456 research outputs found

    Recovery technologies for materials in landfills

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    Europe hosts more than 500,000 landfills of which 90% are non-sanitary and around 80% essentially contain Urban Solid Waste (https://www.eurelco.org/infographic). Urban landfills (UL) and extractive (mining and metallurgical) industry residues (EIR) are potential sources of materials that, if recovered, can contribute to the circularity of economy. Among other factors, technology plays one essential role in the viability of landfill mining projects (Krook, et al, 2012). The methods for mapping landfills, sampling and characterizing waste, the readiness of technologies, the optimization of technologies and their combination in treatment and recovery schemes, their applicability, costs and environmental impacts effect the valorization of waste from landfills. This report addresses Deliverable 1.1 “Recovery technologies for materials in landfills” developed by Working Group 2 of COST Action “Mining the European Anthroposphere” (MINEA). MINEA aims to quantify and assess the material resources and reserves in the Anthroposphere and consolidate existing knowledge related to the exploration, evaluation, classification and recovery of materials in anthropogenic deposits and waste flows. This report integrates the activities of the MINEA WG2 in the 1st Grant Period (May 2016 to April 2017). The following documents were developed: (1) Literature Review Report on practices and technologies for waste valorization from landfills (Calvo, 2016) and (2) MINEA WG2 Workshop on technologies in the landfill-mining sector, which resulted in an overview on landfill mining projects and on state-of-the-art as well as enhanced recovery technologies (Workshop on “Technologies for material recovery from landfills and mining residues”, Book of abstracts, 2016). This report also profits from the non published report on “Science and technology in enhanced landfill mining” (EURELCO, 2016), which has been developed by the Working Group II of the European Enhanced Landfill Mining Consortium (EURELCO). Both activities examine current practices, knowledge transfer and recovery technologies across European countries, research fields and disciplines. This information is essential to assess the availability of secondary material from landfills and the viability of landfill mining projects in the context of circular economy

    Stroke service in the Netherlands: an exploratory study on effectiveness, patient satisfaction and utilisation of healthcare

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    OBJECTIVE: To assess whether shared care for stroke patients results in better patient outcome, higher patient satisfaction and different use of healthcare services. DESIGN: Prospective, comparative cohort study. SETTING: Two regions in the Netherlands with different healthcare models for stroke patients: a shared care model (stroke service) and a usual care setting. PATIENTS: Stroke patients with a survival rate of more than six months, who initially were admitted to the Stroke Service of the University Hospital Maastricht (experimental group) in the second half of 1997 and to a middle sized hospital in the western part of the Netherlands between March 1997 and March 1999 (control group). MAIN OUTCOME MEASURES: Functional health status according to the SIP-68, EuroQol, Barthel Index and Rankin Scale, patient satisfaction and use of healthcare services. RESULTS: In total 103 patients were included in this study: 58 in the experimental group and 45 in the control group. Six months after stroke, 64% of the surviving patients in the experimental group had returned home, compared to 42% in the control group (p<0.05). This difference could not be explained by differences in health status, which was comparable at that time. Patients in the shared care model scored higher on patient satisfaction, whereas patients in the usual care group received a higher volume of home care. CONCLUSIONS: The Stroke Service Maastricht resulted in a higher number of patients who returned home after stroke, but not in a better health status. Since patients in the usual care group received a higher volume of healthcare in the period of rehabilitation, the Stroke Service Maastricht might be more efficient

    Computational Design of Alloy Nanostructures for Optical Sensing of Hydrogen

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    Pd nanoalloys show great potential as hysteresis-free, reliable hydrogen sensors. Here, a multiscale modeling approach is employed to determine optimal conditions for optical hydrogen sensing using the Pd-Au-H system. Changes in hydrogen pressure translate to changes in hydrogen content and eventually the optical spectrum. At the single particle level, the shift of the plasmon peak position with hydrogen concentration (i.e., the "optical" sensitivity) is approximately constant at 180 nm/c(H) for nanodisk diameters of greater than or similar to 100 nm. For smaller particles, the optical sensitivity is negative and increases with decreasing diameter, due to the emergence of a second peak originating from coupling between a localized surface plasmon and interband transitions. In addition to tracking peak position, the onset of extinction as well as extinction at fixed wavelengths is considered. We carefully compare the simulation results with experimental data and assess the potential sources for discrepancies. Invariably, the results suggest that there is an upper bound for the optical sensitivity that cannot be overcome by engineering composition and/or geometry. While the alloy composition has a limited impact on optical sensitivity, it can strongly affect H uptake and consequently the "thermodynamic" sensitivity and the detection limit. Here, it is shown how the latter can be improved by compositional engineering and even substantially enhanced via the formation of an ordered phase that can be synthesized at higher hydrogen partial pressures

    “Medically unexplained” symptoms and symptom disorders in primary care: prognosis-based recognition and classification

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    Background: Many patients consult their GP because they experience bodily symptoms. In a substantial proportion of cases, the clinical picture does not meet the existing diagnostic criteria for diseases or disorders. This may be because symptoms are recent and evolving or because symptoms are persistent but, either by their character or the negative results of clinical investigation cannot be attributed to disease: so-called “medically unexplained symptoms” (MUS). MUS are inconsistently recognised, diagnosed and managed in primary care. The specialist classification systems for MUS pose several problems in a primary care setting. The systems generally require great certainty about presence or absence of physical disease, they tend to be mind-body dualistic, and they view symptoms from a narrow specialty determined perspective. We need a new classification of MUS in primary care; a classification that better supports clinical decision-making, creates clearer communication and provides scientific underpinning of research to ensure effective interventions. Discussion: We propose a classification of symptoms that places greater emphasis on prognostic factors. Prognosis-based classification aims to categorise the patient’s risk of ongoing symptoms, complications, increased healthcare use or disability because of the symptoms. Current evidence suggests several factors which may be used: symptom characteristics such as: number, multi-system pattern, frequency, severity. Other factors are: concurrent mental disorders, psychological features and demographic data. We discuss how these characteristics may be used to classify symptoms into three groups: self-limiting symptoms, recurrent and persistent symptoms, and symptom disorders. The middle group is especially relevant in primary care; as these patients generally have reduced quality of life but often go unrecognised and are at risk of iatrogenic harm. The presented characteristics do not contain immediately obvious cut-points, and the assessment of prognosis depends on a combination of several factors. Conclusion: Three criteria (multiple symptoms, multiple systems, multiple times) may support the classification into good, intermediate and poor prognosis when dealing with symptoms in primary care. The proposed new classification specifically targets the patient population in primary care and may provide a rational framework for decision-making in clinical practice and for epidemiologic and clinical research of symptoms

    Generic representations of abelian groups and extreme amenability

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    If GG is a Polish group and Γ\Gamma is a countable group, denote by \Hom(\Gamma, G) the space of all homomorphisms Γ→G\Gamma \to G. We study properties of the group \cl{\pi(\Gamma)} for the generic \pi \in \Hom(\Gamma, G), when Γ\Gamma is abelian and GG is one of the following three groups: the unitary group of an infinite-dimensional Hilbert space, the automorphism group of a standard probability space, and the isometry group of the Urysohn metric space. Under mild assumptions on Γ\Gamma, we prove that in the first case, there is (up to isomorphism of topological groups) a unique generic \cl{\pi(\Gamma)}; in the other two, we show that the generic \cl{\pi(\Gamma)} is extremely amenable. We also show that if Γ\Gamma is torsion-free, the centralizer of the generic π\pi is as small as possible, extending a result of King from ergodic theory.Comment: Version

    A pilot study using Tissue Velocity Ultrasound Imaging (TVI) to assess muscle activity pattern in patients with chronic trapezius myalgia

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    <p>Abstract</p> <p>Background</p> <p>Different research techniques indicate alterations in muscle tissue and in neuromuscular control of aching muscles in patients with chronic localized pain. Ultrasound can be used for analysis of muscle tissue dynamics in clinical practice.</p> <p>Aim</p> <p>This study introduces a new muscle tissue sensitive ultrasound technique in order to provide a new methodology for providing a description of local muscle changes. This method is applied to investigate trapezius muscle tissue response – especially with respect to specific regional deformation and deformation rates – during concentric shoulder elevation in patients with chronic trapezius myalgia and healthy controls before and after pain provocation.</p> <p>Methods</p> <p>Patients with trapezius myalgia and healthy controls were analyzed using an ultrasound system equipped with tissue velocity imaging (TVI). The patients performed a standardized 3-cm concentric shoulder elevation before and after pain provocation/exercise at a standardized elevation tempo (30 bpm). A standardized region of interest (ROI), an ellipsis with a size that captures the upper and lower fascia of the trapezius muscle (4 cm width) at rest, was placed in the first frame of the loop registration of the elevation. The ROI was re-anchored frame by frame following the same anatomical landmark in the basal fascia during all frames of the concentric phase. In cardiac measurement, tissue velocities are measured in the axial projection towards and against the probe where red colour represents shortening and red lengthening. In the case of measuring the trapezius muscle, tissue deformation measurements are made orthogonally, thus, indirectly. Based on the assumption of muscle volume incompressibility, blue represents tissue contraction and red relaxation. Within the ROI, two variables were calculated as a function of time: <it>deformation </it>and <it>deformation rate</it>. Hereafter, max, mean, and quadratic mean values (RMS) of each variable were calculated and compared before and after pain provocation/exercise.</p> <p>Results</p> <p>This new methodology seems valuable when looking at local muscle changes and studying the mechanism behind chronic muscle pain. The univariate analyses indicate that patients with chronic trapezius myalgia after pain provocation due to exercise at group level showed decreased strain and unchanged strain rate while healthy controls had unchanged strain and increased strain rate. However, the multivariate analysis indicates that most patients showed lower levels according to both strain and strain rate after exercise compared to most controls.</p> <p>Conclusion</p> <p>Tissue velocity imaging can help describe musculoskeletal tissue activity and dynamics in patients with chronic pain conditions. An altered muscle tissue dynamic after pain provocation/exercise among the majority of trapezius myalgia patients compared with the healthy controls was found.</p

    Changed activation, oxygenation, and pain response of chronically painful muscles to repetitive work after training interventions: a randomized controlled trial

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    The aim of this randomized controlled trial was to assess changes in myalgic trapezius activation, muscle oxygenation, and pain intensity during repetitive and stressful work tasks in response to 10 weeks of training. In total, 39 women with a clinical diagnosis of trapezius myalgia were randomly assigned to: (1) general fitness training performed as leg-bicycling (GFT); (2) specific strength training of the neck/shoulder muscles (SST) or (3) reference intervention without physical exercise. Electromyographic activity (EMG), tissue oxygenation (near infrared spectroscopy), and pain intensity were measured in trapezius during pegboard and stress tasks before and after the intervention period. During the pegboard task, GFT improved trapezius oxygenation from a relative decrease of −0.83 ± 1.48 ΌM to an increase of 0.05 ± 1.32 ΌM, and decreased pain development by 43%, but did not affect resting levels of pain. SST lowered the relative EMG amplitude by 36%, and decreased pain during resting and working conditions by 52 and 38%, respectively, without affecting trapezius oxygenation. In conclusion, GFT performed as leg-bicycling decreased pain development during repetitive work tasks, possibly due to improved oxygenation of the painful muscles. SST lowered the overall level of pain both during rest and work, possibly due to a lowered relative exposure as evidenced by a lowered relative EMG. The results demonstrate differential adaptive mechanisms of contrasting physical exercise interventions on chronic muscle pain at rest and during repetitive work tasks
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