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Silver City, Stagecoach
No full textSilver City stagecoach leaving August 1882 0730 for Deming, N. M.Person identified as G. W. Huffaker, Wells Fargo agent, standing on wheel; Miss Wilson, sister of “Billy” Wilson, manager of Morrill & Co.; Mrs. Harry Booth; Miss Jessie Foote; Harry Booth (all passengers off for the “States)” and the Committee of Farewell are Edgar L. Swaine, mining engineer; Gordon Bradley, banker.8 bit; 300 ppi; ScanMaker 9800X
Plasma controlled surface texturing of silver foils
No full textSeveral industrial processes involve the use of silver in one form or another, two of which there are in the use of conductive adhesives within the Personnel Computer Boards manufacturing industry and as a catalyst for the epoxidation of ethylene. Both these processes could be improved significantly if the silver surface were altered morphologically. One possible way to improve either of the aforementioned technologies would be to plasma modify the silvers surface. The aim of the work described in this thesis is to produce a high surface area silver using a high frequency rf plasma, with the hope that with further research this technology may be used to modify silver powder for use in conductive adhesives or as a catalyst for the epoxidation of ethylene This thesis describes the use of high frequency continuous wave (CW) oxygen plasmas for the treatment of silver foils, in particular the effects on surface morphology of changes in rf power (15-50 W), gas pressure (0.2-0.8 mbar), exposure time (lmin-2hrs), orientation of the foil in the reactor with respect to the gas flow (perpendicular or parallel) and distance of the foil from the live electrode (0-17cm). Scanning Electron Microscopy was used to observe these morphological changes. Further to observing the surface topographies of the oxides under these various conditions, a brief, but no means complete, study of the structure of the various oxides produced at these various conditions was performed using X-ray powder diffraction. Reduction of these oxidised foils using a hydrogen plasma (CW) was investigated, with particular emphasis being placed on how rf power (15-50W), gas pressure (0.2-0.8 torr) and exposure times (lmin-2hrs) affected the extent of reduction of the oxidised foil (using X-ray Crystallograhy) and its surface morphology (using Scanning Electron Microscopy ).Pulsed oxygen plasma treatments of the silver foils and CW oxygen plasma treatment of earthed silver samples were performed to try and elucidate the mechanism behind any surface modification. From the above investigations it was found that oxygen plasma treatment of silver foils resulted in significant modification of the surfaces, and this depended on the energy density of the plasma. The optimum surface texture (in terms of apparent surface area) was observed at rf powers of 15W, gas pressures of 0.8 torr, exposure times of 30 min, and at distances of 8-9 cm from the live electrode. The oxidised foil could be fully reduced back to silver metal using a hydrogen plasma, with little change in the optimum surface morphology. The pulsing and earthing studies indicated that the formation of the new surface textures was either due to surface diffusion of a charged silver species or was caused by ion bombardment of the silver surface resulting in a facetted surface texture. The oxides observed were Ag0 and Ag(_2)0, but to what extent each was present appeared to depend on the energy density of the plasma
Boulton and Fothergill silver.
No full textPhDThis thesis is about the silver business of Matthew Boulton and John
Fothergill at their Soho Manufactory near Birmingham. Their
partnership lasted from 1762 until 1782.
A rounded discussion of the topic is attempted. Within the contexts
of industry elsewhere and Soho's other activities, successive chapters
cover the early development, marketing, production, design, and later
decline of the partners' silver.
Silver plate was prestigious and, untypically for Boulton, he
concentrated on sales to the public rather than trade customers. To
attract orders he made modest charges. This was viable where mainly
machinery was used to make plate, even though sales were not high,
since the expense of machinery was substantially covered by the larger
sales of non-silver items. However, where Boulton relied to a
greater degree upon hand methods, he lacked technical means to
compensate for low profit-margins. Moreover, inefficiency and the
firm's lack of capital which led to substantial bankers' interest
charges on payment for bullion, particularly when customers paid late,
caused losses. These problems applied particularly to silver plate
and were mainly responsible for the decision to reduce production
drastically; however, the manufacture of a large range of small items
remained relatively consistent.
The thesis includes appendices. Some contain new information about
annual totals for the following aspects of the business: the volume of
assay silver; each type of article; pieces sold on commission; and
sterling silver supplies. Other appendices provide details about the
partners' silversmiths and extracts from a Soho inventory.
This thesis involves a more detailed use of sources than previous
studies of the topic. Apart from the silver itself (which is
selectively illustrated), the Matthew Boulton Papers and statistics
derived from The Birmingham Assay office provide the main sources.
Manuscripts covering silver production elsewhere provide contextual
material for understanding the partners' silver business
Production of silver-loaded zeolites and investigation of their antimicrobial activity
No full textA thesis submitted in partial fulfilment of the requirements of the University of Wolverhampton for the degree of Doctor of PhilosophyThe production of silver-loaded zeolites either by ion exchange method or by isomorphous substitution of silver ions into zeolites frameworks and their antimicrobial activity is presented. Silver-loaded zeolites produced by ion-exchange in this work include silver-exchanged zeolite X, silver-exchanged zeolite A and silver-exchanged high-alumina Phillipsite. Silver-doped Analcime was produced by isomorphous substitution of silver ions into the Analcime framework. The silver-loaded zeolites were characterized by X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), energy dispersive X-ray (EDX) analysis, particle size analysis and Fourier transformed infrared (FTIR) spectroscopy. Studies showed that the amount of silver ions loaded into the zeolites frameworks differed for each zeolite. XRD analysis showed little or no changes in the phase purity of all zeolites before and after ion exchange or before and after substitution of silver ions. SEM analysis and particle size analysis showed that the morphology of each zeolite particles was closely related before and after ion exchanged or before and after substitution of silver ions. The antimicrobial activity of these silver-loaded zeolites was investigated by exposing Escherichia coli K12W-T, Staphylococcus aureus NCIMB6571 and Pseudomonas aeruginosa NCIMB8295 suspended in tryptone soya broth (TSB) to the silver-loaded zeolites. The first stage of the investigation involved the exposure of the strains to silver-loaded zeolites in TSB for a duration of 24 hours at different concentration of silver-loaded zeolites. The second stage involved the exposure of the strains to silver-loaded zeolites in TSB over a period of two hours. The persistency of antimicrobial activity of silver-loaded zeolites was investigated by retrieving each silver-loaded zeolite from the first exposure cultures, washed copiously with de-ionised water and adding to fresh bacterial suspensions. To understand the mode of antimicrobial activity of the silver-loaded zeolites, the uptake of silver ions by the strains, composition of fatty acid, as well as the DNA content of Escherichia coli K12W-T was studied. The results obtained showed silver ions appeared to elute from the zeolites frameworks into the TSB in anomalous trend. All three microorganisms were completely inhibited within one hour with the silver-loaded zeolites retaining their antimicrobial activity. The release of silver ions from the zeolites frameworks followed first-order kinetics with varying rate constants and half-lives. The fatty acid composition of all strains as well as the DNA content of Escherichia coli K12W-T were affected by the action of silver ions
Effect of silver content on the structure and antibacterial activity of silver-doped phosphate-based glasses
No full textStaphylococcus aureus can cause a range of diseases, such as osteomyelitis, as well as colonize implanted medical devices. In most instances the organism forms biofilms that not only are resistant to the body's defense mechanisms but also display decreased susceptibilities to antibiotics. In the present study, we have examined the effect of increasing silver contents in phosphate-based glasses to prevent the formation of S. aureus biofilms. Silver was found to be an effective bactericidal agent against S. aureus biofilms, and the rate of silver ion release (0.42 to 1.22 µg·mm–2·h–1) from phosphate-based glass was found to account for the variation in its bactericidal effect. Analysis of biofilms by confocal microscopy indicated that they consisted of an upper layer of viable bacteria together with a layer (20 µm) of nonviable cells on the glass surface. Our results showed that regardless of the silver contents in these glasses (10, 15, or 20 mol%) the silver exists in its +1 oxidation state, which is known to be a highly effective bactericidal agent compared to that of silver in other oxidation states (+2 or +3). Analysis of the glasses by 31P nuclear magnetic resonance imaging and high-energy X-ray diffraction showed that it is the structural rearrangement of the phosphate network that is responsible for the variation in silver ion release and the associated bactericidal effectiveness. Thus, an understanding of the glass structure is important in interpreting the in vitro data and also has important clinical implications for the potential use of the phosphate-based glasses in orthopedic applications to deliver silver ions to combat S. aureus biofilm infections
Silver City, Main Street Stores
No full textOn the SW corner of Main Street and Broadway are the New Cash Store (owned and operated by Mr. & Mrs. H. D. Gilbert); the Grant County Bank (Newton Bradley, manager); and G. W. Bailey Drug Store, in which is also the post office.Persons identified (L-R): H. D. Gilbert; Mrs. H.D. Gilbert; Miss Mary Sullivan; Mrs. Lottie (Deno) Thurmond; Jake House; Gurdon Bradley; one of the two men sitting on the wall is thought to be train robber Mike O'Brien and the other is unknown; Dr. G. W. Bailey; Judge W. H. Newcomb; Tom Cobb; surveyor ____ Ross; others unidentified (one man may be Al Card). The bank failed December 1883. The Gilberts moved their store to the I. N. Cohen building in February 1884. The post office first located here in May 1873.8 bit; 348 ppi; ScanMaker 9800X
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Inactivation of the antibacterial and cytotoxic properties of silver ions by biologically relevant compounds
No full textThere has been a recent surge in the use of silver as an antimicrobial agent in a wide range of domestic and clinical products, intended to prevent or treat bacterial infections and reduce bacterial colonization of surfaces. It has been reported that the antibacterial and cytotoxic properties of silver are affected by the assay conditions, particularly the type of growth media used in vitro. The toxicity of Ag+ to bacterial cells is comparable to that of human cells. We demonstrate that biologically relevant compounds such as glutathione, cysteine and human blood components significantly reduce the toxicity of silver ions to clinically relevant pathogenic bacteria and primary human dermal fibroblasts (skin cells). Bacteria are able to grow normally in the presence of silver nitrate at >20-fold the minimum inhibitory concentration (MIC) if Ag+ and thiols are added in a 1:1 ratio because the reaction of Ag+ with extracellular thiols prevents silver ions from interacting with cells. Extracellular thiols and human serum also significantly reduce the antimicrobial activity of silver wound dressings Aquacel-Ag (Convatec) and Acticoat (Smith & Nephew) to Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli in vitro. These results have important implications for the deployment of silver as an antimicrobial agent in environments exposed to biological tissue or secretions. Significant amounts of money and effort have been directed at the development of silver-coated medical devices (e.g. dressings, catheters, implants). We believe our findings are essential for the effective design and testing of antimicrobial silver coatings
Synthesis of silver nano particles and fabrication of aqueous Ag inks for inkjet printing
No full textThe main problem in preparing stable and printable inks containing nanoparticles
for inkjetprinting is to overcome the strong agglomeration of the particles in
dispersion medium. In thisstudy, the silver particles with diameter around 50 nm
were produced by a simple wet chemistrymethod. Stable aqueous printable inks
were formulated by using the combination of a triblockcopolymer and high
intensity focused ultrasound (HIFU). Various factors that affect the
inkstability, such as, copolymer content and time of HIFU treatment, were
investigated. The inkcontaining 5 wt% silver has a viscosity of about 2 mPas and
surface tension 30 mN/m at 25◦C,which meet inkjet printer requirements. Such
inks have been successfully printed on Al2O3ceramics and low-temperature co-
fired ceramics (LTCC) and the printed films show lowresistivi
Nanoscale silver: Thin-film structure and antimicrobial functionality
No full textSince antiquity, silver has been used as a material to reduce spoilage. Over the past decades, there has been an increasing scientific and commercial interest in developing silver surfaces due to the increasing number of drug resistant microorganisms. In this study, the effect of nanostructuring silver films as an antimicrobial against the bacteria Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) was examined. Films consisting of 3 nm chromium adhesion layers and nominal 20 nm silver surfaces (assuming flat deposition) were deposited by thermal evaporation and nanostructuring was controlled by varying the incident angle of the silver onto the substrate. Four substrate angles were used including 0 °, 18 °, 40 ° and 70 ° to the horizontal. Examination by atomic force microscope, Rutherford backscattering and ellipsometry showed that as the incident angle of deposition increased, so did the nanostructuring and surface roughness. This was coupled with a decrease in film thickness. Incubation of the nanostructured thin-films in bacterial broths with E. coli and S. aureus showed that as the surface roughness increased the antimicrobial activity was enhanced – both in solution and for bacteria adhered to the thin-films. Inductively coupled plasma mass spectrometry was used to measure silver leaching from the thin-films and showed a negligible loss for all films, with corresponding low-levels of antimicrobial activity. Further indicating the enhancing effect of nanostructuring as an antimicrobial. All thin-films showed biological fouling after prolonged exposure to the bacterial solutions, which reduced antimicrobial activity. Cleaning the films with IPA showed that the films could be regenerated but with some loss of antimicrobial activity. The mechanism of thin-film antimicrobial activity is at this time unknown but it is speculated that nanostructuring is capable of penetrating the cell envelopes of bacteria, which enhances the antimicrobial activity of silver
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