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1

Mechanical properties and fatigue strength of high-manganese non-magnetic steel\\/carbon steel welded joints  

Microsoft Academic Search

This paper describes performance tests of dissimilar material welded joints produced from carbon steel and a new type of high-manganese non-magnetic steel with improved machinability. The basic mechanical properties of these joints are first described. Fatigue tests are then conducted for purposes of fatigue strength design of the joints within the context of an evaluation of their suitability for application

E. Nakaji; S. Ikeda; Y. C. Kim; Y. Nakatsuji; K. Horikawa

1998-01-01

2

AUSTEMPERING OF A SILICON MANGANESE CAST STEEL  

Microsoft Academic Search

The influence of austempering on the microstructure and mechanical properties of an alloyed cast steel containing high silicon (3.00%) and high manganese (2.00%) was studied. The influence of microstructure on the plain strain fracture toughness of this new steel was also examined. The test results show that by using a suitable austempering process, i.e., by austenitizing at 1010°C (1850°F) for

Susil K. Putatunda

2001-01-01

3

Yttrium implantation effect on low manganese–carbon steel  

Microsoft Academic Search

Low manganese–carbon steels were implanted with yttrium using the ion implantation method. Compositional and structural analyses were carried out before and after yttrium implantation by several techniques such as Rutherford backscattering spectrometry, X-ray photoelectron spectroscopy, reflection high energy electron diffraction, X-ray diffraction and glancing angle X-ray diffraction to observe the yttrium implantation effect on low manganese–carbon steel.

E Caudron; H Buscail; V. A. C Haanapel; Y. P Jacob; M. F Stroosnijder

2000-01-01

4

Cavitation Erosion Damage on High Manganese Austenitic Steel.  

National Technical Information Service (NTIS)

As suggested by recent literature a high manganese, high chromium, medium carbon steel (0.25C, 13Cr, 10Mn) is extremely cavitation-resistent. Since this steel is not available in this country, a small lot was induction melted and cast into bars. Tensile t...

F. G. Hammitt C. Chao

1968-01-01

5

Manganese.  

PubMed

Manganese is a very hard, brittle metal, which is used to increase the strength of steel alloys. Absorption from the gastrointestinal tract occurs in the divalent and tetravalent forms. Permanganates, which are strong oxidizing agents, have a +7 valence. The principal organomanganese compound is the anti-knock additive, methylcyclopentadienyl manganese tricarbonyl. Manganese is a ubiquitous constituent of the environment comprising about 0.1% of the earth's crust. For the general population, food is the most important source of manganese with daily intake ranging from 2-9 mg Mn. Combustion of gasoline containing methylcyclopentadienyl manganese tricarbonyl releases submicron particles of Mn3O4 that are potentially respirable. Biomagnification of manganese in the food chain probably does not occur. The lungs and gastrointestinal tract absorb some manganese, but the relative amounts absorbed from each site are not known. Homeostatic mechanisms limit the absorption of manganese from the gastrointestinal tract. Elimination of manganese occurs primarily by excretion into the bile. Animal studies indicate that manganese is an essential co-factor for enzymes, such as hexokinase, superoxide dismutase, and xanthine oxidase. However, no case of manganese deficiency in humans has been identified. Manganism is a central nervous system disease first described in the 1800s following exposure to high concentrations of manganese oxides. Manganese madness was the term used to describe the initial psychiatric syndrome (compulsive behavior, emotional lability, hallucinations). More commonly, these workers developed a Parkinson's-like syndrome. Currently, the risks of exposure to low concentrations of manganese in the industrial and in the environmental settings (e.g., methylcyclopentadienyl manganese tricarbonyl in gasoline) are being evaluated with regards to the development of subclinical neuropsychological changes. The American Conference of Governmental and Industrial Hygienists recently lowered the TLV-TWA for manganese compounds and inorganic manganese compounds to 0.2 mg Mn/m3. PMID:10382563

Barceloux, D G

1999-01-01

6

Manganese partitioning in low carbon manganese steel during annealing  

SciTech Connect

For 6Mn16 steel experimental soft annealing at 625 deg. C for periods from 1 h to 60 h and modeling with Thermo-Calc were performed to estimate the partitioning of alloying elements, in particular Mn, between ferrite, cementite and austenite. Using transmission electron microscopy and X-ray analysis it was established that the increase of Mn concentration in carbides to a level 7%-11.2% caused a local decrease of the Ac{sub 1} temperature and led to the presence of austenite around the carbides. Thus, after cooling, small bainite-martensite or bainite-martensite-retained austenite (BM-A) islands were observed. A dispersion of carbides and a coarsening process were observed. The measured amount of Mn in the carbides was in good agreement with theoretical predictions.

Lis, J. [Institute of Materials Engineering, Czestochowa University of Technology, 19 Armii Krajowej, 42-200 Czestochowa (Poland); Lis, A. [Institute of Materials Engineering, Czestochowa University of Technology, 19 Armii Krajowej, 42-200 Czestochowa (Poland)], E-mail: lis@mim.pcz.czest.pl; Kolan, C. [Institute of Materials Engineering, Czestochowa University of Technology, 19 Armii Krajowej, 42-200 Czestochowa (Poland)

2008-08-15

7

Hot-working behaviour of high- manganese austenitic steels  

Microsoft Academic Search

Purpose: The work consisted in investigation of newly elaborated high-manganese austenitic steels with Nb and Ti microadditions in variable conditions of hot-working. Design\\/methodology\\/approach: Determination of processes controlling strain hardening was carried out in continuous compression test using Gleeble 3800 thermo-mechanical simulator. Findings: It was found that they have austenite microstructure with numerous annealing twins in the initial state. Continuous compression

L. A. Dobrza?ski a; A. Grajcar; W. Borek

8

Hot corrosion resistances of yttrium-implanted and unimplanted low-manganese–carbon steels  

Microsoft Academic Search

Yttrium-implanted and unimplanted low-manganese–carbon steel samples were analyzed at T=700°C and under an oxygen partial pressure PO2=0.04 Pa for 24 h to observe the yttrium implantation effect on sample hot corrosion resistance. The yttrium implantation effect on low-manganese–carbon steel was investigated using several analytical and structural techniques such as Rutherford backscattering spectrometry (RBS), X-ray photoelectron spectroscopy (XPS), reflection high energy

E Caudron; H Buscail

2000-01-01

9

Effect of titanium additions to low carbon, low manganese steels on sulphide precipitation  

Microsoft Academic Search

Recent developments of high strength line pipe steel have seen a decrease in carbon content from 0.25 wt% to less than 0.05 wt% and manganese to less than 1 wt% in an attempt to reduce centreline segregation. The sulphur content should be less than 0.008 wt% as well. However, recent papers argued that low manganese levels in pipeline steels have

Sima Aminorroaya-Yamini

2008-01-01

10

Comparison of the irradiated tensile properties of a high-manganese austenitic steel and type 16 stainless steel  

SciTech Connect

The USSR steel EP-838 is a high-manganese (13.5%), low-nickel (4.2%) steel that also has lower chromium and molybdenum than type 316 stainless steel. Tensile specimens of 20%-cold-worked EP-838 and type 316 stainless steel were irradiated in the High Flux Isotope Reactor (HFIR) at the coolant temperature (approx. 50/sup 0/C). A displacement damage level of 5.2 dpa was reached for the EP-838 and up to 9.5 dpa for the type 316 stainless steel. Tensile tests at room temperature and 300/sup 0/C on the two steels indicated that the irradiation led to increased strength and decreased ductility compared to the unirradiated steels. Although the 0.2% yield stress of the type 316 stainless steel in the unirradiated condition was greater than that for the EP-838, after irradiation there was essentially no difference between the strength or ductility of the two steels. The results indicate that the replacement of the majority of the nickel by manganese and a reduction of chromium and molybdenum in an austenitic stainless steel of composition near that for type 316 stainless steel has little effect on the irradiated and unirradiated tensile properties at low temperatures.

Klueh, R.L.; Grossbeck, M.L.

1983-01-01

11

Low Frequency-SAFT Inspection Methodology for Coarse-Grained Steel Rail Components (Manganese Steel Frogs)  

SciTech Connect

In the rail industry, sections of high strength Manganese steel are employed at critical locations in railroad networks. Ultrasonic inspections of Manganese steel microstructures are difficult to inspect with conventional means, as the propagation medium is highly attenuative, coarse-grained, anisotropic and nonhomogeneous in nature. Current in-service inspection methods are ineffective while pre-service X-ray methods (used for full-volumetric examinations of components prior to shipment) are time-consuming, costly, require special facilities and highly trained personnel for safe operations, and preclude manufacturers from inspecting statistically meaningful numbers of frogs for effective quality assurance. In-service examinations consist of visual inspections only and by the time a defect or flaw is visually detected, the structural integrity of the component may already be compromised, and immediate repair or replacement is required. A novel ultrasonic inspection technique utilizing low frequency ultrasound (100 to 500 kHz) combined with a synthetic aperture focusing technique (SAFT) for effective reduction of signal clutter and noise, and extraction of important features in the data, has proven to be effective for these coarse grained steel components. Results from proof-of-principal tests in the laboratory demonstrate an effective means to detect and localize reflectors introduced as a function of size and depth from the top of the frog rail. Using non-optimal, commercially available transducers coupled with the low-frequency/SAFT approach, preliminary evaluations were conducted to study the effects of the material microstructure on ultrasonic propagation, sensitivity and resolution in thick section frog components with machined side-drilled holes. Results from this study will be presented and discussed.

Diaz, Aaron A.; Andersen, Eric S.; Samuel, Todd J.

2004-11-01

12

Irradiation induced changes in the grain boundary chemistry of high-manganese low activation martensitic steels  

NASA Astrophysics Data System (ADS)

The effects of neutron irradiation (10 dpa at 638 K, FFTF/MOTA) on solute segregation to the grain boundaries in high-manganese martensitic steels were investigated using Auger electron spectroscopy (AES). The AES spectrum obtained from the grain boundaries in martensitic steels was significantly influenced by neutron irradiation. Neutron irradiation caused a marked increase in the amount of intergranular segregation of manganese in 12%Cr-6%Mn-1%W steel, while no significant increases in sulfur and/or phosphorus segregations were found in the steel. In 9%Cr-2%Mn-1%W steel, a large amount of silicon as well as a small amount of manganese segregation at grain boundaries was induced by the irradiation. The following mechanisms of irradiation induced embrittlement are proposed; (1) neutron irradiation induced intergranular segregation of manganese causes a reduction of grain boundary cohesive force, (2) intergranular segregation of silicon reduces carbon concentration at grain boundaries by a site competition mechanism resulting in the weakening of the grain boundary strength. Another possible explanation involves grain boundary precipitation.

Kimura, A.; Charlot, L. A.; Gelles, D. S.; Baer, D. R.; Jones, R. H.

1992-09-01

13

Behavior of nitrogen in a nitrogen-containing chromium-manganese steel during electroslag remelting  

NASA Astrophysics Data System (ADS)

Electroslag remelting of a high-alloyed steel with high contents of nitrogen, chromium, and manganese in an electroslag furnace has been studied. CaF2-MgO-SiO2 slag developed at TsNIITMASh and allowing remelting process at a temperature of 1520-1560°C is used as a flux. It is found that electroslag remelting of high-alloyed steels with a high nitrogen concentration does not change the nitrogen content.

Linchevskii, B. V.; Rigina, L. G.; Takhirov, A. A.

2013-06-01

14

Corrosion Behavior of Low Alloy Steels Containing Manganese in Mixed Chloride Sulfate Solution  

NASA Astrophysics Data System (ADS)

The corrosion resistance of the low alloy steels was improved by the addition of Mn up to 2.0 wt pct due to grain refinement and the formation of a protective rust layer. On the other hand, the addition of 5.0 wt pct manganese decreased the corrosion resistance of low alloy steel due to the microstructural changes that hinder the formation of the protective rust layer.

Nam, Nguyen Dang; Kim, Min Jun; Kim, Jung Gu

2013-09-01

15

Cumulative fatigue damage in low cycle fatigue and gigacycle fatigue for low carbon–manganese steel  

Microsoft Academic Search

Typical tee and pipe components are subjected to thermal and mechanical loading histories which are variable and divided into two different regimes: low cycle fatigue and high cycle fatigue in steam generator vessel of nuclear power plants.Carbon–manganese steel A42 are often used in such applications. In order to investigate the cumulative damage of low cycle fatigue and gigacycle fatigue, the

Zhi Yong Huang; Danièle Wagner; Claude Bathias; Jean Louis Chaboche

2011-01-01

16

Heat treatment of hot-worked P\\/M medium-manganese steels  

Microsoft Academic Search

The authors explore the possibility of improving the mechanical properties of hot-worked manganese steels alloyed with nominal amounts of molybdenum, tungsten, vanadium, and silicon by quenching performed directly after high-temperature thermomechanical processing and by additional heat treatment. The hot working was performed, using sintered blanks, by hot compression and hot extrusion. Data are given on tensile strength, fatigue limit, impact

K. E. Ananyan; V. Yu. Dorofeev; V. I. Chumakov

1987-01-01

17

Influence of processing on the cryogenic mechanical properties of high strength high manganese stainless steel  

SciTech Connect

New high strength structural steels have been required for the large superconducting magnets that will be used for the next step test facility for fusion reactor research. The new materials must have high yield strength accompanied with better toughness and better fatigue resistance compared with the conventional nitrogen-strengthened stainless steels such as AISI 304LN and 316LN that were used for the cases of the toroidal field coils for the Large Coil Project. A number of new high manganese austenitic steels have been proposed for new cryogenic structural alloys since they can offer low cost, stable austenite and high strength.

Ogawa, R.; Morris, J.W. Jr.

1983-08-01

18

Research of selected properties of two types of high manganese steel wires  

NASA Astrophysics Data System (ADS)

The article presents results of tests that aimed at establishing the impact of deformation on properties of wires made of two types of high manganese steels. The deformation process was carried out with the use of a draw bench machine at a speed of 0.5 m min-1. Mechanical properties and structure of strengthened and annealed wires for both steels at different levels of relative reduction in cross-section were determined. Strength of the tested materials was determined in the tensile test, while its hardness was measured with the Vickers hardness test method. Fractographic tests were performed using a scanning electron microscope. It was shown that at the beginning of tensile test, the investigated high manganese steels were characterized by very high plasticity and become stronger as the degree of deformation grows. Surfaces of fractures that were created in the areas where the sample was torn were analyzed. These fractures indicate the presence of transcrystalline ductile fractures.

Tomaszewska, A.; Jab?o?ska, M.; Hadasik, E.; Niewielski, G.; Kawalla, R.

2011-05-01

19

Manganese-Cobalt Mixed Spinel Oxides as Surface Modifiers for Stainless Steel Interconnects of Solid Oxide Fuel Cells  

Microsoft Academic Search

Ferritic stainless steels are promising candidates for interconnect applications in low- and mid-temperature solid oxide fuel cells (SOFCs). A couple of issues however remain for the particular application, including the chromium poisoning due to chromia evaporation, and long-term surface and electrical stability of the scale grown on these steels. Application of a manganese colbaltite spinel protection layer on the steels

Gordon Xia; Z Gary Yang; Jeffry W. Stevenson

2006-01-01

20

Aging properties of vanadium-bearing high manganese stainless steel  

SciTech Connect

Strengthening of austenitic ({gamma}) stainless steel is of great interest to utilization for the structural component. Strengthening of the steel is attained by a combination of following mechanisms such as solution strengthening, strengthening by grain size effect, strain hardening, and precipitation hardening. A selection for the strengthening of {gamma} steel is precipitation hardening due to carbides, nitrides, and intermetallic phases, by which both high strength and low permeability of {gamma} steel may be satisfied. Among Mo, Ti, V, and Nb carbides, it is known that vanadium carbide is considered to be potent contributor to hardening because it precipitates finely in the matrix and grow relatively slower. However, carbide precipitation hardening behavior of highly alloyed {gamma} stainless steel has not been much studied. In this paper, hardening behavior of the vanadium added, low permeability {gamma} stainless steel, Fe-Cr-6Ni-10Mn-V-C, was investigated focusing on the microstructural change and compositional aspects.

Haruna, Y. [Sanyo Special Steel Co., Ltd., Himeji (Japan). Technological Research Lab.; Yamamoto, A.; Tsubakino, H. [Himeji Inst. of Tech. (Japan). Dept. of Materials Science and Engineering

1997-11-01

21

Medium-Alloy Manganese-Rich Transformation-Induced Plasticity Steels  

NASA Astrophysics Data System (ADS)

The manganese concentration of steels which rely on transformation-induced plasticity is generally less than 2 wt pct. Recent work has highlighted the potential for strong and ductile alloys containing some 6 wt pct of manganese, but with aluminum additions in order to permit heat treatments which are amenable to rapid production. However, large concentrations of aluminum also cause difficulties during continuous casting. Alloy design calculations have been carried out in an effort to balance these conflicting requirements, while maintaining the amount of retained austenite and transformation kinetics. The results indicate that it is possible by adjusting the carbon and manganese concentrations to reduce the aluminum concentration, without compromising the mechanical properties or transformation kinetics. The deformation-induced transformation of retained austenite is explained quantitatively, for a range of alloys, in terms of a driving force which takes into account the very fine state of the retained austenite.

Suh, Dong Woo; Ryu, Joo Hyun; Joo, Min Sung; Yang, Hong Seok; Lee, Kyooyoung; Bhadeshia, H. K. D. H.

2013-01-01

22

A model for the silicon-manganese deoxidation of steel weld metals  

Microsoft Academic Search

From an analytical and theoretical study of flat and out-of-position gas metal arc (GMA) C-Mn steel welds containing varying\\u000a additions of silicon and manganese, we conclude that the buoyancy effect (flotation obeying Stokes’ law) does not play a significant\\u000a role in the separation of oxide inclusions during weld metal deoxidation. Consequently, the separation rate of the particles\\u000a is controlled solely

O. Grong; T. A. Siewert; G. P. Martins; D. L. Olson

1986-01-01

23

A model for the silicon-manganese deoxidation of steel weld metals  

Microsoft Academic Search

From an analytical and theoretical study of flat and out-of-position gas metal arc (GMA) C-Mn steel welds containing varying additions of silicon and manganese, we conclude that the buoyancy effect (flotation obeying Stokes' law) does not play a significant role in the separation of oxide inclusions during weld metal deoxidation. Consequently, the separation rate of the particles is controlled solely

O. Grong; T. A. Siewert; G. P. Martins; D. L. Olson

1986-01-01

24

Surface modifications induced by yttrium implantation on low manganese–carbon steel  

Microsoft Academic Search

Low manganese–carbon steel samples were ion implanted with yttrium. Sample compositions and structures were investigated before and after yttrium implantations to determine the yttrium distribution in the sample. Yttrium implantation effects were characterized using several analytical and structural techniques such as X-ray photoelectron spectroscopy, reflection high energy electron diffraction, X-ray diffraction, glancing angle X-ray diffraction and Rutherford backscattering spectrometry. In

E Caudron; H Buscail; V. A. C Haanapel; Y. P Jacob; M. F Stroosnijder

1999-01-01

25

Thermal Growth and Performance of Manganese Cobaltite Spinel Protection Layers on Ferritic Stainless Steel SOFC Interconnects  

Microsoft Academic Search

To protect solid oxide fuel cells (SOFCs) from chromium poisoning and improve metallic interconnect stability, manganese cobaltite spinel protection layers with a nominal composition of Mn1.5Co1.5O4 were thermally grown on Crofer22 APU, a ferritic stainless steel. Thermal, electrical and electrochemical investigations indicated that the spinel protection layers not only significantly decreased the contact area specific resistance (ASR) between a LSF

Zhenguo Yang; Guanguang Xia; Steven P. Simner; Jeffry W. Stevenson

2005-01-01

26

Structure and properties of low-carbon high-manganese cast steels for cryogenic use  

SciTech Connect

A low carbon content and a relatively high manganese/carbon ratio have a marked effect in promoting the toughness of Mn-C cast steels at low temperatures. In the case of a low carbon content, cast steel with an austenitic matrix containing epsilon-martensite has good mechanical properties at low temperatures. The advantage of the cast steel with a ..gamma.. + epsilon structure over that with a fully austenitic structure lies in the relatively lower alloy content (Cr, Al, Ni, and Mn) in the former, a content that at the same time imparts better casting behavior. The steels studied containing 19-22% have good low-temperature mechanical properties and are therefore suggested for cryogenic purposes.

Li, L.S.; Wayman, C.M.; Wei, G.S.; Yang, D.Z.

1982-12-01

27

The Formation of Manganese Sulphide Inclusions in Steel.  

National Technical Information Service (NTIS)

Theories to account for the occurrence of MnS inclusions in steel are based on possible Fe-Mn-S, Fe-Mn-S-O and Fe-Mn-S-C phase diagrams. Wherever possible, the conventional type I, II, III, IV sulphide nomenclature has been retained. The report is illustr...

I. G. Davies

1973-01-01

28

Manganese and nitrogen in stainless steel SMA welds for cryogenic service  

SciTech Connect

Evaluation of a shielded metal arc (SMA) weld test matrix in which manganese (1.5 to 10 wt-%) and nitrogen (0.04 to 0.26wt-%) were varied independently has clarified the effect of these elements on cryogenic mechanical properties and predicted ferrite number (FN). Several molybdenum and boron additions were also made, but they had no observable effect on strength or Charpy V-notch (CVN) absorbed energy. The matrix was based on a type 308L stainless steel weld metal composition. Desired compositions and constant FN were attained through alloy additions to the electrode coating. For each weld, one all-weld metal 4-K tensile specimen and five 76-K CVN impact specimens were tested. Increasing the nitrogen content from 0.05 to 0.25 wt-% linearly increased the 4-K yield strength from 600 to 1300 MPa (87 to 188.5 ksi) and decreased the 76-K lateral expansion from 0.6 to 0.1 mm (0.24 to 0.04 in.). Nitrogen reduced the 76-K CVN absorbed energy but not linearly. The addition of manganese slightly increased the yield strength and slightly decreased the lateral expansion. The 4-K tensile strength was relatively unaffected by alloy additions; values varied between 1300 and 1500 MPa (188.5 and 217.5 ksi). The DeLong FN predictive equation was improved by substituting the Szumachowski-Kotecki constant manganese term of 0.35 into the DeLong nickel equivalent. Analysis of the remaining FN deviation revealed an interaction between nitrogen and manganese. Addition of manganese-nitrogen interactive terms to the nickel equivalent increased the accuracy of the FN prediction.

Mc Cowan, C.N.; Siewart, T.A.; Reed, R.P.; Lake, F.B.

1987-03-01

29

Transformation Characteristics of Ferrite/Carbide Aggregate in Continuously Cooled, Low Carbon-Manganese Steels  

NASA Astrophysics Data System (ADS)

Transformation characteristics and morphological features of ferrite/carbide aggregate (FCA) in low carbon-manganese steels have been investigated. Work shows that FCA has neither the lamellae structure of pearlite nor the lath structure of bainite and martensite. It consists of a fine dispersion of cementite particles in a smooth ferrite matrix. Carbide morphologies range from arrays of globular particles or short fibers to extended, branched, and densely interconnected fibers. Work demonstrates that FCA forms over similar cooling rate ranges to Widmanstätten ferrite. Rapid transformation of both phases occurs at temperatures between 798 K and 973 K (525 °C and 700 °C). FCA reaction is not simultaneous with Widmanstätten ferrite but occurs at temperatures intermediate between Widmanstätten ferrite and bainite. Austenite carbon content calculations verify that cementite precipitation is thermodynamically possible at FCA reaction temperatures without bainite formation. The pattern of precipitation is confirmed to be discontinuous. CCT diagrams have been constructed that incorporate FCA. At low steel manganese content, Widmanstätten ferrite and bainite bay sizes are significantly reduced so that large amounts of FCA are formed over a wide range of cooling rates.

Di Martino, S. F.; Thewlis, G.

2013-10-01

30

Ennoblement of Stainless Steel by the Manganese-Depositing Bacterium Leptothrix discophora  

PubMed Central

The noble shift in open-circuit potential exhibited by microbially colonized stainless steel (ennoblement) was investigated by examining the relationship among surface colonization, manganese deposition, and open-circuit potential for stainless steel coupons exposed to batch cultures of the manganese-depositing bacterium Leptothrix discophora. Open-circuit potential shifted from -100 to +330 mV(infSCE) as a biofilm containing 75 nmol of MnO(infx) cm(sup-2) formed on the coupon surface but changed little further with continued MnO(infx) deposition up to 270 nmol cm(sup-2). Increased open-circuit potential corresponded to decreasing Mn(II) concentration in solution and to increased MnO(infx) accumulation and attached cell density on the coupon surfaces. MnO(infx) deposition was attributable to biological activity, and Mn(II) was observed to enhance cell attachment. The experimental results support a mechanism of ennoblement in which open-circuit potential is fixed near +350 mV(infSCE) by the cathodic activity of biomineralized MnO(infx).

Dickinson, W. H.; Caccavo, F.; Olesen, B.; Lewandowski, Z.

1997-01-01

31

Thermal Growth and Performance of Manganese Cobaltite Spinel Protection Layers on Ferritic Stainless Steel SOFC Interconnects  

SciTech Connect

To protect solid oxide fuel cells (SOFCs) from chromium poisoning and improve metallic interconnect stability, manganese cobaltite spinel protection layers with a nominal composition of Mn1.5Co1.5O4 were thermally grown on Crofer22 APU, a ferritic stainless steel. Thermal, electrical and electrochemical investigations indicated that the spinel protection layers not only significantly decreased the contact area specific resistance (ASR) between a LSF cathode and the stainless steel interconnect, but also inhibited the sub-scale growth on the stainless steel by acting as a barrier to the inward diffusion of oxygen. A long-term thermal cycling test demonstrated excellent structural and thermomechanical stability of these spinel protection layers, which also acted as a barrier to outward chromium cation diffusion to the interconnect surface. The reduction in the contact ASR and prevention of Cr migration achieved by application of the spinel protection layers on ferritic stainless steel resulted in improved stability and electrochemical performance of SOFCs.

Yang, Zhenguo; Xia, Guanguang; Simner, Steven P.; Stevenson, Jeffry W.

2005-08-01

32

Effect of sulfur on rolling contact fatigue life of high-manganese precipitation-hardening austenitic steel  

Microsoft Academic Search

For mechanical components used in high magnetic flux such as bearings and shafts that undergo cyclic stress, materials require low permeability with high strength, hardness, appropriate machinability, and good fatigue properties. Although it is implied that low permeability and machinability will be achieved by a selection of sulfurized austenitic (γ) steel grades, effect of manganese sulfide (MnS) on fatigue properties

Y. Haruna; A. Yamamoto; H. Tsubakino

1998-01-01

33

Cryogenic S-N Fatigue and Fatigue Crack Propagation Behaviors of High Manganese Austenitic Steels  

NASA Astrophysics Data System (ADS)

In the current study, the S-N fatigue and the fatigue crack propagation (FCP) behaviors of high manganese austenitic steels, including Fe24Mn and Fe22Mn, were studied, and the results were compared with STS304 (Fe-1Si-2Mn-20Cr-10Ni). The S-N fatigue tests were conducted at 298 K and 110 K (25 °C and -163 °C), respectively, and at an R ratio of 0.1 under a uniaxial loading condition. The FCP tests were conducted at 298 K and 110 K (25 °C and -163°C), respectively, and at R ratios of 0.1 and 0.5, respectively, using compact tension specimens. The resistance to S-N fatigue of each specimen increased greatly with decreasing temperature from 298 K to 110 K (25 °C to -163 °C) and showed a strong dependency on the flow stress. The FCP behaviors of the austenitic steels currently studied substantially varied depending on testing temperature, applied ? K (stress intensity factor range), and R ratio. The enhanced FCP resistance was observed for the Fe24Mn and the Fe22Mn specimens particularly in the near-threshold ? K regime, while the enhancement was significant over the entire ? K regimes for the STS304 specimen, with decreasing temperature from 298 K to 110 K (25 °C to -163 °C). The S-N fatigue and the FCP behaviors of high manganese austenitic steels are compared with STS304 and discussed based on the fractographic and the micrographic observations.

Jeong, Dae-Ho; Lee, Soon-Gi; Jang, Woo-Kil; Choi, Jong-Kyo; Kim, Young-Ju; Kim, Sangshik

2013-10-01

34

Influence of Aluminum Alloying and Heating Rate on Austenite Formation in Low Carbon-Manganese Steels  

NASA Astrophysics Data System (ADS)

This investigation focuses on the austenite formation process during continuous heating, over a wide range of heating rates (0.05 to 20 K/s), in three low carbon-manganese steels alloyed with different levels of aluminum (0.02, 0.48, and 0.94, wt pct Al). High resolution dilatometry, combined with metallographic observations, was used to determine the starting ( Ac 1) and finishing ( Ac 3) temperatures of this transformation. It is shown that both the aluminum content and the applied heating rate have a strong influence on this process. During fast heating (>1 K/s), the pearlite phase present in the initial microstructure remains almost unaffected up to temperature Ac 1. On the contrary, during slow heating, cementite lamellas inside pearlite partially dissolve, this dissolution effect being more pronounced for the lower carbon and higher aluminum content steels. The changes in the initial microstructure during slow heating affect the austenite nucleation and growth processes. Furthermore, in the aluminum alloyed steels, slow heating conditions shift the Ac 3 temperature to higher values. This shift is suggested to be due to aluminum partitioning from austenite to ferrite, which stabilizes ferrite and delays its transformation to higher temperatures. Thermodynamic calculations carried out with MTDATA software seem to support some of the experimental observations carried out under very low heating conditions close to equilibrium (0.05 K/s).

San Martín, D.; Palizdar, Y.; García-Mateo, C.; Cochrane, R. C.; Brydson, R.; Scott, A. J.

2011-09-01

35

Microstructural characterization of high-manganese austenitic steels with different stacking fault energies  

SciTech Connect

Microstructures of tensile-deformed high-manganese austenitic steels exhibiting twinning-induced plasticity were analyzed by electron backscatter diffraction pattern observation and X-ray diffraction measurement to examine the influence of differences in their stacking fault energies on twinning activity during deformation. The steel specimen with the low stacking fault energy of 15 mJ/m{sup 2} had a microstructure with a high population of mechanical twins than the steel specimen with the high stacking fault energy (25 mJ/m{sup 2}). The <111> and <100> fibers developed along the tensile axis, and mechanical twinning occurred preferentially in the <111> fiber. The Schmid factors for slip and twinning deformations can explain the origin of higher twinning activity in the <111> fiber. However, the high stacking fault energy suppresses the twinning activity even in the <111> fiber. A line profile analysis based on the X-ray diffraction data revealed the relationship between the characteristics of the deformed microstructures and the stacking fault energies of the steel specimens. Although the variation in dislocation density with the tensile deformation is not affected by the stacking fault energies, the effect of the stacking fault energies on the crystallite size refinement becomes significant with a decrease in the stacking fault energies. Moreover, the stacking fault probability, which was estimated from a peak-shift analysis of the 111 and 200 diffractions, was high for the specimen with low stacking fault energy. Regardless of the difference in the stacking fault energies of the steel specimens, the refined crystallite size has a certain correlation with the stacking fault probability, indicating that whether the deformation-induced crystallite-size refinement occurs depends directly on the stacking fault probability rather than on the stacking fault energies in the present steel specimens. - Highlights: {yields} We studied effects of stacking fault energies on deformed microstructures of steels. {yields} Correlations between texture and occurrence of mechanical twinning are discussed. {yields} Evolutions of dislocations and crystallite are analyzed by line profile analysis.

Sato, Shigeo, E-mail: s.sato@imr.tohoku.ac.jp [Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan); Kwon, Eui-Pyo [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577 (Japan); Imafuku, Muneyuki [Faculty of Engineering, Tokyo City University, Tokyo 158-8557 (Japan); Wagatsuma, Kazuaki [Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan); Suzuki, Shigeru [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577 (Japan)

2011-08-15

36

Effects of laser-shock processing on the microstructure and surface mechanical properties of hadfield manganese steel  

Microsoft Academic Search

The effects of laser-shock processing (LSP) on the microstructure, hardness, and residual stress of Hadfield manganese (1\\u000a pct C and 14 pct Mn) steels were studied. Laser-shock processing was performed using a Nd: glass phosphate laser with 600\\u000a ps pulse width and up to 120 J\\/pulse energy at power density above 1012 W\\/cm2. The effects of cold rolling and shot

J. P. Chu; J. M. Rigsbee; G. Bana?; F. V. Lawrence; H. E. Elsayed-Ali

1995-01-01

37

Levels of Arsenic, Cadmium, Lead, Manganese and Zinc in Biological Samples of Paralysed Steel Mill Workers with Related to Controls  

Microsoft Academic Search

The determination of essential trace and toxic elements in the biological samples of human beings is an important clinical\\u000a screening procedure. This study aimed to assess the possible effects of environmental exposure on paralysed male workers (n?=?75) belonging to the production and quality control departments of a steel mill. In this investigation, the concentrations\\u000a of arsenic, cadmium, lead, manganese and

Hassan Imran Afridi; Tasneem Gul Kazi; Atif G. Kazi; Faheem Shah; Sham Kumar Wadhwa; Nida Fatima Kolachi; Abdul Qadir Shah; Jameel Ahmed Baig; Naveed Kazi

38

Effect of sulfur on rolling contact fatigue life of high-manganese precipitation-hardening austenitic steel  

SciTech Connect

For mechanical components used in high magnetic flux such as bearings and shafts that undergo cyclic stress, materials require low permeability with high strength, hardness, appropriate machinability, and good fatigue properties. Although it is implied that low permeability and machinability will be achieved by a selection of sulfurized austenitic ({gamma}) steel grades, effect of manganese sulfide (MnS) on fatigue properties of such grades especially for bearing applications is not clarified. For high-carbon chromium bearing steels, the effect of MnS on rolling contact fatigue life of the steels containing sulfur less than 0.03% are discussed. In these studies, the effect of MnS is not clearly determined whether it is beneficial or harmful to contact fatigue lives of the steels. However, effect of MnS under higher sulfur content, i.e., 0.10%, on the fatigue properties of {gamma} steel has not been studied. In this paper, the effect of sulfur on rolling contact fatigue properties of vanadium added {gamma} steel, 10Cr-6Ni-8Mn-1.6V-0.6C, was investigated focusing on microstructural change in connection with MnS particles.

Haruna, Y. [Sanyo Special Steel Co., Ltd., Himeji (Japan). Technological Research Lab.; Yamamoto, A.; Tsubakino, H. [Himeji Inst. of Tech. (Japan)

1998-10-05

39

Elevated Airborne Exposures of Teenagers to Manganese, Chromium, and Iron from Steel Dust and New York City's Subway System  

PubMed Central

There is increasing interest in potential health effects of airborne exposures to hazardous air pollutants at relatively low levels. This study focuses on sources, levels, and exposure pathways of manganese, chromium, and iron among inner-city high school students in New York City (NYC) and the contribution of subways. Samples of fine particulate matter (PM2.5) were collected during winter and summer over 48 h periods in a variety of settings including inside homes, outdoors, and personal samples (i.e., sampling packs carried by subjects). PM2.5 samples were also collected in the NYC subway system. For NYC, personal samples had significantly higher concentrations of iron, manganese, and chromium than did home indoor and ambient samples. The ratios and strong correlations between pairs of elements suggested steel dust as the source of these metals for a large subset of the personal samples. Time–activity data suggested NYC subways as a likely source of these elevated personal metals. In duplicate PM2.5 samples that integrated 8 h of underground subway exposure, iron, manganese, and chromium levels (>2 orders of magnitude above ambient levels) and their ratios were consistent with the elevated personal exposures. Steel dust in the NYC subway system was the dominant source of airborne exposures to iron, manganese, and chromium for many young people enrolled in this study, with the same results expected for other NYC subway riders who do not have occupational exposures to these metals. However, there are currently no known health effects at the exposure levels observed in this study.

CHILLRUD, STEVEN N.; EPSTEIN, DAVID; ROSS, JAMES M.; SAX, SONJA N.; PEDERSON, DEE; SPENGLER, JOHN D.; KINNEY, PATRICK L.

2011-01-01

40

Some characteristics of structure formation in manganese cast irons and steels  

Microsoft Academic Search

1.Manganese lowers the solubility of carbon in the melt, while austenite raises the eutectic equilibrium temperature and shifts the eutectic point toward lower carbon concentrations.2.With a high manganese concentration in cast iron the shift of the eutectic point leads to a sharp change in the ratio of phases and their composition. The amount of cementite is insufficient for the formation

G. I. Sil'man; N. I. Pristuplyuk; M. S. Frol'tsov

1977-01-01

41

Investigation of the Delayed Fracture Phenomenon in Deep-Drawn Austenitic Manganese-Based Twinning-Induced Plasticity Steels  

NASA Astrophysics Data System (ADS)

The phenomenon of delayed fracture in three austenitic manganese-based Twinning-Induced Plasticity steels is investigated by means of video observation and magnetic measurements. Delayed fracture is observed in the direction perpendicular to the rolling direction, in coincidence with the highest ?'-martensite fraction in a deep-drawn cup. The formation of a small fraction of ?'-martensite, irrespective of the chemical composition examined, is indicative of the formation of crack initiation sites. We propose an intermittent crack propagation concept and model for the phenomenon of delayed fracture.

van Tol, R. T.; Zhao, L.; Bracke, L.; Kömmelt, P.; Sietsma, J.

2013-10-01

42

Effects of annealing conditions on microstructure and mechanical properties of low carbon, manganese transformation-induced plasticity steel  

Microsoft Academic Search

The effects of annealing conditions on microstructural evolution and mechanical properties have been investigated in low carbon,\\u000a manganese TRIP (Mn TRIP) steel based on a 0.12C-6Mn-0.5Si-3Al alloy system. The microstructure of cold-rolled sheet subjected\\u000a to annealing at 760 °C to 800 °C for 30 s to 1800 s consists of a recrystallized ferrite matrix and fine-grained austenite\\u000a with a phase

Jae-Myeong Jang; Sung-Joon Kim; Nam Hyun Kang; Kyung-Mox Cho; Dong-Woo Suh

2009-01-01

43

Manganese-Cobalt Mixed Spinel Oxides as Surface Modifiers for Stainless Steel Interconnects of Solid Oxide Fuel Cells  

SciTech Connect

Ferritic stainless steels are promising candidates for interconnect applications in low- and mid-temperature solid oxide fuel cells (SOFCs). A couple of issues however remain for the particular application, including the chromium poisoning due to chromia evaporation, and long-term surface and electrical stability of the scale grown on these steels. Application of a manganese colbaltite spinel protection layer on the steels appears to be an effective approach to solve the issues. For an optimized performance, Mn{sub 1+x}Co{sub 2-x}O{sub 4} (-1 {le} x {le} 2) spinels were investigated against properties relative for protection coating applications on ferritic SOFC interconnects. Overall it appears that the spinels with x around 0.5 demonstrate a good CTE match to ceramic cell components, a relative high electrical conductivity, and a good thermal stability up to 1,250 C. This was confirmed by a long-term test on the Mn{sub 1.5}Co{sub 1.5}O{sub 4} protection layer that was thermally grown on Crofer22 APU, indicating the spinel protection layer not only significantly decreased the contact resistance between a LSF cathode and the stainless steel interconnects, but also inhibited the sub-scale growth on the stainless steels.

Xia, Gordon; Yang, Z Gary; Stevenson, Jeffry W.

2006-11-06

44

Spatially resolved X-ray diffraction mapping of phase transformations in the heat-affected zone of carbon-manganese steel arc welds  

Microsoft Academic Search

Phase transformations that occur in the heat-affected zone (HAZ) of gas tungsten arc welds in AISI 1005 carbon-manganese steel\\u000a were investigated using spatially resolved X-ray diffraction (SRXRD) at the Stanford Synchrotron Radiation Laboratory. In situ SRXRD experiments were performed to probe the phases present in the HAZ during welding of cylindrical steel bars. These real-time\\u000a observations of the phases present

John W. Elmer; Joe Wong; Thorsten Ressler

2001-01-01

45

Circumferential Hot Wire TIG Cladding of Carbon-Manganese Steel with Inconel 625 and Gun-Metal with a Tin Bronze.  

National Technical Information Service (NTIS)

It is demonstrated that the hot wire TIG process can dramatically increase the deposition rate of weld metal for cladding (and also for thick section joints) of carbon-manganese steel with Inconel 625 to a high quality. The Union Carbide manufactured faci...

F. J. Plumb K. M. Chipperfield

1985-01-01

46

Investigation on Pitting Corrosion of Nickel-Free and Manganese-Alloyed High-Nitrogen Stainless Steels  

NASA Astrophysics Data System (ADS)

Pitting corrosion behavior of three kinds of nickel-free and manganese-alloyed high-nitrogen (N) stainless steels (HNSSs) was investigated using electrochemical and immersion testing methods. Type 316L stainless steel (316L SS) was also included for comparison purpose. Both solution-annealed and sensitization-treated steels were examined. The solution-annealed HNSSs showed much better resistance to pitting corrosion than the 316L SS in both neutral and acidic sodium chloride solutions. The addition of molybdenum (Mo) had no further improvement on the pitting corrosion resistance of the solution-annealed HNSSs. The sensitization treatment resulted in significant degradation of the pitting corrosion resistance of the HNSSs, but not for the 316L SS. Typical large size of corrosion pits was observed on the surface of solution-annealed 316L SS, while small and dispersed corrosion pits on the surfaces of solution-annealed HNSSs. The sensitization-treated HNSSs suffered very severe pitting corrosion, accompanying the intergranular attack. The addition of Mo significantly improved the resistance of the sensitization-treated HNSSs to pitting corrosion, particularly in acidic solution. The good resistance of the solution-annealed HNSSs to pitting corrosion could be attributed to the passive film contributed by N, Cr, and Mo. The sensitization treatment degraded the passive film by decreasing anti-corrosion elements and Cr-bearing oxides in the passive film.

Wu, Xinqiang; Fu, Yao; Huang, Junbo; Han, Enhou; Ke, Wei; Yang, Ke; Jiang, Zhouhua

2009-04-01

47

Characterization and Prediction of Flow Behavior in High-Manganese Twinning Induced Plasticity Steels: Part I. Mechanism Maps and Work-Hardening Behavior  

NASA Astrophysics Data System (ADS)

Thermodynamic stacking fault energy (SFE) maps were developed using the subregular solution model for the Fe-Mn-Al-C system. These maps were used to explain the variations in the work-hardening behavior of high-manganese steels, both through experiments and by comparison with the published data. The suppression of the transformation induced plasticity (TRIP) mechanism, the similarity between the shape of the work-hardening rate diagrams for the produced iso-SFE materials, and an earlier onset of stage C of work hardening by decreasing SFE were shown to be efficiently predictable by the given mechanism maps. To overcome the limitations arising from studying the deformation response of high-manganese steels by SFE values alone, for example, the different work-hardening rate of iso-SFE materials, an empirical criterion for the occurrence of short-range ordering (SRO) and the consequently enhanced work-hardening, was proposed. The calculated values based on this criterion were superimposed on the thermodynamics-based mechanism maps to establish a more accurate basis for material design in high-manganese iron-based systems. Finally, the given methodology is able to clarify the work-hardening behavior of high-manganese twinning induced plasticity (TWIP) steels across an extensive range of chemical compositions.

Saeed-Akbari, A.; Mosecker, L.; Schwedt, A.; Bleck, W.

2012-05-01

48

Mild steels coated with 14% manganese covered electrodes (E7-UM-200-K and E1-UM-350): Phenomena at the steel-coating interface  

SciTech Connect

In this work the authors have studied the phenomena in the interface of the coating made on soft carbon steel with electrodes with a high content of manganese. The study has been done with scanning electron microscope and X-rays mapping images. These images show how the alloy elements are distributed in each of the constituent elements presented in the interface, and the nature of these constituents. These results have allowed us to verify that many of the problems that arise in homogeneous joints, as such localised corrosion, low interface resistance, etc., happened, precisely in these regions. As a help to determine the nature of the constituent elements, microhardness measurements have also been made.

Molleda, F. [Escuela Tecnica Superior de Ingenieros Navales de Madrid (UPM) (Spain)]. E-mail: fmolleda@etsin.upm.es; Mora, J. [Escuela Tecnica Superior de Ingenieros Navales de Madrid (UPM) (Spain); Molleda, F.J. [ESAB Iberica (Spain); Carrillo, E. [Escuela Tecnica Superior de Ingenieros Navales de Madrid (UPM) (Spain); Mora, E. [Escuela Tecnica Superior de Ingenieros Navales de Madrid (UPM) (Spain); Mellor, B.G. [University of Southampton (United Kingdom)

2006-12-15

49

Differentiated treatment to obtain naturally reinforced surface layers on manganese steels  

Microsoft Academic Search

1.Laser hardening using the method selected reduces the microhardness of steels with a primarily a-martensitic structure but increases it in steels with a structure of metastable austenite. The maximum microhardness is obtained after laser treatment of previously hardened G14 steel, in which austenite is least stable in loading.2.Preliminary plastic deformation has a dissimilar influence on the microhardness of laser treated

L. S. Malinov; E. Ya. Kharlanova; M. V. Tumanova; A. V. Lisakovich; E. B. Lokshina

1991-01-01

50

Electron spectroscopy for chemical analysis study of corrosion films formed on manganese stainless steels  

SciTech Connect

Films formed on two grades of Mn stainless steels in 1 M hydrochloric acid (HCl) freely exposed to air at different potentials were examined using electron spectroscopy for chemical analysis (ESCA). The Cr content of the film, which is related closely to corrosion resistance of the base alloys, was lower within the films formed on Mn stainless steels as compared to a normal type 304 (UNS S30400) stainless steels. The film also contained significant amounts of Mn, Ni, and Cu. It was proposed that the presence o higher amounts of Mn, an electrochemically active element, with Cu resulted in poor passivation behavior of the present high Mn stainless steels.

Raja, V.S.; Devasenapathi, A.; Veluchamy, P.; Minoura, H.

1999-12-01

51

Corrosion properties of austenitic Cr-Mn-Ni-N steels with various manganese concentrations  

NASA Astrophysics Data System (ADS)

The structure and corrosion properties of two high-nitrogen 05Kh20AN8MF steels additionally alloyed with 9 and 17% Mn have been studied. Metallographic, X-ray diffraction, and fractographic studies show that both steels have an austenitic structure and high plasticity properties after quenching from 1100 and 1100°C and subsequent aging at 500°C for 2 h. The steel alloyed with 9% Mn and 0.58% V exhibit a higher strength. Both steels have a higher corrosion resistance in a 3.5% NaCl aqueous solution than 12Kh18N9T steel. After aging at 400 600°C, the corrosion rate and the sensitivity to stress corrosion cracking increase.

Berezovskaya, V. V.; Kostina, M. V.; Blinov, E. V.; Bannykh, I. O.; Bobrova, V. E.; Mel'Nik, V. P.

2008-02-01

52

Effects of laser-shock processing on the microstructure and surface mechanical properties of Hadfield manganese steel  

SciTech Connect

The effects of laser-shock processing (LSP) on the microstructure, hardness, and residual stress of Hadfield manganese (1 pct C and 14 pct Mn) steels were studied. Laser-shock processing was performed using a Nd:glass phosphate laser with 600 ps pulse width and up to 120 J/pulse energy at power density above 10{sup 12}W/cm{sup 2}. The effects of cold rolling and shot peening were also studied for comparison. Laser-shock processing caused extensive formation of {var_epsilon} hexagonal close-packed (hcp) martensite (35 vol pct), producing up to a 130 pct increase of surface hardness. The surface hardness increase was 40 to 60 pct for the shot-peened specimen and about 60 pct for the cold-rolled specimen. The LSP strengthening effect on Hadfield steel was attributed to the combined effects of the partial dislocation/stacking fault arrays and the grain refinement due to the presence of the {var_epsilon}-hcp martensite. For the cold-rolled and shot-peened specimens, the strengthening was a result of {var_epsilon}-hcp martensite and twins with dislocation effects, respectively. Shot peening resulted in a relatively higher compressive residual stress throughout the specimen than LSP.

Chu, J.P. [National Taiwan Ocean Univ., Keelung (Taiwan, Province of China). Inst. of Materials Engineering; Rigsbee, J.M. [Univ. of Alabama, Birmingham, AL (United States). Dept. of Materials Science and Engineering; Banas, G.; Lawrence, F.V. [Univ. of Illinois, Urbana, IL (United States). Dept. of Civil Engineering; Elsayed-Ali, H.E. [Old Dominion Univ., Norfolk, VA (United States). Dept. of Electrical and Computer Engineering

1995-06-01

53

Levels of arsenic, cadmium, lead, manganese and zinc in biological samples of paralysed steel mill workers with related to controls.  

PubMed

The determination of essential trace and toxic elements in the biological samples of human beings is an important clinical screening procedure. This study aimed to assess the possible effects of environmental exposure on paralysed male workers (n?=?75) belonging to the production and quality control departments of a steel mill. In this investigation, the concentrations of arsenic, cadmium, lead, manganese and zinc were determined in biological samples (blood, urine and scalp hair samples) of exposed paralysis and non-paralysed steel mill workers. For comparative purposes, unexposed healthy subjects of same age group were selected as referents. The elements in the biological samples were measured by atomic absorption spectrophotometry prior to microwave-assisted acid digestion. The validity of the methodology was checked by the biological certified reference materials. The results indicate that the level understudy elements in all three biological samples were significantly higher in paralysed workers of both groups (quality control and production) as compared to referents (p?

Afridi, Hassan Imran; Kazi, Tasneem Gul; Kazi, Atif G; Shah, Faheem; Wadhwa, Sham Kumar; Kolachi, Nida Fatima; Shah, Abdul Qadir; Baig, Jameel Ahmed; Kazi, Naveed

2011-05-06

54

Effect of Hydrogen on Structural Strength of High-Nitrogen Chromium–Manganese Steels  

Microsoft Academic Search

To increase the crack resistance of tire materials in hydrogen media, one adds admixtures of lanthanum (up to 0.05 vol. %) and cerium (up to 0.1 vol. %) to nitrogen-containing 18Mn-4Cr and 18Mn-18Cr steels in the process of experimental melting to refine, modify, and alloy these steels. These admixtures have a positive effect on the amount, form, and uniformity of

O. I. Balyts'kyi

2000-01-01

55

In-situ X-ray diffraction study of the behaviour of yttrium implanted low manganese-carbon steel at high temperature  

Microsoft Academic Search

Yttrium implanted and unimplanted low manganese-carbon steel samples were analysed at T=700°C and under oxygen partial pressure (Po2=0.04 Pa) for 24 h to show the yttrium implantation effect on sample oxidation resistance at high temperature. Weight gains resulting from sample oxidation were studied by thermogravimetry and structural analyses were performed by in-situ high temperature X-ray diffraction under the same experimental

E Caudron; H Buscail; R Cueff

2000-01-01

56

46 CFR 56.60-5 - Steel (High temperature applications).  

Code of Federal Regulations, 2011 CFR

...carbon steel, plain nickel-alloy steel, carbon-manganese-alloy steel, manganese-vanadium-alloy steel, and carbon-silicon steel may convert to graphite. (b) (Reproduces 124.2.B.) Upon prolonged exposure to temperatures above...

2011-10-01

57

46 CFR 56.60-5 - Steel (High temperature applications).  

Code of Federal Regulations, 2012 CFR

...carbon steel, plain nickel-alloy steel, carbon-manganese-alloy steel, manganese-vanadium-alloy steel, and carbon-silicon steel may convert to graphite. (b) (Reproduces 124.2.B.) Upon prolonged exposure to temperatures above...

2012-10-01

58

Constitutive Modeling of the Mechanical Properties of V-added Medium Manganese TRIP Steel  

NASA Astrophysics Data System (ADS)

In this study, medium Mn transformation-induced plasticity steel with the composition Fe-0.08 pct C-6.15 pct Mn-1.5 pct Si-2.0 pct Al-0.08 pct V was investigated. After intercritical annealing at 1013 K (740 °C), the steel contained coarse-grained ferrite and two ultrafine-grained (UFG) phases: ferrite and retained austenite. The material did not deform by localized Lüders band propagation: it did not suffer from this major problem as most UFG steels do. Localization of plastic flow was shown to be suppressed because of a combination of factors, including a bimodal grain size distribution, a multiphase microstructure, the presence of nanosized vanadium carbide precipitates, and the occurrence of the deformation-induced martensitic transformation of retained austenite. A constitutive model incorporating these effects was developed. The model was used to identify the factors which can lead to a further improvement of the mechanical properties of the UFG medium Mn TRIP steels.

Lee, Seawoong; Estrin, Yuri; De Cooman, Bruno C.

2013-07-01

59

MATHEMATICAL MODEL OF THE LD STEEL DEOXIDATION KINETICS WITH MANGANESE AND ALUMINIUM  

Microsoft Academic Search

The paper presents the mathematical model of the kinetics of the electric arc furnace steel deoxidation with Mn and Al. Based on the solving of the kinetics model differential equations, the variation of the deoxidants solubility during the deoxidation process can be determined, as well as the kinetic constants of the reactions and the maximum durations which are necessary for

Alexandru IVANESCU; Lilica IVANESCU; Elisabeta VASILESCU

60

Microstructural and mechanical effects of nickel and manganese on high strength steel weld metals  

Microsoft Academic Search

Neural network modelling suggested that the impact strength of high-strength steel weld metals could be increased at moderate expense to yield strength once Ni additions are made in a controlled manner with respect to Mn. Based on these predictions, shielded metal arc welding was used to prepare weld metals with Ni at 7 and 9 wt. % while Mn was

E. Keehan; H. O. Andrén; L. Karlsson; M. Murugananth; H. K. D. H. Bhadeshia

61

Effect of high-temperature thermomechanical treatment on the corrosion cracking of aging austenitic manganese steel  

SciTech Connect

On the basis of structural and fractographic investigations the article analyzes the causes of the favorable effect of high-temperature thermomechanical treatment on the corrosion resistance of austenitic aging steel 08G20M3F2 under stress in 3% aqueous solution of sodium chloride. A subgrain structure formed as a result of treatment in the steel and some curving of the grain boundary was encountered. Hot plastic deformation with subsequent carbide aging at 650/sub 0/C led to increased resistance to corrosion cracking of samples with a previously induced fatigue crack in the solution in comparison with samples subjected to hardening and aging to the same strength. The increased corrosion resistance under stress was ascribed to more difficult crack propagation along wavy grain boundaries and the ramification of the crack along the subgrain boundaries.

Vasechkina, T.P.; Sagaradze, V.V.; Pecherkina, N.L.; Filippov, Yu.I.

1988-05-01

62

Tensile, Fracture, and Fatigue Crack Growth Rate Behavior of High Manganese Steels  

SciTech Connect

Mechanical low temperature investigations were carried out to determine the cryogenic mechanical properties of newly developed Fe-Cr-Mn alloys with contents of chromium between 5 % and 10 % and manganese between 30 % and 40 % under the Project G-811, Russia. The final products were forged, rolled, and solution heat treated to obtain appropriate plate sizes necessary for the mechanical measurements. The tensile properties of these alloys determined between 4 K and 7 K show for certain alloy combination high elongation values at fracture of greater than 50 % with considerable high yield strengths around 900 MPa. The measured fracture toughness values with small scale compact tension specimens using elastic plastic J-tests show KIC data between 100 MPa{radical}m and 220 MPa{radical}m according to the alloy combination. Fatigue crack growth rate (FCGR) measurements of these alloys result also in some alloy combination case, high resistance against crack propagation with measured Paris coefficients of m {approx} 5 and C {approx} 8.5 E-13 mm/cycle. Thermal expansion of these alloys has been also determined resulting in values between 1600 {mu}m/m and 1700 {mu}m/m expansion from 5 K to 290 K.

Nyilas, A.; Weiss, K. [Forschungszentrum Karlsruhe, ITP, Karlsruhe (Germany); Grikurov, G.; Zoidze, N. [F. N. Tavazde Institute of Metallurgy and Materials Science, Georgian Academy of Sciences, Tbilisi (Georgia)

2006-03-31

63

Mapping Phase Transformations in the Heat-Affected-Zone of Carbon Manganese Steel Welds using Spatially Resolved X-Ray Diffraction  

SciTech Connect

Spatially Resolved X-Ray Diffraction (SRXRD) was used to investigate phase transformations that occur in the heat affected zone (HAZ) of gas tungsten arc (GTA) welds in AISI 1005 carbon-manganese steel. In situ SRXRD experiments performed at the Stanford Synchrotron Radiation Laboratory (SSRL) probed the phases present in the HAZ during welding, and these real-time observations of the HAZ phases were used to construct a map of the phase transformations occurring in the HAZ. This map identified 5 principal phase regions between the liquid weld pool and the unaffected base metal for the carbon-manganese steel studied in this investigation. Regions of annealing, recrystallization, partial transformation and complete transformation to {alpha}-Fe, {gamma}-Fe, and {delta}-Fe phases were identified using SRXRD, and the experimental results were combined with a heat flow model of the weld to investigate transformation kinetics under both positive and negative temperature gradients in the HAZ. From the resulting phase transformation map, the kinetics of phase transformations that occur under the highly non-isothermal heating and cooling cycles produced during welding of steels can now be better understood and modeled.

Elmer, J W; Wong, J; Ressler, T; Palmer, T A

2001-12-04

64

Control of cryogenic intergranular fracture in high-manganese austenitic steels  

SciTech Connect

The sources of cryogenic intergranular embrittlement in high-Mn austenitic steels and the conditions necessary for its control are examined. It is shown that the high-Mn alloys are inherently susceptible to intergranular embrittlement due to both their low grain boundary cohesion and heterogeneous deformation characteristics. Extrinsic sources of embrittlement which could account for the transition behavior are not observed. An Auger electron spectroscopy (AES) study shows no indication of impurity-segregation-induced embrittlement. No grain boundary precipitation is observed, and austenite stabilization does not ensure ductile fracture. The influence of chemistry modifications on the ductile-to-brittle transition behavior were also examined through additions of N, Cr, and C to binary Fe-31 Mn. Nitrogen additions increase the 77K yield strength at a rate of 2200 MPa per weight percent N, and increase the austenite stability, but also increase the susceptibility of ternary alloys to intergranular fracture. Quaternary Cr additions are effective in increasing the N solubility, and lower the transition temperature. Carbon additions result in complete suppression of intergranular fracture at 77K. Qualitatively significant changes in the deformation heterogeneity with chemistry modifications are not observed. The temper-toughening of Fe-Mn-Cr-N alloys is associated with the grain boundary segregation of boron and the redistribution of N. Both boron and carbon are expected to inhibit intergranular fracture through increases in grain boundary cohesion.

Strum, M.J.

1986-12-01

65

Effect of rate of dose build-up of manganese ions on changes in mechanical properties, morphology, and composition of surface layers of carbon steel  

NASA Astrophysics Data System (ADS)

The effect of a dose build-up rate of 5 × 1016 ion/cm2 under irradiation with manganese ions with an energy of 45 keV and at a current density of 10-50 ?A/cm2 on the mechanical properties, morphology, and composition of the surface layers of carbon steel St3sp has been investigated. It is shown that, among the dose build-up rates used, the optimal rate for surface hardening corresponds to an ion-current density of 10 ?A/cm2. Based on these experimental data, a model of the processes that occur during the implantation of steel with Mn ions has been proposed.

Vorob'ev, V. L.; Bykov, P. V.; Bayankin, V. Ya.

2012-11-01

66

Low-temperature manganese contributions to the elastic constants of face-centred-cubic Fe-Cr-Ni stainless steel  

Microsoft Academic Search

By ultrasonic methods, we determined the elastic constants between 295 and 4 K of nominally Fe-18Cr-8Ni alloys (in wt%) containing up to 6% manganese. We report five elastic constants:C1 = longitudinal modulus,B = bulk modulus,E = Young modulus,G = shear modulus, and v = Poisson ratio. At all temperatures, manganese lowers all these elastic constants. With the exception of v,

H. M. Ledbetter; S. A. Kim

1988-01-01

67

Austenitic stainless steel and drill collar  

SciTech Connect

A non-magnetic austenitic stainless steel, and a drill collar fabricated therefrom solely by hot forging, the steel having a 0.2% yield strength of at least 85 ksi in the hot worked condition, high stress corrosion cracking resistance, good ductility, and low magnetic permeability even if cold worked, and consisting essentially of, in weight percent, from 0.12% to 0.20% carbon, 11% to 14% manganese, about 16% to about 19% chromium, 1.5% to 2.7% nickel, 0.30% to 0.45% nitrogen, 0.5% to 1.0% copper, about 0.75% maximum molybdenum, about 0.80% maximum silicon, about 0.04% maximum phosphorus, about 0.025% maximum sulfur, and balance essentially iron, with the carbon:nitrogen ratio not greater than 0.6:1.

Cordea, J. N.; Jasper, J. C.; Sheth, H. V.

1985-03-05

68

Laboratory demonstration of Redox feed head-end treatment: ruthenium volatilization and manganese dioxide scavenging  

Microsoft Academic Search

The mechanics of manganese dioxide handling, laboratory development of ; manganese dioxide scavenging, and a series of experiments at multicurie level ; combining ruthenium volatilization and manganese dioxide scavenging in stainless ; steel equipment are dealt with.

H. G. Hicks; C. G. McCormack; W. E. Roake

1951-01-01

69

Investigation of the Effect of Tungsten Substitution on Microstructure and Abrasive Wear Performance of In Situ VC-Reinforced High-Manganese Austenitic Steel Matrix Composite  

NASA Astrophysics Data System (ADS)

Particulate VC-reinforced high-manganese austenitic steel matrix composites with different vanadium and tungsten contents were synthesized by conventional alloying and casting route. Microstructural characterizations showed that the composites processed by in situ precipitation of the reinforcements were composed of V8C7 particulates distributed in an austenitic matrix. It was observed that addition of tungsten to austenite increases work-hardening rate of subsurface layer during pin-on disk wear test. The maximum abrasive wear resistance was achieved at tungsten content equal to 2 wt pct. However, excessive addition of tungsten promoted the formation of W3C phase and reduced the abrasive wear resistance because of decrease in distribution homogeneity and volume fraction of the reinforcing VC particles.

Moghaddam, Emad Galin; Karimzadeh, Neda; Varahram, Naser; Davami, Parviz

2013-04-01

70

Manganese recycling in the United States in 1998  

USGS Publications Warehouse

This report describes the flow and processing of manganese within the U.S. economy in 1998 with emphasis on the extent to which manganese is recycled. Manganese was used mostly as an alloying agent in alloys in which it was a minor component. Manganese was recycled mostly within scrap of iron and steel. A small amount was recycled within aluminum used beverage cans. Very little manganese was recycled from materials being recovered specifically for their manganese content. For the United States in 1998, 218,000 metric tons of manganese was estimated to have been recycled from old scrap, of which 96% was from iron and steel scrap. Efficiency of recycling was estimated as 53% and recycling rate as 37%. Metallurgical loss of manganese was estimated to be about 1.7 times that recycled. This loss was mostly into slags from iron and steel production, from which recovery of manganese has yet to be shown economically feasible.

Jones, Thomas S.

2001-01-01

71

Characterization and Prediction of Flow Behavior in High-Manganese Twinning Induced Plasticity Steels: Part II. Jerky Flow and Instantaneous Strain Rate  

NASA Astrophysics Data System (ADS)

The jerky and smooth flow curves in high-manganese twinning induced plasticity (TWIP) steels were investigated by comparing Fe-Mn-C and Fe-Mn-Al-C systems. The pronounced serrations on the flow curves of Fe-Mn-C TWIP steel, produced during tensile testing at 300 K (27 °C) and 373 K (100 °C), were shown to be the result of localized high-temperature Portevin Le-Chatelier (PLC) bands moving across the gage length throughout the deformation. The speed of the PLC bands and their temperature effects were found to be strongly dependent on the applied strain rate, which was controlled by adjusting the cross-head speed of the tensile testing machine. The localized temperature-dependent stacking fault energy (SFE) variations resulting from the PLC effect and adiabatic heating were analyzed and compared for both slow and fast deformation rates. The instabilities in the measured logarithmic strain values caused by jerky flow could cause the local strain rate to deviate systematically from the targeted (applied) strain rate. These instabilities are better observed by calculating the instantaneous strain rate (ISR) values for each instant of deformation along the entire gage length. Finally, a new type of diagram was developed by plotting the true stress against the ISR values. From the diagram, the onset of different mechanisms, such as deformation twinning, nonpronounced, and pronounced serrations, could be marked precisely.

Saeed-Akbari, A.; Mishra, A. K.; Mayer, J.; Bleck, W.

2012-05-01

72

Mapping Phase Transformations in the Heat-Affected-Zone of Carbon Manganese Steel Welds using Spatially Resolved X-Ray Diffraction  

SciTech Connect

Spatially Resolved X-Ray Diffraction (SRXRD) was used to investigate phase transformations that occur in the heat affected zone (HAZ) of gas tungsten arc (GTA) welds in AISI 1005 carbon-manganese steel. In situ SRXRD experiments performed at the Stanford Synchrotron Radiation Laboratory (SSRL) probed the phases present in the HAZ during welding, and these real-time observations of the HAZ phases were used to construct a map of the phase transformations occurring in the HAZ. This map identified 5 principal phase regions between the liquid weld pool and the unaffected base metal. Regions of annealing, recrystallization, partial transformation and complete transformation to {alpha}-Fe, {gamma}-Fe, and {delta}-Fe phases were identified using SRXRD, and the experimental results were combined with a heat flow model of the weld and thermodynamic calculations to compare these results with the important phase transformation isotherms. From the resulting phase transformation map, the kinetics of phase transformations that occur under the highly non-isothermal heating and cooling cycles produced during welding of steels can be better understood and modeled.

Elmer, J W; Wong, J; Ressler, T; Palmer, T A

2002-02-12

73

Serration Phenomena Occurring During Tensile Tests of Three High-Manganese Twinning-Induced Plasticity (TWIP) Steels  

NASA Astrophysics Data System (ADS)

In this study, the serration phenomena of two high-Mn TWIP steels and an Al-added TWIP steel were examined by tensile tests, and were explained by the microstructural evolution including formation of localized Portevin-Le Chatelier deformation bands and twins. In stress-strain curves of the high-Mn steels, serrations started in a fine and short shape, and their height and periodic interval increased with increasing strain, whereas the Al-added steel did not show any serrations. According to digital images of strain rate and strain obtained from a vision strain gage system, deformation bands were initially formed at the upper region of the gage section, and moved downward along the tensile loading direction. The time when the band formation started was matched with the time when one serration occurred in the stress-time curve. This serration behavior was generally explained by dynamic strain aging, which was closely related with the formation of deformation bands.

Hong, Seokmin; Shin, Sang Yong; Lee, Junghoon; Ahn, Dong-Hyun; Kim, Hyoung Seop; Kim, Sung-Kyu; Chin, Kwang-Geun; Lee, Sunghak

2013-09-01

74

Influence of alloy composition on the cryogenic mechanical properties of AISI 200 grade high-manganese austenitic steels  

SciTech Connect

Research on the effect of composition on the cryogenic mechanical properties of high-Mn austenitic steels showed that both the yield strength and change of strength with alloy processing increased significantly with increasing interstitial content. Alloy toughness deteriorated if carbon content was raised to 0.1% or higher or if delta-ferrite was retained in the as-cooled alloy. On the basis of these investigations an alloy of nominal composition 18Mn-5Ni-16Cr-0.024C-0.22 N was made and tested at 4K. Both its strength-toughness characteristic and fatigue crack growth properties compared favorably to those of 304LN and 304N cryogenic steels.

Ogawa, R.; Morris, J.W. Jr.

1982-05-01

75

Influence of alloy composition on the cryogenic mechanical properties of AISI 200 grade high-manganese austenitic steels  

Microsoft Academic Search

Research on the effect of composition on the cryogenic mechanical properties of high-Mn austenitic steels showed that both the yield strength and change of strength with alloy processing increased significantly with increasing interstitial content. Alloy toughness deteriorated if carbon content was raised to 0.1% or higher or if delta-ferrite was retained in the as-cooled alloy. On the basis of these

R. Ogawa; J. W. Jr. Morris

1982-01-01

76

Toughness evaluation of a shielded metal arc carbon-manganese steel welded joint subjected to multiple post weld heat treatment  

Microsoft Academic Search

This study was part of a program to investigate the influence of multiple post weld heat treatment (PWHT) on the fracture\\u000a toughness and defect tolerance of a welded joint. The present work reports base metal data obtained for a quenched and tempered\\u000a BS7191 Grade 450EM steel (0.10wt%C–1.08wt%Mn), weld metal data for a ferritic multipass weld obtained by shielded metal arc

I. de S. Bott; J. C. G. Teixeira

1999-01-01

77

Use of pre-oxidation to improve reactive wetting of high manganese alloyed steel during hot-dip galvanizing  

Microsoft Academic Search

The present study discusses hot-dip galvanizing of a Fe–23% Mn–0.6% C–0.3% Si steel using a Zn–0.22%Al bath. The paper concentrates on reactive Zn wetting on top a covering external oxide layer occurring after in-line annealing. Annealing was performed by soaking at 800°C\\/60s in 5% H2–N2 at different dewpoints. In-line pre-oxidation at 600°C\\/10s in 1.8% O2–N2 was further performed and the

Marc Blumenau; Martin Norden; Frank Friedel; Klaus Peters

2011-01-01

78

Multiobjective Optimization of Manganese Recovery from Sea Nodules Using Genetic Algorithms  

Microsoft Academic Search

Treatment of low grade manganese ores is receiving widespread attention due to major use of manganese (85–90%) as ferromanganese alloy in the rapidly growing iron and steel sector and also in other important industrial products like electrolytic manganese dioxide (EMD) used in the energy sector. Manganese bearing polymetallic sea nodules containing less than 40% Mn fall in the category of

Arijit Biswas; N. Chakraborti; P. K. Sen

2008-01-01

79

Liver Manganese in Hemochromatosis.  

National Technical Information Service (NTIS)

A comparative study was performed in which the manganese concentration in liver samples from cases of hemochromatosis was compared with the manganese concentration of normal liver. A higher mean concentration of liver manganese was found in the former gro...

L. B. Altstatt S. Pollack M. H. Feldman R. C. Reba W. H. Crosby

1966-01-01

80

Effect of the carbide phase on the tribological properties of high-manganese antiferromagnetic austenitic steels alloyed with vanadium and molybdenum  

NASA Astrophysics Data System (ADS)

Effect of special carbides (VC, M 6C, Mo2C) on the wear resistance and friction coefficient of austenitic stable ( M s below -196°C) antiferromagnetic ( T N = 40-60°C) steels 80G20F2, 80G20M2, and 80G20F2M2 has been studied. The structure and the effective strength (microhardness H surf, shear resistance ?) of the surface layer of these steels have been studied using optical and electron microscopy. It has been shown that the presence of coarse particles of primary special carbides in the steels 80G20F2, 80G20M2, and 80G20F2M2 quenched from 1150°C decreases the effective strength and the resistance to adhesive and abrasive wear of these materials. This is caused by the negative effect of carbide particles on the toughness of steels and by a decrease in the carbon content in austenite due to a partial binding of carbon into the above-mentioned carbides. The aging of quenched steels under conditions providing the maximum hardness (650°C for 10 h) exerts a substantial positive effect on the parameters of the effective strength ( H surf, ?) of the surface layer and, correspondingly, on the resistance of steels to various types of wear (abrasive, adhesive, and caused by the boundary friction). The maximum positive effect of aging on the wear resistance is observed upon adhesive wear of the steels under consideration. Upon friction with enhanced sliding velocities (to 4 m/s) under conditions of intense (to 500-600°C) friction-induced heating, the 80G20F2, 80G20M2, and, especially, 80G20F2M2 steels subjected to quenching and aging substantially exceed the 110G13 (Hadfield) steel in their tribological properties. This is due to the presence in these steels of a favorable combination of high effective strength and friction heat resistance of the surface layer, which result from the presence of a large amount of special carbides in these steels and from a high degree of alloying of the matrix of these steels by vanadium and molybdenum. In the process of friction, there are formed nanocrystalline austenitic structures possessing high effective strength and wear resistance on the wear surface of these steels.

Korshunov, L. G.; Kositsina, I. I.; Sagaradze, V. V.; Chernenko, N. L.

2011-07-01

81

Nurse Outcomes in Magnet® and Non-Magnet Hospitals  

PubMed Central

The important goals of Magnet® hospitals are to create supportive professional nursing care environments. A recently published paper found little difference in work environments between Magnet and non-Magnet hospitals. The aim of this study was to determine whether work environments, staffing, and nurse outcomes differ between Magnet and non-Magnet hospitals. A secondary analysis of data from a 4-state survey of 26,276 nurses in 567 acute care hospitals to evaluate differences in work environments and nurse outcomes in Magnet and non-Magnet hospitals was conducted. Magnet hospitals had significantly better work environments (t = ?5.29, P < .001) and more highly educated nurses (t = ?2.27, P < .001). Magnet hospital nurses were 18% less likely to be dissatisfied with their job (P < .05) and 13% less likely to report high burnout (P < .05). Magnet hospitals have significantly better work environments than non-Magnet hospitals. The better work environments of Magnet hospitals are associated with lower levels of nurse job dissatisfaction and burnout.

Kelly, Lesly A.; McHugh, Matthew D.; Aiken, Linda H.

2011-01-01

82

Influence of additional elements (Mo, Nb, Ta and B) on the mechanical properties of high-manganese dual-phase steels  

Microsoft Academic Search

The influence of a small amount of alloying elements such as molybdenum, niobium, tantalum and boron to the 3 wt% Mn ferritic dual-phase steels was examined. These elements give a microstructure in which the fine martensite phase is well dispersed in the ferrite matrix, which 4leads to a remarkable reinforcement effect on mechanical properties. It is possible to obtain a

N. Terao; B. Cauwe

1988-01-01

83

Electron spin polarization in a non-magnetic heterostructure  

NASA Astrophysics Data System (ADS)

The spin dependent electron transmission through a non-magnetic III V semiconductor symmetric well is studied theoretically so as to investigate the output transmission current polarization at zero magnetic field. Transparency of electron transmission is calculated as a function of electron energy as well as the well width, within the one electron band approximation along with the spin orbit interaction. Enhanced spin-polarized resonant tunneling in the heterostructure due to Dresselhaus and Rashba spin orbit coupling induced splitting of the resonant level is observed. We predict that a spin-polarized current spontaneously emerges in this heterostructure. This effect could be employed in the fabrication of spin filters, spin injectors and detectors based on non-magnetic semiconductors.

Peter, A. John

2008-07-01

84

Non-magnetic materials with negative refractive index  

NASA Astrophysics Data System (ADS)

We develop a new approach to materials with negative refraction index which can be implemented for optical and infrared frequencies. In contrast to conventional designs which require simultaneously negative dielectric permittivity and magnetic permeability, our system is intrinsically non-magnetic and makes use of an anisotropic dielectric constant to provide negative refractive index in waveguide geometry. The proposed approach is not limited to the proximity of a resonance and thus allows for low loss, critical for super-lensing applications.

Narimanov, Evgenii E.; Alekseyev, Leonid V.; Podolskiy, Viktor A.

2005-08-01

85

Volatilization from PCA steel alloy  

SciTech Connect

The mobilizations of key components from Primary Candidate Alloy (PCA) steel alloy have been measured with laboratory-scale experiments. The experiments indicate most of the mobilization from PCA steel is due to oxide formation and spalling but that the spalled particles are large enough to settle rapidly. Based on the experiments, models for the volatization of iron, manganese, and cobalt from PCA steel in steam and molybdenum from PCA steel in air have been derived.

Hagrman, D.L.; Smolik, G.R.; McCarthy, K.A.; Petti, D.A.

1996-08-01

86

Improved Manganese Phosphate Coatings.  

National Technical Information Service (NTIS)

Work was conducted to determine the mechanism by which superior manganese phosphate coatings are produced. The phosphate coatings were applied at temperatures above 212 F and with manganese-organic compounds added to the phosphating solution. Experimental...

H. Crain

1975-01-01

87

Use of Manganese Cast Iron for Parts of Soil Working Machines (Primenenie Margantsovistogo Chuguna dlya Detalei Pochvoobrabatyvayushchikh Mashin).  

National Technical Information Service (NTIS)

Cast steels with high manganese contents (4-12%) and inoculated with cerium were evaluated as materials for tillage tools. The greatest wear resistance to soil abrasion occurred for the 4% manganese steels. Landsides of plows, cultivator tips, and disk hi...

V. B. Lyadski M. I. Masumov V. I. Rublev

1971-01-01

88

Astrocytes and manganese neurotoxicity  

Microsoft Academic Search

Increasing evidence suggests that astrocytes are the site of early dysfunction and damage in manganese neurotoxicity. Astrocytes accumulate manganese by a high affinity, high capacity, specific transport system. Chronic exposure to manganese leads to increased pallidal signal hyperintensities on T1-weighted magnetic resonance images and selective neuronal loss in basal ganglia structures together with characteristic astrocytic changes known as Alzheimer type

Alan S Hazell

2002-01-01

89

Influence of annealing conditions on the galvanizability and galvannealing properties of TiNb interstitial-free steels, strengthened with phosphorous and manganese  

Microsoft Academic Search

A high-strength interstitial-free (HS IF) steel, solution strengthened with P and Mn, was hot-dip galvanized and galvannealed\\u000a in a laboratory hot-dip simulator. The dew point of the N2-H2 annealing atmosphere during recrystallization was varied, and the effect of the dew-point changes on the galvannealing kinetics\\u000a was studied. Annealing in a high-dew-point N2-H2 atmosphere improved the wettability by the zinc and

I. Hertveldt; B. C. De Cooman; S. Claessens

2000-01-01

90

Health Hazard Evaluation Determination Report No. HHE-78-074-575, Interlake Steel, Inc., Wilder, Kentucky.  

National Technical Information Service (NTIS)

Environmental and personal air samples were analyzed for manganese (7439965), calcium-oxide (1305788), iron-oxide, and total particulates at Interlake Steel, Inc., (SIC-332) Wilder, Kentucky, on August 30 and 31, 1978. Manganese air concentrations were be...

1979-01-01

91

Small angle neutron scattering modeling of copper-rich precipitates in steel  

SciTech Connect

The magnetic to nuclear scattering intensity ratio observed in the scattering from copper rich precipitates in irradiated pressure vessel steels is much smaller than the value of 11.4 expected for a pure copper precipitate in iron. A model for precipitates in pressure vessel steels which matches the observed scattering typically incorporates manganese, nickel, silicon and other elements and it is assumed that the precipitate is non-magnetic. In the present work consideration is given to the effect of composition gradients and ferromagnetic penetration into the precipitate on the small angle scattering cross section for copper rich clusters as distinguished from conventional precipitates. The calculation is an extension of a scattering model for micelles which consist of shells of varying scattering density. A discrepancy between recent SANS scattering experiments on pressure vessel steels was found to be related to applied magnetic field strength. The assumption of cluster structure and its relation to atom probe FIM findings as well as the effects of insufficient field for magnetic saturation is discussed.

Spooner, S.

1997-11-01

92

Magnetic effects at the interface between non-magnetic oxides.  

PubMed

The electronic reconstruction at the interface between two insulating oxides can give rise to a highly conductive interface. Here we show how, in analogy to this remarkable interface-induced conductivity, magnetism can be induced at the interface between the otherwise non-magnetic insulating perovskites SrTiO3 and LaAlO3. A large negative magnetoresistance of the interface is found, together with a logarithmic temperature dependence of the sheet resistance. At low temperatures, the sheet resistance reveals magnetic hysteresis. Magnetic ordering is a key issue in solid-state science and its underlying mechanisms are still the subject of intense research. In particular, the interplay between localized magnetic moments and the spin of itinerant conduction electrons in a solid gives rise to intriguing many-body effects such as Ruderman-Kittel-Kasuya-Yosida interactions, the Kondo effect and carrier-induced ferromagnetism in diluted magnetic semiconductors. The conducting oxide interface now provides a versatile system to induce and manipulate magnetic moments in otherwise non-magnetic materials. PMID:17546035

Brinkman, A; Huijben, M; van Zalk, M; Huijben, J; Zeitler, U; Maan, J C; van der Wiel, W G; Rijnders, G; Blank, D H A; Hilgenkamp, H

2007-06-03

93

Manganese action in brain function  

Microsoft Academic Search

Manganese, an essential trace metal, is supplied to the brain via both the blood–brain and the blood–cerebrospinal fluid barriers. There are some mechanisms in this process and transferrin may be involved in manganese transport into the brain. A large portion of manganese is bound to manganese metalloproteins, especially glutamine synthetase in astrocytes. A portion of manganese probably exists in the

Atsushi Takeda

2003-01-01

94

FACTORS AFFECTING SILICOMANGANESE PRODUCTION USING MANGANESE RICH SLAG IN THE CHARGE  

Microsoft Academic Search

Silicomanganese is widely used as a complex reducer and an alloying addition in the production of various grades of steel due to its economic and metallurgical advantages. It is also used as a semi-product in the manufacture of medium- and low-carbon ferromanganese and metallic manganese. Manganese-rich slag, resulting from high carbon ferromanganese production, has the advantages of high manganese content,

M. Eissa; A. Fath; A. Ahmed; A. El-Mohammad; K. El-Fawakhry

95

Process for producing manganese dioxide  

SciTech Connect

The invention relates to the manufacture of manganese dioxide by a chemical process. The resulting manganese dioxide product takes the form of particles characterized by filament-like protrusions jutting out from its surface. The manganese dioxide particles having such surface features can be manufactured by reacting manganese sulfate with sodium peroxodisulfate in an aqueous solution. The process can be controlled to yield high density manganese dioxide. The manganese dioxide formed in the process can be deposited directly onto the surface of electrolytic manganese dioxide (EMD). The manganese dioxide product the is particularly suitable for use as a cathode active material in electrochemical cells. 16 figs.

Wang, E.I.; Lin, L.; Bowden, W.L.

1994-01-11

96

Process for producing manganese dioxide  

Microsoft Academic Search

The invention relates to the manufacture of manganese dioxide by a chemical process. The resulting manganese dioxide product takes the form of particles characterized by filament-like protrusions jutting out from its surface. The manganese dioxide particles having such surface features can be manufactured by reacting manganese sulfate with sodium peroxodisulfate in an aqueous solution. The process can be controlled to

E. I. Wang; L. Lin; W. L. Bowden

1994-01-01

97

Magnetic-field effects in non-magnetic glasses  

NASA Astrophysics Data System (ADS)

Recently, it was found that the multi-component glass a-BaO-Al2O3-SiO2 exhibits unusual magnetic properties at very low temperatures. Thus the question arises whether this is a specialty of that particular glass or a more general phenomenon. We report here on our studies of the magnetic-field dependence of the dielectric properties of the borosilicate glass BK7 which contains only a negligible amount of magnetic impurities. Since this glass also responds sensitively to magnetic fields, our investigations demonstrate that the reaction of glasses to magnetic fields is not caused by magnetic impurities but reflects a more general phenomenon. In addition, we have observed that the variation of the dielectric constant and the loss angle with magnetic field depend on the amplitude of the electric field that is used to measure the glass capacitance. We present the data and discuss possible origins of the magnetic-field phenomena in non-magnetic glasses.

Wohlfahrt, M.; Strehlow, P.; Enss, C.; Hunklinger, S.

2001-12-01

98

Large magnetoresistance in non-magnetic silver chalcogenides.  

SciTech Connect

Several materials have been identified over the past few years as promising candidates for the development of new generations of magnetoresistive devices. These range from artificially engineered magnetic multilayers1 and granular alloys2,3, in which the magnetic-field response of interfacial spins modulates electron transport to give rise to 'giant' magnetoresistance4, to the manganite perovskites5, 6, 7, in which metal-insulator transitions driven by a magnetic field give rise to a 'colossal' magnetoresistive response (albeit at very high fields). Here we describe a hitherto unexplored class of magnetoresistive compounds, the silver chalcogenides. At high temperatures, the compounds Ag2S, Ag2Se and Ag2Te are superionic conductors; below approx400 K, ion migration is effectively frozen and the compounds are non-magnetic semiconductors8,9 that exhibit no appreciable magnetoresistance10. We show that slightly altering the stoichiometry can lead to a marked increase in the magnetic response. At room temperature and in a magnetic field of approx55 kOe, Ag2+deltaSe and Ag2+deltaTe show resistance increases of up to 200%, which are comparable with the colossal-magnetoresistance materials. Moreover, the resistance of our most responsive samples exhibits an unusual linear dependence on magnetic field, indicating both a potentially useful response down to fields of practical importance and a peculiarly long length scale associated with the underlying mechanism.

Xu, R.; Husmann, A.; Rosenbaum, T. F.; Saboungi, M.-L.; Enderby, J. E.; Littlewood, P. B.; Materials Science Division; Univ. of Chicago; Bell Lab.

1997-11-01

99

The effect of manganese additions on the reactive evaporation of chromium in Ni–Cr alloys  

SciTech Connect

Chromium is used as an alloy addition in stainless steels and nickel-chromium alloys to form protective chromium oxide scales. Chromium oxide undergoes reactive evaporation in high temperature exposures in the presence of oxygen and/or water vapor. The deposition of gaseous chromium species onto solid oxide fuel cell electrodes can reduce the efficiency of the fuel cell. Manganese additions to the alloy can reduce the activity of chromium in the oxide, either from solid solution replacement of chromium with manganese (at low levels of manganese) or from the formation of manganese-chromium spinels (at high levels of manganese). This reduction in chromium activity leads to a predicted reduction in chromium evaporation by as much as a factor of 35 at 800 °C and 55 at 700 °C. Quantifying the effects of manganese additions on chromium evaporation should aid alloy development of metallic interconnects and balance-of-plant alloys.

Holcomb, G.R.; Alman, D.E.

2006-05-01

100

Assessment of the manganese content of the drinking water source in Yancheng, China.  

PubMed

Excessive intake of manganese can damage the nervous system of the human body. In August 2009, the manganese content of the drinking water source in Yancheng exceeded the national standard of drinking water source, which influenced the daily life of the local residents. The aim of this study was to investigate the factors leading to the manganese content of river water in Yancheng exceeding the national standard. To the data, the manganese content of surface water in Yancheng already met the national standard of drinking water source in September 2009, but the manganese content of river sediment was relatively high, especially in Mangshe River and Tongyu River. It was worthwhile to note that the soluble manganese content of the sediment in Mangshe River was even as high as 270 mg kg(-1), which suggested that the release of manganese from the sediment was the major cause of the pollution. The manganese content of the soil near the rivers was also determined, and the results indicated that the wastewater and waste slag discharged by the stainless steel factories nearby were the main pollution sources of manganese. Furthermore, the environmental factors affecting the release of manganese from the sediment were also investigated. PMID:20599319

Wang, Jinnan; Li, Aimin; Wang, Qiongjie; Zhou, Yang; Fu, Lichun; Li, Yan

2010-06-11

101

High strength, tough alloy steel  

DOEpatents

A high strength, tough alloy steel is formed by heating the steel to a temperature in the austenite range (1000.degree.-1100.degree. C.) to form a homogeneous austenite phase and then cooling the steel to form a microstructure of uniformly dispersed dislocated martensite separated by continuous thin boundary films of stabilized retained austenite. The steel includes 0.2-0.35 weight % carbon, at least 1% and preferably 3-4.5% chromium, and at least one other substitutional alloying element, preferably manganese or nickel. The austenite film is stable to subsequent heat treatment as by tempering (below 300.degree. C.) and reforms to a stable film after austenite grain refinement.

Thomas, Gareth (Berkeley, CA); Rao, Bangaru V. N. (Albany, CA)

1979-01-01

102

21 CFR 184.1449 - Manganese citrate.  

Code of Federal Regulations, 2010 CFR

... § 184.1449 Manganese citrate. (a) Manganese citrate (Mn3 (C6 H5 O7 )2 ...white powder. It is obtained by precipitating manganese carbonate from manganese sulfate and sodium carbonate solutions. The...

2009-04-01

103

21 CFR 184.1449 - Manganese citrate.  

Code of Federal Regulations, 2013 CFR

... § 184.1449 Manganese citrate. (a) Manganese citrate (Mn3 (C6 H5 O7 )2, ...white powder. It is obtained by precipitating manganese carbonate from manganese sulfate and sodium carbonate solutions. The...

2013-04-01

104

21 CFR 184.1449 - Manganese citrate.  

Code of Federal Regulations, 2010 CFR

... § 184.1449 Manganese citrate. (a) Manganese citrate (Mn3 (C6 H5 O7 )2 ...white powder. It is obtained by precipitating manganese carbonate from manganese sulfate and sodium carbonate solutions. The...

2010-01-01

105

Astrocytes and manganese neurotoxicity.  

PubMed

Increasing evidence suggests that astrocytes are the site of early dysfunction and damage in manganese neurotoxicity. Astrocytes accumulate manganese by a high affinity, high capacity, specific transport system. Chronic exposure to manganese leads to increased pallidal signal hyperintensities on T1-weighted magnetic resonance images and selective neuronal loss in basal ganglia structures together with characteristic astrocytic changes known as Alzheimer type II astrocytosis. Manganese is sequestered in mitochondria where it inhibits oxidative phosphorylation. Exposure of astrocytes to manganese results in important changes including (i) decreased uptake of glutamate; (ii) increased densities of binding sites for the "peripheral-type" benzodiazepine receptor (PTBR), a class of receptor localized to mitochondria of astrocytes and involved in oxidative metabolism, mitochondrial proliferation, and neurosteroid synthesis; (iii) increased gene expression and activity of the glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDH), known to be associated with apoptosis; (iv) increased uptake of L-arginine, a precursor of nitric oxide, together with increased expression of the inducible form of nitric oxide synthase (iNOS). Potential consequences of these alterations in astrocytic gene expression include failure of energy metabolism, production of reactive oxygen species (ROS), increased extracellular glutamate concentration and excitotoxicity which could play a key role in manganese-induced neuronal cell death as a direct result of impaired astrocytic-neuronal interactions. PMID:12106778

Hazell, Alan S

2002-10-01

106

Reduced-activation austenitic stainless steels: The Fe--Mn--Cr--C system  

Microsoft Academic Search

Nickel-free manganese-stabilized steels are being developed for fusion-reactor applications. As the first part of this effort, the austenite-stable region in the Fe--Mn--Cr--C system was determined. Results indicated that the Schaeffler diagram developed for Fe--Ni--Cr--C alloys cannot be used to predict the constituents expected for high-manganese steels. This is true because manganese is not as strong an austenite stabilizer relative to

R. L. Klueh; P. J. Maziasz

1988-01-01

107

Comparative leaching of spent zinc-manganese-carbon batteries using sulfur dioxide in ammoniacal and sulfuric acid solutions  

Microsoft Academic Search

The non-magnetic fraction of spent zinc-manganese-carbon batteries containing 20.8% Zn, 22.7% Mn, 2.65% Fe, and <0.1% Hg, Ni, Co, Cu and Pb was leached in H2SO4, H2SO4\\/SO2, NH3 and NH3\\/SO2 at 30-60°C. In acid media the complete dissolution of zinc is unaffected by SO2. However, the reductive role of SO2 increases the leaching of manganese in H2SO4 from 25% to

G. Senanayake; S. M. Shin; A. Senaputra; A. Winn; D. Pugaev; J. Avraamides; J. S. Sohn; D. J. Kim

2010-01-01

108

Non-magnetic System with Negative Index of Refraction for Terahertz Application  

Microsoft Academic Search

We propose a non-magnetic system with negative refraction index for terahertz applications. The system is based on a planar metallic waveguide with bismuth core, and uses strong anisotropy of bismuth permittivity and its ultra-low losses

Leo Alekseyev; Viktor A. Podolskiy; Evgenii E. Narimanov

2005-01-01

109

Study of Manganese Phosphating Reactions.  

National Technical Information Service (NTIS)

Work was conducted to determine the composition of and the reactions associated with the formation of manganese-phosphate coatings. An improved phosphate coating was studied as produced from a stock manganese phosphating bath to which an addition of manga...

J. Menke

1971-01-01

110

Superconductivity in the non-magnetic state of iron under pressure  

Microsoft Academic Search

Ferromagnetism and superconductivity are thought to compete in conventional superconductors, although in principle it is possible for any metal to become a superconductor in its non-magnetic state at a sufficiently low temperature. At pressures above 10GPa, iron is known to transform to a non-magnetic structure and the possibility of superconductivity in this state has been predicted. Here we report that

Katsuya Shimizu; Tomohiro Kimura; Shigeyuki Furomoto; Keiki Takeda; Kazuyoshi Kontani; Yoshichika Onuki; Kiichi Amaya

2001-01-01

111

Comparison of magnet school program options and magnet school to non-magnet school program options  

Microsoft Academic Search

The purpose of this causal comparative study was to compare student achievement between two magnet school program types as well as to make a comparison to student achievement in a non-magnet school program. Two elementary magnet school programs in one elementary school and one non-magnet elementary school were selected for this study within the same school corporation. Thirty-five students from

Nikki C Woodson

2004-01-01

112

Non-magnetic nano-composites for optical and infrared negative refraction index media  

Microsoft Academic Search

We develop an approach to use nanostructured plasmonic materials as a non-magnetic negative-refractive index system at optical and near-infrared frequencies. In contrast to conventional negative refraction materials, our design does not require periodicity and thus is highly tolerant to fabrication defects. Moreover, since the proposed materials are intrinsically non-magnetic, their performance is not limited to proximity of a resonance so

Robyn Wangberg; Justin Elser; Evgenii E. Narimanov; Viktor A. Podolskiy

113

Free-Cutting Stainless Steel.  

National Technical Information Service (NTIS)

The object of the invention is a free-cutting stainless steel containing 0.35 - 0.45% carbon, 16 - 18% chromium, 1.5 - 2.5% nickel, 0.7 - 1.2% manganese and up to 0.5% silicon is distinguished by the fact that, in order to enhance the mechanical and antic...

N. M. Pisarev V. M. Kozhin

1965-01-01

114

Experimental Analysis and Modelling of Fe-Mn-Al-C Duplex Steel Mechanical Behaviour  

Microsoft Academic Search

A new variety of duplex steels with high content of manganese and aluminum has been elaborated in Arcelor Research. These steels contain two phases: austenite and ferrite combining the best features of austenitic and ferritic steels. In this work, four duplex steels with different chemical composition and phase volume fraction are studied. The evolution of internal stresses for the two

M. N. Shiekhelsouk; V. Favier; K. Inal; O. Bouaziz; M. Cherkaoui

2007-01-01

115

Manganese biomining: A review.  

PubMed

Biomining comprises of processing and extraction of metal from their ores and concentrates using microbial techniques. Currently this is used by the mining industry to extract copper, uranium and gold from low grade ores but not for low grade manganese ore in industrial scale. The study of microbial genomes, metabolites and regulatory pathways provide novel insights to the metabolism of bioleaching microorganisms and their synergistic action during bioleaching operations. This will promote understanding of the universal regulatory responses that the biomining microbial community uses to adapt to their changing environment leading to high metal recovery. Possibility exists of findings ways to imitate the entire process during industrial manganese biomining endeavor. This paper reviews the current status of manganese biomining research operations around the world, identifies factors that drive the selection of biomining as a processing technology, describes challenges in exploiting these innovations, and concludes with a discussion of Mn biomining's future. PMID:21632238

Das, A P; Sukla, L B; Pradhan, N; Nayak, S

2011-05-14

116

Effect of nitrogen on the plasma (ion)-carburized layer of high nitrogen austenitic stainless steel  

Microsoft Academic Search

Austenitic stainless steel or high nitrogen austenitic steel are used extensively as structural non-magnetic materials. The former, because of their low surface hardness, have low wear resistance. Recently developed plasma (ion)-carburizing improves the surface of austenitic stainless steel by removing the oxide scale. In contrast, high nitrogen austenitic stainless steel are expected as wear-resistance material because the hardness is higher

Y. Ueda; N. Kanayama; K. Ichii; T. Oishi; H. Miyake

2005-01-01

117

Tissue Manganese Concentrations in Young Male Rhesus Monkeys following Subchronic Manganese Sulfate Inhalation  

Microsoft Academic Search

High-dose human exposure to manganese results in manganese accumulation in the basal ganglia and dopaminergic neuropa- thology. Occupational manganese neurotoxicity is most frequently linked with manganese oxide inhalation; however, exposure to other forms of manganese may lead to higher body burdens. The objective of this study was to determine tissue manganese con- centrations in rhesus monkeys following subchronic (6 h\\/day,

David C. Dorman; Melanie F. Struve; Marianne W. Marshall; Carl U. Parkinson; R. Arden James; Brian A. Wong

2006-01-01

118

CONVERSATION OF DISSOLVED MANGANESE TO PARTICULATE MANGANESE DURING DIATOM BLOOM: EFFECTS ON THE MANGANESE CYCLE IN THE MERL MICROCOSMS  

EPA Science Inventory

Conversion of dissolved manganese to particulate manganese occurred during a minor diatom bloom during August and September 1978 in the MERL microcosms. Correlations between chlorophyll a and particulate manganese suggest that 29 moles Mn were transferred to the particulate phase...

119

Optimized cylindrical invisibility cloak with minimum layers of non-magnetic isotropic materials  

NASA Astrophysics Data System (ADS)

We present optimized design of cylindrical invisibility cloak with minimum layers of non-magnetic isotropic materials. Through an optimization procedure based on genetic algorithm, simpler cloak structure and more realizable material parameters can be achieved with better cloak performance than that of an ideal non-magnetic cloak with a reduced set of parameters. We demonstrate that a cloak shell with only five layers of two normal materials can result in an average 20 dB reduction in the scattering width for all directions when covering the inner conducting cylinder with the cloak. The optimized design can substantially simplify the realization of the invisibility cloak, especially in the optical range.

Yu, Zhenzhong; Feng, Yijun; Xu, Xiaofei; Zhao, Junming; Jiang, Tian

2011-05-01

120

21 CFR 582.5455 - Manganese glycerophosphate.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Manganese glycerophosphate. 582.5455 Section...or Dietary Supplements 1 § 582.5455 Manganese glycerophosphate. (a) Product. Manganese glycerophosphate. (b) Conditions...

2013-04-01

121

Hyperfine fields amd electronic structure of non-magnetic impurities in iron  

Microsoft Academic Search

Hyperfine fields of non-magnetic impurities in iron are calculated using the local-density formalism in an embedded cluster model. The hyperfine fields are seen to result from a delicate balance between negative exchange polarized “bound-paired” states and positive “unpaired-band” contributions. Pressure and temperature dependence and effects due to lattice relaxation are discussed.

B. Lindgren

1983-01-01

122

Temperature Profile Along an Induction Heated, Moving Non-Magnetic Charge.  

National Technical Information Service (NTIS)

Induction heating system, comprising three sections of a heating coil connected in series and supplied from one source, will be discussed. The charge to be heated is a non-magnetic pipe moving with steady speed. The heating coil is water cooled. Digital m...

K. Januszkiewicz

1984-01-01

123

The effect of doping a molecular spin ladder with non-magnetic impurities.  

PubMed

Since carrier doping of two-leg spin ladders can theoretically induce a superconductive state, investigation of such systems is of great use in the study of superconductivity. In this paper, we report the successful creation of a non-magnetic impurity doped into a two-leg molecular spin ladder and the characterization of its magnetic properties. PMID:24030585

Nishihara, Sadafumi; Zhang, Xiao; Kunishio, Kazuhisa; Inoue, Katsuya; Ren, Xiao-Ming; Akutagawa, Tomoyuki; Kishine, Jun-Ichiro; Fujisawa, Masashi; Asakura, Atsushi; Okubo, Susumu; Ohta, Hitoshi; Nakamura, Takayoshi

2013-10-15

124

Heights of Formation of Non-Magnetic Solar Lines Suitable for Velocity Studies.  

National Technical Information Service (NTIS)

Heights of formation of lines that do not exhibit Zeeman splitting are calculated using an LTE, partial non-LTE, and full non-LTE approach. Non-magnetic (g=0) lines are valuable for velocity investigations in quiet-Sun magnetic field regions, and a knowle...

R. C. Altrock L. J. November G. W. Simon R. W. Milkey S. P. Worden

1974-01-01

125

Optical properties of magnetic and non-magnetic composites of ferrofluids  

Microsoft Academic Search

Composites consisting of magnetic and non-magnetic micronsize particles suspended in a ferrofluid (FF) constitute magnetorheological (MR) fluid. Structuring occurs in an applied magnetic field and can results in the solidification of the composites. A novel magneto-optical effect of extremum and inversion in sign with increasing applied magnetic field strength in this composite is observed. The field strengths at which the

Rajesh Patel; R. V. Upadhyay; R. V. Mehta

2006-01-01

126

Oxidative basis of manganese neurotoxicity.  

PubMed

Exposure to excessive levels of manganese, an essential trace element, can evoke severe psychiatric and extrapyramidal motor dysfunction closely resembling Parkinson's disease. The clinical manifestations of manganese toxicity arise from focal injury to the basal ganglia. This region, characterized by intense consumption of oxygen and significant dopamine content, can incur mitochondrial dysfunction, depletion of levels of peroxidase and catalase, and catecholamine biochemical imbalances following manganese exposure. The site specificity of the pathology and the nature of the cellular damage caused by manganese have been attributed to its capacity to produce cytotoxic levels of free radicals. However, support for such a pro-oxidant role for manganese has been largely limited to inferences drawn from histopathological observations. More recently, research efforts into the molecular details of manganese toxicity have provided evidence of an etiological relationship between oxidative stress and manganese-related neurodegeneration. This review focuses on studies that evaluate the redox chemistry of manganese during the neurodegenerative process and its molecular consequences. PMID:15105260

HaMai, Diem; Bondy, Stephen C

2004-03-01

127

Advancements in Steel for Weight Reduction of P900 Armor Plate.  

National Technical Information Service (NTIS)

Ballistic tests were conducted on a high manganese and high aluminum austenitic steel that is age hardenable. These lightweight steels (12 to 18% lower in density) were investigated as alternatives to MIL-PRF- 32269 steel alloys for application in P900 pe...

D. C. Van Aken J. S. Montgomery R. A. Howell

2008-01-01

128

Method for dehydrating manganese dioxide  

SciTech Connect

A method is described for preparing a water-free lithium-manganese dioxide battery comprising: assembling the battery comprising lithium anode, a cathode comprising carbon and manganese dioxide, and a cell container; adding to the cell container a fluid containing a dehydrating agent which reacts with water bound to the manganese dioxide to form a reaction product that is extractable from the manganese dioxide; removing the fluid from the cell container; hermetically sealing and connecting the container to a vacuum source; establishing a vacuum within the compartment to pull off any remaining amount of the fluid and any volatile reaction product from the manganese dioxide; releasing the vacuum; and adding anhydrous electrolyte and hermetically sealing the cell.

Marincic, N.; Fuksa, R.

1987-05-05

129

The Mutagenicity and Carcinogenicity of Inorganic Manganese Compounds: A Synthesis of The Evidence  

Microsoft Academic Search

Manganese (Mn), a naturally occurring element present in many foodstuffs, is an essential trace element with many biological functions. In industry, inorganic Mn compounds have a range of different applications, although the majority of Mn is used to make alloys and steel. For the general population, the major source of exposure to Mn is dietary, although drinking water may constitute

Farida Louise Assem; Philip Holmes; Leonard Stephen Levy

2011-01-01

130

Apparatus and method for continuous separation of magnetic particles from non-magnetic fluids  

DOEpatents

A magnetic separator vessel (1) for separating magnetic particles from non-magnetic fluid includes a separation chamber having an interior and exterior wall, a top and bottom portion; a magnet (3) having first and second poles (2) positioned adjacent to the exterior wall, wherein the first pole is substantially diametrically opposed to the second pole; a inlet port (5) is directed into the top portion of the separation chamber, wherein the inlet port (5) is positioned adjacent to one of the first and second poles (2), wherein the inlet port (5) is adapted to transfer a mixture into the separation chamber; an underflow port (6) in communication with the bottom portion, wherein the underflow port (6) is adapted to receive the magnetic particles; and an overflow port (9) in communication with the separation chamber, wherein the overflow port (9) is adapted to receive the non-magnetic fluid.

Oder, Robin R. (Export, PA); Jamison, Russell E. (Lower Burrell, PA)

2010-02-09

131

Iron and nitrogen self-diffusion in non-magnetic iron nitrides  

SciTech Connect

The self-diffusion of iron and nitrogen is measured in nm range non-magnetic iron nitride thin films. Two non-magnetic iron nitrides, Fe{sub 2.23}N and FeN, were studied using neutron reflectivity. Neutron reflectivity with a depth resolution in the sub-nm range has a different scattering cross section for isotopes, providing a unique opportunity to measure very small diffusivities. The isotope heterostructure in thin film multilayers [Fe-N/{sup 57}Fe-N]{sub 10} and [Fe-N/Fe-{sup 15}N]{sub 10} were prepared using magnetron sputtering. It was observed that nitrogen diffuses slower than iron although the atomic size of iron is larger than that of nitrogen. It was found that a significantly larger group of N atoms participates in the diffusion process than of Fe, making N diffusion slower than that of Fe.

Gupta, Mukul; Gupta, Ajay [UGC-DAE Consortium for Scientific Research, University Campus, Khandwa Road, Indore-452 001 (India); Gupta, Rachana [Institute of Engineering and Technology, Khandwa Road, Devi Ahilya Vishwavidyalaya, Indore 452 017 (India); Stahn, J. [Laboratory for Neutron Scattering, Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland); Horisberger, M. [Laboratory for Developments and Methods, Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland); Wildes, A. [Institut Laue-Langevin, rue des Martyrs, 38042 Grenoble Cedex (France); Tayal, Akhil

2011-12-15

132

Development of Nonmagnetic Drill Collar Steel with High Stress Corrosion Cracking Resistance.  

National Technical Information Service (NTIS)

It has been clarified that the causes of stress corrosion cracking of conventional manganese-chromium steel for nonmagnetic drill collars are low corrosion resistance of the matrix, sensitization and residual stress. Based on this finding, an extralow-car...

T. Nakazawa H. Kimura Y Tsukano T. Suzuki T. Sakamoto

1989-01-01

133

REVIEW: Intermetallic compounds of rare earths and non-magnetic metals  

Microsoft Academic Search

A review is given of the physical properties, composition and crystal structure of intermetallic compounds formed between rare-earth elements and non-magnetic metals, with emphasis on the magnetic properties. Included are the properties of compounds in which the non-rare-earth component is a 4d or 5d transition element. Special consideration is given to the properties of pseudo-binary compounds. Results of magnetisation measurements,

K. Buschow

1979-01-01

134

FMR study of magnetic nanoparticles embedded in non-magnetic matrix  

Microsoft Academic Search

Purpose: The aim of this review is recapitulating the FMR study of low concentration of magnetic nanoparticles in non-magnetic matrices. Design\\/methodology\\/approach: Magnetic nanoparticles exhibit a variety of anomalous magnetic properties and they could be used for forming low concentration in different matrices. This way, they are being found to be allowing for effectively novel applications of FMR (ferromagnetic resonance) for

N. Guskos; E. A. Anagnostakis; A. Guskos

135

Axial oscillation of a magnetically levitated non-magnetic fluid column inside a straight magnetic pipe  

Microsoft Academic Search

The axial oscillation of a magnetically levitated non-magnetic liquid column in a magnetic fluid and a non-uniform weak magnetic field is studied theoretically and experimentally. The angular speed equation and wave speed equation of the interfacial wave are derived from the ferrohydrodynamics Navier–Stokes equation in a given magnetic field by (1) omitting the non-linear terms, (2) assuming that the undisturbed

Jianqiang Mai; Ryou Kobayashi; Masamichi Nakagawa; Shuzo Oshima; Ryuichiro Yamane

1999-01-01

136

Nonlinear motion of coupled magnetic vortices in ferromagnetic\\/non-magnetic\\/ferromagnetic trilayer  

Microsoft Academic Search

We have investigated a coupled motion of two vortex cores in ferromagnetic\\/nonmagnetic\\/ferromagnetic trilayer cynliders by means of micromagnetic simulation. Dynamic motion of two vortex with parallel and antiparallel relative chiralities of curling spins around the vortex cores have been examined after excitation by 1-ns pulsed external field. With systematic variation in non-magnetic spacer layer thickness from 0 to 20 nm,

Su-Hyeong Jun; Je-Ho Shim; Suhk-Kun Oh; Seong-Cho Yu; Dong-Hyun Kim; Brooke Mesler; Peter Fischer

2009-01-01

137

AC Losses in Multifilamentary Strands With Magnetic and Non-Magnetic Sheath Materials  

Microsoft Academic Search

AC applied magnetic field loss measurements have been performed on MgB2 superconducting strands. We measured strands with six untwisted filaments made via an in-situ route with Nb chemical barriers, a Cu-inter-filamentary matrix, and with either non-magnetic (glidcop) or magnetic (monel) outer sheaths. AC losses in magnetic fields applied perpendicular to the wire axis have been measured in fields up to

M. Majoros; Mike D. Sumption; M. A. Susner; M. Tomsic; M. Rindfleisch; E. W. Collings

2009-01-01

138

Preparation of chemical manganese dioxide from manganese sulfate  

Microsoft Academic Search

Chemical Manganese Dioxide (CMD) was prepared by an alkali-oxidation method. There are several virtues to this environmental friendly and clean process, including the nontoxic and harmless reagents and products, easy operations, no pollutants, easily obtained raw materials and moderate reaction conditions. The synthesized manganese dioxide was characterized by XRD and SEM. The particles were small, consisting primarily of ?-MnO2 and

Jiangang FU; Zhangxing HE; Hui WANG; Wei LIANG; Chao GUO

2010-01-01

139

Hot coal gas desulfurization with manganese-based sorbents. Annual report, September 1992--September 1993  

SciTech Connect

The focus of work being performed on Hot Coal Gas Desulfurization at the Morgantown Energy Technology Center is primarily in the use of zinc ferrite and zinc titanate sorbents; however, prior studies at the US Steel Fundamental Research Laboratories in Monroeville, PA, by E. T. Turkdogan indicated that an alternate sorbent, manganese dioxide-containing ore in mixture with alumina (75 wt % ore + 25 wt % Al{sub 2}O{sub 3}) may be a viable alternative to zinc-based sorbents. Manganese, for example, has a lower vapor pressure in the elemental state than zinc hence it is not as likely to undergo depletion from the sorbent surface upon loading and regeneration cycles. Also manganese oxide is less readily reduced to the elemental state than iron hence the range of reduction potentials for oxygen is somewhat greater than for zinc ferrite. In addition, thermodynamic analysis of the manganese-oxygen-sulfur system shows it to be less amenable to sulfation than zinc ferrite. Potential also exists for utilization of manganese at higher temperatures than zinc ferrite or zinc titanate. This Annual Topical Report documents progress in pelletizing and testing via thermo-gravimetric analysis of individual pellet formulations of manganese ore/ alumina combinations and also manganese carbonate/alumina with two binders, dextrin and bentonite. It includes the prior Quarterly Technical Reports which indicate that the manganese carbonate material, being of higher purity than the manganese ore, has a higher degree of sulfur capacity and more rapid absorption kinetics. A 2-inch fixed-bed reactor has been fabricated and is now ready for subjecting pellets to cyclic loading and regeneration.

Hepworth, M.T.

1993-12-01

140

Hot Coal Gas Desulfurization with manganese based sorbents. Quarterly report, August 1, 1993--September 30, 1993  

SciTech Connect

The focus of work being performed on Hot Coal Gas Desulfurization at the Morgantown Energy Technology Center is primarily in the use of zinc ferrite and zinc titanate sorbents; however, prior studies at the US Steel Fundamental Research Laboratories in Monroeville, PA, by E. T. Turkdogan indicated that an alternate sorbent, manganese dioxide-containing ore in mixture with alumina (75 wt % ore + 25 wt % Al{sub 2}O{sub 3}) may be a viable alternative to zinc-based sorbents. Manganese, for example, has a lower vapor pressure in the elemental state than zinc hence it is not as likely to undergo depletion from the sorbent surface upon loading and regeneration cycles. Also manganese oxide is less readily reduced to the elemental state than iron hence the range of reduction potentials for oxygen is somewhat greater than for zinc ferrite. In addition, thermodynamic analysis of the manganese-oxygen-sulfur system shows it to be less amenable to sulfation than zinc ferrite. Potential also exists for utilization of manganese at higher temperatures than zinc ferrite or zinc titanate. This report documents progress in pelletizing and testing via thermogravimetric analysis of individual pellet formulations of manganese ore/alumina combinations and also manganese carbonate/alumina with two binders, dextrin and bentonite. Preliminary results indicate that the manganese carbonate material, being of higher purity than the manganese ore, has a higher degree of sulfur capacity and more rapid absorption kinetics. A 2-inch fixed-bed reactor has been fabricated and is now ready for subjecting pellets to cyclic loading and regeneration.

Hepworth, M.T.

1993-10-01

141

Sulfide stress cracking resistance of nitrogen-strengthened stainless steel  

SciTech Connect

The paper describes sulfide stress cracking tests performed on a number of these alloys. Most were found to be somewhat susceptible to cracking, depending on the stress level. It was determined that this was due to their high manganese content. The mechanism responsible for cracking was not firmly established. One commercial nitrogen-strengthened stainless steel, XM19, was highly resistant to sulfide stress cracking despite a manganese content of 5%. This difference is attributed to the superior corrosion resistance of the alloy.

Gaugh, R.R.

1981-01-01

142

Trions as a Probe of Spin Injection Through II-VI Magnetic/Non-Magnetic Heterointerface.  

National Technical Information Service (NTIS)

The authors report on an efficient injection of spin-polarized electrons from Cadmium Magnesium Manganese Tellurium (CdMgMnTe) diluted magnetic semiconductor to nonmagnetic Cadmium Magnesium Tellurium (CdMgTe) quantum well structure. The electron spins we...

E. Janik J. Kossut L. Klopotowski M. Ghali M. Kutrowski

2002-01-01

143

Non-magnetic and magnetic impurity effects on superconductivity in the ternary iron-silicide Lu2FeSi  

NASA Astrophysics Data System (ADS)

We studied effect of non-magnetic and magnetic impurities on superconductivity in LuFeSi by investigating superconducting properties of (LuFeSi (R=Sc,Y, and Dy). The rapid depression of Tc by non-magnetic impurities reveals strong pair breaking by disorder, providing compelling evidence for the sign reversal of the superconducting order parameter in LuFeSi.

Watanabe, Tadataka; Okuyama, Hiroaki; Takase, Kouichi; Takano, Yoshiki

2010-12-01

144

Extraction of manganese from electrolytic manganese residue by bioleaching.  

PubMed

Extraction of manganese from electrolytic manganese residues using bioleaching was investigated in this paper. The maximum extraction efficiency of Mn was 93% by sulfur-oxidizing bacteria at 4.0 g/l sulfur after bioleaching of 9days, while the maximum extraction efficiency of Mn was 81% by pyrite-leaching bacteria at 4.0 g/l pyrite. The series bioleaching first by sulfur-oxidizing bacteria and followed by pyrite-leaching bacteria evidently promoted the extraction of manganese, witnessing the maximum extraction efficiency of 98.1%. In the case of sulfur-oxidizing bacteria, the strong dissolution of bio-generated sulfuric acid resulted in extraction of soluble Mn2+, while both the Fe2+ catalyzed reduction of Mn4+ and weak acidic dissolution of Mn2+ accounted for the extraction of manganese with pyrite-leaching bacteria. The chemical simulation of bioleaching process further confirmed that the acid dissolution of Mn2+ and Fe2+ catalyzed reduction of Mn4+ were the bioleaching mechanisms involved for Mn extraction from electrolytic manganese residues. PMID:21050747

Xin, Baoping; Chen, Bing; Duan, Ning; Zhou, Changbo

2010-11-02

145

Maternal–fetal Distribution of Manganese in the Rat Following Inhalation Exposure to Manganese Sulfate  

Microsoft Academic Search

Studies examining the pharmacokinetics of manganese during pregnancy have largely focused on the oral route of exposure and have shown that the amount of manganese that crosses the rodent placenta is low. However, limited information exists regarding the distribution of manganese in fetal tissues following inhalation. The objective of this study was to determine manganese body burden in CD rats

David C. Dorman; Anna M. McElveen; Marianne W. Marshall; Carl U. Parkinson; R. Arden James; Melanie F. Struve; Brian A. Wong

2005-01-01

146

The space density and X-ray luminosity function of non-magnetic cataclysmic variables  

NASA Astrophysics Data System (ADS)

We combine two complete, X-ray flux-limited surveys, the ROSAT Bright Survey (RBS) and the ROSAT North Ecliptic Pole (NEP) survey, to measure the space density (?) and X-ray luminosity function (?) of non-magnetic cataclysmic variables (CVs). The combined survey has a flux limit of FX? 1.1 × 10-12 erg cm-2 s-1 over most of its solid angle of just over ?, but is as deep as ?10-14 erg cm-2 s-1 over a small area. The CV sample that we construct from these two surveys contains 20 non-magnetic systems. We carefully include all sources of statistical error in calculating ? and ? by using Monte Carlo simulations; the most important uncertainty proves to be the often large errors in distances estimates. If we assume that the 20 CVs in the combined RBS and NEP survey sample are representative of the intrinsic population, the space density of non-magnetic CVs is ?. We discuss the difficulty in measuring ? in some detail - in order to account for biases in the measurement, we have to adopt a functional form for ?. Assuming that the X-ray luminosity function of non-magnetic CVs is a truncated power law, we constrain the power-law index to -0.80 ± 0.05. It seems likely that the two surveys have failed to detect a large, faint population of short-period CVs, and that the true space density may well be a factor of 2 or 3 larger than what we have measured; this is possible, even if we only allow for undetected CVs to have X-ray luminosities in the narrow range 28.7 < log(LX/erg s-1) < 29.7. However, ? as high as 2 × 10-4 pc-3 would require that the majority of CVs has X-ray luminosities below LX= 4 × 1028 erg s-1 in the 0.5-2.0 keV band.

Pretorius, Magaretha L.; Knigge, Christian

2012-01-01

147

Nonlinear motion of coupled magnetic vortices in ferromagnetic/non-magnetic/ferromagnetic trilayer  

SciTech Connect

We have investigated a coupled motion of two vortex cores in ferromagnetic/nonmagnetic/ferromagnetic trilayer cynliders by means of micromagnetic simulation. Dynamic motion of two vortex with parallel and antiparallel relative chiralities of curling spins around the vortex cores have been examined after excitation by 1-ns pulsed external field. With systematic variation in non-magnetic spacer layer thickness from 0 to 20 nm, the coupling between two cores becomes significant as the spacer becomes thinner. Significant coupling leads to a nonlinear chaotic coupled motion of two vortex cores for the parallel chiralities and a faster coupled gyrotropic oscillation for the antiparallel chiralities.

Jun, Su-Hyeong; Shim, Je-Ho; Oh, Suhk-Kun; Yu, Seong-Cho; Kim, Dong-Hyun; Mesler, Brooke; Fischer, Peter

2009-07-05

148

The non-magnetic surface of magnetic particles in nanostructured glass ceramics studied by SANS  

Microsoft Academic Search

Nanosized crystallites of ferrimagnetic magnetite, Fe3O4, were prepared by heat treatment of a rapidly quenched silicate glass melt of composition 27.4CaO–42.8SiO2–6.1B2O3–23.7Fe2O3 (mol%). SANS experiments of samples annealed at different heat treatment conditions were performed to determine the evolution and nature of the non-magnetic surface layer of the nanocrystals. It is suggested that this layer is formed by the distorted crystalline

A. Hoell; A. Wiedenmann; U. Lembke; R. Kranold

2000-01-01

149

21 CFR 73.2775 - Manganese violet.  

Code of Federal Regulations, 2013 CFR

...OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2775 Manganese violet. (a) Identity...Manganese violet is safe for use in coloring cosmetics generally, including cosmetics applied to the area of the eye, in...

2013-04-01

150

21 CFR 582.5452 - Manganese gluconate.  

Code of Federal Regulations, 2013 CFR

...AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5452 Manganese gluconate. (a) Product. Manganese gluconate. (b)...

2013-04-01

151

21 CFR 582.5449 - Manganese citrate.  

Code of Federal Regulations, 2013 CFR

...AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5449 Manganese citrate. (a) Product. Manganese citrate. (b)...

2013-04-01

152

21 CFR 582.5458 - Manganese hypophosphite.  

Code of Federal Regulations, 2013 CFR

...AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5458 Manganese hypophosphite. (a) Product. Manganese hypophosphite....

2013-04-01

153

Toxicological Profile for Manganese and Compounds.  

National Technical Information Service (NTIS)

The ATSDR Toxicological Profile is intended to characterize succinctly the toxicological and health effects information for manganese compounds. It identifies and reviews the key literature that describes manganese compounds' toxicological properties. Oth...

1992-01-01

154

Morphology and Precipitation Kinetics of MnS in Low-Carbon Steel During Thin Slab Continuous Casting Process  

Microsoft Academic Search

The morphology of manganese sulfide formed during thin slab continuous casting process in low-carbon steel produced by compact strip production (CSP) technique was investigated. Using transmission electron microscopy analysis, it was seen that a majority of manganese sulfides precipitated at austenite grain boundaries, the morphologies of which were spherical or close to the spherical shape and the size of MnS

Hao YU; Yong-lin KANG; Zheng-zhi ZHAO; Hao SUN

2006-01-01

155

New Developments with C-Mn-Ni in High Strength Steel Weld Metals — Part B. Mechanical Properties  

Microsoft Academic Search

Microstructure and properties have been studied for high strength steel weld metals with varia- tions in carbon, manganese and nickel. Based on neural network modelling, experimental welds were made using shielded metal arc welding with manganese at 0.5 or 2.0 wt. % and nickel at 7 or 9 wt. %. Additional welds were made where carbon was varied between 0.03

E. Keehan; L. Karlsson; H.-O. Andrén; L.-E. Svensson

156

Steel: Lightweight Steel Containers.  

National Technical Information Service (NTIS)

Using NICE3 funds, Dispensing Containers Corporation has found an exciting new method for manufacturing steel dispensing containers with an average of 40% less raw material than conventional manufacturing processes. Order this new fact sheet now and disco...

Steve Blazek

1999-01-01

157

MANGANESE OXIDE REDUCTION IN LABORATORY MICROCOSMS  

Microsoft Academic Search

Manganese biogeochemistry holds special interest for the characterization of passive treatment systems designed to treat acidic mine waters while meeting enforceable effluent discharge limits set for manganese. In the present study, an initial anoxic enrichment culture was developed for use as an inoculum in experimental systems. Standard anoxic microcosms capable of reducing manganese from ~n~' to ~n'' were established from

Richard A. Royer; Richard F. Unz

2006-01-01

158

Manganese oxide cathodes for rechargeable batteries  

Microsoft Academic Search

Manganese oxides are considered as promising cathodes for rechargeable batteries due to their low cost and low toxicity as well as the abundant natural resources. In this dissertation, manganese oxides have been investigated as cathodes for both rechargeable lithium and alkaline batteries. Nanostructured lithium manganese oxides designed for rechargeable lithium cells have been synthesized by reducing lithium permanganate with methanol

Dongmin Im

2002-01-01

159

Autonomic Function in Manganese Alloy Workers  

Microsoft Academic Search

The observation of orthostatic hypotension in an index case of manganese toxicity lead to this prospective attempt to evaluate cardiovascular autonomic function and cognitive and emotional neurotoxicity in eight manganese alloy welders and machinists. The subjects consisted of a convenience sample consisting of an index case of manganese dementia, his four co-workers in a “frog shop” for gouging, welding, and

William W. Barrington; Carol R. Angle; Nancy K. Willcockson; Marjorie A. Padula; Thomas Korn

1998-01-01

160

21 CFR 184.1461 - Manganese sulfate.  

Code of Federal Regulations, 2010 CFR

...sulfate. (a) Manganese sulfate (MnSO4 ·H2...obtained by reacting manganese compounds with...byproduct in the manufacture of hydroquinone...on a slurry of manganese dioxide in sulfuric...with solid ferrous sulfate and coal,...

2010-01-01

161

21 CFR 184.1461 - Manganese sulfate.  

Code of Federal Regulations, 2010 CFR

...sulfate. (a) Manganese sulfate (MnSO4 ·H2...obtained by reacting manganese compounds with...byproduct in the manufacture of hydroquinone...on a slurry of manganese dioxide in sulfuric...with solid ferrous sulfate and coal,...

2009-04-01

162

Diode laser heat treatment of lithium manganese oxide films  

NASA Astrophysics Data System (ADS)

The crystallization of lithium manganese oxide thin films prepared by radio frequency magnetron sputtering on stainless steel substrates under 10 Pa argon pressure is demonstrated by a laser annealing technique. Laser annealing processes were developed as a function of annealing time and temperature with the objective to form an electrochemically active lithium manganese oxide cathode. It is demonstrated, that laser annealing with 940 nm diode laser radiation and an annealing time of 2000 s at 600 °C delivers appropriate parameters for formation of a crystalline spinel-like phase. Characteristic features of this phase could be detected via Raman spectroscopy, showing the characteristic main Raman band at 627 cm-1. Within cyclic voltammetric measurements, the two characteristic redox pairs for spinel lithium manganese oxide in the 4 V region could be detected, indicating that the film was well-crystallized and de-/intercalation processes were reversible. Raman post-analysis of a cycled cathode showed that the spinel-like structure was preserved within the cycling process but mechanical degradation effects such as film cracking were observed via scanning electron microscopy. Typical features for the formation of an additional surface reaction layer could be detected using X-ray photoelectron spectroscopy.

Pröll, J.; Kohler, R.; Mangang, A.; Ulrich, S.; Bruns, M.; Seifert, H. J.; Pfleging, W.

2012-04-01

163

Carcinogenicity, mutagenicity and teratogenicity of manganese compounds.  

PubMed

Manganese, an essential trace element, is one of the most used metals in the industry. Recently, several new manganese compounds have been introduced as fungicide, as antiknock agent in petrol and as contrasting agent in nuclear magnetic resonance tomography. Manganese displays a somewhat unique behaviour with regard to its toxicity. It is relatively non-toxic to the adult organism except to the brain where it causes Parkinson-like symptoms when inhaled even at moderate amounts over longer periods of time. Relatively high doses of manganese affect DNA replication and repair in bacteria and causes mutations in microorganism and mammalian cells although the Ames test does not appear to be particularly responsive to manganese. In mammalian cells, manganese causes DNA damage and chromosome aberrations. Information on organic manganese derivatives is still insufficient. Large amounts of manganese affect fertility in mammals and are toxic to the embryo and foetus. The fungicide MANEB and the contrasting agent MnDPDP also can be embryotoxic, but the latter only at doses much higher than those clinically employed. Information on the anti-knock agent MMT is inadequate. On the other hand, manganese deficiency can also affect fertility and be teratogenic. Information on cancer due to manganese is scanty but the results available do not indicate that inorganic manganese is carcinogenic. More information is desirable with regard to the organic manganese derivatives. It may surprise that an agent that causes mutations is not also carcinogenic. The experience with manganese shows that conclusions with regard to carcinogenicity of an agent based on the observation of mutations are subject to uncertainties. Altogether, it appears that, because of the very high doses at which positive effects have been found, manganese would not represent a significant carcinogenic risk to the population and workers. Care must, however, be exercised with respect to central-nervous symptoms after chronic exposure and with respect to effects on the embryo. Pregnant women should not be exposed to manganese at the work place. PMID:11923066

Gerber, G B; Léonard, A; Hantson, Ph

2002-04-01

164

Corrosion Behavior of High Nitrogen Nickel-Free Fe-16Cr-Mn-Mo-N Stainless Steels  

NASA Astrophysics Data System (ADS)

The purpose of the current study is to develop austenitic nickel-free stainless steels with lower chromium content and higher manganese and nitrogen contents. In order to prevent nickel-induced skin allergy, cobalt, manganese, and nitrogen were used to substitute nickel in the designed steel. Our results demonstrated that manganese content greater than 14 wt pct results in a structure that is in full austenite phase. The manganese content appears to increase the solubility of nitrogen; however, a lower corrosion potential was found in steel with high manganese content. Molybdenum appears to be able to increase the pitting potential. The effects of Cr, Mn, Mo, and N on corrosion behavior of Fe-16Cr-2Co-Mn-Mo-N high nitrogen stainless steels were evaluated with potentiodynamic tests and XPS surface analysis. The results reveal that anodic current and pits formation of the Fe-16Cr-2Co-Mn-Mo-N high nitrogen stainless steels were smaller than those of lower manganese and nitrogen content stainless steel.

Chao, K. L.; Liao, H. Y.; Shyue, J. J.; Lian, S. S.

2013-06-01

165

Origin of Oceanic Manganese Minerals  

Microsoft Academic Search

A criterion is suggested for discrimination between ferromanganese oxide minerals, deposited after the introduction of manganese and associated elements in sea water solution at submarine vulcanism, and minerals which are slowly formed from dilute solution, largely of continental origin. The simultaneous injection of thorium into the ocean by submarine vulcanism is indicated, and its differentiation from continental thorium introduced into

G. Arrhenius; J. Mero; J. Korkisch

1964-01-01

166

Ionization Ability of Manganese Nanoparticles  

NASA Astrophysics Data System (ADS)

Manganese oxide nanoparticles (Mn-O NPs) were prepared through our novel method as reagents for laser desorption/ionization mass spectrometry (LDI-MS). Through the control of the reaction time in the chemical preparation method (0.5, 1, and 5 h), we succeeded in preparing three different types of manganese oxide particles. The particles were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, and DC magnetization measurements. These characterization results indicated that the manganese ions oxidized in aqueous alkaline solution, and that the spinel structure was retained for the Mn3O4 phase, which then gradually changed into the MnO2 phase. The mass spectra of substance P (MW = 1347.6) were measured by MALDI-TOF mass spectrometry with Mn-O NPs. The Mn-O NPs that reacted with 3-aminopropyltriethoxysilane(?-APTES) for 1 h or 5 h had higher ionization abilities than those reacted for 0.5 h. These different abilities are attributed to the different crystal structures of the prepared manganese oxides.

Hiroki, Tomoyuki; Shigeoka, Daiki; Kimura, Shinji; Mashino, Toshiyuki; Taira, Shu; Ichiyanagi, Yuko

2011-05-01

167

Manganese Star Iota Coronae Borealis.  

National Technical Information Service (NTIS)

An abundance analysis of the manganese star Iota Coronae Borealis is carried out in detail by making use of a model atmosphere with theta sub e = 0.458, log g = 3.7, N(He)/N(H) = 0.12. The energy distribution and H gamma profile are reproduced by this mod...

J. E. Ross L. H. Aller

1969-01-01

168

The search for magnetic fields in mercury-manganese stars  

NASA Astrophysics Data System (ADS)

Mercury-manganese (HgMn) stars were considered to be non-magnetic, showing no evidence of surface spots. However, recent investigations revealed that some stars in this class possess an inhomogeneous distribution of chemical elements on their surfaces. According to our current understanding, the most probable mechanism of spot formation involves magnetic fields. Taking the advantage of a newly-built polarimeter attached to the HARPS spectrometer at the ESO 3.6m-telescope, we performed a high-precision spectropolarimetric survey of a large group of HgMn stars. The main purpose of this study was to find out how typical it is for HgMn stars to have weak magnetic fields. We report no magnetic field detection for any of the studied objects, with a typical precision of the longitudinal field measurements of 10 G and down to 1 Gauss for some of the stars. We conclude that HgMn stars lack large-scale magnetic fields typical of spotted magnetic Ap stars and probably lack any fields capable of creating and sustaining chemical spots. Our study confirms that alongside the magnetically altered atomic diffusion, there must be other structure formation mechanism operating in the atmospheres of late-B main sequence stars.

Makaganiuk, Vitalii; Kochukhov, Oleg; Piskunov, Nikolai; Jeffers, Sandra V.; Johns-Krull, Christopher M.; Keller, Christoph U.; Rodenhuis, Michiel; Snik, Frans; Stempels, Henricus C.; Valenti, Jeff A.

2011-07-01

169

Tunable double negative band structure from non-magnetic coated rods  

NASA Astrophysics Data System (ADS)

A system of periodic poly-disperse-coated nano-rods is considered. Both the coated nano-rods and the host material are non-magnetic. The exterior nano-coating has a frequency-dependent dielectric constant and the rod has a high dielectric constant. A negative effective magnetic permeability is generated near the Mie resonances of the rods, while the coating generates a negative permittivity through a field resonance controlled by the plasma frequency of the coating and the geometry of the crystal. The explicit band structure for the system is calculated in the subwavelength limit. Tunable pass bands exhibiting negative group velocity are generated and correspond to simultaneously negative effective dielectric permittivity and magnetic permeability. These can be explicitly controlled by adjusting the distance between the rods, the coating thickness and the rod diameters.

Chen, Yue; Lipton, Robert

2010-08-01

170

Preparation of high Jc YBCO coated conductors on non-magnetic Ni W substrates  

NASA Astrophysics Data System (ADS)

We report on the preparation of high Jc YBCO coated conductors on non-magnetic Ni-W substrates. In order to minimize the deleterious effects of tungsten oxide formation on the epitaxial growth of oxide buffer layers and YBCO films, an electrodeposition approach has been developed to epitaxially grow an about 2 µm Ni layer (Ed-Ni layer) on Ni-3 at% W tapes. With this method, the surface for epitaxy of the first oxide seed layer is not exposed to the Ni-W surface, and high quality CeO2/yttria-stabilized zirconia/CeO2 buffer layers and YBCO films have been grown on the Ed-Ni/Ni-3 at% W substrates by pulsed laser deposition. A critical current density, Jc, of 1.49 MA cm-2 has been achieved at 75.2 K and in a magnetic field of 83 mT.

Chen, Jun; Spagnoal, Priscilla; Bhattacharya, Raghu N.; Ren, Zhifeng

2004-10-01

171

Magnetic levitation by induced eddy currents in non-magnetic conductors and conductivity measurements  

NASA Astrophysics Data System (ADS)

We report a study on magnetic levitation by induced ac currents in non-magnetic conductors at low frequencies. Our discussion, based on Faraday's induction law, allows us to distinguish the two components of the current responsible for levitation and heating, respectively. The experimental evaluation of the levitation force in a copper ring revealed the accuracy of our analysis, clearly illustrating its asymptotic behaviour versus frequency, and validating it for the qualitative analysis of magnetic levitation and heating in conductors of different shapes such as tubes and discs, composed of collections of conductive loops. The analysis of the results allows precise values of its electrical conductivity to be found. With the help of a simulation technique, this work also reveals the progressive deformation undergone by magnetic induction lines due to magnetic screening when frequency increases.

Íñiguez, J.; Raposo, V.; Flores, A. G.; Zazo, M.; Hernández-López, A.

2005-11-01

172

The non-magnetic surface of magnetic particles in nanostructured glass ceramics studied by SANS  

NASA Astrophysics Data System (ADS)

Nanosized crystallites of ferrimagnetic magnetite, Fe3O4, were prepared by heat treatment of a rapidly quenched silicate glass melt of composition 27.4CaO-42.8SiO2-6.1B2O3- 23.7Fe2O3 (mol%). SANS experiments of samples annealed at different heat treatment conditions were performed to determine the evolution and nature of the non-magnetic surface layer of the nanocrystals. It is suggested that this layer is formed by the distorted crystalline structure and thermally induced effects at the surface region and by the formation of a segregation shell enriched with Fe2O3 and subsequent surface oxidation of the Fe3O4 nanocrystals as well.

Hoell, A.; Wiedenmann, A.; Lembke, U.; Kranold, R.

2000-03-01

173

Electron tunneling in a non-magnetic heterostructure in presence of both Dresselhaus and Rashba spin-orbit terms  

NASA Astrophysics Data System (ADS)

In this paper, the electron tunneling in a non-magnetic heterostructure is theoretically investigated in presence of both Dresselhaus and Rashba spin-orbit terms. We find that the considerable spin polarization can be achieved in such a non-magnetic structure, and in the different electron energy regions or for the different barrier heights, the Dresselhaus and Rashba spin-orbit couplings play a different role in the spin polarization. We also find that the transmission probability and the spin polarization both show a periodic profile with the increase of the well width.

Lu, Jian-Duo

2010-11-01

174

Soluble manganese removal by porous media filtration.  

PubMed

Filtration experiments were conducted to investigate soluble manganese removal in granular media filtration; sand, manganese oxide coated sand (MOCS), sand + MOCS (1:1) and granular activated carbon (GAC) were used as filter media. Manganese removal, manganese oxide accumulation, turbidity removal, and regeneration of MOCS under various conditions were examined. Soluble manganese removal by the MOCS column was rapid and efficient; most of the removal happened at the top (e.g. 5 cm) of the filter. When filter influent with an average manganese concentration of 0.204 mg l(-1) was fed through the filter columns, the sand + MOCS and MOCS columns removed 98.9% and 99.2% of manganese, respectively. However, manganese removal in sand and the GAC columns was not significant during the initial stage of filtration, but after eight months of filter run they could remove 99% and 35% of manganese, respectively. It was revealed that partial replacement of sand with MOCS showed comparable manganese removal to that of the MOCS filter media. PMID:19149348

Kim, J; Jung, S

2008-12-01

175

IMPROVEMENT OF SCREENING FOR MANGANESE EFFICIENCY BY PRODUCING SEED WITH SIMILAR MANGANESE CONTENT IN DIFFERENT GENOTYPES AND GENETIC STOCKS  

Microsoft Academic Search

Genetic improvement of manganese efficiency of crops demands a precise bioassay that avoids the confounding effect of seed manganese on the bioassay for the trait, for a proper comparison of the genotypes the seed manganese content must be similar. Variation in seed manganese can be minimized by the addition of manganese to individual seeds to be planted providing the effect

H. Khabaz-Saberi; R. D. Graham

2002-01-01

176

Fatigue Property of Stainless Steel FES Electrode in Hanks' Solution  

Microsoft Academic Search

Fatigue property of the wire rope with 19 strands used as an FES electrode was investigated. The wire rope was made of high manganese high nitrogen austenitic stainless steel. Fatigue life of the wire rope in Hanks' solution at 310 K was evaluated using a dual-driven rotating-bending fatigue machine. Each wire of the rope was worn out and the cross

Y. Iguchi; T. Narushima; K. Suzuki; S. Yoshida; M. Watanabe; T. Kinami; C. Ouchi

177

IR-Spectroscopic investigations on phosphated galvanized steel  

Microsoft Academic Search

Hopeite-type phosphate coatings in which zinc is replaced by other metals like nickel, manganese and magnesium are of great interest as conversion coatings on galvanized steel in the automotive and appliance industries. The analytical characterization of such coatings produced in special processes is not possible by XRD because the different types of hopeite are isomorphic. In this paper it is

K. Molt; M. Pohl; R. Seidel; B. Mayer

1994-01-01

178

40 CFR 721.10201 - Cobalt lithium manganese nickel oxide.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Cobalt lithium manganese nickel oxide. 721...Chemical Substances § 721.10201 Cobalt lithium manganese nickel oxide. ...The chemical substance identified as cobalt lithium manganese nickel...

2013-07-01

179

40 CFR 721.10011 - Barium calcium manganese strontium oxide.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Barium calcium manganese strontium oxide. ...Chemical Substances § 721.10011 Barium calcium manganese strontium oxide. ...The chemical substance identified as barium calcium manganese strontium...

2010-07-01

180

40 CFR 721.10011 - Barium calcium manganese strontium oxide.  

Code of Federal Regulations, 2010 CFR

...2009-07-01 2009-07-01 false Barium calcium manganese strontium oxide. ...Chemical Substances § 721.10011 Barium calcium manganese strontium oxide. ...The chemical substance identified as barium calcium manganese strontium...

2009-07-01

181

40 CFR 721.10011 - Barium calcium manganese strontium oxide.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Barium calcium manganese strontium oxide. 721.10011...Chemical Substances § 721.10011 Barium calcium manganese strontium oxide. (a...chemical substance identified as barium calcium manganese strontium oxide (PMN...

2013-07-01

182

40 CFR 721.10003 - Manganese heterocyclic tetraamine complex (generic).  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Manganese heterocyclic tetraamine complex (generic...Chemical Substances § 721.10003 Manganese heterocyclic tetraamine complex (generic...chemical substances identified generically as manganese heterocyclic tetraamine...

2010-07-01

183

40 CFR 721.10003 - Manganese heterocyclic tetraamine complex (generic).  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Manganese heterocyclic tetraamine complex (generic...Chemical Substances § 721.10003 Manganese heterocyclic tetraamine complex (generic...chemical substances identified generically as manganese heterocyclic tetraamine...

2013-07-01

184

Manganese oxide reduction in laboratory microcosms  

Microsoft Academic Search

Manganese biogeochemistry holds special interest for the characterization of passive treatment systems designed to treat acidic\\u000a mine waters while meeting enforceable effluent discharge limits set for manganese. In the present study, an initial anoxic\\u000a enrichment culture was developed for use as an inoculum in experimental systems. Standard anoxic microcosms capable of reducing\\u000a manganese from Mn4+ to Mn2+ were established from

Richard A. Royer; Richard F. Unz

1999-01-01

185

Microalgal-facilitated bacterial oxidation of manganese  

Microsoft Academic Search

In the presence of unicellular microalgae, bacterial manganese oxidation was increased by up to ten times the rate produced by bacterial oxidation alone. Azide-poisoned controls demonstrated that the manganese-oxidizing bacteria were active in the algal-bacterial oxidation of manganese. Scanning electron microscopy showed that oxide formation occurred in a number of structurally different deposits on the surface of the alga. Studies

R M Stuetz; A C Greene; J C Madgwick

1996-01-01

186

Methylcyclopentadienyl Manganese Tricarbonyl: Effect on Manganese Emissions from Vehicles on the Road  

Microsoft Academic Search

This note describes some measurements of manganese concentrations and manganese emission rates, categorized as to vehicle type, from cars and trucks at two tunnels on the Pennsylvania Turnpike. These measurements were made during the period that methylcyclopentadienyl manganese tricarbonyl (MMT) came into use as an alternative to organo-lead compounds for improving combustion in gasoline engines.

William R. Pierson; Douglas E. McKee; Wanda W. Brachaczek; James W. Butler

1978-01-01

187

Influence of Dietary Manganese on the Pharmacokinetics of Inhaled Manganese Sulfate in Male CD Rats  

Microsoft Academic Search

Concerns exist as to whether individuals with relative manga- nese deficiency or excess may be at increased risk for manganese toxicity following inhalation exposure. The objective of this study was to determine whether manganese body burden influences the pharmacokinetics of inhaled manganese sulfate (MnSO4). Postna- tal day (PND) 10 rats were placed on either a low (2 ppm), sufficient (10

David C. Dorman; Melanie F. Struve; R. Arden James; Brian E. McManus; Marianne W. Marshall; Brian A. Wong

2001-01-01

188

Thermal expansion of manganese carbonate  

Microsoft Academic Search

Precision lattice parameters of manganese carbonate have been determined at different temperatures by the X-ray powder method in the temperature range 28 to 265° C. The data has been used to evaluate, by a graphical method, the two coefficients of thermal expansion,$$\\\\begin{gathered} \\\\alpha _\\\\parallel = 22.942 \\\\times 10^{ - 6} - 5.555 \\\\times 10^{ - 8} T + 3.361 \\\\times

K. V. Krishna Rao; K. Satyanaryana Murthy

1970-01-01

189

Manganese Nodule Exploration System Manganknollen - Explorationssystem.  

National Technical Information Service (NTIS)

Different tools for manganese nodule exploration are thoroughly investigated. Certain tools are selected applying technical and economical criteria. Three optimized exploration systems are designed as examples. (Author)

G. Braun H. Ristow H. Weichart

1973-01-01

190

Battles with Iron: Manganese in Oxidative Stress Protection*  

PubMed Central

The redox-active metal manganese plays a key role in cellular adaptation to oxidative stress. As a cofactor for manganese superoxide dismutase or through formation of non-proteinaceous manganese antioxidants, this metal can combat oxidative damage without deleterious side effects of Fenton chemistry. In either case, the antioxidant properties of manganese are vulnerable to iron. Cellular pools of iron can outcompete manganese for binding to manganese superoxide dismutase, and through Fenton chemistry, iron may counteract the benefits of non-proteinaceous manganese antioxidants. In this minireview, we highlight ways in which cells maximize the efficacy of manganese as an antioxidant in the midst of pro-oxidant iron.

Aguirre, J. Dafhne; Culotta, Valeria C.

2012-01-01

191

Austenite decomposition in ternary manganese, molybdenum and tungsten steels  

NASA Astrophysics Data System (ADS)

A survey of austenite decomposition in Fe-(0.1, 0.2)C-(3, 4.2)Mn has revealed kinetic and morphological transitions which take place at substantial undercoolings below the paraequilibrium Ae3 temperature. An unusually long interval of transformation stasis was found in Fe-0.1C-3Mn, during which time the ferrite was free of carbides. A nodular product containing rod particles was observed in several of these alloys. The grain boundary bainite (GBB) and twin boundary bainite (TBB) morphologies at the bay in Fe-0.24C-4Mo were significantly more complex than previously assumed, with differing arrangements of bainite subunits; their thickening rates also differed. TEM revealed 10 nm steps at the bainite-austenite interfaces in GBB. Mo enrichment was found within GBB-austenite interfaces and extended ˜10 nm into the austenite. The M2C carbides are always enriched in Mo, possessing a non-equilibrium Mo content at earlier reaction times. The energies stored in the ferrite-carbide interfacial area and in carbides possessing non-equilibrium Fe/Mo ratios were considered to reduce the driving force for diffusion by up to 20%. GBB and TBB were found at and above the bay in Fe-0.3C-6.3W, while the bainite formed below the bay consisted of elongated subunits. M6C was found at all temperatures, while M2C was found only below the bay, both of which exhibited W partition. A dark-etching constituent of very high carbide density transformed the remaining pools of austenite at the late stages of reaction, a result consistent with the level of carbon in austenite rising with time. Transitions in carbide morphology were explored in Fe-0.2C-63W. At lower reaction temperatures, M6C precipitates with ferrite. At higher temperatures the cellular precipitation of quasilamellar M 6C in austenite occurs, and is considered to take place inside the ferrite + austenite + M6C three-phase field. The austenite inside the quasilamellar carbide nodules reverts to ferrite at long times, indicating a non-equilibrium transformation path.

Hackenberg, Robert Errol

192

Cryogenic mechanical properties of high-manganese steel weldments  

Microsoft Academic Search

The structural alloys used in fusion reactor magnets of the next generation are required to have a 4.2 K yield strength and fracture toughness combination superior to that of alloys used currently. An alloy of nominal composition 18Mn-5Ni-16Cr-0.22N after proper thermomechanical treatment approaches the JAERI projected requirements and exceeds the proposed US requirements for 4.2 K yield strength and fracture

J. W. Chan; J. W. Jr. Morris

1985-01-01

193

Revealing the Degree of Magnetic Frustration by Non-Magnetic Impurities  

SciTech Connect

Imaging the magnetic fields around a non-magnetic impurity can provide a clear benchmark for quantifying the degree of magnetic frustration. Focusing on the strongly frustrated J{sub 1}-J{sub 2} model and the spatially anisotropic J{sub 1a}-J{sub 1b}-J{sub 2} model, very distinct low energy behaviors reflect different levels of magnetic frustration. In the J{sub 1}-J{sub 2} model, bound magnons appear trapped near the impurity in the ground state and strongly reduce the ordered moments for sites proximal to the impurity. In contrast, local moments in the J{sub 1a}-J{sub 1b}-J{sub 2} model are enhanced on the impurity neighboring sites. These theoretical predictions can be probed by experiments such as nuclear magnetic resonance and scanning tunneling microscopy, and the results can elucidate the role of frustration in antiferromagnets and help narrow the possible models to understand magnetism in the iron pnictdies.

Not Available

2011-08-12

194

Room temperature ferromagnetism in non-magnetic doped TiO2 nanoparticles  

NASA Astrophysics Data System (ADS)

Room-temperature ferromagnetism in non-magnetic doped TiO2 semiconductor nanoparticles is analyzed in the present work. Undoped and N-doped TiO2 nanoparticles were obtained employing sol-gel procedure using urea as the nitrogen source. The obtained gels were first dried at 70 °C and afterwards calcined in air at 300 °C. A residual carbon concentration was retained in the samples as a consequence of the organic decomposition process. Post-annealing treatments at 300 °C under air and vacuum conditions were also performed. The crystallographic structure of nanoparticles was analyzed by X-ray diffraction, obtaining a single anatase crystalline phase after the calcinations (mean nanoparticle diameters around 5-8 nm). SQUID magnetometry was employed to analyze the magnetic response of the samples. Whereas for the undoped samples synthesized with hydrolysis rate h = 6, paramagnetic like behavior is observed at room temperature, the N-doped nanoparticles (h = 3) show a weak ferromagnetic response (saturation magnetization ~10-3 emu/g). Moreover, a clear reinforcement of the room-temperature ferromagnetism response is found with the post-annealing treatments, in particular that performed in vacuum. Thus, the results indicate the dominant role of the oxygen stoichiometry and the oxygen vacancies in the room temperature ferromagnetic response of these TiO2 nanoparticles.

Gómez-Polo, C.; Larumbe, S.; Pastor, J. M.

2013-05-01

195

Design of a non-magnetic shielded and integrated electromagnetic tomography system  

NASA Astrophysics Data System (ADS)

The detected signal of an electromagnetic tomography (EMT) system is weak and can be easily disturbed by the capacitance coupling and external magnetic field. In order to improve the performance of the EMT system, simulation of a non-magnetic shield design was done and an integrated EMT system based on a field programmable gate array (FPGA) is presented in this paper. By the orthogonal experiments, the influence of the material, height and inner radius of the shield was investigated according to the uniformity criterion of sensitivity. Besides, the principle for the selection of the shield parameters was put forward. In the present EMT system, a direct digital synthesizer module, digital demodulation module, MCU control module, DA interface module, AD interface module and USB communication module were all integrated in a FPGA chip. The integration of the system is increased and the difficulty of debugging is decreased. The influence of the excitation signal frequency, the sample frequency and the accumulation number of the multiply accumulator intellectual property core on the demodulation was analysed and a general principle was proposed. The system was evaluated and an optimal excitation frequency was chosen. A back-projection algorithm based on a truncated singular value was selected to reconstruct the different distributions, and the speed of reconstruction was 27 frames s-1. The design scheme can be easily transplanted to other electrical tomography systems.

Wang, Chao; Zhang, Junqing; Li, Fanwei; Cui, Ziqiang; Xu, Chuanjin

2011-10-01

196

Non-magnetic impurity induced magnetism in rutile TiO2:K compounds  

NASA Astrophysics Data System (ADS)

Recent ab initio studies have theoretically predicted room temperature ferromagnetism in several oxide materials of the type AO2 in which the cation A4+ is substituted by a non-magnetic element of the 1 A column. Our purpose is to address experimentally the possibility of magnetism in Ti1-xKxO2 compounds. The samples have been synthesized via the solid state route method at equilibrium. Our study has shown that Ti1-xKxO2 is thermodynamically unstable and leads to a phase separation, in contradiction with the hypothesis of ab initio calculations. In particular, the crystalline TiO2 grains appear to be surrounded by K-based phase. The oxidization state of the Ti ion is found to be in Ti4+ as confirmed from the x-ray photoelectron spectra measurement. Nevertheless, K:TiO2 compounds exhibit weak paramagnetism with the highest magnetic moment of ˜0.5 ?B K-1 but no long-range ferromagnetic order. The observed moment in these compounds remains much smaller than the predicted moment of 3 ?B by ab initio calculation. The apparent contradictions between our experiments and first-principles studies are discussed.

Srivastava, S. K.; Lejay, P.; Barbara, B.; Boisron, O.; Pailhès, S.; Bouzerar, G.

2011-11-01

197

Induced Magneto-transport Effects in Non-magnetic Metals on Yttrium Iron Garnet  

NASA Astrophysics Data System (ADS)

Yttrium iron garnet (YIG) was called ``spin Seebeck insulator,'' for it supports heat-generated pure spin currents. Pt thin film, with strong spin-orbit interaction, is used as a spin current generator or detector based on the spin Hall effect or the inverse spin Hall effect. The combination of these two materials plays a very important role in spintronics. A recent magnetotransport study shows strong evidence of a magnetic proximity effect in thin Pt films deposited on YIG. Here, we present a magneto-transport study of several non-magnetic (NM) metal films (e.g. Pt, Pd) on YIG films grown on gadolinium gallium garnet substrates with laser molecular beam epitaxy. The anisotropic magnetoresistance (AMR) and anomalous Hall effect (AHE) reveal clear ferromagnetic characteristics in NM films. The magnitude of the AHE angle ? in Pd/YIG structure increases with decreasing temperature, while ? in Pt/YIG structure has a sign reversal at an intermediate temperature. Both AMR and AHE have been investigated as the NM film thickness is varied and an optimal effective thickness is identified. The effect of annealing has also been studied and the results are consistent with the observed thickness dependence. In thin NM films, a ln(T) temperature dependence with a resistivity minimum is observed at low temperatures, suggesting that the Kondo effect may be relevant. Detailed discussions about the origin of these effects will be presented.

Lin, Tao; Tang, Chi; Shi, Jing

2013-03-01

198

EFFECTS OF MANGANESE ON THYROID HORMONE HOMEOSTASIS  

PubMed Central

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, lyases, isomerases, ligases and glutamine synthetase. Environmental or occupational exposure to high levels of manganese can cause a neuropathy resembling idiopathic Parkinson’s disease, commonly referred to as manganism. Manganism and Parkinson’s disease are both characterized by motor deficits and damage to nuclei of the basal ganglia, particularly the substantia nigra, with altered dopamine (and its metabolites) contributing to these disorders. Dopamine, a major neurotransmitter plays a crucial role in the modulation of the cognitive function, working memory and/or attention of the prefrontal cortex and the hippocampus. Dopamine is also a known inhibitory modulator of thyroid stimulating hormone (TSH) secretion. The involvement of dopamine and dopaminergic receptors in neurodevelopment, as well as TSH modulation, led us to hypothesize that excessive manganese exposure may lead to adverse neurodevelopmental outcomes due to the disruption of thyroid homeostasis via the loss of dopaminergic control of TSH regulation of thyroid hormones. This disruption may alter thyroid hormone levels, resulting in some of the deficits associated with gestational exposure to manganese. While the effects of manganese in adult populations are relatively well documented, comprehensive data on its neurodevelopmental effects are sparse. Given the importance of this topic, we review the potential participation of thyroid hormone dyshomeostasis in the neurodevelopmental effects of manganese positing the hypotheses that manganese may directly or indirectly affect thyroid function by injuring the thyroid gland or dysregulating dopaminergic modulation of thyroid hormone synthesis.

Soldin, OP; Aschner, M

2007-01-01

199

Mechanical properties and machinability of a high-strength, medium-carbon, microalloyed steel  

Microsoft Academic Search

The development of a high-strength (tensile strength beyond 900 N\\/mm2), medium-carbon, vanadium microalloyed steel for hot-forged automotive components has been reviewed in the paper.\\u000a \\u000a The influence of different alloying elements was investigated. The most effective elements to increase the strength were chromium\\u000a and manganese. In TEM investigation, it was found that, in comparison with the lower-strength melt, chromium plus manganese

V. Ollilainen; H. Hurmola; H. Pöntinen

1984-01-01

200

Phase transformations and the structure of high-strength low-carbon steels  

Microsoft Academic Search

1.Manganese has much greater effect than nickel on the hardenability of low-carbon steels. Partial substitution of nickel by manganese helps form a martensitic structure at minimal cooling rates.2.The cooling rate from the austenite region has a small effect on the copper content in the solid solution due to the high solubility of this element in austenite, which has high stability.3.The

B. M. Bronfin; I. Yu. Pyshmintsev; V. I. Kalmykov

1993-01-01

201

Hydrogen embrittlement of structural steels.  

SciTech Connect

Carbon-manganese steels are candidates for the structural materials in hydrogen gas pipelines, however it is well known that these steels are susceptible to hydrogen embrittlement. Decades of research and industrial experience have established that hydrogen embrittlement compromises the structural integrity of steel components. This experience has also helped identify the failure modes that can operate in hydrogen containment structures. As a result, there are tangible ideas for managing hydrogen embrittement in steels and quantifying safety margins for steel hydrogen containment structures. For example, fatigue crack growth aided by hydrogen embrittlement is a key failure mode for steel hydrogen containment structures subjected to pressure cycling. Applying appropriate structural integrity models coupled with measurement of relevant material properties allows quantification of safety margins against fatigue crack growth in hydrogen containment structures. Furthermore, application of these structural integrity models is aided by the development of micromechanics models, which provide important insights such as the hydrogen distribution near defects in steel structures. The principal objective of this project is to enable application of structural integrity models to steel hydrogen pipelines. The new American Society of Mechanical Engineers (ASME) B31.12 design code for hydrogen pipelines includes a fracture mechanics-based design option, which requires material property inputs such as the threshold for rapid cracking and fatigue crack growth rate under cyclic loading. Thus, one focus of this project is to measure the rapid-cracking thresholds and fatigue crack growth rates of line pipe steels in high-pressure hydrogen gas. These properties must be measured for the base materials but more importantly for the welds, which are likely to be most vulnerable to hydrogen embrittlement. The measured properties can be evaluated by predicting the performance of the pipeline using a relevant structural integrity model, such as that in ASME B31.12. A second objective of this project is to enable development of micromechanics models of hydrogen embrittlement in pipeline steels. The focus of this effort is to establish physical models of hydrogen embrittlement in line pipe steels using evidence from analytical techniques such as electron microscopy. These physical models then serve as the framework for developing sophisticated finite-element models, which can provide quantitative insight into the micromechanical state near defects. Understanding the micromechanics of defects can ensure that structural integrity models are applied accurately and conservatively.

Somerday, Brian P.

2010-06-01

202

Manganese poisoning and the attack of trivalent manganese upon catecholamines.  

PubMed

Human manganese poisoning or manganism results in damage to the substantia nigra of the brain stem, a drop in the level of the inhibitory neurotransmitter dopamine, and symptoms resembling those of Parkinson's disease. Manganic (Mn3+) manganese ions were shown to be readily produced by O-2 in vitro and spontaneously under conditions obtainable in the human brain. Mn3+ as its pyrophosphate complex was shown to rapidly and efficiently carry out four-electron oxidations of dopamine, its precursor dopa (3,4-dihydroxyphenylalanine), and its biosynthetic products epinephrine and norepinephrine. Mn3+-pyrophosphate was shown to specifically attack dihydroxybenzene derivatives, but only those with adjacent hydroxyl groups. Further, the addition of Mn2+-pyrophosphate to a system containing a flux of O2- and dopamine greatly accelerated the oxidation of dopamine. The oxidation of dopamine by Mn3+ neither produced nor required O2, and Mn3+ was far more efficient than Mn2+, Mn4+ (MnO2), O2-, or H2O2 in oxidizing the catecholamines. A higher oxidation state, Mn(OH)3, formed spontaneously in an aqueous Mn(OH)2 precipitate and slowly darkened, presumably being oxidized to MnO2. Like reagent MnO2, it weakly catalyzed dopamine oxidation. However, both MnO2 preparations showed dramatically increased abilities to oxidize dopamine in the presence of pyrophosphate due to enhancement of the spontaneous formation of the Mn3+ complex. These results strongly suggest that the pathology of manganese neurotoxicity is dependent on the ease with which simple Mn3+ complexes are formed under physiological conditions and the efficiency with which they destroy catecholamines. PMID:3039917

Archibald, F S; Tyree, C

1987-08-01

203

Health Hazard Evaluation Determination Report No. HE 80-51-709, CF and I Steel Corporation, Pueblo, Colorado.  

National Technical Information Service (NTIS)

Environmental surveys were conducted and blood samples were collected on February 11 to 13, 1980, to evaluate exposures to lead (7439921), iron oxide, manganese (7439965), and magnesium (7439954) in the steel production scrap yard area at CF and I Steel C...

B. J. Gunter M. J. Coye

1980-01-01

204

The magnetism of metallic manganese alloys  

SciTech Connect

The magnetic excitations in antiferromagnetic manganese-copper and manganese-iron alloys are characterized by high spin-wave velocities, and energy gap at long wavelengths and wavelength dependent damping. There are strong elastic constant anomalies above T[sub N] as well as magnetoelastic distortions below T[sub N]. The theoretical explanation of these effects is reviewed.

Holden, T.M. (Atomic Energy of Canada Ltd., Chalk River, ON (Canada)); Mikke, K. (Institute of Atomic Energy, Otwock-Swierk (Poland)); Fawcett, E. (Toronto Univ., ON (Canada)); Fernandez-Baca, J.A. (Oak Ridge National Lab., TN (United States))

1992-01-01

205

The magnetism of metallic manganese alloys  

SciTech Connect

The magnetic excitations in antiferromagnetic manganese-copper and manganese-iron alloys are characterized by high spin-wave velocities, and energy gap at long wavelengths and wavelength dependent damping. There are strong elastic constant anomalies above T{sub N} as well as magnetoelastic distortions below T{sub N}. The theoretical explanation of these effects is reviewed.

Holden, T.M. [Atomic Energy of Canada Ltd., Chalk River, ON (Canada); Mikke, K. [Institute of Atomic Energy, Otwock-Swierk (Poland); Fawcett, E. [Toronto Univ., ON (Canada); Fernandez-Baca, J.A. [Oak Ridge National Lab., TN (United States)

1992-12-31

206

Manganese potentiates nitric oxide production by microglia.  

PubMed

Manganese toxicity has been associated with clinical symptoms of neurotoxicity which are similar to the symptoms observed in Parkinson's disease. Earlier reports indicated that reactive microglia was present in the substantia nigra of patients with Parkinson's disease. Using N9 microglial cells, the current study was designed to determine whether high levels of manganese were associated with microglial activation. Results indicated that manganese significantly increased the bacterial lipopolysaccharide-induced nitric oxide production. This potent activity of manganese was not shared by other transition metals tested, including iron, cobalt, nickel, copper and zinc. Immunohistochemical staining and Western blot analysis indicated that manganese increased the cellular production of inducible nitric oxide synthase. Northern blot analysis indicated that manganese likely increased iNOS gene transcription since this agent increased the mRNA level of the inducible nitric oxide synthase. In contrast to other transition metals tested, manganese did not appear to be cytotoxic to microglial cells. These results suggested that manganese could induce sustained production of neurotoxic nitric oxide by activated microglial cells, which might cause detrimental consequences to surrounding neurons. PMID:10320780

Chang, J Y; Liu, L Z

1999-05-01

207

Structural Features of Manganese Precipitating Bacteria  

NASA Astrophysics Data System (ADS)

Studies of biological communities of the past (and their associated activities) are usually dependent upon preservation of fossil material. With bacteria this rarely occurs because of the absence of sufficient fossilizable cellular material. However, some bacteria deposit metabolic products that can, conditions allowing, be preserved indefinitely. In particular, manganese and iron depositing bacteria have the capacity to form preservable microfossils. In order to better understand these microfossils of the past, we have examined present day morphologies of manganese oxidizing bacteria. These bacteria are highly pleomorphic, depending on the growth medium, the age of the culture, and the extent of manganese oxidation. Transmission electron microscopy indicates that manganese may be deposited either intra-or extra-cellularly. The prognosis of the use of morphological information for the interpretation of ancient and modern manganese deposits is discussed.

Nealson, Kenneth H.; Tebo, Bradley

1980-06-01

208

Optimized Welding of Stainless Steel Tubings for Corrosion Free Exposure to HBr Gas  

NASA Astrophysics Data System (ADS)

Hydrogen bromide gas phase corrosion of welded 316L electropolished stainless steel tubings to be used for the distribution of ultra clean gases has been investigated by using two techniques: one is leaching of the corroded tubings and subsequent chemical analysis of the dissolved metallic elements, the other one is bromine penetration depth at the stainless steel surface by Auger spectroscopy. These test procedures were applied to optimize the back shielding gas used for orbital welding of such tubings. A correlation is found between the oxygen concentration in the back shielding gas and the gas phase corrosion. Purified argon as back shielding gas insures best corrosion resistance due to the minimum thickness of superficial iron oxide, and maximal chromium concentration underlying the top iron/manganese oxide layer. Tubings made of stainless steel containing very small concentration of manganese exhibit lower level of corrosion. A corrosion enhancement mechanism by manganese is proposed.

Hattori, Taeko; Takagi, Hideki; Boireau, Alain; Chevrel, Henri; Ozawa, Eiichi; Friedt, Jean

1994-04-01

209

Manganese regulates expression of manganese peroxide by Phanerochaete chrysosporium  

SciTech Connect

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 cells grown in the presence of Mn. MnP mRNA was detected by Northern (RNA) blot analysis only in cells grown in the presence of Mn. If Mn was added to 4-day-old nitrogen-limited Mn-deficient cultures, extracellular MnP activity appeared after 6 h and reached a maximum after 18 h. Both actinomycin D and cycloheximide inhibited the induction of MnP activity by Mn. These results indicate that Mn, the substrate of the enzyme, is involved in the transcriptional regulation of the MnP gene.

Brown, J.A.; Glenn, J.K.; Gold, M.H. (Oregon Graduate Institute of Science and Technology, Beaverton (USA))

1990-06-01

210

Thermal expansion of manganese carbonate  

Microsoft Academic Search

Precision lattice parameters of manganese carbonate have been determined at different temperatures by the X-ray powder method\\u000a in the temperature range 28 to 265 C. The data has been used to evaluate, by a graphical method, the two coefficients of\\u000a thermal expansion,?\\u000a ? along thec-axis and?\\u000a ? at right-angles to thec-axis. The temperature-dependence of the coefficients is represented by the

K. V. Krishna Rao; K. Satyanaryana Murthy

1970-01-01

211

Spin-Galvanic Effect and Spin Orientation by Current in Non-Magnetic Semiconductors  

NASA Astrophysics Data System (ADS)

Lately, there is much interest in the use of the spin of carriers in semiconductor quantum well (QW) structures together with their charge to realize novel concepts like spintronics. The necessary conditions to develop spintronic devices are high spin polarizations in QWs and a large spin-splitting of subbands in k-space. The latter is important for the ability to control spins with an external electric field by the Rashba effect. Significant progress has been achieved recently in generating large spin polarizations, in demonstrating the Rashba splitting and also in using the splitting for manipulating the spins. At the same time as these conditions are fulfilled and spins are polarized in-plane of QW, it has been shown that the spin polarization itself drives a current resulting in the spin galvanic effect [1,2]. The spin-galvanic effect is due to asymmetric spin-flip scattering of spin polarized carriers and it is determined by the process of spin relaxation. In some optical experiments, where circularly polarized radiation is used to orient spins, the photocurrent may represent a sum of spin-galvanic and circular photogalvanic effects effects.2,3 Both effects provide methods to determine spin relaxation times and the relative strength of the Rashba/Dresselhaus spin-splitting in semiconductor quantum wells.2 The inverse spin-galvanic effect4 has also been detected demonstrating that electric current in non-magnetic but gyrotropic QWs results in a non-equilibrium spin orientation. Just recently a first direct experimental proof of this effect was obtained in semiconductor QWs5,6 as well as in strained bulk material.7 Microscopically the effect is a consequence of spin-orbit coupling which lifts the spin-egeneracy in k-space of charge carriers together with spin dependent relaxation. Note from Publisher: This article contains the abstract only.

Ganichev, S. D.

212

The Structural Stability of Manganese Oxide Electrodes for Lithium Batteries  

Microsoft Academic Search

Manganese oxides are of interest as insertion electrodes for rechargeable 3 V and 4 V lithium batteries. During discharge, lithium ions are inserted into the manganese oxide host structure with a concomitant reduction of the manganese ions; the reverse process occurs on charge. The cycle life of these batteries is critically dependent on the ability of the manganese oxide structure

Michael M. Thackeray

1997-01-01

213

Reduced-activation austenitic stainless steels: The Fe--Mn--Cr--C system  

SciTech Connect

Nickel-free manganese-stabilized steels are being developed for fusion-reactor applications. As the first part of this effort, the austenite-stable region in the Fe--Mn--Cr--C system was determined. Results indicated that the Schaeffler diagram developed for Fe--Ni--Cr--C alloys cannot be used to predict the constituents expected for high-manganese steels. This is true because manganese is not as strong an austenite stabilizer relative to delta-ferrite formation as predicted by the diagram, but it is a stronger austenite stabilizer relative to martensite than predicted. Therefore, the austenite-stable region for Ne--Mn--Cr--C alloys occurs at lower chromium and hugher combinations of manganese and carbon than predicted by the Schaeffler diagram. Development of a manganese-stabilized stainless steel should be possible in the composition range of 20 to 25% Mn, 10 to 15% Cr, and 0.01 to 0.25%C. Tensile behavior of an Fe--20%Mn--12%Cr--0.25%C alloy was determined. The strength and ductility of this possible base composition was comparable to type 316 stainless steel in both the solution-annealed and cold-worked condition.

Klueh, R.L.; Maziasz, P.J.

1988-01-01

214

Approach towards full Heusler alloy based CPP-GMR: from Ag and non-magnetic Heusler to binary intermetallic spacers  

NASA Astrophysics Data System (ADS)

Recently, it has been demonstrated that GMR response can be significantly enhanced by incorporating high spin polarization ferromagnetic (FM) full Heulser alloy into spin valve nano-structures. Experimental results for two types of non-magnetic spacers (i) elemental metal [1] and (ii) non-magnetic Heusler alloy spacers [2] deserve careful comparison. More practical (110) textured combination of Co2MnGe (CMG) and non-magnetic Heusler alloy Rh2CuSn (RCS) [2] have been used to build test hard disk drive [3]. In this work, we investigate the mechanism of spin dependent interface scattering for (001) CMG/Ag/CMG (Case1) and (110) CMG/RCS/CMG (Case2) models on the basis of ab-initio electronic structure calculations. We find that in both cases GMR has significant contribution from the spin dependent interface scattering. We propose new binary intermetallic spacer materials Al2Au and Cu3Sn as an alternative to Ag and RCS spacers. [4pt] [1] T.Iwase et.al. Appl.Phys.Express, 2, 063003 (2009).[0pt] [2] K. Nikolaev et.al. App.Phys. Lett., 94, 222501 (2009)

Mryasov, Oleg; Faleev, Sergey; Karthik, S. V.

2011-03-01

215

Manganese metallurgy review. Part I: Leaching of ores\\/secondary materials and recovery of electrolytic\\/chemical manganese dioxide  

Microsoft Academic Search

The world rapidly growing demand for manganese has made it increasingly important to develop processes for economical recovery of manganese from low grade manganese ores and other secondary sources. Part I of this review outlines metallurgical processes for manganese production from various resources, particularly focusing on recent developments in direct hydrometallurgical leaching and recovery processes to identify potential sources of

Wensheng Zhang; Chu Yong Cheng

2007-01-01

216

The reduction and oxidation behaviour of manganese oxides  

Microsoft Academic Search

The reduction of manganese oxides with methane was studied to investigate the suitability of manganese as an oxygen storage compound. Manganese oxides are reduced by CH4 to a lower-valent manganese oxide, producing CO2 and water. Once the manganese oxide is reduced, it can be regenerated, i.e. reoxidised. By integrating this exothermic oxidation cycle with endothermic methane reforming, a new setup

E. R. Stobbe; B. A. de Boer; J. W. Geus

1999-01-01

217

Correcao de elementos interferentes: uma otimizacao necessaria para analise de Co em acos Mn, via espectrometria de fluorescencia de raios-x. (Interfering elements correction: a necessary optimization for Co analysis from Mn steels, using x-ray fluorescence spectrometry).  

National Technical Information Service (NTIS)

The interference of manganese, copper and aluminium in cobalt analysis from manganese steels is studied. The method used in this experiment is X-ray fluorescence spectrometry and a comparative study is also presented. (M.V.M.). (Atomindex citation 24:0441...

A. R. C. Bello C. Carvalho M. L. Cunha

1991-01-01

218

Effect of calcium and cerium on the structure and properties of 08Kh18G8N2T steel and of welded joints in this steel  

Microsoft Academic Search

In this work, we examined the effect of microadditions of cerium and calcium, on the phase composition and properties of 08KhlSGSN2T steel. The investigations were conducted on the metal of melts of 08KhlSG8N2T steel of four modifications (Table I): with the content of the main elements, i.e., chrome, nickel, manganese, corresponding to the minimum and maximum limits specified by GOST

G. A. Sal'nikov; M. A. Khubrikh; A. S. Zubchenko; Zh. A. Lepilina; I. I. Zhukova

1986-01-01

219

Wear evaluation of high interstitial stainless steel  

SciTech Connect

A new series of high nitrogen-carbon manganese stainless steel alloys are studied for their wear resistance. High nitrogen and carbon concentrations were obtained by melting elemental iron-chromium-manganese (several with minor alloy additions of nickel, silicon, and molybdenum) in a nitrogen atmosphere and adding elemental graphite. The improvement in material properties (hardness and strength) with increasing nitrogen and carbon interstitial concentration was consistent with previously reported improvements in similar material properties alloyed with nitrogen only. Wear tests included: scratch, pin-on-disk, sand-rubber-wheel, impeller, and jet erosion. Additions of interstitial nitrogen and carbon as well as interstitial nitrogen and carbide precipitates were found to greatly improve material properties. In general, with increasing nitrogen and carbon concentrations, strength, hardness, and wear resistance increased.

Rawers, J.C.; Tylczak, J.H.

2008-07-01

220

The Structure and Properties of Plasma Sprayed Iron Oxide Doped Manganese Cobalt Oxide Spinel Coatings for SOFC Metallic Interconnectors  

Microsoft Academic Search

Manganese cobalt oxide spinel doped with Fe2O3 was studied as a protective coating on ferritic stainless steel interconnects. Chromium alloying causes problems at high\\u000a operation temperatures in such oxidizing conditions where chromium compounds evaporate and poison the cathode active area,\\u000a causing the degradation of the solid oxide fuel cell. In order to prevent chromium evaporation, these interconnectors need\\u000a a protective

Jouni Puranen; Juha Lagerbom; Leo Hyvärinen; Mikko Kylmälahti; Olli Himanen; Mikko Pihlatie; Jari Kiviaho; Petri Vuoristo

2011-01-01

221

BORON, MANGANESE, MOLYBDENUM, NICKEL, SILICON, AND VANADIUM  

Technology Transfer Automated Retrieval System (TEKTRAN)

Although boron, manganese, molybdenum, nickel, silicon and vanadium are not considered significant nutritional concerns, they have received some attention in the sports nutrition field because of findings suggesting that they could enhance strength, performance and endurance in athletic activities. ...

222

21 CFR 184.1446 - Manganese chloride.  

Code of Federal Regulations, 2013 CFR

...ore (MnO2 ), or reduced manganese ore in hydrochloric acid. The resulting solution is neutralized to precipitate heavy metals, filtered, concentrated, and crystallized. (b) The ingredient meets the specifications of the Food...

2013-04-01

223

21 CFR 184.1452 - Manganese gluconate.  

Code of Federal Regulations, 2013 CFR

...OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY...by reacting manganese carbonate with gluconic acid in aqueous medium and then crystallizing the product. (b)...

2013-04-01

224

Rechargeable manganese oxide batteries. (Genopladelige manganoxid batterier).  

National Technical Information Service (NTIS)

Former work on lithium and sodium batteries proved the feasibility of making solid state cells with high energy density and reversibility. The utility of manganese oxides as cathode material in rechargeable alkali metal solid state intercalation batteries...

B. Zachau-Christensen K. West S. Skaarup

1992-01-01

225

Ultrasonic Relaxation in Manganese Sulfate Solutions.  

National Technical Information Service (NTIS)

A two step, three state association-dissociation model was used to interpret the ultrasonic absorption data for manganese sulfate in aqueous solution, combining data obtained in the present work with literature data. The relaxation parameters were calcula...

L. G. Jackopin E. Yeager

1970-01-01

226

The Manganese Nodule Industry: A First Approximation.  

National Technical Information Service (NTIS)

The objectives of this paper are (1) to describe what the industrial organization may be when manganese nodule production occurs; (2) to develop a technological framework for applied science investigators that shows where their work fits into the industry...

H. D. Drechsler

1972-01-01

227

Manganese in copper solvent extraction and electrowinning  

Microsoft Academic Search

In the copper solvent extraction–electrowinning (SX–EW) process, Mn2+ entrained in the organic solution may be transferred to the loaded electrolyte. It will then be oxidised during copper EW. The high-oxidation state manganese formed may in turn return to the SX circuit. The presence of high-oxidation state manganese has been associated with deterioration in the phase separation characteristics of the organic

C. Y. Cheng; C. A. Hughes; K. R. Barnard; K. Larcombe

2000-01-01

228

Neuropsychological function in manganese alloy plant workers  

Microsoft Academic Search

ObjectivesThe objective was to investigate potential nervous system effects of manganese (Mn) exposure in workers employed in manganese-alloy-producing plants.MethodsOne hundred male Mn alloy plant workers were compared with 100 age-matched referents. The subjects were examined with a comprehensive neuropsychological test battery. Exposure was assessed by measurement of Mn concentrations in the workroom air, blood and urine.ResultsThe geometric mean (GM) concentration

Rita Bast-Pettersen; Dag G. Ellingsen; Siri M. Hetland; Yngvar Thomassen

2004-01-01

229

Lithium manganese oxides for rechargeable lithium batteries  

Microsoft Academic Search

Lithium manganese spinel compounds HT-LiMn2O4 (HT means high temperature) synthesized at > 700 °C have high capacity in the 4 V range (LixMn2O4, x ? 1), However, lithium manganese oxides LT-LiMn2O4 (LT means low temperature) synthesized at temperatures lower than 400 °C, resemble to the spinel structure and tend to have a reduced capacity in the 4 V range. We

Yoshiaki Nitta; Kazuhiro Okamura; Masatoshi Nagayama; Akira Ohta

1997-01-01

230

A comparative evaluation of cobalt chromium oxide, cobalt manganese oxide, cobalt manganese oxide, and copper manganese oxide as catalysts for the water-gas shift reaction  

Microsoft Academic Search

Cobalt chromium oxide, cobalt manganese oxide, and copper manganese oxide have been compared as catalysts for the water-gas shift reaction. Cobalt chromium oxide and cobalt manganese oxide catalysts can give both high activity and long lifetimes for this reaction. Cobalt chromium oxide catalysts display higher activity compared to the other catalyst systems and this is shown that both the cobalt

G. J. Hutchings; R. G. Copperthwaite; F. M. Gottschalk; R. Hunter; J. Mellor; S. W. Orchard; T. Sangiorgio

1992-01-01

231

Effectiveness of different sources of manganese foliar sprays in alleviating manganese deficiency of Lupinus angustifolius L. grown on manganese deficient soils in western Australia  

Microsoft Academic Search

Responses of narrow?leafed sweet lupins (Lupinus angustifolius L.) to foliar sprays of different sources of manganese (Mn) were compared in field experiments in three years at six sites in Western Australia. The relative effectiveness of manganese chelate (EDTA; 14% Mn) and manganese sulfate (25% Mn) applied as foliar sprays for alleviating Mn deficiency of lupins was assessed. Each source was

R. F. Brennam

1996-01-01

232

Spin dependent transport studies in magnetic, non-magnetic, antiferromagnetic, and half metals  

NASA Astrophysics Data System (ADS)

This thesis consists of three studies of Current-Perpendicular-to-the-Planes (CPP) Magnetoresistance (MR) of sputtered ferromagnetic/non-magnetic (F/N) multilayers. (a) The first study involves a double-blind comparison of our measurements of the interface specific resistance AR (area A through which the CPP current flows times the CPP resistance R) of Pd/Ir interfaces with no-free-parameter calculations. (b) The second study is of spin relaxation within the antiferromagnets (AF) IrMn and FeMn and at their interfaces with Cu. (c) The third study is of the MR of multilayers involving a nominal half-metal Heusler alloy, Co2Fe(Al0.5Si0.5) (CFAS). A true half-metal should give an especially large CPP-MR. This study involves a different sample geometry, combining optical lithography and ion-beam etching, with epitaxial sputtering at elevated temperatures. (a) For four pairs of lattice-matched metals (Ag/Au, Co/Cu, Fe/Cr, and Pt/Pd) having the same crystal structure and the same lattice parameter to within ˜1%, no-free-parameter calculations of 2AR, twice the interface specific resistance AR have agreed with measured values to within mutual uncertainties. For three pairs, the measured values were known when the calculations were made. For the fourth pair, Pt/Pd, they were not. In contrast, calculations for non-matched pairs, where the lattice parameters differed by 5% or more, disagreed with measured values. In this thesis we study a fifth pair, Pd and Ir, where the lattice parameter mismatch is intermediate, 1.3%. The project was done double-blind with theory collaborators Wang and Xia, with experiment and calculations shared only after both groups settled on their separate values. The values for Pd/Ir calculated with the same assumptions used previously were just outside of uncertainty of the measured ones. An improved calculation gave agreement between the two values. (b) Antiferromagnets (AFs) play important roles in CPP-MR devices as sources of pinning for F-layers in exchange-biased spin-valves (EBSVs), and are also part of a burgeoning field of AF spintronics. For both structures, it is important to understand spin-relaxation within sputtered AFs and at AF/N interfaces. A prior study of spin-relaxation in sputtered FeMn found strong spin-flipping at FeMn/Cu interfaces, but was unable to determine the size of spin-flipping within the FeMn itself. In this thesis we find strong spin-flipping at IrMn/Cu interfaces and confirm strong spin-flipping at FeMn/Cu interfaces. We also discovered an interesting new phenomenon, a weak magnetic dependence of AR in Py, that makes us unable to put a tight bound on the bulk spin-diffusion lengths in sputtered IrMn or FeMn. But these lengths are probably short. (c) The CPP-MR of an F/N multilayer will be enhanced by an F-metal with high spin scattering asymmetry, making such a multilayer more competitive for devices. Half-metallic ferromagnetic metals, such as Heusler alloys, are predicted to have high asymmetry. Experiments with the Heusler alloy CFAS have shown both large Tunneling Magnetoresistance (TMR) and large CPP-MR for multilayers with non-superconducting electrodes sputtered at room temperature and then post-annealed to 500°C. In this thesis we attempt to optimize epitaxial growth using high temperature sputtering to produce highly ordered Heusler alloys grown on superconducting electrodes. We are able to grow CFAS epitaxially, but have obtained maximum CPP MR only about one-third (40%) as large as we expected.

Acharyya, Rakhi

233

Investigation of non-magnetic alloys for the suppression of tritium permeation. Final report  

SciTech Connect

This report describes a small (300 man hour) literature survey relating to the suppression of tritium loss by permeation through the walls of fusion reactors. The program was based on prior in-house Thermacore work to suppress hydrogen permeation into high temperature (800/sup 0/C) heat pipes. The Thermacore approach involves selection of a steel with a small (.5 to 5%) aluminum content. The aluminum is diffused to the surface and oxidized. The present work was aimed at identification of alloys which might combine low tritium permeation with other properties desired in fusion reactor vessels, heat exchangers, lithium-handling plumbing and other components likely to contain tritium. These properties include low radiation damage, low magnetic permeability, high temperature strength, and compatibility with potential heat transfer and blanket materials. The work consisted of two tasks: Problem Definition and Literature Search and Analysis.

Not Available

1980-07-01

234

Giant magnetoimpedance in composite wires with insulator layer between non-magnetic core and soft magnetic shell  

NASA Astrophysics Data System (ADS)

A method for calculation of the magnetoimpedance in composite wires having an insulator layer between non-magnetic core and soft magnetic shell is described. It is assumed that the magnetic shell has a helical anisotropy and the driving current flows through the core only. The distribution of eddy currents and expressions for the impedance are found by means of a solution of Maxwell equations taking into account the magnetization dynamics within the shell governed by the Landau Lifshitz equation. The effect of the insulator layer on the magnetoimpedance is analyzed.

Buznikov, N. A.; Antonov, A. S.; Granovsky, A. B.; Kim, C. G.; Kim, C. O.; Li, X. P.; Yoon, S. S.

2006-05-01

235

Spin-dependent resonant tunneling in a periodic non-magnetic heterostructure with spin-orbit effects  

NASA Astrophysics Data System (ADS)

We theoretically investigate the electron transport in a periodic non-magnetic heterostructure with both Dresselhaus and Rashba spin-orbit effects. We show that the transport properties obviously depend on the number of periods and the large spin polarization can be achieved in such a structure. We also show that for m>1, the resonance splitting occurs in the transmission curves of both spin-up and spin-down electrons when the transmission curves are plotted as a function of the electron energy or the well width.

Lu, Jian-Duo; Xia, Xiong-Ping; Yi, Lin; Wang, Yu-Hua

2010-07-01

236

Low-activation Mn–Cr austenitic stainless steel with further reduced content of long-lived radioactive elements  

Microsoft Academic Search

Low-activation austenitic stainless steel based on Mn–Cr non-magnetic steels has been developed. The alloying elements of long-life activation, such as Ni, Mo and Co, were eliminated and substituted with Mn along with an addition of N. A Mn–Cr austenitic stainless steel, 24.5Mn–13.5Cr–0.02C–0.2N, has been developed successfully. Examined material properties, including mechanical, thermal and magnetic properties, as well as weldability and

Masanori Onozuka; Tomikane Saida; Shouzou Hirai; Mikio Kusuhashi; Ikuo Sato; Tsuyoshi Hatakeyama

1998-01-01

237

Fatigue crack growth properties of a cryogenic structural steel at liquid helium temperature  

Microsoft Academic Search

The structural materials of the coils of superconducting magnets utilized in thermonuclear fusion reactors are used at liquid helium (4.2 K) temperatures and are subjected to repeated thermal stresses and electromagnetic forces. A high strength, high toughness austenitic stainless steel (12Cr-12Ni-10Mn-5Mo-0.2N) has recently been developed for large, thick-walled components used in such environments. This material is non-magnetic even when subjected

Shinji Konosu; Tomohiro Kishiro; Ogi Ivano; Yoshihiko Nunoya; Hideo Nakajima; Hiroshi Tsuji

1996-01-01

238

Processing of Long-Length YBCO Coated Conductors Based on Stainless Steel Tapes  

Microsoft Academic Search

Recent progress is reported in the development of long lengths (up to 100 m) of YBCO coated conductors with good mechanical stability and improved critical current homogeneity. A non-magnetic CrNi stainless steel tape, 0.1 mm thick, is employed as a substrate tape. Prior to deposition, the tape is coated with yttria stabilized zirconia in the form of a bi-axially textured

A.. Usoskin; L.. Kirchhoff; J.. Knoke; B.. Prause; A.. Rutt; V.. Selskij; D. E. Farrell

2007-01-01

239

Manganese-electrolysed slag treatment: bioleaching of manganese by Fusarium sp.  

PubMed

A fungi strain named Fusarium sp. was isolated from manganese-electrolysed slag by using a gradient dilution spread plate method, identified by 26S RNA sequence analysis and phylogenetic tree analysis, and explored for the bioleaching capacity to manganese (II) from manganese-electrolysed slag in liquid mineral medium under different environmental conditions, including system temperature, incubator rotation speed and initial pH value. DNA sequence and phylogenetic analysis indicated the name of this fungi strain, that is, Fusarium sp., and higher bioleaching efficiencies (71.6%) of manganese by this fungi were observed when the bioleaching was carried out under the optimized conditions as follows: contact time: 72 h; system temperature: 28 degrees C; inoculums concentration: 2% (v/v); incubator rotation speed: 150 rpm; pH 4.0. Because of its low cost, environment friendliness and better efficiency, the bioleaching technique will have a significant impact on manganese-electrolysed slag pollution mitigation. PMID:22856303

Cao, Jian-Bing; Li, Xiao-Ming; Ouyang, Yu-Zhu; Zheng, Wei; Wang, Dong-Bo; Shen, Ting-Ting; Yue, Xiu; Yang, Qia

2012-06-01

240

The micro-mechanisms of tempered martensite embrittlement in 4340-type steels  

Microsoft Academic Search

A study of the micro-mechanisms of tempered martensite embrittlement was made on a series of 4340-type steels in which the\\u000a contents of manganese, silicon, and trace impurities, especially phosphorus and sulfur, were varied. One plain-carbon steel\\u000a was also examined. The study employed Charpy impact tests and four-point slow-bend tests coupled with an elastic-plastic stress\\u000a analysis, as well as scanning electron

N. Bandyopadhyay; C. J. McMahon

1983-01-01

241

Improving the tribological characteristics of powder steel parts via multicomponent diffusion saturation of working surfaces  

Microsoft Academic Search

This paper discusses a new method for chemical heat treatment – multicomponent diffusion saturation of the surface of powder-steel\\u000a products with chromium, silicon, and manganese in order to improve product performance, especially with respect to tribological\\u000a properties. The samples to be saturated were fabricated from powdered iron, and powdered 40, 60, and 40N2M steel. The control\\u000a samples consisted of hot-stamped

A. B. Korostelev; D. A. Chumak-Zhun

2008-01-01

242

The influence of drawing speed on properties of TRIP steel wires  

Microsoft Academic Search

Purpose: The aim of this paper is to determine the influence of drawing speed of TRIP steel wires on their properties. Design\\/methodology\\/approach: The heat treatment of steel containing 0.09 % carbon, 1.57 % manganese and 0.9 % silicon allows to obtain TRIP type structure. The wires were drawn with different drawing speed. After drawing mechanical properties of wires were determined

M. Suliga; Z. Muskalski; S. Wiewiórowska

243

Embrittlement of RPV steels; An atom probe tomography perspective  

SciTech Connect

Atom probe tomography has played a key role in the understanding of the embrittlement of neutron irradiated reactor pressure vessel steels through the atomic level characterization of the microstructure. Atom probe tomography has been used to demonstrate the importance of the post weld stress relief treatment in reducing the matrix copper content in high copper alloys, the formation of {approx}-nm-diameter copper-, nickel-, manganese- and silicon-enriched precipitates during neutron irradiation in copper containing RPV steels, and the coarsening of these precipitates during post irradiation heat treatments. Atom probe tomography has been used to detect {approx}2-nm-diameter nickel-, silicon- and manganese-enriched clusters in neutron irradiated low copper and copper free alloys. Atom probe tomography has also been used to quantify solute segregation to, and precipitation on, dislocations and grain boundaries.

Miller, Michael K [ORNL; Russell, Kaye F [ORNL

2007-01-01

244

Linear Stability Analysis Of A Magnetic/Non-Magnetic Fluid Coflow In The Presence Of A Magnetic Field  

NASA Astrophysics Data System (ADS)

Ferrofluids are colloidal suspensions of magnetic nanoparticles in carrier liquids. Being both magnetic and a liquid, they are readily maneuvered from a distance using magnetic fields. When functionalized with different antibodies or medicinal compounds, the ferrofluid can be used for various purposes, e.g., to detect bacteria or for targeted drug delivery. We have considered a coflow where two fluids are separated by a vertical surface parallel to the direction of gravity. For simplicity the flow is assumed to be inviscid and incompressible. We have investigated two configurations depending on the position of the magnet relative to the channel. When the magnet is placed adjacent to the vertical wall along which the magnetic fluid is flowing, the magnetic fluid stays close to the wall unless perturbed by the shear due to a velocity difference. It results in a very stable system. In the second case, the magnet is placed close to the wall along which the non-magnetic fluid flows. The magnetic fluid gets attracted towards the magnet and tries to flow toward it when it gets resisted by the non-magnetic fluid. This configuration is inherently unstable and responds to small perturbations. The surface tension force resists the perturbation of smaller wavelengths. The relative effects of different forces are characterized by magnetic pressure number, Weber number and magnetic Weber number.

de, Anindya; Puri, Ishwar

2007-11-01

245

Microbially initiated pitting on 316L stainless steel  

Microsoft Academic Search

Pitting corrosion of 316L stainless steel ennobled in the presence of manganese-oxidizing bacteria, Leptothrix discophora, was studied in a low-concentration sodium chloride solution. Corrosion coupons were first exposed to the microorganisms in a batch reactor until ennoblement occurred, then sodium chloride was added, which initiated pitting. The pits had aspect ratios (length divided by width) and shapes closely resembling the

M Geiser; R Avci; Z Lewandowski

2002-01-01

246

Thermodynamic analysis of the brittleness of austenitic stainless steels  

Microsoft Academic Search

1.A correlation was found between changes in the thermodynamic characteristics of the formation of chromium carbide Cr23C6 and the susceptibility to embrittlement after tempering of stabilized austenitic steels. Elements raising the solubility of carbide increase the ductility and toughness after tempering.2.Chromium and manganese have opposite effects on the toughness after tempering, which agrees with their effects on the solubility of

S. D. Bogolyubskii; N. A. Sorokina; I. A. Tomilin; E. A. Ul'yanin

1974-01-01

247

Stress Corrosion Cracking of Novel Steel for Automotive Applications  

Microsoft Academic Search

In the present study, susceptibility of a high manganese TWIP steel to stress corrosion cracking (SCC) in a 3.5% NaCl solution was investigated using slow strain rate tests (SSRT), constant load (CL) tests and fractography. Strain rates employed for SSRT were in the range of 10-06 - 10-08 s-1. The specimens tested in air revealed a ductile type of failure,

Muhammed. Khalissi; R. K. Singh Raman; S. Khoddam

2011-01-01

248

Manganese and Suspended Matter in the Yaquina Estuary, Oregon.  

National Technical Information Service (NTIS)

The longitudinal distribution of total suspended matter and total, dissolved, and particulate manganese in a small coastal plain estuary is described. The distribution of manganese is a consequence of estuarine circulation; a within-estuary maximum is inv...

R. J. Callaway D. T. Specht G. R. Ditsworth

1988-01-01

249

Determination of Plutonium-Beryllium Source Strength by Manganese Activation.  

National Technical Information Service (NTIS)

In this study the manganese-sulfate-bath technique was used to determine the total neutron output of a Plutonium-Beryllium neutron source. Activation trials were conducted using 4 different concentrations of manganese sulfate and 3 different size containe...

P. F. Whitworth

1988-01-01

250

Hardness survey of cold-worked and heat-treated JBK-75 stainless steel alloy  

Microsoft Academic Search

The alloy JBK-75, an age-hardenable austenitic stainless steel, is similar to commercial A-286, but has certain chemistry modifications to improve weldability and hydrogen compatibility. The principal changes are an increase in nickel and a decrease in manganese with lower limits on carbon, phosphorus, sulfur, silicon, and boron. In this study, the effects of solutionizing time and temperature, quench rate, cold

R. J. Jackson; R. L. Lucas

1977-01-01

251

Manganese carbonyl fluorides: are they viable molecules?  

PubMed

The mononuclear Mn(CO)(5)X and binuclear Mn(2)(CO)(8)(?-X)(2) manganese carbonyl halides have long been known for the halogens Cl, Br, and I. However, the corresponding manganese carbonyl fluorides (X = F) remain unknown. The structures and thermochemistry of such manganese carbonyl fluorides and their decarbonylation products have now been investigated using density functional theory. In all cases singlet structures were found to have lower energies than the corresponding triplet structures. The expected octahedral structure is predicted for Mn(CO)(5)F. Decarbonylation of Mn(CO)(5)F is predicted to give trigonal bipyramidal Mn(CO)(4)F with equatorial fluorine. Further, decarbonylation gives tetrahedral Mn(CO)(3)F. All of the binuclear Mn(2)(CO)(n)F(2) structures (n = 8, 7, 6) are predicted to have a central Mn(2)F(2) unit with two bridging F atoms, a non-bonding Mn···Mn distance of ~3.1 Å, and exclusively terminal CO groups. The thermochemistry of these manganese carbonyl fluorides indicates that they are viable species. This suggests that the failure to date to synthesize the simple manganese carbonyl fluorides arises from a lack of a suitable synthetic method rather than from the instability of the desired products. PMID:22491522

Deng, Jianming; Li, Qian-shu; Xie, Yaoming; King, R Bruce

2012-04-11

252

Manganese neurotoxicity: an update of pathophysiologic mechanisms.  

PubMed

The central nervous system, and the basal ganglia in particular, is an important target in manganese neurotoxicity, a disorder producing neurological symptoms similar to that of Parkinson's disease. Increasing evidence suggests that astrocytes are a site of early dysfunction and damage; chronic exposure to manganese leads to selective dopaminergic dysfunction, neuronal loss, and gliosis in basal ganglia structures together with characteristic astrocytic changes known as Alzheimer type II astrocytosis. Astrocytes possess a high affinity, high capacity, specific transport system for manganese facilitating its uptake, and sequestration in mitochondria, leading to a disruption of oxidative phosphorylation. In addition, manganese causes a number of other functional changes in astrocytes including an impairment of glutamate transport, alterations of the glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase, production of nitric oxide, and increased densities of binding sites for the "peripheral-type" benzodiazepine receptor (a class of receptor predominantly localized to mitochondria of astrocytes and involved in oxidative metabolism, mitochondrial proliferation, and neurosteroid synthesis). Such effects can lead to compromised energy metabolism, resulting in altered cellular morphology, production of reactive oxygen species, and increased extracellular glutamate concentration. These consequences may result in impaired astrocytic-neuronal interactions and play a major role in the pathophysiology of manganese neurotoxicity. PMID:12602514

Normandin, Louise; Hazell, Alan S

2002-12-01

253

Transport and Deposition of Metals in Sodium-Stainless Steel Systems, (VI) Diffusion of Deposited Radioisotopes into Stainless Steel  

Microsoft Academic Search

The diffusion of radioactive manganese, zinc and cesium into stainless steel tubes exposed during 700~1,500 hr to liquid sodium containing the radioisotopes was studied by measuring the residual radioactivity on samples with their surface layers successively removed by electropolishing.Plots of the logarithm of the residual radioactivity in the tube wall drawn against the square of the thickness polished off from

Norihiko SAGAWA; Hajime IBA; Megumu URATA; Yoshihiro OZAWA

1976-01-01

254

Preparation of the electrochemically formed spinel-lithium manganese oxides  

Microsoft Academic Search

Electrochemically formed spinel-lithium manganese oxides were synthesized from manganese hydroxides prepared by a cathodic electrochemical precipitation from various concentrations of manganese nitrate solutions. Two types of manganese hydroxides were formed from diluted and concentrated Mn(NO3)2 aqueous solutions. Uniform and equi-sized disk shaped Mn(OH)2 crystals of 0.2–5?m in diameter were obtained on a Pt substrate after the electrochemical precipitation from lower

Katsumi Katakura; Kohei Wada; Yoshiyuki Kajiki; Akiko Yamamoto; Zempachi Ogumi

2009-01-01

255

Environmental effects and exposures to manganese from use of methylcyclopentadienyl manganese tricarbonyl (MMT) in gasoline.  

PubMed

Methylcyclopentadienyl Manganese Tricarbonyl (MMT) has been used since the 1970s in the U.S. as a gasoline octane enhancer Extensive testing of the effects of MMT on regulated gaseous emissions carried out on a wide variety of automobiles showed that use of MMT resulted in significantly lower NOx emissions Tests showed that less than 15% of the manganese from MMT combustion was emitted from the tailpipe, mostly in the PM2.5 fraction as manganese phosphate, with some manganese sulfate and a very small amount of manganese oxide. MMT has been used in Canada in virtually all unleaded gasoline for about 20 years. A probability-based study involving over 900 personal exposure samples in Toronto confirmed exposures to airborne PM2.5 Mn in the general population are quite low (.008 microgram/m3-median). Ambient levels of airborne manganese in Toronto are about the same as those in areas where MMT is not used. Exposures to manganese among the general population in Toronto are well within safe limits determined by the U.S. EPA and other standard setting bodies around the world. PMID:10385878

Lynam, D R; Roos, J W; Pfeifer, G D; Fort, B F; Pullin, T G

256

Altered transition metal homeostasis in mice following manganese injections for manganese-enhanced magnetic resonance imaging.  

PubMed

In manganese-enhanced magnetic resonance imaging (MEMRI), the paramagnetic divalent ion of manganese (Mn(2+)) is injected into animals to generate tissue contrast, typically at much higher exposures than have been previously used in studies of Mn toxicity. Here we investigate the effect of these injections on the homeostasis of the transition metals iron and copper in mice to see if there are disruptions which should be considered in MEMRI studies. Manganese shares transport proteins with other transition metals including iron and copper, so it is possible that changes in manganese levels in tissue following injections of the metal may affect other metal levels too. This in turn may affect MRI contrast or the investigation of disease processes in the animal models being imaged. In this study, we measured manganese, iron, and copper concentrations in the blood, kidney, liver and in brain regions in mice treated with four injections of 30 mg/kg MnCl(2) 4H(2)O (dry chemical weight/body weight)-a common dose used in MEMRI. In addition to the expected increases in manganese in tissues, we noted a statistically significant reduction in copper in the kidney and liver. Also, we noted a statistically significant decrease in concentration of iron in the thalamus of the brain. These findings suggest that the high doses of manganese injected in MEMRI studies can disrupt the homeostasis of other transition metals in mice. PMID:23334711

Moldovan, Nataliya; Al-Ebraheem, Alia; Miksys, Nelson A; Farquharson, Michael J; Bock, Nicholas A

2013-01-19

257

Method of making high strength, tough alloy steel  

DOEpatents

A high strength, tough alloy steel, particularly suitable for the mining industry, is formed by heating the steel to a temperature in the austenite range (1000.degree.-1100.degree. C.) to form a homogeneous austenite phase and then cooling the steel to form a microstructure of uniformly dispersed dislocated martensite separated by continuous thin boundary films of stabilized retained austenite. The steel includes 0.2-0.35 weight % carbon, at least 1% and preferably 3-4.5% chromium, and at least one other subsitutional alloying element, preferably manganese or nickel. The austenite film is stable to subsequent heat treatment as by tempering (below 300.degree. C.) and reforms to a stable film after austenite grain refinement.

Thomas, Gareth (Berkeley, CA); Rao, Bangaru V. N. (Albany, CA)

1979-01-01

258

Manganese (II) induces chemical hypoxia by inhibiting HIF-prolyl hydroxylase: Implication in manganese-induced pulmonary inflammation  

SciTech Connect

Manganese (II), a transition metal, causes pulmonary inflammation upon environmental or occupational inhalation in excess. We investigated a potential molecular mechanism underlying manganese-induced pulmonary inflammation. Manganese (II) delayed HIF-1{alpha} protein disappearance, which occurred by inhibiting HIF-prolyl hydroxylase (HPH), the key enzyme for HIF-1{alpha} hydroxylation and subsequent von Hippel-Lindau(VHL)-dependent HIF-1{alpha} degradation. HPH inhibition by manganese (II) was neutralized significantly by elevated dose of iron. Consistent with this, the induction of cellular HIF-1{alpha} protein by manganese (II) was abolished by pretreatment with iron. Manganese (II) induced the HIF-1 target gene involved in pulmonary inflammation, vascular endothelial growth factor (VEGF), in lung carcinoma cell lines. The induction of VEGF was dependent on HIF-1. Manganese-induced VEGF promoted tube formation of HUVEC. Taken together, these data suggest that HIF-1 may be a potential mediator of manganese-induced pulmonary inflammation.

Han, Jeongoh [Laboratory of Biomedicinal Chemistry, College of Pharmacy, Pusan National University, Busan, 609-735 (Korea, Republic of); Lee, Jong-Suk [Laboratory of Physiology, College of Pharmacy, Yeungnam University, Gyeongsan (Korea, Republic of); Choi, Daekyu; Lee, Youna; Hong, Sungchae; Choi, Jungyun; Han, Songyi [Laboratory of Biomedicinal Chemistry, College of Pharmacy, Pusan National University, Busan, 609-735 (Korea, Republic of); Ko, Yujin; Kim, Jung-Ae [Laboratory of Physiology, College of Pharmacy, Yeungnam University, Gyeongsan (Korea, Republic of); Mi Kim, Young [Medicinal Chemistry, College of Pharmacy, Pusan National University, Busan (Korea, Republic of); Jung, Yunjin [Laboratory of Biomedicinal Chemistry, College of Pharmacy, Pusan National University, Busan, 609-735 (Korea, Republic of)], E-mail: jungy@pusan.ac.kr

2009-03-15

259

Metal desulfurization with manganese in the course of direct alloying  

NASA Astrophysics Data System (ADS)

The problems of metal desulfurization in the course of direct alloying with manganese via feeding manganese sinter and aluminum into a ladle during pouring a metal from a steelmaking vessel are considered. According to calculations and experimental data, the degree of desulfurization is 30-35 and 60% at manganese contents of 0.5 and more than 1%, respectively.

Nakonechnyi, A. Ya.; Urtsev, V. N.; Sinyakov, R. V.; Khabibulin, D. M.; Kudrin, V. A.; Shmakov, A. V.

2010-12-01

260

Manganese oxide reduction as a form of anaerobic respiration  

Microsoft Academic Search

Some instances of bacterial manganese oxide reduction observed in nature and under laboratory conditions are a form of respiration. Anaerobiosis is not a necessary condition for its occurrence, although anaerobic reduction of manganese oxide which is inhibited by air has been reported. It is the kind of manganese reducing microorganism involved which determines whether anaerobic conditions are required. In at

Henry L. Ehrlich

1987-01-01

261

Investigation of manganese-doped iron ammonia synthesis catalysts  

Microsoft Academic Search

The iron catalysts for ammonia synthesis doped with manganese in amounts up to 3wt.% has been investigated. The addition of manganese oxide did not influence the distribution of other promoters in the catalyst precursors, manganese oxide itself was entirely incorporated into phases of iron oxides, its concentration in the wustite phase was about twice that in the magnetite phase.At concentrations

Micha? J. Figurski; Walerian Arabczyk; Zofia Lendzion-Bielu?; Stanis?aw Lenart

2004-01-01

262

Microorganisms and manganese cycling in a seasonally stratified freshwater dam  

Microsoft Academic Search

This work describes investigations into the role that biotic and abiotic mechanisms play in the manganese redox cycle in a freshwater dam over a twelve month period. Enzymatic control of manganese oxidation was taking place with a temperature optimum of approx. 30°C. Manganese oxidation was only significant above about 19°C. The temperature and season play vital roles in determining the

David Johnson; Barry Chiswell; Kelvin O'halloran

1995-01-01

263

The search for magnetic fields in mercury-manganese stars  

NASA Astrophysics Data System (ADS)

Context. A subclass of the upper main-sequence chemically peculiar stars, mercury-manganese (HgMn) stars were traditionally considered to be non-magnetic, showing no evidence of variability in their spectral line profiles. However, discoveries of chemical inhomogeneities on their surfaces imply that this assumption should be investigated. In particular, spectroscopic time-series of AR Aur, ? And, and five other HgMn stars indicate the presence of chemical spots. At the same time, no signatures of global magnetic fields have been detected. Aims: We attempt to understand the physical mechanism that causes the formation of chemical spots in HgMn stars and gain insight into the potential magnetic field properties at their surfaces; we performed a highly sensitive search for magnetic fields for a large set of HgMn stars. Methods: With the aid of a new polarimeter attached to the HARPS spectrometer at the ESO 3.6 m-telescope, we obtained high-quality circular polarization spectra of 41 single and double HgMn stars. Using a multi-line analysis technique on each star, we co-added information from hundreds of spectral lines to ensure significantly greater sensitivity to the presence of magnetic fields, including very weak fields. Results: For the 47 individual objects studied, including six components of SB2 systems, we do not detect any magnetic fields at greater than the 3? level. The lack of detection in the circular polarization profiles indicates that if strong fields are present on these stars, they must have complex surface topologies. For simple global fields, our detection limits imply upper limits to the fields present of 2-10 Gauss in the best cases. Conclusions: We conclude that HgMn stars lack large-scale magnetic fields, which is typical of spotted magnetic Ap stars, of sufficient strength to form and sustain the chemical spots observed on HgMn stars. Our study confirms that in addition to magnetically altered atomic diffusion, there exists another differentiation mechanism operating in the atmospheres of late-B main sequence stars that can produce compositional inhomogeneities on their surfaces. Based on observations collected at the European Southern Observatory, Chile (ESO programs 083.D-1000, 084.D-0338, 085.D-0296).Figure 5 is only available in electronic form at http://www.aanda.org

Makaganiuk, V.; Kochukhov, O.; Piskunov, N.; Jeffers, S. V.; Johns-Krull, C. M.; Keller, C. U.; Rodenhuis, M.; Snik, F.; Stempels, H. C.; Valenti, J. A.

2011-01-01

264

Metal Uptake by Manganese Superoxide Dismutase  

PubMed Central

Manganese superoxide dismutase is an important antioxidant defense metalloenzyme that protects cells from damage by the toxic oxygen metabolite, superoxide free radical, formed as an unavoidable by-product of aerobic metabolism. Many years of research have gone into understanding how the metal cofactor interacts with small molecules in its catalytic role. In contrast, very little is presently known about how the protein acquires its metal cofactor, an important step in the maturation of the protein and one that is absolutely required for its biological function. Recent work is beginning to provide insight into the mechanisms of metal delivery to manganese superoxide dismutase in vivo and in vitro.

Whittaker, James W.

2009-01-01

265

Manganese silicide nanowires on Si(001).  

PubMed

A method for promoting the growth of manganese silicide nanowires on Si(001) at 450 °C is described. The anisotropic surface stress generated by bismuth nanolines blocks the formation of embedded structures and stabilizes the nucleation of manganese silicide islands which grow in a preferred direction, forming nanowires with a band gap of approximately 0.6 eV, matching the reported band gap of MnSi(1.7). This method may also provide a means to form silicide nanowires of other metals where they do not otherwise form. PMID:21474879

Liu, H J; Owen, J H G; Miki, K; Renner, Ch

2011-04-08

266

Magnesium/manganese dioxide electrochemical cell  

SciTech Connect

This patent describes an improvement in a magnesium/manganese dioxide electrochemical cell that has been stored following partial usage and including an alloy of magnesium as the anode, a moist cathode mix of carbon black, manganese dioxide, magnesium hydroxide, barium chromate and lithium chromate as the cathode, and 3.5 to 4.0 normal magnesium perchlorate as the electrolyte. The improvement involves increasing the moisture content of the cathode mix from 34 to 38 percent at the time of making the cell to reduce the self discharge and increase the operating capacity after the cell has been stored following partial usage.

Jarvis, L.P.; Brundage, M.T.; Atwater, T.B.

1989-09-26

267

Mechanical properties and machinability of a high-strength, medium-carbon, microalloyed steel  

SciTech Connect

The development of a high-strength (tensile strength beyond 900 N/mm/sup 2/), medium-carbon, vanadium microalloyed steel for hot-forged automotive components reviewed in the paper. The influence of different alloying elements was investigated. The most effective elements to increase the strength were chromium and manganese. In TEM investigation, it was found that, in comparison with the lower-strength melt chromium plus manganese alloyed steel showed a high density of small V(C,N) precipitates. Most mechanical properties of the microalloyed and quenched and tempered steel were essentially equal. Exceptions were the lower impact strength and higher fatigue strength of the microalloyed steel. Possibilities to improve the impact strength of the microalloyed steel are being considered. Machinability was tested in different operations. Generally, the machinability was comparable with quenched and tempered steels; however, a different behavior was found in deep-hole drilling. The use of calcium treatment to improve machinability is discussed. The high-strength microalloyed grade developed can substitute for alloyed quenched and tempered steels in most components. When weight saving is desired, the possibility of substituting the high-strength grade for lower-strength microalloyed steels is considered.

Ollilainen, V.; Hurmola, H.; Pontinen, H.

1984-03-01

268

Giant magnetoresistance in non-magnetic phosphoric acid doped polyaniline silicon nanocomposites with higher magnetic field sensing sensitivity.  

PubMed

Phosphoric acid doped conductive polyaniline (PANI) polymer nanocomposites (PNCs) reinforced with silicon nanopowders have been successfully synthesized using a facile surface initiated polymerization (SIP) method. The chemical structures of the nanocomposites are characterized using Fourier transform infrared (FT-IR) spectroscopy. The enhanced thermal stability of the silicon-PANI PNCs compared with pure PANI is obtained using thermogravimetric analysis (TGA). The obtained optical band gap of the PNCs using Ultraviolet-visible diffuse reflectance spectroscopy (UV-vis DRS) decreases with increasing silicon loading. The dielectric properties of the PNCs are strongly related to the silicon loading level. Temperature dependent resistivity analysis reveals a quasi 3-D variable range hopping (VRH) electrical conduction mechanism for the synthesized PNCs. Room temperature giant magnetoresistance (GMR) is observed in the synthesized non-magnetic nanocomposites and analyzed using the wave-function shrinkage model. PMID:23698645

Gu, Hongbo; Guo, Jiang; Wei, Huige; Huang, Yudong; Zhao, Cunyu; Li, Ying; Wu, Qingliu; Haldolaarachchige, Neel; Young, David P; Wei, Suying; Guo, Zhanhu

2013-05-22

269

Manganese regulation of manganese peroxidase expression and lignin degradation by the white rot fungus Dichomitus squalens  

SciTech Connect

Extracellular manganese peroxidase and laccase activities were detected in cultures of Dichomitus squalens (Polyporus anceps) under conditions favoring lignin degradation. In contrast, neither extracellular lignin peroxidase nor aryl alcohol oxidase activity was detected in cultures grown under a wide variety of conditions. The mineralization of {sup 14}C-ring-, -side chain-, and -methoxy-labeled synthetic guaiacyl lignins by D. squalens and the expression of extracellular manganese peroxidase were dependent on the presence of Mn(II), suggesting that manganese peroxidase is an important component of this organism's lignin degradation system. The expression of laccase activity was independent of manganese. In contrast to previous findings with Phanero-chaete chrysosporium, lignin degradation by D. squalens proceeded in the cultures containing excess carbon and nitrogen.

Perie, F.; Gold, M.H. (Oregon Graduate Institute of Science and Technology, Beaverton (USA))

1991-08-01

270

Anodically deposited manganese oxide and manganese–tungsten oxide electrodes for oxygen evolution from seawater  

Microsoft Academic Search

The oxygen evolution efficiency in seawater electrolysis has been examined for manganese oxide and manganese–tungsten oxide electrodes anodically deposited on iridium oxide-coated titanium substrates as a function of pH of the deposition electrolytes and tungsten content in the oxides. The oxygen evolution efficiency in 0.5M NaCl solution at 30°C on the MnO2 electrodes increases with a decrease in pH of

K. Izumiya; E. Akiyama; H. Habazaki; N. Kumagai; A. Kawashima; K. Hashimoto

1998-01-01

271

Analysis of manganese particulates from automotive decomposition of methylcyclopentadienyl manganese tricarbonyl  

Microsoft Academic Search

Particulates have been collected and analyzed from automotive vehicles operating on fuel containing the organometallic antiknock additive methylcyclopentadienyl manganese tricarbonyl. Electron spectroscopy for chemical analysis and L-edge X-ray absorption spectroscopy were used to study and identify the manganese species present in these emitted particulates. Results show that respirable size particulates with a mass median aerodynamic diameter of 2.5 ?m or

C. Colmenares; Steven Deutsch; Cheryl Evans; A. J. Nelson; Louis J. Terminello; John G. Reynolds; Joseph W. Roos; Isaac L. Smith

1999-01-01

272

Old age and gender influence the pharmacokinetics of inhaled manganese sulfate and manganese phosphate in rats  

Microsoft Academic Search

In this study, we examined whether gender or age influences the pharmacokinetics of manganese sulfate (MnSO4) or manganese phosphate (as the mineral form hureaulite). Young male and female rats and aged male rats (16 months old) were exposed 6 h day?1 for 5 days week?1 to air, MnSO4 (at 0.01, 0.1, or 0.5 mg Mn m?3), or hureaulite (0.1 mg

David C Dorman; Brian E McManus; Marianne W Marshall; R. Arden James; Melanie F Struve

2004-01-01

273

Thermodynamics of carbon and oxygen solutions in manganese melts  

NASA Astrophysics Data System (ADS)

The thermodynamics of carbon and oxygen solutions in manganese melts is studied. An equation for the temperature dependence of the activity coefficient of carbon in liquid manganese is obtained (?{C(Mn)/0}= -1.5966 + (1.0735 × 10-3) T). The temperature dependence of the Gibbs energy of the reaction of carbon dissolved in liquid manganese with the oxygen of manganese oxide is shown to be described by the equation ? G {T/0}= 375264 - 184.66 T(J/mol). This reaction can noticeably be developed depending on the carbon content at temperatures of 1700 1800°C. The deoxidation ability of carbon in manganese melts is shown to be much lower than that in iron and nickel melts due to the higher affinity of manganese to both oxygen and carbon. Although the deoxidation ability of carbon in manganese melts increases with temperature, the process develops at rather high carbon contents in all cases.

Dashevskii, V. Ya.

2007-12-01

274

Electrochemical lithium intercalation in nanosized manganese oxides  

NASA Astrophysics Data System (ADS)

X-ray amorphous manganese oxides were prepared by reduction of sodium permanganate by lithium iodide in aqueous medium (MnOx-I) and by decomposition of manganese carbonate at moderate temperature (MnOx-C). TEM showed that these materials are not amorphous, but nanostructured, with a prominent spinel substructure in MnOx-C. These materials intercalate lithium with capacities up to 200 mAh/g at first cycle (potential window 1.8 4.3 V) and 175 mAh/g at 100th cycle. Best performances for MnOx-C are obtained with cobalt doping. Potential electrochemical spectroscopy shows that the initial discharge induces a 2-phase transformation in MnOx-C phases, but not in MnOx-I ones. EXAFS and XANES confirm the participation of manganese in the redox process, with variations in local structure much smaller than in known long-range crystallized manganese oxides. X-ray absorption spectroscopy also shows that cobalt in MnOx-C is divalent and does not participate in the electrochemical reaction.

Strobel, P.; Darie, C.; Thiéry, F.; Ibarra-Palos, A.; Bacia, M.; Proux, O.; Soupart, J. B.

2006-05-01

275

Manganese Nodule Resource Data, Sea Scope Expedition.  

National Technical Information Service (NTIS)

New information on possible resource value of sea floor manganese nodule deposits in the eastern North Pacific has been obtained by a study of records and collections of the 1972 Sea Scope Expedition. Nodule abundance (percent of sea floor covered) varies...

R. H. Fewkes W. D. McFarland R. K. Sorem

1981-01-01

276

Manganese Decreases Glutamate Uptake in Cultured Astrocytes  

Microsoft Academic Search

Recent data have shown an accumulation of manganese in the basal ganglia in patients with chronic hepatic encephalopathy (HE). Astrocytes and ammonia are critically involved in the pathogenesis of HE, and we have recently demonstrated that ammonia decreases glutamate uptake in cultured astrocytes. Since failure by astrocytes to take up glutamate may represent an important pathogenetic mechanism in HE, we,

Alan S. Hazell; Michael D. Norenberg

1997-01-01

277

Structural stability of lithium manganese oxides  

Microsoft Academic Search

We have studied stability of lithium-manganese oxides using density functional theory in the local density and generalized gradient approximation (GGA). In particular, the effect of spin-polarization and magnetic ordering on the relative stability of various structures is investigated. At all lithium compositions the effect of spin polarization is large, although it does not affect different structures to the same extent.

S. K. Mishra; G. Ceder

1999-01-01

278

Manganese ore deposits and plate tectonics  

Microsoft Academic Search

IT is now generally accepted that the oceanic crust and overlying pelagic sediments are enriched in several metals, including copper and manganese1-3. The theory of plate tectonics has demonstrated that the oceanic lithosphere is likely to be remobilised or emplaced along convergent continental margins through magmatic or tectonic activity. The plate tectonic model has been used to explain the metallogenesis

Michael Thonis; ROGER G. BURNS

1975-01-01

279

Particulate Manganese in the Black Sea.  

National Technical Information Service (NTIS)

Manganese nodules are thought to form by the oxidation of Mn(II) to Mn(IV) at an active site, and the trace metal enrichments have been related to the surface chemistry of this oxidized product. Recent data from the Black Sea have shown the existence of a...

P. G. Brewer

1972-01-01

280

Cation distribution, structure and magnetic properties of lithium manganese iron oxide spinel solid solutions  

SciTech Connect

Single phase cubic spinel compounds Li {sub x}Mn{sub 1+x}Fe{sub 2-2x}O{sub 4} (x = 0, ..., 1) were obtained by thermal decomposition of freeze-dried formate solutions of appropriate composition. The samples were characterized by X-ray powder diffraction and Rietveld refinement, XANES, {sup 57}Fe Moessbauer spectroscopy and magnetization measurements. The combination of these methods provides useful conclusions concerning the structure, cation distribution and properties of the spinel solid solutions. The Li {sub x}Mn{sub 1+x}Fe{sub 2-2x}O{sub 4} samples contain Mn(II) and Mn(III) or Mn(III) and Mn(IV) for x < 0.5 or x > 0.5, respectively. With the increase of x the portion of Li ions occupying tetrahedral sites increases and becomes 100% at about x = 4/7. In spite of the preferred occupation of octahedral sites by manganese(III), the experimental results can only be explained by a partial occupation also of tetrahedral sites by Mn(III). An increase of M {sub S} with the increase of x (expected for a preferred substitution of magnetic ions in tetrahedral sites by non-magnetic Li ions) is not observed. It should be prevented by the decreasing cooperative coupling effects due to the reduction of the iron content.

Wende, C. [Institute of Inorganic Chemistry, Dresden University of Technology, 01062 Dresden (Germany); Olimov, Kh. [Institute of Physics, University of Bonn, 53115 Bonn (Germany); Modrow, H. [Institute of Physics, University of Bonn, 53115 Bonn (Germany); Wagner, F.E. [Physics Department, Technical University of Munich, 85748 Garching (Germany); Langbein, H. [Institute of Inorganic Chemistry, Dresden University of Technology, 01062 Dresden (Germany)]. E-mail: Hubert.Langbein@chemie.tu-dresden.de

2006-08-10

281

On the Optimization of Compressibility and Hardenability of Sinter-Hardenable PM Steels  

NASA Astrophysics Data System (ADS)

Sinter-hardenable steel powders eliminate the extra steps normally required for heat treating since they allow for direct quenching of components at the end of the sintering cycle with a forced convection cooling unit. The current article presents the results of the effect of the alloying method on the optimization of compressibility and sinter-hardenability of sinter-hardenable PM steels. Water-atomized steel powders were produced. Two successive designs of experiments were used to optimize the chemical composition with prealloyed (nickel, chromium, molybdenum, and manganese) and admixed elements (nickel, chromium, manganese, and copper). Static mechanical properties were also characterized. Results show that among all of the combinations of chemical elements and within the range of concentrations studied, the optimum sinter-hardenable powder had the following prealloyed chemistry: 1.5 wt pct Ni, 1 to 1.25 wt pct Mo, and 0.40 to 0.55 wt pct Cr.

Giguère, Nicolas; Blais, Carl

2013-10-01

282

Effect of chemical composition on the heat resistance of steel Kh25N16G7AR  

Microsoft Academic Search

By statistical treatment of data on commercial heats of steel Kh25N16G7AR by the method of multiple correlations we determined the effect of the chemical composition on the heat resistance at 850°C. An increase of the chromium and silicon concentrations, and also a reduction of the manganese, nickel, and phosphorus concentrations, increases the heat resistance of the steel. Within the nominal

V. M. Smirnov; A. T. Perevyazko; V. L. Fedorov

1972-01-01

283

Microstructural aspects of the fracture toughness and fatigue resistance of high-strength low-carbon steels  

Microsoft Academic Search

High-strength low-carbon steels alloyed with manganese, nickel, molybdenum, and vanadium are characterized by a satisfactory combination of strength and cold resistance in large-section components, and also by satisfactory weldability ensured by a low (0+06-0.1 wt. %) carbon content [1-4]. One of the main disadvantages of this group of steels is the high price, which can be reduced by producing the

B. M. Bronfin; I. Yu. Pyshmintsev

1992-01-01

284

Impact of economic sanctions against South Africa on the strategic mineral position of the US: the cases of antimony and manganese  

SciTech Connect

In 1980 the US was dependent upon imports to meet over 50% of domestic industrial requirements for 25 non-fuel minerals, including antimony and manganese. This dependency places the US in a vulnerable position with respect to potential supply disruptions. For antimony and manganese, this vulnerability results because the latter is indispensable in the production of virtually all iron and steel while the former has numerous military applications. The Republic of South Africa is an important source of both commodities for the US. The denial of South African minerals to the international market as a result of the imposition of comprehensive sanctions would pose serious economic and strategic problems to this country and its allies. The US strategic mineral position for antimony and manganese and the role that South Africa plays in the international production and trade of those two materials are examined. The efficacy of the steps this country could take to compensate for lost South African supplies of antimony and manganese are assessed, including expanding production from domestic sources of supply, utilizing substitutes, recycling industrial scrap, material conservation, and the implementation of export controls. The US is in a favorable position to adjust to both a short- and long-term antimony supply disruption; however there may be short-term supply problems with respect to manganese ore and ferromanganese.

Davenport, J.C.

1982-01-01

285

Manganese modulates pro-inflammatory gene expression in activated glia.  

PubMed

Redox-active metals are of paramount importance for biological functions. Their impact and cellular activities participate in the physiological and pathophysiological processes of the central nervous system (CNS), including inflammatory responses. Manganese is an essential trace element and it is required for normal biological activities and ubiquitous enzymatic reactions. However, excessive chronic exposure to manganese results in neurobehavioral deficits. Recent evidence suggests that manganese neurotoxicity involves activation of microglia or astrocytes, representative CNS immune cells. In this study, we assessed the molecular basis of the effects of manganese on the modulation of pro-inflammatory cytokines and nitric oxide (NO) production in primary rat cortical glial cells. Cultured glial cells consisted of 85% of astrocytes and 15% of microglia. Within the assayed concentrations, manganese was unable to induce tumor necrosis factor alpha (TNF-alpha) and inducible nitric oxide synthase (iNOS) expression, whereas it potentiated iNOS and TNF-alpha gene expression by lipopolysaccharide/interferon-gamma-activated glial cells. The enhancement was accompanied by elevation of free manganese, generation of oxidative stress, activation of mitogen-activated protein kinases, and increased NF-kappaB and AP-1 binding activities. The potentiated degradation of inhibitory molecule IkappaB-alpha was one of underlying mechanisms for the increased activation of NF-kappaB by manganese. However, manganese decreased iNOS enzymatic activity possibly through the depletion of cofactor since exogenous tetrahydrobiopterin reversed manganese's action. These data indicate that manganese could modulate glial inflammation through variable strategies. PMID:16488514

Chen, Chun-Jung; Ou, Yen-Chuan; Lin, Shih-Yi; Liao, Su-Lan; Chen, Shih-Yun; Chen, Jian-Hong

2006-02-20

286

A simple route to synthesize manganese germanate nanorods  

SciTech Connect

Manganese germanate nanorods have been synthesized by a simple route using germanium dioxide and manganese acetate as the source materials. X-ray diffraction observation shows that the nanorods are composed of orthorhombic and monoclinic manganese germanate phases. Scanning electron microscopy and transmission electron microscopy observations display that the manganese germanate nanorods have flat tips with the length of longer than 10 micrometers and diameter of 60-350 nm, respectively. The role of the growth conditions on the formation of the manganese germanate nanorods shows that the proper selection and combination of the growth conditions are the key factor for controlling the formation of the manganese germanate nanorods. The photoluminescence spectrum of the manganese germanate nanorods exhibits four fluorescence emission peaks centered at 422 nm, 472 nm, 487 nm and 530 nm showing the application potential for the optical devices. - Research Highlights: {yields} Manganese germanate nanorods have been synthesized by simple hydrothermal process. {yields} The formation of manganese germanate nanorods can be controlled by growth conditions. {yields} Manganese germanate nanorods exhibit good PL emission ability for optical device.

Pei, L.Z., E-mail: lzpei1977@163.com; Yang, Y.; Yuan, C.Z.; Duan Taike; Zhang Qianfeng

2011-06-15

287

Influence on superconductivity in the parity mixing superconductor Li2T3B(T:Pt,Pd) by non-magnetic impurity and defect doping  

NASA Astrophysics Data System (ADS)

Superconductors with noncentrosymmetric crystal structures such as Li2T3B(T:Pd,Pt) have been the focus of in-depth research with their parity mixing nature. In this study, we focused our research on non-magnetic impurity effect in Li2T3B(T:Pd,Pt). The nature of the pair breaking by non-magnetic impurity in the parity mixing superconducting state is still unclear. We prepared different quality samples of Li2Pd3B and Li2Pt3B by changing conditions in synthesizing, and sample qualities were estimated by residual resistivity. Spin singlet dominant superconductor Li2Pd3B exhibits the weak Tc suppression attributed by non-magnetic impurity and defects, while Hc2 (0) value increased. This behavior is similar in ordinary s-wave superconductor. On the other hand, for the spin triplet dominant superconductor Li2Pt3B, it was suggested that the Cooper pair was broken and superconducting gap was decreased by non-magnetic impurities and defects. Li2Pt3B is similar to unconventional superconducting state.

Bao, G.; Inada, Y.; Eguchi, G.; Maeno, Y.; Ichioka, M.; Zheng, G.-q.

2013-11-01

288

Sulfide stress-cracking resistance of nitrogen-strengthened stainless steels  

SciTech Connect

A description is given of sulfide stress-cracking tests performed on a number of these alloys. Most were found to be somewhat susceptible to cracking, depending on the stress level. It was determined that this was due to their high manganese content. The mechanism responsible for cracking was not firmly established. One commercial nitrogen-strengthened stainless steel, XM19, was highly resistant to sulfide stress cracking despite a manganese content of 5%. This difference is attributed to the superior corrosion resistance of the alloy. 6 refs.

Gaugh, R.R.

1982-03-01

289

Manganese oxide cathodes for rechargeable batteries  

NASA Astrophysics Data System (ADS)

Manganese oxides are considered as promising cathodes for rechargeable batteries due to their low cost and low toxicity as well as the abundant natural resources. In this dissertation, manganese oxides have been investigated as cathodes for both rechargeable lithium and alkaline batteries. Nanostructured lithium manganese oxides designed for rechargeable lithium cells have been synthesized by reducing lithium permanganate with methanol or hydrogen in various solvents followed by firing at moderate temperatures. The samples have been characterized by wet-chemical analyses, thermal methods, spectroscopic methods, and electron microscopy. It has been found that chemical residues in the oxides such as carboxylates and hydroxyl groups, which could be controlled by varying the reaction medium, reducing agents, and additives, make a significant influence on the electrochemical properties. The Li/Mn ratio in the material has also been found to be a critical factor in determining the rechargeability of the cathodes. The optimized samples exhibit a high capacity of close to 300 mAh/g with good cyclability and charge efficiency. The high capacity with a lower discharge voltage may make these nanostructured oxides particularly attractive for lithium polymer batteries. The research on the manganese oxide cathodes for alkaline batteries is focused on an analysis of the reaction products generated during the charge/discharge processes or by some designed chemical reactions mimicking the electrochemical processes. The factors influencing the formation of Mn3O4 in the two-electron redox process of delta-MnO2 have been studied with linear sweep voltammetry combined with X-ray diffraction. The presence of bismuth, the discharge rate, and the microstructure of the electrodes are found to affect the formation of Mn3O4, which is known to be electrochemically inactive. A faster voltage sweep and a more intimate mixing of the manganese oxide and carbon in the cathode are found to suppress the formation of Mn3O4. Bismuth has also been found to be beneficial in the one-electron process of gamma-MnO 2 when incorporated into the cathode. The results of a series of chemical reactions reveal that bismuth is blocking some reaction paths leading to the unwanted birnessite or Mn3O4. Barium is also found to play a similar role, but it is less effective than bismuth for the same amount of additive. Optimization of the additives has the potential to make the rechargeable alkaline cells based on manganese oxides to successfully compete with other rechargeable systems due to their low cost, environmental friendliness, and excellent safety features.

Im, Dongmin

290

Interaction of dietary calcium, manganese, and manganese source (Mn oxide or Mn methionine complex) on chick performance and manganese utilization  

Microsoft Academic Search

Two trials were conducted to determine the utilization of manganese (Mn) as influenced by the level and source of Mn and the\\u000a level of dietary calcium (Ca) in broiler chickens. Trial One was a 2 × 2 × 3 factorial arrangement of two Mn sources (Mn methionine\\u000a or manganous oxide), two levels of dietary Ca (1.8 or 1.0), and three

Sheila E. Scheideler

1991-01-01

291

Glutamate\\/Aspartate Transporter (GLAST), Taurine Transporter and Metallothionein mRNA Levels are Differentially Altered in Astrocytes Exposed to Manganese Chloride, Manganese Phosphate or Manganese Sulfate  

Microsoft Academic Search

Manganese (Mn)-induced neurotoxicity can occur due to environmental exposure (air pollution, soil, water) and\\/or metabolic aberrations (decreased biliary excretion). High brain manganese levels lead to oxidative stress, as well as alterations in neurotransmitter metabolism with concurrent neurobehavioral deficits. Based on the few existing studies that have examined brain regional Mn concentration, it is likely that in pathological conditions, Mn concentration

Keith M. Erikson; Robert L. Suber; Michael Aschner

2002-01-01

292

Structure and Properties of Manganese-Substituted Bismuth Titanates  

NASA Astrophysics Data System (ADS)

Partial substitution of manganese for titanium in bismuth titanate is a potential method to introduce ferromagnetic properties to ferroelectric bismuth titanate. We have established that manganese-substituted bismuth titanate forms only at low manganese contents. As the manganese content is increased, secondary phases form. A combination of neutron and synchrotron X-ray powder diffraction has been used to determine the structure of manganese-substituted bismuth titanates with chemical composition Bi4MnxTi3_xO12 (0 <= x <=1 at 0.05 steps). Measurements between 4 K and 1073 K have been used to examine the phase transitions that they undergo. It was found the substitution of manganese into bismuth titanate increases the phase transition temperature to tetragonal by about 100 °C. Neutron diffraction and bulk magnetic susceptibility measurements demonstrate the absence of long-range magnetic cation ordering in selected examples.

Ting, J.; Kennedy, B. J.

2010-11-01

293

Kinetics of decomposition of manganese slimes by sulfur dioxide  

SciTech Connect

Lean manganese ores, and slimes obtained during mechanical beneficiation of Chiatura manganese ores, have been treated by the sulfite process, by saturation of suspensions with sulfur dioxide. The kinetics of saturation of the suspensions with sulfur dioxide, and transfer of manganese into solution was studied. Manganese was leached out by passing sulfur dioxide through the slime suspension. The sulfur dioxide dissolved in water to form the weakly dissociated sulfurous acid in equilibrium with its anhydrides. The leaching was conducted without access of air at room temperature. An equation for determination of the rate of sulfur dioxide adsorption by a manganese-containing slurry and for calculation of the degree of manganese extraction into solution was developed from the experimental results. The reaction order and the control regime of the processes were determined.

Dzhaparidze, P.I.; Kelbakiani, N.V.

1982-02-20

294

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

Code of Federal Regulations, 2010 CFR

... 2010-07-01 false Lithium manganese oxide (LiMn204) (generic name...Substances § 721.4587 Lithium manganese oxide (LiMn204) (generic name...identified generically as lithium manganese oxide (LiMn204)...

2010-07-01

295

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

Code of Federal Regulations, 2010 CFR

... 2009-07-01 false Lithium manganese oxide (LiMn204) (generic name...Substances § 721.4587 Lithium manganese oxide (LiMn204) (generic name...identified generically as lithium manganese oxide (LiMn204)...

2009-07-01

296

40 CFR 424.60 - Applicability; description of the electrolytic manganese products subcategory.  

Code of Federal Regulations, 2010 CFR

...Applicability; description of the electrolytic manganese products subcategory. 424.60 Section...POINT SOURCE CATEGORY Electrolytic Manganese Products Subcategory § 424.60 ...Applicability; description of the electrolytic manganese products subcategory. The...

2010-07-01

297

40 CFR 424.60 - Applicability; description of the electrolytic manganese products subcategory.  

Code of Federal Regulations, 2010 CFR

...Applicability; description of the electrolytic manganese products subcategory. 424.60 Section...POINT SOURCE CATEGORY Electrolytic Manganese Products Subcategory § 424.60 ...Applicability; description of the electrolytic manganese products subcategory. The...

2009-07-01

298

40 CFR 721.10223 - Styrenyl surface treated manganese ferrite with acrylic ester polymer (generic).  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Styrenyl surface treated manganese ferrite with acrylic ester polymer...721.10223 Styrenyl surface treated manganese ferrite with acrylic ester polymer...generically as styrenyl surface treated manganese ferrite with acrylic ester...

2013-07-01

299

40 CFR 721.10222 - Styrenyl surface treated manganese ferrite (generic).  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Styrenyl surface treated manganese ferrite (generic). 721.10222...721.10222 Styrenyl surface treated manganese ferrite (generic). (a) Chemical...generically as styrenyl surface treated manganese ferrite (PMN P-09-581) is...

2013-07-01

300

78 FR 54269 - Electrolytic Manganese Dioxide From Australia and China; Institution of Five-Year Reviews  

Federal Register 2010, 2011, 2012, 2013

...Electrolytic Manganese Dioxide From Australia and China; Institution of Five-Year...on electrolytic manganese dioxide from Australia and China would be likely to lead to...of electrolytic manganese dioxide from Australia and China (73 FR 58537-58539)....

2013-09-03

301

Cathodic current enhancement via manganese and oxygen related reactions in marine biofilms  

NASA Astrophysics Data System (ADS)

Corrosion is a threat that has economic, and environmental impacts worldwide. Many types of corrosive attack are the subject of ongoing research. One of these areas of research is microbiologically influenced corrosion, which is the enhancement and/or initiation of corrosion events caused by microorganisms. It is well known that colonies of microorganisms can enhance cathodic currents through biofilm formation. The aim of the present work was to elucidate the role of manganese in enhancing cathodic currents in the presence of biofilms. Repeated polarizations conducted in Delaware Bay waters, on biofilm coated Cr identified potentially sustainable reduction reactions. The reduction of MnO2 and the enhancement of the oxygen reduction reaction (ORR) were proven to be factors that influence cathodic current enhancement. The removal of ambient oxygen during polarizations resulted in a shutdown of cathodic current enhancement. These field data led to an exploration of the synergistic relationship between MnO2 and the ORR. Laboratory studies of the catalysis of peroxide disproportionation by MnO2 were monitored using a hanging mercury drop electrode. Experiments were run at an ambient sweater pH of 8 and pH 9, which simulated the near-surface conditions typical of cathodes immersed in seawater. Rapid reoxidation at the more basic pH was shown to allow manganese to behave as a persistent catalyst under the typical electrochemical surface conditions of a cathode. As a result a mechanism for ORR enhancement by manganese was proposed as a unique mechanism for cathodic current enhancement in biofilms. A separate field study of Delaware biofilms on stainless steel coupled to a sacrificial Al anode was carried out to identify the ORR enhancement mechanism and sustainable redox reactions at the cathode. Chemical treatments of glutaraldehyde and formaldoxime were applied to cathodes with biofilms to distinguish between enzymatic and MnO2 related ORR enhancement. The results ruled out the enzymatic catalysis of ORR and supported the catalysis by MnO2. Sustainable redox reactions at the cathode were evaluated by monitoring the cathodic current of biofilm coated stainless steel for a year under different polarization intensities. The results showed that sustainable cathodic reactions were present in marine biofilms but their influence on the cathodic current was negligible until a potential was reached where the ORR could take place. Additionally seasonal variability was observed in the enhanced cathodic current in Delaware Bay biofilms. This was attributed to the seasonal variability of manganese in the water column.

Strom, Matthew James

302

Sol-gel synthesis of manganese oxides  

NASA Astrophysics Data System (ADS)

Transparent and stable manganese dioxide gels are obtained upon reduction of permanganate aqueous solutions AMnO4 [A = Li, Na, K, NH4, N(CH3)4] by fumaric acid. All xerogels are amorphous when dried at room temperature. Their thermal behavior however depends on the nature of the counter cation A+. Ammonium permanganates lead to the formation of ?- or ?-Mn2O3 while AMnO2 mixed oxides are obtained at high temperature when A = Li, Na, K. Other crystalline phases such as LiMn2O4 or Na0.7MnO2 are also formed at lower temperature around 500°C. Oxidation of these mixed oxides into sulfuric acid lead to the formation of ?- or ?-MnO2 while A+ and Mn2+ ions are released into the solution. Such manganese dioxides could be good candidates for making reversible cathodes in nonaqueous lithium batteries.

Bach, S.; Henry, M.; Baffier, N.; Livage, J.

1990-10-01

303

Steel Recycling Institute (SRI)  

NSDL National Science Digital Library

The Steel Recycling Institute (SRI) provides information and statistics on steel recycling; it was founded by a group of steel companies and the American Iron and Steel Institute (AISI). Originally a grassroots effort focused only on the recycling of steel cans, the SRI now promotes the recycling of all steel products. The SRI homepage provides online access to its three publications, The Dockside Recycler, The Recycling Magnet, and The Appliance Recycler. Recycling information is divided into four categories: cans, cars, appliances, and construction material. Users can use the recycling database to find the nearest steel recycling location. Links provides a large list of both commercial and non-commercial steel sites.

1998-01-01

304

Welding High-Strength Steels.  

National Technical Information Service (NTIS)

Recent studies of the developments in welding steels with yield strengths greater than 150 KSI have included low-alloy martensitic steels, medium-alloy martensitic steels, nickel maraging steels, and bainitic steels. Only weldments from medium-alloy marte...

P. A. Kammer D. C. Martin

1966-01-01

305

Reductive demetalation of manganese corroles: The substituent effect  

Microsoft Academic Search

The reductive demetalation of manganese corroles was investigated in CH2Cl2\\/HCl (aqueous) solvent by using SnCl2 as reducing agent. It was found that the demetalation yields depend on the substituents of corrole macrocycle significantly. Electron-rich manganese corrole undergoes reductive demetalation more easily than electron-deficient ones. The isolated reductive demetalation yield of manganese 5,10,15-tris(phenyl)corrole in present system is moderate (46%). As for

Hai Yang Liu; Ling Chen; Fei Yam; Hai Ying Zhan; Xiao Ying; Xiang Li Wang; Huan Feng Jiang; Chi Kwong Chang

2008-01-01

306

A microbial fuel cell using manganese oxide oxygen reduction catalysts  

Microsoft Academic Search

Microbial fuel cells (MFCs) are a potential method for enhanced water and waste treatment, which offer the additional benefit\\u000a of energy generation. Manganese oxide was prepared by a simple chemical oxidation using potassium permanganate. Carbon-supported\\u000a manganese oxide nanoparticles were successfully characterised as cathode materials for MFCs. The manganese oxide particles\\u000a when used in a two-chamber MFC, using inoculum from an

I. Roche; K. Katuri; K. Scott

2010-01-01

307

Structural stability in partially substituted lithium manganese spinel oxide cathode  

Microsoft Academic Search

LiMn2O4 is one of the most promising cathode materials for lithium secondary battery because of natural abundance of manganese in\\u000a the crust and its low toxicity to environment. Lithium ion can almost reversibly intercalate into or deintercalate from lithium\\u000a manganese spinel oxide LiMn2O4. A part of substitution of manganese with other transition metals brings the improvement of cycle life. We

Masataka Wakihara; Hiromasa Ikuta; Yoshiharu Uchimoto

2002-01-01

308

Manganese exposure in foundry furnacemen and scrap recycling workers  

Microsoft Academic Search

Objectives: Cast iron products are alloyed with small quantities of manganese, and foundry furnacemen are potentially exposed to manganese\\u000a during tapping and handling of smelts. Manganese is a neurotoxic substance that accumulates in the central nervous system,\\u000a where it may cause a neurological disorder that bears many similarities to Parkinson's disease. The aim of the study was to\\u000a investigate the

F. Lander; J. Kristiansen; J. M. Lauritsen

1999-01-01

309

Metabolism of manganese, iron, copper, and selenium in calves  

SciTech Connect

Sixteen male Holstein calves were used to study manganese and iron metabolism. The calves were fed one of the following diets for 18 days: control, control + iron, control + manganese, and control + iron and manganese. All calves were dosed orally with manganese-54. Tissue concentrations of manganese, iron and manganese-54 were determined. Small intestinal iron was lower in calves fed the high manganese diet than in controls. Tissue manganese-54 was lower in calves fed a high manganese diet. Fecal manganese content increased in calves fed both high manganese and high manganese-high iron diets. Serum total iron was not affected by the dietary treatments. To study the effects of high dietary levels of copper and selenium on the intracellular distributions of these two elements in liver and kidney cytosol, calves were fed one of four diets for 15 days. These were 0 and 100 ppM supplemental copper and 0 and 1 ppM added selenium. The control diet containing 0.1 ppM of selenium and 15 ppM of copper. All calves were orally dosed 48 hrs prior to sacrifice with selenium-75. A high copper diet increased copper concentrations in all intracellular liver fractions and most kidney fractions. Only the effects in the liver were significant. Less copper was found in the mitochondria fractions in liver and kidney of calves fed a high selenium diet. Three major copper-binding protein peaks were separated from the soluble fractions of calf liver and kidney. Peak 1 appeared to be the major copper-binding protein in liver and kidney cytosol of copper-loaded animals. Added selenium alone or in combination with copper accentuated the copper accumulation in this peak. Most of selenium-75 was recovered in the same peak as the copper. The results of this experiment indicated that the large molecular proteins in liver and kidney cytosol of calves play an important role in copper and selenium-75 metabolism. (ERB)

Ho, S.Y.

1981-01-01

310

Manganese toxicity to chlorophyll synthesis in tobacco callus. [Nicotiana tabacum  

SciTech Connect

Tobacco (Nicotiana tabacum) pith explants were grown on manganese containing medium. At moderate concentration (10 millimolar), manganese selectivity inhibited chlorophyll synthesis, resulting initially in growth of white callus. Several weeks later the white callus turned brown due to the accumulation of a pigment identified as protoporphyrin IX by its elution profile using high performance liquid chromatography, by its absorption spectrum, and by its fluorescence properties. At a concentration of 100 millimolar manganese the pigment accumulated without growth of the explant.

Clairmont, K.B.; Hagar, W.G.; Davis, E.A.

1986-01-01

311

Quantum Size Effects in the Properties of Non-Magnetic Americium-I (0001) Surface: A Hybrid DFT Study  

NASA Astrophysics Data System (ADS)

Hybrid density functional theory (HDFT) and a periodic slab model (up to nine layers thick) have been used to study the surface properties and electronic structure of non-magnetic Americium-I (0001) surface. The work function and surface energy of the semi-infinite surface is predicted to 3.45eV and 1.09 J/m^2 respectively. The surface properties, namely the surface energy, work function, and slab incremental energy exhibit no variations after five layers. A five layer slab is thus predicted to accurately model the adsorbate-induced changes in the surface properties of Americium-I (0001). The electronic structure is in excellent agreement with recent photoemission spectroscopy data. A layer-by-layer examination 5f electron localization using the thickest slab clearly indicates that the 5f electrons are localized on each layer and the nature of the localization is independent of the local geometry indicating that there is no variation in the 5f electron localization at the surface and in the bulk region.

Atta-Fynn, Raymond; Ray, Asok

2010-03-01

312

Enhanced magnetic and electrical properties in amorphous Ge:Mn thin films by non-magnetic codoping  

NASA Astrophysics Data System (ADS)

Amorphous Ge1-xMnx thin films have been prepared by co-depositing Ge and Mn on SiO2/Si using an ultrahigh vacuum molecular beam epitaxy system. Across a range of growth temperatures and Mn concentrations (2.8 at. %, 10.9 at. %, and 21.3 at. %), we achieved enhanced magnetic and electrical properties with non-magnetic codopants dispersed in the films. Self-assembled Mn-rich amorphous nanostructures were observed in the amorphous Ge matrix, either as isolated nanoclusters or as nanocolumns, depending on Mn concentration. The ferromagnetic saturation moments were found to increase with Mn concentration and reached a maximum of 0.7 ?B/Mn in the as-grown samples. Two magnetic transition temperatures around 15 K and 200 K were observed in these amorphous MBE-grown samples. Coercivity is considered within the context of local magnetic anisotropy. The anomalous Hall effect confirmed a strong correlation between the magnetization and transport properties, indicating that global ferromagnetic coupling was carrier-mediated rather than through direct exchange. In addition, negative magnetoresistance was detected from 5 K to room temperature.

Yin, Wenjing; Kell, Copeland D.; He, Li; Dolph, Melissa C.; Duska, Chris; Lu, Jiwei; Hull, Robert; Floro, Jerrold A.; Wolf, Stuart A.

2012-02-01

313

Determination of manganese in human brain samples  

Microsoft Academic Search

A method is presented for the determination of manganese (Mn) in human tissue samples (especially brain) by graphite furnace atomic absorption spectrophotometry (GFAAS). After complete digestion by a mixture of concentrated nitric acid (HNO3)\\/concentrated perchloric acid (HClO4) (50:50, v\\/v), the samples are assayed on a Perkin-Elmer 5100 PC apparatus, equipped with transversal graphite tubes and a Mn-specific hollow cathode lamp.

A. Tracqui; J. Tayot; P. Kintz; G. Alves; M. A. Bosque; P. Mangin

1995-01-01

314

Electrochemical lithium intercalation in disordered manganese oxides  

Microsoft Academic Search

Four highly disordered manganese oxides were prepared by reduction of sodium permanganate by chloride, iodide, hydrogen peroxide or oxalate in aqueous medium containing a large excess of Li+ ions, yielding hydrated oxides with Mn valence in the range 3.80–3.92. Thermogravimetric studies showed that the iodide-reduced oxide can be dehydrated to 92% at 240°C, while the other three ones retain water

A Ibarra Palos; M Anne; P Strobel

2001-01-01

315

Lithium-manganese oxide rechargeable battery  

Microsoft Academic Search

A new type of rechargeable battery in which lithium ions shuttle between a lithium-manganese oxide electrode and a carbon electrode was unveiled recently by chemists from Bell Communications Research (Bellcore), Red Bank, N.J. The new battery--still experimental--is safer, longer lasting, and potentially cheaper to manufacture than other lithium-ion batteries. In addition, it provides three times the energy of nickel-cadmium cells,

Dagani

1993-01-01

316

Lithium Manganese Oxide Prepared by Flux Methods  

Microsoft Academic Search

Plate-like crystals of spinel-type lithium manganese oxide with sizes in the micrometer range were obtained in a flux system\\u000a of LiCl-Mn(NO3)2. The crystals were grown by a dissolution-recrystallization mechanism. Polyhedral crystals with sizes in the millimeter range\\u000a were grown in a flux system of LiCl-Mn(NO3)2 by an evaporation-recrystallization mechanism.

W. Tang; Q. Feng; X. Yang; R. Chitrakar; K. Ooi

317

EXAFS studies of lithium manganese oxides  

Microsoft Academic Search

Lithium manganese oxides are the subject of intense interest due to their potential application as the positive electrode in rechargeable lithium batteries. Strategies to improve the performance include variation of the chemical structure, via doping with other cations, and changing the crystal structure. In this paper the local structure in spinel LiMn2O4, both pure and doped with Co, Ni, Ga

A. V. Chadwick; S. L. P. Savin; R. J. Packer; A. N. Blacklocks; R. A. Davis; M. S. Islam

2005-01-01

318

Sol-gel synthesis of manganese oxides  

Microsoft Academic Search

Transparent and stable manganese dioxide gels are obtained upon reduction of permanganate aqueous solutions AMnO4 [A = Li, Na, K, NH4, N(CH3)4] by fumaric acid. All xerogels are amorphous when dried at room temperature. Their thermal behavior however depends on the nature of the counter cation A+. Ammonium permanganates lead to the formation of alpha- or gamma-Mn2O3 while AMnO2 mixed

S. Bach; M. Henry; N. Baffier; J. Livage

1990-01-01

319

EXAFS studies of lithium manganese oxides  

NASA Astrophysics Data System (ADS)

Lithium manganese oxides are the subject of intense interest due to their potential application as the positive electrode in rechargeable lithium batteries. Strategies to improve the performance include variation of the chemical structure, via doping with other cations, and changing the crystal structure. In this paper the local structure in spinel LiMn2O4, both pure and doped with Co, Ni, Ga and In, and layered LiMnO2 have been investigated by EXAFS spectroscopy.

Chadwick, A. V.; Savin, S. L. P.; Packer, R. J.; Blacklocks, A. N.; Davis, R. A.; Islam, M. S.

2005-01-01

320

Manganese peroxidase from Phanerochaete crassa WD1694  

Microsoft Academic Search

A manganese peroxidase from the white-rot fungus Phanerochaete crassa WD1694, that had exhibited very high ability to bleach unbleached kraft pulp, was purified and characterized. The MnP was purified by adsorption-desorption on DEAE-Sepahrose CL-6B and FPLC on DEAE-Toyopearl. The purified MnP gave a single band at 48.3 kDa on SDS-PAGE and could be separated into four isozymes at extremely close

TAKANO Mariko; NAKAMURA Masaya; NISHIDA Atsumi; ISHIHARA Mitsuro

2004-01-01

321

Experimental Analysis and Modelling of Fe-Mn-Al-C Duplex Steel Mechanical Behaviour  

SciTech Connect

A new variety of duplex steels with high content of manganese and aluminum has been elaborated in Arcelor Research. These steels contain two phases: austenite and ferrite combining the best features of austenitic and ferritic steels. In this work, four duplex steels with different chemical composition and phase volume fraction are studied. The evolution of internal stresses for the two phases has been determined by X-ray diffraction during an in situ tensile test. These measurements results were used to determine the mechanical behaviour of the duplex steel using a micromechanical approach by scale transition for tensile tests. Though a good agreement between experiments and simulations is found at the macroscopic level, the calculated internal stresses of the austenitic phase do not match experimental results. These discrepancies are attributed to (i) a bad estimation of the austenite yield stress or (ii) the presence of kinematic hardening in the austenitic phase. A new step is then proposed to test these two hypotheses.

Shiekhelsouk, M. N.; Favier, V.; Cherkaoui, M. [LPMM, ENSAM Metz, 4 rue Augustin Fresnel, Technopole, 57078 Metz Cedex 3 (France); Inal, K. [MECASURF, ENSAM Aix, 2 cours des Arts et Metiers, 13617 Aix en Provence (France); Bouaziz, O. [ARCELOR RESEARCH, Voie Romaine, BP 30320, F-57283 Maiziere les Metz Cedex (France)

2007-04-07

322

Experimental Analysis and Modelling of Fe-Mn-Al-C Duplex Steel Mechanical Behaviour  

NASA Astrophysics Data System (ADS)

A new variety of duplex steels with high content of manganese and aluminum has been elaborated in Arcelor Research. These steels contain two phases: austenite and ferrite combining the best features of austenitic and ferritic steels. In this work, four duplex steels with different chemical composition and phase volume fraction are studied. The evolution of internal stresses for the two phases has been determined by X-ray diffraction during an in situ tensile test. These measurements results were used to determine the mechanical behaviour of the duplex steel using a micromechanical approach by scale transition for tensile tests. Though a good agreement between experiments and simulations is found at the macroscopic level, the calculated internal stresses of the austenitic phase do not match experimental results. These discrepancies are attributed to (i) a bad estimation of the austenite yield stress or (ii) the presence of kinematic hardening in the austenitic phase. A new step is then proposed to test these two hypotheses.

Shiekhelsouk, M. N.; Favier, V.; Inal, K.; Bouaziz, O.; Cherkaoui, M.

2007-04-01

323

Manganese in the U.S. gasoline supply.  

PubMed

Methylcyclopentadienyl manganese tricarbonyl (MMT) is an organic manganese compound recently approved for use in the United States as a gasoline additive. MMT use is expected to increase. This Commentary analyzes the impact of MMT use on population exposure to manganese, the health effects associated with manganese exposure, and the possibility that MMT use will lead to toxicity in the population. Although MMT use would result in only a small increment in most people's manganese exposure, certain populations will be disproportionately exposed. Although manganese is an essential nutrient at low levels, high-level manganese exposure leads to a characteristic severe nervous system toxicity. Pulmonary toxicity also occurs at high levels of exposure, and developmental toxicity to fetuses is an important concern based on more limited data. Selected subpopulations may be especially susceptible to the toxic effects of manganese. The critical question is whether the additional population exposure to manganese that would result from widespread MMT use would lead to toxic effects. Currently available evidence does not permit firm conclusions. Common sense and prudence therefore dictate that MMT not be used until further data are available and its safety is confirmed. Several measures are recommended to address the impending use of MMT in the U.S. gasoline supply. PMID:8986262

Frumkin, H; Solomon, G

1997-01-01

324

A biokinetic model for manganese for use in radiation protection  

SciTech Connect

The ICRP is updating its recommendations regarding occupational exposure to radionuclides including the biokinetic models used to derive dose coefficients and assess bioassay data for internally deposited radionuclides. This report reviews biokinetic data for manganese and proposes a biokinetic model for systemic manganese consistent with the current database. The model provides a more detailed and biologically realistic description of the movement of absorbed manganese in the body than the model currently recommended by the International Commission on Radiological Protection (ICRP). The proposed model and current ICRP model yield broadly similar estimates of dose per unit activity of inhaled or ingested radio-manganese but differ substantially with regard to interpretation of bioassay data.

Leggett, Richard Wayne [ORNL

2011-01-01

325

Manganese-enhanced magnetic resonance microscopy of mineralization.  

PubMed

Paramagnetic manganese (II) can be employed as a calcium surrogate to sensitize magnetic resonance microscopy (MRM) to the processing of calcium during bone formation. At high doses, osteoblasts can take up sufficient quantities of manganese, resulting in marked changes in water proton T(1), T(2) and magnetization transfer ratio values compared to those for untreated cells. Accordingly, inductively coupled plasma mass spectrometry (ICP-MS) results confirm that the manganese content of treated cell pellets was 10-fold higher than that for untreated cell pellets. To establish that manganese is processed like calcium and deposited as bone, calvaria from the skull of embryonic chicks were grown in culture medium supplemented with 1 mM MnCl(2) and 3 mM CaCl(2). A banding pattern of high and low T(2) values, consistent with mineral deposits with high and low levels of manganese, was observed radiating from the calvarial ridge. The results of ICP-MS studies confirm that manganese-treated calvaria take up increasing amounts of manganese with time in culture. Finally, elemental mapping studies with electron probe microanalysis confirmed local variations in the manganese content of bone newly deposited on the calvarial surface. This is the first reported use of manganese-enhanced MRM to study the process whereby calcium is taken up by osteoblasts cells and deposited as bone. PMID:17707172

Chesnick, Ingrid E; Todorov, Todor I; Centeno, Jose A; Newbury, Dale E; Small, John A; Potter, Kimberlee

2007-01-16

326

Deposition of manganese in a drinking water distribution system.  

PubMed Central

The deposition of manganese in a water distribution system with manganese-related "dirty water" problems was studied over a 1-year period. Four monitoring laboratories with Robbins biofilm sampling devices fitted to the water mains were used to correlate the relationship among manganese deposition, the level of manganese in the water, and the chlorination conditions. Manganese deposition occurred by both chemical and microbial processes. Chemical deposition occurred when Mn(II) not removed during water treatment penetrated the filters and entered the distribution system, where it was oxidized by chlorine and chlorine dioxide used for disinfection. Microbial deposition occurred in areas with insufficient chlorination to control the growth of manganese-depositing biofilm. At 0.05 mg of Mn(II) per liter, the chemical deposition rate was much greater than microbial deposition. Significant deposition occurred at 0.03 mg of manganese per liter, and dirty water complaints were not eliminated until manganese levels were continuously less than 0.02 mg/liter and chlorination levels were greater than 0.2 mg/liter. A guideline level of 0.01 mg of manganese per liter is recommended. Images

Sly, L I; Hodgkinson, M C; Arunpairojana, V

1990-01-01

327

Manganese-Based Magnets: Manganese-Based Permanent Magnet with 40 MGOe at 200°C  

SciTech Connect

REACT Project: PNNL is working to reduce the cost of wind turbines and EVs by developing a manganese-based nano-composite magnet that could serve as an inexpensive alternative to rare-earth-based magnets. The manganese composite, made from low-cost and abundant materials, could exceed the performance of today’s most powerful commercial magnets at temperature higher than 200°C. Members of PNNL’s research team will leverage comprehensive computer high-performance supercomputer modeling and materials testing to meet this objective. Manganese-based magnets could withstand higher temperatures than their rare earth predecessors and potentially reduce the need for any expensive, bulky engine cooling systems for the motor and generator. This would further contribute to cost savings for both EVs and wind turbines.

None

2012-01-01

328

Problems of chronic manganese poisoning on the basis of investigations of workers at a manganese alloy foundry  

Microsoft Academic Search

In 46 persons among 119 workers at a foundry producing manganese alloy, manganese levels of over 20 µg% were found in the blood without marked objective symptoms of manganese poisoning. Comparison with a control group showed differences in magnesium and calcium levels, AlAT, AspAT, LDH, LAP activities, albumin, a1- and ?-globulin, bilirubin, cholesterol levels in serum and hemoglobin and reduced

G. Jonderko; A. Kujawska; H. Langauer-Lewowicka

1971-01-01

329

Manganese exposures in Toronto during use of the gasoline additive, methylcyclopentadienyl manganese tricarbonyl  

Microsoft Academic Search

A year-long population-weighted study of personal exposures to particulate matter (PM2.5) was conducted in Toronto while the manganese-containing additive, methylcyclopentadienyl manganese tricarbonyl (MMT), was present in gasoline at an average level of 11.9 mg Mn\\/l, which was higher than the maximum of 8.3 mg Mn\\/l allowed in the U.S. In this study, 925 three-day personal samples of PM2.5 (air concentration

KENNY S CRUMP

2000-01-01

330

Radiation-induced segregation in FFTF-irradiated austenitic stainless steels  

NASA Astrophysics Data System (ADS)

Analytical electron microscopy has been applied to radiation-induced segragation (RIS) to defefct sinks in two austenitic stainless steels irradiated in the Fast Flux Test Facility to ?15 dpa at 520°C. RIS to faulted dislocation loops has been shown to be strongly dependent on loop size. Several mechanisms for this effect are discussed, including increased vacancy-driven RIS for large dislocation loop sizes. The spatial distribution of solutes near large dislocation loops is consistent with dominance of the inverse Kirkendall effect and not with an interstitial mechanism of RIS. In a manganese-stabilized austenite (EP838), manganese is the species strongly depleted at boundaries, resulting in little chromium depletion relative to that in USPCA. Therefore, EP838 should exhibit greater resistance to radiation-induced sensitization. Manganese depletion at grain boundaries in the EP838 may induce a loss of austenite stability, but that effect will be offset in part by an enrichment of nickel.

Kenik, E. A.; Hojou, K.

1992-09-01

331

Non-equilibrium Chemistry of Dynamically Evolving Prestellar Cores. I. Basic Magnetic and Non-magnetic Models and Parameter Studies  

NASA Astrophysics Data System (ADS)

We combine dynamical and non-equilibrium chemical modeling of evolving prestellar molecular cloud cores and investigate the evolution of molecular abundances in the contracting core. We model both magnetic cores, with varying degrees of initial magnetic support, and non-magnetic cores, with varying collapse delay times. We explore, through a parameter study, the competing effects of various model parameters in the evolving molecular abundances, including the elemental C/O ratio, the temperature, and the cosmic-ray ionization rate. We find that different models show their largest quantitative differences at the center of the core, whereas the outer layers, which evolve slower, have abundances which are severely degenerate among different dynamical models. There is a large range of possible abundance values for different models at a fixed evolutionary stage (central density), which demonstrates the large potential of chemical differentiation in prestellar cores. However, degeneracies among different models, compounded with uncertainties induced by other model parameters, make it difficult to discriminate among dynamical models. To address these difficulties, we identify abundance ratios between particular molecules, the measurement of which would have maximal potential for discrimination among the different models examined here. In particular, we find that the ratios between NH3 and CO, NH2 and CO, and NH3 and HCO+ are sensitive to the evolutionary timescale, and that the ratio between HCN and OH is sensitive to the C/O ratio. Finally, we demonstrate that measurements of the central deviation (central depletion or enhancement) of abundances of certain molecules are good indicators of the dynamics of the core.

Tassis, Konstantinos; Willacy, Karen; Yorke, Harold W.; Turner, Neal J.

2012-07-01

332

A Hybrid Density Functional Study of Atomic Hydrogen and Oxygen Adsorptions on the (0001) Surface of Non-Magnetic DHCP Americium  

NASA Astrophysics Data System (ADS)

As our group have recently shown^+, hybrid density functional theory (HDFT) which replaces a fraction (40%) of approximate DFT exchange with exact Hartree-Fock exchange yield structural, magnetic, and electronic properties for Americium-I that are in excellent agreement with experimental data. As a natural progression, ab initio calculations for atomic adsorptions on the (0001) surface of non-magnetic americium have been performed using HDFT. The americium surface is modeled by a seven-layer slab using inversion symmetry consisting of one atom per layer and non-magnetic ABAC stacking arrangement of these layers. Top, bridge, hcp and fcc chemisorption sites have been investigated with energies optimized with respect to the adatom distance from the surface. Details of the chemisorptions processes as well as comparisons of different sites will be presented. ^+ R. Atta-Fynn and A. K. Ray, Chemical Physics Letters, 482, 223-227 (2009).

Amdani-Moten, Shafaq; Atta-Fynn, Raymond; Ray, Asok

2010-03-01

333

Three manganese oxide-rich marine sediments harbor similar communities of acetate-oxidizing manganese-reducing bacteria  

PubMed Central

Dissimilatory manganese reduction dominates anaerobic carbon oxidation in marine sediments with high manganese oxide concentrations, but the microorganisms responsible for this process are largely unknown. In this study, the acetate-utilizing manganese-reducing microbiota in geographically well-separated, manganese oxide-rich sediments from Gullmar Fjord (Sweden), Skagerrak (Norway) and Ulleung Basin (Korea) were analyzed by 16S rRNA-stable isotope probing (SIP). Manganese reduction was the prevailing terminal electron-accepting process in anoxic incubations of surface sediments, and even the addition of acetate stimulated neither iron nor sulfate reduction. The three geographically distinct sediments harbored surprisingly similar communities of acetate-utilizing manganese-reducing bacteria: 16S rRNA of members of the genera Colwellia and Arcobacter and of novel genera within the Oceanospirillaceae and Alteromonadales were detected in heavy RNA-SIP fractions from these three sediments. Most probable number (MPN) analysis yielded up to 106 acetate-utilizing manganese-reducing cells cm?3 in Gullmar Fjord sediment. A 16S rRNA gene clone library that was established from the highest MPN dilutions was dominated by sequences of Colwellia and Arcobacter species and members of the Oceanospirillaceae, supporting the obtained RNA-SIP results. In conclusion, these findings strongly suggest that (i) acetate-dependent manganese reduction in manganese oxide-rich sediments is catalyzed by members of taxa (Arcobacter, Colwellia and Oceanospirillaceae) previously not known to possess this physiological function, (ii) similar acetate-utilizing manganese reducers thrive in geographically distinct regions and (iii) the identified manganese reducers differ greatly from the extensively explored iron reducers in marine sediments.

Vandieken, Verona; Pester, Michael; Finke, Niko; Hyun, Jung-Ho; Friedrich, Michael W; Loy, Alexander; Thamdrup, Bo

2012-01-01

334

Three manganese oxide-rich marine sediments harbor similar communities of acetate-oxidizing manganese-reducing bacteria.  

PubMed

Dissimilatory manganese reduction dominates anaerobic carbon oxidation in marine sediments with high manganese oxide concentrations, but the microorganisms responsible for this process are largely unknown. In this study, the acetate-utilizing manganese-reducing microbiota in geographically well-separated, manganese oxide-rich sediments from Gullmar Fjord (Sweden), Skagerrak (Norway) and Ulleung Basin (Korea) were analyzed by 16S rRNA-stable isotope probing (SIP). Manganese reduction was the prevailing terminal electron-accepting process in anoxic incubations of surface sediments, and even the addition of acetate stimulated neither iron nor sulfate reduction. The three geographically distinct sediments harbored surprisingly similar communities of acetate-utilizing manganese-reducing bacteria: 16S rRNA of members of the genera Colwellia and Arcobacter and of novel genera within the Oceanospirillaceae and Alteromonadales were detected in heavy RNA-SIP fractions from these three sediments. Most probable number (MPN) analysis yielded up to 10(6) acetate-utilizing manganese-reducing cells cm(-3) in Gullmar Fjord sediment. A 16S rRNA gene clone library that was established from the highest MPN dilutions was dominated by sequences of Colwellia and Arcobacter species and members of the Oceanospirillaceae, supporting the obtained RNA-SIP results. In conclusion, these findings strongly suggest that (i) acetate-dependent manganese reduction in manganese oxide-rich sediments is catalyzed by members of taxa (Arcobacter, Colwellia and Oceanospirillaceae) previously not known to possess this physiological function, (ii) similar acetate-utilizing manganese reducers thrive in geographically distinct regions and (iii) the identified manganese reducers differ greatly from the extensively explored iron reducers in marine sediments. PMID:22572639

Vandieken, Verona; Pester, Michael; Finke, Niko; Hyun, Jung-Ho; Friedrich, Michael W; Loy, Alexander; Thamdrup, Bo

2012-05-10

335

Blood Manganese and Alcohol Consumption Interact on Mood States Among Manganese Alloy Production Workers  

Microsoft Academic Search

Long-term exposure to manganese (Mn) can induce neurotoxic effects including neuromotor, neurocognitive and neuropsychiatric effects, but there is a great interpersonal variability in the occurrence of these effects. It has recently been suggested that blood Mn (MnB) may interact with alcohol use disorders, accentuating neuropsychiatric symptoms. The objective of the present study was to explore a possible interaction between alcohol

Maryse Bouchard; Donna Mergler; Mary Baldwin; Marie-Pascale Sassine; Rosemarie Bowler; Brenda MacGibbon

2003-01-01

336

Stress-Relief Heat Treatment of Manganese-Nickel-Aluminum Bronze and Manganese-Bronze Weldments.  

National Technical Information Service (NTIS)

Tensile properties, weldability, general corrosion, and corrosion-fatigue properties were determined as a function of stress-relief heat treatment for both cast Mn-Ni-Al bronze and manganese-bronze propeller alloys. It was found that Mn-Ni-Al bronze is su...

C. A. Zanis

1975-01-01

337

Wood surface protection with some titanium, zirconium and manganese compounds  

Microsoft Academic Search

Thin radiata pine veneers were treated with a range of titanium, zirconium and manganese compounds and exposed to natural weathering. Veneer weight and tensile strength losses were used to assess the protective efficacy of the compounds. The oxidative manganese compounds potassium permanganate and manganic acetate restricted both weight and tensile strength loss of treated wood veneers during weathering. FTIR internal

K. J. Schmalzl; P. D. Evans

2003-01-01

338

Active Transport of Manganese in Isolated Membranes of Escherichia coli  

PubMed Central

Accumulation of manganese was measured in subcellular membrane vesicles isolated from Escherichia coli. Accumulation of 54Mn by vesicles in 0.5 m sucrose is stimulated by glucose and d-lactate and is inhibited by metabolic poisons such as dinitrophenol, m-chlorophenyl carbonylcyanide hydrazone, valinomycin, and nigericin. Manganese uptake by vesicles requires 10 mm calcium, which is not required for uptake of manganese by intact cells. The calcium requirement is specific and cannot be replaced by magnesium, sodium, or potassium. Strontium can replace calcium but is somewhat less effective than calcium. The uptake of manganese is via a manganese-specific system which shows saturation kinetics with manganese with a Km of 8 × 10?6m and a Vmax of 4 nmoles per min per g (wet weight) at 25 C. Magnesium and calcium do not compete for uptake. The accumulated manganese can be released from the vesicles by lipid active agents such as toluene, and can be exchanged for external manganese.

Bhattacharyya, Pinakilal

1970-01-01

339

Coupled anoxic nitrification\\/manganese reduction in marine sediments  

Microsoft Academic Search

Pore water and solid phase distributions of oxygen, manganese, and nitrogen from hemipelagic and shelf sediments sometimes indicate a close coupling between the manganese and nitrogen redox cycles. Reaction coupling must be sustained in part by biological reworking of Mn-oxide-rich surface sediments into underlying anoxic zones. Surface sediment from Long Island Sound (USA) was used in laboratory experiments to simulate

Stefan Hulth; Robert C Aller; Franck Gilbert

1999-01-01

340

Removal of Manganese from Mine Drainage by Ozone and Chlorine.  

National Technical Information Service (NTIS)

This research was directed toward an examination of methods by which coal mine water could be treated for removal of manganese. In order to remove manganese from mine water, strong oxidizers must be employed to oxidize it to the (+4) oxidation state in wh...

R. B. Rozelle H. A. Swain

1975-01-01

341

Corrosion and protection characteristics of zinc and manganese phosphate coatings  

Microsoft Academic Search

The corrosion and protection characteristics of zinc and manganese phosphate coatings in aqueous solutions are investigated by means of physical methods and electrochemical measurements. The results show that the insulation property of zinc phosphate coating is better than that of manganese phosphate, but the porosity of the former is inferior to that of the latter. The anodic current of coated

D. Weng; P. Jokiel; A. Uebleis; H. Boehni

1997-01-01

342

Non-heme manganese catalase - the 'other' catalase  

PubMed Central

Non-heme manganese catalases are widely distributed over microbial life and represent an environmentally important alternative to heme-containing catalases in antioxidant defense. Manganese catalases contain a binuclear manganese complex as their catalytic active site rather than a heme, and cycle between Mn2(II,II) and Mn2(III,III) states during turnover. X-ray crystallography has revealed the key structural elements of the binuclear manganese active site complex that can serve as the starting point for computational studies on the protein. Four manganese catalase enzymes have been isolated and characterized, and the enzyme appears to have a broad phylogenetic distribution including both bacteria and archae. More than 100 manganese catalase genes have been annotated in genomic databases, although the assignment of many of these putative manganese catalases needs to be experimentally verified. Iron limitation, exposure to low levels of peroxide stress, thermostability and cyanide resistance may provide the biological and environmental context for the occurrence of manganese catalases.

Whittaker, James W.

2012-01-01

343

Non-heme manganese catalase--the 'other' catalase.  

PubMed

Non-heme manganese catalases are widely distributed over microbial life and represent an environmentally important alternative to heme-containing catalases in antioxidant defense. Manganese catalases contain a binuclear manganese complex as their catalytic active site rather than a heme, and cycle between Mn(2)(II,II) and Mn(2)(III,III) states during turnover. X-ray crystallography has revealed the key structural elements of the binuclear manganese active site complex that can serve as the starting point for computational studies on the protein. Four manganese catalase enzymes have been isolated and characterized, and the enzyme appears to have a broad phylogenetic distribution including both bacteria and archae. More than 100 manganese catalase genes have been annotated in genomic databases, although the assignment of many of these putative manganese catalases needs to be experimentally verified. Iron limitation, exposure to low levels of peroxide stress, thermostability and cyanide resistance may provide the biological and environmental context for the occurrence of manganese catalases. PMID:22198285

Whittaker, James W

2011-12-16

344

Chitosan Clad Manganese Doped Zinc Suiphide Nanoparticles as Biological Labels  

Microsoft Academic Search

Here the authors report the synthesis in aqueous media of redispersible zinc sulphide quantum dots doped with manganese, capped by biocompatible 'chitosan' molecules. The nanoparticles show highly efficient luminescence with a peak at around 590 nm that has been correlated to the manganese dopants. The synthesis involves very simple precipitation techniques that may lead to the development of a cost

H. C. Warad; C. Thanachayanont; G. Tumcharern; J. Dutta

2007-01-01

345

Acoustic Scattering Analysis for Remote Sensing of Manganese Nodules  

Microsoft Academic Search

The theory of the scattering of plane waves in a fluid medium by an isotropic elastic sphere representing a manganese nodule is developed. Scattering cross sections were computed using the theory and the results are presented graphically. The scattering cross section and the reflectivity factor govern the characteristic acoustic signature of the Pacific where manganese nodules are present. Preliminary experimental

Yushieh Ma

1982-01-01

346

OPTICS OF A TWO-PASS ERL AS AN ELECTRON SOURCE FOR A NON-MAGNETIZED RHIC-II ELECTRON COOLER.  

SciTech Connect

Non-magnetized electron cooling of RHIC requires an electron beam energy of 54.3 MeV, electron charge per bunch of 5 nC, normalized rms beam emittance of 4 mm-mrad, and rms energy spread of 4e-04 [I]. In this paper we describe a lattice of a two-pass SRF energy recovery linac (ERL) and results of a PARMELA simulation that provides electron beam parameters satisfying RHIC electron cooling requirements.

KAYRAN,D.

2007-06-25

347

Terrestrial manganese-53 — A new monitor of Earth surface processes  

NASA Astrophysics Data System (ADS)

We report the first systematic study of the terrestrial cosmogenic radionuclide manganese-53 ( T1/2 = 3.7 Ma) measured in thirteen samples from nine dolerite surfaces in the Dry Valleys, Antarctica. The terrestrial manganese-53 concentrations correlate well with cosmic-ray-produced helium-3 and neon-21 concentrations in the same samples, implying that the manganese-53 is produced continuously in situ and retained quantitatively over millions of years. The terrestrial manganese-53 production rate determination normalized to iron (the only important target element) and to high-latitude and sealevel yields a value of P53 = 103 ± 11 atoms yr - 1 (g Fe) - 1 . This is consistent with the theoretical value of 120 ± 18 atoms yr - 1 (g Fe) - 1 obtained from modeling calculations. Our results show that the manganese-53 concentrations in bulk terrestrial rocks can be used to monitor Earth surface processes on time-scales exceeding 10 My.

Schaefer, Joerg M.; Faestermann, Thomas; Herzog, Gregory F.; Knie, Klaus; Korschinek, Gunther; Masarik, Jozef; Meier, Astrid; Poutivtsev, Michail; Rugel, Georg; Schlüchter, Christian; Serifiddin, Feride; Winckler, Gisela

2006-11-01

348

Treatability of manganese by sodium silicate and chlorine  

SciTech Connect

Manganese sequestering by nearly simultaneous additions of sodium silicate and sodium hypochlorite was studied in laboratory-prepared waters. Under conditions of near-neutral pH and 150-250 mg/liter of alkalinity as CaCO{sub 3}, 1-2 mg manganese/liter could be sequestered for up to one day. Less effective manganese treatability was found at pH 8 than at pH 7. Additionally, at pH 7 the best results were obtained when neither silicate nor hypochlorite was added because of the slow manganese oxidation rate by oxygen alone. Aging of diluted stock silicate solutions prior to dosing also resulted in poor treatment; the presence of background silica increased the treatment effectiveness only slightly. Overall, manganese was less treatable by this method than iron under the same treatment conditions.

Robinson, F.B.; Ronk, S.K. (Tennessee Univ., Knoxville (USA))

1987-11-01

349

Manganese: brain transport and emerging research needs.  

PubMed Central

Idiopathic Parkinson's disease (IPD) represents a common neurodegenerative disorder. An estimated 2% of the U.S. population, age 65 and older, develops IPD. The number of IPD patients will certainly increase over the next several decades as the baby-boomers gradually step into this high-risk age group, concomitant with the increase in the average life expectancy. While many studies have suggested that industrial chemicals and pesticides may underlie IPD, its etiology remains elusive. Among the toxic metals, the relationship between manganese intoxication and IPD has long been recognized. The neurological signs of manganism have received close attention because they resemble several clinical disorders collectively described as extrapyramidal motor system dysfunction, and in particular, IPD and dystonia. However, distinct dissimilarities between IPD and manganism are well established, and it remains to be determined whether Mn plays an etiologic role in IPD. It is particularly noteworthy that as a result of a recent court decision, methylcyclopentadienyl Mn tricarbonyl (MMT) is presently available in the United States and Canada for use in fuel, replacing lead as an antiknock additive. The impact of potential long-term exposure to low levels of MMT combustion products that may be present in emissions from automobiles has yet to be fully evaluated. Nevertheless, it should be pointed out that recent studies with various environmental modeling approaches in the Montreal metropolitan (where MMT has been used for more than 10 years) suggest that airborne Mn levels were quite similar to those in areas where MMT was not used. These studies also show that Mn is emitted from the tail pipe of motor vehicles primarily as a mixture of manganese phosphate and manganese sulfate. This brief review characterizes the Mn speciation in the blood and the transport kinetics of Mn into the central nervous system, a critical step in the accumulation of Mn within the brain, outlines the potential susceptibility of selected populations (e.g., iron-deficient) to Mn exposure, and addresses future research needs for Mn.

Aschner, M

2000-01-01

350

Peripheral biomarkers and exposure to manganese.  

PubMed

Biochemical mechanisms underlying manganese (Mn) toxicity include dopamine (DA) auto-oxidation and free radical generation with subsequent neuronal damage. A neuroendocrine approach based on the measurement of serum prolactin (PRL) has been proposed to assess the tonic inhibition of pituitary lactotrope cells by the tubero-infundibular DA system. Low level exposure to Mn oxides in industrial settings is associated with a shift in the distribution of serum PRL towards higher levels as compared to matched controls. The follow-up of a small cohort of workers from a ferro-manganese plant showed that the increased prevalence of abnormally high PRL values is stable over time. Although the mechanistic basis for their application is less straightforward, other biochemical markers such as dopamine beta hydroxylase and monoamine oxidase Type B, have also been assessed. Contrary to PRL levels, these markers cannot be recommended to monitor early biochemical effects of manganese exposure at the workplace. Early biochemical events can be modified by genetically determined individual differences. Owing to the possible role of a reduced capacity of glutathione conjugation as a risk factor increasing the susceptibility to the action of free radicals generated in the presence of Mn, the class mu glutathione S transferase (GSTM1) genotype has also been assessed in workers occupationally exposed. However, the GSTM1 null genotype does not appear to play an important role in the susceptibility to biochemical effects of Mn. A logistic model of the dose-response relationship based on urinary Mn as marker of exposure indicates that the benchmark dose corresponds to Mn levels as low as 0.4 microgram/l. This would imply that environmental exposure to Mn may contribute to abnormally high serum PRL in the general population. PMID:10385899

Smargiassi, A; Mutti, A

351

AM1* parameters for manganese and iron.  

PubMed

We report the parameterization of AM1* for the elements manganese and iron. The basis sets for both metals contain one set each of s-, p- and d-orbitals. AM1* parameters are now available for H, C, N, O and F (which use the original AM1 parameters), Al, Si, P, S, Cl, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Br, Zr, Mo, I and Au. The performance and typical errors of AM1* are discussed for Mn and Fe, and are compared with available NDDO Hamiltonians. PMID:19937261

Kayi, Hakan; Clark, Timothy

2009-11-24

352

Salicylato complexes of manganese(II)  

SciTech Connect

Salicylato complexes of manganese(II) with the formulas (Mn(Hsal)/sub 2/(H/sub 2/O)/sub 2/) H/sub 2/O and (Mn(OH)(Hsal)H/sub 2/O), where Hsal denotes the anion of salicyclic acid H/sub 2/sal, have been synthesized and isolated in the free state. Their properties have been studied, and their x-ray diffraction patterns and IR absorption spectra (400-4200 cm/sup -1/) have been obtained.

Kharitonov, Yu.Ya.; Tuiebakhova, Z.K.

1985-10-01

353

DSCcharacterisation of chemically reduced electrolytic manganese dioxide  

Microsoft Academic Search

The thermal decomposition of electrolytic\\u000a manganese dioxide (EMD), in an inert atmosphere, and the effect of chemical\\u000a reduction on EMD, using 2-propanol under reflux (82C), was investigated\\u000a by differential scanning calorimetry (DSC). This study is an extension of\\u000a a study investigating the thermal decomposition of EMD and reduced EMD by\\u000a TG-MS (J. Therm. Anal. Cal., 80 (2005)625)). The DSC characterisation

B. Liu; P. S. Thomas; A. S. Ray; R. P. Williams; S. W. Donne

2007-01-01

354

Manganese enzymes with binuclear active sites  

SciTech Connect

The purpose of this article is twofold. First, to review the recent literature dealing with the mechanisms of catalysis by binuclear manganese enzymes. Second, to summarize and illustrate the general principles of catalysis which distinguish binuclear metalloenzymes from monometallic centers. This review covers primarily the published literature from 1991 up to May 1996. A summary of the major structurally characterized dimanganese enzymes is given. These perform various reaction types including several redox reactions, (de)hydrations, isomerizations, (de)phosphorylation, and phosphoryl transfer. 114 refs.

Dismukes, G.C. [Princeton Univ., NJ (United States). Hoyt Lab.

1996-11-01

355

Lithium-manganese oxide rechargeable battery  

SciTech Connect

A new type of rechargeable battery in which lithium ions shuttle between a lithium-manganese oxide electrode and a carbon electrode was unveiled recently by chemists from Bell Communications Research (Bellcore), Red Bank, N.J. The new battery--still experimental--is safer, longer lasting, and potentially cheaper to manufacture than other lithium-ion batteries. In addition, it provides three times the energy of nickel-cadmium cells, the most popular type of rechargeable battery. Bellcore scientists believe the new battery could replace nickel-cadmium and small lead-acid batteries in many applications.

Dagani, R.

1993-01-04

356

Orbital anisotropy in paramagnetic manganese oxide nanostripes  

NASA Astrophysics Data System (ADS)

We have detected a clear magnetic anisotropy in the temperature and field dependent Mn L2,3 magnetic circular dichroism (MCD) spectra of 28 Å wide paramagnetic manganese oxide nanostripes, which we relate to the presence of a largely unquenched orbital moment revealed by MCD sum rule analysis. Polarization, angle, and temperature dependent linear dichroism spectra indicate that the observed anisotropy is related to a depletion of 3d states with ml=±2 orbital quantum number in the ground state of the paramagnetic system. Strongly anisotropic electrostatic coupling provides an internal source of spatial symmetry breaking which might generally yield paramagnetic anisotropy phenomena in 3d oxide nanostructures.

Altieri, S.; Allegretti, F.; Steurer, W.; Surnev, S.; Finazzi, M.; Sessi, V.; Brookes, N. B.; Valeri, S.; Netzer, F. P.

2013-06-01

357

Essentiality, toxicity, and uncertainty in the risk assessment of manganese.  

PubMed

Risk assessments of manganese by inhalation or oral routes of exposure typically acknowledge the duality of manganese as an essential element at low doses and a toxic metal at high doses. Previously, however, risk assessors were unable to describe manganese pharmacokinetics quantitatively across dose levels and routes of exposure, to account for mass balance, and to incorporate this information into a quantitative risk assessment. In addition, the prior risk assessment of inhaled manganese conducted by the U.S. Environmental Protection Agency (EPA) identified a number of specific factors that contributed to uncertainty in the risk assessment. In response to a petition regarding the use of a fuel additive containing manganese, methylcyclopentadienyl manganese tricarbonyl (MMT), the U.S. EPA developed a test rule under the U.S. Clean Air Act that required, among other things, the generation of pharmacokinetic information. This information was intended not only to aid in the design of health outcome studies, but also to help address uncertainties in the risk assessment of manganese. To date, the work conducted in response to the test rule has yielded substantial pharmacokinetic data. This information will enable the generation of physiologically based pharmacokinetic (PBPK) models capable of making quantitative predictions of tissue manganese concentrations following inhalation and oral exposure, across dose levels, and accounting for factors such as duration of exposure, different species of manganese, and changes of age, gender, and reproductive status. The work accomplished in response to the test rule, in combination with other scientific evidence, will enable future manganese risk assessments to consider tissue dosimetry more comprehensively than was previously possible. PMID:20077286

Boyes, William K

2010-01-01

358

Distributions of manganese, iron, and manganese-oxidizing bacteria in Lake Superior sediments of different organic carbon content  

Microsoft Academic Search

Profiles of oxygen, soluble and particulate manganese and iron, organic carbon and nitrogen were examined in Lake Superior sediment cores, along with the distribution and abundance of heterotrophic and manganese oxidizing bacteria. Analyses were performed using cores collected with the submersible Johnson Sea Link II. Three cores, exhibiting a range of organic carbon content, were collected from the deepest basin

Laurie L. Richardson; Kenneth H. Nealson

1989-01-01

359

An atom-probe tomographic study of the temporal evolution of the nanostructure of Fe–Cu based high-strength low-carbon steels  

Microsoft Academic Search

A three-dimensional (3D) knowledge of the atomic-scale structure is necessary for improving the design and understanding of modern materials with complex microstructures, such as high-performance steels. Local-electrode atom-probe tomography is used to obtain atom-by-atom 3D reconstructions to characterize three versions of a copper, nickel, manganese, and aluminum bearing high-strength low-carbon steel, which achieve their high tensile yield strength, up to

Dieter Isheim; R. Prakash Kolli; Morris E. Fine; David N. Seidman

2006-01-01

360

Surface nanocrystallization of 310S stainless steel and its effect on oxidation behavior  

SciTech Connect

Two techniques, unbalanced magnetron sputter deposition and high-energy short-pulsed plasma discharge, have been used to produce a nanocrystalline surface on AISI 310S stainless steel specimens. The average grain size after surface modification was estimated as {approximately} 100 nm by using atomic force microscopy. Cyclic oxidation was performed at 1,000 C with treated and untreated 310S stainless steel specimens. The oxide products formed on the specimens consisted of an outer spinel layer that was rich in chromium, iron, manganese, and nickel, and an inner chromium-rich layer. It was found that the concentrations of iron and manganese in the outer layer of treated specimens were higher, and adherence of the scale was better in the treated specimens. The observed oxidation behavior can be explained by the increase of the creep diffusion rate in the fine oxide scale formed on the nanocrystalline surfaces.

Liu, Z.; He, Y.; Gao, W. [Univ. of Auckland (New Zealand). Dept. of Chemical and Materials Engineering

1998-02-01

361

Comparative Studies of Manganese Binding in Human Breast Milk, Bovine Milk and Infant Formula1  

Microsoft Academic Search

The difference in ligand localization of manganese in human breast milk, cow's milk and infant formula was investigated. Extrinsic labeling technique was used and the different manganese-binding ligands were separated by gel permeation column chromatography. Manganese was found to bind to different ligands in human milk, cow's milk and infant formula. In human milk, manganese was bound by two high

WAI-YEE CHAN; JAMES M. BATES; J. R. ANDOWEN; M. RENNERT

362

Solution-based synthesis of manganese oxide cathodes for lithium batteries  

Microsoft Academic Search

With an objective to overcome the cyclability problems of manganese oxides, solution-based procedures are pursued to synthesize metastable manganese oxides. Reduction of permanganate with lithium iodide in an acetonitrile medium followed by heating at 250 C in vacuum gives an amorphous lithium sodium manganese oxyiodide that is intimately mixed with crystalline NaIO. On the other hand, oxidation of manganese acetate

A. Manthiram; J. Kim; S. Choi

2000-01-01

363

Dependence of tensile deformation behavior of TWIP steels on stacking fault energy, temperature and strain rate  

Microsoft Academic Search

Three experimental high manganese twinning induced plasticity (TWIP) steels were produced based on thermodynamic stacking fault energy (SFE) calculations, following the thermodynamic modeling approach originally proposed by Olson and Cohen (Metall Trans 7A (1976) 1897). At room temperature, the SFE ?SFE of the three materials varied from 20.5 to 42mJm?2. In order to study the correlation between the SFE and

S. Curtze; V.-T. Kuokkala

2010-01-01

364

High-Strength Low-Carbon Ferritic Steel Containing Cu-Fe-Ni-Al-Mn Precipitates  

Microsoft Academic Search

An investigation of a low-carbon, Fe-Cu-based steel, for Naval ship hull applications, with a yield strength of 965 MPa, Charpy V-notch absorbed impact-energy values as high as 74 J at -40 °C, and an elongation-to-failure greater than 15 pct, is presented. The increase in strength is derived from a large number density (approximately 1023 to 1024 m-3) of copper-iron-nickel-aluminum-manganese precipitates.

Semyon Vaynman; Dieter Isheim; R. Prakash Kolli; Shrikant P. Bhat; David N. Seidman; Morris E. Fine

2008-01-01

365

Thermochemistry of iron manganese oxide spinels  

SciTech Connect

Oxide melt solution calorimetry has been performed on iron manganese oxide spinels prepared at high temperature. The enthalpy of formation of (Mn{sub x}Fe{sub 1-x}){sub 3}O{sub 4} at 298K from the oxides, tetragonal Mn{sub 3}O{sub 4} (hausmannite) and cubic Fe{sub 3}O{sub 4} (magnetite), is negative from x=0 to x=0.67 and becomes slightly positive for 0.670.6) spinels of intermediate compositions. The enthalpies of formation are discussed in terms of three factors: oxidation-reduction relative to the end-members, cation distribution, and tetragonality. A combination of measured enthalpies and Gibbs free energies of formation in the literature provides entropies of mixing. {delta}S{sub mix}, consistent with a cation distribution in which all trivalent manganese is octahedral and all other ions are randomly distributed for x>0.5, but the entropy of mixing appears to be smaller than these predicted values for x<0.4.

Guillemet-Fritsch, Sophie [Centre InterUniversitaire de Recherche et d'Ingenierie des Materiaux (CIRIMAT/LCMIE), Universite Paul Sabatier, Ba-hat timent 2R1, 118, route de Narbonne, 31062 Toulouse, Cedex 04 (France); Navrotsky, Alexandra [Thermochemistry Facility and NEAT ORU, University of California at Davis, One Shields Avenue, Davis, CA 95616-877 (United States)]. E-mail: anavrotsky@ucdavis.edu; Tailhades, Philippe [Centre InterUniversitaire de Recherche et d'Ingenierie des Materiaux (CIRIMAT/LCMIE), Universite Paul Sabatier, Ba-hat timent 2R1, 118, route de Narbonne, 31062 Toulouse, Cedex 04 (France); Coradin, Herve [Centre InterUniversitaire de Recherche et d'Ingenierie des Materiaux (CIRIMAT/LCMIE), Universite Paul Sabatier, Ba-hat timent 2R1, 118, route de Narbonne, 31062 Toulouse, Cedex 04 (France); Wang Miaojun [Thermochemistry Facility and NEAT ORU, University of California at Davis, One Shields Avenue, Davis, CA 95616-877 (United States)

2005-01-15

366

Manganese-Enhanced Magnetic Resonance Imaging (MEMRI)  

PubMed Central

The use of manganese ions (Mn2+) as an MRI contrast agent was introduced over 20 years ago in studies of Mn2+ toxicity in anesthetized rats (1). Manganese-enhanced MRI (MEMRI) evolved in the late nineties when Koretsky and associates pioneered the use of MEMRI for brain activity measurements (2) as well as neuronal tract tracing (3). Currently, MEMRI has three primary applications in biological systems: (1) contrast enhancement for anatomical detail, (2) activity-dependent assessment and (3) tracing of neuronal connections or tract tracing. MEMRI relies upon the following three main properties of Mn2+: (1) it is a paramagnetic ion that shortens the spin lattice relaxation time constant (T1) of tissues, where it accumulates and hence functions as an excellent T1 contrast agent; (2) it is a calcium (Ca2+) analog that can enter excitable cells, such as neurons and cardiac cells via voltage-gated Ca2+ channels; and (3) once in the cells Mn2+ can be transported along axons by microtubule-dependent axonal transport and can also cross synapses trans-synaptically to neighboring neurons. This chapter will emphasize the methodological approaches towards the use of MEMRI in biological systems.

Massaad, Cynthia A.; Pautler, Robia G.

2012-01-01

367

Role of the medium in the character of delayed fracture of high-nitrogen steels  

Microsoft Academic Search

Halide ions efficiently accelerate corrosion processes under stresses due to adsorption of Hal-ions on high-nitrogen chromium-manganese\\u000a steels and increase in the degree of filling of the surface (in the process of the change Cl??Br?) with hydroxyhalide intermediates (FeHalOH)2?, (FeHalOH)?, and Cu2(OH)3Cl. Fracture of specimens made of 18Mn-18Cr steel in water at room temperature in the process of tests for long-term

O. I. Balyts'kyi

2000-01-01

368

Numerical and Experimental Applications of TWIP Steel in Automotive Parts  

NASA Astrophysics Data System (ADS)

Modern automotive design has been faced with the weight reduction problem to meet the CO2 emissions standard while achieving high safety and compact design. Such being the case, most car makers want to use the ultra high strength steels (UHSS). But there are several problems when such steels are used, due to presumed lack of formability. Since the disadvantage such as above, it has been suggested that UHSS need special forming methods or it should be used only limited process like simple bending, by many automotive research institutes. To overcome these shortcomings, Twinning Induced Plasticity (TWIP) steel for improved strength and formability has been developed by steel making company, including POSCO, Korea. Because of its characteristics, it is expected to be widely used in automotive parts. This paper aims at finding out several ways how to make effective use of TWIP steel in automotive parts. Especially, comprising about from 15 to 18% manganese and from 1.5 to 2% aluminum which was developed by POSCO for application of the automotive parts will be considered.

Lee, J. W.; Lim, J. H.; Choi, J. B.; Oh, P. Y.

2011-08-01

369

Steel for plastic molds and process for their heat treatment  

US Patent & Trademark Office Database

Maraging steel with improved machinability, good weldability, and high corrosion resistance, a process for the heat treatment of such a steel, as well as its use. According to the invention this steel contains (in % by weight) 0.02-0.075% carbon; 0.1-0.6% silicon; 0.5-0.9% manganese; 0.08-0.25% sulfur; maximum 0.04%; phosphorus; 12.4-15.2% chromium; 0.05-1.0% molybdenum; 0.2-1.8% nickel; maximum 0.15% vanadium; 0.1-0.45% copper; maximum 0.03% aluminum; 0.02-0.08% nitrogen; as well as optionally one or more additional alloying elements up to maximum 2.0%, residual iron, and impurities caused in manufacturing, and a ferrite percentage in the structure of less than 28% by volume. A process is also provided for the heat treatment of a maraging steel with improved machinability, which process makes an object that is through-hardened even with a large cross-section, lies essentially in that a steel block with the above composition is subjected in a first step to an annealing treatment for the formation and adjustment of a ferrite percentage in the structure and in a second step a hot forming of the same takes place, after which in a third step a soft annealing and then a thermal tempering are performed.

2005-05-17

370

Hot coal gas desulfurization with manganese-based sorbents  

SciTech Connect

The focus of work being performed on Hot Coal Gas Desulfurization at the Morgantown Energy Technology Center is primarily in the use of zinc ferrite and zinc titanate sorbents; however, prior studies indicated that an alternate sorbent, manganese dioxide-containing ore in mixture with alumina (75 wt % ore + 25 wt % Al{sub 2}O{sub 3}) may be a viable alternative to zinc-based sorbents. Manganese, for example, has a lower vapor pressure in the elemental state than zinc hence it is not as likely to undergo depletion from the sorbent surface upon loading and regeneration cycles. Also manganese oxide is less readily reduced to the elemental state than iron hence the range of reduction potentials for oxygen is somewhat greater than for zinc ferrite. In addition, thermodynamic analysis of the manganese-oxygen-sulfur system shows it to be less amenable to sulfation than zinc ferrite. Potential also exists for utilization of manganese at higher temperatures than zinc ferrite or zinc titanate. This annual topical report documents progress in pelletizing and testing via thermo-gravimetric analysis of individual pellet formulations of manganese ore/alumina combinations and also manganese carbonate/alumina with two binders, dextrin and bentonite.

Hepworth, M.T.; Ben-Slimane, R.

1994-12-01

371

Effects of manganese forms on biogenic amines in the brain and behavioral alterations in the mouse: Long-term oral administration of several manganese compounds  

SciTech Connect

This work has identified the relative toxicity of four forms of manganese, using biogenic amine levels, tissue retention, weight gain, and activity scores as criteria. Male mice were chronically treated with four forms of manganese administered orally, mixed with the diet, for 12 months. The Mn levels were higher in some parts of brain after feeding insoluble salts than after the soluble salts. The concentration of manganese was significantly increased in the liver and spleen of the manganese carbonate-exposed group, compared with the concentration in the control group. Manganese dioxide feeding lowered dopamine and increased homovanilic acid. Since manganese dioxide is a powerful oxidizing agent in organic chemistry, it possibly enhanced the oxidative metabolite of dopamine. Accumulation of manganese in the brain correlated with reduced hypothalamic dopamine levels in the manganese acetate-exposed group; and the amount of manganese accumulated correlated with the intensity of suppression of motor activity. These findings indicate that manganese dioxide is more toxic than divalent manganese. Of the divalent manganese compounds, manganese acetate seemed to have the greatest toxic effect.

Komura, Junko; Sakamoto, Michiko (Hokuriku Univ., Kanazawa (Japan))

1992-02-01

372

Characterization of Microbial Communities in Coal Mine Drainage Treatment Systems With Elevated Manganese  

Microsoft Academic Search

Sediment samples were collected from two coal mine drainage treatment sites in western Pennsylvania. Both of the sites use constructed limestone beds to passively treat acidic coal mine drainage containing elevated manganese (Mn). Site #1 has influent manganese of 150 mg\\/L and effluent manganese between 40-100 mg\\/L. Site #2 has influent manganese of 20 mg\\/L and effluent manganese of less

H. Tan; G. Zhang; W. Burgos

2007-01-01

373

Hydrolysis of an organophosphate ester by manganese dioxide.  

PubMed

Amorphous manganese dioxide facilitates the hydrolysis of p-nitrophenyl phosphate to p-nitrophenol and orthophosphate despite insignificant adsorption of p-nitrophenyl phosphate or p-nitrophenol to the manganese dioxide. At pH 8, the orthophosphate product is released into solution; at pH 4 and pH 6, some remains adsorbed. The rate of hydrolysis is an order of magnitude more rapid than the same reaction facilitated by iron oxides. Because manganese dioxides are ubiquitous components of soils and sediments, this suggests the possibility of significant abiotic pathways for the formation of bioavailable orthophosphate from phosphate ester precursors. PMID:11349282

Baldwin, D S; Beattie, J K; Coleman, L M; Jones, D R

2001-02-15

374

Influence of manganese doping in multiferroic bismuth ferrite thin films  

Microsoft Academic Search

We have examined the influence of manganese doping to the magnetic properties of manganese-doped bismuth ferrite [BiFe1?xMnxO3 (x=0, 0.05, and 0.2)] thin films grown epitaxially on (LaAlO3)0.3(Sr2AlTaO6)0.7 substrates by pulsed laser deposition technique. Manganese doping gave rise to a gradual increase of spontaneous magnetization along with the clarity of magnetic hysteresis. This enhanced magnetization can be understood by the modification

Kouhei Takahashi; Masayoshi Tonouchi

2007-01-01

375

Effect of manganese on the secretion of manganese-peroxidase by the basidiomycete Ceriporiopsis subvermispora  

Microsoft Academic Search

The ligninolytic machinery of the widely used model fungus Ceriporiopsis subvermispora includes the enzymes manganese-peroxidase (MnP) and laccase (Lcs). In this work the effect of Mn(II) on the secretion of MnP was studied. Cultures grown in the absence of Mn(II) showed high levels of mnp transcripts. However, almost no MnP enzyme was detected in the extracellular medium, either by enzymatic

Rodrigo A. Mancilla; Paulo Canessa; Augusto Manubens; Rafael Vicuña

2010-01-01

376

Manganese concentration in rat brain: manganese transport from the peripheral tissues  

Microsoft Academic Search

54Mn distribution in the brain and peripheral tissues was studied with the course of time after intravenous injection of 54MnCl2 to see manganese (Mn) transport from the peripheral tissues, i.e. the liver, to the brain. One hour after injection, 54Mn concentrations in the brain were 0.15–0.25% dose\\/g, and 54Mn was largely concentrated in the choroid plexus. One day after injection,

Atsushi Takeda; Jinko Sawashita; Shoji Okada

1998-01-01

377

Environmental contamination and human exposure to manganese – contribution of methylcyclopentadienyl manganese tricarbonyl in unleaded gasoline  

Microsoft Academic Search

The organomanganese compound MMT (methylcyclopentadienyl manganese tricarbonyl), an antiknock additive in unleaded gasoline,\\u000a has been used in Canada since 1976. Indeed, Canada is the only country where MMT is almost exclusively used. In October 1995,\\u000a by court decision the Environmental protection Agency (EPA) granted Ethyl's waiver for the use of MMT in the United States.\\u000a Paradoxically, in 1997 the federal

Joseph Zayed; Adolf Vyskocil; Greg Kennedy

1999-01-01

378

Distributions of manganese, iron, and manganese-oxidizing bacteria in Lake Superior sediments of different organic carbon content  

SciTech Connect

Profiles of oxygen, soluble and particulate manganese and iron, organic carbon and nitrogen were examined in Lake Superior sediment cores, along with the distribution and abundance of heterotrophic and manganese oxidizing bacteria. Analyses were performed using cores collected with the submersible Johnson Sea Link II. Three cores, exhibiting a range of organic carbon content, were collected from the deepest basin in Lake Superior and the north and south ends of the Caribou trough, and brought to the surface for immediate analysis. Minielectrode profiles of oxygen concentration of the three cores were carried out using a commercially available minielectrode apparatus. Oxygen depletion to less than 1% occurred within 4 cm of the surface for two of the cores, but not until approximately 15 cm for the core from the south basin of the Caribou trough. The three cores exhibited very different profiles of soluble, as well as leachable, manganese and iron, suggesting different degrees of remobilization of these metals in the sediments. Vertical profiles of viable bacterial and Mn oxidizing bacteria, determined by plating and counting, showed that aerobic heterotrophic bacteria were present at the highest concentrations near the surface and decreased steadily with depth, while Mn oxidizing bacteria were concentrated primarily at and above the oxic/anoxic interface. Soluble manganese in the pore waters, along with abundant organic carbon, appeared to enhance the presence of manganese oxidizing bacteria, even below the oxic/anoxic interface. Profiles of solid-phase leachable manganese suggested a microbial role in manganese reprecipitation in these sediments.

Richardson, L.L.; Nealson, K.H.

1989-01-01

379

Manganese abundances in Galactic bulge red giants  

NASA Astrophysics Data System (ADS)

Context. Manganese is mainly produced in type II SNe during explosive silicon burning, in incomplete Si-burning regions, and depends on several nucleosynthesis environment conditions, such as mass cut between the matter ejected and falling back onto the remnant, electron and neutron excesses, mixing fallback, and explosion energy. Manganese is also produced in type Ia SNe. Aims: The aim of this work is the study of abundances of the iron-peak element Mn in 56 bulge giants, among which 13 are red clump stars. Four bulge fields along the minor axis are inspected. The study of abundances of Mn-over-Fe as a function of metallicity in the Galactic bulge may shed light on its production mechanisms. Methods: High-resolution spectra were obtained using the FLAMES+UVES spectrograph on the Very Large Telescope. The spectra were obtained within a program to observe 800 stars using the GIRAFFE spectrograph, together with the present UVES spectra. Results: We aim at identifying the chemical evolution of manganese, as a function of metallicity, in the Galactic bulge. We find [Mn/Fe] ~ -0.7 at [Fe/H] ~ -1.3, increasing to a solar value at metallicities close to solar, and showing a spread around - 0.7 ? [Fe/H] ? -0.2, in good agreement with other work on Mn in bulge stars. There is also good agreement with chemical evolution models. We find no clear difference in the behaviour of the four bulge fields. Whereas [Mn/Fe] vs. [Fe/H] could be identified with the behaviour of the thick disc stars, [Mn/O] vs. [O/H] has a behaviour running parallel, at higher metallicities, compared to thick disc stars, indicating that the bulge enrichment might have proceeded differently from that of the thick disc. Observations collected at the European Southern Observatory, Paranal, Chile (ESO programmes 71.B-0617A, 73.B0074A, and GTO 71.B-0196).Tables 1-6 and Figs. 1-6 are available in electronic form at http://www.aanda.org

Barbuy, B.; Hill, V.; Zoccali, M.; Minniti, D.; Renzini, A.; Ortolani, S.; Gómez, A.; Trevisan, M.; Dutra, N.

2013-11-01

380

Hydrothermal Manganese Mineralization Near the Samoan Hotspot  

NASA Astrophysics Data System (ADS)

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 erosional or mass wasting events; subsequently a thin layer of hydrogenetic Fe-Mn oxides accreted on the exposed surface. Mn-oxide filled veins may represent part of a feeder system. The thick sediment-free Mn-oxide layers locally grade into Mn-oxide cemented volcaniclastic beds. Our results indicate the extensive production of hydrothermal Mn on a regional basis, probably from multiple hydrothermal sources within the Samoan chain, and from the Tonga arc/back-arc system immediately to the west, as determined in previous studies.

Hein, J. R.; Staudigel, H.; Koppers, A.; Hart, S. R.; Dunham, R.

2006-12-01

381

Coating newly galvanized steel  

SciTech Connect

Galvanize steel may be coated to decorate the piece or to enhance the protection afforded by the galvanizing. However, these coating often fail because pretreatment and coating applications were performed as if steel, not zinc, was being coated. This article explains how galvanizing protects steel, how organic coating can protect or reinforce galvanizing, and how to pretreat and coat newly galvanized steel for optimal corrosion resistance.

Byrnes, G.

1995-10-01

382

Trends in automotive steel  

Microsoft Academic Search

For more than 100 years, steel has been basic to the automotive industry. Recently, the steel industry developed an optimized automotive steel structure that is 24% lighter, 34% stronger, and $154 less expensive than traditional auto body structures on the road today. And top executives in the auto industry and the Partnership for a New Generation of Vehicles (PNGV) cite

1996-01-01

383

Tubular steel transmission structures  

Microsoft Academic Search

This paper shows that through the use of tubular steel products, transmission lines can be built economically when comparing this product against other products such as wood, lattice steel, tapered and other formed steel poles. H-frame, single and double circuit, single pole and Y-guyed structure designs has shown that the design of the tubular structure at all transmission voltage levels

H. Heerspink

1995-01-01

384

High-Strength Steels.  

National Technical Information Service (NTIS)

Recent steel developments indicate that strength and toughness requirements for 150 ksi yield-strength steel essentially have been met, that the requirements for the 200 ksi yield-strength steel are a near-term probability, and that the requirements for t...

T. P. Groeneveld

1967-01-01

385

Comminuting irradiated ferritic steel  

SciTech Connect

Disclosed is a method of comminuting irradiated ferritic steel by placing the steel in a solution of a compound selected from the group consisting of sulfamic acid, bisulfate, and mixtures thereof. The ferritic steel is used as cladding on nuclear fuel rods or other irradiated components.

Bauer, Roger E. (Kennewick, WA); Straalsund, Jerry L. (Kennewick, WA); Chin, Bryan A. (Auburn, AL)

1985-01-01

386

Comminuting irradiated ferritic steel  

SciTech Connect

Disclosed is a method of comminuting irradiated ferritic steel by placing the steel in a solution of a compound selected from the group consisting of sulfamic acid, bisulfate, and mixtures thereof. The ferritic steel is used as cladding on nuclear fuel rods or other irradiated components.

Bauer, R. E.; Chin, B. A.; Straalsund, J. L.

1985-03-26

387

Coating newly galvanized steel  

Microsoft Academic Search

Galvanize steel may be coated to decorate the piece or to enhance the protection afforded by the galvanizing. However, these coating often fail because pretreatment and coating applications were performed as if steel, not zinc, was being coated. This article explains how galvanizing protects steel, how organic coating can protect or reinforce galvanizing, and how to pretreat and coat newly

Byrnes

1995-01-01

388

Radiocarbon dating of magnetic and non magnetic soil fractions as a method to estimate the heterotrophic component of soil respiration in a primary forest of Ghana.  

NASA Astrophysics Data System (ADS)

We estimated the heterotrophic component (Rh) of soil respiration in a primary forest of Ghana by radiocarbon dating, a method we already successfully applied in temperate and Mediterranean forests. In this case, given the advanced stage of alteration of tropical soils, which are thus rich in oxides, we implemented the method on soil fractions obtained by High Gradient Magnetic Separation (HGMS), hence based on different degrees of magnetic susceptibility. In particular, we separated an organic pool associated with magnetic minerals (e.g iron oxides) from an organic pool engaged with non-magnetic minerals. This non destructive method of fractionation, often applied to the finest fraction of soil (clay), is here attempted on the bulk fine earth (< 2 mm). We sampled the soil at 0-5, 5-15, 15-10, and 30-50 cm depth intervals, since a previous study in the same site suggested that only the first 50 cm of soil was enriched in bomb carbon (C younger than 1950). The samples of each layer were sieved at 2 mm and further at 0.5 mm ,so as to have two size fractions: 2 to 0.5 mm and <0.5 mm, and both of them were separated into a magnetic and non magnetic fraction. All the specimens were then investigated in terms of mineralogical assemblage (by X-Ray diffrattometry), chemical structure of the organic component (13C NMR spectroscopy), and 14C concentration (AMS) for inferring the mean residence time (MRT) of the organic component in the soil. Radiocarbon concentration was always higher in the finest SOC fractions (<0.5 mm), with the magnetic fraction always showing an higher 14C concentration than the non magnetic one. The magnetic and non magnetic materials of the coarser fraction (0.5-2 mm) showed quite similar 14C concentrations in all of the soil layers investigated. The composition of the organic matter is different in the different fractions and partly explains the differences in MRT, although a major role in preserving the organics from decomposition is probably played by the physical protection in aggregates. Surprisingly, the non magnetic fraction is not influenced at all by the bomb C (negative delta 14) already at a depth of 5-15 cm and, even, at 15-30 cm all the four fractions have pre-bomb C, which means relatively high radiocarbon age. The finest fractions are the main contributors to the Rh flux, particularly the magnetic fraction (<0-5 mm) which show also the higher C concentration among all fractions, opposite to the non-magnetic one that is poorer in C. The Rh flux, estimated from the mean residence time of the fractions and their C amount, allowed to get a more precise estimate with respect to a previous one performed at the same site with radiocarbon analyses on bulk soils. The Rh flux from soil is hard to be estimate based on radiocarbon analysis of the bulk soil alone, and only by means of a SOC fractionation the Rh flux can be estimated quite accurately. This alternative approach for estimating the Rh component of CO2 from soils of tropical areas is currently being applied in 10 tropical forest sites in western and central Africa in the context of the ERC Africa GHG project, and together with measurements of the C inputs annually entering the soil will allow determining the sink-source capacity of primary forest soils.

Chiti, T.; Certini, G.; Marzaioli, F.; Valentini, R.

2012-04-01

389

Short-term oral administration of several manganese compounds in mice: Physiological and behavioral alterations caused by different forms of manganese  

Microsoft Academic Search

Various compounds of manganese (Mn) are used industrially, e.g., in dyes and battery production. Manganese acetate (MnAc) salts occur in divalent and trivalent forms. Divalent MnAc is used mainly as a dye, pigment, or catalyst. The chief ingredients of Mn ore itself are manganese dioxide (Mn02) and manganese carbonate (MnC03). In Kanazawa, Japan, air pollution from a Mn treatment factory

Junko Komura; Michiko Sakamoto

1991-01-01

390

Manganese and malonate are individual regulators for the production of lignin and manganese peroxidase isozymes and in the degradation of lignin by Phlebia radiata  

Microsoft Academic Search

The effects of high manganese [180??M Mn(II)] concentration and addition of malonate (10?mM) were studied in nitrogen-limited\\u000a cultures of the white-rot fungus, Phlebia radiata. High levels of manganese alone showed no systematic influence on the production of lignin peroxidase (LiP), manganese peroxidase\\u000a (MnP) or laccase. In contrast, high-manganese containing cultures of P. radiata showed lower efficiency in the mineralization of

A. M. Moilanen; T. Lundell; T. Vares; A. Hatakka

1996-01-01

391

Role of astrocytes in manganese mediated neurotoxicity  

PubMed Central

Astrocytes are responsible for numerous aspects of metabolic support, nutrition, control of the ion and neurotransmitter environment in central nervous system (CNS). Failure by astrocytes to support essential neuronal metabolic requirements plays a fundamental role in the pathogenesis of brain injury and the ensuing neuronal death. Astrocyte-neuron interactions play a central role in brain homeostasis, in particular via neurotransmitter recycling functions. Disruption of the glutamine (Gln)/glutamate (Glu) -?-aminobutyric acid (GABA) cycle (GGC) between astrocytes and neurons contributes to changes in Glu-ergic and/or GABA-ergic transmission, and is associated with several neuropathological conditions, including manganese (Mn) toxicity. In this review, we discuss recent advances in support of the important roles for astrocytes in normal as well as neuropathological conditions primarily those caused by exposure to Mn.

2013-01-01

392

Impaired Manganese Metabolism Causes Mitotic Misregulation*  

PubMed Central

Manganese is an essential trace element, whose intracellular levels need to be carefully regulated. Mn2+ acts as a cofactor for many enzymes and excess of Mn2+ is toxic. Alterations in Mn2+ homeostasis affect metabolic functions and mutations in the human Mn2+/Ca2+ transporter ATP2C1 have been linked to Hailey-Hailey disease. By deletion of the yeast orthologue PMR1 we have studied the impact of Mn2+ on cell cycle progression and show that an excess of cytosolic Mn2+ alters S-phase transit, induces transcriptional up-regulation of cell cycle regulators, bypasses the need for S-phase cell cycle checkpoints and predisposes to genomic instability. On the other hand, we find that depletion of the Golgi Mn2+ pool requires a functional morphology checkpoint to avoid the formation of polyploid cells.

Garcia-Rodriguez, Nestor; Diaz de la Loza, Maria del Carmen; Andreson, Bethany; Monje-Casas, Fernando; Rothstein, Rodney; Wellinger, Ralf Erik

2012-01-01

393

Studies on Indian Ocean Manganese Nodules  

PubMed

A series of strontium-lanthanum oxide mixed manganese nodules were prepared and characterized by X-ray diffraction, nitrogen adsorption-desorption, electrical conductivity, and surface excess oxygen. X-ray diffraction patterns confirm the formation of perovskite-type oxides at low strontium content (x

Parida; Sahoo; Das

1997-03-15

394

Structural stability of lithium manganese oxides  

NASA Astrophysics Data System (ADS)

We have studied stability of lithium-manganese oxides using density functional theory in the local density and generalized gradient approximation (GGA). In particular, the effect of spin-polarization and magnetic ordering on the relative stability of various structures is investigated. At all lithium compositions the effect of spin polarization is large, although it does not affect different structures to the same extent. At composition LiMnO2, globally stable Jahn-Teller distortions could only be obtained in the spin-polarized GGA approximation, and antiferromagnetic spin ordering was critical to reproduce the orthorhombic LiMnO2 structure as ground state. We also investigate the effect of magnetism on the Li intercalation potential, an important property for rechargeable Li batteries.

Mishra, S. K.; Ceder, G.

1999-03-01

395

Realization of insulating massive Dirac fermion state in Bi2Te3 by co-substitution of magnetic and non-magnetic elements  

NASA Astrophysics Data System (ADS)

The insulating massive Dirac fermion state is essential for many striking topological phenomena. Here, we theoretically reveal that co-substitution of magnetic and non-magnetic elements is a promising way to realize it, and Fe is the best candidate to achieve it in Bi2Te3 among M (M = Ti, V, Cr, Mn, and Fe). Substitution of M for Bi introduces perpendicular magnetism, but some energy bands cross the Fermi level. Furthermore, the synergistic effect of Fe and O places the Dirac point inside the bulk band gap and opens a surface band gap at the Dirac point with the Fermi level inside it.

Niu, Chengwang; Dai, Ying; Yu, Lin; Huang, Baibiao

2013-03-01

396

Comparative Methylation Chemistry of Platinum, Palladium, Lead, and Manganese.  

National Technical Information Service (NTIS)

A study was carried out to evaluate the potential for platinum, palladium, lead, and manganese salts and oxides to be biochemically methylated. Methylation is an important, well recognized, determinant of metal toxicity; the striking example being the ext...

R. T. Taylor

1976-01-01

397

Hot coal gas desulfurization with manganese-based sorbents.  

National Technical Information Service (NTIS)

The focus of work being performed on Hot Coal Gas Desulfurization at the Morgantown Energy Technology Center is primarily in the use of zinc ferrite and zinc titanate sorbents; however, prior studies indicated that an alternate sorbent, manganese dioxide-...

M. T. Hepworth R. Ben-Slimane

1994-01-01

398

Reactions with Manganese by Bacteria from Marine Ferromanganese Nodules.  

National Technical Information Service (NTIS)

Previous reports by the author revealed an intimate association of several bacterial species with manganese nodules from the Atlantic Ocean. It was demonstrated by selective enrichment and with pure-culture isolates that some of the bacteria from nodules ...

H. L. Ehrlich

1966-01-01

399

Solution synthesis and characterization of lithium manganese oxide cathode materials.  

National Technical Information Service (NTIS)

A nonaqueous coprecipitation process has been developed to prepare controlled stoichiometry lithium manganese oxalate precipitates. The process involved mixing a methanolic Li-Mn nitrate solution with a methanolic solution containing tetramethylammonium o...

J. A. Voigt T. J. Boyle D. H. Doughty

1995-01-01

400

An analysis for blood manganese used to assess environmental exposure.  

PubMed

In this graphite-furnace atomic-absorption spectrometric method for measuring manganese in whole blood, we use a pyrolytic platform to minimize interference by sample matrix. For optimal sample ashing we denature the sample within the furnace with nitric acid and use oxygen as the purge gas at low temperatures. The mean manganese concentration found in blood from 15 unexposed city dwellers was 215 (2 SD 135) nmol/L. By comparison, the range of manganese concentrations in blood sampled from a group of Australian aborigines living near a surface manganese ore deposit on Groote Eylandt, Northern Territory, was much higher (median 405 nmol/L, range 175 to 990 nmol/L). PMID:3378331

Hams, G A; Fabri, J K

1988-06-01

401

A comparative evaluation of cobalt chromium oxide, cobalt manganese oxide, cobalt manganese oxide, and copper manganese oxide as catalysts for the water-gas shift reaction  

SciTech Connect

Cobalt chromium oxide, cobalt manganese oxide, and copper manganese oxide have been compared as catalysts for the water-gas shift reaction. Cobalt chromium oxide and cobalt manganese oxide catalysts can give both high activity and long lifetimes for this reaction. Cobalt chromium oxide catalysts display higher activity compared to the other catalyst systems and this is shown that both the cobalt chromium oxide and the cobalt manganese oxide catalysts are not sensitive to the presence of up to 240 ppm feedstock sulphur impurities (H{sub 2}S and COS) and high catalyst activity can be maintained either in the presence or in the absence of feedstock sulphur. The copper manganese oxide catalysts are demonstrated to be particularly sensitive to feedstock sulphur, being significantly poisoned at levels as low as 1 ppm H{sub 2}S. An investigation of the mechanism of the water-gas shift mechanism over the three catalyst systems is also described using both kinetic and model reagent studies. Based on these studies, a mechanism is proposed for the cobalt- and copper-containing catalyst systems involving the formation of a surface formate intermediate.

Hutchings, G.J. (Univ. of Liverpool (United Kingdom)); Copperthwaite, R.G.; Gottschalk, F.M.; Hunter, R.; Mellor, J.; Orchard, S.W.; Sangiorgio, T. (Univ. of the Witwatersrand, Johannesburg (South Africa))

1992-10-01

402

Oxidations of bifunctional substrates with soluble manganese(IV) phosphate  

Microsoft Academic Search

Water-soluble manganese(IV) phosphate which is capable of auto-catalytic oxidation of compounds containing two functional groups, was prepared in 3 M phosphoric acid. The reaction was studied with an ethylene glycol-glycollic aldehyde-glycollic acid-glyoxylic a acid sequence of compounds, and a reaction mechanism is proposed. The autocatalytic effect is due to manganese(III), which is in itself much less reactive to these substrates.

Miklós Jáky

1995-01-01

403

Oxidation kinetics of manganese (II) in seawater at nanomolar concentrations  

Microsoft Academic Search

Manganese oxidation rates were determined at low (? 20 nM) concentrations in seawater by measuring dissolved manganese (Mn(II)) using flow injection analysis with chemiluminescence detection. Mn(II) was measured in samples that had been filtered (0.2 ?m) and kept in the dark under controlled temperature and pH conditions for time periods up to 6 months. Eight 9 L carboys with mean

Peter J. von Langen; Kenneth S. Johnson; Kenneth H. Coale; Virginia A. Elrod

1997-01-01

404

Oxidative coupling of methane over natural manganese oxide  

Microsoft Academic Search

Oxydehydrogenative coupling of methane to higher hydrocarbons has been achieved with high selectivity towards C2 products over natural mineral manganese oxides. Oxide treatments under hydrocarbon atmosphere show that the reduction of manganese ions Mn(IV), Mn(III) to Mn(II) is mainly responsible for the catalyst deactivation. The tests using CH4 + CD4 equimolecular mixtures and the analysis of the (HD)C2 products by

L. M. Ioffe; T. Lopez; Y. G. Borodko; R. Gomez

1995-01-01

405

Manganese exposure: Neuropsychological and neurological symptoms and effects in welders  

Microsoft Academic Search

Manganese exposure reportedly may have an adverse effect on CNS function and mood. Sixty-two welders with clinical histories of exposure to manganese were compared to 46 matched regional controls chosen at random from a telephone directory. The following tests were given: Wechsler Adult Intelligence Scale (WAIS-III), Wechsler Memory Scale (WMS-III), Boston Naming, WRAT-3, Cancellation H, Trail Making Tests A and

Rosemarie M. Bowler; Sabine Gysens; Emily Diamond; Sanae Nakagawa; Marija Drezgic; Harry A. Roels

2006-01-01

406

Electrochemical supercapacitor material based on manganese oxide: preparation and characterization  

Microsoft Academic Search

A novel class of electrochemical supercapacitor electrode material has been electrochemically synthesized from a manganese halide complex in water-containing acetonitrile electrolyte at room temperature. This material has been physically and chemically characterized by scanning electron microscopy, X-ray photoelectron microscopy (XPS), FT-Raman microscopy and cyclic voltammetry. XPS and FT-Raman characterization suggest that this material is composed of manganese oxide with a

Junhua Jiang; Anthony Kucernak

2002-01-01

407

Chronic manganese poisoning in the dry battery industry  

Microsoft Academic Search

Emara, A. M., El-Ghawabi, S. H., Madkour, O. I., and El-Samra, G. H. (1971). Brit. J. industr. Med., 28, 78-82. Chronic manganese poisoning in the dry battery industry. A survey was carried out on 36 workers in the dry battery industry exposed to dust containing 65 to 70% manganese oxide. Eight (22·2%) were found to have neuropsychiatric manifestations, six (16·6%)

A. M. Emara; S. H. El-Ghawabi; O. I. Madkour; G. H. El-Samra

1971-01-01

408

Acute exposure of laboratory mice to manganese oxide.  

PubMed

An acute inhalation exposure of laboratory mice to respirable Mn3O4 aerosols is described. The generation system consisted of a Wright dust generator which produced 1.40 micrometer aerosols. A non-linear loss of deposited manganese from mouse lungs over the inital 24-hour post-exposure period was observed. Systemic distribution of the manganese was observed in various tissues following exposure. PMID:7415970

Adkins, B; Luginbuhl, G H; Gardner, D E

1980-07-01

409

Manganese oxidation state mediates toxicity in PC12 cells  

Microsoft Academic Search

The role of the manganese (Mn) oxidation state on cellular Mn uptake and toxicity is not well understood. Therefore, undifferentiated PC12 cells were exposed to 0–200 ?M Mn(II)–chloride or Mn(III)–pyrophosphate for 24 h, after which cellular manganese levels were measured along with measures of cell viability, function, and cytotoxicity (trypan blue exclusion, medium lactate dehydrogenase (LDH), 8-isoprostanes, cellular ATP, dopamine,

S. H.. Reaney; D. R. Smith

2005-01-01

410

Manganese Metabolism in College Men Consuming Vegetarian Diets  

Microsoft Academic Search

Manganese balance was studied in eight college men consuming a vegetarian diet low in protein. The diet was supplemented with either a vegetable protein food or the vegetable protein food plus skim milk powder. The values for total mean daily manganese intake, excretion and retention were 7.07, 3.74 and 3.34 mg, respectively. The mean daily intake, excretion and retention for

VIRGINIA M. LANG; BARBARA B. NORTH; M. MORSfc

411

The Molecular Geomicrobiology of Bacterial Manganese(II) Oxidation  

Microsoft Academic Search

\\u000a Manganese is the second most abundant transition metal found in the Earth’s crust. It has a significant biological role as\\u000a it is a cofactor of enzymes such as superoxide dismutase and is the key metal in the reaction center of photosystem II. In\\u000a the environment, manganese is mostly found in three different oxidation states: II, III, and IV. Mn(II), primarily

Bradley M. Tebo; Kati Geszvain; Sung-Woo Lee

412

The thermal stability of lithium-manganese-oxide spinel phases  

Microsoft Academic Search

The thermal stability of stoichiometric spinel phases in the system Li1+?Mn2-?O4 (0 ? ? ? 0.33) has been investigated by high-temperature powder X-ray diffraction, differential thermal analysis, and thermogravimetric analysis. At elevated temperatures, the lithium-manganese-oxide spinels undergo phase changes by loss of oxygen and lithia (Li2O). The data highlight the importance of temperature control when synthesising lithium-manganese-oxide spinel compounds.

M. M. Thackeray; M. F. Mansuetto; D. W. Dees; D. R. Vissers

1996-01-01

413

Solution synthesis and characterization of lithium manganese oxide cathode materials  

Microsoft Academic Search

A nonaqueous coprecipitation process has been developed to prepare controlled stoichiometry lithium manganese oxalate precipitates. The process involved mixing a methanolic Li-Mn nitrate solution with a methanolic solution containing tetramethylammonium oxalate as the precipitating agent. The resulting oxalates were readily converted to a variety of phase pure lithium manganese oxides at moderate temperatures (â¤600°C), where the phase formed was determined

J. A. Voigt; T. J. Boyle; D. H. Doughty

1995-01-01

414

A study of layered lithium manganese oxide cathode materials  

Microsoft Academic Search

Substituted layered sodium manganese oxide bronzes with the P2 structure were prepared by glycine-nitrate combustion synthesis. The Na in the as-prepared materials could be completely ion-exchanged for Li under mild conditions. All lithium manganese oxide compounds obtained after ion-exchange have O2 stacking of the layers. Cyclic voltammetry and stepped potential experiments on lithium cells containing these materials show that the

Tom A Eriksson; Marca M Doeff

2003-01-01

415

Lithium Isotope Selectivity of Sorbents Prepared from Lithium Manganese Oxides  

Microsoft Academic Search

Sorbents are prepared by extracting lithium ions from lithium manganese oxides with the lithium\\/manganese mole ratio (Li\\/Mn ratio) varying between 0.42 and 0.84, and their lithium isotope selectivities are investigated. All the sorbents are Li-specific and the values of the Li-to-Li isotopic separation factor (S) are between 1.0040 and 1.0092 at 25°C. The S value is slightly dependent on the

HIROTSUGU TAKEUCHI; TAKAO OI; MORIKAZU HOSOE

1999-01-01

416

Laser microstructuring and annealing processes for lithium manganese oxide cathodes  

Microsoft Academic Search

It is expected that cathodes for lithium-ion batteries (LIB) composed out of nano-composite materials lead to an increase in power density of the LIB due to large electrochemically active surface areas but cathodes made of lithium manganese oxides (Li–Mn–O) suffer from structural instabilities due to their sensitivity to the average manganese oxidation state. Therefore, thin films in the Li–Mn–O system

J. Pröll; R. Kohler; M. Torge; S. Ulrich; C. Ziebert; M. Bruns; H. J. Seifert; W. Pfleging

2011-01-01

417

Spinel lithium manganese oxide synthesized under a pressurized oxygen atmosphere  

Microsoft Academic Search

Spinel lithium manganese oxide was synthesized via co-precipitation. The prepared lithium manganese oxide powder was further heated at 700°C for 15h under pressurized (3bar) oxygen atmosphere. The resultant exhibited a highly crystalline cubic spinel phase with space group Fd3m, as confirmed by X-ray diffraction. The spinel compound exhibited a slightly smaller lattice constant than a conventional spinel compound, even though

Ki-Soo Lee; Seung-Taek Myung; Hun-Gi Jung; Jung Kyoo Lee; Yang-Kook Sun

2010-01-01

418

Manganese detection in marine sediments: anodic vs. cathodic stripping voltammetry  

Microsoft Academic Search

Three different electroanalytical techniques for the detection of manganese in marine sediments are evaluated. The anodic stripping voltammetry of manganese at an in situ bismuth-film-modified boron-doped diamond electrode and cathodic stripping voltammetry at a carbon paste electrode are shown to lack the required sensitivity and reproducibility whereas cathodic stripping voltammetry at a bare boron-doped diamond electrode is shown to be

Craig E. Banks; Jaanus Kruusma; Ryan R. Moore; Peter Tom?ík; Judith Peters; James Davis; Šebojka Komorsky-Lovri?; Richard G. Compton

2005-01-01

419

Toxicity of Manganese to Ceriodaphnia dubia and Hyalella azteca  

Microsoft Academic Search

.   Manganese is a toxic element frequently overlooked when assessing toxicity of effluents, sediments, and pore waters. Manganese\\u000a can be present at toxic levels in anoxic solutions due to increased solubility under chemically reducing conditions, and it\\u000a can remain at those levels for days in aerated test waters due to slow precipitation kinetics. Ceriodaphnia dubia and Hyalella azteca are freshwater

P. J. Lasier; P. V. Winger; K. J. Bogenrieder

2000-01-01

420

Mineralogical Characterization of Manganese Oxides in Mine Water Treatment Systems  

NASA Astrophysics Data System (ADS)

The removal of manganese(II) from mine water is a significant problem for both operating and abandoned mines across the United States. In many situations, manganese removal represents the most costly aspect of mine water treatment. Active treatment of Mn-containing mine water requires adjustment of pH to 9-10, and results in the abiotic precipitation of manganese oxides (MnOx). After manganese removal, this high pH water must be neutralized before release. Alternatively, passive limestone beds can be used for neutralization of low-pH mine water and subsequent manganese removal. Although limestone beds are effective for Mn removal, the processes involved are not clear (e.g., relative importance of biological Mn(II) oxidation versus surface mediated oxidation) and the characteristics of the manganese "crusts" formed are not well studied. In this field-based study, we have collected natural manganese oxides from two different limestone beds designed to treat mine water from abandoned coal strip mines in Pennsylvania. Samples were collected at different locations in the beds and at different seasons to capture possible variations in mineralogical characteristics. Water samples were also collected to measure the corresponding solution chemistry and revealed that manganese removal was strongly temperature dependent. Solid samples have been examined by scanning and transmission electron microscopy, and by X-ray diffraction. Micro-diffraction XRD has been used to tentatively identify disordered buserite as a predominant mineral in many of these crust samples. Additional characterizations will include particle size distribution and surface charge. Synchroton-based X-ray techniques such as scanning transmission X-ray microscopy (STXM) and X-ray spectroscopy (XAS) may also be pursued.

Tan, H.; Heaney, P.; Post, J.; Burgos, W.

2006-05-01

421

The steel scrap age.  

PubMed

Steel production accounts for 25% of industrial carbon emissions. Long-term forecasts of steel demand and scrap supply are needed to develop strategies for how the steel industry could respond to industrialization and urbanization in the developing world while simultaneously reducing its environmental impact, and in particular, its carbon footprint. We developed a dynamic stock model to estimate future final demand for steel and the available scrap for 10 world regions. Based on evidence from developed countries, we assumed that per capita in-use stocks will saturate eventually. We determined the response of the entire steel cycle to stock saturation, in particular the future split between primary and secondary steel production. During the 21st century, steel demand may peak in the developed world, China, the Middle East, Latin America, and India. As China completes its industrialization, global primary steel production may peak between 2020 and 2030 and decline thereafter. We developed a capacity model to show how extensive trade of finished steel could prolong the lifetime of the Chinese steelmaking assets. Secondary steel production will more than double by 2050, and it may surpass primary production between 2050 and 2060: the late 21st century can become the steel scrap age. PMID:23442209

Pauliuk, Stefan; Milford, Rachel L; Müller, Daniel B; Allwood, Julian M

2013-03-07

422

Measurement of grain boundary composition for X52 pipeline steel  

SciTech Connect

Analytical electron microscopy was used to measure the composition of grain boundaries (GBs) and interconstituent boundaries (IBs) of X52 pipeline steel using specimens about 40--60 nm in thickness. All elements of interest were examined with the exception of carbon. With this caveat, there was no segregation at proeutectoid ferrite GBs. This indicated that the commonly expected species S and P are not responsible for preferential corrosion of GBs during intergranular stress corrosion cracking of pipeline steels. Manganese was the only species measured to segregate at the IBs. Manganese segregated to the IBs between proeutectoid ferrite and pearlitic cementite, and desegregated from IBs between proeutectoid ferrite and pearlitic ferrite. The pearlitic cementite was Mn rich. There was no Mn segregation at the IBs between pearlitic ferrite and pearlitic cementite. The pattern of Mn segregation could be explained in terms of diffusion in the process zone ahead of the pearlite during the austenite to pearlite transformation and diffusion in the IBs between the proeutectoid ferrite and pearlite.

Wang, J.Q. [Univ. of Queensland, Brisbane, Queensland (Australia). Dept. of Mining, Minerals and Materials Engineering]|[Chinese Academy of Sciences, Shenyang (China). State Key Lab. of Corrosion Science; Atrens, A.; Cousens, D.R.; Kelly, P.M. [Univ. of Queensland, Brisbane, Queensland (Australia). Dept. of Mining, Minerals and Materials Engineering; Nockolds, C.; Bulcock, S. [Univ. of Sydney, New South Wales (Australia). Electron Microscopy Unit

1998-10-09

423

Manganese micro-nodules on ancient brick walls.  

PubMed

Romans, Jews, Arabs and Christians built the ancient city of Toledo (Spain) with bricks as the main construction material. Manganese micro-nodules (circa 2 microm in diameter) have grown under the external bio-film surface of the bricks. Recent anthropogenic activities such as industrial emissions, foundries, or traffic and housing pollution have further altered these old bricks. The energy-dispersive X-ray microanalyses (XPS) of micro-nodules show Al, Si, Ca, K, Fe and Mn, with some carbon species. Manganese atoms are present only as Mn(4+) and iron as Fe(3+) (FeOOH-Fe(2)O(3) mixtures). The large concentration of alga biomass of the River Tagus and the Torcón and Guajaraz reservoirs suggest manganese micro-nodules are formed either from water solutions rich in anthropogenic MnO(4)K in a reduction environment (from Mn(7+) to Mn(4+)) or by oxidation mechanisms from dissolved Mn(2+) (from Mn(2+) to Mn(4+)) linked to algae biofilm onto the ancient brick surfaces. Ancient wall surfaces were also studied by scanning electron microscopy (SEM-EDS) and X-ray diffraction (XRD). Chemical and biological analyses of the waters around Toledo are also analysed for possible sources of manganese. Manganese micro-nodules on ancient brick walls are good indicators of manganese pollution. PMID:12526915

López-Arce, P; García-Guinea, J; Fierro, J L G

2003-01-20

424

Low copper and high manganese levels in prion protein plaques  

USGS Publications Warehouse

Accumulation of aggregates rich in an abnormally folded form of the prion protein characterize the neurodegeneration caused by transmissible spongiform encephalopathies (TSEs). The molecular triggers of plaque formation and neurodegeneration remain unknown, but analyses of TSE-infected brain homogenates and preparations enriched for abnormal prion protein suggest that reduced levels of copper and increased levels of manganese are associated with disease. The objectives of this study were to: (1) assess copper and manganese levels in healthy and TSE-infected Syrian hamster brain homogenates; (2) determine if the distribution of these metals can be mapped in TSE-infected brain tissue using X-ray photoelectron emission microscopy (X-PEEM) with synchrotron radiation; and (3) use X-PEEM to assess the relative amounts of copper and manganese in prion plaques in situ. In agreement with studies of other TSEs and species, we found reduced brain levels of copper and increased levels of manganese associated with disease in our hamster model. We also found that the in situ levels of these metals in brainstem were sufficient to image by X-PEEM. Using immunolabeled prion plaques in directly adjacent tissue sections to identify regions to image by X-PEEM, we found a statistically significant relationship of copper-manganese dysregulation in prion plaques: copper was depleted whereas manganese was enriched. These data provide evidence for prion plaques altering local transition metal distribution in the TSE-infected central nervous system.

Johnson, Christopher J.; Gilbert, PUPA; Abrecth, Mike; Baldwin, Katherine L.; Russell, Robin E.; Pedersen, Joel A.; McKenzie, Debbie

2013-01-01

425

Low Copper and High Manganese Levels in Prion Protein Plaques  

PubMed Central

Accumulation of aggregates rich in an abnormally folded form of the prion protein characterize the neurodegeneration caused by transmissible spongiform encephalopathies (TSEs). The molecular triggers of plaque formation and neurodegeneration remain unknown, but analyses of TSE-infected brain homogenates and preparations enriched for abnormal prion protein suggest that reduced levels of copper and increased levels of manganese are associated with disease. The objectives of this study were to: (1) assess copper and manganese levels in healthy and TSE-infected Syrian hamster brain homogenates; (2) determine if the distribution of these metals can be mapped in TSE-infected brain tissue using X-ray photoelectron emission microscopy (X-PEEM) with synchrotron radiation; and (3) use X-PEEM to assess the relative amounts of copper and manganese in prion plaques in situ. In agreement with studies of other TSEs and species, we found reduced brain levels of copper and increased levels of manganese associated with disease in our hamster model. We also found that the in situ levels of these metals in brainstem were sufficient to image by X-PEEM. Using immunolabeled prion plaques in directly adjacent tissue sections to identify regions to image by X-PEEM, we found a statistically significant relationship of copper-manganese dysregulation in prion plaques: copper was depleted whereas manganese was enriched. These data provide evidence for prion plaques altering local transition metal distribution in the TSE-infected central nervous system.

Johnson, Christopher J.; Gilbert, P.U.P.A.; Abrecht, Mike; Baldwin, Katherine L.; Russell, Robin E.; Pedersen, Joel A.; Aiken, Judd M.; McKenzie, Debbie

2013-01-01

426

Chronic manganese poisoning in the dry battery industry  

PubMed Central

Emara, A. M., El-Ghawabi, S. H., Madkour, O. I., and El-Samra, G. H. (1971). Brit. J. industr. Med., 28, 78-82. Chronic manganese poisoning in the dry battery industry. A survey was carried out on 36 workers in the dry battery industry exposed to dust containing 65 to 70% manganese oxide. Eight (22·2%) were found to have neuropsychiatric manifestations, six (16·6%) had chronic manganese psychosis, one had left hemi-parkinsonism, and one had left choreoathetosis. An environmental study revealed a high concentration of manganese dust at the main working areas, far exceeding the accepted MAC. The manganese level in blood was almost within the normal range. Coproporphyrin in urine was normal. The electroencephalogram was abnormal in only two of the affected workers (25%) but there was no association between this and the clinical manifestations or duration of exposure. The concentration of manganese dust in air showed some association with the prevalence and rapidity of effect on workers according to their occupation. However, individual susceptibility was apparent. The shortest latent period was one year.

Emara, A. M.; El-Ghawabi, S. H.; Madkour, O. I.; El-Samra, G. H.

1971-01-01

427

40 CFR 721.10253 - Butanedioic acid, 2-methylene-, polymer with 2,5 furanedione, copper(2+) manganese(2+) sodium...  

Code of Federal Regulations, 2013 CFR

...manganese(2+) sodium zinc salt, hydrogen peroxide-initiated. 721.10253...manganese(2+) sodium zinc salt, hydrogen peroxide-initiated. (a) Chemical...manganese(2+) sodium zinc salt, hydrogen peroxide-initiated (PMN...

2013-07-01

428

Bioaccumulation of manganese and its toxicity in feral pigeons (Columba livia) exposed to manganese oxide dust (Mn3O4).  

PubMed

Manganese tetroxide (Mn3O4) 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 Mn3O4 have been reported. The present study was therefore conducted to examine the bioaccumulation and toxicity of manganese in various organs of feral pigeons (Columba livia) when exposed to low levels of Mn3O4 via inhalation and hence to find any possible relationship between these two parameters. A total of 22 pigeons was exposed to 239 micrograms/m3 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, alanine aminotransferase, total iron, blood urea nitrogen and triglycerides, were also measured. Manganese concentrations in brain, lung, and bone were significantly higher in Mn3O4-exposed pigeons (0.59, 0.58, and 3.02 micrograms wet tissue, respectively) than in the control group (0.46, 0.19, 1.74 micrograms/g wet tissue, respectively). However, except for total proteins such exposure did not produce any changes in various biochemical parameters which were within the normal values. Thus these results have shown that, despite significant bioaccumulation of manganese in some tissues, no significant toxic effects could be seen. PMID:9841807

Sierra, P; Chakrabarti, S; Tounkara, R; Loranger, S; Kennedy, G; Zayed, J

1998-11-01

429

Improvement of lithium-containing manganese dioxide (composite dimensional manganese oxide: CDMO) as positive material for lithium secondary batteries  

Microsoft Academic Search

The paper describes the development of an improved lithium-containing manganese dioxide (composite dimensional manganese oxide, CDMO) as a positive material for lithium secondary batteries with high discharge voltage and capacity. It was found that CDMO charged to a high potential (i.e., 3.6 V compared with normal charge 3.3. V) exhibited a higher discharge voltage and a greater capacity. The optimum

T. Nohma; Y. Yamamoto; I. Nakane; N. Furukawa

1992-01-01

430

Comparison of manganese oxide nanoparticles and manganese sulfate with regard to oxidative stress, uptake and apoptosis in alveolar epithelial cells  

Microsoft Academic Search

Due to their physicochemical characteristics, metal oxide nanoparticles (NPs) interact differently with cells compared to larger particles or soluble metals. Oxidative stress and cellular metal uptake were quantified in rat type II alveolar epithelial cells in culture exposed to three different NPs: manganese(II,III) oxide nanoparticles (Mn3O4-NPs), the soluble manganese sulfate (Mn-salt) at corresponding equivalent doses, titanium dioxide (TiO2-NPs) and cerium

Ramon Frick; Björn Müller-Edenborn; Andreas Schlicker; Barbara Rothen-Rutishauser; David O. Raemy; Detlef Günther; Bodo Hattendorf; Wendelin Stark; Beatrice Beck-Schimmer

2011-01-01

431

Varying Levels of Manganese and Iron Affect Absorption and Gut Endogenous Losses of Manganese by Rats1  

Microsoft Academic Search

The interactive effects of manganese and iron on true absorption and endogenous losses of man ganese were investigated by feeding rats three levels of manganese (0.9, 48 or 188 ug Mn\\/g diet) and two levels of iron (19 or 276 ug Fe\\/a diet) for 7 wk. After 45 d, half of the rats were fed •'^Mn and half were injected

CINDY D. DAVIS; TERRY L WOLF; ANDJ. L GREGER

432

Magnetism and electronic structure of binuclear manganese complexes in ortho-quinone ligand and polymer environments  

NASA Astrophysics Data System (ADS)

By means of mechanochemical synthesis we obtained a coordination polymer containing binuclear manganese complexes with organic catechol/ortho-quinone ligands. The reaction system contained polystyrene, manganese acetylacetonate, and donor-acceptor mixture catechol/ortho-quinone. Electron paramagnetic resonance (EPR) and infrared spectroscopic data show that the binuclear manganese complex is covalently linked to the chain of polystyrene. Theoretical EPR spectrum analysis revealed a triplet state of the complex with two nonequivalent manganese ions coupled to each other by spin exchange. The type of magnetic coupling between manganese ions in this system is similar to the one in manganese based inorganic magnetic materials.

Rakhimov, R. R.; Arrington, S. A.; Hwang, J. S.; Prokof'ev, A. I.; Alexandrov, I. A.; Aleksandrov, A. I.

2006-04-01

433

Steel penetration in sand molds. Final technical report, September 1994--September 1997  

SciTech Connect

The research program was successful in identifying the major factoirs that influence penetration. This was done first through a case study of penetration samples. The study revealed that both chemical and mechanical penetration were present in carbon and high manganese steels. It also found that only mechanical penetration is found in stainless steel samples. It should be noted that when mechanical penetration does occur, there is a greater risk of chemical reactions with the mold. Therefore, it is common to confuse mechanical penetration with chemical. Sessile drop experiments were run to discover the effect of steel chemistry on the contact angle for different substrates. These experiments revealed the best substrates for each type of metal. Bauxite, magnesite, and mullite were discovered to be the best materials for resisting mechanical penetration. It was also shown that high manganese steels cannot be poured into silica molds and that stainless steel should not be poured in chromite molds. The sessile drop data was used to develop a mechanical penetration model which correctly predicted penetration in sixteen of twenty castings poured at the University of Alabama. Mold/metal atmosphere tests were run to understand the effects of the atmosphere on chemical penetration. It was found that the chemistry affecting penetration has its greatest effect as the casting is just poured. Chemical penetration for low carbon steels cannot be completely eliminated by adding carbon (seacoal) to green sand molds although a marked decrease is obtained in its severity. Extremely high carbon concentrations might be able to totally eliminate the penetration but are not used because of their possible diffusion into the steel causing carburization. A chemical penetration model was produced and its results agree well with the experimental results.

Hayes, K.D.; Owens, M.; Barlow, J.; Stefanescu, D.M.; Lane, A.M.; Piwonka, T.S.

1997-12-01

434

Six-coordinate manganese(3+) in catalysis by yeast manganese superoxide dismutase  

PubMed Central

Reduction of superoxide () by manganese-containing superoxide dismutase occurs through either a “prompt protonation” pathway, or an “inner-sphere” pathway, with the latter leading to formation of an observable Mn-peroxo complex. We recently reported that wild-type (WT) manganese superoxide dismutases (MnSODs) from Saccharomyces cerevisiae and Candida albicans are more gated toward the “prompt protonation” pathway than human and bacterial MnSODs and suggested that this could result from small structural changes in the second coordination sphere of manganese. We report here that substitution of a second-sphere residue, Tyr34, by phenylalanine (Y34F) causes the MnSOD from S. cerevisiae to react exclusively through the “inner-sphere” pathway. At neutral pH, we have a surprising observation that protonation of the Mn-peroxo complex in the mutant yeast enzyme occurs through a fast pathway, leading to a putative six-coordinate Mn3+ species, which actively oxidizes in the catalytic cycle. Upon increasing pH, the fast pathway is gradually replaced by a slow proton-transfer pathway, leading to the well-characterized five-coordinate Mn3+. We here propose and compare two hypothetical mechanisms for the mutant yeast enzyme, differing in the structure of the Mn-peroxo complex yet both involving formation of the active six-coordinate Mn3+ and proton transfer from a second-sphere water molecule, which has substituted for the ?OH of Tyr34, to the Mn-peroxo complex. Because WT and the mutant yeast MnSOD both rest in the 2+ state and become six-coordinate when oxidized up from Mn2+, six-coordinate Mn3+ species could also actively function in the mechanism of WT yeast MnSODs.

Sheng, Yuewei; Butler Gralla, Edith; Schumacher, Mikhail; Cascio, Duilio; Cabelli, Diane E.; Selverstone Valentine, Joan

2012-01-01

435

Six-coordinate manganese(3+) in catalysis by yeast manganese superoxide dismutase.  

PubMed

Reduction of superoxide (O2-) by manganese-containing superoxide dismutase occurs through either a "prompt protonation" pathway, or an "inner-sphere" pathway, with the latter leading to formation of an observable Mn-peroxo complex. We recently reported that wild-type (WT) manganese superoxide dismutases (MnSODs) from Saccharomyces cerevisiae and Candida albicans are more gated toward the "prompt protonation" pathway than human and bacterial MnSODs and suggested that this could result from small structural changes in the second coordination sphere of manganese. We report here that substitution of a second-sphere residue, Tyr34, by phenylalanine (Y34F) causes the MnSOD from S. cerevisiae to react exclusively through the "inner-sphere" pathway. At neutral pH, we have a surprising observation that protonation of the Mn-peroxo complex in the mutant yeast enzyme occurs through a fast pathway, leading to a putative six-coordinate Mn(3+) species, which actively oxidizes O2- in the catalytic cycle. Upon increasing pH, the fast pathway is gradually replaced by a slow proton-transfer pathway, leading to the well-characterized five-coordinate Mn(3+). We here propose and compare two hypothetical mechanisms for the mutant yeast enzyme, differing in the structure of the Mn-peroxo complex yet both involving formation of the active six-coordinate Mn(3+) and proton transfer from a second-sphere water molecule, which has substituted for the -OH of Tyr34, to the Mn-peroxo complex. Because WT and the mutant yeast MnSOD both rest in the 2+ state and become six-coordinate when oxidized up from Mn(2+), six-coordinate Mn(3+) species could also actively function in the mechanism of WT yeast MnSODs. PMID:22908245

Sheng, Yuewei; Butler Gralla, Edith; Schumacher, Mikhail; Cascio, Duilio; Cabelli, Diane E; Valentine, Joan Selverstone

2012-08-20

436

Six-coordinate manganese(3+) in catalysis by yeast manganese superoxide dismutase  

SciTech Connect

Reduction of superoxide (O{sub 2}{sup -}) by manganese-containing superoxide dismutase occurs through either a 'prompt protonation' pathway, or an 'inner-sphere' pathway, with the latter leading to formation of an observable Mn-peroxo complex. We recently reported that wild-type (WT) manganese superoxide dismutases (MnSODs) from Saccharomyces cerevisiae and Candida albicans are more gated toward the 'prompt protonation' pathway than human and bacterial MnSODs and suggested that this could result from small structural changes in the second coordination sphere of manganese. We report here that substitution of a second-sphere residue, Tyr34, by phenylalanine (Y34F) causes the MnSOD from S. cerevisiae to react exclusively through the 'inner-sphere' pathway. At neutral pH, we have a surprising observation that protonation of the Mn-peroxo complex in the mutant yeast enzyme occurs through a fast pathway, leading to a putative six-coordinate Mn3+ species, which actively oxidizes O{sub 2}{sup -} in the catalytic cycle. Upon increasing pH, the fast pathway is gradually replaced by a slow proton-transfer pathway, leading to the well-characterized five-coordinate Mn{sup 3+}. We here propose and compare two hypothetical mechanisms for the mutant yeast enzyme, diffeeing in the structure of the Mn-peroxo complex yet both involving formation of the active six-coordinate Mn{sup 3+} and proton transfer from a second-sphere water molecule, which has substituted for the -OH of Tyr34, to the Mn-peroxo complex. Because WT and the mutant yeast MnSOD both rest in the 2+ state and become six-coordinate when oxidized up from Mn{sup 2+}, six-coordinate Mn{sup 3+} species could also actively function in the mechanism of WT yeast MnSODs.

Sheng, Yuewei; Gralla, Edith Butler; Schumacher, Mikhail; Cascio, Duilio; Cabelli, Diane E.; Valentine, Joan Selverstone (EWHA); (UCLA); (BNL)

2012-10-10

437

Recent progress in understanding reactor pressure vessel steel embrittlement  

NASA Astrophysics Data System (ADS)

This paper reviews the current understanding of the basic mechanisms of irradiation embrittlement in reactor pressure vessel steels. Radiation enhanced diffusiona at operating temperatures around 290°C leads to the formation of various ultrafine scale hardening phases, including copper rich and copper catalysed manganese-nickel rich precipitates. Other nanofeatures that do not require copper, so-called matrix defects, include alloy phosphides and carbonitrides as well as defect cluster-solute complexes. Matrix defects that are thermally unstable (anneal) under irradiation play a very important role in mediating flux and temperature effects. The balance of features depends on the composition of the steel and the irradiation conditions. Copper enriched phases, which are the dominant embrittling feature in alloys containing significant trace quantities of this element, are fairly well understood. In contrast, the detailed identity and etiology of the matrix defects and manganese-nickel rich phases that may form in very low copper steels has not yet been established. Embrittlement of typical (Mn-Mo-Ni) pressure vessel steels, manifested as shifts in Charpy V-notch transition temperature, can generally be related to yield stress increases. Yield stress increases from copper rich precipitates are consistent with predictions using defect-obstacle interaction theory coupled with a new model for superposition of the hardening from both pre- and post-irradiation sources of strength. Details of the strengthening contributions from the other irradiation features are not as well established, but appear to be reasonably consistent with theory. These concepts have led to the development of thermodynamic-kinetic-micromechanical models that are broadly consistent with experiment, and rationalize the highly synergistic effects of important irradiation (e.g., temperature, flux, fluence) and metallurgical (e.g., copper, nickel, manganese, phosphorous and heat treatment) variables on both irradiation hardening and hardening recovery during post-irradiation annealing. Open questions can be addressed with a hierarchy of new theoretical and experimental tools, which range from atomistic modeling to tomographic methods of observing the sequence-of-events leading to fracture. Advanced microstructural evolution, microstructure-property and micromechanical models, validated and calibrated by well designed experiments, will greatly enhance our ability to predict pressure vessel embrittlement and to resolve out-standing technical issues.

Odette, G. R.; Lucas, G. E.

438

Sulfur dioxide leaching of spent zinc–carbon-battery scrap  

Microsoft Academic Search

Zinc–carbon batteries, which contain around 20% zinc, 35% manganese oxides and 10% steel, are currently disposed after use as land fill or reprocessed to recover metals or oxides. Crushed material is subjected to magnetic separation followed by hydrometallurgical treatment of the non-magnetic material to recover zinc metal and manganese oxides. The leaching with 2M sulfuric acid in the presence of

J. Avraamides; G. Senanayake; R. Clegg

2006-01-01

439

Influence of inclusion characteristics on the formability and toughness properties of a hot-rolled deep-drawing quality steel  

Microsoft Academic Search

In industrial practice, variations in the steelmaking process may cause significant change in inclusion characteristics. During\\u000a hot rolling of flat steel products, manganese sulfides, which are plastic at elevated temperatures, are elongated in the rolling\\u000a direction. These elongated inclusions affect the formability properties, such as ductility, strain hardening exponent, average\\u000a plastic strain ratio, critical strain represented by the forming limit

S. K. Paul; A. Ray

1997-01-01

440

Hydrogen-induced cracking in 4340-type steel: Effects of composition, yield strength, and H 2 pressure  

Microsoft Academic Search

Measurements of the threshold stress intensity for hydrogen-induced crack extension,Kth at room temperature were made on bolt-loaded WOL specimens of a commercial 4340 steel and of laboratory heats in which the\\u000a bulk concentrations of manganese, silicon, phosphorus, and sulfur were varied. The hydrogen pressure was varied from 200 to\\u000a 1600 torr (~0.03 to 0.22 MPa), and the yield strengths were

N. Bandyopadhyay; Jun Kameda; C. J. Mcmahon

1983-01-01

441

Determination of manganese in human brain samples.  

PubMed

A method is presented for the determination of manganese (Mn) in human tissue samples (especially brain) by graphite furnace atomic absorption spectrophometry (GFAAS). After complete digestion by a mixture of concentrated nitric acid (HNO3)/concentrated perchloric acid (HClO4) (50:50, v/v), the samples are assayed on a Perkin-Elmer 5100 PC apparatus, equipped with transversal graphite tubes and a Mn-specific hollow cathode lamp. The furnace conditions are as follows (for each step: temperature (degree C)/ramp (s)/duration (s)) dry 120/1/40; char 1200/5/10; atomization 2250/0/4; pyrolysis 2400/1/1. Zeeman correction is employed. The method is linear over the range 0.05 to 5.00 micrograms/g wet tissue, and the limit of detection for Mn is about 0.01 microgram/g wet tissue. This simple and rapid method may be of value for the post-mortem assessment of Mn accumulation in brain structures due to occupational or iatrogenic exposure. An application is presented in which elevated levels of Mn were determined in the brain samples of a 63-year-old female deceased after long-term total parenteral nutrition involving Mn supplementation. PMID:8566922

Tracqui, A; Tayot, J; Kintz, P; Alves, G; Bosque, M A; Mangin, P

1995-12-29

442

Manganese superoxide dismutase: guardian of the powerhouse.  

PubMed

The mitochondrion is vital for many metabolic pathways in the cell, contributing all or important constituent enzymes for diverse functions such as ?-oxidation of fatty acids, the urea cycle, the citric acid cycle, and ATP synthesis. The mitochondrion is also a major site of reactive oxygen species (ROS) production in the cell. Aberrant production of mitochondrial ROS can have dramatic effects on cellular function, in part, due to oxidative modification of key metabolic proteins localized in the mitochondrion. The cell is equipped with myriad antioxidant enzyme systems to combat deleterious ROS production in mitochondria, with the mitochondrial antioxidant enzyme manganese superoxide dismutase (MnSOD) acting as the chief ROS scavenging enzyme in the cell. Factors that affect the expression and/or the activity of MnSOD, resulting in diminished antioxidant capacity of the cell, can have extraordinary consequences on the overall health of the cell by altering mitochondrial metabolic function, leading to the development and progression of numerous diseases. A better understanding of the mechanisms by which MnSOD protects cells from the harmful effects of overproduction of ROS, in particular, the effects of ROS on mitochondrial metabolic enzymes, may contribute to the development of novel treatments for various diseases in which ROS are an important component. PMID:22072939

Holley, Aaron K; Bakthavatchalu, Vasudevan; Velez-Roman, Joyce M; St Clair, Daret K

2011-10-21

443

Manganese Ferrite Grown at Atomic Scale  

SciTech Connect

Manganese spinel ferrite (MnFe{sub 2}O{sub 4}) films were deposited at the atomic scale. In the depositions, laser pulses alternately impinged MnO and Fe{sub 2}O{sub 3} targets and sequentially deposited thin layers ({approx}5 {angstrom}) of MnO and Fe{sub 2}O{sub 3} on MgO substrate, which is referred to as 'artificial' films. The X-ray diffraction measurements showed that the artificial films were of spinel structure. Auger spectroscopy measurements showed that the chemical composition of the artificial ferrites were consistent with that of standard films deposited using a single target of MnFe{sub 2}O{sub 4}. However, extended X-ray absorption fine spectroscopy showed that the artificial growth technique affected the cation distribution to be different from the standard films. As a result, the magnetic properties of the artificial films, including Neel temperature, uniaxial and in-plane anisotropy, were different from the standard films.

Zuo,X.; Yang, F.; Mafhoum, R.; Karim, R.; Tebano, A.; Balestrino, G.; Harris, V.; Vittoria, C.

2004-01-01

444

Electrical properties of a layered manganese vanadate  

NASA Astrophysics Data System (ADS)

We present the electrical characteristics of a layered manganese vanadate. Octahedral Mn and tetrahedral V units form layers that in turn are connected to each other via weakly bonded strontium ions. The Mn sites are also connected to each other through bridging oxygen atoms that are partially protonated, allowing for possible proton conduction in the material. The conductivity is dependent on crystal direction. Variable temperature conductivity measurements, from 160 to 830 K, show semiconducting behavior with average activation energy of 0.35 eV. Around 670 K a dip in the conductivity is observed, correlated with loss of water from the structure inferred from thermogravimetric analysis. Above 760K, an increase in conductivity is observed. Single crystal x-ray analysis is performed on samples heated above 670 K, to probe temperature induced structural changes. Preliminary results show a contraction of one of the unit cell axes corresponding to the loss of the bridging oxygen and the ensuing movement of the two Mn sites closer to each other. Single crystal x-ray investigations of the material under hydrostatic pressure in a DAC are also performed, to probe the influence of structural changes on electronic transport properties.

Soghomonian, Victoria; Yuan, Qifan; Spencer, Elinor; Ross, Nancy

2012-02-01

445

Redundancy among Manganese Peroxidases in Pleurotus ostreatus  

PubMed Central

Manganese peroxidases (MnPs) are key players in the ligninolytic system of white rot fungi. In Pleurotus ostreatus (the oyster mushroom) these enzymes are encoded by a gene family comprising nine members, mnp1 to -9 (mnp genes). Mn2+ amendment to P. ostreatus cultures results in enhanced degradation of recalcitrant compounds (such as the azo dye orange II) and lignin. In Mn2+-amended glucose-peptone medium, mnp3, mnp4, and mnp9 were the most highly expressed mnp genes. After 7 days of incubation, the time point at which the greatest capacity for orange II decolorization was observed, mnp3 expression and the presence of MnP3 in the extracellular culture fluids were predominant. To determine the significance of MnP3 for ligninolytic functionality in Mn2+-sufficient cultures, mnp3 was inactivated via the ?ku80 strain-based P. ostreatus gene-targeting system. In Mn2+-sufficient medium, inactivation of mnp3 did not significantly affect expression of nontargeted MnPs or their genes, nor did it considerably diminish the fungal Mn2+-mediated orange II decolorization capacity, despite the significant reduction in total MnP activity. Similarly, inactivation of either mnp4 or mnp9 did not affect orange II decolorization ability. These results indicate functional redundancy within the P. ostreatus MnP gene family, enabling compensation upon deficiency of one of its members.

Salame, Tomer M.; Knop, Doriv; Levinson, Dana; Yarden, Oded

2013-01-01

446

Development of a Field Method for Measuring Manganese in Welding Fume.  

National Technical Information Service (NTIS)

Workers who perform routine welding tasks are potentially exposed to fume that may contain manganese. Manganese may cause respiratory problems and is implicated in causing the occurrence of Parkinson-like symptoms. In this study, a field colorimetric meth...

D. Marcy P. L. Drake

2008-01-01

447

Ultrahigh Carbon Steels  

NASA Astrophysics Data System (ADS)

Recent studies and results on ultrahigh carbon (UHC) steels suggest that major development efforts on these steels are timely and that programs to evaluate prototype structural components should be initiated. These recent results include: the development of economical processing techniques incorporating a divorced eutectoid transformation, the improvement of room temperature strength and ductility by heat treatment, the enhancement of superplastic properties through dilute alloying with silicon, and the attainment of exceptional notch impact strength in laminated UHC steel composites manufactured through solid state bonding. The unique mechanical properties achieved in UHC steels are due to the presence of micron-size fer-rite grains and ultrafine spheroidized carbides.

Sherby, O. D.; Oyama, T.; Kum, D. W.; Walser, B.; Wadsworth, J.

1985-06-01

448

Manganese sulfide formation via concomitant microbial manganese oxide and thiosulfate reduction.  

PubMed

The dissimilatory metal-reducing bacterium, Shewanella oneidensis MR-1 produced ?-MnS (rambergite) nanoparticles during the concurrent reduction of MnO? and thiosulfate coupled to H? oxidation. To investigate effect of direct microbial reduction of MnO? on MnS formation, two MR-1 mutants defective in outer membrane c-type cytochromes (?mtrC/?omcA and ?mtrC/?omcA/?mtrF) were also used and it was determined that direct reduction of MnO? was dominant relative to chemical reduction by biogenic sulfide generated from thiosulfate reduction. Although bicarbonate was excluded from the medium, incubations of strain MR-1 with lactate as the electron donor produced MnCO? (rhodochrosite) as well as MnS in nearly equivalent amounts as estimated by micro X-ray diffraction (micro-XRD) analysis. It was concluded that carbonate released from lactate metabolism promoted MnCO? formation and that Mn(II) mineralogy was strongly affected by carbonate ions even in the presence of abundant sulfide and weakly alkaline conditions expected to favour the precipitation of MnS. Formation of MnS, as determined by a combination of micro-XRD, transmission electron microscopy, energy dispersive X-ray spectroscopy, and selected area electron diffraction analyses was consistent with equilibrium speciation modelling predictions. Biogenic manganese sulfide may be a manganese sink in the Mn biogeochemical cycle in select environments such as deep anoxic marine basins within the Baltic Sea. PMID:21951417

Lee, Ji-Hoon; Kennedy, David W; Dohnalkova, Alice; Moore, Dean A; Nachimuthu, Ponnusamy; Reed, Samantha B; Fredrickson, James K

2011-09-27

449

The sorption of silver by poorly crystallized manganese oxides  

USGS Publications Warehouse

The sorption of silver by poorly crystallized manganese oxides was studied using synthesized samples of three members of the manganous manganite (birnessite) group, of different chemical composition and crystallinity, and a poorly organized ??-MnO2. All four oxides sorbed significant quantities of silver. The manganous manganites showed the greatest sorption (up to 0.5 moles silver/mole MnOx at pH 7) while the ??-MnO2 showed the least (0.3 moles silver/ mole MnOx at pH 7). Sorption of silver was adequately described by the Langmuir equation over a considerable concentration range. The relationship failed at low pH values and high equilibrium silver concentrations. The sorption capacity showed a direct relationship with pH. However, the rate of increase of sorption capacity decreased at the higher pH values. Silver sorption maxima. were not directly related to surface area but appeared to vary with the amount of occluded sodium and potassium present in the manganese oxide. The important processes involved in the uptake of silver by the four poorly crystallized manganese oxides ara considered to be surface exchange for manganese, potassium and sodium as well as exchange for structural manganese, potassium and sodium. ?? 1973.

Anderson, B. J.; Jenne, E. A.; Chao, T. T.

1973-01-01

450

Ammonia and manganese increase arginine uptake in cultured astrocytes.  

PubMed

Recent work has suggested a possible role for nitric oxide (NO) in the development of hepatic encephalopathy (HE). In this study, we examined the effect of ammonia and manganese, factors implicated in the pathogenesis of HE, on the transport of arginine (a precursor of NO) into primary cultures of astrocytes. Treatment with 5 mM ammonia for 1-4 days produced a maximal (53%) increase in L-arginine uptake at 3 days when compared to untreated cells. Kinetic analysis following 4-day treatment with 5 mM ammonia revealed an 82% increase in the Vmax and a 61% increase in the Km value. Similar analysis with 100 microM manganese showed a 101% increase in Vmax and a 131% increase in the Km value. These results suggest that both manganese and ammonia alter L-arginine uptake by modifying the transporter for arginine. A decrease of 32% in the non-saturable component of L-arginine transport was also observed following treatment with ammonia. When cultures were treated separately with 5 mM ammonia and 100 microM manganese for 2 days, the uptake of L-arginine increased by 41% and 57%, respectively. Combined exposure led to no further increase in uptake. Our results suggest that ammonia and manganese may contribute to the pathogenesis of HE by influencing arginine transport and thus possibly NO synthesis in astrocytes. PMID:9572676

Hazell, A S; Norenberg, M D

1998-06-01

451

Manganese, iron, and total particulate exposures to welders.  

PubMed

Welders are exposed to a variety of metal fumes, including manganese, that may elevate the risk for neurological disease. This study examines several large data sets to characterize manganese, iron, and total particulate mass exposures resulting from welding operations. The data sets contained covariates for a variety of exposure modifiers, including the presence of ventilation, the degree of confinement, and the location of the personal sampler (i.e., behind or in front of the welding helmet). The analysis suggests that exposures to manganese are frequently at or above the current ACGIH(R) threshold limit value of 0.2 mg/m(3). In addition, there is evidence that local exhaust ventilation can control the exposures to manganese and total fume but that mechanical ventilation may not. The data suggest that higher exposures are associated with a greater degree of enclosure, particularly when local exhaust ventilation is absent. Samples taken behind the helmet were, in general, lower than those measured outside of it. There were strong correlations among manganese, iron, and total particulate mass exposures, suggesting simple equations to estimate one fume component from any of the others. PMID:20013450

Flynn, Michael R; Susi, Pam

2010-02-01

452

The Structural Stability of Manganese Oxide Electrodes for Lithium Batteries  

NASA Astrophysics Data System (ADS)

Manganese oxides are of interest as insertion electrodes for rechargeable 3 V and 4 V lithium batteries. During discharge, lithium ions are inserted into the manganese oxide host structure with a concomitant reduction of the manganese ions; the reverse process occurs on charge. The cycle life of these batteries is critically dependent on the ability of the manganese oxide structure to maintain its structural integrity during discharge and charge. Although manganese dioxide exists in several polymorphic forms, most of these undergo severe crystallographic distortions or transformations on lithiation, for example, rutile-Li_xMnO_2, ramsdellite-Li_xMnO2 and spinel-Li_1+xMn_2O_4. The distortions arise largely because of the onset of a Jahn-Teller effect when the concentration of Mn^3+ (d^4) ions reaches a critical value. This paper discusses the progress that has been made to stabilize various MnO2 structures to enhance their stability to lithium insertion/extraction reactions.

Thackeray, Michael M.

1997-03-01

453

Determination of manganese in blood and urine by flameless atomic absorption spectrophotometry.  

PubMed

A method for the determination of manganese in blood and urine is described. A chelate fo manganese with cupferron is extracted with methylisobutylketone and determined by flameless atomic absorption spectrophotometry. The method is directly applicable to urine but the determination of manganese in blood required a preliminary digestion step. With the use of internal standards, this technique allows the determination of manganese concentrations of the order of 1 mug/1 of urine or 1 mug/100 ml whole blood. PMID:1000867

Buchet, J P; Lauwerys, R; Roels, H; De Vos, C

1976-12-01

454

Preparation of an electrochemically-formed spinel lithium manganese oxide and its charge–discharge behaviors  

Microsoft Academic Search

Manganese hydroxides were prepared by a cathodic electrochemical precipitation from a manganese nitrate solution. The grass blade-like precipitate, which is ascribed to manganese hydroxide was 20–80?m long and 1–5?m wide and was spread out on a Pt substrate after the electrochemical precipitation. When the electrochemically precipitated manganese hydroxides were kept in an alkali metal hydroxide aqueous solution, such as NaOH,

Katsumi Katakura; Shin-ichi Nishimura; Zempachi Ogumi

2005-01-01

455

Effects of chronic manganese exposure on cognitive and motor functioning in non-human primates  

Microsoft Academic Search

Acute exposure to manganese is associated with complex behavioral\\/psychiatric signs that may include Parkinsonian motor features. However, little is known about the behavioral consequences of chronic manganese exposures. In this study, cynomolgus macaque monkeys were exposed to manganese sulfate (10–15mg\\/kg\\/week) over an exposure period lasting 272±17days. Prior to manganese exposure, animals were trained to perform tests of cognitive and motor

Jay S. Schneider; Emmanuel Decamp; Amy Jo Koser; Stephanie Fritz; Heather Gonczi; Tore Syversen; Tomás R. Guilarte

2006-01-01

456

Electrochemical concepts and techniques in the study of stainless steel ennoblement.  

PubMed

Electrochemical theory and technique used to investigate microbially influenced corrosion is discussed with a focus on methods used to demonstrate the manganic-oxide mechanism of stainless steel Ennoblement. The concept of mixed potential and its relationship to the current-voltage behavior of stainless steel is developed. This concept is used to interpret microbially induced changes in corrosion potential, polarization behavior, surface-oxide abundance, and the redox environment at submerged metal surfaces. Microelectrode, capacitance, and coulometric methods are described that can be used to discriminate electrochemical effects caused by changes in solution properties from those caused by mineral deposition at the metal surface. The variety of electrochemical, wet-chemical, microbiological, and surface analytical techniques used to demonstrate the effect of biomineralized manganese dioxide on the electrochemical behavior of stainless steel are summarized. PMID:9807801

Dickinson, W H; Lewandowski, Z

1998-01-01

457

Effect of Silicon on the Desulfurization of Al-Killed Steels: Part I. Mathematical Model  

NASA Astrophysics Data System (ADS)

Recent observations suggest that increased silicon levels improve ladle desulfurization of aluminum-killed steel. While the overall desulfurization reaction of Al-killed steels does not show a direct role of silicon in desulfurization, model calculations are presented which test the idea that silicon suppresses the reduction of silica which can consume aluminum at the slag/metal interface. Consumption of aluminum would increase the oxygen potential at the slag/metal interface and decrease the sulfur partition coefficient between slag and metal. The model considers the coupled reactions of the reduction of silica, iron oxide, and manganese oxide in the slag and desulfurization of the steel by aluminum. The results show that silicon can indeed suppress consumption of aluminum at the slag/metal interface by side reactions other than desulfurization, with silicon affecting both the kinetics and the equilibrium of desulfurization.

Roy, Debdutta; Pistorius, Petrus Christiaan; Fruehan, Richard J.

2013-10-01

458

Effect of Sulfur and Zirconium on the Machinability and Mechanical Properties of AISI 1045 Steels  

NASA Astrophysics Data System (ADS)

The effects of small increases of sulfur and addition of zirconium in conjunction with sulfur on the machinability and mechanical properties of laboratory-produced AISI 1045 steels have been investigated. Machinability was measured in terms of cutting energy per unit volume of metal machined. With increasing sulfur, there is a linear increase in sulfide volume fraction and improvement in machinability. Ductility parameters such as tensile reduction in area and impact shelf energy, however, significantly decrease with sulfur, particularly in the transverse direction. Addition of zirconium causes formation of manganese-zirconium sulfides and increased globularity. Although further improvement in machinability by zirconium addition is not evident, there is a significant improvement in transverse impact properties by zirconium addition for steels containing high sulfur. The study suggests that an optimum combination of higher sulfur for improved machinability and zironium for better impact properties yields a steel with acceptable machining and ductility criteria.

Bhattacharya, Debanshu

1981-06-01

459

ACID LEACHING AND ELECTROCHEMICAL RECOVERY OF MANGANESE FROM SPENT ALKALINE BATTERIES  

Microsoft Academic Search

This paper discusses a procedure for manganese recovery as manganese dioxide by anodic oxidation of acid solutions obtained by leaching of spent alkaline batteries with sulfuric acid. Spent size D alkaline batteries were dismantled, separating case, contacts and separator from the reactive paste. A series of laboratory tests were conducted to define the best conditions for manganese and zinc extraction

C. A. Andrade Tacca; M. M. E. Duarte

460

Proceedings of the symposium on manganese dioxide electrode theory and practice for electrochemical applications  

SciTech Connect

This book presents the papers given at a symposium on the use of manganese dioxide in the fabrication of electric batteries. Topics considered at the symposium included manganese oxides as battery cathodes, electrochemistry, chemical activation, chemical reaction kinetics, voltage recovery behavior, rechargeability, and manganese dioxide in alkaline electrolytes.

Middaugh, R.L.; Hunter, J.C.; Schumm, B.; Grotheer, M.P.

1985-01-01

461

40 CFR 721.10529 - Cobalt iron manganese oxide, carboxylic acid-modified (generic).  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Cobalt iron manganese oxide, carboxylic acid-modified...Chemical Substances § 721.10529 Cobalt iron manganese oxide, carboxylic acid-modified...chemical substance identified generically as cobalt iron manganese oxide, carboxylic...

2013-07-01

462

In vivo stimulation-induced release of manganese in rat amygdala  

Microsoft Academic Search

The role of manganese ions in neural functions is poorly understood because of the low level of manganese in the brain. An excess of this ion is associated with neurological disorders such as extrapyramidal symptoms. We demonstrated that manganese may be taken up by piriform neurons (tertiary olfactory neurons) after release from the terminals of secondary olfactory neurons, in which

Atsushi Takeda; Shioji Ishiwatari; Shoji Okada

1998-01-01

463

40 CFR 721.10010 - Barium manganese oxide (BaMnO3).  

Code of Federal Regulations, 2010 CFR

...2009-07-01 2009-07-01 false Barium manganese oxide (BaMnO3). 721.10010...Chemical Substances § 721.10010 Barium manganese oxide (BaMnO3 ). (a...The chemical substance identified as barium manganese oxide (BaMnO3 )...

2009-07-01

464

40 CFR 721.10010 - Barium manganese oxide (BaMnO3).  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Barium manganese oxide (BaMnO3). 721.10010...Chemical Substances § 721.10010 Barium manganese oxide (BaMnO3). (a...The chemical substance identified as barium manganese oxide (BaMnO3 )...

2010-07-01

465

40 CFR 721.10010 - Barium manganese oxide (BaMnO3).  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Barium manganese oxide (BaMnO3). 721.10010...Chemical Substances § 721.10010 Barium manganese oxide (BaMnO3 ). (a...The chemical substance identified as barium manganese oxide (BaMnO3 )...

2013-07-01

466

Effects of manganese on chemically induced food search behaviour of the Norway lobster, Nephrops norvegicus (L.)  

Microsoft Academic Search

The decapod Norway lobster, Nephrops norvegicus (L.), lives on muddy sediments rich in manganese (Mn). In hypoxic conditions, manganese is reduced and released from the sediment, so increased concentrations of dissolved Mn2+ become bioavailable. In excess, manganese acts as a neurotoxin and may inhibit vital functions of benthic organisms, such as muscle contraction. We investigated in a laboratory flume experiment,

Anna-Sara Krång; Gunilla Rosenqvist

2006-01-01

467

Fate of manganese associated with the inhalation of welding fumes: Potential neurological effects  

Microsoft Academic Search

Welding fumes are a complex mixture composed of different metals. Most welding fumes contain a small percentage of manganese. There is an emerging concern among occupational health officials about the potential neurological effects associated with the exposure to manganese in welding fumes. Little is known about the fate of manganese that is complexed with other metals in the welding particles

James M. Antonini; Annette B. Santamaria; Neil T. Jenkins; Elisa Albini; Roberto Lucchini

2006-01-01

468

Role of liver lysosomes in uptake and biliary excretion of manganese in mice  

SciTech Connect

To determine the mechanism of manganese excretion from the liver into bile, manganese content in blood, bile, whole liver, and subcellular fractions of liver was measured following intraperitoneal injection of a single dose of manganese (49 mg Mn(OAc)/sub 2/. 4H/sub 2/O/kg body wt) in mice. Manganese in blood was rapidly incorporated into liver and appeared in bile within hours. Most of the absorbed manganese in liver was recovered in the mitochondrial-lysosomal fraction. Purified nuclei contained only one-tenth of the manganese found in the crude nuclear fraction. Sucrose density gradient centrifugation revealed that lysosomes took up and released manganese more rapidly than mitochondria. Also, manganese content in the liver and bile decreased following pretreatment with trypan blue. These values returned to normal with simultaneous administration of cortisone. Manganese released in vitro from the mitochondrial-lysosomal fraction and manganese in bile were measured as manganese acetate by gel filtration. The results suggest that liver lysosomes play an important role in intrahepatic movement and affect biliary excretion of absorbed manganese.

Suzuki, H.; Wada, O.

1981-12-01

469

40 CFR 721.10009 - Manganese yttrium oxide (MnYO3).  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Manganese yttrium oxide (MnYO3). 721.10009...Chemical Substances § 721.10009 Manganese yttrium oxide (MnYO3 ). (a...The chemical substance identified as manganese yttrium oxide (MnYO3 ) (PMN...

2013-07-01

470

40 CFR 721.10013 - Manganese yttrium oxide (Mn2YO5).  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Manganese yttrium oxide (Mn2YO5). 721.10013...Chemical Substances § 721.10013 Manganese yttrium oxide (Mn2 YO5 ). ...The chemical substance identified as manganese yttrium oxide (Mn2 YO5 )...

2013-07-01

471

40 CFR 721.10008 - Manganese strontium oxide (MnSrO3).  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Manganese strontium oxide (MnSrO3). 721...Chemical Substances § 721.10008 Manganese strontium oxide (MnSrO3 ). ...The chemical substance identified as manganese strontium oxide (MnSrO3 )...

2013-07-01

472

ADDing it up: soy infant formula, ADD\\/ADHD, and manganese toxicity  

Microsoft Academic Search

Manganese is an essential trace mineral, but high levels are neurotoxic to newborns. Infants fed soy infant formula ingest as much as 80 times more manganese per day than those who are breast fed. Although healthy toddlers, children and adults exposed to excess manganese can usually eliminate most of it, infants cannot because their immature livers are not fully functional.

Kaayla T. Daniel

2005-01-01

473

Rashba Effect in Non-Magnetic InGaAs/GaAsSb Resonant Tunneling Diodes Enhanced By Transverse Magnetic Field  

NASA Astrophysics Data System (ADS)

A large Rashba splitting enhanced by an in-plane magnetic field is observed in non-magnetic InGaAs/GaAsSb/InGaAs resonant tunneling diodes over a wide range of temperatures. The current resonances split by the Rashba effect reveal peak to valley ratios up to 2.5:1, the energy spacing between the split peaks reaches values up to 30 meV at B = 5T. The observed peak splitting is robust and can be observed at temperatures as high as T = 180K. The largest Rashba parameter determined from the split peak positions is ? = 0.78 eVA?. This value is consistent with literature values reported for InGaAs based devices.

de Sousa, J. Silvano; Detz, H.; Klang, P.; Gornik, E.; Strasser, G.; Smoliner, J.

2011-12-01

474

Quantum interference with angle-dependent partial frequency redistribution: solution of the polarized line transfer in the non-magnetic case  

NASA Astrophysics Data System (ADS)

Angle-dependent partial frequency redistribution (PRD) matrices represent the physical redistribution in the process of light scattering on atoms. For the purpose of numerical simplicity, it is a common practice in astrophysical literature to use the angle-averaged versions of these matrices, in the line transfer computations. The aim of this paper is to study the combined effects of angle-dependent PRD and the quantum interference phenomena arising either between the fine structure (J) states of a two-term atom or between the hyperfine structure (F) states of a two-level atom. We restrict our attention to the case of non-magnetic and collisionless line scattering on atoms. A rapid method of solution based on Neumann series expansion is developed to solve the angle-dependent PRD problem including quantum interference in an atomic system. We discuss the differences that occur in the Stokes profiles when angle-dependent PRD mechanism is taken into account.

Supriya, H. D.; Smitha, H. N.; Nagendra, K. N.; Ravindra, B.; Sampoorna, M.

2013-02-01

475

Long-term follow-up of workplace and well water manganese effects on iron status indexes in manganese miners.  

PubMed

The authors assessed the effect of water reconstitution in the workplace by evaluating the iron status of manganese mine workers during a long-term study. Subsequent analyses and biological monitoring were performed in a group of 150 manganese miners before, and 2.8 yr after, reconstitution of drinking water in the miners' workplace. The authors found significantly high concent