Ravishanker Baliga, Sharat K. Rao, Raghuvir Pai, Satish B. Shenoy, Atmananda K. Hegde, Shubham Swaroop and Abhijeet Shetkar
The purpose of this paper is to investigate by means of finite element analysis (FEA), the effect of polyethylene insert thickness and implant material, under axial loading…
Abstract
Purpose
The purpose of this paper is to investigate by means of finite element analysis (FEA), the effect of polyethylene insert thickness and implant material, under axial loading following TKA.
Design/methodology/approach
The 3D geometric model of bone was processed using the CT scan data by MIMICS (3matic Inc.), package. Implant components were 3D scanned and subsequently 3D modeled using ANSYS Spaceclaim and meshed in Hypermesh (Altair Hyperworks). The assembled, meshed bone-implant model was then input to ABAQUS for FE simulations, considering axial loading.
Findings
Polyethylene insert thickness was found to have very little or no significance (p>0.05) on the mechanical performance, namely, stress, strain and stress shielding of bone-implant system. Implant material was found to have a very significant effect (p<0.05) on the performance parameters and greatly reduced the high stress zones up to 60 percent on the tibial flange region and periprosthetic region of tibia.
Originality/value
Very few FEA studies have been done considering a full bone with heterogeneous material properties, to save computational time. Moreover, four different polyethylene insert thickness with a metal-backed and all-poly tibial tray was considered as the variables affecting the bone-implant system response, under static axial loading. The authors believe that considering a full bone shall lead to more precise outcomes, in terms of the response of bone-implant system, namely, stress, strains and stress shielding in the periprosthetic region, to loading.
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Satish Shenoy and Raghuvir Pai
The paper aims to devise an externally adjustable fluid film bearing whereby the hydrodynamic conditions can be changed as required in a controlled manner. Unlike a tilting pad…
Abstract
Purpose
The paper aims to devise an externally adjustable fluid film bearing whereby the hydrodynamic conditions can be changed as required in a controlled manner. Unlike a tilting pad bearing, in this bearing film thickness can be varied by providing radial and tilt adjustments to the pad, irrespective of the operating conditions. This variation in film thickness in‐turn varies the stiffness and damping coefficients.
Design/methodology/approach
The stability characteristics of a centrally loaded 120° single pad externally adjustable fluid film bearing is studied theoretically. The bearing has an aspect ratio of one and operates over a wide range of eccentricity ratios and adjustments. The time dependent form of Reynolds equation in two dimensions is solved numerically using the finite difference method. Dynamic performance characteristics of the bearing are in terms of film stiffness and damping coefficients, critical mass of the journal and the whirl frequency ratio. Stability is determined using a first‐order‐linear‐perturbation method.
Findings
The paper finds that a study with various adjustments predicts that negative radial and negative tilt adjustment configuration results in superior dynamic characteristics as compared to a conventional fluid film bearing.
Originality/value
It is possible to have a particular set of radial and tilt adjustments that will provide a stable operation of the rotor bearing system. Single pad externally adjustable fluid film bearing will perform as a conventional partial arc bearing when both the adjustments are set to zero.
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The purpose of this paper is to study theoretically the combined influence of journal misalignment and wear on the performance of a hole‐entry hybrid journal bearing system. The…
Abstract
Purpose
The purpose of this paper is to study theoretically the combined influence of journal misalignment and wear on the performance of a hole‐entry hybrid journal bearing system. The bearing is assumed to be operating in a turbulent regime.
Design/methodology/approach
The modified Reynolds equation based on Constantinescu lubrication theory has been solved by using finite element method together with orifice and capillary restrictors flow equations as a constrain together with appropriate boundary conditions.
Findings
It has been observed that for a symmetric hole‐entry journal bearing configuration the value of h¯min is more for the bearing compensated by orifice restrictor as compared to capillary restrictor when bearing operates in turbulent regime under worn/unworn conditions. From the point of view of stability threshold speed ω¯th, the reduction in the value of ω¯th for capillary compensated bearing is around −3.89 percent whereas for orifice compensated bearing it is −7.85 percent when misaligned worn bearing is operating in turbulent regime.
Originality/value
The present work is original of its kind, in case of misaligned hole‐entry worn journal bearing. The results are quite useful for the bearing designer.
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Debidutta Pattnaik, Satish Kumar and Ashutosh Vashishtha
Trade credit (TC) is a financing provision by non-financing firms. The multi-disciplinary research field has sustained scholarly attention for long. Pursuant to the gap for a…
Abstract
Purpose
Trade credit (TC) is a financing provision by non-financing firms. The multi-disciplinary research field has sustained scholarly attention for long. Pursuant to the gap for a comprehensive summary of the literature confined to the areas of Finance and Economics, this study aims to provide quantitative and qualitative insights not fully captured or analysed in previous reviews.
Design/methodology/approach
Contextualized systematic literature review (SLR) and bibliometric techniques are used to map the thematic, intellectual and conceptual structures latent in 138 articles published in top journals.
Findings
The top authors, top journals and major themes are recognized using bibliometric techniques followed by an in-depth bibliographic-network-based-content-analysis. Five major clusters indicating the five research dimensions within the specialized field are identified and extensively reviewed. Empirical validation of key theories is discussed in the contents and a conceptual model is developed. Finally, the study has identified key research gaps to set the direction for future research.
Research limitations/implications
The scope of the literature selection is confined to the areas of finance and economics. Future studies could elaborate on a broader perspective.
Originality/value
The study contributes by offering a conceptual model latent in the literature on TC. It derives major research gaps to set the direction of future research. Also, the combination of SLR and bibliometrics is a methodological contribution in this research domain.
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This chapter primarily aims to revisit and explore the theoretical underpinnings of social entrepreneurship and dwell into what unfolds while amalgamating the conventionally…
Abstract
This chapter primarily aims to revisit and explore the theoretical underpinnings of social entrepreneurship and dwell into what unfolds while amalgamating the conventionally considered to be dissimilar design of business entrepreneurship and the social impact? Can the prefix “social” of social entrepreneurship transform the innate characteristics of entrepreneurship? Is social entrepreneurship an essentiality in a ground-breaking playing field in the business research to facilitate new theories and concepts or a rehash of the corporate responsibility debate? Is it just an appellation or does the underscored social label and its construct allow for new possibility to be explored into the sociality of entrepreneurship along with the new-fangled entrepreneurialism in society? The chapter attempts to decode these more germane and interwoven issues like do we have to tell apart between a capitalist entrepreneurship and a non-capitalist one? Or between pioneering and replicative entrepreneurs. Can we sanctify the political in the social spheres and who (which actors) actually sets the discourse of social needs. The chapter also tracks multiple cases in the Indian locale to determine the robust application of the concept while unpacking the Indian context of social entrepreneurship. These cases are randomly selected from assorted sectors and are wide in its sweep and scope. These cases highlight on the lived experiences, where the task is truly played out. This adds to the sensibilities of new entrepreneurs and policy framers who face the challenges.
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Nathi Ram and Satish C. Sharma
The present work aimed to study analytically the influence of wear on the performance of a capillary-compensated hole-entry hybrid misaligned journal bearing system operating in a…
Abstract
Purpose
The present work aimed to study analytically the influence of wear on the performance of a capillary-compensated hole-entry hybrid misaligned journal bearing system operating in a turbulent regime. The numerically simulated results are presented for the chosen values of restrictor design parameter, Reynolds numbers, wear depth and misalignment parameters.
Design/methodology/approach
The wear caused on the bearing surface due to start/stop operations is modeled using the Dufrane’s abrasive wear model. The modified Reynolds equation based on Constantinescu’s lubrication theory is solved using finite element method together with capillary restrictor flow equation.
Findings
It is found that the value of minimum fluid-film thickness increases significantly for a constant value of restrictor design parameter when unworn aligned bearing operates in turbulent regime vis-à-vis laminar regime. Further, it has also been observed that when a worn bearing operates in laminar/turbulent regimes, the reduction in the value of minimum fluid-film thickness is more due to journal misalignment as compared to the aligned bearing operates in laminar regime.
Originality/value
The present work is original concerning the performance of worn hole-entry hybrid misaligned journal bearing system operating in turbulent regime. The results are expected to be quite useful for the bearing designer.
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Neeti Mathur, Satish Chandra Tiwari, T. Sita Ramaiah and Himanshu Mathur
This research paper aims to explore the relationship of financial performance and capital structure of Indian pharma firms of BSE 500, the impact of research and development (R&D…
Abstract
Purpose
This research paper aims to explore the relationship of financial performance and capital structure of Indian pharma firms of BSE 500, the impact of research and development (R&D) expenditure on financial performance and also explore the moderating role of competitive intensity between the existing relationship of capital structure and firm performance.
Design/methodology/approach
The balanced panel data of listed pharma firms of BSE 500 are used for the research study, and the present study adopts both the panel and ordinary least square (OLS) estimation techniques to draw the results.
Findings
The results exhibit that the high debt ratio is harmful for the accounting performance of the selected sample of pharma firms of BSE 500. Besides, market competition negatively moderates the relationship between capital structure and firm performance.
Research limitations/implications
The research findings provide evidence for the policymakers/regulators that the sample firms should discourage the high debt financing in the presence of competitive intensity in the product marketplace.
Originality/value
The core contribution of the current research is to examine impact of R&D expenditure on financial performance and the moderating role of market competition on the relationship of capital structure and firm performance to the best of the authors' knowledge, and no single study has previously explored this relationship in the context of BSE 500 pharma firms.
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Sunith Hebbar, Mahesh Prabhu H., Sakshi Laddha and Adithi Udupa
Intense competition in every sector has put administrators under tremendous pressure to develop strategies for survival, and the educational sector is no exception. This paper…
Abstract
Purpose
Intense competition in every sector has put administrators under tremendous pressure to develop strategies for survival, and the educational sector is no exception. This paper aims to explore the dynamics between the factors that affect the quality of engineering institutes by developing an interpretive model.
Design/methodology/approach
The factors that affect the quality of engineering institutes are identified through a thorough review of extant literature, and the dynamics between them are studied using the total interpretive structural modeling (TISM) technique. The developed model has also been statistically validated.
Findings
Results indicate that top management leadership, location and infrastructure drive academics, research and consultancy, industry collaboration and placements, resulting in accreditation from global agencies, thereby improving the institute’s quality.
Research limitations/implications
The TISM framework was developed based on the suggestions of the majority of respondents rather than using a fuzzy one, which requires a much larger data set. Nevertheless, the bias of the majority approach can be removed by multiple conversations with respondents. Secondly, the model development and validation are based on the perceptions of faculty members working at engineering institutes in India. Scholars can extend the work in the future by identifying additional factors and considering administrators’ perceptions.
Originality/value
The study integrates the factors that impact the quality of engineering institutes in a unique way to understand their combined impact. The developed framework will assist policymakers in identifying and dedicating adequate resources to essential factors that drive the other factors, thereby enhancing the institute’s ranking.