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The present work evaluates the reagents and appropriate conditions in order to obtain flotation concentrates with high copper content and low arsenic recovery. The studied ore is a blend of 80 % w/w El Valle ore and 20 % w/w Carlés ore, this latter being rich in copper and arsenic content. Those ores are worked from two deposits located in Asturias-Spain and treated at a concentration plant nearby. The arsenic content in the floated concentrate is penalized by the buyer. The main conclusion from the study is that a dithiophosphate is the collector that provides the best results, what was confirmed at plant-scale.El objetivo del presente trabajo es definir los reactivos y las condiciones apropiadas para obtener concentrados con alta ley de cobre y baja recuperación de arsénico, a partir de muestras de una mezcla con 80 % en peso de una mena de oro, cobre y bismuto, y 20 % en peso de otra mena rica en oro y cobre, pero con alta ley de arsénico, provenientes de los yacimientos El Valle y Carlés, ubicados en Asturias-España, y procesados en una planta de concentración. La presencia de arsénico en el concentrado flotado es penalizada por sus compradores. La principal conclusión del trabajo es que un ditiofosfato como único reactivo colector es el que logra alcanzar el objetivo planteado, lo que se comprobó con pruebas en la planta de concentración.

Oxidative leaching of a solid product of copper refining was studied in a laboratory, with autoclave oxidation replaced with that in the atmosphere. The extent of the chemical reactions that occur in atmospheric oxidative leaching and autoclave refining in the technology of sulfate leaching of high-copper converter matte was determined.

Open-loop hydronic heating systems have been found to provide a breeding ground for bacteria, including bacteria associated with microbiologically influenced corrosion (MIC). Microbiologically influenced corrosion of brass fittings, which may contain up to 8% lead in potable water applications, has been linked to high copper and lead levels in water samples taken from the hydronic-loop tubing. The contamination is likely concentrated in slime deposits found within the tubing. These slime deposits can enter the potable water supply, resulting in potential copper and lead exposure levels considerably above Environmental Protection Agency (EPA) guidelines. The authors recommend that hydronic heating systems incorporate a closed-loop design to prevent personal exposure and to provide for use of corrosion-inhibiting additives.

Raziskan je bil vpliv bakra na mikrostrukturo zlitin AlCuMg. Uporabljene so bile metode DSC, difrakcija rentgenskiharkov, merjenje trdote, tla~ni preizkus in analiza na elektronskem mikroanalizatorju. Diferen~na vrsti~na kalorimetrija je bila uporabljena pri zlitinah AlCu5Mg2, AlCu5Mg4, AlCu15Mg2 in AlCu15Mg4 z dodatkom 0,25 % Ti. DSC-krivulje so pokazale endotermne efekte, ki so bili uporabljeni za izra~un tranzicijske entalpije. Difraktometrijska analiza je pokazala tetragonalno intermetalno fazo Al2Cu v zlitini AlCu15Mg2 in ortorombi~no fazo Al2CuMg v zlitinah AlCu5Mg2, AlCu5Mg4 in AlCu15Mg4. Klju~ne besede: zlitine aluminij-baker-magnezij, intermetalni spojini Al2CuMg

The main purposes of this research are to establish the extent and character of copper spray use in the viticulture industry in New Zealand; and to determine the level of copper accumulation nationally and in the main viticultural regions. The research also included pilot investigations of the storage of copper on different soil fractions and changes in nutrient status of vineyard soils with high copper concentrations. A questionnaire survey was completed by 124 growers from throughout the country. Copper sprays are still used in the majority of cases, but have either never been used or are no longer used in almost 30% of vineyards covered in the survey. Where copper is used, the load being applied to the vines each year varies widely, but the impression is that most growers are moderate in their use of copper. There are geographical patterns in use, and there is some evidence that newer vineyards, often in drier areas, are applying lower rates of copper, and less frequently. The maximum soil copper conce...

Zambia has experienced very good GDP growth rates in the last decade, above the SSA average. Growth remains largely based on copper exports, and on the high copper price that prevailed until 2013. The country has not yet achieved structural transformation of its domestic economy, in particular with regard to its ambition for broader based industrialization. There are important changes in demand with urbanization and increasing household incomes, in Zambia as well as in the neighboring DRC. A review of trade patterns and the sectoral performance in Zambia assesses the size and direction of different effects on patterns of industrial development. It particularly considers the impact on agro-processing and engineering sectors and the key factors in development of these activities. The paper considers concerns relating to competition, investment along the value chain, and the ability to build capabilities based on local demand and export opportunities in regional markets, especially in South Africa and via regional supermarket chains. Based on this analysis the paper asks what policies are required to support broad-based industrialization and critically assesses the existing framework and its implementation in this light. It concludes by considering the potential for collaboration in industrial policy across countries.

Introduction: Chromhidrosis is a rare sweat gland disorder charac­terized by the excretion of colored sweat. It can be classified as apocrine, true eccrine, and pseudochromhidrosis. Amongst the different types of chromhidrosis, green chromhidrosis is extremely rare. We describe herein a case of blue green chromhidrosis induced by ingestion of homeopathic medicine. Case report: A middle aged man presented to us with blue green discoloration of hands and feet. There was a preceding history of ingestion of homeopathic medication. Histopathology from the involved skin showed greenish particles within eccrine glands. Initial blood copper level was high which returned to normal level after discontinuation of the homeopathic medicine. Spectrophotometry revealed high copper content of the green sweat. Conclusion: Our case emphasizes the importance of considering any type of ingested medicine, including homeopathic medicine, as a probable cause of chromhidrosis.

Slags from the El Teniente Converter have high copper and magnetite contents. The reduction and copper impoverishment of these slags in an electric furnace were simulated in the laboratory as part of a conceptual study for the Las Ventanas Smelter of ENAMI. The effects of power input, electrode immersion, slag temperature and coke and solid revert additions on the rate of magnetite reduction and copper recovery were investigated. It was found that the rate of slag reduction is strongly dependent on electrode power density. The addition of solid reverts containing copper matte enhanced the recovery of copper. Magnetite stratification and a corresponding gradient in copper content occurred in the slag. The experimental results, combined with an analysis of the phenomena taking place in an electric furnace, led to an improved understanding of the slag cleaning mechanism and contributed to the successful start up of the slag cleaning electric furnace at the Las Ventanas Smelter.

The fracture toughness of two high copper reactor pressure vessel welds having low upper shelf energy was evaluated in accordance with the master curve method of ASTM E1921. The resultant data were correlated to the metallurgical factors involved in the brittle fracture initiation to provide a metallurgical-based understanding of the master curve. The tests were performed using pre-cracked Charpy V-notched specimens and the master curve was made with an average of T 0 values determined at different temperatures. In all specimens, the cleavage fracture initiated at non-metallic inclusion ranging from 0.7 to 3.5 μm in diameter showing a scatter with the specimens and testing temperatures. Temperature dependency of the triggering particle size was not found. The fracture toughness ( K J C ) was inversely proportional to the square root of the triggering inclusion diameter ( d i ) at respective temperatures. From this relationship, we determined median K J C values which correspond to the average value of triggering inclusion diameter of all tested specimens and defined them as a modified median K J C ( K ′ J C (med) ). The obtained K ′ J C (med) values showed quite smaller deviation from the master curve at different temperatures than the experimental median K J C values. This suggests that the master curve is on the premise of a constant dimension of key microstructural factor in a material regardless of the testing temperature. But the inclusion size at trigger point played an important role in the absolute position of the master curve with temperature and the consequent T 0 value.

Copper is both essential for life and toxic. Aberrant regulation of copper at the level of intracellular transport has been associated with inherited diseases, including Wilson's disease (WND) in humans. WND results in accumulation of copper and the copper and zinc-binding protein metallothionein (MT) in liver and other tissues, liver degeneration, and neurological dysfunction. The toxic milk (TX) mutation in mice results in a phenotype that mimics human WND, and TX has been proposed to be a model of the disease. We characterized TX mice as a model of altered metal ion and MT levels during development, and after treatment with the metal ion chelators tetrathiomolybdate (TTM) and deferiprone (L1). We report that hepatic, renal and brain copper and MT are elevated in TX mice at 3 and 12 months of age. Zinc was significantly higher in TX mouse liver, but not brain and kidney, at both time points. Nodules appeared spontaneously in TX mouse livers at 8-12 months that maintained high copper levels, but with more normal morphology and decreased MT levels. Treatment of TX mice with TTM significantly reduced elevated hepatic copper and MT. Transient increases in blood and kidney copper accompanied TTM treatment and indicated that renal excretion was a significant route of removal. Treatment with L1, on the other hand, had no effect on liver or kidney copper and MT, but resulted in increased brain copper and MT levels. These data indicate that TTM, but not L1, may be useful in treating diseases of copper overload including WND.

The copper ion conducting argyorite-type title compound is synthesized from the elements (evacuated quartz ampule, 1323 K, 3 h, and 773 K, 72 h) and its thermoelectric transport properties are studied.

The rapid growth of smartphones and tablets in mobile market demands the packaging technology to be in a thinner profile with small form factor and reduce power consumption. The PoP structure is widely used in the package of smart phones to connect memory and Application Processor. Even if TSV is the preferred structure for connecting memory and AP, the high cost of TSV process prohibit TSV for wide presence in the smart phone applications. Recently, I/Os of memory are required to increase from a few hundreds to more than 1000. For wide I/O2, I/Os more than 2000 may be required. We have demonstrated PoP connections over 1000 with pitch of 200 um in last year's ECTC conference with Unimicron HCP (High Copper Pillar) technology [1]. In preparation to meet future memory requirement and to evaluate the extendibility of Unimicron proposed HCP structure, a test vehicle has been built. The test vehicle consists of a PoP structure with a fine pitch of 100 μm that can support 2472 I/Os in 6 rows around the peripheral area of the die. The package size is in a 12×12 mm 2 CSP format. The target copper pillar height is 80 μm. The copper pillars with a designed diameter of 70 μm and space of 30 μm. The uniformity of copper pillar height is required to assure the reliable interconnections between the top memory die and the bottom AP. For a designed copper pillar height of 80 μm, tolerance of +/-15 μm is required. In this paper, a method to achieve the copper height uniformity of +/- 15 μm with 100 μm PoP pitch connection will be demonstrated.

Characteristics and mechanisms of PCDD/F formation with different feed materials in secondary copper smelting industry are investigated. The results indicate that PCDD/Fs are significantly formed even with the reaction time less than 0.1s, especially when the material containing high residues (Cu3) is fed. High copper content (65±2%) in the feed material enhances PCDD/F formation rate. Memory effect and de novo synthesis are two important mechanisms leading to PCDD/F formation. PCDD/F concentrations at the cyclone's inlet are between 2.92 and 12.4ng-TEQNm(-3) and increase with increasing residue content in the feed material. Two regions are identified for high potential of PCDD/F formation including the brass melt surface of the induction furnace and piping before the induced draft fan of the inlet hood. PCDD/Fs in flue gas are effectively removed with a cyclone and bag filter at low operating temperatures (60°C) to meet the emission limit of 1.0ng-TEQNm(-3). 1,2,3,4,6,7,8-HpCDF has the largest mass fraction of PCDD/Fs and can serve as a fingerprint for emissions from secondary copper smelting processes. The total emission factor of PCDD/Fs from flue gas, residual and fly ash in the secondary copper smelting process investigated is 22.01μg-TEQtonne(-1).

O cobre, em níveis supranutricionais nas dietas de frangos de corte, atua como promotor do crescimento. Para avaliar as respostas no desempenho e no colesterol sérico e muscular de frangos de corte, 1200 pintos (600 machos e 600 fêmeas) receberam rações suplementadas com 50, 100 ou 150 mg kg-1 de cobre como citrato cúprico, ou 200 mg kg-1 de cobre como sulfato cúprico pentahidratado, ou uma dieta controle, não suplementada, em um experimento em blocos casualizados com três repetições e arranjo fatorial de cinco tratamentos e dois sexos. As rações, baseadas em milho e farelo de soja e adequadas em todos os nutrientes (12 mg kg-1 de cobre na dieta controle), e água foram fornecidas à vontade durante o experimento de 42 dias. Não houve efeito (P>0,05) de tratamentos nas variáveis ganho de peso, consumo de ração (CR), conversão alimentar (CA) e mortalidade + refugagem (M+R) nos períodos de 1 a 21 dias e de 22 a 42 dias, com valores médios de 0,778 e 1,501 kg para GP, 1,181 e 3,087 kg para CR, 1,540 e 2,060 para CA, 1,42 e 2,08 % para M+R, respectivamente. Ao final do experimento o peso vivo (2,310 kg), o ganho de peso diário (55 g), o fator de produção (282,2), o colesterol no soro sangüíneo (129 mgdL-1) e o colesterol no músculo (55,9 mg 100 mL-1) também não foram afetados pelos tatamentos (P>0,05). Os machos e as fêmeas tiveram níveis semelhantes de colesterol (P>0,05) no soro e no músculo.

Comparison of the kinetic profiles of copper-induced peroxidation of HDL and LDL at different copper concentrations reveals that under all the studied experimental conditions HDL is more susceptible to oxidation than LDL. The mechanism responsible for HDL oxidation is a complex function of the copper/HDL ratio and of the tocopherol content of the HDL. At high copper concentrations, the kinetic profiles were similar to those observed for LDL oxidation, namely, relatively rapid accumulation of oxidation products, via an autoaccelerated, noninhibited mechanism, was preceded by an initial “lag phase.” Under these conditions, the maximal peroxidation rate (Vmax) of HDL and LDL depended similarly on the molar ratio of bound copper/lipoprotein. Analysis of this dependency in terms of the binding characteristics of copper to lipoprotein, yielded similar dissociation constant (K = 10−6 M) but different maximal binding capacities for the two lipoproteins (8 Cu+2/HDL as compared to 17 Cu+2/LDL). Given the size difference between HDL and LDL, these results imply that the maximal surface density of bound copper is at least 2-fold higher for HDL than for LDL. This difference may be responsible for the higher susceptibility of HDL to copper-induced oxidation in the presence of high copper concentrations. At relatively low copper concentrations, the kinetic profile of HDL oxidation was biphasic, similar to but more pronounced than the biphasic kinetics observed for the oxidation of LDL lipids at the same concentration of copper. Our results are consistent with the hypothesis that the first phase of rapid oxidation occurs via a tocopherol-mediated-peroxidation (TMP) mechanism. Accordingly, enrichment of HDL with tocopherol resulted in enhanced accumulation of hydroperoxides during the first phase of copper-induced oxidation. Notably, the maximal accumulation during the first phase decreased upon increasing the ratio of bound copper/HDL. This behavior can be predicted theoretically for peroxidation via a TMP mechanism, in opposition to autoaccelerated peroxidation. The possible pathophysiological significance of these findings is discussed.

The early stages of precipitation after solution treatment and quenching have been studied in two age-hardenable high-purity AlCuMg alloys having a Cu content of 4.5 wt% and Cu/Mg ratio of 2.6 and 8, by DSC, TEM and hardness measurements. The investigation has been performed by carrying out DSC scans immediately after quenching and at increasing times at room temperature up to the first sudden hardness increase. The analysis of the DSC traces clearly indicates for both compositions that the progressive disappearance of an exothermal precipitation peak at about 80°C in the as-quenched samples is associated with the hardness increase observed at room temperature. TEM observations performed after ageing at room temperature for 48 h indicate that the thermal effect associated with the initial hardness increase is due to the zones formation. It is therefore concluded that in the investigated alloys the classic mechanism so far accepted involving an interaction between zones and dislocations should be still accepted in order to justify the hardness increase in the early stages of precipitation, although the presence of atoms clusters cannot be excluded.

PrP(C), the normal isoform of the prion component PrP(Sc), is a 33-35-kDa glycophosphatidylinositol-anchored glycoprotein expressed in the plasma membrane of many cells and especially in the brain. The specific role of PrP(C) is unknown, although lately it has been shown to bind copper specifically. We show here that PrP(C) is present even in mature sperm cells, a polarized cell that retains only the minimal components required for DNA delivery, movement, and energy production. As opposed to PrP(C) in other cells, PrP in ejaculated sperm cells was truncated in its C terminus in the vicinity of residue 200. Sperm PrP, although membrane-bound, was not released by phosphatidylinositol phospholipase C as well as not localized in cholesterol-rich microdomains (rafts). Although no infertility was reported for PrP-ablated mice in normal situations, our results suggest that sperm cells originating from PrP-ablated mice were significantly more susceptible to high copper concentrations than sperm from wild type mice, allocating a protective role for PrP in specific stress situations related to copper toxicity. Since the functions performed by proteins in sperm cells are limited, these cells may constitute an ideal system to elucidate the function of PrP(C).

Fundamental in vitro wear tests are important for the study of wear mechanisms, provision of data during material development and screening of materials prior to clinical trials. The aim of this project was to compare the wear of six dental restoratives using the BIOMAT wear simulator which was developed to simulate jaw movements and stresses generated in the occlusal contact areas during the chewing process. The correlation of wear to hardness of the restoratives was also assessed. Wear ranking from the least to the most volumetric wear was as follows: high copper unicompositional alloy, Tytin® (T) < high copper admixed alloy, Valiant PhD® (V) < microfilled composite resin, Silux Plus® (S) < gallium alloy, Galloy® (G) < heavily filled composite resin, Z100® (Z) < hybrid composite resin, P50® (P). The high copper amalgam alloys had significantly greater wear resistance when compared with all the composite resins. The gallium alloy, microfilled and heavily filled composite resins also exhibited significantly less wear than the hybrid resin. Wear ranking with the BIOMAT simulator was similar to that obtained in vivo. Ranking from the hardest to softest material: high copper unicompositional alloy, T < gallium alloy, G < high copper admixed alloy, V < hybrid composite resin, P < heavily filled composite resin, Z < microfilled composite resin, S. The amalgam alloys were significantly harder than the heavily filled and microfilled composite resins. There was no apparent correlation between wear performance and material hardness.

Metallographic studies carried out for Tytin-Plus and Dispersalloy amalgams show a porous multiphase material, whose surface phases are: γ -(Ag 3 Sn), γ 1 -(Ag 2 Hg 3 ), η ′-(Cu 6 Sn 5 ) and e -(Cu 3 Sn). Additionally, Dispersalloy is present in the Ag–Cu eutectic. The application of surface analysis by SEM reveal a heterogeneous distribution of the above mentioned phases. Microstructures consisting of colonies or clusters were not observed. The corrosion testing of these materials was done in 0.9% NaCl aerated solution at 25°C using potentiodynamic polarization curves and ac impedance measurements. The corrosion process in these multiphase systems can be interpreted as the sum of more than one electrodissolution process and the posterior formation of corrosion films. On each electrode, the corrosion film is formed by different mechanisms.

Alginate beads and those immobilised with Chlorella vulgaris were suitable for repeated adsorption/desorption cycling for copper under batch conditions. Consistently high copper removal (>95%) and recovery (100% using 0.1 M HCI) were achieved in five consecutive cycles. Majority copper was adsorbed by alginate matrix, not the cells. Freely suspended cells were difficult to handle in repeated cycling, and given inconsistent copper removal and recovery. Heat killed cells performed the same as initially live cells after the first cycle. © Rapid Science Ltd. 1998

Background: Oral Squamous cell carcinoma (OSCC) is often preceded by potentially malignant disorders (PMDs) like oral submucous fibrosis (OSMF). The rate of transformation of OSMF to OSCC ranges from 3 to 19%. OSMF is etiologically related to chewing of areca nut (betel nut), a habit prevalent among the population groups in south-east Asia. Along with alkaloids, the high copper content in areca nut plays an important role in the pathogenesis of OSMF. The increased prevalence of OSMF in the last two decades or so corresponds with the increased processing and commercialization of areca nut products. Aim: The aim of the study was to estimate and compare the copper content of raw areca nuts in three different stages of maturity, and commercial areca nut products. Materials and Methods: Raw areca nut samples of three different maturities were obtained from four plantations in Sullia, Karnataka, India and commercial areca nut products were obtained from local shops in Chidambaram, Tamil Nadu, India. The samples were grounded and subjected to Atomic Absorption Spectrometry (AAS) for copper analysis. Results: There was statistically significant difference in copper content in raw areca nuts of all three maturities (p

The surface margin of a restoration is where the restored tooth is subjected to aggressive oral attack. Any resistance to this attack will have favorable consequences on the clinical performance and longevity of the restoration. In this study, Black's class I classic cavity preparations were completed in 120 extracted intact human premolars that were restored with one of two silver amalgams, six different base conditions, and with or without cavity varnish, resulting in 20 different restoration combinations. The cavities were aged for 3 months and 1 year in 1% NaCl at 20 degrees C. A resin cast impression was made of the restoration margin for each specimen. Thereafter 80 restored teeth were subjected to an in vitro bacterial challenge for 36 days. The other 40 specimens were placed in an acidified (pH = 4.0) broth for the same length of time. A second cast impression was then made of the margin of each specimen. The casts were examined with a scanning electron microscope and the widest gap of the margin opening and the length of margin showing a discrepancy were measured. Specimens were ranked first on the basis of the gap size and then on percent of margin discrepancy length. Results were evaluated with one-way ANOVA and Turkey's Student range test with a critical level of statistical significance (p < 0.05). Base type significantly affected aged margin quality. Cariogenic challenge caused a significant breakdown of the amalgam margin although the type of challenge was not significant. A shorter aging time, varnish, and high copper amalgam exacerbated the breakdown. Margin breakdown can be reduced by judicious selection of restoration material combinations.

In this paper the effect of ultraviolet (UV) light irradiation on the optical, photoelectrical and electret properties of CdBr2 : Cu+ single crystals has been investigated. It has been found out that in CdBr2 : Cu+ crystals some copper impurity ions are part of dipoles. The action of UV light which causes colouring of the CdBr2 : Cu+ crystals destroys these dipoles. The obtained experimental results show that in CdBr2 : Cu+ crystals with low and high copper impurity concentrations photochemical reactions are caused basically by charge exchange of the copper centres.

A marginal gap exists between the amalgam restoration and the cavity walls. At this interface, there is a constant percolation of fluid containing ions, molecules and bacteria. With time, corrosion products of the amalgam components seal the gap at the amalgam/tooth interface. The corrosion processes for conventional and high copper amalgam and factors affecting the corrosion deposits are reviewed. Better amalgam adaptation to the cavity walls improves the chances of sealing the restoration by corrosion products. The effectiveness of cavity varnish in preventing microleakage until corrosive deposits are formed is discussed.

Lamb copper status is commonly assessed by measuring copper concentrations in four liver samples collected from lines of lambs sent to meat slaughtering premises. High liver copper concentrations were found in lambs examined in April and May. Five farms with two or more lamb liver copper concentrations greater than 3000 𝛍mol/kg on a wet matter basis and two farms with adequate copper concentrations but less than 3000 𝛍mollkg in the autumn of 1992 were selected for a more detailed investigation into the factors affecting their lamb copper status in 1993. High liver copper status was associated with low pasture molybdenum, grazing paddocks recently topdressed with copper sulphate, supplementing with mineralised drenches and copperised salt licks, and the high copper content in chicory. Lamb liver copper concentrations were significantly (pp

A precision-fed cockerel digestibility assay using ground corn cobs was conducted to test a theory that birds fed pharmacological doses of Cu (250 mg Cu/kg diet) may exhibit a higher hemicellulose digestibility due to increased release of lysosomal enzymes in the bile. Finely ground corn cobs were crop intubated into adult cockerels that had been pretested on diets containing either 0 or 250 mg Cu/kg (from CUSO4.5H2O). Copper-loaded cockerels showed higher (P.05) true dry matter digestibility, hemicellulose digestibility, and TMEn than the control cockerels. True dry matter digestibility of corn cobs was 11.1% in Cu-loaded cockerels, which was nearly double that observed (6.2%) in control cockerels. Hemicellulose digestibility also increased from 22.1% in control cockerels to 36.6% in Cu-loaded cockerels. Copper-loaded cockerels obtained some TMEn (117.7 kcal/kg) from corn cobs, whereas the control cockerels obtained no TMEn from the corn cob intubation. The preliminary results presented herein demonstrate that pharmacological doses of dietary Cu may improve hemicellulose digestibility, which may in part explain the growth-promoting effect of Cu.

International audience; The deeper understanding of the factors that affect the dimensionless figure of merit, ZT, and the use of new synthetic methods has recently led to the development of novel systems with improved thermoelectric performances. Albeit up to now with ZT values lower than the conventional bulk materials, semiconducting glasses have also emerged as a new family of potential thermoelectric materials. This paper reviews the latest advances on semiconducting glasses for thermoelectric applications. Key examples of tellurium-based glasses, with high Seebeck coefficients, very low thermal conductivities and tunable electrical conductivities, are presented. ZT values as high as 0.2 were obtained at room temperature for several tellurium-based glasses with high copper concentrations, confirming chalcogenide semiconducting glasses as good candidates for high-performance thermoelectric materials. However, the temperature stability and electrical conductivity of there ported glasses are still not good enough for practical applications and further studies are still needed to enhance them.

A filling is the repair of a damaged or decayed tooth, restoring it back to its normal shape, appearance and function. Amalgam Restoration is an example of the material giving its name to the process. Amalgam fillings are made up of mercury, powdered silver and tin. They are mixed and packed into cavities in teeth where it hardens slowly and replaces the missing tooth substance. This article throws light on high copper alloys of amalgam, its advantages, disadvantages and contraindications. A review of some patents on amalgam is also provided that summarizes the recent technical advancements taken place in this area.

Background: Copper and selenium are important trace elements in man. They function as antioxidants and play roles in oxido-reductase reactions. Several imported multivitamin preparations are given to our women during pregnancy and lactation to correct possible deficiencies.Objective: The aim of the study is to determine the serum level of these micronutrients (selenium and copper) in a cross section of pregnant women in Enugu, southeastern Nigeria.Materials and Methods: A cross section of 130 healthy pregnant women at different trimesters of pregnancy and 30 non-pregnant controls were selected from two health facilities in Enugu, southeastern Nigeria. Serum from the samples collected was assayed for copper and selenium using atomic absorption spectrophotometer.Results: The mean copper level increased (P = 0.018), while the selenium level decreased (P < 0.0001) as pregnancy advanced.Conclusion: High copper levels indicate that supplementation should not be undertaken during normal pregnancy. Dietary intake should be modified to ensure optimal selenium levels during pregnancy.

This paper presents the laboratory testing of slag samples from the 'Slag Depot 1', located in the industrial site of RTB Bor. Testing revealed a separation of copper matte with high copper content, as well as the separation of elemental copper. Due to the better economic effects, should be considered a possibility of physical concentration method of copper matte has to be considered, based on its physical and chemical properties.

During 1992 and 1993 the Wisconsin Division of Health investigated five cases in which copper-contaminated drinking water was suspected of causing gastrointestinal upsets. Each of these case studies was conducted after our office was notified of high copper levels in drinking water or notified of unexplained illnesses. Our findings suggest that drinking water that contains copper at levels above the federal action limit of 1.3 mg/l may be a relatively common cause of diarrhea, abdominal cramps, and nausea. These symptoms occurred most frequently in infants and young children and among resident of newly constructed or renovated homes. Images p958-a

The conditions required for the formation of copper sulfide originating from the DBDS oil additive which was identified by Scattigio (Terna, Italy) in 2005 is: “sufficiently high copper temperature” and copper corrosion will appear. This paper describes the findings when a transformer allegedly failed by corrosive sulfur was inspected with regards to the presence of copper corrosion. Strong corrosive attacks were found and their relation to temperature was very evident.

The effect of different sodium chloride concentrations on the integrated currents (charge transfers) between dental amalgams and a gold alloy was studied in a bimetallic cell containing saliva or saline solutions. The integrated currents were only to a minor degree affected by increasing chloride concentrations for the high copper amalgams both in saliva and saline solutions. The integrated currents in the experiments involving conventional amalgam were several times higher than those for high copper amalgams. In saline solutions a charge transfer maximum was found at 0.2 M chloride. In saliva an increase of the charge transfer was found with increasing chloride content.

Renal, skeletal, cardiac, and ophthalmic involvement in Wilson disease (WD) is well known. In this case report, high copper content and ultrastructural findings of skin of a patient with WD accompanied by xerosis are presented.

Results of metals flammability tests performed on twenty-six metals in the NASA/White Sands Test Facility are discussed together with the test systems. The promoted combustion and ignition characteristics of these metals are described, and the metals are ranked according to their suitability for use in oxygen systems. In general, alloys with high copper and nickel contents and low iron content were found to rank higher than those that had high iron content, while alloys that had high aluminum content were ranked the lowest.

High copper content is of great concern among producers of sugar-cane spirits who frequently use filters instead of cleaning the stills. This study compared the efficiency of activated carbon, ion-exchange-polymeric resin, and activated-carbon/iron-oxide magnetic composite for copper reduction without removing excessive organic compounds that are important for the beverage's quality. Resin was the most efficient copper adsorbent, removing fewer organic compounds. The composite also removed copper; however, it also removed large amounts of organic compounds. Activated carbon didn't remove sufficient copper to reduce its concentration to less than 5 g L-1, and it removed large amounts of higher alcohols and esters.

Copper sulfate was applied to freshwater fishponds containing allogyno- genetic silver crucian carp and changes in the copper content in fish tissues were measured. The copper content in blood, gill, amd liver went up quick- ly, but remained high for a relatively short time. Twenty-four hours after application, the copper content in the gill and liver reached their highest lev- els, 4.846 mg/kg and 6.624 mg/kg, respectively. The copper content in the blood reached its maximum of 22.125 mg/l three days after application. The copper content in the kidney also reached its maximum, 17.472 mg/kg, on day 3 but the high copper content prevailed until the end of the 20-day observation. The copper content in the muscle reached its maximum, 1.873 mg/kg, on day 7 and its minimum, 0.6 mg/kg, after two weeks.

Samples were taken from 72 high-rise apartment suites (6 suites in 12 individual high-rise towers) and 60 single-family houses located within the Greater Vancouver Regional District. The influence of the following factors on trace metal concentrations in 1-L first-flush drinking water samples and “running” hot water samples was investigated: building height, location, plumbing age, type of plumbing, and type of building. Results of this survey show that with the exception of building height, all factors had a correlation with one or more of the trace metals investigated. The trace metals examined were lead, copper, iron, and zinc. Lead was influenced primarily by building type, copper by plumbing age and type of plumbing, and iron by location. Elevated lead levels were associated with high-rise samples. New copper plumbing systems resulted in high copper levels. Highest iron levels in the drinking water were measured in the East Vancouver location. Zinc did not show a distinct correlation with any of the factors investigated. Brass faucets were the primary source of zinc in tap water. They also contributed substantially to the lead detected in the 1-L first-flush sample. Metal concentrations measured in the high-rise and house samples were compared with the U.S. Environmental Protection Agency's (USEPA) maximum contaminant levels (MCLs) and the proposed “no-action” level for lead. In high-rise samples, the 0.01 mg/L “no-action” level proposed for lead was exceeded in 43% of the samples, and 62% of the samples exceeded the current 1.0 mg/L MCL standard for copper. In single-family house samples, these values were 47% and 73%, respectively. The average lead concentrations were 0.020 mg/L for all high-rise samples and 0.013 mg/L for house samples. Regulatory levels stated above would still be exceeded in 6% of the cases for lead and 9% of the cases for copper, even after prolonged flushing of the tap in a high-rise building. In all cases associated with single-family houses, flushing the cold water tap for 5 minutes was successful in achieving compliance levels. Key words: aggressive water, compliance, corrosive, drinking water, first-flush, GVRD, high-rise, single-family house, trace metals, USEPA.

The replacement of low copper amalgams was studied in a number of general practices in Adelaide in 1975 duplicating, by design, the method of a similar Canadian study. The results of this study are in surprising agreement with the Canadian data, and are still relevant to modern practice as the high copper alloys have not proven to have greatly superior longevity. This study involved 60 dentists who, over 271 working days, replaced an average of 6.7 amalgam surfaces/dentist/day. This is equivalent to 1541 amalgam surfaces replaced/dentist/year. In addition, the reasons given for the removal of existing amalgam restorations were closely congruent with those given by the Canadian dentists. This study also indicated that many of these restorations increased in size. This is evident through restorations extending from two surfaces to involve three surfaces.

インド,ドイツ,北アメリカなどで地域的に発生する小児肝硬変の病因は,銅の経口過剰摂取であると考えられ,組織学的には肝小葉周辺性に銅沈着を認める.我々は,栄養状態と銅の関係に着目し,SDラットを低蛋白食群と通常食群に分け,胎児期から過剰な銅(酢酸銅35ppm,硫酸銅トリニトロ三酢酸2ナトリウム35ppmと7ppm)を8週間経口投与し,生後1,4, 8週の実験群につき検討した.通常食を与えた対照群では肝臓に銅の沈着はみられなかった.一方,低蛋白食群では8週で,通常食群に比し40倍以上の極めて高濃度の銅沈着が肝小葉中心性に認められた.低蛋白血症状態における銅負荷の病理組織像において,銅沈着分布は上記の銅蓄積型小児群硬変やWilson病,原発性胆汁性肝硬変と異なって肝小葉中心性であり,銅蓄積型小児肝硬変とは異なる機序によるものと考えられ,低蛋白食による肝小葉中心帯肝細胞障害,特に毛細胆管内への銅排泄障害が示唆された.

The objective of our study was to determinate the effect of copper on long-term potentiation (LTP) in hippocampus slices and a learning test in the Morris Water Maze (MWM). A group of adult Wistar rats received intraperitoneal (ip) injections of 1 mg/kg of CuSO(4) dissolved in saline for 30 consecutive days (Cu.R). A group of control rats (Sal.R), received saline by the same routes and duration. After this period, every individual of both groups was submitted to learning in MWM. Once the learning was completed, the LTP was studied in slices of hippocampus of both groups. The statistical assessment shows that the rats in both groups did not show significant differences in their progressive learning, notwithstanding that group Cu.R had 14.2 times more copper in their hippocampus and 16.7 times more in the visual cortices than in those of group Sal.R. On the other hand, the neurons of CA1 in hippocampus slices of Sal.R showed a significant development of LTP, but this was not observed in group Cu.R. In a second situation, 13 rats received training in MWM. Then, a group of 6 animals were injected with copper i.p. at the dose and time previously described. The 7 other animals were administered saline. Afterward, both groups were retrained in the MWM. The results obtained in Cu.R were similar to those obtained in Sal.R. Both groups maintained the concentrations of copper in the hippocampus indicated above, nonetheless, only the hippocampus slices of Cu.R did not show LTP. The spatial learning behavior of the rats was not affected by high copper concentration.

Dental restoration is a treatment in dentistry that very often implemented. One of the restoration materials used is an amalgam. Amalgam has some deficiencies, among others, the presence of free Hg. The purpose of this study was to find out the difference in Hg content released from two different kinds of amalgam, namely, high copper amalgam and silverfil argentum carried out in vitro. This study was carried out on thirty premolar teeth of the maxilla which underwent class one occlusal restoration. The Hg content released was measured using the Atomic Absorption Spectrophotometry (AAS). This was a quasi-experimental study. The study results analyzed using the independent t paired statistical test method indicated that after one week of immersion, the average Hg content released from high copper amalgam restoration was 10,695 ng/mL and from silverfil argentum restoration was 5,602 ng/mL. The conclusion of the study was that there was a difference in Hg content released from high copper amalgam restoration and silverfil argentum restoration. The Hg content released from high copper amalgam restoration was higher than the Hg content released from silverfil argentum restoration.

With the aim to examine their potentials as renewable resources to decontaminate polluted soils, growth, photosynthesis and nitrogen balance were analyzed in two poplar species (Populus x canadensis, Adda clone and Populus alba, Villafranca clone) to investigate the tolerance to high copper (Cu) concentrations. The two clones showed different responses to Cu in terms of tolerance and metal allocation: P. x canadensis accumulated Cu in roots, displaying features sought in plants suitable for phytostabilization, while P. alba accumulated the metal in leaves, like an indicator species.

In this study 767 amalgam restorations placed in the posterior permanent teeth of 122 patients were evaluated at 6-monthly intervals up to 2 years. Six commercially available high-copper alloy amalgams were assessed for surface roughness, surface tarnish, marginal staining and marginal fracture and the results were related to product, restoration age, restoration cavity class type, restoration size (normal or large Class II preparations) and tooth type (premolar or permanent molar). Dispersalloy (Johnson and Johnson, East Windsor, USA) gave restorations which were overall superior for the clinical characteristics examined. Large restorations on the occlusal surfaces of molar teeth showed more signs of deterioration over the study than did other restoration types. However, all restorations remained clinically satisfactory throughout the study.

An in-vitro study of marginal leakage around class V restorations, prepared in freshly extracted upper central incisors, tested two types of high copper amalgam: spherical high copper amalgam (Tytin) and spherical high copper amalgam containing palladium (Valiant). No significant statistical difference was noted between the two types of amalgam at the three testing periods. It seemed that the addition of palladium did not improve the marginal leakage.

Hydrogen peroxide is an effective agent to take off tooth colouring. This bleaching agent can cause microstructural change on amalgam restoration surfaces. The aim of this research is to know the difference of surface roughness of high-copper amalgam restoration materials before and after 38% hydrogen peroxide application by in-office bleaching technique. The sample was used consist of ten specimens of high-copper amalgam restorations which was applied by hydrogen peroxide 38%. The surface roughness was measured by the surface tester (Surtronic 3P). The result of this research was reached by t-test paired calculation is the differences of surface roughness of amalgam restorations before and after first 15 minutes either second 15 minutes hydrogen peroxide 38% application didn’t show significant differences. The conclusion of this research is no statistically significant difference of surface roughness of high-copper amalgam restoration materials before and after 38% hydrogen peroxide application by in-office bleaching technique.