WorldWideScience

Sample records for nickel concentration profiles

  1. Urine nickel concentrations in nickel-exposed workers.

    Science.gov (United States)

    Bernacki, E J; Parsons, G E; Roy, B R; Mikac-Devic, M; Kennedy, C D; Sunderman, F W

    1978-01-01

    Electrothermal atomic absorption spectrometry was employed for analyses of nickel concentrations in urine samples from nickel-exposed workers in 10 occupational groups and from non-exposed workers in two control groups. Mean concentrations of nickel in urine were greatest in workers who were exposed to inhalation of aerosols of soluble nickel salts (e.g., workers in nickel plating operations and in an electrolytic nickel refinery). Less marked increases in urine nickel concentrations were found in groups of metal sprayers, nickel battery workers, bench mechanics and are welders. No significant increases in mean concentrations of nickel were found in urine samples from workers who performed grinding, buffing and polishing of nickel-containing alloys or workers in a coal gasification plant who employed Raney nickel as a hydrogenation catalyst. Measurements of nickel concentrations in urine are more sensitive and practical than measurements of serum nickel concentrations for evaluation of nickel exposures in industrial workers.

  2. Effects of repeated skin exposure to low nickel concentrations

    DEFF Research Database (Denmark)

    Nielsen, N H; Menné, T; Kristiansen, J

    1999-01-01

    and nickel allergy, either on normal or on SLS-treated forearm skin. The present study strongly suggests that the changes observed were specific to nickel exposure. Standardized methods to assess trace to moderate nickel exposure on the hands, and the associated effects in nickel-sensitized subjects......We studied the effects of repeated daily exposure to low nickel concentrations on the hands of patients with hand eczema and nickel allergy. The concentrations used were chosen to represent the range of trace to moderate occupational nickel exposure. The study was double-blinded and placebo...... controlled. Patients immersed a finger for 10 min daily into a 10-p.p.m. nickel concentration in water for the first week, and during the second week into a 100-p.p.m. nickel concentration. This regimen significantly increased (P = 0.05) local vesicle formation and blood flow (P = 0.03) as compared...

  3. Nickel concentrations in fingernails as a measure of occupational exposure to nickel

    DEFF Research Database (Denmark)

    Peters, K; Gammelgaard, Bente; Menné, T

    1991-01-01

    in nails (p less than 0.001). The difference between the 2 levels was also significant (p less than 0.001). No correlation between the nickel concentration in fingernails and the duration of exposure could be demonstrated. It was concluded that the higher the nickel level in the fingernails, the greater...... is the possibility that the person is occupationally exposed to nickel. Nail analysis is suggested as a measure of occupational exposure to nickel.......The nickel concentration in fingernails from 2 groups of people occupationally exposed to nickel was determined. In one group, comprising 83 persons moderately exposed to nickel, the mean +/- standard deviation (SD) was 29.2 micrograms/g +/- 56.7 micrograms/g and the median 13.8 micrograms/g (range...

  4. Fluctuations of nickel concentrations in urine of electroplating workers

    International Nuclear Information System (INIS)

    Bernacki, E.J.; Zygowicz, E.; Sunderman, F.W. Jr.

    1980-01-01

    Nickel analyses were performed by electrothermal atomic absorption spectrometry upon urine specimens obtained from electroplating workers at the beginning, middle and end of the work-shift. The means (+- S.D.) for nickel concentrations in urine specimens from seven electroplating workers on three regular workdays were: 34 +- 32 μg/L (pre-shift); 64 +- μg/L (mid-shift) and 46 +- μg/L (end-shift), compared to 2.7 +- 1.6 μg/L (pre-shift) in 19 controls (hospital workers). Nickel concentrations in urine specimens from six electroplating workers on the first workday after a two-week vacation averaged: 5 +- 3 μg/L (pre-shift); 9 +- 6 μg/L (mid-shift), and 12 +- 6 μg/L (end-shift). Nickel concentrations in personal air samples (seven hours) collected from the breathing zones of five electroplating workers on three regular workdays averaged 9.3 +- 4.4 μg/m 3 . Nickel concentrations in the air samples were correlated with nickel concentrations in end-shift urine specimens (corr. coef. = 0.70; P < 0.05), but were not correlated with nickel concentrations in pre-shift or mid-shift urine specimens. In view of the fluctuations of urine nickel concentrations that occur during the work-shift, the authors recommend that nickel analyses of eight hour urine specimens be used routinely to monitor occupational exposures to nickel. In situations where timed urine collections are impractical, analyses of end-shift urine specimens are the best alternative

  5. Reference values for the nickel concentration in human finger nails

    DEFF Research Database (Denmark)

    Gammelgaard, Bente; Peters, K; Menné, T

    1991-01-01

    A reference value for the nickel concentration in finger nails from people who are not occupationally exposed to nickel was determined on the basis of nail samples from 95 healthy individuals. The mean +/- standard deviation was 1.19 +/- 1.61 mg/kg and the median was 0.49 mg/kg (range 0.042-7.50 mg...

  6. Nickel-induced cytokine production from mononuclear cells in nickel-sensitive individuals and controls. Cytokine profiles in nickel-sensitive individuals with nickel allergy-related hand eczema before and after nickel challenge

    DEFF Research Database (Denmark)

    Borg, L; Christensen, J M; Kristiansen, J

    2000-01-01

    Exposure to nickel is a major cause of allergic contact dermatitis which is considered to be an inflammatory response induced by antigen-specific T cells. Here we describe the in vitro analysis of the nickel-specific T-cell-derived cytokine response of peripheral blood mononuclear cells from 35...... was somewhat of a surprise, since previous studies have suggested a Th1 response in nickel-mediated allergic contact dermatitis. Subsequently, the nickel-allergic individuals were randomized to experimental exposure to nickel or vehicle in a double-blind design. A daily 10-min exposure of one finger to 10 ppm...... nickel solution for 1 week followed by 100 ppm for an additional week evoked a clinical response of hand eczema in the nickel-exposed group. Blood samples were drawn on days 7 and 14 after the start of this exposure to occupationally relevant concentrations of nickel. No statistically significant...

  7. Impedances of nickel electrodes cycled in various KOH concentrations

    Science.gov (United States)

    Reid, Margaret A.; Loyselle, Patricia L.

    1991-01-01

    Recent tests at Hughes have shown that Ni/H2 cells cycled in 26 percent KOH have much longer lives than those cycled in other concentrations. As part of an ongoing program to try to correlate the impedances of nickel electrodes with their life and performance, impedances were measured of a number of electrodes from these tests that had been cycled in concentrations from 21 to 36 percent KOH. These had ranged from about 1000 to 40,000 cycles. After cycling ten times to reduce possible changes due to storage, impedances were measured at five voltages corresponding to low states of charge. The results were analyzed using a standard circuit model including Warburg impedance term. Lower kinetic resistances and Warburg slopes were found for several electrodes which had been cycled in 26 percent KOH even though they had been cycled for a much longer time than the others. Interpretation of the data is complicated by the fact that the cycle lives, storage times, and failure mechanisms varied. Several other circuit models have also been examined, but the best correlations with life were found with parameters obtained from the simple model.

  8. The effects of different nickel concentrations on some morpho-physiological characteristics of parsley (Petroselinum crispum

    Directory of Open Access Journals (Sweden)

    mitra khatib

    2009-06-01

    Full Text Available Nickel as a heavy metal is considered a fatal and toxic element for humans, animals and plants. However, some plants are known as hyper accumulator for nickel and sometimes seem to be useful for plant growth. Thus, investigation on the effect of nickel on plants' growth is an issue of importance. In this paper, we have studied the effect of different nickel concentrations on parsley growth and morph-physiological characteristics and its effect on absorption of some macro elements in this plant. Seeds of parsley were germinated in germinator and seedlings were transferred to hydroponics culture. The seedlings were grown in Hogland solution with different nickel concentrations (in form of nickel nitrate of: 0, 0.25, 0.5, 0.75, 1, 1.5, 2 and 4 ppm. A completely randomized design with 8 treatments and 7 replications per treatment was used. Twelve weeks after treatments, morph-physiological characteristics including SPAD number, plant biomass, length of shoot and root, leaf area, leaf number and stomatal resistance were measured. The amount of absorbed nickel in plant foliages and roots of different treatments were also measured. The results revealed that the application of different nickel concentrations were decreased SPAD number, plant biomass, leaf area and leaf number, but the stomatal resistance were increased. Increase of nickel concentration resulted increasing Ni concentrations of plant foliages and roots. Nickel with 0.75 ppm concentration or higher imposed a toxic effect on parsley as general wilting and significant reduction in most morph-physiological characteristics. Keywords: Hydroponics culture, parsley, Petroselinum crispum, Nickel.

  9. Determination of nickel and thallium concentration in Cynoglossus arel fish in Musa estuary, Persian Gulf, Iran.

    Science.gov (United States)

    Jaafarzadeh Haghighi Fard, Neamat; Zare Javid, Ahmad; Ravanbakhsh, Maryam; Ramezani, Zahra; Ahmadi, Mehdi; Angali, Kambiz Ahmadi; Ardeshirzadeh, Shirin

    2017-01-01

    Heavy metals with high bioaccumulation capacity are considered as important contaminants and may be available in high concentrations in environment and biota samples. The main aim of this study was to determine the concentration of nickel and thallium in Cynoglossus arel fish in Musa estuary. Sixty-seven fish samples were collected from Musa estuary during five intervals of 15 days in summer 2013. After biometric measurements, the concentrations of nickel and thallium were measured by graphite furnace atomic absorption spectrophotometer. The mean concentration of nickel and thallium in muscle tissue of fish samples was 2.458 ± 0.910 and 0.781 ± 1.754 mg kg -1 /ww, respectively. The GLM analysis showed a significant negative relationship between nickel concentration and length. In addition, there was a significant positive relationship between thallium concentration and fish length. Nickel concentration exceeded the allowable standards of WHO and FDA in Cynoglossus arel. Therefore, regarding with high consumption of seafood in this region, it is recommended that these fishes should be consumed under a nutritionist counseling.

  10. KOH concentration effect on the cycle life of nickel-hydrogen cells

    Science.gov (United States)

    Lim, H. S.; Verzwyvelt, S. A.

    1985-01-01

    Effects of KOH concentration on the cycle life of a sintered-type nickel electrode were studied in a boiler plate nickel-hydrogen cell at 23 C using an accelerated 45-min cycle regime at 80 percent depth of discharge. The cycle life improved greatly as the KOH concentration decreased, although the initial capacity of the cell decreased slightly. The cycle life improved by a factor of two or more when the KOH concentration was reduced from 36 to 31 percent and by a similar factor from reductions of 31 to 26 percent. For many applications, this life improvement may outweigh the initial capacity decrease.

  11. Effect of L-ascorbic acid on nickel-induced alterations in serum lipid profiles and liver histopathology in rats.

    Science.gov (United States)

    Das, Kusal K; Gupta, Amrita Das; Dhundasi, Salim A; Patil, Ashok M; Das, Swastika N; Ambekar, Jeevan G

    2006-01-01

    Nickel exposure greatly depletes intracellular ascorbate and alters ascorbate-cholesterol metabolism. We studied the effect of the simultaneous oral treatment with L-ascorbic acid (50 mg/100 g body weight (BW) and nickel sulfate (2.0 mg/100 g BW, i.p) on nickelinduced changes in serum lipid profiles and liver histopathology. Nickel-treated rats showed a significant increase in serum low-density lipoprotein-cholesterol, total cholesterol, triglycerides, and a significant decrease in serum high-density lipoprotein-cholesterol. In the liver, nickel sulfate caused a loss of normal architecture, fatty changes, extensive vacuolization in hepatocytes, eccentric nuclei, and Kupffer cell hypertrophy. Simultaneous administration of L-ascorbic acid with nickel sulfate improved both the lipid profile and liver impairments when compared with rats receiving nickel sulfate only. The results indicate that L-ascorbic acid is beneficial in preventing nickel-induced lipid alterations and hepatocellular damage.

  12. Fluorine concentration profiles in archaeological bone

    International Nuclear Information System (INIS)

    Coote, G.E.; Sparks, R.J.

    1981-01-01

    The nuclear microprobe at the Institute of Nuclear Sciences was applied to the measurement of radial concentration profiles of fluorine, in transverse slices of archaeological bone from humans, moas, and other animals. A beam of 2.5 MeV protons was focused to a rectangular spot 250 microns by 50 microns, traversed along a radial line 3mm long, and gamma rays of 5-7 MeV from the reaction 19 F(p, α#betta#) 16 O were detected in a large sodium iodide crystal. Bombardment caused no detectable loss of fluorine from the bone. Measured profiles display a wide variety of shapes and maximum concentrations. In bones which had been exposed to ground water the fluorine concentration usually increases from the centre towards the surface, sometimes by as much as a factor of eight. The concentration at the surface is usually in the range 0.2 to 1%, though in moa bone from a limestone cave it is only 0.025%. Once a quantitative method of analysis has been developed, based on the shape of the profile rather than its magnitude, these profiles might be useful for dating bone. In the meantime, they could be used to distinguish bones of different ages from a common site

  13. Concentration profiles near an activated enzyme.

    Science.gov (United States)

    Park, Soohyung; Agmon, Noam

    2008-09-25

    When a resting enzyme is activated, substrate concentration profile evolves in its vicinity, ultimately tending to steady state. We use modern theories for many-body effects on diffusion-influenced reactions to derive approximate analytical expressions for the steady-state profile and the Laplace transform of the transient concentration profiles. These show excellent agreement with accurate many-particle Brownian-dynamics simulations for the Michaelis-Menten kinetics. The steady-state profile has a hyperbolic dependence on the distance of the substrate from the enzyme, albeit with a prefactor containing the complexity of the many-body effects. These are most conspicuous for the substrate concentration at the surface of the enzyme. It shows an interesting transition as a function of the enzyme turnover rate. When it is high, the contact concentration decays monotonically to steady state. However, for slow turnover it is nonmonotonic, showing a minimum due to reversible substrate binding, then a maximum due to diffusion of new substrate toward the enzyme, and finally decay to steady state. Under certain conditions one can obtain a good estimate for the critical value of the turnover rate constant at the transition.

  14. A MATHEMATICAL MODEL TO PREDICT NICKEL CONCENTRATION IN KARAJ RIVER SEDIMENTS

    Directory of Open Access Journals (Sweden)

    R. Ramezankhani, A. A. M. Sharif, M. T. Sadatipour, R.Abdolahzadeh

    2008-04-01

    Full Text Available The contamination of surface waters through human activities has been intensified over the past years as population density has increased. Nickel is a metallic element and fuel combustion, nickel mining, refining waste, sewage sludge, and incineration are the major sources of nickel propagation. Nickel from various industrial wastewaters and other sources finally are disposed into water bodies. In this work, Karaj river was considered from 50º to 50º 14´longitudes and 35º 45´ to 35º 58´ latitudes and the presence of nickel was also assessed in this area. Sixteen stations were randomly selected and sediment samples were collected in polyethylene containers. Some water quality parameters such as pH, temperature, dissolved oxygen, electrical conductivity, were determind by direct on-site measurements. To measure COD, 16 water samples were collected in dark bottles and transferred to laboratory spatial parameters such as slope and distance from start point were also calculated by ARCGIS 9.2. The relation between Ni concentration with spatial parameters and water quality parameters were obtained by multivariate analysis. Results showed that there was a significant relation between Ni concentration in sediments and distance from start point and electrical conductivity.

  15. Nickel-tolerant ectomycorrhizal Pisolithus albus ultramafic ecotype isolated from nickel mines in New Caledonia strongly enhance growth of the host plant Eucalyptus globulus at toxic nickel concentrations.

    Science.gov (United States)

    Jourand, Philippe; Ducousso, Marc; Reid, Robert; Majorel, Clarisse; Richert, Clément; Riss, Jennifer; Lebrun, Michel

    2010-10-01

    Ectomycorrhizal (ECM) Pisolithus albus (Cooke & Massee), belonging to the ultramafic ecotype isolated in nickel-rich serpentine soils from New Caledonia (a tropical hotspot of biodiversity) and showing in vitro adaptive nickel tolerance, were inoculated to Eucalyptus globulus Labill used as a Myrtaceae plant-host model to study ectomycorrhizal symbiosis. Plants were then exposed to a nickel (Ni) dose-response experiment with increased Ni treatments up to 60 mg kg( - )(1) soil as extractable Ni content in serpentine soils. Results showed that plants inoculated with ultramafic ECM P. albus were able to tolerate high and toxic concentrations of Ni (up to 60 μg g( - )(1)) while uninoculated controls were not. At the highest Ni concentration tested, root growth was more than 20-fold higher and shoot growth more than 30-fold higher in ECM plants compared with control plants. The improved growth in ECM plants was associated with a 2.4-fold reduction in root Ni concentration but a massive 60-fold reduction in transfer of Ni from root to shoots. In vitro, P. albus strains could withstand high Ni concentrations but accumulated very little Ni in its tissue. The lower Ni uptake by mycorrhizal plants could not be explained by increased release of metal-complexing chelates since these were 5- to 12-fold lower in mycorrhizal plants at high Ni concentrations. It is proposed that the fungal sheath covering the plant roots acts as an effective barrier to limit transfer of Ni from soil into the root tissue. The degree of tolerance conferred by the ultramafic P. albus isolates to growth of the host tree species is considerably greater than previously reported for other ECM. The primary mechanisms underlying this improved growth were identified as reduced Ni uptake into the roots and markedly reduced transfer from root to shoot in mycorrhizal plants. The fact that these positive responses were observed at Ni concentrations commonly observed in serpentinic soils suggests that

  16. First steps towards cube textured nickel profile wires for YBCO-coated conductors

    International Nuclear Information System (INIS)

    Eickemeyer, J.; Gueth, A.; Freudenberger, J.; Holzapfel, B.; Schultz, L.

    2011-01-01

    The cube texture as a typical sheet texture can also be formed by cold drawing and recrystallization in profile wires. Cube textured Ni profile wires containing up to 96.2% cube oriented grains in the central region were obtained. Forthcoming investigations are promising to get a textured substrate wire for YBCO-coated conductors. Cube textured nickel alloy tapes prepared by cold rolling and annealing (RABiTS method) represent a standard metallic substrate for superconductor coatings of the YBa 2 Cu 3 O 7-δ (YBCO) type. These tapes have a width to thickness ratio of about 30-100. However, a value of close to one is optimal concerning low energetic losses under alternating current applications. First experiments on micro-alloyed nickel prove that the cube texture as a typical sheet texture can also be formed in profile wires with a rectangular cross-section after cold drawing and recrystallization treatment.

  17. Lead, selenium and nickel concentrations in epithelial ovarian cancer, borderline ovarian tumor and healthy ovarian tissues.

    Science.gov (United States)

    Canaz, Emel; Kilinc, Metin; Sayar, Hamide; Kiran, Gurkan; Ozyurek, Eser

    2017-09-01

    Wide variation exists in ovarian cancer incidence rates suggesting the importance of environmental factors. Due to increasing environmental pollution, trace elements and heavy metals have drawn attention in studies defining the etiology of cancer, but scant data is available for ovarian cancer. Our aim was to compare the tissue concentrations of lead, selenium and nickel in epithelial ovarian cancer, borderline tumor and healthy ovarian tissues. The levels of lead, selenium and nickel were estimated using atomic absorption spectrophotometry in formalin-fixed paraffin-embedded tissue samples. Tests were carried out in 20 malignant epithelial ovarian cancer, 15 epithelial borderline tumor and 20 non-neoplastic healthy ovaries. Two samples were collected for borderline tumors, one from papillary projection and one from the smooth surface of cyst wall. Pb and Ni concentrations were found to be higher both in malignant and borderline tissues than those in healthy ovaries. Concentrations of Pb and Ni in malignant tissues, borderline papillary projections and capsular tissue samples were not different. Comparison of Se concentrations of malignant, borderline and healthy ovarian tissues did not reveal statistical difference. Studied metal levels were not found to be different in either papillary projection or in cyst wall of the borderline tumors. This study revealed the accumulation of lead and nickel in ovarian tissue is associated with borderline and malignant proliferation of the surface epithelium. Accumulation of these metals in epithelial ovarian cancer and borderline ovarian tumor has not been demonstrated before. Copyright © 2017 Elsevier GmbH. All rights reserved.

  18. Plants sensitivity on nickel under different conditions of iron or calcium concentration in the nutrient medium

    Directory of Open Access Journals (Sweden)

    Renata Matraszek

    2013-12-01

    Full Text Available The sensitivity of six vegetable plants on nickel at early stages of their growth was investigated by index of tolerance. Besides the possibility of nickel fitostabilization by additional application of iron or calcium was tested. The experiment was conducted on Petri dishes. Different concentrations of nickel (0; 0,03; 0,06mM Ni as nickel sulphate, iron (0,05; O,OlmM Fe as Fe2+ citrate and calcium (0,50; 0,75; lmM Ca as calcium carbonate were added. Taking into consideration the sensitivity, investigated vegetables can be ordered in the following way: Cucurbita pepo conv. giromontiina L.>Lactuca sativa L.>Sinapis alba L.>Spinacia oleracea L.=Zea mays var. saccharata Kcke.>Phaseolus vulgaris L. Positive, statistically significant effect ofnickel fitostabilization (0,03 or 0,06mM Ni on elongative growth by the iron application (0,10mM Fe was shown for Zea mays var. saccharata Kcke independently of Ni concentration in the nutrient medium as well as for Sinapis alba L. and Phaseolus vulgaris L. in 0,06mM Ni. Addition as much as 0,75mM Ca in the presence 0,03mM Ni had positive result on Sinapis alba L and Phaseolus vulgaris L. seedlings as well as on Zea mays var. saccharata Kcke and Lactuca sativa L. roots and Cucurbita pepo convar. giromontiina L. shoots. Addition of 0,75mM Ca in the presence 0,06mM Ni promoted elongative growth of Zea mays var. saccharata Kcke seedlings. Application lmM Ca resulted in the promotion of elongative growth of Zea mays var. saccharata Kcke. roots (0,03mM Ni as well as Spinacia oleracea L. roots (0,06mM Ni.

  19. Differential gene expression profile of the calanoid copepod, Pseudodiaptomus annandalei, in response to nickel exposure.

    Science.gov (United States)

    Jiang, Jie-Lan; Wang, Gui-Zhong; Mao, Ming-Guang; Wang, Ke-Jian; Li, Shao-Jing; Zeng, Chao-Shu

    2013-03-01

    To better understand the underlying mechanisms of reactions of copepods exposed to elevated level of nickel, the suppression subtractive hybridization (SSH) was used to elucidate the response of the copepod Pseudodiaptomus annandalei to nickel exposure at the gene level. P. annandale is one of a few copepod species that can be cultured relatively easy under laboratory condition, and it is considered to be a potential model species for toxicity study. In the present study, P. annandalei were exposed to nickel at a concentration of 8.86 mgL(-1) for 24h, after which the RNA was prepared for SSH using unexposed P. annandalei as drivers. A total of 474 clones on the middle scale in the SSH library were sequenced. Among these genes, 129 potential functional genes were recognized based on the BLAST searches in NCBI and Uniprot databases. These genes were then categorized into nine groups in association with different biological processes using AmiGO against the Gene Ontology database. Of the 129 genes, 127 translatable DNA sequences were predicted to be proteins, and the putative amino acid sequences were searched for conserved domains (CD) and proteins using the CD-Search service and BLASTp. Among 129 genes, 119 (92.2%) were annotated to be involved in different biological processes, while 10 genes (7.8%) were classified as an unknown-function gene group. To further confirm the up-regulation of differentially expressed genes, the quantitative real time PCR were performed to test eight randomly selected genes, in which five of them, i.e. α-tubulin, ribosomal protein L13, ferritin, separase and Myohemerythrin-1, exhibited clear up-regulation after nickel exposure. In addition, MnSOD was further studied for the differential expression pattern after nickel exposure and the results showed that MnSOD had a time- and dose-dependent expression pattern in the copepod after nickel exposure. To the best of our knowledge, this is the first attempt to investigate the toxicity

  20. Profiling and quantitative evaluation of three Nickel-Coated magnetic matrices for purification of recombinant proteins: lelpful hints for the optimized nanomagnetisable matrix preparation

    Directory of Open Access Journals (Sweden)

    Zarei Saeed

    2011-08-01

    Full Text Available Abstract Background Several materials are available in the market that work on the principle of protein magnetic fishing by their histidine (His tags. Little information is available on their performance and it is often quoted that greatly improved purification of histidine-tagged proteins from crude extracts could be achieved. While some commercial magnetic matrices could be used successfully for purification of several His-tagged proteins, there are some which have been proved to operate just for a few extent of His-tagged proteins. Here, we address quantitative evaluation of three commercially available Nickel nanomagnetic beads for purification of two His-tagged proteins expressed in Escherichia coli and present helpful hints for optimized purification of such proteins and preparation of nanomagnetisable matrices. Results Marked differences in the performance of nanomagnetic matrices, principally on the basis of their specific binding capacity, recovery profile, the amount of imidazole needed for protein elution and the extent of target protein loss and purity were obtained. Based on the aforesaid criteria, one of these materials featured the best purification results (SiMAG/N-NTA/Nickel for both proteins at the concentration of 4 mg/ml, while the other two (SiMAC-Nickel and SiMAG/CS-NTA/Nickel did not work well with respect to specific binding capacity and recovery profile. Conclusions Taken together, functionality of different types of nanomagnetic matrices vary considerably. This variability may not only be dependent upon the structure and surface chemistry of the matrix which in turn determine the affinity of interaction, but, is also influenced to a lesser extent by the physical properties of the protein itself. Although the results of the present study may not be fully applied for all nanomagnetic matrices, but provide a framework which could be used to profiling and quantitative evaluation of other magnetisable matrices and also

  1. KOH concentration effect on the cycle life of nickel-hydrogen cells. 4: Results of failure analyse

    Science.gov (United States)

    Lim, H. S.; Verzwyvelt, S. A.

    1989-01-01

    Effects of KOH concentrations on failure modes and mechanisms of nickel-hydrogen cells were studied using long cycled boiler plate cells containing electrolytes of various KOH concentrations ranging 21 to 36 percent. Life of these cells were up to 40,000 cycles in an accelerated low earth orbit (LEO) cycle regime at 80 percent depth of discharge. An interim life test results were reported earlier in J. Power Sources, 22, 213-220, 1988. The results of final life test, end-of-life cell performance, and teardown analyses are discussed. These teardown analyses included visual observations, measurements of nickel electrode capacity in an electrolyte-flooded cell, dimensional changes of cell components, SEM studies on cell cross section, BET surface area and pore volume distribution in cycled nickel electrodes, and chemical analyses. Cycle life of a nickel-hydrogen cell was improved tremendously as KOH concentration was decreased from 36 to 31 percent and from 31 to 26 percent while effect of further concentration decrease was complicated as described in our earlier report. Failure mode of high concentration (31 to 36 percent) cells was gradual capacity decrease, while that of low concentration (21 to 26 percent) cells was mainly formation of a soft short. Long cycled (25,000 to 40,000 cycles) nickel electrodes were expanded more than 50 percent of the initial value, but no correlation was found between this expansion and measured capacity. All electrodes cycled in low concentration (21 to 26 percent) cells had higher capacity than those cycled in high concentration (31 to 36 percent) cells.

  2. KOH concentration effect on cycle life of nickel-hydrogen cells. III - Cycle life test

    Science.gov (United States)

    Lim, H. S.; Verzwyvelt, S. A.

    1988-01-01

    A cycle life test of Ni/H2 cells containing electrolytes of various KOH concentrations and a sintered type nickel electrode was carried out at 23 C using a 45 min accelerated low earth orbit (LEO) cycle regime at 80 percent depth of discharge. One of three cells containing 26 percent KOH has achieved over 28,000 cycles, and the other two 19,000 cycles, without a sign of failure. Two other cells containing 31 percent KOH electrolyte, which is the concentration presently used in aerospace cells, failed after 2,979 and 3,620 cycles. This result indicates that the cycle life of the present type of Ni/H2 cells may be extended by a factor of 5 to 10 simply by lowering the KOH concentration. Long cycle life of a Ni/H2 battery at high depth-of-discharge operation is desired, particularly for an LEO spacecraft application. Typically, battery life of about 30,000 cycles is required for a five year mission in an LEO. Such a cycle life with presently available cells can be assured only at a very low depth-of-discharge operation. Results of testing already show that the cycle life of an Ni/H2 cell is tremendously improved by simply using an electrolyte of low KOH concentration.

  3. KOH concentration effect on cycle life of nickel-hydrogen cells

    Science.gov (United States)

    Lim, Hong S.; Verzwyvelt, S. A.

    1987-01-01

    A cycle life test of Ni/H2 cells containing electrolytes of various KOH concentrations and a sintered type nickel electrode was carried out at 23 C using a 45 min accelerated low Earth orbit (LEO) cycle regime at 80 percent depth of discharge. One of three cells containing 26 percent KOH has achieved over 28,000 cycles, and the other two 19,000 cycles, without a sign of failure. Two other cells containing 31 percent KOH electrolyte, which is the concentration presently used in aerospace cells, failed after 2,979 and 3,620 cycles. This result indicates that the cycle life of the present type of Ni/H2 cells may be extended by a factor of 5 to 10 simply by lowering the KOH concentration. Long cycle life of a Ni/H2 battery at high depth-of-discharge operation is desired, particularly for an LEO spacecraft application. Typically, battery life of about 30,000 cycles is required for a five year mission in an LEO. Such a cycle life with presently available cells can be assured only at a very low depth-of-discharge operation. Results of testing already show that the cycle life of an Ni/H2 cell is tremendously improved by simply using an electrolyte of low KOH concentration.

  4. Electrochemical behavior of heavily cycled nickel electrodes in Ni/H2 cells containing electrolytes of various KOH concentrations

    Science.gov (United States)

    Lim, H. S.; Verzwyvelt, S. A.

    1989-01-01

    A study has been made of charge and discharge voltage changes with cycling of Ni/H2 cells containing electrolytes of various KOH concentrations. A study has also been made of electrochemical behavior of the nickel electrodes from the cycled Ni/H2 cells as a function of overcharge amounts. Discharge voltages depressed gradually with cycling for cells having high KOH concentrations (31 to 36 percent), but the voltages increased for those having low KOH concentrations (21 to 26 percent). To determine if there was a crystallographic change of the active material due to cycling, electrochemical behavior of nickel electrodes was studied in an electrolyte flooded cell containing either 31 or 26 percent KOH electrolyte as a function of the amount of overcharge. The changes in discharge voltage appear to indicate crystal structure changes of active material from gamma-phase to beta-phase in low KOH concentrations, and vice versa in high KOH concentration.

  5. Effect of KOH concentration on LEO cycle life of IPV nickel-hydrogen flight battery cells

    Science.gov (United States)

    Smithrick, John J.; Hall, Stephen W.

    1990-01-01

    A breakthrough in the low-earth-orbit (LEO) cycle life of individual pressure vessel (IPV) nickel hydrogen battery cells is reported. The cycle life of boiler plate cells containing 26 percent potassium hydroxide (KOH) electrolyte was about 40,000 LEO cycles compared to 3500 cycles for cells containing 31 percent KOH. The effect of KOH concentration on cycle life was studied. The cycle regime was a stressful accelerated LEO, which consisted of a 27.5 min charge followed by a 17.5 min charge (2 x normal rate). The depth of discharge (DOD) was 80 percent. The cell temperature was maintained at 23 C. The next step is to validate these results using flight hardware and real time LEO test. NASA Lewis has a contract with the Naval Weapons Support Center (NWSC), Crane, Indiana to validate the boiler plate test results. Six 48 A-hr Hughes recirculation design IPV nickel-hydrogen flight battery cells are being evaluated. Three of the cells contain 26 percent KOH (test cells) and three contain 31 percent KOH (control cells). They are undergoing real time LEO cycle life testing. The cycle regime is a 90-min LEO orbit consisting of a 54-min charge followed by a 36-min discharge. The depth-of-discharge is 80 percent. The cell temperature is maintained at 10 C. The cells were cycled for over 8000 cycles in the continuing test. There were no failures for the cells containing 26 percent KOH. There were two failures, however, for the cells containing 31 percent KOH.

  6. KOH concentration effect on the cycle life of nickel-hydrogen cells. IV - Results of failure analysis

    Science.gov (United States)

    Lim, H. S.; Verzwyvelt, S. A.

    1990-01-01

    Potassium hydroxide concentration effects on the cycle life of a Ni/H2 cell have been studied by carrying out a cycle life test on ten Ni/H2 boiler plate cells which contain electrolytes of various KOH concentrations. Failure analyses of these cells were carried out after completion of the life test, which accumulated up to 40,000 cycles at an 80-percent depth of discharge over a period of 3.7 years. These failure analyses included studies on changes of electrical characteristics of test cells, and component analyses after disassembly of the cell. The component analyses included visual inspections, dimensional changes, capacity measurements of nickel electrodes, scanning electron microscopy, surface area measurements, and chemical analyses. Results have indicated that failure mode and change in the nickel electrode varied as the concentration was varied, especially when the concentration was changed from 31 percent or higher to 26 percent or lower.

  7. KOH concentration effect on the cycle life of nickel-hydrogen cells. Part 4: Results of failure analyses

    Science.gov (United States)

    Lim, H. S.; Verzwyvelt, S. A.

    1989-01-01

    KOH concentration effects on cycle life of a Ni/H2 cell have been studied by carrying out a cycle life test of ten Ni/H2 boiler plate cells which contain electrolytes of various KOH concentrations. Failure analyses of these cells were carried out after completion of the life test which accumulated up to 40,000 cycles at an 80 percent depth of discharge over a period of 3.7 years. These failure analyses included studies on changes of electrical characteristics of test cells and component analyses after disassembly of the cell. The component analyses included visual inspections, dimensional changes, capacity measurements of nickel electrodes, scanning electron microscopy, BET surface area measurements, and chemical analyses. Results have indicated that failure mode and change in the nickel electrode varied as the concentration was varied, especially, when the concentration was changed from 31 percent or higher to 26 percent or lower.

  8. Effect of CTAB concentration on synthesis of nickel doped manganese oxide nanoparticles

    Science.gov (United States)

    Shobana, R.; Saravanakumar, B.; Ravi, G.; Yuvakkumar, R.

    2018-05-01

    In this work the effect of concentration of cetyltrimethylammonium bromide (CTAB) in the synthesis of Nickel doped Manganese oxide (Ni-MnO2) nanoparticles have been carried out by adopting the sol-gel process. The synthesized products were characterized by XRD, Infra- Red (FTIR) and SEM analysis. The XRD confirms the formation of Ni-MnO2 nanoparticles illustrate peak at 31.4° with lattice plane (-231). The IR spectra correspond to the peak at 592 and 846 cm-1 attributed to the characteristics peak for Ni-MnO2 nanoparticles. The SEM images for all three Ni-MnO2 nanoparticles for different concentration of CTAB allows us to assess the formation route of nano tentacles from 10 mM, 30 mM and 50 mM. The configured nano tentacles of Ni-MnO2 nanoparticles presumably leads to more significantly change its properties, particularly in its electrochemical properties show the ways to be suitable candidates for supercapacitor, battery, photo catalytic and fuel cell applications.

  9. Effect of nickel chloride on hepatic lipid peroxidation and glutathione concentration in mice

    DEFF Research Database (Denmark)

    Andersen, H R; Andersen, O

    1989-01-01

    Intraperitoneal administration of nickel chloride enhanced hepatic lipid peroxidation (HLP) in 6-wk-old and 8-12-wk-old male CBA-mice but not in 3-wk-old mice. Nickel chloride administration depleted hepatic GSH in 8-12-wk-old mice but not in the younger age groups. After 300 mumol NiCl2/kg...

  10. Does airborne nickel exposure induce nickel sensitization?

    Science.gov (United States)

    Mann, Eugen; Ranft, Ulrich; Eberwein, Georg; Gladtke, Dieter; Sugiri, Dorothee; Behrendt, Heidrun; Ring, Johannes; Schäfer, Torsten; Begerow, Jutta; Wittsiepe, Jürgen; Krämer, Ursula; Wilhelm, Michael

    2010-06-01

    Nickel is one of the most prevalent causes of contact allergy in the general population. This study focuses on human exposure to airborne nickel and its potential to induce allergic sensitization. The study group consisted of 309 children at school-starter age living in the West of Germany in the vicinity of two industrial sources and in a rural town without nearby point sources of nickel. An exposure assessment of nickel in ambient air was available for children in the Ruhr district using routinely monitored ambient air quality data and dispersion modelling. Internal nickel exposure was assessed by nickel concentrations in morning urine samples of the children. The observed nickel sensitization prevalence rates varied between 12.6% and 30.7%. Statistically significant associations were showed between exposure to nickel in ambient air and urinary nickel concentration as well as between urinary nickel concentration and nickel sensitization. Furthermore, an elevated prevalence of nickel sensitization was associated with exposure to increased nickel concentrations in ambient air. The observed associations support the assumption that inhaled nickel in ambient air might be a risk factor for nickel sensitization; further studies in larger collectives are necessary.

  11. Root based responses account for Psidium guajava survival at high nickel concentration.

    Science.gov (United States)

    Bazihizina, Nadia; Redwan, Mirvat; Taiti, Cosimo; Giordano, Cristiana; Monetti, Emanuela; Masi, Elisa; Azzarello, Elisa; Mancuso, Stefano

    2015-02-01

    The presence of Psidium guajava in polluted environments has been reported in recent studies, suggesting that this species has a high tolerance to the metal stress. The present study aims at a physiological characterization of P. guajava response to high nickel (Ni) concentrations in the root-zone. Three hydroponic experiments were carried out to characterize the effects of toxic Ni concentrations on morphological and physiological parameters of P. guajava, focusing on Ni-induced damages at the root-level and root ion fluxes. With up to 300μM NiSO4 in the root-zone, plant growth was similar to that in control plants, whereas at concentrations higher than 1000μM NiSO4 there was a progressive decline in plant growth and leaf gas exchange parameters; this occurred despite, at all considered concentrations, plants limited Ni(2+) translocation to the shoot, therefore avoiding shoot Ni(2+) toxicity symptoms. Maintenance of plant growth with 300μM Ni(2+) was associated with the ability to retain K(+) in the roots meanwhile 1000 and 3000μM NiSO4 led to substantial K(+) losses. In this study, root responses mirror all plant performances suggesting a direct link between root functionality and Ni(2+) tolerance mechanisms and plant survival. Considering that Ni was mainly accumulated in the root system, the potential use of P. guajava for Ni(2+) phytoextraction in metal-polluted soils is limited; nevertheless, the observed physiological changes indicate a good Ni(2+) tolerance up to 300μM NiSO4 suggesting a potential role for the phytostabilization of polluted soils. Copyright © 2014 Elsevier GmbH. All rights reserved.

  12. In situ oxidation state profiling of nickel hexacyanoferrate derivatized electrodes using line-imaging Raman spectroscopy and multivariate calibration

    International Nuclear Information System (INIS)

    Haight, S.M.; Schwartz, D.T.

    1999-01-01

    Metal hexacyanoferrate compounds show promise as electrochemically switchable ion exchange materials for use in the cleanup of radioactive wastes such as those found in storage basins and underground tanks at the Department of Energy's Hanford Nuclear Reservation. Reported is the use of line-imaging Raman spectroscopy for the in situ determination of oxidation state profiles in nickel hexacyanoferrate derivatized electrodes under potential control in an electrochemical cell. Line-imaging Raman spectroscopy is used to collect 256 contiguous Raman spectra every ∼5 microm from thin films (ca. 80 nm) formed by electrochemical derivatization of nickel electrodes. The cyanide stretching region of the Raman spectrum of the film is shown to be sensitive to iron oxidation state and is modeled by both univariate and multivariate correlations. Although both correlations fit the calibration set well, the multivariate (principle component regression or PCR) model's predictions of oxidation state are less sensitive to noise in the spectrum, yielding a much smoother oxidation state profile than the univariate model. Oxidation state profiles with spatial resolution of approximately 5 microm are shown for a nickel hexacyanoferrate derivatized electrode in reduced, intermediate, and oxidized states. In situ oxidation state profiles indicate that the 647.1 nm laser illumination photo-oxidizes the derivatized electrodes. This observation is confirmed using photoelectrochemical methods

  13. Seasonal variation in diurnal atmospheric grass pollen concentration profiles

    DEFF Research Database (Denmark)

    Peel, Robert George; Ørby, Pia Viuf; Skjøth, Carsten Ambelas

    2014-01-01

    the time of day when peak concentrations are most likely to occur using seasonally averaged diurnal profiles. Atmospheric pollen loads are highly dependent upon emissions, and different species of grass are known to flower and emit pollen at different times of the day and during different periods......In this study, the diurnal atmospheric grass pollen concentration profile within the Danish city of Aarhus was shown to change in a systematic manner as the pollen season progressed. Although diurnal grass pollen profiles can differ greatly from day-to-day, it is common practice to establish...... of the pollen season. Pollen concentrations are also influenced by meteorological factors - directly through those parameters that govern pollen dispersion and transport, and indirectly through the weather-driven flowering process. We found that three different profiles dominated the grass pollen season...

  14. Validation of predicted exponential concentration profiles of chemicals in soils

    International Nuclear Information System (INIS)

    Hollander, Anne; Baijens, Iris; Ragas, Ad; Huijbregts, Mark; Meent, Dik van de

    2007-01-01

    Multimedia mass balance models assume well-mixed homogeneous compartments. Particularly for soils, this does not correspond to reality, which results in potentially large uncertainties in estimates of transport fluxes from soils. A theoretically expected exponential decrease model of chemical concentrations with depth has been proposed, but hardly tested against empirical data. In this paper, we explored the correspondence between theoretically predicted soil concentration profiles and 84 field measured profiles. In most cases, chemical concentrations in soils appear to decline exponentially with depth, and values for the chemical specific soil penetration depth (d p ) are predicted within one order of magnitude. Over all, the reliability of multimedia models will improve when they account for depth-dependent soil concentrations, so we recommend to take into account the described theoretical exponential decrease model of chemical concentrations with depth in chemical fate studies. In this model the d p -values should estimated be either based on local conditions or on a fixed d p -value, which we recommend to be 10 cm for chemicals with a log K ow > 3. - Multimedia mass model predictions will improve when taking into account depth dependent soil concentrations

  15. Phytotoxic effects of nickel on yield and concentration of macro- and micro-nutrients in sunflower (Helianthus annuus L.) achenes.

    Science.gov (United States)

    Ahmad, Muhammad Sajid Aqeel; Ashraf, Muhammad; Hussain, Mumtaz

    2011-01-30

    The phytotoxic effects of varying levels of nickel (0, 10, 20, 30, and 40 mg L(-1)) on growth, yield and accumulation of macro- and micro-nutrients in leaves and achenes of sunflower (Helianthus annuus L.) were appraised in this study. A marked reduction in root and shoot fresh biomass was recorded at higher Ni levels. Nickel stress also caused a substantial decrease in all macro- and micro-nutrients in leaves and achenes. The lower level of Ni (10 mg L(-1)) had a non-significant effect on various yield attributes, but higher Ni levels considerably decreased these parameters. Higher Ni levels decreased the concentrations of Ca, Mn and Fe in achenes. In contrast, achene N, K, Zn, Mn and Cu decreased consistently with increasing level of Ni, even at lower level (10 mg L(-1)). Sunflower hybrid Hysun-33 had better yield and higher most of the nutrients in achenes as compared with SF-187. The maximum reduction in all parameters was observed at the maximum level of nickel (40 mg L(-1)) where almost all parameters were reduced more than 50% of those of control plants. In conclusion, the pattern of uptake and accumulation of different nutrients in sunflower plants were nutrient- and cultivar-specific under Ni-stress. Copyright © 2010 Elsevier B.V. All rights reserved.

  16. Factors that influence an elemental depth concentration profile

    International Nuclear Information System (INIS)

    McHugh, J.A.

    1975-01-01

    The use of secondary ion mass spectrometry in concentration profiling is discussed. Two classes of factors that influence an elemental concentration profile are instrumental effects and ion-matrix effects. Instrumental factors that must be considered are: (1) uniformity of the primary ion current density, (2) constancy of the primary ion current, (3) redeposition, (4) memory, (5) primary ion beam tailing and the nonfocused component, (6) chemical purity of the primary ion beam, and (7) residual gas impurities. Factors which can be classified as ion matrix effects are: (1) the mean escape depth of secondary ions, (2) recoil implantation, (3) molecular ion interferences, (4) primary ion beam induced diffusion of matrix species, (5) nonuniform sputter removal of matrix layers, and (6) implanted primary ion chemical and lattice damage effects

  17. Ionization rates and profiles of electron concentration in Martian atmosphere

    International Nuclear Information System (INIS)

    Komitov, B.; Spasov, S.; Gogoshev, M.

    1981-01-01

    The ionization and vertical profiles of electron concentration in the Martian atmosphere are calculated as functions of the solar zenith angles varying from O deg to 90 deg. A neutral atmospheric model based on direct mass-spectometric measurements from the Viking-1 landing modul is employed in the calculation. The Earth data of the ionization solar flux at the same level of the solar activity and for the month of the Viking-1 measurements reduced for the Mars orbit are used. The numerical result for the photoionization rates and quasi-equilibrium electron-concentration profiles in the upper Martian atmosphere at different solar zenith angles from 0 deg to 100 deg are presented. It is shown that the maxima of both quantities decrease and move towards the upper atmosphere regions. The calculated electron density at the zenith solar angle of 40 deg are compared to Viking-1 experimental data and a good agreement is achieved

  18. Capacity of the aquatic fern (Salvinia minima Baker) to accumulate high concentrations of nickel in its tissues, and its effect on plant physiological processes

    Energy Technology Data Exchange (ETDEWEB)

    Fuentes, Ignacio I.; Espadas-Gil, Francisco; Talavera-May, Carlos; Fuentes, Gabriela; Santamaría, Jorge M., E-mail: jorgesm@cicy.mx

    2014-10-15

    Highlights: • We document the capacity of an aquatic fern to hyper-accumulate Ni. • Effects of high Ni concentrations uptake on plant performance is documented. • High concentration of Ni in tissues damage photosynthesis. • Damage is related to carboxylation mechanisms than to electron transfer efficiency. • S. minima is a good candidate for remediation of water bodies contaminated with Ni. - Abstract: An experiment was designed to assess the capacity of Salvinia minima Baker to uptake and accumulate nickel in its tissues and to evaluate whether or not this uptake can affect its physiology. Our results suggest that S. minima plants are able to take up high amounts of nickel in its tissues, particularly in roots. In fact, our results support the idea that S. minima might be considered a hyper-accumulator of nickel, as it is able to accumulate 16.3 mg g{sup −1} (whole plant DW basis). Our results also showed a two-steps uptake pattern of nickel, with a fast uptake of nickel at the first 6 to 12 h of being expose to the metal, followed by a slow take up phase until the end of the experiment at 144 h. S. minima thus, may be considered as a fern useful in the phytoremediation of residual water bodies contaminated with this metal. Also from our results, S. minima can tolerate fair concentrations of the metal; however, at concentrations higher than 80 μM Ni (1.5 mg g{sup −1} internal nickel concentration), its physiological performance can be affected. For instance, the integrity of cell membranes was affected as the metal concentration and exposure time increased. The accumulation of high concentrations of internal nickel did also affect photosynthesis, the efficiency of PSII, and the concentration of photosynthetic pigments, although at a lower extent.

  19. X-ray investigation of fatigued nickel monocrystals by an analysis of diffraction line profiles

    International Nuclear Information System (INIS)

    Schmidt, G.K.

    1988-01-01

    Using a statistics of the inhomogeneous plastic deformation of a fatigued FCC monocrystal it may be possible to analyse the intensity distributions of the X-ray reflections of this crystal with regard to the fatigue phenomena. The results of an X-ray investigation of a fatigued nickel monocrystal are desribed. 3 refs.; 1 figure; 1 table

  20. Corrosion of nickel and stainless steels in concentrated lithium hydroxide solutions

    International Nuclear Information System (INIS)

    Graydon, J.W.; Kirk, D.W.

    1990-06-01

    The corrosion behaviour of four alloys in 3 and 5 mol/L lithium hydroxide solutions under a hydrogen atmosphere at 95 degrees C was investigated. Corrosion of Nickel 200 and the stainless steels 316, 316L, and E-Brite 26-1 was assessed in two sets of immersion tests lasting 10 and 136 days. Corrosion rates were determined by weight loss, susceptibility to stress corrosion cracking was evaluated using U-bends, and the details of the corrosion process were studied on specimens with a mirror finish using light and electron microscopy, x-ray spectrometry and mapping, and x-ray diffraction. The long term corrosion rates were low for all alloys ( 2 , β-LiFeO 2 , and a very iron-rich β-LiFe 5 0 8 . The passivating layer on the nickel was Ni(OH) 2 . The underlying metal corroded evenly except for the 316 stainless steels. These showed a uniform intergranular corrosion with minor drop-out of smaller grains likely because of segregation of impurities to the grain boundaries. The walls of these intergranular crevices were covered with a passivating layer of chromium oxide. (8 figs., 5 tabs., 11 refs.)

  1. Effect of KOH concentration on LEO cycle life of IPV nickel-hydrogen flight cells-update 2

    Science.gov (United States)

    Smithrick, John J.; Hall, Stephen W.

    1991-01-01

    An update of validation test results confirming the breakthrough in low earth orbit (LEO) cycle life of nickel-hydrogen cells containing 26 percent KOH electrolyte is presented. A breakthrough in the LEO cycle life of individual pressure vessel (IPV nickel-hydrogen cells has been previously reported. The cycle life of boiler plate cells containing 26 percent potassium hydroxide (KOH) electrolyte was about 40 000 LEO cycles compared to 3500 cycles for cells containing 31 percent KOH. This test was conducted at Hughes Aircraft Company under a NASA Lewis contract. The purpose was to investigate the effect of KOH concentration on cycle life. The cycle regime was a stressful accelerated LEO, which consisted of a 27.5 min charge followed by a 17.5 min discharge (2x normal rate). The depth of discharge (DOD) was 80 percent. The cell temperature was maintained at 23 C. The boiler plate test results are in the process of being validated using flight hardware and real time LEO test at the Naval Weapons Support Center (NWSC), Crane, Indiana under a NASA Lewis Contract. Six 48 Ah Hughes recirculation design IPV nickel-hydrogen flight battery cells are being evaluated. Three of the cells contain 26 percent KOH (test cells), and three contain 31 percent KOH (control cells). They are undergoing real time LEO cycle life testing. The cycle regime is a 90-min LEO orbit consisting of a 54-min charge followed by a 36-min discharge. The depth-of-discharge is 80 percent. The cell temperature is maintained at 10 C. The three 31 percent KOH cells failed (cycles 3729, 4165, and 11355). One of the 26 percent KOH cells failed at cycle 15314. The other two 26 percent KOH cells were cycled for over 16600 cycles during the continuing test.

  2. Changes in the concentrations of phenolics and photosynthates in Scots pine (Pinus sylvestris L.) seedlings exposed to nickel and copper

    Energy Technology Data Exchange (ETDEWEB)

    Roitto, M. [MTT Agrifood Research Finland, Environmental Research, Karilantie 2A, FIN-50600 Mikkeli (Finland) and Department of Ecological and Environmental Sciences, University of Helsinki, Niemenkatu 73, FIN-15140 Lahti (Finland)]. E-mail: marja.roitto@mtt.fi; Rautio, P. [Finnish Forest Research Institute, Parkano Research Station, Kaironiementie 54, FIN-39700 Parkano (Finland); Julkunen-Tiitto, R. [Department of Biology, University of Joensuu, PO Box 111, FIN-80101 Joensuu (Finland); Kukkola, E. [University of Helsinki, Department of Biosciences, Division of Plant Physiology, PO Box 56, FIN-00014, Helsinki (Finland); Huttunen, S. [Department of Biology, University of Oulu, PO Box 3000, FIN-90014 Oulu (Finland)

    2005-10-15

    Studies were done on the effects of elevated soil concentrations of copper (Cu) and (Ni) on foliar carbohydrates and phenolics in Scots pine (Pinus sylvestris L.). Four year-old seedlings were planted in pots filled with metal-treated mineral forest soil in early June. The experimental design included all combinations of four levels of Cu (0, 25, 40 and 50 mg kg{sup -1} soil dw) and Ni (0, 5, 15 and 25 mg kg{sup -1} soil dw). Current year needles were sampled for soluble sugar, starch and phenolics at the end of September. Ni increased sucrose concentration in the needles, indicating disturbances in carbohydrate metabolism. Trees exposed to Ni had higher concentrations of condensed tannins compared with controls. In contrast, concentrations of several other phenolic compounds decreased when seedlings were exposed to high levels of Cu or to a combination of Ni and Cu. The results suggest that concentrations of phenolics in Scots pine needles vary in their responses to Ni and Cu in the forest soil. - Excess nickel in soil interferes with carbohydrate metabolism and induces an increase in concentration of condensed tannins in Scots pine needles.

  3. Changes in the concentrations of phenolics and photosynthates in Scots pine (Pinus sylvestris L.) seedlings exposed to nickel and copper

    International Nuclear Information System (INIS)

    Roitto, M.; Rautio, P.; Julkunen-Tiitto, R.; Kukkola, E.; Huttunen, S.

    2005-01-01

    Studies were done on the effects of elevated soil concentrations of copper (Cu) and (Ni) on foliar carbohydrates and phenolics in Scots pine (Pinus sylvestris L.). Four year-old seedlings were planted in pots filled with metal-treated mineral forest soil in early June. The experimental design included all combinations of four levels of Cu (0, 25, 40 and 50 mg kg -1 soil dw) and Ni (0, 5, 15 and 25 mg kg -1 soil dw). Current year needles were sampled for soluble sugar, starch and phenolics at the end of September. Ni increased sucrose concentration in the needles, indicating disturbances in carbohydrate metabolism. Trees exposed to Ni had higher concentrations of condensed tannins compared with controls. In contrast, concentrations of several other phenolic compounds decreased when seedlings were exposed to high levels of Cu or to a combination of Ni and Cu. The results suggest that concentrations of phenolics in Scots pine needles vary in their responses to Ni and Cu in the forest soil. - Excess nickel in soil interferes with carbohydrate metabolism and induces an increase in concentration of condensed tannins in Scots pine needles

  4. Sources of variation in concentrations of nickel and copper in mountain birch foliage near a nickel-copper smelter at Monchegorsk, north-western Russia: results of long-term monitoring

    International Nuclear Information System (INIS)

    Kozlov, Mikhail V.

    2005-01-01

    Concentrations of nickel and copper, two principal metal pollutants of the 'Severonikel' smelter at Monchegorsk, NW Russia, were measured in unwashed leaves of mountain birch, Betula pubescens subsp. czerepanovii, collected in eight study sites along the pollution gradient during 1991-2003. In spite of significant decline in metal emissions, concentrations of foliar metals in most of the study sites did not decrease, indicating that soil contamination remains extremely high. Multiyear mean values peaked at 6.6 km S of the smelter, where they were 20-25 times higher than in the most distant study site. Concentrations of both metals demonstrated pronounced annual variation, which was explained by the meteorological conditions of early summer: higher precipitation in May increased foliar concentrations of both metals, whereas higher precipitation in June resulted in lower foliar concentrations of nickel. These data suggest that ecotoxicological situation in metal-contaminated areas can be modified by the expected climate change. In heavily polluted sites individual birch trees generally retained their ranks in terms of metal contamination during 1995-2003, demonstrating that the use of the same set of trees can significantly increase the accuracy of the monitoring data. - Foliar concentrations of nickel and copper did not reflect emission decline during 1991-2003; annual variation was explained by weather conditions

  5. Hydrogen concentration profiles and chemical bonding in silicon nitride

    International Nuclear Information System (INIS)

    Peercy, P.S.; Stein, H.J.; Doyle, B.L.; Picraux, S.T.

    1978-01-01

    The complementary technique of nuclear reaction analysis and infrared absorption were used to study the concentration profile and chemical bonding of hydrogen in silicon nitride for different preparation and annealing conditions. Silicon nitride prepared by chemical vapor deposition from ammonia-silane mixtures is shown to have hydrogen concentrations of 8.1 and 6.5 at.% for deposition temperatures of 750 and 900 0 C, respectively. Plasma deposition at 300 0 C from these gases results in hydrogen concentrations of approximately 22 at.%. Comparison of nuclear reaction analysis and infrared absorption measurements after isothermal annealing shows that all of the hydrogen retained in the films remains bonded to either silicon or nitrogen and that hydrogen release from the material on annealing is governed by various trap energies involving at least two N-H and one Si-H trap. Reasonable estimates of the hydrogen release rates can be made from the effective diffusion coefficient obtained from measurements of hydrogen migration in hydrogen implanted and annealed films

  6. Exhaled methane concentration profiles during exercise on an ergometer

    Science.gov (United States)

    Szabó, A; Ruzsanyi, V; Unterkofler, K; Mohácsi, Á; Tuboly, E; Boros, M; Szabó, G; Hinterhuber, H; Amann, A

    2016-01-01

    Exhaled methane concentration measurements are extensively used in medical investigation of certain gastrointestinal conditions. However, the dynamics of endogenous methane release is largely unknown. Breath methane profiles during ergometer tests were measured by means of a photoacoustic spectroscopy based sensor. Five methane-producing volunteers (with exhaled methane level being at least 1 ppm higher than room air) were measured. The experimental protocol consisted of 5 min rest—15 min pedalling (at a workload of 75 W)—5 min rest. In addition, hemodynamic and respiratory parameters were determined and compared to the estimated alveolar methane concentration. The alveolar breath methane level decreased considerably, by a factor of 3–4 within 1.5 min, while the estimated ventilation-perfusion ratio increased by a factor of 2–3. Mean pre-exercise and exercise methane concentrations were 11.4 ppm (SD:7.3) and 2.8 ppm (SD:1.9), respectively. The changes can be described by the high sensitivity of exhaled methane to ventilationperfusion ratio and are in line with the Farhi equation. PMID:25749807

  7. Nickel Dermatitis - Nickel Excretion

    DEFF Research Database (Denmark)

    Menné, T.; Thorboe, A.

    1976-01-01

    Nickel excretion in urine in four females -sensitive to nickel with an intermittent dyshidrotic eruption was measured with flameless atomic absorption. Excretion of nickel was found to be increased in association with outbreaks of vesicles. The results support the idea that the chronic condition ...

  8. Nickel allergy

    DEFF Research Database (Denmark)

    Fischer, L A; Johansen, J D; Menné, T

    2007-01-01

    BACKGROUND: The frequency of nickel allergy varies between different population groups. Exposure regulation has proven effective in decreasing the frequency. Experimental studies with other allergens have shown a significant relation between patch test reactivity and repeated open application test...... in a patch test and a dilution series of three concentrations in a ROAT, with duration of up to 21 days. Eighteen persons with no nickel allergy were included as control group for the ROAT. RESULTS: The predicted dose which will elicit a reaction in 10% of allergic individuals was calculated to be 0......-response; indeed, there was no statistically significant difference. CONCLUSIONS: For elicitation of nickel allergy the elicitation threshold for the patch test is higher than the elicitation threshold (per application) for the ROAT, but is approximately the same as the accumulated elicitation threshold...

  9. Blood cadmium concentration and lipid profile in Korean adults

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kisok [Department of Public Health, Keimyung University, 1000 Shindang-dong, Daegu 704-701 (Korea, Republic of)

    2012-01-15

    Although animal experiments have shown that cadmium exposure induces alterations in lipid profiles, no epidemiological study of this relationship has been performed. The objective of this study was to evaluate the association between blood cadmium concentration and blood lipid levels in Korean adults. A cross-sectional study comprising participants (n=3903) aged 20 years or older from the 2005, 2008, and 2009 Korea National Health and Nutrition Examination Surveys was conducted. Demographic characteristics and dietary intake were obtained from the participants by questionnaire, and cadmium and lipid levels were determined by analysis of blood samples. After adjusting for demographic and dietary factors, blood concentration of cadmium was positively associated with the risk of low high-density lipoprotein cholesterol (HDL-C) in a dose-dependent manner (p for trend <0.001). In addition, the odds ratios (ORs) of a high triglyceride to HDL-C ratio was significantly increased in the high blood cadmium groups [OR=1.36; 95% confidence interval (CI), 1.03-1.79 for fourth quintile and OR=1.41; 95% CI, 1.07-1.86 for fifth quintile] compared with the lowest quintile group. However, high blood cadmium was not associated with a risk of high total cholesterol, high low-density lipoprotein cholesterol, or high triglycerides. These data suggest that an increased cadmium body burden increases the risk of dyslipidemia, mainly due to the increased risk of low HDL-C and the high ratio of triglycerides to HDL-C.

  10. Lead, Nickel and Copper Concentration and Related Factors in Some Uncooked Vegetables Irrigated by Wastewater

    Directory of Open Access Journals (Sweden)

    Dilshad Ganjo Ahmad

    2012-07-01

    Full Text Available Population density of Erbil City, Northern Iraq (where this work was carried out estimated as more than 2 million. The sewage discharge of the city may reach 77760m3/ day during low level and 108000m3/ day during high-level periods. About 225 hectares of scattered farmlands are used by local farmers for production of uncooked vegetables for local need, all of which are irrigated by untreated sewage water. In the present work, about 28 physical and chemical variables those related to sewage water quality were assessed on fortnightly bases for 7 months. Some toxic heavy metals, namely; Pb, Ni and Cu bioaccumulation rates in sewage, soil and some uncooked vegetables in five different locations/ farms were followed up (only bioaccumulation rates of Pb, Ni and Cu in lettuce, cress, dill and radish are given here (Full data can be obtained from both authors. Onset results revealed that Pb, Ni and Cu bioaccumulation rates calculated for lettuce, cress, dill and radish were surpassed maximum permissible levels (MPL. However, the bioaccumulation ranges calculated for lettuce, cress, dill and radish respectively were; lead (3.01-6.72mg/ kg/ dwt, (3.03-6.52mg/ kg/ dwt, (0.48-2.74mg/ kg/ dwt and (0.41-3.00mg/ kg/ dwt; nickel (1.01-3.92mg/ kg/ dwt, (4.03-7.99mg/ kg/ dwt, (0.37-3.98mg/ kg/ dwt and (1.00-3.95mg/ kg/ dwt and copper (8.02-15.26mg/ kg/ dwt, (7.20-13.62mg/ kg/ dwt,(6.35-10.37mg/ kg/ dwt, (2.01-5.94mg/ kg/ dwt. The studied vegetables were showed different modes concerning heavy metal accumulation rates.

  11. Electroless nickel plating on abs plastics from nickel chloride and nickel sulfate baths

    International Nuclear Information System (INIS)

    Inam-ul-haque; Ahmad, S.; Khan, A.

    2005-01-01

    Aqueous acid nickel chloride and alkaline nickel sulphate bath were studied for electroless nickel planting on acrylonitrile-butadiene-styrene (ABS) plastic. Before electroless nickel plating, specimens were etched, sensitized and activated. Effects of sodium hypophosphite and sodium citrate concentration on the electroless nickel plating thickness were discussed. Aqueous acid nickel chloride bath comprising, nickel chloride 10 g/L, sodium hypophosphite 40 g/L, sodium citrate 40g/L at pH 5.5, temperature 85 deg. C and density of 1 Be/ for thirty minutes gave best coating thickness in micrometer. It was found that acid nickel chloride bath had a greater stability, wide operating range and better coating thickness results than alkaline nickel sulphate bath. Acid nickel chloride bath gave better coating thickness than alkaline nickel sulfate bath

  12. A comparison of instrumentation using Naviflex and Profile nickel-titanium engine-driven rotary instruments.

    Science.gov (United States)

    Ottosen, S R; Nicholls, J I; Steiner, J C

    1999-06-01

    This study was designed to compare the changes in canal configuration resulting from instrumentation by either Profile or Naviflex instruments. Forty mesial canals in extracted human molar teeth were embedded and sectioned at two root levels. Reassembled teeth were instrumented with a modified crown-down technique as described in the Profile training video for Profile files and in a similar manner for Naviflex instruments. Superimposed pre- and postinstrumented cross-sectional root images were projected, traced, and scanned into a computer for analysis. Canal movement, in relation to the furca, and canal area change were recorded. The results showed no significant difference in canal center movement or canal area change between the Profile or Naviflex groups. The degree of canal curvature had no effect on canal center movement or canal area change.

  13. Blood cadmium concentration and lipid profile in Korean adults

    International Nuclear Information System (INIS)

    Kim, Kisok

    2012-01-01

    Although animal experiments have shown that cadmium exposure induces alterations in lipid profiles, no epidemiological study of this relationship has been performed. The objective of this study was to evaluate the association between blood cadmium concentration and blood lipid levels in Korean adults. A cross-sectional study comprising participants (n=3903) aged 20 years or older from the 2005, 2008, and 2009 Korea National Health and Nutrition Examination Surveys was conducted. Demographic characteristics and dietary intake were obtained from the participants by questionnaire, and cadmium and lipid levels were determined by analysis of blood samples. After adjusting for demographic and dietary factors, blood concentration of cadmium was positively associated with the risk of low high-density lipoprotein cholesterol (HDL-C) in a dose-dependent manner (p for trend <0.001). In addition, the odds ratios (ORs) of a high triglyceride to HDL-C ratio was significantly increased in the high blood cadmium groups [OR=1.36; 95% confidence interval (CI), 1.03–1.79 for fourth quintile and OR=1.41; 95% CI, 1.07–1.86 for fifth quintile] compared with the lowest quintile group. However, high blood cadmium was not associated with a risk of high total cholesterol, high low-density lipoprotein cholesterol, or high triglycerides. These data suggest that an increased cadmium body burden increases the risk of dyslipidemia, mainly due to the increased risk of low HDL-C and the high ratio of triglycerides to HDL-C.

  14. ProFile Vortex and Vortex Blue Nickel-Titanium Rotary Instruments after Clinical Use.

    Science.gov (United States)

    Shen, Ya; Zhou, Huimin; Coil, Jeffrey M; Aljazaeri, Bassim; Buttar, Rene; Wang, Zhejun; Zheng, Yu-feng; Haapasalo, Markus

    2015-06-01

    The aim of this study was to analyze the incidence and mode of ProFile Vortex and Vortex Blue instrument defects after clinical use in a graduate endodontic program and to examine the impact of clinical use on the instruments' metallurgical properties. A total of 330 ProFile Vortex and 1136 Vortex Blue instruments from the graduate program were collected after each had been used in 3 teeth. The incidence and type of instrument defects were analyzed. The lateral surfaces and fracture surfaces of the fractured files were examined by using scanning electron microscopy. Unused and used instruments were examined by full and partial differential scanning calorimetry. No fractures were observed in the 330 ProFile Vortex instruments, whereas 20 (6.1%) revealed bent or blunt defects. Only 2 of the 1136 Vortex Blue files fractured during clinical use. The cause of fracture was shear stress. The fractures occurred at the tip end of the spirals. Only 1.8% (21 of 1136) of the Vortex Blue files had blunt tips. Austenite-finish temperatures were very similar for unused and used ProFile Vortex files and were all greater than 50°C. The austenite-finish temperatures of used and unused Vortex Blue files (38.5°C) were lower than those in ProFile Vortex instruments (P Vortex Blue files had an obvious 2-stage transformation, martensite-to-R phase and R-to-austenite phase. The trends of differential scanning calorimetry plots of unused Vortex Blue instruments and clinically used instruments were very similar. The risk of ProFile Vortex and Vortex Blue instrument fracture is very low when instruments are discarded after clinical use in the graduate endodontic program. The Vortex Blue files have metallurgical behavior different from ProFile Vortex instruments. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  15. Zeolite-filled silicone rubber membranes. Experimental determination of concentration profiles

    NARCIS (Netherlands)

    te Hennepe, H.J.C.; Boswerger, W.B.F.; Bargeman, D.; Bargeman, D.; Mulder, M.H.V.; Smolders, C.A.; Smolders, C.A.

    1994-01-01

    Permeant concentrations in silicalite-filled silicone rubber membranes during pervaporation of propanol/water mixtures were measured using multi-layered membranes. Experimentally determined concentration profiles show that the propanol concentration in the silicalite-filled membrane increases with

  16. The accumulation of nickel in human lungs.

    OpenAIRE

    Edelman, D A; Roggli, V L

    1989-01-01

    Using data from published studies, lung concentrations of nickel were compare for persons with and without occupational exposure to nickel. As expected, the concentrations were much higher for persons with occupational exposure. To estimate the effects of nickel-containing tobacco smoke and nickel in the ambient air on the amount of nickel accumulated in lungs over time, a model was derived that took into account various variables related to the deposition of nickel in lungs. The model predic...

  17. Nickel, Aluminum and Strontium Concentration in Different Samples of Egyptian Foodstuff

    International Nuclear Information System (INIS)

    Abu Khadra, S.A.; Abd El-Fattah, A.T.; Anwar, S.M.

    2003-01-01

    Eight different types of food items, collected from eight Egyptian governorates, were subjected to elemental analysis to determine Ni, Al, and Sr concentration by using Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES). The result indicated that the concentration of Ni, Al and Sr are in range of 0.04-7.31, 0.07-5.56, 0.02-13.4 mg/kg-wet weight respectively. The maximum concentrations of Ni and Al are present in cereals and leafy vegetables while minimum values are present in roots and tubers. Sr concentration showed completely different trend. Its maximum value is present in fish samples. This focuses a very important remark about its active pathway (aquatic ecosystem) to prevent completely the disposal of radioactive Sr in any water body.By knowing the food consumption values by Egyptian, the daily dietary intake of these elements were calculated. The obtained mean values are 1.894, 2.242 and 1.483 mg/d/caput for Ni, Al and Sr respectively. These values are within the reported data and far away from their toxic intake level

  18. Ambient NO2 concentration profiles in Flanders using passive sampling

    Directory of Open Access Journals (Sweden)

    Sanja Potgieter-Vermaak

    2008-09-01

    Full Text Available In most parts of Europe NO2 emissions from excessive road traffic, concentrated by confined spaces and limited dispersion, are often higher than the ambient guideline values. As a pollutant,NO2 has a number of adverse effects on human health and the environment. The European Union sets guideline and threshold values for various pollutants, to protect humans and the environment, of which NO2 is one. Flanders adopted these values as most countries did, and the monitoring and evaluation of the levels against these guideline values are mostly done by VMM (the Flemish Environmental Company. The air quality Framework Directive (96/62/EG was drafted on the27th of September 1996 and instituted on the 21st of November 1996. New guideline values forNO2 will come into effect in 2010 (1999/30/EG. The future hourly guideline value is 200 µg m-3which may not be exceeded more than 18 times in a calendar year. The average annual guideline value must not exceed 40 µg m-3.Currently various pollutants are continuously monitored by means of fixed monster monitors and analysers, where after data is extrapolated to give an overview of the dispersion. In the 2003annual report the future guideline value has been exceeded in 7 locations in Flanders. Moreover, in a separate study it was reported that in various locations with high traffic density and low dispersion, this value was exceeded, even though the dispersion model did not indicate it. Hence, to test these and other locations against the future guideline value a total of 19points, in 6 different cities and towns in Flanders, were chosen to monitor the NO2 profile over a1 year period. Passive sampling, averaged over periods of 2 weeks, was used and comparisons with the fixed monitors in some of these locations were possible. The future annual guideline value of 40 µg m-3 (2010 was exceeded in 11 of the 19 measured locations. When high traffic density was accompanied by low dispersion the value was at its

  19. Mechanism of Na2SO4 Promoting Nickel Extraction from Sulfide Concentrates by Sulfation Roasting-Water Leaching

    Science.gov (United States)

    Li, Guangshi; Cheng, Hongwei; Chen, Sha; Lu, Xionggang; Xu, Qian; Lu, Changyuan

    2018-06-01

    As a more environmentally friendly and energy-efficient route, the sulfation roasting-water leaching technique has been developed for highly effective extraction of non-ferrous metals from nickel sulfide concentrate in the presence of a Na2SO4 additive. The effects of several important roasting parameters—the roasting temperature, the addition of Na2SO4, the holding time, and the heating rate in particular—have been investigated. The results suggest that about 90 pct Ni, 92 pct Co, 95 pct Cu, and leached from the calcine roasted under the optimum conditions. Furthermore, the behavior and mechanism of the Na2SO4 additive in the roasting process have been well addressed by detailed characterization of the roasted product and leaching residue using quantitative phase analysis (QPA) and energy dispersive spectroscopy (EDS) mapping. The Na2SO4 additive was observed to play a noticeable role in promoting the sulfation degree of valuable metals by forming liquid phases [Na2Me(SO4)2] at the outermost layer, which can create a suitable dynamic environment for sulfation. Thus, addition of Na2SO4 might be conducive to an alternative metallurgical process involving complex sulfide ores.

  20. Time- and concentration-dependent genomic responses of the rat airway to inhaled nickel subsulfide

    Energy Technology Data Exchange (ETDEWEB)

    Efremenko, A.Y., E-mail: aefremenko@thehamner.org [The Hamner Institutes for Health Sciences, 6 Davis Drive, Research Triangle Park, NC 27709 (United States); Campbell, J.L.; Dodd, D.E. [The Hamner Institutes for Health Sciences, 6 Davis Drive, Research Triangle Park, NC 27709 (United States); Oller, A.R. [NiPERA, Inc., 2525 Meridian Parkway, Suite 240, Durham, NC 27713 (United States); Clewell, H.J. [The Hamner Institutes for Health Sciences, 6 Davis Drive, Research Triangle Park, NC 27709 (United States)

    2014-09-15

    Objective: To provide insights into the mode of action for Ni{sub 3}S{sub 2} lung carcinogenicity by examining gene expression changes in target cells after inhalation exposure. Methods: Gene expression changes were determined in micro-dissected lung broncho-alveolar cells from Fischer 344 rats following inhalation of Ni{sub 3}S{sub 2} at 0.0, 0.04, 0.08, 0.15, and 0.60 mg/m{sup 3} (0.03, 0.06, 0.11, and 0.44 mg Ni/m{sup 3}) for one and four weeks (6 h/day, 5 days/week). Results: Broncho-alveolar lavage fluid evaluation and lung histopathology provided evidence of inflammation only at the two highest concentrations, which were similar to those tested in the 2-year bioassay. The number of statistically significant up- and down-regulated genes decreased markedly from one to four weeks of exposure, suggesting adaptation. Cell signal pathway enrichment at both time-points primarily reflected responses to toxicity, including inflammatory and proliferative signaling. While proliferative signaling was up-regulated at both time points, some inflammatory signaling reversed from down-regulation at 1 week to up-regulation at 4 weeks. Conclusions: These results support a mode of action for Ni{sub 3}S{sub 2} carcinogenicity driven by chronic toxicity, inflammation and proliferation, leading to mis-replication, rather than by direct genotoxicity. Benchmark dose (BMD) analysis identified the lowest pathway transcriptional BMD exposure concentration as 0.026 mg Ni/m{sup 3}, for apoptosis/survival signaling. When conducted on the basis of lung Ni concentration the lowest pathway BMD was 0.64 μg Ni/g lung, for immune/inflammatory signaling. Implications: These highly conservative BMDs could be used to derive a point of departure in a nonlinear risk assessment for Ni{sub 3}S{sub 2} toxicity and carcinogenicity. - Highlights: • The mode of action for lung carcinogenicity of inhaled Ni{sub 3}S{sub 2} was investigated in rats. • Gene expression changes were determined in micro

  1. Time- and concentration-dependent genomic responses of the rat airway to inhaled nickel subsulfide

    International Nuclear Information System (INIS)

    Efremenko, A.Y.; Campbell, J.L.; Dodd, D.E.; Oller, A.R.; Clewell, H.J.

    2014-01-01

    Objective: To provide insights into the mode of action for Ni 3 S 2 lung carcinogenicity by examining gene expression changes in target cells after inhalation exposure. Methods: Gene expression changes were determined in micro-dissected lung broncho-alveolar cells from Fischer 344 rats following inhalation of Ni 3 S 2 at 0.0, 0.04, 0.08, 0.15, and 0.60 mg/m 3 (0.03, 0.06, 0.11, and 0.44 mg Ni/m 3 ) for one and four weeks (6 h/day, 5 days/week). Results: Broncho-alveolar lavage fluid evaluation and lung histopathology provided evidence of inflammation only at the two highest concentrations, which were similar to those tested in the 2-year bioassay. The number of statistically significant up- and down-regulated genes decreased markedly from one to four weeks of exposure, suggesting adaptation. Cell signal pathway enrichment at both time-points primarily reflected responses to toxicity, including inflammatory and proliferative signaling. While proliferative signaling was up-regulated at both time points, some inflammatory signaling reversed from down-regulation at 1 week to up-regulation at 4 weeks. Conclusions: These results support a mode of action for Ni 3 S 2 carcinogenicity driven by chronic toxicity, inflammation and proliferation, leading to mis-replication, rather than by direct genotoxicity. Benchmark dose (BMD) analysis identified the lowest pathway transcriptional BMD exposure concentration as 0.026 mg Ni/m 3 , for apoptosis/survival signaling. When conducted on the basis of lung Ni concentration the lowest pathway BMD was 0.64 μg Ni/g lung, for immune/inflammatory signaling. Implications: These highly conservative BMDs could be used to derive a point of departure in a nonlinear risk assessment for Ni 3 S 2 toxicity and carcinogenicity. - Highlights: • The mode of action for lung carcinogenicity of inhaled Ni 3 S 2 was investigated in rats. • Gene expression changes were determined in micro-dissected lung tissue at 1–4 weeks. • A non-genotoxic mode

  2. Effect of KOH concentration on LEO cycle life of IPV nickel-hydrogen flight cells. An update

    Science.gov (United States)

    Smithrick, John J.; Hall, Stephen W.

    1991-01-01

    An update of validation test results confirming the breakthrough in LEO cycle life of nickel-hydrogen cells containing 26 percent potassium hydroxide (KOH) electrolyte is presented. A breakthrough in the LEO cycle life of individual pressure vessel nickel-hydrogen cells is reported. The cycle life of boiler plate cells containing 26 percent KOH electrolyte was about 40,000 LEO cycles compared to 3500 cycles for cells containing 31 percent KOH.

  3. Effect of KOH concentration on LEO cycle life of IPV nickel-hydrogen flight cells - An update

    Science.gov (United States)

    Smithrick, John J.; Hall, Stephen W.

    1991-01-01

    An update of validation test results confirming the breakthrough in LEO cycle life of nickel-hydrogen cells containing 26 percent potassium hydroxide (KOH) electrolyte is presented. A breakthrough in the LEO cycle life of individual pressure vessel nickel-hydrogen cells is reported. The cycle life of boiler plate cells containing 26 percent KOH electrolyte was about 40,000 LEO cycles compared to 3500 cycles for cells containing 31 percent KOH.

  4. Compton profiles and Mulliken’s populations of cobalt, nickel and copper tungstates: Experiment and theory

    Energy Technology Data Exchange (ETDEWEB)

    Meena, B.S. [Department of Physics, M.L. Sukhadia University, Udaipur 313001, Rajasthan (India); Heda, N.L. [Department of Pure and Applied Physics, University of Kota, Kota 324010, Rajasthan (India); Kumar, Kishor; Bhatt, Samir; Mund, H.S. [Department of Physics, M.L. Sukhadia University, Udaipur 313001, Rajasthan (India); Ahuja, B.L., E-mail: blahuja@yahoo.com [Department of Physics, M.L. Sukhadia University, Udaipur 313001, Rajasthan (India)

    2016-03-01

    We present the first ever studies on Compton profiles of AWO{sub 4} (A=Co, Ni and Cu) using 661.65 keV γ-rays emitted by {sup 137}Cs source. The experimental momentum densities have been employed to validate exchange and correlation potentials within linear combination of atomic orbitals (LCAO) method. Density functional theory (DFT) with local density approximation and generalized gradient approximation and also the hybridization of Hartree-Fock and DFT (B3LYP and PBE0) have been considered under LCAO scheme. The LCAO-B3LYP scheme is found to be in better agreement with the experimental data than other approximations considered in this work, suggesting applicability of B3LYP approach in predicting the electronic properties of these tungstates. The Mulliken’s population (MP) data show charge transfer from Co/Ni/Cu and W to O atoms. The experimental profiles when normalized to same area show almost similar localization of 3d electrons (in real space) of Ni and Cu which is lower than that of Co in their AWO{sub 4} environment.

  5. Impedances of electrochemically impregnated nickel electrodes as functions of potential, KOH concentration, and impregnation method

    Science.gov (United States)

    Reid, Margaret A.

    1989-01-01

    Impedances of fifteen electrodes form each of the four U.S. manufactures were measured at 0.200 V vs. the Hg/HgO reference electrode. This corresponds to a voltage of 1.145 for a Ni/H2 cell. Measurements were also made of a representative sample of these at 0.44 V. At the higher voltage, the impedances were small and very similar, but at the lower voltage there were major differences between manufacturers. Electrodes from the same manufacturers showed only small differences. The impedances of electrodes from two manufacturers were considerably different in 26 percent KOH from those in 31 percent KOH. These preliminary results seen to correlate with the limited data from earlier life testing of cells from these manufacturers. The impedances of cells being tested for Space Station Freedom are being followed, and more impendance measurements of electrodes are being performed as functions of manufacturer, voltage, electrolyte concentration, and cycle history in hopes of finding better correlations of impedance with life.

  6. Variations in vanadium, nickel and lanthanoid element concentrations in urban air

    International Nuclear Information System (INIS)

    Moreno, Teresa; Querol, Xavier; Alastuey, Andres; Rosa, Jesus de la; Sanchez de la Campa, Ana Maria; Minguillon, MariCruz; Pandolfi, Marco; Gonzalez-Castanedo, Yolanda; Monfort, Eliseo; Gibbons, Wes

    2010-01-01

    The emission of trace metal pollutants by industry and transport takes place on a scale large enough to alter atmospheric chemistry and results in measurable differences between the urban background of inhalable particulate matter (PM) in different towns. This is particularly well demonstrated by the technogenic release into the atmosphere of V, Ni, and lanthanoid elements. We compare PM concentrations of these metals in large datasets from five industrial towns in Spain variously influenced by emissions from refinery, power station, shipping, stainless steel, ceramic tiles and brick-making. Increased La/Ce values in urban background inhalable PM, due to La-contamination from refineries and their residual products (fuel oils and petcoke), contrast with Ce-rich emissions from the ceramic related industry, and clearly demonstrate the value of this ratio as a sensitive and reliable tracer for many point source emissions. Similarly, anomalously high V/Ni values (> 4) can detect the influence of nearby high-V petcoke and fuel oil combustion, although the use of this ratio in urban background PM is limited by overlapping values in natural and anthropogenic materials. Geochemical characterisation of urban background PM is a valuable compliment to the physical monitoring of aerosols widely employed in urban areas, especially given the relevance of trace metal inhalation to urban health issues.

  7. Comparison of titanium cable tension band and nickel-titanium patella concentrator for patella fractures.

    Science.gov (United States)

    Zhao, Quan-Ming; Gu, Xiao-Feng; Cheng, Li; Feng, De-Hong

    2017-07-01

    Patellar fractures account for approximately 1% of all fractures. Due to the patella's importance as regards the extensor mechanism, effort should be made to preserve the patella. Several operative treatment methods have been introduced for patella fractures. This study aims to compare the clinical effect of a titanium cable tension band and nickeltitanium (NiTi) patella concentrator (NT-PC) in treating patella fractures. Thirty-nine patients with patella fractures were enrolled in this retrospective study. All the patients were treated via the open reduction internal fixation procedure using a titanium cable tension band or NT-PC. All the patients were followed up over an average period of 13 months. The main outcome measures were operation time, time of fracture union, postoperative complications, and Böstman knee scores. Statistical analyses were conducted between the 2 groups. All the patients were operated on successfully. The operation time of the NT-PC treatment group was less than that of the titanium cable tension band treatment group (p cable tension band and NT-PC groups, respectively. No significant difference was observed between the excellent and good results (p > 0.05). Both titanium cable tension band and NT-PC showed good efficacy for the treatment of patellar fractures. NT-PC fixation, a new option for the treatment of patella fractures, is a simple and effective fixation method.

  8. Nickel extraction from nickel matte

    Science.gov (United States)

    Subagja, R.

    2018-01-01

    In present work, the results of research activities to make nickel metal from nickel matte are presented. The research activities were covering a) nickel matte characterization using Inductively Couple plasma (ICP), Electron Probe Micro Analyzer (EPMA) and X-Ray Diffraction (XRD), b) nickel matte dissolution process to dissolve nickel from nickel matte into the spent electrolyte solutions that contains hydrochloric acid, c) purification of nickel chloride leach solution by copper cementation process to remove copper using nickel matte, selective precipitation process to remove iron, solvent extraction using Tri normal octyl amine to separate cobalt from nickel chloride solutions and d) Nickel electro winning process to precipitate nickel into the cathode surface from purified nickel chloride solution by using direct current. The research activities created 99, 72 % pure nickel metal as the final product of the process.

  9. Effect of surfactant concentration in the electrolyte on the tribological properties of nickel-tungsten carbide composite coatings produced by pulse electro co-deposition

    Energy Technology Data Exchange (ETDEWEB)

    Kartal, Muhammet, E-mail: kartal@sakarya.edu.tr [Sakarya University, Engineering Faculty, Metallurgical & Materials Engineering Department, Esentepe Campus, 54187 Sakarya (Turkey); Uysal, Mehmet [Sakarya University, Engineering Faculty, Metallurgical & Materials Engineering Department, Esentepe Campus, 54187 Sakarya (Turkey); Gul, Harun [Duzce University, Gumusova Vocational School, 81850 Duzce (Turkey); Alp, Ahmet; Akbulut, Hatem [Sakarya University, Engineering Faculty, Metallurgical & Materials Engineering Department, Esentepe Campus, 54187 Sakarya (Turkey)

    2015-11-01

    Highlights: • Effect of surfactant concentration on the co-deposited WC was investigated. • In the Ni matrix significantly high hardness was achieved by WC co-deposition. • Optimum surfactant resulted in obtaining superior wear resistance in the Ni. • Friction coefficient was decreased by WC co-deposition in the Ni matrix. - Abstract: A nickel plating bath containing WC particles was used to obtain hard and wear-resistant particle reinforced Ni/WC MMCs on steel surfaces for anti-wear applications. Copper substrates were used for electro co-deposition of Ni matrix/WC with the particle size of <1 μm tungsten carbide reinforcements. The influence of surfactant (sodium dodecyl sulfate, SDS) concentration on particle distribution, microhardness and wear resistance of composite coatings has been studied. The nickel films were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The effects of the surfactant on the zeta potential, co-deposition and distribution of WC particles in the nickel matrix, as well as the tribological properties of composite coatings were also investigated. The tribological behaviors of the electrodeposited WC composite coatings sliding against M50 steel ball (Ø 10 mm) were examined on a CSM Instrument. All friction and wear tests were performed without lubrication at room temperature and in the ambient air (relative humidity 55–65%).

  10. Characterization and assessment of dermal and inhalable nickel exposures in nickel production and primary user industries.

    Science.gov (United States)

    Hughson, G W; Galea, K S; Heim, K E

    2010-01-01

    The aim of this study was to measure the levels of nickel in the skin contaminant layer of workers involved in specific processes and tasks within the primary nickel production and primary nickel user industries. Dermal exposure samples were collected using moist wipes to recover surface contamination from defined areas of skin. These were analysed for soluble and insoluble nickel species. Personal samples of inhalable dust were also collected to determine the corresponding inhalable nickel exposures. The air samples were analysed for total inhalable dust and then for soluble, sulfidic, metallic, and oxidic nickel species. The workplace surveys were carried out in five different workplaces, including three nickel refineries, a stainless steel plant, and a powder metallurgy plant, all of which were located in Europe. Nickel refinery workers involved with electrolytic nickel recovery processes had soluble dermal nickel exposure of 0.34 microg cm(-2) [geometric mean (GM)] to the hands and forearms. The GM of soluble dermal nickel exposure for workers involved in packing nickel salts (nickel chloride hexahydrate, nickel sulphate hexahydrate, and nickel hydroxycarbonate) was 0.61 microg cm(-2). Refinery workers involved in packing nickel metal powders and end-user powder operatives in magnet production had the highest dermal exposure (GM = 2.59 microg cm(-2) soluble nickel). The hands, forearms, face, and neck of these workers all received greater dermal nickel exposure compared with the other jobs included in this study. The soluble nickel dermal exposures for stainless steel production workers were at or slightly above the limit of detection (0.02 microg cm(-2) soluble nickel). The highest inhalable nickel concentrations were observed for the workers involved in nickel powder packing (GM = 0.77 mg m(-3)), although the soluble component comprised only 2% of the total nickel content. The highest airborne soluble nickel exposures were associated with refineries using

  11. The deconvolution of sputter-etching surface concentration measurements to determine impurity depth profiles

    International Nuclear Information System (INIS)

    Carter, G.; Katardjiev, I.V.; Nobes, M.J.

    1989-01-01

    The quasi-linear partial differential continuity equations that describe the evolution of the depth profiles and surface concentrations of marker atoms in kinematically equivalent systems undergoing sputtering, ion collection and atomic mixing are solved using the method of characteristics. It is shown how atomic mixing probabilities can be deduced from measurements of ion collection depth profiles with increasing ion fluence, and how this information can be used to predict surface concentration evolution. Even with this information, however, it is shown that it is not possible to deconvolute directly the surface concentration measurements to provide initial depth profiles, except when only ion collection and sputtering from the surface layer alone occur. It is demonstrated further that optimal recovery of initial concentration depth profiles could be ensured if the concentration-measuring analytical probe preferentially sampled depths near and at the maximum depth of bombardment-induced perturbations. (author)

  12. Temporal Profiles Dissociate Regional Extracellular Ethanol versus Dopamine Concentrations

    Science.gov (United States)

    2015-01-01

    In vivo monitoring of dopamine via microdialysis has demonstrated that acute, systemic ethanol increases extracellular dopamine in regions innervated by dopaminergic neurons originating in the ventral tegmental area and substantia nigra. Simultaneous measurement of dialysate dopamine and ethanol allows comparison of the time courses of their extracellular concentrations. Early studies demonstrated dissociations between the time courses of brain ethanol concentrations and dopaminergic responses in the nucleus accumbens (NAc) elicited by acute ethanol administration. Both brain ethanol and extracellular dopamine levels peak during the first 5 min following systemic ethanol administration, but the dopamine response returns to baseline while brain ethanol concentrations remain elevated. Post hoc analyses examined ratios of the dopamine response (represented as a percent above baseline) to tissue concentrations of ethanol at different time points within the first 25–30 min in the prefrontal cortex, NAc core and shell, and dorsomedial striatum following a single intravenous infusion of ethanol (1 g/kg). The temporal patterns of these “response ratios” differed across brain regions, possibly due to regional differences in the mechanisms underlying the decline of the dopamine signal associated with acute intravenous ethanol administration and/or to the differential effects of acute ethanol on the properties of subpopulations of midbrain dopamine neurons. This Review draws on neurochemical, physiological, and molecular studies to summarize the effects of acute ethanol administration on dopamine activity in the prefrontal cortex and striatal regions, to explore the potential reasons for the regional differences observed in the decline of ethanol-induced dopamine signals, and to suggest directions for future research. PMID:25537116

  13. Effect of surfactant concentration in the electrolyte on the tribological properties of nickel-tungsten carbide composite coatings produced by pulse electro co-deposition

    Science.gov (United States)

    Kartal, Muhammet; Uysal, Mehmet; Gul, Harun; Alp, Ahmet; Akbulut, Hatem

    2015-11-01

    A nickel plating bath containing WC particles was used to obtain hard and wear-resistant particle reinforced Ni/WC MMCs on steel surfaces for anti-wear applications. Copper substrates were used for electro co-deposition of Ni matrix/WC with the particle size of <1 μm tungsten carbide reinforcements. The influence of surfactant (sodium dodecyl sulfate, SDS) concentration on particle distribution, microhardness and wear resistance of composite coatings has been studied. The nickel films were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The effects of the surfactant on the zeta potential, co-deposition and distribution of WC particles in the nickel matrix, as well as the tribological properties of composite coatings were also investigated. The tribological behaviors of the electrodeposited WC composite coatings sliding against M50 steel ball (Ø 10 mm) were examined on a CSM Instrument. All friction and wear tests were performed without lubrication at room temperature and in the ambient air (relative humidity 55-65%).

  14. Effect of KOH concentration on LEO cycle life of IPV nickel-hydrogen flight cell - Update II

    Science.gov (United States)

    Smithrick, John J.; Hall, Stephen W.

    1992-01-01

    An update of validation test results confirming the breakthrough in LEO cycle life of nickel-hydrogen cells containing 26 percent KOH electrolyte is presented. A breakthrough in the LEO cycle life of individual pressure vessel (IPV) nickel-hydrogen cells has been previously reported. The cycle life of boiler plate cells containing 26 percent potassium hydroxide (KOH) electrolyte was about 40,000 LEO cycles, compared to 3500 cycles for cells containing 31 percent KOH. The cycle regime was a stressful accelerated LEO, which consisted of a 27.5 min charge followed by a 17.5 min discharge (2X normal rate). The depth-of-discharge was 80 percent. Six 48-Ah Hughes recirculation design IPV nickel-hydrogen flight battery cells are being evaluated. Three of the cells contain 26 percent KOH (test cells), and three contain 31 percent KOH (control cells). They are undergoing real time LEO cycle life testing. The cycle regime is a 90-min LEO orbit consisting of a 54-min charge followed by a 36-min discharge. The depth-of-discharge is 80 percent. The cell temperature is maintained at 10 C. The three 31 percent KOH cells failed (cycles 3729, 4165, and 11355). One of the 26 percent KOH cells failed at cycle 15314. The other two 26 percent KOH cells were cycled for over 16,000 cycles during the continuing test.

  15. Study on characteristics of fluorine concentration profiles in fluorosis sheep teeth and bones

    International Nuclear Information System (INIS)

    Song Shizhan; Shui Yongqing; Wang Lianbin; Yang Huazhong; Zhai Xujiu; Wang Yuwen; Lei Guilin

    1990-01-01

    The deep-ward fluorine concentration profiles in fluorosis sheep teeth and bones were determined through 19 F(p, αγ) 16 O reaction with proton energy 3.2 MeV. The profiles show a diffusion characteristic, indicating that the fluorine ion diffusion may be one of the important factors that brought forth pathological changes of livestock teeth and bones

  16. Excessive nickel release from mobile phones--a persistent cause of nickel allergy and dermatitis

    DEFF Research Database (Denmark)

    Jensen, Peter; Johansen, Jeanne D; Zachariae, Claus

    2011-01-01

    Despite the political intention to limit nickel allergy and dermatitis in Europeans, nickel allergy remains frequent. There are several explanations for the persistence of nickel allergy and dermatitis, including the increasing use of mobile phones. Before regulation of nickel release from mobile...... phones, we showed that eight (19.5%) of 41 mobile phones marketed in Denmark between 2003 and 2007 released nickel in concentrations that may result in nickel allergy and dermatitis. In 2009, the EU Nickel Directive was revised to include nickel-releasing mobile phones....

  17. Excessive nickel release from mobile phones--a persistent cause of nickel allergy and dermatitis

    DEFF Research Database (Denmark)

    Jensen, Peter; Johansen, Jeanne D; Zachariae, Claus

    2011-01-01

    phones, we showed that eight (19.5%) of 41 mobile phones marketed in Denmark between 2003 and 2007 released nickel in concentrations that may result in nickel allergy and dermatitis. In 2009, the EU Nickel Directive was revised to include nickel-releasing mobile phones.......Despite the political intention to limit nickel allergy and dermatitis in Europeans, nickel allergy remains frequent. There are several explanations for the persistence of nickel allergy and dermatitis, including the increasing use of mobile phones. Before regulation of nickel release from mobile...

  18. Nickel accumulation by Hybanthus floribundus

    Energy Technology Data Exchange (ETDEWEB)

    Severne, B C

    1974-04-26

    Several ecotypes of Hybanthus floribundus are found across the southern part of Australia. However, the three nickel accumulating ecotypes are restricted to a broad belt in Western Australia. Nickel concentrations in this shrub were observed to decrease southwards (from 8000 to 1000 p.p.m.) as the annual rainfall increased from 7 inches to more than 30 inches. Studies have shown that nickel concentrations increase from the roots through the rootstock, into the stems and reach maximum towards the leaf tips. High nickel concentrations are also seen in seed capsules (1500 p.p.m.), seeds (2000 p.p.m.) and flowers. The maximum nickel concentration recorded is 1.6% (26% nickel in ash) in mature leaf tissue. 16 references, 2 tables.

  19. Assessing one-dimensional diffusion in nanoporous materials from transient concentration profiles

    International Nuclear Information System (INIS)

    Heinke, Lars; Kaerger, Joerg

    2008-01-01

    The use of interference microscopy has enabled the direct observation of transient concentration profiles generated by intracrystalline transport diffusion in nanoporous materials. The thus accessible intracrystalline concentration profiles contain a wealth of information which cannot be deduced by any macroscopic method. In this paper, we illustrate five different ways for determining the concentration-dependent diffusivity in one-dimensional systems and two for the surface permeability. These methods are discussed by application to concentration profiles evolving during the uptake of methanol by the zeolite ferrierite and of methanol by the metal organic framework (MOF) manganese(II) formate. We show that the diffusivity can be calculated most precisely by means of Fick's 1st law. As the circumstances permit, Boltzmann's integration method also yields very precise results. Furthermore, we present a simple procedure that enables the estimation of the influence of the surface barrier on the overall uptake process by plotting the boundary concentration versus the overall uptake

  20. NICKEL – ENVIRONMENTAL ALLERGEN

    Directory of Open Access Journals (Sweden)

    Henryka Langauer-Lewowicka

    2010-06-01

    Full Text Available Nickel (Ni is ubiquitus in our biosphere because of its emission from natural and anthropogenic sources. Its toxic and carcinogenic properties are well recognised only in workers exposed to high Ni concentrations. Nickel allergy is the most common form of cutaneus hypersensitivity in general population and also in occupationally exposed groups. As sensitizing agent Ni has a high prevalence of allergic contact dermatitis. The most important known risk factor associated with nickel allergy is ear piercing and use of other jewelry in females. In general population 17 % adults and 8 % children have Ni allergy symptoms. Permanently growing Ni allergy is regarded as serious risk for public health.

  1. Construction of a predictive model for concentration of nickel and vanadium in vacuum residues of crude oils using artificial neural networks and LIBS.

    Science.gov (United States)

    Tarazona, José L; Guerrero, Jáder; Cabanzo, Rafael; Mejía-Ospino, E

    2012-03-01

    A predictive model to determine the concentration of nickel and vanadium in vacuum residues of Colombian crude oils using laser-induced breakdown spectroscopy (LIBS) and artificial neural networks (ANNs) with nodes distributed in multiple layers (multilayer perceptron) is presented. ANN inputs are intensity values in the vicinity of the emission lines 300.248, 301.200 and 305.081 nm of the Ni(I), and 309.310, 310.229, and 311.070 nm of the V(II). The effects of varying number of nodes and the initial weights and biases in the ANNs were systematically explored. Average relative error of calibration/prediction (REC/REP) and average relative standard deviation (RSD) metrics were used to evaluate the performance of the ANN in the prediction of concentrations of two elements studied here. © 2012 Optical Society of America

  2. Tissue concentration-time profile of selenium after sodium selenite administration to rats

    Energy Technology Data Exchange (ETDEWEB)

    Kaneko, Megumi; Natsuhori, Masahiro; Ito, Nobuhiko [Department of Veterinary Radiology and Radiation Biology, Kitasato University School of Veterinary Medicine, Towada, Aomori (Japan); Sera, Koichiro [Cyclotron Research Center, Iwate Medical University, Takizuka, Iwate (Japan); Futatsugawa, Shoji [Nishina Memorial Cyclotron Center (NMCC), Takizuka, Iwate (Japan)

    1999-07-01

    Selenium (Se) concentration-time profiles in plasma and organs including liver, kidney, heart, lung, spleen and brain of rats (Jcl Wister, 9 wks old, n=32) were investigated after a single intravenous (iv) / oral (po) administration of sodium selenite (dose is equivalent to 2 mg/kg b.w. of Se). The Se concentration was determined by PIXE analysis. Among the investigated biological samples, Se concentration was the highest in the kidney or liver, followed by the heart, lung or spleen, then plasma, and the brain. Se concentrations in these organs were 0.5 to 5 times of plasma Se. The distribution profiles of Se in the organs were dependent on the route of administration. Furthermore, their profiles appeared almost parallel to the plasma Se-concentration in a logarithmic scale. Compared to the Se concentration-time profiles in plasma and organs by the route of administration, po group showed about 1/4-1/2 of the Se concentration in iv group except for kidney. Kidney kept relatively higher concentration of Se, which was similar in the both groups. This may explain our recently published data that urinary excretion was similar in the both groups. The relative oral bioavailability of plasma and each organ was calculated by the ratio of area under the concentration-time curve after oral administration (AUCpo) to AUCiv. Each organ appeared to have their own bioavailability (i.e., liver 39%, kidney 97%, heart 37%, lung 18%, spleen 10%, and brain 72%), where plasma was 46%. These results highly suggested that different Se distribution in organs by the different route of administration was due to the different metabolic profile. (author)

  3. Tissue concentration-time profile of selenium after sodium selenite administration to rats

    International Nuclear Information System (INIS)

    Kaneko, Megumi; Natsuhori, Masahiro; Ito, Nobuhiko; Sera, Koichiro; Futatsugawa, Shoji

    1999-01-01

    Selenium (Se) concentration-time profiles in plasma and organs including liver, kidney, heart, lung, spleen and brain of rats (Jcl Wister, 9 wks old, n=32) were investigated after a single intravenous (iv) / oral (po) administration of sodium selenite (dose is equivalent to 2 mg/kg b.w. of Se). The Se concentration was determined by PIXE analysis. Among the investigated biological samples, Se concentration was the highest in the kidney or liver, followed by the heart, lung or spleen, then plasma, and the brain. Se concentrations in these organs were 0.5 to 5 times of plasma Se. The distribution profiles of Se in the organs were dependent on the route of administration. Furthermore, their profiles appeared almost parallel to the plasma Se-concentration in a logarithmic scale. Compared to the Se concentration-time profiles in plasma and organs by the route of administration, po group showed about 1/4-1/2 of the Se concentration in iv group except for kidney. Kidney kept relatively higher concentration of Se, which was similar in the both groups. This may explain our recently published data that urinary excretion was similar in the both groups. The relative oral bioavailability of plasma and each organ was calculated by the ratio of area under the concentration-time curve after oral administration (AUCpo) to AUCiv. Each organ appeared to have their own bioavailability (i.e., liver 39%, kidney 97%, heart 37%, lung 18%, spleen 10%, and brain 72%), where plasma was 46%. These results highly suggested that different Se distribution in organs by the different route of administration was due to the different metabolic profile. (author)

  4. 1 Molar concentration hydrofluoric acid effect at 400 C in the corrosion resistance of alloys containing nickel

    International Nuclear Information System (INIS)

    Contreras P, H.

    1992-01-01

    Corrosion rate for pure nickel, Inconel 600 and Monel alloys in a 1 Molar hydrofluoric acid solution at a 40 0 C temperature were determined. For contrasting purposes both SAE 304 SS and SAE 316 SS were included. As expected these Stainless Steels do not show good corrosion performance in the solution used. Several expressions correlating the weight and thickness loss v/s time were obtained. In the particular case of Monel, up to 2.021 hours, two expressions for the weight loss and three expressions for the thickness loss were obtained with a close to 1,0 correlation coefficient value. The Monel showed the best overall corrosion performance among the tested alloys. (author)

  5. High energy muon induced radioactive nuclides in nickel plate and its use for 2-D muon-beam image profile

    International Nuclear Information System (INIS)

    Kurebayashi, Y.; Sakurai, H.; Takahashi, Y.; Doshita, N.; Kikuchi, S.; Tokanai, F.; Horiuchi, K.; Tajima, Y.; Oe, T.; Sato, T.; Gunji, S.; Inui, E.; Kondo, K.; Iwata, N.; Sasaki, N.; Matsuzaki, H.; Kunieda, S.

    2015-01-01

    Target materials were exposed to a muon beam with an energy of 160 GeV/c at the COMPASS experiment line in CERN-SPS to measure the production cross-sections for muon-induced radionuclides. A muon imager containing four nickel plates, each measuring 100 mm×100 mm, exposed to the IP plate successfully detected the muon beam image during an irradiation period of 33 days. The contrasting density rate of the nickel plate was (5.2±0.7)×10 –9 PSL/muon per one-day exposure to IP. The image measured 122 mm and 174 mm in horizontal and vertical lengths, respectively, in relation to the surface of the base, indicating that 50±6% of the muon beam flux is confined to an area of 18% of the whole muon beam. The number of muons estimated from the PSL value in the total beam image area (0.81±0.1)×10 13 was comparable to the total muon counts of the ion-chamber at the M2 beam line in the CERN-SPS. The production cross-sections of Cr-51, Mn-54, Co-56, Co-57, and Co-58 in nickel were 0.19±0.08, 0.34±0.06, 0.5±0.05, 3.44±0.07, 0.4±0.03 in the unit of mb, respectively, reducing muon associated particles effects. They are approximately 10 times smaller than that a proceeding study by Heisinger et al

  6. Nickel in nails, hair and plasma from nickel-hypersensitive women

    DEFF Research Database (Denmark)

    Gammelgaard, Bente; Veien, Niels

    1990-01-01

    The concentrations of nickel in finger-nails, toe-nails, hair and plasma from 71 nickel-hypersensitive women and 20 non-hypersensitive women were determined. Nickel concentrations in finger-nails were significantly higher than in toe-nails in both the nickel-hypersensitive group and the control...... group. Nickel-sensitive women had significantly higher levels of nickel in toe-nails, hair and plasma than had control subjects, whereas there was no significant difference in nickel concentration in finger-nails between the two groups. No correlation could be demonstrated between nickel levels in any...... combination of nails, hair and plasma in the nickel-hypersensitive or in the control group....

  7. Measurement of central nickel density in Doublet III plasmas with a soft x-ray diode array

    International Nuclear Information System (INIS)

    Groebner, R.J.; Jahns, G.L.; Ejima, S.; Hsieh, C.L.

    1985-01-01

    An array of soft x-ray diodes has been used to obtain central nickel densities for discharges in the Doublet III tokamak, during operation with an inconel primary limiter, in which nickel L-line radiation dominated the diode signals. The nature of the diode signals is determined primarily by comparison with soft x-ray spectra. The contribution of the continuum portion of the spectra to the central diode signal can be calculated and compared to the observed signal. When the diode signal is dominated by nickel L-line emission, the observed signal is considerably larger than the calculated continuum contribution. Chordal data from the array of diodes are inverted to provide the spatial profile of soft x-ray emission. Because the diodes are absolute detectors of radiation, the soft x-ray emission profile is used to obtain the absolute nickel concentration and density profile in the center of the plasma. A computer code, including over 100 nickel L-line transitions, has been developed to obtain the nickel density. The nickel L-line cooling rate, calculated with the code, is presented. The nickel density obtained by this technique agrees well with that obtained from the K/sub α/ line intensity measured with a soft x-ray spectrometer and that obtained from a bolometric measurement of central radiated power coupled with a coronal equilibrium model of the radiation

  8. 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

  9. Determining concentration depth profiles in fluorinated networks by means of electric force microscopy

    International Nuclear Information System (INIS)

    Miccio, Luis A.; Kummali, Mohammed M.; Alegria, Angel; Montemartini, Pablo E.; Oyanguren, Patricia A.; Schwartz, Gustavo A.; Colmenero, Juan

    2011-01-01

    By means of electric force microscopy, composition depth profiles were measured with nanometric resolution for a series of fluorinated networks. By mapping the dielectric permittivity along a line going from the surface to the bulk, we were able to experimentally access to the fluorine concentration profile. Obtained data show composition gradient lengths ranging from 30 nm to 80 nm in the near surface area for samples containing from 0.5 to 5 wt. % F, respectively. In contrast, no gradients of concentration were detected in bulk. This method has several advantages over other techniques because it allows profiling directly on a sectional cut of the sample. By combining the obtained results with x-ray photoelectron spectroscopy measurements, we were also able to quantify F/C ratio as a function of depth with nanoscale resolution.

  10. Nickel hydroxide modified electrodes for urea determination

    Directory of Open Access Journals (Sweden)

    Luiz Henrique Dall´Antonia

    2007-03-01

    Full Text Available Nickel hydroxide films were prepared by electrodeposition from a solution Ni(NO32 0,05 mol L ?¹ on ITO electrodes (Tin oxide doped with Indium on PET-like plastic film, applying a current of - 0,1 A cm ?² during different time intervals between 1800 and 7200 s. The electrochemical behavior of the nickel hydroxide electrode was investigated through a cyclic voltammogram, in NaOH 1,0 mol L ?¹, where it was observed two peaks in the profile in 0,410 and 0,280 V, corresponding to redox couple Ni(II/Ni(III. A sensor for urea presenting a satisfactory answer can be obtained when, after the deposit of the film of Ni(OH2 on the electrode of nickel, it is immersed in a solution of NaOH 1,0 mol L ?¹ and applying a potential of + 0,435 V, where the maximum of the anodic current occurs in the cyclic voltammogram. Analyzing the results it can be observed that, for a range of analite concentration between 5 to 50 m mol L ?¹, the behavior is linear and the sensibility found was of 20,3 mA cm?² (mol L?¹?¹, presenting reproducibility confirming the nickel hydroxide electrodes utilization for the determination of urea.

  11. The influence of nickel sulphate on some physiological aspects of two cultivars of Raphanus sativus L.

    Directory of Open Access Journals (Sweden)

    Latif Helmy H.

    2010-01-01

    Full Text Available In this study two cultivars of radish Raphanus sativus cv. longipinnatus (white radish and Raphanus sativus cv. Cherry Belle (red radish were treated with different concentrations of nickel sulphate (0.0-50-100-150-200 ppm. The fresh and dry weight of shoots and roots, photosynthetic pigments, some antioxidant enzymes, total carbohydrates, total proteins and the SDS-PAGE protein profile of both cultivars were determined after 32 days. The results showed that increasing nickel sulphate concentrations decreased the fresh and dry weights of the shoots and roots, photosynthetic pigments, total carbohydrates and total protein in both cultivars. Higher concentrations of nickel sulphate increased the activity of catalase, peroxidase and polypenol oxidase. Electrophoresis banding profiles of proteins revealed qualitative and quantitative changes, and also the appearance or disappearance of some bands of the two cultivars. .

  12. Relationship between nickel allergy and diet

    Directory of Open Access Journals (Sweden)

    Sharma Ashimav

    2007-01-01

    Full Text Available Nickel is a ubiquitous trace element and it occurs in soil, water, air and of the biosphere. It is mostly used to manufacture stainless steel. Nickel is the commonest cause of metal allergy. Nickel allergy is a chronic and recurring skin problem; females are affected more commonly than males. Nickel allergy may develop at any age. Once developed, it tends to persist life-long. Nickel is present in most of the dietary items and food is considered to be a major source of nickel exposure for the general population. Nickel content in food may vary considerably from place to place due to the difference in nickel content of the soil. However, certain foods are routinely high in nickel content. Nickel in the diet of a nickel-sensitive person can provoke dermatitis. Careful selection of food with relatively low nickel concentration can bring a reduction in the total dietary intake of nickel per day. This can influence the outcome of the disease and can benefit the nickel sensitive patient.

  13. Methanol degradation in granular sludge reactors at sub-optimal metal concentrations: role of iron, nickel and cobalt

    NARCIS (Netherlands)

    Zandvoort, M.H.; Geerts, R.; Lettinga, G.; Lens, P.N.L.

    2003-01-01

    The effect of sub-optimal trace metal concentrations on the conversion of methanol in an upflow anaerobic sludge bed (UASB) reactor was investigated by studying the effect of decreased influent trace metal concentrations on the reactor efficiency, methanol conversion route and sludge

  14. Bradsim-prediction of solute concentration. Temperature and physical property profiles along pulsed plate columns

    International Nuclear Information System (INIS)

    Logsdail, D.H.; Evans, S.F.; Jenkins, J.A.; Smith, I.J.

    1988-01-01

    Dynamic model of the operation of the BRADSIM pulsed plate column is developed. Examples of simulation of the pures process extraction system are given. Profiles of dissolved substances concentrations and profiles of physical properties of liquid along the column are provided. Calculated values are compared with the experimental data, obtained in case of the column 50 mm in diameter, Harwell extractional facility and Sellafield pulsed column 300 mm in diameter for extraction systems uranyl nitrate-nitric acid-20% and 30% TBP in kerosene. 2 refs.; 6 figs

  15. Characterizing contaminant concentrations with depth by using the USGS well profiler in Oklahoma, 2003-9

    Science.gov (United States)

    Smith, S. Jerrod; Becker, Carol J.

    2011-01-01

    Since 2003, the U.S. Geological Survey (USGS) Oklahoma Water Science Center has been using the USGS well profiler to characterize changes in water contribution and contaminant concentrations with depth in pumping public-supply wells in selected aquifers. The tools and methods associated with the well profiler, which were first developed by the USGS California Water Science Center, have been used to investigate common problems such as saline water intrusion in high-yield irrigation wells and metals contamination in high-yield public-supply wells.

  16. Effect on growth and nickel content of cabbage plants watered with nickel solutions

    Energy Technology Data Exchange (ETDEWEB)

    Christensen, O B

    1979-01-01

    Chinese cabbage plants were watered with different concentrations of NiCl/sub 2/ solutions and the effect on growth and uptake of nickel in the plants were studied. No toxic effect on plant growth was observed. A higher content of nickel was found in the plants exposed to more concentrated nickel solutions. Nickel contamination and its clinical consequences are discussed. 29 references, 1 figure, 1 table.

  17. Vertical profiles of black carbon concentration and particle number size distribution in the North China Plain

    Science.gov (United States)

    Ran, L.; Deng, Z.

    2013-12-01

    The vertical distribution of aerosols is of great importance to our understanding in the impacts of aerosols on radiation balance and climate, as well as air quality and public health. To better understand and estimate the effects of atmospheric components including trace gases and aerosols on atmospheric environment and climate, an intensive field campaign, Vertical Observations of trace Gases and Aerosols in the North China Plain (VOGA-NCP), was carried out from late July to early August 2013 over a rural site in the polluted NCP. During the campaign, vertical profiles of black carbon (BC) concentration and particle number size distribution were measured respectively by a micro-Aethalometer and an optical particle counter attached to a tethered balloon within 1000 m height. Meteorological parameters, including temperature, relative humidity, wind speed and wind direction, were measured simultaneously by a radiosonde also attached to the tethered balloon. Preliminary results showed distinct diurnal variations of the vertical distribution of aerosol total number concentration and BC concentration, following the development of the mixing layer. Generally, there was a well mixing of aerosols within the mixing layer and a sharp decrease above the mixing layer. Particularly, a small peak of BC concentrations was observed around 400-500 m height for several profiles. Further analysis would be needed to explain such phenomenon. It was also found that measured vertical profiles of BC using the filter-based method might be affected by the vertical distribution of relative humidity.

  18. Concentration-dependent induction of reactive oxygen species, cell cycle arrest and apoptosis in human liver cells after nickel nanoparticles exposure.

    Science.gov (United States)

    Ahmad, Javed; Alhadlaq, Hisham A; Siddiqui, Maqsood A; Saquib, Quaiser; Al-Khedhairy, Abdulaziz A; Musarrat, Javed; Ahamed, Maqusood

    2015-02-01

    Due to advent of nanotechnology, nickel nanoparticles (Ni NPs) are increasingly recognized for their utility in various applications including catalysts, sensors and electronics. However, the environmental and human health effects of Ni NPs have not been fully investigated. In this study, we examined toxic effects of Ni NPs in human liver (HepG2) cells. Ni NPs were prepared and characterized by X-ray diffraction, transmission electron microscopy and dynamic light scattering. We observed that Ni NPs (size, ∼28 nm; concentration range, 25-100 μg/mL) induced cytotoxicity in HepG2 cells and degree of induction was concentration-dependent. Ni NPs were also found to induce oxidative stress in dose-dependent manner evident by induction of reactive oxygen species and depletion of glutathione. Cell cycle analysis of cells treated with Ni NPs exhibited significant increase of apoptotic cell population in subG1 phase. Ni NPs also induced caspase-3 enzyme activity and apoptotic DNA fragmentation. Upregulation of cell cycle checkpoint gene p53 and bax/bcl-2 ratio with a concomitant loss in mitochondrial membrane potential suggested that Ni NPs induced apoptosis in HepG2 cells was mediated through mitochondrial pathway. This study warrants that applications of Ni NPs should be carefully assessed as to their toxicity to human health. © 2013 Wiley Periodicals, Inc.

  19. Effect of nickel doping concentration on structural and magnetic properties of ultrafine diluted magnetic semiconductor ZnO nanoparticles

    International Nuclear Information System (INIS)

    Sharma, Prashant K.; Dutta, Ranu K.; Pandey, Avinash C.

    2009-01-01

    The ZnO:Ni 2+ nanoparticles of mean size 2-12 nm were synthesized at room temperature by the simple co-precipitation method. The crystallite structure, morphology and size were determined by X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM). The wurtzite structure of ZnO gradually degrades with the increasing Ni doping concentration and an additional NiO-associated diffraction peak was observed above 15% of Ni 2+ doping. The change in magnetic behavior of the nanoparticles of ZnO with varying Ni 2+ doping concentration was investigated using a vibrating sample magnetometer (VSM). Initially, these nanoparticles showed strong ferromagnetic behavior, however, at higher doping percentage of Ni 2+ , the ferromagnetic behavior was suppressed and paramagnetic nature was observed. The enhanced antiferromagnetic interaction between neighboring Ni-Ni ions suppressed the ferromagnetism at higher doping concentrations of Ni 2+ .

  20. Measure of hydrogen concentration profile in materials by resonant nuclear reactions

    International Nuclear Information System (INIS)

    Livi, R.P.; Zawislak, F.C.; Acquadro, J.C.

    1986-01-01

    The technique for determining the profile of hydrogen concentration in proximities of the surface of materials, is presented. The preliminary measurements were done, using the Pelletron accelerator at Sao Paulo University (USP), in Brazil, for the resonant-nuclear reaction 1 H( 19 F, α γ) 16 O. By using this reaction the technique is sensitive for concentrations above 500 ppm, which could be reduced to 100 ppm through special shieldings and other techniques to reduce the background radiation. (M.C.K.) [pt

  1. The radon concentration profile and the flux from a pilot-scale layered tailings pile

    International Nuclear Information System (INIS)

    Zettwoog, P.; Fourcade, N.; Campbell, F.E.; Caplan, H.

    1982-01-01

    A pilot tailings model was constructed to demonstrate the feasibility of the sub-aerial technique of tailing deposition for the proposed uranium mine and mill at Key Lake, Saskatchewan. A series of radon measurements were made on the model and results obtained for the radon concentration profile in the tailings, and for the flux from the surface. The results were compared with the model calculations of Zettwoog. (U.K.)

  2. Profiles determination of Cesium-137 concentration in the main areas of Goiania radiological accident

    International Nuclear Information System (INIS)

    Rocca, H.C.C.; Aoki, P.E.; Enokihara, C.T.; Rostelato, M.; Lepki, V.; Bambalas, E.

    1988-07-01

    This paper describes the profiles determination of cesium-137 concentration measured in function of depth and applied in seven areas considered as the main contamination focus. Since november 14th to december 17th 1987, 125 soil drillings were made and a total of 740 soil samples were prepared. Obtained data allowed to calculate the soil volume to be removed from contaminate areas. It was verified that after remotions the remaining activity was approximately 0,89Ci. (author) [pt

  3. Concentrations and congener profiles of chlorinated paraffins in domestic polymeric products in China.

    Science.gov (United States)

    Wang, Chu; Gao, Wei; Liang, Yong; Wang, Yawei; Jiang, Guibin

    2018-03-21

    Chlorinated paraffins (CPs) are widely used in domestic polymeric products as plasticizers and fire retardants. In this study, concentrations and congener profiles of short-chain and medium-chain chlorinated paraffins (SCCPs and MCCPs) were investigated in domestic polymeric products, including plastics, rubber and food packaging in China. The average concentrations of SCCPs in polyethylene terephthalate (PET), polypropylene (PP), polyethylene (PE) and food packaging were 234, 3968, 150 and 188 ng/g, respectively and the corresponding average concentrations of MCCPs in these samples were 37.4, 2537, 208 and 644 ng/g, respectively. The concentrations of CPs in rubber and polyvinylchloride (PVC) were significantly higher than in other matrices. The highest concentrations of SCCPs and MCCPs were found in a PVC cable sheath with 191 mg/g and 145 mg/g, respectively. Congener group profiles analysis indicated C 11 - and C 13 -congener groups were predominant in carbon homologues of SCCPs, and C 14 -congener groups were predominant in MCCPs. High levels of SCCPs and MCCPs in domestic polymeric products implied that they might be a significant source to the environment and human exposure. Copyright © 2018. Published by Elsevier Ltd.

  4. Bulk diffusion and solubility of silver and nickel in lead, lead-silver and lead-nickel solid solutions

    International Nuclear Information System (INIS)

    Amenzou-Badrour, H.; Moya, G.; Bernardini, J.

    1988-01-01

    The results of a study of solubility and bulk diffusion of /sup 110/Ag and /sup 63/Ni in lead, lead-silver and lead-nickel solid solutions in the temperature range 220 to 88 0 C are reported. Owing to the low solubility of silver and nickel in lead, Fick's solution corresponding to the boundary condition of a constant concentration of solute at the surface has been used. Depth profile concentration analysis suggests a fundamental difference between the diffusion mechanisms of silver and nickel. Since silver penetration profiles in pure lead give diffusion coefficients independent of the penetration depth and silver concentration, it is suggested that slight decreases of silver diffusivity in lead-silver solid solutions have no significance. This implies that the interstitial silver atoms do not associate significantly with each other to form Ag-Ag dimers. In contrast, different behaviors of /sup 63/Ni depth profile concentration in pure lead and saturated PbNi solid solutions agree with a Ni-Ni interaction leading to the formation of less mobile dimers near the surface in pure lead

  5. Determination of selenium in samples of concentrated of nickel plus cobalt using the analysis through activation with epi thermic neutron

    International Nuclear Information System (INIS)

    Capote Rodriguez, G.; Perez Zayas, G.; Hernandez Rivero, A.; Moreno Bermudez, G.; Ribeiro Guevara, S.; Arribere, M.A.; Molina Insfran, J.

    1997-01-01

    In this work, the concentration of selenium and other elements was determined. Seventeen samples of sulfides plus cobalt were used. Among the employed methods for such purpose, the analysis was made through neutronic activation, in its instrumental variants, and by means of the application of radiochemical separation. (author) [es

  6. Mechanisms of nickel toxicity in microorganisms

    Science.gov (United States)

    Macomber, Lee

    2014-01-01

    Summary Nickel has long been known to be an important human toxicant, including having the ability to form carcinomas, but until recently nickel was believed to be an issue only to microorganisms living in nickel-rich serpentine soils or areas contaminated by industrial pollution. This assumption was overturned by the discovery of a nickel defense system (RcnR/RcnA) found in microorganisms that live in a wide range of environmental niches, suggesting that nickel homeostasis is a general biological concern. To date, the mechanisms of nickel toxicity in microorganisms and higher eukaryotes are poorly understood. In this review, we summarize nickel homeostasis processes used by microorganisms and highlight in vivo and in vitro effects of exposure to elevated concentrations of nickel. On the basis of this evidence we propose four mechanisms of nickel toxicity: 1) nickel replaces the essential metal of metalloproteins, 2) nickel binds to catalytic residues of non-metalloenzymes; 3) nickel binds outside the catalytic site of an enzyme to inhibit allosterically, and 4) nickel indirectly causes oxidative stress. PMID:21799955

  7. Nanoparticles of nickel hexacyanoferrate

    International Nuclear Information System (INIS)

    Bicalho, U.O.; Santos, D.C.; Silvestrini, D.R.; Trama, B.; Carmo, D.R. do

    2014-01-01

    Nanoparticles of nickel hexacyanoferrate (NHNi) were prepared in three medium (aqueous, formamide and aqueous/formamide). The materials were characterized by infrared spectroscopy (FT-IR), X-ray diffraction (XRD), electronica spectroscopy in the ultraviolet-visible (UV-Vis) region and also by cyclic voltammetry (CV). By spectroscopic analysis of X-ray diffraction was possible to estimate the size of the particles obtained by the Scherrer equation. The graphite paste electrodes containing nanoparticles of nickel hexacyanoferrate means formamide was sensitive to different concentrations of Dipyrone. (author)

  8. 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

  9. Separation and Pre-concentration of Cadmium, Copper, Lead, Nickel and Zinc by Solid-Liquid Extraction of their Cocrystallized Naphthalene Dithizone Chelate in Saline Matrices

    Directory of Open Access Journals (Sweden)

    Costa Antônio C. Spínola

    2002-01-01

    Full Text Available A procedure for separation and pre-concentration of trace amounts of cadmium, copper, lead, nickel, and zinc in brine samples has been proposed. It is based on the adsorption of metal ions onto dithizone co-crystallized with microcrystalline naphthalene, in the pH range 8.5-9.1. Nitric acid is used to back-extract the cations from the solid phase, which are measured by ICP-OES. Various parameters, such as the effect of pH, stirring time, and amounts of solid phase, have been studied in detail, to optimize the conditions for the determination of trace amounts of Cd, Cu, Pb, Ni and Zn in synthetic brine samples. The limits of detection values expressed in mug L-1 are 44 (Zn, 11 (Ni, 30 (Cd, 47 (Pb and 11 (Cu. The precision of the procedure was determined by running 10 replicate samples, each one containing 250 mug L-1 of each element and the relative standard deviations were 2.71 % (Cd, 2.15 % (Cu, 1.53 % (Pb, 2.47 % (Ni, and 2.78 % (Zn. The accuracy of the procedure was confirmed by applying the analyte additions method and the results indicated that quantitative recoveries (superscript three 95 % were obtained.

  10. Excessive nickel release from mobile phones--a persistent cause of nickel allergy and dermatitis.

    Science.gov (United States)

    Jensen, Peter; Johansen, Jeanne D; Zachariae, Claus; Menné, Torkil; Thyssen, Jacob P

    2011-12-01

    Despite the political intention to limit nickel allergy and dermatitis in Europeans, nickel allergy remains frequent. There are several explanations for the persistence of nickel allergy and dermatitis, including the increasing use of mobile phones. Before regulation of nickel release from mobile phones, we showed that eight (19.5%) of 41 mobile phones marketed in Denmark between 2003 and 2007 released nickel in concentrations that may result in nickel allergy and dermatitis. In 2009, the EU Nickel Directive was revised to include nickel-releasing mobile phones. To investigate the proportion of mobile phones sold in Denmark that release nickel after regulation. Metallic parts from 50 randomly selected mobile phones currently for sale in Denmark were tested for nickel release by use of the dimethylglyoxime (DMG)-nickel spot test. Nine (18%) phones showed at least one positive DMG test reaction and two phones had more than one DMG test-positive spot. Apparently, the proportion of mobile phones with significant nickel release remains unchanged, despite the 2009 revision of the EU Nickel Directive. We encourage manufacturers to measure nickel release from metallic components used in the assembly of mobile phones to ensure safe products. © 2011 John Wiley & Sons A/S.

  11. Effect of increasing concentrations of lead, cadmium, chromium, nickel, or zinc on lettuce grown in nutrient solution

    Energy Technology Data Exchange (ETDEWEB)

    Foroughi, M.; Hoffmann, G.; Teicher, K.; Venter, F.

    1975-01-01

    Experiments were performed to examine concentrations at which excess symptoms could be expected, which kind of damage symptoms appear and in which amount the heavy metals are enriched in roots and leaves. The following results were revealed. Lettuce (Lactuca sativa L. var. capitata L.) can tolerate amounts of Cd below 1 ppm, of Ni below 2 ppm and of Pb below 20 ppm in the nutrient solution without any symptoms of excess. The growth of lettuce was mostly influenced by Cd, least of all by Pb. Only Ni caused specific poisoning symptoms. Heavy metals were enriched in different amounts in roots and leaves. The contents of Cd and Ni were more than twice as high as those of Pb. The heavy metals influenced the uptake and distribution of macro-elements more (nitrogen) or less (potassium) vigorously.

  12. Characterization and Growth Mechanism of Nickel Nanowires Resulting from Reduction of Nickel Formate in Polyol Medium

    OpenAIRE

    Logutenko, Olga A.; Titkov, Alexander I.; Vorob’yov, Alexander M.; Yukhin, Yriy M.; Lyakhov, Nikolay Z.

    2016-01-01

    Nickel linear nanostructures were synthesized by reduction of nickel formate with hydrazine hydrate in ethylene glycol medium in the absence of any surfactants or capping agents for direction of the particles growth. The effect of the synthesis conditions such as temperature, reduction time, type of polyol, and nickel formate concentration on the reduction products was studied. The size and morphology of the nickel nanowires were characterized by X-ray diffraction, scanning, and transmission ...

  13. An improved procedure for determining grain boundary diffusion coefficients from averaged concentration profiles

    Science.gov (United States)

    Gryaznov, D.; Fleig, J.; Maier, J.

    2008-03-01

    Whipple's solution of the problem of grain boundary diffusion and Le Claire's relation, which is often used to determine grain boundary diffusion coefficients, are examined for a broad range of ratios of grain boundary to bulk diffusivities Δ and diffusion times t. Different reasons leading to errors in determining the grain boundary diffusivity (DGB) when using Le Claire's relation are discussed. It is shown that nonlinearities of the diffusion profiles in lnCav-y6/5 plots and deviations from "Le Claire's constant" (-0.78) are the major error sources (Cav=averaged concentration, y =coordinate in diffusion direction). An improved relation (replacing Le Claire's constant) is suggested for analyzing diffusion profiles particularly suited for small diffusion lengths (short times) as often required in diffusion experiments on nanocrystalline materials.

  14. Time and spatial concentration profile inside a membrane by means of a memory formalism

    Science.gov (United States)

    Caputo, Michele; Cametti, Cesare; Ruggero, Vittorio

    2008-03-01

    In this note, the profile concentration of diffusing particles inside a membrane has been calculated on the basis of the Fick diffusion equation modified by introducing a memory formalism. In highly heterogeneous systems, such as biological membranes, the intrinsic structural complexity of the medium restricts the applicability of continuum diffusion models and suggests that diffusion parameters could depend at a certain time or position on what happens at preceding times (diffusion with memory). Here, we deal with two particular cases, the diffusion of glucose across an erythrocyte membrane, when the concentration at both sides of the membrane are assigned, and the permeation transport of small molecular weight solute through an artificial hydrogel polymeric membrane. However, the present procedure can be easily extended to more general conditions. The knowledge of the concentration profile within a membranous structure, which is usually not easily experimentally accessible, completes the description of the rather complex phenomenon of the transport across a highly structured confined medium and can also lead to an improvement in controlled drug-delivery systems.

  15. Comparison of gene expression and fatty acid profiles in concentrate and forage finished beef.

    Science.gov (United States)

    Buchanan, J W; Garmyn, A J; Hilton, G G; VanOverbeke, D L; Duan, Q; Beitz, D C; Mateescu, R G

    2013-01-01

    Fatty acid profiles and intramuscular expression of genes involved in fatty acid metabolism were characterized in concentrate- (CO) and forage- (FO) based finishing systems. Intramuscular samples from the adductor were taken at slaughter from 99 heifers finished on a CO diet and 58 heifers finished on a FO diet. Strip loins were obtained at fabrication to evaluate fatty acid profiles of LM muscle for all 157 heifers by using gas chromatography fatty acid methyl ester analysis. Composition was analyzed for differences by using the General Linear Model (GLM) procedure in SAS. Differences in fatty acid profile included a greater atherogenic index, greater percentage total MUFA, decreased omega-3 to omega-6 ratio, decreased percentage total PUFA, and decreased percentage omega-3 fatty acids in CO- compared with FO-finished heifers (P0.05). Upregulation was observed for PPARγ, fatty acid synthase (FASN), and fatty acid binding protein 4 (FABP4) in FO-finished compared with CO-finished heifers in both atherogenic index categories (P<0.05). Upregulation of diglyceride acyl transferase 2 (DGAT2) was observed in FO-finished heifers with a HAI (P<0.05). Expression of steroyl Co-A desaturase (SCD) was upregulated in CO-finished heifers with a LAI, and downregulated in FO-finished heifers with a HAI (P<0.05). Expression of adiponectin (ADIPOQ) was significantly downregulated in CO-finished heifers with a HAI compared with all other categories (P<0.05). The genes identified in this study which exhibit differential regulation in response to diet or in animals with extreme fatty acid profiles may provide genetic markers for selecting desirable fatty acid profiles in future selection programs.

  16. The prediction of concentration profiles for a NIMCIX column absorbing uranium from aqueous solution

    International Nuclear Information System (INIS)

    Wright, R.S.

    1979-01-01

    A procedure is proposed for the prediction of concentration profiles for a countercurrent ion-exchange absorption column, use being made of equilibrium and kinetic data derived from small-scale batch tests. A comparison is presented between the predictions and the measured performance of a column (2,5 m in diameter) absorbing uranium from solution. The method is shown to be adequate for design purposes provided that the data used are from tests in which the solution and resin conditions approximate those for which the plant is being designed [af

  17. Use of nuclear methods for the analysis of materials and the determination of concentration profiles

    International Nuclear Information System (INIS)

    Darras, R.

    1976-01-01

    The possibilities of the activation analysis and nuclear reaction analysis are presented. These methods allow the oligo-elements and impurities (in trace amounts) to be determined in materials with accuracy and a high sensitivity. They can also be applied to the determination of major elements in a small amount of materials. Surface analysis and concentration profile determination are possible when the nature and energy of the incident particles are judiciously selected. Exemples of analysis of steels, pure iron and refractories are given [fr

  18. Radon concentrations profiles over the brazilian Amazon basin during wet season

    International Nuclear Information System (INIS)

    Pereira, E.B.; Dias, P.L.S.; Nordemann, D.J.R.

    1991-01-01

    Atmospheric radon measurements were performed airborne in the Brazilian Amazon Basin during the wet season ABLE-2B experiment. The vertical profiles of radon showed a small decrease of concentration with increasing altitude at a rate varying from 6.5 to 11 x 10 - 2 Bq m - 3 km - 1. The calculation of the flux balance of radon in the troposphere above the Amazon Basin indicated a residual flux at the upper boundary of the measurement domain (6 km) of 0.14 atom cm - 2 s - 1. This residue may be associated with the turbulent transport of radon due to cloud activity. (author)

  19. Determination of the concentration profile of chemical elements in superheater pipes

    International Nuclear Information System (INIS)

    Aldape U, F.; Aspiazu F, J.

    1986-05-01

    This work has for object to determine the profile of concentration of chemical elements at trace level in a superheater pipe of Thermoelectric Plants using the X-ray emission spectroscopy technique induced by protons coming from the Accelerator of the Nuclear Center. In the X-ray detection, a Si Li detector was used. The technique was chosen because it allows a multielemental analysis, of high sensitivity and precision. The results can help to understand the problems that are had in the change of flexibility or of corrosion. This will be from utility to the Federal Electricity Commission (CFE). (Author)

  20. Behavioral interventions to reduce nickel exposure in a nickel processing plant.

    Science.gov (United States)

    Rumchev, Krassi; Brown, Helen; Wheeler, Amanda; Pereira, Gavin; Spickett, Jeff

    2017-10-01

    Nickel is a widely-used material in many industries. Although there is enough evidence that occupational exposure to nickel may cause respiratory illnesses, allergies, and even cancer, it is not possible to stop the use of nickel in occupational settings. Nickel exposure, however, can be controlled and reduced significantly in workplaces. The main objective of this study was to assess if educational intervention of hygiene behavior could reduce nickel exposure among Indonesian nickel smelter workers. Participants were randomly assigned to three intervention groups (n = 99). Group one (n = 35) received only an educational booklet about nickel, related potential health effects and preventive measures, group two (n = 35) attended a presentation in addition to the booklet, and group three (n = 29) received personal feedback on their biomarker results in addition to the booklet and presentations. Pre- and post-intervention air sampling was conducted to measure concentrations of dust and nickel in air along with worker's blood and urine nickel concentrations. The study did not measure significant differences in particles and nickel concentrations in the air between pre- and post-interventions. However, we achieved significant reductions in the post intervention urine and blood nickel concentrations which can be attributed to changes in personal hygiene behavior. The median urinary nickel concentration in the pre-intervention period for group one was 52.3 µg/L, for group two 57.4 µg/L, and group three 43.2 µg/L which were significantly higher (pnickel with significantly (p nickel levels of 0.1 µg/L for all groups. The study showed that educational interventions can significantly reduce personal exposure levels to nickel among Indonesian nickel smelter workers.

  1. Assaying environmental nickel toxicity using model nematodes.

    Directory of Open Access Journals (Sweden)

    David Rudel

    Full Text Available Although nickel exposure results in allergic reactions, respiratory conditions, and cancer in humans and rodents, the ramifications of excess nickel in the environment for animal and human health remain largely undescribed. Nickel and other cationic metals travel through waterways and bind to soils and sediments. To evaluate the potential toxic effects of nickel at environmental contaminant levels (8.9-7,600 µg Ni/g dry weight of sediment and 50-800 µg NiCl2/L of water, we conducted assays using two cosmopolitan nematodes, Caenorhabditis elegans and Pristionchus pacificus. We assayed the effects of both sediment-bound and aqueous nickel upon animal growth, developmental survival, lifespan, and fecundity. Uncontaminated sediments were collected from sites in the Midwestern United States and spiked with a range of nickel concentrations. We found that nickel-spiked sediment substantially impairs both survival from larval to adult stages and adult longevity in a concentration-dependent manner. Further, while aqueous nickel showed no adverse effects on either survivorship or longevity, we observed a significant decrease in fecundity, indicating that aqueous nickel could have a negative impact on nematode physiology. Intriguingly, C. elegans and P. pacificus exhibit similar, but not identical, responses to nickel exposure. Moreover, P. pacificus could be tested successfully in sediments inhospitable to C. elegans. Our results add to a growing body of literature documenting the impact of nickel on animal physiology, and suggest that environmental toxicological studies could gain an advantage by widening their repertoire of nematode species.

  2. Assaying environmental nickel toxicity using model nematodes

    Science.gov (United States)

    Rudel, David; Douglas, Chandler; Huffnagle, Ian; Besser, John M.; Ingersoll, Christopher G.

    2013-01-01

    Although nickel exposure results in allergic reactions, respiratory conditions, and cancer in humans and rodents, the ramifications of excess nickel in the environment for animal and human health remain largely undescribed. Nickel and other cationic metals travel through waterways and bind to soils and sediments. To evaluate the potential toxic effects of nickel at environmental contaminant levels (8.9-7,600 µg Ni/g dry weight of sediment and 50-800 µg NiCl2/L of water), we conducted assays using two cosmopolitan nematodes, Caenorhabditis elegans and Pristionchus pacificus. We assayed the effects of both sediment-bound and aqueous nickel upon animal growth, developmental survival, lifespan, and fecundity. Uncontaminated sediments were collected from sites in the Midwestern United States and spiked with a range of nickel concentrations. We found that nickel-spiked sediment substantially impairs both survival from larval to adult stages and adult longevity in a concentration-dependent manner. Further, while aqueous nickel showed no adverse effects on either survivorship or longevity, we observed a significant decrease in fecundity, indicating that aqueous nickel could have a negative impact on nematode physiology. Intriguingly, C. elegansand P. pacificus exhibit similar, but not identical, responses to nickel exposure. Moreover, P. pacificus could be tested successfully in sediments inhospitable to C. elegans. Our results add to a growing body of literature documenting the impact of nickel on animal physiology, and suggest that environmental toxicological studies could gain an advantage by widening their repertoire of nematode species.

  3. Radiometric dating of sediment core from waterwork reservoir Rozgrund and analysis of mercury concentration depth profile

    International Nuclear Information System (INIS)

    Vanek, M.

    2005-01-01

    Radioisotope dating of lake sediments combined with analysis of chemical properties of the sediment layers allow us to study the history of the human impact on nature. Undisturbed sediment layers in the core samples serve as chronicle database with information about lake ecosystem and surrounding environment in the time of deposition. A sediment core sample from the bottom of the water-work reservoir Rozgrund was collected and separated into 2 cm thick layers. Samples were analysed by HPGe spectrometry for anthropogenous Cs-137 activity. From identified peaks corresponding to nuclear tests and Chernobyl accident the sedimentation rate was calculated and the chronology of layers established. Sub-samples from each layer were prepared separately for the analysis of the Hg concentration by atomic absorption spectrometry. The results show very small variations in Hg concentrations and there is no significant trend present in the profile. (author)

  4. The role of silicon interstitials in the deactivation and reactivation of high concentration boron profiles

    Energy Technology Data Exchange (ETDEWEB)

    Aboy, Maria [Campus Miguel Delibes, University of Valladolid, 47011 Valladolid (Spain)]. E-mail: marabo@tel.uva.es; Pelaz, Lourdes [Campus Miguel Delibes, University of Valladolid, 47011 Valladolid (Spain); Marques, Luis A. [Campus Miguel Delibes, University of Valladolid, 47011 Valladolid (Spain); Lopez, Pedro [Campus Miguel Delibes, University of Valladolid, 47011 Valladolid (Spain); Barbolla, Juan [Campus Miguel Delibes, University of Valladolid, 47011 Valladolid (Spain); Venezia, V.C. [Philips Research Leuven, Leuven (Belgium); Duffy, R. [Philips Research Leuven, Leuven (Belgium); Griffin, Peter B. [Stanford University, Stanford, CA (United States)

    2004-12-15

    Boron cluster formation and dissolution in high concentration B profiles and the role of Si interstitials in these processes are analyzed by kinetic non-lattice Monte Carlo atomistic simulations. For this purpose, we use theoretical structures as simplifications of boron implants into preamorphized Si, followed by low-temperature solid phase epitaxial (SPE) regrowth or laser thermal annealing process. We observe that in the presence of high B concentrations (above 10{sup 20} cm{sup -3}), significant deactivation occurs during high temperature anneal, even in the presence of only equilibrium Si interstitials. The presence of additional Si interstitials from an end of range (EOR) damage region accelerates the deactivation process and makes B deactivation slightly higher. We show that B deactivation and reactivation processes can be clearly correlated to the evolution of Si interstitial defects at the EOR. The minimum level of activation occurs when the Si interstitial defects at EOR dissolve or form very stable defects.

  5. Thermal Profile of the Lunar Interior Constrained by Revised Estimates of Concentrations of Heat Producing Elements

    Science.gov (United States)

    Fuqua-Haviland, H.; Panovska, S.; Mallik, A.; Bremner, P. M.; McDonough, W. F.

    2017-12-01

    Constraining the heat producing element (HPE) concentrations of the Moon is important for understanding the thermal state of the interior. The lunar HPE budget is debated to be suprachondritic [1] to chondritic [2]. The Moon is differentiated, thus, each reservoir has a distinct HPE signature complicating this effort. The thermal profile of the lunar interior has been constructed using HPE concentrations of an ordinary chondrite (U = 0.0068 ppm; Th = 0.025 ppm; K = 17 ppm) which yields a conservative low estimate [2, 3, 4]. A later study estimated the bulk lunar mantle HPE concentrations (U = 0.039 ppm; Th = 0.15 ppm; K = 212 ppm) based on measurements of Apollo pyroclastic glasses [5] assuming that these glasses represent the least fractionated, near-primary lunar mantle melts, hence, are the best proxies for capturing mantle composition. In this study, we independently validate the revised estimate by using HPE concentrations [5] to construct a conductive lunar thermal profile, or selenotherm. We compare our conductive profile to the range of valid temperatures. We demonstrate the HPE concentrations reported by [5], when used in a simple 1D spherical thermal conduction equation, yield an impossibly hot mantle with temperatures in excess of 4,000 K (Fig 1). This confirms their revised estimate is not representative of the bulk lunar mantle, and perhaps only representative of a locally enriched mantle domain. We believe that their Low-Ti avg. source estimate (Th = 0.055 ppm, Th/U=4; K/U=1700), with the least KREEP assimilation is the closest representation of the bulk lunar mantle, producing 3E-12 W/kg of heat. This estimate is close to that of the Earth (5E-12 W/kg), indicating that the bulk Earth and lunar mantles are similar in their HPE constituents. We have used the lunar mantle heat production, in conjunction with HPE estimates of the Fe-Ti-rich cumulates (high Ti-source estimate from [5]) and measurements of crustal ferroan anorthite [6], to capture the

  6. Effect of Entrainment and Overflow Occurrences on Concentration Profile in PUREX Flow Sheet

    International Nuclear Information System (INIS)

    Ueda, Yoshinori; Ishii, Junichi; Matsumoto, Shiro

    2003-01-01

    A deviation in the operational condition of a mixer settler and a centrifugal contactor causes an entrainment or an overflow, which affects the concentration profile. Although there has been no quantitative study about the effect of such abnormal flows on the concentration profile, the occurrence of such abnormal flows has been severely restricted for a PUREX flow sheet. However, the restriction of abnormal flows can be relaxed when the effect of such flows is limited within the allowable range such that the concentration of the product does not deviate from its specification. This relaxation could serve to benefit a continuous operation under a certain degree of deviation from the operational condition and a smaller design load of a solvent extractor. From this viewpoint, the relationship between the magnitude of abnormal flows and the effect of them on the process was studied quantitatively using a specially developed code in a wide range of PUREX flow sheet conditions, and the possibility of this relaxation was investigated. The results showed that the effect of the abnormal flow on the concentration in the organic outflow or aqueous raffinate was dominated by the leakage fraction under normal conditions regardless of each specific flow sheet condition. The common correlations were found between the leakage fraction of uranium and plutonium under the occurrence of abnormal flows and that under no abnormal flow for the stripping and extracting conditions, respectively. Comparing the given correlations and the usual specification of the leakage fraction of uranium and plutonium suggested that the restriction of the abnormal flows could be relaxed for a usual PUREX flow sheet

  7. Circulating Irisin Concentrations Are Associated with a Favourable Lipid Profile in the General Population.

    Directory of Open Access Journals (Sweden)

    Simon Oelmann

    Full Text Available Irisin is a myokine, which is mainly inversely associated with the risk for non-communicable diseases. Irisin improves cellular energy metabolism by uncoupling the mitochondrial respiratory chain resulting in increased energy expenditure using lipids. To date potential associations between irisin concentration and lipid profile are poorly understood. Therefore, this investigation aimed to evaluate potential associations between irisin and lipid levels in the general population.Data of 430 men and 537 women from the population-based Study of Health in Pomerania (SHIP-TREND with available irisin and lipid concentrations were used. Analyses of variance, linear and logistic regression models adjusted for age, HBA1c, waist circumference, physical activity, smoking, alcohol consumption, systolic blood pressure, ALAT were calculated.We detected significantly inverse associations between irisin and circulating levels of total [beta coefficient 0.21 (standard error 0.08, p = 0.01], low-density cholesterol [-0.16 (0.07, p = 0.03] and triglycerides [-0.17 (0.08, p = 0.02] for men. Females without lipid lowering medication had an inverse association between irisin and total cholesterol [-0.12 (0.06, p = 0.05]. Further, male subjects with irisin concentrations in the third tertile had an increased odds for elevated low-density cholesterol [odds ratio 1.96 (95% confidence interval 1.07-3.48, p = 0.03 and triglyceride [1.95 (1.09-3.47, p = 0.02] levels, even after exclusion of subjects with lipid lowering medication. In addition, our data revealed an annual rhythm of serum irisin levels with peak levels arise in winter and summer months.This is the first investigation to report a significant association between circulating irisin and a favourable lipid profile in the general population. This may infer that higher irisin concentrations are associated with a reduced risk for non-communicable diseases.

  8. Dynamic changes in amino acid concentration profiles in patients with sepsis.

    Directory of Open Access Journals (Sweden)

    Longxiang Su

    Full Text Available The goal of this work was to explore the dynamic concentration profiles of 42 amino acids and the significance of these profiles in relation to sepsis, with the aim of providing guidance for clinical therapies.Thirty-five critically ill patients with sepsis were included. These patients were further divided into sepsis (12 cases and severe sepsis (23 cases groups or survivor (20 cases and non-survivor (15 cases groups. Serum samples from the patients were collected on days 1, 3, 5, 7, 10, and 14 following intensive care unit (ICU admission, and the serum concentrations of 42 amino acids were measured.The metabolic spectrum of the amino acids changed dramatically in patients with sepsis. As the disease progressed further or with poor prognosis, the levels of the different amino acids gradually increased, decreased, or fluctuated over time. The concentrations of sulfur-containing amino acids (SAAs, especially taurine, decreased significantly as the severity of sepsis worsened or with poor prognosis of the patient. The serum concentrations of SAAs, especially taurine, exhibited weak negative correlations with the Sequential Organ Failure Assessment (SOFA (r=-0.319 and Acute Physiology and Chronic Health Evaluation (APACHE II (r=-0.325 scores. The areas under the receiver operating characteristic curves of cystine, taurine, and SAA levels and the SOFA and APACHE II scores, which denoted disease prognosis, were 0.623, 0.674, 0.678, 0.86, and 0.857, respectively.Critically ill patients with disorders of amino acid metabolism, especially of SAAs such as cystine and taurine, may provide an indicator of the need for the nutritional support of sepsis in the clinic.ClinicalTrial.gov identifier NCT01818830.

  9. Retrieval of vertical concentration profiles from OSIRIS UV-visible limb spectra

    International Nuclear Information System (INIS)

    Strong, K.; Joseph, B.M.; Dosanjh, R.; McDade, I.C.; McLinden, C.A.; McConnell, J.C.; Stegman, J.; Murtagh, D.P.; Llewellyn, E.J.

    2002-01-01

    The OSIRIS instrument, launched on the Odin satellite in February 2001, includes an optical spectrograph that will record UV-visible spectra of sunlight scattered from the limb over a range of tangent heights. These spectra will be used to retrieve vertical profiles of ozone, NO 2 , OC1O, BrO, NO 3 , O 2 , and aerosols, for the investigation of both stratospheric and mesospheric processes, particularly those related to ozone chemistry. In this work, the retrieval of vertical profiles of trace-gas concentrations from OSIRIS limb-radiance spectra is described. A forward model has been developed to simulate these spectra, and it consists of a single-scattering radiative-transfer model with partial spherical geometry, trace-gas absorption, Mic scattering by stratospheric aerosols, a Lambertian surface contribution, and OSIRIS instrument response and noise. Number-density profiles have been retrieved by using optimal estimation (OE) to combine an a priori profile with the information from sets of synthetic 'measurements'. For ozone, OE has been applied both to limb radiances at one or more discrete wavelengths and to effective-column abundances retrieved over a broad spectral range using differential optical absorption spectroscopy (DOAS). The results suggest that, between 15 and 35 km, ozone number densities can be retrieved to 10% accuracy or better on 1 and 2 km grids and to 5% on a 5 km grid. The combined DOAS-OE approach has also been used to retrieve NO 2 number densities, yielding 13% accuracy or better for altitudes from 18 to 36 km (in a 2 km grid. Differential optical absorption spectroscopy - optimal estimation retrievals of BrO and OC1O reproduce the true profiles above 15 km in the noise-free case, but the quality of the retrievals is highly sensitive to noise on the simulated OSIRIS spectra because of the weak absorption of these two gases. The development of inversion methods for the retrieval of trace-gas concentrations from OSIRIS spectra is continuing

  10. Organohalogen pollutants in herring from the northern Baltic Sea: Concentrations, congener profiles and explanatory factors

    International Nuclear Information System (INIS)

    Koistinen, Jaana; Kiviranta, Hannu; Ruokojaervi, Paeivi; Parmanne, Raimo; Verta, Matti; Hallikainen, Anja; Vartiainen, Terttu

    2008-01-01

    Organohalogen contaminants were investigated in Baltic herring caught from three catchment areas in the Baltic Sea, off the coasts of Finland. Pools of both small and large herring were analysed for polychlorinated biphenyls (PCB), dibenzo-p-dioxins, dibenzofurans, naphthalenes, camphenes (toxaphene), polybrominated diphenyl ethers and the pesticide DDT and its metabolites. PCB concentrations per fresh weight in small herring were at the same level in all catchment areas, i.e. the Bothnian Bay, the Bothnian Sea and the Gulf of Finland, revealing no hot spots and reflecting most likely long term emissions and atmospheric deposition. Differences in the levels and/or congener profiles of other contaminants between catchment areas may be explained by point sources. Similar concentrations in small and large herring in the Gulf of Finland were possibly due to their common nutrition. In the other areas, differences between small and large herring most likely reflected their different food sources. - Sources of pollutants are reflected in levels and congener profiles of pollutants in Baltic herring

  11. Nitrogen concentration profiles in oxy-nitrited high-speed steel

    International Nuclear Information System (INIS)

    Barcz, A.; Turos, A.; Wielunski, L.

    1976-01-01

    Nuclear microanalysis has been applied for the determination of in-depth concentration profiles of nitrogen in oxy-nitrided high-speed steel. The concentration profiles were deduced from measurements of the nitrogen content, determined by means of the 14 N(d,α) 12 C reaction for the set of initially identical samples after the removal of surface layers of sequentially increasing thicknesses. The 1.2 MeV deuterons were obtained from the Institute of Nuclear Research Van de Graaf accelerator LECH. The α-particles produced in the 14 N(d,α) 12 C reaction were detected by means of silicon surface barrier detector mounted at 150 deg C. Strong blocking of the nitrogen diffusion due to the presence of oxygen has been observed. The accuracy of nitrogen detection is of the order of 5% for nitrogen-rich regions and 10% for the matrix. However, the local non-uniformity of the steel may cause a spread of about 20% of the measured values. (T.G.)

  12. Duality based direct resolution of unique profiles using zero concentration region information.

    Science.gov (United States)

    Tavakkoli, Elnaz; Rajkó, Róbert; Abdollahi, Hamid

    2018-07-01

    Self Modeling Curve Resolution (SMCR) is a class of techniques concerned with estimating pure profiles underlying a set of measurements on chemical systems. In general, the estimated profiles are ambiguous (non-unique) except if some special conditions fulfilled. Implementing the adequate information can reduce the so-called rotational ambiguity effectively, and in the most desirable cases lead to the unique solution. Therefore, studies on circumstances resulting in unique solution are of particular importance. The conditions of unique solution can particularly be studied based on duality principle. In bilinear chemical (e.g., spectroscopic) data matrix, there is a natural duality between its row and column vector spaces using minimal constraints (non-negativity of concentrations and absorbances). In this article, the conditions of the unique solution according to duality concept and using zero concentration region information is intended to show. A simulated dataset of three components and an experimental system with synthetic mixtures containing three amino acids tyrosine, phenylalanine and tryptophan are analyzed. It is shown that in the presence of sufficient information, the reliable unique solution is obtained that is valuable in analytical qualification and for quantitative verification analysis. Copyright © 2018 Elsevier B.V. All rights reserved.

  13. Characterization and Growth Mechanism of Nickel Nanowires Resulting from Reduction of Nickel Formate in Polyol Medium

    Directory of Open Access Journals (Sweden)

    Olga A. Logutenko

    2016-01-01

    Full Text Available Nickel linear nanostructures were synthesized by reduction of nickel formate with hydrazine hydrate in ethylene glycol medium in the absence of any surfactants or capping agents for direction of the particles growth. The effect of the synthesis conditions such as temperature, reduction time, type of polyol, and nickel formate concentration on the reduction products was studied. The size and morphology of the nickel nanowires were characterized by X-ray diffraction, scanning, and transmission electron microscopy. It was shown that the nickel nanocrystallites were wire-shaped with a face-center-cubic phase. Ethylene glycol was found to play a crucial role in the formation of the nickel nanowires. The possible growth processes of the wire-shaped particles taking place at 110 and 130°C are discussed. It was shown that, under certain synthesis conditions, nickel nanowires grow on the surface of the crystals of the solid intermediate of nickel with hydrazine hydrate.

  14. Dislocation loops and their depth profiles in He[sup +] and D[sup +] ion irradiated nickel

    Energy Technology Data Exchange (ETDEWEB)

    Niwase, K [Dept. of Physics, Hyogo Univ. of Teacher Education, Yashiro (Japan); Ezawa, T [Dept. of Material Physics, Faculty of Engineering Science, Osaka Univ., Toyonaka (Japan); Tanabe, T [Dept. of Nuclear Engineering, Faculty of Engineering, Osaka Univ., Suita (Japan); Kiritani, M [Dept. of Nuclear Engineering, School of Engineering, Nagoya Univ. (Japan); Fujita, F E [Dept. of Material Physics, Faculty of Engineering Science, Osaka Univ., Toyonaka (Japan)

    1993-07-01

    Effects of implanted deuterium and helium on the formation of dislocation loops in Ni have been systematically investigated in terms of the irradiation temperature and dose by means of transmission electron microscopy. Significant enhancement of loop formation is observed only for He[sup +] irradiation. The number density of loops at 200 C for He[sup +] irradiation is about one order of magnitude higher than that of D[sup +] irradiation and the difference increases at higher temperatures. Significant decrease in the density occurs at about 300 C for D[sup +] irradiation, but it appears at about 600 C for He[sup +] irradiation. Below 200 C, continuous nucleation of loops is observed only for He[sup +] irradiation. The change in the loop depth distribution suggests that the nucleation of loops for He[sup +] irradiation is enhanced by some defects with a low mobility such as small He-vacancy complexes. The significant decrease in the loop density above 600 C is explained by the decrease in the concentration of the small He-vacancy complexes due to their absorption by large cavities or their escape to the specimen surface. (orig.)

  15. Aluminium and nickel in human albumin solutions

    DEFF Research Database (Denmark)

    Gammelgaard, Bente; Sandberg, E

    1989-01-01

    Five different brands of commercially available human albumin solutions for infusion were analysed for their aluminium and nickel contents by atomic absorption spectrometry. The aluminium concentrations ranged from 12 micrograms/l to 1109 micrograms/l and the nickel concentrations ranged from 17...... micrograms/l to 77 micrograms/l. Examination of the aluminium and nickel contents of the constituents for the production of one brand showed too low levels to explain the final contamination of the product. By following the aluminium and nickel concentrations of the same brand during the production...... of a batch of albumin solution, filtration was shown to contribute to contamination, although the largest increase in aluminium as well as nickel concentrations appeared during the bulk concentrating process. To avoid health risks to certain patients, regulations should be established requiring aluminium...

  16. Occupational exposure to nickel salts in electrolytic plating.

    Science.gov (United States)

    Kiilunen, M; Aitio, A; Tossavainen, A

    1997-04-01

    An occupational hygiene survey was made in 38 nickel plating shops in Finland and exposure to nickel was studied by means of biological measurements and, in three shops, by using air measurements. The average after-shift urinary nickel concentration of 163 workers was 0.16 mumol l.-1 (range 0.001-4.99 mumol l.-1). After the 1-5 week vacation the urinary nickel concentration was higher than the upper reference limit of non-exposed Finns indicating that a part of water-soluble nickel salts is accumulated in the body. Urinary nickel concentrations in the shops considered clean in the industrial hygiene walk-through were not different from those observed in the shops considered dirty. The correlation between the concentrations of nickel in the air and in the urine was low, and the amount of nickel excreted in the urine exceeded the calculated inhaled amounts, indicating exposure by other routes such as ingestion.

  17. Spectroscopic Analysis of Ion Concentration Profile at Electrode/Electrolyte Interface by Interferometry

    Science.gov (United States)

    Moore, David; Saraf, Ravi

    2014-03-01

    Owing to the difference in Fermi levels at an electrode/electrolyte interface, ions form an electrical double layer (EDL) with ion concentrations well over 10-fold compared to bulk. The concentration profile of the EDL intrinsically affects the electrochemical reaction rates at the electrode, which is of great significance in many applications, such as batteries and biosensors. Conventionally, using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), the electrical properties of the EDL are represented as ``equivalent circuits'' consisting of the resistance to charge transfer (Rct), the double layer capacitance (Cdl) and a ``Warburg (constant phase) diffusion element'' that represents the long range diffusion of ions to the electrode. The translation to the well-understood physical structure can be lost as complicated effects are often lumped together. For example, the effect of subtle modification of the electrode surface by say, redox compounds, enzymes, or polymers is not directly measured, and must be inferred by capacitance changes. An interferometer method will be described to directly measure changes in concentration at the interface during redox process. This method in concert with CV or EIS performed concomitantly will lead to more information to model the diffuse layer for improved understanding of the kinetics of the reaction at different distances from the electrode. Applications to DNA and polymer adsorption binding will be discussed.

  18. Gold, nickel and copper mining and processing.

    Science.gov (United States)

    Lightfoot, Nancy E; Pacey, Michael A; Darling, Shelley

    2010-01-01

    Ore mining occurs in all Canadian provinces and territories except Prince Edward Island. Ores include bauxite, copper, gold, iron, lead and zinc. Workers in metal mining and processing are exposed, not only to the metal of interest, but also to various other substances prevalent in the industry, such as diesel emissions, oil mists, blasting agents, silica, radon, and arsenic. This chapter examines cancer risk related to the mining of gold, nickel and copper. The human carcinogenicity of nickel depends upon the species of nickel, its concentration and the route of exposure. Exposure to nickel or nickel compounds via routes other than inhalation has not been shown to increase cancer risk in humans. As such, cancer sites of concern include the lung, and the nasal sinus. Evidence comes from studies of nickel refinery and leaching, calcining, and sintering workers in the early half of the 20th century. There appears to be little or no detectable risk in most sectors of the nickel industry at current exposure levels. The general population risk from the extremely small concentrations detectable in ambient air are negligible. Nevertheless, animal carcinogenesis studies, studies of nickel carcinogenesis mechanisms, and epidemiological studies with quantitative exposure assessment of various nickel species would enhance our understanding of human health risks associated with nickel. Definitive conclusions linking cancer to exposures in gold and copper mining and processing are not possible at this time. The available results appear to demand additional study of a variety of potential occupational and non-occupational risk factors.

  19. Highly selective micro-sequential injection lab-on-valve (muSI-LOV) method for the determination of ultra-trace concentrations of nickel in saline matrices using detection by electrothermal atomic absorption spectrometry.

    Science.gov (United States)

    Long, Xiangbao; Miró, Manuel; Jensen, Rikard; Hansen, Elo Harald

    2006-10-01

    A highly selective procedure is proposed for the determination of ultra-trace level concentrations of nickel in saline aqueous matrices exploiting a micro-sequential injection Lab-On-Valve (muSI-LOV) sample pretreatment protocol comprising bead injection separation/pre-concentration and detection by electrothermal atomic absorption spectrometry (ETAAS). Based on the dimethylglyoxime (DMG) reaction used for nickel analysis, the sample, as contained in a pH 9.0 buffer, is, after on-line merging with the chelating reagent, transported to a reaction coil attached to one of the external ports of the LOV to assure sufficient reaction time for the formation of Ni(DMG)(2) chelate. The non-ionic coordination compound is then collected in a renewable micro-column packed with a reversed-phase copolymeric sorbent [namely, poly(divinylbenzene-co-N-vinylpyrrolidone)] containing a balanced ratio of hydrophilic and lipophilic monomers. Following elution by a 50-muL methanol plug in an air-segmented modality, the nickel is finally quantified by ETAAS. Under the optimized conditions and for a sample volume of 1.8 mL, a retention efficiency of 70 % and an enrichment factor of 25 were obtained. The proposed methodology showed a high tolerance to the commonly encountered alkaline earth matrix elements in environmental waters, that is, calcium and magnesium, and was successfully applied for the determination of nickel in an NIST standard reference material (NIST 1640-Trace elements in natural water), household tap water of high hardness and local seawater. Satisfying recoveries were achieved for all spiked environmental water samples with maximum deviations of 6 %. The experimental results for the standard reference material were not statistically different to the certified value at a significance level of 0.05.

  20. Fabrication of Graded Porous and Skin-Core Structure RDX-Based Propellants via Supercritical CO2 Concentration Profile

    Science.gov (United States)

    Yang, Weitao; Li, Yuxiang; Ying, Sanjiu

    2015-04-01

    A fabrication process to produce graded porous and skin-core structure propellants via supercritical CO2 concentration profile is reported in this article. It utilizes a partial gas saturation technique to obtain nonequilibrium gas concentration profiles in propellants. Once foamed, the propellant obtains a graded porous or skin-pore structure. This fabrication method was studied with RDX(Hexogen)-based propellant under an SC-CO2 saturation condition. The principle was analyzed and the one-dimensional diffusion model was employed to estimate the gas diffusion coefficient and to predict the gas concentration profiles inside the propellant. Scanning electron microscopy images were used to analyze the effects of partial saturation on the inner structure. The results also suggested that the sorption time and desorption time played an important role in gas profile generation and controlled the inner structure of propellants.

  1. Application of PAH concentration profiles in lake sediments as indicators for smelting activity.

    Science.gov (United States)

    Warner, Wiebke; Ruppert, Hans; Licha, Tobias

    2016-09-01

    The ability of lake sediment cores to store long-term anthropogenic pollution establishes them as natural archives. In this study, we focus on the influence of copper shale mining and smelting in the Mansfeld area of Germany, using the depth profiles of two sediment cores from Lake Süßer See. The sediment cores provide a detailed chronological deposition history of polycyclic aromatic hydrocarbons (PAHs) and heavy metals in the studied area. Theisen sludge, a fine-grained residue from copper shale smelting, reaches the lake via deflation by wind or through riverine input; it is assumed to be the main source of pollution. To achieve the comparability of absolute contaminant concentrations, we calculated the influx of contaminants based on the sedimentation rate. Compared to the natural background concentrations, PAHs are significantly more enriched than heavy metals. They are therefore more sensitive and selective for source apportionment. We suggest two diagnostic ratios of PAHs to distinguish between Theisen sludge and its leachate: the ratio fluoranthene to pyrene ~2 and the ratio of PAH with logKOW5.7 converging to an even lower value than 2.3 (the characteristic of Theisen sludge) to identify the particulate input in lake environments. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Elastic recoil detection analysis for the determination of hydrogen concentration profiles in switchable mirrors

    International Nuclear Information System (INIS)

    Huisman, M.C.; Molen, S.J. van der; Vis, R.D.

    1999-01-01

    Switchable mirrors [J.N. Huiberts, R. Griessen, J.H. Rector, R.J. Wijngaarden, J.P. Dekker, D.G. de Groot, N.J. Koeman, Nature 380 (1996) 231; J.N Huiberts, J.H. Rector, R.J. Wijngaarden, S. Jetten, D. de Groot, B. Dam, N.J.. Koeman, R. Griessen, B. Hjoervarsson, S Olafsson, Y.S. Cho, J. Alloys and Compounds 239 (1996) 158; F.J.A. den Broeder, S.J. van der Molen, M. Kremers, J. N. Huiberts, D.G. Nagengast, A.T.M. van Gogh, W.H. Huisman, N. J. Koeman, B. Dam, J.H. Rector, S. Plota, M. Haaksma, R.M.N. Hanzen, R.M. Jungblut, P.A. Duine, R. Griessen, Nature 394 (1998) 656] made of thin films of Y, La or rare-earth (RE) metals exhibit spectacular changes in their optical and electrical properties upon hydrogen loading. The study of these materials has indicated that the occurring phenomena are highly sensitive to the actual hydrogen concentration in these materials. In this paper elastic recoil detection analysis (ERDA) is used as a tool to measure hydrogen concentrations on a micrometer scale. The measurements have been performed using a 4 He 2+ ion beam from a 1.7 MV Pelletron accelerator. The ion beam can be focused routinely to a spot size of approximately 10 μm 2 . The experimental set-up enables the simultaneous measurement of Rutherford backscattering spectrometry (RBS) as well as particle induced X-ray emission (PIXE) spectra, which provide complementary information. The results of ERDA measurements on laterally diffused YH x (0< x<3) samples with a qualitatively known hydrogen concentration profile are presented and discussed. The calibration of the microbeam set-up and possible improvement of the measurement technique are described

  3. Elastic recoil detection analysis for the determination of hydrogen concentration profiles in switchable mirrors

    Energy Technology Data Exchange (ETDEWEB)

    Huisman, M.C. E-mail: huisman@nat.vu.nl; Molen, S.J. van der; Vis, R.D

    1999-09-02

    Switchable mirrors [J.N. Huiberts, R. Griessen, J.H. Rector, R.J. Wijngaarden, J.P. Dekker, D.G. de Groot, N.J. Koeman, Nature 380 (1996) 231; J.N Huiberts, J.H. Rector, R.J. Wijngaarden, S. Jetten, D. de Groot, B. Dam, N.J.. Koeman, R. Griessen, B. Hjoervarsson, S Olafsson, Y.S. Cho, J. Alloys and Compounds 239 (1996) 158; F.J.A. den Broeder, S.J. van der Molen, M. Kremers, J. N. Huiberts, D.G. Nagengast, A.T.M. van Gogh, W.H. Huisman, N. J. Koeman, B. Dam, J.H. Rector, S. Plota, M. Haaksma, R.M.N. Hanzen, R.M. Jungblut, P.A. Duine, R. Griessen, Nature 394 (1998) 656] made of thin films of Y, La or rare-earth (RE) metals exhibit spectacular changes in their optical and electrical properties upon hydrogen loading. The study of these materials has indicated that the occurring phenomena are highly sensitive to the actual hydrogen concentration in these materials. In this paper elastic recoil detection analysis (ERDA) is used as a tool to measure hydrogen concentrations on a micrometer scale. The measurements have been performed using a {sup 4}He{sup 2+} ion beam from a 1.7 MV Pelletron accelerator. The ion beam can be focused routinely to a spot size of approximately 10 {mu}m{sup 2}. The experimental set-up enables the simultaneous measurement of Rutherford backscattering spectrometry (RBS) as well as particle induced X-ray emission (PIXE) spectra, which provide complementary information. The results of ERDA measurements on laterally diffused YH{sub x} (0concentration profile are presented and discussed. The calibration of the microbeam set-up and possible improvement of the measurement technique are described.

  4. Genome-centric evaluation of Burkholderia sp. strain SRS-W-2-2016 resistant to high concentrations of uranium and nickel isolated from the Savannah River Site (SRS, USA

    Directory of Open Access Journals (Sweden)

    Ashish Pathak

    2017-06-01

    Full Text Available Savannah River Site (SRS, an approximately 800-km2 former nuclear weapons production facility located near Aiken, SC remains co-contaminated by heavy metals and radionuclides. To gain a better understanding on microbially-mediated bioremediation mechanisms, several bacterial strains resistant to high concentrations of Uranium (U and Nickel (Ni were isolated from the Steeds Pond soils located within the SRS site. One of the isolated strains, designated as strain SRS-W-2-2016, grew robustly on both U and Ni. To fully understand the arsenal of metabolic functions possessed by this strain, a draft whole genome sequence (WGS was obtained, assembled, annotated and analyzed. Genome-centric evaluation revealed the isolate to belong to the Burkholderia genus with close affiliation to B. xenovorans LB400, an aggressive polychlorinated biphenyl-degrader. At a coverage of 90×, the genome of strain SRS-W-2-2016 consisted of 8,035,584 bases with a total number of 7071 putative genes assembling into 191 contigs with an N50 contig length of 134,675 bases. Several gene homologues coding for resistance to heavy metals/radionuclides were identified in strain SRS-W-2-2016, such as a suite of outer membrane efflux pump proteins similar to nickel/cobalt transporter regulators, peptide/nickel transport substrate and ATP-binding proteins, permease proteins, and a high-affinity nickel-transport protein. Also noteworthy were two separate gene fragments in strain SRS-W-2-2016 homologous to the spoT gene; recently correlated with bacterial tolerance to U. Additionally, a plethora of oxygenase genes were also identified in the isolate, potentially involved in the breakdown of organic compounds facilitating the strain's successful colonization and survival in the SRS co-contaminated soils. The WGS project of Burkholderia sp. strain SRS-W-2-2016 is available at DDBJ/ENA/GenBank under the accession #MSDV00000000.

  5. Nickel Inhibits Mitochondrial Fatty Acid Oxidation

    Science.gov (United States)

    Uppala, Radha; McKinney, Richard W.; Brant, Kelly A.; Fabisiak, James P.; Goetzman, Eric S.

    2015-01-01

    Nickel exposure is associated with changes in cellular energy metabolism which may contribute to its carcinogenic properties. Here, we demonstrate that nickel strongly represses mitochondrial fatty acid oxidation—the pathway by which fatty acids are catabolized for energy—in both primary human lung fibroblasts and mouse embryonic fibroblasts. At the concentrations used, nickel suppresses fatty acid oxidation without globally suppressing mitochondrial function as evidenced by increased glucose oxidation to CO2. Pre-treatment with L-carnitine, previously shown to prevent nickel-induced mitochondrial dysfunction in neuroblastoma cells, did not prevent the inhibition of fatty acid oxidation. The effect of nickel on fatty acid oxidation occurred only with prolonged exposure (>5 hr), suggesting that direct inhibition of the active sites of metabolic enzymes is not the mechanism of action. Nickel is a known hypoxia-mimetic that activates hypoxia inducible factor-1α (HIF1α). Nickel-induced inhibition of fatty acid oxidation was blunted in HIF1α knockout fibroblasts, implicating HIF1α as one contributor to the mechanism. Additionally, nickel down-regulated the protein levels of the key fatty acid oxidation enzyme very long-chain acyl-CoA dehydrogenase (VLCAD) in a dose-dependent fashion. In conclusion, inhibition of fatty acid oxidation by nickel, concurrent with increased glucose metabolism, represents a form of metabolic reprogramming that may contribute to nickel-induced carcinogenesis. PMID:26051273

  6. Nickel release from inexpensive jewelry and hair clasps purchased in an EU country - Are consumers sufficiently protected from nickel exposure?

    DEFF Research Database (Denmark)

    Thyssen, Jacob Pontoppidan; Menné, Torkil; Johansen, Jeanne Duus

    2009-01-01

    BACKGROUND: Nickel allergic subjects are at risk factor of acquiring hand eczema. In 1990 and 1994, respectively, Denmark and member states in the EU regulated nickel release from selected consumer products. The intention was that the nickel epidemic could be controlled and prevented if the general...... population was protected from high cutaneous nickel concentrations. Despite a decrease, the prevalence of nickel allergy remains high as nearly 10% of young women are nickel allergic. OBJECTIVE: This study aimed to perform dimethylglyoxime (DMG) testing of inexpensive jewelry and hair clasps purchased from...

  7. One year of Seaglider dissolved oxygen concentration profiles at the PAP site

    Science.gov (United States)

    Binetti, Umberto; Kaiser, Jan; Heywood, Karen; Damerell, Gillian; Rumyantseva, Anna

    2015-04-01

    Oxygen is one of the most important variables measured in oceanography, influenced both by physical and biological factors. During the OSMOSIS project, 7 Seagliders were used in 3 subsequent missions to measure a multidisciplinary suite of parameters at high frequency in the top 1000 m of the water column for one year, from September 2012 to September 2013. The gliders were deployed at the PAP time series station (nominally at 49° N 16.5° W) and surveyed the area following a butterfly-shaped path. Oxygen concentration was measured by Aanderaa optodes and calibrated using ship CTD O2 profiles during 5 deployment and recovery cruises, which were in turn calibrated by Winkler titration of discrete samples. The oxygen-rich mixed layer deepens in fall and winter and gets richer in oxygen when the temperature decreases. The spring bloom did not happen as expected, but instead the presence of a series of small blooms was measured throughout spring and early summer. During the summer the mixed layer become very shallow and oxygen concentrations decreased. A Deep Oxygen Maximum (DOM) developed along with a deep chlorophyll maximum during the summer and was located just below the mixed layer . At this depth, phytoplankton had favourable light and nutrient conditions to grow and produce oxygen, which was not subject to immediate outgassing. The oxygen concentration in the DOM was not constant, but decreased, then increased again until the end of the mission. Intrusions of oxygen rich water are also visible throughout the mission. These are probably due to mesoscale events through the horizontal transport of oxygen and/or nutrients that can enhance productivity, particularly at the edge of the fronts. We calculate net community production (NCP) by analysing the variation in oxygen with time. Two methods have been proposed. The classical oxygen budget method assumes that changes in oxygen are due to the sum of air-sea flux, isopycnal advection, diapycnal mixing and NCP. ERA

  8. Height profile of particle concentration in an aeolian saltating cloud: A wind tunnel investigation by PIV MSD

    Science.gov (United States)

    Dong, Zhibao; Wang, Hongtao; Zhang, Xiaohang; Ayrault, Michael

    2003-10-01

    Attempt is made to define the particle concentration in an aeolian saltating cloud and its variation with height using artificial spherical quartz sand in a wind tunnel. The height profiles of the relative particle concentration in aeolian saltating cloud at three wind velocities were detected by the state of the art PIV (Particle Image Velocimetry) MSD (Mie Scattering Diffusion) technique, and converted to actual concentration based on sand transport rate and the variation with height of velocity of the saltating cloud. The particle concentration was found to decay exponentially with height and to increase with wind velocity. It decayed more rapidly when the wind velocity decreased. The volume/volume concentration in the near-surface layer was at the order of 10-4. The results obtained by PIV MSD technique were in good agreement with those derived from the sand flux and velocity profiles, the former being about 15% greater than the later.

  9. Quantitative analysis of chromium concentration in nickel based alloys by laser induced breakdown spectroscopy at atmospheric pressure using a nanosecond ultraviolet Nd:YAG laser

    International Nuclear Information System (INIS)

    Gupta, G.P.; Suri, B.M.; Verma, A.; Sundararaman, M.; Unnikrishnan, V.K.; Alti, K.; Kartha, V.B.; Santhosh, C.

    2010-01-01

    Laser-induced breakdown spectroscopy (LIBS) has been well recognized as a simple, fast and direct analytical technique of elemental analysis of multi-element materials by a number of research groups all over the world. It is based on the focusing of a high-power pulsed laser beam with a power density > 100 MW/cm 2 onto a sample surface followed by optical emission spectroscopy of the plasma produced over the surface. In the present work, they have carried out the quantitative analysis of chromium in nickel-based-alloys using laser-induced breakdown spectroscopy (LIBS) in air at atmospheric pressure. In the present work the quantitative analysis of chromium in nickel-based-alloys using laser-induced break-down spectroscopy (LIBS) in air at atmospheric pressure has been carried out

  10. Combined cycling and calendar capacity fade modeling of a Nickel-Manganese-Cobalt Oxide Cell with real-life profile validation

    DEFF Research Database (Denmark)

    de Hoog, Joris; Timmermans, Jean-Marc; Stroe, Daniel-Ioan

    2017-01-01

    This paper presents the development of a semi-empirical combined lifetime model for a Nickel Manganese Cobalt Oxide (NMC) cathode and a graphite anode based cell, considered as one of the most promising candidates for the automotive industry. The development of this model was based on a thorough...

  11. Artificial neural networks to evaluate the boron concentration decreasing profile in Blood-BPA samples of BNCT patients

    International Nuclear Information System (INIS)

    García-Reiriz, Alejandro; Magallanes, Jorge; Zupan, Jure; Líberman, Sara

    2011-01-01

    For the prediction of decay concentration profiles of the p-boronophenylalanine (BPA) in blood during BNCT treatment, a method is suggested based on Kohonen neural networks. The results of a model trained with the concentration profiles from the literature are described. The prediction of the model was validated by the leave-one-out method. Its robustness shows that it is mostly independent on small variations. The ability to fit retrospective experimental data shows an uncertainty lower than the two compartment model used previously. - Highlights: ► We predicted decaying concentration profiles of BPA in blood during BNCT therapy. ► Is suggested a method based on Kohonen neural networks. ► The results show that it is very robust and mostly independent of small variations. ► It has a better ability to fit retrospective experimental data. ► The model could be progressively improved by adding new data to the training matrix.

  12. Effects of dietary gossypol concentration on growth performance, blood profiles, and hepatic histopathology in meat ducks.

    Science.gov (United States)

    Zeng, Q F; Yang, G L; Liu, G N; Wang, J P; Bai, S P; Ding, X M; Luo, Y H; Zhang, K Y

    2014-08-01

    The objective of this study was to determine the effects of gossypol from cottonseed meal (CSM) on growth performance, blood biochemical profiles, and liver histopathology of ducks. A total of 900 1-d-old ducks were randomly allocated to 5 treatments with 12 pens/treatment and 15 ducks/pen. The 5 experimental diets were formulated in such a way that 0% (a corn-soybean meal basal diet, diet 1), 25% (diet 2), 50% (diet 3), 75% (diet 4), and 100% (diet 5) of protein from soybean meal were replaced with that from CSM. All diets were formulated on a digestible amino acid basis. The experiment included 2 phases, the starter phase (1 to 3 wk) where the test diets contained graded levels of CSM and the growth phase (4 to 5 wk) where birds were fed a corn-soybean basal diet to examine the recovery of ducks after CSM withdrawal. Dietary CSM and gossypol linearly (P ducks among all treatments. These results suggest that meat ducks' dietary TG and FG concentration should be lower than 928.9 and 77.2 mg/kg, respectively, during d 1 to 21 of age and that a 2-wk withdrawal of diets containing gossypol should be considered. © Poultry Science Association Inc.

  13. User characteristics and effect profile of Butane Hash Oil: An extremely high-potency cannabis concentrate.

    Science.gov (United States)

    Chan, Gary C K; Hall, Wayne; Freeman, Tom P; Ferris, Jason; Kelly, Adrian B; Winstock, Adam

    2017-09-01

    Recent reports suggest an increase in use of extremely potent cannabis concentrates such as Butane Hash Oil (BHO) in some developed countries. The aims of this study were to examine the characteristics of BHO users and the effect profiles of BHO. Anonymous online survey in over 20 countries in 2014 and 2015. Participants aged 18 years or older were recruited through onward promotion and online social networks. The overall sample size was 181,870. In this sample, 46% (N=83,867) reported using some form of cannabis in the past year, and 3% reported BHO use (n=5922). Participants reported their use of 7 types of cannabis in the past 12 months, the source of their cannabis, reasons for use, use of other illegal substances, and lifetime diagnosis for depression, anxiety and psychosis. Participants were asked to rate subjective effects of BHO and high potency herbal cannabis. Participants who reported a lifetime diagnosis of depression (OR=1.15, p=0.003), anxiety (OR=1.72, pcannabis. BHO users also reported stronger negative effects and less positive effects when using BHO than high potency herbal cannabis (pcannabis. Copyright © 2017. Published by Elsevier B.V.

  14. Transportable lidar for the measurement of ozone concentration and flux profiles in the lower troposphere

    International Nuclear Information System (INIS)

    Zhao, Yanzeng; Howell, J.N.; Hardesty, R.M.

    1992-01-01

    In many areas of the United States, as well as in other industrial areas (such as Europe), elevated and potentially harmful levels of ozone are being measured during summer. Most of this ozone is photochemically produced. The relatively long lifetime of ozone allows industrially produced ozone to be transported on a hemispheric scale. Since the trends of tropospheric ozone are very likely dependent on the source strengths and distributions of the pollutants and the chemical/ transport process involved, a predictive understanding of tropospheric ozone climatology requires a focus on the chemical and transport processes that link regional emissions to hemispheric ozone trends and distributions. Of critical importance to these studies is a satisfactory data base of tropospheric ozone distribution from which global and regional tropospheric ozone climatology can be derived, and the processes controlling tropospheric ozone can be better understood. A transportable lidar for measuring ozone concentration and flux profiles in the lower troposphere is needed. One such system is being developed at the National Oceanic and Atmospheric Administration/Earth Resources Laboratory (NOAA/ERL) Wave Propagation Laboratory (WPL)

  15. Quantification and Analysis of Suspended Sediments Concentration Using Mobile and Static Acoustic Doppler Current Profiler Instruments

    Directory of Open Access Journals (Sweden)

    Angga Dwinovantyo

    2017-01-01

    Full Text Available The application of Acoustic Doppler Current Profiler (ADCP can be used not only for measuring ocean currents, but also for quantifying suspended sediment concentrations (SSC from acoustic backscatter strength based on sonar principle. Suspended sediment has long been recognized as the largest sources of sea contaminant and must be considered as one of the important parameters in water quality of seawater. This research was to determine SSC from measured acoustic backscattered intensity of static and mobile ADCP. In this study, vertically mounted 400 kHz and 750 kHz static ADCP were deployed in Lembeh Strait, North Sulawesi. A mobile ADCP 307.2 kHz was also mounted on the boat and moved to the predefined cross-section, accordingly. The linear regression analysis of echo intensity measured by ADCP and by direct measurement methods showed that ADCP is a reliable method to measure SSC with correlation coefficient (r 0.92. Higher SSC was observed in low water compared to that in high water and near port area compared to those in observed areas. All of this analysis showed that the combination of static and mobile ADCP methods produces reasonably good spatial and temporal data of SSC.

  16. Engineered nickel oxide nanoparticle causes substantial physicochemical perturbation in plants

    Science.gov (United States)

    Manna, Indrani; Bandyopadhyay, Maumita

    2017-11-01

    Concentration of engineered NiO-NP in nature is on the rise, owing to large scale industrial uses and human interventions, which have accreted the scope of exposure especially at the primary trophic levels of the ecosystem. Nickel content in air, drinking water and soil is already above permissible limits in most parts of the developed world. Though nickel oxide is an essential micronutrient in the animal system, it has already been graded as a human carcinogen by WHO, and numerous studies have established the toxic nature of nickel in higher dosage in the animal system. Though studies depicting toxicity and bioaccumulation of nickel in plants is documented, the interaction of nickel oxide nanoparticle with plants is not fully a well-studied, well elucidated topic. What is known is that, exposure to nickel oxide nanoparticle, arouses stress response and leads to cytotoxicity and growth retardation in a handful of plants, a defined work on the intricate physicochemical cellular responses and genotoxic challenges has been so far absent. We have tried to fill in such gaps with this study. We planned the work around pertinent hypotheses like: whether NiO-NP cause cytotoxicity in a model plant system (Allium cepa L.)?If so, does internalization of nickel ion (the potent toxic) take place in the tissue? Does internalized NiO-NP create furore in the antioxidant enzyme system of the plant leading to cytotoxicity? In that case, whether the ENP causes genotoxicity and leads to pycknosis of the cell. The study has been designed to assess the change in biochemical profile and genotoxicity potential of NiO-NP at a wide range of concentrations using root tips of Allium cepa L., the model system for study of cytotoxicity and genotoxicity, and four of its closest relatives, Allium sativum L., Allium schoenoprasum L., Allium porrum L., Allium fistulosum L., chosen for their immense economic importance. Growing root tips were treated with seven different concentrations of Ni

  17. Biological role of nickel

    Energy Technology Data Exchange (ETDEWEB)

    Thauer, R K; Diekert, G; Schoenheit, P

    1980-01-01

    Several enzymes and one cofactor have recently been shown to contain nickel. For example, urease of jack beans has been found to be a nickel protein and factor F/sub 430/ from methanogenic bacteria to be a nickel tetrapyrrole. The biological role of nickel in several organisms is discussed.

  18. Changes in polyphenol profile of dried apricots containing SO2 at various concentrations during storage.

    Science.gov (United States)

    Altındağ, Melek; Türkyılmaz, Meltem; Özkan, Mehmet

    2018-05-01

    Changes in polyphenols have important effects on the quality (especially color) and health benefits of dried apricots. SO 2 concentration, storage and the activities of polyphenol oxidase (PPO) and phenylalanine ammonia lyase (PAL) were factors which had significant effects on polyphenols. Polyphenol profile and activities of PPO and PAL in sulfured dried apricots (SDAs, 0, 451, 832, 2112 and 3241 mg SO 2 kg -1 ) were monitored during storage at 4, 20 and 30 °C for 379 days for the first time. Even the lowest SO 2 concentration (451 mg kg -1 ) was sufficient to inactivate PPO during the entire storage period. However, while SO 2 led to the increase in PAL activity of the samples (r = 0.767) before storage, PAL activities of SDAs decreased during storage. After 90 days of storage, PAL activity was determined in only non-sulfured dried apricots (NSDAs) and dried apricots containing 451 mg SO 2 kg -1 . Although the major polyphenol in NSDAs was epicatechin (611.4 mg kg -1 ), that in SDAs was chlorogenic acid (455-1508 mg kg -1 ), followed by epicatechin (0-426.8 mg kg -1 ), rutin (148.9-477.3 mg kg -1 ), ferulic acid (23.3-55.3 mg kg -1 ) and gallic acid (2.4-43.6 mg kg -1 ). After storage at 30 °C for 379 days, the major polyphenol in SDAs was gallic acid (706-2324 mg kg -1 ). However, the major polyphenol in NSDAs did not change after storage. The highest total polyphenol content was detected in SDAs containing 2112 mg SO 2 kg -1 and stored at 30 °C. To produce dried apricots having high polyphenol content, ∼2000 mg SO 2 kg -1 should be used. Low storage temperature (<30 °C) was not necessary for the protection of polyphenols. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  19. Glucose ameliorates the metabolic profile and mitochondrial function of platelet concentrates during storage in autologous plasma

    Science.gov (United States)

    Amorini, Angela M.; Tuttobene, Michele; Tomasello, Flora M.; Biazzo, Filomena; Gullotta, Stefano; De Pinto, Vito; Lazzarino, Giuseppe; Tavazzi, Barbara

    2013-01-01

    Background It is essential that the quality of platelet metabolism and function remains high during storage in order to ensure the clinical effectiveness of a platelet transfusion. New storage conditions and additives are constantly evaluated in order to achieve this. Using glucose as a substrate is controversial because of its potential connection with increased lactate production and decreased pH, both parameters triggering the platelet lesion during storage. Materials and methods In this study, we analysed the morphological status and metabolic profile of platelets stored for various periods in autologous plasma enriched with increasing glucose concentrations (13.75, 27.5 and 55 mM). After 0, 2, 4, 6 and 8 days, high energy phosphates (ATP, GTP, ADP, AMP), oxypurines (hypoxanthine, xanthine, uric acid), lactate, pH, mitochondrial function, cell lysis and morphology, were evaluated. Results The data showed a significant dose-dependent improvement of the different parameters in platelets stored with increasing glucose, compared to what detected in controls. Interestingly, this phenomenon was more marked at the highest level of glucose tested and in the period of time generally used for platelet transfusion (0–6 days). Conclusion These results indicate that the addition of glucose during platelet storage ameliorates, in a dose-dependent manner, the biochemical parameters related to energy metabolism and mitochondrial function. Since there was no correspondence between glucose addition, lactate increase and pH decrease in our experiments, it is conceivable that platelet derangement during storage is not directly caused by glucose through an increase of anaerobic glycolysis, but rather to a loss of mitochondrial functions caused by reduced substrate availability. PMID:22682337

  20. Respiratory carcinogenicity assessment of soluble nickel compounds.

    Science.gov (United States)

    Oller, Adriana R

    2002-10-01

    The many chemical forms of nickel differ in physicochemical properties and biological effects. Health assessments for each main category of nickel species are needed. The carcinogenicity assessment of water-soluble nickel compounds has proven particularly difficult. Epidemiologic evidence indicates an association between inhalation exposures to nickel refinery dust containing soluble nickel compounds and increased risk of respiratory cancers. However, the nature of this association is unclear because of limitations of the exposure data, inconsistent results across cohorts, and the presence of mixed exposures to water-insoluble nickel compounds and other confounders that are known or suspected carcinogens. Moreover, well-conducted animal inhalation studies, where exposures were solely to soluble nickel, failed to demonstrate a carcinogenic potential. Similar negative results were seen in animal oral studies. A model exists that relates respiratory carcinogenic potential to the bioavailability of nickel ion at nuclear sites within respiratory target cells. This model helps reconcile human, animal, and mechanistic data for soluble nickel compounds. For inhalation exposures, the predicted lack of bioavailability of nickel ion at target sites suggests that water-soluble nickel compounds, by themselves, will not be complete human carcinogens. However, if inhaled at concentrations high enough to induce chronic lung inflammation, these compounds may enhance carcinogenic risks associated with inhalation exposure to other substances. Overall, the weight of evidence indicates that inhalation exposure to soluble nickel alone will not cause cancer; moreover, if exposures are kept below levels that cause chronic respiratory toxicity, any possible tumor-enhancing effects (particularly in smokers) would be avoided.

  1. Bioavailability of nickel in man: effects of foods and chemically-defined dietary constituents on the absorption of inorganic nickel.

    Science.gov (United States)

    Solomons, N W; Viteri, F; Shuler, T R; Nielsen, F H

    1982-01-01

    By serial determination of the change in plasma nickel concentration following a standard dose of 22.4 mg of nickel sulfate hexahydrate containing 5 mg of elemental nickel, the bioavailability of nickel was estimated in human subjects. Plasma nickel concentration was stable in the fasting state and after an unlabeled test meal, but after the standard dose of nickel in water was elevated 48.8, 73.0, 80.0, and 53.3 microgram/1, respectively, at hours 1, 2, 3, and 4. Plasma nickel did not rise above fasting levels when 5 mg of nickel was added to two standard meals: a typical Guatemalan meal and a North American breakfast. When 5 mg of nickel was added to five beverages-whole cow milk, coffee, tea, orange juice, and Coca Cola-the rise in plasma nickel was significantly suppressed with all but Coca Cola. Response to nickel also was suppressed in the presence of 1 g of ascorbic acid. Phytic acid in a 2:1 molar ratio with nickel, however, did not affect the rise in plasma nickel. The chelate of iron and ethylenediaminetetraacetate, NaFeEDTA, an iron-fortifying agent suggested for application in Central America, slightly but not significantly depressed plasma nickel rise at 2 hours, whereas disodium EDTA depressed plasma nickel levels significantly below the fasting nickel curve at 3 and 4 hours postdose. These studies suggest that the differential responses of inorganic nickel to distinct foods, beverages, and chemically-defined dietary constituents could be important to human nutrition.

  2. Plutonium, americium, and uranium concentrations in Nevada Test Site soil profiles

    International Nuclear Information System (INIS)

    Essington, E.H.; Gilbert, R.O.; Eberhardt, L.L.; Fowler, E.B.

    1975-01-01

    Many soil profile samples were collected by the Nevada Applied Ecology Group from five nuclear safety test sites on the Nevada Test Site and Tonopah Test Range in Nevada, U.S.A. The profile samples were analyzed for 239 Pu, 240 Pu, 241 Am, and in some cases 235 U and 238 U, in order to estimate the depth of radionuclide penetration and level of contamination at specific sampling depths after an extended period of time since deposition on the surface. Nearly 70 individual profiles were examined. About one-half of the profiles exhibited a smooth leaching pattern with more than 95 percent of the plutonium in the top 5 cm. Other profile patterns are discussed relative to mechanical disturbance of the profile after the initial deposition, accumulation of plutonium in specific zones within the soil profile, and occurrence of large amounts of plutonium in the deepest parts of the soil profile. The implications of these observations are discussed with respect to redistribution of radioactivity by wind, water, and burrowing animals, ingestion by burrowing and grazing animals, uptake by vegetation, and cleanup operations. (auth)

  3. Human exposure to nickel

    Energy Technology Data Exchange (ETDEWEB)

    Grandjean, P

    1984-01-01

    In order of abundance in the earth's crust, nickel ranks as the 24th element and has been detected in different media in all parts of the biosphere. Thus, humans are constantly exposed to this ubiquitous element, though in variable amounts. Occupational exposures may lead to the retention of 100 micrograms of nickel per day. Environmental nickel levels depend particularly on natural sources, pollution from nickel-manufacturing industries and airborne particles from combustion of fossil fuels. Absorption from atmospheric nickel pollution is of minor concern. Vegetables usually contain more nickel than do other food items. Certain products, such as baking powder and cocoa powder, have been found to contain excessive amounts of nickel, perhaps related to nickel leaching during the manufacturing process. Soft drinking-water and acid beverages may dissolve nickel from pipes and containers. Scattered studies indicate a highly variable dietary intake of nickel, but most averages are about 200-300 micrograms/day. In addition, skin contact to a multitude of metal objects may be of significance to the large number of individuals suffering from contact dermatitis and nickel allergy. Finally, nickel alloys are often used in nails and prostheses for orthopaedic surgery, and various sources may contaminate intravenous fluids. Thus, human nickel exposure originates from a variety of sources and is highly variable. Occupational nickel exposure is of major significance, and leaching of nickel may add to dietary intakes and to cutaneous exposures. 79 references.

  4. Quantitative evaluation of polymer concentration profile during swelling of hydrophilic matrix tablets using 1H NMR and MRI methods.

    Science.gov (United States)

    Baumgartner, Sasa; Lahajnar, Gojmir; Sepe, Ana; Kristl, Julijana

    2005-02-01

    Many pharmaceutical tablets are based on hydrophilic polymers, which, after exposure to water, form a gel layer around the tablet that limits the dissolution and diffusion of the drug and provides a mechanism for controlled drug release. Our aim was to determine the thickness of the swollen gel layer of matrix tablets and to develop a method for calculating the polymer concentration profile across the gel layer. MR imaging has been used to investigate the in situ swelling behaviour of cellulose ether matrix tablets and NMR spectroscopy experiments were performed on homogeneous hydrogels with known polymer concentration. The MRI results show that the thickest gel layer was observed for hydroxyethylcellulose tablets, followed by definitely thinner but almost equal gel layer for hydroxypropylcellulose and hydroxypropylmethylcellulose of both molecular weights. The water proton NMR relaxation parameters were combined with the MRI data to obtain a quantitative description of the swelling process on the basis of the concentrations and mobilities of water and polymer as functions of time and distance. The different concentration profiles observed after the same swelling time are the consequence of the different polymer characteristics. The procedure developed here could be used as a general method for calculating polymer concentration profiles on other similar polymeric systems.

  5. Characterization and Growth Mechanism of Nickel Nano wires Resulting from Reduction of Nickel Formate in Polyol Medium

    International Nuclear Information System (INIS)

    Logutenko, O.A.; Titkov, A.I.; Vorobyov, A.M.; Yukhin, Y.M.; Lyakhov, N.Z.

    2016-01-01

    Nickel linear nano structures were synthesized by reduction of nickel formate with hydrazine hydrate in ethylene glycol medium in the absence of any surfactants or capping agents for direction of the particles growth. The effect of the synthesis conditions such as temperature, reduction time, type of polyol, and nickel formate concentration on the reduction products was studied. The size and morphology of the nickel nano wires were characterized by X-ray diffraction, scanning, and transmission electron microscopy. It was shown that the nickel nano crystallites were wire-shaped with a face-center-cubic phase. Ethylene glycol was found to play a crucial role in the formation of the nickel nano wires. The possible growth processes of the wire-shaped particles taking place at 110 and 130 degree are discussed. It was shown that, under certain synthesis conditions, nickel nano wires grow on the surface of the crystals of the solid intermediate of nickel with hydrazine hydrate.

  6. Exposure of nickel and the relevance of nickel sensitivity among hospital cleaners

    Energy Technology Data Exchange (ETDEWEB)

    Clemmensen, O J; Menne, T; Kaaber, K; Solgaard, P

    1981-01-01

    The nickel content of water specimens from consecutive stages during the cleaning process in a Danish hospital was analyzed. Statistically significant increases of the nickel concentrations were found from step to step of the cleaning, eventually exceeding the theoretical sensitizing safety limit. The relevance of the findings in relation to hand eczema is discussed.

  7. Oxygen 18 concentration profile measurements near the surface by 18O(p,α)15N resonance reaction

    International Nuclear Information System (INIS)

    Amsel, G.; David, D.

    1975-01-01

    The method of spectrum reduction in nuclear reaction microanalysis does not allow to obtain depth resolutions better than the order of 2000A. Resolutions of the order of 200A may be obtained by using the narrow resonance technique, when applied to thin films. The latter technique was extended to thick targets, with deep concentration profiles presenting a sharp gradient near the surface. This method is presented and illustrated by the study of 18 O profiles in oxygen diffusion measurements in growing ZrO 2 , using the 629keV resonance of the reaction 18 O(p,α) 15 N [fr

  8. NICKEL PLATING PROCESS

    Science.gov (United States)

    Hoover, T.B.; Zava, T.E.

    1959-05-12

    A simplified process is presented for plating nickel by the vapor decomposition of nickel carbonyl. In a preferred form of the invention a solid surface is nickel plated by subjecting the surface to contact with a mixture containing by volume approximately 20% nickel carbonyl vapor, 2% hydrogen sulfide and .l% water vapor or 1% oxygen and the remainder carbon dioxide at room temperature until the desired thickness of nickel is obtained. The advantage of this composition over others is that the normally explosive nickel carbonyl is greatly stabilized.

  9. Intermixing in heteroepitaxial islands: fast, self-consistent calculation of the concentration profile minimizing the elastic energy

    International Nuclear Information System (INIS)

    Gatti, R; UhlIk, F; Montalenti, F

    2008-01-01

    We present a novel computational method for finding the concentration profile which minimizes the elastic energy stored in heteroepitaxial islands. Based on a suitable combination of continuum elasticity theory and configurational Monte Carlo, we show that such profiles can be readily found by a simple, yet fully self-consistent, iterative procedure. We apply the method to SiGe/Si islands, considering realistic three-dimensional shapes (pyramids, domes and barns), finding strongly non-uniform distributions of Si and Ge atoms, in qualitative agreement with several experiments. Moreover, our simulated selective-etching profiles display, in some cases, a remarkable resemblance to the experimental ones, opening intriguing questions on the interplay between kinetic, entropic and elastic effects

  10. Vertical profiles of aerosol mass concentration derived by unmanned airborne in situ and remote sensing instruments during dust events

    Science.gov (United States)

    Mamali, Dimitra; Marinou, Eleni; Sciare, Jean; Pikridas, Michael; Kokkalis, Panagiotis; Kottas, Michael; Binietoglou, Ioannis; Tsekeri, Alexandra; Keleshis, Christos; Engelmann, Ronny; Baars, Holger; Ansmann, Albert; Amiridis, Vassilis; Russchenberg, Herman; Biskos, George

    2018-05-01

    In situ measurements using unmanned aerial vehicles (UAVs) and remote sensing observations can independently provide dense vertically resolved measurements of atmospheric aerosols, information which is strongly required in climate models. In both cases, inverting the recorded signals to useful information requires assumptions and constraints, and this can make the comparison of the results difficult. Here we compare, for the first time, vertical profiles of the aerosol mass concentration derived from light detection and ranging (lidar) observations and in situ measurements using an optical particle counter on board a UAV during moderate and weak Saharan dust episodes. Agreement between the two measurement methods was within experimental uncertainty for the coarse mode (i.e. particles having radii > 0.5 µm), where the properties of dust particles can be assumed with good accuracy. This result proves that the two techniques can be used interchangeably for determining the vertical profiles of aerosol concentrations, bringing them a step closer towards their systematic exploitation in climate models.

  11. Mg concentration profile and its control in the low temperature grown Mg-doped GaN epilayer

    Science.gov (United States)

    Liu, S. T.; Yang, J.; Zhao, D. G.; Jiang, D. S.; Liang, F.; Chen, P.; Zhu, J. J.; Liu, Z. S.; Liu, W.; Xing, Y.; Zhang, L. Q.; Wang, W. J.; Li, M.; Zhang, Y. T.; Du, G. T.

    2018-01-01

    In this work, the Cp2Mg flux and growth pressure influence to Mg doping concentration and depth profiles is studied. From the SIMS measurement we found that a transition layer exists at the bottom region of the layer in which the Mg doping concentration changes gradually. The thickness of transition layer decreases with the increases of Mg doping concentration. Through analysis, we found that this is caused by Ga memory effect which the Ga atoms stay residual in MOCVD system will react with Mg source, leading a transition layer formation and improve the growth rate. And the Ga memory effect can be well suppressed by increasing Mg doping concentration and growth pressure and thus get a steep Mg doping at the bottom region of p type layer.

  12. An augmented space recursive method for the first principles study of concentration profiles at CuNi alloy surfaces

    International Nuclear Information System (INIS)

    Dasgupta, I.; Mookerjee, A.

    1995-07-01

    We present here a first principle method for the calculation of effective cluster interactions for semi-infinite solid alloys required for the study of surface segregation and surface ordering on disordered surfaces. Our method is based on the augmented space recursion coupled with the orbital peeling method of Burke in the framework of the TB-LMTO. Our study of surface segregation in CuNi alloys demonstrates strong copper segregation and a monotonic concentration profile throughout the concentration range. (author). 35 refs, 4 figs, 2 tabs

  13. Artificial neural networks to evaluate the boron concentration decreasing profile in Blood-BPA samples of BNCT patients

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Reiriz, Alejandro, E-mail: garciareiriz@gmail.com [Department of Analytical Chemistry, Faculty of Biochemical and Pharmaceutical Sciences, National University of Rosario, Rosario Institute of Chemistry (IQUIR-CONICET), Suipacha 531, Rosario S2002LRK (Argentina); Magallanes, Jorge [Comision Nacional de Energia Atomica, Av. Gral. Paz 1499, San Martin, B1650KNA, Buenos Aires (Argentina); Zupan, Jure [National Institute of Chemistry, Hajdrihova 19, SLO-1000 Ljubljana, Eslovenia (Slovenia); Liberman, Sara [Comision Nacional de Energia Atomica, Av. Gral. Paz 1499, San Martin, B1650KNA, Buenos Aires (Argentina)

    2011-12-15

    For the prediction of decay concentration profiles of the p-boronophenylalanine (BPA) in blood during BNCT treatment, a method is suggested based on Kohonen neural networks. The results of a model trained with the concentration profiles from the literature are described. The prediction of the model was validated by the leave-one-out method. Its robustness shows that it is mostly independent on small variations. The ability to fit retrospective experimental data shows an uncertainty lower than the two compartment model used previously. - Highlights: Black-Right-Pointing-Pointer We predicted decaying concentration profiles of BPA in blood during BNCT therapy. Black-Right-Pointing-Pointer Is suggested a method based on Kohonen neural networks. Black-Right-Pointing-Pointer The results show that it is very robust and mostly independent of small variations. Black-Right-Pointing-Pointer It has a better ability to fit retrospective experimental data. Black-Right-Pointing-Pointer The model could be progressively improved by adding new data to the training matrix.

  14. Effect of abnormal outflow from end stages on concentration profile in uranium-stripping bank of PUREX flowsheet

    International Nuclear Information System (INIS)

    Ueda, Yoshinori; Matsumoto, Shiro

    2002-01-01

    The effect of the abnormal outflow from the end stages on the concentration profile was studied for the uranium-stripping bank to consider the design and the operation of the solvent extraction process, which eases the undesirable effects due to such abnormal flow. The abnormal outflow affected the concentration profile in the same manner as the decrease in the rate of the corresponding liquid flow rate entering the bank. The results suggested that the solvent extractor at the aqueous inlet stage in stripping banks and the solvent extractor at the organic inlet stage in extraction banks should be carefully designed to restrict the respective abnormal aqueous and organic outflows within the normal operational liquid flow rate range. Combining the result and the inherent phase separation behavior of the extractor suggested the possibility of designing the process with the self-controlled function of throughput, which eases the change of the concentration profile due to the undesirable increase in the rate of liquid flow rate entering the bank. Basically the proposed approaches are probably applicable to other general extraction and stripping processes. (author)

  15. Environmental and human toxicology of nickel - a review; Umwelt- und Humantoxikologie von Nickel - eine aktuelle Uebersicht

    Energy Technology Data Exchange (ETDEWEB)

    Beyersmann, D. [Fachbereich Biologie und Chemie, Univ. Bremen (Germany)

    2006-07-01

    Nickel is a relatively rare element, and its concentrations in ambient air, soils and waters are very low. Higher burdens of nickel are found in nickel industries and their proximity. The human uptake of nickel from the ambient air is neglectably low, except in industrial exposures. The main fraction of human nickel uptake is from food, nearly 50% stems from vegetables. Only about 2% of the oral uptake of nickel are resorbed and distributed over all organs investigated. The uptake of nickel compounds through the skin generally is very low. However, chronic skin contact with nickel and nickel compounds causes a specific contact allergy. This disease was observed after occupational exposure but also frequently in the general population. The number of new cases has dropped considerably due to reinforced prevention. Epidemiological studies with workers of nickel smelting and refining plants have demonstrated increased risks of nose and lung cancer. Human data are supported by results from animal experiments which have shown that inhalation of various nickel compounds caused lung cancer. Furthermore, animal experiments have yielded evidence that oral and inhalative exposure to nickel compounds impair reproduction. National and international agencies have classified various nickel compounds as carcinogenic to humans. The unit cancer risk attributed to life-long inhalation of 1 {mu}g Ni/m{sup 3} air is estimated to be between 2 x 10{sup -4} and 7 x 10{sup -4}. Occupational exposure limits in Germany have been the Technical Guidance Values of 0.5 mg/m{sup 3} for nickel and weakly soluble nickel compounds and of 0.05 mg/m{sup 3} for inhalable droplets of soluble nickel salts. The German limit value for ambient immission is 0.015 mg Ni/m{sup 2}. d, and for emission 0,5 mg Ni/m{sup 3}. Limit values for nickel in air are to be taken not as safe thresholds but as guidance values for the delimitation of the cancer risk. (orig.)

  16. Control of Sewer systems and Wastewater treatment plants using pollutant concentration profiles

    DEFF Research Database (Denmark)

    Bechmann, Henrik; Nielsen, Marinus K.; Madsen, Henrik

    1998-01-01

    On-line measurements of pollutants in the wastewater combined with grey-box modelling are used to estimate the amount of deposits in the sewer system. The pollutant mass flow at the wastewater treatment plant is found to consist of a diurnal profile minus the deposited amount of pollutants...

  17. Average pollutant concentration in soil profile simulated with Convective-Dispersive Equation. Model and Manual

    Science.gov (United States)

    Different parts of soil solution move with different velocities, and therefore chemicals are leached gradually from soil with infiltrating water. Solute dispersivity is the soil parameter characterizing this phenomenon. To characterize the dispersivity of soil profile at field scale, it is desirable...

  18. Analysis of the co-deposition of Al2O3 particles with nickel by an electrolytic route: The influence of organic additives presence and Al2O3 concentration

    Science.gov (United States)

    Temam, H. B.; Temam, E. G.

    2016-04-01

    Alloy coatings were prepared by co-deposition of Al2O3 particles in Ni matrix on carbon steel substrate from nickel chloride bath in which metallic powders were held in suspension. The influence of metal powder amount in the bath on chemical composition, morphology, thickness, microhardness and corrosion behavior of obtained coatings, has been investigated. It was shown that the presence of Al2O3 particles in deposit greatly improves the hardness and the wear resistance of alloy coatings. Characterization by microanalysis (EDX) of the various deposits elaborated confirms that the rate of particles incorporated increases as the concentration of solid particles increasing. The results showed that the presence of organic additives in Ni-Al2O3 electrolyte deposition led to an increase in the hardness and corrosion resistance of the deposits.

  19. Measured and modelled concentrations and vertical profiles of airborne particulate matter within the boundary layer of a street canyon

    International Nuclear Information System (INIS)

    Colls, J.J.; Micallef, A.

    1999-01-01

    Concentrations and vertical profiles of various fractions of airborne particulate matter (suspended particulate matter (SPM), PM 10 and PM 2.5 ) have been measured over the first three metres from ground in a street canyon. Measurements were carried out using automated near real-time apparatus called the Kinetic Sequential Sampling (KSS) system. KSS system is essentially an electronically-controlled lift carrying a real-time particle monitor for sampling air sequentially, at different heights within the breathing zone, which includes all heights within the surface layer of a street canyon at which people may breathe. Data is automatically logged at the different receptor levels, for the determination of the average vertical concentration profile of airborne particulate matter. For measuring the airborne particle concentration, a Grimm Dust Monitor 1.104/5 was used. The recorded data also allows for time series analysis of airborne particulate matter concentration at different heights. Time series data and hourly-average vertical concentration profiles in the boundary layer of the confines of a street are thought to be mainly determined by traffic emissions and traffic associated processes. Hence the measured data were compared with results of a street canyon emission-dispersion model in time and space. This Street Level Air Quality (SLAQ) model employs the plume-box technique and includes modules for simulating vehicle-generated effects such as thermally- and mechanically-generated turbulence and resuspension of road dust. Environmental processes, such as turbulence resulting from surface sensible heat and the formation of sulphate aerosol from sulphur dioxide exhaust emissions, are taken into account. The paper presents an outline description of the measuring technique and model used, and a comparison of the measured and modelled data

  20. Profiles

    International Nuclear Information System (INIS)

    2004-01-01

    Profiles is a synthetic overview of more than 100 national energy markets in the world, providing insightful facts and key energy statistics. A Profile is structured around 6 main items and completed by key statistics: Ministries, public agencies, energy policy are concerned; main companies in the oil, gas, electricity and coal sectors, status, shareholders; reserve, production, imports and exports, electricity and refining capacities; deregulation of prices, subsidies, taxes; consumption trends by sector, energy market shares; main energy projects, production and consumption prospects. Statistical Profiles are present in about 3 pages the main data and indicators on oil, gas, coal and electricity. (A.L.B.)

  1. Effects of age, adipose percent, and reproduction on PCB concentrations and profiles in an extreme fasting North Pacific marine mammal.

    Directory of Open Access Journals (Sweden)

    Sarah H Peterson

    Full Text Available Persistent organic pollutants, including polychlorinated biphenyls (PCBs, are widely distributed and detectable far from anthropogenic sources. Northern elephant seals (Mirounga angustirostris biannually travel thousands of kilometers to forage in coastal and open-ocean regions of the northeast Pacific Ocean and then return to land where they fast while breeding and molting. Our study examined potential effects of age, adipose percent, and the difference between the breeding and molting fasts on PCB concentrations and congener profiles in blubber and serum of northern elephant seal females. Between 2005 and 2007, we sampled blubber and blood from 58 seals before and after a foraging trip, which were then analyzed for PCBs. Age did not significantly affect total PCB concentrations; however, the proportion of PCB congeners with different numbers of chlorine atoms was significantly affected by age, especially in the outer blubber. Younger adult females had a significantly greater proportion of low-chlorinated PCBs (tri-, tetra-, and penta-CBs than older females, with the opposite trend observed for hepta-CBs, indicating that an age-associated process such as parity (birth may significantly affect congener profiles. The percent of adipose tissue had a significant relationship with inner blubber PCB concentrations, with the highest mean concentrations observed at the end of the molting fast. These results highlight the importance of sampling across the entire blubber layer when assessing contaminant levels in phocid seals and taking into account the adipose stores and reproductive status of an animal when conducting contaminant research.

  2. Process for forming a nickel foil with controlled and predetermined permeability to hydrogen

    Science.gov (United States)

    Engelhaupt, Darell E.

    1981-09-22

    The present invention provides a novel process for forming a nickel foil having a controlled and predetermined hydrogen permeability. This process includes the steps of passing a nickel plating bath through a suitable cation exchange resin to provide a purified nickel plating bath free of copper and gold cations, immersing a nickel anode and a suitable cathode in the purified nickel plating bath containing a selected concentration of an organic sulfonic acid such as a napthalene-trisulfonic acid, electrodepositing a nickel layer having the thickness of a foil onto the cathode, and separating the nickel layer from the cathode to provide a nickel foil. The anode is a readily-corrodible nickel anode. The present invention also provides a novel nickel foil having a greater hydrogen permeability than palladium at room temperature.

  3. Process for forming a nickel foil with controlled and predetermined permeability to hydrogen

    International Nuclear Information System (INIS)

    Engelhaupt, D. E.

    1981-01-01

    The present invention provides a novel process for forming a nickel foil having a controlled and predetermined hydrogen permeability. This process includes the steps of passing a nickel plating bath through a suitable cation exchange resin to provide a purified nickel plating bath free of copper and gold cations, immersing a nickel anode and a suitable cathode in the purified nickel plating bath containing a selected concentration of an organic sulfonic acid such as a napthalene-trisulfonic acid, electrodepositing a nickel layer having the thickness of a foil onto the cathode, and separating the nickel layer from the cathode to provide a nickel foil. The anode is a readilycorrodible nickel anode. The present invention also provides a novel nickel foil having a greater hydrogen permeability than palladium at room temperature

  4. Measurements of CO2 Concentration and Wind Profiles with A Scanning 1.6μm DIAL

    Science.gov (United States)

    Abo, M.; Shibata, Y.; Nagasawa, C.; Nagai, T.; Sakai, T.; Tsukamoto, M.

    2012-12-01

    Horizontal carbon dioxide (CO2) distribution and wind profiles are important information for understanding of the regional sink and source of CO2. The differential absorption lidar (DIAL) and the Doppler lidar with the range resolution is expected to bring several advantages over passive measurements. We have developed a new scanning 1.6μm DIAL and incoherent Doppler lidar system to perform simultaniously measurements of CO2 concentration and wind speed profiles in the atmosphere. The 1.6μm DIAL and Doppler lidar system consists of the Optical Parametric Generator (OPG) transmitter that excited by the LD pumped Nd:YAG laser with high repetition rate (500 Hz). The receiving optics include the near-infrared photomultiplier tube with high quantum efficiency operating at the photon counting mode, a fiber Bragg grating (FBG) filter to detct Doppler shift, and a 25 cm telescope[1][2]. Laser beam is transmitted coaxially and motorized scanning mirror system can scan the laser beam and field of view 0-360deg horizontally and 0-52deg vertically. We report the results of vertical CO2 scanning measurenents and vertical wind profiles. The scanning elevation angles were from 12deg to 24deg with angular step of 4deg and CO2 concentration profiles were obtained up to 1 km altitude with 200 m altitude resolution. We also obtained vertical wind vector profiles by measuring line-of-sight wind profiles at two azimuth angles with a fixed elevation angle 52deg. Vertical wind vector profiles were obtained up to 5 km altitude with 1 km altitude rasolution. This work was financially supported by the System Development Program for Advanced Measurement and Analysis of the Japan Science and Technology Agency. References [1] L. B. Vann, et al., "Narrowband fiber-optic phase-shifted Fabry-Perot Bragg grating filters for atmospheric water vapor lidar measurements", Appl. Opt., 44, pp. 7371-7377 (2005). [2] Y. Shibata, et al., "1.5μm incoherent Doppler lidar using a FBG filter", Proceedings

  5. Measurement of concentration profile during charging of Li battery anode materials in LiClO4-PC electrolyte

    International Nuclear Information System (INIS)

    Nishikawa, K.; Fukunaka, Y.; Sakka, T.; Ogata, Y.H.; Selman, J.R.

    2007-01-01

    Li metal was galvanostatically electrodeposited on a horizontally positioned, downward-facing Li metal cathode in 0.5 M LiClO 4 -PC electrolyte. The refractive index profile corresponding to the transient Li + ion concentration profile formed in the electrolyte solution upon applying a current step was measured in-situ by holographic interferometry. The configuration of the electrolytic cell was such that mass transfer was governed only by transient diffusion and migration, in the absence of convection. Between the moment of closing the current circuit and the time at which the interference fringes started to shift, an incubation period was observed. Such an incubation period had earlier been observed in lithium electrodeposition at a vertical planar Li metal cathode. The incubation period for the horizontal Li cathode was roughly half that for a vertical one. To study the effect of the electrode material on the incubation period, interferometry measurements were also made at an electrodeposited Ni-Sn alloy electrode. The concentration profile formed near the Ni-Sn alloy electrode during lithiation (alloying or intercalation of Li + into the electrode) agrees well with predictions made by means of the one-dimensional diffusion equation. Only very short incubation period was detected, but the magnitude was negligibly smaller than that of Li metal electrodeposition. The incubation period therefore appears to be characteristic for Li metal electrode only

  6. Absorption and retention of nickel from drinking water in relation to food intake and nickel sensitivity.

    Science.gov (United States)

    Nielsen, G D; Søderberg, U; Jørgensen, P J; Templeton, D M; Rasmussen, S N; Andersen, K E; Grandjean, P

    1999-01-01

    Two studies were performed to examine the influence of fasting and food intake on the absorption and retention of nickel added to drinking water and to determine if nickel sensitization played any role in this regard. First, eight nonallergic male volunteers fasted overnight before being given nickel in drinking water (12 micrograms Ni/kg) and, at different time intervals, standardized 1400-kJ portions of scrambled eggs. When nickel was ingested in water 30 min or 1 h prior to the meal, peak nickel concentrations in serum occurred 1 h after the water intake, and the peak was 13-fold higher than the one seen 1 h after simultaneous intake of nickel-containing water and scrambled eggs. In the latter case, a smaller, delayed peak occurred 3 h after the meal. Median urinary nickel excretion half-times varied between 19.9 and 26.7 h. Within 3 days, the amount of nickel excreted corresponded to 2.5% of the nickel ingested when it was mixed into the scrambled eggs. Increasing amounts were excreted as the interval between the water and the meal increased, with 25.8% of the administered dose being excreted when the eggs were served 4 h prior to the nickel-containing drinking water. In the second experiment, a stable nickel isotope, 61Ni, was given in drinking water to 20 nickel-sensitized women and 20 age-matched controls, both groups having vesicular hand eczema of the pompholyx type. Nine of 20 nickel allergic eczema patients experienced aggravation of hand eczema after nickel administration, and three also developed a maculopapular exanthema. No exacerbation was seen in the control group. The course of nickel absorption and excretion in the allergic groups did not differ and was similar to the pattern seen in the first study, although the absorption in the women was less. A sex-related difference in gastric emptying rates may play a role. Thus, food intake and gastric emptying are of substantial significance for the bioavailability of nickel from aqueous solutions

  7. Profile of isokinetic eccentric-to-concentric strength ratios of shoulder rotator muscles in elite female team handball players.

    Science.gov (United States)

    Andrade, Marilia Dos Santos; Fleury, Anna Maria; de Lira, Claudio Andre Barbosia; Dubas, Joao Paulo; da Silva, Antonio Carlos

    2010-05-01

    The purpose of this study was to establish the isokinetic profile of shoulder rotator muscles strength in female handball players. Twenty-seven handball players performed concentric and eccentric strength tests of both dominant and non-dominant upper limbs on an isokinetic dynamometer. Internal and external rotator muscles peak torque was assessed at 1.05, 3.14, and 5.23 rad . s(-1) in concentric mode and at 3.14 and 5.23 rad . s(-1) in eccentric mode. Concentric balance ratio and functional ratio were obtained. Bi-lateral deficiency was compared. Concentric strength for internal and external rotation was significantly greater for the dominant than for the non-dominant limb for all speeds (P muscles were stronger in the dominant than the non-dominant limb (P stronger than the non-dominant side, balance concentric ratios remained the same, with only the functional strength ratio different at 5.23 rad . s(-1). Our results suggest that concentric strength exercises be used for internal and external rotators on the non-dominant side, and functional exercise that improves eccentric rotation strength for prevention programmes.

  8. Linseed oil supplemented concentrate fed to Brahman crossbred fattening steers on carcass quality traits and intramuscular fatty acid profiles

    Directory of Open Access Journals (Sweden)

    Pitunart Noosen

    2017-02-01

    Full Text Available The objective of this study was to determine the linseed oil supplemented concentrate fed to Brahman crossbred fattening steers on carcass quality trait and intramuscular fatty acid (FA profiles. All steers were fed 14% CP concentrate. The treatments included: (1 7 kg/d concentrate; (2 4 kg/d concentrate supplemented with 200 g/d palm oil (PO; (3 4 kg/d concentrate supplemented with 100 g/d PO and 100 g/d linseed oil (LSO; and (4 4 kg/d concentrate supplemented with 200 g/d LSO. The animals in the treatment 1 were fed ad libitum rice straw (RS, whereas the animals in other treatments were fed ad libitum fresh grass (FG. Dietary treatments had no effect on nutrient intake while oil supplement decreased dry matter intake (DMI. Inclusion of LSO did not negatively affect carcass quality, but increasing amount of LSO supplement increased the n-3 fatty acids and lowered the n-6/n-3 ratio in beef

  9. Protective effects of zinc acetate toward the toxicity of nickelous acetate in rats

    International Nuclear Information System (INIS)

    Waalkes, M.P.; Kasprzak, K.S.; Ohshima, M.; Poirier, L.A.

    1985-01-01

    This study was designed to determine the effects of zinc pretreatment on the acute toxicity of nickel. Male Fischer rats received either nickel alone (i.p.), zinc alone (s.c.), zinc plus nickel, or saline (i.p. and s.c.; controls). Zinc pretreatment significantly increased the 14-day survival of nickel-related rats. Zinc did not, however, prevent the reduction in weight gain over 2 weeks seen with nickel treatment. Histopathologically, at 120 h following nickel exposure, kidneys in the group receiving nickel alone generally showed moderate nephropathy (multifocal proximal tubule degeneration with necrosis) while in the zinc plus nickel group the nephropathy was generally mild. Zinc pretreatment had no apparent effect on the pharmacokinetics of nickel over 24 h as assessed by urinary excretion, blood levels or organ distribution. Zinc pretreatment also did not alter the subcellular distribution of renal nickel 6 h after nickel exposure. Enhanced synthesis of metallothionein did not appear to play a critical role in the reduction of nickel toxicity, since renal concentrations of this metalbuilding protein, although elevated compared to control, were not different in rats receiving zinc and nickel or zinc alone. Zinc pretreatment did, however, have marked effect on nickel-induced hyperglycemia, reducing both the duration and severity of elevated blood glucose levels. Results of the study show that zinc can prevent some of the toxic effects of nickel and that the mechanism of this action does not appear to involve either metalothionein or alterations in the pharmacokinetics of nickel. (author)

  10. Tracking control of concentration profiles in a fed-batch bioreactor using a linear algebra methodology.

    Science.gov (United States)

    Rómoli, Santiago; Serrano, Mario Emanuel; Ortiz, Oscar Alberto; Vega, Jorge Rubén; Eduardo Scaglia, Gustavo Juan

    2015-07-01

    Based on a linear algebra approach, this paper aims at developing a novel control law able to track reference profiles that were previously-determined in the literature. A main advantage of the proposed strategy is that the control actions are obtained by solving a system of linear equations. The optimal controller parameters are selected through Monte Carlo Randomized Algorithm in order to minimize a proposed cost index. The controller performance is evaluated through several tests, and compared with other controller reported in the literature. Finally, a Monte Carlo Randomized Algorithm is conducted to assess the performance of the proposed controller. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

  11. Interdependent action of nickel sulphate and X-rays on human lymphoblastoid leukeamic cells

    International Nuclear Information System (INIS)

    Bensimon, Jacques

    1977-01-01

    In a first experiment, cells were cultured in media supplemented by nickel sulphate, irradiated in same media and cultured in same media after irradiation. In a second experiment, cells were cultured during 18hrs. in media supplemented by nickel sulphate, and then cells were washed and cultured in normal media where they were irradiated. The nickel sulphate toxicity appears as a creasing function of the nickel sulphate concentration and the nickel sulphate action endurance. The nickel sulphate toxic effect is amplified by X-rays. This amplification is a time function that depends on the X-ray dose, nickel sulphate concentration and period of time from the outset of culture to the irradiation. The nickel sulphate toxic effect appears faster when nickel works after X-rays [fr

  12. Polychlorinated biphenyl (PCB) contamination in Galveston Bay, Texas: Comparing concentrations and profiles in sediments, passive samplers, and fish.

    Science.gov (United States)

    Oziolor, Elias M; Apell, Jennifer N; Winfield, Zach C; Back, Jeffrey A; Usenko, Sascha; Matson, Cole W

    2018-05-01

    The industrialized portion of the Houston Ship Channel (HSC) is heavily contaminated with anthropogenic contaminants, most prominent of which are the polychlorinated biphenyls (PCBs). This contamination has driven adaptive evolution in a keystone species for Galveston Bay, the Gulf killifish (Fundulus grandis). We investigated the geographical extent of PCB impacts by sampling 12 sites, ranging from the heavily industrialized upper portion of the HSC to Galveston Island. At each site, PCB concentrations and profiles were determined in three environmental compartments: sediment, water (polyethylene passive samplers), and fish tissue (resident Gulf killifish). We observed a steep gradient of PCB contamination, ranging from 4.00 to 100,000 ng/g organic carbon in sediment, 290-110,000 ng/g lipid in fish, and 4.5-2300 ng/g polyethylene in passive samplers. The PCB congener profiles in Gulf killifish at the most heavily contaminated sites were shifted toward the higher chlorinated PCBs and were highly similar to the sediment contamination profiles. In addition, while magnitude of total PCB concentrations in sediment and total fish contamination levels were highly correlated between sites, the relative PCB congener profiles in fish and passive samplers were more alike. This strong correlation, along with a lack of dependency of biota-sediment accumulation factors with total contamination rates, confirm the likely non-migratory nature of Gulf killifish and suggest their contamination levels are a good site-specific indicator of contamination in the Galveston Bay area. The spatial gradient of PCB contamination in Galveston Bay was evident in all three matrices studied and was observed effectively using Gulf killifish contamination as an environmentally relevant bioindicator of localized contamination in this environment. Copyright © 2018 Elsevier Ltd. All rights reserved.

  13. Elastic recoil detection analysis for the determination of hydrogen concentration profiles in switchable mirrors

    NARCIS (Netherlands)

    Huisman, M.C.; van der Molen, S.J.; Vis, R.D.

    1999-01-01

    Switchable mirrors made of thin films of Y, La or rare-earth (RE) metals exhibit spectacular changes in their optical and electrical properties upon hydrogen loading. The study of these materials has indicated that the occurring phenomena are highly sensitive to the actual hydrogen concentration in

  14. A comparative performance study of a photovoltaic concentrator system with discrete mirror and continuos profile for two different absorber shapes

    Energy Technology Data Exchange (ETDEWEB)

    H, Saiful; Rezau, K.M [University of Dhaka, Dhaka (Bangladesh)

    2000-07-01

    Profiles of parabolic concentrators of discrete mirror and continuos surface mirror have been designed for combined electrical thermal photovoltaic systems. In the design the changes of concentration ratio, effect of reflection, angle of incidence over the absorber have been taken into account for maximum energy collection. The performances of the system are studied for solar cells of modified grid finger for illuminations from 1-10 sun. The local concentration ratio (LCR) distribution over the absorbers for both the concentrator, the optical efficiency, thermal efficiency, electrical and thermal power output and overall efficiency have been evaluated for different values of beam radiation concentration ratio and focal distance. [Spanish] Se han disenado perfiles de concentradores parabolicos de espejo discreto y de superficie continua para sistemas fotovoltaicos combinados electricos y termicos. En el diseno los cambios de la proporcion de concentracion, del efecto de la reflexion, del angulo de incidencia sobre el observador se han tenido en cuenta para una maxima recoleccion de energia. Los rendimientos del sistema se han estudiado para celdas solares de parrilla modificada para iluminaciones solares de 1-10. Han sido evaluados para diferentes valores de la proporcion de la concentracion de la radiacion en el rayo y la distancia focal la proporcion de concentracion local (LCR) de la distribucion en los absorbedores, para el concentrador la eficiencia optica, la eficiencia termica, electrica, la produccion de energia termica y electrica y la eficiencia total.

  15. Plutonium and americium concentrations and vertical profiles in some Italian mosses used as bioindicators

    International Nuclear Information System (INIS)

    Testa, C.; Desideri, D.; Meli, M.A.; Guerra, F.; Degetto, S.; Jia, G.; Gerdol, R.

    1998-01-01

    We have examined the uptake of actinide elements Am and Pu by different species of lichen and moss collected in two locations (Urbino, Central Italy; Alps region, North-east Italy). Plutonium and americium were separated and determined by extraction chromatography, electrodeposition and alpha-spectrometry. This paper summarizes our results with a special emphasis on the vertical profiles of these actinides in two different species of mosses. Several 1-2 cm depth sections were obtained and dated by 210 Pb method. A typical peak for 239,240 Pu and 241 Am was found in the very old moss species ('Sphagnum Compactum') at a depth corresponding to the period 1960-1970 which was the period characterized by the maximum nuclear weapon tests. In a younger moss species ('Neckeria Crispa') no peak was observed and the regression curves showed that Am is more mobile than 239,240 Pu and 238 Pu. (author)

  16. Tracer concentration profiles measured in central London as part of the REPARTEE campaign

    Directory of Open Access Journals (Sweden)

    D. Martin

    2011-01-01

    Full Text Available There have been relatively few tracer experiments carried out that have looked at vertical plume spread in urban areas. In this paper we present results from two tracer (cyclic perfluorocarbon experiments carried out in 2006 and 2007 in central London centred on the BT Tower as part of the REPARTEE (Regent's Park and Tower Environmental Experiment campaign. The height of the tower gives a unique opportunity to study vertical dispersion profiles and transport times in central London. Vertical gradients are contrasted with the relevant Pasquill stability classes. Estimation of lateral advection and vertical mixing times are made and compared with previous measurements. Data are then compared with a simple operational dispersion model and contrasted with data taken in central London as part of the DAPPLE campaign. This correlates dosage with non-dimensionalised distance from source. Such analyses illustrate the feasibility of the use of these empirical correlations over these prescribed distances in central London.

  17. Construction of Multi-Year Time-Series Profiles of Suspended Particulate Inorganic Matter Concentrations Using Machine Learning Approach

    Directory of Open Access Journals (Sweden)

    Pannimpullath R. Renosh

    2017-12-01

    Full Text Available Hydro-sedimentary numerical models have been widely employed to derive suspended particulate matter (SPM concentrations in coastal and estuarine waters. These hydro-sedimentary models are computationally and technically expensive in nature. Here we have used a computationally less-expensive, well-established methodology of self-organizing maps (SOMs along with a hidden Markov model (HMM to derive profiles of suspended particulate inorganic matter (SPIM. The concept of the proposed work is to benefit from all available data sets through the use of fusion methods and machine learning approaches that are able to process a growing amount of available data. This approach is applied to two different data sets entitled “Hidden” and “Observable”. The hidden data are composed of 15 months (27 September 2007 to 30 December 2008 of hourly SPIM profiles extracted from the Regional Ocean Modeling System (ROMS. The observable data include forcing parameter variables such as significant wave heights ( H s and H s 50 (50 days from the Wavewatch 3-HOMERE database and barotropic currents ( U b a r and V b a r from the Iberian–Biscay–Irish (IBI reanalysis data. These observable data integrate hourly surface samples from 1 February 2002 to 31 December 2012. The time-series profiles of the SPIM have been derived from four different stations in the English Channel by considering 15 months of output hidden data from the ROMS as a statistical representation of the ocean for ≈11 years. The derived SPIM profiles clearly show seasonal and tidal fluctuations in accordance with the parent numerical model output. The surface SPIM concentrations of the derived model have been validated with satellite remote sensing data. The time series of the modeled SPIM and satellite-derived SPIM show similar seasonal fluctuations. The ranges of concentrations for the four stations are also in good agreement with the corresponding satellite data. The high accuracy of the

  18. Effect of tetraethylthiuramdisulphide and diethyldithiocarbamate on nickel toxicokinetics in mice

    International Nuclear Information System (INIS)

    Dalsgaard, G.; Andersen, O.

    1994-01-01

    A new experimental pharmacokinetic model using the γ-emitting isotope 57 Ni for studying nickel toxicokinetics was employed in a recent investigation in order to quantitatively study, for the first time, the effect of tetraethylthiuram disulphide (disulfiram, Antabuse, TTD) and sodium diethyldithiocarbamate (DDC) on whole-body retention and organ distribution of nickel in mice. TTD or its decomposition product DDC given orally by stomach tube shortly after oral administration of a low dose of nickel chloride labelled with 57 Ni resulted in an approximately ten times higher whole-body retention of nickel compared to the retention in a control group exposed to nickel only. These chelators increased the whole-body retention of nickel also when given by intraperitoneal injection shortly after oral or intraperitoneal administration of nickel. Oral administration of a single dose of TTD or DDC rapidly after an oral dose of nickel chloride also resulted in extensive changes in the organ distribution of nickel, thus the nickel content in the brain was at least 700 times higher than in a control group given the same dose of nickel only. If DDC was given intraperitoneally after nickel given orally, the relative organ distribution of nickel to most organs was the same as if the chelator was given orally, though the contents of the liver and lungs were lower. That TTD and DDC resulted in a transport of nickel to the brain, is underlined by the fact that after 20 hr, approximately 15% and after 45-50 hr, 30% of the total body burden of Ni was found in the brain. Stating the nickel content as concentrations, we found after 19 hr to 23 hr the highest nickel concentration in the brain, kidneys, lungs and liver, in order of decreasing concentration. From 68 hr to 122 hr the order was brain, lungs, kidneys and liver. TTD and DDC are widely used clinically. These results indicate, that long-term simultaneous administration of nickel and TTD or DDC to humans should be avoided, as

  19. Concentrations of cadmium, Cobalt, Lead, Nickel, and Zinc in Blood and Fillets of Northern Hog Sucker (Hypentelium nigricans) from streams contaminated by lead-Zinc mining: Implications for monitoring

    Science.gov (United States)

    Schmitt, C.J.; Brumbaugh, W.G.; May, T.W.

    2009-01-01

    Lead (Pb) and other metals can accumulate in northern hog sucker (Hypentelium nigricans) and other suckers (Catostomidae), which are harvested in large numbers from Ozark streams by recreational fishers. Suckers are also important in the diets of piscivorous wildlife and fishes. Suckers from streams contaminated by historic Pb-zinc (Zn) mining in southeastern Missouri are presently identified in a consumption advisory because of Pb concentrations. We evaluated blood sampling as a potentially nonlethal alternative to fillet sampling for Pb and other metals in northern hog sucker. Scaled, skin-on, bone-in "fillet" and blood samples were obtained from northern hog suckers (n = 75) collected at nine sites representing a wide range of conditions relative to Pb-Zn mining in southeastern Missouri. All samples were analyzed for cadmium (Cd), cobalt (Co), Pb, nickel (Ni), and Zn. Fillets were also analyzed for calcium as an indicator of the amount of bone, skin, and mucus included in the samples. Pb, Cd, Co, and Ni concentrations were typically higher in blood than in fillets, but Zn concentrations were similar in both sample types. Concentrations of all metals except Zn were typically higher at sites located downstream from active and historic Pb-Zn mines and related facilities than at nonmining sites. Blood concentrations of Pb, Cd, and Co were highly correlated with corresponding fillet concentrations; log-log linear regressions between concentrations in the two sample types explained 94% of the variation for Pb, 73-83% of the variation for Co, and 61% of the variation for Cd. In contrast, relations for Ni and Zn explained Fillet Pb and calcium concentrations were correlated (r = 0.83), but only in the 12 fish from the most contaminated site; concentrations were not significantly correlated across all sites. Conversely, fillet Cd and calcium were correlated across the range of sites (r = 0.78), and the inclusion of calcium in the fillet-to-blood relation explained an

  20. Absorption and retention of nickel from drinking water in relation to food intake and nickel sensitivity

    DEFF Research Database (Denmark)

    Nielsen, G D; Søderberg, U; Jørgensen, Poul Jørgen

    1999-01-01

    nickel in drinking water (12 micrograms Ni/kg) and, at different time intervals, standardized 1400-kJ portions of scrambled eggs. When nickel was ingested in water 30 min or 1 h prior to the meal, peak nickel concentrations in serum occurred 1 h after the water intake, and the peak was 13-fold higher...... than the one seen 1 h after simultaneous intake of nickel-containing water and scrambled eggs. In the latter case, a smaller, delayed peak occurred 3 h after the meal. Median urinary nickel excretion half-times varied between 19.9 and 26.7 h. Within 3 days, the amount of nickel excreted corresponded...... to 2.5% of the nickel ingested when it was mixed into the scrambled eggs. Increasing amounts were excreted as the interval between the water and the meal increased, with 25.8% of the administered dose being excreted when the eggs were served 4 h prior to the nickel-containing drinking water...

  1. Soil erosion determination using the Cs-137 concentration in the soil profile, in a rain fall seasonal ecosystem of Mexico

    International Nuclear Information System (INIS)

    Martinez, L.R.; Garcia, O.F.; Mass, J.M.

    1992-01-01

    The soils erosion is one of the main processes of environmental degradation. Latin America presents high levels of erosion however the works that quantificate this problem are few. The application of methods agreed to the tropical countries conditions represents an important limitation in the developing of these works. A methodological option that has arisen in the last years is the application of the distribution analysis of Cs-137 concentration in the soil profile, for estimating the soil motion in a seasonal tropical ecosystem in Chamela, Jalisco, Mexico. The low concentrations of Cs-137 were determined with a gamma spectroscopy system of high resolution and low noise. It is confirmed that the redistribution of Cs-137 in the landscape depends on erosive processes. The conclusion is that in the interpretation of Cs-137 levels it is necessary to incorporate morphology analysis of declivity since this is a low scale measurement. (Author)

  2. An Excel®-based visualization tool of 2-D soil gas concentration profiles in petroleum vapor intrusion.

    Science.gov (United States)

    Verginelli, Iason; Yao, Yijun; Suuberg, Eric M

    2016-01-01

    In this study we present a petroleum vapor intrusion tool implemented in Microsoft ® Excel ® using Visual Basic for Applications (VBA) and integrated within a graphical interface. The latter helps users easily visualize two-dimensional soil gas concentration profiles and indoor concentrations as a function of site-specific conditions such as source strength and depth, biodegradation reaction rate constant, soil characteristics and building features. This tool is based on a two-dimensional explicit analytical model that combines steady-state diffusion-dominated vapor transport in a homogeneous soil with a piecewise first-order aerobic biodegradation model, in which rate is limited by oxygen availability. As recommended in the recently released United States Environmental Protection Agency's final Petroleum Vapor Intrusion guidance, a sensitivity analysis and a simplified Monte Carlo uncertainty analysis are also included in the spreadsheet.

  3. Dietary fish oil alters the lysophospholipid metabolomic profile and decreases urinary 11-dehydro thromboxane B₂ concentration in healthy Beagles.

    Science.gov (United States)

    Hall, Jean A; Brockman, Jeffrey A; Jewell, Dennis E

    2011-12-15

    Increased concentrations of dietary fish oil and antioxidants have been shown previously to change circulating concentrations of individual fatty acids (FAs) and vitamin E. The purpose of this study was to further investigate the effects of vitamins E and C, in combination with dietary fish oil, on selected blood and urinary biomarkers. Fifty adult Beagle dogs (mean age 5.3 years, range 1.4-14.2 years) were randomized into five dietary treatment groups for 90 days. All foods were complete and balanced and met the nutrient profiles of AAFCO for adult dogs. For 60 days before study initiation, dogs consumed a pretrial food that contained 74 IU/kg vitaminE and 0mg/kg vitaminC. The five experimental foods were confirmed by analytical methods to contain ≥ 640 IU/kg vitaminE and 130 mg/kg vitaminC (as fed). Experimental foods ranged from low levels of EPA and DHA (pretrial food and lowest experimental food had 0.01% EPA and no detectable DHA) to the highest experimental food with 0.25% EPA and 0.17% DHA. Serum was analyzed for FAs, vitamin E, and cholesterol concentrations; urine was analyzed for 11-dehydro thromboxane B(2) (TXB(2)). Serum was also used for metabolomic analysis. FA intake ranged from 0.02 g/day EPA and 0.02 g/day DHA to 0.58 g/day EPA and 0.39 g/day DHA. Increasing dietary concentrations of EPA and DHA resulted in increased serum concentrations of EPA and DHA in a dose-dependent fashion. Greater dietary vitamin E intake resulted in increased serum vitamin E concentrations (Pvitamin E concentrations (Pvitamin E concentration is enhanced primarily by feeding vitamin E and secondarily by serum cholesterol concentration. When feeding diets enriched with fish oil, the major negative predictor of urinary 11-dehydro TXB(2) concentration is serum EPA concentration. Plasma lysophospholipids can be dynamically regulated by dietary fish oil supplementation. Copyright © 2011 Elsevier B.V. All rights reserved.

  4. Screening of Trichoderma isolates for their potential of biosorption of nickel and cadmium.

    Science.gov (United States)

    Nongmaithem, Nabakishor; Roy, Ayon; Bhattacharya, Prateek Madhab

    2016-01-01

    Fourteen Trichoderma isolates were evaluated for their tolerance to two heavy metals, nickel and cadmium. Three isolates, MT-4, UBT-18, and IBT-I, showed high levels of nickel tolerance, whereas MT-4, UBT-18, and IBT-II showed better tolerance of cadmium than the other isolates. Under nickel stress, biomass production increased up to a Ni concentration of 60ppm in all strains but then decreased as the concentrations of nickel were further increased. Among the nickel-tolerant isolates, UBT-18 produced significantly higher biomass upon exposure to nickel (up to 150ppm); however, the minimum concentration of nickel required to inhibit 50% of growth (MIC50) was highest in IBT-I. Among the cadmium-tolerant isolates, IBT-II showed both maximum biomass production and a maximum MIC50 value in cadmium stress. As the biomass of the Trichoderma isolates increased, a higher percentage of nickel removal was observed up to a concentration of 40ppm, followed by an increase in residual nickel and a decrease in biomass production at higher nickel concentrations in the medium. The increase in cadmium concentrations resulted in a decrease in biomass production and positively correlated with an increase in residual cadmium in the culture broth. Nickel and cadmium stress also influenced the sensitivity of the Trichoderma isolates to soil fungistasis. Isolates IBT-I and UBT-18 were most tolerant to fungistasis under nickel and cadmium stress, respectively. Copyright © 2016 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

  5. Vertical profiles of lung deposited surface area concentration of particulate matter measured with a drone in a street canyon.

    Science.gov (United States)

    Kuuluvainen, Heino; Poikkimäki, Mikko; Järvinen, Anssi; Kuula, Joel; Irjala, Matti; Dal Maso, Miikka; Keskinen, Jorma; Timonen, Hilkka; Niemi, Jarkko V; Rönkkö, Topi

    2018-05-23

    The vertical profiles of lung deposited surface area (LDSA) concentration were measured in an urban street canyon in Helsinki, Finland, by using an unmanned aerial system (UAS) as a moving measurement platform. The street canyon can be classified as an avenue canyon with an aspect ratio of 0.45 and the UAS was a multirotor drone especially modified for emission measurements. In the experiments of this study, the drone was equipped with a small diffusion charge sensor capable of measuring the alveolar LDSA concentration of particles. The drone measurements were conducted during two days on the same spatial location at the kerbside of the street canyon by flying vertically from the ground level up to an altitude of 50 m clearly above the rooftop level (19 m) of the nearest buildings. The drone data were supported by simultaneous measurements and by a two-week period of measurements at nearby locations with various instruments. The results showed that the averaged LDSA concentrations decreased approximately from 60 μm 2 /cm 3 measured close to the ground level to 36-40 μm 2 /cm 3 measured close to the rooftop level of the street canyon, and further to 16-26 μm 2 /cm 3 measured at 50 m. The high-resolution measurement data enabled an accurate analysis of the functional form of vertical profiles both in the street canyon and above the rooftop level. In both of these regions, exponential fits were used and the parameters obtained from the fits were thoroughly compared to the values found in literature. The results of this study indicated that the role of turbulent mixing caused by traffic was emphasized compared to the street canyon vortex as a driving force of the dispersion. In addition, the vertical profiles above the rooftop level showed a similar exponential decay compared to the profiles measured inside the street canyon. Copyright © 2018 Elsevier Ltd. All rights reserved.

  6. Dynamic Analysis of the Temperature and the Concentration Profiles of an Industrial Rotary Kiln Used in Clinker Production

    Directory of Open Access Journals (Sweden)

    DIULIA C.Q. RODRIGUES

    Full Text Available ABSTRACT Cement is one of the most used building materials in the world. The process of cement production involves numerous and complex reactions that occur under different temperatures. Thus, there is great interest in the optimization of cement manufacturing. Clinker production is one of the main steps of cement production and it occurs inside the kiln. In this paper, the dry process of clinker production is analysed in a rotary kiln that operates in counter flow. The main phenomena involved in clinker production is as follows: free residual water evaporation of raw material, decomposition of magnesium carbonate, decarbonation, formation of C3A and C4AF, formation of dicalcium silicate, and formation of tricalcium silicate. The main objective of this study was to propose a mathematical model that realistically describes the temperature profile and the concentration of clinker components in a real rotary kiln. In addition, the influence of different speeds of inlet gas and solids in the system was analysed. The mathematical model is composed of partial differential equations. The model was implemented in Mathcad (available at CCA/UFES and solved using industrial input data. The proposal model is satisfactory to describe the temperature and concentration profiles of a real rotary kiln.

  7. Dynamic Analysis of the Temperature and the Concentration Profiles of an Industrial Rotary Kiln Used in Clinker Production.

    Science.gov (United States)

    Rodrigues, Diulia C Q; Soares, Atílio P; Costa, Esly F; Costa, Andréa O S

    2017-01-01

    Cement is one of the most used building materials in the world. The process of cement production involves numerous and complex reactions that occur under different temperatures. Thus, there is great interest in the optimization of cement manufacturing. Clinker production is one of the main steps of cement production and it occurs inside the kiln. In this paper, the dry process of clinker production is analysed in a rotary kiln that operates in counter flow. The main phenomena involved in clinker production is as follows: free residual water evaporation of raw material, decomposition of magnesium carbonate, decarbonation, formation of C3A and C4AF, formation of dicalcium silicate, and formation of tricalcium silicate. The main objective of this study was to propose a mathematical model that realistically describes the temperature profile and the concentration of clinker components in a real rotary kiln. In addition, the influence of different speeds of inlet gas and solids in the system was analysed. The mathematical model is composed of partial differential equations. The model was implemented in Mathcad (available at CCA/UFES) and solved using industrial input data. The proposal model is satisfactory to describe the temperature and concentration profiles of a real rotary kiln.

  8. Metabolic profiles and lipoprotein lipid concentrations in non-obese and obese patients with polycystic ovarian disease.

    Science.gov (United States)

    Mahabeer, S; Naidoo, C; Norman, R J; Jialal, I; Reddi, K; Joubert, S M

    1990-10-01

    Clinical parameters, androgen status and lipoprotein lipid profiles were assessed in 10 non-obese and 10 obese patients with polycystic ovarian disease (PCOD) and reference subjects matched for age, height and weight. Both obese and non-obese women with PCOD had significantly higher androgen levels when compared to the reference groups. When comparison of lipoprotein lipid profiles were made between groups, non-obese women with PCOD had significantly higher total cholesterol, triglycerides and LDL-cholesterol levels than non-obese reference subjects. Obese PCOD women manifested significantly higher total cholesterol, LDL-cholesterol, cholesterol/HDL, and LDL/HDL values than did obese reference subjects. Correlations between serum androgens and lipoprotein lipid concentrations in PCOD and normal women were unhelpful. Both non-obese and obese patients with PCOD had significantly higher systolic and diastolic blood pressures (BPs) than the reference groups. Thus, both non-obese and obese women with PCOD manifest hyperandrogenaemia which may result in a male pattern of lipoprotein lipid concentrations.

  9. Effect of sodium tripolyphosphate concentration and simulated gastrointestinal fluids on release profile of paracetamol from chitosan microsphere

    Science.gov (United States)

    Mulia, Kamarza; Andrie; Krisanti, Elsa A.

    2018-03-01

    The problem to overcome in oral drug administration is the significant pH changes present in the human digestive system. In this study, ionotropic gelation method employing 2-8% (w/v) tripolyphosphate solutions were used to crosslink chitosan microspheres for a controlled release of paracetamol as a model drug. The release profiles of paracetamol from chitosan microspheres were determined using simulated gastrointestinal fluids having pH values of 1.2, 6.8, and 7.4. The results showed that the paracetamol loading and the encapsulation efficiency values increased with increasing concentration of tripolyphosphate solutions used in the preparation step. Paracetamol released at pH 1.2 and 6.8 buffer solutions was significantly higher than that at pH 7.4; also, more paracetamol was released in the presence of α-amylase and β-glucosidase enzymes. The release profiles showed zero-order release behaviour up to 8 hours where the highest drug release was 39% of the paracetamol loaded in the chitosan microspheres, indicating a strong crosslinking between chitosan and TPP anions. The relatively low accumulated drug release could be compensated by employing suitable enzymes, lower TPP solution concentration, and addition of other biodegradable polymer to reduce the TPP crosslink.

  10. What’s normal? Oligosaccharide concentrations and profiles in milk produced by healthy women vary geographically12

    Science.gov (United States)

    Meehan, Courtney L; McGuire, Mark A; Foster, James; Sellen, Daniel W; Kamau-Mbuthia, Elizabeth W; Kamundia, Egidioh W; Mbugua, Samwel; Moore, Sophie E; Prentice, Andrew M; Kvist, Linda J; Otoo, Gloria E; Brooker, Sarah L; Price, William J; Shafii, Bahman; Placek, Caitlyn; Lackey, Kimberly A; Robertson, Bianca; Ruíz, Lorena; Pareja, Rossina G; Bode, Lars

    2017-01-01

    Background: Human milk is a complex fluid comprised of myriad substances, with one of the most abundant substances being a group of complex carbohydrates referred to as human milk oligosaccharides (HMOs). There has been some evidence that HMO profiles differ in populations, but few studies have rigorously explored this variability. Objectives: We tested the hypothesis that HMO profiles differ in diverse populations of healthy women. Next, we examined relations between HMO and maternal anthropometric and reproductive indexes and indirectly examined whether differences were likely related to genetic or environmental variations. Design: In this cross-sectional, observational study, milk was collected from a total of 410 healthy, breastfeeding women in 11 international cohorts and analyzed for HMOs by using high-performance liquid chromatography. Results: There was an effect of the cohort (P 4 times higher in milk collected in Sweden than in milk collected in rural Gambia (mean ± SEM: 473 ± 55 compared with 103 ± 16 nmol/mL, respectively; P < 0.05), and disialyllacto-N-tetraose (DSLNT) concentrations ranged from 216 ± 14 nmol/mL (in Sweden) to 870 ± 68 nmol/mL (in rural Gambia) (P < 0.05). Maternal age, time postpartum, weight, and body mass index were all correlated with several HMOs, and multiple differences in HMOs [e.g., lacto-N-neotetrose and DSLNT] were shown between ethnically similar (and likely genetically similar) populations who were living in different locations, which suggests that the environment may play a role in regulating the synthesis of HMOs. Conclusions: The results of this study support our hypothesis that normal HMO concentrations and profiles vary geographically, even in healthy women. Targeted genomic analyses are required to determine whether these differences are due at least in part to genetic variation. A careful examination of sociocultural, behavioral, and environmental factors is needed to determine their roles in this regard. This

  11. 10Be concentrations and the long-term fate of particle-reactive nuclides in five soil profiles from California

    International Nuclear Information System (INIS)

    Monaghan, M.C.; Krishnaswami, S.; Thomas, J.H.

    1983-01-01

    Concentration-depth profiles of cosmic-ray-produced 10 Be(tsub(1/2)=1.5 m.y.) have been measured by accelerator-mass spectrometry in five soil profiles. These measurements were made in an effort (1) to understand the retentivity of soil surfaces for particle-reactive tracers depositing from the atmosphere on time scales of 10 4 -10 6 years, and (2) to explore the application of 10 Be as a chronometer of geomorphic surface age. The profiles sampled are from two wave-cut terraces located near Mendocino, California, a table mountain top and an alluvial fan, both located near Friant, California. The ages of the Mendocino terraces are inferred to be (1-5) x 10 5 years based on amino-stratigraphic correlations and models of terrace evolution; those of the table mountain top and alluvial fan are 9.5 x 10 6 years and 6.0 x 10 5 years, respectively, based on K-Ar analyses. All the surfaces sampled are nearly flat and exhibit few erosional features. In addition to 10 Be we measured 210 Pb, sup(239,) 240 Pu and 7 Be to ascertain the retentivity of the soils for particle-reactive nuclides and to assess the present-day delivery rate of nuclides from the atmosphere. The 7 Be inventory is 4.0 dpm/cm 2 similar to those observed at nearby locations. The inventories of 210 Pb and Pu isotopes conform to those predicted from model calculations and suggest that the soil surfaces sampled retain the entire burden of particle-reactive nuclides delivered to them over short time scales, approx.= 100 years. The 10 Be concentrations in the sample range between (0.2 and 7) x 10 8 atoms/g soil and show strong correlations with leachable Fe and/or Al. (orig./WL)

  12. Effects of carbon concentration on microstructure and mechanical properties of as-cast nickel-free Co–28Cr–9W-based dental alloys

    International Nuclear Information System (INIS)

    Yamanaka, Kenta; Mori, Manami; Chiba, Akihiko

    2014-01-01

    We determined the effects of carbon concentration on the microstructures and tensile properties of the Ni-free Co–29Cr–9W–1Si–C (mass%) cast alloys used in dental applications. Alloy specimens prepared with carbon concentrations in the range 0.01–0.27 mass% were conventionally cast. Scanning electron microscopy (SEM) and electron probe microanalysis (EPMA) revealed that precipitates had formed in all the alloy specimens. The σ phase, a chromium-rich intermetallic compound, had formed in the region between the dendrite arms of the low-carbon-content (e.g., 0.01C) alloys. Adding carbon to the alloys increased the amount of interdendritic precipitates that formed and changed the precipitation behavior; the precipitated phase changed from the σ phase to the M 23 C 6 carbide with increasing carbon concentration. Adding a small amount of carbon (i.e., 0.04 mass%) to the alloys dramatically enhanced the 0.2% proof stress, which subsequently gradually increased with increasing content of carbon in the alloys. Elongation-to-failure, on the other hand, increased with increasing carbon content and showed a maximum at carbon concentrations of ∼ 0.1 mass%. The M 23 C 6 carbide formed at the interdendritic region may govern the tensile properties of the as-cast Co–Cr–W alloys similar to how it governed those of the hot-rolled alloys prepared in our previous study. - Highlights: • Microstructure and tensile properties of C-doped Co–Cr–W cast alloys was studied. • Adding carbon stabilized the γ matrix and changed the precipitation behavior. • Formation of carbide precipitates strengthened C-doped Co–Cr–Mo alloys. • A maximum tensile elongation was obtained at carbon concentrations of ∼0.1 mass%

  13. Contaminated nickel scrap processing

    International Nuclear Information System (INIS)

    Compere, A.L.; Griffith, W.L.; Hayden, H.W.; Johnson, J.S. Jr.; Wilson, D.F.

    1994-12-01

    The DOE will soon choose between treating contaminated nickel scrap as a legacy waste and developing high-volume nickel decontamination processes. In addition to reducing the volume of legacy wastes, a decontamination process could make 200,000 tons of this strategic metal available for domestic use. Contaminants in DOE nickel scrap include 234 Th, 234 Pa, 137 Cs, 239 Pu (trace), 60 Co, U, 99 Tc, and 237 Np (trace). This report reviews several industrial-scale processes -- electrorefining, electrowinning, vapormetallurgy, and leaching -- used for the purification of nickel. Conventional nickel electrolysis processes are particularly attractive because they use side-stream purification of process solutions to improve the purity of nickel metal. Additionally, nickel purification by electrolysis is effective in a variety of electrolyte systems, including sulfate, chloride, and nitrate. Conventional electrorefining processes typically use a mixed electrolyte which includes sulfate, chloride, and borate. The use of an electrorefining or electrowinning system for scrap nickel recovery could be combined effectively with a variety of processes, including cementation, solvent extraction, ion exchange, complex-formation, and surface sorption, developed for uranium and transuranic purification. Selected processes were reviewed and evaluated for use in nickel side-stream purification. 80 refs

  14. Contaminated nickel scrap processing

    Energy Technology Data Exchange (ETDEWEB)

    Compere, A.L.; Griffith, W.L.; Hayden, H.W.; Johnson, J.S. Jr.; Wilson, D.F.

    1994-12-01

    The DOE will soon choose between treating contaminated nickel scrap as a legacy waste and developing high-volume nickel decontamination processes. In addition to reducing the volume of legacy wastes, a decontamination process could make 200,000 tons of this strategic metal available for domestic use. Contaminants in DOE nickel scrap include {sup 234}Th, {sup 234}Pa, {sup 137}Cs, {sup 239}Pu (trace), {sup 60}Co, U, {sup 99}Tc, and {sup 237}Np (trace). This report reviews several industrial-scale processes -- electrorefining, electrowinning, vapormetallurgy, and leaching -- used for the purification of nickel. Conventional nickel electrolysis processes are particularly attractive because they use side-stream purification of process solutions to improve the purity of nickel metal. Additionally, nickel purification by electrolysis is effective in a variety of electrolyte systems, including sulfate, chloride, and nitrate. Conventional electrorefining processes typically use a mixed electrolyte which includes sulfate, chloride, and borate. The use of an electrorefining or electrowinning system for scrap nickel recovery could be combined effectively with a variety of processes, including cementation, solvent extraction, ion exchange, complex-formation, and surface sorption, developed for uranium and transuranic purification. Selected processes were reviewed and evaluated for use in nickel side-stream purification. 80 refs.

  15. The Potential of The Synergy of Sunphotometer and Lidar Data to Validate Vertical Profiles of The Aerosol Mass Concentration Estimated by An Air Quality Model

    Directory of Open Access Journals (Sweden)

    Siomos N.

    2016-01-01

    Full Text Available Vertical profiles of the aerosol mass concentration derived by the Lidar/Radiometer Inversion Code (LIRIC, that uses combined sunphotometer and lidar data, were used in order to validate the aerosol mass concentration profiles estimated by the air quality model CAMx. Lidar and CIMEL measurements performed at the Laboratory of Atmospheric Physics of the Aristotle University of Thessaloniki, Greece (40.5N, 22.9E from the period 2013-2014 were used in this study.

  16. Identification of intestinal loss of a drug through physiologically based pharmacokinetic simulation of plasma concentration-time profiles.

    Science.gov (United States)

    Peters, Sheila Annie

    2008-01-01

    Despite recent advances in understanding of the role of the gut as a metabolizing organ, recognition of gut wall metabolism and/or other factors contributing to intestinal loss of a compound has been a challenging task due to the lack of well characterized methods to distinguish it from first-pass hepatic extraction. The implications of identifying intestinal loss of a compound in drug discovery and development can be enormous. Physiologically based pharmacokinetic (PBPK) simulations of pharmacokinetic profiles provide a simple, reliable and cost-effective way to understand the mechanisms underlying pharmacokinetic processes. The purpose of this article is to demonstrate the application of PBPK simulations in bringing to light intestinal loss of orally administered drugs, using two example compounds: verapamil and an in-house compound that is no longer in development (referred to as compound A in this article). A generic PBPK model, built in-house using MATLAB software and incorporating absorption, metabolism, distribution, biliary and renal elimination models, was employed for simulation of concentration-time profiles. Modulation of intrinsic hepatic clearance and tissue distribution parameters in the generic PBPK model was done to achieve a good fit to the observed intravenous pharmacokinetic profiles of the compounds studied. These optimized clearance and distribution parameters are expected to be invariant across different routes of administration, as long as the kinetics are linear, and were therefore employed to simulate the oral profiles of the compounds. For compounds with reasonably good solubility and permeability, an area under the concentration-time curve for the simulated oral profile that far exceeded the observed would indicate some kind of loss in the intestine. PBPK simulations applied to compound A showed substantial loss of the compound in the gastrointestinal tract in humans but not in rats. This accounted for the lower bioavailability of the

  17. II. Electrodeposition/removal of nickel in a spouted electrochemical reactor.

    Science.gov (United States)

    Grimshaw, Pengpeng; Calo, Joseph M; Shirvanian, Pezhman A; Hradil, George

    2011-08-17

    An investigation is presented of nickel electrodeposition from acidic solutions in a cylindrical spouted electrochemical reactor. The effects of solution pH, temperature, and applied current on nickel removal/recovery rate, current efficiency, and corrosion rate of deposited nickel on the cathodic particles were explored under galvanostatic operation. Nitrogen sparging was used to decrease the dissolved oxygen concentration in the electrolyte in order to reduce the nickel corrosion rate, thereby increasing the nickel electrowinning rate and current efficiency. A numerical model of electrodeposition, including corrosion and mass transfer in the particulate cathode moving bed, is presented that describes the behavior of the experimental net nickel electrodeposition data quite well.

  18. Free ionic nickel accumulation and localization in the freshwater zooplankter, Daphnia magna

    International Nuclear Information System (INIS)

    Hall, T.M.

    1982-01-01

    The processes which lead to the accumulation of free ionic nickel (radioactive) from solution by Daphnia magna were studied and incorporated into a model which describes accummulation at different concentrations. Adsorption proved to be a relatively small component of nickel accummulation. The accummulation rate eventually approached zero, which represented an equilibrium between uptake and loss of nickel. However, elimination experiments did reveal a pool of relatively static nickel. The appearance and distribution of nickel within five body parts (body fluid, carapace, gut, filtering appendages, and eggs) of D. magna supported the accummulation data and added to the understanding of the pathways of nickel through the organism

  19. Rheological profiling of organogels prepared at critical gelling concentrations of natural waxes in a triacylglycerol solvent.

    Science.gov (United States)

    Patel, Ashok R; Babaahmadi, Mehrnoosh; Lesaffer, Ans; Dewettinck, Koen

    2015-05-20

    The aim of this study was to use a detailed rheological characterization to gain new insights into the gelation behavior of natural waxes. To make a comprehensive case, six natural waxes (differing in the relative proportion of chemical components: hydrocarbons, fatty alcohols, fatty acids, and wax esters) were selected as organogelators to gel high-oleic sunflower oil. Flow and dynamic rheological properties of organogels prepared at critical gelling concentrations (Cg) of waxes were studied and compared using drag (stress ramp and steady flow) and oscillatory shear (stress and frequency sweeps) tests. Although, none of the organogels satisfied the rheological definition of a "strong gel" (G″/G' (ω) ≤ 0.1), on comparing the samples, the strongest gel (highest critical stress and dynamic, apparent, and static yield stresses) was obtained not with wax containing the highest proportion of wax esters alone (sunflower wax, SFW) but with wax containing wax esters along with a higher proportion of fatty alcohols (carnauba wax, CRW) although at a comparatively higher Cg (4%wt for latter compared to 0.5%wt for former). As expected, gel formation by waxes containing a high proportion of lower melting fatty acids (berry, BW, and fruit wax, FW) required a comparatively higher Cg (6 and 7%wt, respectively), and in addition, these gels showed the lowest values for plateau elastic modulus (G'LVR) and a prominent crossover point at higher frequency. The gelation temperatures (TG'=G″) for all the studied gels were lower than room temperature, except for SFW and CRW. The yielding-type behavior of gels was evident, with most gels showing strong shear sensitivity and a weak thixotropic recovery. The rheological behavior was combined with the results of thermal analysis and microstructure studies (optical, polarized, and cryo-scanning electron microscopy) to explain the gelation properties of these waxes.

  20. Gut Microbiota, Microinflammation, Metabolic Profile, and Zonulin Concentration in Obese and Normal Weight Subjects

    Directory of Open Access Journals (Sweden)

    Agnieszka Żak-Gołąb

    2013-01-01

    Full Text Available The association between gut microbiota and circulating zonulin level, a marker of intestinal permeability, has not been studied yet. The aim of the study is the assessment of plasma zonulin, haptoglobin and proinflammatory cytokines (TNF-α and IL-6 levels in relation to composition of gut microbiota in obese and normal weight subjects. Circulating inflammation markers, such as TNF-α, sTNFR1, sTNFR2, IL-6, zonulin, and haptoglobin levels were measured and semiquantitative analysis of gut microbiota composition was carried out in 50 obese and 30 normal weight subjects without concomitant diseases. Higher circulating zonulin, TNF-α, sTNFR1, sTNFR2, and IL-6 levels were found in the obese subjects. Plasma zonulin level correlated positively with age (r=0.43, P<0.001, body mass (r=0.30, P<0.01, BMI (r=0.33, P<0.01, fat mass and fat percentage (r=0.31, P<0.01 and r=0.23, P<0.05, resp.. Positive correlations between bacterial colony count and sTNFR1 (r=0.33, P<0.01 and plasma zonulin (r=0.26, P<0.05 but not haptoglobin levels were found. Additionally, plasma zonulin level was proportional to daily energy intake (r=0.27, P<0.05 and serum glucose concentration (r=0.18, P<0.05 and inversely proportional to diet protein percentage (r=-0.23, P<0.05. Gut microbiota-related systemic microinflammation in the obese is reflected by circulating zonulin level, a potential marker of interstitial permeability.

  1. Nickel and ocean warming affect scleractinian coral growth.

    Science.gov (United States)

    Biscéré, T; Lorrain, A; Rodolfo-Metalpa, R; Gilbert, A; Wright, A; Devissi, C; Peignon, C; Farman, R; Duvieilbourg, E; Payri, C; Houlbrèque, F

    2017-07-15

    The sensitivity of corals and their Symbiodinium to warming has been extensively documented; however very few studies considered that anthropogenic inputs such as metal pollution have already an impact on many fringing reefs. Thus, today, nickel releases are common in coastal ecosystems. In this study, two major reef-building species Acropora muricata and Pocillopora damicornis were exposed in situ to ambient and moderate nickel concentrations on a short-term period (1h) using benthic chamber experiments. Simultaneously, we tested in laboratory conditions the combined effects of a chronic exposure (8weeks) to moderate nickel concentrations and ocean warming on A. muricata. The in situ experiment highlighted that nickel enrichment, at ambient temperature, stimulated by 27 to 47% the calcification rates of both species but not their photosynthetic performances. In contrast, an exposure to higher nickel concentration, in combination with elevated temperature simulated in aquaria, severely depressed by 30% the growth of A. muricata. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Serum concentrations and profiles of polychlorinated biphenyls in Taiwan Yu-cheng victims twenty years after the incident

    Energy Technology Data Exchange (ETDEWEB)

    Lung, S.-C. Candice [Research Center for Environmental Changes, Academia Sinica, Nankang, Taipei, Taiwan 115 (China); Guo, Y.-L.L. [Department of Environmental and Occupational Health, College of Medicine, National Cheng Kung University, 138 Sheng-Li Rd., Tainan, Taiwan 70428 (China); Chang, H.-Y.[Department of Environmental and Occupational Health, College of Medicine, National Cheng Kung University, 138 Sheng-Li Rd., Tainan, Taiwan 70428 (China)]. E-mail: h7154@mail.ncku.edu.tw

    2005-07-15

    In 1979, about 2000 people in central Taiwan were intoxicated via rice oil consumption that was contaminated with polychlorinated biphenyls (PCBs). This 'Yu-cheng' incident was one of the two known major human PCB intoxication episodes. Twenty years after the intoxication, serum samples of 435 Yu-cheng victims, 414 adults and 21 children, were collected. Sixteen PCB congeners were analyzed with a gas chromatograph-electron capture detector. We found the median concentration of total PCBs in the adult serum was 1500 ng/g lipid, still substantially higher than that of the general population in Taiwan (3.7-fold) and most seafood consumers in the world. Most of analyzed PCB congeners in children were below or around the detection limits. Congener no. 138, however, had the highest concentrations, approximately accounting for 55% and 29% in the child and adult groups, respectively. Given that PCBs are persistent organic pollutants and endocrine disruptors, the concentrations and congener-specific profiles regarding the Yu-cheng victims provide valuable information for the investigation of such chemicals in humans. - Total serum PCBs in the Yu-cheng adult victims twenty years after the incident were still higher than that of the general population in Taiwan.

  3. Concentrations of the genotoxic metals, chromium and nickel, in whales, tar balls, oil slicks, and released oil from the gulf of Mexico in the immediate aftermath of the deepwater horizon oil crisis: is genotoxic metal exposure part of the deepwater horizon legacy?

    Science.gov (United States)

    Wise, John Pierce; Wise, James T F; Wise, Catherine F; Wise, Sandra S; Gianios, Christy; Xie, Hong; Thompson, W Douglas; Perkins, Christopher; Falank, Carolyne; Wise, John Pierce

    2014-01-01

    Concern regarding the Deepwater Horizon oil crisis has largely focused on oil and dispersants while the threat of genotoxic metals in the oil has gone largely overlooked. Genotoxic metals, such as chromium and nickel, damage DNA and bioaccumulate in organisms, resulting in persistent exposures. We found chromium and nickel concentrations ranged from 0.24 to 8.46 ppm in crude oil from the riser, oil from slicks on surface waters and tar balls from Gulf of Mexico beaches. We found nickel concentrations ranged from 1.7 to 94.6 ppm wet weight with a mean of 15.9 ± 3.5 ppm and chromium concentrations ranged from 2.0 to 73.6 ppm wet weight with a mean of 12.8 ± 2.6 ppm in tissue collected from Gulf of Mexico whales in the wake of the crisis. Mean tissue concentrations were significantly higher than those found in whales collected around the world prior to the spill. Given the capacity of these metals to damage DNA, their presence in the oil, and their elevated concentrations in whales, we suggest that metal exposure is an important understudied concern for the Deepwater Horizon oil disaster.

  4. Kinetics of oxidation of nickel(II) aza macrocycles by ...

    Indian Academy of Sciences (India)

    The kinetics of the oxidation of nickel (II) hexaaza and nickel (II) pentaaza macrocycles by the peroxydisulphate anion, S2O8 2-, were studied in aqueous media. Effect of H on reaction rate was also studied. The rate increases with increase of S2OO8 2- concentration. Rates are almost independent of acid between H 4 ...

  5. The Impact of a Nickel-Copper Smelter on Concentrations of Toxic Elements in Local Wild Food from the Norwegian, Finnish, and Russian Border Regions.

    Science.gov (United States)

    Hansen, Martine D; Nøst, Therese H; Heimstad, Eldbjørg S; Evenset, Anita; Dudarev, Alexey A; Rautio, Arja; Myllynen, Päivi; Dushkina, Eugenia V; Jagodic, Marta; Christensen, Guttorm N; Anda, Erik E; Brustad, Magritt; Sandanger, Torkjel M

    2017-06-28

    Toxic elements emitted from the Pechenganickel complex on the Kola Peninsula have caused concern about potential effects on local wild food in the border regions between Norway, Finland and Russia. The aim of this study was to assess Ni, Cu, Co, As, Pb, Cd, and Hg concentrations in local wild foods from these border regions. During 2013-2014, we collected samples of different berry, mushroom, fish, and game species from sites at varying distances from the Ni-Cu smelter in all three border regions. Our results indicate that the Ni-Cu smelter is the main source of Ni, Co, and As in local wild foods, whereas the sources of Pb and Cd are more complex. We observed no consistent trends for Cu, one of the main toxic elements emitted by the Ni-Cu smelter; nor did we find any trend for Hg in wild food. Concentrations of all investigated toxic elements were highest in mushrooms, except for Hg, which was highest in fish. EU maximum levels of Pb, Cd, and Hg were exceeded in some samples, but most had levels considered safe for human consumption. No international thresholds exist for the other elements under study.

  6. Quantitative interpretation of Cl, Br and I porewater concentration profiles in lake sediments of Loch Lomond, Scotland

    International Nuclear Information System (INIS)

    Falck, W.E.; Hooker, P.J.

    1991-01-01

    One of the four natural analogue sites being investigated by the British Geological Survey is Loch Lomond, Scotland. Naturally occurring halogen elements (Cl, Br and I) have been migrating from a thin marine horizon into overlying freshwater deposits by a diffusion process which has been occurring for at least 5 400 years. This report summarizes the main findings accumulated since 1983 when the work was first begun, and provides a modelling interpretation of the measured concentration-depth profiles using a new numerical code called Diagen. The release rates of I and Br from the organic matter association in the shallow buried marine layer are very slow; subsequent anion movement by diffusion is affected by tortuosity differences in the sediments rather than by chemical reaction with the sediments. The bulk of the evidence supports conservative transport of iodide, bromide and chloride anions towards the sediment/loch interface. The report discusses some implications of the findings

  7. Seasonal dynamics of soil CO2 efflux and soil profile CO2 concentrations in arboretum of Moscow botanical garden

    Science.gov (United States)

    Goncharova, Olga; Udovenko, Maria; Matyshak, Georgy

    2016-04-01

    To analyse and predict recent and future climate change on a global scale exchange processes of greenhouse gases - primarily carbon dioxide - over various ecosystems are of rising interest. In order to upscale land-use dependent sources and sinks of CO2, knowledge of the local variability of carbon fluxes is needed. Among terrestrial ecosystems, urban areas play an important role because most of anthropogenic emissions of carbon dioxide originate from these areas. On the other hand, urban soils have the potential to store large amounts of soil organic carbon and, thus, contribute to mitigating increases in atmospheric CO2 concentrations. Research objectives: 1) estimate the seasonal dynamics of carbon dioxide production (emission - closed chamber technique and profile concentration - soil air sampling tubes method) by soils of Moscow State University Botanical Garden Arboretum planted with Picea obovata and Pinus sylvestris, 1) identification the factors that control CO2 production. The study was conducted with 1-2 weeks intervals between October 2013 and November 2015 at two sites. Carbon dioxide soil surface efflux during the year ranged from 0 to 800 mgCO2/(m2hr). Efflux values above 0 mgCO2/(m2hr) was observed during the all cold period except for only 3 weeks. Soil CO2 concentration ranged from 1600-3000 ppm in upper 10-cm layer to 10000-40000 ppm at a depth of 60 cm. The maximum concentrations of CO2 were recorded in late winter and late summer. We associate it with high biological activity (both heterotrophic and autotrophic) during the summer, and with physical gas jamming in the winter. The high value of annual CO2 production of the studied soils is caused by high organic matter content, slightly alkaline reaction, good structure and texture of urban soils. Differences in soil CO2 production by spruce and pine urban forest soils (in the pine forest 1.5-2.0 times higher) are caused by urban soil profiles construction, but not temperature regimes. Seasonal

  8. Amino acid profile of metabolisable protein in lactating dairy cows is affected by dry matter concentration in grass-clover silage

    DEFF Research Database (Denmark)

    Johansen, Marianne; Lund, Peter; Weisbjerg, Martin Riis

    2018-01-01

    Our previous study showed that supply of metabolisable protein (MP) to lactating dairy cows increased with increasing dry matter (DM) concentration in grass-clover silage. The aim of this study was to examine how amino acid (AA) profile of MP was affected by silage DM concentration. Eight grass-c...

  9. II. Electrodeposition/removal of nickel in a spouted electrochemical reactor

    OpenAIRE

    Grimshaw, Pengpeng; Calo, Joseph M.; Shirvanian, Pezhman A.; Hradil, George

    2011-01-01

    An investigation is presented of nickel electrodeposition from acidic solutions in a cylindrical spouted electrochemical reactor. The effects of solution pH, temperature, and applied current on nickel removal/recovery rate, current efficiency, and corrosion rate of deposited nickel on the cathodic particles were explored under galvanostatic operation. Nitrogen sparging was used to decrease the dissolved oxygen concentration in the electrolyte in order to reduce the nickel corrosion rate, ther...

  10. Serum Adiponectin and Leptin Concentrations in Relation to Body Fat Distribution, Hematological Indices and Lipid Profile in Humans

    Directory of Open Access Journals (Sweden)

    Anna Lubkowska

    2015-09-01

    Full Text Available The purpose of the study was to evaluate the relationship between serum adiponectin and leptin concentrations and body composition, hematological indices and lipid profile parameters in adults. The study involved 95 volunteers (BMI from 23.3 to 53 kg/m2. Anthropometric parameters were measured: body weight and height, waist and hip circumference, waist-to-hip ratio, body fat mass (BMF, subcutaneous and visceral fat mass (SFM, VFM, lean body mass (LBM, skeletal muscle mass (SMM. In serum we determined adiponectin and leptin concentrations, extracellular hemoglobin, total bilirubin, as well as lipid metabolism (TCh, HDL-Ch, LDL-Ch, TG. Mean adipokine levels were significantly higher in women (p ≤ 0.01, adiponectin significantly negatively correlated with body height and weight, systolic blood pressure and absolute LBM and SMM values. The same relation was observed for erythroid system indicators and lipid indicators. A positive correlation was exceptionally found between adiponectin and HDL-Ch. LEP negatively correlated with some percentage rates (%LBM, %SMM. Only in women, we observed a positive correlation between LEP and body weight, BMI and WHR. Studies on ADPN and the ADPN/LEP ratio as a valuable complementary diagnostic element in the prediction and prevention of cardiovascular diseases need to be continued.

  11. Estimation of suspended sediment concentration from Acoustic Doppler Current Profiler (ADCP) instrument: A case study of Lembeh Strait, North Sulawesi

    Science.gov (United States)

    Dwinovantyo, Angga; Manik, Henry M.; Prartono, Tri; Susilohadi; Ilahude, Delyuzar

    2017-01-01

    Measurement of suspended sediment concentration (SSC) is one of the parameters needed to determine the characteristics of sediment transport. However, the measurement of SSC nowadays still uses conventional technique and it has limitations; especially in temporal resolution. With advanced technology, the measurement can use hydroacoustic technology such as Acoustic Doppler Current Profiler (ADCP). ADCP measures the intensity of backscatter as echo intensity unit from sediment particles. The frequency of ADCP used in this study was 400 kHz. The samples were measured and collected from Lembeh Strait, North Sulawesi. The highest concentration of suspended sediment was 98.89 mg L-1 and the lowest was 45.20 mg L-1. Time series data showed the tidal condition affected the SSC. From the research, we also made correction from sound signal losses effect such as spherical spreading and sound absorption to get more accurate results by eliminating these parameters in echo intensity data. Simple linear regression analysis at echo intensity measured from ADCP to direct measurement of SSC was performed to obtain the estimation of the SSC. The comparison result of estimation of SSC from ADCP measurements and SSC from laboratory analyses was insignificantly different based on t-test statistical analysis with 95% confidence interval percentage.

  12. Method for regeneration of electroless nickel plating solution

    Science.gov (United States)

    Eisenmann, E.T.

    1997-03-11

    An electroless nickel(EN)/hypophosphite plating bath is provided employing acetic acid/acetate as a buffer and which is, as a result, capable of perpetual regeneration while avoiding the production of hazardous waste. A regeneration process is provided to process the spent EN plating bath solution. A concentrated starter and replenishment solution is provided for ease of operation of the plating bath. The regeneration process employs a chelating ion exchange system to remove nickel cations from spent EN plating solution. Phosphites are then removed from the solution by precipitation. The nickel cations are removed from the ion exchange system by elution with hypophosphorus acid and the nickel concentration of the eluate adjusted by addition of nickel salt. The treated solution and adjusted eluate are combined, stabilizer added, and the volume of resulting solution reduced by evaporation to form the bath starter and replenishing solution. 1 fig.

  13. Method for regeneration of electroless nickel plating solution

    Science.gov (United States)

    Eisenmann, Erhard T.

    1997-01-01

    An electroless nickel(EN)/hypophosphite plating bath is provided employing acetic acid/acetate as a buffer and which is, as a result, capable of perpetual regeneration while avoiding the production of hazardous waste. A regeneration process is provided to process the spent EN plating bath solution. A concentrated starter and replenishment solution is provided for ease of operation of the plating bath. The regeneration process employs a chelating ion exchange system to remove nickel cations from spent EN plating solution. Phosphites are then removed from the solution by precipitation. The nickel cations are removed from the ion exchange system by elution with hypophosphorous acid and the nickel concentration of the eluate adjusted by addition of nickel salt. The treated solution and adjusted eluate are combined, stabilizer added, and the volume of resulting solution reduced by evaporation to form the bath starter and replenishing solution.

  14. Chemical nickel plating in tartrate solutions with borohydride reducing agent

    International Nuclear Information System (INIS)

    Plokhov, V.A.

    1986-01-01

    The authors investigate the influence of various factors on the rate of chemical nickel plating in strongly alkaline tartrate solutions with a borohydride reducing agent. After 30 min of the process of nickel plating, the final concentration of sodium borohydride decreases to 0.26 g/liter, leading to stoppage of the process. The nickel plating process can be intensified by increasing the concentration of sodium hydroxide in the solution, suppressing hydrolysis of borohydride, and also by introducing additives which suppress hydrolysis of borohydride. For chemical deposition of nickel-boron coatings from tartrate solutions the authors recommend the following composition (g/liter): nickel chloride 15-25, Rochelle salt 450-550, sodium hydroxide 140-160, sodium borohydride 0.8-1.0, thallium nitrate 0.003-0.008. The process temperature is 92-95 C, and the deposition rate is 4-6 um/h

  15. Producing bio-filter for absorbing and separating stable nickel and feasibility study to separate radioactive nickel by microorganisms

    International Nuclear Information System (INIS)

    Ghafourian, H.; Rabbani, M.; Naseri, Y.; Sadeghi, S.

    2004-01-01

    In this research work, bio absorption of nickel has been investigated by new 16 various bacterial strains isolated from Ramsar warm springs. As the obtained results show a strain of gram negative cocobacilluse bacteria is highly capable to take up nickel in optimum pH about 6. The effect of nickel solution concentrations in 20-200 ppm have been studied. Uptake capacity of bacterial biomass regarding to concentrations below 150 ppm is most highly and nearly constant, but it will be decreased over 150 ppm, and in 200 ppm absorption of nickel reaches to near zero. No nickel was taken up by bacterial biomass. Further studies showed that after 60 minutes of contact time, Nickel uptake reaches maximum by 53%. Considering the uptake mechanism revealed that bio sorption was very limited and the uptake mainly occurs through a accumulation dependent on metabolic activities. Also the results show that the presence of the other cations such as Zn 2+ , Cu 2+ and Pb 2+ is ineffective to biological uptake of nickel. Nickel taken up by biomass can be easily recovered by HNO 3 with the concentration of 0.1 M

  16. Retention of atmospheric Cu, Ni, Cd and Zn in an ombrotrophic peat profile near the Outokumpu Cu-Ni mine, SE-Finland

    Science.gov (United States)

    Rausch, N.; Nieminen, T. M.; Ukonmaanaho, L.; Cheburkin, A.; Krachler, M.; Shotyk, W.

    2003-05-01

    Peat cores taken from ombrotrophic bogs are widely used to reconstruct historical records of atmospheric lead and mercury déposition[1, 2]. In this study, the retention of copper, nickel, cadmium and zinc in peat bogs are studied by comparing high resolution, age dated concentration profiles with emissions from the main local source, the Outokumpu copper-nickel mine. An ombrotrophic peat core was taken from the vicinity of Outokumpu, E Finland. Copper and zinc concentrations of dry peat were measured by XRF, cadmium and nickel by GF-AAS, and sample ages by 210Pb. Only copper and nickel show enhanced concentrations in layers covering the mining period, indicating a retention of these elements. However, the more detailed comparison of ore production rates and concentrations in age-dated samples show clearly that only copper is likely to be permanently fixed, while nickel doesn't reflect the mining activity. Even though copper is retained in the upper part of the profile, a possible redeposition of this element by secondary processes (e.g., water table fluctuations) can not be excluded. This question will be resolved by further investigations, e.g. by pore water profiles.

  17. Profile of Rumen Fermentation and Blood Urea Nitrogen Concentration of Kacang Goat Fed Total Mixed Ration Vs. Roughage

    Science.gov (United States)

    Adiwinarti, R.; Kustantinah; Budisatria, I. G. S.; Rusman; Indarto, E.

    2018-02-01

    Kacang goat is usually reared traditionally fed natural grass and having inferior performance. Many researches had been done to improve the performance. Total mixed ration (TMR) containing soybean meal (SBM) and fish meal (FM) could increase the performance of Kacang goat, but the profile of rumen fermentation has not been published. Therefore, this study investigated the profile of rumen fermentation and blood urea Nitrogen concentration (BUN) in Kacang goat fed natural grass (roughage) and TMR. Twelve yearling Kacang buck, 15.2-19.6 kg were arranged in completely randomized design. The treatments were NG (natural grass), FM (TMR containing FM), and SBM (TMR containing SBM). The TMR were formulated containing 15% crude protein and 56-58% TDN. Data were analyzed by one way ANOVA. Rumen pH 6 hours after feeding of NG (7.4) was higher (P<0.01) than that of FM (6.2) and SBM (6.4). This lowering pH of TMR was caused by increasing volatile fatty acids (VFA). The VFA total of FM (129.7 mmol/l) and SBM (153.1 mmol/l) were higher than that of NG (86.4 mmol/l). At 3 and 6 hours after feeding, ammonia in the rumen of SBM was higher than that of NG and FM, indicating higher degraded protein. The BUN at 3 hours after feeding of SBM was higher than that of NG. It can be concluded that protein in SBM was degraded higher than others and the lower pH in rumen of TMR goats was caused by higher VFA produced by TMR goats compared to NG goats.

  18. Structure investigations of electrodeposited nickel

    International Nuclear Information System (INIS)

    Vertes, A.; Czako-Nagy, I.; Lakatos-Varsanyi, M.; Brauer, G.; Leidheiser, H. Jr

    1981-01-01

    Electrodeposited nickel samples were investigated by positron annihilation (lifetime and Doppler-broadening), Moessbauer effect and X-ray diffraction measurements. Two-component positron lifetime spectra were obtained. The first component is thought to result from bulk annihilation and trapping at single trapping centres (TC), their concentrations are obtained from the trapping model. The second one possibly denotes annihilation at voids, the number of which is dependent on the stress in the deposit. The Moessbauer results show differences in the magnetic orientation in the three samples examined. (author)

  19. Gene expression profiling of a Zn-tolerant and a Zn-sensitive Suillus luteus isolate exposed to increased external zinc concentrations

    OpenAIRE

    MULLER, Ludo; Craciun, A. R.; RUYTINX, Joske; LAMBAERTS, Marc; Verbruggen, N.; VANGRONSVELD, Jaco; COLPAERT, Jan

    2007-01-01

    Complementary DNA (cDNA)-amplified fragment-length polymorphism (AFLP) was applied to analyze transcript profiles of a Zn-tolerant and a Zn-sensitive isolate of the ectomycorrhizal basidiomycete Suillus luteus, both cultured with and without increased external zinc concentrations. From the obtained transcript profiles that covered approximately 2% of the total expected complement of genes in S. luteus, 144 nonredundant, differentially expressed transcript-derived fragments (TDFs), falling in ...

  20. Synthesis, structure characterization and catalytic activity of nickel tungstate nanoparticles

    Science.gov (United States)

    Pourmortazavi, Seied Mahdi; Rahimi-Nasrabadi, Mehdi; Khalilian-Shalamzari, Morteza; Zahedi, Mir Mahdi; Hajimirsadeghi, Seiedeh Somayyeh; Omrani, Ismail

    2012-12-01

    Taguchi robust design was applied to optimize experimental parameters for controllable, simple and fast synthesis of nickel tungstate nanoparticles. NiWO4 nanoparticles were synthesized by precipitation reaction involving addition of nickel ion solution to the tungstate aqueous reagent and then formation of nickel tungstate nucleolus which are insoluble in aqueous media. Effects of various parameters such as nickel and tungstate concentrations, flow rate of reagent addition and reactor temperature on diameter of synthesized nickel tungstate nanoparticles were investigated experimentally by the aid of orthogonal array design. The results for analysis of variance (ANOVA) showed that particle size of nickel tungstate can be effectively tuned by controlling significant variables involving nickel and tungstate concentrations and flow rate; while, temperature of the reactor has a no considerable effect on the size of NiWO4 particles. The ANOVA results proposed the optimum conditions for synthesis of nickel tungstate nanoparticles via this technique. Also, under optimum condition nanoparticles of NiWO4 were prepared and their structure and chemical composition were characterized by means of EDAX, XRD, SEM, FT-IR spectroscopy, UV-vis spectroscopy, and photoluminescence. Finally, catalytic activity of the nanoparticles in a cycloaddition reaction was examined.

  1. Adverse effects of nickel in transosseous wires and surgical implants: literature review.

    Science.gov (United States)

    Nwashindi, A; Dim, E M

    2014-01-01

    Transosseous wires used in the management of fractures are stainless steel alloys which contain nickel 14.5%, chromium 17.6%, iron 62.5% and molybdenum 2.8%. Gradual disintegration of the transosseous wires release nickel into the blood leading to increase nickel concentration in the blood. Nickel has been found to have some adverse systemic effects on the body. The aim of this paper is to discuss the sources of Nickel in the body as well as the systemic adverse effects of Nickel as a degradation product of stainless steel surgical implants. A study of pertinent literature on nickel as a content of stainless steel alloy used in implant surgery was done, taking note also of other sources of nickel in the body, the toxicokinetics of nickel and the related adverse effects of this metal and its compound in humans. As outcome,the sources of human exposure to nickel,distribution and metabolism of nickel in the body, host responseto stainless steel wires and the adverse effects of nickel in the body are presented. It may be necessary to discourage the use of wires or implants containing nickel in the management of fractures.The need for removal of these implants after they have served their purposes is emphasized.

  2. Void swelling and segregation in dilute nickel alloys

    International Nuclear Information System (INIS)

    Potter, D.I.; Rehn, L.E.; Okamoto, P.R.; Wiedersich, H.

    1977-01-01

    Five binary alloys containing 1 at.% of Al, Ti, Mo, Si and Be in nickel were irradiated at temperatures from 525 to 675 0 C with 3.5-MeV 58 Ni + ions. The resultant microstructures were examined by TEM, and void diameters, number densities and swelling are presented for each alloy over the temperature interval investigated. A systematic relation between solute misfit (size factor) and void swelling is established for these alloys. Solute concentration profiles near the irradiated surface were determined and these also exhibited a systematic behavior--undersize solutes segregated to the surface, whereas oversize solutes were depleted. The results are consistent with calculations based on strong interstitial-solute trapping by undersize solutes and vacancy-solute trapping by oversize solutes that are weak interstitial traps

  3. Saturation volume changes and resistivity changes in nickel

    International Nuclear Information System (INIS)

    Birtcher, R.C.; Blewitt, T.H.

    1976-01-01

    Saturation defect concentrations generated by thermal neutron irradiation of 235 U doped nickel at liquid helium temperature were measured by changes in electrical resistivity and volume. The experimental procedure is described

  4. Phytoremediation of cadmium and nickel by Spirodela polyrhiza

    International Nuclear Information System (INIS)

    Chaudhuri, Devaleena; Goswami, Chandrima; Chatterjee, Sumon; Majumder, Arunabha; Mishra, A.K.; Bandyopadhyay, Kaushik

    2011-01-01

    Heavy metal pollution in surface and groundwater has considerably increased in the last few years. It is essential to have an effective removal mechanism of these toxic metals. Current research includes the need to develop environment friendly and cost effective technologies for removing heavy metals from water. In several studies cadmium and nickel have been considerably removed using phytoremediation. The removal efficiency of cadmium and nickel by Spirodela polyrhiza, common duckweed has been examined in the present study for 3 different concentrations of cadmium (1, 2 and 3 mg/L) and nickel (4, 5 and 6 mg/L). Two sets of experiments for cadmium and nickel were conducted separately. Effect of metal toxicity on Spirodela polyrhiza was evaluated in terms of relative growth factor and cadmium was found to be more toxic than nickel. Under experimental condition BCF value for cadmium removal was more than >1000 in all the 3 concentrations of cadmium. But the BCF value was found to be more than > 1000 only when input nickel concentration was 4 mg/L during phytoremediation process. Experimental results suggest that Spirodela polyrhiza has the potential of accumulating cadmium and nickel from aqueous solution at lower metal concentration. (author)

  5. Bioadsorption of nickel Mining Company by residual biomass Phyllanthus Orbicularis

    Directory of Open Access Journals (Sweden)

    Ariel Díaz-Puig

    2017-01-01

    Full Text Available Kinetic parameters for the adsorption of nickel were studied in the waste CalcinationPlant Company Ernesto Che Guevara biomass Phyllanthus orbicularis synthetic and industrial waste Calcination Plant enterprise solutions. The results showed that the major factors influencing the adsorption capacity of the biomass increases with increasing pH and the initial concentration of nickel in the effluent and is reduced by increasing the biomass concentration. Meanwhile, the removal efficiency of residual nickel increases with increasing pH and concentration of biomass and reduced when the initial concentration of nickel in the effluent increases. The adsorption capacity nickel biomass Phyllanthus orbicularis from synthetic solutions and industrial waste Calcination Plant Company Nickel "Comandante Ernesto Che Guevara" was 44,05 and 26,25 mg/g respectively. The adsorption process nickel biomass Phyllanthus orbicularis follows kinetics pseudo-second order and according to the values of free energy of adsorption obtained through model-RadushkevichDubinin was 267,26 kJ/mol, this nature demonstrates that corresponds to a process mediated by chemical adsorption where the formation of stable bonds between the functional groups present in the biomass and the metal ions predominates.

  6. Molar concentration-depth profiles at the solution surface of a cationic surfactant reconstructed with angle resolved X-ray photoelectron spectroscopy

    International Nuclear Information System (INIS)

    Wang Chuangye; Morgner, Harald

    2011-01-01

    In the current work, we first reconstructed the molar fraction-depth profiles of cation and anion near the surface of tetrabutylammonium iodide dissolved in formamide by a refined calculation procedure, based on angle resolved X-ray photoelectron spectroscopy experiments. In this calculation procedure, both the transmission functions of the core levels and the inelastic mean free paths of the photoelectrons have been taken into account. We have evaluated the partial molar volumes of surfactant and solvent by the densities of such solutions with different bulk concentrations. With those partial molar volumes, the molar concentration-depth profiles of tetrabutylammonium ion and iodide ion were determined. The surface excesses of both surfactant ions were then achieved directly by integrating these depth profiles. The anionic molar concentration-depth profiles and surface excesses have been compared with their counterparts determined by neutral impact ion scattering spectroscopy. The comparisons exhibit good agreements. Being capable of determining molar concentration-depth profiles of surfactant ions by core levels with different kinetic energies may extend the applicable range of ARXPS in investigating solution surfaces.

  7. Nitrogen solubility in nickel base multicomponent melts

    International Nuclear Information System (INIS)

    Bol'shov, L.A.; Stomakhin, A.Ya.; Sokolov, V.M.; Teterin, V.G.

    1984-01-01

    Applicability of various methods for calculation of nitrogen solubility in high-alloyed nickel base alloys, containing Cr, Fe, W, Mo, Ti, Nb, has been estimated. A possibility is shown to use the formUla, derived for the calculation of nitrogen solubility in iron on the basis of statistical theory for a grid model of solution which does not require limitations for the content of a solvent component. The calculation method has been used for nickel alloys, with the concentration of solvent, iron, being accepted equal to zero, and employing parameters of nitrogen interaction as determined for iron-base alloys

  8. A Study on the Effect of Electrodeposition Parameters on the Morphology of Porous Nickel Electrodeposits

    Science.gov (United States)

    Sengupta, Srijan; Patra, Arghya; Jena, Sambedan; Das, Karabi; Das, Siddhartha

    2018-03-01

    In this study, the electrodeposition of nickel foam by dynamic hydrogen bubble-template method is optimized, and the effects of key deposition parameters (applied voltage and deposition time) and bath composition (concentration of Ni2+, pH of the bath, and roles of Cl- and SO4 2- ions) on pore size, distribution, and morphology and crystal structure are studied. Nickel deposit from 0.1 M NiCl2 bath concentration is able to produce the honeycomb-like structure with regular-sized holes. Honeycomb-like structure with cauliflower morphology is deposited at higher applied voltages of 7, 8, and 9 V; and a critical time (>3 minutes) is required for the development of the foamy structure. Compressive residual stresses are developed in the porous electrodeposits after 30 seconds of deposition time (-189.0 MPa), and the nature of the residual stress remains compressive upto 10 minutes of deposition time (-1098.6 MPa). Effect of pH is more pronounced in a chloride bath compared with a sulfate bath. The increasing nature of pore size in nickel electrodeposits plated from a chloride bath (varying from 21 to 48 μm), and the constant pore size (in the range of 22 to 24 μm) in deposits plated from a sulfate bath, can be ascribed to the striking difference in the magnitude of the corresponding current-time profiles.

  9. Evaluation of air jet erosion profiles in metal mesh supported SCR plate catalyst based on glass fiber concentrations

    Science.gov (United States)

    Rajath, S.; Nandakishora, Y.; Siddaraju, C.; Roy, Sukumar

    2018-04-01

    This paper explains the evaluation of erosion profiles in metal mesh supported SCR plate catalyst structures in which the glass fibers concentration in the catalyst material is considered as prime factor for erosion resistance and mechanical strength. The samples are prepared and tested at the specified and constant conditions like velocity as 30m/s, sand flow rate as 2g/min, average particle diameter 300 µm and all these samples were tested at different angles at impact preferably 15°,30°,45°,60°,75°,and 90° as per ASTM G76 standards. Say, if 5% glass fibers are present in catalyst material, then erosion resistance increases, but the density of glass fibers is very less because each glass fiber is approximately 20 microns in diameter and weight of individual is negligible. The composition in which 2% fiber is present has slightly higher erosion comparatively, but 3% glass fibers or more foreign inclusion like excessive binders can be eliminated that contributes much for the conversion of NOx. So 2% -3% glass fibers are preferred and optimized based on NOx conversion and erosion resistance property.

  10. Urinary arsenic speciation profiles in mice subchronically exposed to low concentrations of sodium arsenate in drinking water

    Directory of Open Access Journals (Sweden)

    Huijie Wu

    2011-09-01

    Full Text Available Arsenic is a proven human carcinogen. Although the mechanism of its carcinogenicity is still largely unknown, methylation is thought to have an important role to play in arsenic toxicity. In this study, urinary methylation profiles were investigated in female C57BL/6J black mice given drinking water containing 500 μg arsenate (AsV/L, 250 μg AsV/L, or 100 μg AsV/L as sodium arsenate for 2 months. The concentrations of arsenic chosen reflected those in the drinking water often encountered in arsenic-endemic areas. Urine samples were collected from the mice at the end of the exposure period, and the arsenic species were analyzed by high performance liquid chromatography-inductively coupled plasma-mass spectrometry. All detectable arsenic species showed strong linear correlation with the administered dosage. The methylation patterns were similar in all three groups with a slight decrease of dimethylarsinic acid/AsV ratio in the 500-μg/L group, which corresponded to the significantly higher arsenic retention in the tissue. The results indicate that urinary arsenic could be used as a good biomarker for internal dose and potential biological effects. Different doses of arsenic exposure could result in different degrees of methylation, excretion, and tissue retention, and this may contribute to the understanding of arsenic carcinogenicity.

  11. Tethered balloon-based particle number concentration, and size distribution vertical profiles within the lower troposphere of Shanghai

    Science.gov (United States)

    Zhang, Kun; Wang, Dongfang; Bian, Qinggen; Duan, Yusen; Zhao, Mengfei; Fei, Dongnian; Xiu, Guangli; Fu, Qingyan

    2017-04-01

    A tethered balloon-based measurement campaign of particle number concentration (PNC) and particle number size distribution (PNSD) in the size range of 15.7-661.2 nm was conducted within the lower troposphere of 1000 m in Shanghai, a Chinese megacity, during December of 2015. The meteorological conditions, PNC, and PNSD were synchronously measured at the ground-based station as well as by the tethered balloon. On ground level, the 88.2 nm particles were found to have the highest PNC. The Pearson correlation analysis based on the ground level data showed NO2 had a strong correlation with PNC. The synchronous measurement of PNC and PNSD at the ground station and on the tethered balloon showed that the 15.7-200 nm particles had higher PNC on ground level, but the PNC of 200-661.2 nm particles was higher at 400 m. One haze event (Dec 22nd-Dec 23rd) was selected for detailed discussion on the variation of vertical profiles of PNSD and PNC. The vertical distribution of characteristics of PNC and PNSD were observed and compared. Results indicated that the highest MaxDm (the diameter with the highest PNC) during those three launches all appeared at a high altitude, usually above 300 m. Compared to the clean days, the relatively bigger MaxDm at each height in the haze days also indicated regional transport of pollutants might contribute to more to that haze event.

  12. Nickel in tap water

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, K E; Nielsen, G D; Flyvholm, M A; Fregert, S; Gruvberge, B

    1983-03-01

    Nickel analyses of tap water from several sources in Copenhagen gave up to 490 X 10(-6) g X 1(-1) in the first 250 ml portions. Hot water gave higher values than cold water. After flushing for 5 min, low values were found. Considerable variation from time to time and from tap to tap was found. Drinking of only the first portion in the morning might have an influence on nickel hand eczema.

  13. Separation and Precipitation of Nickel from Acidic Sulfate Leaching Solution of Molybdenum-Nickel Black Shale by Potassium Nickel Sulfate Hexahydrate Crystallization

    Science.gov (United States)

    Deng, Zhigan; Wei, Chang; Fan, Gang; Li, Xingbin; Li, Minting; Li, Cunxiong

    2018-02-01

    Nickel was separated and precipitated with potassium nickel sulfate hexahydrate [K2Ni(SO4)2·6H2O] from acidic sulfate solution, a leach solution from molybdenum-nickel black shale. The effects of the potassium sulfate (K2SO4) concentration, crystallization temperature, solution pH, and crystallization time on nickel(II) recovery and iron(III) precipitation were investigated, revealing that nickel and iron were separated effectively. The optimum parameters were K2SO4 concentration of 200 g/L, crystallization temperature of 10°C, solution pH of 0.5, and crystallization time of 24 h. Under these conditions, 97.6% nickel(II) was recovered as K2Ni(SO4)2·6H2O crystals while only 2.0% of the total iron(III) was precipitated. After recrystallization, 98.4% pure K2Ni(SO4)2·6H2O crystals were obtained in the solids. The mother liquor was purified by hydrolysis-precipitation followed by cooling, and more than 99.0% K2SO4 could be crystallized. A process flowsheet was developed to separate iron(III) and nickel(II) from acidic-sulfate solution.

  14. Vertical distribution of chlorophyll a concentration and phytoplankton community composition from in situ fluorescence profiles: a first database for the global ocean

    Science.gov (United States)

    Sauzède, R.; Lavigne, H.; Claustre, H.; Uitz, J.; Schmechtig, C.; D'Ortenzio, F.; Guinet, C.; Pesant, S.

    2015-10-01

    In vivo chlorophyll a fluorescence is a proxy of chlorophyll a concentration, and is one of the most frequently measured biogeochemical properties in the ocean. Thousands of profiles are available from historical databases and the integration of fluorescence sensors to autonomous platforms has led to a significant increase of chlorophyll fluorescence profile acquisition. To our knowledge, this important source of environmental data has not yet been included in global analyses. A total of 268 127 chlorophyll fluorescence profiles from several databases as well as published and unpublished individual sources were compiled. Following a robust quality control procedure detailed in the present paper, about 49 000 chlorophyll fluorescence profiles were converted into phytoplankton biomass (i.e., chlorophyll a concentration) and size-based community composition (i.e., microphytoplankton, nanophytoplankton and picophytoplankton), using a method specifically developed to harmonize fluorescence profiles from diverse sources. The data span over 5 decades from 1958 to 2015, including observations from all major oceanic basins and all seasons, and depths ranging from the surface to a median maximum sampling depth of around 700 m. Global maps of chlorophyll a concentration and phytoplankton community composition are presented here for the first time. Monthly climatologies were computed for three of Longhurst's ecological provinces in order to exemplify the potential use of the data product. Original data sets (raw fluorescence profiles) as well as calibrated profiles of phytoplankton biomass and community composition are available on open access at PANGAEA, Data Publisher for Earth and Environmental Science. Raw fluorescence profiles: http://doi.pangaea.de/10.1594/PANGAEA.844212 and Phytoplankton biomass and community composition: http://doi.pangaea.de/10.1594/PANGAEA.844485

  15. Specification and prediction of nickel mobilization using artificial intelligence methods

    Science.gov (United States)

    Gholami, Raoof; Ziaii, Mansour; Ardejani, Faramarz Doulati; Maleki, Shahoo

    2011-12-01

    Groundwater and soil pollution from pyrite oxidation, acid mine drainage generation, and release and transport of toxic metals are common environmental problems associated with the mining industry. Nickel is one toxic metal considered to be a key pollutant in some mining setting; to date, its formation mechanism has not yet been fully evaluated. The goals of this study are 1) to describe the process of nickel mobilization in waste dumps by introducing a novel conceptual model, and 2) to predict nickel concentration using two algorithms, namely the support vector machine (SVM) and the general regression neural network (GRNN). The results obtained from this study have shown that considerable amount of nickel concentration can be arrived into the water flow system during the oxidation of pyrite and subsequent Acid Drainage (AMD) generation. It was concluded that pyrite, water, and oxygen are the most important factors for nickel pollution generation while pH condition, SO4, HCO3, TDS, EC, Mg, Fe, Zn, and Cu are measured quantities playing significant role in nickel mobilization. SVM and GRNN have predicted nickel concentration with a high degree of accuracy. Hence, SVM and GRNN can be considered as appropriate tools for environmental risk assessment.

  16. An evaluation of airborne nickel, zinc, and lead exposure at hot dip galvanizing plants.

    Science.gov (United States)

    Verma, D K; Shaw, D S

    1991-12-01

    Industrial hygiene surveys were conducted at three hot dip galvanizing plants to determine occupational exposure to nickel, zinc, and lead. All three plants employed the "dry process" and used 2% nickel, by weight, in their zinc baths. A total of 32 personal and area air samples were taken. The air samples were analyzed for nickel, zinc, and lead. Some samples were also analyzed for various species of nickel (i.e., metallic, soluble, and oxidic). The airborne concentrations observed for nickel and its three species, zinc, and lead at the three plants were all well below the current and proposed threshold limit values recommended by the American Conference of Governmental Industrial Hygienists (ACGIH).

  17. Use of radioactive tracers in chemical reactions. the displacement of zinc-nickel complexes with quantitative determination of nickel

    International Nuclear Information System (INIS)

    Mazzilli, B.; Saiki, M.

    1983-01-01

    The present paper presents a method for the determination of small quantities of nickel radioactive tracers. An analytical application of the displacement reaction between nickel and zinc ethylenediaminetetraacetate labeled with zinc-65 is pursued. This method is based on the extraction of radioactive zinc displaced by nickel from the zinc chelate into a dithizone-carbon tetrachloride solution and the subsequent measurement of the activity of an aliquot of the extract. The method is very sensitive and nickel can be measured in concentrations as small as 0.1 μg/ml or even less, depending on the specific activity of the radioreagent used. The precision and the accuracy of the method are determined. The problem of interferences is also investigated and an attempt is made in order to eliminate them by using masking agents or by means of a previous separation between nickel and other interfering metals. (Author) [pt

  18. Quantification of Hydrogen Concentrations in Surface and Interface Layers and Bulk Materials through Depth Profiling with Nuclear Reaction Analysis.

    Science.gov (United States)

    Wilde, Markus; Ohno, Satoshi; Ogura, Shohei; Fukutani, Katsuyuki; Matsuzaki, Hiroyuki

    2016-03-29

    Nuclear reaction analysis (NRA) via the resonant (1)H((15)N,αγ)(12)C reaction is a highly effective method of depth profiling that quantitatively and non-destructively reveals the hydrogen density distribution at surfaces, at interfaces, and in the volume of solid materials with high depth resolution. The technique applies a (15)N ion beam of 6.385 MeV provided by an electrostatic accelerator and specifically detects the (1)H isotope in depths up to about 2 μm from the target surface. Surface H coverages are measured with a sensitivity in the order of ~10(13) cm(-2) (~1% of a typical atomic monolayer density) and H volume concentrations with a detection limit of ~10(18) cm(-3) (~100 at. ppm). The near-surface depth resolution is 2-5 nm for surface-normal (15)N ion incidence onto the target and can be enhanced to values below 1 nm for very flat targets by adopting a surface-grazing incidence geometry. The method is versatile and readily applied to any high vacuum compatible homogeneous material with a smooth surface (no pores). Electrically conductive targets usually tolerate the ion beam irradiation with negligible degradation. Hydrogen quantitation and correct depth analysis require knowledge of the elementary composition (besides hydrogen) and mass density of the target material. Especially in combination with ultra-high vacuum methods for in-situ target preparation and characterization, (1)H((15)N,αγ)(12)C NRA is ideally suited for hydrogen analysis at atomically controlled surfaces and nanostructured interfaces. We exemplarily demonstrate here the application of (15)N NRA at the MALT Tandem accelerator facility of the University of Tokyo to (1) quantitatively measure the surface coverage and the bulk concentration of hydrogen in the near-surface region of a H2 exposed Pd(110) single crystal, and (2) to determine the depth location and layer density of hydrogen near the interfaces of thin SiO2 films on Si(100).

  19. Determination of the concentration profile and homogeneity of antioxidants and degradation products in a cross-linked polyethylene type A (PEXa) pipe

    DEFF Research Database (Denmark)

    Denberg, Martin; Mosbæk, Hans; Hassager, Ole

    2009-01-01

    , the concentration profile was measured at four different places on a 100 m PEXa pipe. A two-way ANOVA analysis showed that the composition of Irganox (R) 1076 was homogenous in the radial direction and heterogeneous in the longitudinal direction. Two degradation products of antioxidants were detected, 2,6-di...

  20. Effects of forage type, forage to concentrate ratio, and crushed linseed supplementation on milk fatty acid profile in lactating dairy cows

    NARCIS (Netherlands)

    Sterk, A.R.; Johansson, B.E.O.; Taweel, H.Z.H.; Murphy, M.; Vuuren, van A.M.; Hendriks, W.H.; Dijkstra, J.

    2011-01-01

    The effects of an increasing proportion of crushed linseed (CL) in combination with varying forage type (grass or corn silage) and forage to concentrate ratio (F:C), and their interactions on milk fatty acid (FA) profile of high-producing dairy cows was studied using a 3-factor Box-Behnken design.

  1. A retrospective analysis of nickel exposure data at a South African base metal refinery.

    Science.gov (United States)

    Young, Monica M; Van Der Merwe, Cornelius J; Linde, Stefan J L; Du Plessis, Johan L

    2018-03-01

    This study aimed to analyze historical soluble nickel exposure data from a South African base metal refinery and to identify trends in the soluble nickel exposure from 1981 until 2014 in the electrowinning department. Exposure data were presented in an exposure matrix, which described exposure profiles for both area and personal exposures inside two tankhouses. Exposure data were standardized by converting total nickel aerosol concentrations to inhalable nickel concentrations (correction factor 3.0). One-way analyses of variances (ANOVA) were conducted to identify significant differences in log-transformed area and personal exposures from 1982 until 2014, and the trends were assessed with linear regression. Differences were evaluated in area exposure between sections inside the tankhouses, i.e., East, West, and Center bays and in personal exposure between occupations, i.e., cell workers, crane drivers, and supervisors. Area exposure in Tankhouse 1 declined significantly (p ≤ 0.0001) between 1982 and 1986 with a factor of 29. However, after 1986 no significant downward trend in area exposure was evident in Tankhouse 1. Personal exposures in Tankhouse 1 significantly (p ≤ 0.0001) decreased with a factor of three between 1991 and 2014. No significant trends were evident in area and personal exposure in Tankhouse 2. Downward exposure trends were evident in Tankhouse 1 and may be ascribed to the implementation of various control measures and process changes, e.g., increasing polypropylene bead load. Limited data were available for Tankhouse 2, therefore, no trend in exposure could be established. Retrospective analyses may be used to identify trends and anomalies in exposure which might not have been identified during daily exposure monitoring.

  2. Influence of supplemental vitamin C on postmortem protein degradation and fatty acid profiles of the longissimus thoracis of steers fed varying concentrations of dietary sulfur.

    Science.gov (United States)

    Pogge, Danielle J; Lonergan, Steven M; Hansen, Stephanie L

    2014-02-01

    The objective was to examine the effects of supplemental vitamin C (VC) on postmortem protein degradation and fatty acid profiles of cattle receiving varying concentrations of dietary sulfur (S). A longissimus muscle was collected from 120 Angus-cross steers assigned to a 3 × 2 factorial, evaluating three concentrations of dietary S (0.22, 0.34, and 0.55%) and two concentrations of supplemental VC (0 or 10 g h(-1)d(-1)). Increasing dietary S and VC supplementation (Pdegradation (P = 0.07) and protein carbonylation (Pdegradation. © 2013.

  3. Effects of elevated atmospheric CO2 concentration and temperature on the soil profile methane distribution and diffusion in rice-wheat rotation system.

    Science.gov (United States)

    Yang, Bo; Chen, Zhaozhi; Zhang, Man; Zhang, Heng; Zhang, Xuhui; Pan, Genxing; Zou, Jianwen; Xiong, Zhengqin

    2015-06-01

    The aim of this experiment was to determine the impacts of climate change on soil profile concentrations and diffusion effluxes of methane in a rice-wheat annual rotation ecosystem in Southeastern China. We initiated a field experiment with four treatments: ambient conditions (CKs), CO2 concentration elevated to ~500 μmol/mol (FACE), temperature elevated by ca. 2°C (T) and combined elevation of CO2 concentration and temperature (FACE+T). A multilevel sampling probe was designed to collect the soil gas at four different depths, namely, 7 cm, 15 cm, 30 cm and 50 cm. Methane concentrations were higher during the rice season and decreased with depth, while lower during the wheat season and increased with depth. Compared to CK, mean methane concentration was increased by 42%, 57% and 71% under the FACE, FACE+T and T treatments, respectively, at the 7 cm depth during the rice season (pCO2 concentration and temperature could significantly increase soil profile methane concentrations and their effluxes from a rice-wheat field annual rotation ecosystem (p<0.05). Copyright © 2015. Published by Elsevier B.V.

  4. 1.6 μm DIAL Measurement and Back Trajectory Analysis of CO2 Concentration Profiles in the Lower-Atmosphere

    Science.gov (United States)

    Shibata, Y.; Nagasawa, C.; Abo, M.

    2016-12-01

    Carbon dioxide (CO2) is the primary greenhouse gas emitted through human activities. In addition to the ground level CO2 network, vertical CO2 concentration profiles also play an important role for the estimation of the carbon budget and global warming in the inversion method. Especially, for the detailed analysis of forest carbon dynamics and CO2 fluxes of urban area, vertical CO2 concentration profiles with high spatial and temporal resolution in the lower atmosphere have been conducted by a differential absorption lidar (DIAL). We have observed several vertical profiles of CO2 concentrations for nighttime and daytime from 0.25 to 2.5 km altitude with range resolution of 300 m and integration time of 1 hour. In order to extract information on the origin of the CO2 masses, one day back trajectories were calculated by using a three dimensional (3-D) atmospheric transport model. In many cases, CO2 low concentration layers of over 1.5km altitude were flown by westerly winds from the forest. In another case, high concentration layers of CO2 were flown from the urban areas. As the spectra of absorption lines of any molecules are influenced basically by the temperature in the atmosphere, laser beams of three wavelengths around a CO2 absorption spectrum are transmitted alternately to the atmosphere for simultaneous measurements of CO2 concentration and temperature profiles. Moreover, a few processing algorithms of CO2-DIAL are also performed for improvement of measurement accuracy. For computation of trajectories and drawing their figures, the JRA-25 data provided by the cooperative research project for the JRA-25 long-term reanalysis of the Japan Meteorological Agency (JMA) and the Central Research Institute of Electric Power Industry (CRIEPI) and the NIPR trajectory model (Tomikawa and Sato, 2005; http://firp-nitram.nipr.ac.jp) were used. This work was financially supported by the System Development Program for Advanced Measurement and Analysis of the Japan Science and

  5. Determination of nickel-63

    International Nuclear Information System (INIS)

    Poletiko, C.

    1988-01-01

    The research of activation products in the environment is often centered on cobalt-60 or other gamma emitters, since pure beta emitters require time consuming separations to be counted. However, some beta emitters must be checked because they have a build up in the environment, leading to potential hazards. Among these nuclides, there is nickel-63 which is a pure, soft beta emitter (67 keV) with a long half-life (100 years). A chemical separation, providing good results, was developed. Such a separation is based upon nickel carrier addition in the sample than DMG complex formation and isolation; after elimination of solvent. DMG complex is destroyed. Chemical yield is determined by flame atomic absorption measurement and nickel-63 counted by liquid scintillation. The described procedure allows the determination of low-level activities in different samples (soils, effluents, etc.). Detection limits are close to 0.1 Bq per sample

  6. REPORT FOR COMMERCIAL GRADE NICKEL CHARACTERIZATION AND BENCHMARKING

    Energy Technology Data Exchange (ETDEWEB)

    None

    2012-12-20

    Oak Ridge Associated Universities (ORAU), under the Oak Ridge Institute for Science and Education (ORISE) contract, has completed the collection, sample analysis, and review of analytical results to benchmark the concentrations of gross alpha-emitting radionuclides, gross beta-emitting radionuclides, and technetium-99 in commercial grade nickel. This report presents methods, change management, observations, and statistical analysis of materials procured from sellers representing nine countries on four continents. The data suggest there is a low probability of detecting alpha- and beta-emitting radionuclides in commercial nickel. Technetium-99 was not detected in any samples, thus suggesting it is not present in commercial nickel.

  7. Considerations for automated machine learning in clinical metabolic profiling: Altered homocysteine plasma concentration associated with metformin exposure.

    Science.gov (United States)

    Orlenko, Alena; Moore, Jason H; Orzechowski, Patryk; Olson, Randal S; Cairns, Junmei; Caraballo, Pedro J; Weinshilboum, Richard M; Wang, Liewei; Breitenstein, Matthew K

    2018-01-01

    With the maturation of metabolomics science and proliferation of biobanks, clinical metabolic profiling is an increasingly opportunistic frontier for advancing translational clinical research. Automated Machine Learning (AutoML) approaches provide exciting opportunity to guide feature selection in agnostic metabolic profiling endeavors, where potentially thousands of independent data points must be evaluated. In previous research, AutoML using high-dimensional data of varying types has been demonstrably robust, outperforming traditional approaches. However, considerations for application in clinical metabolic profiling remain to be evaluated. Particularly, regarding the robustness of AutoML to identify and adjust for common clinical confounders. In this study, we present a focused case study regarding AutoML considerations for using the Tree-Based Optimization Tool (TPOT) in metabolic profiling of exposure to metformin in a biobank cohort. First, we propose a tandem rank-accuracy measure to guide agnostic feature selection and corresponding threshold determination in clinical metabolic profiling endeavors. Second, while AutoML, using default parameters, demonstrated potential to lack sensitivity to low-effect confounding clinical covariates, we demonstrated residual training and adjustment of metabolite features as an easily applicable approach to ensure AutoML adjustment for potential confounding characteristics. Finally, we present increased homocysteine with long-term exposure to metformin as a potentially novel, non-replicated metabolite association suggested by TPOT; an association not identified in parallel clinical metabolic profiling endeavors. While warranting independent replication, our tandem rank-accuracy measure suggests homocysteine to be the metabolite feature with largest effect, and corresponding priority for further translational clinical research. Residual training and adjustment for a potential confounding effect by BMI only slightly modified

  8. Mechanical and wear properties of pre-alloyed molybdenum P/M steels with nickel addition

    Directory of Open Access Journals (Sweden)

    Yamanoglu R.

    2012-01-01

    Full Text Available The aim of this study is to understand the effect of nickel addition on mechanical and wear properties of molybdenum and copper alloyed P/M steel. Specimens with three different nickel contents were pressed under 400 MPa and sintered at 1120ºC for 30 minutes then rapidly cooled. Microstructures and mechanical properties (bending strength, hardness and wear properties of the sintered specimens were investigated in detail. Metallographical investigations showed that the microstructures of consolidated specimens consist of tempered martensite, bainite, retained austenite and pores. It is also reported that the amount of pores varies depending on the nickel concentration of the alloys. Hardness of the alloys increases with increasing nickel content. Specimens containing 2% nickel showed minimum pore quantity and maximum wear resistance. The wear mechanism changed from abrasive wear at low nickel content to adhesive wear at higher nickel content.

  9. Engineered Nickel Oxide Nanoparticle Causes Substantial Physicochemical Perturbation in Plants

    Directory of Open Access Journals (Sweden)

    Indrani Manna

    2017-11-01

    Full Text Available Concentration of engineered nickel oxide nanoparticle (NiO-NP in nature is on the rise, owing to large scale industrial uses, which have accreted the scope of its exposure to plants, the primary producers of the ecosystem. Though an essential micronutrient for the animal system, supported by numerous studies confirming its toxicity at higher dosages, nickel oxide is graded as a human carcinogen by WHO. A few studies do depict toxicity and bioaccumulation of nickel in plants; however, interaction of NiO-NP with plants is not well-elucidated. It is known that exposure to NiO-NP can incite stress response, leading to cytotoxicity and growth retardation in some plants, but a defined work on the intricate physicochemical cellular responses and genotoxic challenges is wanting. The present study was planned to explore cytotoxicity of NiO-NP in the model plant, Allium cepa L., its internalization in the tissue and concomitant furore created in the antioxidant enzyme system of the plant. The prospect of the NiO-NP causing genotoxicity was also investigated. Detailed assessments biochemical profiles and genotoxicity potential of NiO-NP on A. cepa L. was performed and extended to four of its closest economically important relatives, Allium sativum L., Allium schoenoprasum L., Allium porrum L., and Allium fistulosum L. Growing root tips were treated with seven different concentrations of NiO-NP suspension (10–500 mg L−1, with deionised distilled water as negative control and 0.4 mM EMS solution as positive control. Study of genotoxic endpoints, like, mitotic indices (MI, chromosomal aberrations (CAs, and chromosome breaks confirmed NiO-NP induced genotoxicity in plants, even at a very low dose (10 mg L−1. That NiO-NP also perturbs biochemical homeostasis, disrupting normal physiology of the cell, was confirmed through changes in state of lipid peroxidation malonaldehyde (MDA, as well as, in oxidation marker enzymes, like catalase (CAT, super oxide

  10. Chromium, Nickel and Zinc Levels from Canned and Non-Canned ...

    African Journals Online (AJOL)

    Heavy metals (Chromium, Nickel and Zinc) were determined from both canned and non-canned beverages sold in Samaru, Zaria, Kaduna State, Nigeria. Concentration of Chromium was found to range from 0.528 - 1.509mg/L for canned and 0.176 - 1.358mg/L for non-canned beverages, Nickel concentration was found to ...

  11. The GENIALL process for generation of nickel-iron alloys from nickel ores or mattes

    International Nuclear Information System (INIS)

    Diaz, G.; Frias, C.; Palma, J.

    2001-01-01

    A new process, called GENIALL (acronym of Generation of Nickel Alloys), for nickel recovery as ferronickel alloys from ores or mattes without previous smelting is presented in this paper. Its core technology is a new electrolytic concept, the ROSEL cell, for electrowinning of nickel-iron alloys from concentrated chloride solutions. In the GENIALL Process the substitution of iron-based solid wastes as jarosite, goethite or hematite, by saleable ferronickel plates provides both economic and environmental attractiveness. Another advantage is that no associated sulfuric acid plant is required. The process starts with leaching of the raw material (ores or mattes) with a solution of ferric chloride. The leachate liquor is purified by conventional methods like cementation or solvent extraction, to remove impurities or separate by-products like copper and cobalt. The purified solution, that contains a mixture of ferrous and nickel chlorides is fed to the cathodic compartment of the electrowinning cell, where nickel and ferrous ions are reduced together to form an alloy. Simultaneously, ferrous chloride is oxidized to ferric chloride in the anodic compartment, from where it is recycled to the leaching stage. The new electrolytic equipment has been developed and scaled up from laboratory to pilot prototypes with commercial size electrodes of 1 m 2 . Process operating conditions have been established in continuous runs at bench and pilot plant scale. The technology has shown a remarkable capacity to produce nickel-iron alloys of a wide range of compositions, from 10% to 80% nickel, just by adjusting the operating parameters. This emerging technology could be implemented in many processes in which iron and other non-ferrous metals are harmful impurities to be removed, or valuable metals to be recovered as a marketable iron alloy. Other potential applications of this technology are regeneration of spent etching liquors, and iron removal from aqueous effluents. (author)

  12. Nickel silicide formation in silicon implanted nickel

    Science.gov (United States)

    Rao, Z.; Williams, J. S.; Pogany, A. P.; Sood, D. K.; Collins, G. A.

    1995-04-01

    Nickel silicide formation during the annealing of very high dose (≥4.5×1017 ions/cm2) Si implanted Ni has been investigated, using ion beam analytical techniques, electron microscopy, and x-ray diffraction analysis. An initial amorphous Si-Ni alloy, formed as a result of high dose ion implantation, first crystallized to Ni2Si upon annealing in the temperature region of 200-300 °C. This was followed by the formation of Ni5Si2 in the temperature region of 300-400 °C and then by Ni3Si at 400-600 °C. The Ni3Si layer was found to have an epitaxial relationship with the substrate Ni, which was determined as Ni3Si∥Ni and Ni3Si∥Ni for Ni(100) samples. The minimum channeling yield in the 2 MeV He Rutherford backscattering and channeling spectra of this epitaxial layer improved with higher annealing temperatures up to 600 °C, and reached a best value measured at about 8%. However, the epitaxial Ni3Si dissolved after long time annealing at 600 °C or annealing at higher temperatures to liberate soluble Si into the Ni substrate. The epitaxy is attributed to the excellent lattice match between the Ni3Si and the Ni. The annealing behavior follows the predictions of the Ni-Si phase diagram for this nickel-rich binary system.

  13. Alloys of nickel-iron and nickel-silicon do not swell under fast neutron irradiation

    International Nuclear Information System (INIS)

    Silvestre, G.; Silvent, A.; Regnard, C.; Sainfort, G.

    1975-01-01

    This research is concerned with the effect of fast-neutron irradiation on the swelling of nickel and nickel alloys. Ni-Fe (0-60at%Fe) and Ni-Si (0-8at%Si) were studied, and the fluences were in the range 10 20 -4.3x10 22 n/cm 2 . In dilute alloys, the added elements are dissolved and reduce swelling, silicon being particularly effective. In more concentrated alloys, irradiation of Ni-Fe and Ni-Si alloys brings about the formation of plate-shaped precipitates of Ni 3 X and these alloys do not swell. (Auth.)

  14. The cost of nickel allergy

    DEFF Research Database (Denmark)

    Hamann, Carsten R; Hamann, Dathan; Hamann, Curtis

    2013-01-01

    %), followed by aluminium-bronze (62, 17%). In total, 239 denominations released nickel (28%). Coins from Bolivia, Brazil and Costa Rica did not release nickel. Fewer than one-third of the denominations or issues from China, India, the euro area and Indonesia released nickel. In the United States, the Russian...... Federation, Japan, and Mexico, one-third or more of the denominations released nickel. Conclusions. This worldwide selection of circulating coins covered countries with 75% of the world population, and shows that the majority of the world population lives in countries where coins release nickel. Pertinently...

  15. Nickel, palladium and rhodium induced IFN-gamma and IL-10 production as assessed by in vitro ELISpot-analysis in contact dermatitis patients

    Directory of Open Access Journals (Sweden)

    Ensoli Fabrizio

    2008-05-01

    Full Text Available Abstract Background Recent attempts to diminish nickel use in most industrial products have led to an increasing utilization of alternative metal compounds for destinations such as the alloys used in orthopaedics, jewellery and dentistry. The present study was undertaken with the aim to evaluate the potential for an allergic response to nickel, palladium and rhodium on the basis of antigen-specific induction of inflammatory/regulatory cytokines, and to characterize, according to the cytokine profiles, the nature of simultaneous positive patch tests elicited in vivo. Peripheral blood mononuclear cells (PBMC from 40 patients with different patch test results were kept in short term cultures in the presence of optimized concentrations of NiSO4 × 6H2O, PdCl2 and Rh(CH3COO2. The production of IFN-γ and IL-10 elicited by metal compounds were analyzed by the ELISpot assay. Results We found a specific IFN-γ response by PBMC upon in vitro stimulation with nickel or palladium in well recognized allergic individuals. All controls with a negative patch test to a metal salt showed an in vitro IL-10 response and not IFN-γ production when challenged with the same compound. Interestingly, all subjects with positive patch test to both nickel and palladium (group 3 showed an in vitro response characterized by the release of IFN-γ after nickel stimulation and production of IL-10 in response to palladium. Conclusion These results strongly suggest that the different cytokine profiles elicited in vitro reflect different immune responses which may lead to the control of the allergic responses or to symptomatic allergic contact dermatitis. The development of sensitive and specific in vitro assays based on the determination of the cytokine profiles in response to contact allergens may have important diagnostic and prognostic implications and may prove extremely useful in complementing the diagnostic limits of traditional patch testing.

  16. Nickel, palladium and rhodium induced IFN-gamma and IL-10 production as assessed by in vitro ELISpot-analysis in contact dermatitis patients

    Science.gov (United States)

    Bordignon, Valentina; Palamara, Francesca; Cordiali-Fei, Paola; Vento, Antonella; Aiello, Arianna; Picardo, Mauro; Ensoli, Fabrizio; Cristaudo, Antonio

    2008-01-01

    Background Recent attempts to diminish nickel use in most industrial products have led to an increasing utilization of alternative metal compounds for destinations such as the alloys used in orthopaedics, jewellery and dentistry. The present study was undertaken with the aim to evaluate the potential for an allergic response to nickel, palladium and rhodium on the basis of antigen-specific induction of inflammatory/regulatory cytokines, and to characterize, according to the cytokine profiles, the nature of simultaneous positive patch tests elicited in vivo. Peripheral blood mononuclear cells (PBMC) from 40 patients with different patch test results were kept in short term cultures in the presence of optimized concentrations of NiSO4 × 6H2O, PdCl2 and Rh(CH3COO)2. The production of IFN-γ and IL-10 elicited by metal compounds were analyzed by the ELISpot assay. Results We found a specific IFN-γ response by PBMC upon in vitro stimulation with nickel or palladium in well recognized allergic individuals. All controls with a negative patch test to a metal salt showed an in vitro IL-10 response and not IFN-γ production when challenged with the same compound. Interestingly, all subjects with positive patch test to both nickel and palladium (group 3) showed an in vitro response characterized by the release of IFN-γ after nickel stimulation and production of IL-10 in response to palladium. Conclusion These results strongly suggest that the different cytokine profiles elicited in vitro reflect different immune responses which may lead to the control of the allergic responses or to symptomatic allergic contact dermatitis. The development of sensitive and specific in vitro assays based on the determination of the cytokine profiles in response to contact allergens may have important diagnostic and prognostic implications and may prove extremely useful in complementing the diagnostic limits of traditional patch testing. PMID:18482439

  17. Nickel in tap water

    DEFF Research Database (Denmark)

    Andersen, Klaus Ejner; Nielsen, G D; Flyvholm, Morten

    1983-01-01

    Nickel analyses of tap water from several sources in Copenhagen gave up to 490 X 10(-6) g X 1(-1) in the first 250 ml portions. Hot water gave higher values than cold water. After flushing for 5 min, low values were found. Considerable variation from time to time and from tap to tap was found...

  18. cobalt (ii), nickel (ii)

    African Journals Online (AJOL)

    DR. AMINU

    Department of Chemistry Bayero University, P. M. B. 3011, Kano, Nigeria. E-mail: hnuhu2000@yahoo.com. ABSTRACT. The manganese (II), cobalt (II), nickel (II) and .... water and common organic solvents, but are readily soluble in acetone. The molar conductance measurement [Table 3] of the complex compounds in.

  19. EPIDEMIOLOGICAL AND PATHOGENETIC ASPECTS OF NICKEL POISONING

    OpenAIRE

    Vladmila Bojanic; Vladimir Ilic; Biljana Jovic

    2007-01-01

    Nickel is widely distributed in the environment. High consumption of nickel containing products inevitably leads to environmental pollution by nickel and its derivatives at all stages of production, utilization, and disposal.Human exposure to nickel occurs primarily via inhalation and ingestion and is particularly high among nickel metallurgy workers. In addition, implantation of nickel-containing endoprostheses and iatrogenic administration of nickel-contaminated medica-tions leads to signif...

  20. Chemical weathering of a marine terrace chronosequence, Santa Cruz, California I: Interpreting rates and controls based on soil concentration-depth profiles

    Science.gov (United States)

    White, A.F.; Schulz, M.S.; Vivit, D.V.; Blum, A.E.; Stonestrom, David A.; Anderson, S.P.

    2008-01-01

    The spatial and temporal changes in element and mineral concentrations in regolith profiles in a chronosequence developed on marine terraces along coastal California are interpreted in terms of chemical weathering rates and processes. In regoliths up to 15 m deep and 226 kyrs old, quartz-normalized mass transfer coefficients indicate non-stoichiometric preferential release of Sr > Ca > Na from plagioclase along with lesser amounts of K, Rb and Ba derived from K-feldspar. Smectite weathering results in the loss of Mg and concurrent incorporation of Al and Fe into secondary kaolinite and Fe-oxides in shallow argillic horizons. Elemental losses from weathering of the Santa Cruz terraces fall within the range of those for other marine terraces along the Pacific Coast of North America. Residual amounts of plagioclase and K-feldspar decrease with terrace depth and increasing age. The gradient of the weathering profile bs is defined by the ratio of the weathering rate, R to the velocity at which the profile penetrates into the protolith. A spreadsheet calculator further refines profile geometries, demonstrating that the non-linear regions at low residual feldspar concentrations at shallow depth are dominated by exponential changes in mineral surface-to-volume ratios and at high residual feldspar concentrations, at greater depth, by the approach to thermodynamic saturation. These parameters are of secondary importance to the fluid flux qh, which in thermodynamically saturated pore water, controls the weathering velocity and mineral losses from the profiles. Long-term fluid fluxes required to reproduce the feldspar weathering profiles are in agreement with contemporary values based on solute Cl balances (qh = 0.025-0.17 m yr-1). During saturation-controlled and solute-limited weathering, the greater loss of plagioclase relative to K-feldspar is dependent on the large difference in their respective solubilities instead of the small difference between their respective

  1. Preparation of fine Ni powders from nickel hydrazine complex

    International Nuclear Information System (INIS)

    Park, Jung Woo; Chae, Eun H.; Kim, Sang H.; Lee, Jong Ho; Kim, Jeong Wook; Yoon, Seon Mi; Choi, Jae-Young

    2006-01-01

    Fine nickel powders with narrow size distribution have been prepared from the reduction of nickel hydrazine complexes in aqueous solution. The pure nickel hydrazine complexes, [Ni(N 2 H 4 ) 3 ]Cl 2 were prepared with the molar ratio of N 2 H 4 /Ni 2+ = 4.5, while a mixture of complexes, such as Ni(N 2 H 4 ) 2 Cl 2 , [Ni(N 2 H 4 ) 3 ]Cl 2 , and [Ni(NH 3 ) 6 ]Cl 2 were formed with N 2 H 4 /Ni 2+ 2+ to metallic Ni powder proceeded via the formation of nickel hydroxide which was reduced by hydrazine liberated from the ligand exchange reaction between the nickel hydrazine complex and NaOH. The standard deviation of the particle size decreased with the decreasing molar concentration of nickel hydrazine complex while the mean particle size increased. As the amount of hydrazine increased, the surface roughness of the particles was improved significantly due to the catalytic decomposition of the excess hydrazine at the surface of the nickel particle. It was found that average particle size could be controlled from 150 to 380 nm by adjusting the reaction molar ratio and temperature

  2. A passive air sampler for characterizing the vertical concentration profile of gaseous phase polycyclic aromatic hydrocarbons in near soil surface air

    International Nuclear Information System (INIS)

    Zhang Yuzhong; Deng Shuxing; Liu Yanan; Shen Guofeng; Li Xiqing; Cao Jun; Wang Xilong; Reid, Brian; Tao Shu

    2011-01-01

    Air-soil exchange is an important process governing the fate of polycyclic aromatic hydrocarbons (PAHs). A novel passive air sampler was designed and tested for measuring the vertical concentration profile of 4 low molecular weight PAHs in gaseous phase (PAH LMW4 ) in near soil surface air. Air at various heights from 5 to 520 mm above the ground was sampled by polyurethane foam disks held in down-faced cartridges. The samplers were tested at three sites: A: an extremely contaminated site, B: a site near A, and C: a background site on a university campus. Vertical concentration gradients were revealed for PAH LMW4 within a thin layer close to soil surface at the three sites. PAH concentrations either decreased (Site A) or increased (Sites B and C) with height, suggesting either deposition to or evaporation from soils. The sampler is a useful tool for investigating air-soil exchange of gaseous phase semi-volatile organic chemicals. - Research highlights: → Design, field test and calibration of the novel passive air sampler, PAS-V-I. → Vertical concentration gradients of PAH LMW4 within a thin layer close to soil. → Comparison of results between PAS-V-I measurement and fugacity approach. → Potential application of PAS-V-I and further modifications. - A novel passive sampling device was developed and tested for measuring vertical concentration profile of gaseous phase polycyclic aromatic hydrocarbons in near soil surface air.

  3. Environmental nickel exposure from oil refinery emissions: a case study in Ecuador.

    Science.gov (United States)

    Harari, Raúl; Harari, Florencia; Forastiere, Francesco

    2016-01-01

    Nickel is a strong skin and respiratory sensitizer and a recognized carcinogen. Oil refineries are important sources of atmospheric emissions of toxic pollutants, including nickel. Populations residing close to oil refineries are at potential risk. The aim of this study was to evaluate the exposure to nickel in a population living close to the largest oil refinery in Ecuador, located in the city of Esmeraldas. We recruited 47 workers from the oil refinery as well as 195 students from 4 different schools close to the plant and 94 students from another school 25 km far from the industry. Urinary nickel concentrations were used to assess the exposure to nickel. Students from the school next to the oil refinery showed the highest urinary nickel concentrations while workers from the refinery showed the lowest concentrations. Median nickel concentrations were > 2µg/L in all study groups. The populations living close to the oil refineries are potentially exposed to nickel from atmospheric emissions. Further studies investigating nickel-related health effects in the population residing close to the refinery of Esmeralda are needed.

  4. 2-Mercaptobenzimidazole, 2-Mercaptobenzothiazole, and Thioglycolic Acid in an Electroless Nickel-Plating Bath

    Directory of Open Access Journals (Sweden)

    Ahmet Ozan Gezerman

    2015-01-01

    Full Text Available The use of three different materials, 2-mercaptobenzimidazole, 2-mercaptobenzothiazole, and thioglycolic acid, was investigated to improve the performance of electroless nickel-plating baths. By changing the concentrations of these materials, sample plates were coated. Optical microscope images were obtained by selecting representative coated plates. From the results of the investigations, the effects of these materials on electroless nickel plating were observed, and the most appropriate amounts of these materials for nickel plating were determined. Moreover, the nickel plating speed observed with the bath solution containing 2-mercaptobenzimidazole, 2-mercaptobenzothiazole, and thioglycolic acid is higher than that in the case of traditional electroless plating baths, but the nickel consumption amount in the former case is lower. In order to minimize the waste water generated from electroless nickel-plating baths, we determined the lowest amounts of the chemicals that can be used for the concentrations reported in the literature.

  5. 222Rn flux and soil air concentration profiles in West-Germany. Soil 222Rn as tracer for gas transport in the unsaturated soil zone

    International Nuclear Information System (INIS)

    Doerr, H.; Muennich, K.O.

    1990-01-01

    Measurements of the 222 Rn activity concentration profile in the soil and the 222 Rn flux in West-Germany are presented. The spatial pattern of the 222 Rn flux depends more on soil type than on the 226 Ra activity of the soil material. The average 222 Rn flux from sandy soils is 1000-2000 dpm m -2 h -1 and 4000-6000 dpm m -2 h -1 froam loamy and clayey soils. Weekly 222 Rn flux measurements during a period of 1 year at a sandy site show no significant temporal variations. At a clayey site, the 222 Rn flux tends to be higher in summer than in winter. The permeability coefficient P Rn , obtained from simultaneous 222 Rn flux and concentration profile measurements in various soils, can be expressed as a function of the soil parameters total porosity ε 0 , soil moisture F, tortuosity k and the molecular diffusion coefficient D 0 of 222 Rn in air: P = D 0 ((ε 0 -F)/k-const.). The flux of any other gas into or out of the soil can thus be calculated from its measured concentration profile in the soil and from the 222 Rn permeability coefficient, replacing the molecular diffusion coefficient of 222 Rn by that of the specific gas under consideration. As an example, this method of flux determination is demonstrated for the soil CO 2 flux to the atmosphere and for the flux of atmospheric CH 4 into the soil. (author) 14 refs

  6. Selective recovery of nickel over iron from a nickel-iron solution using microbial sulfate reduction in a gas-lift bioreactor

    NARCIS (Netherlands)

    Bijmans, M.F.M.; Helvoort, van P.J.; Dar, S.; Dopson, M.; Lens, P.N.L.; Buisman, C.J.N.

    2009-01-01

    Process streams with high concentrations of metals and sulfate are characteristic for the mining and metallurgical industries. This study aims to selectively recover nickel from a nickel-iron-containing solution at pH 5.0 using a single stage bioreactor that simultaneously combines low pH sulfate

  7. Parallel 50 ampere hour nickel cadmium battery performance in the Modular Power Subsystems (MPS)

    Science.gov (United States)

    Webb, D. A.

    1980-01-01

    The thermal performance of 50-ampere-hour, nickel cadmium batteries for use in a modular spacecraft is examined in near-Earth orbit simulation. Battery voltage and temperature profiles for temperature extreme cycles are given and discussed.

  8. Density profile and cholesterol concentration of serum lipoproteins in experimental animals and human subjects on hypercholesterolaemic diets

    NARCIS (Netherlands)

    Beynen, A.C.; Terpstra, A.H.M.

    1984-01-01

    1. 1. The density profile of Sudan black stained serum lipoproteins was studied in human subjects and various animal species on diets supplemented with cholesterol. 2. 2. In the animals studied (rabbits, calves, mice, chickens, rats and guinea-pigs), the feeding of cholesterol resulted in an

  9. Studies on influence of zinc immersion and fluoride on nickel electroplating on magnesium alloy AZ91D

    International Nuclear Information System (INIS)

    Zhang Ziping; Yu Gang; Ouyang Yuejun; He Xiaomei; Hu Bonian; Zhang Jun; Wu Zhenjun

    2009-01-01

    The effect of zinc immersion and the role of fluoride in nickel plating bath were mainly investigated in nickel electroplating on magnesium alloy AZ91D. The state of zinc immersion, the composition of zinc film and the role of fluoride in nickel plating bath were explored from the curves of open circuit potential (OCP) and potentiodynamic polarization, the images of scanning electron microscopy (SEM) and the patterns of energy dispersive X-ray (EDX). Results show that the optimum zinc film mixing small amount of Mg(OH) 2 and MgF 2 is obtained by zinc immersion for 30-90 s. The corrosion potential of magnesium alloy substrate attached zinc film will be increased in nickel plating bath and the quantity of MgF 2 sandwiched between magnesium alloy substrate and nickel coating will be reduced, which contributed to produce nickel coating with good performance. Fluoride in nickel plating bath serves as an activator of nickel anodic dissolution and corrosion inhibitor of magnesium alloy substrate. 1.0-1.5 mol dm -3 of F - is the optimum concentration range for dissolving nickel anode and protecting magnesium alloy substrate from over-corrosion in nickel plating bath. The nickel coating with good adhesion and high corrosion resistance on magnesium alloy AZ91D is obtained by the developed process of nickel electroplating. This nickel layer can be used as the rendering coating for further plating on magnesium alloys.

  10. Controlled synthesis of size-tunable nickel and nickel oxide nanoparticles using water-in-oil microemulsions

    International Nuclear Information System (INIS)

    Kumar, Ajeet; Saxena, Amit; Shankar, Ravi; Mozumdar, Subho; De, Arnab

    2013-01-01

    Industrial demands have generated a growing need to synthesize pure metal and metal–oxide nanoparticles of a desired size. We report a novel and convenient method for the synthesis of spherical, size tunable, well dispersed, stable nickel and nickel oxide nanoparticles by reduction of nickel nitrate at room temperature in a TX-100/n-hexanol/cyclohexane/water system by a reverse microemulsion route. We determined that reduction with alkaline sodium borohydrate in nitrogen atmosphere leads to the formation of nickel nanoparticles, while the use of hydrazine hydrate in aerobic conditions leads to the formation of nickel oxide nanoparticles. The influence of several reaction parameters on the size of nickel and nickel oxide nanoparticles were evaluated in detail. It was found that the size can be easily controlled either by changing the molar ratio of water to surfactant or by simply altering the concentration of the reducing agent. The morphology and structure of the nanoparticles were characterized by quasi-elastic light scattering (QELS), transmission electron microscopy (TEM), x-ray diffraction (XRD), electron diffraction analysis (EDA) and energy dispersive x-ray (EDX) spectroscopy. The results show that synthesized nanoparticles are of high purity and have an average size distribution of 5–100 nm. The nanoparticles prepared by our simple methodology have been successfully used for catalyzing various chemical reactions. (paper)

  11. Toxicity of nickel in the marine calanoid copepod Acartia tonsa: Nickel chloride versus nanoparticles

    International Nuclear Information System (INIS)

    Zhou, C.; Vitiello, V.; Casals, E.; Puntes, V.F.; Iamunno, F.; Pellegrini, D.; Changwen, W.; Benvenuto, G.; Buttino, I.

    2016-01-01

    Highlights: • Acartia tonsa copepod is more sensitive to NiCl_2 than to nickel nanoparticles. • At the tested concentration egg production was not affected by both form of nickel. • Egg viability is the most sensitive end-point for both form of nickel. • Nickel dissolved in seawater increased with nanoparticle concentration. • Acartia tonsa adults were able to ingest nanoparticles. - Abstract: Nickel compounds are widely used in industries and have been massively introduced in the environment in different chemical forms. Here we report the effect of two different chemical forms of nickel, NiCl_2 and nickel nanoparticles (NiNPs), on the reproduction of the marine calanoid copepod Acartia tonsa. The behavior of nickel nanoparticles was analyzed with different techniques and with two protocols. In the “sonicated experiment” (SON) NiNP solution was sonicated while in the “non-sonicated experiment” (NON-SON) the solution was vigorously shaken by hand. Final nominal concentrations of 5, 10 and 50 mg L"−"1 and 1, 5 and 10 mg L"−"1 NiNPs were used for the acute and semichronic tests, respectively. Nanoparticle size did not change over time except for the highest concentration of 50 mg L"−"1 NiNPs, in which the diameter increased up to 843 nm after 48 h. The concentration of Ni dissolved in the water increased with NP concentration and was similar for SON and NON-SON solutions. Our results indicate that sonication does not modify toxicity for the copepod A. tonsa. Mean EC_5_0 values were similar for NON-SON (20.2 mg L"−"1) and SON experiments (22.14 mg L"−"1) in the acute test. Similarly, no differences occurred between the two different protocols in the semichronic test, with an EC_5_0 of 7.45 mg L"−"1 and 6.97 mg L"−"1 for NON-SON and SON experiments, respectively. Acute and semichronic tests, conducted exposing A. tonsa embryos to NiCl_2 concentrations from 0.025 to 0.63 mg L"−"1, showed EC_5_0 of 0.164 and 0.039 mg L"−"1, respectively

  12. Carbon deposition on nickel ferrites and nickel-magnetite surfaces

    International Nuclear Information System (INIS)

    Allen, G.C.; Jutson, J.A.

    1988-06-01

    Carbon deposition on Commercial Advanced Gas-Cooled Reactor (CAGR) fuel cladding and heat exchanger surfaces lowers heat transfer efficiency and increases fuel pin temperatures. Several types of deposit have been identified including both thin dense layers and also low density columnar deposits with filamentary or convoluted laminar structure. The low-density types are often associated with particles containing iron, nickel or manganese. To identify the role of nickel in the deposition process surfaces composed of nickel-iron spinels or metallic nickel/magnetite mixtures have been exposed to γ radiation in a gas environment simulating that in the reactor. Examination of these surfaces by Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) have shown that while metallic nickel (Ni(O)) catalyses the formation of filamentary low density carbon deposits, the presence of divalent nickel (Ni(II)) sites in spinel type oxides is associated only with dense deposits. (author)

  13. Urinary nickel: measurement of exposure by inductively coupled plasma argon emission spectrometry.

    Science.gov (United States)

    Koizumi, Chisato; Usuda, Kan; Hayashi, Satsuki; Dote, Tomotaro; Kono, Koichi

    2004-09-01

    Nickel is a rare earth metal and is widely used in modern industry. Its overexposure in human beings can provoke significant effects including lung, cardiovascular and kidney diseases. As an index of occupational exposure, urine is widely used for the monitoring of nickel concentration because it is a minimally invasive method. Recent studies have used atomic absorption spectrometry to measure nickel concentration. In this study, we introduced novel inductively coupled plasma argon emission spectrometry (ICPAES) which enables us to measure multiple elements simultaneously with smaller volume and with lower detection limits compared to conventional atomic absorption emission spectrometry, and we established the new measuring method by determining the appropriate wavelengths for nickel concentration. Furthermore, using the established new measuring method, we investigated the correlation between a single oral administration of nickel and urine elimination in rats. As a result, different concentrations of nickel standard solutions were measured by ICPAES, and among five specific wavelengths of nickel, 221.647 and 231.604 nm were chosen because they had the highest inclines of both signal to background ratio and emission intensity in simple linear regression analysis. Next, by using healthy human urine samples that had not been exposed to nickel, 231.604 nm was determined to be the most appropriate wavelength because it did not present abnormal intensity due to obstacle wavelength. Male Wistar rats received an oral administration of nickel ranging from 0.025 to 250 mg/kg, which is equivalent to 0.0015 - 15% of LD50, and during the following 24 h, urine samples were collected and the nickel concentration was measured by ICPAES. With a single oral administration of nickel, there was an increase in urine nickel concentration in a dose-dependent manner and the appropriate equation was developed. Acute renal failure was not observed in this dosage of oral nickel

  14. Concentration- and time-dependent genotoxicity profiles of isoprene monoepoxides and diepoxide, and the cross-linking potential of isoprene diepoxide in cells

    Directory of Open Access Journals (Sweden)

    Yan Li

    2014-01-01

    Full Text Available Isoprene, a possible carcinogen, is a petrochemical and a natural product being primarily produced by plants. It is biotransformed to 2-ethenyl-2-methyloxirane (IP-1,2-O and 2-(1-methylethenyloxirane (IP-3,4-O, both of which can be further metabolized to 2-methyl-2,2′-bioxirane (MBO. MBO is mutagenic, but IP-1,2-O and IP-3,4-O are not. While IP-1,2-O has been reported being genotoxic, the genotoxicity of IP-3,4-O and MBO, and the cross-linking potential of MBO have not been examined. In the present study, we used the comet assay to investigate the concentration- and time-dependent genotoxicity profiles of the three metabolites and the cross-linking potential of MBO in human hepatocyte L02 cells. For the incubation time of 1 h, all metabolites showed positive concentration-dependent profiles with a potency rank order of IP-3,4-O > MBO > IP-1,2-O. In human hepatocellular carcinoma (HepG2 and human leukemia (HL60 cells, IP-3,4-O was still more potent in inducing DNA breaks than MBO at high concentrations (>200 μM, although at low concentrations (≤200 μM IP-3,4-O exhibited slightly lower or similar potency to MBO. Interestingly, their time-dependent genotoxicity profiles (0.5–4 h in L02 cells were different from each other: IP-1,2-O and MBO (200 μM exhibited negative and positive profiles, respectively, with IP-3,4-O lying in between, namely, IP-3,4-O-caused DNA breaks did not change over the exposure time. Further experiments demonstrated that hydrolysis of IP-1,2-O contributed to the negative profile and MBO induced cross-links at high concentrations and long incubation times. Collectively, the results suggested that IP-3,4-O might play a significant role in the toxicity of isoprene.

  15. Investigation of interdiffusion in copper-nickel bilayer thin films

    Energy Technology Data Exchange (ETDEWEB)

    Abdul-Lettif, Ahmed M. [Physics Department, College of Science, Babylon University, Hilla (Iraq)]. E-mail: abdullettif@yahoo.com

    2007-01-15

    Auger depth profiling technique and X-ray diffraction analysis have been employed to study the interdiffusion in vacuum-deposited copper-nickel bilayer thin films. An adaptation of the Whipple model was used to determine the diffusion coefficients of both nickel in copper and copper in nickel. The calculated diffusion coefficient is (2.0x10{sup -7} cm{sup 2}/s)exp(-1.0 eV/kT) for nickel in copper, and (6x10{sup -8} cm{sup 2}/s)exp(-0.98 eV/kT) for copper in nickel. The difference between the diffusion parameters obtained in the present work and those extracted by other investigators is attributed essentially to the difference in the films microstructure and to the annealing ambient. It is concluded that interdiffusion in the investigated films is described by type-B kinetics in which rapid grain-boundary diffusion is coupled to defect-enhanced diffusion into the grain interior. The present data raise a question about the effectiveness of nickel as a diffusion barrier between copper and the silicon substrate.

  16. Nickel hydrogen/nickel cadmium battery trade studies

    Science.gov (United States)

    Stadnick, S. J.

    1983-01-01

    Nickel Hydrogen cell and battery technology has matured to the point where a real choice exists between Nickel Hydrogen and Nickel Cadmium batteries for each new spacecraft application. During the past few years, a number of spacecraft programs have been evaluated at Hughes with respect to this choice, with the results being split about fifty-fifty. The following paragraphs contain criteria which were used in making the battery selection.

  17. Nickel ferrule applicators: a source of nickel exposure in children.

    Science.gov (United States)

    Jacob, Sharon E; Silverberg, Jonathan I; Rizk, Christopher; Silverberg, Nanette

    2015-01-01

    Eye makeup has been investigated for nickel content and found to have no direct association with nickel allergy and cosmetic dermatitis. However, the tools used (e.g., eyelash curlers, hairdressing scissors, hair curlers, and eye shadow and makeup applicators) may be sources. Nickel is ubiquitous and a wide range of sources have been reported, and makeup applicators (ferrules) now join the list. © 2015 Wiley Periodicals, Inc.

  18. Direct observation of solid-phase adsorbate concentration profile in powdered activated carbon particle to elucidate mechanism of high adsorption capacity on super-powdered activated carbon.

    Science.gov (United States)

    Ando, Naoya; Matsui, Yoshihiko; Matsushita, Taku; Ohno, Koichi

    2011-01-01

    Decreasing the particle size of powdered activated carbon (PAC) by pulverization increases its adsorption capacities for natural organic matter (NOM) and polystyrene sulfonate (PSS, which is used as a model adsorbate). A shell adsorption mechanism in which NOM and PSS molecules do not completely penetrate the adsorbent particle and instead preferentially adsorb near the outer surface of the particle has been proposed as an explanation for this adsorption capacity increase. In this report, we present direct evidence to support the shell adsorption mechanism. PAC particles containing adsorbed PSS were sectioned with a focused ion beam, and the solid-phase PSS concentration profiles of the particle cross-sections were directly observed by means of field emission-scanning electron microscopy/energy-dispersive X-ray spectrometry (FE-SEM/EDXS). X-ray emission from sulfur, an index of PSS concentration, was higher in the shell region than in the inner region of the particles. The X-ray emission profile observed by EDXS did not agree completely with the solid-phase PSS concentration profile predicted by shell adsorption model analysis of the PSS isotherm data, but the observed and predicted profiles were not inconsistent when the analytical errors were considered. These EDXS results provide the first direct evidence that PSS is adsorbed mainly in the vicinity of the external surface of the PAC particles, and thus the results support the proposition that the increase in NOM and PSS adsorption capacity with decreasing particle size is due to the increase in external surface area on which the molecules can be adsorbed. Copyright © 2010 Elsevier Ltd. All rights reserved.

  19. Nickel deposited on the skin-visualization by DMG test.

    Science.gov (United States)

    Julander, Anneli; Skare, Lizbet; Vahter, Marie; Lidén, Carola

    2011-03-01

    Nickel is the most common cause of contact allergy and an important risk factor for hand eczema. Visualization techniques may be powerful in showing exposures. The dimethylglyoxime (DMG) test might be used to establish skin exposure to nickel. To develop and evaluate methods for visualization of nickel on the skin by the DMG test and hand imprints. Nickel solutions at different concentrations were applied in duplicate on the hands in healthy subjects (n = 5). The DMG test and acid wipe sampling for quantification were then performed. Hand imprints were taken after manipulation of nickel-releasing tools (n = 1), and in workers performing their normal tasks (n = 7). The imprints were developed by the DMG test. The DMG test on hands gave positive results in all subjects. The lowest concentration giving rise to a colour change was set to 0.13 µg/cm(2) for DMG testing on skin. DMG test-developed imprints worked well except when hands were heavily contaminated by other particles/dust. The DMG test may be used as a simple and powerful tool for visualization of nickel on skin. DMG test-developed hand imprints may, in the future, be used for semi-quantitative or quantitative exposure assessment. © 2011 John Wiley & Sons A/S.

  20. Design and construction of the facility for neutron depth profiling in research reactor RECH-1

    International Nuclear Information System (INIS)

    Mutis P, Octavio; Navarro A, Gustavo; Henriquez A, Carlos; Pereda B, Claudio

    2002-01-01

    Here is described the experimental facility for Neutron Depth Profiling, NDP, constructed at the CCHEN laboratories, as well as some general aspects of the technique. It is also shown applications to the concentration analysis of 10 B and 6 Li as a function of depth for borophosphosilicate glass, BPSG, and for a thick sinter of 6 Li in a zinc-nickel-manganese oxide. Achieved depth resolution is comparable to that obtained in reference advanced laboratories. (author)

  1. Nickel base alloys

    International Nuclear Information System (INIS)

    Gibson, R.C.; Korenko, M.K.

    1980-01-01

    Nickel based alloy, the characteristic of which is that it mainly includes in percentages by weight: 57-63 Ni, 7-18 Cr, 10-20 Fe, 4-6 Mo, 1-2 Nb, 0.2-0.8 Si, 0.01-0.05 Zr, 1.0-2.5 Ti, 1.0-2.5 Al, 0.02-0.06 C and 0.002-0.015 B. The aim is to create new nickel-chromium alloys, hardened in a solid solution and by precipitation, that are stable, exhibit reduced swelling and resistant to plastic deformation inside the reactor. These alloys of the gamma prime type have improved mechanical strengthm swelling resistance, structural stability and welding properties compared with Inconel 625 [fr

  2. Distribution of medium-to-coarse glass beads in slurry pipe flow: evaluation of measured concentration profiles

    Czech Academy of Sciences Publication Activity Database

    Matoušek, Václav; Krupička, Jan; Pěník, Vojtěch

    2014-01-01

    Roč. 32, č. 2 (2014), s. 186-196 ISSN 0272-6351. [7th International Conference for Conveying and Handling of Particulate Solids (CHoPS). Friedrichshafen, 10.09.2013-13.09.2012] R&D Projects: GA ČR GA103/09/0383 Institutional support: RVO:67985874 Keywords : concentration distribution * high concentrated slurry * pipeline flow * slurry flow experiment Subject RIV: BK - Fluid Dynamics Impact factor: 0.523, year: 2014

  3. Polychlorinated biphenyls (PCBs) in industrial and municipal effluents: Concentrations, congener profiles, and partitioning onto particulates and organic carbon

    International Nuclear Information System (INIS)

    Balasubramani, Aparna; Howell, Nathan L.; Rifai, Hanadi S.

    2014-01-01

    Wastewater effluent samples were collected in the summer of 2009 from 16 different locations which included municipal and industrial wastewater treatment plants and petrochemical industrial outfalls in the Houston area. The effluent samples were analyzed for all 209 polychlorinated biphenyls (PCBs) congeners using high resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS) using the USEPA method 1668A. The total PCBs (∑ 209) concentration in the dissolved medium ranged from 1.01 to 8.12 ng/L and ranged from 2.03 to 31.2 ng/L in the suspended medium. Lighter PCB congeners exhibited highest concentrations in the dissolved phase whereas, in the suspended phase, heavier PCBs exhibited the highest concentrations. The PCB homolog concentrations were dominated by monochlorobiphenyls through hexachlorobiphenyls, with dichlorobiphenyls exhibiting the highest concentration amongst them at most of the effluent outfalls, in the suspended phase. Both total suspended solids (TSS) and various organic carbon fractions played an important role in the distribution of the suspended fractions of PCBs in the effluents. The log K oc values determined in the effluents suggest that effluent PCB loads might have more risk and impact than what standard partitioning models predict. - Highlights: • 209 PCB congeners were measured in 16 different municipal and industrial effluents. • PCB congener differences were elucidated for the various effluent types. • In addition to log K ow , organic carbon and TSS affect partitioning of PCBs. • High concentrations of homolog 2 maybe due to biotransformation of PCBs

  4. Effect of Theobromine Consumption on Serum Lipoprotein Profiles in Apparently Healthy Humans with Low HDL-Cholesterol Concentrations

    Directory of Open Access Journals (Sweden)

    Doris M. Jacobs

    2017-08-01

    Full Text Available Scope: Theobromine is a major active compound in cocoa with allegedly beneficial effect on high-density-lipoprotein-cholesterol (HDL-CH. We have investigated the effect of theobromine (TB consumption on the concentrations of triglyceride (TG and cholesterol (CH in various lipoprotein (LP subclasses.Methods: In a randomized, double-blind, placebo-controlled, cross-over study, 44 apparently healthy women and men (age: 60 ± 6 years, BMI: 29 ± 3 kg/m2 with low baseline HDL-CH concentrations consumed a drink supplemented with 500 mg/d theobromine for 4 weeks. TG and CH concentrations in 15 LP subclasses were predicted from diffusion-edited 1H NMR spectra of fasting serum.Results: The LP phenotype of the subjects was characterized by low CH concentrations in the large HDL particles and high TG concentrations in large VLDL and chylomicron (CM particles, which clearly differed from a LP phenotype of subjects with normal HDL-CH. TB only reduced CH concentrations in the LDL particles by 3.64 and 6.79%, but had no effect on TG and CH in any of the HDL, VLDL and CM subclasses.Conclusion: TB was not effective on HDL-CH in subjects with a LP phenotype characterized by low HDL-CH and high TG in VLDL.

  5. Effect of Theobromine Consumption on Serum Lipoprotein Profiles in Apparently Healthy Humans with Low HDL-Cholesterol Concentrations.

    Science.gov (United States)

    Jacobs, Doris M; Smolders, Lotte; Lin, Yuguang; de Roo, Niels; Trautwein, Elke A; van Duynhoven, John; Mensink, Ronald P; Plat, Jogchum; Mihaleva, Velitchka V

    2017-01-01

    Scope: Theobromine is a major active compound in cocoa with allegedly beneficial effect on high-density-lipoprotein-cholesterol (HDL-CH). We have investigated the effect of theobromine (TB) consumption on the concentrations of triglyceride (TG) and cholesterol (CH) in various lipoprotein (LP) subclasses. Methods: In a randomized, double-blind, placebo-controlled, cross-over study, 44 apparently healthy women and men (age: 60 ± 6 years, BMI: 29 ± 3 kg/m 2 ) with low baseline HDL-CH concentrations consumed a drink supplemented with 500 mg/d theobromine for 4 weeks. TG and CH concentrations in 15 LP subclasses were predicted from diffusion-edited 1 H NMR spectra of fasting serum. Results: The LP phenotype of the subjects was characterized by low CH concentrations in the large HDL particles and high TG concentrations in large VLDL and chylomicron (CM) particles, which clearly differed from a LP phenotype of subjects with normal HDL-CH. TB only reduced CH concentrations in the LDL particles by 3.64 and 6.79%, but had no effect on TG and CH in any of the HDL, VLDL and CM subclasses. Conclusion: TB was not effective on HDL-CH in subjects with a LP phenotype characterized by low HDL-CH and high TG in VLDL.

  6. Occupational exposure to nickel, uranium and thorium in a nickel mine

    International Nuclear Information System (INIS)

    Azeredo, A.M.; Lipsztein, J.L.; Dias da Cunha, K.; Lourenco, M.C.; Lipsztein, J.L.; Miekeley, N.T.

    2002-01-01

    The workers involved in mining and milling ores are exposed in the workplace to many hazardous agents that can cause a health detriment. In this work, the measurements obtained in a nickel mineral processing facility in the Brazilian Central-West are presented. One of the most important hazardous agents in this facility is the aerosol present in the air that contains nickel, uranium and thorium. The aerosol is inhaled or ingested, metabolised and deposited in the whole body or in specific organs. The surveillance of internal contamination of workers was performed by analysis of urine, fecal and hair samples. The ICP-MS (Inductively Coupled Plasma-Mass Spectrometry) method was used to analytically determine nickel, uranium and thorium in these biological samples. Additional data were obtained by the collection of air samples in the workplace. A cascade impactor with six stages was used to collect mineral dust particles with an aerodynamic diameter in the range of 0.64 to 19.4 μm. The particles impacted in each stage of the cascade impactor were analysed by PIXE (Particle Induced X ray Emission), which permits the determination of elemental mass air concentration and the MMAD (Mass Median Aerodynamic Diameter). The concentrations of nickel, uranium and thorium were determined in the aerosol samples. All the results were analysed using statistical methods and biokinetical modelling was applied to evaluate the internal contamination and to make a risk estimation. (author)

  7. Synthesis, structure characterization and catalytic activity of nickel tungstate nanoparticles

    International Nuclear Information System (INIS)

    Pourmortazavi, Seied Mahdi; Rahimi-Nasrabadi, Mehdi; Khalilian-Shalamzari, Morteza; Zahedi, Mir Mahdi; Hajimirsadeghi, Seiedeh Somayyeh; Omrani, Ismail

    2012-01-01

    Graphical abstract: NiWO 4 nanoparticles were prepared via precipitation technique. Experimental parameters of procedure were optimized statistically. Highlights: ► NiWO 4 spherical nanoparticles were synthesized via direct precipitation method. ► Taguchi robust design was used for optimization of synthesis reaction parameters. ► Composition and structural properties of NiWO 4 nanoparticles were characterized. ► EDAX, XRD, SEM, FT-IR, UV–vis and photoluminescence techniques were employed. ► Catalytic activity of the product in a cyclo-addition reaction was investigated. - Abstract: Taguchi robust design was applied to optimize experimental parameters for controllable, simple and fast synthesis of nickel tungstate nanoparticles. NiWO 4 nanoparticles were synthesized by precipitation reaction involving addition of nickel ion solution to the tungstate aqueous reagent and then formation of nickel tungstate nucleolus which are insoluble in aqueous media. Effects of various parameters such as nickel and tungstate concentrations, flow rate of reagent addition and reactor temperature on diameter of synthesized nickel tungstate nanoparticles were investigated experimentally by the aid of orthogonal array design. The results for analysis of variance (ANOVA) showed that particle size of nickel tungstate can be effectively tuned by controlling significant variables involving nickel and tungstate concentrations and flow rate; while, temperature of the reactor has a no considerable effect on the size of NiWO 4 particles. The ANOVA results proposed the optimum conditions for synthesis of nickel tungstate nanoparticles via this technique. Also, under optimum condition nanoparticles of NiWO 4 were prepared and their structure and chemical composition were characterized by means of EDAX, XRD, SEM, FT-IR spectroscopy, UV–vis spectroscopy, and photoluminescence. Finally, catalytic activity of the nanoparticles in a cycloaddition reaction was examined.

  8. Synthesis, structure characterization and catalytic activity of nickel tungstate nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Pourmortazavi, Seied Mahdi, E-mail: pourmortazavi@yahoo.com [Faculty of Material and Manufacturing Technologies, Malek Ashtar University of Technology, Tehran (Iran, Islamic Republic of); Rahimi-Nasrabadi, Mehdi, E-mail: rahiminasrabadi@gmail.com [Department of Chemistry, Imam Hossein University, Tehran (Iran, Islamic Republic of); Khalilian-Shalamzari, Morteza [Department of Chemistry, Imam Hossein University, Tehran (Iran, Islamic Republic of); Zahedi, Mir Mahdi; Hajimirsadeghi, Seiedeh Somayyeh [Islamic Azad University, Varamin Pishva Branch, Varamin (Iran, Islamic Republic of); Omrani, Ismail [Department of Chemistry, Imam Hossein University, Tehran (Iran, Islamic Republic of)

    2012-12-15

    Graphical abstract: NiWO{sub 4} nanoparticles were prepared via precipitation technique. Experimental parameters of procedure were optimized statistically. Highlights: Black-Right-Pointing-Pointer NiWO{sub 4} spherical nanoparticles were synthesized via direct precipitation method. Black-Right-Pointing-Pointer Taguchi robust design was used for optimization of synthesis reaction parameters. Black-Right-Pointing-Pointer Composition and structural properties of NiWO{sub 4} nanoparticles were characterized. Black-Right-Pointing-Pointer EDAX, XRD, SEM, FT-IR, UV-vis and photoluminescence techniques were employed. Black-Right-Pointing-Pointer Catalytic activity of the product in a cyclo-addition reaction was investigated. - Abstract: Taguchi robust design was applied to optimize experimental parameters for controllable, simple and fast synthesis of nickel tungstate nanoparticles. NiWO{sub 4} nanoparticles were synthesized by precipitation reaction involving addition of nickel ion solution to the tungstate aqueous reagent and then formation of nickel tungstate nucleolus which are insoluble in aqueous media. Effects of various parameters such as nickel and tungstate concentrations, flow rate of reagent addition and reactor temperature on diameter of synthesized nickel tungstate nanoparticles were investigated experimentally by the aid of orthogonal array design. The results for analysis of variance (ANOVA) showed that particle size of nickel tungstate can be effectively tuned by controlling significant variables involving nickel and tungstate concentrations and flow rate; while, temperature of the reactor has a no considerable effect on the size of NiWO{sub 4} particles. The ANOVA results proposed the optimum conditions for synthesis of nickel tungstate nanoparticles via this technique. Also, under optimum condition nanoparticles of NiWO{sub 4} were prepared and their structure and chemical composition were characterized by means of EDAX, XRD, SEM, FT-IR spectroscopy, UV

  9. Modeling Cl- concentration and δ37Cl profiles in pore water across a 250 m-thick indurated argillite at the Tournemire URL (France)

    International Nuclear Information System (INIS)

    Le Gal La Salle, Corinne; Rebeix, Romain; Lancelot, Joel; Matray, Jean-Michel; Bensenouci, Fethic; Michelot, Jean-Luc; Dauzeres, Alexandre; Wittebroodt, Charles; Frape, Shaun; ShouakarStash, Orphane

    2013-01-01

    Dissolved chloride in argillite pore water has been studied as a natural analogue for radionuclides potentially released from radioactive waste disposal. The Tournemire URL intersects impervious and compacted argillite. A previously obtained chloride concentration profile of intact rock is symmetric with a maximum concentration of 0.6±0.1 g/L, compared to 19 g/L for the original connate seawater. Dissolved chloride shows high δ 37 Cl values, ranging between +6 and +80/00 vs. SMOC. The modeled profile considers diffusive exchange between connate seawater and meteoric freshwater. Transport parameters were obtained by radial diffusion experiments. Numerical modeling was performed with the coupled reactive-transport code Hytec. Simulations suggest a diffusive-exchange time of 85±10 Ma for Cl, which correlates with a major erosional period. Simulated δ 37 Cl values between 1.002 and 1.003 agree with observed pore water δ 37 Cl. This study strongly suggests that the dissolved chloride profile in the argillites results from diffusive exchange and indicates that unfractured argillites can provide good confinement. (authors)

  10. Modeling Cl{sup -} concentration and δ{sup 37}Cl profiles in pore water across a 250 m-thick indurated argillite at the Tournemire URL (France)

    Energy Technology Data Exchange (ETDEWEB)

    Le Gal La Salle, Corinne; Rebeix, Romain; Lancelot, Joel [Universite de Nimes / Site GIS - 30035 Nimes cedex 01 (France); Aix-Marseille Universite, CEREGE UMR7330, 13545 Aix en Provence (France); Matray, Jean-Michel [IRSN, BP17 - 92262 Fontenay-aux-Roses Cedex (France); Bensenouci, Fethic [IRSN, BP17 - 92262 Fontenay-aux-Roses Cedex (France); IDES, UMR CNRS 8148 Universite Paris-Sud - 91405 Orsay Cedex (France); Michelot, Jean-Luc [IDES, UMR CNRS 8148 Universite Paris-Sud - 91405 Orsay Cedex (France); Dauzeres, Alexandre; Wittebroodt, Charles [IRSN, BP17 - 92262 Fontenay-aux-Roses Cedex (France); Frape, Shaun; ShouakarStash, Orphane [University of Waterloo, 200 University Avenue. West Waterloo, Ontario N2L 3G (Canada)

    2013-07-01

    Dissolved chloride in argillite pore water has been studied as a natural analogue for radionuclides potentially released from radioactive waste disposal. The Tournemire URL intersects impervious and compacted argillite. A previously obtained chloride concentration profile of intact rock is symmetric with a maximum concentration of 0.6±0.1 g/L, compared to 19 g/L for the original connate seawater. Dissolved chloride shows high δ{sup 37}Cl values, ranging between +6 and +80/00 vs. SMOC. The modeled profile considers diffusive exchange between connate seawater and meteoric freshwater. Transport parameters were obtained by radial diffusion experiments. Numerical modeling was performed with the coupled reactive-transport code Hytec. Simulations suggest a diffusive-exchange time of 85±10 Ma for Cl, which correlates with a major erosional period. Simulated δ{sup 37}Cl values between 1.002 and 1.003 agree with observed pore water δ{sup 37}Cl. This study strongly suggests that the dissolved chloride profile in the argillites results from diffusive exchange and indicates that unfractured argillites can provide good confinement. (authors)

  11. Relative effects of plasma, fibrinogen concentrate, and factor XIII on ROTEM coagulation profiles in an in vitro model of massive transfusion in trauma.

    Science.gov (United States)

    Schmidt, David E; Halmin, Märit; Wikman, Agneta; Östlund, Anders; Ågren, Anna

    2017-10-01

    Massive traumatic haemorrhage is aggravated through the development of trauma-induced coagulopathy, which is managed by plasma transfusion and/or fibrinogen concentrate administration. It is yet unclear whether these treatments are equally potent in ensuring adequate haemostasis, and whether additional factor XIII (FXIII) administration provides further benefits. In this study, we compared ROTEM whole blood coagulation profiles after experimental massive transfusion with different transfusion regimens in an in vitro model of dilution- and transfusion-related coagulopathy. Healthy donor blood was mixed 1 + 1 with six different transfusion regimens. Each regimen contained RBC, platelet concentrate, and either fresh frozen plasma (FFP) or Ringer's acetate (RA). The regimens were further augmented through addition of a low- or medium-dose fibrinogen concentrate and FXIII. Transfusion with FFP alone was insufficient to maintain tissue-factor activated clot strength, coincidental with a deficiency in fibrin-based clot strength. Fibrinogen concentrate conserved, but did not improve coagulation kinetics and overall clot strength. Only combination therapy with FFP and low-dose fibrinogen concentrate improved both coagulation kinetics and fibrin-based clot strength. Administration of FXIII did not result in an improvement of clot strength. In conclusion, combination therapy with both FFP and low-dose fibrinogen concentrate improved clotting time and produced firm clots, representing a possible preferred first-line regimen to manage trauma-induced coagulopathy when RBC and platelets are also transfused. Further research is required to identify optimal first-line transfusion fluids for massive traumatic haemorrhage.

  12. Drinking water pollution with nickel from water boilers; Nickel-Eintrag aus Wasserkochern ins Trinkwasser

    Energy Technology Data Exchange (ETDEWEB)

    Helmers, E. [Amt fuer Umweltschutz, Stuttgart (Germany). Chemisches Inst.

    1998-07-01

    The EU is planning to drop the threshold value for nickel in drinking water down to 20 {mu}g/l (present German threshold value: 50 {mu}g/l). Since ICP-MS-screenings of spot checks of water cookers were striking with respect to nickel, emissions of electrical water cookers have been investigated systematically within this study. As a result, water cookers with open heating coils are emitting relevant amounts of nickel into the water while it is brought to the boil. Investigation of eight preused water cookers with open heating coils revealed that the boiled water contained more than 50 {mu}g Ni/l in one case, more than 20 {mu}g Ni/l in two cases and, between 10 and 20 {mu}g Ni/l in two more cases, respectively. Removing of the lime by the aid of citric acid is increasing the nickel concentrations by a factor of up to 50 (max. 640 {mu}g/l). A new device was checked in a long-term test. During standard use with tapwater, Ni concentrations fall below the detection limit of 5 {mu}g Ni/l (120 cooking events). However, after removing of the lime, 5 times of cooking were necessary in order to diminish the Ni concentrations below the limit of 20 {mu}g/l. In the case of dionized water Ni concentrations below the limit of 20 {mu}g/l. In the case of deionized water Ni concentrations remained between 94 und 190 {mu}g/l. Health risk assessment: The intake of nickel with beverages made from hot water out of these cookers is in the range of 26 {mu}g/day. Considering an alltogether dietary nickel intake of 130-170 (900) {mu}g/day, this is not beyond the scope. However, according to the fact that nickel allergies (dermatitis) are very frequent (up to 13% of the population), this source should be limited or closed. (orig.) [Deutsch] Aus Anlass der geplanten Absenkung des Trinkwassergrenzwertes fuer Nickel auf 20 {mu}g/l sowie aufgrund von Auffaelligkeiten bei Stichprobenuntersuchungen wurde das Nickel-Emissionsverhalten von elektrischen Wassererhitzern betrachtet. Hierbei erwies sich

  13. Nickel speciation in several serpentine (ultramafic) topsoils via bulk synchrotron-based techniques

    Energy Technology Data Exchange (ETDEWEB)

    Siebecker, Matthew G.; Chaney, Rufus L.; Sparks, Donald L.

    2017-07-01

    Serpentine soils have elevated concentrations of trace metals including nickel, cobalt, and chromium compared to non-serpentine soils. Identifying the nickel bearing minerals allows for prediction of potential mobility of nickel. Synchrotron-based techniques can identify the solid-phase chemical forms of nickel with minimal sample treatment. Element concentrations are known to vary among soil particle sizes in serpentine soils. Sonication is a useful method to physically disperse sand, silt and clay particles in soils. Synchrotron-based techniques and sonication were employed to identify nickel species in discrete particle size fractions in several serpentine (ultramafic) topsoils to better understand solid-phase nickel geochemistry. Nickel commonly resided in primary serpentine parent material such as layered-phyllosilicate and chain-inosilicate minerals and was associated with iron oxides. In the clay fractions, nickel was associated with iron oxides and primary serpentine minerals, such as lizardite. Linear combination fitting (LCF) was used to characterize nickel species. Total metal concentration did not correlate with nickel speciation and is not an indicator of the major nickel species in the soil. Differences in soil texture were related to different nickel speciation for several particle size fractionated samples. A discussion on LCF illustrates the importance of choosing standards based not only on statistical methods such as Target Transformation but also on sample mineralogy and particle size. Results from the F-test (Hamilton test), which is an underutilized tool in the literature for LCF in soils, highlight its usefulness to determine the appropriate number of standards to for LCF. EXAFS shell fitting illustrates that destructive interference commonly found for light and heavy elements in layered double hydroxides and in phyllosilicates also can occur in inosilicate minerals, causing similar structural features and leading to false positive results in

  14. Nickel: makes stainless steel strong

    Science.gov (United States)

    Boland, Maeve A.

    2012-01-01

    Nickel is a silvery-white metal that is used mainly to make stainless steel and other alloys stronger and better able to withstand extreme temperatures and corrosive environments. Nickel was first identified as a unique element in 1751 by Baron Axel Fredrik Cronstedt, a Swedish mineralogist and chemist. He originally called the element kupfernickel because it was found in rock that looked like copper (kupfer) ore and because miners thought that "bad spirits" (nickel) in the rock were making it difficult for them to extract copper from it. Approximately 80 percent of the primary (not recycled) nickel consumed in the United States in 2011 was used in alloys, such as stainless steel and superalloys. Because nickel increases an alloy's resistance to corrosion and its ability to withstand extreme temperatures, equipment and parts made of nickel-bearing alloys are often used in harsh environments, such as those in chemical plants, petroleum refineries, jet engines, power generation facilities, and offshore installations. Medical equipment, cookware, and cutlery are often made of stainless steel because it is easy to clean and sterilize. All U.S. circulating coins except the penny are made of alloys that contain nickel. Nickel alloys are increasingly being used in making rechargeable batteries for portable computers, power tools, and hybrid and electric vehicles. Nickel is also plated onto such items as bathroom fixtures to reduce corrosion and provide an attractive finish.

  15. Polychlorinated biphenyls (PCBs) in industrial and municipal effluents: Concentrations, congener profiles, and partitioning onto particulates and organic carbon

    Energy Technology Data Exchange (ETDEWEB)

    Balasubramani, Aparna, E-mail: aparna.27889@gmail.com; Howell, Nathan L., E-mail: nlhowell@central.uh.edu; Rifai, Hanadi S., E-mail: rifai@uh.edu

    2014-03-01

    Wastewater effluent samples were collected in the summer of 2009 from 16 different locations which included municipal and industrial wastewater treatment plants and petrochemical industrial outfalls in the Houston area. The effluent samples were analyzed for all 209 polychlorinated biphenyls (PCBs) congeners using high resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS) using the USEPA method 1668A. The total PCBs (∑ 209) concentration in the dissolved medium ranged from 1.01 to 8.12 ng/L and ranged from 2.03 to 31.2 ng/L in the suspended medium. Lighter PCB congeners exhibited highest concentrations in the dissolved phase whereas, in the suspended phase, heavier PCBs exhibited the highest concentrations. The PCB homolog concentrations were dominated by monochlorobiphenyls through hexachlorobiphenyls, with dichlorobiphenyls exhibiting the highest concentration amongst them at most of the effluent outfalls, in the suspended phase. Both total suspended solids (TSS) and various organic carbon fractions played an important role in the distribution of the suspended fractions of PCBs in the effluents. The log K{sub oc} values determined in the effluents suggest that effluent PCB loads might have more risk and impact than what standard partitioning models predict. - Highlights: • 209 PCB congeners were measured in 16 different municipal and industrial effluents. • PCB congener differences were elucidated for the various effluent types. • In addition to log K{sub ow}, organic carbon and TSS affect partitioning of PCBs. • High concentrations of homolog 2 maybe due to biotransformation of PCBs.

  16. Modelling horizontal and vertical concentration profiles of ozone and oxides of nitrogen within high-latitude urban areas

    International Nuclear Information System (INIS)

    Nicholson, J.P.; Weston, K.J.

    2001-01-01

    Urban ozone concentrations are determined by the balance between ozone destruction, chemical production and supply through advection and turbulent down-mixing from higher levels. At high latitudes, low levels of solar insolation and high horizontal advection speeds reduce the photochemical production and the spatial ozone concentration patterns are largely determined by the reaction of ozone with nitric oxide and dry deposition to the surface. A Lagrangian column model has been developed to simulate the mean (monthly and annual) three-dimensional structure in ozone and nitrogen oxides (NO x ) concentrations in the boundary-layer within and immediately around an urban area. The short-time-scale photochemical processes of ozone and NO x , as well as emissions and deposition to the ground, are simulated. The model has a horizontal resolution of 1x1km and high resolution in the vertical. It has been applied over a 100x100km domain containing the city of Edinburgh (at latitude 56 o N) to simulate the city-scale processes of pollutants. Results are presented, using averaged wind-flow frequencies and appropriate stability conditions, to show the extent of the depletion of ozone by city emissions. The long-term average spatial patterns in the surface ozone and NO x concentrations over the model domain are reproduced quantitatively. The model shows the average surface ozone concentrations in the urban area to be lower than the surrounding rural areas by typically 50% and that the areas experiencing a 20% ozone depletion are generally restricted to within the urban area. The depletion of the ozone concentration to less than 50% of the rural surface values extends only 20m vertically above the urban area. A series of monitoring sites for ozone, nitric oxide and nitrogen dioxide on a north-south transect through the city - from an urban, through a semi-rural, to a remote rural location - allows the comparison of modelled with observed data for the mean diurnal cycle of ozone

  17. Improved mechanical and corrosion properties of nickel composite coatings by incorporation of layered silicates

    Energy Technology Data Exchange (ETDEWEB)

    Tientong, J. [University of North Texas, Department of Chemistry, 1155 Union Circle #305070, Denton, TX 76203 (United States); Ahmad, Y.H. [Center for Advanced Materials, P.O. Box 2713, Qatar University, Doha (Qatar); Nar, M.; D' Souza, N. [University of North Texas, Department of Mechanical and Energy Engineering, Denton, TX 76207 (United States); Mohamed, A.M.A. [Center for Advanced Materials, P.O. Box 2713, Qatar University, Doha (Qatar); Golden, T.D., E-mail: tgolden@unt.edu [University of North Texas, Department of Chemistry, 1155 Union Circle #305070, Denton, TX 76203 (United States)

    2014-05-01

    Layered silicates as exfoliated montmorillonite are incorporated into nickel films by electrodeposition, enhancing both corrosion resistance and hardness. Films were deposited onto stainless steel from a plating solution adjusted to pH 9 containing nickel sulfate, sodium citrate, and various concentrations of exfoliated montmorillonite. The presence of the incorporated layered silicate was confirmed by scanning electron microscopy and energy-dispersive X-ray spectroscopy. The composite films were also compact and smooth like the pure nickel films deposited under the same conditions as shown by scanning electron microscopy. X-ray diffraction results showed that incorporation of layered silicates into the film do not affect the nickel crystalline fcc structure. The nanocomposite films exhibited improved stability and adhesion. Pure nickel films cracked and peeled from the substrate when immersed in 3.5% NaCl solution within 5 days, while the nanocomposite films remained attached even after 25 days. The corrosion resistance of the nickel nanocomposites was also improved compared to nickel films. Nickel-layered silicate composites showed a 25% increase in Young's modulus and a 20% increase in hardness over pure nickel films. - Highlights: • 0.05–2% of layered silicates are incorporated into crystalline nickel films. • Resulting composite films had improved stability and adhesion. • Corrosion resistance improved for the composite films. • Hardness improved 20% and young's modulus improved 25% for the composite films.

  18. Quantitative detection of mass concentration of sand-dust storms via wind-profiling radar and analysis of Z- M relationship

    Science.gov (United States)

    Wang, Minzhong; Ming, Hu; Ruan, Zheng; Gao, Lianhui; Yang, Di

    2018-02-01

    With the aim to achieve quantitative monitoring of sand-dust storms in real time, wind-profiling radar is applied to monitor and study the process of four sand-dust storms in the Tazhong area of the Taklimakan Desert. Through evaluation and analysis of the spatial-temporal distribution of reflectivity factor, it is found that reflectivity factor ranges from 2 to 18 dBz under sand-dust storm weather. Using echo power spectrum of radar vertical beams, sand-dust particle spectrum and sand-dust mass concentration at the altitude of 600 ˜ 1500 m are retrieved. This study shows that sand-dust mass concentration reaches 700 μg/m3 under blowing sand weather, 2000 μg/m3 under sand-dust storm weather, and 400 μg/m3 under floating dust weather. The following equations are established to represent the relationship between the reflectivity factor and sand-dust mass concentration: Z = 20713.5 M 0.995 under floating dust weather, Z = 22988.3 M 1.006 under blowing sand weather, and Z = 24584.2 M 1.013 under sand-dust storm weather. The retrieval results from this paper are almost consistent with previous monitoring results achieved by former researchers; thus, it is implied that wind-profiling radar can be used as a new reference device to quantitatively monitor sand-dust storms.

  19. Effect of nickel on growth and 14 CO2 fixation in Chlorella (Chlorella pyrenoidosa)

    International Nuclear Information System (INIS)

    Subrahmanyam, A.D.; Rathore, V.S.

    1996-01-01

    Influence of nickel on growth, 14 C fixation and allocation of carbon among different biochemical fractions was investigated in Chlorella pyrenoidosa. Nickel significantly reduced the fresh and dry weights of chlorella cells. 14 C fixation was significantly reduced by increasing nickel concentration in growth media. 14 C allocation into different biochemical fractions was also markedly altered by nickel. Reduction in 14 CO 2 assimilation and carbon allocation into pigment-lipid fraction and residue fraction resulted in decreased chlorophyll content and dry weight. (author). 15 refs., 4 figs

  20. Dose-response testing with nickel sulphate using the TRUE test in nickel-sensitive individuals. Multiple nickel sulphate patch-test reactions do not cause an 'angry back'

    DEFF Research Database (Denmark)

    Andersen, Klaus Ejner; Lidén, C; Hansen, J

    1993-01-01

    The aim of this study was to employ the TRUE test assay to confirm the presence or absence of the 'angry back' phenomenon, i.e. that a strong positive patch-test reaction heightens adjacent patch-test response. In addition, we wished to establish the dose-response relationship for nickel sulphate...... back' phenomenon was not apparent in this study, as the spill-over effect was not statistically significant. Strong reactions to high concentrations of nickel sulphate did not enhance the response to adjacent lower concentrations of nickel sulphate....

  1. Effect of theobromine consumption on serum lipoprotein profiles in apparently healthy humans with low HDL-cholesterol concentrations

    NARCIS (Netherlands)

    Jacobs, Doris M.; Smolders, Lotte; Lin, Yuguang; Roo, de Niels; Trautwein, Elke A.; Duynhoven, van John; Mensink, Ronald P.; Plat, Jogchum; Mihaleva, Velitchka V.

    2017-01-01

    Scope: Theobromine is a major active compound in cocoa with allegedly beneficial effect on high-density-lipoprotein-cholesterol (HDL-CH). We have investigated the effect of theobromine (TB) consumption on the concentrations of triglyceride (TG) and cholesterol (CH) in various lipoprotein (LP)

  2. Dose per unit area - a study of elicitation of nickel allergy

    DEFF Research Database (Denmark)

    Fischer, Louise Arup; Menné, Torkil; Johansen, Jeanne Duus

    2007-01-01

    BACKGROUND: Experimental sensitization depends upon the amount of allergen per unit skin area and is largely independent of the area size. OBJECTIVES: This study aimed at testing if this also applies for elicitation of nickel allergy. PATIENTS/METHODS: 20 nickel allergic individuals were tested...... with a patch test and a repeated open application test (ROAT). Nickel was applied on small and large areas. The varying parameters were area, total dose and dose per unit area. RESULTS: In the patch test, at a low concentration [15 microg nickel (microg Ni)/cm(2)], there were significantly higher scores...... on the large area with the same dose per area as the small area. At higher concentrations of nickel, no significant differences were found. In the ROAT at low concentration (6.64 microg Ni/cm(2)), it was found that the latency period until a reaction appeared was significantly shorter on the large area...

  3. Toxic effects of lead and nickel nitrate on rat liver chromatin components.

    Science.gov (United States)

    Rabbani-Chadegani Iii, Azra; Fani, Nesa; Abdossamadi, Sayeh; Shahmir, Nosrat

    2011-01-01

    The biological activity of heavy metals is related to their physicochemical interaction with biological receptors. In the present study, the effect of low concentrations of nickel nitrate and lead nitrate (lead nitrate to chromatin compared to nickel nitrate. Also, the binding affinity of lead nitrate to histone proteins free in solution was higher than nickel. On the basis of the results, it is concluded that lead reacts with chromatin components even at very low concentrations and induce chromatin aggregation through histone-DNA cross-links. Whereas, nickel nitrate is less effective on chromatin at low concentrations, suggesting higher toxicity of lead nitrate on chromatin compared to nickel. Copyright © 2010 Wiley Periodicals, Inc.

  4. Hair cortisol concentrations exhibit a positive association with salivary cortisol profiles and are increased in obese prepubertal girls.

    Science.gov (United States)

    Papafotiou, Chrysanthe; Christaki, Eirini; van den Akker, Erica L T; Wester, Vincent L; Apostolakou, Filia; Papassotiriou, Ioannis; Chrousos, George P; Pervanidou, Panagiota

    2017-03-01

    Cortisol, a key mediator of the stress response, has been associated with obesity and metabolic syndrome manifestations as early as in childhood. Scalp hair cortisol has been proposed as a reliable index of long-term circulating cortisol. We aimed to investigate whether obese prepubertal girls have higher scalp hair cortisol than normal-weight controls and whether hair cortisol levels are correlated with salivary cortisol concentrations in these groups. In this cross-sectional study, 25 obese girls and 25 normal-weighted, age-matched girls were enrolled. Anthropometric evaluation, blood chemistry and salivary cortisol measurements were performed, and body mass index (BMI) and areas under the curve with respect to ground (AUCg) were calculated. Hair cortisol determination was performed with liquid chromatography-tandem mass spectrometry. Both hair cortisol concentrations and salivary cortisol AUCs were higher in the obese than the normal-weight girls (p cortisol and BMI Z-score was found (rho = .327, p = .025), while hair cortisol correlated positively with salivary cortisol AUCg (rho = .3, p = .048). We conclude that obese prepubertal girls have higher hair and salivary cortisol concentrations than their age-matched lean counterparts. Hair cortisol assessment seems to be a sensitive method of evaluating systemic cortisol exposure, which is supported by our finding that hair cortisol is associated with salivary concentrations of the hormone. Lay Summary: Cortisol is the key hormone of the stress response. Childhood obesity has been associated with cortisol production dysregulation. Our findings suggest a positive association between obesity in prepubertal girls and elevated cortisol concentrations, measured in saliva and hair.

  5. Modelling of occupational exposure to inhalable nickel compounds.

    Science.gov (United States)

    Kendzia, Benjamin; Pesch, Beate; Koppisch, Dorothea; Van Gelder, Rainer; Pitzke, Katrin; Zschiesche, Wolfgang; Behrens, Thomas; Weiss, Tobias; Siemiatycki, Jack; Lavoué, Jerome; Jöckel, Karl-Heinz; Stamm, Roger; Brüning, Thomas

    2017-07-01

    The aim of this study was to estimate average occupational exposure to inhalable nickel (Ni) using the German exposure database MEGA. This database contains 8052 personal measurements of Ni collected between 1990 and 2009 in adjunct with information on the measurement and workplace conditions. The median of all Ni concentrations was 9 μg/m 3 and the 95th percentile was 460 μg/m 3 . We predicted geometric means (GMs) for welders and other occupations centered to 1999. Exposure to Ni in welders is strongly influenced by the welding process applied and the Ni content of the used welding materials. Welding with consumable electrodes of high Ni content (>30%) was associated with 10-fold higher concentrations compared with those with a low content (exposure levels (GMs ≥20 μg/m 3 ) were observed in gas metal and shielded metal arc welders using welding materials with high Ni content, in metal sprayers, grinders and forging-press operators, and in the manufacture of batteries and accumulators. The exposure profiles are useful for exposure assessment in epidemiologic studies as well as in industrial hygiene. Therefore, we recommend to collect additional exposure-specific information in addition to the job title in community-based studies when estimating the health risks of Ni exposure.

  6. Electrolytic Recovery of Nickel from Spent Electroless Nickel Bath Solution

    Directory of Open Access Journals (Sweden)

    R. Idhayachander

    2010-01-01

    Full Text Available Plating industry is one of the largest polluting small scale industries and nickel plating is among the important surface finishing process in this industry. The waste generated during this operation contains toxic nickel. Nickel removal and recovery is of great interest from spent bath for environmental and economic reasons. Spent electroless nickel solution from a reed relay switch manufacturing industry situated in Chennai was taken for electrolytic recovery of nickel. Electrolytic experiment was carried out with mild steel and gold coated mild steel as cathode and the different parameters such as current density, time, mixing and pH of the solution were varied and recovery and current efficiency was studied. It was noticed that there was an increase in current efficiency up to 5 A/dm2 and after that it declines. There is no significant improvement with mixing but with modified cathode there was some improvement. Removal of nickel from the spent electroless nickel bath was 81.81% at 5 A/dm2 and pH 4.23. Under this condition, the content of nickel was reduced to 0.94 g/L from 5.16 g/L. with 62.97% current efficiency.

  7. A Study On Dispersion Stability Of Nickel Nanoparticles Synthesized By Wire Explosion In Liquid Media

    Directory of Open Access Journals (Sweden)

    Kim C.K.

    2015-06-01

    Full Text Available In this study, nickel nanoparticles were synthesized in ethanol using portable pulsed wire evaporation, which is a one-step physical method. From transmission electron microscopy images, it was found that the Ni nanoparticles exhibited a spherical shape with an average diameter of 7.3 nm. To prevent aggregation of the nickel nanoparticles, a polymer surfactant was added into the ethanol before the synthesis of nickel nanoparticles, and adsorbed on the freshly synthesized nickel nanoparticles during the wire explosion. The dispersion stability of the prepared nickel nanofluids was investigated by zeta-potential analyzer and Turbiscan optical analyzer. As a result, the optimum concentration of polymer surfactant to be added was suggested for the maximized dispersion stability of the nickel nanofluids.

  8. Electrodeionization 1: migration of nickel ions absorbed in a rigid, macroporous cation-exchange resin

    NARCIS (Netherlands)

    Spoor, P.B.; Veen, ter W.R.; Janssen, L.J.J.

    2001-01-01

    The removal of nickel ions from a packed bed of ion-exchange material under an applied potential is studied. This process involves the use of an electrodialysis type cell in which the centre compartment is filled with a packed bed of ion-exchange particles. The bed width, concentration of nickel in

  9. Determination of the concentration profile of chemical elements in superheater pipes; Determinacion del perfil de concentracion de elementos quimicos en tubos de sobrecalentadores

    Energy Technology Data Exchange (ETDEWEB)

    Aldape U, F; Aspiazu F, J [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    1986-05-15

    This work has for object to determine the profile of concentration of chemical elements at trace level in a superheater pipe of Thermoelectric Plants using the X-ray emission spectroscopy technique induced by protons coming from the Accelerator of the Nuclear Center. In the X-ray detection, a Si Li detector was used. The technique was chosen because it allows a multielemental analysis, of high sensitivity and precision. The results can help to understand the problems that are had in the change of flexibility or of corrosion. This will be from utility to the Federal Electricity Commission (CFE). (Author)

  10. Determination of the cesium-137 concentration profile in the main contamination focus of the radiological accident at Goiania-GO, Brazil

    International Nuclear Information System (INIS)

    Rocca, H.C.; Aoki, P.E.; Enokihara, C.T.; Rostelato, M.E.C.M.; Lepki, V.; Bambalas, E.

    1988-01-01

    The purpose of this paper is to describe the method used to determinate cesium-137 concentration profiles measured in function of depth and applied in seven areas considered as the main contamination focus. Since november 14 th to december 17 th 1987, 125 soil drillings were made and a total of 740 soil samples were prepared. Obtained data allowed to calculate the soil volume to be removed from contaminate areas. It was verified that after remotions the remaining activity was approximately 0,89 Ci. (author) [pt

  11. Performance and metabolite profile of dairy cows fed tropical grasses and concentrates containing crude protein with low or high degradability

    Directory of Open Access Journals (Sweden)

    Raphael dos Santos Gomes

    Full Text Available ABSTRACT Ten Holstein-Zebu crossbred cows distributed into two simultaneous Latin squares (5 × 5 as a 2 × 2 factorial arrangement formed by chopped sugarcane or elephant grass silage, both with high or low protein degradability supplements and a corn silage as a control treatment, were compared using orthogonal contrasts. The studied variables were the performance, plasma concentrations of urea-N, glucose, and creatinine, urine-N and milk urea-N, and the nychthemeral variation in NH3-N in the rumen fluid of dairy cows. Nutrient intake, milk production, and milk composition were affected by the treatments. The total mixed ration containing elephant grass silage combined with rumen undegradable protein (RUP provided balanced amounts of carbon and nitrogen in the rumen. This effect may explain the 18% increase in milk yield compared with the other treatments. The diurnal pattern of ruminal NH3-N was interpreted with a sinusoid model. In general, cows fed elephant grass silage exhibited higher concentrations of blood plasma and milk urea-N than animals fed sugarcane. The cows that consumed elephant grass silage with rumen degradable protein concentrate showed a higher milk urea-N compared with animals that consumed elephant grass silage with the RUP concentrate. The use of diets based on corn silage leads to a better use of nitrogen compounds because these diets resulted in lower levels of urea-N in the plasma, urine, and milk at the same level of milk production compared with diets containing elephant grass silage or chopped sugarcane as roughages. In sugarcane-based diets, even greater nitrogen losses in the urine are observed, despite the presence of readily fermentable carbohydrates in the diet.

  12. Adsorption of nickel on synthetic hydroxyapatite from aqueous solutions

    International Nuclear Information System (INIS)

    Rosskopfova, O.; Galambos, M.; Pivarciova, L.; Rajec, P.; Caplovicova, M.

    2013-01-01

    The sorption of nickel on synthetic hydroxyapatite was investigated using a batch method and radiotracer technique. The hydroxyapatite samples used in experiments were a commercial hydroxyapatite and hydroxyapatite of high crystallinity with Ca/P ratio of 1.563 and 1.688, respectively, prepared by a wet precipitation process. The sorption of nickel on hydroxyapatite was pH independent ranging from 4.5 to 6.5 as a result of buffering properties of hydroxyapatite. The adsorption of nickel was rapid and the percentage of Ni sorption on both samples of hydroxyapatite was >98 % during the first 15-30 min of the contact time for initial Ni 2+ concentration of 1 x 10 -4 mol dm -3 . The experimental data for sorption of nickel have been interpreted in the term of Langmuir isotherm and the value of maximum sorption capacity of nickel on a commercial hydroxyapatite and hydroxyapatite prepared by wet precipitation process was calculated to be 0.184 and 0.247 mmol g -1 , respectively. The sorption of Ni 2+ ions was performed by ion-exchange with Ca 2+ cations on the crystal surface of hydroxyapatite under experimental conditions. The competition effect of Co 2+ and Fe 2+ towards Ni 2+ sorption was stronger than that of Ca 2+ ions. NH 4 + ions have no apparent effect on nickel sorption. (author)

  13. Moringa oleifera-based diet protects against nickel-induced hepatotoxicity in rats

    Science.gov (United States)

    Stephen Adeyemi, Oluyomi; Sokolayemji Aroge, Cincin; Adewumi Akanji, Musbau

    2017-01-01

    Multiple health-promoting effects have been attributed to the consumption of Moringa oleifera leaves, as part of diet without adequate scientific credence. This study evaluated the effect of M. oleifera-based diets on nickel (Ni) - induced hepatotoxicity in rats. Male rats assigned into six groups were given oral administration of 20 mg/kg body weight nickel sulfate in normal saline and either fed normal diet orM. oleifera-based diets for 21 days. All animals were sacrificed under anesthesia 24 hours after the last treatment. Ni exposure elevated the rat plasma activities of alanine transaminase, aspartate transaminase and alkaline phosphatase significantly. Ni exposure also raised the levels of triglyceride, total cholesterol and low-density lipoprotein cholesterol while depleting the high-density lipoprotein cholesterol concentration. Further, Ni exposure raised rat plasma malondialdehyde but depleted reduced glutathione concentrations. The histopathological presentations revealed inflammation and cellular degeneration caused by Ni exposure. We show evidence thatM. oleifera-based diets protected against Ni-induced hepatotoxicity by improving the rat liver function indices, lipid profile as well as restoring cellular architecture and integrity. Study lends credence to the health-promoting value ofM. oleifera as well as underscores its potential to attenuate hepatic injury. PMID:28808207

  14. Dissolved oxygen concentration profiles in the hyporheic zone through the use of a high density fiber optic measurement network

    Science.gov (United States)

    Reeder, W. J.; Quick, A. M.; Farrell, T. B.; Benner, S. G.; Feris, K. P.; Tonina, D.

    2013-12-01

    The hyporheic zone (HZ) is a potentially important source of the potent greenhouse gas, nitrous oxide (N2O); stream processes may account for up to 10% of global anthropogenic N2O emissions. However, mechanistic understanding and predictive quantification of this gas flux is hampered by complex temporally and spatially variable interactions between flow dynamics and biogeochemical processes. Reactive inorganic nitrogen (Nr) is typically present at low concentrations in natural stream waters, but many rural and urban streams suffer from an excess of Nr, typically in the form of ammonium (NH4+) and nitrate (NO3-). These reactive species are either assimilated by living biomass or transformed by microbial processes. The two primary microbial transformations of Nr are nitrification (NH4+ to NO3-) and denitrification (NO3- to N2). Denitrification, which occurs almost exclusively in the anoxic zone of the HZ, permanently removes between 30-70% of all Nr entering streams, other mechanisms may retain nitrogen. The mass transport of reactive species (i.e. O2, NO3- and N2O) by hyporheic flow strongly influences reaction rates, residence times, and subsequent N2O flux. By extension, stream flow and channel morphology presumably control, and may be effective predictors of, N2O generation rates. By recreating the stream processes in the University of Idaho flume, we are able to control the bed morphology, fluxes and residence times through the HZ and concentrations of Nr from exogenous (stream water) and endogenous (organic material in the streambed) sources. For the present experiment, the flume was divided into three streams, each with different morphologies (3, 6 and 9cm dunes) and all using the same source water. Stream water for this first experimental phase had no significant loading of Nr. As such, all reaction products were the result of endogenous sources of Nr. To measure dissolved oxygen (DO) concentrations we deployed 120 channels of a novel, fiber-optic optode

  15. Point defects in nickel

    International Nuclear Information System (INIS)

    Peretto, P.

    1969-01-01

    The defects in electron irradiated nickel (20 deg. K) or neutron irradiated nickel (28 deg. K) are studied by simultaneous analysis using the magnetic after-effect, electron microscopy and electrical resistivity recovery. We use zone refined nickel (99.999 per cent) which, for some experiments, is alloyed with a small amount of iron (for example 0.1 per cent Fe). The temperature dependant electrical recovery may be divided in four stages. The sub-stages I B (31 deg. K), I C (42 deg. K), I D (from to 57 deg. K) and I E (62 deg. K) of stage I are due to the disappearance of single interstitials into vacancies. The interstitial defect has a split configuration with a migration energy of about 0.15 eV. In the close pair which disappears in stage I B the interstitial is found to be in a 3. neighbour position whilst in stage I D it is near the direction from the vacancy. In stage I E there is no longer any interaction between the interstitial and the vacancy. The stage II is due to more complicated interstitial defects: di-interstitials for stage II B (84 deg. K) and larger and larger interstitial loops for the following sub-stages. The loops may be seen by electron microscopy. Impurities can play the role of nucleation centers for the loops. Stages III A (370 deg. K) and III B (376 deg. K) are due to two types of di-vacancies. During stage IV (410 deg. K) the single vacancies migrate. Vacancy type loops and interstitial type loops grow concurrently and disappear at about 800 deg. K as observed by electron microscopy. (author) [fr

  16. Nickel, cobalt, and their alloys

    CERN Document Server

    2000-01-01

    This book is a comprehensive guide to the compositions, properties, processing, performance, and applications of nickel, cobalt, and their alloys. It includes all of the essential information contained in the ASM Handbook series, as well as new or updated coverage in many areas in the nickel, cobalt, and related industries.

  17. Modelling of the Hypothalamic-Pituitary-Adrenal Axis Perturbations by Externally Induced Cholesterol Pulses of Finite Duration and with Asymmetrically Distributed Concentration Profile

    Science.gov (United States)

    Stanojević, A.; Marković, V. M.; Čupić, Ž.; Vukojević, V.; Kolar-Anić, L.

    2017-12-01

    A model was developed that can be used to study the effect of gradual cholesterol intake by food on the HPA axis dynamics. Namely, well defined oscillatory dynamics of vital neuroendocrine hypothalamic-pituitary-adrenal (HPA) axis has proven to be necessary for maintaining regular basal physiology and formulating appropriate stress response to various types of perturbations. Cholesterol, as a precursor of all steroid HPA axis hormones, can alter the dynamics of HPA axis. To analyse its particular influence on the HPA axis dynamics we used stoichiometric model of HPA axis activity, and simulate cholesterol perturbations in the form of finite duration pulses, with asymmetrically distributed concentration profile. Our numerical simulations showed that there is a complex, nonlinear dependence between the HPA axis responsiveness and different forms of applied cholesterol concentration pulses, indicating the significance of kinetic modelling, and dynamical systems theory for the understanding of large-scale self-regulatory, and homeostatic processes within this neuroendocrine system.

  18. Hydrometallurgical separation of rare earth elements, cobalt and nickel from spent nickel-metal-hydride batteries

    Science.gov (United States)

    Rodrigues, Luiz Eduardo Oliveira Carmo; Mansur, Marcelo Borges

    The separation of rare earth elements, cobalt and nickel from NiMH battery residues is evaluated in this paper. Analysis of the internal content of the NiMH batteries shows that nickel is the main metal present in the residue (around 50% in weight), as well as potassium (2.2-10.9%), cobalt (5.1-5.5%), rare earth elements (15.3-29.0%) and cadmium (2.8%). The presence of cadmium reveals that some Ni-Cd batteries are possibly labeled as NiMH ones. The leaching of nickel and cobalt from the NiMH battery powder with sulfuric acid is efficient; operating variables temperature and concentration of H 2O 2 has no significant effect for the conditions studied. A mixture of rare earth elements is separated by precipitation with NaOH. Finally, solvent extraction with D2EHPA (di-2-ethylhexyl phosphoric acid) followed by Cyanex 272 (bis-2,4,4-trimethylpentyl phosphinic acid) can separate cadmium, cobalt and nickel from the leach liquor. The effect of the main operating variables of both leaching and solvent extraction steps are discussed aiming to maximize metal separation for recycling purposes.

  19. Performance and metabolite profile of dairy cows fed tropical grasses and concentrates containing crude protein with low or high degradability

    OpenAIRE

    Gomes, Raphael dos Santos; Oliveira, Tadeu Silva de; Pereira, José Carlos; Vieira, Ricardo Augusto Mendonça; Henrique, Douglas Sampaio; Fernandes, Alberto Magno; Leonel, Fernando de Paula

    2016-01-01

    ABSTRACT Ten Holstein-Zebu crossbred cows distributed into two simultaneous Latin squares (5 × 5) as a 2 × 2 factorial arrangement formed by chopped sugarcane or elephant grass silage, both with high or low protein degradability supplements and a corn silage as a control treatment, were compared using orthogonal contrasts. The studied variables were the performance, plasma concentrations of urea-N, glucose, and creatinine, urine-N and milk urea-N, and the nychthemeral variation in NH3-N in th...

  20. Concentration profiles in the wake of a sphere buried in a granular bed through which fluid flows

    International Nuclear Information System (INIS)

    Guedes de Carvalho, J.R.F.; Delgado, J.M.P.Q.; Alves, M.A.

    2005-01-01

    The concentration distribution in the wake of a soluble sphere immersed in a granular bed of inerts has been obtained numerically, for transport by both advection and diffusion/dispersion. Fluid flow in the granular bed around the sphere was assumed to follow Darcy's law and, at each point, dispersion of solute was considered in both the cross-stream and stream-wise directions. The elliptic PDE equation, resulting from a differential material balance on the solute, has been solved numerically over a wide range of values of the relevant parameters. (authors)

  1. Concentration profiles in the wake of a sphere buried in a granular bed through which fluid flows

    Energy Technology Data Exchange (ETDEWEB)

    Guedes de Carvalho, J.R.F.; Delgado, J.M.P.Q.; Alves, M.A. [Porto Univ., Dpet. de Engenharia Quimica, Faculdade de Engenharia (Portugal)

    2005-07-01

    The concentration distribution in the wake of a soluble sphere immersed in a granular bed of inerts has been obtained numerically, for transport by both advection and diffusion/dispersion. Fluid flow in the granular bed around the sphere was assumed to follow Darcy's law and, at each point, dispersion of solute was considered in both the cross-stream and stream-wise directions. The elliptic PDE equation, resulting from a differential material balance on the solute, has been solved numerically over a wide range of values of the relevant parameters. (authors)

  2. The effects of applied current on one-dimensional interdiffusion between copper and nickel in spark plasma sintering

    Energy Technology Data Exchange (ETDEWEB)

    Rudinsky, S.; Gauvin, R.; Brochu, M., E-mail: mathieu.brochu@mcgill.ca [Department of Mining and Materials Engineering, McGill University, 3610 University Street, Montreal, Quebec H3A 0C5 (Canada)

    2014-10-21

    Spark plasma sintering (SPS) is a powder metallurgy technique that employs the use of fast sintering kinetics to produce final consolidated components in a matter of minutes. In order to use blended powders in SPS to obtain fully alloyed parts, diffusion during sintering must be understood. An investigation into the effects of current on the diffusion of copper and nickel was performed using SPS. Bulk specimens were used to generate diffusion couples in SPS in alternating orientations with respect to the direction of the current. Control samples were produced using a horizontal insertion vacuum furnace. Experiments were performed at temperatures between 850°C and 1000°C for 3 h. Concentration profiles were obtained by the use of both energy-dispersive spectroscopy and a Monte Carlo simulated correction curve. Diffusion coefficients and activation energies were calculated for samples produced by SPS and annealing without current. It was shown that, at temperatures near 0.9 T{sub m}, the application of current in SPS inhibits diffusion between copper and nickel due to the re-orientation of electrons caused by the loss of ferromagnetism in nickel. Activation energy for diffusion is, however, decreased due to the temperature gradients arising from the difference in resistivity between the two species.

  3. Measuring and modeling polymer concentration profiles near spindle boundaries argues that spindle microtubules regulate their own nucleation

    Science.gov (United States)

    Kaye, Bryan; Stiehl, Olivia; Foster, Peter J.; Shelley, Michael J.; Needleman, Daniel J.; Fürthauer, Sebastian

    2018-05-01

    Spindles are self-organized microtubule-based structures that segregate chromosomes during cell division. The mass of the spindle is controlled by the balance between microtubule turnover and nucleation. The mechanisms that control the spatial regulation of microtubule nucleation remain poorly understood. While previous work found that microtubule nucleators bind to pre-existing microtubules in the spindle, it is still unclear whether this binding regulates the activity of those nucleators. Here we use a combination of experiments and mathematical modeling to investigate this issue. We measured the concentration of microtubules and soluble tubulin in and around the spindle. We found a very sharp decay in the concentration of microtubules at the spindle interface. This is inconsistent with a model in which the activity of nucleators is independent of their association with microtubules but consistent with a model in which microtubule nucleators are only active when bound to pre-existing microtubules. This argues that the activity of microtubule nucleators is greatly enhanced when bound to pre-existing microtubules. Thus, microtubule nucleators are both localized and activated by the microtubules they generate.

  4. Constraining dark matter halo profiles and galaxy formation models using spiral arm morphology. II. Dark and stellar mass concentrations for 13 nearby face-on galaxies

    International Nuclear Information System (INIS)

    Seigar, Marc S.; Davis, Benjamin L.; Berrier, Joel; Kennefick, Daniel

    2014-01-01

    We investigate the use of spiral arm pitch angles as a probe of disk galaxy mass profiles. We confirm our previous result that spiral arm pitch angles (P) are well correlated with the rate of shear (S) in disk galaxy rotation curves. We use this correlation to argue that imaging data alone can provide a powerful probe of galactic mass distributions out to large look-back times. We then use a sample of 13 galaxies, with Spitzer 3.6 μm imaging data and observed Hα rotation curves, to demonstrate how an inferred shear rate coupled with a bulge-disk decomposition model and a Tully-Fisher-derived velocity normalization can be used to place constraints on a galaxy's baryon fraction and dark matter halo profile. Finally, we show that there appears to be a trend (albeit a weak correlation) between spiral arm pitch angle and halo concentration. We discuss implications for the suggested link between supermassive black hole (SMBH) mass and dark halo concentration, using pitch angle as a proxy for SMBH mass.

  5. Physically based method for measuring suspended-sediment concentration and grain size using multi-frequency arrays of acoustic-doppler profilers

    Science.gov (United States)

    Topping, David J.; Wright, Scott A.; Griffiths, Ronald; Dean, David

    2014-01-01

    As the result of a 12-year program of sediment-transport research and field testing on the Colorado River (6 stations in UT and AZ), Yampa River (2 stations in CO), Little Snake River (1 station in CO), Green River (1 station in CO and 2 stations in UT), and Rio Grande (2 stations in TX), we have developed a physically based method for measuring suspended-sediment concentration and grain size at 15-minute intervals using multifrequency arrays of acoustic-Doppler profilers. This multi-frequency method is able to achieve much higher accuracies than single-frequency acoustic methods because it allows removal of the influence of changes in grain size on acoustic backscatter. The method proceeds as follows. (1) Acoustic attenuation at each frequency is related to the concentration of silt and clay with a known grain-size distribution in a river cross section using physical samples and theory. (2) The combination of acoustic backscatter and attenuation at each frequency is uniquely related to the concentration of sand (with a known reference grain-size distribution) and the concentration of silt and clay (with a known reference grain-size distribution) in a river cross section using physical samples and theory. (3) Comparison of the suspended-sand concentrations measured at each frequency using this approach then allows theory-based calculation of the median grain size of the suspended sand and final correction of the suspended-sand concentration to compensate for the influence of changing grain size on backscatter. Although this method of measuring suspended-sediment concentration is somewhat less accurate than using conventional samplers in either the EDI or EWI methods, it is much more accurate than estimating suspended-sediment concentrations using calibrated pump measurements or single-frequency acoustics. Though the EDI and EWI methods provide the most accurate measurements of suspended-sediment concentration, these measurements are labor-intensive, expensive, and

  6. Effect of oral mineral and energy supplementation on blood mineral concentrations, energetic and inflammatory profile, and milk yield in dairy cows affected with dystocia.

    Science.gov (United States)

    Benzaquen, M; Galvão, K N; Coleman, A E; Santos, J E P; Goff, J P; Risco, C A

    2015-05-01

    The objectives of this study were to determine the effect of mineral/energy supplementation of dairy cows with dystocia on blood mineral concentrations, energetic and inflammatory profiles, and milk yield. Multiparous Holstein cows with dystocia were randomly assigned into two groups, (1) treated with a mineral/energy supplement (DME, n= 18) and (2) not treated (DNT, n= 22). A group of cows with normal parturition were randomly selected and were left untreated (NNT, n= 25). Cows in DME received an oral drench of 110 g of calcium and 400 g of propionate as calcium propionate plus 110 g potassium chloride and 150 g of magnesium sulfate administered within 6 h of calving and again 3 days post-partum. Compared to cows with a normal parturition, dystocic cows had decreased plasma calcium concentrations, increased plasma haptoglobin, decreased milk yield at 1 day post-partum, and tended to have increased rectal temperatures from 1 to 12 days post-partum. Compared with cows in DNT, those in DME had decreased plasma calcium concentrations and increased plasma magnesium concentrations 2 and 3 days post-partum, and a tendency for an increase in rectal temperature from 1 to 12 days post-partum. Dystocia is detrimental to calcium homeostasis post-partum, but mineral/energy supplementation as undertaken in this study is not recommended for use in cows with dystocia. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Initial study of Nickel Electrolyte for EnFACE Process

    Directory of Open Access Journals (Sweden)

    Tri Widayatno

    2015-03-01

    Full Text Available Nickel electrolyte for a micro-pattern transfer process without photolithography, EnFACE, has been developed. Previous work on copper deposition indicated that a conductivity of ~2.7 Sm-1 is required. Electrochemical parameters of electrolyte i.e. current density and overpotential are also crucial to govern a successful pattern replication. Therefore, the investigation focused on the measurement of physicochemical properties and electrochemical behaviour of the electrolyte at different nickel concentrations and complexing agents of chloride and sulfamate. Nickel electrolytes containing sulfamate, chloride and combined sulfamate-chloride with concentrations between 0.14 M and 0.3 M were investigated. Physicochemical properties i.e. pH and conductivity were measured to ensure if they were in the desired value. The electrochemical behaviour of the electrolytes was measured by polarisation experiments in a standard three-electrode cell. The working electrode was a copper disc (surface area of 0.196 cm2 and the counter electrode was platinum mesh. The potential was measured againts a saturated calomel reference electrode (SCE. The experiments were carried out at various scan rate and Rotating Disc Electrode (RDE rotation speed to see the effect of scan rate and agitation. Based on the measured physicochemical properties, the electrolyte of 0.19 M nickel sulfamate was chosen for experimentation. Polarisation curve of agitated solution suggested that overall nickel electrodeposition reaction is controlled by a combination of kinetics and mass transfer.  Reduction potential of nickel was in the range of -0.7 to -1.0 V. The corresponding current densities for nickel deposition were in the range of -0.1 to -1.5 mA cm-2.

  8. Axial concentration profiles and N{sub 2}O flue gas in a pilot scale bubbling fluidised bed coal combustor

    Energy Technology Data Exchange (ETDEWEB)

    Tarelho, L.A.C.; Matos, M.A.A.; Pereira, F.J.M.A. [Environment and Planning Department, University of Aveiro, 3810-193 Aveiro (Portugal)

    2005-05-15

    Atmospheric Bubbling Fluidised Bed Coal Combustion (ABFBCC) of a bituminous coal and anthracite with particle diameters in the range 500-4000 {mu}m was investigated in a pilot-plant facility (circular section with 0.25 m internal diameter and 3 m height). The experiments were conducted at steady-state conditions using three excess air levels (10%, 25% and 50%) and bed temperatures in the 750-900 {sup o}C range. Combustion air was staged, with primary air accounting for 100%, 80% and 60% of total combustion air. For both types of coal, virtually no N{sub 2}O was found in significant amounts inside the bed. However, just above the bed-freeboard interface, the N{sub 2}O concentration increased monotonically along the freeboard and towards the exit flue. The N{sub 2}O concentrations in the reactor ranged between 0-90 ppm during bituminous coal combustion and 0-30 ppm for anthracite. For both coals, the lowest values occurred at the higher bed temperature (900 {sup o}C) with low excess air (10%) and high air staging (60% primary air), whereas the highest occurred at the lower bed temperature (750 {sup o}C for bituminous, 825 {sup o}C for anthracite) with high excess air (50%) and single stage combustion. Most of the observed results could be qualitatively interpreted in terms of a set of homogeneous and heterogeneous reactions, where catalytic surfaces (such as char, sand and coal ash) can play an important role in the formation and destruction of N{sub 2}O and its precursors (such as HCN, NH{sub 3} and HCNO) by free radicals (O, H, OH) and reducing species (H{sub 2}, CO, HCs)

  9. Gene expression profiling of preovulatory follicle in the buffalo cow: effects of increased IGF-I concentration on periovulatory events.

    Directory of Open Access Journals (Sweden)

    Jyotsna U Rao

    Full Text Available The preovulatory follicle in response to gonadotropin surge undergoes dramatic biochemical, and morphological changes orchestrated by expression changes in hundreds of genes. Employing well characterized bovine preovulatory follicle model, granulosa cells (GCs and follicle wall were collected from the preovulatory follicle before, 1, 10 and 22 h post peak LH surge. Microarray analysis performed on GCs revealed that 450 and 111 genes were differentially expressed at 1 and 22 h post peak LH surge, respectively. For validation, qPCR and immunocytochemistry analyses were carried out for some of the differentially expressed genes. Expression analysis of many of these genes showed distinct expression patterns in GCs and the follicle wall. To study molecular functions and genetic networks, microarray data was analyzed using Ingenuity Pathway Analysis which revealed majority of the differentially expressed genes to cluster within processes like steroidogenesis, cell survival and cell differentiation. In the ovarian follicle, IGF-I is established to be an important regulator of the above mentioned molecular functions. Thus, further experiments were conducted to verify the effects of increased intrafollicular IGF-I levels on the expression of genes associated with the above mentioned processes. For this purpose, buffalo cows were administered with exogenous bGH to transiently increase circulating and intrafollicular concentrations of IGF-I. The results indicated that increased intrafollicular concentrations of IGF-I caused changes in expression of genes associated with steroidogenesis (StAR, SRF and apoptosis (BCL-2, FKHR, PAWR. These results taken together suggest that onset of gonadotropin surge triggers activation of various biological pathways and that the effects of growth factors and peptides on gonadotropin actions could be examined during preovulatory follicle development.

  10. Comparative effects of cobalt, nickel and copper on plant growth

    Energy Technology Data Exchange (ETDEWEB)

    Brenchley, W E

    1938-11-01

    An account is given of the present position of our knowledge with regard to the distribution and the physiological importance of nickel and cobalt, in relation to plants and animals. Experiments on barley and broad beans were carried out in water cultures with the sulfates and chlorides of cobalt, nickel and copper. In every case a range of low concentrations did little or no damage, but toxic action occurred abruptly above a concentration which varied with the species and with the compound. With barley, copper was the most poisonous element in either compound, but the differences were not striking. Low concentrations of the sulfate were innocuous, but parallel low strengths of the chloride caused a slight, significant depression in growth. With broad beans, cobalt was much more poisonous than either nickel or copper, particularly with the sulfate. No slight depression with low concentrations of the chloride was noticeable with this species. The morphological response to toxicity varied with the element concerned. Copper, in poisonous strengths, caused shortening and bunching of barley roots, whereas nickel and cobalt permitted the growth of elongated roots of a very attenuated nature. The individuality of plant response to poison was frequently shown by the great variation in growth in the borderline concentrations just below those which caused marked depression of growth.

  11. The Effects of Electroless Nickel Plating Bath Conditions on Stability of Solution and Properties of Deposit

    International Nuclear Information System (INIS)

    Huh, Jin; Lee, Jae Ho

    2000-01-01

    Electroless depositions of nickel were conducted in different bath conditions to find optimum conditions of electroless nickel plating at low operating temperature and pH. The effect of complexing reagent on stability of plating solution was investigated. Sodium citrate complexed plating solution is more stable than sodium pyrophosphate complexed solution. The effects of nickel salt concentration, reducing agent, complexing agent and inhibitor on deposition rate was investigated. The effects of pH on deposition rate and content of phosphorous in deposited nickel were also analyzed. Electroless deposited nickel become crystallized with increasing pH due to lower phosphorous content. In optimum operating bath condition, deposition rate was 7 μm/hr at 60 .deg. C and pH 10.0 without stabilizer. The rate was decreased with stabilizer concentration

  12. Nickel Excretion in Urine after Oral Administration

    DEFF Research Database (Denmark)

    Menne, T.; Mikkelsen, H. I.; Solgaard, Per Bent

    1978-01-01

    In recent years the importance of internal exposure to nickel in patients with recurrent hand eczema and nickel allergy has become evident. The present study was performed in order to investigate the value of urinary nickel determinations as an index of oral nickel intake. After oral administration...

  13. Nickel affects gill and muscle development in oriental fire-bellied toad (Bombina orientalis) embryos

    Energy Technology Data Exchange (ETDEWEB)

    Park, Chan Jin; Song, Sang Ha; Kim, Dae Han; Gye, Myung Chan, E-mail: mcgye@hanyang.ac.kr

    2017-01-15

    Highlights: • Nickel inhibited the development of external gill in B. orientalis embryos. • The 168 h LC{sub 50} and EC{sub 50} values of nickel were 33.8 and 5.4 μM, respectively, in embryos. • Nickel induced abnormal tail development of embryos. • NF stage 26–31 was the most sensitive window for embryos to nickel exposure. • Nickel affected the calcium-dependent myogenic gene expression in embryos. - Abstract: The developmental toxicity of nickel was examined in the embryos of Bombina orientalis, a common amphibian in Korea. Based on a standard frog embryo teratogenesis assay, the LC{sub 50} and EC{sub 50} for malformation of nickel after 168 h of treatment were 33.8 μM and 5.4 μM, respectively. At a lethal concentration (100 μM), nickel treatment decreased the space between gill filaments and caused epithelial swelling and abnormal fusion of gill filaments. These findings suggest that nickel affects the functional development of gills, leading to embryonic death. At sublethal concentrations (1–10 μM), nickel produced multiple embryonic abnormalities, including bent tail and tail dysplasia. At 10 μM, nickel significantly decreased tail length and tail muscle fiber density in tadpoles, indicating inhibition of myogenic differentiation. Before hatching, the pre-muscular response to muscular response stages (stages 26–31) were the most sensitive period to nickel with respect to tail muscle development. During these stages, MyoD mRNA was upregulated, whereas myogenic regulatory factor 4 mRNA was downregulated by 0.1 μM nickel. Calcium-dependent kinase activities in muscular response stage embryos were significantly decreased by nickel, whereas these activities were restored by exogenous calcium. In tadpoles, 10 μM nickel significantly decreased the expression of the myosin heavy chain and the 12/101 muscle marker protein in the tail. Expression was restored by exogenous calcium. Our results indicate that nickel affects muscle development by

  14. Mercury and nickel contents in fish meat

    Directory of Open Access Journals (Sweden)

    Tomas Toth

    2016-10-01

    Full Text Available The main aim of our work was to identify the content of mercury and nickel in selected fish species. Consumers today are increasingly aware of the association between diet and health, and thus in Europe consume more and more fish. Fish is a valuable source of high quality protein, minerals and vitamins, and fatty fish are also rich in omega-3-polyunsaturated fatty acids, which are normally considered to be beneficial to health. In our work we determined content of mercury and nickel harvested fish in particular were the following species: Common goldfish (Carassius auratus, L., Common roach (Rutilus rutilus, L. and Common bream (Abramis brama, L. Concentrations of mercury and nickel was analyzed and results evaluated according to current standards and compared to the values ​​established by the Codex Alimentarius of the Slovak Republic and the EU Commission Regulation no. 1881/2006, as well as in the EU Commission Regulation no. 420/2011 and no. 269/2008. In our research area we analysed 19 samples of fish muscle. Samples were taken from two water reservoirs – Golianovo and Vráble.  The highest mercury content was in sample Rutilus 1 - 0.052632 mg/kg. Lowest mercury content was in sample Abramis 2  - 0.010431 mg/kg. Largest nickel content was in meat of Abramis  - sample 2  - 0.78 mg/kg. Minimum content of nickel was in sample Carassius 1  - 0.11 mg/kg. We got out of the limit values ​​specified: Codex Alimentarius SR - Mercury 0.5 mg/kg and  Regulation of the EU Commission no. 1881/2006, no. 420/2011 and no. 629/2008. To optimize the protection of the population, it is necessary to continue to monitor the concentration of mercury in fish and fish products. Risk management strategy must focus on reducing potential exposure derived from consumption of fish. In particular, the definition of maximum levels for methylmercury, advising consumers and environmental activities oriented to reduce contamination.

  15. Further studies on the use of enzyme profiles to monitor residue accumulation in wildlife: Plasma enzymes in starlings fed graded concentrations of morsodren, DDE, Aroclor 1254, and malathion

    Science.gov (United States)

    Dieter, M.P.

    1975-01-01

    Wild-trapped starlings (Sturnus vulgaris) were fed concentrations of Morsodren (2, 4, and 8 ppm), DDE or Aroclor 1254 (5, 25, and 100 ppm), or malathion (8, 35, and 160 ppm) that were found to be sublethal in pen-reared Coturnix quail fed these amounts for 12 weeks. Plasma enzymes had to be measured earlier than planned in starlings fed Morsodren (at three weeks) or the organochlorine compounds (at seven weeks) because of unexpected, subsequent mortality. Variations in enzyme response were greater in wild than in pen-reared birds, but not enough to mask the toxicant-induced changes in enzyme activity. Cholinesterase activities decreased in birds fed Morsodren or malathion, and increased in those fed the organochlorine compounds. Lactate dehydrogenase activities increased two-fold in starlings fed Morsodren and two- to four-fold in those fed the organochlorine compounds, but only 50% in those fed malathion. Further examination of enzyme profiles showed that creatine kinase and aspartate aminotransferase activities increased two-to four-fold in birds fed Morsodren or the organochlorine compounds but not at all in those fed malathion. Thus the classes of environmental contaminants fed to starlings could be easily distinguished by these enzymatic parameters. Evaluation of enzymatic profiles appears to be a potentially valuable technique to monitor the presence of toxicants in wild populations, especially if used to complement standard chemical residue analyses. Here the residue analyses showed, after three weeks feeding, that mercury in the carcasses reflected the concentrations fed daily, whereas accumulation in the livers was two- to four-fold greater. After seven weeks feeding, liver residues of either organochlorine compound were about three-fold higher than the concentrations fed daily. However, four times as much DDE as Aroclor 1254 had accumulated in the carcasses.

  16. Assessment of respiratory carcinogenicity associated with exposure to metallic nickel: a review.

    Science.gov (United States)

    Sivulka, Donna J

    2005-11-01

    Human studies prior to 1990 have shown an association between respiratory cancer and exposure to some nickel compounds, but not to metallic nickel. Numerous reviews have examined the nature of the association between nickel compounds and respiratory cancer, but little has been published on metallic nickel. This paper reviews the animal and human cancer-related data on metallic nickel to determine whether the conclusions regarding metallic nickel reached a decade ago still apply. Based upon past and current human studies, metallic nickel appears to show little evidence of carcinogenicity when present at the same or higher concentrations than those seen in current workplace environments. By comparison, animal studies currently available have shown mixed results. A number of studies have shown evidence of carcinogenicity in animals exposed to nickel powders via injection, but other studies have shown no or inconsistent results in animals exposed via inhalation or intratracheal instillation. Further studies in animals via inhalation and humans would be helpful in elucidating the respiratory carcinogenic potential of metallic nickel.

  17. The transport of fallout 137Cs within undisturbed soils in Nigeria based on measured soil concentration profiles

    International Nuclear Information System (INIS)

    Ajayi, I.R.

    2007-12-01

    The transport of fallout 137 Cs within the Nigerian soil has been studied in this paper by the compartment and the diffusion-convection models. The measured concentrations of the radionuclide in the soil layers were examined by the models in order to estimate the transport parameters of residence half-time, migration velocity, diffusion coefficient and the convective velocities of the radionuclide within the soils. The residence half-times were observed to be short and decreased with soil depth with a mean ranging from 0.3 years at 0 - 2cm soil depth in the Akure site to 1.4 years at 10-15cm depth in the Igbeti site. The migration velocity ν, calculated from the residence times with the consideration of the different thicknesses of layers were observed to decrease slowly with depth at all the sampling sites with a range from 3.62 cm y -1 at the Igbeti site to 8.21 cm.y -1 at the Ikogosi site. The migration velocities obtained are quite higher than those reported in literature for global fallout. The range of the diffusion coefficient was 0.72 - 1.02 cm 2 per year while that of the convective velocity was from 0.07 to 0.16 cm per year. Diffusion coefficients were observed to be higher than the convective velocities at all sampling points. (author)

  18. EELS measurements of boron concentration profiles in p-a-Si and nip a-Si solar cells

    DEFF Research Database (Denmark)

    Van Aken, Bas B.; Duchamp, Martial; Boothroyd, Chris

    2012-01-01

    The p-type Si layer in a-Si and μc-Si solar cells on foil needs to fulfil several important requirements. The layer is necessary to create the electric field that separates the photo-generated charge carriers; the doping also increases the conductivity to conduct the photocurrent to the front......-3, using core-loss EELS combined with numerical analysis. We control the band gap and activation energy of p-a-SiC by varying the B2H6 and CH4 flow during deposition in the process chamber. We have found a linear relation between the activation energy of the dark conductivity Eact and the optical...... band gap E04. Modelling shows that the optimum efficiency in nip solar cells is obtained when the p-a-SiC band gap is slightly larger than the band gap of the absorber layer. We have assessed the potential of core-loss EELS for detecting B and C concentrations as low as 1020cm-3 in a spatially resolved...

  19. Inhibitory effects of ZnO nanoparticles on aerobic wastewater biofilms from oxygen concentration profiles determined by microelectrodes

    International Nuclear Information System (INIS)

    Hou, Jun; Miao, Lingzhan; Wang, Chao; Wang, Peifang; Ao, Yanhui; Qian, Jin; Dai, Shanshan

    2014-01-01

    Highlights: • Temporal and spatial inhibitory effects of ZnO NPs on biofilms were investigated. • 50 mg/L nano-ZnO inhibited the microbial activities only in biofilm outer layer. • Adsorbed ZnO NPs had no adverse effects on the cell membrane integrity of biofilms. • Dissolution of ZnO NPs to toxic zinc ions was the main mechanism of toxicity. - Abstract: The presence of ZnO NPs in waste streams can negatively affect the efficiency of biological nutrient removal from wastewater. However, details of the toxic effects of ZnO NPs on microbial activities of wastewater biofilms have not yet been reported. In this study, the temporal and spatial inhibitory effects of ZnO NPs on the O 2 respiration activities of aerobic wastewater biofilms were investigated using an O 2 microelectrode. The resulting time–course microelectrode measurements demonstrated that ZnO NPs inhibited O 2 respiration within 2 h. The spatial distributions of net specific O 2 respiration were determined in biofilms with and without treatment of 5 or 50 mg/L ZnO NPs. The results showed that 50 mg/L of nano-ZnO inhibited the microbial activities only in the outer layer (∼200 μm) of the biofilms, and bacteria present in the deeper parts of the biofilms became even more active. Scanning electron microscopy (SEM) analysis showed that the ZnO NPs were adsorbed onto the biofilm, but these NPs had no adverse effects on the cell membrane integrity of the biofilms. It was found that the inhibition of O 2 respiration induced by higher concentrations of ZnO NPs (50 mg/L) was mainly due to the release of zinc ions by dissolution of the ZnO NPs

  20. Modifying the strength and strain concentration profile within collagen scaffolds using customizable arrays of poly-lactic acid fibers.

    Science.gov (United States)

    Mozdzen, Laura C; Vucetic, Alan; Harley, Brendan A C

    2017-02-01

    The tendon-to-bone junction is a highly specialized tissue which dissipates stress concentrations between mechanically dissimilar tendon and bone. Upon injury, the local heterogeneities across this insertion are not regenerated, leading to poor functional outcomes such as formation of scar tissue at the insertion and re-failure rates exceeding 90%. Although current tissue engineering methods are moving towards the development of spatially-graded biomaterials to begin to address these injuries, significant opportunities remain to engineer the often complex local mechanical behavior of such biomaterials to enhance their bioactivity. Here, we describe the use of three-dimensional printing techniques to create customizable arrays of poly-lactic acid (PLA) fibers that can be incorporated into a collagen scaffold under development for tendon bone junction repair. Notably, we use additive manufacturing concepts to generate arrays of spatially-graded fibers from biodegradable PLA that are incorporated into collagen scaffolds to create a collagen-PLA composite. We demonstrate the ability to tune the mechanical performance of the fiber-scaffold composite at the bulk scale. We also demonstrate the incorporation of spatially-heterogeneous fiber designs to establish non-uniform local mechanical performance of the composite biomaterial under tensile load, a critical element in the design of multi-compartment biomaterials for tendon-to-bone regeneration applications. Together, this work highlights the capacity to use multi-scale composite biomaterials to control local and bulk mechanical properties, and provides key insights into design elements under consideration for mechanically competent, multi-tissue regeneration platforms. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Inhibitory effects of ZnO nanoparticles on aerobic wastewater biofilms from oxygen concentration profiles determined by microelectrodes

    Energy Technology Data Exchange (ETDEWEB)

    Hou, Jun [Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098 (China); College of Environment, Hohai University, Nanjing 210098 (China); Miao, Lingzhan, E-mail: mlz1988@126.com [Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098 (China); College of Environment, Hohai University, Nanjing 210098 (China); Wang, Chao, E-mail: hhuhjy973@126.com [Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098 (China); College of Environment, Hohai University, Nanjing 210098 (China); Wang, Peifang; Ao, Yanhui; Qian, Jin; Dai, Shanshan [Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098 (China); College of Environment, Hohai University, Nanjing 210098 (China)

    2014-07-15

    Highlights: • Temporal and spatial inhibitory effects of ZnO NPs on biofilms were investigated. • 50 mg/L nano-ZnO inhibited the microbial activities only in biofilm outer layer. • Adsorbed ZnO NPs had no adverse effects on the cell membrane integrity of biofilms. • Dissolution of ZnO NPs to toxic zinc ions was the main mechanism of toxicity. - Abstract: The presence of ZnO NPs in waste streams can negatively affect the efficiency of biological nutrient removal from wastewater. However, details of the toxic effects of ZnO NPs on microbial activities of wastewater biofilms have not yet been reported. In this study, the temporal and spatial inhibitory effects of ZnO NPs on the O{sub 2} respiration activities of aerobic wastewater biofilms were investigated using an O{sub 2} microelectrode. The resulting time–course microelectrode measurements demonstrated that ZnO NPs inhibited O{sub 2} respiration within 2 h. The spatial distributions of net specific O{sub 2} respiration were determined in biofilms with and without treatment of 5 or 50 mg/L ZnO NPs. The results showed that 50 mg/L of nano-ZnO inhibited the microbial activities only in the outer layer (∼200 μm) of the biofilms, and bacteria present in the deeper parts of the biofilms became even more active. Scanning electron microscopy (SEM) analysis showed that the ZnO NPs were adsorbed onto the biofilm, but these NPs had no adverse effects on the cell membrane integrity of the biofilms. It was found that the inhibition of O{sub 2} respiration induced by higher concentrations of ZnO NPs (50 mg/L) was mainly due to the release of zinc ions by dissolution of the ZnO NPs.

  2. Nickel aggregates produced by radiolysis

    International Nuclear Information System (INIS)

    Marignier, J.L.; Belloni, J.

    1988-01-01

    Nickel aggregates with subcolloidal size and stable in water have been synthesized by inhibiting the corrosion by the medium. The protective effect of the surfactant is discussed in relation with the characteristics of various types of polyvinyl alcohol studied. The reactivity of aggregates towards oxidizing compounds, nitro blue tetrazolium, methylene blue, silver ions, oxygen, methylviologen, enables an estimation of the redox potential of nickel aggregates (E = - 04 ± 0.05 V). It has been applied to quantitative analysis of the particles in presence of nickel ions. 55 refs [fr

  3. Mechanisms of nickel toxicity in microorganisms

    OpenAIRE

    Macomber, Lee; Hausinger, Robert P.

    2011-01-01

    Nickel has long been known to be an important human toxicant, including having the ability to form carcinomas, but until recently nickel was believed to be an issue only to microorganisms living in nickel-rich serpentine soils or areas contaminated by industrial pollution. This assumption was overturned by the discovery of a nickel defense system (RcnR/RcnA) found in microorganisms that live in a wide range of environmental niches, suggesting that nickel homeostasis is a general biological co...

  4. Respiratory carcinogenicity assessment of soluble nickel compounds.

    OpenAIRE

    Oller, Adriana R

    2002-01-01

    The many chemical forms of nickel differ in physicochemical properties and biological effects. Health assessments for each main category of nickel species are needed. The carcinogenicity assessment of water-soluble nickel compounds has proven particularly difficult. Epidemiologic evidence indicates an association between inhalation exposures to nickel refinery dust containing soluble nickel compounds and increased risk of respiratory cancers. However, the nature of this association is unclear...

  5. [Concentrations and Component Profiles PAHs in Surface Soils and Wheat Grains from the Cornfields Close to the Steel Smelting Industry in Handan, Hebei Province].

    Science.gov (United States)

    Wu, Di; Wang, Yi-long; Liu, Wei-jian; Chen, Yuan-chen; Fu, Xiao-fang; Tao, Shu; Liu, Wen-xin

    2016-02-15

    In this study, paired surface soil and mature wheat grain samples were collected in the cornfields near the large Handan Steel Manufacturer; and the total concentrations and compositional profiles of the parent PAHs were measured, then the spatial distribution characteristics and correlation with total organic carbon fractions in soil were determined. Accordingly, a preliminary source identification was performed, and the association between PAHs in surface soil and wheat grain was briefly discussed. The median concentration of total PAHs in surface soils from the cornfields of Handan was 398.9 ng x g(-1) (ranged from 123.4 ng x g(-1) to 1626.4 ng x g(-1), where around 18% and 10% of all the studied soil samples were over the corresponding quality criteria for total PAHs and B [a] P in soils, respectively. The MMW and HMW species were the main components in the compositional profiles of surface soils. Based on the specific isomeric ratios of PAHs species, coal/biomass combustion and transportation fuel (tail gas) were the dominant mixed sources for the local PAHs emission. The fractions of surface soil TOC had significant positive correlations with the total PAHs and also with the individual components with different rings. In addition, the median concentration of total PAHs in wheat grains collected in the cornfields near the Handan Steel Manufacture was 27.0 ng x g(-1) (ranged from 19.0-34.0 ng x g(-1)). The levels in wheat grains were not high, and lower than the related hygienic standards of food proposed by EU and China. The LMW and MMW PAHs with 2 to 4 rings occupied a larger proportion, more than 84% of the total PAHs, which was largely different from the component profiles in surface soils. This situation suggested that the local sources of PAHs in wheat grains may originate not only from surface soil via root absorption and internal transportation, but also from ambient air through dry and wet deposition on the leaf surface (stoma).

  6. A passive air sampler for characterizing the vertical concentration profile of gaseous phase polycyclic aromatic hydrocarbons in near soil surface air.

    Science.gov (United States)

    Zhang, Yuzhong; Deng, Shuxing; Liu, Yanan; Shen, Guofeng; Li, Xiqing; Cao, Jun; Wang, Xilong; Reid, Brian; Tao, Shu

    2011-03-01

    Air-soil exchange is an important process governing the fate of polycyclic aromatic hydrocarbons (PAHs). A novel passive air sampler was designed and tested for measuring the vertical concentration profile of 4 low molecular weight PAHs in gaseous phase (PAH(LMW4)) in near soil surface air. Air at various heights from 5 to 520 mm above the ground was sampled by polyurethane foam disks held in down-faced cartridges. The samplers were tested at three sites: A: an extremely contaminated site, B: a site near A, and C: a background site on a university campus. Vertical concentration gradients were revealed for PAH(LMW4) within a thin layer close to soil surface at the three sites. PAH concentrations either decreased (Site A) or increased (Sites B and C) with height, suggesting either deposition to or evaporation from soils. The sampler is a useful tool for investigating air-soil exchange of gaseous phase semi-volatile organic chemicals. Copyright © 2010 Elsevier Ltd. All rights reserved.

  7. Nickel in silicon: Room-temperature in-diffusion and interaction with radiation defects

    Energy Technology Data Exchange (ETDEWEB)

    Yarykin, Nikolai [Institute of Microelectronics Technology, RAS, Chernogolovka (Russian Federation); Weber, Joerg [Technische Universitaet Dresden (Germany)

    2017-07-15

    Nickel is incorporated into silicon wafers during chemomechanical polishing in an alkaline Ni-contaminated slurry at room temperature. The nickel in-diffusion is detected by DLTS depth profiles of a novel Ni{sub 183} level, which is formed due to a reaction between the diffusing nickel and the VO centers introduced before the polishing. The Ni{sub 183} profile extends up to 10 μm after a 2 min polishing. The available data provide a lower estimate for the room-temperature nickel diffusivity D{sub Ni} > 10{sup -9} cm{sup 2} s{sup -1}. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  8. Spectrochemical analysis of impurities in nickel and in nickel oxide

    International Nuclear Information System (INIS)

    Goldbart, Z.; Lorber, A.; Harel, A.

    1981-11-01

    Various spectrochemical methods are described for the quantitative determination of 23 impurities in metallic nickel and in nickel oxide. The average limit of detection is from 1 to 5 ppm and the dynamic range lies over 2.5 orders of magnitude. The elements that were determined are: Al,B,Ba,Bi,Ca,Cd,Co,Cu,Fe,Ga,Ge,In,Mg,Mn,Mo,Nb,Si,Sn,Sr,Ti,Cr,V. (author)

  9. Exoelectron emission in determination of strength parameters of nickel

    Energy Technology Data Exchange (ETDEWEB)

    Dus-Sitek, M.; Olszowski, Z. (Technical Univ. of Czestochowa (Poland). Inst. of Physics); Sujak, B. (Wroclaw Univ. (Poland). Inst. of Experimental Physics)

    1983-01-01

    A correlation between the intensity of PhSEE curve as registered from nickel during continuous uniaxial plastic deformation and the S-S curve is derived. A relationship of surface concentration of vacancies with respect to the degree of specimen deformation is also discussed.

  10. Cathodic protection of steel by electrodeposited zinc-nickel alloy coatings

    Energy Technology Data Exchange (ETDEWEB)

    Baldwin, K.R.; Smith, C.J.E. [Defence Research Agency, Farnborough (United Kingdom). Structural Materials Centre; Robinson, M.J. [Cranfield Univ. (United Kingdom). School of Industrial and Manufacturing Science

    1995-12-01

    The ability of electrodeposited zinc-nickel alloy coatings to cathodically protect steel was studied in dilute chloride solutions. The potential distribution along steel strips partly electroplated with zinc-nickel alloys was determined, and the length of exposed steel that was held below the minimum protection potential (E{sub prot}) was taken as a measure of the level of cathodic protection (CP) provided by the alloy coatings. The level of CP afforded by zinc alloy coatings was found to decrease with increasing nickel content. When nickel content was increased to {approx} {ge} 21 wt%, no CP was obtained. Surface analysis of uncoupled zinc-nickel alloys that were immersed in sodium chloride (NaCl) solutions showed the concentration of zinc decreased in the surface layers while the concentration of nickel increased, indicating that the alloys were susceptible to dezincification. The analysis of zinc-nickel alloy coatings on partly electroplated steel strips that were immersed in chloride solution showed a significantly higher level of dezincification than that found for uncoupled alloy coatings. This effect accounted for the rapid loss of CP afforded to steel by some zinc alloy coatings, particularly those with high initial nickel levels.

  11. Chronic Exposure to Particulate Nickel Induces Neoplastic Transformation in Human Lung Epithelial Cells

    Directory of Open Access Journals (Sweden)

    Amie L. Holmes

    2013-11-01

    Full Text Available Nickel is a well-known human lung carcinogen with the particulate form being the most potent; however, the carcinogenic mechanism remains largely unknown. Few studies have investigated the genotoxicity and carcinogenicity of nickel in its target cell, human bronchial epithelial cells. Thus, the goal of this study was to investigate the effects of particulate nickel in human lung epithelial cells. We found that nickel subsulfide induced concentration- and time-dependent increases in both cytotoxicity and genotoxicity in human lung epithelial cells (BEP2D. Chronic exposure to nickel subsulfide readily induced cellular transformation, inducing 2.55, 2.9 and 2.35 foci per dish after exposure to 1, 2.5 and 5 μg/cm2 nickel subsulfide, respectively. Sixty-one, 100 and 70 percent of the foci isolated from 1, 2.5, and 5 μg/cm2 nickel subsulfide treatments formed colonies in soft agar and the degree of soft agar colony growth increased in a concentration-dependent manner. Thus, chronic exposure to particulate nickel induces genotoxicity and cellular transformation in human lung epithelial cells.

  12. Removing nickel from nickel-coated carbon fibers

    Science.gov (United States)

    Hardianto, A.; Hertleer, C.; De Mey, G.; Van Langenhove, L.

    2017-10-01

    Conductive fibers/yarns are one of the most important materials for smart textiles because of their electrically conductive functionality combined with flexibility and light weight. They can be applied in many fields such as the medical sector, electronics, sensors and even as thermoelectric generators. Temperature sensors, for example, can be made using the thermocouple or thermopile principle which usually uses two different metal wires that can produce a temperature-dependent voltage. However, if metal wires are inserted into a textile structure, they will decrease the flexibility properties of the textile product. Nickel-coated Carbon Fiber (NiCF), a conductive textile yarn, has a potential use as a textile-based thermopile if we can create an alternating region of carbon and nickel along the fiber which in turn it can be used for substituting the metallic thermopile. The idea was to remove nickel from NiCF in order to obtain a yarn that contains alternating zones of carbon and nickel. Due to no literature reporting on how to remove nickel from NiCF, in this paper we investigated some chemicals to remove nickel from NiCF.

  13. Characterising palladium-silver and palladium-nickel alloy membranes using SEM, XRD and PIXE

    International Nuclear Information System (INIS)

    Keuler, J.N.; Lorenzen, L.; Sanderson, R.D.; Prozesky, V.; Przybylowicz, W.J.

    1999-01-01

    Palladium alloy membranes were prepared by successive electroless plating steps on an alumina-zirconia support membrane. Palladium, silver and nickel were deposited in layers and then the metal films were heat treated for 5 h in a hydrogen atmosphere at 650 deg. C. The topography of the metal coatings and cross-sections of the films (before and after heating) were characterised using scanning electron microscopy (SEM). XRD was used to determine the crystal phase of the alloy coatings. Both SEM and XRD provide only surface information and therefore micro-PIXE was used to extract depth information of the alloy coating. Concentration profiles across the thickness of the films were constructed to determine penetration of the coating into the support membrane pores during electroless plating and to investigate diffusion of coated layers during the heating step

  14. Extended solubility and martensitic hcp nickel formation in antimony implanted nickel

    International Nuclear Information System (INIS)

    Johnson, E.; Sarholt-Kristensen, L.; Johansen, A.

    1982-01-01

    Radiation damage microstructure and associated disorder have been investigated in antimony implanted nickel crystals using combined RBS and TEM analyses. In crystals implanted at and below room temperature with 80 keV Sb + ions to a fluence of 5x10 20 m -2 , the retained antimony concentration in the implantation zone is approaching 15 at.%, with nearly all the antimony located substitutionally. The associated disorder as seen in the RBS analysis is insignificant. Annealing up to 600 0 C has little influence on the antimony distribution, whilst the dechanneling level is reduced. TEM and diffraction analysis of room temperature implanted samples show that the radiation damage consists of dense distributions of dislocation clusters and tangles, superimposed on a rather homogeneous background of new phase particles, identified as hcp nickel. The particles have a size 0.1-0.2 μm. The high substitutional antimony concentration at and below room temperature, which exceeds the solubility limit, indicates that its formation is thermally diffusionless and rather an effect of radiation enhanced solubility. The diffusionless nature of the microstructure is also indicated from the presence of martensitic hcp nickel, believed to form due to relief of radiation induced internal stress. (Auth.)

  15. GADEP Continuous PM2.5 mass concentration data, VIIRS Day Night Band SDR (SVDNB), MODIS Terra Level 2 water vapor profiles (infrared algorithm for atmospheric profiles for both day and night, NWS surface meteorological data

    Science.gov (United States)

    Data descriptions are provided at the following urls:GADEP Continuous PM2.5 mass concentration data - https://aqs.epa.gov/aqsweb/documents/data_mart_welcome.htmlhttps://www3.epa.gov/ttn/amtic/files/ambient/pm25/qa/QA-Handbook-Vol-II.pdfVIIRS Day Night Band SDR (SVDNB) http://www.class.ngdc.noaa.gov/saa/products/search?datatype_family=VIIRS_SDRMODIS Terra Level 2 water vapor profiles (infrared algorithm for atmospheric profiles for both day and night -MOD0&_L2; http://modis-atmos.gsfc.nasa.gov/MOD07_L2/index.html NWS surface meteorological data - https://www.ncdc.noaa.gov/isdThis dataset is associated with the following publication:Wang, J., C. Aegerter, and J. Szykman. Potential Application of VIIRS Day/Night Band for Monitoring Nighttime Surface PM2.5 Air Quality From Space. ATMOSPHERIC ENVIRONMENT. Elsevier Science Ltd, New York, NY, USA, 124(0): 55-63, (2016).

  16. Anatomy of a turbidity current: Concentration and grain size structure of a deep-sea flow revealed by multiple-frequency acoustic profilers

    Science.gov (United States)

    Simmons, S.; Parsons, D. R.; Paull, C. K.; Barry, J.; Chaffey, M. R.; Gwiazda, R.; O'Reilly, T. C.; Maier, K. L.; Rosenberger, K. J.; Talling, P.; Xu, J.

    2017-12-01

    Turbidity currents are responsible for transporting large volumes of sediment to the deep ocean, yet remain poorly understood due to the limited number of field observations of these episodic, high energy events. As part of the Monterey Coordinated Canyon Experiment high resolution, sub-minute acoustic velocity and backscatter profiles were acquired with downward-looking acoustic Doppler current profilers (ADCPs) distributed along the canyon on moorings at depths ranging from 270 to 1,900 m over a period of 18 months. Additionally, three upward-looking ADCPs on different frequencies (300, 600 and 1200 kHz) profiled the water column above a seafloor instrument node (SIN) at 1850 m water depth. Traps on the moorings collected sediment carried by the flows at different heights above the seafloor and sediment cores were taken to determine the depositional record produced by the flows. Several sediment-laden turbidity flows were observed during the experiment, three of which ran out for more than 50 km to water depths of greater than 1,900 m and were observed on all of the moorings. Flow speeds of up to 6 m/s were observed and individual moorings, anchored by railroad wheels, moved up to 7.8 km down-canyon during these powerful events. We present results based on a novel analysis of the multiple-frequency acoustic data acquired by the ADCPs at the SIN integrated with grain size data from the sediment traps, close to the deepest mooring in the array where the flow thickened to the 70 m height of the ADCP above the bed. The analysis allows, for the first time, retrieval of the suspended sediment concentration and vertical distribution of grain size structure within a turbidity in spectacular detail. The details of the stratification and flow dynamics will be used to re-evaluate and discuss our existing models for these deep-sea flows.

  17. Polybrominated diphenyl ethers in road and farmland soils from an e-waste recycling region in Southern China: Concentrations, source profiles, and potential dispersion and deposition

    International Nuclear Information System (INIS)

    Luo Yong; Luo Xiaojun; Lin Zhen; Chen Shejun; Liu Juan; Mai Bixian; Yang Zhongyi

    2009-01-01

    The present study analyzed road soils collected near the dismantling workshops of an e-waste recycling region in South China to determine the PBDE profiles. Farmland soils at a distance of about 2 km from the dismantling workshops were also collected to evaluate the potential dispersion and deposition of PBDEs in the surrounding environment. Total PBDE concentrations ranged from 191 to 9156 ng/g dry weight in road soils and from 2.9 to 207 ng/g dry weight in farmland soils, respectively. Three PBDE source profiles were observed from the road soils by principal component analysis, and were compared with the congener patterns in different technical products. Elevated abundances of octa- and nona-congeners were found in the 'deca-' derived PBDEs as compared with the deca-BDE products. The results in this study suggest that debromination of BDE 209 may have occurred during the use of electric and electronic equipment and/or another technical formulation (Bromkal 79-8DE) was also likely the source of octa- and nona-congeners in e-wastes. Comparison of the PBDE patterns in road and farmland soils implied that the PBDEs in farmland soils have been subject to complex environmental processes

  18. Gene expression profiling of a Zn-tolerant and a Zn-sensitive Suillus luteus isolate exposed to increased external zinc concentrations.

    Science.gov (United States)

    Muller, L A H; Craciun, A R; Ruytinx, J; Lambaerts, M; Verbruggen, N; Vangronsveld, J; Colpaert, J V

    2007-10-01

    Complementary DNA (cDNA)-amplified fragment-length polymorphism (AFLP) was applied to analyze transcript profiles of a Zn-tolerant and a Zn-sensitive isolate of the ectomycorrhizal basidiomycete Suillus luteus, both cultured with and without increased external zinc concentrations. From the obtained transcript profiles that covered approximately 2% of the total expected complement of genes in S. luteus, 144 nonredundant, differentially expressed transcript-derived fragments (TDFs), falling in different classes of expression pattern, were isolated and sequenced. Thirty-six of the represented genes showed homology to function-known genes, whereas 6 matched unknown protein coding sequences, and 102 were possibly novel. Although relatively few TDFs were found to be responsive to the different zinc treatments, their modulated expression levels may suggest a different transcriptional response to zinc treatments in both isolates. Among the identified genes that could be related to heavy-metal detoxification or the tolerance trait were genes encoding for homologues of a heat-shock protein, a putative metal transporter, a hydrophobin, and several proteins involved in ubiquitin-dependent proteolysis.

  19. Nickel Oxide and Nickel Co-doped Graphitic Carbon Nitride Nanocomposites and its Octylphenol Sensing Application

    KAUST Repository

    Gong, Wanyun

    2015-11-16

    Nickel oxide and nickel co-doped graphitic carbon nitride (NiO-Ni-GCN) nanocomposites were successfully prepared by thermal treatment of melamine and NiCl2 6H2O. NiO-Ni-GCN nanocomposites showed superior electrochemical catalytic activity for the oxidation of octylphenol to pure GCN. A detection method of octylphenol in environmental water samples was developed based at NiO-Ni-GCN nanocomposites modified electrode under infrared light irradiation. Differential pulse voltammetry was used as the analytic technique of octylphenol, exhibiting stable and specific concentration-dependent oxidation signal in the presence of octylphenol in the range of 10nM to 1μM and 1μM to 50μM, with a detection limit of 3.3nM (3S/N). © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Nickel Oxide and Nickel Co-doped Graphitic Carbon Nitride Nanocomposites and its Octylphenol Sensing Application

    KAUST Repository

    Gong, Wanyun; Zou, Jing; Zhang, Sheng; Zhou, Xin; Jiang, Jizhou

    2015-01-01

    Nickel oxide and nickel co-doped graphitic carbon nitride (NiO-Ni-GCN) nanocomposites were successfully prepared by thermal treatment of melamine and NiCl2 6H2O. NiO-Ni-GCN nanocomposites showed superior electrochemical catalytic activity for the oxidation of octylphenol to pure GCN. A detection method of octylphenol in environmental water samples was developed based at NiO-Ni-GCN nanocomposites modified electrode under infrared light irradiation. Differential pulse voltammetry was used as the analytic technique of octylphenol, exhibiting stable and specific concentration-dependent oxidation signal in the presence of octylphenol in the range of 10nM to 1μM and 1μM to 50μM, with a detection limit of 3.3nM (3S/N). © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Distribution ratios on Dowex 50W resins of metal leached in the caron nickel recovery process

    International Nuclear Information System (INIS)

    Reynolds, B.A.; Metsa, J.C.; Mullins, M.E.

    1980-05-01

    Pressurized ion exchange on Dowex 50W-X8 and 50W-X12 resins was investigated using elution techniques to determine distribution ratios for copper, nickel, and cobalt complexes contained in ammonium carbonate solution, a mixture which approximates the waste liquor from the Caron nickel recovery process. Results were determined for different feed concentrations, as well as for different concentrations and pH values of the ammonium carbonate eluant. Distribution ratios were compared with those previously obtained from a continuous annular chromatographic system. Separation of copper and nickel was not conclusively observed at any of the conditions examined

  2. Distribution ratios on Dowex 50W resins of metal leached in the caron nickel recovery process

    Energy Technology Data Exchange (ETDEWEB)

    Reynolds, B.A.; Metsa, J.C.; Mullins, M.E.

    1980-05-01

    Pressurized ion exchange on Dowex 50W-X8 and 50W-X12 resins was investigated using elution techniques to determine distribution ratios for copper, nickel, and cobalt complexes contained in ammonium carbonate solution, a mixture which approximates the waste liquor from the Caron nickel recovery process. Results were determined for different feed concentrations, as well as for different concentrations and pH values of the ammonium carbonate eluant. Distribution ratios were compared with those previously obtained from a continuous annular chromatographic system. Separation of copper and nickel was not conclusively observed at any of the conditions examined.

  3. Nanoparticles of nickel hexacyanoferrate; Nanoparticulas de hexacianoferrato de niquel

    Energy Technology Data Exchange (ETDEWEB)

    Bicalho, U.O.; Santos, D.C.; Silvestrini, D.R.; Trama, B.; Carmo, D.R. do, E-mail: docarmo@dfq.feis.unesp.br [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Ilha Solteira, SP (Brazil). Faculdade de Engenharia

    2014-07-01

    Nanoparticles of nickel hexacyanoferrate (NHNi) were prepared in three medium (aqueous, formamide and aqueous/formamide). The materials were characterized by infrared spectroscopy (FT-IR), X-ray diffraction (XRD), electronica spectroscopy in the ultraviolet-visible (UV-Vis) region and also by cyclic voltammetry (CV). By spectroscopic analysis of X-ray diffraction was possible to estimate the size of the particles obtained by the Scherrer equation. The graphite paste electrodes containing nanoparticles of nickel hexacyanoferrate means formamide was sensitive to different concentrations of Dipyrone. (author)

  4. The dynamic ocean biological pump: Insights from a global compilation of particulate organic carbon, CaCO3, and opal concentration profiles from the mesopelagic

    Science.gov (United States)

    Lam, Phoebe J.; Doney, Scott C.; Bishop, James K. B.

    2011-09-01

    We have compiled a global data set of 62 open ocean profiles of particulate organic carbon (POC), CaCO3, and opal concentrations collected by large volume in situ filtration in the upper 1000 m over the last 30 years. We define concentration-based metrics for the strength (POC concentration at depth) and efficiency (attenuation of POC with depth in the mesopelagic) of the biological pump. We show that the strength and efficiency of the biological pump are dynamic and are characterized by a regime of constant and high transfer efficiency at low to moderate surface POC and a bloom regime where the height of the bloom is characterized by a weak deep biological pump and low transfer efficiency. The variability in POC attenuation length scale manifests in a clear decoupling between the strength of the shallow biological pump (e.g., POC at the export depth) and the strength of the deep biological pump (POC at 500 m). We suggest that the paradigm of diatom-driven export production is driven by a too restrictive perspective on upper mesopelagic dynamics. Indeed, our full mesopelagic analysis suggests that large, blooming diatoms have low transfer efficiency and thus may not export substantially to depth; rather, our analysis suggests that ecosystems characterized by smaller cells and moderately high %CaCO3 have a high mesopelagic transfer efficiency and can have higher POC concentrations in the deep mesopelagic even with relatively low surface or near-surface POC. This has negative implications for the carbon sequestration prospects of deliberate iron fertilization.

  5. Nickel Hydrogen Battery Expert System

    Science.gov (United States)

    Johnson, Yvette B.; Mccall, Kurt E.

    1992-01-01

    The Nickel Cadmium Battery Expert System-2, or 'NICBES-2', which was used by the NASA HST six-battery testbed, was subsequently converted into the Nickel Hydrogen Battery Expert System, or 'NICHES'. Accounts are presently given of this conversion process and future uses being contemplated for NICHES. NICHES will calculate orbital summary data at the end of each orbit, and store these files for trend analyses and rules-generation.

  6. Nickel Ore Dispersion Evaluation and Consequences in Flotation Process

    Science.gov (United States)

    de São José, Fábio; Imbelloni, Alaine Moreira; Nogueira, Francielle Câmara; Pereira, Carlos Alberto

    2016-04-01

    Nickel ore dispersion before flotation using different reagents was investigated on a bench scale to improve metallurgical recovery and selectivity. The nickel ore had a content of 0.8 pct nickel and 14.5 pct MgO. A positive linear correlation between MgO and Ni was found. Carboxy methyl cellulose, both pure and combined with Na2CO3, was the best dispersant used. The most efficient collector was potassium amyl xanthate combined with mercaptobenzothiazole, and the addition of xanthate was decisive for this good result because it is normally more stable in the pH range used in the tests. A pH change from 7 to 9 resulted in a metal recovery increase of 49.3 pct, together with an increase of 6.25 pct of MgO in the concentrate.

  7. Evaluating vertical concentration profile of carbon source released from slow-releasing carbon source tablets and in situ biological nitrate denitrification activity

    Science.gov (United States)

    Yeum, Y.; HAN, K.; Yoon, J.; Lee, J. H.; Song, K.; Kang, J. H.; Park, C. W.; Kwon, S.; Kim, Y.

    2017-12-01

    Slow-releasing carbon source tablets were manufactured during the design of a small-scale in situ biological denitrification system to reduce high-strength nitrate (> 30 mg N/L) from a point source such as livestock complexes. Two types of slow-releasing tablets, precipitating tablet (PT, apparent density of 2.0 g/mL) and floating tablet (FT), were prepared to achieve a vertically even distribution of carbon source (CS) in a well and an aquifer. Hydroxypropyl methylcellulose (HPMC) was used to control the release rate, and microcrystalline cellulose pH 101 (MCC 101) was added as a binder. The #8 sand was used as a precipitation agent for the PTs, and the floating agents for the FTs were calcium carbonate and citric acid. FTs floated within 30 min. and remained in water because of the buoyance from carbon dioxide, which formed during the acid-base reaction between citric acid and calcium carbonate. The longevities of PTs with 300 mg of HPMC and FTs with 400 mg of HPMC were 25.4 days and 37.3 days, respectively. We assessed vertical CS profile in a continuous flowing physical aquifer model (release test, RT) and its efficiency on biological nitrate denitrification (denitrification test, DT). During the RT, PTs, FTs and a tracer (as 1 mg rhodamine B/L) were initially injected into a well of physical aquifer model (PAM). Concentrations of CS and the tracer were monitored along the streamline in the PAM to evaluate vertical profile of CS. During the DT, the same experiment was performed as RT, except continuous injection of solution containing 30 mg N/L into the PAM to evaluate biological denitrification activity. As a result of RT, temporal profiles of CS were similar at 3 different depths of monitoring wells. These results suggest that simultaneous addition of PT and FT be suitable for achieving a vertically even distribution of the CS in the injection well and an aquifer. In DT, similar profile of CS was detected in the injection well, and nitrate was biologically

  8. Improvement of solvents for chemical decontamination: nickel ferrites removal

    International Nuclear Information System (INIS)

    Figueroa, Carlos A.; Morando, Pedro J.; Blesa, Miguel A.

    1999-01-01

    Carboxylic acids are usually included in commercial solvents for the chemical cleaning and decontamination of metal surfaces from the oxide layers grown and/or deposited from high temperature water by corrosive process. In particular oxalic acid is included in second path of AP-Citrox method. However, in some cases, their use shows low efficiency. This fact is attributed to the special passivity of the mixed oxides as nickel ferrites. This work reports a kinetic study of dissolution of a synthetic nickel ferrite (NiFe 2 O 4 ) confronted with simple oxides (NiO and Fe 2 O 3 ) in mineral acids and oxalic acid. The dissolution factor and reaction rate were determined in several conditions (reactive concentrations, pH and added ferrous ions). Experimental data of dissolution (with and without Fe(II) added) show a congruent kinetic regime. Pure nickel oxide (NiO) is rather resistant to the attack by oxalic acid solutions, and ferrous ions do not accelerate dissolution. In fact, nickel oxide dissolves better by oxidative attack that takes advantage of the higher lability of Ni 3+ . It may be concluded that oxalic acid operates to dissolve iron, and the ensuing disruption of the solid framework accelerates the release of nickel. Our results point to use more reactive solvents in iron from mixed oxides and to the possibility of using one stage decontamination method. (author)

  9. Sensitivity and specificity of the nickel spot (dimethylglyoxime) test.

    Science.gov (United States)

    Thyssen, Jacob P; Skare, Lizbet; Lundgren, Lennart; Menné, Torkil; Johansen, Jeanne D; Maibach, Howard I; Lidén, Carola

    2010-05-01

    The accuracy of the dimethylglyoxime (DMG) nickel spot test has been questioned because of false negative and positive test reactions. The EN 1811, a European standard reference method developed by the European Committee for Standardization (CEN), is fine-tuned to estimate nickel release around the limit value of the EU Nickel Directive from products intended to come into direct and prolonged skin contact. Because assessments according to EN 1811 are expensive to perform, time consuming, and may destruct the test item, it should be of great value to know the accuracy of the DMG screening test. To evaluate the sensitivity and specificity of the DMG test. DMG spot testing, chemical analysis according to the EN 1811 reference method, and X-ray fluorescence spectroscopy (XRF) were performed concomitantly on 96 metallic components from earrings recently purchased in San Francisco. The sensitivity of the DMG test was 59.3% and the specificity was 97.5% based on DMG-test results and nickel release concentrations determined by the EN 1811 reference method. The DMG test has a high specificity but a modest sensitivity. It may serve well for screening purposes. Past exposure studies may have underestimated nickel release from consumer items.

  10. Biosorption of nickel with barley straw.

    Science.gov (United States)

    Thevannan, Ayyasamy; Mungroo, Rubeena; Niu, Catherine Hui

    2010-03-01

    Wastewater containing nickel sulphate generated from a nickel plating industry is of great concern. In the present work, biosorption of nickel by barley straw from nickel sulphate solution was investigated. Nickel uptake at room temperature (23+/-0.5 degrees C) was very sensitive to solution pH, showing a better uptake value at a pH of 4.85+/-0.10 among the tested values. The nickel biosorption isotherm fitted well the Langmuir equation. When the ionic strength (IS) of the solution was increased from less than 0.02-0.6M, nickel uptake was reduced to 12% of that obtained at IS of less than 0.02 M. Barley straw showed a higher nickel uptake (0.61 mmol/g) than acid washed crab shells (0.04 mmol/g), demonstrating its potential as an adsorbent for removal of nickel. Copyright (c) 2009 Elsevier Ltd. All rights reserved.

  11. EPIDEMIOLOGICAL AND PATHOGENETIC ASPECTS OF NICKEL POISONING

    Directory of Open Access Journals (Sweden)

    Vladmila Bojanic

    2007-04-01

    Full Text Available Nickel is widely distributed in the environment. High consumption of nickel containing products inevitably leads to environmental pollution by nickel and its derivatives at all stages of production, utilization, and disposal.Human exposure to nickel occurs primarily via inhalation and ingestion and is particularly high among nickel metallurgy workers. In addition, implantation of nickel-containing endoprostheses and iatrogenic administration of nickel-contaminated medica-tions leads to significant parenteral exposures. Exposure to nickel compounds can produce a variety of adverse effects on human health. Nickel allergy in the form of contact dermatitis is the most common reaction.A frontal headache, vertigo, nausea, vomiting, insomnia, and irritability are the most common signs of acute poisoning with nickel compounds. The respiratory tract, kidneys and liver suffer the most significant changes like nickel pneumoconiosis, chronic rhinitis and sinonasal tumors and transitory nephropathy. Although the accumulation of nickel in the body through chronic exposure can lead to lung fibrosis, cardiovascular and kidney diseases, the most serious concerns relate to nickel’s carcinogenic activity. Nickel compounds are carcinogenic to humans and metallic nickel is possibly carcinogenic to humans.

  12. Body Composition, Lipid Profile, Adipokine Concentration, and Antioxidant Capacity Changes during Interventions to Treat Overweight with Exercise Programme and Whole-Body Cryostimulation

    Directory of Open Access Journals (Sweden)

    Anna Lubkowska

    2015-01-01

    Full Text Available The aim of this study was to determine the effect of six-month-long physical exercise programme with a two-time exposure to whole-body cryostimulation (WBC in 20 sessions on antioxidant enzyme activities, lipid profile, and body composition changes in obese people (30 adult subjects; BMI = 30.39 ± 4.31 kg/m2. Blood samples were taken before the programme, one month following the exercise programme, before and after the first WBC treatment, six months following the exercise programme, after the second WBC treatment, and finally one month after the intervention. Six months of moderate aerobic activity combined with WBC did not change body mass or fat and lean body mass percentages, or circulating adiponectin, leptin, and resistin concentrations. In response to intervention a significant decrease in the level of low-density lipoprotein and triglycerides was observed, with a slight increase in high-density lipoprotein concentration. The nature of changes in the activity of respective antioxidant enzymes was not identical. After one month of increased physical activity, a significant decrease in superoxide dismutase, catalase, and glutathione reductase activities was observed (13%, 8%, and 70%, resp.. The SOD activity increased significantly after successive whole-body cryostimulation sessions. As regards catalase, a significant progressive decrease in its activity was observed.

  13. Microplasma synthesis on aluminum with additions of iron and nickel soluble complexes in electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Rogov, A.B., E-mail: alex-lab@bk.ru [Nikolaev Institute of Inorganic Chemistry. 3, Acad. Lavrentiev Ave, Novosibirsk, 630090 (Russian Federation); Mironov, I.V.; Terleeva, O.P.; Slonova, A.I. [Nikolaev Institute of Inorganic Chemistry. 3, Acad. Lavrentiev Ave, Novosibirsk, 630090 (Russian Federation)

    2012-10-01

    Highlights: Black-Right-Pointing-Pointer Alkaline homogeneous electrolyte with transition metals complexes. Black-Right-Pointing-Pointer Coatings contain metallic iron, nickel and their oxides in alumina-silica matrix. Black-Right-Pointing-Pointer Effect of Fe/Ni ratio on coatings properties and process characteristics. - Abstract: The microplasma synthesis of coatings containing iron and nickel from homogeneous electrolytes has been studied. For stabilization of transition metals in solution, it is proposed to use chelation. It was found that the synthesis of coatings using alternating current leads to the formation of metallic iron and nickel particles in addition to oxide phases. The iron and nickel complexes concentrations ratio in the electrolyte correlates with the coatings composition. Obtained coatings have been studied by scanning electron microscopy with X-ray microanalyser and by X-ray diffraction with Cu and Mo radiation. The metal content in the coating was determined spectrophotometrically from the absorption of iron thiocyanate complexes and nickel dimethylglyoxime complex.

  14. The EU Nickel Directive revisited--future steps towards better protection against nickel allergy

    DEFF Research Database (Denmark)

    Thyssen, Jacob P; Uter, Wolfgang; McFadden, John

    2011-01-01

    In July 2001, the EU Nickel Directive came into full force to protect European citizens against nickel allergy and dermatitis. Prior to this intervention, Northern European governments had already begun to regulate consumer nickel exposure. According to part 2 of the EU Nickel Directive and the D......In July 2001, the EU Nickel Directive came into full force to protect European citizens against nickel allergy and dermatitis. Prior to this intervention, Northern European governments had already begun to regulate consumer nickel exposure. According to part 2 of the EU Nickel Directive...... and the Danish nickel regulation, consumer items intended to be in direct and prolonged contact with the skin were not allowed to release more than 0.5 µg nickel/cm2/week. It was considered unlikely that nickel allergy would disappear altogether as a proportion of individuals reacted below the level defined...

  15. Nickel exposure is associated with the prevalence of type 2 diabetes in Chinese adults.

    Science.gov (United States)

    Liu, Gang; Sun, Liang; Pan, An; Zhu, Mingjiang; Li, Zi; ZhenzhenWang, Zhenzhen; Liu, Xin; Ye, Xingwang; Li, Huaixing; Zheng, He; Ong, Choon Nam; Yin, Huiyong; Lin, Xu; Chen, Yan

    2015-02-01

    Nickel exposure can induce hyperglycaemia in rodents, but little is known about its association with abnormal glucose metabolism in humans. We aimed to investigate the association of nickel exposure with the prevalence of type 2 diabetes in Chinese adults. A total of 2115 non-institutionalized men and women aged 55 to 76 years from Beijing and Shanghai were included, and urinary nickel concentration was assessed by inductively coupled plasma mass spectroscopy. The prevalence of type 2 diabetes was compared across urinary nickel quartiles. Fasting plasma glucose, insulin, lipids, C-reactive protein and glycated haemoglobin A1c, as well as urinary albumin and creatinine were measured. The median concentration of urinary nickel was 3.63 mg/l (interquartile range: 2.29–5.89 mg/l), and the prevalence of diabetes was 35.3% (747 cases/2115 persons). Elevated levels of urinary nickel were associated with higher fasting glucose, glycated haemoglobin A1c, insulin and homeostatic model assessment of insulin resistance (all Pnickel quartiles were 1.27 (0.97–1.67), 1.78 (1.36–2.32) and 1.68 (1.29–2.20), respectively (referencing to 1.00), after multivariate adjustment including lifestyle factors, body mass index and family history of diabetes (P for trend nickel concentration is associated with elevated prevalence of type 2 diabetes in humans.

  16. Extracellular synthesis and characterization of nickel oxide nanoparticles from Microbacterium sp. MRS-1 towards bioremediation of nickel electroplating industrial effluent.

    Science.gov (United States)

    Sathyavathi, S; Manjula, A; Rajendhran, J; Gunasekaran, P

    2014-08-01

    In the present study, a nickel resistant bacterium MRS-1 was isolated from nickel electroplating industrial effluent, capable of converting soluble NiSO4 into insoluble NiO nanoparticles and identified as Microbacterium sp. The formation of NiO nanoparticles in the form of pale green powder was observed on the bottom of the flask upon prolonged incubation of liquid nutrient medium containing high concentration of 2000ppm NiSO4. The properties of the produced NiO nanoparticles were characterized. NiO nanoparticles exhibited a maximum absorbance at 400nm. The NiO nanoparticles were 100-500nm in size with unique flower like structure. The elemental composition of the NiO nanoparticles was 44:39. The cells of MRS-1 were utilized for the treatment of nickel electroplating industrial effluent and showed nickel removal efficiency of 95%. Application of Microbacterium sp. MRS-1 would be a potential bacterium for bioremediation of nickel electroplating industrial waste water and simultaneous synthesis of NiO nanoparticles. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Relationship between nickel allergy and diet

    OpenAIRE

    Sharma Ashimav

    2007-01-01

    Nickel is a ubiquitous trace element and it occurs in soil, water, air and of the biosphere. It is mostly used to manufacture stainless steel. Nickel is the commonest cause of metal allergy. Nickel allergy is a chronic and recurring skin problem; females are affected more commonly than males. Nickel allergy may develop at any age. Once developed, it tends to persist life-long. Nickel is present in most of the dietary items and food is considered to be a major source of nickel exposure for the...

  18. Effects of dietary inclusion of high concentrations of crude glycerin on meat quality and fatty acid profile of feedlot fed Nellore bulls.

    Directory of Open Access Journals (Sweden)

    Eric H C B van Cleef

    Full Text Available Crude glycerin, the main by-product of biodiesel production, can replace dietary energy sources, such as corn. The objective of this study was to evaluate the inclusion of up to 30% of crude glycerin in dry matter (DM of the total diets, and its effects on meat quality parameters of feedlot Nellore bulls. Thirty animals (227.7 ± 23.8 kg body weight; 18 months old were housed in individual pens and fed 5 experimental diets, containing 0, 7.5, 15, 22.5 or 30% crude glycerin (DM basis. After 103 d (21 d adaptation animals were slaughtered and the Longissimus muscle was collected. The characteristics assessed were chemical composition, fatty acid profile, cholesterol, shear force, pH, color, water-holding capacity, cooking loss and sensory properties. The increasing inclusion of crude glycerin in the diets did not affect the chemical composition of the Longissimus muscle (P > 0.10. A quadratic effect was observed when levels of crude glycerin were increased, on the concentration of pentadecanoic, palmitoleic and eicosenoic fatty acids in meat (P < 0.05, and on the activity of the delta-9 desaturase 16 and delta-9 desaturase 18 enzymes (P < 0.05. The addition of crude glycerin increased the gamma linolenic fatty acid concentration (P < 0.01, and altered the monounsaturated fatty acids in Longissimus muscle of animals (Pquad. < 0.05. Crude glycerin decreased cholesterol content in meat (P < 0.05, and promoted higher flavor score and greasy intensity perception of the meat (P < 0.01. The inclusion of up to 30% crude glycerin in Nellore cattle bulls`diets (DM basis improves meat cholesterol and sensory attributes, such as flavor, without affecting significantly the physical traits, the main fatty acid concentrations and the chemical composition.

  19. Organophosphate esters and phthalate esters in human hair from rural and urban areas, Chongqing, China: Concentrations, composition profiles and sources in comparison to street dust.

    Science.gov (United States)

    He, Ming-Jing; Lu, Jun-Feng; Ma, Jing-Ye; Wang, Huan; Du, Xiao-Fan

    2018-06-01

    Human hair and street dust from rural and urban areas in Chongqing were collected to analyze Organophosphate esters (OPEs) and phthalate esters (PAEs). Concentrations of OPEs in urban hair were significantly higher than those in rural hair, whereas PAEs concentrations in rural hair were significantly higher than those in urban hair. Different composition patterns of OPEs were observed in rural and urban hair, where tris (2-chloroisopropyl) phosphate (TCIPP), tris (butyl) phosphate (TNBP) and triphenyl phosphate (TPHP) were the dominating analogues in rural hair, accounting for 62.1% of the OPEs burden, and tris (methylphenyl) phosphate (TMPP) exhibited a high contribution in urban hair, responsible for 51.3% of total OPEs, which differed from the composition profiles in corresponding street dust. Analogous composition patterns of PAEs were found in hair of both areas. Di-(2-ethylhexyl) phthalate (DEHP), dibutyl phthalate (DNBP), diisobutyl phthalate (DIBP) and diethyl phthalate (DEP) were the most abundant analogues in hair samples, while DEHP was the predominant analogue in dust samples. No clear tendency was obtained between the increasing ages and the concentrations of both compounds. Most OPEs and PAEs congeners showed significantly positive correlation with one another in rural hair. On the contrary, different correlation patterns were observed in urban hair for OPEs and PAEs, indicating multiple or additional sources existed in urban areas. Significant correlations of OPEs and PAEs were found between hair and corresponding street dust samples, but poor correlations of OPEs and PAEs were observed between rural hair and rural indoor dust, suggesting that street dust may be a predominant exogenous source for human exposure to OPEs and PAEs in this area. Copyright © 2018 Elsevier Ltd. All rights reserved.

  20. Investigation of some characteristics for nickel ferrite prepared by aerosolization

    International Nuclear Information System (INIS)

    El-Masry, M.A.A.; Khater, E.M.H.; Gaber, A.

    1997-01-01

    In this report some characteristics of nickel ferrite powder prepared through the aerosolization technique by atomization were investigated. It was found that both concentration of the solution and temperature affect the powder characteristics. The increase of the pyrolysis temperature increases both the degree of crystallinity and particle size but decreases the specific surface area. Lowering the concentration of the solution. raises the decomposition efficiency and produces lower yield with smaller particle size. 9 figs., 1 tab

  1. Chemical vapor deposition of aluminide coatings on iron, nickel and superalloys

    International Nuclear Information System (INIS)

    John, John T.; De, P.K.; Dubey, Vivekanand; Srinivasa, Raman

    2009-08-01

    Aluminide coatings are a class of intermetallic coatings applied on nickel and cobalt base superalloys and steels to protect them from different forms of environmental degradation at high temperatures. In this report a CVD system that can produce the aluminide coatings on iron, nickel and nickel base alloys has been described and the result of chemical vapor deposition of aluminide coatings on iron specimens, their characterization, and property evaluation have been presented. The CVD system consists of an AlCl 3 bath, a stainless steel retort as a hot-wall reacto, cold traps and vacuum system. Aluminium chloride vapor was carried in a stream of hydrogen gas at a flow rate of 150 SCCM (standard cubic centimeter per minute) into the CVD reactor maintained in the temperature range of 1173 - 1373 K and at a pressure of 1.33 kPa (10 Torr). Aluminum deposition takes place from aluminium subchlorides produced by reaction between AlCl 3 and pure aluminum kept in the CVD reactor. The aluminum diffuses into the iron samples and iron aluminide phases are formed at the surface. The coatings were shining bright and showed good adherence to the substrate. The coatings consisted of FeAl phase over a wide range of experimental conditions. The growth kinetics of the coating followed a parabolic rate law and the mean activation energy was 212 ±16 kJ/mol. Optical microscopic studies on the transverse section of the coating showed that the aluminide coating on iron consisted of two layers. The top layer had a thickness in the range of 20-50 μm, and the under layer had thickness ranging from 35 to 250 μm depending on coating temperature in two hours. The thickness of the aluminide layer increased with coating duration and temperature. Electron microprobe studies (EPMA) showed that the aluminum concentration decreased steadily as distance from the surface increased. TEM studies showed that the outer most layer had a B2 order (of the FeAl phase), which extended even into the under

  2. Modeling of filling gas centrifuge cascade for nickel isotope separation by feed flow input to different stages

    Directory of Open Access Journals (Sweden)

    Orlov Alexey A.

    2017-01-01

    Full Text Available The article presents results of research filling gas centrifuge cascade by process gas fed into different stages. The modeling of filling cascade was done for nickel isotope separation. Analysis of the research results shows that nickel isotope concentrations of light and heavy fraction flows after filling cascade depend on feed stage number.

  3. Polychlorinated biphenyl concentrations, congener profiles, and ratios in the fat tissue, eggs, and plasma of snapping turtles (Chelydra s. serpentina) from the Ohio Basin of Lake Erie, USA.

    Science.gov (United States)

    Dabrowska, H; Fisher, S W; Estenik, J; Kidekhel, R; Stromberg, P

    2006-08-01

    Concentrations and profiles of polychlorinated biphenyls (PCBs) were determined in three tissues of adult snapping turtles (Chelydra serpentina serpentina) from six locations in the Ohio Basin of Lake Erie to characterize tissue variation and geographic trends. The locations included the Ohio Areas of Concern, i.e., the Ashtabula, Black, and Maumee Rivers; the Ottawa River near Toledo; and two reference sites. Mean total PCBs were greatest in turtles from the Ottawa River followed by the Maumee, Ashtabula, and Black Rivers. All three types of samples-fat tissue (FT), eggs, and plasma-showed the same geographic trend in PCB levels. On a wet-weight basis, mean concentrations ranged from 2,148 to 18,669 ng/g in FT, from 183 to 3,683 ng/g in eggs, and from 18 to 201 ng/g in plasma. Across all sites, total PCB concentrations between the tissues were significantly correlated (0.001 40 congeners (0.001 < p < 0.05). The distribution ratios determined for these congeners from the slope of the regression lines averaged 1.235 +/- 0.279, 0.430 +/- 0.170, and 0.387 +/- 0.115, respectively. The plasma wet weight-FT lipid-normalized concentration ratios for these congeners averaged 0.012 +/- 0.006. Both egg-FT and plasma wet weight-FT lipid-normalized ratios regressed against log K(ow) showed significant decreases, with increasing log K(ow), indicating greater accumulation of highly chlorinated congeners in FT than in other compartments. The estimated 2,3,7,8-tetrachlorodibenzo-p-dioxin toxic equivalents ranged from 0.007 ng/g at reference sites to 0.060 ng/g at contaminated sites and from 0.099 to 1.992 ng/g in plasma and eggs, respectively. In both plasma and eggs, coplanar-CBs were the major contributors to total toxic equivalents (TEQs). Eggs from all contaminated sites had TEQs that exceeded the lowest observed effect level TEQs proposed for bald eagle chicks, in addition to high SigmaPCB levels at some of these sites, especially the Ottawa and Maumee River sites, indicate

  4. Enhancement of porous silicon photoluminescence by electroless deposition of nickel

    Energy Technology Data Exchange (ETDEWEB)

    Amdouni, S. [Unité de nanomatériaux et photonique, Université El Manar, Faculté des Sciences de Tunis, Département de Physique, 2092 El Manar, Tunis Tunisia (Tunisia); Rahmani, M., E-mail: rahmanimehdi79@yahoo.com [Unité de nanomatériaux et photonique, Université El Manar, Faculté des Sciences de Tunis, Département de Physique, 2092 El Manar, Tunis Tunisia (Tunisia); Zaïbi, M.-A [Unité de nanomatériaux et photonique, Université El Manar, Faculté des Sciences de Tunis, Département de Physique, 2092 El Manar, Tunis Tunisia (Tunisia); Ecole Nationale Supérieure des Ingénieurs de Tunis, Université de Tunis, 5 Avenue Taha Hussein, 1008 Tunis (Tunisia); Oueslati, M. [Unité de nanomatériaux et photonique, Université El Manar, Faculté des Sciences de Tunis, Département de Physique, 2092 El Manar, Tunis Tunisia (Tunisia)

    2015-01-15

    Nickel-porous silicon nanocomposites (PS/Ni) are elaborated by an electroless deposition method using NiCl{sub 2} aqueous solution. The presence of nickel ions in the porous layer is confirmed by Fourier Transformed InfraRed spectroscopy (FTIR) and Raman spectroscopy. The photoluminescence (PL) spectra of PS/Ni, prepared at different electroless durations (t{sub edp}), are analyzed. A remarkable enhancement in the integrated PL intensity of PS containing nickel was observed. The lower t{sub edp} favor the deposition of nickel in PS, hence the silicon dangling bonds at the porous surface are quenched and this was increased the PL intensity. However, for the longer t{sub edp}, the PL intensity has been considerably decreased due to the destruction of some Si nanocrystallites. The PL spectra of PS/Ni, for t{sub edp} less than 8 min, show a multiband profile indicating the creation of new luminescent centers by Ni elements which induces a strong modification in the emission mechanisms. - Highlights: • Deposition of Ni ions into porous silicon (PS) layer using the electroless method. • Formation of Ni–O bonds on the porous layer. • The photoluminescence (PL) intensity of PS is enhanced after Ni deposition. • The increase of the PL is due to the contribution of radiative centers related to Ni.

  5. Nickel toxicity on seed germination and growth in radish (Raphanus sativus) and its recovery using copper and boron.

    Science.gov (United States)

    Yadav, Shiv Shankar; Shukla, Rajni; Sharma, Y K

    2009-05-01

    Effect of various concentrations of nickel (100, 200, 500 and 1000 microM) and recovery treatments of boron (50 and 100 microM) and copper (15 and 75 microM) each with 200 microM and 500 microM of nickel on germination, growth, biomass, chlorophyll, carotenoids, pheophytin, amylase, protein, sugar as well as activity of catalase and peroxidase were studied in radish (Raphanus sativus cv. Early menu) seedlings. Nickel treatments caused a considerable reduction in germination percentage, growth and biomass. The different pigments were also decreased with nickel treatments. However boron addition with nickel recovered the negative effect on pigment contents. Among biochemical estimations, amylase activity and total proteins were found to be reduced in nickel treatments. Peroxidase and catalase activity were induced other than higher total sugar with nickel treatments. The combination of nickel with boron resulted into increased protein contents. This combination also reduced the catalase and peroxidase activity. The influence of nickel with copper failed to produce significant recovery except 200 microM nickel in combination with 15 microM copper with regard to catalase and peroxidase activity. The effect of nickel on hydrolyzing enzyme amylase was observed to be inhibitory resulting into poor germination followed by poor seedlings growth. The stress protecting enzymes peroxidase and catalase seem to be induced under the influence of nickel, and providing protection to the seedlings. The application of boron with nickel showed improved germination and growth. The level of catalase and peroxidase were found to be significantly reduced showing normal growth and biomass of seedlings.

  6. Nickel hydrogen battery cell storage matrix test

    Science.gov (United States)

    Wheeler, James R.; Dodson, Gary W.

    1993-01-01

    Test were conducted to evaluate post storage performance of nickel hydrogen cells with various design variables, the most significant being nickel precharge versus hydrogen precharge. Test procedures and results are presented in outline and graphic form.

  7. Nickel exposure and plasma levels of biomarkers for assessing oxidative stress in nickel electroplating workers.

    Science.gov (United States)

    Tsao, Yu-Chung; Gu, Po-Wen; Liu, Su-Hsun; Tzeng, I-Shiang; Chen, Jau-Yuan; Luo, Jiin-Chyuan John

    2017-07-01

    The mechanism of nickel-induced pathogenesis remains elusive. To examine effects of nickel exposure on plasma oxidative and anti-oxidative biomarkers. Biomarker data were collected from 154 workers with various levels of nickel exposure and from 73 controls. Correlations between nickel exposure and oxidative and anti-oxidative biomarkers were determined using linear regression models. Workers with a exposure to high nickel levels had significantly lower levels of anti-oxidants (glutathione and catalase) than those with a lower exposure to nickel; however, only glutathione showed an independent association after multivariable adjustment. Exposure to high levels of nickel may reduce serum anti-oxidative capacity.

  8. Electrocatalytic Study of Paracetamol at a Single-Walled Carbon Nanotube/Nickel Nanocomposite Modified Glassy Carbon Electrode

    Directory of Open Access Journals (Sweden)

    Koh Sing Ngai

    2015-01-01

    Full Text Available A rapid, simple, and sensitive method for the electrochemical determination of paracetamol was developed. A single-walled carbon nanotube/nickel (SWCNT/Ni nanocomposite was prepared and immobilized on a glassy carbon electrode (GCE surface via mechanical attachment. This paper reports the voltammetry study on the effect of paracetamol concentration, scan rate, pH, and temperature at a SWCNT/Ni-modified electrode in the determination of paracetamol. The characterization of the SWCNT/Ni/GCE was performed by cyclic voltammetry. Variable pressure scanning electron microscopy (VPSEM and energy dispersive X-ray (EDX spectrometer were used to examine the surface morphology and elemental profile of the modified electrode, respectively. Cyclic voltammetry showed significant enhancement in peak current for the determination of paracetamol at the SWCNT/Ni-modified electrode. A linear calibration curve was obtained for the paracetamol concentration between 0.05 and 0.50 mM. The SWCNT/Ni/GCE displayed a sensitivity of 64 mA M−1 and a detection limit of 1.17 × 10−7 M in paracetamol detection. The proposed electrode can be applied for the determination of paracetamol in real pharmaceutical samples with satisfactory performance. Results indicate that electrodes modified with SWCNT and nickel nanoparticles exhibit better electrocatalytic activity towards paracetamol.

  9. Assessment of metal, trace and rare earth element concentrations in a sedimentary profile from Ponte Nova reservoir, Sao Paulo state, Brazil, by NAA

    Energy Technology Data Exchange (ETDEWEB)

    Rocha, Flavio R.; Bordon, Isabella C.C.L.; Silva, Paulo S.C.; Favaro, Deborah I.T., E-mail: flavio@baquara.com, E-mail: defavaro@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Silva, Sharlleny A.; Franklin, Robson L.; Ferreira, Francisco J., E-mail: shasilva@sp.gov.br, E-mail: rfranklin@sp.gov.br [Companhia Ambiental do Estado de Sao Paulo (ELAI/CETESB), SP (Brazil). Setor de Quimica Inorganica

    2015-07-01

    Ponte Nova reservoir, located in the upper basin of the Tiete River in the southern region of Sao Paulo State, covers an area of 25.7 km{sup 2} and drains an area of 320 km{sup 2}. It was built in 1972 to control the rivers flow in the Metropolitan Region of Sao Paulo (MRSP) and water supply. A 30 cm sediment core was collected in the dam in August 2014, sliced at every 2.5 cm. Instrumental neutron activation analysis (INAA) was applied to the sediment samples to determine some major (Fe, K and Na), trace (As, Ba, Br, Co, Cr, Cs, Hf, Rb, Sb, Sc, Ta, Tb, Th, U and Zn) and rare earth (Ce, Eu, La, Lu, Nd, Sm, Tb and Yb) elements. The enrichment factor (EF) and Igeo were applied to the results by using NASC (North American Shale Composite) as reference values for sediment contamination index assessment. An EF>1.5 was obtained for As, Hf, Rb, Ta, Th, U, and rare earths Ce, Eu, La, Nd and Sm when NASC values were used, but only for Br, when the last layer concentration values were used as reference values. Similar results were obtained for the Igeo index. For semi-metal As and metals Cr and Zn concentration values were compared to oriented values from Environmental Canada (TEL and PEL) only Cr exceeded TEL value in some slices of the profile. These results may indicate that there is no anthropogenic contribution for the elements analyzed in this reservoir. Multivariate statistical analysis was applied to the results. (author)

  10. Assessment of metal, trace and rare earth element concentrations in a sedimentary profile from Ponte Nova reservoir, Sao Paulo state, Brazil, by NAA

    International Nuclear Information System (INIS)

    Rocha, Flavio R.; Bordon, Isabella C.C.L.; Silva, Paulo S.C.; Favaro, Deborah I.T.; Silva, Sharlleny A.; Franklin, Robson L.; Ferreira, Francisco J.

    2015-01-01

    Ponte Nova reservoir, located in the upper basin of the Tiete River in the southern region of Sao Paulo State, covers an area of 25.7 km 2 and drains an area of 320 km 2 . It was built in 1972 to control the rivers flow in the Metropolitan Region of Sao Paulo (MRSP) and water supply. A 30 cm sediment core was collected in the dam in August 2014, sliced at every 2.5 cm. Instrumental neutron activation analysis (INAA) was applied to the sediment samples to determine some major (Fe, K and Na), trace (As, Ba, Br, Co, Cr, Cs, Hf, Rb, Sb, Sc, Ta, Tb, Th, U and Zn) and rare earth (Ce, Eu, La, Lu, Nd, Sm, Tb and Yb) elements. The enrichment factor (EF) and Igeo were applied to the results by using NASC (North American Shale Composite) as reference values for sediment contamination index assessment. An EF>1.5 was obtained for As, Hf, Rb, Ta, Th, U, and rare earths Ce, Eu, La, Nd and Sm when NASC values were used, but only for Br, when the last layer concentration values were used as reference values. Similar results were obtained for the Igeo index. For semi-metal As and metals Cr and Zn concentration values were compared to oriented values from Environmental Canada (TEL and PEL) only Cr exceeded TEL value in some slices of the profile. These results may indicate that there is no anthropogenic contribution for the elements analyzed in this reservoir. Multivariate statistical analysis was applied to the results. (author)

  11. Oral nickel exposure may induce Type I hypersensitivity reaction in nickel-sensitized subjects.

    Science.gov (United States)

    Büyüköztürk, Suna; Gelincik, Aslı; Ünal, Derya; Demirtürk, Mustafa; Çelik, Dolay Damla; Erden, Sacide; Çolakoğlu, Bahattin; Erdem Kuruca, Serap

    2015-05-01

    Little is known about the clinical and immunological changes in the nickel allergic patients with systemic symptoms. We aimed to evaluate T helper cell responses of patients with different clinical presentations due to nickel. Patients having various allergic symptoms and positive patch test results to nickel and 20 controls underwent skin prick tests with nickel. IL-10, IL-4, IL-5 and IFN-gamma were measured in the culture supernatants of PBMC stimulated by nickel during lymphocyte proliferation test (LTT). 69 patients (56 female, mean age: 49.2 ± 13.1), 97% having nickel containing dental devices and 20 controls (8 female, mean age 34.9 ± 12.06) were evaluated. Skin prick tests with nickel were positive in 70% of the patients (pnickel. Nickel containing dental alloys and oral nickel intake seem to trigger systemic symptoms in previously nickel sensitized patients. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. The EU Nickel Directive revisited--future steps towards better protection against nickel allergy

    DEFF Research Database (Denmark)

    Thyssen, Jacob P; Uter, Wolfgang; McFadden, John

    2011-01-01

    In July 2001, the EU Nickel Directive came into full force to protect European citizens against nickel allergy and dermatitis. Prior to this intervention, Northern European governments had already begun to regulate consumer nickel exposure. According to part 2 of the EU Nickel Directive...... by the EU Nickel Directive. Despite this, the EU Nickel Directive part 2 was expected to work as an operational limit that would sufficiently protect European consumers against nickel allergy and dermatitis. This review presents the accumulation of epidemiological studies that evaluated the possible effect...... and the Danish nickel regulation, consumer items intended to be in direct and prolonged contact with the skin were not allowed to release more than 0.5 µg nickel/cm2/week. It was considered unlikely that nickel allergy would disappear altogether as a proportion of individuals reacted below the level defined...

  13. Synthesis and growth mechanism of sponge-like nickel using a hydrothermal method

    Science.gov (United States)

    Shao, Bin; Yin, Xueguo; Hua, Weidong; Ma, Yilong; Sun, Jianchun; Li, Chunhong; Chen, Dengming; Guo, Donglin; Li, Kejian

    2018-05-01

    Sponge-like nickel composed of micro-chains with a diameter of 1-5 μm was selectively synthesized by the hydrothermal method, using sodium hydroxide (NaOH) as the alkaline reagent, aqueous hydrazine as reducing agent and citric acid as a coordination agent. The time-dependent samples prepared at different NaOH concentrations were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectrometer (FTIR). The results showed that the agglomerates of nickel citrate hydrazine complex nanoplates were first precipitated and then reduced to prickly nickel micro-chains at a lower NaOH concentration, which played a role in the further formation of sponge-like nickel. Also, the probable growth mechanism of the sponge-like nickel was proposed. The magnetic properties of sponge-like nickel were studied using a vibrating sample magnetometer. The sponge-like nickel exhibited a ferromagnetic behavior with a saturation magnetization value of 43.8 emu g-1 and a coercivity value of 120.7 Oe.

  14. Evaluation of cyclic flexural fatigue of M-wire nickel-titanium rotary instruments.

    Science.gov (United States)

    Al-Hadlaq, Solaiman M S; Aljarbou, Fahad A; AlThumairy, Riyadh I

    2010-02-01

    This study was conducted to investigate cyclic flexural fatigue resistance of GT series X rotary files made from the newly developed M-wire nickel-titanium alloy compared with GT and Profile nickel-titanium files made from a conventional nickel-titanium alloy. Fifteen files, size 30/0.04, of each type were used to evaluate the cyclic flexural fatigue resistance. A simple device was specifically constructed to measure the time each file type required to fail under cyclic flexural fatigue testing. The results of this experiment indicated that the GT series X files had superior cyclic flexural fatigue resistance than the other 2 file types made from a conventional nickel-titanium alloy (P = .004). On the other hand, the difference between the Profile and the GT files was not statistically significant. The findings of this study suggest that size 30/0.04 nickel-titanium rotary files made from the newly developed M-wire alloy have better cyclic flexural fatigue resistance than files of similar design and size made from the conventional nickel-titanium alloy. Copyright 2010 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  15. Toxicity of nickel in the marine calanoid copepod Acartia tonsa: Nickel chloride versus nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, C. [Istituto per la Protezione e Ricerca Ambientale ISPRA-STS Livorno, Piazzale dei marmi 12, 57123 Livorno (Italy); Academic Centre for Innovation and Development in the Food Industry (CAISIAL), Università degli Studi di Napoli Federico II, 80055 Portici (Italy); Vitiello, V. [Istituto per la Protezione e Ricerca Ambientale ISPRA-STS Livorno, Piazzale dei marmi 12, 57123 Livorno (Italy); Casals, E. [Institut Català de Nanotecnologia, Campus de la Universitat Autònoma de Barcelone, 08193 Bellaterra (Spain); Puntes, V.F. [Institut Català de Nanotecnologia, Campus de la Universitat Autònoma de Barcelone, 08193 Bellaterra (Spain); Institut Català de Recerca i Estudis Avançats (ICREA), Passeig Lluís Companys, 23, 08010 Barcelona (Spain); Iamunno, F. [Stazione Zoologica Anton Dohrn, Villa Comunale, Napoli (Italy); Pellegrini, D. [Istituto per la Protezione e Ricerca Ambientale ISPRA-STS Livorno, Piazzale dei marmi 12, 57123 Livorno (Italy); Changwen, W. [Zhejiang Ocean University, 1 Rd. South Haida, Lincheng New Area, Dinghai District Zhoushan City, 316022 (China); Benvenuto, G. [Stazione Zoologica Anton Dohrn, Villa Comunale, Napoli (Italy); Buttino, I., E-mail: isabella.buttino@isprambiente.it [Istituto per la Protezione e Ricerca Ambientale ISPRA-STS Livorno, Piazzale dei marmi 12, 57123 Livorno (Italy)

    2016-01-15

    Highlights: • Acartia tonsa copepod is more sensitive to NiCl{sub 2} than to nickel nanoparticles. • At the tested concentration egg production was not affected by both form of nickel. • Egg viability is the most sensitive end-point for both form of nickel. • Nickel dissolved in seawater increased with nanoparticle concentration. • Acartia tonsa adults were able to ingest nanoparticles. - Abstract: Nickel compounds are widely used in industries and have been massively introduced in the environment in different chemical forms. Here we report the effect of two different chemical forms of nickel, NiCl{sub 2} and nickel nanoparticles (NiNPs), on the reproduction of the marine calanoid copepod Acartia tonsa. The behavior of nickel nanoparticles was analyzed with different techniques and with two protocols. In the “sonicated experiment” (SON) NiNP solution was sonicated while in the “non-sonicated experiment” (NON-SON) the solution was vigorously shaken by hand. Final nominal concentrations of 5, 10 and 50 mg L{sup −1} and 1, 5 and 10 mg L{sup −1} NiNPs were used for the acute and semichronic tests, respectively. Nanoparticle size did not change over time except for the highest concentration of 50 mg L{sup −1} NiNPs, in which the diameter increased up to 843 nm after 48 h. The concentration of Ni dissolved in the water increased with NP concentration and was similar for SON and NON-SON solutions. Our results indicate that sonication does not modify toxicity for the copepod A. tonsa. Mean EC{sub 50} values were similar for NON-SON (20.2 mg L{sup −1}) and SON experiments (22.14 mg L{sup −1}) in the acute test. Similarly, no differences occurred between the two different protocols in the semichronic test, with an EC{sub 50} of 7.45 mg L{sup −1} and 6.97 mg L{sup −1} for NON-SON and SON experiments, respectively. Acute and semichronic tests, conducted exposing A. tonsa embryos to NiCl{sub 2} concentrations from 0.025 to 0.63 mg L{sup −1

  16. Line profile analysis of ODS steels Fe20Cr5AlTiY milled powders at different Y2O3 concentrations

    Science.gov (United States)

    Afandi, A.; Nisa, R.; Thosin, K. A. Z.

    2017-04-01

    Mechanical properties of material are largely dictated by constituent microstructure parameters such as dislocation density, lattice microstrain, crystallite size and its distribution. To develop ultra-fine grain alloys such as Oxide Dispersion Strengthened (ODS) alloys, mechanical alloying is crucial step to introduce crystal defects, and refining the crystallite size. In this research the ODS sample powders were mechanically alloyed with different Y2O3 concentration respectively of 0.5, 1, 3, and 5 wt%. MA process was conducted with High Energy Milling (HEM) with the ball to powder ratio of 15:1. The vial and the ball were made of alumina, and the milling condition is set 200 r.p.m constant. The ODS powders were investigated by X-Ray Diffractions (XRD), Bragg-Brentano setup of SmartLab Rigaku with 40 KV, and 30 mA, step size using 0.02°, with scanning speed of 4°min-1. Line Profile Analysis (LPA) of classical Williamson-Hall was carried out, with the aim to investigate the different crystallite size, and microstrain due to the selection of the full wide at half maximum (FWHM) and integral breadth.

  17. Experimental validation of concentration profiles in an HCCI engine, modelled by a multi-component kinetic mechanism: Outline for auto-ignition and emission control

    Energy Technology Data Exchange (ETDEWEB)

    Machrafi, Hatim, E-mail: hatim-machrafi@enscp.f [UPMC Universite Paris 06, Ecole Nationale Superieure de Chimie de Paris, 11, rue de Pierre et Marie Curie, 75005 Paris (France); Universite de Liege, Thermodynamique des Phenomenes Irreversibles, 17, Allee du Six-Aout, 4000 Liege (Belgium)

    2010-10-15

    In order to contribute to the auto-ignition and emission control for Homogeneous Charge Compression Ignition (HCCI), a kinetic multi-component mechanism, containing 62 reactions and 49 species for mixtures of n-heptane, iso-octane and toluene is validated in this work, comparing for the concentration profiles of the fuel, the total hydrocarbons, O{sub 2}, CO{sub 2}, CO, acetaldehyde and iso-butene. These species are sampled during the combustion and quantified. For these measurements an automotive exhaust analyser, a gas chromatograph, coupled to a mass spectrometer and a flame ionisation detector are used, depending on the species to be measured. The fuel, total hydrocarbons, O{sub 2}, CO{sub 2}, iso-butene and acetaldehyde showed a satisfactory quantitative agreement between the mechanism and the experiments. Both the experiments and the modelling results showed the same formation behaviour of the different species. An example is shown of how such a validated mechanism can provide for a set of information of the behaviour of the auto-ignition process and the emission control as a function of engine parameters.

  18. Experimental validation of concentration profiles in an HCCI engine, modelled by a multi-component kinetic mechanism: Outline for auto-ignition and emission control

    International Nuclear Information System (INIS)

    Machrafi, Hatim

    2010-01-01

    In order to contribute to the auto-ignition and emission control for Homogeneous Charge Compression Ignition (HCCI), a kinetic multi-component mechanism, containing 62 reactions and 49 species for mixtures of n-heptane, iso-octane and toluene is validated in this work, comparing for the concentration profiles of the fuel, the total hydrocarbons, O 2 , CO 2 , CO, acetaldehyde and iso-butene. These species are sampled during the combustion and quantified. For these measurements an automotive exhaust analyser, a gas chromatograph, coupled to a mass spectrometer and a flame ionisation detector are used, depending on the species to be measured. The fuel, total hydrocarbons, O 2 , CO 2 , iso-butene and acetaldehyde showed a satisfactory quantitative agreement between the mechanism and the experiments. Both the experiments and the modelling results showed the same formation behaviour of the different species. An example is shown of how such a validated mechanism can provide for a set of information of the behaviour of the auto-ignition process and the emission control as a function of engine parameters.

  19. Nickel may be released from laptop computers

    DEFF Research Database (Denmark)

    Jensen, Peter; Jellesen, Morten Stendahl; Møller, Per

    2012-01-01

    Consumer nickel sensitization and dermatitis is caused by prolonged or repeated skin exposure to items that release nickel, for example jewellery, belts, buttons, watches, and mobile phones (1–3). We recently described a patient in whom primary nickel contact sensitization and dermatitis develope...

  20. Electrodeposition of zinc--nickel alloys coatings

    Energy Technology Data Exchange (ETDEWEB)

    Dini, J W; Johnson, H R

    1977-10-01

    One possible substitute for cadmium in some applications is a zinc--nickel alloy deposit. Previous work by others showed that electrodeposited zinc--nickel coatings containing about 85 percent zinc and 15 percent nickel provided noticeably better corrosion resistance than pure zinc. Present work which supports this finding also shows that the corrosion resistance of the alloy deposit compares favorably with cadmium.

  1. Sintering of nickel steam reforming catalysts

    DEFF Research Database (Denmark)

    Sehested, Jens; Larsen, Niels Wessel; Falsig, Hanne

    2014-01-01

    . In this paper, particle migration and coalescence in nickel steam reforming catalysts is studied. Density functional theory calculations indicate that Ni-OH dominate nickel transport at nickel surfaces in the presence of steam and hydrogen as Ni-OH has the lowest combined energies of formation and diffusion...

  2. Phase transformation in nickel during tribotesting

    Energy Technology Data Exchange (ETDEWEB)

    Hershberger, J. [Energy Technology Division, Argonne National Laboratory, Building 212 Room D204, 9700 S Cass Avenue, Argonne, IL 60439 (United States)]. E-mail: jhersh@anl.gov; Ajayi, O.O. [Energy Technology Division, Argonne National Laboratory, Building 212 Room D204, 9700 S Cass Avenue, Argonne, IL 60439 (United States); Fenske, G.R. [Energy Technology Division, Argonne National Laboratory, Building 212 Room D204, 9700 S Cass Avenue, Argonne, IL 60439 (United States)

    2005-12-15

    Commercially pure nickel was subjected to a polyalphaolefin-lubricated reciprocating tribotest with increasing load. A friction transition was observed and X-ray diffraction was performed on low-friction and high-friction areas. Hexagonal nickel or nickel carbide was formed at high friction. Broadening of the face-centered cubic peaks did not show dislocation structures characteristic of scuffing.

  3. Phase transformation in nickel during tribotesting

    International Nuclear Information System (INIS)

    Hershberger, J.; Ajayi, O.O.; Fenske, G.R.

    2005-01-01

    Commercially pure nickel was subjected to a polyalphaolefin-lubricated reciprocating tribotest with increasing load. A friction transition was observed and X-ray diffraction was performed on low-friction and high-friction areas. Hexagonal nickel or nickel carbide was formed at high friction. Broadening of the face-centered cubic peaks did not show dislocation structures characteristic of scuffing

  4. Improved nickel plating of Inconel X-750

    Science.gov (United States)

    Farmer, M. E.; Feeney, J. E.; Kuster, C. A.

    1969-01-01

    Electroplating technique with acid pickling provides a method of applying nickel plating on Inconel X-750 tubing to serve as a wetting agent during brazing. Low-stress nickel-plating bath contains no organic wetting agents that cause the nickel to blister at high temperatures.

  5. Nickel-accumulating plant from Western Australia

    Energy Technology Data Exchange (ETDEWEB)

    Severne, B C; Brooks, R R

    1972-01-01

    A small shrub Hybanthus floribundus (Lindl.) F. Muell. Violaceae growing in Western Australia accumulates nickel and cobalt to a very high degree. Values of up to 23% nickel in leaf ash may represent the highest relative accumulation of a metal on record. The high accumulation of nickel poses interesting problems in plant physiology and plant biochemistry. 9 references, 2 figures, 1 table.

  6. Investigation of hydrogen evolution activity for the nickel, nickel-molybdenum nickel-graphite composite and nickel-reduced graphene oxide composite coatings

    International Nuclear Information System (INIS)

    Jinlong, Lv; Tongxiang, Liang; Chen, Wang

    2016-01-01

    Graphical abstract: - Highlights: • Improved HER efficiency of Ni-Mo coatings was attributed to ‘cauliflower’ like microstructure. • RGO in nickel-RGO composite coating promoted refined grain and facilitated HER. • Synergistic effect between nickel and RGO facilitated HER due to large specific surface of RGO. - Abstract: The nickel, nickel-molybdenum alloy, nickel-graphite and nickel-reduced graphene oxide composite coatings were obtained by the electrodeposition technique from a nickel sulfate bath. Nanocrystalline molybdenum, graphite and reduced graphene oxide in nickel coatings promoted hydrogen evolution reaction in 0.5 M H_2SO_4 solution at room temperature. However, the nickel-reduced graphene oxide composite coating exhibited the highest electrocatalytic activity for the hydrogen evolution reaction in 0.5 M H_2SO_4 solution at room temperature. A large number of gaps between ‘cauliflower’ like grains could decrease effective area for hydrogen evolution reaction in slight amorphous nickel-molybdenum alloy. The synergistic effect between nickel and reduced graphene oxide promoted hydrogen evolution, moreover, refined grain in nickel-reduced graphene oxide composite coating and large specific surface of reduced graphene oxide also facilitated hydrogen evolution reaction.

  7. Investigation of hydrogen evolution activity for the nickel, nickel-molybdenum nickel-graphite composite and nickel-reduced graphene oxide composite coatings

    Energy Technology Data Exchange (ETDEWEB)

    Jinlong, Lv, E-mail: ljlbuaa@126.com [Beijing Key Laboratory of Fine Ceramics, Institute of Nuclear and New Energy Technology, Tsinghua University, Zhongguancun Street, Haidian District, Beijing 100084 (China); State Key Lab of New Ceramic and Fine Processing, Tsinghua University, Beijing 100084 (China); Tongxiang, Liang; Chen, Wang [Beijing Key Laboratory of Fine Ceramics, Institute of Nuclear and New Energy Technology, Tsinghua University, Zhongguancun Street, Haidian District, Beijing 100084 (China); State Key Lab of New Ceramic and Fine Processing, Tsinghua University, Beijing 100084 (China)

    2016-03-15

    Graphical abstract: - Highlights: • Improved HER efficiency of Ni-Mo coatings was attributed to ‘cauliflower’ like microstructure. • RGO in nickel-RGO composite coating promoted refined grain and facilitated HER. • Synergistic effect between nickel and RGO facilitated HER due to large specific surface of RGO. - Abstract: The nickel, nickel-molybdenum alloy, nickel-graphite and nickel-reduced graphene oxide composite coatings were obtained by the electrodeposition technique from a nickel sulfate bath. Nanocrystalline molybdenum, graphite and reduced graphene oxide in nickel coatings promoted hydrogen evolution reaction in 0.5 M H{sub 2}SO{sub 4} solution at room temperature. However, the nickel-reduced graphene oxide composite coating exhibited the highest electrocatalytic activity for the hydrogen evolution reaction in 0.5 M H{sub 2}SO{sub 4} solution at room temperature. A large number of gaps between ‘cauliflower’ like grains could decrease effective area for hydrogen evolution reaction in slight amorphous nickel-molybdenum alloy. The synergistic effect between nickel and reduced graphene oxide promoted hydrogen evolution, moreover, refined grain in nickel-reduced graphene oxide composite coating and large specific surface of reduced graphene oxide also facilitated hydrogen evolution reaction.

  8. Void formation in irradiated binary nickel alloys

    International Nuclear Information System (INIS)

    Shaikh, M.A.; Ahmed, M.; Akhter, J.I.

    1994-01-01

    In this work a computer program has been used to compute void radius, void density and swelling parameter for nickel and binary nickel-carbon alloys irradiated with nickel ions of 100 keV. The aim is to compare the computed results with experimental results already reported

  9. Formation of nickel-tantalum compounds in tantalum fluoride halide melts

    International Nuclear Information System (INIS)

    Matychenko, Eh.S.; Zalkind, O.A.; Kuznetsov, B.Ya.; Orlov, V.M.; Sukhorzhevskaya, S.L.

    2001-01-01

    Interaction of nickel with NaCl-K 2 TaF 7 melt (14 mol.%) at 750 deg C was studied, the composition of intermetallic compounds formed in Ni-Ta system being analyzed, using the methods of chemical and X-ray phase analyses, IR spectroscopy. It was ascertained that composition of intermetallic compounds (Ni 3 Ta, Ni 2 Ta) depends on K 2 TaF 7 concentration in the melt, metallic tantalum additions, nickel substrate thickness and experiment duration. The mechanism of currentless deposition of tantalum on nickel was considered and the assumption was made that disproportionation reaction lies in the basis of the process [ru

  10. Study of Diffusion Bonding of 45 Steel through the Compacted Nickel Powder Layer

    Science.gov (United States)

    Zeer, G. M.; Zelenkova, E. G.; Temnykh, V. I.; Tokmin, A. M.; Shubin, A. A.; Koroleva, Yu. P.; Mikheev, A. A.

    2018-02-01

    The microstructure of the transition zone and powder spacer, the concentration distribution of chemical elements over the width of the diffusion-bonded joint, and microhardness of 45 steel-compacted Ni powder spacer-45 steel layered composites formed by diffusion bonding have been investigated. It has been shown that the relative spacer thickness χ compacting pressure of 500 MPa. The solid-state diffusion bonding is accompanied by sintering the nickel powder spacer and the formation of the transition zone between the spacer and steel. The transition zone consists of solid solution of nickel in the α-Fe phase and ordered solid solution of iron in nickel (FeNi3).

  11. Zinc-Nickel Codeposition in Sulfate Solution Combined Effect of Cadmium and Boric Acid

    Directory of Open Access Journals (Sweden)

    Y. Addi

    2011-01-01

    Full Text Available The combined effect of cadmium and boric acid on the electrodeposition of zinc-nickel from a sulfate has been investigated. The presence of cadmium ion decreases zinc in the deposit. In solution, cadmium inhibits the zinc ion deposition and suppresses it when deposition potential value is more negative than −1.2 V. Low concentration of CdSO4 reduces the anomalous nature of Zn-Ni deposit. Boric acid decreases current density and shifts potential discharge of nickel and hydrogen to more negative potential. The combination of boric acid and cadmium increases the percentage of nickel in the deposit. Boric acid and cadmium.

  12. Corrosion resistance of nickel alloys with chromium and silicon to the red fuming nitric acid

    International Nuclear Information System (INIS)

    Gurvich, L.Ya.; Zhirnov, A.D.

    1994-01-01

    Corrosion and electrochemical behaviour of binary Ni-Cr, Ni-Si nickel and ternary Ni-Cr-Si alloys in the red fuming nitric acid (RFNA) (8-% of HNO 3 +20% of N 2 O 4 ) is studied. It is shown that nickel alloying with chromium improves its corrosion resistance to the red fuming nitric acid. Nickel alloying with silicon in quantities of up to 5 % reduces, and up to 10%-increases abruptly the corrosion resistance with subsequent decrease of the latter after the further increase of concentration. Ni-15% of Cr alloy alloying with silicon increases monotonously the corrosion resistance. 10 refs., 7 figs., 3 tabs

  13. Magnetic effects of interstitial hydrogen in nickel

    Energy Technology Data Exchange (ETDEWEB)

    León, Andrea [Departamento de Física, Universidad Técnica Federico Santa María, Valparaíso (Chile); Velásquez, E.A. [Facultad de Física y Centro de Investigación en Nanotecnología y Materiales Avanzados CIEN-UC, Pontificia Universidad Católica de Chile, Santiago (Chile); Centro para el Desarrollo de la Nanociencia y la Nanotecnología CEDENNA, Santiago (Chile); Grupo de Investigación en Modelamiento y Simulación Computacional, Universidad de San Buenaventura Sec. Medellín, Medellín (Colombia); Mazo-Zuluaga, J. [Grupo de Instrumentación Científica y Microelectrónica, Grupo de Estado Sólido, IF-FCEN, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellín (Colombia); Mejía-López, J. [Facultad de Física y Centro de Investigación en Nanotecnología y Materiales Avanzados CIEN-UC, Pontificia Universidad Católica de Chile, Santiago (Chile); Centro para el Desarrollo de la Nanociencia y la Nanotecnología CEDENNA, Santiago (Chile); Florez, J.M. [Departamento de Física, Universidad Técnica Federico Santa María, Valparaíso (Chile); and others

    2017-01-01

    Hydrogen storage in materials is among the most relevant fields when thinking about energy conversion and storage. In this work we present a study that responds to a couple of questions concerning induced electronic changes that H produces in ferromagnetic nickel (Ni) host. We calculate and explain the change of magnetic properties of Ni with different concentrations of H. Density functional theory calculations (DFT) were performed for super-cells of fcc Ni with interstitial H in octahedral sites at different concentrations. In order to physically explain the effect of magnetization diminishing as the hydrogen concentration increases, we propose a simple Stoner type of model to describe the influence of the H impurity on the magnetic properties of Ni. The exchange splitting reduction, as shown in first principles calculations, is clearly explained within this physical model. Using a paramagnetic Ni fcc band with variable number of electrons and a Stoner model allow us to obtain the correct trend for the magnetic moment of the system as a function of the H concentration. - Highlights: • We calculate and explain the change of magnetic properties of Ni with different concentrations of H. • We propose a simple Stoner type of model to describe the influence of the H impurity on the magnetic properties of Ni. • The band exchange splitting reduction as the H concentration increases, is a consequence of the competition between the band energy term (kinetic energy) and the ferromagnetic energy term (Weiss field).

  14. Ecological Considerations on Nickel Dermatitis

    Science.gov (United States)

    Marcussen, Poul V.

    1960-01-01

    The incidence of nickel dermatoses has shifted from the plating industry to other occupations and particularly to non-occupational causes. A Danish survey of 621 cases shows that 4% are due to nickel plating, 9·5% to other occupations, and 86·5% were not due to occupation. A primary eruption not due to occupation had occurred in 14% of the occupational cases. The importance of preventive measures for the community more than for the adequately controlled industry is underlined. PMID:14420983

  15. Effect of Dietary Forage to Concentrate Ratios on Dynamic Profile Changes and Interactions of Ruminal Microbiota and Metabolites in Holstein Heifers

    Directory of Open Access Journals (Sweden)

    Jun Zhang

    2017-11-01

    Full Text Available A better understanding of global ruminal microbiota and metabolites under extensive feeding conditions is a prerequisite for optimizing rumen function and improving ruminant feed efficiency. Furthermore, the gap between the information on the ruminal microbiota and metabolites needs to be bridged. The aim of this study was to investigate the effects of a wide range of forage to concentrate ratios (F:C on changes and interactions of ruminal microbiota and metabolites. Four diets with different F:C (80:20, 60:40, 40:60, and 20:80 were limit-fed to 24 Holstein heifers, and Illumina MiSeq sequencing and gas chromatography time-of-flight/mass spectrometry were used to investigate the profile changes of the ruminal microbes and metabolites, and the interaction between them. The predominant bacterial phyla in the rumen were Bacteroidetes (57.2 ± 2.6% and Firmicutes (26.8 ± 1.6%, and the predominant anaerobic fungi were Neocallimastigomycota (64.3 ± 3.8% and Ascomycota (22.6 ± 2.4%. In total, 44, 9, 25, and 2 genera, respectively, were identified as the core rumen bacteria, ciliate protozoa, anaerobic fungi, and archaea communities across all samples. An increased concentrate level linearly decreased the relative abundance of cellulolytic bacteria and ciliates, namely Fibrobacter, Succinimonas, Polyplastron, and Ostracodinium (q < 0.05, and linearly increased the relative abundance of Entodinium (q = 0.04, which is a non-fibrous carbohydrate degrader. Dietary F:C had no effect on the communities of anaerobic fungi and archaea. Rumen metabolomics analysis revealed that ruminal amino acids, lipids, organic acids, and carbohydrates were altered significantly by altering the dietary F:C. With increasing dietary concentrate levels, the proportions of propionate and butyrate linearly increased in the rumen (P ≤ 0.01. Correlation analysis revealed that there was some utilization relationship or productive association between candidate metabolites and

  16. Calculation of concentration profiles and their experimental verification with a pulsed sieve-plate column and the reactive material system of uranyl nitrate, nitric acid/tributyl phosphate, kerosine

    International Nuclear Information System (INIS)

    Ihle, E.

    1985-01-01

    The present study is concerned with the calculation of stationary and non-stationary concentration profiles as well as with the starting and disturbance behaviour of a pulsed sieve-plate extraction column. It investigates into the material system HNO 3 /uranyl nitrate in water with 30 per cent by volume of tributyl phosphate in kerosine. During the measurements of the concentration profiles for HNO 3 transition, which were effected in the direction of extraction and reextraction, it was shown that the concentration profiles measured in the mixer-settler range, in spite of a sixfold enlargement of the specific heat transfer area, do not differ essentially from those measured in the dispersion range. During the measurements of concentration profiles for HNO 3 /uranium transition, which were effected in the direction of coextraction and co-reextraction only for mixer-settler range, it was discovered that with increasing phase ratios, there is a depletion of the uranium concentration in the aqueous phase. If the phase ratio is further raised, it is the nitric acid, and not the uranium, that is depleted. (orig./PW) [de

  17. Reactivity to patch tests with nickel sulfate and fragrance mix in infants

    DEFF Research Database (Denmark)

    Jøhnke, H; Norberg, L A; Vach, W

    2004-01-01

    sulfate in 3 concentrations, 200, 66 and 22 microg/cm(2), and fragrance mix 430 microg/cm(2) were used. A likely case of nickel sensitivity was defined as a reproducible positive reaction with at least homogeneous erythema and palpable infiltration occurring at least 2x and present at both the 12 and 18......The pattern of patch test reactivity to nickel sulfate and fragrance mix was studied with respect to patch test performance, reproducibility and clinical relevance in a population of unselected infants followed prospectively from birth to 18 months of age. TRUE Testtrade mark patches with nickel...... sensitivity was found in only 1 child. No reproducible positive reaction to fragrance mix was found. The high proportion of transient patch test reactivity to nickel sulfate 200 microg/cm(2) indicates that this standard concentration used for adults cannot be applied to infants. The interpretation of a single...

  18. [Nickel exposure to A549 cell damage and L-ascorbic acid interference effect].

    Science.gov (United States)

    Fu, Yao; Wang, Yue; Dan, Han; Zhang, Lin; Ma, Wenhan; Pan, Yulin; Wu, Yonghui

    2015-05-01

    Studying different concentrations of nickel smelting smoke subjects of human lung adenocarcinoma cells (A549) carcinogenic effects, discusses the influence of L-ascorbic acid protection. The A549 cells were divided into experimental and L-ascorbic acid in the intervention group. Plus exposure group concentration of nickel refining dusts were formulated 0.00, 6.25, 12.50, 25.00, 50.00, 100.00 µg/ml suspension, the intervention group on the basis of the added exposure group containing L-ascorbic acid (100 mmol/L), contact 24 h. Detection of cell viability by MTT assay. When the test substance concentration select 0.00, 25.00, 50.00, 100.00 µg/ml experiment for internal Flou-3 fluorescent probe to detect cell Ca²⁺ concentration, within DCFH-DA detect intracellular reactive oxygen (ROS) content, real-time quantitative PCR (real time, in the RT-PCR) was used to detect cell HIF-1α gene expression. With the increase of concentration, subjects increased cell growth inhibition rate, intracellular Ca²⁺ concentration increases, ROS content increased, HIF-1α gene expression increased, differences were statistically significant (P nickel exposure damage to cells. With subjects following exposure to nickel concentration increased, its effect on A549 cell damage increases, L-ascorbic acid cell damage caused by nickel has certain protective effect.

  19. Carbon formation on nickel and nickel-copper alloy catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Alstrup, I.; Soerensen, O.; Rostrup-Nielsen, J.R. [Haldor Topsoe Research Labs., Lyngby (Denmark); Tavares, M.T.; Bernardo, C.A.

    1998-05-01

    Equilibrium, kinetic and morphological studies of carbon formation in CH{sub 4} + H{sub 2}, CO, and CO + H{sub 2} gases on silica supported nickel and nickel-copper catalysts are reviewed. The equilibrium deviates in all cases from graphite equilibrium and more so in CO + CO{sub 2} than in CH{sub 4} + H{sub 2}. A kinetic model based on information from surface science results with chemisorption of CH{sub 4} and possibly also the first dehydrogenation step as rate controlling describes carbon formation on nickel catalyst in CH{sub 4} + H{sub 2} well. The kinetics of carbon formation in CO and CO + H{sub 2} gases are in agreement with CO disproportionation as rate determining step. The presence of hydrogen influences strongly the chemisorption of CO. Carbon filaments are formed when hydrogen is present in the gas while encapsulating carbon dominates in pure CO. Small amounts of Cu alloying promotes while larger amounts (Cu : Ni {>=} 0.1) inhibits carbon formation and changes the morphology of the filaments (``octopus`` carbon formation). Adsorption induced nickel segregation changes the kinetics of the alloy catalysts at high carbon activities. Modifications suggested in some very recent papers on the basis of new results are also briefly discussed. (orig.) 31 refs.

  20. Toxicity of nickel in the marine calanoid copepod Acartia tonsa: Nickel chloride versus nanoparticles.

    Science.gov (United States)

    Zhou, C; Vitiello, V; Casals, E; Puntes, V F; Iamunno, F; Pellegrini, D; Changwen, W; Benvenuto, G; Buttino, I

    2016-01-01

    Nickel compounds are widely used in industries and have been massively introduced in the environment in different chemical forms. Here we report the effect of two different chemical forms of nickel, NiCl2 and nickel nanoparticles (NiNPs), on the reproduction of the marine calanoid copepod Acartia tonsa. The behavior of nickel nanoparticles was analyzed with different techniques and with two protocols. In the "sonicated experiment" (SON) NiNP solution was sonicated while in the "non-sonicated experiment" (NON-SON) the solution was vigorously shaken by hand. Final nominal concentrations of 5, 10 and 50mgL(-1) and 1, 5 and 10mgL(-1) NiNPs were used for the acute and semichronic tests, respectively. Nanoparticle size did not change over time except for the highest concentration of 50mgL(-1) NiNPs, in which the diameter increased up to 843nm after 48h. The concentration of Ni dissolved in the water increased with NP concentration and was similar for SON and NON-SON solutions. Our results indicate that sonication does not modify toxicity for the copepod A. tonsa. Mean EC50 values were similar for NON-SON (20.2mgL(-1)) and SON experiments (22.14mgL(-1)) in the acute test. Similarly, no differences occurred between the two different protocols in the semichronic test, with an EC50 of 7.45mgL(-1) and 6.97mgL(-1) for NON-SON and SON experiments, respectively. Acute and semichronic tests, conducted exposing A. tonsa embryos to NiCl2 concentrations from 0.025 to 0.63mgL(-1), showed EC50 of 0.164 and 0.039mgL(-1), respectively. Overall, A. tonsa is more sensitive to NiCl2 than NiNPs with EC50 being one order of magnitude higher for NiNPs. Finally, we exposed adult copepods for 4 days to NiCl2 and NiNPs (chronic exposure) to study the effect on fecundity in terms of daily egg production and naupliar viability. Egg production is not affected by either form of nickel, whereas egg viability is significantly reduced by 0.025mgL(-1) NiCl2 and by 8.5mgL(-1) NiNPs. At NiNP concentration

  1. Electrokinetic remediation of lead and nickel in land farming soil of petroleum refinery; Remediacao eletrocinetica de chumbo e niquel em solos de landfarming de uma refinaria de petroleo

    Energy Technology Data Exchange (ETDEWEB)

    Guaracho, Viviane V.; Ponte, Maria Jose J.S.; Adamoski, Luiz Felipe [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil)

    2004-07-01

    In many areas in the world, the ground has been seriously contaminated, had to practical of inadequate disposal and pollutant industrial activities. This polluted soil becomes a threat to the environment for presenting toxical substances, as the heavy metals. The alternative to solve this threat is a technique of electrokinetic remediation, which has been considered promising because it presents an excellent potential of recovery of places contaminated by heavy metals. This technique consists on the application of a direct current of low intensity through the ground between two or more electrodes. This way, the objective of this work is to evaluate the performance of the electrokinetic remediation for removal of Lead and Nickel, from the ground of land farming from petroleum refineries. The ground will be simulated using contaminated sand with nickel and lead nitrate with concentrations previously established. For a reduction in the experimental costs, one technique of statistical planning will be used. Parameters will be modified as: concentration of ions, applied potential and time. Through the concentration profile it is intended to calculate the coefficient of mass transport in order to get a correlation between the concentration and the flow of the species. Aiming at a economical evaluation of the reactor, the current and the energy consumption efficiencies will be evaluated. (author)

  2. Solubility of nickel ferrite (NiFe2O4) from 100 to 200 deg. C

    International Nuclear Information System (INIS)

    Bellefleur, Alexandre; Bachet, Martin; Benezeth, Pascale; Schott, Jacques

    2012-09-01

    The solubility of nickel ferrite was measured in a Hydrogen-Electrode Concentration Cell (HECC) at temperatures of 100 deg. C, 150 deg. C and 200 deg. C and pH between 4 and 5.25. The experimental solution was composed of HCl and NaCl (0.1 mol.L -1 ). Based on other studies ([1,2]), pure nickel ferrite was experimentally synthesized by calcination of a mixture of hematite Fe 2 O 3 and bunsenite NiO in molten salts at 1000 deg. C for 15 hours in air. The so obtained powder was fully characterized. The Hydrogen-Electrode Concentration cell has been described in [3]. It allowed us to run solubility experiments up to 250 deg. C with an in-situ pH measurement. To avoid reduction of the solid phase to metallic nickel, a hydrogen/argon mixture was used instead of pure hydrogen. Consequently, the equilibration time for the electrodes was longer than with pure hydrogen. Eight samples were taken on a 70 days period. After the experiments, the powder showed no significant XRD evidence of Ni (II) reduction. Nickel concentration was measured by atomic absorption spectroscopy and iron concentration was measured by UV spectroscopy. The protocol has been designed to be able to measure both dissolved Fe (II) and total iron. The nickel solubility of nickel ferrite was slightly lower than the solubility of nickel oxide in close experimental conditions [3]. Dissolved iron was mainly ferrous and the solution was under-saturated relative to both hematite and magnetite. The nickel/iron ratio indicated a non-stoichiometric dissolution. The solubility measurements were compared with equilibrium calculations using the MULTEQ database. [1] Hayashi et al (1980) J. Materials Sci. 15, 1491-1497. [2] Ziemniak et al (2007) J. Physics and Chem. of Solids. 68,10-21. [3] EPRI Report 1003155 (2002). (authors)

  3. 2-Mercaptobenzimidazole, 2-Mercaptobenzothiazole, and Thioglycolic Acid in an Electroless Nickel-Plating Bath

    OpenAIRE

    Ahmet Ozan Gezerman; Burcu Didem Çorbacıoğlu

    2015-01-01

    The use of three different materials, 2-mercaptobenzimidazole, 2-mercaptobenzothiazole, and thioglycolic acid, was investigated to improve the performance of electroless nickel-plating baths. By changing the concentrations of these materials, sample plates were coated. Optical microscope images were obtained by selecting representative coated plates. From the results of the investigations, the effects of these materials on electroless nickel plating were observed, and the most appropriate amo...

  4. Nickel exposure from keys: a Brazilian issue.

    Science.gov (United States)

    Suzuki, Nathalie Mie; Duarte, Ida Alzira Gomes; Hafner, Mariana de Figueiredo Silva; Lazzarini, Rosana

    2017-01-01

    Keys are a significant source of exposure to metal allergens and can be a relevant problem for nickel-allergic individuals. This study aimed to perform nickel and cobalt spot testing among the 5 most common Brazilian brands of keys. Among the tested keys, 100% showed positive result to nickel spot test, 83,3% presented strong positive reaction. 50% exhibited cobalt release as well. Nickel release from keys is very common in our country and may cause a negative impact on sensitized individual's quality of life. Study's results highlight the importance of establishing directives to regulate nickel release in Brazil.

  5. Heat treatment of nickel alloys

    International Nuclear Information System (INIS)

    Smith, D.F. Jr.; Clatworthy, E.F.

    1975-01-01

    A heat treating process is described that can be used to produce desired combinations of strength, ductility, and fabricability characteristics in heat resistant age-hardenable alloys having precipitation-hardening amounts of niobium, titanium, and/or tantalum in a nickel-containing matrix. (U.S.)

  6. Electrolytic nickel deposits upon uranium

    International Nuclear Information System (INIS)

    Baudin, G.; Chauvin, G.; Coriou, H.; Hure, J.

    1958-01-01

    The authors present a new possibility to protect uranium by very adherent nickel deposits got by aqueous medium electrolysis. Surface treatment of uranium is based upon the chemical etching method from Lietazke. After thermal treatments at 600, 700 and 800 deg. C, under vacuum, a good intermetallic U-Ni diffusion is observed for each case. (author) [fr

  7. Iron-nickel-chromium alloys

    International Nuclear Information System (INIS)

    Karenko, M.K.

    1981-01-01

    A specification is given for iron-nickel-chromium age-hardenable alloys suitable for use in fast breeder reactor ducts and cladding, which utilize the gamma-double prime strengthening phase and are characterized in having a delta or eta phase distributed at or near grain boundaries. A range of compositions is given. (author)

  8. ELECTRODEPOSITION OF NICKEL ON URANIUM

    Science.gov (United States)

    Gray, A.G.

    1958-08-26

    A method is described for preparing uranium objects prior to nickel electroplating. The process consiats in treating the surface of the uranium with molten ferric chloride hexahydrate, at a slightiy elevated temperature. This treatment etches the metal surface providing a structure suitable for the application of adherent electrodeposits and at the same time plates the surface with a thin protective film of iron.

  9. Electrolyte management considerations in modern nickel/hydrogen and nickel/cadmium cells and battery designs

    Energy Technology Data Exchange (ETDEWEB)

    Thaller, L.H. [The Aerospace Corporation, El Segundo, CA (United States); Zimmermann, A.H. [The Aerospace Corporation, El Segundo, CA (United States)

    1996-11-01

    While attention has been paid to understanding and modeling abnormal nickel/hydrogen cell behaviors, not enough attention has been paid to the potassium ion content in these cells, and more recently, in batteries. This paper will review three general areas where the potassium ion content can impact the performance and life of nickel/hydrogen and nickel/cadmium cells. Sample calculations of the concentration or volume changes that can take place within operating cells will be presented. With the aid of an accurate model of an operating cell or battery, the impact of changes of potassium ion content within a potential cell design can be estimated. All three of these areas are directly related to the volume tolerance and pore size engineering aspects of the components used in the cell or battery design. the three areas follow. (i) The gamma phase uptake of potassium ion can result in a lowering of the electrolyte concentration. This leads to a higher electrolyte resistance as well as electrolyte diffusional limitations on the discharge rate. This phenomenon also impacts the response of the cell to a reconditioning cycle. (ii) The transport of water vapor from a warmer to a cooler portion of the cell or battery under the driving force of a vapor pressure gradient has already impacted cells when water vapor condenses on a colder cell wall. This paper will explore the convective and diffusive movement of gases saturated with water vapor from a warmer plate pack to a cooler one, both with and without liquid communication. (iii) The impact of low level shunt currents in multicell configurations results in the net movement of potassium hydroxide from one part of the battery to another. This movement impacts the electrolyte volume/vapor pressure relationship within the cell or battery. (orig.)

  10. Nickel exposure induces oxidative damage to mitochondrial DNA in Neuro2a cells: the neuroprotective roles of melatonin.

    Science.gov (United States)

    Xu, Shang-Cheng; He, Min-Di; Lu, Yong-Hui; Li, Li; Zhong, Min; Zhang, Yan-Wen; Wang, Yuan; Yu, Zheng-Ping; Zhou, Zhou

    2011-11-01

    Recent studies suggest that oxidative stress and mitochondrial dysfunction play important roles in the neurotoxicity of nickel. Because mitochondrial DNA (mtDNA) is highly vulnerable to oxidative stress and melatonin can efficiently protect mtDNA against oxidative damage in various pathological conditions, the aims of this study were to determine whether mtDNA oxidative damage was involved in the neurotoxicity of nickel and to assay the neuroprotective effects of melatonin in mtDNA. In this study, we exposed mouse neuroblastoma cell lines (Neuro2a) to different concentrations of nickel chloride (NiCl(2), 0.125, 0.25, and 0.5 mm) for 24 hr. We found that nickel significantly increased reactive oxygen species (ROS) production and mitochondrial superoxide levels. In addition, nickel exposure increased mitochondrial 8-hydroxyguanine (8-OHdG) content and reduced mtDNA content and mtDNA transcript levels. Consistent with this finding, nickel was found to destroy mtDNA nucleoid structure and decrease protein levels of Tfam, a key protein component for nucleoid organization. However, all the oxidative damage to mtDNA induced by nickel was efficiently attenuated by melatonin pretreatment. Our results suggest that oxidative damage to mtDNA may account for the neurotoxicity of nickel. Melatonin has great pharmacological potential in protecting mtDNA against the adverse effects of nickel in the nervous system. © 2011 John Wiley & Sons A/S.

  11. Corrosion Characterization in Nickel Plated 110 ksi Low Alloy Steel and Incoloy 925: An Experimental Case Study

    Science.gov (United States)

    Thomas, Kiran; Vincent, S.; Barbadikar, Dipika; Kumar, Shresh; Anwar, Rebin; Fernandes, Nevil

    2018-04-01

    Incoloy 925 is an age hardenable Nickel-Iron-Chromium alloy with the addition of Molybdenum, Copper, Titanium and Aluminium used in many applications in oil and gas industry. Nickel alloys are preferred mostly in corrosive environments where there is high concentration of H2S, CO2, chlorides and free Sulphur as sufficient nickel content provides protection against chloride-ion stress-corrosion cracking. But unfortunately, Nickel alloys are very expensive. Plating an alloy steel part with nickel would cost much lesser than a part make of nickel alloy for large quantities. A brief study will be carried out to compare the performance of nickel plated alloy steel with that of an Incoloy 925 part by conducting corrosion tests. Tests will be carried out using different coating thicknesses of Nickel on low alloy steel in 0.1 M NaCl solution and results will be verified. From the test results we can confirm that Nickel plated low alloy steel is found to exhibit fairly good corrosion in comparison with Incoloy 925 and thus can be an excellent candidate to replace Incoloy materials.

  12. Lettuce (Lactuca sativa L.) leaf-proteome profiles after exposure to cylindrospermopsin and a microcystin-LR/cylindrospermopsin mixture: a concentration-dependent response.

    Science.gov (United States)

    Freitas, Marisa; Campos, Alexandre; Azevedo, Joana; Barreiro, Aldo; Planchon, Sébastien; Renaut, Jenny; Vasconcelos, Vitor

    2015-02-01

    The intensification of agricultural productivity is an important challenge worldwide. However, environmental stressors can provide challenges to this intensification. The progressive occurrence of the cyanotoxins cylindrospermopsin (CYN) and microcystin-LR (MC-LR) as a potential consequence of eutrophication and climate change is of increasing concern in the agricultural sector because it has been reported that these cyanotoxins exert harmful effects in crop plants. A proteomic-based approach has been shown to be a suitable tool for the detection and identification of the primary responses of organisms exposed to cyanotoxins. The aim of this study was to compare the leaf-proteome profiles of lettuce plants exposed to environmentally relevant concentrations of CYN and a MC-LR/CYN mixture. Lettuce plants were exposed to 1, 10, and 100 μg/l CYN and a MC-LR/CYN mixture for five days. The proteins of lettuce leaves were separated by two-dimensional electrophoresis (2-DE), and those that were differentially abundant were then identified by matrix-assisted laser desorption/ionization time of flight-mass spectrometry (MALDI-TOF/TOF MS). The biological functions of the proteins that were most represented in both experiments were photosynthesis and carbon metabolism and stress/defense response. Proteins involved in protein synthesis and signal transduction were also highly observed in the MC-LR/CYN experiment. Although distinct protein abundance patterns were observed in both experiments, the effects appear to be concentration-dependent, and the effects of the mixture were clearly stronger than those of CYN alone. The obtained results highlight the putative tolerance of lettuce to CYN at concentrations up to 100 μg/l. Furthermore, the combination of CYN with MC-LR at low concentrations (1 μg/l) stimulated a significant increase in the fresh weight (fr. wt) of lettuce leaves and at the proteomic level resulted in the increase in abundance of a high number of proteins. In

  13. Antimicrobial susceptibility profile and research of mec A and erm genes in coagulase-negative staphylococci isolated from platelet concentrates bags

    Directory of Open Access Journals (Sweden)

    Rosiéli Martini

    2017-04-01

    Full Text Available Abstract In recent years, several studies have described the clinical impact of bacterial infection associated with transfusion of platelet concentrates (PCs. Among the blood components, PCs are responsible for the highest rates of bacterial contamination as well as septic transfusion reactions. We assessed antimicrobial susceptibility profile, resistance to methicillin (MRCoNS, and resistance to macrolides, lincosamides and streptogramins of group B (MLSB of 16 coagulase-negative staphylococci (CoNS isolates from an investigation in 691 PCs bags. We then compared conventional and automated phenotypic methods, disc diffusion test (DD and VITEK(r 2, respectively as well as phenotypic and genotypic methods (Polymerase Chain Reaction - PCR. All CoNS were susceptible to vancomycin. The disc diffusion test characterized 18.75% as MRCoNS and 37.5% with inducible resistance to MLSB (iMLSB, and with VITEK(r 2, 6.3% and 31.25%, respectively. The mecA gene was detected in 18.75% and the erm gene in 31.25% of the isolates. In this study, we found equal percentage values between presence of the mecA gene by PCR and resistance to methicillin using cefoxitin by DD test, evidence of the erm gene by PCR, and iMLSB resistance by automation (VITEK(r 2. Moreover, we identified three strains with beta-lactamase overproduction, and the occurrence of a bigger mistake was verified when automation was compared with DD test. And we observed that D-test was the most reliable for the detection of iMLSB resistance in Staphylococcus sp.

  14. Sodium hypophosphite radiographic process using an ammoniacal nickel developer

    International Nuclear Information System (INIS)

    Struckmeyer, R.K.

    1976-01-01

    Experiments were performed to determine the effect of four factors on the yield of nickel from samples of sodium hypophosphite which were exposed to 60 Co gamma radiation and then treated to an ammoniacal nickel chloride developer. The factors included sample mass, radiation exposure, development time, and concentration of NiCl 2 in the developer. Optimum normalized yields were obtained with a sample mass of 0.5 g, an exposure of 1.2 x 10 6 rad, and a development time of 8 h. The yield of Ni was observed to increase linearly with developer concentration. Attempts to prepare radiographic emulsions containing sodium hypophosphite met with limited success as only ethyl cellulose proved successful, and even these exhibited reduced sharpness of the image after only one or two days of storage

  15. Removal of Nickel from Aqueous Solution by Hard-Shell Pistachios

    Directory of Open Access Journals (Sweden)

    Shayan Shamohammadi

    2013-08-01

    Full Text Available Nickel is one of the heavy metals which commonly can be found in industrial wastewater. Many studies have been done on agricultural waste for the removal of nickel from aqueous solutions. The purpose of this study is to identify hard-shell pistachios as a local attraction for removal of nickel from aqueous solution. Nickel adsorption isotherm models are studied using shell pistachios. Pistachio shell was chosen which its particle size is between 800-600 microns. The stock solution of nickel ions was prepared mixing nickel nitrate with distilled water. The results showed that the maximum absorption efficiency occurs (73.3% at pH=8. Also, it was shown that with increasing adsorbent dose, equilibrium time decreased within constant concentration. Examination of uptake isotherm models showed that models of Freundlich, BET, Radke-Praunitz, Redlich-Peterson and Sips describe data in 97% level of confidence well,  however Freundlich and Sips isotherm models has the lowest error factor 0.10597 and 0/10598 respectively and the highest correlation coefficient (0.9785. Comparison of adsorbent capacity within removal of nickel from aqueous solution shows that Pistachio shell with special absorbent surface of 1.7 m2/g and uptake capacity of 0.3984 mg/g is proper than adsorbents of Kaolinite, Bagasse, sludge-ash.

  16. Nickel sulfate induces numerous defects in Caenorhabditis elegans that can also be transferred to progeny

    International Nuclear Information System (INIS)

    Wang Dayong; Wang Yang

    2008-01-01

    Whether the multiple biological toxicities from nickel exposure could be transferred to progeny has not been clarified. In this report, we explored the Caenorhabditis elegans to analyze the multiple toxicities of nickel and their possibly transferable properties. The nickel toxicity caused multiple biological defects in a concentration-dependent manner. Moreover, most of these toxicities could be transferred and could be only partially rescued in progeny. Some specific phenotypes in progeny were also found to exhibit no obvious rescue phenotypes or to show even more severe defects than their parents. The defects caused by nickel exposure could be classified into four groups according to their transferring properties. That is, the defects caused by nickel exposure could be largely, or partially, or unable to be rescued, or became even more severe in progeny animals. Therefore, most of the nickel exposure-caused defects can be transferred from parents to their progeny to different degrees in C. elegans. - Nickel exposure can cause multi-biological toxicities and these defects can be transferred from parents to their progeny in C. elegans

  17. The Influence of Salt Anions on Heavy Metal Ion Adsorption on the Example of Nickel

    Science.gov (United States)

    Mende, Mandy; Schwarz, Dana; Steinbach, Christine; Schwarz, Simona

    2018-01-01

    The biodegradable polysaccharide chitosan possesses protonated and natural amino groups at medium pH values and has therefore been used as an adsorbing material for nickel salts in water treatment. Nickel is a problematic heavy metal ion which can cause various diseases and disorders in living organisms. Here, we show the influence of oxyanions (e.g., nitrate and sulfate) to the adsorption of nickel ions. Hence, simultaneously we are addressing the increasing global problem of nitrate and sulfate ion pollution in groundwater and surface water. A series of adsorption experiments was carried out in order to determine (i) the adsorption equilibrium, (ii) the adsorption capacity in dependence on the initial nickel ion concentration, and (iii) the influence of the anion presented in solution for the adsorption capacity. Surface morphology of chitosan flakes before and after the adsorption process has been studied with SEM-EDX analysis. The chitosan flakes exhibited promising adsorption capacities of 81.9 mg·g−1 and 21.2 mg·g−1 for nickel (sulfate) and nickel (nitrate), respectively. The calculated values of Gibbs free energy change ΔG0 confirm the higher adsorption of nickel ions in presence of sulfate ions. Hence, higher anion valence leads to a higher adsorption capacity. PMID:29510485

  18. Nickel sulfate induces numerous defects in Caenorhabditis elegans that can also be transferred to progeny

    Energy Technology Data Exchange (ETDEWEB)

    Wang Dayong [Department of Genetics and Developmental Biology, Southeast University, Nanjing 210009 (China); Key Laboratory of Developmental Genes and Human Disease, Ministry of Education (China)], E-mail: dayongw@seu.edu.cn; Wang Yang [Department of Genetics and Developmental Biology, Southeast University, Nanjing 210009 (China); Key Laboratory of Developmental Genes and Human Disease, Ministry of Education (China)

    2008-02-15

    Whether the multiple biological toxicities from nickel exposure could be transferred to progeny has not been clarified. In this report, we explored the Caenorhabditis elegans to analyze the multiple toxicities of nickel and their possibly transferable properties. The nickel toxicity caused multiple biological defects in a concentration-dependent manner. Moreover, most of these toxicities could be transferred and could be only partially rescued in progeny. Some specific phenotypes in progeny were also found to exhibit no obvious rescue phenotypes or to show even more severe defects than their parents. The defects caused by nickel exposure could be classified into four groups according to their transferring properties. That is, the defects caused by nickel exposure could be largely, or partially, or unable to be rescued, or became even more severe in progeny animals. Therefore, most of the nickel exposure-caused defects can be transferred from parents to their progeny to different degrees in C. elegans. - Nickel exposure can cause multi-biological toxicities and these defects can be transferred from parents to their progeny in C. elegans.

  19. Separation and Preconcentration of Trace Amounts of Nickel from Aqueous Samples

    Directory of Open Access Journals (Sweden)

    Reyhaneh Rahnama

    2018-05-01

    Full Text Available In this paper, a new method for preconcentration and measurement of trace amounts of nickel in aqueous samples by magnetic solid phase extraction (MSPE via magnetic carbon nanotubes (Mag-CNTs was developed. In order to increase selectivity, α-Furildioxime was used as chelating agent. In order to do extraction, optimum amount of ligand was added to the nickel sample and pH was set on 9, then 7 ml. of adsorbent was added and stirred for 15 minutes. After that, aqueous phase and adsorbent were separated by a strong magnet. Finally, the absorption was measured via flame atomic absorption spectrometry by analyte elution from the absorbent with an appropriate solution. Parameters affecting the extraction and preconcentration of nickel were investigated and optimized. Under optimum conditions, the calibration curve was linear in concentration range from 2.5 to 375 µg L-1 and the detection limit was 0.8 µg L-1 of nickel. The method was applied for determination of nickel in aqueous samples. The relative efficiency values of nickel measurement in aqueous samples were from 98.7% to 102.1%.  Results indicated that Mag-CNTs can be used as an effective and inexpensive absorbent for preconcentration and extraction of nickel from actual samples.

  20. Nickel-induced crystallization of amorphous silicon

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, J A; Arce, R D; Buitrago, R H [INTEC (CONICET-UNL), Gueemes 3450, S3000GLN Santa Fe (Argentina); Budini, N; Rinaldi, P, E-mail: jschmidt@intec.unl.edu.a [FIQ - UNL, Santiago del Estero 2829, S3000AOM Santa Fe (Argentina)

    2009-05-01

    The nickel-induced crystallization of hydrogenated amorphous silicon (a-Si:H) is used to obtain large grained polycrystalline silicon thin films on glass substrates. a-Si:H is deposited by plasma enhanced chemical vapour deposition at 200 deg. C, preparing intrinsic and slightly p-doped samples. Each sample was divided in several pieces, over which increasing Ni concentrations were sputtered. Two crystallization methods are compared, conventional furnace annealing (CFA) and rapid thermal annealing (RTA). The crystallization was followed by optical microscopy and scanning electron microscopy observations, X-ray diffraction, and reflectance measurements in the UV region. The large grain sizes obtained - larger than 100{mu}m for the samples crystallized by CFA - are very encouraging for the preparation of low-cost thin film polycrystalline silicon solar cells.

  1. Effect of Nickel on the growth of Spirulina maxima (Arthrospira)

    Energy Technology Data Exchange (ETDEWEB)

    Dominguez-Bocanegra, A. R.; Torres-Munoz, J. A.; Neria-Gonzalez, M. I.; Rios-Leal, E.; Aguilar-Lopez, R.

    2009-07-01

    Nickel is not produced in Mexico, but is a component widely used in the paper industry, fertilizers, iron foundry, and jewels fabrication among others. therefore it is founded in residual waters coming form domestic and industrial. It is known that such a heavy metal is essential to the life of some microorganisms including microalgae, however at relatively high concentrations it turns to be toxic inside some physiological processes (Jin et al., 1996). (Author)

  2. Nickel-based anodic electrocatalysts for fuel cells and water splitting

    Science.gov (United States)

    Chen, Dayi

    -based catalysts, methanol oxidation suffers from high overpotential and catalyst poisoning by high concentration of substrates, so current nickel-based catalysts are more suitable to be used as oxygen evolution catalysts. A photoanode design that applies nickel oxides to a semiconductor that is incorporated with surface-plasmonic metal electrodes to do solar water oxidation with visible light is proposed.

  3. Electroplated tin-nickel coatings as a replacement for nickel to eliminate nickel dermatitis

    DEFF Research Database (Denmark)

    Møller, Per; Boyce, Jan M.; Nielsen, Lars Pleth

    2013-01-01

    . The main focus will be on the corrosion properties where the following corrosion investigations will be covered; corrosion potential measurements for the different coatings, estimation of corrosion rates for materials in galvanic coupling with tin/nickel coatings, salt spray test, medical tests...

  4. THE EFFECT OF SINGLE NICKEL AND COMBINED NICKEL AND ZINC PERORAL ADMINISTRATION ON HAEMATOLOGICAL PARAMETERS IN RABBITS

    Directory of Open Access Journals (Sweden)

    Jana Emrichová

    2013-06-01

    Full Text Available The aim of this study was to determine the effect of single nickel (NiCl2 and nickel in combination with zinc (ZnCl2 on selected haematological parameters of rabbits: white blood cell, red blood cell, haemoglobin, haematocrit, mean corpuscular volume, mean corpuscular haemoglobin, mean corpuscular haemoglobin concentration, platelets, mean platelet volume, red cell distribution width, lymphocytes, monocytes, eosinophils, neutrophils, basophils. Twenty rabbits of broiler line Californian were used in this experiment. The animals were divided into the five groups, four animals in each ones (control group K and experimental groups E1, E2, E3 and E4. Animals were fed ad libitum using KKV1 feeding mixture (FM with or without nickel and zinc addition for 90 days follows: group E1 received 17.5 g of NiCl2.100 kg-1 FM; group E2 35 g NiCl2.100 kg-1 FM; group E3 17.5 g NiCl2 + 30 g ZnCl2.100 kg-1 FM and group E4 35 g NiCl2 + 30 g ZnCl2.100 kg-1 FM. The parameters were analysed using Advia – 120. Blood was collected into tubes containing anticoagulant agents K – EDTA. Statistical analyse showed a significant changes (P 0.05. Nickel has negative effect on some haematological parameters, but zinc can eliminates its influence.

  5. Nickel, Lead and Zinc Contamination in the Surface Sediments of Agh Gel Wetland, Iran

    Directory of Open Access Journals (Sweden)

    Soheil Sobhan Ardakani

    2016-07-01

    Full Text Available Background & Aims of the Study: Due to the increased human activities around the Agh Gel wetland, this study aimed to measured accumulations of heavy metals (Ni, Pb and Zn in the surface sediment samples taken from this wetland. Materials & Methods: Samples were taken from 10 stations and exposed to bulk digestion and chemical partitioning. Finally, Ni, Pb and Zn concentrations were monitored with ICP-OES in the sediments. Also, geo-accumulation index, contamination factor and pollution load index were used to evaluate the magnitude of contaminants in the sediment profile. Results: The results showed, the average of metal concentration in samples (mg kg-1 wet weight were 34.20±3.58 for Ni, 25.37±2.52 for Pb and 127.20±15.21 for Zn, respectively. Therefore, the pattern of metal concentrations in sediment was determined as Zinc>Nickel >Lead. According to the mean I-geo values, sediments' qualities are classified as unpolluted category for Ni and Pb. Also, sediment's quality is classified as unpolluted to moderately polluted for Zn. The CF values for all elements are classified as moderate contamination. The PLI values indicated that metal pollution exists for all sampling stations. Conclusions: The obtained results indicated that the Agh Gel wetland has a potential to threaten by chemical pollutants such as agricultural effluent. So, in order to preserve the environment of the Agh Gel wetland from deterioration, monitoring of water and sediment qualities is recommended periodically.

  6. L-carnitine protects against nickel-induced neurotoxicity by maintaining mitochondrial function in Neuro-2a cells

    International Nuclear Information System (INIS)

    He Mindi; Xu Shangcheng; Lu Yonghui; Li Li; Zhong Min; Zhang Yanwen; Wang Yuan; Li Min; Yang Ju; Zhang Guangbin; Yu Zhengping; Zhou Zhou

    2011-01-01

    Mitochondrial dysfunction is thought to be a part of the mechanism underlying nickel-induced neurotoxicity. L-carnitine (LC), a quaternary ammonium compound biosynthesized from the amino acids lysine and methionine in all mammalian species, manifests its neuroprotective effects by improving mitochondrial energetics and function. The purpose of this study was to investigate whether LC could efficiently protect against nickel-induced neurotoxicity. Here, we exposed a mouse neuroblastoma cell line (Neuro-2a) to different concentrations of nickel chloride (NiCl 2 ) (0.25, 0.5, 1, and 2 mM) for 24 h, or to 0.5 mM and 1 mM NiCl 2 for various periods (0, 3, 6, 12, or 24 h). We found that nickel significantly increased the cell viability loss and lactate dehydrogenase (LDH) release in Neuro-2a cells. In addition, nickel exposure significantly elevated reactive oxygen species (ROS) and malondialdehyde (MDA) levels, disrupted the mitochondrial membrane potential (ΔΨ m ), reduced adenosine-5'-triphosphate (ATP) concentrations and decreased mitochondrial DNA (mtDNA) copy numbers and mtRNA transcript levels. However, all of the cytotoxicities and mitochondrial dysfunctions that were triggered by nickel were efficiently attenuated by pretreatment with LC. These protective effects of LC may be attributable to its role in maintaining mitochondrial function in nickel-treated cells. Our results suggest that LC may have great pharmacological potential in protecting against the adverse effects of nickel in the nervous system.

  7. Predicting patient exposure to nickel released from cardiovascular devices using multi-scale modeling.

    Science.gov (United States)

    Saylor, David M; Craven, Brent A; Chandrasekar, Vaishnavi; Simon, David D; Brown, Ronald P; Sussman, Eric M

    2018-04-01

    Many cardiovascular device alloys contain nickel, which if released in sufficient quantities, can lead to adverse health effects. However, in-vivo nickel release from implanted devices and subsequent biodistribution of nickel ions to local tissues and systemic circulation are not well understood. To address this uncertainty, we have developed a multi-scale (material, tissue, and system) biokinetic model. The model links nickel release from an implanted cardiovascular device to concentrations in peri-implant tissue, as well as in serum and urine, which can be readily monitored. The model was parameterized for a specific cardiovascular implant, nitinol septal occluders, using in-vitro nickel release test results, studies of ex-vivo uptake into heart tissue, and in-vivo and clinical measurements from the literature. Our results show that the model accurately predicts nickel concentrations in peri-implant tissue in an animal model and in serum and urine of septal occluder patients. The congruity of the model with these data suggests it may provide useful insight to establish nickel exposure limits and interpret biomonitoring data. Finally, we use the model to predict local and systemic nickel exposure due to passive release from nitinol devices produced using a wide range of manufacturing processes, as well as general relationships between release rate and exposure. These relationships suggest that peri-implant tissue and serum levels of nickel will remain below 5 μg/g and 10 μg/l, respectively, in patients who have received implanted nitinol cardiovascular devices provided the rate of nickel release per device surface area does not exceed 0.074 μg/(cm 2  d) and is less than 32 μg/d in total. The uncertainty in whether in-vitro tests used to evaluate metal ion release from medical products are representative of clinical environments is one of the largest roadblocks to establishing the associated patient risk. We have developed and validated a multi

  8. Importance of nickel in Fabaceae. Pt. 1. Comparative studies on the content of nickel and certain other elements in vegetative parts and seeds

    Energy Technology Data Exchange (ETDEWEB)

    Horak, O

    1985-02-28

    Vegetative parts and seeds of 15 Fabaceae were analyzed with respect to concentrations of Ni as well as K, Ca, Mg, Fe, Mn, Zn, Cu and Mo. The distribution pattern of the examined elements is different. For the macronutrients and iron mostly a significant higher concentration could be found in the shoot, whilst micronutrients frequently were accumulated in the seed. Nickel is that element, which is accumulated relatively highest in the seed. This is a criterion for a specific importance of nickel, which is a compound of urease and in this function could be involved in the mobilization of nitrogen storage substances of the seed.

  9. Nickel exposure promotes osmoregulatory disturbances in Oreochromis niloticus gills: histopathological and energy dispersive spectrometry analysis.

    Science.gov (United States)

    Marcato, A C C; Yabuki, A T; Fontanetti, C S

    2014-11-01

    Water is an essential factor for maintaining the vital functions of living beings. Nickel is the 24th most abundant element on Earth; it is a heavy metal that is genotoxic and mutagenic in its chloride form. Due to industrial use, its concentration in surface sediments increased considerably. Fish develop characteristics that make them excellent experimental models for studying aquatic toxicology. They are particularly useful because they can alert of the potential danger of chemical substances or environmental pollution. Due to water quality impairment and because there are few published studies that relate nickel to tissue alteration, this study aimed to examine the consequences of nickel in an aquatic environment. For this analysis, individuals of Oreochromis niloticus were exposed for 96 h to three different concentrations of nickel dissolved in water according to the standard established by Brazilian law and compared them to a control group. After exposure, the gills were analyzed using X-ray microanalysis, ultramorphology, and histological and histochemical analysis. The results demonstrated that all the concentrations used in the experiment altered the histophysiology of the individuals exposed. In conclusion, the nickel presents a toxic potential to fish, even at the lowest concentration tested, which is equivalent to half of the concentration allowed by law. The CONAMA resolution should be revised for this parameter because of the interference of this metal in the histophysiology of the tested organism.

  10. Allergic contact dermatitis due to nickel in household detergent

    Directory of Open Access Journals (Sweden)

    Dewi Utami Putri

    2017-12-01

    Full Text Available Allergic contact dermatitis (ACD is a cutaneous inflammatory reaction caused by contact with specific exogenous allergen to which a person has developed allergic sensitization. Nickel was reported as one of the most common causes of ACD worldwide, particularly affecting females. It is associated with a variety of nickel-containing products, from jewelry to detergent. A 32-year-old female was presented with pruritic eruption consist of erythematous papules and vesicles on both hands and extensor forearms since 2 weeks before admission. The patient is a housewife who did handwashing clothes and kitchenware with detergent and soap every day. At first, there were erythematous papules on the right extensor forearm, then the patient wore rubber gloves to protect hands when washing. However, the lesions spread to the left extensor forearm and there were also vesicles on both hands. There was history of localized reactions to metal items, the latter one was 3 weeks ago after wearing a metal necklace. The clinical presentation were multiple erythematous papules and vesicles, erythematous and hyperpigmented macules. The patch test using Chemotechnique Diagnostics AB and square chamber showed a 2+ reaction to nickel sulfate. The patient was educated to avoid the causative allergen and treated with oral antihistamine and topical corticosteroid. The patient showed significant clinical improvement after 2 weeks. Nickel as metal catalyst used in detergents is found in small concentration, but can lead to ACD in an already sensitized individual.The lesions persist despite the use of gloves because nickel is absorbed through rubber materia

  11. Preparation of one-dimensional nickel nanowires by self-assembly process

    International Nuclear Information System (INIS)

    Wang Dapeng; Sun Dongbai; Yu Hongying; Qiu Zhigang; Meng Huimin

    2009-01-01

    Self-assembly nickel nanowires were prepared by soft template method in ethylene glycol solutions. The structure and micro-morphology of the products were analyzed using X-ray diffraction (XRD) and field emission scanning electron microscope (FESEM). The results showed that the products were pure nickel powders with face-centered cubic (fcc) structure. A growth model was presented to explain the growth mechanism. The effects of pH value, surfactant, reaction temperature and reaction time on the synthesis of nickel nanowires were discussed. When pH > 11.5, the reaction temperature was between 80 deg. C and 90 deg. C, and the concentration of cetyltrimethyl ammonium bromide (CTAB) was higher than 7.0 x 10 -3 , zigzag nickel nanowires with slenderness ratio about 20 could be synthesized

  12. Synthesis of Nickel and Nickel Hydroxide Nano powders by Simplified Chemical Reduction

    International Nuclear Information System (INIS)

    Tientong, J.; Garcia, S.; Thurber, C.R.; Golden, T.D.

    2014-01-01

    Nickel nano powders were synthesized by a chemical reduction of nickel ions with hydrazine hydrate at ph ∼ 12.5. Sonication of the solutions created a temperature of 54-65 °C to activate the reduction reaction of nickel nanoparticles. The solution ph affected the composition of the resulting nanoparticles. Nickel hydroxide nanoparticles were formed from an alkaline solution (ph ∼10) of nickel-hydrazine complexed by dropwise titration. X-ray diffraction of the powder and the analysis of the resulting Williamson-Hall plots revealed that the particle size of the powders ranged from 12 to 14 nm. Addition of polyvinylpyrrolidone into the synthesis decreased the nickel nanoparticle size to approximately 7 nm. Dynamic light scattering and scanning electron microscopy confirmed that the particles were in the nanometer range. The structure of the synthesized nickel and nickel hydroxide nanoparticles was identified by X-ray diffraction and Fourier transform infrared spectroscopy.

  13. Nickel and cobalt base alloys

    International Nuclear Information System (INIS)

    Houlle, P.

    1994-01-01

    Nickel base alloys have a good resistance to pitting, cavernous or cracks corrosion. Nevertheless, all the nickel base alloys are not equivalent. Some differences exit between all the families (Ni, Ni-Cu, Ni-Cr-Fe, Ni-Cr-Fe-Mo/W-Cu, Ni-Cr-Mo/W, Ni-Mo). Cobalt base alloys in corrosive conditions are generally used for its wear and cracks resistance, with a compromise to its localised corrosion resistance properties. The choice must be done from the perfect knowledge of the corrosive medium and of the alloys characteristics (chemical, metallurgical). A synthesis of the corrosion resistance in three medium (6% FeCl 3 , 4% NaCl + 1% HCl + 0.1% Fe 2 (SO 4 ) 3 , 11.5% H 2 SO 4 + 1.2% HCl + 1% Fe 2 (SO 4 ) 3 + 1% CuCl 2 ) is presented. (A.B.). 11 refs., 1 fig., 12 tabs

  14. Nickel-Hydrogen Battery Reconditioning

    Science.gov (United States)

    Levine, Erik L.

    1997-01-01

    Reconditioning has traditionally been used as a means of maintaining the performance of normal cells and batteries. This paper describes methods and results in which reconditioning was used to improve the performance of nickel-hydrogen batteries. The following method are discussed: (1) SS/L reconditioning implementation; (2) Superbird reconditioning - pressure/capacity growth; (3) INTELSAT 7/7A reconditioning - cell voltage plateaus and life testing; and (4) N-Star reconditioning - cell voltage plateaus (capacity fading and recovery).

  15. Nickel and vanadium in air particulates at Dhahran (Saudi Arabia) during and after the Kuwait oil fires

    Science.gov (United States)

    Sadiq, M.; Mian, A. A.

    Air particulates, both the total suspended (TSP) and inhalable (PM 10, smaller than 10 microns in size), were collected during and after the Kuwait oil fires (from March 1991 to July 1992) using Hi-Vol samplers. These samples were wet-digested at 120°C in an aqua regia and perchloric acids mixture for 3 h. Air particulate samples collected in 1982 at the same location were prepared similarly. Concentrations of nickel and vanadium were determined in the aliquot samples using an inductively coupled argon plasma analyser (ICAP). The monthly mean concentrations of nickel and vanadium, on volume basis, increased rapidly from March to June and decreased sharply during July-August in 1991. The minimum mean concentrations of these elements were found in the particulate samples collected in December 1991 which gradually increased through May 1992. Like 1991, nickel and vanadium concentrations in the air particulates spiked in June and decreased again in July 1992. This distribution pattern of nickel and vanadium concentrations was similar to that of the predominant wind from the north (Kuwait). In general, concentrations of these elements were higher in the air particulates collected during April-July 1991 as compared with those collected in 1992 during the same period. The TSPs contained higher concentrations of nickel and vanadium than those found in the PM 10 samples. However, this trend was reversed when concentrations of nickel and vanadium, on were expressed on particulate weight basis. The monthly mean concentrations of nickel and vanadium, on weight basis, decreased gradually through 1991 and increased slightly from March to July 1992. Concentrations of these elements were significantly higher in the air particulate samples collected in 1991 than those samples collected during 1982 at the same location. The data of this study suggest a contribution of the Kuwait oil fires in elevating nickel and vanadium concentrations in the air particulates at Dhahran during

  16. Liquid Membranes as a Tool for Chemical Speciation of Metals in Natural Waters: Organic and Inorganic Complexes of Nickel.

    Science.gov (United States)

    Vergel, Cristina; Mendiguchía, Carolina; Moreno, Carlos

    2018-04-15

    The different species of nickel present in natural waters exhibit different transport behaviour through bulk liquid membranes (BLMs). This fact has been used to design and optimise a separation/pre-concentration system applicable to separate labile and non-labile nickel fractions. A hydrazone derivative-1,2-cyclohexanedione bis-benzoyl-hydrazone (1,2-CHBBH) dissolved in toluene/dimethyl formamide (2% DMF)-was used as a chemical carrier of nickel species, from an aqueous source solution (sample) to a receiving acidic solution. Both chemical and hydrodynamic conditions controlling the transport system were studied and optimised. Under optimum conditions, variations in the transport of nickel ions as a function of organic (humic acids) and inorganic (chloride ions) ligands were studied. Relationships between the permeability coefficient ( P ) or recovery efficiency (%R) and the concentrations of ligands and nickel species were analysed using Winhumic V software. A negative correlation between P and the concentration of organic nickel complexes was found, suggesting that only labile nickel species are transported through the liquid membrane, with non-labile complexes remaining in the water sample; allowing for their separation and subsequent quantification in natural waters.

  17. Liquid Membranes as a Tool for Chemical Speciation of Metals in Natural Waters: Organic and Inorganic Complexes of Nickel

    Directory of Open Access Journals (Sweden)

    Cristina Vergel

    2018-04-01

    Full Text Available The different species of nickel present in natural waters exhibit different transport behaviour through bulk liquid membranes (BLMs. This fact has been used to design and optimise a separation/pre-concentration system applicable to separate labile and non-labile nickel fractions. A hydrazone derivative—1,2-cyclohexanedione bis-benzoyl-hydrazone (1,2-CHBBH dissolved in toluene/dimethyl formamide (2% DMF—was used as a chemical carrier of nickel species, from an aqueous source solution (sample to a receiving acidic solution. Both chemical and hydrodynamic conditions controlling the transport system were studied and optimised. Under optimum conditions, variations in the transport of nickel ions as a function of organic (humic acids and inorganic (chloride ions ligands were studied. Relationships between the permeability coefficient (P or recovery efficiency (%R and the concentrations of ligands and nickel species were analysed using Winhumic V software. A negative correlation between P and the concentration of organic nickel complexes was found, suggesting that only labile nickel species are transported through the liquid membrane, with non-labile complexes remaining in the water sample; allowing for their separation and subsequent quantification in natural waters.

  18. Flare up of Nickel Contact Dermatits Following Oral Challenge

    Directory of Open Access Journals (Sweden)

    C R Srinivas

    1988-01-01

    Full Text Available A patient having contact dermatitis due to nickel on the wrist, sides of neck, thighs and legs, confirmed by patch tests with nickel sulphate, showed aggravation of the dermatitis following oral provocation with 25 mg nickel sulphate.

  19. Copper, Aluminum and Nickel: A New Monocrystalline Orthodontic Alloy

    Science.gov (United States)

    Wierenga, Mark

    Introduction: This study was designed to evaluate, via tensile and bend testing, the mechanical properties of a newly-developed monocrystalline orthodontic archwire comprised of a blend of copper, aluminum, and nickel (CuAlNi). Methods: The sample was comprised of three shape memory alloys; CuAlNi, copper nickel titanium (CuNiTi), and nickel titanium (NiTi); from various orthodontic manufacturers in both 0.018" round and 0.019" x 0.025" rectangular dimensions. Additional data was gathered for similarly sized stainless steel and beta-titanium archwires as a point of reference for drawing conclusions about the relative properties of the archwires. Measurements of loading and unloading forces were recorded in both tension and deflection testing. Repeated-measure ANOVA (alpha= 0.05) was used to compare loading and unloading forces across wires and one-way ANOVA (alpha= 0.05) was used to compare elastic moduli and hysteresis. To identify significant differences, Tukey post-hoc comparisons were performed. Results: The modulus of elasticity, deflection forces, and hysteresis profiles of CuAlNi were significantly different than the other superelastic wires tested. In all tests, CuAlNi had a statistically significant lower modulus of elasticity compared to the CuNiTi and NiTi wires (P orthodontic metallurgy.

  20. Defect structure in proton-irradiated copper and nickel

    International Nuclear Information System (INIS)

    Tsukuda, Noboru; Ehrhart, P.; Jaeger, W.; Schilling, W.; Dworschak, F.; Gadalla, A.A.

    1987-01-01

    This single crystals of copper or nickel with a thickness of about 10 μm are irradiated with 3 MeV protons at room temperature and the structures of resultant defects are investigated based on measurements of the effects of irradiation on the electrical resistivity, length, lattice constants, x-ray diffraction line profile and electron microscopic observations. The measurements show that the electrical resistivity increases with irradiation dose, while leveling off at high dose due to overlapping of irradiation cascades. The lattice constants decreases, indicating that many vacancies still remain while most of the interstitial stoms are eliminated, absorbed or consumed for dislocation loop formation. The x-ray line profile undergoes broadening, which is the result of dislocation loops, dislocation networks and SFT's introduced by the proton irradiation. Various defects have different effects though they cannot be identified separately from the profile alone. A satellite peak appears at a low angle, which seems to arise from periodic defect structures that are found in electron microscopic observations. In both copper and nickel, such periodic defect structures are seen over a wide range from high to low dose. Defect-free and defect-rich domains (defect walls), 0.5 to several μm in size, are alingned parallel to the {001} plane at intervals of 60 nm. The defect walls, which consist of dislocations, dislocation loops and SFT's, is 20 - 40 nm thick. (Nogami, K.)

  1. Air Force standards for nickel hydrogen battery

    Science.gov (United States)

    Hwang, Warren; Milden, Martin

    1994-01-01

    The topics discussed are presented in viewgraph form and include Air Force nickel hydrogen standardization goals, philosophy, project outline, cell level standardization, battery level standardization, and schedule.

  2. Nickel-hydrogen bipolar battery system

    Science.gov (United States)

    Thaller, L. H.

    1982-01-01

    Rechargeable nickel-hydrogen systems are described that more closely resemble a fuel cell system than a traditional nickel-cadmium battery pack. This was stimulated by the currently emerging requirements related to large manned and unmanned low Earth orbit applications. The resultant nickel-hydrogen battery system should have a number of features that would lead to improved reliability, reduced costs as well as superior energy density and cycle lives as compared to battery systems constructed from the current state-of-the-art nickel-hydrogen individual pressure vessel cells.

  3. On the reflectivity of nickel neutron mirrors

    Energy Technology Data Exchange (ETDEWEB)

    Adib, M.; Maayouf, R.M.A.; Abdel-Kawy, A.; Habib, N. (Atomic Energy Establishment, Cairo (Egypt). Reactor and Neutron Physics Dept.); Kenawy, M.A.; Wahba, M.; Ashry, A.H. (Ain Shams Univ., Cairo (Egypt))

    1991-02-01

    Neutron reflectivities were determined for 300 nm thick films of natural nickel and nickel 58 coated on glass plates. The measurements were performed at glancing angles between 40' and 60'. The incident neutron beam from one of the ET-RR-1 reactor horizontal channels covered neutron wavelengths between 0.55 and 0.80 nm. It was found that nickel 58, because of the high value of its critical glancing angle, is more efficient as a neutron mirror than natural nickel. (orig.).

  4. METHOD OF APPLYING NICKEL COATINGS ON URANIUM

    Science.gov (United States)

    Gray, A.G.

    1959-07-14

    A method is presented for protectively coating uranium which comprises etching the uranium in an aqueous etching solution containing chloride ions, electroplating a coating of nickel on the etched uranium and heating the nickel plated uranium by immersion thereof in a molten bath composed of a material selected from the group consisting of sodium chloride, potassium chloride, lithium chloride, and mixtures thereof, maintained at a temperature of between 700 and 800 deg C, for a time sufficient to alloy the nickel and uranium and form an integral protective coating of corrosion-resistant uranium-nickel alloy.

  5. [Nickel levels in female dermatological patients].

    Science.gov (United States)

    Schwegler, U; Twardella, D; Fedorov, M; Darsow, U; Schaller, K-H; Habernegg, R; Behrendt, H; Fromme, H

    2009-07-01

    Nickel levels in urine were determined among 163 female dermatological patients aged 18 to 46 years. Data on life-style factors were collected in parallel via a questionnaire. Urinary nickel excretion was in the normal range of the German female population (0.2-46.1 microg Ni/g creatinine). The 95th percentile (3.9 microg Ni/l urine) exceeded the German reference value (3.0 microg Ni/l urine). In the multivariate regression analyses we found a statistically significant increase of ln-transformed nickel levels with increase in age and in women using dietary supplements. The following variables were not associated with Nickel urine levels: suffering from nickel eczema, smoking, drinking stagnated water, eating foods with high nickel contents and using nickel-containing kitchen utensils as, for example, an electric kettle with an open heater coil. We conclude that personal urinary levels should be assessed with simultaneous consideration of habits and life-style factors. A German national survery would be useful. Those patients who experience the exacerbation of their eczema in cases of oral provocation, for example, by a high nickel diet should be aware of potential sources of nickel, such as supplements.

  6. Stainless steel leaches nickel and chromium into foods during cooking.

    Science.gov (United States)

    Kamerud, Kristin L; Hobbie, Kevin A; Anderson, Kim A

    2013-10-02

    Toxicological studies show that oral doses of nickel and chromium can cause cutaneous adverse reactions such as dermatitis. Additional dietary sources, such as leaching from stainless steel cookware during food preparation, are not well characterized. This study examined stainless steel grades, cooking time, repetitive cooking cycles, and multiple types of tomato sauces for their effects on nickel and chromium leaching. Trials included three types of stainless steels and a stainless steel saucepan, cooking times of 2-20 h, 10 consecutive cooking cycles, and four commercial tomato sauces. After a simulated cooking process, samples were analyzed by ICP-MS for Ni and Cr. After 6 h of cooking, Ni and Cr concentrations in tomato sauce increased up to 26- and 7-fold, respectively, depending on the grade of stainless steel. Longer cooking durations resulted in additional increases in metal leaching, where Ni concentrations increased 34-fold and Cr increased approximately 35-fold from sauces cooked without stainless steel. Cooking with new stainless steel resulted in the largest increases. Metal leaching decreases with sequential cooking cycles and stabilized after the sixth cooking cycle, although significant metal contributions to foods were still observed. The tenth cooking cycle resulted in an average of 88 μg of Ni and 86 μg of Cr leached per 126 g serving of tomato sauce. Stainless steel cookware can be an overlooked source of nickel and chromium, where the contribution is dependent on stainless steel grade, cooking time, and cookware usage.

  7. Stainless Steel Leaches Nickel and Chromium into Foods During Cooking

    Science.gov (United States)

    Kamerud, Kristin L.; Hobbie, Kevin A.; Anderson, Kim A.

    2014-01-01

    Toxicological studies show that oral doses of nickel and chromium can cause cutaneous adverse reactions such as dermatitis. Additional dietary sources, such as leaching from stainless steel cookware during food preparation, are not well characterized. This study examined stainless steel grades, cooking time, repetitive cooking cycles, and multiple types of tomato sauces for their effects on nickel and chromium leaching. Trials included three types of stainless steels and a stainless steel saucepan; cooking times of 2 to 20 hours, ten consecutive cooking cycles, and four commercial tomato sauces. After a simulated cooking process, samples were analyzed by ICP-MS for Ni and Cr. After six hours of cooking, Ni and Cr concentrations in tomato sauce increased up to 26- and 7-fold respectively, depending on the grade of stainless steel. Longer cooking durations resulted in additional increases in metal leaching, where Ni concentrations increased 34 fold and Cr increased approximately 35 fold from sauces cooked without stainless steel. Cooking with new stainless steel resulted in the largest increases. Metal leaching decreases with sequential cooking cycles and stabilized after the sixth cooking cycle, though significant metal contributions to foods were still observed. The tenth cooking cycle, resulted in an average of 88 μg of Ni and 86 μg of Cr leached per 126 g serving of tomato sauce. Stainless steel cookware can be an overlooked source of nickel and chromium, where the contribution is dependent on stainless steel grade, cooking time, and cookware usage. PMID:23984718

  8. Risk assessment of nickel carcinogenicity and occupational lung cancer.

    OpenAIRE

    Shen, H M; Zhang, Q F

    1994-01-01

    Recent progress in risk assessment of nickel carcinogenicity and its correlation with occupational lung cancer in nickel-exposed workers is reviewed. Epidemiological investigations provide reliable data indicating the close relation between nickel exposure and high lung cancer risk, especially in nickel refineries. The nickel species-specific effects and the dose-response relationship between nickel exposure and lung cancer are among the main questions that are explored extensively. It is als...

  9. Studies on magneto conductance of nickel substituted FeSi

    Science.gov (United States)

    Krishnan, M.; Mishra, Ashish; Singh, Durgesh; Yadam, Sankararao; Venkatesh, R.; Gangrade, Mohan; Ganesan, V.

    2018-02-01

    Structural and electrical transport properties of Nickel (Ni) doped FeSi at low temperatures in the presence of zero and high magnetic fields are investigated systematically and reported. FeSi is a material known for its high thermoelectric power. Metal-Insulator Transition in FeSi is always an exotic one with different ground states depending upon the substituent. Changes in Magneto Resistance (MR) at low temperatures are explained by invoking an interplay between Weak Localization (WL) and enhanced Electron-Electron Interaction (EEI) that evolved upon varying the nickel concentrations. Competing interactions between WL and EEI along with Kondo hybridization scenario may classify this system into an exotic one among doped semiconductors. Temperature dependent zero field resistivity is analyzed in the light of various scattering mechanism in different doping regimes at low temperatures. Different crossover regimes are explained by invoking carriers and magnetic moments induced by the Ni impurity in an otherwise non-magnetic Kondo Insulator (KI).

  10. Nickel/Diamond Composite Coating Prepared by High Speed Electrodeposition

    Directory of Open Access Journals (Sweden)

    ZHANG Yan

    2016-10-01

    Full Text Available Nickel/diamond composite coatings were prepared on the basis of a new high speed electroplating bath. The influence of additives, plating parameters and diamond concentration on internal stress was investigated in order to find the solution to decrease the stress introduced by high current density; the micro morphology of the coatings were observed by SEM. The bath and depositing parameters were optimized that thick nickel/diamond composite coatings with low internal stress can be high speed electroplated with a high cathode current density of 30A/dm2. The results show that when plated with bath composition and parameters as follows: sodium dodecyl sulfate 0.5g/L, ammonium acetate 3g/L, sodium citrate 1.5g/L, diamond particles 30g/L; pH value 3-4, temperature 50℃, the composite coatings prepared in high speed have the lowest internal stress.

  11. Proteomic Assessment of Biochemical Pathways That Are Critical to Nickel-Induced Toxicity Responses in Human Epithelial Cells

    Science.gov (United States)

    Ge, Yue; Bruno, Maribel; Haykal-Coates, Najwa; Wallace, Kathleen; Andrews, Debora; Swank, Adam; Winnik, Witold; Ross, Jeffrey A.

    2016-01-01

    Understanding the mechanisms underlying toxicity initiated by nickel, a ubiquitous environmental contaminant and known human carcinogen is necessary for proper assessment of its risks to human and environment. Among a variety of toxic mechanisms, disruption of protein responses and protein response-based biochemical pathways represents a key mechanism through which nickel induces cytotoxicity and carcinogenesis. To identify protein responses and biochemical pathways that are critical to nickel-induced toxicity responses, we measured cytotoxicity and changes in expression and phosphorylation status of 14 critical biochemical pathway regulators in human BEAS-2B cells exposed to four concentrations of nickel using an integrated proteomic approach. A subset of the pathway regulators, including interleukin-6, and JNK, were found to be linearly correlated with cell viability, and may function as molecular determinants of cytotoxic responses of BEAS-2B cells to nickel exposures. In addition, 128 differentially expressed proteins were identified by two dimensional electrophoresis (2-DE) and mass spectrometry. Principal component analysis, hierarchical cluster analyses, and ingenuity signaling pathway analysis (IPA) identified putative nickel toxicity pathways. Some of the proteins and pathways identified have not previously been linked to nickel toxicity. Based on the consistent results obtained from both ELISA and 2-DE proteomic analysis, we propose a