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Book part
Publication date: 23 November 2016

Jennifer C. Coats and Frederick W. Rankin

Despite the benefits of delegation, anecdotal and survey-based evidence suggests that firms do not optimally delegate decision-making authority. However, to date, no…

Abstract

Purpose

Despite the benefits of delegation, anecdotal and survey-based evidence suggests that firms do not optimally delegate decision-making authority. However, to date, no quantifiable evidence supports this claim.

Methodology/approach

We design an experiment to explore the superior’s choice between delegation and information elicitation. We also examine the effect of the superiors’ choice on the amount of effort provided by subordinates to gather decision-facilitating information.

Findings

We find that, compared to economic predictions, superiors delegate less often than they should. Subordinates exert lower effort when superiors elicit information than when superiors delegate the decision to them. As a result, superiors earn lower profit when they elicit information than when they delegate decision-making authority.

Research implications

Our empirical evidence supports two main tenets espoused in the literature on the allocation of decision rights. First, the evidence of under delegation contributes to the literature which maintains that superiors’ tendency to under-delegate leads firms to become overly centralized.

Originality/value

By designing a novel experimental, we identify systematic ways in which behavior deviates from economic theory and contribute to the discussion on how firms utilize information. In particular, under delegation prevents firms from exploiting economies that arise from local capabilities and task specialization, and results in forgone profits.

Details

Advances in Management Accounting
Type: Book
ISBN: 978-1-78560-972-5

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Book part
Publication date: 23 November 2016

Abstract

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Advances in Management Accounting
Type: Book
ISBN: 978-1-78560-972-5

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Book part
Publication date: 30 June 2004

Denise A Copelton

In 1920 Margaret Sanger called voluntary motherhood “the key to the temple of liberty” and noted that women were “rising in fundamental revolt” to claim their right to…

Abstract

In 1920 Margaret Sanger called voluntary motherhood “the key to the temple of liberty” and noted that women were “rising in fundamental revolt” to claim their right to determine their own reproductive fate (Rothman, 2000, p. 73). Decades later Barbara Katz Rothman reflected on the social, political and legal changes produced by reproductive-rights feminists since that time. She wrote: So the reproductive-rights feminists of the 1970s won, and abortion is available – just as the reproductive-rights feminists of the 1920s won, and contraception is available. But in another sense, we did not win. We did not win, could not win, because Sanger was right. What we really wanted was the fundamental revolt, the “key to the temple of liberty.” A doctor’s fitting for a diaphragm, or a clinic appointment for an abortion, is not the revolution. It is not even a woman-centered approach to reproduction (2000, p. 79).

Details

Gendered Perspectives on Reproduction and Sexuality
Type: Book
ISBN: 978-0-76231-088-3

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Article
Publication date: 10 August 2015

Mica Grujicic, Jennifer Snipes, Ramin Yavari, S. Ramaswami and Rohan Galgalikar

The purpose of this paper is to prevent their recession caused through chemical reaction with high-temperature water vapor, SiC-fiber/SiC-matrix ceramic-matrix composite…

Abstract

Purpose

The purpose of this paper is to prevent their recession caused through chemical reaction with high-temperature water vapor, SiC-fiber/SiC-matrix ceramic-matrix composite (CMC) components used in gas-turbine engines are commonly protected with so-called environmental barrier coatings (EBCs). EBCs typically consist of three layers: a top thermal and mechanical protection coat; an intermediate layer which provides environmental protection; and a bond coat which assures good EBC/CMC adhesion. The materials used in different layers and their thicknesses are selected in such a way that the coating performance is optimized for the gas-turbine component in question.

Design/methodology/approach

Gas-turbine engines, while in service, often tend to ingest various foreign objects of different sizes. Such objects, entrained within the gas flow, can be accelerated to velocities as high as 600 m/s and, on impact, cause substantial damage to the EBC and SiC/SiC CMC substrate, compromising the component integrity and service life. The problem of foreign object damage (FOD) is addressed in the present work computationally using a series of transient non-linear dynamics finite-element analyses. Before such analyses could be conducted, a major effort had to be invested toward developing, parameterizing and validating the constitutive models for all attendant materials.

Findings

The computed FOD results are compared with their experimental counterparts in order to validate the numerical methodology employed.

Originality/value

To the authors’ knowledge, the present work is the first reported study dealing with the computational analysis of the FOD sustained by CMCs protected with EBCs.

Details

Multidiscipline Modeling in Materials and Structures, vol. 11 no. 2
Type: Research Article
ISSN: 1573-6105

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Article
Publication date: 18 March 2020

Jennifer Eickworth, Enes Aydin, Martin Dienwiebel, Thomas Rühle, Patrick Wilke and Tobias Reinhard Umbach

Interactions of different additive types for antiwear/friction modification on surfaces can be synergistic or antagonistic in nature. This paper aims to investigate…

Abstract

Purpose

Interactions of different additive types for antiwear/friction modification on surfaces can be synergistic or antagonistic in nature. This paper aims to investigate whether there are interactions between different additives in the adsorption process and whether they synergistic or antagonistic. The yielded correlations will be validated with tribological experiments to answer the question whether synergistic effects in adsorption also lead to synergistic effects in wear reduction.

Design/methodology/approach

In a representative study, zinc dialkyl-dithiophosphate and dithiophosphate were elaborated in combination with two different friction modifiers, a glycerol monooleate and an organic friction modifier. As base oils, mineral oil and poly alpha olefine were used. The adsorption behavior was studied via quartz crystal microbalance with dissipation using Fe2O3 coated quartz crystals. The tribological performance was evaluated in a ball-on-three disk tribometer. White light interferometry was used to determine the wear volume and X-ray photoelectron spectroscopy depth profiles of the tribofilms were obtained on selected systems.

Findings

The combination of dithiophosphate and an organic friction modifier (OFM) revealed a synergistic effect in terms of wear. If the initially formed films are viscoelastic, the third body formation during a tribo experiment is more pronounced and thereby wear can be reduced. As a mechanism, the adsorption of the OFM on the formed antiwear layer is proposed.

Originality/value

Correlating the analytical findings with performance experiments provides further understanding of the interactions between different constituents and their implications on film formation processes and wear reduction mechanisms.

Peer review

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-07-2019-0293/

Details

Industrial Lubrication and Tribology, vol. 72 no. 8
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 8 August 2016

Mica Grujicic, S Ramaswami, Jennifer Snipes, Ramin Yavari and Philip Dudt

The purpose of this paper is to optimize the design of the advanced combat helmet (ACH) currently in use, by its designers in order to attain maximum protection against…

Abstract

Purpose

The purpose of this paper is to optimize the design of the advanced combat helmet (ACH) currently in use, by its designers in order to attain maximum protection against ballistic impacts (fragments, shrapnel, etc.) and hard-surface/head collisions. Since traumatic brain injury experienced by a significant fraction of the soldiers returning from the recent conflicts is associated with their exposure to blast, the ACH should be redesigned in order to provide the necessary level of protection against blast loads. In the present work, augmentations of the ACH for improved blast protections are considered. These augmentations include the use of a polyurea (a nano-segregated elastomeric copolymer)-based ACH external coating/internal lining.

Design/methodology/approach

To demonstrate the efficacy of this approach, instrumented (unprotected, standard-ACH-protected, and augmented-ACH-protected) head-mannequin blast experiments are carried out. These experimental efforts are complemented with the appropriate combined Eulerian/Lagrangian transient non-linear dynamics computational fluid/solid interaction analysis.

Findings

The results obtained indicated that: when the extent of peak over-pressure reduction is used as a measure of the blast-mitigation effectiveness, polyurea-based augmentations do not noticeably improve, and sometimes slightly worsen, the performance of the standard ACH; when the extent of specific impulse reduction is used as a measure of the blast-mitigation effectiveness, application of the polyurea external coating to the standard ACH improves the blast-mitigation effectiveness of the helmet, particularly at shorter values of the charge-detonation standoff distance (SOD). At longer SODs, the effects of the polyurea-based ACH augmentations on the blast-mitigation efficacy of the standard ACH are inconclusive; and the use of the standard ACH significantly lowers the accelerations experienced by the skull and the intracranial matter. As far as the polyurea-based augmentations are concerned, only the internal lining at shorter SODs appears to yield additional reductions in the head accelerations.

Originality/value

To the authors’ knowledge, the present work contains the first report of a combined experimental/computational study addressing the problem of blast-mitigation by polyurea-based augmentation of ACH.

Details

International Journal of Structural Integrity, vol. 7 no. 4
Type: Research Article
ISSN: 1757-9864

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Article
Publication date: 18 November 2013

Mica Grujicic, Jennifer Snipes, Subrahmanian Ramaswami, Rohan Galgalikar, James Runt and James Tarter

Polyurea is an elastomeric two-phase co-polymer consisting of nanometer-sized discrete hard (i.e. high glass transition temperature) domains distributed randomly within a…

Abstract

Purpose

Polyurea is an elastomeric two-phase co-polymer consisting of nanometer-sized discrete hard (i.e. high glass transition temperature) domains distributed randomly within a soft (i.e. low glass transition temperature) matrix. A number of experimental investigations reported in the open literature clearly demonstrated that the use of polyurea external coatings and/or internal linings can significantly increase blast survivability and ballistic penetration resistance of target structures, such as vehicles, buildings and field/laboratory test-plates. When designing blast/ballistic-threat survivable polyurea-coated structures, advanced computational methods and tools are being increasingly utilized. A critical aspect of this computational approach is the availability of physically based, high-fidelity polyurea material models. The paper aims to discuss these issues.

Design/methodology/approach

In the present work, an attempt is made to develop a material model for polyurea which will include the effects of soft-matrix chain-segment molecular weight and the extent and morphology of hard-domain nano-segregation. Since these aspects of polyurea microstructure can be controlled through the selection of polyurea chemistry and synthesis conditions, and the present material model enables the prediction of polyurea blast-mitigation capacity and ballistic resistance, the model offers the potential for the “material-by-design” approach.

Findings

The model is validated by comparing its predictions with the corresponding experimental data.

Originality/value

The work clearly demonstrated that, in order to maximize shock-mitigation effects offered by polyurea, chemistry and processing/synthesis route of this material should be optimized.

Details

Multidiscipline Modeling in Materials and Structures, vol. 9 no. 4
Type: Research Article
ISSN: 1573-6105

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Article
Publication date: 13 November 2009

George K. Stylios

Examines the fifthteenth published year of the ITCRR. Runs the whole gamut of textile innovation, research and testing, some of which investigates hitherto untouched…

Abstract

Examines the fifthteenth published year of the ITCRR. Runs the whole gamut of textile innovation, research and testing, some of which investigates hitherto untouched aspects. Subjects discussed include cotton fabric processing, asbestos substitutes, textile adjuncts to cardiovascular surgery, wet textile processes, hand evaluation, nanotechnology, thermoplastic composites, robotic ironing, protective clothing (agricultural and industrial), ecological aspects of fibre properties – to name but a few! There would appear to be no limit to the future potential for textile applications.

Details

International Journal of Clothing Science and Technology, vol. 21 no. 6
Type: Research Article
ISSN: 0955-6222

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Article
Publication date: 16 November 2010

George K. Stylios

Examines the fifteenth published year of the ITCRR. Runs the whole gamut of textile innovation, research and testing, some of which investigates hitherto untouched…

Abstract

Examines the fifteenth published year of the ITCRR. Runs the whole gamut of textile innovation, research and testing, some of which investigates hitherto untouched aspects. Subjects discussed include cotton fabric processing, asbestos substitutes, textile adjuncts to cardiovascular surgery, wet textile processes, hand evaluation, nanotechnology, thermoplastic composites, robotic ironing, protective clothing (agricultural and industrial), ecological aspects of fibre properties – to name but a few! There would appear to be no limit to the future potential for textile applications.

Details

International Journal of Clothing Science and Technology, vol. 22 no. 6
Type: Research Article
ISSN: 0955-6222

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Article
Publication date: 1 April 1992

JAROSLAV MACKERLE

This bibliography is offered as a practical guide to published papers, conference proceedings papers and theses/dissertations on the finite element (FE) and boundary…

Abstract

This bibliography is offered as a practical guide to published papers, conference proceedings papers and theses/dissertations on the finite element (FE) and boundary element (BE) applications in different fields of biomechanics between 1976 and 1991. The aim of this paper is to help the users of FE and BE techniques to get better value from a large collection of papers on the subjects. Categories in biomechanics included in this survey are: orthopaedic mechanics, dental mechanics, cardiovascular mechanics, soft tissue mechanics, biological flow, impact injury, and other fields of applications. More than 900 references are listed.

Details

Engineering Computations, vol. 9 no. 4
Type: Research Article
ISSN: 0264-4401

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