Copper Dioxide Research Articles

Non-similar analysis of heat generation and thermal radiation on Eyring-Powell Hybrid nanofluid flow across a stretching surface

This paper portrays a two-dimensional mathematical model developed for the analysis of Eyring-Powell hybrid nanofluid flow, incorporating variable temperature and velocity profiles. This study investigates the flow through a porous media with a mixture of hybrid nanoparticles (copper dioxide, magnetite) integrated into ethylene glycol ([Formula: see text]) across a stretching sheet. The model takes magnetic effects, heat generation, and thermal radiation into account. Additionally, nonsimilar partial differential equations (PDEs) are transformed into ordinary differential equations using the local nonsimilarity approach. These equations are then numerically solved using the built-in Matlab function bvp4c. To examine the effects of adjusting parameters on heat, mass transfer, and skin friction, the results are displayed graphically. With an increase in the given values of magnetic field [Formula: see text], the velocity profile [Formula: see text] is seen to decay. Moreover, it is observed that the hybrid nanofluid density and dynamic viscosity increase as the volume fraction rises. It is estimated that the thermal conductivity and viscosity of the [Formula: see text] hybrid nanofluid are expected to increase to 4.1% and 12.35%, respectively, and to 71.55% and 78.01%, respectively, for volume concentrations ranging from 0.02% to 0.05%. It is also concluded that the local skin-friction coefficient has the opposite trend while the local Nusselt number rises monotonically with both the slip velocity parameter and the surface convection parameter. This research has broad applications In the glass and polymer industries, metallic plate cooling, plastic sheet contractions, etc.

Peristaltic pumping of hybrid nanofluids through an inclined asymmetric channel: A biomedical application

This analysis addresses the application of highly effective nanomaterials namely single walled carbon nanotubes, copper dioxide and titanium dioxide in medical field from different aspects. The nanomaterials are brought into consideration with aiming to focus heat transfer enhancement of base liquid. Further the characteristics of nanomaterials are compared in terms of single phase nanofluid and hybrid nanofluid models. This inspiration leads to mathematical modeling of the problem subjected to Sorret and Dufur effects. Convection phenomenon is used to investigate heat transfer at the walls of channel. The mathematical formulation has been performed in asymmetric inclined channel. The equations are simplified by using small Reynolds number and long wavelength estimation. The governing equations with associated boundary conditions are solved via Mathematica software. The non-dimensional variables appeared in equations are discussed against velocity, temperature, concentration, streamline, skin friction, Nusselt number and Sherwood number. The results are compared for single phase nanoliquid (SWCNTs+water) and hybrid nanofluid (Cu+TiO2) models against physical variables. Hybrid nanofluid model leads higher temperature against inclination angle and Dufur number. Opposite trend is noted for mass transport against Sorret number. Furthermore, heat transfer in case of hybrid nanofluid model is noted higher than single phase nanoliquid model. The considered nanomaterials could be useful to boost heat transfer rate for targeted maligned tissues. The current study will help researchers to investigate other nanomaterials that could be used effectively as an alternative in medical fields.

Experimental effect of CuO2 nanoparticles into the RME and EGR rates on NOX and morphological characteristics of soot nanoparticles

In recent years, the adding nano additives to the fuel is paid much attention by decreasing the exhaust emissions and enhance combustion characteristics without any modifications in diesel engine. The effects of copper dioxide (CuO2) nanoparticles and exhaust gas recirculation (EGR) on combustion characteristics and morphological characteristics of soot nanoparticles in diesel engine fuelled with rapeseed methyl ester (RME) were investigated in this study. The good advantages of CuO2 nanoparticles such as good thermal properties, oxygen storage, and density thermophysical properties of viscosity are encourage to using as nano additives into the biodiesel. The results showed that the pressure inside cylinder and ROHR improved by 4% and 11%, respectively, from adding CuO2 nanoparticles into the RME in comparison neat RME. Furthermore, the BTE increased by 3.64%, 7.36%, 9.28% and 12.43% with adding CuO2 to the RME, while the BSFC decreased by 5.26%, 7.47%, 9.68% and 12.73% when adding nanoparticles to the RME under 25%, 50%, 75% and 100% of engine load, respectively, in comparison with diesel fuel. Adding CuO2 nanoparticles to the RME and 20% rate of EGR significantly decrease the NOX emissions by 29.64% when compared to the without nano additives. The number and concentration of soot nanoparticles were decreased with addition of CuO2 nanoparticles to the RME and they increased with presence EGR technology. It is indicated that the soot nanoparticles concentration decreased or was in par with neat RME when incorporation between EGR and nano additives. The morphological parameters such as number of soot primary particles (npo) exhibits significant reduction by 18%, meanwhile slightly increase in the average diameter of soot primary particles (dpo) by 7% with adding CuO2 to the RME for with and without EGR.

CuO and MWCNTs Nanoparticles Filled PVA–PVP Nanocomposites: Morphological, Optical, Thermal, Dielectric, and Electrical Characteristics

Copper dioxide (CuO) nanoparticles and Multiwall carbon nanotubes (MWCNTs) filled poly(vinyl alcohol) (PVA) and poly(vinyl pyrrolidone) (PVP) blend matrix (50/50 wt%) based polymer nanocomposites (PNCs) (i.e., PVA/PVP:(15-x)CuO(x)MWCNTs for x = 0,1,5,7.5, 10,14, and 15wt%) have been prepared employing the solution-cast method. The morphologies of these PNCs are semicrystalline, according to an X-ray diffraction investigation. The FTIR, SEM, and AFM measurements of PNCs were used to investigate the development of the miscible mix, polymer-polymer and polymer–nanoparticle interactions, and the influence of CuO and MWCNTs nanofillers on the morphology aspects on the main chain of PVA/PVP blend. The nanofiller dispersion signposting for x = 14 wt% nanoloading in the PVA–PVP blend matrix significantly enhances the crystalline phase, diminishing the optical energy gap to 2.31 eV. The DC conductivity values augment with the upsurge in nanofiller level for maximum x = 14 wt%. The dielectric and electrical characteristics of these PNCs are investigated for an applied frequency range from 1 kHz to 1 MHz. The enhancement in the nanofiller level upto x = 14 wt% in the PVA/PVP matrix leads to the development of percolating network through the PNCs. These factors boost the dielectric permittivity values substantially, owing to the decrease in the nano-confinement phenomenon. The rise in applied frequency reduces dielectric permittivity and impedance values and enhances ac electrical conductivity. These PNCs having good dielectric and electrical characteristics can be used as frequency tunable nanodielectric material in electronic devices.

Transcriptomic changes in green bean pods against grey mould and white rot diseases via field application of chemical elicitor nanoparticles.

The authors tested the efficacy of two salt nanoparticles (NPs), namely, copper dioxide (CuO) and tri-calcium phosphate [Ca3(PO4)2] to induce resistance in green bean pods against grey mould and white rot diseases caused by Botrytis cinerea and Sclerotinia sclerotiorum, respectively. High amounts of phytoalexins, kievitone, coumestrol, phaseollidin, 6-ά-hydroxyphaseollin, and phaseollin, were detected in naturally infected and artificially inoculated green bean pods in response to the tested NPs. Green bean plants treated in the field with CuO and Ca3(PO4)2 NPs had the highest mRNA quantity of all the studied defence genes, receptor-like kinase (PvRK20), pathogenesis-related protein (PR1), 1,3-β-D-glucanase (pvgluc), polygalacturonase inhibitor protein (PvGIP), and alpha-dioxygenase (a-DOX) than that of the control group. CuO NPs followed by Ca3(PO4)2 NPs at 0.15 mg ml-1 were the most potent in increasing the transcriptomic levels of pk20, DOX, PR1, PvGIP, and pvgluc. Field applications of both chemical elicitor NPs exhibited a non-genotoxic effect on the Paulista green bean DNA using eight ISSR primers. The field application of the studied NPs could effectively extend the shelf life of green bean pods by up to 21 days at 7 ± 1°C during marketing and export due to its potent effect against grey mould and white rot diseases.

Thermal oxidation effects on physical properties of CuO2 thin films for optoelectronic application

In this research, high quality copper dioxide (Cu2O) and copper oxide (CuO) thin films have been prepared using RF sputtering method under ranges of annealing temperatures. The results showed that high transparent samples along with increasing the annealing temperatures. As the annealing temperature increases, the transparency values increases from 48% to 68%. At low annealing temperature, however, optical properties drops sharply. It has been found that the value of energy band-gap were 2.35 eV–2.62 eV as the annealing temperature increases. Further, SEM and x-ray Diffraction techniques were used to measure and investigate the surface morphology and the homogeneity of Cu2O and CuO thin films, respectively.

Effects of CuO nanoparticles on Lemna minor.

BackgroundCopper dioxide nanoparticles (NPs), which is a kind of important and widely used metal oxide NP, eventually reaches a water body through wastewater and urban runoff. Ecotoxicological studies of this kind of NPs effects on hydrophyte are very limited at present. Lemna minor was exposed to media with different concentrations of CuO NPs, bulk CuO, and two times concentration of Cu2+ released from CuO NPs in culture media. The changes in plant growth, chlorophyll content, antioxidant defense enzyme activities [i.e., peroxidase (POD), catalase (CAT), superoxide dismutase (SOD) activities], and malondialdehyde (MDA) content were measured in the present study. The particle size of CuO NPs and the zeta potential of CuO NPs and bulk CuO in the culture media were also analyzed to complementally evaluate their toxicity on duckweed.ResultResults showed that CuO NPs inhibited the plant growth at lower concentration than bulk CuO. L. minor roots were easily broken in CuO NPs media under the experimental condition, and the inhibition occurred only partly because CuO NPs released Cu2+ in the culture media. The POD, SOD, and CAT activities of L. minor increased when the plants were exposed to CuO NPs, bulk CuO NPs and two times the concentration of Cu2+ released from CuO NPs in culture media, but the increase of these enzymes were the highest in CuO NPs media among the three kinds of materials. The MDA content was significantly increased compared with that of the control from 50 mg L−1 CuO NP concentration in culture media.ConclusionCuO NPs has more toxicity on L. minor compared with that of bulk CuO, and the inhibition occurred only partly because released Cu2+ in the culture media. The plant accumulated more reactive oxygen species in the CuO NP media than in the same concentration of bulk CuO. The plant cell encountered serious damage when the CuO NP concentration reached 50 mg L−1 in culture media. The toxicology of CuO NP on hydrophytes must be considered because that hydrophytes are the basic of aquatic ecosystem.

Growth and enzymatic activity of maize (Zea mays L.) plant: Solution culture test for copper dioxide nano particles

ABSTRACTCopper (Cu) is an essential micronutrient for plants, which acts either as the metal component of enzymes or as a functional structural or a regulatory co-factor of a large number of enzymes. To understand the possible benefits of applying nanotechnology to agriculture, the first step should be to analyze penetration and transport of nano-particles in plants. The present study was conducted to test the hypothesis that copper nanoparticle would enter into the plant cell and govern the growth of maize plant.A solution culture experiment was conducted to investigate the effect of Cu nano-particles (<50nm) on the growth and enzymatic activity of maize (Zea mays L.) plant. Bioaccumulation of Cu nano-particles in plant was also investigated. Results showed that Cu nano-particles can enter into the plant cell through roots and leaves. Bioaccumulation increased with increasing concentration of Cu nano-particles (NPs), and agglomeration of particles was observed in the cells using transmission-electron microscopy. Application of Cu nano-particles through solution culture as well as spray enhanced the growth (51%) of maize plant in comparison to control. The different enzymatic activities like glucose-6-phosphate dehydrogenase, succinate dehydrogenase, superoxide dismutase, catalase, andguaiacol peroxidase were studied to find a possible pathway through which NPs may affect the enzymatic activity of plant. Amongst the enzymes, the activity of glucose-6-phosphate dehydrogenase was highly influenced by copper oxide (CuO)nano-particles application by spray as well as in solution. Experimental results revealed that CuOnano-particles affected the pentose phosphate pathway of maize plant. The obtained experimental results provided conclusive evidence to indicate that the nano-particles considered under this study could enter into the plant cell, easily be assimilated by plants and also enhanced its growth by regulating the different enzyme activities.

Electromagnetic interference shielding, mechanical properties and water absorption of copper/bamboo fabric (Cu/BF) composites

Copper/bamboo fabric (Cu/BF) composites were prepared by electroless deposition via a tin-free process. The process involved 3-aminopropyltrimethoxysilane modification, noble metal (Au or Pd) activation and electroless copper planting of BF. The copper deposition rate via Pd catalytic process was 1.01mg/cm2h, higher than that by Au catalytic process (0.85mg/cm2h). The microstructure of Cu/BF composites was analyzed by scanning electron microscopy (SEM), and the copper coatings were composed of ball-shaped copper particles. The composition and chemical state of copper layers were measured by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) spectra, Cu0 was detected but copper dioxide was not found in both spectra. The electromagnetic interference, water absorption, mechanical tension, conductivity and adhesion properties of Cu/BF samples (weight ratio of Cu/BF: 0.36±0.01) were measured to obtain the qualities of the composites.

Systematic Study of Oxo, Peroxo, and Superoxo Isomers of 3d-Metal Dioxides and Their Anions

The electronic and geometrical structures of the ground and excited states of the 3d-metal dioxides ScO2, TiO2, VO2, CrO2, MnO2, FeO2, CoO2, NiO2, CuO2, and ZnO2 along with their singly charged negative ions have been calculated using the density functional theory with generalized gradient approximation for the exchange-correlation potential. We have considered oxo, peroxo, and superoxo isomers in both neutral and anionic series. The ground states of all 3d-metal dioxides and their anions possess oxo forms, except for copper dioxide, which prefers a superoxo form. All the dioxides have a large number of isomers closely spaced in total energy. The champion, FeO2-, possesses five isomers within an energy range of 0.35 eV. The energy gap between oxo, peroxo, and superoxo isomers decreases along the series from TiO2 to ZnO2. ScO2 has peroxo and superoxo isomers which are close in total energy to its oxo ground state. The electron affinities are computed for all types of isomers and are compared to available e...

Two isomers of CuO2: The Cu(O2) complex and the copper dioxide

Photoelectron spectroscopy of CuO−2 has been studied at three detachment wavelengths: 532 nm, 355 nm, and 266 nm. Vibrationally resolved spectra for two distinct isomers are observed: the Cu(O2) complex and the copper dioxide molecule. The Cu(O)2 complex has an electron affinity (EA) of 1.503 (10) eV with a ground state vibrational frequency of 530 (50) cm−1. Its first electronic excited state is 7400 (300) cm−1 above the ground state. The Cu(O2)− anion is also observed to undergo photodissociation to Cu−+O2 at both 532 nm and 355 nm detachment wavelengths. The copper dioxide molecule is found to have a high EA of 3.46 (4) eV. Three low-lying excited states are observed within 1 eV above the ground state. The first two excited states of the copper dioxide molecule both possess a totally symmetric vibrational frequency of 640 (60) cm−1.

Determination of the structure and bond energies of nickel dioxide and copper dioxide

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTDetermination of the structure and bond energies of nickel dioxide and copper dioxideCharles W. Bauschlicher Jr., Stephen R. Langhoff, Harry Partridge, and Mariona SodupeCite this: J. Phys. Chem. 1993, 97, 4, 856–859Publication Date (Print):January 1, 1993Publication History Published online1 May 2002Published inissue 1 January 1993https://doi.org/10.1021/j100106a010RIGHTS & PERMISSIONSArticle Views270Altmetric-Citations49LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (536 KB) Get e-Alerts

Electronic structure of the linear form of OCuO

The low-lying doublet states of the linear form of the copper dioxide molecule, OCuO, are investigated by the use of ab initio CASSCF (complete active space self-consistent field) and POLCI (polarization configuration interaction) calculations. The emission bands experimentally observed are discussed in terms of the calculated excitation energies of the dipole-allowed transitions from the 2Π g ground state.

ChemInform Abstract: Ab Initio Calculation of the Electronic Structure of Copper Dioxide

Chemischer InformationsdienstVolume 17, Issue 17 Physical Inorganic Chemistry ChemInform Abstract: Ab Initio Calculation of the Electronic Structure of Copper Dioxide T.-K. HA, T.-K. HASearch for more papers by this authorNGUYEN MINH THO NGUYEN MINH THO, NGUYEN MINH THO NGUYEN MINH THOSearch for more papers by this author T.-K. HA, T.-K. HASearch for more papers by this authorNGUYEN MINH THO NGUYEN MINH THO, NGUYEN MINH THO NGUYEN MINH THOSearch for more papers by this author First published: April 29, 1986 https://doi.org/10.1002/chin.198617002Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume17, Issue17April 29, 1986 RelatedInformation

An ab initio calculation of the electronic structure of copper dioxide

An ab initio calculation of the electronic structure of copper dioxide

Scientific Serials

American Journal of Science, November.—The higher oxides of copper, by Thomas B. Osborne. The oxides here dealt with are copper dioxide and copper sesquioxide; but being unable to continue the subject, at least for some time, the author publishes the incomplete results so far obtained, in the hope that they may be of use to others wishing to continue this line of investigation.—The structure of the Triassic formation of the Connecticut Valley, by William Morris Davis. It is shown that disturbance has taken place after the period of deposition; that it was not caused by overflow or intrusion of trap-sheets; that it was not a simple monoclinal tilting; and that there is evidence for occurrence of unseen faults. The probable character of the disturb ing force, its action on the fundamental schists, with consequent monoclinal faulting of overlying Triassic strata, and generally the area and depth of the disturbance, are questions also discussed in this elaborate paper.—Researches on the lithia micas, by F. W. Clarke. Descriptions and exhaustive analyses are given of the lepidolites of Rumford, Hebron, Auburn, and other parts of Maine, and of the iron-lithia micas of Rockfort granitequarries near Cape Ann, Massachusetts.—The thickness of the ice in North-Eastern Pennsylvania during the Glacial epoch, by John C. Branner. So far from rising only 2200 feet above sea-level, as hitherto supposed, the ice is shown to have covered the twin peaks of Elk Mountain (2700 and 2575 feet), and no doubt also the Sugar Loaf, Ararat, and the other loftiest summits of this region during the Glacial epoch. A sheet of ice 1500 feet or less in thickness could never have flowed across such a mountainous region, so regardless as the great glacier was of its marked topographical features.—On the time of contact between the hammer and string in a piano, by Charles K. Wead. Owing to the uncertainty attending the theory developed by Helmholtz regarding the action of the hammer on a piano-string, the author has attempted to measure directly the time of contact by a simple process with results here tabulated.—Photographic determinations of stellar positions, by B. A. Gould. This is a reprint of the paper presented at the late Buffalo meeting of the American Association, and containing a brief history of stellar photography, and of the results so far obtained by the author in this department of practical astronomy.—Lucasite, a new variety of vermiculite, by Thomas M. Chatard. A description and full analysis is given of this substance, specimens of which have been found associated with corundum at Corundum Hill, Macon County, North Carolina. It has been named lucasite in honour of Dr. H. S. Lucas, so well known in connection with the Chester emery mine, Massachusetts.—Crystallographic notes, by W. G. Brown. An account is given of certain artificial copper crystals, of artificial crystallised cuprous oxide (cuprite), and of crystallised lead carbonate (cerussite) found under circumstances here described.—On the chemical composition of ralstonite, by S. L. Penfield and D. N. Harper. A comparative table is given of the analyses made by Nordenskjöld, Penfield, and Brandle of this rare mineral, which was found associated with thomsenolite at Arksuk Fjord, Greenland.—Analyses of the thomsenolite by the same chemists.—Mineralogical notes, by Edward S. Dana. Descriptive analyses are given of columbite from Standish, Maine, of diaspore from Newlin, Pennsylvania, of zincite from Stirling Hill, New Jersey, and of some native sulphur from Rabbit Hollow, Nevada, interesting because of its complex crystalline form.