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Letteratura scientifica selezionata sul tema "Copper Spinel"

Autore: Grafiati

Pubblicato: 12 ottobre 2024

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Articoli di riviste sul tema "Copper Spinel"

Białas, Anna, Kamil Rugała, Cezary Czosnek, Grzegorz Mordarski e Jacek Gurgul. "Copper Aluminum Spinels Doped with Cerium as Catalysts for NO Removal". Catalysts 10, n. 12 (28 novembre 2020): 1388. http://dx.doi.org/10.3390/catal10121388.

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Cu-Ce(Mn)-Al oxide catalysts to NO removal in the broad temperature range were synthesized and tested. The precursor of copper aluminium spinel was obtained with the coprecipitation method. By this method, Cu–Al spinels with various amounts of manganese and cerium were synthesized as well. These oxides crystallized in the structure of inverse spinel; however, Ce doping caused the appearance of additional CeO2 phase as determined by XRD. The samples were mesoporous solids with moderate surface area and porosity measured by low temperature sorption of nitrogen. The addition of another metal to Cu–Al spinel caused an increase of activity in selective catalytic reduction of nitrogen oxide with ammonia. The presence of manganese caused the formation of a higher amount of N2O by-product. The catalytic activity increased with the cerium concentration. For the sample with the atomic ratio Ce0.15Cu0.18, ca. 90% of NO conversion was registered between 200 and 350 °C. As examined with XPS spectroscopy, such conversion was attained due to the good dispersion of copper on the catalyst surface. This copper was placed mainly in spinel octahedral positions which enable its easier reduction. The spinel structure causes the presence of cerium as the trivalent cation important in redox cycles with the participation of copper.

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Fan, Fenglan, Lingjuan Wang, Lei Wang, Jinyu Liu e Minghui Wang. "Low-Temperature Selective NO Reduction by CO over Copper-Manganese Oxide Spinels". Catalysts 12, n. 6 (29 maggio 2022): 591. http://dx.doi.org/10.3390/catal12060591.

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Selective catalytic reduction of NO with CO (CO-SCR) has been suggested as an attractive and promising technology for removing NO and CO simultaneously from flue gas. Manganese-copper spinels are a promising CO−SCR material because of the high stability and redox properties of the spinel structure. Here, we synthesized CuxMn3−xO4 spinel by a citrate-based modified pechini method combining CuO and MnOx, controlling the molar Cu/Mn concentrations. All the samples were characterized by SEM, EDX, XRD, TEM, H2−TPR, XPS and nitrogen adsorption measurements. The Cu1.5Mn1.5O4 catalyst exhibits 100% NO conversion and 53.3% CO conversion at 200 °C. The CuxMn3−xO4 catalyst with Cu-O-Mn structure has a high content of high valence Mn, and the high mass transfer characteristics of the foam-like structure together promoted the reaction performance. The CO-SCR catalytic performance of Cu was related to the spinel structure with the high ratio of Mn4+/Mn, the synergistic effect between the two kinds of metal oxides and the multistage porous structure.

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Mandal, Siba Prasad. "Analysis of DC Conductivity and I-V Characterization of Nanocrystalline Copper Ferrite Sample at and above Room Temperature". Materials Science Forum 1103 (25 ottobre 2023): 121–28. http://dx.doi.org/10.4028/p-s3luqw.

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Spinel copper ferrite nanoparticles have wide spread technological applications. Polycrystalline copper ferrite nanoparticles is prepared by sonochemical method. The structural property is investigated by X-ray diffraction study, which reveals cubic spinel structure of copper ferrite NPs with average crystalline size of 20 nm. The temperature variation of DC conductivity of copper ferrite nanoparticles is studied. The conductivity is observed to increase with temperature which implies semiconducting nature of copper ferrite. The Mott study reveals that conduction process is three dimensional in present case. Again, p-n junction formation in the ferrite system is observed from the current voltage (I-V) study. This study further shows that the trap height increases with temperature. Ideality factor with values greater than 1 has been observed in present case.

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Sahu, Sulata K., e Alexandra Navrotsky. "Thermodynamics of copper‐manganese and copper‐iron spinel solid solutions". Journal of the American Ceramic Society 100, n. 8 (22 aprile 2017): 3684–92. http://dx.doi.org/10.1111/jace.14813.

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Ahmed, Awad I., S. E. Samra e S. A. El-Hakam. "Structural and surface aspects of thermally treated copper aluminium mixed hydroxides". Canadian Journal of Chemistry 69, n. 10 (1 ottobre 1991): 1511–15. http://dx.doi.org/10.1139/v91-223.

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CuO–Al2O3 catalysts containing various amounts of copper oxide have been prepared by precipitation. The phase changes were studied by X-ray diffraction. The results obtained revealed that the thermal treatment of solid CuO–Al2O3 at 700 °C produced only crystalline CuO. Heating to 900 °C led to the formation of copper alumina spinel together with unreacted CuO and γ-Al2O3. The spinel content was found to increase with increasing copper content. Nitrogen adsorption–desorption isotherms on the calcined samples have been measured. Surface areas have been calculated and the pore structure analysed. The textural properties of the system were found to depend on both the copper content and the calcination temperature. Key words: CuO, Al2O3 catalysts, structure, surface area, pore structure.

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Othéro de Brito, Vera Lúcia, Stéphanie Alá Cunha, Ana Paula Ribeiro Uchoas, Fabiana Faria de Araújo, Cristina Bormio Nunes e Luis Antonio Genova. "Evaluation of the Sinterability of Copper-Substituted Ferrites by Means of Dilatometric Thermal Analysis". Materials Science Forum 805 (settembre 2014): 254–59. http://dx.doi.org/10.4028/www.scientific.net/msf.805.254.

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Cobalt and cobalt-manganese spinel ferrites have magnetostrictive properties suitable for application in magneto-electric and magneto-mechanical transducers. In this work, copper-substituted ferrites of these compositions were processed by means of the ceramic method and their sinterabilities were evaluated by dilatometric thermal analyses. The results obtained suggest that copper affects the solid-state reactions for the spinel formation and lowers the required sintering temperature for the ferrites. However, the densification obtained with sintering of the copper-substituted ferrites at 950oC for 6h was only 64%, which indicates that further adjustments on the processing route must be made in order to obtain higher densities.

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Flores-Lasluisa, Jhony Xavier, Javier Quílez-Bermejo, Ana Cristina Ramírez-Pérez, Francisco Huerta, Diego Cazorla-Amorós e Emilia Morallón. "Copper-Doped Cobalt Spinel Electrocatalysts Supported on Activated Carbon for Hydrogen Evolution Reaction". Materials 12, n. 8 (20 aprile 2019): 1302. http://dx.doi.org/10.3390/ma12081302.

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The development of electrocatalysts based on the doping of copper over cobalt spinel supported on a microporous activated carbon has been studied. Both copper–cobalt and cobalt spinel nanoparticles were synthesized using a silica-template method. Hybrid materials consisting of an activated carbon (AC), cobalt oxide (Co3O4), and copper-doped cobalt oxide (CuCo2O4) nanoparticles, were obtained by dry mixing technique and evaluated as electrocatalysts in alkaline media for hydrogen evolution reaction. Physical mixtures containing 5, 10, and 20 wt.% of Co3O4 or CuCo2O4 with a highly microporous activated carbon were prepared and characterized by XRD, TEM, XPS, physical adsorption of gases, and electrochemical techniques. The electrochemical tests revealed that the electrodes containing copper as the dopant cation result in a lower overpotential and higher current density for the hydrogen evolution reaction.

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Komova, Oksana V., Valentina I. Simagina, Alena A. Pochtar, Olga A. Bulavchenko, Arcady V. Ishchenko, Galina V. Odegova, Anna M. Gorlova et al. "Catalytic Behavior of Iron-Containing Cubic Spinel in the Hydrolysis and Hydrothermolysis of Ammonia Borane". Materials 14, n. 18 (19 settembre 2021): 5422. http://dx.doi.org/10.3390/ma14185422.

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The paper presents a comparative study of the activity of magnetite (Fe3O4) and copper and cobalt ferrites with the structure of a cubic spinel synthesized by combustion of glycine-nitrate precursors in the reactions of ammonia borane (NH3BH3) hydrolysis and hydrothermolysis. It was shown that the use of copper ferrite in the studied reactions of NH3BH3 dehydrogenation has the advantages of a high catalytic activity and the absence of an induction period in the H2 generation curve due to the activating action of copper on the reduction of iron. Two methods have been proposed to improve catalytic activity of Fe3O4-based systems: (1) replacement of a portion of Fe2+ cations in the spinel by active cations including Cu2+ and (2) preparation of highly dispersed multiphase oxide systems, involving oxide of copper.

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Zhao, B., P. Hayes e E. Jak. "Effects of CaO, Al2O3 and MgO on liquidus temperatures of copper smelting and converting slags under controlled oxygen partial pressures". Journal of Mining and Metallurgy, Section B: Metallurgy 49, n. 2 (2013): 153–59. http://dx.doi.org/10.2298/jmmb120812009z.

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Phase equilibria of silicate slags relevant to the copper smelting/converting operations have been experimentally studied over a wide range of slag compositions, temperatures and atmospheric conditions. Selected systems are of industrial interest and fill the gaps in fundamental information required to systematically characterise and describe copper slag chemistry. The experimental procedures include equilibration of synthetic slag at high temperatures, rapid quenching of resulting phases, and accurate measurement of phase compositions using electron probe X-ray microanalysis (EPMA). The effects of CaO, Al2O3 and MgO on the phase equilibria of this slag system have been experimentally investigated in the temperature range 1200 to 1300 oC and oxygen partial pressures between 10-5 and 10-9 atm. It was found that spinel and silica are major primary phases in the composition range related to copper smelting/converting slags. In addition, olivine, diopside and pyroxene also appear at certain conditions. The presence of CaO, MgO and Al2O3 in the slag increases the spinel liquidus and decreases the silica liquidus. Liquidus temperatures in silica primary phase field are not sensitive to Po2; Liquidus temperatures in spinel primary phase field increase with increasing Po2. At 1300 oC and low Po2, the spinel (Fe2+,Mg2+)O.(Al3+,Fe3+) primary phase field can be replaced by wustite (Fe2+,Mg2+)O.

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Wang, N., M. Chen, Z. Zou, Z. Zhang, Y. Xiao e Y. Yang. "Liquidus and phase equilibria in CaO-Al2O3-FeOx-SiO2 system under intermediate oxygen partial pressure". Journal of Mining and Metallurgy, Section B: Metallurgy 49, n. 2 (2013): 139–44. http://dx.doi.org/10.2298/jmmb120826014w.

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Abstract (sommario):

Phase equilibria of silicate slags relevant to the copper smelting/converting operations have been experimentally studied over a wide range of slag compositions, temperatures and atmospheric conditions. Selected systems are of industrial interest and fill the gaps in fundamental information required to systematically characterise and describe copper slag chemistry. The experimental procedures include equilibration of synthetic slag at high temperatures, rapid quenching of resulting phases, and accurate measurement of phase compositions using electron probe X-ray microanalysis (EPMA). The effects of CaO, Al2O3 and MgO on the phase equilibria of this slag system have been experimentally investigated in the temperature range 1200 to 1300 oC and oxygen partial pressures between 10-5 and 10-9 atm. It was found that spinel and silica are major primary phases in the composition range related to copper smelting/converting slags. In addition, olivine, diopside and pyroxene also appear at certain conditions. The presence of CaO, MgO and Al2O3 in the slag increases the spinel liquidus and decreases the silica liquidus. Liquidus temperatures in silica primary phase field are not sensitive to Po2; Liquidus temperatures in spinel primary phase field increase with increasing Po2. At 1300?C and low Po2, the spinel (Fe2+,Mg2+)O.(Al3+,Fe3+) primary phase field can be replaced by wustite (Fe2+,Mg2+)O.

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Più fonti

Tesi sul tema "Copper Spinel"

Abdelli, Hanen. "Ρrοductiοn phοtοcatalytique de l’hydrοgène à partir de l’acide fοrmique sοus lumière visible : phοtοcatalyseurs à base d’οxyde de cuivre et de fer". Electronic Thesis or Diss., Normandie, 2024. http://www.theses.fr/2024NORMC210.

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Le développement technologique visant à construire une société utilisant l'hydrogène comme moyen d'énergie, avec une faible charge environnementale et un rendement élevé, est nécessaire de toute urgence. Toutefois, l'hydrogène étant inflammable, les problèmes de sécurité liés à son stockage et à son transport limitent son utilisation en tant que combustible. L’utilisation des transporteurs organiques liquides d'hydrogène (TOLHs, ou LOHCs pour Liquid Organic Hydrogen Carriers) présente une alternative très prometteuse. Ils permettent de stocker et de transporter efficacement l'hydrogène avec une faible densité énergétique et volumétrique. A cet égard, l'acide formique est reconnu comme l'un des transporteurs d'hydrogène les plus prometteurs. Dans le cadre de cette thèse, nous nous sommes principalement intéressés à la production photocatalytique de l’hydrogène à partir de l’acide formique sous lumière visible en utilisant des photocatalyseurs à base d’oxyde de Cuivre et de Fer. Ces photocatalyseurs ont montré une très bonne activité et sélectivité pour la déshydrogénation de l’acide formique sous lumière visible à température ambiante et sous flux continu. Les résultats obtenus dans cette thèse donnent non seulement un aperçu des facteurs affectant la réaction mais aussi des perspectives pour améliorer à la fois l’activité des photocatalyseurs et la sélectivité de la déshydrogénation. Par conséquent, les catalyseurs à base de cuivre, connus pour leur stabilité relativement faible dans les procédés en phase liquide, peuvent bien être considérés comme des photocatalyseurs très prometteurs spécifiquement en phase gazeuse/vapeur. Les connaissances fondamentales résultant de ce travail devraient peut avoir un impact significatif sur le développement durable et rentable de la production hautement sélective d'hydrogène à partir de l'acide formique dans des conditions douces
Technological development aimed at building society expending hydrogen as an energy source, with low environmental impact and high efficiency, is urgently needed. However, as hydrogen is flammable, safety issues linked to its storage and transport limit its use as a fuel. The use of liquid organic hydrogen carriers (LOHCs) presents a very promising alternative. They enable an efficient storage and transport of hydrogen at low energy and volumetric densities. In this respect, formic acid is recognized as one of the most promising LOHC. In this thesis, we focused on the photocatalytic production of hydrogen from formic acid, using copper-iron oxide photocatalysts. These photocatalysts showed very good activity and selectivity for the dehydrogenation of formic acid under visible light at room temperature and under continuous flow. The results obtained in this thesis not only provide insight into the factors affecting the reaction, but also offer prospects for improving both photocatalyst activity and dehydrogenation selectivity. As a result, copper-based catalysts, known for their relatively low stability in liquid-phase processes, may well be considered highly promising photocatalysts specifically in the gas/vapor phase. The fundamental insights resulting from this work should have a significant impact on the sustainable and cost-effective development of highly selective hydrogen production from formic acid under mild conditions

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Nzaba, Sarre Kadia Myra. "Lithium manganese oxide modified with copper-gold nanocomposite cladding- a potential novel cathode material for spinel type lithium-ion batteries". University of the Western Cape, 2014. http://hdl.handle.net/11394/4444.

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>Magister Scientiae - MSc
Spinel lithium manganese oxide (LiMn2O4), for its low cost, easy preparation and nontoxicity, is regarded as a promising cathode material for lithium-ion batteries. However, a key problem prohibiting it from large scale commercialization is its severe capacity fading during cycling. The improvement of electrochemical cycling stability is greatly attributed to the suppression of Jahn-Teller distortion (Robertson et al., 1997) at the surface of the spinel LiMn2O4 particles. These side reactions result in Mn2+ dissolution mainly at the surface of the cathode during cycling, therefore surface modification of the cathode is deemed an effective way to reduce side reactions. The utilization of a nanocomposite which comprises of metallic Cu and Au were of interest because their oxidation gives rise to a variety of catalytically active configurations which advances the electrochemical property of Li-ion battery. In this research study, an experimental strategy based on doping the LiMn2O4 with small amounts of Cu-Au nanocomposite cations for substituting the Mn3+ ions, responsible for disproportionation, was employed in order to increase conductivity, improve structural stability and cycle life during successive charge and discharge cycles. The spinel cathode material was synthesized by coprecipitation method from a reaction of lithium hydroxide and manganese acetate using 1:2 ratio. The Cu-Au nanocomposite was synthesized via a chemical reduction method using copper acetate and gold acetate in a 1:3 ratio. Powder samples of LiMxMn2O4 (M = Cu-Au nanocomposite) was prepared from a mixture of stoichiometric amounts of Cu-Au nanocomposite and LiMn2O4 precursor. The novel LiMxMn2O4 material has a larger surface area which increases the Li+ diffusion coefficient and reduces the volumetric changes and lattice stresses caused by repeated Li+ insertion and expulsion. Structural and morphological sample analysis revealed that the modified cathode material have good crystallinity and well dispersed particles. These results corroborated the electrochemical behaviour of LiMxMn2O4 examined by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The diffusion coefficients for LiMn2O4 and LiMxMn2-xO4 obtained are 1.90 x10-3 cm2 / s and 6.09 x10-3 cm2 / s respectively which proved that the Cu-Au nanocomposite with energy band gap of 2.28 eV, effectively improved the electrochemical property. The charge / discharge value obtained from integrating the area under the curve of the oxidation peak and reduction peak for LiMxMn2-xO4 was 263.16 and 153.61 mAh / g compared to 239.16 mAh / g and 120 mAh / g for LiMn2O4. It is demonstrated that the presence of Cu-Au nanocomposite reduced side reactions and effectively improved the electrochemical performance of LiMn2O4.

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Dörfelt, Christoph [Verfasser], Klaus [Akademischer Betreuer] Köhler, Moniek [Gutachter] Tromp, Klaus [Gutachter] Köhler e Kai-Olaf [Gutachter] Hinrichsen. "Synthesis, Reaction and Deactivation Mechanisms of Copper Aluminate Spinel Hydrogenation Catalysts / Christoph Dörfelt ; Gutachter: Moniek Tromp, Klaus Köhler, Kai-Olaf Hinrichsen ; Betreuer: Klaus Köhler". München : Universitätsbibliothek der TU München, 2018. http://d-nb.info/1210643995/34.

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Chauvin, Camille. "Caracterisation d'oxydes de zinc et de catalyseurs de synthese du methanol cu-znal::(2)o::(4) : etude par spectroscopie infrarouge des sites d'adsorption et des mecanismes reactionnels". Caen, 1987. http://www.theses.fr/1987CAEN2017.

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Jones, Page. "Enzymatic and proteomic analysis of spinal cord in a G93A ALS mouse model". Thesis, Birmingham, Ala. : University of Alabama at Birmingham, 2008. https://www.mhsl.uab.edu/dt/2008r/jonesp.pdf.

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Chen, Meng-Hsien. "Investigation of copper and cadmium in the food chain of three-spined stickleback populations, Gasterosteus aculeatus L., in the River Wandle, UK". Thesis, King's College London (University of London), 1992. https://kclpure.kcl.ac.uk/portal/en/theses/investigation-of-copper-and-cadmium-in-the-food-chain-of-threespined-stickleback-populations-gasterosteus-aculeatus-l-in-the-river-wandle-uk(2efa8185-45e3-46f8-ba3d-84a434eb0f7b).html.

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Chapman, Kimberly K., Michael J. Benton, Ralph O. Brinkhurst e Phillip R. Scheuerman. "Use of the Aquatic Oligochaetes Lumbriculus Variegatus and Tubifex Tubifex for Assessing the Toxicity of Copper and Cadmium in Spiked-Sediment Toxicity Bioassay". Digital Commons @ East Tennessee State University, 1999. https://dc.etsu.edu/etsu-works/2881.

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A sediment toxicity test using the freshwater oligochaetes Lumbriculus variegatus and Tubifex tubifex was performed. We evaluated acute and chronic toxicity affects of copper and cadmium on reproduction in both species and the bioaccumulation of both metals by L. variegatus using artificial sediment. L. variegatus bioconcentrated copper 22‐fold and cadmium 16‐fold after a 14‐day exposure to spiked artificial sediments with 0.02% organic content. The EC50 for T. tubifex varied depending upon endpoint from 2.7 to 2.8 mg/L for cadmium and from 8.4 to 8.9 mg/L for copper. The EC50 for L. variegatus was 2.2 mg/L for cadmium and 3.9 mg/L for copper. Based on these results, L. variegatus appears to be more sensitive to metal toxicity in artificial sediments than T. tubifex.

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Кухарук, Юрій Ігорович, e Yuriy Kukharuk. "Моделювання динамічних характеристик шпиндельного вузла спеціального токарно-копіювального багаторізцевого напівавтомата з ЧПК". Master's thesis, Тернопільський національний технічний університет імені Івана Пулюя, 2018. http://elartu.tntu.edu.ua/handle/lib/27293.

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Роботу виконано на кафедрі конструювання верстатів, інструментів та машин Тернопільського національного технічного університету імені Івана Пулюя Міністерства освіти і науки України
В дипломній роботі здійснено розрахунок та конструювання основних виконавчих вузлів спеціального токарно-копіювального напівавтомата, моделювання динамічних характеристик шпиндельного вузла.
In the thesis the calculation and design of the main executive units of a special turning-copier semiautomatic lathe, modeling of dynamic characteristics of the spindle node is carried out.
Вступ; Перший розділ "загальний розділ "; Другий розділ "Оптимізація схеми формоутворення на проектованому верстаті"; Третій розділ "Оптимізація компоновочної схеми проектованого верстата" ; Четвертий розділ "Вибір та обґрунтування вихідних даних на розробку проектуверстатного обладнання"; П’ятий розділ "Проектування конструкції верстатного обладнання (науково-дослідна частина)"; Шостий розділ "Обґрунтування економічної ефектив-ності"; Сьомий розділ "Охорона праці та безпека в надзвичайних ситуаціях"; Восьмий розділ "Екологія" ; Дев’ятий розділ «спеціальний розділ. САПР» ; Висновки

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Pereira, Hugo Borges. "Avaliação de aditivos para remoção catalítica de SOx em unidades de fcc". Universidade do Estado do Rio de Janeiro, 2007. http://www.bdtd.uerj.br/tde_busca/arquivo.php?codArquivo=7257.

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Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro
Os óxidos de enxofre (SOx) são um dos maiores poluentes atmosféricos e um dos precursores da chuva ácida. Um levantamento feito na Petrobrás mostrou que cerca de 17% dos SOx emitidos numa refinaria são oriundos do processo de FCC. Com o avanço dos controles ambientais, traduzido numa legislação mais restritiva, a técnica de incorporação de aditivos para remoção de SOx em UFCCs apresenta-se como a alternativa de menor custo frente outras tecnologias de abate das emissões de SOx. No presente trabalho, foram estudados aditivos constituídos por compostos derivados de hidrotalcitas com a substituição parcial do magnésio e do alumínio por cobre e/ou manganês, sendo estes impregnados ou não por dióxido de cério. Estes aditivos foram submetidos a testes de desempenho em uma unidade multi-propósito acoplada a um micro-GC/TCD. Em todos os testes, a corrente gasosa para a etapa de adsorção oxidativa foi de 1700 ppm de SO2 e 1,5% O2 em He e, para a etapa de regeneração, 30% H2/He. No primeiro conjunto de testes, realizou-se uma adsorção a 720C de 10 min e regeneração com um patamar a 530C, seguido de um TPR até 800C. Observou-se que as amostras impregnadas com cério apresentaram o melhor desempenho na remoção de SO2, indicando que o cério pode ter um papel de promotor da oxidação de SO2 a SO3. Os resultados do TPR mostram que as amostras com cério e com manganês parecem apresentar menores temperaturas de redução dos sulfatos, apesar das maiores liberações de H2S serem identificadas nas amostras com cobre. No segundo conjunto de testes, a adsorção foi a 720C durante 35 min e a regeneração a 650C por 5 minutos em um patamar de 5 minutos, seguida de um TPR até 800C. Para os tempos de sulfatação curtos (5 e 10 min), os resultados confirmaram o efeito positivo que a incorporação de CeO2 apresenta sobre a adsorção oxidativa do SO2. Todavia, para tempos de reação maiores (35 min), não se observou uma correlação clara entre a composição química do catalisador e a quantidade total de SOx removida. Os aditivos foram ainda testados em ciclos de reação-regeneração em condições equivalentes ao segundo conjunto de testes descrito. De um modo geral, os aditivos que contêm cobre têm uma vida útil superior aos demais, possivelmente, pelo fato do cobre ter importante papel na regeneração do aditivo
The sulfur dioxide emissions are one of the most atmospheric pollutant and precursor of acid rain. A survey carried out by Petrobras shows that around 17% of the SOx emissions of its refineries derive from the FCC process. In recent years, the strengthening of environmental controls with more restrictive legislation turns the incorporation of additives for SOx removal into a low-cost alternative technique compared with other technologies of SOx abatement. The purpose of this work is to study additives composed by derivated hydrotalcite compounds with partial substitution of magnesium and aluminium for copper and/or manganese, and with or without dioxide cerium impregnation. The performance of these additives has been tested in a multi-proposal unit coupled with a micro-GC/TCD. In all the tests it was used a gas stream of 1700 ppm of SO2 and 1,5% O2 in He for the oxidative adsorption step and for the regeneration step a 30% H2 in He stream. In the first test, it was carried out an adsoprtion step at 720C for 10 minutes and a regeneration step at a 530C level, flollowed by an TPR until 800C. The cerium dioxide impregnated samples showed a better result for SO2 removal, which implies cerium may play a role as catalyst for SO2 to SO3 oxidation. The TPR results show cerium and manganese may diminish the temperature of sulfates reduction, besides copper samples releases more H2S gases. In the second test, the adsorption step was carry out at 720C for 35 minutes and the regeneration step at 650C for 5 minutes folloewd by a TPR until 800C. In short times reaction (5 or 10 min) the results confirm the positive effect of cerium in the SO2 oxidantion adsorption. However, for longer time reaction (35 min), it cant be observed a relationship between chemical composition of the aditive and the total amount of SOx removed. Additives were still tested in reaction-regeneration cycles in the same conditions of the second test described above. In general, the additives without copper in their composition has a life time minor than that with copper; possibly, because copper plays an important role in the additive regeneration

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Residori, Sara. "FABRICATION AND CHARACTERIZATION OF 3D PRINTED METALLIC OR NON-METALLIC GRAPHENE COMPOSITES". Doctoral thesis, Università degli studi di Trento, 2022. https://hdl.handle.net/11572/355324.

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Nature develops several materials with remarkable functional properties composed of comparatively simple base substances. Biological materials are often composites, which optime the conformation to their function. On the other hand, synthetic materials are designed a priori, structuring them according to the performance to be achieved. 3D printing manufacturing is the most direct method for specific component production and earmarks the sample with material and geometry designed ad-hoc for a defined purpose, starting from a biomimetic approach to functional structures. The technique has the advantage of being quick, accurate, and with a limited waste of materials. The sample printing occurs through the deposition of material layer by layer. Furthermore, the material is often a composite, which matches the characteristics of components with different geometry and properties, achieving better mechanical and physical performances. This thesis analyses the mechanics of natural and custom-made composites: the spider body and the manufacturing of metallic and non-metallic graphene composites. The spider body is investigated in different sections of the exoskeleton and specifically the fangs. The study involves the mechanical characterization of the single components by the nanoindentation technique, with a special focus on the hardness and Young's modulus. The experimental results were mapped, purposing to present an accurate comparison of the mechanical properties of the spider body. The different stiffness of components is due to the tuning of the same basic material (the cuticle, i.e. mainly composed of chitin) for achieving different mechanical functions, which have improved the animal adaptation to specific evolutive requirements. The synthetic composites, suitable for 3D printing fabrication, are metallic and non-metallic matrices combined with carbon-based fillers. Non-metallic graphene composites are multiscale compounds. Specifically, the material is a blend of acrylonitrile-butadiene-styrene (ABS) matrix and different percentages of micro-carbon fibers (MCF). In the second step, nanoscale filler of carbon nanotubes (CNT) or graphene nanoplatelets (GNP) are added to the base mixture. The production process of composite materials followed a specific protocol for the optimal procedure and the machine parameters, as also foreseen in the literature. This method allowed the control over the percentages of the different materials to be adopted and ensured a homogeneous distribution of fillers in the plastic matrix. Multiscale compounds provide the basic materials for the extrusion of fused filaments, suitable for 3D printing of the samples. The composites were tested in the configuration of compression moulded sheets, as reference tests, and also in the corresponding 3D printed specimens. The addition of the micro-filler inside the ABS matrix caused a notable increment in stiffness and a slight increase in strength, with a significant reduction in deformation at the break. Concurrently, the addition of nanofillers was very effective in improving electrical conductivity compared to pure ABS and micro-composites, even at the lowest filler content. Composites with GNP as a nano-filler had a good impact on the stiffness of the materials, while the electrical conductivity of the composites is favoured by the presence of CNTs. Moreover, the extrusion of the filament and the print of fused filament fabrication led to the creation of voids within the structure, causing a significant loss of mechanical properties and a slight improvement in the electrical conductivity of the multiscale moulded composites. The final aim of this work is the identification of 3D-printed multiscale composites capable of the best matching of mechanical and electrical properties among the different compounds proposed. Since structures with metallic matrix and high mechanical performances are suitable for aerospace and automotive industry applications, metallic graphene composites are studied in the additive manufacturing sector. A comprehensive study of the mechanical and electrical properties of an innovative copper-graphene oxide composite (Cu-GO) was developed in collaboration with Fondazione E. Amaldi, in Rome. An extensive survey campaign on the working conditions was developed, leading to the definition of an optimal protocol of printing parameters for obtaining the samples with the highest density. The composite powders were prepared following two different routes to disperse the nanofiller into Cu matrix and, afterward, were processed by selective laser melting (SLM) technique. Analyses of the morphology, macroscopic and microscopic structure, and degree of oxidation of the printed samples were performed. Samples prepared followed the mechanical mixing procedure showed a better response to the 3D printing process in all tests. The mechanical characterization has instead provided a clear increase in the resistance of the material prepared with the ultrasonicated bath method, despite the greater porosity of specimens. The interesting comparison obtained between samples from different routes highlights the influence of powder preparation and working conditions on the printing results. We hope that the research could be useful to investigate in detail the potential applications suitable for composites in different technological fields and stimulate further comparative analysis.

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Sara, Compton, e Western Ecological Research Center (Geological Survey), a cura di. Post-fire treatment monitoring of critical habitat for the California red-legged frog (Rana aurora draytonii) and unarmored three-spine stickleback (Gasterosteus aculeatus williamsoni) in San Francisquito Canyon following the Copper Fire: Final report. Sacramento, Calif: U.S. Dept. of the Interior, U.S. Geological Survey, Western Ecological Research Center, 2003.

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Sara, Compton, Western Ecological Research Center (Geological Survey) e Angeles National Forest (Calif.), a cura di. Post-fire treatment monitoring of critical habitat for the California red-legged frog (Rana aurora draytonii) and unarmored three-spined stickleback (Gasterosteus aculeatus williamsoni) in San Francisquito Canyon following the Copper Fire: Final report. Sacramento, Calif: U.S. Geological Survey, Western Ecological Research Center, 2003.

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Spider Mcdrew and the Egyptians: Band 12/Copper. HarperCollins Publishers Limited, 2020.

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Spider Mcdrew and the Egyptians: Band 12/Copper. HarperCollins Publishers Limited, 2020.

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Sherman, S. Murray, e W. Martin Usrey. Exploring Thalamocortical Interactions. Oxford University Press, 2021. http://dx.doi.org/10.1093/med/9780197503874.001.0001.

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The thalamus and cerebral cortex are active and necessary partners in the processing of signals essential for sensory, motor, and cognitive functions. This partnership is absolute, as neither the thalamus nor the cortex can be understood in any meaningful way in isolation from the other. This book provides readers with fundamental knowledge about the cells and circuits that mediate thalamocortical interactions and then explores new ideas that often challenge conventional understanding. Some of the major themes emphasized throughout the book include the need for a proper classification of thalamocortical and corticothalamic circuits, the role of spike timing for thalamocortical and corticothalamic communication and the mechanisms for modulating spike timing, the organization and function of corticothalamic feedback projections, the role of higher order thalamic nuclei in cortico-cortical communication and cortical functioning, attentional modulation of thalamocortical interactions, and a rethinking of efference copies and distinguishing neural signals as sensory versus motor. Importantly, to encourage readers to think beyond the material and views provided throughout the book, each chapter closes with a section on “Some Outstanding Questions” to stimulate creative approaches to increase our understanding of thalamocortical interactions.

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Stewart, S. J., R. C. Mercader, G. Punte, J. Desimoni, G. Cernicchiaro e R. B. Scorzelli. "Shifting the Superparamagnetic Limit of Nanosized Copper Iron Spinel". In ICAME 2003, 89–95. Dordrecht: Springer Netherlands, 2004. http://dx.doi.org/10.1007/978-1-4020-2852-6_15.

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Sun, Zhihao, Srikanth Gopalan, Uday B. Pal e Soumendra N. Basu. "Electrophoretically Deposited Copper Manganese Spinel Coatings for Prevention of Chromium Poisoning in Solid Oxide Fuel Cells". In Energy Technology 2019, 265–72. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-06209-5_27.

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Eltorai, Ibrahim M. "Copper Deficiency". In Rare Diseases and Syndromes of the Spinal Cord, 97–99. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-45147-3_32.

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Fukushima, Jun, Hirotsugu Takizawa e Yamato Hayashi. "Synthesis of Copper Spinels by Microwave Irradiation". In Processing and Properties of Advanced Ceramics and Composites VII, 33–41. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2015. http://dx.doi.org/10.1002/9781119183860.ch4.

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Ovcharenko, Victor, e Elena Bagryanskaya. "Breathing Crystals from Copper Nitroxyl Complexes". In Spin-Crossover Materials, 239–80. Oxford, UK: John Wiley & Sons Ltd, 2013. http://dx.doi.org/10.1002/9781118519301.ch9.

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Shubham Rajput, Shubham x., e Navneet Kaur. "SPINEL MAGNETIC COBALTITES FOR THE APPLICATIONS AS SUPERCAPACITORS". In Futuristic Trends in Physical Sciences Volume 2 Book 14, 126–37. Iterative International Publishers, Selfypage Developers Pvt Ltd, 2023. http://dx.doi.org/10.58532/v2bs14p2ch3.

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Transition metal oxides (TMOs) have gained enormous heed in the last decades with their ability to deliver high capacitance. Importunity of futuristic, economical, and eco-friendly energy storage devices with more power/energy densities have increased outstanding interest in inventing new materials that boost performance to fulfill the energy requirements of modern society. Spinel Cobaltite (AB2O4), A, and B for tetrahedral and octahedral configurations of oxygen to form a closed packing of the cubic lattice. Spinel Structure of Cobaltites The physical and chemical properties of cobaltites depend upon their chemical composition and microstructural characteristics, which further depend on the synthesis methods with which they have been synthesized. The methods often include solgel, hydrothermal, electrospinning, and chemical processes. The different cobaltites with different chemical compositions are Co3O4[Tricobalt tetra oxide(CCO)], FeCo2O4[Iron cobaltite(FCO)], CuCo2O4[Copper cobaltite(CuCO)], NiCo2O4[Nickel cobaltite(NCO)], and ZnCo2O4[Zinc Cobaltite(ZCO)]. The Iron Cobaltite was found to exhibit ferromagnetic behavior at room temperature. The Co3O4 nanorods exhibit ultra capacitance of 281 Fg-1 . The FeCo2O4 microspheres nanosheets, nanoflakes, and nanofibers, exhibit ultra capacitance of 231.5 Fg-1 , 339 Fg-1 , 433 Fg-1 , 165 Fg-1 respectively. Also, the ZnCo2O4 nanowires show a value of about 1400 Fg-1 . The nickel cobaltite nanosheets and Copper cobaltite show the most prominent supercapacitive behavior having values of 2282 Fg-1 and 3080 Fg

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Kumar, K. Elaya, Ayyar Manikandan, V. Sathana, S. Muthulingam, M. Maria Julie, R. Thilak Kumar, A. Dinesh et al. "Impact of the rare earth elements doping on the copper ferrite spinel magnetic nanoparticles". In Magnetic Nanoparticles and Polymer Nanocomposites, 373–402. Elsevier, 2024. http://dx.doi.org/10.1016/b978-0-323-85748-2.00014-1.

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Mehak, Rajkumar P. Thummer, Lalit M. Pandey e T. S. Srivatsan. "Engineered Iron-Oxide Based Nanomaterials for Magnetic Hyperthermia". In Advanced Materials for Emerging Applications (Innovations, Improvements, Inclusion and Impact), 440–63. BENTHAM SCIENCE PUBLISHERS, 2024. http://dx.doi.org/10.2174/9789815196771124010017.

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Ferrite nanomaterials are extensively studied for their use in the biomedical field primarily because of their tunable magnetic properties and biocompatibility. The use of magnetic nanomaterials, particularly the iron-based nanoparticles, for hyperthermia treatment is one of the emerging applications. However, there are practical constraints on the overall applicability of pure iron-oxide nanoparticles (IONPs) for hyperthermia treatment. In this regard, doping foreign metal ions in the crystal lattice of pure iron-oxide nanoparticles (IONPs) possessing a spinel or inversespinel structure remains to be the simplest approach for the purpose of improving the desired properties. Doping other metal ions into the iron-oxide nanoparticles (IONPs) causes strain in the crystal lattice and is responsible for engineering the structural properties and magnetic properties. Various elements, such as the rare-earth (RE) metals, especially the lanthanides [Yttrium, Gadolinium and Europium], the transition metals [manganese, cobalt, nickel and zinc], and other metals [gold, silver, calcium, titanium, copper and magnesium] are being investigated for their potential to serve as dopants. The divalent transition metals [manganese, cobalt and nickel] doped ironoxide nanoparticles possess highly improved magnetic properties. Incorporating trivalent ions of lanthanides improves the structural properties, magnetic properties, and dielectric properties of the iron-oxide nanoparticles (IONPs). Moreover, doping with zinc, gold and silver imparts the ion-oxide nanoparticles (IONPs) with antibacterial properties while concurrently tuning their structural properties and magnetic outputs.

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John Jebarathinam, N., M. Eswaramoorthy e V. Krishnasamy. "Hydrogenation of nitrobenzene over copper containing spinels". In Recent Advances In Basic and Applied Aspects of Industrial Catalysis, Proceedings of 13th National Symposium and Silver Jubilee Symposium of Catalysis of India, 1039–43. Elsevier, 1998. http://dx.doi.org/10.1016/s0167-2991(98)80393-5.

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Martin Usrey, W., e S. Murray Sherman. "Corticothalamic Circuits Linking Sensation and Action". In Exploring Thalamocortical Interactions, 161–80. Oxford University Press, 2021. http://dx.doi.org/10.1093/med/9780197503874.003.0013.

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Anatomical data show that most or all driving inputs to thalamus arrive via branching axons, with many targets of the extrathalamic branches being motor centers in the brainstem and/or spinal cord. The interpretation of this is that the messages sent to thalamus for relay are exact copies of messages intended to create and/or influence a motor action. Such a copy can be regarded as an efference copy. This leads to the speculation that one of the differences in the messages sent via direct and transthalamic corticocortical pathways is that the latter can serve as efference copies to inform the target cortical areas of a motor message sent out by the afferent area. It is also suggested from an evolutionary perspective that efference copies exist at multiple levels—spinal, brainstem, and cortical—and that this idea implies that the central nervous system is challenged to deal effectively with all of these efference copies; how it does so remains to be determined.

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Atti di convegni sul tema "Copper Spinel"

Vergote, O., I. Bellemans, K. Verbeken e A. Van den Bulck. "Effect of solid particle size on the viscosity of a secondary copper smelting slag". In 12th International Conference of Molten Slags, Fluxes and Salts (MOLTEN 2024) Proceedings, 149–57. Australasian Institute of Mining and Metallurgy (AusIMM), 2024. http://dx.doi.org/10.62053/zigo4105.

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Viscosity is one of the most important physicochemical properties during pyrometallurgical operations. In the sub-liquidus regime, an important factor is the presence of suspended solid particles, yet its influence is not well-described in earlier literature, despite the significance of this factor. This project aims to determine the influence of spinel particles (Zn(Al,Fe)2O4) on the rheology of a multiphase synthetic PbO-SiO2-ZnO-Fe2O3-CaO-Al2O3 slag system. Three data sets with a well-controlled methodology and three different spinel sizes (small (13 µm), medium (34 µm) and large particles (76 µm)) were published previously, using a custom-built high-temperature rheometer. This study presents an additional data set of slag viscosity measurements, performed using a different apparatus, the Anton Paar FRS 1800, to verify the consistency of the earlier determined viscosity behaviour. Within this data set, no consistent trend could be found between the predicted wt per cent spinel and the relative viscosity. Therefore, additional quenching experiments were conducted to identify the morphology and experimentally determined volume fraction of the spinel particles in the slag. These measurements revealed a difference in spinel size across the samples and corresponding viscosity behaviour, emphasizing the importance of spinel particle size on slag viscosity. Once the spinel size was taken into account, consistent viscosity results (relative apparent viscosity and flow index) were observed across the two devices. This study confirms that, once all parameters affecting slag viscosity are considered, the viscosity behaviour of a heterogeneous slag can be uniquely determined. The resulting optimised slag viscosity models can be used to predict viscosity before processing, addressing relevant phenomena such as slag tapping, slag foaming and copper droplet settlement.

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Pavlikov, A. Y., S. V. Saikova, D. I. Nemkova e D. V. Karpov. "THE STUDIES OF STRUCTURAL AND MAGNETIC PROPERTIES OF COPPER FERRITE NANOPARTICLES". In XVI INTERNATIONAL CONFERENCE "METALLURGY OF NON-FERROUS, RARE AND NOBLE METALS" named after corresponding member of the RAS Gennady Leonidovich PASHKOVA. Krasnoyarsk Science and Technology City Hall, 2023. http://dx.doi.org/10.47813/sfu.mnfrpm.2023.318-327.

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Due to their high electrical resistivity and excellent magnetic properties, spinel ferrites are excellent candidates for modern technological applications. Copper ferrite nanoparticles (NPs) are used in biomedicine (drug delivery, magnetic resonance imaging, magnetic cell separation, and DNA extraction). They also have various technological applications such as energy storage devices, magnetic storage media, and spintronic and electromagnetic devices).

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R, Anjana, Vishnu Narayanan V, Raguram T e Rajni K.S. "Influence of Metal Ions (Cu, Ni, Zn) Substituted Cobalt Ferrite Nanoparticles Synthesized by Sol-Gel Auto Combustion Method for Magnetic Application". In The Second National Conference on Emerging Materials for Sustainable Future, 150–56. Asian Research Association, 2024. http://dx.doi.org/10.54392/ara24117.

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The impact of metal ion substitution on the characteristics of cobalt ferrite nanoparticles is investigated in this work. Sol-gel auto-combustion was used to insert copper (Cu), nickel (Ni), and zinc (Zn) into the spinel lattice. The goal of the study is to comprehend the effects of these substitutions (CuCoFe, NiCoFe, and ZnCoFe) on the magnetic, spectral, and structural properties of the resultant nanoparticles. For every synthetic sample, the successful development of a cubic spinel phase has been confirmed by X-ray diffraction examination. The estimated crystallographic size is roughly 25 nm. The spinel structure's octahedral and tetrahedral sites exhibit metal-oxygen vibrations, as shown by a peak seen at 433 cm⁻³ using Fourier Transform Infrared (FTIR) spectroscopy. Cobalt ferrite nanoparticles replaced with Cu and Ni exhibit well-defined ferromagnetic behavior as revealed by magnetic characterisation. The Zn-substituted sample, on the other hand, displays a paramagnetic hysteresis loop. These findings, along with the results of the other characterization methods, strongly imply that copper, nickel, and zinc have successfully replaced cobalt ions in the octahedral positions of the cobalt ferrite lattice.

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Sarıtaş, Sevda, Betul Cevız Sakar, Erdal Turgut, Mutlu Kundakcı e Muhammet Yıldırım. "Copper-substituted spinel zinc ferrite and magnesium ferrite thin films grown by spray pyrolysis". In SolarPACES 2017: International Conference on Concentrating Solar Power and Chemical Energy Systems. Author(s), 2018. http://dx.doi.org/10.1063/1.5078903.

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Yu, Zexin, Meimei Liu, Michel Moliere, Hanlin Liao, Hatem Moussa, Raphaël Schneider e Weize Wang. "Spinel Copper Ferrite and Zinc Ferrite Films Synthesized via Solution Precursor Plasma Spray Process for Functional Applications". In ITSC2018, a cura di F. Azarmi, K. Balani, H. Li, T. Eden, K. Shinoda, T. Hussain, F. L. Toma, Y. C. Lau e J. Veilleux. ASM International, 2018. http://dx.doi.org/10.31399/asm.cp.itsc2018p0627.

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Abstract Binary spinel-type metal oxides (AB2O4) semiconductors, including ferrites (AFe2O4), are attractive photocatalysts thanks to their excellent visible light response and good photochemical activity and stability for the photodegradation of organic pollutants. Currently, their synthesis proceeds via conventional chemical routes that follow rather tedious protocols and the final preparations consist in nano-powders, a form that is not exempt of EHS (Environment, health and safety) risks along their handling. From an industry perspective, it is desirable to dispose of an efficient and preferably simple synthesis route capable to produce photocatalytic preparations in a non-dispersible form, for instance in the form of robust films attached on solid substrates. We report herein a single-step method based on the Solution Precursor Plasma Spray (SPPS) process that enables the preparation of promisingly active ferrite-based photocatalytic films, namely CuFe2O4 and ZnFe2O4. We have investigated various types of precursor solutions, including the atomic A/Fe ratios, solvent type and solute concentration, and studied the evolution of the phase composition of the resultant CuFe2O4 and ZnFe2O4 films by XRD. The corresponding surface morphologies and energy bandgaps were also studied by SEM and UV-Vis spectroscopy, respectively. Then the photocatalytic activities of the selective ferrite films were evaluated through the degradation of aqueous solutions of the Orange II dye under different light irradiations. The results of the overall work also revealed that SPPS process represents a fast, one-step, versatile alternative compared to conventional multi-step processes, which is suitable for preparing complex composition metal oxide film-formed photocatalyst.

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Golden, Steve, Zahra Nazarpoor, Maxime Launois, Ru-Fen Liu e Pardha Maram. "Development of Non-Copper Advanced Spinel Mixed Metal Oxides for Zero-Precious Metal and Ultra-Low Precious Metal Next-Generation TWC". In SAE 2016 World Congress and Exhibition. 400 Commonwealth Drive, Warrendale, PA, United States: SAE International, 2016. http://dx.doi.org/10.4271/2016-01-0933.

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Д.В., Абрамов,, Данилов, О.В. e Хорьков, К.С. "TURKISH CERAMICS OF THE XVI-XVII CENTURIES FROM EXCAVATIONS IN MUROM: RAMAN ANALYSIS OF GLAZES AND PIGMENTS". In Археология Владимиро-Суздальской земли. Crossref, 2021. http://dx.doi.org/10.25681/iaras.2021.978-5-94375-365-7.162-173.

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В статье представлены результаты рамановского анализа химического и структурного состава фрагментов импортного глазурованного кувшина из раскопок в Муроме. Исследованы кроющая глазурь и пигменты, использованные при его росписи. Полученные результаты позволяют объективно определить место и время изготовления находок (Изник, Турция, XVI в.). Выявлены характерные особенности такой керамики, которые могут позволить атрибутировать находки ее фрагментов на основе материалов, использованных в красках: уваровита в оливково-зеленом линейном орнаменте, силиката кобальта со структурой оливина в синем фоне, окрашенного карбонатом меди стекла (smalt) в бирюзовых элементах росписи, аморфного углерода и хромита железа со структурой шпинели в черных линиях. Белый ангоб содержит переходные структуры, образовавшиеся при обжиге керамики. Их наличие позволяет оценить температурный режим обработки изделий в средневековых мастерских Изника. The article presents the results of Raman analysis of the chemical and structural composition of fragments of an imported glazed jug from excavations in Murom. The covering glaze and pigments that were used in its painting have been investigated. The obtained results make it possible to objectively determine the place and time of making the finds (Iznik, Turkey, 16th century). The revealed characteristic features of such ceramics can help to attribute the finds of its fragments based on the materials used in the paints. There are uvarovite in olive green linear ornament, cobalt silicate with olivine structure in a blue background, smalt colored with copper carbonate in turquoise elements of painting, amorphous carbon and iron chromite with a spinel structure in black lines. White engobe contains transitional structures formed during ceramic firing. Their presence makes it possible to estimate the temperature conditions of a products processing in Iznik’s medieval workshops.

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Assunção, Darah Fontes da Silva, Bruno Pissolati Mattos Gonzaga, Gabriel Chung, Marcelle Sanjuan Ganem Prado, Matheus Kohama Kormanski, Renan Brandão Rambaldi Cavalheiro, Francisco Tomaz Meneses de Oliveira e Rubens José Gagliardi. "Subacute combined degeneration of the spinal cord in copper deficiency: case report". In XIV Congresso Paulista de Neurologia. Zeppelini Editorial e Comunicação, 2023. http://dx.doi.org/10.5327/1516-3180.141s1.513.

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Introduction: Copper deficiency is a rare disease that can present with a wide variety of symptoms, with myelopathy as the most common neurological presentation. The clinical features are characterized by sensory ataxia, spasticity and sensory-motor neuropathy. The risk factor that has the most impact is previous gastrointestinal surgery, but a large part of cases remain without a determined cause. The aim to present a case of combined subacute medullary degeneration secondary to copper deficiency with good response to treatment by reviewing the patient’s medical record. Case report: Male, 47-year-old, with no pathological history or previous surgeries. His symptoms started 12 days after coronavirus disease 2019 infection, as paresthesias in the lower limbs, urinary retention and progressive weakness. Imaging exams showed longitudinally extensive cervical and thoracic medullary injury compromising posterior and posterolateral regions, without contrast uptake. Complementary investigation demonstrated low serum copper. After oral and parenteral copper supplementation, the patient evolved with significant improvement. The etiological investigation of copper deficiency remains undetermined until the moment. Discussion: Myelopathy secondary to copper deficiency is characterized by being clinically and radiologically indistinguishable from subacute combined spinal cord degeneration due to vitamin B12 deficiency. Diagnosis and treatment are often delayed. Neurological manifestations are only partially reversible with copper supplementation, demonstrating poor prognosis. In the case described, the important recovery evidenced after the treatment stands out. It is suggested that combined oral and parenteral therapy with a multidisciplinary approach, as motor physiotherapy, are related to better neurological recovery.

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Barros, Gabriel Santaterra, Ana Paula Ramires Chiminazzo, Maria Luiza Ricarte Ruggeri, Maria Luisa Pelaes Stipp e Helen Maia Tavares de Andrade. "Spinal Muscular Atrophy type 4 with respiratory involvement: a case report". In XIII Congresso Paulista de Neurologia. Zeppelini Editorial e Comunicação, 2021. http://dx.doi.org/10.5327/1516-3180.595.

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Context: The Spinal Muscular Atrophy (SMA) is a genetic disease responsible for degeneration of the motor neurons of the spinal cord and the motor nucleus of the cranial nerves. Case report: Male patient, 32 years old, 6 years ago presented proximal weakness in lower limbs and distal weakness in upper limbs with progressive worsening and episodes of dyspnea on physical exercise, without dysphagia and dysarthria. The lower limbs showed grade of power of 3/5 in the proximal muscle group and 4/5 in the distal muscle group. On the upper limbs the grade of power was 4/5 in both proximal and distal group of muscles. Patellar tendon reflex and the bicipital reflexes were intact. Proximal lower limb atrophy, poliminiclonus in upper limbs, and the examination of sensitivity and cranial nerves were unremarkable. Electroneuromyography showed lower motor neuron involvement. MRI of cervical and lumbar spine was normal. Genetic test with homozygous deletion in the SMN1 gene, with four copies of the SMN2 gene. The patient was unable to perform spirometry due to the worsening of the respiratory condition. BIPAP requested, which improved the patient’s condition. Conclusions: There is poor information on literature about the lung function with the disease in adults, with no longitudinal study of the lung function in patients with Spinal Muscular Atrophy 3b and 4. Our case report demonstrates the importance of attempting respiratory symptoms even in adult patients with SMA.

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Yan, Guanjin, Masoud M. Pour, Teresa J. Rinker, Blair E. Carlson e Wenda Tan. "Brief Paper: Spiral Laser Keyhole Welding of Aluminum and Copper: Composition, Microstructure and Properties". In ASME 2024 19th International Manufacturing Science and Engineering Conference. American Society of Mechanical Engineers, 2024. http://dx.doi.org/10.1115/msec2024-125358.

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Abstract Laser keyhole welding of dissimilar metals has been widely used in industrial applications. One critical challenge for this process is the formation of intermetallic compounds (IMCs) that undermine the electrical and mechanical properties of the joints. Compared with the commonly used linear contours, welding with spiral contours can provide larger areas of joining and hence higher allowable loading. This can be particularly useful for certain applications. In this research, laser welding experiments with different spiral contours were performed, and the chemical composition, microstructure, and mechanical properties of the joints were characterized. Three spiral distances were used in the experiments. As the spiral distance was changed from 0.1 mm to 0.3 mm and 0.5 mm, the average Cu concentration in the upper region of the joints was decreased, lower amounts of IMCs were found in the joints, and the joints were capable of sustaining higher mechanical loading.

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Rapporti di organizzazioni sul tema "Copper Spinel"

Harrison, J. C., B. M. Saumur e D. R. Skipton. Mineral and carving-stone resources of Baffin Island. Natural Resources Canada/CMSS/Information Management, 2022. http://dx.doi.org/10.4095/321858.

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Mineral resources of Baffin Island include iron (Mary River), diamonds, carbonate-hosted zinc and lead (Nanisivik), nickel, copper, platinum group elements, uranium, thorium, gemstones (sapphire, spinel, lapis lazuli), carving stone, and coal. Iron deposits include the Mary River No. 1 to 4 deposits of northern Baffin Island, which came into production in 2015 and contain 586 Mt grading 66% Fe. The Mesoproterozoic Borden Basin hosts the Nanisivik deposit, mined between 1976 and 2002; this is a Mississippi Valley-type deposit and contains 9.0% Zn, 0.7% Pb, and 41 ppm Ag. Diamond-rich kimberlite occurs as sheets and small pipes at Chidliak on Hall Peninsula; largest by area is the CH-1 (6 ha) pipe. At least 32 carving-stone localities are known; 7 communities on Baffin Island have good access to quarried material. Coal occurs in the Cretaceous-Paleogene Eclipse Trough of Bylot and northwestern Baffin islands. Exposures near Pond Inlet have been excavated for local use.

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Cahill, David. Extraordinary Spin-Wave Thermal Conductivity in Low-Dimensional Copper Oxides. Fort Belvoir, VA: Defense Technical Information Center, gennaio 2015. http://dx.doi.org/10.21236/ada622603.

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Cavaille, Charlotte, Federica Liberini, Michela Redoano, Anandi Mani, Vera E. Troeger, Helen Miller, Ioana Marinescu et al. Which Way Now? Economic Policy after a Decade of Upheaval: A CAGE Policy Report. A cura di Vera E. Troeger. The Social Market Foundation, febbraio 2019. http://dx.doi.org/10.31273/978-1-910683-41-5.

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Most, if not all advanced economies have suffered gravely from the 2008 global financial crisis. Growth, productivity, real income and consumption have plunged and inequality, and in some cases poverty, spiked. Some countries, like Germany and Australia, were better able to cope with the consequences but austerity has taken its toll even on the strongest economies. The UK is no exception and the more recent period of economic recovery might be halted or even reversed by the political, economic, and policy uncertainty created by the Brexit referendum. This uncertainty related risk to growth could be even greater if the UK leaves the economic and legal framework provided by the EU. This CAGE policy report offers proposals from different perspectives to answer the overarching question: What is the role of a government in a modern economy after the global financial crisis and the Brexit vote? We report on economic and social challenges in the UK and discuss potential policy responses for the government to consider. Foreword by: Lord O’Donnell of Clapham.

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