542 research outputs found

    Production of magnesium from Great Salt Lake, Utah USA

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    Magnesium metal has been commercially produced from the waters of Great Salt Lake since 1972. Worldwide use of magnesium has markedly increased over the last twenty years due to its unique properties of low density and high strength. Great Salt Lake is a valuable resource for the recovery of magnesium minerals due to its chemical composition, natural geography/climate and proximity to transportation and markets. US Magnesium LLC and its predecessors have overcome various technical challenges as well as political hurdles, climatic calamities and market uncertainties. This discussion will describe the extensive use of solar evaporation ponds to produce suitable raw materials for magnesium manufacture as well as significant mineral by-products. It will also include a basic technical description of the magnesium metal manufacturing process, an explanation of the operating history of the Rowley Utah plant, and briefly touch on the current commercial uses of magnesium metal

    The Negotiation Checklist: How To Win The Battle Before It Begins

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    Being well-prepared going into a negotiation is key to being successful when you come out. This negotiation checklist is a tool that can maximize your preparation effectiveness and efficiency

    When Employees Retaliate Against Self-Serving Leaders: The Influence of the Ethical Climate

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    © 2019, Springer Nature B.V. Leaders have been shown to sometimes act self-servingly. Yet, leaders do not act in isolation and the perceptions of the ethical climate in which leaders operate is expected to contribute to employees taking counteractive measures against their leader (that is, employees’ desire for retaliation, and supervisor-directed deviance). We contend that in an ethical climate employees feel better equipped to stand up and take retaliation measures. Moreover, we argue that this is explained by employees’ feelings of trust. In two studies using different methods (an experimental study and a multi-source study), we predict and find evidence that the relationship between self-serving leader behavior and employees’ desire for retaliation and supervisor-directed deviance is stronger when the ethical climate is high rather than low. Moreover, we show that trust in the leader mediates these relationships

    Discovery Of Cold, Pristine Gas Possibly Accreting Onto An Overdensity Of Star-Forming Galaxies At Redshift z ~ 1.6

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    We report the discovery of large amounts of cold (T ~ 10^4 K), chemically young gas in an overdensity of galaxies at redshift z ~ 1.6 in the Great Observatories Origins Deep Survey southern field (GOODS-S). The gas is identified thanks to the ultra-strong Mg II absorption features it imprints in the rest-frame UV spectra of galaxies in the background of the overdensity. There is no evidence that the optically-thick gas is part of any massive galaxy (i.e. M_star > 4x10^9 M_sun), but rather is associated with the overdensity; less massive and fainter galaxies (25.5 < z_850 < 27.5 mag) have too large an impact parameter to be causing ultra-strong absorption systems, based on our knowledge of such systems. The lack of corresponding Fe II absorption features, not detected even in co-added spectra, suggests that the gas is chemically more pristine than the ISM and outflows of star-forming galaxies at similar redshift, including those in the overdensity itself, and comparable to the most metal-poor stars in the Milky Way halo. A crude estimate of the projected covering factor of the high-column density gas (N_H >~ 10^20 cm-2) based on the observed fraction of galaxies with ultra-strong absorbers is C_F ~ 0.04. A broad, continuum absorption profile extending to the red of the interstellar Mg II absorption line by <~ 2000 km/s is possibly detected in two independent co-added spectra of galaxies of the overdensity, consistent with a large-scale infall motion of the gas onto the overdensity and its galaxies. Overall, these findings provides the first tentative evidence of accretion of cold, chemically young gas onto galaxies at high redshift, possibly feeding their star formation activity. The fact that the galaxies are members of a large structure, as opposed to field galaxies, might play a significant role in our ability to detect the accreting gas.Comment: 57 pages, 17 figures, 1 table; accepted for publication by ApJ (Aug 9, 2011); minor modifications to match the accepted versio

    The relationship between mineralization and tectonics at the Kainantu gold-copper deposit, Papua New Guinea

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    Epithermal veins and breccias at the Kainantu gold–copper deposit in Papua New Guinea, host gold mineralization in NW–SE steeply dipping lodes. The lodes are parallel to a pre-mineralization dextral strike-slip shear-zone network, which is itself parallel in places to an early greenschist-facies cleavage in basement schists. The cleavage, shear zone and veins are all cut by dextral strike-slip faults. High Au grades correlate with areas of obliquity between the shear-zone fabrics and the cleavage, and plunge at approximately 40° SE in the plane of the lodes – coincident with minor fold axes related to a crenulation cleavage in the basement rocks. This clear structural history shows that gold mineralization was confined to a particular late structural event, but lode geometry was influenced by all previous structures, as well as being displaced by post-mineralization faulting. The north–south shortening recorded through most of the tectonic history can be related to Tertiary convergence along the major plate boundary located approximately 15 km north of the mine. However, mineralization occurred under a different tectonic regime from the current north–south convergence, when there was a change of tectonics between 9 and 6 Ma, possibly related to delamination

    Effective public involvement in the HoST-D Programme for dementia home care support: From proposal and design to methods of data collection (innovative practice)

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    Public involvement is an important element in health and social care research. However, it is little evaluated in research. This paper discusses the utility and impact of public involvement of carers and people with dementia in a five-year programme on effective home support in dementia, from proposal and design to methods of data collection, and provides a useful guide for future research on how to effectively involve the public. The Home SupporT in Dementia (HoST-D) Programme comprises two elements of public involvement, a small reference group and a virtual lay advisory group. Involving carers and people with dementia is based on the six key values of involvement – respect, support, transparency, responsiveness, fairness of opportunity, and accountability. Carers and people with dementia gave opinions on study information, methods of data collection, an economic model, case vignettes, and a memory aid booklet, which were all taken into account. Public involvement has provided benefits to the programme whilst being considerate of the time constraints and geographical locations of members

    Radiocarbon chronology and environmental context of Last Glacial Maximum human occupation in Switzerland

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    Central Europe during the Last Glacial Maximum (LGM) was dominated by polar desert and steppe-tundra biomes. Despite this, a human presence during this time period is evident at several locations across the region, including in Switzerland, less than 50 km from the Alpine ice sheet margin. It has been hypothesised that such human activity may have been restricted to brief periods of climatic warming within the LGM, but chronological information from many of these sites are currently too poorly resolved to corroborate this. Here we present a revised chronology of LGM human occupation in Switzerland. AMS radiocarbon dating of cut-marked reindeer (Rangifer tarandus) bones from the sites of Kastelhöhle-Nord and Y-Höhle indicates human occupation of Switzerland was most likely restricted to between 23,400 and 22,800 cal. BP. This timeframe corresponds to Greenland Interstadial 2, a brief warming phase, supporting the hypothesis that human presence was facilitated by favourable climatic episodes. Carbon, nitrogen and sulphur stable isotope analysis of the fauna provides palaeoenvironmental information for this time period. These findings contribute to our understanding of human activity in ice-marginal environments and have implications for understanding cultural connections across central Europe during the LGM
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