Increasing Copper Content Research Articles

Hydrothermally synthesized nickel copper phosphate thin film cathodes for high-performance hybrid supercapacitor devices

Transition metal phosphate (TMP) based materials are developing as advanced type electrode materials for hybrid supercapacitors (SCs) due to their unprecedented conductivity, and rich redox activity. Attracted by these fabulous physicochemical characteristics of metal phosphates, binder-free nickel copper (Ni-Cu) phosphate thin films directly grown on stainless steel (SS) substrate by hydrothermal method. The morphological alteration from microplates like nickel phosphate to microrods like copper phosphate is detected with increasing copper content in Ni-Cu phosphate thin films. The optimal 1:1 ratio of nickel and copper in Ni-Cu phosphate (Ni1.62Cu1.35(PO4)2·H2O) thin film illustrates high specific capacitance (Cs) (capacity (Cc)) of 711 F g−1 (355.5 C g−1) at 1.5 A g−1. More significantly, a hybrid aqueous SC (HASC) and all-solid-state SC (HASSC) electrochemical energy storage devices (ESDs) have been fabricated. The HASC device showed superior Cs (85 F g−1 at 0.8 A g−1) with specific energy (SE) of 30 Wh kg−1 at 1.27 kW kg−1 specific power (SP). Additionally, HASSC device offers a higher Cs (52 F g−1 at 0.6 A g−1) with 18.53 Wh kg−1 SE at 1.64 kW kg−1 SP. Also, both HASC and HASSC devices exhibit excellent long-term durability of 84.81 and 80.83 %, respectively, after 5000 GCD cycles. Moreover, HASSC device brightens a panel of 201 red light-emitting diodes (LEDs) illustrating its commercial practicability to next-generation hybrid energy storage devices.

Copper Monitoring in Vineyard Soils of Central Italy Subjected to Three Antifungal Treatments, and Effects of Sub-Lethal Copper Doses on the Earthworm Eisenia fetida.

The extensive employment of copper-based fungicides has increased copper concentration in vineyard soils. The present study’s objectives were to monitor copper concentration in two vineyard soils during two cropping seasons and study the ecotoxicological effects on the earthworm Eisenia fetida. Total, soluble, and bioavailable copper fractions were measured at the end of two cropping seasons and different depths in two vineyards of central Italy, characterised by three anticryptogamic control methods: copper compounds, chitosan, and combined treatments of them. A laboratory experiment to assess the effects on Eisenia fetida was conducted with soil samples collected in the vineyards with a mean copper concentration of 60 mg/kg and two higher concentrations of 90 and 150 mg/kg. Results showed low levels of total copper concentration in the first 20 cm of soils, regardless of antifungal treatment, highlighting prudent management of the vineyards under study, but the soluble fractions showed a significant increase in all samples during the two cropping seasons. At the dose of 150 mg/kg, earthworms suffer during the first two days, showing weight loss and DNA damage, but they are able to recover until day 28, showing no permanent harm at this copper concentration in soil.

Ambient Availability of Amino Acids, Proteins, and Iron Impacts Copper Resistance of Aspergillus fumigatus

The transition metals iron and copper are required by virtually all organisms but are toxic in excess. Acquisition of both metals and resistance to copper excess have previously been shown to be important for virulence of the most common airborne human mold pathogen, Aspergillus fumigatus. Here we demonstrate that the ambient availability of amino acids and proteins increases the copper resistance of A. fumigatus wild type and particularly of the ΔcrpA mutant that lacks export-mediated copper detoxification. The highest-protecting activity was found for L-histidine followed by L-asparagine, L-aspartate, L-serine, L-threonine, and L-tyrosine. Other amino acids and proteins also displayed significant but lower protection. The protecting activity of non-proteinogenic D-histidine, L-histidine-mediated growth inhibition in the absence of high-affinity copper uptake, determination of cellular metal contents, and expression analysis of copper-regulated genes suggested that histidine inhibits low-affinity but not high-affinity copper acquisition by extracellular copper complexation. An increase in the cellular copper content was found to be accompanied by an increase in the iron content, and, in agreement, iron starvation increased copper susceptibility, which underlines the importance of cellular metal balancing. Due to the role of iron and copper in nutritional immunity, these findings are likely to play an important role in the host niche.

New Composite Hydrogel Based on Whey and Gelatin Crosslinked with Copper Sulphate.

By-products from the meat and dairy industries are important sources of high biological value proteins. This paper explores possibilities for improving the swelling and integrity of a cross-linked whey and gelatin hydrogel with different amounts of CuSO4 × 5H2O. Overall, swelling tests demonstrate that cross-linked samples show a better hydration capacity and stability in the hydration medium, but different copper concentrations lead to different swelling behavior. At concentrations smaller than 0.39%, the sample lasts for 75 h in a water environment before beginning to disintegrate. At a concentration of copper sulphate higher than 0.55%, the stability of the sample increased substantially. The swelling kinetics has been investigated. The diffusion constant values increased with the increase in copper concentration, but, at the highest concentration of copper (0.86%), its value has decreased. Spectroscopy analyses such as Fourier transform infrared (FT-IR), X-ray diffraction (XRD), ultraviolet-visible spectroscopy (UV-VIS), and nuclear magnetic resonance (NMR) relaxometry analyses revealed changes in the secondary and tertiary structure of proteins as a result of the interaction of Cu2+ ions with functional groups of protein chains. In addition to its cross-linking ability, CuSO4 × 5H2O has also shown excellent antibacterial properties over common bacterial strains responsible for food spoilage. The result of this research demonstrates the potential of this hydrogel system as a unique material for food packaging.

H2S removal by copper enriched porous carbon cuboids

• Three porous structures based on carbon cuboids were synthesized. • All samples showed catalytic activity towards H 2 S besides acting as H 2 S sorbents. • H 2 S conversion increased with increasing surface area. • H 2 S breakthrough capacity increased with increasing copper content. • We observed selective oxidation of H 2 S yielding elemental sulfur. Hydrogen sulfide (H 2 S) removal by adsorption from gas streams is crucial to prevent the environmental and industrial damage it causes. Amongst the nanostructures considered excellent candidates as sorbents, porous carbon has been studied extensively over the last years. In the present work we present a synthetic procedure for three high potential sorbents based on carbon cuboids, namely a low-surface-area copper-rich structure, a highly porous aggregate without metal addition, and lastly the same porous carbon decorated with copper. The properties and performance as catalysts of these three sorbents were evaluated by powder X-ray diffraction, X-ray photoelectron spectroscopy, thermal analysis, scanning electron microscopy with energy dispersive X-ray analysis, surface area determination through N 2 adsorption and desorption, as well as by H 2 S adsorption measurements.

An atomistic simulation study of rapid solidification kinetics and crystal defects in dilute Al–Cu alloys

Rapid solidification kinetics of dilute Al–Cu alloys is simulated using a quantum mechanics based bond-order potential (BOP), in free solidification conditions, to determine kinetic and thermodynamic properties of solidification, as well as point defects and chemical ordering of the solidified structures. We measure the anisotropic kinetic coefficient, anisotropic solid–liquid interface energy, as well as solute trapping kinetics in terms of partition coefficient versus velocity and solute drag coefficient. Furthermore, solid–liquid interface free energy and its anisotropy are measured in equilibrium simulations, showing reasonably good agreement with previous studies. We also verified the self-consistency of the MD simulations, by comparing the interfacial temperature vs. velocity to that predicted by the continuous growth model. These solid–liquid interface properties are important for quantitative parametrization of larger scale solidification modeling techniques such as phase field models. We also investigated the point defect content, local chemical ordering, and local crystalline structures in the rapidly solidified samples. We found clustering of solute with vacancies, whereas copper atoms repelled each other in these dilute alloy simulations. In addition to vacancies, a large number of interstitials were found. In solidification velocities approaching the complete solute trapping regime, we found that the vacancies and interstitials formed in conjunction, i.e. as Frenkel pairs. Finally, in addition to FCC, we detected BCC and HCP phases, where the latter two were accompanied by an increase in local copper content. Understanding the formation of point defects and their relationship to chemical ordering is an important step towards controlling the formation of pre-precipitates and precipitates, which are an important strengthening mechanism for aluminum–copper alloys.

The impact of chronic exposure to MLX i3Dome on people under stress: effects on body detoxification, immune function, and mood state

ABSTRACT Using a parallel randomised control trial to demonstrate the effectiveness of 10 sessions of a Triple Combined Intervention (TCI, far-infrared, negative air ions and light therapy) in reducing stress-related symptoms in workers and detoxify the body. Twenty-one participants were randomly assigned to the experimental group (Gexp, N = 11) or the control group (Gcon, N = 10). The Gexp completed 10 × 20 min sessions using the MLX i3Dome over a 4-week period. Subjective questionnaires were assessed for sleep and psychological disturbances. Trace elements, toxic metals, cortisol, white blood count, muscular and joint soreness level (SL), body weight, resting blood pressure and well-being were also measured. Systolic blood pressure was lower after the 4-week period for Gexp participants only. Sleep improved for Gexp participants and insomnia index decrease significantly. The increase in zinc and copper concentrations were associated with a decrease in the level of lead, mercury and cortisol in the blood following the 10-session programme. An increase in lymphocyte count was reported in the Gexp only. Initial evidence suggests that a triple combined intervention (i.e. MLX i3Dome) reduces excessive stress, improves perceived sleep quality, increases general well-being, enhances body detoxification.

Effects of Sodium Monensin on Copper Metabolism of Brazilian Santa Inês Sheep Submitted to Different Dietary Copper.

This study aimed to evaluate the influence of sodium monensin on the hepatic accumulation of copper in sheep. Twenty-four Santa Inês crossbred sheep were used and allocated in a 2 × 2 factorial experiment with six repetitions and considering the factors dietary copper (basal and high) and supplementation (with and without sodium monensin). Thus, four homogeneous groups were formed: control (basal diet); monensin (Mon), 30ppm of monensin; copper (Cu), 10 10mg/kg BW per day of copper; monensin + copper (MonCu). The experimental period lasted 14weeks. Liver and bile samples were collected at the beginning and end of the experiment to determine mineral element concentrations, and weekly blood samples for biochemical, hematological, and mineral evaluation. Liver copper concentrations at the beginning of the experiment did not vary between groups, while mean liver copper concentrations at the end of the experiment were higher in the MonCu, Cu, and Mon groups when compared to the control. At the end of the study, hepatic copper concentration was influenced by copper (p = 0.0001) and monensin (p = 0.0003) supplementation. Copper-supplemented groups had reduced liver iron contents (p = 0.0287) and increased copper concentrations in bile. The biochemical evaluation showed increased serum GGT and AST activity (p < 0.05) in the Cu and MonCu groups from the eleventh week on compared to the control and Mon groups. The increase in activity of these enzymes was influenced by copper supplementation (p = 0.0340). Monensin interferes positively with the hepatic accumulation of copper and the supplementation of this additive may predispose sheep to copper poisoning.

Rocket (Eruca vesicaria (L.) Cav.) vs. Copper: The Dose Makes the Poison?

The effects of copper addition, from various adsorbents, on the accumulation ability and glucosinolate content of cultivated rocket were studied. Different adsorbents (zeolite NaX, egg shells, substrate, fly ash) were treated with copper(II) solution with an adsorption efficiency of 98.36, 96.67, 51.82 and 39.13%, respectively. The lowest copper content and the highest total glucosinolate content (44.37 μg/g DW and 4269.31 µg/g DW, respectively) were detected in the rocket grown in the substrate with the addition of a substrate spiked with copper(II) ions. Rocket grown in the fly ash-substrate mixture showed an increase in copper content (84.98 μg/g DW) and the lowest total glucosinolate content (2545.71 µg/g DW). On the other hand, when using the egg shells-substrate mixture, the rocket copper content increased (113.34 μg/g DW) along with the total GSLs content (3780.03 µg/g DW), indicating the influence of an adsorbent type in addition to the copper uptake. The highest copper content of 498.56 μg/g DW was detected in the rocket watered with copper(II) solution with a notable decrease in the glucosinolate content, i.e., 2699.29 µg/g DW. According to these results rocket can be considered as a copper accumulator plant.

Is There A Prognostic Significance For Copper, Beryllium, Boron, Titanium And Vanadium Ions In Prostate Cancer?

Aim: There are several epidemiological, clinical and experimental studies that relate heavy metal exposure to Prostatic adenocarcinoma (PCa). In this study, the relationship between benign prostatic hyperplasia (BPH) and PCa, some metal/nonmetal concentrations at the level of the histopathological diagnosis was investigated. Materials and Methods: Seventy-one patients were included in this study. The samples taken from the paraffin blocks of the patients were subjected to microwave digestion, and the samples were analyzed via Inductively coupled plasma mass spectrometry (ICP-MS) to determine the level of tissue concentrations of platinum, thallium, lead, molybdenum, cadmium, selenium77, selenium82, iron, potassium, lithium, beryllium, boron, sodium, magnesium, phosphorus, calcium, titanium, vanadium, chromium, manganese, cobalt, nickel, copper, zinc, arsenic, strontium, tin, and antimony. The findings were analyzed with SPSS. Results: When metal/nonmetal levels in prostate tissue were examined in BPH and malignant patient groups, a statistically significant difference was found in the levels of lithium (p=0.006), beryllium (p=0.02), boron (p=0.001), sodium (p=0.009), magnesium (p=0.001), phosphorus (p=0.001), calcium (p=0.001), titanium (p=0.004), vanadium (p=0.001), chromium (p=0.04), manganese (p=0.02), cobalt (p=0.003), nickel (p=0.005), copper (p=0.019), zinc (p=0.001), arsenic (p=0.002),strontium (p=0.001), tin (p=0.002) and antimony (p=0.001). Beryllium, boron, titanium and vanadium concentrations were at least five times higher in BPH tissues. When tissue metal/nonmetal levels were compared according to the new Gleason prognostic grade grouping, a significant positive correlation was found between tissue copper levels and grade (p = 0.02). Conclusion: This study showed that beryllium, boron, titanium, and vanadium are five times or more in benign prostatic hyperplasia. It also showed that the histological grade increased with increasing copper concentration. Metal concentrations should be considered for prognosis in PCa.

Structural and Electrochemical Properties of NiFe2-xCuxO4 Spinel for Oxygen Evolution Reaction

Developing new material oxides catalysts for the oxygen evolution reaction in alkaline media is important to enhance the efficiency of the water-splitting process. For this purpose, the effect of copper doping on the structural, morphological, and catalytic properties of NiFe2CuO4 oxides for the oxygen evolution reaction has been investigated. X-ray diffraction analysis of samples calcined at 1000 °C shows that the pure spinel structure was obtained in the range 0 ≤ x ≤ 0.4. The FTIR spectra confirm the presence of the metal-oxygen bond of M-O in the tetrahedral and octahedral sites of the spinel structure. Scanning electron microscopy (SEM) shows that the calcined powders have a compact and dense surface and pronounced agglomeration. The OER results indicate that the NiFe2O4 electrode exhibits a higher performance with the current density of 26 mA.cm−2 at 0.55 V and a small Tafel plot of 68 mV.dec−1. Further investigations also accounted for the degradation of electrocatalytic activity with increasing copper content.

Chemical Dissolution of Chalcopyrite Concentrate in Choline Chloride Ethylene Glycol Deep Eutectic Solvent

Currently, the high demand for copper is in direct contrast with the decrease in the mineral grade and, more significantly, the concerns regarding the environmental impact that arise as a result of processing such low-grade materials. Consequently, new mineral processing concepts are needed. This work explores the chemical dissolution of chalcopyrite concentrate at ambient pressure and moderate temperatures in a deep eutectic solvent. Copper and iron are dissolved without changing their oxidation state, without solvent pH change, and stabilized as a chloride complex with no evidence of passivation. Chemical equilibria of the metallic chloride complexes limit the dissolution, and the step that is rate-controlling of the kinetics is the interdiffusion of species in the solvent. The chemical mechanism may involve initial chloride adsorption at positive sites of the solid surface, pointing out the importance of surfaces states on chalcopyrite particles. A model based on a shrinking particle coupled with pseudo-second-order increase in the liquid concentration of copper describes the dissolution kinetics and demonstrates the importance of the liquid to solid ratio. Iron and copper can be recovered separately from the solvent, which highlights that this concept is an interesting alternative to both redox-hydrometallurgy and pyrometallurgy to obtain copper by the processing of chalcopyrite concentrate.

Investigating Phragmites australis response to copper exposure using physiologic, Fourier Transform Infrared and metabolomic approaches.

Phragmites australis (Cav.) Trin. ex Steud is a landscape plant with resistance to heavy metals that has significance in phytoremediation. However, little is known about the metabolomic background of the heavy metal resistance mechanisms of Phragmites . We studied copper stress on Phragmites and monitored physiological indicators such as malondialdehyde (MDA) and electrolyte leakage (EL). In addition, Fourier Transform Infrared (FTIR) was used to study the related chemical composition in the roots, stems, and leaves under copper stress. Furthermore, LC-MS technology was used to analyse the plants metabolic profile. Results showed that increased copper concentration in Phragmites led to the accumulation of MDA and EL. FTIR spectrum detected the presence of O-H and C=O stretching. O-H stretching was related to the presence of flavonoids, while C=O stretching reflected the presence of protein amide I. The latter was related to the change of amino acid composition. Both flavonoids and amino acids are regarded as contributors to the antioxidant of Phragmites under copper stress. Metabolomics analysis revealed that arginine and ayarin were accumulated and Phragmites leaves responded to copper stress with changes in the pool size of arginine and ayarin. It is speculated that they could improve resistance. Arginine is accumulated through two pathways: the citrulline decomposition and conversion pathway; and the circular pathway composed of ornithine, citrulline, l -argininosuccinate and arginine. Ayarin is synthesised through the quercetin methylation pathway. This study elucidates the antioxidant mechanisms for enhancing its resistance to heavy metal stress, thus improving of phytoremediation efficiency.

ОЦЕНКА ЗАГРЯЗНЕНИЯ ТЯЖЕЛЫМИ МЕТАЛЛАМИ ПОЧВ ГОРОДА ПЕТРОПАВЛОВСКА-КАМЧАТСКОГО, КАМЧАТСКИЙ КРАЙ

The results of determining the gross content of zinc, copper and lead in the surface soil layer, collected in Petropavlovsk-Kamchatsky, are presented in the paper. Based on them the heavy metal pollution degree assessment in different places of the city during 2017–2020 is given. It was found that almost everywhere the lead content in soils corresponded to a very high or high degree of contamination. According to the concentration of copper and zinc, the soils were classified as low and medium polluted. During 2017–2020 an increase of copper and zinc concentration in soils was registered. The dynamics of changes in lead concentration, on the contrary, was poorly expressed during 2017–2018. In 2020 a decrease in its content was found in all observed areas. According to the integrated pollution indexes PLI and NPI, the most polluted soils were identified in such areas as ‟Hospital” (2017),‟Botanicheskiy Pereulok” (2018), ‟Stadium Spartak” (2020). All city soils were characterized by a weak degree of potential environmental risk resulting from heavy metal pollution. The obtained data can be used to monitor heavy metal contamination of urbanized territories soils in Kamchatka Territory.

Thermal conductivity characterization of Ni60A/WC composites with different copper dilutions

To improve the accuracy of heat transfer analysis of coating, the influence of the dilution ratio on the thermal-physical parameters of coating was considered for the first time. Ni60A/WC composites with different copper content were prepared by smelting to simulate the Ni60A/WC coatings with different dilution ratios. The thermal conductivity of composites at different temperatures was systematically characterized. As the increase of copper content and temperature, the thermal conductivity shows an upward trend. The composites with 30% copper content at 600 °C shows a higher thermal conductivity of 26.8 W/(m·K). A fourth-order polynomial function between thermal conductivity and copper content was created for the first time by non-linear fitting. As a result, the value of thermal conductivity of the Ni60A/WC composite coating with different copper dilutions can be approximately predicted.

Вміст мінеральних елементів у тканині печінки щурів за набутої інсулінорезистентності та ожиріння на тлі йододефіциту

The purpose of the study was to determine the content of mineral elements in the hepatocytes of rats with insulin resistance, obesity, iodine deficiency, insulin resistance in combination with iodine deficiency and obesity in combination with iodine deficiency. Materials and methods. The study was performed on 90 white nonlinear rats weighing 120-180 g, which were divided into five experimental groups: rats with insulin resistance (1st experimental group, n = 15), animals with iodine deficiency (2nd experimental group), animals with insulin resistance in combination with iodine deficiency (3rd experimental group, n = 15), obese animals (4th experimental group, n = 15), obese animals in combined with iodine deficiency (5th experimental group, n = 15). The control group consisted of 15 intact rats. The content of Fe, Ca, Cu, Mg, Zn, Mn, Cr in the liver homogenate was determined by atomic absorption spectrometry on a SPECORD M 40 spectrophotometer (Germany). Results and discussion. In animals with insulin resistance, there was a decrease in the content of copper in the liver by 26.9%, in animals with iodine deficiency the content of this trace element increased by 20.5%, and in the group of animals with insulin resistance in combination with iodine deficiency it increased by 10.1%. The iron content in the group of animals with insulin resistance is higher in relation to the control by 33.7%, in the group of animals with iodine deficiency – by 38.5%, in animals with insulin resistance in combination with iodine deficiency – by 40.8%. Regarding the content of Calcium, in the liver homogenate of animals with insulin resistance it is higher compared to the control by 24%, in animals of the second experimental group –by 26.4%, in animals of the 3rd experimental group – by 22%. The Magnesium content in animals with insulin resitance is lower compared to the control by 19%, in animals with iodine deficiency – by 25.5%, in animals with insulin resistance in combination with iodine deficiency – by 29%. As for Zinc, no significant fluctuations in the content of this trace element were detected. In animals of the 1st, 2nd and 3rd experimental groups it is lower compared to the control by 10%, 15% and 11.1%, respectively. The Manganese content in animals with insulin resistance is lower compared to the control by 13.6%, in animals with iodine deficiency – by 18.2%, in animals with insulin resistance in combination with iodine deficiency – by 14.8%. With regard to chromium, we found a probable decrease in the concentration of this trace element in animals of the group with insulin resistance by 48%, in animals of the 2nd experimental group – by 57.5%, in animals of the 3rd experimental group – by 58%. In the group of animals with obesity and obesity in combined with iodine deficiency we found an increase in copper content compared to the control by 27.4% and 36.2%, respectively. The iron content in animals with obesity exceeds the control by 34.8%, in the group of animals with obesity in combined with iodine deficiency – by 38.4%. Regarding the content of Calcium, in animals with obesity it is higher by 25.7%, and in animals with obesity in combined with iodine deficiency – by 28.4% compared to the control. Magnesium content in animals with obesity is lower by 27.3% compared to the control group, and in animals with obesity in combined with iodine deficiency – by 28.4%. Regarding Zinc, no significant fluctuations in the content of this trace element were detected. In animals of the 4th and 5th experimental groups it is lower compared to the control by 18.4% and 23.5%, respectively. The content of Manganese in the group of animals with obesity decreased by 14.8%, and in the group with obesity in combined with iodine deficiency the content of this trace element decreased by 16.2% compared to the control. With regard to chromium, we found a probable decrease in the concentration of this trace element in animals of the group with obesity by 58.1% and in the group of animals with obesity in combined with iodine deficiency by 56.2%. Conclusion. The obtained results demonstrate changes in the content of mineral elements in groups of animals with insulin resistance, iodine deficiency, insulin resistance in combination with iodine deficiency, obesity and obesity in combination with iodine deficiency

Probing the Role of Cu(II) Ions on Protein Aggregation Using Two Model Proteins.

Copper is an essential trace element for human biology where its metal dyshomeostasis accounts for an increased level of serum copper, which accelerates protein aggregation. Protein aggregation is a notable feature for many neurodegenerative disorders. Herein, we report an experimental study using two model proteins, bovine serum albumin (BSA) and human serum albumin (HSA), to elucidate the mechanistic pathway by which serum albumins get converted from a fully folded globular protein to a fibril and an amorphous aggregate upon interaction with copper. Steady-state fluorescence, time-resolved fluorescence studies, and Raman spectroscopy were used to monitor the unfolding of serum albumin with increasing copper concentrations. Steady-state fluorescence studies have revealed that the fluorescence quenching of BSA/HSA by Cu(II) has occurred through a static quenching mechanism, and we have evaluated both the quenching constants individually. The binding constants of BSA–Cu(II) and HSA–Cu(II) were found to be 2.42 × 104 and 0.05 × 104 M–1, respectively. Further nanoscale morphological changes of BSA mediated by oligomers to fibril and HSA to amorphous aggregate formation were studied using atomic force microscopy. This aggregation process correlates with the Stern–Volmer plots in the absence of discernible lag phase. Raman spectroscopy results obtained are in good agreement with the increase in antiparallel β-sheet structures formed during the aggregation of BSA in the presence of Cu(II) ions. However, an increase in α-helical fractions is observed for the amorphous aggregate formed from HSA.

Synthesis and characterisation of Cu - Doped TiO2 nanoparticles for DSSC and photocatalytic applications

In the present work, copper-doped TiO2 nanoparticles were synthesized via sol-gel technique with different molar concentration of copper precursor (0.025 M-CT-1, 0.05 M-CT-2, 0.1 M-CT-3 and 0.2 M-CT-4). The effect of copper doping on the structural, morphological, compositional, optical and electrical properties of TiO2 was systematically analyzed for its better suitability as photoanode in Dye-Sensitized Solar Cells (DSSC) and photocatalyst in dye degradation. From structural analysis, all the synthesized samples show anatase phase with a tetragonal crystal system. The broadening and shift in the peaks of the synthesized samples show the successful incorporation of Cu ions into TiO2 lattices. All the synthesized samples exhibit spherical shape morphology with slight agglomeration. EDS analysis exhibit the purity of the synthesized nanoparticles with the presence of only Ti, O, and Cu. UV-DRS analysis reveals the decrease in reflectance of the TiO2 with increasing the Cu concentration. The bandgap values of the Cu–TiO2 decreased from 2.66 to 2.40 eV with the increase of copper concentration. From PL analysis, the peak observed at 380.20, 469.56 and 535.24 nm corresponds to the band-band PL emission, free excitons, and oxygen vacancies, respectively. Further, we have fabricated DSSC using Cu-doped TiO2 as a photoanode without treatment of any scattering layer and we have obtained the maximum efficiency of 3.90% for 0.1 M Cu–TiO2 (CT-3). Similarly, the maximum degradation efficiency of 97.12% was obtained against rhodamine-B dye with the highest regression coefficient (R2 = 0.9957) and lesser half-life degradation time (t1/2 = 47.1428 min) for CT-3. This higher efficiency was not reported elsewhere using Cu-dopant concentrations. From these observations, it was concluded that 0.1 M concentration of Cu was the optimum dopant concentration with TiO2 which was suitable for DSSC and photocatalytic applications.

Copper stimulation on methane-supported perchlorate reduction in a membrane biofilm reactor

The present study demonstrated that the perchlorate reduction rate in a methane-based membrane biofilm reactor was significantly enhanced from 14.4 to 25.6 mg-Cl/L/d by increasing copper concentration in the feeding medium from 1 to 10 μM, indicating a stimulatory effect of copper on the methane-supported perchlorate reduction process. Batch tests further confirmed that the increased copper concentration enhanced both methane oxidation and perchlorate reduction rates, which was supported by an increasing trend of functional genes (pmoA for methanotrophs and pcrA for specific perchlorate reducers) abundances through quantitative polymerase chain reaction (qPCR). Both 16S rRNA gene sequencing and functional genes (pmoA and pcrA) sequencing jointly revealed that the biofilm supplied with a higher copper concentration exhibited a more diverse microbial community. The methane-supported perchlorate reduction was accomplished through a synergistic association of methanotrophs (Methylocystis, Methylomonas, and Methylocystaceae) and perchlorate reducers (Dechloromonas, Azospira, Magnetospirillum, and Denitratisoma). Acetate may function as the key syntrophic linkage between methanotrophs and perchlorate reducers. It was proposed that the increased copper concentration improved the activity of particulate methane monooxygenase (pMMO) for methane oxidation or promoted the biosynthesis of intracellular carbon storage compounds polyhydroxybutyrate (PHB) in methanotrophs for generating more acetate available for perchlorate reduction.

The Copper Influence into Physical and Mechanical Properties of the Al-5Si Alloy

The microstructure and the hardness due to addition of copper of the Al-Si-Zn-Mg-Cu Alloy have been investigated. The copper has been varied from 0 wt.%– 4.9 wt.% in order to see how the microstructure and the hardness of the alloy change. The Heat treatment at temperature 510 o C during 5 hours and then cooling to ambient temperature, have done to foster the dissolution of copper in the crystal and then precipitate during cooling. The results show that the alloying element form a phase distributed in the matrix of the alloy. Increasing the content of the copper makes the form of the second phase smaller and at the matrix show fine particle distributed mostly entire of the surface. The hardness of the alloy increase as the copper content increase. The increase in hardness might come from the fine particle distributed in the matrix. The onset, endset and melting temperature tend to decrease as the copper content increase.