262 research outputs found

    Sliding and abrasive wear behaviour of HVOF- and HVAF-sprayed Cr3C2-NiCr hardmetal coatings

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    This paper provides a comprehensive characterisation of HVOF- and HVAF-sprayed Cr3C2-25 wt.% NiCr hardmetal coatings. One commercial powder composition with two different particle size distributions was processed using five HVOF and HVAF thermal spray systems. All coatings contain less Cr3C2 than the feedstock powder, possibly due to the rebound of some Cr3C2-rich particles during high-velocity impact onto the substrate. Dry sand-rubber wheel abrasive wear testing causes both grooving and pull-out of splat fragments. Mass losses depend on inter- and intra-lamellar cohesion, being higher (≥70 mg after a wear distance of 5904 m) for the coatings deposited with the coarser feedstock powder or with one type of HVAF torch. Sliding wear at room temperature against alumina involves shallower abrasive grooving, small-scale delamination and carbide pull-outs, and it is controlled by intra-lamellar cohesion. The coatings obtained from the fine feedstock powder exhibit the lowest wear rates (≈5×10-6 mm3/(Nm)). At 400 °C, abrasive grooving dominates the sliding wear behaviour; wear rates increase by one order of magnitude but friction coefficients decrease from ≈0.7 to ≈0.5. The thermal expansion coefficient of the coatings (11.08×10-6 °C-1 in the 30-400 °C range) is sufficiently close to that of the steel substrate (14.23×10-6 °C-1) to avoid macro-cracking

    Management of duodenal stump fistula after gastrectomy for malignant disease: A systematic review of the literature

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    Background: Duodenal stump fistula (DSF) remains one of the most serious complications following subtotal or total gastrectomy, as it endangers patient's life. DSF is related to high mortality (16-20%) and morbidity (75%) rates. DSF-related morbidity always leads to longer hospitalization times due to medical and surgical complications such as wound infections, intra-abdominal abscesses, intra-abdominal bleeding, acute pancreatitis, acute cholecystitis, severe malnutrition, fluids and electrolytes disorders, diffuse peritonitis, and pneumonia. Our systematic review aimed at improving our understanding of such surgical complication, focusing on nonsurgical and surgical DSF management in patients undergoing gastric resection for gastric cancer. Methods: We performed a systematic literature review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyzes (PRISMA) guidelines. PubMed/MEDLINE, EMBASE, Scopus, Cochrane Library and Web of Science databases were used to search all related literature. Results: The 20 included articles covered an approximately 40 years-study period (1979-2017), with a total 294 patient population. DSF diagnosis occurred between the fifth and tenth postoperative day. Main DSF-related complications were sepsis, abdominal abscess, wound infection, pneumonia, and intra-abdominal bleeding. DSF treatment was divided into four categories: conservative (101 cases), endoscopic (4 cases), percutaneous (82 cases), and surgical (157 cases). Length of hospitalization was 21-39 days, ranging from 1 to 1035 days. Healing time was 19-63 days, ranging from 1 to 1035 days. DSF-related mortality rate recorded 18.7%. Conclusions: DSF is a rare but potentially lethal complication after gastrectomy for gastric cancer. Early DSF diagnosis is crucial in reducing DSF-related morbidity and mortality. Conservative and/or endoscopic/percutaneous treatments is/are the first choice. However, if the patient clinical condition worsens, surgery becomes mandatory and duodenostomy appears to be the most effective surgical procedure

    Tribology of HVOF- and HVAF-sprayed WC-10Co4Cr hardmetal coatings: A comparative assessment

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    This paper provides a comprehensive assessment of the sliding and abrasive wear behaviour of WC-10Co4Cr hardmetal coatings, representative of the existing state-of-the-art. A commercial feedstock powder with two different particle size distributions was sprayed onto carbon steel substrates using two HVOF and two HVAF spray processes. Mild wear rates of <10-7mm3/(Nm) and friction coefficients of 480.5 were obtained for all samples in ball-on-disk sliding wear tests at room temperature against Al2O3 counterparts. WC-10Co4Cr coatings definitely outperform a reference electrolytic hard chromium coating under these test conditions. Their wear mechanisms include extrusion and removal of the binder matrix, with the formation of a wavy surface morphology, and brittle cracking. The balance of such phenomena is closely related to intra-lamellar features, and rather independent of those properties (e.g. indentation fracture toughness, elastic modulus) which mainly reflect large-scale inter-lamellar cohesion, as quantitatively confirmed by a principal component analysis. Intra-lamellar dissolution of WC into the matrix indeed increases the incidence of brittle cracking, resulting in slightly higher wear rates. At 400\ub0C, some of the hardmetal coatings fail because of the superposition between tensile residual stresses and thermal expansion mismatch stresses (due to the difference between the thermal expansion coefficients of the steel substrate and of the hardmetal coating). Those which do not fail, on account of lower residual stresses, exhibit higher wear rates than at room temperature, due to oxidation of the WC grains.The resistance of the coatings against abrasive wear, assessed by dry sand-rubber wheel testing, is related to inter-lamellar cohesion, as proven by a principal component analysis of the collected dataset. Therefore, coatings deposited from coarse feedstock powders suffer higher wear loss than those obtained from fine powders, as brittle inter-lamellar detachment is caused by their weaker interparticle cohesion, witnessed by their systematically lower fracture toughness as well

    'From mosh pit to posh pit': Festival imagery in the context of the boutique festival

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    This paper addresses market-based cultural production in the context of the UK festival field, with a focus on the framing of the festival experience through anticipation. In particular, boutique festivals are discussed as examples of a contemporary cultural ?product category? which has emerged and proliferated in the last decade. Through discourse analysis of media representations of boutique festivals, we situate the boutique festival in a broader sociocultural discourse of agency and choice, which makes it meaningful and desirable, and outline the type of consumer it is meant to attract. For the contemporary consumer, the boutique festival is presented as an anticipated experience based on countercultural festival imagery, while simultaneously framing cultural participation through consumption. The paper contributes to a wider debate on the construction of the consumer in the cultural economy

    Driven to excess? Linking calling, character and the (mis)behaviour of marketers

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    We are presently at a point of unique circumstantial convergence where recession, an increased emphasis on business ethics, and marketer’s reluctance to accept shifting social agendas have combined to identify the need for a new approach to marketing. Using concepts from the human resources, marketing and psychology literatures, and especially Erich Fromm’s ideas concerning economic character, this paper posits that marketers – as a professional community – are driven to promote consumerist outcomes; victims of an automaton amalgam of calling and character. The analysis suggests the vulnerability of both marketer and consumer are mutually reinforcing and that we need, somehow, to break this damaging cycle of dependence. We know little, however, about how marketers think and feel about their discipline, so this paper also promotes an agenda for marketer behaviour research, as a countervailing balance to a currently disproportionate focus on the consumer

    Mobile Money: Communication, Consumption and Change in the Payments Space

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    This article explores the emerging field of 'mobile money': mobile phone-enabled systems for value transfer and storage, primarily in the developing world, which are heralded as signal interventions in the effort to broaden financial inclusion and bank the 'unbanked.' Focusing on the stories that circulate in the emergent network of expertise that is calling 'mobile money' into being, it discusses how economic techniques and social narratives about markets - specifically, narratives about the opportunities for profit and financial inclusion in the 'payments space' - format a consumer market for mobile money. Furthermore, it asks whether end-users' repurposing of mobile money - and the use of airtime as currency - heralds a new means of exchange or store of value, potentially remaking money in the process. © 2012 Copyright Taylor and Francis Group, LLC

    Not Quite Right: Representations of Eastern Europeans in ECJ Discourse

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    Although the increasing responsiveness of the Court of Justice of the European Union (the ‘ECJ’) jurisprudence to western Member States’ concerns regarding Central and Eastern European (‘CEE’) nationals’ mobility has garnered academic attention, ECJ discourse has not been scrutinised for how it approaches the CEE region or CEE movers. Applying postcolonial theory, this article seeks to fill this gap and to explore whether there are any indications that ECJ discourse is in line with the historical western-centric inferiorisation of the CEE region. A critical discourse analysis of a set of ECJ judgments and corresponding Advocate General opinions pertaining to CEE nationals illustrates not only how the ECJ adopts numerous discursive strategies to maintain its authority, but also how it tends to prioritise values of the western Member States, while overlooking interests of CEE movers. Its one-sided approach is further reinforced by referring to irrelevant facts and negative assumptions to create an image of CEE nationals as socially and economically inferior to westerners, as not belonging to the proper EU polity and as not quite deserving of EU law’s protections. By silencing CEE nationals’ voices, while disregarding the background of east/west socio-economic and political power differentials and precariousness experienced by many CEE workers in the west, such racialising discourse normalises ethnicity- and class-based stereotypes. These findings also help to contextualise both EU and western policies targeting CEE movers and evidence of their unequal outcomes in the west, and are in line with today’s nuanced expressions of racisms. By illustrating the ECJ’s role in addressing values pertinent to mobile CEE individuals, this study facilitates a fuller appreciation of the ECJ’s power in shaping and reflecting western-centric EU identity and policies. Engaging with such issues will not only allow us to better appreciate—and question—the ECJ’s legitimacy, but might also facilitate a better understanding of power dynamics within the EU. This study also makes significant theoretical and methodological contributions. It expands (and complicates) the application of postcolonial theory to contemporary intra-EU processes, while illustrating the usefulness of applying critical discourse analysis to exploring differentiation, exclusion, subordination and power within legal language
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