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Online teaching–learning methods have been followed by world-class universities for more than a decade to cater to the needs of students who stay far away from universities/colleges. But during the COVID-19 pandemic period, online teaching–learning helped almost all universities, colleges, and affiliated students. An attempt is made to find the effectiveness of online teaching–learning methods for university and college students by conducting an online survey. A questionnaire has been specially designed and deployed among university and college students. About 450 students from various universities, engineering colleges, medical colleges in South India have taken part in the survey and submitted responses. It was found that the following methods promote effective online learning: animations, digital collaborations with peers, video lectures delivered by faculty handling the subject, online quiz having multiple-choice questions, availability of student version software, a conducive environment at home, interactions by the faculty during lectures and online materials provided by the faculty. Moreover, online classes are more effective because they provide PPTs in front of every student, lectures are heard by all students at the sound level of their choice, and walking/travel to reach classes is eliminated.

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Binder provides structural integrity by holding all ingredients in the composition of a brake friction material. The modified binders have played a major role in improving the frictional performance and thermal resistance of the friction material. The present research work evaluates the influence of secondary binders (Nitrile Butadiene rubber (NBR) and Styrene Butadiene rubber (SBR)) on the tribological performance of the friction material using a full-scale inertia brake dynamometer as per JASO C406 standard. Three brake pads were developed by varying the type and composition of secondary rubber binder (5%NBR, 5%SBR and 2.5%NBR + 2.5%SBR) with rest of the ingredients kept unaltered. It was found that the quantity of SBR rubber powder present as secondary binder improved dry and wet recovery. Friction coefficient (μ) exhibited better stability during the fade with the inclusion of both the rubber powders. The friction material with the inclusion of both the NBR and SBR rubber powders exhibited overall better performance than compared to the inclusion of only one secondary binder rubber in the composition. The worn-out surface of the developed friction materials and the counter discs were characterised using FESEM.

This paper gives a comprehensive review of advanced cooling schemes and their applications to the permanent magnet synchronous motors (PMSMs), as well as investigating the electrical motor’s topologies its thermal design issues, materials and performances. Particularly, the electromagnetic and electric performances, machine sizing, together with the structural design, are given. In addition, the work addresses the motor’s material design and properties along with its insulation performance, which is the main goal of optimization. Mainly, thermal mapping with analysis is provided according to the different cooling methods, including air-cooling, water-cooling, oil-cooling, heat-pipe-cooling, potting silicon gelatin cooling, and as well as cooling strategies for tubes and microchannels. The most common special features and demands of the PMSMs are described in the appearance of the motor’s failures caused by uncontrolled temperature rise. In addition, heat sources and energy losses, including copper loss, core loss versus motor speed, and output power, are analyzed. The review of the proposed cooling methods that will achieve the required heat transfer of the PMSM is presented with numerical simulations and measurements data. A review of numerical methods and results, including the finite element methods (FEM), such as the Ansys CFD software, to obtain a high-accuracy thermal mapping model of the PMSM system is given. The revived methods and design requirements due to PMSM temperature profile and cooling flow at different rotor speeds and torque loads are investigated. Finally, the motor design recommendations, including the newly developed cooling solutions, which enable it to effectively redistribute the temperature and heat transfer, increasing the efficiency of the PMSM machine, are laid out.

The electric motor is the mechanism that transforms electrical energy into mechanical energy. Nowadays, electric motors are the cause of a considerable share of the use of electricity and therefore of the energy consumptions (70% in the industrial sector and 25-30% in the tertiary sector). Faced with ever-increasing energy demand and with a view to adhering to the all-over-the world imperative of adopting measures to reduce energy consumption in all the involved sectors, the use of efficiency enhanced electric motors is required. Generally, the efficiency of an electric motor depends on the type of motor, the size of the motor, the utilization factor, but also on the quality and quantity of the materials employed. Therefore, from all these aspects the need of using energy and costefficient components for developing electric motors arises. This review paper aims to draw a general framework on the methods of increasing efficiency and of reducing weight of the electric motors.

The education sector is witnessing a paradigm shift with the rapid and ongoing technological advancements. The online, offline, and blended modes of learning continue to evolve with time. The purpose of this survey is to collect students’ responses to understand their perspectives on the different modes of learning. The advantages, challenges, and requirements for conducting classes through online, offline, and blended learning methods are discussed. A questionnaire was designed, and a survey was conducted among undergraduate engineering students. The questions are carefully planned to understand the choice of students while selecting different modes of learning, various activities and tools, and the reasons for their preferences. 654 students took part in the survey and shared their feedback. The advantages and disadvantages of online and offline learning are presented. A chi-square test was conducted, and the association between the two questions is shown to be significant. Suggestions for enhancing teaching and learning based on the findings of the survey help faculty members to plan the teaching methodology to suit the requirements of students.