Optimising durability of PTFE seals — mix and geometry — a good match

The use of PTFE and PTFE compounds as materials for seals provides additional security in terms of durability, friction, robustness and product design. Success is achieved by optimally matching the sealing material with the counter-rotational surface.     

Female involvement in fatal crashes: increasingly riskier or increasingly exposed?

Men have long held the lead in motor-vehicle crashes. However, recent research from a variety of countries indicates that women are closing the gap. The relative increase in females involved in crashes has been associated with an increase in crash exposure. But is it simply that there are more women driving that is causing this increase? Or are there other mediating factors? The main goal of this research effort was to shed some light on this controversy. We found evidence that most of the observed increase in female drivers' fatalities was due to a parallel increase in female driving exposure but that some groups of female drivers (mainly underage female drivers) have become more vulnerable to some risk-taking driving behaviors than others.     

EU-EAEU dilemma of Armenia: Does science support politics?

Scientometrics - On January 1, 2015, the Republic of Armenia joined the (Russian-led) Eurasian Economic Union (EAEU) and actually refrained from entering into the alternative Association Agreement...     

Theory of constraints: is it a theory and a good one?

In this study, we attempted to advance the academic dialogue towards establishing TOC as a formal operations management theory, so it can continue improving practice. We link the component parts of the TOC and map the theoretical arrangement to the consensual definitional components and properties of a theory. Also, we examine whether TOC satisfy the virtues of a good theory (uniqueness, parsimony, conservation, generalisability, fecundity, internal consistency, empirical riskiness, and abstraction). Consequently, a practical outcome of our study stems from demonstrating the utility of the goodness criteria as a useful instrument for examining future theories in the field of operations. From a practitioner's standpoint, by establishing a strong theoretical foundation for TOC, we assist managers deploying it to gain better understanding of TOC elements and ultimately avoid implementation failures. Also, we increase the credibility of TOC in the eyes of senior executives. The study concludes by sketching new avenues for future research that have industrial relevance for successful TOC implementation efforts.     

Antisemitism and Islamophobia: what does a bibliometric study reveal?

Although Islamophobia and Antisemitism are two phenomena different in their nature, both represent a form of Otherness that entails a complicated inclusion into multi-ethnic societies of modern Europe and the United States. The purpose of the present study is to show how the research literature has portrayed both phenomena in terms of bibliometric data retrieved from the SCIE Clarivate Analytics database. In addition, we were interested to find out if there is a literature that connects Islamophobia and Antisemitism, its direction and influence. Our findings show that because publications and citations on Islamophobia are relatively new, the research in terms of publications draws the attention of academic society in the direction of research of Antisemitism, but the citations count of the literature on Islamophobia exceeds by far that of the literature on Antisemitism. Moreover, we found that although Antisemitism and Islamophobia are distinct trends, there is an interaction between the literatures that discuss both, and the research that combines the analysis of both phenomena gains more influence than research dedicated to each phenomenon separately.     

Injuries and Safe Communities Accreditation: Is there a link?

Safe Communities (SC) is a global movement that brings together community stakeholders to collaboratively address injury concerns. SC accreditation is a formal process through which communities are recognized for strengthening local injury prevention capacity. Six million Americans live in 25 SC sites, but no research has been done to understand the model’s potential impact on this population. This study explored the temporal relationship between SC accreditation and injury trends in three SC sites from the state of Illinois—Arlington Heights, Itasca, and New Lenox. Hospitalization data, including patient demographics, exposure information, injury outcomes, and economic variables, were obtained from a statewide hospital discharge database for a 12-year period (1999–2011). Joinpoint regression models were fitted to identify any periods of significant change, examine the direction of the injury trend, and to estimate monthly percent changes in injury counts and rates. Poisson random-intercept regression measured the average total change since the official SC accreditation for the three communities combined and compared them to three matched control sites. In joinpoint regression, one of the SC sites showed a 10-year increase in hospitalization cases and rates followed by a two-year decline, and the trend reversal occurred while the community was pursuing the SC accreditation. Injury hospitalizations decreased after accreditation compared to the pre-accreditation period when SC sites were compared to their control counterparts using Poisson modeling. Our findings suggest that the SC model may be a promising approach to reduce injuries. Further research is warranted to replicate these findings in other communities.     

Collaboration networks and collaboration tools: a match for SMEs?

Global patterns of industrial production have resulted in relocation of industrial operations groups in an effort to create new markets for mass and customised mass production. The collaborative effort between these dispersed teams increases the likelihood of combining ideas and knowledge in novel ways. Internet technologies enable these virtual collaboration networks to seamlessly engage in discussions that demonstrate a richness of perspectives when it comes to problem-solving and innovative idea-exchange. Indeed, knowledge creation and harnessing collective knowledge are salient features of collaborative networks (CNs) and this is witnessed by a new interest in these entities. However, small and medium enterprises (SMEs) display a difficulty in partnering and collaborating in global networks, especially since their technological infrastructure may be lacking. Given the widespread adoption of collaborative technologies in social contexts, this research seeks to examine how such informal interactions are facilitated in SMEs through Web 2.0 tools. Specifically, this paper seeks to contribute to existing literature by examining how Web 2.0 affects the collaborative effort in two SME CNs; this study demonstrated that the collaboration effort is amplified when Web 2.0 tools are available. Other parameters such as trust in other members’ ability; perception of usefulness; and enhancement of collective knowledge are seen as supporting the CN mutuality. In addition, it brings together the three diverse research areas of collaborative networks, internet collaborative tools and psychological barriers and enablers.     

Surreal Encounters: Science,Surrealism and the Re‐Circulation of a Crime‐Scene Photograph

This article examines the implications of the surrealist appropriation and re‐circulation of a crime‐scene photograph depicting the body of Mary Kelly, Jack the Ripper's final victim. The article traces the trajectory of the photograph, taken in 1888, as it shifts from its role as a visual police record in London, to evidence of sexual sadism in the developing field of criminology in France, before finally becoming an object in the text of a play, ‘Regards sur l'enfer anthropoclasique’, by surrealist Maurice Heine, and being published in 1936 along with that play in Minotaure, a luxury art review. As it is re‐framed in various contexts, however, the photograph retains some of its prior meaning. A key point in the argument is that this kind of appropriation reveals how photographic meaning is produced and anchored.     

Science studies and natural sciences: Which is primary,distribution or interdependence between variables?

It is shown that in natural sciences, interdependences between variables are determined regardless of the distributions of variable values, whereas in science studies, distributions should be used as a starting point. This difference is due the nature of measuring instruments: in natural sciences, measurements are performed with the use of devices, while science of science uses human devices adapting themselves to the measured objects. Practical inferences are drawn.     

Vortex Dynamics in a Superconducting Film with a Kagome and?a?Honeycomb Pinning Landscape

The vortex dynamics in a superconducting thin Al film with a periodic Honeycomb or Kagome array of antidots has been investigated by electrical transport measurements. The large values of the superconducting coherence length and penetration depth of the Al films guarantee a maximum of one flux quantum trapped per pinning site. This allows us to directly compare the experimental results with previous theoretical investigations based on molecular dynamics simulations. For the Kagome lattice, two submatching features not anticipated theoretically at H/H ₁=1/3 and 2/3, where H ₁ is the field at which the number of vortices coincides with the number of pinning sites, are observed. Possible corresponding stable vortex patterns are suggested. For the Honeycomb pinning landscape, the commensurability effects are in agreement with the theoretical expectations. A preliminary analysis of the vortex mobility in this lattice shows the presence of a weak vortex guidance.     

University of Science and Technology Beijing

University of Science and TechnologyBeijing (former Beijing University of Ironand Steel Technology)--one of the nationalleading universities, featuring in metallurgyand materials, is a polytechnic, takingengineering as main course and combiningtogether science, engineering, management     

Geopolymer concrete-filled pultruded composite beams – Concrete mix design and application

The limited research on the geopolymer concrete mix design for targeting a specific strength is identified an obstacle for their effective design and wide use. In this paper, a mix design procedure has been proposed for fly-ash based geopolymer concrete and its use as infill hybrid composite beam is investigated. Then, the structural performance of geopolymer concrete filled hybrid composite beam is investigated to determine their possible application in civil infrastructure. Firstly, a detailed procedure of mix design for fly-ash based geopolymer concrete is presented. Secondly, three hybrid beams filled with geopolymer concrete were prepared and tested in a four-point bending setup to evaluate their flexural modulus and modulus of rupture. Numerical and analytical evaluation of the behaviour of hybrid beam were performed and results showed a good agreement with the experimental investigation. Thirdly, the suitability of the beam for a composite railway sleeper is evaluated and compared with existing timber and composite sleepers. Finally, the beams’ performance in a ballast railway track is analysed using Strand7 finite element simulation software and the results showed that the new concept of using geopolymer concrete as infill to pultruded composite section satisfied the stiffness and strength requirements for a railway sleeper.     

Policy-Induced Environmental Technology and Inventive Efforts: Is There a Crowding Out?

Substantial policy effort is devoted to stimulate environmentally friendly technology through regulation and subsidies. Since innovation is a crucial productivity driver, a potential crowding out of inventive efforts in affected firms may increase the cost of regulation. We study the effects of regulation-induced environmental technology on innovation activities for a sample of firms in Germany. We find some evidence for a crowding out of firms' in-house R&D, especially for firms facing financing constraints. Innovation outcomes and investments in innovation-related fixed assets are not affected. Moreover, subsidy-backed environmental technology does not crowd out R&D.     

Network inertia and inbound open innovation: is there a bidirectional relationship?

Scientometrics - Based on the patent data collected from smartphone industry over the period 2000–2017, we utilize two-stage least squares to investigate the bidirectional relationship...     

Asymptotic burnout and homeostatic awakening: a possible solution to the Fermi paradox?

Previous studies show that city metrics having to do with growth, productivity and overall energy consumption scale superlinearly, attributing this to the social nature of cities. Superlinear scaling results in crises called ‘singularities’, where population and energy demand tend to infinity in a finite amount of time, which must be avoided by ever more frequent ‘resets’ or innovations that postpone the system''s collapse. Here, we place the emergence of cities and planetary civilizations in the context of major evolutionary transitions. With this perspective, we hypothesize that once a planetary civilization transitions into a state that can be described as one virtually connected global city, it will face an ‘asymptotic burnout’, an ultimate crisis where the singularity-interval time scale becomes smaller than the time scale of innovation. If a civilization develops the capability to understand its own trajectory, it will have a window of time to affect a fundamental change to prioritize long-term homeostasis and well-being over unyielding growth—a consciously induced trajectory change or ‘homeostatic awakening’. We propose a new resolution to the Fermi paradox: civilizations either collapse from burnout or redirect themselves to prioritizing homeostasis, a state where cosmic expansion is no longer a goal, making them difficult to detect remotely.     

Mechanosensitive channels and bacterial cell wall integrity: does life end with a bang or a whimper?

Mechanogated channels are fundamental components of bacterial cells that enable retention of physical integrity during extreme increases in cell turgor. Optical tweezers combined with microfluidics have been used to study the fate of individual Escherichia coli cells lacking such channels when subjected to a bursting stress caused by increased turgor. Fluorescence-activated cell sorting and electron microscopy complement these studies. These analyses show that lysis occurs with a high probability, but the precise path differs between individual cells. By monitoring the loss of cytoplasmic green fluorescent protein, we have determined that some cells release this protein but remain phase dark (granular) consistent with the retention of the majority of large proteins. By contrast, most cells suffer cataclysmic wall failure leading to loss of granularity but with the retention of DNA and overall cell shape (protein-depleted ghosts). The time span of these events induced by hypo-osmotic shock varies but is of the order of milliseconds. The data are interpreted in terms of the timing of mechanosensitive channel gating relative to osmotically induced water influx.     

Journal of Measurement Science and Instrumentation征稿启事

Journal of Measurement Science and Instrumentation(《测试科学与仪器》)是国家新闻出版总署批准的,由中北大学主办的英文类国际性学术期刊(批文:新出审字[2009]482号;刊号:CN14-1357/TH,季刊),刊登测试科学与仪器领域中有创新性的理论、实践、应用性研究论文,面向国内外征稿、发行。本刊致