489 research outputs found

    Update on the CERN Computing and Network Infrastructure for Controls (CNIC)

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    Over the last few years modern accelerator and experiment control systems have increasingly been based on commercial-off-the-shelf products (VME crates, PLCs, SCADA systems, etc.), on Windows or Linux PCs, and on communication infrastructures using Ethernet and TCP/IP. Despite the benefits coming with this (r)evolution, new vulnerabilities are inherited too: Worms and viruses spread within seconds via the Ethernet cable, and attackers are becoming interested in control systems. Unfortunately, control PCs cannot be patched as fast as office PCs. Even worse, vulnerability scans at CERN using standard IT tools have shown that commercial automation systems lack fundamental security precautions: Some systems crashed during the scan, others could easily be stopped or their process data be altered. During the two years following the presentation of the CNIC Security Policy at ICALEPCS2005, a "Defense-in-Depth" approach has been applied to protect CERN's control systems. This presentation will give a review of its thorough implementation and its deployment. Particularly, measures to secure the controls network and tools for user-driven management of Windows and Linux control PCs will be discusse

    The CERN Detector Safety System for the LHC Experiments

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    The Detector Safety System (DSS), currently being developed at CERN under the auspices of the Joint Controls Project (JCOP), will be responsible for assuring the protection of equipment for the four LHC experiments. Thus, the DSS will require a high degree of both availability and reliability. After evaluation of various possible solutions, a prototype is being built based on a redundant Siemens PLC front-end, to which the safety-critical part of the DSS task is delegated. This is then supervised by a PVSS SCADA system via an OPC server. The PLC front-end is capable of running autonomously and of automatically taking predefined protective actions whenever required. The supervisory layer provides the operator with a status display and with limited online reconfiguration capabilities. Configuration of the code running in the PLCs will be completely data driven via the contents of a "Configuration Database". Thus, the DSS can easily adapt to the different and constantly evolving requirements of the LHC experiments during their construction, commissioning and exploitation phases.Comment: Talk from the 2003 Computing in High Energy and Nuclear Physics (CHEP03), La Jolla, Ca, USA, March 2003, 5 pages, PDF. PSN THGT00

    Severe discrepancies between experiment and theory in the superconducting proximity effect

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    The superconducting proximity effect is investigated for SN double layers in a regime where the resulting transition temperature T_{c} does not depend on the mean free paths of the films and, within limits, not on the transparency of the interface. This regime includes the thin film limit and the normalized initial slope S_{sn}= (d_{s}/T_{s})|dT_{c}/dd_{n}|. The experimental results for T_{c} are compared with a numerical simulation which was recently developed in our group. The results for the SN double layers can be devided into three groups: (i) When N = Cu, Ag, Au, Mg a disagreement between experiment and theory by a factor of the order of three is observed, (ii) When N = Cd, Zn, Al the disagreement between experiment and theory is reduced to a factor of about 1.5, (iii) When N = In, Sn a reasonably good agreement between experiment and theory is observed

    Methodological Advances to Study Contaminant Biotransformation: New Prospects for Understanding and Reducing Environmental Persistence?

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    Complex microbial communities in environmental systems play a key role in the detoxification of chemical contaminants by transforming them into less active metabolites or by complete mineralization. Biotransformation, i.e., transformation by microbes, is well understood for a number of priority pollutants, but a similar level of understanding is lacking for many emerging contaminants encountered at low concentrations and in complex mixtures across natural and engineered systems. Any advanced approaches aiming to reduce environmental exposure to such contaminants (e.g., novel engineered biological water treatment systems, design of readily degradable chemicals, or improved regulatory assessment strategies to determine contaminant persistence a priori) will depend on understanding the causal links among contaminant removal, the key driving agents of biotransformation at low concentrations (i.e., relevant microbes and their metabolic activities), and how their presence and activity depend on environmental conditions. In this Perspective, we present the current understanding and recent methodological advances that can help to identify such links, even in complex environmental microbiomes and for contaminants present at low concentrations in complex chemical mixtures. We discuss the ensuing insights into contaminant biotransformation across varying environments and conditions and ask how much closer we have come to designing improved approaches to reducing environmental exposure to contaminants

    A Novel Use of Concussion Protocols in the Management of the Cognitive Effects in Long Haul COVID

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    Some individuals diagnosed with Long Haul COVID (lCOVID) have concurrently reported cognitive issues such as confusion, forgetfulness, decreased attention time, and difficulty focusing. This series of symptoms is termed brain fog. PURPOSE: Patients with reports of brain fog may benefit from the utilization of protocols associated with concussion rehabilitation to reduce the effects of confusion, frustration, and difficulty focusing on exercise instructions. This study looked at the novel application of the concussion rehabilitation protocol to mitigate the cognitive issues linked to brain fog through a course of physical therapy for lCOVID recovery. METHODS: This case report tracked a 57-year-old female who was being seen for cardiorespiratory and strengthening rehabilitation after a diagnosis of lCOVID. The patient underwent a pre- and post-Mini-Mental State Exam (MMSE) as well as a treatment satisfaction survey at the end of the study. Oxygen saturation was measured before, during, and after each date of visit. During the initial 10-week course of physical therapy, she expressed issues with confusion and occasional difficulty understanding tasks needed in physical therapy. A neurologist diagnosed her with brain fog and suggested that concussion protocols that help individuals with similar cognitive symptoms might facilitate her rehabilitation process. The plan of care was overhauled to incorporate salient features of the concussion rehab protocol and the patient continued with the revised care for another 6 weeks, resulting in a total care episode of 16 weeks. RESULTS: The patient completed 16 weeks of therapy with improvement in baseline to exercise O2 saturation with no noted decline during the strengthening and cardiovascular phase. The patient reported high satisfaction in the ability of the revised treatment plan from week 10 onwards in terms of helping her symptoms and her condition. The patient also reported no associated side effects with the concussion rehabilitation protocol. The patient also stated that there was no difficulty, no inconvenience, and no dissatisfaction associated with the use of the revised plan of care. She stated that the overall treatment plan challenged her, reporting fatigue and tiredness towards both the physical and mental aspects of the therapy. There was no noted cognitive impairment using the MMSE before and after the course of therapy. CONCLUSION: The utilization of the Concussion Rehabilitation Protocol is a no-cost, simple-to-integrate addition to lCOVID physical therapy recovery that may help individuals concurrently deal with brain fog. Individuals diagnosed with brain fog will benefit from concussion protocol hallmarks such as the provision of extended rest periods, when necessary, compensatory techniques when confused, facilitating exercise utilizing one to two-step instructions, monitoring of mood and symptoms, and education towards an optimistic full recovery from symptoms

    Effects of warming and drought on potential N2O emissions and denitrifying bacteria abundance in grasslands with different land-use

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    Increased warming in spring and prolonged summer drought may alter soil microbial denitrification. We measured potential denitrification activity and denitrifier marker gene abundances (nirK, nirS, nosZ) in grasslands soils in three geographic regions characterized by site-specific land-use indices (LUI) after warming in spring, at an intermediate sampling and after summer drought. Potential denitrification was significantly increased by warming, but did not persist over the intermediate sampling. At the intermediate sampling, the relevance of grassland land-use intensity was reflected by increased potential N2O production at sites with higher LUI. Abundances of total bacteria did not respond to experimental warming or drought treatments, displaying resilience to minor and short-term effects of climate change. In contrast, nirS- and nirK-type denitrifiers were more influenced by drought in combination with LUI and pH, while the nosZ abundance responded to the summer drought manipulation. Land-use was a strong driver for potential denitrification as grasslands with higher LUI also had greater potentials for N2O emissions. We conclude that both warming and drought affected the denitrifying communities and the potential denitrification in grassland soils. However, these effects are overruled by regional and site-specific differences in soil chemical and physical properties which are also related to grassland land-use intensit

    Robotic Technologies for Surveying Habitats and Seeking Evidence of Life: Results from the 2004 Field Experiments of the "Life in the Atacama" Project

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    The Chilean Atacama Desert is the most arid region on Earth and in several ways analogous to Mars. Evidence suggests that the interior of the Atacama is lifeless, yet where the desert meets the Pacific coastal range dessication-tolerant microorganisms are known to exist. The gradient of biodiversity and habitats in the Atacama's subregions remain unexplored and are the focus of the Life in the Atacama project. Our field investigation attempts to bring further scientific understanding of the Atacama as a habitat for life through the creation of robotic astrobiology. This involves capabilities for autonomously traversing hundreds of kilometers while deploying sensors to survey the varying geologic and biologic properties of the environment, Fig. 1. Our goal is to make genuine discoveries about the limits of life on Earth and to generate knowledge about life in extreme environments that can be applied to future planetary missions. Through these experiments we also hope to develop and practice the methods by which a rover might best be employed to survey desert terrain in search of the habitats in which life can survive, or may have in the past

    Quantum control of hybrid nuclear-electronic qubits

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    Pulsed magnetic resonance is a wide-reaching technology allowing the quantum state of electronic and nuclear spins to be controlled on the timescale of nanoseconds and microseconds respectively. The time required to flip either dilute electronic or nuclear spins is orders of magnitude shorter than their decoherence times, leading to several schemes for quantum information processing with spin qubits. We investigate instead the novel regime where the eigenstates approximate 50:50 superpositions of the electronic and nuclear spin states forming "hybrid nuclear-electronic" qubits. Here we demonstrate quantum control of these states for the first time, using bismuth-doped silicon, in just 32 ns: this is orders of magnitude faster than previous experiments where pure nuclear states were used. The coherence times of our states are five orders of magnitude longer, reaching 4 ms, and are limited by the naturally-occurring 29Si nuclear spin impurities. There is quantitative agreement between our experiments and no-free-parameter analytical theory for the resonance positions, as well as their relative intensities and relative Rabi oscillation frequencies. In experiments where the slow manipulation of some of the qubits is the rate limiting step, quantum computations would benefit from faster operation in the hybrid regime.Comment: 20 pages, 8 figures, new data and simulation

    Role of Coulomb interaction in the superconducting properties of CaC6 and H under pressure

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    Superconductivity in intercalated graphite CaC6 and H under extreme pressure, in the framework of superconducting density functional theory, is discussed. A detailed analysis on how the electron-phonon and electron-electron interactions combine together to determine the superconducting gap and critical temperature of these systems is presented. In particular, we discuss the effect on the calculated Tc of the anisotropy of the electron-phonon interaction and of the different approximations for screening the Coulomb repulsion. These results contribute to the understanding of multigap and anisotropic superconductivity, which has received a lot of attention since the discovery of MgB2, and show how it is possible to describe the superconducting properties of real materials on a fully ab-initio basis.Comment: 13 pages, 5 figure
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