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Considers three common cases of localized corrosion of metals: pitting, crevice, and stress corrosion. Provides experimental methods for studying all three methods. Includes a discussion of expected results. (ML)

This article, intended for secondary school chemistry students, discusses the corrosion of metals. The discussion includes: (1) thermodynamic aspects of corrosion; (2) electrochemical aspects of corrosion; and (3) inhibition of corrosion processes. (HM)

The uses of sulfuric acid in our technological society are given. The discussion includes sulfuric acid in the petroleum industry, construction industry, textile industry and in steel production. (SA)

Each year, approximately million tons of waste is generated from eggshells disposed of in landfills. This waste is challenging to manage because of the odor and microbiological development. However, eggshells have potential applications as a solid byproduct. They can be modified and used in various industries such as metal, polymer and ceramic composites, in the production of biodiesel, heavy metal absorption from wastewater, and even as a biomaterial to substitute bone tissues. Furthermore, eggshells can be used as a cheap adsorbent for the treatment of contaminated waterways. They are also a great source of calcium and fertilizer for plants, animals and humans. Chicken eggshells can even be used as a catalyst for converting waste frying oil into biofuel. This review highlights the challenges and opportunities of eggshell waste valorization in the food industry. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Friction Stir Processing (FSP) has become a famous solid‐state technology for the fabrication of a wide range of aluminum alloy‐based composites that today find multiple applications across the various metal industries. Generation of revolving, ribbon, bulk, excessive or mass flash as it is generally termed has been a common problem in numerous FSP works. When confronted by this challenge, many researchers apply different experimental and numerical modeling approaches or strategies to reduce the mass flash to practically acceptable limits since it often leads to undesirable loss of material and is also an unwanted defect. This subject is deficiently reviewed, and it therefore becomes the thrust of this paper, to investigate the common trends in mass flash generation during FSP and its commonly employed reduction strategies. Mass flash is caused by high rotational speed at low travel speed and vice versa, flat shoulder, no and low tilt angles, high plunge depth, axial force, and travel force. Mass flash causes material loss, loss of volume fraction control target, material thinning, and leads to poor quality fabrications. Mass flash reduction strategies include the use of high tool tilt angles, concaved tool shoulder, proportional rotational speed and travel speed, and optimal plunge depth, axial force and travel speed as supported by both the experimental and numerical modeling studies. [ABSTRACT FROM AUTHOR]

Humans have considerably influenced accumulation rates and sediment composition in lake deposits. Due to near‐continuous accumulation, lakes and reservoirs are an excellent archive of these anthropogenic influences. The Urft Reservoir in the Eifel Mountains, western Germany, provides a unique record of the human influence on the landscape for the past 115 years. In 2020 and 2021, 24 cores and 23 surface samples were obtained from the bottom of the, by that time drained, reservoir. Grain size, heavy metals, weathering signatures and microplastic were analysed. For the chronology, caesium‐137 and microplastic were used. Using the first occurrence of microplastic as well as different plastic types for dating was not successful. However, a distinct layer with a high number of microplastic particles could be traced back to a fire in 1991 and was used as an additional stratigraphic marker in the age‐depth model. A period of relatively high accumulation rates in the reservoir occurred in the mid‐1950s and was related to enhanced construction works in the local valleys. Analysis of heavy metal content in the reservoir sediments shows a strong connection to historical changes in ore industry in the valley of the Urft. Stricter environmental protection laws and the decline of the metal processing industry resulted in a reduced input of lead, copper and zinc in the reservoir until the mid‐1980s. Since then, heavy metal content has remained relatively constant. A major flooding event in July 2021 did not lead to the remobilisation of older contaminated deposits as indicated by low heavy metal content in flood deposits. Accordingly, also the microplastic content is not increasing following the extreme event. Due to the degree of weathering of the flood deposits, it is argued that mainly hillslope material was transported into the Urft and subsequently into the Urft Reservoir during this event. [ABSTRACT FROM AUTHOR]

Introduction: We assessed the impact on metal levels of seafood, mollusk and fish consumption (SMFc) before urine and toenail sample donation among workers exposed to metals. Methods: This is a cross-sectional epidemiological study with 101 workers from the chemical and metal industry and 40 unexposed workers from the services sector. We measured urinary (As, Ba, Be, Cd, Co, Cu, Hg, Li, Mo, Pb, Se, Sr, Tl, V, W and Zn) and toenail (same plus Al, Cr, Fe, Mn, Ni and U) metal levels. Results: Urinary arsenic levels were higher among workers eating seafood or mollusks (102 ppm vs. 55.4 ppm; p = 0.042) or fish (109 ppm vs. 48 ppm; p = 0.007) 8 h before sample donation. Urinary mercury was associated with consumption of blue fish (11.865 ppm) and canned sardines (19.125 ppm) (p = 0.028). With respect to toenails, fish consumption was associated with aluminum (17 ppm vs. 8.6 ppm; p = 0.012) and beryllium (5 ppb vs. 1 ppb; p = 0.017). Arsenic urinary levels were associated with numbers of hours prior to sample collection since latest SMFc (p = 0.001). Conclusion: Among workers exposed to metals, seafood, mollusk and fish consumption is an important determinant of urinary arsenic levels, as sea fish for urinary mercury, but not for other metals. [ABSTRACT FROM AUTHOR]

Molten aluminum is among the most common causes of burns in the metal industry. However, only few reports are available on molten aluminum injuries. Herein, we report an unusual case of molten aluminum burn. The patient had burns not only on the body surface but also in the respiratory tract and esophagus, adding to the difficulty of treatment. Multidisciplinary consultation and cooperation led to the development of a treatment plan for the patient, which included tracheotomy, respiratory management, endoscopic therapy, infection control, and psychological support. To our knowledge, this is the first report of molten aluminum-induced burns involving the face, neck, respiratory tract, esophagus, and eyes. We also describe our experience with multidisciplinary treatment for the management of molten aluminum burns. [ABSTRACT FROM AUTHOR]

Copyright of Industrial Minerals & Processing / Huagong Kuangwu yu Jiagong is the property of Industrial Minerals & Processing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Cleanup of oil spills has become one of the most challenging tasks in recent years, as marine oil spills have had a great negative impact on human health and the ecological environment. This also urgently requires the development of new materials and methods with superhydrophobic properties for oil-water separation. As new porous materials, metal-organic frameworks (MOFs) have attracted much attention due to their unique structures and fascinating properties. However, powdered MOF materials are difficult to recycle, and therefore, suitable substrates need to be selected to construct superhydrophobic composites. The surface hydroxyl groups of cellulose fibers offer great possibilities for their superhydrophobic preparation. In this paper, HDTMS-UiO-66@CFs composites with superhydrophobicity were strategically synthesized by in-situ growth of Zr(IV)-based MOFs linked to hexadecyltrimethoxysilane (HDTMS) on cellulosic fibers (cotton fabric) by using a hydrothermal synthesis method. The HDTMS-UiO-66@CFs composites have a water contact angle of 172[degrees] and the absorption capacity of light oil and heavy oil is more than 1100%, and the oilwater separation efficiency is as high as 96%. Due to the in-situ growth of the HDTMS-UiO-66 material on cotton fibers, which makes the material more resistant and stable, the material can still maintain its superhydrophobic properties in various harsh environments and after repeated use. Therefore, the newly developed HDTMS-UiO-66@CFs composites have a high potential as novel adsorbent materials for cleaning up offshore oil spills and other applications. Highlights * In-situ growth of superhydrophobic metal-organic frameworks (MOF) particles on cellulose fibers. * The porous structure of hexadecyltrimethoxysilane (HDTMS)-Ui066 plays a key role in hydrophobicity. * HDTMS-Ui066@CFs are chemically stable and have long-term durability. KEYWORDS cotton fabrics, hydrophobicity, oil-water separation, zirconium-based metal-organic framework, 1 | INTRODUCTION Marine oil pollution is immensely harmful. Its damage to biodiversity, aquatic ecosystems, coastal and marine ecosystems is serious and ongoing. (1) At the same time, oil pollution [...]

We examine the hedging and safe-haven characteristics of gold, silver, platinum, and palladium and three major indices in the US market. The metal markets are known for their hedging characteristics during financial distress. This article sheds new insights using high-frequency data into precious metals' hedging and safe-haven abilities under extreme market volatility conditions attributed to the COVID-19 crisis using the copula method. The results show that gold outperforms all other precious metals in hedging and as a safe haven under extreme stock market conditions, in both the pre-crisis and crisis periods, with silver as the next best alternative. JEL codes: G01, G11, G15, G19 [ABSTRACT FROM AUTHOR]

AbstractThis research evaluates the liability of foreignness (LOF) in metals and mining companies in Brazil by comparing the financial performance of foreign and local firms. The study also tests if the increase in the psychic distance index (PDI) reduces the performance of foreign companies. We estimated panel data regression models for a sample of 78 companies (29 multinationals in Brazil). Even though the performance differences between mining foreign companies and local ones are not significant, there is evidence that foreign firms face LOF and we confirmed a negative relationship between PDI and the performance of foreign metals and mining companies. [ABSTRACT FROM AUTHOR]

• Robot adoption led to a 10 % increase in productivity within China's manufacturing firms. • The impact was more pronounced in the first two years following adoption. • The impact was likely to be greater for small-size firms. • Multi-functional robots had more pronounced effects than single-functional ones. • Industry-city robot exposure had positive spillover effects on non-adopting firms. This study investigates the effect of industrial robots on firm productivity in China. Employing propensity score matching (PSM) and staggered difference-in-difference (SDID) estimations, we find a statistically significant and positive casual effect of robot adoption on firm productivity at the 1 % significance level, leading to an approximate 10 % increase in total factor productivity (TFP) among manufacturing firms in China. The effect was most pronounced in the first two years following adoption but lost statistical significance from the third year onward. Additionally, we find that robot exposure, measured by both adoption rate and adoption intensity, had positive and statistically significant spillover effects on large-scale non-adopting firms within the same industry and city, leading to significant improvements in their TFP. Furthermore, the effect of robot adoption on firm productivity varied by robot type, firm size, and industry. Multi-functional robots (MFRs) exhibited a more substantial effect compared to singlefunctional robots (SFRs). The automotive, plastic/chemical, and metal industries had great productivity gains compared to other industries. These results withstand various rigorous robustness checks, reaffirming the validity and consistency of our findings. [ABSTRACT FROM AUTHOR]

Chemical and lead isotope analyses aided by metallographic examination of copper axes found at the Late Neolithic settlement of Kietrz in southwestern Poland provide new evidence for the origin of copper and metal trade routes in the region. Our results indicate that metal used for the axes could be sourced from copper mines in modern Slovakia, Bulgaria and perhaps Serbia. The evidence from this study confirms that the Funnel Beaker people from Poland became parties to a metal trading network that connected much of continental Europe in the mid‐4th millennium bce and provides a better understanding of how these contacts provided the background for the technological and socio‐economic developments of the Baden era. [ABSTRACT FROM AUTHOR]

By coordinating the rolling direction and mode, a multi-rolling plastic deformation process for an aluminum (Al) sputter target is proposed to achieve multiple excellent properties, including a uniform and fine grain structure and low defect risk, which are significant in producing high-quality sputtered films. In this work, therefore, DEFORM 3D 10.2 software is adopted to establish three strategies, clock-synchronous rolling, cross-synchronous rolling, and clock–snake rolling. The effect of different rolling routes and modes on the metal flow velocity (MFV), effective strain distribution (ESD), grain size distribution (GSD), damage, and rolling force (RF) are comparatively investigated. The simulation results show that clock–snake rolling can increase the MFV and effective strain by producing a deeper deformation than the others. It provides sufficient energy for dynamic recrystallization to promote grain refinement. In combination with the microstructure homogeneity promoted by the clock rolling route, the GSD from 6.5 to 44.3 μm accounts for about 80.5% of all the grains because of the fact that a randomly oriented grain region is full of high-angle grain boundaries. Compared with the synchronous rolling mode, the decrement in RF maximum reaches up to 51% during the asynchronous rolling process because component energy is consumed to form cross-sheering stress. It remarkably reduces the risk of defects, with a damage value of less than 73%, and simultaneously improves energy efficiency owing to smaller and uniform grains caused by less RF. The results obtained in this work are of great significance as they can guide practical production in the metal target industry. [ABSTRACT FROM AUTHOR]

The current market is highly competitive, and customers are increasingly demanding. In this context, organizations need to adopt tools that enhance process efficiency to ensure competitiveness. This report aims to implement Lean tools, specifically Value Stream Mapping (VSM) and complementary tools, to optimize the production process in the metal treatment industry. A case study was conducted, beginning with a brief sector and process recognition, followed by an analysis of production stages using VSM. Value-added activities, non-value-added activities, and waste were identified. The current VSM revealed a Lead Time (LT) of approximately 336 h (14 days), value-added activities (VA) of 21 h, and a process cycle efficiency (PCE) of 6.29%. Improvement actions were proposed to reduce waste and increase competitiveness. After implementation, the LT decreased to approximately 318 h (13 days), VA increased to 23 h, and process efficiency improved to 7.15%. Despite the limitations of VSM in discontinuous flows, its use increased process efficiency, demonstrating its applicability in complex industrial contexts. [ABSTRACT FROM AUTHOR]

Cobalt, recognized as one of the scarcest industrial metals, is typically discarded during the zinc production process in the high-temperature refining section, along with manganese. This waste product is colloquially referred to as ‘hot cake.’ The present study endeavored to segregate cobalt and manganese from the hot cake and transition them into the liquid phase via bioleaching, a method that is both economically and environmentally superior to pyrometallurgical techniques. In the hot cake, cobalt exists as Co (III) and manganese as Mn (IV). Given their oxidized states, both cobalt and manganese are insoluble in acid and necessitate reduction for dissolution. The study employed Acidithiobacillus thiooxidans and Acidithiobacillus ferrooxidans bacteria to create an environment conducive to the reduction of cobalt and manganese. Under optimal conditions, this biotechnological approach facilitated the recovery of 62.8% of cobalt and 91.6% of manganese. Subsequently, a model was developed to predict the optimal method for processing cobalt from hot cake, based on the recovery rates of cobalt and manganese. This research contributes to the broader goal of resource recovery and waste minimization in the metal industry. [ABSTRACT FROM AUTHOR]

Storage systems and warehouse processing in factories are integral to manufacturing operations and logistics procedures. Proper factory layout, storage locations, and procedures save time and reduce cost and wastes. This study examines a real case scenario of a metal industry and sheet metal factory manufacturing commercial easy-to-install metal racks. We collected data, investigated the current situation of the factory, and specified the difficulties and problems regarding the procedures, storage system, and distribution of machines. Furthermore, several proposed solutions were presented and analyzed using simulation, followed by the selection of the best solution. Then, we applied 5S methodology to improve productivity and reduce waste. The findings reveal that reducing waste and time, enhancing productivity, and better space utilization can be achieved significantly. Moreover, this study indicates the feasibility of the proposed solutions, which can be adopted by similar factories and other industries. [ABSTRACT FROM AUTHOR]

Copyright of Carta Económica Regional is the property of Universidad de Guadalajara and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Industrial activities generate enormous quantities of polluted effluents, necessitating advanced methods of wastewater treatment to prevent potential environmental threats. Thus, the design of a novel photocatalytic reactor for industrial water decontamination, purification, and reuse is proposed as an efficient advanced oxidation technology. In this work, the development of the active reactor components is described, utilizing a two-step sol–gel technique to prepare a silica-titania trilayer coating on 3D-printed polymeric filters. The initial dip-coated SiO2 insulator further protects and enhances the stability of the polymer matrix, and the subsequent TiO2 layers endow the composite architecture with photocatalytic functionality. The structural and morphological characteristics of the modified photocatalytic filters are extensively investigated, and their performance is assessed by studying the photocatalytic degradation of the Triton X-100, a common and standard chemical surfactant, presented in the contaminated wastewater of the steel metal industry. The promising outcomes of the innovative versatile reactor pave the way for developing scalable, cost-effective reactors for efficient water treatment technologies. [ABSTRACT FROM AUTHOR]

Copyright of China Mining Magazine is the property of China Mining Magazine Co., Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Przegląd Elektrotechniczny is the property of Przeglad Elektrotechniczny and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This commentary is a descriptive analysis of available data on global inventories of non-ferrous metals, with particular attention to stocks held in the registered warehouses of the London Metal Exchange (LME). Long-term trends in reported global stocks of copper, lead and zinc are first illustrated, subdivided by the main categories of holder. The commentary then moves to trends in LME stocks of those three metals plus aluminium, nickel and tin, bringing out their sharp fluctuations over the course of the business cycle. With the rise in China's dominance of the metals industry, the LME has lost its share of these volatile stocks. The next section shows how the locations and origins of LME stocks have altered over time in response to changes in patterns of global production and usage. As markets of last resort, the LME, along with the other terminal market exchanges, experiences large inflows of metal into warehouses when global production exceeds demand and corresponding outflows in the reverse circumstances. Within the restrictions of the available data, the commentary shows how changes in stocks held by the LME and other exchanges have moved compared with estimated global balances between production and usage. Changes in exchange inventories and market balances have tended to move in the same direction and very roughly the same extent. That correspondence tended to weaken for some metals in the past decade during which changes in market balances were far more volatile than changes in exchange stocks. There were, seemingly, big changes in unreported stocks. The size of such pools of metal is, by its very nature, indeterminate, but the next section examines some data on off-warrant stocks held in LME registered warehouses. Even where the level of exchange inventories appears constant, there are continuous flows into and out of warehouses. That is highlighted by data on gross and net flows for LME warehouses. Part of the gross movements arises from metal owners moving metal onto and off warrant, often to take advantage of differences in rents. The level of exchange stocks is a function of the balance between global production and consumption, rather than of the level of either. This inevitably means that the ratio between exchange stocks and turnover, whilst highly cyclical, will tend to fall over time. Periods of low stocks can potentially complicate management the LME's role in determining prices. The final section looks at the relationship between LME inventories and turnover. [ABSTRACT FROM AUTHOR]

Climate change and its damaging consequences for ecology and humanity is advancing. Industry and its metals sector are responsible for most greenhouse gas emissions. Current costs of industrial goods do not reflect the true costs caused by the externalized climate damages of its production and thus offer no competitive incentive to decarbonize. Additionally, regional climate regulation can lead to competitive distortion. We therefore aim to investigate the impact of climate cost internalization on the metals industry. Using true‐cost analysis for an exemplary and widely used metal product, the effects of climate true costs depending on production region, technology, and energy mix, CO2e taxation and value chain are examined. Based hereon, the impact of internalizing climate true costs together with the introduction of a carbon‐border tax on the carbon leakage problem, climate protection, and the cost situation for companies in global competition are investigated. The results of the study show that steel and wire production is responsible for most CO2e emissions showing significant decarbonization effects by steel recycling whereas production location and logistics play a minor role. On a competitive level, cost internalization has hardly any effect on the product costs because of the currently low CO2e‐taxation rates. Thus, almost no incentive to produce or consume in a climate‐protective way is generated, incentivizing production in pollution havens versus highly climate regulated regions. Instead, to realize emission efficiency gains and innovations leading to a competitive advantage of decarbonized products and value chains, a significant increase of CO2e‐taxation rates together with a carbon‐border tax is necessary. [ABSTRACT FROM AUTHOR]

Purpose: India is not geographically close to either Russia or Ukraine. However, India's trade relations with them make it vulnerable to the consequences of the war between these countries. Thus, the present study aims to examine the impact of the Russia–Ukraine war on various sectoral indices of the Indian economy. Design/methodology/approach: Event study methodology has been used in this study for analysis. The date of the war announcement is the event day. The sample studied includes ten sectors of the Indian economy listed on the National Stock Exchange (NSE). Results correspond to the period of −167 days to +20 days of the announcement of the war, i.e. from June 25, 2021, to March 28, 2022. Findings: Almost all the sample sectors earned significantly positive abnormal returns in the post-event period. The metal industry has led this group by showcasing the highest abnormal returns. Though Indian sectors made overall positive returns, the market soon corrected itself and abnormal returns were wiped out. Practical implications: These results can benefit portfolio managers, analysts, investors and policymakers in hedging risks and selecting suitable investments during increased global uncertainty. The study's conclusions help policymakers establish an institutional and supervisory framework that will make it easier to spot systematic risks and reduce them by putting countercyclical measures in place. Originality/value: India has no geographical proximity or trade relations with Russia or Ukraine, as strong as any other European country. However, Russia has remained a strong ally to India in the trade of defense equipment. Similar is the case with Ukraine, a significant global partner for India. Thus, the impact of conflict between these two countries has not been limited to Europe only but has also engulfed related economies. Hence, the present study is one of the first attempts to examine the burns sustained by the Indian economy due to this war. [ABSTRACT FROM AUTHOR]

Flat-rolled steel sheets are one of the major products of the metal industry. Strip steel's production quality is crucial for the economic and safety aspects of humanity. Addressing the challenges of identifying the surface defects of strip steel in real production environments and low detection efficiency, this study presents an approach for strip defect detection based on YOLOv5s, termed SDD-YOLO. Initially, this study designs the Convolution-GhostNet Hybrid module (CGH) and Multi-Convolution Feature Fusion block (MCFF), effectively reducing computational complexity and enhancing feature extraction efficiency. Subsequently, CARAFE is employed to replace bilinear interpolation upsampling to improve image feature utilization; finally, the Bidirectional Feature Pyramid Network (BiFPN) is introduced to enhance the model's adaptability to targets of different scales. Experimental results demonstrate that, compared to the baseline YOLOv5s, this method achieves a 6.3% increase in mAP50, reaching 76.1% on the Northeastern University Surface Defect Database for Detection (NEU-DET), with parameters and FLOPs of only 3.4MB and 6.4G, respectively, and FPS reaching 121, effectively identifying six types of defects such as Crazing and Inclusion. Furthermore, under the conditions of strong exposure, insufficient brightness, and the addition of Gaussian noise, the model's mAP50 still exceeds 70%, demonstrating the model's strong robustness. In conclusion, the proposed SDD-YOLO in this study features high accuracy, efficiency, and lightweight characteristics, making it applicable in actual production to enhance strip steel production quality and efficiency. [ABSTRACT FROM AUTHOR]

The archaeological evidence from the Nanhai No.1 shipwreck provides tangible evidence for the study of maritime trade during the Song Dynasty, revealing the presence of a significant amount of smuggled metal in the cargo, suggesting possible involvement in smuggling activities. Merchants may have used tactics such as under-reporting and clandestine transportation of prohibited items to evade supervision, thus engaging in the illicit trade of metal materials and artifacts banned by the Song government on the international market. Valuations of the goods recovered from Nanhai No.1 indicate that the value of iron and silver exceeds that of porcelain, while the value of gold objects and currency exceeds that of porcelain by one-third. Research also suggests a possible shift in the model of maritime trade during the Song Dynasty, from government-led to merchant-led, with a gradual weakening of government supervision and control over trade. This change may be related to reforms in trade organization and the government leniency toward prohibited activities. Despite repeated government bans, smuggling of metal goods continued throughout the Song Dynasty, with no significant reduction in the scale of the metal trade due to the profit-seeking behavior of private merchants, highlighting the inadequacy of government control over illegal smuggling activities. This complex interplay between economic gain, national security, private interests and government control had profound implications for China, the broader South China Sea region and beyond, while the outflow of metal artifacts also facilitated the exchange of goods, technology and culture between China and the aforementioned regions. [ABSTRACT FROM AUTHOR]

Motivation: Improving the energy efficiency of enterprises is now not only a postulate of inter-national and national energy transition strategies towards climate neutrality, but also a requirement for maintaining their profitability and competitive capacity. Rising energy fuel prices and the unstable geopolitical situation, and above all, the war in Ukraine, are causing many enterprises to take energy-saving actions (ESA’s). One of them is investing in renewable energy sources (RES) for their own consumption, understood as investing in future energy purchase savings. Aim: The article aims to identify the involvement of enterprises affiliated with the Metal Processing Cluster (MPC), which has the status of the Polish Key National Cluster, in RES investments in the context of the energy crisis. It also attempts to verify the hypothesis: greater interest in investing in RES is shown by enterprises that have seen a strong negative impact of energy price increases on their operations. The research was carried out on the basis of literature studies, analysis of Polish Central Statistical Office statistical data and analysis of reports of various institutions. Empirical verification of the hypothesis was possible on the basis of the results of surveys conducted in the enterprises of the MPC. Results: The research showed that in 2022, more than half of the surveyed companies affiliated with the MPC felt the negative (very strong and strong) effect of rising energy prices. It primarily had an impact on the decline in their profitability. In 73% of the surveyed companies, this situation influenced the decision to start investments in renewable energy sources, with the majority of these investments being in photovoltaic panels. The survey contributes to the knowledge of the impact of the energy crisis on RES investments in metal companies. [ABSTRACT FROM AUTHOR]

Classic inventory theory suggests that inventory plays a vital role in matching demand and supply. This paper provides both country- and firm-level evidence that inventory can be used as a financial instrument to take advantage of arbitrage opportunities in financial markets with limited capital mobility. Using data from China customs' metal imports and firm-level inventory from metal processing industries, we show that firms can utilize the inventory of an imported product to carry lower cost capital into a country with strict capital controls and, thus, gain higher financial returns. Specifically, at the country level, we find that the level of imported metal commodities is positively associated with the expected returns from financial arbitrage. At the firm level, we find that a higher expected return from financial arbitrage will incentivize a firm to increase its inventory level through short-term borrowing. In addition, our evidence supports the notion that firms with higher liquidation value, larger size, and higher sales growth (i.e., firms with higher borrowing capacity) may be more active in using inventory as an instrument to seek higher financial gains. We also utilize a unique regulatory policy shock as a quasi-natural experiment to enhance the causality interpretation of our empirical findings. This paper was accepted by Vishal Gaur, operations management. Funding: This work was supported in part by the National Natural Science Foundation of China [Grant 72201230] and the Research Grants Council of Hong Kong, University Grants Committee [Grant 14504621]. Supplemental Material: The online appendix and data are available at https://doi.org/10.1287/mnsc.2023.4873. [ABSTRACT FROM AUTHOR]