Plasma Process Routes to Synthesis of Carbide, Boride and Nitride Ceramic Powders

1987 ◽  
Vol 98 ◽  
Author(s):  
Aaron J. Becker ◽  
Thomas N. Meyer ◽  
Frances N. Smith ◽  
Jon F. Edd
Keyword(s):  
Silicon Carbide ◽  
Titanium Diboride ◽  
Cost Effective ◽  
Future Application ◽  
Rf Plasma ◽  
Labor Costs ◽  
Plasma Process ◽  
Ceramic Powders ◽  
Conversion Efficiencies ◽  
Electronic Substrates

ABSTRACTAn iterative technique to develop plasma processing, consisting of identifying materials with unique properties, calculating conversion efficiencies, product purity and power from thermodynamic data for the chemical reactions selected to produce it and modeling the process mathematically and physically to determine capital and labor costs is illustrated with production of silicon carbide and titanium diboride in Alcoa's DC plasma facility. The work shows that submicron silicon carbide and titanium diboride containing less than 0.2% oxygen can be produced with plasmas at costs competitive with traditional processes. It has also been reported that aluminum nitride, a material which has the high thermal conductivity needed for high power electronic substrates, can be satisfactorily produced by reacting aluminum powder with nitrogen in an RF plasma system. Future application of plasmas for production of ceramics will depend on discovery of unique properties and cost effective process optimization.

Endoscopic Biopsy Pathology of Helicobacter pylori Gastritis

1999 ◽  
Vol 123 (9) ◽  
pp. 778-781 ◽  
Author(s):  
Maher Toulaymat ◽  
Sharon Marconi ◽  
Jane Garb ◽  
Christopher Otis ◽  
Shirin Nash
Keyword(s):  
Helicobacter Pylori ◽  
Specific Antibody ◽  
Cost Effective ◽  
Endoscopic Biopsy ◽  
Immunohistochemical Method ◽  
Labor Costs ◽  
Chronic Active Gastritis ◽  
Cost Effective Method ◽  
H Pylori ◽  
Helicobacter Pylori Gastritis

Abstract Objectives.—To describe the endoscopic biopsy pathology of Helicobacter pylori gastritis, compare bacterial detection by immunohistochemistry using a specific antibody with the Genta stain, and to compare the relative costs of the 2 techniques. Design.—One hundred cases of gastritis identified as positive for H pylori by Genta stain and 100 cases considered negative by the same technique were stained using an anti-H pylori–specific polyclonal antibody. Laboratory reagent and labor costs for the 2 methods were compared. Results.—Chronic active gastritis with lymphoid follicles was significantly associated with H pylori infection (P < .0001). The immunohistochemical method had a sensitivity of 97% and a specificity of 98% compared with the Genta stain, with strong agreement for grading density of organisms (κ = 0.85; P < .001). Reagent costs were similar for both methods, but immunohistochemistry using an autoimmunostainer required less dedicated technical time and hence was less expensive than the Genta stain. Conclusions.—Immunohistochemistry using a specific antibody is an accurate and cost-effective method for H pylori detection in gastric biopsies.

Internal Plasma Spray Process for Cylinder Bores in Automotive Industry

1997 ◽  
Author(s):  
G. Barbezat ◽  
S. Keller ◽  
G. Wuest
Keyword(s):  
Plasma Spray ◽  
Automotive Industry ◽  
Surface Preparation ◽  
Cost Effective ◽  
Cylinder Block ◽  
Future Application ◽  
Surface Finishing ◽  
Major Advance ◽  
Plasma Gun ◽  
Spray Process

Abstract In the Automotive Industry the need for lower manufacturing costs, the use of less strategic material, and easier, faster, and more flexible routes for manufacturing are being looked for continuously. The environmental concerns relating to the use of galvanic coatings is growing. This has led to the examination of the plasma-powder spray process for the application of coatings for surface modification. In the area of engine cylinder bore coatings a major advance is taking place in the use of a rotating plasma spray device. This paper covers the use of a plasma-powder spray process for the coating of aluminum-silicon cylinder block bores using a rotating plasma gun capable of producing coatings of reliable microstructure and integrity. Properties and microstructures of the applied coatings will be presented. Test results will be shown that the necessary bond strength of the coating can be achieved without the use of a bond coat. Surface preparation prior to coating and surface finishing methods after coating will also be discussed. Experience in Europe, Japan and the Unites States will be discussed which show that the plasma-powder spray process offers a performance proven and cost effective solution for the coating of cylinder bores, thus demonstrating the future application potential for this technology.

Silicon carbide high performance optics: a cost-effective, flexible fabrication process

2001 ◽  
Author(s):  
John M. Casstevens ◽  
Abuagela Rashed ◽  
Ronald Plummer ◽  
Don Bray ◽  
Rob L. Gates ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
High Performance ◽  
Cost Effective ◽  
Fabrication Process ◽  
Flexible Fabrication

Influence of Hydrogen Plasma Treatment on a-SiC Resistivity of the SiC/SiO2/Si Structures

2011 ◽  
Vol 276 ◽  
pp. 21-25
Author(s):  
S.O. Gordienko ◽  
A. Nazarov ◽  
A.V. Rusavsky ◽  
A.V. Vasin ◽  
N. Rymarenko ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Plasma Treatment ◽  
Structural Characteristics ◽  
Hydrogen Plasma ◽  
Rf Plasma ◽  
Current Transport ◽  
Electrical Characteristics ◽  
Variable Range Hopping ◽  
Si Substrate ◽  
Sic Film

This paper presents an analysis of the electrical characteristics of the amorphous silicon carbide films deposited on the SiO2/Si substrate. Aspects of RF plasma treatment on electrical and structural characteristics of a-SiC film are discussed. It is demonstrated that the dominant mechanism of current transport in the a-SiC thin film is determined by variable-range hopping conductivity at the Fermi level. Studies of the a-SiC film at temperatures from 300 K to 600 K also indicate that silicon carbide is a perspective material for fabrication of temperature sensor.

scholarly journals Sustainable Organic Dyes from Winemaking Lees for Photoelectrochemical Dye-Sensitized Solar Cells

2020 ◽  
Vol 10 (6) ◽  
pp. 2149
Author(s):  
Manuel Meneghetti ◽  
Aldo Talon ◽  
Elti Cattaruzza ◽  
Emilio Celotti ◽  
Elisabetta Bellantuono ◽  
...  
Keyword(s):  
Solar Cells ◽  
Organic Dyes ◽  
Low Cost ◽  
Dye Sensitized Solar Cells ◽  
Cost Effective ◽  
Simulated Solar Light ◽  
Dye Sensitized ◽  
Different Temperatures ◽  
Conversion Efficiencies ◽  
Sensitized Solar Cells

During the last two decades, Dye Sensitized Solar Cells (DSSCs) have received a great deal of attention as a promising, low-cost alternative to conventional silicon photovoltaic devices. Natural dye molecules can be used as a sensitizer for their low cost, good light absorbance, easy preparation process, and biodegradability. In this study, dyes were obtained from wine lees, the last by-product of winemaking process, supplied by a venetian winery (Italy). Polyphenols, like tannins and anthocyanins, which were extracted from winemaking lees, were adsorbed on a nanostructured ordered mesoporous titanium dioxide, previously treated at different temperatures (400–600 °C). Both dyes and titania semiconductor samples were studied with different techniques. The tests were carried out on prototypes to evaluate the cell power and the photocurrent generated under simulated solar light irradiation. The obtained solar energy conversion efficiencies are comparable to those that were reported in literature by using organic dyes extracted from vegetables, fruits, and plants. It is significant that these dyes are largely available and cost effective, since recovered from a waste otherwise to be disposed of, opening up a perspective of feasibility for inexpensive and environmentally friendly dye solar cells to generate green electricity and transforming agri-food waste into a resource.

UAS Imaging Applications to Monitor Restored Peatlands

2020 ◽  
Author(s):  
Lauri Ikkala ◽  
Hannu Marttila ◽  
Anna-Kaisa Ronkanen ◽  
Jari Ilmonen ◽  
Maarit Similä ◽  
...  
Keyword(s):  
Ghg Emissions ◽  
Cost Effective ◽  
Visual Assessment ◽  
Field Work ◽  
Unmanned Aerial Systems ◽  
Labor Costs ◽  
Natural Function ◽  
Restoration Success ◽  
Peatland Restoration ◽  
Negative Impacts

<p>Peatlands are globally threatened by the increasing exploitation. Majority of peatlands in Finland are <em>severely degraded </em>by land use and drainage activities. <strong>Peatland restoration</strong> is an effective way to increase biodiversity, return natural function of peatlands in catchment hydrology and reduce negative impacts of drainage.</p><p>Restoration activities recover the wet and open habitats crucial for many valuable species and peatlands ability to store water and nutrients. Restoration activates peat forming processes, and thus reduces greenhouse gas (GHG) emissions and returns peatlands to act as carbon sinks.</p><p><em>Restored sites are monitored</em> to determine whether the restoration has succeeded and to gather the experiences to further develop restoration methods. The traditional restoration monitoring demands intensive field work with high labor costs and special ecological expertise. Evaluation is mainly based on visual assessment at present. In addition, monitoring typically cannot cover the entire restored site.</p><p>There is strong need to develop unbiased indicators and new cost-effective methods producing <em>spatially representative high-quality information on restoration success</em>. We will study new technical possibilities for evaluation of peatland restoration success with unmanned aerial systems (UAS).</p><p>The latest image processing techniques and their use in mapping and analyzing peatland areas are to be studied. UAS provides prospects not only to ease the demanding restoration field work but also to transform the discrete nature of conventional single data points into a spatial continuum over the whole restored peatland.</p>

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