863 research outputs found

    A low-numerical dissipation, patch-based adaptive-mesh-refinement method for large-eddy simulation of compressible flows

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    This paper describes a hybrid finite-difference method for the large-eddy simulation of compressible flows with low-numerical dissipation and structured adaptive mesh refinement (SAMR). A conservative flux-based approach is described with an explicit centered scheme used in turbulent flow regions while a weighted essentially non-oscillatory (WENO) scheme is employed to capture shocks. Three-dimensional numerical simulations of a Richtmyer-Meshkov instability are presented

    Shock-resolved Navier–Stokes simulation of the Richtmyer–Meshkov instability start-up at a light–heavy interface

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    The single-mode Richtmyer–Meshkov instability is investigated using a first-order perturbation of the two-dimensional Navier–Stokes equations about a one-dimensional unsteady shock-resolved base flow. A feature-tracking local refinement scheme is used to fully resolve the viscous internal structure of the shock. This method captures perturbations on the shocks and their influence on the interface growth throughout the simulation, to accurately examine the start-up and early linear growth phases of the instability. Results are compared to analytic models of the instability, showing some agreement with predicted asymptotic growth rates towards the inviscid limit, but significant discrepancies are noted in the transient growth phase. Viscous effects are found to be inadequately predicted by existing models

    Synthetic cathinones related fatalities: an update

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    Synthetic cathinones, more commonly known as "bath salts", are synthetic drugs chemically related to cathinone, a psychostimulant found in the khat plant. They are the first most consumed products among new psychoactive substances, which cause psychostimulant and hallucinogenic effects determining a number of fatalities worldwide.  In this paper, we have systematically reviewed cases of synthetic cathinones-related fatalities analytically confirmed, which have occurred in the last few years.OBJECTIVE: Synthetic cathinones, more commonly known as “bath salts”, are synthetic drugs chemically related to cathinone, a psychostimulant found in the khat plant. They are the first most consumed products among new psychoactive substances, which cause psychostimulant and hallucinogenic effects determining a number of fatalities worldwide. In this paper, we have systematically reviewed cases of synthetic cathinones-related fatalities analytically confirmed, which have occurred in the last few years. MATERIALS AND METHODS: Relevant scientific articles were identified in Medline, Cochrane Central, Scopus, Web of Science and Institutional/ government websites up to November 2017 using the following keywords: synthetic cathinones, mephedrone, methylenedioxypyrovalerone, MDPV, methylone, ethylone, buthylone, fatal intoxication, fatalities and death. RESULTS: In total, 20 citations met the criteria for inclusion, representing several fatal cases with analytically confirmed synthetic cathinones in biological sample/s of the deceased. The death was attributed to hyperthermia, hypertension, cardiac arrest and more in general to the classic serotonin syndrome. Only rarely did the concentration of the parent drug causing fatality overcome the value of 1 mg/L in post-mortem biological fluids. CONCLUSIONS: Abuse of synthetic cathinones still represents a serious public health issue. Systematic clinical studies on both the animal and human model are lacking; therefore, the only available data are from the users who experience the possible hazardous consequences. Analytical methodologies for the identification of parent compounds and eventual metabolites both in ante-mortem and post-mortem cases need to be developed and validated. Analytical data should be shared through different communication platforms with the aim of stopping this serious health threat for drug users

    To what extent luxury retailing can be smart?

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    The aim of this paper is to explore how luxury brands use new technologies in the context of smart retailing. Building on qualitative data from multiple cases from the luxury industry, our analysis reveals that this sector is conscious of the benefits of using smart technologies as marketing tools, while the effective use of these innovative systems is still limited. However, studies on innovation forces affecting the retail industry are still limited in luxury sectors. The study provides an empirical contribution to the emerging topic of smart retailing with an emphasis on the luxury sector through its in-depth investigation of the usage of smart technologies by the firms studied

    Inclusive or exclusive? Investigating how retail technology can reduce old consumers’ barriers to shopping

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    This paper investigates older consumers in-store shopping experiences and the barriers that they face. The aim is to understand how new retail technologies (e.g., interactive in-store displays, self-service tills, robots etc.) can help seniors access satisfying, autonomous retail experiences, helping them to achieve a sense of inclusion in physical retail settings. Drawing upon the social inclusion/exclusion theory and information overload theory, the research employs a qualitative approach based on an inductive design, including face-to-face semi structured interviews with 36 consumers aged 75+. The findings highlight (i) old consumers have scarce interactions with in-store technologies (adding knowledge to motivations literature), (ii) the need to develop new technologies to support these consumers, and (iii) the extent to which these technologies are excluding rather than including old consumers (adding knowledge to the drivers of the field of exclusion). Results provide guidelines for retailers to enhance the sense of inclusion for old consumers through a better usage of new technologies

    The use of new technologies for corporate marketing communication in luxury retailing: preliminary findings

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    The aim of this paper is to explore the extent to which luxury brand retailers employ new technologies as a tool for corporate marketing communication. We employed a multiple-case study consisting of five information-rich cases, with the similar characteristics of large firms selling luxury brands which are aware of the importance of innovation. In each company, we interviewed the key person in charge of marketing innovation strategies, and we collected data from annual reports, press releases, and direct observation of all the new technology categories used. Our findings reveal that this sector is considerably aware of the benefits of using new media as a marketing communication tool, while the effective use of these new media is still limited. The study provides an empirical contribution to the emerging topic of innovation and technology management in retailing, with the emphasis being placed on the luxury sector through an in-depth investigation of the usage of new technologies by the firms studied. This study is the first one investigating thoroughly the luxury sector usage of new technologies to improve corporate marketing communication

    Fractoluminescence characterization of the energy dissipated during fast fracture of glass

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    Fractoluminescence experiments are performed on two kinds of silicate glasses. All the light spectra collected during dynamic fracture reveal a black body radiator behaviour, which is interpreted as a crack velocity-dependent temperature rise close to the crack tip. Crack velocities are estimated to be of the order of 1300 m.s1^{-1} and fracture process zones are shown to extend over a few nanometers.Comment: Accepted for publication in Europhysics Letters; 5 pages; 4 figure

    Short-Facelift Approach in Temporal Artery Biopsy: Is It Safe?

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    Giant cell arteritis (GCA) is a quite common panarteritis of the elderly that affects medium- and large-size arteries. Despite the increasing role of imaging with advancing technology, the gold standard for the diagnosis of GCA is still the temporal artery biopsy. A described complication of superficial temporal artery biopsy (STAB), for which incidence is not clear, is the accidental damage of the frontal branch of the facial nerve. In this paper, we described the short-scar facelift surgical approach for STAB on 23 consecutive patients who underwent unilateral superficial temporal artery biopsy for GCA suspicion. We collected data in terms of postoperative complications, biopsy specimen length, biopsy result and cosmetic appearance of the scar. In our experience, this surgical approach combines the advantage of avoiding incisions within the dangerous anatomical area, minimizing the risk of facial nerve damage, with an acceptable complication rate and a good final aesthetic result which avoids visible scarring
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