Explore the vast range of titles available.

A plug-in hybrid electric vehicles (PHEV) charger adapter consists of an AC/DC power factor correction (PFC) circuit accompanied by a full-bridge isolated DC/DC converter. This paper introduces an efficient two-stage charger topology with an improved PFC rectifier as front-end and a high-frequency zero voltage switching (ZVS). Current switching (ZCS) DC/DC converter is the second part. The front-end converter is chosen as bridgeless interleaved (BLIL) boost converter, as it provides the advantages like lessened input current ripple, capacitor voltage ripple, and electromagnetic interference. Resettable integrator (RI) control technique is employed for PFC and DC voltage regulation. The controller achieves nonlinear switching converter control and makes it more resilient with the faster transient response and input noise rejection. The second stage incorporates a resonant circuit, which helps in achieving ZVS/ZCS for inverter switches and rectifier diodes. PI controller with phase shift modulator is used for second-stage converter. It improves the overall efficacy of the charger by lowering the switching losses, lowering the voltage stress on the power semiconductor devices, and reversing recovery losses of the diodes. The simulations and experimental results infer that the overall charging efficiency increases to 96.5%, which is 3% higher than the conventional two-stage approach using the interleaved converter.

Electricity can be provided to small-scale communities like commercial areas and villages through microgrid, one of the small-scale, advanced, and independent electricity systems out of the grid. Microgrid is an appropriate choice for specific purposes reducing emission and generation cost and increasing efficiency, reliability, and the utilization of renewable energy sources. The main objective of this paper is to elucidate the combined economic emission dispatch CEED problem in the microgrid to attain optimal generation cost. A combined cost optimization approach is examined to minimize operational cost and emission levels while satisfying the load demand of the microgrid. With this background, the authors proposed a novel improved mayfly algorithm incorporating Levy flight to resolve the combined economic emission dispatch problem encountered in microgrids. The islanded mode microgrid test system considered in this study comprises thermal power, solar-powered, and wind power generating units. The simulation results were considered for 24 hours with varying power demands. The minimization of total cost and emission is attained for four different scenarios. Optimization results obtained for all scenarios using IMA give a comparatively better reduction in system cost than MA and other optimization algorithms considered revealing the efficacy of IMA taken for comparison with the same data. The proposed IMA algorithm can solve the CEED problem in a grid-connected microgrid.

This study explores the durability of green cementitious material of geopolymer concrete. Geopolymer concrete is produced from the polycondensation reaction of aluminosilicate materials (fly ash, Ground Granulated Blast furnace Slag (GGBS)) with alkaline activator solutions. Geopolymer concrete has excellent mechanical properties and its production requires low energy and results in low levels of CO2 emission. Due to the high demand for river sand, manufactured sand is used as a replacement material in geopolymer concrete under ambient curing conditions. In this study, the durability of G30 grade geopolymer concrete has been investigated using tests acid resistance, water absorption, sulphate resistance, Rapid Chloride Penetration Test (RCPT), and rate of absorption (Sorptivity) test. The sulphuric acid, sodium sulphate, and water absorption tests were carried out at 28 days, 56 days, and 90 days for both the geopolymer and the conventional concrete. The reduction percentage in water absorption and compressive strength loss was found to be better in geopolymer concrete than in conventional concrete. Geopolymer concrete’s chloride penetrability and rate of absorption were analogous to conventional concrete. Regression analysis for geopolymer and conventional concretes in the rate of absorption test showed a good relationship between absorption and the square root of time.

Electricity is a crucial part of our everyday lives. A limited number of resources can be utilized to generate power; hence, one must save these resources or electricity for future utilization. This is only possible by using energy most efficiently. For sustainable development and energy conservation, energy auditing plays an indispensable role. The energy audit is an extensive study that helps to identify energy use among different services and provides opportunities for energy conservation. The literature showed various energy audits conducted at various locations with its analysis. Few were shown that the appliances are responsible for high energy consumption, and few talked about the cost analysis with energy-saving methodologies. This work is proposed to combine the integration of renewable energy sources in a building and the cost-saving due to energy-efficient appliances. This paper tries to observe, infer, and analyze the patterns of energy usage of a residential complex and various measures to reduce energy consumption and cost-saving. A case study is included to analyze the reduction in consumption of energy per unit to make the building energy efficient. A feasibility study is executed to observe the increments in costs. Calculations for auditing will reduce the building’s carbon footprint and benefit residents in the form of cost savings in the long run.

PurposeThe current and on-going coronavirus (COVID-19) has disrupted many human lives all over the world and seems very difficult to confront this global crisis as the infection is transmitted by physical contact. As no vaccine or medical treatment made available till date, the only solution is to detect the COVID-19 cases, block the transmission, isolate the infected and protect the susceptible population. In this scenario, the pervasive computing becomes essential, as it is environment-centric and data acquisition via smart devices provides better way for analysing diseases with various parameters.Design/methodology/approachFor data collection, Infrared Thermometer, Hikvision’s Thermographic Camera and Acoustic device are deployed. Data-imputation is carried out by principal component analysis. A mathematical model susceptible, infected and recovered (SIR) is implemented for classifying COVID-19 cases. The recurrent neural network (RNN) with long-term short memory is enacted to predict the COVID-19 disease.FindingsMachine learning models are very efficient in predicting diseases. In the proposed research work, besides contribution of smart devices, Artificial Intelligence detector is deployed to reduce false alarms. A mathematical model SIR is integrated with machine learning techniques for better classification. Implementation of RNN with Long Short Term Memory (LSTM) model furnishes better prediction holding the previous history.Originality/valueThe proposed research collected COVID −19 data using three types of sensors for temperature sensing and detecting the respiratory rate. After pre-processing, 300 instances are taken for experimental results considering the demographic features: Sex, Patient Age, Temperature, Finding and Clinical Trials. Classification is performed using SIR mode and finally predicted 188 confirmed cases using RNN with LSTM model.

This study inspects the viability of engaging the discarded paper wastes in concrete by varying the volume proportions from 0%–20% with each 5% increment in replacement of the weight of cement. A physiomechanical study was conducted, and the results were presented. A glass fiber reinforced rectangular slab with a longer span (ly) to shorter span (lx) ratio of (ly: lx) 1.16 was cast with optimum replacement of waste-paper mass and compared the force-deformation characteristics with the conventional concrete slab without waste paper. The optimum percentage of discarded papers for the replacement of cement is 5%. Also, the results imply that the compressive strength at the age of 28 days is 30% improved for the optimum replacement. Based on the outcomes of the investigation, it can be inferred that the compressive strength gets progressively reduced if the volume of the discarded paper gets increases. The incorporation of glass fibers improves the split and flexural strength of the concrete specimens considerably. The ultimate load-carrying capacity of the glass fiber reinforced waste paper incorporated concrete slab measured 42% lower than that of the conventional slab. However, development of the new type of concrete incorporating waste papers is the new trend in ensuring the sustainability of construction materials.

This optimization investigation focused on the reinforced metal matrix composite of aluminium alloy. Novel of this work is to fabricate the AA6066 composite with HSS and Cu, continually conduct machining tests, and evaluate the tool wear, surface roughness, and thrust force of the stir-casted specimens. The aluminium composite has 90 percentage of AA6066 alloy reinforcement with six percentage of high-speed steel and four percentage of copper alloy made by the casting method. The fabricated composites’ turning parameters were optimized through the Taguchi method. The turning operation can be done with the help of the normal lathe with the CBN insert tool. The operation parameters such as feed, depth of cut, and steam pressure of the cutting fluid were considered with three different equal intervals in each parameter. In this investigation, the L9 orthogonal array method is used to identify the optimum values of the turning parameters among the considered machining parameters concerning the response such as wear on the turning tool and thrust forces created on machining. The outcome based on the parameters was identified and mentioned as the rank order for individual and combination of all responses with different conditions. Then, the separate and combined optimized input parameters were provided as the conclusion.

In the automotive and aerospace industry, abrasive products lodge the major portion of the machining applications. Among that, the coated abrasive disc is used for a finishing application. Once the disc is fully consumed, the disc is unused and considered waste. The present work focuses on removing phenol-formaldehyde resin coating, and the fiber backing is reused for the same coated abrasive disc production application as flexible fiber backing. A sandblasting technique removes phenol-formaldehyde resin coating and embedded abrasive grains. During the fiber backing recovery process, the experimental parameters such as abrasive pressure, abrasive type, abrasive size, and orientation of the disc are varied to find out the optimal surface roughness value for reusing the produced coated abrasive discs. The results highlight that the recovered backing has an abrasive size of 120 mesh pressure of 0.20 MPa, an abrasive type of garnet, and a standoff distance of 1 mm. Surface features such as surface roughness and micrographs of the eroded surface are analyzed. Finally, the recovered backing was reused in the coated abrasive disc production, and the performance of the recovered disc was compared with the standard discs. The recovered fiber backing disc product was similar to a standard fresh disc.

The ideology of ensuring energy-efficient design and construction of buildings by providing minimum requirements is the core objective of this work. Energy audit was conducted to improve the design of the building with incremental requirements to further enhance the energy efficiency. The Energy Conservation Building Code (ECBC) has been modified extensively over the years, starting from its initial deployment in the year 2011 to its latest modifications in the year 2019. The energy conservation standards in ECBC apply to building envelope, heating ventilation, air conditioning, lighting, service water heating, and electric power distribution. It should also be ensured that all-electric systems, transformers, energy-efficient motors, and diesel generators must meet the regulated set of mandatory requirements. From among the various software types that have been approved for ECBC design and application, this study has employed Energy Plus software to simulate the design based on the given input and the selected location. The location that has been chosen for this study was Bhubaneshwar, India. All necessary details ranging from latitude, longitude, weather, time zone, elevation, building area, lighting, heating, cooling, and much more have been covered in the simulation. Utilizing ECBC regulated standards for an energy-efficient building design has resulted in an increase in the energy savings by 27.4%, and thus, the building qualifies to be regarded as an ECBC compliant building.

Currently, numerous studies have shown that carbon nanofibres have mechanical properties that are replaced by other widely used fibres. The high tensile strength of the carbon fibres makes them ideal to use in polymer matrix composites. The high-strength fibres can be used in short form in a composite and mass-produced to meet the high demands of automotive applications. These composites are capable of addressing the strength requirement of nonstructural and structural components of the automotive industry. Due to these composite lightweight and high-strength weight ratios, the applications can be widely varying. The research for these materials is a never-ending process, as researchers and design engineers are yet to tap its full potential. This study fabricated phenolic resin with different wt% of carbon nanofibre (CNF). The percentage of the CNF as a filler material is varied from 1 to 4 wt%. Mechanical properties such as hardness, tensile strength, and XRD were investigated. Phenolic resin with 4 wt% of carbon nanofibre (CNF) exhibits maximum tensile strength and hardness of 43.8 MPa and 37.8 HV.