Precipitation of Gold, Silver, and Copper from Cyanide Solutions on Activated Charcoal.

Charcoal has been known for a considerable length of time to have the property of recovering gold, silver, and copper from cyanide solutions of these metals. Quantita­tive data that may shed light on the mechanism of the re­moval of these metals is very limited except that char­coal in a form known as activated has the power to abstract gold and silver in considerable quantities from the above solutions.

Report of Investigation on the Physical Characteristics of the Oil Sands from the Cut Bank Field, Montana

The purpose of this research was to study the physical characteristics, mainly, porosity and permeability of the oil sands from the Cut Bank field, Glacier County, Montana. In so doing, a better understanding of the relation­ship of these physical characteristics to one another and to the pool itself could be obtained.

Porosity and Oil Absorption Properties of Metal Compacts of Copper - Tin - Graphite

Powder metallurgy, the most recent innovation in met­allurgical process, is not a new art; although not until recently did it become a matter of general interest, this being due not only to the products formed but also to the possibilities of future developments. The manufacture and application of metal powders is now beginning to take a position as a recognized part of the science of metallurgy.

A Preliminary Study of the Separation of the Copper Sulfides from Sphalerite and the Effect of Certain Reagents on Some of the Pure Copper Minerals in Synthetic Mixtures

The problem of separating the copper sulfide minerals from sphalerite, in copper - zinc ores, has been a difficult one. This is largely due to the lack of adequate research and the small amount of data obtainable on the behavior of copper and zinc sulfide minerals in flotation circuits.

The Effect of Manganese and Magnesium on the Hardening of Copper-Aluminum Alloys

During recent years, duralumin and all aluminum alloys have been made the object of much discussion regarding their hardening mechanism. The commercial success of nearly all of the alloys of aluminum and mag­nesium is dependent on their ability to age or precipitation harden.

Structural model of the CopA copper ATPase of Enterococcus hirae based on chemical cross-linking

The CopA copper ATPase of Enterococcus hirae belongs to the family of heavy metal pumping CPx-type ATPases and shares 43% sequence similarity with the human Menkes and Wilson copper ATPases. Due to a lack of suitable protein crystals, only partial three-dimensional structures have so far been obtained for this family of ion pumps. We present a structural model of CopA derived by combining topological information obtained by intramolecular cross-linking with molecular modeling. Purified CopA was cross-linked with different bivalent reagents, followed by tryptic digestion and identification of cross-linked peptides by mass spectrometry. The structural proximity of tryptic fragments provided information about the structural arrangement of the hydrophilic protein domains, which was integrated into a three-dimensional model of CopA. Comparative modeling of CopA was guided by the sequence similarity to the calcium ATPase of the sarcoplasmic reticulum, Serca1, for which detailed structures are available. In addition, known partial structures of CPx-ATPase homologous to CopA were used as modeling templates. A docking approach was used to predict the orientation of the heavy metal binding domain of CopA relative to the core structure, which was verified by distance constraints derived from cross-links. The overall structural model of CopA resembles the Serca1 structure, but reveals distinctive features of CPx-type ATPases. A prominent feature is the positioning of the heavy metal binding domain. It features an orientation of the Cu binding ligands which is appropriate for the interaction with Cu-loaded metallochaperones in solution. Moreover, a novel model of the architecture of the intramembranous Cu binding sites could be derived.

The Effects of High-Oil Corn or Typical Corn with or without Supplemental Fat on Diet Digestibility in Finishing Steers

Two 3 x 3 latin squares were utilized in an 84-day digestion trial with ruminally- and duodenallycannulated steers. Diets consisted of 73 to 78% whole corn grain, 12.3% corn silage and 2.0% N, with treatment differences being high-oil corn- (HOC), isogenetic typical-corn- (TC), or isogenetic typical-corn + fat- (TC+F) based diets. The HOC and TC+F diets were formulated to provide the same ether extract (EE) content. All diets were fed at 90% of ad libitum intake. Chromic oxide was used as a digestibility marker. Total tract dry matter (DM) (P=.08), organic matter (OM) (P=.08) and nitrogen (N) (P=.06) digestibilities tended to be greater for TC than HOC diets, whereas starch neutral detergent fiber (NDF), acid detergent fiber (ADF), and ether extract digestibilities were similar (P>.10). There were no differences (P>.10) in total tract dry matter, organic matter, starch, NDF, ADF, ether extract, or nitrogen digestibilities between TC+F and HOC diets or TC and TC+F diets. Ruminal digestion of dry matter, organic matter, starch, NDF, ADF, and feed nitrogen was similar (P>.10) among treatments. Microbial-nitrogen flow and efficiencies were also similar (P>.10) among treatments. Results indicate finishing steer diets composed of primarily HOC are equally or less digestible than similar diets composed of TC, and adding fat to TC diets did not affect the digestibility of the diet when fed to finishing steers.

A Note on US Royalty Relief, Rent Sharing and Offshore Oil Production

This paper offers an economic analysis explaining why royalty relief under US Federal legislation is expensive in terms of revenue foregone, but is largely ineffective in increasing US offshore oil production. Repeal of royalty relief is therefore justified.

Geochemistry on Yangla copper deposit, China

The Yangla copper deposit, situated in the middle section of Jinshajiang tectonic belt between Zhongza-Zhongdian block and Changdu-Simao block, is a representative and giant copper deposit that has been discovered in Jinshajiang-Lancangjiang-Nujiang region in recent years. There are coupled relationship between Yangla granodiorite and copper mineralization in the Yangla copper deposit. Five molybdenite samples yielded a well-constrained 187Re-187Os isochron age of 233.3±3 Ma, the metallogenesis is therefore slightly younger than the crystallization age of the granodiorite. S, Pb isotopic compositions of the Yangla copper deposit indicate that the ore-forming materials were derived from the mixture of upper crust and mantle, also with the magmatic contributions. In the late Early Permian, the Jinshajiang Oceanic plate was subducted to the west, resulting in the formation of a series of gently dipping thrust faults in the Jinshajiang tectonic belt, meanwhile, accompanied magmatic activities. In the early Late Triassic, which was a time of transition from collision-related compression to extension in the Jinshajiang tectonic belt, the thrust faults were tensional; it would have been a favorable environment for forming ore fluids. The ascending magma provided a channel for the ore-forming fluid from the mantle wedge. After the magma arrived at the base of the early-stage Yangla granodiorite, the platy granodiorite at the base of the body would have shielded the late-stage magma from the fluid. The magma would have cooled slowly, and some of the ore-forming fluid in the magma would have entered the gently dipping thrust faults near the Yangla granodiorite, resulting in mineralization.

Political limits on the world oil trade : firm-level evidence from US firms

International politics affect trade patterns, especially for firms in extractive industries. We construct the firm-level dataset for the U.S. oil-importing companies over 1986-2010 to test whether the state of international relations with the trading partners of the U.S. affect importing behavior of the U.S. firms. To measure "political distance" between the U.S. and her trading partners we use voting records for the UN General Assembly. We find that the U.S. firms, in fact, import significantly less oil from the political opponents of the U.S. Our conjecture is that the decrease in oil imports is mainly driven by large, vertically-integrated U.S. firms that engage in foreign direct investment (FDI) overseas.

The effects of international politics on oil-exporting developing countries

International politics affects oil trade. But does it affect the oil-exporting developing countries more? We construct a firm-level dataset for all U.S. oil-importing companies over 1986-2008 to examine how these firms respond to changes in "political distance" between the U.S. and her trading partners, measured by divergence in their UN General Assembly voting patterns. Consistent with previous macro evidence, we first show that individual firms diversify their oil imports politically, even after controlling for unobserved firm heterogeneity. We conjecture that the political pattern of oil imports from these individual firms is driven by hold-up risks, because oil trade is often associated with backward vertical FDI. To the extent that developing countries have higher hold-up risks because of their weaker institutions, the political effect on oil trade should be more significant in the developing world. We find that oil import decisions are indeed more elastic when firms import from developing countries, although the reverse is true in the short run. Our results suggest that international politics can affect oil revenue and hence long-term development in the developing world.