12,962 research outputs found

    Front-End electronics configuration system for CMS

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    The four LHC experiments at CERN have decided to use a commercial SCADA (Supervisory Control And Data Acquisition) product for the supervision of their DCS (Detector Control System). The selected SCADA, which is therefore used for the CMS DCS, is PVSS II from the company ETM. This SCADA has its own database, which is suitable for storing conventional controls data such as voltages, temperatures and pressures. In addition, calibration data and FE (Front-End) electronics configuration need to be stored. The amount of these data is too large to be stored in the SCADA database [1]. Therefore an external database will be used for managing such data. However, this database should be completely integrated into the SCADA framework, it should be accessible from the SCADA and the SCADA features, e.g. alarming, logging should be benefited from. For prototyping, Oracle 8i was selected as the external database manager. The development of the control system for calibration constants and FE electronics configuration has been done in close collaboration with the CMS tracker group and JCOP (Joint COntrols Project)(1). (1)The four LHC experiments and the CERN IT/CO group has merged their efforts to build the experiments controls systems and set up the JCOP at the end of December, 1997 for this purpose.Comment: 3 pages, 4 figures, Icaleps'01 conference PSN WEDT00

    AN ECONOMIC ANALYSIS OF A CORN-SOYBEAN CROP ROTATION UNDER VARIOUS INPUT COMBINATIONS IN SOUTH CENTRAL TEXAS

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    Eight input combinations of commercial fertilizer, insecticides, and herbicides on a corn-soybean crop rotation in the Brazos River Bottom of Texas are evaluated. Input combinations which do not fully utilize all three inputs are consistently ranked higher by all criteria as the preferred input strategy for the corn-soybean rotation system. These results, which indicate limited input crop rotations that fall somewhere between the extremes of conventional agricultural production and organic agriculture, deserve further attention as a possible production alternative.corn, limited input, soybean, Crop Production/Industries,

    Differential effects of caffeine on hair shaft elongation, matrix and outer root sheath keratinocyte proliferation, and TGF-beta2-/IGF-1-mediated regulation of hair cycle in male and female human hair follicles in vitro.

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    BACKGROUND: Caffeine reportedly counteracts the suppression of hair shaft production by testosterone in organ-cultured male human hair follicles (HFs). OBJECTIVES: We aimed at investigating the impact of caffeine a) on additional key hair growth parameters, b) on major hair growth-regulatory growth factors and c) on male versus female HFs in the presence of testosterone. METHODS: Microdissected male and female human scalp HFs were treated in serum-free organ culture for 120 h with testosterone alone (0,5 mug/ml) or in combination with caffeine (0.005-0.0005%), and effects on hair shaft elongation, HF cycling (i.e. anagen-catagen transition), hair matrix keratinocyte proliferation and expression of a key catagen inducer, transforming growth factor beta2 (TGF-beta2), and anagen-prolonging insulin-like growth factor 1 (IGF-1) were evaluated by quantitative (immuno-) histomorphometry. Caffeine effects were further investigated in human outer root sheath keratinocytes (ORSK). RESULTS: Caffeine enhanced hair shaft elongation, prolonged anagen duration and stimulated hair matrix keratinocyte proliferation. Female HFs showed higher sensitivity to caffeine compared to male HFs. Caffeine counteracted testosterone-enhanced TGF-beta2 protein expression in male HFs. In female HFs, testosterone failed to induce TGF-beta2 expression, while caffeine reduced it. In male and female HFs, caffeine enhanced IGF-1 protein expression. In ORSK, caffeine stimulated cell proliferation, inhibited apoptosis/necrosis, up-regulated IGF-1 gene expression and protein secretion, while TGF-beta2 protein secretion was down-regulated. CONCLUSIONS: This study reveals new growth-promoting effects of caffeine on human hair follicles of both genders at different (molecular, cellular and organ) levels. This article is protected by copyright. All rights reserved

    Search for axions in streaming dark matter

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    A new search strategy for the detection of the elusive dark matter (DM) axion is proposed. The idea is based on streaming DM axions, whose flux might get temporally enormously enhanced due to gravitational lensing. This can happen if the Sun or some planet (including the Moon) is found along the direction of a DM stream propagating towards the Earth location. The experimental requirements to the axion haloscope are a wide-band performance combined with a fast axion rest mass scanning mode, which are feasible. Once both conditions have been implemented in a haloscope, the axion search can continue parasitically almost as before. Interestingly, some new DM axion detectors are operating wide-band by default. In order not to miss the actually unpredictable timing of a potential short duration signal, a network of co-ordinated axion antennae is required, preferentially distributed world-wide. The reasoning presented here for the axions applies to some degree also to any other DM candidates like the WIMPs.Comment: 5 page

    Actions of the braid group, and new algebraic proofs of results of Dehornoy and Larue

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    This article surveys many standard results about the braid group with emphasis on simplifying the usual algebraic proofs. We use van der Waerden's trick to illuminate the Artin-Magnus proof of the classic presentation of the algebraic mapping-class group of a punctured disc. We give a simple, new proof of the Dehornoy-Larue braid-group trichotomy, and, hence, recover the Dehornoy right-ordering of the braid group. We then turn to the Birman-Hilden theorem concerning braid-group actions on free products of cyclic groups, and the consequences derived by Perron-Vannier, and the connections with the Wada representations. We recall the very simple Crisp-Paris proof of the Birman-Hilden theorem that uses the Larue-Shpilrain technique. Studying ends of free groups permits a deeper understanding of the braid group; this gives us a generalization of the Birman-Hilden theorem. Studying Jordan curves in the punctured disc permits a still deeper understanding of the braid group; this gave Larue, in his PhD thesis, correspondingly deeper results, and, in an appendix, we recall the essence of Larue's thesis, giving simpler combinatorial proofs.Comment: 51`pages, 13 figure

    XMM-Newton observations of HESS J1813-178 reveal a composite Supernova remnant

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    We present X-ray and 12CO(J=1-0) observations of the very-high-energy (VHE) gamma-ray source HESS J1813-178 with the aim of understanding the origin of the gamma-ray emission. Using this dataset we are able to undertake spectral and morphological studies of the X-ray emission from this object with greater precision than previous studies. NANTEN 12CO(J=1-0) data are used to search for correlations of the gamma-ray emission with molecular clouds which could act as target material for gamma-ray production in a hadronic scenario. The NANTEN 12CO(J=1-0) observations show a giant molecular cloud of mass 2.5 10^5 M_{\sun} at a distance of 4 kpc in the vicinity of HESS J1813-178. Even though there is no direct positional coincidence, this giant cloud might have influenced the evolution of the gamma-ray source and its surroundings. The X-ray data show a highly absorbed non-thermal X-ray emitting object coincident with the previously known ASCA source AX J1813-178 showing a compact core and an extended tail towards the north-east, located in the centre of the radio shell-type Supernova remnant (SNR) G12.82-0.2. This central object shows morphological and spectral resemblance to a Pulsar Wind Nebula (PWN) and we therefore consider that the object is very likely to be a composite SNR. We discuss the scenario in which the gamma-rays originate in the shell of the SNR and the one in which they originate in the central object. We demonstrate, that in order to connect the core X-ray emission to the VHE gamma-ray emission electrons have to be accelerated to energies of at least 1 PeV.Comment: Submitted to A&

    Water resources: future Nile river flows

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    Climate change is projected to increase annual Nile river flow; importantly, year-to-year variability is also expected to increase markedly. More variable flows could present a challenge for consistent water resource provision in this region

    Holey Carbon Nanotubes from Controlled Air Oxidation

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    Defects in various nanomaterials are often desirable to enable enhanced functional group attachments and attain properties that are not available with their intact counterparts. A new paradigm in the defective low-dimensional carbon nanomaterials is to create holes on the graphitic surfaces via partial etching. For example, holey graphene, graphene sheets with through-thickness holes, was synthesized using several different partial etching approaches and found useful for various applications such as field-effect transistors, sensors, energy storage devices, and separation membranes. In these applications, the presence of holes led to unique advantages, such as bandgap widening, chemical functionalization of hole edges, improved through-the-thickness ion transport with lowered tortuosity, and improved accessible surface area. Here, we present a facile method to prepare holey carbon nanotubes via controlled air oxidation. Although no additional catalyst was added, the residual iron nanoparticles from nanotube growth encapsulated in the nanotube cavity significantly contributed to the hole generation through the nanotube walls. The holey carbon nanotube products exhibited enhanced surface area, pore volume, and oxygen-containing functional groups, which led to their much enhanced electrochemical capacitive properties. Synthesis and characterization details of this novel class of holey carbon nanomaterials are presented, and their potential applications are discussed
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