Need of Gallium Recovery from Waste Samples: A Review

2021 ◽  
Vol 34 (1) ◽  
pp. 09-18
Author(s):  
Monika Swami ◽  
Kinjal Patel
Keyword(s):  
Coal Fly Ash ◽  
Supply And Demand ◽  
Rare Metal ◽  
Substrate Material ◽  
Sources Of Information ◽  
Flue Dust ◽  
Extraction Processes ◽  
Trace Concentrations ◽  
Reliable Methods ◽  
Suitable Environment

Gallium is an vital rare metal mainly because of its growing demand in different domain of life. It has wide applications. Gallium is considered as the backbone of the electronics industry. The supply and demand of gallium-bearing products has gradually increased during the past decade. Therefore, from the environmental stand point the need for sensitive and reliable methods for determining trace concentrations of gallium has become apparent in various fields. Gallium has become increasingly popular as a substrate material for electronic devices. Aside from ore, gallium can be obtained from such industrial sources as the Bayer process caustic liquor that is a byproduct of bauxite processing, flue dust removed from the fume-collection system in plants that produce aluminum by the electrolytic process, zinc refinery residues, gallium scrap materials, and coal fly ash. The purification process for gallium can start with solvent-extraction processes where the concentrations of impurities, especially metals, are reduced to the ppm range. The main aim of this paper is to simply put up the salient facts regarding gallium and identify applicable sources of information thereby one may create a suitable environment for the development of methods for the production of gallium via leaching through various waste samples.

The Outlook for World Meat Supply and Demand

1998 ◽  
Vol 27 (1) ◽  
pp. 19-22
Author(s):  
Loek Boonekamp
Keyword(s):  
Agricultural Policy ◽  
Supply And Demand ◽  
Policy Research ◽  
Economic Research ◽  
Sources Of Information ◽  
Medium Term ◽  
Production And Consumption ◽  
The Us ◽  
Food And Agricultural Policy ◽  
Broad Outline

This paper presents a medium-term outlook for world meat supply and demand. Following a broad outline of likely developments in production and consumption of all meats, the focus engages on the outlook for world beef markets over the five-year period from 1997. The projections presented in this paper are based largely on those published by the OECD. So far as non-OECD countries are concerned, the main sources of information have been the Economic Research Service of the US Department for Agriculture and the Food and Agricultural Policy Research Institute of the Universities of Iowa State and Missouri, Columbia.

scholarly journals Supply and Demand Strategy of Rare Metal in Korea - Focusing on the Stocking pile -

2014 ◽  
Vol 21 (4) ◽  
pp. 313-317
Author(s):  
Taek-Soo Kim ◽  
Bum-Sung Kim ◽  
Min-Ha Lee ◽  
Kyoung-Tae Park
Keyword(s):  
Supply And Demand ◽  
Rare Metal

scholarly journals Regional Acreage Response by Quarter for Fresh Tomatoes: An Example of the Use of Mixed Estimation

1979 ◽  
Vol 11 (2) ◽  
pp. 69-74 ◽  
Author(s):  
Michael D. Hammig
Keyword(s):  
Statistical Estimation ◽  
Supply And Demand ◽  
Market Equilibrium ◽  
Data Series ◽  
Response Model ◽  
Sources Of Information ◽  
Equilibrium Solutions ◽  
Additional Information ◽  
Salad Vegetables ◽  
Mixed Estimation

The study reported was motivated by a USDA study to develop complete quarterly models of supply and demand for a selected set of fresh salad vegetables. The acreage planted component enters recursively into both the acreage harvested and yield relations used in many of these models. Consequently, predictions of acreage planted are instrumental in predicting total supply and resulting market equilibrium solutions.In modeling acreage planted over relevant seasons within four regions, various sources of information can be brought to bear. Obviously, data series on past plantings, costs, and prices provide the foundation of statistical estimation of an acreage response model. However, additional information from previous studies, economic theory, and subjective judgment on the part of the researcher also can be incorporated into the model through the use of the mixed estimation technique developed by Theil and Goldberger [8].

A sequential integration approach using Aspergillus Niger to intensify coal fly ash as a rare metal pool

Fuel ◽  
2020 ◽  
Vol 270 ◽  
pp. 117460
Author(s):  
HaiFeng Su ◽  
Hua Chen ◽  
JiaFu Lin
Keyword(s):  
Fly Ash ◽  
Aspergillus Niger ◽  
Coal Fly Ash ◽  
Rare Metal ◽  
Metal Pool ◽  
Integration Approach

scholarly journals The initial evaluation of performance of hard anti-wear coatings deposited on metallic substrates: thickness, mechanical properties and adhesion measurements – a brief review

2019 ◽  
Vol 58 (1) ◽  
pp. 50-65 ◽  
Author(s):  
Magdalena Łępicka ◽  
Małgorzata Grądzka-Dahlke
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Substrate Material ◽  
Wear Performance ◽  
Metallic Substrates ◽  
Evaluation Of Performance ◽  
Wear Coatings ◽  
Material Information ◽  
Reliable Methods

Abstract The demand for metallic materials of exceptional tribological performance is rapidly growing due to constant development of automotive, tool or implant industry. As great attention nowadays is being paid to the surfacemodified materials, there is a need of establishing reliable methods for evaluation of coated metallic alloys. In this paper, methods for thickness, adhesion and mechanical properties measurement of anti-wear coatings are considered. The importance of altering the mechanical properties of the coating with regards to its expected wear performance is also discussed. According to the numerous findings, it is reasonable to pay attention to the hardness and Young’s modulus of the developed coating, as well as on the mismatch between its Young’s modulus and the elastic modulus of the substrate material. Information provided in this paper has been thoroughly illustrated and enriched with our own experience in the field.

scholarly journals Reflections on the Political Economy of European Wine Appellations

2021 ◽  
Author(s):  
Julian M. Alston ◽  
Davide Gaeta
Keyword(s):  
Policy Design ◽  
Supply And Demand ◽  
Market Mechanism ◽  
Economic Consequences ◽  
Sources Of Information ◽  
Market Prices ◽  
Alternative Sources ◽  
Signaling Quality ◽  
European Agriculture ◽  
Lemons Problem

AbstractToday’s European wine policy is centered on a system of appellations, implemented as geographical indications (GIs), that entail significant technological regulations—restricting the varieties that may be grown, while imposing maximum yields per hectare and other rules regarding grape production and winemaking practice. This paper outlines the historical development of European wine policy under the CAP, and presents a more detailed analysis of the economic consequences of the rules and regulations under the appellation system. The introduction of these rules and regulations was probably beneficial initially, both for their didactive effect on wine producers and consumers and as a way of overcoming a significant “lemons” problem in the market. However, those same rules and regulations are much less valuable today, given (1) the potential for alternative sources of information to solve the lemons problem, and (2) evidence that the appellation system per se might not be effectively serving that purpose as well as it once did, while some of the regulations impose significant social costs. Yield restrictions, in particular, are economically inefficient as a way of enhancing and signaling quality (their ostensible purpose) and as a way of restricting total supply to support market prices and thus producer incomes (a significant motivation). The inherent weaknesses of the policy design are compounded by failures of governance. A less heavy-handed approach to policy would allow more scope for the market mechanism to match supply and demand for this signature product from European agriculture.

Lithography below 100 nm

1983 ◽  
Vol 41 ◽  
pp. 96-99
Author(s):  
L. D. Jackel
Keyword(s):  
Spatial Distribution ◽  
Electron Beam ◽  
Electron Scattering ◽  
Electron Beam Lithography ◽  
Substrate Material ◽  
Local Electron ◽  
Electron Dose ◽  
Positive Resist ◽  
Exposure Process

Most production electron beam lithography systems can pattern minimum features a few tenths of a micron across. Linewidth in these systems is usually limited by the quality of the exposing beam and by electron scattering in the resist and substrate. By using a smaller spot along with exposure techniques that minimize scattering and its effects, laboratory e-beam lithography systems can now make features hundredths of a micron wide on standard substrate material. This talk will outline sane of these high- resolution e-beam lithography techniques.We first consider parameters of the exposure process that limit resolution in organic resists. For concreteness suppose that we have a “positive” resist in which exposing electrons break bonds in the resist molecules thus increasing the exposed resist's solubility in a developer. Ihe attainable resolution is obviously limited by the overall width of the exposing beam, but the spatial distribution of the beam intensity, the beam “profile” , also contributes to the resolution. Depending on the local electron dose, more or less resist bonds are broken resulting in slower or faster dissolution in the developer.

Defects in β-SiC thin films grown on α-SiC substrates

1988 ◽  
Vol 46 ◽  
pp. 568-569
Author(s):  
Karren L. More
Keyword(s):  
Thin Films ◽  
Semiconductor Device ◽  
Lattice Mismatch ◽  
Chemical Vapor ◽  
Substrate Material ◽  
Growth Interface ◽  
Si Substrates ◽  
Thermal Expansion Coefficients ◽  
Device Applications ◽  
Expansion Coefficients

Beta-SiC is an ideal candidate material for use in semiconductor device applications. Currently, monocrystalline β-SiC thin films are epitaxially grown on {100} Si substrates by chemical vapor deposition (CVD). These films, however, contain a high density of defects such as stacking faults, microtwins, and antiphase boundaries (APBs) as a result of the 20% lattice mismatch across the growth interface and an 8% difference in thermal expansion coefficients between Si and SiC. An ideal substrate material for the growth of β-SiC is α-SiC. Unfortunately, high purity, bulk α-SiC single crystals are very difficult to grow. The major source of SiC suitable for use as a substrate material is the random growth of {0001} 6H α-SiC crystals in an Acheson furnace used to make SiC grit for abrasive applications. To prepare clean, atomically smooth surfaces, the substrates are oxidized at 1473 K in flowing 02 for 1.5 h which removes ∽50 nm of the as-grown surface. The natural {0001} surface can terminate as either a Si (0001) layer or as a C (0001) layer.

Distortion in lattice-resolution scanned-probe microscope images

1993 ◽  
Vol 51 ◽  
pp. 522-523
Author(s):  
L. Fei
Keyword(s):  
Film Studies ◽  
Lattice Structure ◽  
Substrate Material ◽  
Repulsive Force ◽  
Instrument Calibration ◽  
Microscope Images ◽  
Probe Microscope ◽  
Electron Microscopes ◽  
Diffraction Patterns ◽  
Lattice Resolution

Scanned probe microscopes (SPM) have been widely used for studying the structure of a variety material surfaces and thin films. Interpretation of SPM images, however, remains a debatable subject at best. Unlike electron microscopes (EMs) where diffraction patterns and images regularly provide data on lattice spacings and angles within 1-2% and ∽1° accuracy, our experience indicates that lattice distances and angles in raw SPM images can be off by as much as 10% and ∽6°, respectively. Because SPM images can be affected by processes like the coupling between fast and slow scan direction, hysteresis of piezoelectric scanner, thermal drift, anisotropic tip and sample interaction, etc., the causes for such a large discrepancy maybe complex even though manufacturers suggest that the correction can be done through only instrument calibration.We show here that scanning repulsive force microscope (SFM or AFM) images of freshly cleaved mica, a substrate material used for thin film studies as well as for SFM instrument calibration, are distorted compared with the lattice structure expected for mica.

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