Articoli di riviste sul tema "Metals of economic interest"
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1
Cerecedo, E., V. Rodríguez, P. D. Andrade, E. Salinas, J. Hernández e A. Arenas. "Chemical Characterization of a Mineral Deposit of Economic Interest". MRS Proceedings 1766 (2015): 115–22. http://dx.doi.org/10.1557/opl.2015.418.
Abstract (sommario):
ABSTRACTChemical and structural characterization of four representative samples of an ore deposit located in the eastern of Hidalgo State was carried out. According with the results, it could be appreciate some areas showing silicified zones with abundant amounts of disseminated pyrites that are part of a rock unit from early Jurassic consisting in inter - bedded black shales and sandstones. Thus, the contents of base metal were greater than 30 ppm Zn and 9 ppm Cu. Chemical analysis of rock gave the following results; 82 ppm of Ba, 1.64 % Wt. Fe, 0.08 % Wt. Ti, 40.8 % Wt. Si, 20 ppm of Ce, 2.2 ppm Co, 30 ppm Cr, 2.7 ppm Cs, 0.9 ppm Er, 2.5 ppm Ga, 1.6 ppm Gd , 1.5 ppm Ge, 9 ppm La, 71 ppm Li, 104 ppm Mn, 10 ppm Nd , 17 ppm Rb, 2 ppm Se, 9 ppm Sr, 10 ppm Ta, 6 ppm Te, 28 ppm V, 9 ppm Y, and 0.7 ppm Yb, among others. Finally, the values found for precious metals, were; Au < 0.02 ppm, Pd <0.05 ppm, Pt <0.05 ppm. It was inferred that the low content of base metals in outcrop studied, are due to the alteration of the black shales. According to these results, we can consider a stratiform – type mineralization of Pb-Zn which could be prospective for SEDEX – Type deposit. By means of XRD, it was possible to identify; pyrite, chalcopyrite, pyrrhotite, and minor amounts of sphalerite and Co -Ni arsenide.
2
CRANDALL, ROBERT W. "The Public Interest in Metals Policy". Mineral Processing and Extractive Metallurgy Review 3, n. 1-4 (marzo 1988): 307–22. http://dx.doi.org/10.1080/08827508808952629.
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Khaled, Azza. "Trace metals in fish of economic interest from the west of Alexandria, Egypt". Chemistry and Ecology 25, n. 4 (agosto 2009): 229–46. http://dx.doi.org/10.1080/02757540903062491.
4
Shen, Hong, Qi Pan, Lili Zhao e Pin Ng. "Risk Contagion between Global Commodities from the Perspective of Volatility Spillover". Energies 15, n. 7 (28 marzo 2022): 2492. http://dx.doi.org/10.3390/en15072492.
Abstract (sommario):
Prices of oil and other commodities have fluctuated wildly since the outbreak of the COVID-19 pandemic. It is crucial to explore the causes of price fluctuations and understand the source and path of risk contagion to better mitigate systemic risk and maintain economic stability. The paper adopts the method of network topology to examine the path of risk contagion between China’s and foreign commodities, focusing on the dynamic evolution and transmission mechanism of risk contagion during the pandemic. This research found that among China’s commodities, energy, grain, and textiles are net recipients of risk contagion, while chemical products and metals are net risk exporters. Among international commodities, industries have positive risk spillover effects on metals and textiles. During the first phase of the pandemic, China’s commodities were the main exporters of risk contagion. However, international industries and metals became the main risk exporters and exerted risk spillover on China’s commodities in the second phase of the pandemic. Moreover, based on total volatility spillover index of commodities, the risk contagion among the commodities follows three paths: “interest rate → commodities → money supply”, “China’s economic expectation → commodities → foreign economic expectation”, and “commodities → consumer confidence”.
5
Sharma, Rahul. "Deep-Sea Mining: Economic, Technical, Technological, and Environmental Considerations for Sustainable Development". Marine Technology Society Journal 45, n. 5 (1 settembre 2011): 28–41. http://dx.doi.org/10.4031/mtsj.45.5.2.
Abstract (sommario):
AbstractMining of minerals such as polymetallic nodules from the deep-sea floor has been “on-hold” as a result of several factors such as current availability of Cu, Ni, Co and Mn from terrestrial sources and their fluctuating prices. Nonetheless, exploration for new resources from deep-sea areas and development of technologies for deep-sea mining have been progressing consistently. These, coupled with recent projections of deep-sea minerals as the alternative source for metals and granting of licenses for exploration and mining of seafloor massive sulfides to private entrepreneurs, indicate the continuing interest and support the perception that such deposits may serve as sources of metals in the 21st century. However, there are several considerations for the sustainable development of deep-sea mining.A typical area of 75,000 km2 with an estimated nodule resource of >200 million tonnes is expected to yield about 54 million tonnes of metals (Mn + Ni + Cu + Co), and the gross in-place value of the metals is estimated to be ∼$21‐42 billion (depending upon the annual rate of mining) in the 20-year life span of a mine site. The decision on the timing to resume mining of these deposits will be based on the prevalent metal prices and rate of returns on the estimated investment of $1.95 billion as capital expenditure and $9 billion as operating expenditure for a single deep-sea mining venture.In view of high investment, technological challenges and economic considerations, private-public cooperation could be an effective means to make deep-sea mining a success. This paper analyzes the current status and discusses the economic, technical, technological, and environmental issues that need to be addressed for sustainable development of deep-sea minerals.
6
Tran, Lan-Huong, Kulchaya Tanong, Ahlame Dalila Jabir, Guy Mercier e Jean-François Blais. "Hydrometallurgical Process and Economic Evaluation for Recovery of Zinc and Manganese from Spent Alkaline Batteries". Metals 10, n. 9 (1 settembre 2020): 1175. http://dx.doi.org/10.3390/met10091175.
Abstract (sommario):
An innovative, efficient, and economically viable process for the recycling of spent alkaline batteries is presented herein. The developed process allows for the selective recovery of Zn and Mn metals present in alkaline batteries. The hydrometallurgical process consists of a physical pre-treatment step for separating out the metal powder containing Zn and Mn, followed by a chemical treatment step for the recovery of these metals. Sulfuric acid was used for the first leaching process to dissolve Zn(II) and Mn(II) into the leachate. After purification, Mn was recovered in the form of MnO2, and Zn in its metal form. Furthermore, during the second sulfuric acid leaching, Na2S2O5 was added for the conversion of Mn(IV) to Mn(II) (soluble in the leachate), allowing Mn to be recovered as MnCO3. Masses of 162 kg of Zn metal and 215 kg of Mn (both in the form of MnO2 and MnCO3) were recovered from one ton of spent alkaline batteries. The direct operating costs (chemicals, labor operation, utilities, energy) and indirect costs (amortization, interest payment) required for a plant treating 8 tons of spent batteries per day was calculated to be $CAD 726 and $CAD 534 per ton, respectively, while the total revenue from the sale of the metals was calculated at $CAD 1359.6 per ton of spent batteries. The development of this type of cost-effective industrial process is necessary for a circular economy, as it contributes to addressing environment- and energy-related issues, and creates opportunities for the economic utilization of metals.
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Liberda, Matěj. "Mixed-frequency Drivers of Precious Metal Prices". Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis 65, n. 6 (2017): 2007–15. http://dx.doi.org/10.11118/actaun201765062007.
Abstract (sommario):
Lack of intrinsic value, hybrid nature of commodities and recent financialization of commodity markets make of understanding precious metals price moves complicated. Predicting future development of precious metals market can be more feasible if we discover what drives these markets and describe nature of the drivers. The aim of the paper is to explain metal price movements by assessing an impact of multiple economic and financial factors. Based on the literature review we study 8 possible macroeconomic and financial drivers. The data are collected from Bloomberg. We use mixed-data-sampling methodology that enables me to study drivers of various frequencies (daily and monthly) simultaneously in a single model. Results show that the interest rate, the exchange rate, stock levels, stock index returns and crude oil returns are generally significant to drive precious metal markets. The stock index has the most significant impact on the metals returns that is negative. Furthermore, the results divide precious metals into two groups with gold and silver on the one hand and platinum and palladium on the other. The first group is worse explained by considered drivers. Moreover, the interest rate does not have any impact on the price development of gold and silver and crude oil returns influence the pair negatively, contrary to the second pair of platinum and palladium.
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BULAKH, Т., L. PLAKHOTNIKOVA e А. TARASENKO. "Management Decisions to Improve Formation and Implementation of the Strategy for the Development of Foreign Economic Relations between Ukraine and Lybia". Scientific Bulletin of the National Academy of Statistics Accounting and Audit, n. 1-2 (1 maggio 2020): 66–73. http://dx.doi.org/10.31767/nasoa.1-2.2020.07.
Abstract (sommario):
Libya is an important trade partner of Ukraine in North Africa. A priority objective for Ukraine in the cooperation with Libya is to diversify energy supplies, whereas Libya shows interest to imports of Ukrainian goods and science & technology services. Studies of performance and trends in foreign economic relations of Ukraine with Libya are, therefore, supposed to enhance the effectiveness of foreign economic policy decisions.
A statistical analysis for the period of 2008–2018 is made using time series on the foreign trade turnover of goods and services between Ukraine and Libya, bilateral trade in goods, bilateral trade in services, the structure of Ukrainian exports of goods to Libya (2018), and the structure of Ukrainian imports of goods from Libya (2018). The data on the structure of the Ukrainian export and import transactions with Libya show that the Ukrainian exports are dominated by agricultural goods, by far and large food products and crops in particular (more than 80% of the total exports), which can caused by nature conditions of the African continent. The remaining share of Ukrainian exports consists of processed raw materials, ferrous metals (nearly 15% of the total exports) and non-ferrous metals, products of oil refinery, chemical products, machinery and equipment, textiles, leather, footwear, foods and beverages etc. The trade balance is positive for Ukraine. Factors hampering the expansion of trade between the two countries are identified: lack of a basic strategy for foreign trade with Libya, lack of a clear strategic vision of the trade cooperation with Libya, heavy political and economic pressures by the Russian Federation, low quality of normative documents for support and promotion of foreign economic interests etc. Management solutions are proposed to improve formation and implementation of the strategy for the development of foreign economic relations between Ukraine and Libya.
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Mpongwana, Ncumisa, e Sudesh Rathilal. "A Review of the Techno-Economic Feasibility of Nanoparticle Application for Wastewater Treatment". Water 14, n. 10 (12 maggio 2022): 1550. http://dx.doi.org/10.3390/w14101550.
Abstract (sommario):
The increase in heavy metal contamination has led to an increase in studies investigating alternative sustainable ways to treat heavy metals. Nanotechnology has been shown to be an environmentally friendly technology for treating heavy metals and other contaminants from contaminated water. However, this technology is not widely used in wastewater treatment plants (WWTPs) due to high operational costs. The increasing interest in reducing costs by applying nanotechnology in wastewater treatment has resulted in an increase in studies investigating sustainable ways of producing nanoparticles. Certain researchers have suggested that sustainable and cheap raw materials must be used for the production of cheaper nanoparticles. This has led to an increase in studies investigating the production of nanoparticles from plant materials. Additionally, production of nanoparticles through biological methods has also been recognized as a promising, cost-effective method of producing nanoparticles. Some studies have shown that the recycling of nanoparticles can potentially reduce the costs of using freshly produced nanoparticles. This review evaluates the economic impact of these new developments on nanotechnology in wastewater treatment. An in-depth market assessment of nanoparticle application and the economic feasibility of nanoparticle applications in WWTPs is presented. Moreover, the challenges and opportunities of using nanoparticles for heavy metal removal are also discussed.
10
Kalinowska, Katarzyna. "Gospodarka na dopingu, czyli jak wywołać kryzys finansowy gospodarki". Gospodarka w Praktyce i Teorii 31, n. 2 (1 gennaio 2012): 43–56. http://dx.doi.org/10.18778/1429-3730.31.04.
Abstract (sommario):
The aim of this paper is empirical analysis of the Austrian theory which points that a monetary shock disturbs relative prices, such as the term structure of interest rates and leads to economic breakdown. Empirical evidence on Austrian Business Cycle is based on some economic crisises from 19th, 20th and 21st century. The paper also points out other than central bank`s monetary policy factors which affect the level of market interest rates.
11
Wood, S. A. "The role of humic substances in the transport and fixation of metals of economic interest (Au, Pt, Pd, U, V)". Ore Geology Reviews 11, n. 1-3 (giugno 1996): 1–31. http://dx.doi.org/10.1016/0169-1368(95)00013-5.
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Davenport, Alison J. "In Situ Corrosion Studies". Electrochemical Society Interface 7, n. 1 (1 marzo 1998): 28–29. http://dx.doi.org/10.1149/2.f06981if.
Abstract (sommario):
The corrosion of metals has a major economic impact, yet the underlying processes that control the phenomenon are very difficult to study. Removal of a corroded sample from its wet environment can change it, so the results of subsequent ex situ characterization may be artifacts. In recent years, there has been considerable interest in the development of in situ techniques that allow examination of metal surfaces during the corrosion process; a few examples of such studies are given here.
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MOKNI, KHALED. "EMPIRICAL ANALYSIS OF THE RELATIONSHIP BETWEEN OIL AND PRECIOUS METALS MARKETS". Annals of Financial Economics 13, n. 01 (marzo 2018): 1850003. http://dx.doi.org/10.1142/s2010495218500033.
Abstract (sommario):
The relationship between crude oil and precious metals has been a major issue in economic and financial literature. In this paper, the FIEGARCH-copula framework was used to investigate the co-movements not only between returns, but also between volatilities and market risks among crude oil and precious metals markets. Based on daily crude oil and the major precious metals prices from January 2, 2000 to December 31, 2016, our empirical results are as follows: First, a significant positive and asymmetric relationship between oil and precious metals returns, volatilities and market risk was detected. Second, the dependence structure between oil-silver and oil-gold for returns and volatilities are time varying, while the other pairs are characterized by constant dependence. Third, based on the dependence modeling between daily Value-at-Risk (VaR) for the long and short trading position, empirical results show that the market risk relationship between crude oil and precious metals change over time and increase with VaR’s confidence level. Our findings are of interest for investors and risk managers in portfolio’s design and allow for a reliable framework for returns and risk prediction.
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Lebedev, Nikita A. "SELECTED AREAS OF DEVELOPMENT OF THE PRECIOUS ASSETS MARKET AS A FINANCIAL INSTITUTION IN THE ASPECT OF SUPPORTING SUSTAINABLE ECONOMIC GROWTH". EKONOMIKA I UPRAVLENIE: PROBLEMY, RESHENIYA 2/5, n. 134 (2023): 69–75. http://dx.doi.org/10.36871/ek.up.p.r.2023.02.05.010.
Abstract (sommario):
In the article presented to the readers, some issues of the development of the precious assets market are considered. Such areas as investment coins made of precious metals, operations with natural and synthetic precious stones, transactions with precious nuggets, depersonalized metal accounts, digital currency introduced into circulation are briefly analyzed. It is shown that precious assets as a financial institution are becoming a factor in supporting sustainable economic growth, as is the digital currency being introduced, linked to the global gold exchange rate, and which, from the point of view of the Bank of Russia, also contributes to economic growth, which in relation to the precious asset market includes interest in long-term investments for various groups of investors.
15
Matys, Sabine, Franziska L. Lederer, Nora Schönberger, Robert Braun, Falk Lehmann, Katrin Flemming, Stefanie Bachmann, Susan Curtis, Ross T. A. MacGillivray e Katrin Pollmann. "Phage Display - A Promising Tool for the Recovery of Valuable Metals from Primary and Secondary Resources". Solid State Phenomena 262 (agosto 2017): 443–46. http://dx.doi.org/10.4028/www.scientific.net/ssp.262.443.
Abstract (sommario):
The development of effective and ecofriendly processes for the recovery of critical elements poses a challenge for scientists all over the world. A novel approach is the generation of highly specific peptides that bind with high affinity to individual elements of interest. The peptides are selected by phage surface display (PSD) technology. In this study, PSD technology has been applied in two different approaches. The focus of the first approach was the identification of peptides that bind specifically to special particles of interest that are part of electronic scrap aiming towards the development of new recycling processes. In the second approach, metal ion binding peptides were isolated via PSD to use them for the targeted removal and enrichment of these elements from complex leaching solutions or from industrial waters. To address the economic production of peptides, the development of a new expression system is also part of this study.
16
Abralava, Anzor. "The System of Quantitative Risk Assessment Indicators and Their Economic Efficiency Assessment Methods". Works of Georgian Technical University, n. 1(531) (22 marzo 2024): 63–68. http://dx.doi.org/10.36073/1512-0996-2024-1-63-68.
Abstract (sommario):
The mathematical models of the company's optimal risk management mechanism ensure the maximum efficiency of the activity at the level of risk acceptable to the enterprise. Classification of risks into operational risk and interest risk is given. One of the possible options for determining the tasks of optimal planning of the enterprise is presented, which includes restrictions on the values of operational effect (OE) (OR). The OE (two) indicator is considered as a limitation, the normative value of which can be considered as a given value during planning. It is a multidimensional linear optimal planning problem with linear constraints. Its size is determined by the number of product types in the enterprise. We have formulated original economic-mathematical models of the distribution type, which are used to create the optimal production plan of the enterprise. In order to minimize the interest risk, we have used the duration indicator analysis method. Duration represents the elasticity of the price of a financial instrument (in this case the present value of a stream of payments) with respect to the interest rate (discount rate) and is therefore a measure of the risk of the price of the instrument changing when the interest rate changes.
17
Sarvari, Reza, Ehsan Khansalar e Mohammad Delkhosh. "The Effect of Macroeconomic Variables on Accounting Profit Transparency (Case Study: Basic Metals Industry Companies Listed on Tehran Stock Exchange)". International Journal of Economics and Finance 8, n. 6 (24 maggio 2016): 219. http://dx.doi.org/10.5539/ijef.v8n6p219.
Abstract (sommario):
The purpose of the present study is to analyze the influence of economic factors on accounting profit transparency. Economic factors consist of economic growth, liquidity growth rate, annual deposit interest rate, currency, and inflation rate. In this research in order to determine profit transparency Barth et al. (2008) model has been implemented. This model defines transparency as the simultaneous change of profit and profit changes along with stocks feedback. The data are quantitative and at relative scale which depend on regression analysis and interpretation and Pearson correlation factor. To this end, research hypotheses have been tested by implementing apposite statistic methods by the use of SPSS software. Macroeconomic variables values have been collected from the data published by the central bank. The research population consists of basic metals industry companies listed on Tehran Stock Exchange during 2009-2014. The research findings show that there is a significant and positive relationship between macroeconomic variables under the present study and that of dependent variable of profit transparency.
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Liu, Qiang, Xufang Liu e Bin Li. "Base-Metal-Catalyzed Olefin Isomerization Reactions". Synthesis 51, n. 06 (19 febbraio 2019): 1293–310. http://dx.doi.org/10.1055/s-0037-1612014.
Abstract (sommario):
The catalytic olefin isomerization reaction is a highly efficient and atom-economic transformation in organic synthesis that has attracted tremendous attention both in academia and industry. Recently, the development of Earth-abundant metal catalysts has received growing interest owing to their wide availability, sustainability, and environmentally benign nature, as well as the unique properties of non-precious metals. This review provides an overview of a broad range of base-metal-catalyzed olefin isomerization reactions categorized according to their different reaction mechanisms.1 Introduction2 Base-Metal-Catalyzed Olefin Isomerization Reactions3 Base-Metal-Catalyzed Cycloisomerization Reactions4 Conclusion
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Veit, Hugo Marcelo, Nichele Cristina de Freitas Juchneski e Janine Scherer. "Use of gravity separation in metals concentration from printed circuit board scraps". Rem: Revista Escola de Minas 67, n. 1 (marzo 2014): 73–79. http://dx.doi.org/10.1590/s0370-44672014000100011.
Abstract (sommario):
The amount of solid waste generated by all segments of society has increased in past decades. Annually, in Brazil, 96,000 tonnes of electronic scrap are generated from computers. The incorrect disposal of this waste creates environmental damage, generating loss of materials that could be reused and / or recycled, reducing the extraction of recyclable materials to produce new materials. The printed circuit boards (PCB) represent approximately 30% of the electronic waste generated and its recycling is a complex process, but very important for the recovery of metals of high economic value. Industrial processes for the recovery of metals from PCB are based on pyrometallurgy and hydrometallurgy. In both cases, it is possible to carry out a pretreatment that involves the use of mechanical processes. Therefore, for this paper, the concentration of the metallic fraction of PCB through the use of a Mozley concentrator was enabled. The results show that it is possible to obtain significant quantities of metals such as copper (concentration 85%), tin (95%), and silver (98%) in the fractions of interest.
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MYASOEDOV, SERGEY ALEXSANDROVICH. "TRENDS IN THE ECONOMIC DEVELOPMENT OF THE PROCESSES OF CONSUMPTION OF PLATINUM GROUP METALS". Messenger AmSU, n. 95 (2021): 101–6. http://dx.doi.org/10.22250/jasu.95.20.
Abstract (sommario):
The paper substantiates and groups the main directions of consumption in the world of platinum group metals; identifies and summarizes the main instruments of state industrial policy in the field of subsoil use. In the course of the study, it was revealed that the Russian Federation does not fully use the tools to protect national interests in the system of extraction and processing of platinum group metals. The main guideline of state policy should be the creation of vertically integrated organizations in this area and the formation of high-tech facilities and industries that ensure the full consumption of extracted platinoids by the industry of the Russian Federation.
21
Rumyk, Ihor, Volodymyr Kuzminsky, Olha Pylypenko e Oksana Yaroshenko. "PRECIOUS METALS MARKET FORECASTING IN THE CURRENT ENVIRONMENT". Economics, Finance and Management Review, n. 1(17) (30 marzo 2024): 45–56. http://dx.doi.org/10.36690/2674-5208-2024-1-45.
Abstract (sommario):
The article analyzes trends in the precious metals market. The general characteristics and assessment of the most popular precious metals are given. The key factors influencing the supply and demand of precious metals are analyzed. Precious metals market forecasts have been developed. An analysis of the state of the world gold market in recent years has been carried out. Using the method of comparative analysis, modern trends in the supply and demand of this precious metal were revealed. The dynamics and structure of world gold reserves are considered. The world's precious metal reserves in different countries were also studied. The potential gold reserves in Ukraine are estimated. The production of precious metals in the world was studied. The rating of countries producing precious metals has been compiled. The leaders in this field have been identified based on the criteria of production capacities and growth rates of precious metals extraction. The structure of consumption of precious metals in the world is analyzed. The factors that lead to an increase in the rate of consumption of precious metals in modern conditions are considered. In particular, an increase in the current rate of commissioning of new solar energy capacities and an increase in the use of electric transport have been identified, which has significantly increased the demand for precious metals in the world. The impact on price dynamics of geopolitical and other economic factors, such as changes in trade relations between countries, currency fluctuations, market crises, changes in the monetary policy of central banks in many countries, and, above all, the increase in interest rates by the US Federal Reserve, was also studied. Considering these and other influencing factors, forecasts of the price dynamics of the precious metals market for 2024 and subsequent years were developed using a graphical method.
22
Stachowicz, Feliks, Beata Pawłowska e Marta Wójcik. "HYDROMETALLURGICAL METHOD OF SELECTED MET-ALS RECOVERY FROM SEWAGE SLUDGE ASHES". Acta Metallurgica Slovaca 23, n. 4 (4 dicembre 2017): 296. http://dx.doi.org/10.12776/ams.v23i4.991.
Abstract (sommario):
<p class="Metallographymaintext"><em>With the increasing number of new residents attached to the sewerage system, the amount of generated sewage sludge is systematically growing. In line with the restriction placed on landfill waste with a calorific value above 6 MJ/kg introduced on 1 January 2016, the most popular sewage sludge utilization methods are thermal processes and agricultural use. In recent years, there has been increased interest in using thermal sewage sludge utilization methods. The major problem associated with sludge combustion is the enormous amount of by-products, particularly ashes. </em><em>Due to the specific characteristics, it is necessary to develop new sewage sludge ashes utilization methods in line with economic, law and environmental requirements. </em><em>Sewage sludge ashes are rich in valuable metals, particularly in zinc, copper and iron. As utilization methods of sewage sludge ashes do not guarantee the metals recovery until now, metals are lost irretrievably. This article presents hydrometallurgical methods of metals recovery from sewage sludge ashes with the use of acid leaching. The aforementioned propositions are beneficial from the economical and environmental point of view because they prevent valuable metals from waste. Additionally, the whole undertaking could contribute to the popularization of sustainable development.</em></p>
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Peric-Grujic, Aleksandra, Viktor Pocajt e Mirjana Ristic. "Determination of heavy metal concentrations in tea samples taken from Belgrade market, Serbia". Chemical Industry 63, n. 5 (2009): 433–36. http://dx.doi.org/10.2298/hemind0905433p.
Abstract (sommario):
Tea is one of the world's most popular beverages. Economic and social interest in tea is clear from the fact that about 18-20 billion tea cups are being consumed daily in the world. Consequently, chemical components in tea leaves have received great interest because they are related to health and disease. Various reports have discussed the potential health implications of some chemical factors such as heavy metals in tea, particularly since tea bush is known to accumulate trace metals. Metallic constituents of tea leaves depend on the type of tea and geological origin. In the present study four tea samples (two black and two green) and four herbal tea samples (two Mentha piperita and two Matricaria chammomilla) were collected from the local market in Belgrade, Serbia, in May 2008. The sample preparation has been performed using wet and dry digestion procedures. The metal content (Cu, Zn, Mn, Cd, Ni and Pb) in the digested samples has been analyzed by using flame atomic absorption spectrometry. The comparison of wet and dry digestion has shown significant differences in results, indicating that dry digestion is more appropriate method. The levels of the examined metals obtained by dry digestion in this study compared well with those reported for tea samples from some other parts of the world. Among the investigated metals, the most abundant nutritive metal, Mn, has been the highest with 26.0 to 199.3 mg/kg, while fortunately toxic heavy metal, Cd, has been below the detection limit (0.1 mg/kg). The concentrations of lead and nickel have been in the range 5.1-13.7 and 1.4- -4.4, respectively. The content of lead in two samples (Mentha piperita) has been higher than the maximum permissible concentration of 10 mg/kg specified by the national legislation.
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Akinruli, I. J., Philips Olatunde Ogunode e Temitope Sunday Olowe. "Exploring the Determinants of the Demand for Pottery Products in Nigeria for National Economic Advancement". International Journal of Business and Management Review 11, n. 8 (15 agosto 2023): 46–53. http://dx.doi.org/10.37745/ijbmr.2013/vol11n84653.
Abstract (sommario):
The obvious decline in the demand for pottery wares in Nigeria is worrisome as the trend is pushing many potters out of business. Meanwhile the nation needs to harness all its resources for economic growth, but the pottery, through which the resources could be exploited seem not to enjoy patronage. In this work, literatures were reviewed to fathom the determinant for the demand for pottery. It was discovered that the attributes of the pottery wares, price of alternative imported pottery wares, and that of vessels made of materials other than clay, effect of poor advertisement, taste, interest and orientation, and the income of the consumers are the major determinants for the demand for pottery wares. Homemade tiles, personalized pottery, and ceremonial wares are pots with unique selling points identified for the potters to engage in. The Nigerian potters needs to improve on the qualities of their products in order to compete favourably with imported wares and wares made of plastics and metals at the market.
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Rezun, Miron. "L’Union soviétique et les minerais stratégiques : Erreurs et vérités". Études internationales 18, n. 4 (12 aprile 2005): 739–60. http://dx.doi.org/10.7202/702250ar.
Abstract (sommario):
This is an analysis of the major strategic minerals (sometimes called strategic materials), including some of the precious metals, which are vital to the Western economies. It focuses primarily on Soviet strategic minerals policies and examines the conflicting hypotheses for and against a resource war waged by the Soviet Union. The conclusions reached on the strength of the evidence so far is that Soviet policies have been chiefly economic and motivated by economic self-interest ; the Soviet Union is seen as an eager competitor for markets to acquire hard currency and not as a power eager to deprive the West of critical resources. A case is also made for the increasing importance of materials science, ocean mining and substitution, which is likely to make the West, including the USSR, invulnerable to supply disruptions in the future.
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Umarova, Tatyana. "Influence of Microalloying (Including Rare-Earth Metals) on the Phase Composition and Properties of Aluminum Alloys". Materials Science Forum 890 (marzo 2017): 331–38. http://dx.doi.org/10.4028/www.scientific.net/msf.890.331.
Abstract (sommario):
In connection with the search for new materials and the more extensive use of metals and alloys with special physical and chemical properties, rare-earth metals (REMs) are attracting increasing interest not only as alloying additives but also as the main components of structural materials. The Al-Fe alloys are of great practical interest, and the purpose of this work was to study the influence of microalloying by REMs on the mechanical and acoustic damping properties of Al-Fe alloys. REMs were selected as alloying components because of their properties and their widespread use in improving the structure and properties of structural alloys, including mechanical and acoustic damping properties. The results of these investigations are expected to enable the use of secondary Al (i.e., waste Al manufacture with a high Fe impurity concentration) as a base material for the development of structural alloys with improved mechanical properties for use in mechanical and electrical engineering applications. The use of secondary Al will provide economic advantages and will contribute to the conservation of resources.This work is actual because Al alloyed with Fe and REMs can be used as corrosion-resistant materials and conductive materials in electronics and for automotive and aircraft engines, wires, cables, rods, tires and other products of the electrical engineering industry, thus expanding the scope of applications of these alloys [1-4].
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Nugroho, Bayu Pratama. "Implementasi Sistem Untuk Prediksi Harga Emas". Jurnal SAINTEKOM 8, n. 2 (19 settembre 2018): 90. http://dx.doi.org/10.33020/saintekom.v8i2.56.
Abstract (sommario):
Gold is one of the investment commodities whose value continues to increase from year to year. The rise in gold prices will encourage investors to choose to invest in gold rather than the capital market. Investment in gold gives better results for the long term and with better purchasing power, so gold investment is an effective solution considering the value of money annually eroded by inflation. Such a state of economic instability is what drives many people, organizations and companies to invest in gold precious metals. Factors influencing the rise or fall of gold price according to Riefiyono (2010) are change of exchange rate (dollar exchange rate to rupiah), world political situation, domestic economic situation, and interest rate.
The method used in this case is K-Nearest Neighbor (KNN) is a method that uses In the training phase, this algorithm only retains feature vectors and sample training data classification. In the classification phase, the same features are calculated for testing data (whose classification is unknown).
The results obtained are successfully made an application for the prediction of gold prices by utilizing the method of Nearest Neighbor Retrieval. This application can help users in knowing the gold price prediction results are expensive or cheap with views in terms of economic situation, interest rates, political situation, and changes in exchange rates.
28
Aznar-Sánchez, José, Juan Velasco-Muñoz, José García-Gómez e María López-Serrano. "The Sustainable Management of Metals: An Analysis of Global Research". Metals 8, n. 10 (8 ottobre 2018): 805. http://dx.doi.org/10.3390/met8100805.
Abstract (sommario):
The objective of this study was to analyze research trends in the field of sustainable management of metals on a global level between 1993 and 2017. To do so, a bibliometric analysis was carried out on a total of 6967 articles. The results revealed the growing interest in this research field, particularly over the last five year-period during which 63% of all articles were published. The three journals in which most articles had been published were the Journal of Cleaner Production, ACS Sustainable Chemistry and Engineering, and Chemsuschem. The countries that published the most articles were China, the United States, India, Germany, and the United Kingdom. A sizeable network of collaboration has been established between countries for the joint publication of studies. The main lines of research have been focused on metal decontamination in water and soil, waste management oriented towards reuse and recycling, and the innovation of processes for cleaner and more efficient production. The results revealed the need for comprehensive studies that integrate different disciplines within the same analytical framework, and to promote research that contributes to the different dimensions of sustainability (environmental, economic, and social).
29
Yu, Xiaohui, Jiguang Deng, Yuxi Liu, Lin Jing, Zhiquan Hou, Wenbo Pei e Hongxing Dai. "Single-Atom Catalysts: Preparation and Applications in Environmental Catalysis". Catalysts 12, n. 10 (14 ottobre 2022): 1239. http://dx.doi.org/10.3390/catal12101239.
Abstract (sommario):
Due to the expensive price and the low reserve of noble metals in nature, much attention has been paid to single-atom catalysts (SACs)—especially single-atom noble metal catalysts—owing to their maximum atomic utilization and dispersion. The emergence of SACs greatly decreases the amount of precious metals, improves the catalytic activity, and makes the catalytic process progressively economic and sustainable. However, the most remarkable challenge is the active sites and their stability against migration and aggregation under practical conditions. This review article summarizes the preparation strategies of SACs and their catalytic applications for the oxidation of methane, carbon monoxide, and volatile organic compounds (VOCs) and the reduction of nitrogen oxides. Furthermore, the perspectives and challenges of SACs in future research and practical applications are proposed. It is envisioned that the results summarized in this review will stimulate the interest of more researchers in developing SACs that are effective in catalyzing the reactions related to the environmental pollution control.
30
Dubey, Prashant, Shashank Sundriyal e Priyanka Maheshwari. "An-All-Solid State Supercapacitor Device from E-Waste Derived Activated Carbon". ECS Meeting Abstracts MA2023-02, n. 9 (22 dicembre 2023): 992. http://dx.doi.org/10.1149/ma2023-029992mtgabs.
Abstract (sommario):
Recycling solid waste has substantial economic and environmental advantages. Electronic waste (e-waste) has the complex intrinsic trait of combining metals and non-metals contained in the same waste stream, which limits the recycling technologies that are now available for it. Much interest has been created by the outstanding surface and conductive qualities of carbon-based materials made from waste. In this article, we transformed e-waste (end of life keyboard) into highly porous activated carbon for its application as high-performance electrode material for supercapacitor. The as-synthesized activated carbon is characterized via material characterization techniques such as XRD, Raman, FTIR and BET. E-waste derived porous carbon (EWPC) rendered decent electrochemical performance in 1M H2SO4 electrolyte. Furthermore, an-all-solid-state symmetric supercapacitor device (EWPC//EWPC) has been fabricated and recorded convincing results in terms of energy density, power density, and cyclic stability. Hence, this study open up new avenues for recovering and creating high-performance, environmentally friendly materials from discarded e-wastes.
31
Coelho, Daniel Gomes, Claudio Sergio Marinato, Letícia Paiva Matos, Heloísa Monteiro Andrade, Vinicius Melo Silva, Pedro Henrique Santos Neves e Juraci Alves Oliveira. "Evaluation of Metals in Soil and Tissues of Economic‐Interest Plants Grown in Sites Affected by the Fundão Dam Failure in Mariana, Brazil". Integrated Environmental Assessment and Management 16, n. 5 (6 aprile 2020): 596–607. http://dx.doi.org/10.1002/ieam.4253.
32
Gaspar, O., J. F. W. Bowles e T. J. Shepherd. "Silver mineralization at the Vale das Gatas tungsten mine, Portugal". Mineralogical Magazine 51, n. 360 (giugno 1987): 305–10. http://dx.doi.org/10.1180/minmag.1987.051.360.13.
Abstract (sommario):
AbstractThe Vale das Gatas tungsten mine is situated at the contact between Hercynian granite and Cambrian-Precambrian crystalline schists a few kilometers north of the village of Sabrosa, near Vila Real, in northern Portugal. Wolframite has been the principal product of the mine although several other metals of economic interest are known to occur there. The silver content of the ores was attributed by earlier workers to the presence of tetrahedrite and schapbachite, whilst this work shows matildite, pavonite, acanthite, and argyrodite to be present, together with Ag-bearing galena. The textures and compositions of these phases are described with preliminary results of fluid inclusion studies.
33
Iwaszczuk, Natalia, Agata Wzorek e Bartosz Łamasz. "Relationship between Copper Price and Selected Metals Prices". Key Engineering Materials 682 (febbraio 2016): 336–41. http://dx.doi.org/10.4028/www.scientific.net/kem.682.336.
Abstract (sommario):
This paper focuses on the factors that influence the changes in copper prices. A brief review of the literature showed several areas of interests of researchers, such as global economic situation and development of Asian countries. This paper draws attention to concurrent price trends, some pairs of raw materials (e.g. copper – aluminum, copper – silver, even copper – palladium). This paper uses multiple regression model containing monthly data spanning from January 2012 to June 2015, which consist of 42 observations for metals: copper, zinc, aluminum, silver, gold, platinum and palladium. And it shows a strong relationship between the prices of copper and other metals.
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Sakellariadou, Fani, Francisco J. Gonzalez, James R. Hein, Blanca Rincón-Tomás, Nikolaos Arvanitidis e Thomas Kuhn. "Seabed mining and blue growth: exploring the potential of marine mineral deposits as a sustainable source of rare earth elements (MaREEs) (IUPAC Technical Report)". Pure and Applied Chemistry 94, n. 3 (4 febbraio 2022): 329–51. http://dx.doi.org/10.1515/pac-2021-0325.
Abstract (sommario):
Abstract The expected growth of the global economy and the projected rise in world population call for a greatly increased supply of materials critical for implementing clean technologies, such as rare earth elements (REEs) and other rare metals. Because the demand for critical metals is increasing and land-based mineral deposits are being depleted, seafloor resources are seen as the next frontier for mineral exploration and extraction. Marine mineral deposits with a great resource potential for transition, rare, and critical metals include mainly deep-sea mineral deposits, such as polymetallic sulfides, polymetallic nodules, cobalt-rich crusts, phosphorites, and rare earth element-rich muds. Major areas with economic interest for seabed mineral exploration and mining are the following: nodules in the Penrhyn Basin-Cook Islands Exclusive Economic Zone (EEZ), the Clarion–Clipperton nodule Zone, Peru Basin nodules, and the Central Indian Ocean Basin; seafloor massive sulfide deposits in the exclusive economic zones of Papua New Guinea, Japan, and New Zealand as well as the Mid-Atlantic Ridge and the three Indian Ocean spreading ridges; cobalt-rich crusts in the Pacific Prime Crust Zone and the Canary Islands Seamounts and the Rio Grande Rise in the Atlantic Ocean; and the rare earth element-rich deep-sea muds around Minamitorishima Island in the equatorial North Pacific. In addition, zones for marine phosphorites exploration are located in Chatham Rise, offshore Baja California, and on the shelf off Namibia. Moreover, shallow-water resources, like placer deposits, represent another marine source for many critical minerals, metals, and gems. The main concerns of deep-sea mining are related to its environmental impacts. Ecological impacts of rare earth element mining on deep-sea ecosystems are still poorly evaluated. Furthermore, marine mining may cause conflicts with various stakeholders such as fisheries, communications cable owners, offshore wind farms, and tourism. The global ocean is an immense source of food, energy, raw materials, clean water, and ecosystem services and suffers seriously by multiple stressors from anthropogenic sources. The development of a blue economy strategy needs a better knowledge of the environmental impacts. By protecting vulnerable areas, applying new technologies for deep-sea mineral exploration and mining, marine spatial planning, and a regulatory framework for minerals extraction, we may achieve sustainable management and use of our oceans.
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Robben, C., A. Moslemiyekan e K. Esbensen. "X-ray computed tomography (XCT) for characterization of particulate materials heterogeneity: embrace heterogeneity — create value with separation". TOS Forum 2022, n. 11 (27 maggio 2022): 442. http://dx.doi.org/10.1255/tosf.173.
Abstract (sommario):
Value created by mineral beneficiation processes relies on physical separation (including flotation) of particles containing different grades of metals or minerals of economic interest. The value created is a direct consequence of exploiting heterogeneity as governed by the properties of the natural resource that is processed, most often starting by well-controlled size reduction processes, e.g. blasting, crushing and grinding. These are usually applied in a stepwise fashion before the separation stage exploiting the liberated mineral(s) of economic interest. While material heterogeneity usually is a property that must be managed (reduced) by mixing and blending to stabilize sampling and optimize extraction processes, it can also be the fundament for creating value by first increasing liberated heterogeneity to allow effective sorting to come into play. To calibrate value-adding physical separation processes it is necessary to be in complete control of material heterogeneity, as part of characterization of the original natural resource. Optimal physical separation is based on relevant sampling, Theory of Sampling (TOS). However, this is currently done with labour intensive processes conducted with highest precision but notably most often only using small sample masses, often leaving accuracy be the wayside. This contribution shows that TOS is a prime factor, as is representative heterogeneity characterization, necessary for optimizing mineral beneficiation processes.
36
Bohlen, Jan, Dietmar Letzig e Karl Ulrich Kainer. "New Perspectives for Wrought Magnesium Alloys". Materials Science Forum 546-549 (maggio 2007): 1–10. http://dx.doi.org/10.4028/www.scientific.net/msf.546-549.1.
Abstract (sommario):
In view of the increasing needs for efficient usage of natural resources and environmental protection in our modern society, weight reduction in transportation such as cars, trains or aircrafts is of fundamental interest. In order to solve this major issue, improved concepts are necessary which also emphasize the usage of light weight materials in construction. Especially magnesium and its alloys as the lightest available constructional metals have a major potential in this regard. Since magnesium cast components have found their application, interest is now spreading towards wrought alloys for use as structural components. However, the use of wrought magnesium alloys in the transportation industry is still limited at present. In this paper we give an overview on the present state of the art as well as on specific requirements for the processing of wrought magnesium alloys. We will show the technical potential in terms of improved economic aspects for wrought magnesium and discuss research topics such as process-specific alloy design.
37
Semeyutin, Artur, e Gareth Downing. "Co-jumps in the U.S. interest rates and precious metals markets and their implications for investors". International Review of Financial Analysis 81 (maggio 2022): 102078. http://dx.doi.org/10.1016/j.irfa.2022.102078.
38
Tolkou, Athanasia K., Ioannis A. Katsoyiannis e Anastasios I. Zouboulis. "Removal of Arsenic, Chromium and Uranium from Water Sources by Novel Nanostructured Materials Including Graphene-Based Modified Adsorbents: A Mini Review of Recent Developments". Applied Sciences 10, n. 9 (7 maggio 2020): 3241. http://dx.doi.org/10.3390/app10093241.
Abstract (sommario):
Groundwater is commonly used as a drinking water resource all over the world. Therefore, groundwater contamination by toxic metals is an important issue of utmost concern for public health, and several technologies are applied for their effective removal, such as coagulation, ion exchange, adsorption, and membrane applications like reverse osmosis. Adsorption is acknowledged as a simple, effective and economic technology, which has received increased interest recently, despite certain limitations regarding operational applications. The respective scientific efforts have been specifically focused on the development and implementation of novel nano-structured adsorbent materials, which may offer extensive specific surface areas, much higher than the conventional adsorbents, and hence, are expected to present higher removal efficiencies of pollutants. In this paper, the recent developments of nanomaterial applications for arsenic, chromium and uranium removal from groundwaters are critically reviewed. Particularly, the use of novel composite materials, based mainly on hybrid metallic oxide nanoparticles and on composites based on graphene oxide (GO) (i.e., graphene-based hybrids), showed promising evidences to achieve efficient removal of toxic metals from water sources, even in full scale applications.
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Barrell, R. J., e Andrew Gurney. "Chapter II. The World Economy". National Institute Economic Review 129 (agosto 1989): 22–37. http://dx.doi.org/10.1177/002795018912900103.
Abstract (sommario):
Our recent forecasts have warned of growing inflationary pressures in the world economy. The policy response to these has been robust, and interest rates have risen markedly over the last year; consequently there are now signs that inflationary pressures are receding. Chart 1 illustrates the recent interest-rate developments, and chart 2 recent and prospective inflation rates for the major 4 economies. Oil prices have weakened over the last three months, and commodity prices, especially those for metals and minerals, have been falling.
40
Pokhitonov, Yu A., e I. G. Tananaev. "Prospects for the Use of Palladium from NPP Spent Nuclear Fuel and Ways to Design the Technology of its Recovery at a Radiochemical Enterprise". Radiochemistry 64, n. 3 (giugno 2022): 270–79. http://dx.doi.org/10.1134/s106636222203002x.
Abstract (sommario):
Abstract The removal of platinoids (Pd, Rh, and Ru) from irradiated fuel the yield of which is kilograms per ton is a complex problem due to a number of technological and economic reasons. The paper proposes ways of a phased approach to the introduction of technology for the recovery of platinum-group metals (PGM) at one of the radiochemical enterprises. Information is presented on the dynamics of production volume and prices of PGMs in the world over the past decades and on the possibility of using reactor platinoids in various fields. According to the authors, it is of interest to consider the problem of isolating and using reactor Pd in hydrogen power engineering and in the processing of waste from radiochemical enterprises.
41
Rougemont, Françoise, e Juan-Pablo Vita. "Obligations de travail dans les économies palatiales du Bronze récent". Altorientalische Forschungen 48, n. 1 (8 giugno 2021): 125–49. http://dx.doi.org/10.1515/aofo-2021-0009.
Abstract (sommario):
Abstract Palatial economic archives from various regions — from the Aegean world to Mesopotamia — and from various periods of the Bronze Age, attest to the use by palatial administrations of procedures in which workers were obliged to perform a task, whether craft or agricultural, on behalf of the palace. This article examines the possibility that such a procedure existed also in Ugarit, since a group of administrative texts relating to metals appear comparable to these systems of work-assignments. The material from Ugarit and the conclusions reached allow, then, a comparison with the system of work-assignment attested in the Mycenaean texts and called ta-ra-si-ja. Mycenaean and Ugaritic documentations present typological, structural and chronological analogies, which add to the interest of the comparison.
42
Sharma, Rahul. "Polymetallic Nodules: Resource Potential and Mining Prospects". Marine Technology Society Journal 55, n. 6 (30 dicembre 2021): 22–30. http://dx.doi.org/10.4031/mtsj.55.6.8.
Abstract (sommario):
Abstract Deep-sea minerals such as polymetallic nodules have attracted significant interest among stakeholders not only for evaluating their potential as an alternative source of critical metals that are required for various industrial applications including green energy but also in developing technology for their exploitation. There has been a steady increase in the number of contractors having exploration rights over large tracts on the seafloor in the “Area,” and the International Seabed Authority that is mandated with the responsibility of regulating such activities is in the process of preparing a code for exploitation of these deep-sea minerals. This commentary takes a look at the resource potential and mining prospects of polymetallic nodules while addressing the economic and environmental issues associated with them.
43
Ericsson, Magnus, Olof Löf e Anton Löf. "Chinese control over African and global mining—past, present and future". Mineral Economics 33, n. 1-2 (luglio 2020): 153–81. http://dx.doi.org/10.1007/s13563-020-00233-4.
Abstract (sommario):
Abstract Chinese companies are far from taking control over African or global mining. In 2018, they control less than 7% of the value of total African mine production. Chinese investments in African mining of non-fuel minerals between 1995 and 2018 have contributed to production growth but it has also increased Chinese control over African mineral and metal production. There is evidence pointing to a continued Chinese expansion in African minerals and metals but at a slower pace than in the past decade. Through a detailed analysis of every mine, fully or partially controlled by Chinese interest in Africa and all other parts of the world the paper also measures total Chinese control over global mine production to be around 3% of the total value.
44
Dr. Cirappa I B e Tejashwini K C. "A Study on Derivative Market in India". International Journal of Engineering and Management Research 12, n. 3 (13 giugno 2022): 97–101. http://dx.doi.org/10.31033/ijemr.12.3.13.
Abstract (sommario):
Since 1991, thanks to economic policy liberalization, the Indian economy has entered an era in which Indian businesses can no longer disregard global markets. Prior to the 1990s, the prices of a variety of commodities, metals, and other assets were carefully regulated. Others, which were not rolled, were primarily dependant on regulated input costs. As a result, there was no uncertainty and, as a result, no price fluctuations. However, in 1991, when the process of deregulation began, the prices of most items were deregulated. It has also resulted in the exchange being partially deregulated, easing trade restrictions, lowering interest rates, and making significant advancements in foreign institutional investors' access to the capital markets, as well as establishing market-based government securities pricing, among other things. Furthermore, portfolio and securities price volatility and instability were influenced by market-determined exchange rates and interest rates. As a result, hedging strategies employing a variety of derivatives were exposed to a variety of risks. The Indian capital market will be examined in this study, with a focus on derivatives.
45
Fernandes, Kirlene Salgado, Evandro de Azevedo Alvarenga, Paulo Roberto Gomes Brandão e Vanessa de Freitas Cunha Lins. "Infrared-spectroscopy analysis of zinc phosphate and nickel and manganese modified zinc phosphate coatings on electrogalvanized steel". Rem: Revista Escola de Minas 64, n. 1 (marzo 2011): 45–49. http://dx.doi.org/10.1590/s0370-44672011000100005.
Abstract (sommario):
Hopeite-type phosphate coatings in which zinc is partially replaced by other metals like manganese and nickel are of great interest for the automotive and home appliance industries. Such industries use phosphate conversion coatings on galvanized steels in association with cataphoretic electropainting. Zinc phosphates modified with manganese and nickel are isomorphic with the hopeite, and the phase identification using X-ray diffraction is difficult. In this paper, the phosphate coatings are identified using the Fourier transform infrared spectroscopy (FTIR).
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Dias, Rui, Rosa Galvão e Paulo Alexandre. "Precious metals as hedging assets: Evidence from MENA countries". Investment Management and Financial Innovations 21, n. 1 (5 febbraio 2024): 157–67. http://dx.doi.org/10.21511/imfi.21(1).2024.13.
Abstract (sommario):
In the context of the global pandemic of 2020 and the Russian invasion of Ukraine in 2022, a newfound interest is emerging in understanding the interconnections between the Dow Jones (United States), Amman SE General (Jordan), BLSI (Lebanon), EGX 30 (Egypt), ISRAEL TA 125 (Israel), MASI (Morocco), and MOEX (Russia) indices and the precious metals markets Gold Bullion LBM, Silver, Handy &amp; Harman, London Platinum, from January 1, 2018 to November 23, 2023. The study aimed to determine whether precious metals such as Gold, Silver, and Platinum can be considered hedging assets to the stock markets of the Middle East and North Africa (MENA) countries, i.e., whether investors operating in these regional markets can rebalance their portfolios with these precious metals. The structural vector autoregressive (SVAR) methodology allowed assessing the influence of the analyzed markets on each other regarding price formation. The results show that the markets interacted very significantly during the stress period. Platinum was the market that most influenced its peers (1 to 8 comovements), the MOEX, 1 to 7, MASI, 2 to 6, the Dow Jones went from 4 to 7 comovements, the Amman SE General and EGX 30 markets went from 1 to 4, the Israeli market (ISRAEL TA 125) and Silver went from 2 to 4 comovements, and finally the Gold Bullion LBM from 3 to 4. The study’s conclusions contain important information for investors, policymakers, and other participants in the financial energy markets. Acknowledgments The authors are grateful for the comments and suggestions from reviewers that helped improve the quality of the manuscript. Rui Dias is pleased to acknowledge the financial support from Instituto Superior de Gestão (ISG) [ISG - Business &amp; Economics School], CIGEST.
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Tsvetkov, Konstantin, Vladimir Slepov, Vladimir Sekerin, Anna Gorokhova e Evgeniy Skubriy. "Current State and Perspectives of Ferrous Metallurgy Development in Russia". International Journal of Engineering & Technology 7, n. 4.38 (3 dicembre 2018): 697. http://dx.doi.org/10.14419/ijet.v7i4.38.24757.
Abstract (sommario):
The current state of ferrous metals’ market is characterized by intensive development; the metallurgical production in several Asian countries has taken the leading position in the world; and metallurgy in the USA, Germany and Russia faces strong pressure from manufacturers of metals in Asian countries. The metallurgical complex in Russia is experiencing the period of its reconstruction: the time-consuming open-hearth steelmaking has been virtually deleted in the country, electrometallurgy is developing slowly, especially production of steel in induction furnaces, the amount of rejects in rolling is significant, and production of rolled products is still insufficient.The key changes in metallurgy are observed in rolling production. High quality finishing of metal allows to reduce the overall amount of rejects in metallurgical production, improve the interest of the market in the produced metal, and increase the export potential of the Russian metallurgy.The reduced production in the engineering industry after 1990 had the most negative impact on the development of Russian ferrous metallurgy. An important element that contributes to improving the economic efficiency through the activity of the metallurgical complex is more uniform placement of production across the country, particularly development of metallurgy in the Far East Federal District.
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Pinna, Eliana G., Norman Toro, Sandra Gallegos e Mario H. Rodriguez. "A Novel Recycling Route for Spent Li-Ion Batteries". Materials 15, n. 1 (22 dicembre 2021): 44. http://dx.doi.org/10.3390/ma15010044.
Abstract (sommario):
In this work, a recycling route for spent Li-ion batteries (LIBs) was developed. For this, the recovery of the metal content in both electrodes (anode and cathode) was investigated. Based on these results, an economic analysis of this recycling process was carried out. The obtained results showed that more than 90% of the material contained in both electrodes was recycled. The dissolution with acetic acid of the metals present in the active cathodic material is thermodynamically viable and the addition of a reducing agent such as hydrogen peroxide improved the spontaneity of the reaction. Dissolutions close to 100% for Li and Co were obtained. In addition, it was determined that the synthesis of lithium and cobalt valuable compounds was viable from the leach liquor, recovering approximately 90% of Co as cobalt oxalate, and 92% of Li as lithium carbonate. Furthermore, carbon graphite and Cu were fully recovered (100%) from the anodes. Finally, the results of the economic analysis showed that the recovered products have a high commercial value and industrial interest, providing an environmentally and economically viable process.
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McGrath, R. B., e G. C. Badcock. "New Dispersion Strengthened Platinum Alloy". Platinum Metals Review 31, n. 1 (1 gennaio 1987): 8–11. http://dx.doi.org/10.1595/003214087x311811.
Abstract (sommario):
Zirconia grain stabilised platinum alloys developed by Johnson Matthey are widely used to contain molten glass. The high temperature strength of these alloys is well in excess of that of similar conventional rhodium-platinum alloys, and zirconia grain stabilised ten per cent rhodium-platinum, the strongest alloy in the range, is used in the most demanding applications where its excellent creep resistance offers prolonged component life. However the present high cost of rhodium, compared with that of platinum, has generated increased interest in alloys with a lower rhodium content suitable for certain applications where the outstanding properties of the ten per cent alloy are not fully utilised. To meet this demand Johnson Matthey have now developed zirconia grain stabilised five per cent rhodium-platinum. This alloy offers a useful range of physical properties for applications where economic considerations are a major factor.
50
Marchetti, Patrizia, Fatmira Shehu, Angela Di Pinto, Valeriana Colao, Giuseppina Tantillo e Edmondo Ceci. "Heavy metals risk assessment in Salmo letnica from Lake Ohrid in Albania". Marine and Freshwater Research 70, n. 11 (2019): 1543. http://dx.doi.org/10.1071/mf18419.
Abstract (sommario):
The Ohrid trout (Salmo letnica) is an endemic species of trout found only in Lake Ohrid, in the Balkan republics of North Macedonia and Albania, where it is a species of significant economic and nutritional interest. Considering the importance of chemical risk assessment in fish for human consumption set out by European and international legislation and the risk of extinction of the Ohrid trout, the aim of the present study was to evaluate the safety of Ohrid trout flesh for human consumption by determining the heavy metal concentration in different organs through atomic absorption spectrometry (AAS). Heavy metal concentrations differed significantly in different organs (P<0.001). The mean and range of Pb and Cr concentrations in muscle were lower than the permissible limits recommended for human consumption according to the European Union (EU), as well as the Food and Agriculture Organization of the United Nations (FAO) and World Health Organization, whereas the mean concentration and range of Cd in muscle tissue were above the critical limits for human consumption set by the EU and FAO, revealing inspection-related problems. Accordingly, S. letnica is not completely safe for human consumption. Therefore, the long-term assessment of heavy metal concentrations in Ohrid trout from Lake Ohrid is an important safety measure for fish consumers and will help assess the status of exploitation of this biological resource.