Journal articles: 'Cobalt and copper'

1

Guo, Lian, Jianwen Han, Eric Yakobson, Wenbo Shao, Kyle Whitten, and Elie Najjar. "Recent Advances in Electrodeposition of Copper Ultrathin Films on Cobalt Substrate." ECS Meeting Abstracts MA2022-02, no. 23 (2022): 955. http://dx.doi.org/10.1149/ma2022-0223955mtgabs.

Full text

Abstract:

As the miniaturization trend in integrated circuits fabrication continues, alternative liner materials in copper interconnects have been actively explored. Cobalt has been widely investigated and employed due to its low resistance at nanoscales, integration compatibility, as well as benefit of improving copper electromigration resistance. However, direct electrodeposition of copper onto cobalt remains less explored due to the stability issue of cobalt in acidic copper damascene process. Subsequent processes of copper seeding and copper electroplating face increasing technical difficulties when widths and aspect ratios of electro-fill features become more challenging. Direct electrodeposition of copper on cobalt has been explored in acidic and alkaline chemistries, both of which were formulated by MacDermid Alpha Semiconductor Solutions. In both cases, well-adherent, nearly-pinhole-free, and ultrathin Cu has been successfully electrodeposited onto cobalt substrate with less than 10% cobalt loss. SEM images in Figure 1 imply uniform dispersion of copper on cobalt. XRF and ICP analysis confirm that the thinnest copper films deposited could be no thicker than 2 nm. Corrosion test in acidic copper plating bath shows that an ultrathin copper layer of thickness less than 2 nm can effectively suppress cobalt dissolution by a factor of three in comparison to non-coated bare cobalt. This work could pave the avenue towards direct copper electrodeposition onto cobalt liner in semiconductor manufacturing for advanced technology nodes. Figure 1. Top-down SEM images. (left) As-received cobalt substrate; (center) Cu of 2 nm nominal thickness electrodeposited on cobalt from an acidic solution; (right) Cu of 2 nm nominal thickness electrodeposited on cobalt from an alkaline solution. All three images have the same scale and scale bars are 200 nm. Figure 1

APA, Harvard, Vancouver, ISO, and other styles

2

(Mrs.), V. A. JADHAV, and VANDRE. "2,7 -Dichloroquinoline-3-carbaldehyde Thiosemicarbazone as an Analytical Reagent for Cobalt(II) and Copper(II)." Journal of Indian Chemical Society Vol. 69, Nov 1992 (1992): 791–92. https://doi.org/10.5281/zenodo.6044492.

Full text

Abstract:

Department of Chemistry. Shivaji University, Kolhapur-416 004 Manuscript received 18 June 1988, revised 15 July 1992, accepted 12 August 1992 2,7 -Dichloroquinoline-3-carbaldehyde Thiosemicarbazone as an Analytical Reagent for Cobalt(II) and Copper(II).

APA, Harvard, Vancouver, ISO, and other styles

3

(MRS.), V. A. JADHAV, and M. U. KULKARNI (Ms.). "7-Methyl-2-chloroquinoline-3-carbaldehyde Thiosemicarbazone as Analytical Reagent for Copper,-Cobalt--and Nickel(II)." Journal of Indian Chemical Society Vol. 69, May 1992 (1992): 287–88. https://doi.org/10.5281/zenodo.6089420.

Full text

Abstract:

Department of Chemistry, Shivaji University, Kolhapur-416 001 Manuscript received 1 August 1988, revised 11 September 1989, accepted 1 April 1992 7-Methyl-2-chloroquinoline-3-carbaldehyde Thiosemicarbazone as Analytical Reagent for Copper,-Cobalt--and Nickel(II).

APA, Harvard, Vancouver, ISO, and other styles

4

Zhou, Fengbo, Bo Wu, and Jianhua Zhou. "Novel Spectrophotometric Method for Robust Detection of Trace Copper and Cobalt in High-Concentration Zinc Solution." Molecules 29, no. 23 (2024): 5765. https://doi.org/10.3390/molecules29235765.

Full text

Abstract:

In the purification process of zinc hydrometallurgy, the spectra of copper and cobalt seriously overlap in the whole band and are interfered with by the spectra of zinc and nickel, which seriously affects the detection results of copper and cobalt in zinc solutions. Aiming to address the problems of low resolution, serious overlap, and narrow characteristic wavelengths, a novel spectrophotometric method for the robust detection of trace copper and cobalt is proposed. First, the Haar, Db4, Coif3, and Sym3 wavelets are used to carry out the second-order continuous wavelet transform on the spectral signals of copper and cobalt, which improves the resolution of copper and cobalt and eliminates the background interference caused by matrix zinc signals and reagents. Then, the information ratio and separation degree are defined as optimization indexes, a multi-objective optimization model is established with the wavelet decomposition scale as a variable, and the non-inferior solution of multi-objective optimization is solved by the state transition algorithm. Finally, the optimal second-derivative spectra combined with the fine zero-crossing technique are used to establish calibration curves at zero-crossing points for the simultaneous detection of copper and cobalt. The experimental results show that the detection performance of the proposed method is far superior to the partial least squares and Kalman filtering methods. The RMSEPs of copper and cobalt are 0.098 and 0.063, the correlation coefficients are 0.9953 and 0.9971, and the average relative errors of copper and cobalt are 3.77% and 2.85%, making this method suitable for the simultaneous detection of trace copper and cobalt in high-concentration zinc solutions.

APA, Harvard, Vancouver, ISO, and other styles

5

Sanpo, Noppakun, James Wang, and Christopher C. Berndt. "Sol-Gel Synthesized Copper-Substituted Cobalt Ferrite Nanoparticles for Biomedical Applications." Journal of Nano Research 22 (May 2013): 95–106. http://dx.doi.org/10.4028/www.scientific.net/jnanor.22.95.

Full text

Abstract:

Copper-substituted cobalt ferrite nanoparticles were prepared via a sol-gel route using citric acid as a chelating agent. The influence of copper concentration on the microstructure, crystal structure and antibacterial property of copper-substituted cobalt ferrite nanoparticles against E. coli and S. aureus has been systematically investigated. The results indicate that the substitution of copper influences strongly the microstructure, crystal structure, particle diameter and antibacterial property of cobalt ferrite nanoparticles.

APA, Harvard, Vancouver, ISO, and other styles

6

Sanpo, Noppakun, James Wang, and Christopher C. Berndt. "Sol-Gel Synthesized Copper-Substituted Cobalt Ferrite Nanoparticles for Biomedical Applications." Journal of Nano Research 25 (October 2013): 110–21. http://dx.doi.org/10.4028/www.scientific.net/jnanor.25.110.

Full text

Abstract:

Copper-substituted cobalt ferrite nanoparticles were prepared via a sol-gel route using citric acid as a chelating agent. The influence of copper concentration on the microstructure, crystal structure and antibacterial property of copper-substituted cobalt ferrite nanoparticles against E. coli and S. aureus has been systematically investigated. The results indicate that the substitution of copper influences strongly the microstructure, crystal structure, particle diameter and antibacterial property of cobalt ferrite nanoparticles.

APA, Harvard, Vancouver, ISO, and other styles

7

Yang, Wei Jiao, Cheng Yan Wang, Bao Zhong Ma, Zhong Wang, Yong Qiang Chen, and Fei Yin. "Recovery of Cobalt from Copper Converter Slag by a Selective Reduction-Roasting Process." Advanced Materials Research 550-553 (July 2012): 2186–89. http://dx.doi.org/10.4028/www.scientific.net/amr.550-553.2186.

Full text

Abstract:

An industrial converter slag was treated by a selective reduction-roasting process to recovery cobalt and copper in this study. To maximizing the recovery of cobalt and copper, the major process parameters such as reducing agent, curing agent and roasting temperature were investigated. Under the determined conditions, 95% cobalt and 96% copper can be recovered. According to the mineralogical analysis, it is found that cobalt in the converter slag mainly distributes in the iron-bearing minerals, which migrates with iron during the reduction-roasting process. After the reduction-roasting, most cobalt distributes in the metallic iron in the form of Co-Fe alloy.

APA, Harvard, Vancouver, ISO, and other styles

8

Flores-Lasluisa, Jhony Xavier, Javier Quílez-Bermejo, Ana Cristina Ramírez-Pérez, Francisco Huerta, Diego Cazorla-Amorós, and Emilia Morallón. "Copper-Doped Cobalt Spinel Electrocatalysts Supported on Activated Carbon for Hydrogen Evolution Reaction." Materials 12, no. 8 (2019): 1302. http://dx.doi.org/10.3390/ma12081302.

Full text

Abstract:

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.

APA, Harvard, Vancouver, ISO, and other styles

9

Zhang, Zhiwei, Xiang Zhao, and Sadahiro Tsurekawa. "Diffusion in Copper/Cobalt Systems under High Magnetic Fields." Materials 14, no. 11 (2021): 3104. http://dx.doi.org/10.3390/ma14113104.

Full text

Abstract:

Comprehensive research on a high magnetic field’s effect on diffusion is lacking; hence, this study investigates the effect of the magnetization of such a field on diffusion using a copper/cobalt diffusion couple in the diamagnetic/ferromagnetic states, respectively. The diffusion couple was formed using explosive welding to avoid diffusion during manufacturing. The diffusion couple annealed within a temperature range of 1165–1265 K under a 0–6-T high magnetic field. The angle between the diffusion and magnetic field directions was set as 0° and then 180°. The penetration profiles of cobalt volume diffusion in the copper and grain-boundary diffusion of copper in cobalt were constructed using an electron probe micro analyzer. The high magnetic field increased the volume diffusivity of cobalt in copper, but had no evident effect on the grain-boundary diffusivity of copper in cobalt, irrespective of the magnetic field direction. An Arrhenius plot of the cobalt volume diffusivity in copper demonstrated that the applied high magnetic field enhanced diffusion by changing the frequency factor rather than the activation energy; this can be attributed to the increased diffusion entropy caused by changing the vacancy concentration, which resulted from the introduction of magnetization under a high magnetic field.

APA, Harvard, Vancouver, ISO, and other styles

10

Zeng, Gui Sheng, Ming Jing Li, and Yu Xie. "Influencing Factors and Mechanism of Cobalt Redissolution from Zinc Sulphate Solution." Advanced Materials Research 402 (November 2011): 12–16. http://dx.doi.org/10.4028/www.scientific.net/amr.402.12.

Full text

Abstract:

Redissolution of cemented cobalt from zinc sulphate solution occurs, and is a well known problem among zinc producers. A variety of mechanism of cobalt redisisolution have been proposed in the literatures, however, it is still not very well understood. The influencing factors of cobalt redissolution such as detention time, oxidation, particle size of zinc dust and copper ion have been investigated in this paper. The redissolution does not occur when very large particles are used but the redissolution of cobalt is significant from small zinc particles. The redissolution is obvious with copper ion added, while the redissolution is not occurred from the zinc sulphated solution without copper ion added. The redissolution mechanism of cobalt is obtained.

APA, Harvard, Vancouver, ISO, and other styles

11

Bilouk, Sabrina, Carole Pernel, Lucile Broussous, Valentina Ivanova, and Ricardo Nogueira. "Electrochemical Behavior of Cobalt in Post-Via Etch Cleaning Solutions." Solid State Phenomena 145-146 (January 2009): 343–46. http://dx.doi.org/10.4028/www.scientific.net/ssp.145-146.343.

Full text

Abstract:

The integration of CoWP and CoWB self-aligned barriers (SAB) for 32 nm technology nodes allows improving copper interconnections reliability [1, 3]. However the introduction of such materials in copper interconnection levels drives new challenges for plasma dry etch and wet clean processes. Indeed, during the post-via-etch cleaning step, cobalt and copper can be altered by corrosion. Moreover, a galvanic coupling between cobalt, the major component of SAB, and copper can thermodynamically occur. In this way, the cleaning solution acts as ionic medium providing a contact between the two metals. Thus, both metals polarize to a mixed potential comprised between the individual open circuit potentials (OCP) of cobalt and copper. As a result, the less noble metal can suffer from accelerated corrosion, and the more noble metal corrodes with slower rate. According to thermodynamic aspects, cobalt in contact with copper is the less noble metal. Consequently, Co is susceptible to undergo galvanic corrosion which may enhance the dissolution of the SAB.

APA, Harvard, Vancouver, ISO, and other styles

12

de la Torre, Ernesto, Ana Lozada, Maricarmen Adatty, and Sebastián Gámez. "Activated Carbon-Spinels Composites for Waste Water Treatment." Metals 8, no. 12 (2018): 1070. http://dx.doi.org/10.3390/met8121070.

Full text

Abstract:

Nowadays, mining effluents have several contaminants that produce great damage to the environment, cyanide chief among them. Ferrites synthesized from transition metals have oxidative properties that can be used for cyanide oxidation due to their low solubility. In this study, cobalt and copper ferrites were synthesized via the precipitation method, using cobalt nitrate, copper nitrate, and iron nitrate as precursors in a molar ratio of Co or Cu:Fe = 1:2 and NaOH as the precipitating agent. The synthesized ferrites were impregnated in specific areas on active carbon. These composites were characterized using X-Ray Diffraction (XRD) and Scanning Electron Spectroscopy (SEM). The XRD results revealed a cubic spinel structure of ferrites with a single phase of cobalt ferrite and two phases (copper ferrite and copper oxides) for copper. The CoFe2O4 impregnated on active carbon reached a cyanide oxidation of 98% after 8 h of agitation; the composite could be recycled five times with an 18% decrease in the catalytic activity. In cobalt ferrites, a greater dissolution of iron than cobalt was obtained. In the case of copper ferrite, however, the copper dissolution was higher. These results confirm that ferrites and activated carbon composites are a novel alternative for cyanide treatment in mining effluents.

APA, Harvard, Vancouver, ISO, and other styles

13

Muanda, Meschack Mukunga, Pele Pascal Daniel Omalanga, and Vanessa Mwambaie Mitonga. "Comparative Cleaning Stages in Recovery of Copper and Cobalt from Tailings using Potassium Amylxanthate as Collector." European Journal of Engineering and Technology Research 6, no. 2 (2021): 96–100. http://dx.doi.org/10.24018/ejers.2021.6.2.2165.

Full text

Abstract:

Copper and cobalt demand is projected to be increased from here to 2050 and the challenge is to find treat economically minerals which contains those metals. Several tailings from oxide ores throughout the word contain good grades of copper and cobalt that should be recovered by froth flotation. This paper investigates the recovery of copper and cobalt through reprocessing of spiral classifier tailings by determination of specific reagents dosage. The flotation behaviours of malachite and heterogenite were studied through many roughing and cleaning flotation tests in order to recovery most of copper and cobalt. The effect of specific reagents was be varied and others parameters were kept constant. The highest recoveries of both copper and cobalt in rougher concentrate were respectively 82.51% and 72.51% with grades of 12.52% and 0.99% respectively. However, the cleaner concentrate was 24.54 Cu% and 1.38% Co with recoveries of 69.26 % and 40.7% respectively. It was concluded that the reprocessing of spiral classifier tailings through froth flotation is benefit because it recovers most of desired metal and reduces the risk of their presence on environment through.

APA, Harvard, Vancouver, ISO, and other styles

14

Muanda, Meschack Mukunga, Pele Pascal Daniel Omalanga, and Vanessa Mwambaie Mitonga. "Comparative Cleaning Stages in Recovery of Copper and Cobalt from Tailings using Potassium Amylxanthate as Collector." European Journal of Engineering and Technology Research 6, no. 2 (2021): 96–100. http://dx.doi.org/10.24018/ejeng.2021.6.2.2165.

Full text

Abstract:

Copper and cobalt demand is projected to be increased from here to 2050 and the challenge is to find treat economically minerals which contains those metals. Several tailings from oxide ores throughout the word contain good grades of copper and cobalt that should be recovered by froth flotation. This paper investigates the recovery of copper and cobalt through reprocessing of spiral classifier tailings by determination of specific reagents dosage. The flotation behaviours of malachite and heterogenite were studied through many roughing and cleaning flotation tests in order to recovery most of copper and cobalt. The effect of specific reagents was be varied and others parameters were kept constant. The highest recoveries of both copper and cobalt in rougher concentrate were respectively 82.51% and 72.51% with grades of 12.52% and 0.99% respectively. However, the cleaner concentrate was 24.54 Cu% and 1.38% Co with recoveries of 69.26 % and 40.7% respectively. It was concluded that the reprocessing of spiral classifier tailings through froth flotation is benefit because it recovers most of desired metal and reduces the risk of their presence on environment through.

APA, Harvard, Vancouver, ISO, and other styles

15

Altinkaya, Pelin, Jarno Mäkinen, Päivi Kinnunen, Eero Kolehmainen, Mika Haapalainen, and Mari Lundström. "Effect of biological pretreatment on metal extraction from flotation tailings for chloride leaching." Minerals Engineering 129, December 2018 (2018): 47–53. https://doi.org/10.1016/j.mineng.2018.09.012.

Full text

Abstract:

This study focuses on investigating the extraction of gold, copper, iron, nickel, cobalt, and zinc present in the flotation tailings. The studied sample contained iron (3.56%), copper (0.09%), and gold (0.2 ppm) as major target elements, whereas cobalt (0.04%), nickel (0.03%) and zinc (0.04%) were trace elements of interest. Primarily, bioleaching with mixed acidophilic culture was applied as a pretreatment process for the recovery of nickel, cobalt, and zinc, as well as for iron removal. The effect of solid concentration (5–12.5%) in bioleaching was investigated at pH 1.8 and the temperature was kept at 32 °C. The highest extractions of nickel, cobalt, zinc, and iron at 5% and 7.5% solid concentrations in the bioleaching experiments were 90%, 60%, 86% and 67%, respectively. Dissolution of gold and copper was not observed. The residues from bioleaching pretreatment were applied for chemical chloride leaching to extract gold and copper into the solution. In chloride leaching, the highest extractions of copper and gold were 98% and 63%, respectively. In addition, residual nickel, cobalt, and zinc were dissolved into the solution with the extraction of 99%, 80%, and 90%, respectively. In all chloride leaching experiments, the highest extractions of iron, copper, gold, nickel, cobalt, and zinc were observed with biologically pretreated feed. Alternatively, residues from bioleaching were also subjected to conventional cyanide leaching. Dissolutions of copper, nickel, cobalt and zinc were shown to be higher in chloride solution, however, 7%-unit more of gold could be extracted by cyanidation. With these findings, it appears that the combination of biological pretreatment and chloride leaching can provide a non-toxic process for improved valuable metals extraction from low-grade tailings.

APA, Harvard, Vancouver, ISO, and other styles

16

Dulal, S. M. S. I., E. A. Charles, and S. Roy. "Dissolution from electrodeposited copper–cobalt–copper sandwiches." Journal of Applied Electrochemistry 34, no. 2 (2004): 151–58. http://dx.doi.org/10.1023/b:jach.0000009945.92160.25.

Full text

APA, Harvard, Vancouver, ISO, and other styles

17

Kendall, N. R., D. W. Jackson, A. M. Mackenzie, D. V. Illingworth, I. M. Gill, and S. B. Telfer. "The effect of a zinc, cobalt and selenium soluble glass bolus on the trace element status of extensively grazed sheep over winter." Animal Science 73, no. 1 (2001): 163–69. http://dx.doi.org/10.1017/s135772980005815x.

Full text

Abstract:

AbstractThe effects of trace element deficiencies in lambs, particularly zinc, copper, cobalt and selenium, include decreased growth rates and increased mortality. However, trace element supplementation of sheep reared under extensive conditions has several logistical problems.Two trials were designed to investigate the effect of a zinc, cobalt and selenium soluble glass bolus on the trace element status of out-wintered ewe lambs. In trial 1 600 8-month-old ewe lambs (500 Scottish Blackface and 100 North Country Cheviots) were allocated to two treatment groups; 300 were treated with a zinc, cobalt and selenium soluble glass bolus (zinc) and 300 were untreated (control). In trial 2, 315 8-month-old Scottish Blackface ewe lambs were allocated to three treatments: 105 were treated with the zinc, cobalt and selenium soluble glass bolus (zinc), 105 were treated with a copper, cobalt and selenium soluble glass bolus (copper) and the remaining 105 were untreated (control). Blood samples were collected immediately prior to giving boluses and again after approximately 4 months. These were assessed for zinc (plasma zinc concentration), cobalt (serum vitamin B12concentration), selenium (erythrocyte glutathione peroxidase activity) and copper status (plasma copper concentration, caeruloplasmin, amine oxidase and superoxide dismutase activity and calculation of the ratio between the caeruloplasmin and plasma copper).The zinc bolus in both trials significantly increased the plasma zinc concentrations (P< 0·001 andP< 0·01 respectively), erythrocyte glutathione peroxidase activities (P< 0·001) and serum vitamin B12concentrations (P< 0·001). The copper bolus also significantly increased the erythrocyte glutathione peroxidase activities (P< 0·001) and serum vitamin B12concentrations (P< 0·001) when compared with the controls but were not significantly different from the zinc group. The copper bolus significantly increased all of the copper status indicators (P< 0·01) when compared with the control and zinc groups. However, in trial 1 when only the zinc and control groups were compared, the zinc bolus significantly increased the ratio (P< 0·001) and serum caeruloplasmin (P< 0·001) and erythrocyte superoxide dismutase (P< 0·01) activities. These responses were not observed in trial 2 with the erythrocyte superoxide dismutase being significantly reduced in the zinc group when compared with the control group (P< 0·001).The zinc, cobalt and selenium soluble glass bolus increased the status of all three trace elements consistently for a period of at least 100 days. The increases of cobalt and selenium status were similar to those achieved using the copper, cobalt and selenium bolus, which also increased the copper status of the sheep.

APA, Harvard, Vancouver, ISO, and other styles

18

Yin, Jiawei, Benfeng Cao, Xiaolin Peng, et al. "U-Shaped Association Between Plasma Cobalt Levels and Type 2 Diabetes." Current Developments in Nutrition 4, Supplement_2 (2020): 1855. http://dx.doi.org/10.1093/cdn/nzaa067_082.

Full text

Abstract:

Abstract Objectives The aim of this study was to investigate the association of plasma cobalt with newly diagnosed T2D. The potential interactions of plasma cobalt with copper and metallothioneins (MTs) polymorphisms were further evaluated. Methods A large case-control study including 4564 participants: 2282 newly diagnosed T2D cases and 2282 controls with normal glucose tolerance (NGT). Plasma cobalt and copper concentrations were measured with inductively coupled plasma mass spectrometry (ICPMS). In addition, MTs polymorphisms were genotyped in a random subset of participants (827 T2D and 827 NGT) by Agena MassArray System. Results The medians of the plasma cobalt concentrations were 1.88 μg/dL for NGT and 2.22 μg/L for T2D. A U-shaped association was observed between plasma cobalt and T2D. From the lowest to the highest quartiles of plasma cobalt, the multivariable adjusted ORs of T2D were 1.29 (1.07–1.56), 1.20 (0.99–1.45), 1.00 (reference) and 1.62 (1.34–1.96), respectively. The U-shaped association was consistently indicated in subgroups and in spline analysis with the lowest odds of T2D at the cobalt concentration of 2.00 μg/dL. There was a statistically significant interaction between plasma cobalt and copper (P &lt; 0.01), and cobalt showed a positive association of T2D in those with the lowest tertile of plasma copper. Conclusions Both low and high levels of plasma cobalt were associated with higher odds of T2D, and the association could be modified by plasma copper concentrations. Funding Sources This work was funded by the National Key Research and Development Program of China, the Major International (Regional) Joint Research Project, the National Natural Science Foundation of China, the Young Scientists Fund of the National Natural Science Foundation of China and the China Postdoctoral Science Foundation.

APA, Harvard, Vancouver, ISO, and other styles

19

M.S., RIZK, M. ABDEL-FATIAH H., M. IKHLASS, ABBASS, and M. ISSA Y. "Stability of some Arylhydrazo-5-pyrazolones Chelates with Divalent Iron, Cobalt, Nickel, Copper and Zinc." Journal of Indian Chemical Society Vol. 71, Feb 1994 (1994): 93–95. https://doi.org/10.5281/zenodo.5893978.

Full text

Abstract:

Department of Chemistry, Faculty of Science, University of Cairo, Giza, Egypt Manuscript received 30 June 1992, revised 23 April 1993, accepted 30 April 1993 Stability of some Arylhydrazo-5-pyrazolones Chelates with Divalent Iron, Cobalt, Nickel, Copper and Zinc.

APA, Harvard, Vancouver, ISO, and other styles

20

MONALISA, BHATTACHARYA, and C. CHATTOPADHYAYA M. "Heterogeneous Coated Wire Copper(II) and Cobalt(II) Ion Selective Electrodes based on Solid Ion-Exchange Resin." Journal of Indian Chemical Society Vol. 64, Sep 1987 (1987): 575–76. https://doi.org/10.5281/zenodo.6217528.

Full text

Abstract:

Chemical Laboratories, University of Allahabad, Allahabad-211 002 Manuscript received 2 September 1986, revised 4 August 1987, accepted 17 August 1987 Heterogeneous Coated Wire Copper(II) and Cobalt(II) Ion Selective Electrodes based on Solid Ion-Exchange Resin.

APA, Harvard, Vancouver, ISO, and other styles

21

Shokrollahi, Ardeshir, and Foroogh Ebrahimi. "Supramolecular-Based Ultrasonic-Assisted Dispersion Solidification Liquid–Liquid Microextraction of Copper and Cobalt Prior to Their Flame Atomic Absorption Spectrometry Determination." Journal of AOAC INTERNATIONAL 100, no. 6 (2017): 1861–68. http://dx.doi.org/10.5740/jaoacint.17-0042.

Full text

Abstract:

Abstract In the present work, a simple, efficient, and environmentally friendly method was proposed for the simultaneous preconcentration and determination of minute quantities of copper and cobalt in water samples and serum by a supramolecular-based ultrasonic-assisted dispersion solidification liquid–liquid microextraction (DSLLME) procedure coupled with flame atomic absorption spectrometry. The procedure is based on the DSLLME of copper and cobalt with decanoic acid–tetrahydrofuran supramolecular solvent (SUPRAS) in the presence of sodium diethyldithiocarbamate, as the complexing agent. SUPRAS is a nanostructured liquid generated from amphiphiles through a sequential self-assembly process occurring on two scales, molecular and nano. Several variables that affect the extraction efficiency—including pH, concentration of complexing agent, volume of the extraction and dispersive solvents (volume of SUPRAS), sonication time, and ionic strength—were investigated and optimized. The method provided enrichment factors of 23.31 and 22.38 for copper and cobalt, respectively. The preconcentration factor for the two analytes was 20.00. Calibration plots were linear in the range of 5.00–700.00 ng/mL for copper and 5.00–500.00 ng/mL for cobalt, with correlations of determination of 0.9973 and 0.9981. The precision of the method were expressed as RSDs for six replicate measurements and LODs and found to be ±4.10 and ±2.30% for copper and 2.90 and 3.50 ng/mL for cobalt. The proposed method was successfully applied to the simultaneous determination of trace copper and cobalt in real water samples and serum with satisfactory results.

APA, Harvard, Vancouver, ISO, and other styles

22

Mohammed, M. H. "Modified method for the determination of cobalt (II) and copper (II) ions by adopting schiff base complexes in water of Shatt Al-Arab river." Mesopotamian Journal of Marine Sciences 26, no. 2 (2022): 170–81. http://dx.doi.org/10.58629/mjms.v26i2.182.

Full text

Abstract:

A new method of complex formation between cobalt or copper ions and Schiff Base (derived from Schiff Base of salicyldehyde and amino acids) was adopted for the determination of cobalt and copper ions in water samples of Shatt Al-Arab River. For water sampling three stations along Shatt Al-Arab River were selected as follows: 1) discharging point in Shatt Al-Arab from Basrah paper and mill industries, 2) Karmatt Ali Bridge, and 3) Siba downstream to the southern region of Shatt Al-Arab river. After the formation of a complex with Schiff Base, Cobalt and Copper in the water of Shatt Al-Arab were determined spectrophotometricaly at wave length of 270 nm and 295 nm respectively. It is found that cobalt concentrations were (0.152, 0.174, 0.165) mg.l-1 and copper concentrations were (0.014, 0.021, 0.023) mg.l-1 in stations 1, 2 and 3, respectively. The method is reliable with sensitivity, accuracy, standard deviation and detection limit of (0.0235 gm.cm.l-1, 3.05×10-6, 0.00184, 0.52×10-7) for cobalt complex and (0.0135 gm.cm.l-1, 3.31×10-6, 0.00215, 0.6×10-8) for copper complex, respectively.

APA, Harvard, Vancouver, ISO, and other styles

23

H., C. MALHOTRA, and KUMAR AMITA. "A Kinetic Study on the Complexation Reactions of Nickel-, Cobalt- and Copper(II) with L-2-Aminobutanedioic acid 4-amide." Journal of Indian Chemical Society Vol. 72, Jun 1995 (1995): 407–11. https://doi.org/10.5281/zenodo.5904995.

Full text

Abstract:

Department of Chemistry, University of Delhi, Delhi-110 007 Manuscript received 25 June 1993, revised 4 November 1993, accepted 14 December 1993 A Kinetic Study on the Complexation Reactions of Nickel-, Cobalt- and Copper(II) with L-2-Aminobutanedioic acid 4-amide

APA, Harvard, Vancouver, ISO, and other styles

24

Muraveikо, I. A., and A. V. Demidov. "MODIFICATION OF THE BRASS COATING BY COBALT." Litiyo i Metallurgiya (FOUNDRY PRODUCTION AND METALLURGY), no. 2 (July 7, 2018): 85–88. http://dx.doi.org/10.21122/1683-6065-2018-2-85-88.

Full text

Abstract:

The main parameters affecting the cobalt content in the brass coating are determined, the chemical composition of the coating and the cobalt content in the coating thickness are investigated. Cobalt was applied to the brass coating from a separate bath. The sequence of application is as follows: Cu+Zn+Co. Copper coating was applied only from the electrolyte of alkaline copper plating.

APA, Harvard, Vancouver, ISO, and other styles

25

Ryabushkin, Maksim I., Dmitriy S. Savoskin, Aleksandr P. Tyukin, et al. "DEEP COPPER PURIFICATION OF NICKEL-COBALT SOLUTIONS OF KOLA MMC." Transactions of the Kоla Science Centre of RAS. Series: Engineering Sciences 2, no. 2/2023 (2023): 218–22. http://dx.doi.org/10.37614/2949-1215.2023.14.2.041.

Full text

Abstract:

It has been established that when using a mixture of metallic iron and sulfur for precipitation, deep copper purification of nickel-cobalt chloride solutions is possible. Industrial tests of copper purification of cobalt concentrate leaching solutions with an iron-sulfur reagent were carried out, during which a decrease in copper concentration to 10 mg/l or less was achieved.

APA, Harvard, Vancouver, ISO, and other styles

26

K., J. SHAH, V. RATHOD B., and D. NAKRANI A. "Copper(II), Nickel(II) and Cobalt(II) Complexes of N-Phenyi-N'-( 6-methyl)benzothiazolyl Thiocarbamide." Journal of Indian Chemical Society Vol. 67, Nov 1990 (1990): 898–99. https://doi.org/10.5281/zenodo.6255001.

Full text

Abstract:

University Department of Chemistry, Bhavnagar University, Bhavnagar-364 002 Manuscript received 21 April 1989, revised 30 July 7990, accepted 24 September 1990 Copper(II), Nickel(II) and Cobalt(II) Complexes of N-Phenyi-N'-( 6-methyl)benzothiazolyl Thiocarbamide

APA, Harvard, Vancouver, ISO, and other styles

27

Okoli, Nonso Livinus, Laz Nnadozie Ezenwaka, Ngozi Agatha Okereke, Ifeyinwa Amaka Ezenwa, and Nwode Augustine Nwori. "Investigation of Optical, Structural, Morphological and Electrical Properties of Electrodeposited Cobalt Doped Copper Selenide (Cu_(1-x) Co_x Se) Thin Films." Trends in Sciences 19, no. 16 (2022): 5686. http://dx.doi.org/10.48048/tis.2022.5686.

Full text

Abstract:

Undoped and cobalt doped copper selenide thin films have been successfully prepared unto fluorine tin oxide (FTO) substrates by electrodeposition method using copper acetate, cobalt nitrate and selenium (IV) oxide as precursors for copper, cobalt and selenium ions respectively. Deposited thin films were subjected to optical, structural, morphological, compositional and electrical analysis using spectrophotometer, x-ray diffractometer, scanning electron microscope (SEM), energy dispersive x-ray spectroscopy (EDS) and 4-point probe. Optical results observed between the wavelength range of 300 nm and 1,000 nm showed that the films have good optical responses. Absorbance values ranged between 0.1 and 0.81 while transmittance lies between 15.59 and 78.68 %. Energy band gap of the films was found to vary from 2.10 to 2.28 eV. These results showed that cobalt as a dopant could be used to modify properties of copper selenide thin films. Structural analysis showed that the deposited films are polycrystalline in nature with hexagonal structural phase. Crystallite sizes of range 27.56 to 34.27 nm were obtained while dislocation density lied between and . Microstrain ranged between and . Micrograph images showed flake-like particles that increased in size as percentage of cobalt increased. Energy dispersive spectroscope (EDS) results confirmed the incorporation of cobalt on the deposited copper selenide films. Electrical resistivity of the films increased from to while conductivity decreased from to as a result of variation in cobalt ion concentration. These properties of the deposited thin films positioned them for solar cell and optoelectronics device applications. HIGHLIGHTS  Energy band gap of electrosynthesized cobalt doped copper selenide ranged from 2.10 to 2.28 eV Film thickness values ranged from 48.41 and 176.79 nm. Thickness values of the films were found to increase as concentration of cobalt increase Increase in dopant concentration resulted to shift in diffraction peaks towards larger angles Increase in crystallite size from 27.56 - 34.27 nm was observed as dopant concentration increases SEM images of the films revealed flake - like particles of different sizes  GRAPHICAL ABSTRACT

APA, Harvard, Vancouver, ISO, and other styles

28

Kendall, N. R., N. C. Farrar, D. V. Illingworth, D. W. Jackson, and S. B. Telfer. "The use of a soluble glass copper, cobalt and selenium bolus to supply selenium to sheep." Proceedings of the British Society of Animal Science 1999 (1999): 99. http://dx.doi.org/10.1017/s1752756200002544.

Full text

Abstract:

Many sheep may require supplementation with cobalt or selenium, whilst many also require copper for the prevention of swayback. Often more than one are in short supply and blanket supplementation is often the answer, but this could result in problems of toxicity especially with copper in sheep. This trial was carried out on a flock known to be copper sufficient to investigate the supplementation of extra copper in the form of a sintered soluble glass bolus being used to supply selenium and cobalt to the flock.Two batches of Lleyn sheep were selected, the first were forty ewe lambs, whilst the second set were thirty gimmers. The ewe lambs were randomly split into two groups one being given a copper, cobalt and selenium bolus (Cosecure®, Telsol Ltd) with the other group remaining untreated as controls.

APA, Harvard, Vancouver, ISO, and other styles

29

BIPIN, B. MAHAPATRA, D. MAHAPATRO DAMBARU, R. MISHRA RAMANI, and K. KAR SUKHENDU. "Polymetallic Complexes. Part-XLII. Complexes of Cobalt-, Nickel-, Copper-, Zinc-, Cadmium- and Mercury(II) with a ONNO Donor Azo Dye, 4,4'-Bis( ethylcyanoacetate-2' -azo )diphenyl." Journal of Indian Chemical Society Vol. 72, May 1995 (1995): 347–48. https://doi.org/10.5281/zenodo.5904936.

Full text

Abstract:

Department of Chemistry, Khallikote Autonomous College, Berhampur-760 001 Manuscript received 15 March 1993. revised 23 November 1993, accepted 9 December 1993 Polymetallic Complexes. Part-XLII. Complexes of Cobalt-, Nickel-, Copper-, Zinc-, Cadmium- and Mercury(II) with a ONNO Donor Azo Dye, 4,4'-Bis( ethylcyanoacetate-2' -azo )diphenyl

APA, Harvard, Vancouver, ISO, and other styles

30

Kendall, N. R., A. M. Mackenzie, D. V. Illingworth, et al. "Large scale field trials of a soluble glass zinc, cobalt and selenium bolus given to sheep." Proceedings of the British Society of Animal Science 1998 (1998): 209. http://dx.doi.org/10.1017/s1752756200598615.

Full text

Abstract:

Many sheep in the United Kingdom are grazed on pastures deficient in cobalt and selenium. Proprietary products for selenium and cobalt supplementation often contain copper, which in certain breeds can induce copper toxicity. A soluble glass bolus has been manufactured to supply long term sustained release of cobalt and selenium similar to the commercially available Cosecure, but with the copper content being replaced by zinc. Sub clinical zinc deficiency has been suggested to be involved in disease conditions such as broken mouth periodontitis, footrot and mastitis. Therefore a long term continuous supply of zinc may be beneficial in these situations. This trial was designed to examine the effect of administering a zinc, cobalt and selenium soluble glass bolus on trace element status of over-wintered ewe lambs.

APA, Harvard, Vancouver, ISO, and other styles

31

Kendall, N. R., A. M. Mackenzie, D. V. Illingworth, et al. "Large scale field trials of a soluble glass zinc, cobalt and selenium bolus given to sheep." Proceedings of the British Society of Animal Science 1998 (1998): 209. http://dx.doi.org/10.1017/s030822960003422x.

Full text

Abstract:

Many sheep in the United Kingdom are grazed on pastures deficient in cobalt and selenium. Proprietary products for selenium and cobalt supplementation often contain copper, which in certain breeds can induce copper toxicity. A soluble glass bolus has been manufactured to supply long term sustained release of cobalt and selenium similar to the commercially available Cosecure, but with the copper content being replaced by zinc. Sub clinical zinc deficiency has been suggested to be involved in disease conditions such as broken mouth periodontitis, footrot and mastitis. Therefore a long term continuous supply of zinc may be beneficial in these situations. This trial was designed to examine the effect of administering a zinc, cobalt and selenium soluble glass bolus on trace element status of over-wintered ewe lambs.

APA, Harvard, Vancouver, ISO, and other styles

32

Masters, DG, and DW Peter. "Marginal deficiencies of cobalt and selenium in weaner sheep: response to supplementation." Australian Journal of Experimental Agriculture 30, no. 3 (1990): 337. http://dx.doi.org/10.1071/ea9900337.

Full text

Abstract:

Five groups of 30 weaner wethers were given (i) no treatment, or a supplement of either (ii) copper (injection), (iii) cobalt (intraruminal pellet), (iv) selenium (intraruminal pellet) or (v) copper, cobalt plus selenium (intraruminal, soluble glass bolus). Liveweight, wool growth and indicators of copper, cobalt and selenium status were measured over a 54-week experimental period. The provision of all 3 elements resulted in a 180 g increase (P<0.05) in clean wool growth relative to controls. With selenium or cobalt alone there was a trend towards increases in clean wool, whereas wool growth of copper treated sheep was identical to the controls. There were no persistent or significant treatment effects on liveweight. The results indicate that both wool and liveweight changes should be used to assess responses to trace elements and show that combined deficiencies, not detectable in experiments using single element supplements, may depress productivity in grazing sheep. Glass boluses were an effective method of providing selenium and raised selenium in liver and plasma for 54 weeks. Selenium pellets resulted in smaller, less persistent increases in these tissues. Glass boluses were less effective than cobalt pellets in providing cobalt and resulted in only a small increase in vitamin B12 at 26 weeks (P=0.1), compared with increases due to cobalt pellets at both 26 and 54 weeks (P<0.05).

APA, Harvard, Vancouver, ISO, and other styles

33

Ge, Bao Liang, Qing Li, Jie Liu, Yan Xiong Fu, and Guang Hua Hu. "Roughing Conditions Research to Recover a Nickel Ore." Advanced Materials Research 813 (September 2013): 234–37. http://dx.doi.org/10.4028/www.scientific.net/amr.813.234.

Full text

Abstract:

The ore from Jingping contains 0.634% nickel, 0.329% copper, 0.047% cobalt, 30.18% SiO2and 19.72% MgO. In order to obtain satisfying beneficiation results, a lot of tests were taken out before, and this article main focus on roughing flotation conditions. Finally find that when the sodium carbonate dosage is 2000g/t, carboxy-methyl cellulose (CMC) dosage is 200g/t, sodium silicate dosage is 100g/t, the combinational effect can depressing the gangue minerals as well as the slime. The final concentration contains 3.03% nickel, 2.01% copper and 2.40% cobalt, the recovery of the nickel, copper and cobalt is 73.03%, 92.58%, 77.62% respectively.

APA, Harvard, Vancouver, ISO, and other styles

34

Mos, Yvonne M., Arnold C. Vermeulen, Cees N. J. Buisman, and Jan Weijma. "X-Ray Diffraction of Iron Containing Samples: The Importance of a Suitable Configuration." Solid State Phenomena 262 (August 2017): 545–48. http://dx.doi.org/10.4028/www.scientific.net/ssp.262.545.

Full text

Abstract:

X-ray diffraction (XRD) is a commonly used technology to identify crystalline phases. However, care must be taken with the combination of XRD configuration and sample. Copper (most commonly used radiation source) is a poor match with iron containing materials due to induced fluorescence. Magnetite and maghemite are analysed in different configurations using copper or cobalt radiation. Results show the effects of fluorescence repressing measures and the superiority of diffractograms obtained with cobalt radiation. Diffractograms obtained with copper radiation make incontestable phase identification often impossible. Cobalt radiation on the other hand yields high quality diffractograms, making phase identification straightforward.

APA, Harvard, Vancouver, ISO, and other styles

35

Kumari, S. Sudha. "Antimicrobial Activity of Copper(II) and Cobalt(II) Complexes of Citral-Valine Derived Schiff Base." Asian Journal of Chemistry 32, no. 1 (2019): 192–94. http://dx.doi.org/10.14233/ajchem.2020.21801.

Full text

Abstract:

In present work, the screening of antimicrobial activities of copper(II) and cobalt(II) complexes with Schiff base ligand derived from the condensation of citral with valine (amino acid) was carried out on agar plates are reported. The antibacterial activity of Schiff base and its copper(II) and cobalt(II) complexes were evaluated against two bacterial strains Staphylococcus aureus (Gram-positive), Escherichia coli (Gram-negative) and fungus Candida albicans. The results revealed that the Schiff base ligand exhibited the poor antimicrobial activity against Escherichia coli and Candida albicans except for Staphylococcus aureus. Generally, Gram-negative bacteria shows rigid outer membrane, well enough to defend against the drug but Schiff base (citral with valine derived) impregnated cobalt(II) complex seem to be more active against Escherichia coli organisms in comparison to copper(II) complex, which exhibits higher activity than uncomplexed ligand. The antimicrobial results revealed that cobalt(II) and copper(II) complexes have a considerable antibacterial activity than antifungal activity and suggest their potential application as antibacterial agents.

APA, Harvard, Vancouver, ISO, and other styles

36

Sukul, Abhijit, Sreedam Chandra Das, Sajal Kumar Saha, and SM Abdur Rahman. "Screening of Analgesic, Antimicrobial, Cytotoxic and Antioxidant Activities of Metal Complexes of Indomethacin." Dhaka University Journal of Pharmaceutical Sciences 13, no. 2 (2015): 175–80. http://dx.doi.org/10.3329/dujps.v13i2.21895.

Full text

Abstract:

The present study was performed to evaluate the biological activities of metal complexes of indomethacin with cobalt, copper, manganese and zinc. In radiant tail flick method, complexes of indomethacin with cobalt and copper at a dose of 20 mg/kg b.w. showed significant central analgesic activity having 66.09% and 75.45% elongation of time after 30 minutes and complexes of indomethacin with copper at a dose of 20 mg/kg b.w. showed significant central analgesic activity having 62.47% elongation of time after 60 minutes compared to the standard morphine. In this study, indomethacin and its complexes with cobalt, copper and manganese showed mild antimicrobial activity and the indomethacin-manganese complex also displayed highest cytotoxicity with a lowest LC50 1.222 ± 0.21 ?g/ml and indomethacin-cobalt, indomethacin-copper and indomethacin-zinc had significant LC50 of 1.549 ± 0.39 ?g/ml, 1.662 ± 0.17 ?g/ml and 1.903 ± 0.64 ?g/ml, respectively where standard vincristine sulphate had LC50 of 0.824 ± 0.04 ?g/ml. The complex of indomethacin with cobalt, copper, manganese and zinc revealed % of inhibition 38.46 ± 1.03, 64.31 ± 0.21, 46.71 ± 0.46 and 30.79 ± 0.30, respectively and also had significant IC50 of 17.51 ± 0.62 ?g/ml, 12.31 ± 0.58 ?g/ml, 15.71 ± 0.16 ?g/ml and 19.84 ± 0.08 ?g/ml correspondingly. This study indicates that the complexes of indomethacin had analgesic, antimicrobial, cytotoxic and antioxidant activities which could be subjected for further therapeutic evaluation. DOI: http://dx.doi.org/10.3329/dujps.v13i2.21895 Dhaka Univ. J. Pharm. Sci. 13(2): 175-180, 2014 (December)

APA, Harvard, Vancouver, ISO, and other styles

37

Li, Y., S. H. Yang, C. B. Tang, Y. M. Chen, J. He, and M. T. Tang. "Reductive-sulfurizing smelting treatment of smelter slag for copper and cobalt recovery." Journal of Mining and Metallurgy, Section B: Metallurgy 54, no. 1 (2018): 73–79. http://dx.doi.org/10.2298/jmmb160315049l.

Full text

Abstract:

Recovery of copper and cobalt from smelter slag using reductive-sulfurizing smelting method was performed in this study. The effects of reductive agent (coke), sulfurizing agent (pyrite), slag modifier (CaO) and smelting temperature and duration on the extractive efficiencies of Cu, Co and Fe were discussed. The phase compositions and microstructure of the materials, copper-cobalt matte and cleaned slag were determined. The results showed that copper and cobalt contents in cleaned slag could decrease averagely to 0.18% and 0.071% respectively after cleaning. 91.99% Cu and 92.94% Co and less than 38.73% Fe were recovered from the smelter slag under the optimum conditions: 6 wt.% coke, 20 wt.% pyrite and 6 wt.% CaO addition to the smelter slag, smelting temperature of 1350?C and smelting duration of 3h. The addition of CaO can increase the selectivity of Co recovery. The cleaning products were characterized by XRD and SEM-EDS analysis. The results showed that the main phases of copper-cobalt matte were iron sulfide (FeS), geerite (Cu8S5), iron cobalt sulfide (Fe0.92Co0.08S) and Fe-Cu-Co alloy. The cleaned slag mainly comprised fayalite (Fe2SiO4), hedenbergite (CaFe(Si2O6)) and magnetite (Fe3O4).

APA, Harvard, Vancouver, ISO, and other styles

38

Leznoff, Clifford C., Sebastian M. Marcuccio, Shafrira Greenberg, A. B. P. Lever, and Kenneth B. Tomer. "Metallophthalocyanine dimers incorporating five-atom covalent bridges." Canadian Journal of Chemistry 63, no. 3 (1985): 623–31. http://dx.doi.org/10.1139/v85-102.

Full text

Abstract:

Metal-free copper and cobalt(II) binuclear phthalocyanines, in which the two phthalocyanine nuclci are covalently linked through five-atom bridges, have been prepared and characterized. Some new metal-free, copper, cobalt(II), and zinc 2,9,16,23-tetraalkoxyphthalocyanines, some of which are extremely soluble in organic solvents, are described.

APA, Harvard, Vancouver, ISO, and other styles

39

Knaislová, Anna, Hong Vu, and Petr Dvořák. "Microwave and Ultrasound Effect on Ammoniacal Leaching of Deep-Sea Nodules." Minerals 8, no. 8 (2018): 351. http://dx.doi.org/10.3390/min8080351.

Full text

Abstract:

The influence of ultrasound and microwaves on extraction of copper, nickel, and cobalt from manganese deep-sea nodules by reductive ammoniacal leaching in the presence of ammonium thiosulfate as a reducing agent was studied. The ultrasonic ammoniacal leaching provides higher metals extraction, while the effect of microwaves on the metals extraction under the studied leaching conditions is insignificant. In general, increasing leaching temperature increases significantly extraction of the metals of interest. At high temperatures, extraction efficiencies of copper, nickel, and cobalt decrease over longer leaching duration as a result of decomposition of the metals amino-complexes and reverse precipitation of metals. However, during the ultrasonic leaching at a temperature of 85 °C, the extraction of nickel remains almost unchanged over longer leaching durations and does not follow the decreasing course, observed in the extraction of copper and cobalt. The finding suggests that nickel can be selectively extracted from the nodules by the ultrasonic leaching. The maximal extraction efficiency of copper, nickel, and cobalt was 83%, 71%, and 32%, respectively, when the reductive ultrasonic ammoniacal leaching was carried out at 85 °C for 90 min. In the presence of microwaves, the maximal extraction efficiency of copper, nickel, and cobalt was 67%, 48%, and 8%, respectively, when the reductive ultrasonic ammoniacal leaching was carried out at the output power of 60 W for 210 min.

APA, Harvard, Vancouver, ISO, and other styles

40

K., C. SATAPAmY, C. DASH D., C. PRADHAN G., and NAIK A. "Cobalt(II), Nickel(II) and Copper(II) Complexes with N-Benzoyl- N ' -(1,3,4-thiadiazol-2- yl)thiocarbamide as Ligand." Journal of Indian Chemical Society Vol. 66, May 1988 (1989): 291–92. https://doi.org/10.5281/zenodo.5948709.

Full text

Abstract:

Department of Chemistry, Sambalpur University, Jyoti Vihar, Burla-768 017 Manuscript received 29 December 1987, revised 26 July 1988, accepted 22 February 1989 Complexes of N-benzoyl-N'-(1,3,4-thiadlazol-2-yl)thiocarbamide (L) of composition [ML2X2) where M -(oII, Nill, Cull; X-CI. Br, NO3, and CIO4, have been syn- thesised and characterised on the basis of elemental analysis, conductivity, magnetic and spectral data. The coordination of thiocarbonyl sulphur, carbonyl oxygen of thiocarbamide and the anions to the metal ion have been inferred. Ligand field parameters for the ColI and NilI complexes have also been calculated.

APA, Harvard, Vancouver, ISO, and other styles

41

Litvin, Valentina, Rostislav Galagan, and Dina Shepak. "BIMETAL/CARBON NANOCOMPOSITES CuCo@C BASED ON SYNTHETIC HUMIC ACIDS." Ukrainian Chemistry Journal 87, no. 4 (2021): 117–27. http://dx.doi.org/10.33609/2708-129x.87.04.2021.117-127.

Full text

Abstract:

The new original method for the synthesis of bimetal-carbon nanocomposites of copper and cobalt (CuCo@C) of various compositions using synthetic humic acid as a carbon source has been developed. The technique includes the synthesis of humates of copper and cobalt, preparation of their mixture and its pyrolysis in a hydrogen atmosphere. For characterize the final product, the methods of diffraction, cyclic voltammetry, and scanning electron microscopy were used. Comparison of diffractograms of bimetal nanocomposites shown two systems of reflexes from fcc structures, which correspond to metallic copper and cobalt. Diffractometric measurements also indicate the amorphous nature of the carbon matrix. Carrying out the pyrolysis of the metal humates in the reducing atmosphere afford remove almost completely the contained oxygen from the final product, partly in the form of CO2, partly in the form of water. Ions of the transition metal in these conditions are reduced to the metal atoms, forming nanoparticles surrounded by carbon. The formation of a carbon matrix metal around nanoparticles, on the one hand, can ensure their high thermal stability, and on the other hand, contributes to the stabilization of metal nanoparticles and prevents their aggregation. The size of cobalt nanoparticles in nanocomposites varies from 35 to 54 nm, and copper nanoparticles - from 56 to 88 nm, depending on the ratio used in the synthesis of metal humates. It was found that nanoparticles of an alloy of these metals (alpha-cobalt phase) are formed in nanocomposites containing 20% copper and 80% cobalt. Cyclic voltammogrames of bimetallic nanocomposites indicate the presence of dead pores in their composition. It has been established by scanning electron microscopy that in the case of an excess amount of copper in the nanocomposites, spherical formations about 1000 nm in size with faceting signs are formed. As part of the «bottom up» concept proposed a three-stage model of formation.

APA, Harvard, Vancouver, ISO, and other styles

42

Ficker, Mario, Johannes F. Petersen, Tina Gschneidtner, et al. "Being two is better than one—catalytic reductions with dendrimer encapsulated copper- and copper–cobalt-subnanoparticles." Chemical Communications 51, no. 49 (2015): 9957–60. http://dx.doi.org/10.1039/c5cc00347d.

Full text

APA, Harvard, Vancouver, ISO, and other styles

43

Wei, J. M., W. W. Wang, M. S. Ma, et al. "Recovery of Scandium, Nickel and Cobalt from Hydrometallurgical Waste of Laterite." Journal of Physics: Conference Series 2686, no. 1 (2024): 012004. http://dx.doi.org/10.1088/1742-6596/2686/1/012004.

Full text

Abstract:

Abstract Recovery of new-energy critical metals including scandium, nickel and cobalt as well as copper and zinc from a neutralization residue produced in laterite hydrometallurgical process has been studied. Effect of leaching parameters such as acid consumption, solution pH and temperature has been investigated. It was found that scandium, nickel, cobalt and copper could be recovered at high efficiencies from the residues by selective leaching using sulphuric acid solutions under ambient conditions, while the co-leaching of impurities including iron, aluminium and silicon was low under the optimal conditions. The nickel, cobalt, copper and zinc in the leaching solution could be further concentrated into mixed sulphides and separated from impurities by sulphide precipitation.

APA, Harvard, Vancouver, ISO, and other styles

44

Bradberry, Sally M. "Metals (cobalt, copper, lead, mercury)." Medicine 44, no. 3 (2016): 182–84. http://dx.doi.org/10.1016/j.mpmed.2015.12.008.

Full text

APA, Harvard, Vancouver, ISO, and other styles

45

Henderson, Lucas B., and John G. Ekerdt. "Chemically capping copper with cobalt." Microelectronic Engineering 87, no. 4 (2010): 588–92. http://dx.doi.org/10.1016/j.mee.2009.08.017.

Full text

APA, Harvard, Vancouver, ISO, and other styles

46

Mentar, L., M. R. Khelladi, A. Azizi, G. Schmerber, and A. Dinia. "Electrocrystallisation of cobalt, copper and cobalt–copper alloys on fluorine-doped tin oxide electrodes." Transactions of the IMF 89, no. 3 (2011): 143–50. http://dx.doi.org/10.1179/174591911x13013911711888.

Full text

APA, Harvard, Vancouver, ISO, and other styles

47

Korchagin, Vladimir I., Alena M. Surkova, Lubov N. Studenikina, and Artem V. Protasov. "INFLUENCE OF PROOXIDANT NATURE ON EVOLUTION OF FORMALDEHYDE FROM OXO-DEGRADABLE POLYETHYLENE." IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENII KHIMIYA KHIMICHESKAYA TEKHNOLOGIYA 62, no. 2 (2019): 101–7. http://dx.doi.org/10.6060/ivkkt.20196202.5804.

Full text

Abstract:

In the article, methods of oxo-destruction of polyethylene modified with pro-oxidants of various nature are considered taking into account ecotoxicological aspects. A comparative evaluation of the indexes of degradation of polyethylene under the influence of air oxygen under accelerated thermal aging and under natural conditions is presented. It was revealed that the degradation index rises in the series "iron <copper <cobalt". The amount of formaldehyde in the gas-air extraction of oxo-degradable polyethylene modified with iron, cobalt and copper stearate is determined with accelerated thermal-oxidative degradation. The degree of isolation of formaldehyde increases in the series "copper <iron <cobalt", which indicates different periods of induction of the degradation process initiated by prooxidates, as well as the presence of side processes that affect the depth of destructive processes. It has been established that a polyethylene film modified with cobalt stearate contributes to the increase in formaldehyde emissions, while the formaldehyde content in the gas phase is 0.065 mg / m3 (per 1 g of sample), which exceeds MAC m.o.t by 1.3 times. The content of formaldehyde precipitates in the gas phase is reduced by 3.25 times, with the use of ferrous sterate. Individual carcinogenic risks (ICR) for oxo-degradable films based on iron, copper and cobalt stearates are predicted to equal 6.593·10-5, 5.595·10-5 2.864·10-4, respectively. A comparative analysis of prooxidants allows us to conclude that the use of iron and copper stearates contributes to a slower degradation of polyethylene and reduces its ecotoxicological hazard, the use of cobalt based pro-oxidants contributes to a faster and deeper destruction, but is accompanied by increased release of formaldehyde in the oxodegradation of modified polyethylene. Of interest is the further study of complex prooxidants on the basis of iron with trace amounts of cobalt as highly effective and environmentally friendly modifiers of polyolefins, contributing to their accelerated oxidation in the environment, as well as the development of technical solutions to reduce the risk in the case of cobalt stearate as an effective prooxidant.

APA, Harvard, Vancouver, ISO, and other styles

48

Tijsseling, Laurens T., Quentin Dehaine, Gavyn K. Rollinson, and Hylke J. Glass. "Mineralogical Prediction of Flotation Performance for a Sediment-Hosted Copper–Cobalt Sulphide Ore." Minerals 10, no. 5 (2020): 474. http://dx.doi.org/10.3390/min10050474.

Full text

Abstract:

As part of a study investigating the influence of mineralogical variability in a sediment hosted copper–cobalt deposit in the Democratic Republic of Congo on flotation performance, the flotation of nine sulphide ore samples was investigated through laboratory batch kinetics tests and quantitative mineral analyses. Using a range of ore samples from the same deposit the influence of mineralogy on flotation performance was studied. Characterisation of the samples through QEMSCAN showed that bornite, chalcopyrite, chalcocite and carrollite are the main copper-bearing sulphide minerals while carrollite is the only cobalt-bearing mineral. Mineralogical characteristics were averaged per sample to allow for a quantitative correlation with flotation performance parameters. Equilibrium recoveries, rate constants and final grades of the samples were correlated to the feed mineralogy through Multiple Linear Regression (MLR). Target sulphide minerals content and particle size, magnesiochlorite content, carrollite liberation and association of the copper and cobalt minerals with magnesiochlorite and dolomite were used to predict flotation performance. Leave One Out Cross Validation (LOOCV) revealed that the final copper and cobalt grades are predicted with an R2 of 0.80 and 0.93 and Root Mean Square Error of Cross Validation (RMSECV) of 4.41% and 1.34%. The recovery of cobalt and copper with time can be predicted with an R2 of 0.94 for both and an overall test error of 4.70% and 5.14%. Overall, it was shown that quantitative understanding of changes in mineralogy allows for prediction of changes in flotation performance.

APA, Harvard, Vancouver, ISO, and other styles

49

Panicker, S., A. Mathew, S. Dalvi, and M. Chattaraj. "Medicinal Properties of Cobalt and Copper Nanoparticles Synthesized Using Limonia acidissima Leaf Extract." Biotechnology Journal International 28, no. 2 (2024): 36–45. http://dx.doi.org/10.9734/bji/2024/v28i2717.

Full text

Abstract:

Aim: The present investigation was undertaken to synthesize Cobalt and copper nanoparticles (NPs) using Limonia acidissima L. leaf extract and to test their few medicinal properties like antimicrobial antioxidant and anti-diabetic activities. Methodology: Limonia acidissima plant leaves were collected from the vicinity of the College and the study was completed in 11 months. The hot aqueous leaf extract and soxhlet extract using ethyl acetate as solvent were prepared. Phytochemical analysis of the leaf extract showed the presence of Tannins, Flavonoids, Alkaloids and absence of Phenols. The leaf extract was then used to make Cobalt and copper nanoparticles (NPs) using Cobalt acetate and Copper sulphate respectively. Results: The formation of NPs was checked by color change and confirmed with UV–visible spectrophotometry. The typical peaks of Co-NPs were detected in the range of maximum wavelength between 380-520 nm and that for Cu NPs was detected between 260-580 nm. The antimicrobial activity of the synthesized NPs of both metal oxides was then tested against Gram positive and Gram negative bacteria and also against two Candida sps. Cobalt NPs exhibited strong antimicrobial activity against all tested organisms but Copper NPs showed no antimicrobial activity. The both NPs were also tested for antioxidant and anti-diabetic properties. Comparatively the Copper NPs possessed higher antioxidant and anti-diabetic activity than the cobalt nanoparticles. Conclusion: Thus, this underutilized plant from India can be further exploited for more medicinal properties and bring it into pharmaceutical usage.

APA, Harvard, Vancouver, ISO, and other styles

50

Seo, Min, Min Kyung Cho, Un Hyeon Kang, Sin Young Jeon, Sang-Ho Lim, and Seung Hee Han. "Low-Resistivity Cobalt and Ruthenium Ultra-Thin Film Deposition Using Bipolar HiPIMS Technique." ECS Journal of Solid State Science and Technology 11, no. 3 (2022): 033006. http://dx.doi.org/10.1149/2162-8777/ac5805.

Full text

Abstract:

Owing to the rapid growth of very large-scale integration technology at nanometer scales, cobalt and ruthenium interconnects are being used to solve the high-resistivity copper problem. However, with such interconnects, carbon contamination can occur during chemical vapor deposition and atomic layer deposition. Bipolar (BP) high-power impulse magnetron sputtering (HiPIMS) with a high ionization rate is an excellent vacuum process for depositing low-resistivity thin films. In this study, low-resistivity cobalt, ruthenium, and copper thin films were deposited using BP-HiPIMS, HiPIMS, and direct-current magnetron sputtering (DCMS). The resistivities of the cobalt, ruthenium, and copper thin films (<10 nm) deposited via BP-HiPIMS were 91.5, 75, and 35%, respectively, lower than the resistivities of the same film materials deposited using direct-current MS. To solve the low pass-through flux of cobalt, the target temperature was raised to the Curie temperature (approximately 1100 °C) using a thermal insulation backplate (Ti-6Al-4V), resulting in a resistivity reduction of about 73%. The study provides a novel method for the vacuum deposition of cobalt and ruthenium thin films.

APA, Harvard, Vancouver, ISO, and other styles

Journal articles on the topic 'Cobalt and copper'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles