method, a 3% increase in overall efficiency and 77% exergy efficiency of the motor is obtained.

Bioelectrochemical devices (BED) are used to harness energy as electricity from soluble organic matter using microorganisms as biocatalysts. The soluble organic matter gets oxidized by the microbes to liberate electrons in the BED electrode. The counter-charge carriers diffuse through a separator and get reduced at the counter-electrode where electrons are dispensed. Due to oxidation–reduction reactions, a potential difference develops across the electrodes and electrons flow via an external circuit generating bioelectricity. Thus, the power production capability is dependent on the components of BED, in particular the materials that separate the electrodes (termed as separators). The key purpose of the separator in a BED is to allow the passage of charge carriers (like electron or proton) without allowing the electron acceptors (oxidants) and soluble organic matter to diffuse or migrate between electrodes. Thus, the selection of separator has an important part toward the performance of a BED in terms of power production and overall cost. However, the use of expensive components restrains the acceptability and affordability of the technology. This paper reviews the performance of the different separator materials in BED and presents a case study involving the application of an alternative separator fabricated from low-cost material in BED. This study presented an overview of the various low-cost alternative separator materials along with conventional and widely used expensive membranes that are used in BED.

The main purpose of this paper is to give an idea of planning and designing an optimal Hybrid Renewable Energy System (HRES) for supplying electrical power to Jawaharlal Nehru Institute of Medical Science (JNIMS), Babina Diagnostics, and Aadarsh Medicare Service which are located at Porompat, Manipur in North East of India. The HRES is constructed using Hybrid Optimization Model for Electric Renewables (HOMER) Pro Software by considering Photovoltaic (PV), Wind Turbine (WT), Lead Acid Battery, and Diesel Generator (DG) as a backup power supply. All the required price of the components, daily load consumption data, hourly irradiation data of solar, and speed of the wind of the area are obtained for the simulation process of finding the optimal system which has a minimum Net Present Cost (NPC) and Cost of Energy (COE) for autonomous operation.

Praseodymium-doped ceria (PDC)-based electrolyte powder was synthesised by the hydrothermal method. The as-synthesised powder was studied by various powder characterisations such as X-ray diffraction (XRD), Raman spectroscopy and scanning electron microscopy (SEM) analysis to find out the crystallinity, phase, nature and structural morphology. The shrinkage behaviour (linear shrinkage and shrinkage rate) of PDC powder at high temperatures was performed by dilatometer studies. The crystallographic parameters including the crystallite size, lattice strain and lattice parameter were calculated from XRD analysis. Raman spectroscopy analysis revealed the characteristic peak at 460 cm−1 which corresponds to the F2g peak of the cubic phase of ceria and the peak at 550 cm−1 is attributed to intrinsic oxygen vacancies that confirmed the formation of ceria praseodymium solid solution.

Eco-anxiety is a very new concept which is not a fully defined and conceptualized research area. To date, eco-anxiety is defined as the state of heightened anxiety some people experience relating to climate change. Nowadays, it is common practice to hear an increasing number of people reporting on their negative experiences and attitude toward their environment; they become more aware of the impact we are having on our environment and our planet. Renewable energy is also the most cross-cutting research concept and practice advocated all over the world. In this study, it was attempted to connect those two concepts as a problem–solution model. Hence, this study was conducted at Humera city, Tigray, Ethiopia, mainly to explore the possible coping mechanism of eco-anxiety with special attention to renewable energy. Using convenience sampling, 500 dwellers of the city were asked to complete a background questionnaire, Generalized Attitude Measure (GAM), and a Generalized Belief Measure (GBM), and based on their results 10 persons were randomly selected for interview. Finally, using the GAM, the study revealed that a large number of the participants (76.5%, n = 382) had a negative attitude toward climate change. The GBM also revealed that 86.6% (n = 433) of the participants had a strong belief in renewable energy as the best way of coping strategy for eco-anxiety. This result was also corroborated by the semi-structured interview made with ten participants. Finally, possible recommendations for further researchers were also made.

Fluidized bed drying of ginger (Zingiber officinale) cubes (1 cm × 1 cm × 1 cm) with initial moisture content of 87% wet basis (wb) has been carried out at three different temperatures of 45, 50 and 60 °C. A thermodynamic study of the fluidized bed dryer to achieve final moisture content of below 7% (wb) has been presented. The activation energy and moisture diffusivity for the drying process have also been reported. Results showed that drying of ginger in fluidized bed dryer was an effective method that reduced the moisture content of samples of 1000 g to below 7% within 7 hours for all three drying air temperatures. The specific moisture extraction rate (SMER) was 0.3337–0.8368 kg/kWh. The theoretical thermal efficiency was 14.1%, 20.1% and 20.7% for drying air temperature of 45, 50 and 60 °C, respectively. While the overall average exergetic efficiency was significantly high in the range of 64.2–74.7% for specified drying air temperatures. The moisture diffusivity of ginger cubes increased with the rise in air temperature and was between 3.1117 × 10−9 and 3.2508 × 10−9 m2/s, while the activation energy was 73.46 kJ/mol. The calculated values of activation energy and moisture diffusivity were within the range for drying of food products when compared to similar studies in the literature.

Drying process is one of the tedious processes, which needs dynamic monitoring and control during operation. Temperature control plays a vital role in drying process industries. Dryers need a lot of process monitoring, and it is essential to model the temperature process of dryer before its control. Here, we have planned to model and implement adaptive control algorithm for the dryer process. Input will be the amount of feed-in given to the dryer conveyor, and the output will be temperature of heating or drying chamber. RTDs are used as temperature measuring element through which temperature data of drying chamber will be measured. The data will be acquired through a DAQ system and are used for modeling. The system identification procedure is utilized in this work to recognize the mathematical model of the process using the inputs and the yield obtained. After the utilization of identification procedure, the finest model set can be preferred and after that Model Reference Adaptive Controller (MRAC) and Internal Model Control (IMC) are to be implemented. The design of the dryer and its associated instrumentation, process modeling and controller design are to be done in MATLAB environment.

The increase in pollution across the world due to the usage of fossil fuels has been the talk of the town. As a result of these and for the replacement of petrol diesel vehicles, the EV vehicle has evolved recently due to its significant advantage. But the main source of energy for the EV vehicle is li-ion battery as petrol and diesel for automobile. These fossil fuels have drawbacks like pollution, depletion, and similarly EV vehicle source of energy which is the li-ion battery has main drawback of heating issues. Because of this heating effect there is a possibility of fast discharging process, low life cycle of batteries, etc. So to reduce the heat from the battery a Battery Thermal Management System (BTMS) is used. Under this air cooling, Liquid cooling Phase Change Material (PCM) method is used. But these air cooling and liquid cooling have some drawbacks like slow cooling effect and the latter has usage of external material, etc. Even phase change material also has low thermal conductivity issue. So to over come these issues a hybrid BTMS is designed in this experimental work. Paraffin as PCM material is used along with liquid cooling. The results showed that PCM coupled with liquid cooling has more effect on thermal conductivity when compared to enhanced PCM. The paraffin has good latent heat storage so it is used for good temperature distribution and liquid cooling is used to significantly reduce the heat from the PCM.

Culantro (Eryngium foetidum) is a spice and a medicinal herb native to Mexico and South America. It is widely used in Asia, South America, Africa and other parts as condiment. It has several medicinal properties like anti-inflammatory and analgesic activities, anti-venom properties, etc. However, its use is mostly seasonal due to lack of preservation techniques. Therefore, this paper presents the study of culantro drying under three drying techniques, viz. continuous, intermittent and partial vacuum. Results showed that moisture diffusivity was 3.11 × 10–09, 1.44 × 10–09 and 8.13 × 10–10 m2/s, respectively, for continuous, intermittent and partial vacuum drying, while the moisture transfer coefficient was between 1.87 × 10–08 and 1.46 × 10–06 m/s. Drying was completed within 4 hours with final moisture content ranging between 1 and 6.27%. The highest effective drying rate was observed for intermittent drying with 16.67% reduced drying time. Also, the Biot number-drying coefficient ( $$Bi - S$$ B i - S ) and Biot number-lag factor ( $$Bi - G$$ B i - G ) analytical models were applied to the drying data for prediction of drying behaviour. There was good agreement between the experimental and predicted values of moisture ratios for continuous drying, intermittent drying and partial vacuum drying with respective R2 values of 0.93, 0.98 and 0.92 for ( $$Bi - S$$ B i - S ) model and 0.95, 0.97 and 0.96 for ( $$Bi - G$$ B i - G ) model.

A two-dimensional numerical investigation on flow past a heated circular cylinder at different confinement has been carried out. The unconfined flow has been simulated with a large blockage ratio 112 (i.e., ratio of the computational domain height to the diameter of the circle). The effects of Reynolds number in the range 0.1 ≤ Re ≤ 200 and blockage ratios of 5, 10, and 112 on various flow and heat transfer characteristics are studied and analyzed in the form of streamline plots, variations of pressure and viscous drag coefficients, Strouhal number, total pressure drop, and surface average Nusselt number. The values of drag coefficients are higher for confined flow compared with unconfined flow. Moreover, at low Reynolds number the frictional drag coefficient is higher than the coefficient of pressure drag. As Reynolds number increases, the pressure drag coefficient increases and observed to be higher than the corresponding frictional drag coefficient. The impact of blockage ratio on heat transfer in between 10 and 112 for constant temperature is comparatively lesser and also the convective heat transfer is enhanced at blockage ratio 5. The percentage increase in pressure drop between the unconfined flow and blocking ratio 5 and 10 are 21.43 and 9.43, respectively.

Sloshing is the motion of liquids subjected to external forces with large free surface deformations. The liquid moves back and forth and rises along the side walls that may impact the roof which in turn generates loads affecting the structural integrity of the container and also the stability of the vehicle carrying it. This phenomenon is observed in launch vehicles, propellant carriers, spacecraft, cargo ships, and storage tankers carrying different types of fluids such as chemicals, water, oil, liquefied gas, and caustic soda. It is essential to determine the sloshing frequencies and hydrodynamic pressure on tank walls so that proper design of tank or container can be made. Recently, the demands for safety of such containers have increased. Different wave conditions in partially filled tanks, uncontrolled loading/unloading processes, structural frequencies, shape and position of the tank, sources of the motions, filling levels inside the tanks, or density of the fluid may cause sloshing. In this paper, sloshing in a cylindrical liquid tank subjected to horizontal excitation is investigated experimentally and numerically. After series of experiments, results obtained for each tank configuration are compared and flow is visualized for the tanks that are filled with different fluids commonly transported in tankers. The results of the study can give a better picture on the effects of fluid viscosity on slosh behavior and provides valuable information for effective tank designs.

Weight of the vehicle plays an important role as it directly affects the fuel efficiency and overall vehicle performance. So, design optimization at the component level is the best approach to achieving the best design with the least mass. A mathematical approach, namely, topology optimization is used in the optimization process to remove the excess portion of the product, keeping in mind the stress concentrations as well as the safety factor. A semi-trailing arm, being a suspension component, requires high strength and durability. The base design of the semi-trailing arm is designed in SolidWorks using the suspension hard points whose kinematic analysis is carried out in the LOTUS Shark suspension analyzer. Static structural analysis of the model is done using ANSYS to determine the excess material in the design. The optimized design was achieved in an iterative process in Altair HyperWorks Optistruct. The optimized design resulted in a 34% reduction of original mass with desired strength. A comparison of design parameters, viz. stress, and total deformation for the base design as well as the optimized design is carried out. In addition, physical tests show an impressive correlation with the prevalidated design.

An experimental study was conducted to investigate the interpulse re-initialization of cavitation bubble clouds in a pulsed focused ultrasound field. 550 kHz waves of peak-negative-pressure amplitude varying from 3 to 5 MPa were used to produce cavitation in water in the presence of a wire target at the focus, whereas high-speed camera visualizations were carried out to capture the bubble cloud dynamics. The influence of pulse duty cycle was assessed, and the associated mechanisms were highlighted showing the response time delay of the cloud to ultrasound of the order of 5 μs. Two regimes of cloud bubble dynamics were observed: for short duty cycle values, the bubble cloud develops only from the wire, which is consistent with a scenario of the cloud completely reset each burst, while for appropriately high duty cycle values, the cavitation nuclei allow a rapid cloud reset despite its extinction between bursts.

The aim of this paper is to study the thermal degradation of waste tires (WT) by thermogravimetric analysis (TGA), for different heating rates, under nitrogen atmosphere (N2). Experiments were carried out at different heating rates to reach 800 °C. Kissinger–Akahira–Sunose (KAS) model was applied to calculate the kinetic parameters. Analyses were performed at the heating rates of 2, 10, 40 and 60 °C/min. The modelling developed here allows for the calculation of the solid temperature at different conversion degrees for different heating rates. Simulation of WT pyrolysis using ATG data showed a good agreement with experimental data for the KAS model. The dependence of the apparent Ea determined using the KAS model on the conversion rate reveals that pyrolysis progresses rather through multi-step kinetics.

This work presents a study of different CO2 compression models. Various CO2 compression options widely used in the industry will be modelled through Aspen plus and energy requirement and heat available will be quantified and compared. An operating costs and capital costs assessment has been first conducted using Aspen Process Economics Analyzer. A heat integration equation for the potential transfer of heat available into electricity for all CO2 compression options has been used, and potential energy-saving and cost-saving have been quantified. The results show that the optimal option has a cost-saving of nearly 4.17 $/t CO2 for the operating costs. This optimal option has also a power requirement of 61,302 kW and has an equipment cost of 0.17$/t CO2.

The paper focuses on the flow and heat transfer flow between two concentric cylinders. It investigates the Taylor-Couette system with a rotating inner cylinder and an imposed radial temperature gradient. Taylor number, aspect ratio, and Grashof number were discussed to determine the temperature gradient in the Taylor-Couette flow. In the mixed-convection region, a distorted form of the Taylor cells appeared. Hence, the choice of different aspect ratios and Grashof to determine the maximum heat transports mechanism at a fixed Taylor number. These results in a particularly compact and simple formulation to propose the axisymmetric energy equation in the cylindrical coordinate system. It is rearranged in the Cartesian coordinate system with extra terms. Simulations of several complex buoyancy-driven thermal flows and including swilling effects in cylindrical geometries using the axisymmetric cascaded LB schemes show good agreement with prior benchmark results for the structures of the velocity and thermal fields as well as the heat transfer rates given in terms of the Nusselt numbers. Furthermore, the governing equations were solved by the lattice Boltzmann method (LBM), allowing us to understand the mechanisms of heat transport.

A Life Cycle Assessment (LCA) technique allows to evaluate the environmental impacts of a system and to calculate the carbon footprint. In this study, this technique is applied to the AUDI climatic wind tunnel of height 16.5 m, length 35 m, a nozzle section of 6 m2, and a maximum wind speed of 300 km/h. The method IMPACT 2002 + is chosen to analyze the impact distribution in resource consumption and ecosystem quality. Life cycle emissions in particular life cycle CO2 and global warming coefficient of the climatic wind tunnel are assessed and compared with a scenario where renewable source of energy that could run this wind tunnel during in its operational phase. By considering carbon footprints from the whole plant setup, the plant recycle and the entire process of energy flow (from testing, usage, and maintenance), the LCA model is built. Highest source of the global warming emissions related to CO2 gas are generated by the type of electricity consumed in the plant during its operational phase.