metal exchange
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2022 ◽  
Vol 5 (4) ◽  
pp. 159-174
Author(s):  
N. S. Kostrykina ◽  
A. V. Korytin ◽  
E. V. Melkova

The subject. This article discusses the taxation of copper and nickel extraction in Australia, Canada, Chile, Kazakhstan and USAThe purpose of the article is to confirm or disprove the hypothesis that the experience of taxation of copper and nickel extraction in Australia, Canada, Chile, Kazakhstan and USA may be used for modifying the mineral extraction tax (MET) in Russia in order to increase the share of resource rent collected by the government.The methodology of research includes legal interpretation and economic analysis of the tax legislation in United States, Canada, Australia, Chile and Kazakhstan as countries with a well-developed tax system and a significant size of the mining sector in overall GDP.The authors select the legislative acts of these countries and regions that determine the procedure for collecting taxes in the extraction of metal ores, including those containing copper and nickel, as well as in the production of copper and nickel. The selected legislative acts are analyzed to determine the essential parameters of taxation. Particular attention is paid to the method of calculating the tax base, taking into account the approach to assessing the value of the taxable object, permissible tax deductions and exceptions, which allows authors to test the hypothesis put forward by determining which part of the value of a mineral resource is withdrawn during taxation.The main results, scope of application. Mineral extraction tax is the main tool for collecting natural resource rent in Russia. However, the level of taxation of solid minerals and coal is disproportionately low compared to their share in the production and export of raw materials. Thus, in 2018, the amount of MET on all minerals totaled 100.5 billion rubles, while the MET collected from oil and natural gas amounted to 5,979.6 billion rubles, i.e. 60 times as much. At the same time, the role of solid minerals in the Russian economy is comparable to the role of oil and gas. The share of the main types of minerals in the exports of the Russian Federation in 2018 was 20.4% compared to 56% for oil and gas, i.e. the difference of less than three times. The contribution of the industries related to the extraction of minerals and production of metals (mining of coal, ores, diamonds, metallurgy, fertilizer production) to the Russian GDP is about half as much as that of industries involved in the extraction and processing of oil and natural gas (7% and 14% of GDP respectively).In view of the above, it is important to develop a new approach to the taxation of solid minerals in Russia based on the world’s best practices. In order to identify the general principles of their taxation, we have conducted a detailed analysis of the tax legislation in a number of countries with a well-developed tax system and a significant size of the mining sector (the United States, Canada, Australia, Chile and Kazakhstan). We focused on the taxation of copper and nickel ores mining.Conclusions. The analysis of the international experience of taxation of copper and nickel mining sector reveals the following trend: the tax is calculated based on the market value of the extracted minerals, which is linked to the price quotes for the relevant product on an organized metal exchange (for example, the price of pure metal on the London Metal Exchange). This approach can be used in the Russian tax practice in several ways. First, Russia can adopt the Australian model where royalty on a mineral resource can be levied at the time of sale of the useful component irrespective of the processing stage (ore, concentrate or metal). The second potential model is based on the actual sale price of the product (provided it is sold in an arm’s length transaction) after deducting the costs of processing (i.e., smelting, enrichment etc., depending on the stage of processing) to arrive at the market value of the ore at the "mine mouth". The third is the Canadian model which is similar to the second one, but with the extraction costs also deducted from the sale price.


2021 ◽  
Vol 8 (4) ◽  
pp. 435-443
Author(s):  
Marcela Lascsáková

The focus of this paper aims at comparison of two prognostic numerical models with different strategies for accuracy improvement. To verify prediction performance of proposed models, the forecasts of aluminium stock exchanges on the London Metal Exchange were carried out as numerical solution of the Cauchy initial problem for the first-order ordinary differential equation. Two techniques for accuracy improvement were utilized, replacing the initial condition value by the nearest known stock exchange and a modification of the differential equation in solved Cauchy initial problem by means of two known initial values. We dealt with an idea of how different price development affected the accuracy of proposed strategies. With regard to obtained results, it was found that the prognoses obtained by using two known initial values were more increasing or decreasing than prognoses calculated by utilizing the initial condition drift. The strategy of a changing form of the differential equation in the Cauchy initial problem can be considered slightly more accurate. Faster increased prognoses were more advantageous especially at a steep price increase and within a price increase following the price decline. A moderate increase of the prognoses determined by the initial condition drift fit reasonably well a price fluctuation and a price decline following the price increase.


2021 ◽  
Author(s):  
laura samperisi ◽  
xiaodong zou ◽  
zhehao huang ◽  
akif tezcan ◽  
jie zhu ◽  
...  

We report the synthesis and characterization of a new series of permanently porous, three-dimensional metal-organic frameworks (MOFs), M-HAF-2 (M= Fe, Ga or In), constructed from tetratopic, hydroxamate-based, chelating linkers. The structure of M-HAF-2 was determined by three-dimensional electron diffraction (3DED), revealing a unique interpenetrated hcb-a net topology. This unusual topology is enabled by the presence of free hydroxamate groups, which lead to the formation of a diverse network of cooperative interactions comprising single metal-hydroxamate nodes, staggered π–π interactions between linkers and H-bonding interactions between metal-coordinated and free hydroxamate groups. Such extensive, multimodal interconnectivity is reminiscent of the complex noncovalent interaction networks of proteins and endows M-HAF-2 frameworks with good thermal and exceptionally high chemical stability and allows them to readily undergo post-synthetic metal exchange (PSE). We demonstrate that M-HAF-2 can serve as versatile porous materials for ionic separations, likely aided by one-dimensional channels lined by continuously π-stacked aromatic groups and H-bonding hydroxamate functionalities. As a new addition to the small group of hydroxamate-based MOFs, M-HAF-2 represents a structural merger between MOFs and hydrogen-bonded organic frameworks (HOFs).


2021 ◽  
Vol 11 (24) ◽  
pp. 11687
Author(s):  
Abdul Malik P. Peedikakkal ◽  
Isam H. Aljundi

In metal-organic frameworks (MOFs), mixed-metal clusters have the opportunity to adsorb hydrogen molecules due to a greater charge density of the metal. Such interactions may subsequently enhance the gravimetric uptake of hydrogen. However, only a few papers have explored the ability of mixed-metal MOFs to increase hydrogen uptake. The present work reveals the preparation of mixed metal metal-organic frameworks M-MOF-5 (where M = Ni2+, Co2+, and Fe2+) (where MOF-5 designates MOFs such as Zn2+ and 1,4-benzenedicarboxylic acid ligand) using the post-synthetic exchange (PSE) technique. Powder X-ray diffraction patterns and scanning electron microscopy images indicate the presence of crystalline phases after metal exchange, and the inductively coupled plasma–mass spectroscopy analysis confirmed the exchange of metals by means of the PSE technique. The nitrogen adsorption isotherms established the production of microporous M-MOF-5. Although the additional metal ions decreased the surface area, the exchanged materials displayed unique features in the gravimetric uptake of hydrogen. The parent MOF-5 and the metal exchanged materials (Ni-MOF-5, Co-MOF-5, and Fe-MOF-5) demonstrated hydrogen capacities of 1.46, 1.53, 1.53, and 0.99 wt.%, respectively. The metal-exchanged Ni-MOF-5 and Co-MOF-5 revealed slightly higher H2 uptake in comparison with MOF-5; however, the Fe-MOF-5 showed a decrease in uptake due to partial discrete complex formation (discrete complexes with one or more metal ions) with less crystalline nature. The Sips model was found to be excellent in describing the H2 adsorption isotherms with a correlation coefficient ≅ 1. The unique hydrogen uptakes of Ni− and Co-MOF-5 shown in this study pave the way for further improvement in hydrogen uptake.


ACS Omega ◽  
2021 ◽  
Author(s):  
Lehlohonolo E. Mphuthi ◽  
Elizabeth Erasmus ◽  
Ernst H. G. Langner

2021 ◽  
Author(s):  
Jose David Rosales ◽  
William Quintero ◽  
Jhon Cruz ◽  
Balbino Perdomo ◽  
Militza Quintero ◽  
...  

The SARS-CoV-2 coronavirus causes severe acute respiratory syndrome and has caused a global pandemic by causing the COVID-19 disease. To monitor and control it, diagnostic methods such as molecular and serological tests are necessary. The serological approach use SARS-CoV-2 antigens to detect the antibodies present in patients using quantitative techniques such as enzyme-linked immunosorbent assay (ELISA) or qualitative rapid tests such as lateral flow chromatography (RDT's). The main antigens used are the spike protein (S) and the nucleocapsid protein (N). Both proteins are obtained in different expression systems, in eukaryotic cells, their production is expensive, so in this work we chose a simpler and cheaper system such as prokaryotic to express and purify the N protein. Thereore, the nucleotide sequence had to being optimized to be expressed in Escherichia coli. The protein N is sensitive to E.coli proteases and also has the ability to self-proteolyze under native conditions, degrading into different fragments. However, under denaturing conditions, using urea and at pH 5.3 it is stable and efficiently purified using metal exchange chromatography (IMAC). In our purification strategy, we surprisingly found that by not using a sonicator, a homogeneous and time-stable preparation of the recombinant antigen is obtained. An approximate yield of 200 mg / L was obtained. It was then tested with healthy sera and sera from COVID-19 convalescent patients in Wester-blot tests that were able to recognize it. Our work provides a novel strategy to produce the SARS-CoV-2 protein N so that it can be used as an input in the development and innovation of serological tests in the diagnosis of COVID-19.


2021 ◽  
Vol 68 (2) ◽  
pp. 38-52
Author(s):  
Dominik Krężołek

In this paper, we present a modification of the Weibull distribution for the Value-at- Risk (VaR) estimation of investment portfolios on the precious metals market. The reason for using the Weibull distribution is the similarity of its shape to that of empirical distributions of metals returns. These distributions are unimodal, leptokurtic and have heavy tails. A portfolio analysis is carried out based on daily log-returns of four precious metals quoted on the London Metal Exchange: gold, silver, platinum and palladium. The estimates of VaR calculated using GARCH-type models with non-classical error distributions are compared with the empirical estimates. The preliminary analysis proves that using conditional models based on the modified Weibull distribution to forecast values of VaR is fully justified.


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