Search results

1 – 10 of over 41000
Book part
Publication date: 1 June 2007

Beth A. Rubin

This chapter draws on recent literature in I/O psychology, management and sociology to posit a relationship between organizational structure and temporal structure and develops…

Abstract

This chapter draws on recent literature in I/O psychology, management and sociology to posit a relationship between organizational structure and temporal structure and develops the construct of layered-task time. Layered-task time is similar to polychronic time (P-time) in the inclusion of simultaneous, multiple tasks but includes additional dimensions of fragmentation, contamination and constraint. The chapter links the development of this new time and its resultant time-sense to variation in the degree to which organizations are hierarchical and centralized and develops propositions about these relationships. The chapter contributes to the growing literature on workplace temporalities in the contemporary economy.

Details

Workplace Temporalities
Type: Book
ISBN: 978-0-7623-1268-9

Article
Publication date: 21 December 2022

Agya Preet, Arunangshu Mukhopadhyay and Vinay Kumar Midha

Sweating is thermo-regulatory behaviour that occurs when a person performs vigorous activity even in cold climatic condition. One of important component of sweat is the presence…

Abstract

Purpose

Sweating is thermo-regulatory behaviour that occurs when a person performs vigorous activity even in cold climatic condition. One of important component of sweat is the presence of lactate. Based on climatic condition, age, gender, maturity and nature of activity level, the change in lactate concentration is inevitable. Hence, the present study is focussed on the impact of change in the lactate concentration on the moisture transmission behaviour through the clothing. The purpose of this paper is to investigate the impact of changing lactate concentration on the moisture vapour transmission behaviour through multi-layered clothing ensembles.

Design/methodology/approach

For the investigation, sweat solution representing male and female sweat were taken for present study. Two different multi-layered ensembles consisting of either spacer or fleece as middle layer were considered. The water vapour permeability and drying rate test were done at standard atmospheric conditions. After testing, ANOVA analysis was done in order to determine the most significant parameters.

Findings

Fabric structure (constituent layers) behaved differently when tested individually and as the layered component with different sweat solutions. Water vapour permeability of sweat solution with higher lactate concentration was lower as compared to sweat solution with lower lactate concentration. Individual layers showed higher rate of vapour permeability with sweat solution containing lower lactate concentration as compared to multi-layered ensembles. Role of PU coated nylon fabric was predominant in case of multi-layered ensembles. Difference in transmission of sweat solution was found higher in case of uni-directional stitched multi-layer spacer ensembles whereas marginal difference was observed in case of bi-directional seamed multi-layer spacer ensemble. Drying rate of sweat containing lower concentration of lactate was higher as compared to the other sweat solution for all the selected fabrics. Density of liquid and amount of the water available for drying influenced the drying behaviour and thus accounted for difference in drying rate of sweat solution differing in the lactate concentration. The contribution percentage of layers, i.e. type of structure was higher (nearly 93–96%) compared to that of solution type (3.3–4.9%) in case of individual layers whereas in the case of the multi-layer ensembles; type of seam had maximum contribution percentage (71–77%) followed by solution type (10–15%). Type of layers had least contribution percentage (nearly 7–9%).

Practical implications

The findings from the study are expected to be realistic and important in designing and development of cold weather garment ensemble for different gender type depending on their activity level especially in case of military personnel and those performing combat activities.

Originality/value

This experimental work based will provide the insight about the behaviour of actual sweat transmission through the layered fabric ensembles and ways to prevent the accumulation of moisture near to human skin surface by manufacturing suitable design structures (in terms of layering composition and seam patterns) per the morphology and requirement of specific consumers.

Details

International Journal of Clothing Science and Technology, vol. 35 no. 2
Type: Research Article
ISSN: 0955-6222

Keywords

Article
Publication date: 1 June 1997

Jaroslav Mackerle

Gives a bibliographical review of the finite element methods (FEMs) applied for the linear and nonlinear, static and dynamic analyses of basic structural elements from the…

6042

Abstract

Gives a bibliographical review of the finite element methods (FEMs) applied for the linear and nonlinear, static and dynamic analyses of basic structural elements from the theoretical as well as practical points of view. The range of applications of FEMs in this area is wide and cannot be presented in a single paper; therefore aims to give the reader an encyclopaedic view on the subject. The bibliography at the end of the paper contains 2,025 references to papers, conference proceedings and theses/dissertations dealing with the analysis of beams, columns, rods, bars, cables, discs, blades, shafts, membranes, plates and shells that were published in 1992‐1995.

Details

Engineering Computations, vol. 14 no. 4
Type: Research Article
ISSN: 0264-4401

Keywords

Article
Publication date: 8 January 2020

Paola Ginestra, Stefano Pandini and Elisabetta Ceretti

The purpose of this paper is to focus on the production of scaffolds with specific morphology and mechanical behavior to satisfy specific requirements regarding their stiffness…

178

Abstract

Purpose

The purpose of this paper is to focus on the production of scaffolds with specific morphology and mechanical behavior to satisfy specific requirements regarding their stiffness, biological interactions and surface structure that can promote cell-cell and cell-matrix interactions though proper porosity, pore size and interconnectivity.

Design/methodology/approach

This case study was focused on the production of multi-layered hybrid scaffolds made of polycaprolactone and consisting in supporting grids obtained by Material Extrusion (ME) alternated with electrospun layers. An open source 3D printer was utilized, with a grain extrusion head that allows the production and distribution of strands on the plate according to the designed geometry. Square grid samples were observed under optical microscope showing a good interconnectivity and spatial distribution of the pores, while scanning electron microscope analysis was used to study the electrospun mats morphology.

Findings

A good adhesion between the ME and electrospinning layers was achieved by compression under specific thermomechanical conditions obtaining a hybrid three-dimensional scaffold. The mechanical performances of the scaffolds have been analyzed by compression tests, and the biological characterization was carried out by seeding two different cells phenotypes on each side of the substrates.

Originality/value

The structure of the multi-layered scaffolds demonstrated to play an important role in promoting cell attachment and proliferation in a 3D culture formation. It is expected that this design will improve the performances of osteochondral scaffolds with a strong influence on the required formation of an interface tissue and structure that need to be rebuilt.

Details

Rapid Prototyping Journal, vol. 26 no. 3
Type: Research Article
ISSN: 1355-2546

Keywords

Article
Publication date: 6 August 2019

Enrique Cuan-Urquizo, Mario Martínez-Magallanes, Saúl E. Crespo-Sánchez, Alfonso Gómez-Espinosa, Oscar Olvera-Silva and Armando Roman-Flores

The purpose of this paper is to study the feasibility of the fabrication of circle arc curved-layered structures via conventional fused deposition modeling (FDM) with three-axis…

Abstract

Purpose

The purpose of this paper is to study the feasibility of the fabrication of circle arc curved-layered structures via conventional fused deposition modeling (FDM) with three-axis machines and to identify the main structural parameters that have an influence on their mechanical properties.

Design/methodology/approach

Customized G-codes were generated via a script developed in MATLAB. The G-codes contain nozzle trajectories with displacements in the three axes simultaneously. Using these, the samples were fabricated with different porosities, and their influence on the mechanical responses evaluated via tensile testing. The load-displacement curves were analyzed to understand the structure-property relationship.

Findings

Circled arc curved-layered structures were successfully fabricated with conventional three-axis FDM machines. The response of these curved lattice structures under tensile loads was mapped to three main stages and deformation mechanisms, namely, straightening, stretching and fracture. The micro-structure formed by the transverse filaments affect the first stage significantly and the other two minimally. The main parameters that affect the structural response were found to be the transverse filaments, as these could behave as hinges, allowing the slide/rotation of adjacent layers and making the structure more shear sensitive.

Research limitations/implications

This paper was restricted to arc-curved samples fabricated with conventional three-axis FDM machines.

Originality/value

The FDM fabrication of curved-structures with controlled porosity and their relation to the resulting mechanical properties is presented here for the first time. The study of curved-lattice structures is of great relevance in various areas, such as biomedical, architecture and aerospace.

Details

Rapid Prototyping Journal, vol. 25 no. 5
Type: Research Article
ISSN: 1355-2546

Keywords

Article
Publication date: 1 March 2000

Prashant Kulkarni, Anne Marsan and Debasish Dutta

Layered manufacturing (LM) is emerging as a new manufacturing technology that can enhance the scope of manufacturing. One of the essential tasks in LM is process planning. This…

7373

Abstract

Layered manufacturing (LM) is emerging as a new manufacturing technology that can enhance the scope of manufacturing. One of the essential tasks in LM is process planning. This paper defines, conceptualizes and reviews the literature in this emerging area. The paper concludes with future projections on the possible directions of research in this area.

Details

Rapid Prototyping Journal, vol. 6 no. 1
Type: Research Article
ISSN: 1355-2546

Keywords

Article
Publication date: 12 November 2010

A. Kumaravel, N. Ganesan and Raju Sethuraman

The purpose of the paper is to investigate the linear thermal buckling and vibration analysis of layered and multiphase magneto‐electro‐elastic (MEE) cylinders made of…

Abstract

Purpose

The purpose of the paper is to investigate the linear thermal buckling and vibration analysis of layered and multiphase magneto‐electro‐elastic (MEE) cylinders made of piezoelectric/piezomagnetic materials using finite element method.

Design/methodology/approach

The constitutive equations of MEE materials are used to derive the finite element equations involving the coupling between mechanical, electrical, magnetic and thermal fields. The present study is limited to clamped‐clamped boundary conditions. The linear thermal buckling is carried out for an axisymmetric cylinder operating in a steady state axisymmetric uniform temperature rise. The influence of stacking sequences and volume fraction of multiphase MEE materials on critical buckling temperature and vibration behaviour is investigated. The influence of coupling effects on critical buckling temperature and vibration behaviour is also studied.

Findings

The critical buckling temperature is higher for MEE axisymmetric cylinder as compared to elastic cylinder.

Originality/value

Linear thermal buckling and vibration analysis of MEE axisymmetric cylinders are studied using the finite element approach. The structure can be used for active vibration control, sensors and actuators. Studying the buckling and vibration behaviour of such structures and influence of coupling effect is extremely useful for the design of magnetoelectroelastic structures.

Details

Multidiscipline Modeling in Materials and Structures, vol. 6 no. 4
Type: Research Article
ISSN: 1573-6105

Keywords

Article
Publication date: 1 June 2000

George K. Chako

Briefly reviews previous literature by the author before presenting an original 12 step system integration protocol designed to ensure the success of companies or countries in…

7259

Abstract

Briefly reviews previous literature by the author before presenting an original 12 step system integration protocol designed to ensure the success of companies or countries in their efforts to develop and market new products. Looks at the issues from different strategic levels such as corporate, international, military and economic. Presents 31 case studies, including the success of Japan in microchips to the failure of Xerox to sell its invention of the Alto personal computer 3 years before Apple: from the success in DNA and Superconductor research to the success of Sunbeam in inventing and marketing food processors: and from the daring invention and production of atomic energy for survival to the successes of sewing machine inventor Howe in co‐operating on patents to compete in markets. Includes 306 questions and answers in order to qualify concepts introduced.

Details

Asia Pacific Journal of Marketing and Logistics, vol. 12 no. 2/3
Type: Research Article
ISSN: 1355-5855

Keywords

Article
Publication date: 26 February 2020

Tomás Dias Sant´Ana, Paulo Henrique de Souza Bermejo, Marina Fiqueiredo Moreira and Wagner Vilas Boas de Souza

The concept of an innovation ecosystem, based on the idea of business ecosystem, has increasingly grown in the literature on strategy, innovation, and entrepreneurship. However…

3821

Abstract

Purpose

The concept of an innovation ecosystem, based on the idea of business ecosystem, has increasingly grown in the literature on strategy, innovation, and entrepreneurship. However, not all innovation ecosystems have the same architectural models or internal collaboration, and existing research rarely deconstructs an ecosystem of innovation and examines its structure. The objective of this article is to systematize the discussion about the structure of an innovation ecosystem and offer a foundation for future research.

Design/methodology/approach

Using the Web of Science database as the source for the articles, this paper presents a systematic review of the literature on the structure of the innovation ecosystems. The period of analysis spanned from January 1993 to August 2019. Two methods, bibliometric analysis and content analysis, were used to structure the systematic review.

Findings

The results of the content analysis showed that the main classifications related to the structure of an innovation ecosystem are the ecosystem life cycle (birth, expansion, leadership, and self-renewal), the classification according to the ecosystem level (macroscopic, medium, and microscopic), and the layered structure (core–periphery structure, triple-layer structure, triple-layer core–periphery structure, and framework 6C). The results also showed that studies in the field are concentrated around a small group of authors, and few studies have discussed the structure of an ecosystem.

Research limitations/implications

This study includes only peer-reviewed articles from the Web of Science database.

Originality/value

This article contributes to innovation ecosystem theory by exploring the characteristics that influence ecosystem structure. In addition to the theoretical contribution, the triple-layer core–periphery framework and the 6C framework set a benchmark for future research on innovation ecosystems.

Details

Management Decision, vol. 58 no. 12
Type: Research Article
ISSN: 0025-1747

Keywords

Article
Publication date: 28 March 2008

Omer Cansizoglu, Ola L.A. Harrysson, Harvey A. West, Denis R. Cormier and Tushar Mahale

Optimization techniques can be used to design geometrically complex components with a wide variety of optimization criteria. However, such components have been very difficult and…

1992

Abstract

Purpose

Optimization techniques can be used to design geometrically complex components with a wide variety of optimization criteria. However, such components have been very difficult and costly to produce. Layered fabrication technologies such as electron beam melting (EBM) open up new possibilities though. This paper seeks to investigate the integration of structural optimization and direct metal fabrication process.

Design/methodology/approach

Mesh structures were designed, and optimization problems were defined to improve structural performance. Finite element analysis code in conjunction with nonlinear optimization routines were used in MATLAB. Element data were extracted from an STL‐file, and output structures from the optimization routine were manufactured using an EBM machine. Original and optimized structures were tested and compared.

Findings

There were discrepancies between the performance of the theoretical structures and the physical EBM structures due to the layered fabrication approach. A scaling factor was developed to account for the effect of layering on the material properties.

Practical implications

Structural optimization can be used to improve the performance of a design, and direct fabrication technologies can be used to realise these structures. However, designers must realize that fabricated structures are not identical to idealized CAD structures, hence material properties much be adjusted accordingly.

Originality/value

Integration of structural optimization and direct metal fabrication was reported in the paper. It shows the process from design through manufacturing with integrated analysis.

Details

Rapid Prototyping Journal, vol. 14 no. 2
Type: Research Article
ISSN: 1355-2546

Keywords

1 – 10 of over 41000