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This paper aims to present an analytical investigation of energy and exergy performance on a solar flat plate collector (SFPC) with Cu-CuO/water hybrid nanofluid, Cu/water and CuO/water nanofluids as collector running fluids.

Heat transfer characteristics, pressure drop and energy and exergy efficiencies of SFPC working on these nanofluids are investigated and compared. In this study, a comparison is made by varying the mass flow rates and nanoparticle volume concentration. Thermophysical properties of hybrid nanofluids are estimated using distinctive correlations available in the open literature. Then, the influence of these properties on energy and exergy efficiencies of SFPC is discussed in detail.

Energy analysis reveals that by introducing the hybrid nanoparticles in water, the thermal conductivity of the working fluid is enhanced by 17.52 per cent and that of the individual constituents is enhanced by 15.72 and 15.35 per cent for Cu/water and CuO/water nanofluids, respectively. This resulted in 2.16 per cent improvement in useful heat gain for hybrid nanofluid and 1.03 and 0.91 per cent improvement in heat gain for Cu/water and CuO/water nanofluids, respectively. In line with the above, the collector efficiency increased by 2.175 per cent for the hybrid nanofluid and 0.93 and 1.05 per cent enhancement for Cu/water and CuO/water nanofluids, respectively. Exergy analysis elucidates that by using the hybrid nanofluid, exergy efficiency is increased by 2.59 per cent, whereas it is 2.32 and 2.18 per cent enhancement for Cu/water and CuO/water nanofluids, respectively. Entropy generation is reduced by 3.31, 2.35 and 2.96 per cent for Cu-CuO/water, Cu/water and CuO/water nanofluids, respectively, as compared to water.

However, this is associated with a penalty of increment in pressure drop of 2.92, 3.09 and 2.74 per cent for Cu-CuO/water, Cu/water and CuO/water nanofluids, respectively, compared with water.

It is clear from the analysis that Cu-CuO/water hybrid nanofluids possess notable increment in both energy and exergy efficiencies to use them in SFPCs.

This paper aims to present the effects of varying different operating parameters such as Start of Injection (9 to 21 deg bTDC), compression ratio (16 to 12.5), fuel injection pressure (400 to 1,400 bar) and exhaust gas recirculation (0 to 25 per cent) on the performance and emissions of the engine for constant engine speed of 1,600 rpm.

Simulation results were validated with experimental data available in the literature for baseline configuration. The effect of each parameter on the performance characteristics such as pressure and temperature, emission characteristics such as NO_x and soot are presented and discussed. Optimization has been carried out based on the regression equations developed from the simulation results to obtain the optimum set of the parameters to achieve the desired performance and emissions. Numerical simulations have been performed for the optimized set and compared with the reference engine.

Results of optimization showed that there was a simultaneous reduction in NO_x and soot while maintaining the same level of performance as that of the baseline case.

Based on the present work, it can be said that lesser emissions are achieved in terms of NO_x and soot while maintaining the same performance in terms of peak pressure.

Electronic devices aid communication during new communication phases and the scope of cognitive radio networks has changed communication paradigms through efficient use of spectrums. The communication prototype of cognitive radio networks defines user roles as primary user and secondary user in the context of the spectrum allocation and use. The users who have licensed authority of the spectrum are denoted as primary users, while other eligible users who access the corresponding spectrum are secondary users.

The multiple factors of transmission service quality can have a negative influence due to improper scheduling of spectrum bands between primary users and secondary users. There are considerable contributions in contemporary literature concerning spectrum band scheduling under spectrum sensing. However, the majority of the scheduling models are intended to manage a limited number of transmission service quality factors. Moreover, these service quality factors are functional and derived algorithmically from the current corresponding spectrum. However, there is evidence of credible performance deficiency regarding contemporary spectrum sensing methods

This article intends to portray a fuzzy guided integrated factors-based spectrum band sharing within the spectrum used by secondary users. This study attempts to explain the significance of this proposal compared to other contemporary models.

This article intends to portray a fuzzy guided integrated factors-based spectrum band sharing within the spectrum used by secondary users. This study attempts to explain the significance of this proposal compared to other contemporary models.

This paper aims to investigate two control mechanisms on the two parameters, namely, spindle speed and tool pin position, while performing friction stir welding (FSW) for aluminium metal matrix composites (Al-MMC) using the concept of system identification.

FSW is a feasible choice for joining of Al-MMC over the fusion welding due to the formation of the narrow heat-affected zone and minimizing the formation of intermetallic compounds at weld interface. The goal in FSW is to generate enough thermal energy by friction between the workpiece and rotating tool. Heat energy is generated due to mechanical interaction because of the difference in velocity between the workpiece and rotating tool. The generated heat is proportional to the tool pin position and the spindle speed. In the present work, a Smith Predictor Control scheme and adaptive control scheme are developed during joining of Al6061/SiC/B4C Al-MMC by FSW. Adaptive controller is developed to control the tool pin position while Smith Predictor control is developed to control the spindle speed. Initially, the Al-MMC plates are prepared at five combinations of SiC and B4C reinforcements and welded at three level parameter settings followed by tensile testing. The experimental data are used in estimating the plant transfer function model using system identification. The control schemes are then developed for the estimated plant model and the same are validated using a standard PID controller. In both the control schemes, PID controller results in a sluggish response. Experimental validations are performed for the developed control schemes followed by microscopic studies of the weldments.

In both the control schemes, PID controller results in a sluggish response. Experimental validations are performed for the developed control schemes followed by microscopic studies of the weldments.

Results from the study concluded that the developed MRAC and Smith predictor scheme effectively controlled the vibrations and spindle speed effectively.

It is observed that the scanning electron microscopy micrographs of the Al-MMC’s welded using developed control schemes resulted in good boding with homogenous distribution of reinforcement particles.

Gender studies have become an important area of study in recent times. It is being accorded an important place in the curriculum, both at the school and university levels. The many misconceptions that exist regarding the term “gender” need to be addressed, the most common being that gender has solely to do with women and their issues only. The basic important idea that gender studies is inclusive of female, male, and third gender and their issues isn't understood nor made aware to many. The role of education has become all the more important so that we are able to break the prevalent societal stereotypes and address the existing gender inequality. This chapter attempts to present various feminist theories that have contributed to the understanding of gender. The important role of the schools and in particular the textbooks in socializing and building learners' understanding of the sociopolitical contexts cannot be negated. Hence, the chapter will conclude by analyzing how gender content and issues are experienced and get represented in the school curriculum and the textbooks. Many researchers have emphasized the need for gender inclusion to achieve holistic and sustainable development goals. This is important because only with the achievement of social equality can we work toward economic equality.

The purpose of this study is to present a comprehensive review of the fundamental concepts and terminologies pertaining to different types of aluminium metal matrix composites, their joining techniques and challenges, friction stir welding (FSW) process, post-welding characterizations and basic control theory of FSW, followed by the discussions on the research reports in these areas.

Joining of aluminium metal matrix composites (Al-MMC) poses many challenges. These materials have their demanding applications in versatile domains, and hence it is essential to understand their weldability and material characteristics. FSW is a feasible choice for joining of Al-MMC over the fusion welding because of the formation of narrow heat affected zone and minimizing the formation of intermetallic compounds at weld interface. The goal in FSW is to generate enough thermal energy by friction between the workpiece and rotating tool. Heat energy is generated by mechanical interaction because of the difference in velocity between the workpiece and rotating tool. In the present work, a detailed survey is done on the above topics and an organised conceptual context is presented. A complete discussion on significance of FSW process parameters, control schemes, parameter optimization and weld quality monitoring are presented, along with the analysis on relation between the interdependent parameters.

Results from the study present the research gaps in the FSW studies for joining of the aluminium-based metal matrix composites, and they highlight further scope of studies pertaining to this domain.

It is observed that the survey done on FSW of Al-MMCs and their control theory give an insight into the fundamental concepts pertaining to this research area to enhance interdisciplinary technology exploration.

Scatter in the outcome of repeated experiments is unavoidable due to measurement errors in addition to the non-linear nature of the output responses with unknown influential input parameters. It is a standard practice to select an orthogonal array in the Taguchi approach for tracing optimum input parameters by conducting a few number of experiments and confirm them through additional experimentation (if necessary). The purpose of this paper is to present a simple methodology and its validation with existing test results in finding the expected range of the output response by suggesting modifications in the Taguchi method.

The modified Taguchi approach is proposed to find the optimum process parameters and the expected range of the output response.

This paper presents a simple methodology and its validation with existing test results in finding the expected range of the output response by suggesting modifications in the Taguchi method.

Adequacy of this methodology should be examined by considering the test data on different materials and structures.

The introduction of Chauvenet’s criterion and opposing the signal-to-noise ratio transformation on repeated experiments of each test run will provide fruitful results and less computation burden.

The effects of material parameters and processing conditions on the resistance drop by high voltage discharge in PVC – graphite thick film resistors are studied in this paper. The resistance drop increased upon an increase in graphite aggregate size, which is a function of material parameters and processing conditions. The resistance drop has been attributed to the dielectrophoretic motion of graphite particles in PVC by the application of high voltages to polymer thick film resistors.

Entrepreneurship.

The case can be taught for students at the Master's level and research scholars in management education.

Univexcellence was an idea conceived by Surbhi from her science project in 1997 when she was studying at Kendriya Vidyalaya, Jaipur, India. The science project model was based on the theme “World is a classroom, room is university”. It was shown that the world would be converted into a room, and the room itself would become a University through satellite communication. Surbhi decided to become a computer engineer and learn about it herself so as to become self-dependent as a business woman. Keeping this in mind, she completed a computer engineering course. A strong sense of efficacy enhances human accomplishment and personal well-being in many ways. Surbhi has proved it in her case.

The case describes challenges and setbacks faced by a woman entrepreneur and through her self-confidence and persistence, illustrate show she solved them to the benefit of her business.

Teaching notes are available for educators only. Please contact your library to gain login details or e-mail support@emeraldinsight.com to request teaching notes.

The study investigates the impact of various factors that affect the business performance of micro-level women entrepreneurs in the UAE and India.

A conceptual model including the factors that impact the performance of micro-level women entrepreneurs is proposed. The proposed model was validated with data collected through a structured questionnaire based on a cross-sectional survey conducted in the UAE and India. The collected data was analyzed using the structural equations modeling approach.

Findings revealed that factors such as competitive aggressiveness, incubation, innovativeness, market orientation and risk-taking propensity have a positive impact on business performance and growth in both countries. Factors like training, learning and finance orientation did not affect business performance.

Gender plays an essential and influential role in developing countries with regard to entrepreneurship. This research attempts to uncover the often-neglected area of women entrepreneurship.