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Sample records for copper concentrate clouds

  1. China Resumes Processing Trade of Copper Concentrate

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    <正>On December 31,2008,China’s Ministry of Commerce and General Administration of Cus- toms issued its year-2008 No.121 announce- ment,saying it will adjust the forbidden cate- gory of processing trade,which includes non- ferrous metal products such as copper concen- trate,nickel concentrate,cobalt concentrate, refined copper,nickel and nickel alloy.The above products will be exempt from being for- bidden to process starting from Feb.1,2009.

  2. Renal cortex copper concentration in acute copper poisoning in calves

    Directory of Open Access Journals (Sweden)

    Luis E. Fazzio

    2012-01-01

    Full Text Available The aim of this study was to estimate the diagnostic value of renal cortex copper (Cu concentration in clinical cases of acute copper poisoning (ACP. A total of 97 calves that died due to subcutaneous copper administration were compiled in eleven farms. At least, one necropsy was conducted on each farm and samples for complementary analysis were taken. The degree of autolysis in each necropsy was evaluated. The cases appeared on extensive grazing calf breeding and intensive feedlot farms, in calves of 60 to 200 kg body weight. Mortality varied from 0.86 to 6.96 %, on the farms studied. The first succumbed calf was found on the farms between 6 and 72 hours after the susbcutaneous Cu administration. As discrepancies regarding the reference value arose, the local value (19.9 parts per million was used, confirming the diagnosis of acute copper poisoning in 93% of the analyzed kidney samples. These results confirm the value of analysis of the cortical kidney Cu concentration for the diagnosis of acute copper poisoning.

  3. 10000 Tonnes Of Copper Concentrate Arrived At Nanjing Port

    Institute of Scientific and Technical Information of China (English)

    2016-01-01

    On March 20,a cargo ship loaded with 10000tonnes of copper concentrate docked at Nanjing Port,signaling that the biggest overseas acquisition project of China’s metal industry received concrete result.On that day,the first batch shipment of 11330tonnes of copper concentrate from Peru Las Bambas Copper Mine,a project jointly

  4. Removal Of Volatile Impurities From Copper Concentrates

    Energy Technology Data Exchange (ETDEWEB)

    Winkel, L.; Schuler, A.; Frei, A.; Sturzenegger, M.

    2005-03-01

    To study the removal of volatile impurities from two different copper concentrates they have been heated on a thermo balance to temperatures between 900 and 1500 C. This sample treatment revealed that both concentrates undergo strong weight losses at 500 and 700 C. They were attributed to the removal of sulfur. Elemental analyses of the residues by ICP spectrometry have shown that the thermal treatment efficiently removes the volatile impurities. Already below 900 C most of the arsenic is removed by evaporation, the largest fraction of lead and zinc is removed in the temperature interval of 1300-1500 C. It was observed that quartz in the concentrate leads to the formation of a silicon-enriched phase besides a metal rich sulfide phase. The former is interpreted as an early stage of a silicate slag. Elemental analysis showed that the formation of this distinct slag phase does not hinder the efficient removal of volatile impurities. (author)

  5. Cloud point extraction for the determination of copper in environmental samples by flame atomic absorption spectrometry

    Directory of Open Access Journals (Sweden)

    Ardeshir Shokrollahi

    2008-01-01

    Full Text Available A simple cloud point extraction procedure is presented for the preconcentration of copper in various samples. After complexation by 4-hydroxy-2-mercapto-6-propylpyrimidine (PTU, copper ions are quantitatively extracted into the phase rich in Triton X-114 after centrifugation. Methanol acidified with 0.5 mol L-1 HNO3 was added to the surfactant-rich phase prior to its analysis by flame atomic absorption spectrometry (FAAS. Analytical parameters including concentrations for PTU, Triton X-114 and HNO3, bath temperature, centrifugation rate and time were optimized. The influences of the matrix ions on the recoveries of copper ions were investigated. The detection limits (3SDb/m, n=4 of 1.6 ng mL-1 along with enrichment factors of 30 for Cu were achieved. The proposed procedure was applied to the analysis of environmental samples.

  6. Parameterizing cloud condensation nuclei concentrations during HOPE

    Science.gov (United States)

    Hande, Luke B.; Engler, Christa; Hoose, Corinna; Tegen, Ina

    2016-09-01

    An aerosol model was used to simulate the generation and transport of aerosols over Germany during the HD(CP)2 Observational Prototype Experiment (HOPE) field campaign of 2013. The aerosol number concentrations and size distributions were evaluated against observations, which shows satisfactory agreement in the magnitude and temporal variability of the main aerosol contributors to cloud condensation nuclei (CCN) concentrations. From the modelled aerosol number concentrations, number concentrations of CCN were calculated as a function of vertical velocity using a comprehensive aerosol activation scheme which takes into account the influence of aerosol chemical and physical properties on CCN formation. There is a large amount of spatial variability in aerosol concentrations; however the resulting CCN concentrations vary significantly less over the domain. Temporal variability is large in both aerosols and CCN. A parameterization of the CCN number concentrations is developed for use in models. The technique involves defining a number of best fit functions to capture the dependence of CCN on vertical velocity at different pressure levels. In this way, aerosol chemical and physical properties as well as thermodynamic conditions are taken into account in the new CCN parameterization. A comparison between the parameterization and the CCN estimates from the model data shows excellent agreement. This parameterization may be used in other regions and time periods with a similar aerosol load; furthermore, the technique demonstrated here may be employed in regions dominated by different aerosol species.

  7. Global variability of cloud condensation nuclei concentrations

    Science.gov (United States)

    Makkonen, Risto; Krüger, Olaf

    2017-04-01

    Atmospheric aerosols can influence cloud optical and dynamical processes by acting as cloud condensation nuclei (CCN). Globally, these indirect aerosol effects are significant to the radiative budget as well as a source of high uncertainty in anthropogenic radiative forcing. While historically many global climate models have fixed CCN concentrations to a certain level, most state-of-the-art models calculate aerosol-cloud interactions with sophisticated methodologies based on interactively simulated aerosol size distributions. However, due to scarcity of atmospheric observations simulated global CCN concentrations remain poorly constrained. Here we assess global CCN variability with a climate model, and attribute potential trends during 2000-2010 to changes in emissions and meteorological fields. Here we have used ECHAM5.5-HAM2 with model M7 microphysical aerosol model. The model has been upgraded with a secondary organic aerosol (SOA) scheme including ELVOCs. Dust and sea salt emissions are calculated online, based on wind speed and hydrology. Each experiment is 11 years, analysed after a 6-month spin-up period. The MODIS CCN product (Terra platform) is used to evaluate model performance throughout 2000-2010. While optical remote observation of CCN column includes several deficiencies, the products serves as a proxy for changes during the simulation period. In our analysis we utilize the observed and simulated vertical column integrated CCN concentration, and limit our analysis only over marine regions. Simulated annual CCN column densities reach 2ṡ108 cm-2 near strong source regions in central Africa, Arabian Sea, Bay of Bengal and China sea. The spatial concentration gradient in CCN(0.2%) is steep, and column densities drop to meteorological variability. Most evident pattern of high temporal correlation is found over North Atlantic ocean, extending throughout Europe and up to Gulf of Mexico. All of these regions show a generally decreasing trend throughout the

  8. Denitrifying kinetics and nitrous oxide emission under different copper concentrations.

    Science.gov (United States)

    Wu, Guangxue; Zhai, Xiaofeng; Jiang, Chengai; Guan, Yuntao

    2014-01-01

    Denitrifying activities and nitrous oxide (N2O) emission during denitrification can be affected by copper concentrations. Different denitrifiers were acclimated in sequencing batch reactors with acetate or methanol as the electron donor and nitrate as the electron acceptor. The effect of copper concentrations on the denitrifying activity and N2O emission for the acclimated denitrifiers was examined in batch experiments. Denitrifying activities of the acclimated denitrifiers declined with increasing copper concentrations, and the copper concentration exhibited a higher effect on denitrifiers acclimated with acetate than those acclimated with methanol. Compared with the control without the addition of copper, at the copper concentration of 1 mg/L, the acetate utilization rate reduced by 89% for acetate-acclimated denitrifiers, while the methanol utilization rate only reduced by 15% for methanol-acclimated denitrifiers. Copper also had different effects on N2O emission during denitrification carried out by various types of denitrifiers. For the acetate-acclimated denitrifiers, N2O emission initially increased and then decreased with increasing copper concentrations, while for the methanol-acclimated denitrifiers, N2O emission decreased with increasing copper concentrations.

  9. Satellite retrieval of cloud condensation nuclei concentrations by using clouds as CCN chambers

    OpenAIRE

    2016-01-01

    Quantifying the aerosol/cloud-mediated radiative effect at a global scale requires simultaneous satellite retrievals of cloud condensation nuclei (CCN) concentrations and cloud base updraft velocities (Wb). Hitherto, the inability to do so has been a major cause of high uncertainty regarding anthropogenic aerosol/cloud-mediated radiative forcing. This can be addressed by the emerging capability of estimating CCN and Wb of boundary layer convective clouds from an operational polar orbiting wea...

  10. Copper and zinc concentrations in serum of healthy Greek adults

    Energy Technology Data Exchange (ETDEWEB)

    Kouremenou-Dona, Eleni [A' Hospital of IKA, Athens (Greece); Dona, Artemis [Department of Forensic Medicine and Toxicology, Medical School, University of Athens, M. Asias 75, Goudi, 11527 Athens (Greece)]. E-mail: artedona@med.uoa.gr; Papoutsis, John [Department of Forensic Medicine and Toxicology, Medical School, University of Athens, M. Asias 75, Goudi, 11527 Athens (Greece); Spiliopoulou, Chara [Department of Forensic Medicine and Toxicology, Medical School, University of Athens, M. Asias 75, Goudi, 11527 Athens (Greece)

    2006-04-15

    Serum copper and zinc concentrations of 506 (414 males and 92 females) apparently healthy Greek blood donors aged 18-60 years old were determined by flame atomic absorption spectrometry. The mean copper and zinc concentrations were 115.46 {+-} 23.56 {mu}g/dl and 77.11 {+-} 17.67 {mu}g/dl, respectively. The mean value for copper and zinc in females was higher than in males, although the difference for zinc was smaller than the one observed for copper. When the subjects were divided into various age groups there appeared to be some increase in copper concentration as a function of age, whereas zinc concentration did not change. There were no significant variations in serum copper and zinc concentrations due to place of residence, occupation and socioeconomic status. This study is the first one evaluating the serum status of copper and zinc in healthy Greeks and it has shown that they are at the highest concentration range for copper and the lowest for zinc compared to literature data on copper and zinc levels for various countries.

  11. Liver copper concentration in Wilson's disease: effect of treatment with 'anti-copper' agents.

    Science.gov (United States)

    Gibbs, K; Walshe, J M

    1990-01-01

    Serial copper determinations have been made on the livers of 10 patients with Wilson's disease. Two were studied before and eight after the start of treatment in order to assess the effect, if any, on the concentration of the metal. In two patients who were receiving no therapy and in one in whom it had been discontinued, the level of copper rose. In the latter patient, resumption of treatment then resulted in a fall in the level of copper in the liver. A similar fall was seen in seven patients on continuous therapy. In one patient, a very poor complier, there was a tendency for the liver copper concentration to rise over a 5-year period. All three therapies investigated--penicillamine, trientine and tetrathiomolybdate--when taken regularly, appear to be effective in reducing liver copper levels. Sixty-nine single determinations of liver copper have been plotted against time on treatment. This shows that the copper concentration falls rapidly in the first year. Thereafter, there is no linear relationship between the duration of treatment and liver copper. Poor compliers have a higher liver copper concentration than do good compliers. Determinations made from different portions of the liver showed that in only one of 19 examples was there an overlap between the near normal and the abnormal range. The principal mechanism of action of 'anti-copper' agents in Wilson's disease appears to be the mobilization of copper from the tissues, but a secondary detoxifying action may come into play later.

  12. China Sets the Standards for Copper Concentrates Import

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    <正>In order to safeguard the people’s health and the environment as well as the State interests, China’s related government authorities recently released a notice limiting the import of copper concentrates containing harmful elements. Based on the regulations, the imported copper concentrates (Code No. 2603000010 and 2603000090) will not be allowed to enter into

  13. Concentrations of plasma copper and zinc and blood selenium in ...

    African Journals Online (AJOL)

    Department of Human and Animal Physiology, University of Stellenbosch, Stellenbosch 7600, ... Concentrations of plasma copper and zinc as well as blood selenium were determined in single and twin lambs ... of zinc within the body; notably.

  14. Me-BTABr reagent in cloud point extraction for spectrometric determination of copper in water samples

    OpenAIRE

    Lemos,Valfredo A; Santos, Juracir S.; Baliza,Patrícia X.

    2006-01-01

    A new preconcentration method using cloud point approach is proposed for copper determination. The reagent 2-[2´-(6-methyl-benzothiazolylazo)]-4-bromophenol (Me-BTABr) was used as a complexing agent and Triton X-114 was added as a surfactant. After phase separation, dilution of the surfactant-rich phase with acidified methanol was performed, and the copper content was measured by flame atomic absorption spectrometry. The proposed procedure allowed the determination of copper with detect...

  15. Effect of oral contraceptive progestins on serum copper concentration.

    Science.gov (United States)

    Berg, G; Kohlmeier, L; Brenner, H

    1998-10-01

    High serum copper concentration--a well-known effect of oral contraceptive (OC) use--has been linked to increased mortality from cardiovascular disease. The influence of OCs containing newer progestins has not been investigated, however. This concern was addressed in a 1987-88 cross-sectional epidemiologic study of 610 nonpregnant, nonlactating West German women 18-44 years of age. 195 women (32.1%) were current OC users, but only 152 of these women were able to cite the name of the formulation they were taking. In 70% of cases, the OC contained less than 45 mcg of ethylestradiol (median dose, 32.4 mcg). The most common progestin components were desogestrel (41%) and levonorgestrel (30%). Mean serum copper concentration was higher among users of all types of OCs than among non-users, but this concentration varied more strongly according to the OC's progestin compound than its estrogen content. The greatest increase in serum copper (55% compared with non-users) was recorded in users of OCs containing anti-androgen progestins, followed by desogestrel (46%), norethisterone/lynestrenol (42%), and levonorgestrel (34%). The increase in serum copper was more pronounced in women taking OCs containing 45 mcg or less of ethylestradiol than in users of OCs with a high estrogen dose. In the regression models, the different progestin compounds alone explained 28% of the total variance in serum copper concentration. Further investigation of OC-induced increases in serum copper concentration and their impact on cardiovascular risk are warranted.

  16. A new ultrasonic-assisted cloud-point-extraction procedure for pre-concentration and determination of ultra-trace levels of copper in selected beverages and foods by flame atomic absorption spectrometry.

    Science.gov (United States)

    Altunay, Nail; Gürkan, Ramazan; Orhan, Ulaş

    2015-01-01

    A new ultrasonic-assisted cloud-point-extraction (UA-CPE) method was developed for the pre-concentration of Cu(II) in selected beverage and food samples prior to flame atomic absorption spectrometric (FAAS) analysis. For this purpose, Safranin T was used as an ion-pairing reagent based on charge transfer in the presence of oxalate as the primary chelating agent at pH 10. Non-ionic surfactant, poly(ethyleneglycol-mono-p-nonylphenylether) (PONPE 7.5) was used as an extracting agent in the presence of NH4Cl as the salting out agent. The variables affecting UA-CPE efficiency were optimised in detail. The linear range for Cu(II) at pH 10 was 0.02-70 µg l(-)(1) with a very low detection limit of 6.10 ng l(-)(1), while the linear range for Cu(I) at pH 8.5 was 0.08-125 µg l(-)(1) with a detection limit of 24.4 ng l(-)(1). The relative standard deviation (RSD %) was in the range of 2.15-4.80% (n = 5). The method was successfully applied to the quantification of Cu(II), Cu(I) and total Cu in selected beverage and food samples. The accuracy of the developed method was demonstrated by the analysis of two standard reference materials (SRMs) as well as recoveries of spiked samples.

  17. Investigation of analytical performance for rapidly synergistic cloud point extraction of trace amounts of copper combined with spectrophotometric determination

    Science.gov (United States)

    Wen, Xiaodong; Ye, Liqing; Deng, Qingwen; Peng, Li

    2011-12-01

    In this work, an improved preconcentration method named as rapidly synergistic cloud point extraction (RS-CPE) was established for copper preconcentration and determination. Non-ionic surfactant Triton X-100 (TX-100) was used as extractant. Octanol worked as cloud point revulsant and synergic reagent, which successfully decreased the cloud point temperature (CPT) of TX-100 to realize the room temperature (about 20 °C) CPE without heating. The established RS-CPE pretreatment was simple, rapid and effective. Compared with traditional CPE (about 40 min for heating, incubation and cooling), the extraction time of the proposed method was very short (1 min). The improved extraction technique RS-CPE was combined with traditional spectrophotometer to improve the analytical performance and expand the application of spectrophotometric determination. The influence factors relevant to RS-CPE, such as concentrations of TX-100 and octanol, concentration of chelating agent, pH, conditions of phase separation, salt effect, environmental temperature and instrumental conditions, were studied in detail. Under the optimal conditions, the limit of detection (LOD) for copper was 0.4 μg L -1, with sensitivity enhancement factor (EF) of 18. The proposed method was applied to the determination of trace copper in real samples and certified samples with satisfactory analytical results.

  18. Satellite retrieval of cloud condensation nuclei concentrations by using clouds as CCN chambers

    Science.gov (United States)

    Rosenfeld, Daniel; Zheng, Youtong; Hashimshoni, Eyal; Pöhlker, Mira L.; Jefferson, Anne; Pöhlker, Christopher; Yu, Xing; Zhu, Yannian; Liu, Guihua; Yue, Zhiguo; Fischman, Baruch; Li, Zhanqing; Giguzin, David; Goren, Tom; Artaxo, Paulo; Pöschl, Ulrich

    2016-01-01

    Quantifying the aerosol/cloud-mediated radiative effect at a global scale requires simultaneous satellite retrievals of cloud condensation nuclei (CCN) concentrations and cloud base updraft velocities (Wb). Hitherto, the inability to do so has been a major cause of high uncertainty regarding anthropogenic aerosol/cloud-mediated radiative forcing. This can be addressed by the emerging capability of estimating CCN and Wb of boundary layer convective clouds from an operational polar orbiting weather satellite. Our methodology uses such clouds as an effective analog for CCN chambers. The cloud base supersaturation (S) is determined by Wb and the satellite-retrieved cloud base drop concentrations (Ndb), which is the same as CCN(S). Validation against ground-based CCN instruments at Oklahoma, at Manaus, and onboard a ship in the northeast Pacific showed a retrieval accuracy of ±25% to ±30% for individual satellite overpasses. The methodology is presently limited to boundary layer not raining convective clouds of at least 1 km depth that are not obscured by upper layer clouds, including semitransparent cirrus. The limitation for small solar backscattering angles of <25° restricts the satellite coverage to ∼25% of the world area in a single day. PMID:26944081

  19. Effect of oral contraceptive progestins on serum copper concentration

    DEFF Research Database (Denmark)

    Berg, Gabriele; Kohlmeier, L; Brenner, H

    1998-01-01

    using oral contraceptives containing antiandrogen progestins (55%; 95% CI: 37-76%), followed by desogestrel (46%; 95% CI: 36-56%), norethisteron/lynestrenol (42%; 95% CI: 29-57%), and levonorgestrel (34%; 95% CI: 24-45%). CONCLUSION: While elevated serum copper concentration was found in users of all...

  20. Molybdenum removal from copper ore concentrate by sodium hypochlorite leaching

    Institute of Scientific and Technical Information of China (English)

    Liu Youcai; Zhong Hong; Cao Zhanfang

    2011-01-01

    The removal of molybdenum from a copper ore concentrate by sodium hypochlorite leaching was investigated. The results show that leaching time, liquid to solid ratio, leaching ternperature, agitation speed, and sodium hypochlorite and sodium hydroxide concentrations all have a significant effect on the removal of molybdenum. The optimum process operating parameters were found to be: time, 4 h: sodium hydroxide concentration, 10%; sodium hypochlorite concentration, 8%; liquid to solid ratio, 10:1; temperature, 50℃; and,agitation speed, 500 r/min. Under these conditions the extraction of molybdenum is greater than 99.9% and the extraction of copper is less than 0.01%. A shrinking particle model could be used to describe the leaching process. The apparent activation energy of the dissolution reaction was found to be approximately 8.8 kJ/mol.

  1. Erythrocyte copper chaperone for superoxide dismutase and superoxide dismutase as biomarkers for hepatic copper concentrations in Labrador retrievers

    NARCIS (Netherlands)

    Dirksen, K; Roelen, Y S; van Wolferen, M E; Kruitwagen, H S; Penning, L C; Burgener, I A; Spee, B; Fieten, H

    2016-01-01

    Hereditary hepatic copper accumulation in Labrador retrievers leads to hepatitis with fibrosis and eventually cirrhosis. The development of a non-invasive blood-based biomarker for copper status in dogs could be helpful in identifying dogs at risk and to monitor copper concentrations during

  2. Copper and zinc concentrations in Nigerian women with breast cancer.

    Science.gov (United States)

    Ajayi, G O

    2011-01-01

    Trace elements are accepted to be involved directly or indirectly in the process of cancer formation. In this study, serum selenium, copper and zinc were measured in three groups of patients using atomic absorption spectrometer. A total of 29 Nigerian women were included: group I consisted of nine age-matched healthy controls without breast problems; group 2 included nine women with benign breast disease; and group 3 was comprised of women with breast cancer. The serum concentration of copper (Cu) was significantly higher in patients with cancer when compared to the control group (1.43 +/- 0.31 microg/ml vs 0.91 +/- 0.18 microg/ul/0.94 +/- 0.10 microg/ml). The zinc (Zn) concentration was significantly lower in the breast cancer group than in the other two groups (0.74 +/- 0.21 microg/ml vs 1.14 +/- 0.31 ug/ml/1.11 +/- 0.29 microg/ml; p copper and zinc in serum of patients with breast cancer, which may indicate abnormal copper and zinc metabolism in Nigerian females with breast cancer.

  3. A revised estimate of copper emissions from road transport in UNECE-Europe and its impact on predicted copper concentrations

    NARCIS (Netherlands)

    Denier van der Gon, H.A.C.; Hulskotte, J.H.J.; Visschedijk, A.J.H.; Schaap, M.

    2007-01-01

    Comparisons of measured and model-predicted atmospheric copper concentrations show a severe underestimation of the observed concentrations by the models. This underestimation may be (partly) due to underestimated emissions of copper to air. Since the phase out of asbestos brake lining material, the

  4. Effect of Gestation and Maternal Copper on the Fetal Fluids and Tissues Copper Concentrations in Sheep

    Directory of Open Access Journals (Sweden)

    Abd E. Hefnawy

    2011-01-01

    Full Text Available Problem statement: Samples of allantoic, amniotic fluid, fetal liver, kidney, maternal plasma and liver were collected from 30 ewes and classified into either early or late gestation and copper concentrations were measured. Approach: The Cu concentrations in the maternal plasma, allantoic, amniotic fluid, fetal liver and kidney increased significantly (pResults: Significant positive relationships were recorded between age of the fetus and Cu concentrations in the allantoic and amniotic fluid (r = 0.71-0.83, pConclusion: A significant negative correlation was recorded between the Cu concentrations in the maternal liver and fetal age (r = -0.74, p<0.01. Strong fetal-maternal relationships in Cu concentration were evident throughout the gestational period and dams seem to sacrifice Cu levels in order to maintain that in the fetus. Cu concentrations in the amniotic and allantoic fluids could be used as a possible indicator of the Cu status of the fetus throughout gestation.

  5. Cloud-point extraction, preconcentration and spectrophotometric determination of trace quantities of copper in food, water and biological samples.

    Science.gov (United States)

    Gouda, Ayman A; Amin, Alaa S

    2014-01-01

    A new, simple and sensitive cloud point extraction procedure was presented for the preconcentration and determination of copper(II) ion in food, water and biological samples. The analyte was complexed with a new synthesized reagent, 2-amino-4-(m-tolylazo)pyridine-3-ol (ATAP) as a new complexing agent and Triton X-114 as the surfactant. After centrifugation, dilution of the surfactant-rich phase with 0.4 mL of ethanol acidified with 1.0M HNO3 was performed after phase separation, and the copper contents were measured by spectrophotometry at λmax 608 nm. The influence of analytical parameters including concentration of complexing agent, Triton X-114, pH, equilibration temperature and time, centrifuge rate and time were optimized. The analytical characteristics of the method (e.g. linear range, molar absorptivity, Sandell sensitivity, optimum Ringbom concentration ranges limits of detection and quantification, preconcentration factor, and improvement factors) were obtained. Linearity was obeyed in the range of 4.0-115 ng mL(-1) of Cu(II) ion. The detection and quantification limits of the method were 1.20 and 3.94 ng mL(-1) of Cu(II) ion, respectively. The interference effect of some anions and cations was also tested. The method was applied for determination of copper in food, water and biological samples.

  6. The Copper concentration variation to physical properties of high copper amalgam alloy

    Directory of Open Access Journals (Sweden)

    Aminatun Aminatun

    2006-09-01

    Full Text Available The function of copper (Cu inside amalgam is to increase hardness and impact force and to decrease thermal expansion coefficient. In general, amalgam which is used in dentistry and available in the market is contain Cu 22%, while the maximum Cu concentration is 30%. It is necessary to determine the concentration Cu does generate the best physical properties to be used as dental restorative agent. Amalgam is made by mixing blended-metal Ag-Sn-Cu (with Cu concentration of 13%, 21%, 22%, and 29% and Hg, stirred manually in a bowl for 15 minutes,leave it in temperature 27°C for 24 hours to become hardened. The result of X-Ray Diffractometer (XRD, analyzed by Rietveld method and Rietica program, shows amalgam with Cu 29% concentration for Cu3Sn compound density is 31.790 sma/Å3, for Ag2Hg3 compound is 41.733 sma/ Å3, a Cu3Sn relative weight percentage of 43.23%, Ag2Hg3 of 54.54%, Cu 7Hg6 of 2.23% and hardness of Cu 29% is 90.700 ± 0.005 kgf/mm2. These numbers are the highest values on Cu 29% concentrations compared to other copper concentration variants. Whereas amalgam thermal expansion coefficient on Cu 29% is (2.17 ± 0.9110-3 mm/°C is the lowest value compared to other Cu concentration. The conclution is that adding Cu concentration into amalgam will increase density value, Cu3Sn relative weight percentage, hardness level and will decrease amalgam thermal expansion coefficient. Amalgam 29% Cu concentration has better physical properties compared to amalgam Cu 22% concentration.

  7. Relative bioavailability of copper in tribasic copper chloride to copper in copper sulfate for laying hens based on egg yolk and feather copper concentrations.

    Science.gov (United States)

    Kim, J W; Kim, J H; Shin, J E; Kil, D Y

    2016-07-01

    This experiment was conducted to determine the relative bioavailability (RBV) of Cu in tribasic copper chloride (TBCC) to Cu in copper sulfate (monohydrate form; CuSO4·H2O) for layer diets based on egg yolk and feather Cu concentrations. A total of 252, 72-wk-old Hy-Line Brown laying hens were allotted to 1 of 7 treatments with 6 replicates consisting of 6 hens per replicate in a completely randomized design. Hens were fed corn-soybean meal-based basal diets supplemented with 0 (basal), 100, 200, or 300 mg/kg Cu from CuSO4 or TBCC for 4 wk. Results indicated that egg production, egg weight, and egg mass were not affected by dietary treatments. However, increasing inclusion levels of Cu in diets from CuSO4 decreased (P hens fed diets containing CuSO4 than for hens fed diets containing TBCC. The values for the RBV of Cu in TBCC to Cu in CuSO4 based on log10 transformed egg yolk and feather Cu concentrations were 107.4% and 69.5%, respectively. These values for the RBV of Cu in TBCC did not differ from Cu in CuSO4 (100%). The RBV measured in egg yolk did not differ from the RBV measured in feather. In conclusion, the RBV of Cu in TBCC to Cu in CuSO4 can be determined using Cu concentrations of egg yolk and feathers although the values depend largely on target tissues of laying hens. For a practical application, however, the RBV value of Cu in TBCC to Cu in CuSO4 could be 88.5% when the RBV values determined using egg yolk and feather Cu concentrations were averaged.

  8. Thermal Decomposition of Copper Ore Concentrate and Polyethylene Composites

    Science.gov (United States)

    Szyszka, Danuta; Wieckowska, Jadwiga

    2016-10-01

    Thermal analyses (TGA and DTA) of the composite, comprised of 10% polyethylene (PE) scrap and 90% copper ore concentrate, enabled determination of the temperature range and decomposition degree of the organic matters in argon atmosphere. Products of pyrolysis were qualitatively and quantitatively determined. The results were compared to those obtained for products of pyrolysis of the composite in air. Products of pyrolysis were identified by means of the gas chromatography (GC) method alone or supported with results of mass spectrometry analyses (GC-MS).

  9. Influence of atmospheric ice nucleus concentrations on cold cloud radiant properties and cold cloud reflectivity changes in past years

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    PAL satellite dataset which have long temporal span is used in the study. Relationship between cold cloud reflectivity and aerosol concentration in Beijing is analyzed as an example. From analysis, cold cloud reflectivity is found to be well correlated with aerosol optical depth. Meanwhile, it is retro-correlated with surface visibility. The results mean that cold cloud reflectivity is possibly influenced by ice nucleus concentration changes. Analysis about cold cloud reflectivity changes during the period 1982-1999 in Beijing shows that reflectivity increases in earlier years and decreases in later years. The data of cold cloud reflectivity in China show that reflectivity in some regions has changed. For the reason that cold cloud is very important in global climate system, those changes of cold cloud reflectivity can lead to climate changes finally.

  10. Serum concentration of copper, zinc, iron, and cobalt and the copper/zinc ratio in horses with equine herpesvirus-1.

    Science.gov (United States)

    Yörük, Ibrahim; Deger, Yeter; Mert, Handan; Mert, Nihat; Ataseven, Veysel

    2007-07-01

    The serum concentrations of copper, zinc, iron, and cobalt and copper/zinc ratio were investigated in horses infected with equine herpesvirus-1 (EHV-1). Nine horses were naturally infected with the virus and nine healthy horses served as controls. The concentrations of copper, zinc, iron, and cobalt were determined spectrophotometrically in the blood serum of all horses. The results were (expressed in micrograms per deciliters) copper 2.80 +/- 0.34 vs 1.12 +/- 0.44, zinc 3.05 +/- 0.18 vs 0.83 +/- 0.06, iron 2.76 +/- 0.17 vs 3.71 +/- 0.69, cobalt 0.19 +/- 0.37 vs 0.22 +/- 0.45, and copper/zinc ratio 0.72 +/- 0.38 vs 1.41 +/- 0.36 for control vs infected group, respectively. In conclusion, copper and zinc concentrations of the infected group were lower than the control group (p copper/zinc ratio of the infected group were higher than the control group (p cobalt concentration was not found to be statistically different between two groups. It might be emphasized that copper/zinc ratio was significantly affected by the EHV-1 infection, so it could be taken into consideration during the course of infection.

  11. Temperature and Copper Concentration Effects on the Formation of Graphene-Encapsulated Copper Nanoparticles from Kraft Lignin

    Directory of Open Access Journals (Sweden)

    Weiqi Leng

    2017-06-01

    Full Text Available The effects of temperature and copper catalyst concentration on the formation of graphene-encapsulated copper nanoparticles (GECNs were investigated by means of X-ray diffraction, Fourier transform infrared spectroscopy-attenuated total reflectance, and transmission electron microscopy. Results showed that higher amounts of copper atoms facilitated the growth of more graphene islands and formed smaller size GECNs. A copper catalyst facilitated the decomposition of lignin at the lowest temperature studied (600 °C. Increasing the temperature up to 1000 °C retarded the degradation process, while assisting the reconfiguration of the defective sites of the graphene layers, thus producing higher-quality GECNs.

  12. Cloud point extraction and flame atomic absorption spectrometry combination for copper(II) ion in environmental and biological samples

    Energy Technology Data Exchange (ETDEWEB)

    Shokrollahi, Ardeshir [Chemistry Department, Yasouj University, Yasouj 75914-353 (Iran, Islamic Republic of)], E-mail: ashokrollahi@mail.yu.ac.ir; Ghaedi, Mehrorang [Chemistry Department, Yasouj University, Yasouj 75914-353 (Iran, Islamic Republic of)], E-mail: m_ghaedi@mail.yu.ac.ir; Hossaini, Omid; Khanjari, Narges [Chemistry Department, Yasouj University, Yasouj 75914-353 (Iran, Islamic Republic of); Soylak, Mustafa [Chemistry Department, University of Erciyes, 38039 Kayseri (Turkey)

    2008-12-30

    A cloud point extraction procedure was presented for the preconcentration of copper(II) ion in various samples. After complexation by 4-(phenyl diazenyl) benzene-1,3-diamine (PDBDM) (chrysoidine), copper(II) ions were quantitatively recovered in Triton X-114 after centrifugation. 0.5 ml of methanol acidified with 1.0 mol L{sup -1} HNO{sub 3} was added to the surfactant-rich phase prior to its analysis by flame atomic absorption spectrometry (FAAS). The influence of analytical parameters including ligand, Triton X-114 and HNO{sub 3} concentrations, bath temperature, heating time, centrifuge rate and time were optimized. The effect of the matrix ions on the recovery of copper(II) ions was investigated. The detection limit (3S.D.{sub b}/m, n = 10) of 0.6 ng mL{sup -1} along with preconcentration factor of 30 and enrichment factor of 41.1 with R.S.D. of 1.0% for Cu was achieved. The proposed procedure was applied to the analysis of various environmental and biological samples.

  13. Global impact of mineral dust on cloud droplet number concentration

    Science.gov (United States)

    Karydis, Vlassis A.; Tsimpidi, Alexandra P.; Bacer, Sara; Pozzer, Andrea; Nenes, Athanasios; Lelieveld, Jos

    2017-05-01

    The importance of wind-blown mineral dust for cloud droplet formation is studied by considering (i) the adsorption of water on the surface of insoluble particles, (ii) particle coating by soluble material (atmospheric aging) which augments cloud condensation nuclei (CCN) activity, and (iii) the effect of dust on inorganic aerosol concentrations through thermodynamic interactions with mineral cations. The ECHAM5/MESSy Atmospheric Chemistry (EMAC) model is used to simulate the composition of global atmospheric aerosol, while the ISORROPIA-II thermodynamic equilibrium model treats the interactions of K+-Ca2+-Mg2+-NH4+-Na+-SO42--NO3--Cl--H2O aerosol with gas-phase inorganic constituents. Dust is considered a mixture of inert material with reactive minerals and its emissions are calculated online by taking into account the soil particle size distribution and chemical composition of different deserts worldwide. The impact of dust on droplet formation is treated through the unified dust activation parameterization that considers the inherent hydrophilicity from adsorption and acquired hygroscopicity from soluble salts during aging. Our simulations suggest that the presence of dust increases cloud droplet number concentration (CDNC) over major deserts (e.g., up to 20 % over the Sahara and the Taklimakan desert) and decreases CDNC over polluted areas (e.g., up to 10 % over southern Europe and 20 % over northeastern Asia). This leads to a global net decrease in CDNC by 11 %. The adsorption activation of insoluble aerosols and the mineral dust chemistry are shown to be equally important for the cloud droplet formation over the main deserts; for example, these effects increase CDNC by 20 % over the Sahara. Remote from deserts the application of adsorption theory is critically important since the increased water uptake by the large aged dust particles (i.e., due to the added hydrophilicity by the soluble coating) reduce the maximum supersaturation and thus cloud droplet

  14. Sensitivity of cloud albedo to aerosol concentration and spectral dispersion of cloud droplet size distribution

    Energy Technology Data Exchange (ETDEWEB)

    Iorga, G. [Faculty of Chemistry, University of Bucharest, Bucharest (Romania)]. E-mail: giorga@gw-chimie.math.unibuc.ro; Stefan, S. [Faculty of Physics, University of Bucharest, Bucharest (Romania)

    2007-07-15

    Both the enhancement of the aerosol number concentration and the relative dispersion of the cloud droplet size distribution (spectral dispersion) on a regional scale can modify the cloud reflectivity. This work is focused on the role that pre-cloud aerosol plays in cloud reflectivity. Log-normal aerosol size distributions were used to describe two aerosol types: marine and rural. The number of aerosols that activate to droplets was obtained based on Abdul-Razzak and Ghan's (2000) activation parameterization. The cloud albedo taking into account the spectral dispersion effect in the parameterization of cloud effective radius and in the scattering asymmetry factor has been estimated. Two different scaling factors to account for dispersion were used. The sensitivity of cloud albedo to spectral dispersion-cloud droplet number concentration relationship in connection to the changes in liquid water content (LWC), and the cloud droplet effective radius has been also investigated. We obtained higher values of effective radius when dispersion is taken into account, with respect to the base case (without considering dispersion). The inferred absolute differences in effective radius values between calculations with each of the scaling factors are below 0.8 {mu}m as LWC ranges between 0.1 and 1.0 g m-3. The optical depth decreased by up to 14% (marine), and up to 29% (continental) when dispersion is considered in both effective radius and asymmetry factor ({beta}LDR scaling factor). Correspondingly, the relative change in cloud albedo is up to 6% (marine) and up to 11% (continental) clouds. For continental clouds, the calculated effective radius when dispersion is considered fits well within the measured range of effective radius in SCAR-B project. The calculated cloud albedo when dispersion is considered shows better agreement with the estimated cloud albedo from measured effective radius in SCAR-B project than the cloud albedo calculated without dispersion. In cleaner

  15. Development of a cloud-point extraction method for copper and nickel determination in food samples

    Energy Technology Data Exchange (ETDEWEB)

    Azevedo Lemos, Valfredo [Nucleo de Quimica Analitica da Bahia (NQA), Laboratorio de Quimica Analitica (LQA), Universidade Estadual do Sudoeste da Bahia, Campus de Jequie, 45206-190 Jequie, BA (Brazil)], E-mail: vlemos@uesb.br; Selis Santos, Moacy; Teixeira David, Graciete; Vasconcelos Maciel, Mardson; Almeida Bezerra, Marcos de [Nucleo de Quimica Analitica da Bahia (NQA), Laboratorio de Quimica Analitica (LQA), Universidade Estadual do Sudoeste da Bahia, Campus de Jequie, 45206-190 Jequie, BA (Brazil)

    2008-11-30

    A new, simple and versatile cloud-point extraction (CPE) methodology has been developed for the separation and preconcentration of copper and nickel. The metals in the initial aqueous solution were complexed with 2-(2'-benzothiazolylazo)-5-(N,N-diethyl)aminophenol (BDAP) and Triton X-114 was added as surfactant. Dilution of the surfactant-rich phase with acidified methanol was performed after phase separation, and the copper and nickel contents were measured by flame atomic absorption spectrometry. The variables affecting the cloud-point extraction were optimized using a Box-Behnken design. Under the optimum experimental conditions, enrichment factors of 29 and 25 were achieved for copper and nickel, respectively. The accuracy of the method was evaluated and confirmed by analysis of the followings certified reference materials: Apple Leaves, Spinach Leaves and Tomato Leaves. The limits of detection expressed to solid sample analysis were 0.1 {mu}g g{sup -1} (Cu) and 0.4 {mu}g g{sup -1} (Ni). The precision for 10 replicate measurements of 75 {mu}g L{sup -1} Cu or Ni was 6.4 and 1.0, respectively. The method has been successfully applied to the analysis of food samples.

  16. Estimating seasonal variations in cloud droplet number concentration over the boreal forest from satellite observations

    Directory of Open Access Journals (Sweden)

    R. H. H. Janssen

    2011-08-01

    Full Text Available Seasonal variations in cloud droplet number concentration (NCD in low-level stratiform clouds over the boreal forest are estimated from MODIS observations of cloud optical and microphysical properties, using a sub-adiabatic cloud model to interpret vertical profiles of cloud properties. An uncertainty analysis of the cloud model is included to reveal the main sensitivities of the cloud model. We compared the seasonal cycle in NCD, obtained using 9 yr of satellite data, to surface concentrations of potential cloud activating aerosols, measured at the SMEAR II station at Hyytiälä in Finland. The results show that NCD and cloud condensation nuclei (CCN concentrations have no clear correlation at seasonal time scale. The fraction of aerosols that actually activate as cloud droplet decreases sharply with increasing aerosol concentrations. Furthermore, information on the stability of the atmosphere shows that low NCD is linked to stable atmospheric conditions. Combining these findings leads to the conclusion that cloud droplet activation for the studied clouds over the boreal forest is limited by convection. Our results suggest that it is important to take the strength of convection into account when studying the influence of aerosols from the boreal forest on cloud formation, although they do not rule out the possibility that aerosols from the boreal forest affect other types of clouds with a closer coupling to the surface.

  17. Comparison of Plasma Copper Concentrations in Patients with Brucellosis and Control Group

    Directory of Open Access Journals (Sweden)

    A.R. Mobaien

    2008-07-01

    Full Text Available Introduction & Objective : There are some reports about influence of the rare nutrients such as copper and zinc on immune system. Serum concentrations of copper alter in patients with brucellosis. Brucellosis is a common and endemic disease and a health problem in Iran. We compared serum concentrations of copper in patients with brucellosis and healthy individuals.Materials & Methods: In a cross sectional study, serum concentrations of copper was measured in patients with brucellosis and control group. Eighty six subjects were enrolled in the study, including 43 patients with brucellosis (34 men and 9 women and 43 healthy individuals. Serum concentrations of copper was measured by automatic absorptive spectrophotometer in patients with brucellosis and compared with control group. We employed a non parametrical test, kolmogrov – smirnov, to determine if data distribution was normal or not. Results: Mean age of patients with brucellosis was 40.1415.10 years with the range of 14-60 years. The most frequent symptoms were arthralgia (86%. Serum concentrations of copper in patients with brucellosis were significantly higher than healthy subjects (160.8454.61, 101.7427.37 g/dl respectively, p<0.001.Conclusion: Serum concentrations of copper in patients with brucellosis showed significant alterations in comparison with healthy subjects. So, we recommend using serum copper concentrations in patients with brucellosis as a marker in brucellosis diagnosis. Also we recommend another study for detection of serum copper concentrations before and during treatment.

  18. Influences of Ice Crystal Number Concentrations and Habits on Arctic Mixed-Phase Cloud Dynamics

    Science.gov (United States)

    Komurcu, Muge

    2016-09-01

    Mixed-phase clouds are frequently present in the Arctic atmosphere, and strongly affect the surface energy budget. In this study, the influences of ice crystal number concentrations and crystal growth habits on the Arctic mixed-phase cloud microphysics and dynamics are investigated for internally and externally driven cloud systems using an eddy-resolving model. Separate simulations are performed with increasing ice concentrations and different ice crystal habits. It is found that the habit influence on cloud microphysics and dynamics is as pronounced as increasing the ice crystal concentrations for internally driven clouds and more dominant for externally driven clouds. Habit influence can lead to a 10 % reduction in surface incident longwave radiation flux. Sensitivity tests are performed to identify the interactions between processes affecting cloud dynamics that allow for persistent clouds (i.e., the radiative cooling at cloud top, ice precipitation stabilization at cloud-base). When cloud-base stabilization influences of ice precipitation are weak, cloud dynamics is more sensitive to radiative cooling. Additional sensitivity simulations are done with increasing surface latent and sensible heat fluxes to identify the influences of external forcing on cloud dynamics. It is found that the magnitude of cloud circulations for an externally driven cloud system with strong precipitation and weak surface fluxes is similar to a weakly precipitating, optically thick, internally driven cloud. For cloud systems with intense ice precipitation obtained through either increasing ice crystal concentrations or assuming ice crystal shapes that grow rapidly and fall fast, the cloud layer may collapse despite the moistening effect of surface fluxes.

  19. Numerical Analysis of Effects of Atmospheric Ice Nuclei Concentrations on Radiant Properties of Cold Clouds

    Institute of Scientific and Technical Information of China (English)

    LI Juan; MAO Jietai; HU Zhijin; YOU Laiguang; ZHANG Qiang

    2005-01-01

    Numerical simulations of 18 precipitation days from June to September in 1996 with the 3D convective cloud model of CAMS (Chinese Academy of Meteorological Sciences, Version 2000) were conducted. In these simulations, the concentration of IN (ice nuclei) was assumed to increase by 5 times. The results show that when IN concentrations increase, the amounts of precipitation decrease, cloud tops heighten and the areas of cloud tops increase in 80 percent simulated clouds. Moreover, in 95 percent simulated clouds, the sizes of ice crystals in clouds decrease and quantities increase. These results mean that the physical properties of clouds will change when IN concentration increases. The radiant properties of clouds and climate may also change directly and indirectly.

  20. Evaluation of long-term surface-retrieved cloud droplet number concentration with in situ aircraft observations: ARM Cloud Droplet Number Concentration

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Kyo-Sun Sunny [Pacific Northwest National Laboratory, Richland Washington USA; Riihimaki, Laura [Pacific Northwest National Laboratory, Richland Washington USA; Comstock, Jennifer M. [Pacific Northwest National Laboratory, Richland Washington USA; Schmid, Beat [Pacific Northwest National Laboratory, Richland Washington USA; Sivaraman, Chitra [Pacific Northwest National Laboratory, Richland Washington USA; Shi, Yan [Pacific Northwest National Laboratory, Richland Washington USA; McFarquhar, Greg M. [Department of Atmospheric Sciences, University of Illinois at Urbana-Champaign, Urbana Illinois USA

    2016-03-06

    A new cloud-droplet number concentration (NDROP) value added product (VAP) has been produced at the Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) site for the 13 years from January 1998 to January 2011. The retrieval is based on surface radiometer measurements of cloud optical depth from the multi-filter rotating shadow-band radiometer (MFRSR) and liquid water path from the microwave radiometer (MWR). It is only applicable for single-layered warm clouds. Validation with in situ aircraft measurements during the extended-term aircraft field campaign, Routine ARM Aerial Facility (AAF) CLOWD Optical Radiative Observations (RACORO), shows that the NDROP VAP robustly reproduces the primary mode of the in situ measured probability density function (PDF), but produces a too wide distribution, primarily caused by frequent high cloud-droplet number concentration. Our analysis shows that the error in the MWR retrievals at low liquid water paths is one possible reason for this deficiency. Modification through the diagnosed liquid water path from the coordinate solution improves not only the PDF of the NDROP VAP but also the relationship between the cloud-droplet number concentration and cloud-droplet effective radius. Consideration of entrainment effects rather than assuming an adiabatic cloud improves the values of the NDROP retrieval by reducing the magnitude of cloud-droplet number concentration. Aircraft measurements and retrieval comparisons suggest that retrieving the vertical distribution of cloud-droplet number concentration and effective radius is feasible with an improvement of the parameter representing the mixing effects between environment and clouds and with a better understanding of the effect of mixing degree on cloud properties.

  1. Determination of Ultratrace Amounts of Copper(Ⅱ) in Water Samples by Electrothermal Atomic Absorption Spectrometry After Cloud Point Extraction

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A novel approach was developed for the determination of ultratrace amounts of copper in water samples by using electrothermal atomic absorption spectrometry (ETAAS) after cloud point extraction (CPE). 1-( 2-Pyridylazo)-2-naphthol was used as the chelating reagent and Triton X-114 as the micellar-forming surfactant. CPE was conducted in a pH 8.0 medium at 40 ℃ for 10 min. After the separation of the phases by centrifugation, the surfactant-rich phase was diluted with 1 mL of a methanol solution of 0. 1 mol/L HNO3. Then 20 μL of the diluted surfactant-rich phase was injected into the graphite furnace for atomization in the absence of any matrix modifier. Various experimental conditions that affect the extraction and atomization processes were optimized. A detection limit of 5 ng/L was obtained after preconcentration. The linear dynamic range of the copper mass concentration was found to be 0-2.0ng/mL, and the relative standard deviation was found to be less than 3.1% for a sample containing 1.0 ng/mL Cu(Ⅱ). This developed method was successfully applied to the determination of ultratrace amounts of Cu in drinking water, tap water, and seawater samples.

  2. Evaluation of planarization performance for a novel alkaline copper slurry under a low abrasive concentration

    Science.gov (United States)

    Mengting, Jiang; Yuling, Liu; Haobo, Yuan; Guodong, Chen; Weijuan, Liu

    2014-11-01

    A novel alkaline copper slurry that possesses a relatively high planarization performance is investigated under a low abrasive concentration. Based on the action mechanism of CMP, the feasibility of using one type of slurry in copper bulk elimination process and residual copper elimination process, with different process parameters, was analyzed. In addition, we investigated the regular change of abrasive concentration effect on copper and tantalum removal rate and within wafer non-uniformity (WIWNU) in CMP process. When the abrasive concentration is 3 wt%, in bulk elimination process, the copper removal rate achieves 6125 Å/min, while WIWNU is 3.5%, simultaneously. In residual copper elimination process, the copper removal rate is approximately 2700 Å/min, while WIWNU is 2.8%. Nevertheless, the tantalum removal rate is 0 Å/min, which indicates that barrier layer isn't eliminated in residual copper elimination process. The planarization experimental results show that an excellent planarization performance is obtained with a relatively high copper removal rate in bulk elimination process. Meanwhile, after residual copper elimination process, the dishing value increased inconspicuously, in a controllable range, and the wafer surface roughness is only 0.326 nm (sq slurry show almost no major differences with two kinds of commercial acid slurries after polishing. All experimental results are conducive to research and improvement of alkaline slurry in the future.

  3. Ningbo is Becoming a New Concentration Ground of Copper Cathode

    Institute of Scientific and Technical Information of China (English)

    2014-01-01

    <正>This year witnessed significant slowdown in transactions in China’s copper market;however Ningbo’s copper cathode transaction bucked the trend to record profit.The reporter yesterday learned from the Ningbo Commodity Exchange that in the first quarter,this commodity exchange fulfilled delivery of16700 tonnes,recording a robust growth of

  4. Cloud point extraction for the determination of copper, nickel and cobalt ions in environmental samples by flame atomic absorption spectrometry.

    Science.gov (United States)

    Ghaedi, M; Shokrollahi, A; Ahmadi, F; Rajabi, H R; Soylak, M

    2008-02-11

    A cloud point extraction procedure was presented for the preconcentration of copper, nickel and cobalt ions in various samples. After complexation with methyl-2-pyridylketone oxime (MPKO) in basic medium, analyte ions are quantitatively extracted to the phase rich in Triton X-114 following centrifugation. 1.0 mol L(-1) HNO(3) nitric acid in methanol was added to the surfactant-rich phase prior to its analysis by flame atomic absorption spectrometry (FAAS). The adopted concentrations for MPKO, Triton X-114 and HNO(3), bath temperature, centrifuge rate and time were optimized. Detection limits (3 SDb/m) of 1.6, 2.1 and 1.9 ng mL(-1) for Cu(2+), Co(2+) and Ni(2+) along with preconcentration factors of 30 and for these ions and enrichment factor of 65, 58 and 67 for Cu(2+), Ni(2+) and Co(2+), respectively. The high efficiency of cloud point extraction to carry out the determination of analytes in complex matrices was demonstrated. The proposed procedure was applied to the analysis of biological, natural and wastewater, soil and blood samples.

  5. Cloud point extraction for the determination of copper, nickel and cobalt ions in environmental samples by flame atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Ghaedi, M. [Chemistry Department, University of Yasouj, Yasouj 75914-353 (Iran, Islamic Republic of)], E-mail: m_ghaedi@mail.yu.ac.ir; Shokrollahi, A.; Ahmadi, F.; Rajabi, H.R. [Chemistry Department, University of Yasouj, Yasouj 75914-353 (Iran, Islamic Republic of); Soylak, M. [Chemistry Department, University of Erciyes, 38039 Kayseri (Turkey)

    2008-02-11

    A cloud point extraction procedure was presented for the preconcentration of copper, nickel and cobalt ions in various samples. After complexation with methyl-2-pyridylketone oxime (MPKO) in basic medium, analyte ions are quantitatively extracted to the phase rich in Triton X-114 following centrifugation. 1.0 mol L{sup -1} HNO{sub 3} nitric acid in methanol was added to the surfactant-rich phase prior to its analysis by flame atomic absorption spectrometry (FAAS). The adopted concentrations for MPKO, Triton X-114 and HNO{sub 3}, bath temperature, centrifuge rate and time were optimized. Detection limits (3 SDb/m) of 1.6, 2.1 and 1.9 ng mL{sup -1} for Cu{sup 2+}, Co{sup 2+} and Ni{sup 2+} along with preconcentration factors of 30 and for these ions and enrichment factor of 65, 58 and 67 for Cu{sup 2+}, Ni{sup 2+} and Co{sup 2+}, respectively. The high efficiency of cloud point extraction to carry out the determination of analytes in complex matrices was demonstrated. The proposed procedure was applied to the analysis of biological, natural and wastewater, soil and blood samples.

  6. Correlation between Copper Ion Concentration in Cervical Mucus and Fllbrinolytic Activity in Menstrual Blood in Copper-releasiag IUD Users

    Institute of Scientific and Technical Information of China (English)

    林建华; 潘家骧; 严隽鸿

    1993-01-01

    In the present study, 44 women using TCu220c-IUD or inert-IUD were asked to make follow-ups before insertion and at the 1st., 3rd., 6th, 9th and 12th month after insertion The mean menstrual blood loss, the fibrinalytic activity including the activation of tissue-plasminogen activator (t-PA) and the amount of plasminogen PIG) and fibrinogen-fibrin degradation products (FDP) in menstrual blood and the copper ion concentration in cervical mucus were determined. The correlation between the copper ion concentration and the fibrinalytic activity was considered. It was found that the change of the copper ion concentration was positively correlated with that of the activition of t-PA and the amount of FDP. On the contrary, the change ofthe copper ion concentration was inversely related to the change of PLG value. It is concluded that the high copper ion level can enhance the activation of fibrinolytic system in human endometrium and induce the increase of menorrhagia.

  7. Effects of roof and rainwater characteristics on copper concentrations in roof runoff.

    Science.gov (United States)

    Bielmyer, Gretchen K; Arnold, W Ray; Tomasso, Joseph R; Isely, Jeff J; Klaine, Stephen J

    2012-05-01

    Copper sheeting is a common roofing material used in many parts of the world. However, copper dissolved from roof sheeting represents a source of copper ions to watersheds. Researchers have studied and recently developed a simple and efficient model to predict copper runoff rates. Important input parameters include precipitation amount, rain pH, and roof angle. We hypothesized that the length of a roof also positively correlates with copper concentration (thus, runoff rates) on the basis that runoff concentrations should positively correlate with contact time between acidic rain and the copper sheet. In this study, a novel system was designed to test and model the effects of roof length (length of roof from crown to the drip edge) on runoff copper concentrations relative to rain pH and roof angle. The system consisted of a flat-bottom copper trough mounted on an apparatus that allowed run length and slope to be varied. Water of known chemistry was trickled down the trough at a constant rate and sampled at the bottom. Consistent with other studies, as pH of the synthetic rainwater decreased, runoff copper concentrations increased. At all pH values tested, these results indicated that run length was more important in explaining variability in copper concentrations than was the roof slope. The regression equation with log-transformed data (R(2) = 0.873) accounted for slightly more variability than the equation with untransformed data (R(2) = 0.834). In log-transformed data, roof angle was not significant in predicting copper concentrations.

  8. Lethal copper concentration levels for Clarias gariepinus (Burchell, 1822 @ a preliminary study

    Directory of Open Access Journals (Sweden)

    Marinda Van der Merwe

    1993-09-01

    Full Text Available Lethal copper concentrations were determined for both adult and juvenile Clarias gariepinus at representative mean summer and winter temperatures. Fish were exposed to copper for 96 hours in an experimental system and mortalities monitored. Toxicity curves of percentage mortality versus actual copper concentration were drawn, and the LC50 calculated for winter and summer temperatures. The lethal copper concentrations, expressed as LC50, found in laboratory exposures, ranged for adults from 1,29 mg/1 during summer to 1,38 mg/1 in winter. These values are considerably higher than the levels of copper in the water of the Olifants River in the Kruger National Park during summer (0,055 @ 0,016 mg/1 and winter (0,085 @ 0,032 mg/1. The derived LC50 values predict the level of copper which should be prevented at all cost. The fish in the Olifants River are already exposed to sublethal concentrations (40 of LC50 of copper. The results can be used as an indication of what the safe concentrations of copper should be.

  9. Effect of high soil copper concentration on mycorrhizal grapevines

    Science.gov (United States)

    Nogales, Amaia; Santos, Erika S.; Viegas, Wanda; Aran, Diego; Pereira, Sofia H.; Vidigal, Patricia; Lopes, Carlos M.; Abreu, M. Manuela

    2017-04-01

    Repeated application of Copper (Cu) based fungicides in vineyards since the end of the 19th century has led to a significant increase in the concentration of this chemical element in many viticultural soils. Although Cu is an essential micronutrient for most organisms, it can be toxic for the development and survival of plants and soil (micro)organisms at high concentrations and eventually lead to yield loses in viticulture, as it negatively affects key physiological and biogeochemical processes. However, some soil microorganisms, including arbuscular mycorrhizal fungi (AMF), have developed adaptive mechanisms for persistence in environments with supra-optimal levels of essential elements or in the presence of harmful ones, as well as for increasing plant tolerance to such abiotic stress conditions. The objective of this work was to evaluate the effect of a high total soil concentration of Cu on microbial soil activity as well as on the development of mycorrhizal and non-mycorrhizal grapevines. A microcosm assay was set up under greenhouse and controlled conditions. Touriga Nacional grapevine variety plants grafted onto 1103P rootstocks were inoculated either with the AMF Rhizophagus irregularis or Funneliformis mosseae, or were left as non-inoculated controls. After three months, they were transplanted to containers filled with 4 kg of a sandy soil (pH: 7.0; electrical conductivity: 0.08 mS/cm; [organic C]: 5.6 g/kg; [N-NO3]: 1.1 mg/kg; [N-NH4]: 2.5 mg/kg; [extractable K]: 45.1 mg/kg; [extractable P]: 52.3 mg/kg), collected near to a vineyard in Pegões (Portugal). Two treatments were carried out: with and without Cu application. The soil with high Cu concentration was prepared by adding 300 mg Cu/kg (in the form of an aqueous solution of CuSO4·5H2O) followed by an incubation during four weeks in plastic bags at room temperature in dark. Physico-chemical soil characteristics (pH, electrical conductivity and nutrients concentration in available fraction), soil

  10. The influence of the silicate slag composition on copper losses during smelting of the sulfide concentrates

    Directory of Open Access Journals (Sweden)

    Živković Živan

    2009-01-01

    Full Text Available This paper presents the results of multi-linear regression analysis (MLRA of the slag composition (SiO2, FeO, Fe3O4, CaO, Al2O3 and the content of copper in the matte on resulting copper content in the slag during smelting of the sulfide concentrates in the reverberatory furnace. When comparing results obtained with MLRA model calculations with values measured at industrial level high degree of fitting is obtained (R2 = 0.974. This indicates that slag composition and content of copper in the matte influences the copper losses in the waste slag with the probability of 95 %.

  11. Effect of Sulfide Concentration on Copper Corrosion in Anoxic Chloride-Containing Solutions

    Science.gov (United States)

    Kong, Decheng; Dong, Chaofang; Xu, Aoni; Man, Cheng; He, Chang; Li, Xiaogang

    2017-02-01

    The structure and property of passive film on copper are strongly dependent on the sulfide concentration; based on this, a series of electrochemical methods were applied to investigate the effect of sulfide concentration on copper corrosion in anaerobic chloride-containing solutions. The cyclic voltammetry and x-ray photoelectron spectroscopy analysis demonstrated that the corrosion products formed on copper in anaerobic sulfide solutions comprise Cu2S and CuS. And the corrosion resistance of copper decreased with increasing sulfide concentration and faster sulfide addition, owing to the various structures of the passive films observed by the atomic force microscope and scanning electron microscope. A p-type semiconductor character was obtained under all experimental conditions, and the defect concentration, which had a magnitude of 1022-1023 cm-3, increased with increasing sulfide concentration, resulting in a higher rate of both film growth and dissolution.

  12. Case study of the 9 April 2009 ‘brown’ cloud: Observations of usually high cloud droplet concentrations in Saudi Arabia

    Science.gov (United States)

    Delene, D. J.

    2009-12-01

    Cloud droplets nucleate on aerosol particles termed cloud condensation nuclei (CCN). It is well known that a larger number concentration of CCN results in a larger number concentration of droplets in developing cumulus clouds. However, the conditions where dust particles can serve as cloud condensation nuclei (CCN) and hence change cloud droplet concentration and precipitation formation processes is uncertain. Aircraft measurements of cloud droplet concentration between 13:20 and 13:30 UTC during the 9 April 2009 flight near Riyadh, Saudi Arabia, show total cloud droplet concentration (3-50 µm in diameter) of 800 to 1200 #/cm-3 at a altitude of 18000 ft. Typical cloud droplet concentration for this type of cloud in the Riyadh region is approximately 400 #/cm-3 and is typical of observation made between 13:00 and 13:20 UTC during the 9 April 2009 flight at 18,000 ft. Photographs of ice accumulation on the unprotected leading edge of the aircraft’s wing due to the freezing of super cooled droplets show a color changed from white during the time of low droplet number condensation to brown during the high droplet number concentration. It is hypothesized that high droplet number concentration observations were the result of ingestion of a large about of dust particles by the cloud. : Case Study of the 9 April 2009 ‘Brown’ Cloud: Observations of Usually High Cloud Droplet Concentrations in Saudi Arabia.

  13. Study on copper complexing ligand concentrations in several China's coastal waters

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Copper complexing ligand concentrations in the Daya Bay, Qingdao coast, Jiaozhou Bay, South China Sea and Huanghe Estuary waters were determined by the anodic stripping voltammetry technique. The distribution regularity and the relationship with other parameters were discussed. The results were as follows: Copper complexing ligand concentrations of the South China Sea were a little higher than those of other sea areas, and they were apparently higher than those of the ocean. Compared with the subsurface layer (SSL) in the sea surface microlayer copper complexing ligand concentrations showed an enrichment phenomenon, of which the mechanism is similar to dissolved organic matter. The metal complexing ligand concentration profiles of the South China Sea showed that the value in the sea surface was the highest, then it decreased with depth accruing, and a higher value appeared at the bottom. Copper complexing ligand concentrations were higher than those of cadmium and lead. Ligands in each sea area exhibited a complicated property. In short, the distribution regularity of copper complexing ligand concentrations in China' s coastal waters was consistent with that of other regions in the world. Meanwhile, the positive relationship between the copper complexing ligand concentrations and biological oxygen demand, chemical oxygen demand, dissolved organic carbon, and viscosity were found clearly.

  14. Observational evidence of high ice concentration in a shallow convective cloud embedded in stratiform cloud over North China

    Science.gov (United States)

    Yang, Jiefan; Lei, Hengchi; Hou, Tuanjie

    2017-04-01

    In this study we observed the microphysical properties, including the vertical and horizontal distributions of ice particles, liquid water content and ice habit, in different regions of a slightly supercooled stratiform cloud. Using aircraft instrument and radar data, the cloud top temperature was recorded as higher than -15°C, behind a cold front, on 9 September 2015 in North China. During the flight sampling, the high ice number concentration area was located in the supercooled part of a shallow convective cloud embedded in a stratiform cloud, where the ambient temperature was around -3°C. In this area, the maximum number concentrations of particles with diameter greater than 100 μm and 500 μm ( N 100 and N 500) exceeded 300 L-1 and 30 L-1, respectively, and were related to large supercooled water droplets with diameter greater than 24 μm derived from cloud-aerosol spectrometer probe measurements. The ice particles types in this region were predominantly columnar, needle, graupel, and some freezing drops, suggesting that the occurrence of high ice number concentrations was likely related to the Hallett-Mossop mechanism, although many other ice multiplication processes cannot be totally ruled out. The maximum ice number concentration obtained during the first penetration was around two to three orders of magnitude larger than that predicted by the Demott and Fletcher schemes when assuming the cloud top temperature was around -15°C. During the second penetration conducted within the stratiform cloud, N 100 and N 500 decreased by a factor of five to ten, and the presence of columnar and needle-like crystals became very rare.

  15. Retrieval of Atmospheric CO2 Concentration above Clouds and Cloud Top Pressure from Airborne Lidar Measurements during ASCENDS Science Campaigns

    Science.gov (United States)

    Mao, J.; Ramanathan, A. K.; Rodriguez, M.; Allan, G. R.; Hasselbrack, W. E.; Abshire, J. B.; Riris, H.; Kawa, S. R.

    2014-12-01

    NASA Goddard is developing an integrated-path, differential absorption (IPDA) lidar approach to measure atmospheric CO2 concentrations from space as a candidate for NASA's ASCENDS (Active Sensing of CO2 Emissions over Nights, Days, and Seasons) mission. The approach uses pulsed lasers to measure both CO2 and O2 absorption simultaneously in the vertical path to the surface at a number of wavelengths across a CO2 line at 1572.335 nm and an O2 line doublet near 764.7 nm. Measurements of time-resolved laser backscatter profiles from the atmosphere allow the technique to estimate column CO2 and O2 number density and range to cloud tops in addition to those to the ground. This allows retrievals of CO2 column above clouds and cloud top pressure, and all-sky measurement capability from space. This additional information can be used to evaluate atmospheric transport processes and other remote sensing carbon data in the free atmosphere, improve carbon data assimilation in models and help global and regional carbon flux estimates. We show some preliminary results of this capability using airborne lidar measurements from the summers of 2011 and 2014 ASCENDS science campaigns. These show simultaneous retrievals of CO2 and O2 column densities for laser returns from low-level marine stratus clouds in the west coast of California. This demonstrates the supplemental capability of the future space carbon mission to measure CO2 above clouds, which is valuable particularly for the areas with persistent cloud covers, e.g, tropical ITCZ, west coasts of continents with marine layered clouds and southern ocean with highest occurrence of low-level clouds, where underneath carbon cycles are active but passive remote sensing techniques using the reflected short wave sunlight are unable to measure accurately due to cloud scattering effect. We exercise cloud top pressure retrieval from O2 absorption measurements during the flights over the low-level marine stratus cloud decks, which is one of

  16. Copper nanoparticles exert size and concentration dependent toxicity on somatosensory neurons of rat

    Science.gov (United States)

    PRABHU, BADANAVALU M.; ALI, SYED F.; MURDOCK, RICHARD C.; HUSSAIN, SABER M.; SRIVATSAN, MALATHI

    2010-01-01

    Metal nanoparticles, due to their unique properties and important applications in optical, magnetic, thermal, electrical, sensor devices and cosmetics, are beginning to be widely manufactured and used. This new and rapidly growing field of technology warrants a thorough examination of the material’s bio-compatibility and safety. Ultra-small particles may adversely affect living cells and organisms since they can easily penetrate the body through skin contact, inhalation and ingestion. Retrograde transport of copper nanoparticles from nerve endings on the skin can reach the somatosensory neurons in dorsal root ganglion (DRG). Since copper nanoparticles have industrial and healthcare applications, we determined the concentration and size-dependant effects of their exposure on survival of DRG neurons of rat in cell culture. The neurons were exposed to copper nanoparticles of increasing concentrations (10–100 μM) and sizes (40, 60 and 80 nm) for 24 h. Light microscopy, histochemical staining for copper, lactate dehydrogenase (LDH) assay for cell death, and MTS [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay for cell viability were performed to measure the resultant toxicity and cell survival. DRG neurons exposed to copper nanoparticles displayed vacuoles and detachment of some neurons from the substratum. Neurons also exhibited disrupted neurite network. LDH and MTS assays revealed that exposure to copper nanoparticles had significant toxic effect with all the sizes tested when compared to unexposed control cultures. Further analysis of the results showed that copper nanoparticles of smaller size and higher concentration exerted the maximum toxic effects. Rubeanic acid staining showed intracellular deposition of copper. These results demonstrate that copper nanoparticles are toxic in a size- and concentration-dependent manner to DRG neurons. PMID:20543894

  17. A reliable method of quantification of trace copper in beverages with and without alcohol by spectrophotometry after cloud point extraction

    OpenAIRE

    Ramazan Gürkan; Nail Altunay

    2013-01-01

    A new cloud point extraction (CPE) method was developed for the separation and preconcentration of copper (II) prior to spectrophotometric analysis. For this purpose, 1-(2,4-dimethylphenyl) azonapthalen-2-ol (Sudan II) was used as a chelating agent and the solution pH was adjusted to 10.0 with borate buffer. Polyethylene glycol tert-octylphenyl ether (Triton X-114) was used as an extracting agent in the presence of sodium dodecylsulphate (SDS). After phase separation, based on the cloud point...

  18. Effect of Flotation Reagents on the Cake Moisture of Copper Concentrate

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The effect of reagents used in separating chalcopyrite from pyrite on the cake moisture of the copper concentrate at Daye Iron Mine Mineral Processing Plant was investigated. The results showed that the dosage of lime used for depressing pyrite was the main factor that increased the filter cake moisture of copper concentrate. With increasing the dosage of lime, the cake moisture of copper concentrate increased sharply. The cause was concluded to be the addition of lime to the pulp, which resulted in the formation of floc and a high pH value. The collector Z-200#, used for collecting chalcopyrite, had, as well, an adverse effect on the cake moisture of copper concentrate, but its effect was inferior in respect to that of lime. The cake moisture of copper concentrate can be decreased by changing the method with which lime is added and the pH value of pulp is regulated. The experiment results showed that the sulfuric acid was the best regulator. When the clarified liquor of lime was used as a depressant and the pH value of the pulp was regulated to 6.5€?7.0 by adding sulfuric acid, the cake moisture of copper concentrate was reduced from 15.49% to 13.13%. The examination of chalcopyrite surface by using ESCA (Electron Spectroscopy for Chemical Analysis) showed that calcium sulfate and iron hydroxide had formed on the surface of chalcopyrite when lime was added to the pulp. The formation of calcium sulfate and iron hydroxide on its surface increased the hydrophilicity of chalcopyrite so that its cake moisture increased. The addition of sulfuric acid to the pulp not only removed the calcium sulfate, but also reduced the concentration of iron hydroxide on the surface of chalcopyrite so that the cake moisture of copper concentrate was decreased.

  19. Environmental and toenail metals concentrations in copper mining and non mining communities in Zambia.

    Science.gov (United States)

    Ndilila, Wesu; Callan, Anna Carita; McGregor, Laura A; Kalin, Robert M; Hinwood, Andrea L

    2014-01-01

    Copper mining contributes to increased concentrations of metals in the environment, thereby increasing the risk of metals exposure to populations living in and around mining areas. This study investigated environmental and toenail metals concentrations of non-occupational human exposure to metals in 39 copper-mining town residents and 47 non-mining town residents in Zambia. Elevated environmental concentrations were found in samples collected from the mining town residents. Toenail concentrations of cobalt (GM 1.39 mg/kg), copper (GM 132 mg/kg), lead (21.41 mg/kg) selenium (GM 0.38 mg/kg) and zinc (GM 113 mg/kg) were significantly higher in the mining area and these metals have previously been associated with copper mining. Residence in the mining area, drinking water, dust and soil metals concentrations were the most important contributors to toenail metals concentrations. Further work is required to establish the specific pathways of exposure and the health risks of elevated metals concentrations in the copper mining area.

  20. A reliable method of quantification of trace copper in beverages with and without alcohol by spectrophotometry after cloud point extraction

    Directory of Open Access Journals (Sweden)

    Ramazan Gürkan

    2013-01-01

    Full Text Available A new cloud point extraction (CPE method was developed for the separation and preconcentration of copper (II prior to spectrophotometric analysis. For this purpose, 1-(2,4-dimethylphenyl azonapthalen-2-ol (Sudan II was used as a chelating agent and the solution pH was adjusted to 10.0 with borate buffer. Polyethylene glycol tert-octylphenyl ether (Triton X-114 was used as an extracting agent in the presence of sodium dodecylsulphate (SDS. After phase separation, based on the cloud point of the mixture, the surfactant-rich phase was diluted with acetone, and the enriched analyte was spectrophotometrically determined at 537 nm. The variables affecting CPE efficiency were optimized. The calibration curve was linear within the range 0.285-20 µg L-1 with a detection limit of 0.085 µg L-1. The method was successfully applied to the quantification of copper in different beverage samples.

  1. Statistical modeling of copper losses in the silicate slag of the sulfide concentrate smelting process

    OpenAIRE

    2015-01-01

    This article presents the results of the statistical modeling of copper losses in the silicate slag of the sulfide concentrates smelting process. The aim of this study was to define the correlation dependence of the degree of copper losses in the silicate slag on the following parameters of technological processes: SiO2, FeO, Fe3O4, CaO and Al2O3 content in the slag and copper content in the matte. Multiple linear regression analysis (MLRA), artificial neural networks (ANNs) and adaptive netw...

  2. The influence of the silicate slag composition on copper losses during smelting of the sulfide concentrates

    OpenAIRE

    2009-01-01

    This paper presents the results of multi-linear regression analysis (MLRA) of the slag composition (SiO2, FeO, Fe3O4, CaO, Al2O3) and the content of copper in the matte on resulting copper content in the slag during smelting of the sulfide concentrates in the reverberatory furnace. When comparing results obtained with MLRA model calculations with values measured at industrial level high degree of fitting is obtained (R2 = 0.974). This indicates that slag composition and content of copper in t...

  3. Serum zinc and copper concentrations in maternal and umbilical cord blood. Relation to course and outcome of pregnancy

    DEFF Research Database (Denmark)

    Bro, S; Berendtsen, H; Nørgaard, J;

    1988-01-01

    higher serum copper levels than reference infants and mothers (p = 0.02 and p = 0.04, respectively), whereas there was no difference in serum zinc concentrations. Serum zinc and copper concentrations in malformed infants (n = 14) and their mothers (n = 17) did not differ from concentrations in reference...... serum zinc and copper concentrations in maternal and umbilical cord blood from 500 Danish mothers at delivery, looking for an association between serum zinc and copper levels and various maternal and foetal complications. Preterm infants (n = 30) had significantly lower serum copper concentrations than...... reference infants (n = 346) (p = 0.01), whereas there was no difference in serum zinc concentrations. Mothers of preterm infants (n = 34) did not differ in serum zinc or copper concentrations from reference mothers (n = 220). Small for date infants (n = 37) and mothers of small for date infants (n = 47) had...

  4. Sediment-copper distributions in hyper-concentrated turbulent solid-liquid system

    Institute of Scientific and Technical Information of China (English)

    YANG Jun; NI Jin-ren

    2007-01-01

    This study presents a special problem on vertical distribution for sediment and copper in hyper-concentrated turbulent solid-liquid system that is essentially different from the ordinary low-concentrated turbulent system. A resonance type turbulent simulation equipment is used for the experimental study in which a vertically uniform turbulent field of the mixture of loess and water is produced in a testing cylinder with a grille stirrer that moves up and down harmoniously with varying vibration frequencies. In order to compare the variations of the vertical profiles of sediment and copper in low- and hyper-concentrated solid-liquid system, different scenarios for input sediment content ranging from 5 to 800 kg/m3 was considered in the experimental studies. It was found that solids copper content increases with input sediment content, S0, and reaches its peak as S0 goes to 10 kg/m3 and then decreases rapidly with increasing input sediment content. Such a behavior is possibly resulted from the joint effect of the specific adsorption of copper on loess, precipitation of carbonate and hydroxide of copper due to high carbonate content in the loess and the so-called "particulate concentration effect" due to the present of the sediment variation in water. The vertical sediment concentration distribution resulted from the uniform turbulence is generally uniform, but slight non-uniformity does occur as sediment concentration exceeds certain value. However, the vertical concentration distributions of soluble copper seem not affected much by the variation of sediment concentrations.

  5. Combined effects of water flow and copper concentration on the feeding behavior, growth rate, and accumulation of copper in tissue of the infaunal polychaete Polydora cornuta.

    Science.gov (United States)

    Colvin, Marienne A; Hentschel, Brian T; Deheyn, Dimitri D

    2016-12-01

    We performed an experiment in a laboratory flume to test the effects of water flow speed and the concentration of aqueaous copper on the feeding behavior, growth rate, and accumulation of copper in the tissues of juvenile polychaetes Polydora cornuta. The experiment included two flow speeds (6 or 15 cm/s) and two concentrations of added copper (0 or 85 μg/L). Worms grew significantly faster in the faster flow and in the lower copper concentration. In the slower flow, the total time worms spent feeding decreased significantly as copper concentration increased, but copper did not significantly affect the time worms spent feeding in the faster flow. Across all treatments, there was a significant, positive relationship between the time individuals spent feeding and their relative growth rate. Worms were observed suspension feeding significantly more often in the faster flow and deposit feeding significantly more often in the slower flow, but copper concentration did not affect the proportion of time spent in either feeding mode. The addition of 85 μg/L copper significantly increased copper accumulation in P. cornuta tissue, but the accumulation did not differ significantly due to flow speed. There was a significant interaction between copper and flow; the magnitude of the difference in copper accumulation between the 0 and 85 μg/L treatments was greater in the faster flow than in the slower flow. In slow flows that favor deposit feeding, worms grow slowly and accumulate less copper in their tissue than in faster flows that favor suspension feeding and faster growth.

  6. Effects of turbulence on warm clouds and precipitation with various aerosol concentrations

    Science.gov (United States)

    Lee, Hyunho; Baik, Jong-Jin; Han, Ji-Young

    2015-02-01

    This study investigates the effects of turbulence-induced collision enhancement (TICE) on warm clouds and precipitation by changing the cloud condensation nuclei (CCN) number concentration using a two-dimensional dynamic model with bin microphysics. TICE is determined according to the Taylor microscale Reynolds number and the turbulent dissipation rate. The thermodynamic sounding used in this study is characterized by a warm and humid atmosphere with a capping inversion layer, which is suitable for simulating warm clouds. For all CCN concentrations, TICE slightly reduces the liquid water path during the early stage of cloud development and accelerates the onset of surface precipitation. However, changes in the rainwater path and in the amount of surface precipitation that are caused by TICE depend on the CCN concentrations. For high CCN concentrations, the mean cloud drop number concentration (CDNC) decreases and the mean effective radius increases due to TICE. These changes cause an increase in the amount of surface precipitation. However, for low CCN concentrations, changes in the mean CDNC and in the mean effective radius induced by TICE are small and the amount of surface precipitation decreases slightly due to TICE. A decrease in condensation due to the accelerated coalescence between droplets explains the surface precipitation decrease. In addition, an increase in the CCN concentration can lead to an increase in the amount of surface precipitation, and the relationship between the CCN concentration and the amount of surface precipitation is affected by TICE. It is shown that these results depend on the atmospheric relative humidity.

  7. Combined effects of water temperature and copper ion concentration on catalase activity in Crassostrea ariakensis

    Science.gov (United States)

    Wang, Hui; Yang, Hongshuai; Liu, Jiahui; Li, Yanhong; Liu, Zhigang

    2015-07-01

    A central composite experimental design and response surface method were used to investigate the combined effects of water temperature (18-34°C) and copper ion concentration (0.1-1.5 mg/L) on the catalase (CAT) activity in the digestive gland of Crassostrea ariakensis. The results showed that the linear effects of temperature were significant ( P0.05), and the quadratic effects of copper ion concentration were significant ( P0.05), and the effect of temperature was greater than that of copper ion concentration. A model equation of CAT enzyme activity in the digestive gland of C. ariakensis toward the two factors of interest was established, with R 2, Adj. R 2 and Pred. R 2 values as high as 0.943 7, 0.887 3 and 0.838 5, respectively. These findings suggested that the goodness of fit to experimental data and predictive capability of the model were satisfactory, and could be practically applied for prediction under the conditions of the study. Overall, the results suggest that the simultaneous variation of temperature and copper ion concentration alters the activity of the antioxidant enzyme CAT by modulating active oxygen species metabolism, which may be utilized as a biomarker to detect the effects of copper pollution.

  8. Feasibility Studies on Pipeline Disposal of Concentrated Copper Tailings Slurry for Waste Minimization

    Science.gov (United States)

    Senapati, Pradipta Kumar; Mishra, Barada Kanta

    2017-06-01

    The conventional lean phase copper tailings slurry disposal systems create pollution all around the disposal area through seepage and flooding of waste slurry water. In order to reduce water consumption and minimize pollution, the pipeline disposal of these waste slurries at high solids concentrations may be considered as a viable option. The paper presents the rheological and pipeline flow characteristics of copper tailings samples in the solids concentration range of 65-72 % by weight. The tailings slurry indicated non-Newtonian behaviour at these solids concentrations and the rheological data were best fitted by Bingham plastic model. The influence of solids concentration on yield stress and plastic viscosity for the copper tailings samples were discussed. Using a high concentration test loop, pipeline experiments were conducted in a 50 mm nominal bore (NB) pipe by varying the pipe flow velocity from 1.5 to 3.5 m/s. A non-Newtonian Bingham plastic pressure drop model predicted the experimental data reasonably well for the concentrated tailings slurry. The pressure drop model was used for higher size pipes and the operating conditions for pipeline disposal of concentrated copper tailings slurry in a 200 mm NB pipe with respect to specific power consumption were discussed.

  9. Feasibility Studies on Pipeline Disposal of Concentrated Copper Tailings Slurry for Waste Minimization

    Science.gov (United States)

    Senapati, Pradipta Kumar; Mishra, Barada Kanta

    2016-06-01

    The conventional lean phase copper tailings slurry disposal systems create pollution all around the disposal area through seepage and flooding of waste slurry water. In order to reduce water consumption and minimize pollution, the pipeline disposal of these waste slurries at high solids concentrations may be considered as a viable option. The paper presents the rheological and pipeline flow characteristics of copper tailings samples in the solids concentration range of 65-72 % by weight. The tailings slurry indicated non-Newtonian behaviour at these solids concentrations and the rheological data were best fitted by Bingham plastic model. The influence of solids concentration on yield stress and plastic viscosity for the copper tailings samples were discussed. Using a high concentration test loop, pipeline experiments were conducted in a 50 mm nominal bore (NB) pipe by varying the pipe flow velocity from 1.5 to 3.5 m/s. A non-Newtonian Bingham plastic pressure drop model predicted the experimental data reasonably well for the concentrated tailings slurry. The pressure drop model was used for higher size pipes and the operating conditions for pipeline disposal of concentrated copper tailings slurry in a 200 mm NB pipe with respect to specific power consumption were discussed.

  10. Occurrence mechanism of silicate and aluminosilicate minerals in Sarcheshmeh copper flotation concentrate

    Institute of Scientific and Technical Information of China (English)

    H.R. Barkhordari; E. Jorjani; A. Eslami; M. Noaparast

    2009-01-01

    The Sarcheshmeh copper flotation circuit is producing 5×10~4 t copper concentrate per month with an averaging grade of 28% Cu in rougher, cleaner and reeleaner stages. In recent years, with the increase in the open pit depth, the content of aluminosili- cate minerals increased in plant feed and subsequently in flotation concentrate. It can motivate some problems, such as unwanted consumption of reagents, decreasing of the copper concentrate grade, increasing of Al_2O_3 and SiO_2 in the copper concentrate, and needing a higher temperature in the smelting process. The evaluation of the composite samples related to the most critical working period of the plant shows that quartz, illite, biotite, chlorite, orthoclase, albeit, muscovite, and kaolinite are the major Al_2O_3 and SiO_2 beating minerals that accompany chalcopyrite, chalcoeite, and covellite minerals in the plant feed. The severe alteration to clay min-erals was a general rule in all thin sections that were prepared from the plant feed. Sieve analysis of the flotation concentrate shows that Al_2O_3 and SiO_2 bearing minerals in the flotation concentrate can be decreased by promoting the size reduction from 53 to 38 μm. Interlocking of the Al_2O_3 and SiO_2 beating minerals with ehalcopyrite and ehalcocite is the occurrence mechanism of silicate and aluminosilicate minerals in the flotation concentrate. The dispersed form of interlocking is predominant.

  11. 7Be, 210Pb and 137Cs concentrations in cloud water.

    Science.gov (United States)

    Bourcier, L; Masson, O; Laj, P; Paulat, P; Pichon, J-M; Chausse, P; Gurriaran, R; Sellegri, K

    2014-02-01

    Cloud water was sampled during 8 months, in 2008 and 2009, at the puy de Dome high-altitude atmospheric research station (France). The concentrations of (7)Be and (210)Pb, both naturally occurring radionuclides, and (137)Cs of anthropogenic origin, were determined. Those values are useful for a better knowledge of the aftermath cloud deposition and more generally for wet deposition assessment of radionuclides. This is of primary interest in case of a nuclear accident, especially considering (137)Cs deposition, both for high-altitude locations that are regularly embedded by clouds and also for lowlands where fog can occur. The (7)Be and (210)Pb average activity concentrations in cloud water found were 1.9±0.11 mBq m(-3) air and 140±10 μBq m(-3) air, respectively. For (137)Cs, the average concentration was 0.14±0.02 μBq m(-3) air. This very low-level is representative of the long term post-accidental background level. Indeed, for the studied period, the last accidental (137)Cs release was that of Chernobyl accident, in April 1986. To our knowledge this is the first data about (137)Cs reference level determination in cloud water. The comparison between cloud water and rain water concentrations showed a ratio cloud/rain ranging between 3.4 and 8.1, in agreement with previous studies performed on inorganic compounds. Scavenging efficiencies of aerosols by cloud droplets were also calculated with the additional aerosol concentrations routinely measured at the station and were quite low (0.13-0.40) compared to what has previously been observed for inorganic soluble ions.

  12. Effect of copper concentration on the physical properties of copper doped NiO thin films deposited by spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Mani Menaka, S., E-mail: manimenaka.phy@gmail.com [PG and Research Department of Physics, Government Arts College, Coimbatore, 641018, Tamilnadu (India); Umadevi, G. [PG and Research Department of Physics, Government Arts College, Coimbatore, 641018, Tamilnadu (India); Manickam, M. [SRMV College of Arts and Science, Coimbatore, 641020, Tamilnadu (India)

    2017-04-15

    The spray pyrolysis (SP) technique is an important and powerful method for the preparation of nickel oxide (NiO) and copper-doped nickel oxide thin films. The best films were obtained when the substrate temperature, T{sub s} = 450 °C on glass substrates. Copper (Cu) concentrations in the films were varied from 0 to 8%. The effect of Cu concentration on the structural, morphological, spectral, optical, and electrical properties of the thin films were studied by X-ray diffraction (XRD), Scanning electron microscopy (SEM), Fourier transformed infrared spectroscopy (FTIR), UV–vis–NIR spectrophotometer, Hot probe and Hall system. The X-ray diffraction result shows the polycrystalline cubic structure of sprayed films with (200) preferred orientation. The variations of the structural parameters such as lattice parameters and grain sizes were investigated. The SEM image displays the surface morphology of the NiO and Cu:NiO thin films. The FTIR of the as-deposited films were associated with chemical identification. The optical transmittance and absorbance spectra of the films were measured by UV–vis–NIR spectrophotometer. The absorption coefficient and band gaps of the films were calculated using the optical method. All the NiO and Cu:NiO films were p-type. The resistivity of the above films decreases with the increase in copper concentration and so the conductivity of the films depend on the precursor concentration. - Highlights: • Pure and Cu:NiO films were deposited by Spray pyrolysis technique. • The XRD result shows the polycrystalline nature of pure and Cu:NiO films. • The formation of pure and Cu:NiO were confirmed by FTIR analysis. • Band gap values of pure and Cu:NiO decreases. • All the pure and Cu:NiO films were p-type.

  13. Understanding Ice Supersaturation, Particle Growth, and Number Concentration in Cirrus Clouds

    Science.gov (United States)

    Comstock, Jennifer M.; Lin, Ruei-Fong; Starr, David O'C.; Yang, Ping

    2008-01-01

    Many factors control the ice supersaturation and microphysical properties in cirrus clouds. We explore the effects of dynamic forcing, ice nucleation mechanisms, and ice crystal growth rate on the evolution and distribution of water vapor and cloud properties in nighttime cirrus clouds using a one-dimensional cloud model with bin microphysics and remote sensing measurements obtained at the Department of Energy's Atmospheric Radiation Measurement (ARM) Climate Research Facility located near Lamont, OK. We forced the model using both large-scale vertical ascent and, for the first time, mean mesoscale velocity derived from radar Doppler velocity measurements. Both heterogeneous and homogeneous nucleation processes are explored, where a classical theory heterogeneous scheme is compared with empirical representations. We evaluated model simulations by examining both bulk cloud properties and distributions of measured radar reflectivity, lidar extinction, and water vapor profiles, as well as retrieved cloud microphysical properties. Our results suggest that mesoscale variability is the primary mechanism needed to reproduce observed quantities. Model sensitivity to the ice growth rate is also investigated. The most realistic simulations as compared with observations are forced using mesoscale waves, include fast ice crystal growth, and initiate ice by either homogeneous or heterogeneous nucleation. Simulated ice crystal number concentrations (tens to hundreds particles per liter) are typically two orders of magnitude smaller than previously published results based on aircraft measurements in cirrus clouds, although higher concentrations are possible in isolated pockets within the nucleation zone.

  14. A kinetic study of the copper-catalysed oxidative coupling of 2,6-dimethylphenol. The role of copper, base and phenol concentrations

    NARCIS (Netherlands)

    Baesjou, PJ; Driessen, WL; Challa, G; Reedijk, J

    1998-01-01

    The influence of varying concentrations and ratios of phenol, base and copper on the copper/N-methylimidazole catalysed oxidative coupling of 2,6-dimethylphenol (DMP) has been studied. The reaction obeys simple Michaelis-Menten kinetics with respect to the phenol. The amount of DPQ formed during the

  15. A kinetic study of the copper-catalysed oxidative coupling of 2,6-dimethylphenol. The role of copper, base and phenol concentrations

    NARCIS (Netherlands)

    Baesjou, PJ; Driessen, WL; Challa, G; Reedijk, J

    1998-01-01

    The influence of varying concentrations and ratios of phenol, base and copper on the copper/N-methylimidazole catalysed oxidative coupling of 2,6-dimethylphenol (DMP) has been studied. The reaction obeys simple Michaelis-Menten kinetics with respect to the phenol. The amount of DPQ formed during the

  16. Zinc, copper, iron, and chromium concentrations in young patients with type 2 diabetes mellitus.

    Science.gov (United States)

    Basaki, M; Saeb, M; Nazifi, S; Shamsaei, H A

    2012-08-01

    Homeostasis of trace elements can be disrupted by diabetes mellitus. On the other hand, disturbance in trace element status in diabetes mellitus may contribute to the insulin resistance and development of diabetic complications. The aim of present study was to compare the concentration of essential trace elements, zinc, copper, iron, and chromium in serum of patients who have type 2 diabetes mellitus (n = 20) with those of nondiabetic control subjects (n = 20). The serum concentrations of zinc, copper, iron, and chromium were measured by means of an atomic absorption spectrophotometer (Shimadzu AA 670, Kyoto, Japan) after acid digestion. The results of this study showed that the mean values of zinc, copper, and chromium were significantly lower in the serum of patients with diabetes as compared to the control subjects (P diabetes mellitus.

  17. Leaching of a copper flotation concentrate with ammonium persulfate in an autoclave system

    Science.gov (United States)

    Deniz Turan, M.; Soner Altundoğan, H.

    2014-09-01

    The leaching behavior of a copper flotation concentrate was investigated using ammonium persulfate (APS) in an autoclave system. The decomposition products of APS, active oxygen, and acidic medium were used to extract metals from the concentrate. Leaching experiments were performed to compare the availability of APS as an oxidizing agent for leaching of the concentrate under atmospheric conditions and in an autoclave system. Leaching temperature and APS concentration were found to be important parameters in both leaching systems. Atmospheric leaching studies showed that the metal extractions increased with the increase in APS concentration and temperature (up to 333 K). A similar tendency was determined in the autoclave studies up to 423 K. It was also determined that the metal extractions decreased at temperatures above 423 K due to the passivation of the particle surface by molten elemental sulfur. The results showed that higher copper extractions could be achieved using an autoclave system.

  18. Leaching of a copper flotation concentrate with ammonium persulfate in an autoclave system

    Institute of Scientific and Technical Information of China (English)

    M Deniz Turan; H Soner Altundoan

    2014-01-01

    The leaching behavior of a copper flotation concentrate was investigated using ammonium persulfate (APS) in an autoclave sys-tem. The decomposition products of APS, active oxygen, and acidic medium were used to extract metals from the concentrate. Leaching ex-periments were performed to compare the availability of APS as an oxidizing agent for leaching of the concentrate under atmospheric condi-tions and in an autoclave system. Leaching temperature and APS concentration were found to be important parameters in both leaching sys-tems. Atmospheric leaching studies showed that the metal extractions increased with the increase in APS concentration and temperature (up to 333 K). A similar tendency was determined in the autoclave studies up to 423 K. It was also determined that the metal extractions de-creased at temperatures above 423 K due to the passivation of the particle surface by molten elemental sulfur. The results showed that higher copper extractions could be achieved using an autoclave system.

  19. Plasma copper, zinc and blood selenium concentrations of sheep ...

    African Journals Online (AJOL)

    Veek. 1 990, 20(3). Concentrations of plasma mpper, plasma zinc and blood selenium ... these breeds make them suitable for meat production in arid, cxtonsive regions. ..... effect of high levels of dietary molyMenum and sulphate on SA Mutton ...

  20. Utilization of Polyethylene Waste and Polypropylene Wastes for Formation of Fine Copper Ore Concentrates

    Science.gov (United States)

    Szyszka, Danuta; Więckowska, Jadwiga

    2016-10-01

    The possibilities for utilization of polyethylene waste and polypropylene waste as a binding material for formation of fine grain of copper ore concentrate in Hake Rheomix were examined. The optimum parameters of the formation processes were established. Strength, thermal and microscopic properties the products obtained were determined.

  1. Concentration fluctuations and averaging time in vapor clouds

    CERN Document Server

    Wilson, David J

    2010-01-01

    This book contributes to more reliable and realistic predictions by focusing on sampling times from a few seconds to a few hours. Its objectives include developing clear definitions of statistical terms, such as plume sampling time, concentration averaging time, receptor exposure time, and other terms often confused with each other or incorrectly specified in hazard assessments; identifying and quantifying situations for which there is no adequate knowledge to predict concentration fluctuations in the near-field, close to sources, and far downwind where dispersion is dominated by atmospheric t

  2. Statistical modeling of copper losses in the silicate slag of the sulfide concentrate smelting process

    Directory of Open Access Journals (Sweden)

    Savic Marija V.

    2015-09-01

    Full Text Available This article presents the results of the statistical modeling of copper losses in the silicate slag of the sulfide concentrates smelting process. The aim of this study was to define the correlation dependence of the degree of copper losses in the silicate slag on the following parameters of technological processes: SiO2, FeO, Fe3O4, CaO and Al2O3 content in the slag and copper content in the matte. Multiple linear regression analysis (MLRA, artificial neural networks (ANNs and adaptive network based fuzzy inference system (ANFIS were used as tools for mathematical analysis of the indicated problem. The best correlation coefficient (R2 = 0.719 of the final model was obtained using the ANFIS modeling approach.

  3. Activities of chromium in molten copper at dilute concentrations by solid-state electrochemical cell

    Science.gov (United States)

    Inouye, T. K.; Fujiwara, H.; Iwase, M.

    1991-08-01

    In order to obtain the activities of chromium in molten copper at dilute concentrations (copper was brought to equilibrium with molten CaCl2 + Cr2O3 slag saturated with Cr2O3 (s), at temperatures between 1423 and 1573 K, and the equilibrium oxygen partial pressures were measured by means of solid-oxide galvanic cells of the type Mo/Mo + MoO2/ZrO2(MgO)/(Cu + Cr))alloy + Cr2O3 + (CaCl2 + Cr2O3)slag/Mo. The free energy changes for the dissolution of solid chromium in molten copper at infinite dilution referred to 1 wt pct were determined as Cr (s) = Cr(1 wt pct, in Cu) and Δ G° = + 97,000 + 73.3 (T/K) ± 2,000 J mol-1.

  4. Removal of copper from molybdenite concentrate by mesophilic and extreme thermophilic microorganisms

    Institute of Scientific and Technical Information of China (English)

    Abdollahi Hadi; Manafi Zahra; Shafaei Sied Ziaedin; Noaparast Mohammad; Manafi Moorkani Navid

    2013-01-01

    Mixed mesophilic and extreme thermophilic bioleaching were evaluated to remove copper from the molybdenite concentrate. Bioleaching tests were carried out in shake flasks and in a 50-L bioreactor. The shake flask tests were performed with different inoculum size, solids density, pH, and temperature in order to identify optimum conditions. The highest amount of copper elimination, 75% was obtained with extreme thermophilic microorganisms (at 12%inoculation, 10%solids, 65 ºC and a pH of 1.5). The highest copper elimination by mesophilic microorganisms was 55% (at 12% inoculation, 5% solids, 30 ºC at pH 2). The optimum conditions in shake flask tests were applied to 7 days batch tests in a 50-L bioreactor. Extreme thermophilic experiment gave the best copper elimination of 60% (at 12%inoculation, 10%solids, 65 ºC and pH 1.5). Mesophilic test removed 50%of the copper (at 12%inoculation, 10%solids, 35 ºC at pH 2).

  5. Characterizing uncertainty in the motion, future location and ash concentrations of volcanic plumes and ash clouds

    Science.gov (United States)

    Webley, P.; Patra, A. K.; Bursik, M. I.; Pitman, E. B.; Dehn, J.; Singh, T.; Singla, P.; Stefanescu, E. R.; Madankan, R.; Pouget, S.; Jones, M.; Morton, D.; Pavolonis, M. J.

    2013-12-01

    Forecasting the location and airborne concentrations of volcanic ash plumes and their dispersing clouds is complex and knowledge of the uncertainty in these forecasts is critical to assess and mitigate the hazards that could exist. We show the results from an interdisciplinary project that brings together scientists drawn from the atmospheric sciences, computer science, engineering, mathematics, and geology. The project provides a novel integration of computational and statistical modeling with a widely-used volcanic particle dispersion code, to provide quantitative measures of confidence in predictions of the motion of ash clouds caused by volcanic eruptions. We combine high performance computing and stochastic analysis, resulting in real time predictions of ash cloud motion that account for varying wind conditions and a range of model variables. We show how coupling a real-time model for ash dispersal, PUFF, with a volcanic eruption model, BENT, allows for the definition of the variability in the dispersal model inputs and hence classify the uncertainty that can then propagate for the ash cloud location and downwind concentrations. We additionally analyze the uncertainty in the numerical weather prediction forecast data used by the dispersal model by using ensemble forecasts and assess how this affects the downwind concentrations. These are all coupled together and by combining polynomical chaos quadrature with stochastic integration techniques, we provide a quantitative measure of the reliability (i.e. error) of those predictions. We show comparisons of the downwind height calculations and mass loadings with observations of ash clouds available from satellite remote sensing data. The aim is to provide a probabilistic forecast of location and ash concentration that can be generated in real-time and used by those end users in the operational ash cloud hazard assessment environment.

  6. Leaching of copper concentrates using NaCl and soluble copper contributed by the own concentrate; Lixiviacion de concentrados de cobre utilizando NaCl y el cobre soluble aportado por el propio concentrado

    Energy Technology Data Exchange (ETDEWEB)

    Herrero, O.; Bernal, N.; Quiroz, R.; Fuentes, G.; Vinals, J.

    2005-07-01

    Leaching of copper concentrates using cupric chloro complexes, generated in situ by the reaction between Cu(II), aported by the soluble copper content of the concentrate, and sodium chloride in acid media was studied. The concentrate samples were obtained from mineral processing plants from Antofagasta, Chile. Chemical and mineralogical characterization from original concentrates was made. Typical variable such as a chloride concentration, soluble copper concentration, leaching time, solid percentage and temperature were studied. DRX and EDS analyzed some of the residues. the experimental results indicated that it is possible to obtain solutions having high copper content (15 to 35 g/L) and 2 to 5 g/L free acid in order to submit this solution directly to a solvent extraction stage. The leaching tests use common reactive and low cost such as sodium chloride and sulfuric acid. (Author) 16 refs.

  7. High Dietary Copper Increases Catecholamine Concentrations in the Hypothalami and Midbrains of Growing Pigs.

    Science.gov (United States)

    Yang, Wenyan; Zhao, Chunyu; Zhang, Cai; Yang, Lianyu

    2016-03-01

    The experiment was conducted to investigate the effect of high dietary copper on catecholamine concentration and dopamine-β-hydroxylase (DβH) activity in hypothalami and midbrains of growing pigs. Forty-five crossbred weanling pigs with an average body weight of 7.5 kg were randomly assigned to three groups of 15 each to receive a control diet containing 10 mg/kg Cu (diet A) and diets containing 125 (diet B) or 250 (diet C) mg Cu/kg DM for 45 days. Compared to the control, Cu supplementation at both 125 and 250 mg Cu/kg DM increased average daily gain (ADG), average daily feed intake (ADFI), and feed efficiency. High dietary copper increased midbrain and hypothalami dopamine (DA) and norepinephrine (NE) concentrations and midbrain dopamine-β-hydroxylase activity. However, increasing dietary Cu had no effect on hypothalami dopamine-β-hydroxylase activity.

  8. Estimating Of Etchant Copper Concentration In The Electrolytic Cell Using Artificial Neural Networks

    Directory of Open Access Journals (Sweden)

    Muzher M. Ibrahem

    2013-05-01

    Full Text Available      In  this paper, Artificial Neural Networks (ANN, which are known for their ability to model nonlinear systems, provide accurate approximations of system behavior and are typically much more computationally efficient than phenomenological models  are used to predict the etchant copper concentration in the electrolytic cell in terms of electric potential, operating time, temperature of the electrolytic cell , ratio of surface area of poles per unit volume of solution  and the distance between poles. In this paper 350 sets of data are used to trained and test the network.. The best results were achieved using a model based on a feedforword Artificial Neural Network (ANN with one hidden layer and fifteen neurons in the hidden layer gives a very close prediction of the copper concentration in the electrolytic cell.

  9. Determination of sulphide concentrates of ore copper by XRPD and chemical analysis

    Directory of Open Access Journals (Sweden)

    Cocić Mira B.

    2009-01-01

    Full Text Available Roasting process of sulphide copper concentrates in fluo-solid reactor is an oxidation process, and presents the first stage of copper concentrate processing in Copper Mining and Smelting Complex Bor, RTB Bor. Therefore, the importance of accurate and up to date process control is an apparent precondition for the correct treatment in the following stages and also for of high grade cathode copper. As concentrate is fed into the roaster, it is heated by a stream of hot air to about 590°C. The process takes place between solid and gaseous phases without the appearance of a liquid phase. The heat generated by the exothermic oxidation reaction of sulphur from cooper and iron minerals (chalcopyrite and pyrite is sufficient to carry out the entire process autogenously at temperature from 620 to 670°C. The temperature of sulphur firing which defines the start of roasting depends on physical traits, particle size of sulfides and characteristic product of oxidation. The obtained products of the roasting process are: calcine, ready for smelting in the furnace and gas-rich sulphure dioxide (SO2, well suited for the production of sulfuric acid. The relationship between the quantitative mineral composition of the charge and of the calcine directly points out to the efficiency of the roasting process in fluo-solid reactor. The amount of bornite and magnetite, resulting from the sulfide oxidation is the most important parameter. Hence, quantitative determination of mineral composition is of great interest. In this work, the results of the determination of quantitative mineral composition of the copper sulphide concentrate (charge and products of their roasting (calcine and overflow in fluo-solid reactor in the RTB Bor are presented. The aim was to compare the results of the iron, copper, sulfur and oxygen contents determined by two independent techniques, the chemical (HA and X-ray powder diffraction analysis (XRPD that is based on the quantitative mineral

  10. Estimating particle sizes, concentrations, and total mass of ash in volcanic clouds using weather radar

    Science.gov (United States)

    Harris, D. M.; Rose, W. I., Jr.

    1983-12-01

    Radar observations of the March 19, 1982 ash eruption of Mount St. Helens were used to estimate the volume of the ash cloud (2000 + or - 500 cu km), the concentration of ash (0.2-0.6 g/cu m), and the total mass of ash erupted (3-10 x 10 to the 11th g). Previously published ashfall data for the May 18, 1980 Mount St. Helens eruption were studied using an inversion technique to estimate 6-hr mean particle concentration (3 g/cu m), the size distribution, the total ashfall mass (5 x 10 to the 14th g), and radar reflectivity factors for the ash cloud. Because volcanic ash clouds with particle concentrations of at least 0.2 g/cu m are produced in very small (in terms of total ashfall mass) eruptions of duration less than 1 min, volcanic ash clouds must be considered an extremely serious hazard to in-flight aircraft, regardless of the eruption magnitude.

  11. Immunomodulating effects of environmentally realistic copper concentrations in Mytilus edulis adapted to naturally low salinities.

    Science.gov (United States)

    Höher, Nicole; Regoli, Francesco; Dissanayake, Awantha; Nagel, Matthias; Kriews, Michael; Köhler, Angela; Broeg, Katja

    2013-09-15

    The monitoring of organisms' health conditions by the assessment of their immunocompetence may serve as an important criterion for the achievement of the Good Environmental Status (GES) as defined in the Marine Strategy Framework Directive (EU). In this context, the complex role of natural environmental stressors, e.g. salinity, and interfering or superimposing effects of anthropogenic chemicals, should be carefully considered, especially in scenarios of low to moderate contamination. Organisms from the Baltic Sea have adapted to the ambient salinity regime, however energetically costly osmoregulating processes may have an impact on the capability to respond to additional stress such as contamination. The assessment of multiple stressors, encompassing natural and anthropogenic factors, influencing an organisms' health was the main aim of the present study. Immune responses of Mytilus edulis, collected and kept at natural salinities of 12‰ (LS) and 20‰ (MS), respectively, were compared after short-term exposure (1, 7 and 13 days) to low copper concentrations (5, 9 and 16 μg/L Cu). A significant interaction of salinity and copper exposure was observed in copper accumulation. LS mussels accumulated markedly more copper than MS mussels. No combined effects were detected in cellular responses. Bacterial clearance was mostly achieved by phagocytosis, as revealed by a strong positive correlation between bacterial counts and phagocytic activity, which was particularly pronounced in LS mussels. MS mussels, on the other hand, seemingly accomplished bacterial clearance by employing additional humoral factors (16 μg/L Cu). The greatest separating factor in the PCA biplot between LS and MS mussels was the proportion of granulocytes and hyalinocytes while functional parameters (phagocytic activity and bacterial clearance) were hardly affected by salinity, but rather by copper exposure. In conclusion, immune responses of the blue mussel may be suitable and sensitive

  12. Influences of in-cloud aerosol scavenging parameterizations on aerosol concentrations and wet deposition in ECHAM5-HAM

    Directory of Open Access Journals (Sweden)

    B. Croft

    2009-10-01

    Full Text Available A diagnostic nucleation scavenging scheme, which determines stratiform cloud scavenging ratios for both aerosol mass and number distributions, based on cloud droplet, and ice crystal number concentrations, is introduced into the ECHAM5-HAM global climate model. This is coupled with a size-dependent in-cloud impaction scavenging parameterization for both cloud droplet-aerosol, and ice crystal-aerosol collisions. Sensitivity studies are presented, which compare aerosol concentrations, and deposition between a variety of in-cloud scavenging approaches, including prescribed fractions, several diagnostic schemes, and a prognostic aerosol cloud processing treatment that passes aerosol in-droplet and in-ice crystal concentrations between model time steps. For one sensitivity study, assuming 100% of the in-cloud aerosol is scavenged into the cloud droplets and ice crystals, the annual global mean accumulation mode number burden is decreased by 65%, relative to a simulation with prognostic aerosol cloud processing. Diagnosing separate nucleation scavenging ratios for aerosol number and mass distributions, as opposed to equating the aerosol mass scavenging to the number scavenging ratios, reduces the annual global mean sulfate burden by near to 10%. The annual global mean sea salt burden is 30% lower for the diagnostic approach, which does not carry aerosol in-droplet and in-crystal concentrations between model time-steps as compared to the prognostic scheme. Implementation of in-cloud impaction scavenging reduced the annual, global mean black carbon burden by 30% for the prognostic aerosol cloud processing scheme. Better agreement with observations of black carbon profiles from aircraft (changes near to one order of magnitude for mixed phase clouds, 210Pb surface layer concentrations and wet deposition, and the geographic distribution of aerosol optical depth are found for the new diagnostic scavenging as compared to prescribed ratio

  13. [Copper concentration in women endometrium and in peripheral blood after prolonged use of intrauterine devices (author's transl)].

    Science.gov (United States)

    Kupfersztain, C C; Menache, R; Rubinstein, J; Halbrecht, I

    1976-01-01

    66 women were examined to determine the copper concentration in their serum and endometrium after prolonged use of an IUD (Lippes Loop, Hall Ring, Birnberg, Saf-T-Coil, Tatum, and Copper 7). A control of 16 nonusers was included. The level of copper was found by atomic absorption spectrophotometry. In the control group, the copper concentration in the serum was a mean of 100 gamma/100 cc of serum and in the endometrial tissue, a mean of 251 gamma/100 gm/wet tissue. In women using IUDs with no copper, the concentration in the serum was in the normal range, but in endometrial tissue it was between 457-586 gamma/100 gm. Similar findings came with the examination of women using IUDs containing copper. The high concentration of copper in inflamed endometrial tissue led to the hypothesis that such a condition, ith accompanying hyperenemia and hyperkinesia of the uterus and tubes are the principle factors for the contraceptive action of IUDs.

  14. Historical analysis of airborne beryllium concentrations at a copper beryllium machining facility (1964-2000).

    Science.gov (United States)

    McAtee, B L; Donovan, E P; Gaffney, S H; Frede, W; Knutsen, J S; Paustenbach, D J

    2009-06-01

    Copper beryllium alloys are the most commonly used form of beryllium; however, there have been few studies assessing occupational exposure in facilities that worked exclusively with this alloy versus those where pure metal or beryllium oxide may also have been present. In this paper, we evaluated the airborne beryllium concentrations at a machining plant using historical industrial hygiene samples collected between 1964 and 2000. With the exception of a few projects conducted in the 1960s, it is believed that >95% of the operations used copper beryllium alloy exclusively. Long-term (>120 min) and short-term (machining of copper beryllium-containing parts, as well as finishing operations (e.g., deburring and polishing) and decontamination of machinery. A total of 580 beryllium air samples were analyzed (311 personal and 269 area samples). The average concentration based on area samples (1964-2000) was 0.021 microg m(-3) (SD 0.17 microg m(-3); range 0.00012-2.5 microg m(-3)); 68.8% were below the analytical limit of detection (LOD). The average airborne beryllium concentration, based on all personal samples available from 1964 through the end of 2000 (n = 311), was 0.026 microg m(-3) (SD 0.059 microg m(-3); range 0.019-0.8 microg m(-3)); 97.4% were below the LOD. Personal samples collected from machinists (n = 78) had an average airborne concentration of 0.021 microg m(-3) (SD 0.014 microg m(-3); range 0.019-0.14 microg m(-3)); 97.4% were below the LOD. Airborne concentrations were consistently below the Occupational Safety and Health Administration permissible exposure limit for beryllium (2 microg m(-3)). Overall, the data indicate that for machining operations involving copper beryllium, the airborne concentrations for >95% of the samples were below the contemporaneous occupational exposure limits or the 1999 Department of Energy action level of 0.2 microg m(-3) and, in most cases, were below the LOD.

  15. Comparison of ultrasound-assisted cloud point extraction and ultrasound-assisted dispersive liquid liquid microextraction for copper coupled with spectrophotometric determination.

    Science.gov (United States)

    Yang, Shengchun; Fang, Xiang; Duan, Liju; Yang, Shu; Lei, Zirong; Wen, Xiaodong

    2015-09-01

    In this work, ultrasound-assisted cloud point extraction (UA-CPE) and ultrasound-assisted dispersive liquid liquid microextraction (UA-DLLME) were investigated and compared firstly as ultrasound-assisted liquid phase microextraction methods, which were coupled with spectrophotometer for copper preconcentration and detection. Compared to conventional CPE and DLLME, the extraction patterns were changed and improved by the effect of ultrasound. As novel methods, their applications were expanded and the analytical performance of spectrophotometric determination for copper was considerably improved. The influence factors of UA-CPE and UA-DLLME were studied in detail. Under the optimal conditions, the limits of detection (LODs) for copper were 0.7 μg L(-1) of UA-CPE and 0.8 μg L(-1) of UA-DLLME with sensitivity enhancement factors (EFs) of 17 and 16. The developed methods were applied to the determination of trace copper in real water samples with satisfactory analytical results.

  16. Comparison of ultrasound-assisted cloud point extraction and ultrasound-assisted dispersive liquid liquid microextraction for copper coupled with spectrophotometric determination

    Science.gov (United States)

    Yang, Shengchun; Fang, Xiang; Duan, Liju; Yang, Shu; Lei, Zirong; Wen, Xiaodong

    2015-09-01

    In this work, ultrasound-assisted cloud point extraction (UA-CPE) and ultrasound-assisted dispersive liquid liquid microextraction (UA-DLLME) were investigated and compared firstly as ultrasound-assisted liquid phase microextraction methods, which were coupled with spectrophotometer for copper preconcentration and detection. Compared to conventional CPE and DLLME, the extraction patterns were changed and improved by the effect of ultrasound. As novel methods, their applications were expanded and the analytical performance of spectrophotometric determination for copper was considerably improved. The influence factors of UA-CPE and UA-DLLME were studied in detail. Under the optimal conditions, the limits of detection (LODs) for copper were 0.7 μg L-1 of UA-CPE and 0.8 μg L-1 of UA-DLLME with sensitivity enhancement factors (EFs) of 17 and 16. The developed methods were applied to the determination of trace copper in real water samples with satisfactory analytical results.

  17. Effects of feeding elevated concentrations of copper and zinc on the antimicrobial susceptibilities of fecal bacteria in feedlot cattle.

    Science.gov (United States)

    Jacob, Megan E; Fox, J Trent; Nagaraja, T G; Drouillard, James S; Amachawadi, Raghavendra G; Narayanan, Sanjeev K

    2010-06-01

    Cattle are fed elevated concentrations of copper and zinc for growth promotion. The potential mechanisms of growth promotional effects of these elements are attributed to their antimicrobial activities, similar to that of antibiotics, in that gut microbial flora are altered to reduce fermentation loss of nutrients and to suppress gut pathogens. Copper and zinc fed at elevated concentrations may select for bacteria that are resistant not only to heavy metals but also to antibiotics. Our objectives were to determine the effects of feeding elevated copper and zinc on the antimicrobial susceptibilities of fecal bacteria in feedlot cattle. Twenty heifers, fed corn-based high-grain diets, were randomly assigned to treatments in a 2 x 2 factorial arrangement with 1X or 10X National Research Council recommended copper and/or zinc. Feces, collected on days 0, 14, and 32, were cultured for commensal bacteria (Escherichia coli and Enterococcus) to determine their susceptibilities to copper, zinc, and antibiotics. Fecal DNA was extracted to detect tcrB gene and quantify erm(B) and tet(M) genes. In E. coli and Enterococcus sp., minimal differences in minimum inhibitory concentrations (MICs) of copper, zinc, and antibiotics were noticed. The mean copper MIC for E. coli increased (p cattle had marginal effects on antimicrobial susceptibilities of fecal E. coli and enterococci.

  18. Relation between serum lipoperoxide concentrations and iron or copper status over one year in Cuban adult men

    Energy Technology Data Exchange (ETDEWEB)

    Arnaud, J.; Renversez, J.C.; Favier, A.E. [Dept. de Biologie Integree, CHUG, Grenoble (France); Fleites, P.; Perez-Cristia, R. [Centro national de Toxicologia (CENATOX), La Habana (Cuba); Chassagne, M.; Barnouin, J. [INRA, Unite d' Ecopathologie, Saint Genes Champanelle (France); Verdura, T. [Inst. Finlay, La Lisa, La Habana (Cuba); Garcia, I.G. [Inst. de Farmacia y Alimentos, La Coronela, La Lisa, Ciudad de la Habana (Cuba); Tressol, J.C. [INRA, Unite maladies metaboliques et micronutriments, Saint Genes Champanelle (France)

    2001-07-01

    The aims of this study were to determine the relations between iron and copper status and lipid peroxidation at different periods over one year in low-income and low-energy intake healthy subjects. The study was conducted in 199 middle-aged healthy Cuban men from March 1995 to February 1996. Iron status was assessed by the determination of serum ferritin, transferrin saturation, whole blood hemoglobin and iron intakes. Copper status was evaluated by the determination of serum copper and copper intakes. Serum thiobarbituric acid substances (TBARS) determination was used as an index of lipid peroxidation. Rank correlations were observed between serum TBARS concentrations and iron or copper status indices at different periods. In period 3 (end of the rainy season), serum TBARS and ferritin concentrations were maximum whereas blood hemoglobin levels and iron intake were minimum. Serum TBARS concentrations were significantly higher than the reference values of the laboratory whereas, iron and copper status were within the reference ranges. These results suggested that iron and copper status may be associated with lipid peroxidation in subjects without metal overloads and that variations over the year needed to be taken in account. (orig.)

  19. The scientific basis for a satellite mission to retrieve CCN concentrations and their impacts on convective clouds

    Directory of Open Access Journals (Sweden)

    D. Rosenfeld

    2012-02-01

    Full Text Available The cloud -mediated radiative forcing is widely recognized as the main source of uncertainty in our knowledge of the anthropogenic climate forcing and in our understanding of climate sensitivity. Current outstanding challenges are (1 global measurements of cloud condensation nuclei (CCN in the cloudy boundary layer from space, and, (2 disentangling the effects of aerosols from the thermodynamic and meteorological effects on the clouds. Here we present a new concept for a way to overcome these two challenges, using relatively simple passive satellite measurements in the visible and IR. The idea is to use the clouds themselves as natural CCN chambers by retrieving simultaneously the number of activated aerosols at cloud base, Na, and the cloud base updraft speed. The Na is obtained by analyzing the distribution of cloud drop effective radius in convective elements as a function distance above cloud base. The cloud base updraft velocities are estimated by double stereoscopic viewing and tracking of the evolution of cloud surface features just above cloud base. In order to resolve the vertical dimension of the clouds, the field of view will be 100 m for the microphysical retrievals, and 50 m for the stereoscopic measurements. The viewing geometry will be 30 degrees off nadir eastward, with the Sun in the back at 30 degrees off zenith westward, which requires a Sun synchronous orbit at 14:00 LST. Having measured simultaneously the thermodynamic environment, the vertical motions of the clouds, their microstructure and the CCN concentration will allow separating the dynamic from the CCN effects. This concept is being applied in the proposed satellite mission named Clouds, Hazards and Aerosols Survey for Earth Researchers (CHASER.

  20. The scientific basis for a satellite mission to retrieve CCN concentrations and their impacts on convective clouds

    Directory of Open Access Journals (Sweden)

    D. Rosenfeld

    2012-08-01

    Full Text Available The cloud-mediated aerosol radiative forcing is widely recognized as the main source of uncertainty in our knowledge of the anthropogenic forcing on climate. The current challenges for improving our understanding are (1 global measurements of cloud condensation nuclei (CCN in the cloudy boundary layer from space, and (2 disentangling the effects of aerosols from the thermodynamic and meteorological effects on the clouds. Here, we present a new conceptual framework to help us overcome these two challenges, using relatively simple passive satellite measurements in the visible and infared (IR. The idea is to use the clouds themselves as natural CCN chambers by retrieving simultaneously the number of activated aerosols at cloud base, Na, and the cloud base updraft speed. The Na is obtained by analyzing the distribution of cloud drop effective radius in convective elements as a function of distance above cloud base. The cloud base updraft velocities are estimated by double stereoscopic viewing and tracking of the evolution of cloud surface features just above cloud base. In order to resolve the vertical dimension of the clouds, the field of view will be 100 m for the microphysical retrievals, and 50 m for the stereoscopic measurements. The viewing geometry will be eastward and 30 degrees off nadir, with the Sun in the back at 30 degrees off zenith westward, requiring a Sun-synchronous orbit at 14 LST. Measuring simultaneously the thermodynamic environment, the vertical motions of the clouds, their microstructure and the CCN concentration will allow separating the dynamics from the CCN effects. This concept is being applied in the proposed satellite mission named Clouds, Hazards and Aerosols Survey for Earth Researchers (CHASER.

  1. Effects of High Salt Concentration and Residue on Copper and Aluminum Corrosion

    Institute of Scientific and Technical Information of China (English)

    HUO Ying; TAN Mike; Yong jun; SHU Li

    2013-01-01

    Traditional researches on metal corrosion under salt solutions deposit conditions are usually carried out by visual,electron microscopic observations and simple electrochemical measurement via a traditional one-piece electrode.These techniques have difficulties in measuring localized corrosion that frequently occur in inhomogeneous media.This paper reports the results from the experiments using specially shaped coupons and a relatively new method of measuring heterogeneous electrochemical processes,namely,the wire beam electrode(WBE).Preliminary results from copper and aluminum corrosion in highly concentrated sodium chloride solutions with and without solid deposits show that the method is useful in simulating and studying corrosion especially localized corrosion in pipelines.

  2. Effect of chromated copper arsenate structures on adjacent soil arsenic concentrations.

    Science.gov (United States)

    Patch, Steven C; Scheip, Katherine; Brooks, Billy

    2011-06-01

    Structures made of chromated copper arsenic (CCA) have been shown to leach arsenic into the surrounding soil. Soil cores were taken adjacent to six CCA decks at 0, 15, 60 and 300 cm from the deck at depths of 0-10, 10-20, and 20-30 cm, and were analyzed for soil arsenic concentrations. Median soil arsenic concentrations ranged from 1.8 μg/g at a depth of 10-20 cm and a distance of 300 cm to 34.5 μg/g at a depth of 0-10 cm and a distance of 30 cm. Soil arsenic concentrations taken at depths of 0-10 and 10-20 cm decreased as distance from the deck increased. Soil arsenic concentrations close to the deck were higher at lower soil depths and at homes with greater deck wipe arsenic concentrations. Age of deck and slope of land had significant effects on the differences in arsenic concentrations between samples taken at different distances when evaluated in models by themselves, but not in models adjusting for deck wipe concentrations. Size of deck and bulk density of soil did not have significant effects on soil arsenic concentrations.

  3. Effects of Nitrogen Concentration on Microstructure and Antibac-terial Property of Copper-Bearing Austenite Stainless Steels

    Institute of Scientific and Technical Information of China (English)

    Zhixia ZHANG; Laizhu JIANG; Gang LIN; Zhou XU

    2008-01-01

    Austenite antibacterial stainless steels have been found to have wide applications in hospitals and food indus-tries. In recent years epsilon copper precipitation in antibacterial stainless steels has obtained much research interest due to its antibacterial action. The objective of this study was to determine the effects of nitro-gen concentration on the precipitation of epsilon copper and antibacterial property. Two kinds of austenite antibacterial stainless steels containing copper and different nitrogen concentration (0.02 and 0.08 wt pct, re-spectively) were prepared and the microstructures were characterized by a combination of electron microscopy and thermodynamic analysis. A mathematical expression was deduced to predict the effect of nitrogen con-centration on the activity coefficient of copper, In(fCu/focu)=0.53524+4.11xN-0.48x2N. Higher nitrogen was found to increase the free energy difference of copper concentration distribution between precipitation phase and austenite matrix, stimulate the aggregation of copper atoms from austenite, increase the precipitation amount and consequently enhance the antibacterial property of steel.

  4. Toward a robust analytical method for separating trace levels of nano-materials in natural waters: cloud point extraction of nano-copper(II) oxide.

    Science.gov (United States)

    Majedi, Seyed Mohammad; Kelly, Barry C; Lee, Hian Kee

    2014-10-01

    Cloud point extraction (CPE) factors, namely Triton X-114 (TX-114) concentration, pH, ionic strength, incubation time, and temperature, were optimized for the separation of nano-sized copper(II) oxide (nCuO) in aqueous matrices. The kinetics of phase transfer was studied using UV-visible spectroscopy. From the highest separation rate, the most favorable conditions were observed with 0.2 % w/v of TX-114, pH = 9.0, ionic strength of 10 mM NaCl, and incubation at 40 °C for 60 min, yielding an extraction efficiency of 89.2 ± 3.9 % and a preconcentration factor of 86. The aggregate size distribution confirmed the formation of very large nCuO-micelle assemblies (11.9 μm) under these conditions. The surface charge of nCuO was also diminished effectively. An extraction efficiency of 91 % was achieved with a mixture of TX-100 and TX-114 containing 30 wt.% of TX-100. Natural organic and particulate matters, represented by humic acid (30 mg/L) and micron-sized silica particles (50 mg/L), respectively, did not significantly reduce the CPE efficiency (<10 %). The recovery of copper(II) ions (20 mg/L) in the presence of humic acid was low (3-10 %). The spiked natural water samples were analyzed either directly or after CPE by inductively coupled plasma mass spectrometry following acid digestion/microwave irradiation. The results indicated the influence of matrix effects and their reduction by CPE. A delay between spiking nCuO and CPE may also influence the recovery of nCuO due to aggregation and dissolution. A detection limit of 0.04 μg Cu/L was achieved for nCuO.

  5. Characterization of saturation and copper concentration in sand and clay with SIP measurements.

    Science.gov (United States)

    Peruzzo, L.; Schmutz, M.; Franceschi, M.; Hubbard, S. S.

    2016-12-01

    Adsorption by clay minerals, oxides and organic matter is commonly the most effective mechanism controlling the mobility and bioavailability of heavy metals in soil. As contamination processes of natural systems commonly present an important variability with time and space, we aim to show if non-invasive and imaging geophysical methods, specifically Spectral Induced Polarization (SIP), are sensitive to mobility and/or bioavailability of copper. Promising works have recently shown that SIP is sensitive to the different ions dissolved in soil water thanks to their different adsorption behavior. To the best of our knowledge, these works have used clean sand as medium; that is why we need to reach a more generic comprehension of natural soil by including the relevant adsorbents. In this paper, we focus on the copper SIP signature accounting for the presence of two types of clay (montmorillonite and kaolinite), different saturation levels and representative copper concentrations which have been chosen on the base of Cu chemical extractions from soil samples taken in a Cu polluted test site. During the set of SIP measurements one single variable at time is changed: soil components, saturation and solution Cu concentration. At the same time pH and temperature are monitored. A successive modeling will consist of two parts. 1) In order to correctly interpret the SIP measurements and make sure that the signals are only influenced by matrix and fluid composition, thanks to very recent publications, we will model the EM inductive coupling, the effect of the electrodes used and the Maxwell-Wagner effect. 2) Geochemical modeling characterizing the electrical double layer (EDL) state at the different experimental conditions; then we will try to theoretically link the EDL state to the SIP results. This last step could provide an important insight about the polarization mechanisms under the investigated conditions.

  6. Influences of in-cloud aerosol scavenging parameterizations on aerosol concentrations and wet deposition in ECHAM5-HAM

    Directory of Open Access Journals (Sweden)

    B. Croft

    2010-02-01

    Full Text Available A diagnostic cloud nucleation scavenging scheme, which determines stratiform cloud scavenging ratios for both aerosol mass and number distributions, based on cloud droplet, and ice crystal number concentrations, is introduced into the ECHAM5-HAM global climate model. This scheme is coupled with a size-dependent in-cloud impaction scavenging parameterization for both cloud droplet-aerosol, and ice crystal-aerosol collisions. The aerosol mass scavenged in stratiform clouds is found to be primarily (>90% scavenged by cloud nucleation processes for all aerosol species, except for dust (50%. The aerosol number scavenged is primarily (>90% attributed to impaction. 99% of this impaction scavenging occurs in clouds with temperatures less than 273 K. Sensitivity studies are presented, which compare aerosol concentrations, burdens, and deposition for a variety of in-cloud scavenging approaches: prescribed fractions, a more computationally expensive prognostic aerosol cloud processing treatment, and the new diagnostic scheme, also with modified assumptions about in-cloud impaction and nucleation scavenging. Our results show that while uncertainties in the representation of in-cloud scavenging processes can lead to differences in the range of 20–30% for the predicted annual, global mean aerosol mass burdens, and near to 50% for accumulation mode aerosol number burden, the differences in predicted aerosol mass concentrations can be up to one order of magnitude, particularly for regions of the middle troposphere with temperatures below 273 K where mixed and ice phase clouds exist. Different parameterizations for impaction scavenging changed the predicted global, annual mean number removal attributed to ice clouds by seven-fold, and the global, annual dust mass removal attributed to impaction by two orders of magnitude. Closer agreement with observations of black carbon profiles from aircraft (increases near to one order of magnitude for mixed phase clouds

  7. Concentration dependent toxicokinetics of copper in the red flour beetle Tribolium castaneum (Coleoptera: Tenebrionidae).

    Science.gov (United States)

    Bednarska, Agnieszka J; Stępień, Katarzyna

    2015-11-01

    To predict internal metal concentrations in animals under specific environmental exposures, the relationship between the exposure concentrations and values of toxicokinetic parameters must be known. At high exposure levels, the availability of carriers transporting metal ions through cellular membranes may become limited, thereby decreasing the assimilation rates (k A ). Furthermore, increased metal concentrations in food may result in greater damage to the gut and reduce the assimilation efficiency and/or increase the elimination rate (k E ). Therefore, k A should decrease and k E should increase with increasing metal concentrations. In fact, our study on Tribolium castaneum exposed to Cu at 500, 1000, 2000 and 4000 mg kg(-1) of dry flour showed that with increasing Cu concentrations, k A decreased from 0.0042 day(-1) at 500 mg kg(-1) to 0.0026 day(-1) at 4000 mg kg(-1) in females and from 0.0029 to 0.001 day(-1) in males and k E increased from 0.027 to 0.064 day(-1) and from 0.018 to 0.04 day(-1) in females and males, respectively. Significant differences in k A between the sexes were observed at 2000 and 4000 mg kg(-1), whereas significant differences between treatments were found for k A in males. Copper was efficiently regulated by T. castaneum: an eightfold increase in exposure concentrations resulted in only a ca. twofold increase in the internal concentration. No Cu effect on the respiratory metabolism of T. castaneum was found.

  8. Secondary poisoning of cadmium, copper and mercury: implications for the Maximum Permissible Concentrations and Negligible Concentrations in water, sediment and soil

    NARCIS (Netherlands)

    Smit CE; Wezel AP van; Jager T; Traas TP; CSR

    2000-01-01

    The impact of secondary poisoning on the Maximum Permissible Concentrations (MPCs) and Negligible Concentrations (NCs) of cadmium, copper and mercury in water, sediment and soil have been evaluated. Field data on accumulation of these elements by fish, mussels and earthworms were used to derive MPC

  9. Secondary poisoning of cadmium, copper and mercury: implications for the Maximum Permissible Concentrations and Negligible Concentrations in water, sediment and soil

    NARCIS (Netherlands)

    Smit CE; Wezel AP van; Jager T; Traas TP; CSR

    2000-01-01

    The impact of secondary poisoning on the Maximum Permissible Concentrations (MPCs) and Negligible Concentrations (NCs) of cadmium, copper and mercury in water, sediment and soil have been evaluated. Field data on accumulation of these elements by fish, mussels and earthworms were used to derive

  10. Dependence Properties of Sol-Gel Derived CuO@SiO2 Nanostructure to Diverse Concentrations of Copper Oxide

    Directory of Open Access Journals (Sweden)

    V. Homaunmir

    2013-01-01

    Full Text Available Various concentrations of copper oxide were embedded into silica matrix of xerogel forms using copper source Cu(NO32·3H2O. The xerogel samples were prepared by hydrolysis and condensation of tetraethyl orthosilicate (TEOS with determination of new molar ratios of the components by the sol-gel method. In this paper, three samples of copper oxide were doped into silica matrices using different concentrations. We obtained 10, 20, and 30 wt.% of copper oxide in silica matrices labeled as A, B, and C, respectively. The absorption and transmittance spectra of the gel matrices were treated at different concentrations by Uv-vis spectrophotometer. Quantities of water and transparency in the silica network change the spectral characteristics of Cu2+ ions in the host silica. Absorption spectra of the samples heated to higher concentration complete the conversion of Cu2+ ions to Cu+ ions. The effects of concentration of copper oxide were characterized by X-ray diffraction (XRD patterns, and the transmission electron microscope (TEM micrographs. Also, textural properties of samples were studied by surface area analysis (BET method at different concentrations.

  11. A new dispersive liquid-liquid microextraction using ionic liquid based microemulsion coupled with cloud point extraction for determination of copper in serum and water samples.

    Science.gov (United States)

    Arain, Salma Aslam; Kazi, Tasneem Gul; Afridi, Hassan Imran; Arain, Mariam Shahzadi; Panhwar, Abdul Haleem; Khan, Naeemullah; Baig, Jameel Ahmed; Shah, Faheem

    2016-04-01

    A simple and rapid dispersive liquid-liquid microextraction procedure based on ionic liquid assisted microemulsion (IL-µE-DLLME) combined with cloud point extraction has been developed for preconcentration copper (Cu(2+)) in drinking water and serum samples of adolescent female hepatitits C (HCV) patients. In this method a ternary system was developed to form microemulsion (µE) by phase inversion method (PIM), using ionic liquid, 1-butyl-3-methylimidazolium hexafluorophosphate ([C4mim][PF6]) and nonionic surfactant, TX-100 (as a stabilizer in aqueous media). The Ionic liquid microemulsion (IL-µE) was evaluated through visual assessment, optical light microscope and spectrophotometrically. The Cu(2+) in real water and aqueous acid digested serum samples were complexed with 8-hydroxyquinoline (oxine) and extracted into IL-µE medium. The phase separation of stable IL-µE was carried out by the micellar cloud point extraction approach. The influence of of different parameters such as pH, oxine concentration, centrifugation time and rate were investigated. At optimized experimental conditions, the limit of detection and enhancement factor were found to be 0.132 µg/L and 70 respectively, with relative standard deviation <5%. In order to validate the developed method, certified reference materials (SLRS-4 Riverine water) and human serum (Sero-M10181) were analyzed. The resulting data indicated a non-significant difference in obtained and certified values of Cu(2+). The developed procedure was successfully applied for the preconcentration and determination of trace levels of Cu(2+) in environmental and biological samples.

  12. Separation of copper flotation concentrates into density fractions by means of polytungstate aqueous solution

    Directory of Open Access Journals (Sweden)

    Luszczkiewicz Andrzej

    2016-01-01

    Full Text Available Industrial and laboratory flotation copper concentrates were subjected to separation into density fractions by means of heavy liquids in the form of sodium polytungstate aqueous solutions. For two samples, three densities factions were created, however in different density ranges. The density fractions were analyzed to establish the content of copper, lead, silver and organic carbon. The size of particles in both samples was similar (90-95% −0.071 mm. It was found that the lightest density fractions −2.45 and −2.0 g/cm3 still contained sulfide minerals scattered in the organic carbon bearing particles. Removal of the lightest density fraction (−2.0 g/cm3 from the industrial concentrate samples led to considerable reduction of organic carbon (92% and increasing its quality from 13 to 28% Cu. The mineralogical analysis of the heavy liquid separation products showed that most sulfide minerals were evenly dissemination in the heaviest density fractions with the recovery of 95-98%. The lightest density fraction of −2.0 g/cm3, being the richest in organic carbon, contained approximately 3% of unliberated sulfide minerals.

  13. Copper concentration in body tissues and fluids in normal subjects of southern Poland.

    Science.gov (United States)

    Lech, T; Sadlik, J K

    2007-07-01

    Data on the concentration of the elements in the human body are important, for example, to estimate the amounts required to maintain a good healthy state or find their connections with morbidity and mortality. In this paper, the concentration of copper (by flame atomic absorption spectrometry) in material obtained from autopsy cases of nonpoisoned people (n = 130), aged from 14 to 80 years, between 1990-2006, is presented. The following values were found (mean +/- SD in micrograms of copper per gram or per milliliter): brain 3.32 +/- 1.50 (n = 43), liver 3.47 +/- 1.51 (n = 79), kidney 2.15 +/- 0.90 (n = 76), stomach 1.10 +/- 0.76 (n = 65), intestines 1.54 +/- 1.19 (n = 25), lung 1.91 +/- 1.30 (n = 27), spleen 1.23 +/- 0.28 (n = 3), heart 3.26 +/- 0.59 (n = 5), bile 3.60 +/- 1.67 (n = 13), and blood 0.85 +/- 0.19 (n = 73).

  14. Influence of a High-Pressure Comminution Technology on Concentrate Yields in Copper Ore Flotation Processes

    Directory of Open Access Journals (Sweden)

    Saramak D.

    2014-10-01

    Full Text Available The article concerns the issues of flotation process effectiveness in relationship to the operating conditions of a high-pressure comminution process course. Experimental programme covering a flotation laboratory batch tests was a verification technique of a high-pressure crushing operations course. The most favorable values of flotation concentrate weight recoveries were obtained for the pressing force 6 kN and 4% of the feed moisture. It was also determined the model of the concentrate weight recovery as a function of pressing force in the press and feed moisture content. This model was the basis for the optimization of effects of copper ore flotation processes preceded in high-pressure crushing operation in roller presses.

  15. Dopant Concentration and Effective Atomic Number of Copper-Doped Potassium Borate Glasses

    Directory of Open Access Journals (Sweden)

    I. Hossain

    2013-01-01

    Full Text Available Copper-doped (0.5 mol% and undoped potassium borate glasses have been prepared by the composition of (100-xH3BO3 + xK2CO3, where 10 ≤ x ≤ 30 mol % by the traditional melting quenching method. The structural pattern of glasses with different composition has been identified by X-ray diffraction (XRD. The glow curves were analysed to determine various characterizations of the TLDs. Identification of the compositions and concentrations and effective atomic number of undoped and doped potassium borate glass was carried out using scanning electron microscope analysis (SEM. The dopant concentrations are found to be 0.25 mol%, while Zeff are 11.42 and 10.48 for Cu-doped and undoped potassium borate glasses, respectively.

  16. AGNES at vibrated gold microwire electrode for the direct quantification of free copper concentrations.

    Science.gov (United States)

    Domingos, Rute F; Carreira, Sara; Galceran, Josep; Salaün, Pascal; Pinheiro, José P

    2016-05-12

    The free metal ion concentration and the dynamic features of the metal species are recognized as key to predict metal bioavailability and toxicity to aquatic organisms. Quantification of the former is, however, still challenging. In this paper, it is shown for the first time that the concentration of free copper (Cu(2+)) can be quantified by applying AGNES (Absence of Gradients and Nernstian equilibrium stripping) at a solid gold electrode. It was found that: i) the amount of deposited Cu follows a Nernstian relationship with the applied deposition potential, and ii) the stripping signal is linearly related with the free metal ion concentration. The performance of AGNES at the vibrating gold microwire electrode (VGME) was assessed for two labile systems: Cu-malonic acid and Cu-iminodiacetic acid at ionic strength 0.01 M and a range of pH values from 4.0 to 6.0. The free Cu concentrations and conditional stability constants obtained by AGNES were in good agreement with stripping scanned voltammetry and thermodynamic theoretical predictions obtained by Visual MinteQ. This work highlights the suitability of gold electrodes for the quantification of free metal ion concentrations by AGNES. It also strongly suggests that other solid electrodes may be well appropriate for such task. This new application of AGNES is a first step towards a range of applications for a number of metals in speciation, toxicological and environmental studies for the direct determination of the key parameter that is the free metal ion concentration.

  17. Juvenile life stages of the brown alga Fucus serratus L. are more sensitive to combined stress from high copper concentration and temperature than adults

    DEFF Research Database (Denmark)

    Nielsen, Søren Laurentius; Nielsen, Hanne Dalsgaard; Pedersen, Morten Foldager

    2014-01-01

    The combined effects of exposure to copper and temperature were investigated in adult specimens and germlings of the canopy-forming brown alga Fucus serratus. A matrix of four temperatures, 6, 12, 17 and 22 °C, and three concentrations of copper, 0, 100 and 1,000 nM total copper were used. Measured...

  18. Near-Unity Emitting Copper-Doped Colloidal Semiconductor Quantum Wells for Luminescent Solar Concentrators.

    Science.gov (United States)

    Sharma, Manoj; Gungor, Kivanc; Yeltik, Aydan; Olutas, Murat; Guzelturk, Burak; Kelestemur, Yusuf; Erdem, Talha; Delikanli, Savas; McBride, James R; Demir, Hilmi Volkan

    2017-08-01

    Doping of bulk semiconductors has revealed widespread success in optoelectronic applications. In the past few decades, substantial effort has been engaged for doping at the nanoscale. Recently, doped colloidal quantum dots (CQDs) have been demonstrated to be promising materials for luminescent solar concentrators (LSCs) as they can be engineered for providing highly tunable and Stokes-shifted emission in the solar spectrum. However, existing doped CQDs that are aimed for full solar spectrum LSCs suffer from moderately low quantum efficiency, intrinsically small absorption cross-section, and gradually increasing absorption profiles coinciding with the emission spectrum, which together fundamentally limit their effective usage. Here, the authors show the first account of copper doping into atomically flat colloidal quantum wells (CQWs). In addition to Stokes-shifted and tunable dopant-induced photoluminescence emission, the copper doping into CQWs enables near-unity quantum efficiencies (up to ≈97%), accompanied by substantially high absorption cross-section and inherently step-like absorption profile, compared to those of the doped CQDs. Based on these exceptional properties, the authors have demonstrated by both experimental analysis and numerical modeling that these newly synthesized doped CQWs are excellent candidates for LSCs. These findings may open new directions for deployment of doped CQWs in LSCs for advanced solar light harvesting technologies. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Clinical Factors Associated With Serum Copper Concentration In Patients On Hemodialysis

    Directory of Open Access Journals (Sweden)

    Ryota Ikee

    2012-06-01

    We showed significant association of serum copper levels with inflammation and oxidative stress in HD patients. Further studies are required to investigate whether sevelamer may improve serum copper levels, inflammation, and oxidative stress.

  20. The Role of Initial Cloud Condensation Nuclei Concentration in Hail Using the WRF NSSL 2-moment Microphysics Scheme

    Science.gov (United States)

    Li, Xiaofei; Zhang, Qinghong; Xue, Huiwen

    2017-04-01

    The effects of the initial cloud condensation nuclei (CCN) concentrations (100-3000 mg-1) on hail properties were investigated in an idealized hail storm experiment using the Weather Research and Forecasting (WRF) model, with the National Severe Storms Laboratory two-moment microphysics scheme. The initial CCN concentration had obvious non-monotonic effects on the mixing ratio, number concentrations, and radius of hail, both in clouds and at the surface, with a threshold CCN concentration between 300 and 500 mg-1. An increasing CCN concentration is conducive (suppressive) to the amount of surface hail precipitation below (above) the threshold. The non-monotonic effects were due to both the thermodynamics and microphysics. Below the threshold, the mixing ratios of cloud droplets and ice crystals increased dramatically with the increasing CCN concentration, resulting in more latent heat being released from vapor condensation and intensified updraft volume. The extent of the riming process, which is the primary process for hail production, increased dramatically. Above the threshold, the mixing ratio of cloud droplets and ice crystals increased continuously, but the maximum updraft volume was weakened because of reduced latent heating, which was related to the reduced riming rate in the storm core area. The smaller ice crystals reduced the formation of hail and smaller clouds, with decreased rain water reducing riming efficiency so that graupel and hail also decreased with increasing CCN concentration, which is unfavorable for hail growth.

  1. Effects of dietary selenium, sulphur and copper levels on selenium concentration in the serum and liver of lamb.

    Science.gov (United States)

    Netto, Arlindo Saran; Zanetti, Marcus Antonio; Correa, Lisia Bertonha; Del Claro, Gustavo Ribeiro; Salles, Márcia Saladini Vieira; Vilela, Flávio Garcia

    2014-08-01

    Thirty-two lambs were distributed in eight treatments under 2×2×2 factorial experiment to compare the effects of two levels of selenium (0.2 to 5 mg/kg dry matter [DM]), sulphur (0.25% and 0.37%) and copper (8 and 25 mg/kg DM) levels on selenium concentration in liver and serum of lambs. A liver biopsy was done on all animals and blood samples were collected from the jugular vein prior to the beginning of the treatments. The blood was sampled every thirty days and the liver was sampled after 90 days, at the slaughter. Increasing differences were noticed during the data collection period for the serum selenium concentration, and it was found to be 0.667 mg/L in animals fed with 5 mg Se/kg DM and normal sulphur and copper concentrations in their diet. However, a three-way interaction and a reduction of selenium concentration to 0.483 mg/L was verified when increasing copper and sulphur concentration levels to 25 ppm and 0.37% respectively. The liver selenium concentration was also high for diets containing higher selenium concentrations, but the antagonist effect with the increased copper and sulphur levels remained, due to interactions between these minerals. Therefore, for regions where selenium is scarce, increasing its concentration in animal diets can be an interesting option. For regions with higher levels of selenium, the antagonistic effect of interaction between these three minerals should be used by increasing copper and sulphur dietary concentrations, thus preventing possible selenium poisoning.

  2. Effects of Dietary Selenium, Sulphur and Copper Levels on Selenium Concentration in the Serum and Liver of Lamb

    Science.gov (United States)

    Netto, Arlindo Saran; Zanetti, Marcus Antonio; Correa, Lisia Bertonha; Del Claro, Gustavo Ribeiro; Salles, Márcia Saladini Vieira; Vilela, Flávio Garcia

    2014-01-01

    Thirty-two lambs were distributed in eight treatments under 2×2×2 factorial experiment to compare the effects of two levels of selenium (0.2 to 5 mg/kg dry matter [DM]), sulphur (0.25% and 0.37%) and copper (8 and 25 mg/kg DM) levels on selenium concentration in liver and serum of lambs. A liver biopsy was done on all animals and blood samples were collected from the jugular vein prior to the beginning of the treatments. The blood was sampled every thirty days and the liver was sampled after 90 days, at the slaughter. Increasing differences were noticed during the data collection period for the serum selenium concentration, and it was found to be 0.667 mg/L in animals fed with 5 mg Se/kg DM and normal sulphur and copper concentrations in their diet. However, a three-way interaction and a reduction of selenium concentration to 0.483 mg/L was verified when increasing copper and sulphur concentration levels to 25 ppm and 0.37% respectively. The liver selenium concentration was also high for diets containing higher selenium concentrations, but the antagonist effect with the increased copper and sulphur levels remained, due to interactions between these minerals. Therefore, for regions where selenium is scarce, increasing its concentration in animal diets can be an interesting option. For regions with higher levels of selenium, the antagonistic effect of interaction between these three minerals should be used by increasing copper and sulphur dietary concentrations, thus preventing possible selenium poisoning. PMID:25083101

  3. AGNES at vibrated gold microwire electrode for the direct quantification of free copper concentrations

    Energy Technology Data Exchange (ETDEWEB)

    Domingos, Rute F., E-mail: rdomingos@ipgp.fr [Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, Torre Sul Lab 11-6.3, Av. Rovisco Pais #1, 1049-001 Lisbon (Portugal); Carreira, Sara [Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, Torre Sul Lab 11-6.3, Av. Rovisco Pais #1, 1049-001 Lisbon (Portugal); Galceran, Josep [Department of Chemistry, University of Lleida and Agrotecnio, Rovira Roure 191, 25198 Lleida (Spain); Salaün, Pascal [School of Environmental Sciences, University of Liverpool, 4 Brownlow Street, Liverpool L693 GP (United Kingdom); Pinheiro, José P. [LIEC/ENSG, UMR 7360 CNRS – Université de Lorraine, 15 Avenue du Charmois, 54500 Vandoeuvre-les-Nancy (France)

    2016-05-12

    The free metal ion concentration and the dynamic features of the metal species are recognized as key to predict metal bioavailability and toxicity to aquatic organisms. Quantification of the former is, however, still challenging. In this paper, it is shown for the first time that the concentration of free copper (Cu{sup 2+}) can be quantified by applying AGNES (Absence of Gradients and Nernstian equilibrium stripping) at a solid gold electrode. It was found that: i) the amount of deposited Cu follows a Nernstian relationship with the applied deposition potential, and ii) the stripping signal is linearly related with the free metal ion concentration. The performance of AGNES at the vibrating gold microwire electrode (VGME) was assessed for two labile systems: Cu-malonic acid and Cu-iminodiacetic acid at ionic strength 0.01 M and a range of pH values from 4.0 to 6.0. The free Cu concentrations and conditional stability constants obtained by AGNES were in good agreement with stripping scanned voltammetry and thermodynamic theoretical predictions obtained by Visual MinteQ. This work highlights the suitability of gold electrodes for the quantification of free metal ion concentrations by AGNES. It also strongly suggests that other solid electrodes may be well appropriate for such task. This new application of AGNES is a first step towards a range of applications for a number of metals in speciation, toxicological and environmental studies for the direct determination of the key parameter that is the free metal ion concentration. - Highlights: • AGNES principles are valid at the vibrating gold microwire electrode (VGME). • VGME was successfully employed to quantify free Cu concentrations by using AGNES. • Stability constants of labile systems were in good agreement with predictions.

  4. Low concentrations of copper in drinking water increase AP-1 binding in the brain.

    Science.gov (United States)

    Lung, Shyang; Li, Huihui; Bondy, Stephen C; Campbell, Arezoo

    2015-12-01

    Copper (Cu) in trace amounts is essential for biological organisms. However, dysregulation of the redox-active metal has been implicated in different neurological disorders such as Wilson's, Menkes', Alzheimer's, and Parkinson's diseases. Since many households use Cu tubing in the plumbing system, and corrosion causes the metal to leach into the drinking water, there may be adverse effects on the central nervous system connected with low-level chronic exposure. The present study demonstrates that treatment with a biologically relevant concentration of Cu for 3 months significantly increases activation of the redox-modulated transcription factor AP-1 in mouse brains. This was independent of an upstream kinase indicated in AP-1 activation. Another redox-active transcription factor, NF-κB, was not significantly modified by the Cu exposure. These results indicate that the effect of Cu on AP-1 is unique and may involve direct modulation of DNA binding.

  5. Dependency of the band gap of electrodeposited Copper oxide thin films on the concentration of copper sulfate (CuSO4.5H2O) and pH in bath solution for photovoltaic applications

    KAUST Repository

    Islam, Md. Anisul

    2016-03-10

    In this study, Copper oxide thin films were deposited on copper plate by electrodeposition process in an electrolytic bath containing CuSO4.5H2O, 3M lactic acid and NaOH. Copper oxide films were electrodeposited at different pH and different concentration of CuSO4.5H2O and the optical band gap was determined from their absorption spectrum which was obtained from UV-Vis absorption spectroscopy. It was found that copper oxide films which were deposited at low concentration of CuSO4.5H2O have higher band gap than those deposited at higher bath concentration. The band gap of copper oxide films also significantly changes with pH of the bath solution. It was also observed that with the increase of the pH of bath solution band gap of copper oxide film decreased. © 2015 IEEE.

  6. Copper and zinc concentrations in atherosclerotic plaque and serum in relation to lipid metabolism in patients with carotid atherosclerosis

    Directory of Open Access Journals (Sweden)

    Tasić Nebojša M.

    2015-01-01

    Full Text Available Background/Aim. Some oligoelements are now investigated as possibly having a role in atherosclerosis. The aim of this study was to compare the concentrations of copper and zinc in the serum and carotid plaque and parameters of lipid metabolism in patients with different morphology of carotid atherosclerotic plaque. Methods. Carotid endarterectomy due to the significant atherosclerotic stenosis was performed in 91 patients (mean age 64 ± 7. The control group consisted of 27 patients (mean age 58 ± 9, without carotid atherosclerosis. Atheroscletoric plaques were divided into four morphological groups, according to ultrasonic and intraoperative characteristics. Copper and zinc concentrations in the plaque, carotid artery and serum were measured by atomic absorption spectrophotometry. Results. Serum copper concentrations were statistically significantly higher in the patients with hemorrhagic in comparison to those with calcified plaque (1.2 ± 0.9 μmol/L vs 0.7 ± 0.2 μmol/L, respectively; p = 0.021. Zinc concentrations were statistically significantly lower in plaques of the patients with fibrolipid in comparison to those with calcified plaques (22.1 ± 16.3 μg/g vs 38.4 ± 25.8 μg/g, respectively; p = 0.024. A negative significant correlation was found for zinc and triglycerides in the serum in all the patients (r = -0.52, p = 0.025. In the control group we also demonstrated a positive significant correlation for low-density lipoprotein cholesterol and copper in the serum (r = 0.54, p = 0.04. Conclusion. The data obtained in the current study are consistent with the hypothesis that high copper and lower zinc levels may contribute to atherosclerosis and its sequelae as factors in a multifactorial disease. Further studies are necessary in order to conclude whether high concentration of copper and zinc in the serum could be risk factors for atherosclesrosis.

  7. Aircraft observations and model simulations of concentration and particle size distribution in the Eyjafjallajökull volcanic ash cloud

    OpenAIRE

    Dacre, H. F.; A. L. M. Grant; Johnson, B. T.

    2013-01-01

    The Eyjafjallajökull volcano in Iceland emitted a cloud of ash into the atmosphere during April and May 2010. Over the UK the ash cloud was observed by the FAAM BAe-146 Atmospheric Research Aircraft which was equipped with in-situ probes measuring the concentration of volcanic ash carried by particles of varying sizes. The UK Met Office Numerical Atmospheric-dispersion Modelling Environment (NAME) has been used to simulate the evolution of the ash cloud emitted by the Eyjafjallajökull volcano...

  8. Aircraft observations and model simulations of concentration and particle size distribution in the Eyjafjallajökull volcanic ash cloud

    OpenAIRE

    Dacre, H. F.; A. L. M. Grant; Johnson, B. T.

    2012-01-01

    The Eyjafjallajökull volcano in Iceland emitted a cloud of ash into the atmosphere during April and May 2010. Over the UK the ash cloud was observed by the FAAM BAe-146 Atmospheric Research Aircraft which was equipped with in-situ probes measuring the concentration of volcanic ash carried by particles of varying sizes. The UK Met Office Numerical Atmospheric-dispersion Modelling Environment (NAME) has been used to simulate the evolution of the ash cloud emitted by the Eyjafjallajökull volcano...

  9. An Abandoned Copper Mining Site in Cyprus and Assessment of Metal Concentrations in Plants and Soil.

    Science.gov (United States)

    Baycu, G; Tolunay, D; Ozden, H; Csatari, I; Karadag, S; Agba, T; Rognes, S E

    2015-01-01

    Mining is an important source of metal pollution in the environment and abandoned mines are extremely restricted habitats for plants. Some plant species growing on metalliferous soils around mine tailings and spoil-heaps are metal-tolerant and accumulate high concentrations of metals. In this investigation, we aimed to perform a research in the CMC-abandoned copper mining area in Lefke-North Cyprus to assess the recent metal pollution in soil and plant systems. We collected 16 soil samples and 25 plant species from 8 localities around the vicinity of tailing ponds. Some concentrations of metals in soil samples varied from 185 to 1023 mg kg(-1) Cu, 15.2 to 59.2 mg kg(-1) Ni, 2.3 to 73.6 mg kg(-1) Cd and metals for plants ranged from 0.135 to 283 mg kg(-1) Cu, 0.26 to 31.2 mg kg(-1) Ni, 0.143 to 277 mg kg(-1) Cd. Atriplex semibaccata, Acacia cyanophylla, Erodium spp., Inula viscosa, Juncus sp., Oxalis pes-caprea, Pistacia lentiscus, Senecio vulgaris and Tragopogon sinuatus accumulated higher concentrations. BCF for Atriplex semibaccata was found very high, for this reason this plant can tentatively be considered as a hyperaccumulator of Cu and Cd, but it needs further investigation for its potential in phytoremediation.

  10. The relationship between aerosol and cloud drop number concentrations in a global aerosol microphysics model

    Directory of Open Access Journals (Sweden)

    K. J. Pringle

    2009-01-01

    Full Text Available Empirical relationships that link cloud droplet number (CDN to aerosol number or mass are commonly used to calculate global fields of CDN for climate forcing assessments. In this work we use a sectional global model of sulfate and sea-salt aerosol coupled to a mechanistic aerosol activation scheme to explore the limitations of this approach. We find that a given aerosol number concentration produces a wide range of CDN concentrations due to variations in the shape of the aerosol size distribution. On a global scale, the dependence of CDN on the size distribution results in regional biases in predicted CDN (for a given aerosol number. Empirical relationships between aerosol number and CDN are often derived from regional data but applied to the entire globe. In an analogous process, we derive regional "correlation-relations" between aerosol number and CDN and apply these regional relations to calculations of CDN on the global scale. The global mean percentage error in CDN caused by using regionally derived CDN-aerosol relations is 20 to 26%, which is about half the global mean percentage change in CDN caused by doubling the updraft velocity. However, the error is as much as 25–75% in the Southern Ocean, the Arctic and regions of persistent stratocumulus when an aerosol-CDN correlation relation from the North Atlantic is used. These regions produce much higher CDN concentrations (for a given aerosol number than predicted by the globally uniform empirical relations. CDN-aerosol number relations from different regions also show very different sensitivity to changing aerosol. The magnitude of the rate of change of CDN with particle number, a measure of the aerosol efficacy, varies by a factor 4. CDN in cloud processed regions of persistent stratocumulus is particularly sensitive to changing aerosol number. It is therefore likely that the indirect effect will be underestimated in these important regions.

  11. The relationship between aerosol and cloud drop number concentrations in a global aerosol microphysics model

    Directory of Open Access Journals (Sweden)

    K. J. Pringle

    2009-06-01

    Full Text Available Empirical relationships that link cloud droplet number (CDN to aerosol number or mass are commonly used to calculate global fields of CDN for climate forcing assessments. In this work we use a sectional global model of sulfate and sea-salt aerosol coupled to a mechanistic aerosol activation scheme to explore the limitations of this approach. We find that a given aerosol number concentration produces a wide range of CDN concentrations due to variations in the shape of the aerosol size distribution. On a global scale, the dependence of CDN on the size distribution results in regional biases in predicted CDN (for a given aerosol number. Empirical relationships between aerosol number and CDN are often derived from regional data but applied to the entire globe. In an analogous process, we derive regional "correlation-relations" between aerosol number and CDN and apply these regional relations to calculations of CDN on the global scale. The global mean percentage error in CDN caused by using regionally derived CDN-aerosol relations is 20 to 26%, which is about half the global mean percentage change in CDN caused by doubling the updraft velocity. However, the error is as much as 25–75% in the Southern Ocean, the Arctic and regions of persistent stratocumulus when an aerosol-CDN correlation relation from the North Atlantic is used. These regions produce much higher CDN concentrations (for a given aerosol number than predicted by the globally uniform empirical relations. CDN-aerosol number relations from different regions also show very different sensitivity to changing aerosol. The magnitude of the rate of change of CDN with particle number, a measure of the aerosol efficacy, varies by a factor 4. CDN in cloud processed regions of persistent stratocumulus is particularly sensitive to changing aerosol number. It is therefore likely that the indirect effect will be underestimated in these important regions.

  12. Sensitivity of aerosol concentrations and cloud properties to nucleation and secondary organic distribution in ECHAM5-HAM global circulation model

    Directory of Open Access Journals (Sweden)

    R. Makkonen

    2008-06-01

    Full Text Available The global aerosol-climate model ECHAM5-HAM was modified to improve the representation of new particle formation in the boundary layer. Activation-type nucleation mechanism was introduced to produce observed nucleation rates in lower troposphere. A simple and computationally efficient model for biogenic secondary organic aerosol (BSOA formation was implemented. We studied the sensitivity of aerosol and cloud droplet number concentrations (CDNC to these additions. Activation-type nucleation significantly increases aerosol number concentrations in the boundary layer. Increased particle number concentrations have a significant effect also on cloud droplet number concentrations and therefore on cloud properties. We performed calculations with activation nucleation coefficient values of 2×10-7 s−1, 2×10-6 s-1 and 2×10-5 s−1 to evaluate the sensitivity to this parameter. For BSOA we have used yields of 0.025, 0.07 and 0.15 to estimate the amount of monoterpene oxidation products available for condensation. The dynamic SOA scheme induces large regional changes to size distribution of organic carbon, and therefore affects particle optical properties and cloud droplet number concentrations locally. Comparison with satellite observation shows that activation-type nucleation significantly decreases the differences between observed and modeled values of cloud top CDNC.

  13. The relationship between bone health and plasma zinc, copper lead and cadmium concentration in osteoporotic women.

    Science.gov (United States)

    Sadeghi, Naficeh; Oveisi, Mohammad Reza; Jannat, Behrooz; Hajimahmoodi, Mannan; Behzad, Masoomeh; Behfar, Abdolazim; Sadeghi, Fatemeh; Saadatmand, Sahereh

    2014-01-01

    Osteoporosis is a multi factorial disease with dimension of genetic and nutritional considerations. The aim of this study was to present data from the association of plasma zinc, copper and toxic elements of lead and cadmium levels with bone mineral density in Iranian women. 135 women gave their information and enrolled. Fasting plasma was used for measurement of trace elements and heavy metals by Differential Pulse Anodic Stripping Voltammetry. Control group (n = 51) were normal in both lumbar spine (L1-L4) and femoral neck density (T-score ≥ -1), but just femoral neck T-score was considered as criterion in selection of patient group (n = 49, Tscore T-score > -1.7), 1.463 ± 0.174, 1.327 ± 0.147 μg/ml in Severe patient group (T-score < -1.7); respectively. Mean ± SD plasma level of lead and cadmium was 168.42 ± 9.61 ng/l, 2.91 ± 0.18 ng/ml in control group, 176.13 ± 8.64 ng/l, 2.97 ± 0.21 ng/ml in TP, 176.43 ± 13.2 ng/l, 2.99 ± 0.1 ng/ml in mild patients, 221.44 ± 20 ng/l and 3.80 ± 0.70 ng/ml in severe patient group, respectively. In this study plasma zinc, copper, lead & cadmium concentrations were higher in the patients than in the control, though differences were not significant. However, differences were higher between the controls and patients with severe disease (T-score < -1.7). In addition adjusted T-score of femur with age and BMI showed negative significant correlation with plasma levels of zinc and lead in total participants (p < 0.05, r = -0.201, p = 0.044, r = -0.201). It seems that more extensive study with larger ample size might supply definite results about this association for copper and cadmium.

  14. Simultaneous preconcentration of copper, zinc, cadmium, and nickel in water samples by cloud point extraction using 4-(2-pyridylazo)-resorcinol and their determination by inductively coupled plasma optic emission spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Edson Luiz, E-mail: edsonqmc@hotmail.com [Centro de Energia Nuclear na Agricultura, Universidade de Sao Paulo, Av. Centenario, 303, CP 96, 13416-000 Piracicaba, SP (Brazil); Santos Roldan, Paulo dos [Universidade Federal de Alagoas, Campus A.C. Simoes, Av. Lourival Melo Mota, Tabuleiro do Martins, CEP: 57072-970 AL (Brazil); Gine, Maria Fernanda [Centro de Energia Nuclear na Agricultura, Universidade de Sao Paulo, Av. Centenario, 303, CP 96, 13416-000 Piracicaba, SP (Brazil)

    2009-11-15

    A procedure for simultaneous separation/preconcentration of copper, zinc, cadmium, and nickel in water samples, based on cloud point extraction (CPE) as a prior step to their determination by inductively coupled plasma optic emission spectrometry (ICP-OES), has been developed. The analytes reacted with 4-(2-pyridylazo)-resorcinol (PAR) at pH 5 to form hydrophobic chelates, which were separated and preconcentrated in a surfactant-rich phase of octylphenoxypolyethoxyethanol (Triton X-114). The parameters affecting the extraction efficiency of the proposed method, such as sample pH, complexing agent concentration, buffer amount, surfactant concentration, temperature, kinetics of complexation reaction, and incubation time were optimized and their respective values were 5, 0.6 mmol L{sup -1}, 0.3 mL, 0.15% (w/v), 50 deg. C, 40 min, and 10 min for 15 mL of preconcentrated solution. The method presented precision (R.S.D.) between 1.3% and 2.6% (n = 9). The concentration factors with and without dilution of the surfactant-rich phase for the analytes ranged from 9.4 to 10.1 and from 94.0 to 100.1, respectively. The limits of detection (L.O.D.) obtained for copper, zinc, cadmium, and nickel were 1.2, 1.1, 1.0, and 6.3 {mu}g L{sup -1}, respectively. The accuracy of the procedure was evaluated through recovery experiments on aqueous samples.

  15. Simultaneous preconcentration of copper, zinc, cadmium, and nickel in water samples by cloud point extraction using 4-(2-pyridylazo)-resorcinol and their determination by inductively coupled plasma optic emission spectrometry.

    Science.gov (United States)

    Silva, Edson Luiz; Roldan, Paulo dos Santos; Giné, Maria Fernanda

    2009-11-15

    A procedure for simultaneous separation/preconcentration of copper, zinc, cadmium, and nickel in water samples, based on cloud point extraction (CPE) as a prior step to their determination by inductively coupled plasma optic emission spectrometry (ICP-OES), has been developed. The analytes reacted with 4-(2-pyridylazo)-resorcinol (PAR) at pH 5 to form hydrophobic chelates, which were separated and preconcentrated in a surfactant-rich phase of octylphenoxypolyethoxyethanol (Triton X-114). The parameters affecting the extraction efficiency of the proposed method, such as sample pH, complexing agent concentration, buffer amount, surfactant concentration, temperature, kinetics of complexation reaction, and incubation time were optimized and their respective values were 5, 0.6 mmol L(-1), 0.3 mL, 0.15% (w/v), 50 degrees C, 40 min, and 10 min for 15 mL of preconcentrated solution. The method presented precision (R.S.D.) between 1.3% and 2.6% (n=9). The concentration factors with and without dilution of the surfactant-rich phase for the analytes ranged from 9.4 to 10.1 and from 94.0 to 100.1, respectively. The limits of detection (L.O.D.) obtained for copper, zinc, cadmium, and nickel were 1.2, 1.1, 1.0, and 6.3 microg L(-1), respectively. The accuracy of the procedure was evaluated through recovery experiments on aqueous samples.

  16. Temperature-dependent accumulation mode particle and cloud nuclei concentrations from biogenic sources during WACS 2010

    Directory of Open Access Journals (Sweden)

    L. Ahlm

    2012-10-01

    Full Text Available Submicron aerosol particles collected simultaneously at the mountain peak (2182 m a.s.l. and at a forested mid-mountain site (1300 m a.s.l. on Whistler Mountain, British Columbia, Canada, during June and July 2010 were analyzed by Fourier transform infrared (FTIR spectroscopy for quantification of organic functional groups. Positive matrix factorization (PMF was applied to the FTIR spectra. Three PMF factors associated with (1 combustion, (2 biogenics, and (3 vegetative detritus, were identified at both sites. The biogenic factor was correlated with both temperature and several volatile organic compounds (VOCs. The combustion factor dominated the submicron particle mass during the beginning of the campaign when the temperature was lower and advection was from the Vancouver area, but as the temperature started to rise in early July the biogenic factor came to dominate as a result of increased emissions of biogenic VOCs and thereby increased formation of secondary organic aerosol (SOA. On average, the biogenic factor represented 69% and 49% of the submicron organic particle mass at Whistler Peak and at the mid-mountain site, respectively. The lower fraction at the mid-mountain site was a result of more vegetative detritus there, and also higher influence from local combustion sources.

    The biogenic factor was strongly correlated (r ~ 0.9 to number concentration of particles with diameter (Dp> 100 nm, whereas the combustion factor was better correlated to number concentration of particles with Dp < 100 nm (r~ 0.4. The number concentration of cloud condensation nuclei (CCN was correlated (r ~ 0.7 to the biogenic factor for supersaturations (S of 0.2% or higher, which indicates that particle condensational growth from biogenic vapors was an important factor in controlling the CCN concentration for clouds where S≥0.2%. Both the number concentration of particles with

  17. Temperature-dependent accumulation mode particle and cloud nuclei concentrations from biogenic sources during WACS 2010

    Directory of Open Access Journals (Sweden)

    L. Ahlm

    2013-03-01

    Full Text Available Submicron aerosol particles collected simultaneously at the mountain peak (2182 m a.s.l. and at a forested mid-mountain site (1300 m a.s.l. on Whistler Mountain, British Columbia, Canada, during June and July 2010 were analyzed by Fourier transform infrared (FTIR spectroscopy for quantification of organic functional groups. Positive matrix factorization (PMF was applied to the FTIR spectra. Three PMF factors associated with (1 combustion, (2 biogenics, and (3 vegetative detritus were identified at both sites. The biogenic factor was correlated with both temperature and several volatile organic compounds (VOCs. The combustion factor dominated the submicron particle mass during the beginning of the campaign, when the temperature was lower and advection was from the Vancouver area, but as the temperature started to rise in early July, the biogenic factor came to dominate as a result of increased emissions of biogenic VOCs, and thereby increased formation of secondary organic aerosol (SOA. On average, the biogenic factor represented 69% and 49% of the submicron organic particle mass at Whistler Peak and at the mid-mountain site, respectively. The lower fraction at the mid-mountain site was a result of more vegetative detritus there, and also higher influence from local combustion sources. The biogenic factor was strongly correlated (r~0.9 to number concentration of particles with diameter (Dp> 100 nm, whereas the combustion factor was better correlated to number concentration of particles with Dpr~0.4. The number concentration of cloud condensation nuclei (CCN was correlated (r~0.7 to the biogenic factor for supersaturations (S of 0.2% or higher, which indicates that particle condensational growth from biogenic vapors was an important factor in controlling the CCN concentration for clouds where S≥0.2%. Both the number concentration of particles with Dp>100 nm and numbers of CCN for S≥0.2% were correlated to temperature. Considering the biogenic

  18. Effect of inhibitors on corrosion behavior of copper-nickel in concentrated lithium bromide solution at high temperature

    Institute of Scientific and Technical Information of China (English)

    黄乃宝; 梁成浩; 佟大维

    2002-01-01

    The conventional mass-loss tests and the electrochemical techniques were used to study the inhibition action of LiOH and Na2MoO4 either individually or in different combination for copper-nickel alloy in boiling 65%LiBr solution. It indicates that the corrosion rate of copper-nickel is decreased when LiOH or Na2MoO4 is added to the solution individually. LiOH concentration has a double-effect on the corrosion behavior of copper-nickel. Low concentration is benefit to forming oxide film. High concentration results in dissolution of oxide film. The optimal concentration of LiOH is 0.15mol/L. The dissolution of copper-nickel is effectively prevented when adding 200mg/L Na2MoO4 to boiling 65%LiBr solution with 0.15mol/L LiOH. The inhibition mechanism is considered that the films of Cu, Ni, Mo oxides and deposited nonprotective in soluble CuBr on the surface of metal could prevent Br- ion from absorption, which prevent alloy dissolving.

  19. Preliminary results of determination of chemical element concentrations in the aerosol of Venus clouds

    Science.gov (United States)

    Andreychikov, B. M.; Mukhin, L. M.; Korchuganov, B. N.; Akhmetshin, I. K.; Tokarev, Y. N.; Medvedev, A. V.; Goldfeld, M. N.; Faynboym, V. M.; Kalyuzhnyy, A. V.; Petryanov, I. V.

    1986-01-01

    An X-ray radiometeric experiment is described along with the results of measurements of the elemental composition of aerosols in Venusian clouds. A preliminary analysis of the data showed that sulfur is present in the range of heights 63 to 47 km with mean content of 5.8 mg/cu m and that chlorine is present in the height range 61 t0 52 km with a mean content of 4.1 mg/cu m. The results of measurements in the range 52 to 47 km may come to an agreement if phosphorus is present in the aerosol with a mean concentration of 7.7 mg/cu m.

  20. The effect of copper concentration on the microstructure of Al-Si-Cu alloys

    Directory of Open Access Journals (Sweden)

    R. Maniara

    2007-04-01

    Full Text Available In the metal casting industry, an improvement of component quality depends mainly on better control over the production parameters. In order to gain a better understanding of how to control the as-cast microstructure, it is important to understand the evaluation of microstructure during solidification and understanding how influence the changes of chemical concentration on this microstructure. In this research, the effect of Cu content on the microstructure and solidification parameters of Al-Si-Cu alloys has been investigated. Thus, the thermal analysis of the alloys is used to control of aluminum casting process. The effect of different Cu content on solidification parameters such: aluminum dendrites nucleation temperature (TLiq, Liquidus temperature, α+β eutectic nucleation temperature (TE(Al+SiN, Cu-rich eutectic nucleation temperature (TAl+Cu, solidus temperature (Tsol, solidification range (ΔTs has been studied in liquidus region. Influence of Cu content on the microstructure has been carried out. The principle observation made from this work ware that as copper concentration is increased the liquidus and solodius temperature decried. In addition to this it was observed that increase a Cu content from 1 to 4 wt % caused reduce of the secondary dendrite arm spacing and increase the grain size.

  1. Copper and vitamin A concentrations in the blood of normal and Cu-poisoned sheep

    Energy Technology Data Exchange (ETDEWEB)

    Moore, T.; Sharman, I.M.; Todd, J.R.; Thompson, R.H.

    1972-01-01

    In experimental sheep the culmination of chronic copper poisoning, as manifested by the onset of hemolysis and greatly increased blood Cu levels, was accompanied by much-reduced plasma concentrations of retinol, which was not due merely to the dilution of the plasma by the products of broken corpuscles. A further instance can therefore be added to the series of inverse relationships already known to apply between Cu and retinol. In specimens of blood taken from normal sheep in the field, however, a direct correlation between Cu and retinol was found, indicating that the inverse relationship is not universally applicable in all physiological and nutritional conditions. The liver of a single lamb that died from swayback, associated with Cu deficiency during pregnancy, contained only traces of Cu, but had a retinol content at the top of the normal range. The livers of two lambs that had been dosed with Cu, but had failed to develop hemolytic crises, contained high concentrations of Cu, with retinol within the normal range. 31 references, 4 figures, 1 table.

  2. Cadmium, Chromium, and Copper Concentration plus Semen-Quality in Environmental Pollution Site, China

    Science.gov (United States)

    LI, Yan; GAO, Qiaoyan; LI, Mingcai; LI, Mengyang; GAO, Xueming

    2014-01-01

    Abstract Background The environmental pollution is one of the factors contributing to the decrease of sperm quality for human beings. The aim of this study was to assess cadmium (Cd), chromium (Cr), and copper (Cu) concentration of man in environmental pollution site, and explore relationships between men exposure to Cd, Cr, and Cu and semen-quality parameters in environmental pollution site. Methods Ninety five men were recruited through pollution area and controls in 2011. We measured semen quality using Computer-aided Semen Quality Analysis, and Cd, Cr, and Cu levels in seminal plasma using Graphite Gurnace Atomic Absorption Spectroscopy. Spearman rank correlation analysis was used to evaluate the correlation between Cd, Cr and Cu concentration in seminal plasma and semen quality. Results The mean of seminal plasma Cd, Cr, and Cu values in pollution area was higher than the controls. Seminal plasma Cr values displayed a significant negative correlation with total motility and normomorph sperm rate. Seminal plasma Cu values also displayed a negative correlation with normomorph sperm rate. Conclusions Male reproductive health may be threatened by environmental pollution, and it may be influence local population diathesis. PMID:26060677

  3. Pre-Cloud Aerosol, Cloud Droplet Concentration, and Cloud Condensation Nuclei from the VAMOS Ocean-Cloud-Atmosphere Land Study (VOCALS) Field Campaign First Quarter 2010 ASR Program Metric Report

    Energy Technology Data Exchange (ETDEWEB)

    Kleinman, LI; Springston, SR; Daum, PH; Lee, Y-N; Sedlacek, AJ; Senum, G; Wang, J

    2011-08-31

    In this, the first of a series of Program Metric Reports, we (1) describe archived data from the DOE G-1 aircraft, (2) illustrate several relations between sub-cloud aerosol, CCN, and cloud droplets pertinent to determining the effects of pollutant sources on cloud properties, and (3) post to the data archive an Excel spreadsheet that contains cloud and corresponding sub-cloud data.

  4. Activities of titanium in molten copper at dilute concentrations measured by solid- state electrochemical cells at 1373 K

    Science.gov (United States)

    Hoshino, H.; Shimada, T.; Yamamoto, M.; Iwase, M.

    1992-03-01

    In order to obtain the activities of titanium in molten copper at dilute concentrations, i.e., between 5 x 10-6 and 3.4 x 10-3 titanium mole fractions, liquid copper was brought into equilibrium with molten {CaCl2 + Ti2O3} slag saturated with Ti2O3 (s) at 1373 K and the equilibrium oxygen partial pressures were measured by means of a solid-oxide galvanic cell of the type Mo/Mo + MoO2/ZrO2(MgO)/(Cu + Ti)alloy + Ti2O3 + CaCl2 + Ti2O3 slag/Mo The free energy change for the dissolution of solid titanium in molten copper at infinite dilution referred to 1 wt pet was determined as Ti (s) = Ti(1 wt pet in Cu) ΔG°/J = -86,100 ± 8900 at 1373 K

  5. Cloud point extraction of copper, lead, cadmium, and iron using 2,6-diamino-4-phenyl-1,3,5-triazine and nonionic surfactant, and their flame atomic absorption spectrometric determination in water and canned food samples.

    Science.gov (United States)

    Citak, Demirhan; Tuzen, Mustafa

    2012-01-01

    A cloud point extraction procedure was optimized for the separation and preconcentration of lead(II), cadmium(II), copper(II), and iron(III) ions in various water and canned food samples. The metal ions formed complexes with 2,6-diamino-4-phenyl-1,3,5-triazine that were extracted by surfactant-rich phases in the nonionic surfactant Triton X-114. The surfactant-rich phase was diluted with 1 M HNO3 in methanol prior to its analysis by flame atomic absorption spectrometry. The parameters affecting the extraction efficiency of the proposed method, such as sample pH, complexing agent concentration, surfactant concentration, temperature, and incubation time, were optimized. LOD values based on three times the SD of the blank (3Sb) were 0.38, 0.48, 1.33, and 1.85 microg/L for cadmium(II), copper(II), lead(II), and iron(III) ions, respectively. The precision (RSD) of the method was in the 1.86-3.06% range (n=7). Validation of the procedure was carried out by analysis of National Institute of Standards and Technology Standard Reference Material (NIST-SRM) 1568a Rice Flour and GBW 07605 Tea. The method was applied to water and canned food samples for determination of metal ions.

  6. Effect of primary organic sea spray emissions on cloud condensation nuclei concentrations

    Directory of Open Access Journals (Sweden)

    D. M. Westervelt

    2012-01-01

    Full Text Available This work estimates the primary marine organic aerosol global emission source and its impact on cloud condensation nuclei (CCN concentrations by implementing an organic sea spray source function into a series of global aerosol simulations. The source function assumes that a fraction of the sea spray emissions, depending on the local chlorophyll concentration, is organic matter in place of sea salt. Effect on CCN concentrations (at 0.2% supersaturation is modeled using the Two-Moment Aerosol Sectional (TOMAS microphysics algorithm coupled to the GISS II-prime general circulation model. The presence of organics affects CCN activity in competing ways: by reducing the amount of solute available in the particle and decreasing surface tension of CCN. To model surfactant effects, surface tension depression data from seawater samples taken near the Georgia coast were applied as a function of carbon concentrations. A global marine organic aerosol emission rate of 17.7 Tg C yr−1 is estimated from the simulations. Marine organics exert a localized influence on CCN(0.2% concentrations, decreasing regional concentrations by no more than 5% and by less than 0.5% over most of the globe, assuming direct replacement of sea salt aerosol with organic aerosol. The decrease in CCN concentrations results from the fact that the decrease in particle solute concentration outweighs the organic surfactant effects. The low sensitivity of CCN(0.2% to the marine organic emissions is likely due to the small compositional changes: the mass fraction of OA in accumulation mode aerosol increases by only ~15% in a biologically active region of the Southern Ocean. To test the sensitivity to uncertainty in the sea spray emissions process, we relax the assumption that sea spray aerosol number and mass remain fixed and instead can add to sea spray emissions rather than replace existing sea salt. In these simulations, we find that marine organic aerosol can increase CCN by

  7. Preconcentration and determination of iron and copper in spice samples by cloud point extraction and flow injection flame atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Sahin, Cigdem Arpa, E-mail: carpa@hacettepe.edu.tr [Hacettepe University, Chemistry Department, 06800 Beytepe, Ankara (Turkey); Tokgoez, Ilknur; Bektas, Sema [Hacettepe University, Chemistry Department, 06800 Beytepe, Ankara (Turkey)

    2010-09-15

    A flow injection (FI) cloud point extraction (CPE) method for the determination of iron and copper by flame atomic absorption spectrometer (FAAS) has been improved. The analytes were complexed with 3-amino-7-dimethylamino-2-methylphenazine (Neutral Red, NR) and octylphenoxypolyethoxyethanol (Triton X-114) was added as a surfactant. The micellar solution was heated above 50 {sup o}C and loaded through a column packed with cotton for phase separation. Then the surfactant-rich phase was eluted using 0.05 mol L{sup -1} H{sub 2}SO{sub 4} and the analytes were determined by FAAS. Chemical and flow variables influencing the instrumental and extraction conditions were optimized. Under optimized conditions for 25 mL of preconcentrated solution, the enrichment factors were 98 and 69, the limits of detection (3s) were 0.7 and 0.3 ng mL{sup -1}, the limits of quantification (10s) were 2.2 and 1.0 ng mL{sup -1} for iron and copper, respectively. The relative standard deviation (RSD) for ten replicate measurements of 10 ng mL{sup -1} iron and copper were 2.1% and 1.8%, respectively. The proposed method was successfully applied to determination of iron and copper in spice samples.

  8. Estimation of free copper ion concentrations in blood serum using T1 relaxation rates

    Science.gov (United States)

    Blicharska, Barbara; Witek, Magdalena; Fornal, Maria; MacKay, Alex L.

    2008-09-01

    The water proton relaxation rate constant R1 = 1/ T1 (at 60 MHz) of blood serum is substantially increased by the presence of free Cu 2+ ions at concentrations above normal physiological levels. Addition of chelating agents to serum containing paramagnetic Cu 2+ nulls this effect. This was demonstrated by looking at the effect of adding a chelating agent—D-penicillamine (D-PEN) to CuSO 4 and CuCl 2 aqueous solutions as well as to rabbit blood serum. We propose that the measurement of water proton spin-lattice relaxation rate constants before and after chelation may be used as an alternative approach for monitoring the presence of free copper ions in blood serum. This method may be used in the diagnosis of some diseases (leukaemia, liver diseases and particularly Wilson's disease) because, in contrast to conventional methods like spectrophotometry which records the total number of both bound and free ions, the proton relaxation technique is sensitive solely to free paramagnetic ions dissolved in blood serum. The change in R1 upon chelation was found to be less than 0.06 s -1 for serum from healthy subjects but greater than 0.06 s -1 for serum from untreated Wilson's patients.

  9. Effects of Soil Copper Concentration on Growth, Development and Yield Formation of Rice (Oryza sativa)

    Institute of Scientific and Technical Information of China (English)

    XU Jia-kuan; YANG Lian-xin; WANG Zi-qiang; DONG Gui-chun; HUANG Jian-ye; WANG Yu-long

    2005-01-01

    Pot experiments were conducted in 2002 and 2003 to investigate the effects of soil copper(Cu) concentration on growth, development and yield formation of rice by using the japonica cultivar Wuxiangjing 14 and hybrid rice combination Shanyou 63. The plant height, leaf number, elongated internode number and heading date of rice plants were not affected at soil Cu levels below 200 mg/kg, but affected significantly at above 400 mg/kg. The inhibitory effects on rice growth and development were increased with the increment of soil Cu levels. The grain yields decreased significantly with raising soil Cu levels. The main reasons for the grain yield reductions under lower soil Cu levels (100, 200 mg/kg) were mainly due to the decrease of number of spikelets per panicle, however, under higher soil Cu levels (more than 400 mg/kg), both panicle number and number of spikelets per panicle contributed to the yield loss. The decreases of panicle number by Cu stress were mainly attributed to slow recovery from transplanting, delayed tillering and reduced maximum tiller numbers. The reduction of number of spikelets per panicle under soil Gu stress resulted from the decreases of both shoot dry weight (SDW) at the heading date and the ratio of spikelets to SDW.Total biomass at maturity decreased significantly with the increase of soil Cu levels, while economic coefficient showed non-significant decrease except under soil Cu levels above 800 mg/kg.

  10. Antioxidants activities and concentration of selenium, zinc and copper in preterm and IUGR human placentas.

    Science.gov (United States)

    Zadrozna, Monika; Gawlik, Małgorzata; Nowak, Barbara; Marcinek, Antoni; Mrowiec, Halina; Walas, Stanisław; Wietecha-Posłuszny, Renata; Zagrodzki, Paweł

    2009-01-01

    The aim of this study was to examine changes in activities of cytochrome c oxidase (CCO), glucose-6-phosphate dehydrogenase (G6PDH), Cu-Zn superoxide dismutase (Cu-Zn SOD), glutathione peroxidase (GSH-Px), glutathione (GSH) levels and copper (Cu), zinc (Zn) and selenium (Se) concentrations, and to assess the possible differences between preterm placentas, placentas from term pregnancies complicated by intrauterine growth restriction (IUGR) and full-term control placentas. The enzyme activities and the level of GSH decreased in IUGR and preterm placentas in comparison with the control group. CCO activity and GSH level in preterm placentas were markedly lower compared with the IUGR (P<0.01; P<0.05) and control (P<0.01; P<0.05) placentas, respectively. In IUGR placentas the level of Cu was reduced by 23% (P<0.05) and Zn by 37%. In preterm placentas the level of Cu was reduced by 19% and Zn by 42%. Se level in IUGR and preterm placentas was higher (P<0.05) by 28% and 32% than in control group, respectively. The strong relation was observed between birth weight and CCO activity, birth weight and Cu-Zn SOD activity, and a low level of Zn and Cu influenced the birth weight especially in IUGR cases. Moreover, the strong inverse correlation between Se level and birth weight, Se level and placental weight and Se level and CCO activity are new findings.

  11. The copper-nickel concentration log: A tool for stratigraphic interpretation within the ultramafic and basal zones of the stillwater complex, Montana

    Science.gov (United States)

    Drew, L.J.; Bawiec, W.J.; Page, N.J.; Schuenemeyer, J.H.

    1985-01-01

    An analogue to the electric well log was devised for copper-nickel concentration drill-hole data from the Basal and lower part of the Ultramafic zones of the Stillwater Complex using automated data processing. The copper-nickel concentration logs graphically represent intensity (concentration) values that reflect the distribution of the elements in sulfide and silicate minerals. Four major patterns are recognized by their characteristic variations in copper and nickel intensity: (1) relatively flat, low-level copper-intensity signatures associated with arcuate nickel-intensity patterns that correlate with rocks in the Peridotite member of the Ultramafic zone; (2) arcuate or bulb-like patterns of copper and nickel intensity that correlate closely with the Basal bronzite cumulate member of the Basal zone; (3) complex patterns consisting of intervals of low-intensity copper and moderate-intensity nickel, spikes of high nickel and copper intensity, and high copper intensity associated with low nickel intensity that correlate respectively with cordierite-pyroxene hornfels, massive sulfide, norites and mineralized diabase dikes in the Basal norite member; and (4) large intervals of extremely low copper and nickel intensity that correlate with quartz-orthopyroxene hornfels. The recognition and interpretation of these patterns allow two- and three-dimensional stratigraphic and lithologic reconstructions to be done by means of concentration-log correlations instead of variable quality lithologic logging. ?? 1985.

  12. Anomalously high arsenic concentration in a West Antarctic ice core and its relationship to copper mining in Chile

    Science.gov (United States)

    Schwanck, Franciele; Simões, Jefferson C.; Handley, Michael; Mayewski, Paul A.; Bernardo, Ronaldo T.; Aquino, Francisco E.

    2016-01-01

    Arsenic variability records are preserved in snow and ice cores and can be utilized to reconstruct air pollution history. The Mount Johns ice core (79°55‧S; 94°23‧W and 91.2 m depth) was collected from the West Antarctic Ice Sheet in the 2008/09 austral summer. Here, we report the As concentration variability as determined by 2137 samples from the upper 45 m of this core using ICP-SFMS (CCI, University of Maine, USA). The record covers approximately 125 years (1883-2008) showing a mean concentration of 4.32 pg g-1. The arsenic concentration in the core follows global copper mining evolution, particularly in Chile (the largest producer of Cu). From 1940 to 1990, copper-mining production increased along with arsenic concentrations in the MJ core, from 1.92 pg g-1 (before 1900) to 7.94 pg g-1 (1950). In the last two decades, environmental regulations for As emissions have been implemented, forcing smelters to treat their gases to conform to national and international environmental standards. In Chile, decontamination plants required by the government started operating from 1993 to 2000. Thereafter, Chilean copper production more than doubled while As emission levels declined, and the same reduction was observed in the Mount Johns ice core. After 1999, arsenic concentrations in our samples decreased to levels comparable to the period before 1900.

  13. Cloud ice caused by atmospheric mineral dust - Part 1: Parameterization of ice nuclei concentration in the NMME-DREAM model

    Science.gov (United States)

    Nickovic, Slobodan; Cvetkovic, Bojan; Madonna, Fabio; Rosoldi, Marco; Pejanovic, Goran; Petkovic, Slavko; Nikolic, Jugoslav

    2016-09-01

    Dust aerosols are very efficient ice nuclei, important for heterogeneous cloud glaciation even in regions distant from desert sources. A new generation of ice nucleation parameterizations, including dust as an ice nucleation agent, opens the way towards a more accurate treatment of cold cloud formation in atmospheric models. Using such parameterizations, we have developed a regional dust-atmospheric modelling system capable of predicting, in real time, dust-induced ice nucleation. We executed the model with the added ice nucleation component over the Mediterranean region, exposed to moderate Saharan dust transport, over two periods lasting 15 and 9 days, respectively. The model results were compared against satellite and ground-based cloud-ice-related measurements, provided by SEVIRI (Spinning Enhanced Visible and InfraRed Imager) and the CNR-IMAA Atmospheric Observatory (CIAO) in Potenza, southern Italy. The predicted ice nuclei concentration showed a reasonable level of agreement when compared against the observed spatial and temporal patterns of cloud ice water. The developed methodology permits the use of ice nuclei as input into the cloud microphysics schemes of atmospheric models, assuming that this approach could improve the predictions of cloud formation and associated precipitation.

  14. Influence of electron donors and copper concentration on geochemical and mineralogical processes under conditions of biological sulphate reduction

    Science.gov (United States)

    Wolicka, Dorota; Borkowski, Andrzej

    2014-03-01

    Sulphidogenous microorganism communities were isolated from soil polluted by crude oil. The study was focused on determining the influence of 1) copper (II) concentration on the activity of selected microorganism communities and 2) the applied electron donor on the course and evolution of mineral-forming processes under conditions favouring growth of sulphate-reducing bacteria (SRB). The influence of copper concentration on the activity of selected microorganism communities and the type of mineral phases formed was determined during experiments in which copper (II) chloride at concentrations of 0.1, 0.2, 0.5 and 0.7 g/L was added to SRB cultures. The experiments were performed in two variants: with ethanol (4 g/L) or lactate (4 g/L) as the sole carbon source. In order to determine the taxonomic composition of the selected microorganism communities, the 16S rRNA method was used. Results of this analysis confirmed the presence of Desulfovibrio, Desulfohalobium, Desulfotalea, Thermotoga, Solibacter, Gramella, Anaeromyxobacter and Myxococcus sp. in the stationary cultures. The post-culture sediments contained covelline (CuS) and digenite (Cu9S5 ). Based on the results, it can be stated that the type of carbon source applied during incubation plays a crucial role in determining the mineral composition of the post-culture sediments. Thus, regardless of the amount of copper ion introduced to a culture with lactate as the sole carbon source, no copper sulphide was observed in the post-culture sediments. Cultures with ethanol as the sole carbon source, on the other hand, yielded covelline or digenite in all post-culture sediments.

  15. Closure Between Measured and Predicted Cloud Condensation Nuclei Concentration at Kanpur, Indo-Gangetic Basin

    Science.gov (United States)

    Bhattu, D.; Tripathi, S. N.

    2013-12-01

    Aerosols play a significant role in the Earth climate system directly by absorbing and scattering sunlight, and indirectly by acting as cloud condensation nuclei (CCN), ultimately affecting the cloud microphysical and radiative properties. To reduce the uncertainty involved in global radiative forcing assessment, there is a need to quantify the effect of chemical composition and mixing state on the hygroscopic growth of aerosols to understand their CCN activity. The role of soluble inorganics as a single component system in droplet activation is well understood, while the properties of organics and their mixtures need further studies. To understand the CCN activity of the ambient aerosols, relative contribution of the major factors like, aerosol size distribution, size resolved chemical composition and mixing state needs to be understood. Past studies have tested the performance of CCN closure study depending on how well the chemical composition, mainly organics, and mixing state of aerosols is treated. It has been found that the comparison between modelled and measured CCN concentration improves as the distance from the source region increases because the particles become more internally mixed and less size dependent. Measurements were conducted for 21 days in November, 2012 at the Indian Institute of Technology Kanpur (80 20'E, 26 26'N), India. Round the clock sampling of aerosol size distribution, chemical composition and cloud condensation nuclei (CCN) at various supersaturations (0.2-1%) was done to understand the diurnal variability of CCN properties of aerosols. The main goal of this study is to perform CCN closure study by focusing into the effect of organics and their hygroscopicity on CCN activity. Kohler theory is used to predict the CCN concentration at five different SS from the size distribution obtained from Scanning Mobility Particle Sizer (SMPS) and chemical composition (bulk and size resolved) from Aerodyne HR-ToF-AMS assuming different mixing

  16. In-situ aircraft observations of ice concentrations within clouds over the Antarctic Peninsula and Larsen Ice Shelf

    Directory of Open Access Journals (Sweden)

    D. P. Grosvenor

    2012-12-01

    Full Text Available In-situ aircraft observations of ice crystal concentrations in Antarctic clouds are presented for the first time. Orographic, layer and wave clouds around the Antarctic Peninsula and Larsen Ice shelf regions were penetrated by the British Antarctic Survey's Twin Otter aircraft, which was equipped with modern cloud physics probes. The clouds studied were mostly in the free troposphere and hence ice crystals blown from the surface are unlikely to have been a major source for the ice phase. The temperature range covered by the experiments was 0 to −21 °C. The clouds were found to contain supercooled liquid water in most regions and at heterogeneous ice formation temperatures ice crystal concentrations (60 s averages were often less than 0.07 l−1, although values up to 0.22 l−1 were observed. Estimates of observed aerosol concentrations were used as input into the DeMott et al. (2010 ice nuclei (IN parameterisation. The observed ice crystal number concentrations were generally in broad agreement with the IN predictions, although on the whole the predicted values were higher. Possible reasons for this are discussed and include the lack of IN observations in this region with which to characterise the parameterisation, and/or problems in relating ice concentration measurements to IN concentrations. Other IN parameterisations significantly overestimated the number of ice particles. Generally ice particle concentrations were much lower than found in clouds in middle latitudes for a given temperature.

    Higher ice crystal concentrations were sometimes observed at temperatures warmer than −9 °C, with values of several per litre reached. These were attributable to secondary ice particle production by the Hallett Mossop process. Even in this temperature range it was observed that there were regions with little or no ice that were dominated by supercooled liquid water. It is likely that in some cases this was due to a

  17. Measured and modelled cloud condensation nuclei number concentration at the high alpine site Jungfraujoch

    Directory of Open Access Journals (Sweden)

    Z. Jurányi

    2010-08-01

    Full Text Available Atmospheric aerosol particles are able to act as cloud condensation nuclei (CCN and are therefore important for the climate and the hydrological cycle, but their properties are not fully understood. Total CCN number concentrations at 10 different supersaturations in the range of SS=0.12–1.18% were measured in May 2008 at the remote high alpine research station, Jungfraujoch, Switzerland (3580 m a.s.l.. In this paper, we present a closure study between measured and predicted CCN number concentrations. CCN predictions were done using dry number size distribution (scanning particle mobility sizer, SMPS and bulk chemical composition data (aerosol mass spectrometer, AMS, and multi-angle absorption photometer, MAAP in a simplified Köhler theory. The predicted and the measured CCN number concentrations agree very well and are highly correlated. A sensitivity study showed that the temporal variability of the chemical composition at the Jungfraujoch can be neglected for a reliable CCN prediction, whereas it is important to know the mean chemical composition. The exact bias introduced by using a too low or too high hygroscopicity parameter for CCN prediction was further quantified and shown to be substantial for the lowest supersaturation.

    Despite the high average organic mass fraction (~45% in the fine mode, there was no indication that the surface tension was substantially reduced at the point of CCN activation. A comparison between hygroscopicity tandem differential mobility analyzer (HTDMA, AMS/MAAP, and CCN derived κ values showed that HTDMA measurements can be used to determine particle hygroscopicity required for CCN predictions if no suitable chemical composition data are available.

  18. Measured and modelled cloud condensation nuclei concentration at the high alpine site Jungfraujoch

    Science.gov (United States)

    Jurányi, Z.; Gysel, M.; Weingartner, E.; Decarlo, P. F.; Kammermann, L.; Baltensperger, U.

    2010-04-01

    Atmospheric aerosol particles are able to act as cloud condensation nuclei (CCN) and are therefore important for the climate and the hydrological cycle, but their properties are not fully understood. Total CCN number concentrations at 10 different supersaturations in the range of SS = 0.12-1.18% were measured in May 2008 at the remote high alpine research station, Jungfraujoch, Switzerland (3580 m asl.). In this paper, we present a closure study between measured and predicted CCN number concentrations. CCN predictions were done using number size distribution (scanning particle mobility sizer, SMPS) and bulk chemical composition data (aerosol mass spectrometer, AMS, and multi-angle absorption photometer, MAAP) in a simplified Köhler theory. The predicted and the measured CCN concentrations agree very well and are highly correlated. A sensitivity study showed that the temporal variability of the chemical composition at the Jungfraujoch can be neglected for a reliable CCN prediction, whereas it is important to know the mean chemical composition. The exact bias introduced by using a too low or too high hygroscopicity parameter for CCN prediction was further quantified and shown to be substantial for the lowest supersaturation. Despite the high average organic mass fraction (45%) during the measurement campaign, there was no indication that the surface tension was substantially reduced at the point of CCN activation. A comparison between hygroscopicity tandem differential mobility analyzer (HTDMA), AMS/MAAP, and CCN derived κ values showed that HTDMA measurements can be used as a chemical composition proxy for CCN predictions if no suitable chemical composition data are available.

  19. Measured and modelled cloud condensation nuclei concentration at the high alpine site Jungfraujoch

    Directory of Open Access Journals (Sweden)

    Z. Jurányi

    2010-04-01

    Full Text Available Atmospheric aerosol particles are able to act as cloud condensation nuclei (CCN and are therefore important for the climate and the hydrological cycle, but their properties are not fully understood. Total CCN number concentrations at 10 different supersaturations in the range of SS = 0.12–1.18% were measured in May 2008 at the remote high alpine research station, Jungfraujoch, Switzerland (3580 m asl.. In this paper, we present a closure study between measured and predicted CCN number concentrations. CCN predictions were done using number size distribution (scanning particle mobility sizer, SMPS and bulk chemical composition data (aerosol mass spectrometer, AMS, and multi-angle absorption photometer, MAAP in a simplified Köhler theory. The predicted and the measured CCN concentrations agree very well and are highly correlated. A sensitivity study showed that the temporal variability of the chemical composition at the Jungfraujoch can be neglected for a reliable CCN prediction, whereas it is important to know the mean chemical composition. The exact bias introduced by using a too low or too high hygroscopicity parameter for CCN prediction was further quantified and shown to be substantial for the lowest supersaturation.

    Despite the high average organic mass fraction (45% during the measurement campaign, there was no indication that the surface tension was substantially reduced at the point of CCN activation. A comparison between hygroscopicity tandem differential mobility analyzer (HTDMA, AMS/MAAP, and CCN derived κ values showed that HTDMA measurements can be used as a chemical composition proxy for CCN predictions if no suitable chemical composition data are available.

  20. Measured and modelled cloud condensation nuclei number concentration at the high alpine site Jungfraujoch

    Science.gov (United States)

    Jurányi, Z.; Gysel, M.; Weingartner, E.; Decarlo, P. F.; Kammermann, L.; Baltensperger, U.

    2010-08-01

    Atmospheric aerosol particles are able to act as cloud condensation nuclei (CCN) and are therefore important for the climate and the hydrological cycle, but their properties are not fully understood. Total CCN number concentrations at 10 different supersaturations in the range of SS=0.12-1.18% were measured in May 2008 at the remote high alpine research station, Jungfraujoch, Switzerland (3580 m a.s.l.). In this paper, we present a closure study between measured and predicted CCN number concentrations. CCN predictions were done using dry number size distribution (scanning particle mobility sizer, SMPS) and bulk chemical composition data (aerosol mass spectrometer, AMS, and multi-angle absorption photometer, MAAP) in a simplified Köhler theory. The predicted and the measured CCN number concentrations agree very well and are highly correlated. A sensitivity study showed that the temporal variability of the chemical composition at the Jungfraujoch can be neglected for a reliable CCN prediction, whereas it is important to know the mean chemical composition. The exact bias introduced by using a too low or too high hygroscopicity parameter for CCN prediction was further quantified and shown to be substantial for the lowest supersaturation. Despite the high average organic mass fraction (~45%) in the fine mode, there was no indication that the surface tension was substantially reduced at the point of CCN activation. A comparison between hygroscopicity tandem differential mobility analyzer (HTDMA), AMS/MAAP, and CCN derived κ values showed that HTDMA measurements can be used to determine particle hygroscopicity required for CCN predictions if no suitable chemical composition data are available.

  1. Effect of sample preparation methods on photometric determination of the tellurium and cobalt content in the samples of copper concentrates

    Directory of Open Access Journals (Sweden)

    Viktoriya Butenko

    2016-03-01

    Full Text Available Methods of determination of cobalt and nickel in copper concentrates currently used in factory laboratories are very labor intensive and time consuming. The limiting stage of the analysis is preliminary chemical sample preparation. Carrying out the decomposition process of industrial samples with concentrated mineral acids in open systems does not allow to improve the metrological characteristics of the methods, for this reason improvement the methods of sample preparation is quite relevant and has a practical interest. The work was dedicated to the determination of the optimal conditions of preliminary chemical preparation of copper concentrate samples for the subsequent determination of cobalt and tellurium in the obtained solution using tellurium-spectrophotometric method. Decomposition of the samples was carried out by acid dissolving in individual mineral acids and their mixtures by heating in an open system as well as by using ultrasonification and microwave radiation in a closed system. In order to select the optimal conditions for the decomposition of the samples in a closed system the phase contact time and ultrasonic generator’s power were varied. Intensification of the processes of decomposition of copper concentrates with nitric acid (1:1, ultrasound and microwave radiation allowed to transfer quantitatively cobalt and tellurium into solution spending 20 and 30 min respectively. This reduced the amount of reactants used and improved the accuracy of determination by running the process in strictly identical conditions.

  2. Response of Tribolium castaneum to elevated copper concentrations is influenced by history of metal exposure, sex-specific defences, and infection by the parasite Steinernema feltiae.

    Science.gov (United States)

    Kramarz, Paulina E; Mordarska, Anna; Mroczka, Magdalena

    2014-07-01

    We studied how copper toxicity in the red flour beetle, Tribolium castaneum changed as a result of infection by the entomopathogenic nematode Steinernema feltiae. Measured traits were: respiration, growth and survival, as well as the concentrations of copper within beetle tissues and in its diet. By comparing F1 and F5 generation we were able to answer how long-term metal exposure changed the responses to both copper and the parasite. The beetles did accumulate copper; however, the results indicated that copper concentrations in beetle tissues were affected by nematode infection, the sex of the experimental animals, and the number of generations of exposure. Five generations of exposure to copper resulted in the highest dry body mass of infected beetles of both sexes; additionally, this group also had the lowest copper concentrations in their tissues. The only factor that had a significant effect on respiration was infection by nematodes: infected beetles of both sexes in both generational groups had significantly decreased respiration rates. Survival was lowest in nematode-infected animals of both sexes from both generations, regardless of exposure to copper. Our results confirm that an organism's response to metal pollution is dependent on its health status and sex. We also found that the history of exposure to metal was equally important-we found enhanced resistance to copper intoxication after only five generations of exposure.

  3. Impacts of ENSO events on cloud radiative effects in preindustrial conditions: Changes in cloud fraction and their dependence on interactive aerosol emissions and concentrations: IMPACT OF ENSO ON CLOUD RADIATIVE EFFECT

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Yang [Scripps Institution of Oceanography, University of California, San Diego, La Jolla California USA; Now at Atmospheric Science and Global Change Division, Pacific Northwest National Laboratory, Richland Washington USA; Russell, Lynn M. [Scripps Institution of Oceanography, University of California, San Diego, La Jolla California USA; Xu, Li [Scripps Institution of Oceanography, University of California, San Diego, La Jolla California USA; Lou, Sijia [Scripps Institution of Oceanography, University of California, San Diego, La Jolla California USA; Lamjiri, Maryam A. [Scripps Institution of Oceanography, University of California, San Diego, La Jolla California USA; Somerville, Richard C. J. [Scripps Institution of Oceanography, University of California, San Diego, La Jolla California USA; Miller, Arthur J. [Scripps Institution of Oceanography, University of California, San Diego, La Jolla California USA; Cayan, Daniel R. [Scripps Institution of Oceanography, University of California, San Diego, La Jolla California USA; DeFlorio, Michael J. [Scripps Institution of Oceanography, University of California, San Diego, La Jolla California USA; Ghan, Steven J. [Atmospheric Science and Global Change Division, Pacific Northwest National Laboratory, Richland Washington USA; Liu, Ying [Atmospheric Science and Global Change Division, Pacific Northwest National Laboratory, Richland Washington USA; Singh, Balwinder [Atmospheric Science and Global Change Division, Pacific Northwest National Laboratory, Richland Washington USA; Wang, Hailong [Atmospheric Science and Global Change Division, Pacific Northwest National Laboratory, Richland Washington USA; Yoon, Jin-Ho [Gwangju Institute of Science and Technology, Gwangju South Korea; Rasch, Philip J. [Atmospheric Science and Global Change Division, Pacific Northwest National Laboratory, Richland Washington USA

    2016-06-02

    The impacts of the El Niño–Southern Oscillation (ENSO) events on shortwave and longwave cloud radiative effects (CRESW and CRELW) and the underlying changes in cloud fraction as well as aerosol emissions, wet scavenging and transport are quantified using three 150-year simulations in preindustrial conditions by the CESM model. Compared to recent observations from Clouds and the Earth’s Radiant Energy System (CERES), the model simulation successfully reproduced larger variations of CRESW over the tropical western and central Pacific, Indonesian regions, and the eastern Pacific Ocean, as well as large variations of CRELW located mainly within the tropics. The ENSO cycle is found to dominate interannual variations of cloud radiative effects, especially over the tropics. Relative to those during La Niña events, simulated cooling (warming) effects from CRESW (CRELW) during El Niño events are stronger over the tropical western and central Pacific Ocean, with the largest difference exceeding 40 Wm–2 (30 Wm–2), with weaker effects of 10–30 Wm–2 over Indonesian regions and the subtropical Pacific Ocean. Sensitivity tests show that variations of cloud radiative effects are mainly driven by ENSO-related changes in cloud fraction. The variations in medium and high cloud fractions each account for about 20–50% of the interannual variations of CRESW over the tropics and almost all of the variations of CRELW between 60°S and 60°N. The variation of low cloud fraction contributes most interannual variations of CRESW over the mid-latitude oceans. Variations in natural aerosol concentrations considering emissions, wet scavenging and transport explained 10–30% of the interannual variations of both CRESW and CRELW over the tropical Pacific, Indonesian regions and the tropical Indian Ocean. Changes in wet scavenging of natural aerosol modulate the variations of cloud radiative effects. Because of increased (decreased) precipitation over the tropical western Pacific

  4. Serum Copper Concentration in Newborns with Neural Tube Defects in Northern Iran; A Case Control Study

    Directory of Open Access Journals (Sweden)

    Azad-Reza Mansourian

    2009-04-01

    Full Text Available Objective: This study was conducted to determine the eventual association between copper deficiency in newborns with neural tube defects (NTD in Northern Iran. A high prevalence of neural tube defects has been reported from this region.Methods: This hospital based case control study was carried out on 13 newborns having neural tube defects and 35 healthy controls in Northern Iran during 2005-2006. Serum copper was measured by spectrophotometery.Findings: Serum copper level in newborns with NTD and healthy normal newborns was 16.5 (±7.2 μmol/l and 16.7 (±6.6 μmol/l, respectively. In case group 38.5% of newborns and in control group 28.6% had copper deficiency. Logistic regression analysis showed no association between the presence of NTD and copper deficiency (OR:1.6, 95% CI=0.3-7.1, P=0.5.Conclusion :This study showed no association between NTD and copper deficiency in newborns.

  5. Evaluation of the laser-induced breakdown spectroscopy technique for determination of the chemical composition of copper concentrates

    Energy Technology Data Exchange (ETDEWEB)

    Łazarek, Łukasz, E-mail: lukasz.lazarek@pwr.wroc.pl [Laser and Fiber Electronics Group, Faculty of Electronics, Wroclaw University of Technology, Wyb. Wyspianskiego 27, 50-370 Wroclaw (Poland); Antończak, Arkadiusz J.; Wójcik, Michał R. [Laser and Fiber Electronics Group, Faculty of Electronics, Wroclaw University of Technology, Wyb. Wyspianskiego 27, 50-370 Wroclaw (Poland); Drzymała, Jan [Faculty of Geoengineering, Mining and Geology, Wroclaw University of Technology, Wyb. Wyspianskiego 27, 50-370 Wroclaw (Poland); Abramski, Krzysztof M. [Laser and Fiber Electronics Group, Faculty of Electronics, Wroclaw University of Technology, Wyb. Wyspianskiego 27, 50-370 Wroclaw (Poland)

    2014-07-01

    Laser-induced breakdown spectroscopy (LIBS), like many other spectroscopic techniques, is a comparative method. Typically, in qualitative analysis, synthetic certified standard with a well-known elemental composition is used to calibrate the system. Nevertheless, in all laser-induced techniques, such calibration can affect the accuracy through differences in the overall composition of the chosen standard. There are also some intermediate factors, which can cause imprecision in measurements, such as optical absorption, surface structure and thermal conductivity. In this work the calibration performed for the LIBS technique utilizes pellets made directly from the tested materials (old well-characterized samples). This choice produces a considerable improvement in the accuracy of the method. This technique was adopted for the determination of trace elements in industrial copper concentrates, standardized by conventional atomic absorption spectroscopy with a flame atomizer. A series of copper flotation concentrate samples was analyzed for three elements: silver, cobalt and vanadium. We also proposed a method of post-processing the measurement data to minimize matrix effects and permit reliable analysis. It has been shown that the described technique can be used in qualitative and quantitative analyses of complex inorganic materials, such as copper flotation concentrates. It was noted that the final validation of such methodology is limited mainly by the accuracy of the characterization of the standards. - Highlights: • A laser-induced breakdown spectroscopy technique is introduced for composition monitoring in industrial copper concentrates. • Calibration samples consisted of pellets produced from the tested materials. • The proposed method of post-processing significantly minimizes matrix effects. • The possible uses of this technique are limited mainly by accurate characterization of the standard samples.

  6. Quantitative monitoring of microbial species during bioleaching of a copper concentrate

    Directory of Open Access Journals (Sweden)

    Sabrina Hedrich

    2016-12-01

    Full Text Available Monitoring of the microbial community in bioleaching processes is essential in order to control process parameters and enhance the leaching efficiency. Suitable methods are, however, limited as they are usually not adapted to bioleaching samples and often no taxon-specific assays are available in the literature for these types of consortia. Therefore, our study focused on the development of novel quantitative real-time PCR (qPCR assays for the quantification of Acidithiobacillus caldus, Leptospirillum ferriphilum, Sulfobacillus thermosulfidooxidans and Sulfobacillus benefaciens and comparison of the results with data from other common molecular monitoring methods in order to evaluate their accuracy and specificity. Stirred tank bioreactors for the leaching of copper concentrate, housing a consortium of acidophilic, moderately-thermophilic bacteria, relevant in several bioleaching operations, served as a model system. The microbial community analysis via qPCR allowed a precise monitoring of the evolution of total biomass as well as abundance of specific species. Data achieved by the standard fingerprinting methods, terminal restriction fragment length polymorphism (T-RFLP and capillary electrophoresis single strand conformation polymorphism (CE-SSCP on the same samples followed the same trend as qPCR data. The main added value of qPCR was, however, to provide quantitative data for each species whereas only relative abundance could be deduced from T-RFLP and CE-SSCP profiles. Additional value was obtained by applying two further quantitative methods which do not require nucleic acid extraction, total cell counting after SYBR Green staining and metal sulfide oxidation activity measurements via microcalorimetry. Overall, these complementary methods allow for an efficient quantitative microbial community monitoring in various bioleaching operations.

  7. Quantitative Monitoring of Microbial Species during Bioleaching of a Copper Concentrate

    Science.gov (United States)

    Hedrich, Sabrina; Guézennec, Anne-Gwenaëlle; Charron, Mickaël; Schippers, Axel; Joulian, Catherine

    2016-01-01

    Monitoring of the microbial community in bioleaching processes is essential in order to control process parameters and enhance the leaching efficiency. Suitable methods are, however, limited as they are usually not adapted to bioleaching samples and often no taxon-specific assays are available in the literature for these types of consortia. Therefore, our study focused on the development of novel quantitative real-time PCR (qPCR) assays for the quantification of Acidithiobacillus caldus, Leptospirillum ferriphilum, Sulfobacillus thermosulfidooxidans, and Sulfobacillus benefaciens and comparison of the results with data from other common molecular monitoring methods in order to evaluate their accuracy and specificity. Stirred tank bioreactors for the leaching of copper concentrate, housing a consortium of acidophilic, moderately thermophilic bacteria, relevant in several bioleaching operations, served as a model system. The microbial community analysis via qPCR allowed a precise monitoring of the evolution of total biomass as well as abundance of specific species. Data achieved by the standard fingerprinting methods, terminal restriction fragment length polymorphism (T-RFLP) and capillary electrophoresis single strand conformation polymorphism (CE-SSCP) on the same samples followed the same trend as qPCR data. The main added value of qPCR was, however, to provide quantitative data for each species whereas only relative abundance could be deduced from T-RFLP and CE-SSCP profiles. Additional value was obtained by applying two further quantitative methods which do not require nucleic acid extraction, total cell counting after SYBR Green staining and metal sulfide oxidation activity measurements via microcalorimetry. Overall, these complementary methods allow for an efficient quantitative microbial community monitoring in various bioleaching operations. PMID:28066365

  8. A Method to Determine the Ball Filling, in Miduk Copper Concentrator SAG Mill

    Directory of Open Access Journals (Sweden)

    Ali Kamali Moaveni

    2012-12-01

    Full Text Available The aim of this research work was to investigate on the ball filling estimation of Miduk semi-autogenous (SAG Mill via an utilized method. Miduk copper concentrator is located in Kerman Province, Iran, and its size reduction stage includes one gyratory crusher which feeds one SAG mill (9.75 dia.(m*3.88 length(m following two parallel ball mills (5dia.(m*7lenght(m. After SAG mill, a trommel screen produces two over and under size materials which the oversize part is circulated into SAG mill and undersize reports to hydrocyclone for further process. Ball filling identify was implemented in this work using mill`s load sampling and ball abrasion test.These methods could estimate ball filling variation with easy, undeniable, and useful tests. Also, these tests have shown the digression of operating ball filling amount and its manual designed. To make more homogenous load, mill load samplings were carried out from 6 points after whirling the mill via inching motor. Acquired load sampling results were compared with ball abrasion tests. Ball abrasion tests were calculated for 3 different conditions include maximum, average, and minimum ball abrasion. However, the calculated maximum and minimum conditions never occurred. However, these are just for obtaining to ball filling variation in the mill. The results obtained from this work show, the ball filling percentage variation is between 1.2– 3.7% which is lower than mill ball filling percentage, according to the designed conditions (15%. In addition, acquired load samplings result for mill ball filling was 1.3%.

  9. The sensitivity of stratocumulus-capped mixed layers to cloud droplet concentration: do LES and mixed-layer models agree?

    Directory of Open Access Journals (Sweden)

    P. N. Blossey

    2009-12-01

    Full Text Available The sensitivity of a stratocumulus-capped mixed layer to a change in cloud droplet concentration is evaluated with a large-eddy simulation (LES and a mixed layer model (MLM, to see if the two model types agree on the strength of the second aerosol indirect effect. Good agreement can be obtained if the MLM entrainment closure explicitly reduces entrainment efficiency proportional to the rate of cloud droplet sedimentation at cloud top for cases in which the LES-simulated boundary layer remains well mixed, with a single peak in the vertical profile of vertical velocity variance.

    To achieve this agreement, the MLM entrainment closure and the drizzle parameterization must be modified from their observationally-based defaults. This is because the LES advection scheme and microphysical parameterization significantly bias the entrainment rate and precipitation profile compared to observational best guesses. Before this modification, the MLM simulates more liquid water path and much more drizzle at a given droplet concentration than the LES and is more sensitive to droplet concentration, even undergoing a drizzle-induced boundary layer collapse at low droplet concentrations. After this modification, both models predict a similar decrease of cloud liquid water path as droplet concentration increases, cancelling 30–50% of the Twomey effect for our case. The agreement breaks down at the lowest simulated droplet concentrations, for which the boundary layer in the LES is not well mixed.

    Our results highlight issues with both types of model. Potential LES biases due to inadequate resolution, subgrid mixing and microphysics must be carefully considered when trying to make a quantitative inference of the second indirect effect from an LES of a stratocumulus-topped boundary layer. On the other hand, even slight internal decoupling of the boundary layer invalidates MLM-predicted sensitivity to droplet concentrations.

  10. Evaluation of the laser-induced breakdown spectroscopy technique for determination of the chemical composition of copper concentrates

    Science.gov (United States)

    Łazarek, Łukasz; Antończak, Arkadiusz J.; Wójcik, Michał R.; Drzymała, Jan; Abramski, Krzysztof M.

    2014-07-01

    Laser-induced breakdown spectroscopy (LIBS), like many other spectroscopic techniques, is a comparative method. Typically, in qualitative analysis, synthetic certified standard with a well-known elemental composition is used to calibrate the system. Nevertheless, in all laser-induced techniques, such calibration can affect the accuracy through differences in the overall composition of the chosen standard. There are also some intermediate factors, which can cause imprecision in measurements, such as optical absorption, surface structure and thermal conductivity. In this work the calibration performed for the LIBS technique utilizes pellets made directly from the tested materials (old well-characterized samples). This choice produces a considerable improvement in the accuracy of the method. This technique was adopted for the determination of trace elements in industrial copper concentrates, standardized by conventional atomic absorption spectroscopy with a flame atomizer. A series of copper flotation concentrate samples was analyzed for three elements: silver, cobalt and vanadium. We also proposed a method of post-processing the measurement data to minimize matrix effects and permit reliable analysis. It has been shown that the described technique can be used in qualitative and quantitative analyses of complex inorganic materials, such as copper flotation concentrates. It was noted that the final validation of such methodology is limited mainly by the accuracy of the characterization of the standards.

  11. Combined effects of temperature and copper ion concentration on the superoxide dismutase activity inCrassostrea ariakensis

    Institute of Scientific and Technical Information of China (English)

    WANG Hui; YANG Hongshuai; LIU Jiahui; LI Yanhong; LIU Zhigang

    2016-01-01

    Superoxide dismutase (SOD) is a crucial antioxidant enzyme playing the first defense line in antioxidant pathways against reactive oxygen species in various organisms including marine invertebrates. There exist mainly two specific forms, Cu/Zn-SOD (SOD1) and Mn-SOD (SOD2), in eukaryotes. SODs are known to be concurrently modulated by a variety of environmental stressors. By using central composite experimental design and response surface method, the joint effects of water temperature (18–34°C) and copper ion concentration (0.1–1.5 mg/L) on the total SOD activity in the digestive gland ofCrassostrea ariakensis were studied. The results showed that the linear effect of temperature was highly significant (P0.05), while the quadratic effect of copper ion concentration was highly significant (P0.05); the effect of temperature was greater than that of copper ion concentration. The model equation of digestive gland SOD enzyme activity towards the two factors of interest was established, withR2 and predictiveR2 as high as 0.961 6 and 0.820 7, respectively, suggesting that the goodness-of-fit to experimental data be very satisfactory, and could be applied to prediction of digestive gland SOD activity in C. ariakensis under the conditions of the experiment. Our results would be conducive to addressing the health of aquatic animals and/or to detecting environmental problems by taking SOD as a potential bioindicator.

  12. Aircraft observations and model simulations of concentration and particle size distribution in the Eyjafjallajökull volcanic ash cloud

    Science.gov (United States)

    Dacre, H. F.; Grant, A. L. M.; Johnson, B. T.

    2013-02-01

    The Eyjafjallajökull volcano in Iceland emitted a cloud of ash into the atmosphere during April and May 2010. Over the UK the ash cloud was observed by the FAAM BAe-146 Atmospheric Research Aircraft which was equipped with in-situ probes measuring the concentration of volcanic ash carried by particles of varying sizes. The UK Met Office Numerical Atmospheric-dispersion Modelling Environment (NAME) has been used to simulate the evolution of the ash cloud emitted by the Eyjafjallajökull volcano during the period 4-18 May 2010. In the NAME simulations the processes controlling the evolution of the concentration and particle size distribution include sedimentation and deposition of particles, horizontal dispersion and vertical wind shear. For travel times between 24 and 72 h, a 1/t relationship describes the evolution of the concentration at the centre of the ash cloud and the particle size distribution remains fairly constant. Although NAME does not represent the effects of microphysical processes, it can capture the observed decrease in concentration with travel time in this period. This suggests that, for this eruption, microphysical processes play a small role in determining the evolution of the distal ash cloud. Quantitative comparison with observations shows that NAME can simulate the observed column-integrated mass if around 4% of the total emitted mass is assumed to be transported as far as the UK by small particles (< 30 μm diameter). NAME can also simulate the observed particle size distribution if a distal particle size distribution that contains a large fraction of < 10 μm diameter particles is used, consistent with the idea that phraetomagmatic volcanoes, such as Eyjafjallajökull, emit very fine particles.

  13. Aircraft observations and model simulations of concentration and particle size distribution in the Eyjafjallajökull volcanic ash cloud

    Directory of Open Access Journals (Sweden)

    H. F. Dacre

    2013-02-01

    Full Text Available The Eyjafjallajökull volcano in Iceland emitted a cloud of ash into the atmosphere during April and May 2010. Over the UK the ash cloud was observed by the FAAM BAe-146 Atmospheric Research Aircraft which was equipped with in-situ probes measuring the concentration of volcanic ash carried by particles of varying sizes. The UK Met Office Numerical Atmospheric-dispersion Modelling Environment (NAME has been used to simulate the evolution of the ash cloud emitted by the Eyjafjallajökull volcano during the period 4–18 May 2010. In the NAME simulations the processes controlling the evolution of the concentration and particle size distribution include sedimentation and deposition of particles, horizontal dispersion and vertical wind shear. For travel times between 24 and 72 h, a 1/t relationship describes the evolution of the concentration at the centre of the ash cloud and the particle size distribution remains fairly constant. Although NAME does not represent the effects of microphysical processes, it can capture the observed decrease in concentration with travel time in this period. This suggests that, for this eruption, microphysical processes play a small role in determining the evolution of the distal ash cloud. Quantitative comparison with observations shows that NAME can simulate the observed column-integrated mass if around 4% of the total emitted mass is assumed to be transported as far as the UK by small particles (< 30 μm diameter. NAME can also simulate the observed particle size distribution if a distal particle size distribution that contains a large fraction of < 10 μm diameter particles is used, consistent with the idea that phraetomagmatic volcanoes, such as Eyjafjallajökull, emit very fine particles.

  14. Aircraft observations and model simulations of concentration and particle size distribution in the Eyjafjallajökull volcanic ash cloud

    Directory of Open Access Journals (Sweden)

    H. F. Dacre

    2012-09-01

    Full Text Available The Eyjafjallajökull volcano in Iceland emitted a cloud of ash into the atmosphere during April and May 2010. Over the UK the ash cloud was observed by the FAAM BAe-146 Atmospheric Research Aircraft which was equipped with in-situ probes measuring the concentration of volcanic ash carried by particles of varying sizes. The UK Met Office Numerical Atmospheric-dispersion Modelling Environment (NAME has been used to simulate the evolution of the ash cloud emitted by the Eyjafjallajökull volcano during the period 4–18 May 2010. In the NAME simulations the processes controlling the evolution of the concentration and particle size distribution include sedimentation and deposition of particles, horizontal dispersion and vertical wind shear. For travel times between 24 and 72 h a 1/t relationship describes the evolution of the concentration at the centre of the ash cloud and the particle size distribution remains fairly constant. Although NAME does not represent the effects of microphysical processes it can capture the observed decrease in concentration with travel time in this period. This suggests that, for this eruption, microphysical processes play a small role in determining the evolution of the distal ash cloud. Quantitative comparison with observations shows that NAME can simulate the observed column integrated mass if around 4% of the total emitted mass is assumed to be transported as far as the UK by small (<30 m diameter particles. NAME can also simulate the observed particle size distribution if a distal particle size distribution that contains a large fraction of <10 m diameter particles is used, consistent with the idea that phraetomagmatic volcanoes, such as Eyjafjallajökull, emit very fine particles.

  15. Spray pyrolysed Cu2ZnSnS4/In2S3 thin film solar cell: Effect of varying copper concentration on cell parameters

    Science.gov (United States)

    Menon, M. R. Rajesh; Rajeshmon, V. G.; Thomas, Titu; Kartha, C. Sudha; Vijayakumar, K. P.

    2016-05-01

    A double layer Cu2ZnSnS4 absorber was employed for the first time to improve the performance of spray pyrolysed Cu2ZnSnS4/In2S3 thin film solar cell. Copper concentration in the two layers of Cu2ZnSnS4 was adjusted and effect on performance parameters was studied. It was observed that higher copper concentration in the absorber layer adjacent to the electrode is beneficial for device performance, whereas, lower copper concentration in absorber layer near to the junction has detrimental effect on the device properties.

  16. Determination of trace copper in plastic by cloud point extraction-atomic absorption spectrometry%浊点萃取-原子吸收光谱法测定塑料中的痕量铜

    Institute of Scientific and Technical Information of China (English)

    黄海霞; 王秀峰; 吴旭宇; 肖慈燕

    2013-01-01

    A novel method of cloud point extraction-atomic absorption spectrometry based on using PAN as a complexant and Triton X-100 as an extractant, was developed for determination of copper in food preservation. The effects of the pH of solution, concentrations of complexant and surfactant, equilibrium temperature and time on the efficiency of cloud point extraction have been systematically examined. Under the optimized conditions, the linear equation was Y -0. 1049Z +0. 0016, the correlation coefficient was 0. 9988, the detection limit was 0. 7 μg/L the relative standard deviation was 2. 3% , and the enrichment factor was 15. This method was applied to the determination of trace copper in plastic products, and the recovery were 97. 5% ~101. 9%.%建立了以1-(2-吡啶偶氮)-2-萘酚(PAN)为络合剂、Triton X-100为表面活性剂的浊点萃取-原子吸收光谱法测定痕量铜的分析方法.探讨了溶液的pH、络合剂和表面活性剂用量、平衡温度和平衡时间等因素对浊点萃取的影响.最佳条件下,线性方程为Y=0.1049X +0.0016,相关系数为0.9988,检出限为0.7 μg/L,相对偏差为2.3%,富集倍数为15倍.用该方法对几种塑料制品中的痕量铜进行测定,回收率为97.5% ~ 101.9%.

  17. Copper transport.

    Science.gov (United States)

    Linder, M C; Wooten, L; Cerveza, P; Cotton, S; Shulze, R; Lomeli, N

    1998-05-01

    In adult humans, the net absorption of dietary copper is approximately 1 mg/d. Dietary copper joins some 4-5 mg of endogenous copper flowing into the gastrointestinal tract through various digestive juices. Most of this copper returns to the circulation and to the tissues (including liver) that formed them. Much lower amounts of copper flow into and out of other major parts of the body (including heart, skeletal muscle, and brain). Newly absorbed copper is transported to body tissues in two phases, borne primarily by plasma protein carriers (albumin, transcuprein, and ceruloplasmin). In the first phase, copper goes from the intestine to the liver and kidney; in the second phase, copper usually goes from the liver (and perhaps also the kidney) to other organs. Ceruloplasmin plays a role in this second phase. Alternatively, liver copper can also exit via the bile, and in a form that is less easily reabsorbed. Copper is also present in and transported by other body fluids, including those bathing the brain and central nervous system and surrounding the fetus in the amniotic sac. Ceruloplasmin is present in these fluids and may also be involved in copper transport there. The concentrations of copper and ceruloplasmin in milk vary with lactational stage. Parallel changes occur in ceruloplasmin messenger RNA expression in the mammary gland (as determined in pigs). Copper in milk ceruloplasmin appears to be particularly available for absorption, at least in rats.

  18. 浅析大数据及云计算在铜冶金行业中的应用%Discussion on the application of big data and cloud computing in copper metallurgy industry

    Institute of Scientific and Technical Information of China (English)

    刘坤

    2015-01-01

    本文对大数据和云计算的概念进行了概述,阐述了大数据和云计算对铜冶金发展的重要性。%The concepts of big data and cloud computing in this paper are reviewed,and the importance of big data and cloud computing to copper metallurgy development is also discussed.

  19. High-concentration copper nanoparticles synthesis process for screen-printing conductive paste on flexible substrate

    Science.gov (United States)

    Tam, Sze Kee; Ng, Ka Ming

    2015-12-01

    This study presents a method for the synthesis of copper nanoparticles, which are poised to replace silver nanoparticles in some application areas of printed electronics. This method offers three advantages. Firstly, copper loading in the synthesis reaction can be as high as 1 M, offering high productivity in large-scale production. Secondly, the size of the copper nanoparticles can be controlled from 12 to 99 nm. Thirdly, the surface polarity of the particles can be modified. Thus, a tailor-made product can be synthesized. The synthesis of copper nanoparticles coated with various capping agents, including dodecanethiol, lauric acid, nonanoic acid, polyacrylic acid, and polyvinyl pyrrolidone, was demonstrated. The nonanoic acid-coated copper nanoparticles were formulated as a screen-printing conductive paste. The particles were readily dispersed in terpineol, and the paste could be screen printed onto flexible polyester. The electrical resistivity of patterns after a low-temperature (120 °C) sintering treatment was around 5.8 × 10-5 Ω cm.

  20. High-concentration copper nanoparticles synthesis process for screen-printing conductive paste on flexible substrate

    Energy Technology Data Exchange (ETDEWEB)

    Tam, Sze Kee; Ng, Ka Ming, E-mail: kekmng@ust.hk [The Hong Kong University of Science and Technology, Department of Chemical and Biomolecular Engineering (Hong Kong)

    2015-12-15

    This study presents a method for the synthesis of copper nanoparticles, which are poised to replace silver nanoparticles in some application areas of printed electronics. This method offers three advantages. Firstly, copper loading in the synthesis reaction can be as high as 1 M, offering high productivity in large-scale production. Secondly, the size of the copper nanoparticles can be controlled from 12 to 99 nm. Thirdly, the surface polarity of the particles can be modified. Thus, a tailor-made product can be synthesized. The synthesis of copper nanoparticles coated with various capping agents, including dodecanethiol, lauric acid, nonanoic acid, polyacrylic acid, and polyvinyl pyrrolidone, was demonstrated. The nonanoic acid-coated copper nanoparticles were formulated as a screen-printing conductive paste. The particles were readily dispersed in terpineol, and the paste could be screen printed onto flexible polyester. The electrical resistivity of patterns after a low-temperature (120 °C) sintering treatment was around 5.8 × 10{sup −5} Ω cm.Graphical Abstract.

  1. Simultaneous preconcentration of copper and mercury in water samples by cloud point extraction and their determination by inductively coupled plasma atomic emission spectrometry

    Science.gov (United States)

    Shoaee, Hamta; Roshdi, Mina; Khanlarzadeh, Nasibeh; Beiraghi, Asadollah

    2012-12-01

    A cloud-point extraction process coupled to ICP-OES by using 3-nitro benzaldehyde thiosemicarbazone (3-NBT) as complexing agent was developed for the simultaneous preconcentration and determination of copper and mercury in water samples. The variables affecting the complexation and extraction steps were optimized. Under the optimum conditions (i.e. 1.5 × 10-5 mol L-1 ligand, 0.3% (v/v) Triton X-114, 55 °C equilibrium temperature, incubation time of 30 min) the calibration graphs were linear in the range of 5-120 and 10-100 ng mL-1 with enhancement factor of 82.7 and 51.3 for Cu2+ and Hg2+, respectively. The preconcentration factors were 28.6 in both cases and detection limits were obtained 0.48 for Cu and 1.1 ng mL-1 for Hg. The precisions (R.S.D.%) for five replicate determinations at 50 ng mL-1 of copper and mercury were better than 1.8% and 3.2%, respectively. The accuracy of the proposed method is validated by analyzing a certified reference material of water (RTC-QCI-049) with satisfactory results. Finally, the proposed method was utilized successfully for the determination of copper and mercury in surface water (river), tap water and bottled mineral water samples.

  2. Simultaneous preconcentration of copper and mercury in water samples by cloud point extraction and their determination by inductively coupled plasma atomic emission spectrometry.

    Science.gov (United States)

    Shoaee, Hamta; Roshdi, Mina; Khanlarzadeh, Nasibeh; Beiraghi, Asadollah

    2012-12-01

    A cloud-point extraction process coupled to ICP-OES by using 3-nitro benzaldehyde thiosemicarbazone (3-NBT) as complexing agent was developed for the simultaneous preconcentration and determination of copper and mercury in water samples. The variables affecting the complexation and extraction steps were optimized. Under the optimum conditions (i.e. 1.5×10(-5) mol L(-1) ligand, 0.3% (v/v) Triton X-114, 55 °C equilibrium temperature, incubation time of 30 min) the calibration graphs were linear in the range of 5-120 and 10-100 ng mL(-1) with enhancement factor of 82.7 and 51.3 for Cu(2+) and Hg(2+), respectively. The preconcentration factors were 28.6 in both cases and detection limits were obtained 0.48 for Cu and 1.1 ng mL(-1) for Hg. The precisions (R.S.D.%) for five replicate determinations at 50 ng mL(-1) of copper and mercury were better than 1.8% and 3.2%, respectively. The accuracy of the proposed method is validated by analyzing a certified reference material of water (RTC-QCI-049) with satisfactory results. Finally, the proposed method was utilized successfully for the determination of copper and mercury in surface water (river), tap water and bottled mineral water samples.

  3. Nanoscale surface characterization of aqueous copper corrosion: Effects of immersion interval and orthophosphate concentration

    Energy Technology Data Exchange (ETDEWEB)

    Daniels, Stephanie L. [Department of Chemistry, Louisiana State University, Baton Rouge, LA 70803 (United States); United States Environmental Protection Agency, National Risk Management Research Laboratory (NRMRL), Water Supply and Water Resource Division (WSWRD), Cincinnati, OH 45268 (United States); Sprunger, Phillip T. [Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 70803 (United States); Center for Advanced Microstructures and Devices, Synchrotron Radiation Facility of Louisiana State University, Baton Rouge, LA 70803 (United States); Kizilkaya, Orhan [Center for Advanced Microstructures and Devices, Synchrotron Radiation Facility of Louisiana State University, Baton Rouge, LA 70803 (United States); Lytle, Darren A. [United States Environmental Protection Agency, National Risk Management Research Laboratory (NRMRL), Water Supply and Water Resource Division (WSWRD), Cincinnati, OH 45268 (United States); Garno, Jayne C., E-mail: jgarno@lsu.edu [Department of Chemistry, Louisiana State University, Baton Rouge, LA 70803 (United States)

    2013-11-15

    Morphology changes for copper surfaces exposed to different water parameters were investigated at the nanoscale with atomic force microscopy (AFM), as influenced by changes in pH and the levels of orthophosphate ions. Synthetic water samples were designed to mimic physiological chemistries for drinking water, both with and without addition of orthophosphate over a pH range 6.5–9. Copper surfaces treated with orthophosphate as a corrosion inhibitor after 6 and 24 h were evaluated. Tapping mode AFM images revealed dosing of the water with 6 mg/L of orthophosphate was beneficial in retarding the growth of copper by-products. The chemical composition and oxidation state of the surface deposits were characterized with X-ray diffraction (XRD), near edge X-ray absorption fine structure (NEXAFS) spectroscopy and Fourier transform infrared spectroscopy (FTIR).

  4. Studies on the effects of x-ray on erythrocyte zinc and copper concentrations in rabbits after treatment with antioxidants.

    Science.gov (United States)

    Dede, S; Deger, Y; Mert, N; Kahraman, T; Alkan, M; Keles, I

    2003-04-01

    The aim of this study was to investigate the effect of supplemental antioxidant vitamins and minerals on the erythrocyte concentrations of zinc and copper in rabbits after exposure to X-rays. The animals were divided into two experimental and one control group (CG). The first group (VG) was given daily oral doses of vitamins E and C; supplemental amounts of manganese, zinc, and copper were mixed with the feed and given to the second group of experimental animals (MG). Blood samples were taken from all groups before and after 4 wk of vitamin and mineral administration and after irradiation with a total dose of 550-rad X-rays. The administration of minerals caused the most significant increases of Zn and Cu. Even after irradiation, the zinc levels in the irradiated animals were higher than in the nonirradiated vitamin-supplemented animals (pvitamins and minerals may have a protective effect against X-ray-induced damage.

  5. The effect of copper concentration on structural, optical and dielectric properties of Cu xZn 1 - xS thin films

    Science.gov (United States)

    Ali Yıldırım, M.

    2012-03-01

    Cu xZn 1 - xS ( x = 0, 0.25, 0.50, 0.75, 1) thin films were deposited on glass substrates using Successive Ionic Layer Adsorption and Reaction (SILAR) method at room temperature and ambient pressure. The copper concentration ( x) effect on the structural, morphological and optical properties of Cu xZn 1 - xS thin films was investigated. The X-ray diffraction (XRD) and scanning electron microscopy (SEM) studies showed that all the films exhibit polycrystalline nature and are covered well with glass substrates. The crystalline and surface properties of the films improved with increasing copper concentration. The energy bandgap values were changed from 2.07 to 3.67 eV depending on the copper concentration. The refractive index ( n), optical static and high frequency dielectric constants ( ɛo, ɛ∞) values were calculated by using the energy bandgap values as a function of the copper concentration.

  6. Certification for copper concentration in reference material for fuel anhydro ethylic alcohol; Certificacao da concentracao de cobre em material de referencia para alcool etilico anidro combustivel (AEC)

    Energy Technology Data Exchange (ETDEWEB)

    Reis, Lindomar Augusto dos; Rocha, Marcia Silva da; Mesko, Marcia Foster; Silva, Fagner Francisco da; Quaresma, Maria Cristina Baptista; Araujo, Thiago Oliveira [Instituto Nacional de Metrologia, Normalizacao e Qualidade Industrial (DIMCI/INMETRO), Duque de Caxias, RJ (Brazil). Diretoria de Metrologia Cientifica e Industrial], E-mail: lareis@inmetro.gov.br

    2009-07-01

    This work aiming to obtain the first certified reference material for fuel anhydro ethylic alcohol relative to the copper concentration, which has his maximum limit determined by the in force legislation providing traceability and reliability for the measurement results.

  7. Urinary excretion of copper, zinc and iron with and without D-penicillamine administration in relation to hepatic copper concentration in dogs

    NARCIS (Netherlands)

    Fieten, H.; Hugen, S.; Ingh, van den T.S.G.A.M.; Hendriks, W.H.; Vernooij, J.C.M.; Bode, P.; Watson, A.L.; Leegwater, P.A.J.; Rothuizen, J.

    2013-01-01

    Hereditary copper-associated hepatitis in dogs resembles Wilson’s disease, a copper storage disease in humans. Values for urinary copper excretion are well established in the diagnostic protocol of Wilson’s disease, whereas in dogs these have not been evaluated. The objectives of this study were to

  8. Urinary excretion of copper, zinc and iron with and without D-penicillamine administration in relation to hepatic copper concentration in dogs

    NARCIS (Netherlands)

    Fieten, H.; Hugen, S.; van den Ingh, T.S.G.A.M.; Hendriks, W.H.; Vernooij, Hans; Bode, P.; Watson, A.L.; Leegwater, P.A.J.; Rothuizen, J.

    2013-01-01

    Abstract Hereditary copper-associated hepatitis in dogs resembles Wilson’s disease, a copper storage disease in humans. Values for urinary copper excretion are well established in the diagnostic protocol of Wilson’s disease, whereas in dogs these have not been evaluated. The objectives of this study

  9. Urinary excretion of copper, zinc and iron with and without D-penicillamine administration in relation to hepatic copper concentration in dogs

    NARCIS (Netherlands)

    Fieten, H.; Hugen, S.; van den Ingh, T.S.G.A.M.; Hendriks, W.H.; Vernooij, Hans; Bode, P.; Watson, A.L.; Leegwater, P.A.J.; Rothuizen, J.

    2013-01-01

    Abstract Hereditary copper-associated hepatitis in dogs resembles Wilson’s disease, a copper storage disease in humans. Values for urinary copper excretion are well established in the diagnostic protocol of Wilson’s disease, whereas in dogs these have not been evaluated. The objectives of this study

  10. Urinary excretion of copper, zinc and iron with and without D-penicillamine administration in relation to hepatic copper concentration in dogs

    NARCIS (Netherlands)

    Fieten, H.; Hugen, S.; Ingh, van den T.S.G.A.M.; Hendriks, W.H.; Vernooij, J.C.M.; Bode, P.; Watson, A.L.; Leegwater, P.A.J.; Rothuizen, J.

    2013-01-01

    Hereditary copper-associated hepatitis in dogs resembles Wilson’s disease, a copper storage disease in humans. Values for urinary copper excretion are well established in the diagnostic protocol of Wilson’s disease, whereas in dogs these have not been evaluated. The objectives of this study were to

  11. Nanoscale Surface Characterization of Aqueous Copper Corrosion: Effects of Immersion Interval and Orthophosphate Concentration

    Science.gov (United States)

    Morphology changes for copper surfaces exposed to different water parameters were investigated at the nanoscale with atomic force microscopy (AFM), as influenced by changes in pH and the levels of orthophosphate ions. Synthetic water samples were designed to mimic physiological c...

  12. The sensitivity of stratocumulus-capped mixed layers to cloud droplet concentration: do LES and mixed-layer models agree?

    Directory of Open Access Journals (Sweden)

    J. Uchida

    2010-05-01

    Full Text Available The sensitivity of a stratocumulus-capped mixed layer to a change in cloud droplet concentration is evaluated with a large-eddy simulation (LES and a mixed layer model (MLM. The strength of the second aerosol indirect effect simulated by the two model types agrees within 50% for cases in which the LES-simulated boundary layer remains well mixed, if the MLM entrainment closure includes the effects of cloud droplet sedimentation.

    To achieve this agreement, parameters in the MLM entrainment closure and the drizzle parameterization must be retuned to match the LES. This is because the LES advection scheme and microphysical parameterization significantly bias the entrainment rate and precipitation profile compared to observational best guesses. Before this modification, the MLM simulates more liquid water path and much more drizzle at a given droplet concentration than the LES and is more sensitive to droplet concentration, even undergoing a drizzle-induced boundary layer collapse at low droplet concentrations. After this modification, both models predict a comparable decrease of cloud liquid water path as droplet concentration increases, cancelling 30–50% of the Twomey effect for our case. The agreement breaks down at the lowest simulated droplet concentrations, for which the boundary layer in the LES is not well mixed.

    Our results highlight issues with both types of model. Potential LES biases due to inadequate resolution, subgrid mixing and parameterized microphysics must be carefully considered when trying to make a quantitative inference of the second indirect effect from an LES of a stratocumulus-topped boundary layer. On the other hand, even slight internal decoupling of the boundary layer invalidates the central assumption of an MLM, substantially limiting the range of conditions that MLM-predicted sensitivities to droplet concentration are meaningful.

  13. Concentration of copper, iron, zinc, cadmium, lead, and nickel in boar semen and relation to the spermatozoa quality.

    Science.gov (United States)

    Massányi, Peter; Trandzík, Jozef; Nad, Pavol; Koréneková, Beáta; Skalická, Magdaléna; Toman, Robert; Lukác, Norbert; Strapák, Peter; Halo, Marko; Turcan, Ján

    2003-01-01

    The concentration of copper, iron, zinc, cadmium, lead, and nickel as well as its relation to spermatozoa quality was investigated. The semen samples were analyzed by atomic absorption spectrophotometry (AAS). The concentration of copper in boar semen was 1.64 +/- 0.28 mg kg(-1) and of iron 16.14 +/- 10.35 mg kg(-1). The concentration of zinc in boar semen reached an average value of 171.74 +/- 64.72 mg kg(-1) and the level of cadmium reached 0.01-0.16 mg kg(-1) with the average value of 0.05 mg kg(-1). The analysis of lead showed that the concentration of this element in boar semen was 0.02 +/- 0.03 mg kg(-1) and the average level of nickel was 0.06 +/- 0.08 mg kg(-1). The total percentage of pathological spermatozoa was 9.82 +/- 1.47%. Detail analysis determined 3.18% of separated flagellum, 2.26% knob twisted flagellum, 0.88% flagellum torso, 0.85% flagellum ball, 0.42% broken flagellum, 0.23% retention of the cytoplasmic drop, 0.14% small heads, 0.03% large heads, and 1.83% forms other of pathological changes. Correlation analysis showed significant (p spermatozoa (r = 0.73) was determined.

  14. Serum Concentration of Zinc, Copper, Selenium, Manganese, and Cu/Zn Ratio in Children and Adolescents with Myopia.

    Science.gov (United States)

    Fedor, Monika; Socha, Katarzyna; Urban, Beata; Soroczyńska, Jolanta; Matyskiela, Monika; Borawska, Maria H; Bakunowicz-Łazarczyk, Alina

    2017-03-01

    The purpose of the present study was the assessment of the serum concentration of antioxidant microelements-zinc, copper, selenium, manganese, and Cu/Zn ratio in children and adolescents with myopia. Eighty-three children were examined (mean age 14.36 ± 2.49 years) with myopia. The control group was 38 persons (mean age 12.89 ± 3.84 years). Each patient had complete eye examination. The serum concentration of zinc, copper, manganese, and selenium was determined by atomic absorption spectrometry. Cu/Zn ratio, which is the indicator of the oxidative stress, was also calculated. The average serum concentration of zinc in myopic patients was significantly lower (0.865 ± 0.221 mg L(-1)) in comparison to the control group (1.054 ± 0.174 mg L(-1)). There was significantly higher Cu/Zn ratio in myopic patients (1.196 ± 0.452) in comparison to that in the control group (0.992 ± 0.203). The average serum concentration of selenium in the study group was significantly lower (40.23 ± 12.07 μg L(-1)) compared with that in the control group (46.00 ± 12.25 μg L(-1)). There were no essential differences between serum concentration of copper and manganese in the study group and the control group. Low serum concentration of zinc and selenium in myopic children may imply an association between insufficiency of these antioxidant microelements and the development of the myopia and could be the indication for zinc and selenium supplementation in the prevention of myopia. Significantly, higher Cu/Zn ratio in the study group can suggest the relationship between myopia and oxidative stress.

  15. Synovial fluid and plasma selenium, copper, zinc, and iron concentrations in patients with rheumatoid arthritis and osteoarthritis.

    Science.gov (United States)

    Yazar, M; Sarban, S; Kocyigit, A; Isikan, U E

    2005-08-01

    In recent years, a great number of studies have investigated the possible role of trace elements in the etiology and pathogenesis of rheumatoid arthritis (RA) and osteoartritis (OA). We studied synovial fluid and plasma concentrations of selenium (Se), zinc (Zn), copper (Cu), and iron (Fe) in patients with RA and OA and compared them with sex- and age-matched healthy subjects. Plasma albumin levels were measured as an index of nutritional status. Plasma Se, Cu, and Zn concentrations were determined by atomic absorption spectrophotometry and Fe concentrations were determined by the colorimetric method. Although plasma and synovial fluid Se concentration were found to be significantly lower (p 0.05). On the other hand, synovial fluid Cu and Fe concentrations were significantly higher in patients with OA than those of healthy subjects (p < 0.05). There was a significantly positive correlation between synovial fluid Se-Cu values and Zn-Fe values in patients with RA. Our results showed that synovial fluid and plasma trace element concentrations, excluding Zn, change in inflammatory RA, but not in OA. These alterations in trace element concentrations in inflammatory RA might be a result of the changes of the immunoregulatory cytokines.

  16. Residual stress in copper containing a high concentration of krypton precipitates

    Energy Technology Data Exchange (ETDEWEB)

    Haerting, M.; Yaman, M.; Bucher, R.; Britton, D.T. [Department of Physics, University of Cape Town, Rondebosch 7701 (South Africa)

    2002-08-01

    A study of the residual stress and bubble pressure in bulk samples of copper, containing 3 at.-% krypton, using X-ray diffraction techniques is presented here. The authors have confirmed that the Kr forms solid precipitates with an fcc structure, which is consistent with an estimated pressure of 2.4 GPa. Stress measurements in the surrounding Cu matrix indicate a zero normal stress, confirming that the matrix experiences only a shear strain. The magnitude of the shear stress is estimated from the bubble pressure to be below the yield stress of the matrix, thus explaining the long term stability of the bubbles. (Abstract Copyright[2002], Wiley Periodicals, Inc.)

  17. Application of dual-cloud point extraction for the trace levels of copper in serum of different viral hepatitis patients by flame atomic absorption spectrometry: a multivariate study.

    Science.gov (United States)

    Arain, Salma Aslam; Kazi, Tasneem G; Afridi, Hassan Imran; Abbasi, Abdul Rasool; Panhwar, Abdul Haleem; Naeemullah; Shanker, Bhawani; Arain, Mohammad Balal

    2014-12-10

    An efficient, innovative preconcentration method, dual-cloud point extraction (d-CPE) has been developed for the extraction and preconcentration of copper (Cu(2+)) in serum samples of different viral hepatitis patients prior to couple with flame atomic absorption spectrometry (FAAS). The d-CPE procedure was based on forming complexes of elemental ions with complexing reagent 1-(2-pyridylazo)-2-naphthol (PAN), and subsequent entrapping the complexes in nonionic surfactant (Triton X-114). Then the surfactant rich phase containing the metal complexes was treated with aqueous nitric acid solution, and metal ions were back extracted into the aqueous phase, as second cloud point extraction stage, and finally determined by flame atomic absorption spectrometry using conventional nebulization. The multivariate strategy was applied to estimate the optimum values of experimental variables for the recovery of Cu(2+) using d-CPE. In optimum experimental conditions, the limit of detection and the enrichment factor were 0.046μgL(-1) and 78, respectively. The validity and accuracy of proposed method were checked by analysis of Cu(2+) in certified sample of serum (CRM) by d-CPE and conventional CPE procedure on same CRM. The proposed method was successfully applied to the determination of Cu(2+) in serum samples of different viral hepatitis patients and healthy controls.

  18. Application of dual-cloud point extraction for the trace levels of copper in serum of different viral hepatitis patients by flame atomic absorption spectrometry: A multivariate study

    Science.gov (United States)

    Arain, Salma Aslam; Kazi, Tasneem G.; Afridi, Hassan Imran; Abbasi, Abdul Rasool; Panhwar, Abdul Haleem; Naeemullah; Shanker, Bhawani; Arain, Mohammad Balal

    2014-12-01

    An efficient, innovative preconcentration method, dual-cloud point extraction (d-CPE) has been developed for the extraction and preconcentration of copper (Cu2+) in serum samples of different viral hepatitis patients prior to couple with flame atomic absorption spectrometry (FAAS). The d-CPE procedure was based on forming complexes of elemental ions with complexing reagent 1-(2-pyridylazo)-2-naphthol (PAN), and subsequent entrapping the complexes in nonionic surfactant (Triton X-114). Then the surfactant rich phase containing the metal complexes was treated with aqueous nitric acid solution, and metal ions were back extracted into the aqueous phase, as second cloud point extraction stage, and finally determined by flame atomic absorption spectrometry using conventional nebulization. The multivariate strategy was applied to estimate the optimum values of experimental variables for the recovery of Cu2+ using d-CPE. In optimum experimental conditions, the limit of detection and the enrichment factor were 0.046 μg L-1 and 78, respectively. The validity and accuracy of proposed method were checked by analysis of Cu2+ in certified sample of serum (CRM) by d-CPE and conventional CPE procedure on same CRM. The proposed method was successfully applied to the determination of Cu2+ in serum samples of different viral hepatitis patients and healthy controls.

  19. Adsorption of low concentration ceftazidime from aqueous solutions using impregnated activated carbon promoted by Iron, Copper and Aluminum

    Science.gov (United States)

    Hu, Xiang; Zhang, Hua; Sun, Zhirong

    2017-01-01

    In this paper, three impregnated activated carbon IAC (AC-Cu, AC-Fe, and AC-Al) promoted by Iron, Copper and Aluminum were used for adsorption of ceftazidime. Iron(III), Copper(II) and Aluminum(III) nitrate were used as an impregnant. The IACs were characterized by scanning electron microscope (SEM), Brunauer-Emmett-Teller (BET) surface area analyzer, Fourier transform infrared spectroscopy (FTIR) and X-ray Photoelectron Spectroscopy (XPS).The influence of factors, such as ion strength, pH, temperature, initial concentration, and concentration of natural organic matter organic matter on the adsorption process were studied. The adsorption kinetics and isotherms of ceftazidime were studied for the three IACs. The results showed that the adsorption was accurately represented by pseudo-second order model. Under different temperature, the maximum adsorption quantity of ceftazidime on AC-Cu calculated by pseudo-second order kinetic model were 200.0 mg g-1 (298 K), 196.1 mg g-1 (303 K) and 185.2 mg g-1 (308 K). It was much higher than that of AC-Fe and AC-Al. And the process was controlled by both film diffusion and intra particle mass transport. The results also showed that, the Freundlich and Temkin isotherm fit the adsorption well.

  20. Effect of copper oxide concentration on the formation and persistency of environmentally persistent free radicals (EPFRs) in particulates.

    Science.gov (United States)

    Kiruri, Lucy W; Khachatryan, Lavrent; Dellinger, Barry; Lomnicki, Slawo

    2014-02-18

    Environmentally persistent free radicals (EPFRs) are formed by the chemisorption of substituted aromatics on metal oxide surfaces in both combustion sources and superfund sites. The current study reports the dependency of EPFR yields and their persistency on metal loading in particles (0.25, 0.5, 0.75, 1, 2, and 5% CuO/silica). The EPFRs were generated through exposure of particles to three adsorbate vapors at 230 °C: phenol, 2-monochlorophenol (2-MCP), and dichlorobenzene (DCBz). Adsorption resulted in the formation of surface-bound phenoxyl- and semiquinoine-type radicals with characteristic EPR spectra displaying a g value ranging from ∼ 2.0037 to 2.006. The highest EPFR yield was observed for CuO concentrations between 1 and 3% in relation to MCP and phenol adsorption. However, radical density, which is expressed as the number of radicals per copper atom, was highest at 0.75-1% CuO loading. For 1,2-dichlorobenzene adsorption, radical concentration increased linearly with decreasing copper content. At the same time, a qualitative change in the radicals formed was observed--from semiquinone to chlorophenoxyl radicals. The two longest lifetimes, 25 and 23 h, were observed for phenoxyl-type radicals on 0.5% CuO and chlorophenoxyl-type radicals on 0.75% CuO, respectively.

  1. The Smelting Method of Blister Copperout of Copper Sulifde Concentrate%一种从硫化铜精矿中冶炼粗铜的方法

    Institute of Scientific and Technical Information of China (English)

    刘刚

    2016-01-01

    介绍了一种从硫化铜精矿中冶炼粗铜的方法,使用氧气顶吹转炉冶炼,对硫化铜精矿进行闪速熔炼产出铜锍,对铜锍采用空气吹炼产出粗铜。本方法设备投资小,工艺流程短,适应小规模铜精矿冶炼粗铜,富集有价金属的要求。%This paper introduces the smelting method of blister copper from copper sulfide concentrate by using oxygen top-blown converter. It uses oxygen top blown converter to smelt, and flash smelts the copper sulphide concentrate to produce copper matte, and then air blows copper matte to produce blister. This method is suitable for small scale blister-smelting out of copper concentrate and meets with the requirement of enriching valuable metal, in which the equipment investment is small, and the process is short.

  2. The impact of blood and seminal plasma zinc and copper concentrations on spermogram and hormonal changes in infertile Nigerian men.

    Science.gov (United States)

    Akinloye, Oluyemi; Abbiyesuku, Fayeofori M; Oguntibeju, Oluwafemi O; Arowojolu, Ayodele O; Truter, Ernie J

    2011-07-01

    Zinc (Zn) and copper (Cu) concentrations in sera and seminal plasma of 60 infertile males (40 oligozoospermic and 20 azoospermic) and 40 males with evidence of fertility (normozoospermic; controls) were estimated using atomic absorption spectrophotometry. The results were correlated with the subject's spermogram and hormonal levels in order to determine their relationship and significance in male infertility. The mean serum concentration of zinc was significantly (pspermatozoa viability. In conclusion, the measurement of serum Zn level, apart from being a good index of the assessment of prostatic secretion and function, may be considered a useful tool in addition to other parameters in assessing male infertility. Also, a lower Cu/Zn ratio in seminal plasma may serve as a supportive tools in assessing male infertility.

  3. Global and regional estimates of warm cloud droplet number concentration based on 13 years of AQUA-MODIS observations

    Science.gov (United States)

    Bennartz, Ralf; Rausch, John

    2017-08-01

    We present and evaluate a climatology of cloud droplet number concentration (CDNC) based on 13 years of Aqua-MODIS observations. The climatology provides monthly mean 1 × 1° CDNC values plus associated uncertainties over the global ice-free oceans. All values are in-cloud values, i.e. the reported CDNC value will be valid for the cloudy part of the grid box. Here, we provide an overview of how the climatology was generated and assess and quantify potential systematic error sources including effects of broken clouds, and remaining artefacts caused by the retrieval process or related to observation geometry. Retrievals and evaluations were performed at the scale of initial MODIS observations (in contrast to some earlier climatologies, which were created based on already gridded data). This allowed us to implement additional screening criteria, so that observations inconsistent with key assumptions made in the CDNC retrieval could be rejected. Application of these additional screening criteria led to significant changes in the annual cycle of CDNC in terms of both its phase and magnitude. After an optimal screening was established a final CDNC climatology was generated. Resulting CDNC uncertainties are reported as monthly-mean standard deviations of CDNC over each 1 × 1° grid box. These uncertainties are of the order of 30 % in the stratocumulus regions and 60 to 80 % elsewhere.

  4. Concentrations and solubility of trace elements in fine particles at a mountain site, southern China: regional sources and cloud processing

    Science.gov (United States)

    Li, T.; Wang, Y.; Li, W. J.; Chen, J. M.; Wang, T.; Wang, W. X.

    2015-08-01

    The concentrations and solubility of twelve trace elements in PM2.5 at Mt. Lushan, southern China, were investigated during the summer of 2011 and the spring of 2012. The average PM2.5 mass was 55.2 ± 20.1 μg m-3 during the observation period. Temporal variations of all trace elements including total and water-soluble fractions with several dust storm spikes in total fractions of Al and Fe were observed. The enrichment factor (EF) values were 1 order of magnitude higher for the water-soluble fractions versus the total fractions of trace elements. Four major emission sources, namely nonferrous metal mining and smelting (for Cr, As, Ba and parts of Zn), coal combustion (for Pb, Zn, Se, Cu and Mn), crustal materials (for Al and Fe) and municipal solid waste incineration (for Cd and Mo), were classified by principal component analysis (PCA). Trajectory cluster analysis and the potential source contribution function (PSCF) consistently identified the Yangtze River delta (YRD), the Pearl River delta (PRD), and the neighbouring provinces of Mt. Lushan as the major source regions and transport pathways for anthropogenic elements. Northern China was identified as a major source region for crustal elements. It should be noted that apart from the YRD, the area around Mt. Lushan has become the most significant contributor to the solubility of most trace elements. Element solubility can be partially determined by emission sources. However, enhanced solubility of trace elements corresponding to increased concentrations of sulfate after the occurrence of cloud events indicated significant effects of cloud processing on aerosol element dissolution. Metal particles mixed with sulfate in cloud droplet residues were further investigated through transmission electron microscopy (TEM) analysis. Irreversible alteration of particle morphology by cloud processing was confirmed to be highly responsible for the enhancement of trace element solubility. The findings from this study imply an

  5. Energy-Dispersive X-Ray Spectroscopy Mapping of Porous Coatings Obtained on Titanium by Plasma Electrolytic Oxidation in a Solution Containing Concentrated Phosphoric Acid with Copper Nitrate

    Directory of Open Access Journals (Sweden)

    Rokosz K.

    2016-09-01

    Full Text Available The SEM and EDS study results of coatings obtained on titanium by Plasma Electrolytic Oxidation (PEO in the electrolytes containing of 600 g copper nitrate in 1 liter of concentrated phosphoric acid at 450 V for 1 and 3 minutes, are presented. The obtained coatings are porous and consist mainly of phosphorus within titanium and copper. It was found that the time of PEO oxidation has impact on the chemical composition of the coatings. The longer time of PEO treatment, the higher amount of copper inside coating. The PEO oxidation of titanium for 1 minute has resulted in the creation of coating, on which 3 phases where found, which contained up to 13.4 wt% (9 at% of copper inside the phosphate structure. In case of 1 minute PEO treatment of titanium, the 2 phases were found, which contained up to 13 wt% (8 at% of copper inside the phosphate structure. The copper-to-phosphorus ratios after 1 minute processing belong to the range from 0.28 by wt% (0.14 by at% to 0.47 by wt% (0.23 by at%, while after 3 minutes the same ratios belong to the range from 0.27 by wt% (0.13 by at% to 0.35 by wt% (0.17 by at%. In summary, it should be stated that the higher amounts of phosphorus and copper were recorded on titanium after PEO oxidation for 3 minutes than these after 1 minute.

  6. Concentrations of strontium, barium, cadmium, copper, zinc, manganese, chromium, antimony, selenium and lead in the equine liver and kidneys.

    Science.gov (United States)

    Paßlack, Nadine; Mainzer, Barbara; Lahrssen-Wiederholt, Monika; Schafft, Helmut; Palavinskas, Richard; Breithaupt, Angele; Neumann, Konrad; Zentek, Jürgen

    2014-01-01

    The concentrations of specific elements in the equine liver and kidneys are of practical relevance since horses are not only food-producing animals, but also partially serve as an indicator for the environmental pollution, as the basic feed includes plants like grass, grain and fruits. In this study, the concentrations of strontium (Sr), barium (Ba), cadmium (Cd), copper (Cu), zinc (Zn), manganese (Mn), chromium (Cr), antimony (Sb), selenium (Se) and lead (Pb) were measured in the liver, renal cortex and renal medulla of 21 horses (8 male; 13 female; aged between 5 months-28 years), using inductively coupled plasma mass spectrometry. Comparable Cu and Zn concentrations were detected in the liver and renal cortex, while approximately 50% lower concentrations were measured in the renal medulla. The lowest Sr, Cd and Se, but the highest Mn, Sb and Pb concentrations were measured in the liver. The Ba concentrations were comparable in the renal cortex and medulla, but lower in the liver of the horses. Gender-related differences were observed for Cd, Mn and Cr, with higher Cd concentrations in the liver, but lower Mn concentrations in the renal cortex and lower Cr concentrations in the renal medulla of female horses. Age-related differences were detected for most measured elements, however, the animal number per age-group was only low. In conclusion, the present study provides important reference data for the storage of Sr, Ba, Cd, Cu, Zn, Mn, Cr, Sb, Se and Pb in the liver and kidneys of horses, which are of practical relevance for an evaluation of the exposure of horses to these elements, either via feed or the environment.

  7. A new single-moment microphysics scheme for cloud-resolving models using observed dependence of ice concentration on temperature.

    Science.gov (United States)

    Khairoutdinov, M.

    2015-12-01

    The representation of microphysics, especially ice microphysics, remains one of the major uncertainties in cloud-resolving models (CRMs). Most of the cloud schemes use the so-called bulk microphysics approach, in which a few moments of such distributions are used as the prognostic variables. The System for Atmospheric Modeling (SAM) is the CRM that employs two such schemes. The single-moment scheme, which uses only mass for each of the water phases, and the two-moment scheme, which adds the particle concentration for each of the hydrometeor category. Of the two, the single-moment scheme is much more computationally efficient as it uses only two prognostic microphysics variables compared to ten variables used by the two-moment scheme. The efficiency comes from a rather considerable oversimplification of the microphysical processes. For instance, only a sum of the liquid and icy cloud water is predicted with the temperature used to diagnose the mixing ratios of different hydrometeors. The main motivation for using such simplified microphysics has been computational efficiency, especially in the applications of SAM as the super-parameterization in global climate models. Recently, we have extended the single-moment microphysics by adding only one additional prognostic variable, which has, nevertheless, allowed us to separate the cloud ice from liquid water. We made use of some of the recent observations of ice microphysics collected at various parts of the world to parameterize several aspects of ice microphysics that have not been explicitly represented before in our sing-moment scheme. For example, we use the observed broad dependence of ice concentration on temperature to diagnose the ice concentration in addition to prognostic mass. Also, there is no artificial separation between the pristine ice and snow, often used by bulk models. Instead we prescribed the ice size spectrum as the gamma distribution, with the distribution shape parameter controlled by the

  8. Effects of turbulence on mixed-phase deep convective clouds under different basic-state winds and aerosol concentrations

    Science.gov (United States)

    Lee, Hyunho; Baik, Jong-Jin; Han, Ji-Young

    2014-12-01

    The effects of turbulence-induced collision enhancement (TICE) on mixed-phase deep convective clouds are numerically investigated using a 2-D cloud model with bin microphysics for uniform and sheared basic-state wind profiles and different aerosol concentrations. Graupel particles account for the most of the cloud mass in all simulation cases. In the uniform basic-state wind cases, graupel particles with moderate sizes account for some of the total graupel mass in the cases with TICE, whereas graupel particles with large sizes account for almost all the total graupel mass in the cases without TICE. This is because the growth of ice crystals into small graupel particles is enhanced due to TICE. The changes in the size distributions of graupel particles due to TICE result in a decrease in the mass-averaged mean terminal velocity of graupel particles. Therefore, the downward flux of graupel mass, and thus the melting of graupel particles, is reduced due to TICE, leading to a decrease in the amount of surface precipitation. Moreover, under the low aerosol concentration, TICE increases the sublimation of ice particles, consequently playing a partial role in reducing the amount of surface precipitation. The effects of TICE are less pronounced in the sheared basic-state wind cases than in the uniform basic-state wind cases because the number of ice crystals is much smaller in the sheared basic-state wind cases than in the uniform basic-state wind cases. Thus, the size distributions of graupel particles in the cases with and without TICE show little difference.

  9. Uneven distribution of hepatic copper concentration and diagnostic value of double-sample biopsy in Wilson's disease.

    Science.gov (United States)

    Liggi, Mauro; Mais, Claudia; Demurtas, Mauro; Sorbello, Orazio; Demelia, Enrico; Civolani, Alberto; Demelia, Luigi

    2013-12-01

    BACKGROUND AND AIMS. Determination of hepatic copper (Cu) concentration is important in Wilson's disease (WD) diagnosis. The aim of this study was to evaluate uneven distribution of liver Cu concentration and the utility of double-sample biopsy in WD diagnosis. METHODS. Thirty-five WD patients (20 male; mean age 41 ± 9 years) were enrolled in the study and double-liver samples for biopsy were obtained. A further 30 WD patients, in whom Cu determination was performed using single-liver samples, were also enrolled as controls. RESULTS. A marked difference in hepatic Cu concentration was observed between the two sample groups (p liver fibrosis (p liver biopsy compared to 93% for single-sample liver biopsy. CONCLUSIONS. Liver Cu content was unevenly distributed in the WD subjects, irrespective of fibrosis levels and disease phenotypes; hence WD can be misdiagnosed using single-sample liver Cu measurement. Double-sample biopsy sensitivity is greater than that obtained with single-sample biopsy and should therefore be considered to evaluate liver Cu concentration at initial diagnosis in all patients.

  10. Dietary calcium intake, serum copper concentration and bone density in postmenopausal women

    Energy Technology Data Exchange (ETDEWEB)

    Strause, L.; Andon, M.B.; Howard, G.; Smith, K.T.; Saltman, P. (Univ. of California, San Diego, La Jolla (United States) Procter and Gamble Co., Cincinnati, OH (United States))

    1991-03-11

    Data from experimental animal nutrition and animal husbandry indicate that several trace minerals, including copper (Cu) are involved in bone metabolism. In addition, a large body of data suggests that low dietary calcium (Ca) intake is a risk factor for age related bone loss. The authors measured the serum (Cu), dietary Ca intake (dCa) and bone mineral density (BMD) in the spine of 225 postmenopausal women. The median dCa and serum (Cu) were 562 mg/d and 9.73 umoles/L, respectively. Serum (Cu) but, not dCa, was greater in subjects with a history of estrogen therapy (ERT). BMD was higher in subjects with above median dCa and serum (Cu) (group 1) compared to those with below median values (group 2). BMD was intermediate for subjects with either Low serum (Cu):High dCa or High serum (Cu):Low dCa. This relationship was observed in the subject group as a whole, as well as in subgroups partitioned according to history of ERT. Groups 1 and 2 did not differ in basic demographic characteristics such as age, age at menopause, body weight and height. These data support the hypothesis that Ca and Cu nutriture are determinants of skeletal health in postmenopausal women.

  11. Bio-processing of copper from combined smelter dust and flotation concentrate: A comparative study on the stirred tank and airlift reactors

    Energy Technology Data Exchange (ETDEWEB)

    Vakylabad, Ali Behrad, E-mail: alibehzad86@yahoo.co.uk [Department of Mining Engineering, Shahid Bahonar University, Kerman (Iran, Islamic Republic of); Engineers of Nano and Bio Advanced Sciences Company (ENBASCo.), ATIC, Mohaghegh University (Iran, Islamic Republic of); Schaffie, Mahin [Department of Chemical Engineering, Shahid Bahonar University of Kerman, Kerman (Iran, Islamic Republic of); Mineral Industries Research Centre (MIRC), Shahid Bahonar University of Kerman, Kerman (Iran, Islamic Republic of); Ranjbar, Mohammad [Department of Mining Engineering, Shahid Bahonar University, Kerman (Iran, Islamic Republic of); Mineral Industries Research Centre (MIRC), Shahid Bahonar University of Kerman, Kerman (Iran, Islamic Republic of); Manafi, Zahra [Sarcheshmeh Copper Complex, National Iranian Copper Industry Company (Iran, Islamic Republic of); Darezereshki, Esmaeel [Mineral Industries Research Centre (MIRC), Shahid Bahonar University of Kerman, Kerman (Iran, Islamic Republic of); Energy and Environmental Engineering Research Center (EERC), Shahid Bahonar University of Kerman, Kerman (Iran, Islamic Republic of)

    2012-11-30

    Highlights: Black-Right-Pointing-Pointer Flotation concentrate and smelter dust were sampled and combined. Black-Right-Pointing-Pointer Copper bioleaching from the combined was investigated. Black-Right-Pointing-Pointer Two bio-reactors were investigated and optimized: stirred and airlift. Black-Right-Pointing-Pointer STRs had better technical conditions and situations for bacterial leaching. - Abstract: To scrutinize the influence of the design and type of the bioreactors on the bioleaching efficiency, the bioleaching were evaluated in a batch airlift and a batch stirred tank bioreactors with mixed mesophilic and mixed moderately thermophilic bacteria. According to the results, maximum copper recoveries were achieved using the cultures in the stirred tank bioreactors. It is worth noting that the main phase of the flotation concentrate was chalcopyrite (as a primary sulphide), but the smelter dust mainly contained secondary copper sulphides such as Cu{sub 2}S, CuS, and Cu{sub 5}FeS{sub 4}.Under optimum conditions, copper dissolution from the combined flotation concentrate and smelter dust (as an environmental hazard) reached 94.50% in the STR, and 88.02% in the airlift reactor with moderately thermophilic, after 23 days. Also, copper extractions calculated for the bioleaching using mesophilic bacteria were 48.73% and 37.19% in the STR (stirred tank reactor) and the airlift bioreactor, respectively. In addition, the SEM/EDS, XRD, chemical, and mineralogical analyses and studies confirmed the above results.

  12. Characterization of Timed Changes in Hepatic Copper Concentrations, Methionine Metabolism, Gene Expression, and Global DNA Methylation in the Jackson Toxic Milk Mouse Model of Wilson Disease

    Directory of Open Access Journals (Sweden)

    Anh Le

    2014-05-01

    Full Text Available Background: Wilson disease (WD is characterized by hepatic copper accumulation with progressive liver damage to cirrhosis. This study aimed to characterize the toxic milk mouse from The Jackson Laboratory (Bar Harbor, ME, USA (tx-j mouse model of WD according to changes over time in hepatic copper concentrations, methionine metabolism, global DNA methylation, and gene expression from gestational day 17 (fetal to adulthood (28 weeks. Methods: Included liver histology and relevant biochemical analyses including hepatic copper quantification, S-adenosylmethionine (SAM and S-adenosylhomocysteine (SAH liver levels, qPCR for transcript levels of genes relevant to methionine metabolism and liver damage, and DNA dot blot for global DNA methylation. Results: Hepatic copper was lower in tx-j fetuses but higher in weanling (three weeks and adult tx-j mice compared to controls. S-adenosylhomocysteinase transcript levels were significantly lower at all time points, except at three weeks, correlating negatively with copper levels and with consequent changes in the SAM:SAH methylation ratio and global DNA methylation. Conclusion: Compared to controls, methionine metabolism including S-adenosylhomocysteinase gene expression is persistently different in the tx-j mice with consequent alterations in global DNA methylation in more advanced stages of liver disease. The inhibitory effect of copper accumulation on S-adenosylhomocysteinase expression is associated with progressively abnormal methionine metabolism and decreased methylation capacity and DNA global methylation.

  13. Physiological responses of sweet potato (Ipomoea batatas L. plants due to different copper concentrations

    Directory of Open Access Journals (Sweden)

    Cristina Copstein Cuchiara

    2015-12-01

    Full Text Available At low concentrations, Cu is considered as an essential micronutrient for plants and as a constituent and activator of several enzymes. However, when in excess, Cu can negatively affect plant growth and metabolism. Therefore, the aim of this study was to evaluate physiological responses of sweet potato plants at different Cu concentrations by measuring morphological parameters, antioxidant metabolism, stomatal characteristics, and mineral profile. For this purpose, sweet potato plants were grown hydroponically in complete nutrient solution for six days. Then, the plants were transferred to solutions containing different Cu concentrations, 0.041 (control, 0.082, and 0.164 mM, and maintained for nine days. The main effect of increased Cu concentration was observed in the roots. The sweet potato plants grown in 0.082 mM Cu solution showed increased activity of antioxidant enzymes and no changes in growth parameters. However, at a concentration of 0.164 mM, Cu was transported from the roots to the shoots. This concentration altered morpho-anatomical characteristics and activated the antioxidant system because of the stress generated by excess Cu. On the basis of the results, it can be concluded that the sweet potato plants were able to tolerate Cu toxicity until 0.082 mM.

  14. Analysis of the electrolyte convection inside the concentration boundary layer during structured electrodeposition of copper in high magnetic gradient fields.

    Science.gov (United States)

    König, Jörg; Tschulik, Kristina; Büttner, Lars; Uhlemann, Margitta; Czarske, Jürgen

    2013-03-19

    To experimentally reveal the correlation between electrodeposited structure and electrolyte convection induced inside the concentration boundary layer, a highly inhomogeneous magnetic field, generated by a magnetized Fe-wire, has been applied to an electrochemical system. The influence of Lorentz and magnetic field gradient force to the local transport phenomena of copper ions has been studied using a novel two-component laser Doppler velocity profile sensor. With this sensor, the electrolyte convection within 500 μm of a horizontally aligned cathode is presented. The electrode-normal two-component velocity profiles below the electrodeposited structure show that electrolyte convection is induced and directed toward the rim of the Fe-wire. The measured deposited structure directly correlates to the observed boundary layer flow. As the local concentration of Cu(2+) ions is enhanced due to the induced convection, maximum deposit thicknesses can be found at the rim of the Fe-wire. Furthermore, a complex boundary layer flow structure was determined, indicating that electrolyte convection of second order is induced. Moreover, the Lorentz force-driven convection rapidly vanishes, while the electrolyte convection induced by the magnetic field gradient force is preserved much longer. The progress for research is the first direct experimental proof of the electrolyte convection inside the concentration boundary layer that correlates to the deposited structure and reveals that the magnetic field gradient force is responsible for the observed structuring effect.

  15. Variation in O3, H2O2, NO2 and SO2 concentrations during cloud episodes at Mount Szrenica, Karkonosze Mountains, Poland

    Science.gov (United States)

    Zwozdziak, J.; Sowka, I.; Zwozdziak, A.; Kmiec, G.; Francois, S.; Monod, A.; Poulain, L.; Wortham, H.

    2003-04-01

    One of the places in Europe which is particularly suitable for studying the qualitative and quantitative interactions between the polluted air and clouds is the region of Mount Szrenica (1362 m a.s.l.) situated in the Karkonosze Mountains, Poland. Karkonosze Mountains collect a substantial amount of pollution from the Black Triangle region, e.g. from the highly industrialised areas of western Czech Republic, southwestern Poland and eastern Germany. The main objective was to quantify losses of pollutants during cloud events, in order to investigate whether the cloud removed a significant quantity of pollutants from the air mass. The field campaign was conducted in the Karkonosze Mts. during a period of July 2000. Pollutant monitors (SO_2, NOx, O_3 and H_2O_2 analysers), an automated cloud water collector (NESA 1, Kroneis GmbH, hourly samples) and an automatic weather station (Campbell Scientific Ltd. ser. no. 2192) were placed at Mount Szrenica. Analysis for the ions in cloud water samples was performed with a Waters ion chromatograph (IC). Case studies did not provide evidence of significant losses of SO_2 and NO_2 as air passed over the mountain and through clouds on the summit of Szrenica as well as in the air before and after the cloud. In the case of ozone and hydrogen peroxide, the variations were observed and some reasons are discussed in more details. The O_3 concentration inside the clouds also followed a pattern related to that of NO_2 and H_2O_2. The ionic composition of the cloud was considered to be significantly different from that of the sites in Europe discussed earlier. Relatively low sulphate and ammonium concentrations in comparison to nitrate, chloride and calcium levels were observed.

  16. Cloud water composition during HCCT-2010: Scavenging efficiencies, solute concentrations, and droplet size dependence of inorganic ions and dissolved organic carbon

    Science.gov (United States)

    van Pinxteren, Dominik; Wadinga Fomba, Khanneh; Mertes, Stephan; Müller, Konrad; Spindler, Gerald; Schneider, Johannes; Lee, Taehyoung; Collett, Jeffrey L.; Herrmann, Hartmut

    2016-03-01

    Cloud water samples were taken in September/October 2010 at Mt. Schmücke in a rural, forested area in Germany during the Lagrange-type Hill Cap Cloud Thuringia 2010 (HCCT-2010) cloud experiment. Besides bulk collectors, a three-stage and a five-stage collector were applied and samples were analysed for inorganic ions (SO42-,NO3-, NH4+, Cl-, Na+, Mg2+, Ca2+, K+), H2O2 (aq), S(IV), and dissolved organic carbon (DOC). Campaign volume-weighted mean concentrations were 191, 142, and 39 µmol L-1 for ammonium, nitrate, and sulfate respectively, between 4 and 27 µmol L-1 for minor ions, 5.4 µmol L-1 for H2O2 (aq), 1.9 µmol L-1 for S(IV), and 3.9 mgC L-1 for DOC. The concentrations compare well to more recent European cloud water data from similar sites. On a mass basis, organic material (as DOC × 1.8) contributed 20-40 % (event means) to total solute concentrations and was found to have non-negligible impact on cloud water acidity. Relative standard deviations of major ions were 60-66 % for solute concentrations and 52-80 % for cloud water loadings (CWLs). The similar variability of solute concentrations and CWLs together with the results of back-trajectory analysis and principal component analysis, suggests that concentrations in incoming air masses (i.e. air mass history), rather than cloud liquid water content (LWC), were the main factor controlling bulk solute concentrations for the cloud studied. Droplet effective radius was found to be a somewhat better predictor for cloud water total ionic content (TIC) than LWC, even though no single explanatory variable can fully describe TIC (or solute concentration) variations in a simple functional relation due to the complex processes involved. Bulk concentrations typically agreed within a factor of 2 with co-located measurements of residual particle concentrations sampled by a counterflow virtual impactor (CVI) and analysed by an aerosol mass spectrometer (AMS), with the deviations being mainly caused by systematic

  17. Multiscale modeling of nanoindentation in copper thin films via the concurrent coupling of the meshless Hermite-Cloud method with molecular dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Ng, T.Y., E-mail: MTYNG@ntu.edu.sg [School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore); Pandurangan, Venkataraman; Li Hua [School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore)

    2011-10-01

    This paper investigates the 2D nanoindentation of a copper thin film using a concurrent multiscale method. The method uses molecular dynamics (MD) simulation in the atomistic region, the strong-form meshless Hermite-Cloud method in the continuum region and a handshaking algorithm to concurrently couple them. A fully atomistic simulation is also carried out to validate the multiscale method. The results, namely the load versus indentation depth graph obtained from the multiscale method shows only slight quantitative variation from that of the full atomistic model. More importantly, the graphs from both simulations show a similar trend thus validating the 2D multiscale method. The displacement profile without discontinuities further supports the efficiency of the multiscale method in ensuring smooth exchange of information between the atomistic and continuum domains. The material properties extracted from the simulation include the force/unit length values obtained by dividing the maximum load on the indenter by its contact perimeter, instead of the hardness value obtained in 3D simulations. By restricting the atomic scale detail to the critical regions beneath the indenter, the multiscale method effectively saves computational resources to more than one order (close to 13 times less for this problem), thus making it feasible to simulate problems of larger dimensions that are not amenable to complete atomistic simulations.

  18. Cloud point extraction-atomic absorption spectrometry for pre-concentration and determination of cadmium in cigarette samples.

    Science.gov (United States)

    Tavallali, Hossein; Boustani, Fazlollah; Yazdandoust, Mozhdeh; Aalaei, Mehdi; Tabandeh, Mahboobeh

    2013-05-01

    A new complexing agent, 2-((2-((1H-benzo[d]imidazole-2yl)methoxy)phenoxy)methyl)-1H-benzo[d]imidazole (BIMPI), was used in cloud point extraction and applied for selective pre-concentration of trace amounts of cadmium in cigarette samples. Cadmium was complexed with BIMPI in a buffer solution (pH = 10) using Triton X-114 as surfactant and quantitatively extracted into a small volume of the surfactant-rich phase after centrifugation. Under optimized conditions (pH = 10.0, 0.8 × 10(-4) mol L(-1) BIMPI and 0.08 % (w/v) Triton X-114), calibration graph was linear in the range of 34.0-1,670.0 μg L(-1). The proposed method was applied to the determination of Cd in various cigarette (tobacco) samples which gave satisfactory results.

  19. Spatial variations of concentrations of copper and its speciation in the soil-rice system in Wenling of southeastern China.

    Science.gov (United States)

    Zhao, Keli; Fu, Weijun; Liu, Xingmei; Huang, Dongliang; Zhang, Chaosheng; Ye, Zhengqian; Xu, Jianming

    2014-01-01

    Copper (Cu) is one of the essential elements for plant growth, while excessive Cu in soils has potential environmental risks. There is little information on spatial variation of Cu in practical paddy fields. This is now important for appropriate agricultural management. The spatial patterns of Cu, its fractions in soils, and its concentrations in rice were investigated in a typical rice production region-Wenling of southeastern China. A total of 96 pairs of rice grain and soil samples (0-15 cm) were collected. The total concentration of Cu and its fractions were very variable, with large skewness, kurtosis, and coefficient of variation (CV) values. Compared to the guideline value (50 mg kg(-1)), Cu pollution in paddy fields was observed in the study area. All the measured Cu concentrations in rice were lower than 10 mg kg(-1), suggesting that they remained at a safe level. Spatial analyses including Moran's I index and geostatistics results indicated that high-high spatial patterns for both Cu in soils and rice were found in the northwest part, which was mainly related to industrial and E-waste dismantling activities. The low-low spatial patterns of Cu in the soil-rice system were located in the south part of study area. The cross-correlogram results indicated that Cu concentration in rice was significantly spatially correlated with total Cu in soils, its fractions, and soil organic matter (SOM), but significantly negatively correlated with pH and electrical conductivity (EC). Most of the selected variables had a clear spatial correlation range with Cu in rice. The ranges of significant spatial correlation (p < 0.05) could be obtained and further used for dividing agricultural management zones.

  20. Transition of dislocation nucleation induced by local stress concentration in nanotwinned copper.

    Science.gov (United States)

    Lu, N; Du, K; Lu, L; Ye, H Q

    2015-07-16

    Metals with a high density of nanometre-scale twins have demonstrated simultaneous high strength and good ductility, attributed to the interaction between lattice dislocations and twin boundaries. Maximum strength was observed at a critical twin lamella spacing (∼15 nm) by mechanical testing; hence, an explanation of how twin lamella spacing influences dislocation behaviours is desired. Here, we report a transition of dislocation nucleation from steps on the twin boundaries to twin boundary/grain boundary junctions at a critical twin lamella spacing (12-37 nm), observed with in situ transmission electron microscopy. The local stress concentrations vary significantly with twin lamella spacing, thus resulting in a critical twin lamella spacing (∼18 nm) for the transition of dislocation nucleation. This agrees quantitatively with the mechanical test. These results demonstrate that by quantitatively analysing local stress concentrations, a direct relationship can be resolved between the microscopic dislocation activities and macroscopic mechanical properties of nanotwinned metals.

  1. Occurrence and speciation of copper in slags obtained during the pyrometallurgical processing of chalcopyrite concentrates at the Huelva smelter (Spain

    Directory of Open Access Journals (Sweden)

    Fernández-Caliani J.C.

    2012-01-01

    Full Text Available Slags involved in smelting-converting-refining operations to produce blister copper at the Atlantic Copper smelter, in Huelva (Spain, have been investigated by quantitative electron microprobe analysis, X-ray diffraction and digital imaging techniques. The results showed that mechanically entrapped matte particles are the dominant copper losses in the slags. The largest proportion of Cubearing particles (2.0-3.5 vol % is present in the magnetite-rich converter slags, due to the negative effect of viscosity on coalescence and precipitation of copper matte during conversion. They consist of high-grade matte particles with a core of copper metal rimmed by a copper sulfide phase (Cu2S. The mechanical entrainment of copper matte by slags from both the flash and electric furnaces resulted in copper losses accounting for less than 1.5 vol %, mostly occurring as tiny particles with a stoichiometric composition close to that of bornite (Cu5FeS4. Copper was not found to be enriched in fayalite and magnetite as solid solution.

  2. Cloud water composition during HCCT-2010: Scavenging efficiencies, solute concentrations, and droplet size dependence of inorganic ions and dissolved organic carbon

    Directory of Open Access Journals (Sweden)

    D. van Pinxteren

    2015-09-01

    Full Text Available Cloud water samples were taken in September/October 2010 at Mt. Schmücke in a rural, forested area in Germany during the Lagrange-type Hill Cap Cloud Thuringia 2010 (HCCT-2010 cloud experiment. Besides bulk collectors, a 3-stage and a 5-stage collector were applied and samples were analysed for inorganic ions (SO42−, NO3−, NH4+, Cl−, Na+, Mg2+, Ca2+, K+, H2O2 (aq, S(IV, and dissolved organic carbon (DOC. Campaign volume-weighted mean concentrations were 191, 142, and 39 μmol L−1 for ammonium, nitrate, and sulfate, respectively, between 4 and 27 μmol L−1 for minor ions, 5.4 μmol L−1 for H2O2 (aq, 1.9 μmol L−1 for S(IV, and 3.9 mgC L−1 for DOC. The concentrations compare well to more recent European cloud water data from similar sites. On a mass basis, organic material (as DOC · 1.8 contributed 20–40 % (event means to total solute concentrations and was found to have non-negligible impact on cloud water acidity. Relative standard deviations of major ions were 60–66 % for solute concentrations and 52–80 % for cloud water loadings (CWLs. Contrary to some earlier suggestions, the similar variability of solute concentrations and CWLs together with the results of back trajectory analysis and principal component analysis, suggests that concentrations in incoming air masses (i.e. air mass history, rather than cloud liquid water content (LWC was the main factor controlling bulk solute concentrations at Mt. Schmücke. Droplet effective radius was found to be a somewhat better predictor for cloud water total ionic content (TIC than LWC, even though no single explanatory variable can fully describe TIC (or solute concentration variations in a simple functional relation due to the complex processes involved. Bulk concentrations typically agreed within a factor of 2 with co-located measurements of residual particle concentrations sampled by a counterflow virtual impactor (CV and analysed by an aerosol mass spectrometer (AMS, with

  3. SERUM ZINC, COPPER AND ALPHA TOCOPHEROL CONCENTRATIONS IN DOGS WITH ECZEMA

    OpenAIRE

    Alev AKDOĞAN KAYMAZ; ALTUĞ, TUNCAY; BAKIREL, Utku; GÖNÜL, Remzi; GÜZEL, Ömer; Tan, Hüseyin

    2017-01-01

    SummaryIn Istanbul, most cases of eczema have been seen in dogs which have been fed with only meat or bread. Only the dogs with eczema, that were fed with unbalanced home diets were included in this study. The eczema group contained the dogs of Karabash, German Shepherd and mixed breeds and control group contained healthy dogs (Karabash). Skin samples were examined microscopically. Serum zinc (Zn), cop­per (Cu) concentrations and alpha tocopherol (a-TCP) levels were measured in all dogs. Seru...

  4. SERUM ZINC, COPPER AND ALPHA TOCOPHEROL CONCENTRATIONS IN DOGS WITH ECZEMA

    OpenAIRE

    Alev AKDOĞAN KAYMAZ; ALTUĞ, TUNCAY; BAKIREL, Utku; GÖNÜL, Remzi; GÜZEL, Ömer; Tan, Hüseyin

    2013-01-01

    SummaryIn Istanbul, most cases of eczema have been seen in dogs which have been fed with only meat or bread. Only the dogs with eczema, that were fed with unbalanced home diets were included in this study. The eczema group contained the dogs of Karabash, German Shepherd and mixed breeds and control group contained healthy dogs (Karabash). Skin samples were examined microscopically. Serum zinc (Zn), cop­per (Cu) concentrations and alpha tocopherol (a-TCP) levels were measured in all dogs. Seru...

  5. Trace element concentration in soils and plants in the vicinity of Miduk copper mine

    Directory of Open Access Journals (Sweden)

    Farid Moore

    2014-10-01

    Full Text Available Introduction High concentrations of metals are usually encountered in surface soil and vegetation in areas affected by mining activity (Liu et al., 2006. Different distribution of elements in chemical fractions result in different bioavailability; therefore knowledge of the total content of an element in soil is not a sufficient criterion to estimate the environmental implications of trace metal presence (Maiz et al., 2000. Sequential extraction analysis gives information on the element distribution among different phases of soil. Several schemes of sequential extraction are used for the determination of commonly distinguished metal species, which are in general: (1 easily exchangeable or water soluble; (2 specifically sorbed; e.g., by carbonates or phosphates; (3 organically bound; (4 occluded by Fe-Mn oxides and hydroxides; and (5 structurally bound in minerals or residual (Kabata-Pendias and Mukherjee, 2007. The main objectives of this study are: (1 to describe the distribution pattern of elements in rocks and soils of the Miduk area; (2 to assess the fractionation of elements in soil and the mining impact on the mobility of trace elements; (3 to investigate the uptake of analyzed elements by selected indigenous plant species. Materials and Methods In this study, 32 soil samples at two depths (0-5 cm and 15-20 cm, were analyzed for total concentration of 45 elements. In order to assess the possible bioaccumulation of the elements, the roots and the overground parts of 3 plant species (Astragalus-Fabaceae, Acanthophyllum -Caryophyllaceae, Artemisia -Asteraceae were also collected and analyzed. Enrichment factors (EFs were calculated to assess whether the concentrations observed represent background or contaminated levels. The Tessier et al. method (Tessier et al., 1979 was chosen for sequential extraction of 6 subsoil samples. Correlation analysis was used to examine the relationship between the analyzed elements in soil. The plant’s ability

  6. Contribution of carbonaceous material to cloud condensation nuclei concentrations in European background (Mt. Sonnblick) and urban (Vienna) aerosols

    Science.gov (United States)

    Hitzenberger, R.; Berner, A.; Giebl, H.; Kromp, R.; Larson, S. M.; Rouc, A.; Koch, A.; Marischka, S.; Puxbaum, H.

    During four intensive measurement campaigns (two on Mt. Sonnblick, European background aerosol, and two in Vienna, urban aerosol), cloud condensation nuclei (CCN) were measured at supersaturations of 0.5%. Impactor measurements of the mass size distribution in the size range 0.1-10 μm were performed and later analyzed for Cl -, NO -3, SO 2-4, Na +, NH +4, K +, Ca 2+ and Mg 2+ by ion chromatography, for total carbon (TC) using a combustion method, and for black carbon (BC) by an optical method (integrating sphere). Organic carbon (OC) was defined as the difference between TC (minus carbonate carbon) and BC. At all sites, the mass fraction of BC in the submicron aerosol was comparable (4-5%). CCN concentrations on Mt. Sonnblick were found to be 10-30% of those measured in Vienna, although high Mt. Sonnblick concentrations were comparable to low Vienna concentrations (around 800 cm -3). The contribution of organic material was estimated from the mass concentrations of the chemical species sampled on the impactor stage with the lowest cut point (0.1-0.215 μm aerodynamic equivalent diameter). On Mt. Sonnblick, TC material contributed 11% to the total mass in fall 1995, and 67% in summer 1996, while the OC fraction was 6 and 61%. The combined electrolytes and mineral material contributed 18 and 16% in fall and summer. During the Vienna spring campaign, the contributions of OC and electrolytes to the total mass concentration in this size range were 48 and 36%, respectively.

  7. Utilization of polysaccharides as depressants for the flotation separation of copper/lead concentrate

    Institute of Scientific and Technical Information of China (English)

    Qin Wenqing; Wei Qian; Jiao Fen; Yang Congren; Liu Ruizeng; Wang Peipei; Ke Lifang

    2013-01-01

    The interaction mechanism between dextrin and minerals has been investigated through micro-flotation,adsorption density measurements,Fourier transform infrared ray (FTIR) spectroscopic studies and dissolution tests.Dextrin shows a good depressing action towards galena but not chaicopyrite.FTIR spectroscopic studies indicate that dextrin chemically adsorbed on galena surface in alkaline pH range.Dissolution tests confirm leaching action of metal ions from chalcopytite and galena surfaces,and dextrin-lead ion interaction.Adsorption measurements present that the higher adsorption density of O-isopropyl-N-ethyl thionocarbamate (IPETC) onto chalcopyrite than that onto galena,and IPETC adsorbed on galena decrease with increasing dextrin concentrations in the presence of dextrin,attesting the flotation results.

  8. Histopathological changes in snail, Pomacea canaliculata, exposed to sub-lethal copper sulfate concentrations.

    Science.gov (United States)

    Dummee, Vipawee; Tanhan, Phanwimol; Kruatrachue, Maleeya; Damrongphol, Praneet; Pokethitiyook, Prayad

    2015-12-01

    The acute toxicity test of Cu including range-finding and definitive test, was performed on golden apple snails, Pomacea canaliculata. The median lethal concentrations (LC50) of Cu at exposure times of 24, 48, 72 and 96 h were 330, 223, 177 and 146 µg/L, respectively. P. canaliculata were exposed to Cu at 146 µg/L for 96 h to study bioaccumulation and histopathological alterations in various organs. Snails accumulated elevated levels of Cu in gill, and lesser amounts in the digestive tract, muscle, and digestive gland. Histopathological investigation revealed several alterations in the epithelia of gill, digestive tract (esophagus, intestine, rectum), and digestive gland. The most striking changes were observed in the epithelium of the gill in which there was loss of cilia, an increase in number of mucus cells, and degeneration of columnar cells. Similar changes occurred in digestive tract epithelium. The digestive gland showed moderate alterations, vacuolization and degeneration of cells and an increase in the number of basophilic cells. We concluded that, P. canaliculata has a great potential as a bioindicator for Cu, and a biomarker for monitoring Cu contamination in aquatic environment.

  9. Simple method of determination of copper, mercury and lead in potable water with preliminary pre-concentration by total reflection X-ray fluorescence spectrometry

    Science.gov (United States)

    Hołyńska, B.; Ostachowicz, B.; Wȩgrzynek, D.

    1996-06-01

    Total reflection X-ray fluorescence spectrometry and chemical pre-concentration procedures have been applied for the analysis of trace concentrations of copper, mercury, and lead in drinking water samples. A simple total reflection module has been used in X-ray measurements. The elements under investigation were pre-concentrated by complexation using a mixture of carbamates followed by solvent extraction with methyl isobutyl ketone. The preconcentration procedure was tested with the use of twice-distilled water samples and samples of mineral and tap water spiked with known additions of copper, mercury, and lead. The obtained recovery and precision values are presented. The minimum detection limits for the determination of these elements in mineral and tap water samples were found to be 40 ng l -1, 60 ng l -1, and 60 ng l -1, respectively.

  10. Tissue concentrations as the dose metric to assess potential toxic effects of metals in field-collected fish: Copper and cadmium.

    Science.gov (United States)

    Meador, James P

    2015-06-01

    The present study examined the available literature linking whole-body tissue concentrations with toxic effects in fish species for copper and cadmium. The variability in effect concentration for both copper and cadmium among species occurred within an order of magnitude for all responses, whereas the range for lethal toxicity based on water exposure spanned approximately 4 to 5 orders of magnitude. Fish tissue concentrations causing adverse effects were just above background concentrations, occurring between 1 μg/g and 10 μg/g for copper and 0.1 μg/g to 4 μg/g for cadmium. The results also show that salmonids are especially sensitive to cadmium, which appears to be a function of chemical potency. No studies were found that indicated adverse effects without increases in whole-body concentration of these metals. This narrow range for dose-response implies that a toxicological spillover point occurs when the detoxification capacity of various tissues within the animal are exceeded, and this likely occurs at a similar whole-body concentration for all naïvely exposed fish species. Elevated whole-body concentrations in fish from the field may be indicative of possible acclimation to metals that may or may not result in effects for target species. Acclimation concentrations may be useful in that they signal excessive metal concentrations in water, sediment, or prey species for a given site and indicate likely toxic effects for species unable to acclimate to excess metal exposure. Using tissue residues as the dose metric for these metals provides another line of evidence for assessing impaired ecosystems and greater confidence that hazard concentrations are protective for all fish species.

  11. Bio-processing of copper from combined smelter dust and flotation concentrate: a comparative study on the stirred tank and airlift reactors.

    Science.gov (United States)

    Vakylabad, Ali Behrad; Schaffie, Mahin; Ranjbar, Mohammad; Manafi, Zahra; Darezereshki, Esmaeel

    2012-11-30

    To scrutinize the influence of the design and type of the bioreactors on the bioleaching efficiency, the bioleaching were evaluated in a batch airlift and a batch stirred tank bioreactors with mixed mesophilic and mixed moderately thermophilic bacteria. According to the results, maximum copper recoveries were achieved using the cultures in the stirred tank bioreactors. It is worth noting that the main phase of the flotation concentrate was chalcopyrite (as a primary sulphide), but the smelter dust mainly contained secondary copper sulphides such as Cu(2)S, CuS, and Cu(5)FeS(4).Under optimum conditions, copper dissolution from the combined flotation concentrate and smelter dust (as an environmental hazard) reached 94.50% in the STR, and 88.02% in the airlift reactor with moderately thermophilic, after 23 days. Also, copper extractions calculated for the bioleaching using mesophilic bacteria were 48.73% and 37.19% in the STR (stirred tank reactor) and the airlift bioreactor, respectively. In addition, the SEM/EDS, XRD, chemical, and mineralogical analyses and studies confirmed the above results. Copyright © 2012 Elsevier B.V. All rights reserved.

  12. Revovery of Copper from a Refractory Gold Concentrate%复杂含铜金精矿铜回收工艺研究*

    Institute of Scientific and Technical Information of China (English)

    刘亚建

    2013-01-01

    Focusing on a refractory gold concentrate containing copper , a process of roasting -acid leaching -extraction was applied and the optimum conditions were found .Test results show that the Cu leaching rate was 96.30%, and the copper grade of acid -leach residue was lower than 0 .2%.the concentrate was roasted 2 h at 650 ℃, and leached with 35 g/L sulfuric acid at 90 ℃for 1.5 h, with the liquid-solid ratio being 1.5 ∶1.Copper was then extracted from the lixivium at optimal condition .The extraction agent concentration was 20% and O/A ratio was 2 ∶1 , with the mixing time being 4 min and pH value being 1.5.The extraction rate of copper was above 96%.The copper element was recoveried effectively using the process .%针对某含铜金精矿,研究了焙烧-酸浸-萃取回收铜工艺。结果表明,在焙烧温度650℃,焙砂在初酸浓度为35 g/L、液固比1.5∶1,浸出温度90℃,浸出时间1.5 h的条件下,铜浸出率高达96.30%,酸浸渣铜品位可降至0.2%以下;萃取剂浓度为20%,相比O/A=2∶1,混合时间为4 min,pH值1.5,铜萃取率可达96%以上,实现了铜的高效回收。

  13. 10 CFR Appendix C to Part 835 - Derived Air Concentration (DAC) for Workers From External Exposure During Immersion in a Cloud of...

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Derived Air Concentration (DAC) for Workers From External Exposure During Immersion in a Cloud of Airborne Radioactive Material C Appendix C to Part 835 Energy DEPARTMENT OF ENERGY OCCUPATIONAL RADIATION PROTECTION Pt. 835, App. C Appendix C to Part 835—Derived...

  14. Differences in liquid cloud droplet effective radius and number concentration estimates between MODIS collections 5.1 and 6 over global oceans

    Directory of Open Access Journals (Sweden)

    J. Rausch

    2017-06-01

    Full Text Available Differences in cloud droplet effective radius and cloud droplet number concentration (CDNC estimates inferred from the Aqua–MODIS (Moderate Resolution Imaging Spectroradiometer collections 5.1 (C5.1 and 6 (C6 cloud products (MYD06 are examined for warm clouds over global oceans for the year 2008. Individual pixel level retrievals for both collections are aggregated to 1°  ×  1° and compared globally and regionally for the three main spectral channel pairs used for MODIS cloud optical property retrievals. Comparisons between both collections are performed for cases in which all three effective radii retrievals are classified by the MODIS cloud product as valid. The contribution to the observed differences of several key MYD06 Collection 6 algorithm updates are also explored, with a focus on changes to the surface reflectance model, assumed solar irradiance, above-cloud emission, cloud-top pressure (CTP, and pixel registration. Global results show a neutral to positive (> 50 cm−3 change for C6-derived CDNC relative to C5.1 for the 1.6 and 2.1 µm channel retrievals, corresponding to a neutral to −2 µm difference in droplet effective radius (re. For 3.7 µm retrievals, CDNC results show a negative change in the tropics, with differences transitioning toward positive values with increasing latitude spanning −25 to +50 cm−3 related to a +2.5 to −1 µm transition in effective radius. Cloud optical thickness (τ differences were small relative to effective radius and found to not significantly impact CDNC estimates. Regionally, the magnitude and behavior of the annual CDNC cycle are compared for each effective radius retrieval. Results from this study indicate significant inter-collection differences in aggregated values of effective radius due to changes to the precomputed retrieval lookup tables (LUTs for ocean scenes, changes to retrieved cloud-top pressure, solar irradiance, or above-cloud thermal emission

  15. Integrated spectral analysis of 18 concentrated star clusters in the Small Magellanic Cloud

    CERN Document Server

    Piatti, A E; Bica, E; Claria, J J; Parisi, M C

    2005-01-01

    We present in this study flux-calibrated integrated spectra in the range 3600-6800A for 18 concentrated SMC clusters. Cluster reddening values were estimated by interpolation between the extinction maps of Burstein & Heiles (1982, AJ, 87, 1165) and Schlegel et al. (1998, ApJ, 500, 525). The cluster parameters were derived from the template matching procedure by comparing the line strengths and continuum distribution of the cluster spectra with those of template cluster spectra with known parameters and from the equivalent width (EW) method. In this case, new calibrations were used together with diagnostic diagrams involving the sum of EWs of selected spectral lines. A very good agreement between ages derived from both methods was found. The final cluster ages obtained from the weighted average of values taken from the literature and the present measured ones range from 15 Mr (e.g. L51) to 7 Gyr (K3). Metal abundances have been derived for only 5 clusters from the present sample, while metallicity values d...

  16. Copper concentration of vineyard soils as a function of pH variation and addition of poultry litter

    Directory of Open Access Journals (Sweden)

    Gilmar Ribeiro Nachtigall

    2007-11-01

    Full Text Available Copper (Cu concentration was evaluated as a function of pH variation and addition of poultry litter to a Dystrophic Lithic Udorthent and a Humic Dystrudept from the state of Rio Grande do Sul, Brazil, cultivated with vines treated with successive applications of Cu-based product. Samples were collected from the surface layer (0 to 10 cm. Soluble Cu concentration was determined using DTPA and Mehlich III as extractants, and exchangeable Cu was determined in CaCl2. The availability of Cu was mainly affected by the soil pH. CaCl2 extractant had the best correlation with Cu concentration in contaminated soils, according to treatments applied. The addition of poultry litter did not reduce Cu availability in these soils. Total soil Cu content varied between 1,300 and 1,400 mg kg-1 in both soils. Copper available fractions, extracted by DTPA, CaCl2 and Mehlich III, averaged 35, 0.2 and 63%, respectively, of the total Cu present in the soil.Avaliaram-se os teores de Cu em função da variação do pH e da adição de cama-de-frango de dois solos com elevados teores deste elemento. Foram coletadas amostras da camada superficial (0 a 10 cm de um typical dystrophic Lithic Udorthent - LU (Neossolo Litólico distrófico típico e de um Humic Dystrudept - HD (Cambissolo Húmico alumínico típico da região da Serra do RS, cultivados com parreirais que receberam aplicações sucessivas de produtos à base de Cu. Foram determinados os teores de Cu solúvel em DTPA e pelo método Mehlich III, além do Cu trocável em CaCl2. A disponibilidade de Cu foi afetada principalmente pelo pH do solo. O extrator CaCl2 foi o que melhor se correlacionou com os teores de Cu em solos contaminados em função dos tratamentos aplicados. A adição de cama-de-frango não diminuiu a disponibilidade de Cu destes solos. Os teores de Cu total variaram entre 1.300 e 1.400 mg kg-1 nos dois solos. Considerando os teores totais de Cu nos solos, as frações "disponíveis", extra

  17. Concentration of copper, iron, zinc, cadmium, lead, and nickel in bull and ram semen and relation to the occurrence of pathological spermatozoa.

    Science.gov (United States)

    Massányi, P; Trandzik, J; Nad, P; Koreneková, B; Skalická, M; Toman, R; Lukac, N; Halo, M; Strapak, P

    2004-01-01

    In this study the concentration of copper, iron, zinc, cadmium, lead, and nickel in bull and ram semen and relation of these metals to spermatozoa morphology was investigated. Analysis by atomic absorption spectrophotometry showed that copper concentration was significantly higher (pzinc concentration was higher in bull semen in comparison with ram semen. The iron and cadmium concentrations in the semen were similar. Higher concentration of lead was found in ram semen. Higher levels of nickel were found in ram semen in comparison with bulls. In bull semen 11.79+/-4.88% of pathological spermatozoa was found. Higher occurrence of pathological spermatozoa was in ram semen (17.17+/-3.76) in comparison with the semen of bulls. Separated tail, tail torso, and knob twisted tail were the most frequent forms of pathological spermatozoa in both species. Correlation analysis in bulls showed high positive relation between iron and zinc (r = 0.72), nickel and separated tail (r = 0.76), separated tail and tail torso (r = 0.71), tail torso and total number of pathological spermatozoa (r=0.72), and between tail ball and total number of pathological spermatozoa (r = 0.78). In rams high positive correlation between cadmium and lead (r=0.98), nickel and separated tail (r=0.77), separated tail and total number of pathological spermatozoa (r=0.69), knob twisted tail and retention of cytoplasmic drop (r=0.78), and between knob twisted tail and other pathological spermatozoa (r = 0.71) was found. High negative correlation in ram semen was observed between copper and nickel (r=0.71), copper and separated tail (r=0.70), and between iron and tail torso (r=0.67). The results suggest that the studied metals have a direct effect on spermatozoa quality.

  18. 内蒙古大型铜钼矿铜钼分离试验研究%Investigation on Separation of Copper-molybdenum Bulk Concentrate

    Institute of Scientific and Technical Information of China (English)

    刘子龙; 杨洪英; 佟琳琳

    2013-01-01

    In flotation the copper-molybdenum bulk concentrate is difficultly separated. The reason is that the contents of molybdenite and copper distribution in the-O. 043mm of bulk concentrate are 77. 30% and 65. 77% , respectively. In the experiment, the bulk concentrate is firstly thickened and dereagented, then add sodium silicate and NaHS as depressor of the gangue and copper minerals; add oxidant potassium permanganate to depress the ultra-fine size secondary copper minerals. With the condition of fine size(82. 5% passing 0. 043 mesh) and the closed water circuit, the closed process of experiment is one roughing, two scavenging, four cleaning, two cleaning after scrubbing. The effective copper and molybdenum separation is achieved. The grade of molybdenum concentrate is 55. 73%Mo,0. 64%Cu with recovery of 68, 11% ,while the grade of copper concentrate is 2L 36% Cu,0. 1447% Mo with recovery of 99. 98% .%内蒙古某低品位铜钼混合精矿中辉钼矿和铜矿的嵌布粒度很细,在-0.043mm级别中,辉钼矿、铜矿物的含量分别为77.30%和65.77%,造成铜钼浮选分离困难.试验首先对铜钼混合精矿进行浓密脱药,然后以水玻璃和硫氢化钠作为脉石矿物和铜矿物的抑制剂,并用氧化剂高锰酸钾进一步抑制微细颗粒次生铜矿物,在利用多次循环闭路回水、再磨细度82.5%-0.043mm的条件下,经过一次粗选、二次扫选和四次精选,擦洗后再进行二次精选的闭路试验,获得了钼品位55.73%、含铜0.64%,钼回收率68.11%的钼精矿;铜品位21.36%、含钼0.1447%,铜回收率99.98%的铜精矿,实现了铜钼的有效分离.

  19. Concentrations of arsenic, copper, cobalt, lead and zinc in cassava (Manihot esculenta Crantz) growing on uncontaminated and contaminated soils of the Zambian Copperbelt

    Science.gov (United States)

    Kříbek, B.; Majer, V.; Knésl, I.; Nyambe, I.; Mihaljevič, M.; Ettler, V.; Sracek, O.

    2014-11-01

    The concentrations of arsenic (As), copper (Cu), cobalt (Co), lead (Pb) and zinc (Zn) in washed leaves and washed and peeled tubers of cassava (Manihot esculenta Crantz, Euphorbiaceae) growing on uncontaminated and contaminated soils of the Zambian Copperbelt mining district have been analyzed. An enrichment index (EI) was used to distinguish between contaminated and uncontaminated areas. This index is based on the average ratio of the actual and median concentration of the given contaminants (As, Co, Cu, mercury (Hg), Pb and Zn) in topsoil. The concentrations of copper in cassava leaves growing on contaminated soils reach as much as 612 mg kg-1 Cu (total dry weight [dw]). Concentrations of copper in leaves of cassava growing on uncontaminated soils are much lower (up to 252 mg kg-1 Cu dw). The concentrations of Co (up to 78 mg kg-1 dw), As (up to 8 mg kg-1 dw) and Zn (up to 231 mg kg-1 dw) in leaves of cassava growing on contaminated soils are higher compared with uncontaminated areas, while the concentrations of lead do not differ significantly. The concentrations of analyzed chemical elements in the tubers of cassava are much lower than in its leaves with the exception of As. Even in strongly contaminated areas, the concentrations of copper in the leaves and tubers of cassava do not exceed the daily maximum tolerance limit of 0.5 mg kg-1/human body weight (HBW) established by the Joint FAO/WHO Expert Committee on Food Additives (JECFA). The highest tolerable weekly ingestion of 0.025 mg kg-1/HBW for lead and the highest tolerable weekly ingestion of 0.015 mg kg-1/HBW for arsenic are exceeded predominantly in the vicinity of smelters. Therefore, the preliminary assessment of dietary exposure to metals through the consumption of uncooked cassava leaves and tubers has been identified as a moderate hazard to human health. Nevertheless, as the surfaces of leaves are strongly contaminated by metalliferous dust in the polluted areas, there is still a potential hazard

  20. Cloud Resolving Simulations of Mixed-Phase Arctic Stratus Observed during BASE: Sensitivity to Concentration of Ice Crystals and Large-Scale Heat and Moisture Advection.

    Science.gov (United States)

    Jiang, Hongli; Cotton, William R.; Pinto, James O.; Curry, Judy A.; Weissbluth, Michael J.

    2000-07-01

    The authors' previous idealized, two-dimensional cloud resolving model (CRM) simulations of Arctic stratus revealed a surprising sensitivity to the concentrations of ice crystals. In this paper, simulations of an actual case study observed during the Beaufort and Arctic Seas Experiment are performed and the results are compared to the observed data.It is again found in the CRM simulations that the simulated stratus cloud is very sensitive to the concentration of ice crystals. Using midlatitude estimates of the availability of ice forming nuclei (IFN) in the model, the authors find that the concentrations of ice crystals are large enough to result in the almost complete dissipation of otherwise solid, optically thick stratus layers. A tenuous stratus can be maintained in the simulation when the continuous input of moisture through the imposed large-scale advection is strong enough to balance the ice production. However, in association with the large-scale moisture and warm advection, only by reducing the concentration of IFN to 0.3 of the midlatitude estimate values can a persistent, optically thick stratus layer be maintained. The results obtained from the reduced IFN simulation compare reasonably well with observations.The longwave radiative fluxes at the surface are significantly different between the solid stratus and liquid-water-depleted higher ice crystal concentration experiments.This work suggests that transition-season Arctic stratus can be very vulnerable to anthropogenic sources of IFN, which can alter cloud structure sufficiently to affect the rates of melting and freezing of the Arctic Ocean.The authors find that the Hallett-Mossop riming splintering mechanism is not activated in the simulations because the cloud droplets are very small and cloud temperatures are outside the range supporting efficient rime splintering. Thus, the conclusions drawn from the results presented in this paper may be applicable to only a limited class of Arctic stratus.

  1. Evaluation of copper concentration in subclinical cases of white muscle disease and its relationship with cardiac troponin I.

    Directory of Open Access Journals (Sweden)

    Forough Ataollahi

    Full Text Available The present study aims to evaluate the serum level of copper (Cu in lambs suffering from subclinical forms of white muscle disease (WMD and its relationship with cardiac troponin I (cTn-I as a novel biomarker of cardiovascular disorders. Ten milliliters of jugular blood were taken from 200 lambs less than one year old to measure serum concentrations of Cu, selenium (Se, and cTn-I. The subjects were divided into 2 groups, namely, the deficient group which included 36 lambs, and the control group which included 164 lambs according to the reference serum Se concentration (50 ng/mL. Serum Se levels in the deficient group were lower than 50 ng/mL. By contrast, the control group showed Se levels higher than 50 ng/mL. Differences among the serum Cu and cTn-I levels were determined in both groups. The mean ±SD and median of serum Cu and cTn-I levels in the deficient group were lower and higher than those in the control group, respectively. A significant positive correlation was observed between serum Cu and Se levels, and also serum Cu and Se levels showed a negative correlation with serum cTn-I concentrations. Stepwise linear regression analysis showed that serum Cu levels were correlated positively with serum Se levels (p<0.05. Receiver operating characteristic (ROC curve analysis indicated that the area under curve (AUC of Cu was significantly higher than that of cTn-I based on the reference diagonal line. It is important to keep in mind that the value of AUC for the ROC curve is between 0.5 and 1.00, in which the lowest accuracy is related to the reference diagonal line with AUC of 0.5. A cut-off was determined to indicate which Cu level can discriminate between affected and healthy lambs. The cut-off level, sensitivity, and specificity of Cu in this study were 144.5 ng/mL, 74%, and 61%, respectively.

  2. Singular Value Decomposition Analysis of Cloud Fraction Cover and Sea Ice Concentration over the Arctic Region, 1982-2009

    Science.gov (United States)

    Boccolari, Mauro; Parmiggiani, Flavio

    2016-08-01

    In this study, the coupled spatial and temporal variability between seasonal data of Cloud Fraction Cover (CFC) and Sea Ice Concentration (SIC) in the Arctic Ocean for the 1982-2009 period were investigated by using the Singular Value Decomposition (SVD) method.The spatial patterns of CFCs related to the first mode of co-variability, identify the maximum covariance, for all seasons, in the Barents Sea and in the Arctic Ocean Canada, while the SIC and 'found in the Chukchi Sea in autumn (in according to the maximum sea ice melting) and the Barents sea during both the winter and spring.CFC spatial patterns related to the first mode of co- variability, locate maximum covariance, for all seasons, in the Barents Sea and in the Canadian side of the Arctic Ocean, while for SIC is found in the Chukchi Sea during autumn (corresponding to the maximum sea ice melting) and in the Barents Sea during both the winter and spring.Finally, the correlation between the seasonal time series of expansion coefficients derived from the SVD analysis, for both CFC and SIC fields, with the seasonal time series of some relevant climate indices for the Arctic (NAO, AO, PDO and PNA). Statistically significant values for both fields were found during summer with the AO, and during autumn with the PNA.

  3. Handling of Copper and Copper Oxide Nanoparticles by Astrocytes.

    Science.gov (United States)

    Bulcke, Felix; Dringen, Ralf

    2016-02-01

    Copper is an essential trace element for many important cellular functions. However, excess of copper can impair cellular functions by copper-induced oxidative stress. In brain, astrocytes are considered to play a prominent role in the copper homeostasis. In this short review we summarise the current knowledge on the molecular mechanisms which are involved in the handling of copper by astrocytes. Cultured astrocytes efficiently take up copper ions predominantly by the copper transporter Ctr1 and the divalent metal transporter DMT1. In addition, copper oxide nanoparticles are rapidly accumulated by astrocytes via endocytosis. Cultured astrocytes tolerate moderate increases in intracellular copper contents very well. However, if a given threshold of cellular copper content is exceeded after exposure to copper, accelerated production of reactive oxygen species and compromised cell viability are observed. Upon exposure to sub-toxic concentrations of copper ions or copper oxide nanoparticles, astrocytes increase their copper storage capacity by upregulating the cellular contents of glutathione and metallothioneins. In addition, cultured astrocytes have the capacity to export copper ions which is likely to involve the copper ATPase 7A. The ability of astrocytes to efficiently accumulate, store and export copper ions suggests that astrocytes have a key role in the distribution of copper in brain. Impairment of this astrocytic function may be involved in diseases which are connected with disturbances in brain copper metabolism.

  4. Trace elements in the human endometrium. I. Zinc, copper, manganese, sodium and potassium concentrations at various phases of the normal menstrual cycle.

    Science.gov (United States)

    Hagenfeldt, K; Plantin, L O; Diczfalusy, E

    1970-11-01

    The cyclic variations in the content of 5 trace elements in the normal human endometrium were studied by means of neutron activation analysis. The concentrations of zinc, copper, manganese, sodium, and potassium were measured in endometrial biopsy specimens taken from 6 healthy, normally menstruating volunteers from 10 to 32 years of age. 4 specimens were obtained from each during 4 consecutive cycles in the following phases: a) early proliferative (Days 6-10); late proliferative (Days 11-14); c) early secretory (Days 15-18); and d) late secretory Days 22-27). Biopsies were taken with a Novak type suction curette without anesthesia and without dilation of the cervix. Chemical methodology is described. An analysis of variance of the data revealed that in the early proliferative phase the human endometrium is characterized by significantly elevated concentrations of manganese (p greater than .001), sodium (p greater than .01), and potassium (p greater than .001). However, the late secretory endometrium is characterized by a highly significant rise in its zinc concentration (p greater than .001), accompanied by a highly significantly decreased concentration of sodium (p greater than .001) and potassium (p greater than .001). The copper concentration of the secretory endometria was significantly higher than that of the proliferative endometria (p greater than .001). The significance of the findings was the same whether values were expressed per g protein or per g wet tissue. It is suggested that the high concentrations of zinc and copper associated with low levels of manganese, sodium, and potassium at the expected time of implantation may be a reflection of changes in endometrial enzyme activities. Investigations are in progress to explore this possibility.

  5. 铜钼精矿制取钼酸铵试验研究%Experimental Study on Preparation of Ammonium Molybdate from Copper Molybdenum Concentrate

    Institute of Scientific and Technical Information of China (English)

    李冠军; 鲁兴武

    2014-01-01

    Copper molybdenum ammonia solution was obtain by roasting under oxidation and two stage ammonia leaching of copper molybdenum concentrate .The influences of purifying agent consumption,reaction time,reaction temperature to the purification process were studied in the paper.Purified ammonium molybdate solution obtained by acid precipitation meet the requirements of national standard for thhe second grade product.%铜钼精矿氧化焙烧-二段氨浸得到铜钼氨溶液,通过考察净化剂用量、时间、温度对净化过程的影响,净化得到的钼酸铵溶液酸沉得到的四钼酸铵符合国标二级品的标准要求。

  6. Concentration Tests for a High Silicon Copper-sulfur Mine%某高硅铜硫矿石分选试验

    Institute of Scientific and Technical Information of China (English)

    宁发添; 冯忠伟

    2011-01-01

    广西某高硫铜矿石中滑石等易浮硅质矿物含量高,现场采用弱磁选-浮铜-浮硫工艺流程进行分选,除弱磁选能较好地刚收磁黄铁矿外,黄铜矿浮选和黄铁矿浮选均因易浮硅质矿物的干扰而难以获得合格精矿.为此,在大量探索试验的基础上,采用弱磁选-黄铜矿和硅质矿物混合浮选-混浮精矿铜硅摇床分离-混浮尾矿浮黄铁矿的工艺流程处理该矿石,获得了磁选硫精矿硫品位和回收率分别为38.69%和64.48%,浮选硫精矿硫品位和网收率分别为44.57%和30.99%,铜精矿铜品位和回收率分别为13.87%和63.89%的良好试验指标,有效地综合回收了铜、硫矿物.%A certain high-sulfur copper ore in Guangxi contains high content of easy floating siliceous mineral,such as talc. The process of low intensity magnetic separation-copper floating-sulfur floating is carried out on the field. There,except for pyrrhotite well recovered by weak magnetic separation,it is difficult to obtain the qualified concentrate from flotation of chalcopyrite and pyrite due to the interference of silica minerals. Based on a large number of tests ,the process of low intensity magnetic separation-mixing flotation of chalcopyrite and siliceous minerals-shaking table separation for mixing flotation of silicon and copper concentrate - mixing flotation of pyrite from tailings is adopted to treat this ore. By this way,sulfur concentrate with S grade and recovery of 38.69% and 64. 48% by magnetic separation,and 44. 57% and 30. 99% by flotation,and copper concentrate with Cu grade and recovery of 13.87% and 63. 89% are realized respectively. So the copper and sulfur minerals can be effectively recovered.

  7. Investigation of the seasonal variations of aerosol physicochemical properties and their impact on cloud condensation nuclei number concentration

    Science.gov (United States)

    Logan, Timothy S.

    Aerosols are among the most complex yet widely studied components of the atmosphere not only due to the seasonal variability of their physical and chemical properties but also their effects on climate change. The three main aerosol types that are known to affect the physics and chemistry of the atmosphere are: mineral dust, anthropogenic pollution, and biomass burning aerosols. In order to understand how these aerosols affect the atmosphere, this dissertation addresses the following three scientific questions through a combination of surface and satellite observations: SQ1: What are the seasonal and regional variations of aerosol physico-chemical properties at four selected Asian sites? SQ2: How do these aerosol properties change during transpacific and intra-continental long range transport? SQ3: What are the impacts of aerosol properties on marine boundary layer cloud condensation nuclei number concentration? This dissertation uses an innovative approach to classify aerosol properties by region and season to address SQ1. This is useful because this method provides an additional dimension when investigating the physico-chemical properties of aerosols by linking a regional and seasonal dependence to both the aerosol direct and indirect effects. This method involves isolating the aerosol physico-chemical properties into four separate regions using AERONET retrieved Angstrom exponent (AEAOD) and single scattering co-albedo (o oabs) to denote aerosol size and absorptive properties. The aerosols events are then clustered by season. The method is first applied to four AERONET sites representing single mode aerosol dominant regions: weakly absorbing pollution (NASA Goddard), strongly absorbing pollution (Mexico City), mineral dust (Solar Village), and biomass burning smoke (Alta Floresta). The method is then applied to four Asian sites that represent complicated aerosol components. There are strong regional and seasonal influences of the four aerosol types over the

  8. Determination of fluorine in copper concentrate via high-resolution graphite furnace molecular absorption spectrometry and direct solid sample analysis - Comparison of three target molecules.

    Science.gov (United States)

    Cadorim, Heloisa R; de Gois, Jefferson S; Borges, Aline R; Vale, Maria Goreti R; Welz, Bernhard; Gleisner, Heike; Ott, Christina

    2018-01-01

    The chemical composition of complex inorganic materials, such as copper concentrate, may influence the economics of their further processing because most smelters, and particularly the producers of high-purity electrolyte copper, have strict limitations for the permissible concentration of impurities. These components might be harmful to the quality of the products, impair the production process and be hazardous to the environment. The goal of the present work is the development of a method for the determination of fluorine in copper concentrate using high-resolution graphite furnace molecular absorption spectrometry and direct solid sample analysis. The molecular absorption of the diatomic molecule CaF was measured at 606.440nm. The molecule CaF was generated by the addition of 200µg Ca as the molecule-forming reagent; the optimized pyrolysis and vaporization temperatures were 900°C and 2400°C, respectively. The characteristic mass and limit of detection were 0.5ng and 3ng, respectively. Calibration curves were established using aqueous standard solutions containing the major components Cu, Fe, S and the minor component Ag in optimized concentrations. The accuracy of the method was verified using certified reference materials. Fourteen copper concentrate samples from Chile and Australia were analyzed to confirm the applicability of the method to real samples; the concentration of fluorine ranged from 34 to 5676mgkg(-1). The samples were also analyzed independently at Analytik Jena by different operators, using the same equipment, but different target molecules, InF and GaF, and different operating conditions; but with a few exceptions, the results agreed quite well. The results obtained at Analytik Jena using the GaF molecule and our results obtained with CaF, with one exception, were also in agreement with the values informed by the supplier of the samples, which were obtained using ion selective electrode potentiometry after alkaline fusion. A comparison will

  9. Airship measurements of aerosol size distributions, cloud droplet spectra, and trace gas concentrations in the marine boundary layers

    Energy Technology Data Exchange (ETDEWEB)

    Frick, G.M.; Hoppel, W.A. (Naval Research Lab., Washington, DC (United States))

    1993-11-01

    The use of an airship as a platform to conduct atmospheric chemistry, aerosol, and cloud microphysical research is described, and results from demonstration flights made off the Oregon coast are presented. The slow speed of the airship makes it an ideal platform to do high-spatial resolution profiling both vertically and horizontally, and to measure large aerosol and cloud droplet distributions without the difficulties caused by high-speed aircraft sampling. A unique set of data obtained during the demonstration flights show the effect that processing marine boundary layer aerosol through stratus clouds has on the aerosol size distribution. Evidence of new particle formation (nucleation of particles) was also observed on about half the days on which flights were made. 11 refs., 9 figs., 1 tab.

  10. Velocity measurements and concentration field visualizations in copper electrolysis under the influence of Lorentz forces and buoyancy

    Science.gov (United States)

    Weier, T.; Cierpka, C.; Huller, J.; Gerbeth, G.

    2006-12-01

    Velocity measurements and shadowgraph visualizations for copper electrolysis under the influence of a magnetic field are reported. Experiments in a rectangular cell show the expected strong correlation between flow features and limiting current density. The flow can be understood as driven by the interplay of Lorentz force and buoyancy. For a cylindrical cell with only slightly non-parallel electric and magnetic field lines, the presence and importance of the Lorentz force is demonstrated by velocity measurements. Figs 6, Refs 13.

  11. Lead concentration in blood of school children from copper mining area and the level of somatic development at birth

    Directory of Open Access Journals (Sweden)

    Teresa Sławińska-Ochla

    2011-12-01

    Full Text Available Background. The aim of the study was to assess the relations between lead intoxication in children at younger school age and the level of somatic development at birth. Materials and Methods. The research includes 717 children and adolescents 7–15 years old from LegnickoGłogowski copper mining region, which live in the vincity of „Głogów”, „Legnica” copper industrial plants and flotation tank reservoir „Żelazny most”. The analysis contained measures such as birth height, birth weight, Apgar score points, and blood lead level in 2007 and 2008. The whole blood lead level (Pb-B was indicated using atomic absorption spectrometry (AAS with electrothermic atomization by certified The Foundation for Children From The Copper Basin laboratory. Results.Rural childrenwere noted forsignificantly higher blood lead levelsthan urban peers. Also boysin comparison to girls had higher blood lead levels. Regardless of gender and place of residence there were no significant correlation between blood lead level and body mass at birth. Conclusion. The biological state of the organism at the moment of birth has no connection with the susceptibility to absorption of lead in the later phases of ontogenesis: the earlier school age and adlescence.

  12. Leaching of copper concentrates with high arsenic content in chlorine-chloride media; Lixiviacion de concentrados de cobre con alto contenido de arsenico en medio cloro-cloruro

    Energy Technology Data Exchange (ETDEWEB)

    Herreros, O.; Fuentes, G.; Quiroz, R.; Vinals, J.

    2003-07-01

    This work reports the results of copper concentrates leaching which have high arsenic concepts (up to 2.5%). The treatments were carried out using chlorine that forms from sodium hypochlorite and sulphuric acid. The aim of this work is to obtain a solution having high copper content 4 to 6 g/l and 5 to 7 g/l free acid in order to submit it directly to a solvent extraction stage. In addition, this solution should have minimum content of arsenic and chloride ions. To carry out this investigation, an acrylic reactor was constructed where the leaching tests were made at constant temperature in a thermostatic bath under atmospheric pressure. The concentrate samples were obtained from mineral processing plants from Antofagasta, Chile. Typical variables were studied, such as leaching agent concentration, leaching time, pulp density and temperature among others. Some of the residues were analyzed by XRD and EPS. On the other hand, the solutions were analyzed by Atomic Absorption Spectroscopy. The results indicate solutions having the contents stated above can be obtained. (Author) 19 refs.

  13. Effect of different dietary concentrations of inorganic and organic copper on growth performance and lipid metabolism of White Pekin male ducks.

    Science.gov (United States)

    Attia, Y A; Qota, E M; Zeweil, H S; Bovera, F; Abd Al-Hamid, A E; Sahledom, M D

    2012-01-01

    1. The effect of different dietary concentrations of inorganic and organic copper on performance and lipid metabolism of White Pekin ducks (WPD) was investigated from 1-49 d of age. A common basal diet was supplemented with 4, 8, 12 and 150 mg/kg of copper (Cu) from inorganic and organic sources to obtain 9 treatments, including 4 concentrations of Cu x two sources, and the unsupplemented control group. Each treatment contained 5 replicates of 9 male ducks each. 2. Supplementation of Cu at 8 mg/kg in inorganic form was adequate for growth of male WPD from 1-56 d of age. Inorganic Cu significantly decreased feed intake and improved feed conversion ratio, compared with the organic form. 3. Plasma Cu significantly increased, while plasma Zn significantly decreased, due to Cu supplementation. Organic Cu showed better efficacy than inorganic for improving liver Cu concentration, Cu excretion and apparent Cu retention. 4. Dietary Cu concentration significantly affected percentage blood and Hgb and abdominal fat deposition. In addition, inorganic Cu increased percentage blood and abdominal fat deposition compared with the organic source. 5. Supplementation of 150 mg/kg of Cu significantly decreased liver and meat lipids, cholesterol, and colour and tenderness of meat; while liver protein and moisture was increased. In addition, dietary 150 mg/kg of Cu supplementation significantly decreased plasma lipids, triglycerides and cholesterol, while increasing plasma AST and ALT. 6. Organic Cu was more potent for decreasing plasma triglycerides than the inorganic source. However, plasma cholesterol was only significantly decreased with the inorganic source of Cu, compared with the unsupplemented control. 7. The organic Cu was safer as a feed additive for WPD, especially at the lower concentrations up to 12 mg; while some mild to moderate changes may be developed at the higher doses, when fed at pharmacological concentrations as a growth promoter.

  14. 高铜铅精矿富氧底吹工业实践%Industrial Practice of Rich Oxygen Bottom Blowing Process of Smelting High Copper Content of Lead Concentrate

    Institute of Scientific and Technical Information of China (English)

    陈学兴; 欧阳坤

    2014-01-01

    A lead factory had smelted a batch of high copper content of lead concentrate , through two months of industrial practice , high copper content of lead concentrate had certain influence to the produc-tion of bottom blowing furnace and fuming furnace . The industrial test results showed that copper can be enriched in the crude lead and matte , the copper content of crude lead can reach more than 10 percent , the copper content of matte can reach more than 40 percent , the copper content of slag can be controlled under 0 .65 percent , and the recovery rate of copper can reach more than 90 percent .%某铅厂处理了一批高铜铅精矿,通过2个月的工业生产,入炉原料含铜高对底吹炉、烟化炉生产有一定影响,整个工业试验结果表明,铜可以在粗铅及锍中富集,粗铅含铜可达10%以上,锍含铜可达40%以上,弃渣含铜可控制在0.65%以下,铜的回收率可达90%。

  15. Determination of copper after cloud point extraction by flame atomic absorption spectrometry%浊点萃取-火焰原子吸收光谱法测定痕量铜

    Institute of Scientific and Technical Information of China (English)

    王尚芝; 孟双明; 关翠林; 刘月成

    2013-01-01

    A method for the determination of trace copper by flame atomic absorption spectrometry after cloud point extraction was proposed. The analyte was complexd with 2-sulfo -4-methoxy-benzenediazoaminoazobenzene (MOSDAA) and Trition X-114 was added as a nonionic surfactant. The complex formed was extracted into the phase of surfactant, then copper in the complex was determined by flame atomic absorption spectrometry. The effects of experimental conditions such as pH, chelating agent and surfactant, equilibration temperature on cloud point extraction were studied. Under the optimum conditions, the detection limit was 1.1 ng/mL (3σ)for copper, and relative standard deviation was 1.91 % (n =6). The proposed method has been applied to the determination of trace copper in millet and water with satisfactory results.%2-磺酸基-4-甲氧基苯基重氮氨基偶氮苯(MOSDAA)和Cu (Ⅱ)反应生成疏水性络合物后,被萃取到Triton X-114非离子表面活性剂胶束相中,火焰原子吸收光谱法测定其中的铜,建立了浊点萃取预富集-火焰原子吸收光谱法测定铜的方法.反应体系的pH、MOSDAA和Triton X-114的浓度、平衡温度及时间等实验条件被优化.在选择的实验条件下,方法的检出限为1.1 ng/mL(3σ),对浓度为0.1 μg/mL的Cu (Ⅱ)溶液平行测定6次,相对标准偏差为1.9%.方法已用于小米和水样中痕量铜的测定.

  16. Influence of pH and Chloride Concentration on the Corrosion Behavior of Unalloyed Copper in NaCl Solution: A Comparative Study Between the Micro and Macro Scales

    Directory of Open Access Journals (Sweden)

    Annemie Adriaens

    2012-11-01

    Full Text Available The effects of pH and chloride concentration on the electrochemical corrosion of copper in aqueous sodium chloride (NaCl media were studied at the micro scale using a microcapillary droplet cell and at the macro scale using a conventional large scale cell. Using an experimental design strategy, electrochemical response surface models of copper versus pH and NaCl concentration were constructed with the minimum number of experiments required. Results show that the electrochemical behavior of copper under corrosive media shows significant differences between the micro and macro scale experiments. At the micro scale, the pit initiation of copper occurs at more negative potentials for high NaCl concentrations and alkaline pH values. Also, the micro scale potentiostatic measurements indicate higher stabilised passive currents at high NaCl concentrations and low (acidic pH values. At the macro scale, the pH is shown to have a greater influence on the corrosion potential. The chloride concentration is the most significant factor in the passive current case while at the micro scale the effect of these two factors on the passive current was found to be the same. The surface morphology of the formed patina on the corroded copper in both micro and macro systems reveal a more significant role of the chloride concentration on the structure and the grain size of the patinas. Finally, micro and macro electrochemical impedance spectroscopy of copper at various NaCl concentrations and pH values demonstrates a different behavior of copper after several potentiodynamic polarization cycles.

  17. Metal concentrations in the soils and native plants surrounding the old flotation tailings pond of the copper mining and smelting complex Bor (Serbia).

    Science.gov (United States)

    Antonijević, M M; Dimitrijević, M D; Milić, S M; Nujkić, M M

    2012-03-01

    In this study concentrations of metals in the native plants and soils surrounding the old flotation tailings pond of the copper mine were determined. It has been established that the soil is heavily contaminated with copper, iron and arsenic, the mean concentrations being 1585.6, 29,462.5 and 171.7 mg kg(-1) respectively. All the plants, except manganese, accumulated metallic elements in concentrations which were either in the range of critical and phytotoxic values (Pb and As) or higher (Zn), and even much higher (Cu and Fe) than these values. Otherwise, the accumulation of Mn, Pb and As was considerably lower than that of Cu, Fe and Zn. In most plants the accumulation of target metals was highest in the root. Several plant species showed high bioaccumulation and translocation factor values, which classify them into species for potential use in phytoextraction. The BCF and TF values determined in Prunus persica were 1.20 and 3.95 for Cu, 1.5 and 6.0 for Zn and 1.96 and 5.44 for Pb. In Saponaria officinalis these values were 2.53 and 1.27 for Zn, and in Juglans regia L. they were 8.76 and 17.75 for Zn. The translocation factor in most plants, for most metals, was higher than one, whereas the highest value was determined in Populus nigra for Zn, amounting to 17.8. Among several tolerant species, the most suitable ones for phytostabilization proved to be Robinia pseudoacacia L. for Zn and Verbascum phlomoides L., Saponaria officinalis and Centaurea jacea L. for Mn, Pb and As. This journal is © The Royal Society of Chemistry 2012

  18. Detection of nanomolar concentrations of copper(II) with a Tb-quinoline-2-one probe using luminescence quenching or luminescence decay time.

    Science.gov (United States)

    Turel, Matejka; Duerkop, Axel; Yegorova, Alla; Scripinets, Yulia; Lobnik, Aleksandra; Samec, Niko

    2009-06-30

    We present a time-resolved (gated) luminescence-based method for determination of Cu2+ ions in microtiterplate format in the nanomolar concentration range using the novel long-lived terbium-[1-methyl-4-hydroxy-3-(N-2-ethyl-5-aminothiadiazolyl-)-carbamoyl-quinoline-2-one] (TbL) complex. The probe works best in Tb:L = 1:2 stoichiometry at neutral pH. The dynamic range is from 10 to 300 nmol L(-1) of Cu2+ and the limit of detection is 4.3 nmol L(-1). This is the lowest limit of detection achieved so far for luminescent lanthanide-based probes for copper. It is shown that gating can efficiently suppress intense, short decaying background fluorescence e.g. that of Rhodamine 6G. The assay can be performed by measurement of luminescence decay time, as well. Stern-Volmer studies indicate that static quenching dominates over dynamic quenching. TbL2 was tested for the effect of some relevant interferents and the assay was applied to the determination of copper in tap water samples. The results achieved were in good agreement with those of a reference method.

  19. Structure and properties of the slags of continuous converting of copper nickel-containing mattes and concentrates: II. Effect of the SiO2/CaO ratio on the structure and liquidus temperature of the slags

    Science.gov (United States)

    Pigarev, S. P.; Tsymbulov, L. B.; Selivanov, E. N.; Chumarev, V. M.

    2012-03-01

    The structure and liquidus temperature of the SiO2-CaO-Al2O3-FeO x -Cu2O-NiO slags that form during continuous converting of copper mattes and concentrates into blister copper are analyzed. The slag melt compositions are varied over a wide SiO2/CaO range. The slags are studied by X-ray diffraction, scanning electron microscopy, and electron-probe microanalysis. The liquidus temperature of the slags is determined by differential thermal analysis. It is found that, depending on the SiO2/CaO ratio, the structure and liquidus temperature of the slags change and the forms of copper in a slag also change. The SiO2/CaO range in a slag is recommended for the process of continuous converting of a copper nickel-containing sulfide raw materials.

  20. Sensitive determination of mercury in tap water by cloud point extraction pre-concentration and flow injection-cold vapor-inductively coupled plasma optical emission spectrometry

    Science.gov (United States)

    de Wuilloud, Jorgelina C. A.; Wuilloud, Rodolfo G.; Silva, María. F.; Olsina, Roberto A.; Martinez, Luis D.

    2002-02-01

    A pre-concentration and determination methodology for mercury at trace levels in water samples was developed. Cloud point extraction was successfully employed for the pre-concentration of mercury prior to inductively coupled plasma optical emission spectrometry coupled to a flow injection with cold vapor generation system. The mercury was extracted as mercury-2-(5-bromo-2-pyridylazo)-5-diethylaminophenol [Hg(II)-(5-Br-PADAP)] complex, at pH 9.2 mediated by micelles of the non-ionic surfactant polyethyleneglycolmono- p-nonylphenylether (PONPE 5). Cold vapor generation was developed from 100 μl of the extracted surfactant-rich phase by means of a stannous chloride (SnCl 2) solution as reluctant. An exhaustive study of the variables affecting the cloud point extraction with PONPE 5 and cold vapor mercury generation from the surfactant phase was performed. The 50-ml sample solution pre-concentration allowed us to raise an enrichment factor of 200-fold. The lower limit of detection obtained under the optimal conditions was 4 ng l -1. The precision for 10 replicate determinations at the 0.5-μg l -1 Hg level was 3.4% relative standard deviation (R.S.D.), calculated with the peak heights. The calibration graph using the pre-concentration system for mercury was linear with a correlation coefficient of 0.9998 at levels near the detection limits up to at least 50 μg l -1. The method was successfully applied to the determination of mercury in tap water samples.

  1. Coral skeletal tin and copper concentrations at Pohnpei, Micronesia: possible index for marine pollution by toxic anti-biofouling paints

    Energy Technology Data Exchange (ETDEWEB)

    Inoue, Mayuri; Suzuki, Atsushi; Nohara, Masato; Kan, Hironobu; Edward, Ahser; Kawahata, Hodaka

    2004-06-01

    We present 40 year-long skeletal chronologies of tin (Sn) and copper (Cu) from an annually-banded coral (Porites sp.) collected from Pohnpei Island, Micronesia (western equatorial Pacific). Both the elements are present in antifouling marine paints and are released inadvertently into ambient seawater. Especially, Sn has often been used in the form of tributyltin (TBT). Based on a stepwise pretreatment examination, Sn and Cu both inside and outside the aragonite lattice of the coral skeleton show a potential for providing marine pollution indicators. High values of extra-skeletal Cu/Ca and Sn/Ca atomic ratios were found between late 1960s and late 1980s during a period of active use of TBT-based antifouling paints worldwide. However, a significant decrease in both the ratios in the beginning of 1990s can be attributed to regulation of the use of TBT on cargo ships by countries such as the USA, Japan and Australia. - A new index of coral marine pollution is proposed.

  2. Development and functioning of microorganisms in concentration cycles of sulfide copper-nickel and non-sulfide apatite-nepheline ores

    Directory of Open Access Journals (Sweden)

    Fokina N. V.

    2017-03-01

    Full Text Available The number and trophic diversity of bacteria in flotation samples of apatite-nepheline and sulfide copper-nickel ores at the concentration plants of JSC "Apatite" and Kola Mining and Metallurgical Company have been determined. The study of the size and diversity of the microbiota has been conducted by culture on selective nutrient media. The total number and biomass of bacteria have been considered by fluorescence microscopy using Cyclopore polycarbonate membrane filters. Bacteria have been identified by molecular genetic methods. The least amount of both saprotrophic and other trophic groups of bacteria has been observed in the samples of ore and recycled water as at the concentrating factory of Apatit JSC, and also at the plant "Pechenganikel". It has been found out that the bacteria contained in the ore and recycling water flowing from the tailings increased their number during the flotation process due to coming of the nutrients with the flotation reagents, aeration and increased temperature. Strains which occurrence is more than 60 % have been extracted from recycled water and basic flotation products and classified as Pseudomonas. Two strains with occurrence of more than 60 % have been discovered at Apatit JSC and classified as Stenotrophomonas and Acinetobacter. The number of fungi in the cycle of apatite-nepheline ore enrichment at the factories is very low (1 to 24 CFU / 1 ml or 1 g of ore. Fungi of the genus Penicillium have been dominated, fungi of the genera Acremonium, Aureobasidium, Alternaria, Chaetomium have also been detected. At the plant "Pechenganikel" species Aspergillus fumigatus, Penicillium aurantiogriseum and P. glabrum have been extracted. It has been shown that the bacteria deteriorate the apatite flotation as a result of their interaction with active centers of calcium-containing minerals and intensive flocculation decreasing the floatation selectivity. Also some trend of copper and nickel recovery change has been

  3. Effect of the polyacrylamide concentration on the quality of the copper deposit obtained by electrolytic refining; Efecto de la concentracion de poliacrilamida sobre la calidad del deposito de cobre obtenido por refino electrolitico

    Energy Technology Data Exchange (ETDEWEB)

    Aragon, J.; Ipinza, J.; Camus, J.; Vargas, A.; Saavedra, R.

    2013-07-01

    The effect of the additive non ionic polyacrylamide (PAM), was studied at the laboratory level, as refining crystalline grain in the copper electrorefining. Experiments were performed 24 h of electrolysis, using an electrolyte of copper sulphate acid, with 0.5 to 10 mg{sup -}1 polyacrylamide at 55 degree centigrade and a current density of 260 Am{sup -}2. The effectiveness of these organic additives in copper electrorefining was determined by directly measuring the surface roughness of the copper deposit and contrasted with the results of other instrumental techniques (SEM and metallographic analysis). The results of the analysis SEM, metallographic analysis and measurement of the surface roughness of the copper deposit, show that to concentrations as low as 0.5 mg{sup -}1 of this additive is manifested its property of tuner of grain. However, in the range of 7 to 10 mg{sup -}1 of polyacrylamide, it reaches an optimum size of grain for the deposit of copper in the cathodes. (Author)

  4. Determination of isotopic composition of dissolved copper in seawater by multi-collector inductively coupled plasma mass spectrometry after pre-concentration using an ethylenediaminetriacetic acid chelating resin.

    Science.gov (United States)

    Takano, Shotaro; Tanimizu, Masaharu; Hirata, Takafumi; Sohrin, Yoshiki

    2013-06-19

    Copper is an essential trace metal that shows a vertical recycled-scavenged profile in the ocean. To help elucidate the biogeochemical cycling of Cu in the present and past oceans, it is important to determine the distribution of Cu isotopes in seawater. However, precise isotopic analysis of Cu has been impaired by the low concentrations of Cu as well as co-existing elements that interfere with measurements by multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS). The objective of this study is to develop a simple Cu pre-concentration method using Nobias-chelate PA1 resin (Hitachi High Technologies). This extraction followed by anion exchange, allows precise analysis of the Cu isotopic composition in seawater. Using this method, Cu was quantitatively concentrated from seawater and >99.9999% of the alkali and alkaline earth metals were removed. The technique has a low procedural blank of 0.70 ng for Cu for a 2L sample and the precision of the Cu isotopic analysis was ±0.07‰ (±2SD, n=6). We applied this method to seawater reference materials (i.e., CASS-5 and NASS-6) and seawater samples obtained from the northwestern Pacific Ocean. The range of dissolved δ(65)Cu was 0.40-0.68‰.

  5. The relationship between cloud condensation nuclei (CCN concentration and light extinction of dried particles: indications of underlying aerosol processes and implications for satellite-based CCN estimates

    Directory of Open Access Journals (Sweden)

    Y. Shinozuka

    2015-01-01

    Full Text Available We examine the relationship between the number concentration of boundary-layer cloud condensation nuclei (CCN and light extinction to investigate underlying aerosol processes and satellite-based CCN estimates. Regression applied to a variety of airborne and ground-based measurements identifies the CCN (cm−3 at 0.4 ± 0.1% supersaturation with 100.3α +1.3 σ0.75 where σ (M m−1 is the 500 nm extinction coefficient by dried particles and α is the Angstrom exponent. The deviation of one kilometer horizontal average data from this approximation is typically within a factor of 2.0. ∂ log CCN/∂ log σ is less than unity because, among other explanations, aerosol growth processes generally make particles scatter more light without increasing their number. This, barring extensive data aggregation and special meteorology-aerosol connections, associates doubling of aerosol optical depth with less than doubling of CCN, contrary to common assumptions in satellite-based analysis of aerosol-cloud interactions.

  6. Study on Sulphating Roasting Process for Copper-Cobalt Bulk Concentrates%某钴铜精矿硫酸化焙烧试验研究

    Institute of Scientific and Technical Information of China (English)

    刘忠胜; 邢飞; 段英楠

    2014-01-01

    With a kind of copper⁃cobalt ore from Jilin Province as raw material, a copper⁃cobalt bulk concentrate was obtained after flotation process. Then, a combined process consisting of sulphating roasting and two⁃stage leaching was adopted to recover copper and cobalt, with emphasis on probing effects of adding method and dosage of roasting additive, as well as particle size of sample on the leaching rate of copper and cobalt. In the test, with 6% sodium sulfate in liquid form as roasting additive, a roasting process at a temperature of 610 ℃ for 80 min followed by 1st⁃stage leaching with water at room temperature for 60 min and 2nd⁃stage leaching with 10%sulfuric acid at a temperature of 80℃ for 60 min, with liquid/solid ratio of 1+4, resulted in leaching rates of cobalt copper and nickel at 86.42%, 98.26% and 60.01%, respectively.%以吉林省某铜钴矿为原料,经浮选得到混合精矿试料,采用硫酸化焙烧⁃两段浸出工艺回收铜钴。重点探讨了焙烧助剂添加方式、用量、试料粒度对铜钴镍浸出率的影响。焙烧助剂采用6%硫酸钠,以液体形式加入,焙烧温度为610℃,焙烧时间80 min,一段室温水浸出,浸出时间60 min,二段10%硫酸浸出,浸出温度80℃,浸出时间60 min,浸出固液比为1+4时,钴浸出率86.42%,铜浸出率98.26%,镍浸出率60.01%。

  7. Mapping Copper and Lead Concentrations at Abandoned Mine Areas Using Element Analysis Data from ICP-AES and Portable XRF Instruments: A Comparative Study.

    Science.gov (United States)

    Lee, Hyeongyu; Choi, Yosoon; Suh, Jangwon; Lee, Seung-Ho

    2016-03-30

    Understanding spatial variation of potentially toxic trace elements (PTEs) in soil is necessary to identify the proper measures for preventing soil contamination at both operating and abandoned mining areas. Many studies have been conducted worldwide to explore the spatial variation of PTEs and to create soil contamination maps using geostatistical methods. However, they generally depend only on inductively coupled plasma atomic emission spectrometry (ICP-AES) analysis data, therefore such studies are limited by insufficient input data owing to the disadvantages of ICP-AES analysis such as its costly operation and lengthy period required for analysis. To overcome this limitation, this study used both ICP-AES and portable X-ray fluorescence (PXRF) analysis data, with relatively low accuracy, for mapping copper and lead concentrations at a section of the Busan abandoned mine in Korea and compared the prediction performances of four different approaches: the application of ordinary kriging to ICP-AES analysis data, PXRF analysis data, both ICP-AES and transformed PXRF analysis data by considering the correlation between the ICP-AES and PXRF analysis data, and co-kriging to both the ICP-AES (primary variable) and PXRF analysis data (secondary variable). Their results were compared using an independent validation data set. The results obtained in this case study showed that the application of ordinary kriging to both ICP-AES and transformed PXRF analysis data is the most accurate approach when considers the spatial distribution of copper and lead contaminants in the soil and the estimation errors at 11 sampling points for validation. Therefore, when generating soil contamination maps for an abandoned mine, it is beneficial to use the proposed approach that incorporates the advantageous aspects of both ICP-AES and PXRF analysis data.

  8. Evaluation of copper, zinc, and chromium concentration in landfill soil and hospital waste ash of Shahrekord municipal solid waste landfill

    Directory of Open Access Journals (Sweden)

    M Hatami Manesh

    2015-08-01

    Conclusion: High concentrations of metals determined in the present study represents the high application of these metals in the structure of municipal and hospital solid wastes and also their inaccurate separation. Thus, awareness about physical and chemical characteristics of municipal and hospital wastes and also the landfill soil is necessary for evaluating their effects on the soil quality and surrounding environments.

  9. Seasonal changes in copper and cobalt concentrations of Pinus nigra L., Cedrus libani and Cupressus arizonica leaves to monitor the effects of pollution in Elazig (Turkey).

    Science.gov (United States)

    Karaaslan, Nagihan M; Yaman, Mehmet

    2013-05-01

    The aim of this study is to examine seasonal changes in Cu and Co concentrations of three plant species for monitoring the effects of pollution in Elazig, Turkey. For this purpose, the leaves of the Pinus nigra L., Cedrus libani and Cupressus arizonica together with soil samples were collected from different points depending on traffic intensity, nearness the city center and cement factory as well as control location during different months of the year. Flame atomic absorption spectrophotometer (FAAS) was used for measurement of the metals in clear digests after the dry ashing method. Copper and Co concentrations were in the ranges from 1.3 to 2.6 mg x kg(-1) and < LOD to 0.26 mg x kg(-1) for Pinus nigra L., 1.2 to 4.7 mg x kg(-1) and < LOD to 0.41 mg x kg(-1) for Cedrus libani and 1.5 to 4.8 mg x kg(-1) and < LOD to 0.42 mg x kg(-1) for Cupressus arizonica, respectively. The levels observed for Cu and Co in the soil ranged from 12 to 38 mg x kg(-1) and 6.0 to 17 mg x kg(-1), respectively.

  10. Optimisation Platform for copper ore processing at the Division of Concentrator of KGHM Polska Miedz S.A.

    Directory of Open Access Journals (Sweden)

    Kuzba Bogdan

    2016-01-01

    Full Text Available The idea of Optimisation Platform is to create an innovative system. It is dedicated to technology and cost efficiency improvement of process realized at the Division of Concentrators of KGHM Polska Miedz SA. This highly sophisticated tool is based on visual, acoustic and vibrating detection systems. The range of its functionality was described in this work. Three main utility modules were described: froth flotation image processing (FloVis, grinding and classification monitoring (MillVis and belt conveyors control unit (ConVis. The effects of implementation of the system under KGHM conditions were described. It is concluded that the Optimisation Platform is one of the most promising solution for improvement of technology and economy performance at the Division of Concentrators of KGHM Polska Miedz S.A.

  11. Corrosion Behaviours of Copper Alloy in Solutions Containing Na2SO4 and NaCl with Different Concentrations

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Potentiodynamic polarisation, potential-time measurements, X-ray diffraction (XRD) and infrared spectroscopy (IR)have been used to investigate the effect of different concentrations of Na2SO4 in the absence and presence of NaCl,on the corrosion of Cu-alloy. The electrochemical measurements showed that the increase of Na2SO4 concentration led to increase the corrosion current density of Cu alloy and vice versa. The presence of NaCl shifted the potential to more cathodic potential, which had a great influence on the protectiveness of the Cu oxide layer formed on the surface in presence of Na2SO4. The spectrometric measurements indicated the constituents of the film formed on the alloy surface were mainly Cu2O, in addition to the oxides, NiO and Fe2O3, which were traced by XRD analysis.

  12. Cloud processing of soluble gases

    Science.gov (United States)

    Laj, P.; Fuzzi, S.; Facchini, M. C.; Lind, J. A.; Orsi, G.; Preiss, M.; Maser, R.; Jaeschke, W.; Seyffer, E.; Helas, G.; Acker, K.; Wieprecht, W.; Möller, D.; Arends, B. G.; Mols, J. J.; Colvile, R. N.; Gallagher, M. W.; Beswick, K. M.; Hargreaves, K. J.; Storeton-West, R. L.; Sutton, M. A.

    Experimental data from the Great Dun Fell Cloud Experiment 1993 were used to investigate interactions between soluble gases and cloud droplets. Concentrations of H 2O 2, SO 2, CH 3COOOH, HCOOH, and HCHO were monitored at different sites within and downwind of a hill cap cloud and their temporal and spatial evolution during several cloud events was investigated. Significant differences were found between in-cloud and out-of-cloud concentrations, most of which could not be explained by simple dissolution into cloud droplets. Concentration patterns were analysed in relation to the chemistry of cloud droplets and the gas/liquid equilibrium. Soluble gases do not undergo similar behaviour: CH 3COOH simply dissolves in the aqueous phase and is outgassed upon cloud dissipation; instead, SO 2 is consumed by its reaction with H 2O 2. The behaviour of HCOOH is more complex because there is evidence for in-cloud chemical production. The formation of HCOOH interferes with the odd hydrogen cycle by enhancing the liquid-phase production of H 2O 2. The H 2O 2 concentration in cloud therefore results from the balance of consumption by oxidation of SO 2 in-cloud production, and the rate by which it is supplied to the system by entrainment of new air into the clouds.

  13. CADMIUM, COPPER, LEAD AND ZINC CONCENTRATIONS IN LOW QUALITY WINES AND ALCOHOL CONTAINING DRINKS FROM ITALY, BULGARIA AND POLAND

    Directory of Open Access Journals (Sweden)

    Renata Muchacka

    2012-02-01

    Full Text Available We studied Cu, Cd, Pb and Zn concentrations in low quality wines produced in Bulgaria and Italy and in alcohol containing multi-fruit drinks produced in Poland. All the metals were present in tested products. Cadmium was not detected in Italian and Polish products. In one of the Bulgarian wines cadmium was detected in concentration of 0.004 mg•l-1. Italian wines were not contaminated with Pb. Its concentration was the highest in Polish drinks (0.88±0.52 mg•l-1. The largest and statistically significant differences occurred between Cu and Zn contents. Both metals had the highest concetrations in Italian wines (Cu - 0.13±0.05 mg•l-1; Zn - 0.83±0.56 mg•l-1, and the lowest in Polish products (Cu - 0.04±0.001 mg•l-1; Zn -0.18±0.16 mg•l-1.

  14. Cloud Processed CCN Affect Cloud Microphysics

    Science.gov (United States)

    Hudson, J. G.; Noble, S. R., Jr.; Tabor, S. S.

    2015-12-01

    Variations in the bimodality/monomodality of CCN spectra (Hudson et al. 2015) exert opposite effects on cloud microphysics in two aircraft field projects. The figure shows two examples, droplet concentration, Nc, and drizzle liquid water content, Ld, against classification of CCN spectral modality. Low ratings go to balanced separated bimodal spectra, high ratings go to single mode spectra, strictly monomodal 8. Intermediate ratings go merged modes, e.g., one mode a shoulder of another. Bimodality is caused by mass or hygroscopicity increases that go only to CCN that made activated cloud droplets. In the Ice in Clouds Experiment-Tropical (ICE-T) small cumuli with lower Nc, greater droplet mean diameters, MD, effective radii, re, spectral widths, σ, cloud liquid water contents, Lc, and Ld were closer to more bimodal (lower modal ratings) below cloud CCN spectra whereas clouds with higher Nc, smaller MD, re, σ, and Ld were closer to more monomodal CCN (higher modal ratings). In polluted stratus clouds of the MArine Stratus/Stratocumulus Experiment (MASE) clouds that had greater Nc, and smaller MD, re, σ, Lc, and Ld were closer to more bimodal CCN spectra whereas clouds with lower Nc, and greater MD, re, σ, Lc, and Ld were closer to more monomodal CCN. These relationships are opposite because the dominant ICE-T cloud processing was coalescence whereas chemical transformations (e.g., SO2 to SO4) were dominant in MASE. Coalescence reduces Nc and thus also CCN concentrations (NCCN) when droplets evaporate. In subsequent clouds the reduced competition increases MD and σ, which further enhance coalescence and drizzle. Chemical transformations do not change Nc but added sulfate enhances droplet and CCN solubility. Thus, lower critical supersaturation (S) CCN can produce more cloud droplets in subsequent cloud cycles, especially for the low W and effective S of stratus. The increased competition reduces MD, re, and σ, which inhibit coalescence and thus reduce drizzle

  15. Abnormal Copper Homeostasis: Mechanisms and Roles in Neurodegeneration

    OpenAIRE

    Mario Manto

    2014-01-01

    As a cofactor of proteins and enzymes involved in critical molecular pathways in mammals and low eukaryotes, copper is a transition metal essential for life. The intra-cellular and extra-cellular metabolism of copper is under tight control, in order to maintain free copper concentrations at very low levels. Copper is a critical element for major neuronal functions, and the central nervous system is a major target of disorders of copper metabolism. Both the accumulation of copper and copper d...

  16. Canadian House Dust Study: Population-based concentrations, loads and loading rates of arsenic, cadmium, chromium, copper, nickel, lead, and zinc inside urban homes

    Energy Technology Data Exchange (ETDEWEB)

    Rasmussen, Pat E. [Exposure and Biomonitoring Division, Healthy Environments and Consumer Safety Branch, Health Canada, 50 Colombine Driveway, Ottawa, ON, Canada K1A 0K9 (Canada); Department of Earth Sciences, University of Ottawa, 140 Louis Pasteur, Ottawa, ON, Canada K1N 6N5 (Canada); Levesque, Christine [Exposure and Biomonitoring Division, Healthy Environments and Consumer Safety Branch, Health Canada, 50 Colombine Driveway, Ottawa, ON, Canada K1A 0K9 (Canada); Chénier, Marc; Gardner, H. David [Exposure and Biomonitoring Division, Healthy Environments and Consumer Safety Branch, Health Canada, 50 Colombine Driveway, Ottawa, ON, Canada K1A 0K9 (Canada); Department of Earth Sciences, University of Ottawa, 140 Louis Pasteur, Ottawa, ON, Canada K1N 6N5 (Canada); Jones-Otazo, Heather [Regions and Programs Branch, Health Canada, 180 Queen Street West, Toronto, ON, Canada M5V 3L7 (Canada); Petrovic, Sanya [Contaminated Sites Division, Healthy Environments and Consumer Safety Branch, Health Canada, 269 Laurier Ave West, Ottawa, ON, Canada K1A 0K9 (Canada)

    2013-01-15

    The Canadian House Dust Study was designed to obtain nationally representative urban house dust metal concentrations (μg g{sup −1}) and metal loadings (μg m{sup −2}) for arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni), lead (Pb), and zinc (Zn). Consistent sampling of active dust of known age and provenance (area sampled) also permitted the calculation of indoor loading rates (mg m{sup −2} day{sup −1} for dust and μg m{sup −2} day{sup −1} for metals) for the winter season (from 2007 to 2010) when houses are most tightly sealed. Geomean/median indoor dust loading rates in homes located more than 2 km away from industry of any kind (9.6/9.1 mg m{sup −2} day{sup −1}; n = 580) were significantly lower (p < .001) than geomean (median) dust loading rates in homes located within 2 km of industry (13.5/13.4 mg m{sup −2} day{sup −1}; n = 421). Proximity to industry was characterized by higher indoor metal loading rates (p < .003), but no difference in dust metal concentrations (.29 ≥ p ≤ .97). Comparisons of non-smokers' and smokers' homes in non-industrial zones showed higher metal loading rates (.005 ≥ p ≤ .038) in smokers' homes, but no difference in dust metal concentrations (.15 ≥ p ≤ .97). Relationships between house age and dust metal concentrations were significant for Pb, Cd and Zn (p < .001) but not for the other four metals (.14 ≥ p ≤ .87). All seven metals, however, displayed a significant increase in metal loading rates with house age (p < .001) due to the influence of higher dust loading rates in older homes (p < .001). Relationships between three measures of metals in house dust – concentration, load, and loading rate – in the context of house age, smoking behavior and urban setting consistently show that concentration data is a useful indicator of the presence of metal sources in the home, whereas dust mass is the overriding influence on metal loadings and loading rates

  17. A multielement trace mineral injection improves liver copper and selenium concentrations and manganese superoxide dismutase activity in beef steers.

    Science.gov (United States)

    Genther, O N; Hansen, S L

    2014-02-01

    Trace minerals (TM) are vital to health and growth of livestock, but low dietary concentrations and dietary antagonists may reduce mineral status and feeder cattle TM status is usually unknown at arrival. The objective of this study was to examine the effect of TM status on response to mineral injection in beef cattle. Forty steers were equally assigned to diets for an 84-d depletion period: control (CON; supplemental Cu, Mn, Se, and Zn) or deficient (DEF; no supplemental Cu, Mn, Se, or Zn plus Fe and Mo as TM antagonists). Lesser liver Cu and Se concentrations (79.0 ± 11.60 and 1.66 ± 0.080 mg/kg DM, respectively) in DEF steers compared with CON steers (228.8 ± 11.60 and 2.41 ± 0.080 mg/kg DM, respectively) on d 71 of depletion indicated mild deficiencies of these TM (P animals, total MPO was greater in animals that received TM injection, but injection did not affect MPO within DEF steers (P = 0.007). Overall, TM from an injectable mineral were used differently between TM adequate and mildly deficient steers.

  18. Search Cloud

    Science.gov (United States)

    ... of this page: https://medlineplus.gov/cloud.html Search Cloud To use the sharing features on this ... of Top 110 zoster vaccine Share the MedlinePlus search cloud with your users by embedding our search ...

  19. Copper hypersensitivity.

    Science.gov (United States)

    Fage, Simon W; Faurschou, Annesofie; Thyssen, Jacob P

    2014-10-01

    The world production of copper is steadily increasing. Although humans are widely exposed to copper-containing items on the skin and mucosa, allergic reactions to copper are only infrequently reported. To review the chemistry, biology and accessible data to clarify the implications of copper hypersensitivity, a database search of PubMed was performed with the following terms: copper, dermatitis, allergic contact dermatitis, contact hypersensitivity, contact sensitization, contact allergy, patch test, dental, IUD, epidemiology, clinical, and experimental. Human exposure to copper is relatively common. As a metal, it possesses many of the same qualities as nickel, which is a known strong sensitizer. Cumulative data on subjects with presumed related symptoms and/or suspected exposure showed that a weighted average of 3.8% had a positive patch test reaction to copper. We conclude that copper is a very weak sensitizer as compared with other metal compounds. However, in a few and selected cases, copper can result in clinically relevant allergic reactions.

  20. Determination of isotopic composition of dissolved copper in seawater by multi-collector inductively coupled plasma mass spectrometry after pre-concentration using an ethylenediaminetriacetic acid chelating resin

    Energy Technology Data Exchange (ETDEWEB)

    Takano, Shotaro, E-mail: shotaro@inter3.kuicr.kyoto-u.ac.jp [Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011 (Japan); Tanimizu, Masaharu [Kochi Institute for Core Sample Research, Japan Agency for Marine-Earth Science and Technology, 200 Monobe Otsu, Nankoku 783-8502 (Japan); Hirata, Takafumi [Laboratory for Planetary Sciences, Division of Earth and Planetary Sciences, Kyoto University, Kitashirakawa Oiwake-cho, Kyoto 606-8502 (Japan); Sohrin, Yoshiki [Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011 (Japan)

    2013-06-19

    Graphical abstract: -- Highlights: •A simple analytical method for determining the Cu isotopic composition in seawater using an ethylenediaminetriacetic acid chelating resin was developed. •The accuracy was evaluated via addition of NIST SRM976 or {sup 65}Cu-enriched standard to seawater. •δ{sup 65}Cu of seawater reference materials (i.e., CASS-5 and NASS-6) and seawater samples from the northwestern Pacific Ocean were firstly determined. -- Abstract: Copper is an essential trace metal that shows a vertical recycled-scavenged profile in the ocean. To help elucidate the biogeochemical cycling of Cu in the present and past oceans, it is important to determine the distribution of Cu isotopes in seawater. However, precise isotopic analysis of Cu has been impaired by the low concentrations of Cu as well as co-existing elements that interfere with measurements by multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS). The objective of this study is to develop a simple Cu pre-concentration method using Nobias-chelate PA1 resin (Hitachi High Technologies). This extraction followed by anion exchange, allows precise analysis of the Cu isotopic composition in seawater. Using this method, Cu was quantitatively concentrated from seawater and >99.9999% of the alkali and alkaline earth metals were removed. The technique has a low procedural blank of 0.70 ng for Cu for a 2 L sample and the precision of the Cu isotopic analysis was ±0.07‰ (±2SD, n = 6). We applied this method to seawater reference materials (i.e., CASS-5 and NASS-6) and seawater samples obtained from the northwestern Pacific Ocean. The range of dissolved δ{sup 65}Cu was 0.40–0.68‰.

  1. Highly concentrated synthesis of copper-zinc-tin-sulfide nanocrystals with easily decomposable capping molecules for printed photovoltaic applications.

    Science.gov (United States)

    Kim, Youngwoo; Woo, Kyoohee; Kim, Inhyuk; Cho, Yong Soo; Jeong, Sunho; Moon, Jooho

    2013-11-07

    Among various candidate materials, Cu2ZnSnS4 (CZTS) is a promising earth-abundant semiconductor for low-cost thin film solar cells. We report a facile, less toxic, highly concentrated synthetic method utilizing the heretofore unrecognized, easily decomposable capping ligand of triphenylphosphate, where phase-pure, single-crystalline, and well-dispersed colloidal CZTS nanocrystals were obtained. The favorable influence of the easily decomposable capping ligand on the microstructural evolution of device-quality CZTS absorber layers was clarified based on a comparative study with commonly used oleylamine-capped CZTS nanoparticles. The resulting CZTS nanoparticles enabled us to produce a dense and crack-free absorbing layer through annealing under a N2 + H2S (4%) atmosphere, demonstrating a solar cell with an efficiency of 3.6% under AM 1.5 illumination.

  2. Low concentration of copper inhibits colonization of soil by the arbuscular mycorrhizal fungus Glomus intraradices and changes the microbial community structure

    DEFF Research Database (Denmark)

    Hagerberg, David; Manique, Nina; Brandt, Kristian Koefoed

    2011-01-01

    Common agricultural practices result in accumulation of copper in agricultural soils worldwide. The effect of bioavailable copper ([Cu]bio) on colonization of soil by the AM fungus Glomus intraradices and other soil microorganisms was investigated in microcosms containing copper-amended soil...... colonization of the root-free compartment was evaluated by whole-cell fatty acid analysis (WCFA) and amplified rDNA restriction analysis (ARDRA). The WCFA analysis showed that the AM fungus soil colonization was severely inhibited by Cu with a 50% reduction of mycorrhizal growth at 0.26 μg g−1 [Cu......]bio. The growth of other main microbial groups was not significantly affected by copper. However, ARDRA analysis showed a very strong effect of copper on the bacterial community composition probably caused by an increased proportion of Cu-resistant bacteria. Our results suggest that problems with plant yield may...

  3. Secondary Copper Consumption and Location in China

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    <正> China is short of copper resources and is alsothe second largest copper consuming country inthe world.The way to overcome the contradic-tion between the resource shortage and fastgrowth in consumption is to import copper rawmaterial in large quantities.Since the 1990’s,China’s import quantity of copper scrap hasincreased considerably.During the last twoyears,China has imported copper scrap worthof US$2.25 billion,1.32 times of the value ofimported copper concentrates in the same pe-riod.China is one of the biggest copper scrap

  4. Antioxidant Activity and Thermal Stability of Oleuropein and Related Phenolic Compounds of Olive Leaf Extract after Separation and Concentration by Salting-Out-Assisted Cloud Point Extraction.

    Science.gov (United States)

    Stamatopoulos, Konstantinos; Katsoyannos, Evangelos; Chatzilazarou, Arhontoula

    2014-04-08

    A fast, clean, energy-saving, non-toxic method for the stabilization of the antioxidant activity and the improvement of the thermal stability of oleuropein and related phenolic compounds separated from olive leaf extract via salting-out-assisted cloud point extraction (CPE) was developed using Tween 80. The process was based on the decrease of the solubility of polyphenols and the lowering of the cloud point temperature of Tween 80 due to the presence of elevated amounts of sulfates (salting-out) and the separation from the bulk solution with centrifugation. The optimum conditions were chosen based on polyphenols recovery (%), phase volume ratio (Vs/Vw) and concentration factor (Fc). The maximum recovery of polyphenols was in total 95.9%; Vs/Vw was 0.075 and Fc was 15 at the following conditions: pH 2.6, ambient temperature (25 °C), 4% Tween 80 (w/v), 35% Na₂SO₄ (w/v) and a settling time of 5 min. The total recovery of oleuropein, hydroxytyrosol, luteolin-7-O-glucoside, verbascoside and apigenin-7-O-glucoside, at optimum conditions, was 99.8%, 93.0%, 87.6%, 99.3% and 100.0%, respectively. Polyphenolic compounds entrapped in the surfactant-rich phase (Vs) showed higher thermal stability (activation energy (Ea) 23.8 kJ/mol) compared to non-entrapped ones (Ea 76.5 kJ/mol). The antioxidant activity of separated polyphenols remained unaffected as determined by the 1,1-diphenyl-2-picrylhydrazyl method.

  5. Antioxidant Activity and Thermal Stability of Oleuropein and Related Phenolic Compounds of Olive Leaf Extract after Separation and Concentration by Salting-Out-Assisted Cloud Point Extraction

    Directory of Open Access Journals (Sweden)

    Konstantinos Stamatopoulos

    2014-04-01

    Full Text Available A fast, clean, energy-saving, non-toxic method for the stabilization of the antioxidant activity and the improvement of the thermal stability of oleuropein and related phenolic compounds separated from olive leaf extract via salting-out-assisted cloud point extraction (CPE was developed using Tween 80. The process was based on the decrease of the solubility of polyphenols and the lowering of the cloud point temperature of Tween 80 due to the presence of elevated amounts of sulfates (salting-out and the separation from the bulk solution with centrifugation. The optimum conditions were chosen based on polyphenols recovery (%, phase volume ratio (Vs/Vw and concentration factor (Fc. The maximum recovery of polyphenols was in total 95.9%; Vs/Vw was 0.075 and Fc was 15 at the following conditions: pH 2.6, ambient temperature (25 °C, 4% Tween 80 (w/v, 35% Na2SO4 (w/v and a settling time of 5 min. The total recovery of oleuropein, hydroxytyrosol, luteolin-7-O-glucoside, verbascoside and apigenin-7-O-glucoside, at optimum conditions, was 99.8%, 93.0%, 87.6%, 99.3% and 100.0%, respectively. Polyphenolic compounds entrapped in the surfactant-rich phase (Vs showed higher thermal stability (activation energy (Ea 23.8 kJ/mol compared to non-entrapped ones (Ea 76.5 kJ/mol. The antioxidant activity of separated polyphenols remained unaffected as determined by the 1,1-diphenyl-2-picrylhydrazyl method.

  6. Highly concentrated synthesis of copper-zinc-tin-sulfide nanocrystals with easily decomposable capping molecules for printed photovoltaic applications

    Science.gov (United States)

    Kim, Youngwoo; Woo, Kyoohee; Kim, Inhyuk; Cho, Yong Soo; Jeong, Sunho; Moon, Jooho

    2013-10-01

    Among various candidate materials, Cu2ZnSnS4 (CZTS) is a promising earth-abundant semiconductor for low-cost thin film solar cells. We report a facile, less toxic, highly concentrated synthetic method utilizing the heretofore unrecognized, easily decomposable capping ligand of triphenylphosphate, where phase-pure, single-crystalline, and well-dispersed colloidal CZTS nanocrystals were obtained. The favorable influence of the easily decomposable capping ligand on the microstructural evolution of device-quality CZTS absorber layers was clarified based on a comparative study with commonly used oleylamine-capped CZTS nanoparticles. The resulting CZTS nanoparticles enabled us to produce a dense and crack-free absorbing layer through annealing under a N2 + H2S (4%) atmosphere, demonstrating a solar cell with an efficiency of 3.6% under AM 1.5 illumination.Among various candidate materials, Cu2ZnSnS4 (CZTS) is a promising earth-abundant semiconductor for low-cost thin film solar cells. We report a facile, less toxic, highly concentrated synthetic method utilizing the heretofore unrecognized, easily decomposable capping ligand of triphenylphosphate, where phase-pure, single-crystalline, and well-dispersed colloidal CZTS nanocrystals were obtained. The favorable influence of the easily decomposable capping ligand on the microstructural evolution of device-quality CZTS absorber layers was clarified based on a comparative study with commonly used oleylamine-capped CZTS nanoparticles. The resulting CZTS nanoparticles enabled us to produce a dense and crack-free absorbing layer through annealing under a N2 + H2S (4%) atmosphere, demonstrating a solar cell with an efficiency of 3.6% under AM 1.5 illumination. Electronic supplementary information (ESI) available: Experimental methods for CZTS nanocrystal synthesis, device fabrication, and characterization; the size distribution and energy dispersive X-ray (EDX) spectra of the synthesized CZTS nanoparticles; UV-vis spectra of the

  7. Extra-Hepatic Storage of Copper

    DEFF Research Database (Denmark)

    Heydorn, Kaj; Damsgaard, Else; Horn, N.

    1975-01-01

    The distribution of copper among the organs of an aborted, male foetus, expected to develop Menkes' syndrome, was entirely different from the distribution in 4 normal foetuses. Copper concentrations determined by neutron activation analysis showed a considerably reduced content in the liver......, but increased concentrations in the other organs analysed; total foetal copper was normal....

  8. Spectral interferences in the determination of rhenium in molybdenum and copper concentrates by inductively coupled plasma optical emission spectrometry (ICP-OES)

    Science.gov (United States)

    Karadjov, Metody; Velitchkova, Nikolaya; Veleva, Olga; Velichkov, Serafim; Markov, Pavel; Daskalova, Nonka

    2016-05-01

    This paper deals with spectral interferences of complex matrix containing Mo, Al, Ti, Fe, Mg, Ca and Cu in the determination of rhenium in molybdenum and copper concentrates by inductively coupled plasma optical emission spectrometry (ICP-OES). By radial viewing 40.68 MHz ICP equipped with a high resolution spectrometer (spectral bandwidth = 5 pm) the hyperfine structure (HFS) of the most prominent lines of rhenium (Re II 197.248 nm, Re II 221.426 nm and Re II 227.525 nm) was registered. The HFS components under high resolution conditions were used as separate prominent line in order to circumvent spectral interferences. The Q-concept was applied for quantification of spectral interferences. The quantitative databases for the type and the magnitude of the spectral interferences in the presence of above mentioned matrix constituents were obtained by using a radial viewing 40.68 MHz ICP with high resolution and an axial viewing 27.12 MHz ICP with middle resolution. The data for the both ICP-OES systems were collected chiefly with a view to spectrochemical analysis for comparing the magnitude of line and wing (background) spectral interference and the true detection limits with spectroscopic apparatus with different spectral resolution. The sample pretreatment methods by sintering with magnesium oxide and oxidizing agents as well as a microwave acid digestion were applied. The feasibility, accuracy and precision of the analytical results were experimentally demonstrated by certified reference materials.

  9. Industrial experiment of copper electrolyte purification by copper arsenite

    Institute of Scientific and Technical Information of China (English)

    ZHENG Ya-jie; XIAO Fa-xin; WANG Yong; LI Chun-hua; XU Wei; JIAN Hong-sheng; MA Yut-ian

    2008-01-01

    Copper electrolyte was purified by copper arsenite that was prepared with As2O3. And electrolysis experiments of purified electrolyte were carried out at 235 and 305 A/m2, respectively. The results show that the yield of copper arsenite is up to 98.64% when the molar ratio of Cu to As is 1.5 in the preparation of copper arsenite. The removal rates of Sb and Bi reach 74.11% and 65.60% respectively after copper arsenite is added in electrolyte. The concentrations of As, Sb and Bi in electrolyte nearly remain constant during electrolysis of 13 d. The appearances of cathode copper obtained at 235 and 305 A/m2 are slippery and even, and the qualification rate is 100% according to the Chinese standard of high-pure cathode copper(GB/T467-97).

  10. EFFECT OF COPPER ON PASSIVITY AND CORROSION ...

    African Journals Online (AJOL)

    2014-06-30

    Jun 30, 2014 ... metallic copper enriched on the surface film of austenitic stainless ... Dispersed inclusions of this phase can influence the stability of .... two microstructures showed that copper concentration possessed a non-uniform chemical.

  11. Epibrassinolide induces changes in indole-3-acetic acid, abscisic acid and polyamine concentrations and enhances antioxidant potential of radish seedlings under copper stress.

    Science.gov (United States)

    Choudhary, Sikander Pal; Bhardwaj, Renu; Gupta, Bishan Datt; Dutt, Prabhu; Gupta, Rajinder Kumar; Biondi, Stefania; Kanwar, Mukesh

    2010-11-01

    In the present study, the effects of epibrassinolide (EBL) on indole-3-acetic acid (IAA), abscisic acid (ABA) and polyamine (PA) tissue concentrations and antioxidant potential of 7-day-old Raphanus sativus L. cv. 'Pusa chetki' seedlings grown under Cu stress were investigated. EBL treatment alone or in combination with Cu enhanced free and bound IAA titers when compared with the metal alone. Modest increases in free and bound ABA contents were observed for EBL treatment alone. However, the combination of EBL with Cu caused major increases in both forms of ABA, over Cu alone. Among the PAs analyzed, only putrescine and cadaverine concentrations were enhanced by EBL treatment alone. By contrast, a significant decline in putrescine and spermine contents was found in seedlings treated with EBL plus Cu. EBL treatments alone or in combination with Cu enhanced activities of guaiacol peroxidase (EC1.11.1.7), catalase (EC 1.11.1.6), superoxide dismutase (EC 1.15.1.1) and glutathione reductase (EC 1.6.4.2) and protein contents in comparison with metal and control treatments. A major decrease in malondialdehyde content was also recorded for EBL treatments with or without Cu. An increase in phytochelatin content was also observed in seedlings treated with EBL alone or in combination with Cu. Major improvement in radical scavenging activities, as attested by the antioxidant activity assay using DPPH (1,1-diphenylpicrylhydrazyl), and elevated deoxyribose and reducing powers, along with increased contents of ascorbic acid, total phenols and proline, also suggest a major influence of EBL application in mitigating copper-induced oxidative stress in radish seedlings. Copyright © Physiologia Plantarum 2010.

  12. Copper, cadmium, and zinc concentrations in juvenile Chinook salmon and selected fish-forage organisms (aquatic insects) in the upper Sacramento River, California

    Science.gov (United States)

    Saiki, Michael K.; Martin, Barbara A.; Thompson, Larry D.; Walsh, Daniel

    2001-01-01

    This study assessed the downstream extent andseverity of copper (Cu), cadmium (Cd), and zinc (Zn)contamination from acid mine drainage on juvenile chinook salmon(Oncorhynchus tshawytscha) and aquatic insects over aroughly 270-km reach of the Sacramento River below KeswickReservoir. During April–May 1998, salmon were collected fromfour sites in the river and from a fish hatchery that receiveswater from Battle Creek. Salmon from river sites were examinedfor gut contents to document their consumption of variousinvertebrate taxa, whereas salmon from river sites and thehatchery were used for metal determinations. Midge(Chironomidae) and caddisfly (Trichoptera) larvae and mayfly(Ephemeroptera) nymphs were collected for metal determinationsduring April–June from river sites and from Battle and Buttecreeks. The fish hatchery and Battle and Butte creeks served asreference sites because they had no history of receiving minedrainage. Salmon consumed mostly midge larvae and pupae (44.0%,damp-dry biomass), caddisfly larvae (18.9%), Cladocera (5.8%),and mayfly nymphs (5.7%). These results demonstrated thatinsects selected for metal determinations were important as fishforage. Dry-weight concentrations of Cu, Cd, and Zn weregenerally far higher in salmon and insects from the river thanfrom reference sites. Within the river, high metalconcentrations persisted as far downstream as South Meridian (thelowermost sampling site). Maximum concentrations of Cd (30.7 μg g-1) and Zn (1230 μg g-1),but not Cu (87.4 μg g-1), in insects exceeded amounts that other investigators reported as toxic when fed for prolonged periods to juvenile salmonids.

  13. Copper hypersensitivity

    DEFF Research Database (Denmark)

    Fage, Simon W; Faurschou, Annesofie; Thyssen, Jacob P

    2014-01-01

    hypersensitivity, a database search of PubMed was performed with the following terms: copper, dermatitis, allergic contact dermatitis, contact hypersensitivity, contact sensitization, contact allergy, patch test, dental, IUD, epidemiology, clinical, and experimental. Human exposure to copper is relatively common...

  14. Production of ultrahigh purity copper using waste copper nitrate solution.

    Science.gov (United States)

    Choi, J Y; Kim, D S

    2003-04-25

    The production of ultrahigh purity copper (99.9999%) by electrolysis in the presence of a cementation barrier has been attempted employing a waste nitric copper etching solution as the electrolyte. The amount of copper deposited on the cathode increased almost linearly with electrolysis time and the purity of copper was observed to increase as the electrolyte concentration was increased. At some point, however, as the electrolyte concentration increased, the purity of copper decreased slightly. As the total surface area of cementation barrier increased, the purity of product increased. The electrolyte temperature should be maintained below 35 degrees C in the range of investigated electrolysis conditions to obtain the ultrahigh purity copper. Considering that several industrial waste solutions contain valuable metallic components the result of present study may support a claim that electrowinning is a very desirable process for their treatment and recovery.

  15. Nano-level determination of copper with atomic absorption spectrometry after pre-concentration on N,N-(4-methyl-1,2-phenylene)diquinoline-2-carboxamide-naphthalene

    Energy Technology Data Exchange (ETDEWEB)

    Rezaei, Behzad, E-mail: rezaei@cc.iut.ac.ir [Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Sadeghi, Elham; Meghdadi, Soraia [Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of)

    2009-09-15

    A novel, simple, sensitive and effective method has been developed for selective extraction and pre-concentration of copper on N,N-(4-methyl-1,2-phenylene)diquinoline-2-carboxamide-naphthalene. After pre-concentration, copper was eluted from sorbent with hydrochloric acid, and then flame atomic absorption spectrometry (FAAS) was used for its determination. The effect of pH, sample flow rate and the volume and concentration of eluent on the recovery of the analyte was investigated and the optimum conditions were established. A pre-concentration factor of 400, and an adsorption capacity of 6.9 mg g{sup -1} of the solid-phase sorbent or 82.8 mg g{sup -1} of ligand was achieved using the optimum conditions. The calibration graph was linear in the range of 1.0-4000 ng mL{sup -1} with the detection limit of 1.0 ng mL{sup -1}. A R.S.D. value of 2.4% was obtained by this method for 400 ng mL{sup -1} of Cu{sup 2+} solution. This procedure has been successfully applied to separate and determine the ultra trace levels of copper in the environmental samples, free from the interference of some diverse ions.

  16. Comprehensive Recovery of Copper,Gold and Sulfide from Copper-Gold Concentrates Using Wet Method with Ultra-fine Grinding Technology%超细磨技术在铜金精矿湿法综合回收铜金硫中的应用研究

    Institute of Scientific and Technical Information of China (English)

    张文波; 董常平; 陈庆根; 李晓伟

    2013-01-01

    对于某矿山浮选产出的铜金精矿,由于铜的影响及黄铜矿和黄铁矿等物质对金的包裹作用的影响,直接氰化浸出的金、铜回收率均很低,虽然采用火法工艺处理该类精矿可较好地解决金、铜回收率低的问题,但是存在环境污染等问题。重点对铜金精矿超细磨-热压浸出-萃取-电积提取铜、浸出渣硫代硫酸钠法提取金和煤油溶解回收单质硫的综合回收工艺进行了研究,结果表明应用该综合回收工艺之后,铜、金和单质硫的回收率分别达到95%、98%和99%,具有有价金属综合回收率高且对环境污染小的优点。%As the impact of the copper and the chalcopyrite and pyrite inclusions of gold,the copper-gold concentrate which is the output of a mining flotation was cyanided directly,and the recoveries of gold and copper were very low.Although the problem can be solved by using pyrometallurgical processes dealing with the concentrates,but that cause environmental pollution and other issues.The copper-gold concentrate comprehensive recovery process was studied,which extracting copper from copper-gold concentrate using the process of ultra-fine grinding-hot leaching-extraction-electrowinning,extracting gold from leach residue using sodium thiosulfate method,recovering elemental sulfur using kerosene dissolved.The process has a lot of advantages,such as high recovery of valuable metals and environment friendly.The recovery rate of copper,gold and sulfur are up to 95%, 98%and 99%respectively.

  17. Impacts of aerosol particles on the microphysical and radiative properties of stratocumulus clouds over the southeast Pacific Ocean

    Science.gov (United States)

    Twohy, C. H.; Anderson, J. R.; Toohey, D. W.; Andrejczuk, M.; Adams, A.; Lytle, M.; George, R. C.; Wood, R.; Saide, P.; Spak, S.; Zuidema, P.; Leon, D.

    2013-03-01

    The southeast Pacific Ocean is covered by the world's largest stratocumulus cloud layer, which has a strong impact on ocean temperatures and climate in the region. The effect of anthropogenic sources of aerosol particles on the stratocumulus deck was investigated during the VOCALS field experiment. Aerosol measurements below and above cloud were made with a ultra-high sensitivity aerosol spectrometer and analytical electron microscopy. In addition to more standard in-cloud measurements, droplets were collected and evaporated using a counterflow virtual impactor (CVI), and the non-volatile residual particles were analyzed. Many flights focused on the gradient in cloud properties on an E-W track along 20° S from near the Chilean coast to remote areas offshore. Mean statistics, including their significance, from eight flights and many individual legs were compiled. Consistent with a continental source of cloud condensation nuclei, below-cloud accumulation-mode aerosol and droplet number concentration generally decreased from near shore to offshore. Single particle analysis was used to reveal types and sources of the enhanced particle number that influence droplet concentration. While a variety of particle types were found throughout the region, the dominant particles near shore were partially neutralized sulfates. Modeling and chemical analysis indicated that the predominant source of these particles in the marine boundary layer along 20° S was anthropogenic pollution from central Chilean sources, with copper smelters a relatively small contribution. Cloud droplets were smaller in regions of enhanced particles near shore. However, physically thinner clouds, and not just higher droplet number concentrations from pollution, both contributed to the smaller droplets. Satellite measurements were used to show that cloud albedo was highest 500-1000 km offshore, and actually slightly lower closer to shore due to the generally thinner clouds and lower liquid water paths

  18. Spectral evolution of star clusters in the Large Magellanic Cloud: I. Blue concentrated clusters in the age range 40-300 Myr

    CERN Document Server

    Santos, J F C; Ahumada, A V; Bica, E; Piatti, A E; Parisi, M C

    2005-01-01

    Integrated spectroscopy of a sample of 17 blue concentrated Large Magellanic Cloud (LMC) clusters is presented and its spectral evolution studied. The spectra span the range ~3600-6800A with a resolution of ~14A FWHM, being used to determine cluster ages and, in connection with their spatial distribution, to explore the LMC structure and cluster formation history. Cluster reddening values were estimated by interpolation, using the available extinction maps. We used two methods to derive cluster ages: (i) template matching, in which line strengths and continuum distribution of the cluster spectra were compared and matched to those of template clusters with known astrophysical properties, and (ii) equivalent width (EW) method, in which new age/metallicity calibrations were used together with diagnostic diagrams involving the sum of EWs of selected spectral lines (KCaII, G band (CH), MgI, Hdelta, Hgamma and Hbeta). The derived cluster ages range from 40Myr (NGC2130 and SL237) to 300Myr (NGC1932 and SL709), a goo...

  19. Determination of lead, cadmium, copper, and nickel in the tonghui river of beijing, china, by cloud point extraction-high resolution continuum source graphite furnace atomic absorption spectrometry.

    Science.gov (United States)

    Ren, Ting; Zhao, Li-Jiao; Sun, Bo-Si; Zhong, Ru-Gang

    2013-11-01

    Heavy metal contamination of water has become an important problem in recent years. Most hazardous heavy metals exist in environmental water in trace or ultra-trace amounts, which requires establishing highly sensitive analytical methods. In this research, quantitative analyses were performed using high-resolution continuum source graphite furnace atomic absorption spectrometry combined with cloud point extraction (CPE) to determine Pb, Cd, Cu, and Ni levels in environmental surface water. By optimizing the CPE conditions, the enrichment factors were 29 for Pb, Cd, and Cu and 25 for Ni. The limits of detection (LOD) were 0.080, 0.010, 0.035, and 0.014 μg L for Pb, Cd, Cu, and Ni, respectively. The sensitivity of the method is comparable with those reported in previous investigations using various methods and improves outcome by 2 to 3 orders of magnitude compared with the LODs of the current national standard methods of China. Our method was used to determine Pb, Cd, Cu, and Ni in 55 water samples collected from the Tonghui River, which is the principal river in the urban area of Beijing, China. The results indicated that the distributions of the four heavy metals in the Tonghui River were related with the environments. The levels of Pb and Ni exhibit increasing trends along the river from upstream to downstream possibly due to the existence of some chemical factories in the downstream area. Lead, Cd, Cu, and Ni averaged 13.9, 0.8, 46.8, and 38.5%, respectively, of the total amount of the determined heavy metals. The levels of the four heavy metals conformed to the Environmental Quality Standards for Surface Water (Grade I) of China. This work provides a reliable quantitative method to determine trace-amount heavy metals in water, which lays a foundation for establishing standards and regulations for environmental water protection.

  20. Rapid Determination of Silicon Dioxide Content in Copper Concentrate%铜精矿中二氧化硅含量的快速测定

    Institute of Scientific and Technical Information of China (English)

    戚月花; 张淑玲; 李先和; 万双; 崔鲁

    2016-01-01

    Content of silicon dioxide in copper concentrate was determined by alkali fused silica molybdenum blue spectrophotometric method. It was discussed about the solution conditions, absorption wavelength, solution acidity, water bath time, color and coexisting ions interference conditions on the influence of the absorbance. Sodium hydroxide as solvent,melting for 15 min at 680℃,melting sample effect was the best. The wavelength was selected according to the content of silicon dioxide in sample, detection wavelength was set of 810 nm for the silicon dioxide content of less than 1%, detection wavelength was set of 650 nm for the content of 1%–15%;the color effect was the best with hydrochloric acid solution of 0.15–0.20 mol/L, water bath heating of 60 s,color time of 15 min. Ammonium ferric sulfate was used as a reducing agent. The recoveries of standard addition was between 94.8%–98.8%, the relative standard deviations of five independent sample determination results were 0.26%–4.48%(n=11), the results in standard sample were consistent with the certified values. The method is simple, rapid, accurate and suitable for the determination of silicon dioxide content in the copper concentrate.%采用碱熔样硅钼蓝分光光度法测定铜精矿中二氧化硅的含量。讨论了熔融条件、吸收波长、溶液酸度、水浴加热时间、显色时间以及共存离子干扰等条件对测定结果的影响。确定以氢氧化钠为熔剂,在680℃熔融15 min,熔样效果最佳;根据样品中二氧化硅的含量选择波长,当二氧化硅含量小于1%时,选用810 nm为分析波长,二氧化硅含量为1%~15%时,选用650 nm为分析波长;在酸度为0.15~0.20 mol/L盐酸溶液中,水浴加热60 s,显色15 min,显色效果为最佳。使用硫酸亚铁铵作为还原剂。方法的加标回收率在94.8%~98.8%之间,5个样品独立测定结果的相对标准偏差为0.26%~4.48%(n=11),标准样品测定结果与标

  1. Simultaneous determination of antimony and boron in beverage and dairy products by flame atomic absorption spectrometry after separation and pre-concentration by cloud-point extraction.

    Science.gov (United States)

    Altunay, Nail; Gürkan, Ramazan

    2016-01-01

    A new cloud-point extraction (CPE) method was developed for the pre-concentration and simultaneous determination of Sb(III) and B(III) by flame atomic absorption spectrometry (FAAS). The method was based on complexation of Sb(III) and B(III) with azomethine-H in the presence of cetylpyridinium chloride (CPC) as a signal-enhancing agent, and then extraction into the micellar phase of Triton X-114. Under optimised conditions, linear calibration was obtained for Sb(III) and B(III) in the concentration ranges of 0.5-180 and 2.5-600 μg l(-1) with LODs of 0.15 and 0.75 μg l(-1), respectively. Relative standard deviations (RSDs) (25 and 100 μg l(-1) of Sb(III) and B(III), n = 6) were in a range of 2.1-3.8% and 1.9-2.3%, respectively. Recoveries of spiked samples of Sb(III) and B(III) were in the range of 98-103% and 99-102%, respectively. Measured values for Sb and B in three standard reference materials were within the 95% confidence limit of the certified values. Also, the method was used for the speciation of inorganic antimony. Sb(III), Sb(V) and total Sb were measured in the presence of excess boron before and after pre-reduction with an acidic mixture of KI-ascorbic acid. The method was successfully applied to the simultaneous determination of total Sb and B in selected beverage and dairy products.

  2. Closure between ice-nucleating particle and ice crystal number concentrations in ice clouds embedded in Saharan dust: Lidar observation during the BACCHUS Cyprus 2015 campaign

    Science.gov (United States)

    Mamouri, Rodanthi-Elisavet; Ansmann, Albert; Bühl, Johannes; Engelmann, Ronny; Baars, Holger; Nisantzi, Argyro; Hadjimitsis, Diofantos; Atkinson, James; Kanji, Zamin; Vrekoussis, Michalis; Sciare, Jean; Mihalopoulos, Nikos

    2016-04-01

    For the first time, we compare ice-nucleating particle number concentration (INPC) derived from polarization lidar (Mamouri and Ansmann, 2015) with ice crystal number concentrations (ICNC) in ice cloud layers embedded in the observed Saharan dust layers (at heights above 6 km and corresponding temperatures from -20 to -40°C). ICNC is estimated from the respective cirrus extinction profiles obtained with the same polarization lidar in combination with Doppler lidar measurements of the ice crystal sedimentation speed from which the mean size of the crystals can be estimated. Good agreement between INPC and ICNC was obtained for two case studies of the BACCHUS Cyprus 2015 field campaign with focus on INPC profiling. The campaign was organized by the Cyprus Institute, Nicosia, where a lidar was deployed. Additionaly, observations of AERONET and EALINET Lidar stations during the BACCHUS Cyprus 2015 field campaign, performed by Cyprus University of Technology in Limassol. Both, INPC and ICNC were found in the range from 10-50 1/L. Lidar-derived INPC values were also compared with in-situ INPC measurements (Horizontal Ice Nucleation Chamber, HINC, ETH Zurich, deployed at Agia Marina, at 500 m a.s.l., 30 km west of the lidar site). Reasonable and partly good agreement (during dust events) was found between the two retrievals. The findings of these closure studies corroborate the applicability of available INPC parameterization schemes (DeMott et al., 2010, 2015) implemented in the lidar retrieval scheme, and more generally INPC profiling by using active remote sensing (at ground and in space with CALIPSO and EarthCARE lidars).

  3. Hair copper in intrauterine copper device users.

    Science.gov (United States)

    Thiery, M; Heyndrickx, A; Uyttersprot, C

    1984-03-01

    The antifertility effect of copper-bearing IUDs is based on continuous release of copper, which is a result of the reaction between the metal and the uterine secretions. Released cupric ions collect in the endometrium and in the uterine fluid but significant accumulation has not been found in the bloodstream or elsewhere. Following Laker's suggestion that hair be used for monitoring essential trace elements, e.g., copper, we checked the copper content of the hair of women wearing copper-bearing IUDs. Samples of untreated pubic hair removed by clipping before diagnostic curettage were obtained from 10 young (24-34 years old), white caucasian females who until then had been wearing an MLCu250 IUD for more than 1 year. Pubes from 10 comparable (sex, age, race) subjects who had never used a Cu-containing device served as controls. The unwashed material was submitted to the toxicology laboratory, where the copper content was assessed by flameless atomic absorption, a technique whose lower limit of measurement lies at a concentration of 0.05 mcg Cu/ml fluid (50 ppb). Hair samples were washed to remove extraneous traces of metal according to the prescriptions of the International Atomic Energy Agency, weighed, and mineralized, after which a small volume (10 mcl) of the diluted fluid was fed into the graphite furnace. Each sample (75-150 mg) was analyzed 4 times, both before and after washing. Since the cleaning procedure reduces the weight of the sample (mainly by the removal of fat, dust, etc.) this explains why the percentage copper content of washed hair is higher than that of unwashed hair belonging to the same subject. The results indicate that there was no significant difference (Mann-Whitney U test) between the mean copper levels of both unwashed and washed pubes from women who were using or had never used an MLCu250 IUD. We therefore conclude that the use of this copper-containing device is not associated with significant accumulation of copper in (pubic) hair.

  4. Synthesis of copper/copper oxide nanoparticles by solution plasma

    Science.gov (United States)

    Saito, Genki; Hosokai, Sou; Tsubota, Masakatsu; Akiyama, Tomohiro

    2011-07-01

    This paper describes the synthesis of copper/copper oxide nanoparticles via a solution plasma, in which the effect of the electrolyte and electrolysis time on the morphology of the products was mainly examined. In the experiments, a copper wire as a cathode was immersed in an electrolysis solution of a K2CO3 with the concentration from 0.001 to 0.50 M or a citrate buffer (pH = 4.8), and was melted by the local-concentration of current. The results demonstrated that by using the K2CO3 solution, we obtained CuO nanoflowers with many sharp nanorods, the size of which decreased with decreasing the concentration of the solution. Spherical particles of copper with/without pores formed when the citrate buffer was used. The pores in the copper nanoparticles appeared when the applied voltage changed from 105 V to 130 V, due to the dissolution of Cu2O.

  5. Determination of cadmium(II), cobalt(II), nickel(II), lead(II), zinc(II), and copper(II) in water samples using dual-cloud point extraction and inductively coupled plasma emission spectrometry.

    Science.gov (United States)

    Zhao, Lingling; Zhong, Shuxian; Fang, Keming; Qian, Zhaosheng; Chen, Jianrong

    2012-11-15

    A dual-cloud point extraction (d-CPE) procedure has been developed for simultaneous pre-concentration and separation of heavy metal ions (Cd2+, Co2+, Ni2+, Pb2+, Zn2+, and Cu2+ ion) in water samples by inductively coupled plasma optical emission spectrometry (ICP-OES). The procedure is based on forming complexes of metal ion with 8-hydroxyquinoline (8-HQ) into the as-formed Triton X-114 surfactant rich phase. Instead of direct injection or analysis, the surfactant rich phase containing the complexes was treated by nitric acid, and the detected ions were back extracted again into aqueous phase at the second cloud point extraction stage, and finally determined by ICP-OES. Under the optimum conditions (pH=7.0, Triton X-114=0.05% (w/v), 8-HQ=2.0×10(-4) mol L(-1), HNO3=0.8 mol L(-1)), the detection limits for Cd2+, Co2+, Ni2+, Pb2+, Zn2+, and Cu2+ ions were 0.01, 0.04, 0.01, 0.34, 0.05, and 0.04 μg L(-1), respectively. Relative standard deviation (RSD) values for 10 replicates at 100 μg L(-1) were lower than 6.0%. The proposed method could be successfully applied to the determination of Cd2+, Co2+, Ni2+, Pb2+, Zn2+, and Cu2+ ion in water samples.

  6. Seasonal Changes in Copper and Cobalt Concentrations of Pinus nigra L.,Cedrus libani and Cupressus arizonica Leaves to Monitor the Effects of Pollution in Elazig(Turkey)%Seasonal Changes in Copper and Cobalt Concentrations of Pinus nigra L., Cedrus libani and Cupressus arizonica Leaves to Monitor the Effects of Pollution in Elazig(Turkey)

    Institute of Scientific and Technical Information of China (English)

    Nagihan M Karaaslan; Mehmet Yaman

    2013-01-01

    The aim of this study is to examine seasonal changes in Cu and Co concentrations of three plant species for monitoring the effects of pollution in Elazig,Turkey.For this purpose,the leaves of the Pinus nigra L.,Cedrus libani and Cupressus arizonica together with soil samples were collected from different points depending on traffic intensity,nearness the city center and cement factory as well as control location during different months of the year.Flame atomic absorption spectrophotometer(FAAS) was used for measurement of the metals in clear digests after the dry ashing method.Copper and Co concentrations were in the ranges from 1.3 to 2.6 mg · kg-1 and <LOD to 0.26 mg · kg-1 for Pinusnigra L.,1.2 to 4.7 mg · kg-1 and <LOD to 0.41 mg · kg-1 for Cedrus libani and 1.5 to 4.8 mg · kg-1 and <LOD to 0.42 mg · kg-1 for Cupressusarizonica,respectively.The levels observed for Cu and Co in the soil ranged from 12 to 38 mg · kg-1 and 6.0 to 17 mg· kg-1,respectively.

  7. Study on high pressure sealed microwave digestion method of copper concentrate samples%铜精矿样品的高压密封微波消解方法研究

    Institute of Scientific and Technical Information of China (English)

    杨丽飞; 苏明跃; 郭芬

    2011-01-01

    A high pressure sealed microwave digestion technique was studied for composition analysis in copper concentrate samples. According to their mineral composition and phase structure,the copper concentrate samples with high content of organic matters, silicon and metallic oxide were used for testing. The experimental content included types and dosage of digestion reagent, the conditions to fully digest the sample, etc. A high pressure sealed microwave digestion method based on the experimental results was established, which was applicable for the chemical composition analysis of copper concentrate. By the complete digestion test of copper concentrate samples with different mineral composition and phase structure, we proved the applicability of this method. The copper concentrate was digested by this method. Then, arsenic, mercury, lead and cadmium were determined by ICP-AES, and fluorine in testing solution was determined by fluorine ion selective electrode method. The analytical results were consistent with those obtained by national standard method.%研究了采用高压密封微波消解技术消解用于成分分析的铜精矿样品的方法.依据铜精矿矿物组成、物相结构,分别选取了有机物含量高、硅含量高和金属氧化物含量高的样品进行试验,试验内容包括消解试剂种类和用量选择,样品完全消解的条件等.根据研究结果建立了适于铜精矿化学成分分析的高压密封微波消解方法.通过对不同矿物组分、不同物相结构的铜精矿样品的完全消解验证实验,证明了该消解方法的实用性.采用该方法消解铜精矿,然后用ICP-AES法检测试液中砷、汞、铅、镉和氟离子选择电极法检测试液中氟,分析结果与国家标准方法的测定结果一致.

  8. Mercury: its iron and sulfur enrichment has roots in mechanical concentration of dense particles in the inner part of rotating primordial gas-dust cloud

    Science.gov (United States)

    Kochemasov, G. G.

    2013-09-01

    After MESSENGER explorations one could crystallize an idea of nature of this innermost planet of the Solar system. It has on the whole dull low albedo surface with small variations in compositions of Mg-rich Fe-poor large tectonic units. Only widespread small hollows and their groups with darker and brighter haloes brighten this dull landscape. The relief variations are small (maximum 10 km, but normally within 3-5 km), much less than on other rocky planets. The large iron core making the planet's density high leaves a modest place for mantle. Atmosphere is practically absent notwithstanding strong degassing, and this is due to strong cleaning by the solar wind. All mentioned peculiarities could be explained by the Mercury's position in the innermost zone. This was done even before the first orbital explorations just on a basis of the wave planetology connecting planets' properties with their orbital characteristics [ 1, 2]. Surprising many planetologists the high sulfur presence in Mercury, not justified by its position in the hot inner zone was, however, practically predicted by a new model of primordial matter differentiation in a rotating gas-dust cloud [ 3, 4]. This cloud consisting of gas and mixture of solids with various densities under rotation produces concentration of heavy particles in the inner zone. This process is well known for prospectors making heavy concentrations (schlich) with use of a spiral separator. There separation of heavies is made by descending and rotating in a spiral water-sand mixture. This model for differentiation of a planetary system was presented at LPSC [3, 4]. At that time nobody could imagine volatile sulfur in the inner hot zone. In [1] is written "It is suggested that primary accretion minerals in some meteorites and probably also in the larger bodies of the Solar system are united by nearness of their densities rather than by temperatures of their condensation out of the protoplanet gas (for example, common association of

  9. Determination of cadmium(II), cobalt(II), nickel(II), lead(II), zinc(II), and copper(II) in water samples using dual-cloud point extraction and inductively coupled plasma emission spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Lingling; Zhong, Shuxian; Fang, Keming; Qian, Zhaosheng [College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua 321004 (China); Chen, Jianrong, E-mail: cjr@zjnu.cn [College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua 321004 (China); College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004 (China)

    2012-11-15

    Highlights: Black-Right-Pointing-Pointer A dual-cloud point extraction (d-CPE) procedure was firstly developed for simultaneous pre-concentration and separation of trace metal ions combining with ICP-OES. Black-Right-Pointing-Pointer The developed d-CPE can significantly eliminate the surfactant of Triton X-114 and successfully extend to the determination of water samples with good performance. Black-Right-Pointing-Pointer The designed method is simple, high efficient, low cost, and in accordance with the green chemistry concept. - Abstract: A dual-cloud point extraction (d-CPE) procedure has been developed for simultaneous pre-concentration and separation of heavy metal ions (Cd{sup 2+}, Co{sup 2+}, Ni{sup 2+}, Pb{sup 2+}, Zn{sup 2+}, and Cu{sup 2+} ion) in water samples by inductively coupled plasma optical emission spectrometry (ICP-OES). The procedure is based on forming complexes of metal ion with 8-hydroxyquinoline (8-HQ) into the as-formed Triton X-114 surfactant rich phase. Instead of direct injection or analysis, the surfactant rich phase containing the complexes was treated by nitric acid, and the detected ions were back extracted again into aqueous phase at the second cloud point extraction stage, and finally determined by ICP-OES. Under the optimum conditions (pH = 7.0, Triton X-114 = 0.05% (w/v), 8-HQ = 2.0 Multiplication-Sign 10{sup -4} mol L{sup -1}, HNO{sub 3} = 0.8 mol L{sup -1}), the detection limits for Cd{sup 2+}, Co{sup 2+}, Ni{sup 2+}, Pb{sup 2+}, Zn{sup 2+}, and Cu{sup 2+} ions were 0.01, 0.04, 0.01, 0.34, 0.05, and 0.04 {mu}g L{sup -1}, respectively. Relative standard deviation (RSD) values for 10 replicates at 100 {mu}g L{sup -1} were lower than 6.0%. The proposed method could be successfully applied to the determination of Cd{sup 2+}, Co{sup 2+}, Ni{sup 2+}, Pb{sup 2+}, Zn{sup 2+}, and Cu{sup 2+} ion in water samples.

  10. Determination of copper in clarified apple juices.

    Science.gov (United States)

    Zeiner, Michaela; Juranović Cindrić, Iva; Kröppl, Michaela; Stingeder, Gerhard

    2010-03-24

    Inorganic copper compounds are not considered as synthetic fertilizers for apple trees as they are traditional fertilizers. Thus, they are used in organic farming for soil or foliar applications. The European Union is for health reasons interested in reducing copper in apple orchards. Because the fertilizer application rate affects the nutrition of apples, the applied copper might also be reflected in the copper concentration of apple juices. Thus, the determination of copper is of concern for investigating the application of copper-containing fertilizers. Samples of clarified apple juice commercially available in the European market were analyzed for their copper content. Prior to quantification by inductively coupled plasma-optical emission spectrometry, the juices were processed by a microwave-assisted digestion system using HNO(3). All samples were also measured directly after dilution with HNO(3). The copper concentrations measured using both methods were all below the limit of detection (17 microg/L).

  11. Assessments of serum copper and zinc concentration, and the Cu/Zn ratio determination in patients with multidrug resistant pulmonary tuberculosis (MDR-TB) in Côte d'Ivoire.

    Science.gov (United States)

    Bahi, Gnogbo Alexis; Boyvin, Lydie; Méité, Souleymane; M'Boh, Gervais Melaine; Yeo, Kadjowely; N'Guessan, Kouassi Raymond; Bidié, Alain Dit Philippe; Djaman, Allico Joseph

    2017-04-11

    In Côte d'Ivoire, multidrug-resistant tuberculosis (MDR-TB) is a serious public health problem with a prevalence estimated at 2.5% in 2006. Zinc and copper are essential Trace element needed to strengthen the immune system and also useful in the fight against tuberculosis. The Cu / Zn ratio is a good indicator of oxidative stress. The principal aim of this study was to evaluate the serum concentration of some trace element and determine the Cu / Zn ratio in patients with multidrug resistant pulmonary tuberculosis (MDR-TB) before and after second line treatment of TB. Blood samples were obtained from 100 MDR-TB patients after confirmation of their status through the microscopic and molecular diagnosis of resistance to Isoniazid and Rifampicin by GeneXpert. The concentration level of zinc and copper were determined using flame air / acetylene atomic absorption spectrometer (AAS) Type Varian Spectr AA-20 Victoria, Australlia. A significant decrease in zinc levels (P TB patients compared to controls TB free. During treatment a significant reduction in Cu / Zn ratio (P TB. Therefore the evaluation of the zinc and copper status could represent essential parameters in monitoring of TB second line treatment for better treatment management.

  12. Cloud Governance

    DEFF Research Database (Denmark)

    Berthing, Hans Henrik

    Denne præsentation beskriver fordele og værdier ved anvendelse af Cloud Computing. Endvidere inddrager resultater fra en række internationale analyser fra ISACA om Cloud Computing.......Denne præsentation beskriver fordele og værdier ved anvendelse af Cloud Computing. Endvidere inddrager resultater fra en række internationale analyser fra ISACA om Cloud Computing....

  13. Electroleaching of Copper Waste with Recovery of Copper by Electrodialysis

    Directory of Open Access Journals (Sweden)

    Nuñez P.

    2013-04-01

    Full Text Available A new process to leach and recover copper from solid waste using electric fields was designed. The leaching with electro migration is presented as an alternative to traditional leaching. Preliminary data indicate that the copper ion migration is facilitated by using the electrical potential difference; therefore applying a potential difference in the processes of leaching facilitates the removal of copper. This is especially useful when mineral concentrations are very low. Different phenomena associated with transport of copper in solution are studied to generate a model able predict the state of the copper ion concentration in time. A kinetic model for the process was developed and fitted very well the experimental data.

  14. Dietary Management of Labrador Retrievers with Subclinical Hepatic Copper Accumulation

    OpenAIRE

    Fieten, H.; Biourge, V.C.; Watson, A.L.; Leegwater, P.A.J.; van den Ingh, T.S.G.A.M.; Rothuizen, J.

    2015-01-01

    Background Genetic and environmental factors, including dietary copper intake, contribute to the pathogenesis of copper‐associated hepatitis in Labrador retrievers. Clinical disease is preceded by a subclinical phase in which copper accumulates in the liver. Objective To investigate the effect of a low‐copper, high‐zinc diet on hepatic copper concentration in Labrador retrievers with increased hepatic copper concentrations. Animals Twenty‐eight clinically healthy, client‐owned Labrador retrie...

  15. Cloud optics

    CERN Document Server

    Kokhanovsky, A

    2006-01-01

    Clouds affect the climate of the Earth, and they are an important factor in the weather. Therefore, their radiative properties must be understood in great detail. This book summarizes current knowledge on cloud optical properties, for example their ability to absorb, transmit, and reflect light, which depends on the clouds' geometrical and microphysical characteristics such as sizes of droplets and crystals, their shapes, and structures. In addition, problems related to the image transfer through clouds and cloud remote sensing are addressed in this book in great detail. This book can be an im

  16. On the observation of unusual high concentration of small chain-like aggregate ice crystals and large ice water contents near the top of a deep convective cloud during the CIRCLE-2 experiment

    Directory of Open Access Journals (Sweden)

    J.-F. Gayet

    2011-08-01

    Full Text Available During the CIRCLE-2 experiment carried out over Western Europe in May 2007, combined in situ and remote sensing observations allowed to describe microphysical and optical properties near-top of an overshooting convective cloud (11 080 m/−58 °C. The airborne measurements were performed with the DLR Falcon aircraft specially equipped with a unique set of instruments for the extensive in situ cloud measurements of microphysical and optical properties (Polar Nephelometer, FSSP-300, Cloud Particle Imager and PMS 2D-C and nadir looking remote sensing observations (DLR WALES Lidar. Quasi-simultaneous space observations from MSG/SEVIRI, CALIPSO/CALIOP-WFC-IIR and CloudSat/CPR combined with airborne RASTA radar reflectivity from the French Falcon aircraft flying above the DLR Falcon depict very well convective cells which overshoot by up to 600 m the tropopause level. Unusual high values of the concentration of small ice particles, extinction, ice water content (up to 70 cm−3, 30 km−1 and 0.5 g m−3, respectively are experienced. This very dense cloud causes a strong attenuation of the WALES and CALIOP lidar returns. The mean effective diameter is of 43 μm and the maximum particle size is about 300 μm. The SEVIRI retrieved parameters confirm the occurrence of small ice crystals at the top of the convective cell. Smooth and featureless phase functions with asymmetry factors of 0.776 indicate fairly uniform optical properties. Due to small ice crystals the power-law relationship between ice water content (IWC and radar reflectivity appears to be very different from those usually found in cirrus and anvil clouds. For a given equivalent reflectivity factor, IWCs are significantly larger for the overshooting cell than for the cirrus. Assuming the same prevalent microphysical properties over the depth of the overshooting cell, RASTA reflectivity profiles scaled into ice water content show that retrieved IWC up to 1 g

  17. On the observation of unusual high concentration of small chain-like aggregate ice crystals and large ice water contents near the top of a deep convective cloud during the CIRCLE-2 experiment

    Directory of Open Access Journals (Sweden)

    J.-F. Gayet

    2012-01-01

    Full Text Available During the CIRCLE-2 experiment carried out over Western Europe in May 2007, combined in situ and remote sensing observations allowed to describe microphysical and optical properties near-top of an overshooting convective cloud (11 080 m/−58 °C. The airborne measurements were performed with the DLR Falcon aircraft specially equipped with a unique set of instruments for the extensive in situ cloud measurements of microphysical and optical properties (Polar Nephelometer, FSSP-300, Cloud Particle Imager and PMS 2-D-C and nadir looking remote sensing observations (DLR WALES Lidar. Quasi-simultaneous space observations from MSG/SEVIRI, CALIPSO/CALIOP-WFC-IIR and CloudSat/CPR combined with airborne RASTA radar reflectivity from the French Falcon aircraft flying above the DLR Falcon depict very well convective cells which overshoot by up to 600 m the tropopause level. Unusual high values of the concentration of small ice particles, extinction, ice water content (up to 70 cm−3, 30 km−1 and 0.5 g m−3, respectively are experienced. The mean effective diameter and the maximum particle size are 43 μm and about 300 μm, respectively. This very dense cloud causes a strong attenuation of the WALES and CALIOP lidar returns. The SEVIRI retrieved parameters confirm the occurrence of small ice crystals at the top of the convective cell. Smooth and featureless phase functions with asymmetry factors of 0.776 indicate fairly uniform optical properties. Due to small ice crystals the power-law relationship between ice water content (IWC and radar reflectivity appears to be very different from those usually found in cirrus and anvil clouds. For a given equivalent reflectivity factor, IWCs are significantly larger for the overshooting cell than for the cirrus. Assuming the same prevalent microphysical properties over the depth of the overshooting cell, RASTA reflectivity profiles scaled into ice water content show that retrieved

  18. Preparation of selective molybdenum concentrate from collective coppermolybdenum concentrate

    Directory of Open Access Journals (Sweden)

    N. Tusupbaev

    2016-06-01

    Full Text Available The paper considers possibilities of selective separation of the concentrate of copper and molybdenum from a collective copper-molybdenum concentrate of Aktogay deposit using regrinding and conventional flotation reagents. In the case of conventional flotoreagents, the content of molybdenum in a molybdenum concentrate was 8.0% at extraction effectiveness 83.12%. At 27.96% extraction degree of copper, it’s content in the concentrate equaled to 21.3%. After regrinding, molybdenum content in the concentrate was 24.0% at the extraction effectiveness 59.63%, and copper content in the concentrate was 21.9% at the recovery of 61.23%. Thus, the regrinding of a collective copper-molybdenum concentrate resulted in an increase in the content of molybdenum in molybdenum concentrate by 16%, and the copper concentration increased by 0.6%.

  19. Aircraft measurements of wave cloud

    Directory of Open Access Journals (Sweden)

    Z. Cui

    2012-05-01

    Full Text Available In this paper, aircraft measurements are presented of liquid phase (ice-free wave clouds made at temperatures greater than −5 °C that formed over Scotland, UK. The horizontal variations of the vertical velocity across wave clouds display a distinct pattern. The maximum updraughts occur at the upshear flanks of the clouds and the strong downdraughts at the downshear flanks. The cloud droplet concentrations were a couple of hundreds per cubic centimetres, and the drops generally had a mean diameter between 15–45 μm. A small proportion of the drops were drizzle. A new definition of a mountain-wave cloud is given, based on the measurements presented here and previous studies. The results in this paper provide a case for future numerical simulation of wave cloud and the interaction between wave and clouds.

  20. The Effect of Copper

    African Journals Online (AJOL)

    higher (p<0.05) in the broodfish fed CSD0 and CSD1 diets than the other diets. Exposure of Clarias gariepinus fish to copper in water, at concentrations above 1.0mg CuSO4/g elicits adverse ... introduction of a toxicant to an aquatic system ..... Toxicity of four commonly used agrochemicals on. Oreochromis niloticus (L) fry.

  1. Copper homeostasis in Drosophila by complex interplay of import, storage and behavioral avoidance

    OpenAIRE

    Balamurugan, Kuppusamy; Egli, Dieter; Hua, Haiqing; Rajaram, Rama; Seisenbacher, Gerhard; Georgiev, Oleg; Schaffner, Walter

    2007-01-01

    Copper is an essential but potentially toxic trace element. In Drosophila, the metal-responsive transcription factor (MTF-1) plays a dual role in copper homeostasis: at limiting copper concentrations, it induces the Ctr1B copper importer gene, whereas at high copper concentrations, it mainly induces the metallothionein genes. Here we find that, despite the downregulation of the Ctr1B gene at high copper concentrations, the protein persists on the plasma membrane of intestinal cells for many h...

  2. Interstellar molecular clouds

    Science.gov (United States)

    Bally, J.

    1986-04-01

    The physical properties of the molecular phase of the interstellar medium are studied with regard to star formation and the structure of the Galaxy. Most observations of molecular clouds are made with single-dish, high-surface precision radio telescopes, with the best resolution attainable at 0.2 to 1 arcmin; the smallest structures that can be resolved are of order 10 to the 17th cm in diameter. It is now believed that: (1) most of the mass of the Galaxy is in the form of giant molecular clouds; (2) the largest clouds and those responsible for most massive star formation are concentrated in spiral arms; (3) the molecular clouds are the sites of perpetual star formation, and are significant in the chemical evolution of the Galaxy; (4) giant molecular clouds determine the evolution of the kinematic properties of galactic disk stars; (5) the total gas content is diminishing with time; and (6) most clouds have supersonic internal motions and do not form stars on a free-fall time scale. It is concluded that though progress has been made, more advanced instruments are needed to inspect the processes operating within stellar nurseries and to study the distribution of the molecular clouds in more distant galaxies. Instruments presently under construction which are designed to meet these ends are presented.

  3. CARACTERIZACIÓN DE CONCENTRADOS DE COBRE PRODUCIDOS EN ARGENTINA PARA ANALIZAR LA FACTIBILIDAD DE LA INSTALACIÓN DE UNA PLANTA PIROMETALÚRGICA CHARACTERIZATION OF THE ARGENTINE COPPER CONCENTRATES TO EVALUATE THE POSSIBILITY OF A PIROMETALLURGY INDUSTRY INSTALLATION

    Directory of Open Access Journals (Sweden)

    Vanesa Bazán

    2010-12-01

    Full Text Available La demanda mundial de cobre metálico se incrementó sensiblemente durante estos últimos años debido a los mercados emergentes y a China en particular. Actualmente en Argentina los proyectos mineros de explotación de cobre qeue se desarrollan en el norte del país concluyen su proceso con la exportación de concentrados. En nuestro país se han realizado diferentes exploraciones y en algunos casos ya están en explotación minerales de alta ley de cobre (0,5% - 0,8% libres de impurezas tales como: Sb, As, Pb, Bi y Hg. Esto indicaría que hay un gran futuro de la pirometalurgia del cobre que no se ha desarrollado aquí hasta el momento. Las condiciones del mercado argentino de cobre generan una demanda insatisfecha del metal, ya que existen plantas transformadoras de cobre metálico a productos terminados provocando una nueva importación de productos intermedios de cobre. Este trabajo propone profundizar el conocimiento y ampliar el espectro de los fundamentos técnicos con el objetivo de cubrir ese espacio del mercado. Esto puede promover que los grandes proyectos cupríferos superen la instancia de exportar concentrados proporcionando esta materia prima a una industria metalúrgica nacional que produzca cobre metálico, y de este modo evitar que se importe dicho insumo y de esta manera se satisfaga el mercado interno.The copper demand in the world has considerably increased during the last years due to the emergent markets, particularly the Chinese market. Nowadays, the mining projects for copper exploitation that are being developed in the North of Argentina conclude with the concentrates exports. In our country different explorations have been carried out and in some cases high law of copper minerals are being exploited (0,5% - 0,8%. These minerals are free from impurities such as: Sb,As,Pb,Bi and Hg. This would lead to think that there are good prospects for the copper pyrometallurgy that have not been developed yet in our country. The

  4. Evaluation of copper resistant bacteria from vineyard soils and mining waste for copper biosorption

    Directory of Open Access Journals (Sweden)

    R Andreazza

    2011-03-01

    Full Text Available Vineyard soils are frequently polluted with high concentrations of copper due application of copper sulfate in order to control fungal diseases. Bioremediation is an efficient process for the treatment of contaminated sites. Efficient copper sorption bacteria can be used for bioremoval of copper from contaminated sites. In this study, a total of 106 copper resistant bacteria were examined for resistance to copper toxicity and biosorption of copper. Eighty isolates (45 from vineyard Mollisol, 35 from Inceptisol were obtained from EMBRAPA (Empresa Brasileira de Pesquisa Agropecuária experimental station, Bento Gonçalves, RS, Brazil (29º09'53.92''S and 51º31'39.40''W and 26 were obtained from copper mining waste from Caçapava do Sul, RS, Brazil (30º29'43.48''S and 53'32'37.87W. Based on resistance to copper toxicity and biosorption, 15 isolates were identified by 16S rRNA gene sequencing. Maximal copper resistance and biosorption at high copper concentration were observed with isolate N2 which removed 80 mg L-1 in 24 h. Contrarily isolate N11 (Bacillus pumilus displayed the highest specific copper biosorption (121.82 mg/L/OD unit in 24 h. GenBank MEGABLAST analysis revealed that isolate N2 is 99% similar to Staphylococcus pasteuri. Results indicate that several of our isolates have potential use for bioremediation treatment of vineyards soils and mining waste contaminated with high copper concentration.

  5. Evaluation of copper resistant bacteria from vineyard soils and mining waste for copper biosorption.

    Science.gov (United States)

    Andreazza, R; Pieniz, S; Okeke, B C; Camargo, F A O

    2011-01-01

    Vineyard soils are frequently polluted with high concentrations of copper due application of copper sulfate in order to control fungal diseases. Bioremediation is an efficient process for the treatment of contaminated sites. Efficient copper sorption bacteria can be used for bioremoval of copper from contaminated sites. In this study, a total of 106 copper resistant bacteria were examined for resistance to copper toxicity and biosorption of copper. Eighty isolates (45 from vineyard Mollisol, 35 from Inceptisol) were obtained from EMBRAPA (Empresa Brasileira de Pesquisa Agropecuária) experimental station, Bento Gonçalves, RS, Brazil (29°09'53.92″S and 51°31'39.40″W) and 26 were obtained from copper mining waste from Caçapava do Sul, RS, Brazil (30°29'43.48″S and 53'32'37.87W). Based on resistance to copper toxicity and biosorption, 15 isolates were identified by 16S rRNA gene sequencing. Maximal copper resistance and biosorption at high copper concentration were observed with isolate N2 which removed 80 mg L(-1) in 24 h. Contrarily isolate N11 (Bacillus pumilus) displayed the highest specific copper biosorption (121.82 mg/L/OD unit in 24 h). GenBank MEGABLAST analysis revealed that isolate N2 is 99% similar to Staphylococcus pasteuri. Results indicate that several of our isolates have potential use for bioremediation treatment of vineyards soils and mining waste contaminated with high copper concentration.

  6. Study on copper adsorption on olivine

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The copper adsorption on olivine supplied by A/S Olivine production plant at Aheim in western Norway has been studied. The factors which affect the uptake of copper have been evaluated. The results reveal that the equilibrium pH in aqueous solution has the greatest influence on the copper adsorption thanks to the competitive adsorption between proton and copper ions, and the adsorption of copper to olivine increases rapidly with the pH increasing from 4 to 6. The initial copper concentration and olivine dose also possess significant effect on copper adsorption. The adsorption efficieny of copper increases with the increase of olivine dose or the decrease of initial copper concentration at the same pH. The ionic strength effect on the adsorption has also been investigated, but it owns little effect on the adsorption process of copper due to the formation of inner sphere surface complexation of copper on olivine. The experimental data show that olivine has a high acid buffer capacity and is an effective adsorbent for copper.

  7. Copper metabolism in analbuminaemic rats fed a high-copper diet.

    NARCIS (Netherlands)

    Yu, S.; Berg, van den G.J.; Beynen, A.C.

    1995-01-01

    Copper metabolism in male Nagase analbuminaemic (NA) rats was compared with that in male Sprague Dawley (SD) rats fed purified diets containing either 5 or 100 mg Cu/kg diet. Dietary copper loading increased hepatic and kidney copper concentrations in both strains to the same extent, but baseline va

  8. Antarctic clouds

    OpenAIRE

    Lachlan-Cope, Tom

    2010-01-01

    Sensitivity studies with global climate models show that, by their influence on the radiation balance, Antarctic clouds play a major role in the climate system, both directly at high southern latitudes and indirectly globally, as the local circulation changes lead to global teleconnections. Unfortunately, observations of cloud distribution in the Antarctic are limited and often of low quality because of the practical difficulty in observing clouds in the harsh Antarctic environment. The best ...

  9. Energy and materials flows in the copper industry

    Energy Technology Data Exchange (ETDEWEB)

    Gaines, L.L.

    1980-12-01

    The copper industry comprises both the primary copper industry, which produces 99.9%-pure copper from copper ore, and the secondary copper industry, which salvages and recycles copper-containing scrap metal to extract pure copper or copper alloys. The United States uses about 2 million tons of copper annually, 60% of it for electrical applications. Demand is expected to increase less than 4% annually for the next 20 years. The primary copper industry is concentrated in the Southwest; Arizona produced 66% of the 1979 total ore output. Primary production uses about 170 x 10/sup 12/ Btu total energy annually (about 100 x 10/sup 6/ Btu/ton pure copper produced from ore). Mining and milling use about 60% of the total consumption, because low-grade ore (0.6% copper) is now being mined. Most copper is extracted by smelting sulfide ores, with concomitant production of sulfur dioxide. Clean air regulations will require smelters to reduce sulfur emissions, necessitating smelting process modifications that could also save 20 x 10/sup 12/ Btu (10 x 10/sup 6/ Btu/ton of copper) in smelting energy. Energy use in secondary copper production averages 20 x 10/sup 6/ Btu/ton of copper. If all copper products were recycled, instead of the 30% now salvaged, the energy conservation potential would be about one-half the total energy consumption of the primary copper industry.

  10. Energy and materials flows in the copper industry

    Energy Technology Data Exchange (ETDEWEB)

    Gaines, L.L.

    1980-12-01

    The copper industry comprises both the primary copper industry, which produces 99.9%-pure copper from copper ore, and the secondary copper industry, which salvages and recycles copper-containing scrap metal to extract pure copper or copper alloys. The United States uses about 2 million tons of copper annually, 60% of it for electrical applications. Demand is expected to increase less than 4% annually for the next 20 years. The primary copper industry is concentrated in the Southwest; Arizona produced 66% of the 1979 total ore output. Primary production uses about 170 x 10/sup 12/ Btu total energy annually (about 100 x 10/sup 6/ Btu/ton pure copper produced from ore). Mining and milling use about 60% of the total consumption, because low-grade ore (0.6% copper) is now being mined. Most copper is extracted by smelting sulfide ores, with concomitant production of sulfur dioxide. Clean air regulations will require smelters to reduce sulfur emissions, necessitating smelting process modifications that could also save 20 x 10/sup 12/ Btu (10 x 10/sup 6/ Btu/ton of copper) in smelting energy. Energy use in secondary copper production averages 20 x 10/sup 6/ Btu/ton of copper. If all copper products were recycled, instead of the 30% now salvaged, the energy conservation potential would be about one-half the total energy consumption of the primary copper industry.

  11. Copper toxicity in a New Zealand dairy herd.

    Science.gov (United States)

    Johnston, Howard; Beasley, Laura; MacPherson, Neil

    2014-01-01

    Chronic copper toxicity was diagnosed in a Jersey herd in the Waikato region of New Zealand following an investigation into the deaths of six cattle from a herd of 250 dry cows. Clinical signs and post-mortem examination results were consistent with a hepatopathy, and high concentrations of copper in liver and blood samples of clinically affected animals confirmed copper toxicity. Liver copper concentrations and serum gamma-glutamyl transferase activities were both raised in a group of healthy animals sampled at random from the affected herd, indicating an ongoing risk to the remaining cattle; these animals all had serum copper concentrations within normal limits. Serum samples and liver biopsies were also collected and assayed for copper from animals within two other dairy herds on the same farm; combined results from all three herds showed poor correlation between serum and liver copper concentrations. To reduce liver copper concentrations the affected herd was drenched with 0.5 g ammonium molybdate and 1 g sodium sulphate per cow for five days, and the herd was given no supplementary feed or mineral supplements. Liver biopsies were repeated 44 days after the initial biopsies (approximately 1 month after the end of the drenching program); these showed a significant 37.3% decrease in liver copper concentrations (P record keeping, but multiple sources of copper contributed to a long term copper over supplementation of the herd; the biggest source of copper was a mineral supplement. The farmer perceived this herd to have problems with copper deficiency prior to the diagnosis of copper toxicity, so this case demonstrates the importance of monitoring herd copper status regularly. Also the poor correlation between liver and serum copper concentrations in the three herds sampled demonstrates the importance of using liver copper concentration to assess herd copper status.

  12. Cloud Computing

    CERN Document Server

    Antonopoulos, Nick

    2010-01-01

    Cloud computing has recently emerged as a subject of substantial industrial and academic interest, though its meaning and scope is hotly debated. For some researchers, clouds are a natural evolution towards the full commercialisation of grid systems, while others dismiss the term as a mere re-branding of existing pay-per-use technologies. From either perspective, 'cloud' is now the label of choice for accountable pay-per-use access to third party applications and computational resources on a massive scale. Clouds support patterns of less predictable resource use for applications and services a

  13. Managing Clouds in Cloud Platforms

    CERN Document Server

    Ahmat, Kamal A

    2010-01-01

    Managing cloud services is a fundamental challenge in todays virtualized environments. These challenges equally face both providers and consumers of cloud services. The issue becomes even more challenging in virtualized environments that support mobile clouds. Cloud computing platforms such as Amazon EC2 provide customers with flexible, on demand resources at low cost. However, they fail to provide seamless infrastructure management and monitoring capabilities that many customers may need. For instance, Amazon EC2 doesn't fully support cloud services automated discovery and it requires a private set of authentication credentials. Salesforce.com, on the other hand, do not provide monitoring access to their underlying systems. Moreover, these systems fail to provide infrastructure monitoring of heterogenous and legacy systems that don't support agents. In this work, we explore how to build a cloud management system that combines heterogeneous management of virtual resources with comprehensive management of phys...

  14. Aerosol and Cloud Microphysical Characteristics of Rifts and Gradients in Maritime Stratocumulus Clouds

    Science.gov (United States)

    Sharon, Tarah M.; Albrecht, Bruce A.; Jonsson, Haflidi H.; Minnis, Patrick; Khaiyer, Mandana M.; Van Reken, Timothy; Seinfeld, John; Flagan, Rick

    2008-01-01

    A cloud rift is characterized as a large-scale, persistent area of broken, low reflectivity stratocumulus clouds usually surrounded by a solid deck of stratocumulus. A rift observed off the coast of Monterey Bay, California on 16 July 1999 was studied to compare the aerosol and cloud microphysical properties in the rift with those of the surrounding solid stratus deck. Variables measured from an instrumented aircraft included temperature, water vapor, and cloud liquid water. These measurements characterized the thermodynamic properties of the solid deck and rift areas. Microphysical measurements made included aerosol, cloud drop and drizzle drop concentrations and cloud condensation nuclei (CCN) concentrations. The microphysical characteristics in a solid stratus deck differ substantially from those of a broken, cellular rift where cloud droplet concentrations are a factor of 2 lower than those in the solid cloud. Further, CCN concentrations were found to be about 3 times greater in the solid cloud area compared with those in the rift and aerosol concentrations showed a similar difference as well. Although drizzle was observed near cloud top in parts of the solid stratus cloud, the largest drizzle rates were associated with the broken clouds within the rift area. In addition to marked differences in particle concentrations, evidence of a mesoscale circulation near the solid cloud rift boundary is presented. This mesoscale circulation provides a mechanism for maintaining a rift, but further study is required to understand the initiation of a rift and the conditions that may cause it to fill.

  15. Large Eddy Simulation Study on Arctic Marine Clouds: the Effect of Aerosol-Cloud Interactions

    Science.gov (United States)

    Raatikainen, T.; Ahola, J.; Tonttila, J.; Romakkaniemi, S.; Laaksonen, A.; Korhonen, H.

    2016-12-01

    Dynamics of marine stratocumulus clouds depend on radiative cooling from cloud tops, turbulent transport of moisture and heat from the sea surface, and the availability of atmospheric aerosols to act as cloud condensation nuclei (CCN). These processes and especially aerosol-cloud interactions can be examined with a recently developed Large Eddy Simulation (LES) model UCLALES-SALSA (Tonttila et al., Geosci. Model Dev. Discuss., 2016). Unlike most other LES models, UCLALES-SALSA has fully interactive sectional description for aerosols and liquid and frozen cloud species. UCLALES-SALSA simulations are initialized using atmospheric observations from the Arctic Summer Cloud Ocean Study (ASCOS). First, the model is used to examine the effects of initial total aerosol number concentration on cloud properties. In agreement with several observations, lowering aerosol number concentration decreases cloud lifetime by increasing drizzle and precipitation rates, which further decreases aerosol number concentration. The second test includes comparison between model versions with different microphysics. The new sectional approach seems to produce thicker and more persistent clouds than a two moment model version (Stevens et al., J. Atmos. Sci., 1999) even when the models are tuned to have equal cloud droplet number concentrations. The third part of the study is focused on the effect of ice on cloud properties. Preliminary results indicate that the current cloud case is so warm that the liquid phase dominates, but further studies are ongoing. In general, the results show that cloud evolution depends on aerosol-cloud interactions.

  16. Cloud Control

    Science.gov (United States)

    Ramaswami, Rama; Raths, David; Schaffhauser, Dian; Skelly, Jennifer

    2011-01-01

    For many IT shops, the cloud offers an opportunity not only to improve operations but also to align themselves more closely with their schools' strategic goals. The cloud is not a plug-and-play proposition, however--it is a complex, evolving landscape that demands one's full attention. Security, privacy, contracts, and contingency planning are all…

  17. Cloud Cover

    Science.gov (United States)

    Schaffhauser, Dian

    2012-01-01

    This article features a major statewide initiative in North Carolina that is showing how a consortium model can minimize risks for districts and help them exploit the advantages of cloud computing. Edgecombe County Public Schools in Tarboro, North Carolina, intends to exploit a major cloud initiative being refined in the state and involving every…

  18. Cloud Computing

    CERN Document Server

    Mirashe, Shivaji P

    2010-01-01

    Computing as you know it is about to change, your applications and documents are going to move from the desktop into the cloud. I'm talking about cloud computing, where applications and files are hosted on a "cloud" consisting of thousands of computers and servers, all linked together and accessible via the Internet. With cloud computing, everything you do is now web based instead of being desktop based. You can access all your programs and documents from any computer that's connected to the Internet. How will cloud computing change the way you work? For one thing, you're no longer tied to a single computer. You can take your work anywhere because it's always accessible via the web. In addition, cloud computing facilitates group collaboration, as all group members can access the same programs and documents from wherever they happen to be located. Cloud computing might sound far-fetched, but chances are you're already using some cloud applications. If you're using a web-based email program, such as Gmail or Ho...

  19. 干矿回旋筛在铜精矿筛分过程的故障及处理%The Failure and its Treatment of Dry Ore Rotary Screen in Screening Copper Concentrate

    Institute of Scientific and Technical Information of China (English)

    高坤

    2016-01-01

    With the continuous development of industrial technology, impurities screening degree of copper concentrate becomes higher and higher. Taking copper concentrate as the screening material,the problems existed in the application of 220T steam drying system in the smelting workshop of Guixi smelter are analyzed.From the point of view of equipment management, we should analyze the cause of failure, put forward the improvement measures, summarize the effect after the implementationand promote it.%随着工业化技术的不断发展,对铜精矿中杂质筛分程度越来越高。以铜精矿为筛分介质,分析了贵溪冶炼厂熔炼车间220T蒸汽干燥系统回旋筛应用过程中存在的问题。从设备管理角度出发,分析故障原因并提出改进措施,总结实施后的效果,并加以推广。

  20. Impacts of aerosol particles on the microphysical and radiative properties of stratocumulus clouds over the Southeast Pacific ocean

    Directory of Open Access Journals (Sweden)

    C. H. Twohy

    2012-08-01

    Full Text Available The Southeast Pacific Ocean is covered by the world's largest stratocumulus cloud layer, which has a strong impact on ocean temperatures and climate in the region. The effect of anthropogenic sources of aerosol particles such as power plants, urban pollution and smelters on the stratocumulus deck was investigated during the VOCALS field experiment. Aerosol measurements below and above cloud were made with a ultra-high sensitivity aerosol spectrometer and analytical electron microscopy. In addition to more standard in-cloud measurements, droplets were collected and evaporated using a counterflow virtual impactor (CVI, and the non-volatile residual particles were analyzed.

    Many flights focused on the gradient in cloud properties on an E-W track along 20° S from near the Chilean coast to remote areas offshore. Mean statistics from seven flights and many individual legs were compiled. Consistent with a continental source of cloud condensation nuclei, below-cloud accumulation-mode aerosol and droplet number concentration generally decreased from near shore to offshore. Single particle analysis was used to reveal types and sources of the enhanced particle number. While a variety of particle types were found throughout the region, the dominant particles near shore were partially neutralized sulfates. Modeling and chemical analysis indicated that the predominant source of these particles in the marine boundary layer along 20° S was anthropogenic pollution from central Chilean sources, with copper smelters a relatively small contribution.

    Cloud droplets were more numerous and smaller near shore, and there was less drizzle. Higher droplet number concentration and physically thinner clouds both contributed to the smaller droplets near shore. Satellite measurements were used to show that cloud albedo was highest 500–1000 km offshore, and actually lower closer to shore due to the generally thinner clouds and lower liquid water paths

  1. Produção de rúcula em hidroponia com diferentes concentrações de cobre Yield of roquette in hydroponic system, with different copper concentrations in the nutrient solution

    Directory of Open Access Journals (Sweden)

    Leilson C. Grangeiro

    2003-03-01

    Full Text Available O trabalho foi conduzido em casa de vegetação, da UNESP em Jaboticabal, de maio a junho de 2001, com o objetivo de avaliar o desempenho da rúcula, cultivar Cultivada, sob diferentes concentrações de cobre na solução nutritiva, em cultivo hidropônico. O delineamento utilizado foi inteiramente casualizado com quatro repetições e quatro tratamentos: 0; 0,036; 0,072 e 0,108 mgL-1 de Cu adicionado à solução nutritiva, na forma de sulfato de cobre. Após 30 dias do transplantio, 150 plantas foram colhidas ao acaso em cada parcela, para análise da matéria seca e dos teores de Cu, Fe, Zn e Mn na parte aérea das plantas. Foi observado sintoma visual de deficiência de Cu apenas no tratamento sem adição de cobre, com forte redução no tamanho das plantas. A produção de matéria seca da parte aérea foi significativamente influenciada pelo aumento das concentrações de Cu. A máxima produção e 95% da máxima foram obtidas, respectivamente, com 0,108 mgL-1 e 0,064 mgL-1 de cobre. Os teores de Cu e Mn na parte aérea aumentaram com as concentrações de Cu na solução nutritiva.The response of roquette cv. Cultivada, to different copper concentrations in the nutrient solution was evaluated. The experimental design was completely randomized, with four treatments (0; 0.036; 0.072 and 0.108 mgL-1 of copper added to the nutrient solution and four replications. 30 days after transplanting, 150 plants were collected at random in order to analyse the concentrations of Cu, Fe, Zn and Mn in the dry matter of the aerial part. Symptoms of deficiency were observed in the treatment without copper, presenting strong reduction in the plant size. The dry matter yield was significantly influenced by the increasing concentrations of Cu, with maximum production and 95% of maximum yield was obtained respectively with 0.108 and 0.064 mgL-1 of Cu in the nutritive solution. The concentration of Cu and Mn in the aerial part increased with increasing

  2. Marine Cloud Brightening

    Energy Technology Data Exchange (ETDEWEB)

    Latham, John; Bower, Keith; Choularton, Tom; Coe, H.; Connolly, P.; Cooper, Gary; Craft, Tim; Foster, Jack; Gadian, Alan; Galbraith, Lee; Iacovides, Hector; Johnston, David; Launder, Brian; Leslie, Brian; Meyer, John; Neukermans, Armand; Ormond, Bob; Parkes, Ben; Rasch, Philip J.; Rush, John; Salter, Stephen; Stevenson, Tom; Wang, Hailong; Wang, Qin; Wood, Robert

    2012-09-07

    The idea behind the marine cloud-brightening (MCB) geoengineering technique is that seeding marine stratocumulus clouds with copious quantities of roughly monodisperse sub-micrometre sea water particles might significantly enhance the cloud droplet number concentration, and thereby the cloud albedo and possibly longevity. This would produce a cooling, which general circulation model (GCM) computations suggest could - subject to satisfactory resolution of technical and scientific problems identified herein - have the capacity to balance global warming up to the carbon dioxide-doubling point. We describe herein an account of our recent research on a number of critical issues associated with MCB. This involves (i) GCM studies, which are our primary tools for evaluating globally the effectiveness of MCB, and assessing its climate impacts on rainfall amounts and distribution, and also polar sea-ice cover and thickness; (ii) high-resolution modelling of the effects of seeding on marine stratocumulus, which are required to understand the complex array of interacting processes involved in cloud brightening; (iii) microphysical modelling sensitivity studies, examining the influence of seeding amount, seedparticle salt-mass, air-mass characteristics, updraught speed and other parameters on cloud-albedo change; (iv) sea water spray-production techniques; (v) computational fluid dynamics studies of possible large-scale periodicities in Flettner rotors; and (vi) the planning of a three-stage limited-area field research experiment, with the primary objectives of technology testing and determining to what extent, if any, cloud albedo might be enhanced by seeding marine stratocumulus clouds on a spatial scale of around 100 km. We stress that there would be no justification for deployment of MCB unless it was clearly established that no significant adverse consequences would result. There would also need to be an international agreement firmly in favour of such action.

  3. Marine cloud brightening.

    Science.gov (United States)

    Latham, John; Bower, Keith; Choularton, Tom; Coe, Hugh; Connolly, Paul; Cooper, Gary; Craft, Tim; Foster, Jack; Gadian, Alan; Galbraith, Lee; Iacovides, Hector; Johnston, David; Launder, Brian; Leslie, Brian; Meyer, John; Neukermans, Armand; Ormond, Bob; Parkes, Ben; Rasch, Phillip; Rush, John; Salter, Stephen; Stevenson, Tom; Wang, Hailong; Wang, Qin; Wood, Rob

    2012-09-13

    The idea behind the marine cloud-brightening (MCB) geoengineering technique is that seeding marine stratocumulus clouds with copious quantities of roughly monodisperse sub-micrometre sea water particles might significantly enhance the cloud droplet number concentration, and thereby the cloud albedo and possibly longevity. This would produce a cooling, which general circulation model (GCM) computations suggest could-subject to satisfactory resolution of technical and scientific problems identified herein-have the capacity to balance global warming up to the carbon dioxide-doubling point. We describe herein an account of our recent research on a number of critical issues associated with MCB. This involves (i) GCM studies, which are our primary tools for evaluating globally the effectiveness of MCB, and assessing its climate impacts on rainfall amounts and distribution, and also polar sea-ice cover and thickness; (ii) high-resolution modelling of the effects of seeding on marine stratocumulus, which are required to understand the complex array of interacting processes involved in cloud brightening; (iii) microphysical modelling sensitivity studies, examining the influence of seeding amount, seed-particle salt-mass, air-mass characteristics, updraught speed and other parameters on cloud-albedo change; (iv) sea water spray-production techniques; (v) computational fluid dynamics studies of possible large-scale periodicities in Flettner rotors; and (vi) the planning of a three-stage limited-area field research experiment, with the primary objectives of technology testing and determining to what extent, if any, cloud albedo might be enhanced by seeding marine stratocumulus clouds on a spatial scale of around 100×100 km. We stress that there would be no justification for deployment of MCB unless it was clearly established that no significant adverse consequences would result. There would also need to be an international agreement firmly in favour of such action.

  4. Screaming Clouds

    Science.gov (United States)

    Fikke, Svein; Egill Kristjánsson, Jón; Nordli, Øyvind

    2017-04-01

    "Mother-of-pearl clouds" appear irregularly in the winter stratosphere at high northern latitudes, about 20-30 km above the surface of the Earth. The size range of the cloud particles is near that of visible light, which explains their extraordinary beautiful colours. We argue that the Norwegian painter Edvard Munch could well have been terrified when the sky all of a sudden turned "bloodish red" after sunset, when darkness was expected. Hence, there is a high probability that it was an event of mother-of-pearl clouds which was the background for Munch's experience in nature, and for his iconic Scream. Currently, the leading hypothesis for explaining the dramatic colours of the sky in Munch's famous painting is that the artist was captivated by colourful sunsets following the enormous Krakatoa eruption in 1883. After carefully considering the historical accounts of some of Munch's contemporaries, especially the physicist Carl Störmer, we suggest an alternative hypothesis, namely that Munch was inspired by spectacular occurrences of mother-of-pearl clouds. Such clouds, which have a wave-like structure akin to that seen in the Scream were first observed and described only a few years before the first version of this motive was released in 1892. Unlike clouds related to conventional weather systems in the troposphere, mother-of-pearl clouds appear in the stratosphere, where significantly different physical conditions prevail. This result in droplet sizes within the range of visible light, creating the spectacular colour patterns these clouds are famous for. Carl Störmer observed such clouds, and described them in minute details at the age of 16, but already with a profound interest in science. He later noted that "..these mother-of-pearl clouds was a vision of indescribable beauty!" The authors find it logical that the same vision could appear scaring in the sensible mind of a young artist unknown to such phenomena.

  5. Insight into selective removal of copper from high-concentration nickel solutions with XPS and DFT: New technique to prepare 5N-nickel with chelating resin.

    Science.gov (United States)

    Tao, Xuewen; Liu, Fuqiang; Bai, Zhiping; Wei, Dongyang; Zhang, Xiaopeng; Wang, Junfei; Gao, Jie; Sun, Xiaowen; Li, Baohua; Li, Chenghui; Li, Aimin

    2016-10-01

    An efficient and profitable separation process was proposed to prepare 5N (the purity of the metal solution reaches 99.999%) high-purity nickel from 3N nickel-solutions using Purolite S984. The adsorption performance of this superior resin, especially its selectivity for metal ions, was explored quantitatively. The maximum adsorption capacity for copper was 2.286mmol/g calculated by the Langmuir model, which was twice as large as that for nickel. In the binary systems, the adsorption capacity for nickel was decreased by 45%, indicating direct competition for the active sites. The infinite separation factor for copper versus nickel exceeded 300, revealing the feasibility of preparing 5N-level high-purity nickel solutions, which was further verified using the 800BV (bed volume) effluent in the column dynamic process. According to the cost-benefit analysis, purification contributed to a profit of approximately 60,000USD per cycle, and the investment return period was less than 1/3years. Density functional theory analysis confirmed that four nitrogen atoms would be involved in the coordination complex and thus a structure involving two five-membered rings could be achieved. The X-ray photoelectron spectra confirmed the involvement of nitrogen atoms, implying a coordination ratio of approximately 1:1.

  6. Contrasting cloud composition between coupled and decoupled marine boundary layer clouds

    Science.gov (United States)

    Wang, Zhen; Mora Ramirez, Marco; Dadashazar, Hossein; MacDonald, Alex B.; Crosbie, Ewan; Bates, Kelvin H.; Coggon, Matthew M.; Craven, Jill S.; Lynch, Peng; Campbell, James R.; Azadi Aghdam, Mojtaba; Woods, Roy K.; Jonsson, Haflidi; Flagan, Richard C.; Seinfeld, John H.; Sorooshian, Armin

    2016-10-01

    Marine stratocumulus clouds often become decoupled from the vertical layer immediately above the ocean surface. This study contrasts cloud chemical composition between coupled and decoupled marine stratocumulus clouds for dissolved nonwater substances. Cloud water and droplet residual particle composition were measured in clouds off the California coast during three airborne experiments in July-August of separate years (Eastern Pacific Emitted Aerosol Cloud Experiment 2011, Nucleation in California Experiment 2013, and Biological and Oceanic Atmospheric Study 2015). Decoupled clouds exhibited significantly lower air-equivalent mass concentrations in both cloud water and droplet residual particles, consistent with reduced cloud droplet number concentration and subcloud aerosol (Dp > 100 nm) number concentration, owing to detachment from surface sources. Nonrefractory submicrometer aerosol measurements show that coupled clouds exhibit higher sulfate mass fractions in droplet residual particles, owing to more abundant precursor emissions from the ocean and ships. Consequently, decoupled clouds exhibited higher mass fractions of organics, nitrate, and ammonium in droplet residual particles, owing to effects of long-range transport from more distant sources. Sodium and chloride dominated in terms of air-equivalent concentration in cloud water for coupled clouds, and their mass fractions and concentrations exceeded those in decoupled clouds. Conversely, with the exception of sea-salt constituents (e.g., Cl, Na, Mg, and K), cloud water mass fractions of all species examined were higher in decoupled clouds relative to coupled clouds. Satellite and Navy Aerosol Analysis and Prediction System-based reanalysis data are compared with each other, and the airborne data to conclude that limitations in resolving boundary layer processes in a global model prevent it from accurately quantifying observed differences between coupled and decoupled cloud composition.

  7. Concentrations of strontium, barium, cadmium, copper, zinc, manganese, chromium, antimony, selenium, and lead in the liver and kidneys of dogs according to age, gender, and the occurrence of chronic kidney disease.

    Science.gov (United States)

    Passlack, Nadine; Mainzer, Barbara; Lahrssen-Wiederholt, Monika; Schafft, Helmut; Palavinskas, Richard; Breithaupt, Angele; Zentek, Jürgen

    2015-01-01

    This study was conducted to measure the concentrations of strontium (Sr), barium (Ba), cadmium (Cd), copper (Cu), zinc (Zn), manganese (Mn), chromium (Cr), antimony (Sb), selenium (Se), and lead (Pb) in canine liver, renal cortex, and renal medulla, and the association of these concentrations with age, gender, and occurrence of chronic kidney disease (CKD). Tissues from 50 dogs were analyzed using inductively coupled plasma mass spectrometry. Cu, Zn, and Mn levels were highest in the liver followed by the renal cortex and renal medulla. The highest Sr, Cd, and Se concentrations were measured in the renal cortex while lower levels were found in the renal medulla and liver. Female dogs had higher tissue concentrations of Sr (liver and renal medulla), Cd (liver), Zn (liver and renal cortex), Cr (liver, renal cortex, and renal medulla), and Pb (liver) than male animals. Except for Mn and Sb, age-dependent variations were observed for all element concentrations in the canine tissues. Hepatic Cd and Cr concentrations were higher in dogs with CKD. In conclusion, the present results provide new knowledge about the storage of specific elements in canine liver and kidneys, and can be considered important reference data for diagnostic methods and further investigations.

  8. Securing Cloud from Cloud Drain

    Directory of Open Access Journals (Sweden)

    Niva Das

    2014-09-01

    Full Text Available Today, in the world of communication, connected systems is growing at a rapid pace. To accommodate this growth the need for computational power and storage is also increasing at a similar rate. Companies are investing a large amount of resources in buying, maintaining and ensuring availability of the system to their customers. To mitigate these issues, cloud computing is playing a major role [1]. The underlying concept of cloud computing dates back to the ‘50s but the term entering into widespread usage can be traced to 2006 when Amazon.com announced the Elastic Compute Cloud. In this paper, we will discuss about cloud security approaches. We have used the term “CloudDrain” to define data leakage in case of security compromise.

  9. Cloud migration

    CERN Document Server

    Höllwarth, Tobias

    2012-01-01

    This book is designed for managers and entrepreneurs, who are considering improving the economics and flexibility of their IT solutions and infrastructures. The book is also for readers who wish to learn more about the Cloud, but do not want to become specialists.This book discusses the technical, legal, fiscal, economic, organisational and environmental aspects of Cloud services. If you are looking for practical advice on vendor selection and certification, as well as real world Cloud project case studies, this is the book to consult.It is the result of a highly cooper

  10. Cloud Computing

    CERN Document Server

    Baun, Christian; Nimis, Jens; Tai, Stefan

    2011-01-01

    Cloud computing is a buzz-word in today's information technology (IT) that nobody can escape. But what is really behind it? There are many interpretations of this term, but no standardized or even uniform definition. Instead, as a result of the multi-faceted viewpoints and the diverse interests expressed by the various stakeholders, cloud computing is perceived as a rather fuzzy concept. With this book, the authors deliver an overview of cloud computing architecture, services, and applications. Their aim is to bring readers up to date on this technology and thus to provide a common basis for d

  11. The Effective Electrolytic Recovery of Dilute Copper from Industrial Wastewater

    Directory of Open Access Journals (Sweden)

    Teng-Chien Chen

    2013-01-01

    Full Text Available Electroplating copper industry was discharged huge amount wastewater and cause serious environmental and health damage in Taiwan. This research applied electrical copper recovery system to recover copper metal. In this work, electrotreatment of a industrial copper wastewater ([Cu] = 30000 mg L−1 was studied with titanium net coated with a thin layer of RuO2/IrO2 (DSA reactor. The optimal result for simulated copper solution was 99.9% copper recovery efficiency in current density 0.585 A/dm2 and no iron ion. Due to high concentration of iron and chloride ions in real industrial wastewater, the copper recovery efficiency was down to 60%. Although, the copper recovery efficiency was not high as simulated copper solution, high environmental economic value was included in the technology. The possibility of pretreating the wastewater with iron is the necessary step, before the electrical recovery copper system.

  12. Removal of copper from copper-contaminated river water and aqueous solutions using Methylobacterium extorquens modified Erzurum clayey soil

    National Research Council Canada - National Science Library

    Neslihan Celebi; Hayrunnisa Nadaroglu; Ekrem Kalkan; Recep Kotan

    2016-01-01

    ... adsorbent materials for the removal of copper from aqueous solution. The copper concentrations in the samples of the polluted river water and CuCl solutions treated by the natural and bacteria-modified Erzurum clayey soil (ECS...

  13. Processes Affecting Phosphorus and Copper Concentrations and Their Relation to Algal Growth in Two Supply Reservoirs in the Lower Coastal Plain of Virginia, 2002-2003, and Implications for Alternative Management Strategies

    Science.gov (United States)

    Speiran, Gary K.; Simon, Nancy S.; Mood-Brown, Maria L.

    2007-01-01

    Elevated phosphorus concentrations commonly promote excessive growth of algae in waters nationwide. When such waters are used for public supply, the algae can plug filters during treatment and impart tastes and odors to the finished water. This increases treatment costs and results in finished water that may not be of the quality desired for public supply. Consequently, copper sulfate is routinely applied to many reservoirs to control algal growth but only is a 'temporary fix' and must be reapplied at intervals that can range from more than 30 days in the winter to less than 7 days in the summer. Because copper has a maximum allowable concentration in public drinking water and can be toxic to aquatic life, water suppliers commonly seek to develop alternative, long-term strategies for managing reservoirs. Because these are nationwide issues and part of the mission of the U.S. Geological Survey (USGS) is to define and protect the quality of the Nation's water resources and better understand the physical, chemical, and biological processes in wetlands, lakes, reservoirs, and estuaries, investigations into these issues are important to the fulfillment of the mission of the USGS. The City of Newport News, Virginia, provides 50 million gallons per day of treated water for public supply from Lee Hall and Harwoods Mill Reservoirs (terminal reservoirs) to communities on the lower York-James Peninsula. About 3,500 pounds of copper sulfate are applied to each reservoir at 3- to 99-day intervals to control algal growth. Consequently, the USGS, in cooperation with the City of Newport News, investigated the effects of management practices and natural processes on phosphorus (the apparent growth-limiting nutrient), copper, and algal concentrations in the terminal reservoirs to provide information that can be used to develop alternative management strategies for the terminal reservoirs. Initial parts of the research evaluated circulation and stratification in the reservoirs

  14. 某含铜金精矿热压预氧化脱铜-氰化浸金试验研究%Experimental Study on Removal of Copper by Preoxidation and Leaching of Gold by Cyanidation From Copper-bearing Gold Concentrate

    Institute of Scientific and Technical Information of China (English)

    蔡创开

    2013-01-01

    A gold concentrate containing copper is refractory .Most of gold exists in the form of submic roscopic gold .Conventional cyanidation leaching rate of gold in the concentrate is lower than 20% . Removal of copper by pressure oxidation at heating and leaching of gold by cyanidation was studied . The effects of temperature ,oxygen pressure ,the mass ratio between liquid and solid ,stirring speed and time on the removal rate of copper were examined .The results show that at the conditions of temperature of 210 ℃ ,oxygen pressure of 1 .1 MPa ,the mass ratio between liquid and solid of 5∶1 , stirring speed of 700 r/min and preoxidation time of 70 minutes ,the removal rate of copper is more than 98% .The oxidizing slag slurry’s pH is adjusted in the range of 10-11 using lime ,then to leach gold using sodium cyanide solutin of 1 g/L ,the leaching rate of gold is more than 98% .%某含铜金精矿难于处理,金呈亚显微形式存在。研究了采用热压预氧化法脱铜,氧化渣氰化浸出金,考察了温度、压力、矿浆浓度、搅拌强度和预氧化时间对氧化脱铜的影响。试验结果表明:在温度210℃、氧分压1.1 M Pa、液固质量比5∶1、搅拌强度700 r/min、预氧化时间70 min条件下,铜脱除率大于98%;氧化脱铜渣浆用石灰调pH为1011,用质量浓度为1 g/L的NaCN浸出金,金浸出率大于98%。

  15. Recovery of gold, silver and copper from complex gold concentrate by roasting-acidic leaching-cyanidation process%焙烧-酸浸-氰化法从复杂金精矿中回收金银铜

    Institute of Scientific and Technical Information of China (English)

    吴在玖

    2013-01-01

      采用焙烧-酸浸-氰化工艺综合回收复杂金精矿中的金、银、铜.结果表明,焙烧温度、焙烧时间、焙烧添加剂种类和用量对金、银、铜浸出率影响显著.实验确定了较优工艺条件为:焙烧添加剂NaOH用量为6%,温度630℃,焙烧时间3 h,硫酸浓度1 mol/L,酸浸液固体积质量比5∶1,酸浸温度50℃,酸浸4 h,氰化纳浓度3‰,氰化浸出液固体积质量比5∶1,常温氰化72 h.在上述条件下,金、银、铜浸出率分别达到93.53%、75.37%、94.23%.%Gold, silver and copper were extracted from complex gold concentrate by roasting-acidic leaching-cyanidation process. The experimental results show that the roasting temperature, time, additive and its dosage have great influence on the leaching of gold, silver and copper. The optimal conditions were further determined as follows: NaOH dosage of 6 %(ω), roasting temperature of 630 °C, roasting time of 3 h, sulfuric acid concentration of 1 mol/L, liquid to solid ratio of 5∶1 in acidic leach, leaching temperature of 50 °C, leaching time of 4 h, sodium cyanide concentration of 3 ‰, liquid to solid ratio of 5∶1 in cyanidation, room temperature and cyanidation time of 72 h. Under above-mentioned conditions, the leaching rate of gold, silver and copper achieved at 93.53%, 75.37%and 94.23%respectively.

  16. Cloud Formation

    Science.gov (United States)

    Graham, Mark Talmage

    2004-05-01

    Cloud formation is crucial to the heritage of modern physics, and there is a rich literature on this important topic. In 1927, Charles T.R. Wilson was awarded the Nobel Prize in physics for applications of the cloud chamber.2 Wilson was inspired to study cloud formation after working at a meteorological observatory on top of the highest mountain in Scotland, Ben Nevis, and testified near the end of his life, "The whole of my scientific work undoubtedly developed from the experiments I was led to make by what I saw during my fortnight on Ben Nevis in September 1894."3 To form clouds, Wilson used the sudden expansion of humid air.4 Any structure the cloud may have is spoiled by turbulence in the sudden expansion, but in 1912 Wilson got ion tracks to show up by using strobe photography of the chamber immediately upon expansion.5 In the interim, Millikan's study in 1909 of the formation of cloud droplets around individual ions was the first in which the electron charge was isolated. This study led to his famous oil drop experiment.6 To Millikan, as to Wilson, meteorology and physics were professionally indistinct. With his meteorological physics expertise, in WWI Millikan commanded perhaps the first meteorological observation and forecasting team essential to military operation in history.7 But even during peacetime meteorology is so much of a concern to everyone that a regular news segment is dedicated to it. Weather is the universal conversation topic, and life on land could not exist as we know it without clouds. One wonders then, why cloud formation is never covered in physics texts.

  17. Marine cloud brightening

    Science.gov (United States)

    Latham, John; Bower, Keith; Choularton, Tom; Coe, Hugh; Connolly, Paul; Cooper, Gary; Craft, Tim; Foster, Jack; Gadian, Alan; Galbraith, Lee; Iacovides, Hector; Johnston, David; Launder, Brian; Leslie, Brian; Meyer, John; Neukermans, Armand; Ormond, Bob; Parkes, Ben; Rasch, Phillip; Rush, John; Salter, Stephen; Stevenson, Tom; Wang, Hailong; Wang, Qin; Wood, Rob

    2012-01-01

    The idea behind the marine cloud-brightening (MCB) geoengineering technique is that seeding marine stratocumulus clouds with copious quantities of roughly monodisperse sub-micrometre sea water particles might significantly enhance the cloud droplet number concentration, and thereby the cloud albedo and possibly longevity. This would produce a cooling, which general circulation model (GCM) computations suggest could—subject to satisfactory resolution of technical and scientific problems identified herein—have the capacity to balance global warming up to the carbon dioxide-doubling point. We describe herein an account of our recent research on a number of critical issues associated with MCB. This involves (i) GCM studies, which are our primary tools for evaluating globally the effectiveness of MCB, and assessing its climate impacts on rainfall amounts and distribution, and also polar sea-ice cover and thickness; (ii) high-resolution modelling of the effects of seeding on marine stratocumulus, which are required to understand the complex array of interacting processes involved in cloud brightening; (iii) microphysical modelling sensitivity studies, examining the influence of seeding amount, seed-particle salt-mass, air-mass characteristics, updraught speed and other parameters on cloud–albedo change; (iv) sea water spray-production techniques; (v) computational fluid dynamics studies of possible large-scale periodicities in Flettner rotors; and (vi) the planning of a three-stage limited-area field research experiment, with the primary objectives of technology testing and determining to what extent, if any, cloud albedo might be enhanced by seeding marine stratocumulus clouds on a spatial scale of around 100×100 km. We stress that there would be no justification for deployment of MCB unless it was clearly established that no significant adverse consequences would result. There would also need to be an international agreement firmly in favour of such action

  18. Copper tolerance of a new strain of Penicillium ochro-chloron

    Energy Technology Data Exchange (ETDEWEB)

    Okamoto, K.; Fuwa, K.

    1974-01-01

    In this paper, the effect of external copper concentration on the growth and uptake of copper by Penicillium ochro-chloron is reported to elucidate the cause of its copper tolerance and to compare it to the tolerances of other species, Aspergillus niger, and Penicillium chrysogenum. In this organism, copper uptake is proportional to extend concentration only at lower concentrations, and levels of above 1000 ..mu..g/ml of copper on the medium.

  19. Different pathways for copper sulphate and copper nitrate antioxidation and organic acid excretion in Typha latifolia?

    OpenAIRE

    Lyubenova L.; Kuhn A.; Höltkemeier A.; Bipuah H.; Belford E.; Schröder P.

    2013-01-01

    The major topic of the present experiment was the investigation of the antioxidative enzymes and the root exudate excretion after plant exposure to copper. The copper was added for each treatment as copper sulphate and copper nitrate in the concentrations of 10 μM, 50 μM and 100 μM, respectively. The plant species chosen for the study was Typha latifolia. The experiment gives insight into the plant responses to different copper supplies during the same conditions of exposure. Remarkable resul...

  20. Ash cloud aviation advisories

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan, T.J.; Ellis, J.S. [Lawrence Livermore National Lab., CA (United States); Schalk, W.W.; Nasstrom, J.S. [EG and G, Inc., Pleasanton, CA (United States)

    1992-06-25

    During the recent (12--22 June 1991) Mount Pinatubo volcano eruptions, the US Air Force Global Weather Central (AFGWC) requested assistance of the US Department of Energy`s Atmospheric Release Advisory Capability (ARAC) in creating volcanic ash cloud aviation advisories for the region of the Philippine Islands. Through application of its three-dimensional material transport and diffusion models using AFGWC meteorological analysis and forecast wind fields ARAC developed extensive analysis and 12-hourly forecast ash cloud position advisories extending to 48 hours for a period of five days. The advisories consisted of ``relative`` ash cloud concentrations in ten layers (surface-5,000 feet, 5,000--10,000 feet and every 10,000 feet to 90,000 feet). The ash was represented as a log-normal size distribution of 10--200 {mu}m diameter solid particles. Size-dependent ``ashfall`` was simulated over time as the eruption clouds dispersed. Except for an internal experimental attempt to model one of the Mount Redoubt, Alaska, eruptions (12/89), ARAC had no prior experience in modeling volcanic eruption ash hazards. For the cataclysmic eruption of 15--16 June, the complex three-dimensional atmospheric structure of the region produced dramatically divergent ash cloud patterns. The large eruptions (> 7--10 km) produced ash plume clouds with strong westward transport over the South China Sea, Southeast Asia, India and beyond. The low-level eruptions (< 7 km) and quasi-steady-state venting produced a plume which generally dispersed to the north and east throughout the support period. Modeling the sequence of eruptions presented a unique challenge. Although the initial approach proved viable, further refinement is necessary and possible. A distinct need exists to quantify eruptions consistently such that ``relative`` ash concentrations relate to specific aviation hazard categories.

  1. Microphysics of Pyrocumulonimbus Clouds

    Science.gov (United States)

    Jensen, Eric; Ackerman, Andrew S.; Fridlind, Ann

    2004-01-01

    The intense heat from forest fires can generate explosive deep convective cloud systems that inject pollutants to high altitudes. Both satellite and high-altitude aircraft measurements have documented cases in which these pyrocumulonimbus clouds inject large amounts of smoke well into the stratosphere (Fromm and Servranckx 2003; Jost et al. 2004). This smoke can remain in the stratosphere, be transported large distances, and affect lower stratospheric chemistry. In addition recent in situ measurements in pyrocumulus updrafts have shown that the high concentrations of smoke particles have significant impacts on cloud microphysical properties. Very high droplet number densities result in delayed precipitation and may enhance lightning (Andrew et al. 2004). Presumably, the smoke particles will also lead to changes in the properties of anvil cirrus produces by the deep convection, with resulting influences on cloud radiative forcing. In situ sampling near the tops of mature pyrocumulonimbus is difficult due to the high altitude and violence of the storms. In this study, we use large eddy simulations (LES) with size-resolved microphysics to elucidate physical processes in pyrocumulonimbus clouds.

  2. Microphysics of Pyrocumulonimbus Clouds

    Science.gov (United States)

    Jensen, Eric; Ackerman, Andrew S.; Fridlind, Ann

    2004-01-01

    The intense heat from forest fires can generate explosive deep convective cloud systems that inject pollutants to high altitudes. Both satellite and high-altitude aircraft measurements have documented cases in which these pyrocumulonimbus clouds inject large amounts of smoke well into the stratosphere (Fromm and Servranckx 2003; Jost et al. 2004). This smoke can remain in the stratosphere, be transported large distances, and affect lower stratospheric chemistry. In addition recent in situ measurements in pyrocumulus updrafts have shown that the high concentrations of smoke particles have significant impacts on cloud microphysical properties. Very high droplet number densities result in delayed precipitation and may enhance lightning (Andrew et al. 2004). Presumably, the smoke particles will also lead to changes in the properties of anvil cirrus produces by the deep convection, with resulting influences on cloud radiative forcing. In situ sampling near the tops of mature pyrocumulonimbus is difficult due to the high altitude and violence of the storms. In this study, we use large eddy simulations (LES) with size-resolved microphysics to elucidate physical processes in pyrocumulonimbus clouds.

  3. The Serpens Molecular Cloud

    CERN Document Server

    Eiroa, C; Casali, M M

    2008-01-01

    The Serpens cloud has received considerable attention in the last years, in particular the small region known as the Serpens cloud core where a plethora of star formation related phenomena are found. This review summarizes our current observational knowledge of the cloud, with emphasis on the core. Recent results are converging to a distance for the cloud of ~ 230 +- 20 pc, an issue which has been controversial over the years. We present the gas and dust properties of the cloud core and describe its structure and appearance at different wavelengths. The core contains a dense, very young, low mass stellar cluster with more than 300 objects in all evolutionary phases, from collapsing gaseous condensations to pre-main sequence stars. We describe the behaviour and spatial distribution of the different stellar populations (mm cores, Classes 0, I and II sources). The spatial concentration and the fraction number of Class 0/Class I/Class II sources is considerably larger in the Serpens core than in any other low mas...

  4. Accumulation and hyperaccumulation of copper in plants

    Science.gov (United States)

    Adam, V.; Trnkova, L.; Huska, D.; Babula, P.; Kizek, R.

    2009-04-01

    Copper is natural component of our environment. Flow of copper(II) ions in the environment depends on solubility of compounds containing this metal. Mobile ion coming from soil and rocks due to volcanic activity, rains and others are then distributed to water. Bio-availability of copper is substantially lower than its concentration in the aquatic environment. Copper present in the water reacts with other compounds and creates a complex, not available for organisms. The availability of copper varies depending on the environment, but moving around within the range from 5 to 25 % of total copper. Thus copper is stored in the sediments and the rest is transported to the seas and oceans. It is common knowledge that copper is essential element for most living organisms. For this reason this element is actively accumulated in the tissues. The total quantity of copper in soil ranges from 2 to 250 mg / kg, the average concentration is 30 mg / kg. Certain activities related to agriculture (the use of fungicides), possibly with the metallurgical industry and mining, tend to increase the total quantity of copper in the soil. This amount of copper in the soil is a problem particularly for agricultural production of food. The lack of copper causes a decrease in revenue and reduction in quality of production. In Europe, shows the low level of copper in total 18 million hectares of farmland. To remedy this adverse situation is the increasing use of copper fertilizers in agricultural soils. It is known that copper compounds are used in plant protection against various illnesses and pests. Mining of minerals is for the development of human society a key economic activity. An important site where the copper is mined in the Slovakia is nearby Smolníka. Due to long time mining in his area (more than 700 years) there are places with extremely high concentrations of various metals including copper. Besides copper, there are also detected iron, zinc and arsenic. Various plant species

  5. Experimental study on comprehensive recovery of gold, silver, copper and sulphur from copper-bearing high-sulphur gold concentrate%某含铜高硫金精矿综合回收金、银、铜、硫试验研究

    Institute of Scientific and Technical Information of China (English)

    贾学国; 何辉; 刘振辉; 谢建宏; 张崇辉

    2012-01-01

    某金精矿中含金36.25g/t、铜2.37%,硫46.83%。为使其中的有价元素有效回收,在其工艺矿物学研究的基础上,分别进行了全浮流程试验和重-浮联合流程试验。通过大量的试验研究,最终确定采用重-浮联合流程试验,所得选矿指标为金、银、铜在重砂、铜精矿中的总回收率分别高达96.19%、87.91%、96.45%,硫回收率100%,使得资源得到很好的综合回收和利用。%A gold concentrate contained gold of 36.25 g/t, copper of 2.37% and sulphur of 46.83%. In order to effectively recover valuable elements, single flotation process and combination process of gravity concentra- tion and flotation were separately conducted. And then the combination process of gravity concentration and flotation was determined after lots of experimental study. The recovery rate of gold, silver and copper reached 96.19%, 87.91% and 96.45% in the concentrate, and sulphur recovery rate was 100%. The mineral resources were recovered and utilized well.

  6. Determination of mercury in copper concentrates by amalgam gathering-atomic absorption spectrometry%汞齐捕集-原子吸收光谱法测定铜精矿中汞含量

    Institute of Scientific and Technical Information of China (English)

    郭芬; 苏明跃; 谷松海

    2011-01-01

    It only took 5-6 min to determine powdered copper concentrate at 253. 7 nm by a direct mercury analyzer without the need of sample digestion. In order to reduce the damage of mercury in sample to the instrument and guarantee the accuracy of determination results, the sampling amount was 0. 15 g. Meanwhile, single determination mode was used to reduce the memory effect of sample boat.The detection [imit of this method was 0. 2 μg/kg. The content of mercury in three national certified reference materials of copper concentrate with different content ranges was determined. The results were consistent with those obtained by national standard method. The relative standard deviations (RSD) were smaller than or equal to 4. 7 %, and the recoveries were 98 %-102%.%无需进行样品消化处理,铜精矿粉末样品在253.7 nm处用直接测汞仪进行分析,5~6 min即可获取结果.为减少样品中汞对仪器的毒害同时保证测定结果的准确,样品取样量选择为0.15 g;同时,采用单个测定方式可减少样品舟存在的记忆效应.方法的检出限为0.2μg/kg.对3个不同含量范围铜精矿国家标准物质中的汞进行测定,结果同国标法的测定结果一致,相对标准偏差≤4.7%,回收率为98%~102%.

  7. 含铜难处理金精矿焙烧-酸浸-氰化提金工艺研究%Roasting-acid Leaching-cyanidation of Refractory Gold Concentrate Containing Copper

    Institute of Scientific and Technical Information of China (English)

    衷水平

    2013-01-01

    Focusing on refractory gold concentrate containing copper,the technology of roasting-acid leaching-cyanidation was studied and the optimized condition was obtained.Experimentation results show that Cu leaching rate is above 95% and copper grade of acid-leach residue is low of 0.3% when concentrate roasted 2 hours at temperature of 540 ℃,roasted product is leached with sulfuric acid of 30 g/L under conditions of 3 of liquid-solid ratio,90 ℃ of temperature and time of 1.5 hours.The recovery rate of Au is above 96% when decoppering slag is leached with the densities of sodium cyanide of 4‰under conditions of 30%of pulp density and time of 24 hours. This process realizes recovery Au and Cu in high efficiency.%  针对某含铜难处理金精矿,研究了焙烧—酸浸—氰化提金工艺,获得了优化工艺条件。结果表明,在焙烧温度为540℃,焙烧时间2 h,焙砂在初酸浓度为30 g/L、液固比3∶1,浸出温度90℃,浸出时间1.5 h的条件下,Cu浸出率>95%,酸浸渣铜品位可降至0.3%以下;脱铜渣在NaCN浓度为4‰、矿浆浓度为30%,氰化时间24 h的条件下,Au浸出率达96%以上,实现了Au和Cu的高效回收。

  8. 从高硫多金属金精矿中提取金银铜试验研究%Experimental study on extraction of gold,silver and copper from high-sulfur content and polymetallic gold concentrates

    Institute of Scientific and Technical Information of China (English)

    王瑞祥; 谢博毅; 刘建华; 张焕然

    2014-01-01

    采用焙烧-酸浸-氰化工艺从高硫多金属金精矿中提取金、银、铜。其试验结果表明:在最佳条件下,金、银、铜的平均浸出率分别可达到96.56%、79.12%、91.33%。通过对比金精矿、焙砂、氰化渣中金、银的化学物相可知,硅酸盐包裹金、银不易被氰化浸出,而加入复合添加剂焙烧,硅酸盐包裹的金、银品位大幅度下降,由直接焙烧的2.05 g/t、163.35 g/t分别降到0.81 g/t、25.24 g/t。%Gold ,silver and copper are extracted from high-sulfur content and polymetallic gold concentrates by roasting-acid leaching -cyanidation process .It is revealed that under optimal conditions the leaching rates of gold , silver and copper were respectively were 96.56%,79.12%and 91.33%.By comparing the chemical phase of gold and silver in gold concentrates ,calcines and cyanidation slags ,it is known that the gold and silver encapsulated in sili-cates are difficult to leach by cyanide ,but with composite additive in roasting ,the amount of gold and silver encapsula-ted in silicates is greatly reduced obviously ,from 2.05 g/t,163.35 g/t respectively to 0.18 g/t,25.24 g/t.

  9. 原子吸收光谱法连续测定金精矿中的银铜铅锌%Continuous determination of silver,copper,lead and zinc in gold concentrates by atomic absorption spectrometry

    Institute of Scientific and Technical Information of China (English)

    孔令强; 李伟彦; 邵国强

    2016-01-01

    Separate determination of silver,copper,lead and zinc in gold concentrates in daily testing wastes time and labor. So AAS was used to continuously determine silver,copper,lead and zinc in single-time sample dissolution. Gold concentrates were dissolved by mixed HCl-HNO3 -HF-HClO4 ,calibrated by HCl(1+9) solution and deter-mined by AAS. The method achieved a recovery rate of 96. 9 % -107. 7 % with the addition of standard substance, the RSD(n=7) was 1. 17 % -7. 07 % and the detection limits were 0. 001 5 μg/mL for Cu,0. 029 9 μg/mL for Pb,0. 011 2 μg/mL for Zn,and 0. 001 9 μg/mL for Ag. The method for silver,copper,lead and zinc determination was consistent with national standard method.%针对金精矿日常化验中银、铜、铅、锌需分别溶样测定,浪费人力、时间,采用火焰原子吸收法一次溶样连续测定样品中的银、铜、铅、锌。金精矿采用盐酸-硝酸-氢氟酸-高氯酸混酸完全消解,盐酸(1+9)溶液定容,原子吸收光谱法进行测定。该方法加入标准物质回收率为96.9%~107.7%,相对标准偏差 RSD(n =7)为1.17%~7.07%,检出限分别为 Cu 0.0015μg/mL、Pb 0.0299μg/mL、Zn 0.0112μg/mL、Ag 0.0019μg/mL。该方法对金精矿中银、铜、铅、锌的测定结果与国家标准方法测定值相符。

  10. Extension of the Trusted Cloud Domain for the Composite Cloud Process

    Directory of Open Access Journals (Sweden)

    Sameer Rajan

    2012-05-01

    Full Text Available Internet is a "network of networks" that consists of millions of private and public, academic, business, and government networks of local to global scope that are linked by copper wires, fiber-opticcables, wireless connections, and other technologies. Cloud computing [1] is a new flavor of computing where our trend of using internet changes. It makes a virtual pool of resources such as storage, CPU,networks and memory to fulfill the user’s resource requirement and provides on demand (pay per use hardware and software services without barriers. It can be named as dynamic computing because itprovides resources, when required. Cloud Computing manages the pool of resources automatically and dynamically through software and hardware. Various businesses form their cloud for the users to providepay per use services. Users are required to access the cloud according to the service. In this way, user can get benefited from the proprietary cloud on cheap prices but it is difficult for the user to find the cloud that can fulfill his demand. It is also not safe for cloud to cloud communication without trust. To resolvesuch difficulties and various other issues, it is required to extend the trusted cloud domain for accessing the compatible services provided by other clouds.

  11. Copper tolerance of Trichoderma species

    Directory of Open Access Journals (Sweden)

    Jovičić-Petrović Jelena

    2014-01-01

    Full Text Available Some Trichoderma strains can persist in ecosystems with high concentrations of heavy metals. The aim of this research was to examine the variability of Trichoderma strains isolated from different ecosystems, based on their morphological properties and restriction analysis of ITS fragments. The fungal growth was tested on potato dextrose agar, amended with Cu(II concentrations ranging from 0.25 to 10 mmol/l, in order to identify copper-resistant strains. The results indicate that some isolated strains of Trichoderma sp. show tolerance to higher copper concentrations. Further research to examine the ability of copper bioaccumulation by tolerant Trichoderma strains is needed. [Projekat Ministarstva nauke Republike Srbije, br. TR 31080 i br. III 43010

  12. CELLULAR MULTITASKING: THE DUAL ROLE OF HUMAN CU-ATPASES IN COFACTOR DELIVERY AND INTRACELLULAR COPPER BALANCE

    OpenAIRE

    Lutsenko, Svetlana; Gupta, Arnab; Burkhead, Jason L.; Zuzel, Vesna

    2008-01-01

    The human copper-transporting ATPases (Cu-ATPases) are essential for dietary copper uptake, normal development and function of the CNS, and regulation of copper homeostasis in the body. In a cell, Cu-ATPases maintain the intracellular concentration of copper by transporting copper into intracellular exocytic vesicles. In addition, these P-type ATPases mediate delivery of copper to copper-dependent enzymes in the secretory pathway and in specialized cell compartments such as secretory granules...

  13. Alterations of Cloud Microphysics Due to Cloud Processed CCN

    Science.gov (United States)

    Hudson, J. G.; Tabor, S. S.; Noble, S. R., Jr.

    2015-12-01

    High-resolution CCN spectra have revealed bimodality (Hudson et al. 2015) similar to aerosol size spectra (e.g., Hoppel et al. 1985). Bimodality is caused by chemical and physical cloud processes that increase mass or hygroscopicity of only CCN that produced activated cloud droplets. Bimodality is categorized by relative CCN concentrations (NCCN) within the two modes, Nu-Np; i.e., NCCN within the higher critical supersaturation, Sc, mode that did not undergo cloud processing minus NCCN within the lower Sc mode that was cloud processed. Lower, especially negative, Nu-Np designates greater processing. The table shows regressions between Nu-Np and characteristics of clouds nearest the CCN measurements. ICE-T MASE parameter R SL R SL Nc 0.17 93.24 -0.26 98.65 MD -0.31 99.69 0.33 99.78 σ -0.27 99.04 0.48 100.00 Ld -0.31 99.61 0.38 99.96 Table. Correlation coefficients, R, and one-tailed significance levels in percent, SL, for Nu-Np with microphysics of the clouds closest to each CCN measurement, 75 ICE-T and 74 MASE cases. Nc is cloud droplet concentration, MD is cloud droplet mean diameter, σ is standard deviation of cloud droplet spectra, Ldis drizzle drop LWC. Two aircraft field campaigns, Ice in Clouds Experiment-Tropical (ICE-T) and Marine Stratus/Stratocumulus Experiment (MASE) show opposite R signs because coalescence dominated cloud processing in low altitude ICE-T cumuli whereas chemical transformations predominated in MASE low altitude polluted stratus. Coalescence reduces Nc and NCCN, which thus increases MD, and σ, which promote Ld. Chemical transformations, e.g., SO2 to SO4, increase CCN hygroscopicity, thus reducing Sc, but not affecting Nc or NCCN. Lower Sc CCN are capable of producing greater Nc in subsequent cloud cycles, which leads to lower MD and σ which reduce Ld (figure). These observations are consistent with cloud droplet growth models for the higher vertical wind (W) of cumuli and lower W of stratus. Coalescence thus reduces the indirect

  14. Climate Effects of Cloud Modified CCN-Cloud Interactions

    Science.gov (United States)

    Noble, S. R., Jr.; Hudson, J. G.

    2015-12-01

    Cloud condensation nuclei (CCN) play an important role in the climate system through the indirect aerosol effect (IAE). IAE is one of the least understood aspects of the climate system as many cloud processes are complicated. Many studies of aerosol-cloud interaction involve CCN interaction with cloud droplet concentrations (Nc), cloud microphysics, and radiative properties. However, fewer studies investigate how cloud processes modify CCN. Upon evaporation from non-precipitating clouds, CCN distributions develop bimodal shaped distributions (Hoppel et al. 1986). Activated CCN participate in cloud processing that is either chemical: aqueous oxidation; or physical: Brownian scavenging, collision and coalescence. Chemical processing does not change CCN concentration (NCCN) but reduces critical supersaturations (Sc; larger size) (Feingold and Kreidenweis, 2000) while physical processing reduces NCCN and Sc. These processes create the minima in the bimodal CCN distributions (Hudson et al., 2015). Updraft velocity (W) and NCCN are major factors on how these modified CCN distributions affect clouds. Panel a shows two nearby CCN distributions in the MArine Stratus/stratocumulus Experiment (MASE), which have similar concentrations, but the bimodal one (red) has been modified by cloud processing. In a simplified cloud droplet model, the modified CCN then produces higher Nc (panel b) and smaller droplet mean diameters (MD; panel c) when compared to the unmodified CCN (black) for W lower than 50 cm/s. The better CCN (lower Sc) increase competition among droplets reducing MD and droplet distribution spread (σ) which acts to reduce drizzle. Competition is created by limited available condensate due to lower S created by the low W (50 cm/s) typical of cumuli, Ncis reduced and MD is increased from the modified CCN distribution (panels b & c). Here, CCN cloud processing increases MD and σ leading to increased drizzle. Improved climate prediction requires a better understanding

  15. [Evaluation of the exposure to copper and other non-ferrous metals in copper foundries].

    Science.gov (United States)

    Linscheid, D

    1985-01-01

    Working environment has been evaluated in two copper metallurgy plants by analysis of Cu and other metals (Pb, Cd, Zn) concentrations. At the Charge Preparation Department the greatest concentrations of Cu and Pb were found. Copper concentrations at Metallurgy Department (shaft furnace, converter and anodic furnace) oscillate between 0.1-0.5 mg/m3, and Pb 0.06-0.71 mg/m3. In order to accurately evaluate copper exposure at working places where copper fume may arise (Metallurgy Department) it is necessary to determine Cu concentrations in respirable dust. At other working places Cu, Pb and Zn concentrations were low. Cadmium appears in vestigial amounts. The quantitative analysis indicates that airborne copper at the Charge Preparation Department and at the shaft furnace appears as CuS, at converter as Cu2O, and at other working places as metal Cu.

  16. A novel cloud point extraction approach using cationic surfactant for the separation and pre-concentration of chromium species in natural water prior to ICP-DRC-MS determination.

    Science.gov (United States)

    Meeravali, Noorbasha N; Jiang, Shiuh-Jen

    2009-11-15

    A novel cloud point phase separation of cationic surfactant, Aliquat-336 and capabilities of its reactive solubilizing sites for selective extraction of chromium species at ultra trace levels was examined in natural water. The phase separation behavior of Aliquat-336 is studied with various additives. The nonionic surfactant, Triton X-114 was found to induce the cloud point phase separation of Aliquat-336. The separation of anionic Cr(VI) was enabled by the formation of ion associate with quaternary ammonium head group of Aliquat-336 at pH 2, and the recovery of Cr(VI) and Cr(III) were 101.4+/-1.4% and 2.2+/-0.4%, respectively at 0.5-1 ng mL(-1), Total Cr was pre-concentrated as Cr-APDC species using the hydrophobic tail group at pH 6.5. The Cr(III) concentration was obtained by subtracting Cr(VI) from total Cr. The recovery of total Cr was 99.5+/-1.2%. Parameters affecting extraction were assessed. The procedure was applied to NIST 1643c and NIST 1643d waters, and the sum of individual species obtained was compared with the certified chromium values. The method was also applied to various natural waters with limits of detection and pre-concentration factor of 0.010 and 0.025 ng mL(-1); 10 and 10, respectively, for Cr(VI) and Cr(III)-APDC using ICP-MS operated in DRC mode.

  17. Mobile Clouds

    DEFF Research Database (Denmark)

    Fitzek, Frank; Katz, Marcos

    users in very different ways and for various purposes. The book provides many stimulating examples of resource-sharing applications. Enabling technologies for mobile clouds are also discussed, highlighting the key role of network coding. Mobile clouds have the potential to enhance communications...... of resource sharing takes a wider and deeper meaning, creating the foundations for a global real-time multidimensional resource pool, the underlying infrastructure for shareconomy. Above all, this is an inspiring book for anyone who is concerned about the future of wireless and mobile communications networks...... and their relationship with Social networks. Key Features: Provides fundamental ideas and promising concepts for exploiting opportunistic cooperation and cognition in wireless and mobile networks Gives clear definitions of mobile clouds from different perspectives Associates mobile and wireless networks with social...

  18. Global simulations of aerosol processing in clouds

    Directory of Open Access Journals (Sweden)

    C. Hoose

    2008-12-01

    Full Text Available An explicit and detailed representation of in-droplet and in-crystal aerosol particles in stratiform clouds has been introduced in the global aerosol-climate model ECHAM5-HAM. The new scheme allows an evaluation of the cloud cycling of aerosols and an estimation of the relative contributions of nucleation and collision scavenging, as opposed to evaporation of hydrometeors in the global aerosol processing by clouds. On average an aerosol particle is cycled through stratiform clouds 0.5 times. The new scheme leads to important changes in the simulated fraction of aerosol scavenged in clouds, and consequently in the aerosol wet deposition. In general, less aerosol is scavenged into clouds with the new prognostic treatment than what is prescribed in standard ECHAM5-HAM. Aerosol concentrations, size distributions, scavenged fractions and cloud droplet concentrations are evaluated and compared to different observations. While the scavenged fraction and the aerosol number concentrations in the marine boundary layer are well represented in the new model, aerosol optical thickness, cloud droplet number concentrations in the marine boundary layer and the aerosol volume in the accumulation and coarse modes over the oceans are overestimated. Sensitivity studies suggest that a better representation of below-cloud scavenging, higher in-cloud collision coefficients, or a reduced water uptake by seasalt aerosols could reduce these biases.

  19. Global simulations of aerosol processing in clouds

    Directory of Open Access Journals (Sweden)

    C. Hoose

    2008-07-01

    Full Text Available An explicit and detailed representation of in-droplet and in-crystal aerosol particles in stratiform clouds has been introduced in the global aerosol-climate model ECHAM5-HAM. The new scheme allows an evaluation of the cloud cycling of aerosols and an estimation of the relative contributions of nucleation and collision scavenging, as opposed to evaporation of hydrometeors in the global aerosol processing by clouds. On average an aerosol particle is cycled through stratiform clouds 0.5 times. The new scheme leads to important changes in the simulated fraction of aerosol scavenged in clouds, and consequently in the aerosol wet deposition. In general, less aerosol is scavenged into clouds with the new prognostic treatment than what is prescribed in standard ECHAM5-HAM. Aerosol concentrations, size distributions, scavenged fractions and cloud droplet concentrations are evaluated and compared to different observations. While the scavenged fraction and the aerosol number concentrations in the marine boundary layer are well represented in the new model, aerosol optical thickness, cloud droplet number concentrations in the marine boundary layer and the aerosol volume in the accumulation and coarse modes over the oceans are overestimated. Sensitivity studies suggest that a better representation of below-cloud scavenging, higher in-cloud collision coefficients, or a reduced water uptake by seasalt aerosols could reduce these biases.

  20. Copper metallurgy at the crossroads

    Directory of Open Access Journals (Sweden)

    Habashi F.

    2007-01-01

    Full Text Available Copper technology changed from the vertical to the horizontal furnace and from the roast reaction to converting towards the end of the last century. However, the horizontal furnace proved to be an inefficient and polluting reactor. As a result many attempts were made to replace it. In the past 50 years new successful melting processes were introduced on an industrial scale that were more energy efficient and less polluting. In addition, smelting and converting were conducted in a single reactor in which the concentrate was fed and the raw copper was produced. The standing problem in many countries, however, is marketing 3 tonnes of sulfuric acid per tonne of copper produced as well as emitting large amounts of excess SO2 in the atmosphere. Pressure hydrometallurgy offers the possibility of liberating the copper industry from SO2 problem. Heap leaching technology has become a gigantic operation. Combined with solvent extraction and electrowinning it contributes today to about 20% of copper production and is expected to grow. Pressure leaching offers the possibility of liberating the copper industry from SO2 problem. The technology is over hundred years old. It is applied for leaching a variety of ores and concentrates. Hydrothermal oxidation of sulfide concentrates has the enormous advantage of producing elemental sulfur, hence solving the SO2 and sulfuric acid problems found in smelters. Precipitation of metals such as nickel and cobalt under hydrothermal conditions has been used for over 50 years. It has the advantage of a compact plant but the disadvantage of producing ammonium sulfate as a co-product. In case of copper, however, precipitation takes place without the need of neutralizing the acid, which is a great advantage and could be an excellent substitute for electrowinning which is energy intensive and occupies extensive space. Recent advances in the engineering aspects of pressure equipment design open the door widely for increased

  1. A cloud-resolving model study of aerosol-cloud correlation in a pristine maritime environment

    Science.gov (United States)

    Nishant, Nidhi; Sherwood, Steven C.

    2017-06-01

    In convective clouds, satellite-observed deepening or increased amount of clouds with increasing aerosol concentration has been reported and is sometimes interpreted as aerosol-induced invigoration of the clouds. However, such correlations can be affected by meteorological factors that affect both aerosol and clouds, as well as observational issues. In this study, we examine the behavior in a 660 × 660 km2 region of the South Pacific during June 2007, previously found by Koren et al. (2014) to show strong correlation between cloud fraction, cloud top pressure, and aerosols, using a cloud-resolving model with meteorological boundary conditions specified from a reanalysis. The model assumes constant aerosol loading, yet reproduces vigorous clouds at times of high real-world aerosol concentrations. Days with high- and low-aerosol loading exhibit deep-convective and shallow clouds, respectively, in both observations and the simulation. Synoptic analysis shows that vigorous clouds occur at times of strong surface troughs, which are associated with high winds and advection of boundary layer air from the Southern Ocean where sea-salt aerosol is abundant, thus accounting for the high correlation. Our model results show that aerosol-cloud relationships can be explained by coexisting but independent wind-aerosol and wind-cloud relationships and that no cloud condensation nuclei effect is required.

  2. Copper deficiency in a herd of captive muskoxen.

    OpenAIRE

    Blakley, B R; S. C. Tedesco; Flood, P F

    1998-01-01

    At necropsy, a mature muskox cow was found to have exceedingly low serum and liver copper concentrations of 4.8 = mumol/L and 0.02 mmol/kg, respectively. Serum copper levels were also low in remaining members of the herd but returned to normal after parenteral treatment with calcium copper edetate.

  3. Cloud radiative properties and aerosol - cloud interaction

    Science.gov (United States)

    Viviana Vladutescu, Daniela; Gross, Barry; Li, Clement; Han, Zaw

    2015-04-01

    The presented research discusses different techniques for improvement of cloud properties measurements and analysis. The need for these measurements and analysis arises from the high errors noticed in existing methods that are currently used in retrieving cloud properties and implicitly cloud radiative forcing. The properties investigated are cloud fraction (cf) and cloud optical thickness (COT) measured with a suite of collocated remote sensing instruments. The novel approach makes use of a ground based "poor man's camera" to detect cloud and sky radiation in red, green, and blue with a high spatial resolution of 30 mm at 1km. The surface-based high resolution photography provides a new and interesting view of clouds. As the cloud fraction cannot be uniquely defined or measured, it depends on threshold and resolution. However as resolution decreases, cloud fraction tends to increase if the threshold is below the mean, and vice versa. Additionally cloud fractal dimension also depends on threshold. Therefore these findings raise concerns over the ability to characterize clouds by cloud fraction or fractal dimension. Our analysis indicate that Principal Component analysis may lead to a robust means of quantifying cloud contribution to radiance. The cloud images are analyzed in conjunction with a collocated CIMEL sky radiometer, Microwave Radiometer and LIDAR to determine homogeneity and heterogeneity. Additionally, MFRSR measurements are used to determine the cloud radiative properties as a validation tool to the results obtained from the other instruments and methods. The cloud properties to be further studied are aerosol- cloud interaction, cloud particle radii, and vertical homogeneity.

  4. A limited legacy effect of copper in marine biofilms.

    Science.gov (United States)

    McElroy, David J; Doblin, Martina A; Murphy, Richard J; Hochuli, Dieter F; Coleman, Ross A

    2016-08-15

    The effects of confounding by temporal factors remains understudied in pollution ecology. For example, there is little understanding of how disturbance history affects the development of assemblages. To begin addressing this gap in knowledge, marine biofilms were subjected to temporally-variable regimes of copper exposure and depuration. It was expected that the physical and biological structure of the biofilms would vary in response to copper regime. Biofilms were examined by inductively coupled plasma optical emission spectrometry, chlorophyll-a fluorescence and field spectrometry and it was found that (1) concentrations of copper were higher in those biofilms exposed to copper, (2) concentrations of copper remain high in biofilms after the source of copper is removed, and (3) exposure to and depuration from copper might have comparable effects on the photosynthetic microbial assemblages in biofilms. The persistence of copper in biofilms after depuration reinforces the need for consideration of temporal factors in ecology.

  5. Raman spectroscopy for the evaluation of the effects of different concentrations of Copper on the chemical composition and biological activity of basil essential oil

    Science.gov (United States)

    Nawaz, Haq; Hanif, Muhammad Asif; Ayub, Muhammad Adnan; Ishtiaq, Faiqa; Kanwal, Nazish; Rashid, Nosheen; Saleem, Muhammad; Ahmad, Mushtaq

    2017-10-01

    The present study is performed to evaluate the effect of different concentrations of Cu as fertilizer on the chemical composition of basil essential oil and its biological activity including antioxidant and antifungal activities by employing Raman spectroscopy. Moreover, the effect of Cu is also determined on the vegetative growth and essential oil yield. Both, antifungal and antioxidant activities were found to be maximum with essential oils obtained at 0.04 mg/l concentration of Cu fertilizer. The results of the GC-MS and Raman spectroscopy have revealed that the linalool and estragole are found to be as a major chemical compound in basil essential oil. The Raman spectral changes associated with these biological components lead to the conclusion that estragole seems to have dominating effect in the biological activities of the basil essential oil as compared to linalool although the latter is observed in greater concentration.

  6. Parameterization of clouds and radiation in climate models

    Energy Technology Data Exchange (ETDEWEB)

    Roeckner, E. [Max Planck Institute for Meterology, Hamburg (Germany)

    1995-09-01

    Clouds are a very important, yet poorly modeled element in the climate system. There are many potential cloud feedbacks, including those related to cloud cover, height, water content, phase change, and droplet concentration and size distribution. As a prerequisite to studying the cloud feedback issue, this research reports on the simulation and validation of cloud radiative forcing under present climate conditions using the ECHAM general circulation model and ERBE top-of-atmosphere radiative fluxes.

  7. Effects of dietary sulfur and distillers dried grains with solubles on carcass characteristics, loin quality, and tissue concentrations of sulfur, selenium, and copper in growing-finishing pigs.

    Science.gov (United States)

    Kim, B G; Kil, D Y; Mahan, D C; Hill, G M; Stein, H H

    2014-10-01

    Inclusion of up to 0.38% S in diets that contain 30% distillers dried grains with solubles (DDGS) has no negative effect on growth performance of growing-finishing pigs, but there is no information about the effects of dietary S on accumulation of S in tissues in pigs. Therefore, the objective of this experiment was to determine if the concentration of S in diets containing DDGS affects carcass characteristics, loin quality, or tissue mineral concentrations in growing-finishing pigs. A total of 120 barrows (34.2 ± 2.3 kg BW) were allotted to 3 dietary treatments with 10 replicate pens and 4 pigs per pen in a randomized complete block design. Pigs were fed grower diets for 42 d and finisher diets for 42 d. At the conclusion of the experiment, the pig in each pen with the BW closest to the pen average was slaughtered. The control diet was based on corn and soybean meal and the finisher diet contained 0.14% S, 0.19 mg/kg Se, and 15.3 mg/kg Cu. The DDGS diet was formulated with corn, soybean meal, and 30% DDGS and the finisher diet with DDGS contained 0.16% S, 0.32 mg/kg Se, and 14.0 mg/kg Cu. The DDGS plus S (DDGS-S) diet was similar to the DDGS diet, except that 1.10% CaSO4 (16.2% S) was included in this diet, and the finisher diet with DDGS-S contained 0.37% S, 0.35 mg/kg Se, and 13.8 mg/kg Cu. Results indicated that organ weights and loin quality, 24-h pH, drip loss, loin subjective color, marbling, and firmness did not differ among treatments, but loin a* was greater (P pigs fed the control diet than for pigs fed the DDGS-S diet. Concentrations of S in hair, liver, heart, loin, and all other tissues did not differ among treatments, but urinary S concentration was greater (P pigs fed the DDGS-S diet than for pigs fed the other diets. Pigs fed the DDGS diet or the DDGS-S diet had greater (P pigs fed the control diet, but liver concentrations of Cu did not differ among treatments. In conclusion, inclusion of 30% DDGS in diets fed to growing-finishing pigs did not

  8. Copper, zinc, and iron bioleaching from polymetallic sulphide concentrate%多金属硫化精矿中铜、锌和铁的生物浸出

    Institute of Scientific and Technical Information of China (English)

    Vesna T. CONIĆ; Mirjana M. RAJČIĆ VUJASINOVIĆ; Vlastimir K. TRUJIĆ; Vladimir B. CVETKOVSKI

    2014-01-01

    Bioleaching of low-grade complex Cu−Zn−Pb−Fe−Ag−Au sulphide concentrate (of Majdanpek ore body, RTB Bor, Serbia) was carried out in an aerated bioleach reactor in the presence of mesophilic mixed bacterial culture ofAcidithiobacillus ferrooxidans,Acidithiobacillus thiooxidans, andLeptospirillum ferrooxidans. A mesophilic acidophiles culture was isolated from the acidic solution of the underground copper mine of Bor, Serbia. The nutrient medium was 9K at pH 1.6. 87% of the particles were<10 µm in size, with a pulp density of 8% (w/v). Bioleaching efficiencies of 89% for zinc, 83% for copper, and 68% for iron can be achieved in the examined conditions. Kinetic analysis shows that the change in leaching corresponds to the Spencer-Topley kinetic model for diffusion-controlled topochemical reactions.%利用嗜温混合菌Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans和 Leptospirillum ferrooxidans对低品位复杂Cu−Zn−Pb−Fe−Ag−Au硫化精矿在曝气生物浸出反应器中进行生物浸出。该菌种为从塞尔维亚Bor地下铜矿的酸性溶液中筛选出一种嗜热嗜酸菌。营养液为pH 1.6的9K营养液。87%的矿物粒度大于10μm,矿浆密度为8%(w/v)。在测试条件下,锌、铜和铁的浸出率分别达到89%、83%和68%。动力学分析表明,浸出过程与Spencer-Topley模型相符,受局部反应扩散控制。

  9. Mobile Clouds

    DEFF Research Database (Denmark)

    Fitzek, Frank; Katz, Marcos

    examples of mobile clouds applications, based on both existing commercial initiatives as well as proof-of-concept test-beds. Visions and prospects are also discussed, paving the way for further development. As mobile networks and social networks become more and more reliant on each other, the concept...

  10. Soft Clouding

    DEFF Research Database (Denmark)

    Søndergaard, Morten; Markussen, Thomas; Wetton, Barnabas;

    2012-01-01

    Soft Clouding is a blended concept, which describes the aim of a collaborative and transdisciplinary project. The concept is a metaphor implying a blend of cognitive, embodied interaction and semantic web. Furthermore, it is a metaphor describing our attempt of curating a new semantics of sound...

  11. Simulated small-scale pilot heap leaching of low-grade copper sulfide ore with selective extraction of copper

    Institute of Scientific and Technical Information of China (English)

    QIN Wen-qing; ZHANG Yan-sheng; LI Wei-zhong; WANG Jun

    2008-01-01

    The bioleaching of low-grade copper sulfide ore and the selective extraction of copper were investigated.Lix984 dissolved in kerosene was used as extractant.The results show that it is possible to selectively leach copper from the ores by heap leaching.The copper concentration of leaching liquor after 250 d is 2.17 g/L,and the copper concentration is 0.27 g/L after solvent extraction.The leach liquor was subjected to solvent extraction,scrubbing and selective stripping for the enrichment of copper and the removal of impurities.The pregnant copper sulfate solution produced from the stripping cycle is suitable for copper electro-winning.

  12. Evaluation of copper resistant bacteria from vineyard soils and mining waste for copper biosorption

    Science.gov (United States)

    Andreazza, R.; Pieniz, S.; Okeke, B.C.; Camargo, F.A.O

    2011-01-01

    Vineyard soils are frequently polluted with high concentrations of copper due application of copper sulfate in order to control fungal diseases. Bioremediation is an efficient process for the treatment of contaminated sites. Efficient copper sorption bacteria can be used for bioremoval of copper from contaminated sites. In this study, a total of 106 copper resistant bacteria were examined for resistance to copper toxicity and biosorption of copper. Eighty isolates (45 from vineyard Mollisol, 35 from Inceptisol) were obtained from EMBRAPA (Empresa Brasileira de Pesquisa Agropecuária) experimental station, Bento Gonçalves, RS, Brazil (29°09′53.92″S and 51°31′39.40″W) and 26 were obtained from copper mining waste from Caçapava do Sul, RS, Brazil (30°29′43.48″S and 53′32′37.87W). Based on resistance to copper toxicity and biosorption, 15 isolates were identified by 16S rRNA gene sequencing. Maximal copper resistance and biosorption at high copper concentration were observed with isolate N2 which removed 80 mg L−1 in 24 h. Contrarily isolate N11 (Bacillus pumilus) displayed the highest specific copper biosorption (121.82 mg/L/OD unit in 24 h). GenBank MEGABLAST analysis revealed that isolate N2 is 99% similar to Staphylococcus pasteuri. Results indicate that several of our isolates have potential use for bioremediation treatment of vineyards soils and mining waste contaminated with high copper concentration. PMID:24031606

  13. Leaching of copper-ethanolamine based preservatives from wood

    OpenAIRE

    Humar, Miha

    2006-01-01

    Copper-ethanolamine based preservatives are successfully replacing classical copper-chromium based preservative solutions. In this paper, the proposed fixation mechanisms are described. Additionaly,basic facts that influence copper leaching from wood are elucidated: composition and concentration of solutions, time and temperature of fixation as well as wood species and treatment method used. The results show that addition of ethanolamine significiantly improves copper fixation, but can on the...

  14. Monitoring copper in Wilson's disease.

    Science.gov (United States)

    Walshe, J M

    2010-01-01

    Monitoring copper metabolism in patients with Wilson's disease is not an exact science. At present, there are no simple methods of estimating the total body load of this metal. Indirect methods must therefore be used. A survey of the current literature shows that most approaches rely on the determination of blood and urine copper concentration. Both these should decrease with treatment. In parallel with decreased copper concentration, there should be subsequent improvement in more routine laboratory tests including liver and renal function, blood count parameters, and clotting factors. Lack of compliance is revealed by a reversal of this trend. This chapter critically reviews current testing methods and describes other approaches that may be helpful.

  15. Effect of dietary buffer additions on gain, efficiency, duodenal pH, and copper concentration in liver of Eimeria acervulina-infected chicks.

    Science.gov (United States)

    Fox, M C; Brown, D R; Southern, L L

    1987-03-01

    Three experiments were conducted with broiler chicks to investigate the effect of dietary additions of NaHCO3(1%), A1(OH)3(.5%), kaolin(1%), A1(OH)2NaCO3(.23%), CaCO3(.37%), and MgO(1%) on gain, efficiency, duodenal pH, and liver Cu concentration of Eimeria acervulina-infected chicks. Experimental coccidial infection consistently reduced chick gain, efficiency, and duodenal pH, but it increased liver Cu concentration of chicks fed excess Cu. Sodium bicarbonate addition improved chick gain and efficiency slightly, whereas the MgO addition reduced these performance criteria. Sodium bicarbonate improved gain more in coccidiosis-infected chicks than in uninfected chicks, but it failed to alleviate, to any extent, the coccidiosis-induced liver Cu increase of the duodenal pH decrease.

  16. Improving Beneficiation of Copper and Iron from Copper Slag by Modifying the Molten Copper Slag

    Directory of Open Access Journals (Sweden)

    Zhengqi Guo

    2016-04-01

    Full Text Available In the paper, a new technology was developed to improve the beneficiation of copper and iron components from copper slag, by modifying the molten slag to promote the mineralization of valuable minerals and to induce the growth of mineral grains. Various parameters, including binary basicity, dosage of compound additive, modification temperature, cooling rate and the end point temperature of slow cooling were investigated. Meanwhile, optical microscope, scanning electron microscope and energy dispersive spectrometer (SEM-EDS was employed to determine the mineralogy of the modified and unmodified slag, as well as to reveal the mechanisms of enhancing beneficiation. The results show that under the proper conditions, the copper grade of rougher copper concentrate was increased from 6.43% to 11.04%, iron recovery of magnetic separation was increased significantly from 32.40% to 63.26%, and other evaluation indexes were changed slightly, in comparison with unmodified copper slag. Moreover, matte and magnetite grains in the modified slag aggregated together and grew obviously to the mean size of over 50 μm, resulting in an improvement of beneficiation of copper and iron.

  17. Effects of Copper Pollution on the Phenolic Compound Content, Color, and Antioxidant Activity of Wine.

    Science.gov (United States)

    Sun, Xiangyu; Ma, Tingting; Han, Luyang; Huang, Weidong; Zhan, Jicheng

    2017-05-03

    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.

  18. Direct Production of Copper

    Science.gov (United States)

    Victorovich, G. S.; Bell, M. C.; Diaz, C. M.; Bell, J. A. E.

    1987-09-01

    The use of commercially pure oxygen in flash smelting a typical chalcopyrite concentrate or a low grade comminuted matte directly to copper produces a large excess of heat. The heat balance is controlled by adjusting the calorific value of the solid feed. A portion of the sulfide material is roasted to produce a calcine which is blended with unroasted material, and the blend is then autogeneously smelted with oxygen and flux directly to copper. Either iron silicate or iron calcareous slags are produced, both being subject to a slag cleaning treatment. Practically all of the sulfur is contained in a continuous stream of SO2 gas, most of which is strong enough for liquefaction. A particularly attractive feature of these technologies is that no radically new metallurgical equipment needs to be developed. The oxygen smelting can be carried out not only in the Inco type flash furnace but in other suitable smelters such as cyclone furnaces. Another major advantage stems from abolishion of the ever-troublesome converter aisle, which is replaced with continuous roasting of a fraction of the copper sulfide feed.

  19. Effect of dietary organic zinc, manganese, copper, and cobalt supplementation on milk production, follicular growth, embryo quality, and tissue mineral concentrations in dairy cows.

    Science.gov (United States)

    Hackbart, K S; Ferreira, R M; Dietsche, A A; Socha, M T; Shaver, R D; Wiltbank, M C; Fricke, P M

    2010-12-01

    This study evaluated potential effects of organic trace mineral supplementation on reproductive measures in lactating dairy cows. Cows were blocked by breed and randomly assigned at dry-off to receive inorganic trace mineral supplementation (control; n = 32) or to have a portion of supplemental inorganic Zn, Cu, Mn, and Co replaced with an equivalent amount of the organic forms of these minerals (treatment; n = 31). Trace minerals were provided through control or treatment premixes fed at 100 g·cow(-1)·d(-1). Premixes were fed to dry cows (range = 40 to 72 d before calving) in 1.8 kg·cow(-1)·d(-1) concentrate pellets through a computer feeder to provide 40, 26, 70, and 100% of supplemented Zn, Mn, Cu, and Co, respectively, and to lactating cows (range = 69 to 116 d after calving) in a total mixed ration to provide 22, 14, 40, and 100% of supplemented Zn, Mn, Cu, and Co, respectively. Treatment increased milk production at wk 14 (P = 0.047) postcalving, milk urea N content (P = 0.039), and BW loss from calving to 1 mo postcalving (P = 0.040), and decreased milk fat percentage (P = 0.045) and BCS (P = 0.048). Treatment tended to increase milk production at wk 13 (P = 0.089) postcalving and endometrial tissue concentrations of Fe (P = 0.070), BW at mo 1 (P = 0.056), and milk protein percentage (P = 0.064). Treatment did not affect (P > 0.1) DMI, health events, first-wave follicular dynamics, first cycle luteal measures, embryo quality, liver trace mineral concentrations, or luteal trace mineral concentrations. Cows with a rectal temperature ≥39°C at the time of AI had a smaller percentage of fertilized entities (P 0.1) by treatment. We conclude that replacing a portion of inorganic supplemental trace minerals with an equivalent amount of these organic trace minerals (Zn, Mn, Cu, and Co) increased milk production in mid-lactation, but did not affect postpartum follicular dynamics, embryo quality, or liver and luteal trace mineral concentrations.

  20. Cloud management and security

    CERN Document Server

    Abbadi, Imad M

    2014-01-01

    Written by an expert with over 15 years' experience in the field, this book establishes the foundations of Cloud computing, building an in-depth and diverse understanding of the technologies behind Cloud computing. In this book, the author begins with an introduction to Cloud computing, presenting fundamental concepts such as analyzing Cloud definitions, Cloud evolution, Cloud services, Cloud deployment types and highlighting the main challenges. Following on from the introduction, the book is divided into three parts: Cloud management, Cloud security, and practical examples. Part one presents the main components constituting the Cloud and federated Cloud infrastructure(e.g., interactions and deployment), discusses management platforms (resources and services), identifies and analyzes the main properties of the Cloud infrastructure, and presents Cloud automated management services: virtual and application resource management services. Part two analyzes the problem of establishing trustworthy Cloud, discuss...

  1. Copper allergy from dental copper amalgam?

    Science.gov (United States)

    Gerhardsson, Lars; Björkner, Bert; Karlsteen, Magnus; Schütz, Andrejs

    2002-05-06

    A 65-year-old female was investigated due to a gradually increasing greenish colour change of her plastic dental splint, which she used to prevent teeth grinding when sleeping. Furthermore, she had noted a greenish/bluish colour change on the back of her black gloves, which she used to wipe her tears away while walking outdoors. The investigation revealed that the patient had a contact allergy to copper, which is very rare. She had, however, had no occupational exposure to copper. The contact allergy may be caused by long-term exposure of the oral mucosa to copper from copper-rich amalgam fillings, which were frequently used in childhood dentistry up to the 1960s in Sweden. The deposition of a copper-containing coating on the dental splint may be caused by a raised copper intake from drinking water, increasing the copper excretion in saliva, in combination with release of copper due to electrochemical corrosion of dental amalgam. The greenish colour change of the surface of the splint is probably caused by deposition of a mixture of copper compounds, e.g. copper carbonates. Analysis by the X-ray diffraction technique indicates that the dominant component is copper oxide (Cu2O and CuO). The corresponding greenish/bluish discoloration observed on the back of the patient's gloves may be caused by increased copper excretion in tears.

  2. The kinetic chemistry of dense interstellar clouds

    Science.gov (United States)

    Graedel, T. E.; Langer, W. D.; Frerking, M. A.

    1982-01-01

    A model of the time-dependent chemistry of dense interstellar clouds is formulated to study the dominant chemical processes in carbon and oxygen isotope fractionation, the formation of nitrogen-containing molecules, and the evolution of product molecules as a function of cloud density and temperature. The abundances of the dominant isotopes of the carbon- and oxygen-bearing molecules are calculated. The chemical abundances are found to be quite sensitive to electron concentration since the electron concentration determines the ratio of H3(+) to He(+), and the electron density is strongly influenced by the metals abundance. For typical metal abundances and for H2 cloud density not less than 10,000 molecules/cu cm, nearly all carbon exists as CO at late cloud ages. At high cloud density, many aspects of the chemistry are strongly time dependent. Finally, model calculations agree well with abundances deduced from observations of molecular line emission in cold dense clouds.

  3. Death of an Arctic Mixed Phase Cloud: How Changes in the Arctic Environment Influence Cloud Properties and Cloud Radiative Feedbacks

    Science.gov (United States)

    Roesler, E. L.; Posselt, D. J.

    2012-12-01

    Arctic mixed phase stratocumulus clouds exert an important influence on the radiative budget over the Arctic ocean and sea ice. Field programs and numerical experiments have shown the properties of these clouds to be sensitive to changes in the surface properties, thermodynamic environment, and aerosols. While it is clear that Arctic mixed-phase clouds respond to changes in the Arctic environment, uncertainty remains as to how climate warming will affect the cloud micro- and macrophysical properties. This is in no small part due to the fact that there are nonlinear interactions between changes in atmospheric and surface properties and changes in cloud characteristics. In this study, large-eddy simulations are performed of an arctic mixed phase cloud observed during the Indirect and Semi-Direct Aerosol Campaign. A parameter-space-filling uncertainty quantification technique is used to rigorously explore how simulated arctic mixed phase clouds respond to changes in the properties of the environment. Specifically, the cloud ice and aerosol concentration, surface sensible and latent heat fluxes, and large scale temperature, water vapor, and vertical motion are systematically changed, and the properties of the resulting clouds are examined. It is found that Arctic mixed phase clouds exhibit four characteristic behaviors: stability, growth, decay, and dissipation. Sets of environmental and surface properties that lead to the emergence of each type of behavior are presented, and the implications for the response of Arctic clouds to changes in climate are explored.

  4. Cloud Computing

    DEFF Research Database (Denmark)

    Krogh, Simon

    2013-01-01

    The second half of the 20th century has been characterized by an explosive development in information technology (Maney, Hamm, & O'Brien, 2011). Processing power, storage capacity and network bandwidth have increased exponentially, resulting in new possibilities and shifting IT paradigms. In step...... with technological changes, the paradigmatic pendulum has swung between increased centralization on one side and a focus on distributed computing that pushes IT power out to end users on the other. With the introduction of outsourcing and cloud computing, centralization in large data centers is again dominating...... the IT scene. In line with the views presented by Nicolas Carr in 2003 (Carr, 2003), it is a popular assumption that cloud computing will be the next utility (like water, electricity and gas) (Buyya, Yeo, Venugopal, Broberg, & Brandic, 2009). However, this assumption disregards the fact that most IT production...

  5. Electron Percolation In Copper Infiltrated Carbon

    Science.gov (United States)

    Krcho, Stanislav

    2015-11-01

    The work describes the dependence of the electrical conductivity of carbon materials infiltrated with copper in a vacuum-pressure autoclave on copper concentration and on the effective pore radius of the carbon skeleton. In comparison with non-infiltrated material the electrical conductivity of copper infiltrated composite increased almost 500 times. If the composite contained less than 7.2 vol% of Cu, a linear dependence of the electrical conductivity upon cupper content was observed. If infiltrated carbon contained more than 7.2 vol% of Cu, the dependence was nonlinear - the curve could be described by a power formula (x - xc)t. This is a typical formula describing the electron percolation process in regions containing higher Cu fraction than the critical one. The maximum measured electrical conductivity was 396 × 104 Ω-1 m-1 for copper concentration 27.6 vol%. Experiments and analysis of the electrical conductivity showed that electron percolation occurred in carbon materials infiltrated by copper when the copper volume exceeded the critical concentration. The analysis also showed a sharp increase of electrical conductivity in composites with copper concentration higher than the threshold, where the effective radius of carbon skeleton pores decreased to 350 nanometres.

  6. Copper Products Capacity Expansion Stimulate the Copper Consumption

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    <正>The dramatic growth of copper consumption in China can directly be seen from the expansion of copper products capacity.According to sta- tistics,in the past 4 years,the improvement on the balance of trade on copper bar,copper,and copper alloy and copper wire & cable has driven the growth of copper consumption a lot.

  7. Effect of high dietary zinc oxide on the caecal and faecal short-chain fatty acids and tissue zinc and copper concentration in pigs is reversible after withdrawal of the high zinc oxide from the diet.

    Science.gov (United States)

    Janczyk, P; Büsing, K; Dobenecker, B; Nöckler, K; Zeyner, A

    2015-04-01

    Zinc oxide (ZnO) used in high ('pharmacological') levels to prevent diarrhoea in pigs is assumed to reduce copper (Cu) in tissues and inhibits large intestinal microbial fermentation. To test it, German Landrace pigs were weaned on d28 of age and fed diets containing either 100 (LowZinc, LZn, n = 10) or 3100 mg ZnO/kg (HighZinc, HZn, n = 10). The mixed feed (13.0 MJ ME, 18.5% crude protein) was based on wheat, barley, soya bean meal and maize. After 4 weeks, the HZn group was further fed 100 mg ZnO/kg for another 2 weeks. Caecal contents, faeces and tissues were collected after 4 weeks (n = 5 and n = 10 respectively) and 6 weeks (n = 5 and n = 5 respectively). Faeces and caecal content were analysed for dry matter (DM), pH, ammonia, lactic acid (LA) and short-chain fatty acids (SCFA) on native water basis. anova was performed to elucidate significant differences at p 0.05) were recorded in caecal contents after 6 weeks. In faeces, acetic acid remained lower in the HZn group in comparison with LZn (p = 0.006), as did the A:P ratio (p = 0.004). Zn concentration in liver, kidneys and ribs, and Cu concentrations in kidneys increased in HZn. Withdrawal of ZnO resulted in reversibility of the changes. The effect on butyric acid should be discussed critically regarding the energetic support for the enterocytes. High Zn and Cu tissue concentrations should be considered by pet food producers.

  8. Equilibrium Copper Strip Points as a Function of Temperature and Other Operating Parameters: Implications for Commercial Copper Solvent Extraction Plants

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The development of pressure and bioleaching processes for high grade copper ores and concentrates will result in copper solvent extraction plants treating solutions with high copper and acid concentrations at temperatures up to 45C and these copper solvent extraction plants will run with reagent concentrations up to 40 vol.%. There is also a trend to use copper stripping solutions with less acid than typically used in recent years. Cognis has developed a model that accurately predicts the copper strip point for virtually any copper solvent extraction reagent or combination of reagents under a wide variety of conditions. The equilibrium strip points for several well known commercial copper solvent extraction reagents are given as a function of reagent concentration, the copper and acid concentration of the strip aqueous, and the temperature. It is shown that the equilibrium strip point is not a straight line function of reagent concentration and that the equilibrium strip point increases with an increase in temperature. Copper extraction also increases as the temperature increases.

  9. BIOMONITORING OF AMBIENT CONCENTRATIONS OF CADMIUM,COPPER, LEAD AND ZINC IN THE COASTAL WETLAND WATER BY USING GILLS OF THE GREEN- LIPPED MUSSEL PERNA VIRIDIS

    Institute of Scientific and Technical Information of China (English)

    Chee Kong Yap; Ahmad Ismail; Abdul Rahim Ismail; Soon Guan Tan

    2006-01-01

    The distribution and concentrations of Cd, Cu, Pb and Zn were determined in the gills and remaining soft tissues of Perna viridis collected from 12 geographical sites ( 10 from the west and 2 from the east coastal waters) of Peninsular Malaysia. All samples showed that the levels of Cd, Pb and Zn were generally higher in the gill than those in the remaining soft tissues. These results could be due to the fact that gills are the first organ of metal accumulation and larger surface area with mucus sheets in the organ. Since the mussel gill is a better accumulator of Cd, Pb and Zn of ambient seawater than remaining soft tissue, it is a potential indicator of ambient levels of dissolved metals in the ambient seawater. However, further validations based on laboratory conditions are needed.

  10. Pesticidal copper (I) oxide: environmental fate and aquatic toxicity.

    Science.gov (United States)

    Kiaune, Lina; Singhasemanon, Nan

    2011-01-01

    Besides being a naturally occurring element and an essential micronutrient, copper is used as a pesticide, but at generally higher concentrations. Copper, unlike organic pesticides, does not degrade, but rather enters a complex biogeochemical cycle. In the water column, copper can exist bound to both organic and inorganic species and as free or hydrated copper ions. Water column chemistry affects copper speciation and bioavailability. In all water types (saltwater, brackish water, and freshwater), organic ligands in the water column can sequester the majority of dissolved copper, and therefore, organic ligands play the largest role in copper bioavailability. In freshwater, however, the geochemistry of a particular location, including water column characteristics such as water hardness and pH, is a significant factor that can increase copper bioavailability and toxicity. In most cases, organic ligand concentrations greatly exceed copper ion concentrations in the water column and therefore provide a large buffering capacity. Hence, copper bioavailability can be grossly overestimated if it is based on total dissolved copper (TDCu) concentrations alone. Other factors that influence copper concentrations include location in the water column, season, temperature, depth, and level of dissolved oxygen. For example, concentrations of bioavailable copper may be significantly higher in the bottom waters and sediment pore waters, where organic ligands degrade much faster and dissolved copper is constantly resuspended and recycled into the aquatic system. Aquatic species differ greatly in their sensitivity to copper. Some animals, like mollusks, can tolerate high concentrations of the metal, while others are adversely affected by very low concentrations of copper. Emerging evidence shows that very low, sublethal copper levels can adversely affect the sense of smell and behavior of fish. The developmental stage of the fish at the time of copper exposure is critical to the

  11. Liquidus slopes of impurities in ITS-90 fixed points from the mercury point to the copper point in the low concentration limit

    Science.gov (United States)

    Pearce, Jonathan V.; Gisby, John A.; Steur, Peter P. M.

    2016-08-01

    A knowledge of the effect of impurities at the level of parts per million on the freezing temperature of very pure metals is essential for realisation of ITS-90 fixed points. New information has become available for use with the thermodynamic modelling software MTDATA, permitting calculation of liquidus slopes, in the low concentration limit, of a wider range of binary alloy systems than was previously possible. In total, calculated values for 536 binary systems are given. In addition, new experimental determinations of phase diagrams, in the low impurity concentration limit, have recently appeared. All available data have been combined to provide a comprehensive set of liquidus slopes for impurities in ITS-90 metal fixed points. In total, liquidus slopes for 838 systems are tabulated for the fixed points Hg, Ga, In, Sn, Zn, Al, Ag, Au, and Cu. It is shown that the value of the liquidus slope as a function of impurity element atomic number can be approximated using a simple formula, and good qualitative agreement with the existing data is observed for the fixed points Al, Ag, Au and Cu, but curiously the formula is not applicable to the fixed points Hg, Ga, In, Sn, and Zn. Some discussion is made concerning the influence of oxygen on the liquidus slopes, and some calculations using MTDATA are discussed. The BIPM’s consultative committee for thermometry has long recognised that the sum of individual estimates method is the ideal approach for assessing uncertainties due to impurities, but the community has been largely powerless to use the model due to lack of data. Here, not only is data provided, but a simple model is given to enable known thermophysical data to be used directly to estimate impurity effects for a large fraction of the ITS-90 fixed points.

  12. Antwerp Copper Plates

    DEFF Research Database (Denmark)

    Wadum, Jørgen

    1999-01-01

    In addition to presenting a short history of copper paintings, topics detail artists’ materials and techniques, as well as aspects of the copper industry, including mining, preparation and trade routes.......In addition to presenting a short history of copper paintings, topics detail artists’ materials and techniques, as well as aspects of the copper industry, including mining, preparation and trade routes....

  13. Cloud Interactions

    Science.gov (United States)

    2004-01-01

    [figure removed for brevity, see original site] Released 1 July 2004 The atmosphere of Mars is a dynamic system. Water-ice clouds, fog, and hazes can make imaging the surface from space difficult. Dust storms can grow from local disturbances to global sizes, through which imaging is impossible. Seasonal temperature changes are the usual drivers in cloud and dust storm development and growth. Eons of atmospheric dust storm activity has left its mark on the surface of Mars. Dust carried aloft by the wind has settled out on every available surface; sand dunes have been created and moved by centuries of wind; and the effect of continual sand-blasting has modified many regions of Mars, creating yardangs and other unusual surface forms. This image was acquired during mid-spring near the North Pole. The linear water-ice clouds are now regional in extent and often interact with neighboring cloud system, as seen in this image. The bottom of the image shows how the interaction can destroy the linear nature. While the surface is still visible through most of the clouds, there is evidence that dust is also starting to enter the atmosphere. Image information: VIS instrument. Latitude 68.4, Longitude 258.8 East (101.2 West). 38 meter/pixel resolution. Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time. NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara

  14. Design of Oxygen Concentration Detection Based on WiFi and Cloud Intelligent%基于WiFi的云智能血氧仪设计研究∗

    Institute of Scientific and Technical Information of China (English)

    翟永前; 奚吉; 赵力

    2015-01-01

    Combined with the latest developments in communications technology,this paper presented a detection system of oxygen concentration based on WiFi and intelligent cloud. The system utilizes cloud computing to fulfill fuzzy neural, and network to achieve the ant colony optimization algorithm,which not only reduces the complexity of the perceived end hardware and software design,and effectively improves the oxygen detection accuracy,real-time tracking and more condu-cive to long-term maintenance of health data oxygen. Experimental Results shows the design is safe and reliable,consist-ent with the development of intelligent health care,so it has good application and promotional value.%结合通信技术最新发展,本文通过引入云智能,提出了一种基于WiFi的云智能血氧浓度检测系统。该系统利用云计算实现了模糊神经网络的蚁群优化算法,不仅降低了感知端的软硬件设计的复杂度,而且有效提高了血氧检测精度,更有利于血氧健康数据的实时跟踪和长期维护。实验结果表明,本文提出的设计安全可靠,符合智能医疗的发展方向,因此具有较好的应用及推广价值。

  15. Copper and copper proteins in Parkinson's disease.

    Science.gov (United States)

    Montes, Sergio; Rivera-Mancia, Susana; Diaz-Ruiz, Araceli; Tristan-Lopez, Luis; Rios, Camilo

    2014-01-01

    Copper is a transition metal that has been linked to pathological and beneficial effects in neurodegenerative diseases. In Parkinson's disease, free copper is related to increased oxidative stress, alpha-synuclein oligomerization, and Lewy body formation. Decreased copper along with increased iron has been found in substantia nigra and caudate nucleus of Parkinson's disease patients. Copper influences iron content in the brain through ferroxidase ceruloplasmin activity; therefore decreased protein-bound copper in brain may enhance iron accumulation and the associated oxidative stress. The function of other copper-binding proteins such as Cu/Zn-SOD and metallothioneins is also beneficial to prevent neurodegeneration. Copper may regulate neurotransmission since it is released after neuronal stimulus and the metal is able to modulate the function of NMDA and GABA A receptors. Some of the proteins involved in copper transport are the transporters CTR1, ATP7A, and ATP7B and the chaperone ATOX1. There is limited information about the role of those biomolecules in the pathophysiology of Parkinson's disease; for instance, it is known that CTR1 is decreased in substantia nigra pars compacta in Parkinson's disease and that a mutation in ATP7B could be associated with Parkinson's disease. Regarding copper-related therapies, copper supplementation can represent a plausible alternative, while copper chelation may even aggravate the pathology.

  16. Proline improves copper tolerance in chickpea (Cicer arietinum).

    Science.gov (United States)

    Singh, Vijeta; Bhatt, Indu; Aggarwal, Anjali; Tripathi, Bhumi Nath; Munjal, Ashok Kumar; Sharma, Vinay

    2010-09-01

    The present study suggests the involvement of proline in copper tolerance of four genotypes of Cicer arietinum (chickpea). Based on the data of tolerance index and lipid peroxidation, the order for copper tolerance was as follows: RSG 888 > CSG 144 > CSG 104 > RSG 44 in the selected genotypes. The basis of differential copper tolerance in chickpea genotypes was characterized by analyzing, antioxidant enzymes (superoxide dismutase, ascorbated peroxidase and catalase), phytochelatins, copper uptake, and proline accumulation. Chickpea genotypes showed stimulated superoxide dismutase activity at all tested concentrations of copper, but H(2)O(2) decomposing enzymes especially; ascorbate peroxidase did not increase with 25 and 50 microM copper treatments. Catalase activity, however, increased at lower copper concentrations but failed to stimulate at 50 microM copper. Such divergence in responses of these enzymes minimizes their importance in protecting chickpea against copper stress. The sensitive genotypes showed greater enhancement of phytochelatins than that of tolerant genotypes. Hence, the possibility of phytochelatins in improving copper tolerance in the test plant is also excluded. Interestingly, the order of proline accumulation in the chickpea genotypes (RSG 888 > CSG 144 > CSG 104 > RSG 44) was exactly similar to the order of copper tolerance. Based on hyperaccumulation of proline in tolerant genotype (RSG 44) and the reduction and improvement of lipid peroxidation and tolerance index, respectively, by proline pretreatment, we conclude that hyperaccumulation of proline improves the copper tolerance in chickpea.

  17. Abnormal Copper Homeostasis: Mechanisms and Roles in Neurodegeneration

    Directory of Open Access Journals (Sweden)

    Mario Manto

    2014-06-01

    Full Text Available As a cofactor of proteins and enzymes involved in critical molecular pathways in mammals and low eukaryotes, copper is a transition metal essential for life. The intra-cellular and extra-cellular metabolism of copper is under tight control, in order to maintain free copper concentrations at very low levels. Copper is a critical element for major neuronal functions, and the central nervous system is a major target of disorders of copper metabolism. Both the accumulation of copper and copper deficiency are associated with brain dysfunction. The redox capacities of free copper, its ability to trigger the production of reactive oxygen species and the close relationships with the regulation of iron and zinc are remarkable features. Major advances in our understanding of the relationships between copper, neuronal functions and neurodegeneration have occurred these last two decades. The metabolism of copper and the current knowledge on the consequences of copper dysregulation on brain disorders are reviewed, with a focus on neurodegenerative diseases, such as Wilson’s disease, Alzheimer’s disease and Parkinson’s disease. In vitro studies, in vivo experiments and evidence from clinical observations of the neurotoxic effects of copper provide the basis for future therapies targeting copper homeostasis.

  18. Annual changes of iron,manganese,zinc and copper concentrations in both types of citrus fruit%两结实类型柑橘果实铁锰锌铜含量的年周期变化

    Institute of Scientific and Technical Information of China (English)

    肖家欣; 彭抒昂

    2008-01-01

    Annual changes in concentrations of iron(Fe),manganese(Mn),zinc(Zn)and copper(Cu)were measured in whole fruits from parthenocarpic Kamei satsuma mandarin(Citrus unshiu)and self-pollinated Egan 1 tangerine(C.reticulata)trees. The results were showed as follows:(1)Zn and Cu concentrations in the ovary of Kamei were relatively high before flowering and at full bloom,and decreased after flowering,whereas those of Egan 1 decreased obviously and were relatively low at full bloom,thereafter significant increases were observed. There were no significant differences in changes of Fe and Mn concentrations in the ovaries(fruitlets)between the two cultivars,which presented similarly decreasing trends after flowering. (2)Fe,Mn,Zn and Cu concentrations were relatively high in whole fruits of both cultivars during young fruit development,and decreased remarkably during early fruit enlargement(drought spell),whereas increased dramatically at the middle stage of fruit enlargement,thereafter decreased gradually. Dynamics of micronutrients concentrations in developing fruit and their possible relation with fruits development is discussed herein.%对单性结实的龟井温州蜜柑和自花授粉结实的鄂柑1号柑橘果实的铁、锰、锌和铜含量的年周期变化进行了测定.结果表明:(1)龟井子房的锌和铜含量在花前至花期居较高,花后趋下降,而鄂柑1号对应值在花期出现明显下降并居较低,花后却有一明显上升;两品种子房(幼果)的铁和锰含量变化却无明显差异,花后呈类似的下降趋势.(2)幼果阶段的果实铁、锰、锌和铜含量均居较高,在果实膨大初期(干旱期)均出现一明显下降,而在果实膨大中期却出现显著上升,之后又趋下降.本文还对果实发育中的微量元素含量动态及其与果实发育之间的关系进行了讨论.

  19. Comparative results of copper flotation from smelter slag and granulated smelter slag

    OpenAIRE

    Milanović, Dragan; Stanujkić, Dragiša; Ignjatović, Miroslav R.

    2013-01-01

    Smelter slag is obtained in the process of metallurgical converting of copper concentrate in the Smelter Plant in Bor, Serbia. Today, the reserves of this material are evaluated at about more of a year, with the average copper content of 0.6-0.9%. Production of copper concentrate by flotation of smelter slag has started in 2001. Flotation concentrate goes to the Copper Smelter once more for production of copper cathodes and the rough flotation tailings go to the flotation tailing dump. Copper...

  20. Diffusion of copper in porous silicon

    Energy Technology Data Exchange (ETDEWEB)

    Andsager, D.; Hetrick, J.M.; Hilliard, J.; Nayfeh, M.H. [Department of Physics, 1110 West Green Street, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States)

    1995-05-01

    We present a study on the nature of diffusion of copper in {ital p}-type porous silicon. The diffusion of evaporated copper in porous silicon and deposition of metal ions in aqueous solution through the porous network was measured by monitoring the metal concentration depth profile as a function of time using Auger electron spectroscopy. We observed that increasing metal penetration from copper evaporated samples correlates with quenching of photoluminescence, in agreement with previous ion quenching results. We extracted a diffusion coefficient from Auger concentration depth profiles which was seven orders of magnitude lower than that expected for diffusion of copper in bulk crystalline Si at room temperature. Deposition of ionic species cannot be characterized as a simple diffusion process. The observed deposition rates were strongly dependent on the solution concentration.

  1. EFFCTS OF pH AND Cl- CONCENTRATION ON THE CORROSION BEHAVIOR OF COPPER IN BORIC ACID BUFFER SOLUTION%硼酸缓冲溶液中pH值和Cl-浓度对Cu腐蚀行为的影响

    Institute of Scientific and Technical Information of China (English)

    王长罡; 董俊华; 柯伟; 陈楠

    2011-01-01

    The strategy for disposal of high-level radioactive waste in china is to enclose the spent nuclear fuel in sealed metal canisters which are embedded in bentonite clay hundreds meters deep in the bed-rock. The choice of container material depends largely on the redox conditions and the aqueous environment of the repository. One of the choices for the fabrication of waste canisters is copper, for it is thermodynamically stable under the saline, anoxic conditions over the large majority of the container lifetime. For this advantage, some other countries (Canada, Sweden) have selected copper as the material of nuclear waste container. However, in the early aerobic phase of the geological disposal the corrosion of copper could take place, and the corrosion behavior of copper would be influenced by the complex chemical conditions of groundwater markedly. Regularly, in atmosphere environment the semiconductor passive film which is constructed by Cu2O would generate on the surface of copper. On the one hand, the Cu2O film could protect copper from corrosion. On the other hand, the formation of Cu2O film is necessary to maintain the propagation of crack during the stress corrosion cracking. Therefore, the study of the effect of water chemistry conditions on the stability of Cu2O passive film makes great sense for the general corrosion and stress corrosion cracking of copper. For copper and copper alloy, Cl- is a highly aggressive ion. Lots of cases of failure and corrosion behavior of copper and copper alloy in Cl- environment have been studied. The immersion of Cl- would affect the semiconductor properties of Cu2O, therefore, we focused on the effect of pH and Cl- concentration on the corrosion behavior and semiconductor properties of Cu2O in this paper. The polarization behavior of Cu electrodes and the stability of passive film Cu2O in boric acid buffer solution have been investigated respectively by potentiodynamic polarization, electrochemical impedance spectroscopy

  2. Characterization of copper-resistant rhizosphere bacteria from Avena sativa and Plantago lanceolata for copper bioreduction and biosorption.

    Science.gov (United States)

    Andreazza, Robson; Okeke, Benedict C; Pieniz, Simone; Camargo, Flávio A O

    2012-04-01

    Copper is a toxic heavy metal widely used to microbial control especially in agriculture. Consequently, high concentrations of copper residues remain in soils selecting copper-resistant organisms. In vineyards, copper is routinely used for fungi control. This work was undertaken to study copper resistance by rhizosphere microorganisms from two plants (Avena sativa L. and Plantago lanceolata L.) common in vineyard soils. Eleven rhizosphere microorganisms were isolated, and four displayed high resistance to copper. The isolates were identified by 16S rRNA gene sequence analysis as Pseudomonas putida (A1), Stenotrophomonas maltophilia (A2) and Acinetobacter sp. (A6), isolated from Avena sativa rhizosphere, and Acinetobacter sp. (T5), isolated from Plantago lanceolata rhizosphere. The isolates displayed high copper resistance in the temperature range from 25°C to 35°C and pH in the range from 5.0 to 9.0. Pseudomonas putida A1 resisted as much as 1,000 mg L(-1) of copper. The isolates showed similar behavior on copper removal from liquid medium, with a bioremoval rate of 30% at 500 mg L(-1) after 24 h of growth. Speciation of copper revealed high copper biotransformation, reducing Cu(II) to Cu(I), capacity. Results indicate that our isolates are potential agents for copper bioremoval and bacterial stimulation of copper biosorption by Avena sativa and Plantago lanceolata.

  3. Copper and selenium supplementation in the diet of Brangus steers on the nutritional characteristics of meat

    Directory of Open Access Journals (Sweden)

    Arlindo Saran Netto

    2013-01-01

    Full Text Available Twenty-eight Brangus cattle were used to determine the effect of copper and selenium supplementation on the carcass characteristics, fatty acid composition of the longissimus dorsi muscle and on the copper and selenium concentrations in the liver. The treatments were: no supplementation of copper or selenium; 2 mg Se/kg DM as sodium selenite; 40 mg Cu/kg DM as copper sulfate; and 2 mg Se/kg DM as sodium selenite and 40 mg Cu/kg DM as copper sulfate. The fat thickness, rib eye area and fatty acid composition of the longissimus dorsi muscle were not affected by treatments. There was no effect on carcass yield and cooling loss with the supplementation of copper, selenium or selenium × copper in the levels studied. For the ether extract concentration in the longissimus dorsi muscle, no differences were found according to the treatments with selenium, copper or selenium × copper. The treatments with selenium and selenium × copper showed higher selenium concentrations in the liver than the control and copper treatments. For the copper concentration in the liver, the copper and selenium × copper treatments showed higher values than the control and selenium treatments. Despite the little effect on the meat composition, the results of this experiment demonstrate no interaction between selenium and copper in the levels studied.

  4. In situ exhaust cloud measurements. [particle size distribution and cloud physics of rocket exhaust clouds

    Science.gov (United States)

    Wornom, D.

    1980-01-01

    Airborne in situ exhaust cloud measurements were conducted to obtain definitions of cloud particle size range, Cl2 content, and HCl partitioning. Particle size distribution data and Cl2 measurements were made during the May, August, and September 1977 Titan launches. The measurements of three basic effluents - HCl, NO sub X, and particles - against minutes after launch are plotted. The maximum observed HCl concentration to the maximum Cl2 concentration are compared and the ratios of the Cl2 to the HCl is calculated.

  5. Martian Clouds

    Science.gov (United States)

    2004-01-01

    [figure removed for brevity, see original site] Released 28 June 2004 The atmosphere of Mars is a dynamic system. Water-ice clouds, fog, and hazes can make imaging the surface from space difficult. Dust storms can grow from local disturbances to global sizes, through which imaging is impossible. Seasonal temperature changes are the usual drivers in cloud and dust storm development and growth. Eons of atmospheric dust storm activity has left its mark on the surface of Mars. Dust carried aloft by the wind has settled out on every available surface; sand dunes have been created and moved by centuries of wind; and the effect of continual sand-blasting has modified many regions of Mars, creating yardangs and other unusual surface forms. This image was acquired during early spring near the North Pole. The linear 'ripples' are transparent water-ice clouds. This linear form is typical for polar clouds. The black regions on the margins of this image are areas of saturation caused by the build up of scattered light from the bright polar material during the long image exposure. Image information: VIS instrument. Latitude 68.1, Longitude 147.9 East (212.1 West). 38 meter/pixel resolution. Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time. NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip

  6. Solar thermal extraction of copper from sulfides

    Energy Technology Data Exchange (ETDEWEB)

    Winkel, L.; Guesdon, C.; Sturzenegger, M.

    2003-03-01

    With the aim to develop a solar-driven process for the extraction of copper from sulfide concentrates re-search on the decomposition of copper sulfides under inert atmospheres has been initiated. Thermogravimetric measurements on chalcocite (Cu{sub 2}S) revealed that copper is formed already at 1823 K. Chalcopyrite (CuFeS{sub 2}) also disintegrates at this temperature, although at a lower rate. Copper and iron have been identified in the solid residue. The results confirm the feasibility of copper extraction by direct decomposition of sulfides under atmospheric pressure. The decomposition under inert atmosphere prevents generation of SO{sub 2}, and is beneficial to the removal of volatile impurities. Chemical equilibrium calculations for CuFeS{sub 2} contaminated with enargite (Cu{sub 3}AsS{sub 4}) have shown that the absence of an oxidic slag allows for a complete evaporation of arsenic and subsequent separation. (author)

  7. EDITORIAL: Focus on Cloud Physics FOCUS ON CLOUD PHYSICS

    Science.gov (United States)

    Falkovich, Gregory; Malinowski, Szymon P.

    2008-07-01

    Cloud physics has for a long time been an important segment of atmospheric science. It is common knowledge that clouds are crucial for our understanding of weather and climate. Clouds are also interesting by themselves (not to mention that they are beautiful). Complexity is hidden behind the common picture of these beautiful and interesting objects. The typical school textbook definition that a cloud is 'a set of droplets or particles suspended in the atmosphere' is not adequate. Clouds are complicated phenomena in which dynamics, turbulence, microphysics, thermodynamics and radiative transfer interact on a wide range of scales, from sub-micron to kilometres. Some of these interactions are subtle and others are more straightforward. Large and small-scale motions lead to activation of cloud condensation nuclei, condensational growth and collisions; small changes in composition and concentration of atmospheric aerosol lead to significant differences in radiative properties of the clouds and influence rainfall formation. It is justified to look at a cloud as a composite, nonlinear system which involves many interactions and feedback. This system is actively linked into a web of atmospheric, oceanic and even cosmic interactions. Due to the complexity of the cloud system, present-day descriptions of clouds suffer from simplifications, inadequate parameterizations, and omissions. Sometimes the most fundamental physics hidden behind these simplifications and parameterizations is not known, and a wide scope of view can sometimes prevent a 'microscopic', deep insight into the detail. Only the expertise offered by scientists focused on particular elementary processes involved in this complicated pattern of interactions allows us to shape elements of the puzzle from which a general picture of clouds can be created. To be useful, every element of the puzzle must be shaped precisely. This often creates problems in communication between the sciences responsible for shaping

  8. Cloud Computing (4)

    Institute of Scientific and Technical Information of China (English)

    Wang Bai; Xu Liutong

    2010-01-01

    @@ 8 Case Study Cloud computing is still a new phenomenon. Although many IT giants are developing their own cloud computing infrastructures,platforms, software, and services, few have really succeeded in becoming cloud computing providers.

  9. Blue skies for CLOUD

    CERN Multimedia

    2006-01-01

    Through the recently approved CLOUD experiment, CERN will soon be contributing to climate research. Tests are being performed on the first prototype of CLOUD, an experiment designed to assess cosmic radiation influence on cloud formation.

  10. Extracting copper from copper oxide ore by a zwitterionic reagent and dissolution kinetics

    Institute of Scientific and Technical Information of China (English)

    Jiu-shuai Deng; Shu-ming Wen; Jian-ying Deng; Dan-dan Wu

    2015-01-01

    Sulfamic acid (SA), which possesses a zwitterionic structure, was applied as a leaching reagent for the first time for extracting copper from copper oxide ore. The effects of reaction time, temperature, particle size, reagent concentration, and stirring speed on this leach-ing were studied. The dissolution kinetics of malachite was illustrated with a three-dimensional diffusion model. A novel leaching effect of SA on malachite was eventually demonstrated. The leaching rate increased with decreasing particle size and increasing concentration, reac-tion temperature and stirring speed. The activation energy for SA leaching malachite was 33.23 kJ/mol. Furthermore, the effectiveness of SA as a new reagent for extracting copper from copper oxide ore was confirmed by experiment. This approach may provide a solution suitable for subsequent electrowinning. In addition, results reported herein may provide basic data that enable the leaching of other carbonate miner-als of copper, zinc, cobalt and so on in an SA system.

  11. On Web Services Based Cloud Interoperability

    Directory of Open Access Journals (Sweden)

    Reeta Sony A.L

    2012-09-01

    Full Text Available Cloud Computing is a paradigm shift in the field of Computing. It is moving at an incredible fast pace and one of the fastest evolving domains of computer science today. It consist set of technology and service models that concentrates on the internet base use and delivery of IT applications, processing capability, storage and memory space. There is a shift from the traditional in-house servers and applications to the next generation of cloud computing applications. With many of the computer giants like Google, Microsoft, etc. entering into the cloud computing arena, there will be thousands of applications running on the cloud. There are several cloud environments available in the market today which support a huge consumer-base. Eventually this will lead to a multitude of standards, technologies and products being provided on the cloud. Consumers will need certain degrees of flexibility to use the cloud application/services of their choice and at the same time will need these applications/services to communicate with each other. This paper emphasizes cloud computing and provides a solution to achieve Interoperability, which is in the form of Web Services. The paper will also provide a Live Case Study where interoperability comes into play - Connecting Google App Engine and Microsoft Windows Azure Platform, two of the leading Cloud Platforms available today. GAE and WAP are two Cloud Frameworks which have very little in common, making interoperability an absolute necessary.

  12. Mesophilic leaching of copper sulphide sludge

    Directory of Open Access Journals (Sweden)

    VLADIMIR B. CVETKOVSKI

    2009-02-01

    Full Text Available Copper was precipitated using a sodium sulphide solution as the precipitation agent from an acid solution containing 17 g/l copper and 350 g/l sulphuric acid. The particle size of nearly 1 µm in the sulphide sludge sample was detected by optical microscopy. Based on chemical and X-ray diffraction analyses, covellite was detected as the major sulphide mineral. The batch bioleach amenability test was performed at 32 °C on the Tk31 mine mesophilic mixed culture using a residence time of 28 days. The dissolution of copper sulphide by direct catalytic leaching of the sulphides with bacteria attached to the particles was found to be worthy, although a small quantity of ferrous ions had to be added to raise the activity of the bacteria and the redox potential of the culture medium. Throughout the 22-day period of the bioleach test, copper recovery based on residue analysis indicated a copper extraction of 95 %, with copper concentration in the bioleach solution of 15 g/l. The slope of the straight line tangential to the exponential part of the extraction curve gave a copper solubilisation rate of 1.1 g/l per day. This suggests that a copper extraction of 95 % for the period of bioleach test of 13.6 days may be attained in a three-stage bioreactor system.

  13. Cloud-Top Entrainment in Stratocumulus Clouds

    Science.gov (United States)

    Mellado, Juan Pedro

    2017-01-01

    Cloud entrainment, the mixing between cloudy and clear air at the boundary of clouds, constitutes one paradigm for the relevance of small scales in the Earth system: By regulating cloud lifetimes, meter- and submeter-scale processes at cloud boundaries can influence planetary-scale properties. Understanding cloud entrainment is difficult given the complexity and diversity of the associated phenomena, which include turbulence entrainment within a stratified medium, convective instabilities driven by radiative and evaporative cooling, shear instabilities, and cloud microphysics. Obtaining accurate data at the required small scales is also challenging, for both simulations and measurements. During the past few decades, however, high-resolution simulations and measurements have greatly advanced our understanding of the main mechanisms controlling cloud entrainment. This article reviews some of these advances, focusing on stratocumulus clouds, and indicates remaining challenges.

  14. Cloud condensation nuclei as a modulator of ice processes in Arctic mixed-phase clouds

    Directory of Open Access Journals (Sweden)

    S. Lance

    2011-02-01

    Full Text Available We propose that cloud condensation nuclei (CCN concentrations are important for modulating ice formation of Arctic mixed-phase clouds, through modification of the droplet size distribution. Aircraft observations from the Aerosol, Radiation, and Cloud Processes affecting Arctic Climate (ARCPAC study in northern Alaska in April 2008 allow for identification and characterization of both aerosol and trace gas pollutants, which are then compared with cloud microphysical properties. Consistent with previous studies, we find that the concentration of precipitating ice particles (>400 μm is correlated with the concentration of large droplets (>30 μm. We are further able to link the observed microphysical conditions to aerosol pollution, originating mainly from long range transport of biomass burning emissions. The case studies demonstrate that polluted mixed-phase clouds have narrower droplet size distributions and contain 1–2 orders of magnitude fewer precipitating ice particles than clean clouds at the same temperature. This suggests an aerosol indirect effect leading to greater cloud lifetime, greater cloud emissivity, and reduced precipitation. This result is opposite to the glaciation indirect effect, whereby polluted clouds are expected to precipitate more readily due to an increase in the concentration of particles acting as IN.

  15. Cloud condensation nuclei as a modulator of ice processes in Arctic mixed-phase clouds

    Science.gov (United States)

    Lance, S.; Shupe, M. D.; Feingold, G.; Brock, C. A.; Cozic, J.; Holloway, J. S.; Moore, R. H.; Nenes, A.; Schwarz, J. P.; Spackman, J. R.; Froyd, K. D.; Murphy, D. M.; Brioude, J.; Cooper, O. R.; Stohl, A.; Burkhart, J. F.

    2011-08-01

    We propose that cloud condensation nuclei (CCN) concentrations are important for modulating ice formation of Arctic mixed-phase clouds, through modification of the droplet size distribution. Aircraft observations from the Aerosol, Radiation, and Cloud Processes affecting Arctic Climate (ARCPAC) study in northern Alaska in April 2008 allow for identification and characterization of both aerosol and trace gas pollutants, which are then compared with cloud microphysical properties. Consistent with previous studies, we find that the concentration of precipitating ice particles (>400 μm) is correlated with the concentration of large droplets (>30 μm). We are further able to link the observed microphysical conditions to aerosol pollution, originating mainly from long range transport of biomass burning emissions. The case studies demonstrate that polluted mixed-phase clouds have narrower droplet size distributions and contain 1-2 orders of magnitude fewer precipitating ice particles than clean clouds at the same temperature. This suggests an aerosol indirect effect leading to greater cloud lifetime, greater cloud emissivity, and reduced precipitation. This result is opposite to the glaciation indirect effect, whereby polluted clouds are expected to precipitate more readily due to an increase in the concentration of particles acting as ice nuclei.

  16. Cloud condensation nuclei as a modulator of ice processes in Arctic mixed-phase clouds

    Directory of Open Access Journals (Sweden)

    S. Lance

    2011-08-01

    Full Text Available We propose that cloud condensation nuclei (CCN concentrations are important for modulating ice formation of Arctic mixed-phase clouds, through modification of the droplet size distribution. Aircraft observations from the Aerosol, Radiation, and Cloud Processes affecting Arctic Climate (ARCPAC study in northern Alaska in April 2008 allow for identification and characterization of both aerosol and trace gas pollutants, which are then compared with cloud microphysical properties. Consistent with previous studies, we find that the concentration of precipitating ice particles (>400 μm is correlated with the concentration of large droplets (>30 μm. We are further able to link the observed microphysical conditions to aerosol pollution, originating mainly from long range transport of biomass burning emissions. The case studies demonstrate that polluted mixed-phase clouds have narrower droplet size distributions and contain 1–2 orders of magnitude fewer precipitating ice particles than clean clouds at the same temperature. This suggests an aerosol indirect effect leading to greater cloud lifetime, greater cloud emissivity, and reduced precipitation. This result is opposite to the glaciation indirect effect, whereby polluted clouds are expected to precipitate more readily due to an increase in the concentration of particles acting as ice nuclei.

  17. Potassium sorbate-A new aqueous copper corrosion inhibitor

    Energy Technology Data Exchange (ETDEWEB)

    Abelev, Esta [Department of Materials Engineering, Technion-Israel Institute of Technology, Haifa 32000 (Israel); Starosvetsky, David [Department of Materials Engineering, Technion-Israel Institute of Technology, Haifa 32000 (Israel); Ein-Eli, Yair [Department of Materials Engineering, Technion-Israel Institute of Technology, Haifa 32000 (Israel)]. E-mail: eineli@tx.technion.ac.il

    2007-01-01

    This work presents the novel nature of 2,4-hexadienoic acid potassium salt (potassium sorbate (KCH{sub 3}CH=CHCH=CHCO{sub 2})) as an effective copper aqueous corrosion inhibitor. The influence of pH and potassium sorbate concentration on copper corrosion in aerated sulfate and chloride solutions is reported. Degree of copper protection was found to increase with an increase in potassium sorbate concentration; an optimum concentration of this inhibitor in sulfate solutions was found to be 10 g/L. Copper is highly resistant to corrosion attacks by chloride ions in the presence of potassium sorbate. X-ray photoelectron spectroscopy (XPS) studies suggest that copper protection is achieved via the formation of a mixed layer of cuprous oxide, cupric hydroxide and copper(II)-sorbate at the metal surface.

  18. Silicon Photonics Cloud (SiCloud)

    DEFF Research Database (Denmark)

    DeVore, P. T. S.; Jiang, Y.; Lynch, M.;

    2015-01-01

    Silicon Photonics Cloud (SiCloud.org) is the first silicon photonics interactive web tool. Here we report new features of this tool including mode propagation parameters and mode distribution galleries for user specified waveguide dimensions and wavelengths.......Silicon Photonics Cloud (SiCloud.org) is the first silicon photonics interactive web tool. Here we report new features of this tool including mode propagation parameters and mode distribution galleries for user specified waveguide dimensions and wavelengths....

  19. Low Hepatic Tissue Copper in Pediatric Nonalcoholic Fatty Liver Disease.

    Science.gov (United States)

    Mendoza, Michael; Caltharp, Shelley; Song, Ming; Collin, Lindsay; Konomi, Juna V; McClain, Craig J; Vos, Miriam B

    2017-07-01

    Animal models and studies in adults have demonstrated that copper restriction increases severity of liver injury in nonalcoholic fatty liver disease (NAFLD). This has not been studied in children. We aimed to determine if lower tissue copper is associated with increased NAFLD severity in children. This was a retrospective study of pediatric patients who had a liver biopsy including a hepatic copper quantitation. The primary outcome compared hepatic copper concentration in NAFLD versus non-NAFLD. Secondary outcomes compared hepatic copper levels against steatosis, fibrosis, lobular inflammation, balloon degeneration, and NAFLD activity score (NAS). The study analysis included 150 pediatric subjects (102 with NAFLD and 48 non-NAFLD). After adjusting for age, body mass index z score, gamma glutamyl transferase, alanine aminotransferase, and total bilirubin, NAFLD subjects had lower levels of hepatic copper than non-NAFLD (P = 0.005). In addition, tissue copper concentration decreased as steatosis severity increased (P < 0.001). Copper levels were not associated with degree of fibrosis, lobular inflammation, portal inflammation, or balloon degeneration. In this cohort of pediatric subjects with NAFLD, we observed decreased tissue copper levels in subjects with NAFLD when compared with non-NAFLD subjects. In addition, tissue copper levels were lower in subjects with nonalcoholic steatohepatitis, a more severe form of the disease, when compared with steatosis alone. Further studies are needed to explore the relationship between copper levels and NAFLD progression.

  20. Luminescent Colloidal Semiconductor Nanocrystals Containing Copper: Synthesis, Photophysics, and Applications.

    Science.gov (United States)

    Knowles, Kathryn E; Hartstein, Kimberly H; Kilburn, Troy B; Marchioro, Arianna; Nelson, Heidi D; Whitham, Patrick J; Gamelin, Daniel R

    2016-09-28

    Copper-doped semiconductors are classic phosphor materials that have been used in a variety of applications for many decades. Colloidal copper-doped semiconductor nanocrystals have recently attracted a great deal of interest because they combine the solution processability and spectral tunability of colloidal nanocrystals with the unique photoluminescence properties of copper-doped semiconductor phosphors. Although ternary and quaternary semiconductors containing copper, such as CuInS2 and Cu2ZnSnS4, have been studied primarily in the context of their photovoltaic applications, when synthesized as colloidal nanocrystals, these materials have photoluminescence properties that are remarkably similar to those of copper-doped semiconductor nanocrystals. This review focuses on the luminescent properties of colloidal copper-doped, copper-based, and related copper-containing semiconductor nanocrystals. Fundamental investigations into the luminescence of copper-containing colloidal nanocrystals are reviewed in the context of the well-established luminescence mechanisms of bulk copper-doped semiconductors and copper(I) molecular coordination complexes. The use of colloidal copper-containing nanocrystals in applications that take advantage of their luminescent properties, such as bioimaging, solid-state lighting, and luminescent solar concentrators, is also discussed.

  1. Automatic Cloud Bursting under FermiCloud

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Hao [Fermilab; Shangping, Ren [IIT; Garzoglio, Gabriele [Fermilab; Timm, Steven [Fermilab; Bernabeu, Gerard [Fermilab; Kim, Hyun Woo; Chadwick, Keith; Jang, Haengjin [KISTI, Daejeon; Noh, Seo-Young [KISTI, Daejeon

    1900-01-01

    Cloud computing is changing the infrastructure upon which scientific computing depends from supercomputers and distributed computing clusters to a more elastic cloud-based structure. The service-oriented focus and elasticity of clouds can not only facilitate technology needs of emerging business but also shorten response time and reduce operational costs of traditional scientific applications. Fermi National Accelerator Laboratory (Fermilab) is currently in the process of building its own private cloud, FermiCloud, which allows the existing grid infrastructure to use dynamically provisioned resources on FermiCloud to accommodate increased but dynamic computation demand from scientists in the domains of High Energy Physics (HEP) and other research areas. Cloud infrastructure also allows to increase a private cloud’s resource capacity through “bursting” by borrowing or renting resources from other community or commercial clouds when needed. This paper introduces a joint project on building a cloud federation to support HEP applications between Fermi National Accelerator Laboratory and Korea Institution of Science and Technology Information, with technical contributions from the Illinois Institute of Technology. In particular, this paper presents two recent accomplishments of the joint project: (a) cloud bursting automation and (b) load balancer. Automatic cloud bursting allows computer resources to be dynamically reconfigured to meet users’ demands. The load balance algorithm which the cloud bursting depends on decides when and where new resources need to be allocated. Our preliminary prototyping and experiments have shown promising success, yet, they also have opened new challenges to be studied

  2. Automatic Cloud Bursting under FermiCloud

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Hao [Fermilab; Shangping, Ren [IIT; Garzoglio, Gabriele [Fermilab; Timm, Steven [Fermilab; Bernabeu, Gerard [Fermilab; Kim, Hyun Woo; Chadwick, Keith; Jang, Haengjin [KISTI, Daejeon; Noh, Seo-Young [KISTI, Daejeon

    2013-01-01

    Cloud computing is changing the infrastructure upon which scientific computing depends from supercomputers and distributed computing clusters to a more elastic cloud-based structure. The service-oriented focus and elasticity of clouds can not only facilitate technology needs of emerging business but also shorten response time and reduce operational costs of traditional scientific applications. Fermi National Accelerator Laboratory (Fermilab) is currently in the process of building its own private cloud, FermiCloud, which allows the existing grid infrastructure to use dynamically provisioned resources on FermiCloud to accommodate increased but dynamic computation demand from scientists in the domains of High Energy Physics (HEP) and other research areas. Cloud infrastructure also allows to increase a private cloud’s resource capacity through “bursting” by borrowing or renting resources from other community or commercial clouds when needed. This paper introduces a joint project on building a cloud federation to support HEP applications between Fermi National Accelerator Laboratory and Korea Institution of Science and Technology Information, with technical contributions from the Illinois Institute of Technology. In particular, this paper presents two recent accomplishments of the joint project: (a) cloud bursting automation and (b) load balancer. Automatic cloud bursting allows computer resources to be dynamically reconfigured to meet users’ demands. The load balance algorithm which the cloud bursting depends on decides when and where new resources need to be allocated. Our preliminary prototyping and experiments have shown promising success, yet, they also have opened new challenges to be studied

  3. Prediction of cloud droplet number in a general circulation model

    Energy Technology Data Exchange (ETDEWEB)

    Ghan, S.J.; Leung, L.R. [Pacific Northwest National Lab., Richland, WA (United States)

    1996-04-01

    We have applied the Colorado State University Regional Atmospheric Modeling System (RAMS) bulk cloud microphysics parameterization to the treatment of stratiform clouds in the National Center for Atmospheric Research Community Climate Model (CCM2). The RAMS predicts mass concentrations of cloud water, cloud ice, rain and snow, and number concnetration of ice. We have introduced the droplet number conservation equation to predict droplet number and it`s dependence on aerosols.

  4. Produção de betacianina em erva-de-jacaré cultivada in vitro com diferentes concentrações de sulfato de cobre Betacyanin production in alligator weed, grown in vitro, with different concentrations of copper sulfate

    Directory of Open Access Journals (Sweden)

    Janieli Cristina Perotti

    2010-09-01

    Full Text Available A manipulação da concentração dos microelementos no meio de cultura representa uma boa estratégia para aumentar a produção de metabólitos secundários em cultura de tecidos. Este trabalho teve por objetivo demonstrar a influência do sulfato de cobre na produção de betacianina e na multiplicação de plantas de Alternanthera philoxeroides (erva-de-jacaré cultivadas in vitro. Segmentos nodais, obtidos de plantas pré-estabelecidas e após três subcultivos, foram inoculados em meio MS, com diferentes concentrações de CuSO4 (0; 25; 75; 125; 175; 200µM. O delineamento experimental utilizado foi inteiramente casualizado, com seis concentrações de CuSO4 e cinco repetições representadas por um frasco contendo quatro explantes. Os resultados foram submetidos à análise de variância, à regressão polinomial e a análises de correlação entre as variáveis morfológicas e a produção de betacianina. Concentrações acima de 75µM diminuíram a altura das plantas, o número de brotos e gemas e o crescimento radicular, enquanto que, na concentração de 125µM, houve a maior produção de massa fresca. A produção de betacianina aumentou 60% em relação ao controle com 175µM de CuSO4. Ocorreu crescimento das plantas em todas as concentrações de CuSO4 testadas, com exceção de 200µM, sendo esta considerada tóxica.The manipulation of concentration of trace elements in the culture medium represents a good strategy to increase the production of secondary metabolites in tissue culture. This study aimed to demonstrate the influence of copper sulphate in the production of betacyanin and the multiplication of plants of Alternanthera philoxeroides (alligator weed cultured in vitro. Nodal segments, obtained from plants pre-stablished and after three subcultures, were inoculated in basic MS with different concentrations of CuSO4 (0, 25, 75, 125, 175, 200µM. The results were subjected to analysis of variance, polynomial regression and

  5. The effect of copper and zinc at neutral and acidic pH on the general ...

    African Journals Online (AJOL)

    In general, at neutral pH copper and zinc caused blood acidosis, increases in ... as an adaptation to altered respiratory homeostasis caused by copper and zinc. ... concentrations usually caused blood alkalosis and decreases in white blood ...

  6. Exploratory cloud-resolving simulations of boundary-layer Arctic stratus clouds. Part I: Warm-season clouds

    Science.gov (United States)

    Olsson, Peter Q.; Harrington, Jerry Y.; Feingold, Graham; Cotton, William R.; Kreidenweis, Sonia M.

    Two-dimensional simulations of arctic stratus clouds (ASC) were conducted using a sophisticated cloud-resolving model with explicit microphysics and a two-stream radiative transfer model. The effects of varying cloud condensation nuclei (CCN) concentrations upon the subsequent cloud and its microphysical, radiative and dynamical structure were studied. In this study CCN concentrations were varied within the ranges found in warm-season arctic boundary layers (ABLs) to produce non-drizzling and weakly drizzling stratus decks. Experiments that included all model physics, no-drizzle, and no shortwave radiation were conducted to elucidate the effects of microphysics and radiation on the simulated stratus. Both simulations that did and that did not include the effects of drizzle showed that the higher CCN concentrations produced a cloud with larger reflectivity and absorptivity, but also produced eddies that were weaker than with lower CCN concentrations. Simulations that included the effects of drizzle showed a similar response to changes in CCN concentrations. Simulations with no drizzle produced more vigorous eddies than their drizzling counterparts because cooling due to evaporation below cloud tends to stabilize the ABL. The simulations without the effects of short-wave radiation produced very vigorous eddies that penetrated more deeply into the ABL. In this case, the simulation with higher CCN concentrations produced the most vigorous eddies. This resulted from a subtle interplay of microphysics, radiation, and dynamics.

  7. Thermal and IR studies on copper doped polyvinyl alcohol

    Indian Academy of Sciences (India)

    Ch Linga Raju; J L Rao; B C V Reddy; K Veera Brahmam

    2007-06-01

    5 mol% PVA : mol% Cu2+ polymer films were prepared by casting process. Thermal transitions and thermal degradation of samples with respect to copper concentration were studied by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA), respectively. Increase in glass transition temperature as a function of copper concentration shows a strong branching and steric effects in copper doped PVA complexes. Thermal degradation of films to an extent of 4–5% was found with an increase in copper content. FTIR spectrum of PVA doped Cu2+ ions indicate the presence of O–H, C–H, C=C and C–O groups.

  8. Bacterial leaching of discarded copper ores from Yongping, China

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The elementary and phase analysis of discarded copper ores from Yongping of China has been performed. The experiments of extracting copper from the discarded copper ores were done with the mixed bacteria obtained through a series of enrichment,separation, domestication and combination tests. The results show that in the process of bioleaching, the pH value rises at first and drops gradually. The Eh value keeps rising along with the time and the appropriate Eh value varying between 750 and 800 mV will benefit the bioleaching copper. The high concentration of ferric ions is detrimental to the bioleaching copper. The results of bioleaching copper are good. That is, the copper recovery is 31.8% after 27 days.

  9. Water requirements of the copper industry

    Science.gov (United States)

    Mussey, Orville Durey

    1961-01-01

    The copper industry in 1955 used about 330 million gallons of water per day in the mining and manufacturing of primary copper. This amount is about 0.3 percent of the total estimated withdrawals of industrial water in the United States in 1955. These facts were determined by a survey, in 1956, of the amount and chemical quality of the water used by the copper industry. A large part of this water was used in Arizona, Nevada, New Mexico, and Utah, where about five-sixths of the domestic copper is mined. Much of the remaining water use was near New York City where most of the electrolytic refineries are located, and the rest of the water was used in widely scattered places. A little more than 100,000 gallons of water per ton of copper was used in the production of copper from domestic ores. Of this amount about 70,000 gallons per ton was used in mining and concentrating the ore, and about 30,000 gallons per ton was used to reduce the concentrate to refined copper. In areas where water was scarce or expensive, the unit water use was a little more than half the average. About 60 mgd (million gallons per day) or 18 percent of the water was used consumptively, and nearly all of the consumptive use occurred in the water-short areas of the West. Of the water used in mining and manufacturing primary copper 75 percent was surface water and 25 percent was ground water, 89 percent of this water was self-supplied by the copper companies and 11 percent came from public supplies. Much of the water used in producing primary copper was of comparatively poor quality; about 46 percent was saline containing 1,000 ppm (parts per million) or more of dissolved solids and 54 percent was fresh. Water that is used for concentration of copper ores by flotation or even any water that comes in contact with the ore at any time before it reaches the flotation plant must be free of petroleum products because they interfere with the flotation process. The water used in mining and ore concentration

  10. Electrochemical nucleation and growth of copper and copper alloys

    Science.gov (United States)

    Shao, Wenbo

    This dissertation aims to contribute to a fundamental understanding of the physicochemical processes occurring in electrochemical nucleation and growth. To this end, the effects of various anions (chloride (Cl-), sulfate (SO42-) and sulfamate (NH2SO 3-)) on the electrochemical kinetics and the mechanism of copper reduction, as well as on the microstructure of the resulting films, were studied. On the basis of this work, the deposition of copper alloys (Cu-Ag with positive heat of mixing, Cu-Au with negative heat of mixing) was investigated with the main objective to achieve an insight on the role of solid state thermodynamics on the electrocrystallization process. Chloride ions cause two competing effects: at low chloride concentration the formation of an adsorbed chloride layer introduces an additional reaction pathway, resulting in an overall depolarization of the reduction process with no significant change of the Tafel slope. At high chloride concentration, complexation phenomena induce a cathodic polarization of the deposition process and a decrease in the Tafel slope. Chlorides cause a decrease in the density and an increased size of copper nuclei. Sulfamate depolarizes copper reduction the most and results in the largest nucleus density. Chloride promotes the faceting, and dendritic growth of copper deposits along direction by introducing interfacial anisotropy. Addition of Ag in the solution or in the electrode substrate enhances copper deposition and results in an additional reduction peak. Codeposition of Cu-Ag increases nucleus density and decreases nucleus size. Such enhancement of copper deposition, the increase in nucleus density and the decrease in nucleus size by Ag could be due to the continued formation of a surface alloy of Cu-Ag and the fast interface dynamics of Ag deposition. Cu can be underpotentially codeposited in the Cu-Au alloy. Homogeneous solid solutions are grown under conditions of underpotential deposition of Cu, while precipitation

  11. Cloud Computing (1)

    Institute of Scientific and Technical Information of China (English)

    Wang Bai; Xu Liutong

    2010-01-01

    @@ Editor's Desk: Cloud computing is a topic of intense interest in the Internet field. Major IT giants have launched their own cloud computing products. This four-part lecture series will discuss cloud computing technology in the following aspects: The first part provides a brief description of the origin and characteristics of cloud computing from the users view of point; the other parts introduce typical applications of cloud computing, technically analyze the specific content within the cloud, its components, architecture and computational paradigm, compare cloud computing to other distributed computing technologies, and discuss its successful cases, commercial models, related technical and economic issues, and development trends.

  12. Cloud Computing (2)

    Institute of Scientific and Technical Information of China (English)

    Wang Bai; Xu Liutong

    2010-01-01

    @@ Editor's Desk: Cloud computing is a topic of intense interest in the Internet field. Major IT giants have launched their own cloud computing products. This four-part lecture series discusses cloud computing technology in the following aspects: The first part provided a brief description of the origin and characteristics of cloud computing from the users view of point; the other parts introduce typical applications of cloud computing, technically analyze the specific content within the cloud, its components, architecture and computational paradigm, compare cloud computing to other distributed computing technologies, and discuss its successful cases, commercial models, related technical and economic issues, and development trends.

  13. Cloud storage for dummies

    CERN Document Server

    Xu, Linda; Loughlin, Tanya

    2010-01-01

    Understand cloud computing and save your organization time and money! Cloud computing is taking IT by storm, but what is it and what are the benefits to your organization? Hitachi Data Systems' Cloud Storage For Dummies provides all the answers, With this book, you discover a clear explanation of cloud storage, and tips for how to choose the right type of cloud storage for your organization's needs. You also find out how cloud storage can free up valuable IT resources, saving time and money. Cloud Storage For Dummies presents useful information on setting up a

  14. Robots and sensor clouds

    CERN Document Server

    Shakshuki, Elhadi

    2016-01-01

    This book comprises four chapters that address some of the latest research in clouds robotics and sensor clouds. The first part of the book includes two chapters on cloud robotics. The first chapter introduces a novel resource allocation framework for cloud robotics and proposes a Stackelberg game model and the corresponding task oriented pricing mechanism for resource allocation. In the second chapter, the authors apply Cloud Computing for building a Cloud-Based 3D Point Cloud extractor for stereo images. Their objective is to have a dynamically scalable and applicable to near real-time scenarios.  .

  15. Reducing the Content of Fluorine and Magnesium in a Copper Sulfide Concentrate in Anhui Province Using the Inhibitor DG11%用抑制剂DG11降低安徽某硫化铜精矿氟镁含量

    Institute of Scientific and Technical Information of China (English)

    李汉文; 王晨亮; 胡真; 李沛伦

    2016-01-01

    安徽某硫化铜矿选矿厂铜精矿铜品位为18.20%,F、MgO含量分别为0.25%和9.26%,不仅铜品位偏低,且F、MgO含量不满足冶炼厂对铜精矿F含量小于0.1%、MgO含量小于5%的要求。研究查明,含F、MgO易泥化、易浮滑石、蛇纹石和绿泥石等以微细粒大量混杂进入铜精矿是造成现场铜精矿F、MgO含量超标的主要原因。以广东省资源综合利用研究所研发的DG11为含氟镁脉石矿物的抑制剂,采用1粗1精1扫、中矿顺序返回浮选流程处理现场铜精矿,最终获得了铜品位为25.11%、铜回收率为97.45%,F和MgO含量分别为0.082%和2.02%的铜精矿,既显著提高了精矿铜品位,又大幅度降低了精矿氟、镁含量,达到冶炼厂对铜精矿F和MgO含量的要求。%The copper concentrate products of a sulfide copper ore dressing plant in Anhui province containing 18.20%Cu,0.25% F,9.26% MgO.Not only the copper grade is low,but also the content of fluorine and magnesium exceeds the standard of the smelting plant requires (content of F<0.1%,content of MgO<5%).Studies have shown that easy mudding and easy floating talc,serpentine and chlorite exist in the form of fine particles,these minerals containing F,MgO and in large mixed into the copper concentrate,which is the main cause of fluoride,magnesium content in on-site copper concentrate ex-ceeds the standard.Using DG1 1 developed by Guangdong Institute of Resources Comprehensive Utilization as inhibitor of the gangue minerals which contain fluorine and magnesium.Through the process of one roughing-one cleaning-one scavenging,and middling returning in proper order into the flow,the results show that the copper concentrate have 25.1 1%grade and 97.45%recovery rate,including 0.082% F,2.02%MgO.It not only improves the grade of copper concentrate,but also greatly reduces the content of fluorine and magnesium in the concentrate,and reached the requirements of copper smelting

  16. [Copper pathology (author's transl)].

    Science.gov (United States)

    Mallet, B; Romette, J; Di Costanzo, J D

    1982-01-30

    Copper is an essential dietary component, being the coenzyme of many enzymes with oxidase activity, e.g. ceruloplasmin, superoxide dismutase, monoamine oxidase, etc. The metabolism of copper is complex and imperfectly known. Active transport of copper through the intestinal epithelial cells involves metallothionein, a protein rich in sulfhydryl groups which also binds the copper in excess and probably prevents absorption in toxic amounts. In hepatocytes a metallothionein facilitates absorption by a similar mechanism and regulates copper distribution in the liver: incorporation in an apoceruloplasmin, storage and synthesis of copper-dependent enzymes. Metallothioneins and ceruloplasmin are essential to adequate copper homeostasis. Apart from genetic disorders, diseases involving copper usually result from hypercupraemia of varied origin. Wilson's disease and Menkes' disease, although clinically and pathogenetically different, are both marked by low ceruloplasmin and copper serum levels. The excessive liver retention of copper in Wilson's disease might be due to increased avidity of hepatic metallothioneins for copper and decreased biliary excretion through lysosomal dysfunction. Menkes' disease might be due to low avidity of intestinal and hepatic metallothioneins for copper. The basic biochemical defect responsible for these two hereditary conditions has not yet been fully elucidated.

  17. [Copper IUDs (author's transl)].

    Science.gov (United States)

    Thiery, M

    1983-10-01

    Following initial development of the Grafenberg ring in the 1920's, IUDs fell into disuse until the late 1950s, when plastic devices inserted using new technology began to gain worldwide acceptance. Further research indicated that copper had a significant antifertility effect which increased with increasing surface area, and several copper IUDs were developed and adapted, including the Copper T 200, the Copper T 220C, and the Copper T 380 A, probably the most effective yet. The Gravigard and Multiload are 2 other copper devices developed according to somewhat different principles. Copper devices are widely used not so much because of their great effectiveness as because of their suitability for nulliparous patients and their ease of insertion, which minimizes risk of uterine perforation. Records of 2584 women using Copper IUDs for 7190 women-years and 956 women using devices without copper for 6059 women-years suggest that the copper devices were associated with greater effectiveness and fewer removals for complications. Research suggests that the advantages of copper IUDs become more significant with increased duration of use. Contraindications to copper devices include allergy to copper and hepatolenticular degeneration. No carcinogenic or teratogenic effect of copper devices has been found, but further studies are needed to rule out other undesirable effects. Significant modifications of copper devices in recent years have been developed to increase their effectiveness, prolong their duration of usefulness, facilitate insertion and permit insertion during abortion or delivery. The upper limit of the surface area of copper associated with increased effectiveness appears to be between 200-300 sq mm, and at some point increases in copper exposure may provoke expulsion of the IUD. The duration of fertility inhibition of copper IUDs is usually estimated at 2-3 years, but recent research indicates that it may be 6-8 years, and some devices may retain copper surface

  18. Copper resistance in Enterococcus faecium, mediated by the tcrB gene, is selected by supplementation of pig feed with copper sulfate

    DEFF Research Database (Denmark)

    Hasman, Henrik; Kempf, I.; Chidaine, B.;

    2006-01-01

    The tcr gene cluster mediates in vitro copper resistance in Enterococcus faecium. Here we describe the selection of tcr-mediated copper resistance in E. faecium in an animal feeding experiment with young pigs fed 175 mg copper/kg feed (ppm), which is the concentration commonly used for piglets...... in European pig production. tcr-mediated copper resistance was not selected for in a control group fed low levels of copper (6 ppm). We also show coselection of macrolide- and glycopeptide-resistant E. faecium in the animal group fed the high level of copper. Finally, we identify the tcr genes...

  19. Modelling [CI] emission from turbulent molecular clouds

    CERN Document Server

    Glover, Simon C O; Micic, Milica; Molina, Faviola

    2014-01-01

    We use detailed numerical simulations of the coupled chemical, thermal and dynamical evolution of the gas in a turbulent molecular cloud to study the usefulness of the [CI] 609 micron and 370 micron fine structure emission lines as tracers of cloud structure. Emission from these lines is observed throughout molecular clouds, and yet the question of what we can learn from them about the physics of the clouds remains largely unexplored. We show that the fact that [CI] emission is widespread within molecular clouds is a simple consequence of the fact that the clouds are dominated by turbulent motions. Turbulence creates large density inhomogeneities, allowing radiation to penetrate deeply into the clouds. As a result, [CI] emitting gas is found throughout the cloud, rather than being concentrated at the edges. We examine how well we can use [CI] emission to trace the structure of the cloud, and show that the integrated intensity of the 609 micron line traces column density accurately over a wide range of visual ...

  20. The CLOUD experiment

    CERN Multimedia

    Maximilien Brice

    2006-01-01

    The Cosmics Leaving Outdoor Droplets (CLOUD) experiment as shown by Jasper Kirkby (spokesperson). Kirkby shows a sketch to illustrate the possible link between galactic cosmic rays and cloud formations. The CLOUD experiment uses beams from the PS accelerator at CERN to simulate the effect of cosmic rays on cloud formations in the Earth's atmosphere. It is thought that cosmic ray intensity is linked to the amount of low cloud cover due to the formation of aerosols, which induce condensation.

  1. Cloud Computing (3)

    Institute of Scientific and Technical Information of China (English)

    Wang Bai; Xu Liutong

    2010-01-01

    @@ Editor's Desk: In the preceding two parts of this series, several aspects of cloud computing-including definition, classification, characteristics, typical applications, and service levels-were discussed. This part continues with a discussion of Cloud Computing Oopen Architecture and Market-Oriented Cloud. A comparison is made between cloud computing and other distributed computing technologies, and Google's cloud platform is analyzed to determine how distributed computing is implemented in its particular model.

  2. Cloud Robotics Platforms

    Directory of Open Access Journals (Sweden)

    Busra Koken

    2015-01-01

    Full Text Available Cloud robotics is a rapidly evolving field that allows robots to offload computation-intensive and storage-intensive jobs into the cloud. Robots are limited in terms of computational capacity, memory and storage. Cloud provides unlimited computation power, memory, storage and especially collaboration opportunity. Cloud-enabled robots are divided into two categories as standalone and networked robots. This article surveys cloud robotic platforms, standalone and networked robotic works such as grasping, simultaneous localization and mapping (SLAM and monitoring.

  3. COPPER RESISTANT STRAIN CANDIDA TROPICALIS RomCu5 INTERACTION WITH SOLUBLE AND INSOLUBLE COPPER COMPOUNDS

    Directory of Open Access Journals (Sweden)

    Ie. P. Prekrasna

    2015-10-01