Metallurgical activities are one of the important sources of environmental pollution, especially due to inappropriate treatment of waste materials containing potentially harmful elements. Soils in the vicinity of smelting operations are the main target reservoirs for these emitted contaminants. The aim of this study was to depict reactivity of copper smelter flue dusts and slags in aqueous and soil environments using laboratory and field experiments. Slags exhibited high concentrations of As (up to 0.95 wt.%), Cu (up to 2.4 wt.%), Pb (up to 1.02 wt.%), Sb (up to 0.37 wt.%), and Zn (up to 2.45 wt.%). Copper and other metal(loid)s were predominantly bound in sulphides, especially bornite, digenite, chalcocite, and galena. Flue dusts were mainly composed of As2O3 phase (arsenolite and claudetite), with minor amounts of gypsum, galena, quartz and covellite. The main contaminants in the dust were As (53.3 wt.%), Pb (3.41 wt.%), Sb (1.26 wt.%), Zn (1.41 wt.%), Cu (1.07 wt.%) and Bi (0.80 hm.%). The leaching tests performed in the pH range of 3-12 indicated that the release of metal(loid)s from both types of metallurgical wastes was highly pH-dependent. During the leaching in deionised water, up to 42 mg/kg As was released from slags and up to 52.6 g/kg was leached from the flue dust; the latter highly...

CU-tree (Coding Unit tree) is an algorithm for adaptive QP (quantization parameter). It runs in the lookahead and decreases the QP of blocks that are heavily referenced by future blocks, taking into account the quality of the prediction and the complexity of the future blocks, approximated by the inter and intra residual. In this study, CU-tree is implemented in c65, an experimental HEVC encoder used internally by Ericsson. The effects of CU-tree are evaluated on the video clips in the HEVC Common test conditions and the performance is compared across c65, x265 and x264. The results are similar across all encoders, with average PSNR (peak signal-to-noise ratio) improvements of 3-10% depending on the fixed QP offsets that are replaced. The runtime is not impaired and improvements to visual quality are expected to be even greater. The algorithm works better at slow speed modes, low bitrates and with source material that is well suited for inter prediction. / CU-tree är en algoritm för adaptiv QP. Den körs under framåtblicken (lookahead) och minskar QP för block som refereras av många framtida block, med hänsyn tagen till prediktionens kvalitet och de framtida blockens komplexitet, approximerat av inter- och intra-skillnaden. I denna studie implementeras CU-tree i c65, en experimentell videokodare som används internt på Ericsson. Effekterna av algoritmen utvärderas på videoklippen i HEVC Common test conditions och prestandan jämförs mellan c65, x265 och x264. Resultaten är liknande i alla videokodare, med genomsnittliga PSNR-förbättringar på 3-10% beroende på vilka fasta QP-offsets som algoritmen ersätter. Körtiden påverkas inte nämnvärt och den subjektiva kvaliteten förbättras troligen ännu mer. Algoritmen fungerar bättre med långsamma hastighetsinställningar, låg bitrate samt videoinnehåll som lämpar sig väl för inter-prediktion.

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In the present work, we studied the effect of liquid Bi on the microstructure evolution of ultrafinegrained Cu at elevated temperatures.

Superoxide dismutase scavenges oxygen radicals, which have been implicated in ischemia/reperfusion (I/R) injury in the heart. Our experiments were designed to study the effect of a moderate increase of copper/zinc superoxide dismutase (CuZnSOD) on myocardial I/R injury in TgN(SOD1)3Cje transgenic mice. A species of 0.8 kb human CuZnSOD mRNA was expressed, and a 273% increase in CuZnSOD activity was detected in the hearts of transgenic mice with no changes in the activities of other antioxidant enzymes. Furthermore, immunoblot analysis revealed no changes in the levels of HSP-70 or HSP-25 levels. Immunocytochemical study indicated that there was increased labeling of CuZnSOD in the cytosolic fractions of both endothelial cells and smooth muscle cells, but not in the myocytes of the hearts from transgenic mice. When these hearts were perfused as Langendorff preparations for 45 min after 35 min of global ischemia, the functional recovery of the hearts, expressed as heart rate x LVDP, was 48 ± 3% in the transgenic hearts as compared to 30 ± 5% in the nontransgenic hearts (p < .05). The improved cardiac function was accompanied by a significant reduction in lactate dehydrogenase release from the transgenic hearts. Our results demonstrate that overexpression of CuZnSOD in coronary vascular cells renders the heart more resistant to I/R injury.

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Achieving the utmost reliability of power semiconductors is an ongoing challenge for the scientists and engineers in the packaging community of the industry and research institutions. Still the semiconductor and therefore the function of the power module could live longer, when only the bonding and joining technologies would be more stable against power and temperature cycling wearout. In particular, the conventional electrical connection to the top and bottom surface of the semiconductor is limiting the lifetime due to degradation. For both, the solder layer under the backside and the Al-wire on the topside of the die, it is necessary to develop new contact technologies, as the substitution of just one connection does not perform the required reliability of the module. In this work, different new technologies for power modules were evaluated and an own development is presented. Especially the new development is characterized by an outstanding reliability while keeping the design flexibility of the currently applied methods. To achieve that, the solder joints were replaced by Ag-sintered connections and Cu-wires were bonded as a substitute of Al-wires. This new approach is called DBB-Technology („Danfoss BondBuffer“) and is demonstrated in the example of a 1700V DBB power module. With the help of this technology sintering creates two joints: One between the bottom of die and the substrate and between the die and a thin Cu-foil, which is located on top. This Cu foil (BondBuffer) enables the Cu-bond process as top contact technology without damaging the semiconductor. The DBB Cu foil acts as an absorber for the high bond-forces. The detailed characterization of a DBB-covered semiconductor module reveals an extraordinary high reliability improvement, enhanced thermal impedance and upgraded electrical properties. / Leistungsmodule unterliegen in der Anwendung vielfältigen, kombinierten Beanspruchungen, die je nach Anwendung eine Herausforderung an unterschiedliche Verbindungsstellen im Modul darstellen. Die Betriebsdauer eines Leistungsmoduls wird im Wesentlichen von den halbleiternahen Aufbau- und Verbindungstechniken limitiert. Das geht z.B. aus umfangreichen Lastwechseluntersuchungen hervor, in denen als Fehlermechanismen die Zerrüttung des Lots unter dem Chip oder das Abheben des Aluminium-Bonddrahts vom Halbleiter identifiziert wurden. Die einzelnen Verbindungsschichten im Leistungsmodul bilden eine Funktionskette, die beim Ausfall nur eines Gliedes die gesamte Funktionalität verliert. Maßnahmen zur Optimierung einzelner Schichten, z. B. der Halbleiter-Substrat-Verbindung oder nur der oberseitigen Chipkontaktierung, bringen alleinstehend also nicht den gewünschten Erfolg. In dieser Arbeit werden unterschiedliche Aufbaukonzepte leistungselektronischer Module aus Fachveröffentlichungen verglichen, bevor das eigene Konzept beschrieben wird. Die Lösung basiert dabei auf innovativen und sehr robusten Fügetechnologien, die gezielt herkömmliche Verbindungen im Aufbau ersetzen. Das Ergebnis ist ein Leistungsmodul mit verbesserten thermischen, elektrischen und thermo-mechanischen Eigenschaften. Eine wesentliche Rolle spielt dabei das Silbersintern als Alternative zum Löten. Dank der Sintertechnik geht der Halbleiter eine hochfeste Verbindung mit dem Substrat ein. Darüber hinaus ermöglicht die Sintertechnologie das stoffschlüssige Verbinden einer dünnen Kupferfolie mit der oberen Halbleitermetallisierung. Diese Kupferfolie ist erforderlich, um das Cu-Drahtbonden für die oberseitige Kontaktierung der Halbleiter anzuwenden, ohne diesen aufgrund hoher Bondkräfte zu zerstören. Dank der vorteilhaften Materialeigenschaften ist die Cu-Bondverbindung deutlich leistungsfähiger als eine Al-Bondverbindung. Diese Kombination aus robusten Fügestellen trägt den Namen DBB-Technologie („Danfoss BondBuffer“) und soll zukünftig dank der Verfügbarkeit sinterbarer Halbleiter in hochzuverlässigen Leistungsmodulen angewendet werden.

Gold-based catalysts can be replaced with platinum group catalysts in catalytic automotive exhaust aftertreatment if their thermal stability and durability issues can be resolved. Hence, one of the potential markets for gold catalysis is the automotive after treatment market, our interest is to synthesize a gold-based catalyst which has practical applications in automotive industry specifically for diesel-methane dual fuel low-temperature combustion strategy where the exhaust temperature is varying from ~ 200 to400° C. Our research focused on synthesizing a bimetallic gold-copper catalyst which is not only highly active for CO oxidation reaction but also sinter-resistant at temperatures normally observed at LTC engine exhaust. The Au-Cu@SiO2 catalyst exhibited excellent efficacy for CO oxidation with >95% conversion to CO2 achieved at 300 °C. While the presence of Cu enhanced CO conversion at low to intermediate temperatures (50-300 °C), silica encapsulation of the Au-Cu nanocomposites facilitated for remarkable stability of the catalyst. Moreover, the catalyst exhibited remarkable stability at high reaction temperatures which could be attributed to the SiO2 encapsulation of nanoparticles. The activity and stability of Au-Cu@SiO2 catalyst are suitable for its application in automotive after treatment devices, especially in low-temperature combustion engine exhaust.