310 research outputs found
Impact pathways: a home for insights from relevant and impactful operations and supply chain management research
Purpose: International Journal of Operations and Production Management (IJOPM)'s Impact Pathway (IP) section has been launched in 2020 to host short contributions grounded in current managerial practices and/or policy development, challenging established operations and supply chain management (OSCM) knowledge and highlighting innovative and relevant research directions. This commentary reflects on the achievements of the section, delineates the key features of IP papers and stimulates further development. Design/methodology/approach: This commentary provides a brief overview of the IJOPM's IP section, taking stock of the contributions that have been published so far, analysing their topics, methodologies, insights and impact. Findings: The 19 contributions published over the last three years have dealt with a variety of emerging topics, ranging from the COVID-19 response to additive manufacturing, leveraging on key evidence from managerial practice that challenges consolidated knowledge and theory, providing clear research directions as well as managerial and/or policy guidelines. Originality/value: The commentary reflects on the importance of phenomenon-driven research that seeks to bridge the gap between theory and practice, thus increasing the impact and reach of OSCM research. This is a call for contributions from scholars, business leaders and policymakers to develop further impact-oriented research
Rapidity-dependent chemical potentials in a statistical approach
We present a single-freeze-out model with thermal and geometric parameters
dependent on the position within the fireball and use it to describe the
rapidity and transverse-momentum spectra of pions, kaons, protons, and
antiprotons measured at RHIC at 200 GeV} by BRAHMS. THERMINATOR is used to
perform the necessary simulation, which includes all resonance decays. The
result of the fit to the data is the expected growth of the baryon and strange
chemical potentials with the spatial rapidity\alpha_\parallel. The value of the
baryon chemical potential at \alpha_\parallel ~ 3 is about 200 MeV, i.e. lies
in the range of the highest SPS energies. The chosen geometry of the fireball
has a decreasing transverse size as the magnitude of \alpha_\parallel is
increased, which also corresponds to decreasing transverse flow. The strange
chemical potential obtained from the fit to the K+/K- ratio is such that the
local strangeness density in the fireball is compatible with zero. The
resulting rapidity spectra of net protons are described qualitatively within
the statistical approach. As a result of our study, the knowledge of the
``topography'' of the fireball is acquired, allowing for other analyses and
predictions.Comment: 6 pages, tals at SQM 200
Development of Wireless Techniques in Data and Power Transmission - Application for Particle Physics Detectors
Wireless techniques have developed extremely fast over the last decade and
using them for data and power transmission in particle physics detectors is not
science- fiction any more. During the last years several research groups have
independently thought of making it a reality. Wireless techniques became a
mature field for research and new developments might have impact on future
particle physics experiments. The Instrumentation Frontier was set up as a part
of the SnowMass 2013 Community Summer Study [1] to examine the instrumentation
R&D for the particle physics research over the coming decades: {\guillemotleft}
To succeed we need to make technical and scientific innovation a priority in
the field {\guillemotright}. Wireless data transmission was identified as one
of the innovations that could revolutionize the transmission of data out of the
detector. Power delivery was another challenge mentioned in the same report. We
propose a collaboration to identify the specific needs of different projects
that might benefit from wireless techniques. The objective is to provide a
common platform for research and development in order to optimize effectiveness
and cost, with the aim of designing and testing wireless demonstrators for
large instrumentation systems
Impact pathways: a home for insights from relevant and impactful operations and supply chain management research
Purpose: International Journal of Operations and Production Management (IJOPM)'s Impact Pathway (IP) section has been launched in 2020 to host short contributions grounded in current managerial practices and/or policy development, challenging established operations and supply chain management (OSCM) knowledge and highlighting innovative and relevant research directions. This commentary reflects on the achievements of the section, delineates the key features of IP papers and stimulates further development. Design/methodology/approach: This commentary provides a brief overview of the IJOPM's IP section, taking stock of the contributions that have been published so far, analysing their topics, methodologies, insights and impact. Findings: The 19 contributions published over the last three years have dealt with a variety of emerging topics, ranging from the COVID-19 response to additive manufacturing, leveraging on key evidence from managerial practice that challenges consolidated knowledge and theory, providing clear research directions as well as managerial and/or policy guidelines. Originality/value: The commentary reflects on the importance of phenomenon-driven research that seeks to bridge the gap between theory and practice, thus increasing the impact and reach of OSCM research. This is a call for contributions from scholars, business leaders and policymakers to develop further impact-oriented research
Source Dimensions in Ultrarelativistic Heavy Ion Collisions
Recent experiments on pion correlations, interpreted as interferometric
measurements of the collision zone, are compared with models that distinguish a
prehadronic phase and a hadronic phase. The models include prehadronic
longitudinal expansion, conversion to hadrons in local kinetic equilibrium, and
rescattering of the produced hadrons. We find that the longitudinal and outward
radii are surprisingly sensitive to the algorithm used for two-body collisions.
The longitudinal radius measured in collisions of 200 GeV/u sulfur nuclei on a
heavy target requires the existence of a prehadronic phase which converts to
the hadronic phase at densities around 0.8-1.0 GeV/fm. The transverse radii
cannot be reproduced without introducing more complex dynamics into the
transverse expansion.Comment: RevTeX 3.0, 28 pages, 6 figures, not included, revised version, major
change is an additional discussion of the classical two-body collision
algorithm, a (compressed) postscript file of the complete paper including
figures can be obtained from Authors or via anonymous ftp at
ftp://ftp_int.phys.washington.edu/pub/herrmann/pisource.ps.
Isolation of Salmonella mutants resistant to the inhibitory effect of Salicylidene acylhydrazides on flagella-mediated motility.
Salicylidene acylhydrazides identified as inhibitors of virulence-mediating type III secretion systems (T3SSs) potentially target their inner membrane export apparatus. They also lead to inhibition of flagellar T3SS-mediated swimming motility in Salmonella enterica serovar. Typhimurium. We show that INP0404 and INP0405 act by reducing the number of flagella/cell. These molecules still inhibit motility of a Salmonella ΔfliH-fliI-fliJ/flhB((P28T)) strain, which lacks three soluble components of the flagellar T3S apparatus, suggesting that they are not the target of this drug family. We implemented a genetic screen to search for the inhibitors' molecular target(s) using motility assays in the ΔfliH-fliI/flhB((P28T)) background. Both mutants identified were more motile than the background strain in the absence of the drugs, although HM18 was considerably more so. HM18 was more motile than its parent strain in the presence of both drugs while DI15 was only insensitive to INP0405. HM18 was hypermotile due to hyperflagellation, whereas DI15 was not hyperflagellated. HM18 was also resistant to a growth defect induced by high concentrations of the drugs. Whole-genome resequencing of HM18 indicated two alterations within protein coding regions, including one within atpB, which encodes the inner membrane a-subunit of the F(O)F(1)-ATP synthase. Reverse genetics indicated that the alteration in atpB was responsible for all of HM18's phenotypes. Genome sequencing of DI15 uncovered a single A562P mutation within a gene encoding the flagellar inner membrane protein FlhA, the direct role of which in mediating drug insensitivity could not be confirmed. We discuss the implications of these findings in terms of T3SS export apparatus function and drug target identification.Funding: IMA and XL were supported by Wellcome Trust Project Grant 088266 to IMA and AJB. AKJV was funded by an E.C. Marie Curie postdoctoral fellowship (MEIF-CT-2005-023694) and an EMBO short-term fellowship (244-2007). XL was supported additionally by Wellcome Trust Project Grant 088231 to AJB and KN. DR was supported by a University of Bristol Centenary Postgraduate Studentship. This work was also supported in part by MRC project grants G0701243 and MR-J002097-1 to AJB and AJB and KN, respectively, and by Grants-in-Aid for Scientific Research (22570161 and 23121516 to TM, and 21227006 to KN) and Targeted Proteins Research Program from the Ministry of Education, Culture, Sports, Science and Technology of Japan and by Takeda Science Foundation (to TM). YVM is a Research Fellow of the Japanese Society for the Promotion of Science. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript
NA61/SHINE facility at the CERN SPS: beams and detector system
NA61/SHINE (SPS Heavy Ion and Neutrino Experiment) is a multi-purpose
experimental facility to study hadron production in hadron-proton,
hadron-nucleus and nucleus-nucleus collisions at the CERN Super Proton
Synchrotron. It recorded the first physics data with hadron beams in 2009 and
with ion beams (secondary 7Be beams) in 2011.
NA61/SHINE has greatly profited from the long development of the CERN proton
and ion sources and the accelerator chain as well as the H2 beamline of the
CERN North Area. The latter has recently been modified to also serve as a
fragment separator as needed to produce the Be beams for NA61/SHINE. Numerous
components of the NA61/SHINE set-up were inherited from its predecessors, in
particular, the last one, the NA49 experiment. Important new detectors and
upgrades of the legacy equipment were introduced by the NA61/SHINE
Collaboration.
This paper describes the state of the NA61/SHINE facility - the beams and the
detector system - before the CERN Long Shutdown I, which started in March 2013
Signatures of Quark-Gluon-Plasma formation in high energy heavy-ion collisions: A critical review
A critical review on signatures of Quark-Gluon-Plasma formation is given and
the current (1998) experimental status is discussed. After giving an
introduction to the properties of QCD matter in both, equilibrium- and
non-equilibrium theories, we focus on observables which may yield experimental
evidence for QGP formation. For each individual observable the discussion is
divided into three sections: first the connection between the respective
observable and QGP formation in terms of the underlying theoretical concepts is
given, then the relevant experimental results are reviewed and finally the
current status concerning the interpretation of both, theory and experiment, is
discussed. A comprehensive summary including an outlook towards RHIC is given
in the final section.Comment: Topical review, submitted to Journal of Physics G: 68 pages,
including 39 figures (revised version: only minor modifications, some
references added
Over 65% sunlight absorption in a 1 mu m Si slab with hyperuniform texture
Thin, flexible, and invisible solar cells will be a ubiquitous technology in the near future. Ultrathin crystalline silicon (c-Si) cells capitalize on the success of bulk silicon cells while being lightweight and mechanically flexible, but suffer from poor absorption and efficiency. Here we present a new family of surface texturing, based on correlated disordered hyperuniform patterns, capable of efficiently coupling the incident spectrum into the silicon slab optical modes. We experimentally demonstrate 66.5% solar light absorption in free-standing 1 μm c-Si layers by hyperuniform nanostructuring for the spectral range of 400 to 1050 nm. The absorption equivalent photocurrent derived from our measurements is 26.3 mA/cm2, which is far above the highest found in literature for Si of similar thickness. Considering state-of-the-art Si PV technologies, we estimate that the enhanced light trapping can result in a cell efficiency above 15%. The light absorption can potentially be increased up to 33.8 mA/cm2 by incorporating a back-reflector and improved antireflection, for which we estimate a photovoltaic efficiency above 21% for 1 μm thick Si cells
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