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Summary Several studies have estimated the effects of various nonpharmaceutical interventions on the COVID-19 pandemic using a ‘reduced form’ approach. In this paper, I show that many different SIR models can generate virtually identical dynamics of the number of reported cases during the early stages of the epidemic and lead to the same reduced form estimates. In some of these models, policy interventions effectively reduce the transmission rate; in others, the growth of the reported number of cases slows down even though policy has little or no effect on the transmission rate. Thus, the effect of policy cannot be uniquely determined based on the reduced form estimates. This result holds regardless of whether time series or panel data is used in reduced form estimation. I also demonstrate that the reduced form estimates of the policy effect based on panel data specifications with two-way fixed effects can have the wrong sign.

Involvement of the population in physical training and sports determines the level of public health. The Russian government today has taken a firm course to involve Russians of all ages in physical culture and sports activities. However, the widespread introduction of physical culture and sports practices into the daily life of Russians requires a clear understanding of the motives and incentives of the population for systematical physical training and sports, as well as identification of the barriers to physical culture and sports activity. The article presents the results of a sociological study, the purpose of which was to identify the motives and incentives of the Russian population for systematic physical training and sports, as well as factors that hinder physical education. The analysis of the social situation in the field of physical culture and sports is based on the results of 16 focus groups conducted with various categories of population ranging from parents of children aged 3-5 to people over 60 living in various cities of Russia. It is shown that the vast majority of parents of children, adolescents, youth, people of middle and older ages have formed sufficiently stable attitudes for regular physical education. However, they are not always implemented due to a number of barriers. Among them are: high cost of sports sections, subscriptions to fitness and gyms, payment for a personal trainer; lack of specialized sports organizations, lack of necessary equipment in them; high engagement of the population in labor, educational and household activities; fears for the life and health of children, fear of great physical strain and chronic diseases; psychological barriers and stereotypes: adolescents experience embarrassment associated with the presence of unfamiliar spectators; middle-aged and older people are afraid of being judged by other people, they are afraid to look ridiculous. The results of the study can become the basis for development of measures to motivate the Russian population to systematic physical training and sports, as well as measures to overcome the barriers hindering physical culture and sports activity of Russians.

openaire: EC/H2020/721385/EU//SOCRATES The accomplishment of the goals set in the EU Green Deal and the Agenda 2030 for Sustainable Development requires a metallurgical industry that is even more resource-efficient, environmentally friendly and socially responsible than it is today. The European Training Network SOCRATES has taken this up by developing ground-breaking metallurgical processes for the valorisation of industrial intermediate products. This short article summarises the results obtained in the 4-year project and discusses the outcomes in light of the recently adopted EU Green Deal.

Funding Information: This research received funding from the European Union Framework Program for Research and Innovation Horizon 2020 under Grant Agreement No. 721385 (EU MSCA-ETN SOCRATES; project website: https://www.etn-socrates.eu ). The GoldTail (Grant No. 319691, ML) and NoWASTE (Grant No. 297962, KY) projects funded by the Academy of Finland are greatly acknowledged. The authors thank the laboratory personnel at VTT and Metso Outotec for their skillful technical assistance with the experimental work. Publisher Copyright: © 2021, The Author(s). Recently, an emerging electrodeposition-redox replacement (EDRR) method was demonstrated to provide exceptionally efficient gold recovery from cyanide-free hydrometallurgical solutions. However, the effect of electrode material and its corrosion resistance in this process was overlooked, even though the EDRR process is carried out in extremely corrosive, acidic chloride solution that also contains significant amounts of strong oxidants, i.e., cupric ions. In the current study, nickel alloy C-2000, stainless steels 316L and 654SMO, and grade 2 titanium were for the first time critically evaluated as potential cathode materials for EDRR. The particular emphasis was placed on better understanding of the effect of cathode substrate on the overall efficiency of the gold recovery process. The use of a multiple attribute decision-making method of material selection allowed reaching of a well-founded compromise between the corrosion properties of the electrodes and process efficiency of gold extraction. The 654SMO steel demonstrated outstanding performance among the examined materials, as it enabled gold recovery of 28.1 pct after 3000 EDRR cycles, while its corrosion rate (CR) was only 0.02 mm/year.

The project focuses on the interrelated dynamics between the employment sector and the educational system in the Russian Federation and across regions, identifies structural and regional features of such interconnection. It dwells upon the analysis, simulation and forecasting the process of coordinating the demand for talent and the supply of workforce with different levels of education in the national and regional labor markets. The authors provide insights into the factors and conditions that determine the peculiar interaction of demand for labor and its supply, taking into account the education of the workforce, including, across the regions. The research reviews the findings of simulating the process that coordinates the demand for talent and the supply of workforce with different levels of professional education. It shows the interaction of talent demand and supply with due regard to workforce education in individual regional labor markets.

This paper studies the SEIRD epidemic model for COVID-19. First, I show that the model is poorly identified from the observed number of deaths and confirmed cases. There are many sets of parameters that are observationally equivalent in the short run but lead to markedly different long run forecasts. Second, I show that the basic reproduction number R 0 can be identified from the data, conditional on epidemiologic parameters, and propose several nonlinear SUR approaches to estimate R 0 . I examine the performance of these methods using Monte Carlo studies and demonstrate that they yield fairly accurate estimates of R 0 . Next, I apply these methods to estimate R 0 for the US, California, and Japan, and document heterogeneity in the value of R 0 across regions. My estimation approach accounts for possible underreporting of the number of cases. I demonstrate that if one fails to take underreporting into account and estimates R 0 from the reported cases data, the resulting estimate of R 0 may be biased downward and the resulting forecasts may exaggerate the long run number of deaths. Finally, I discuss how auxiliary information from random tests can be used to calibrate the initial parameters of the model and narrow down the range of possible forecasts of the future number of deaths.

openaire: EC/H2020/721385/EU//SOCRATES The electrodeposition-redox replacement (EDRR) process is a promising method for a selective extraction of minor metals from complex mixtures. When it is performed in a benign medium (such as sodium chloride solution or deep eutectic solvent), the EDRR method provides a non-toxic alternative for a conventional cyanide-based process. The detailed reaction mechanisms of the EDRR in Cu–Au systems, as well as the effect of the reaction medium are elucidated in this article. Electrogravimetric studies show that the EDRR process comprises three distinct stages: (1) deposition of Cu at a constant applied potential; (2) dissolution of deposited Cu at open circuit conditions in reaction with dissolved species in solution; (3) reduction of Au to elemental form in reaction with various Cu species. It is discovered that the recovery of Au takes place surprisingly via both the redox replacement between Cu and Au at the surface and the homogeneous Au reduction by Cu(I) species in solution. Both of these reaction pathways are facilitated by open circuit conditions (redox replacement step) between electrodeposition cycles and the utilization of other sacrificial elements in the solution is crucial. The use of aqueous chloride solution is advantageous over 1 : 2 ChCl : EG for the increased Au recovery (94.4%) and the purity of the product (93.7%), although it consumes slightly more electricity. Therefore, the EDRR enables energy and resource efficient selective extraction of Au from multi-metal industrial solutions even when it is present at low concentrations.

The recovery of metals from industrial side-streams and process streams is typically performed by solvent extraction, cementation or precipitation, chemical reduction, or electrowinning. However, several industrial process, side- and waste streams do contain also trace amounts of valuable metals such as Ag and Au at lower than ppm scale, making the economics of the recovery challenging. Recently, we have introduced electrodeposition-redox replacement (EDRR) method as a route to extract Ag from Zn process streams [1], where a successful recovery of Ag was possible even from ppb concentrations. In EDRR method, the base metal (such as Zn) is first deposited during the electrodeposition step, followed by a redox replacement step in the absence of applied potential or current. During this latter step, the deposited less noble metal is spontaneously replaced by a more noble metal (such as Ag) still present in the solution. As a result, Ag is enriched on the electrode. This paper concentrates on the effect of impurities on the recovery of valuable metals (Ag and/or Au) from solutions typical for hydrometallurgical industry, such as chloride, sulfate and nitrate based solutions. The measurements were performed in simulated process solutions in which metal and impurity concentrations were close to actual solutions of sulfate based Zn process solution [1], Doré slag leaching [2], or cyanide free gold chloride leaching [3]. The morphology and quality of the recovered metal product was determined by SEM-EDS and the EDRR results showed a high selectivity towards Ag and Au in all investigated hydrometallurgical solutions despite of the impurities present in the solution. Moreover, the impurities investigated were shown to speed up EDRR reactions, regardless of the concentration of the impurity - ppb, ppm or even g/L scale. Acknowledgements Academy of Finland (NoWASTE - Project No: 297962), EU Framework Program for Research and Innovation Horizon 2020 (MSCA-ETN SOCRATES - Grant Agreement No: 721385) and Finnish Steel and Metal Producers (METSEK-project) are acknowledged for financial support. The research utilized “RawMatTERS Finland Infrastructure” (RAMI, funded by Academy of Finland) based at Aalto University. References: [1] P. Halli, H. Elomaa, B. P. Wilson, K. Yliniemi, M. Lundström, ACS Sustainable Chem. Eng. 5 (2017) 10996 - 11004. [2] P.Halli, S. Jolivet, A. Klöfverskjöld, P. Latostenmaa, B.P. Wilson, M. Lundström(2017) Leaching of Sb from TROF Furnace Doré Slag. In: Zhang L. et al. (eds) Energy Technology 2017. The Minerals, Metals & Materials Series. Springer, Cham. [3] M. Lampinen, S. Seisko, O. Forsström, A. Laari, J. Aromaa, M. Lundström, T. Koiranen, Hydrometallurgy 169 (2017) 103–111.

openaire: EC/H2020/721385/EU//SOCRATES The current paper introduces for the very first time recently invented electrodeposition-redox replacement (EDRR) method in continuous leaching-recovery-solution purification process. The mini-pilot study reveals that longer duration of the EDRR process is beneficial as it increases gold recovery per stage and decreases the specific energy consumption of the EDRR. This extraordinary behavior is postulated to be inherent to the EDRR process, as during the EDRR the cathode surface is gradually transformed from stainless steel surface to gold(±copper) surface, thus increasing process performance with time. In addition, gold concentration of 1 mg/L in the PLS was established as the minimum concentration required for efficient operation of the EDRR process. Gold extraction from ore to solution throughout the pilot test reached up to ca. 90%, whereas in reference cyanidation test only 64% of gold was dissolved. Overall, after 150 h of pilot experiment, 83% of dissolved gold was recovered from solution on the cathode, resulting in 68.5% holistic recovery of gold from ore. Furthermore, process simulation model was built, and it suggested that closed-loop operation of cupric chloride leaching – EDRR recovery – copper precipitation process can recover in total over 84% of gold from refractory telluride ore to the cathode product, providing further evidence of true potential of EDRR in sustainable gold extraction.

Gravity separation is considered as the most used processing technique for thermal coal cleaning. A broad variety of methods and machines was developed for that purpose. However, the performance of those apparatus under different conditions is not the same. In this article, the results of coarse thermal coal cleaning in various equipment were simulated by means of mathematical modelling. The comparison of obtained quantitative and qualitative indicators of gravity separation showed that for processing of difficult-to-wash thermal coal the heavy medium-based processes are more favorable, whereas for more easily washable coal jigging can be efficiently used as well.

This study documents some challenges with estimating the effect of various policy interventions on the COVID-19 pandemic It shows that the same dynamics of the

This paper studies the SEIRD epidemic model for COVID-19. First, I show that the model is poorly identified from the observed number of deaths and confirmed cases. There are many sets of parameters that are observationally equivalent in the short run but lead to markedly different long run forecasts. Second, I show that the basic reproduction number R0 can be identified from the data, conditional on epidemiologic parameters, and propose several nonlinear SUR approaches to estimate R0. I study the performance of these methods using Monte Carlo studies and demonstrate that they yield fairly accurate estimates of R0. Next, I apply these methods to estimate R0 for the US, California, and Japan, and document heterogeneity in the value of R0 across regions. My estimation approach accounts for possible underreporting of the number of cases. I demonstrate that if one fails to take underreporting into account and estimates R0 from the reported cases data, the resulting estimate of R0 may be biased downward and the resulting forecasts may exaggerate the long run number of deaths. Finally, I discuss how auxiliary information from random tests can be used to calibrate the initial parameters of the model and narrow down the range of possible forecasts of the future number of deaths.

This paper studies what the infection fatality rate (IFR) really measures using the potential outcomes framework. I show that the IFR only reflects the outcome in one state. In contrast, popular causal parameters are all functions of the difference between outcomes in two states. I then demonstrate using a simple illustrative example that a disease that has no effect of the risk of dying can have a higher IFR than a disease that increases the risk of dying for everyone in the population. As a result, the IFR may fail to reflect the causal effect of a disease on the risk of dying and hence might not be a suitable measure of how deadly the disease is.

Abstract The article proposes a solution of the task of achieving the target regional population size and structure, which would be sustainable in the long term, by means of managing its movement. The significance of this task is justified by the growing concentration of population and labour in a few number of Russia’s regions in the current and projected periods, primarily due to migration processes. The apparatus of matrix equations is used to shape the conditions for reaching the target size and structure of the population. The article presents the estimates of the equilibrium population of the Russian Federation and the possibilities of reaching the target population size in prospect. The demographic forecast of Rosstat up to 2035 in three variants is considered as a target. For each of variants, the required increase of population via birth and immigration is calculated. The possibilities to assess the need in population inflow and to achieve the target population size by using the methodology proposed in the article are shown by the case of the Far Eastern Federal District. It is argued that nowadays a crucial element of social and economic policy in the regions should be creation of new jobs with higher labour productivity and therefore, reduction of the need for foreign labour migrants in the Russian labour market.

The one-shot approach, DeepMark, for fast clothing detection as a modification of a multi-target network, CenterNet, is proposed in the paper. The state-of-the-art accuracy of 0.723 mAP for bounding box detection task and 0.532 mAP for landmark detection task on the DeepFashion2 Challenge dataset were achieved. The proposed architecture can be used effectively on the low-power devices., Published in ICCV 2019 Workshop

This paper develops a consistent series-based specification test for semiparametric panel data models with fixed effects. The test statistic resembles the Lagrange Multiplier (LM) test statistic in parametric models and is based on a quadratic form in the restricted model residuals. The use of series methods facilitates both estimation of the null model and computation of the test statistic. The asymptotic distribution of the test statistic is standard normal, so that appropriate critical values can easily be computed. The projection property of series estimators allows me to develop a degrees of freedom correction. This correction makes it possible to account for the estimation variance and obtain refined asymptotic results. It also substantially improves the finite sample performance of the test.

openaire: EC/H2020/721385/EU//SOCRATES Currently, the adsorption methods (e.g., CIP / CIL) are by far dominating the recovery of gold from leaching solutions, especially in cyanide media. However, gradual shift towards cyanide-free gold processes also requires new developments in the recovery technologies. High concentrations of base metal and impurities cause co-adsorption by activated carbon or ion exchange resins and consequently lower gold recovery. As an alternative solution, the electrodeposition-redox replacement (EDRR) method was recently demonstrated for recovery of gold from synthetic chloride solutions. In contrast to adsorption, EDRR does not require addition of chemicals in the process and is suitable for elemental gold recovery from chloride leaching solution. In this paper, cupric chloride solution from ore leaching was tested for applicability of the EDRR method. Obtained results demonstrate that gold can be recovered from industrial process solutions containing Au at ppm scale while the base metal (Cu) concentration was as high as30 g/L and other impurities (mainly Fe, also Zn, Co and Ni) present at various levels between ppm and g/L. The final gold deposit was analyzed with scanning electron microscopy, which confirmed the recovery of gold from the solution. Further optimization of the EDRR process parameters could make it a viable alternative to existing best available technologies due to simplicity of the process flowsheet, energy efficiency and ability for selective recovery of elemental gold even from very low concentrations.

This paper develops a consistent heteroskedasticity robust Lagrange Multiplier (LM) type specification test for semiparametric conditional mean models. Consistency is achieved by turning a conditional moment restriction into a growing number of unconditional moment restrictions using series methods. The proposed test statistic is straightforward to compute and is asymptotically standard normal under the null. Compared with the earlier literature on series-based specification tests in parametric models, I rely on the projection property of series estimators and derive a different normalization of the test statistic. Compared with the recent test in Gupta (2018), I use a different way of accounting for heteroskedasticity. I demonstrate using Monte Carlo studies that my test has superior finite sample performance compared with the existing tests. I apply the test to one of the semiparametric gasoline demand specifications from Yatchew and No (2001) and find no evidence against it.

Despite of being the most common hydrometallurgical process for extraction of gold from ores and concentrates, cyanide leaching is blamed for its hazardous impact on environment and human health. These concerns have given a rise for alternative cyanide-free technologies, such as cupric chloride leaching. However, the state-of-art processes for gold recovery from chloride solutions are facing issues of high reagent consumption and poor selectivity. This article describes an innovative method for recovery of minor concentrations of gold from hydrometallurgical solutions by repetitive Electrochemical Deposition-Redox Replacement (EDRR) cycles. In contrast to conventional carbon-in-leach/resin-in-leach technologies or solvent extraction, the proposed electrochemical method does not require addition of any chemicals in the process and remarkably selective gold recovery can be achieved from concentrated cupric solution by tailoring the process parameters. A number of electrochemical experiments was performed in order to identify the process variables affecting the Au recovery. Results indicate that so called cut-off potential and deposition time were the EDRR parameters having the strongest impact on gold recovery at fixed concentration of Cu and Au ions. The Au content in the metal deposit after 250 EDRR cycles exceeded 75% and the Au:Cu ratio has increased by a factor of 1000, from 1:340 in the solution up to 3.3:1 in the final product. X-ray photoelectron spectroscopy analysis of the cathode surface confirmed full replacement of sacrificial copper with gold. Obtained results prove that the EDRR method can be efficiently used for the recovery of trace amounts of gold from cupric chloride solutions used for cyanide-free gold leaching.

The present level of economy sets more and more stringent requirements for product quality, equipment and technologies used in the coal preparation industry. In this regard, methods of process optimization and efficiency improvement, based on the information technologies, become of current interest at existing facilities as well as in designing of new ones. Mathematical models of preparation processes are of particular relevance in the design and operation of concentrators, because they allow exploring various options for process flowsheets and determining optimal process parameters. The choice of process parameters is based on analytic representation of washability curves using numerical analysis. The results of float-and-sink testing, presented in graphical form as washability curves, allow making a theoretical balance of coal processing products and establishing an optimal separation density to reach the maximum production of clean coal. Usually, their plotting is conducted manually on graph paper, which is a very time-consuming and laborious procedure. This issue is arising, from time to time, in publications of authors all around the world, but there is still no commonly accepted procedure designed. In the present article authors made an attempt to examine different existing methods for analytical representation of coal washability curves suitable for the application in computer simulation of gravity concentration processes. During the work on this topic, a software complex has been developed. Description of the developed software and an example of its use for the purpose of flowsheet selection for the coal preparation unit is provided.

The article examines a wide range of problems related to Russia’s joining the WTO. An assessment of the present stage of negotiation process on Russia’s accession to the WTO is given. Based on the analysis of Russian methodological and methodical approaches to assessing the balance of «benefits» and «losses», opportunities have been outlined for spatial distribution of the effects of Russia’s accession to the WTO

OSDR techniques for spatial characterization of fiber Bragg gratings based on local phase induction by IR or UV radiation have been developed. Both radiation types provide longitudinally and cross-sectionally uniform fiber excitation, high spatial resolution and good sensitivity of measurements.

It is becoming ever more clear that the natural resources – especially metals – are gradually being depleted from the Earth’s crust. Therefore, secondary sources such as industrial residues, waste ...

openaire: EC/H2020/721385/EU//SOCRATES The object of the current study was to compare the extraction yields of various valuable metals from process residues by ferric and cupric chloride leaching as an alternative to cyanidation. Flotation tailings, with low amount of gold, copper, nickel, cobalt and zinc were used as a raw material. In the chloride leaching experiments, the effect of the oxidant type and concentration ([Fe3+] and [Cu2+] from 10 to 50 g/L), was investigated on the metals extraction. At the same time, pH (1 and 1.8), temperature (95 °C), solid/liquid ratio (25 %), oxygen feed rate (1200 mL/min), leaching time (24 h), and stirring rate (950 rpm) were kept constant. Additionally, the reference leaching experiment with sodium cyanide (NaCN) at 22 °C, pH = 11, solid/liquid ratio of 25 %, air feed rate 500 ml/min, stirring rate 400 rpm and 24 hours of leaching time was run to benchmark leaching efficiencies of cyanide-free processes. The results showed that the maximum gold extraction was observed with cyanidation (78 %) and followed byferric and cupric chloride leaching. For copper, the extractions were higher in chloride leaching (75 – 100 %) whereas cyanide could dissolve 50 % of copper. Extraction of nickel and zinc were slightly higher in ferric chloride leaching compared to cupric chloride leaching, but cobalt extraction was similar in both chloride leaching methods. However, extraction of these metals was insignificant in cyanide leaching. With these results, it seems that chloride leaching with the presence of cupric and ferric oxidants can be used as an alternative cyanide-free method for extraction of metals from process residues.