4,464 research outputs found
Development of a Detector Control System for the ATLAS Pixel Detector
The innermost part of the ATLAS experiment will be a pixel detector
containing around 1750 individual detector modules. A detector control system
(DCS) is required to handle thousands of I/O channels with varying
characteristics. The main building blocks of the pixel DCS are the cooling
system, the power supplies and the thermal interlock system, responsible for
the ultimate safety of the pixel sensors. The ATLAS Embedded Local Monitor
Board (ELMB), a multi purpose front end I/O system with a CAN interface, is
foreseen for several monitoring and control tasks. The Supervisory, Control And
Data Acquisition (SCADA) system will use PVSS, a commercial software product
chosen for the CERN LHC experiments. We report on the status of the different
building blocks of the ATLAS pixel DCS.Comment: 3 pages, 2 figures, ICALEPCS 200
Algebraic properties of Gardner's deformations for integrable systems
An algebraic definition of Gardner's deformations for completely integrable
bi-Hamiltonian evolutionary systems is formulated. The proposed approach
extends the class of deformable equations and yields new integrable
evolutionary and hyperbolic Liouville-type systems. An exactly solvable
two-component extension of the Liouville equation is found.Comment: Proc. conf. "Nonlinear Physics: Theory and Experiment IV" (Gallipoli,
2006); Theor. Math. Phys. (2007) 151:3/152:1-2, 16p. (to appear
Organisational policies and practices for the inclusion of vulnerable workers:A scoping review of the employer’s perspective
Purpose Current models of inclusive workplaces are primarily based on the perceptions of vulnerable workers, whereas attention for employer’s perceptions is lacking. This scoping review addresses this issue by mapping the literature that covers employer’s perceptions on the application and importance of organisational policies and practices aimed at the inclusion of vulnerable workers. Methods A literature search for qualitative and quantitative research articles was conducted in MEDLINE, Scopus, ProQuest, PsychInfo, Google Scholar and Web of Science. Studies were included when (a) they reported on practices aimed at the inclusion, participation, or rehabilitation of (b) workers with disabilities, a low education or migration background, or who were long-term unemployed, and (c) were based on samples of employers or their representatives. Results The search resulted in 3,134 articles. In total, 38 articles met the inclusion criteria of this study. We identified seven types of inclusive practices to stimulate the inclusion of vulnerable workers that employers applied and/or perceived as valuable: senior management commitment, recruitment and selection, performance management and development practices, job accommodations and redesign of work, supportive culture, external collaborations with other employers, and monitoring. Conclusions Our review identified seven categories of inclusive practices that pertain to all stages of the employee journey of vulnerable workers. These categories move beyond those reported in studies based on employee samples, for instance by highlighting the importance of monitoring and collaborations with other employers. Hence, our findings stress that insight into employers’ perceptions about effective measures is crucial to increase labour market participation of vulnerable groups
Particles as probes for complex plasmas in front of biased surfaces
An interesting aspect in the research of complex (dusty) plasmas is the
experimental study of the interaction of micro-particles with the surrounding
plasma for diagnostic purposes. Local electric fields can be determined from
the behaviour of particles in the plasma, e.g. particles may serve as
electrostatic probes. Since in many cases of applications in plasma technology
it is of great interest to describe the electric field conditions in front of
floating or biased surfaces, the confinement and behaviour of test particles is
studied in front of floating walls inserted into a plasma as well as in front
of additionally biased surfaces. For the latter case, the behaviour of
particles in front of an adaptive electrode, which allows for an efficient
confinement and manipulation of the grains, has been experimentally studied in
dependence on the discharge parameters and on different bias conditions of the
electrode. The effect of the partially biased surface (dc, rf) on the charged
micro-particles has been investigated by particle falling experiments. In
addition to the experiments we also investigate the particle behaviour
numerically by molecular dynamics, in combination with a fluid and
particle-in-cell description of the plasma.Comment: 39 pages, 16 figures, submitted to New J. Phy
Detectors for Energy-Resolved Fast Neutron Imaging
Two detectors for energy-resolved fast-neutron imaging in pulsed broad-energy
neutron beams are presented. The first one is a neutron-counting detector based
on a solid neutron converter coupled to a gaseous electron multiplier (GEM).
The second is an integrating imaging technique, based on a scintillator for
neutron conversion and an optical imaging system with fast framing capability
Physics at a Fermilab Proton Driver
This report documents the physics case for building a 2 MW, 8 GeV
superconducting linac proton driver at Fermilab.Comment: 52 pages, 15 figure
Classification of polynomial integrable systems of mixed scalar and vector evolution equations. I
We perform a classification of integrable systems of mixed scalar and vector
evolution equations with respect to higher symmetries. We consider polynomial
systems that are homogeneous under a suitable weighting of variables. This
paper deals with the KdV weighting, the Burgers (or potential KdV or modified
KdV) weighting, the Ibragimov-Shabat weighting and two unfamiliar weightings.
The case of other weightings will be studied in a subsequent paper. Making an
ansatz for undetermined coefficients and using a computer package for solving
bilinear algebraic systems, we give the complete lists of 2nd order systems
with a 3rd order or a 4th order symmetry and 3rd order systems with a 5th order
symmetry. For all but a few systems in the lists, we show that the system (or,
at least a subsystem of it) admits either a Lax representation or a linearizing
transformation. A thorough comparison with recent work of Foursov and Olver is
made.Comment: 60 pages, 6 tables; added one remark in section 4.2.17 (p.33) plus
several minor changes, to appear in J.Phys.
Influencia do acido indolbutirico (IBA) no enraizamento de estacas semi-lenhosas de figueira (Ficus carica L.) Roxo de Valinhos em condicoes de nebulizacao intermitente.
Estudou-se o efeito de 6 concentracoes do acido indolbutirico no enraizamento e brotacao de estacas de figueira (Ficus carica L.) cv. Roxo de Valinhos, em casa de vegetacao, sob condicoes de nebulizacao durante o verao de 1980 em Pelotas,RS, Brasil. O delineamento estatistico foi inteiramente casualizado com 6 tratamentos e 6 repeticoes com dez estacas por parcela. Utilizaram-se estacas semilenhosas de 23 cm de comprimento, com e sem folha, da parte terminal do ramo. Todas as estacas foram tratadas basalmente durante cinco segundos com IBA nas concentracoes 0; 200; 400; 600; 800 e 1000ppm. diluido em etanol a 50%, sendo, apos, colocadas em vasos sob condicoes de nebulizacao artificial intermitente. O IBA aumentou linearmente a percentagem de estacas enraizadas, de figueira com folha, ate 1000ppm, enquanto que em figueira sem folha nao diferiram estatisticamente entre si. A concentracao 400ppm de IBA, proporcionou maior percentagem 87% de estacas enraizadas. Para as estacas brotadas com e sem folha as concentracoes de IBA apresentaram efeitos significativos, resultando em 74% de estacas brotadas para figueira com folhas e 84% para sem folha, nas concentracoes 1000 e 400ppm de IBA, respectivamente. Os rsultados obtidos indicam que em condicao de nebulizacao ha viabilidade de propagacao vegetativa da figueira com estacas semilenhosas ampliando a epoca de enraizamento de estacas para obtencao de mudas em menor tempo
Impact of massive neutrinos on the Higgs self-coupling and electroweak vacuum stability
The presence of right-handed neutrinos in the type I seesaw mechanism may
lead to significant corrections to the RG evolution of the Higgs self-coupling.
Compared to the Standard Model case, the Higgs mass window can become narrower,
and the cutoff scale become lower. Naively, these effects decrease with
decreasing right-handed neutrino mass. However, we point out that the unknown
Dirac Yukawa matrix may impact the vacuum stability constraints even in the low
scale seesaw case not far away from the electroweak scale, hence much below the
canonical seesaw scale of 10^15 GeV. This includes situations in which
production of right-handed neutrinos at colliders is possible. We illustrate
this within a particular parametrization of the Dirac Yukawas and with explicit
low scale seesaw models. We also note the effect of massive neutrinos on the
top quark Yukawa coupling, whose high energy value can be increased with
respect to the Standard Model case.Comment: 17 pages, 7 figures, minor revisions, version to appear in JHE
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