The Diffusion Network of Research Knowledge in Operations Management

Purpose: To examine how the research knowledge in OM has been obtained and distributed since the first journals in OM began publication in 1980, changes in the interests of OM over the decades and where they are heading in the future, and to explore the changing roles of individual journals in the development of OM. Design/methodology/approach: A two-stage bibliometric study was employed, first using citation analysis to examine the changing research interests in OM through an analysis of the OM journals. Then the top journals of most importance to OM were analysed to determine the role that each one played in the knowledge distribution network and how that changed over the decades. Findings: OM’s journal base consists of 7 research knowledge sources, 12 transmitters linking different journal groups, and 11 sinks with limited input. Research attention changed from practice, engineering, and OR to general management, strategy, and production management in the 2000s, with strategy, organizational issues, and logistics surfacing in the 2010s. OM features increasingly academic research with less interest in practice. OM journals’ network importance has increased substantially, with JOM now a bridge between the quantitative and management journals. Practical implications Both researchers and managers gain in understanding the history and identifying the future direction of OM, as well as which journals will have the most relevant papers to their interests. Originality/value: This research identifies the history of the OM field in terms of its constituents and where it is going in the future. This history is related to the role OM plays among the knowledge network of top journals and presents a novel way of classifying and labeling journals based on their contribution

Advanced coatings through pulsed magnetron sputtering

Pulsed magnetron sputtering (PMS) has become established as the process of choice for the deposition of dielectric materials for many applications. The process is attractive because it offers stable arc free operating conditions during the deposition of, for example, functional films on architectural and automotive glass, or antireflective/antistatic coatings on displays. Recent studies have shown that pulsing the magnetron discharge also leads to hotter and more energetic plasmas in comparison with continuous dc discharges, with increased ion energy fluxes delivered to the substrate. As such, the PMS process offers benefits in the deposition of a wide range of materials. The present paper describes three examples where PMS has led to either significant enhancement in film properties or enhanced process flexibility: in low friction titanium nitride coatings, in Al doped zinc oxide transparent conductive oxide coatings sputtered directly from powder targets and in thin film photovoltaic devices based on copper (indium/gallium) diselenide. These examples demonstrate the versatility of PMS and open up new opportunities for the production of advanced coatings using this technique

Teacher Candidates: Vocal Health

Classroom teachers are at high risk for developing voice problems and may experience positive benefits from vocal health education. Less is known about the experiences of student teachers. The objective of the study was to determine if vocal hygiene education affects the student teachers’ vocal knowledge, vocal habits, voice quality, and their self-perception of their voice. Eight female education students who were student teaching the semester of the study were randomized into either the Experimental Group (who received vocal health information before their student teaching semester) or the Control Group. Both groups were assessed using a battery of qualitative and quantitative instruments at the beginning, middle, and end of the semester. There were no statistically significant differences between the Experimental Group and the Control Group on vocal hygiene knowledge, vocal hygiene habits, VHI-10 score, and all CAPE-V ratings. Analysis of the individual differences, however, indicate that knowledge of vocal health may influence other variables related to vocal health. Analysis of the qualitative data indicates that seven of the eight student teachers experienced problems with their voice and that all four members of the Control Group wanted information about vocal health. Due to potential limitations of the study, the researchers were not able to determine whether educational information resulted in fewer incidences of voice problems, but the data suggest, similar to classroom teachers, that student teachers are at high risk for developing voice problems during their student teaching practicum and they too may benefit from information on prevention of voice problems

Constraints on large scalar multiplets from perturbative unitarity

We determine the constraints on the isospin and hypercharge of a scalar electroweak multiplet from partial-wave unitarity of tree-level scattering diagrams. The constraint from SU(2)_L interactions yields T <= 7/2 (i.e., n <= 8) for a complex scalar multiplet and T <= 4 (i.e., n <= 9) for a real scalar multiplet, where n = 2T+1 is the number of isospin states in the multiplet.Comment: 10 pages, 1 figure. v2: refs added, minor additions to text, submitted to PR

Macrophage activation syndrome triggered by coeliac disease: a unique case report

Background: Macrophage activation syndrome is described as a “clinical syndrome of hyperinflammation resulting in an uncontrolled and ineffective immune response” in the context of an autoinflammatory or rheumatic disease. Current associations of macrophage activation syndrome with autoimmune disease most notably include a host of rheumatological conditions and inflammatory bowel disease. Epidemiological studies have shown that macrophage activation syndrome is precipitated by autoimmune disease more commonly than previously thought. Diagnosing the precipitating factor is essential for effective treatment and prognosis. Case presentation: We report a case of a six year old girl with coeliac disease diagnosed after two episodes of secondary haemophagocytic lymphohistiocytosis. Her condition only responded to treatment once the patient was placed on a gluten free diet. Further immunological testing confirmed anti-transglutaminase and anti-endomysial antibodies, however histological biopsy was deemed inappropriate due to the severity of her condition. She has remained stable with no further episodes of macrophage activation syndrome since commencing a gluten free diet. Conclusion: This case report is the first literature that links macrophage activation syndrome to coeliac disease and highlights the challenge of diagnosing coeliac disease with unusual features such as associated prolonged fever. Clinicians should have a low threshold for screening children with other autoimmune diseases for coeliac disease

The role of feedback in shaping the structure of the interstellar medium

We present an analysis of the role of feedback in shaping the neutral hydrogen (H I) content of simulated disc galaxies. For our analysis, we have used two realizations of two separate Milky Way-like (similar to L star) discs - one employing a conservative feedback scheme (McMaster Unbiased Galaxy Survey), the other significantly more energetic [Making Galaxies In a Cosmological Context (MaGICC)]. To quantify the impact of these schemes, we generate zeroth moment (surface density) maps of the inferred H I distribution; construct power spectra associated with the underlying structure of the simulated cold interstellar medium, in addition to their radial surface density and velocity dispersion profiles. Our results are compared with a parallel, self-consistent, analysis of empirical data from The H I Nearby Galaxy Survey (THINGS). Single power-law fits (P proportional to k(gamma)) to the power spectra of the stronger feedback (MaGICC) runs (over spatial scales corresponding to similar to 0.5 to similar to 20 kpc) result in slopes consistent with those seen in the THINGS sample (gamma similar to -2.5). The weaker feedback (MUGS) runs exhibit shallower power-law slopes (gamma similar to -1.2). The power spectra of the MaGICC simulations are more consistent though with a two-component fit, with a flatter distribution of power on larger scales (i.e. gamma similar to -1.4 for scales in excess of similar to 2 kpc) and a steeper slope on scales below similar to 1 kpc (gamma similar to -5), qualitatively consistent with empirical claims, as well as our earlier work on dwarf discs. The radial H I surface density profiles of the MaGICC discs show a clear exponential behaviour, while those of the MUGS suite are essentially flat; both behaviours are encountered in nature, although the THINGS sample is more consistent with our stronger (MaGICC) feedback runs

Probing the reactivity of a 2,2′-bipyridyl-3,3′-bis-imine ligand by X-ray crystallography

The reactivity of a Schiff-base bis-imine ligand 3 is probed by X-ray diffraction studies. Its susceptibility to hydrolysis, oxidation and nucleophilic addition reactions is demonstrated by the isolation of the methanol adduct 4 and two diazapene heterocycles 5 and 6. This reactivity is also reflected in the molecular structures of two coordination complexes isolated by the reaction of 3 with MIJhfac)2 salts, to afford [Cu(5)-(hfac)(tfa)] (8) and [Zn(6)(hfac)2] (9)