15 resultados para Overseas
em Cambridge University Engineering Department Publications Database
Resumo:
Purpose - The purpose of this paper is to develop a framework of total acquisition cost of overseas outsourcing/sourcing in manufacturing industry. This framework contains categorized cost items that may occur during the overseas outsourcing/sourcing process. The framework was tested by a case study to establish both its feasibility and usability. Design/methodology/approach - First, interviews were carried out with practitioners who have the experience of overseas outsourcing/sourcing in order to obtain inputs from industry. The framework was then built up based on combined inputs from literature and from practitioners. Finally, the framework was tested by a case study in a multinational high-tech manufacturer to establish both its feasibility and usability. Findings - A practical barrier for implementing this framework is shortage of information. The predictability of the cost items in the framework varies. How to deal with the trade off between accuracy and applicability is a problem needed to be solved in the future research. Originality/value - There are always limitations to the generalizations that can be made from just one case. However, despite these limitations, this case study is believed to have shown the general requirement of modeling the uncertainty and dealing with the dilemma between accuracy and applicability in practice. © Emerald Group Publishing Limited.
Resumo:
The objective of this study was to compare the life-cycle environmental impacts of changed production structures for two consumer goods (high-density polyethylene (HDPE) shopping bags and beds) in Jamaica. A scenario technique was used to construct three alternative production structures for each product; each scenario reflecting an increase in local production in Jamaica which depended on an increased supply of input materials which may be sourced: (1) externally from overseas suppliers, (2) from post-consumer recycling, and (3) locally on the island of Jamaica. These three constructed scenarios were then compared to the existing supply chain or reference scenarios of the products. The results showed that for both case products the recycling scenario was most preferable for localising production, resulting in the lowest environmental impact. This was because the production of raw materials accounted for the largest effect on total environmental impact. As such, the most immediate environmental improvements were realised by lowering the production of virgin materials. © 2007 Elsevier Ltd. All rights reserved.
Resumo:
The twist elastic constant, K2, and the rotational viscosity coefficient, γ1, are of importance when the response lime for the in-plane switching mode is studied. Since adding dopants is one technique to improve the response characteristics, the effect of dopants on these physical properties is significant. The effect on K2 and γ1 of adding alkyl(alkoxy) phenylcyclopentenones and alkyl(alkoxy) cyanobiphenyls to the base mixture ZLI-4792 together with their temperature dependence have been investigated using different temperature scales. The reduced temperature scale showed the effect of these dopants on K2 is small. On the other hand, the temperature dependence of γ1 depends on both the absolute temperature scale and the reduced temperature scale. Therefore, it is clear that the choice of temperature scale with which to compare γ1 for different systems raises fundamental questions which way not have a unique answer. 2000 OPA (Overseas Publishers Association) N.V. Published by license under the Gordon and Breach Science Publishers imprint.
Resumo:
The flexoelectric behaviour of a hypertwisted chiral nematic bimesogenic liquid crystal is presented. Through detailed electro-optic measurements, with particular emphasis on the switching properties, we demonstrate remarkably high optical axis tilt angles. The material studied possessed a room temperature nematic phase and aligned easily on cooling under the application of a moderate electric field. Switching times of the order of 500 μs and contrast ratios of 90:1 are readily achieved. The tilt angles, measured using the rotating analyser technique, were found to be practically temperature independent and linear with the applied field. Tilt angles of 22.5° were obtained with moderate applied fields of 9.4 V/μm whilst fields of 25 V/μm yielded tilt angles of 45°. We believe these are the highest tilt angles ever recorded for such fields. © 2001 OPA (Overseas Publishers Association) N.V. Published by license under the Gordon and Breach Science Publishers imprint, a member of the Taylor & Francis Group.
Resumo:
In order to develop materials that exhibit enhanced flexoelectric switching in the chiral nematic phase we have identified mesogenic units that display inherently strong flexoelectric coupling capabilities. Here we examine the oxycyanobiphenyl (OCB) moiety: homologues from the nOCB series exhibit significant electro-optic switching effects when doped with a highly chiral additive. Here we have examined lower dielectric anisotropy materials, since they allow the flexoelectric response to be extended to high field amplitudes. We show that dielectric coupling strength can be low in symmetric bimesogenic molecules. The flexoelectric response of such a molecular structure is tested by doping a homologue from the series CBOnOCB with a chiral additive: very significantly we find that the optic axis is rotated through 2φ=45° in <50 μs on reversing the polarity of the field (amplitude E=±6 V μm-1). Subsequently we have synthesized room temperature chiral nematic materials that exhibit 2φ≥90° at E≈10 V μm-1. © 2001 OPA (Overseas Publishers Association) N.V. Published by license under the Gordon and Breach Science Publishers imprint, a member of the Taylor & Francis Group.
Resumo:
The photoisomerisation of a flexoelectric chiral nematic bimesogen system dyed with an azo dye has been investigated. The host material has a pitch and field dependent tilt angle that are temperature independent. Upon illumination by ultra violet, the azo dye molecules undergo a shape change from their trans to cis isomer. The effect of the shape change of the dye on the mixture is to decrease the I-N* transition temperatures, to increase the response times and to decrease the transmitted optical intensity. For the same reduced temperatures, the tilt angles, pitch and threshold voltages for the transition from focal conic to homeotropic textures are unchanged. The macroscopic parameters observed suggest that the orientational order parameter of the system is reduced by UV illumination. The cis isomers do not appear to separate from the host material or significantly change the flexoelectric coefficient. © 2001 OPA (Overseas Publishers Association) N.V. Published by license under the Gordon and Breach Science Publishers imprint, a member of the Taylor & Francis Group.
Resumo:
In a chiral nematic liquid crystal, the flexoelectric effect consists of a fast and linear coupling with an applied electric field. One difficulty to overcome is the unwinding of the helix that occurs at higher fields due to dielectric coupling. The use of bimesogens, which possess very low molecular dielectric anisotropy can improve flexoelectric characteristics. New bimesogen compounds have recently been synthesised that exhibit switching angles of 45° for applied fields of about 9 V.μm-1. In this paper, results from dielectric, electro-optic and dynamic light scattering measurements are reported for the new bimesogenic mixture. The dielectric anisotropy Δε changes sign with temperature and its values range between -0.2 and 0.3 for the temperature range studied. For Δε weakly positive, no electric field Freedericksz transition could be induced but Williams domains are observed instead. The large decrease in the bend elastic constant to viscosity coefficient ratio is attributed to a large increase in the bend viscosity coefficient. © 2001 OPA (Overseas Publishers Association) N.V. Published by license under the Gordon and Breach Science Publishers imprint, a member of the Taylor & Francis Group.
Resumo:
New 2-arylidene-p-menthane-3-ones containing the ether bridging group in the arylidene fragment have been synthesized and studied as chiral dopants in ferroelectric liquid crystal mixtures. The ferroelectric properties of these compositions were compared with those for compositions including chiral dopants that do not contain any bridging group. The influence of bridging group and terminal alkyl substituent length in the dopant molecule on the ferroelectric parameters of systems studied is discussed. © 2001 OPA (Overseas Publishers Association) N.V. Published by license under the Gordon and Breach Science Publishers imprint, a member of the Taylor & Francis Group,.
Resumo:
We present a study on a series of dye guest-host mixtures using fluorescent perylene-based molecules as the guest dye in an organosiloxane host. These hosts have temperature-independent switching, at room temperature, through 90° for fields of the order of 10 Vrms/μm. Perylene molecules have been grafted onto the organosiloxane moiety via an alkyl spacer producing novel and rugged fluorescent dyes that are readily miscible in the host. Micro-separation of the low molar mass siloxane groups in the mesophases tend to form smectic phases. These planes produce an effective two-dimensional polymer backbonethat engenders the rugged mechanical properties of polymeric liquid crystals onto these low molar mass ferroelectric liquid crystals. In this study we show how the introduction of the dye molecules affects the electro-optic properties of the organosiloxane host. © 2001 OPA (Overseas Publishers Association) N.V. Published by license under the Gordon and Breach Science Publishers imprint, a member of the Taylor & Francis Group,.
Resumo:
Deciding which technology to invest in is a recurring issue for technology managers, and the ability to successfully identify the right technology can be a make or break decision for a company. The effects of globalisation have made this issue even more imperative. Not only do companies have to be competitive by global standards but increasingly they have to source technological capabilities from overseas as well. Technology managers already have a variety of decision aids to draw upon, including valuation tools, for example DCF and real options; decision trees; and technology roadmapping. However little theory exists on when, where, why or even how to best apply particular decision aids. Rather than developing further techniques, this paper reviews the relevance and limitations of existing techniques. This is drawn from an on going research project which seeks to support technology managers in selecting and applying existing decision aids and potentially in the design of future decision aids. It is intended that through improving the selection of decision aids, decision performance can be increased, leading to more effective allocation of resources and hence competitive advantage. (c) 2006 PICMET.
Resumo:
Purpose - This paper compares CSR strategy, stakeholder engagement and overseas approaches of six leading companies which have large potential environmental and social impacts, influential stakeholders and notable CSR actions. Design/methodology/approach - It is an exploratory survey based on interviews of senior executives from British and Brazilian companies operating in the steel, petroleum and retail sectors and makes comparisons between and within them. Findings - British companies interviewed are more rule-based, adopt an implicit CSR approach; react to stakeholder’s demands based on moral motives and focus on environmental issues. The Brazilian companies, reviewed in this study, adopt an explicit CSR approach, have relational motives to engage with stakeholders and are more concerned with building a responsible image and narrowing social gaps. Research limitations/implications - The survey is based on perceptions of senior executives interviewed which may or may not correspond to actual practices. The sample size restricts generalization of results and specific firms interviewed may not represent the prevailing CSR business strategy in their respective countries. Practical implications - British companies can learn from the Brazilian experience how to become more innovative in a broader approach to CSR. Brazil should reinforce its legal framework to provide a more systematic and rule-based approach to CSR close to the UK experience. Originality/value - The way CSR is conceived and implemented depends on the ethical, socioeconomic, legal and institutional environment of the country in which the firm operates