| 17441. |
- Rubiano Berna, Jorge Enrique, et al.
(författare)
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Theoretical Study of Systems Composed of Low Consistency Refining and Pressure Screening
- 2018
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Ingår i: IMPC 2018. - Trondheim, Norway.
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Konferensbidrag (refereegranskat)abstract
- The main objective of this work is to study the LC rening of mechanical pulps from system-design point of view. Mathematical models that describe bre length distribution changes were used to develop aframework capable of simulating LC rening { pressure screening systems. Specically, pressure screening models and comminution models for LC rening that are available in literature together with heuristic and a developed correlation to predict rening power were implemented in MATLAB Simulink toolbox.Later on, this same environment was used to simulate three basic rening systems found in TMP mills. In this study, each considered system was composed of a single rener and single pressure screen arranged in dierent congurations. Performance curves of length-weighed mean bre length were generated from simulation results andused to assess each system behaviour in terms of rener gap, reject ratio and rener power. The impact of some design aspects such as rener size, recirculation and reject ratio were also described. Furthermore,comparisons between systems and some basic recommendations and suggested applications are made. This theoretical framework was compared to industrial-scale data from a TMP mill sub-system. Simulation results showed good agreement with real data, where relative errors between 6-18% on the predicted variables were observed.
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| 17442. |
- Ruck, Christian, et al.
(författare)
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Capsulotomy for Obsessive-Compulsive Disorder : long term follow up of 25 patients
- 2008
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Ingår i: Archives of General Psychiatry. - : American Medical Association (AMA). - 0003-990X .- 1538-3636. ; 65:8, s. 914-922
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Tidskriftsartikel (refereegranskat)abstract
- Abstract Context: Capsulotomy is sometimes used as a treatment of last resort in severe and treatment refractory cases of Obsessive-Compulsive Disorder (OCD). Objective: To evaluate the long-term efficacy and safety of capsulotomy in OCD. Design: Non-controlled long-term follow-up trial (mean 10.9 years after surgery). Setting: University hospital referral center. Patients: 25 consecutive OCD patients having undergone capsulotomy between the years 1988 and 2000. Intervention: Unilateral or bilateral capsulotomy. Lesions were created either by conventional heating or by gamma-radiation (radiosurgery). Main Outcome Measure: Yale-Brown Obsessive-Compulsive Rating Scale (Y-BOCS). Results: Mean Y-BOCS was 34 preoperatively and dropped to 18 at long-term follow-up (p<0.0001). Response (defined as ≥ 35 % reduction at long-term compared to baseline) was seen in 12 patients at long-term. Eight patients were in remission (Y-BOCS < 16) at long-term follow-up. Response rates did not differ between surgical method. A mean weight gain of 6 kg was reported in the first postoperative year. Ten patients were considered to sufferer from significant problems in the area of executive functioning, apathy or disinhibition. Six of these ten patients had either had high doses of radiation or multiple surgical procedures. Our MRI analysis of 11 patients suggests that the OCD symptom reduction may be increased by reducing the lateral extension of the lesions, and a reduction in the medial and posterior extension may limit the risk of side effects, that is, smaller lesions may produce better results. Conclusions: Capsulotomy is effective in reducing OCD symptoms. There is a substantial risk of side effects and the risk may vary between surgical methods. Our findings suggest that smaller lesions are safer and that high radiation doses and multiple procedures should be avoided.
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| 17443. |
- Ruden, P.P., et al.
(författare)
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Modeling of Band-to-band tunneling transitions during drift in Monte Carlo transport simulations
- 2000
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Ingår i: Journal of Applied Physics. - : AIP Publishing. - 0021-8979 .- 1089-7550. ; 88:3, s. 1488-1493
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Tidskriftsartikel (refereegranskat)abstract
- The conventional method of semiconductor charge carrier transport investigations using full band ensemble Monte Carlo simulations is extended to allow for tunneling between bands during accelerated drift of the carriers. The essentially classical picture of transport, as simulated, is preserved by implementing a stochastic selection of the band index of the initial state of each scattering process associated with phonons, with impurities, or with impact ionization. Relative probabilities for the band assignment are calculated from the overlap integrals of the cell-periodic parts of Bloch wave functions belonging to different bands, for k-vectors along the carrier k-space trajectory between successive scattering events. As an example, the method is applied to Monte Carlo transport simulations for holes in 4H SiC in a homogeneous applied electric field. Tunneling between valence bands during the drift phases is shown to have a significant impact on the carrier energy distributions when large electric fields are applied, and on physical parameters that directly depend on the carrier energy, such as the hole initiated impact ionization coefficient.
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| 17444. |
- Rudnik, Jana, et al.
(författare)
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Differential expression of nitric oxide synthases (NOS 1-3) in human skeletal muscle following exercise countermeasure during 12 weeks of bed rest.
- 2004
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Ingår i: The F A S E B Journal. - 0892-6638. ; 18:11, s. 1228-1230
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Tidskriftsartikel (refereegranskat)abstract
- Nitric oxide (NO) generated from NO synthases mediates normal skeletal muscle functions. Biosynthesis of NO apparently is linked to muscle activity, but the distribution and expression of the three major NO synthase 1-3 isoforms under conditions of extended muscle disuse and exercise are still unclear. Our aim was to elucidate whether protein levels and the cellular or subcellular localization patterns of NO synthases underwent significant changes in a mixed fast/slow and slow type skeletal muscle after prolonged disuse in a long-term bed rest study, a useful experimental paradigm of simulated microgravity in ground-based space research. We examined whether resistance exercise performed regularly as a countermeasure to progressive atrophy within 12 wk of strict bed rest would support expression of one or more isoforms of NOS, thereby maintaining normal skeletal muscle functions during immobilization in clinical settings or in human spaceflight.
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| 17445. |
- Rudqvist, Anders, et al.
(författare)
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Resistencia comunitaria en Colombia : Los cabildos caucanos y su guardia indígena
- 2013
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Ingår i: Papel Político. - Bogotá : Universidad Javeriana. - 0122-4409. ; 18:2, s. 515-548
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Tidskriftsartikel (refereegranskat)abstract
- En contextos sociales afligidos por altas intensidades de conflicto y violencia, las comunidades afrodescendientes, campesinas e indígenas en Colombia han dado diferentes significados propios a la resistencia civil que responden a las necesidades de los contextos determinados y las distintas formas de violencia que los aquejan. La región del Cauca se distingue por su tradición de organización indígena y por su resistencia contra los terratenientes y el Estado. La resistencia civil para el movimiento indígena es ejercicio de autonomía e incluye varios elementos como la participación comunitaria y política, la Guardia Indígena y las asambleas permanentes. Debido al trabajo de organización las comunidades son capaces de dar una respuesta organizada frente a situaciones de combate en la zona. La Guardia Indígena está controlada por las autoridades indígenas, nace por la necesidad de preservar la integridad y autonomía del territorio y defender los derechos de los pueblos indígenas, respetar y difundir la cultura y el derecho autóctono. Frente a la guerrilla la Asociación de Cabildos del Norte de Cauca reconoce que ésta ha sido históricamente otra forma de resistencia al Estado y defensora de los derechos de los pueblos indígenas y le demanda respeto a su cultura, costumbres, tierras y territorios.
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| 17446. |
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| 17447. |
- Ruete, Alejandro, et al.
(författare)
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Contrasting long-term effects of transient anthropogenic edges and forest fragment size on generalist and specialist deadwood-dwelling fungi
- 2017
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Ingår i: Journal of Applied Ecology. - : Wiley. - 0021-8901 .- 1365-2664. ; 54:4, s. 1142-1151
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Tidskriftsartikel (refereegranskat)abstract
- Forests are becoming increasingly fragmented world-wide, creating forest patches with reduced area and greater exposure to human land uses along fragment edges. In this study, we predict the future impacts of anthropogenic edges and fragment size on the future occupancy of deadwood-dwelling fungi in boreal old-growth forest fragments. We used Bayesian models fitted to empirical data to predict 40years of occupancy dynamics of logs by a group of old-growth forest indicator fungi and two common fungi under different scenarios of clear-cutting in adjacent forest (0%, 25%, 50% and 100%) and fragment sizes (1-20ha). Small fragment size (1-314ha) and intensified forestry with 50-100% clear-cutting of forest around old-growth forest fragments lead to lower predicted occupancy of old-growth indicator fungi while common generalist species like Fomitopsis pinicola increased. There was a trade-off between fragment size and management, where increasing fragment size buffered the negative long-term effects from increased adjacent clear-cutting. These changes in fungal occupancy at the edge should be accounted for when working towards conservation targets for protected areas, such as the Aichi target 11.Synthesis and applications. Preserve what is left - but buffer for change. Small forest fragments often represent the last vestiges of high habitat quality (i.e. species, structures) in managed forest landscapes. As effective area-based conservation measures for the long-term occupancy of old-growth fungi, small fragments need to be managed to protect species from degrading transient edge effects. Management should focus on increasing the size of conservation areas with permanent buffer zones. Alternatively, non-simultaneous adjacent clear-cutting in a way that reduces the edge effect over time (i.e. dynamic buffers) may increase the effective area and improve performance of set-asides in protecting species of special concern for conservation. Preserve what is left - but buffer for change. Small forest fragments often represent the last vestiges of high habitat quality (i.e. species, structures) in managed forest landscapes. As effective area-based conservation measures for the long-term occupancy of old-growth fungi, small fragments need to be managed to protect species from degrading transient edge effects. Management should focus on increasing the size of conservation areas with permanent buffer zones. Alternatively, non-simultaneous adjacent clear-cutting in a way that reduces the edge effect over time (i.e. dynamic buffers) may increase the effective area and improve performance of set-asides in protecting species of special concern for conservation.
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| 17448. |
- Ruggiero, A., et al.
(författare)
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Accurate Measurement of Reciprocating Kinetic Friction Coefficient through Automatic Detection of the Running-In
- 2020
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Ingår i: IEEE Transactions on Instrumentation and Measurement. - : Institute of Electrical and Electronics Engineers Inc.. - 0018-9456 .- 1557-9662. ; 69:5, s. 2398-2407
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Tidskriftsartikel (refereegranskat)abstract
- Tribological tests are adopted to estimate the kinetic friction coefficient (COF) of the material of interest according to the American Society for Testing and Materials (ASTM) standard. Typically, for the measurement process, several replicas, as well as a postprocessing data treatment, are necessary to take into account the observed casual variability of the measurand. This article describes a statistical approach aiming to highlight the running-in phase and the most significant time intervals during the steady-state for each test replica. A two-steps procedure based on the adoption of the bootstrap method allows the automatic detection of the running-in time interval and the outlier filtering of the steady-state. Experimental activity has been carried out by performing multiple tests through the ball-on-flat tribometer in order to verify the improvement allowed by the authors' proposal about the dry friction COF measurement in terms of both accuracy and repeatability. © 1963-2012 IEEE.
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| 17449. |
- Ruhle, S A, S A, et al.
(författare)
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“To work, or not to work, that is the question” : Recent trends and avenues for research on presenteeism
- 2020
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Ingår i: European Journal of Work and Organizational Psychology. - 1359-432X .- 1464-0643. ; 29:3, s. 344-363
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Tidskriftsartikel (refereegranskat)abstract
- This position paper brings together recent and emerging developments in the field of presenteeism. A critical synthesis of the evidence is needed due to persisting conceptual and methodological challenges as well as the increased volume of research in the field.This paper integrate semerging evidence and critical thinking into three areas: (1) concept, (2) measurement and methodological issues, and (3) the context of presenteeism. First, due to the variety of existing definitions, competing understandings, as well as the notion of positive presenteeism, it is important to reconsider the notion of presenteeism. Second, it is important to reflect on the measurement of the act of presenteeism and the productivity loss associated with that. Third,following the call to investigate presenteeism in specific contexts,it is important to explain the social, occupational, cross-cultural aspects, as well as the contemporary workplace changes. Based on this critical synthesis, we conclude by identifying recommendations for future research on presenteeism.
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| 17450. |
- Ruiz, Marj A, et al.
(författare)
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Factor Structure and Correlates of the Dissociative Experiences Scale in a Large Offender Sample
- 2008
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Ingår i: Assessment. - : SAGE Publications. - 1073-1911 .- 1552-3489. ; 15:4, s. 511-521
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Tidskriftsartikel (refereegranskat)abstract
- The authors examined the psychometric properties, factor structure, and construct validity of the Dissociative Experiences Scale ( DES) in a large offender sample (N = 1,515). Although the DES is widely used with community and clinical samples, minimal work has examined offender samples. Participants were administered self-report and interview measures, and a subsample was followed longitudinally to determine criminal and violent recidivism. The DES exhibited good psychometric properties, but an identified three-factor structure was of questionable replicability. Moreover, the DES factors displayed no evidence of differential correlates. DES total scores were correlated with trauma-related variables even after controlling for negative affectivity. Total scores were related to measures of antisocial behavior and aggression but did not predict recidivism. These findings support the reliability and construct validity of the DES in offenders but raise questions regarding the clinical utility of the DES factor scores above and beyond that of the total score.
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