83 research outputs found

    Development of CO2 snow cleaning for in situ cleaning of µCMM stylus tips

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    Contamination adhered to the surface of a µCMM stylus tip compromises the measurement accuracy of the µCMM system, potentially causing dimensional errors that are over ten times larger than the uncertainty of a modern µCMM. In prior work by the authors, the use of a high pressure CO2 gas stream was demonstrated to achieve significant cleaning rate for a range of contaminant without damage to the stylus tip surface. This paper explores the practical challenges of achieving effective stylus tip cleaning in situ on µCMM systems. Two types of snow cleaning approaches were evaluated for their coverage of cleaning, thermal impact and gas flow forces. This work then presents a novel multi-nozzle prototype system using pulsed snow streams to achieve cleaning coverage over the entire stylus tip, and balances forces from the snow streams reducing drag force imparted by the gas stream to levels comparable to the probing force of µCMMs, as well as allowing automated cleaning procedure integrated into a µCMM system

    Soluble Abrasives for Waterjet Machining

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    This is an Accepted Manuscript of an article published by Taylor & Francis on 14th Aug 2014, available online: http://dx.doi.org/10.1080/10426914.2014.930949.© 2014 Taylor & Francis Group, LLC. The addition of hard abrasives to the jet in waterjet machining can improve machining rate, however, embedding of particles in machined surfaces is a limitation, which results in reduced fatigue life, and limits the application of well adhered subsequent coatings to the surface. In this study, softer soluble abrasives were investigated as a potential solution. Soluble abrasives yielded a higher material removal rate compared to plain waterjet, although were not as effective as traditional hard abrasives. Soluble abrasives reduced grit embedment on all four workpiece materials. A post-machining surface cleaning operation demonstrated that any remaining soluble abrasive could be removed

    The Anti-social Behaviour, Crime and Policing Act 2014: implications for sex workers and their clients

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    © 2015 Taylor & Francis. The Anti-social Behaviour, Crime and Policing Act 2014 introduced new powers to deal with behaviour deemed to be ‘anti-social’. In this paper we consider how the new law could be used against sex workers and their clients and the impact this may have. Although the new powers were not intentionally designed to respond to prostitution, we suggest that they will be utilised to tackle it. We argue that the law will be used inconsistently in a way which will go directly against policy which seeks to ‘tackle demand’ and take a less punitive approach to dealing with sex workers. Despite a policy shift to see sex workers more as victims and less as offenders, we draw on existing evidence to demonstrate that the new anti-social behaviour order law will be utilised to exclude street sex workers from public spaces. We claim that a degree of ‘policy re-fraction’ will occur when the new laws are implemented by practitioners

    Digital technology and governance in transition: The case of the British Library

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    Comment on the organizational consequences of the new information and communications technologies (ICTs) is pervaded by a powerful imagery of disaggregation and a tendency for ?virtual? forms of production to be seen as synonymous with the ?end? of bureaucracy. This paper questions the underlying assumptions of the ?virtual organization?, highlighting the historically enduring, diversified character of the bureaucratic form. The paper then presents case study findings on the web-based access to information resources now being provided by the British Library (BL). The case study evidence produces two main findings. First, radically decentralised virtual forms of service delivery are heavily dependent on new forms of capacity-building and information aggregation. Second, digital technology is embedded in an inherently contested and contradictory context of institutional change. Current developments in the management and control of digital rights are consistent with the commodification of the public sphere. However, the evidence also suggests that scholarly access to information resources is being significantly influenced by the ?information society? objectives of the BL and other institutional players within the network of UK research libraries

    The social nature of serial murder: The intersection of gender and modernity

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    The literature on the aetiology of serial killing has benefited from analyses which offer an alternative perspective to individual/psychological approaches and consider serial murder as a sociological phenomenon. The main argument brought to bear within this body of work identifies the socio-economic and cultural conditions of modernity as enabling and legitimating the motivations and actions of the serial killer. This article interrogates this work from the standpoint of a gendered reading of modernity. Using the Yorkshire Ripper case, it emphasizes how in addition to the political economy, gender relations and masculinity shape the dynamics of serial murder and its representation

    Chinese students in a UK business school: hearing the student voice in reflective teaching and learning practice.

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    This paper presents the outcomes of a study carried out in 2001-2002 with nine postgraduate students from China, enrolled on taught master's programmes in a UK university business school. The aims of the research were to explore the development of the students' orientations to learning during their year of study in the UK, and to explore how the researcher's interactions with the study group contributed to her professional reflections and influenced her academic practice. The main conclusions of the project were that participants' underlying approaches to learning did not change substantially over the year, owing to the culturally implicit nature of UK academic conventions and that they experienced high levels of emotional isolation and loneliness, which affected their academic confidence

    Revisiting the Yorkshire Ripper Murders: Interrogating Gender Violence, Sex Work, and Justice

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    Between 1975 and 1980, 13 women, 7 of whom were sex workers, were murdered in the North of England. Aside from the femicide itself, the case was infamous for police failings, misogyny, and victim blaming. The article begins with a discussion of the serial murder of women as a gendered structural phenomenon within the wider context of violence, gender, and arbitrary justice. In support of this, the article revisits the above case to interrogate police reform in England and Wales in the wake of the murders, arguing that despite procedural reform, gendered cultural practices continue to shape justice outcomes for victims of gender violence. In addition, changes to prostitution policy are assessed to highlight how the historical and ongoing Othering and criminalization of street sex workers perpetuates the victimization of this marginalized group of women

    Fetal cyclophosphamide exposure induces testicular cancer and reduced spermatogenesis and ovarian follicle numbers in mice

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    <div><p>Exposure to radiation during fetal development induces testicular germ cell tumors (TGCT) and reduces spermatogenesis in mice. However, whether DNA damaging chemotherapeutic agents elicit these effects in mice remains unclear. Among such agents, cyclophosphamide (CP) is currently used to treat breast cancer in pregnant women, and the effects of fetal exposure to this drug manifested in the offspring must be better understood to offer such patients suitable counseling. The present study was designed to determine whether fetal exposure to CP induces testicular cancer and/or gonadal toxicity in 129 and in 129.MOLF congenic (L1) mice. Exposure to CP on embryonic days 10.5 and 11.5 dramatically increased TGCT incidence to 28% in offspring of 129 mice (control value, 2%) and to 80% in the male offspring of L1 (control value 33%). These increases are similar to those observed in both lines of mice by radiation. <i>In utero</i> exposure to CP also significantly reduced testis weights at 4 weeks of age to ∼70% of control and induced atrophic seminiferous tubules in ∼30% of the testes. When the <i>in utero</i> CP-exposed 129 mice reached adulthood, there were significant reductions in testicular and epididymal sperm counts to 62% and 70%, respectively, of controls. In female offspring, CP caused the loss of 77% of primordial follicles and increased follicle growth activation. The results indicate that i) DNA damage is a common mechanism leading to induction of testicular cancer, ii) increased induction of testis cancer by external agents is proportional to the spontaneous incidence due to inherent genetic susceptibility, and iii) children exposed to radiation or DNA damaging chemotherapeutic agents <i>in utero</i> may have increased risks of developing testis cancer and having reduced spermatogenic potential or diminished reproductive lifespan.</p></div

    A Developmental Stage-Specific Switch from DAZL to BOLL Occurs during Fetal Oogenesis in Humans, but Not Mice

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    The Deleted in Azoospermia gene family encodes three germ cell-specific RNA-binding proteins (DAZ, DAZL and BOLL) that are essential for gametogenesis in diverse species. Targeted disruption of Boll in mice causes male-specific spermiogenic defects, but females are apparently fertile. Overexpression of human BOLL promotes the derivation of germ cell-like cells from genetically female (XX), but not male (XY) human ES cells however, suggesting a functional role for BOLL in regulating female gametogenesis in humans. Whether BOLL is expressed during oogenesis in mammals also remains unclear. We have therefore investigated the expression of BOLL during fetal oogenesis in humans and mice. We demonstrate that BOLL protein is expressed in the germ cells of the human fetal ovary, at a later developmental stage than, and almost mutually-exclusive to, the expression of DAZL. Strikingly, BOLL is downregulated, and DAZL re-expressed, as primordial follicles form, revealing BOLL expression to be restricted to a narrow window during fetal oogenesis. By quantifying the extent of co-expression of DAZL and BOLL with markers of meiosis, we show that this window likely corresponds to the later stages of meiotic prophase I. Finally, we demonstrate that Boll is also transiently expressed during oogenesis in the fetal mouse ovary, but is simultaneously co-expressed within the same germ cells as Dazl. These data reveal significant similarities and differences between the expression of BOLL homologues during oogenesis in humans and mice, and raise questions as to the validity of the Boll(-/-) mouse as a model for understanding BOLL function during human oogenesis

    Fabrication of a Smart Suspension Structure of Micro Tactile Probing

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    AbstractIn micro tactile probing a design trade off must be made between stiff and robust probes. Stiff probes are capable of overcoming surface attraction forces, while delicate flexible probes are capable of making contact with a sensitive part without causing damage. To address this need for both flexible and stiff sensors a novel micro tactile probe has been proposed that makes use of an active suspension structure to modulate probe stiffness as required. In this paper we focus on the initial manufacturing process development of such a sensor. While initial design concepts were created with high precision machining techniques in mind, these are shown to have some fundamental limitations with respect to this specific application. Therefore a design for manufacture strategy was adopted and the structure of the initial design was modified such that it may be manufactured using a chemical etching based process. This paper presents the process followed to successfully adapt an initial sensor design for a chemical etching based manufacturing. Surface 3D microscopy was used to analyse the resulting structure, to demonstrate a significant improvement in device flatness. In addition Finite Element Analysis (COMSOL) was used to estimate the vertical and torsional frequency for the suspension structure which is compared with experimental measurements using a laser vibrometer to show good agreement
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