Shape optimization of pressurized air bearings

Use of externally pressurized air bearings allows for the design of mechanical systems requiring extreme precision in positioning. One application is the fine control for the positioning of mirrors in large-scale optical telescopes. Other examples come from applications in robotics and computer hard-drive manufacturing. Pressurized bearings maintain a finite separation between mechanical components by virtue of the presence of a pressurized flow of air through the gap between the components. An everyday example is an air hockey table, where a puck is levitated above the table by an array of vertical jets of air. Using pressurized bearings there is no contact between “moving parts” and hence there is no friction and no wear of sensitive components. This workshop project is focused on the problem of designing optimal static air bearings subject to given engineering constraints. Recent numerical computations of this problem, done at IBM by Robert and Hendriks, suggest that near-optimal designs can have unexpected complicated and intricate structures. We will use analytical approaches to shed some light on this situation and to offer some guides for the design process. In Section 2 the design problem is stated and formulated as an optimization problem for an elliptic boundary value problem. In Section 3 the general problem is specialized to bearings with rectangular bases. Section 4 addresses the solutions of this problem that can be obtained using variational formulations of the problem. Analysis showing the sensitive dependence to perturbations (in numerical computations or manufacturing constraints) of near-optimal designs is given in Section 5. In Section 6, a restricted class of “groove network” designs motivated by the original results of Robert and Hendriks is examined. Finally, in Section 7, we consider the design problem for circular axisymmetric air bearings

Determinants of voluntary international financial reporting standards adoption in Poland

The paper examines the determinants of voluntary International Financial Reporting Standards (IFRS) adoption in Poland. In doing so, it empirically confirms the impact of diverse CEO and supervisory board characteristics on voluntary IFRS adoption. The paper focuses on 446 publicly traded production companies from Poland. The analysis is based on logistic regression analysis. The empirical investigation confirms the impact on voluntary IFRS adoption of such factors as company size, international investors, international supervisory board, number of supervisory board members, CEO nationality. The paper contributes to the assessment of voluntary IFRS adoption determinants, by presenting for the first time CEO and supervisory board characteristics and their impact on voluntary International Financial Reporting Standards (IFRS) adoption, and the determinants of IFRS adoption from Central and Eastern Europe. The paper enhances existing knowledge of voluntary IFRS adoption by incorporating new CEO and supervisory board characteristics, thus closing a gap in the relevant literature. The results of the paper are significant from the supervisor’s perspective, the quality of financial statements and the effectiveness of corporate governance systems

Where spirituality and religion meet gender and sexuality::Towards a research agenda for intersectional marketing theory

During a roundtable discussion at the 2022 GENMAC Conference, a group of researchers specializing in religiosity and spiritual consumption, using examples from their own fieldwork, reflected on how (i) researchers’ subject positioning—including their gender and sexuality—shape fieldwork in multifaceted manners; (ii) investigations of religious/spiritual fields would benefit from a heightened sensitivity to issues of gender and sexuality; and (iii) greater sensitivity to aspects of religion and/or spirituality can help gender and sexuality scholars better understand consumers and markets. Based on the above, in this commentary paper, we call for intersectional reflexivity, attention to vulnerability and discomfort during fieldwork, and critical sensitivity to the religious “context of context” during theorization. Furthermore, we argue that specific spiritual/religious imaginaries can foster new research approaches that can contribute to more nuanced fieldwork and theorization in marketing and consumer research.</p

Practice effects on the modified Concept Shifting Task (mCST): A convenient assessment for treatment effects on prefrontal cognitive function

<p>Abstract</p> <p>Background</p> <p>Trail-making tests, such as the Concept Shifting Task (CST), can be used to test the effects of treatment on cognitive performance over time in various neuropsychological disorders. However, cognitive performance in such experimental designs might improve as a result of the practice obtained during repeated testing rather than the treatment itself. The current study investigated if practice affects the accuracy and duration of performance on the repeatedly administered Concept Shifting Task modified to make it resistant to practice (mCST). The mCST was administered to 54 healthy participants twice a day, before and after a short break, for eight days. Results. The ANOVA and meta-analysis showed that there was no improvement in the mCST accuracy on the last vs. the first trial (Hedges' <it>g </it>= .14, <it>p </it>= .221) or within the session (after vs. before the break on all days; <it>g </it>= .01, <it>p </it>= .922). However, the participants performed the task faster on the last vs. the first trial (<it>g </it>= -.75, <it>p </it>< .001) and after vs. before the break on all days (<it>g </it>= -.12, <it>p </it>= .002). Conclusions. Repeated administration of the mCST does not affect the accuracy of performance on the test. However, practice might contribute to faster performance on the mCST over time and within each session.</p

A Discourse Analysis of Pilgrimage Reviews

This paper is the first to provide an account of the discursive features of online consumer reviews of pilgrimage sites. Drawing from pilgrimage studies and narrativity theory in consumer research, we explore how consumers communicate the spiritual and material aspects of pilgrimage experiences by examining a corpus of 833 consumer reviews on TripAdvisor of the most sacred pilgrimage sites of the world’s major five faith groups. Pilgrims include analytical discursive features to communicate the material aspect of their consumption experience. They reserve narration for spiritual transformation and the experience of strong emotions. Moreover, review ratings are only reflective of the spiritual aspect of their consumption experience. As such, our research complements previous studies by highlighting the material, physical aspect of this extraordinary consumption experience

Nanocellulose as a natural source for groundbreaking applications in materials science: Todays state

Nanocelluloses are natural materials with at least one dimension in the nano-scale. They combine important cellulose properties with the features of nanomaterials and open new horizons for materials science and its applications. The field of nanocellulose materials is subdivided into three domains: biotechnologically produced bacterial nanocellulose hydrogels, mechanically delaminated cellulose nanofibers, and hydrolytically extracted cellulose nanocrystals. This review article describes todays state regarding the production, structural details, physicochemical properties, and innovative applications of these nanocelluloses. Promising technical applications including gels/foams, thickeners/stabilizers as well as reinforcing agents have been proposed and research from last five years indicates new potential for groundbreaking innovations in the areas of cosmetic products, wound dressings, drug carriers, medical implants, tissue engineering, food and composites. The current state of worldwide commercialization and the challenge of reducing nanocellulose production costs are also discussed.Dana Kralisch and Dagmar Fischer gratefully acknowledge the Free State of Thuringia and the European Social Fund (2016 FGR 0045) for funding. Dagmar Fischer would like to thank Yvette Pötzinger and Berit Karl for the excellent editorial support. Dieter Klemm, Friederike Kramer and Katrin Petzold-Welcke are grateful for the support by the Federal Ministry of Economic Affairs and Energy, ZIM (KF2748903MF4 and KF2386003MF3). Thanks are due to the employees of Jenpolymer Materials Ltd. & Co. KG and the Polymet Jena Association, especially Priv.-Doz. Dr. Wolfgang Fried, and Prof. Dr. Raimund W. Kinne, Experimental Rheumatology Unit, Department of Orthopedics, Jena University Hospital, Germany as well as to Dr. Detlef Gorski and Elke Langhammer, SuraChemicals GmbH, Jena, Germany for effective and helpful cooperation and stimulating interaction. Dieter Klemm and Friederike Kramer would like to thank Katharina Horn for the excellent editorial support. Miguel Gama acknowledges the funding from QREN (“Quadro de Referência Estratégica Nacional”) through the BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020-Programa Operacional Regional do Norte. Tom Lindström acknowledges RISE Bioeconomy for support and permission to publish. Emily Cranston and Stephanie Kedzior are thankful for funding from the Natural Sciences and Engineering Research Council of Canada (NSERC) in the form of a Discovery Grant (RGPIN 402329) and PGSD graduate student scholarship, as well as support from the Faculty of Engineering at McMaster University.info:eu-repo/semantics/publishedVersio

It takes a community to conceive: an analysis of the scope, nature and accuracy of online sources of health information for couples trying to conceive

This study examined the nature and accuracy of information available across online platforms for couples trying to conceive. A consumer simulation-based investigation of English websites and social media (Facebook, Twitter, Instagram) was undertaken using common search terms identified in a pilot study. Claims about fertility and pregnancy health were then extracted from the results and analysed thematically. The accuracy of each claim was assessed independently by six fertility and conception experts, rated on a scale of 1 (not factual) to 4 (highly factual), with scores collated to produce a median rating. Claims with a medianscoreb3 were classified as inaccurate. The use of the terms 'trying to conceive' and '#TTC' were common identifiers on online platforms. Claims were extracted predominantly from websites (n= 89) rather than social media, with Twitter and Instagram comprising commercial elements and Facebook focused on community-based support. Thematic analysis revealed three major themes among the claims across all platforms: conception behaviour and monitoring, lifestyle and exposures, and medical. Fact-checking by the experts revealed that 40% of the information assessed was inaccurate, and that inaccuracies were more likely to be present in the conception behaviour and monitoring advice, the topics most amenable to modification. Since online information is a readily accessible and commonly utilized resource, there is opportunity for improved dissemination of evidence-based material to reach interested couples. Further cross-disciplinary and consumer-based research, such as a user survey, is required to understand how best to provide the 'trying to conceive' community with accurate information.Sophie G.E. Kedzior, Tina Bianco-Miotto, James Breen, Kerrilyn R. Diener, Martin Donnelley, Kylie R. Dunning Megan A.S. Penno, John E. Schjenken, David J. Sharkey, Nicolette A. Hodyl, Tod Fullston, Maria Gardiner, Hannah M. Brown, Alice R. Rumbol