1,436 research outputs found

    Physics Benchmarks with the VELO Pixel Upgrade

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    The LHCb Experiment at the LHC is successfully performing precision measurements primarily in the area of flavour physics. The collaboration is preparing an upgrade that will start taking data in 2021 with a trigger-less readout at five times the current luminosity. The vertex locator has been crucial in the success of the experiment and will continue to be so for the upgrade. It will be replaced by a hybrid pixel detector and this paper discusses the performance benchmarks of the upgraded detector. Despite the challenging experimental environment, the vertex locator will maintain or improve upon its benchmark figures compared to the current detector. Finally the long term plans for LHCb, beyond those of the upgrade currently in preparation, are discussed

    Structure and hydrogen bonding of the hydrated selenite and selenate ions in aqueous solution

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    The structure and hydrogen bonding of the hydrated selenite, SeO32-, and selenate, SeO42-, ions have been studied in aqueous solution by large angle X-ray scattering (LAXS), EXAFS and double difference infrared (DDIR) spectroscopy. The mean Se-O bond distances are 1.709(2) and 1.657(2) angstrom, respectively, as determined by LAXS, and 1.701(3) and 1.643(3) angstrom by EXAFS. These bond distances are slightly longer than the mean distances found in the solid state, 1.691 and 1.634 angstrom, respectively. The structures of HSeO3-, H2SeO3 and HSeO4- in aqueous solution have been determined by EXAFS giving the same Se-O bond distances as for the selenite and selenate ions, respectively. The mean Se center dot center dot center dot O-w distance to the water molecules hydrogen binding to selenite oxygens is 3.87(2) angstrom, and it is 4.36(8) angstrom to those clustered outside the lone electron-pair. The selenate ion has a symmetric hydration shell with only one Se center dot center dot center dot O-w distance, 3.94(2) angstrom. The mean Se-O center dot center dot center dot O-w angle in the hydrated selenite ion is 114.5, and the large temperature factor of the Se. Ow distance strongly indicates equilibrium between two and three water molecules hydrogen bound to the selenite oxygens. The mean Se- O. Ow angle in the hydrated selenate ion is 120 which strongly indicates that two water molecules hydrogen bind to the selenate oxygens. The DDIR spectra show peaks for the affected water bound to the selenite and selenate ions at 2491 +/- 2 and 2480 +/- 39 cm(-1), respectively, compared to 2509 cm(-1) in pure water. This shows that the selenite and selenate ions shall be regarded as weak structure makers

    Double Secret Protection: Bridging Federal and State Law To Protect Privacy Rights for Telemental and Mobile Health Users

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    Mental health care in the United States is plagued by stigma, cost, and access issues that prevent many people from seeking and continuing treatment for mental health conditions. Emergent technology, however, may offer a solution. Through telemental health, patients can connect with providers remotely—avoiding stigmatizing situations that can arise from traditional healthcare delivery, receiving more affordable care, and reaching providers across geographic boundaries. And with mobile health technology, people can use smart phone applications both to self-monitor their mental health and to communicate with their doctors. But people do not want to take advantage of telemental and mobile health unless their privacy is protected. After evaluating the applicability of current health information privacy law to these new forms of treatment, this Note proposes changes to the federal regime to protect privacy rights for telemental and mobile health users

    Hydration of oxo anions

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    The structure and dynamics of several hydrated oxo anions were studied using multiple methodologies. Aqueous solutions of sulfate, sulfite, thiosulfate, peroxysulfate, selenite, selenate, hypochlorite, chlorite, chlorate, perchlorate, bromate, iodate and periodate salts were studied using large angle X-ray scattering (LAXS) and extended X-ray absorption fine structure (EXAFS) spectroscopy. The thiosulfate, selenite and selenate salts were also studied using double difference infrared spectroscopy (DDIR). Moreover, the sulfite, sulfate thiosulfate, chlorite, chlorate and perchlorate ions were simulated using quantum mechanical charge field (QMCF). The periodate ion was shown to have only meta configuration in aqueous solution, while both meta and ortho configurations are present in solid state. The studies showed that the anions could be placed in two main groups, one with asymmetric and another with symmetric hydration. In the asymmetric group consisting of sulfite, selenite, chlorite and chlorate ions where the lone electron-pair of the central atom showed substantially weaker interaction with a longer distance to the water molecules near the lone electron-pair than to those near the oxygens bound to the ion. The symmetric group, sulfate, peroxysulfate, selenate, perchlorate, and periodate ions showed a symmetric interaction with one M-(

    Structure and water exchange of hydrated oxo halo ions in aqueous solution using QMCF MD simulation, large angle X-ray scattering and EXAFS

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    Theoretical ab initio quantum mechanical charge field molecular dynamics (QMCF MD) has been applied in conjunction with experimental large angle X-ray scattering (LAXS) and EXAFS measurements to study structure and dynamics of the hydrated oxo chloro anions chlorite, ClO2-, chlorate, ClO3-, and perchlorate, ClO4-. In addition, the structures of the hydrated hypochlorite, ClO-, bromate, BrO3-, iodate, IO3- and metaperiodate, IO4-, ions have been determined in aqueous solution by means of LAXS. The structures of the bromate, metaperiodate, and orthoperiodate, H2IO63-, ions have been determined by EXAFS as solid sodium salts and in aqueous solution as well. The results show clearly that the only form of periodate present in aqueous solution is metaperiodate. The Cl-O bond distances in the hydrated oxo chloro anions as determined by LAXS and obtained in the QMCF MD simulations are in excellent agreement, being 0.01-0.02 angstrom longer than in solid anhydrous salts due to hydration through hydrogen bonding to water molecules. The oxo halo anions, all with unit negative charge, have low charge density making them typical structure breakers, thus the hydrogen bonds formed to the hydrating water molecules are weaker and more short-lived than those between water molecules in pure water. The water exchange mechanism of the oxo chloro anions resembles those of the oxo sulfur anions with a direct exchange at the oxygen atoms for perchlorate and sulfate. The water exchange rate for the perchlorate ion is significantly faster, tau(0.5) = 1.4 ps, compared to the hydrated sulfate ion and pure water, tau(0.5) = 2.6 and 1.7 ps, respectively. The angular radial distribution functions show that the chlorate and sulfite ions have a more complex water exchange mechanism. As the chlorite and chlorate ions are more weakly hydrated than the sulfite ion the spatial occupancy is less well-defined and it is not possible to follow any well-defined migration pattern as it is difficult to distinguish between hydrating water molecules and bulk water in the region close to the ions

    Control Problems in Wastewater Treatment Plants

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    Effects of deposition temperature on the mechanical and structural properties of amorphous Al-Si-O thin films prepared by RF magnetron sputtering

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    Aluminosilicate (Al-Si-O) thin films containing up to 31 at. % Al and 23 at. % Si were prepared by reactive RF magnetron co-sputtering. Mechanical and structural properties were measured by indentation and specular reflectance infrared spectroscopy at varying Si sputtering target power and substrate temperature in the range 100 to 500 {\deg}C. It was found that an increased substrate temperature and Al/Si ratio give denser structure and consequently higher hardness (7.4 to 9.5 GPa) and reduced elastic modulus (85 to 93 GPa) while at the same time lower crack resistance (2.6 to 0.9 N). The intensity of the infrared Si-O-Si/Al asymmetric stretching vibrations shows a linear dependence with respect to Al concentration. The Al-O-Al vibrational band (at 1050 cm-1) shifts towards higher wavenumbers with increasing Al concentration which indicates a decrease of the bond length, evidencing denser structure and higher residual stress, which is supported by the increased hardness. The same Al-O-Al vibrational band (at 1050 cm-1) shifts towards lower wavenumber with increasing substrate temperature indicating an increase in the of the average coordination number of Al.Comment: Preprin

    Arbetsmiljöarbete och effekter en kunskapsöversikt

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    Work environment improvements and effects a literature review This report addresses the question 'Do work-environment improvements have any effects?' The aim was to produce a summary of knowledge that includes the methodological problems of measuring and evaluating effects, as well as literature reviews of effects from work environment improvement efforts on musculoskeletal health, health promotion, and economy. Results show that published literature reviews do not give unambiguous support for health benefits of interventions against musculoskeletal problems, when only studies using natural science criteria with experimental or quasi-experimental design are included. There are, on the other hand, many case studies in the so called 'grey' literature that report positive effects. Further, results show that health promotion interventions, and especially physical activity, have a positive effect on low back pain. Workplace interventions to increase physical activity are effective and lead to increased physical activity amongst employees. More studies are needed, however, at the organisational level. There is some support for the profitability of work-environment investments at the organisational level; even though there are few studies and methodological problems. The review also indicates that the financial benefits come mostly from quality and productivity improvements and, to a lesser extent from reductions in costs related to sickness absenteeism. While more recent literature reviews of the effects of health promotion interventions seem to show a stronger effect than older studies, comparisons of older versus more recent studies of interventions against musculoskeletal problems give a more ambiguous picture. Often, the focus of these reviews is on study design with less priority on the quality of the interventions themselves. Multifactorial interventions are particularly difficult to evaluate. At the same time, many studies and research reviews emphasise the need for multifactorial approaches as necessary for successful intervention. Inclusion criteria in literature reviews that only consider experimental designs in organisational interventions exclude studies with good interventions that can't be evaluated with traditional experimental methods. Difficulties in proving the effectiveness of interventions depends on views of what constitutes good scientific quality in the studies. This shows a need for a critical examination of the assumptions used for knowledge generation in this area. Conclusions are that work-environment improvement efforts have effects that are clear in some cases but are difficult to show in others. Effect evaluation poses large methodological challenges. These difficulties are considered to be an important cause of the lack of clear evidence, especially in the area of interventions against musculoskeletal problems. There is a need for new non-experimental research strategies that are suited to today's complex systems and an increased focus on practical, well conducted multifactorial interventions. Key words: Intervention, health promotion, ergonomics, economy, methodology, researchDetta arbete har inriktats mot frågeställningen om arbetsmiljöarbete har några effekter. Syftet har varit att göra en kunskapssammanställning som omfattar en beskrivning och problematisering av metodiken att mäta eller utvärdera effekter, samt litteraturöversikter om vad arbetsmiljöarbete har för belastningsergonomiska, hälsofrämjande och ekonomiska effekter. Resultaten visar att publicerade litteraturöversikter inte ger säkra belägg för att belastningsergonomiska interventioner har effekter på besvärsförekomst, i de fall enbart studier inkluderats utifrån naturvetenskapliga kriterier med krav på experimentell eller kvasi-experimentell metodik. Däremot finns ett flertal fallstudier och så kallad grå litteratur som i högre grad rapporterar positiva effekter. Vidare framgår det att hälsofrämjande interventioner, och speciellt fysisk aktivitet har en positiv effekt på ländryggsbesvär. Interventioner på arbetsplatser för att öka den fysiska aktiviteten är effektiva och ger en ökad fysisk aktivitet hos arbetstagarna. Fler studier behövs emellertid på organisationsnivå. Det finns visst belägg för att arbetsmiljösatsningar ofta är lönsamma på organisationsnivå, även om studierna är få och uppvisar metodbrister. Det finns flera indikationer på att lönsamheten i huvudsak härrör från produktivitets- och kvalitetsförbättringar, och i mindre grad från minskade frånvarokostnader. Nya litteraturöversikter om hälsofrämjande interventioner tycks uppvisa starkare effekter än gamla, medan jämförelser mellan äldre och nyare studier om belastningsergonomiska interventioner ger en mer mångtydig bild. Ofta ligger fokus på utvärderingsdesign, samtidigt som kvaliteten hos interventionens genomförande och utformning i sig inte ges samma prioritet. Interventioner med multifaktoriella insatser blir synnerligen svåra och komplexa att utvärdera, samtidigt som det i många studier och forskningsöversikter betonas att en förutsättning för framgång i förändringsarbetet är att man arbetar med en mångfald av insatser. Inklusionskriterier i litteraturöversikter som förutsätter experimentella upplägg i organisationsinterventioner selekterar bort studier med goda interventioner som inte kan utvärderas med traditionella metoder. Svårigheten att identifiera effekter av interventioner bedöms bero på synen om vad som utmärker god vetenskaplig kvalitet hos studier. Detta visar på behovet att närmare kritiskt granska förutsättningarna för kunskapsbildning inom området. Slutsatsen är att arbetsmiljöarbete i vissa fall har effekter men att det i andra fall är svårt att påvisa effekter. Effektutvärdering innebär stora metodologiska svårigheter. Dessa svårigheter bedöms vara en viktig orsak till bristen på underlag, speciellt inom det belastningsergonomiska området. Det finns ett stort behov av nya icke experimentella undersökningsstrategier som är anpassade till dagens komplexa system, såväl som ett behov av starkare fokus på praktiskt väl genomförda multifaktoriella interventioner

    Decision Making Improvement for Disaster Risk Management (DRM) through technological support

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    The workshop “Decision Making Improvement for Disaster Risk Management (DRM) through technological support” was held in Bucharest, Romania on 16th of October 2019, part of the 4th DRMKC Annual Seminar. The key objective of the session was to increase the collaboration with national/regional/local authorities and other institutions, aligning the development of the tools to the needs and concerns expressed at local/national level. To accomplish its objective, the workshop brought together technical and scientific experts with end users of the platforms, who have faced the main challenges related to data, knowledge and institutional practices while offering technological support for DRM. Showcases and feedback from national authorities and institutions were presented, as they were experienced when using the platforms presented in the session: the DRMKC Risk Data Hub, GRRASP and RAPID-N. The session was divided in two parts, in the first it was presented the general characteristics and functionalities of the platforms, followed in the second part by showcases of using these platforms in various applications by the local authorities and institutions.JRC.E.1-Disaster Risk Managemen

    The electronic-structure origin of the anisotropic thermopower of nanolaminated Ti3SiC2 determined by polarized x-ray spectroscopy and Seebeck measurements

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    Nanolaminated materials exhibit characteristic magnetic, mechanical, and thermoelectric properties, with large contemporary scientific and technological interest. Here, we report on the anisotropic Seebeck coefficient in nanolaminated Ti3SiC2 single-crystal thin films and trace the origin to anisotropies in element-specific electronic states. In bulk polycrystalline form, Ti3SiC2 has a virtually zero Seebeck coefficient over a wide temperature range. In contrast, we find that the in-plane (basal ab) Seebeck coefficient of Ti3SiC2, measured on single-crystal films has a substantial and positive value of 4-6 muV/K. Employing a combination of polarized angle-dependent x-ray spectroscopy and density functional theory we directly show electronic structure anisotropy in inherently nanolaminated Ti3SiC2 single-crystal thin films as a model system. The density of Ti 3d and C 2p states at the Fermi level in the basal ab-plane is about 40 % higher than along the c-axis. The Seebeck coefficient is related to electron and hole-like bands close to the Fermi level but in contrast to ground state density functional theory modeling, the electronic structure is also influenced by phonons that need to be taken into account. Positive contribution to the Seebeck coefficient of the element-specific electronic occupations in the basal plane is compensated by 73 % enhanced Si 3d electronic states across the laminate plane that give rise to a negative Seebeck coefficient in that direction. Strong phonon vibration modes with three to four times higher frequency along the c-axis than along the basal ab-plane also influence the electronic population and the measured spectra by the asymmetric average displacements of the Si atoms. These results constitute experimental evidence explaining why the average Seebeck coefficient of Ti3SiC2 in polycrystals is negligible over a wide temperature range.Comment: 13 pages, 6 figures; http://prb.aps.org/abstract/PRB/v85/i19/e19513
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