10 research outputs found

    Forms of Occurrence of Selected Metals in Metallurgical Slags in Comparison with their Geochemical Properties

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    Badania składu chemicznego żużli hutniczych pochodzących zarówno z bieżącej produkcji, jak i składowanych przez wiele lat na zwałowiskach wykazały, że są one bardzo zróżnicowane. Żużle zawierają znaczne ilości metali, w tym metali ciężkich, obok pierwiastków z grupy niemetali i lantanowców. W artykule na podstawie badań mineralogiczno-chemicznych żużli stalowniczych oraz żużli po produkcji stali i rud Zn-Pb, scharakteryzowano formy występowania i powiązania ze składnikami fazowymi wybranych metali: żelaza, manganu, cynku, ołowiu i in. Stwierdzono, że metale w żużlach hutniczych mogą występować w postaci drobnych kropli nie oddzielonych od żużla w procesie hutniczym, tworzyć skupienia polimetaliczne, własne fazy (zwłaszcza tlenkowe) oraz ukrywać się w strukturach faz krzemianowych. Znaczna ilość metali jest rozproszona w szkliwie i substancji amorficznej. Prowadzone badania dostarczają informacji na temat występowania metali w żużlach hutniczych, co jest szczególnie istotne podczas wykonywania prac związanych z gospodarczym wykorzystaniem żużli. Dotyczy to zwłaszcza coraz częściej podejmowanych prób pozyskiwania pierwiastków z żużli hutniczych. Działania te determinują konieczność analizy składu chemicznego i fazowego żużli, gdyż mogą stanowić ważną wskazówkę np. przy opracowywaniu odpowiedniej technologii odzysku pierwiastków.Research of metallurgical slags chemical composition, originating both from current production as well as gathered in dumping grounds formany years, show that they are very diversified. Slags contain substantial amounts of metals, including heavy metals, apart from elements from groups of non-metals and lanthanoids. In the article occurrence forms and relations with phase components of selected metals (iron, manganese, zinc, lead and others) on the basis of mineralogical and chemical research on slags after steel and ore Zn-Pb production were characterized. It was stated that metals may occur in metallurgical slags as fine drops not separated from slag during a metallurgical process, may form polymetallic aggregates, their own phases (especially oxide ones) and hide in structures of silicate phases. A considerable amount of metals is dissipated in glaze and amorphous substance. The conducted research delivers information on the occurrence of metals in metallurgical slags, which is extremely important during work connected with economic exploitation of slags. It especially refers to increasing attempts of acquiring elements from metallurgical slags. These activities determine the necessity of analyzing chemical and phase composition of slags because they may be an important indication, for instance while working on a proper technology of elements recovery

    Ultrasound of the coracoacromial ligament in asymptomatic volunteers and patients with shoulder impingement

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    BACKGROUND: The coracoacromial ligament is part of the coracoacromial arch, which is considered to be involved in shoulder impingement. PURPOSE: To compare the coracoacromial ligament on ultrasound in asymptomatic volunteers and in patients with subacromial shoulder impingement. MATERIAL AND METHODS: Twenty-nine asymptomatic volunteers (mean age, 35.5 years) and 29 patients (mean age, 49.9 years) with shoulder impingement, diagnosed by experienced shoulder surgeons, were prospectively included. Two radiologists obtained and analyzed ultrasound images of the coracoacromial ligament in the longitudinal axis. RESULTS: The ligament thickness was 1.4 ± 0.2 mm at its midportion, 1.8 ± 0.4 mm at the coracoid, and 2.1 ± 0.6 mm at the acromion in asymptomatic volunteers compared with 1.3 ± 0.2 mm, 1.9 ± 0.5 mm, and 1.9 ± 0.5 mm in impingement patients for observer 1. The ligament length was 30.6 ± 2.4 mm in asymptomatic volunteers compared with 30.4 ± 3.6 mm in impingement patients for observer 1. An anteriorly convex shape of the superficial contour of the coracoacromial ligament was significantly more frequent in impingement patients compared with asymptomatic volunteers for both observers (observer 1: 10% (3/29) versus 45% (13/29), P value <0.01; observer 2: 10% (3/29) versus 38% (11/29), P value <0.03). The comparison of the remaining parameters of the coracoacromial ligament, such as the thickness, length, echogenicity, and fibrillation did not reveal significant differences between volunteers and patients. CONCLUSION: While thickness or length of the coracoacromial ligament were similar in volunteers and patients with shoulder impingement, an anteriorly convex shape of the superficial contour of the coracoacromial ligament was significantly more frequent in impingement patients compared with asymptomatic volunteers

    A Trust Evaluation Method Based on Logic and Probability Theory

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    The DANish randomized, double-blind, placebo controlled trial in patients with chronic HEART failure (DANHEART): A 2 × 2 factorial trial of hydralazine-isosorbide dinitrate in patients with chronic heart failure (H-HeFT) and metformin in patients with chronic heart failure and diabetes or prediabetes (Met-HeFT)

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    Objectives: The DANHEART trial is a multicenter, randomized (1:1), parallel-group, double-blind, placebo-controlled study in chronic heart failure patients with reduced ejection fraction (HFrEF). This investigator driven study will include 1500 HFrEF patients and test in a 2 × 2 factorial design: 1) if hydralazine-isosorbide dinitrate reduces the incidence of death and hospitalization with worsening heart failure vs. placebo (H-HeFT) and 2) if metformin reduces the incidence of death, worsening heart failure, acute myocardial infarction, and stroke vs. placebo in patients with diabetes or prediabetes (Met-HeFT). Methods: Symptomatic, optimally treated HFrEF patients with LVEF ≤40% are randomized to active vs. placebo treatment. Patients can be randomized in either both H-HeFT and Met-HeFT or to only one of these study arms. In this event-driven study, it is anticipated that 1300 patients should be included in H-HeFT and 1100 in Met-HeFT and followed for an average of 4 years. Results: As of May 2020, 296 patients have been randomized at 20 centers in Denmark. Conclusion: The H-HeFT and Met-HeFT studies will yield new knowledge about the potential benefit and safety of 2 commonly prescribed drugs with limited randomized data in patients with HFrEF
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