15,984 research outputs found
AD Consolidation for operation beyond 2010
The Antiproton Decelerator (AD), which started up for physics in 2000 and today supplies low-energy antiprotons to the ATRAP, ALPHA, ASACUSA and ACE experiments is based on the ACOL machine from which it still retains most of the components. ACOL construction was completed in 1986 at a total cost of approximately 80 MCHF (excluding infrastructure) which today would correspond to a value of around 160 MCHF. During recent years, a reduction of maintenance and modernisation has been unavoidable due to budgetary restraints. In order to identify the resources needed for continued AD operation beyond 2010 with a reasonably low risk of failures and to avoid increasing maintenance and repair costs, a study has been conducted involving groups from the AB, AT and TS departments. Analysis of breakdown risks, identification of items and costs for consolidation has been done as well as a risk score classification. To be noted is the relatively modest cost of the proposed items in view of the value of the facility and in comparison to the cost of the manpower necessary for running AD. The two scenarios under consideration are (1): Continued operation until the end of 2012 with no major modifications to the AD machine and (2): Operation until the end of 2016 with the possibility to implement the proposed ELENA upgrade. In both scenarios, AEGIS can carry out the measurement that it has proposed to make. The success-oriented timeline of the A EGIS proposal, which foresees installation of the experiment in 2009 and 2010, commissioning and first data taking in 2011 and carrying-out of a first gravitational measurement with antihydrogen in the following year is compatible with a scenario of AD operation only until the end of 2012. However, running the AD until 2016 would in addition allow going beyond the initial validation of the technique and would permit a more thorough investigation of the systematic errors in order to reach the initial physics goal (a measurement of the gravitational interaction of antihydrogen to 1%) and perhaps improve on it, as well as a number of ancillary physics measurements which are interesting and publishable in their own right
Methodological issues in dynamic capabilities research - a critical review
Originality/value - This study is a novel contribution towards understanding the methods used in DC research. It introduces the issue of methodological fit into the DC discussion and highlights the methodological aspects that need to be considered and reported in more detail in future research articles. It also has implications on how to conceptualise DC
Deep Learning of Geometric Constellation Shaping including Fiber Nonlinearities
A new geometric shaping method is proposed, leveraging unsupervised machine
learning to optimize the constellation design. The learned constellation
mitigates nonlinear effects with gains up to 0.13 bit/4D when trained with a
simplified fiber channel model.Comment: 3 pages, 6 figures, submitted to ECOC 201
Dust in the Photospheric Environment II. Effect on the Near Infrared Spectra of L and T Dwarfs
We report an attempt to interpret the spectra of L and T dwarfs with the use
of the Unified Cloudy Model (UCM). For this purpose, we extend the grid of the
UCMs to the cases of log g = 4.5 and 5.5. The dust column density relative to
the gas column density in the observable photosphere is larger at the higher
gravities, and molecular line intensity is generally smaller at the higher
gravities. The overall spectral energy distributions (SEDs) are f_{J} < f_{H} <
f_{K} in middle and late L dwarfs, f_{J} f_{K} in early T dwarfs (L/T
transition objects), and finally f_{J} > f_{H} > f_{K} in middle and late T
dwarfs, where f_{J}, f_{H}, and f_{K} are the peak fluxes at J, H, and K bands,
respectively, in f_{nu} unit. This tendency is the opposite to what is expected
for the temperature effect, but can be accounted for as the effect of thin dust
clouds formed deep in the photosphere together with the effect of the gaseous
opacities including H_2 (CIA), H_2O, CH_4, and K I. Although the UCMs are
semi-empirical models based on a simple assumption that thin dust clouds form
in the region of T_{cr} < T < T_{cond} (T_{cr} = 1800K is an only empirical
parameter while T_{cond} about 2000K is fixed by the thermodynamical data), the
major observations including the overall SEDs as well as the strengths of the
major spectral features are consistently accounted for throughout L and T
dwarfs. In view of the formidable complexities of the cloud formation, we hope
that our UCM can be of some use as a guide for future modelings of the
ultracool dwarfs as well as for interpretation of observed data of L and T
dwarfs.Comment: 43 pages, 13 figures, to appear in Astrophys. J. (May 20, 2004) Some
minor corrections including the address of our web site, which is now read
The CERN Antiproton Decelerator (AD) Operation, Progress and Plans for the Future
The CERN Antiproton Decelerator (AD) is a simplified source providing low energy antiprotons for experiments, replacing four machines: AC (Antiproton Collector), AA (Antiproton Accumulator), PS and LEAR (Low Energy Antiproton Ring), shut down in 1996. The former AC was modified to include deceleration, electron cooling and ejection lines into the new experimental area. The AD started physics operation in July 2000 and has since delivered cooled beams at 100 MeV/c (kinetic energy of 5.3 MeV) to 3 experiments (ASACUSA, ATHENA and ATRAP). Problems encountered during the commissioning and the physics runs will be outlined as well as progress during 2001 and possible future developments
Hygiene norms across 56 nations are predicted by self-control values and disease threat
Three major theories could potentially explain why hygiene norms vary across societies: tightness-looseness theory, disease threat theory, and theory of a civilizing process driven by how self-control is valued. We test these theories using data from a study of 56 countries across the globe, in which almost 20,000 participants reported their norms about spitting in six different contexts, hand washing in six different contexts, and tooth brushing. Participants also reported the perceived tightness of their society, whether they perceived diseases as a threat to their society, and their valuation of self-control. In support of the civilizing process, most of the norms in our study (including most hand washing norms and most spitting norms) were stricter in countries where self-control is valued more highly. A few norms did not follow this main pattern and these norms were instead stricter in countries where disease was perceived as a greater threat. Thus, while the theory of a civilizing process received the strongest support, our data indicate that some combination with the disease threat theory may be required to fully explain country-variation in hygiene norms
Global sex differences in hygiene norms and their relation to sex equality
Strict norms about hygiene may sometimes have health benefits but may also be a burden. Based on research in the United States, it has been suggested that women traditionally shoulder responsibility for hygiene standards and therefore tend to have stricter views on hygiene. However, there is little systematic research on sex differences in hygiene norms at the global scale. We set up two hypotheses: (1) Stricter hygiene norms among women than among men is a global phenomenon. (2) The size of this sex difference varies across nations with the level of sex equality. We examine these hypotheses using data from a recent international survey (N = 17,632). Participants in 56 countries were asked for their views of where it is not appropriate for people to spit and in which situations people should wash their hands. As a measure of sex equality, we use an existing country-level measure of attitudes to equality between the sexes, available for 49 nations in the study. Stricter hygiene norms among women than among men are observed almost everywhere, but there are a few exceptions (most notably Nigeria and Saudi Arabia). The size of the sex difference in hygiene norms varies strongly with the level of sex equality, but in a non-linear way. The sex difference is most pronounced in moderately egalitarian countries with the highest recorded difference being in Chile. In more egalitarian parts of the world, more sex equality is associated with a smaller sex difference in hygiene norms. In the less egalitarian parts of the world, the opposite relation holds. We offer an interpretation in terms of what different levels of sex equality mean for the content of sex roles
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