Thermochemical cycle based on solid intermediates for hydrogen storage and on-demand production

Thermochemical water splitting processes based on Sulfur-Iodine cycle can be conveniently improved using solid intermediates, in order to increase the global yield and avoid the use of concentrated acid at high temperatures. In this context, an innovative process has been conceived, where a metal oxide, namely NiO, is reduced into oxygen and the correspondent metal, which can be suitably stored and reacted with steam into hydrogen when and where necessary. Data previously obtained and published, together with the integration of experimental results have been used to evaluate the technical feasibility and the heat duties of each step of the proposed cycle. The starting point was a Nickel compounds based process already extensively characterized, which has been modified using low toxic Iron (III) species as intermediates for oxygen formation. Based on the theoretical and experimental analysis carried out, the resulting cycle thermal efficiency is quite promising, about 19%, also taking into account the hydrogen generation step.

Exposures to IARC Carcinogenic Agents in Work Settings Not Traditionally Associated with Sinonasal Cancer Risk: The Experience of the Italian National Sinonasal Cancer Registry

The aim of this study is to highlight tasks and jobs not commonly considered at high risk for sinonasal cancer (SNC) identified by Regional Operating Centers currently active in the Italian National Sinonasal Cancer Registry (ReNaTuNS), which retrieve occupational histories through a standardized questionnaire. Data on exposures to IARC carcinogenic agents in work settings unknown to be associated with SNC risk were collected and analyzed. Out of 2208 SNC cases recorded in the ReNaTuNS database, 216 cases and their worked exposure periods were analyzed. Unsuspected jobs with exposure to wood dust include construction-related tasks, production of resins, agriculture and livestock jobs (straw and sawdust), and heel factory work (cork dust). Other examples are hairdressers, bakers (formaldehyde), dressmakers, technical assistants, wool and artificial fiber spinners, and upholsterers (textile dusts). Moreover, settings with coexposure to different agents (e.g., wood with leather dusts and chromium–nickel compounds) were recognized. The study describes jobs where the existence of carcinogenic agents associated with SNC risk is unexpected or not resulting among primary materials employed. The systematic epidemiological surveillance of all epithelial SNC cases with a detailed collection of their work history, as performed by a dedicated population registry, is essential for detecting all potential occupational cases and should be considered in the context of forensic medicine and the compensation process.

Copper Cathode Contamination by Nickel in Copper Electrorefining

Nickel behavior has a significant role in the electrorefining of copper, and although it has been extensively studied from the anode and electrolyte point of view over the past decades, studies on nickel contamination at the cathode are limited. In the current paper, three possible contamination mechanisms—particle entrapment, electrolyte inclusions and co-electrodeposition—were investigated. Copper electrorefining (Cu-ER) was conducted at the laboratory scale, and the cathodes were analyzed by scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS) and flame atomic absorption spectroscopy (AAS). Particle entrapment was studied by adding NiO and Fe2O3 to the system to simulate nickel anode slime, and the experiments were replicated with industrial anode slime material. The possibility of electrolyte entrapment due to nodulation was explored through the addition of graphite to produce nodules on the cathode. Co-electrodeposition was analyzed by experiments that utilized a Hull cell. The results indicate that particle entrapment can occur at the cathode and is a major source of the nickel contamination in Cu-ER, whereas nickel compounds were not shown to promote nodulation. Inclusions of bulk electrolytes within the surface matrix were observed, proving that electrolyte entrapment is possible. As co-electrodeposition of Ni in Cu-ER is thermodynamically unlikely, these experimental results also verify that it does not occur to any significant extent.

EFFECT OF NICKEL AND ITS INSOLUBLE INORGANIC COMPOUNDS ON REPRODUCTIVE FUNCTION OF WHITE RATS

Introduction. The problem of women's health protection in enterprises producing and using nickel and its compounds is particularly relevant, since women make up a significant contingent of workers at some stages of production. Nickel and its compounds are used in the production of high-alloy steels, alloys with copper, chromium, aluminum, as a catalyst in the processes of hydrogenation of fats, in the production of batteries, nickel-plating of metal products. In case of violations of the technological process, labor protection conditions, workers may be exposed to nickel aerosol and its oxides. Purpose. To study the effect of nickel and its insoluble compounds on the reproductive function of white rats. Method of research. The studies were carried out on sexually mature female white rats weighing 180-200 g with a stable estrous cycle lasting 4-6 days. Experimental studies were conducted in accordance with national and international regulatory requirements ensuring humane treatment of animals used in experiments: Directive 2010/63/EU of the European Parliament and of the Council of the European Union of September 22, 2010 on the protection of animals used in scientific purposes, Order of the Ministry of Health of the Russian Federation of 01.04.2016 No. 199n «On approval of the Rules of good laboratory Practice». The industrial conditions for the action of aerosol of insoluble nickel compounds were simulated in a special chamber with an individual intake of aerosol into the breathing zone at a concentration of 0.2 mg / m3 daily for 4 hours during the entire gestation period. The animals were assessed for the dynamics of body weight on the 1st, 8th, 14th and 20th days of pregnancy. On the 20th day of pregnancy, the number of yellow bodies of pregnancy, placentas and fetuses was determined, pre-, post-implantation and total intrauterine death, average length and weight of fetuses, and average placenta weight were calculated. The total number of pregnant females and fetuses was recorded with the subsequent calculation of the number of fetuses per female. Results. The action of an aerosol of insoluble nickel compounds at a concentration of 0.2 mg / m3 in this mode did not lead to a violation of the reproductive function of white rats in all the studied parameters. Conclusion. The experimental data obtained indicate that insoluble nickel compounds at the level of the maximum permissible concentrations for the air of the working area will not pose a risk of developing reproductive health pathology in working women.

Early clinical and laboratory diagnostics of allergodermatoses in electroplating shop workers

Introduction. At the present stage, the occupational pathology of the skin remains one of the significant medical and social problems. In this regard, special attention is paid to the early diagnosis of sensitization to industrial chemical allergens to target occupational allergic diseases. The aim of the study was to study the changes in clinical and laboratory parameters in the formation of allergic skin diseases in workers during nickel plating. Material and methods. Three hundred eighty-nine employees of the machine-building enterprise were examined. The leading group consisted of 214 people exposed to harmful chemical factors of production. Group of intact persons 175 people is represented by employees who do not come into contact with harmful factors of the production environment. The condition of the skin of workers was analyzed. Laboratory studies of oxidative metabolism and immune status were performed according to unified methods. The nickel content in the urine was determined by voltammetry. Results. At the studied enterprise, 38,3% of workers were diagnosed with occupational skin diseases (epidermosis, allergic dermatitis, eczema). In the formation of dermatological morbidity, an increase in the activity of alkaline (ALPn) and acid (ACPn) phosphatase of neutrophils by 1,7-2.2 times and inhibition of succinate dehydrogenase (SDH) and neutrophil myeloperoxidase (MPn) by 1.2-1.5 times relative to the control group was found. On the part of the immune system, there was an activation of the suppressor function of T-lymphocytes (CD8+); B-lymphocytes (CD20+), an increase in the content of immunoglobulins IgG, total IgE, circulating immune complexes by 1.5-2.0 times and a decrease in the levels of immunoglobulins IgA, IgM by 3.0-5.0 times compared to the control. The relationship between the nickel content in the urine of workers and changes in the indicators of ACPn (r = 0.76), MPn (r = -0.87), (CD4+) (r = -0.91), (CD8+) (r = 0,86), general IgE (r = 0.92), indicating the priority role of nickel compounds in the formation of allergodermatoses in workers. Conclusion. The proposed complex of biomarkers aims to detect early the initial forms of allergodermatosis and the formation of risk groups for the timely rehabilitation of electroplating workers.

Assessing risks caused by nickel-based nanomaterials: hazardous factor identification

Nanoparticles of nickel (Ni) and its compounds attract a lot of attention bearing in mind their promising innovative properties allowing their use as catalysts, components in electrical appliances, electronic devices and photonic appliances, and materials used in producing medications, diagnostic preparations, and pesticides. Production volumes of these materials in their nano-form are likely to grow rapidly in the nearest future and it involves greater loads created by these nanomaterials on a human body. And we should remember that Ni and its compounds are highly toxic for humans even in their traditional disperse forms. Their toxicity induces oxidative stress, cellular membranes and mitochondria dysfunction, expression of nuclear transcription factors that are responsible for apoptosis, caspases, as well as proto-oncogenes. Leading role in toxicity of Ni-containing nanomaterials obviously belongs to ions of heavy Ni++ being emitted from them since this heavy metal has pro-oxidant properties and influences enzyme activity and gene expression. Cytotoxic effects produced by Ni-containing nanomaterials were revealed in Model experiments in vitro performed with suing cellular cultures that were morphologically and functionally similar to epithelial cells of respiratory and gastrointestinal tract, liver, kidneys, and nervous system; these materials were able to stimulate oxidant stress, influence expression of apoptosis proteins and nuclear transcription factors, induce apoptosis and necrosis. There are data indicating that Ni-containing nanomaterials can produce malignant transforming effects in vitro. All the above mentioned proves that nickel compounds in their nanoform are a new hazardous factor that requires assessing related risks for workers, consumer, and population in general. Our review focuses on analyzing literature sources on cytotoxicity of Ni-containing nanomaterials and their effects produced on molecular-genetic and cellular levels taken over a period starting from 2011.

Assessing risks caused by nickel-based nanomaterials: hazardous factor identification

Nanoparticles of nickel (Ni) and its compounds attract a lot of attention bearing in mind their promising innovative properties allowing their use as catalysts, components in electrical appliances, electronic devices and photonic appliances, and materials used in producing medications, diagnostic preparations, and pesticides. Production volumes of these materials in their nano-form are likely to grow rapidly in the nearest future and it involves greater loads created by these nanomaterials on a human body. And we should remember that Ni and its compounds are highly toxic for humans even in their traditional disperse forms. Their toxicity induces oxidative stress, cellular membranes and mitochondria dysfunction, expression of nuclear transcription factors that are responsible for apoptosis, caspases, as well as proto-oncogenes. Leading role in toxicity of Ni-containing nanomaterials obviously belongs to ions of heavy Ni++ being emitted from them since this heavy metal has pro-oxidant properties and influences enzyme activity and gene expression. Cytotoxic effects produced by Ni-containing nanomaterials were revealed in Model experiments in vitro performed with suing cellular cultures that were morphologically and functionally similar to epithelial cells of respiratory and gastrointestinal tract, liver, kidneys, and nervous system; these materials were able to stimulate oxidant stress, influence expression of apoptosis proteins and nuclear transcription factors, induce apoptosis and necrosis. There are data indicating that Ni-containing nanomaterials can produce malignant transforming effects in vitro. All the above mentioned proves that nickel compounds in their nanoform are a new hazardous factor that requires assessing related risks for workers, consumer, and population in general. Our review focuses on analyzing literature sources on cytotoxicity of Ni-containing nanomaterials and their effects produced on molecular-genetic and cellular levels taken over a period starting from 2011.