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Sample records for cu manganese mn

  1. Dietary manganese source does not affect Mn, Zn and Cu tissue deposition and the activity of manganese-containing enzymes in lambs.

    Science.gov (United States)

    Gresakova, Lubomira; Venglovska, Katarina; Cobanova, Klaudia

    2016-12-01

    Manganese (Mn) is a trace element required for normal physiological processes in animals and humans. Organic forms of trace elements are expected to have higher bioavailability in comparison with inorganic sources. The effect of feeding a diet supplemented with different sources of manganese to lambs was studied in a 112-d feeding trial. The aim of this study was to investigate the deposition of Mn in relation to activities of superoxide dismutase (SOD), manganese superoxide dismutase (MnSOD) and arginase in the tissues of lambs fed the diet supplemented with an inorganic or an organic source of manganese up to the maximum total Mn content allowed in the European Union (150mg Mn/kg). A total of eighteen female lambs of the improved Valachian breed were randomly allocated to three dietary treatments and fed an unsupplemented basal diet (Control, 31mg Mn/kg) or the identical diet supplemented with manganese sulphate (MnSO4) or manganese chelate of glycine hydrate (Mn-Gly) with a total Mn content up to 150mg/kg. Regardless of the source, feed supplementation with manganese increased Mn concentrations in plasma (P˂0.05) and the liver (P˂0.001) as well as the activity of liver MnSOD (P˂0.05) and arginase (P˂0.001) compared with the control lambs. In the kidney cortex, the concentration of Mn was greatest in lambs fed the diet supplemented with the chelated Mn source compared with animals receiving the inorganic Mn source (P˂0.05) and the unsupplemented diet (P˂0.001). The 112-d intake of feed enriched with manganese did not result in any change in Mn levels, SOD or MnSOD activity in pancreas and kidney tissues. Plasma Cu concentration was depressed in both supplemented treatments. No analyzed tissue showed a change in zinc and copper levels, except the greater Cu concentration in the liver of lambs fed the diet with Mn-Gly. The presented results did not indicate any differences between dietary Mn sources either in Mn tissue deposition or activity of SOD, MnSOD and

  2. Enhanced catalytic toluene oxidation by interaction between copper oxide and manganese oxide in Cu-O-Mn/γ-Al2O3 catalysts

    Science.gov (United States)

    Wang, Hongpei; Lu, Yiyuan; Han, YuXiang; Lu, Chunliang; Wan, Haiqin; Xu, Zhaoyi; Zheng, Shourong

    2017-10-01

    Toward catalytic oxidation of toluene, Cu-O-Mn/γ-Al2O3 catalysts with series molar ratios of Cu/Mn were prepared using an impregnation method. The surface structure and chemical state of the as-prepared catalysts were characterized by the combination of X-ray diffraction (XRD), N2 adsorption/desorption, UV-vis spectroscopy (UV-vis), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and H2 temperature programmed reduction (H2-TPR). The results demonstrated that copper oxide and manganese oxide were highly dispersed on the γ-Al2O3 support. Meanwhile, there is an interaction between copper oxide and manganese oxide, depending on the atomic ratio of Cu/Mn. At the ratio of Cu/Mn = 1:1.5, the interaction between Cu and Mn oxides reached the strongest, thus leading to the highest catalytic activity and turn over frequency among all of the ratios. The temperature for complete combustion of toluene over the strongest interaction sample could be 350 °C, which could further decrease to 300 °C when tuning the loading amount of Cu and Mn. Findings in this work are important for the design of efficient catalyst by tuning the interaction between each components.

  3. Variability of Mn, Fe, Ni, Cu and Co in manganese nodules from the Central Indian Ocean Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Jauhari, P.

    the siliceous sediments where the plots are more scattered. The variations in the Mn/Fe ratio reflect variability in the composition of bottom water which in turn influences the type of underlying sediments and supply of metal to the deposits. The higher...

  4. Dietary Manganese Modulates PCB126 Toxicity, Metal Status, and MnSOD in the Rat.

    Science.gov (United States)

    Wang, Bingxuan; Klaren, William D; Wels, Brian R; Simmons, Donald L; Olivier, Alicia K; Wang, Kai; Robertson, Larry W; Ludewig, Gabriele

    2016-03-01

    PCB126 (3,3',4,4',5-pentachlorobiphenyl) is a potent aryl hydrocarbon receptor agonist and induces oxidative stress. Because liver manganese (Mn) levels decrease in response to PCB126, a Mn dietary study was designed to investigate the role of Mn in PCB126 toxicity. Male Sprague Dawley rats received diets containing 0, 10, or 150 ppm added Mn for 3 weeks, followed by a single ip injection of corn oil or PCB126 (5 µmol/kg body weight). After 2 weeks, Mn, Cu, Zn, and Fe levels in the heart, liver, and liver mitochondria, and Mn-containing superoxide dismutase (MnSOD) and metallothionein mRNA, MnSOD protein, and MnSOD activity were determined. Mn levels in liver, heart, and liver mitochondria were strongly decreased by the Mn-deficient diet. Small effects on Fe levels and a stepwise increase in MnSOD activity with dietary Mn were also visible. PCB126 caused profound changes in Cu (up), Zn, Fe, and Mn (down) in liver, but not in heart, and differing effects (Cu, Zn, and Fe up, Mn down) in liver mitochondria. Liver MnSOD and metallothionein mRNA levels and MnSOD protein were increased but MnSOD activity was decreased by PCB126. PCB126-induced liver enlargement was dose-dependently reduced with increasing dietary Mn. These changes in metals homeostasis and MnSOD activity in liver but not heart may be a/the mechanism of PCB126 liver-specific toxicity. Specifically, transport of Fenton metals (Cu, Fe) into and Mn out of the mitochondria, a probable mechanism for lower MnSOD activity, may be a/the cause of PCB126-induced oxidative stress. The role of metallothioneins needs further evaluation. Dietary Mn slightly alleviated PCB126-induced toxicities.

  5. Regulation of Copper Transport Crossing Brain Barrier Systems by Cu-ATPases: Effect of Manganese Exposure

    OpenAIRE

    Fu, Xue; Zhang, Yanshu; Jiang, Wendy; Monnot, Andrew Donald; Bates, Christopher Alexander; Zheng, Wei

    2014-01-01

    Regulation of cellular copper (Cu) homeostasis involves Cu-transporting ATPases (Cu-ATPases), i.e., ATP7A and ATP7B. The question as to how these Cu-ATPases in brain barrier systems transport Cu, i.e., toward brain parenchyma, cerebrospinal fluid (CSF), or blood, remained unanswered. This study was designed to characterize roles of Cu-ATPases in regulating Cu transport at the blood-brain barrier (BBB) and blood-CSF barrier (BCB) and to investigate how exposure to toxic manganese (Mn) altered ...

  6. A historical overview of the development of manganese (Mn) ...

    Science.gov (United States)

    Abstract for Manganese 2016A historical overview of the development of manganese (Mn) pharmacokinetic data under Section 211(b) of the Clean Air Act (CAA)William K BoyesBackground. In the 1990’s, the use of methylcyclopentadienyl manganese tricarbonyl (MMT) as an octane-enhancing gasoline fuel additive led to concerns for potential public health consequences from exposure to Mn combustion products in automotive exhaust. Methods: After a series of regulatory / legal actions and negotiations, the EPA issued under CAA 211(b) an Alternative Tier 2 Test Rule that required development of scientific information intended to help resolve uncertainties in exposure or health risk estimates associated with MMT use. Among the uncertainties identified were: the chemical forms of Mn emitted in automotive exhaust; the relative toxicity of different Mn species; the potential for sensitive subpopulations including females, the young and elderly; differences in sensitivity between test species and humans; differences between inhalation and oral exposures; and the influence of dose rate and exposure duration on tissue accumulation of Mn. It was determined that development of specific sets of pharmacokinetic information and models regarding Mn could help resolve much of the uncertainties identified. Results. The results of the test program included development of several unique Mn PK datasets, and a series of increasingly sophisticated Mn physiologically-based pharmacokinetic

  7. A historical overview of the development of manganese (Mn) ...

    Science.gov (United States)

    Abstract for Manganese 2016A historical overview of the development of manganese (Mn) pharmacokinetic data under Section 211(b) of the Clean Air Act (CAA)William K BoyesBackground. In the 1990’s, the use of methylcyclopentadienyl manganese tricarbonyl (MMT) as an octane-enhancing gasoline fuel additive led to concerns for potential public health consequences from exposure to Mn combustion products in automotive exhaust. Methods: After a series of regulatory / legal actions and negotiations, the EPA issued under CAA 211(b) an Alternative Tier 2 Test Rule that required development of scientific information intended to help resolve uncertainties in exposure or health risk estimates associated with MMT use. Among the uncertainties identified were: the chemical forms of Mn emitted in automotive exhaust; the relative toxicity of different Mn species; the potential for sensitive subpopulations including females, the young and elderly; differences in sensitivity between test species and humans; differences between inhalation and oral exposures; and the influence of dose rate and exposure duration on tissue accumulation of Mn. It was determined that development of specific sets of pharmacokinetic information and models regarding Mn could help resolve much of the uncertainties identified. Results. The results of the test program included development of several unique Mn PK datasets, and a series of increasingly sophisticated Mn physiologically-based pharmacokinetic

  8. Catalytic combustion of toluene over copper-manganese catalysts supported on titanium dioxide%新型CuMn/TiO2苯类催化燃烧催化剂的研制及活性实验

    Institute of Scientific and Technical Information of China (English)

    李鹏; 童志权; 黄妍; 张俊丰

    2008-01-01

    采用浸溃法制备了CuMn/TiO2新型甲苯燃烧催化剂,其活性明显优于传统CuMn/γ-Al2O3和Cu-Mn复合氧化物催化剂.研究发现,载体TiO2自身有一定催化活性,而γ-Al2O3则几乎没有活性;TiO2与Cu-Mn之间的协同作用更提高了新型催化剂的活性.XRD、LRS结果显示,CuMn/TiO2催化剂的主要活性相为铜锰尖晶石(CuMn2O4),它的存在是CuMn/TiO2催化活性优良的另一个主要原因.考察了Cu-Mn负载量、铜锰比和焙烧温度对催化剂活性的影响,CuMn/TiO2下对甲苯的去除率达95%以上时催化床层温度为215℃,比CuMn/γ-Al2O3和Cu-Mn复合氧化物对甲苯去除率达95%时分别下降了30℃、50℃左右.

  9. Regulation of Copper Transport Crossing Brain Barrier Systems by Cu-ATPases: Effect of Manganese Exposure

    Science.gov (United States)

    Fu, Xue; Zhang, Yanshu; Jiang, Wendy; Monnot, Andrew Donald; Bates, Christopher Alexander; Zheng, Wei

    2014-01-01

    Regulation of cellular copper (Cu) homeostasis involves Cu-transporting ATPases (Cu-ATPases), i.e., ATP7A and ATP7B. The question as to how these Cu-ATPases in brain barrier systems transport Cu, i.e., toward brain parenchyma, cerebrospinal fluid (CSF), or blood, remained unanswered. This study was designed to characterize roles of Cu-ATPases in regulating Cu transport at the blood-brain barrier (BBB) and blood-CSF barrier (BCB) and to investigate how exposure to toxic manganese (Mn) altered the function of Cu-ATPases, thereby contributing to the etiology of Mn-induced parkinsonian disorder. Studies by quantitative real-time RT-PCR (qPCR), Western blot, and immunocytochemistry revealed that both Cu-ATPases expressed abundantly in BBB and BCB. Transport kinetic studies by in situ brain infusion and ventriculo-cisternal (VC) perfusion in Sprague Dawley rat suggested that the BBB was a major site for Cu entry into brain, whereas the BCB was a predominant route for Cu efflux from the CSF to blood. Confocal evidence showed that the presence of excess Cu or Mn in the choroid plexus cells led to ATP7A relocating toward the apical microvilli facing the CSF, but ATP7B toward the basolateral membrane facing blood. Mn exposure inhibited the production of both Cu-ATPases. Collectively, these data suggest that Cu is transported by the BBB from the blood to brain, which is mediated by ATP7A in brain capillary. By diffusion, Cu ions move from the interstitial fluid into the CSF, where they are taken up by the BCB. Within the choroidal epithelial cells, Cu ions are transported by ATP7B back to the blood. Mn exposure alters these processes, leading to Cu dyshomeostasis-associated neuronal injury. PMID:24614235

  10. 40 CFR 721.10013 - Manganese yttrium oxide (Mn2YO5).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Manganese yttrium oxide (Mn2YO5). 721... Substances § 721.10013 Manganese yttrium oxide (Mn2YO5). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as manganese yttrium oxide (Mn2YO5) (PMN...

  11. 40 CFR 721.10009 - Manganese yttrium oxide (MnYO3).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Manganese yttrium oxide (MnYO3). 721... Substances § 721.10009 Manganese yttrium oxide (MnYO3). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as manganese yttrium oxide (MnYO3) (PMN...

  12. 40 CFR 721.4587 - Lithium manganese oxide (LiMn204) (generic name).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Lithium manganese oxide (LiMn204... Specific Chemical Substances § 721.4587 Lithium manganese oxide (LiMn204) (generic name). (a) Chemical... as lithium manganese oxide (LiMn204) (P-96-175) is subject to reporting under this section for...

  13. 40 CFR 721.10010 - Barium manganese oxide (BaMnO3).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Barium manganese oxide (BaMnO3). 721... Substances § 721.10010 Barium manganese oxide (BaMnO3). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as barium manganese oxide (BaMnO3) (PMN...

  14. Manganese (Mn) Oxidation Increases Intracellular Mn in Pseudomonas putida GB-1

    Science.gov (United States)

    Banh, Andy; Chavez, Valarie; Doi, Julia; Nguyen, Allison; Hernandez, Sophia; Ha, Vu; Jimenez, Peter; Espinoza, Fernanda; Johnson, Hope A.

    2013-01-01

    Bacterial manganese (Mn) oxidation plays an important role in the global biogeochemical cycling of Mn and other compounds, and the diversity and prevalence of Mn oxidizers have been well established. Despite many hypotheses of why these bacteria may oxidize Mn, the physiological reasons remain elusive. Intracellular Mn levels were determined for Pseudomonas putida GB-1 grown in the presence or absence of Mn by inductively coupled plasma mass spectrometry (ICP-MS). Mn oxidizing wild type P. putida GB-1 had higher intracellular Mn than non Mn oxidizing mutants grown under the same conditions. P. putida GB-1 had a 5 fold increase in intracellular Mn compared to the non Mn oxidizing mutant P. putida GB-1-007 and a 59 fold increase in intracellular Mn compared to P. putida GB-1 ∆2665 ∆2447. The intracellular Mn is primarily associated with the less than 3 kDa fraction, suggesting it is not bound to protein. Protein oxidation levels in Mn oxidizing and non oxidizing cultures were relatively similar, yet Mn oxidation did increase survival of P. putida GB-1 when oxidatively stressed. This study is the first to link Mn oxidation to Mn homeostasis and oxidative stress protection. PMID:24147089

  15. Manganese-induced reactive oxygen species: comparison between Mn+2 and Mn+3.

    Science.gov (United States)

    Ali, S F; Duhart, H M; Newport, G D; Lipe, G W; Slikker, W

    1995-09-01

    Manganese (Mn) is an essential element, the deficiency or excess of which is known to cause neurotoxicity in experimental animals and man. The mechanism of action of Mn neurotoxicity is still unclear. The present study was designed to evaluate whether in vitro or in vivo exposure to Mn produced reactive oxygen species (ROS). We also sought to determine if a single injection of Mn produces changes in monoamines concentration in different regions of rat brain. Adult Sprague-Dawley rats were dosed with 0, 50 or 100 mg/kg, ip with either MnCl2 (Mn+2) or MnOAc (Mn+3) and were sacrificed 1 h after the dose was administered. Brains were quickly removed and dissected for neurochemical analysis. ROS were measured by a molecular probe, 2',7'-dichlorofluorescein diacetate (DCFH-DA), and monoamines and their metabolites were measured by HPLC/EC. In vitro exposure to MnCl2 (1-1000 microM) produced dose-dependent increases of ROS in striatum whereas MnOAc produced similar increases at much lower concentrations (1-100 microM). In vivo exposure to MnOAc (Mn+3) produced significant increases of ROS in caudate nucleus and hippocampus, whereas MnCl2 (Mn+2) produced significant effects only in hippocampus. Concentrations of dopamine, serotonin and their metabolites (DOPAC, HVA and 5-HIAA) were not altered with acute injections of either MnCl2 or MnOAc. These data suggest that both divalent and trivalent manganese induce ROS, however, Mn+3 is an order of magnitude more potent than Mn+2.

  16. Characterization and Activity of Cu-MnOx/γ-Al2O3 Catalyst forHydrogenation of Carbon Dioxide

    Institute of Scientific and Technical Information of China (English)

    QI, Gong-Xin; ZHENG, Xiao-Ming; FEI, Jin-Hua; HOU, Zhao-Yin

    2001-01-01

    The effect of manganese on the dispersion, reduction behaviorand active states of surface of supported copper oxide catalysts have been investigated by XRD, temperature-programmed reduction and XPS. The activity of methanol synthesis from CO2/H2 was also investigated. The catalytic activity over CuO-MnOx/γ-Al2O3 catalyst for CO2 hydrogenation is higher than that of CuO/γ-Al2O3. The adding of manganese is beneficial in enhancing the dispersion of the supported copper oxide and make the TPR peak of the CuO-MnOx/γ-Al2O3 catalyst different from the individual supported coppper and manganese oxide catalysts, which indicates that there exists strong interaction between the copper and manganese oxide. For the CuO/γ-Al2O3 catalyst there are two reducible copper oxide species; α and β peaks are attributed to the reduction of highly dispersed copper oxide species and bulk CuO species, respectively. For the CuO-MnOx/γ-Al2O3 catalyst, four reduction peaks are observed, α peak is attributed to the dispersed copper oxide species; β peak is ascribed to the bulk CuO; γ peak is attributed to the reduction of high dispersed CuO interacting with manganese; δ peak may be the reduction of the manganese oxide interacting with copper oxide. XPS results show that Cu+ mostly existed on the working surface of the Cu-Mn/γ-Al2O3 catalysts. The activity was promoted by Cu with positive charge which was formed by means of long path exchange function between Cu-O-Mn. These results indicate that there is synergistic interaction between the copper and manganese oxide, which is responsible for the high activity of CO2 hydrogenation.

  17. 40 CFR 721.10008 - Manganese strontium oxide (MnSrO3).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Manganese strontium oxide (MnSrO3... Specific Chemical Substances § 721.10008 Manganese strontium oxide (MnSrO3). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as manganese strontium...

  18. Hydrothermal synthesis of silico-manganese nanohybrid for Cu(II) adsorption from aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Qiufeng, E-mail: zhuqiufeng@th.btbu.edu.cn; Wang, Liting; An, Zehuan; Ye, Hong; Feng, Xudong

    2016-05-15

    Highlights: • A novel silico-manganese nanohybrid adsorbent (SMNA) was synthesized by a hydrothermal method. • The adsorption capacities of the SMNA for Cu(II) are lower pH dependency. • As-adsorbents are very efficient at low metal concentration and substantial amounts of Cu(II) can be removed from aqueous solution. - Abstract: A novel silico-manganese nanohybrid adsorbent (SMNA) was synthesized by a facile hydrothermal method, and characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), nitrogen adsorption-desorption, Fourier transform infrared spectroscopy (FT-IR) and zeta potential measurement. The adsorption of Cu(II) ions from aqueous solution on the SMNA was investigated with variations in contact time, pH and initial Cu(II) concentration. The results showed that hydrothermal method would generate nanowire/nanorod incomplete crystallite (δ-MnO{sub 2}) adsorbent. The adsorption of Cu(II) onto SMNA increased sharply within 25 min and reached equilibrium gradually. The maximum adsorption capacities of SMNA for Cu(II) were ∼40–88 mg g{sup −1}, which was lower than δ-MnO{sub 2} (92.42 mg g{sup −1}) but had a lower pH dependency. As compared with δ-MnO{sub 2}, higher adsorption capacities of SMNA (7.5–15 wt% of silica doping amount) for Cu(II) could be observed when pH of the aqueous solution was low (<4). The pseudo-second-order model was the best choice to describe the adsorption behavior of Cu(II) onto SMNA, suggesting that the removal of Cu(II) by the as-prepared adsorbents was dominated by migration of Cu(II). The possibility of Cu(II) recovery was also investigated and it revealed that SMNA was a promising recyclable adsorbent for removal of heavy metal ions in water and wastewater treatment.

  19. Differential regulation of genes encoding manganese peroxidase (MnP) in the basidiomycete Ceriporiopsis subvermispora.

    Science.gov (United States)

    Manubens, Augusto; Avila, Marcela; Canessa, Paulo; Vicuña, Rafael

    2003-09-01

    We previously identified and characterized three mnp genes coding for manganese peroxidase (MnP) in the white rot fungus Ceriporiopsis subvermispora. In this work, we assessed transcript levels of mnp genes in liquid cultures of this fungus grown under various conditions. In the absence of Mn(2+), mnp1 and mnp2 mRNA were detected by Northern hybridization, irrespective of the lack of extracellular MnP activity. Addition of Mn(2+) to the cultures led to a marked increase in both transcripts, the highest titers being observed at 10 micro M Mn(2+). mnp1 mRNA was not detected at Mn(2+ )concentrations above 80 micro M, whereas mnp2 mRNA was still observed at 320 micro M Mn(2+). Differential regulation of these genes was confirmed by the addition of Cu(2+), Zn(2+), Ag(+) and Cd(2+). These metal ions dramatically elevated both transcripts and also allowed the detection of the mnp3 transcript. In most cases, the increase in mRNA levels was partially abolished by the simultaneous presence of Mn(2+), although the latter was strictly required to detect extracellular MnP activity. However, the lignin-related compound syringic acid specifically increased the mnp1 transcript, although only in the absence of Mn(2+). These results indicate that there is no clear correlation between mnp mRNA levels and MnP activity. In addition, they strongly suggest that Mn(2+) plays a post-transcriptional role which is essential for the presence of active MnP in the extracellular fluid.

  20. Hydrothermal synthesis of silico-manganese nanohybrid for Cu(II) adsorption from aqueous solution

    Science.gov (United States)

    Zhu, Qiufeng; Wang, Liting; An, Zehuan; Ye, Hong; Feng, Xudong

    2016-05-01

    A novel silico-manganese nanohybrid adsorbent (SMNA) was synthesized by a facile hydrothermal method, and characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), nitrogen adsorption-desorption, Fourier transform infrared spectroscopy (FT-IR) and zeta potential measurement. The adsorption of Cu(II) ions from aqueous solution on the SMNA was investigated with variations in contact time, pH and initial Cu(II) concentration. The results showed that hydrothermal method would generate nanowire/nanorod incomplete crystallite (δ-MnO2) adsorbent. The adsorption of Cu(II) onto SMNA increased sharply within 25 min and reached equilibrium gradually. The maximum adsorption capacities of SMNA for Cu(II) were ∼40-88 mg g-1, which was lower than δ-MnO2 (92.42 mg g-1) but had a lower pH dependency. As compared with δ-MnO2, higher adsorption capacities of SMNA (7.5-15 wt% of silica doping amount) for Cu(II) could be observed when pH of the aqueous solution was low (removal of Cu(II) by the as-prepared adsorbents was dominated by migration of Cu(II). The possibility of Cu(II) recovery was also investigated and it revealed that SMNA was a promising recyclable adsorbent for removal of heavy metal ions in water and wastewater treatment.

  1. Effect of Cu on Microstructures of Manganese Steel by EDXA and SEM

    Institute of Scientific and Technical Information of China (English)

    Xinhua CHEN; Junhua DONG; Enhou HAN; Wei KE

    2007-01-01

    In order to investigate the distribution of Cu and Mg, and the effect of Cu on the microstructure of steels,manganese steels containing various Cu contents were annealed at 1260, 1100 and 1000℃, respectively, for 1 h and subsequently cooled to room temperature in the furnace to simulate the pre-rolling anneal. The results indicate that Cu is not microscopically segregated in the annealed steels. The scanning electron microscopy (SEM) observation shows that the main microstructure consist of ferrite and pearlite; the percentage of pearlite in the steels increases with increasing Cu content. The grain size reduces with the decrease of the annealing temperature. The results of energy dispersive X-ray analysis (EDXA) suggest that Cu content in pearlite is higher than that in ferrite, demonstrating that the microstructure-segregation of Cu occurred. However, the cast specimens show that Cu content in MnS and S-rich phases is high. In addition, Cu of 0.2%-0.4% could improve the distribution of MnS and S-rich inclusions. The optimal Cu content in steels and the optimal annealing temperature between 1100-1200 ℃ were determined.

  2. STUDY OF MnOx-PROMOTED Cu/γ-Al203 CATALYSTS FOR HYDROGENATION OF CARBON MONOXIDE

    Institute of Scientific and Technical Information of China (English)

    Qi Gongxin; Fei Jinhua; Hou Zhaoyin; Zheng Xiaoming

    2001-01-01

    γ-Alumina-supported copper-manganese oxide was prepared by impregnation and used for carbon monoxide hydrogenation. The Cu-MnOx/γ-Al2O3 catalysts exhibit high catalytic activity in CO hydrogenation, showing markedly enhanced catalytic activities due to the synergistic interaction between the copper and manganese oxide. The results of XRD indicated that the addition of manganese enhances the dispersion of CuO, retards the reduction of CuO and enhances the ability of H2-adsorption, which contribute to the activity of DME synthesis from syngas.

  3. Paduan Ni-Cu-Mn Sebagai Logam Alternatif Kedokteran Gigi: Efek Perendaman dalam Larutan 0,1% Sodium Sulfida

    Directory of Open Access Journals (Sweden)

    Bambang Irawan

    2015-09-01

    Full Text Available In this study, the ternary base alloys of nickel-copper-manganese (Ni-Cu-Mn alloys are prepared and these ternary alloys systems, which were constituted from higher nickel and lower copper contents than copper-base alloy ones, were evaluated by a tarnish test. Tarnish tests conducted in a 0,1% sodium sulphide solution (pH=12 at 37◦C. All test specimens were case into square paddles of 15 mm x 20 mm x 2,5 mm using the lost-wax technique with a phosphate-bonded investment. The surface of the specimens were then prepared with abrasion papers down to a 600 grit finish. Tarnish attack was quantitatively evaluated by Fibre colorimetry. The results of tarnish test showed that ternary nickel-copper-manganese alloys, such as 40Ni-30Cu-30Mn and 50Ni-30Cu-20Mn, have superior tarnishment resistance than other alloys, e.g. 20Ni-40Cu-40Mn, 30Ni-30Cu-40Mn and 30Ni-40Cu-30Mn. It was also found that 40Ni-30Cu-30Mn and 50Ni-30Cu-20Mn alloys have lower values of colour change vector than the other alloys given above.

  4. Thermodynamic Properties of Carbon and Manganese in Mn-C and Mn-Fe-C Melts

    Institute of Scientific and Technical Information of China (English)

    CHEN Er-bao; WANG Shi-jun

    2008-01-01

    Carbon solubility in Mn-Fe melts (xMn=0.083-0.706,xFe=0.034-0.715) was measured experimentally at various temperatures.By thermodynamic derivation and calculation,the relationship between activity coefficient of carbon in infinite dilute solution of manganese in Mn-C system and temperature was obtained.Using Gibbs-Duhem relationship,the experimental results of this study,and experimental data obtained by strict thermodynamic derivation and calculation in references,the relationships between other thermodynamic properties (εCC,εCCC,εCFe,eεCCFe,and εCFeCFe) in Mn-Fe-C system and temperature were obtained.

  5. Synthesis, structure, magnetic, electrical and electrochemical properties of Al, Cu and Mg doped MnO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Hashem, Ahmed M., E-mail: ahmedh242@yahoo.com [National Research Centre, Inorganic Chemistry Department, Behoes St., Dokki, Cairo (Egypt); Institute for Complex Materials, IFW Dresden, Helmholtzstr. 20, D-01069 Dresden (Germany); Abuzeid, Hanaa M. [National Research Centre, Inorganic Chemistry Department, Behoes St., Dokki, Cairo (Egypt); Narayanan, N. [Institute for Complex Materials, IFW Dresden, Helmholtzstr. 20, D-01069 Dresden (Germany); Ehrenberg, Helmut [Institute for Complex Materials, IFW Dresden, Helmholtzstr. 20, D-01069 Dresden (Germany); Materials Science, Technische Universitaet Darmstadt, Petersenstr. 23, D-64287 Darmstadt (Germany); Julien, C.M. [Universite Pierre et Marie Curie, Physicochimie des Electrolytes, Colloides et Sciences Analytiques (PECSA), 4 place Jussieu, 75005 Paris (France)

    2011-10-17

    Highlights: {yields} Al, Mg and Cu doped MnO{sub 2} as cathode in Li-ion batteries. {yields} Pure phase MnO{sub 2} for virgin and doped MnO{sub 2} were obtained. {yields} Doping elements improve the electrical conductivity of MnO{sub 2}. {yields} Electrochemical behaviour of MnO{sub 2} improved after doping by Al, Mg and Cu. - Abstract: Pure and doped manganese dioxides were prepared by wet-chemical method using fumaric acid and potassium permanganate as raw materials. X-ray diffraction patterns show that pure and Al, Cu and Mg doped manganese dioxides (d-MnO{sub 2}) crystallized in the cryptomelane-MnO{sub 2} structure. Thermal analysis show that, with the assistance of potassium ions inside the 2 x 2 tunnel, the presence of Al, Cu and Mg doping elements increases the thermal stability of d-MnO{sub 2}. The electrical conductivity of d-MnO{sub 2} increases in comparison with pure MnO{sub 2}, while Al-doped MnO{sub 2} exhibits the lower resistivity. As shown in the magnetic measurements, the value of the experimental effective magnetic moment of Mn ions decreases with introduction of dopants, which is attributed to the presence of a mixed valency of high-spin state Mn{sup 4+}/Mn{sup 3+}. Doped MnO{sub 2} materials show good capacity retention in comparison with virgin MnO{sub 2}. Al-doped MnO{sub 2} shows the best electrochemical results in terms of capacity retention and recharge efficiency.

  6. Synthesis and magnetic properties of hexagonal Y(Mn,Cu)O{sub 3} multiferroic materials

    Energy Technology Data Exchange (ETDEWEB)

    Jeuvrey, L., E-mail: laurent.jeuvrey@univ-rennes1.fr [Sciences Chimiques de Rennes, UMR-CNRS 6226, Universite de Rennes 1, 35042 Rennes cedex (France); Pena, O. [Sciences Chimiques de Rennes, UMR-CNRS 6226, Universite de Rennes 1, 35042 Rennes cedex (France); Moure, A.; Moure, C. [Electroceramics Department, Instituto de Ceramica y Vidrio, CSIC, C/Kelsen 5, 28049, Madrid (Spain)

    2012-03-15

    Single-phase hexagonal-type solid solutions based on the multiferroic YMnO{sub 3} material were synthesized by a modified Pechini process. Copper doping at the B-site (YMn{sub 1-x}Cu{sub x}O{sub 3}; x<0.15) and self-doping at the A-site (Y{sub 1+y}MnO{sub 3}; y<0.10) successfully maintained the hexagonal structure. Self-doping was limited to y(Y)=2 at% and confirmed that excess yttrium avoids formation of ferromagnetic manganese oxide impurities but creates vacancies at the Mn site. Chemical substitution at the B-site inhibits the geometrical frustration of the Mn{sup 3+} two-dimensional lattice. The magnetic transition at T{sub N} decreases from 70 K down to 49 K, when x(Cu) goes from 0 to 15 at%. Weak ferromagnetic Mn{sup 3+}-Mn{sup 4+} interactions created by the substitution of Mn{sup 3+} by Cu{sup 2+}, are visible through the coercive field and spontaneous magnetization but do not modify the overall magnetic frustration. Presence of Mn{sup 3+}-Mn{sup 4+} pairs leads to an increase of the electrical conductivity due to thermally-activated small-polaron hopping mechanisms. Results show that local ferromagnetic interactions can coexist within the frustrated state in the hexagonal polar structure. - Highlights: Black-Right-Pointing-Pointer Hexagonal-type solid solutions of Y(Mn,Cu)O{sub 3} synthesized by Pechini process. Black-Right-Pointing-Pointer Chemical substitution at B site inhibits geometrical magnetic frustration. Black-Right-Pointing-Pointer Magnetic transition decreases with Cu-doping. Black-Right-Pointing-Pointer Local ferromagnetic Mn-Mn interactions coexist with the frustrated state.

  7. Ferromagnetism of Fe{sub 86}Mn{sub 14-y}Cu{sub y} alloys

    Energy Technology Data Exchange (ETDEWEB)

    Franca, F. [DF-UDESC, Joinville, CEP 89223-100, SC (Brazil); Paduani, C. [DF-UFSC, Florianopolis, CEP 88040-900, SC (Brazil)]. E-mail: paduani@fisica.ufsc.br; Krause, J.C. [DCET-URI, Santo Angelo, CEP 98802-470, RS (Brazil); Ardisson, J.D. [CDTN, Belo Horizonte, CEP 30123-970, MG (Brazil); Yoshida, M.I. [DQ-ICEX-UFMG, Belo Horizonte, CEP 31270-901, MG (Brazil); Schaf, J. [IF-UFRGS, Porto Alegre, CEP 91501-970, RS (Brazil)

    2007-01-01

    The magnetic properties of disordered Fe{sub 86}Mn{sub 14-y}Cu{sub y} alloys were investigated with several experimental techniques. The results of X-ray diffraction showed that these alloys are single phase with the A2 (BCC) structure. These are ferromagnetic alloys at room temperature, and the Curie temperature decreases with the increase of the Cu content. An abrupt loss of magnetization was observed below T{sub C} at a temperature which increases with the reduction of the Mn content in the alloys. The addition of manganese enhances the solubility of copper in iron matrix and retains the BCC structure in iron-rich alloys. The behavior of the magnetization with temperature and its composition dependence indicate that an antiferromagnetic coupling is expected between the Fe and Mn atoms. The magnetic moments of both Fe and Mn atoms are expected to vary strongly with composition in these alloys.

  8. Effect of the loading content of CuO on the activity and structure of CuO/Ce-Mn-O catalysts for CO oxidation

    Institute of Scientific and Technical Information of China (English)

    赵福真; 龚渺; 张广营; 李金林

    2015-01-01

    A urea-nitrate combustion method was used to prepare Ce-Mn-O material, which was applied as the support for a series of CuO/Ce-Mn-O catalysts. The structure of the catalysts was characterized with N2 adsorption/desorption, X-ray diffraction (XRD), temperature-programmed reduction (TPR) and X-ray photoelectron spectroscopy (XPS). The catalytic activity of the catalysts for the oxidation of CO was evaluated on a conventional fixed-bed quartz reactor. XRD results showed that the synergetic effect between manganese and cerium led to a little higher electron density of Ce3+ in the mixed oxides. When the CuO content was lower than 5 wt.%, Cu species were well dispersed onto the Ce-Mn-O support or/and they formed a solid solution with CeO2 (inside the fluorite lattice). At higher CuO content (CuO>5 wt.%), large CuO particles were observed. There was strong interaction among ceria, man-ganese and copper oxide because of the doping of Mn. This interplay changed the reducibility and the valence states of the compo-nents, leading to the improved activity of the CuO/Ce-Mn-O catalysts.

  9. Acclimation of a marine microbial consortium for efficient Mn(II) oxidation and manganese containing particle production

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Hao, E-mail: zhouhao@dlut.edu.cn [Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Food and Environment, Dalian University of Technology, Panjin 124221 (China); Pan, Haixia [Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Food and Environment, Dalian University of Technology, Panjin 124221 (China); Xu, Jianqiang [School of Life Science and Medicine, Dalian University of Technology, Panjin 124221 (China); Xu, Weiping; Liu, Lifen [Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Food and Environment, Dalian University of Technology, Panjin 124221 (China)

    2016-03-05

    Highlights: • An efficient Mn(II) oxidation marine sediments microbial community was obtained. • High-throughput sequencing indicated new Mn(II) oxidation associated genus. • Na{sub 3}MnPO{sub 4}CO{sub 3} and MnCO{sub 3} were synthesized by the consortium. • Consortium exhibited Mn(II) oxidation performance over a range of harsh conditions. - Abstract: Sediment contamination with metals is a widespread concern in the marine environment. Manganese oxidizing bacteria (MOB) are extensively distributed in various environments, but a marine microbial community containing MOB is rarely reported. In this study, a consortium of marine metal-contaminated sediments was acclimated using Mn(II). The shift in community structure was determined through high-throughput sequencing. In addition, the consortium resisted several harsh conditions, such as toxic metals (1 mM Cu(II) and Fe(III)), and exhibited high Mn(II) oxidation capacities even the Mn(II) concentration was up to 5 mM. Meanwhile, biogenic Mn containing particles were characterized by scanning electron microscope (SEM), X-ray powder diffraction (XRD), and N{sub 2} adsorption/desorption. Dye removal performance of the Mn containing particles was assayed using methylene blue, and 20.8 mg g{sup −1} adsorption capacity was obtained. Overall, this study revealed several new genera associated with Mn(II) oxidation and rare biogenic Na{sub 3}MnPO{sub 4}CO{sub 3.} Results suggested the complexity of natural microbe-mediated Mn transformation.

  10. Magnetic interactions in Cu-substituted manganese ferrites

    Science.gov (United States)

    Rana, Mazhar U.; Misbah-ul-Islam; Abbas, Tahir

    2003-04-01

    A series of Mn 1- xCu xFe 2O 4, with x=0, 0.25, 0.50, 0.75 and 1.0, spinel ferrites were prepared by standard ceramic method, to study the effect of compositional variation on magnetic susceptibility, saturation magnetization ( Ms), Curie temperature ( Tc) and magnetic moments ( μB). The Curie temperatures have been evaluated by measuring the ac susceptibility using the mutual inductance technique. On increasing Cu contents from 0.0 to 0.50, the saturation magnetization increases while the Curie temperature decreases. On further increase in Cu contents, x>0.50 a decreasing trend in Ms is exhibited while Tc continues to decrease. This effect can be partially related to the low magnetic moments of Cu +2 ions. The dominant interaction in all ferrite samples is A-B interaction which is due to the negative values of the characteristic temperature θ(K) showing that the magnetic ordering is antiferromagnetic. The Y-K angle increases gradually with increasing copper contents and extrapolates to 90° for CuFe 2O 4. From the computation of Y-K angles for Mn 1- xCu xFe 2O 4, it can be concluded that the mixed copper ferrites exhibit a non-collinearity of the Y-K type while MnFe 2O 4 shows a Neel type of ordering.

  11. Effects of carrier and Mn loading on supported manganese oxide catalysts for catalytic combustion of methane

    Institute of Scientific and Technical Information of China (English)

    Jinyan Hu; Wei Chu; Limin Shi

    2008-01-01

    Supported manganese oxide catalysts were prepared by incipient wetness impregnation method for methane cat-alytic combustion, and effects of the support (Al2O3, SiO2 and TiO2) and Mn loading were investigated. These catalysts were characterized with N2 adsorption, X-ray diffraction, X-ray photoelectron spectroscopy and temperature-programmed reduction techniques. Methane conversion varied in a large range depending on supports or Mn loading. Al2O3 supported 15% Mn cata-lyst exhibited better activity toward methane catalytic oxidation. The manganese state and oxygen species played an important role in the catalytic performance.

  12. Catalytic behavior and synergistic effect of nanostructured mesoporous CuO-MnOx-CeO2 catalysts for chlorobenzene destruction

    Science.gov (United States)

    He, Chi; Yu, Yanke; Shen, Qun; Chen, Jinsheng; Qiao, Nanli

    2014-04-01

    Mesoporous CuO-MnOx-CeO2 composite metal oxides with different copper and manganese loadings were prepared by a urea-assistant hydrothermal method, and were further adopted for the complete catalytic combustion of chlorobenzene. The effects of reaction conditions such as inlet reagent concentration and water feed concentration on chlorobenzene combustion were also studied. The structure and textural properties of the synthesized catalysts were characterized via the XRD, N2 adsorption/desorption, FE-SEM, TEM, H2-TPR, O2-TPD, and XPS techniques. The characterization results reveal that the presence of a small amount of Mn species can facilitate the incorporation of Cu and Mn ions into ceria lattice to form Cu-Mn-Ce-O solid solution. The synergistic effect of Cu and Mn species can reduce the redox potential of the composite catalysts, and produce large amounts of oxygen vacancies in the interface of CuOx, MnOx, and CeO2 oxides. The catalyst with Cu/Mn atomic ratio of 1/1 exhibits the best chlorobenzene elimination capability, oxidizing about 95% of the inlet chlorobenzene at 264 °C with CO2 selectivity higher than 99.5%. The concentration and mobility of the chemically adsorbed oxygen are vital for the effective removal of surface Cl species, which inhibits the dissociation of oxygen molecules and decreases the reducibility of the copper and manganese species. It can be rationally concluded that the superior catalytic performance and durability of the mesoporous CuO-MnOx-CeO2 composite oxides are primarily attributed to the higher surface oxygen concentration and better active oxygen mobility.

  13. Sorption behaviour of manganese-coated calcined-starfish and manganese-coated sand for Mn(II).

    Science.gov (United States)

    Lee, Seung-Mok; Kim, Won-Gee; Yang, Jae-Kyu; Tiwari, Diwakar

    2010-04-01

    The objective of the present investigation was to explore the sorption behaviour of manganese-coated samples of calcined starfish (MCCSF) (i.e. the impregnation of calcined starfish with manganese) for the removal of low levels of an important heavy metal toxic ion, Mn(II), from aqueous solutions. The suitability of this solid was further compared with two different samples of manganese-coated sands (MCS): MCS4 and MCS9 impregnated at pH 4.0 and pH 9.0, respectively. These comparative studies were performed in both batch and column experiments. Batch data indicated that a fairly good stability of the coating was obtained for these three samples in the pH region 2.5 to 10.0. The removal efficiency of MCCSF was fairly good in comparison with the MCS4 and MCS9 samples. These last two samples possessed similar Mn(II) removal capacities. Moreover, a small dose of sodium hypochlorite further enhanced the uptake of Mn(II) by these solids. The sorbate concentration dependence data fitted reasonably well to the Freundlich adsorption isotherm. The column data indicated that MCCSF possessed a relatively higher adsorption capacity compared with the MCS4 and MCS9 samples. The breakthrough curves obtained were then used to evaluate the apparent removal capacity of these solids under the dynamic conditions using the Thomas equation. The SEM images obtained for these manganese-coated solids along with the virgin base materials, i.e. sand and calcined starfish, showed that manganese oxides occupied the surfaces or pores of the base materials and formed clusters on the base surface.

  14. Understanding the Development and Stabilization of Mn(III) Intermediates during Microbial Manganese Reduction

    Science.gov (United States)

    Johnson, J. E.; Savalia, P.; Kocar, B. D.; Webb, S. M.; Nealson, K. H.; Fischer, W. W.

    2014-12-01

    The dominant products of Mn(II) oxidation are manganese(IV)-oxide phases, which act as important environmental oxidants and sorbents in soils, freshwater, and marine sediments. Mn(IV) oxides also provide favorable electron acceptors for metal-reducing microbes, but the intermediates and final products formed are highly dependent on environmental conditions, and challenging to predict thermodynamically. We engineered a flow-through reactor system to study the Mn phases during microbial Mn(IV) reduction by Shewanella oneidensis MR-1 in real time, using synchrotron X-ray absorption spectroscopy (XAS) to monitor redox and mineralogical changes. These 10-20 hour experiments capture Mn XAS spectra every 20 minutes and thus we can observe both transient phases and stable products under different experimental conditions. We also record the pH, collect solution and filtered solid samples throughout the experiments for later solute measurements, and confirm mineral identifications with synchrotron x-ray diffraction measurements. With excess organic carbon and high (mM) phosphate (like in a soil), Mn(IV) oxides are reduced to Mn(II) and immediately form Mn(II) phosphate in a clearly binary system. This experiment demonstrates that while there may be two successive single-electron transfer reactions from outer membrane cytochromes (Lin et al, 2012), the microbial reduction of Mn(IV) oxides is effectively a two-electron process. However, with minimal phosphate, a transient Mn(III) oxyhydroxide forms before all manganese is reduced to Mn(II) in solution and precipitates a final Mn(II)-carbonate product. We propose this Mn(III) intermediate phase forms due to reaction of Mn2+ in solution with Mn(IV)-oxide surfaces to form Mn(III)OOH, similar to experimental results from this abiotic comproportionation reaction (Elzinga, 2011). Recently, we stabilized this Mn(III) intermediate by limiting the organic carbon available to S. oneidensis, producing Mn(III)OOH and Mn(II) phases

  15. Mn-euvering manganese: the role of transporter gene family members in manganese uptake and mobilization in plants

    Science.gov (United States)

    Socha, Amanda L.; Guerinot, Mary Lou

    2014-01-01

    Manganese (Mn), an essential trace element, is important for plant health. In plants, Mn serves as a cofactor in essential processes such as photosynthesis, lipid biosynthesis and oxidative stress. Mn deficient plants exhibit decreased growth and yield and are more susceptible to pathogens and damage at freezing temperatures. Mn deficiency is most prominent on alkaline soils with approximately one third of the world's soils being too alkaline for optimal crop production. Despite the importance of Mn in plant development, relatively little is known about how it traffics between plant tissues and into and out of organelles. Several gene transporter families have been implicated in Mn transport in plants. These transporter families include NRAMP (natural resistance associated macrophage protein), YSL (yellow stripe-like), ZIP (zinc regulated transporter/iron-regulated transporter [ZRT/IRT1]-related protein), CAX (cation exchanger), CCX (calcium cation exchangers), CDF/MTP (cation diffusion facilitator/metal tolerance protein), P-type ATPases and VIT (vacuolar iron transporter). A combination of techniques including mutant analysis and Synchrotron X-ray Fluorescence Spectroscopy can assist in identifying essential transporters of Mn. Such knowledge would vastly improve our understanding of plant Mn homeostasis. PMID:24744764

  16. Mn-euvering manganese: the role of transporter gene family members in manganese uptake and mobilization in plants

    Directory of Open Access Journals (Sweden)

    Amanda Lee Socha

    2014-04-01

    Full Text Available Manganese (Mn, an essential trace element, is important for plant health. In plants, Mn serves as a cofactor in essential processes such as photosynthesis, lipid biosynthesis and oxidative stress. Mn-deficient plants exhibit decreased growth and yield and are more susceptible to pathogens and damage at freezing temperatures. Mn deficiency is most prominent on alkaline soils with approximately one third of the world’s soils being too alkaline for optimal crop production. Despite the importance of Mn in plant development, relatively little is known about how it traffics between plant tissues and into and out of organelles. Several gene transporter families have been implicated in Mn transport in plants. These transporter families include NRAMP (natural resistance associated macrophage protein, YSL (yellow stripe-like, ZIP (zinc regulated transporter/iron-regulated transporter [ZRT/IRT1]-related protein, CAX (cation exchanger, CCX (calcium cation exchangers, CDF/MTP (cation diffusion facilitator/metal tolerance protein, P-type ATPases and VIT (vacuolar iron transporter. A combination of techniques including mutant analysis and Synchrotron X-ray Fluorescence Spectroscopy can assist in identifying essential transporters of Mn. Such knowledge would vastly improve our understanding of plant Mn homeostasis.

  17. Immunoreactive Cu-SOD and Mn-SOD in lymphocytes sub-populations from normal and trisomy 21 subjects according to age

    Energy Technology Data Exchange (ETDEWEB)

    Baeteman, M.A. (Centre de Genetique Medicale and INSERM U. 242, France); Baret, A.; Courtiere, A.; Rebuffel, P.; Mattei, J.F.

    1983-02-21

    Copper and manganese superoxide dismutases (Cu-SOD and Mn-SOD) were measured by radioimmunoassay in B and T lymphocytes and macrophages, in patients with trisomy 21 and in matched controls. In the controls, Cu-SOD was present in greater amounts than Mn-SOD and there were quantitative differences in the distribution in the three cellular sub-populations. In trisomy 21, levels of Cu-SOD were raised, with no change in levels of Mn-SOD, supporting the theory of a gene dosage effect. There were significant positive and negative correlations between age and Cu-SOD levels in controls, and a correlation approaching significance for Mn-SOD. In trisomy 21, there was no correlation between age and Cu-SOD levels, and the only significant correlation for Mn-SOD was for B lymphocytes.

  18. Rational serendipity: "undirected" synthesis of a large {MnCu} complex from pre-formed Mn(II) building blocks.

    Science.gov (United States)

    Frost, Jamie M; Kettles, Fraser J; Wilson, Claire; Murrie, Mark

    2016-11-15

    Use of an aminopolyalcohol-based Mn(II) complex in solvothermal Cu(II) chemistry leads to a rare example of a high nuclearity heterometallic {MnCu} system, in which four Cu(II)(H1Edte) units trap an inner {MnCu(II)} oxide core.

  19. Thermally stable and hydrogen peroxide tolerant manganese peroxidase (MnP) from Lenzites betulinus.

    Science.gov (United States)

    Hoshino, Fumihiko; Kajino, Tsutomu; Sugiyama, Hidehiko; Asami, Osamu; Takahashi, Haruo

    2002-10-23

    A thermally stable and hydrogen peroxide tolerant manganese peroxidase (MnP) was purified from the culture medium of Lenzites betulinus by ion exchange chromatography, gel filtration and isoelectric focusing chromatography. The MnP purified from L. betulinus (L-MnP) has a molecular mass of 40 kDa and its isoelectric point was determined to be 6.2. The first 19 amino acids at the N-terminal end of the L-MnP sequence were found to exhibit 74% identity with those of a Phlebia radiata MnP. L-MnP was proved to have the highest hydrogen peroxide tolerance among MnPs reported so far. It retained more than 60% of the initial activity after thermal treatment at 60 degrees C for 60 min, and also retained more than 60% of the initial activity after exposure to 10 mM hydrogen peroxide for 5 min at 37 degrees C.

  20. EFFECT OF Cu AND Mn TOXICITY ON CHLOROPHYLL FLUORESCENCE AND GAS EXCHANGE IN RICE AND SUNFLOWER UNDER DIFFERENT LIGHT INTENSITIES

    Directory of Open Access Journals (Sweden)

    Hajiboland R.

    2007-06-01

    Full Text Available Copper (Cu and manganese (Mn are essential micronutrients for plants, but toxic at high concentrations. Responses of rice (Oryza sativa L. and sunflower (Helianthus annuus L. to toxic concentrations of Mn and Cu (up to 100 μM were studied under three light intensities including low (LL, PPFD=100, intermediate (IL, PPFD=500 and high (HL, PPFD=800 light intensities in hydroponic medium. Rice plants showed higher susceptibility than sunflower to both heavy metals concerning dry matter of shoot and root. Growing under higher light intensity strengthened the effect of Cu toxicity while ameliorated that of Mn, the latter was attributed to the lower Mn accumulation of HL plants in both shoot and root. Chlorophyll content of leaves was influenced negatively only by Cu treatment and that at the highest concentration in the medium (100 μM. Similar with growth results, reduction of net assimilation rate (A was higher in HL than LL plants treated by excess Cu, but in contrast to growth response, reduction was more prominent in sunflower than rice. Excess Mn-induced reduction of A was similar between LL and HL plants and was greater in sunflower than rice. Reduction of A was partly attributable to stomatal limitation, but non-stomatal mechanisms were also involved in this reduction. Copper and Mn treatment did not change the optimal quantum efficiency of PSII in dark-adapted chloroplasts (Fv/Fm ratio, but Fv/F0 was influenced particularly by Cu treatment, the reduction was higher in rice than sunflower and in HL compared to LL plants. Regarding excess Cu and Mn-mediated alterations in chlorophyll concentration, Fv/F0 and Tm values, it was suggested that, Cu and Mn toxicity depress the leaf photosynthetic capacity primarily by causing a significant alteration of the composition and functional competence of the photosynthetic units rather a reduction in the number of photosynthetic units (PSUs per unit leaf area.

  1. Effect of Cu-doping on optical, electrical and magnetic properties of chemically synthesized MnS nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Veeramanikandasamy, T., E-mail: veeramaniks@gmail.com [Department of Electronics and Communication Systems, Sri Krishna Arts and Science College, Coimbatore 641 008 (India); Rajendran, K. [Department of Electronics, L.R.G Govt. Arts College for Women, Tirupur 641 604 (India); Sambath, K. [Department of Electronics and Communication Systems, Sri Krishna Arts and Science College, Coimbatore 641 008 (India); Rameshbabu, P. [Center for Crystal Growth, VIT University, Vellore 632 014 (India)

    2016-03-01

    Manganese sulfide and Cu-doped manganese sulfide nanocrystals have been synthesized by wet chemical technique. The structural, optical, electrical and magnetic properties of as-synthesized nanocrystals have been investigated. The average crystallite size and lattice strain of the samples have been calculated from powder X-ray diffraction patterns using the Williamson–Hall analysis. The results show that the average crystallite size decreased while both the lattice strain and the dislocation density values increased in the Cu-doped MnS nanocrystals. The surface morphology of Cu-doped MnS nanocrystals has lesser particle size than undoped sample and it shows spherical like structures with little agglomeration. The chemical composition of the prepared samples has been obtained from EDAX. It clearly indicates the presence of Cu ions in the MnS lattice. UV–visible spectroscopy shows a blue shift in the optical band gap with doping. The photoluminescence spectra on the doped sample show a quenching of the PL intensity due to strain induced by doping. The electrical conduction, dielectric and impedance properties of as-synthesized nanocrystals have been investigated in the frequency range 50 Hz–5 MHz and temperature range 323–473 K which are greatly affected by doping with Cu. The vibrating sample magnetometer measurement revealed that the undoped MnS has paramagnetic behavior while the Cu-doped MnS has superparamagnetic behavior. On Cu-doping, the saturation magnetization and remanence increases while the coercivity decreases. - Highlights: • Pure and Cu-doped MnS nanocrystals were synthesized by the wet chemical technique. • Optical band gap value is raised by the Burstein-Moss effect due to the introduction of Cu-dopant. • It is a potential material for violet-blue light emission. • Cu-doped MnS showed good electrical conductivity compared to pure γ-MnS. • Doping of Cu induces superparamagnetic behavior in the system.

  2. Mn-SOD and CuZn-SOD polymorphisms and interactions with risk factors in gastric cancer

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    AIM: To investigate the effects of superoxide dismutase (SOD) polymorphisms (rs4998557 , rs4880), Helicobacter pylori (H. pylori ) infection and environmental factors in gastric cancer (GC) and malignant potential of gastric precancerous lesions (GPL). METHODS: Copper-zinc superoxide dismutase (SOD1, CuZn-SOD)-G7958A (rs4998557 ) and manganese superoxide dismutase (SOD2, Mn-SOD)-Val16Ala (rs4880 ) polymorphisms were genotyped by SNaPshot multiplex polymerase chain reaction (PCR) in 145 patients with GPL (87...

  3. Manganese in the shell of the bivalve Mytilus edulis: Seawater Mn or physiological control?

    Science.gov (United States)

    Freitas, Pedro S.; Clarke, Leon J.; Kennedy, Hilary; Richardson, Christopher A.

    2016-12-01

    Manganese in the shell calcite of marine bivalves has been suggested to reflect ambient seawater Mn concentrations, thus providing a high-resolution archive of past seawater Mn concentrations. However, a quantitative relationship between seawater Mn and shell Mn/Ca ratios, as well as clear understanding of which process(es) control(s) shell Mn/Ca, are still lacking. Blue mussels, Mytilus edulis, were grown in a one-year duration field experiment in the Menai Strait, U.K., to study the relationship between seawater particulate and dissolved Mn2+ concentrations and shell calcite Mn/Ca ratios. Shell Mn/Ca showed a well-defined intra-annual double-peak, with maximum values during early spring and early summer and low values during autumn and winter. Seawater particulate Mn peaked during winter and autumn, with a series of smaller peaks during spring and summer, whereas dissolved Mn2+ exhibited a marked single maximum during late-spring to early-summer, being low during the remainder of the year. Consequently, neither seawater particulate Mn nor dissolved Mn2+ concentrations explain the intra-annual variation of shell Mn/Ca ratios. A physiological control on shell Mn/Ca ratios is evident from the strong similarity and timing of the double-peaked intra-annual variations of Mn/Ca and shell growth rate (SGR), the latter corresponding to periods of increased metabolic activity (as indicated by respiration rate). It is thus likely that in M. edulis SGR influences shell Mn/Ca by altering the concentration or activity of Mn2+ within the extra-pallial fluid (EPF), by changing the flux of Mn into or the proportion of protein bound Mn within the EPF. By linking shell Mn/Ca ratios to the endogenous and environmental factors that determine growth and metabolic activity, this study helps to explain the lack of a consistent relationship between shell Mn/Ca in marine bivalve shell calcite and seawater particulate and dissolved Mn2+ concentrations. The use of Mn content from M. edulis

  4. Manganese

    Science.gov (United States)

    Manganese is a mineral that is found in several foods including nuts, legumes, seeds, tea, whole grains, ... body requires it to function properly. People use manganese as medicine. Manganese is used for prevention and ...

  5. Generalized Anxiety and Major Depressive syndrome measured by the SCL-90-R in Two Manganese (Mn) Exposed Ohio Towns

    Science.gov (United States)

    Objective: Environmental exposure to manganese (Mn) may cause generalized anxiety (GA) and major depression (MD) in residents living in Mn-exposed areas. Marietta and East Liverpool are two Ohio towns identified as having elevated levels of Mn. The objective was to determine if l...

  6. Generalized Anxiety and Major Depressive syndrome measured by the SCL-90-R in Two Manganese (Mn) Exposed Ohio Towns

    Science.gov (United States)

    Objective: Environmental exposure to manganese (Mn) may cause generalized anxiety (GA) and major depression (MD) in residents living in Mn-exposed areas. Marietta and East Liverpool are two Ohio towns identified as having elevated levels of Mn. The objective was to determine if l...

  7. Phosphorescence detection of manganese(VII) based on Mn-doped ZnS quantum dots

    Science.gov (United States)

    Deng, Pan; Lu, Li-Qiang; Cao, Wei-Cheng; Tian, Xi-Ke

    2017-02-01

    The phosphorescent L-cysteine modified manganese-doped zinc sulfide quantum dots (L-cys-MnZnS QDs) was developed for a highly sensitive detection of permanganate anions (MnO4-). L-cys-MnZnS QDs, which were easily synthesized in aqueous media using safe and low-cost materials, can emit intense phosphorescence even though the solution was not deoxygenated. However, the phosphorescence of L-cys-Mn-ZnS QDs was strongly quenched by MnO4- ascribed to the oxidation of L-cys and the increase of surface defects on L-cys-MnZnS QDs. Under the optimal conditions, L-cys-MnZnS QDs offer high selectivity over other anions for MnO4- determination, and good linear Stern-Volmer equation was obtained for MnO4- in the range of 0.5-100 μM with a detection limit down to 0.24 μM. The developed method was finally applied to the detection of MnO4- in water samples, and the spike-recoveries fell in the range of 95-106%.

  8. Conformational adaptation and manipulation of manganese tetra(4-pyridyl)porphyrin molecules on Cu(111)

    Science.gov (United States)

    Chen, Xianwen; Lei, Shulai; Lotze, Christian; Czekelius, Constantin; Paulus, Beate; Franke, Katharina J.

    2017-03-01

    Porphyrins are highly flexible molecules and well known to adapt to their local environment via conformational changes. We studied the self-assembly of manganese meso-tetra(4-pyridyl)porphyrin (Mn-TPyP) molecules on a Cu(111) surface by low temperature scanning tunneling microscopy (STM) and atomic force microscopy (ATM). We observe molecular chains along the ⟨1 1 ¯ 0 ⟩ direction of the substrate. Within these chains, we identify two molecular conformations, which differ by the orientation of the upward bending of the macrocycle. Using density functional theory, we show that this saddle shape is a consequence of the rotation and inclination of the pyridyl groups towards Cu adatoms, which stabilize the metal-organic chains. The molecular conformations obey a strict alternation, reflecting the mutual enforcement of conformational adaptation in densely packed structures. Tunneling electrons from the STM tip can induce changes in the orientation of the pyridyl endgroups. The switching behaviour varies with the different adsorption configurations.

  9. Influence of MnC2O4 microadditives on combustion characteristics of CuO/Al nanoenergetics

    Science.gov (United States)

    Painuly, Madhusudan; Patel, Vinay Kumar; Bhattacharya, Shantanu

    2016-05-01

    In this work, we have investigated the catalytic effect of MnC2O4 microrods on combustion characteristics of CuO/nAl nanoenergetic composites. CuO nanorods were prepared by solid state synthesis method using the nonionic surfactant of poly(ethylene)glycol of molecular weight 400 (PEG400). The crystal information and microstructure of CuO/nAl nanoenergetics were studied by X-ray diffractometry and Transmission Electron microscopy. Microrods shaped manganese oxalate (MnC2O4) were fabricated by using mild thermal precipitation and aging process and confirmed by energy dispersive X-ray spectroscopy (EDS). The microstructures of MnC2O4 microrods and the nanoenergetic composites of CuO/nAl/MnC2O4 were characterized by Field emission scanning electron microscopy (FE-SEM) imaging. The addition of MnC2O4 microrods has demonstrated a significant enhancement in dynamic pressure-time characteristics of CuO/nAl nanoenergetics.

  10. Superoxide radical anion scavenging and dismutation by some Cu2+ and Mn2+ complexes: A pulse radiolysis study

    Science.gov (United States)

    Joshi, Ravi

    2017-10-01

    Copper (Cu) and manganese (Mn) ions are catalytic centers, in complexed form, in scavenging and dismutation process of superoxide radicals anion (O2.-) by superoxide dismutase enzyme. In the present work, fast reaction kinetics and mechanism of scavenging and dismutation of O2.- by Cu2+, Mn2+ and their complexes formed with some natural ligands have been studied using pulse radiolysis technique. Catechol, gentisic acid, tetrahydroxyquinone, tyrosine, tryptophan, embelin and bilirubin have been used as low molecular weight natural ligands for Cu2+ and Mn2+ to understand superoxide radical scavenging and dismutation reactions. These complexes have been found to be efficient scavengers of O2.- (k 107-109 M-1 s-1). The effects of nature of metal ion and ligand, and stoichiometry of complex on scavenging reaction rate constants are reported. Higher scavenging rate constants have been observed with complexes of: (1) Cu2+ as compared to Mn2+, and (2) at [ligand]/[metal] ratio of one as compared to two. A clear evidence of O2.- dismutation by free metal ions and some of the complexes has been observed. The study suggests that complexes of Cu2+ and Mn2+ with small natural ligands can also act as SOD mimics.

  11. Spectral Interferences Manganese (Mn) - Europium (Eu) Lines in X-Ray Fluorescence Spectrometry Spectrum

    Science.gov (United States)

    Tanc, Beril; Kaya, Mustafa; Gumus, Lokman; Kumral, Mustafa

    2016-04-01

    X-ray fluorescence (XRF) spectrometry is widely used for quantitative and semi quantitative analysis of many major, minor and trace elements in geological samples. Some advantages of the XRF method are; non-destructive sample preparation, applicability for powder, solid, paste and liquid samples and simple spectrum that are independent from chemical state. On the other hand, there are some disadvantages of the XRF methods such as poor sensitivity for low atomic number elements, matrix effect (physical matrix effects, such as fine versus course grain materials, may impact XRF performance) and interference effect (the spectral lines of elements may overlap distorting results for one or more elements). Especially, spectral interferences are very significant factors for accurate results. In this study, semi-quantitative analyzed manganese (II) oxide (MnO, 99.99%) was examined. Samples were pelleted and analyzed with XRF spectrometry (Bruker S8 Tiger). Unexpected peaks were obtained at the side of the major Mn peaks. Although sample does not contain Eu element, in results 0,3% Eu2O3 was observed. These result can occur high concentration of MnO and proximity of Mn and Eu lines. It can be eliminated by using correction equation or Mn concentration can confirm with other methods (such as Atomic absorption spectroscopy). Keywords: Spectral Interferences; Manganese (Mn); Europium (Eu); X-Ray Fluorescence Spectrometry Spectrum.

  12. Surface characterization of ZnO/ZnMn{sub 2}O{sub 4} and Cu/Mn{sub 3}O{sub 4} powders obtained by thermal degradation of heterobimetallic complexes

    Energy Technology Data Exchange (ETDEWEB)

    Barrault, Joeel, E-mail: joel.barrault@univ-poitiers.fr [CNRS-Universite de Poitiers, LACCO/Laboratoire de catalyse en Chimie Organique, UMR6503, ENSIP, 1 rue Marcel Dore, 86022 Poitiers cedex (France); Makhankova, Valeriya G., E-mail: leram@univ.kiev.ua [Department of Inorganic Chemistry, Kyiv National Taras Shevchenko University, Volodymyrska str. 64, Kyiv 01601 (Ukraine); Khavryuchenko, Oleksiy V.; Kokozay, Vladimir N. [Department of Inorganic Chemistry, Kyiv National Taras Shevchenko University, Volodymyrska str. 64, Kyiv 01601 (Ukraine); Ayrault, Philippe [CNRS-Universite de Poitiers, LACCO/Laboratoire de catalyse en Chimie Organique, UMR6503, ENSIP, 1 rue Marcel Dore, 86022 Poitiers cedex (France)

    2012-03-15

    From the selective transformation of the heterometallic (Zn-Mn or Cu-Mn) carboxylate complexes with 2,2 Prime -bipyridyl by thermal degradation at relatively low (350 Degree-Sign C) temperature, it was possible to get either well defined spinel ZnMn{sub 2}O{sub 4} over zinc oxide or well dispersed copper particles surrounded by a manganese oxide (Mn{sub 3}O{sub 4}) in a core-shell like structure. Morphology of the powder surface was examined by scanning electron microscopy with energy dispersive X-ray microanalysis (SEM/EDX). Surface composition was determined by X-ray photoelectron spectroscopy (XPS). Specific surface of the powders by nitrogen adsorption was found to be 33{+-}0.2 and 9{+-}0.06 m{sup 2} g{sup -1} for Zn-Mn and Cu-Mn samples, respectively, which is comparable to those of commercial products. - Graphical abstract: From the selective transformation of heterometallic (Zn-Mn or Cu-Mn) carboxylate complexes, it was possible to get either well defined spinel ZnMn{sub 2}O{sub 4} over zinc oxide or well dispersed copper particles surrounded by a manganese oxide (Mn{sub 3}O{sub 4}) in a core-shell like structure. Highlights: Black-Right-Pointing-Pointer Thermal degradation of heterometallic complexes results in fine disperse particles. Black-Right-Pointing-Pointer Core-shell Cu/Mn{sub 3}O{sub 4} particles are obtained. Black-Right-Pointing-Pointer ZnMn{sub 2}O{sub 4} spinel layer covers ZnO particles.

  13. Manganese superoxide dismutase (MnSOD catalyzes NO-dependent tyrosine residue nitration

    Directory of Open Access Journals (Sweden)

    SRDJAN STOJANOVIC

    2005-04-01

    Full Text Available The peroxynitrite-induced nitration of manganese superoxide dismutase (MnSOD tyrosine residue, which causes enzyme inactivation, is well established. This led to suggestions that MnSOD nitration and inactivation in vivo, detected in various diseases associated with oxidative stress and overproduction of nitric monoxide (NO, conditions which favor peroxynitrite formation, is also caused by peroxynitrite. However, our previous in vitro study demonstrated that exposure of MnSOD to NO led to NO conversion into nitrosonium (NO+ and nitroxyl (NO– species, which caused enzyme modifications and inactivation. Here it is reported that MnSOD is tyrosine nitrated upon exposure to NO, as well as that MnSOD nitration contributes to inactivation of the enzyme. Collectively, these observations provide a compelling argument supporting the generation of nitrating species in MnSOD exposed to NO and shed a new light on MnSOD tyrosine nitration and inactivation in vivo. This may represent a novel mechanism by which MnSOD protects cell from deleterious effects associated with overproduction of NO. However, extensive MnSOD modification and inactivation associated with prolonged exposure to NO will amplify the toxic effects caused by increased cell superoxide and NO levels.

  14. Bioelectrochemical Mn(II) leaching from manganese ore by Lactococcus lactis SK071115.

    Science.gov (United States)

    Jeon, Bo Young; Park, Doo Hyun

    2011-02-01

    L. lactis sk071115 has been shown to grow more actively and generate lower levels of lactate in glucose-defined medium with nitrate than in medium with Mn(IV). By adding Mn(IV) to a L. lactis culture, lactate production was relatively reduced in combination with Mn(II) production, but cell mass production levels did not increase. Both cell-free extract and intact L. lactis cells reacted electrochemically with Mn(IV) but did not react with Mn(II) upon cyclic voltammetry using neutral red (NR) as an electron mediator. A modified graphite felt cathode with NR (NR-cathode) was employed to induce electrochemical reducing equivalence for bacterial metabolism. Cell-free L. lactis extract catalyzed the reduction of Mn(IV) to Mn(II) under both control and electrochemical reduction conditions; however, the levels of Mn(II) generated under electrochemical reduction conditions were approximately 4 times those generated under control conditions. The levels of Mn(II) generated by the catalysis of L. lactis immobilized in the NR-cathode (L-NR-cathode) under electrochemical reduction conditions were more than 4 times that generated under control conditions. Mn(II) production levels were increased by approximately 2.5 and 4.5 times by the addition of citrate to the reactant under control and electrochemical reduction conditions, respectively. The cumulative Mn(II) produced from manganese ore by catalysis of the L-NR-cathode for 30 days reached levels of approximately 3,800 and 16,000 mg/l under control and electrochemical reduction conditions, respectively. In conclusion, the electrochemical reduction reaction generated by the NR-cathode activated the biochemical reduction of Mn(IV) to Mn(II) by L. lactis.

  15. Preparation of nanoporous Ni and Ni-Cu by dealloying of rolled Ni-Mn and Ni-Cu-Mn alloys

    Energy Technology Data Exchange (ETDEWEB)

    Hakamada, Masataka, E-mail: masataka-hakamada@aist.go.j [Materials Research Institute for Sustainable Development, National Institute of Advanced Industrial Science and Technology (AIST), 2266-98 Anagahora, Shimosihidami, Moriyama, Nagoya 463-8560 (Japan); Mabuchi, Mamoru [Department of Energy Science and Technology, Graduate School of Energy Science, Kyoto University, Kyoto 606-8501 (Japan)

    2009-10-19

    Nanoporous Ni, Ni-Cu and Cu with ligament sizes of 10-20 nm were fabricated by dealloying rolled Ni-Mn, Cu-Ni-Mn and Cu-Mn alloys, respectively. Unlike conventional Raney nickel composed of brittle Ni-Al intermetallic compounds, the initial alloys had good workability. Ni and Cu atoms formed a homogeneous solid solution in the nanoporous architecture. The ligament sizes of nanoporous Ni and Ni-Cu were smaller than that of nanoporous Cu, reflecting the difference between the surface diffusivities of Ni and Cu.

  16. Recovery of zinc and manganese, and other metals (Fe, Cu, Ni, Co, Cd, Cr, Na, K) from Zn-MnO2 and Zn-C waste batteries: Hydroxyl and carbonate co-precipitation from solution after reducing acidic leaching with use of oxalic acid

    Science.gov (United States)

    Sobianowska-Turek, A.; Szczepaniak, W.; Maciejewski, P.; Gawlik-Kobylińska, M.

    2016-09-01

    The article discusses the current situation of the spent batteries and portable accumulators management. It reviews recycling technologies of the spent batteries and portable accumulators which are used in the manufacturing installations in the world. Also, it presents the authors' research results on the reductive acidic leaching of waste material of the zinc-carbon batteries (Zn-C) and zinc-manganese batteries (alkaline Zn-MnO2) delivered by a company dealing with mechanical treatment of this type of waste stream. The research data proved that the reductive acidic leaching (H2SO4 + C2H2O4) of the battery's black mass allows to recover 85.0% of zinc and 100% of manganese. Moreover, it was found that after the reductive acidic leaching it is possible to recover nearly 100% of manganese, iron, cadmium, and chromium, 98.0% of cobalt, 95.5% of zinc, and 85.0% of copper and nickel from the solution with carbonate method. On the basis of the results, it is possible to assume that the carbonate method can be used for the preparation of manganese-zinc ferrite.

  17. Physiological highlights of manganese toxicity symptoms in soybean plants: Mn toxicity responses.

    Science.gov (United States)

    Santos, Elcio Ferreira; Kondo Santini, José Mateus; Paixão, Amanda Pereira; Júnior, Enes Furlani; Lavres, José; Campos, Marcelo; Reis, André Rodrigues Dos

    2017-04-01

    Manganese (Mn) is an essential element for plants; however, high concentrations in certain soil conditions can cause toxicity symptoms in the plant tissue. Here, we describe Mn toxicity symptoms and Mn toxicity responses in soybean plants. Soybean plants exposed to excess Mn showed reductions in the CO2 assimilation rate and stomatal conductance, which in turn resulted in decreased shoot biomass. Furthermore, peroxidase (POD), superoxide dismutase (SOD), and catalase (CAT) activity were higher in plants grown with the highest Mn concentration. The Mn doses increased the activity of antioxidant enzymes such as CAT, POD, and SOD. The toxicity symptoms presented by the leaves included hypertrophying of the adaxial epidermis and the formation of necrotic areas with purple-colored veins. Dramatic movement of calcium from the healthy region to the purple-colored necrotic region was observed, as was the exit of potassium from the necrotic area to the healthy region of the tissue. The high activities of POD and SOD in the presence of high Mn compartmented in the roots was the main physiological responses at high Mn uptake by soybean plants. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  18. In situ TEM observation of novel chemical evolution of MnBr2 catalyzed by Cu under electron beam irradiation

    Science.gov (United States)

    Wang, Wei; Bai, Xianwei; Guan, Xiangxiang; Shen, Xi; Yao, Yuan; Wang, Yanguo; Zou, Bingsuo; Yu, Richeng

    2017-10-01

    Manganese bromide has attracted enormous attention for its applications in the syntheses of organic-inorganic hybrid compounds. A complete understanding of structural and chemical stabilities of MnBr2 is important for controlling its properties. Here, we focus on the irradiation resistance of MnBr2. The chief purpose of this research is reached by in situ transmission electron microscopy. It is demonstrated that the deliquescent MnBr2 powder is prone to adsorb the vapor in air, and the hydrous MnBr2 can be decomposed under its continuous exposure to electron beam, indicated by a transmission electron microscope via the catalysis of Cu grid at room temperature.

  19. Bioaccumulation of manganese and its toxicity in feral pigeons (Columba livia) exposed to manganese oxide dust (Mn{sub 3}O{sub 4})

    Energy Technology Data Exchange (ETDEWEB)

    Sierra, P.; Chakrabarti, S.; Tounkara, R.; Loranger, S.; Kennedy, G.; Zayed, J. [Univ. of Montreal (Canada)

    1998-11-01

    Manganese tetroxide (Mn{sub 3}O{sub 4}) is a product from the combustion of methylcyclopentadienyl manganese tricarbonyl. Exposure to high levels of manganese can lead to serious health effects especially to the central nervous and respiratory systems. Very few studies on the effects of long-term low level exposure to Mn{sub 3}O{sub 4} have been reported. The present study was therefore conducted to examine the bioaccumulation and toxicity of manganese in various organs of feral pigeons (Columba kivia) when exposed to low levels of Mn{sub 3}O{sub 4} via inhalation and hence to find any possible relationship between these two parameters. A total of 22 pigeons was exposed to 239 {micro}g/m{sup 3} of manganese for 7 h/day, 5 days/week for 5, 9, and 13 consecutive weeks. Manganese concentrations in various tissues, e.g., brain (mesencephalon), lung, liver, intestine, pancreas, kidney, muscle, bone, and whole blood, were measured by neutron activation analysis. Various biochemical parameters in blood, e.g., hematocrit, total proteins, glucose, uric acid, alinine aminotransferase, total iron, blood urea nitrogen and triglycerides, were also measured.

  20. Formation of manganese phosphate and manganese carbonate during long-term sorption of Mn(2+) by viable Shewanella putrefaciens: effects of contact time and temperature.

    Science.gov (United States)

    Chubar, Natalia; Avramut, Cristina; Visser, Tom

    2015-04-01

    The influence of temperature (5, 10, 22 and 30 °C) on the long-term (30 days) sorption of Mn(2+) by viable Shewanella putrefaciens was studied by FTIR and EXAFS. The additional Mn-removal capacity of these bacteria was found to result from the surface precipitation of Mn-containing inorganic phases. The chemical composition of the Mn-containing precipitates is temperature and contact-time dependent. Mn(ii) phosphate and Mn(ii) carbonate were the two major precipitates formed in 1000 mL batches at 10, 22 and 30 °C. The ratio of Mn(ii) phosphate to Mn(ii) carbonate was a function of the contact time. After 30 days, MnCO3 was the dominant phase in the precipitates at 10, 22 and 30 °C; however, MnCO3 did not form at 5 °C. Mn(ii) phosphate was the only precipitate formed at 5 °C over 30 days. The biosynthesis of Extracellular Polymeric Substances (EPS) was much greater at the lowest temperature (5 °C); however, these polymeric sugars did not contribute to the additional removal of Mn(ii) under the experimental conditions. This work is one of the first reports demonstrating the ability of microbes to bioprecipitate manganese phosphate and manganese carbonate. Because of the focus on interfacial processes, this is the first report showing a molecular-level mechanism for manganese carbonate formation (in contrast to the traditionally studied aged minerals).

  1. Analytical and mineralogical study of a Ghana manganese ore: Quantification of Mn speciation and effect of mechanical activation.

    Science.gov (United States)

    He, Hongping; Cao, Jianglin; Duan, Ning

    2016-11-01

    In-depth understanding of the manganese ore would be beneficial to make the best use more environmental-friendly. A Ghana manganese ore before/after mechanical activation (MA) was therefore extensively characterized in our investigation. Surface Mn(4+)(35.5%), Mn(3+)(35.9%), Mn(2+)(28.6%) were detected by XPS, though XRD only revealed the presence of Mn(2+)-containing minerals. Thermal decomposition curve of manganese ore obtained by TG-DSC was divided into four stages from 373.15 K to 1273.15 K, which were quite consistent with the pattern of generated gases obtained by TG-FTIR and the theoretical thermodynamics analysis of the incorporated components involving ΔGT(θ) and Kp(θ). Mn species distribution showed no difference for manganese ores before/after MA, but quantitative analysis showed the decrease of residual Mn content (cannot be extracted effectively by acid, from about 12% to 1%), and thereby the increased contents of other four Mn species (exchangeables, carbonates, oxides, organics), which was suggested to be correlated with the dissociation of Mn-containing flocs and SiO2 particles witnessed by SEM-EDS. It was also found that MA could obviously promote the Mn dissolution kinetics in acid condition, though the dissolution of manganese ore before/after MA were both diffusion controlled. This investigation gives benignant inspiration for the resource utilization of manganese ore, taking the increasingly severer situation of Mn resource supply into consideration.

  2. Cubane-type Cu(II)4 and Mn(II)2Mn(III)2 complexes based on pyridoxine: a versatile ligand for metal assembling.

    Science.gov (United States)

    Marino, Nadia; Armentano, Donatella; Mastropietro, Teresa F; Julve, Miguel; De Munno, Giovanni; Martínez-Lillo, José

    2013-10-21

    By using Vitamin B6 in its monodeprotonated pyridoxine form (PN-H) [PN = 3-hydroxy-4,5-bis(hydroxymethyl)-2-methylpyridine], two tetranuclear compounds of formula [Mn4(PN-H)4(CH3CO2)3Cl2]Cl·2CH3OH·2H2O (1) and [Cu4(PN-H)4Cl2(H2O)2]Cl2 (2) have been synthesized and magneto-structurally characterized. 1 crystallizes in the triclinic system with space group P1 whereas 2 crystallizes in the orthorhombic system with Fdd2 as space group. They exhibit Mn(II)2Mn(III)2 (1) and Cu(II)4 (2) cubane cores containing four monodeprotonated pyridoxine groups simultaneously acting as chelating and bridging ligands (1 and 2), three bridging acetate ligands in the syn-syn conformation (1), and two terminally bound chloride anions (1 and 2) plus two coordinated water molecules (2). The electroneutrality is achieved by the presence of chloride counterions in both compounds. Tri- [Mn(1) and Mn(3)] and divalent [Mn(2) and Mn(4)] manganese centers coexist in 1, all being six-coordinate with distorted Mn(1/3)O6 and Mn(2/4)O5Cl octahedral surroundings, respectively, the equatorial Mn-O bonds being about 0.2 Å shorter at the former ones. The two crystallographically independent copper(II) ions in 2 are five-coordinate in somewhat distorted CuO5 [Cu(1)] and CuO4Cl [Cu(2)] square pyramidal geometries. The values of the intracore metal-metal separation cover the ranges 3.144(1)-3.535(1) (1) and 2.922(6)-3.376(1) Å (2). The magnetic properties of 1 and 2 were investigated in the temperature range 1.9-300 K, and they correspond to an overall antiferromagnetic behavior with susceptibility maxima at 5.0 (1) and 65.0 K (2). The analysis of the magnetic susceptibility data showed the coexistence of intracore antiferro- and ferromagnetic interactions in the two compounds. Their values compare well with those existing in the literature for the parent systems.

  3. First-principles spin-transfer torque in CuMnAs |GaP |CuMnAs junctions

    Science.gov (United States)

    Stamenova, Maria; Mohebbi, Razie; Seyed-Yazdi, Jamileh; Rungger, Ivan; Sanvito, Stefano

    2017-02-01

    We demonstrate that an all-antiferromagnetic tunnel junction with current perpendicular to the plane geometry can be used as an efficient spintronic device with potential high-frequency operation. By using state-of-the-art density functional theory combined with quantum transport, we show that the Néel vector of the electrodes can be manipulated by spin-transfer torque. This is staggered over the two different magnetic sublattices and can generate dynamics and switching. At the same time the different magnetization states of the junction can be read by standard tunneling magnetoresistance. Calculations are performed for CuMnAs |GaP |CuMnAs junctions with different surface terminations between the antiferromagnetic CuMnAs electrodes and the insulating GaP spacer. We find that the torque remains staggered regardless of the termination, while the magnetoresistance depends on the microscopic details of the interface.

  4. Efficient manganese luminescence induced by Ce3+-Mn2+ energy transfer in rare earth fluoride and phosphate nanocrystals

    Directory of Open Access Journals (Sweden)

    Ding Yun

    2011-01-01

    Full Text Available Abstract Manganese materials with attractive optical properties have been proposed for applications in such areas as photonics, light-emitting diodes, and bioimaging. In this paper, we have demonstrated multicolor Mn2+ luminescence in the visible region by controlling Ce3+-Mn2+ energy transfer in rare earth nanocrystals [NCs]. CeF3 and CePO4 NCs doped with Mn2+ have been prepared and can be well dispersed in aqueous solutions. Under ultraviolet light excitation, both the CeF3:Mn and CePO4:Mn NCs exhibit Mn2+ luminescence, yet their output colors are green and orange, respectively. By optimizing Mn2+ doping concentrations, Mn2+ luminescence quantum efficiency and Ce3+-Mn2+ energy transfer efficiency can respectively reach 14% and 60% in the CeF3:Mn NCs.

  5. Psychological symptoms and quality of life among residents exposed to long-term, low-dose environmental manganese (Mn)

    Science.gov (United States)

    Objective: Elevated levels of air manganese (air-Mn) exposure have been associated with adverse health effects. This study examined the relationship of air-Mn concentrations with mood and quality of life.Participants and methods: 185 residents (age mean (M)=55.13±10.88; ed...

  6. Influence of manganese concentration on the electron magnetic resonance spectrum of Mn{sup 2+} in CdO

    Energy Technology Data Exchange (ETDEWEB)

    Biasi, R.S. de, E-mail: rsbiasi@ime.eb.b [Departamento de Engenharia Mecanica e de Materiais, Instituto Militar de Engenharia, 22290-270 Rio de Janeiro, RJ (Brazil); Grillo, M.L.N. [Instituto de Fisica, Universidade do Estado do Rio de Janeiro, 20550-013 Rio de Janeiro, RJ (Brazil)

    2009-10-19

    Electron magnetic resonance spectra of manganese-doped cadmium oxide (CdO) have been studied at room temperature for Mn concentrations between 0.10 and 1.00 mol%. The results suggest that the range of the exchange interaction between Mn{sup 2+} ions is about 0.56 nm.

  7. Psychological symptoms and quality of life among residents exposed to long-term, low-dose environmental manganese (Mn)

    Science.gov (United States)

    Objective: Elevated levels of air manganese (air-Mn) exposure have been associated with adverse health effects. This study examined the relationship of air-Mn concentrations with mood and quality of life.Participants and methods: 185 residents (age mean (M)=55.13±10.88; ed...

  8. Evaluation of the bioaccessible fractions of Fe, Zn, Cu and Mn in baby foods.

    Science.gov (United States)

    do Nascimento da Silva, Emanueli; Leme, Ana Beatriz Perriello; Cidade, Mirla; Cadore, Solange

    2013-12-15

    The bioaccessibility of four essential micronutrients (iron, zinc, copper and manganese) in some baby foods was evaluated using an in vitro gastrointestinal digestion model. For all of the flour-based foods evaluated, the bioaccessibility of Zn was low, while the bioaccessibility of Cu was above 50%. For these samples, the bioaccessibility of Mn was lower than 50%. Two samples composed of oat and rice flour and whole wheat flour demonstrated a lower bioaccessible fraction of Fe (less than 35%), while the sample made with wheat flour showed high Fe bioaccessibility (approximately 80%). For vegetable- and meat-based baby foods, the Fe bioaccessibility was greater than 80% in samples that contained meat and chicken and approximately 20% for the banana-based sample. The bioaccessibility of Zn was small for all of the foods studied, and in some cases, no Zn appeared to be released. The sample containing banana showed 100% Cu bioaccessibility, in contrast to meat and chicken-based samples, whose Cu bioaccessibility values were less than 50%. The opposite effect occurred for Mn, in which samples containing meat and chicken presented a bioaccessible fraction greater than 50% while the banana-based sample had a fraction less than 50%. © 2013 Elsevier B.V. All rights reserved.

  9. Spin polarization and exchange coupling of Cu and Mn atoms in paramagnetic CuMn diluted alloys induced by a Co layer

    Science.gov (United States)

    Abes, M.; Atkinson, D.; Tanner, B. K.; Charlton, T. R.; Langridge, Sean; Hase, T. P. A.; Ali, M.; Marrows, C. H.; Hickey, B. J.; Neudert, A.; Hicken, R. J.; Arena, D.; Wilkins, S. B.; Mirone, A.; Lebègue, S.

    2010-11-01

    Using the surface, interface, and element specificity of x-ray resonant magnetic scattering in combination with x-ray magnetic circular dichroism, we have spatially resolved the magnetic spin polarization, and the associated interface proximity effect, in a Mn-based high-susceptibility material close to a ferromagnetic Co layer. We have measured the magnetic polarization of Mn and Cu3d electrons in paramagnetic CuMn alloy layers in [Co/Cu(x)/CuMn/Cu(x)]20 multilayer samples with varying copper layer thicknesses from x=0 to 25Å . The size of the Mn and CuL2,3 edge dichroism shows a decrease in the Mn-induced polarization for increasing copper thickness indicating the dominant interfacial nature of the Cu and Mn spin polarization. The Mn polarization is much higher than that of Cu. Evidently, the Mn moment is a useful probe of the local spin density. Mn atoms appear to be coupled antiferromagnetically with the Co layer below x=10Å and ferromagnetically coupled above. In contrast, the interfacial Cu atoms remain ferromagnetically aligned to the Co layer for all thicknesses studied.

  10. Glassy dynamics in CuMn thin-film multilayers

    Science.gov (United States)

    Zhai, Qiang; Harrison, David C.; Tennant, Daniel; Dalhberg, E. Dan; Kenning, Gregory G.; Orbach, Raymond L.

    2017-02-01

    Thin-film multilayered spin-glass CuMn/Cu structures display glassy dynamics. The freezing temperature Tf was measured for 40 layers of CuMn films of thickness L =4.5 ,9.0 , and 20.0 nm, sandwiched between nonmagnetic Cu layers of thickness ≈60 nm. The Kenning effect, Tf∝lnL , is shown to follow from power-law dynamics where the correlation length grows from nucleation as ξ (t ,T ) =c1a0(t/τ0) c2(T /Tg) , leading to [(Tf/Tg) c2ln(tco/τ0) ] +lnc1=ln(L /a0) . Here, Tg is the bulk spin-glass temperature, c1 and c2 are constants determined from the spin-glass dynamics, tco is the time for the correlation length to grow to the film thickness, τ0 is a characteristic exchange time ≈ℏ /kBTg , and a0 is the average Mn-Mn separation. For t ≥tco , the magnetization dynamics are simple activated, with a single activation energy Δmax(L ) /kBTg=(1 /c2) [ln(L /a0) -lnc1] that does not change with time. Values for all these parameters are found for the three values of L explored in these measurements. We find experimentally Δmax(L ) /kB =907 , 1246, and 1650 K, respectively, for the three CuMn thin-film multilayer thicknesses, consistent with power-law dynamics. We perform a similar analysis based on the activated dynamics of the droplet model and find a much larger spread for Δmax(L ) than found experimentally.

  11. Accumulation of heavy metals (Co, Cr, Cu, Mn, Zn in the freshwater alga Ulva type, sediments and water of the Wielkopolska region, Poland

    Directory of Open Access Journals (Sweden)

    Andrzej Rybak

    2013-12-01

    Full Text Available The concentration of five trace elements: cobalt (Co, chrome (Cr, copper (Cu, manganese (Mn and zinc (Zn was determined in the Ulva thalli, in the water and sediment collection from several inland sites (lakes, stream and river from the Wielkopolska region during summer 2010. The multielemental analysis of the heavy metal concentration was carried out with the use of ICP-OES method. The aim of this study was to determine the role of tubular forms as biomonitoring species. The relative abundance of metals in sediment decreased in the order: Mn > Zn > Cu > Cr > Co and in the water: Cr > Mn > Zn > Cu > Co. In Ulva thalli the distribution order from higher to lower was Mn > Zn > Cr > Cu > Co. The results indicate that the concentration changes of heavy metals in thallus, water and sediment have some differences, but concentration distribution tends to be similar, because among the analysed heavy metals Mn has the highest concentrations while Co the lowest abundance in the thalli and sediment of all the sites. Possibility to use freshwater species from Ulva genus as bioindicators of water pollution by manganese requires further study.

  12. Mechanisms for the Movement of Fe,Mn,Cu and Zn to Plant Roots in Loessal Soil and Lou Soil

    Institute of Scientific and Technical Information of China (English)

    XUMINGGANG; ZHANGYIPING; 等

    1996-01-01

    The pot experiments were conducted in the artificial climate laboratories to determine the relative importance of mass flow and diffusion in supplying ,Fe,Mn,Cu,and Zn to wheat,soybean and maize plants growing in loessal soil and lou soil.It was found that the calculated relative contribution of mass flow of iron,manganese,copper and zinc to plant uptake varied from 5% to more than 100%,depending on the crop species and soil types as well as plant growth stage,soil moisture,atmosphere humidity,etc.The results also showed that the major transportation mechanisms of these micronutrients in soil-root system varied with the crop and its growth,climate and soil,singnificantly,In general,mass flow was more important for Cu and Zn and diffusion was more significant for Fe and Mn at the seedling stage.

  13. Adsorption of antimony(V) onto Mn(II)-enriched surfaces of manganese-oxide and FeMn binary oxide.

    Science.gov (United States)

    Liu, Ruiping; Xu, Wei; He, Zan; Lan, Huachun; Liu, Huijuan; Qu, Jiuhui; Prasai, Tista

    2015-11-01

    Manganese(IV) oxide [Mn(IV)] potentially oxidizes antimony(III) [Sb(III)] to antimony(V) [Sb(V)] and improves Sb removal by FeMn binary oxide (FMBO) through an oxidation-adsorption mechanism. This study focused on the effect of Mn(IV) reductive dissolution by potassium sulfite (K2SO3) on Sb(V) adsorption onto manganese oxide (Mn-oxide) and FMBO. The maximum Sb(V) adsorption (Qmax,Sb(V)) increased from 1.0 to 1.1 mmol g(-1) for FMBO and from 0.4 to 0.6 mmol g(-1) for Mn-oxide after pretreatment with 10 mmol L(-1) K2SO3. The addition of 2.5 mmol L(-1) Mn(2+) also significantly improved Sb(V) adsorption, and the observed Qmax,Sb(V) increased to 1.4 and 1.0 mmol g(-1) for FMBO and Mn-oxide, respectively, with pre-adsorbed Mn(2+). Neither K2SO3 nor Mn(2+) addition had any effect on Sb(V) adsorption onto iron oxide (Fe-oxide). Mn(2+) introduced by either Mn(IV) dissolution or addition tended to form outer-sphere surface complexes with hydroxyl groups on Mn-oxide surfaces (MnOOH). Mn(2+) at 2.5 mmol L(-1) shifted the isoelectric point (pHiep) from 7.5 to 10.2 for FMBO and from 4.8 to 9.2 for Mn-oxide and hence benefited Sb(V) adsorption. The adsorption of Sb(V) onto Mn(2+)-enriched surfaces contributed to the release of Mn(2+), and the X-ray photoelectron spectra also indicated increased binding energy of Mn 2p3/2 after the adsorption of Sb(V) onto K2SO3-pretreated FMBO and Mn-oxide. Sb(V) adsorption involved the formation of inner-sphere complexes and contributed to the release of Mn(2+). In the removal of Sb(III) by Mn-based oxides, the oxidation of Sb(III) to Sb(V) by Mn(IV) oxides had an effect; however, Mn(IV) dissolution and Mn(2+)-enrichment also played an important role.

  14. Evaluation of manganese uptake and toxicity in mouse brain during continuous MnCl2 administration using osmotic pumps.

    Science.gov (United States)

    Sepúlveda, M R; Dresselaers, T; Vangheluwe, P; Everaerts, W; Himmelreich, U; Mata, A M; Wuytack, F

    2012-01-01

    Manganese is a vital element and cofactor of many key enzymes, but it is toxic at high levels, causing pronounced disturbances in the mammalian brain. Magnetic resonance imaging (MRI) studies using manganese ions as a paramagnetic contrast agent are often limited by the neurotoxicity of Mn(2+) . In this work, we have explored a new in vivo model to study Mn(2+) uptake, distribution and neurotoxicity in mice by subcutaneous implantation of mini-osmotic pumps delivering MnCl(2) continuously for 21 days. Fractionated injections can reduce the toxicity; however, constant administration at very low doses using osmotic pumps caused a substantial effect on the T(1) contrast in MRI while reducing toxicity. Manganese-enhanced MRI documented fast but reversible Mn(2+) deposition largely in glomerular and mitral cell layers of the olfactory bulb, in the CA3 area of the hippocampus, and in the gray matter of the cerebellum. Mn(2+) accumulated as early as the first days after implantation, with a fast dispersal 9 days after stopping a 12-days Mn(2+) exposure. Prominent Mn(2+) accumulation was also seen in salivary glands and in the endocrine thyroid and posterior pituitary gland. These structures with enhanced Mn(2+) accumulation correlated well with those showing high expression of the secretory pathway Ca(2+) /Mn(2+) -ATPase (SPCA1), i.e. a transporter that could take part in Mn(2+) detoxification. Our new experimental model for continuous low-dosage administration of Mn(2+) is an easy alternative for enhancing Mn(2+) -based contrast in MEMRI studies, and might provide insight into the etiology of neuropathologies resulting from chronic Mn(2+) exposure in vivo.

  15. Manganese and Mn/Ca ratios in soil and vegetation in forests across the northeastern US: Insights on spatial Mn enrichment.

    Science.gov (United States)

    Richardson, J B

    2017-03-01

    Manganese (Mn) cycling in the Critical Zone is important because of its role as an essential nutrient and potential toxicity to plants and organisms. Quantifying Mn enrichment in terrestrial environments has been limited since Mn is monoisotopic. However, elemental ratios of Mn/Ca ratios may be used to determine spatial Mn enrichment and in aboveground and belowground pools. The objectives of this study were to quantify the spatial variation in Mn concentrations and Mn/Ca ratios in foliage, bolewood, forest floor, and mineral soil horizons across the northeastern United States and compare Mn/Ca ratios to estimate enrichment. Forest floor and mineral soil samples were collected from 26 study sites across the northeastern United States and analyzed by strong acid digestion. Foliage and bolewood was collected from 12 of the 26 sites and analyzed for total Mn and Ca. Our results show forest floor and mineral soil horizon Mn concentrations and Mn/Ca ratios were higher at Pennsylvania and New York sites than New Hampshire and Vermont sites. Using a modified isotope equation, enrichment factors (EF) for Mn/Ca ratios were calculated to be ~3.6 in the forest floor, upper and lower mineral soil horizons at sites in New York and Pennsylvania compared to reference sites in New Hampshire and Vermont. Foliar and bolewood Mn concentrations also decreased from Pennsylvania towards New Hampshire. Moreover, foliar and bolewood Mn concentrations were strongly correlated to forest floor, upper, and lower mineral soil Mn concentrations. It was hypothesized that internal cycling (uptake, throughfall, and litterfall) of Mn controls retention of enriched Mn in forests. Geologic influences from a lithologic gradient and soil pH gradient could also influence Mn enrichment in addition to Mn pollution. Ratios of Mn/Ca and other elemental ratios hold promise as geochemical tracers but require further development. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. A historical overview of the development of manganese (Mn) pharmacokinetic data under Section 211(b) of the Clean Air Act (CAA)

    Science.gov (United States)

    Abstract for Manganese 2016A historical overview of the development of manganese (Mn) pharmacokinetic data under Section 211(b) of the Clean Air Act (CAA)William K BoyesBackground. In the 1990’s, the use of methylcyclopentadienyl manganese tricarbonyl (MMT) as an octane-enh...

  17. A historical overview of the development of manganese (Mn) pharmacokinetic data under Section 211(b) of the Clean Air Act (CAA)

    Science.gov (United States)

    Abstract for Manganese 2016A historical overview of the development of manganese (Mn) pharmacokinetic data under Section 211(b) of the Clean Air Act (CAA)William K BoyesBackground. In the 1990’s, the use of methylcyclopentadienyl manganese tricarbonyl (MMT) as an octane-enh...

  18. Preparation-Properties Relation of Mn-Cu Hopcalite Catalyst

    Directory of Open Access Journals (Sweden)

    Ardita Mele

    2012-01-01

    Full Text Available Problem statement: The Mn-Cu hopcalite catalyst was used for the conversion of CO to CO2 at low temperatures. It was the catalyst of choice in the gas masks for respiratory protection in mines, aircrafts, military, spatial laboratories. Approach: The efficiency of hopcalite catalyst depends on its surface parameters. Its surface characteristics can be influenced from the chosen way of the MnO2 and CuO precipitation and from the pressure of pelletizing. Results: The hopcalite samples has been prepared by precipitation of MnO2 and by adding CuSO4 further in the solution the adsorption of Cu2+ ions on MnO2 particles surface is achieved. After acidification of the solution up to pH = 3 the copper is precipitated in form of Cu (OH2CuCO3 by adding NaHCO3. Precipitate was washed, dried, pressed, crushed, sieved (1-2 mm and calcined at 180°C for 3 h. MnO2 and hopcalite samples were characterized by XRD. The activity was evaluated by determination of its protection time and it was 610 min, better than activity of a commercial catalyst. Specific surface area, pore volume and density were measured by nitrogen adsorption and mercury intrusion porosimetry. The X-Ray diffractograms shows that the only crystallinity of hopcalite comes from MnO2, which is present mainly in amorphous form. By increasing the pressure in the pelletizing step, a significant decrease in the specific surface area (247.64-147.77 m2 g-1 and in the total pore volume (446-278 mm3 g-1 is observed in the hopcalite samples. Conclusion: The obtained hopcalite catalyst by the two step precipitation method shows high catalytic activity. The increasing pressure increases the strength and reduces the specific surface area and pore volume. A pressure of 500 kg cm-2 is recommended for the hopcalite production procedure.

  19. Characteristics of flake graphite in Ni-Mn-Cu cast iron. Part 2.

    Directory of Open Access Journals (Sweden)

    A. Janus

    2010-01-01

    Full Text Available The paper continues the article published by Archives of Foundry Engineering, vol. 9, issue 1/2009, pp. 185-290, that presented influence of chemical composition of hypo- and hypereutectic nickel-manganese-copper alloyed cast iron on properties of the contained flake graphite. In this second part of the research, effect of chemical composition of hypereutectic cast iron containing 3.5÷5.1% C, 1.7÷2.8% Si, 3.5÷10.5 %Ni, 2.0÷8.0% Mn, 0.1÷3.5% Cu, 0.14÷0.17% P and 0.02÷0.04% S on properties of flake graphite is determined. Evolution of graphite properties with changing eutecticity degree of the examined cast iron is presented. For selected castings, histograms of primary and eutectic graphite are presented, showing quantities of graphite precipitates in individual size ranges and their shape determined by the coefficient ξ defined as ratio of a precipitate area to square of its circumference. Moreover, presented are equations obtained by discriminant analysis to determine chemical composition of Ni-Mn-Cu cast iron which guarantee the most favourable distribution of A-type graphite from the point of view of castings properties.

  20. Manganese-enhanced MRI of rat brain based on slow cerebral delivery of manganese(II) with silica-encapsulated Mn x Fe(1-x) O nanoparticles.

    Science.gov (United States)

    Chen, Wei; Lu, Fang; Chen, Chiao-Chi V; Mo, Kuan-Chi; Hung, Yann; Guo, Zhi-Xuan; Lin, Chia-Hui; Lin, Ming-Huang; Lin, Yu-Hsuan; Chang, Chen; Mou, Chung-Yuan

    2013-09-01

    In this work, we report a monodisperse bifunctional nanoparticle system, MIO@SiO2 -RITC, as an MRI contrast agent [core, manganese iron oxide (MIO); shell, amorphous silica conjugated with rhodamine B isothiocyanate (RITC)]. It was prepared by thermal decomposition and modified microemulsion methods. The nanoparticles with varying iron to manganese ratios displayed different saturated magnetizations and relaxivities. In vivo MRI of rats injected intravenously with MIO@SiO2-RITC nanoparticles exhibited enhancement of the T1 contrast in brain tissue, in particular a time-delayed enhancement in the hippocampus, pituitary gland, striatum and cerebellum. This is attributable to the gradual degradation of MIO@SiO2-RITC nanoparticles in the liver, resulting in the slow release of manganese(II) [Mn(II)] into the blood pool and, subsequently, accumulation in the brain tissue. Thus, T1-weighted contrast enhancement was clearly detected in the anatomic structure of the brain as time progressed. In addition, T2*-weighted images of the liver showed a gradual darkening effect. Here, we demonstrate the concept of the slow release of Mn(II) for neuroimaging. This new nanoparticle-based manganese contrast agent allows one simple intravenous injection (rather than multiple infusions) of Mn(II) precursor, and results in delineation of the detailed anatomic neuroarchitecture in MRI; hence, this provides the advantage of the long-term study of neural function. Copyright © 2013 John Wiley & Sons, Ltd.

  1. Origin of the chemical shift in X-ray absorption near-edge spectroscopy at the Mn K-Edge in manganese oxide compounds

    NARCIS (Netherlands)

    de Vries, AH; Hozoi, L; Broer, R; Broer-Braam, H.B.

    2003-01-01

    The absorption edge in Mn K-edge X-ray absorption spectra of manganese oxide compounds shows a shift of several electronvolts in going from MnO through LaMnO3 to CaMnO3. On the other hand, in X-ray photoelectron spectra much smaller shifts are observed. To identify the mechanisms that cause the obse

  2. Origin of the chemical shift in X-ray absorption near-edge spectroscopy at the Mn K-Edge in manganese oxide compounds

    NARCIS (Netherlands)

    de Vries, AH; Hozoi, L.; Broer, R.

    2003-01-01

    The absorption edge in Mn K-edge X-ray absorption spectra of manganese oxide compounds shows a shift of several electronvolts in going from MnO through LaMnO3 to CaMnO3. On the other hand, in X-ray photoelectron spectra much smaller shifts are observed. To identify the mechanisms that cause the

  3. Catalytic behavior and synergistic effect of nanostructured mesoporous CuO-MnO{sub x}-CeO{sub 2} catalysts for chlorobenzene destruction

    Energy Technology Data Exchange (ETDEWEB)

    He, Chi, E-mail: chi_he@mail.xjtu.edu.cn [Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Department of Environmental Science and Engineering, School of Energy and Power Engineering, Xi’an Jiaotong University, Xi’an 710049 (China); Yu, Yanke [Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Shen, Qun [Research Center for Greenhouse Gases and Environmental Engineering, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201210 (China); Chen, Jinsheng, E-mail: jschen@iue.ac.cn [Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Qiao, Nanli [Department of Environmental Nano-materials, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China)

    2014-04-01

    Graphical abstract: - Highlights: • Mesoporous CuO-MnO{sub x}-CeO{sub 2} oxides with enhanced reducibility and oxygen mobility. • Incorporation of Cu and Mn ions causes abundant crystal defects and oxygen vacancies. • Surface oxygen concentration and active oxygen mobility determine the catalytic efficiency. • Catalysts with conspicuous chlorobenzene low-temperature removal activity and durability. - Abstract: Mesoporous CuO-MnO{sub x}-CeO{sub 2} composite metal oxides with different copper and manganese loadings were prepared by a urea-assistant hydrothermal method, and were further adopted for the complete catalytic combustion of chlorobenzene. The effects of reaction conditions such as inlet reagent concentration and water feed concentration on chlorobenzene combustion were also studied. The structure and textural properties of the synthesized catalysts were characterized via the XRD, N{sub 2} adsorption/desorption, FE-SEM, TEM, H{sub 2}-TPR, O{sub 2}-TPD, and XPS techniques. The characterization results reveal that the presence of a small amount of Mn species can facilitate the incorporation of Cu and Mn ions into ceria lattice to form Cu-Mn-Ce-O solid solution. The synergistic effect of Cu and Mn species can reduce the redox potential of the composite catalysts, and produce large amounts of oxygen vacancies in the interface of CuO{sub x}, MnO{sub x}, and CeO{sub 2} oxides. The catalyst with Cu/Mn atomic ratio of 1/1 exhibits the best chlorobenzene elimination capability, oxidizing about 95% of the inlet chlorobenzene at 264 °C with CO{sub 2} selectivity higher than 99.5%. The concentration and mobility of the chemically adsorbed oxygen are vital for the effective removal of surface Cl species, which inhibits the dissociation of oxygen molecules and decreases the reducibility of the copper and manganese species. It can be rationally concluded that the superior catalytic performance and durability of the mesoporous CuO-MnO{sub x}-CeO{sub 2} composite

  4. Ytterbium-doped Q-switched fiber laser based upon manganese dioxide (MnOsub>2sub>) saturable absorber.

    Science.gov (United States)

    Hattori, Haroldo T; Khaleque, Abdul; Liu, Liming; Greck, Michael R

    2016-11-10

    Manganese dioxide (MnOsub>2sub>) is an abundant material that is widely used in many devices, such as alkaline batteries. At infrared frequencies, MnOsub>2sub> is lossy and strongly absorbs light. These characteristics make MnOsub>2sub> a potential candidate as a low-cost saturable absorber in Q-switched lasers. In this paper, we examine the performance of MnOsub>2sub> as a saturable absorber in an ytterbium-doped Q-switched fiber laser: we show that it can produce pulses with durations ranging from 300 to 1800 ns.

  5. Organic and inorganic fertilization effects on DTPA-extractable Fe, Cu, Mn and Zn, and their concentration in the edible portion of crops

    OpenAIRE

    Maqueda Porras, Celia; Herencia, Juan F.; Ruiz Porras, J. C.; Hidalgo García, Mª F.

    2011-01-01

    The application of organic composts to soil may affect the availability of micronutrients and their concentration in plants. The present field research study compared soil micronutrient extractability after 5 years of organic fertilization v. conventional inorganic fertilization. Iron (Fe), copper (Cu), manganese (Mn) and zinc (Zn) were extracted from soil using diethylene triamine pentaacetic acid (DTPA) and the data obtained were compared with the concentration of these micronutrients in th...

  6. Oximato bridged Rh$^{\\text{III}}_2$MII and RhIIIMI species (MII = Mn, Co, Ni; MI = Cu, Ag)

    Indian Academy of Sciences (India)

    Indranil Bhattacharyya; Sanjib Ganguly; Bikash Kumar Panda; Animesh Chakravorty

    2008-01-01

    The reaction of [RhCl2(HPhL)(PhL)] with MII(ClO4)2.6H2O in presence of alkali has furnished trinuclear [RhCl2(PhL)2]2M(H2O)2.H2O (HPhL is phenylazobenzaldoxime; M = Mn, Co, Ni). A similar reaction with MI(PPh3)2NO3 yielded binuclear [RhCl2(PhL)2]M(PPh3)2 (M = Cu, Ag). In these molecules the oximato group acts as a bridge between RhIII (bonded at N) and MII or MI (bonded at O). In structurally characterized [RhIIICl2(PhL)2]2Mn(H2O)2.H2O the centrosymmetric distorted octahedral MnO6 coordination sphere is spanned by four oximato oxygen atoms and two water molecules lying in trans position. In the lattice the neighbouring molecules are held together by H2O$\\cdots$H2O$\\cdots$H2O hydrogen bonds generating infinite zigzag chains. The manganese atoms lie parallel to the C-axis, the shortest Mn…Mn distance being 7.992 Å. Magnetic exchange interactions if any are small as seen in room temperature magnetic moments. The manganese system displays a strong EPR signal near = 2.00. In the complex [RhCl2(PhL)2]Cu(PPh3)2 the copper atom is coordinated to two oximato oxygen atoms and the two phosphorus atoms in a distorted tetrahedral geometry. The softness of the phosphine ligand is believed to sustain the stable coordination of hard oximato oxygen to soft CuI. The coordination sphere of the RhIII atom in both the complexes is uniformly trans-RhN4Cl2.

  7. Effects of Manganese Content on Solidification Structures, Thermal Properties, and Phase Transformation Characteristics in Fe-Mn-C Steels

    Science.gov (United States)

    Yang, Jian; Wang, Yu-Nan; Ruan, Xiao-Ming; Wang, Rui-Zhi; Zhu, Kai; Fan, Zheng-Jie; Wang, Ying-Chun; Li, Cheng-Bin; Jiang, Xiao-Fang

    2015-02-01

    The solidification structures and the thermal properties of Fe-Mn-C steel ingots containing different manganese contents have been investigated and the phase transformation characteristics have been revealed by Thermo-Calc to assist development of the continuous casting technology of Fe-Mn-C steels. The results show that the thermal conductivity of the 0Mn steel is higher than that of the 3Mn steel. The thermal conductivity of the 6Mn steel is the lowest in the three kinds of steels below 1023 K (750 °C) and the highest above 1173 K (900 °C). The 0Mn steel has the highest value of the proportion of equiaxed grain zone area in the three kinds of steels, whereas the 3Mn steel has the lowest value of it in the steels. Manganese has the effect of promoting the coarsening of grains. The microstructure is martensite and a little retained austenite (3.8 mass pct) in the 6Mn steel, whereas the microstructure is bainite in the 3Mn steel. The 0Mn steel is characterized by ferrite and pearlite. The mean thermal expansion coefficients of the steels are in the range from 1.0 × 10-5 to 1.6 × 10-5 K-1, and the determinations of mold tapers of the 6Mn and 3Mn steels can refer to low-carbon steel. Using RA steel is 873 K to 1073 K (600 °C to 800 °C), whereas those of the 3Mn steel and the 0Mn steel are 873 K to 1123 K (600 °C to 850 °C) and 873 K to 1173 K (600 °C to 900 °C), respectively. In the 6Mn and 3Mn steels, the deformation-induced ferrite (DIF) forms in sufficient quantities cause the recovery of the ductility at the low temperature end. However, since low strains are present when straightening, sufficient quantities of DIF cannot be formed. Thus, the ductility of the 6Mn and 3Mn steels cannot be improved during the continuous casting process. Manganese has the effect of enlarging the austenite phase region and reducing the δ-ferrite phase region and α-ferrite phase region.

  8. Protective effects of ebselen (Ebs) and para-aminosalicylic acid (PAS) against manganese (Mn)-induced neurotoxicity

    Energy Technology Data Exchange (ETDEWEB)

    Marreilha dos Santos, A.P., E-mail: apsantos@ff.ul.pt [I-Med.UL, Department of Toxicology and Food Sciences, Faculty of Pharmacy, University of Lisbon, Lisbon (Portugal); Lucas, Rui L.; Andrade, Vanda; Mateus, M. Luísa [I-Med.UL, Department of Toxicology and Food Sciences, Faculty of Pharmacy, University of Lisbon, Lisbon (Portugal); Milatovic, Dejan; Aschner, Michael [Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN 37232 (United States); Batoreu, M. Camila [I-Med.UL, Department of Toxicology and Food Sciences, Faculty of Pharmacy, University of Lisbon, Lisbon (Portugal)

    2012-02-01

    Chronic, excessive exposure to manganese (Mn) may induce neurotoxicity and cause an irreversible brain disease, referred to as manganism. Efficacious therapies for the treatment of Mn are lacking, mandating the development of new interventions. The purpose of the present study was to investigate the efficacy of ebselen (Ebs) and para-aminosalicylic acid (PAS) in attenuating the neurotoxic effects of Mn in an in vivo rat model. Exposure biomarkers, inflammatory and oxidative stress biomarkers, as well as behavioral parameters were evaluated. Co-treatment with Mn plus Ebs or Mn plus PAS caused a significant decrease in blood and brain Mn concentrations (compared to rats treated with Mn alone), concomitant with reduced brain E{sub 2} prostaglandin (PGE{sub 2}) and enhanced brain glutathione (GSH) levels, decreased serum prolactin (PRL) levels, and increased ambulation and rearing activities. Taken together, these results establish that both PAS and Ebs are efficacious in reducing Mn body burden, neuroinflammation, oxidative stress and locomotor activity impairments in a rat model of Mn-induced toxicity. -- Highlights: ► The manuscript is unique in its approach to the neurotoxicity of Mn. ► The manuscript incorporates molecular, cellular and functional (behavioral) analyses. ► Both PAS and Ebs are effective in restoring Mn behavioral function. ► Both PAS and Ebs are effective in reducing Mn-induced oxidative stress. ► Both PAS and Ebs led to a decrease in Mn-induced neuro-inflammation.

  9. Distributions of dissolved trace metals (Cd, Cu, Mn, Pb, Ag in the southeastern Atlantic and the Southern Ocean

    Directory of Open Access Journals (Sweden)

    M. Boye

    2012-03-01

    Full Text Available Comprehensive synoptic datasets (surface water down to 4000 m of dissolved cadmium (Cd, copper (Cu, manganese (Mn, lead (Pb and silver (Ag are presented along a section between 34° S and 57° S in the southeastern Atlantic Ocean and the Southern Ocean to the south off South Africa. The vertical distributions of Cu, Ag, and of Cd display nutrient-like profiles similar to silicic acid, and phosphate, respectively. The distribution of Mn shows a subsurface maximum in the oxygen minimum zone, whereas Pb concentrations are rather invariable with depth. Dry deposition of aerosols is thought to be an important source of Pb to surface waters close to South Africa, and dry deposition and snowfall may have been significant sources of Cu and Mn at the higher latitudes. Furthermore, the advection of water-masses enriched in trace metals following contact with continental margins appeared to be an important source of trace elements to the surface, intermediate and deep waters in the southeastern Atlantic Ocean and the Antarctic Circumpolar Current. Hydrothermal inputs appeared to have formed a source of trace metals to the deep waters over the Bouvet Triple Junction ridge crest, as suggested by relatively enhanced dissolved Mn concentrations. The biological utilization of Cu and Ag was proportional to that of silicic acid across the section, suggesting that diatoms formed an important control over the removal of Cu and Ag from surface waters. However uptake by dino- and nano-flagelattes may have influenced the distribution of Cu and Ag in the surface waters of the subtropical Atlantic domain. Cadmium correlated strongly with phosphate (P, yielding lower Cd/P ratios in the subtropical surface waters where phosphate concentrations were below 0.95 μM. The greater depletion of Cd relative to P observed in the Weddell Gyre compared to the Antarctic Circumpolar Current could be due to increase Cd-uptake induced by iron-limiting conditions in these High

  10. The influence of Mn-doped CeO2 on the activity of CuO/CeO2 in CO oxidation and NO + CO model reaction

    Science.gov (United States)

    Deng, Changshun; Huang, Qingqing; Zhu, Xiying; Hu, Qun; Su, Wenli; Qian, Junning; Dong, Lihui; Li, Bin; Fan, Minguang; Liang, Caiyuan

    2016-12-01

    This work is mainly focused on the investigation of the influence of Mn-doped CeO2 supported by CuO on the physicochemical and catalytic properties for CO oxidation and NO + CO model reaction. The obtained samples were characterized using N2-physisorption (BET), XRD, LRS, TEM, EDS-Mapping, ICP-AES, XPS, H2-TPR, O2-TPD, in situ DRIFTS, CO oxidation, and NO + CO model reaction. The results imply that appropriate doping MnOx into the lattice of CeO2 will cause an obvious change in the properties of the catalyst and the Cu/CeMn-10: 1 catalyst shows the largest specific surface area, the most uniformity of structure, and the most extent of lattice expansion. A few addition of MnOx is more conducive to the generation of low valence manganese ion in the process of calcination, which may contribute to the synergetic introduction. This further results in more Cu+ due to the shifting of redox equilibrium (Cu2+ + Ce3+ ↔ Cu+ + Ce4+) to right, as well as more oxygen vacancies. Moreover, the capability of Cu/CeMn-10: 1 on desorb/transform/decompose of the adsorbed NO species is more effective than that of Cu/CeO2. The results of catalytic performance show that Cu+/Cu0 species play a key role, and the activity is mainly related to the specific surface area, the content of Cu+ and Ce3+, the reduction, desorption capability of chemisorbed O2- (and/or O-) species as well as adsorption behaviors of these catalysts for CO oxidation and NO + CO reaction. Finally, possible reaction mechanisms are tentatively proposed to understand the reactions.

  11. Giant orthorhombic distortions by Cu+ in ferrimagnetic spinel Mn334

    Science.gov (United States)

    Chung, Jae-Ho; Lee, Kee Hwan; Chang, Hun; Hwang, In Yong; Kang, Hyun Wook; Kim, Su Jae; Lee, Seongsu

    2015-03-01

    Mn3O4 is a tetragonal (c > a) spinel that exhibits noncollinear Yafet-Kittel ferrimagnetic ordering at low temperatures. We report large orthorhombic distortions in its ferrimagnetic phase stabilized by a few percent of Cu doping. The orthorhombic strains of the ferrimagnetic phases increased linearly to the doping and reached up to ɛ ~ 8 . 2 ×10-3 for x = 0.19, which is three times larger than the saturated value under external magnetic fields. For high doping (xagt 0 . 17), the distortions first appeared in the paramagnetic phases and underwent further enhancement simultaneously with the onset of the noncollinear ferrimagnetic ordering. We present the rich magnetostructural phase diagram of CuxMn3-xO4, and argue that the diluted t2 orbital degeneracy of Cu2+ under tetrahedral crystal field breaks the global symmetry and triggers the orthorhombic instability inherent in Mn3O4. This work was supported by the National Research Foundation of Korea through the ARCNEX (NRF-2011-0031933).

  12. Manganese superoxide dismutase, but not CuZn superoxide dismutase, is highly expressed in the granulomas of pulmonary sarcoidosis and extrinsic allergic alveolitis.

    Science.gov (United States)

    Lakari, E; Pääkkö, P; Kinnula, V L

    1998-08-01

    The role of antioxidant defense mechanisms in the pathogenesis of granulomatous human lung diseases remains open to investigation. In this study we investigated the immunoreactivity of two important superoxide radical scavenging intracellular antioxidant enzymes, manganese superoxide dismutase (MnSOD) and copperzinc superoxide dismutase (CuZnSOD), in pulmonary sarcoidosis and extrinsic allergic alveolitis. In histologically normal lung MnSOD was variable but mostly positive in the cells of bronchial epithelium, alveolar epithelium especially in type II pneumocytes, and alveolar macrophages. Copperzinc SOD showed positive immunoreactivity most markedly in the bronchial epithelium. The biopsies of 22 patients with pulmonary sarcoidosis and 10 with extrinsic allergic alveolitis indicated that MnSOD was highly stained in the granulomas of both diseases, with 60 to 100% of the granulomas showing intensive immunoreactivity. Western blots conducted on the cell samples of bronchoalveolar lavage (BAL) fluid revealed significantly higher amounts of MnSOD in sarcoidosis and extrinsic allergic alveolitis than in the controls. Immunohistochemistry on the cells obtained from BAL fluid showed positive immunoreactivity of MnSOD in the macrophages but not in the lymphocytes. In contrast, copperzinc SOD was not induced in either of these diseases. We conclude that MnSOD is highly expressed in the granulomas of pulmonary sarcoidosis and extrinsic allergic alveolitis, and variable but mostly positive in alveolar macrophages, possibly owing to cytokine mediated induction during the granuloma formation.

  13. HC-SCR: NOx Reduction using Mn and Cu Catalysts Impregnated in Coconut and Palm Kernel Shell Activated Carbon

    Directory of Open Access Journals (Sweden)

    Barrabas Sherra Bellina

    2017-01-01

    Full Text Available The characteristics of catalysts impregnated in coconut shell (CS and palm kernel shell (PKS activated carbon were determined as potential precursors of catalysts used in a flue gas denitrification system at low temperature. In this study, Manganese (Mn and Copper (Cu with metal loading of 8% were impregnated in the activated carbon (AC before undergoing low temperature calcination process. The morphological properties of samples was analysed using Scanning Electron Microscopy (SEM and Brunauer, Emmett and Teller (BET was used to determine the surface area and pore size of samples. The exhaust gas from a diesel engine at a constant flow rate of 4L/min was passed through in a fixed-bed catalytic reactor containing the catalyst, and the concentration of NOx was measured for temperatures ranging from 150°C to 250°C. It was found that the CS catalysts (CS-Mn and CS-Cu and PKS catalysts (PKS-Mn and PKS-Cu have the potential to reduce NOx concentration, and results showed that the metal loading of 8% resulted NOx reduction ranging from ~48% to 64%.

  14. Structural, dielectric and gas sensing behavior of Mn substituted spinel MFe{sub 2}O{sub 4} (M=Zn, Cu, Ni, and Co) ferrite nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Ranjith Kumar, E., E-mail: ranjueaswar@gmail.com [Department of Physics, Dr. NGP Institute of Technology, Coimbatore 641048, Tamil Nadu (India); Siva Prasada Reddy, P.; Sarala Devi, G. [Inorganic and Physical Chemistry Division, Indian Institute Chemical Technology, Hyderabad 500607 (India); Sathiyaraj, S. [Department of Chemistry, Dr. NGP Institute of Technology, Coimbatore 641048, Tamil Nadu (India)

    2016-01-15

    Spinel ferrite (MnZnFe{sub 2}O{sub 4}, MnCuFe{sub 2}O{sub 4}, MnNiFe{sub 2}O{sub 4} and MnCoFe{sub 2}O{sub 4}) nanoparticles have been prepared by evaporation method. The annealing temperature plays an important role on changing particle size of the spinel ferrite nanoparticles was found out by X-ray diffraction and transmission electron microscopy. The role of manganese substitution in the spinel ferrite nanoparticles were also analyzed for different annealing temperature. The substitution of Mn also creates a vital change in dielectric properties have been measured in the frequency range of 100 kHz to 5 MHz. These spinel ferrites are decomposed to α-Fe{sub 2}O{sub 3} after annealing above 550 °C in air. Through the characterization of the prepared powder, the effect of annealing temperature, chemical composition and preparation technique on the microstructure, particle size and dielectric properties of the Mn substituted spinel ferrite nanoparticles are discussed. Furthermore, Conductance response of Mn substituted MFe{sub 2}O{sub 4} ferrite nanoparticles were measured by exposing the materials to reducing gas like liquefied petroleum gas (LPG). - Highlights: • The egg white support to achieve sample with shorter reaction time. • Manganese plays a significant role in sensor response. • Nature of the ferrites was affected with increasing annealing temperature.

  15. Teores de Fe, Mn, Zn, Cu, Ni E Co em solos de referência de Pernambuco Concentrations of Fe, Mn, Zn, Cu, Ni and Co in benchmark soils of Pernambuco, Brazil

    Directory of Open Access Journals (Sweden)

    Caroline Miranda Biondi

    2011-06-01

    metals are evidentially essentials (Fe, Mn, Cu, Zn, and Ni and beneficial (Co for plants. In this context, the objective was to determine the natural contents of the metals iron (Fe, manganese (Mn, zinc (Zn, nickel (Ni, copper (Cu and cobalt (Co in benchmark soils of Pernambuco. Soil samples were collected in the three physiographic regions of the state (Zona da Mata, Agreste and Sertão, in the first two horizons of the 35 benchmark soils of the state of Pernambuco. Sample digestion was based on the method 3051A (USEPA, 1998 and determined by ICP-OES. Significant correlations were found between these metals and those with the clay soil fraction in both horizons, indicating the general association of most metals to the most clayey soils. The Fe, Mn, Zn, Cu, Ni, and Co contents of most soils were lower than in soils from other regions of the country and more mafic lithology, which confirms that the contents of these elements are more directly related to iron-magnesium minerals. The results indicate a low capacity of the soils of Pernambuco to release Cu, Co and Ni to plants, while deficiencies of Zn, Fe and Mn are less likely. The natural contents of Fe, Mn, Zn, Cu, Ni, and Co determined here can be used as a basis for defining the Quality Reference Values for soils of Pernambuco, as stipulated by the Brazilian legislation.

  16. Synthesis and magnetic structure of the layered manganese oxide selenide Sr2MnO2Ag1.5Se2

    Science.gov (United States)

    Blandy, Jack N.; Boskovic, Jelena C.; Clarke, Simon J.

    2017-01-01

    The synthesis of a high-purity sample of the layered oxide selenide Sr2MnO2Ag1.5Se2 is reported. At ambient temperature it crystallises in the space group I4/mmm with two formula units in the unit cell and lattice parameters a=4.08771(1) Å, c=19.13087(8) Å. The compound displays mixed-valent manganese in a formal oxidation state close to +2.5 and powder neutron diffraction measurements reveal that below the Néel temperature of 63(1) K this results in an antiferromagnetic structure which may be described as A-type, modelled in the magnetic space group PI4/mnc (128.410 in the Belov, Neronova and Smirnova (BNS) scheme) in which localised Mn moments of 3.99(2) μB are arranged in ferromagnetic layers which are coupled antiferromagnetically. In contrast to the isostructural compound Sr2MnO2Cu1.5S2, Sr2MnO2Ag1.5Se2 does not display long range ordering of coinage metal ions and vacancies, nor may significant amounts of the coinage metal readily be deintercalated using soft chemical methods.

  17. Grotrian diagrams for highly ionized Manganese, Mn VI through Mn XXV

    OpenAIRE

    白井 稔三; Sugar, J.; Wiese, W. L.

    1997-01-01

    高電離マンガン、Mn VI-Mn XXVの1,535本のスペクトル線をエネルギー準位と遷移の特徴を視覚化するグロトリアン図にまとめた。Bashkin and Stoner[North-Holland,Amsterdam,1975]による通常のグロトリアン図の表示法では、それぞれの遷移を表す線の密度が高くなり過ぎ、全ての遷移を表示できないことがしばしばある。我々のグロトンアン図でも遷移を線で表すが、しかし、遷移の上位準位を必要なだけ繰り返す方法に変更した。その結果、遷移線の高密度化が回避でき、多重項等全ての遷移を表すことができた。...

  18. Elastocaloric effect in CuAlZn and CuAlMn shape memory alloys under compression.

    Science.gov (United States)

    Qian, Suxin; Geng, Yunlong; Wang, Yi; Pillsbury, Thomas E; Hada, Yoshiharu; Yamaguchi, Yuki; Fujimoto, Kenjiro; Hwang, Yunho; Radermacher, Reinhard; Cui, Jun; Yuki, Yoji; Toyotake, Koutaro; Takeuchi, Ichiro

    2016-08-13

    This paper reports the elastocaloric effect of two Cu-based shape memory alloys: Cu68Al16Zn16 (CuAlZn) and Cu73Al15Mn12 (CuAlMn), under compression at ambient temperature. The compression tests were conducted at two different rates to approach isothermal and adiabatic conditions. Upon unloading at a strain rate of 0.1 s(-1) (adiabatic condition) from 4% strain, the highest adiabatic temperature changes (ΔTad) of 4.0 K for CuAlZn and 3.9 K for CuAlMn were obtained. The maximum stress and hysteresis at each strain were compared. The stress at the maximum recoverable strain of 4.0% for CuAlMn was 120 MPa, which is 70% smaller than that of CuAlZn. A smaller hysteresis for the CuAlMn alloy was also obtained, about 70% less compared with the CuAlZn alloy. The latent heat, determined by differential scanning calorimetry, was 4.3 J g(-1) for the CuAlZn alloy and 5.0 J g(-1) for the CuAlMn alloy. Potential coefficients of performance (COPmat) for these two alloys were calculated based on their physical properties of measured latent heat and hysteresis, and a COPmat of approximately 13.3 for CuAlMn was obtained.This article is part of the themed issue 'Taking the temperature of phase transitions in cool materials'.

  19. Induced effects of Cu underlayer on (111) orientation of Fe50 Mn50 thin films

    Institute of Scientific and Technical Information of China (English)

    WANG Lei; WANG Feng-ping; LIU Huan-ping; WU Ping; QIU Hong; PAN Li-qing

    2005-01-01

    Effects of Cu underlayer on the structure of Fe50 Mn50 films were studied. Samples with a structure of Fe50 Mn50 (200 nm)/Cu(tCu) were prepared by magnetron sputtering on thermally oxidized silicon substrates at room temperature. The thickness of Cu underlayer varied from 0 to 60 nm in the intervals of 10 nm. High-vacuum annealing treatments, at different temperatures of 200, 300 and 400 ℃ for 1 h, respectively, on the Fe50 Mn50 (200 nm)/Cu(20 nm) thin films were performed. The surface morphologies and textures of the samples were measured by field emission scan electronic microscope (FE-SEM) and X-ray diffraction(XRD). Energy dispersive X-ray spectroscopy (EDX) and Auger electron spectroscopy(AES) were used to analyze the compositional distribution. It is found that Cu underlayer has an obvious induce effect on (111) orientation of Fe50 Mn50 thin films. The induce effects of Cu on (111) orientation of Fe50 Mn50 changed with the increase of Cu layer thickness and the best effect was obtained at the Cu layer thickness of 20 nm. High-vacuum annealing treatments cause the migration of Mn atoms towards surface of the film and interface between Cu layer and substrate. With the increasing annealing temperature, migration of Mn atoms is more obvious, which leads to a Fe-riched Fe-Mn alloy film.

  20. Physicochemical factors for affecting the efficiency of Arthrobacter chlorophenolicus MN1409 on manganese oxidation%理化因素对锰细菌Arthrobacter chlorophenolicus MN1409氧化Mn2+的影响

    Institute of Scientific and Technical Information of China (English)

    冯福鑫; 王芳; 许旭萍

    2012-01-01

    Arthrobacter chlorophenolicus MN1409是1株分离自锰矿样品的高效锰氧化细菌.为了建立该菌株氧化Mn2+的适宜条件,研究了接种量、装液量、摇床转速、温度、pH值、Fe2+初始质量浓度和Mn2+初始质量浓度等理化因素对其锰氧化效率的影响.结果表明,接种量、装液量、转速和Mn2+初始质量浓度在一定范围内变化对锰氧化率影响不大;而温度、pH值和Fe2+初始质量浓度变化对锰氧化率有较大影响.当接种量为4%,装液量为60mL,温度为25℃,摇床转速为100r/min,pH值为7,且有一定的Fe2+存在时,Arthrobacter chlorophenolicus MN1409对锰的氧化效率最高.%The physicochemical factors for affecting the manganese oxidation efficiency of an manganese oxidizing bacteria named Arthrobacter chlorophennlicus MN1409 which was isolated from manganese ore sample were studied. The identified factors include inoculum volume, liquid volume, temperature, shaking speed, pH as well as the concentration of Fe2+ and Mn2+ . The results showed that there was no significant effect on the biological manganese oxidation rate and chemical manganese oxidation rate during 2% - 10% inoculum volumes. 4% inoculum volume was the optimum condition according to its highest total manganese oxidation rate. Similarly, biological and chemical manganese oxidation rale have no significant difference for the liquid volume ranging from 50 mL to 100 mL in 250 mL triangular flask , the highest total manganese oxidation rate occurred in 60 mL liquid volume. Nevertheless, temperature showed an positive effect on manganese oxidation rate. By increasing the temperature from 15 ℃ to 35 ℃, highest biological and chemical manganese oxidation rate could be reached at 25 ℃ and 35 ℃ , respectively, plus the total oxidation rate could achieved 81.52% as well in 35 ℃ . In addition, the effect of shaker speed on manganese oxidation efficiency (MOE) showed that the oxidation rates were similar for

  1. Manganese nodules

    Science.gov (United States)

    Hein, James R.; Harff, Jan; Petersen, Sven; Thiede, Jorn

    2016-01-01

    The existence of manganese (Mn) nodules (Figure 1) has been known since the late 1800s when they were collected during the Challenger expedition of 1873–1876. However, it was not until after WWII that nodules were further studied in detail for their ability to adsorb metals from seawater. Many of the early studies did not distinguish Mn nodules from Mn crusts. Economic interest in Mn nodules began in the late 1950s and early 1960s when John Mero finished his Ph.D. thesis on this subject, which was published in the journal Economic Geology (Mero, 1962) and later as a book (Mero, 1965). By the mid-1970s, large consortia had formed to search for and mine Mn nodules that occur between the Clarion and Clipperton fracture zones (CCZ) in the NE Pacific (Figure 2). This is still the area considered of greatest economic potential in the global ocean because of high nickel (Ni), copper (Cu), and Mn contents and the dense distribution of nodules in the area. While the mining of nodules was fully expected to begin in the late 1970s or early 1980s, this never occurred due to a downturn in the price of metals on the global market. Since then, many research cruises have been undertaken to study the CCZ nodules, and now 15 contracts for exploration sites have been given or are pending by the International Seabed Authority (ISA). Many books and science journal articles have been published summarizing the early work (e.g., Baturin, 1988; Halbach et al., 1988), and research has continued to the present day (e.g., ISA, 1999; ISA, 2010). Although the initial attraction for nodules was their high Ni, Cu, and Mn contents, subsequent work has shown that nodules host large quantities of other critical metals needed for high-tech, green-tech, and energy applications (Hein et al., 2013; Hein and Koschinsky, 2014).

  2. Diffusion barrier property of MnSi{sub x}O{sub y} layer formed by chemical vapor deposition for Cu advanced interconnect application

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Mai Phuong, E-mail: nmphuong46@gmail.com; Sutou, Yuji; Koike, Junichi, E-mail: koikej@material.tohoku.ac.jp

    2015-04-01

    An amorphous manganese oxide layers formed by chemical vapor deposition have been studied as a copper diffusion barrier. The thermal stability of the barrier layer was assessed by annealing Cu/MnSi{sub x}O{sub y}/SiO{sub 2}/Si samples at 400 °C for various times up to 10 h. Transmission electron microscopy, energy-dispersive X-ray spectroscopy (EDX), secondary ion mass spectroscopy (SIMS), capacitance-voltage and current–voltage measurements were performed. Failure of the barrier property is marked by observing the copper peak appearing in EDX and SIMS spectra data from the SiO{sub 2} region. Amorphous MnSi{sub x}O{sub y} barrier with a thickness of 1.2 nm has failed in preventing Cu diffusion into SiO{sub 2} substrate after anneal at 400°C in vacuum for 1h, as proven by the presence of Cu in the dielectric (SiO{sub 2}) layer. However, the amorphous MnSi{sub x}O{sub y} with the thickness of 2.0 nm barrier was thermally stable and could prevent Cu from inter-diffusion to the SiO{sub 2} substrate after annealing at 400 °C even up to 10 h. - Highlights: • Amorphous manganese silicate layer has been studied as a copper diffusion barrier. • The 1.2 nm-thick Mn oxide layer is too thin to become a diffusion barrier. • Good thermal stability of 2.0 nm-thick manganese silicate layer.

  3. Low frequency sonochemical synthesis of nanoporous amorphous manganese dioxide (MnO{sub 2}) and adsorption of remazol reactive dye

    Energy Technology Data Exchange (ETDEWEB)

    Hasan, Siti Zubaidah; Yusop, Muhammad Rahimi; Othman, Mohamed Rozali, E-mail: rozali@ukm.edu.my [School of Chemical Sciences and Food Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor Darul Ehsan (Malaysia)

    2015-09-25

    Nanoporous amorphous-MnO{sub 2} was synthesized by sonochemical process (sonication) on the solid manganese (II) acetate tetrahydrate (Mn(CH{sub 3}COO){sub 2}.4H{sub 2}O) in 0.1 M KMnO{sub 4}. The product was characterized by X-ray diffraction (XRD), morphology of the material was scanned by Field Emission Scanning Electron Microscopy (FE-SEM) and absorptions of MnO{sub 2} bonding was characterized by Fourier Transform Infra-Red Spectrometer (FT-IR). Remazol reactive dye or Red 3BS, was used in the adsorption study using nanoporous amorphous-MnO{sub 2}. In batch experiment, 10 ppm of Remazol reactive dye was used and experiment was carried out at room temperature. Adsorption of Remazol dye on 0.2g synthesized nanoporous amorphous-MnO{sub 2} showed 99 – 100% decolorization.

  4. Structure-activity relationship of CuO/MnO2 catalysts in CO oxidation

    Science.gov (United States)

    Qian, Kun; Qian, Zhaoxia; Hua, Qing; Jiang, Zhiquan; Huang, Weixin

    2013-05-01

    A series of CuO/MnO2 catalysts with different CuO loadings were synthesized by the incipient wetness impregnation method. The catalysts were characterized by N2 adsorption-desorption isotherms, powder X-ray diffraction, X-ray photoelectron spectroscopy, H2-temperature programmed reduction, CO-temperature programmed reduction and scanning electron microscope. The CuO/MnO2 catalysts with CuO loading of 1-40% exhibit almost the same catalytic performance toward CO oxidation while those with higher CuO loadings exhibit a much poorer catalytic activity. The structural characterization results demonstrate that the CuO-MnO2 interface is the active site for CO oxidation in CuO/MnO2 catalysts and CO oxidation over CuO/MnO2 probably follows the interfacial reaction mechanism in which CO chemisorbed on CuO reacts with oxygen species on MnO2 at the CuO-MnO2 interface.

  5. A manganese superoxide dismutase (MnSOD) from ark shell, Scapharca broughtonii: Molecular characterization, expression and immune activity analysis.

    Science.gov (United States)

    Zheng, Libing; Wu, Biao; Liu, Zhihong; Tian, Jiteng; Yu, Tao; Zhou, Liqing; Sun, Xiujun; Yang, Aiguo

    2015-08-01

    Manganese superoxide dismutase (MnSOD) is one of the key members of the antioxidant defense enzyme family, however, data regarding to the immune function of MnSOD in mollusks still remain limited now. In this study, a full-length MnSOD cDNA was identified by rapid amplification of cDNA ends (RACE) method from cDNA library of ark shell Scapharca broughtonii (termed SbMnSOD). The cDNA contained an open reading frame (ORF) of 696 bp which encoded a polypeptide of 232 amino acids, a 5'-UTR with length of 32 bp and a 3'-UTR of 275 bp. Four putative amino acid residues (His-57, His-105, Asp-190 and His-194) responsible for manganese coordination were located in the most highly conserved regions of SbMnSOD and the signature sequence (DVWEHAYY) also existed in SbMnSOD. The deduced amino acid sequence of SbMnSOD shared high homology to MnSOD from other species. All those data revealed that the SbMnSOD was a novel member of the MnSOD family. The mRNA expression profiles of SbMnSOD in tissues of foot, gill, mantle, adductor muscle, hemocytes and hepatopancreas analyzed by quantitative real-time PCR (qRT-PCR) suggested the mRNA transcripts of SbMnSOD distributed in all the examined tissues. Importantly, Vibrio anguillarum challenge resulted in the increased expression of SbMnSOD mRNA with a regular change trend in all examined tissues, indicating SbMnSOD actively participated in the immune response process. What's more, further analysis on the antibacterial activity of the recombinant SbMnSOD showed that the fusion protein could remarkably inhibit growth of both Gram-positive and Gram-negative bacteria. The present results clearly suggested that SbMnSOD was an acute phase protein involved in the immune reaction in S. broughtonii.

  6. Crednerite-CuMnO{sub 2} thin films prepared using atmospheric pressure plasma annealing

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Hong-Ying, E-mail: hychen@cc.kuas.edu.tw [Department of Chemical and Materials Engineering, National Kaohsiung University of Applied Sciences, 415 Chiken Kuang Road, Kaohsiung 807, Taiwan, ROC (China); Lin, Yu-Chang [Department of Chemical and Materials Engineering, National Kaohsiung University of Applied Sciences, 415 Chiken Kuang Road, Kaohsiung 807, Taiwan, ROC (China); Lee, Jiann-Shing [Department of Applied Physics, National Pingtung University, 4-18 Minsheng Road, Pingtung City 900, Taiwan, ROC (China)

    2015-05-30

    Highlights: • Crednerite-CuMnO{sub 2} thin films were formed at atmospheric pressure plasma with N{sub 2}–(5–10)%O{sub 2}. • The binding energy of Cu-2p spectrum of the crednerite-CuMnO{sub 2} thin films was 932.3 eV (Cu{sup +}). • The binding energies of Mn-3p spectrum were 48.1 ± 0.2 eV (Mn{sup 3+}) and 50.0 ± 0.2 eV (Mn{sup 4+}). • The cation distribution in the crednerite-CuMnO{sub 2} thin films was Cu{sub 1.0}{sup +}(Mn{sub 0.6}{sup 3+}Mn{sub 0.4}{sup 4+})O{sub 2}. • The electrical conductivity of CuMnO{sub 2} thin films was (2.61–2.65) × 10{sup 4} Ω cm. - Abstract: This study reports the preparation of crednerite-CuMnO{sub 2} thin films using atmospheric pressure plasma annealing. The pristine thin films were deposited onto a quartz substrate using the sol–gel process. The specimens were then annealed using atmospheric pressure plasma at N{sub 2}–(0–20%)O{sub 2} for 20 min. Crednerite-CuMnO{sub 2} thin films were obtained using atmospheric pressure plasma annealing at N{sub 2}–5%O{sub 2} and N{sub 2}–10%O{sub 2}. The lattice parameters of the thin films were a = 0.5574–0.5580 nm, b = 0.2874–0.2879 nm, c = 0.5878–0.5881 nm, and β = 104.15–104.25°, which agree well with previous reports. The Raman shifts of the crednerite-CuMnO{sub 2} thin films were 688 ± 2 cm{sup −1}, 381 ± 2 cm{sup −1}, and 314 ± 2 cm{sup −1}. The binding energy of Cu-2p spectrum of the crednerite-CuMnO{sub 2} thin films was 932.3 ± 0.2 eV representing the Cu{sup +} in the thin films. The binding energies of Mn-3p spectrum were 48.1 ± 0.2 eV (Mn{sup 3+}) and 50.0 ± 0.2 eV (Mn{sup 4+}). Furthermore, the cation distribution in the thin films was Cu{sup +}{sub 1.0}(Mn{sup 3+}{sub 0.6}Mn{sup 4+}{sub 0.4})O{sub 2} from the X-ray photoelectron spectroscopy measurement. When the crednerite-CuMnO{sub 2} phase was formed, the surface morphology exhibited a compact/dense granular morphology. The optical bandgap of the crednerite-CuMnO{sub 2} thin

  7. Preparation of MnO2and calcium silicate hydrate from electrolytic manganese residue and evaluation of adsorption properties

    Institute of Scientific and Technical Information of China (English)

    李昌新; 钟宏; 王帅; 薛建荣; 武芳芳; 张振宇

    2015-01-01

    Electrolytic manganese residue (EMR), a high volume byproduct resulting from the electrolytic manganese industry, was used as a cheap and abundant chemical source for preparing MnO2 and EMR-made calcium silicate hydrate (EMR-CSH). The MnO2 is successfully synthesized from the metal cations extracted from EMR, which can effectively recycle the manganese in the EMR. By the combination of XRD, SEM and EDX analysis, the as-prepared MnO2 is found to exhibit a single-phase with the purity of 90.3%. Furthermore, EMR-CSH is synthesized from EMR via hydrothermal method. Based on the detailed analyses using XRD, FT-IR, FE-SEM, EDX and BET surface area measurement, the product synthesized under the optimum conditions (pH 12.0 and 100 °C) is identified to be a calcium silicate hydrate with a specific surface area of 205 m2/g incorporating the slag-derived metals (Al and Mg) in its structure. The as-synthesized material shows good adsorption properties for removal of Mn2+ and phosphate ions diluted in water, making it a promising candidate for efficient bulk wastewater treatment. This conversion process, which enables us to fabricate two different kinds of valuable materials from EMR at low cost and through convenient preparation steps, is surely beneficial from the viewpoint of the chemical and economical use of EMR.

  8. Application of maghemite nanoparticles as sorbents for the removal of Cu(II), Mn(II) and U(VI) ions from aqueous solution in acid mine drainage conditions

    Science.gov (United States)

    Etale, Anita; Tutu, Hlanganani; Drake, Deanne C.

    2016-06-01

    The adsorptive removal of Cu(II), Mn(II) and U(VI) by maghemite nanoparticles (NPs) was investigated under acid mine drainage (AMD) conditions to assess NP potential for remediating AMD-contaminated water. The effects of time, NP and metal concentration, as well as manganese and sulphate ions were quantified at pH 3. Adsorption of all three ions was rapid, and equilibrium was attained in 5 min or less. 56 % of Cu, 53 % of Mn and 49 % of U were adsorbed. In addition, adsorption efficiencies were enhanced by ≥10 % in the presence of manganese and sulphate ions, although Cu sorption was reduced in 1:2 Cu-to-Mn solutions. Adsorption also increased with pH: 86 % Cu, 62 % Mn and 77 % U were removed from solution at pH 9 and increasing initial metal concentrations. Increasing NP concentrations did not, however, always increase metal removal. Kinetics data were best described by a pseudo-second-order model, implying chemisorption, while isotherm data were better fitted by the Freundlich model. Metal removal by NPs was then tested in AMD-contaminated surface and ground water. Removal efficiencies of up to 46 % for Cu and 54 % for Mn in surface water and 8 % for Cu and 50 % for Mn in ground water were achieved, confirming that maghemite NPs can be applied for the removal of these ions from AMD-contaminated waters. Notably, whereas sulphates may increase adsorption efficiencies, high Mn concentrations in AMD will likely inhibit Cu sorption.

  9. Morphological and interlayer geochemical studies on manganese nodules from the southwestern Carlsberg ridge

    Digital Repository Service at National Institute of Oceanography (India)

    Valsangkar, A.B.; Rajamanickam, G.V.; Karisiddaiah, S.M.; Siddiquie, H.N.

    Mixed facies of manganese nodules from the southwestern Carlberg Ridge have been analysed for Mn, Fe, Ni, Cu, Co and Zn. Seventy one analyses including the averages presented for outer layer, inner layer and near-core material. Morphological studies...

  10. Manganese-modified activated carbon fiber (Mn-ACF): Novel efficient adsorbent for Arsenic

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Zhumei; Yu, Yichang; Pang, Shiyu; Du, Dongyun, E-mail: dydu666@yahoo.com.cn

    2013-11-01

    In this paper, a novel adsorbent, manganese-modified activated carbon fiber (Mn-ACF), was prepared and used for removal of As(V) from aqueous solution. The adsorbent was characterized by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). Adsorption of As(V) onto the as-prepared adsorbent from aqueous solutions was investigated and discussed. The adsorption kinetic data were modeled using the pseudo-first-order and pseudo-second order, respectively. The experimental results indicate that the pseudo-second-order kinetic equation can better describe the adsorption kinetics. Furthermore, adsorption equilibrium data of As(V) on the as-prepared adsorbent were analyzed by Langmuir and Freundlich models, which suggested that the Langmuir model provides a better correlation of the experimental data. The adsorption capacities (q{sub max}) of As(V) on Mn-ACF at various temperatures, determined using the Langmuir equation, are 23.77, 33.23 and 36.53 mg g{sup −1} at 303, 313 and 323 K, respectively. To the best of our knowledge, this adsorption capacity for As(V) is much larger than those reported in literatures (7.50–16.58 mg g{sup −1}). Notably, the q{sub max} increases with increasing temperature, suggesting that adsorption of As(V) on Mn-ACF surface is an endothermic process, which is further confirmed by the calculated thermodynamic parameters including free energy, enthalpy, and entropy of adsorption process. The effect of experimental parameters such as pH and dosage of adsorbent on adsorption of As(V) were also studied. The present work will be useful in purification of groundwater.

  11. Manganese-modified activated carbon fiber (Mn-ACF): Novel efficient adsorbent for Arsenic

    Science.gov (United States)

    Sun, Zhumei; Yu, Yichang; Pang, Shiyu; Du, Dongyun

    2013-11-01

    In this paper, a novel adsorbent, manganese-modified activated carbon fiber (Mn-ACF), was prepared and used for removal of As(V) from aqueous solution. The adsorbent was characterized by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). Adsorption of As(V) onto the as-prepared adsorbent from aqueous solutions was investigated and discussed. The adsorption kinetic data were modeled using the pseudo-first-order and pseudo-second order, respectively. The experimental results indicate that the pseudo-second-order kinetic equation can better describe the adsorption kinetics. Furthermore, adsorption equilibrium data of As(V) on the as-prepared adsorbent were analyzed by Langmuir and Freundlich models, which suggested that the Langmuir model provides a better correlation of the experimental data. The adsorption capacities (qmax) of As(V) on Mn-ACF at various temperatures, determined using the Langmuir equation, are 23.77, 33.23 and 36.53 mg g-1 at 303, 313 and 323 K, respectively. To the best of our knowledge, this adsorption capacity for As(V) is much larger than those reported in literatures (7.50-16.58 mg g-1). Notably, the qmax increases with increasing temperature, suggesting that adsorption of As(V) on Mn-ACF surface is an endothermic process, which is further confirmed by the calculated thermodynamic parameters including free energy, enthalpy, and entropy of adsorption process. The effect of experimental parameters such as pH and dosage of adsorbent on adsorption of As(V) were also studied. The present work will be useful in purification of groundwater.

  12. Microstructure and mechanical properties of nonmagnetic Fe-25Mn-xCu-C steels by super solidus liquid phase sintering

    Science.gov (United States)

    Jia, Shanquan; Xiao, Zhiyu; Wang, Jun; Yang, Shuo; Guan, Hangjian; Zhu, Quanli

    2016-11-01

    In this work, nonmagnetic steels Fe-25Mn-xCu-C were prepared by high manganese pre-alloyed steel powders through powder metallurgy (PM) technique. Four types of steels specimen were created to investigate the microstructure evolving with sintering process, mechanical properties and magnetic properties. The microstructures, fracture surfaces, phase constitutions and mechanical properties of Fe-25Mn-xCu-C were characterized by scanning electron microscopy (SEM), x-ray diffraction (XRD), and tensile strength test. The results showed that super solidus liquid-phase sintering (SLPS) phenomenon was conclusively verified, for the first time, in the Fe-Mn pre-alloyed powders: Liquids generated by SLPS process from pre-alloyed powders could improve the binding condition between the particles and enhance the densification. X-ray diffraction (XRD) experiment and physical property measurement system (PPMS) measurement verified the nonmagnetic properties of steels with single austenite phase. It is confirmed that mechanical properties are intensively influenced by the characteristic and quantity of liquids between the matrix particles. The fracture mechanism of the steel is dominated by intergranular decohesion mode. The preliminary study found this kind of new non-magnetic steel exhibits relatively high density. With the efficiency in fabricating and the non-magnetic property, this work foresees good prospects for application in the steel components manufacturing industry.

  13. High resolution electron energy loss spectroscopy of manganese oxides: Application to Mn{sub 3}O{sub 4} nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Laffont, L., E-mail: Lydia.laffont@ensiacet.fr [Institut Carnot, Laboratoire CIRIMAT (equipe MEMO), CNRS UMR 5085, ENSIACET, 4 allee Emile Monso, BP 74233, 31432 Toulouse cedex 4 (France); Gibot, P. [Laboratoire de Reactivite et Chimie des Solides CNRS UMR 6007, Universite de Picardie Jules Verne, 33 rue Saint Leu, 80039 Amiens cedex 9 (France)

    2010-11-15

    Manganese oxides particularly Mn{sub 3}O{sub 4} Hausmannite are currently used in many industrial applications such as catalysis, magnetism, electrochemistry or air contamination. The downsizing of the particle size of such material permits an improvement of its intrinsic properties and a consequent increase in its performances compared to a classical micron-sized material. Here, we report a novel synthesis of hydrophilic nano-sized Mn{sub 3}O{sub 4}, a bivalent oxide, for which a precise characterization is necessary and for which the determination of the valency proves to be essential. X-ray diffraction (XRD), Transmission Electron Microscopy (TEM) and particularly High Resolution Electron Energy Loss Spectroscopy (HREELS) allow us to perform these measurements on the nanometer scale. Well crystallized 10-20 nm sized Mn{sub 3}O{sub 4} particles with sphere-shaped morphology were thus successfully synthesized. Meticulous EELS investigations allowed the determination of a Mn{sup 3+}/Mn{sup 2+} ratio of 1.5, i.e. slightly lower than the theoretical value of 2 for the bulk Hausmannite manganese oxide. This result emphasizes the presence of vacancies on the tetrahedral sites in the structure of the as-synthesized nanomaterial. - Research Highlights: {yields}Mn{sub 3}O{sub 4} bulk and nano were studied by XRD, TEM and EELS. {yields}XRD and TEM determine the degree of crystallinity and the narrow grain size. {yields}HREELS gave access to the Mn{sup 3+}/Mn{sup 2+} ratio. {yields}Mn{sub 3}O{sub 4} nano have vacancies on the tetrahedral sites.

  14. On the concentration and separation of the trace-elements fe, cu, zn, mn, pb, mo and co : Paper chromatography

    NARCIS (Netherlands)

    Erkelens, P.C. van

    1961-01-01

    Paper chromatographic separations are described by which the minor constituents of biological ashes are separated either into: (Pb) - Mn - Co - (Pb) - Cu - Fe, Mo, Zn; or into: Cu, Mn, Co - Pb - Fe - Mo - Zn.

  15. Relationship between color and composition of Cu-Mn-Zn alloys

    Institute of Scientific and Technical Information of China (English)

    张玉平; 张津徐; 吴建生

    2002-01-01

    The color of Cu-Mn-Zn alloys is quantitatively researched using the CIE L*a*b* color system. The color parameters such as L*, a* and b* are employed to describe the color and are measured by a spectrophotometer. Based on the color data of 46 experimental alloys, a series of formulae are established to correlate color parameters changed with the alloy composition. Therefore, the color of the ternary Cu-Mn-Zn alloys can be calculated and forecast easily. The results show that Mn plays a more important role in the color of Cu-Mn-Zn alloys than Zn does. In particular, the chroma values of ternary Cu-Mn-Zn alloys mainly depend on the Mn content.

  16. Structure and magnetic properties of Mn-doped CuO solids

    Institute of Scientific and Technical Information of China (English)

    FAN Chong-fei; PAN Li-qing; ZHU Hao; QIU Hong-mei; WANG Feng-ping; WU Ping; QIU Hong; ZHANG Yue; J. Q. XIAO

    2005-01-01

    The CuO doped with 5%-20% Mn(molar fraction) solids were sintered from CuO and MnO2 powder at high temperature (1 273 K) for 8 h. X-ray diffraction was used to determine the solid crystallinity and to address the formation of secondary phases. It is found that it is difficult to achieve pure Cu1-xMnxO phase using standard solid phase reaction. However, sintering under a pressure of 27.7 MPa significantly reduces the undesirable second phase CuMn2O4, providing a route to achieve pure Cu1-xMnx O phase. SQUID magnetometry was employed to characterize the magnetic properties. Mn-doped CuO presents ferromagnetic characteristics below 70 K. Electrical transport properties were measured in a current-perpendicular-to-plane(CPP) geometry using the PPMS, which suggests variable-range hopping mechanism.

  17. Biomimetic Decarboxylation of Carboxylic Acids with PhI(OAc)2 Catalyzed by Manganese Porphyrin [Mn(TPP)OAcl

    Institute of Scientific and Technical Information of China (English)

    GHOLAM REZA Karimipour; ROXANA Ahmadpour

    2008-01-01

    Manganese(Ⅲ) meso-tetraphenylporphyrin acetate [Mn(TPP)OAc] served as an effective catalyst for the oxidative decarboxylation of carboxylic acids with (diacetoxyiodo)benzene [Phl(OAc)2] in CH2C12-H2O(95:5,volume ratio),The aryl substituted acetic acids are more reactive than the less electron rich linear carboxylic acids in the presence of catalyst Mn(TPP)OAc,In the former case,the formation of carbonyl products was complete within just a few minutes with >97% selectivities,and no further oxidation of the produced aldehydes was achieved under these catalytic conditions,This method provides a benign procedure owing to the utilization of low toxic(diacetoxyiodo)benzene,biologically relevant manganese porphyrins,and carboxylic acids.

  18. Role of estuarine natural flocculation process in removal of Cu, Mn, Ni, Pb and Zn

    Directory of Open Access Journals (Sweden)

    S. Hassani

    2017-04-01

    Full Text Available The flocculation of dissolved heavy metals is a process which has an important effect on decreasing the concentration of the colloidal elements during estuarine mixing of river water and sea or ocean water. During this important process, a large amount of colloidal elements change into particles in the form of flock and the dissolved loads decline. This study is performed to evaluate the mechanism of self-purification of heavy metals in Sardabroud's estuary. For this purpose, the effect of salinity (varying from 1 to 8.5‰ on the removal efficiency of colloidal metals (copper, zinc, lead, nickel and magnesium by flocculation process during mixing of Sardabroud River water and the Caspian Sea water was explored. The flocculation rate of Ni (25% > Zn (18.59% > Cu (16.67% > Mn(5.83% > Pb(4.86%  indicates that lead and manganese have relatively conservative behavior but nickel, zinc and copper have non-conservative behavior during Sardabroud River’s estuarine mixing. The highest removal efficiencies were obtained between salinities of 1 to 2.5%. Due to flocculation process, annual discharge of dissolved zinc, copper, lead, manganese and nickel release into the Caspian Sea via Sardabroud River would reduce from 44.30 to 36.06 ton/yr, 3.41 to 2.84 ton/yr, 10.22 to 9.7 ton/yr, 8.52 to 7.8 ton/yr and 3.41 to 2.56 ton/yr, respectively. Statistical analysis shows that the flocculation rate of Nickel is highly controlled by redox potential and dissolved oxygen. Moreover, it is found that total dissolved solid, salinity, electrical conductivity and potential of hydrogen do not have a significant influence in flocculation of studied metals.

  19. Recovery of Mn2+, Co2+ and Ni2+ from manganese nodules by redox leaching and solvent extraction

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The recovery of Mn, Co and Ni from deep-sea manganese nodules was conducted by acid oxidative leaching and solvent extraction. The results indicate that pyrrhotite used during leaching can effectively facilitate the leaching out of manganese, cobalt and nickel. The leaching behaviors of Mn, Ni and Co were determined and the influences of temperature, leaching time and sulphuric acid concentration on leaching rate were also investigated. Co and Ni are precipitated from the leaching liquor by adding sodium sulfide into solution with agitation for 2 h at 50 ℃, and the manganese sulphate is obtained by concentrating the resulting solution.By re-dissolving the precipitates of cobalt and nickel, the separation of cobalt and nickel is performed using di(2-ethylhexyl)phosphoric acid (D2EHPA) for impurities elimination with 8 stages at organic-to-aqueous(O/A) volume ratio of 3:5, and 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester (known as PC88A or P507) for cobalt extraction with 3 stages counter-current operations at O/A volume ratio of 2:3 followed by their scrubbings and strippings, respectively. The final maximum recovery rates for manganese, cobalt and nickel are 85%, 75% and 78%, respectively.

  20. The critical analysis of austenitic manganese steel T130Mn135 used for castings in the mining industry

    Science.gov (United States)

    Josan, A.; Pinca Bretotean, C.; Putan, V.

    2016-02-01

    This paper presents the critical analysis of making technology of austenitic manganese steel T130Mn135, used for castings of the type Mills hammer at a Romanian foundry. Are analyzed 11 charges of steel for castings and is determined the diagram of the heat treatment. After the applying of the heat treatment results a single-phase structure, consisting of homogeneous austenite. For all the 11 charges is presented the variation of chemical composition.

  1. Quenching effects in Cu-Al-Mn shape memory alloy

    Energy Technology Data Exchange (ETDEWEB)

    Obrado, E.; Manosa, L.; Planes, A. [Barcelona Univ. (Spain). Dept. d' Estructura i Constituents de la Materia; Romero, R.; Somoza, A. [IFIMAT, Universidad Nacional del Centro de la Provincia de Buenos Aires, Pinto 399, 7000 Tandil, and Comision de Investigaciones Cientificas de la Provincia de Buenos Aires, Buenos Aires (Argentina)

    1999-12-15

    In this paper the effect of quenching from different temperatures (T{sub q}) in a Cu-Al-Mn alloy is studied. This alloy system, which displays an L2{sub 1} ordered structure, transforms martensitically at an intermediate temperature T{sub M}, and undergoes a spin freezing process at a lower temperature T{sub f}. Positron annihilation measurements have shown that after the quench, an excess of vacancies is retained in the system, depending on T{sub q}. In addition, both T{sub M} and T{sub f} have been found to be sensitive to T{sub q}. This has been attributed to frozen-in disorder induced by the quench. Experimental results have been interpreted in terms of the growth of magnetic clusters, quenched-in vacancies and atomic disorder. (orig.)

  2. Thermodynamic stability of austenitic Ni-Mn-Cu cast iron

    Directory of Open Access Journals (Sweden)

    A. Janus

    2014-07-01

    Full Text Available The performed research was aimed at determining thermodynamic stability of structures of Ni-Mn-Cu cast iron castings. Examined were 35 alloys. The castings were tempered at 900 °C for 2 hours. Two cooling speeds were used: furnace-cooling and water-cooling. In the alloys with the nickel equivalent value less than 20,0 %, partial transition of austenite to martensite took place. The austenite decomposition ratio and the related growth of hardness was higher for smaller nickel equivalent value and was clearly larger in annealed castings than in hardened ones. Obtaining thermodynamically stable structure of castings requires larger than 20,0 % value of the nickel equivalent.

  3. Magnetic moment enhancement and spin polarization switch of the manganese phthalocyanine molecule on an IrMn(100) surface

    Energy Technology Data Exchange (ETDEWEB)

    Sun, X. [Hefei National Laboratory for Physical Sciences at Microscale and Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China); National Institute for Materials Science, 1-2-1 Sengen, Tsukuba 305-0047 (Japan); Wang, B. [Hefei National Laboratory for Physical Sciences at Microscale and Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China); Pratt, A. [National Institute for Materials Science, 1-2-1 Sengen, Tsukuba 305-0047 (Japan); Department of Physics, University of York, York YO10 5DD (United Kingdom); Yamauchi, Y. [National Institute for Materials Science, 1-2-1 Sengen, Tsukuba 305-0047 (Japan)

    2014-07-21

    The geometric, electronic, and magnetic structures of a manganese phthalocyanine (MnPc) molecule on an antiferromagnetic IrMn(100) surface are studied by density functional theory calculations. Two kinds of orientation of the adsorbed MnPc molecule are predicted to coexist due to molecular self-assembly on the surface—a top-site geometry with the Mn–N bonds aligned along the 〈100〉 direction, and a hollow-site orientation in which the Mn–N bonds are parallel to the 〈110〉 direction. The MnPc molecule is antiferromagnetically coupled to the substrate at the top site with a slight reduction in the magnetic moment of the Mn atom of the MnPc molecule (Mn{sub mol}). In contrast, the magnetic moment of the Mn{sub mol} is enhanced to 4.28 μB at the hollow site, a value larger than that in the free MnPc molecule (3.51 μB). Molecular distortion induced by adsorption is revealed to be responsible for the enhancement of the magnetic moment. Furthermore, the spin polarization of the Mn{sub mol} atom at around the Fermi level is found to change from negative to positive through an elongation of the Mn–N bonds of the MnPc. We propose that a reversible switch of the low/high magnetic moment and negative/positive spin polarization might be realized through some mechanical engineering methods.

  4. One-pot synthesis of an Mn(III)-Cu(II)-Mn(III) trinuclear heterometallic compound formed by Mn$\\cdots$S-Cu-S$\\cdots$Mn supramolecular interactions: Crystal structure of [{MnIII(salph)(H2O)}2{CuII(mnt)2}]$\\cdot$4DMF

    Indian Academy of Sciences (India)

    Vedichi Madhu; Samar K Das

    2006-11-01

    A one-pot synthesis, that includes CuCl2$\\cdot$2H2O, Na2mnt, H2salph and Mn(CH3COO)3$\\cdot$H2O, leads to the isolation of a trinuclear heterometallic compound [{MnIII(salph)(H2O)}2{CuII(mnt)2}]$\\cdot$4DMF (1) formed by Mn$\\cdots$S-Cu-S$\\cdots$Mn supramolecular interactions. Compound 1 crystallizes in the monoclinic space group 21/ with = 13.433(4), = 16.283(5), = 15.072(4) Å, = 107.785(4)°, = 2. In the crystal structure, the complex anion [CuII(mnt)2]2- bridges two [MnIII(salph)(H2O)]1+ cations through Mn$\\cdots$S contacts. The non-covalent hydrogen bonding and - interactions among the trinuclear [{MnIII(salph)(H2O)}2{CuII(mnt)2}] complexes lead to an extended chain-like arrangement of [MnIII(salph) (H2O)]1+ cations with [CuII(mnt)2]2- anions embedded in between these chains.

  5. A compact DD neutron generator-based NAA system to quantify manganese (Mn) in bone in vivo.

    Science.gov (United States)

    Liu, Yingzi; Byrne, Patrick; Wang, Haoyu; Koltick, David; Zheng, Wei; Nie, Linda H

    2014-09-01

    A deuterium-deuterium (DD) neutron generator-based neutron activation analysis (NAA) system has been developed to quantify metals, including manganese (Mn), in bone in vivo. A DD neutron generator with a flux of up to 3*10(9) neutrons s(-1) was set up in our lab for this purpose. Optimized settings, including moderator, reflector, and shielding material and thickness, were selected based on Monte Carlo (MC) simulations conducted in our previous work. Hand phantoms doped with different Mn concentrations were irradiated using the optimized DD neutron generator irradiation system. The Mn characteristic γ-rays were collected by an HPGe detector system with 100% relative efficiency. The calibration line of the Mn/calcium (Ca) count ratio versus bone Mn concentration was obtained (R(2) = 0.99) using the hand phantoms. The detection limit (DL) was calculated to be about 1.05 μg g(-1) dry bone (ppm) with an equivalent dose of 85.4 mSv to the hand. The DL can be reduced to 0.74 ppm by using two 100% HPGe detectors. The whole body effective dose delivered to the irradiated subject was calculated to be about 17 μSv. Given the average normal bone Mn concentration of 1 ppm in the general population, this system is promising for in vivo bone Mn quantification in humans.

  6. Electrochemical characterization of nano V, Ti doped MnO2 in primary lithium manganese dioxide batteries with high rate

    Science.gov (United States)

    Sun, Yang; Wang, Shengping; Dai, Yu; Lei, Xinrong

    2016-10-01

    The nano-sized γ-MnO2 precursor is synthesized using a room temperature, liquid-phase reaction route with the assistance of ultrasonic waves. The MnO2 precursor as an electrode material in lithium manganese dioxide primary batteries displays a low capacity of 140mAhg-1 (45.5% for the theoretical capacity of MnO2) at 20mAg-1. Therefore, the doped MnO2 with cationic V or/and Ti are prepared at high temperature. After the heat treatment, the γ phase precursor powder gradually converts into the β-MnO2 and exhibits a higher specific surface area with a larger pore volume and pore size, providing significantly more electrochemically active sites for the redox reaction. The doped MnO2 matrix has advantage of the ideal lattice parameters and the higher conductivity, resulting in an enhancement of the Li+ diffusion kinetics in the tunnel structure. Especially for co-doped MnO2 with V and Ti, the modified material shows an outstanding electrochemical capacity of 190mAhg-1 (61.7% for the theoretical capacity) at 20mAg-1 and 169mAhg-1 for a higher power output of 100mAg-1.

  7. Manganese hexacyanoferrate derived Mn3O4 nanocubes-reduced graphene oxide nanocomposites and their charge storage characteristics in supercapacitors.

    Science.gov (United States)

    Subramani, K; Jeyakumar, D; Sathish, M

    2014-03-14

    Mn3O4-reduced graphene oxide (RGO) nanocomposites were prepared by chemical decomposition of the manganese hexacyanoferrate (MnHCF) complex directly on the graphene surface. XRD studies revealed the formation of crystalline hausmannite Mn3O4 nanocubes in the as-prepared nanocomposites without any heat treatment. The FE-SEM images showed the formation of Mn3O4 nanocubes on the graphene surface in the as-prepared nanocomposites. HR-TEM studies confirmed the homogeneous dispersion of ∼25 nm Mn3O4 nanocubes on graphene nanosheets. The amount of Mn3O4 nanocubes and graphene in the nanocomposites was estimated using TGA analysis from room temperature to 800 °C in air. The FT-IR and Raman spectroscopic analysis confirmed the functional groups in the nanocomposites and defects in graphene nanosheets in the nanocomposites. Cyclic voltammetry and galvanostatic charge-discharge experiments demonstrated a high specific capacitance of 131 F g(-1) in 1 M Na2SO4 electrolyte at a current density of 0.5 A g(-1) for the RGM-0.5 nanocomposite. A capacitance retention of 99% was observed for 500 charge-discharge cycles at a current density of 5 A g(-1), which conformed the excellent stability of the RGM electrodes. The prepared Mn3O4-RGO nanocomposites are promising for electrochemical energy storage.

  8. Effect of loading content of copper oxides on performance of Mn-Cu mixed oxide catalysts for catalytic combustion of benzene

    Institute of Scientific and Technical Information of China (English)

    CAO Hongyan; LI Xiaoshuang; CHEN Yaoqiang; GONG Maochu; WANG Jianli

    2012-01-01

    A series of Mn-Cu mixed oxide catalysts were prepared by precipitation method.The catalysts were characterized by N2 adsorption-desorption,H2-TPR and XPS.When the loading ratio of manganese oxides to copper oxides was 8:2 or 7:3,the catalysts possessed better catalytic activity,and benzene was converted completely at 558 K.Results of H2-TPR showed that the loading of a small amount of copper oxides decreased the reduction temperature of catalysts.Results of XPS showed that the loading of a small amount of copper oxides increased the proportion of manganese and defective oxygen on the surface of catalysts,and stabilized manganese at higher oxidation state.And the catalyst with the loading ratio 7:3 was a little worse than 8:2,since the interaction between manganese oxides and copper oxides is too strong,copper oxides migrate to the surface of catalysts and manganese oxides in excess are immerged.

  9. The Ternary Alkaline-Earth Metal Manganese Bismuthides Sr2MnBi2 and Ba2Mn1-xBi2 (x ≈ 0.15).

    Science.gov (United States)

    Ovchinnikov, Alexander; Saparov, Bayrammurad; Xia, Sheng-Qing; Bobev, Svilen

    2017-10-02

    Two new ternary manganese bismuthides have been synthesized and their structures established based on single-crystal X-ray diffraction methods. Sr2MnBi2 crystallizes in the orthorhombic space group Pnma (a = 16.200(9) Å, b = 14.767(8) Å, c = 8.438(5) Å, V = 2018(2) Å(3); Z = 12; Pearson index oP60) and is isostructural to the antimonide Sr2MnSb2. The crystal structure contains corrugated layers of corner- and edge-shared [MnBi4] tetrahedra and Sr atoms enclosed between these layers. Electronic structure calculations suggest that Sr2MnBi2 is a magnetic semiconductor possessing Mn(2+) (high-spin d(5)) ions, and its structure can be rationalized within the Zintl concept as [Sr(2+)]2[Mn(2+)][Bi(3-)]2. The temperature dependence of the resistivity shows behavior consistent with a degenerate semiconductor/poor metal, and magnetic susceptibility measurements reveal a high degree of frustration resulting from the two-dimensional nature of the structure. The compositionally similar Ba2Mn1-xBi2 (x ≈ 0.15) crystallizes in a very different structure (space group Imma, a = 25.597(8) Å, b = 25.667(4) Å, c = 17.128(3) Å, V = 11253(4) Å(3); Z = 64; Pearson index oI316) with its own structure type. The complex structure boasts Mn atoms in a variety of coordination environments and can be viewed as consisting of two interpenetrating 3D frameworks, linked by Bi-Bi bonds. Ba2Mn1-xBi2 can be regarded as a highly reduced compound with anticipated metallic behavior.

  10. From discrete [Mn4] cluster to 1D complex: Two new mixed-valence manganese complexes with slow magnetization relaxation

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    A tetranuclear manganese complex [Mn4(HL)4(MeOH)4(SCN)2]·3MeOH (1) and a one-dimensional assembly of [Mn4] units, [Mn4(HL)4(MeOH)4(N(CN)2)2]·2.5MeOH (2) (H3L = 2,6-bis(hydroxymethyl)-4-methyl-phenol), have been synthesized and studied. Complexes 1 and 2 crystallize in the triclinic space group P 1and monoclinic space group P21/n, respectively. Complex 1 possesses a mixed-valence tetranuclear dicubane unit, which comprises two MnⅡ and two MnⅢ ions. Complex 2 is built from the similar tetranuclear [Mn4] units connected through two N(CN)2-anions into a 1-D chain. The temperature dependence of the magnetic susceptibilities of 1 and 2 indicates ferromagnetic interactions between the manganese ions. Frequency-dependent out-of-phase signals of alternating current magnetic susceptibilities are observed in the low temperature range for both complexes, indicating a slow magnetic relaxation.

  11. The effect of Mn substitution on the structure and magnetic properties of Se(Cu sub 1 sub - sub x Mn sub x)O sub 3 solid solution

    CERN Document Server

    Escamilla, R; Rosales, M I; Moran, E C; Alario-Franco, M A

    2003-01-01

    The effects of Mn substitution on the structure and magnetic properties of the SeMO sub 3 (M = Cu sub 1 sub - sub x Mn sub x) solid solution have been studied. Rietveld refinements of the x-ray diffraction patterns of these samples indicate that the manganese ions occupy copper sites. This replacement induces significant changes in the M-O bond lengths that give rise to abrupt decreases of the [M-O sub 6] octahedral distortion. In contrast, the M-O(1)-M and M-O(2)-M bond angles remain essentially constant. The magnetic behaviour of this solid solution was studied in the temperature range of 2 K < T < 300 K. The temperature dependence of the inverse magnetic susceptibility is well described by the Curie-Weiss law at high temperatures, in the composition range studied. We found that the substitution of Mn for Cu induces a sharp drop in the saturation moment of SeCuO sub 3. At about 10% of Mn there is a change from positive to negative Weiss constant theta sub W that is mainly due to the [M-O sub 6] octahe...

  12. Spectral analysis of Cu2+ and Mn2+ ions doped borofluorophosphate glasses

    Indian Academy of Sciences (India)

    B Sudhakar Reddy; S Buddhudu

    2007-10-01

    We report here on the development and spectral analysis of Cu2+ (0.5 mol%) and Mn2+ (0.5 mol%) ions doped in two new series of glasses. The visible absorption spectra of Cu2+ and Mn2+ glasses have shown broad absorption bands at 820 nm and 495 nm, respectively. For Cu2+ BFP glasses, excitation at 380 nm, a blue emission at 441 nm and also a weak emission at 418 nm ions have been observed. For Mn2+ ions doped BFP glasses, excitation at 410 nm and a red shift at 605 nm emission have been observed.

  13. Phase Transformations and Microstructural Evolution in Aged Mn-Cu-Based Alloys

    Science.gov (United States)

    1990-06-01

    Sakhno, V. M. and Udovenko, V. A., "Fine Crystal Structure of MnCuGe Alloys", Physical Metalurgy and Metallography, Vol. 51, No. 4, pp. 93-97, 1981. 36...93 vi I. INTRODUCTION The physical metallurgy of alloys based on the Cu-Mn system has been a subject of research for more than 40 years [Ref. 1-4...separation within it [Ref. 24-30]. The most thorough and revealing body of research on the metal physics of Cu-Mn-based alloys has been reported in the

  14. Aging Characteristics of Sn-Ag Eutectic Solder Alloy with the Addition of Cu, In, and Mn

    Science.gov (United States)

    Ghosh, M.; Kar, Abhijit; Das, S. K.; Ray, A. K.

    2009-10-01

    In the present investigation, three types of solder alloy, i.e., Sn-Ag-Cu, Sn-Ag-In, and Sn-Ag-Cu-Mn, have been prepared and joined with Cu substrate. In the reflowed condition, the joint interface is decorated with Cu6Sn5 intermetallic in all cases. During aging at 100 °C for 50 to 200 hours, Cu3Sn formation took place in the diffusion zone of the Sn-Ag-Cu and Sn-Ag-In vs Cu assembly, which was not observed for the Sn-Ag-Cu-Mn vs Cu joint. Aging also leads to enhancement in the width of reaction layers; however, the growth is sluggish (~134 KJ/mol) for the Sn-Ag-Cu-Mn vs Cu transition joint. In the reflowed condition, the highest shear strength is obtained for the Sn-Ag-Cu-Mn vs Cu joint. Increment in aging time results in decrement in shear strength of the assemblies; yet small reduction is observed for the Sn-Ag-Cu-Mn vs Cu joint. The presence of Mn in the solder alloy is responsible for the difference in microstructure of the Sn-Ag-Cu-Mn solder alloy vs Cu assembly in the reflowed condition, which in turn influences the microstructure of the same after aging with respect to others.

  15. Cu and Cu(Mn) films deposited layer-by-layer via surface-limited redox replacement and underpotential deposition

    Energy Technology Data Exchange (ETDEWEB)

    Fang, J.S., E-mail: jsfang@nfu.edu.tw [Department of Materials Science and Engineering, National Formosa University, Huwei 63201, Taiwan (China); Sun, S.L. [Department of Materials Science and Engineering, National Formosa University, Huwei 63201, Taiwan (China); Cheng, Y.L. [Department of Electrical Engineering, National Chi-Nan University, Nan-Tou 54561, Taiwan (China); Chen, G.S.; Chin, T.S. [Department of Materials Science and Engineering, Feng Chia University, Taichung 40724, Taiwan (China)

    2016-02-28

    Graphical abstract: - Abstract: The present paper reports Cu and Cu(Mn) films prepared layer-by-layer using an electrochemical atomic layer deposition (ECALD) method. The structure and properties of the films were investigated to elucidate their suitability as Cu interconnects for microelectronics. Previous studies have used primarily a vacuum-based atomic layer deposition to form a Cu metallized film. Herein, an entirely wet chemical process was used to fabricate a Cu film using the ECALD process by combining underpotential deposition (UPD) and surface-limited redox replacement (SLRR). The experimental results indicated that an inadequate UPD of Pb affected the subsequent SLRR of Cu and lead to the formation of PbSO{sub 4}. A mechanism is proposed to explain the results. Layer-by-layer deposition of Cu(Mn) films was successfully performed by alternating the deposition cycle-ratios of SLRR-Cu and UPD-Mn. The proposed self-limiting growth method offers a layer-by-layer wet chemistry-based deposition capability for fabricating Cu interconnects.

  16. Cu and Cu(Mn) films deposited layer-by-layer via surface-limited redox replacement and underpotential deposition

    Science.gov (United States)

    Fang, J. S.; Sun, S. L.; Cheng, Y. L.; Chen, G. S.; Chin, T. S.

    2016-02-01

    The present paper reports Cu and Cu(Mn) films prepared layer-by-layer using an electrochemical atomic layer deposition (ECALD) method. The structure and properties of the films were investigated to elucidate their suitability as Cu interconnects for microelectronics. Previous studies have used primarily a vacuum-based atomic layer deposition to form a Cu metallized film. Herein, an entirely wet chemical process was used to fabricate a Cu film using the ECALD process by combining underpotential deposition (UPD) and surface-limited redox replacement (SLRR). The experimental results indicated that an inadequate UPD of Pb affected the subsequent SLRR of Cu and lead to the formation of PbSO4. A mechanism is proposed to explain the results. Layer-by-layer deposition of Cu(Mn) films was successfully performed by alternating the deposition cycle-ratios of SLRR-Cu and UPD-Mn. The proposed self-limiting growth method offers a layer-by-layer wet chemistry-based deposition capability for fabricating Cu interconnects.

  17. Electronic, magnetic, elastic and thermodynamic properties of Cu{sub 2}MnGa

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, Sukriti [Department of Physics, Government Kamla Raja Girls Autonomous Post Graduate College, Gwalior 474001, Madhya Pradesh (India); Condensed Matter Theory Group, School of Studies in Physics, Jiwaji University, Gwalior 474 011, Madhya Pradesh (India); Gupta, Dinesh C., E-mail: sosfizix@gmail.com [Condensed Matter Theory Group, School of Studies in Physics, Jiwaji University, Gwalior 474 011, Madhya Pradesh (India)

    2016-08-01

    The full-potential linearized augmented plane wave method in the stable Fm-3m phase has been implemented to investigate the structural, elastic, magnetic and electronic properties of Cu{sub 2}MnGa. The optimized equilibrium lattice parameter in stable phase is found to be 5.9495 Å. By the spin resolved density of states calculations, we have shown that the exchange splitting due to Mn atom is the main reason of ferromagnetic behavior of Cu{sub 2}MnGa. The absence of energy gap in both the spin channels predicts that the material is metallic. The total and partial density of states, elastic constants, Shear, Bulk and Young’s moduli, Zener isotropy factor, Cauchy pressure, Pugh's ductility, Kleinman parameter and Poisson's ratio are reported for the first time for the alloy. Cauchy's pressure and Pugh's index of ductility label Cu{sub 2}MnGa as ductile. Cu{sub 2}MnGa is found to be ferromagnetic and anisotropic in nature. The quasi-harmonic approximations have been employed to study the pressure and temperature dependent thermodynamic properties of Cu{sub 2}MnGa. - Highlights: • It is the first attempt to predict a variety of crystal properties of Cu{sub 2}MnGa. • Cu{sub 2}MnGa shows magnetism and hence can prove to be important in modern technology. • Cu{sub 2}MnGa is ductile and hence can attract attention of scientists and technologists.

  18. Additional micromineral Mn and Cu in ration to rumen biofermentation activities of sheep in vitro method

    Directory of Open Access Journals (Sweden)

    Farida Fathul

    2010-03-01

    Full Text Available Ruminants need micro mineral for both their own requirements and rumen microbe activities. The objective of this research was to study the effect of Mn, Cu, and its combination addition in ration on the activity of in vitro fermentation using sheep rumen liquid. This research was conducted at Laboratory of Ruminant Nutrition Faculty of Animal Science Bogor Agricultural Institute. The rations were R0 = basal ration; R1 = basal ration + 40 ppm Mn; R2 = basal ration + 10 ppm Cu; dan R3 = basal ration + 40 ppm Mn + 10 ppm Cu. The result indicated that addition of Mn, Cu, or Mn+Cu did not significantly influence (P>0.05 pH, NH3, bacteria and VFA; but they significantly increased (P<0.01 dry matter digestibility (DMD and organic matter digestibility (OMD. The average: pH was 4.78 ± 0.07 – 4.89 ± 0.06; NH3 was 6.77 ± 2.07 – 7.47±0,67 mM, and VFA was 93.19 ± 55.79 – 136.61±15.31 mM. R1 gave the highest value of DMD (57.63% and OMD (70.32%. The VFA related positively to NH3 (r = 0.86; with the equation Ý = -266.9 + 54.182 X and R2 = 0.74. It was concluded that additional of Mn, Cu, or Mn+Cu did not alter pH, NH3, and VFA. The additional of Mn altered DMD, but additional of Mn+Cu reduced DMD and OMD.

  19. Activation of Manganese Oxidants with Bisulfite for Enhanced Oxidation of Organic Contaminants: The Involvement of Mn(III).

    Science.gov (United States)

    Sun, Bo; Guan, Xiaohong; Fang, Jingyun; Tratnyek, Paul G

    2015-10-20

    MnO4(-) was activated by HSO3(-), resulting in a process that oxidizes organic contaminants at extraordinarily high rates. The permanganate/bisulfite (PM/BS) process oxidized phenol, ciprofloxacin, and methyl blue at pHini 5.0 with rates (kobs ≈ 60-150 s(-1)) that were 5-6 orders of magnitude faster than those measured for permanganate alone, and ∼5 to 7 orders of magnitude faster than conventional advanced oxidation processes for water treatment. Oxidation of phenol was fastest at pH 4.0, but still effective at pH 7.0, and only slightly slower when performed in tap water. A smaller, but still considerable (∼3 orders of magnitude) increase in oxidation rates of methyl blue was observed with MnO2 activated by HSO3(-) (MO/BS). The above results, time-resolved spectroscopy of manganese species under various conditions, stoichiometric analysis of pH changes, and the effect of pyrophosphate on UV absorbance spectra suggest that the reactive intermediate(s) responsible for the extremely rapid oxidation of organic contaminants in the PM/BS process involve manganese(III) species with minimal stabilization by complexation. The PM/BS process may lead to a new category of advanced oxidation technologies based on contaminant oxidation by reactive manganese(III) species, rather than hydroxyl and sulfate radicals.

  20. Quenching of magnetic excitations in single adsorbates at surfaces: Mn on CuN/Cu(100)

    Science.gov (United States)

    Novaes, Frederico D.; Lorente, Nicolás; Gauyacq, Jean-Pierre

    2010-10-01

    The lifetimes of spin excitations of Mn adsorbates on CuN/Cu(100) are computed from first principles. The theory is based on a strong-coupling approach that evaluates the decay of a spin excitation due to electron-hole pair creation. Using a previously developed theory [Phys. Rev. Lett. 103, 176601 (2009)10.1103/PhysRevLett.103.176601 and Phys. Rev. B 81, 165423 (2010)10.1103/PhysRevB.81.165423], we compute the excitation rates by a tunneling current for all the Mn spin states. A rate equation approach permits us to simulate the experimental results by Loth and co-workers [Nat. Phys. 6, 340 (2010)]10.1038/nphys1616 for large tunneling currents, taking into account the finite population of excited states. Our simulations give us insight into the spin dynamics, in particular, in the way polarized electrons can reveal the existence of an excited-state population. In addition, it reveals that the excitation process occurs in a way very different from the deexcitation one. Indeed, while excitation by tunneling electrons proceeds via the s and p electrons of the adsorbate, deexcitation mainly involves the d electrons.

  1. Crystal Structure and Thermoelectric Properties of Lightly Vanadium-Substituted Higher Manganese Silicides (Mn1-x V x )Si γ )

    Science.gov (United States)

    Miyazaki, Yuzuru; Hamada, Haruki; Hayashi, Kei; Yubuta, Kunio

    2016-09-01

    To further enhance the thermoelectric (TE) properties of higher manganese silicides (HMSs), dissipation of layered precipitates of MnSi phase as well as optimization of hole carrier concentration are critical. We have prepared a lightly vanadium-substituted solid solution of HMS, (Mn1-x V x )Si γ , by a melt growth method. A 2% substitution of manganese with vanadium is found to dissipate MnSi precipitates effectively, resulting in a substantial increase in the electrical conductivity from 280 S/cm to 706 S/cm at 800 K. The resulting TE power factor reaches 2.4 mW/K2-m at 800 K, more than twice that of the V-free sample. The total thermal conductivity did not change significantly with increasing x owing to a reduction of the lattice contribution. As a consequence, the dimensionless figure of merit zT of the melt-grown samples increased from 0.26 ± 0.01 for x = 0 to 0.59 ± 0.01 for x = 0.02 at around 800 K.

  2. Room-temperature ferromagnetism in Mn-doped CuCrO2 nanopowders

    Directory of Open Access Journals (Sweden)

    DENG Linyan

    2015-08-01

    Full Text Available (Cu1-xMnxCrO2 (0≤x≤6 at% and Cu(Cr1-yMnyO2 (0≤y≤6 at% nanopowders were prepared by combining solid-state reaction and ball milling.It is found that all the samples have a pure 3R-CuCrO2 delafossite structure.The lattice expansion supports the Mn entrance into the Cu and Cr sublattices,respectively,in (Cu1-xMnxCrO2 and Cu(Cr1-yMnyO2,which is further proved by X-ray photoelectron spectroscopy to some degree.Room-temperature ferromagnetism is achieved in B-site Mn-doped samples,originating from the hole-mediated Cr3+-Mn3+ double-exchange interaction.The saturation magnetization of this CuMO2 delafossite (M=Cr,Mn is about an order of magnitude higher than literature values,and gradually decreases with the Mn addition due to the combined influence of the number of the M-M pairs,the M-M distances and the hole density.

  3. Stability of beta MnOOH and manganese oxide deposition from springwater.

    Science.gov (United States)

    Hem, J.D.; Roberson, C.E.; Fournier, R.B.

    1982-01-01

    beta MnOOH is precipitated preferentially (with respect to Mn3O4) at T near 0oC when Mn2+ is oxidized in aerated aqueous solutions. Upon aging in solutions open to the atmosphere, a slurry of beta MnOOH tends to disproportionate to form MnO2 and Mn2+. In such aged solutions, Mn2+ and H+ activities can be constant, and both the oxidation reaction Mn2+ + 1/4O2(aq) + 3/2H2O rt arrow beta MnOOH(c) + 2H+ and the disproportionation reaction 2beta MnOOH(c) + 2H+ rt arrow MnO2(c) + Mn2+ + 2H2O can have positive reaction affinities. It is not possible for both reactions to be in thermodynamic equilibrium in the same system unless oxygen is almost completely absent. A value for 028DELTA Gof of -129.8 + or - 0.6 kcal/mol was obtained for beta MnOOH from experimental data by assuming that the reaction affinity for the oxidation reaction is equal to that for the disproportionation, and a value of -129.8 + or - 0.5 kcal/mol was determined by measuring the redox potentials for the postulated half-reaction MnO2(c) + H+ + e- rt arrow beta MnOOH(c) at 0o, 5o, and 15oC and extrapolating to 25oC. Both these values are consistent with laboratory observations that beta MnOOH is less stable than gamma MnOOH or Mn3O4 at 25oC. Analytical data for Mn-depositing springwater samples are consistent with a non-equilibrium model involving disproportionation of either beta MnOOH or Mn3O4. (Authors' abstract)-T.R.

  4. Homogeneity testing and quantitative analysis of manganese (Mn) in vitrified Mn-doped glasses by laser-induced breakdown spectroscopy (LIBS)

    Energy Technology Data Exchange (ETDEWEB)

    Unnikrishnan, V. K.; Nayak, Rajesh; Kartha, V. B.; Santhosh, C., E-mail: santhosh.cls@manipal.edu, E-mail: unnikrishnan.vk@manipal.edu [Department of Atomic and Molecular Physics, Manipal University, Manipal (India); Sonavane, M. S. [Nuclear Recycle Board, Bhabha Atomic Research Centre, Mumbai (India); Yeotikar, R. G. [Process Development Division, Bhabha Atomic Research Centre, Mumbai (India); Shah, M. L.; Gupta, G. P.; Suri, B. M. [Laser and Plasma Technology Division, Bhabha Atomic Research Centre, Mumbai (India)

    2014-09-15

    Laser-induced breakdown spectroscopy (LIBS), an atomic emission spectroscopy method, has rapidly grown as one of the best elemental analysis techniques over the past two decades. Homogeneity testing and quantitative analysis of manganese (Mn) in manganese-doped glasses have been carried out using an optimized LIBS system employing a nanosecond ultraviolet Nd:YAG laser as the source of excitation. The glass samples have been prepared using conventional vitrification methods. The laser pulse irradiance on the surface of the glass samples placed in air at atmospheric pressure was about 1.7×10{sup 9} W/cm{sup 2}. The spatially integrated plasma emission was collected and imaged on to the spectrograph slit using an optical-fiber-based collection system. Homogeneity was checked by recording LIBS spectra from different sites on the sample surface and analyzing the elemental emission intensities for concentration determination. Validation of the observed LIBS results was done by comparison with scanning electron microscope- energy dispersive X-ray spectroscopy (SEM-EDX) surface elemental mapping. The analytical performance of the LIBS system has been evaluated through the correlation of the LIBS determined concentrations of Mn with its certified values. The results are found to be in very good agreement with the certified concentrations.

  5. Homogeneity testing and quantitative analysis of manganese (Mn in vitrified Mn-doped glasses by laser-induced breakdown spectroscopy (LIBS

    Directory of Open Access Journals (Sweden)

    V. K. Unnikrishnan

    2014-09-01

    Full Text Available Laser-induced breakdown spectroscopy (LIBS, an atomic emission spectroscopy method, has rapidly grown as one of the best elemental analysis techniques over the past two decades. Homogeneity testing and quantitative analysis of manganese (Mn in manganese-doped glasses have been carried out using an optimized LIBS system employing a nanosecond ultraviolet Nd:YAG laser as the source of excitation. The glass samples have been prepared using conventional vitrification methods. The laser pulse irradiance on the surface of the glass samples placed in air at atmospheric pressure was about 1.7×109 W/cm2. The spatially integrated plasma emission was collected and imaged on to the spectrograph slit using an optical-fiber-based collection system. Homogeneity was checked by recording LIBS spectra from different sites on the sample surface and analyzing the elemental emission intensities for concentration determination. Validation of the observed LIBS results was done by comparison with scanning electron microscope- energy dispersive X-ray spectroscopy (SEM-EDX surface elemental mapping. The analytical performance of the LIBS system has been evaluated through the correlation of the LIBS determined concentrations of Mn with its certified values. The results are found to be in very good agreement with the certified concentrations.

  6. Synthetic, structural, spectroscopic and theoretical study of a Mn(III)-Cu(II) dimer containing a Jahn-Teller compressed Mn ion

    DEFF Research Database (Denmark)

    Berg, Nelly; Hooper, Thomas N.; Liu, Junjie;

    2013-01-01

    The heterobimetallic complex [Cu(II)Mn(III)(L)(2)(py)(4)](ClO(4))·EtOH (1) built using the pro-ligand 2,2'-biphenol (LH(2)), contains a rare example of a Jahn-Teller compressed Mn(III) centre. Dc magnetic susceptibility measurements on 1 reveal a strong antiferromagnetic exchange between the Cu(I...

  7. Martensitic transformation in Cu-doped NiMnGa magnetic shape memory alloys

    Institute of Scientific and Technical Information of China (English)

    Li Pan-Pan; Wang Jing-Min; Jiang Cheng-Bao

    2011-01-01

    This paper studies the martensitic transformation in the Cu-doped NiMnGa alloys. The orthorhombic martensite transforms to L21 cubic austenite by Cu substituting for Ni in the Ni50-x:CuxMn31Ga19 (x=2-10) alloys, the martensitic transformation temperature decreases significantly with the rate of 40 K per Cu atom addition. The variation of the Fermi sphere radius (kF) is applied to evaluate the change of the martensitic transformation temperature. The increase of kF leads to the increase of the martensitic transformation temperature.

  8. EPR spectrum of a manganese center observed in. gamma. -irradiated (CH/sub 3/)/sub 3/SnMn(CO)/sub 5/ single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Morton, J.R.; Preston, K.F.; Thibodeau, D.L. (National Research Council of Canada, Ottawa, Ontario. Div. of Chemistry)

    1982-06-01

    An EPR spectrum detected in ..gamma..-irradiated single crystals of trimethyltin-manganese pentacarbonyl was analyzed in terms of anisotropic interactions between a single unpaired electron, a manganese nucleus, and the magnetic field. At 100 K, the principal components of the g and /sup 55/Mn-hyperfine tensors are 2.0399, 2.0279, 2.0018 and 84.1 MHz, 106.3 MHz, 162.3 MHz, respectively. The free radical is believed to be (CH/sub 3/)/sub 3/SnMn(CO)/sub 4//sup -/, formed from the parent carbonyl by electron addition and loss of an equatorial ligand.

  9. Magnetic properties of Cu substituted NdMn2Si2 intermetallics

    Science.gov (United States)

    Elmali, A.; Dincer, I.; Elerman, Y.; Ehrenberg, H.; Fuess, H.

    2005-05-01

    The structure and magnetic properties of NdMn2-xCuxSi2 (0.2 x 1) were studied by X-ray powder diffraction and magnetization measurements. In this study, we investigate the variations in the magnetic properties of NdMn2-xCuxSi2 as a function of Cu concentration by examing the evolution of the features in the temperature dependence of the magnetization. Earlier neutron diffraction experiments showed that the ferromagnetic Mn planes are ordered antiparallel along the c-axis below 380 K and the Nd sublattice orders at 33 K in NdMn2Si2. The ordering of the Nd sublattice reconfigures the ordering in Mn sublattice and leads to ferromagnetic ordering. With increasing amount of Cu, the Curie temperature has a maximum value of 120 K at x = 0.7 and decreases for the samples with x 0.8.

  10. Electrocatalysis of oxygen reduction on Cu{sub x}Mn{sub 3-x}O{sub 4} (1.0 {<=} x {<=} 1.4) spinel particles/polypyrrole composite electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Rios, E.; Abarca, S.; Daccarett, P.; Gautier, J.L. [Laboratorio de Fisicoquimica y Electroquimica de Solidos, Departamento de Quimica de los Materiales, Facultad de Quimica y Biologia, Universidad de Santiago de Chile, Av. L. B. O' Higgins 3363, Santiago (Chile); Nguyen Cong, H.; Martel, D. [Laboratoire commun au CNRS et a l' Universite Louis Pasteur, LC 3, UMR 7177,1-4 rue Blaise Pascal, 67000 Strasbourg (France); Marco, J.F.; Gancedo, J.R. [Instituto de Quimica-Fisica ' ' Rocasolano' ' , CSIC, c/Serrano, 119, 28006 Madrid (Spain)

    2008-10-15

    Spinel-type binary transition metal oxides of copper and manganese with composition Cu{sub x}Mn{sub 3-x}O{sub 4} (with x = 1.0; 1.1; 1.2; 1.3 and 1.4) were prepared in powder forms by thermal decomposition of nitrate precursors at different temperatures. Their structural properties have been examined by X-ray powder diffraction (XRD), oxidation power and X-ray Photoelectron Spectroscopy (XPS) measurements. To study the effects of solid state properties of the spinel-type compounds on their electrocatalytic activity for the oxygen reduction reaction (orr) in aqueous KCl-KOH solutions, the cathodic polarization characteristics were investigated on composite electrodes of copper and manganese spinel-type oxides nanoparticles embedded in an electrically conductive polymer. These electrodes consisted of multilayered composite electrodes on conductive glass (CG), having the structure CG/PPy/PPy (Ox)/PPy, where PPy is the polypyrrole and Ox is a mixed valence oxide with the general composition Cu{sub x}Mn{sub 3-x}O{sub 4} (1.0 {<=} x {<=} 1.4). The data have shown that the substitution of Mn by Cu increases the catalytic activity, the maximum being that exhibited by Cu{sub 1.4}Mn{sub 1.6}O{sub 4}. Correlations between solid state chemistry and electrocatalytical reactivities towards the oxygen reduction reaction in alkaline media were also investigated on the composite powder electrodes of Cu{sub x}Mn{sub 3-x}O{sub 4} (1.0 {<=} x {<=} 1.4). The results have indicated that the copper content promotes not only the Mn{sup 4+} formation but also the increase of the Mn{sup 4+}/Mn{sup 3+} relation. The change of the Mn{sup 4+}/Mn{sup 3+} ratio as a function of x has been correlated to the electrocatalytical parameters of the orr. The enhanced activity that is observed is related to the higher occurrence of the Mn{sup 4+}/Mn{sup 3+} solid state redox couple in octahedral sites. (author)

  11. Evaluation of manganese peroxidase (MnP) for its ability to resist the ozonization and thereafter decolorize methyl orange.

    Science.gov (United States)

    Cheng, Zhou; Xiang-hua, Wen; Xi, Zhao

    2010-01-01

    The goal of this study was to determine whether ozone can be used to suppress bacterial growth in operating a white rot fungi reactor system. The effects of ozone dose on the activity of manganese peroxidase (MnP) and on the death rate of Escherichia coli were investigated. The results showed that at ozone dose of 0.98 mg/L the MnP activity was not affected after 40 min continuous treatment while the Escherichia coli inactivation rate can reach 99.9% after 30 min; In addition, the MnP that exposed to ozone dose of 1.56 mg/L for 40 min maintained their activity for decolorization of Methyl Orange. After 16 h, the decolorization rate of Methyl Orange was about 41%. These results showed that MnP have the ability to resist to some extent the attack of ozonization, which suggest that ozone might have its potential in suppressing the bacteria contamination in operating the white rot fungi reactor.

  12. Thermodynamic modeling to analyse composition of carbonaceous coatings of MnO and other oxides of manganese grown by MOCVD

    Indian Academy of Sciences (India)

    Sukanya Dhar; A Varade; S A Shivashankar

    2011-02-01

    Equilibrium thermodynamic analysis has been applied to the low-pressure MOCVD process using manganese acetylacetonate as the precursor. ``CVD phase stability diagrams” have been constructed separately for the processes carried out in argon and oxygen ambient, depicting the compositions of the resulting films as functions of CVD parameters. For the process conduced in argon ambient, the analysis predicts the simultaneous deposition of MnO and elemental carbon in 1:3 molar proportion, over a range of temperatures. The analysis predicts also that, if CVD is carried out in oxygen ambient, even a very low flow of oxygen leads to the complete absence of carbon in the film deposited oxygen, with greater oxygen flow resulting in the simultaneous deposition of two different manganese oxides under certain conditions. The results of thermodynamic modeling have been verified quantitatively for lowpressure CVD conducted in argon ambient. Indeed, the large excess of carbon in the deposit is found to constitute a MnO/C nanocomposite, the associated cauliflower-like morphology making it a promising candidate for electrode material in supercapacitors. CVD carried out in oxygen flow, under specific conditions, leads to the deposition of more than one manganese oxide, as expected from thermodynamic analysis (and forming an oxide–oxide nanocomposite). These results together demonstrate that thermodynamic analysis of the MOCVD process can be employed to synthesize thin films in a predictive manner, thus avoiding the inefficient trial-and-error method usually associated with MOCVD process development. The prospect of developing thin films of novel compositions and characteristics in a predictive manner, through the appropriate choice of CVD precursors and process conditions, emerges from the present work.

  13. Sol gel synthesis and characterization studies of Cupromanganite CaCu3Mn4O12

    Science.gov (United States)

    Nurulhuda, A.; Warikh, A. R. M.; Hafizzal, Y.

    2017-08-01

    A single-phase CaCu3Mn4O12 electroceramic had been prepared via sol gel method and fairly well densified at relative low temperature under atmospheric condition where the crystallization of CaCu3Mn4O12 occurred due to amorphous polymeric mixture. The precursor was prepared by mixing the solutions with 0.6 M citric acid (C6H8O7) as a chelating reagent with the mol ratio 1:2. The precursor gel formed was calcined and sintered at range 400 °C to 800°C by varying dwell time. Material formations under the reported conditions have been confirmed by X-ray diffraction (XRD). The results show that the formation of CaCu3Mn4O12 started at 500 ° C and was formed completely at 700 ° C for 18 hours. The microstructure of all CaCu3Mn4O12 was analysed using field emission scanning electron microscopy (FESEM). A smaller particle size with higher grain boundary was obtained at sintering 700°C to 800°C. FESEM results show the significant influence of calcinations and sintering parameter on the microstructure behaviour of CaCu2Mn4O12.

  14. Impact of Mn(II)-Manganese Oxide Reactions on Ni and Zn Speciation.

    Science.gov (United States)

    Hinkle, Margaret A G; Dye, Katherine G; Catalano, Jeffrey G

    2017-03-01

    Layered Mn oxide minerals (phyllomanganates) often control trace metal fate in natural systems. The strong uptake of metals such as Ni and Zn by phyllomanganates results from adsorption on or incorporation into vacancy sites. Mn(II) also binds to vacancies and subsequent comproportionation with structural Mn(IV) may alter sheet structures by forming larger and distorted Mn(III)O6 octahedra. Such Mn(II)-phyllomanganate reactions may thus alter metal uptake by blocking key reactive sites. Here we investigate the effect of Mn(II) on Ni and Zn binding to phyllomanganates of varying initial vacancy content (δ-MnO2, hexagonal birnessite, and triclinic birnessite) at pH 4 and 7 under anaerobic conditions. Dissolved Mn(II) decreases macroscopic Ni and Zn uptake at pH 4 but not pH 7. Extended X-ray absorption fine structure spectroscopy demonstrates that decreased uptake at pH 4 corresponds with altered Ni and Zn adsorption mechanisms. These metals transition from binding in the interlayer to sheet edges, with Zn increasing its tetrahedrally coordinated fraction. These effects on metal uptake and binding correlate with Mn(II)-induced structural changes, which are more substantial at pH 4 than 7. Through these structural effects and the pH-dependence of Mn(II)-metal competitive adsorption, system pH largely controls metal binding to phyllomanganates in the presence of dissolved Mn(II).

  15. Simulations of irradiated-enhanced segregation and phase separation in Fe-Cu-Mn alloys

    Science.gov (United States)

    Li, Boyan; Hu, Shenyang; Li, Chengliang; Li, Qiulin; Chen, Jun; Shu, Guogang; Henager, Chuck, Jr.; Weng, Yuqing; Xu, Ben; Liu, Wei

    2017-09-01

    For reactor pressure vessel steels, the addition of Cu, Mn, and Ni has a positive effect on their mechanical, corrosion and radiation resistance properties. However, experiments show that radiation-enhanced segregation and/or phase separation is one of the important material property degradation processes. In this work, we develop a model integrating rate theory and phase-field approaches to investigate the effect of irradiation on solute segregation and phase separation. The rate theory is used to describe the accumulation and clustering of radiation defects, while the phase-field approach describes the effect of radiation defects on phase stability and microstructure evolution. The Fe-Cu-Mn ternary alloy is taken as a model system. The free energies used in the phase-field model are from CALPHAD. Spatial dependent radiation damage from atomistic simulations is introduced into the simulation cell for a given radiation dose rate. The radiation effect on segregation and phase separation is taken into account through the defect concentration dependence of solute mobility. Using the model, the effect of temperature and radiation rates on Cu and Mn segregation and Cu-rich phase nucleation were systematically investigated. The segregation and nucleation mechanisms were analyzed. The simulations demonstrate that the nucleus of Cu precipitates has a core-shell composition profile, i.e. Cu-rich at the center and Mn-rich at the interface, in good agreement with theoretical calculations as well as experimental observations.

  16. Synthesis, structure and electrochemical properties of lanthanum manganese nanofibers doped with Sr and Cu

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Yi; Lin, Baoping, E-mail: lbp@seu.edu.cn; Sun, Ying; Yang, Hong; Zhang, Xueqin

    2015-07-25

    Highlights: • La{sub x}Sr{sub 1−x}Cu{sub 0.1}Mn{sub 0.9}O{sub 3−δ} (0.3 ⩽ x ⩽ 1) (LNF-x) electrospinning nanofibers were firstly synthesized. • The LNF-0.5 possessed superior capacitive performance (464.5 F g{sup −1}) at Na{sub 2}SO{sub 4} electrolyte. • The maximum energy density of 64.5 W h kg{sup −1} are achieved at a power density of 2 kW kg{sup −1}. • This symmetric supercapacitor also shows an excellent cycling life. - Abstract: La{sub x}Sr{sub 1−x}Cu{sub 0.1}Mn{sub 0.9}O{sub 3−δ} (LNF-x) (0.1 ⩽ x ⩽ 1) nanofibers are prepared by electrospun method. The structure of LNF-x and the electrochemical properties of LNF-x in 1 M Na{sub 2}SO{sub 4} aqueous electrolyte are investigated. As a result, LNF-x nanofibers present a perovskite structure, and the LNF-0.5 sample exhibits the highest specific capacitance value of 464.5 F g{sup −1} at a current density of 2 A g{sup −1}. The maximum energy density of 64.5 W h kg{sup −1} are achieved at a power density of 2 kW kg{sup −1} for the symmetric supercapacitor prepared by La{sub 0.5}Sr{sub 0.5}Cu{sub 0.1}Mn{sub 0.9}O{sub 3−δ} nanofibers. More importantly, this symmetric supercapacitor also shows an excellent cycling life after 2000 charging and discharging cycles. Those results offer a suitable design of electrode materials for high-performance supercapacitors.

  17. CARACTERIZATION OF Cu-Al-Mn ALLOYS FABRICATED USING ARC FURNACE

    Directory of Open Access Journals (Sweden)

    Diego E. Velázquez

    2016-06-01

    Full Text Available Two alloys of Cu-Al-Mn fabricated using an arc furnace built at the Instituto de Física de Materiales Tandil (IFIMAT were studied. The manufacture of alloys containing Mn is difficult, due to their high melting point and its low vapor pressure. Moreover, Mn at high temperature easily reacts with the materials used to build crucibles or capsules. In the casting arc difficulties arise to prevent volatilization, so it is very important the choice of electrode, the source setting, cooling, and the arrangement of the pure materials into the crucible. Critical temperatures of martensitic transformation and order were determined by Differential Scanning Calorimetry (DSC. Using Optical Microscopy (OM the presence of martensite phase was determined. From the results obtained it is concluded that this method is suitable for producing Cu-Al-Mn alloys.

  18. Tetragonal phase of epitaxial room-temperature antiferromagnet CuMnAs.

    Science.gov (United States)

    Wadley, P; Novák, V; Campion, R P; Rinaldi, C; Martí, X; Reichlová, H; Zelezný, J; Gazquez, J; Roldan, M A; Varela, M; Khalyavin, D; Langridge, S; Kriegner, D; Máca, F; Mašek, J; Bertacco, R; Holý, V; Rushforth, A W; Edmonds, K W; Gallagher, B L; Foxon, C T; Wunderlich, J; Jungwirth, T

    2013-01-01

    Recent studies have demonstrated the potential of antiferromagnets as the active component in spintronic devices. This is in contrast to their current passive role as pinning layers in hard disk read heads and magnetic memories. Here we report the epitaxial growth of a new high-temperature antiferromagnetic material, tetragonal CuMnAs, which exhibits excellent crystal quality, chemical order and compatibility with existing semiconductor technologies. We demonstrate its growth on the III-V semiconductors GaAs and GaP, and show that the structure is also lattice matched to Si. Neutron diffraction shows collinear antiferromagnetic order with a high Néel temperature. Combined with our demonstration of room-temperature-exchange coupling in a CuMnAs/Fe bilayer, we conclude that tetragonal CuMnAs films are suitable candidate materials for antiferromagnetic spintronics.

  19. Effect of Sn on the Color and Tarnishing of Cu-Mn-Zn Alloys

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The effect of Sn on the color and tarnishing of Cu-Mn-Zn alloys is investigated quantitatively. Using the CIE LAB color system,color parameters such as L*, a* and b* are selected to describe the surface color of alloys while the color difference (△E*)is used to evaluate the color stability. The results show that with the increase of Sn, the color change of Cu-Mn-Zn alloys is greatly reduced and the corrosion resistance in the synthetic sweat is improved dramatically. However, up to 4.4 wt pct Sn does not change the color of Cu-Mn-Zn alloys much. XPS and AES are employed to analyze the tarnished surface. It is proved that a Sn enriched film is formed and Sn takes the form of Sn oxide. This thin and protective oxide film can prevent alloy from further tarnishing.

  20. Cumulation of Cu, Zn, Cd, and Mn in Plants of Gardno Lake

    Directory of Open Access Journals (Sweden)

    Trojanowski J.

    2013-04-01

    Full Text Available In the present paper there have been shown the results of research on yhe content of Zn, Cd, Cu, Mn and Pb in chosen plants of Lake Gardno.The biggest concentration of those metals has been observed in Potamogton natans and Elodea canadensis, on average Zn – 34.9, Pb -2.77, Cd – 0.62, Cu – 3.24 and Mn – 257.4 μg g-1. It has been found that the over-ground parts of the plants under analysis cumulate several times less of heavy metals than their roots. The determined enrichment factors enabled the researchers to state that Cu in the examined plants is of natural origin while Mn, Cd and Zn – of anthropogenic origin.

  1. Covalent Metal-Metal-Bonded Mn4 Tetrahedron Inscribed within a Four-Coordinate Manganese Cubane Cluster, As Evidenced by Unexpected Temperature-Independent Diamagnetism.

    Science.gov (United States)

    Vaddypally, Shivaiah; Jovinelli, Daniel J; McKendry, Ian G; Zdilla, Michael J

    2017-04-03

    The electronic structures of the manganese(IV) cubane cluster Mn(μ3-N(t)Bu)4(N(t)Bu)4 (1) and its one-electron-oxidized analogue, the 3:1 Mn(IV)/Mn(V) cluster [Mn(μ3-N(t)Bu)4(N(t)Bu)4](+)[PF6](-) (1(+)[PF6]), are described. The S = 0 spin quantum number of 1 is explained by a diamagnetic electronic structure where all metal-based d electrons are paired in Mn-Mn bonding orbitals. Temperature- and power-dependent studies of the S = (1)/2 electron paramagnetic resonance signal of 1(+) are consistent with an electronic structure described as a delocalized one-electron radical.

  2. Structural and surface changes of copper modified manganese oxides

    Energy Technology Data Exchange (ETDEWEB)

    Gac, Wojciech, E-mail: wojciech.gac@umcs.lublin.pl; Słowik, Grzegorz; Zawadzki, Witold

    2016-05-01

    Highlights: • Formation of MnO with regular rippled-like surface patterns. • Synthesis of copper nanorods supported on MnO nanoparticles. • Hydrogen production in steam methanol reforming over supported copper nanorods. - Abstract: The structural and surface properties of manganese and copper–manganese oxides were investigated. The oxides were prepared by the redox-precipitation method. X-ray diffraction and electron microscopy studies evidenced transformation of cryptomelane-type nanoparticles with 1-D channel structure into the large MnO crystallites with regular rippled-like surface patterns under reduction conditions. The development of Cu/CuO nanorods from strongly dispersed species was evidenced. Coper-modified manganese oxides showed good catalytic performance in methanol steam reforming reaction for hydrogen production. Low selectivity to CO was observed in the wide range of temperatures.

  3. Magnetic properties and electronic structure of R{sub 3}T{sub 4}X{sub 4} (R: La-Nd, Gd-Er; T: Mn, Cu; X: Ge, Sn) compounds

    Energy Technology Data Exchange (ETDEWEB)

    Szytula, A.; Wawrzynska, E.; Penc, B.; Stuesser, N.; Tomkowicz, Z.; Zygmunt, A

    2004-03-24

    The results of magnetic and neutron diffraction studies of a new series of intermetallic compounds R{sub 3}T{sub 4}X{sub 4} (R: La-Nd, Gd-Er; T: Mn, Cu; X: Ge, Sn) are presented. These compounds crystallize in the orthorhombic Gd{sub 3}Cu{sub 4}Ge{sub 4}-type structure (space group Immm). The rare earth atoms occupy two non-equivalent crystallographic positions. All the investigated compounds are antiferromagnets. In the R{sub 3}Mn{sub 4}Sn{sub 4} series the rare earth and the manganese magnetic moments order at different temperatures: the rare earth moments order at 25 K (R: Pr) and 60 K (R: Nd), while the manganese moments order at 300 K (La), 230 K (Pr) and 210 K (Nd). The R{sub 3}Cu{sub 4}Ge{sub 4} compounds are antiferromagnets with Neel temperatures between 23 K (for Tb{sub 3}Cu{sub 4}Ge{sub 4}) and 5.9 K (for Er{sub 3}Cu{sub 4}Sn{sub 4}). For Tb{sub 3}Cu{sub 4}Ge{sub 4}, Er{sub 3}Cu{sub 4}Ge{sub 4}, Ho{sub 3}Cu{sub 4}Sn{sub 4} and Er{sub 3}Cu{sub 4}Sn{sub 4} further phase transitions occur below the Neel temperature. The magnetic moments are localized only on the rare earth atoms. The moments located at different crystallographic sites have different values and order at different temperatures. The electronic structure of Gd{sub 3}Cu{sub 4}X{sub 4} (X: Ge, Sn) was studied by X-ray photoemission spectroscopy (XPS). The complex character of the valence band influences the magnetic properties of these compounds.

  4. Ferroelectricity of Europium Manganese Oxide EuMn2O5 with Helimagnetic Ordering

    OpenAIRE

    Nakamura, H.; Ishikawa, M; Kohn, K.

    1997-01-01

    From the measurements of pyroelectricity, dielectric constant, magnetic susceptibility and specific heat, we conclude that EuMn2O5 is ferroelectric below the Curie temperature TC of 38.6 K. This temperature coincides with the Néel temperature of the helimagnetic ordering of Mn3+ and Mn4+ moments within the accuracy of the measurements. The spontaneous polarization is along the b-direction.

  5. Catalytic hydrothermal treatment of pulping effluent using a mixture of Cu and Mn metals supported on activated carbon as catalyst.

    Science.gov (United States)

    Yadav, Bholu Ram; Garg, Anurag

    2016-10-01

    The present study was performed to investigate the performance of activated carbon-supported copper and manganese base catalyst for catalytic wet oxidation (CWO) of pulping effluent. CWO reaction was performed in a high pressure reactor (capacity = 0.7 l) at temperatures ranging from 120 to 190 °C and oxygen partial pressures of 0.5 to 0.9 MPa with the catalyst concentration of 3 g/l for 3 h duration. With Cu/Mn/AC catalyst at 190 °C temperature and 0.9 MPa oxygen partial pressures, the maximum chemical oxygen demand (COD), total organic carbon (TOC), lignin, and color removals of 73, 71, 86, and 85 %, respectively, were achieved compared to only 52, 51, 53, and 54 % removals during the non-catalytic process. Biodegradability (in terms of 5-day biochemical oxygen demand (BOD5) to COD ratio) of the pulping effluent was improved to 0.38 from an initial value of 0.16 after the catalytic reaction. The adsorbed carbonaceous fraction on the used catalyst was also determined which contributed meager TOC reduction of 3-4 %. The leaching test showed dissolution of the metals (i.e., Cu and Mn) from the catalysts in the wastewater during CWO reaction at 190 °C temperature and 0.9 MPa oxygen partial pressures. In the future, the investigations should focus on the catalyst reusability.

  6. Dissociative excitation of the manganese atom quartet levels by collisions e-MnBr2

    Science.gov (United States)

    Smirnov, Yu M.

    2017-04-01

    Dissociative excitation of quartet levels of the manganese atom was studied in collisions of electrons with manganese dibromide molecules. Eighty-two cross-sections for transitions originating at odd levels and eleven cross-sections for transitions originating at even levels have been measured at an incident electron energy of 100 eV. An optical excitation function has been recorded in the electron energy range of 0–100 eV for transitions originating from 3d 64p z 4 F° levels. For the majority of transitions, a comparison of the resulting cross-section values to cross-sections produced by direct excitation is provided.

  7. Relation of Zn, Fe, Cu and Mn between progenies of mate-tree and soil

    Directory of Open Access Journals (Sweden)

    Josiane Cava Guimarães

    2014-06-01

    Full Text Available The mate tea tree (Ilex Paraguariensis St. Hil. has considerable growth in acid a low fertility soils. The knowledge of soil and plant relation will contribute to genetic improvement programs, as highly capable progenies in nutrient acquisition may be selected. The objective of this study was to evaluate the interference of provenance and, or progenies, in relations established among the extractable contents of Zn, Fe, Cu and Mn, via Mehlich-1 (1:10; and EDTA (1%, with the corresponding contents in the mate tea tree leaves. In the experiment two provenances, Ivaí-PR and Barão de Cotegipe-RS, with five progenies each considered as treatments. The samples were distributed in four randomized blocks, totalizing 120 plant leaf samples, related to 120 soil samples of a Red Distrophic Latosol. The results were analyzed and fitted in regression equations. In Ivaí provenance Zn and Mn from the soil correlated with their contents in the leaves for progeny 04, for both extracts. For provenances 08 and 10, soil Mn via EDTA correlated with leaf Mn contents, while via Mehlich-1 only for progeny 10. In the provenance of Barão de Cotegipe, the correlations between soil and leaves for Zn, Fe and Cu occurred for the EDTA extract in the progenies 61, 65 and 69 respectively. For Mn and Cu, via Melich-1 the correlations occurred for progenies 53 and 69 respectively, and still for Cu, via EDTA, for progeny 53.

  8. Magnetic properties of Cu substituted NdMn{sub 2}Si{sub 2} intermetallics

    Energy Technology Data Exchange (ETDEWEB)

    Elmali, A.; Dincer, I.; Elerman, Y. [Ankara University, Faculty of Engineering, Department of Engineering Physics, 06100 Besevler-Ankara (Turkey); Ehrenberg, H.; Fuess, H. [Institute for Materials Science, Darmstadt University of Technology, Petersenstrasse 23, 64287 Darmstadt (Germany)

    2005-05-01

    The structure and magnetic properties of NdMn{sub 2-x}Cu{sub x}Si{sub 2} (0.2{<=}x{<=}1) were studied by X-ray powder diffraction and magnetization measurements. In this study, we investigate the variations in the magnetic properties of NdMn{sub 2-x}Cu{sub x}Si{sub 2} as a function of Cu concentration by examining the evolution of the features in the temperature dependence of the magnetization. Earlier neutron diffraction experiments showed that the ferromagnetic Mn planes are ordered antiparallel along the c-axis below 380 K and the Nd sublattice orders at 33 K in NdMn{sub 2}Si{sub 2}. The ordering of the Nd sublattice reconfigures the ordering in Mn sublattice and leads to ferromagnetic ordering. With increasing amount of Cu, the Curie temperature has a maximum value of 120 K at x=0.7 and decreases for the samples with x{>=}0.8. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  9. Chemical effect on the K shell fluorescence yield of Fe, Mn, Co, Cr and Cu compounds

    Indian Academy of Sciences (India)

    U Turgut

    2004-11-01

    Chemical effects on the K shell fluorescence yields of Fe, Mn, Co, Cr and Cu compounds were investigated. Samples were excited using 59.5 keV energy photons from a 241Am radioisotope source. K X-rays emitted by samples were counted by a Si(Li) detector with a resolution 160 eV at 5.9 keV. Chemical effects on the K shell fluorescence yields (K) for Fe, Mn, Co, Cr and Cu compounds were observed. The values are compared with theoretical, semiempirical fit and experimental ones for the pure elements.

  10. Modeling and analysis of soybean (Glycine max. L Cu/Zn, Mn and Fe superoxide dismutases

    Directory of Open Access Journals (Sweden)

    V. Ramana Gopavajhula

    2013-01-01

    Full Text Available Superoxide dismutase (SOD, EC 1.15.1.1 is an important metal-containing antioxidant enzyme that provides the first line of defense against toxic superoxide radicals by catalyzing their dismutation to oxygen and hydrogen peroxide. SOD is classified into four metalloprotein isoforms, namely, Cu/Zn SOD, Mn SOD, Ni SOD and Fe SOD. The structural models of soybean SOD isoforms have not yet been solved. In this study, we describe structural models for soybean Cu/Zn SOD, Mn SOD and Fe SOD and provide insights into the molecular function of this metal-binding enzyme in improving tolerance to oxidative stress in plants.

  11. Mobilization of manganese by basalt associated Mn(II)-oxidizing bacteria from the Indian Ridge System.

    Science.gov (United States)

    Sujith, P P; Mourya, B S; Krishnamurthi, S; Meena, R M; Loka Bharathi, P A

    2014-01-01

    The Indian Ridge System basalt bearing Mn-oxide coatings had todorokite as the major and birnesite as the minor mineral. We posit that microorganisms associated with these basalts participate in the oxidation of Mn and contribute to mineral deposition. We also hypothesized that, the Mn-oxidizing microbes may respond reversibly to pulses of fresh organic carbon introduced into the water column by mobilizing the Mn in Mn-oxides. To test these two hypotheses, we enumerated the number of Mn-oxidizers and -reducers and carried out studies on the mobilization of Mn by microbial communities associated with basalt. In medium containing 100 μM Mn(2+), 10(3) colony forming units (CFU) were recovered with undetectable number of reducers on Mn-oxide amended medium, suggesting that the community was more oxidative. Experiments were then conducted with basalt fragments at 4±2 °C in the presence 'G(+)' and absence 'G(-)' of glucose (0.1%). Controls included set-ups, some of which were poisoned with 15 mM azide and the others of which were heat-killed. The mobilization of Mn in the presence of glucose was 1.76 μg g(-1) d(-1) and in the absence, it was 0.17 μg g(-1) d(-1) after 150 d. Mn mobilization with and without added glucose was 13 and 4 times greater than the corresponding azide treated controls. However, rates in 'G(+)' were 16 times and 'G(-)' 24 times more than the respective heat killed controls. The corresponding total counts in the presence of added glucose increased from 1.63×10(6) to 6.71×10(7) cells g(-1) and from 1.41×10(7) to 3.52×10(7) cells g(-1) in its absence. Thus, the addition of glucose as a proxy for organic carbon changed the community's response from Mn(II)-oxidizing to Mn(IV)-reducing activity. The results confirm the participation of Mn oxidizing bacteria in the mobilization of Mn. Identification of culturable bacteria by 16S rRNA gene analysis showed taxonomic affiliations to Bacillus, Exiguobacterium, Staphylococcus, Brevibacterium and

  12. Synthesis and characterization of manganese doped CeO2 nanopowders from hydrolysis and oxidation of Ce37Mn18C45

    Institute of Scientific and Technical Information of China (English)

    DU Yanan; NI Jiansen; HU Pengfei; WANG Jun'an; HOU Xueling; XU Hui

    2013-01-01

    The Mn-doped CeO2 nanopowders with high catalysis activity were successfully fabricated through a simple hydrolyzed-oxidized approach.Firstly,the alloy Ce37Mn18C45 was prepared in vacuum induction melting furnace.Subsequently,Mn-doped CeO2 nanopowders with 142 m2/g of specific surface area were obtained through a simple hydrolyzed-oxidized procedure of the alloy.Those nanopowders were heat treated at different temperatures.The obtained materials were characterized by X-ray diffraction (XRD),transmission electron microscopy (TEM),high-resolution transmission electron microscopy (HRTEM) and energy dispersive spectroscopy (EDS).And the catalytic activity on vinyl chloride (VC) emission combustion was investigated.The results showed that those nanopowders after hydrolyzed-oxidized from Ce37Mn1sC45 mainly consisted of CeO2 and Mn3O4.Manganese element increased the thermal stability of CeO2 nanopowders.The Mn-doped CeO2 nanopowders had three morphologies.Small particles were Mn-doped CeO2,square particles were Mn3O4 and the rods were Mn3O4 and Mn2O3.The Mn-doped CeO2 nanopowders had good vinyl chloride (VC) emission catalytic performance.

  13. Spectro-photometric determinations of Mn, Fe and Cu in aluminum master alloys

    Science.gov (United States)

    Rehan; Naveed, A.; Shan, A.; Afzal, M.; Saleem, J.; Noshad, M. A.

    2016-08-01

    Highly reliable, fast and cost effective Spectro-photometric methods have been developed for the determination of Mn, Fe & Cu in aluminum master alloys, based on the development of calibration curves being prepared via laboratory standards. The calibration curves are designed so as to induce maximum sensitivity and minimum instrumental error (Mn 1mg/100ml-2mg/100ml, Fe 0.01mg/100ml-0.2mg/100ml and Cu 2mg/100ml-10mg/ 100ml). The developed Spectro-photometric methods produce accurate results while analyzing Mn, Fe and Cu in certified reference materials. Particularly, these methods are suitable for all types of Al-Mn, Al-Fe and Al-Cu master alloys (5%, 10%, 50% etc. master alloys).Moreover, the sampling practices suggested herein include a reasonable amount of analytical sample, which truly represent the whole lot of a particular master alloy. Successive dilution technique was utilized to meet the calibration curve range. Furthermore, the workout methods were also found suitable for the analysis of said elements in ordinary aluminum alloys. However, it was observed that Cush owed a considerable interference with Fe, the later one may not be accurately measured in the presence of Cu greater than 0.01 %.

  14. Crystal structures of [Mn(bdc(Hspar2(H2O0.25]·2H2O containing MnO6+1 capped trigonal prisms and [Cu(Hspar2](bdc·2H2O containing CuO4 squares (Hspar = sparfloxacin and bdc = benzene-1,4-dicarboxylate

    Directory of Open Access Journals (Sweden)

    Zhe An

    2016-01-01

    Full Text Available The syntheses and crystal structures of 0.25-aqua(benzene-1,4-dicarboxylato-κ2O,O′bis(sparfloxacin-κ2O,O′manganese(II dihydrate, [Mn(C8H4O4(C19H22F2N4O32(H2O0.25]·2H2O or [Mn(bdc(Hspar2(H2O0.25]·2H2O, (I, and bis(sparfloxacin-κ2O,O′copper(II benzene-1,4-dicarboxylate dihydrate, [Cu(C19H22F2N4O32](C8H4O4·2H2O or [Cu(Hspar2](bdc·2H2O, (II, are reported (Hspar = sparfloxacin and bdc = benzene-1,4-dicarboxylate. The Mn2+ ion in (I is coordinated by two O,O′-bidentate Hspar neutral molecules (which exist as zwitterions and an O,O′-bidentate bdc dianion to generate a distorted MnO6 trigonal prism. A very long bond [2.580 (12 Å] from the Mn2+ ion to a 0.25-occupied water molecule projects through a square face of the prism. In (II, the Cu2+ ion lies on a crystallographic inversion centre and a CuO4 square-planar geometry arises from its coordination by two O,O′-bidentate Hspar molecules. The bdc dianion acts as a counter-ion to the cationic complex and does not bond to the metal ion. The Hspar ligands in both (I and (II feature intramolecular N—H...O hydrogen bonds, which close S(6 rings. In the crystals of both (I and (II, the components are linked by N—H...O, O—H...O and C—H...O hydrogen bonds, generating three-dimensional networks.

  15. Crystal field and low energy excitations measured by high resolution RIXS at the L edge of Cu, Ni and Mn

    DEFF Research Database (Denmark)

    Ghiringhelli, G.; Piazzalunga, A.; Wang, X.;

    2009-01-01

    of the 3d transition metals with unprecedented energy resolution, of the order of 100 meV for Mn, Ni and Cu. We present here some preliminary spectra on CuO, malachite, NiO, , MnO and . The dd excitations are very well resolved allowing accurate experimental evaluation of 3d state energy splitting. The low...

  16. A novel metal transporter mediating manganese export (MntX regulates the Mn to Fe intracellular ratio and Neisseria meningitidis virulence.

    Directory of Open Access Journals (Sweden)

    Frédéric J Veyrier

    2011-09-01

    Full Text Available Neisseria meningitidis (Nm and N. gonorrhoeae (Ng are adapted to different environments within their human host. If the basis of this difference has not yet been fully understood, previous studies (including our own data have reported that, unlike Ng, Nm tolerates high manganese concentrations. As transition metals are essential regulators of cell growth and host pathogen interactions, we aimed to address mechanisms of Nm Mn²⁺ tolerance and its pathogenic consequences. Using bioinformatics, gene deletion and heterologous expression we identified a conserved bacterial manganese resistance factor MntX (formerly YebN. The predicted structure suggests that MntX represents a new family of transporters exporting Mn. In the Neisseria genus, this exporter is present and functional in all Nm isolates but it is mutated in a majority of Ng strains and commonly absent in nonpathogenic species. In Nm, Mn²⁺ export via MntX regulates the intracellular Mn/Fe ratio and protects against manganese toxicity that is exacerbated in low iron conditions. MntX is also important for N. meningitidis to resist killing by human serum and for survival in mice blood during septicemia. The present work thus points to new clues about Mn homeostasis, its interplay with Fe metabolism and the influence on N. meningitidis physiology and pathogenicity.

  17. A Novel Metal Transporter Mediating Manganese Export (MntX) Regulates the Mn to Fe Intracellular Ratio and Neisseria meningitidis Virulence

    Science.gov (United States)

    Veyrier, Frédéric J.; Boneca, Ivo G.; Cellier, Mathieu F.; Taha, Muhamed-Kheir

    2011-01-01

    Neisseria meningitidis (Nm) and N. gonorrhoeae (Ng) are adapted to different environments within their human host. If the basis of this difference has not yet been fully understood, previous studies (including our own data) have reported that, unlike Ng, Nm tolerates high manganese concentrations. As transition metals are essential regulators of cell growth and host pathogen interactions, we aimed to address mechanisms of Nm Mn2+ tolerance and its pathogenic consequences. Using bioinformatics, gene deletion and heterologous expression we identified a conserved bacterial manganese resistance factor MntX (formerly YebN). The predicted structure suggests that MntX represents a new family of transporters exporting Mn. In the Neisseria genus, this exporter is present and functional in all Nm isolates but it is mutated in a majority of Ng strains and commonly absent in nonpathogenic species. In Nm, Mn2+ export via MntX regulates the intracellular Mn/Fe ratio and protects against manganese toxicity that is exacerbated in low iron conditions. MntX is also important for N. meningitidis to resist killing by human serum and for survival in mice blood during septicemia. The present work thus points to new clues about Mn homeostasis, its interplay with Fe metabolism and the influence on N. meningitidis physiology and pathogenicity. PMID:21980287

  18. Synthesis, structure and physical properties of the manganese(ii) selenide/selenolate cluster complexes [Mn(32)Se(14)(SePh)(36)(PnPr(3))(4)] and [Na(benzene-15-crown-5)(C(4)H(8)O)(2)](2)[Mn(8)Se(SePh)(16)].

    Science.gov (United States)

    Eichhöfer, Andreas; Wood, Paul T; Viswanath, Raghavan N; Mole, Richard A

    2008-04-07

    The synthesis, molecular structures, and magnetic and optical properties of [Mn(32)Se(14)(SePh)(36)(PnPr(3))(4)] and [Na(benzene-15-crown-5)(C(4)H(8)O)(2)](2)[Mn(8)Se(SePh)(16)] have been investigated which are the first examples of manganese chalcogenide cluster complexes, despite known manganese oxo compounds, which comprise more than four manganese atoms.

  19. Phytoremediation of Cd, Cr, Cu, Mn, Fe, Ni, Pb and Zn from aqueous solution using Phragmites cummunis, Typha angustifolia and Cyperus esculentus.

    Science.gov (United States)

    Chandra, Ram; Yadav, Sangeeta

    2011-07-01

    A comparative bioaccumulation pattern and ultra structural changes were studied in Phragmites cummunis, Typha angustifolia and Cyperus esculentus in mixed metals solution of cadmium (Cd), chromium (Cr), copper (Cu), iron (Fe), manganese (Mn), nickel (Ni), lead (Pb) and zinc (Zn). P. cummunis was observed to be a shoot accumulator for Cr, Fe, Mn, Ni, Pb, and Zn. However, T. angustifolia was found to be a root accumulator for Cd, Cr, Cu, Fe, Ni and Pb. In addition, C. esculentus also accumulated most of the tested heavy metals in the roots, while Mn and Fe were translocated up to leaves. Further, the long term metal treatment showed maximum accumulation of all heavy metals in P. cummunis followed by T. angustifolia and C. esculentus. Among heavy metals, Fe was accumulated maximum, i.e., >1000 microg g(-1) by all three plants. Simultaneously, the adverse effects on biochemical parameters were noted earlier in C. esculentus than T. angustifolia and P. cummunis. Ultra structural observation showed the cellular changes in wetland plants after longer exposure. Results revealed that P. cummunis and T. angustifolia had more potential for tested metals than C. esculentus. This study established that these wetland plants could be used for heavy metals phytoremediation from metal containing industrial wastewater.

  20. Cu(II), Fe(III) and Mn(II) combinations as environmental stress factors have distinguishing effects on Enterococcus hirae.

    Science.gov (United States)

    Vardanyan, Zaruhi; Trchounian, Armen

    2015-02-01

    Pollution by various heavy metals as environmental stress factors might affect bacteria. It was established that iron (Fe(III)), manganese (Mn(II)) and copper (Cu(II)) ion combinations caused effects on Enterococcus hirae that differed from the sum of the effects when the metals were added separately. It was shown that the Cu2+-Fe3+ combination decreased the growth and ATPase activity of membrane vesicles of wild-type E. hirae ATCC9790 and atpD mutant (with defective FoF1-ATPase) MS116. Addition of Mn2+-Fe3+ combinations within the same concentration range had no effects on growth compared to control (without heavy metals). ATPase activity was increased in the presence of Mn2+-Fe3+, while together with 0.2 mmol/L N,N'-dicyclohexylcarbodiimide (DCCD), ATPase activity was decreased compared to control (when only 0.2 mmol/L DCCD was present). These results indicate that heavy metals ion combinations probably affect the FOF1-ATPase, leading to conformational changes. Moreover the action may be direct or be mediated by environment redox potential. The effects observed when Fe3+ was added separately disappeared in both cases, which might be a result of competing processes between Fe3+ and other heavy metals. These findings are novel and improve the understanding of heavy metals ions effects on bacteria, and could be applied for regulation of stress response patterns in the environment.

  1. Studies on Electronic Structure and Magnetic Properties of an Organic Magnet with Metallic Mn2+ and Cu2+ Ions

    Institute of Scientific and Technical Information of China (English)

    YAO Jian-Guo; PENG Guang-Xiong

    2004-01-01

    The electronic structure and the magnetic properties of the non-pure organic ferromagnetic compound MnCu(pbaOH)(H2O)3 with pbaOH = 2-hydroxy-1, 3-propylenebis (oxamato) are studied by using the density-functional theory with local-spin-density approximation. The density of states, total energy, and the spin magnetic moment are calculated. The calculations reveal that the compound MnCu(pbaOH)(H20)3 has a stable metal-ferromagnetic ground state, and the spin magnetic moment per molecule is 2.208 μB, and the spin magnetic moment is mainly from Mn ion and Cu ion. An antiferromagnetic order is expected and the antiferromagnetic exchange interaction of d-electrons of Cu and Mn passes through the antiferromagnetic interaction between the adjacent C, O, and N atoms along the path linking the atoms Cu and Mn.

  2. Size-dependent dual emission of Cu,Mn:ZnSe QDs: Controlling both emission wavelength and intensity.

    Science.gov (United States)

    Xu, Shuhong; Jiang, Han; Dong, Renjie; Lv, Changgui; Wang, Chunlei; Cui, Yiping

    2017-06-01

    Cu,Mn:ZnSe quantum dots (QDs) of tunable size, controllable photoluminescence (PL) intensity ratio and PL range were prepared. A study of the experimental conditions confirmed that the size of Cu,Mn:ZnSe QDs is affected by the pH of the solution, the speed at which the Zn solution is injected and the reaction temperature. In general, high pH, low injection speed and high reaction temperature are optimal for preparing large QDs. Based on this knowledge, different sizes of Cu,Mn:ZnSe QDs were synthesized. Moreover, white emission Cu,Mn:ZnSe QDs were designed by controlling the experimental conditions and the feeding mole ratio of Mn:Cu. Copyright © 2017 John Wiley & Sons, Ltd.

  3. THE INFLUENCE OF SEASON AND TOPOGRAPHY ON MANGANESE (Mn STATUS OF GRAZING JAVA THIN-TAILED SHEEP IN THE AGRICULTURE AREA IN MIJEN OF SEMARANG-CENTRAL JAVA

    Directory of Open Access Journals (Sweden)

    W. Widiyanto

    2014-10-01

    Full Text Available The research was aimed to study the manganese (Mn status of grazing in Java thin-tailed sheep (JTTS,its interrelation with Mn status in the forages and soil, the influence of seasonal factors and landtopography upon the status of respected mineral. Twenty male JTTS of about 6 months old and 2paddocks with field grass vegetation were used in the research. Treatment factor I was topographynamely plain and slope, while treatment factor II was season, namely dry season and rainy season. Thenumber of experimental sheep was divided into 4 groups with 5 heads of sheep for replication in eachgroup and had been grazed for 2 months. The measured variables were soil pH, Mn content in the soil,forage, feces, and blood plasma. The collected data were processed using analysis of variance withfactorial treatment pattern of 2 X 2 in completely randomized design. Mn level in blood plasma of sheepgrazed on plain and slope paddocks were 0.62 and 0.61 mg/l, respectively, in dry season whereas inrainy season were 0.68 and 0.52 mg/l, respectively. Topography did not influence the level of Mn inblood plasma in dry season. Level of Mn in blood plasma of the sheep was lowest in slope area, whereasin plain area was the highest (P<0.05. Manganese level of soil, forage, feces and blood plasma ofexperimental sheep showed the adequate Mn status.

  4. Effect of Cu surface segregation on the exchange coupling field of NiFe/FeMn bilayers

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The NiFe/FeMn bilayers with different buffer layers (Ta or Ta/Cu) were prepared by magnetron sputtering.Results show that the exchange coupling field of NiFe/FeMn films with Ta buffer is higher than that of the films with Ta/ Cu buffer. We analysed the reasons by investigating the crystallographic texture, surface roughness and surface segregation of both films, respectively. We found that the decrease of the exchange coupling fields of NiFe/FeMn films with Ta/Cu buffer layers was mainly caused by the Cu surface segregation on NiFe surface.

  5. Pilot Scale Production of Manganese Ferroalloys Using Heat-Treated Mn-Nodules

    Science.gov (United States)

    Tangstad, Merete; Ringdalen, Eli; Manilla, Edmundo; Davila, Daniel

    2016-12-01

    Pilot-scale experiments are one way to investigate the process patterns and the reaction mechanisms of processes and raw materials. To understand a process fully, both theoretical considerations as well as small-scale investigations are needed; nevertheless, the complex patterns of chemical reactions and physical phenomena can best be studied in pilot-scale investigations. After studying the chemical and mineralogical properties, the strength and the melting behavior of Mn-nodules, presented in a previous paper, the process behavior of the ore is studied in a pilot scale experiment. The industrial process is simulated in a top-and bottom-electrode furnace operated at about 150 kW. The high-strength, low-melting Mn-nodules produced by Autlan were the main raw material mixed with Comilog ore and some lime. It was shown that the Mn-nodules behave in principle like other commercial Mn-raw materials. The ore will at the border of the high-temperature area produce a liquid in coexistence with a MnO phase. As the ore is reaching the cokebed zone, the ore is already fully reduced. The ore will not be reduced much more in the cokebed area. The slag will be tapped at the composition close to the liquidus composition, as observed for other Mn-raw materials, and thus, also follow the well-known rule of lower MnO content in the slag with higher basicity.

  6. Pilot Scale Production of Manganese Ferroalloys Using Heat-Treated Mn-Nodules

    Science.gov (United States)

    Tangstad, Merete; Ringdalen, Eli; Manilla, Edmundo; Davila, Daniel

    2017-02-01

    Pilot-scale experiments are one way to investigate the process patterns and the reaction mechanisms of processes and raw materials. To understand a process fully, both theoretical considerations as well as small-scale investigations are needed; nevertheless, the complex patterns of chemical reactions and physical phenomena can best be studied in pilot-scale investigations. After studying the chemical and mineralogical properties, the strength and the melting behavior of Mn-nodules, presented in a previous paper, the process behavior of the ore is studied in a pilot scale experiment. The industrial process is simulated in a top-and bottom-electrode furnace operated at about 150 kW. The high-strength, low-melting Mn-nodules produced by Autlan were the main raw material mixed with Comilog ore and some lime. It was shown that the Mn-nodules behave in principle like other commercial Mn-raw materials. The ore will at the border of the high-temperature area produce a liquid in coexistence with a MnO phase. As the ore is reaching the cokebed zone, the ore is already fully reduced. The ore will not be reduced much more in the cokebed area. The slag will be tapped at the composition close to the liquidus composition, as observed for other Mn-raw materials, and thus, also follow the well-known rule of lower MnO content in the slag with higher basicity.

  7. Large exchange bias enhancement in (Pt(or Pd)/Co)/IrMn/Co trilayers with ultrathin IrMn thanks to interfacial Cu dusting

    Energy Technology Data Exchange (ETDEWEB)

    Vinai, G. [SPINTEC, UMR 8191 CEA/CNRS/UJF/Grenoble-INP, CEA/INAC, 17, rue des Martyrs, 38054 Grenoble (France); Crocus Technology, 4 Place Robert Schuman, 38054 Grenoble (France); Moritz, J. [Institut Jean Lamour, UMR 7198 CNRS - Université de Lorraine, Bd des Aiguillettes, BP 70239, F-54506 Vandoeuvre-les-Nancy Cedex (France); Bandiera, S. [Crocus Technology, 4 Place Robert Schuman, 38054 Grenoble (France); Prejbeanu, I. L.; Dieny, B. [SPINTEC, UMR 8191 CEA/CNRS/UJF/Grenoble-INP, CEA/INAC, 17, rue des Martyrs, 38054 Grenoble (France)

    2014-04-21

    The magnitude of exchange bias (H{sub ex}) at room temperature can be significantly enhanced in IrMn/Co and (Pt(or Pd)/Co)/IrMn/Co structures thanks to the insertion of an ultrathin Cu dusting layer at the IrMn/Co interface. The combination of trilayer structure and interfacial Cu dusting leads to a three-fold increase in H{sub ex} as compared to the conventional IrMn/Co bilayer structure, with an increased blocking temperature (T{sub B}) and a concave curvature of the temperature dependence H{sub ex}(T), ideal for improved Thermally Assisted-Magnetic Random Access Memory storage layer. This exchange bias enhancement is ascribed to a reduction of the spin frustration at the IrMn/Co interface thanks to interfacial Cu addition.

  8. Effects of magnetization on hole localization and MnO{sub 6} octahedra disorder in hole-doped lanthanum manganese perovskites

    Energy Technology Data Exchange (ETDEWEB)

    Booth, C.H.; Brosha, E.L.; Kwei, G.H. [Los Alamos National Lab., NM (United States); Bridges, F. [Univ. of California, Santa Cruz, CA (United States). Physics Dept.; Neumeier, J.J. [Florida Atlanta Univ., Boca Raton, FL (United States). Physics Dept.

    1998-12-31

    The authors review the distortions of the MnO{sub 6} octahedra reduced by magnetization in hole-doped lanthanum manganese perovskites. The systems they consider include the colossal magnetoresistance (CMR) samples La{sub 1{minus}x}Ca{sub x}MnO{sub 3} (x = 0.21, 0.25, 0.30), La{sub 0.76}Ba{sub 0.33}MnO{sub 3}, and a poorer quality La{sub 0.76}Pb{sub 0.33}MnO{sub 3} sample. They also report preliminary work on three samples of oxygen-doped LaMnO{sub 3+{delta}} and a lanthanum-deficient La{sub 0.9}MnO{sub 3} sample. They find the same exponential relationship between the removal of the distortion and the sample magnetization in the Ba- and Pb-doped CMR samples as was found previously for the Ca doped samples. The MnO{sub 6} distortion in the oxygen-doped materials is found to slightly reduce below the magnetic transition, although much less so than in the CMR samples. Above T{sub C}, the antiferromagnetic LaMnO{sub 3.006} sample shows a softer temperature dependence of the Mn-O bond length distribution broadening. Surprisingly, even this sample shows deviations from thermal (Debye) behavior near T{sub N}, possibly due to FM coupling within MnO planes.

  9. Elemental Composition and Geochemical Characteristics of Iron-Manganese Nodules in Main Soils of China

    Institute of Scientific and Technical Information of China (English)

    TAN Wen-Feng; LIU Fan; LI Yong-Hua; HU Hong-Qing; HUANG Qiao-Yun

    2006-01-01

    Elemental composition and geochemical characteristics of iron-manganese nodules from nine main soils in China were studied by chemical and multivariate statistical analyses to better understand the reactions and functions of ironmanganese nodules in soils and sediment. Compared to the corresponding soils, Mn, Ba, Cd, Co and Pb had strong accumulation, Ni had moderate accumulation, while Ca, Cu, Fe, Na, P, Sr and Zn accumulated to a minor degree in the iron-manganese nodules. In contrast, Si, Al, K, Mg and Ti were reduced in the iron-manganese nodules. The contents of Ba, Cd, Co, Cu, Ni, Pb and Zn were positively and significantly correlated with that of MnO2 in the iron-manganese nodules, while the contents of Cr, Cu, Ni, Pb and Zn were positively and significantly correlated with that of Fe2O3 in soils. Based on a principle component analysis, the elements of iron-manganese nodules were divided into four groups: 1)Mn, Ba, Cd, Co, Cu, Li, Ni, Pb and Zn that were associated with Mn oxides, 2) Fe, Cr and P that were associated with Fe oxides, 3) Si, K, and Mg that were included in the elemental composition of phyllosilicate, and 4) Ca, Na, Al and Ti that existed in todorokite, birnessite, lithiophorite and phyllosilicate. It was suggested that accumulation, mineralization and specific adsorption were involved in the formation processes of soil iron-manganese nodules.

  10. Investigation of thermal, mechanical and magnetic behaviors of the Cu-11%Al alloy with Ag and Mn additions

    Energy Technology Data Exchange (ETDEWEB)

    Silva, R.A.G., E-mail: galdino.ricardo@gmail.com [Departamento de Ciencias Exatas e da Terra-UNIFESP, Diadema-SP (Brazil); Paganotti, A.; Gama, S. [Departamento de Ciencias Exatas e da Terra-UNIFESP, Diadema-SP (Brazil); Adorno, A.T.; Carvalho, T.M.; Santos, C.M.A. [Instituto de Quimica - UNESP, Araraquara-SP (Brazil)

    2013-01-15

    The investigation of thermal, mechanical and magnetic behaviors of the Cu-11%Al, Cu-11%Al-3%Ag, Cu-11%Al-10%Mn and Cu-11%Al-10%Mn-3%Ag alloys was made using microhardness measurements, differential scanning calorimetry, X-ray diffractometry, scanning electron microscopy, energy dispersion X-ray spectroscopy and magnetic moment change with applied field measurement. The results indicated that the Mn addition changes the phase stability range, the microhardness values and makes undetectable the eutectoid reaction in annealed Cu-11%Al and Cu-11%Al-3%Ag alloys while the presence of Ag does not modify the phase transformation sequence neither microhardness values of the annealed Cu-11%Al and Cu-11%Al-10%Mn alloys, but it increases the magnetic moment of this latter at about 2.7 times and decreases the rates of eutectoid and peritectoid reactions of the former. - Highlights: Black-Right-Pointing-Pointer The microstructure of Cu-Al alloy is modified in the Ag presence. Black-Right-Pointing-Pointer ({alpha} + {gamma}) phase is stabilized down to room temperature when Ag is added to Cu-Al alloy. Black-Right-Pointing-Pointer Ag-rich phase modifies the magnetic characteristics of Cu-Al-Mn alloy.

  11. New type of Schottky diode-based Cu-Al-Mn-Cr shape memory material films

    Science.gov (United States)

    Aksu Canbay, C.; Dere, A.; Mensah-Darkwa, Kwadwo; Al-Ghamdi, Ahmed; Karagoz Genç, Z.; Gupta, R. K.; Yakuphanoglu, F.

    2016-07-01

    Cr-doped CuAlMn shape memory alloys were produced by arc melting method. The effects of Cr content on microstructure and transformation parameters of were investigated. The alloys were characterized by X-ray analysis, optical microscope observations and differential scanning calorimetry measurements. The grain size of the alloys was decreased by the addition of Cr into CuAlMn alloy system. The martensite transformation temperature was shifted both the lower temperature and higher temperature with the addition of chromium. This change was explained on the basis of the change in the thermodynamics such as enthalpy, entropy and activation energy values. The obtained results indicate that the phase transformation temperatures of the CuAlMn alloy system can be controlled by addition of Cr. We fabricated a Schottky barrier diode and observed that ideality factor and barrier height increase with increasing temperature. The diodes exhibited a thermal sensor behavior. This indicates that Schottky diode-based Cu-Al-Mn-Cr shape memory material films can be used as a sensor in high-temperature measurement applications.

  12. Photoconductivity of Polymer Composite Films Containing an Mn(III)/Cu(II) Complex

    Science.gov (United States)

    Davidenko, N. A.; Kokozay, V. N.; Petrusenko, S. R.; Stetsyuk, O. N.; Studzinsky, S. L.; Davidenko, I. I.

    2013-11-01

    We have studied the optical, photoelectric and dielectric properties of polymer composite films based on polyvinyl butyral with additives of a mixed-metal Mn(III)/Cu(II) complex. We observed high photoconductivity of the films obtained in the region of absorption by the complex. The slow photocurrent rise and relaxation kinetics are connected with the low mobility of the photogenerated charge carriers.

  13. Determination of soil micronutrients (Fe, Cu, Mn, B) extracted by Mehlich 3 using MP-AES

    Science.gov (United States)

    Krebstein, Kadri; Tõnutare, Tõnu; Rodima, Ako; Kõlli, Raimo; Künnapas, Allan; Rebane, Jaanus; Penu, Priit; Vennik, Kersti; Soobik, Liina

    2015-04-01

    The total concentration of micronutrients in soils is not a good predictor of its bioavailability and solubility. Therefore, during the decades several methods for the determination of plant availability and extractable fraction of micro- and macronutrients in soil were developed. Among several methods Mehlich 3 is the most appropriate due to its suitability for extracting soil micro- and macronutrients simultaneously. The AAS (atomic absorption spectroscopic) and ICP (inductively coupled plasma) methods are widely used for the analysis of microelements today. In 2011 the third method was added to this list with the appearance of the microwave plasma atomic emission spectrometer (MP-AES). This multielemental analytical equipment has a high potential in the soil analysis. Up to now there have been made some experiments for the use of MP-AES in soil and geological material analysis. But there is no information about the analysis of soil micronutrients extracted according to Mehlich 3 method and determined with the MP-AES. Due to the differences in atomization conditions the different emission and absorption lines are used in different instrumental methods. Therefore it is very important to choose the most suitable emission lines and the best atomization conditions. From the analytical viewpoint it is important to get coincidental results with other instrumental methods and from the agronomical point of view it is important to know the difference between AAS and ICP methods. For the experiment 51 soil samples were used. The samples were collected from A horizons of agricultural lands. The pH range was from 4.7 to 7.5 and organic matter content from 1.4 to 7.8%. The content of Mehlich 3 extractable micronutrients was determined using ICP and MP instrumental methods. The micronutrient contents ranged as follows: Fe - from 170 to 470 mg kg-1, Mn - from 5 to 190 mg kg-1, Cu - from 0.3 to 4.5 mg kg-1, B - from 0.2 to 2.1 mg kg-1. The optimal instrumental settings for iron

  14. Non-collinear magnetic structure of manganese quadruple perovskite CdMn7O12

    Science.gov (United States)

    Guo, H.; Fernández-Daz, M. T.; Zhou, L.; Yin, Y.; Long, Y.; Komarek, A. C.

    2017-01-01

    We report on the magnetic structure of CdMn7O12 determined by powder neutron diffraction. We were able to measure the magnetic structure of this Cd containing and highly neutron absorbing material by optimizing the sample geometry and by blending the CdMn7O12 with Aluminum powder. Below its Néel temperature TN1 all magnetic reflections can be indexed by a single commensurate propagation vector k = (0, 0, 1). This is different to the case of CaMn7O12 where the propagation vector is incommensurate and where an in-plane helical magnetic structure has been found. We observe a commensurate non-collinear magnetic structure in CdMn7O12 with in-plane aligned magnetic moments resembling the ones in CaMn7O12. However, the commensurate propagation vector prevents the appearance of a helical magnetic structure in CdMn7O12. Finally, we also observe a third structural phase transition below ~60 K that can be attributed to phase separation. PMID:28378833

  15. Alloyed Mn-Cu-In-S nanocrystals: a new type of diluted magnetic semiconductor quantum dots.

    Science.gov (United States)

    Liu, Qinghui; Deng, Ruiping; Ji, Xiangling; Pan, Daocheng

    2012-06-29

    A new type of Mn-Cu-In-S diluted magnetic semiconductor quantum dots was synthesized and reported for the first time. The quantum dots, with no highly toxic elements, not only show the same classic diluted magnetic behavior as Mn-doped CdSe, but also exhibit tunable luminescent properties in a relatively large window from 542 to 648 nm. An absolute photoluminescence quantum yield up to 20% was obtained after the shell growth of ZnS. This kind of magnetic/luminescent bi-functional Mn-Cu-In-S/ZnS core/shell quantum dot might serve as promising nanoprobes for use in dual-mode optical and magnetic resonance imaging techniques.

  16. Manganese nodules

    Science.gov (United States)

    Hein, James R.; Harff, Jan; Petersen, Sven; Thiede, Jorn

    2016-01-01

    The existence of manganese (Mn) nodules (Fig. 1) has been known since the late 1800s when they were collected during the Challenger expedition of 1873–1876. However, it was not until after WWII that nodules were further studied in detail for their ability to adsorb metals from seawater. Many of the early studies did not distinguish Mn nodules from Mn crusts. Economic interest in Mn nodules began in the late 1950s and early 1960s when John Mero finished his Ph.D. thesis on this subject, which was published...

  17. Rational design of coaxial structured carbon nanotube-manganese oxide (CNT-MnO2) for energy storage application

    Science.gov (United States)

    Salunkhe, Rahul R.; Ahn, Heejoon; Kim, Jung Ho; Yamauchi, Yusuke

    2015-05-01

    Recently, there has been great research interest in the development of composites (core-shell structures) of carbon nanotubes (CNTs) with metal oxides for improved electrochemical energy storage, photonics, electronics, catalysis, etc. Currently, the synthetic strategies for metal oxides/hydroxides are well established, but the development of core-shell structures by robust, cost-effective chemical methods is still a challenge. The main drawbacks for obtaining such electrodes are the very complex synthesis methods which ultimately result in high production costs. Alternatively, the solution based method offers the advantages of simple and cost effective synthesis, as well as being easy to scale up. Here, we report on the development of multi-walled carbon nanotube-manganese oxide (CNT-MnO2) core-shell structures. These samples were directly utilized for asymmetric supercapacitor (ASC) applications, where the CNT-MnO2 composite was used as the positive electrode and ZIF-8 (zeolitic imidazolate framework, ZIF) derived nanoporous carbon was used as the negative electrode. This unconventional ASC shows a high energy density of 20.44 W h kg-1 and high power density of 16 kW kg-1. The results demonstrate that these are efficient electrodes for supercapacitor application.

  18. γ-radiation Sensor Using Optical and Electrical Properties of Manganese Phthalocyanine (MnPc Thick Film

    Directory of Open Access Journals (Sweden)

    K. Arshak

    2002-05-01

    Full Text Available Manganese phthaloyanine polymer thick films were fabricated using screenprinting techniques. The optical parameters were obtained from the analysis of the absorption spectra over a wavelength range of 385-900nm. The d.c. electrical measurements were carried out in a range of 0-30 volts. The effects of γ-radiation on the optical and the electrical properties were investigated for dosimetry applications. The optical energy band gaps of these films showed a decrease in their values with the increase in the radiation dose. The electronic transition has changed from direct allowed for the as-printed films (unexposed to γ-rays to indirect allowed for the irradiated samples. Both the as-printed and irradiated Ag/MnPc/Ag devices demonstrated a Schottky conduction mechanism. Both the absorbance and the capacitance of the MnPc thick films displayed a highly consistent linear response to γ-ray exposure.

  19. Ca, Mg, Zn, Fe, Cu and Mn content of ass’s milk

    Directory of Open Access Journals (Sweden)

    Elisabetta Salimei

    2010-01-01

    Full Text Available The aim of this study was to determine Ca, Mg, Zn, Fe, Cu and Mn content of ass’s milk. Twenty four individual milk samples were collected from 4 lactating asses. During the experi- mental period milk samples were collected every 3 weeks interval, using a milking machine; asses were housed with the foals that were separated from the jennets 3 hours before milking. Milk was analysed for Ca, Mg, Zn, Fe, Cu and Mn content by atomic absorption spectrometry. The concentration mean (±SD of Ca Mg, Zn, Fe, and Cu were respectively 334.61±39.80, 58.46±8.43, 1.99±0.51, 1.15±0.52, 0.16±0.06 mg/kg. Mn was found only at trace level. Iron content of ass’s milk was the most variable ranging from 0.43 to 1.88 mg/kg. Correlation coefficients were positive and significant between Ca and Mg (r=0.63, Zn and Mg (r=0.45, Zn and Fe (r=0.49 and Zn and Cu (r=0.50. In this study, except for Fe, mean concentration of Ca, Mg, Zn, and Cu in ass’s milk was similar to those reported in literature for human milk.

  20. Differential regulation of manganese peroxidases and characterization of two variable MnP encoding genes in the white-rot fungus Physisporinus rivulosus.

    Science.gov (United States)

    Hakala, Terhi K; Hildén, Kristiina; Maijala, Pekka; Olsson, Cia; Hatakka, Annele

    2006-12-01

    Manganese peroxidase (MnP) production in the white-rot basidiomycete Physisporinus rivulosus T241i was studied. Separate MnP isoforms were produced in carbon-limited liquid media supplemented with Mn(2+), veratryl alcohol, or sawdust. The isoforms had different pH ranges for the oxidation of Mn(2+) and 2,6-dimethoxyphenol. Although lignin degradation by white-rot fungi is often triggered by nitrogen depletion, MnPs of P. rivulosus were efficiently produced also in the presence of high-nutrient nitrogen, especially in cultures supplemented with veratryl alcohol. Two MnP encoding genes, mnpA and mnpB, were identified, and their corresponding cDNAs were characterized. Structurally, the genes showed marked dissimilarity, and the expression of the two genes implicated quantitative variation and differential regulation in response to manganese, veratryl alcohol, or sawdust. The variability in regulation and properties of the isoforms may widen the operating range for efficient lignin degradation by P. rivulosus.

  1. Manganese regulates expression of manganese peroxidase by Phanerochaete chrysosporium.

    OpenAIRE

    Brown, J A; Glenn, J K; Gold, M H

    1990-01-01

    The appearance of manganese peroxidase (MnP) activity in nitrogen-limited cultures of Phanerochaete chrysosporium is dependent on the presence of manganese. Cultures grown in the absence of Mn developed normally and produced normal levels of the secondary metabolite veratryl alcohol but produced no MnP activity. Immunoblot analysis indicated that appearance of MnP protein in the extracellular medium was also dependent on the presence of Mn. Intracellular MnP protein was detectable only in cel...

  2. Electron scattering mechanisms in Cu-Mn films for interconnect applications

    Energy Technology Data Exchange (ETDEWEB)

    Misják, F.; Nagy, K. H.; Radnóczi, G. [Research Centre for Natural Sciences, Hungarian Academy of Sciences, H-1525 Budapest, P.O. Box 49, Hungary, (Hungary); Lobotka, P. [Institute of Electrical Engineering, Slovak Academy of Sciences, Dúbravská cesta 9, 841 04 Bratislava (Slovakia)

    2014-08-28

    Electrical properties and corresponding structural features of Cu-Mn alloy films with potential application as barrier and interconnect layers were studied. Cu-Mn films were deposited by DC magnetron sputtering at room temperature on SiO{sub 2} substrates. Electrical resistivity measurements were made as a function of film composition and temperature. The specific resistivity varies linearly with the Mn content showing a maximum of 205 μΩcm at 80 at. % Mn. The temperature coefficient of resistance (TCR) of all alloy films is low, showing non-metallic conductivity for most compositions. Also a minimum TCR has been observed in the 40–80 at. % Mn range which was attributed to a magnetic transformation around 200–300 K. Electrical resistivity measurements are correlated with the film structure revealed by transmission electron microscopy to clarify the phase regions throughout the composition range. In the 20–40 at. % and 70–80 at. % Mn ranges, two-phase structures were identified, where Cu- or Mn-rich solid solution grains were surrounded by a thin amorphous covering layer. Based on the revealed phase regions and morphologies electron scattering mechanisms in the system were evaluated by combining the Matthiessen's rule and the Mayadas-Schatzkes theory. Grain boundary reflectivity coefficients (r = 0.6–0.8) were calculated from fitting the model to the measurements. The proposed model indicates that, in a binary system, the special arrangement of the two phases results in new scattering mechanisms. The results are of value in optimizing the various parameters needed to produce a suitable barrier layer.

  3. Effect of MnCuFe{sub 2}O{sub 4} content on magnetic and dielectric properties of poly (O-Phenylenediamine)/MnCuFe{sub 2}O{sub 4} nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Kannapiran, Nagarajan [PG and Research Department of Chemistry, Sri Ramakrishna Mission Vidyalaya College of Arts and Science, Coimbatore 641020, Tamil Nadu (India); Muthusamy, Athianna, E-mail: muthusrkv@gmail.com [PG and Research Department of Chemistry, Sri Ramakrishna Mission Vidyalaya College of Arts and Science, Coimbatore 641020, Tamil Nadu (India); Chitra, Palanisamy [PG and Research Department of Chemistry, Sri Ramakrishna Mission Vidyalaya College of Arts and Science, Coimbatore 641020, Tamil Nadu (India)

    2016-03-01

    Poly o-phenylenediamine (PoPD)/MnCuFe{sub 2}O{sub 4} nanocomposites with three different ratios of MnCuFe{sub 2}O{sub 4} (10%, 20%, 30% w/w) were synthesized by in-situ oxidative chemical polymerization method ammonium persulphate used as oxidant, while MnCuFe{sub 2}O{sub 4} nanoparticles was prepared by auto-combustion method. The structure, morphology and magnetic properties of synthesized PoPD/MnCuFe{sub 2}O{sub 4} nanocomposites were characterized by FT-IR, UV–visible absorption spectra, X-ray diffraction (XRD), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), Thermogravimetric analysis (TGA) and Vibrating sample magnetometer (VSM). FTIR spectra and XRD were confirmed the formation of the PoPD/MnCuFe{sub 2}O{sub 4} nanocomposites. The morphology of PoPD/MnCuFe{sub 2}O{sub 4} nanocomposites is visualized through SEM and TEM. The spherical morphology of the PoPD was confirmed using SEM analysis. Dielectric properties of PoPD/MnCuFe{sub 2}O{sub 4} nanocomposites at different temperatures have been performed in the frequency range of 50 Hz–5 MHz. The optical absorption experiments of PoPD/MnCuFe{sub 2}O{sub 4} nanocomposites reveal that the direct transition with an energy band gap is around 2 eV. - Highlights: • Green synthesis of PoPD (the polymerization carried out only in aqueous medium) by in-situ chemical polymerization method. • For the first time, PoPD incorporated with MnCuFe{sub 2}O{sub 4} with lesser particle size. • The auto combustion reaction, support to achieve less particle size. • Ferrite content affects the magnetic properties of the nanocomposites.

  4. Influence of the nature and environment of manganese in Mn-BEA zeolites on NO conversion in selective catalytic reduction with ammonia.

    Science.gov (United States)

    Baran, R; Valentin, L; Krafft, J-M; Grzybek, T; Glatzel, P; Dzwigaj, S

    2017-05-31

    Manganese-containing BEA zeolites, MnxSiBEA (x = 1-4 wt%) and Mn(I.E.)AlBEA, were prepared by a two-step post-synthesis method and a conventional wet ion-exchange, respectively, and applied as catalysts in the selective catalytic reduction of NO with ammonia (NH3-SCR). The physicochemical analysis of zeolite properties by high-energy-resolution fluorescence-detected XANES (HERFD-XANES) and X-ray emission spectroscopy (XES) uncovered that the coordination, geometry and oxidation state of Mn species are strongly related to the preparation method. Additionally, the study of catalyst acidity by FTIR spectroscopy with CO and pyridine probe molecules provided important insight into the number and type of acidic centres present on the catalyst surface. The catalytic results revealed that NO conversion depended on the state and content of Mn. The zeolites obtained by the two-step post-synthesis method and with a low Mn content were very active in the medium temperature range (NO conversion ∼100%) with simultaneous high selectivity to N2 due to the presence of isolated, framework Mn(iii) and Mn(ii) species. The N2O formation was especially high in the case of catalysts containing extra-framework polynuclear Mn species and negligible in the case of Mn(I.E.)AlBEA containing predominantly isolated, extra-framework Mn(ii) species.

  5. Demetalation of Fe, Mn, and Cu chelates and complexes: application to the NMR analysis of micronutrient fertilizers.

    Science.gov (United States)

    López-Rayo, Sandra; Lucena, Juan J; Laghi, Luca; Cremonini, Mauro A

    2011-12-28

    The application of nuclear magnetic resonance (NMR) for the quality control of fertilizers based on Fe(3+), Mn(2+), and Cu(2+) chelates and complexes is precluded by the strong paramagnetism of metals. Recently, a method based on the use of ferrocyanide has been described to remove iron from commercial iron chelates based on the o,o-EDDHA [ethylenediamine-N,N'bis(2-hydroxyphenylacetic)acid] chelating agent for their analysis and quantification by NMR. The present work extended that procedure to other paramagnetic ions, manganese and copper, and other chelating, EDTA (ethylenediaminetetraacetic acid), IDHA [N-(1,2-dicarboxyethyl)-d,l-aspartic acid], and complexing agents, gluconate and heptagluconate. Results showed that the removal of the paramagnetic ions was complete, allowing us to obtain (1)H NMR spectra characterized by narrow peaks. The quantification of the ligands by NMR and high-performance liquid chromatography showed that their complete recovery was granted. The NMR analysis enabled detection and quantification of unknown impurities without the need of pure compounds as internal standards.

  6. Transformation of tetracyclines mediated by Mn(II) and Cu(II) ions in the presence of oxygen.

    Science.gov (United States)

    Chen, Wan-Ru; Huang, Ching-Hua

    2009-01-15

    Complexation of tetracyclines (TCs) with dissolved Mn(II) and Cu(II) ions were found to significantly enhance the transformation of these antibiotics in the presence of oxygen at pH 8-9.5 and pH 4-6, respectively. In the TC-Mn(II)-O2 system, oxidation of the TC-complexed Mn(II) to Mn(III) by oxygen occurs, followed by oxidation of TC by Mn(III) to regenerate Mn(II). In the TC-Cu(II)-O2 system, Cu(II) oxidizes TC within the complex and the yielded Cu(I) is reoxidized by the present oxygen. Opposite reactivity trends were observed with the two metals: OTC (oxytetracycline) > TTC (tetracycline) > iso-CTC (iso-chlorotetracycline) for the Mn(II)-mediated reaction, whereas CTC > TTC > OTC > epimers for the Cu(II)-mediated reaction. The reactivity results and examination of TC-metal ion complexation and transformation products suggest that the BCD-ring and A-ring of TC are crucial to interact with Mn(II) and Cu(II), respectively. This study highlights that the fate of TCs in aquatic environments may differ significantly by their strong interactions with different metal species present in the systems.

  7. Automated preconcentration of Fe, Zn, Cu, Ni, Cd, Pb, Co, and Mn in seawater with analysis using high-resolution sector field inductively-coupled plasma mass spectrometry.

    Science.gov (United States)

    Rapp, Insa; Schlosser, Christian; Rusiecka, Dagmara; Gledhill, Martha; Achterberg, Eric P

    2017-07-11

    A rapid, automated, high-throughput analytical method capable of simultaneous analysis of multiple elements at trace and ultratrace levels is required to investigate the biogeochemical cycle of trace metals in the ocean. Here we present an analytical approach which uses a commercially available automated preconcentration device (SeaFAST) with accurate volume loading and in-line pH buffering of the sample prior to loading onto a chelating resin (WAKO) and subsequent simultaneous analysis of iron (Fe), zinc (Zn), copper (Cu), nickel (Ni), cadmium (Cd), lead (Pb), cobalt (Co) and manganese (Mn) by high-resolution inductively-coupled plasma mass spectrometry (HR-ICP-MS). Quantification of sample concentration was undertaken using isotope dilution for Fe, Zn, Cu, Ni, Cd and Pb, and standard addition for Co and Mn. The chelating resin is shown to have a high affinity for all analyzed elements, with recoveries between 83 and 100% for all elements, except Mn (60%) and Ni (48%), and showed higher recoveries for Ni, Cd, Pb, Co and Mn in direct comparison to an alternative resin (NOBIAS Chelate-PA1). The reduced recoveries for Ni and Mn using the WAKO resin did not affect the quantification accuracy. A relatively constant retention efficiency on the resin over a broad pH range (pH 5-8) was observed for the trace metals, except for Mn. Mn quantification using standard addition required accurate sample pH adjustment with optimal recoveries at pH 7.5 ± 0.3. UV digestion was necessary to increase recovery of Co and Cu in seawater by 15.6% and 11.4%, respectively, and achieved full break-down of spiked Co-containing vitamin B12 complexes. Low blank levels and detection limits could be achieved (e.g., 0.029 nmol L(-1) for Fe and 0.028 nmol L(-1) for Zn) with the use of high purity reagents. Precision and accuracy were assessed using SAFe S, D1, and D2 reference seawaters, and results were in good agreement with available consensus values. The presented method is ideal for

  8. Combined Electron Paramagnetic Resonance and Atomic Absorption Spectroscopy/Inductively Coupled Plasma Analysis As Diagnostics for Soluble Manganese Species from Mn-Based Positive Electrode Materials in Li-ion Cells.

    Science.gov (United States)

    Shilina, Yuliya; Ziv, Baruch; Meir, Aviv; Banerjee, Anjan; Ruthstein, Sharon; Luski, Shalom; Aurbach, Doron; Halalay, Ion C

    2016-04-19

    Manganese dissolution from positive electrodes significantly reduces the durability of lithium-ion batteries. Knowledge of dissolution rates and oxidation states of manganese ions is essential for designing effective mitigation measures for this problem. We show that electron paramagnetic resonance (EPR) combined with atomic absorption spectroscopy (AAS) or inductively coupled plasma (ICP) can determine both manganese dissolution rates and relative Mn(3+) amounts, by comparing the correlation between EPR and AAS/ICP data for Mn(2+) standards with that for samples containing manganese cations dissolved from active materials (LiMn2O4 (LMO) and LiNi(0.5)Mn(1.5)O4 (LNMO)) into the same electrolyte solution. We show that Mn(3+), and not Mn(2+), is the dominant species dissolved from LMO, while Mn(2+) is predominant for LNMO. Although the dissolution rate of LMO varies significantly for the two investigated materials, due to particle morphology and the presence of Cr in one of them, the Mn speciation appears independent of such details. Thus, the relative abundance of dissolved manganese ions in various oxidation states depends mainly on the overall chemical identity of the active material (LMO vs LNMO). We demonstrate the relevance of our methodology for practical batteries with data for graphite-LMO cells after high-temperature cycling or stand at 4.2 V.

  9. The molecular characterizations of Cu/ZnSOD and MnSOD and its responses of mRNA expression and enzyme activity to Aeromonas hydrophila or lipopolysaccharide challenge in Qihe crucian carp Carassius auratus.

    Science.gov (United States)

    Kong, Xianghui; Qiao, Dan; Zhao, Xianliang; Wang, Li; Zhang, Jie; Liu, Dandan; Zhang, Hongxu

    2017-08-01

    Superoxide dismutases (SODs), as the prime antioxidant enzymes, present the first line of defense against oxidative stress caused by excessive reactive oxygen species (ROS) in organism. In the study, two distinct members of SOD family were cloned and analyzed in Qihe crucian carp Carassius auratus (designated as CaCu/ZnSOD and CaMnSOD, respectively). The full-length cDNA of CaCu/ZnSOD is 759 bp, containing a 5' -untranslated region (UTR) of 39 bp, a ORF (including stop codon, TAG) of 465 bp and a 3'-UTR of 255 bp. The ORF of CaCu/ZnSOD encodes a protein of 154 amino acids (aa), in which, two Cu/ZnSOD signature ((45)GFHVHAFGDNT(55) and (139)GNAGGRLACGVI(150)) and four conserved amino acids for Cu/Zn(2+)-binding sites (H64, H72, H81 and D84) were observed. The full-length CaMnSOD cDNA (960 bp) consists of a 5'-UTR of 114 bp, a ORF of 675 bp and a 3'-UTR of 231 bp, the ORF of CaMnSOD encodes a 224 aa protein with a 26 aa mitochondrial-targeting sequence (MTS) in the N-terminus, and four conserved amino acids for manganese binding (H52, H100, D185 and H189) were observed. Multiple alignment and the structural analysis revealed two Cu/ZnSOD signature motifs and a MnSOD signature motif as well as the invariant binding sites for Cu(2+)/Zn(2+) in CaCu/ZnSOD and Mn(2+) in CaMnSOD. The phylogenetic analysis indicated that CaCu/ZnSOD was homologous to cytosolic Cu/ZnSODs, and CaMnSOD was high similarity with mitochondrial MnSODs from other fish. The tissue distribution analysis demonstrated that CaCu/ZnSOD and CaMnSOD were highly expressed in liver, heart and muscle. The dynamic expressions of CaCu/ZnSOD and CaMnSOD were observed after the challenges with Aeromonas hydrophila or LPS, which generally increased in liver, gill, kidney and spleen, while, the mRNA expressions were down-regulated at some time points in head kidney. The enzyme activities increased after A. hydrophila or LPS challenge, compared to the control. In this study, the molecular structures and functional

  10. Mobilization of manganese by basalt associated Mn(II)-oxidizing bacteria from the Indian Ridge System

    Digital Repository Service at National Institute of Oceanography (India)

    Sujith, P.P.; Mourya, B.S.; Krishnamurthi, S.; Meena, R.M.; LokaBharathi, P.A.

    %) after growth for detecting amylase activity. The hydrolysis of starch and tributyrin was observed as clear halos surrounding the colony. Similarly, screening for cellulase producers was on carboxymethylcellulose (CMC) agar (0.2% NaNO3, 0.1% K2HPO4, 0.... Solubilization of manganese from ores by heterotrophic micro-organisms. Hydrometallurgy 29,131-144. Bairagi, A., Ghosh, K., Sen, S.K., Ray, A.K., 2002. Enzyme producing bacterial flora isolated from fish digestive tracts. Aquacult. Int. 10, 109-121. Boone, D...

  11. Structural and magnetic modulations in CaCu(x)Mn(7 - x)O(12).

    Science.gov (United States)

    Sławiński, W; Przeniosło, R; Sosnowska, I; Bieringer, M

    2010-05-12

    Low temperature atomic position modulations and magnetic moment modulations are reported for CaCu(x)Mn(7 - x)O(12) (x = 0.0, 0.1 and 0.23) using neutron powder diffraction. Both modulations are described with propagation vectors (0, 0, q) parallel to the c-axis in the hexagonal setting. The present neutron diffraction studies confirm the quantitative model describing the atomic position modulations in CaCu(x)Mn(7 - x)O(12) (x = 0.0 and 0.1) as derived from synchrotron based powder x-ray diffraction studies (Sławiński et al 2009 Acta Crystallogr. B 65 535). Neutron diffraction studies confirm the relation between the atomic position modulation length L(p) and the magnetic modulation length L(m) = 2L(p) between 50 K and the Néel temperature T(N). CaCu(x)Mn(7 - x)O(12) (x = 0.1 and 0.23) shows a magnetic phase transition near 50 K associated with considerable changes of the magnetic modulation length and the magnetic coherence length, similar to that observed in the parent CaMn(7)O(12).

  12. Mn(II) and Cu(II) complexes of a bidentate Schiff's base ligand: Spectral, thermal, molecular modelling and mycological studies

    Science.gov (United States)

    Tyagi, Monika; Chandra, Sulekh; Tyagi, Prateek

    2014-01-01

    Complexes of manganese(II) and copper(II) of general composition M(L)2X2 have been synthesized [L = 2-acetyl thiophene thiosemicarbazone and X = Cl- and NO3-]. The elemental analysis, molar conductance measurements, magnetic susceptibility measurements, mass, IR, UV, NMR and EPR spectral studies of the compounds led to the conclusion that the ligand acts as a bidentate manner. The Schiff's base ligand forms hexacoordinated complexes having octahedral geometry for Mn(II) and tetragonal geometry for Cu(II) complexes. The thermal studies suggested that the complexes are more stable as compared to ligand. In molecular modelling the geometries of Schiff's base and metal complexes were fully optimized with respect to the energy using the 6-31g(d,p) basis set. The mycological studies of the compounds were examined against the plant pathogenic fungi i.e. Rhizoctonia bataticola, Macrophomina phaseolina, Fusarium odum.

  13. Concentrations of Mn, Fe, Cu, Zn, Cr, Cd, Pb, Ni in selected Nigerian tubers, legumes and cereals and estimates of the adult daily intakes.

    Science.gov (United States)

    Akinyele, I O; Shokunbi, O S

    2015-04-15

    This study was designed to determine the levels of microminerals (manganese (Mn), iron (Fe), copper (Cu), zinc (Zn), chromium (Cr)) and heavy metals (cadmium (Cd), lead (Pb) and nickel (Ni)) in some tubers, legumes and cereals obtained from the markets in Abeokuta city, South-West Nigeria. The food samples were digested by dry ashing procedure and their minerals were determined by atomic absorption spectrophotometer. The results show mean values of 1.67-32.00, 7.25-61.58, 1.59-10.56, 6.65-46.99, 0.02-0.58, legumes and cereals from various parts of the world. The daily intakes of the metals through tubers, legumes and cereals were found to be lower than the provisional tolerable daily intakes proposed by Joint FAO/WHO Expert Committee on Food Additives.

  14. The role of annealing temperature and bio template (egg white) on the structural, morphological and magnetic properties of manganese substituted MFe{sub 2}O{sub 4} (M=Zn, Cu, Ni, Co) nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Ranjith Kumar, E. [Department of Physics, Nanotechnology Laboratory, Sri Ramakrishna Mission Vidyalaya College of Arts and Science, Coimbatore 641020, Tamil Nadu (India); Jayaprakash, R., E-mail: ranjueaswar@gmail.com [Department of Physics, Nanotechnology Laboratory, Sri Ramakrishna Mission Vidyalaya College of Arts and Science, Coimbatore 641020, Tamil Nadu (India); Kumar, Sanjay [Department of Physics, B.R. Ambedkar Bihar University, Muzaffarpur 842001, Bihar (India)

    2014-02-15

    Manganese substituted ferrites (ZnFe{sub 2}O{sub 4}, CuFe{sub 2}O{sub 4}, NiFe{sub 2}O{sub 4} and CoFe{sub 2}O{sub 4}) have been prepared in the bio template medium by using a simple evaporation method. The annealing temperature plays an important position on changing particle size and morphology of the mixed ferrite nanoparticles were found out by X-ray diffraction, transmission electron microscopy and scanning electron microscopy methods. The role of manganese substitution in the mixed ferrite nanoparticles were also analyzed for different annealing temperature. The substitution of Mn also creates a vital change in magnetic properties which is studied by using vibrating sample magnetometer (VSM). These spinel ferrites are decomposed to α-Fe{sub 2}O{sub 3} after annealing above 550 °C in air. However, α-Fe{sub 2}O{sub 3} phase was slowly vanished after ferrites annealing above 900 °C. The effect of this secondary phase on the structural change and magnetic properties of the mixed ferrite nanoparticles is discussed. - Highlights: • The egg white support to achieve sample with shorter reaction time. • The high value of magnetization obtained by the influence of manganese. • Nature of the ferrites was affected with increasing annealing temperature.

  15. Synthesis and Electrochemical Characterization of M2Mn3O8 (M=Ca,Cu) Compounds and Derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Park, Yong Joon; Doeff, Marca M.

    2005-08-25

    M{sub 2}Mn{sub 3}O{sub 8} (M=Ca{sup 2+}, Cu{sup 2+}) compounds were synthesized and characterized in lithium cells. The M{sup 2+} cations, which reside in the van der Waal's gaps between adjacent sheets of Mn{sub 3}O{sub 8}{sup 4-}, may be replaced chemically (by ion-exchange) or electrochemically with Li. More than 7 Li{sup +}/Cu{sub 2}Mn{sub 3}O{sub 8} may be inserted electrochemically, with concomitant reduction of Cu{sup 2+} to Cu metal, but less Li can be inserted into Ca{sub 2}Mn{sub 3}O{sub 8}. In the case of Cu{sup 2+}, this process is partially reversible when the cell is charged above 3.5 V vs. Li, but intercalation of Cu{sup +} rather than Cu{sup 2+} and Li{sup +}/Cu{sup +} exchange occurs during the subsequent discharge. If the cell potential is kept below 3.4 V, the Li in excess of 4Li{sup +}/Cu{sub 2}Mn{sub 3}O{sub 8} can be cycled reversibly. The unusual mobility of +2 cations in a layered structure has important implications both for the design of cathodes for Li batteries and for new systems that could be based on M{sup 2+} intercalation compounds.

  16. Investigation of electronic structure, magnetic and transport properties of half-metallic Mn2CuSi and Mn2ZnSi Heusler alloys

    Science.gov (United States)

    Bhat, Idris Hamid; Yousuf, Saleem; Mohiuddin Bhat, Tahir; Gupta, Dinesh C.

    2015-12-01

    The electronic and magnetic properties of Mn2CuSi and Mn2ZnSi Heusler alloys have been investigated using full-potential linearized augmented plane wave method. The optimized equilibrium lattice parameters in stable F-43m configuration are found to be 5.75 Å for Mn2CuSi and 5.80 Å for Mn2ZnSi. Spin-resolved calculations show that the Mn atoms at inequivalent Wyckoff positions have different contributions to the total magnetic moment in the unit cell. The anti-parallel magnetic moments of inequivalent Mn atoms sum to an integer with total magnetic moment per unit cell. The 100% spin-polarization at Fermi energy together with the total magnetic moment of 1.0 μB for Mn2CuSi and 2.0 μB for Mn2ZnSi per unit cell, predict that the materials follow MT=ZT - 28 Slater-Pauling rule. Both the materials under study exhibit half-metallicity with an energy gap in the spin-down channels. In the study, we predict a rather fine value of Seebeck coefficient. Further, the decreasing electrical conductivity with temperature shows a metallic character in spin-up configurations, while the electrical conductivity of spin-down states follows a semiconductor-like trend.

  17. Solid-state production of lignin peroxidase (LiP) and manganese peroxidase (MnP) by Phanerochaete chrysosporium using steam-exploded straw as substrate.

    Science.gov (United States)

    Fujian, X; Hongzhang, C; Zuohu, L

    2001-11-01

    In the used media mainly consisting of steam-exploded wheat straw, the straw, which could replace expensive veratryl alcohol, might act not only as nutrient, but also as inducer of lignin enzymes. The activities of the enzymes lignin peroxidase (LiP) and manganese peroxidase (MnP) in solid-state fermentation (SSF) were far higher than in submerged fermentation (SmF). Under optimal conditions of SSF, the maximum activities of the enzymes Lip and MnP were 2600 and 1375 U/L, respectively. Thus, this would pave the way for production and application of lignin enzymes on a large scale.

  18. Cr, Cu, Mn, Mo, Ni, and Steel Price Drivers

    Science.gov (United States)

    Papp, John F.; Corathers, Lisa A.; Edelstein, Daniel L.; Fenton, Michael D.; Kuck, Peter H.; Magyar, Michael J.

    2007-01-01

    Summary This report contains the 55 slide images from a presentation made by the author at the meeting of the Metal Powder Industries Federation held in Denver, CO, on May 15, 2007. The Metal Powder Industries Federation (MPIF) invited the U.S. Geological Survey (USGS) to speak at their annual meeting about the price drivers for chromium, copper, manganese, molybdenum, nickel, and steel. These metals are of interest to MPIF because the prices of these raw materials used by their industry were at historically high levels. Because the USGS closely monitors, yet neither buys nor sells, metal commodities, it is an unbiased source of metal price information and analysis. The authors used information about these and other metals collected and published by the USGS (U.S. production, trade, stocks, and prices) and about consumption and stocks internationally by country from industry organizations that publish such information, because metal markets are influenced by activities and events over the entire globe. By seeking a common cause for common behavior among the various metal commodities, the authors found that major price drivers on metal commodities were inflation, major international events such as wars and recessions, and major national events such as the dissolution of the Soviet Union in 1991 and economic growth in China, which started with the open door policy in the 1970s but did not have significant market impact until starting in the 1990s. Metal commodity prices also responded to commodity-specific events.

  19. Structure and magnetic properties of a three-dimensional framework manganese(II) phosphate, [NH 4][Mn 4(PO 4) 3

    Science.gov (United States)

    Neeraj, S.; Noy, Maria L.; Cheetham, Anthony K.

    2002-03-01

    A new three-dimensional manganese(II) phosphate with one-dimensional channels, [NH 4][Mn 4(PO 4) 3], has been synthesized hydrothermally and characterized by single-crystal X-ray diffraction and magnetic measurements. The compound crystallizes in the orthorhombic space group Pnnm (No. 58) with a=9.8856(17), b=16.745(4), c=6.4639(9) Å; V=1070.0(3) Å 3; Z=8. The anionic framework is formed by manganese phosphate layers (formed from MnO 5 square-pyramids and PO 4 tetrahedra), linked together by MnO 5 and MnO 6 polyhedra and PO 4 tetrahedra. One-dimensional channels containing ammonium ions are formed along the crystallographic a-axis. The compound is closely related to a potassium-containing Mn(II) phosphate. Magnetic susceptibility measurements from room temperature to 2.5 K point to ferrimagnetic ordering at Tc˜17 K.

  20. Room-Temperature Energy-Sampling Kβ X-ray Emission Spectroscopy of the Mn4Ca Complex of Photosynthesis Reveals Three Manganese-Centered Oxidation Steps and Suggests a Coordination Change Prior to O2 Formation.

    Science.gov (United States)

    Zaharieva, Ivelina; Chernev, Petko; Berggren, Gustav; Anderlund, Magnus; Styring, Stenbjörn; Dau, Holger; Haumann, Michael

    2016-08-01

    In oxygenic photosynthesis, water is oxidized and dioxygen is produced at a Mn4Ca complex bound to the proteins of photosystem II (PSII). Valence and coordination changes in its catalytic S-state cycle are of great interest. In room-temperature (in situ) experiments, time-resolved energy-sampling X-ray emission spectroscopy of the Mn Kβ1,3 line after laser-flash excitation of PSII membrane particles was applied to characterize the redox transitions in the S-state cycle. The Kβ1,3 line energies suggest a high-valence configuration of the Mn4Ca complex with Mn(III)3Mn(IV) in S0, Mn(III)2Mn(IV)2 in S1, Mn(III)Mn(IV)3 in S2, and Mn(IV)4 in S3 and, thus, manganese oxidation in each of the three accessible oxidizing transitions of the water-oxidizing complex. There are no indications of formation of a ligand radical, thus rendering partial water oxidation before reaching the S4 state unlikely. The difference spectra of both manganese Kβ1,3 emission and K-edge X-ray absorption display different shapes for Mn(III) oxidation in the S2 → S3 transition when compared to Mn(III) oxidation in the S1 → S2 transition. Comparison to spectra of manganese compounds with known structures and oxidation states and varying metal coordination environments suggests a change in the manganese ligand environment in the S2 → S3 transition, which could be oxidation of five-coordinated Mn(III) to six-coordinated Mn(IV). Conceivable options for the rearrangement of (substrate) water species and metal-ligand bonding patterns at the Mn4Ca complex in the S2 → S3 transition are discussed.

  1. Bioavailability of Cu, Zn and Mn from Mineral Chelates or Blends of Inorganic Salts in Growing Turkeys Fed with Supplemental Riboflavin and/or Pyridoxine.

    Science.gov (United States)

    Salami, S A; Oluwatosin, O O; Oso, A O; Fafiolu, A O; Sogunle, O M; Jegede, A V; Bello, F A; Pirgozliev, V

    2016-09-01

    An 84-day feeding trial was conducted in growing turkeys to measure the bioavailability of Cu, Zn and Mn from a commercial mineral chelate and corresponding inorganic salts in composite feeds containing supplemental riboflavin (B2) and/or pyridoxine (B6). A total of 320, 28-day-old British United Turkeys (BUT) were assigned to eight dietary treatments in a 2 × 4 factorial arrangement comprising two trace mineral sources: chelated trace mineral blend (CTMB) and its corresponding inorganic trace minerals blend (ITMB) fed solely or with supplements of vitamin B2 (8 ppm) or B6 (7 ppm) or 8 ppm B2 + 7 ppm B6. Each treatment was replicated four times with 10 turkeys each. It was observed that turkeys fed with diets supplemented solely with ITMB elicited higher (P < 0.05) Zn excretion than their counterparts fed with diets containing ITMB with supplements of vitamins B2 and/or B6. Manganese retention was lower (P < 0.05) in turkeys fed with diets supplemented solely with ITMB than those fed with diets containing vitamins B2 and/or B6 additives. Combination of CTMB or ITMB with B6 improved (P < 0.05) the concentration of Mn in the liver and Cu in the bone. It was concluded that the minerals in CTMB were more available to the animals than ITMB. Furthermore, vitamins B2 and/or B6 supplementation improved the bioavailability of the inorganic Cu, Zn and Mn in growing turkeys and tended to reduce the concentration of these trace elements in birds' excreta.

  2. Structural, optical, dielectric and antibacterial studies of Mn doped Zn0.96Cu0.04O nanoparticles.

    Science.gov (United States)

    Sangeetha, R; Muthukumaran, S; Ashokkumar, M

    2015-06-05

    Zn(0.96-x)Cu0.04Mn(x)O (0⩽x⩽0.04) nanoparticles were synthesized by sol-gel method. The X-ray diffraction pattern indicated that doping of Mn and Cu did not change the ZnO hexagonal wurtzite structure. The Mn doped nanoparticles had smaller average crystallite size than un-doped Zn0.96Cu0.04O nanoparticles due to the distortion in the host ZnO lattice. This distortion prevented the subsequent growth and hence the size reduced by Mn doping. The changes in lattice parameters, average crystallite size, peak position and peak intensity confirmed the Mn substitution in Zn-Cu-O lattice. The Mn and Cu co-doping increased the charge carrier density in ZnO nanoparticles which led to increase the dielectric constant. The dielectric constant also varied by depend the size of the nanoparticles. The change in morphology by Mn-doping was studied by transmission electron microscope. The optical absorption and band gap were changed with respect to both compositional and size effects. The band gap was initially increased from 3.65 to 3.73 eV at 1% of Mn doping, while decreasing trend in band gap was noticed for further increase of Mn. The band gap was decreased from 3.73 to 3.48 eV when Mn concentration was increased from 2% to 4%. Presence of chemical bonding and purity of the nanoparticles were confirmed by FTIR spectra. The antibacterial study revealed that that the antibacterial activity of Zn0.96Cu0.04O is enhanced by Mn doping.

  3. Health Risk Assessment of Fe, Mn, Cu, Cr in Drinking Water in some Wells and Springs of Shush and Andimeshk, Khuzestan Province, Southern Iran

    Directory of Open Access Journals (Sweden)

    Mohamad Sakizadeh

    2016-02-01

    Full Text Available Background: In the current study,the hazard quotient, the hazard index (HI and spatial variations of Fe,Mn,Cu and Cr in drinking water sources of Andimesk-Shush, Khuzestan Province, Southern Iranaquifer were assessed. Methods: We compared theconcentrations of aforementioned heavy metals in wells and springs inAndimeshk and Shush regions. The non-carcinogenic risk assessment of heavy metals was implemented usingUnited States Environmental Protection Agency (USEPA index.The spatial maps in the area were developed by geostatistical methods. Results: Mean concentrations of heavy metals in groundwater sources of the study area in decreasing order was as follows: Cu >Mn> Fe> Cr. Except for iron,mean heavy metal concentrations were higher than the standard levels. Manganese concentration in 41.5% of the samples exceeded the permissible limits. Copper was higher than the safety limit in 74% of the samples, and chromium in 54% of the cases. The spatial pattern of heavy metals concentrations indicated higher concentrations in the southern parts of the region. The mean hazard quotients of most samples for the four heavy metals were lower than one, indicating that there was no immediate threat due to the exposure to these heavy metals. The calculated accumulated hazards of these heavy metals produced different results, with hazard indices of higher than one. Conclusion: The accumulated hazard indicesfor the evaluated metals were higher than one, indicating that chronic ingestion of these waters threatens the health of local consumers on the long run.

  4. Ship-Borne Geochemical Investigations of Deep-Sea Manganese-Nodule Deposits in the Pacific Using a Radioisotope Energy-Dispersive X-Ray System

    DEFF Research Database (Denmark)

    Friedrich, G.H.W.; Kunzendorf, Helmar; Plüger, W.L.

    1974-01-01

    ) detector with a measured energy resolution of 195 eV for Mn Kα X-rays, standard nuclear electronics, a 1024-channel analyser and a data read-out unit. The X-ray spectra in the manganese-nodule samples were excited by a 30-mCi 238Pu source. The six elements Mn, Fe, Co, Ni, Cu and Zn were analysed on board......, 0.23% Co, 1.16% Ni, 0.94% Cu and 0.10% Zn. The average content of the base metals expressed as the sum of the Co, Ni, Cu and Zn contents was 2.48%. A linear relationship between Mn and Ni in all analysed samples, including whole manganese-nodule samples, zones of manganese nodules and manganese...

  5. Synthesis, structural investigation and thermal properties of a novel manganese complex Mn2(DAT)2Cl4(H2O)4 (DAT=1,5-diaminotetrazole).

    Science.gov (United States)

    Zhang, Jian-Guo; Li, Zhi-Min; Zang, Yan; Zhang, Tong-Lai; Shu, Yuan-Jie; Yang, Li; Power, Philip P

    2010-06-15

    A novel manganese complex Mn(2)(DAT)(2)Cl(4)(H(2)O)(4), where DAT is 1,5-diaminotetrazole, was synthesized by the reaction of manganese(II) chloride tetrahydrate and 1,5-diaminotetrazole (DAT) in ethanol, and characterized by elemental analysis, FT-IR spectroscopy. The crystal structure was determined through X-ray single crystal diffraction. The molecular unit of Mn(2)(DAT)(2)Cl(4)(H(2)O)(4) has a distorted octahedral structure, containing two central manganese cations, which coordinated by a mono-dentate terminal chloride, a bulky DAT ligand and two water molecules, and linked by two bidentate bridging chloride ligands. There are two main exothermic peaks and one endothermic peak in the thermal decomposition process, investigated by differential scanning calorimetry (DSC) and thermo-gravimetric analysis (TGA), the final residue of the title compound at 600 degrees C is MnO. The kinetic parameters of the endothermic process and two main exothermic processes were studied by applying the Kissinger's and Ozawa-Doyle's methods.

  6. Microstructural Changes in a High-Manganese Austenitic Fe-Mn-Al-C Steel

    Directory of Open Access Journals (Sweden)

    Witkowska M.

    2014-10-01

    Full Text Available Microstructural changes in the age-hardenable Fe-28wt.%Mn-9wt.%Al-1wt.%C steel during ageing at 550°C for various times have been investigated by transmission electron microscopy (TEM and X-ray diffraction (XRD. The steel was produced in an induction furnace and the ingot, after homogenization at 1150°C for 3 hours under a protective argon atmosphere, was hot-rolled and subsequently cold-rolled up to 23% reduction. The sheet was then aged at 550°C for various times in an argon atmosphere and cooled in air. XRD analysis and TEM observations revealed a modulated structure and superlattice reflections produced by spinodal decomposition, which occurred during ageing at 550°C. Theexistence of satellites suggests that either (Fe, Mn3AlCx carbides were formed within the austenite matrix by spinodal decomposition during cooling or chemical fluctuactions occurred between the (Fe, Mn3AlCx carbides and the austenitic matrix.

  7. Gender influence on manganese induced depression-like behavior and Mn and Fe deposition in different regions of CNS and excretory organs in intraperitoneally exposed rats.

    Science.gov (United States)

    Yamagata, A T; Guimarães, N C; Santana, D F; Gonçalves, M R; Souza, V C O; Barbosa Júnior, F; Pandossio, J E; Santos, V S

    2017-02-01

    Manganese (Mn) is an essential metal for mammals. It can modulate the action of endogenous substances, as neurotransmitters, but in excess also can trigger known neurotoxic effects. Many studies have been conducted assessing Mn neurotoxicity. However, Mn bioaccumulation in different brain tissues and behavior effects involving gender-specific studies are conflicted in the literature. Therefore, the aim of this work was to compare Mn effects, after 30days of intraperitoneal treatment, in male and female rats, submitted to forced swim and open field tests. After that, were evaluated Mn and Fe tissue levels in CNS, liver, and kidneys. Wistar rats were divided into saline, Mn 1mg/kg, Mn 5mg/kg, and imipramine (as forced swim control). Then, animals were euthanized by anesthesia overdose followed by decapitation and the collected tissue were striatum, hippocampus, brainstem, cortex, cerebellum, hepatic tissue, and renal tissue. Mn and Fe were determined by ICP-MS. There was a dose-dependent effect on accumulation of Mn in the cerebellum and brainstem to the dosage of 5mg/kg. In hippocampus there were bioaccumulation differences between gender and dose, and an increase of Fe in the groups exposed to Mn. Excess metals in the brain dissected has a strong influence on memory and learning processes and suggests pro-depressive effects, possibly triggered by the reduction of monoamines due to excessive metal bioaccumulation. It was concluded that, under this experimental design, Mn exposure cause metal deposition on dissected CNS, liver and kidney. There an effect at lower doses that was gender-dependent and males had more pronounced behavioral damage compared to females, although with increasing dose, females had an indication of motor damage. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  8. Kinetic and redox properties of MnP II, a major manganese peroxidase isoenzyme from Panus tigrinus CBS 577.79.

    Science.gov (United States)

    Petruccioli, Maurizio; Frasconi, Marco; Quaratino, Daniele; Covino, Stefano; Favero, Gabriele; Mazzei, Franco; Federici, Federico; D'Annibale, Alessandro

    2009-11-01

    A manganese peroxidase (MnP) isoenzyme from Panus tigrinus CBS 577.79 was produced in a benchtop stirred-tank reactor and purified to apparent homogeneity. The purification scheme involving ultrafiltration, affinity chromatography on concanavalin-A Sepharose, and gel filtration led to a purified MnP, termed "MnP II," with a specific activity of 288 IU mg(-1) protein and a final yield of 22%. The enzyme turned out to be a monomeric protein with molecular mass of 50.5 kDa, pI of 4.07, and an extent of N-glycosylation of about 5.3% of the high-mannose type. The temperature and pH optima for the formation of malonate manganic chelates were 45 degrees C and 5.5, respectively. MnP II proved to be poorly thermostable at 50 and 60 degrees C, with half-lives of 11 min and 105 s, respectively. K (m) values for H(2)O(2) and Mn(2+) were 16 and 124 microM, respectively. Although MnP II was able to oxidize veratryl alcohol and to catalyze the Mn(2+)-independent oxidation of several phenols, it cannot be assigned to the versatile peroxidase family. As opposed to versatile peroxidase oxidation, veratryl alcohol oxidation required the simultaneous presence of H(2)O(2) and Mn(2+); in addition, low turnover numbers and K (m) values higher than 300 microM characterized the Mn(2+)-independent oxidation of substituted phenols. Kinetic properties and the substrate specificity of the enzyme markedly differed from those reported for MnP isoenzymes produced by the reference strain P. tigrinus 8/18. To our knowledge, this study reports for the first time a thorough electrochemical characterization of a MnP from this fungus.

  9. Structure and electrical properties of Cu-doped Mn-Co-O spinel prepared via soft chemistry and its application in intermediate-temperature solid oxide fuel cell interconnects

    Science.gov (United States)

    Brylewski, T.; Kruk, A.; Bobruk, M.; Adamczyk, A.; Partyka, J.; Rutkowski, P.

    2016-11-01

    The study describes CuxMn1.25-0.5xCo1.75-0.5xO4 (x = 0, 0.1, 0.3 and 0.5) spinels synthesized using EDTA gel processes in order to optimize the performance of high-quality spinel protective-conducting films deposited on steel interconnects. The powders obtained after 12 h of calcination in air at 1073 K are solely cubic spinels. Sintering these spinels for 12 h in air at 1423 K also leads to the formation of small amounts of CoO, Mn2O3 or CuO; the type of phase depends on the quantity of copper introduced into the manganese-cobalt lattice. The highest electrical conductivity at 1073 K is observed for Cu0.3Mn1.1Co1.6O4 (162 S·cm-1), which is closely correlated with the lowest activation energy of conduction over the entire temperature range (373≤T≤1073 K); the lowest conductivity is measured for Mn1.25Co1.75O4 (84 Sṡcm-1). The study confirms the suitability of the Cu0.3Mn1.1Co1.6O4 spinel as a potential material for the preparation of protective-conducting coatings on the surface of the DIN 50049 ferritic steel applied in IT-SOFC interconnects. The area-specific resistance of coated steel is 0.08 Ω·cm2, which is lower than that of bare steel after 300 h of oxidation at 1073 K. Cr vaporization tests show that the Cu0.3Mn1.1Co1.6O4 coating is efficient at blocking the outward diffusion of chromium.

  10. Effect of alloying elements on branching of primary austenite dendrites in Ni-Mn-Cu cast iron

    National Research Council Canada - National Science Library

    A. Janus

    2011-01-01

    Within the research, determined were direction and intensity of influence of individual alloying elements on branching degree of primary austenite dendrites in austenitic cast iron Ni-Mn-Cu. 30 cast shafts dia...

  11. Cavitation Erosion Behavior of as-Welded Cu12Mn8Al3Fe2Ni Alloy

    Institute of Scientific and Technical Information of China (English)

    Xiaoya LI; Yonggui YAN; Zhenming XU; Jianguo LI

    2004-01-01

    Cavitation erosion behavior of as-welded Cu12Mn8Al3Fe2Ni alloy in 3.5% NaCl aqueous solution was studied by magnetostrictive vibratory device for cavitation erosion. The results show that the cavitation erosion resistance of the as-welded Cu12Mn8Al3Fe2Ni alloy is much more superior to that of the as-cast one. The cumulative mass loss and the mass loss rate of the as-welded Cu12Mn8Al3Fe2Ni alloy are almost 1/4 that of the as-cast one. SEM analysis of eroded specimens reveals that the as-cast Cu12Mn8Al3Fe2Ni alloy is attacked more severely than the as-welded one. Microcracks causing cavitation damage initiate at the phase boundaries.

  12. Structure and Properties of Sol-Gel Derived CuNiMnZrO2 Catalysts for CO Hydrogenation

    Institute of Scientific and Technical Information of China (English)

    Zhongyi Ma; Cheng Yang; Run Xu; Wei Wei; Wenhuai Li; Yuhan Sun

    2003-01-01

    Two CuNiMnZrO2 catalysts (crystallized or non-crystallized) were prepared by co-hydrolyzing zirconium n-propoxide with Cu(NO3)2, Mn(NO3)2 and Ni(NO3)2 in an ethanol solution in the presence of diglycol. The physical and chemical properties of the catalysts were characterized using BET, XRD,TEM, XPS and CO-DRIFT techniques. It was found that the non-crystallized CuNiMnZrO2 catalyst demonstrated highly dispersed active phases and high activity for CO adsorption, which resulted in good performance for synthesis of higher alcohols in CO hydrogenation compared to crystallized CuNiMnZrO2.

  13. Effect of Nickel Equivalent on Austenite Transition Ratio in Ni-Mn-Cu Cast Iron

    Directory of Open Access Journals (Sweden)

    Janus A.

    2013-06-01

    Full Text Available Determined was quantitative effect of nickel equivalent value on austenite decomposition degree during cooling-down castings of Ni-Mn- Cu cast iron. Chemical composition of the alloy was 1.8 to 5.0 % C, 1.3 to 3.0 % Si, 3.1 to 7.7 % Ni, 0.4 to 6.3 % Mn, 0.1 to 4.9 % Cu, 0.14 to 0.16 % P and 0.03 to 0.04 % S. Analysed were castings with representative wall thickness 10, 15 and 20 mm. Scope of the examination comprised chemical analysis (including WDS, microscopic observations (optical and scanning microscopy, image analyser, as well as Brinell hardness and HV microhardness measurements of structural components.

  14. Effect of Chemical Composition on Number of Eutectic Colonies in Ni-Mn-Cu Cast Iron

    Directory of Open Access Journals (Sweden)

    A. Janus

    2013-01-01

    Full Text Available Determined were direction and intensity of influence of alloying additions on the number of eutectic graphite colonies in austenitic cast iron Ni-Mn-Cu. Chemical composition of the cast iron was 1.7 to 3.3% C, 1.4 to 3.1% Si, 2.8 to 9.9% Ni, 0.4 to 7.7% Mn, 0 to 4.6% Cu,0.14 to 0.16% P and 0.03 to 0.04% S. Analysed were structures of mottled (20 castings and grey (20 castings cast iron. Obtained wereregression equations determining influence intensity of individual components on the number of graphite colonies per 1 cm2 (LK. It wasfound that, in spite of high total content of alloying elements in the examined cast iron, the element that mainly decides the LK value is carbon, like in a plain cast iron.

  15. Effect of Chemical Composition on Number of Eutectic Colonies in Ni-Mn-Cu Cast Iron

    Directory of Open Access Journals (Sweden)

    Janus A.

    2013-03-01

    Full Text Available Determined were direction and intensity of influence of alloying additions on the number of eutectic graphite colonies in austenitic cast iron Ni-Mn-Cu. Chemical composition of the cast iron was 1.7 to 3.3% C, 1.4 to 3.1% Si, 2.8 to 9.9% Ni, 0.4 to 7.7% Mn, 0 to 4.6% Cu, 0.14 to 0.16% P and 0.03 to 0.04% S. Analysed were structures of mottled (20 castings and grey (20 castings cast iron. Obtained were regression equations determining influence intensity of individual components on the number of graphite colonies per 1 cm2 (LK. It was found that, in spite of high total content of alloying elements in the examined cast iron, the element that mainly decides the LK value is carbon, like in a plain cast iron.

  16. Magnetic properties of Mn1.9Cu0.1Sb under high pressure

    Science.gov (United States)

    Matsumoto, Yoshihiro; Matsubayashi, Kazuyuki; Uwatoko, Yoshiya; Hiroi, Masahiko; Mitsui, Yoshifuru; Koyama, Keiichi

    2016-08-01

    Magnetization measurements were carried out for polycrystalline Mn1.9Cu0.1Sb in magnetic fields up to 5 T in the 10-300 K temperature range under high pressures up to 1 GPa in order to investigate the magnetic properties and the thermal transformation arrest (TTA) phenomenon under high pressures. The spin-reorientation temperature increased from 202 K for 0.1 MPa to 244 K for 1 GPa, whereas the transition temperature from the ferrimagnetic (FRI) to antiferromagnetic (AFM) state did not drastically change at ˜116 K. The magnetic relaxation behavior from the FRI to AFM state was observed in 10 < T ≤ 70 K, which was analyzed using the Kohlrausch-Williams-Watts model. Obtained results indicated that the TTA phenomenon of Mn1.9Cu0.1Sb was suppressed by the application of high pressures.

  17. Magnetic ordering of the Pr sublattice with the substitution of Cu for Mn in PrMn{sub 2}Si{sub 2} intermetallics

    Energy Technology Data Exchange (ETDEWEB)

    Elmali, A [Faculty of Engineering, Department of Engineering Physics, Ankara University, 06100 Besevler-Ankara (Turkey); Dincer, I [Faculty of Engineering, Department of Engineering Physics, Ankara University, 06100 Besevler-Ankara (Turkey); Elerman, Y [Faculty of Engineering, Department of Engineering Physics, Ankara University, 06100 Besevler-Ankara (Turkey); Ehrenberg, H [Institute for Materials Science, Darmstadt University of Technology, Petersenstrasse 23, D-64287 Darmstadt (Germany); Fuess, H [Institute for Materials Science, Darmstadt University of Technology, Petersenstrasse 23, D-64287 Darmstadt (Germany)

    2004-12-01

    The magnetic properties of PrMn{sub 2-x}Cu{sub x}Si{sub 2} (0 {<=} x {<=} 1) were studied by field-cooled and zero-field-cooled magnetization measurements in the temperature range 5 K {<=} T {<=} 350 K in low external fields (5 mT) and by magnetic-field-dependent magnetization measurements in fields up to 5.5 T. Substitution of Cu for Mn leads to a linear decrease in the lattice constant c and the unit cell volume V and a linear increase in the lattice constant a. Earlier neutron diffraction experiments showed that Pr does not order down to 1.6 K in PrMn{sub 2}Si{sub 2} while the ferromagnetic Mn planes are ordered antiparallel along the c axis. With the increasing Cu content, the magnetization increases rapidly at low temperatures for the samples with 0.4{<=} x {<=} 1. Cu substitution strongly changes the magnetic properties and leads to the magnetic ordering of the Pr sublattice. This is mainly deduced from the discussion of the values of the magnetic moments at low temperatures. Below the Curie temperatures T{sub C}, the spins in the Mn sublattice are arranged parallel to the Pr sublattice. With increasing Cu, T{sub C}(x) has a maximum value of 155 K at x = 0.6 and decreases for samples with x {>=} 0.7.

  18. Characteristics of flake graphite in Ni-Mn-Cu cast iron. Part 2

    National Research Council Canada - National Science Library

    A. Janus

    2010-01-01

    .... In this second part of the research, effect of chemical composition of hypereutectic cast iron containing 3.5÷5.1% C, 1.7÷2.8% Si, 3.5÷10.5 %Ni, 2.0÷8.0% Mn, 0.1÷3.5% Cu, 0.14÷0.17% P and 0.02÷0.04...

  19. Effect of tellurium on machinability and mechanical property of CuAlMnZn shape memory alloy

    Energy Technology Data Exchange (ETDEWEB)

    Liu Na [School of Materials Science and Engineering, Central South University, Changsha, 410083 (China); Li Zhou, E-mail: lizhou6931@csu.edu.cn [School of Materials Science and Engineering, Central South University, Changsha, 410083 (China); Key Laboratory of Nonferrous Metal Materials Science and Engineering, Ministry of Education, Changsha, 410083 (China); Xu Genying; Feng Ze; Gong Shu; Zhu Lilong; Liang Shuquan [School of Materials Science and Engineering, Central South University, Changsha, 410083 (China)

    2011-10-15

    Highlights: {yields} A novel free-machining Cu-7.5Al-9.7Mn-3.4Zn-0.3Te (wt.%) shape memory alloy has been developed. {yields} The size of dispersed particles with richer Te is 2-5 {mu}m. {yields} The CuAlMnZnTe alloy has good machinability which approached that of BZn15-24-1.5 due to the addition of Te. {yields} Its shape memory property keeps the same as that of CuAlMnZn alloy with free Te. {yields} The CuAlMnZn shape memory alloy with and without Te both have good ductile as annealed at 700 deg. C for 15 min. - Abstract: The microstructure transition, shape memory effect, machinability and mechanical property of the CuAlMnZn alloy with and without Te have been studied using X-ray diffraction analysis, chips observation and scanning electron microscopy (SEM), tensile strength test and differential scanning calorimeter (DSC), and semi-quantitative shape memory effect (SME) test. The particles with richer Te dispersedly distributed in grain interior and boundary with size of 2-5 {mu}m. After the addition of Te, the CuAlMnZnTe alloy machinability has been effectively increased to approach that of BZn15-24-1.5 and its shape memory property remains the same as the one of CuAlMnZn alloy. The CuAlMnZn shape memory alloys with and without Te both have good ductility as annealed at 700 deg. C for 15 min.

  20. Regenerable Cu-intercalated MnO2 layered cathode for highly cyclable energy dense batteries

    Science.gov (United States)

    Yadav, Gautam G.; Gallaway, Joshua W.; Turney, Damon E.; Nyce, Michael; Huang, Jinchao; Wei, Xia; Banerjee, Sanjoy

    2017-03-01

    Manganese dioxide cathodes are inexpensive and have high theoretical capacity (based on two electrons) of 617 mAh g-1, making them attractive for low-cost, energy-dense batteries. They are used in non-rechargeable batteries with anodes like zinc. Only ~10% of the theoretical capacity is currently accessible in rechargeable alkaline systems. Attempts to access the full capacity using additives have been unsuccessful. We report a class of Bi-birnessite (a layered manganese oxide polymorph mixed with bismuth oxide (Bi2O3)) cathodes intercalated with Cu2+ that deliver near-full two-electron capacity reversibly for >6,000 cycles. The key to rechargeability lies in exploiting the redox potentials of Cu to reversibly intercalate into the Bi-birnessite-layered structure during its dissolution and precipitation process for stabilizing and enhancing its charge transfer characteristics. This process holds promise for other applications like catalysis and intercalation of metal ions into layered structures. A large prismatic rechargeable Zn-birnessite cell delivering ~140 Wh l-1 is shown.

  1. Dynamic mechanical analyze of superelastic CuMnAl shape memory alloy

    Science.gov (United States)

    (Dragoș Ursanu, A. I.; Stanciu, S.; Pricop, B.; Săndulache, F.; Cimpoeșu, N.

    2016-08-01

    A new shape memory alloy was obtain from high purity Cu, Mn and Al elements using a induce furnace. The intelligent material present negative transformation temperatures and an austenite like state at room temperature. The austenite state of CuMnAl shape memory alloy present superelasticity property. Five kilograms ingot was obtain of Cu10Mn10Al alloy. From the base material (melted state) were cut samples with 6 mm thickness using a mechanical saw. After an homogenization heat treatment the samples were hot rolled through four passes with a reduction coefficient of 20%. Experimental lamellas were obtained with 1.5 mm thickness and 90x10 mm length and width. After the hot rolled treatment the materials were heat treated at 800°C for 20 minutes and chilled in water. Four samples, one just laminated and three heat treated by aging, were analyzed with a Netzsch DMA equipment to establish the elastic modulus and the internal friction values of the materials. Metallic materials microstructure was analyzed using a scanning electron microscope Vega Tescan LMH II type. After the aging heat treatment a decrease of internal friction is observed on the entire analyze range which is assigned to formation of Al-based precipitates that block the internal movement of the alloy characteristic phases.

  2. Effect of alloying elements on solidification of primary austenite in Ni-Mn-Cu cast iron

    Directory of Open Access Journals (Sweden)

    A. Janus

    2011-04-01

    Full Text Available Within the research, determined were direction and intensity of alloying elements influence on solidification way (directional orvolumetric of primary austenite dendrites in hypoeutectic austenitic cast iron Ni-Mn-Cu. 50 cast shafts dia. 20 mm were analysed.Chemical composition of the alloy was as follows: 1.7 to 3.3 % C, 1.4 to 3.1 % Si, 2.8 to 9.9 % Ni, 0.4 to 7.7 % Mn, 0 to 4.6 % Cu, 0.14 to0.16 % P and 0.03 to 0.04 % S. The discriminant analysis revealed that carbon influences solidification of primary austenite dendrites most intensively. It clearly increases the tendency to volumetric solidification. Influence of the other elements is much weaker. This means that the solidification way of primary austenite dendrites in hypoeutectic austenitic cast iron Ni-Mn-Cu does not differ from that in an unalloyed cast iron.

  3. Hyperfine structure constants for singly ionized manganese (Mn II) using Fourier transform spectroscopy

    Science.gov (United States)

    Townley-Smith, Keeley; Nave, Gillian; Pickering, Juliet C.; Blackwell-Whitehead, Richard J.

    2016-09-01

    We expand on the comprehensive study of hyperfine structure (HFS) in Mn II conducted by Holt et al. (1999) by verifying hyperfine magnetic dipole constants (A) for 20 levels previously measured by Holt et al. (1999) and deriving A constants for 47 previously unstudied levels. The HFS patterns were measured in archival spectra from Fourier transform (FT) spectrometers at Imperial College London and the National Institute of Standards and Technology. Analysis of the FT spectra was carried out in XGREMLIN. Our A constant for the ground level has a lower uncertainty by a factor of 6 than that of Blackwell-Whitehead et al.

  4. 21 CFR 184.1449 - Manganese citrate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Manganese citrate. 184.1449 Section 184.1449 Food... Specific Substances Affirmed as GRAS § 184.1449 Manganese citrate. (a) Manganese citrate (Mn3(C6H5O7)2, CAS... manganese carbonate from manganese sulfate and sodium carbonate solutions. The filtered and...

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

    Science.gov (United States)

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

    2017-03-01

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

  6. Formation of manganese phosphate and manganese carbonate during long-term sorption of Mn2+ by viable Shewanella putrefaciens: effects of contact time and temperature

    NARCIS (Netherlands)

    Chubar, N.; Avramut, C.; Visser, T.

    The influence of temperature (5, 10, 22 and 30 C) on the long-term (30 days) sorption of Mn2+ by viable Shewanella putrefaciens was studied by FTIR and EXAFS. The additional Mn-removal capacity of these bacteria was found to result from the surface precipitation of Mn-containing inorganic phases.

  7. Speciation of organic carbon, Cu and Mn in the River Marne (France): the role of colloids

    Science.gov (United States)

    Jaïry, A.; Garban, B.; Blanchard, M.; Chesterikoff, A.

    1999-02-01

    The distribution of organic carbon (OC) and of some metals (Cu, Mn) amongst the particulate (>0·2 m), colloidal (10 kDa-0·2 m) and the truly dissolved (ultrafiltration (UF) device was utilized to separate the colloidal fraction. On average, 22% of the OC, 31% of the Cu and 53% of the Mn, usually assigned to the so-called dissolved fraction, were found in the colloidal fraction. The colloidal fraction exhibited a behaviour different from that of the particulate and truly dissolved fractions. Autochthonous production led to enrichment in the colloidal and particulate OC pools: up to 47% of the total dissolved OC was in the colloidal fraction. An increase in the colloidal metal fraction, concomitant with a fall in the truly dissolved fraction, coincided with peaks in phytoplankton during the bloom. These phenomena might be related either to an increase in pH associated with photosynthetic activity, resulting in the precipitation of truly dissolved forms into the colloidal fraction, or to scavenging of the truly dissolved metals by the algal species of colloidal size.The interaction between the colloidal and the truly dissolved phases was very important. The partition coefficients of the Cu and Mn between the colloidal and truly dissolved fractions were higher than between the particulate and the truly dissolved fractions. This pattern is consistent with a greater specific surface area of colloids than macroparticles. Consequently, the adsorption and complexation capacities are enhanced in the colloidal fraction of the particulate matter.The extraction of hydrophobic complexes with Cu using C18 Sep-Pak columns, showed that the Cu occurring in colloidal, total dissolved or truly dissolved forms was significantly complexed by the organic matter. The truly dissolved fraction might be complexed up to 100% during a phytoplankton bloom.

  8. Monitoring the role of Mn and Fe in the As-removal efficiency of tetravalent manganese feroxyhyte nanoparticles from drinking water: An X-ray absorption spectroscopy study.

    Science.gov (United States)

    Pinakidou, F; Katsikini, M; Paloura, E C; Simeonidis, K; Mitraka, E; Mitrakas, M

    2016-09-01

    The implementation of amorphous tetravalent manganese feroxyhyte (TMFx) nanoparticles, prepared via co-precipitation synthesis, as an efficient As(V)-removal material is investigated using X-ray absorption fine structure (XAFS) spectroscopy at the Fe-, Mn- and As-K-edges. The optimum synthesis conditions and chemical composition of the TMFx adsorbent were determined by the degree of polymerization in the adsorbents' microstructure. Under synthesis into mildly acidic conditions, the change in the polymerization of the metal-oxyhydroxyl chains (metal=Fe, Mn) provides more adsorption sites at edges and corner sites in the bonding environment of Fe and Mn, respectively, thereby enhancing As uptake. After exposure to As-polluted water, similar microstructural changes related to As-bidentate and monodentate geometries are generated: As(V) preferentially occupies the high energy adsorption sites ((2)C complexes) available in the Mn-oxyhydroxyl groups and the low energy edge sites offered by Fe ((2)E complexes). It is revealed that optimum arsenic-removal by TMFx occurs into mildly acidic synthesis pH and for iron to manganese molar ratio equal to 3. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Lithium/Manganese Dioxide (Li/MnO(2)) Battery Performance Evaluation: Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Ingersoll, D.; Clark, N.H.

    1999-04-01

    In February 1997, under the auspices of the Product Realization Program, an initiative to develop performance models for lithium/manganese dioxide-based batteries began. As a part of this initiative, the performance characteristics of the cells under a variety of conditions were determined, both for model development and for model validation. As a direct result of this work, it became apparent that possible Defense Program (DP) uses for batteries based on this cell chemistry existed. A larger effort aimed at mapping the performance envelope of this chemistry was initiated in order to assess the practicality of this cell chemistry, not only for DP applications, but also for other uses. The work performed included an evaluation of the cell performance as a function of a number of variables, including cell size, manufacturer, current, pulse loads, constant current loads, safety, etc. In addition, the development of new evaluation techniques that would apply to any battery system, such as those related to reliability assessments began. This report describes the results of these evaluations.

  10. Malonate-containing manganese(III) complexes: synthesis, crystal structure, and magnetic properties of AsPh4[Mn(mal)2(H2O)2].

    Science.gov (United States)

    Delgado, Fernando S; Kerbellec, Nicolas; Ruiz-Pérez, Catalina; Cano, Joan; Lloret, Francesc; Julve, Miguel

    2006-02-06

    The novel manganese(III) complexes PPh4[Mn(mal)2(H2O)2] (1) and AsPh4[Mn(mal)2(H2O)2] (2) (PPh4+ = tetraphenylphosphonium cation, AsPh4+ = tetraphenylarsonium cation, and H2mal = malonic acid) have been prepared, and the structure of 2 was determined by X-ray diffraction analysis. 2 is a mononuclear complex whose structure is made up of trans-diaquabis(malonato)manganate(III) units and tetraphenylarsonium cations. Two crystallographically independent manganese(III) ions (Mn(1) and Mn(2)) occur in 2 that exhibit elongated octahedral surroundings with four oxygen atoms from two bidentate malonate groups in equatorial positions (Mn(1)-O = 1.923(6) and 1.9328(6) A and Mn(2)-O = 1.894(6) and 1.925(6) A) and two trans-coordinated water molecules in the axial sites (Mn(1)-Ow = 2.245(6) A and Mn(2)-Ow = 2.268(6) A). The [Mn(mal)2(H2O)2]- units are linked through hydrogen bonds involving the free malonate-oxygen atoms and the coordinated water molecules to yield a quasi-square-type anionic layer growing in the ab plane. The shortest intralayer metal-metal separations are 7.1557(7) and 7.1526(7) A (through the edges of the square). The anionic sheets are separated from each other by layers of AsPh4+ where sextuple- and double-phenyl embraces occur. The magnetic behavior of 1 and 2 in the temperature range 1.9-290 K reveals the occurrence of weak intralayer ferromagnetic interactions (J = +0.081(1) (1) and +0.072(2) cm(-1) (2)). These values are compared to those of the weak antiferromagnetic coupling [J = -0.19(1) cm(-1)], which is observed in the chain compound K2[Mn(mal)2(MeOH)2][Mn(mal)2] (3), where the exchange pathway involves the carboxyate-malonate bridge in the anti-syn conformation. The structure of 3 was reported elsewhere. Theoretical calculations on fragment models of 2 and 3 were performed to analyze and substantiate both the nature and magnitude of the magnetic couplings observed.

  11. Gene Expression and Activities of SOD in Cucumber Seedlings Were Related with Concentrations of Mn2+,Cu2+,or Zn2+ Under Low Temperature Stress

    Institute of Scientific and Technical Information of China (English)

    GAO Jun-jie; LI Tao; YU Xian-chang

    2009-01-01

    Effects of increasing Mn2+,Cu2+,or Zn2+ on SOD expressions were studied in cucumber seedlings under low temperature stress.Both gene expressions and activities of Cu/Zn-SOD and Mn-SOD in cucumber seedling leaves were induced by increasing Mn2+,Cu2+,or Zn2+ under low temperature stress,especially 48 h afterwards.The activities of Cu/Zn-SOD and Mn-SOD at 0 and 48 h after treatment were in accordance with their gene expression levels,which implied that the transcriptional regulation plays key roles in regulating their activities at the early stage of low temperature stress.Gene expressions of Cu/Zn-SOD and Mn-SOD declined at 96 h,but Cu/Zn-SOD and Mn-SOD activities still remain high,which suggested that Cu/Zn-SOD and Mn-SOD activities might be regulated by other factors after transcription at the later stage of low temperature stress.Therefore,we concluded that the increasing Mn2+,Cu2+,or Zn2+ could increase the capacity of scavenging ROS in cucumber seedlings under low temperature stress by inducing gene expressions of Cu/Zn-SOD and Mn-SOD,elevating activities of Cu/Zn-SOD,Mn-SOD,or regulating other factors after transcription.

  12. ac MH loop measurements on Mn doped YBa2Cu3O7– superconductors

    Indian Academy of Sciences (India)

    E Isaac Samuel; V Seshu Bai

    2006-06-01

    Isothermal ac MH (magnetization-field) loops for varying field amplitudes were recorded at 77 K on YBa2(Cu1–Mn)3O7– with = 0, 0.010, 0.015, 0.020, 0.025, 0.035 and 0.050, YBa2(Cu0.075Fe0.025)3O7–, YBa2(Cu0.075Ni0.025)3O7– and YBa2(Cu0.075Zn0.025)3O7– samples up to a maximum field amplitude of 80 Oe. Flat band susceptibility, ac losses and flux profiles were deduced from the ac MH loops. The undoped sample exhibited a minimum weak link ac loss and the 5.0% doped sample showed maximum weak link ac loss. Ni and Fe doped samples showed higher granular losses. cg estimated from the flux profiles decreases monotonically with increasing concentrations of Mn up to 2.5%.

  13. Excitation dependent multicolor emission and photoconductivity of Mn, Cu doped In2S3 monodisperse quantum dots

    Science.gov (United States)

    Ghosh, Sirshendu; Saha, Manas; Ashok, Vishal Dev; Chatterjee, Arijit; De, S. K.

    2016-04-01

    Indium sulphide (In2S3) quantum dots (QDs) of average size 6 ± 2 nm and hexagonal nanoplatelets of average size 37 ± 4 nm have been synthesized from indium myristate and indium diethyl dithiocarbamate precursors respectively. The absorbance and emission band was tuned with variation of nanocrytal size from very small in the strong confinement regime to very large in the weak confinement regime. The blue emission and its shifting with size has been explained with the donor-acceptor recombination process. The 3d element doping (Mn2+ and Cu2+) is found to be effective for formation of new emission bands at higher wavelengths. The characteristic peaks of Mn2+ and Cu2+ and the modification of In3+ peaks in the x-ray photoelectric spectrum (XPS) confirm the incorporation of Mn2+ and Cu2+ into the In2S3 matrix. The simulation of the electron paramagnetic resonance signal indicates the coexistence of isotropic and axial symmetry for In and S vacancies. Moreover, the majority of Mn2+ ions and sulphur vacancies (VS ) reside on the surface of nanocrystals. The quantum confinement effect leads to an enhancement of band gap up to 3.65 eV in QDs. The formation of Mn 3d levels between conduction band edge and shallow donor states is evidenced from a systematic variation of emission spectra with the excitation wavelength. In2S3 QDs have been established as efficient sensitizers to Mn and Cu emission centers. Fast and slow components of photoluminescence (PL) decay dynamics in Mn and Cu doped QDs are interpreted in terms of surface and bulk recombination processes. Fast and stable photodetctors with high photocurrent gain are fabricated with Mn and Cu doped QDs and are found to be faster than pure In2S3. The fastest response time in Cu doped QDs is an indication of the most suitable system for photodetector devices.

  14. Exchange bias through a Cu interlayer in an IrMn/Co system

    Science.gov (United States)

    Geshev, J.; Nicolodi, S.; Pereira, L. G.; Nagamine, L. C. C. M.; Schmidt, J. E.; Deranlot, C.; Petroff, F.; Rodríguez-Suárez, R. L.; Azevedo, A.

    2007-06-01

    Ferromagnetic resonance (FMR) and magnetization (MAG) measurements were used to study the exchange interaction between the antiferromagnetic and ferromagnetic layers in an IrMn/Cu/Co system as a function of the Cu spacer thickness. Although the experimental angular variations of the exchange-bias fields HebFMR and HebMAG coincide, the coupling strengths J and the Co layers’ anisotropy fields HU , obtained via numerical simulations, are different. For all Cu thicknesses JFMR>JMAG and HUFMR

  15. Research on Shock Absorbing Properties of Mn-Cu Damping Alloy%Mn-Cu阻尼合金减振性能的研究

    Institute of Scientific and Technical Information of China (English)

    陈泠俐; 李宁; 文玉华; 林波

    2011-01-01

    The damping properties of Mn-Cu damping alloy and its component's shock absorbing properties were studied by reversal torsion pendulum and vibration test equipments. The results indicate that Mn-Cu damping alloys all display high damping capacity compared with 18-8 stainless steel; the damping effect of Mn-Cu alloy increases quickly with the strain amplitude increasing and a terrace appears near the amplitude of 2× 10-4; compared with 18-8 stainless steel, Mn-Cu alloy barrel-shape component show good shock absorbing properties under free vibration and forced vibration.%利用倒扭摆和振动测试装置,研究了Mn-Cu阻尼合金的阻尼性能与其构件的减振性能.结果表明:Mn-Cu阻尼合金具有良好的力学性能,同18-8不锈钢相比,该合金具有显著的高阻尼性能;Mn-Cu合金的阻尼效果随应变振幅的增加而迅速增加,在应变振幅2×10-4左右出现平台;在自由振动条件下和受迫振动条件下,与18-8不锈圆桶相比,Mn-Cu合金圆桶构件表现出优良的减振性能.

  16. Manganese (Mn) stress toward hyperaccumulators plants combination (HPC) using Jatropha curcas and lamtoro gung (L. leucocephala) in mychorrizal addition on soybean (Glycine max) seedling stage

    Science.gov (United States)

    Darmawan, Tania Sylviana; Zahroh, Tata Taqiyyatuz; Merindasya, Mirza; Masfaridah, Ririn; Hartanti, Dyah Ayu Sri; Arum, Sekar; Nurhatika, Sri; Muhibuddin, Anton; Surtiningsih, Tini; Arifiyanto, Achmad

    2017-06-01

    Heavy metals were a metal bracket which had a specific gravity greater than 5 g / cm3. Manganese was one of them because it has a specific gravity of 7.4 g / cm3. Together with widespread cases of soil contamination caused by heavy metals as well as increased development of the science of breeding ground rapidly, then the alternative rehabilitation techniques were relatively cheap and effective it needs to be developed and even some cases of contaminated management soil using a combination of plants with microorganisms to be more effective. Thus it was necessary to develop research on plants that were able to accumulate heavy metals and other toxic materials, such as Mn so that the land becomes safe for health and the environment. Based on above reason this research aimed to see the influence of hyperaccumulators combination of plants using Jatropha curcas and lamtoro gung (L. leucocephala) in mychorrizal addition to stressed by manganese (Mn) on soybean (Glycine max). Observations of growth, chlorophyll content and heavy metals analysis performed on nine treatments (P1-P9) and one control (P0). The results showed a combination of hyperaccumulators under mychorrizal helped overcome the stress of manganese (Mn) in the leaves of soybean (G. max). It gave an influence on the number of leaves and chlorophyll content of soybean (G. max), but no effect performed on the height and the roots of soybean (G. max). The use of plants in small amounts hyperaccumulators (P1;1 jatropha and 1 lamtoro) was sufficient to cope with stress of Mn in the leaves of soybean (G. max).

  17. Double-exchange driven ferromagnetic metal-paramagnetic insulator transition in Mn-doped CuO

    Science.gov (United States)

    Filippetti, Alessio; Fiorentini, Vincenzo

    2006-12-01

    Employing ab initio self-interaction-corrected local-spin-density calculations, we explain the nature of the ferromagnetic, metallic phase of Mn-doped CuO (an antiferromagnetic insulator when undoped), and of its concurrent transitions to a paramagnetic, insulating phase. Mn-induced donor levels enable conduction through ferromagnetically aligned Mn centers and ferromagnetic CuO planes via double exchange. In the paramagnetic insulating phase, a polaron hopping mechanism consistent with the experiments is envisaged. Our results suggest the intriguing possibility of designing double-exchange driven ferromagnetic cuprates.

  18. Magnetic ordering of the Pr sublattice with the substitution of Cu for Mn in PrMn2Si2 intermetallics

    Science.gov (United States)

    Elmali, A.; Dincer, I.; Elerman, Y.; Ehrenberg, H.; Fuess, H.

    2004-12-01

    The magnetic properties of PrMn2-xCuxSi2 (0 \\le x \\le 1 ) were studied by field-cooled and zero-field-cooled magnetization measurements in the temperature range 5 K \\le T \\le 350 K in low external fields (5 mT) and by magnetic-field-dependent magnetization measurements in fields up to 5.5 T. Substitution of Cu for Mn leads to a linear decrease in the lattice constant c and the unit cell volume V and a linear increase in the lattice constant a. Earlier neutron diffraction experiments showed that Pr does not order down to 1.6 K in PrMn2Si2 while the ferromagnetic Mn planes are ordered antiparallel along the c axis. With the increasing Cu content, the magnetization increases rapidly at low temperatures for the samples with 0.4 \\le x \\le 1 . Cu substitution strongly changes the magnetic properties and leads to the magnetic ordering of the Pr sublattice. This is mainly deduced from the discussion of the values of the magnetic moments at low temperatures. Below the Curie temperatures TC, the spins in the Mn sublattice are arranged parallel to the Pr sublattice. With increasing Cu, TC(x) has a maximum value of 155 K at x = 0.6 and decreases for samples with x \\ge 0.7 .

  19. CuMnOS Nanoflowers with Different Cu+/Cu2+ Ratios for the CO2-to-CH3OH and the CH3OH-to-H2 Redox Reactions

    Science.gov (United States)

    Chen, Xiaoyun; Abdullah, Hairus; Kuo, Dong-Hau

    2017-01-01

    A conservative CO2-Methanol (CH3OH) regeneration cycle, to capture and reutilize the greenhouse gas of CO2 by aqueous hydrogenation for industry-useful CH3OH and to convert aqueous CH3OH solution by dehydrogenation for the clean energy of hydrogen (H2), is demonstrated at normal temperature and pressure (NTP) with two kinds of CuMnOS nanoflower catalysts. The [Cu+]-high CuMnOS led to a CH3OH yield of 21.1 mmol·g−1catal.·h−1 in the CuMnOS-CO2-H2O system and the other [Cu+]-low one had a H2 yield of 7.65 mmol·g−1catal.·h−1 in the CuMnOS-CH3OH-H2O system. The successful redox reactions at NTP rely on active lattice oxygen of CuMnOS catalysts and its charge (hole or electron) transfer ability between Cu+ and Cu2+. The CO2-hydrogenated CH3OH in aqueous solution is not only a fuel but also an ideal liquid hydrogen storage system for transportation application. PMID:28117456

  20. 1,1,1-Tris(hydroxymethyl)propane in manganese carboxylate chemistry: synthesis, structure and magnetic properties of a mixed-valence [MnIII4MnII4] cluster featuring the novel [MnIII4MnII4(mu3-OR)6(mu2-OR)8]6+ core.

    Science.gov (United States)

    Milios, Constantinos J; Fabbiani, Francesca P A; Parsons, Simon; Murugesu, Muralee; Christou, George; Brechin, Euan K

    2006-01-14

    The reaction between MnBr(2).4H(2)O with H(3)tmp (1,1,1-tris(hydroxymethyl)propane) in MeCN in the presence of Na(O(2)CCMe(3)) and NBu(4)Br produces the complex [Mn(8)(O(2)CCMe(3))(2)(tmp)(2)(Htmp)(4)Br(4)(H(2)O)(2)].2MeCN (1.2MeCN) in good yield. The centrosymmetric octanuclear molecule consists of four Mn(III) and four Mn(II) ions assembled together by fourteen alkoxo bridges to give a [Mn(III)(4)Mn(II)(4)(mu(3)-OR)(6)(mu(2)-OR)(8)](6+) rod-like core in which the metal centres are arranged in a planar zigzag fashion. Peripheral ligation is provided by a combination of bridging pivalate ions, terminal bromides and water molecules. Dc magnetic susceptibility measurements reveal the presence of dominant antiferromagnetic interactions leading to a spin ground state of S = 0. A rationalization of this result is attempted by structural comparison with previously reported tetranuclear manganese complexes containing the [Mn(III)(2)Mn(II)(2)(mu(3)-OR)(2)(mu(2)-OR)(4)] core in which the magnetic interactions are ferromagnetic.

  1. Validation of chemical-looping with oxygen uncoupling (CLOU using Cu-based oxygen carrier and comparative study of Cu, Mn and Co based oxygen carriers using ASPEN plus

    Directory of Open Access Journals (Sweden)

    Xiao Zhang, Subhodeep Banerjee, Ramesh K. Agarwal

    2015-01-01

    Full Text Available The chemical-looping with oxygen uncoupling (CLOU has been demonstrated to be an effective technological pathway for high-efficiency low-cost carbon dioxide capture when particulate coal serves as the fuel. In this paper, complete process-level modeling of CLOU process conducted in ASPEN Plus is presented. The heat content of fuel and air reactors and air/flue gas heat exchangers is carefully examined. It is shown that the established model provides results which are in excellent agreement with the experiments for the overall power output of the CLOU process. Finally the effect of varying the air flow rate and three different types of coal as the solid fuel on energy output is investigated, and the performance of three – Copper (Cu, Manganese (Mn and Cobalt (Co based oxygen carriers in CLOU process is compared. It is shown that there exists an optimal air flow rate to obtain the maximum power output for a given coal feeding rate and coal type. The effect of three different oxygen carriers on energy output is also investigated using the optimal air flow rate. Among the three oxygen carriers - CuO, Mn2O3, and Co3O4; Mn2O3 shows the best performance on power output. The results presented in this paper can be used to estimate the amount of various quantities such as the air flow rate and oxygen carrier (and its type required to achieve near optimal energy output from a CLOU process based power plant.

  2. Effects of Doping Mn on Nd1.85Ce0.15CuO4 System

    Institute of Scientific and Technical Information of China (English)

    Fa-She Wang; Yong-Liang Chen; Ye Yang; Yong Zhang; Cui-Hua Cheng; Yong Zhao

    2008-01-01

    Nd1.85Ce0.15Cu1-xMnxO4 samples with doping level up to 20% have been synthesized by solid-state reaction method. The influence of Mn on their normal-state transport, crystal structure, superconductivity and magnetic properties has been investigated. For the samples with x>0.03, magnetization under zero-field cooling indicates that the magnetic state changes from ferromagnetic to paramagnetic at T≈100 K, which can be explained with the interaction between Mn4+and Mn3+. The electrical resistivity ρ of samples increases with Mn doping. For the samples with doping level lower than 0.20, ρ initially increases with the decrease of temperature, i.e., dρ/dt<0, and then shows superconductivity transition at T≈20 K. The results suggest the coexistence of superconductivity and ferromagnetic ordering in Mn doped Nd1.85Ce0.15CuO4.

  3. Preparation of manganese salts of carboxylic acids labelled with ''54Mn and comparison with ''54 MnCl{sub 2} in liquid scintillation counting; Preparacion de sales manganosas de acidos alifaticos monocarboxilicos marcados con ''54 MnCl{sub 2} en medidas por centelleo liquido

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Barquero, L.; Arcos Merino, J. M. los; Grau Malonda, A.

    1992-07-01

    Procedures for liquid scintillation sample preparation of manganese dimethylbutirate, decanoate and palmitate, labelled with 54 Mn are described. their quenching effect, spectral evolution and counting stability along several weeks are analysed in liquid scintillation measurements with Toluene. HISafe II. PCS, instagel. Dioxane-naphtalene and Toluene-alcohol. For comparison, Inorganic 54 MnCl-2 samples are also studied, resulting in acceptable counting stability but showing greater quenching and signs of little spectral degradation against the organic samples. (Author)

  4. Reinforcement of bulk Y-Ba-Cu-O superconductors by using Fe-Mn-Si-Ni shape memory alloy rings

    Science.gov (United States)

    Seki, H.; Honma, Y.; Nomura, M.; Nakayama, C.; Koshizuka, N.; Maruyama, T.; Murakami, M.

    Bulk Y-Ba-Cu-O superconductors are brittle ceramics and their tensional strengths are very low. Therefore, reinforcement of the bulk superconductor is needed for practical applications. Pre-compression load has been shown to be effective in enforcing the bulk superconductors. Fe-Mn-Si alloys exhibit shape-memory effects and the size change due to the shape recovery is large. Therefore, the Fe-Mn-Si shape memory alloy rings will function as effective reinforcement material for the bulk superconductors. We prepared Y-Ba-Cu-O bulk superconductors with top-seeded melt-growth process and the Ni added Fe-Mn-Si (Fe-Mn-Si-Ni) alloy ring which exhibited better shape memory performances than Ni-free Fe-Mn-Si alloys. The ring was extended by inserting a steel rod and heated to 623K. The amount of shape recovery strain was about 2%. Based on these results, the TSMG-processed bulk YBa- Cu-O superconductor 39.0 mm in diameter was inserted into the Fe-Mn-Si-Ni ring whose inner diameter was 39.3 mm at room temperature. With heating to 623K, the Fe-Mn-Si-Ni ring shrank and firmly encapsulated the bulk Y-Ba-Cu-O superconductor. Cracking was not observed in the bulk superconductor. It was interesting to note that the trapped magnetic field of the Y-Ba-Cu-O superconductor at 77K was increased from 2,550 G to 3,795 G through Fe-Mn-Si-Ni ring reinforcement. These results clearly show that the reinforcement treatment with Fe-Mn-Si-Ni alloy ring or pre-compression load is effective in improving the field trapping ability in addition to thee improvement of the mechanical properties.

  5. Measurement of the time-resolved spectrum of photoelectrons from ZnS:Mn, Cu luminescent material

    CERN Document Server

    Dong Guo Yi; Wei Zh; Yang Shao Peng; Fu Guang Sheng

    2003-01-01

    The process of decay of photoelectrons in the conduction band of ZnS:Mn, Cu luminescent materials after excitation with a short-pulse laser has been investigated in this paper by means of measurements made using the microwave absorption dielectric spectrum detection technique. Exponential decay processes were observed for the electrons in the conduction band and the shallow-trapped electrons; the lifetimes of the electrons were found to be 1177 and 1703 ns, respectively. The processes of decay of the luminescence from ZnS:Mn, Cu were investigated and exponential decay processes were found for blue Cu sup + , green Cu sup + and Mn sup 2 sup + luminescent centres with lifetimes of the excited state of 139, 140 and 680 mu s, respectively.

  6. Manganese Oxidation State Assignment for Manganese Catalase.

    Science.gov (United States)

    Beal, Nathan J; O'Malley, Patrick J

    2016-04-06

    The oxidation state assignment of the manganese ions present in the superoxidized manganese (III/IV) catalase active site is determined by comparing experimental and broken symmetry density functional theory calculated (14)N, (17)O, and (1)H hyperfine couplings. Experimental results have been interpreted to indicate that the substrate water is coordinated to the Mn(III) ion. However, by calculating hyperfine couplings for both scenarios we show that water is coordinated to the Mn(IV) ion and that the assigned oxidation states of the two manganese ions present in the site are the opposite of that previously proposed based on experimental measurements alone.

  7. Ability of Mn2+ to Permeate the Eye and Availability of Manganese-enhanced Magnetic Resonance Imaging for Visual Pathway Imaging via Topical Administration

    Institute of Scientific and Technical Information of China (English)

    Yao Chen; Chun-Yan Shi; Ying Li; Yun-Tao Hu; Hong-Bin Han; Xiao-Dong Sun; Satyajeet S Salvi

    2016-01-01

    Background:Manganese-enhanced magnetic resonance imaging (MEMRI) for visual pathway imaging via topical administration requires further research.This study investigated the permeability of the corneal epithelium and corneal toxicity after topical administration of Mn2+ to understand the applicability of MEMRI.Methods:Forty New Zealand rabbits were divided into 0.05 mol/L,0.10 mol/L,and 0.20 mol/L groups as well as a control group (n =10 in each group).Each group was further subdivided into epithelium-removed and epithelium-intact subgroups (n =5 in each subgroup).Rabbits were given 8 drops of MnC12 in 5 min intervals.The Mn2+ concentrations in the aqueous and vitreous humors were analyzed using inductively coupled plasma-mass spectrometry at different time points.MEMRI scanning was carried out to image the visual pathway after 24 h.The corneal toxicity of Mn2+ was evaluated with corneal imaging and pathology slices.Results:Between the aqueous and vitreous humors,there was a 10 h lag for the peak Mn2+ concentration times.The intraocular Mn2+ concentration increased with the concentration gradients of Mn2+ and was higher in the epithelium-removed subgroup than that in the epithelium-intact subgroup.The enhancement of the visual pathway was achieved in the 0.10 mol/L and 0.20 mol/L epithelium-removed subgroups.The corresponding peak concentrations of Mn2+ were 5087 ± 666 ng/ml,22920 ± 1188 ng/ml in the aqueous humor and 884 ± 78 ng/ml,2556 ± 492 ng/ml in the vitreous body,respectively.Corneal injury was evident in the epithelium-removed and 0.20 mol/L epithelium-intact subgroups.Conclusions:The corneal epithelium is a barrier to Mn2+,and the iris and lens septum might be another intraocular barrier to the permeation of Mn2+.An elevated Mn2+ concentration contributes to the increased permeation of Mn2+,higher MEMRI signal,and corneal toxicity.The enhancement of the visual pathway requires an effective Mn2+ concentration in the vitreous body.

  8. Crystal structure and thermal stability of martensite in Cu-25Al-3Mn alloy

    Institute of Scientific and Technical Information of China (English)

    李周; 汪明朴; 曹玲飞; 徐根应; 苏玉长

    2002-01-01

    The martensite structure in Cu-25Al-3Mn alloy and its thermal cycling and aging behavior are studied. It is convinced that the M2H martensite can be obtained by water-quenched, and the atoms distribution on the basal plane of the mart ensite is: Ⅰ(corner)-Al; Ⅱ(center of the plane)-Cu; Ⅲ(middle of b- side)-22/25Cu+3/25Mn. The lattice parameters are determined to be a=0.445 9 nm, b=0.527 9 nm, c=0.424 1 nm, β=88.64°. The triangle and other complicated configurations consisting of the variant group in the martensite are discovered. It is showed that the tested alloy has a high thermal stability when aging at average temperature in the parent phase, and the thermoelastic martensite amount is up to 90% af ter aging for 96 hat 400 ℃. The thermal cycling has a little influence on the transform ation temperature (Ms). When the number of thermal cycles is up to 1000, the increasing of Ms is only 8 ℃.

  9. Preparation and evaluation of aminopropyl-functionalized manganese-loaded SBA-15 for copper removal from aqueous solution.

    Science.gov (United States)

    Lei, Di; Zheng, Qianwen; Wang, Yili; Wang, Hongjie

    2015-02-01

    A novel material, aminopropyl-functionalized manganese-loaded SBA-15 (NH2-Mn-SBA-15), was synthesized by bonding 3-aminopropyl trimethoxysilane (APTMS) onto manganese-loaded SBA-15 (Mn-SBA-15) and used as a Cu2+ adsorbent in aqueous solution. Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction spectra (XRD), N2 adsorption/desorption isotherms, high resolution field emission scanning electron microscopy (FESEM) and X-ray photoelectron spectroscopy (XPS) were used to characterize the NH2-Mn-SBA-15. The ordered mesoporous structure of SBA-15 was remained after modification. The manganese oxides were mainly loaded on the internal surface of the pore channels while the aminopropyl groups were mainly anchored on the external surface of SBA-15. The adsorption of Cu2+ on NH2-Mn-SBA-15 was fitted well by the Langmuir equation and the maximum adsorption capacity of NH2-Mn-SBA-15 for Cu2+ was over two times higher than that of Mn-SBA-15 under the same conditions. The Elovich equation gave a good fit for the adsorption process of Cu2+ by NH2-Mn-SBA-15 and Mn-SBA-15. Both the loaded manganese oxides and the anchored aminopropyl groups were found to contribute to the uptake of Cu2+. The NH2-Mn-SBA-15 showed high selectivity for copper ions. Consecutive adsorption-desorption experiments showed that the NH2-Mn-SBA-15 could be regenerated by acid treatment without altering its properties.

  10. Spatial Fluctuations of Loose Spin Coupling in CuMn/Co Multilayers

    Science.gov (United States)

    Saerbeck, T.; Loh, N.; Lott, D.; Toperverg, B. P.; Mulders, A. M.; Rodríguez, A. Fraile; Freeland, J. W.; Ali, M.; Hickey, B. J.; Stampfl, A. P. J.; Klose, F.; Stamps, R. L.

    2011-09-01

    A detailed investigation of magnetic impurity-mediated interlayer exchange coupling observed in Cu0.94Mn0.06/Co multilayers using polarized neutron reflectometry and magnetic x-ray techniques is reported. Excellent descriptions of temperature and magnetic field dependent biquadratic coupling are obtained using a variant of the loose spin model that takes into account the distribution of the impurity Mn ions in three dimensions. Positional disorder of the magnetic impurities is shown to enhance biquadratic coupling via a new contribution J2fluct, leading to a temperature dependent canting of magnetic domains in the multilayer. These results provide measurable effects on RKKY coupling associated with the distribution of impurities within planes parallel to the interfaces.

  11. Correlation between K, Mn, Fe, Cu and Zn in natural honeys from Eucalyptus sources

    Directory of Open Access Journals (Sweden)

    Silvânia V. M. Mattos

    1998-01-01

    Full Text Available Thirty-five natural honey samples from three apicultural regions of the state of Minas Gerais, Brazil, were collected from honeybee hives under various climatic conditions over a two-year period. The beehives were located in the districts of Bom Jesus do Amparo, Barão de Cocais and São Gonçalo do Rio Abaixo, all within a 100 km radius of Belo Horizonte, Minas Gerais, Brazil. The pollinic spectrum, color and ash, moisture, K, Fe, Mn, Cu and Zn contents were determined. Elemental analysis were done by flame atomic absorption spectrometry. Accuracy and precision were verified by recovery tests and relative standard deviation, respectively. The mean mineral contents encountered were K = 1130; Mn = 3.88; Fe = 2.79; Zn = 2.34 and Cu = 0.54 µ g/g. During the dry season, several species of Eucalyptus pollen grains predominated, with Vernonia pollen grains present in lower abundance. In the rainy season, there was an inversion of dominance. Statistical treatment of results, separated according to comb and season, showed statistically equivalent means, although some good correlation indices (p = 0.05 were obtained, e.g. between percent Eucalyptus pollen grains and Mn content (0.450, between Fe and Zn (0.698 and between K and Mn (0.738.Foram coletadas 35 amostras de mel natural em diferentes condições climáticas, por um período de dois anos. Os apiários se localizavam nos distritos de Bom Jesus do Amparo, Barão de Cocais e São Gonçalo do Rio Abaixo, a cerca de 100 km de Belo Horizonte, a capital do Estado de Minas Gerais, Brasil. As amostras foram analisadas quanto aos teores de K, Fe, Mn, Cu, Zn, espectro polínico, cor, cinzas e umidade. As médias encontradas foram: K = 1130; Mn = 3,88; Fe = 2,79; Zn = 2,34 e Cu = 0,54 µ g/g. No período de seca houve predomínio de grãos de pólen de origem de espécies de Eucalyptus e, em menor extensão de Vernonia. No período chuvoso, houve uma inversão dessa proporção. O tratamento estat

  12. Fungal Growth and Manganese Peroxidase Production in a Deep Tray Solid-State Bioreactor, and In Vitro Decolorization of Poly R-478 by MnP.

    Science.gov (United States)

    Zhao, Xinshan; Huang, Xianjun; Yao, Juntao; Zhou, Yue; Jia, Rong

    2015-06-01

    The growth of Irpex lacteus F17 and manganese peroxidase (MnP) production in a selfdesigned tray bioreactor, operating in solid-state conditions at a laboratory scale, were studied. The bioreactor was divided into three layers by three perforated trays. Agroindustrial residues were used both as the carrier of bound mycelia and as a nutrient medium for the growth of I. lacteus F17. The maximum biomass production in the bioreactor was detected at 60 h of fermentation, which was consistent with the CO2 releasing rate by the fungus. During the stationary phase of fungal growth, the maximum MnP activity was observed, reaching 950 U/l at 84 h. Scanning electron microscopy images clearly showed the growth situation of mycelia on the support matrix. Furthermore, the MnP produced by I. lacteus F17 in the bioreactor was isolated and purified, and the internal peptide sequences were also identified with mass spectrometry. The optimal activity of the enzyme was detected at pH 7 and 25 °C, with a long half-life time of 9 days. In addition, the MnP exhibited significant stability within a broad pH range of 4-7 and at temperature up to 55 °C. Besides this, the MnP showed the ability to decolorize the polymeric model dye Poly R-478 in vitro.

  13. Lithium manganese oxide (LiMn2O4) nanoparticles synthesized by hydrothermal method as adsorbent of lithium recovery process from geothermal fluid of Lumpur Sidoarjo

    Science.gov (United States)

    Noerochim, Lukman; Sapputra, Gede Panca Ady; Widodo, Amien

    2016-04-01

    Lumpur Sidoarjo is one of geothermal fluid types which has a great potential as source of lithium. Adsorption method with Lithium Manganese Oxide (LiMn2O4) as an adsorbent has been chosen for lithium recovery process due to low production cost and environmental friendly. LiMn2O4 was synthesized by hydrothermal method at 200 °C for 24 hrs, 48 hrs, and 72 hrs. As prepared LiMn2O4 powder is treated by acid treatment with 0.5 M HCl solution for 24 hrs. XRD test result reveals that all of as-prepared samples are indexed as spinel structure of LiMn2O4 (JCPDS card no 35-0782) with no impurity peaks detected. SEM images show that LiMn2O4 has nanoparticles morphology with particle size around 25 nm. The highest adsorption efficiency of adsorbent is obtained by sample hydrothermal for 72 hrs with 42.76%.

  14. Disorder in the composite crystal structure of the manganese `disilicide' MnSi1.73 from powder X-ray diffraction data.

    Science.gov (United States)

    Akselrud, L; Cardoso Gil, R; Wagner-Reetz, M; Grin, Yu

    2015-12-01

    The crystal structure of the higher manganese silicide MnSi1.7 (known in the literature as HMS) is investigated in samples with different compositions obtained by different techniques at temperatures not higher than 1273 K. Powder X-ray diffraction was applied. The crystal structure is described as incommensurate composite. In addition to the ordered model already known in the literature, the partial disorder in the silicon substructure was detected and described introducing an additional atomic site with a different modulation function.

  15. Magnetic properties of CaCu5-type RNi3TSi (R=Gd and Tb, T=Mn, Fe, Co and Cu) compounds

    Science.gov (United States)

    Morozkin, A. V.; Knotko, A. V.; Yapaskurt, V. O.; Yao, Jinlei; Yuan, Fang; Mozharivskyj, Y.; Nirmala, R.; Quezado, S.; Malik, S. K.

    2015-12-01

    Magnetic properties and magnetocaloric effect of CaCu5-type RNi3TSi (R=Gd and Tb, T=Mn, Fe, Co and Cu) compounds have been investigated. Magnetic measurements of RNi3TSi display the increasing of Curie temperature and the decreasing of magnetocaloric effect and saturated magnetic moment in the row of 'RNi3CuSi-RNi3NiSi-RNi3CoSi-RNi3MnSi-RNi3FeSi'. In contrast to GdNi3{Mn, Fe, Co}Si, TbNi3{Mn, Fe, Co}Si exhibit significant magnetic hysteresis. The coercive field increases from TbNi4Si ( 0.5 kOe) to TbNi3CoSi (4 kOe), TbNi3MnSi (13 kOe) and TbNi3FeSi (16 kOe) in field of 50 kOe at 5 K, whereas TbNi3CuSi exhibits a negligible coercive field.

  16. Magnetic properties of CaCu{sub 5}-type RNi{sub 3}TSi (R=Gd and Tb, T=Mn, Fe, Co and Cu) compounds

    Energy Technology Data Exchange (ETDEWEB)

    Morozkin, A.V., E-mail: morozkin@tech.chem.msu.ru [Department of Chemistry, Moscow State University, Leninskie Gory, House 1, Building 3, GSP-2, Moscow 119992 (Russian Federation); Knotko, A.V. [Department of Chemistry, Moscow State University, Leninskie Gory, House 1, Building 3, GSP-2, Moscow 119992 (Russian Federation); Yapaskurt, V.O. [Department of Petrology, Geological Faculty, Moscow State University, Leninskie Gory, Moscow 119992 (Russian Federation); Yao, Jinlei [Research Center for Solid State Physics and Materials, School of Mathematics and Physics, Suzhou University of Science and Technology, Suzhou 215009 (China); Yuan, Fang; Mozharivskyj, Y. [Department of Chemistry and Chemical Biology, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada L8S 4M1 (Canada); Nirmala, R. [Indian Institute of Technology Madras, Chennai 600036 (India); Quezado, S.; Malik, S.K. [Departamento de Física Teórica e Experimental, Universidade Federal do Rio Grande do Norte, Natal 59082-970 (Brazil)

    2015-12-15

    Magnetic properties and magnetocaloric effect of CaCu{sub 5}-type RNi{sub 3}TSi (R=Gd and Tb, T=Mn, Fe, Co and Cu) compounds have been investigated. Magnetic measurements of RNi{sub 3}TSi display the increasing of Curie temperature and the decreasing of magnetocaloric effect and saturated magnetic moment in the row of ‘RNi{sub 3}CuSi–RNi{sub 3}NiSi–RNi{sub 3}CoSi–RNi{sub 3}MnSi–RNi{sub 3}FeSi’. In contrast to GdNi{sub 3}{Mn, Fe, Co}Si, TbNi{sub 3}{Mn, Fe, Co}Si exhibit significant magnetic hysteresis. The coercive field increases from TbNi{sub 4}Si (~0.5 kOe) to TbNi{sub 3}CoSi (4 kOe), TbNi{sub 3}MnSi (13 kOe) and TbNi{sub 3}FeSi (16 kOe) in field of 50 kOe at 5 K, whereas TbNi{sub 3}CuSi exhibits a negligible coercive field. - Graphical abstract: Magnetic measurements of RNi{sub 3}TSi show the increasing of Curie temperature and the decreasing of magnetocaloric effect and saturated magnetic moment in the row of 'RNi{sub 3}CuSi–RNi{sub 3}NiSi–RNi{sub 3}CoSi–RNi{sub 3}MnSi–RNi{sub 3}FeSi'. In contrast to GdNi{sub 3}{Mn, Fe, Co}Si, TbNi{sub 3}{Mn, Fe, Co}Si exhibit significant magnetic hysteresis. The coercive field increases from TbNi{sub 4}Si (~0.5 kOe) to TbNi{sub 3}CoSi (4 kOe), TbNi{sub 3}MnSi (13 kOe) and TbNi{sub 3}FeSi (16 kOe) in field of 50 kOe at 5 K, whereas TbNi{sub 3}CuSi exhibits a negligible coercive field. - Highlights: • CaCu{sub 5}-type RNi{sub 3}TSi show ferromagnetic ordering (R=Gd, Tb, T=Mn–Co, Cu). • Curie point increases in ‘RNi{sub 3}CuSi–RNi{sub 3}NiSi–RNi{sub 3}CoSi–RNi{sub 3}MnSi–RNi{sub 3}FeSi’ row. • MCE decreases in ‘RNi{sub 3}CuSi–RNi{sub 3}NiSi–RNi{sub 3}CoSi–RNi{sub 3}MnSi–RNi{sub 3}FeSi’ row. • TbNi{sub 3}{Mn, Fe, Co}Si exhibit significant magnetic hysteresis. • The coercive field of TbNi{sub 3}MnSi and TbNi{sub 3}FeSi reach 13 kOe and 16 kOe at 5 K.

  17. Imaging Current-Induced Switching of Antiferromagnetic Domains in CuMnAs

    Science.gov (United States)

    Grzybowski, M. J.; Wadley, P.; Edmonds, K. W.; Beardsley, R.; Hills, V.; Campion, R. P.; Gallagher, B. L.; Chauhan, J. S.; Novak, V.; Jungwirth, T.; Maccherozzi, F.; Dhesi, S. S.

    2017-02-01

    The magnetic order in antiferromagnetic materials is hard to control with external magnetic fields. Using x-ray magnetic linear dichroism microscopy, we show that staggered effective fields generated by electrical current can induce modification of the antiferromagnetic domain structure in microdevices fabricated from a tetragonal CuMnAs thin film. A clear correlation between the average domain orientation and the anisotropy of the electrical resistance is demonstrated, with both showing reproducible switching in response to orthogonally applied current pulses. However, the behavior is inhomogeneous at the submicron level, highlighting the complex nature of the switching process in multidomain antiferromagnetic films.

  18. Effect of environmental temperature on damping capacity of Cu-Al-Mn alloy

    Institute of Scientific and Technical Information of China (English)

    JIAO Yu-qin; WEN Yu-hua; LI Ning; HE Jia-qiang; TENG Jin

    2009-01-01

    The effect of environmental temperature on the damping capacity of Cu-7.66Al-9.52Mn (mass fraction, %) alloy was studied. The result shows that with increasing the environmental temperature, the logarithmic decrement increases firstly and reaches the maximal value of 0.118. The reason is that more phase interfaces and twinning boundaries can move at a higher temperature, leading to higher consumption of energy, in despite of the decreasing of the amount of martensite. When the environmental temperature is above Ms, with further increase in the environmental temperature, the logarithmic decrement decreases sharply mainly because there is little martensite remaining in the alloy.

  19. Metabolismo del Mg, Cu, Zn, Cr, Mn, y Ni en la diabetes melitus

    OpenAIRE

    1995-01-01

    En los últimos años, a los elementos traza y al mg se las ha implicado en la patologenesis de las complicaciones crónicas de la diabetes mellitus (dm). Las alteraciones del estado mineral asociadas a la dm podrían estar influidas, entre otros factores, por el grado de control metabólico y la asociación, o no, de otras patologías metabólicas como la hipertensión arterial (hta), la dislipemia y la obesidad. A pesar de que el mg, cu, zn, cr, mn y ni son cationes de localización principalmente in...

  20. Disorder in Al-li-cu and Al-mn-si icosahedral alloys.

    Science.gov (United States)

    Heiney, P A; Bancel, P A; Horn, P M; Jordan, J L; Laplaca, S; Angilello, J; Gayle, F W

    1987-10-30

    Faceted dendrites of icosahedral AL(6)Li(3)Cu have been studied by high-resolution x-ray scattering. The samples display long-range icosahedral symmetry both in their diffraction patterns and in their macroscopic morphology. Despite the appearance of well-defined facets, the samples have a high degree of atomic disorder. The Bragg peaks have symmetry-dependent shapes and widths that scale linearly with G perpendicular (phason momentum). The peak widths are surprisingly similar to those found in icosahedral Al-Mn-Si alloys in both their absolute magnitude and their dependence on G perpendicular. The origin of these features in models for the icosahedral phase is discussed.

  1. Cu, Mn, Fe, and Zn Levels in Soils of Shika Area, Nigeria

    Institute of Scientific and Technical Information of China (English)

    S. A. MASHI; S. A. YARO; A. S. HAIBA

    2004-01-01

    Heavy metals presented in toxic amounts can become injurious to human health. In areas where there is a high level of human activities on soils (such as agriculture and grazing) studies are therefore required from time to time to monitor levels of such metals in the soils in order to identify the point in time when toxicity problems become real. The 英文摘要: of this paper is to determine the concentrations of some trace metals (Cu, Mn, Fe, and Zn) in soils under cultivation and grazing practices in Shika, a rural area of Kaduna state of Nigeria. Method In this study, soil samples collected from three different categories of locations (cultivated, grazed, and uncultivated/non- grazed serving as a control) across Shika area, Nigeria, were analysed for some trace metal levels (Cu, Mn, Fe, and Zn) using atomic absorption spectrophotometry. For each category, multiple sites were chosen to accommodate all possible intra-category variations, especially in terms of land use and management history and topographic characteristics. Topsoil (0-15 cm) and subsoil (20-30 cm) samples were collected from every site and analysed for the above metals. Averaged values of the metals for the three categories revealed that Zn is the most abundant metal, followed by Fe, then Mn and Cu the least. Results The results obtained indicate that the cultivation practices, and to a lesser extent grazing, in the area result in higher levels of all the metals than in the control, suggesting that crop immobilization of the metals from soils of the area is low, and that their systematic accumulation is taking place in cultivated soils of the area. Prospects of having elevated soil levels of the metals due to cultivation practices in the area therefore seem quite high. Conclusion On the basis of the results obtained, it was concluded that grazing and cultivation practices have in general caused some significant elevations in the bioavailable (i.e the plant available forms) levels of Zn, Fe, Mn

  2. Synthesis, Crystal Structure and Spectrum Properties of Trinuclear Manganese Coordination Compound Mn3(2,2'-bipy)e(3,5-DMBA)6%Synthesis, Crystal Structure and Spectrum Properties of Trinuclear Manganese Coordination Compound Mn3(2,2'-bipy)e(3,5-DMBA)6

    Institute of Scientific and Technical Information of China (English)

    LI Wei; LI Chang-Hong; LI Yu-Lin; ZHANG Chun-Hua

    2012-01-01

    A novel complex Mn3(2,2'-bipy)ff3,5-DMBA)6 with 3,5-dimethylbenzoic acid (3,5-DMBA) and 2,2'-bipyridine (2,2'-bipy) has been synthesized by means of a solvent method. It crystallizes in the monoclinic space group C2/c with a = 3.1118(6), b = 1.1754(2), c = 2.0887(4) nm, β = 118.50(3)°, V= 6.714(2) nm3, Dc = 1.384 g/cm3, Z = 8, F(000) = 2912, the final GOOF = 1.078, R = 0.0691 and wR = 0.1455. The crystal structure shows that the three coordinated manganese(II) ions lie in a line with the middle one as the symmetric center. The distance between the central manganese(II) and the symmetric one is 0.3549 nm. There exist two coordination modes for the three manganese (II) ions: the symmetric manganese(II) ions are coordinated with three oxygen atoms and two nitrogen atoms from three 3,5-DMBA molecules and one 2,2'-bipy molecule, respectively, forming a distorted square-pyramidal coordination geometry; the middle manganese(II) ion is coordinated with six oxygen atoms from six 3,5-DMBA molecules, generating a distorted octahedral coordination geometry. Spectrum properties of the complex were also studied.

  3. Complexes of arabinogalactan of Pereskia aculeata and Co2+, Cu2+, Mn2+, and Ni2+.

    Science.gov (United States)

    Merce, A L; Landaluze, J S; Mangrich, A S; Szpoganicz, B; Sierakowski, M R

    2001-01-01

    The main interest in the biopolymer arabinogalactan is that it is edible. Complementing its high protein percentage, when complexed to essential metal ions, widens the use in food and pharmacology industries and technologies. The binding constants of Co2+, Cu2+, Mn2+ and Ni2+ with arabinogalactan, extracted from the leaves of Pereskia aculeata from Brazil were determined by potentiometric titrations and also the speciation according to pH values. The complexed species proposed by potentiometric titrations and the unique complexing ability of galacturonic acid groups towards Cu2+ and Ni2+ in the tridimensional web structure of arabinogalactan were confirmed by IR and EPR spectroscopies. The thermal stability of the complexed species also varied with the metal ion employed in the complexation when compared to the biopolymer alone. These complexes are new sources of additives for the food and pharmacology industries and carriers of essential metal ions to animal and vegetal biochemistry.

  4. The effect of the substitution of Cu for Mn on magnetic and magnetocaloric properties of Ni{sub 50}Mn{sub 34}In{sub 16}

    Energy Technology Data Exchange (ETDEWEB)

    Kaya, M. [Department of Engineering Physics, Faculty of Engineering, Ankara University, 06100 Besevler, Ankara (Turkey); Yildirim, S. [Nanotechnology and Nanomedicine Division, Hacettepe University, Ankara 06800 (Turkey); Yüzüak, E. [Department of Engineering Physics, Faculty of Engineering, Ankara University, 06100 Besevler, Ankara (Turkey); Department of Nanotechnology Engineering, Faculty of Engineering, Recep Tayyip Erdogan University, 53100 Rize (Turkey); Dincer, I., E-mail: idincer@eng.ankara.edu.tr [Department of Engineering Physics, Faculty of Engineering, Ankara University, 06100 Besevler, Ankara (Turkey); Ellialtioglu, R. [Department of Engineering Physics, Faculty of Engineering Hacettepe University, Ankara 06800 (Turkey); Elerman, Y. [Department of Engineering Physics, Faculty of Engineering, Ankara University, 06100 Besevler, Ankara (Turkey)

    2014-11-15

    The influence of Cu substitution for Mn on magnetic and magnetocaloric properties has been investigated in Ni{sub 50}Mn{sub 34−x}Cu{sub x}In{sub 16} (x=1.3 and 1.6) Heusler alloys by using calorimetric and magnetic measurements. The temperature dependent magnetization measurements and calorimetric studies indicate that martensitic transition temperatures shift to higher temperatures with increasing valence electron concentrations, e/a. The isothermal magnetization curves around the martensitic transition temperatures show a typical metamagnetic behavior. Associated with that, large positive values of magnetic entropy changes around structural transition region were determined by using the Maxwell and Clausius–Clapeyron relations. The maximum magnetic entropy change values were found to be 25.2 and 5.7 J kg{sup −1} K{sup −1} for Ni{sub 50}Mn{sub 34−x}Cu{sub x}In{sub 16} (x=1.3 and 1.6) alloys by Maxwell relation in a magnetic field change of 2 T. In order to understand the limit can be reached for, the magnetic entropy change values recalculated by Clausius–Clapeyron relation. Obtained maximum entropy change values are 22.8 and 16.3 J kg{sup −1} K{sup −1} for Ni{sub 50}Mn{sub 34−x}Cu{sub x}In{sub 16} (x=1.3 and 1.6) alloys by Clausius–Clapeyron relation. - Highlights: • Ni{sub 50}Mn{sub 34−x}Cu{sub x}In{sub 16} alloys are prepared by an arc-melting method. • Structural properties are characterized by XRD, DSC and SEM. • Magnetic entropy change values are estimated by Maxwell and Clausius–Clapeyron equations.

  5. X-ray absorption study of the ferromagnetic Cu moment at the YBa2Cu3O7/La2 /3Ca1 /3MnO3 interface and variation of its exchange interaction with the Mn moment

    Science.gov (United States)

    Sen, K.; Perret, E.; Alberca, A.; Uribe-Laverde, M. A.; Marozau, I.; Yazdi-Rizi, M.; Mallett, B. P. P.; Marsik, P.; Piamonteze, C.; Khaydukov, Y.; Döbeli, M.; Keller, T.; Biškup, N.; Varela, M.; Vašátko, J.; Munzar, D.; Bernhard, C.

    2016-05-01

    With x-ray absorption spectroscopy and polarized neutron reflectometry we studied how the magnetic proximity effect at the interface between the cuprate high-TC superconductor YBa2Cu3O7 (YBCO) and the ferromagnet La2 /3Ca1 /3MnO3 (LCMO) is related to the electronic and magnetic properties of the LCMO layers. In particular, we explored how the magnitude of the ferromagnetic Cu moment on the YBCO side depends on the strength of the antiferromagnetic (AF) exchange coupling with the Mn moment on the LCMO side. We found that the Cu moment remains sizable if the AF coupling with the Mn moments is strongly reduced or even entirely suppressed. The ferromagnetic order of the Cu moments thus seems to be intrinsic to the interfacial CuO2 planes and related to a weakly ferromagnetic intraplanar exchange interaction. The latter is discussed in terms of the partial occupation of the Cu 3 d3 z2-r2 orbitals, which occurs in the context of the so-called orbital reconstruction of the interfacial Cu ions.

  6. Periodic trends within a series of five-coordinate thiolate-ligated [MII(SMe2N4(tren))]+ (M = Mn, Fe, Co, Ni, Cu, Zn) complexes, including a rare example of a stable CuII-thiolate.

    Science.gov (United States)

    Brines, Lisa M; Shearer, Jason; Fender, Jessica K; Schweitzer, Dirk; Shoner, Steven C; Barnhart, David; Kaminsky, Werner; Lovell, Scott; Kovacs, Julie A

    2007-10-29

    A series of five-coordinate thiolate-ligated complexes [M(II)(tren)N4S(Me2)]+ (M = Mn, Fe, Co, Ni, Cu, Zn; tren = tris(2-aminoethyl)amine) are reported, and their structural, electronic, and magnetic properties are compared. Isolation of dimeric [Ni(II)(SN4(tren)-RS(dang))]2 ("dang"= dangling, uncoordinated thiolate supported by H bonds), using the less bulky [(tren)N4S](1-) ligand, pointed to the need for gem-dimethyls adjacent to the sulfur to sterically prevent dimerization. All of the gem-dimethyl derivatized complexes are monomeric and, with the exception of [Ni(II)(S(Me2)N4(tren)]+, are isostructural and adopt a tetragonally distorted trigonal bipyramidal geometry favored by ligand constraints. The nickel complex uniquely adopts an approximately ideal square pyramidal geometry and resembles the active site of Ni-superoxide dismutase (Ni-SOD). Even in coordinating solvents such as MeCN, only five-coordinate structures are observed. The MII-S thiolate bonds systematically decrease in length across the series (Mn-S > Fe-S > Co-S > Ni-S approximately Cu-S tren)]+, represents a rare example of a stable CuII-thiolate, and models the perturbed "green" copper site of nitrite reductase. In contrast to the intensely colored, low-spin Fe(III)-thiolates, the M(II)-thiolates described herein are colorless to moderately colored and high-spin (in cases where more than one spin-state is possible), reflecting the poorer energy match between the metal d- and sulfur orbitals upon reduction of the metal ion. As the d-orbitals drop in energy proceeding across the across the series M(2+) (M= Mn, Fe, Co, Ni, Cu), the sulfur-to-metal charge-transfer transition moves into the visible region, and the redox potentials cathodically shift. The reduced M(+1) oxidation state is only accessible with copper, and the more oxidized M(+4) oxidation state is only accessible for manganese.

  7. Mechanisms of Mn(II) catalytic oxidation on ferrihydrite surfaces and the formation of manganese (oxyhydr)oxides

    Science.gov (United States)

    Lan, Shuai; Wang, Xiaoming; Xiang, Quanjun; Yin, Hui; Tan, Wenfeng; Qiu, Guohong; Liu, Fan; Zhang, Jing; Feng, Xionghan

    2017-08-01

    Oxidation of Mn(II) is an important process that controls the mobility and bioavailability of Mn, as well as the formation of Mn (oxyhydr)oxides in natural systems. It was found that the surfaces of minerals, such as iron (oxyhydr)oxides, can accelerate Mn(II) oxidation to a certain degree, but the underlying mechanism has not been clearly understood. This study explores the reaction pathways and mechanisms of Mn(II) oxidation on ferrihydrite surfaces at neutral pH, commonly found in natural environments, by comparisons with montmorillonite, amorphous Al(OH)3, goethite, and magnetite using macroscopic experiments and spectroscopic analyses. Results show that when Mn(II) concentrations are below 4 mM, macroscopic Mn(II) adsorption on the three iron (oxyhydr)oxide surfaces conforms well to the Langmuir equation, with ferrihydrite showing the highest adsorption capacity. With Mn(II) concentrations ranging within 6-24 mM, the adsorbed Mn(II) is mainly oxidized into manganite (γ-MnOOH) and/or feitknechtite (β-MnOOH) by dissolved O2, and Mn(II) removal on a unit mass basis in the presence of magnetite is the highest compared with ferrihydrite and goethite. Ferrihydrite, a semiconductor material, shows stronger catalytic ability for Mn(II) oxidation on the same surface area than insulator minerals (i.e., montmorillonite and amorphous Al(OH)3). Additionally, the products of Mn(II) oxidation in the presence of semiconductor iron (oxyhydr)oxides (i.e., ferrihydrite, goethite, or magnetite) at the same Fe/Mn molar ratio include both manganite and a small amount of Mn(IV) minerals, and the Mn average oxidation states (Mn AOSs) of these products follow the order: magnetite > goethite > ferrihydrite. Magnetite and goethite, with relatively smaller SSAs and lower band gap energies, exhibit greater catalysis for Mn(II) oxidation than ferrihydrite at the same Fe/Mn ratio, which goes against the conventional interfacial effect and is related to the electrochemical properties. Thus

  8. Manganese-containing periodic mesoporous organosilica with ionic-liquid framework (Mn@PMO-IL): A powerful, durable, and reusable nanocatalyst for the Biginelli reaction.

    Science.gov (United States)

    Elhamifar, Dawood; Shábani, Ahmad

    2014-03-10

    The catalytic application of a novel manganese-containing periodic mesoporous organosilica with ionic-liquid framework (Mn@PMO-IL) in the Biginelli reaction was investigated. First, the Mn@PMO-IL nanocatalyst was prepared and characterized by TEM, SEM, X-ray photoelectron spectroscopy, and nitrogen-sorption analysis. The catalyst was then used in the one-pot Biginelli condensation of various aldehydes with urea and alkyl acetoacetates under solvent-free conditions. The corresponding dihydropyrimidone products were obtained in high to excellent yields and selectivities at short reaction times. Moreover, the catalyst was recovered and successfully reused many times with no notable decrease in activity and selectivity. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Comparative study of supported CuOx and MnOx catalysts for the catalytic wet air oxidation of β-naphthol

    Science.gov (United States)

    Liu, Jie; Yu, Chaoying; Zhao, Peiqing; Chen, Gexin

    2012-09-01

    MnOx/nano-TiO2, MnOx/Al2O3-TiO2 (Al-Ti), CuOx/nano-TiO2 and CuOx/Al-Ti were prepared and their application in catalytic wet air oxidation (CWAO) of β-naphthol were investigated. The catalysts had been characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and temperature-programmed reduction (TPR) measurements. Phases of CuO, Cu2O, CuAl2O4, MnO2 and Mn2O3 could be found on the surface of the aforementioned catalysts. Significant differences in activities were observed among the prepared catalysts. Compared to CuOx/nano-TiO2, the combined action of highly dispersed CuO as well as CuAl2O4 of CuOx/Al-Ti helped to achieve higher activity for the CWAO of β-naphthol, while the Cu2O component lead to lower efficiency of CuOx/nano-TiO2. On the surface of MnOx/nano-TiO2, both the larger amount of highly dispersed MnO2 and the stronger electron transfer between MnO2 and Mn2O3 were helpful to promote the activity for the degradation of β-naphthol. However, the higher amount of bulk MnO2 and the weaker electron transfer for MnOx/Al-Ti were unfavorable to increase its efficiency. Among the four catalysts as-prepared, MnOx/nano-TiO2 was identified the highest activity with 93.7% COD removal.

  10. Influence of Mn substitution on microstructure and magnetic properties of Cu1-xMnxO nanoparticles

    Science.gov (United States)

    Rao, G. Narsinga; Yao, Y. D.; Chen, J. W.

    2007-05-01

    Mn-doped CuO nanoparticles were synthesized using a coprecipitation method. Powder x-ray analysis reveals that all the samples crystallize into a monoclinic-type structure. Significant changes occur in both the microstructure and particle size with calcination temperature TA. The average particle size d increases from 11to85nm as the TA increases from 250to850°C. For particles of size d ⩽22nm, energy dispersive spectroscopy indicates the existence of a crystalline Cu1-xMnxO core surrounded by an amorphous CuO shell. M(T ) curves reveal a spin-glass behavior for the 11 and 22nm particles and a ferromagnetic behavior for particles of size d ⩾35nm. The observed ferromagnetic behavior is attributed to the coexistence of Mn2+ and Mn3+ ions.

  11. High temperature EPR study of the M3Fe4V6O24 (M = Cu, Zn, Mg and Mn

    Directory of Open Access Journals (Sweden)

    Guskos Niko

    2016-09-01

    Full Text Available Electron paramagnetic resonance (EPR spectra of M3Fe4V6O24 (M = Cu, Zn, Mg and Mn compounds in high temperature range (293 K to 493 K have been investigated. The role of magnetic (Cu, Mn and non-magnetic (Zn, Mg ions in M3Fe4V6O24 structure in formation of magnetic resonance spectra was studied. Temperature dependence of EPR parameters: resonance field, linewidth and integrated intensity were examined. Similarities and differences in temperature behavior of these parameters has been discussed in terms of different relaxation mechanisms and magnetic interactions in the spin systems. An important role of additional magnetic ions (M = Mn or Cu in the M3Fe4V6O24 structure has been identified and its consequences considered.

  12. Application of Cu-Al-Mn superelastic alloy bars as reinforcement elements in concrete beams

    Science.gov (United States)

    Shrestha, Kshitij C.; Araki, Yoshikazu; Nagae, Takuya; Yano, Hayato; Koetaka, Yuji; Omori, Toshihiro; Sutou, Yuji; Kainuma, Ryosuke; Ishida, Kiyohito

    2012-04-01

    Experimental works are done to assess the seismic behavior of concrete beams reinforced with superelastic alloy (SEA) bars. Applicability of newly developed Cu-Al-Mn SEA bars, characterized by large recovery strain, low material cost, and high machinability, have been proposed as partial replacements for conventional steel bars in order to reduce residual deformations in structures during and after intense earthquakes. Four-point reverse-cyclic bending tests were done on 1/3 scale concrete beams comprising three different types of specimens - conventional steel reinforced concrete (ST-RC), SEA reinforced concrete (SEA-RC), and SEA reinforced concrete with pre-tensioning (SEA-PC). The results showed that SEA reinforced concrete beams demonstrated significant enhancement in crack recovery capacity in comparison to steel reinforced beam. Average recovery of cracks for each of the specimens was 21% for ST-RC, 84% for SEA-RC, and 86% for SEA-PC. In addition, SEA-RC and SEA-PC beams demonstrated strong capability of recentering with comparable normalized strength and ductility relative to conventional ST-RC beam specimen. ST-RC beam, on the other hand, showed large residual cracks due to progressive reduction in its re-centering capability with each cycle. Both the SEA-RC and SEA-PC specimens demonstrated superiority of Cu-Al-Mn SEA bars to conventional steel reinforcing bars as reinforcement elements.

  13. Slurry Erosion Behavior of Destabilized and Deep Cryogenically Treated Cr-Mn-Cu White Cast Irons

    Directory of Open Access Journals (Sweden)

    S. Gupta

    2016-12-01

    Full Text Available The effects of destabilization treatment and destabilization followed by cryogenic treatment have been evaluated on the microstructural evolution and sand-water slurry erosion behavior of Cr-Mn-Cu white cast irons. The phase transformations after the destabilization and cryotreatment have been characterized by bulk hardness measurement, optical and scanning electron microscopy, x-ray diffraction analysis. The static corrosion rate has been measured in tap water (with pH=7 and the erosion-corrosion behavior has been studied by slurry pot tester using sand-water slurry. The test results indicate that the cryogenic treatment has a significant effect in minimizing the as-cast retained austenite content and transforming into martensitic and bainitic matrix embedded with ultra-fine M7C3 alloy carbides. In contrast, by conventional destabilization treatment retained austenite in the matrix are not fully eliminated. The slurry erosive wear resistance has been compared with reference to destabilized and cryotreated high chromium iron samples which are commonly employed for such applications. The cryotreated Cr-Mn-Cu irons have exhibited a comparable erosive wear performance to those of high chromium irons. Higher hardness combined with improved corrosion resistance result in better slurry erosion resistance.

  14. XRD and XANES study of some Cu-doped MnBi materials

    Science.gov (United States)

    Mishra, Ashutosh; Patil, Harsha

    2016-10-01

    High purity MnBi low temperature phase has been prepared and analyzed using X- ray diffraction (XRD) and X-ray absorption near edge structure (XANES) measurements. The X-ray diffraction measurements were carried out using Bruker D8 Advance X-ray diffractometer. The X-rays were produced using a sealed tube and the wavelength of X-ray was 154 nm (Cu K-alpha). and X-rays were detected using a fast counting detector based on Silicon strip technology (Bruker LynxEye detector)[1]. and the X-ray absorption spectra has emerged as a powerful technique for local structure determination, which can be applied to any type of material. The X-ray absorption measurements of two Cu-doped MnBi alloys have been performed at the recently developed BL-8 Dispersive EXAFS beam line at 2.5 GeV Indus-2 synchrotron at RRCAT, Indore, India[2]. The X-ray absorption near edge structure (XANES) data obtained has been processed using data analysis program Athena. The energies of the K absorption edge, chemical shifts, edge-widths, shifts of the principal absorption maximum in the alloys have been determined.

  15. Structural and dielectric properties of Mn doped copper oxide (CuO) nanostructure

    Science.gov (United States)

    Khan, Imran; Khan, Shakeel; Ahmed, Hilal; Nongjai, Razia

    2013-06-01

    Undoped and Mn doped CuO nanocrystalline powder samples were prepared through standard solid state reaction method. The crystal structures of the CuO nanoparticles were characterized by X-ray diffraction. Dielectric measurements were performed on samples as a function of frequency at room temperate to determine the dielectric behavior of the samples. XRD data exhibited the presence of monoclinic crystal structure similar to the parent compound in all samples, suggesting that doped Mn ions sit at the regular lattice sites. The average crystallite size, calculated using Scherrer formula from XRD data, is found within the range of 23-27 nm. The dielectric constant (ɛ'), imaginary part of dielectric constant (ɛ") and loss tangent (tanδ) were studied as a function of frequency and composition at room temperature. The dependence of dielectric constant (ɛ') on frequency suggests a conduction mechanism in terms of hopping. This behavior can be explained on the basis of space charge polarization according to Maxwell and Wagner's two-layer model.

  16. DETERMINATION OF Cu, Fe, Mn, Zn AND FREE FATTY ACIDS IN PEQUI OIL

    Directory of Open Access Journals (Sweden)

    Aparecida M. S. Mimura

    2016-06-01

    Full Text Available Pequi (Caryocar brasiliense Camb., a typical fruit of the Brazilian Cerrado, is an important source of micronutrients and fatty acids. In this work, a new approach for the acid digestion (using H2SO4, HNO3 and H2O2 of pequi oil samples and the determination of Cu, Fe, Zn and Mn by flame atomic absorption spectrometry (F AAS was employed. Capillary zone electrophoresis (CZE was used for free fatty acid (FFA determination after simple and fast extraction with heated ethanol. Good results regarding precision (RSD < 10%, in most cases, sensitivity and adequate LOD and LOQ values were obtained. The accuracy was evaluated using spike tests and the recoveries were from 97 to 107%. The analytes were investigated in four different pequi oil samples. Fe was the trace element with the highest concentration (from 1.99 to 10.3 mg/100 g, followed by Zn, Mn and Cu (1.15 to 3.19, 0.42 to 0.91 and 0.31 to 0.56 mg/100 g, respectively. The main FFA found were oleic acid and palmitic acid (1.61 to 10.7 and 0.82 to 2.69 g/100 g, respectively, while linoleic acid (0.50 g/100 g was detected in only one sample. The pequi oil chemical composition showed good characteristics to be used as a food additive, in cosmetic formulations and for traditional medicine.

  17. A free-cutting and ductile CuAlMnZnTiB shape memory alloy

    Institute of Scientific and Technical Information of China (English)

    刘娜; 李周; 李灵; 刘斌; 李擎天; 徐根应

    2015-01-01

    The mechanical properties and cutting performance of the designed CuAlMnZnTiB shape memory alloy were studied by tensile test and microstructure observation. Using X-ray diffractometry, differential scanning calorimetry (DSC) and semi-quantitative shape memory effect test, the microstructure and shape memory effect were analyzed. It is found that lots ofβ phase and fewα phase are formed in the quenching of Cu-7.5Al-9.7Mn-3.4Zn-0.3Ti-0.14B (mass fraction, %) alloy, a great deal of martensite and fewα phase are formed in the aging alloy, while the annealing alloy is composed of a great deal ofα phase and fewβ phase. The tensile strength and elongation of the annealed alloy are 649 MPa and 17.1%, respectively. Some tiny and dispersion distributed second phase particles are generated in Ti and B precipitates, greatly improving the alloy machinability.

  18. Accumulative Roll Bonding and Post-Deformation Annealing of Cu-Al-Mn Shape Memory Alloy

    Science.gov (United States)

    Moghaddam, Ahmad Ostovari; Ketabchi, Mostafa; Afrasiabi, Yaser

    2014-12-01

    Accumulative roll bonding is a severe plastic deformation process used for Cu-Al-Mn shape memory alloy. The main purpose of this study is to investigate the possibility of grain refinement of Cu-9.5Al-8.2Mn (in wt.%) shape memory alloy using accumulative roll bonding and post-deformation annealing. The alloy was successfully subjected to 5 passes of accumulative roll bonding at 600 °C. The microstructure, properties as well as post-deformation annealing of this alloy were investigated by optical microscopy, scanning electron microscopy, x-ray diffraction, differential scanning calorimeter, and bend and tensile testing. The results showed that after 5 passes of ARB at 600 °C, specimens possessed α + β microstructure with the refined grains, but martensite phases and consequently shape memory effect completely disappeared. Post-deformation annealing was carried out at 700 °C, and the martensite phase with the smallest grain size (less than 40 μm) was obtained after 150 s of annealing at 700 °C. It was found that after 5 passes of ARB and post-deformation annealing, the stability of SME during thermal cycling improved. Also, tensile properties of alloys significantly improved after post-deformation annealing.

  19. From which soil metal fractions Fe, Mn, Zn and Cu are taken up by olive trees (Olea europaea L., cv. 'Chondrolia Chalkidikis') in organic groves?

    Science.gov (United States)

    Chatzistathis, T; Papaioannou, A; Gasparatos, D; Molassiotis, A

    2017-12-01

    Organic farming has been proposed as an alternative agricultural system to help solve environmental problems, like the sustainable management of soil micronutrients, without inputs of chemical fertilizers. The purposes of this study were: i) to assess Fe, Mn, Zn and Cu bioavailability through the determination of sequentially extracted chemical forms (fractions) and their correlation with foliar micronutrient concentrations in mature organic olive (cv. 'Chondrolia Chalkidikis') groves; ii) to determine the soil depth and the available forms (fractions) by which the 4 metals are taken up by olive trees. DTPA extractable (from the soil layers 0-20, 20-40 and 40-60 cm) and foliar micronutrient concentrations were determined in two organic olive groves. Using the Tessier fractionation, five fractions, for all the metals, were found: exchangeable, bound to carbonates (acid-soluble), bound to Fe-Mn oxides (reducible), organic (oxidizable), as well as residual form. Our results indicated that Fe was taken up by the olive trees as organic complex, mainly from the soil layer 40-60 cm. Manganese was taken up from the exchangeable fraction (0-20 cm); Zinc was taken up as organic complex from the layers 0-20 and 40-60 cm, as well as in the exchangeable form from the upper 20 cm. Copper was taken up from the soil layers 0-20 and 40-60 cm as soluble organic complex, and as exchangeable ion from the upper 20 cm. Our data reveal the crucial role of organic matter to sustain metal (Fe, Zn and Cu) uptake -as soluble complexes-by olive trees, in mature organic groves grown on calcareous soils; it is also expected that these data will constitute a thorough insight and useful tool towards a successful nutrient and organic C management for organic olive groves, since no serious nutritional deficiencies were found. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Efeitos da suplementação de fitase sobre a disponibilidade aparente de Mg, Ca, Zn, Cu, Mn e Fe em alimentos vegetais para a tilápia-do-nilo Effects of phytase supplementation on apparent availability of Mg, Ca, Zn, Cu, Mn, and Fe of plant feedstuffs for nile tilapia

    Directory of Open Access Journals (Sweden)

    Giovani Sampaio Gonçalves

    2005-12-01

    Full Text Available Cem juvenis de tilápia-do-nilo (Oreochromis niloticus; PV = 100.0 ± 5.0 g foram distribuídos em 10 tanques-rede com o objetivo de avaliar o efeito da suplementação da enzima fitase (0, 1.000 e 2.000 UFA/kg sobre a disponibilidade de minerais em alguns alimentos energéticos (milho, milho extrusado, farelo de trigo, farelo de arroz e farelo de sorgo e protéicos (farelo de soja extrusado, farelo de soja, farelo de girassol, farelo de algodão e glúten de milho utilizados na alimentação de tilápia-do-nilo (Oreochromis niloticus. Para determinação dos coeficientes de disponibilidade aparente (CDA do cálcio (Ca, magnésio (Mg, zinco (Zn, cobre (Cu, ferro (Fe e manganês (Mn, foram confeccionadas 31 rações, marcadas com 0,10% de óxido de crômio III uma referência (ração purificada e 30 contendo os dez alimentos e os diferentes níveis de suplementação da enzima fitase. O CDA dos nutrientes foi calculado com base no teor de crômio da ração e das fezes. A fitase aumenta, nos vegetais, a disponibilidade do Mg, Cu, Zn e Mn, os quais apresentam tendência diferenciada, em razão do seu valor biológico e do nível de suplementação de enzima.One hundred Nile tilapia juveniles (Oreochromis niloticus; BW= 100.0 ± 5.0 g were assigned to 10 experimental cages to evaluate the effects of phytase supplementation (0, 1,000, and 2,000 FTU/kg on calcium (Ca, magnesium (Mg, zinc (Zn, copper (Cu, iron (Fe and manganese (Mn availability of ten feedstuffs: five energetic (corn, extruded corn, wheat meal, rice meal and low-tannin sorghum and five protein (extruded soybean, soybean meal, sunflower meal, cottonseed meal and corn gluten meal. As reference, an albumin and gelatin-based diet [with 0.10 % chromic oxide (III as external marker] was fed to the juveniles. Thirty-one diets (one reference and 30 based on all feedstuffs and increasing levels of phytase were formulated to determine the coefficients of apparent availability of minerals (Mg

  1. Microstructures and Mechanical Properties of Helical Bevel Gears Made by Mn-Cu Alloyed Austempered Ductile Iron

    Institute of Scientific and Technical Information of China (English)

    LIU Sheng-fa; CHEN Yang; CHEN Xin; MIAO Hua-ming

    2012-01-01

    Austempered ductile iron (ADI) has several advantages of replacing cast steel and forged steel in many engineering fields. A new Mn-Cu alloyed ADI with excellent mechanical properties has been developed in order to cut the cost and enlarge the application of ADI. The helical bevel gears were made of the new-developed Mn-Cu alloyed ADI. The microstructure and mechanical properties of the standard sample were investigated by optical microscope (OM), scanning electron microscope (SEM) and performance measurement. The results showed that after a series of treatments, the mechanical properties (Rm 1007. 4 to 1200 MPa, A 5.2% to 8. 8%, HRC 32 to HRC 35, O~K 70 to 120 J/cmz ) of the Mn-Cu alloyed ADI standard sample could reach European standard EN1564-97/ EN-CJS-1000-5. The surface hardness after helical bevel gears meshing was significantly increased due to the formation of martensite. The bench test and traffic running testing results suggested that the new Mn-Cu alloyed ADI with ultimate life and median life respectively exceeding 30×104 and 50 × 10^4 times could replace 20CrMnTi forged steel for manufacturing the EQ140 helical bevel gears.

  2. Synthesis, Characterization and in Vitro Evaluation of Manganese Ferrite (MnFe2O4) Nanoparticles for Their Biocompatibility with Murine Breast Cancer Cells (4T1).

    Science.gov (United States)

    Kanagesan, Samikannu; Aziz, Sidek Bin Ab; Hashim, Mansor; Ismail, Ismayadi; Tamilselvan, Subramani; Alitheen, Noorjahan Banu Binti Mohammed; Swamy, Mallappa Kumara; Purna Chandra Rao, Bandaru

    2016-03-11

    Manganese ferrite (MnFe2O4) magnetic nanoparticles were successfully prepared by a sol-gel self-combustion technique using iron nitrate and manganese nitrate, followed by calcination at 150 °C for 24 h. Calcined sample was systematically characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and vibrational sample magnetometry (VSM) in order to identify the crystalline phase, functional group, morphology, particle size, shape and magnetic behavior. It was observed that the resultant spinal ferrites obtained at low temperature exhibit single phase, nanoparticle size and good magnetic behavior. The study results have revealed the existence of a potent dose dependent cytotoxic effect of MnFe2O4 nanoparticles against 4T1 cell lines at varying concentrations with IC50 values of 210, 198 and 171 μg/mL after 24 h, 48 h and 72 h of incubation, respectively. Cells exposed to higher concentrations of nanoparticles showed a progressive increase of apoptotic and necrotic activity. Below 125 μg/mL concentration the nanoparticles were biocompatible with 4T1 cells.

  3. Apoferritin-templated biosynthesis of manganese nanoparticles and investigation of direct electron transfer of MnNPs-HsAFr at modified glassy carbon electrode.

    Science.gov (United States)

    Rafipour, Ronak; Kashanian, Soheila; Hashemi, Sadegh; Omidfar, Kobra; Ezzati Nazhad Dolatabadi, Jafar

    2017-01-01

    Manganese nanoparticles (MnNPs) were created within horse spleen apoferritin (HsAFr) cavity nanotemplates. Transmission electron microscopy revealed the particle size to be 6 nm. Intrinsic fluorescence data showed that the mineralization acted as a quencher of the HsAFr fluorescence, and extrinsic fluorescence data revealed that the hydrophobic binding site at the surface of HsAFr was not changed. Finally, the MnNP-HsAFr was immobilized onto multiwalled carbon nanotubes entrapped into chitosan (CS) matrices by through sequential 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide-N-hydroxysuccinimide and glutaraldehyde coupling. The MnNPs-HsAFr immobilized on CNT-CS/GC electrode was characterized by cyclic voltammetry. This charge transfer coefficient (α) and the exchange current (i0 ) of MnNPs-HsAFr immobilized on modified electrode in 0.1 M phosphate solution (pH 7.5) were found to be 0.57 and 0.48 μA, respectively. © 2015 International Union of Biochemistry and Molecular Biology, Inc.

  4. Crystal Structure and Magnetic Property of a Two-dimensional Manganese Compound [Mn(PhCOO)2(4,4'-bipyridine)]n

    Institute of Scientific and Technical Information of China (English)

    CHEN Hui; WANG Wen-Guo; MA Cheng-Bing; CHEN Chang-Neng; LIU Qiu-Tian; LIAO Dai-Zheng; LI Li-Cun

    2007-01-01

    A new two-dimensional polymeric manganese compound [Mn(PhCOO)2(4,4'-bipyridine)]n 1 has been prepared and structurally characterized by X-ray diffraction. The complex crystallizes in space group Pbcn with a = 18.7158(2), b = 11.6919(3), c = 9.4799(2)(A), V = 2074.42(7)(A)3, Z = 4, Mr = 453.34, Dc = 1.452 g/cm3, μ = 0.670 mm-1 and F(000) = 932. The final refinement gave R = 0.0458 and wR = 0.1439 for 1358 observed reflections with Ⅰ> 2σ(Ⅰ). The complex consists of repeating units of Mn(PhCOO)2(4,4'-bipyridine). Each Mn center is sixcoordinated by four carboxylate O atoms of four benzoate anions and two pyridyl N atoms from bipy ligands to furnish a slightly distorted octahedral geometry. The two adjacent Mn atoms are connected by a pair of μ1,3-carboxylate groups to form infinite chains, which are further interlinked by bipy to complete a 2D grid network. The magnetic property of the polymeric complex has also been investigated.

  5. Heterogeneous UV/Fenton catalytic degradation of wastewater containing phenol with Fe-Cu-Mn-Y catalyst

    Institute of Scientific and Technical Information of China (English)

    郑展望; 雷乐成; 徐生娟; 岑沛霖

    2004-01-01

    The heterogeneous UV/Fenton process with the appropriate amount of Fe-Mn-Cu-Y as catalyst was developed and various operation conditions for the degradation of phenol were evaluated. The results indicated that by using the heterogeneous UV/Fenton process, the CODcr removal rate reached almost 100% for wastewater containing phenol. Compared with the homogeneous process, the developed catalyst could be used at wider pH range in the UV/Fenton process. Comparison of various heterogeneous process showed that heterogeneous UV/Fenton process was best. The heterogeneous UV/Fenton process with Fe-Mn-Cu-Y catalyst is highly efficient in degrading various organic pollutants.

  6. Investigation of deformation and microstructure of bainite in Cu-9.97%Al-4.62%mn alloy

    Directory of Open Access Journals (Sweden)

    Aldirmaz E.

    2014-01-01

    Full Text Available In this study, some physical and mechanical properties in Cu-9.97%Al-4.62%Mn (wt% alloy were investigated by X-ray diffraction (XRD, Scanning Electron Microscopy (SEM and compression deformation test. Bainite phase were obtained in the samples according to SEM and XRD analyses. Compression stress was applied on the alloy in order to investigate the deformation effect on the bainite phase transformation. On the surface of the Cu-9.97%Al-4.62%Mn alloy after the deformation, both bainite and martensite variants formed.

  7. The effects of substituting B for Cu on the magnetic and shape memory properties of CuAlMnB alloys

    Energy Technology Data Exchange (ETDEWEB)

    Aydogdu, Y.; Aydogdu, A. [Gazi University, Department of Physics, Faculty of Science, Ankara (Turkey); Turabi, A.S.; Vance, E.D.; Karaca, H.E. [University of Kentucky, Department of Mechanical Engineering, Lexington, KY (United States); Kok, M. [Firat University, Department of Physics, Faculty of Science, Elazig (Turkey); Kirat, G. [Inonu University, Graduate School of Natural and Applied Sciences, Malatya (Turkey)

    2016-07-15

    The effects of B addition on the magnetization, mechanical and shape memory properties in Cu{sub 70-x}Al{sub 24}Mn{sub 6}B{sub x} at.% (x = 0, 1, 2, 3, 4) alloys have been investigated. The ductility was decreased, while the strength was improved with B addition. Transformation temperatures were increased with B content due to increased e/a ratio. Martensite start temperature of B-free CuAlMn was found to be 37.3 C and increased to 218.8 C with 4 % B addition. B-free CuAlMn exhibited shape memory effect with a recoverable strain of 2.25 % under 200 MPa and a perfect superelasticity with a recoverable strain of 2.5 % at 163 C. B addition degraded the shape memory properties and eventually resulted in the lack of recoverable strain. In addition, saturation magnetization was increased with B content. Moreover, the addition of B slightly decreased the ductility of the alloy. It was found that the magnetization, mechanical and shape memory properties CuAlMn alloys can be tailored by quaternary alloying with B. (orig.)

  8. Rebamipide attenuates nonsteroidal anti-inflammatory drugs (NSAID) induced lipid peroxidation by the manganese superoxide dismutase (MnSOD) overexpression in gastrointestinal epithelial cells.

    Science.gov (United States)

    Nagano, Y; Matsui, H; Shimokawa, O; Hirayama, A; Tamura, M; Nakamura, Y; Kaneko, T; Rai, K; Indo, H P; Majima, H J; Hyodo, I

    2012-04-01

    Nonsteroidal anti-inflammatory drugs (NSAIDs) often cause gastrointestinal complications such as gastric ulcers and erosions. Recent studies on the pathogenesis have revealed that NSAIDs induce lipid peroxidation in gastric epithelial cells by generating superoxide anion in mitochondria, independently with cyclooxygenase-inhibition and the subsequent prostaglandin deficiency. Although not clearly elucidated, the impairment of mitochondrial oxidative phosphorylation, or uncoupling, by NSAIDs is associated with the generation of superoxide anion. Physiologically, superoxide is immediately transformed into hydrogen peroxide and diatomic oxygen with manganese superoxide dismutase (MnSOD). Rebamipide is an antiulcer agent that showed protective effects against NSAID-induced lipid peroxidation in gastrointestinal tracts. We hypothesized that rebamipide may attenuate lipid peroxidation by increasing the expression of MnSOD protein in mitochondria and decreasing the leakage of superoxide anion in NSAID-treated gastric and small intestinal epithelial cells. Firstly, to examine rebamipide increases the expression of MnSOD proteins in mitochondria of gastrointestinal epithelial cells, we underwent Western blotting analysis against anti-MnSOD antibody in gastric RGM1 cells and small intestinal IEC6 cells. Secondly, to examine whether the pretreatment of rebamipide decreases NSAID-induced mitochondrial impairment and lipid peroxidation, we treated these cells with NSAIDs with or without rebamipide pretreatment, and examined with specific fluorescent indicators. Finally, to examine whether pretreatment of rebamipide attenuates NSAID-induced superoxide anion leakage from mitochondria, we examined the mitochondria from indomethacin-treated RGM1 cells with electron spin resonance (ESR) spectroscopy using a specific spin-trapping reagent, CYPMPO. Rebamipide increased the expression of MnSOD protein, and attenuated NSAID-induced mitochondrial impairment and lipid peroxidation in RGM1

  9. 21 CFR 184.1452 - Manganese gluconate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Manganese gluconate. 184.1452 Section 184.1452 Food... Specific Substances Affirmed as GRAS § 184.1452 Manganese gluconate. (a) Manganese gluconate (C12H22MnO14... manganese carbonate with gluconic acid in aqueous medium and then crystallizing the product. (b)...

  10. 21 CFR 184.1461 - Manganese sulfate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Manganese sulfate. 184.1461 Section 184.1461 Food... Specific Substances Affirmed as GRAS § 184.1461 Manganese sulfate. (a) Manganese sulfate (MnSO4·H2O, CAS... manganese compounds with sulfuric acid. It is also obtained as a byproduct in the manufacture...

  11. Microscopy modifications in an aged Cu-Al-Ni-Mn alloy; Modificacoes microestruturais em uma liga Cu-Al-Ni-Mn submetida ao envelhecimento

    Energy Technology Data Exchange (ETDEWEB)

    Gama, J.L.L. [Instituto Federal de Alagoas (IFAL), Maceio, AL (Brazil); Ferreira, R.A.S., E-mail: jorgelauriano@gmail.co [Universidade Federal de Pernambuco (DEM/UFPE), Recife, PE (Brazil). Dept. de Engenharia Mecanica

    2010-07-01

    An Cu-12Al-4Ni-3Mn shape memory alloy have been manufactured using an induction furnace of 24 KVA. After melting, chemical analyse was performed by X-ray fluorescence (XRF). The phase transformation of this alloy was studied in the different sequences produced during thermomechanic treatments. After homogenization, the ingot was solution treated at 850 deg C. At 750 deg C samples were submitted to a reduction by rolling to about 30% in thickness, followed by water quenching. In sequence, the ingot was cold-rolled at different thicknesses. In deformed state, sample of this alloy was submitted to the thermal analyse-DTA for identification of the phase transformation domains. For each identified domain, ageing was carried out, at different times, to evaluate the presence of the different phases. Samples were characterized ray-X diffraction. The results showed that the microstructural evolutions are of a complex nature. At 425 deg C temperature both recrystallization and precipitation of different phases were simultaneously observed. (author)

  12. Studies on Electronic Structure and Magnetic Properties of an Organic Magnet with Metallic Mn2+ and Cu2+ Ions

    Institute of Scientific and Technical Information of China (English)

    YAOJian-Guo; PENGGuang-Xiong

    2004-01-01

    The electronic structure and the magnetic properties of the non-pure organic ferromagnetic compound MnCu(pbaOH)(H2O)3 with pbaOH=2-hydroxy-1, 3-propylenebis (oxamato) are studied by using the density-functional theory with local-spin-density approximation. The density of states, total energy, and the spin magnetic moment are calculated. The calculations reveal that the compound MnCu(pbaOH)(H2O)3 has a stable metal-ferromagnetic ground state, and the spin magnetic moment per molecule is 2.208 μa, and the spin magnetic moment is mainly from Mn ionand Cu ion. An antiferromagnetic order is expected and the antiferromagnetic exchange interaction of d-electrons of Cu and Mn passes through the antiferromagnetic interaction between the adjacent O, 0, and N atoms along the path linking the atoms Cu and Mn.

  13. Manganese Abundances In Three Metal-poor Stars Using Improved log(gf) Data For Mn I And Mn II Lines

    Science.gov (United States)

    Lawler, James E.; Sobeck, J. S.; Den Hartog, E. A.; Sneden, C.; Cowan, J. J.; Truran, J. W.

    2012-01-01

    We present accurate Mn abundances for three very metal-poor stars using new log(gf) measurements [Den Hartog et al. 2011] for transitions of Mn I and Mn II spanning a wavelength range from 2300 to 6050 Å. The three metal-poor ([Fe/H] Hartog, E A, Lawler J E, Sobeck J S, Sneden C, and Cowan J J 2011, ApJS 194, 35

  14. Fe(II)-mediated reduction and repartitioning of structurally incorporated Cu, Co, and Mn in iron oxides.

    Science.gov (United States)

    Frierdich, Andrew J; Catalano, Jeffrey G

    2012-10-16

    The reduction of trace elements and contaminants by Fe(II) at Fe(III) oxide surfaces is well documented. However, the effect of aqueous Fe(II) on the fate of redox-active trace elements structurally incorporated into iron oxides is unknown. Here, we investigate the fate of redox-active elements during Fe(II)-activated recrystallization of Cu-, Co-, and Mn-substituted goethite and hematite. Enhanced release of Cu, Co, and Mn to solution occurs upon exposure of all materials to aqueous Fe(II) relative to reactions in Fe(II)-free fluids. The quantity of trace element release increases with pH when Fe(II) is present but decreases with increasing pH in the absence of Fe(II). Co and Mn release from goethite is predicted well using a second-order kinetic model, consistent with the release of redox-inactive elements such as Ni and Zn. However, Cu release and Co and Mn release from hematite require the sum of two rates to adequately model the kinetic data. Greater uptake of Fe(II) by Cu-, Co-, and Mn-substituted iron oxides relative to analogues containing only redox-inactive elements suggests that net Fe(II) oxidation occurs. Reduction of Cu, Co, and Mn in all materials following reaction with Fe(II) at pHs 7.0-7.5 is confirmed by X-ray absorption near-edge structure spectroscopy. This work shows that redox-sensitive elements structurally incorporated within iron oxides are reduced and repartitioned into fluids during Fe(II)-mediated recrystallization. Such abiotic reactions likely operate in tandem with partial microbial and abiotic iron reduction or during the migration of Fe(II)-containing fluids, mobilizing structurally bound contaminants and micronutrients in aquatic systems.

  15. Biological low pH Mn(II) oxidation in a manganese deposit influenced by metal-rich groundwater

    Science.gov (United States)

    Bohu, Tsing; Akob, Denise M.; Abratis, Michael; Lazar, Cassandre S.; Küsel, Kirsten

    2016-01-01

    The mechanisms, key organisms, and geochemical significance of biological low-pH Mn(II) oxidation are largely unexplored. Here, we investigated the structure of indigenous Mn(II)-oxidizing microbial communities in a secondary subsurface Mn oxide deposit influenced by acidic (pH 4.8) metal-rich groundwater in a former uranium mining area. Microbial diversity was highest in the Mn deposit compared to the adjacent soil layers and included the majority of known Mn(II)-oxidizing bacteria (MOB) and two genera of known Mn(II)-oxidizing fungi (MOF). Electron X-ray microanalysis showed that romanechite [(Ba,H2O)2(Mn4+,Mn3+)5O10] was conspicuously enriched in the deposit. Canonical correspondence analysis revealed that certain fungal, bacterial, and archaeal groups were firmly associated with the autochthonous Mn oxides. Eight MOB within the Proteobacteria, Actinobacteria, and Bacteroidetes and one MOF strain belonging to Ascomycota were isolated at pH 5.5 or 7.2 from the acidic Mn deposit. Soil-groundwater microcosms demonstrated 2.5-fold-faster Mn(II) depletion in the Mn deposit than adjacent soil layers. No depletion was observed in the abiotic controls, suggesting that biological contribution is the main driver for Mn(II) oxidation at low pH. The composition and species specificity of the native low-pH Mn(II) oxidizers were highly adapted to in situ conditions, and these organisms may play a central role in the fundamental biogeochemical processes (e.g., metal natural attenuation) occurring in the acidic, oligotrophic, and metalliferous subsoil ecosystems.

  16. Two New Sandwich-Type Manganese {Mn5}-Substituted Polyoxotungstates: Syntheses, Crystal Structures, Electrochemistry, and Magnetic Properties.

    Science.gov (United States)

    Gupta, Rakesh; Khan, Imran; Hussain, Firasat; Bossoh, A Martin; Mbomekallé, Israël M; de Oliveira, Pedro; Sadakane, Masahiro; Kato, Chisato; Ichihashi, Katsuya; Inoue, Katsuya; Nishihara, Sadafumi

    2017-08-07

    Herein we report two pentanuclear Mn(II)-substituted sandwich-type polyoxotungstate complexes, [{Mn(bpy)}2Na(H2O)2(MnCl)2{Mn(H2O)}(AsW9O33)2](9-) and [{Mn(bpy)}2Na(H2O)2(MnCl){Mn(H2O)}2(SbW9O33)2](8-) (bpy = 2,2'-bipyridine), whose structures have been obtained by single-crystal X-ray diffraction (SCXRD), complemented by results obtained from elemental analysis, electrospray ionization mass spectrometry, Fourier transform infrared spectroscopy, and thermogravimetric analysis. They consist of two [B-α-XW9O33](9-) subunits sandwiching a cyclic assembly of the hexagonal [{Mn(bpy)}2Na(H2O)2(MnCl)2{Mn(H2O)}](9+) and [{Mn(bpy)}2Na(H2O)2(MnCl){Mn(H2O)}2](10+) moieties, respectively, and represent the first pentanuclear Mn(II)-substituted sandwich-type polyoxometalates (POMs). Both compounds have been synthesized by reacting MnCl2·4H2O with trilacunary Na9[XW9O33]·27H2O (X = As(III) and Sb(III)) POM precursors in the presence of bpy in a 1 M aqueous sodium chloride solution under mild reaction conditions. SCXRD showed that the alternate arrangement of three five-coordinated Mn(II) ions and two six-coordinated Mn(II) ions with an internal Na cation formed a coplanar six-membered ring that was sandwiched between two [B-α-XW9O33](9-) (X = As(III) and Sb(III)) subunits. The results of temperature-dependent direct-current (dc) magnetic susceptibility data indicated ferromagnetic interactions between Mn ions in the cluster. Moreover, alternating-current magnetic susceptibility measurements with a dc-biased magnetic field showed the existence of a ferromagnetic order for both samples. Electrochemistry studies revealed the presence of redox processes assigned to the Mn centers. They are associated with the deposition of material on the working electrode surface, possibly MnxOy, as demonstrated by electrochemical quartz crystal microbalance experiments.

  17. Hydrothermal Manganese Mineralization Near the Samoan Hotspot

    Science.gov (United States)

    Hein, J. R.; Staudigel, H.; Koppers, A.; Hart, S. R.; Dunham, R.

    2006-12-01

    The thickest beds of hydrothermal manganese oxides recovered to date from the global ocean were collected from a volcanic cone in the south Pacific. In April 2005, samples were dredged aboard the R.V. Kilo Moana from a volcanic cone on the lower flank of Tulaga seamount (about 2,700 m water depth; 14° 39.222' S; 170° 1.730' W), located 115 km SW of Vailulu'u, the volcanically and hydrothermally active center of the Samoan hotspot. Additional hydrothermal manganese samples were collected off Ofu Island (dredge Alia 107), 72 km to the WSW of Vailulu'u. Manganese-oxide beds up to 9 cm thick are composed of birnessite and 10 Å manganates. Some layers consist of Mn-oxide columnar structures 4 cm long and 1 cm wide, which have not been described previously. The mean Mn and Fe contents of 18 samples are 51 weight percent and 0.76 weight percent, respectively. Elevated concentrations of Li (mean 0.11 wt. percent) are indicators of a hydrothermal origin, and distinguishes these samples, along with the high Mn and low Fe contents, from hydrogenetic Fe-Mn crusts. Other enriched elements include Ba (mean 0.14 percent), Cu (249 ppm), Mo (451 ppm), Ni (400 ppm), Zn (394 ppm), V (214 ppm), and W (132 ppm). Chondrite-normalized REE patterns show large negative Ce anomalies and LREE enrichments, both characteristic of hydrothermal Mn deposits. Small negative Eu anomalies are not typical of hydrothermal deposits and can be explained either by the absence of leaching of plagioclase by the hydrothermal fluids or by the precipitation of Eu-rich minerals, such as barite and anhydrite, at depth. The high base-metal contents indicate that sulfides are not forming deeper in the hydrothermal system or that such deposits are being leached by the ascending fluids. Textures of the thickest Mn deposits indicate that the Mn oxides formed below the seabed from ascending fluids during multiple phases of waxing and waning hydrothermal pulses. The deposits were later exposed at the seafloor by

  18. Aqueous-phase synthesis and color-tuning of core/shell/shell inorganic nanocrystals consisting of ZnSe, (Cu, Mn)-doped ZnS, and ZnS

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jongwan; Yoon, Sujin [Department of Chemistry and Research Institute for Natural Science, Hanyang University, Seoul, 133-791 (Korea, Republic of); Kim, Felix Sunjoo, E-mail: fskim@cau.ac.kr [School of Chemical Engineering and Materials Science, Chung-Ang University, Seoul, 156-756 (Korea, Republic of); Kim, Nakjoong, E-mail: kimnj@hanyang.ac.kr [Department of Chemistry and Research Institute for Natural Science, Hanyang University, Seoul, 133-791 (Korea, Republic of)

    2016-06-25

    We report synthesis of colloidal nanocrystals based on ZnSe core, (Cu,Mn)-doped ZnS inner-shell, and ZnS outer-shell by using an eco-friendly method and their optical properties. Synthesis of core/shell/shell nanocrystals was performed by using a one-pot/three-step colloidal method with 3-mercaptopropionic acid as a stabilizer in aqueous phase at low temperature. A double-shell structure was employed with inner-shell as a host for doping and outer-shell as a passivation layer for covering surface defects. Copper and manganese were introduced as single- or co-dopants during inner-shell formation, providing an effective means to control the emission color of the nanocrystals. The synthesized nanocrystals showed fluorescent emission ranging from blue to green, to white, and to orange, adjusted by doping components, amounts, and ratios. The photoluminescence quantum yields of the core/doped-shell/shell nanocrystals approached 36%. - Highlights: • ZnSe/ZnS:(Cu,Ms)/ZnS core/(doped)shell/shell nanocrystals were synthesized in an aqueous phase. • Emission color of nanocrystals was controlled from blue to white to orange by adjusting the atomic ratio of Cu and Mn co-dopants. • Photoluminescence quantum yields of the colloidal nanocrystals approached 36%.

  19. LiMn{sub 2-x}Cu{sub x}O{sub 4} spinels (0.1 {le} x {le} 0.5) - a new class of 5 V cathode materials for Li batteries : I. electrochemical, structural and spectroscopic studies.

    Energy Technology Data Exchange (ETDEWEB)

    Ein-Eli, Y.

    1998-10-05

    A series of electroactive spinel compounds, LiMn{sub 2{minus}x}Cu{sub x}O{sub 4} (0.1 {le} x {le} 0.5) has been studied by crystallographic, spectroscopic and electrochemical methods and by electron-microscopy. These LiMn{sub 2{minus}x}Cu{sub x}O{sub 4} spinels are nearly identical in structure to cubic LiMn{sub 2}O{sub 4} and successfully undergo reversible Li intercalation. The electrochemical data show a remarkable reversible electrochemical process at 4.9 V which is attributed to the oxidation of Cu{sup 2+} to Cu{sub 3+}. The inclusion of Cu in the spinel structure enhances the electrochemical stability of these materials upon cycling. The initial capacity of LiMn{sub 2{minus}x}Cu{sub x}O{sub 4} spinels decreases with increasing x from 130mAh/g in LiMn{sub 2}O{sub 4} (x=0) to 70 mAh/g in ''LiMn{sub 1.5}Cu{sub 0.5}O{sub 4}'' (x=0.5). The data also show slight shifts to higher voltage for the delithiation reaction that normally occurs at 4.1 V in standard Li{sub 1{minus}x}Mn{sub 2}O{sub 4} electrodes (1 {ge} x {ge} 0) corresponding to the oxidation of Mn{sup 3+} to Mn{sup 4+}. Although the powder X-ray diffraction pattern of ''LiMn{sub 1.5}Cu{sub 0.5}O{sub 4}'' shows a single-phase spinel product, neutron diffraction data show a small, but significant quantity of an impurity phase, the composition and structure of which could not be identified. X-ray absorption spectroscopy was used to gather information about the oxidation states of the manganese and copper ions. The composition of the spinel component in the LiMn{sub 1.5}Cu{sub 0.5}O{sub 4} was determined from X-ray diffraction and XANES data to be Li{sub 1.01}Mn{sub 1.67}Cu{sub 0.32}O{sub 4} suggesting, to a best approximation, that the impurity in the sample was a lithium-copper-oxide phase. The substitution of manganese by copper enhances the reactivity of the spinel structure towards hydrogen; the compounds are more easily reduced at moderate temperature

  20. Effect of Age-Hardening Treatment on Microstructure and Sliding Wear-Resistance Performance of WC/Cu-Ni-Mn Composite Coatings

    Science.gov (United States)

    Liu, Jun; Yang, Shuai; Liu, Kai; Gui, Chibin; Xia, Weisheng

    2017-06-01

    The Cu-Ni-Mn alloy-based hardfacing coatings reinforced by WC particles (WC/Cu-Ni-Mn) were deposited on a steel substrate by a manual oxy-acetylene weld hardfacing method. A sound interfacial junction was formed between the WC particles and the Cu-Ni-Mn alloy metal matrix binder even after the age-hardening treatment. The friction and wear behavior of the hardfacing coatings was investigated. With the introduction of WC particles, the sliding wear resistance of the WC/Cu-Ni-Mn hardfacing coatings was sharply improved: more than 200 times better than that of the age-hardening-treated Cu-Ni-Mn alloy coating. The sliding wear resistances of the as-deposited and the age-hardening-treated WC/Cu-Ni-Mn hardfacing coatings were 1.83 and 2.26 times higher than that of the commercial Fe-Cr-C hardfacing coating, which is mainly ascribed to the higher volume fraction of carbide reinforcement. Owing to the precipitation of the NiMn secondary phase in the Cu-Ni-Mn metal matrix, the age-hardening-treated coating had better wear resistance than that of the as-deposited coating. The main sliding wear mechanisms of the age-hardening-treated coatings are adhesion and abrasion.

  1. Cu(II) and Zn(II) ions alter the dynamics and distribution of Mn(II) in cultured chick glial cells

    Energy Technology Data Exchange (ETDEWEB)

    Wedler, F.C.; Ley, B.W. (Dept. of Molecular Cell Biology, Pennsylvania State University, University Park (USA))

    1990-12-01

    Previous studies revealed that Mn(II) is accumulated in cultured glial cells to concentrations far above those present in whole brain or in culture medium. The data indicated that Mn(II) moves across the plasma membrane into the cytoplasm by facilitated diffusion or counter-ion transport with Ca(II), then into mitochondria by active transport. The fact that 1-10 microM Mn(II) ions activate brain glutamine synthetase makes important the regulation of Mn(II) transport in the CNS. Since Cu(II) and Zn(II) caused significant changes in the accumulation of Mn(II) by glia, the mechanisms by which these ions alter the uptake and efflux of Mn(II) ions has been investigated systematically under chemically defined conditions. The kinetics of (54MN)-Mn(II) uptake and efflux were determined and compared under four different sets of conditions: no adducts, Cu(II) or Zn(II) added externally, and with cells preloaded with Cu(II) or Zn(II) in the presence and absence of external added metal ions. Zn(II) ions inhibit the initial velocity of Mn(II) uptake, increase total Mn(II) accumulated, but do not alter the rate or extent Mn(II) efflux. Cu(II) ions increase both the initial velocity and the net Mn(II) accumulated by glia, with little effect on rate or extent of Mn(II) efflux. These results predict that increases in Cu(II) or Zn(II) levels may also increase the steady-state levels of Mn(II) in the cytoplasmic fraction of glial cells, which may in turn alter the activity of Mn(II)-sensitive enzymes in this cell compartment.

  2. Modulation of in utero total body irradiation induced newborn mouse growth retardation by maternal manganese superoxide dismutase-plasmid liposome (MnSOD-PL) gene therapy.

    Science.gov (United States)

    Epperly, M W; Smith, T; Zhang, X; Goff, J P; Franicola, D; Greenberger, B; Komanduri, P; Wang, H; Greenberger, J S

    2011-06-01

    To determine the effects of manganese superoxide dismutase (MnSOD) plasmid liposome (PL) maternal radioprotection on fetal mice, timed pregnant female mice (E14 gestation) were irradiated to 3.0 Gy total body irradiation (TBI) dose, and the number, weight and growth and development over 6 months after birth of newborn mice was quantitated compared with irradiated controls. Maternal MnSOD-PL treatment at E13 improved pup survival at birth (5.4±0.9 per litter) compared with non-irradiated 3.0 Gy controls 4.9±1.1. There was no statistically significant difference in newborn abnormalities, male to female ratio in newborn litters, or other evidence of teratogenesis in surviving newborn mice from MnSOD-PL treated compared with irradiated controls. However, E14 3 Gy irradiated pups from gene therapy-treated mothers showed a significant increase in both growth and overall survival over 6 months after birth (P=0.0022). To determine if transgene product crossed the placenta pregnant E13 mice were injected intravenously with hemagglutinin-epitope-tagged MnSOD (100 μg plasmid in 100 μl liposomes), then after 24 h, fetal mice, placentas and maternal tissues were removed and tested by both immunohistochemistry and reverse transcriptase-PCR for transgene and product. There was no evidence of transgene or product in placenta or any fetal tissue while maternal liver was positive by both assays. The data provide evidence for fetal radioprotection by maternal MnSOD-PL gene therapy before irradiation, which is mediated by an indirect bystander effect and is associated with a significant improvement in both survival at birth and growth and development of newborn mice.

  3. Effect of alloying elements on branching of primary austenite dendrites in Ni-Mn-Cu cast iron

    Directory of Open Access Journals (Sweden)

    A. Janus

    2011-04-01

    Full Text Available Within the research, determined were direction and intensity of influence of individual alloying elements on branching degree of primary austenite dendrites in austenitic cast iron Ni-Mn-Cu. 30 cast shafts dia. 20 mm were analysed. Chemical composition of the alloywas as follows: 2.0 to 3.3 % C, 1.4 to 3.1 % Si, 2.8 to 9.5 % Ni, 0.4 to 7.7 % Mn, 0 to 4.6 % Cu, 0.14 to 0.16 % P and 0.03 to 0.04 % S.Analysis was performed separately for the dendrites solidifying in directional and volumetric way. The average distance "x" between the2nd order arms was accepted as the criterion of branching degree. It was found that influence of C, Si, Ni, Mn and Cu on the parameter "x"is statistically significant. Intensity of carbon influence is decidedly higher than that of other elements, and the influence is more intensive in the directionally solidifying dendrites. However, in the case of the alloyed cast iron Ni-Mn-Cu, combined influence of the alloying elements on solidification course of primary austenite can be significant.

  4. 热轧高锰钢Mn13的冲滚磨料磨损性能∗%Impact and Rolling Abrasive Wear Properties of Hot Rolling Mn13 High Manganese Steel

    Institute of Scientific and Technical Information of China (English)

    赵欣; 张恒; 王斐; 王庆良

    2015-01-01

    The impact⁃rolling abrasive wear properties of hot rolling high manganese steel of Mn13 were studied under the condition of coal gangue abrasive by the experimental machine of M2000. XRD and SEM were used to investigate the structural transformation and wear mechanism of Mn13 steel. The results show that the hot rolled steel Mn13 reveals the better resistance to impact⁃rolling abrasive wear properties under the high impact loads. The hardened layer with a certain thickness is formed in worn surface.The hardness and thickness of hardened layer are improved with the increasing of im⁃pact loads.The deformation twinning and martensite phase transformation are the main reasons to improve the work harden⁃ing and wear resistance of hot rolling high manganese steel of Mn13.At the low impact loads,the drilling and plowing wear are the main wear mechanism,and at the high impact loads,the wear mechanism changes to fatigue fracture and drilling wear.%在M2000摩擦磨损试验机上,研究以煤矸石为磨料时热轧高锰钢Mn13冲滚耦合的磨料磨损性能,利用XRD和SEM分析其组织转变及磨损机制。实验结果表明,在较高冲滚载荷下,热轧Mn13钢表现出更好的抗冲滚磨料磨损性能;冲滚磨料磨损表面存在一定厚度的硬化层,且随冲滚载荷的增加,磨损面硬度增加,硬化层厚度增大,形变孪晶和马氏体相变是其加工硬化和耐磨损性能改善的主要原因;低载荷冲击时,磨损机制主要表现为凿削磨损并伴随犁沟切削磨损,较高载荷冲击时,磨损机制凿削磨损和犁沟划伤过渡到疲劳剥落和凿削磨损。

  5. Manganese dipyridoxyl diphosphate:

    DEFF Research Database (Denmark)

    H, Brurok; Ardenkjær-Larsen, Jan Henrik; G, Hansson

    1999-01-01

    Manganese dipyridoxyl diphosphate (MnDPDP) is a contrast agent for magnetic resonance imaging (MRI) of the liver. Aims of the study were to examine if MnDPDP possesses superoxide dismutase (SOD) mimetic activity in vitro, and if antioxidant protection can be demonstrated in an ex vivo rat heart...

  6. Manganese deficiency in plants

    DEFF Research Database (Denmark)

    Schmidt, Sidsel Birkelund; Jensen, Poul Erik; Husted, Søren

    2016-01-01

    Manganese (Mn) is an essential plant micronutrient with an indispensable function as a catalyst in the oxygen-evolving complex (OEC) of photosystem II (PSII). Even so, Mn deficiency frequently occurs without visual leaf symptoms, thereby masking the distribution and dimension of the problem...

  7. Biological Superoxide In Manganese Oxide Formation

    Science.gov (United States)

    Hansel, C.; Learman, D.; Zeiner, C.; Santelli, C. M.

    2011-12-01

    Manganese (Mn) oxides are among the strongest sorbents and oxidants within the environment, controlling the fate and transport of numerous elements and the degradation of recalcitrant carbon. Both bacteria and fungi mediate the oxidation of Mn(II) to Mn(III/IV) oxides but the genetic and biochemical mechanisms responsible remain poorly understood. Furthermore, the physiological basis for microbial Mn(II) oxidation remains an enigma. We have recently reported that a common marine bacterium (Roseobacter sp. AzwK-3b) oxidizes Mn(II) via reaction with extracellular superoxide (O2-) produced during exponential growth. Here we expand this superoxide-mediated Mn(II) oxidation pathway to fungi, introducing a surprising homology between prokaryotic and eukaryotic metal redox processes. For instance, Stibella aciculosa, a common soil Ascomycete filamentous fungus, precipitates Mn oxides at the base of asexual reproductive structures (synnemata) used to support conidia (Figure 1). This distribution is a consequence of localized production of superoxide (and it's dismutation product hydrogen peroxide, H2O2), leading to abiotic oxidation of Mn(II) by superoxide. Disruption of NADPH oxidase activity using the oxidoreductase inhibitor DPI leads to diminished cell differentiation and subsequent Mn(II) oxidation inhibition. Addition of Cu(II) (an effective superoxide scavenger) leads to a concentration dependent decrease in Mn oxide formation. We predict that due to the widespread production of extracellular superoxide within the fungal and likely bacterial kingdoms, biological superoxide may be an important contributor to the cycling of Mn, as well as other metals (e.g., Hg, Fe). Current and future explorations of the genes and proteins involved in superoxide production and Mn(II) oxidation will ideally lend insight into the physiological and biochemical basis for these processes.

  8. An experimental investigation of innovative bridge columns with engineered cementitious composites and Cu-Al-Mn super-elastic alloys

    Science.gov (United States)

    Hosseini, F.; Gencturk, B.; Lahpour, S.; Ibague Gil, D.

    2015-08-01

    Recent strong earthquakes have shown that reinforced concrete (RC) bridge columns constructed using conventional materials and techniques suffer from major damage and permanent deformations. The yielding of the longitudinal reinforcement as the main source of energy absorption, and cracking and spalling of concrete results in a dysfunctional bridge structure that does not support the post-disaster recovery efforts. This paper investigates the use of engineered cementitious composites (ECCs) and Cu-Al-Mn super-elastic alloys (SEAs) to improve the performance of bridge columns under seismic loads. A new column design is proposed, which is composed of a pre-fabricated ECC tube that encompasses the longitudinal and transverse steel reinforcement (rebar). The rebar in the plastic hinge region of the cantilever columns was totally or partially replaced with Cu-Al-Mn SEA bars. The tube was filled with conventional concrete after it was placed inside the rebar cage of the foundation. ECC exhibits superior tensile ductility, bonding with steel, energy absorption and shear resistance, in addition to lower permeability and reduced crack widths compared to conventional concrete. Cu-Al-Mn SEA bars are capable of recovering large inelastic deformations exceeding 12% strain. The proposed approach capitalizes on the deformability of ECC with reduced damage, and the energy absorption capacity of Cu-Al-Mn SEA bars without permanent deformation. A total of six column specimens were constructed and tested under simulated seismic loading. The number of rebars replaced with Cu-Al-Mn SEA bars, ECC mixture design, and the ratio of the concrete core area to total column cross-sectional area were the variables investigated in the test program. A comparison of the results indicated that the proposed concept with no Cu-Al-Mn SEA bars provides higher lateral strength, similar energy absorption and reduced damage compared to conventional RC columns; however, similar to a conventional column, it

  9. Noncollinear antiferromagnetism of coupled spins and pseudospins in the double perovskite La<mn>2mn>CuIrO>6mn>

    Energy Technology Data Exchange (ETDEWEB)

    Manna, Kaustuv [Leibniz Inst. for Solid State and Materials Research (IFW), Dresden (Germany); Sarkar, R. [Technische Univ. Dresden (Germany); Fuchs, S. [Leibniz Inst. for Solid State and Materials Research (IFW), Dresden (Germany); Onykiienko, Y. A. [Technische Univ. Dresden (Germany); Bera, A. K. [Bhabha Atomic Research Centre (BARC), Mumbai (India); Cansever, G. Aslan [Leibniz Inst. for Solid State and Materials Research (IFW), Dresden (Germany); Kamusella, S. [Technische Univ. Dresden (Germany); Maljuk, A. [Leibniz Inst. for Solid State and Materials Research (IFW), Dresden (Germany); Blum, C. G. F. [Leibniz Inst. for Solid State and Materials Research (IFW), Dresden (Germany); Corredor, L. T. [Leibniz Inst. for Solid State and Materials Research (IFW), Dresden (Germany); Wolter, A. U. B. [Leibniz Inst. for Solid State and Materials Research (IFW), Dresden (Germany); Yusuf, S. M. [Bhabha Atomic Research Centre (BARC), Mumbai (India); Frontzek, M. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Keller, L. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Iakovleva, M. [Leibniz Inst. for Solid State and Materials Research (IFW), Dresden (Germany); Russian Academy of Sciences (RAS), Kazan (Russian Federation); Vavilova, E. [Russian Academy of Sciences (RAS), Kazan (Russian Federation); Grafe, H. -J. [Leibniz Inst. for Solid State and Materials Research (IFW), Dresden (Germany); Kataev, V. [Leibniz Inst. for Solid State and Materials Research (IFW), Dresden (Germany); Klauss, H. -H. [Technische Univ. Dresden (Germany); Inosov, D. S. [Technische Univ. Dresden (Germany); Wurmehl, S. [Leibniz Inst. for Solid State and Materials Research (IFW), Dresden (Germany); Technische Univ. Dresden (Germany); Büchner, B. [Leibniz Inst. for Solid State and Materials Research (IFW), Dresden (Germany); Technische Univ. Dresden (Germany)

    2016-10-01

    This article reports the structural, magnetic, and thermodynamic properties of the double perovskite compound La<mn>2mn>CuIrO>6mn> from x-ray, neutron diffraction, neutron depolarization, dc magnetization, ac susceptibility, specific heat, muon-spin-relaxation ( μ SR ) , electron-spin-resonance (ESR) and nuclear magnetic resonance (NMR) measurements. Below ~113 K, short-range spin-spin correlations occur within the Cu2+ sublattice.

  10. Thermal Stability of CoFe/Cu/CoFe/IrMn Top Spin Valve

    Institute of Scientific and Technical Information of China (English)

    ZHOU Guang-Hong; WANG Yin-Gang; QI Xian-Jin

    2009-01-01

    We present a study of thermal stability of the top spin valve with a structure of seed Ta (5nm)/Co75Fe25 (5nm)/Cu (2.5nm)/Co75Fe25n (5nm)/Ir20 Mn80 (12nm)/cap Ta (8nm) deposited at room temperature by magnetron sputtering. A vibrating sample magnetometer fixed with a heater was used to record the magnetic hysteresis loops at variational temperatures and x-ray diffraction was performed to characterize the structure of the multilayer.The exchange field Hex and the coercivity of the pinned CoFe layer Hcp decrease monotonically with increasing temperature.The coercivity of the free CoFe layer Hcf in the spin valve shows a maximum at 498K.The temperature dependences of Hex,Hcp and Hcf have also been discussed.

  11. TEM observation of oxidation of CuZnAlMnNi shape memory alloy

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The atmospheric oxidation of a quenched CuZnAlMnNi alloy after ion-polishing was examined by transmission electron microscopy (TEM). It was found that a lot of oxide grains with various sizes yield homogeneously on the surface of the alloy after exposure at room temperature for 90 d. The grains mainly form along the planes of stacking fault, meanwhile, they can also be observed at the stacking fault tetrahedrals or around the dislocation lines. The formarion of the oxides gives rise to the reduction of the stacking faults, and even complete disappearance in some zones,which is partly responsible for the decrement of shape memory. effect (SME) of the alloy quenched during long-term holding at room temperature.

  12. Effect of Cu and Mn on the Mechanical Properties and Microstructure of Ductile Cast Iron

    Directory of Open Access Journals (Sweden)

    A.M.Omran

    2014-06-01

    Full Text Available This paper described the method used for producing ductile cast iron (SGI. The processing parameters affecting the production of SGI were studied. These parameters include chemical composition, castings thickness, mechanical properties, alloying elements and microstructure. The chemical composition of producing SGI was optimized. The nodularity was increased with increasing the percentages of Mg content and with decreasing the castings thickness. The amount of pearlite and mechanical properties were increased sharply with increasing Cu and Mn contents in the produced SGI. Empirical equations were correlated to indicate the relations among nodularity, Mg content and other parameters. The results shown also as the post inoculation increased the metallurgical quality was improved. The suitability of SGI as automotive engine was tested and different empirical correlations were obtained

  13. Effect of Chemical Composition on Structure and Corrosion Resistance of Ni-Mn-Cu Cast Iron

    Directory of Open Access Journals (Sweden)

    Medyński D.

    2016-09-01

    Full Text Available In the paper, a relationship between chemical composition of Ni-Mn-Cu cast iron and its structure, hardness and corrosion resistance is determined. The examinations showed a decrease of thermodynamic stability of austenite together with decreasing nickel equivalent value, in cast iron solidifying according to both the stable and the metastable systems. As a result of increasing degree of austenite transformation, the created martensite caused a significant hardness increase, accompanied by small decline of corrosion resistance. It was found at the same time that solidification way of the alloy and its matrix structure affect corrosion resistance to a much smaller extent than the nickel equivalent value, in particular concentration of elements with high electrochemical potential.

  14. Characteristics of flake graphite in Ni-Mn-Cu cast iron. Part 1

    Directory of Open Access Journals (Sweden)

    A. Janus

    2009-01-01

    Full Text Available Relationship between chemical composition of cast iron and properties of flake graphite occurring in hypoeutectic and eutectic nickelmanganese-copper cast iron was determined. The research covered over 60 alloys of cast iron containing 1.6 to 4.1 % C, 1.3 to 2.8 % Si,2.4 to 10.5 % Ni, 0.2 to 8.2 % Mn, 0.1 to 3.5 % Cu, 0.14 to 0.17 % P and 0.02 to 0.04 % S. Evolution of graphite properties with changingeutecticity degree of the examined cast iron is presented. For selected castings, histograms of eutectic graphite colonies are presented, showing numbers of graphite precipitates in individual size ranges and their shape described by the coefficient

  15. The content of Ca, Cu, Fe, Mg and Mn and antioxidant activity of green coffee brews.

    Science.gov (United States)

    Stelmach, Ewelina; Pohl, Pawel; Szymczycha-Madeja, Anna

    2015-09-01

    A simple and fast method of the analysis of green coffee infusions was developed to measure total concentrations of Ca, Cu, Fe, Mg and Mn by high resolution-continuum source flame atomic absorption spectrometry. The precision of the method was within 1-8%, while the accuracy was within -1% to 2%. The method was used to the analysis of infusions of twelve green coffees of different geographical origin. It was found that Ca and Mg were leached the easiest, i.e., on average 75% and 70%, respectively. As compared to the mug coffee preparation, the rate of the extraction of elements was increased when infusions were prepared using dripper or Turkish coffee preparation methods. Additionally, it was established that the antioxidant activity of green coffee infusions prepared using the mug coffee preparation was high, 75% on average, and positively correlated with the total content of phenolic compounds and the concentration of Ca in the brew.

  16. Biodegradation of Chlorpyrifos by Manganese Peroxidase%锰过氧化物酶(MnP)对农药毒死蜱降解的初步研究

    Institute of Scientific and Technical Information of China (English)

    莫彩萍; 赵林果; 谢慧芳

    2012-01-01

    Biodegradation of chlorpyrifos by manganese peroxidase (MnP) which was prepared using whit rot fungi P. sordida YK-624 was studied. The systems of chlorpytifos biodegradation were tested. Results showed that the chlorpyrifos biodegradation by MnP should be done in organic acid buffer solution (malonic acid)containing Mn2+ and H2O2 which was produced by glucose oxidase oxidizing glucose. But surfactant Tween 80 was not necessary because of poor solubility of chlorpyrifos. Main influencing factors were determined. It proved that chlorpyrifos could be biodegraded by MnP at 30 ℃ in pH 4.5 malonic acid buffer system, which contained 7.5 mmmol/L MnSO4,2.5 mmol/L glucose and 40 U glucose oxidase. Under the conditions, 400 U/L MnP could degrade 77.51% 30 mg/L chlorpyrifos. GC-MS was used to analyze the product of chlorpyrifos biodegradation by MnP. It was found the possible enzymolysis product was O, O, O', O'-tetraethyl-dithiopyrophosphate, different from hydrolysis or bacterium degradation production of chlorpyrifos.%以广泛使用的有机磷杀虫剂毒死蜱为研究对象,利用白腐菌P.sordida YK-624.菌株所产锰过氧化物酶(MnP)对其进行生物降解的初步研究.首先比较确定了MnP降解毒死蜱所需要的降解体系,即对于毒死蜱的降解,需要在有机酸(丙二酸)存在的缓冲体系中进行,此体系不需要表面活性剂Tween 80,但必须含有Mn2+和葡萄糖氧化酶氧化葡萄糖产生的H2O2.随后对主要影响因素的试验结果表明,MnP降解毒死蜱较好的条件是在pH 4.5的丙二酸缓冲体系中含7.5 mmol/L MnSO4、2.5 mmol/L葡萄糖以及40 U葡萄糖氧化酶,温度30℃.此时,400 U/L的MnP可将30 mg/L的毒死蜱经3d时间降解77.51%.同时,利用GC-MS对毒死蜱酶降解后的产物进行了初步分析,得到1种可能的酶解产物O,O,O’,O’-四乙基二硫代焦磷酸酯,不同于水解和细菌降解途径,值得进行进一步研究.

  17. Selective nonenzymatic bilirubin detection in blood samples using a Nafion/Mn-Cu sensor.

    Science.gov (United States)

    Noh, Hui-Bog; Won, Mi-Sook; Shim, Yoon-Bo

    2014-11-15

    The specific detection of biological organics without the use of an enzyme is challenging, and it is crucial for analytical and clinical chemistry. We report specific nonenzymatic bilirubin detection through the catalytic oxidation of bilirubin molecule on the Nafion/Mn-Cu surface. The catalytic ability, true surface area, morphology, crystallinity, composition, and oxidation state of the sensor surface were assessed using voltammetry, coulometry, XPS, XRD, Brunauer-Emmett-Teller (BET), SEM, EDXS, and TOF-SIMS experiments. The results showed that the surface was composed of microporous Mn-Cu bimetallic crystal in flake shape with a large BET surface area (3.635 m(2)g(-1)), where the surface area and crystallinity mainly affected the sensor performance. Product analysis of the catalytic reaction on the sensor probe revealed a specific two-electron oxidation of dipyrromethane moiety to dipyrromethene in the bilirubin molecule. Experimental variables affecting the analysis of bilirubin were optimized in terms of probe composition, temperature, pH, and potential. At the optimized condition, the dynamic range was between 1.2 μM and 0.42 mM, which yielded the equation of ΔI (μA)=(1.03 ± 0.72)+(457.0 ± 4.03) [C] (mM) with 0.999 of correlation coefficient, and the detection limit was 25.0 ± 1.8 nM (n=5, k=3). The stability test, interference effects, and analysis of real clinical samples, human whole blood and certified serum samples were demonstrated to confirm the reliability of the proposed bilirubin sensor.

  18. Mn valence state and electrode performance of perovskite-type cathode La0.8Sr0.2Mn1−CuO3− ( = 0, 0.2) for intermediate-temperature solid oxide fuel cells

    Indian Academy of Sciences (India)

    Taimin Noh; Jinseong Kim; Yongtae Kim; Ho Hwan Chun; Min-Seok Jeon; Heesoo Lee

    2013-12-01

    Cu-free and Cu-doped LSM system, La0.8Sr0.2Mn1−CuO3− ( = 0, 0.2), with perovskite structure were prepared using an EDTA combined citrate process and the effects of Cu ion at B-site were investigated. Electrical conductivity and polarization resistance of the Cu-doped LSM were 210 S.cm-1 at 750 °C, and 2.54 . cm2 at 800 °C, respectively which were better than those of the Cu-free LSM. This indicated that the electrode performance of LSM was improved by the addition of Cu. The oxidation state of Mn ions increased with addition of Cu. The increase in the oxidation state of Mn ions was due to the formation of Mn4+ ions and oxygen vacancies. The addition of Cu ions to LSM systems could lead to enhanced electrode performance for oxygen reduction reactions originating from the change in valence of Mn ions.

  19. Effect of Heat-treatment Parameters of Cast Iron GJS-X350NiMnCu7-3-2 on its Structure and Mechanical Properties

    Directory of Open Access Journals (Sweden)

    Medyński D.

    2017-03-01

    Full Text Available The paper presents influence of soaking parameters (temperature and time on structure and mechanical properties of spheroidal graphite nickel-manganese-copper cast iron, containing: 7.2% Ni, 2.6% Mn and 2.4% Cu. Raw castings showed austenitic structure and relatively low hardness (150 HBW guaranteeing their good machinability. Heat treatment consisted in soaking the castings within 400 to 600°C for 2 to 10 hours followed by air-cooling. In most cases, soaking caused changes in structure and, in consequence, an increase of hardness in comparison to raw castings. The highest hardness and tensile strength was obtained after soaking at 550°C for 6 hours. At the same time, decrease of the parameters related to plasticity of cast iron (elongation and impact strength was observed. This resulted from the fact that, in these conditions, the largest fraction of fine-acicular ferrite with relatively high hardness (490 HV0.1 was created in the matrix. At lower temperatures and after shorter soaking times, hardness and tensile strength were lower because of smaller degree of austenite transformation. At higher temperatures and after longer soaking times, fine-dispersive ferrite was produced. That resulted in slightly lower material hardness.

  20. The structure of the Caenorhabditis elegans manganese superoxide dismutase MnSOD‐3‐azide complex

    National Research Council Canada - National Science Library

    Hunter, Gary J; Trinh, Chi H; Bonetta, Rosalin; Stewart, Emma E; Cabelli, Diane E; Hunter, Therese

    2015-01-01

    ...‐on to the manganese center as a sixth ligand and that it ligates directly to a third and new solvent molecule also positioned within interacting distance to the His30 and Tyr34 residues of the substrate access funnel...

  1. Relationship between mRNA expression of MnSOD and manganese neurotoxicity%锰超氧化物歧化酶基因表达水平与锰神经毒性的关系

    Institute of Scientific and Technical Information of China (English)

    范晓丽; 闫永建; 蔡绍雷; 何跃玲; 张明钢

    2013-01-01

    目的 探讨锰超氧化物歧化酶(MnSOD)基因表达水平与锰神经毒性的关系.方法 筛选31例职业性慢性锰中毒病例及31例同等暴露条件的对照组,提取全血RNA,采用反转录-聚合酶链反应(RT-PCR)法检测MnSOD基因mRNA表达水平,分析病例组与对照组间的差异;以PC12细胞为模型,给予0、100、200、400、600、800、1000 μmol/L浓度的MnCl2分别作用1、2、3、4d,噻唑蓝(MTT)法检测细胞抑制率,RT-PCR方法检测MnSOD mRNA表达水平.结果 病例组与对照组MnSOD基因表达水平分别为0.390±0.080和0.582±0.219,病例组较对照组降低,差异有统计学意义(P<0.05);MnC12对PC12细胞具有毒性作用,浓度越高,毒性作用越强,MnSOD mRNA的表达越少.结论 MnSOD基因可能参与了锰致神经细胞损伤的过程,推测其高表达可能对锰的神经毒性起到抑制作用.%Objective To investigate the relationship between mRNA expression of manganese superoxide dismutase (MnSOD) and manganese neurotoxicity.Methods Thirty-one patients with occupational chronic manganese poisoning (case group),as well as 31 controls exposed to the same condition (control group),were included in the study.Whole blood RNA was extracted,and the mRNA expression of MnSOD was measured by RT-PCR; the two groups were compared in terms of the mRNA expression of MnSOD.PC12 cells were treated with 0,100,200,400,600,800,and 1000 μmol/L MnC12 for 1,2,3,and 4 d; the cell viability was determined by MTT assay,and the mRNA expression of MnSOD was measured by RT-PCR.Results The case group had significantly lower mRNA expression of MnSOD than the control group (0.390±0.080 vs 0.582±0.219,P<0.05).MnC12 had a toxic effect on PC 12 cells; the concentration of MnC12 was positively correlated with the toxic effect but negatively correlated with the mRNA expression of MnSOD.Conclusion MnSOD mRNA may be involved in the manganese-induced damage of nerve cells.It is hypothesized that high mRNA expression

  2. Manganese-mediated ferromagnetism in La2Fe1-Mn2Cr1-O6 perovskite oxides

    Indian Academy of Sciences (India)

    R M Tiwari; Mrudul Gadhvi; Abanti Nag; N Y Vasanthacharya; J Gopalakrishnan

    2010-07-01

    We have investigated the structure and magnetic properties of the perovskite oxides of the formula La2Fe1-Mn2Cr1-O6 (0 < < 1.0). For 0 < ≤ 0.5, the members adopt the orthorhombic (Pbnm) structure, where the transition metal atoms are disordered at the 4b sites and the MO6 (M = Fe, Mn, Cr) octahedra become increasingly distorted with increasing . For 0.65 ≤ < 1.0, the members adopt the rhombohedral (R-3c) structure that is similar to LaMnO3+ ( ≥ 0.1) where the MO6 octahedra are undistorted. While the magnetic properties of the latter series are largely similar to the parent LaMnO3+ arising from the double-exchange (DE) between mixed valent MnIII/MnIV, the magnetic properties of the orthorhombic members show a distinct (albeit weak) ferromagnetism (C ∼ 200 K) that seems to arise from a MnIII-mediated superexchange (SE) between FeIII/CrIII in the disordered perovskite structure containing FeIII, MnIII and CrIII.

  3. Selective adsorption of manganese onto cobalt for optimized Mn/Co/TiO2 Fischer-Tropsch catalysts

    NARCIS (Netherlands)

    Feltes, T.E.; Espinosa-Alonso, L.; de Smit, E.; D'Souza, L.; Meyer, R.J.; Weckhuysen, B.M.; Regalbuto, J.R.

    2013-01-01

    The Strong Electrostatic Adsorption (SEA) method was applied to the rational design of a promoted Co catalyst for Fischer–Tropsch (FT) synthesis. A series of Mn/Co/TiO2 catalysts were prepared by selective deposition of the [MnO4] anion onto the supported Co3O4 phase. Qualitative ICP-OES and XPS mea

  4. Synthesis, identification and thermal decomposition of double sulfites like Cu2SO3·MSO3·2H2O (M=Cu, Fe, Mn or Cd)

    OpenAIRE

    2000-01-01

    Texto completo: acesso restrito. p.17–27 Double sulfites with empirical formula Cu2SO3·MSO3·2H2O (where M is Cu, Fe, Mn, or Cd) were obtained by saturation with sulfur dioxide gas of an aqueous mixture of MII sulfate and copper sulfate at room temperature. The salts obtained were identified by infrared spectra, X-ray powder diffraction and elemental analysis. The compounds studied are isostructural with the CuII replacement by MnII, FeII, and CdII in Chevreul’s salt (Cu2SO3·CuSO3·2H2O). Th...

  5. Effects of Mn and Cu on the Mechanical Properties of a High Strength Low Alloy NiCrMoV Steel

    Institute of Scientific and Technical Information of China (English)

    A.Abdollah-zadeh; M. Belbasy

    2005-01-01

    The present study focuses on the effects of Mn and Cu on the mechanical properties, in particular, strength and toughness of a low alloy steel containing Ni, Cr, Mo and V. Specimens with different amounts of Mn (0.23%~0.85%)and Cu (0.15%~0.45%) were cast and forged, and then austenitized at 870℃ for 1 h, followed by oil quenching. All specimens were tempered at 650℃ for 1 h. The results show that as the amounts of Mn and Cu increase respectively from 0.35% to 0.85% and from 0.15% to 0.45%, the yield and tensile strength increase. The highest impact energies were observed in the specimen with 0.35% Mn and in the specimen with 0.25% Cu. The impact energy decreases with increasing the Mn and Cu from 0.35% to 0.85% and from 0.25% to 0.45%, respectively. Furthermore, the variation of Mn and Cu does not cause a considerable change in the tempered martensite microstructure. The optimum strength and toughness is observed in 0.35% Mn containing steel and in the 0.25% Cu containing steel.

  6. Mn-Cu-Ce-Fe/REY系列催化剂上NH3选择性催化还原NO性能%Selective catalytic reduction of NO with NH3 over Mn-Cu-Ce-Fe/REY catalysts

    Institute of Scientific and Technical Information of China (English)

    任翠涛; 李滨; 王虹; 李翠清; 丁福臣; 宋永吉

    2012-01-01

    Mn-Cu-Fe-Ce/REY catalysts were designed with orthogonal experimental method and prepared by impregnation method. The catalytic performance of the catalysts for selective reduction of NO with NH3 was evaluated in the presence of S02 and in a fixed bed micro-reactor. The effects of Mn, Cu, Fe and Ce components on the catalytic activity were investigated. The catalysts were characterized by XRD, SEM and H2 -TPR. The results showed that the sequence of the influence of active components on catalyst activity from big to small was as follows; Cu > Fe > Ce > Mn, and the activity of the catalysts was affected by their redox properties.%采用正交实验设计和浸渍法制备Mn-Cu-Fe-Ce/REY催化剂.采用固定床微型反应器评价SO2存在下催化剂在NH3选择性催化还原NO反应中的活性,考察Mn、Cu、Fe和Ce各活性组分对催化剂活性的影响,并采用XRD、H2-TPR和SEM等手段对催化剂进行表征.结果表明,Mn、Cu、Fe和Ce各活性组分对催化剂活性影响顺序为:Cu> Fe> Ce> Mn,催化剂的氧化还原性能影响催化剂活性.

  7. Physicochemical, Surface, and Catalytic Properties of Pure and Ceria-Doped Manganese/Alumina Catalysts%CeO2掺杂的Mn/Al催化剂的物化、表面及催化性能

    Institute of Scientific and Technical Information of China (English)

    Nasr-Allah M. DERAZ

    2008-01-01

    Pure and CeO2-doped Mn/Al mixed oxides were prepared by the wet impregnation method using finely powdered alumina, manganese, and cerium nitrates. The physicochemical, surface, and catalytic properties of the thermally treated solids (at 500, 800, and 900 ℃) were investigated using XRD, nitrogen adsorption at -196 ℃, and hydrogen peroxide decomposition in an aqueous solution at 30 - 50 ℃. The Mn oxidation state changed from Mn4+ to Mn2+ on increasing the calcination temperature. There were two unique features associated with CeO2 that are of interest. The first was that it favored the dispersion of manganese oxides deposited on the γ-Al2O3 catalyst calcined at 500 ℃. The second was that it enhanced the formation of Mn3O4 species from Mn2O3 deposited initially on the alumina support calcined at 800 and 900 ℃. Consequently, the specific surface area of the Mn/Al mixed oxides calcined at 500 ℃ was increased by increasing the amount of dopant added. An opposite effect was observed by increasing the calcination temperature from 500 to 900 ℃. The doping followed by calcination at different temperatures brought about an increase in the catalytic activity of mixed oxides. Pretreatments did not modify the mechanism of the catalyzed reaction but changed the number of catalytically active sites without changing the nature of these sites.

  8. CuMnNiSi钎料钎焊不锈钢接头组织性能研究%Structure and Property of Stainless Steel Brazed Joint with CuMnNiSi Filler Metal

    Institute of Scientific and Technical Information of China (English)

    杨光; 李宁; 颜家振; 苑博

    2011-01-01

    采用新型的Cu-Mn-Ni-Si钎料真空钎焊2Cr13不锈钢,研究了钎焊温度和保温时间对接头组织和室温力学性能的影响.结果表明:钎焊接头组织由钎缝中心区Cu-Mn基固溶体和钎缝界面反应区的(Fe,Ni,Mn)- Si化合物组成.随着钎焊温度的增加,钎缝界面处化合物层厚度减小,Cu-Mn基固溶体相应增多,接头室温剪切强度随之增加,在钎焊时间15min、钎焊温度1050℃时达到321 MPa.在钎焊温度1000℃时,接头室温剪切强度随着钎焊保温时间的延长先增加后降低,在钎焊保温时间30min时取得最大值305 MPa.%The effects of brazing temperature and holding time on the microstructure and mechanical property at room-temperature of the brazed stainless steel joint with Cu-Mn-Ni-Si filler metal in vacuum were studied. The results show that the brazed joint is made up of Cu-Mn based solid solution in the middle area of the brazing seam and (Fe.Ni, Mn)-Si intermetallic phase in the reaction area near the interface. The volume of intermetallic phase decreases and joint clearance is primarily occupied by Cu-Mn based solid solution with the increase of brazing temperature, the shear strength of the brazed joint at room-temperature increases with the increase of the brazing temperature and reaches 321 Mpa when brazing holding time is 15 min and brazing temperature is 1050 °C . The shear strength of the brazed joint at room-temperature increases first and then decreases with the increase of the brazing holding times, and reaches 305 Mpa when the brazing holding time is 30 min.

  9. Cathodic stripping voltammetry of trace Mn(II) at carbon film electrodes.

    Science.gov (United States)

    Filipe, Olga M S; Brett, Christopher M A

    2003-12-04

    A sensitive voltammetric method is presented for the determination of tract levels of Mn (II) using carbon film electrodes fabricated from carbon resistors of 2 Omega. Determination of manganese was made by square wave cathodic stripping voltammetry (CSV), with deposition of manganese as manganese dioxide. Chronoamperometric experiments were made to study MnO(2) nucleation and growth. As a result, it was found to be necessary to perform electrode conditioning at a more positive potential to initiate MnO(2) nucleation. Under optimised conditions the detection limit obtained was 4 nM and the relative standard deviation for eight measurements of 0.22 nM was 5.3%. Interferences from various metal ions on the response CSV of Mn(II) were investigated, namely Cd(II), Ni(II), Cu(II), Cr(VI), Pb(II), Zn(II) and Fe(II). Application to environmental samples was demonstrated.

  10. Determinação de Mn, Cu e Zn em matrizes salinas após separação e pré-concentração usando Amberlite XAD-7 impregnada com Vermelho de Alizarina S

    Directory of Open Access Journals (Sweden)

    Santos Júnior Aníbal de Freitas

    2002-01-01

    Full Text Available The aim of this work was to explore the possibility of the application of a non-ionic resin obtained by impregnation of Alizarin Red S (VAS in Amberlite XAD-7 for manganese, copper and zinc separation and preconcentration in saline matrices. For these system, the metals were quantitatively retained, in the pH range 8.5-10.0, by using 0.50 g of solid phase, stirring time of five minutes and a total mass up to 200 mug of each cation. The sorbed elements were subsequently eluted and a fifty-fold, ten-fold and ten-fold preconcentration factor for to Zn, Cu and Mn were obtained, respectively.

  11. Graphite furnace analysis of a series of metals (Cu, Mn, Pb, Zn and Cd) in ox kidney

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Vivianne L.B. de; Nascimento, Rizia K. do; Paiva, Ana Claudia de; Silva, Josenilda M. da, E-mail: vlsouza@cnen.gov.br, E-mail: riziakelia@hotmail.com, E-mail: acpaiva@cnen.gov.br, E-mail: jmnilda@hotmail.com [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil); Melo, Jessica V. de, E-mail: Jessica_clorofila@hotmail.com [Universidade de Pernambuco, Recife, PE (Brazil)

    2013-07-01

    The aim of this study was to create a methodology for animal tissue analysis, with the use of flame atomic absorption spectrophotometry techniques and graphite furnace analysis to determining metal concentrations in ox kidney. The organ of this animal can be considered a great nutritional food, due to the high protein and micronutrient content beyond the ability to absorb and concentrate important metals such as Zn, Fe, Mn and Se. On the other hand, there is a risk when eating this food owing to the capacity to accumulate toxic metals such as Pb and Cd. In accordance with the laboratory analysis, Zn can be analyzed by flame atomic absorption spectrophotometry, but other metals such as Cu, Mn, Pb and Cd, could only be detected by graphite furnace analysis. The results showed that there is more Zn and Cu than other metals. Such metals follows an order reported by the literature (Zn > Cu > Cd > Pb > Mn). The results showed that kidney is actually a rich source of Zn and Cu. The Cd levels in the ox kidney did not exceed the values which cause toxic effects. The adequacy of the results indicates that the proposed methodology can be used for animal tissue analysis.(author)

  12. Manganese(II)-azido/thiocyanato complexes of naphthylazoimidazoles: X-ray structures of Mn(β-NaiEt) 2(X) 2 (β-NaiEt = 1-ethyl-2-(naphthyl-β-azo)imidazole; X=N3-, NCS -)

    Science.gov (United States)

    Das, D.; Chand, B. G.; Wu, J. S.; Lu, T.-H.; Sinha, C.

    2007-10-01

    Manganese(II)-naphthylazoimidazole complexes using N3- and NCS - as counter ions are characterized as Mn(β-NaiR) 2(X) 2(β-NaiEt = 1-alkyl-2-(naphthyl-β-azo)imidazole; X=N3-, NCS -). The ligands are unsymmetric N(imidazole), N(azo) chelating agents. The microanalytical, spectral (FT-IR, UV-vis), magnetic (bulk moment and EPR) and electrochemical data establish the structure and composition of the complexes. The single crystal X-ray diffraction studies of Mn(β-NaiEt) 2(N 3) 2 and Mn(β-NaiEt) 2(NCS) 2(β-NaiEt = 1-ethyl-2-(naphthyl-β-azo)imidazole) have confirmed the three dimensional structure of the complexes. Cyclic voltammetry exhibits high potential Mn(III)/Mn(II) couple along with azo reductions. The EPR spectra show usual pattern.

  13. Photocatalytic water oxidation by a mixed-valent Mn(III)₃Mn(IV)O₃ manganese oxo core that mimics the natural oxygen-evolving center.

    Science.gov (United States)

    Al-Oweini, Rami; Sartorel, Andrea; Bassil, Bassem S; Natali, Mirco; Berardi, Serena; Scandola, Franco; Kortz, Ulrich; Bonchio, Marcella

    2014-10-13

    The functional core of oxygenic photosynthesis is in charge of catalytic water oxidation by a multi-redox Mn(III)/Mn(IV) manifold that evolves through five electronic states (S(i), where i=0-4). The synthetic model system of this catalytic cycle and of its S0→S4 intermediates is the expected turning point for artificial photosynthesis. The tetramanganese-substituted tungstosilicate [Mn(III)3Mn(IV)O3(CH3COO)3(A-α-SiW9O34)](6-)(Mn4POM) offers an unprecedented mimicry of the natural system in its reduced S0 state; it features a hybrid organic-inorganic coordination sphere and is anchored on a polyoxotungstate. Evidence for its photosynthetic properties when combined with [Ru(bpy)3](2+) and S2O8(2-) is obtained by nanosecond laser flash photolysis; its S0→S1 transition within milliseconds and multiple-hole-accumulating properties were studied. Photocatalytic oxygen evolution is achieved in a buffered medium (pH 5) with a quantum efficiency of 1.7%.

  14. Influence of niobium on the hardening phenomenon and wear in the manganese steel (12% Mn destined for the railway

    Directory of Open Access Journals (Sweden)

    Maouche Hichem

    2014-06-01

    Full Text Available This study relates to the manufacture of austenitic manganese steel for the heart switching crossings of railways in all industrial countries where heavy loads are moved by rail. This steel is characterized by a high surface hardness service yard caused by the phenomenon of hardening. According to the microstructure formed after quenching, the transformation of austenite into martensite during working, determine the operating life. The rate of transformation of austenite into martensite can force a compromise between ductility and wear resistance of the steel in order to withstand large forces without breaking. The objective of this study is to improve the resistance to abrasion and friction to cast state and after heat treatment by the addition of niobium. This study permitted to develop a new shade of manganese steel can be integrated into the production of heart of railway switches with better lifecycle.

  15. Influence of niobium on the hardening phenomenon and wear in the manganese steel (12% Mn) destined for the railway

    OpenAIRE

    Maouche Hichem; Hadji Ali; Bouhamla Khedidja

    2014-01-01

    This study relates to the manufacture of austenitic manganese steel for the heart switching crossings of railways in all industrial countries where heavy loads are moved by rail. This steel is characterized by a high surface hardness service yard caused by the phenomenon of hardening. According to the microstructure formed after quenching, the transformation of austenite into martensite during working, determine the operating life. The rate of transformation of austenite into martensite can f...

  16. Hair as a Biomarker of Environmental Manganese Exposure

    Science.gov (United States)

    Eastman, Rachel R.; Jursa, Tom P.; Benedetti, Chiara; Lucchini, Roberto G.; Smith, Donald R.

    2013-01-01

    The absence of well-validated biomarkers of manganese (Mn) exposure in children remains a major obstacle for studies of Mn toxicity. We developed a hair cleaning methodology to establish the utility of hair as an exposure biomarker for Mn and other metals (Pb, Cr, Cu), using ICP-MS, scanning electron microscopy, and laser ablation ICP-MS to evaluate cleaning efficacy. Exogenous metal contamination on hair that was untreated or intentionally contaminated with dust or Mn-contaminated water was effectively removed using a cleaning method of 0.5% Triton X-100 sonication plus 1N nitric acid sonication. This cleaning method was then used on hair samples from children (n=121) in an ongoing study of environmental Mn exposure and related health effects. Mean hair Mn levels were 0.121 μg/g (median = 0.073 μg/g, range = 0.011 – 0.736 μg/g), which are ~4 to 70-fold lower than levels reported in other pediatric Mn studies. Hair Mn levels were also significantly higher in children living in the vicinity of active, but not historic, ferroalloy plant emissions compared to controls (Phair can be effectively cleaned of exogenous metal contamination, and they substantiate the use of hair Mn levels as a biomarker of environmental Mn exposure in children. PMID:23259818

  17. Effect of increased manganese addition and mould type on the slurry erosion characteristics of Cr–Mn iron systems

    Indian Academy of Sciences (India)

    P Sampathkumaran; C Ranganathaiah; S Seetharamu; Kishore

    2008-12-01

    The wear resistance of high chromium iron is well recorded. However, the same is not the case as regards the use of manganese at higher percentages in high chromium irons and its influence on wear behaviour. Hence, this work highlights the slurry wear characteristics of chromium ($\\Box$ 16–19%) iron following the introduction of manganese at two levels i.e. 5 and 10%. It is known that the wear properties are dictated by the microstructural features. To alter the structure, the cooling rate of casting has been varied by adopting two different types of moulds (i.e. sand and metal) and subsequently subjecting to thermal treatment. The as-cast and heat treated samples are examined for microstructure and then evaluated for hardness and slurry erosion properties. As the manganese content is increased from 5 to 10%, the hardness showed a decrease in value both in the as-cast and heat treated conditions. The slurry erosion loss, expectedly, showed an increase irrespective of the sample condition (i.e. mould type/heat treatment adopted). The findings are corroborated with the microstructural features obtained through optical and scanning electron microscopy.

  18. Mn(II) Oxidation by the Multicopper Oxidase Complex Mnx: A Coordinated Two-Stage Mn(II)/(III) and Mn(III)/(IV) Mechanism.

    Science.gov (United States)

    Soldatova, Alexandra V; Romano, Christine A; Tao, Lizhi; Stich, Troy A; Casey, William H; Britt, R David; Tebo, Bradley M; Spiro, Thomas G

    2017-08-23

    The bacterial manganese oxidase MnxG of the Mnx protein complex is unique among multicopper oxidases (MCOs) in carrying out a two-electron metal oxidation, converting Mn(II) to MnO2 nanoparticles. The reaction occurs in two stages: Mn(II) → Mn(III) and Mn(III) → MnO2. In a companion study , we show that the electron transfer from Mn(II) to the low-potential type 1 Cu of MnxG requires an activation step, likely forming a hydroxide bridge at a dinuclear Mn(II) site. Here we study the second oxidation step, using pyrophosphate (PP) as a Mn(III) trap. PP chelates Mn(III) produced by the enzyme and subsequently allows it to become a substrate for the second stage of the reaction. EPR spectroscopy confirms the presence of Mn(III) bound to the enzyme. The Mn(III) oxidation step does not involve direct electron transfer to the enzyme from Mn(III), which is shown by kinetic measurements to be excluded from the Mn(II) binding site. Instead, Mn(III) is proposed to disproportionate at an adjacent polynuclear site, thereby allowing indirect oxidation to Mn(IV) and recycling of Mn(II). PP plays a multifaceted role, slowing the reaction by complexing both Mn(II) and Mn(III) in solution, and also inhibiting catalysis, likely through binding at or near the active site. An overall mechanism for Mnx-catalyzed MnO2 production from Mn(II) is presented.

  19. Coprecipitation and redox reactions of manganese oxides with copper and nickel

    Science.gov (United States)

    Hem, J.D.; Lind, Carol J.; Roberson, C.E.

    1989-01-01

    Open-system, continuous-titration experiments have been done in which a slow flux of ???0.02 molar solution of Mn2+ chloride, nitrate, or perchlorate with Cu2+ or Ni2+ in lesser concentrations was introduced into an aerated reactor solution held at constant temperature and at constant pH by a pH-stat titrator that added dilute NaOH. The resulting mixtures of metal oxyhydroxides and their native solutions were aged for periods as long as 2 1/2 years. Fresh and aged precipitates were characterized by chemical analysis, oxidation state determinations, X-ray and electron diffraction, and electron microscopy. The precipitates can be described as mixtures of oxide and oxyhydroxide species, using concepts of equilibrium and nonequilibrium chemical thermodynamics. The metal-ion content of the aged precipitates in systems that contained copper is distributed among three principal components. One of these is a mixed oxide Cu2Mn3O8 in which all Mn is in the 4+ oxidation state. A major component in all precipitates is feitknechtite, ??MnOOH. These forms are supplemented by CuO or by birnessite or ramsdellite forms of MnO2 where stoichiometry and thermodynamic calculations predict them. In systems that contained nickel and manganese, identifiable components included ??MnOOH, Ni(OH)2, and the same two forms of MnO2. The oxidation number of the precipitated manganese increased during aging, and the pH of the supernatant solution decreased. The maximum Mn oxidation number observed was 3.55 in an Mn + Cu precipitate aged for 18 months. Concentrations of Cu2+ and Ni2+ generally decreased to values substantially below those predicted by oxide or hydroxide equilibrium. Scavenging effects of this type are common in natural aqueous systems. ?? 1989.

  20. Nonequilibrium Thermodynamic Model of Manganese Carbonate Oxidation

    Institute of Scientific and Technical Information of China (English)

    郝瑞霞; 彭省临

    1999-01-01

    Manganese carbonate can be converted to many kinds of manganese oxides when it is aerated in air and oxygen.Pure manganese carbonate can be changed into Mn3O4 and γ-MnOOH,and manganese carbonate ore can be converted to MnO2 under the air-aerating and oxygen-aerating circumstances.The oxidation process of manganese carbonate is a changing process of mineral association,and is also a converting process of valence of manganese itself.Not only equilibrium stat,but also nonequilibrium state are involved in this whole process,This process is an irreversible heterogeneous complex reaction,and oberys the nonequilibrium thermodynamic model,The oxidation rate of manganese cabonate is controlled by many factors,especially nonmanganese metallic ions which play an important role in the oxidation process of manganese carbonate.

  1. Fast-neutron induced pre-equilibrium reactions on 55Mn and 63,65Cu at energies up to 40 MeV

    CERN Document Server

    Avrigeanu, M; Filatenkov, A A; Forrest, R A; Herman, M; Köning, A J; Plompen, A J M; Roman, F L; Avrigeanu, V

    2007-01-01

    Excitation functions were measured for the $^{55}$Mn(n,2n)$^{54}$Mn, $^{55}$Mn(n,$\\alpha$)$^{52}$V, $^{63}$Cu(n,$\\alpha$)$^{60}$Co, $^{65}$Cu(n,2n)$^{64}$Cu, and $^{65}$Cu(n,p)$^{65}$Ni reactions from 13.47 to 14.83 MeV. The experimental cross sections are compared with the results of calculations including all activation channels for the stable isotopes of Mn and Cu, for neutron incident energies up to 50 MeV. Within the energy range up to 20 MeV the model calculations are most sensitive to the parameters related to nuclei in the early stages of the reaction, while the model assumptions are better established by analysis of the data in the energy range 20-40 MeV. While the present analysis has taken advantage of both a new set of accurate measured cross sections around 14 MeV and the larger data basis fortunately available between 20 and 40 MeV for the Mn and Cu isotopes, the need of additional measurements below as well as above 40 MeV is pointed out. Keywords: 55Mn, 63,65Cu, E$\\leq$40 MeV, Neutron activati...

  2. Ising-like chain magnetism, Arrhenius magnetic relaxation, and case against 3D magnetic ordering in β-manganese phthalocyanine (C32H16MnN8)

    Science.gov (United States)

    Wang, Zhengjun; Seehra, Mohindar S.

    2016-04-01

    Previous magnetic studies in the organic semiconductor β-manganese phthalocyanine (β-MnPc) have reported it to be a canted ferromagnet below T C  ≈  8.6 K. However, the recent result of the lack of a λ-type anomaly in the specific heat versus temperature data near the quoted T C has questioned the presence of long-range 3-dimensional (3D) magnetic ordering in this system. In this paper, detailed measurements and analysis of the temperature (2 K-300 K) and magnetic field (up to 90 kOe) dependence of the dc and ac magnetic susceptibilities in a powder sample of β-MnPc leads us to conclude that 3D long-range magnetic ordering is absent in this material. This is supported by the Arrott plots and the lack of a peak in the ac susceptibilities, χ‧ and χ″, near the quoted T C. Instead, the system can be best described as an Ising-like chain magnet with Arrhenius relaxation of the magnetization governed by an intra-layer ferromagnetic exchange constant J/k B  =  2.6 K and the single ion anisotropy energy parameter |D|/k B  =  8.3 K. The absence of 3D long range order is consistent with the measured \\mid D\\mid   >  J.

  3. Ising-like chain magnetism, Arrhenius magnetic relaxation, and case against 3D magnetic ordering in β-manganese phthalocyanine (C₃₂H₁₆MnN₈).

    Science.gov (United States)

    Wang, Zhengjun; Seehra, Mohindar S

    2016-04-06

    Previous magnetic studies in the organic semiconductor β-manganese phthalocyanine (β-MnPc) have reported it to be a canted ferromagnet below T(C)  ≈  8.6 K. However, the recent result of the lack of a λ-type anomaly in the specific heat versus temperature data near the quoted T(C) has questioned the presence of long-range 3-dimensional (3D) magnetic ordering in this system. In this paper, detailed measurements and analysis of the temperature (2 K-300 K) and magnetic field (up to 90 kOe) dependence of the dc and ac magnetic susceptibilities in a powder sample of β-MnPc leads us to conclude that 3D long-range magnetic ordering is absent in this material. This is supported by the Arrott plots and the lack of a peak in the ac susceptibilities, χ' and χ″, near the quoted T(C). Instead, the system can be best described as an Ising-like chain magnet with Arrhenius relaxation of the magnetization governed by an intra-layer ferromagnetic exchange constant J/k(B)  =  2.6 K and the single ion anisotropy energy parameter |D|/k(B)  =  8.3 K. The absence of 3D long range order is consistent with the measured |D|/  >  J.

  4. Microstructure and microhardness of nanostructured Al-4.6Cu-Mn alloy ribbons

    Institute of Scientific and Technical Information of China (English)

    Zhong-wei Chen; Qin-ying Fan; Kai Zhao

    2015-01-01

    The microstructural characteristics and microhardness of nanostructured Al−4.6Cu−Mn ribbons produced by melt spinning were investigated using field-emission gun scanning electron microscopy, transmission electron microscopy, and hardness testing, and the results were compared to those of similar ribbons manufactured by direct-chill casting. It is shown that the nanostructure of the as-melt-spun ribbons consists ofα-Al dendrites with a secondary dendrite arm spacing of approximately 0.55−0.80μm and ultrafine eutectic crystals of a nanosized scale of approximately 100−200 nm on dendritic boundaries. The solidification time and cooling rate of 46-μm-thick ribbons were estimated to be 1.3 × 10−6 s and 4.04 × 106 K·s−1, respectively. At an aging temperature of 190°C, thecoherentθ″ phase in aged ribbons gradually transforms into nanoscaleθ′-phase platelets as the aging time is extended from 2 to 8 h; the rod-like morphology of the T (Al20Cu2Mn3) dispersoid with 120−160-nm diameter also forms, which results in peak aging hardness. The precipitation behaviors of aged ribbons cannot be changed at the high cooling rates of as-cast ribbons. However, a finer and more uniformly distributed microstructure and a supersaturated solid solution at a high cooling rate can shorten the time required to obtain a certain aging hardness before peak hardness.

  5. Martensitic transformation and magnetic properties of manganese-rich Ni-Mn-In and Ni-Mn-Sn Heusler alloys; Untersuchung der martensitischen Umwandlung und der magnetischen Eigenschaften Mangan-reicher Ni-Mn-In- und Ni-Mn-Sn-Heusler-Legierungen

    Energy Technology Data Exchange (ETDEWEB)

    Krenke, T.

    2007-06-29

    In the present work, the martensitic transition and the magnetic properties of Manganese rich Ni{sub 50}Mn{sub 50-x}Sn{sub x} and Ni{sub 50}Mn{sub 50-y}In{sub y} alloys with 5 at%{<=}x(y){<=}25 at% were investigated. Calorimetry, X-ray and neutron diffraction, magnetization, and strain measurements were performed on polycrystalline samples. It was shown that alloys close to the stoichiometric composition Ni{sub 50}Mn{sub 25}Sn{sub 25} and Ni{sub 50}Mn{sub 25}Sn{sub 25} do not exhibit a structural transition on lowering of the temperature, whereas alloys with x{<=}15 at% Tin and y{<=}16 at% Indium transform martensitically. The structural transition temperatures increase linearly with decreasing Tin or Indium content. The crystal structures of the low temperature martensite are modulated as well as unmodulated. Alloys with compositions close to stoichiometry are dominated by ferromagnetic interactions, whereas those close to the binary composition Ni{sub 50}Mn{sub 50} order antiferromagnetically. Ferromagnetic order and structural instability coexist in a narrow composition range between 13 at%{<=}x{<=}15 at% and 15 at%{<=}x{<=}16 at% for Ni{sub 50}Mn{sub 50-x}Sn{sub x} and Ni{sub 50}Mn{sub 50-y}In{sub y} respectively. As a consequence, interesting magnetoelastic effects are observed. The Ni{sub 50}Mn{sub 34}In{sub 16} alloy shows a magnetic field-induced structural transition, whereby application of an external magnetic field in the martensitic state stabilizes the high temperature L2{sub 1} structure. Evidence for this was given by neutron diffraction experiments in external magnetic fields. Moreover, the structural transition temperatures of this alloy show large magnetic field dependencies. By use of calorimetry, M(T), and strain measurements, changes in M{sub s} up to -11 K/Tesla are observed. Such large values have, until now, not been observed in Heusler alloys. Since during transformation the volume changes reversibly, magnetic field-induced strains of about

  6. Manganese-rich MnSAPO-34 molecular sieves as an efficient catalyst for the selective catalytic reduction of NO x with NH3: one-pot synthesis, catalytic performance, and characterization.

    Science.gov (United States)

    Yu, Chenglong; Chen, Feng; Dong, Lifu; Liu, Xiaoqing; Huang, Bichun; Wang, Xinnan; Zhong, Shengbang

    2017-03-01

    Manganese-rich MnSAPO-34 molecular sieves were prepared by one-pot synthesis method for NO x abatement using the ammonia-selective catalytic reduction (NH3-SCR) technology and characterized using ICP, BET, XRD, FE-SEM, H2-TPR, NH3-TPD, XPS, and DR UV-Vis analyses. The experimental results indicate that the Mn content and chemical state, as well as the surface acidity, of the MnSAPO-34 molecular sieves significantly enhance their DeNO x efficiency at low temperatures (ca. 200-300 °C). The manganese-rich MnSAPO-34 was synthesized using a combination of triethylamine and diisopropylamine as the structural directing agents and high Mn loading (n(MnO)/n(P2O5) = 0.4). The resulting catalyst exhibits the highest activity among all of the samples with a NO x conversion value of nearly 95% and a N2 selectivity that is higher than 90% at 220-400 °C. In addition, this catalyst presents higher NO x conversion than the conventional V2O5-WO3/TiO2 catalysts and other SAPO-based catalysts below 300 °C. Furthermore, the analytical results indicate that the manganese species in the catalyst are mainly in the form of a framework Mn(IV), which could play a significant role in the NH3-SCR process as the specific active species. The results suggest that controlling the types and content of the organic amine templates and variations in the surface acidity of the catalysts may significantly enhance the SCR activity at lower temperatures.

  7. Studies on effects of superiority strains on bioleaching of Mn from electrolytic manganese residues%优势菌种浸取电解锰渣中锰的影响因素研究

    Institute of Scientific and Technical Information of China (English)

    黄华军; 李小明; 曹建兵; 张忠辉; 李焕利; 方丽; 杨慧; 杨麒; 刘精今

    2011-01-01

    采用电解锰废渣中分离出的一种锰抗性强的微生物Fusarium sp.浸取电解锰渣中的锰。研究了不同矿浆浓度、微生物生长活动、锰渣和培养基等对锰浸取效率的影响。结果表明,接种体积比为2%(v/v)时,矿浆浓度(m/v)对锰浸取效率影响显著,矿浆浓度过低(〈2%)或者过高(〉10%)对锰浸取效率都有不利影响。矿浆浓度为10%时锰浸取效率最高,达80%以上;微生物的生长活动对浸取过程有显著的影响;而锰渣的存在则能在一定程度上影响溶液的pH,进而影响锰浸取效率;培养基对锰浸取效率的贡献达50%左右。%The micro-organism named Fusarium sp.,which was separated from electrolytic manganese residues,has strong resistance of manganese.A series of microbioleaching experiments were performed using Fusarium sp.to extract manganese from electrolytic manganese residues.The effects of different factors such as pulp density,microbial growth and activity,electrolytic manganese residues and culture medium on the Mn bioleaching efficiency were studied.The results showed that the pulp densities had a significant influence on the Mn bioleaching efficiency when the inoculation volume ratio was 2%.The Mn bioleaching efficiency was inhibited when the pulp densities were too low(〈2%) or too high(〉10%).The highest Mn bioleaching efficiency was obtained when the pulp density was 10%,and it reached more than 80%;microbial growth and activity had a significant impact on bioleaching process.The existence of electrolytic manganese residues affected the pH of the solution to some extent,thereby affecting the Mn bioleaching efficiency.The contribution of culture medium to Mn bioleaching efficiency was about 50%.

  8. EFFECTS OF MANGANESE ON THYROID HORMONE HOMEOSTASIS: POTENTIAL LINKS

    OpenAIRE

    Soldin, OP; Aschner, M.

    2007-01-01

    Manganese (Mn) is an essential trace nutrient that is potentially toxic at high levels of exposure. As a constituent of numerous enzymes and a cofactor, manganese plays an important role in a number of physiologic processes in mammals. The manganese-containing enzyme, manganese superoxide dismutase (Mn-SOD), is the principal antioxidant enzyme which neutralizes the toxic effects of reactive oxygen species. Other manganese-containing enzymes include oxidoreductases, transferases, hydrolases, l...

  9. Reuse of Anode Slime Generated by the Zinc Industry to Obtain a Liquor for Manufacturing Electrolytic Manganese

    Science.gov (United States)

    Ayala, J.; Fernández, B.

    2013-08-01

    A hydrometallurgical process is proposed in this article to recover manganese from a zinc electrowinning residue. The article describes the digestion-leaching experiments, precipitation, and electrowinning assays to recover Mn from this residue. Anode slime is treated with sulfuric acidic in a furnace within a temperature range of 400-450°C, leached with water, and then filtered. The results show that the dissolution of manganese increases with increasing temperature in the digestion step. The recovery yield of manganese was higher than 90%. As manganese electrolysis requires an electrolyte free of Zn, Ni, Co, and Cu pollutants, the sulfuric acid liquor needs a purification step. Na2S is used to remove pollutants. The results obtained in this study have shown that the proposed process for the recovery of manganese from this type of residue is technically viable.

  10. A new mixed-valence lead(II manganese(II/III phosphate(V: PbMnII2MnIII(PO43

    Directory of Open Access Journals (Sweden)

    Ghaleb Alhakmi

    2013-07-01

    Full Text Available The title compound, lead trimanganese tris(orthophosphate, has been synthesized by hydrothermal methods. In this structure, only two O atoms are in general positions and all others atoms are in the special positions of the Imma space group. Indeed, the atoms in the Wyckoff positions are namely: Pb1 and P1 on 4e (mm2; Mn1 on 4b (2/m; Mn2 and P2 on 8g (2; O1 on 8h (m; O2 on 8i (m. The crystal structure can be viewed as a three-dimensional network of corner- and edge-sharing PO4 tetrahedra and MnO6 octahedra, building two types of chains running along the b axis. The first is an infinite linear chain, formed by alternating MnIIIO6 octahedra and PO4 tetrahedra which share one vertex. The second chain is built up from two adjacent edge-sharing octahedra (MnII2O10 dimers whose ends are linked to two PO4 tetrahedra by a common edge. These chains are linked together by common vertices of polyhedra in such a way as to form porous layers parallel to (001. These sheets are bonded by the first linear chains, leading to the appearance of two types of tunnels, one propagating along the a axis and the other along b. The PbII ions are located within the intersections of the tunnels with eight neighbouring O atoms in form of a trigonal prism that is capped by two O atoms on one side. The three-dimensional framework of this structure is compared with similar phosphates such as Ag2Co3(HPO4(PO42 and Ag2Ni3(HPO4(PO42.

  11. Crystal structure of the new diamond-like semiconductor CuMn$_2$InSe$_4$

    Indian Academy of Sciences (India)

    G E DELGADO; V SAGREDO

    2016-12-01

    The crystal structure of the semiconductor compound CuMn$_2$InSe$_4$ was analysed using X-ray powder diffraction data. CuMn$_2$InSe$_4$ crystallizes, with a stannite structure, in the tetragonal space group I$\\bar{4}$2m (No. 121), $Z = 2$, with unit cell parameters $a = 5.8111(2) \\AA$, $c = 11.5739(8) \\AA$ and $V = 390.84(3) \\AA^#$. The refinement of 28 instrumental and structural parameters led to $R_{\\rm p} = 8.1$%, $R_{\\rm wp} = 10.5$%, $R_{\\rm exp} = 6.5$% and $S = 1.6,$ for 86 independent reflections.

  12. Growth of manganese sulfide (α-MnS) thin films by thermal vacuum evaporation: Structural, morphological and optical properties

    Energy Technology Data Exchange (ETDEWEB)

    Hannachi, Amira, E-mail: amira.hannachi88@gmail.com [MALTA-Consolider Team, Institut de Ciència dels Materials – Departamento de Fisica Aplicada, University of Valencia, E-46100 Burjassot, Valencia (Spain); Université de Tunis El-Manar, Faculté des Sciences de Tunis, Laboratoire de Chimie Analytique et Electrochimie, LR99ES15, 2092 Tunis (Tunisia); Segura, Alfredo [MALTA-Consolider Team, Institut de Ciència dels Materials – Departamento de Fisica Aplicada, University of Valencia, E-46100 Burjassot, Valencia (Spain); Maghraoui-Meherzi, Hager [Université de Tunis El-Manar, Faculté des Sciences de Tunis, Laboratoire de Chimie Analytique et Electrochimie, LR99ES15, 2092 Tunis (Tunisia)

    2016-09-15

    MnS thin films have been successfully prepared by thermal evaporation method at different substrate temperatures using different masses of MnS powder. The prepared films were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX) and UV–visible spectrophotometry. The XRD measurements show that the films crystallized in the pure α-MnS for substrate temperatures above 100 °C. The optical bandgap of thin films is found to be in the range of 3.2–3.3 eV. A factorial experimental design was used for determining the influence of the two experimental parameters on the films growth. - Highlights: • α-MnS films were deposited on glass and quartz substrates using the thermal evaporation technique. • The effect of substrate temperature on the properties of the MnS films has been studied. • The factorial design was used to determine the most influence parameters.

  13. Manganese Oxidation by Bacteria: Biogeochemical Aspects

    Digital Repository Service at National Institute of Oceanography (India)

    Sujith, P.P.; LokaBharathi, P.A.

    Manganese is an essential trace metal that is not as readily oxidizable like iron. Several bacterial groups posses the ability to oxidize Mn effectively competing with chemical oxidation. The oxides of Mn are the strongest of the oxidants, next...

  14. Effects of annealing on the GMR and domain structure stabilization in a Py/Cu/Py/MnIr spin valve

    Energy Technology Data Exchange (ETDEWEB)

    Lee, C.-G. E-mail: cglee@sarim.charngwon.ac.kr; Jung, J.-G.; Gornakov, V.S.; McMichael, R.D.; Chen, A.; Egelhoff, W.F

    2004-05-01

    The thermal stability of magnetic and magnetotransport properties of a Py/Cu/Py/Ir{sub 20}Mn{sub 80} spin-valve system were studied. The dependence of the magnetoresistance (MR) and the magnetic domain structures of the spin-valve on anneal temperature were measured. Domain imaging revealed that increasing anneal temperature leads to changes in the exchange coupling between the two ferromagnetic layers showing regions of antiferromagnetically coupled layers, which appeared in ferromagnetically coupled area after cooling.

  15. Heating ability of La-Sr-Mn-Cu perovskite spheres under an alternating current magnetic field for magnetic hyperthermia mediators

    Energy Technology Data Exchange (ETDEWEB)

    Horiki, Mayumi [Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan); Nakagawa, Takashi, E-mail: nakagawa@mit.eng.osaka-u.ac.jp [Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan); Seino, Satoshi; Yamamoto, Takao A. [Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan)

    2013-03-15

    La{sub 0.666}Sr{sub 0.373}Mn{sub 0.943}Cu{sub 0.018}O{sub 3} spheres (average diameter: 2.4 mm) were used as magnetic hyperthermia mediators. They were prepared by the polymerized complex method and alginate gelation. A starch paste containing nine such spheres (0.1034 g) was maintained at a constant temperature when it was exposed to an alternating current magnetic field (frequency: 1 MHz; magnetic field strength: 20-55 Oe-rms). After exposure to a magnetic field with a field strength of 55 Oe-rms for 60 min, a temperature of T{sub 60}=73.5 Degree-Sign C was obtained. T{sub 60} for field strengths of 40 and 55 Oe-rms differed by only 2.6 Degree-Sign C. La{sub 0.666}Sr{sub 0.373}Mn{sub 0.943}Cu{sub 0.018}O{sub 3} spheres satisfy the following important requirements for heating mediators: their amount can be controlled in tumors, their temperature can be controlled without monitoring, and their heating ability is independent of the field strength and direction. Thus, La{sub 0.666}Sr{sub 0.373}Mn{sub 0.943}Cu{sub 0.018}O{sub 3} spheres are promising heating mediators for inducing magnetic hyperthermia. - Highlights: Black-Right-Pointing-Pointer We prepared La-Sr-Mn-Cu perovskite spheres used as magnetic hyperthermia mediators. Black-Right-Pointing-Pointer Our perovskite spheres were maintained at a constant temperature under AC field. Black-Right-Pointing-Pointer The heating ability is independent of the field strength and direction.

  16. Influence of Heating Rate on Double Reversible Transformation in CuZnAlMnNi Shape Memory Alloy

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The influence of heating rate on double reversible transformation in CuZnA1MnNi shape memory alloy was investigated by differential scanning calorimetry. It was found that rapid heating inhibits X→M transformation but is fa vorable to the reverse martensite transformation, giving rise to the approach of the two transformation peaks. With the decrease of heating rate, the two transformation peaks separate gradually.

  17. Concentrations of Zn, Mn, Cu and Cd in different tissues of perch (Perca fluviatilis) and in perch intestinal parasite (Acanthocephalus lucii) from the stream near Prague (Czech Republic)

    Energy Technology Data Exchange (ETDEWEB)

    Jankovska, Ivana, E-mail: jankovska@af.czu.cz [Department of Zoology and Fisheries, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences, 165 21 Prague 6 - Suchdol (Czech Republic); Miholova, Daniela [Department of Chemistry, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences, 165 21 Prague 6 - Suchdol (Czech Republic); Lukesova, Daniela [Department of Animal Science and Food Processing in Tropics and Subtropics, Institute of Tropics and Subtropics, Czech University of Life Sciences, 165 21 Prague 6 - Suchdol (Czech Republic); Kalous, Lukas; Valek, Petr; Romocusky, Stepan; Vadlejch, Jaroslav; Petrtyl, Miloslav; Langrova, Iva; Cadkova, Zuzana [Department of Zoology and Fisheries, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences, 165 21 Prague 6 - Suchdol (Czech Republic)

    2012-01-15

    We monitored concentrations of Cd, Cu, Mn and Zn in acantocephalan parasites (Acanthocephalus lucii) and its final host (Perca fluviatilis). The concentrations in parasites were found to be significantly higher than those found in the muscle, gonads and liver of fish host. The bioaccumulation factor values were 194, 24.4, 2.2 and 4.7 for Cd, Cu, Mn and Zn, respectively. This suggests a benefit for the host due to the high accumulation of toxic cadmium.

  18. Finite size effects and spin transition in ball-milled γ-(FeMn) 30Cu 70 nanostructured alloys

    Science.gov (United States)

    Restrepo, J.; Greneche, J. M.; González, J. M.

    2004-12-01

    Fe 15Mn 15Cu 70 alloys were prepared by high-energy ball milling over a wide range of grinding times from 15 min to 72 h. The corresponding magnetic properties were followed by means of vibrating sample magnetometry, magnetic susceptibility and Mössbauer spectroscopy. By using a Rietveld structural analysis of high-resolution X-ray diffraction data, lattice parameter and grain size correlations with magnetization and coercive force were carried out. Results revealed a strong microstructural dependence of the magnetic properties with the grain size, resembling a finite size-driven magnetic transition at a critical crystallite value of around 8.5 nm. This behavior is endorsed by a partial low- to high-spin transition according to isomer shift results, at a critical unit-cell volume of around 50 Å 3 at 77 K attributed to strong local variations of the interatomic spacing as a consequence of the employed ball-milling procedure. Finally, as concerns to temperature behavior, samples exhibited a freezing temperature at around 61 K and a wide distribution of relaxation times ascribed to the presence of interacting CuMn and FeMnCu clusters.

  19. Electrical Conductivity of Sintered Chromia Mixed with TiO2,CuO and Mn-Oxides

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The electrical conductivity of sintered Cr2O3 mixed with 2% and 5% (in molar fraction) TiO2 or CuO was investigated in the temperature range 500~900℃ in air and in Ar/4 vol. pct H2 atmospheres. The effect of different Mn-oxides on the electrical conductivity of Cr2O3 was also studied under the same conditions.From the conductivity measurements it is established that additions of TiO2 change the defect structure of Cr2O3 and the effect of TiO2 on the electrical conductivity is controlled by TiO2 concentration as well as temperature and O2 partial pressure of the surrounding atmosphere. The conductivity of Cr2O3 increased in air and decreased in the Ar/H2 atmosphere by CuO additions. The effect of CuO was discussed with possible changes in the defect concentration in Cr2O3. Mixing of Cr2O3 with different Mn-oxides at the same Mn to metal atom fraction decreased the conductivity in air and in Ar/H2 atmospheres. No clear correlation between the spinel fraction and the changes in conductivity could be found.

  20. Dynamic Recrystallization and Precipitation Behavior of Mn-Cu-V Weathering Steel

    Institute of Scientific and Technical Information of China (English)

    Hongyan Wu; Linxiu Du; Xianghua Liu

    2011-01-01

    The hot deformation behavior of a Mn-Cu-V weathering steel was investigated at temperatures ranging from 850 to 1050℃ and strain rates ranging from 0.01 to 5 s-1 using MMS-300 thermal-mechanical simulator. The activation energy for dynamic recrystallization and stress exponent were calculated to be 551 kJ/mol and 7.73, respectively. The accurate values of critical strain were determined by the relationship between work hardening rate and flow stress (θ-σ) curves. The hyperbolic sine constitutive equation was employed to describe the relationship between the peak stress and Zener-Hollomon parameter during hot deformation. The interaction between dynamic recrystallization and dynamic precipitation of V(C,N) at a low strain rate was analyzed. The results showed that precipitation particles size of weathering steel increased with increasing strain at deformation temperature 950℃ and strain rate 0.1 s-1. The calculation results of the recrystallization driving force and pinning force showed that dynamic precipitation could retard the progress of dynamic recrystallization but not prevent it while the pinning forces is less than driving force. On the contrary, dynamic precipitation can effectively prevent the progress of dynamic recrystallization.

  1. Thermophysical Properties of Manganin (Cu86Mn12Ni2) in the Solid and Liquid State

    Science.gov (United States)

    Schmon, A.; Aziz, K.; Luckabauer, M.; Pottlacher, G.

    2015-07-01

    Manganin is the trademark name of the alloy Cu86Mn12Ni2. Despite its frequent usage in manufacturing processes, literature data are scarce particularly at higher temperatures. This work presents a set of thermophysical data of this alloy in a temperature range above its classic area of application up to the end of its liquid phase. For investigating the alloy, four examination setups were employed. Using differential thermal analysis, solidus and liquidus temperatures were obtained. In the solid phase, the electrical resistivity as a function of temperature was determined by a four-point probe positioned in a furnace. Thermal expansion was measured with a high-resolution two-beam laser dilatometer based on Michelson-interferometry and thereby density was calculated. The liquid state was investigated using a s-ohmic-pulse-heating setup. Wire-shaped specimens were resistively volume heated as part of an electrical discharge circuit. Measured quantities were the current through the specimen, the voltage drop along the specimen, the surface radiance by a pyrometer, and the thermal expansion with an adapted CCD camera system. On the basis of these measurements, temperature-dependent thermophysical properties of enthalpy, isobaric heat capacity, electrical resistivity, and density are obtained. Additionally the thermal conductivity and thermal diffusivity are estimated in the high-temperature range applying the Wiedemann-Franz law.

  2. Synthesis and catalytic property of Cu-Mn-Ce/ γ -Al2O3 complex oxide

    Institute of Scientific and Technical Information of China (English)

    黄可龙; 王红霞; 刘素琴; 桂客

    2002-01-01

    A new type of catalytic material for purification of automobile exhaust,Cu-Mn-Ce-O/ γ -Al2O3,has been studied.The factors affecting its catalytic activity,such as calcination temperature and the period of calcinations and so on have been investigated.Its catalytic activity after SO2-poisoning was determined in a fixed-bed reactor by exposing the sample to the atmosphere of 160 mL/min SO2/air.The study reveals that the catalyst has shown high catalytic activities for the conversion of NH3 oxidation by NO after sulfate.The conversion of NO reduction over the sulfated catalyst is somewhat higher than that over the fresh catalyst except that the optimum temperature has increased about 100 ℃.Also at the optimum process for the experiment,the selective catalytic oxidation of CO by NO is over 76% and the conversion of NO reduction is over 80% by NH3.

  3. Síntese e caracterização de óxido hidróxido de manganês do tipo manganita (γ -MnOOH Synthesis and characterization of manganese oxyhydroxide manganite (γ -MnOOH type

    Directory of Open Access Journals (Sweden)

    B. A. M. Figueira

    2008-06-01

    Full Text Available Óxido hidróxido de manganês (γ - MnOOH do tipo da manganita foi sintetizado por uma rota simples, em que a chave precursora K-birnessita foi preparada pelo método sol-gel. O tratamento hidrotermal da estrutura lamelar do tipo da birnessita favorece a obtenção de estruturas em túnel, sendo que o tamanho destes túneis depende das condições empregadas na síntese (pH, temperatura e tempo. A comprovação da formação de manganita sob as condições de síntese empregadas foi verificada pelas técnicas de difração de raios X, microscopia eletrônica de varredura, análises termogravimétrica e térmica diferencial e espectroscopia de infravermelho.Manganese oxyhydroxide (g - MnOOH of the manganite type has been synthesized by a simple route with K-birnessite prepared by the sol-gel method. The hydrothermal treatment of the lamellar birnessite type structure facilitates the formation of tunnel structures where the size of the tunnels depends on the synthesis conditions (pH, temperature and time. The evidence of manganite formation under the synthesis conditions were made by X-ray diffraction, scanning electron microscopy, thermogravimetry, differential thermal analysis and infrared spectroscopy.

  4. A new series of oxycarbonate superconductors (Cu(0.5)C(0.5))(m)Ba(m+1)Ca(n-1)Cu(n)O2(m+n)+1

    Science.gov (United States)

    Takayama-Muromachi, E.; Kawashima, T.; Matsui, Y.

    1995-01-01

    We found a new series of oxycarbonate superconductors in the Ba-CaCu-C-O system under high pressure of 5 GPa. Their ideal formula is (Cu(0.5)C(0.5)(m)Ba(m+1)Ca(n-1)Cu(n)O2)((m+n)+1) ((Cu,C)-m(m+1)(n-1)n). Thus far, n = 3, 4 members of the m = 1 series, (Cu,C)-1223 and (Cu,C)-1234, have been prepared in bulk while n = 4, 5 members, (Cu,C)-2334 and (Cu,C)-2345, have been prepared for the m = 2 series. (Cu,C)-1223 shows superconductivity below 67 K while T(sub c)'s of other compounds are above 110 K. In particular, (Cu,C)-1234 has the highest T(sub c) of 117 K.

  5. Ship-Borne Geochemical Investigations of Deep-Sea Manganese-Nodule Deposits in the Pacific Using a Radioisotope Energy-Dispersive X-Ray System

    DEFF Research Database (Denmark)

    Friedrich, G.H.W.; Kunzendorf, Helmar; Plüger, W.L.

    1974-01-01

    ) detector with a measured energy resolution of 195 eV for Mn Kα X-rays, standard nuclear electronics, a 1024-channel analyser and a data read-out unit. The X-ray spectra in the manganese-nodule samples were excited by a 30-mCi 238Pu source. The six elements Mn, Fe, Co, Ni, Cu and Zn were analysed on board....... Precision values for the analyses were less than 3% for Mn, Fe, Ni, Cu and Zn and about 5% for Co. A total amount of 350 analyses was carried out during a one-month cruise. Average contents of 190 analysed whole manganese-nodule samples from all the sampling sites of the covered area were 23.3% Mn, 6.7% Fe...

  6. Movement disorder symptoms associated with Unified Parkinson’s Disease Rating Scale (UPDRS) in two manganese (Mn)-exposed communities

    Science.gov (United States)

    Objectives: The UPDRS is a commonly used neurological measurement to assess the presence and severity of parkinsonian symptoms. It has also been used to assess symptoms associated with Mn exposure. Objectives: to determine 1) if movement disorder symptoms were associated with UP...

  7. High-level expression of a manganese superoxide dismutase (PoMn-SOD) from Pleurotus ostreatus in Pichia pastoris.

    Science.gov (United States)

    Yin, Chaomin; Zhao, Wenxia; Zheng, Liesheng; Chen, Liguo; Tan, Qi; Shang, Xiaodong; Ma, Aimin

    2014-09-01

    The full-length cDNA of Pleurotus ostreatus superoxide dismutase (PoMn-SOD) was cloned and successfully expressed by using the pPIC9K vector under the control of alcohol oxidase 1 promoter with a secretion signal peptide (α-factor) in Pichia pastoris. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blotting demonstrated that recombinant PoMn-SOD, a 21.8 kDa protein, was secreted into the culture medium. Nondenaturing PAGE experiments confirmed that recombinant PoMn-SOD was secreted in a functionally active form and the expression system did not require any acid activation process. The factors affecting the expression level were optimized in shaking flask cultures. The maximum enzyme activity (156.9 U/mg) was observed under the following conditions: Initial medium pH was 6.0, induction time point was at the 6th day, and methanol concentration was 0.7 % (v/v). This was the first report on secretory expression of recombinant PoMn-SOD in P. pastoris, which might provide a reference for further practical applications.

  8. Movement disorder symptoms associated with Unified Parkinson’s Disease Rating Scale (UPDRS) in two manganese (Mn)-exposed communities

    Science.gov (United States)

    Objectives: The UPDRS is a commonly used neurological measurement to assess the presence and severity of parkinsonian symptoms. It has also been used to assess symptoms associated with Mn exposure. Objectives: to determine 1) if movement disorder symptoms were associated with UP...

  9. The effect of solid solution treatment on the hardness and microstructure of 0.6%wt C-10.8%wt Mn-1.44%wt Cr austenitic manganese steel

    Science.gov (United States)

    Nurjaman, F.; Bahfie, F.; Astuti, W.; Shofi, A.

    2017-04-01

    Austenitic manganese steel is steel alloy that has high manganese content (10-14%wt Mn). The characteristics of austenitic manganese steel are good in toughness, ductility, and wear resistance. Effect of solid solution treatment on the hardness and microstructure of austenitic manganese steel was studied in this experiment. The solid solution treatment process of austenitic manganese steel, 0.6%wt C-10.8%wt Mn-1.44%wt Cr, was conducted by heating the material at varied temperatures (950°C, 1000°C, 1050°C) for an hour and then quenching it in two different quenching media, i.e. oil and water. Further, the samples were tempered at three different temperatures (300°C, 400°C, and 500°C) for 2 hours. The treated materials were analyzed by Rockwell Hardness Tester to obtain the information of materials hardness and by an optical microscope and XRD to investigate the microstructure phase of the treated materials. Heating the austenitic manganese steel at 950°C for an hour followed by water quenching dissolved all carbide in as-cast condition and resulted the fully austenitic on its microstructure. Carbide precipitation occurred due to the prolongation of soaking time in solid solution treatment and tempering process. The optimum hardness of sample was 53.3 HRC, which was resulted by heating this material until 1000°C for an hour, followed by water quenching and tempering at 400°C for 2 hours.

  10. Role of ion beam excitations on quasi one-dimensional magnetic system of Mn-doped LiCuVO{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Abhishek [Department of Physics, Indian Institute of Technology (Banaras Hindu University), Varanasi 221005 (India); Dwivedi, G.D.; Kumar, Shiv [Departments of Physics, Banaras Hindu University, Varanasi 221005 (India); Shahi, P.; Shukla, K.K. [Department of Physics, Indian Institute of Technology (Banaras Hindu University), Varanasi 221005 (India); Ghosh, A.K. [Departments of Physics, Banaras Hindu University, Varanasi 221005 (India); Asokan, K.; Kanjilal, D. [Inter University Accelerator Center, ArunaAsaf Ali Marg, New Delhi 110067 (India); Singh, R.K. [Departments of Physics, Banaras Hindu University, Varanasi 221005 (India); Nigam, A.K. [Department of CMP & MS, Tata Institute of Fundamental Research, Mumbai 400 005 (India); Chatterjee, Sandip, E-mail: schatterji.app@iitbhu.ac.in [Department of Physics, Indian Institute of Technology (Banaras Hindu University), Varanasi 221005 (India)

    2015-07-01

    Induction of short range ferromagnetic ordering has been observed in the quasi one dimensional antiferromagnetic LiCuVO{sub 4} system with doping of Mn in the octahedral (Cu) site. Though, magnetic ordering is not stable enough as further increase of Mn-concentration, magnetic ordering gets deteriorated. This might be the case that Mn{sup 2+} ions, with strong magnetic moment as compared to Cu{sup 2+} ions, enhance the ferromagnetic coupling between the nearest neighbor atoms of quasi-one-dimensional magnetic LiCuVO{sub 4} system. Ferromagnetic ordering in LiCu{sub 0.95}Mn{sub 0.05}VO{sub 4} system also degraded after high energy ion beam excitation which creates defects and may disturb the short range ferromagnetic ordering in its near locality but it does not have much effect on the long range antiferromagnetic ordering. Irradiation causes no change in Raman modes of LiCu{sub 0.95}Mn{sub 0.05}VO{sub 4} system, while it produces some new vibrational modes in intermediate and high frequency region of LiCu{sub 0.9}Mn{sub 0.1}VO{sub 4} system. Above results have been understood based on competitions between ferromagnetic nearest neighbor (NN) coupling and antiferromagnetic next nearest neighbor (NNN) coupling in CuO{sub 2} chain. - Highlights: • Quasi 1-D magnetic systems LiCu{sub 1-x}Mn{sub x}VO{sub 4} (x = 0.00, 0.05 & 0.10) have been prepared. • Doping of Mn induces short range ferromagnetic ordering in the system. • High-energy ion beam excitations degrade ferromagnetic ordering in Mn doped LiCuVO{sub 4}. • Irradiations decay short range FM order but has no effect on long range AFM order. • Irradiation leads to few new vibrational modes in LiCu{sub 0.9}Mn{sub 0.1}VO{sub 4} system.

  11. 富银锰结核银锰分离的试验研究%Research on Separating Ag and Mn from Silver-rich Manganese Nodules

    Institute of Scientific and Technical Information of China (English)

    丁先胜; 徐本军; 徐育; 肖臻

    2012-01-01

    Experiment was conducted on the leaching of silver-rich manganese nodules in sulfuric acid medium by using compound reducing agent A + B as reductant. The effects of sulfuric acid consumption, L/S ratio and reaction time on leaching results were investigated, and the leaching mechanism was also discussed. The optimum conditions for separating Mn and Ag were obtained as follows; 35 mL sulfuric acid per 100 g ore, L/S ratio of 3: 1 and reaction time of 4 hours. Under such conditions, the leaching rate of manganese reached above 90% , and the grade of silver improved from 274 g/t in the original ore to 700 g/t in the leaching residue with silver recovery rate reaching above 95%.%以复合还原剂A+B作为还原剂在硫酸介质下对富银锰结核进行浸出研究.考察了硫酸用量、液固比和反应时间对浸出结果的影响,并对浸出机理进行了探讨.得到最佳的Mn、Ag分离条件为:硫酸35 mL/100 g矿、液固比3∶1、反应时间4h.在此浸出条件下,锰的浸出率达到90%以上,银的品位从原矿中274 g/t提高到浸出渣中700 g/t,且银的回收率达到95%以上.

  12. Characterization and decolorization applicability of xerogel matrix immobilized manganese peroxidase produced from Trametes versicolor IBL-04.

    Science.gov (United States)

    Iqbal, Hafiz Muhammad Nasir; Asgher, Muhammad

    2013-05-01

    A novel manganese peroxidase (MnP) isolated from solid state culture of Trametes versicolor IBL-04 was immobilized using xerogel matrix composed of trimethoxysilane (TMOS) and propyltetramethoxysilane (PTMS). FTIR spectroscopy confirmed the successful entrapment of MnP into the xerogel matrix. An immobilization efficiency of 92.2% was achieved with a purified active fraction containing 2 mg/mL MnP. After 24 h incubation at varying pH and temperatures, the immobilized MnP retained 82 and 75% activity at pH 4 and 80°C, respectively. Xerogel matrix immobilization enhanced the catalytic efficiency of entrapped MnP. Metal ions including Cu2+, Mn2+ and Fe2+ stimulated enzyme activity while cysteine, EDTA and Ag+ inhibited the activity. MnP preserved 82% of its initial activity during oxidation of MnSO4 in 10 consecutive cycles, demonstrating the reusability of xerogel entrapped MnP. The immobilized MnP could be stored for up to 75 days at 4°C without significant activity loss. To explore the industrial applicability of MnP, the immobilized MnP was tested for decolorization of textile industry effluent in a Packed Bed Reactor System (PBRS). After five consecutive cycles, 98.8% decolorization of effluent was achieved within 5 h. The kinetic properties, storage stability and reusability of entrapped MnP from T. versicolor IBL-04 reflect its prospects as biocatalyst for bioremediation and other industrial applications.

  13. Two distinct halo populations in the solar neighborhood II. Evidence from stellar abundances of Mn, Cu, Zn, Y, and Ba

    DEFF Research Database (Denmark)

    Nissen, Poul Erik; Schuster, William J.

    2011-01-01

    .4 in the solar neighborhood has revealed the existence of two distinct halo populations with a systematic difference in [α/Fe] at a given metallicity. In continuation of that work, abundances of Mn, Cu, Zn, Y, and Ba are determined for the same sample of stars. Methods. Equivalent widths of atomic lines...... differences between the “high-α” and “low-α” halo populations are found for [Cu/Fe], [Zn/Fe], and [Ba/Y], whereas there is no significant difference in the case of [Mn/Fe]. At a given metallicity, [Cu/Fe] shows a large scatter that is closely correlated with a corresponding scatter in [Na/Fe] and [Ni....../Fe]. Conclusions. The metallicity trends of [Cu/Fe], [Zn/Fe], and [Ba/Y] can be explained from existing nucleosynthesis calculations if the high-α stars formed in regions with such a high star formation rate that only massive stars and type II supernovae contributed to the chemical enrichment. The low-α stars...

  14. Synthesis, characterisation and antimicrobial activity of copper(II) and manganese(II) complexes of coumarin-6,7-dioxyacetic acid (cdoaH2) and 4-methylcoumarin-6,7-dioxyacetic acid (4-MecdoaH2): X-ray crystal structures of [Cu(cdoa)(phen)2].8.8H(2)O and [Cu(4-Mecdoa)(phen)2].13H2O (phen=1,10-phenanthroline).

    Science.gov (United States)

    Creaven, Bernadette S; Egan, Denise A; Karcz, Dariusz; Kavanagh, Kevin; McCann, Malachy; Mahon, Mary; Noble, Andy; Thati, Bhumika; Walsh, Maureen

    2007-08-01

    Two novel coumarin-based ligands, coumarin-6,7-dioxyacetic acid (1) (cdoaH(2)) and 4-methylcoumarin-6,7-dioxyacetic acid (2) (4-MecdoaH(2)), were reacted with copper(II) and manganese(II) salts to give [Cu(cdoa)(H(2)O)(2)].1.5H(2)O (3), [Cu(4-Mecdoa)(H(2)O)(2)] (4), [Mn(cdoa)(H(2)O)(2)] (5) and [Mn(4-Mecdoa)(H(2)O)(2)].0.5H(2)O (6). The metal complexes, 3-6, were characterised by elemental analysis, IR and UV-Vis spectroscopy, and magnetic susceptibility measurements and were assigned a polymeric structure. 1 and 2 react with Cu(II) in the presence of excess 1,10-phenanthroline (phen) giving [Cu(cdoa)(phen)(2)].8.8H(2)O (7) and [Cu(4-Mecdoa)(phen)(2)].13H(2)O (8), respectively. The X-ray crystal structures of 7 and 8 confirmed trigonal bipyramidal geometries, with the metals bonded to the four nitrogen atoms of the two chelating phen molecules and to a single carboxylate oxygen of the dicarboxylate ligand. The complexes were screened for their antimicrobial activity against a number of microbial species, including methicillin-resistant Staphylococcus aureus (MRSA), Escherichia coli and Candida albicans. The metal-free ligands 1 and 2 were active against all of the microbes. Complexes 3-6 demonstrated no significant activity whilst the phen adducts 7 and 8 were active against MRSA (MIC(80)=12.1microM), E. coli (MIC(80)=14.9microM) and Patonea agglumerans (MIC(80)=12.6microM). Complex 7 also demonstrated anti-Candida activity (MIC(80)=22microM) comparable to that of the commercially available antifungal agent ketoconazole (MIC(80)=25microM).

  15. Symmetric interfacial reconstruction and magnetism in La0.7Ca0.3MnO3/YBa2Cu3O7/La0.7Ca0.3MnO3 heterostructures

    Energy Technology Data Exchange (ETDEWEB)

    Visani, C. [Universidad Complutense, Spain; Tornos, J. [Universidad Complutense, Spain; Nemes, Norbert [Universidad Complutense, Spain; Rocci, M. [Universidad Complutense, Spain; Leon, C. [Universidad Complutense, Spain; Santamaria, J. [Universidad Complutense, Spain; te Velthuis, G. E. [Argonne National Laboratory (ANL); Liu, Y. [Argonne National Laboratory (ANL); Hoffman, A. [Argonne National Laboratory (ANL); Freeland, J. W. [Argonne National Laboratory (ANL); Garcia-Hernandez, M [Instituto de Ciencia de Materiales de Madrid (ICMM); Fitzsimmons, M. R. [Los Alamos National Laboratory (LANL); Kirby, B. J. [Los Alamos National Laboratory (LANL); Varela del Arco, Maria [ORNL; Pennycook, Stephen J [ORNL

    2011-01-01

    We have analyzed the interface structure and composition of La{sub 0.7}Ca{sub 0.3}MnO{sub 3}/YBa{sub 2}Cu{sub 3}O{sub 7}/La{sub 0.7}Ca{sub 0.3}MnO{sub 3} trilayers by combined polarized neutron reflectometry, aberration-corrected microscopy, and atomic column resolution electron-energy-loss spectroscopy and x-ray absorption with polarization analysis. We find the same stacking sequence at both top and bottom cuprate interfaces. X-ray magnetic circular dichroism experiments show that both cuprate interfaces are magnetic with a magnetic moment induced in Cu atoms as expected from symmetric Mn-O-Cu superexchange paths. These results supply a solid footing for the applicability of recent theories explaining the interplay between magnetism and superconductivity in this system in terms of the induced Cu spin polarization at both interfaces.

  16. Manganese depresses rat heart muscle respiration

    Science.gov (United States)

    It has previously been reported that moderately high dietary manganese (Mn) in combination with marginal magnesium (Mg) resulted in ultrastructural damage to heart mitochondria. Manganese may replace Mg in biological functions, including the role of enzyme cofactor. Manganese may accumulate and subs...

  17. Magnetic susceptibility and ground-state zero-field splitting in high-spin mononuclear manganese(III) of inverted N-methylated porphyrin complexes: Mn(2-NCH3NCTPP)Br.

    Science.gov (United States)

    Hung, Sheng-Wei; Yang, Fuh-An; Chen, Jyh-Horung; Wang, Shin-Shin; Tung, Jo-Yu

    2008-08-18

    The crystal structures of diamagnetic dichloro(2-aza-2-methyl-5,10,15,20-tetraphenyl-21-carbaporphyrinato-N,N',N'')-tin(IV) methanol solvate [Sn(2-NCH 3NCTPP)Cl 2.2(0.2MeOH); 6.2(0.2MeOH)] and paramagnetic bromo(2-aza-2-methyl-5,10,15,20-tetraphenyl-21-carbaporphyrinato-N,N',N'')-manganese(III) [Mn(2-NCH 3NCTPP)Br; 5] were determined. The coordination sphere around Sn (4+) in 6.2(0.2MeOH) is described as six-coordinate octahedron ( OC-6) in which the apical site is occupied by two transoid Cl (-) ligands, whereas for the Mn (3+) ion in 5, it is a five-coordinate square pyramid ( SPY-5) in which the unidentate Br (-) ligand occupies the axial site. The g value of 9.19 (or 10.4) measured from the parallel polarization (or perpendicular polarization) of X-band EPR spectra at 4 K is consistent with a high spin mononuclear manganese(III) ( S = 2) in 5. The magnitude of axial ( D) and rhombic ( E) zero-field splitting (ZFS) for the mononuclear Mn(III) in 5 were determined approximately as -2.4 cm (-1) and -0.0013 cm (-1), respectively, by paramagnetic susceptibility measurements and conventional EPR spectroscopy. Owing to weak C(45)-H(45A)...Br(1) hydrogen bonds, the mononuclear Mn(III) neutral molecules of 5 are arranged in a one-dimensional network. A weak Mn(III)...Mn(III) ferromagnetic interaction ( J = 0.56 cm (-1)) operates via a [Mn(1)-C(2)-C(1)-N(4)-C(45)-H(45A)...Br(1)-Mn(1)] superexchange pathway in complex 5.

  18. Indirect mass determination for the neutron-deficient nuclides 44V, 48Mn, 52Co and 56Cu

    Science.gov (United States)

    Tu, X. L.; Litvinov, Yu. A.; Blaum, K.; Mei, B.; Sun, B. H.; Sun, Y.; Wang, M.; Xu, H. S.; Zhang, Y. H.

    2016-01-01

    Mass excess values for 44V, 52Co and 56Cu are derived indirectly using the mirror symmetry and known data from beta-delayed proton spectroscopy. The new mass excess obtained by using the energy conservation for 48Mn is - 29 303 (14) keV, which is an improvement by about an order of magnitude compared to the AME'12 value. Compared to previously known data, the new proton separation energy for 45Cr causes a ˜3.5 times smaller matter flow through the Casbnd Sc cycle during the rp-process. Obtained proton separation energies for 52Co and 56Cu are about 500 keV larger than the AME'12 values. If confirmed, this would affect photo disintegration rates of 52Co (γ, p)51Fe and 56Cu (γ, p)55Ni reactions during the rp-process in X-ray bursts.

  19. Low-temperature sintering method for NiCuZn ferrite and effect of Mn addition on electromagnetic properties

    Institute of Scientific and Technical Information of China (English)

    JU Dong-ying; BIAN Pei

    2006-01-01

    Low temperature sintering NiCuZn ferrite was employed at most cases due to its co-firability with Ag (below 960 ℃). The NiCuZn ferrite sintered body with high-strength and high-frequency magnetic properties was fabricated. Firstly,NiCuZn ferrite powder was synthesized under CO2 atmosphere at 500 ℃ from the mixed doxalate synthesized by liquid phase precipitation method. Then a small amount of boric acid (H3BO3) was added to the powder,and the NiCuZn ferrite powder compact was prepared with Newton press and CIP methods. Finally,NiCuZn ferrite sintered body was fabricated by sintering at 900 ℃ under CO2 atmosphere. The minimum sintering temperature (800 ℃) was determined by the study of high temperature shrinkage. By this method,NiCuZn ferrite sintered body with 0.5% (mass fraction) boric acid was obtained,which has the bending strength of 340 MPa. The effect of various Mn addition on electromagnetic properties were studied.

  20. Detoxification of azo dyes mediated by cell-free supernatant culture with manganese-dependent peroxidase activity: effect of Mn2+ concentration and H2O2 dose.

    Science.gov (United States)

    Contreras, Elsa; Urra, Johana; Vásquez, Carlos; Palma, Carolyn

    2012-01-01

    White-rot fungi (WRF) are capable of degrading complex organic compounds such as lignin, and the enzymes that enable these processes can be used for the detoxification of recalcitrant organopollutants. The aim of this study is to evaluate a system based on the use of an in vitro ligninolytic enzyme for the detoxification of recalcitrant dye pollutants. The dyes selected for investigation were the anionic and cationic commercial azo dyes, basic blue 41 (BB41), acid black 1 (AB1), and reactive black 5 (RB5). A supernatant, cell-free culture of WRF with manganese peroxidase activity was used to investigate its degradative capacity under various conditions, and concentrations of cofactors, H(2)O(2) and Mn(2+). The assays were carried out using a 2(2) experimental designs whose variables were concentration of Mn(2+) (33 and 1,000 μM) and semicontinuous dosage of the H(2)O(2) (0.02 and 0.10 μmol) added at a frequency of 0.2 min(-1). The response variables analyzed were the efficiency and the initial rate of the decolorization process. The dye concentrations considered ranged from 10 to 200 mg L(-1). AB1 and RB5 were decolorized over the entire interval of concentrations studied; reaching efficiencies between 15 and 95%. Decolorization of up to 100 mg L(-1), BB41 had less than 30% efficiency. The decay of the concentration of AB1 was interpreted by two-stage kinetics model, with the exception of the condition of 33 μM Mn(2+)-0.02 μmol of H(2)O(2) in which only one stage was observed. For all assays performed with 33 μM Mn(2+), the initial rate of the decolorization process was found to be dependent on the dosage of H(2)O(2). The results of this study can be applied to the development bioreactors for the degradation of recalcitrant pollutants from the textile industry and may be used as a model for expanding the use of extracellular enzyme supernatants in bioremediation. Copyright © 2011 American Institute of Chemical Engineers (AIChE).

  1. Dye-Sensitized Cu2 XSnS4 (X=Zn, Ni, Fe, Co, and Mn) Nanofibers for Efficient Photocatalytic Hydrogen Evolution.

    Science.gov (United States)

    Gonce, Mehmet Kerem; Aslan, Emre; Ozel, Faruk; Hatay Patir, Imren

    2016-03-21

    The photocatalytic hydrogen evolution activities of low-cost and noble-metal-free Cu2 XSnS4 (X=Zn, Ni, Fe, Co, and Mn) nanofiber catalysts have been investigated using triethanolamine as an electron donor and eosin Y as a photosensitizer under visible-light irradiation. The rates of hydrogen evolution by Cu2 XSnS4 (X=Zn, Ni, Fe, Co, and Mn) nanofibers have been compared with each other and with that of the noble metal Pt. The hydrogen evolution rates for the nanofibers change in the order Cu2 NiSnS4 >Cu2 FeSnS4 >Cu2 CoSnS4 >Cu2 ZnSnS4 >Cu2 MnSnS4 (2028, 1870, 1926, 1420, and 389 μmol g(-1) h(-1) , respectively). The differences between the hydrogen evolution rates of the nanofibers could be attributed to their energy levels. Moreover, Cu2 NiSnS4, Cu2 FeSnS4 , and Cu2 CoSnS4 nanofibers show higher and more stable photocatalytic hydrogen production rates than that of the noble metal Pt under long-term irradiation with visible light.

  2. Geochemical Characteristics of Sinian Manganese Deposits in China

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Sinian is one of the main periods of the formation of manganese deposits in China. Sinian manganese deposits are mainly hosted in carbon-rich black shale and siliceous shale formed during the Sinian interglacial period. The composition of manganese ore is simple. The main ore mineral is manganiferous carbonates. The grade of manganese ore is about 16- 25%, with Mn/Fe>5 and P/Mn=0.006- 0.14. Based on the tectonic setting and geological and geochemical characteristics of manganese deposits, this paper discusses the process of migration and concentration of manganese and ore-forming conditions of Sinian manganese deposits in China.

  3. Influence of copper, manganese and pH on the growth and several enzyme activities in mycorrhizal fungus Amanita muscaria.

    Science.gov (United States)

    Kong, E X

    1995-01-01

    The effects of various concentrations of copper, manganese and pH on the growth and several enzyme activities of mycorrhizal fungus Amanita muscaria were investigated. Cu (5-25 mg l-1) and lower pH (3.0-4.0) strongly inhibited the mycelial growth (dry weight), however, the protein content was not affected evidently. Some enzyme activities were lower as the Cu and Mn concentrations were higher and other enzymes had the maximum values at the specified concentration. The activities of the following enzymes were significantly correlated with the fungal growth after the treatment with Cu: G6PDH, MTLDH and trehalase, and with Mn: G6PDH, MTLDH and alpha-mannosidase respectively. Measurement of these enzyme activities might provide a useful biochemical criterion for the evaluation of the fungitoxicity of soil contaminated by copper or manganese.

  4. Abnormal dielectric behaviors in Mn-doped CaCu{sub 3}Ti{sub 4}O{sub 12} ceramics and their response mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Yuan-Hua, E-mail: linyh@tsinghua.edu.cn [State Key Laboratory of New Ceramics and Fine Processing, Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Deng, Wei [State Key Laboratory of New Ceramics and Fine Processing, Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Xu, Wei [Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Liu, Yong [State Key Laboratory of New Ceramics and Fine Processing, Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Chen, Dongliang; Zhang, Xiaoli [Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Nan, Ce-Wen [State Key Laboratory of New Ceramics and Fine Processing, Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China)

    2012-12-01

    Highlights: Black-Right-Pointing-Pointer Mn-doping affects the electric behaviors remarkably in CCTO ceramics. Black-Right-Pointing-Pointer The activation energy of grain and grain boundary disappears with increasing the Mn doping concentration. Black-Right-Pointing-Pointer The XANES spectra reveal that valence states of Ti, Mn and Cu in the grain and grain boundary changes greatly. - Abstract: Mn-doped CaCu{sub 3}Ti{sub 4}O{sub 12} (CCTO) polycrystalline ceramics have been prepared by the conventional solid state sintering. Our results indicate that 10% Mn doping can decrease the dielectric permittivity in CaCu{sub 3}Ti{sub 4}O{sub 12} by about 2 orders of magnitude (from 10{sup 4} to 10{sup 2}). The grain and grain boundary activation energies show an obvious increase from 0.054 eV to 0.256 eV, and decrease from 0.724 eV to 0.258 eV with increasing the Mn doping concentration, respectively, which may be caused by the variation of Cu and Ti valence states in the CCTO samples evidenced by the X-ray absorption spectra. The similar grain and grain boundary activation energies result in invalidation of the internal boundary layer capacitance effect for the 10% Mn-doped CCTO sample, and thus result in the dramatic decrease of dielectric permittivity.

  5. Properties of Manganese(III) Ferrocenyl-β-Diketonato Complexes Revealed by Charge Transfer and Multiplet Splitting in the Mn 2p and Fe 2p X-Ray Photoelectron Envelopes.

    Science.gov (United States)

    Buitendach, Blenerhassitt E; Erasmus, Elizabeth; Niemantsverdriet, J W Hans; Swarts, Jannie C

    2016-10-26

    A series of ferrocenyl-functionalized β-diketonato manganese(III) complexes, [Mn(FcCOCHCOR)₃] with R = CF₃, CH₃, Ph (phenyl) and Fc (ferrocenyl) was subjected to a systematic XPS study of the Mn 2p3/2 and Fe 2p3/2 core-level photoelectron lines and their satellite structures. A charge-transfer process from the β-diketonato ligand to the Mn(III) metal center is responsible for the prominent shake-up satellite peaks of the Mn 2p photoelectron lines and the shake-down satellite peaks of the Fe 2p photoelectron lines. Multiplet splitting simulations of the photoelectron lines of the Mn(III) center of [Mn(FcCOCHCOR)₃] resemble the calculated Mn 2p3/2 envelope of Mn(3+) ions well, indicating the Mn(III) centers are in the high spin state. XPS spectra of complexes with unsymmetrical β-diketonato ligands (i.e., R not Fc) were described with two sets of multiplet splitting peaks representing fac and the more stable mer isomers respectively. Stronger electron-donating ligands stabilize fac more than mer isomers. The sum of group electronegativities, ΣχR, of the β-diketonato pendant side groups influences the binding energies of the multiplet splitting and charge transfer peaks in both Mn and Fe 2p3/2 photoelectron lines, the ratio of satellite to main peak intensities, and the degree of covalence of the Mn-O bond.

  6. Phytoavailability and fractionation of copper, manganese, and zinc in soil following application of two composts to four crops

    Energy Technology Data Exchange (ETDEWEB)

    Zheljazkov, Valtcho D.; Warman, Phil R

    2004-09-01

    Two experiments were conducted to evaluate the effect of compost addition to soil on fractionation and bioavailability of Cu, Mn, and Zn to four crops. Soils growing Swiss chard (Beta vulgaris var. cicla L.) and basil (Ocimum basilicum L.) were amended (by volume) with 0, 20, 40, and 60% Source-Separated Municipal Solid Waste (SS-MSW) compost, and dill (Anethum graveolens L.) and peppermint (Mentha X piperita L.) were amended with 0, 20, 40, and 60% of high-Cu manure compost (by volume). The SS-MSW compost applications increased the concentration of Cu and Zn in all fractions, increased Mn in acid extractable (ACID), iron and manganese oxides (FeMnOX), and organic matter (OM) fractions, but decreased slightly exchangeable-Mn. Addition of 60% high-Cu manure compost to the soil increased Cu EXCH, ACID, FeMnOX, and OM fractions, but decreased EXCH-Mn, and did not change EXCH-Zn. Addition of both composts to soil reduced bioavailability and transfer factors for Cu and Zn. Our results suggest that mature SS-MSW and manure composts with excess Cu and Zn could be safely used as soil conditioners for agricultural crops.

  7. Synthesis and characterization of manganese-glycine and copper-glycine adducts

    Directory of Open Access Journals (Sweden)

    Robson Fernandes de Farias

    2002-09-01

    Full Text Available This work reports the synthesis and characterization of adducts of general formula MCl2.ngly, where M= Mn and Cu; n= 2 and 4, and gly= glycine. The manganese adducts were synthesized by dissolution of both, manganese chloride and glycine in water, whereas the copper adducts were obtained by using an alternative solid state synthesis approach. For all adducts, the obtained infrared data shows that the coordination involves the amine nitrogen atom, as well as an oxygen atom of the COO- group. The TG curves for the synthesized adducts exhibit only one mass loss step associated with the release of glycine molecules.

  8. Effect of copper doping on the crystal structure and morphology of 1D nanostructured manganese oxides.

    Science.gov (United States)

    Lee, Sun Hee; Park, Dae Hoon; Hwang, Seong-Ju; Choy, Jin-Ho

    2007-11-01

    We have tried to control the aspect ratio and physicochemical properties of 1D nanostructured manganese oxides through copper doping. Copper-doped manganese oxide nanostructures have been synthesized by one-pot hydrothermal treatment for the mixed solution of permanganate anions and copper cations. According to powder X-ray diffraction and electron microscopic analyses, all the present materials commonly crystallize with alpha-MnO2-type structure but their aspect ratio decreases significantly with increasing the content of copper. Such a variation of crystallite dimension is attributable to the limitation of crystal growth by the incorporation of copper ions. X-ray absorption spectroscopic studies at Mn K- and Cu K-edges clearly demonstrate that the average oxidation state of manganese ions is increased by the substitution of divalent copper ions. Electrochemical measurements reveal the improvement of the electrode performance of nanostructured manganate upon copper doping, which can be interpreted as a result of the decrease of aspect ratio and the increase of Mn valence state. From the present experimental findings, it becomes certain that the present Cu doping method can provide an effective way of controlling the crystal dimension and electrochemical property of 1D nanostructured manganese oxide.

  9. Selective oxidation of benzylic alcohols using copper-manganese mixed oxide nanoparticles as catalyst

    Directory of Open Access Journals (Sweden)

    Roushown Ali

    2015-07-01

    Full Text Available The catalytic activity of copper-manganese (CuMn2 mixed oxide nanoparticles (Cu/Mn = 1:2 has been studied for the selective oxidation of benzylic alcohols to the corresponding aldehydes using molecular oxygen as an oxidizing agent. The CuMn2 mixed oxide showed excellent catalytic activity for the oxidation of benzylic alcohols to the corresponding aldehydes with high selectivity (>99%. The complete conversion (100% of all the benzylic alcohols to the corresponding aldehydes is achieved within a short reaction period at 102 °C. The catalytic performance is obtained to be dependent on the electronic and steric effects of the substituents present on the phenyl ring. Electron withdrawing and bulky groups attached to the phenyl ring required longer reaction time for a complete conversion of the benzylic alcohols.

  10. Ferroportin is a manganese-responsive protein that decreases manganese cytotoxicity and accumulation

    National Research Council Canada - National Science Library

    Yin, Zhaobao; Jiang, Haiyan; Lee, Eun-Sook Y; Ni, Mingwei; Erikson, Keith M; Milatovic, Dejan; Bowman, Aaron B; Aschner, Michael

    2010-01-01

    Although manganese (Mn) is an essential trace element for human development and growth, chronic exposure to excessive Mn levels can result in psychiatric and motor disturbances, referred to as manganism...

  11. Effect of anions on removing Cu2+, Mn2+ and Zn2+ in electrocoagulation process using aluminum electrodes.

    Science.gov (United States)

    Hanay, Özge; Hasar, Halil

    2011-05-15

    In the present study, the performance of electrocoagulation process with aluminum electrodes in the treatment of Cu(2+), Zn(2+) and Mn(2+) containing aqueous solutions was investigated by depending on type of anion in solution, considering some operating conditions such as initial metal concentration and pH. Results obtained from synthetic wastewater showed that type of anion in solutions has a significant effect on the metal removal. The initial concentration of zinc influenced significantly the performance of electrocoagulation process as compared with the results obtained from Mn and Cu metals. Anions studied did not generate an important difference between pH variations. Best removals for three metals were achieved with increasing the pH in the presence of both anions. Total removals of copper and zinc reached almost 100% after 5 min at pH values > 7. At the end of the experiments for 35 min, the Mn removals were 85 and 80% in the presence of sulfate and chloride anions, respectively.

  12. Microstructure, thermodynamics and compressive properties of AlCoCrCuMn-x (x=Fe, Ti) high-entropy alloys

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Zhaoqin, E-mail: wzqpapers@126.com [School of Railway Technology, Lanzhou Jiaotong University, Lanzhou 730010 (China); Wang, Xiaorong [School of Mechatronic Engineering, Lanzhou Jiaotong University, Lanzhou 730010 (China); Yue, Hui [School of Railway Technology, Lanzhou Jiaotong University, Lanzhou 730010 (China); Shi, Guangtian; Wang, Shunhua [School of Mechatronic Engineering, Lanzhou Jiaotong University, Lanzhou 730010 (China)

    2015-03-11

    Two equiatomic high-entropy alloys (HEAs), AlCoCrCuMnFe and AlCoCrCuMnTi, were produced by vacuum arc melting. Their microstructure, thermodynamics and mechanical properties were investigated in as-cast condition. The AlCoCrCuMnFe alloy is comprised of a face centered cubic (FCC) phase and two body centered cubic (BCC) phases, while the AlCoCrCuMnTi alloy consists of the intermetallics-base solid solution (AlCu{sub 2}Mn-like phase) besides a FCC phase and two BCC phases. Through analyzing the thermodynamics of equiatomic multicomponent alloys, two parameters, k{sub n} and φ, were proposed. The parameter k{sub n} is a function of n (n – the number of the components in an alloy system), while φ is defined as a parameter of T{sub sum} over |H{sub sum}| (T{sub sum} – the sum of every elemental melting point in an alloy system, |H{sub sum}| – the sum of mixing enthalpies of different pairs of alloying elements). φ≥1.1/k{sub n} is equivalent to Ω≥1.1 proposed by Yang to predict high entropy stabilized solid solution in equiatomic multicomponent alloys and more convenient to calculate. Compressive properties of the two HEAs together with their hardness have been investigated. Comparing to AlCoCrCuMnFe alloy, AlCoCrCuMnTi alloy has higher Vickers hardness, yield strength and compressive strength, but lower ultimate strain.

  13. Cu{sub 1.5}Mn{sub 1.5}O{sub 4}-based ceramic spectrally selective coatings for efficient solar absorber applications

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Pengjun [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000 (China); University of Chinese Academy of Sciences, Beijing, 100049 (China); Geng, Qingfen; Gao, Xianghu [Research & Development Center for Eco-material and Eco-chemistry, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000 (China); Yang, Shengrong [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000 (China); Liu, Gang, E-mail: gangliu@licp.cas.cn [Research & Development Center for Eco-material and Eco-chemistry, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000 (China)

    2016-08-05

    Cu{sub 1.5}Mn{sub 1.5}O{sub 4}-based ceramic spectrally selective (CSS) coating was deposited on aluminum substrate using a sol–gel dip-coating method. The citric acid introduced in the precursor system lowered the required calcining temperature of crystalline Cu{sub 1.5}Mn{sub 1.5}O{sub 4}. X-Ray diffraction (XRD) peaks of coatings annealed above 450 °C were found to coincide exactly with that of crystalline Cu{sub 1.5}Mn{sub 1.5}O{sub 4} in JCPDS database. By optimizing the withdrawal rate and calcining temperature, coating with spectral selectivity as good as α{sub s} = 0.876 and ε{sub 100} = 0.057 was achieved after only one dipping/annealing cycle. Subjected to an accelerated ageing test at 259 °C, the obtained CSS coating showed an excellent thermally durability with the performance criterion (PC) values below 0.05. - Highlights: • Cu{sub 1.5}Mn{sub 1.5}O{sub 4}-based CSS coating is achieved after only one dipping/annealing cycle. • Cu{sub 1.5}Mn{sub 1.5}O{sub 4} coating is obtained as the annealing temperature reaches to 450 °C. • Cu{sub 1.5}Mn{sub 1.5}O{sub 4} coating exhibits optical parameter: α{sub s} = 0.876 and ε{sub 100} = 0.057. • Cu{sub 1.5}Mn{sub 1.5}O{sub 4} coating shows the excellent stability in low to mid temperature region.

  14. High-precision abundances of Sc, Mn, Cu, and Ba in solar twins. Trends of element ratios with stellar age

    Science.gov (United States)

    Nissen, P. E.

    2016-09-01

    Aims: A previous study of correlations between element abundances and ages of solar twin stars in the solar neighborhood is extended to include Sc, Mn, Cu, and Ba to obtain new information on the nucleosynthetic history of these elements. Methods: HARPS spectra with S/N ≳ 600 are used to derive very precise (σ ~ 0.01 dex) differential abundances of Sc, Mn, Cu, and Ba for 21 solar twins and the Sun. The analysis is based on MARCS model atmospheres with parameters determined from the excitation and ionization balance of Fe lines. Stellar ages with internal errors less than 1 Gyr are obtained by interpolation in the log g - Teff diagram between isochrones based on the Aarhus Stellar Evolution Code. Results: For stars younger than 6 Gyr, [Sc/Fe], [Mn/Fe], [Cu/Fe], and [Ba/Fe] are tightly correlated with stellar age, which is also the case for the other elements previously studied; linear relations between [X/Fe] and age have χ^2red ˜ 1, and for most stars the residuals do not depend on elemental condensation temperature. For ages between 6 and 9 Gyr, the [X/Fe] - age correlations break down and the stars split up into two groups having respectively high and low [X/Fe] for the odd-Z elements Na, Al, Sc, and Cu. Conclusions: While stars in the solar neighborhood younger than ~ 6 Gyr were formed from interstellar gas with a smooth chemical evolution, older stars seem to have originated from regions enriched by supernovae with different neutron excesses. Correlations between abundance ratios and stellar age suggest that: (i) Sc is made in Type II supernovae along with the α-capture elements; (ii) the Type II to Ia yield ratio is about the same for Mn and Fe; (iii) Cu is mainly made by the weak s-process in massive stars; (iv) the Ba/Y yield ratio for asymptotic giant branch stars increases with decreasing stellar mass; (v) [Y/Mg] and [Y/Al] can be used as chemical clocks when determining ages of solar metallicity stars. Based on data products from observations made

  15. The ground states properties and the spin effect on the cubic and hexagonal perovskite manganese oxide BaMnO 3: GGA+ U calculation

    Science.gov (United States)

    Hamdad, Noura

    2011-03-01

    Particularly interesting as candidates to technological applications are the manganese perovskites with AMnO 3 formula. Their magnetic structure was described as resulting from a particular ordering of the occupied d orbitals which possess. This reflects my understanding of the structural, electronic and magnetic phenomena, which is well established only in the limit where the systems show localized or itinerant electron behavior. In general, the perovskites of ABO 3-type are well known with their (anti)ferroelectric, piezoelectric and (anti)ferromagnetism properties applied in considerable technological investigations. In my paper, I studied the ground states properties of the BaMnO 3 perovskite oxide. My structural properties are given using LSDA, GGA, LSDA+ U and GGA+ U in the aim to introduce the exchange correlation potential. In the following paper, I use the GGA+ U on the electronic and magnetic properties calculation. I show in my study the density of states, the band structures and also the charge density figures. My results such as lattice parameter, bulk modulus and its pressure derivative agree very well with available theoretical works and experimental data. I discuss the magnetic moment and the U-Hubbard effect introduced by LSDA+ U and GGA+ U on my results given in this paper.

  16. A New Resource-Saving, High Chromium and Manganese Super Duplex Stainless Steels 29Cr-12Mn-2Ni-1Mo-xN

    Institute of Scientific and Technical Information of China (English)

    MA Zheng-huan; ZHAO Xiang-juan; GE Chang-sheng; DING Tie-suo; LI Jun; XIAO Xue-shan

    2011-01-01

    A new family of resource saving, high chromium and manganese super duplex stainless steels (DSSs), with a composition in mass percent, % of Cr 0.29, Mn 0.12, Ni 2.0, Mo i. 0, and N 0. 51-0. 68, has been developed by examining the effect of N on the microstructure, mechanical properties and corrosion properties. The results show that these alloys have a balanced ferrite-austenite relation. The austenite volume fraction decreases with the solution treatment temperature, but it increases with an increase in N content. The increases in nitrogen enhance the ultimate tensile strength (UTS) and reduce the ductility of the material slightly. The pitting corrosion potential increases first and then decreases with an increase in nitrogen content when the amount of N arrives to 0.68%. The yield stress and ultimate tensile strength of solution treated samples were more than 680 and 900 MPa, the elongation of experimental alloys are higher than 30%, respectively, what is more, the pitting potentials were beyond 1 100 mV.

  17. Manganese superoxide dismutase (SOD2/MnSOD)/catalase and SOD2/GPx1 ratios as biomarkers for tumor progression and metastasis in prostate, colon, and lung cancer.

    Science.gov (United States)

    Miar, Ana; Hevia, David; Muñoz-Cimadevilla, Henar; Astudillo, Aurora; Velasco, Julio; Sainz, Rosa M; Mayo, Juan C

    2015-08-01

    The role of manganese-dependent superoxide dismutase (SOD2/MnSOD) during tumor progression has been studied for several decades with controversial results. While SOD2 downregulation was initially associated with tumor initiation and was proposed as a tumor suppressor gene, recent studies have reported that SOD2 might favor tumor progression and dissemination. To our knowledge this is the first time that changes in SOD2 expression in three different types of tumors, i.e., prostate, lung, and colon cancer, are studied by analyzing both SOD2 mRNA and protein levels in a total of 246 patients' samples. In prostate samples, SOD2 protein levels were also increased, especially in middle stage tumors. In the case of colon and lung tumors both mRNA and protein SOD2 levels were increased in malignant tissues compared to those in nontumor samples. More importantly, all metastases analyzed showed increased levels of SOD2 when compared to those of normal primary tissue and healthy adjacent tissue. Together, these results suggest that a common redox imbalance in these three types of tumor occurs at intermediate stages which then might favor migration and invasion, leading to a more aggressive cancer type. Consequently, the ratios SOD2/catalase and SOD2/Gpx1 could be considered as potential markers during progression from tumor growth to metastasis.

  18. Effect of austenization temperature on the microstructure evolution of the medium manganese steel (0.2C-5Mn) during ART-annealing

    Institute of Scientific and Technical Information of China (English)

    Jie SHI; Haifeng XU; Jie ZHAO; Wenquan CAO; Chang WANG; Cunyu WANG; Jian LI; Han DONG

    2012-01-01

    Microstructure evolution during ART-annealing (austenite reverted transformation annealing) of 0.2C-5Mn steel processed by austenitation at different temperatures was examined by SEM,TEM and XRD.It was demonstrated that the initial microstructures resulted from austenization at different temperatures strongly affect the microstructure evolution during followed ART-annealing,even the ultrafine grained ferrite/austenite duplex structure with about 30% austenite could be obtained after long time ART-annealing in all cases.Austenization in the intercritical region (between Ac1 and Ac3) gave a duplex structure after quenching,which was nearly not affected by followed annealing process.However,high temperature anstenization (above Ac3) resulted in a full martensite structure after quenching,which gradually transformed into a ferrite/austenite duplex structure during the following annealing process. Based on the analysis of austenite fraction and carbon concentrate,it was found that not only carbon partitioning but also manganese partitioning in the austenite affected the stability of austenite and even dominated the development of lamellar ferrite and austenite duplex structure during intercritical annealing with different times.At last an austenite lath nucleation and thickening model was proposed to describe the microstructure evolution of medium mangenese steel during ART-annealing.

  19. Heat treatment effects on the microstructure and mechanical properties of a medium manganese steel (0.2C-5Mn)

    Energy Technology Data Exchange (ETDEWEB)

    Xu, H.F., E-mail: xuhaifeng228@163.com [School of Materials Science and Engineering, State Key Laboratory of Material Processing and Die and Mould Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074 (China) and National Engineering Research Center of Advanced Steel Technology NERCAST, Central Iron and Steel Research Institute CISRI, Beijing 100081 (China); Zhao, J. [School of Materials Science and Engineering, State Key Laboratory of Material Processing and Die and Mould Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074 (China); National Engineering Research Center of Advanced Steel Technology (NERCAST), Central Iron and Steel Research Institute (CISRI), Beijing 100081 (China); Cao, W.Q.; Shi, J.; Wang, C.Y.; Wang, C. [National Engineering Research Center of Advanced Steel Technology NERCAST, Central Iron and Steel Research Institute (CISRI), Beijing 100081 (China); Li, J. [School of Materials Science and Engineering, State Key Laboratory of Material Processing and Die and Mould Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074 (China); Dong, H. [National Engineering Research Center of Advanced Steel Technology NERCAST, Central Iron and Steel Research Institute (CISRI), Beijing 100081 (China)

    2012-01-15

    Highlights: Black-Right-Pointing-Pointer Substantially improved mechanical properties of 0.2C-5Mn steels. Black-Right-Pointing-Pointer Intercritical austenization followed by short time annealing. Black-Right-Pointing-Pointer Phase transformation induced plasticity of the large volume fractioned austenite. Black-Right-Pointing-Pointer Dependence of yield stress on austenite grain size accords with Hall-Petch equation. - Abstract: Microstructures and mechanical properties of 0.2C-5Mn steel processed under different heat treatment conditions were examined by scanning electron microscopy (SEM), Transmission electron microscopy (TEM) and X-ray diffraction (XRD). It was found that high temperature austenization (above Ac3) resulted in a full martensite structure after quenching, which gradually transformed into the ferrite/austenite duplex structure during the following annealing process. However, austenization in the intercritical region (between Ac1 and Ac3) gave a duplex structure after quenching, which was nearly not affected by followed annealing process. The ultrahigh strength {approx}1000 MPa and total elongation {approx}40% were only obtained in the specimens with 6 h annealing at 650 Degree-Sign C under both heat treatment conditions. However, the excellent mechanical properties could be obtained in the intercritically austenitized samples with only 10 min annealing at 650 Degree-Sign C. Based on the analysis on the relationship between microstructure and mechanical properties, it was found that the total elongation was strongly dependent on the austenite fraction, which was ascribed to the phase transformation induced plasticity of the large volume fraction of austenite. Otherwise, the dependence of the yield stress on the austenite grain size accords with Hall-Petch equation, which implies that the austenite is soft phase. It was concluded that 10 min annealing at 650 Degree-Sign C was enough to obtain a large volume fraction of austenite ({approx}30%) in 0

  20. Microstructure and mechanical properties of spray-deposited Al-Si-Fe-Cu-Mg alloy containing Mn

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Al-20Si-5Fe-3Cu-lMg alloy was synthesized by the spray atomization and deposition technique. The microstructure and mechanical properties of the spray deposited hypereutectic Al-Si alloy were studied using optical microscopy, scanning electron microscopy, X-ray diffraction, TEM (Transmission Electron Microscope) and HREM (High-resolution Electron Microscope), DSC (Differential Scanning Calorimetry), microhardness measurement, and tensile tests. The effects of Mn on the microstructural evolution of the highsilicon aluminum alloy after extrusion and heat treatment have been examined. The results show that two kinds of phases, i.e. S (Al2CuMg) and σ(Al5Cu6Mg2), precipitated from matrix and improved the tensile strength of the alloy efficiently at both the ambient and elevated temperatures (300℃). The tensile test results indicate that the spray-deposited Al-20Si-SFe-3Cu-1Mg alloy has better strength than the powder metallurgy processed Al-20Si-3Cu-1Mg alloy at elevated temperature.

  1. Processing of CuAlMn Shape Memory Foams with Open Spherical Pores by Silica-Gel Beads Infiltration Method

    Science.gov (United States)

    Li, Hua; Yuan, Bin; Gao, Yan

    2016-10-01

    A molten metal infiltration process with amorphous SiO2 (silica-gel) beads as space holders was used to prepare Cu-based shape memory foams in this article. We found that the silica-gel beads with micropores inside expanded when being heated to elevated temperatures and that proper control of the expansion of silica-gel beads helped form necks between the beads with different bonding extent, which had been taken advantage of to have a good control of the foam morphology and porosity, by carefully designing suitable procedures and choosing proper parameters for the process. In addition, we studied in detail the effect of heating temperature, silica-gel bead density, and infiltration pressure of the present process on the morphology and porosity of CuAlMn shape memory foams. By coordinating these three key parameters, CuAlMn shape memory foams with open spherical pores and adjustable porosity from 66 to 85 pct were reliably produced.

  2. COMPARISON OF DIFFERENT EXTRACTION METHODS REPRESENTING AVAILABLE AND TOTAL CONCENTRATIONS OF Cd, Cu, Fe, Mn and Zn IN SOIL

    Directory of Open Access Journals (Sweden)

    Vladimir Ivezić

    2013-06-01

    Full Text Available Various extraction methods are used to predict plant uptake of trace metals. Most commonly it is total concentration that is used for risk assessment and evaluation of trace metal availability. However, recent studies showed that total concentration is a poor indicator of availability while concentrations in soil solution show good correlation with plant uptake. Present study was conducted on magricultural soils with low levels of trace metals where 45 soil samples were collected from different soil types. The main objective was to compare four different extraction methods and examine how total and reactive (EDTA trace metal concentrations correlate ,with soil solution concentration (in this study determined by water extraction. The samples were analyzed by four extraction methods: strong acid extraction (ultra-pure HNO3 extraction and aqua regia, weak acid extraction by EDTA and the most available fraction, fraction in soil solution, were represented by water extraction (weakest extractant. Five elements were investigated (Cd, Cu, Fe, Mn and Zn. Water extraction significantly correlated with EDTA extraction for Cu, Fe and Mn, while total extraction (HNO3 extraction and aqua regia correlated significantly with water extraction only for Cu. No correlation between water extraction and total extraction confirmed poor role of total concentration as an indicator of availability. EDTA extraction can be used to represent reactive pool of trace metals in soil but it should be also taken with caution when using it to describe available fraction.

  3. Designed synthesis of MOx (M = Zn, Fe, Sn, Ni, Mn, Co, Ce, Mg, Ag), Pt, and Au nanoparticles supported on hierarchical CuO hollow structures.

    Science.gov (United States)

    Zhang, Zailei; Jung, Ji Chul; Yan, Ning

    2016-12-01

    Despite intensive research into support substrates for the dispersal of nanoparticles and their applications, there has been a lack of general methods to produce metal oxide hollow substrates supporting a wide range of metal and metal oxides. Herein, a synthetic protocol for the preparation of CuO hollow structure-supported MOx (M = Zn, Fe, Ni, Sn, Mn, Co, Ce, Mg, and Ag) and noble metals (Pt and Au) with the desired properties and shell structure, such as CuO/Fe2O3, CuO/ZnO, CuO/SnO2, CuO/MgO, CuO/NiO, CuO/Mn2O3, CuO/CoO, CuO/CeO2, CuO/Ag2O, CuO/Pt, CuO/Au hollow cubes, CuO/ZnO double-shell hollow cubes, CuO/SnO2 double-shell hollow octahedra, CuO/SnO2/Fe2O3 and CuO/Mn2O3/NiO double-shell hollow cubes, was developed based on controlled calcination and etching. These hybrid hollow structures were employed not only as support substrates but also as active constituents for catalytic reactions. As an example, we demonstrated that CuO/ZnO hollow cubes are remarkably efficient in converting solid chitin biomass to liquid chemicals in methanol. In addition, CuO/ZnO double-shell hollow cubes were highly effective in the oxidation of benzyl alcohol in the presence of H2O2, whereas CuO/Pt and CuO/Au hollow cubes promoted the oxidation of benzyl alcohol in pure O2. The strategy developed in this work extends the controllable fabrication of high-quality CuO hollow structure-supported nanoparticles using various compositions and shell structures, paving the way to the exploration and systematic comparison of these materials in a wider range of applications.

  4. Influence of manganese on yielding of tomato (Lycopersicon esculentum Mill. cultivated in rockwool

    Directory of Open Access Journals (Sweden)

    Tomasz Kleiber

    2014-06-01

    Full Text Available The aim of the conducted studies was to determine the effect of different concentrations of manganese in nutrient solution on yielding of tomato (Lycopersicon esculentum Mill. cvs. ‘Alboney F1’ and ‘Emotion F1’ for optimization of the nutrition (experiment I and to determine the threshold of tolerance of plants on the mentioned nutrient (experiment II. Plants were grown in rockwool using a nutrient solution with the differentiated contents of manganese (mg·dm-3: experiment I, 2008-2011 – control (0.06, 0.3, 0.6, 1.2 (described as Mn-0, Mn-0.3, Mn-0.6, Mn-1.2, experiment II, 2012 – 2.4, 4.8, 9.6, 19.2 (described as Mn-2.4, Mn-4.8, Mn-9.6, Mn-19.2. For plant fertigation was used standard nutrient solution with the following chemical composition (mg·dm-3: N-NH4 – 2.2, N-NO3 – 230, P – 50, K – 430, Ca – 145, Mg – 65, Cl – 35, S-SO4 – 120, Fe – 2.48, Zn – 0.50, Cu – 0.07. pH value was 5.50, and EC – 3.00 mS·cm-1. The earliest symptoms of manganese poisoning plants were observed in case of Mn-19.2 – a month and a half after the beginning of the cultivation, and in the case of Mn-9.6 – after 2.5 months of exposure to the nutrient solution. Initial signs of plants poisoning applying manganese Mn-4.8 were observed after a 3-month use of the nutrient solution. To the level of Mn-1.2 there was a significant effect of manganese on the tomatoes yield of class I, III, IV and VI. The variety affected the average yield of class I and V, only. The highest marketable fruit yield of ‘Alboney F1’ was obtained using nutrient solutions with manganese content of 0.3 and 0.6 mg·dm-3. In the case of ‘Emotion F1’ the yield by using Mn-0 and Mn-0.3 was significantly lower than in the case of Mn-0.6. In the application of the nutrient solution containing 1.2 mg Mn per 1 dm3 significant reducing of yielding was found while the plants were not observed for symptoms resulting from excessive manganese nutrition. In range of

  5. Manganese in silicon carbide

    Science.gov (United States)

    Linnarsson, M. K.; Hallén, A.

    2012-02-01

    Structural disorder and relocation of implanted Mn in semi-insulating 4H-SiC has been studied. Subsequent heat treatment of Mn implanted samples has been performed in the temperature range 1400-2000 °C. The depth distribution of manganese is recorded by secondary ion mass spectrometry. Rutherford backscattering spectrometry has been employed for characterization of crystal disorder. Ocular inspection of color changes of heat-treated samples indicates that a large portion of the damage has been annealed. However, Rutherford backscattering shows that after heat treatment, most disorder from the implantation remains. Less disorder is observed in the [0 0 0 1] channel direction compared to [ 1 1 2¯ 3] channel direction. A substantial rearrangement of manganese is observed in the implanted region. No pronounced manganese diffusion deeper into the sample is recorded.

  6. Manganese in silicon carbide

    Energy Technology Data Exchange (ETDEWEB)

    Linnarsson, M.K., E-mail: marga@kth.se [Royal Institute of Technology, School of Information and Communication Technology, P.O. Box E229, SE-16440 Kista-Stockhom (Sweden); Hallen, A. [Royal Institute of Technology, School of Information and Communication Technology, P.O. Box E229, SE-16440 Kista-Stockhom (Sweden)

    2012-02-15

    Structural disorder and relocation of implanted Mn in semi-insulating 4H-SiC has been studied. Subsequent heat treatment of Mn implanted samples has been performed in the temperature range 1400-2000 Degree-Sign C. The depth distribution of manganese is recorded by secondary ion mass spectrometry. Rutherford backscattering spectrometry has been employed for characterization of crystal disorder. Ocular inspection of color changes of heat-treated samples indicates that a large portion of the damage has been annealed. However, Rutherford backscattering shows that after heat treatment, most disorder from the implantation remains. Less disorder is observed in the [0 0 0 1] channel direction compared to [112{sup Macron }3] channel direction. A substantial rearrangement of manganese is observed in the implanted region. No pronounced manganese diffusion deeper into the sample is recorded.

  7. Structure and Properties of Cast Near-Congruent Copper-Manganese Alloys

    Science.gov (United States)

    Chaput, Kevin; Trumble, Kevin P.

    2014-10-01

    Microstructure development in the casting of copper-manganese alloys based on the congruent point at 34.6 wt pct Mn and 1146 K (873 °C) has been studied. The alloys were prepared by induction melting of electrolytic Cu and Mn in clay-graphite crucibles in open air. Under conventional casting conditions, the alloys exhibit fine cellular (non-dendritic) solidification morphology with a distinct absence of solidification shrinkage microporosity, and they maintain these attributes over a composition range of approximately 3 wt pct Mn about the congruent point. The high Mn concentration in the alloy admits carbon into solution in the melt, resulting in formation of manganese carbide Mn7C3 particles having two different forms (globular and angular) in the cast microstructure. The Mn carbide was eliminated or controlled to low levels by melting in an alumina or a silicon carbide crucible, or in a clay-graphite crucible at lower temperatures. Microstructure development in casting the alloy was analyzed in terms of the available phase diagrams and thermochemical data. Hardness and tensile testing indicated a potent solid solution strengthening effect of Mn and high ductility in the as-cast condition, with additional hardness (strength) when the alloy contains the Mn carbide phase.

  8. An investigation of cellular distribution of manganese in hyperaccumlator plant Phytolacca acinosa Roxb. using SRXRF analysis

    Institute of Scientific and Technical Information of China (English)

    XU Xiang-hua; SHI Ji-yan; CHEN Ying-xu; XUE Sheng-guo; WU Bei; HUANG Yu-ying

    2006-01-01

    Phytolacca acinosa Roxb. (P. acinosa) is a recently discovered manganese hyperaccumulator plant from southern China. It is a good candidate for phytoremediation of manganese(Mn) polluted soil for its high biomass and fast growth. Knowledge of the tissue localization and identification of heavy metals can provide essential information on metal toxicity and bioaccumulation mechanisms. Synchrotron radiation X-ray fluorescence spectroscopy (SRXRF) microprobe was used in this study to investigate the cellular distributions of Mn and other elements in root, stem, leaf, petiole and midrib ofP. acinosa. The highest Mn content was found in the vascular tissues of root, stem, petiole and midrib. Cortex in root played a key role in Mn absorption and Mn was limited in the vascular bundle during the process of transportation in stem. Moreover, Mn content in leaf epidermis was higher than that in mesophyll, which suggested that the sequestration of Mn in leaf epidermis might be one of the detoxification mechanisms of P.acinosa. The significance of other elemental (such as P, S, K, Ca, Fe, Zn and Cu) distribution patterns and the correlation with Mn were also discussed.

  9. Nature of electron correlation and hybridization in NixCu1−xMnSb Heusler alloys

    Directory of Open Access Journals (Sweden)

    I. Sarkar

    2016-08-01

    Full Text Available The electronic structure of Heusler alloys having mixed magnetic phases, comprising of vicinal anti-ferromagnetic and ferromagnetic orders, is of great significance. We present the results of an electronic structure study on NixCu1−xMnSb Heusler alloys, using Mn-2p core-level photoemission spectroscopy. Room temperature data in the paramagnetic phase reveal a non-monotonic variation of both electron correlation strength and conduction-band hybridization such that the former enhances while the latter weakens for compositions showing a mixed phase relative to compositions at the phase boundaries to the ordered phases. The results suggest a possible electronic driving force for settling mixed-magnetic phases.

  10. Effect of SO2 on selective catalytic reduction of NO over Mn-Cu-Ce/TiO2 at low temperature%SO2 对Mn-Cu-Ce/TiO2 低温选择催化还原NO的影响

    Institute of Scientific and Technical Information of China (English)

    伍斌; 黄妍; 郑毅; 童志权

    2008-01-01

    研究了SO2对Mn-Cu-Ce/TiO2选择催化还原 NO 的影响,并采用傅立叶变换红外光谱、x射线衍射光谱及暂态响应技术对Mn-Cu-Ce/TiO2催化剂的SO2中毒机理进行了探讨.结果表明,SO2 可强吸附在Mn-Cu-Ce/TiO2表面的 CuO 活性位上.并生成 CuSO4,由于 CuSO4 在低温时对SCR 反应有抑制作用,因而,催化剂的活性下降;暂态响应实验结果表明,Mn-Cu-Ce/TiO2催化剂上的SCR反应主要遵循 Langmuir-Hinshelwood机理.通过对催化剂进行硫酸化或 NO 预吸附,可以消除SO2对 Mn-Cu-Ce/TiO2的毒害作用.

  11. Preparation of Mn3O4 from manganese sulfate by solid-state ball milling reaction at room temperature%硫酸锰室温固相球磨制备四氧化三锰

    Institute of Scientific and Technical Information of China (English)

    马玉文; 冯雅丽; 李浩然

    2013-01-01

    利用软锰矿吸收硫酸镁热解尾气二氧化硫制得硫酸锰,再与碳酸氢铵室温下固相球磨反应,制备出前躯体碳酸锰,经热分解获得四氧化三锰.分别考察了物料比、球磨时间、球料比等因素对硫酸锰转化率的影响,采用XRD对产物进行了分析.结果表明,在n(碳酸氢铵)∶n(硫酸锰)=3.5∶1、球磨时间为40 min、球料质量比为5∶1时,硫酸锰的转化率可达99.8%,将固相产物在1 000℃热解1h后所制备的四氧化三锰纯度为99.9%.该工艺操作简单,产品纯度高,成本低,为硫酸锰制备四氧化三锰提供了新的途径.%Manganese sulfate was prepared by reaction between pyrolusite and sulfur oxide from the pyrolysis of magnesium sulfate.Mn3O4 can be prepared by pyrolysing the precursor MnCO3.The precursor was synthesized by solid-state ball milling reaction between NH4HCO3 and MnSO4 · H2O at room temperature.Effects of materials mix ratio, milling time, and ball-feed mass ratio on the conversion of manganese sulfate were investigated respectively.The products were analyzed by XRD.Results showed that the conversion rate of MnSO4 · H2O could reach 99.8% under the conditions of mix ratio 3.5:1 (amount-of-substance ratio of NH4HCO3 to MnSO4 · H2O),milling time 40 min, and ball-feed mass ratio 5:1 .The Mn3O4, whose purity was 99.9%, can be prepared by pyrolysing manganese carbonate at 1 000℃ for 1 h.The process has the advantages of simple in operation, high product purity, and low cost, and it can provide a new route for the preparation Mn3O4 from MnSO4 · H2O.

  12. Indicator and probability kriging methods for delineating Cu, Fe, and Mn contamination in groundwater of Najafgarh Block, Delhi, India.

    Science.gov (United States)

    Adhikary, Partha Pratim; Dash, Ch Jyotiprava; Bej, Renukabala; Chandrasekharan, H

    2011-05-01

    Two non-parametric kriging methods such as indicator kriging and probability kriging were compared and used to estimate the probability of concentrations of Cu, Fe, and Mn higher than a threshold value in groundwater. In indicator kriging, experimental semivariogram values were fitted well in spherical model for Fe and Mn. Exponential model was found to be best for all the metals in probability kriging and for Cu in indicator kriging. The probability maps of all the metals exhibited an increasing risk of pollution over the entire study area. Probability kriging estimator incorporates the information about order relations which the indicator kriging does not, has improved the accuracy of estimating the probability of metal concentrations in groundwater being higher than a threshold value. Evaluation of these two spatial interpolation methods through mean error (ME), mean square error (MSE), kriged reduced mean error (KRME), and kriged reduced mean square error (KRMSE) showed 3.52% better performance of probability kriging over indicator kriging. The combined result of these two kriging method indicated that on an average 26.34%, 65.36%, and 99.55% area for Cu, Fe, and Mn, respectively, are coming under the risk zone with probability of exceedance from a cutoff value is 0.6 or more. The groundwater quality map pictorially represents groundwater zones as "desirable" or "undesirable" for drinking. Thus the geostatistical approach is very much helpful for the planners and decision makers to devise policy guidelines for efficient management of the groundwater resources so as to enhance groundwater recharge and minimize the pollution level.

  13. Charge defects and highly enhanced multiferroic properties in Mn and Cu co-doped BiFeO{sub 3} thin films

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Guohua; Tan, Guoqiang, E-mail: tan3114@163.com; Luo, Yangyang; Liu, Wenlong; Xia, Ao; Ren, Huijun

    2014-06-01

    Pure BiFeO{sub 3} (BFO) and Mn, Cu co-doped BiFeO{sub 3} (BFMCO) thin films were deposited on fluorine doped tin oxide (FTO) substrates by a chemical solution deposition method. Detailed investigations were made on the effects of Mn and Cu co-doping on the crystal structure, the defect chemistry, multiferroic properties of the BFO thin films. With the co-doping of Mn and Cu, a structural transition from the rhombohedral (R3c:H) to the biphasic structure (R3c:H + P1) is confirmed by XRD, Rietveld refinement and Raman analysis. X-ray photoelectron spectroscopy (XPS) analysis shows that the coexistence of Fe{sup 2+}/Fe{sup 3+} and Mn{sup 2+}/Mn{sup 3+} ions in the co-doping films are demonstrated. Meanwhile, the way of the co-doping at B-sits is conducive to suppress Fe valence state of volatility and to decrease oxygen vacancies and leakage current. It's worth noting that the co-doping can induce the superior ferroelectric properties (a huge remanent polarization, 2P{sub r} ∼ 220 μC/cm{sup 2} and a relatively low coercive field, 2E{sub c} ∼ 614 kV/cm). The introduction of Mn{sup 2+} and Cu{sup 2+} ions optimizes the magnetic properties of BFO thin films by the biphasic structure and the destruction of spin cycloid.

  14. Thermodynamic Behavior of Manganese and Phosphorus between Liquid Iron and CaO-MgO-SiO2-Al2O3-FetO-MnO-P2O5 Slags

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The thermodynamic behavior of manganese and phosphorus betwe en liquid iron and CaO-MgO-SiO2-Al2O3-FetO-MnO-P2O5 ladle slag system was addressed by investigating the thermodynamic equilibria between li quid iron containing Mn and P and the ladle slag at 1873K. The Mn dist ribution ratio LMn increases with increasing FetO content and decreasi ng the basicity ((%CaO + %MgO)/ +%Al2O3+%P2O5)) in slag, while the P d istribution ratio LP seems to be increased as FetO content and the bas icity increases. The values of LMn and LP decrease by the addition of Al2O3 into slag. The expression of the dependence of LMn and LP on the basicity and content in slag was obtained.

  15. Synthesis and Magnetic Studies of Copper ( Ⅱ )-Manganese (Ⅱ)Heterobinuclear Complexes with an Oxamido Bridge

    Institute of Scientific and Technical Information of China (English)

    LI, Yan-Tuan; YAN, Cui-Wei; LIAO, Dai-Zheng

    2001-01-01

    Four new copper ( Ⅱ )-manganese ( Ⅱ ) beterobinuclear complexes bridged by N, N' -bis[ 2- (dimethylamino) ethyl) ] oxamido dianion (dmoxae) and end-capped with 1,10-phenanthroline (phen), 5-methyl-1, l0-phenanthroline (Mephen), diaminoethane (en) or 1,3-di-aminopropane (pn), respectively, namely, [Cu(dmoxae)MnL2](CO4)2 (L= phen, Mephen, en, pn), have been synthesized and characterized by elemental analyses, IR, electronic spectral studies, and molar conductivity measurements. The electronic reflectance spectrum indicates the presence of spin exchange-coupling interaction between bridged copper (Ⅱ) and manganese (Ⅱ) ions.The cryomagnetic measurements (4.2-300 K) of [ Cu(dmoxae)Mn(phen)2](ClO4)2 ( 1 ) and [Cu(dmoxae)Mn(Mephen)2](ClO4)2(2) complexes demonstrated an antiferromagnetic interaction between the adjacent manganese(Ⅱ) and copper (Ⅱ) ions through the oxamido-bridge within each molecule. On the basis of spin Hamiltonian, H^ = - 2JS^1·S^2,the magnetic analysis was carried out for the two complexes and the spin-coupling constant (J) was evaluated as - 35.9cm-1 for 1 and - 32.6 cm-1 for 2. The influence of methyl substitutions in the amine groups of the bridging ligand on magnetic interactions between the metal ions of this kind of complexes is also discussed.

  16. Dimethyl ether synthesis via methanol and syngas over rare earth metals modified zeolite Y and dual Cu-Mn-Zn catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Dingfeng Jin; Bing Zhu; Zhaoyin Hou; Jinhua Fei; Hui Lou; Xiaoming Zheng [Zhejiang University, Hangzhou (China). Institute of Catalysis, Department of Chemistry

    2007-12-15

    A series of zeolite Y modified with La, Ce, Pr, Nd, Sm and Eu were prepared via ion-exchange, and characterized by XRD, FT-IR and NH{sub 3}-TPD. It was found that these rare earth metals were encapsulated in the supercage of zeolite Y and resulted in its enhanced acidity. Among them, La-, Ce-, Pr- and Nd-modified zeolite Y exhibited higher activity and stability (than pure HY) for methanol dehydration to dimethyl ether (DME). For DME synthesis directly from CO hydrogenation using the dual Cu-Mn-Zn/modified-Y catalysts, it was found that Cu-Mn-Zn/La-Y and Cu-Mn-Zn/Ce-Y were more active than Cu-Mn-Zn/pure-HY. The conversion of CO on Cu-Mn-Zn/Ce-HY achieved 77.1% in an isothermal fixed bed reactor at 245{sup o}C, 2.0 MPa, H{sub 2}/CO = 3/2 and 1500 h{sup -1}. 36 refs., 7 figs., 3 tabs.

  17. Biological leaching of Mn, Al, Zn, Cu and Ti in an anaerobic sewage sludge effectuated by Thiobacillus ferrooxidans and its effect on metal partitioning.

    Science.gov (United States)

    Lombardi, Ana T; Garcia, Oswaldo

    2002-07-01

    The chemical fractionation and bioleaching of Mn, Al, Zn, Cu and Ti in municipal sewage sludge were investigated using Thiobacillus ferrooxidans as leaching microorganism. As a result of the bacterial activity, ORP increase and pH reduction were observed. Metal solubilization was accomplished only in experimental systems supplemented with energy source (Fe(II)). The solubilization efficiency approached approximately 80% for Mn and Zn, 24% for Cu, 10% for Al and 0.2% for Ti. The chemical fractionation of Mn, Al, Zn, Cu and Ti was investigated using a five-step sequential extraction procedure employing KNO3, KF, Na4P2O7, EDTA and HNO3. The results show that the bioleaching process affected the partitioning of Mn and Zn, increasing its percentage of elution in the KNO3 fraction while reducing it in the KF, Na4P2O7 and EDTA fractions. No significant effect was detected on the partitioning of Cu and Al. However, quantitatively the metals Mn, Zn, Cu and Al were extracted with higher efficiency after the bacterial activity. Titanium was unaffected by the bioleaching process in both qualitative and quantitative aspects.

  18. Synthesis and Study of Optical properties of MgO based TM oxide (TM=Cu, Mn and Zn) nanocomposites

    Science.gov (United States)

    Tamizh Selvi, K.; Alamelumangai, K.; Priya, M.; Rathnakumari, M.; Kumar, P. Suresh; Sagadevan, Suresh

    2016-11-01

    A nanocomposite of MgO based transition metal (TM) oxide (TM=Zn, Mn, and Cu) was synthesized using sol-gel method. The powder x-ray diffraction confirmed the phase purity and particle size. The surface morphology and elemental composition were examined by High resolution scanning electron microscopy and energy-dispersive x-ray spectroscopy. The change in optical band gap of the synthesized nanocomposites, by increasing the Mg content was determined using UV-vis spectra and the luminescent properties were analyzed using photoluminescence spectra.

  19. Kinetic equations characterizing double reversible transformations in heating CuZnAlMnNi shape memory alloy

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The apparent activation energies and frequency factors of the double reversible transformations occurring in heating CuZnAlMnNi shape memory alloy (SMA) were deduced as AEx .M = 62.597 8 kJ/mol, AEm.A 153.92 kJ'mol,Ax-m = 5.223 2 × 109s 1, and AM-A = 2.325 1 × l023 s 1, respectively. The kinetic equations of the two transfornations during heating were established simultaneously.

  20. High-pressure synthesis of ferromagnetic Mn3Ge with the Cu3Au-type structure

    Science.gov (United States)

    Takizawa, H.; Yamashita, T.; Uheda, K.; Endo, T.

    2002-11-01

    A new intermetallic compound, Mn3Ge, has been synthesized by direct reaction of elemental components at 6.2 GPa and 1000°C for 30 min using a belt-type high-pressure apparatus. The compound crystallizes into a cubic structure with the space group Pm3m, namely the L12-type (Cu3Au-type) structure. The structure was refined by Rietveld analysis of the powder x-ray diffraction data and the lattice constant was determined as a = 0.380 19(3) nm. The compound shows metallic conductivity and ferromagnetism with a Curie temperature of 400 K.

  1. Oxidative removal of aqueous steroid estrogens by manganese oxides.

    Science.gov (United States)

    Xu, Lei; Xu, Chao; Zhao, Meirong; Qiu, Yuping; Sheng, G Daniel

    2008-12-01

    This study investigated the oxidative removal of steroid estrogens from water by synthetic manganese oxide (MnO2) and the factors influencing the reactions. Using 1 x 10(-5)M MnO2 at pH 4, estrone (E1), 17beta-estradiol (E2), estriol (E3) and 17alpha-ethinylestradiol (EE2), all at 4 x 10(-6)M, were rapidly removed within 220 min, indicating the effectiveness of MnO2 as an oxidizing agent towards estrogens. E2 removal increased with decreasing pH over the tested range of 4-8, due most likely to increased oxidizing power of MnO2 and a cleaner reactive surface in acidic solutions. Coexisting metal ions of 0.01 M (Cu(II), Zn(II), Fe(III) and Mn(II)) and Mn(II) released from MnO2 reduction competed with E2 for reactive sites leading to reduced E2 removal. Observed differential suppression on E2 removal may be related to different speciations of metals, as suggested by the MINTEQ calculations, and hence their different adsorptivities on MnO2. By suppressing the metal effect, humic acid substantially enhanced E2 removal. This was attributed to complexation of humic acid with metal ions. With 0.01 M ZnCl2 in solutions containing 1 mg l(-1) humic acid, the binding of humic acid for Zn(II) was determined at 251 mmol g(-1). An in vitro assay using human breast carcinoma MCF-7 cells indicated a near elimination of estrogenic activities without secondary risk of estrogen solutions treated with MnO2. Synthetic MnO2 is therefore a promising chemical agent under optimized conditions for estrogen removal from water. Metal chelators recalcitrant to MnO2 oxidation may be properly used to further enhance the MnO2 performance.

  2. Thermal cycling effect in Cu-11.9Al-2.5Mn shape memory alloy with high Ms temperature

    Institute of Scientific and Technical Information of China (English)

    曹玲飞; 汪明朴; 李周; 徐贲; 苏玉长

    2002-01-01

    The effects of thermal cycling on martensite transformation in Cu-11. 9Al-2.5Mn(mass fraction, % ) shape memory alloy(SMA) with high Ms temperature were studied by means of electrical tension vs temperature (U-T) measurement, optical microscopy observation and X-ray diffractometry. It shows that with increasing thermal cycles, the transformation temperatures decreased, which are accompanied by changes of martensite structure such as the decline of NNN ordering degree and monoclinic angle β→90°. Compared with traditional Cu-base SMA, the alloy has rather high thermostability and can work at 200 ~ 300 ℃. Its excellent thermostability comes from two factors: 1) its β1 parent structure is stable and difficult to decompose at work temperature; 2) its martensite structure is close to N18R(β = 89.6'), which restrains the process of M18R→N18R and the tendency of martensite stabilization and decomposition.

  3. Synthesis, spectroscopic characterization, DNA interaction and biological activities of Mn(II), Co(II), Ni(II) and Cu(II) complexes with [(1H-1,2,4-triazole-3-ylimino)methyl]naphthalene-2-ol

    Science.gov (United States)

    Gaber, Mohamed; El-Wakiel, Nadia A.; El-Ghamry, Hoda; Fathalla, Shaimaa K.

    2014-11-01

    Manganese(II), cobalt(II), nickel(II) and copper(II) complexes of [(1H-1,2,4-triazole-3-ylimino)methyl]naphthalene-2-ol have been synthesized. The structure of complexes have been characterized by elemental analysis, molar conductance, magnetic moment measurements and spectral (IR, 1H NMR, EI-mass, UV-Vis and ESR), and thermal studies. The results showed that the chloro and nitrato Cu(II) complexes have octahedral geometry while Ni(II), Co(II) and Mn(II) complexes in addition to acetato Cu(II) complex have tetrahedral geometry. The possible structures of the metal complexes have been computed using the molecular mechanic calculations using the hyper chem. 8.03 molecular modeling program to confirm the proposed structures. The kinetic and thermodynamic parameters of the thermal decomposition steps were calculated from the TG curves. The binding modes of the complexes with DNA have been investigated by UV-Vis absorption titration. The results showed that the mode of binding of the complexes to DNA is intercalative or non-intercalative binding modes. Schiff base and its metal complexes have been screened for their in vitro antimicrobial activities against Gram positive bacteria (Staphylococcus aureus), Gram negative bacteria (Escherichia coli and Pesudomonas aeruginosa), fungi (Asperigllus flavus and Mucer) and yeast (Candida albicans and Malassezia furfur).

  4. Iron and manganese oxide mineralization in the Pacific

    Science.gov (United States)

    Hein, J.R.; Koschinsky, A.; Halbach, P.; Manheim, F. T.; Bau, M.; Kang, J.-K.; Lubick, N.

    1997-01-01

    Iron, manganese, and iron-manganese deposits occur in nearly all geomorphologic and tectonic environments in the ocean basins and form by one or more of four processes: (1) hydrogenetic precipitation from cold ambient seawater, (2) precipitation from hydrothermal fluids, (3) precipitation from sediment pore waters that have been modified from bottom water compositions by diagenetic reactions in the sediment column and (4) replacement of rocks and sediment. Iron and manganese deposits occur in five forms: nodules, crusts, cements, mounds and sediment-hosted stratabound layers. Seafloor oxides show a wide range of compositions from nearly pure iron to nearly pure manganese end members. Fe/Mn ratios vary from about 24 000 (up to 58% elemental Fe) for hydrothermal seamount ironstones to about 0.001 (up to 52% Mn) for hydrothermal stratabound manganese oxides from active volcanic arcs. Hydrogenetic Fe-Mn crusts that occur on most seamounts in the ocean basins have a mean Fe/Mn ratio of 0.7 for open-ocean seamount crusts and 1.2 for continental margin seamount crusts. Fe-Mn nodules of potential economic interest from the Clarion-Clipperton Zone have a mean Fe/Mn ratio of 0.3, whereas the mean ratio for nodules from elsewhere in the Pacific is about 0.7. Crusts are enriched in Co, Ni and Pt and nodules in Cu and Ni, and both have significant concentrations of Pb, Zn, Ba, Mo, V and other elements. In contrast, hydrothermal deposits commonly contain only minor trace metal contents, although there are many exceptions, for example, with Ni contents up to 0.66%, Cr to 1.2%, and Zn to 1.4%. Chondrite-normalized REE patterns generally show a positive Ce anomaly and abundant ΣREEs for hydrogenetic and mixed hydrogenetic-diagenetic deposits, whereas the Ce anomaly is negative for hydrothermal deposits and ΣREE contents are low. However, the Ce anomaly in crusts may vary from strongly positive in East Pacific crusts to slightly negative in West Pacific crusts, which may reflect

  5. Spin resolved photoelectron spectroscopy of [Mn{sub 6}{sup III}Cr{sup III}]{sup 3+} single-molecule magnets and of manganese compounds as reference layers

    Energy Technology Data Exchange (ETDEWEB)

    Helmstedt, Andreas; Mueller, Norbert; Gryzia, Aaron; Dohmeier, Niklas; Brechling, Armin; Sacher, Marc D; Heinzmann, Ulrich [Fakultaet fuer Physik, Universitaet Bielefeld, Universitaetsstrasse 25, 33615 Bielefeld (Germany); Hoeke, Veronika; Krickemeyer, Erich; Glaser, Thorsten [Fakultaet fuer Chemie, Universitaet Bielefeld, Universitaetsstrasse 25, 33615 Bielefeld (Germany); Bouvron, Samuel; Fonin, Mikhail [Fachbereich Physik, Universitaet Konstanz, Universitaetsstrasse 10, 78457 Konstanz (Germany); Neumann, Manfred, E-mail: andreas.helmstedt@uni-bielefeld.de [Fachbereich Physik, Universitaet Osnabrueck, Barbarastrasse 7, 49069 Osnabrueck (Germany)

    2011-07-06

    Properties of the manganese-based single-molecule magnet [Mn{sup III}{sub 6}Cr{sup III}]{sup 3+} are studied. It contains six Mn{sup III} ions arranged in two bowl-shaped trinuclear triplesalen building blocks linked by a hexacyanochromate and exhibits a large spin ground state of S{sub t} = 21/2. The dominant structures in the electron emission spectra of [Mn{sup III}{sub 6}Cr{sup III}]{sup 3+} resonantly excited at the L{sub 3}-edge are the L{sub 3}M{sub 2,3}M{sub 2,3}, L{sub 3}M{sub 2,3}V and L{sub 3}VV Auger emission groups following the decay of the primary p{sub 3/2} core hole state. Significant differences of the Auger spectra from intact and degraded [Mn{sup III}{sub 6}Cr{sup III}]{sup 3+} show up. First measurements of the electron spin polarization in the L{sub 3}M{sub 2,3}V and L{sub 3}VV Auger emission peaks from the manganese constituents in [Mn{sup III}{sub 6}Cr{sup III}]{sup 3+} resonantly excited at the L{sub 3}-edge near 640 eV by circularly polarized synchrotron radiation are reported. In addition spin resolved Auger electron spectra of the reference substances MnO, Mn{sub 2}O{sub 3} and Mn{sup II}(acetate){sub 2{center_dot}}4H{sub 2}O are given. The applicability of spin resolved electron spectroscopy for characterizing magnetic states of constituent atoms compared to magnetic circular dichroism (MCD) is verified: the spin polarization obtained from Mn{sup II}(acetate){sub 2{center_dot}}4H{sub 2}O at room temperature in the paramagnetic state compares to the MCD asymmetry revealed for a star-shaped molecule with a Mn{sub 4}{sup II}O{sub 6} core at 5 K in an external magnetic field of 5 T.

  6. Ability of Mn2+ to Permeate the Eye and Availability of Manganese-enhanced Magnetic Resonance Imaging for Visual Pathway Imaging via Topical Administration

    Directory of Open Access Journals (Sweden)

    Yao Chen

    2016-01-01

    Conclusions: The corneal epithelium is a barrier to Mn2+, and the iris and lens septum might be another intraocular barrier to the permeation of Mn2+. An elevated Mn2+ concentration contributes to the increased permeation of Mn2+, higher MEMRI signal, and corneal toxicity. The enhancement of the visual pathway requires an effective Mn2+ concentration in the vitreous body.

  7. Study of Cu-Mn-Fe Compound in Wet Catalytic Oxidation of Phenol Wastewater%Cu-Mn-Fe催化湿式氧化苯酚废水的研究

    Institute of Scientific and Technical Information of China (English)

    秦传高; 崔瑞宇; 高迎明; 乔新平

    2015-01-01

    The Cu-Mn-Fe composite oxide catalysts were synthesized by co-precipitation method. The activity of the catalysts in wet catalytic oxidation of phenol wastewater were investigated and the optimum conditions were determined. The results showed that the optimum preparation conditions were as followed: the amount of catalyst addition was 0.7g/L, the amount of 30%H2O2addition was 50 mL/L, the treatment temperature was 55℃ and the treatment time was 2h. The highest removal rate of COD of phenol wastewater was 71.9%.%采用共沉淀法制取Cu-Mn-Fe复合金属氧化物,考察其催化湿式氧化苯酚废水的活性,并确定最佳工艺条件。结果表明,在催化剂用量为0.7g·L-1,30%过氧化氢用量为50mL·L-1,反应时间2h,反应温度55℃的条件下,苯酚废水的COD去除率最高可达71.9%。

  8. First-principles molecular spin dynamics study on the magnetic structure of Mn-based alloys with Cu3Au-type crystal structure

    Science.gov (United States)

    Uchida, T.; Kakehashi, Y.; Kimura, N.

    2016-02-01

    The magnetic and electronic structures of Mn3Pt and Mn3Rh, which are three-dimensional frustrated itinerant magnets with a Cu3Au-type crystal structure, have been investigated by means of the first-principles Molecular Spin Dynamics (MSD) method. The theory is based on the first-principles tight-binding linear muffin-tin orbital Hamiltonian combined with the functional integral method and the isothermal MSD technique, and allows us to determine automatically the magnetic structures of itinerant magnets at finite temperatures. The MSD calculations using a self-consistent site-dependent effective medium show that below the Néel temperature Mn3Pt with fixed crystal structure (Cu3Au structure) and volume exhibits a second-order transition from a triangular structure to another noncollinear phase with increasing temperature. Mn3Rh, on the other hand, shows no sign of a phase transition up to the Néel temperature. We found that the Mn-Eg DOS peak, which is responsible for the ferromagnetic couplings among the second nearest-neighbor Mn local moments, develops at the Fermi energy (EF) around 350 K for Mn3Pt, while the peak development for Mn3Rh occurs with increasing temperature slightly above EF.

  9. Latent manganese deficiency in barley can be diagnosed and remediated on the basis of chlorophyll a fluorescence measurements

    DEFF Research Database (Denmark)

    Schmidt, Sidsel Birkelund; Pedas, Pai; Laursen, Kristian Holst;

    2013-01-01

    chlorophyll (Chl) a fluorescence as a tool for diagnosis of latent Mn deficiency. Methods: Barley plants grown under controlled greenhouse conditions or in the field were exposed to different intensities of Mn deficiency. The responses were characterised by analysis of Chl a fluorescence, photosystem II (PSII......) proteins and mineral elements. Results: Analysis of the Chl a fluorescence induction kinetics (FIK) revealed distinct changes long before any visual symptoms of Mn deficiency were apparent. The changes were specific for Mn and did not occur in Mg, S, Fe or Cu deficient plants. The changes in Mn deficient......Background and aims: Manganese (Mn) deficiency represents a major plant nutritional disorder in winter cereals. The deficiency frequently occurs latently and the lack of visual symptoms prevents timely remediation and cause significant yield reductions. These problems prompted us to investigate...

  10. Direct imaging of thermally-activated grain-boundary diffusion in Cu/Co/IrMn/Pt exchange-bias structures using atom-probe tomography

    Energy Technology Data Exchange (ETDEWEB)

    Letellier, F.; Lardé, R.; Le Breton, J.-M., E-mail: jean-marie.lebreton@univ-rouen.fr [Groupe de Physique des Matériaux, UMR 6634 CNRS/Université et INSA de Rouen, F-76801 Saint Etienne du Rouvray (France); Lechevallier, L. [Groupe de Physique des Matériaux, UMR 6634 CNRS/Université et INSA de Rouen, F-76801 Saint Etienne du Rouvray (France); Département de GEII, Université de Cergy-Pontoise, F-95031 Cergy-Pontoise (France); Akmaldinov, K. [SPINTEC, Univ. Grenoble-Alpes/CNRS/INAC-CEA, F-38000 Grenoble (France); CROCUS Technology, F-38025 Grenoble (France); Auffret, S.; Dieny, B.; Baltz, V., E-mail: vincent.baltz@cea.fr [SPINTEC, Univ. Grenoble-Alpes/CNRS/INAC-CEA, F-38000 Grenoble (France)

    2014-11-28

    Magnetic devices are often subject to thermal processing steps, such as field cooling to set exchange bias and annealing to crystallize amorphous magnetic electrodes. These processing steps may result in interdiffusion and the subsequent deterioration of magnetic properties. In this study, we investigated thermally-activated diffusion in Cu/Co/IrMn/Pt exchange biased polycrystalline thin-film structures using atom probe tomography. Images taken after annealing at 400 °C for 60 min revealed Mn diffusion into Co grains at the Co/IrMn interface and along Pt grain boundaries for the IrMn/Pt stack, i.e., a Harrison type C regime. Annealing at 500 °C showed further Mn diffusion into Co grains. At the IrMn/Pt interface, annealing at 500 °C led to a type B behavior since Mn diffusion was detected both along Pt grain boundaries and also into Pt grains. The deterioration of the films' exchange bias properties upon annealing was correlated to the observed diffusion. In particular, the topmost Pt capping layer thickness turned out to be crucial since a faster deterioration of the exchange bias properties for thicker caps was observed. This is consistent with the idea that Pt acts as a getter for Mn, drawing Mn out of the IrMn layer.

  11. The ternary germanides UMnGe and U2Mn3Ge

    Science.gov (United States)

    Hoffmann, Rolf-Dieter; Pöttgen, Rainer; Chevalier, Bernard; Gaudin, Etienne; Matar, Samir F.

    2013-07-01

    The title compounds were prepared by induction levitation melting of the elemental components and subsequent annealing. UMnGe (Pnma, a = 686.12(9), b = 425.49(6) and c = 736.5(1) pm) adopts the orthorhombic structure of TiNiSi and U2Mn3Ge (P63/mmc, a = 524.3(2) and c = 799.2(3) pm) possesses the hexagonal Mg2Cu3Si-type structure (ordered variant of the hexagonal Laves phase MgZn2). Both structures were refined from X-ray powder data to residuals of RI = 0.021 and 0.014 for UMnGe and U2Mn3Ge, respectively. The manganese and germanium atoms in UMnGe build up a three-dimensional [MnGe] network of ordered Mn3Ge3 hexagons with Mn-Ge distances ranging from 248 to 259 pm. The uranium atoms are coordinated by two tilted Mn3Ge3 hexagons. The manganese atoms in U2Mn3Ge build up Kagomé networks with 252 and 272 pm Mn-Mn distances which are connected via the germanium atoms (254 pm Mn-Ge) to a three-dimensional network. A remarkable feature of the U2Mn3Ge structure is a short U-U distance of 278 pm between adjacent cavities of the [Mn3Ge] network. From DFT based electronic structure calculations both germanides are found more cohesive than the Laves phase UMn2, thus underpinning the substantial role of Mn-Ge bonding. Calculations for both germanides show ferrimagnetic ground states with antiparallel spin alignments between U and Mn. The valence bands show bonding characteristics for interactions of atoms of different chemical natures and significant Mn-Mn bonding in U2Mn3Ge. Preliminary investigation of UMnGe by magnetization measurements confirms an antiferromagnetic arrangement below TN = 240 K.

  12. Thermal Stability and Reductive Property of CexZr1-xO2 Solid Solution Doped Simultaneously by Fe, Mn or Fe, Cu

    Institute of Scientific and Technical Information of China (English)

    Yan Zhongjun; Yang Dong; Wen Mingfen; Chen Jing; Wang Jinggang; Gu Yongwan

    2005-01-01

    CexZr1-xO2 complex oxides doped by transition metal(Fe, Mn, Cu) were prepared by precipitation method. Thermal stability of samples was characterized by XRD, surface areas were measured by BET method and reductive property was characterized by TPR. The results show that MnO2 can be dispersed in solid solution after calcined at 1273 K, when the loading is 12%, while Fe and Cu is easy to separate from samples at this temperature. Samples doped simultaneously by Fe, Mn or Fe, Cu demonstrated high reactive property at low temperature. The starting reduction temperature are 413 and 373 K, respectively. TPR results also show a broad range of reductive temperature exists in these bi-metal doped samples.

  13. Influence of heat treatment on microstructure and tensile properties of a cast Al-Cu-Si-Mn alloy

    Directory of Open Access Journals (Sweden)

    Liu Zhixue

    2013-11-01

    Full Text Available Solution and aging treatments are important approaches to improve mechanical properties and microstructure of aluminum-base alloys. In this research, a new type high strength Al-Cu-Si-Mn cast alloy was prepared. The effect of different solution and aging treatment temperatures on microstructure and mechanical properties of the Al-Cu-Si-Mn cast alloy were studied by means of microstructure observation and mechanical properties testing. Results showed that after solution treated at different temperatures for 12 h and aged at 175 ℃ for 12 h, with the increase of the solution temperature, both the tensile strength and the elongation of the alloy firstly increase and then decrease, and reach their peak values at 530 ℃. When the solution temperature is below 530 ℃, the microstructure of the alloy consists of α phase, undissolved θ phase and T phase; while when it exceeds 530 ℃, the microstructure only consists of α phase and T phase. After solution treated at 530 ℃ for 12 h and aged at different temperatures for 12 h, both the tensile strength and the elongation of the alloy firstly increase and then decrease with the increasing of temperature, and reach their peak values at 175 ℃. Therefore, the optimal heat treatment process for the alloy in this study is 12 h solution at 530 ℃ and 12 h aging at 175 ℃, and the corresponding tensile strength is 417 MPa, elongation is 4.0%.

  14. Pecan nutshell as biosorbent to remove Cu(II), Mn(II) and Pb(II) from aqueous solutions.

    Science.gov (United States)

    Vaghetti, Julio C P; Lima, Eder C; Royer, Betina; da Cunha, Bruna M; Cardoso, Natali F; Brasil, Jorge L; Dias, Silvio L P

    2009-02-15

    In the present study we reported for the first time the feasibility of pecan nutshell (PNS, Carya illinoensis) as an alternative biosorbent to remove Cu(II), Mn(II) and Pb(II) metallic ions from aqueous solutions. The ability of PNS to remove the metallic ions was investigated by using batch biosorption procedure. The effects such as, pH, biosorbent dosage on the adsorption capacities of PNS were studied. Four kinetic models were tested, being the adsorption kinetics better fitted to fractionary-order kinetic model. Besides that, the kinetic data were also fitted to intra-particle diffusion model, presenting three linear regions, indicating that the kinetics of adsorption should follow multiple sorption rates. The equilibrium data were fitted to Langmuir, Freundlich, Sips and Redlich-Peterson isotherm models. Taking into account a statistical error function, the data were best fitted to Sips isotherm model. The maximum biosorption capacities of PNS were 1.35, 1.78 and 0.946mmolg(-1) for Cu(II), Mn(II) and Pb(II), respectively.

  15. Cd, Cu, and Mn from Uruguay River Basin in Uruguaiana, RS, Brazil, and their toxicological potential for human leukocyte

    Directory of Open Access Journals (Sweden)

    Gislaine Rezer Costa

    2016-12-01

    Full Text Available This study assessed the limnology from the Medium Uruguay River Basin in Uruguaiana, Brazil, with a focus on the concentration of heavy metals (Cd, Cu, and Mn, to assess the toxicological potential (cytotoxicity and genotoxicity for humans using as biological matrix of study human leukocyte cells. The conductivity, resistivity, and dissolved O2 levels exceeded the limits recommended by the National Environmental Council (Conselho Nacional do Meio Ambiente - CONAMA. The percentage of non-viable human leukocyte cells exposed to water samples was approximately 20% higher than that of the negative control (<3%, but similar to the positive control. The DNA damage index was high for all heavy metal concentrations assayed when compared to the negative control 12±2.96, p < 0.0001, with a range of 155.66±23.89 to 194.33±23.23, but similar to the positive control (210.62±27.48. Moreover, the leukocyte degeneration index was higher in all samples containing heavy metals than in the negative control (4%, which demonstrates to be due the presence of Cu (11.8-12.5%, Cd (13-15.6%, and Mn (15.6-22.5%. Taken together, our results show that the quality from water samples analyzed is below than recommended by CONAMA and offers risk of contamination by heavy metals for the general population.

  16. Rapid Directional Solidification with Ultra-High Temperature Gradient and Cellular Spacing Selection of Cu-Mn Alloy

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The detailed laser surface remelting experiments of Cu-31.4 wt pct Mn and Cu-26.6 wt pct Mn alloys on a 5 kW CO2laser were carried out to study the effects of processing parameters (scanning velocity, output power of laser) on the growthdirection of microstructure in the molten pool and cellular spacing selection under the condition of ultra-high temperaturegradient and rapid directional solidification. The experimental results show that the growth direction of microstructure isstrongly affected by laser processing parameters. The ultra-high temperature gradient directional solidification can be realizedon the surface of samples during laser surface remelting by controlling laser processing parameters, the temperature gradientand growth velocity can reach 106 K/m and 24.1 mm/s, respectively, and the solidification microstructure in the center ofthe molten pool grows along the laser beam scanning direction. There exists a distribution range of cellular spacings underthe laser rapid solidification conditions, and the average spacing decreases with increasing of growth rate. The maximum,λ minimum, λmin, and average primary spacing,λ, as functions of growth rate, Vb, can be given by, λ =12.54V b-0.61,λmin=4.47 Vb-0.52, λ=9.09Vb-0.62, respectively. The experimental results are compared with the current Hunt-Lu model forrapid cellular/dendritic growth, and a good agreement is found.

  17. Effect of Austenite Transformation on Abrasive Wear and Corrosion Resistance of Spheroidal Ni-Mn-Cu Cast Iron

    Directory of Open Access Journals (Sweden)

    Medyński D.

    2016-09-01

    Full Text Available Within the presented work, the effect of austenite transformation on abrasive wear as well as on rate and nature of corrosive destruction of spheroidal Ni-Mn-Cu cast iron was determined. Cast iron contained: 3.1÷3.4 %C, 2.1÷2.3 %Si, 2.3÷3.3 %Mn, 2.3÷2.5 %Cu and 4.8÷9.3 %Ni. At a higher degree of austenite transformation in the alloys with nickel equivalent below 16.0%, abrasive wear resistance was significantly higher. Examinations of the corrosion resistance were carried out with the use of gravimetric and potentiodynamic method. It was shown that higher degree of austenite transformation results in significantly higher abrasive wear resistance and slightly higher corrosion rate, as determined by the gravimetric method. However, results of potentiodynamic examinations showed creation of a smaller number of deep pinholes, which is a favourable phenomenon from the viewpoint of corrosion resistance.

  18. ETAAS method for the determination of Cd, Cr, Cu, Mn and Se in blood fractions and whole blood

    Energy Technology Data Exchange (ETDEWEB)

    Prohaska, C.; Pomazal, K.; Steffan, I. [Technische Univ., Vienna (Austria). Inst. fuer Analytische Chemie

    2000-11-01

    An electrothermal atomic absorption method (ETAAS) for the direct determination of trace elements (Cd, Cr, Cu, Mn, Se) both in blood fractions (erythrocytes, plasma and lymphocytes) and whole blood was developed. Zeeman background correction and graphite tubes with L'vov platforms were used. Samples were diluted with HNO{sub 3}/Triton X-100 and pipetted directly into the graphite tube. Ashing, pretreatment and atomization steps were optimized carefully for the different fractions and elements applying different matrix modifiers for each element. For the lymphocyte fraction a multi-fold injection technique was applied. Low detection limits of the ETAAS method (Cd 0.13 {mu}g/L, Cr 0.11 {mu}g/L, Cu 0.52 {mu}g/L, Mn 0.13 {mu}g/L, Se 0.7 {mu}g/L of whole blood) combined with small quantities of sample necessary for analysis allow determination of trace elements in this matrix. Verification of possible differences in the trace element status of humans was performed with statistical significance (P < 0.05). In addition, a contribution to the determination of normal values of essential elements was achieved. The method was applied for determination of trace elements in human blood and blood fractions of two groups (n = 50) different in health status. (orig.)

  19. Cu-Mn-Ni-Ag钎料高频感应钎焊2Cr13不锈钢接头的显微组织与性能%Microstructure andperformance of 2Cr13stainless steel joint by high frequency induction brazing usingCu-Mn-Ni-Agfiller alloy

    Institute of Scientific and Technical Information of China (English)

    郑义; 颜家振; 李宁; 曹永同; 帅帆

    2016-01-01

    The characteristic of Cu-Mn-Ni-Ag filler alloy and the microstructure and mechanical properties of the 2Cr13 stainless steel joint brazed by high frequency induction brazing using Cu-Mn-Ni-Ag filler alloywerestudied. The results show that the melting point of the Cu-Mn-Ni-Ag filler alloy is 880℃and it is composed of Ag-rich phase, Cu-Mn-Ni solid solution and a little Ni-Mn-Si compound; a layer of Fe-Mn-Ni-Cr-Cu solid solution forms at the interface between the filler alloy and base metal, and the brazing seam zone is composed of Ag-rich phase, Cu-Mn-Ni solid solution and a little Ni-Mn-Si compound. The brazing jointsfailsin the inside Cu-Mn-Ni solid solution and Ag-rich phase, and the fracture mode of the joints is mainly ductile dimple fracture, the best shear strength of the brazing joint at room temperature is 369 MPa, the high temperature shear strength of the brazing joints at 400℃, 500℃and 600℃are 251 MPa, 208 MPa and 84 MPa,respectively.%采用新型的Cu-Mn-Ni-Ag中温铜基钎料高频感应钎焊2Cr13不锈钢,并对钎料的工艺特性、钎焊接头的显微组织以及测试温度对钎焊接头力学性能的影响进行研究。结果表明:Cu-Mn-Ni-Ag钎料的熔点约为880℃,由富Ag相、Cu-Mn-Ni固溶体以及少量的Ni-Mn-Si化合物组成;钎料与2Cr13不锈钢产生良好的冶金结合,且钎焊接头组织致密;界面反应区的组织为Fe-Mn-Ni-Cr-Cu固溶体,钎缝区组织由富Ag相、Cu-Mn-Ni固溶体和少量的Ni-Mn-Si化合物组成;钎焊接头断裂于钎缝中间的富Ag相和CuMnNi固溶体上,为以剪切韧窝为主的韧性断裂,室温剪切强度最大可达369 MPa,在400℃、500℃和600℃下接头的剪切强度分别为251 MPa、208 MPa和84 MPa。

  20. Aflatoxin detoxification by manganese peroxidase purified from Pleurotus ostreatus

    Directory of Open Access Journals (Sweden)

    Ramy Sayed Yehia

    2014-01-01

    Full Text Available Manganese peroxidase (MnP was produced from white rot edible mushroom Pleurotus ostreatus on the culture filtrate. The enzyme was purified to homogeneity using (NH42SO4 precipitation, DEAE-Sepharose and Sephadex G-100 column chromatography. The final enzyme activity achieved 81UmL-1, specific activity 78 U mg-1 with purification fold of 130 and recovery 1.2% of the crude enzyme. SDS-PAGE indicated that the pure enzyme have a molecular mass of approximately 42 kDa. The optimum pH was between 4-5 and the optimum temperature was 25 ºC. The pure MnP activity was enhanced by Mn2+,Cu2+,Ca2+ and K+ and inhibited by Hg+2 and Cd+2.H2O2 at 5 mM enhanced MnP activity while at 10 mM inhibited it significantly. The MnP-cDNA encoding gene was sequenced and determined (GenBank accession no. AB698450.1. The MnP-cDNA was found to consist of 497 bp in an Open Reading Frame (ORF encoding 165 amino acids. MnP from P. ostreatus could detoxify aflatoxin B1 (AFB1 depending on enzyme concentration and incubation period. The highest detoxification power (90% was observed after 48 h incubation at 1.5 U mL-1 enzyme activities.

  1. Aflatoxin detoxification by manganese peroxidase purified from Pleurotus ostreatus.

    Science.gov (United States)

    Yehia, Ramy Sayed

    2014-01-01

    Manganese peroxidase (MnP) was produced from white rot edible mushroom Pleurotus ostreatus on the culture filtrate. The enzyme was purified to homogeneity using (NH4)2SO4 precipitation, DEAE-Sepharose and Sephadex G-100 column chromatography. The final enzyme activity achieved 81 U mL(-1), specific activity 78 U mg(-1) with purification fold of 130 and recovery 1.2% of the crude enzyme. SDS-PAGE indicated that the pure enzyme have a molecular mass of approximately 42 kDa. The optimum pH was between 4-5 and the optimum temperature was 25 °C. The pure MnP activity was enhanced by Mn(2+), Cu(2+), Ca(2+) and K(+) and inhibited by Hg(+2) and Cd(+2). H2O2 at 5 mM enhanced MnP activity while at 10 mM inhibited it significantly. The MnP-cDNA encoding gene was sequenced and determined (GenBank accession no. AB698450.1). The MnP-cDNA was found to consist of 497 bp in an Open Reading Frame (ORF) encoding 165 amino acids. MnP from P. ostreatus could detoxify aflatoxin B1 (AFB1) depending on enzyme concentration and incubation period. The highest detoxification power (90%) was observed after 48 h incubation at 1.5 U mL(-1) enzyme activities.

  2. Preparation and physical properties of the solid solutions Cu 1+xMn 1-xO 2 ( 0⩽x⩽0.2)

    Science.gov (United States)

    Trari, M.; Töpfer, J.; Dordor, P.; Grenier, J. C.; Pouchard, M.; Doumerc, J. P.

    2005-09-01

    Solid solutions of formula Cu 1+xMn 1-xO 2 ( 0⩽x⩽0.2) were synthesized by solid state reaction in silica sealed tubes. They crystallize with the monoclinic crednerite structure (space group C2/ m). The stability domain in air is quite narrow and a phase diagram is proposed and compared with previous results. Magnetic study confirmed the HS state of Mn 3+ ions and revealed that the predominant interactions are antiferromagnetic. Their strength decreases with x, which can be ascribed to a dilution effect, and long-range 3D magnetic ordering observed for CuMnO 2, disappears for x> 0.05. The crednerite solid solutions are p-type semiconductors. Modeling the thermoelectric power behavior suggests that charge carriers are Cu 2+ holes diffusing in Cu layers for small x values and Mn 4+ holes diffusing in Mn layers for x>0.05. For larger x values a saturation effect limits the charge carrier concentration.

  3. Recycling of valuable metals from spent zinc-manganese batteries by vacuum metallurgy

    Institute of Scientific and Technical Information of China (English)

    陈为亮; 柴立元; 闵小波; 彭兵; 张传福; 戴永年

    2003-01-01

    At the total chamber pressure of 1.01×101 Pa, Hg, Cd and Zn were distilled at 773-973 K from spent zinc-manganese batteries, Pb was volatilized at 1 173-1 273 K while Mn, Cu, Fe and C were remained in the residual. MnO2 and ZnO were reduced by carbon in spent dry-batteries at 773-1 273 K. Pure metals including Zn, Cd, Hg and Pb were recovered respectively from their mixed vapor by fractional condensation.

  4. Manganese exposure in foundry furnacemen and scrap recycling workers

    DEFF Research Database (Denmark)

    Lander, F; Kristiansen, J; Lauritsen, Jens

    1999-01-01

    Cast iron products are alloyed with small quantities of manganese, and foundry furnacemen are potentially exposed to manganese during tapping and handling of smelts. Manganese is a neurotoxic substance that accumulates in the central nervous system, where it may cause a neurological disorder...... that bears many similarities to Parkinson's disease. The aim of the study was to investigate the sources and levels of manganese exposure in foundry furnacemen by a combined measuring of blood-manganese (B-Mn) and manganese in ambient air (air-Mn)....

  5. Investigation of electronic structure, magnetic and transport properties of half-metallic Mn{sub 2}CuSi and Mn{sub 2}ZnSi Heusler alloys

    Energy Technology Data Exchange (ETDEWEB)

    Bhat, Idris Hamid, E-mail: idu.idris@gmail.com; Yousuf, Saleem; Mohiuddin Bhat, Tahir; Gupta, Dinesh C., E-mail: sosfizix@gmail.com

    2015-12-01

    The electronic and magnetic properties of Mn{sub 2}CuSi and Mn{sub 2}ZnSi Heusler alloys have been investigated using full-potential linearized augmented plane wave method. The optimized equilibrium lattice parameters in stable F-43m configuration are found to be 5.75 Å for Mn{sub 2}CuSi and 5.80 Å for Mn{sub 2}ZnSi. Spin-resolved calculations show that the Mn atoms at inequivalent Wyckoff positions have different contributions to the total magnetic moment in the unit cell. The anti-parallel magnetic moments of inequivalent Mn atoms sum to an integer with total magnetic moment per unit cell. The 100% spin-polarization at Fermi energy together with the total magnetic moment of 1.0 µ{sub B} for Mn{sub 2}CuSi and 2.0 µ{sub B} for Mn{sub 2}ZnSi per unit cell, predict that the materials follow M{sub T}=Z{sub T} – 28 Slater–Pauling rule. Both the materials under study exhibit half-metallicity with an energy gap in the spin-down channels. In the study, we predict a rather fine value of Seebeck coefficient. Further, the decreasing electrical conductivity with temperature shows a metallic character in spin-up configurations, while the electrical conductivity of spin-down states follows a semiconductor-like trend. - Highlights: • Half-metallic materials. • Highly spin-polarized. • Possess large conductivity in spin-up and large resistivity in spin-down channels. • Large Seebeck coefficient makes them suitable thermoelectric materials.

  6. Reducción catalítica de NOx con Pt soportado sobre zeolitas MFI modificadas con Cu, Co, Fe, Mn.

    Directory of Open Access Journals (Sweden)

    Sarah Briceño

    2008-05-01

    Full Text Available The selective catalytic reduction of NO by propane in the presence of excess oxygen has been studied over catalysts based on Pt supported on Fe-ZSM-5, Co-ZSM-5, Cu- ZSM-5 and MnZSM-5. Pure Pt based catalysts are highly active, but produce large amounts of N2O. The bimetallic catalyst was found to offer wider temperature window than that of monocatalysts, and show a synergistic effect by combining high stability and activity of Pt catalysts with the high N2 selectivity of Fe, Co, Cu, Mn supported on MFI catalysts.

  7. Effect of mineral-enriched diet and medicinal herbs on Fe, Mn, Zn, and Cu uptake in chicken

    Directory of Open Access Journals (Sweden)

    Stef Ducu

    2012-03-01

    Full Text Available Abstract Background The goal of our study was to evaluate the effects of different medicinal herbs rich in polyphenol (Lemon balm, Sage, St. John's wort and Small-flowered Willowherb used as dietary supplements on bioaccumulation of some essential metals (Fe, Mn, Zn and Cu in different chicken meats (liver, legs and breast. Results In different type of chicken meats (liver, legs and breast from chickens fed with diets enriched in minerals and medicinal herbs, beneficial metals (Fe, Mn, Zn and Cu were analysed by flame atomic absorption spectrometry. Fe is the predominant metal in liver and Zn is the predominant metal in legs and breast chicken meats. The addition of metal salts in the feed influences the accumulations of all metals in the liver, legs and breast chicken meat with specific difference to the type of metal and meat. The greatest influences were observed in legs meat for Fe and Mn. Under the influence of polyphenol-rich medicinal herbs, accumulation of metals in the liver, legs and breast chicken meat presents specific differences for each medicinal herb, to the control group that received a diet supplemented with metal salts only. Great influence on all metal accumulation factors was observed in diet enriched with sage, which had significantly positive effect for all type of chicken meats. Conclusions Under the influence of medicinal herbs rich in different type of polyphenol, accumulation of metals in the liver, legs and breast chicken meat presents significant differences from the group that received a diet supplemented only with metal salts. Each medicinal herb from diet had a specific influence on the accumulation of metals and generally moderate or poor correlations were observed between total phenols and accumulation of metals. This may be due to antagonism between metal ions and presence of other chelating agents (amino acids and protein from feeding diets which can act as competitor for complexation of metals and influence

  8. Surface Mn(II) oxidation actuated by a multicopper oxidase in a soil bacterium leads to the formation of manganese oxide minerals

    Science.gov (United States)

    Zhang, Zhen; Zhang, Zhongming; Chen, Hong; Liu, Jin; Liu, Chang; Ni, Hong; Zhao, Changsong; Ali, Muhammad; Liu, Fan; Li, Lin

    2015-01-01

    In this manuscript, we report that a bacterial multicopper oxidase (MCO266) catalyzes Mn(II) oxidation on the cell surface, resulting in the surface deposition of Mn(III) and Mn(IV) oxides and the gradual formation of bulky oxide aggregates. These aggregates serve as nucleation centers for the formation of Mn oxide micronodules and Mn-rich sediments. A soil-borne Escherichia coli with high Mn(II)-oxidizing activity formed Mn(III)/Mn(IV) oxide deposit layers and aggregates under laboratory culture conditions. We engineered MCO266 onto the cell surfaces of both an activity-negative recipient and wild-type strains. The results confirmed that MCO266 governs Mn(II) oxidation and initiates the formation of deposits and aggregates. By contrast, a cell-free substrate, heat-killed strains, and intracellularly expressed or purified MCO266 failed to catalyze Mn(II) oxidation. However, purified MCO266 exhibited Mn(II)-oxidizing activity when combined with cell outer membrane component (COMC) fractions in vitro. We demonstrated that Mn(II) oxidation and aggregate formation occurred through an oxygen-dependent biotic transformation process that requires a certain minimum Mn(II) concentration. We propose an approximate electron transfer pathway in which MCO266 transfers only one electron to convert Mn(II) to Mn(III) and then cooperates with other COMC electron transporters to transfer the other electron required to oxidize Mn(III) to Mn(IV). PMID:26039669

  9. Spin glass and ferromagnetic properties of Ce(Cu{sub 1-x}Ni{sub x}){sub 4}Mn alloys: Multicritical points in the magnetic phase diagram

    Energy Technology Data Exchange (ETDEWEB)

    Synoradzki, K., E-mail: karol.synoradzki@ifmpan.poznan.pl; Toliński, T.

    2016-07-01

    We report on the CeNi{sub 4}Mn (ferromagnet FM) - CeCu{sub 4}Mn (spin-glass SG) transformation leading to a complex magnetic phase diagram (MPD). It is verified that all the Ce(Cu{sub 1-x}Ni{sub x}){sub 4}Mn alloys are isostructural and the transformation is governed only by the Cu-Ni substitution. MPD is built based on the magnetic dc/ac susceptibility measurements and reveals SG formation as well as the region of the coexistence of the FM and SG state in the middle range of the Ni concentration. The complex MPD is explained by clusters formation and a competition of interactions between various crystallographic sites of the hexagonal CaCu{sub 5}-type structure, mainly the 3g-3g and 3g-2c interactions. The predominance of the SG state is confirmed by the analysis of the frequency dependence of the ac magnetic susceptibility components and the relaxation of the remanent magnetization. Additionally, the presence of two multicritical points is observed. - Highlights: • We fully characterized the magnetic properties of Ce(Cu{sub 1-x}Ni{sub x}){sub 4}Mn alloys. • We show the presence of complex magnetic behaviour due to atomic-site disorder. • Magnetic phase diagram revels mixed-phase ground state. • Two multicritical points on magnetic phase diagram occurs.

  10. Early induction of Fe-SOD gene expression is involved in tolerance to Mn toxicity in perennial ryegrass.

    Science.gov (United States)

    Ribera-Fonseca, Alejandra; Inostroza-Blancheteau, Claudio; Cartes, Paula; Rengel, Zed; Mora, M L

    2013-12-01

    Manganese (Mn) toxicity limits plant growth in acid soils. Although Mn toxicity induces oxidative stress, the role of superoxide dismutase (SOD, EC.1.15.1.1) isoforms in conferring Mn tolerance remains unclear. Seedlings of ryegrass cultivars Nui (Mn-sensitive) and Kingston (Mn-tolerant) were hydroponically grown at 2.4 (optimal) or 750 μM Mn (toxic) concentration, and harvested from 2 to 48 h. Kingston showed higher shoot Mn than Nui at 2.4 μM Mn. At toxic supply, shoot Mn concentration steadily increased in both cultivars, with Kingston having the highest accumulation at 48 h. An early (2 h) increase in lipid peroxidation under Mn excess occurred, but it returned (after 6 h) to the basal level in Kingston only. Kingston exhibited higher SOD activity than Nui, and that difference increased due to toxic Mn. In general, Mn-induced gene expression of Mn- and Cu/Zn-SOD isoforms was higher in Nui than Kingston. Nevertheless, under Mn excess, we found a greater Fe-SOD up-regulation (up to 5-fold) in Kingston compared to Nui. Thus, Fe-SOD induction in Kingston might explain, at least partly, its high tolerance to Mn toxicity. This is the first evidence that Mn toxicity causes differential gene expression of SOD isoforms in ryegrass cultivars in the short-term.

  11. Synthesis and Properties of New Molecule-Based Magnets Containing Mn(II, Cu(II and Nitronyl Nitroxide Radical Cation

    Directory of Open Access Journals (Sweden)

    Vaz Maria G. F.

    2002-01-01

    Full Text Available In this work, we describe the synthesis of two new copper(II compounds, (Pr-Rad2 [Cu(opba].H2O (1 and (Bu-Rad2[Cu(opba].2H2O (2 where opba stands for ortho-phenylenebis(oxamato and RRad+ are nitronyl nitroxide radical cations. From 1 and 2, two new molecule-based magnets [Pr-Rad]2[Mn2{Cu(opba}3 ].3.3DMSO.5H2O (3 and [Bu-Rad]2 [Mn2{Cu(opba}3].3DMSO.6H 2O (4 were obtained, respectively. The magnetic properties of precursors 1 and 2 show the presence of ferromagnetic interaction between the radical cations with copper(II, in the temperature range of 20-300 K. The magnets 3 and 4 exhibit spontaneous magnetization at critical temperatures, Tc, of 23 K and 24 K, respectively.

  12. Enhanced electrochemical performances of LiNi0.5Mn1.5O4 by surface modification with Cu nanoparticles

    Directory of Open Access Journals (Sweden)

    Zhao G.

    2017-01-01

    Full Text Available 5V spinel LiNi0.5Mn1.5O4 cathode is prepared by traditional solid-state method and nano-Cu particles were derived from a chemical reduction process. The effect of Cu-coating on the electrochemical performances of LiNi0.5Mn1.5O4 cells, in a wide operation temperature range (-10°C, 25°C, 60°C, is investigated systematically by the charge/discharge testing, cyclic voltammograms and impedance spectroscopy, respectively. The results demonstrate that the modified material exhibits remarkably enhanced electrochemical reversibility and stability. Cu-coated material has much lower surface and charge transfer resistances and shows a higher lithium diffusion rate. The Cu coating layer as a highly efficient lithium ion conductor, acted as a highly efficient protector to restrain the contact loss.

  13. Manganese inhibits NMDA receptor channel function: implications to psychiatric and cognitive effects.

    Science.gov (United States)

    Guilarte, Tomás R; Chen, Ming-Kai

    2007-11-01

    Humans exposed to excess levels of manganese (Mn(2+)) express psychiatric problems and deficits in attention and learning and memory. However, there is a paucity of knowledge on molecular mechanisms by which Mn(2+) produces such effects. We now report that Mn(2+) is a potent inhibitor of [(3)H]-MK-801 binding to the NMDA receptor channel in rat neuronal membrane preparations. The inhibition of [(3)H]-MK-801 to the NMDA receptor channel by Mn(2+) was activity-dependent since Mn(2+) was a more potent inhibitor in the presence of the NMDA receptor co-agonists glutamate and glycine (K(i)=35.9+/-3.1 microM) than in their absence (K(i)=157.1+/-6.5 microM). We also show that Mn(2+) is a NMDA receptor channel blocker since its inhibition of [(3)H]-MK-801 binding to the NMDA receptor channel is competitive in nature. That is, Mn(2+) significantly increased the affinity constant (K(d)) with no significant effect on the maximal number of [(3)H]-MK-801 binding sites (B(max)). Under stimulating conditions, Mn(2+) was equipotent in inhibiting [(3)H]-MK-801 b