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Article
Publication date: 1 April 2009

K. Tamil Mannan, Rakesh Saxena, 2R. Murugavel and P.L. Sah

Pressure vessel is a closed cylindrical vessel for storing gaseous, liquids or solid products. The stored medium is at a particular pressure and temperature. The…

Abstract

Pressure vessel is a closed cylindrical vessel for storing gaseous, liquids or solid products. The stored medium is at a particular pressure and temperature. The cylindrical vessel is closed at both ends by means of dished head, which may be hemispherical, ellipsoidal. The pressure vessels may be horizontal or vertical. The supporting system of this vertical vessel plays an important role in the performance of the equipment. Proper supporting system gives better efficiency. The bottom supports are critical components since they are to be designed with much care to avoid failure due to internal pressure with temperature. In this analysis, skirt support for vertical vessel was analyzed as per the guidelines given in the ASME (American Society of Mechanical Engineering) section VIII division 2 and IBR (Indian Boiler Regulations) standards. The stress analysis was carried out for this support using a general purpose FEM code, ANSYS macros. The coupled field (Structural and Thermal) Analysis was carried out for skirt support to find out the stresses in the support. The analysis’s results were compared with ASME code allowable stress values.

Details

Multidiscipline Modeling in Materials and Structures, vol. 5 no. 4
Type: Research Article
ISSN: 1573-6105

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Article
Publication date: 1 January 2008

P. Sathiya, N. Siva Shanmugam, T. Ramesh and R. Murugavel

Friction stir welding (FSW), a process that involves joining of metals without fusion of filler materials. It is used already in routine, as well as critical application…

Abstract

Friction stir welding (FSW), a process that involves joining of metals without fusion of filler materials. It is used already in routine, as well as critical application for the joining of structural components made of Aluminum and its alloys. Indeed it has been convincingly demonstrated that the process results in strong and ductile joints, some times in systems, which have proved difficult using conventional welding techniques. The process is most suitable for components that are flat & long (plates & sheets) but it can be adapted for pipes, hollow sections and positional welding. The welds are created by the combined action of frictional heating and mechanical deformation, due to a rotating tool. Recently, a new technology called friction stir spot welding (FSSW) has been developed that has a several advantages over the electric resistance welding process widely used in automotive industry in terms of weld quality and process efficiency. This welding technology involves a process similar to FSW, except that, instead of moving the tool along the weld seam, the tool only indents the parts, which are placed on top of each other. The conditions under which the deposition process in FSSW is successful are not fully understood. However, it is known that only under specific thermo‐mechanical conditions does a weld formation occur. The objective of the present work is to analyze the primary conditions under which the cavity behind the tool is filled. For this, a fully coupled thermo‐mechanical three‐dimensional FE model has been developed in ABAQUS/Explicit using the adaptive meshing scheme and the Johnson‐Cook material law. The contact forces are modeled by Coulomb’s law of friction, making the contact condition highly solution dependent. Temperature graph in the radial direction as well as stress, strain plots are presented.

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Multidiscipline Modeling in Materials and Structures, vol. 4 no. 1
Type: Research Article
ISSN: 1573-6105

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Book part
Publication date: 17 March 2020

Jordan G. Smith, Michelle L. Flynn, Marissa L. Shuffler, Dorothy R. Carter and Amanda L. Thayer

Meetings can serve the important role of facilitating communication and coordination for systems of teams known as “multiteam systems” (MTSs) that work interdependently to…

Abstract

Meetings can serve the important role of facilitating communication and coordination for systems of teams known as “multiteam systems” (MTSs) that work interdependently to achieve grand societal challenges. Given that MTSs often appear in complex, ambiguous, urgent, and multifaceted task contexts, the MTSs require effective, and efficient but thorough, communication within and between teams in order to achieve shared goals. However, the extant literature regarding the science of meetings has left much to be explored in regard to the inter- and intrateam influences and impacts. This chapter considers the significance of meetings and their practical value in facilitating MTS processes and performance by leveraging what is known thus far regarding MTS structural attributes, their value, their challenges, and opportunities, integrating this foundation with the broader science of meetings. Building on this rationale, the authors move toward empirically and theoretically derived considerations for how meetings may best be designed, facilitated and utilized for MTS effectiveness, as guided by our current understanding of critical MTS attributes.

Details

Managing Meetings in Organizations
Type: Book
ISBN: 978-1-83867-227-0

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Article
Publication date: 18 April 2019

Isam Tareq Abdullah and Sabah Khammass Hussein

The purpose of this paper is to join a sheet of the AA7075 with the high-density polyethylene (HDPE) by a lap joint using friction spot processing and investigate the…

Abstract

Purpose

The purpose of this paper is to join a sheet of the AA7075 with the high-density polyethylene (HDPE) by a lap joint using friction spot processing and investigate the temperature distribution of joint during this process using the finite element method (FEM).

Design/methodology/approach

A semi-conical hole was manufactured in the AA7075 specimen and a lap joint configuration was prepared with the HDPE specimen. A rotating tool was used to generate the required heat to melt the polymer by the friction with the AA7075 specimen. The applied tool force moved the molten polymer through the hole. Four parameters were used: lower diameter of hole, rotating speed, plunging depth and time. The results of shear test were analyzed using the Taguchi method. A FEM was presented to estimate the temperature distribution of joint during the process.

Findings

All specimens failed by shearing the polymer at the lap joint region without dislocation. The specimens of the smallest diameter exhibited the highest shear strength at the lap joint. The maximum ranges of temperature were recorded at the contact region between the rotating tool and the AA7075 specimen. The tool plunging depth recorded the highest effect on the generated heat compared with the rotating speed and plunging time.

Originality/value

For the first time, the AA7075 sheet was joined with the HDPE sheet by friction spot processing. The temperature distribution of this joint was simulated using the FEM.

Details

International Journal of Structural Integrity, vol. 10 no. 4
Type: Research Article
ISSN: 1757-9864

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Article
Publication date: 19 July 2019

Hamid Reza Goshayeshi and Mohammad Reza Safaei

Solar-driven water desalination technologies are rapidly developing with various links to other renewable sources. However, the efficiency of such systems severely depends…

Abstract

Purpose

Solar-driven water desalination technologies are rapidly developing with various links to other renewable sources. However, the efficiency of such systems severely depends on the design parameters. This paper presents results from an investigation on the effect of the glass cover inclination angle on the performance of two stepped solar still geometries (flat and convex) and the amount of produced distilled water.

Design Methodology Approach

Studied inclination angles of 25°, 27.5°, 30°, 32.5° and 35° were chosen, while other design parameters were fixed.

Findings

The investigation showed that the unit with the convex absorber plate had higher average water daily production rate, compared to the output of the flat absorber plate unit. The results also depicted that the inclination angle of the still has a noticeable effect on the performance of solar stills. The value of the critical angle is 32.5°, and the higher inclination angle results in less heat transfer coefficient. This value can be used for design purposes and erases the typical assumption to use lower angles to optimize the productivity of the still.

Practical Implications

Finally, obtained data were used to correlate the Nusselt number for the flat and convex surfaces with different inclination angles of the glass cover.

Originality Value

The outcome of this investigation may find applications to develop highly efficient solar stills to secure more drinkable water in warm, dry lands.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 30 no. 6
Type: Research Article
ISSN: 0961-5539

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Article
Publication date: 9 November 2012

R. Farnoosh, P. Nabati and A. Hajirajabi

The main purpose of this paper is to estimate the resistance and inductor in the RL electrical circuit when these are unavailable or missing data that it is a concern in…

Abstract

Purpose

The main purpose of this paper is to estimate the resistance and inductor in the RL electrical circuit when these are unavailable or missing data that it is a concern in electrical engineering. The input voltage is assumed to be corrupted by the noise and the current is observed at discrete time points.

Design/methodology/approach

The authors propose a computationally efficient framework for parameters estimation using least square estimator and Bayesian Monte Carlo scheme.

Findings

The explicit formulas for least square estimator are derived and the strong consistency of resistance estimator is verified when inductor is a known parameter, then Bayesian estimation of parameters governed by using Markov chain Monte Carlo methods. The applicability of the results is demonstrated by using numerical examples. Several numerical results and figures are presented via Matlab and R programming to illustrate the performance of the estimators.

Practical implications

The paper can be used in various types of electrical engineering real time projects. The projects include electrical circuits, electrical machines theory and drives, especially when the parameters are uncertain that it is a worry in electrical engineering.

Originality/value

To the author's best knowledge, least square and Bayesian estimation of resistance and inductor have not been studied before. The proposed model is nonlinear with respect to inductor (L); therefore the present work has fundamental difference in comparison with the similar models.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 31 no. 6
Type: Research Article
ISSN: 0332-1649

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Book part
Publication date: 17 March 2020

Roni Reiter-Palmon, Salvatore Leone, Vignesh Murugavel and Joseph A. Allen

Debriefs are a type of workplace meeting that often use after events and critical incidents. Debriefs are used to review performance, promote shared learning and…

Abstract

Debriefs are a type of workplace meeting that often use after events and critical incidents. Debriefs are used to review performance, promote shared learning and understanding, and improve future team performance. Similarly, reflexivity refers to the extent to which team members reflect upon and openly discuss group processes, procedures, and actions to improve future team performance. In this chapter, the authors review the separate literatures and explore the relationship between debriefs and reflexivity. While the debrief literature does focus on aspects of reflection, what occurs between the aspects of reflection, planning, and action is left unexplored. The concept of reflexivity fits well with the successful use of debriefs, as reflexivity ensures that reflection results in outcomes and moves beyond just an overview or discussion during debriefing. Additionally, important constructs such as psychological safety and sensemaking are relevant to both debriefs and reflexivity such that open and honest discussion as well as developing shared understanding are necessary for effective debriefing and reflection. Using the constructs of psychological safety and sensemaking, the authors propose a model that situates both reflexivity and effective debriefs in the context of team learning. This model integrates team reflexivity with team debriefs, provides a better understanding of how teams can carry out more effective debriefs, and explains how more effective debriefing and greater team reflexivity lead to enhanced learning and improvement in team performance.

Details

Managing Meetings in Organizations
Type: Book
ISBN: 978-1-83867-227-0

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Book part
Publication date: 17 March 2020

Abstract

Details

Managing Meetings in Organizations
Type: Book
ISBN: 978-1-83867-227-0

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Article
Publication date: 8 February 2021

Siddhesh Umesh Mestry, Umesh Ratan Mahajan, Aswathy M. and Shashank T. Mhaske

The purpose of this paper is to use the bio-based resource as the starting material for the synthesis of azo dye. Cardanol is one of the most used bio-based resources for…

Abstract

Purpose

The purpose of this paper is to use the bio-based resource as the starting material for the synthesis of azo dye. Cardanol is one of the most used bio-based resources for carrying out the synthesis of various compounds having numerous end applications. The study presents an attempt to develop an azo dye from Cardanol having end applications in pH-responsive dyes.

Design/methodology/approach

The cardanol was sulfonated to block the para position by which ortho positioned hydroxyl group after diazotization and coupling will provide necessary pH-sensitivity. The diazotization of two naphthalene derivatives, i.e. 1-naphthol-8-amino-3,6-disulfonic acid (H-acid) and 7-amino-4-hydroxy-2-naphthalene sulfonic acid (J-acid) was carried out using the standard practice, and the diazotized compounds were coupled with the sulfonated cardanol. The obtained dyes were characterized by Fourier transform infrared, nuclear magnetic resonance, carbon-hydrogen-nitrogen-sulfur analysis and hydroxyl value. The colour properties were checked using UV-vis spectrophotometry and density functional theory, while thermogravimetric analysis was used for the thermal degradation studies of both the dyes.

Findings

Water-soluble cardanol-based azo dyes were prepared successfully having good thermal stability, and the obtained results are being presented in this paper.

Originality/value

The originality lies between the use of cardanol as a bio-based resource for the synthesis of azo-dye and the obtained azo-dye has the pH-sensitivity.

Details

Pigment & Resin Technology, vol. 50 no. 3
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 26 August 2014

Mohammad Fahim Ansari, Gautam Sarkhel, Dipendra Nath Goswami and Bangali Baboo

– The purpose of this paper is to improve the properties of shellac by blending with epoxidised novolac resin for its use as coating material for metal surfaces.

Abstract

Purpose

The purpose of this paper is to improve the properties of shellac by blending with epoxidised novolac resin for its use as coating material for metal surfaces.

Design/methodology/approach

Epoxidised-novolac resin was synthesised by epoxidation of novolac resin, which in turn was synthesised by reaction of phenol with formaldehyde. The epoxidised-novolac resin was blended with different weight ratios of shellac ranging 10-50 weight per cent with an interval of 10 weight per cent. Films of the blends were studied for different coating properties using standard procedure.

Findings

Significant improvement in coating properties of shellac such as gloss, scratch hardness and impact resistance was observed on blending with epoxidised novolac resin. Resistance towards water and alkali increased, while acid resistance decreased, with the increase in concentration of epoxidised novolac resin in the blends. Contact angle measurement revealed that blends showed more resistance towards polar solvent than non-polar ones.

Research limitations/implications

Epoxidised-novolac resin used in the study was synthesised of epoxy equivalent of 187. Epoxidised-novolac resin of different epoxy equivalent can also be synthesised and used for blending and studying the properties.

Practical implications

Blending of shellac with epoxidised-novolac resin improved the coating properties of shellac, which was further enhanced with the treatment of butylated melamine formaldehyde resin. The formulation can be used as coating material for metal surfaces.

Originality/value

Blending of shellac with epoxidised-novolac resin was done for the first time. The formulation can be utilised for developing coating material for metal surfaces.

Details

Pigment & Resin Technology, vol. 43 no. 5
Type: Research Article
ISSN: 0369-9420

Keywords

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