2,673,103 research outputs found

    Non-Cyanide Silver as a Substitute for Cyanide Processes

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    Since the mid 1800s, silver has been deposited from a cyanide-based formulation on a commercial basis. Commercial non-cyanide silver plating solutions were first made generally available in the late 1970s, and yet today the vast majority, and nearly all commercial silver plating is conducted in formulations that contain cyanide. This study was conducted to determine if non-cyanide silver plating processes that have been developed in the last few years would be suitable replacements for cyanide based formulations.published or submitted for publicatio

    Effect of Barrel Design on Dragout Rate

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    New barrels for electroplating have been developed and manufacturers of some of these newer designs have claimed significant improvements in drag-out losses by their new barrels. Since water consumption and waste generation are directly tied to dragout rate from processing solutions, it is clear that there is a need to produce a method of evaluating such barrels, so that the user minimizes pollution. This study, funded by The Illinois Waste Management Research Center (WMRC) produced a benchmark test to compare drag-out rates of plating barrels. The study used this test to compare two size ranges of plating barrels, small and large. For small barrels (6??? x 12???), testing showed that a reduction in dragout rate, as high as 48%, may be achieved. For large barrels (16??? x 36???), testing showed that a reduction as high as 44% may be obtained. A survey was conducted to determine the relative durability of the barrels under study. The survey indicated that some of the barrels that produce lower levels of dragout (those using fine mesh) may unfortunately provide less service life, but other low dragout rate barrels offered service life that is similar to traditional barrels.published or submitted for publicatio

    Lawrence Metal Products, Inc. invoice

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    An invoice from Lawrence Metal Products, Inc. of Lynbrook, New York for library equipment.https://scholars.fhsu.edu/library_bldg/1049/thumbnail.jp

    Metal-on-metal total hip arthroplasty: does increasing modularity affect clinical outcome?

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    BACKGROUND: Modularity of metal-on-metal (MoM) implants has come under scrutiny due to concerns regarding additional sources of metal debris. This study is a retrieval analysis of implants from the same manufacturer with the same MoM bearing surface. The difference between the implants was presence or absence of modular junctions. METHODS: This is a retrospective study of 31 retrieved implants from 31 patients who received a Conserve Wright Medical MoM hip prosthesis. The 31 implants consisted of 16 resurfacings and 15 implants with modular junctions; 4 conventional THAs and 11 modular-neck THAs. RESULTS: 43% of pre-revision MRI scans performed on resurfacing implants and 91% performed on the modular implants illustrated evidence of an adverse local tissue reaction. There was no difference in pre-revision blood metal ion levels or bearing surface wear between the resurfacings and modular implants. The neck-head tapers of the modular group showed low levels of material loss. However, the neck-stem tapers showed increased severity of corrosion and material loss. CONCLUSIONS: The modular implants had an increased incidence of adverse local tissue reaction. This could be related to the presence of modular junctions, particular the neck-stem junction which showed increased susceptibly to corrosion

    Production of metal nanoparticles by agro-industrial wastes. A green opportunity for nanotechnology

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    The feasibility of producing silver nanoparticles (Ag NPs) using phenolic extracts from agro-industrial wastes as reducing agents was investigated. Phenolic extracts were obtained from bilberry wastes (BW) and spent coffee grounds (SCG) with aqueous ethanol as extraction solvent. Experiments were carried out in batch at 25 °C by adding appropriate amounts of phenolic extracts to a silver nitrate aqueous solution. The formation of Ag NPs was monitored spectrophotometrically by measuring the intensity of the surface plasmon resonance (SPR) band of silver at 415-435 nm. Depending on the process conditions, the synthesis of Ag NPs was completed in 3 to 5 hours. Characterization of the resulting reaction products by XRD, SEM and DLS showed that nanoparticles were formed with a spherical shape and an average size of 10-20 nm. Overall, the results obtained suggest that BW and SCG could be used as a source of reducing agents for the production of metal NPs and that agro-industrial wastes may represent a valid alternative to the use of microorganisms, whole plants or plant parts for the biogenic synthesis of NPs

    Metal-metal reinforced laminar composites

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    Two prototype laminar composites have shown potential for high strength and high temperature applications. These composites might be made with less in-place anisotropy and be less expensive than comparable fiber composites

    Methods For Growing A Non-phase Separated Group-iii Nitride Semiconductor Alloy

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    Systems and methods for MBE growing of group-III Nitride alloys, comprising establishing an average reaction temperature range from about 250 C to about 850 C; introducing a nitrogen flux at a nitrogen flow rate; introducing a first metal flux at a first metal flow rate; and periodically stopping and restarting the first metal flux according to a first flow duty cycle. According to another embodiment, the system comprises a nitrogen source that provides nitrogen at a nitrogen flow rate, and, a first metal source comprising a first metal effusion cell that provides a first metal at a first metal flow rate, and a first metal shutter that periodically opens and closes according to a first flow duty cycle to abate and recommence the flow of the first metal from the first metal source. Produced alloys include AlN, InN, GaN, InGaN, and AlInGaN.Georgia Tech Research Corporatio

    Method for fabricating solar cells having integrated collector grids

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    A heterojunction or Schottky barrier photovoltaic device comprising a conductive base metal layer compatible with and coating predominately the exposed surface of the p-type substrate of the device such that a back surface field region is formed at the interface between the device and the base metal layer, a transparent, conductive mixed metal oxide layer in integral contact with the n-type layer of the heterojunction or Schottky barrier device having a metal alloy grid network of the same metal elements of the oxide constituents of the mixed metal oxide layer embedded in the mixed metal oxide layer, an insulating layer which prevents electrical contact between the conductive metal base layer and the transparent, conductive metal oxide layer, and a metal contact means covering the insulating layer and in intimate contact with the metal grid network embedded in the transparent, conductive oxide layer for conducting electrons generated by the photovoltaic process from the device
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