Unusual features in the nonlinear microwave surface impedance of Y-Ba-Cu-O thin films

Striking features have been found in the nonlinear microwave (8 GHz) surface impedance $Z_s=R_s + jX_s$ of high-quality YBaCuO thin films with comparable low power characteristics [$R_{res}\sim 35--60 \mu\Omega$ and $\lambda_L(15 K)\sim 130--260 nm$]. The surface resistance $R_s$ is found to increase, decrease, or remain independent of the microwave field $H_{rf}$ (up to 60 mT) at different temperatures and for different samples. However, the surface reactance $X_s$ always follows the same functional form. Mechanisms which may be responsible for the observed variations in $R_s$ and $X_s$ are briefly discussed.Comment: 4 pages, 4 figure

Transmission electron microscopy investigation of segregation and critical floating-layer content of indium for island formation in InGaAs

We have investigated InGaAs layers grown by molecular-beam epitaxy on GaAs(001) by transmission electron microscopy (TEM) and photoluminescence spectroscopy. InGaAs layers with In-concentrations of 16, 25 and 28 % and respective thicknesses of 20, 22 and 23 monolayers were deposited at 535 C. The parameters were chosen to grow layers slightly above and below the transition between the two- and three-dimensional growth mode. In-concentration profiles were obtained from high-resolution TEM images by composition evaluation by lattice fringe analysis. The measured profiles can be well described applying the segregation model of Muraki et al. [Appl. Phys. Lett. 61 (1992) 557]. Calculated photoluminescence peak positions on the basis of the measured concentration profiles are in good agreement with the experimental ones. Evaluating experimental In-concentration profiles it is found that the transition from the two-dimensional to the three-dimensional growth mode occurs if the indium content in the In-floating layer exceeds 1.1+/-0.2 monolayers. The measured exponential decrease of the In-concentration within the cap layer on top of the islands reveals that the In-floating layer is not consumed during island formation. The segregation efficiency above the islands is increased compared to the quantum wells which is explained tentatively by strain-dependent lattice-site selection of In. In addition, In0.25Ga0.75As quantum wells were grown at different temperatures between 500 oC and 550 oC. The evaluation of concentration profiles shows that the segregation efficiency increases from R=0.65 to R=0.83.Comment: 16 pages, 6 figures, 1 table, sbmitted in Phys. Rev.

Materializing digital collecting: an extended view of digital materiality

If digital objects are abundant and ubiquitous, why should consumers pay for, much less collect them? The qualities of digital code present numerous challenges for collecting, yet digital collecting can and does occur. We explore the role of companies in constructing digital consumption objects that encourage and support collecting behaviours, identifying material configuration techniques that materialise these objects as elusive and authentic. Such techniques, we argue, may facilitate those pleasures of collecting otherwise absent in the digital realm. We extend theories of collecting by highlighting the role of objects and the companies that construct them in materialising digital collecting. More broadly, we extend theories of digital materiality by highlighting processes of digital material configuration that occur in the pre-objectification phase of materialisation, acknowledging the role of marketing and design in shaping the qualities exhibited by digital consumption objects and consequently related consumption behaviours and experiences

Addicting via hashtags: How is Twitter making addiction?

Persons, substances, bodies, consumption: an ever widening process of ‘‘addicting’’ is underway in Western societies. In this article, we turn our attention to the production of addiction on the microblogging social media platform, Twitter, as an important emerging site in which the addicting of contemporary societies is also occurring. Our analysis explores two questions. First, we investigate the ways in which addiction is enacted via Twitter. How is addiction being made on Twitter? Second, we ask how the technology of Twitter itself is shaping meaning: how do the technological ‘‘affordances’’ of Twitter help constitute the kinds of addiction being materialized? While we find a multiplicity of meanings in the 140-character messages, we also find a pattern: a tendency toward extremes—addiction riven between pain and pleasure. In addition, we find significant areas of commonality between approaches and notable silences around alternatives to common understandings of addiction. We argue that the constraints on communication imposed by Twitter technology afford a ‘‘shorthand’’ of addiction that is both revealing and productive. Illuminated is the importance of addiction as a piece of cultural shorthand that draws on and simultaneously reproduces simplistic, reductive addiction objects. In concluding, we consider what these realities of addiction being enacted through Twitter can tell us about contemporary conditions of possibility for drug use in society and for individual subjectivities and experiences

Exploring Appropriation of Global Cultural Rituals

Adolescents, as a consequence of identification with popular culture, have been described as having homogenous consumption patterns. More recently, however, it has been recognised that ‘glocalisation’ (global practices reworked to fit local contexts) affords an opportunity for differentiation. This paper considers a recent UK phenomenon, namely that of the US high school prom, and seeks to explore the ways in which this ritual has been adopted or adapted as part of youth culture. The method employed here was mixed methods and included in-depth interviews with those who attended a prom in the last three years as well as a questionnaire distributed amongst high school pupils who were anticipating a high school prom. The findings illustrate that the high school prom in the UK is becoming increasingly integrated into the fabric of youth culture although, depending on the agentic abilities employed by the emerging adults in the sample, there is differing appropriation of this ritual event particularly in relation to attitudes towards and motivations for attending the prom. A typology of prom attendees is posited. This paper contributes to our understanding of this practice in a local context

Effects of aprepitant on post-operative nausea and vomiting in patients with congenital heart disease undergoing cardiac surgery or catheterization procedures: a retrospective study with subjects as their own historical control

IntroductionFor patients undergoing cardiac surgery and catheterization procedures, severe post-operative nausea and vomiting (PONV) can occur despite standard anti-emetic interventions. Aprepitant, a neurokinin-1 (NK-1) receptor blocker, is safe and effective at preventing PONV resistant to standard therapies.MethodsPatients with a history of severe PONV presenting for cardiac surgery or catheterization procedures from January 1, 2018 to January 6, 2021 were identified. After pharmacist approval, patients received aprepitant pre-operatively (Dose: 80 mg for weight >50 kg, 40 mg for weight 30–50 kg). A retrospective chart review was performed. Primary outcomes of the incidence of PONV and PONV-related complications were evaluated.ResultsSeventeen patients were included with a mean age of 16.0 years at the time of their initial procedure, which acted as the “control” procedure, and 17.5 years when they received aprepitant. After the control procedure 64.7% of patients required rescue anti-emetics. When this group of patients received aprepitant pre-operatively at their subsequent procedure, only 17.6% required rescue medication (p = 0.005). Similarly, 64.7% of patients suffered at least one PONV-related complication after the control procedure. With aprepitant use pre-operatively, 5.9% of the same patients experienced a PONV-complication (p = 0.0003). Specifically, unplanned ICU admission due to severe PONV after catheterization procedures decreased from 55.6% (5/9) in the control group to 0 after these patients were treated pre-emptively with aprepitant (p = 0.01). For surgical patients, there were significant decreases in PONV-related complications including delayed oral intake and delayed ambulation (p = 0.04) in the aprepitant group compared to the control group.DiscussionThis small, retrospective study supports the conclusion that preoperative aprepitant administration in patients undergoing cardiac catheterization or cardiac surgery with a history of congenital heart disease and severe PONV significantly reduces the incidence of PONV and PONV-related complications. Decreasing these complications will likely improve the surgical experience for patients and families while also decreasing hospital costs and improving efficiency

Understanding consumer demand for new transport technologies and services, and implications for the future of mobility

The transport sector is witnessing unprecedented levels of disruption. Privately owned cars that operate on internal combustion engines have been the dominant modes of passenger transport for much of the last century. However, recent advances in transport technologies and services, such as the development of autonomous vehicles, the emergence of shared mobility services, and the commercialization of alternative fuel vehicle technologies, promise to revolutionise how humans travel. The implications are profound: some have predicted the end of private car dependent Western societies, others have portended greater suburbanization than has ever been observed before. If transport systems are to fulfil current and future needs of different subpopulations, and satisfy short and long-term societal objectives, it is imperative that we comprehend the many factors that shape individual behaviour. This chapter introduces the technologies and services most likely to disrupt prevailing practices in the transport sector. We review past studies that have examined current and future demand for these new technologies and services, and their likely short and long-term impacts on extant mobility patterns. We conclude with a summary of what these new technologies and services might mean for the future of mobility.Comment: 15 pages, 0 figures, book chapte

How Can Consumer Research Contribute to Increased Understanding of Tourist Experiences? A Conceptual Review

Author's accepted version (postprint).This is an Accepted Manuscript of an article published by Taylor & Francis in Scandinavian Journal of Hospitality and Tourism on 24/07/2015, available online: http://wwww.tandfonline.com/10.1080/15022250.2015.1065591