36,990 research outputs found

    Isolating LCDs at end-of-life using active disassembly technology: A feasibility study

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    The European Union draft Waste Electrical and Electronic Equipment (WEEE) directive calls for the removal and separate treatment of liquid crystal displays (LCD). This aspect of the legislation will potentially have an important impact upon the future `End of Life' (EoL) processing of much WEEE. Active Disassembly using Smart Materials (ADSM) has been proven to have applicability in self-dismantling, nondestructive and rapid disassembly of small electronic products. This paper investigates the technical feasibility of removing LCD screens from IT communication products using ASDM technology. In this paper an option is suggested to cleanly separate LCD screens from printed circuit boards, utilizing an LCD bracket made from `shape memory polymer'. The case study products employed are Nokia Japanese J-Phones. Demonstration experiments with initial results are presented, and future developments discussed. SMB glass transformation temperatures (Tg) and time efficiency in disassembly are considered

    Extra-gonadal germ cell tumour – what about the testis!

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    Extra-gonadal germ cell tumours (EGGCT) are rare. Therefore further investigations of the testis is aimed at sourcing a possible primary origin of gonadal tumour. Over the years, various case series on EGGCT have been reported questioning its true nature as in a majority of them, a primary source is found in the testis, thus representing a metastatic gonadal tumour. The testis pathology could be either a true germ cell foci, an intra-tubular epithelial neoplasia or an area of fibrosis, indicating a „burnt out tumour‟. We report a 39-year-old male who underwent laparotomy and excision of a retroperitoneal tumour. Histopathological examination revealed retroperitoneal lymph node of mixed germ cell tumour origin. Clinical and ultrasound examination of bilateral testis was normal. The patient refused orchidectomy or a testicular biopsy. He underwent four cycles of bleomycin, cisplatin, and etoposide with no evidence of tumour recurrence on follow up and remains disease free after 12 months of diagnosis. A literature review of EGGCT, its relation and factors relating with future testicular tumour is presented

    Capturing emotions: experience sampling at live music events

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    Purpose – Using techniques developed mainly in subjective well-being and “happiness” studies, the purpose of this paper is to discuss the applicability of these and related methods for understanding and evaluating the emotional responses experienced within the live music event environment. Design/methodology/approach – The concept of “experience” is debated and set within the context of music events designed to create a specific type of emotional experience for the attendees. The main tools for researching experiences over a time period are considered focusing on the “experience sampling method” (ESM) (Csikszentmihalyi, 1997) and the “day reconstruction method” (Kahneman et al., 2004). These methods are critiqued in terms of their usefulness and practicality as research tools in the study of audience emotions. Findings – A revised method was then developed and a small-scale trial undertaken at a live music event, the results of which are presented and discussed. A conceptual model illustrating the interconnectedness of experience is introduced as an example of the application of the data gathered through this method to theory development. The paper concludes by reflecting on both the methodological appropriateness and practicality of ESMs as a way of gathering valuable data on the emotions engendered by events. Research limitations/implications – An obstacle yet to be overcome is using this data to predict attitudinal and behavioural change related to arts marketing goals. However, studies in other areas have clearly shown that emotional response is a significant indicator of future behaviour suggesting that the potential is there. Practical implications – The trialled method provides a useful starting point for better understanding the complexity of emotional effects triggered at live music events. Originality/value – The paper concludes that an adaptation of these methods has the potential to provide much needed rich and credible data on the feelings and emotional reactions triggered by different elements of a live event

    Gene doctoring: a method for recombineering in laboratory and pathogenic Escherichia coli strains

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    Background: Homologous recombination mediated by the lambda-Red genes is a common method for making chromosomal modifications in Escherichia coli. Several protocols have been developed that differ in the mechanisms by which DNA, carrying regions homologous to the chromosome, are delivered into the cell. A common technique is to electroporate linear DNA fragments into cells. Alternatively, DNA fragments are generated in vivo by digestion of a donor plasmid with a nuclease that does not cleave the host genome. In both cases the lambda-Red gene products recombine homologous regions carried on the linear DNA fragments with the chromosome. We have successfully used both techniques to generate chromosomal mutations in E. coli K-12 strains. However, we have had limited success with these lambda-Red based recombination techniques in pathogenic E. coli strains, which has led us to develop an enhanced protocol for recombineering in such strains. \ud \ud Results: Our goal was to develop a high-throughput recombineering system, primarily for the coupling of genes to epitope tags, which could also be used for deletion of genes in both pathogenic and K-12 E. coli strains. To that end we have designed a series of donor plasmids for use with the lambda-Red recombination system, which when cleaved in vivo by the I-SceI meganuclease generate a discrete linear DNA fragment, allowing for C-terminal tagging of chromosomal genes with a 6xHis, 3xFLAG, 4xProteinA or GFP tag or for the deletion of chromosomal regions. We have enhanced existing protocols and technologies by inclusion of a cassette conferring kanamycin resistance and, crucially, by including the sacB gene on the donor plasmid, so that all but true recombinants are counter-selected on kanamycin and sucrose containing media, thus eliminating the need for extensive screening. This method has the added advantage of limiting the exposure of cells to the potential damaging effects of the lambda-Red system, which can lead to unwanted secondary alterations to the chromosome. \ud \ud Conclusion: We have developed a counter-selective recombineering technique for epitope tagging or for deleting genes in E. coli. We have demonstrated the versatility of the technique by modifying the chromosome of the enterohaemorrhagic O157:H7 (EHEC), uropathogenic CFT073 (UPEC), enteroaggregative O42 (EAEC) and enterotoxigenic H10407 (ETEC) E. coli strains as well as in K-12 laboratory strains

    Polarization-insensitive electroabsorptive modulation using interdiffused InGaAs(P)-InP quantum wells

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    This is a theoretical study to demonstrate the use of interdiffusion in the realization of polarization insensitivity at the band-edge. Two InGaAs-InP quantum well as-grown structures have been investigated: one with lattice-matched condition and the other with small as-grown tensile strain (0.15%). The interdiffusion is considered to take place on the Group V (As and P) sublattice only. As a result, a tensile strain is produced which merges the heavy- and light-hole states in order to achieve polarization insensitivity. Criteria to develop polarization-insensitive quantum wells (QW's) using interdiffusion are presented here. When the two-phase interdiffusion mechanism is modeled, the results show that the well barrier interfaces of the QW maintain an abrupt profile while the well width remains constant after interdiffusion. The two interdiffused QW structures considered here can produce polarization insensitive electroabsorption at operation wavelengths around 1.55 ÎĽm. The one with lattice-matched condition is particularly attractive since it only requires an easy (high-yield) fabrication process with a simple postprocessing thermal annealing to achieve polarization insensitivity.published_or_final_versio

    Band gap engineering in simultaneous phononic and photonic crystal slabs

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    We discuss the simultaneous existence of phononic and photonic band gaps in two types of phononic crystals slabs, namely periodic arrays of nanoholes in a Si membrane and of Si nanodots on a SiO2 membrane. In the former geometry, we investigate in detail both the boron nitride lattice and the square lattice with two atoms per unit cell (these include the square, triangular and honeycomb lattices as particular cases). In the latter geometry, some preliminary results are reported for a square lattice

    The optical properties of InGaAs(P)/InP under group V sublattice two-phase interdiffusion

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    Using the fundamental transition state, we will investigate the two phase interdiffusion of group V sublattice in a strained lattice matched InGaAs/InP quantum well (QW) structures. The model employs three parameters namely the diffusion coefficients in the barrier (Db)and in the well (Dw)and the concentration ratio (k) of the diffused species at the heterstructure. The QW model includes the effects of strain and the exciton. A pseudo time dependent calculation is also considered and results are fitted to the reported experimental data. These parameters which characterize the diffusion mechanism can be measure to form a better understanding of the interdiffsion process for group V sublattice.published_or_final_versio
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