Search

Objectives : Effects of various Cu2+ concentrations in the synthetic wastewater on nitrite accumulation was investigated in a submerged partial biofilter reactor (SPBNR).Methods : Experiments were carried out at the constant operational conditions (T=35℃; pH=9.0 and DO=2.0 mg O2/L) by varying the concentrations between 5-50 mg Cu2+/L. The SPBNR, which was operated in an upward flow mode, set-up consisted of a cylindrical stainless steel. The support materials filling ratio was about 23% of the total reactor volume. The SPBNR was inoculated with microorganism drawn from a batch experimental biological reactor operated about one month by using the synthetic wastewater composition.Results and Discussion : Before exposure to Cu2+, the highest loading rate of 1.3 g NH4-N/(m2.day) was determined under the operational conditions. Addition of 5 µg Cu2+/L into the waters promoted the activity of organisms and the loading rate achieved to 1.6 g NH4-N/(m2.day). At the control operational condition, the ratio of NO2-N/NOx-N was determined as 0.74, while the ratio increased to 0.78 at the Cu2+ concentration of 5 µg/L.Conclusions : Results indicated that the ammonium oxidizing bacteria (AOB) is more stimulated than the nitrite oxidizing bacteria (NOB) at the concentration of 5 µg Cu2+/L. However, approximately equal NH4-N removal rate (ANRR) and NO2-N accumulation rate (NiAR) losses indicated that the AOB and NOB are approximately equally effected at the inlet concentrations of 35 and 50 µg Cu2+/L.

A high auriferous arsenopyrite floatability is desirable to maximise gold recovery in sulphidic refractory gold ore flotation. This study examines the adsorption properties of sulphidic refractory gold ore (2.58 g/t Au) in the presence of sodium isobutyl xanthate (SIBX) collector, under different pH and CuSO4 additions for maximum arsenopyrite and gold floatability. The SIBX adsorption studies showed that pH greatly influences SIBX adsorption on to the surface of sulphidic refractory gold ore. Very little effect of CuSO4 on SIBX adsorption in acidic environment (pH 5–5.5) was observed due to low copper ions adsorption. Better flotation recoveries of arsenopyrite (86%) and gold (91%) were achieved at the ore's natural pH (8–8.5) than under acidic or basic environments. Pyrite floated poorly (

Copper has been used by nursery managers for more than 100 years to suppress fungi and as a fertilizer for more than 50 years. Consequently, nursery seedlings with copper deficiencies are rare, especially for broadleaf species. In many nurseries, soil contains

An investigation into the effects of proton beam exposure on high- and low-copper structural materials for nuclear reactors has been carried out. The aim of this work was to investigate the impact of proton energy irradiation on the damage of the materials. The damage parameter used in the evaluation was displacement per atom (dpa) in material as a function of proton energy. In addition, a TRIM code was used to identify the penetration depth in response to changes in proton energy. The effect of proton beam exposure on the irradiation induced hardening of the different copper levels was investigated by Vickers Hardness tests for microstructural changes examination. The proton beam incident energy was 3 MeV and the temperature was kept at approximately 30 ᴼC. A 25 μm flat damage profile was achieved at 0.367 and 0.373 dpa for low and high copper samples , respectively. The hardness variation with depth and yield strength variation with dose (dpa) were also investigated. Based on the results, the study found that the hardness test for the high copper was higher than the low copper. User 14.00 Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman","serif"; mso-ansi-language:EN-US; mso-fareast-language:EN-US;}

The aim of this study was to investigate the effect of incorporating low copper (0, 0.5, 1, 1.5, and 2 wt.%) additions into as-forged AISI 304 stainless steel (304SS). The microstructures and mechanical properties of the steel were examined using scanning electron microscopy and a universal testing machine. The antibacterial properties of the Cu-bearing 304SS specimens were investigated using Escherichia coli. Each specimen was soaked in artificial saliva to detect the release of copper ions through inductively coupled plasma atomic emission spectrometry. The addition of copper had no significant effect on the microstructure of the as-forged Cu-bearing 304SS, but it slightly increased its maximum tensile strength. The antibacterial rate of the as-cast and as-forged 304SS with 2 wt.% Cu was over 80%, which corresponded to an increase in the release of copper ions. This study demonstrates that low-Cu-content stainless steel can reduce bacteria and can be a suitable material for the oral environment because of the low release of Cu ions.

The onset and progression of many degenerative diseases including atherosclerosis, have been shown to directly link to the presence/absence of certain metal ions. Consequently, the detection of these ions in tissues may improve the understanding of the driving pathophysiology. The Cu content during atherosclerosis development has not been studied due to its low concentration involved. In this work, the Cu level in atherosclerotic rabbit tissue is determined using PIXE with a 3.5 MeV proton beam. The arteries of three animal groups fed with different diets were studied: group 1, rabbits on normal standard diet, group 2, on High Fat Diet (HFD) and group 3, on HFD + Zinc diet. Zinc supplement has been proven to inhibit the beginning of atherosclerotic lesion. The result of this study shows that the Cu levels in all the atherosclerotic lesions were lower than that in the arterial walls of the samples in HFD group, This work has been partially funded by a UAM-Banco de Santander Interuniversity Cooperation with Asia Grant (2017–2018) and by the Ministerio de Ciencia, Innovacióny Universidades (CTQ2017-84309-C2-2-R)

In recent years, the “Copper-2 Hypothesis” has been put forth in an attempt to explain the epidemic of Alzheimer’s disease (AD) in the Western world. According to this hypothesis, “free” copper (copper-2) in drinking water, dietary supplements, and meat is the chief cause of the increased incidence of AD in recent decades. In contrast to the US, copper plumbing for drinking water is not used in Switzerland and tap water is very low in copper. Other “risk” factors including dietary supplements and meat consumption are also lower in Switzerland than in the US. Yet, the incidence of AD is closely similar in the two countries. This contradicts the Copper-2 Hypothesis. Impact statement The Western world is faced with an Alzheimer’s epidemic. Identifying the life style and anthropogenic factors involved has become a priority. This is a formidable challenge due to the complexity and the slow progression of the disease. A hypothesis put forth by George Brewer postulates divalent copper (copper-2), chiefly present in drinking water from copper pipes, to be a major risk factor for Alzheimer’s disease. In Switzerland, copper pipes are not used for drinking water, but the frequency of Alzheimer’s disease is similar to that of other Western countries. This contradicts Brewer’s hypothesis and suggests that other factors are responsible for today’s Alzheimer’s epidemic.

Highly hydrophilic hydrogels are able to potentially act as fouling-resistant coatings to prevent the settlement of marine organisms, due to the inherent surface properties. It is highly desired to improve mechanical and antifouling (AF) performance of hydrogels for durable and effective usage. Herein, a kind of composite hydrogels with enhanced mechanical properties and synergetic AF activity is prepared in a simple and low-cost way. The cooperation of biocidal copper release and non-fouling interfaces is realized, resulting in improved AF performance. Spherical cuprous oxide-tannic acid submicroparticles can be incorporated into poly(vinyl alcohol) (PVA) hydrogels by a freeze-thaw process. The hydrogels exhibit underwater superoleophobicity, improved strengths and moduli, and self-healing ability. Incorporation with the fouling-resistant effect, low-level, sustainable copper release rates endow the hydrogels with improved AF activities against the green alga Chlorella Vulgaris. The low copper release rates also mean the minimized environmental influence. It holds great promise for applying such robust, multifunctional composite hydrogels in long-term AF applications on both dynamic and static conditions.

As part of an extensive research program to study recent, unexpected intergranular corrosion (IGC) on 6xxx series aluminum alloys (AlMgSi), this paper investigates the mechanism of initiation and early propagation of IGC on the extruded AA6005-T5 alloy with small Cu content (0.1 wt%) by use of advanced electron microscopy techniques applied for near surface characterization. Corrosion testing was restricted to the accelerated IGC test according to the standard BS ISO 11846, involving exposure to acidified chloride solution. The effect of modifying the as-received extruded surface by metallographic polishing, argon sputtering, and alkaline etching was investigated. Initiation of IGC was delayed on the as-received surface compared to the modified surface, caused by the presence of an approximately 8 nm thick crystalline oxide layer formed during extrusion. IGC initiated at the primary α-Al(Fe,Cu,Mn)Si particles for all types of surfaces. However, these particles corroded rapidly in the test solution forming a residue of Cu and Si on the exposed particle surface. This phenomenon, as well as enrichment of Cu on the Al matrix surface by dealloying, contributed increasingly to the formation of new effective cathodic sites and continuing propagation of IGC. The AlMgSiCu (Q) phase, present as primary and secondary particles, was relatively inert against both oxidation and reduction. © The Author(s) 2019. Published by ECS. This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 License (CC BY, http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse of the work in any medium, provided the original work is properly cited. [DOI: 10.1149/2.0211911jes]

Copper is one of the most ubiquitous environmental pollutants worldwide. Previous studies have focused on the toxicology of high copper exposure, while there has been comparatively less research on the biological effects of low copper exposure. Low concentrations of copper often exist in freshwater ecosystems, and its impact on the fish is unclear. Both Xenocypris microlepis and Xenocypris davidi are bottom-feeding fishes widely distributed in freshwater ecosystems of China, and they are more likely to be contaminated by low concentrations of copper. Low copper exposure may have effects on molecular regulation at the level of gene expression in the two Xenocypris species. To investigate gene expression differences involved in the response to low copper concentrations between X. microlepis and X. davidi, we established the responses to low copper exposure of 0.01 mg/L for 14 days at the transcriptional level, and RNA-Seq was used to perform a comparative transcriptomic analysis of the liver. A total of 74,135 and 60,894 unigenes from X. microlepis and X. davidi were assembled by transcriptome profiling, respectively. Among these, 84 genes of X. microlepis and 165 genes of X. davidi were identified as differentially expressed genes (DEGs). There were 60 and 135 up-regulated, 24 and 30 down-regulated genes in the two species, respectively. Comparative transcriptome analyses identified five differentially co-expressed genes (DCGs) related to low copper exposure from the DEGs of the two Xenocypris species. The five DCGs were related to the fishes' growth, antioxidant system, immune system and heavy metal tolerance. The results could help us to understand the molecular mechanisms of the response to low copper exposure, and the data should provide a valuable transcriptomic resource for the genus Xenocypris.

In this study, we developed and investigated a new non-oriented electrical steel (50H-CP) to be used in mainly induction motors. This material exhibits high flux density and low iron loss. We confirmed the effect of the new material by manufacturing a test motor and comparing its performance against another motor with a standard material (50H350). The efficiency of the motor with 50H-CP showed an improvement of 1% compared to the one with 50H350 because of the low copper losses in the former. Furthermore, the breakdown of the motor losses was evaluated using electromagnetic field analysis. The iron loss was comparable between 50H-CP and 50H350. However, 50H-CP was superior with regard to primary and secondary copper losses. From the above results, the effect of the high magnetic flux density-low iron loss characteristics of 50H-CP was theoretically confirmed.

Cu-modified zeolites have enormous potential as the catalysts facilitating the conversion of methane to methanol. It becomes important to investigate the active sites and the reaction mechanisms involved. In this paper, several spectroscopic methods such as UV-vis diffuse reflectance spectroscopy (UV-vis DRS), pulse electron paramagnetic resonance (EPR), diffuse reflectance Fourier transform infrared spectroscopy, and solid-state (

International audience; We report the use of air-stable Cu(I)-NHC complex 4a as a catalyst for the efficient microwave-assisted synthesis of peptidotriazoles on solid phase. Compared with the usual conditions (CuI or CuSO4/NaAsc), catalyst 4a allowed the preparation of a series of peptidomimetic compounds containing a 1,2,3-triazole ring in their backbone without the oxidation of common side-chains. Overall, the peptidotriazoles were obtained in good yields (61–87%), in excellent purity (higher than 94%) and with low copper contamination

The metal mining activity has been the source of large volumes of tailings that must be stored in tailings storage facilities (TSFs). Since tailings might contain residual valuable metals, these are often subject of assessment studies aimed to find a feasible way to reprocessing. One of these TSFs was built and operated during the 1930’s for the exploitation of a giant porphyry copper deposit in Chile, a deposit that is still under exploitation today. For these old tailings a historical assessment was varied out about the copper recovery potential in a reprocessing scenario by flotation. Based on theoretical concepts and available historical operational data, it can be shown that the main reason for the relatively high copper grades found in these tailings are the corresponding high grades of the processed ores, instead of being the result of an inefficient past technology of flotation with consequential low recoveries. Conversely, the former flotation circuit was optimal concerning the recovery of copper sulphides favoured by the less restrictive high copper content of these sulphides. Consistently, it is argued for the study case that the main advances in flotation circuits have focused on improving selectivity without sacrificing recovery, due to the changes in the mineralogy of the exploited ores. These are relevant facts for a reprocessing scenario, indicating a low copper recovery potential if the current conventional flotation technology is considered; thus other and/or newer processing technologies could be more efficient for recovery of the remaining copper. There are hydrometallurgical potential alternatives for reprocessing but limitations are expected in relation to milling size of the tailings material. The present findings may apply elsewhere, due to the high representativeness of the present study case.

Accurate and reliable determination of copper in vegetables and water is often difficult because of low copper concentrations and matrix effects. A new dispersive liquid–liquid microextract...

A low-temperature layered phase CuxTiS2 (0 ≤ x ≤ 0.7) has been prepared. The occupation of both octahedral and tetrahedral sites by the copper atoms in the interlayer gap of the TiS2 lattice is revealed. The presence of two concentration regions of 0 ≤ x ≤ 0.3 and 0.5 ≤ x ≤ 0.7, which differ in the concentration dependence of the unit cell volume, has been observed. In the first region the unit cell volume increases with x, in the second region it decreases. This difference may be associated with the competition between Cu-Ti and Cu-S covalent centres. The electrical and magnetic properties of the materials are in a good agreement with this assumption. The electronic structure of CuxTiS2 in the low copper concentrations region has been studied using X-ray photoelectron, resonant photoelectron and absorption spectroscopy techniques. It was found that, in the low copper concentrations region, the charge transfer from Cu to the conduction band of TiS2 along with the formation of covalent centres is observed.

Based on the principle of multiphase equilibrium, a mathematical model of the copper flash converting process was established by the equilibrium constant method, and a computational system was developed with the use of MetCal software platform. The mathematical model was validated by comparing simulated outputs, industrial data, and published data. To obtain high-quality blister copper, a low copper content in slag, and increased impurity removal rate, the model was then applied to investigate the effects of the operational parameters [oxygen/feed ratio (ROF), flux rate (RF), and converting temperature (T)] on the product weights, compositions, and the distribution behaviors of impurity elements. The optimized results showed that ROF, RF, and T should be controlled at approximately 156 Nm3/t, within 3.0 pct, and at approximately 1523 K (1250 °C), respectively.

During treatment of copper-cobalt ores with a high nickel content of one of the domestic deposits by standard technology, it is expected to obtain converter matte containing, wt.%: 60–68 Ni, 7–9 Cu, 4–6 Fe, 2–3 Co, 21–23 S. It has been established for a model sample (wt. %: 62 Ni, 7.1 Cu, 3.7 Fe, 2.2 Co, 18 S) that processing converter matte under conditions of increased oxygen pressure is much more effective than under atmospheric conditions, and this is indicated by a reduction in the duration of pressure leaching (1.3–1.5 h) compared with leaching under atmospheric conditions (4–8 h), and also indices for extraction of economic components into solution (wt. %: 67 Ni, 99 Cu, 99 Fe). Due to the use of special experiment planning programs, a more complete study is achieved for the effect of oxygen pressure and temperature on leaching nickel, and also determination of the most effective production parameters for performing the process. In view of the low copper content, flotation separation of this converter matte is ineffective. Separation of copper and nickel is accomplished by selective pressure leaching of nickel from converter matte. It is established that as a result of selective leaching of nickel from copper-nickel converter matte the initial acid concentration has a considerable effect. It is possible to extract nickel into solution at the level of 50–55% and copper and iron are concentrated in cake (concentration in final solution is mg/dm3: 0.06 Cu and 0.62 Fe). A method is proposed for processing leaching products.

The grapevine is the most widely cultivated and economically important fruit species worldwide. Downy mildew produced by Plasmopara viticola, which occurs throughout the wide, is one of the most destructive of all grapevine diseases. In organic farming, copper is the only product effective against this pathogen accepted under European organic farming regulation EC 889/2008. Recently, due to its high environmental impact, the use of copper in organic farming has been limited by legislation to a yearly maximum of 6 kg/ha and its use will probably be even more restricted in the future. For this reason, the average dose recommended by pesticide producers of about 1 kg/ha per treatment should be revised. The aim of this work was to provide scientific support to effectively use reduced copper concentrations. A leaf disk assay was used to determine the minimum copper dosage that provided effective control. Dosages higher than 5 mg Cu/m 2 (of grapevine leaf material) did not prove to be more effective than the dosage of 5 mg Cu/m 2 itself. With a post-infection disk assay, copper treatments made 1 h after a simulated infectious rain, were also confirmed to give the same efficacy as preventive copper treatments. The efficacy of preventative low copper doses was validated in field trials. In the field, the rates of 200 and 400 g Cu/ha (equivalent to 5 and 10 mg Cu/m 2 , respectively) was able to significantly reduce downy mildew (72–89% efficacy), confirming results obtained from leaf disks assays. Adjusting from higher copper spray rates, to those between 200 and 400 g Cu/ha should provide sufficient control depending on the infection pressure. This spraying regime should also enable viticulturists to remain under the current annual limit of 6 kg/ha and likely under lower limits that might be proposed in future regulations.

International audience; "Fourteen hollow and one cast anthropomorphic and zoomorphic figurines produced in Incan times for ritual offerings from the Ethnologisches Museum in Berlin were selected to investigate the technologies and alloys used for their fabrication with portable optical microscopy and non-destructive XRF elemental analysis. This group of gold and silver figurines includes typical specimens of the Inca production, such as the four silver figurines from the Island Coati in Lake Titicaca and the two gold figurines from Pachacamac, as well as specimens that are seldom present in collections, which makes them atypical. In addition to the tall figurines with atypical hair or standing pose, one bicolour figurine (half silver, half gold) and another with coloured inlays were included in this study for comparison. The large majority of the silver specimens are made from very high quality alloys and the gold figurines are made from alloys containing low copper contents and silver ranging from 30wt% to 52wt%." (source éditeur); "Catorce estatuillas antropomorfas y zoomorfas laminadas y una vaciada, pertenecientes a la colección del Ethnologisches Museum de Berlín, producidas en el tiempo de los incas para ofrendas rituales, fueron seleccionadas para abordar las tecnologías y aleaciones empleadas en su manufactura a través de las técnicas portables de microscopía óptica y elemental no destructiva FRX. Este grupo de estatuillas, en oro y plata, abarca ejemplares típicos de la producción Inca, como las cuatro figuras en plata provenientes de la Isla Coati en el Lago Titicaca y las dos en oro provenientes de Pachacamac, así como ejemplares cuyos tipos son raros en las colecciones, lo que las convierte en atípicas. Además de las grandes figuras con pelo y postura atípicos, fueron también incluidas en este estudio la estatuilla bicolor (mitad plata y mitad oro) y la figurina con incrustaciones coloridas para comparación. La gran mayoría de las figurinas de plata fueron fabricadas con aleaciones de muy buena calidad y las figurinas en oro con aleaciones conteniendo bajas cantidades de cobre y concentraciones de plata entre 30% y 52%." (source éditeur); "Quatorze figurines anthropomorphes et zoomorphes creuses et une en fonte pleine, appartenant à la collection du Ethnologisches Museum de Berlin, produites aux temps des Incas pour des offrandes rituelles, ont été sélectionnées pour approcher les technologies et alliages employés dans leur fabrication au moyen des méthodes portables de microscopie optique et d’analyse élémentaire non-destructive FRX. Ce groupe de figurines, en or et en argent, inclut des spécimens typiques de la production Inca, dont les quatre figurines en argent provenant de l’Ile Coati sur le Lac Titicaca et les deux en or provenant de Pachacamac, ainsi que des spécimens se trouvant rarement présents dans les collections et qui s’avèrent ainsi atypiques. En plus de figurines de grande taille avec des cheveux et des positions debout atypiques, une figurine bicouleur (moitié argent, moitié or) et une autre avec des incrustations colorées ont été intégrées à cette étude pour comparaison. La grande majorité des figurines en argent est produite à partir d’alliages de très bonne qualité et les figurines en or sont produites avec un alliage contenant de faibles teneurs en cuivre et une concentration en argent variant entre 30% et 52%." (source éditeur)

This study introduces the development of the straight pole four-phase double-stator switched reluctance machine (SRM) which is considered to provide high torque density and low copper loss. The basic concept behind this design is to combine the features of the mutually coupled SRM and the double-stator SRM. In this study, the analytical method alongside the 2D finite element method (FEM) verification would be presented to reveal the developing path. Moreover, to verify the proposed SRM concept, the prototype machine has been designed and built. The performance result from 2D FEM is presented.

The Litz wire has been widely utilized as a wire with a low copper loss under high-frequency operation. However, design optimization of the Litz wire is difficult because this wire generally has a complicated structure of thin strands twisted in multiple levels, which hinders both of the analytical and numerical prediction of the copper loss. To overcome this issue, recent studies have proposed the analytical models of the copper loss in the bundle of twisted strands, which is the basic components constituting the Litz wire. This paper constructs a simple analytical copper loss model of the Litz wire based on these preceding insights. In addition to these insights, the proposed model further considers the effect of the inclination angle of the strands to the Litz wire on the proximity effect loss. The proposed model was tested in comparison with the experimentally measured AC resistance of commercially available Litz wires. As a result, the predicted AC resistance showed good agreement with the measured ac resistance, suggesting the effectiveness of the proposed model.

A 7-year-old patient established on total parenteral nutrition inclusive of 0.11 mg/kg/day (0.17µmol/kg) of copper daily was transitioned to exclusive nasojejunal (NJ) feeding following a small bowel transplant. Prior to this, his serum copper level was stable at 18.6 µmol/L (reference range 11.0–22.0 µmol/L). Five months into NJ Peptamen Junior Advance feeds inclusive of 0.13 mg/kg/day copper, he was noted to have poor growth and had developed pancytopaenia. This prompted investigations, including a full serum nutritional screen, which led to detection of a low serum copper level of 1.7 μmol/L. He had no neurological abnormalities on examination. Questions were raised regarding whether jejunal feeding was causative in this trace element deficiency. In individuals younger than 18 years (patient), are those fed exclusively into the jejunum (intervention), compared with those fed via the mouth or the stomach (comparison), more likely to develop copper deficiency (outcome)? An Ovid MEDLINE (1946–February 2019, week 5) and EMBASE (1947–2019, week 10) search was conducted on 9 March 2019 using the search terms ‘copper deficiency’ OR ‘low copper’ AND ‘jejunal feeding’ OR ‘jejunal nutrition’ OR ‘tube feeding’ OR ‘exclusive jejunal feeding’ OR ‘ feeding’ OR ‘jej$’ AND ‘paediat$’ OR ‘pediat$’. Results …

The Staffordshire Hoard is the largest ever find of Anglo-Saxon gold and silver metalwork. The collection comprises many hundreds of objects, in approximately 3900 fragments. Most objects are fittings from swords, but there are also fragments from at least one helmet, and a small but significant collection of Christian objects. An initial study of 16 gold objects from the collection suggested that some form of deliberately induced depletion gilding had taken place to remove both silver and copper from the surface of the metal (Blakelock, In press). Subsequently, both surface and quantitative core alloy SEM-EDX analysis was undertaken on a further 114 Hoard objects. Over 222 individual components (i.e. different parts of objects) were analysed during this study. This is the largest quantitative survey of Anglo-Saxon gold and, contrary to expectations, no reliable relationship was found between the fineness of alloy used and object date, although the low copper content is consistent with the use of recycled coinage as a source of gold. However, over 100 components were judged to be deliberately depleted in silver at their surface which, it is argued, was the result of a deliberate and probably widespread Anglo-Saxon workshop practice. Previously unrecognised, this involved the depletion gilding of sheet gold to create contrast between decorative components, as well as to enhance colour. Furthermore, in the light of the identification of this systematic surface enrichment, similar approaches should be considered to investigate goldsmithing practices in other cultures and time frames.

Bisindoles (BIMs) were modulated as powerful N,N′ donor ligands for the copper-catalyzed Sonogashira reaction. Ligand screening experiments on 11 BIM compounds found that 3,3′-(4-chlorophenyl)methylenebis(1-methyl-1H-indole) (10%) efficiently accelerated CuCl (5%)-catalyzed cross-coupling of aryl iodides with terminal alkynes. A wide range of substituted aryl iodides and/or alkyl- and aryl-substituted terminal alkynes were examined, leading to the corresponding coupling products with yields up to 99%. An efficient and scalable protocol for the synthesis of BIM ligands on a gram scale, with extremely low catalyst loading of o-ClC6H4NH3+Cl−, was also developed with a reaction time of 20 min with yields up to 93%. This novel N,N′ ligand was air-stable, easily available and highly modulated with low copper loading. Copyright © 2016 John Wiley & Sons, Ltd.

Nowadays, great attention is being paid to the recycling of copper-containing materials. Especially for the secondary copper-containing material treatment, rotary bevel drum-type furnaces are used. Such furnaces are mainly represented by the Kaldo furnace and the tilting rotating oxy-fuel (TROF) converter. In Russia, a number of such units are in use. The main advantage of these furnaces is a strap slag processing facility. Such slag is formed because of the high zinc and tin content in the feedstock. The ability of slag mixing allows one to obtain waste slag with a low copper content.

An air-stable supported Cu(I) catalyst, CuI@PS-Phen, was designed and synthesized. CuI@PS-Phen can efficiently catalyze the click polymerization of diynes a and diazides b to produce soluble and thermally stable polytriazoles with high molecular weights (M w up to 30800), and low copper residue content (down to 190 ppm) in high yields (up to 94.2%) under mild reaction conditions without the exclusion of oxygen.

A dramatic acceleration in copper-catalyzed Sonogashira-type reactions was observed when an organophosphate was used as additive. The catalyst systems featuring low copper loading (0.5 mol% < Cu < 5 mol%) gave Sonogashira-type products with a broad scope of aromatic and aliphatic terminal alkynes as well as aryl iodides in good to excellent yields. Among the organophosphate/copper catalytic systems, that of 4 mol% Cu(OTf)2/10 mol% (R)-(−)-1,1′-binaphthyl-2,2′-diyl hydrogenphosphate exhibited the highest catalytic activity. Copyright © 2015 John Wiley & Sons, Ltd.

Although the Cu2+-binding sites of the prion protein have been well studied when the protein is fully saturated by Cu2+, the Cu2+-loading mechanism is just beginning to come into view. Because the Cu2+-binding modes at low and intermediate Cu2+ occupancy necessarily represent the highest-affinity binding modes, these are very likely populated under physiological conditions, and it is thus essential to characterize them in order to understand better the biological function of copper–prion interactions. Besides binding-affinity data, almost no other thermodynamic parameters (e.g., ΔH and ΔS) have been measured, thus leaving undetermined the enthalpic and entropic factors that govern the free energy of Cu2+ binding to the prion protein. In this study, isothermal titration calorimetry (ITC) was used to quantify the thermodynamic parameters (K, ΔG, ΔH, and TΔS) of Cu2+ binding to a peptide, PrP(23–28, 57–98), that encompasses the majority of the residues implicated in Cu2+ binding by full-length PrP. Use of the buffer N-(2-acetomido)-aminoethanesulfonic acid (ACES), which is also a well-characterized Cu2+ chelator, allowed for the isolation of the two highest affinity binding events. Circular dichroism spectroscopy was used to characterize the different binding modes as a function of added Cu2+. The Kd values determined by ITC, 7 and 380 nM, are well in line with those reported by others. The first binding event benefits significantly from a positive entropy, whereas the second binding event is enthalpically driven. The thermodynamic values associated with Cu2+ binding by the Aβ peptide, which is implicated in Alzheimer’s disease, bear striking parallels to those found here for the prion protein., The thermodynamics (K, ΔG, ΔH, and TΔS) of the two highest affinity Cu2+-binding events of the prion protein were investigated using isothermal titration calorimetry. Peptide PrP(23−28, 57−98) was used as a model system for the metal-binding region. The first binding event had a Kd of 7 nM and was entropically driven (+ΔS), whereas the second binding event had a Kd of 380 nm and was enthalpically driven (−ΔH).

The effects of copper pollution on the polyphenol content, color, and antioxidant activity of wine, as well as correlations among these factors, were investigated. Copper had clear influences on wine polyphenol content. At low copper concentrations, the concentrations of nearly all polyphenols increased, and the antioxidant activity values of the wine also increased. When the copper concentration reached the lowest level of the medium copper range (9.6~16 mg/L), most of the indices also improved. When the copper concentrations reached the latter part of the medium copper range (19.2 and 22.4 mg/L), many of the tested indices began to decrease. Furthermore, when the copper concentration reached the high ranges (32, 64, and 96 mg/L), the polyphenol content, CIELAB color parameters, and antioxidant activity of wine were substantially decreased, indicating the need to control increasing copper content in grape must.

Embrittlement is the primary factor limiting the lifetime of reactor pressure vessels (RPVs). This literature review provides an overview of the causes of hardening and non-hardening embrittlement in RPV steels, with a specific emphasis on precipitation hardening caused by manganese–nickel rich precipitates (MNPs) in thermally aged RPV steels. Several models used to describe the hardening mechanism are discussed. The role of atom probe tomography (APT) in investigating solute clustering in RPV steels is also discussed. The characterisation of nanoscale clusters is enabled by APT’s unique combination of high mass and 3D spatial resolution. This technique, its limitations and the relevant statistical analysis methods available are reviewed.

Effect of grinding fineness and inhibitors on mixed flotation of low copper and nickel were studied and a new nickel inhibitor YS was used in the process of separation of copper and nickel. The results indicated that the high-quality mixed concentrate with the recoveries of Cu and Ni 76% and 65.6% and the grade of Cu and Ni were 4.66% and 4.3%, respectively, was got under the condition of sodium silicate (200 g/t), CMC (200 g/t), copper sulphate200 g/t, amyl xanthate 100 g/t and pine oil 30 g/t with the grinding fineness of-0.074mm80%. Then, Qualified Cu concentrate with the grade26.65% and recovery 55.62%, Qualified Ni concentrate with the grade26.65% and recovery 55.62%, respectively, were got by using the new nickel inhibitor YS in the separation flotation of copper and nickel.

Copper plays an essential role in numerous enzymatic reactions in the human body and hypocupremia manifests itself as cytopenias and/or neuropathy. Copper deficiency is also a mimic of dysplasia, and this may cause diagnostic difficulties with true myelodysplasia. In this case report, we present a patient with anaemia, thrombocytopenia and marginally decreased leucocyte count, who was found to have low copper levels. In addition, he had isolated 20q deletion and a small paroxysmal nocturnal haemoglobinuria clone, which have not been reported previously. His counts normalized after steroid therapy followed by copper supplementation. This case is presented to highlight the fact that copper deficiency may be present without the characteristic morphologic changes, and may be coexisting with other abnormalities.

The novel N,N′-ligand (BSI) is air-stable, easily available and highly modulated with low copper loading.

A graphite furnace atomic absorption spectrometry ( GF AAS ) method was developed for the determination of copper in selected alternative materials. The method is characterised by a low limit of detec tion, good accuracy and satisfactory precision, while the duration of a single measurement is approximately 80 s. It allowed an application of the developed method to determine copper in small samples of hair and nails with equipment available in most analytical labora tories. The developed GF AAS method was successfully applied to routine analyses using samples collected from healthy humans. The study has shown similar con centration of copper in fingernails and toenails collected from women and men, which was 2–3 times lower than concentration of this element in hair of both genders. The correlation between concentration of copper in nails and hair allows one to use hair, fingernails an d toenails as invariable materials for the evaluation of chronic exposure to copper.

The concentrated winding configurations offer significant advantage for reducing end windings. These machines are generally used in low speed high torque application due to relatively low copper loss. However, numbers of fractional slot construction make the designer hard to properly choose pole and slot numbers for the certain application. This paper provides the general information of possible fractional slot concentrated double layer winding machine.

The experiments of refractory copper oxide ore which comes from Tangdan of Yunnan Province were studied in laboratory using bulk flotation process and a new process that Ammonia leaching-Extraction-Electrode position-Residue flotation under normal temperature and pressure respectively. The results show that new process, compared with bulk flotation, had an effect to add 10.8 percent points to recovery. And then it is confirmed by industry experiment. So it is successfully applied to industry production and technology indicators were improved dramatically.

Copper (Cu) deficiency is associated with several disease syndromes, including poor growth, in farmed red deer ( Cervus elaphus ), but little is known of the consequences of low Cu levels in free-ranging populations. Low hepatic Cu levels have been documented in several wild red deer populations along the west coast of Norway, with the lowest values found on the island of Hitra. We studied the relationship between liver Cu concentration and slaughter weight in 63 red deer calves and 69 yearlings shot on Hitra during the autumn hunting season of 2009. Less than half of each age class had adequate Cu levels (20 μg/g dry weight) and 14% of the calves and 28% of the yearlings had levels indicating deficiency (13 μg/g). For yearlings, but not calves, there was a significant increase in slaughter weight with increasing hepatic Cu level. The differences between yearlings and calves could be linked to differences in physiologic Cu status of the two age classes, in that red deer calves are born with much higher levels of hepatic Cu than are their mothers. Our data demonstrate an association between low levels of Cu and reduced growth rate in a free-ranging cervid population.

We aimed at assessing whether the binding and rhizotoxicity of metal cations such as copper that exhibit high affinity for plant roots could be adequately predicted using the Windermere Humic Aqueous Model (WHAM) default parameterization. Accordingly, we first compared the ability of the default parameterization of WHAM and a specific parameterization for terrestrial higher plants (WHAM-THP) to model the competitive binding of copper on wheat (Triticum aestivum L.) and tomato (Solanum lycopersicum L.) roots. Secondly, in an external dataset, we evaluated the ability of WHAM-THP to predict the copper concentration and toxicity to pea (Pisum sativum L.) roots relative to WHAM. WHAM-THP estimates generated a slightly better fit for the competitive binding of copper on wheat and tomato roots (log10 of the root-mean-square error, RMSE = 0.15) than WHAM estimates (RMSE = 0.24). WHAM-THP estimates slightly better fitted the copper concentration in pea roots (RMSE ≤ 0.49) than WHAM estimates (RMSE ≤ 0.67) at low copper exposure and pH ≤ 5. However, WHAM-THP did not at all improve the prediction of copper toxicity to pea roots (RMSE = 13% as also for WHAM). We thus conclude that, although the default parameterization of WHAM does not neatly predict the binding of metal cations on roots, it could however be used with confidence in predictive ecotoxicology for terrestrial higher plants without any specific parameterization.

Traditional methods of ore mining in the underground mine Jama Bor cannot be applied to the ore body Borska reka for several reasons: the position of the ore body to the terrain surface, mining infrastructure and proximity of settlements, physical-mechanical properties of rocks in the ore body, economic viability, ore recovery, etc. In addition to the above, it should be taken into account that this is the ore body with low copper content, so it is necessary to choose a method for mass excavation. Due to these reasons, the mining method of ore was selected with backfilling of excavation area with paste backfill of certain physical-mechanical properties. This work will be present the test results of uniaxial compressive strength of paste backfill, as one of the most important properties and how this parameter varies depending on the change in balance of components of which a paste backfill is made. Tests were conducted on a number of different recipes for paste backfills and the backfill with 5% cement, 24% water and 71% uncycloned flotation tailings was selected as the best one.

Rescue excavations in Prohear, southeast Cambodia, recently saved the last untouched graves of one of the richest prehistoric sites in Southeast Asia. Many Iron Age burials dating from the 2nd century BC to the 1st century AD contained gold and silver ornaments so far unknown from archaeological contexts together with indications for the presence of an immigrated elite. A first selection of 59 objects were analysed by LA-ICP-MS to obtain detailed information about the composition, as well as minor and trace elements. The majority of the ornaments consist of electrum and auriferous silver with low copper concentrations, and two main groups indicating different alluvial gold sources can be distinguished by different concentrations of Pt, Ir, Bi and different Pd/Pt ratios, one group being related to rich burials with non-local features. The SEM and EDX analyses of four objects revealed two different gilding techniques observed for the first time in Southeast Asian artefacts: foil-fusion gilding, related to special Ag–Au–(Cu)–Sn alloys containing up to 4% tin, and depletion gilding.

The effect of Cr and Yb additions on microstructure and properties of low copper Al–Zn–Mg–Cu–Zr alloy has been investigated. Additions of Cr and Yb to low copper Al–Zn–Mg–Cu–Zr alloy could form 10–20 nm spherical coherent dispersoids, which identified as Zn, Mg, Cu, Cr, Yb-containing Al3Zr with cubic L12 structure. The dispersoids remarkably inhibit recrystallization of Al matrix. The unrecrystallized Al–Zn–Mg–Cu–Zr–Cr–Yb alloy greatly enhanced mechanical properties and fracture toughness as well as the resistance for stress corrosion cracking, compared to Al–Zn–Mg–Cu–Zr alloy.

A general, straightforward, and practical access to multi-substituted chiral quinoxalin-2-ones has been achieved based on the copper(I) chloride-dimethylethylenediamine (DMEDA) catalyst system. With the use of 1 mol% copper(I) chloride, structurally diverse quinoxalin-2-ones were generated with high optical purity from readily available starting materials, 2-haloanilines and α-amino acids, in a one-pot manner.

Single crystal of Cu0.03TaS2 with low copper intercalated content was successfully grown via chemical iodine-vapor transport. The structural characterization results show that the copper intercalated 2H-Cu0.03TaS2 single crystal has the same structure of the CdI2-type structure as the parent 2H-TaS2 crystal. Electrical resistivity and magnetization measurements reveal that 2H-Cu0.03TaS2 becomes a superconductor below 4.2 K. Besides, electrical resistivity and Hall effects results show that a charge density wave transition occurs at TCDW = 50 K., Comment: 14 pages, 6 figures,revised version

Copper was determined in the blood of breeding camels, camel calves and racing camels to evaluate copper status in these animals in UAE. Low blood copper concentrations were reported in newly born camel calves (100%) and calves 2-4 months old (68%), breeding camels at early (55.6%) and at mid lactation (48%) and at late pregnancy (69%). This is attributed to the low copper and high sulfate in the Rhodes grass which is the only diet offered to the breeding camels. On the other hand only 9.7% of racing camels showed low copper levels. This is because copper is routinely offered to racing camels when their blood copper is low. Cupric oxide needle capsules orally administered at the rate of 8 g per adult camel was effective in elevating blood copper from 7.083 micromol/L at day zero to 10.074 micromol/L at day 28 after dosing.