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1 – 10 of 337Sanjay Mohan Sharma and Ankush Anand
This paper aims to investigate the effect of CaF2 (calcium fluoride) addition as a solid lubricant on the friction and wear behaviour of sintered Fe-Cu-C materials under different…
Abstract
Purpose
This paper aims to investigate the effect of CaF2 (calcium fluoride) addition as a solid lubricant on the friction and wear behaviour of sintered Fe-Cu-C materials under different loads.
Design/methodology/approach
In this study, the effects of CaF2 added in varying weight percentages on the friction-wear properties of Fe-2Cu-0.8C alloys are investigated. Five Fe-2Cu-0.8C-based compositions comprising CaF2 in 0, 3, 6, 9 and 12 Wt.% were prepared using the single-stage compaction and sintering technique. Friction coefficient, wear loss, hardness and compressive strength of the specimens were measured. The worn-out surfaces were analysed using a scanning electron microscope. Friction and wear tests were carried out on pin-on-disc machine under dry sliding conditions at room temperature.
Findings
The alloy with 3 Wt.% CaF2 was found to be useful in improving wear and friction properties, whereas higher contents of CaF2 resulted in increased wear and friction. Apart from enhanced tribological properties, a slight decrease in the compressive strength was also observed in the 3-Wt.%-CaF2-added sample. Adhesion and abrasion were the prominent wear types observed during this study.
Originality/value
A new self-lubricating composite is developed where CaF2 is used as a solid lubricant in a Fe-Cu-C-based matrix. CaF2, being a high-temperature lubricant, is tried and tested for friction and wear at room temperature, and the results show that the addition of CaF2 in Fe-Cu-C improved its friction and wear properties. Thus, the developed material can be used for antifriction applications.
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Deepak Byotra and Sanjay Sharma
This study aims to understand how the texture shape, number of textures and addition of nanoparticle additives in lubricants impact the dynamic characteristics of journal bearing…
Abstract
Purpose
This study aims to understand how the texture shape, number of textures and addition of nanoparticle additives in lubricants impact the dynamic characteristics of journal bearing by comparing six different texture shapes like triangle, chevron, arc, circle, rectangle and elliptical applied in pressure-increasing region under various geometrical and operating conditions.
Design/methodology/approach
The finite element method approach has been employed to solve governing Reynold’s equation, assuming iso-viscous Newtonian fluid, for computation of performance parameters like stiffness and damping coefficient, threshold speed, etc. By using a regression model, the impact of adding nanoparticles Al2O3 and CuO to the base lubricant on viscosity variation is calculated for selected temperature ranges and weight fractions of nanoparticles.
Findings
The arc-shaped texture with an area density of 28.27%, eccentricity ratio of 0.2 and texture depth of 0.6 exhibited 35.22% higher direct stiffness and 41.4% higher damping coefficient compared to the lowest value in the circle-shaped texture. Increasing the number of arc-shaped textures on the bearing surface with low area density led to declining stiffness and damping parameters. However, with nanoparticle additives, the arc-shaped texture further showed 10.75% and 8.11% improvement in stiffness and 9.99% and 4.87% enhancement in damping coefficient for Al2O3 and CuO, respectively, at 90 °C temperature and 0.5% weight fraction.
Originality/value
By understanding the influence of texture shapes on the dynamic characteristics, engineers can design bearings that exhibit improved stability and enhance overall performance.
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Deepak Byotra and Sanjay Sharma
This study aims to find the dynamic performance parameters of the journal bearing with micro geometries patterning the arc (crescent) shape textures provided in three specific…
Abstract
Purpose
This study aims to find the dynamic performance parameters of the journal bearing with micro geometries patterning the arc (crescent) shape textures provided in three specific regions of the journal bearing: the full, the second half and the increasing pressure region. The dynamic behavior of textured journal bearings has been analyzed by computing dynamic parameters and linear and non-linear trajectories.
Design/methodology/approach
The lubricant flows between the bearing and journal surface are governed by Reynold’s equation, which has been solved by finite the element method. The dynamic performance parameters such as stiffness, damping, threshold speed, critical mass and whirl frequency ratio are examined under various operating conditions by considering various ranges of eccentricity ratios and texture depths. Linear and non-linear equations of motion have been solved with Ranga–Kutta method to get journal motion trajectories. Also, the impact of adding aluminum oxide and copper oxide nanoparticles to the base lubricant in combination with arc-shaped textures is analyzed to further see any enhancement in the performance parameters.
Findings
The findings demonstrated that direct stiffness and damping parameters increased to their maximum level with six textures in the pressure-increasing region when compared with the untextured surface. Also, nanoparticle additives showed improvements above the highest value attained with no inclusion of additives in the same region or quantity of textures.
Originality/value
Engineers may design bearings with improved stability and overall performance if they understand how texture form impacts dynamic properties.
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Deepak Byotra and Sanjay Sharma
This study aims to investigate the performance improvement of journal bearing by applying the arc-shaped textures on various regions of bearing expressly full, second half and…
Abstract
Purpose
This study aims to investigate the performance improvement of journal bearing by applying the arc-shaped textures on various regions of bearing expressly full, second half and pressure increasing regions operating with and without nanoparticles in the lubricant.
Design/methodology/approach
The Reynolds equation is solved numerically by using the finite element method to obtain static performance parameters such as load-carrying capacity (LCC) and coefficient of friction (COF), which are then compared with untextured bearing at eccentricity ratios of 0.2 to 0.8. Aluminum oxide (Al2O3) and copper oxide (CuO) nanoparticles additives are used, and viscosity variation due to the addition of additives in the base lubricant is computed for considering the range of temperatures 50 to 90°C at a weight fraction of 0.1 to 0.5% by using an experimentally validated regression model.
Findings
The results indicate that the maximum LCC and the lower COF are found in the pressure-increasing region. A maximum increase of 34.42% is observed in the pressure-increasing region without nanoparticles, and furthermore, with the addition of Al2O3 and CuO nanoparticles in lubricants in the same region, the LCC increased to 21 and 24%, respectively.
Originality/value
Designers should use optimal parameters from the present work to achieve high bearing performance.
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Prabhat Kumar Rai, Dinesh Rout, D. Satish Kumar, Sanjay Sharma and G. Balachandran
The purpose of the present study is to simulate the industrial hot-dip process of Zn-2.5Wt.%Mg-3 Wt.%Al and Zn-2.5 Wt.%Mg-9 Wt.%Al-0.15 Wt.%Si coatings and to study the effect of…
Abstract
Purpose
The purpose of the present study is to simulate the industrial hot-dip process of Zn-2.5Wt.%Mg-3 Wt.%Al and Zn-2.5 Wt.%Mg-9 Wt.%Al-0.15 Wt.%Si coatings and to study the effect of low and high Al variation on their microstructure, microhardness, adhesion and corrosion behaviour.
Design/methodology/approach
The hot-dip Zn-2.5 Mg-xAl coating simulation on steel substrate was carried out using a hot-dip process simulator. The microstructure of the coatings was characterized using a scanning electron microscope, energy dispersive spectroscopy and X-ray diffraction. The corrosion behaviour of the coatings was studied using a salt spray test in 5% NaCl solution as well as dynamic polarization in 3.5% NaCl solution.
Findings
Microhardness of the developed Zn-2.5 Mg-xAl coatings has been found to be approximately two times higher than that of the conventional galvanized coating. Zn-2.5 Mg-3Al coating has exhibited two times higher corrosion resistance as compared to that of Zn-2.5 Mg-9Al-0.15Si coating because of formation of more homogeneous and defect-free microstructure of the former. The MgZn2 phase has undergone preferential dissolution and provided Mg2+ ions to form a protective film.
Originality/value
The relative corrosion resistance of the two Zn–Al–Mg coatings with different Al content has been studied. The defect formed because of higher Al addition in the coating has been detected, and its effect on corrosion behaviour has been analysed.
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The present paper aims to draw an attention towards the inclusion of forecast related costs. Its main purpose is to initiate a new line of research/practice including the…
Abstract
Purpose
The present paper aims to draw an attention towards the inclusion of forecast related costs. Its main purpose is to initiate a new line of research/practice including the forecasting expenditure.
Design/methodology/approach
After a relevant review of supply chain/procurement/production planning related literature, it has been observed that the existing work lacks an explicit inclusion of the cost concerned with forecast. The increased cost of forecasting is expected to enhance the forecasting accuracy. At a higher level, product family is considered for the analysis. However, a basic unit of analysis is always a single item production/procurement situation. Therefore, this situation has been discussed analytically with the use of the fundamental equations and an explicit inclusion of forecasting cost for the first time in the relevant literature. Numerous practical applications have been discussed at strategic and operational level. A framework is also presented for future research in this area.
Findings
A specific contribution of the present paper is an approach towards a unique index for relative forecasting expenditure. The suggested index will be useful for comparison purpose. Also, it can be used as a benchmark that can be improved in future.
Practical implications
The case is explained when cycle time is invariant after discussing the other potential applications. Usefulness of the proposed methodology and the index is discussed for the business organizations operating independently or in the supply chains.
Originality/value
On the basis of the forecast, a production or procurement plan is generated in many of the industrial or business situations. In the context of supply chain/production/inventory management, focus is more on demand forecasting techniques or generation of the forecasts in the existing literature. However, the increased costs concerning forecasts are expected to provide more accurate prediction. Therefore, the originality lies in an inclusion of forecast related costs.
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Sanjay Sharma and Rekha Sharma
India is edging China to become the most populous country by 2028. More than 60 per cent of the current population of India is between 15 and 59 years of age, whereas…
Abstract
Purpose
India is edging China to become the most populous country by 2028. More than 60 per cent of the current population of India is between 15 and 59 years of age, whereas domestically, its relatively youthful profile is seen as the biggest challenge for the government, as India is the largest employable manpower base globally. In the past two decades, the rate of population growth in India has reduced, but the skilled labor force is expected to grow almost 2 per cent annually for the next couple of years. Historically, the Indian economy has been mainly agriculturally based, but, with urbanization, the labor is drifting toward service sectors, and people are increasingly looking to develop their skills in sectors such as hotels, restaurants, airlines, retail and health care. To sustain economic growth, there is an urgent need to develop vocational training programs that address current needs. In spite of all the favorable numbers, the question that must be answered by employers and policymakers remains: Is the available labor being skilled appropriately to be employable? The mushrooming of educational and training institutes in India has imparted professional skills to youth, but industry leaders tend to talk about the unavailability of skilled labor, especially in the culinary skills arena. In a country like India, the labor market tends to alternate between the availability and shortage of skilled labor, and so it seems ironic that on the one hand, there is a shortage of staff and at the same time graduates from various colleges and professional institutes remain unemployed; the reason could be lack of employability skills, especially culinary skills. Given this, the hospitality and tourism industry has emerged as the main driver of the service sector in India; it contributes 6.23 per cent to National GDP and 8.78 per cent of the total employment in India, contributing to significant economic growth. In this context, it is imperative for the government to take appropriate steps in devising strategies to address the problem and also secure successful implementation. This paper aims to analyze the Skill India initiative for the hospitality sector and compare it with the realities on the ground, with particular reference to culinary skills.
Design/methodology/approach
The research reported here was conducted using primary and secondary sources. Industry data were collected through focused groups and roundtable discussions. Online sources, magazines, newspapers and books are referred to as secondary sources, and the data collected are critically analyzed to reach a conclusion.
Findings
There is a significant increase in foreign and domestic tourists, and the subsectors discussed are very closely linked to food, health, traditional cooking, regional and seasonal cuisines. The demand for Indian food and slow cooking is increasing; however, despite various government initiatives, there is no significant improvement in the skill set of the available labor. As food is an important component of all tourism packages, there is a particular need for public–private partnerships to take the Skill India initiative to the next level. That said, academic standards and curriculum must align with international quality frameworks and be in sync with current and future industry demands and benchmarks.
Research limitations/implications
The dependence on the sources available online and their credibility remains the biggest challenge; however, increasing the sample size and more participation from nodal bodies and government officials would have broadened the base of the study.
Originality/value
The research adds value for industry leaders and policymakers at large. Educational institutions, students and hoteliers will find it useful as they attempt to bridge the gap and plan a roadmap according to industry requirements.
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Gourav Jamwal, Sanjay Sharma and R.K. Awasthi
This paper aims to evaluate the various dynamic performance parameters of hydrodynamic journal bearings. For this, the bearing’s inner surface is textured with chevron-shaped…
Abstract
Purpose
This paper aims to evaluate the various dynamic performance parameters of hydrodynamic journal bearings. For this, the bearing’s inner surface is textured with chevron-shaped textures with different texture depths and number of textures in different regions/locations.
Design/methodology/approach
In the present study, the effect of chevron-shaped texture having different values of texture depths, locations and number of textures has been numerically simulated. The dynamic performance characteristics have been calculated by solving the fluid flow governing Reynolds equation using the finite element method, assuming iso-viscous and Newtonian fluid.
Findings
The obtained results indicate that the bearing stability can be improved with the help of surface texture. Among all the investigated texture locations, the maximum increase in stability threshold speed is observed for fully textured distribution. Moreover, for the chevron-shaped texture considered in the present study, the optimum values of texture depth and number of textures have also been determined for maximum bearing stability.
Practical implications
While designing, designers should focus on those optimum values of texture depth, texture location and number of textures which lead to maximum enhancement in bearing stability.
Originality/value
This study is useful in the appropriate selection of chevron-shaped texture parameters on bearing surface for the maximum bearing stability.
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Sandeep Munjal and Sanjay Sharma
This concluding article identifies the varying perspectives and research findings that emanate from the collection of articles in this theme issue. It also revisits the theme…
Abstract
Purpose
This concluding article identifies the varying perspectives and research findings that emanate from the collection of articles in this theme issue. It also revisits the theme issue question and provides some directions for further research in the form of a call for action based on the key findings of this issue. It is apparent that there is an urgent need for hospitality education in the higher education sector to give space and focus to sustainability practices in their curriculum and ensure that the content is embedded and delivered in a contemporary way. Further, the faculty should be up-to-date and understand their role as drivers of the sustainability footprint for tourism and hospitality. The authors argue that hospitality education not only needs to catch up but also make a determined effort to lead applied research that can inform the industry in terms of what and how more can be done to mitigate the negative impacts of tourism activity.
Design/methodology/approach
The paper draws on a content analysis of the article collection in this theme issue: How is hospitality education embedding sustainable practices in their curriculum and programme delivery? An Asian perspective is considered here in order to summarize, conclude and suggest some next steps.
Findings
There is an urgent need to support and advance the cause of sustainability in tourism and hospitality, especially in the Asian context. The paper identifies key steps that need to be taken by the hospitality higher education sector in order to contribute to the larger goal of sustainable practices that can be easily understood and adopted by those managing hospitality businesses.
Originality/value
The paper documents the theme issue findings and provides a collaborative research agenda based on the findings of the theme issue writing team.
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Sanjay Sharma, Gourav Jamwal and R.K. Awasthi
The purpose of this paper is to provide the various steady state parameters of hydrodynamic journal bearings have been determined to get maximum performance enhancement ratio. For…
Abstract
Purpose
The purpose of this paper is to provide the various steady state parameters of hydrodynamic journal bearings have been determined to get maximum performance enhancement ratio. For this, the bearings inner surface is textured with triangular shape with different texture depths and a number of textures in pressure increasing region. The textured region acts as a lubricant reservoir, which provides additional film-thickness and reduce friction. Therefore, enhance the overall performance of bearing.
Design/methodology/approach
In the present study, the effect of triangular shaped texture on the static performance characteristics of a hydrodynamic journal bearing has been studied. Different values of texture depths and a number of textures have been numerically simulated in pressure developing region. The static performance characteristics have been calculated by solving the fluid flow governing Reynolds equation using the finite element method, assuming iso-viscous Newtonian fluid. The performance enhancement ratio, which is the ratio of load carrying capacity (LCC) to the coefficient of friction (COF) has been calculated from results to finalized optimum design parameters.
Findings
The paper provides numerically obtained results indicate that surface texturing can improve bearing performance if the textured region is placed in the pressure increasing region. Moreover, surface texturing is the most effective at bearing performance enhancement when the bearing operates at lower eccentricity ratios and texture depth. The performance enhancement ratio, which is the ratio of LCC to the COF is found to be a maximum value of 2.198 at texture depth of 1.5, eccentricity ratio of 0.2 and the textured region located in the increasing pressure region.
Research limitations/implications
The present study is based on a numerical based research approach, which has its limitations. So, researchers are encouraged to investigate the same work experimentally.
Practical implications
The paper includes implications to be beneficial for designers for designing better hydrodynamic journal bearings.
Originality/value
For the triangular shaped texture, considered in the present study, the optimum values of texture depth and texture distribution region have also been determined. While designing, designers should focus on those values of texture depth, texture region and a number of textures, which give the maximum value of performance enhancement ratio, which represents maximum LCC at the lowest value of the COF.
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