Physical Sciences and Mathematics Commons^™

Gold-Catalyzed Conversion Of Lignin To Low Molecular Weight Aromatics, Yang Song, Justin K. Mobley, Ali Hussain Motagamwala, Mark Isaacs, James E. Dumesic, John Ralph, Adam F. Lee, Karen Wilson, Mark Crocker

Chemistry Faculty Publications

A heterogeneous catalyst system, employing Au nanoparticles (NPs) and Li–Al (1 : 2) layered double hydroxide (LDH) as support, showed excellent activity in aerobic oxidation of the benzylic alcohol group in β-O-4 linked lignin model dimers to the corresponding carbonyl products using molecular oxygen under atmospheric pressure. The synergistic effect between Au NPs and the basic Li–Al LDH support induces further reaction of the oxidized model compounds, facilitating facile cleavage of the β-O-4 linkage. Extension to oxidation of γ-valerolactone (GVL) extracted lignin and kraft lignin using Au/Li–Al LDH under similar conditions produced a range of aromatic monomers in high yield. …

Study On The Surface Features Of Preg-Robbing Carbonaceous Matter During Oxidation Treatment, Mana Pourdasht

Electronic Thesis and Dissertation Repository

Carbonaceous gold ores have the ability to adsorb gold (I) cyanide from leach solutions during processing. This phenomenon, known as preg-robbing, is responsible for poor recoveries as the carbonaceous materials of the ore compete with activated carbon used during the leaching and adsorption phase of processing. Chemical oxidation of carbonaceous materials by different reagents has been utilized to investigate and compare the mechanism of Au (CN)₂ adsorption onto carbonaceous materials prior to and following the treatment.

The procedure for characterization of the carbonaceous materials (plain and modified) in the sample combines the use of several analytical techniques and test …

Electrodeposited Semiconductor Nanostructures & Epitaxial Thin Films For Flexible Electronics, Naveen Kumar Mahenderkar

Doctoral Dissertations

"Single-crystal Si is the bedrock of semiconductor devices due to the high crystalline perfection which minimizes electron-hole recombination, and the dense native silicon oxide which minimizes surface states. To expand the palette of electronic materials beyond planar Si, an inexpensive source of highly ordered material is needed that can serve as an inert substrate for the epitaxial growth of grain boundary-free semiconductors, photonic materials, and superconductors. There is also a need for a simple, inexpensive, and scalable fabrication technique for the growth of semiconductor nanostructures and thin films. This dissertation focuses on the fabrication of semiconducting nanowires (polycrystalline Ge & …

Fabrication Of Size-Tunable Metallic Nanoparticles Using Plasmid Dna As A Biomolecular Reactor, Jacopo Samson, Irene Piscopo, Alex Yampolski, Patrick Nahirney, Andrea Parpas, Amit Aggarwal, Raihan Saleh, Charles Michael Drain

Publications and Research

Plasmid DNA can be used as a template to yield gold, palladium, silver, and chromium nanoparticles of different sizes based on variations in incubation time at 70 °C with gold phosphine complexes, with the acetates of silver or palladium, or chromium acetylacetonate. The employment of mild synthetic conditions, minimal procedural steps, and aqueous solvents makes this method environmentally greener and ensures general feasibility. The use of plasmids exploits the capabilities of the biotechnology industry as a source of nanoreactor materials.

Energy Pathways And Directionality In Deformation Twinning, S. Kibey, J. B. Liu, Duane D. Johnson, H. Sehitoglu

Duane D. Johnson

We present ab initiodensity functional theory calculations of twinning energy pathways for two opposite twinning modes, (111)[112¯] and (111)[1¯1¯2], in fcc materials to examine the directional nature of twinning which cannot be explained by classical twin nucleationmodels or the “twinnability” criterion. By accounting for these energy pathways in a multiscale model, we quantitatively predict the critical twinning stress for the (111)[1¯1¯2] mode to be substantially higher compared to the favorable (111)[112¯] mode (whose predicted stresses are in agreement with experiment), thus, ruling out twinning in the (111)[1¯1¯2] mode.

Preparation And Application Of Gold_Film On The Surface Of Bacterial_Modified Carbon Paste Electrode, Rongzong Hu, Yanping Ruan, Hao Xu, Jinkun Fu, Weide Zhang, Wenyun Hu

Journal of Electrochemistry

A novel method for preparation of gold_film composed of ultra_fine gold particles was reported in this paper. The gold_film was prepared by electrochemical method on the surface of the paste electrode modified with the strain Bacillus sp. D01 which has strong ability to absorb and reduce Au3+. In addition, this paper reported an experimental method of determining trace amount of Cu2+ in water solution using cathodic stripping analysis to estimate the performances of the obtained gold_film. The experimental results indicated that this new method for preparation of gold_film is simple. The obtained gold_film electrode is stable and sensitive to determining …

A Preliminary Study Of Electrochemically Amplified Measurement Of Gold Electrodeposition, Bingwei Mao, Caihui Shi, Xiaoqin Li, Lihua Xiong

Journal of Electrochemistry

Gold electrodeposition onto a glassy carbon microelectrode is studied using an electrochemical amplification method. Taking the advantage that the electrochemical reduction of K2Cr2O7 has significantly higher reaction activity on gold electrode than carbon electrede,it is tentatively used to amplify the gold electredeposition current.The results show that there is a marked increase in current of gold electrodeposition in presence of K2Cr2O7 in comparison with that absent of K2Cr2O7.The electrochemical amplification method can be applied to study the electrodeposition of very in intial stage by choosing proper systems and improving experimental conditions.

The Elkhorn Mine Of Jefferson County, Montana, David D. Walker

Bachelors Theses and Reports, 1928 - 1970

In 1901, after yielding metals valued in excess of five million dollars, it was considered worked out. Since that time the mine has passed through the hands of several own­ers, none of whom have failed to realize a profit from it. Although at no time since its zenith did it ever regain its once great production, it did provide a livelihood for those who worked it. Now with the American Smelting and Refining Company interested in it, perhaps it will once again become an important producer.

The Lilly Mine Of Powell County, Montana, Wilbur Aikin

Bachelors Theses and Reports, 1928 - 1970

For many years the Elliston District, of Powell County has been a minor producer of gold, lead, zinc, and silver. Although never among the largest producing districts of the state, it has with the exception of the war years supplied a notable tonnage of ore to the neighboring mills ever since the first placer and lode claims were located there during the late eighteen hundreds.

Benefication Of An Oxidized Lead Ore From The Franklin Mine Lewis And Clark County, Jack D. Mclenegan

Bachelors Theses and Reports, 1928 - 1970

This thesis is concerned with the beneficiation of an oxidized lead ore. Emphasis was placed upon concentration by flotation rather than by gravity methods, although some investigation was made with the Wilfley shaking table. The concentration of lead minerals received most consideration in the problem, but wherever possible attempts were made to increase the silver and gold concentration along with the lead.

A Mineral Dressing Study Of The U.S. Grant Ore, John Emmett Murphy

Bachelors Theses and Reports, 1928 - 1970

This investigation concerns the development of a satis­factory method or extracting or concentrating gold and silver from the ores of the U. S. Grant Mine. The choice between applying an extractive process and one by which the valuable mineral constituents are concentrated depends on more than one factor.

Geology Of Upper Bear Gulch And Dry Boulder Creek Area Madison County, Montana, Norman King

Bachelors Theses and Reports, 1928 - 1970

Potential gold mines lie high among the rugged peaks of the Tobacco Root Mountains of southwestern Montana. This is a region where little geologic work has been done, though extensive mine operations have been carried on, and valuable ore has been shipped.

The Geology And Ore Deposits Of The Ruby Gulch Mine, Henry J. Roletto, John X. Combo

Bachelors Theses and Reports, 1928 - 1970

The Ruby Gulch Mine, owned and operated by the Ruby Gulch Mining Company, Zortman, Montana, is one of the most important low-grade gold producers in the state. Sit­uated in the Little Rocky Mountains, the mine has had an interesting history since its discovery shortly before the turn of the century.

Testing And Concentration Of A Low Grade Gold Ore From Marysville, Montana, John B. White, Jr.

Bachelors Theses and Reports, 1928 - 1970

The purpose of this thesis was to investigate and attempt to concentrate low grade cyanided tailings rejected from the old Montana Mining and milling Company's mill situated 4 miles below the town of Marysville, Montana.

The Investigation Of Different Variables In The Assaying Of Silver Cyanide Solutions, Phillip L. Banfield

Bachelors Theses and Reports, 1928 - 1970

The cyanide method of extraction of gold and silver from their ores is extensively used in the United States and elsewhere. It is becoming increasingly more important in its use as the mining of lower grade deposits continues.

The Geology And Ore Deposits Of The Ermont Mines, James L. Kelly

Bachelors Theses and Reports, 1928 - 1970

The Ermont Mines are located sixteen miles northwest of Dillon, Montana, in section 35 of T.6S., R.11W. This is in the central part of Beaverhead County. They are considered to be in the Argenta min­ing district, the town of Argenta lying three miles to the northeast.

The Concentration Of Scheelite From The Gold Concentrates Of The Jardine Mining Company, John H. Huxley

Bachelors Theses and Reports, 1928 - 1970

The Purpose of this thesis was to investigate the possibility of concentrating scheelite from Wilfley table gold concentrates from the mill of the Jardine Mining Company; and to determine whether such concentration is economically feasible and the product of sufficiently high grade to meet commercial specifications for such a product.

The Investigation Of Different Variables In The Assaying Of Silver Cyanide Solution, Warren M. Mahan

Bachelors Theses and Reports, 1928 - 1970

The assaying of gold and silver cyanide solutions is by no means new. The first method of analysis which is given in the literature is an evaporation method by S. B. Christy in 1896. However, the fire assaying of gold and silver dates further back than this. There is a method of fire assaying for gold and silver given in literature as early as 1556 in Georgius, Agricola’s De Re Metallica book.

The Geology And Mineralogy Of The Independence Mining District, Alan Kuhlman

Bachelors Theses and Reports, 1928 - 1970

From 1888 until 1893 the district was a booming mining camp. Seven stamp mills were running and ore was be­ing mined from the Independence, King Solomon, Poorman, Golden, Hidden Treasure and Crown claims. The town of Independence, which was on the Boulder River at the fork of Basin Creek, boasted a population of 400 people.

The Quantitve Measurement Of Amalgamation, Robert A. Mcguire

Bachelors Theses and Reports, 1928 - 1970

Mercury has been known since ancient times. In fact, one mine, the "Almaden" in Spain, has been worked continuously since Roman times. It has been used during all this time for the recovery of free gold from gold concentrates, and from black sand and galena in concentrates from placer work.

Geology And Ore Deposits Of The Golden Messenger Mine, Lewis And Clark County, Helena, Montana., John C. Archibald Jr.

Bachelors Theses and Reports, 1928 - 1970

The Golden Messenger Mine which is approximately twenty-three miles northeast of Helena, Montana, near York, on Trout Creek, has long presented several problems of both theoretical and practical interest.

The Electrowinning Of Copper From Roasted Sulphides, Thomas B. Linn

Bachelors Theses and Reports, 1928 - 1970

A hydrometallurgical process for the recovery of copper from flotation concentrates has long been con­sidered an attractive possibility. The object of such a method is to produce electrolytic copper without resorting to expensive matte smelting and converting.

A Study Of The Effect Of Oxygen On The Rate Of Dissolution Of Gold In Cyanide Solutions., John A. Cook

Bachelors Theses and Reports, 1928 - 1970

The accepted chemical reactions in the dissolution of gold by cyanide solutions require the presence of gold, cyanide, water, and oxygen. The importance of dissolved oxygen in cyanide solutions as a factor is recognized by those familiar with cyanidation. Manufacturers of cyanidation equipment realize the necessity of oxygen, as shown by the appliances they have developed which are attached to the agitators in order to saturate the cyanide solutions with air.

An Investigation Of The Properties Of Some Of The White Metal Alloys, William James Walsh Jr.

Bachelors Theses and Reports, 1928 - 1970

Although there is no standardized list of alloys, most investigators have, to avoid confusion, concurred in at least grouping the metals under several general heads. Precious metals: gold, silver and the platinum group; the light metals: aluminum and magnesium; the non-ferrous metals (excluding all steels and iron-base alloys); and the antifriction metals.

Leaching Copper Minerals In The Butte District, Kenneth C. Bellows

Bachelors Theses and Reports, 1928 - 1970

The history of mining in Butte is woven about three of our principal metals. The gold placers first attracted the attention of miners in 1863, and reached their peak production in 1867. Silver was the second metal mined, and this operation required the erection of large mills with a consequent increase in mining activity that made the district a prominent producer. Although the presence of copper in the silver ore had been known, the credit for the first development of the copper veins is due Senator W. A. Clark. The original Colusa, Mining Chief, and Gambetta claims were developed to …