Portable machine welding head automatically controls arc

Portable weld tool makes weld repairs out-of-station and on the side opposite the original weld. It provides full automatic control of the arc voltage, current, wire feed, and electrode travel speed in all welding attitudes. The device is readily adaptable to commercially available straight polarity dc weld packs

Strapdown inertial measurement unit computer, volume 1 Final report

Strapdown inertial measurement unit design, calculations, and operating instruction

Studija uklanjanja srebra iz otpadaka nakita flotacijskim procesom

This article is a discussion on the proposed solution of using the flotation process to separate metals from non-metallic components present in the scrap generated while jewellery goods are being ground. For the sake of the studies analyzed, a dedicated laboratory station was established.Članak je rasprava na predloženu soluciju rabljenja flotacijskog procesa za izdvajanje metala iz nemetalnih komponenti nazočnih u otpadu koji nastaju pri izradi nakita. Glede analiza studije utemeljena je odgovarajuća laboratorijska stanica

Microstructural characteristics of new type γ-γ` Co-9Al-9W cobalt-based superalloys in as-cast state

The paper presented deals primary with the structure characteristics of a new type of cobalt-based superalloys Co-9Al-9W type, casted via induction melting process with partially dosing of Common problems described in literature are focused on difficulties in obtaining uniform distribution of tungsten, particularly in interdendritic areas. That was the reason for the modified casting process to be applied. The method of tungsten dosing into liquid melts of Co and Al allows to obtain microstructure characterized by considerably decreased microsegregation. The material obtained was analyzed by standard methods such as light and scanning microscopy with analysis of chemical composition in micro-areas. Additionally, the detailed analysis of the sub-grain level was made by S/TEM on thin foils collected from equiaxed grains zone of the ingot

Convergence and divergence in gene expression among natural populations exposed to pollution

<p>Abstract</p> <p>Background</p> <p>Natural populations of the teleost fish <it>Fundulus heteroclitus </it>tolerate a broad range of environmental conditions including temperature, salinity, hypoxia and chemical pollutants. Strikingly, populations of <it>Fundulus </it>inhabit and have adapted to highly polluted Superfund sites that are contaminated with persistent toxic chemicals. These natural populations provide a foundation to discover critical gene pathways that have evolved in a complex natural environment in response to environmental stressors.</p> <p>Results</p> <p>We used <it>Fundulus </it>cDNA arrays to compare metabolic gene expression patterns in the brains of individuals among nine populations: three independent, polluted Superfund populations and two genetically similar, reference populations for each Superfund population. We found that up to 17% of metabolic genes have evolved adaptive changes in gene expression in these Superfund populations. Among these genes, two (1.2%) show a conserved response among three polluted populations, suggesting common, independently evolved mechanisms for adaptation to environmental pollution in these natural populations.</p> <p>Conclusion</p> <p>Significant differences among individuals between polluted and reference populations, statistical analyses indicating shared adaptive changes among the Superfund populations, and lack of reduction in gene expression variation suggest that common mechanisms of adaptive resistance to anthropogenic pollutants have evolved independently in multiple <it>Fundulus </it>populations. Among three independent, Superfund populations, two genes have a common response indicating that high selective pressures may favor specific responses.</p

Effects of a reducer type on copper flash smelting slag decopperisation

In the paper, results of investigations on coke dust, anthracite dust and coal flotation concentrate application in the technology of copper flash smelting slag processing are presented. The results show that the selected reducers can be used as substitutes for the conventional coke

Mechanical properties of brass sheets

Brass is widely used in the machine industry, automotive, shipbuilding, construction, metalworking industries, as well as in the production of fittings. Certain types of brass, despite the almost identical chemical composition and the same form resulting from the standards, e.g. sheets of a certain thickness, often differ in performance, e.g. mechanical properties. The presented work compares selected mechanical properties of CuZn39Pb2 brass sheets from different manufacturers