Seishiro Matsubara, Kenjiro Tarada, Takaya Kobayashi, Toshiyuki Saitou, Manabu Umeda, Yasuko Mihara, Kai Oide, Hiroto Shin and Yasuhiro Katsuda
The purpose of this paper is to propose a set of constitutive functions for dried bodies for accurate prediction of the entire deformation process of ceramic products during…
Abstract
Purpose
The purpose of this paper is to propose a set of constitutive functions for dried bodies for accurate prediction of the entire deformation process of ceramic products during firing and to present relevant methods for determining their coefficients from a series of respective thermo-mechanical analysis (TMA) tests.
Design/methodology/approach
The function forms of the sintering-induced strain rate, viscoplastic multiplier and elastic modulus are formulated in order with reference to empirical data of relative densities. Separate TMA tests are conducted to identify their coefficients, while a stairway thermal cycle test is carried out to identify the parameters in the densification rate. Then, various finite element analyses (FEA) are performed for accuracy confirmation.
Findings
The performances of the present constitutive functions along with the identified material parameters were validated in comparison with the relevant test results. It has then been confirmed that these functions enable us to some extent to accurately estimate the non-mechanical and mechanical deformations of dried bodies during firing. Also, by performing FEA of an actual sanitary ware product, the applicability and capability of the proposed set of constitutive functions could be demonstrated.
Practical implications
The present methodology with the proposed constitutive functions is a simple, but reliable and practical approach for simulating the deformation process of arbitrary ceramic products subjected to firing and applicable for practical applications in various engineering fields.
Originality/value
The constitutive functions of the viscoplastic multiplier and elastic modulus, which enable us to properly characterize the mechanical behavior of dried bodies subjected to firing, are originally formulated in analogy with that of the sintering-induced strain.
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The Lockheed scandal was exposed during the 4 February 1976 hearings of the Sub-Committee on Multinational Corporations of the United States Senate Committee on Foreign Relations…
Abstract
The Lockheed scandal was exposed during the 4 February 1976 hearings of the Sub-Committee on Multinational Corporations of the United States Senate Committee on Foreign Relations. These hearings revealed that Lockheed Aircraft Corporation paid illegal payments in several countries including Japan to promote the sale of its planes to prevent bankruptcy. The Securities Exchange Commission obtained documents showing that Lockheed paid more than US$10 million to Yoshio Kodama, a “fixer” and Lockheed's secret representative, and the Marubeni Corporation, which was Lockheed's agent in Japan since 1959. During the same hearings on 6 February, A. Carl Kotchian, vice president of Lockheed, informed the committee that a senior Japanese government official received US$2 million from Marubeni and that his company relied on Kenji Osano, a close associate of former Prime Minister Kakuei Tanaka, as an intermediary in its efforts to sell 21 Lockheed's L-1001 Tristar airbuses to All Nippon Airways (ANA) (Macdougall, 1988, pp. 193–195).
Can B. Kalayci and Surendra M. Gupta
Disturbing increase in the use of virgin resources to produce new products has threatened the environment. Many countries have reacted to this situation through regulations which…
Abstract
Disturbing increase in the use of virgin resources to produce new products has threatened the environment. Many countries have reacted to this situation through regulations which aim to eliminate negative impact of products on the environment shaping the concept of environmentally conscious manufacturing and product recovery (ECMPRO). The first crucial and the most time-consuming step of product recovery is disassembly. The best productivity rate is achieved via a disassembly line in an automated disassembly process. In this chapter, we consider a sequence-dependent disassembly line balancing problem (SDDLBP) with multiple objectives that is concerned with the assignment of disassembly tasks to a set of ordered disassembly workstations while satisfying the disassembly precedence constraints and optimizing the effectiveness of several measures considering sequence-dependent time increments among disassembly tasks. Due to the high complexity of the SDDLBP, there is currently no known way to optimally solve even moderately sized instances of the problem. Therefore, an efficient methodology based on the simulated annealing (SA) is proposed to solve the SDDLBP. Case scenarios are considered and comparisons with ant colony optimization (ACO), particle swarm optimization (PSO), river formation dynamics (RFD), and tabu search (TS) approaches are provided to demonstrate the superior functionality of the proposed algorithm.
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Patrik Ström and Brita Hermelin
The circular economy (CE) has been endorsed as representing a model that is able to achieve environmental protection through decreased use of raw materials, together with changing…
Abstract
Purpose
The circular economy (CE) has been endorsed as representing a model that is able to achieve environmental protection through decreased use of raw materials, together with changing economic values and social inclusion thanks to its demand for a wide variety of skill profiles. This has motivated many policy initiatives to support the implementation of the CE. The purpose of this study is to follow such policy initiatives in three geographically anchored industry-specific networks.
Design/methodology/approach
The study contributes to the research debate on the CE through a spatial approach with a focus on how the implementation of the CE is conditioned by spatial and regional contexts. The authors investigate three different networks in Sweden for CE with different locations and industrial profiles.
Findings
The findings reveal the difficulty that exist in relation to the implementation of the CE. The network and support functions in combination with private industry are vital. The risk of sustaining an uneven regional economic development is evident.
Originality/value
Although research on the development of the CE has proliferated, geographical approaches to this development are comparably rare to date. The authors seek to contextualise the strategy development and policy implementation of a CE policy.
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Nataraj Chandrasekharan, Jaehyung Ju and Lonny Thompson
A three-dimensional finite element (FE) model is developed to design a vibrating bimorph piezoelectric cantilever beam with lead zirconate titanate (PZT-5H) for energy harvesting…
Abstract
Purpose
A three-dimensional finite element (FE) model is developed to design a vibrating bimorph piezoelectric cantilever beam with lead zirconate titanate (PZT-5H) for energy harvesting. The paper aims to discuss these issues.
Design/methodology/approach
A parametric study of electric power generated as a function of the dielectric constant, transverse piezoelectric strain constant, length and thickness of the piezoelectric material, is conducted for a time-harmonic surface pressure load. Transversely isotropic elastic and piezoelectric properties are assigned to the bimorph layers with brass chosen as the substrate material in the three-dimensional FE model. Using design of experiments, a study was conducted to determine the sensitivity of power with respect to the geometric and material variables.
Findings
The numerical analysis shows that a uniform decrease in thickness and length coverage of the piezoelectric layers results in a nonlinear reduction in power amplitude, which suggests optimal values. The piezoelectric strain coefficient, d31 and the thickness of PZT-5H, tp, are the most important design parameters to generate high electric energy for bimorph vibration harvesting device.
Originality/value
The work demonstrates that, through a sensitivity analysis, the electro-mechanical piezoelectric coupling coefficient (d31) and the thickness of the piezoelectric strips (tp) are the most important parameters which have a significant effect on power harvested.
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P. Glynne‐Jones and N.M. White
A range of self‐power technologies is reviewed. Self‐powered systems are defined as those that operate by harnessing ambient energy present within the environment of the system…
Abstract
A range of self‐power technologies is reviewed. Self‐powered systems are defined as those that operate by harnessing ambient energy present within the environment of the system. As MEMS and smart‐material technologies mature, embedded and remote systems become more attractive. Self‐power offers a potential for solving the difficult problem of supplying energy to these devices.
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Seyed Mohammad Arab, Seyed Reza Hosseini Zeidabadi, Seyed Ahmad Jenabali Jahromi, Habib Daneshmanesh, Seyed Mojtaba Zebarjad and Kamal Janghorban
A self-lubricant surface composite including Al matrix and Babbitt alloy 11 reinforcement has been fabricated via friction stir processing (FSP).
Abstract
Purpose
A self-lubricant surface composite including Al matrix and Babbitt alloy 11 reinforcement has been fabricated via friction stir processing (FSP).
Design/methodology/approach
The optimum processing condition is estimated by statistical analysis of a L9 Taguchi design of experiment. The results of Taguchi analysis suggested four passes of FSP, traverse speed of 40 mm/min and rotational speeds of 1,250 rpm as the optimum parameters to achieve higher hardness and wear resistance.
Findings
The needle-shaped particles are fragmented into the finer particles after FSP. There is uniform distribution of precipitations after FSP. The microhardness of manufactured surface bearings has been increased. Finer particles, smaller grains and in situ formed intermetallic precipitations (AlSb) can be responsible for hardness enhancement. Wear resistance of base metal also has been remarkably enhanced after FSP.
Originality/value
The originality of this paper lies in the following: new self-lubricating surface composite; a tough and resistant to wear sheets; and using a solid-state method to fabricate a surface bearing.
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Fatma Nazli Sari, Mehmet Baki Karamis and Yahya Kaya
The paper aims to clarify the hybrid Mg alloy composites reinforced with multi-walled carbon nanotube (MWCNT) and Cerium (Ce) rare earth element tribological properties were…
Abstract
Purpose
The paper aims to clarify the hybrid Mg alloy composites reinforced with multi-walled carbon nanotube (MWCNT) and Cerium (Ce) rare earth element tribological properties were investigated by using pin-on-disk test configuration under dry and lubricated sliding conditions.
Design/methodology/approach
The paper opted for an experimental study with composite samples under lubricated conditions. Their tribological properties were investigated by using pin-on-disk test configuration under dry and lubricated sliding conditions. Wear tests were carried out at 20°C temperature. Wear behavior of Mg alloy composites was evaluated as maximum coefficient of friction and the variation of the maximum frictional forces of the samples.
Findings
The reinforcements such as Ce and MWCNT have a decreasing effect between 100 and 200 rpm speed tests for friction coefficient and friction force of Mg alloy. The microstructure has an important effect on the wear mechanism. There can be both adhesive and abrasive wear mechanism for the same composite at different sliding speeds. It is determined that there is no systematic relationship between reinforcement percent and sliding speed related to wear behavior of AZ 41 matrix composites reinforced with CNT and Ce. The results indicate that different wear mechanisms occur at different sliding speeds. The sliding speed has effect on both an increment and decrement for wear.
Research limitations/implications
Because of the chosen research approach, the research results may lack generalizability. Therefore, researchers are encouraged to test the different reinforced composite samples further.
Practical implications
The paper includes implications for the development of a hybrid composite reinforced with rare earth elements and MWCNT.
Originality/value
This paper fulfils an identified need to study a hybrid composite reinforced with rare earth elements and MWCNT.
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Helge Wurdemann, Vahid Aminzadeh, Jian S. Dai, John Reed and Graham Purnell
This paper aims to introduce and identify a new 3D handling operation (bin picking) for natural discrete food products using food categorisation.
Abstract
Purpose
This paper aims to introduce and identify a new 3D handling operation (bin picking) for natural discrete food products using food categorisation.
Design/methodology/approach
The research shows a new food categorisation and the relation between food ordering processes and food categories. Bin picking in the food industry needs more flexible vision software compared to the manufacturing industry in order to decrease the degree of disarray of food products and transfer them into structure.
Findings
It has been shown that there are still manual operated ordering processes in food industry such as bin picking; it just needs new ideas of image processing algorithms such as active shape models (ASMs) on its development in order to recognise the highly varying shapes of food products.
Research limitations/implications
This research was aimed at locating a new ordering process and proving a new principle, but for practical implementation this bin picking solution needs to be developed and tested further.
Originality/value
Identifying new ordering processes via food categorisation is unique and applying ASMs to bin picking opens a new industrial sector (food industry) for 3D handling.