Articoli di riviste: "Chromium research"

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Martynenko, V. V., P. O. Kushchenko, I. G. Shulyk, Yu Ye Mishnyova, K. I. Kushchenko e Yu O. Krakhmal. "Properties dependence of chromia and alumina-chromia-zirconia-silica refractories with a mass fraction of 30 % Cr2O3 on the type of chromium oxide". Scientific research on refractories and technical ceramics 121 (30 dicembre 2021): 23–35. http://dx.doi.org/10.35857/2663-3566.121.03.

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In JSC “URIR named after A. S. Berezhnoy” chromia refractories for the lining of pool and feeder of glass-making furnaces for the production of glass fiber from E glass, which are in contact with the glass melt, and alumina-chromia-zirconia-silica refractories with 30 % Cr2O3 for service in the topsides of these furnaces, in areas affected by components of the glass batch and glass melt, have been developed and manufactured. The main raw material for the chromia products manufacturing is metallurgical chromium oxide. In the manufacture of alumina-chromia-zirconia-silica products, metallurgical chromium oxide or a mixture of metallurgical and pigment chromium oxide in a ratio of 2 : 1 is used as the chromium oxide component of the batch. The testing of new materials, such as a new grade of chromium oxide, in the technologies of chromia and alumina-chromia-zirconia-silica refractories is relevant. The effect of a new grade of chromium oxide on the properties of chromia refractories has been investigated. It was found that samples of a new grade of chromium oxide, pressed at optimal values of moisture content of the mass and specific pressing pressure, are characterized by a low apparent density of the raw material in comparison with samples made of metallurgical chromium oxide. After firing, samples from chromium oxide of the new grade are not inferior to those of metallurgical chromium oxide in terms of properties, but they have large changes in linear dimensions during firing, which can lead to the formation of cracks, therefore, the issue of obtaining chromia products from mixtures with the replacement of metallurgical chromium oxide with chromium oxide of the new grade in order to increase the apparent density of products requires additional research. A study on the effect of new grade of chromium oxide on the properties of alumina-chromia-zirconia-silica refractories with a content of 30 % Cr2O3 has been carried out. It was established that, in the batch for the manufacture of these refractories, containing metallurgical and pigment chromium oxide, it is possible to completely replace the pigment chromium oxide with chromium oxide of the new grade or to increase the content in the batch of chromium oxide of the new grade instead of a part of metallurgical chromium oxide to the ratio of metallurgical chromium oxide and chromium oxide of the new grade 1 : 2.

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SHIRYAEV, Pavel Borisovich, e Nadezhda Vladimirovna VAKHRUSHEVA. "Genesis of podiform chromitites – a review of models". NEWS of the Ural State Mining University 1, n. 2 (15 giugno 2020): 20–29. http://dx.doi.org/10.21440/2307-2091-2020-2-20-29.

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Relevance of the work. Research aimed at identification of genesis of chromium ores in alpine-type hyperbasites has been conducted by scientists (geologists, petrologists and geochemists) around the world for more than a century. Nevertheless, the issue of their origin remains debatable to this day. The purpose of the work is to highlight the main stages of the development of scientific ideas about the genesis of chromian mineralization in alpinotype hyperbasites; to present and summarize the main, most significant and innovative scientific ideas of Russian and foreign experts who have been involved in this issue. Results. The evolution of scientific views on the genesis of chromic mineralization from the second half of the 19th century is traced. In Russia and abroad, its main stages are highlighted. Throughout this period, some ideas dominated that link the formation of concentrations of ore-forming chrome-spinels with its crystallization from magmatic melt. Major discoveries in earth sciences – the emergence of plate tectonics, the discovery of UHP minerals in chromite-bearing ultrabasites, – intensified the scientific search and led to the emergence of alternative models that consider chromitites as products of metasomatism or metamorphism. Particular attention is paid to the results of research by Russian experts, whose scientific contribution to the development of ideas about the genesis of chromium ores is very large and at the same time, from our point of view, underestimated. This work is intended for geologists, petrologists, and experts in the geology of ore deposits dealing with ultramafic, chromic ores, and ophiolite complexes in general.

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Eric, R. H. "Chromous capacities of ferrochromium and matte smelting slags". Archives of Materials Science and Engineering 2, n. 93 (1 ottobre 2018): 49–58. http://dx.doi.org/10.5604/01.3001.0012.7354.

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Purpose: of this paper is to extend the slag capacity concept to sparingly soluble cationic species encountered for example in matte smelting and ferrochromium processing in terms of chromous capacities. Design/methodology/approach: In this context in order to develop the chromous capacity the experimental data on slag-metal equilibrium for ferrochromium smelting and on chromium distribution between slag and matte phases encountered in sulphide smelting of PGM (Platinum Group Metals) and chromium containing copper nickel concentrates were used. Findings: The calculated chromous capacities were in the 10-8 range for ferrochrome smelting slags and 10-4 range for matte smelting slags. These values indicate the very low and moderate chromous ion dissolving ability of ferrochromium smelting slags and matte smelting slags respectively. Research limitations/implications: Due to highly reducing conditions in ferrochromium smelting and the imposed low oxygen partial pressures in sulphide smelting of chromium and PGM containing concentrates chromium in the slag was assumed to be in its divalent state. The slag-metal/matte reaction for dissolution of chromium into the slag as a cation under reducing conditions -in contrast to reactions for dissolution of species such as sulphur and phosphorus into the slag as anions under oxidizing conditions – required the release of electrons. Thus to maintain charge neutrality the dissolution of chromium from the metal or the matte phases into the slag as Cr2+ ions was accompanied by consumption of these electrons by reduction of Fe2+ ions in the slag into metallic Fe which dissolved in the metal/ matte phase. This was supported by the experimental equilibrium data. Hence the slagmetal/ matte reaction defining the chromous capacity involved both O2- and Fe2+ ions of the slag phase. Moreover for matte smelting the thermodynamic activities of species in the matte phase were assumed to conform to ideal associated solution model due to lack of data. For future work it is advisable to determine such activities. Practical implications: The calculated chromous capacities were in the 10-8 range for ferrochrome smelting slags and 10-4 range for matte smelting slags. The results clearly indicate that in matte smelting lower basicity slags would be preferable to render chromium more soluble in the slag in contrast to ferrochromium smelting where higher basicity slags would be suitable to minimize chromium losses to the slag. Originality/value: This research and hence the paper is probably the first on dissolution of chromium as chromous ion in slags, thus it is novel and original.

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Liu, Hao Rui, e Chang Xin Nai. "Research on Environmental Materials with Complex Resistivity Dispersion Properties of Chrome-Contaminated Soil". Applied Mechanics and Materials 540 (aprile 2014): 263–66. http://dx.doi.org/10.4028/www.scientific.net/amm.540.263.

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The complex resistivity dispersion experiment of the soil with different water content and different chromic salt content is the base of the complex resistivity detection method which will be used for evaluating the field polluted by chromium residue. By the soil complex resistivity dispersion properties experiment in kinds of conditions, we find that complex resistivity amplitude, phase, in-phase resistivity and out-phase resistivity can be influenced by the water content and contamination content; but the complex phase and out-phase resistivity have the obvious dispersion properties. The experiment result shows that the complex resistivity detection technology based on soil dispersion properties can be used to evaluate the field polluted by chromium residue.

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Chen, Yong, e Xiao Li Wen. "Chromium-Containing Solid Waste Soluble Six Chromium Leaching Influence Factor Research". Advanced Materials Research 482-484 (febbraio 2012): 2496–99. http://dx.doi.org/10.4028/www.scientific.net/amr.482-484.2496.

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Through the research of determining chromium-containing solid waste in different leaching conditions of Cr6+ leaching concentration, get Cr6+ leaching conditions, for the follow-up of the harmless treatment to provide reliable technical parameters.

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Shi, Yu Min, Tong Wang, Cheng Hu, Lin Bai e Zhi Tong Sui. "Research on Detoxifying Treatment to Chromium Slag". Advanced Materials Research 402 (novembre 2011): 61–65. http://dx.doi.org/10.4028/www.scientific.net/amr.402.61.

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A particular industrial waste was selected as reducer for detoxified chromium slag in solid phase. Oxidation resisting was also tested. The results showed that concentration of Cr(Ⅵ)in the products was related to experimental condition, such as the proportion of chromium slag, the granularity of reactants, the reaction temperature and time . The leached Cr(Ⅵ)in the products was remained below 0.5 ppm of GB8978-1996 limits.

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Veillon, Claude, e Kristine Y. Patterson. "Analytical issues in nutritional chromium research". Journal of Trace Elements in Experimental Medicine 12, n. 2 (1999): 99–109. http://dx.doi.org/10.1002/(sici)1520-670x(1999)12:2<99::aid-jtra7>3.0.co;2-m.

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Chen, Da Qing, Hai Bin Wang, Ji Chuan Huo, Yong Lin Lei e Wei Ai. "The Research of the Orgince Silicone Emulsion Hybridized Chromium-Aluminum Phosphate Composites". Advanced Materials Research 699 (maggio 2013): 519–23. http://dx.doi.org/10.4028/www.scientific.net/amr.699.519.

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In the paper ,the preparation of the orgincesilicone emulsion hybridized chromium-aluminum phosphateand thecomposites was studied.The aluminum-chromium-phosphate washybridizedbyadding the orgincesilicone emulsio-n, the tensile lap-shear strength of the hybridized aluminum-chromium-phosphateincreasedfrom1.2MPato4.0MPaor more, its dielectricconstantwasreducedfromabout 4.0toabout3.6; the flexural strength of the composites was increased from80Mpa tomore than120Mpa and the the moisture rate of the composites reduced to about 1.6%

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Li, Xue Lei, Xiao Hang Liu, Hao Bin Tian e Wen Jing Yuan. "Experimental Research on Hard and Crack-Free Electrodeposited Chromium Coatings". Advanced Materials Research 1044-1045 (ottobre 2014): 47–52. http://dx.doi.org/10.4028/www.scientific.net/amr.1044-1045.47.

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In order to eliminate cracks in the chromium coating, a novel method named flexible extrusion assisted chromium electroplating was proposed. The bright and crack-free chromium coatings were electrodeposited by using the perturbation and extrusion of hard and insulating particles. The prepared deposits were characterized by scanning electron microscope (SEM) and three-dimensional topography. The testing results showed that the surface was very smooth and there was no micro cracks in the coating. Micro hardness of the electrodeposited layer was also tested. It was confirmed that the chromium coating electrodeposited with rotating cathode in hard particles had high micro hardness as to 850HV and the micro hardness could be controlled by the process parameters. The rule of the micro hardness was concluded by analyzing current density and rotating speed. In addition the results of salt spray test and electrochemical polarization curve showed that the coating deposited by new method had higher corrosion resistance than that by traditional method.

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Xu, Liu Jie, Guo Shang Zhang, Ji Wen Li, Zhan Wu Dong e Shi Zhong Wei. "Research on Microstructure and Mechanical Properties of High Boron Cast Steel". Advanced Materials Research 189-193 (febbraio 2011): 3968–71. http://dx.doi.org/10.4028/www.scientific.net/amr.189-193.3968.

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In recent years, high chromium cast irons have been widely applied in many fields because they have high hardness and abrasion resistance. However, high chromium cast irons are also expensive because much alloying elements, such as chromium, molybdenum and nickel, are added into them. In order to resolve above question, a new abrasion-resistant steel with high boron content was developed in this paper. The new high boron steel, with 0.6%~0.8%B and 0.65% C, was prepared using sand casting method. The microstructure and mechanical properties were researched. The results show that the solidification microstructure of as-cast high boron steel consists of boride (FeB) and matrix composed of pearlite, ferrite, and bainite. And the borides distributes along grain boundary in the form of network. After quenching at 980°C and tempering at 250°C, the FeB transforms to Fe2B, and the matrix transforms lath martensite. The hardness of as-cast high boron steel is 43HRC, and its impact toughness is 5J/cm2. After heat treatment, they increase to 56 HRC and 7J/cm2, respectively, approximating that of high chromium cast irons. The new high boron cast steel have a potential in stead of high chromium cast irons

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Li, Bao Yuan, Hong Bo Guo, Liu Jie Xu, Shi Zhong Wei, Kun Wu, Xiong Yang e Guang Du. "Research on Corrosive Wear Properties of Super High Chromium Cast Iron". Advanced Materials Research 1094 (marzo 2015): 292–95. http://dx.doi.org/10.4028/www.scientific.net/amr.1094.292.

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National standard high chromium cast iron contains 26% chromium by weight (Cr26). A new type of Super High Chromium Cast Iron (SHCCI) has been developed with chromium content of about 37% by weight. This paper examines the microstructure of SHCCI using SEM and XRD. The hardness and toughness of SHCCI was studied and the corrosive wear properties of SHCCI were also examined using an MCF-30 type erosion abrasion tester under H3PO4 media. The results show that, the microstructure of SHCCI is composed of M7C3 and M23C6 carbides, martensite matrix and residual austenite matrix. With proportionately greater carbon content, the hardness of SHCCI will first increase and then decrease, while the toughness and corrosive wear properties will decrease gradually SHCCI’s corrosive wear performance was significantly better than that of Cr26 cast iron. The maximum wear capacity of SHCCI is three times higher than that of Cr26 cast iron.

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Fomichev, V. T., A. V. Savchenko e G. P. Gubarevich. "Functional Galvanic Coatings of the Cr-Zn System". Materials Science Forum 945 (febbraio 2019): 688–94. http://dx.doi.org/10.4028/www.scientific.net/msf.945.688.

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The authors have studied the influence of the electric current density, temperature, electrolyte composition on the properties of electroplating Chromium-Zinc deposits. The dependence of the maximum yield of metal on the physico-chemical characteristics of the solutions for electroplating of Chromium and Cr-Zn alloy has been shown. Chromium-Zinc coatings have been obtained from electrolytes based on chromic acid in the presence of organic additive (4-methylaminophenol). Abrupt nonlinear changes in density, viscosity, surface tension, specific electrical conductivity due to structural transformations in electrolytes are observed at the concentration of zinc sulphate of 4070 gramm / litr (further in the text - g/l), and the organic additive of 2-5 g/l. The obtained model has been applied to predict the optimal electrolyte compositions for the processes of Cr-Zn alloy formation, which will allow reducing the research efforts concerning the electrochemical studies of the given process when chromic acid solutions are used. The coatings exhibit high hardness, corrosion resistance, wear resistance, low internal stresses.

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Liu, Yan, Mao Fa Jiang e De Yong Wang. "Research on the Thermodynamics and Kinetics of Chromium Ore Smelting Reduction Process for Producing Stainless Steel". Applied Mechanics and Materials 401-403 (settembre 2013): 704–7. http://dx.doi.org/10.4028/www.scientific.net/amm.401-403.704.

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For describing and resolving the process of chromium ore smelting reduction preferably, the research status on the thermodynamics and kinetics of chromium ore smelting reduction process was summarized, based on the introduction of the process for smelting stainless steel with hot metal in a converter. The existing problems for smelting stainless steel by chromium ore smelting reduction in a converter were also discussed and some suggestions were made for the future work. A lot of investigations about the thermodynamics and the reduction mechanisms of chromium ore have been done. However, the consistent view about the thermodynamic feasibility and the mechanism of smelting reduction has not been achieved, so the application of research results is limited. Little work about the reaction kinetic model for the production of stainless steel by chromium ore smelting reduction and direct alloying has been done. So the synthetic kinetic model including a dissolution model and a reduction model of chromium ore should be built to predict and control accurately the process.

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Gidikova, N., M. Sulowski, V. Petkov, R. Valov e G. Cempura. "Composite Coatings of Chromium and Nanodiamond Particles on Steel". Archives of Metallurgy and Materials 62, n. 4 (1 dicembre 2017): 2421–24. http://dx.doi.org/10.1515/amm-2017-0356.

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AbstractChrome plating is used to improve the properties of metal surfaces like hardness, corrosion resistance and wear resistance in machine building. To further improve these properties, an electrodeposited chromium coating on steel, modified with nanodiamond particles is proposed. The nanodiamond particles (average size 4 nm measured by TEM) are produced by detonation synthesis (NDDS). The composite coating (Cr+NDDS) has an increased thickness, about two times greater microhardness and finer micro-structure compared to that of unmodified chromium coating obtained under the same galvanization conditions. In the microstructure of specimen obtained from chrome electrolyte with concentration of NDDS 25 g/l or more, “minisections” with chromium shell were found. They were identified by metallographic microscope and X-ray analyser on etched section of chromium plated sample. The object of further research is the dependence of the presence of NDDS in the composite coating from the nanodiamond particles concentration in the chroming electrolyte.

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Lomakin, Viktor, Volodymyr Kropivnyi, Viktor Pukalov e Lyudmyla Molokost. "Research and Comparative Analysis of Wear Resistance of Cast Grinding Media From Chromium Cast Irons". Central Ukrainian Scientific Bulletin. Technical Sciences 2, n. 5(36) (2022): 51–57. http://dx.doi.org/10.32515/2664-262x.2022.5(36).2.51-57.

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A study was made of the impact-abrasive wear resistance and impact resistance of grinding bodies cast in a multi-place mold. Three types of chromium cast irons were adopted for the study: low chromium (~1% Cr), medium chromium (up to 5% Cr) and high chromium (up to 20% Cr). The macro- and microstructure of these alloys as a material for cast grinding balls has been studied. Installed an increase in the impact-abrasive wear resistance and impact resistance of such products with an increase in the mass fraction of chromium in cast iron due to the formation of carbides of the (Fe, Cr)3C and especially (Fe, Cr)7C3. Balls were cast in multi-seat chill molds. Cast iron was smelted in a medium-frequency induction furnace, such as IChT, with the main lining on a charge of pure pig iron and steel low-carbon scrap. The temperature of cast iron production was 1500 °C. Liquid cast iron was subjected to alloying with medium carbon ferrochrome. The wear resistance of cast irons was determined on samples cut from balls in the radial direction. The tests were performed in a laboratory mill When tested for impact resistance, the grinding ball received a striking blow of mass 50 kg, falling from a height of 0,5 m. The frequency of application of dynamic loads was 10 beats per minute. Impact resistance was determined by the average number of impacts sustained by the grinding body prior to destruction. Nevertheless, significant excess of the cost high-chromium over low-chromium cast iron forces us to agree with the opinion of the majority of researchers and the practice of production of such metal products. In today's conditions, low-chromium white cast iron is an economically viable material for grinding media.

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Arishi, Amr, e Ibrahim Mashhour. "Microbial Mechanisms for Remediation of Hexavalent Chromium and their Large-Scale Applications; Current Research and Future Directions". Journal of Pure and Applied Microbiology 15, n. 1 (22 febbraio 2021): 53–67. http://dx.doi.org/10.22207/jpam.15.1.32.

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The increase of anthropogenic activities has led to the pollution of the environment by heavy metals, including chromium (Cr). There are two common oxidative states of Cr that can be found in industrial effluents the trivalent chromium Cr(III) and the hexavalent chromium Cr(VI). While the hexavalent chromium Cr(VI) is highly toxic and can trigger serious human health issues, its reduced form, the trivalent chromium Cr(III), is less toxic and insoluble. Leather tanning is an important industry in many developing countries and serves as a major source of Cr(VI) contamination. Globally, tannery factories generate approximately 40 million m3 of Cr-containing wastewater annually. While the physico-chemical treatments of tannery wastewater are not safe, produce toxic chemicals and require large amounts of chemical inputs, bioremediation using chromium-resistant bacteria (CRB) is safer, efficient and does not produce toxic intermediates. Chromium-resistant bacteria (CRB) utilise three mechanisms for Cr(VI) removal: biotransformation, biosorption and bioaccumulation. This review will evaluate the three Cr(VI) detoxification mechanisms used by bacteria, their limitations and assess their applications for large-scale remediation of Cr(VI). This can be helpful for understanding the nature of Cr(VI) remediation mechanisms used by bacteria, therefore, bridging the gap between laboratory findings and industrial application of microorganisms for Cr(VI) removal.

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Gu, Li Ping, Shao Guang Liu, Dong Liang Gu e Yu Song Xu. "Failure Analysis and Research Progress of Resurfacing Welding Material of Coal Mill Roller". Advanced Materials Research 873 (dicembre 2013): 514–18. http://dx.doi.org/10.4028/www.scientific.net/amr.873.514.

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Failure mode of coal mill roller was comprehensively analyzed and current situation of mill roller repair was elaborated. Process characteristic and application effect of metal cerement and high chromium cast iron building-up materials were expounded in the article. Owing to excellent wear resistant and low cost, high chromium cast iron building-up materials have been applied widely. The current research situation of self-shielded flux-cored wire with high chromium cast iron was summarized and the existing problem and probable solution were pointed. Key word: Coal mill roller, Abrasive wear, Flux-cored wire, Resurfacing welding

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Gochfeld, M. "Setting the research agenda for chromium risk assessment." Environmental Health Perspectives 92 (maggio 1991): 3–5. http://dx.doi.org/10.1289/ehp.91923.

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Islam, Md Aminul, Michael J. Angove e David W. Morton. "Recent innovative research on chromium (VI) adsorption mechanism". Environmental Nanotechnology, Monitoring & Management 12 (dicembre 2019): 100267. http://dx.doi.org/10.1016/j.enmm.2019.100267.

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Rizky, Hana Eka, e Jojok Mukono. "Levels of Chromium in Air with Chromium in the Blood of Workers Electroplating in Purbalingga". JURNAL KESEHATAN LINGKUNGAN 9, n. 2 (27 luglio 2018): 172. http://dx.doi.org/10.20473/jkl.v9i2.2017.172-180.

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Chromium (VI) is a form of chromium which commonly used in metal plating industry with engineering electroplating. The negative impacts for workers when contact with chromium are, skin irritation, nose, throat and lungs irritations. Research purposes are to describe the levels of chromium in the air and the blood of electroplating workers. This was an observational research design with cross sectional approach. Data analyzed by descriptive methods. Population of this research were electroplating workers of metal plating industry in Purbalingga. The samples were consisted of the respondents and environmental samples. The number of respondents were 8 workers which determinated purposive sampling methods. Environmental samples were obtained by measurements the levels of chromium in the air. The results showed that average level of chromium in the air 0.01 mg/m3. This level was appropriate to threshold limit value according to Peraturan Menteri Tenaga Kerja Dan Transmigrasi RI 13/MEN/X/2011. Most of electroplating workers (87.5%), had the high levels of chromium blood (1.7 μg/L) and exceeded the normal limit value. Metal coating business owners should regularly control the use of personal equipment for workers to reduce the exposure of chromium for them.

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Suárez García, Óscar Javier. "Obtaining decorative chromium plating from trivalent chromium solutions". Ingeniería e Investigación 26, n. 2 (1 maggio 2006): 75–83. http://dx.doi.org/10.15446/ing.investig.v26n2.14739.

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The present work was aimed at a qualitative evaluation, in the laboratory, of different alternatives for assembling and operating a trivalent chromium bath for decorative chromium plating. Different chromium concentration solutions and different complexing agents were used. The initial result of this analysis was that chloride, formate and acetate solutions produced the best results. Solution preparation conditions were evaluated: temperature, chromium III complex formation time and also operation during the plating process: pH and temperature. The experimental work was done in the Alfacrom Ltda company; the parameters evaluated consisted of the appearance of chromium deposit and the minimum current density at which it appeared. Resistance to corrosion was tested in a saline-spray chamber, taking conventional hexavalent chromium plating as reference. This assay was done in the Universidad Nacional de Colombia’s Chemical Engineering Laboratory. It was concluded that trivalent chromium plating may represent a technical and economic alternative to conventional hexavalent chromium plating, this being a highly toxic and contaminant process. However, research should be continued into finding optimal process conditions.

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Martinuzzi, Stefano Mauro, Lorenzo Donati, Walter Giurlani, Federico Pizzetti, Emanuele Galvanetto, Nicola Calisi, Massimo Innocenti e Stefano Caporali. "A Comparative Research on Corrosion Behavior of Electroplated and Magnetron Sputtered Chromium Coatings". Coatings 12, n. 2 (15 febbraio 2022): 257. http://dx.doi.org/10.3390/coatings12020257.

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Chromium deposits rank among the most widespread metal coatings for functional and decorative purposes. However, electrodeposition from Cr(VI) aqueous solution, which is the industrial process currently used to achieve thin chromium deposits, presents several environmental issues, urging the development of alternative solutions. In this study, which aims to compare the functional and aesthetical properties of decorative coatings, 800 nm thick chromium layers were deposited directly onto copper substrates by means of magnetron sputtering (MS) and direct current electrodeposition (ED). The obtained coatings were characterized regarding their thickness, morphology, color index, chemical composition, and corrosion resistance viewpoints. With respect to the electroplated samples, which constitute the benchmark, the magnetron sputtered ones appeared to be darker but showed a pleasing reflective appearance and superior thickness homogeneity, as well as the absence of voids and macrocracks, as evidenced by scanning electron microscopy (SEM) investigation. Regarding the anticorrosion performances of the chromium layers, electrochemical and standard salt spray test (NSS test) were carried out at room temperature in 3.5% NaCl solution, and evidenced similar, if not better, results for the magnetron sputtered coatings. On the whole, the data displayed here demonstrates the suitability of magnetron sputtering technology for use as an industrially feasible finishing technology for both aesthetic and mild-condition anticorrosion purposes.

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Chauhan, Jasgurpreet Singh. "A Bibliometric Analysis and Visualisation of Research Trends in Allergy of Chromium Implants". Turkish Journal of Computer and Mathematics Education (TURCOMAT) 12, n. 2 (11 aprile 2021): 45–50. http://dx.doi.org/10.17762/turcomat.v12i2.674.

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The metal hypersensitivity of implants is a vital factor affecting the safety of implants. The bibliometric analysis had been conducted to understand the active authors, organizations, journals, and countries involved in the research domain of “allergy of Chromium implants”. All published articles related to “allergy of Chromium implants” from “Scopus”, were analyzed using the VOS viewer to develop analysis tables and visualization maps. This article had set the objective to consolidate the scientific literature regarding “allergy of Chromium implants” and also to find out the trends related to the same. The most active journal related to this research domain was Contact Dermatitis. The most active countries were the United States of America and Germany. The leading organization was Ludwig Maximilian University of Munich, Germany. The most active authors who had made valuable contributions related to the allergy of implants was Thomas P.

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P.Faux, Stephen, Min Gao, James K. Chipman e Leonard S. Levy. "Production of 8-hydroxydeoxyguanosine in isolated DNA by chromium(VI) and chromium(V)". Carcinogenesis 13, n. 9 (1992): 1667–69. http://dx.doi.org/10.1093/carcin/13.9.1667.

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Fitrianto, Nur, Siti Samiyarsih, Dede Winda Nur Fauziah e Sri Lestari. "THE EFFECT OF CHROMIUM STRESS ON MICRO-ANATOMICAL PROFILE OF CHILI (Capsicum annuum L.)". BERITA BIOLOGI 20, n. 1 (10 maggio 2021): 103–13. http://dx.doi.org/10.14203/beritabiologi.v20i1.3866.

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Chromium contamination can affect morphological, physiological, and anatomical changes, especially in chili vegetative organs. This research aims to understand micro-anatomical structure of the vegetative organs of chili subjected to chromium stress. The aim of the research is to know whether there is a micro-anatomical character difference between contaminated and uncontaminated chromium. The experimental methods using a completely randomized design (CRD). The independent variable is five levels of chromium concentration, i.e., 0; 50; 100; 200; and 300 ppm. The method of preparing anatomical preparations of the stem using a non-embedding and embedding method. The parameters observed in root and stem are organ diameter, xylem, thick of epidermis, and cortex. In contrast, leaf organ parameter includes thick cuticle, epidermis, mesophyll, stomata size (length and width), and stomatal number. The research results showed that organ anatomical structure, i.e., root, stem, and leaf in chromium stress condition did not change. Chromium deposition causes a decrease in root diameter, xylem, thick cortex roots, stem diameter, xylem, the thickness of the epidermis and cortex, leaf epidermal thickness, mesophyll, size of stomata width and number. In contrast, the chromium stress causes an increase in the thickness of the root epidermis (43,18%), cuticle thickness (36,36%), and leaf stomata length (33,33%) of chili as chromium concentrations increase. The anatomical structure of chili leaves changes after being contaminated chromium stress.

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26

Gill, Rana. "A Bibliometric Analysis and Visualisation of Research Trends in Toxicity of Chromium Implants". Turkish Journal of Computer and Mathematics Education (TURCOMAT) 12, n. 2 (11 aprile 2021): 126–30. http://dx.doi.org/10.17762/turcomat.v12i2.689.

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The toxicity of implants is a vital factor affecting the safety of implants. The bibliometric analysis had been conducted to understand the active authors, organizations, journals, and countries involved in the research domain of “toxicity of Chromium implants”. All published articles related to “toxicity of Chromium implants” from “Scopus”, were analyzed using the VOS viewer to develop analysis tables and visualization maps. This article had set the objective to consolidate the scientific literature regarding “toxicity of Chromium implants” and also to find out the trends related to the same. The most active journals in this research domain were the Journal of Biomedical Materials Research, Journal of Bone and Joint Surgery, and Biomaterials. The most active country was the United States of America. The leading organizations were the University Medical Center and the University of Strathclyde. The most active authors were Grant M.H., Jacobs J.J, and Savarino I.

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27

Bawane, Shivani S., e Dr A. M. Nikalje. "Effect of Hard Chroming on Wear Loss of Rotavator Blade". International Journal for Research in Applied Science and Engineering Technology 10, n. 10 (31 ottobre 2022): 594–99. http://dx.doi.org/10.22214/ijraset.2022.47053.

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Abstract: Rotavator is the most important equipment which has been increasingly used in agricultural fields. To decrease the human effort and total time required in soil bed preparation. During the working condition, the rotary tilleris subjected to extreme abrasive wear. This problem is faced all over the world. Which considerably affects the service life of the tiller blade. Due to the abrasive wear, the rotavator blade requires frequent replacement resulting in increasing machine downtime and maintenance costs. So, it is necessary to improve the service life of the tiller blade. In the present research work laboratory test was conducted on rotavator blade specimen. Hard chroming is used as a surface modification technique, experimentation was conducted to evaluate the effect of chromium coating on the mechanical properties of the base material. The addition of chromium increases the surface hardness of the tiller blade. Tribometer is used for the wear testing method, to study the wear resistance of the coated and uncoated blade. Taguchi L9 array to optimize the laboratory investigation used in the present research work. Wear performance of hard chroming and the unhardchrome blade is examined after a fixed interval of time in terms of weight loss.

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Marushko, Yu V., N. G. Kostynska, T. V. Hyshchak e T. V. Marushko. "The biological role of chromium and the impact of changes in its content on the course of obesity and hypertension in children (literature review, own research)". Modern pediatrics. Ukraine, n. 3(123) (30 aprile 2022): 73–79. http://dx.doi.org/10.15574/sp.2022.123.73.

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Abstract (sommario):

The study of the role of certain microelements deficiency in the human body has not lost its relevance for decades. One of these microelements is chromium. Given its ability to reduce oxidative stress and chronic inflammation in the human body, much attention is being paid to studying the role of chromium in the treatment of obesity and hypertension. A number of scientists in their studies have shown a positive effect of chromium supplementation in these diseases. However, a large number of unexplored questions remain. In particular, most of the studies are devoted to the study of isolated diseases, while many patients usually have a comorbidity of several diseases. Also, the study of the role of this microelement in children remains without the attention of scientists. Most scientists note the need for further research in this direction. Purpose - to summarize the literature data and the results of our own studies of the biological role of chromium and the impact of changes in its content on the course of obesity and hypertension in children. Results and conclusions. Today, the role of chromium in the treatment and prevention of obesity and hypertension continues to be studied. According to literature sources, with a decrease in the level of chromium in the blood plasma of patients, obesity and hypertension are statistically significantly more often recorded. In systematic reviews chromium supplementation has been shown to reduce body weight and systolic and diastolic blood pressure in patients with obesity and hypertension. As a result of the study, it was found that the level of chromium in the hair of school-age children with hypertension in combination with obesity is statistically significantly (p<0.01) lower than in healthy peers. No conflict of interests was declared by the authors. Key words: chromium, microelements, obesity, hypertension, comorbidity, children.

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29

Zhan, Guo Feng, En Gang Wang e Ji Cheng He. "Research on Casting of GH3030 Superalloy with Electromagnetic Stirring". Advanced Materials Research 146-147 (ottobre 2010): 105–8. http://dx.doi.org/10.4028/www.scientific.net/amr.146-147.105.

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Abstract (sommario):

The effect of electromagnetic stirring on the inner quality and solidification microstructure of the GH 3030 superalloy ingots was investigated by casting experiments. As we know from the experiments, the solidification microstructure of GH3030 is the single-phase of austenite. With the electromagnetic stirring (EMS) the grains of the GH3030 ingots become finer significantly and the average grain size decrease as the currents of EMS increase. The results also show that the macrostructure of the ingots was improved significantly. The length of the shrinkage cavity with EMS become smaller and the porosity disappeared while the ingots without EMS have much porosity. And yet the macrosegregation always exists whether with EMS or not, but the chromium in the ingots with EMS is better distributed, and consequently the macrosegregation of chromium is inhibited.

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30

Venier, P., A. Montaldi, L. Busi, C. Gava, L. Zentilin, G. Tecchio, V. Bianchi e A. G. Levis. "Genetic effects of chromium tannins". Carcinogenesis 6, n. 9 (1985): 1327–35. http://dx.doi.org/10.1093/carcin/6.9.1327.

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31

Ghadi, A., Mansour Soltanieh e H. R. Karimi Zarchi. "Effect of Salt Bath Composition on the Chromium Diffusion on Plain Carbon Steels by TRD Process". Defect and Diffusion Forum 326-328 (aprile 2012): 377–82. http://dx.doi.org/10.4028/www.scientific.net/ddf.326-328.377.

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The thermo-reactive diffusion (TRD) process is used for diffusing an element to the metallic steel substrate. TRD is carried out by using either salt bath or fluidized bed methods. In this research, the molten salt bath method is used. Ferro chromium was dissolved in the molten borax as the source of chromium in the salt. Samples of cylindrical shape of plain carbon steel with 10 mm diameter and 20 mm height were treated at 1000°C for 14 hours in different baths including either low carbon ferro chromium (LCFC) or high carbon ferro chromium (HCFC) powder. The purpose of this research is to investigate the effect of the salt bath composition on the diffusion of chromium and formation of chromium compound layer on plain carbon steel by using the salt bath method. The coating thickness layers were measured by SEM. The different phases formed on the samples, due to different amounts of carbon in treating salt bath, were determined by X-ray diffraction. It was found that in molten borax salt with high carbon content (high carbon ferro chromium) very few amount of chromium diffused into the plain carbon steel. The thickness of the diffused chromium layer in low and high carbon content ferro chromium in molten borax, is around 32±8 µm and 6.8±1.2 µm, respectively. A number of tests were conducted to address this effect.

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32

Dong, Guo Ri, e Jian She Liu. "Effects of Cr³⁺ on Chromium Adsorption of SBR Activated Sludge System under Different Chromium Loads and Different Initial SVIs". Advanced Materials Research 838-841 (novembre 2013): 2735–38. http://dx.doi.org/10.4028/www.scientific.net/amr.838-841.2735.

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Abstract (sommario):

In allusion to Cr3+s toxic effect on activated sludge in SBR process system, by determination of the Cr3+adsorption rate, mlvss under different initial SVIs and different chromium loads, the Cr3+s toxic effect on activated sludge and the Cr3+s influence on chromium adsorption of activated sludge were studied. The research shows that within tolerance range, the activated sludge of SBR system can adsorb 60% chromium ion within 10min reaction. Moreover, with the increase of chromium load, the final chromium remnant rate decreases; within tolerance range, the increase of chromium load contributes to the adsorption of chromium ion and the acceleration is subject to initial SVI. Within non-tolerance range, the ability of SBR process system to adsorb chromium decreases greatly; The whole curve of chromium remnant rate shifts upward with the increase of chromium load level. Within 10mins reaction, the adsorption rate of chromium is about 50% under best condition.

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33

Gochfeld, M., e C. Witmer. "A research agenda for environmental health aspects of chromium." Environmental Health Perspectives 92 (maggio 1991): 141–44. http://dx.doi.org/10.1289/ehp.9192141.

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34

Kashapov, L. N., N. F. Kashapov e R. N. Kashapov. "Research of cobalt chromium alloy surface morphology after sandblasting". IOP Conference Series: Materials Science and Engineering 69 (11 dicembre 2014): 012017. http://dx.doi.org/10.1088/1757-899x/69/1/012017.

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35

Mertz, Walter. "Chromium Research from a Distance: From 1959 to 1980". Journal of the American College of Nutrition 17, n. 6 (dicembre 1998): 544–47. http://dx.doi.org/10.1080/07315724.1998.10718801.

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36

Tingting, Huang. "Effect of the Temperature on chromium precipitation in faucets". E3S Web of Conferences 290 (2021): 01027. http://dx.doi.org/10.1051/e3sconf/202129001027.

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Abstract (sommario):

The research was studying the chromium precipitation in faucets which were extracted at ambient temperature of 20 ºC, 40 ºC and 60 ºC by extraction solution, the results showed that in general, the chromium extraction in the faucets increased as the temperature rises. And the chromium extraction in different batches and different samples in the same batch varied greatly, mainly affected by materials and the processing technology. After further analysis, the detection showed that Cr VI in chromium precipitation was between 83% and 103% of the total chromium content. This indicated that Cr VI was the main form of chromium in extraction solution, which will be harmful to human health.

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37

Shang, Ling Ling, Ce Shi, Yong Li Zhang e Yong Min Liu. "Research on Metal Ion Removal of Ceramic Printing Wastewater". Advanced Materials Research 664 (febbraio 2013): 369–73. http://dx.doi.org/10.4028/www.scientific.net/amr.664.369.

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Abstract (sommario):

The removal of the metal ions in the ceramic printing wastewater was influenced by using, stirring and precipitating of the solution pH, coagulant PAC, coagulant aid PAM and heavy metal scavenger. This experiment investigated the removal effect of the metal ions in the wastewater under different conditions. Flame atomic absorption spectrometry was adopted for the determination of the concentration of metal ions in the wastewater. The studies have shown that alkalization, PAC coagulation treatment have a role in the removal of metal ions in the ceramic printing wastewater. And the chromium and iron removal rate can reached 74.0% and 61.6% respectively. Heavy metal scavenger also have a better role in the removal of metal ions. And the chromium and iron removal rates were 82.3% and 76.2% respectively without dosing PAC. The number of reaction cell has no significant effect on the removal of metal ions.

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38

Zhang, Bo, Wen Hai Chi, Pei Yang Shi, Cheng Jun Liu e Mao Fa Jiang. "Study on the Clean Production Process of Basic Chromium Sulphate". Advanced Materials Research 887-888 (febbraio 2014): 651–56. http://dx.doi.org/10.4028/www.scientific.net/amr.887-888.651.

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Abstract (sommario):

The pollution of chromium salt industry is increasingly serious in China and becomes a worldwide problem with the rapid development of chromium salt industry. Then a new clean production process with a high recovery rate of chromium and pollution-free was proposed according to the comprehensive summary of existing processes of basic chromium sulphate. Furthermore, a small amount of slag will be discharged in this short process with lower energy consuming. The design concept is also applicable to the preparation of other chromium salts products, which will eliminate the pollution of Cr6+ during the process of chromium salt production and be helpful to the comprehensive utilization of chromium salt. In addition, the guidance of scholar research and the broad application prospects of this work cannot be neglected.

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39

THOMYASIRIGUL, SUREERAT, HITOSHI FUKUDA, JUN HASEGAWA, YOSHIYUKI OGURI e CHAVALIT RATANATAMSKUL. "APPLICATION OF ION EXCHANGE PAPER TO PRECONCENTRATION OF CHROMIUM (III) AND CHROMIUM (VI) IN WATER FOR PIXE ANALYSIS". International Journal of PIXE 18, n. 01n02 (gennaio 2008): 13–19. http://dx.doi.org/10.1142/s0129083508001296.

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Abstract (sommario):

The most important species of chromium (VI) formed in water are anions such as CrO 42-, whereas chromium (III) is mainly present in the form of cationic species such as Cr ( OH )2+. Pure water and tap water samples were artificially contaminated with mixture of chromium (VI) and chromium (III) standard solutions. Sequential filtration through commercially available Whatman P81 cellulose phosphate paper and Whatman DE81 DEAE cellulose paper was employed for separation and preconcentration of chromium (III) and chromium (VI) in these water samples, respectively. The PIXE measurements of these filter paper samples were performed using 2-MeV proton beams delivered by a tandem pelletron accelerator at Research Laboratory for Nuclear Reactors, Tokyo Tech. The beam current and the measuring time for each sample were 1 nA and 10 minutes, respectively. Instrumental detection limits were 60 ng for chromium (VI) and 120 ng for chromium (III). Detectable range for chromium (VI) and chromium (III) in water were ≧ 10 ppb and ≧ 50 ppb, respectively. For chromium (VI), the detectable range was considerably lower than the maximum allowed concentration of 50 ppb for chromium (VI) in both the drinking water standards and the environmental quality standards in many countries.

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40

Mayzarah, Erikha Maurizka, Setyo Sarwanto Moersidik e Lana Saria. "Control of Chromium Hexavalent (Cr -VI) Pollution on Waste Water in Nickel Ore Extraction Industry with Phytoremediation Technology". E3S Web of Conferences 68 (2018): 03011. http://dx.doi.org/10.1051/e3sconf/20186803011.

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The issue that surfaces from the digging of limonite and saprolite zones on nickel ore mining is the oxidation of chromium to chromium hexavalent. The aim of this research is to analyze the efficiency level of phytoremediation technology to reduce chromium hexavalent on waste water of nickel ore mining industry. This study was done in situ to observe the potential of Water Lettuce (Pistia stratiotes) using self-designed experimental devices.. This research was divided into three part, such as the variation of plant’s weight of 10grams, 20grams, 30grams, 60grams, 70grams, and 150grams with interval of an hour for five hours, variation of chromium hexavalent of 0.5ppm, 1ppm, 2ppm, 5ppm, and 7ppm with interval of 4 days for 20 days, and variation HRT 1.5 hours, 2 hours, and 3 hours with interval of 24 hours for 16 days. The result of this research shows the average of efficiency on observation one, two and three are 18.5%, 89%, and 28%. The usage of phytoremediation technology shows the potential to reduce chromium hexavalent pollutant.

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41

Salimin, Zainus, Faldy W. Satiyoaji, Dwi A. Prasetya e Achmad Chafidz. "Chemical Treatment of Liquid Waste Generated from Leather Tannery Industry by Using Alum as Coagulant Material". Materials Science Forum 991 (maggio 2020): 178–84. http://dx.doi.org/10.4028/www.scientific.net/msf.991.178.

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Abstract (sommario):

The tannery industry generally produces trivalent chromium waste (Cr3 +) and hexavalent chromium (Cr6 +). This waste before being released into the environment must meet quality standards according to KEPMENLH no.51 / MENLH / 10/1995 concerning liquid quality standards for industrial activities which says the maximum total chromium content is 0.6 ppm. This study aims to reduce the levels of Chromium in waste produced by the leather tanning industry by using alum coagulants. This research uses simulation waste which is made based on the results of BPPT analysis of waste in the leather tanning industry in Tangerang city, namely CV "Lengtat Tangerang Leather". The method used in this research is coagulation-flocculation with alum as a coagulant and lime as an alum reaction assistant in the form of hydroxide ions. The parameters observed in this study were the pH adjustment and the ratio of alum mass to lime mass. From the results of the study it was found that the decrease in the best chromium content for Cr + 3 occurred at a ratio of 5 and pH 8.2 which resulted in a chromium content of 0.0076 ppm with a decrease in percentage of 99.95%. As for the Cr6 + test, at a ratio of 3 and pH 6.4 the chromium content showed a value of 0.4110 ppm. The lowest chromium level occurs at a ratio of 5 and pH of 5.8 which results in a chromium level of 0.3341 ppm with a decrease percentage of 56.61%.

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42

Gurumurthy Iyer, Vijayan. "Environmental health impact assessment of chrome composite leather-clad rollers used by Indian cotton roller ginning industries and design and development of Eco-friendly alternatives". International Journal of Emerging Trends in Health Sciences 4, n. 1 (30 aprile 2020): 36–67. http://dx.doi.org/10.18844/ijeths.v4i1.4496.

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Abstract (sommario):

This research article realises the hazards of chromium contamination and pollution caused by using chrome composite leather-clad (CCLC) rollers that are commonly used in the cotton roller ginning industries and attempts to eliminate the chromium contamination and pollution during the cotton ginning process. The chromium traces found contain hexavalent chromium being adsorbed from chromium-contaminated lint, yarn, fabrics, seeds, by-products and textile effluent. Chromium acts in three ways on humans, viz. (i) local action explained as dermatitis or absorption through skin, (ii) direct inhalation and (iii) ingestion or absorption into the stomach. Toxic effects are produced by prolonged contact with airborne or solid or liquid chromium compounds even in small quantities because of their properties, viz. carcinogenicity, mutagenicity and corrosiveness. Traces of Cr (VI) are found even in analar grade trivalent compounds, and complications do arise due to reduction in the nature of these traces that affect the organic tissues of the body. These regenerating effects occur rapidly and are dependent on the dose. This research article realises the hazards of chromium contamination and pollution caused by the use of dust-producing grinding of CCLC rollers that are commonly used in the cotton roller ginning industries and attempts to nullify this problem during cotton ginning. This research has been carried out with the following objectives: to identify and study the environmental health effects existing with the present CCLC rollers being used in the Indian cotton roller ginning industries; to conduct an environmental health impact assessment in Indian cotton roller ginning factories during the research years of 1998â€“2018; to design and develop an eco-friendly chrome-free roller and evaluate its performance with reference to environmental health effects and techno-commercial aspects in the ginning industries. With the authorâ€™s research background and practical experience in cotton ginning and textile industries, this study is attempted to eliminate the environmental health impacts to a great extent at the source itself, through a suitable design and development of an eco-friendly, pollution-free, chromeless roller for cotton roller gins. An eco-friendly roller ginning process has been designed and developed for replacing the conventional CCLC roller ginning process, to eliminate the chromium contamination and pollution from cotton roller ginning industries and to meet the requirements of World Health Organisation standards, while maintaining high-quality spun yarns and woven fabrics which meet the international standards. Keywords: Assessment, chromium, ginning, health, impact.

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43

Nriagu, Jerome, Stan Beaubien e David Blowes. "Chemistry of chromium in lakes". Environmental Reviews 1, n. 2 (1 luglio 1993): 104–20. http://dx.doi.org/10.1139/a93-009.

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Abstract (sommario):

The inputs of industrial wastes have changed the levels and forms of chromium in many lakes, and there is growing concern about the accumulation of Cr(VI), a known carcinogen, in drinking water supplies. This report provides a critical review of the effects of speciation, transformations, and solubility on the cycling of chromium in lacustrine environments. Unique features of chromium dynamics associated with the decoupling of redox-driven chromium cycle from those of iron and manganese at the sediment–water and air–water interfaces are highlighted. Reductive precipitation is important in the immobilization of pollutant chromium in sediments. Photooxidative dissolution of Cr(III) especially at the air–water interface is identified as a key area for further research. The available database is inadequate for establishing any linkages between the chromium and biological cycles in lakes.Key words: chromium, lakes, cycling, speciation, redox, geochemistry.

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44

Setyaningsih, Yuliani, Indwiani Astuti e Adi Heru Husodo. "Determinants Levels of Urinary 8-Hydroxydeoxyguanosine among Chromium Electroplating Workers". International Journal of Public Health Science (IJPHS) 5, n. 4 (1 dicembre 2016): 422. http://dx.doi.org/10.11591/ijphs.v5i4.4845.

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Abstract (sommario):

Electroplating workers were exposed by particulate and fog of chromium from electrolysis process during work. Chromium is highly carcinogenic when inhaled. Chromium can be reduced in the cells in the body. This process may generate Reactive Oxygen Species (ROS) causing lipid peroxidation and oxidative DNA damage. This research was aimed to analyse the influence of chromium to the levels of urinary 8-OHdG as an indicator to support early diagnosis of occupational disease. 66 electroplating workers in Tegal District were taken purposively as samples for this research. There were association between chromium level in urine, malondialdehyde (MDA) level, Body Mass Index, smoking habit, alcohol and supplement drink consumption and urinary 8-OHdG (p<0.05). There was not association between BMI and urinary 8-OHdG (p>0.05). Multivariate analysis using logistic regression showed the alcohol consumption had the most powerful influence to the level of urinary 8-OHdG. The levels of urinary 8-OHdG could be used as an indicator of oxidative DNA damage and early diagnosis of occupational disease among electroplating workers who were exposed by chromium.

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45

Setyaningsih, Yuliani, Indwiani Astuti e Adi Heru Husodo. "Determinants Levels of Urinary 8-Hydroxydeoxyguanosine among Chromium Electroplating Workers". International Journal of Public Health Science (IJPHS) 5, n. 4 (1 dicembre 2016): 422. http://dx.doi.org/10.11591/.v5i4.4845.

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Abstract (sommario):

Electroplating workers were exposed by particulate and fog of chromium from electrolysis process during work. Chromium is highly carcinogenic when inhaled. Chromium can be reduced in the cells in the body. This process may generate Reactive Oxygen Species (ROS) causing lipid peroxidation and oxidative DNA damage. This research was aimed to analyse the influence of chromium to the levels of urinary 8-OHdG as an indicator to support early diagnosis of occupational disease. 66 electroplating workers in Tegal District were taken purposively as samples for this research. There were association between chromium level in urine, malondialdehyde (MDA) level, Body Mass Index, smoking habit, alcohol and supplement drink consumption and urinary 8-OHdG (p<0.05). There was not association between BMI and urinary 8-OHdG (p>0.05). Multivariate analysis using logistic regression showed the alcohol consumption had the most powerful influence to the level of urinary 8-OHdG. The levels of urinary 8-OHdG could be used as an indicator of oxidative DNA damage and early diagnosis of occupational disease among electroplating workers who were exposed by chromium.

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46

Yang, Jing Po, Fei Lu, Jian Mei Luo e Jing Chen. "RFLP Analysis of Soil Microbial Diversity Chromium Contaminated Soil Remediation Process". Applied Mechanics and Materials 716-717 (dicembre 2014): 1039–42. http://dx.doi.org/10.4028/www.scientific.net/amm.716-717.1039.

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Abstract (sommario):

Chromium contaminated soil restoration has been an important environmental restoration research. Changes of microbial diversity repair, repair tools can reflect the interaction with microbial interaction effect. The experiment uses a different repair methods chromium contaminated soil restoration for the study, using PCR-RFLP study the relationship between chromium contaminated soil remediation technology and changes in bacterial communities.

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47

Тюсенков, Антон, Anton Tyusenkov, Алексей Рубцов, Alexey Rubtsov, Камилла Мирхайдарова e Kamilla Mirkhaidarova. "Pipe high-temperature strength research of pyrolysis furnace". Science intensive technologies in mechanical engineering 2018, n. 5 (19 aprile 2018): 45–48. http://dx.doi.org/10.12737/article_5ad8d2928f4af3.41991916.

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Abstract (sommario):

The investigation results of the dependence of high alloy steel gas corrosion rate upon temperature are presented. Steel high corrosion-resistance is achieved at the introduction in steel alloy elements (chromium, aluminum, nickel). Steel 10C23N18 (a new sample and a sample from the furnace coil operated 6800h) and steel 10C17N13M2T at temperatures 500… 1000ºC were tested for heat-resistance.

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48

Rosanto, Yosaphat Bayu, W. Widjijono e Teguh Triyono. "Pengaruh konsentrasi cobalt chromium pada uji hemolisis sebagai implan gigi". Majalah Kedokteran Gigi Indonesia 2, n. 3 (30 dicembre 2016): 116. http://dx.doi.org/10.22146/majkedgiind.10737.

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Abstract (sommario):

The effect of concentration of cobalt chromium in hemolysis test for dental implant. Dental implants are used to replace tooth/teeth loss and its function. Cobalt chromium has ideal characteristics to be made as dental implants material. It is required that the material to be implanted must be biocompatible with cells and tissues. One of biocompatibility characteristics is hemocompatibility. Hemocompatibility of materials can be observed with hemolysis test. Thus the purpose of this research is to know whether cobalt chromium as dental implants material affect the hemolysis of rabbit blood or not. This research was done with rabbit blood (Oryctolagus cuniculus) and devided into 3 groups (treatment, positive and negative control). The tested material was cobalt chromium Remanium® GM 800, a product from Dentaurum. The contact between blood and material was done with ASTM-F075 hemolysis test. Cobalt chromium was not hemolytic at 2,5%, 5%, and 10% of concentration, slightly hemolytic at 20% of concentration, and hemolytic at 40% and 80% of concentration. The conclusion of this research was variety of concentration of cobalt chromium affected hemolysis percentage signi cantly.ABSTRAKImplan gigi digunakan untuk mengganti gigi yang hilang untuk dan dapat mengembalikan fungsi gigi. Cobalt chromium memiliki sifat-sifat yang memenuhi persyaratan sebagai material implan. Material yang diimplankan dalam tubuh harus memiliki sifat biokompatibilitas. Salah satu sifat biokompatibilitas yang harus dimiliki material yang diimplankan dalam tubuh adalah sifat hemokompatibilitas. Sifat hemokompatibilitas dapat diketahui dengan uji hemolisis. Penelitian ini bertujuan untuk mengetahui ada/tidaknya pengaruh logam cobalt chromium sebagai material implan gigi terhadap hemolisis pada darah kelinci. Penelitian ini dilakukan menggunakan sampel darah yang didapat dari kelinci (Oryctolagus cuniculus) yang dibagi menjadi 3 kelompok, yaitu perlakuan, kontrol positif dan negatif. Bahan penelitian yang diuji adalah cobalt chromium Remanium GM 800 produksi Dentaurum. Kontak darah dengan bahan uji dilakukan menggunakan uji hemolisis ASTM-F075. Hasil penelitian menunjukkan material logam cobalt chromium tidak menimbulkan hemolisis pada konsentrasi 2,5%, 5%, dan 10%, menimbulkan hemolisis ringan pada konsentrasi 20%, dan hemolisis pada konsentrasi 40% dan 80%. Kesimpulan dari penelitian ini adalah perbedaan konsentrasi logam cobalt chromium berpengaruh secara signikan terhadap persentase hemolisis.

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Anggraeny, Dhea Try, Khothibul Umam Al Awwaly e Abdul Manab. "Physicochemical Charastaristics of Leather Goat Quality from less Tanning Process". Journal of Environmental and Agricultural Studies 3, n. 3 (13 ottobre 2022): 39–49. http://dx.doi.org/10.32996/jeas.2022.3.3.5.

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This research is to determine the percentage of chromium and the type of solvent in terms of the physicochemical quality of wet blue and leather from the waterless tanning process. This research was carried out from November 2021 to February 2022 at the Laboratory of the Yogyakarta Center for Leather, Rubber, and Plastics. The research method used was a Nested Completely Randomized Design (CRD) with 2-factor nested patterns, Factor 1 is percentage of chromium (A = 3%, B = 4% and C = 5%) and factor 2 namely different types of solvents (L1 = Water, L2 = Ethanol and L3 = acetone) with 3 replications. The materials used in this study were Etawa crossbreed goat skin and chromium, and the type of solvents was water, ethanol, and acetone. The variables observed were the physicochemical quality of the finished leather (stricter strength, tensile strength, elongation at break, moisture content, total chromium, ash content, fat content, and pH). The data obtained from the results of the research were analyzed using Analysis of Variance (ANOVA) if there were significantly different results obtained, followed by Duncan's Multiple Range Test (DMRT). On the physicochemical quality of the finished leather (leather), the results of this study showed that the type of solvent had a very significant difference (P < 0.01) in the physicochemical quality of the leather except for pH. The percentage of chromium nested in the type of solvent showed a very significant difference (P<0.01) in the quality of the finished leather. Based on the results of the research, the percentage of chromium nested in the type of solvent was about SNI 2981:2009; from this study, it can be concluded that Phase I research had the physicochemical quality of finished leather with an average stricter strength of 14.40 N/ cm2, tensile strength 15.40 N/cm2, elongation at break 54.32%, water content 4.76%, total chromium 3.64%, ash content 4.62%, fat content 2.44% and pH 4.41.

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Hołda, Anna. "Hexavalent Chromium Accumulation by Microscopic Fungi". Archives of Environmental Protection 39, n. 2 (1 giugno 2013): 45–56. http://dx.doi.org/10.2478/aep-2013-0011.

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Abstract The purpose of the study was to optimize the removal of Cr(VI) by means of the Trichoderma viride strain isolated from chromium mud samples a well as the Aspergillus niger and Penicillium citrinum strains from other environments. The growth of organism and removal of chromium(VI) was carried out in water solution of various chromium(VI) contents. The research was carried out at optimal pH for each fungus i.e. Aspergillus niger 4.0, Penicillium citrinum 5.0 and Trichoderma viride 4.5. During 14 days of incubation, samples of 5 ml each were collected every day in order to determine chromium(VI) content in the solution and the efficiency of bioaccumulation of this element was then specified. Furthermore, chromium contents in filtrate and mycelium were checked to verify this type of biological activity of microorganisms. The fungi culture investigated in this study could grow at 10-125 mg/l chromium concentration which indicated that it was characterized by high tolerance to various concentrations of chromium. At 125 mg/l chromium, these organisms could accumulate successfully about 90% of chromium. High tolerance of this culture can make it a potential candidate to be a heavy metal scavenger of chromium.

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