635 research outputs found

    Chemical Recycling of Mixed Plastic Wastes by Pyrolysis - Pilot Scale Investigations

    Get PDF
    Chemical recycling of plastic wastes can be a useful complement to mechanical recycling to achieve the required plastics recycling rates and to establish a circular economy that is climate neutral and resource-efficient. Different mixed plastic wastes that are subject to future recycling efforts are studied under uniform conditions of intermediate pyrolysis characterized by a medium heating rate and pyrolysis temperature. Product distributions and selected product properties are determined, and process mass and energy balances are derived. Product yields and compositions are highly dependent on the waste pyrolyzed. The results show that pyrolysis is a suitable process to recover chemical feedstock from various complex mixed plastic wastes

    Reconstruction of nuclear charged fragment trajectories from a large gap sweeper magnet

    Full text link
    A new method to reconstruct charged fragment four-momentum vectors from measured trajectories behind an open, large gap, magnetic dispersion element (a sweeper magnet) has been developed. In addition to the position and angle behind the magnet it includes the position measurement in the dispersive direction at the target. The method improves the energy and angle resolution of the reconstruction significantly for experiments with fast rare isotopes, where the beam size at the target position is large.Comment: 13 pages, 5 figures, accepted for publication in Nucl. Instrum. Meth.

    Numerische Lösung großer strukturierter DAE-Systeme der chemischen Prozeßsimulation

    Get PDF
    Parallelizable numerical methods for solving large scale DAE systems are developed at the level of differential, nonlinear and linear equations. For this the subsystem-wise structure of the DAE systems based on unit-oriented modelling is explored. Partitionings are used to parallelize waveform relaxation and structured Newton methods. Initial values are computed with a modified Newton method. To solve large sparse systems of linear equations a special Gaussian elimination method is used. The algorithms were implemented on a CRAY C90 vector computer, as well as on both, moderately parallel CRAY J90 vector computers and massively parallel CRAY T3D machines. The methods were tested using several real life examples

    Radiative Corrections to Fixed Target Moller Scattering Including Hard Bremsstrahlung Effects

    Get PDF
    We present a calculation of the complete O(α)O(\alpha) electroweak radiative corrections to the Moller scattering process e^-e^- -> e^-e^-, including hard bremsstrahlung contributions. We study the effects of these corrections on both the total cross section and polarization asymmetry measured in low energy fixed target experiments. Numerical results are presented for the experimental cuts relevant for E-158, a fixed target e^-e^- experiment being performed at SLAC; the effect of hard bremsstrahlung is to shift the measured polarization asymmetry by approximately +4%. We briefly discuss the remaining theoretical uncertainty in the prediction for the low energy Moller scattering polarization asymmetry.Comment: 22 pgs; minor clarifications added and typos fixe

    Three-year sustained clinical efficacy of drug-coated balloon angioplasty in a real-world femoropopliteal cohort

    Get PDF
    Purpose:To report the 36-month outcomes from the prospective, multicenter, single-arm IN.PACT Global Study (ClinicalTrials.govidentifier NCT01609296) evaluating the performance of the IN.PACT Admiral drug-coated balloon (DCB) in real-world patients with femoropopliteal occlusive disease.Materials and Methods:The IN.PACT Global Study was conducted at 64 international sites and enrolled 1535 patients with complex lesions, which included bilateral disease, multiple lesions, de novo in-stent restenosis, long lesions, and chronic total occlusions. The predefined full clinical cohort included 1406 patients (mean age 68.6 years; 67.8% men) with claudication or rest pain treated with the study DCB. Mean lesion length was 12.09 +/- 9.54 cm; 18.0% had in-stent restenosis, 35.5% were totally occluded, and 68.7% were calcified. Freedom from clinically-driven target lesion revascularization (CD-TLR) was evaluated through 36 months. The safety composite endpoint was freedom from device- and procedure-related death through 30 days and freedom from major target limb amputation and clinically-driven target vessel revascularization within 36 months. All safety and revascularization events were reviewed by an independent clinical events committee.Results:The Kaplan-Meier estimate of freedom from CD-TLR through 36 months was 76.9%. The composite safety endpoint was achieved in 75.6% of patients. The 36-month all-cause mortality rate was 11.6%, and the major target limb amputation rate was 1.0%. The Kaplan-Meier estimate of freedom from CD-TLR through 36 months was significantly lower in patients with chronic limb-threatening ischemia (CLTI) compared with claudicants (67.6% vs 78.0%; p=0.003). Lesions affecting both the superficial femoral artery (SFA) and popliteal artery had lower Kaplan-Meier freedom from CD-TLR through 36 months (69.2%) than either isolated SFA (79.7%) or popliteal artery lesions (76.5%; log- rank p<0.001). Predictors of CD-TLR through 36 months included increased lesion length, reference vessel diameter <= 4.5 mm, in-stent restenosis, bilateral disease, CLTI, and hyperlipidemia.Conclusion:DCB angioplasty with the IN.PACT Admiral DCB for femoropopliteal disease in a diverse and complex real-world population is associated with sustained clinical efficacy and low rates of reinterventions at 3 years after the initial procedure

    Efficacy of a Drug-Eluting Stent Versus Bare Metal Stents for Symptomatic Femoropopliteal Peripheral Artery Disease: Primary Results of the EMINENT Randomized Trial.

    Get PDF
    BACKGROUND A clear patency benefit of a drug-eluting stent (DES) over a bare metal stent (BMS) for treating peripheral artery disease of the femoropopliteal segment has not been definitively demonstrated. The EMINENT study (Trial Comparing Eluvia Versus Bare Metal Stent in Treatment of Superficial Femoral and/or Proximal Popliteal Artery) was designed to evaluate the patency of the Eluvia DES (Boston Scientific, Marlborough, MA), a polymer-coated paclitaxel-eluting stent, compared with BMS for the treatment of femoropopliteal artery lesions. METHODS EMINENT is a prospective, randomized, controlled, multicenter European study with blinded participants and outcome assessment. Patients with symptomatic peripheral artery disease (Rutherford category 2, 3, or 4) of the native superficial femoral artery or proximal popliteal artery with stenosis ≥70%, vessel diameter of 4 to 6 mm, and total lesion length of 30 to 210 mm were randomly assigned 2:1 to treatment with DES or BMS. The primary effectiveness outcome was primary patency at 12 months, defined as independent core laboratory-assessed duplex ultrasound peak systolic velocity ratio ≤2.4 in the absence of clinically driven target lesion revascularization or surgical bypass of the target lesion. Primary sustained clinical improvement was a secondary outcome defined as a decrease in Rutherford classification of ≥1 categories compared with baseline without a repeat velocity ratio ≤2.4 in the absence of clinically driven target lesion revascularization. Health-related quality of life and walking function were assessed. RESULTS A total of 775 patients were randomly assigned to treatment with DES (n=508) or commercially available BMS (n=267). Baseline clinical, demographic, and lesion characteristics were similar between the study groups. Mean lesion length was 75.6±50.3 and 72.2±47.0 mm in the DES and BMS groups, respectively. The 12-month incidence of primary patency for DES treatment (83.2% [337 of 405]) was significantly greater than for BMS (74.3% [165 of 222]; P<0.01). Incidence of primary sustained clinical improvement was greater among patients treated with the DES than among those who received a BMS (83.0% versus 76.6%; P=0.045). The health-related quality of life dimensions of mobility and pain/discomfort improved for the majority of patients in both groups (for 66.4% and 53.6% of DES-treated and for 64.2% and 58.1% of BMS-treated patients, respectively) but did not differ significantly. At 12 months, no statistical difference was observed in all-cause mortality between patients treated with the DES or BMS (2.7% [13 of 474] versus 1.1% [3 of 263]; relative risk, 2.4 [95% CI, 0.69-8.36]; P=0.15). CONCLUSIONS By demonstrating superior 1-year primary patency, the results of the EMINENT randomized study support the benefit of using a polymer-based paclitaxel-eluting stent as a first-line stent-based intervention for patients with symptomatic peripheral artery disease attributable to femoropopliteal disease. REGISTRATION URL: https://www. CLINICALTRIALS gov; Unique identifier: NCT02921230

    Basisinformationen fĂĽr eine nachhaltige Nutzung landwirtschaftlicher Reststoffe zur Bioenergiebereitstellung

    Get PDF
    Der Ausbau von erneuerbaren Energien ist ein wesentlicher Baustein auf dem Weg zu einer nachhaltigen und sicheren Energieversorgung und zur Minderung von Treibhausgasemissionen. Auf europäischer und nationaler Ebene hat sich die Bundesregierung zur Umsetzung einer Reihe von energie- und klimapolitischen Zielen verpflichtet. Der Anteil von erneuerbaren Energien soll bis zum Jahr 2020 auf mindestens 18 Prozent und im Verkehrssektor auf mindestens 10 Prozent des Endenergieverbrauchs steigen. Bioenergie und Biokraftstoffe spielen hier eine wichtige Rolle. Um die gesellschaftliche Akzeptanz für den Ausbau von Bioenergie sicherzustellen, muss die Nutzung von Biomasse nachhaltig erfolgen. Im Bereich Bioenergie sind die europaweite zügige Umsetzung der Nachhaltigkeitsanforderungen für Biokraftstoffe und flüssige Biobrennstoffe sowie deren kontinuierliche Weiterentwicklung im Lichte neuer wissenschaftlicher Erkenntnisse wichtig. Die Nutzung von – bislang ungenutzten – Rest- und Abfallstoffen im Bereich Biokraftstoffe bietet Vorteile: eine günstigere Klimabilanz sowie die Vermeidung von Nutzungskonkurrenzen und indirekten Landnutzungsänderungen. Stroh gehört zu den Reststoffen mit dem größten bislang ungenutzten Potenzial: In Deutschland fallen im langjährigen Durchschnitt insgesamt rund 30 Millionen Tonnen Getreidestroh pro Jahr an, wenngleich die Verfügbarkeit sich in den Regionen unterscheidet und vereinzelt regionale Knappheiten auftreten können. Ein Großteil des Getreidestrohs ist noch ungenutzt und bietet eine große Chance für die energetische Nutzung. Aus diesem Grund wird die Mobilisierung dieser Ressourcen von der Bundesregierung unterstützt, unter anderem durch die doppelte Gewichtung von Biokraftstoffen, die aus Reststoffen wie Stroh produziert werden. Die nachfolgenden Beiträge sollen weitergehende Informationen über landwirtschaftliche Reststoffe (Potenzial nachhaltig verfügbarer Reststoffe, Strohnutzungskonzepte, ökonomische Aspekte) vermitteln
    • …
    corecore