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1

STRAIN AGING OF AUSTENITIC HADFIELD MANGANESE STEEL  

E-print Network

STRAIN AGING OF AUSTENITIC HADFIELD MANGANESE STEEL W. S. OWEN1 { and M. GRUJICIC2 1 Department. INTRODUCTION Had®eld manganese steel, here represented by the nominal composition Fe±12Mn±1.2C wt%, is a stable. Noting that manganese decreases the activity of carbon in austenite, they speculated that the relatively

Grujicic, Mica

2

Manganese partitioning in low carbon manganese steel during annealing  

Microsoft Academic Search

For 6Mn16 steel experimental soft annealing at 625C for periods from 1h to 60h 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

J. Lis; A. Lis; C. Kolan

2008-01-01

3

On the deformation mechanisms in single crystal Hadfield manganese steels  

SciTech Connect

Austenitic manganese steel, so called Hadfield manganese steel, is frequently used in mining and railroad frog applications requiring excessive deformation and wear resistance. Its work hardening ability is still not completely understood. Previous studies attributed the work-hardening characteristics of this material to dynamic strain aging or an imperfect deformation twin, a so-called pseudotwin. Unfortunately, these previous studies have all focused on polycrystalline Hadfield steels. To properly study the mechanisms of deformation in the absence of grain boundary or texture effects, single crystal specimens are required. The purpose of this work is the following: (1) observe the inelastic stress-strain behavior of Hadfield single crystals in orientations where twinning and slip are individually dominating or when they are competing deformation mechanisms; and (2) determine the microyield points of Hadfield single crystals and use micro-mechanical modeling to predict the stress-strain response of a single crystal undergoing micro-twinning.

Karaman, I.; Sehitoglu, H.; Gall, K. [Univ. of Illinois, Urbana, IL (United States). Dept. of Mechanical and Industrial Engineering] [Univ. of Illinois, Urbana, IL (United States). Dept. of Mechanical and Industrial Engineering; Chumlyakov, Y.I. [Siberian Physical and Technical Inst., Tomsk (Russian Federation). Physics of Plasticity and Strength of Materials Lab.] [Siberian Physical and Technical Inst., Tomsk (Russian Federation). Physics of Plasticity and Strength of Materials Lab.

1998-02-13

4

Influence of carbon, manganese and nickel on microstructure and properties of strong steel  

E-print Network

Influence of carbon, manganese and nickel on microstructure and properties of strong steel weld strength steel weld metal with 7 wt-% nickel and 0.5 wt-% manganese could be increased significantly metal, Nickel, Manganese, Strength, Impact toughness, Carbon, Bainite, Martensite, Microstructure

Cambridge, University of

5

Corrosion of stainless steel piping in high manganese fresh water  

SciTech Connect

A potable water treatment plant, designed to reduce manganese and iron in well water, experienced leaks in the 16 in. (406 mm) raw water headers about nine months after startup. The material, type 304 (UNS 30403) stainless steel, was purchased to American Society of Testing Materials specification A 778, with additional stipulations governing internal finish, the use of filler metal, and pickling for scale removal. Laboratory screenings of deposits for bacteria revealed some potentially additive corrosive effects from microbial action. However, the correlation of corrosion with the presence or absence of heat tint in the heat-affected zone of the circumferential welds prevailed as a primary cause of the corrosion observed beneath an adherent manganese-iron deposit in a low chloride, high manganese, raw water.

Avery, R.E. [Nickel Development Inst., Londonderry, NH (United States); Lutey, R.W. [Buckman Labs., Memphis, TN (United States); Musick, J. [Whitman and Howard, Portland, ME (United States); Pinnow, K.E. [Crucible Research, Pittsburgh, PA (United States); Tuthill, A.H. [Nickel Development Inst., Blacksburg, VA (United States)

1996-09-01

6

Influence of carbon, manganese and nickel on microstructure and properties of strong steel  

E-print Network

Influence of carbon, manganese and nickel on microstructure and properties of strong steel weld with 2 wt-% manganese. Nickel additions were beneficial to strength but detrimental to impact toughness. Significant segregation of nickel and manganese to interdendritic regions was observed at the two higher

Cambridge, University of

7

Influence of carbon, manganese and nickel on microstructure and properties of strong steel  

E-print Network

Influence of carbon, manganese and nickel on microstructure and properties of strong steel weld metals Part 2 ­ Impact toughness gain resulting from manganese reductions E. Keehan*1 , L. Karlsson2 , H with 7 wt-% nickel and either 2 or 0.5 wt-% manganese. Neural network predictions that it is advantageous

Cambridge, University of

8

The five-parameter grain boundary character and energy distributions of a fully austenitic high-manganese steel using  

E-print Network

The five-parameter grain boundary character and energy distributions of a fully austenitic high-manganese-dimensional interfacial grain boundary network in a fully austenitic high-manganese steel was studied as a function of all A new generation of high-manganese steels has recently received significant attention among research

Rohrer, Gregory S.

9

Effect of manganese and niobium on the properties of low-alloy steels  

Microsoft Academic Search

The strength and ductility characteristics, toughness parameters, and structure of low-alloy steels after thermomechanical\\u000a treatment are studied. Analysis of the properties of steels with various manganese-to-niobium ratios is performed. An optimum\\u000a chemical composition for sheet steel subjected to thermomechanical treatment is suggested.

S. V. Aleksandrov; K. Hulka; A. M. Stepashin; Yu. D. Morozov

2005-01-01

10

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

E-print Network

Microstructural and mechanical effects of nickel and manganese on high strength steel weld metals E Neural network modelling suggested that the impact strength of high-strength steel weld metals could-strength steel weld metals has been a constant topic of research in the last two decades. In many applications

Cambridge, University of

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

Manganese biofouling and the corrosion behavior of stainless steel  

Microsoft Academic Search

Manganese? and iron?oxidizing bacteria (MFOB) are widely implicated in microbially influenced corrosion, often in association with sulfate?reducing bacteria (SRB). Traditionally MFOB have been assigned a passive role in the corrosion process, promoting differential aeration cells, and providing oxygen depleted conditions conducive to the growth and corrosive attack of SRB. Recent work, summarized in this article, demonstrates that manganese biofouling alters

W. H. Dickinson; Z. Lewandowski

1996-01-01

13

Nickel-free manganese bearing stainless steel in alkaline mediaElectrochemistry and surface chemistry  

Microsoft Academic Search

The use of austenitic nickel-containing stainless steels as concrete reinforcement offers excellent corrosion protection for concrete structures in harsh chloride bearing environments but is often limited due to the very high costs of these materials. Manganese bearing nickel-free stainless steels can be a cost-effective alternative for corrosion resistant reinforcements. Little, however, is known about the electrochemistry and even less on

B. Elsener; D. Addari; S. Coray; A. Rossi

2011-01-01

14

Effect of Different Casting Parameters on the Cleanliness of High Manganese Steel Ingots Compared to High Carbon Steel  

NASA Astrophysics Data System (ADS)

The increasing demand for excellent steel properties has led to the creation of new steel grades such as high manganese TWIP and TRIP steels which are scientifically examined in Germany within the international research framework of the SFB 761 "Steel-ab initio." The production of these high-technology products, utilizing mainly the ingot-casting method, leads to new challenges in the prevention of cast defects. At RWTH Aachen University, a systematic investigation of the solidification process as it relates to shrinkage cavity, macrosegregation, cleanliness, and surface imperfections in as-cast ingots is being conducted. A particular attention was devoted to the effects of such casting parameters as superheat, pouring rate, hot top, and stirring conditions on the solidification and cleanliness of low carbon alloyed and high manganese alloyed steels. The experimental results show that rising manganese content leads to a higher amount and larger size of inclusions while rising carbon content enhances the inclusion generation in the same way. It was found that a bottom teeming system combined with an inert gas atmosphere produces the best quality and that if casting is performed with a runner-system, it is important to use a SiO2-free refractory to avoid oxidizing the Mn content of the melt to MnO inclusions by redox-reactions.

von Schweinichen, Petrico; Chen, Zhiye; Senk, Dieter; Lob, Alexander

2013-12-01

15

By Thomas S. Jones Manganese (Mn) is essential to iron and steel production by have been among the larger producers. World production of  

E-print Network

1 MANGANESE By Thomas S. Jones Manganese (Mn) is essential to iron and steel production by have, and alloying properties. manganese ferroalloys was estimated to have been in the same Currently, no practical component, has accounted for most domestic manganese which statistics have been rounded. demand, presently

Torgersen, Christian

16

Hot Ductility Behavior of Boron Containing Microalloyed Steels with Varying Manganese Contents  

NASA Astrophysics Data System (ADS)

The hot ductility is measured for six different steel grades with different microalloying elements and with varying manganese contents using the hot tensile test machine with melting/solidification unit at the Department of Ferrous Metallurgy RWTH Aachen University. To identify the influence of manganese on hot ductility, tests are performed with varying the manganese content from 0.7 to 18.2 wt pct, a high manganese steel. Additionally, the effect of different cooling and strain rates is analyzed by changing the particular rate for selected samples in the minima. To investigate and detect the cause of cracking during testing, the fracture surfaces in the ductility minima are considered with scanning electron microscope-energy dispersive X-ray spectroscopy. Thermodynamic modeling is conducted on basis of the commercial software ThermoCalc. A sharp decrease of the hot ductility is recognizable at 1398 K (1125 C), at only 0.7 wt pct manganese because of the low manganese to sulfur ratio. The grades with a Mn content up to 1.9 wt pct show a good ductility with minimal ductility loss. In comparison, the steel grade with 18.2 wt pct has a poor hot ductility. Because of the formation of complex precipitates, where several alloying elements are involved, the influence of boron on hot ductility is not fully clarified. By increasing the cooling rate, the reduction of area values are shifted to smaller values. For high test temperatures, these measured values are decreased for lower strain rates. Thereby, an early drop of the ductility is noticeable for the high temperatures around 1373 K (1100 C).

Brune, Tobias; Senk, Dieter; Walpot, Raphael; Steenken, Bernhard

2015-02-01

17

Fracture behavior of neutron-irradiated high-manganese austenitic steels  

NASA Astrophysics Data System (ADS)

The instrumented Charpy impact test was applied to study the fracture behavior of high-manganese austenitic steels before and after neutron irradiations. Quarter-size specimens of a commercial high-manganese steel (18% Mn-5% Ni-16% Cr), three reference steels (21% Mn-1% Ni-9% Cr, 20% Mn-1% Ni-11% Cr, 15% Mn-1% Ni-13% Cr) and two model steels (17% Mn-4.5% Si-6.5% Cr, 22% Mn-4.5% Si-6.5% Cr-0.2% N) were used for the impact tests at temperatures between 77 and 523 K. The load-deflection curves showed typical features corresponding to characteristics of the fracture properties. The temperature dependences of fracture energy and failure deflection obtained from the curves clearly demonstrate only small effects up to 2 10 23 n/m 2 ( E > 0.1 MeV) and brittleness at room temperature in 17% Mn-Si-Cr steel at 1.6 10 25 n/m 2 ( E > 0.1 MeV), while ductility still remains in 22%Mn-Si-Cr steel.

Yoshida, H.; Miyata, K.; Narui, M.; Kayano, H.

1991-03-01

18

Manganese  

MedlinePLUS

... iron, zincTaking calcium along with any of these minerals can decrease the amount of manganese that the body can take in.IP-6 (Phytic acid)IP-6 found in foods, such as cereals, nuts, and beans, and in supplements can decrease the amount of ...

19

Corrosion of stainless steel piping in a high manganese fresh water  

SciTech Connect

In March of 1993, about two years after startup in early 1991, pinhole leaks were found in the 16 in. (406 mm) type 304L stainless steel (UNS S30403) raw water piping at the Brunswick-Topsham Water District (BTWD) Potable Water Treatment Plant (PWTP) in Brunswick, Maine. The low chloride manganese-containing well water is chlorinated in the pump house. After reaching the plant, the raw water is handled in type 304L stainless steel (UNS S30403) piping. It was initially felt that the corrosion might be the microbiologically influenced corrosion (MIC) type corrosion described by Tverberg, Pinnow, and Redmerski. Investigation showed that the role of manganese and chlorine differed, in important respects, from that described by Tverberg et. al., and that heat tint scale may have played a significant role in the corrosion that occurred at the BTWD plant.

Avery, R.E. [Nickel Development Inst., Londonderry, NH (United States); Lutey, R.W. [Buckman Labs., Memphis, TN (United States); Musick, J. [Whitman and Howard, Portland, ME (United States); Pinnow, K.E. [Crucible Research, Pittsburgh, PA (United States); Tuthill, A.H. [Nickel Development Inst., Blacksburg, VA (United States)

1996-07-01

20

Manganese-stabilized austenitic stainless steels for fusion applications  

DOEpatents

An austenitic stainless steel that is comprised of Fe, Cr, Mn, C but no Ni or Nb and minimum N. To enhance strength and fabricability minor alloying additions of Ti, W, V, B and P are made. The resulting alloy is one that can be used in fusion reactor environments because the half-lives of the elements are sufficiently short to allow for handling and disposal.

Klueh, Ronald L. (Knoxville, TN); Maziasz, Philip J. (Oak Ridge, TN)

1990-01-01

21

Manganese biofouling of stainless steel: Deposition rates and influence on corrosion processes  

SciTech Connect

Corrosion potential (E{sub corr}) for 316L stainless steel coupons was monitored during 9 days in situ exposure to fresh river water. E{sub corr} increased at 300 mV day{sup {minus}1} reaching potentials of +350 mV (SCE) within 48 hours, then remained fixed at this potential. The coulometric reduction technique was used to determine rate and total abundance of cathodically active manganese biofouling during the exposure. A deposition rate of 0.57 mcoul cm{sup {minus}2} d{sup {minus}1} was measured during the initial 7 days, increasing to 3.1 mcoul cm{sup {minus}2} d{sup {minus}1} between day 7 and 9. Based on a one-electron reduction of MnO{sub 2} to MnOOH, 8.8 {micro}g cm{sup {minus}2} electroactive MnO{sub 2} was deposited during the 9 day exposure. Comparison with published data for manganese deposition in drinking water distribution systems suggests rapid biological MnO{sub 2} deposition consistent with the rapid rate of Ennoblement. Deposition rate is used to estimate the potential impact of manganese biofouling on stainless steel pitting.

Dickinson, W.H.; Lewandowski, Z. [Montana State Univ., Bozeman, MT (United States)

1996-11-01

22

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

NASA Astrophysics Data System (ADS)

The solidification structures and the thermal properties of Fe-Mn-C steel ingots containing different manganese contents have been investigated and the phase transformation characteristics have been revealed by Thermo-Calc to assist development of the continuous casting technology of Fe-Mn-C steels. The results show that the thermal conductivity of the 0Mn steel is higher than that of the 3Mn steel. The thermal conductivity of the 6Mn steel is the lowest in the three kinds of steels below 1023 K (750 C) and the highest above 1173 K (900 C). The 0Mn steel has the highest value of the proportion of equiaxed grain zone area in the three kinds of steels, whereas the 3Mn steel has the lowest value of it in the steels. Manganese has the effect of promoting the coarsening of grains. The microstructure is martensite and a little retained austenite (3.8 mass pct) in the 6Mn steel, whereas the microstructure is bainite in the 3Mn steel. The 0Mn steel is characterized by ferrite and pearlite. The mean thermal expansion coefficients of the steels are in the range from 1.0 10-5 to 1.6 10-5 K-1, and the determinations of mold tapers of the 6Mn and 3Mn steels can refer to low-carbon steel. Using RA <60 pct as the criterion, the third brittle temperature region of the 6Mn steel is 873 K to 1073 K (600 C to 800 C), whereas those of the 3Mn steel and the 0Mn steel are 873 K to 1123 K (600 C to 850 C) and 873 K to 1173 K (600 C to 900 C), respectively. In the 6Mn and 3Mn steels, the deformation-induced ferrite (DIF) forms in sufficient quantities cause the recovery of the ductility at the low temperature end. However, since low strains are present when straightening, sufficient quantities of DIF cannot be formed. Thus, the ductility of the 6Mn and 3Mn steels cannot be improved during the continuous casting process. Manganese has the effect of enlarging the austenite phase region and reducing the ?-ferrite phase region and ?-ferrite phase region.

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

2015-02-01

23

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). PMID:16535635

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

1997-01-01

24

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 Martn, D.; Palizdar, Y.; Garca-Mateo, C.; Cochrane, R. C.; Brydson, R.; Scott, A. J.

2011-09-01

25

Influence of explosive density on mechanical properties of high manganese steel explosion hardened  

NASA Astrophysics Data System (ADS)

The explosion hardening tests of high manganese steel were carried out by using two kinds of explosives of the same composition but different density, respectively. The detonation velocities were tested and the relevant mechanical properties were studied. The results show that the stronger single impulse acting on the specimen, the more hardness of surface increases and the more impact toughness decreases. Compared with the explosive of 1.48 g/cm3 density, the hardness, elongation rate, and impact toughness of the sample for triple explosion with explosive of 1.38 g/cm3 density are larger at the same hardening depth. In addition, the tensile strength of the sample for triple explosion with density of 1.38 g/cm3 is higher from the surface to 15 mm below the surface hardened.

Hu, Xiaoyan; Shen, Zhaowu; Liu, Yingbin; Liu, Tiansheng; Wang, Fengying

2013-12-01

26

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

27

Structure analysis of aluminium silicon manganese nitride precipitates formed in grain-oriented electrical steels  

SciTech Connect

We report a detailed structural and chemical characterisation of aluminium silicon manganese nitrides that act as grain growth inhibitors in industrially processed grain-oriented (GO) electrical steels. The compounds are characterised using energy dispersive X-ray spectrometry (EDX) and energy filtered transmission electron microscopy (EFTEM), while their crystal structures are analysed using X-ray diffraction (XRD) and TEM in electron diffraction (ED), dark-field, high-resolution and automated crystallographic orientation mapping (ACOM) modes. The chemical bonding character is determined using electron energy loss spectroscopy (EELS). Despite the wide variation in composition, all the precipitates exhibit a hexagonal close-packed (h.c.p.) crystal structure and lattice parameters of aluminium nitride. The EDX measurement of ? 900 stoichiometrically different precipitates indicates intermediate structures between pure aluminium nitride and pure silicon manganese nitride, with a constant Si/Mn atomic ratio of ? 4. It is demonstrated that aluminium and silicon are interchangeably precipitated with the same local arrangement, while both Mn{sup 2+} and Mn{sup 3+} are incorporated in the h.c.p. silicon nitride interstitial sites. The oxidation of the silicon manganese nitrides most likely originates from the incorporation of oxygen during the decarburisation annealing process, thus creating extended planar defects such as stacking faults and inversion domain boundaries. The chemical composition of the inhibitors may be written as (AlN){sub x}(SiMn{sub 0.25}N{sub y}O{sub z}){sub 1?x} with x ranging from 0 to 1. - Highlights: We study the structure of (Al,Si,Mn)N inhibitors in grain oriented electrical steels. Inhibitors have the hexagonal close-packed symmetry with lattice parameters of AlN. Inhibitors are intermediate structures between pure AlN and (Si,Mn)N with Si/Mn ? 4. Al and Si share the same local arrangement; Mn is incorporated in both Mn{sup 2+} and Mn{sup 3+}. Oxygen incorporation is invoked to account for the thermal stability of (Al,Si,Mn)N.

Bernier, Nicolas, E-mail: n.bernier@yahoo.fr [OCAS N.V., ArcelorMittal Global R and D Gent, Pres. J.F. Kennedylaan 3, 9060 Zelzate (Belgium); Xhoffer, Chris [OCAS N.V., ArcelorMittal Global R and D Gent, Pres. J.F. Kennedylaan 3, 9060 Zelzate (Belgium); Van De Putte, Tom, E-mail: tom.vandeputte@arcelormittal.com [OCAS N.V., ArcelorMittal Global R and D Gent, Pres. J.F. Kennedylaan 3, 9060 Zelzate (Belgium); Galceran, Montserrat [Universit Libre de Bruxelles, 4MAT (Materials Engineering, Characterization, Synthesis and Recycling), Avenue F.D. Roosevelt 50, 1050 Brussels (Belgium); CIC Energigune, Albert Einstein 48, 01510 Miano (lava) (Spain); Godet, Stphane [Universit Libre de Bruxelles, 4MAT (Materials Engineering, Characterization, Synthesis and Recycling), Avenue F.D. Roosevelt 50, 1050 Brussels (Belgium)

2013-12-15

28

COLORIMETRIC DETERMINATION OF MANGANESE  

E-print Network

1 COLORIMETRIC DETERMINATION OF MANGANESE (Chemistry 51 Version) The objective of this experiment is to determine the percentage of manganese in a steel sample, using colorimetric methods of analysis. PRINCIPLES This analysis is accomplished by dissolving the steel sample, converting all of the manganese to the intensely

Bertsch George F.

29

Manganese Intoxication  

PubMed Central

We have reported two cases of chronic manganese poisoning. Case 1 followed exposure to manganese fumes in cutting and burning manganese steel. Case 2 resulted from exposure to dusts of manganese dioxide, an ingredient used in glazing of ceramics. There were initial difficulties in establishing the correct diagnosis. Prominent clinical features were severe and persistent chronic depressive psychosis (Case 1), transient acute brain syndrome (Case 2) and the presence of various extrapyramidal symptoms in both cases. Manganese intoxication has not previously been reported as occurring in California. With increasing use of the metal, the disease should be considered in the differential diagnosis of neurologic and psychiatric disease. Our observations were made in the period 1964 through 1968. Recently the prognosis of victims of manganese poisoning has been improved dramatically by the introduction of levodopa as a therapeutic agent. PMID:1179714

Hine, Charles H.; Pasi, Aurelio

1975-01-01

30

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.; Kmmelt, P.; Sietsma, J.

2013-10-01

31

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

Code of Federal Regulations, 2010 CFR

...carbon-manganese-alloy steel, manganese-vanadium-alloy steel, and carbon-silicon steel may...carbon-molybdenum, manganese-molybdenum-vanadium, manganese-chromium-vanadium, and chromium-vanadium, may convert to...

2010-10-01

32

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

Code of Federal Regulations, 2013 CFR

...carbon-manganese-alloy steel, manganese-vanadium-alloy steel, and carbon-silicon steel may...carbon-molybdenum, manganese-molybdenum-vanadium, manganese-chromium-vanadium, and chromium-vanadium, may convert to...

2013-10-01

33

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

Code of Federal Regulations, 2012 CFR

...carbon-manganese-alloy steel, manganese-vanadium-alloy steel, and carbon-silicon steel may...carbon-molybdenum, manganese-molybdenum-vanadium, manganese-chromium-vanadium, and chromium-vanadium, may convert to...

2012-10-01

34

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

Code of Federal Regulations, 2011 CFR

...carbon-manganese-alloy steel, manganese-vanadium-alloy steel, and carbon-silicon steel may...carbon-molybdenum, manganese-molybdenum-vanadium, manganese-chromium-vanadium, and chromium-vanadium, may convert to...

2011-10-01

35

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

Code of Federal Regulations, 2014 CFR

...carbon-manganese-alloy steel, manganese-vanadium-alloy steel, and carbon-silicon steel may...carbon-molybdenum, manganese-molybdenum-vanadium, manganese-chromium-vanadium, and chromium-vanadium, may convert to...

2014-10-01

36

Welding fumes from stainless steel gas metal arc processes contain multiple manganese chemical species.  

PubMed

Fumes from a group of gas metal arc welding (GMAW) processes used on stainless steel were generated using three different metal transfer modes and four different shield gases. The objective was to identify and measure manganese (Mn) species in the fumes, and identify processes that are minimal generators of Mn species. The robotic welding system was operated in short-circuit (SC) mode (Ar/CO2 and He/Ar), axial spray (AXS) mode (Ar/O2 and Ar/CO2), and pulsed axial-spray (PAXS) mode (Ar/O2). The fumes were analyzed for Mn by a sequential extraction process followed by inductively coupled plasma-atomic emission spectroscopy (ICP-AES) analysis, and by X-ray diffraction (XRD). Total elemental Mn, iron (Fe), chromium (Cr) and nickel (Ni) were separately measured after aqua regia digestion and ICP-AES analysis. Soluble Mn2+, Fe2+, Fe3+, and Ni2+ in a simple biological buffer (phosphate-buffered saline) were determined at pH 7.2 and 5.0 after 2 h incubation at 37 C by ion chromatography. Results indicate that Mn was present in soluble form, acid-soluble form, and acid-soluble form after reduction by hydroxylamine, which represents soluble Mn0 and Mn2+ compounds, other Mn2+ compounds, and (Mn3+ and Mn4+) compounds, respectively. The dominant fraction was the acid-soluble Mn2+ fraction, but results varied with the process and shield gas. Soluble Mn mass percent in the fume ranged from 0.2 to 0.9%, acid-soluble Mn2+ compounds ranged from 2.6 to 9.3%, and acid plus reducing agent-soluble (Mn3+ and Mn4+) compounds ranged from 0.6 to 5.1%. Total Mn composition ranged from 7 to 15%. XRD results showed fumes had a crystalline content of 90-99% Fe3O4, and showed evidence of multiple Mn oxides, but overlaps and weak signals limited identification. Small amounts of the Mn2+ in the fume (<0.01 to ? 1% or <0.1 to ? 10 microg ml(-1)) and Ni2+ (<0.01 to ? 0.2% or <0.1 to ? 2 mg ml(-1)) ions were found in biological buffer media, but amounts were highly dependent on pH and the welding process. Mn generation rates for the fractions were tabulated, and the influence of ozone is discussed. The conclusions are that exposures to welding fumes include multiple Mn species, both soluble and insoluble, and that exposures to Mn species vary with specific processes and shield gases. PMID:21491680

Keane, Michael; Stone, Samuel; Chen, Bean

2010-05-01

37

Investigations on Laser Beam Welding Dissimilar Material Combinations of Austenitic High Manganese (FeMn) and Ferrite Steels  

NASA Astrophysics Data System (ADS)

For the past few years the customer's demand for more fuel efficient and at the same time safer vehicles has steadily increased. Consequently, light weight design has become one of the main interests in engineering. With regard to sheet metal components, a new class of high manganese steels, based on the TWIP (twinning induced plasticity) effect, provides the opportunity of shaping light weight designedthin and complex sheet metal geometries with advanced crash performance. In terms of weldability, due to their thermo-physical properties (high content of C, Mn, Al, Si), FeMn steels have to be handled differently in comparison to conventional steel grades. Particularly dissimilar material combinations of FeMn and ferrite steels are in the center of interest for industrial applications. This study reveals that metallurgical properties of dissimilar welding seams can be influenced considerably by laser beam welding, resulting in a change of the mechanical properties of the seam which is practicable without using filler material as described in (Flgge et al., 2011).

Behm, Velten; Hfemann, Matthias; Hatscher, Ansgar; Springer, Andr; Kaierle, Stefan; Hein, David; Otto, Manuel; Overmeyer, Ludger

38

Study on the growth and corrosion resistance of manganese phosphate coatings on 30CrMnMoTi alloy steel  

NASA Astrophysics Data System (ADS)

Due to containing some alloy elements such as chromium, 30CrMnMoTi steel is usually difficult to be phosphated. In present paper, the growth process of the phosphate coating on 30CrMnMoTi alloy steel fabricated by a high temperature manganese phosphating was investigated. The microstructure, surface morphology, composition and corrosion resistance of the phosphate coatings were analyzed by XRD, SEM, EDS and electrochemical polarization method, respectively. The time dependence of open circuit potential (OCP) and the weight of the coating were also measured. It is found that the phosphate coating is mainly composed of (Mn,Fe)5H2(PO4)44H2O and consists of a lot of close packed lump crystallites. Based on the time dependence of morphology and the weight of phosphate films, it shows that the phosphating process mainly includes three stages: corrosion of the substrate, creation and growth of phosphate crystal nucleus and thickening of phosphate coating. For 30CrMnMoTi steel, it takes at least 30 seconds and 3 minutes for the first and second step, respectively: at the beginning stage of phospahting process, a lot of bubbles emit, then a complete film will form at the end of bubbling, and the nucleation of phosphate film is inhomogeneous, phosphate crystal nucleus usually forms preferentially at grain boundary. The coating weight-time curve is similar to that of the parabolic growth. The electrochemical polarization measurement shows that the corrosion potentials of the phosphated steel shifted positively about 480 mV than the bare steel and the results of neutral salt spray test (NSS) could reach 24 h, indicating the phosphating improved the corrosion resistance of the 30CrMnMoTi alloy steel.

Fang, Liang; Xie, Liang-bo; Hu, Jia; Li, Yun; Zhang, Wen-ting

39

Armor - preliminary study of the effect of several alloying elements and addition agents upon the metallurgical properties of manganese-molybdenum steel used in armor  

Microsoft Academic Search

The purpose of this study is to determine the effect of small amounts of tin, titanium, tellurium, selenium, zirconium, niobium, boron, and four commercial types of addition agents on the hardenability, V-notched Charpy impact properties, physical properties, and microstructure of a 0.30% carbon manganese-molybdenum type of steel.

Riffin

1943-01-01

40

Nitrogen distribution in austenitic high-nitrogen chromium-manganese steel under friction and high-pressure torsion  

NASA Astrophysics Data System (ADS)

Mssbauer spectroscopy and electron microscopic analysis were used to investigate the precipitation of products of cellular decomposition and their dissolution in high-nitrogen chromium-manganese steel FeMn22Cr18N0.8 under room-temperature severe deformation via dry sliding friction and high pressure torsion in Bridgman anvils. It has been established that the nitrogen content increases in interstitial positions in the quenched and pre-aged alloy due to the strain-induced dissolution of chromium nitrides, which are contained in the products of decomposition. Mssbauer analysis showed that the friction-induced dissolution of chromium nitrides occurs at a depth of more than 10 ?m. Aging reduces the amount of nitrogen that occurred in the solid solution upon deformation. This is explained by the additional energy consumed in grinding the decomposition products.

Shabashov, V. A.; Korshunov, L. G.; Sagaradze, V. V.; Kataeva, N. V.; Zamatovskii, A. E.; Litvinov, A. V.; Lyashkov, K. A.

2013-08-01

41

Effect of Grain Refinement on the Mechanical Properties of a Nickel- and Manganese-Free High Nitrogen Austenitic Stainless Steel  

NASA Astrophysics Data System (ADS)

Grain coarsening due to the high temperature exposure deteriorates mechanical properties of the high nitrogen austenitic stainless steels (HNASSs) produced by solution nitriding. To improve mechanical properties, the grains of nickel and manganese-free Fe-23Cr-2.4Mo-1.2N HNASS plates fabricated by pressurized solution nitriding were refined using a two-stage heat treatment process. Structural and mechanical properties were investigated using X-ray diffraction, optical microscopy, scanning and transmission electron microscopy, hardness and tensile testing and compared with that of the conventional AISI 316L steel. The results show that the as-produced HNASS exhibits uniform deformation up to failure without necking and brittle inter-granular fracture. By grain refinement, the yield and tensile strengths as well as the elongation to failure are increased by 17.8, 21.2, and 108.3 pct, respectively, as compared to the as-produced HNASS. However, despite more than a double increase in tensile toughness and elongation to failure, the brittle inter-granular fracture is not suppressed. The HNASSs plastically deform through formation of straight slip bands. TEM observations indicate development of planar arrays of dislocations in tensile-deformed HNASSs. The enhancement in tensile strength and toughness by grain refinement is discussed on the basis of straight slip bands formation, number of dislocations in pile-ups, and incompatibility strain developed between adjacent grains.

Akbari, Alireza; Mohammadzadeh, Roghayeh

2015-04-01

42

Effect of Grain Refinement on the Mechanical Properties of a Nickel- and Manganese-Free High Nitrogen Austenitic Stainless Steel  

NASA Astrophysics Data System (ADS)

Grain coarsening due to the high temperature exposure deteriorates mechanical properties of the high nitrogen austenitic stainless steels (HNASSs) produced by solution nitriding. To improve mechanical properties, the grains of nickel and manganese-free Fe-23Cr-2.4Mo-1.2N HNASS plates fabricated by pressurized solution nitriding were refined using a two-stage heat treatment process. Structural and mechanical properties were investigated using X-ray diffraction, optical microscopy, scanning and transmission electron microscopy, hardness and tensile testing and compared with that of the conventional AISI 316L steel. The results show that the as-produced HNASS exhibits uniform deformation up to failure without necking and brittle inter-granular fracture. By grain refinement, the yield and tensile strengths as well as the elongation to failure are increased by 17.8, 21.2, and 108.3 pct, respectively, as compared to the as-produced HNASS. However, despite more than a double increase in tensile toughness and elongation to failure, the brittle inter-granular fracture is not suppressed. The HNASSs plastically deform through formation of straight slip bands. TEM observations indicate development of planar arrays of dislocations in tensile-deformed HNASSs. The enhancement in tensile strength and toughness by grain refinement is discussed on the basis of straight slip bands formation, number of dislocations in pile-ups, and incompatibility strain developed between adjacent grains.

Akbari, Alireza; Mohammadzadeh, Roghayeh

2015-01-01

43

High Manganese and Aluminum Steels for the Military and Transportation Industry  

NASA Astrophysics Data System (ADS)

Lightweight advanced high strength steels (AHSS) with aluminum contents between 4 and 12 weight percent have been the subject of intense interest in the last decade because of an excellent combination of high strain rate toughness coupled with up to a 17% reduction in density. Fully austenitic cast steels with a nominal composition of Fe-30%Mn-9%Al-0.9%C are almost 15% less dense than quenched and tempered Cr-Mo steels (SAE 4130) with equivalent strengths and dynamic fracture toughness. This article serves as a review of the tensile and high-strain-rate fracture properties associated mainly with silicon additions to this base composition. In the solution-treated condition, cast steels have high work-hardening rates with elongations up to 64%, room-temperature Charpy V-notch (CVN) impact energies up to 200 J, and dynamic fracture toughness over 700 kJ/m2. Silicon additions in the range of 0.59-1.56% Si have no significant effect on the mechanical properties of solution-treated steels but increased the tensile strength and hardness during aging. For steels aged at 530C to an average hardness of 310 Brinell hardness number, HBW, increasing the amount of silicon from 1.07% to 1.56% decreased the room temperature CVN breaking energy from 92 J to 68 J and the dynamic fracture toughness from 376 kJ/m2 to 265 kJ/m2. Notch toughness is a strong function of phosphorus content, decreasing the solution-treated CVN impact toughness from 200 J in a 0.006% P steel to 28 J in a 0.07% P steel. For age-hardened steels with 1% Si, increasing levels of phosphorus from 0.001% to 0.043% decreased the dynamic fracture toughness from 376 kJ/m2 to 100 kJ/m2.

Bartlett, Laura; Van Aken, David

2014-09-01

44

Evolution of Nickel-Manganese-Silicon Dominated Phases in Highly Irradiated Reactor Pressure Vessel Steels  

SciTech Connect

Formation of a high density of Ni-Mn-Si nm-scale precipitates in irradiated reactor pressure vessel steels, both with and without Cu, could lead to severe embrittlement. Models long ago predicted that these precipitates, which are not treated in current embrittlement regulations, would emerge only at high fluence. However, the mechanisms and variables that control Ni-Mn- Si precipitate formation, and their detailed characteristics, have not been well understood. High flux irradiations of six steels with systematic variations in Cu and Ni were carried out at 2955C to high and very high neutron fluences of 1.3x1020 and 1.1x1021 n/cm2. Atom probe tomography (APT) shows that significant mole fractions of these precipitates form in the Cu bearing steels at 1.3x1020 n/cm2, while they are only beginning to develop in Cu-free steels. However, large mole fractions, far in excess of those found in previous studies, are observed at 1.1x1021 n/cm2 at all Cu levels. The precipitates diffract, and in one case are compositionally and structurally consistent with the Mn6Ni16Si7 G-phase. At the highest fluence, the large precipitate mole fractions primarily depend on the steel Ni content, rather than Cu, and lead to enormous strength increases up to about 700 MPa. The implications of these results to light water reactor life extension are discussed briefly.

Peter B Wells; Yuan Wu; Tim Milot; G. Robert Odette; Takuya Yamamoto; Brandon Miller; James Cole

2014-11-01

45

Carbon determination in carbon-manganese steels under atmospheric conditions by Laser-Induced Breakdown Spectroscopy.  

PubMed

The most sensitive lines of carbon, used nowadays for its determination in steels by laser-induced-breakdown spectroscopy (LIBS), are at vacuum UV and, thereby, LIBS potential is significantly reduced. We suggested the use of the C I 833.51 nm line for carbon determination in low-alloy steels (c(C)~0.186-1.33 wt.%) in air. Double-pulse LIBS with the collinear scheme was performed for maximal enhancement of a carbon emission signal without substantial complication of experimental setup. Since this line is strongly broadened in laser plasma, it overlapped with the closest iron lines greatly. We implemented a PCR method for the construction of a multivariate calibration model under spectral interferences. The model provided a RMSECV = 0.045 wt.%. The predicted carbon content in the rail templet was in an agreement with the reference value obtained by a combustion analyzer within the relative error of 6%. PMID:25321709

Labutin, Timur A; Zaytsev, Sergey M; Popov, Andrey M; Zorov, Nikita B

2014-09-22

46

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

47

MANGANESE--1997 49.1 By Thomas S. Jones  

E-print Network

MANGANESE--1997 49.1 MANGANESE By Thomas S. Jones Manganese (Mn) is essential to iron and steel,includingitsironmakingcomponent,hasaccounted for most domestic manganese demand, presently in the range of 85% to 90% of the total demand. Among a variety of other uses, manganese is a key component of certain widely used aluminum alloys and is used

Torgersen, Christian

48

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

49

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

50

MANGANESE--1999 49.1 By Thomas S. Jones  

E-print Network

MANGANESE--1999 49.1 MANGANESE By Thomas S. Jones Domestic survey data and tables were prepared. Wallace, international data coordinators. Manganese (Mn) is essential to iron and steel production component, has accounted for most domestic manganese demand, presently in the range of 85% to 90

Torgersen, Christian

51

MANGANESE--2000 50.1 By Thomas S. Jones  

E-print Network

MANGANESE--2000 50.1 MANGANESE By Thomas S. Jones Domestic survey data and tables were prepared. Wallace, international data coordinator. Manganese (Mn) is essential to iron and steel production component, has accounted for most domestic manganese demand, presently in the range of 85% to 90

Torgersen, Christian

52

MANGANESE--2001 49.1 By Lisa A. Corathers  

E-print Network

MANGANESE--2001 49.1 MANGANESE By Lisa A. Corathers Domestic survey data and tables were prepared. Wallace, international data coordinator. Manganese is essential to iron and steel production by virtue component, has accounted for most domestic manganese demand, presently in the range of 85% to 90

Torgersen, Christian

53

MANGANESE--1998 49.1 By Thomas S. Jones  

E-print Network

MANGANESE--1998 49.1 MANGANESE By Thomas S. Jones Domestic survey data and tables were prepared. Wallace, international data coordinator. Manganese is essential to iron and steel production by virtue component, has accounted for most domestic manganese demand, presently in the range of 85% to 90

Torgersen, Christian

54

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

2013-08-01

55

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

56

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

57

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

58

Mineral of the month: manganese  

USGS Publications Warehouse

Manganese is one of the most important ferrous metals and one of the few for which the United States is totally dependent on imports. It is a black, brittle element predominantly used in metallurgical applications as an alloying addition, particularly in steel and cast iron production, which together provide the largest market for manganese (about 83 percent). It is also used as an alloy with nonferrous metals such as aluminum and copper. Nonmetallurgical applications of manganese include battery cathodes, soft ferrite magnets used in electronics, micronutrients found in fertilizers and animal feed, water treatment chemicals, and a colorant for bricks and ceramics.

Corathers, Lisa

2005-01-01

59

Heat treatment effects on the microstructure and mechanical properties of a medium manganese steel (0.2C-5Mn)  

Microsoft Academic Search

Microstructures and mechanical properties of 0.2C-5Mn steel processed under different heat treatment conditions were examined by scanning electron microscopy (SEM), Transmission electron microscopy (TEM) and x-rays diffraction (XRD). It was found that high temperature austenization (above Ac3) resulted in a full martensite structure after quenching, which gradually transformed into the ferrite\\/austenite duplex structure during the following annealing process. However, austenization

H. F. Xu; J. Zhao; W. Q. Cao; J. Shi; C. Y. Wang; J. Li; H. Dong

60

Dynamics of phase transformations and microstructure evolution in carbon-manganese steel arc welds using time-resolved synchrotron X-ray diffraction.  

PubMed

Phase transformations that occur in both the heat-affected zone (HAZ) and the fusion zone (FZ) of a carbon-manganese steel spot weld have been investigated using time-resolved X-ray diffraction (TRXRD) with time resolutions down to 50 ms. It is found that in both zones the gamma(f.c.c.) --> alpha(b.c.c.) transformation on cooling is twice as fast as the forward transformation of alpha --> gamma on heating. Profile analysis of the major Bragg reflections recorded in the TRXRD patterns reveals similarities and differences in the microstructural evolution with time in the HAZ and in the FZ. The latter undergoes melting and solidification in addition to solid-state transformations. With increasing temperature, the (110) d-spacing of the alpha phase prior to and during the alpha --> gamma transformation and the (111) d-spacing of the gamma phase just after the same transformation exhibit a decrease. The observed (and unusual) lattice contraction with temperature rise may be attributed to chemical effects, such as carbide precipitation in the alpha matrix, and/or mechanical effects due to stress relief. In the FZ, the gamma-Fe that forms has a preferential (200) texture on solidification of the liquid, whereas, on cooling in the HAZ, the gamma-Fe retains largely a (111) texture that is induced in the alpha --> gamma transformation on heating. On cooling in the HAZ, the width of the gamma(111) reflection increases initially, which is indicative of microstrain developing in the f.c.c. lattice, but decreases as expected, with a reduction of thermal disorder, on further cooling until the completion of the gamma --> alpha transformation. In the FZ, however, the microstrain in the gamma phase increases steadily on solidification and more rapidly for the duration of the gamma --> alpha transformation on further cooling. The final microstructure of the FZ is likely to consist of a single alpha phase dispersed in two morphological entities, whereas in the HAZ the alpha phase persists in one morphological entity in the final microstructure. PMID:12606794

Wong, Joe; Ressler, Thorsten; Elmer, John W

2003-03-01

61

Manganese encephalopathy: utility of early magnetic resonance imaging.  

PubMed Central

The use of magnetic resonance imaging (MRI) provides visual evidence of cerebral deposits of paramagnetic metals. The usefulness of MRI is described in connection with the manganese poisoning of a 44 year old arc welder who had been engaged in the repair and recycling of railroad track made of manganese steel alloy. Images PMID:8329316

Nelson, K; Golnick, J; Korn, T; Angle, C

1993-01-01

62

Manganese encephalopathy: utility of early magnetic resonance imaging  

Microsoft Academic Search

The use of magnetic resonance imaging (MRI) provides visual evidence of cerebral deposits of paramagnetic metals. The usefulness of MRI is described in connection with the manganese poisoning of a 44 year old arc welder who had been engaged in the repair and recycling of railroad track made of manganese steel alloy.

K Nelson; J Golnick; T Korn; C Angle

1993-01-01

63

Autonomic function in manganese alloy workers  

SciTech Connect

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 grinding repair of high manganese railway track and a convenience sample of three mild steel welders with lesser manganese exposure also referred because of cognitive or autonomic symptoms. Frog shop air manganese samples 9.6--10 years before and 1.2--3.4 years after the diagnosis of the index case exceeded 1.0 mg/m{sup 3} in 29% and 0.2 mg/m{sup 3} in 62%. Twenty-four-hour electrocardiographic (Holter) monitoring was used to determine the temporal variability of the heartrate (RR{prime} interval) and the rates of change at low frequency and high frequency. MMPI and MCMI personality assessment and short-term memory, figure copy, controlled oral word association, and symbol digit tests were used.

Barrington, W.W.; Angle, C.R.; Willcockson, N.K.; Padula, M.A. [Univ. of Nebraska Medical Center, Omaha, NE (United States)] [Univ. of Nebraska Medical Center, Omaha, NE (United States); Korn, T.

1998-07-01

64

Chronic manganese intoxication  

SciTech Connect

We report six cases of chronic manganese intoxication in workers at a ferromanganese factory in Taiwan. Diagnosis was confirmed by assessing increased manganese concentrations in the blood, scalp, and pubic hair. In addition, increased manganese levels in the environmental air were established. The patients showed a bradykinetic-rigid syndrome indistinguishable from Parkinson's disease that responded to treatment with levodopa.

Huang, C.C.; Chu, N.S.; Lu, C.S.; Wang, J.D.; Tsai, J.L.; Tzeng, J.L.; Wolters, E.C.; Calne, D.B. (Chang Gung Medical College Hospital, Taipei, Taiwan (China))

1989-10-01

65

Globally sustainable manganese metal production and use.  

PubMed

The "cradle to grave" concept of managing chemicals and wastes has been a descriptive analogy of proper environmental stewardship since the 1970s. The concept incorporates environmentally sustainable product choices-such as metal alloys utilized steel products which civilization is dependent upon. Manganese consumption is related to the increasing production of raw steel and upgrading ferroalloys. Nonferrous applications of manganese include production of dry-cell batteries, plant fertilizer components, animal feed and colorant for bricks. The manganese ore (high grade 35% manganese) production world wide is about 6 million ton/year and electrolytic manganese metal demand is about 0.7 million ton/year. The total manganese demand is consumed globally by industries including construction (23%), machinery (14%), and transportation (11%). Manganese is recycled within scrap of iron and steel, a small amount is recycled within aluminum used beverage cans. Recycling rate is 37% and efficiency is estimated as 53% [Roskill Metals and Minerals Reports, January 13, 2005. Manganese Report: rapid rise in output caused by Chinese crude steel production. Available from: http://www.roskill.com/reports/manganese.]. Environmentally sustainable management choices include identifying raw material chemistry, utilizing clean production processes, minimizing waste generation, recycling materials, controlling occupational exposures, and collecting representative environmental data. This paper will discuss two electrolytically produced manganese metals, the metal production differences, and environmental impacts cited to date. The two electrolytic manganese processes differ due to the addition of sulfur dioxide or selenium dioxide. Adverse environmental impacts due to use of selenium dioxide methodology include increased water consumption and order of magnitude greater solid waste generation per ton of metal processed. The use of high grade manganese ores in the electrolytic process also reduces the quantity of solid wastes generated during processing. Secondary aluminum facilities have reported hazardous waste generation management issues due to baghouse dusts from rotary furnaces processing selenium contaminated manganese alloys. Environmental impacts resulting from industry are represented by emission inventories of chemical releases to the air, water, and soil. The U.S. metals industry releases reported to EPA Toxic Release Inventory indicate the primary metals industry is the major source of metal air toxic emissions, exceeding electric utility air toxic emissions. The nonferrous metals industry is reported to be the Organization for Economic Co-operation and Development (OECD) most intensive airborne and land pollution source of bioaccumulative metals. However, total waste emissions from industries in the OECD countries have declined due to improving energy consumption. Emission registers and access are improving around the world. However, environmental databases for metal particulates have low confidence ratings since the majority of air toxic emissions are not reported, not monitored, or are estimated based on worst-case emission factors. Environmental assessments including biological monitoring are necessary to validate mandated particulate metal emission reductions and control technologies during metal processing. PMID:19467569

Hagelstein, Karen

2009-09-01

66

Manganese laser using manganese chloride as lasant  

NASA Technical Reports Server (NTRS)

A manganese vapor laser utilizing manganese chloride as a lasant has been observed and investigated. Lasing is attained by means of two consecutive electrical discharges. The maximum laser output is obtained at a vapor pressure of about 3 torr, a temperature of 680 C, and a time delay between electrical discharges of 150 microsec. The maximum energy density is 1.3 microjoule per cu cm.

Chen, C. J.

1974-01-01

67

Manganese 2 -Complexes as Auxiliaries  

E-print Network

Manganese 2 -Complexes as Auxiliaries for Stereoselective Aldol Synthesis of Allenyl Carbinols manganese auxiliary was linked via an 2 -bond to alkynyl esters and ketones using a mild complexation reaction with methylcyclopentadienyl manganese tricarbonyl. This complex readily underwent aldol reactions

Lepore, Salvatore D.

68

Effect of non-magnetic inclusions in magnetic specimens on defect detection sensitivity using active infrared thermography  

NASA Astrophysics Data System (ADS)

We study the effect of non-magnetic inclusions in the defect regions on defect detection sensitivity using alternating magnetic field assisted infrared thermography. The effect of inclusions on the resulting surface temperature profiles around the defect regions are monitored using infrared thermography under the magnetic excitation. Four mild steel specimens with simulated rectangular slots of depths 8.0, 3.3, 3.0 and 5.0 mm, filled with three different non-magnetic inclusions, viz. clay, grease and wax are studied. Under an alternating magnetic field excitation, the induced eddy current in the mild steel specimens produces Joule's heating on the surfaces, which is monitored in a non-contact way. As the non-magnetic inclusions act as a thermal insulator to the alternating magnetization induced heating, a clear thermal contrast at the defect boundaries is seen. The defect regions are clearly discernible from the thermal images and defect widths are estimated from the horizontal temperature profiles. It is observed that the temperature difference between the defect and defect-free regions initially decreases with time up to a certain time (called inversion time) and beyond that the temperature difference increases with time for clay and grease filled defects. The peak temperature difference between the defect and defect-free regions decreases with defect depth due to the magnetic flux leakage from the defect regions. The normalized temperature decay rate, determined from the blind sides of the specimens, is found to decrease with the defect depth. The sensitivity of the depth estimation procedure is higher for inclusions with lower thermal diffusivity values. This study shows the efficacy of low frequency alternating magnetic field induced heating procedure for the detection of defects filled with non-magnetic inclusions in magnetic specimens using active infrared thermography.

Lahiri, B. B.; Bagavathiappan, S.; Sebastian, Libins T.; Philip, John; Jayakumar, T.

2015-01-01

69

BIOLOGICAL EFFECTS OF MANGANESE  

EPA Science Inventory

The biological effects of manganese were studied in a town on the coast of Dalmatia in which a ferromanganese plant has been operating since before World War II. The study focused on the question of whether the exposure to manganese can cause a higher incidence of respiratory dis...

70

Trip steels A new class of high-strength steels with high plasticity  

Microsoft Academic Search

TRIP steels are alloyed with molybdenum, chromium, nickel, manganese, vanadium, niobium, tantalum, tungsten, silicon, nitrogen, and carbon. The patent indicates that the steels must contain at least 1% of all the following alloying elements: Mo, Mn, Cr, V, Nb, Ta, W. The total carbon and nitrogen concentration amounts to 0.2-0.5%. The patent lists the following typical compositions of the steels:

I. Ya. Georgieva

1976-01-01

71

The effect of manganese additions on the reactive evaporation of chromium in NiCr 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

72

Occupational exposure to manganese.  

PubMed Central

The relationship between the degree of exposure and biological effects of manganese was studied in a group of 369 workers employed in the production of ferroalloys. Two other groups of workers, from an electrode plant and from an aluminium rolling mill, served as controls. Mean manganese concentrations at work places where ferroalloys were produced varied from 0-301 to 20-442 mg/m3. The exposure level of the two control groups was from 2 to 30 microgram/m3 and from 0-05 to 0-07 microgram/m3, in the electrode plant and rolling mill respectively. Sixty-two (16-8%) manganese alloy workers showed some signs of neurological impairment. These signs were noticeably less in the two control groups (5-8% and 0%) than in the occupationally exposed group. Subjective symptoms, which are nonspecific but may be symptoms of subclinical manganism, were not markedly different in the three groups. However, in the manganese alloy workers some of the subjective symptoms occurred more frequently in heavier smokers than in light smokers or nonsmokers. Heavier smokers engaged in manganese alloy production showed some of the subjective symptoms more often than heavier smokers from the control groups. PMID:871441

Sari?, M; Marki?evi?, A; Hrusti?, O

1977-01-01

73

Recent developments in manganese speciation  

Microsoft Academic Search

Manganese is an abundant element in the environment and widely used throughout industry. Although manganese has relatively low toxicity, in chronic overdose or prolonged occupational exposure, it can cause severe disruption to the central nervous system. This article illustrates the requirements for manganese speciation and reviews the analytical methods applied to such studies, including electroanalytical techniques and hybrid systems, such

Gareth F. Pearson; Gillian M. Greenway

2005-01-01

74

Non-Magnetic, Tough, Corrosion- and Wear-Resistant Knives From Bulk Metallic Glasses and Composites  

NASA Technical Reports Server (NTRS)

Quality knives are typically fabricated from high-strength steel alloys. Depending on the application, there are different requirements for mechanical and physical properties that cause problems for steel alloys. For example, diver's knives are generally used in salt water, which causes rust in steel knives. Titanium diver's knives are a popular alternative due to their salt water corrosion resistance, but are too soft to maintain a sharp cutting edge. Steel knives are also magnetic, which is undesirable for military applications where the knives are used as a tactical tool for diffusing magnetic mines. Steel is also significantly denser than titanium (8 g/cu cm vs. 4.5 g/cu cm), which results in heavier knives for the same size. Steel is hard and wear-resistant, compared with titanium, and can keep a sharp edge during service. A major drawback of both steel and titanium knives is that they must be ground or machined into the final knife shape from a billet. Since most knives have a mirrored surface and a complex shape, manufacturing them is complex. It would be more desirable if the knife could be cast into a net or near-net shape in a single step. The solution to the deficiencies of titanium, steel, and ceramic knives is to fabricate them using bulk metallic glasses (or composites). These alloys can be cast into net or near-net shaped knives with a combination of properties that exceed both titanium and steel. A commercially viable BMG (bulk metallic glass) or composite knife is one that exhibits one or all of the following properties: It is based on titanium, has a self-sharpening edge, can retain an edge during service, is hard, is non-magnetic, is corrosion-resistant against a variety of corrosive environments, is tough (to allow for prying), can be cast into a net-shape with a mirror finish and a complex shape, has excellent wear resistance, and is low-density. These properties can be achieved in BMG and composites through alloy chemistry and processing. For each desired property for knife fabrication and performance, there is an alloy development strategy that optimizes behavior. Although BMG knives have been demonstrated as far back as 1995, they never found commercial success because they had to be ground (which presented problems because the alloys contained beryllium), they weren't low cost (because they weren't cast to a net-shape), they were brittle (because they were made with a low-quality commercial material), and they had extremely poor corrosion resistance (because corrosion was not well-understood in these materials). Ultimately, these shortcomings prevented the widespread commercialization. In the current work, the inventors have applied more than a decade of research on BMGs from Caltech and JPL to develop a better understanding of how to make BMG knives that exhibit an optimal combination of properties, processing and cost. Alloys have been developed based in titanium (and other metals), that exhibit high toughness, high hardness, excellent corrosion resistance, no ferromagnetism, edge-retaining selfsharpening, and the ability to be cast like a plastic using commercially available casting techniques (currently used by commercial companies such as Liquidmetal Technologies and Visser Precision Casting). The inventors argue that depending on the application (diving, military, tactical, utility, etc.) there is an optimal combination of design and alloy composition. Moreover, with new casting technologies not available at the inception of these materials, net-shaped knives can be cast into complex shapes that require no aftermarket forming, except for sharpening using water-cooled polishing wheel. These combinations of discoveries seek to make low-cost BMG knives commercially viable products that have no equal among metal or ceramic knives. Current work at JPL focuses on net-shape casting of these alloys and testing their mechanical properties versus commercially available knives to demonstrate their benefits.

Hoffman, Douglas C.; Potter, Benjamin

2013-01-01

75

Low Mn alloy steel for cryogenic service and method of preparation  

DOEpatents

A ferritic cryogenic steel which has a relatively low (about 4-6%) manganese content and which has been made suitable for use at cryogenic temperatures by a thermal cycling treatment followed by a final tempering. The steel includes 4-6% manganese, 0.02-0.06% carbon, 0.1-0.4% molybdenum and 0-3% nickel.

Morris, Jr., John W. (Berkeley, CA); Niikura, Masakazu (Yokohama, JP)

1981-01-01

76

Manganese, Metallogenium, and Martian Microfossils  

NASA Technical Reports Server (NTRS)

Manganese could easily be considered an abundant element in the Martian regolith, assuming that the composition of martian meteorites reflects the composition of the planet. Mineralogical analyses of 5 SNC meteorites have revealed an average manganese oxide concentration of 0.48%, relative to the 0.1% concentration of manganese found in the Earth's crust. On the Earth, the accumulation of manganese oxides in oceans, soils, rocks, sedimentary ores, fresh water systems, and hydrothermal vents can be largely attributed to microbial activity. Manganese is also a required trace nutrient for most life forms and participates in many critical enzymatic reactions such as photosynthesis. The wide-spread process of bacterial manganese cycling on Earth suggests that manganese is an important element to both geology and biology. Furthermore, there is evidence that bacteria can be fossilized within manganese ores, implying that manganese beds may be good repositories for preserved biomarkers. A particular genus of bacteria, known historically as Metallogenium, can form star-shaped manganese oxide minerals (called metallogenium) through the action of manganese oxide precipitation along its surface. Fossilized structures that resemble metallogenium have been found in Precambrian sedimentary formations and in Cretaceous-Paleogene cherts. The Cretaceous-Paleogene formations are highly enriched in manganese and have concentrations of trace elements (Fe, Zn, Cu, and Co) similar to modern-day manganese oxide deposits in marine environments. The appearance of metallogenium-like fossils associated with manganese deposits suggests that bacteria may be preserved within the minerals that they form. Additional information is contained in the original extended abstract.

Stein, L. Y.; Nealson, K. H.

1999-01-01

77

Insensitivity of tunneling anisotropic magnetoresistance to non-magnetic electrodes  

SciTech Connect

Ferromagnetic electrodes play a crucial role in magnetoresistance effect and spin injection, whereas the essential features of non-magnetic metal electrodes in spintronics are commonly ignored except for their electrical conductivity. Here, we verify that the room-temperature tunneling anisotropic magnetoresistance (TAMR) behavior in antiferromagnet-based [Pt/Co]/IrMn/AlO{sub x}/metal (metal?=?Pt, Au, Cu, Al) junctions is insensitive to the top metal electrodes. Similar out-of-plane signals are detected for different electrodes, in contrast to the varied shapes of in-plane TAMR curves which are most likely attributed to the differences in the multidomain structure of the magnetic electrode. This would add a different dimension to spintronics.

Wang, Y. Y.; Song, C., E-mail: songcheng@mail.tsinghua.edu.cn; Wang, G. Y.; Zeng, F.; Pan, F., E-mail: panf@mail.tsinghua.edu.cn [Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China)

2013-11-11

78

21 CFR 582.5455 - Manganese glycerophosphate.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Manganese glycerophosphate. 582.5455 Section...or Dietary Supplements 1 582.5455 Manganese glycerophosphate. (a) Product. Manganese glycerophosphate. (b) Conditions...

2010-04-01

79

21 CFR 582.5455 - Manganese glycerophosphate.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 2011-04-01 false Manganese glycerophosphate. 582.5455 Section...or Dietary Supplements 1 582.5455 Manganese glycerophosphate. (a) Product. Manganese glycerophosphate. (b) Conditions...

2011-04-01

80

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

81

21 CFR 582.5455 - Manganese glycerophosphate.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 2012-04-01 false Manganese glycerophosphate. 582.5455 Section...or Dietary Supplements 1 582.5455 Manganese glycerophosphate. (a) Product. Manganese glycerophosphate. (b) Conditions...

2012-04-01

82

21 CFR 582.5455 - Manganese glycerophosphate.  

Code of Federal Regulations, 2014 CFR

...2014-04-01 2014-04-01 false Manganese glycerophosphate. 582.5455 Section...or Dietary Supplements 1 582.5455 Manganese glycerophosphate. (a) Product. Manganese glycerophosphate. (b) Conditions...

2014-04-01

83

Giant spin Seebeck effect in a non-magnetic material.  

PubMed

The spin Seebeck effect is observed when a thermal gradient applied to a spin-polarized material leads to a spatially varying transverse spin current in an adjacent non-spin-polarized material, where it gets converted into a measurable voltage. It has been previously observed with a magnitude of microvolts per kelvin in magnetically ordered materials, ferromagnetic metals, semiconductors and insulators. Here we describe a signal in a non-magnetic semiconductor (InSb) that has the hallmarks of being produced by the spin Seebeck effect, but is three orders of magnitude larger (millivolts per kelvin). We refer to the phenomenon that produces it as the giant spin Seebeck effect. Quantizing magnetic fields spin-polarize conduction electrons in semiconductors by means of Zeeman splitting, which spin-orbit coupling amplifies by a factor of ?25 in InSb. We propose that the giant spin Seebeck effect is mediated by phonon-electron drag, which changes the electrons' momentum and directly modifies the spin-splitting energy through spin-orbit interactions. Owing to the simultaneously strong phonon-electron drag and spin-orbit coupling in InSb, the magnitude of the giant spin Seebeck voltage is comparable to the largest known classical thermopower values. PMID:22785317

Jaworski, C M; Myers, R C; Johnston-Halperin, E; Heremans, J P

2012-07-12

84

Manganese exposures during shielded metal arc welding (SMAW) in an enclosed space.  

PubMed

The work reported here evaluates the effectiveness of various rates of dilution ventilation in controlling welder exposures to manganese in shielded metal arc welding (SMAW) fume when working in enclosed or restricted spaces. Personal and area monitoring using total and respirable sampling techniques, along with multiple analytical techniques, was conducted during the welding operations. With 2000 cubic feet per minute (CFM) (56.63 m3/min) dilution ventilation, personal breathing zone concentrations for the welder using 1/8 inches (3.18 mm) E6010 and E7018 mild steel electrodes were within 75% of the existing threshold limit value (TLV of 0.2 mg/m3 for total manganese and were five times greater than the 2001-2003 proposed respirable manganese TLV of 0.03 mg/m3. Manganese concentrations using high manganese content electrodes were five times greater than those for E6010 and E7018 electrodes. Area samples upstream and downstream of the welder using E6010 and E7018 electrodes exceeded 0.2 mg/m3 manganese. Concentrations inside and outside the welding helmet do not indicate diversion of welding fume by the welding helmet from the welder's breathing zone. There was close agreement between respirable manganese and total manganese fume concentrations. Total fume concentrations measured by gravimetric analysis of matched-weight, mixed cellulose ester filters were comparable to those measured via preweighed PVC filter media. This study indicates that 2000 CFM general dilution ventilation per 29 CFR 1910.252 (c)(2) may not be a sufficient means of controlling respirable manganese exposures for either welders or their helpers in restricted or enclosed spaces. In the absence of site-specific monitoring data indicating otherwise, it is prudent to employ respiratory protection or source capture ventilation for SMAW with E6010, E7018, and high manganese content electrodes rather than depending solely on 2000 CFM general dilution ventilation in enclosed spaces. PMID:16080259

Harris, Michael K; Ewing, William M; Longo, William; DePasquale, Christopher; Mount, Michael D; Hatfield, Richard; Stapleton, Randall

2005-08-01

85

Runge-kutta Exponential Time Differencing Method Analysis of Non-magnetized Plasma Stealth  

NASA Astrophysics Data System (ADS)

In this paper, Runge-kutta exponential time differencing (RKETD) method for dispersive media is introduced. The high accuracy and efficiency of this method is verified by calculating the reflection and transmission coefficients for a non-magnetized collisional plasma slab. The stealth effect of radar targets covered with Epstein distribution inhomogeneous non-magnetized plasma is studied. The results show that the stealth effect of radar targets covered with Epstein distribution inhomogeneous plasma is better than that of radar targets covered with homogeneous non-magnetized plasma.

Yang, Hong Wei; Liu, Yan

2010-09-01

86

Using magnetic susceptibility to determin the extent of anthropogenic versus geogenic contamination of heavy metals in soil adjacent to a steel plant  

NASA Astrophysics Data System (ADS)

Nickel and Chromium, depending on their chemical speciation can be is dangerous for human health. They may be deposited anthropogenically or may already be present in the soil geogenically. To distinguish between geogenic or anthropogenic cause of accumulation of these heavy metals, soil taken from the locality Judaskreuzsiedlung, an area adjacent to a steel plant (Donawitz, Leoben, Austria ca. 1 km away from the plant) are studied. Magnetic separation showed that top soil (0-10 cm) in this region contains up to more than 20% magnetic particles mainly of spherical shape (seen under Electron Microprobe Analyzer). These spherical shaped magnetic particles are identified as magnetite (Fe3O4) when analyzed by Multi-Function Kappabriddge for Curie point measurement. The source of these particles can be traced to the steel plant. Moreover calcium, silicon, manganese are found attached to these spherical magnetite. Magnetic susceptibility values of separated (magnetic and non magnetic) fractions and un-separated samples were measured and their chemical analysis was done by XRF and ICP-MS. Correlation between magnetic susceptibility values and concentration of heavy metals demonstrate the idea that magnetite particles are also the carrier of nickel, chromium and other heavy metals. Studies of uncontaminated soils in the region may allow to find criteria to distinguish between anthropogenic or geogenic source of contamination in the area. Applying means of inexpensive magnetic susceptibility field instruments allow to map contaminated areas in a fast and cost effective manner suitable for developing countries.

Meisel, Thomas; Imran Irfan, Muhammad

2010-05-01

87

The manganese toxicity of cotton.  

PubMed

Cotton plants (Gossypium hirsutum. Linn. var. Sankar 4) were grown at normal and toxic levels of substrate manganese, and the altered metabolism of manganese toxic plants was studied. The tissues of plants exposed to toxic levels of manganese had higher activities of peroxidase and polyphenol oxidase, and the activities of catalase, ascorbic acid oxidase, glutathione oxidase and cytochrome c oxidase were lowered. In addition, the high manganese tissue had lower contents of ATP and glutathione but higher amounts of ascorbic acid. The respiration of the partially expanded leaves and the growing tips of toxic plants were depressed when compared to that of the normal tissues. The metabolic changes of manganese toxicity of cotton are placed in the following order: accumulation of manganese in the leaf tissue; a rise in respiration; stimulation of polyphenol oxidase; the appearance of initial toxicity symptoms; the evolution of ethylene and stimulation of peroxidase; the presence of severe toxicity symptoms; the depression of terminal oxidases and respiration; abscission of the growing tip and proliferation of the stem tissue. The early stimulation of polyphenol oxidase may be used to detect potential manganese toxicity. PMID:16658924

Sirkar, S; Amin, J V

1974-10-01

88

Distribution of available manganese in Kentucky soils  

Microsoft Academic Search

Laboratory studies were conducted to determine fractions of native soil and applied manganese 54 that contribute to the manganese extracted by DTPA (0.005 M diethylenetriamine pentaacetic acid, 0.005 M CaCl, 0.1 M triethanolamine, pH 7.3). Since DTPA-extractable manganese is closely related to manganese uptake by plants, such studies should provide information about fractions of soil manganese that contribute most to

J. L. Sims; P. Duangpatra; J. H. Ellis; R. E. Phillips

1979-01-01

89

Thermodynamic and transport properties of non-magnetic particles in magnetic fluids  

E-print Network

Magnetic composites, obtained on associating magnetic fluid with non-magnetic particles, offer interesting opportunities in separations, assemblies and other applications, where the microstructure of the composite can be ...

Tejwani, Saurabh

2009-01-01

90

Manganese waste water treatment by fungi derived from manganese slag.  

PubMed

The aim of this study was to isolate a mould from the surface of manganese slag which had strong resistance and high adsorption of Mn(2 + ), and to determine the effects of initial Mn(2 + ) concentration, incubation temperature, rotation speed and inoculation amount on adsorption of Mn(2 + ) from manganese waste water solution. The result showed that a mould (A5) which was isolated from manganese slag had the adsorption rate of Mn(2 + ) to 97.5% at the initial pH value 6, inoculation amount 2%, rotation speed 150 r/min, a concentration of Mn(2 + ) 500 mg/L, and a temperature of 28 degrees C cultivated for 50 h. As there is no research on adsorption of Mn(2 + ) from manganese waste water by fungi before, this research showed a theoretical guidance on this field. PMID:20818063

Ou-Yang, Yu-Zhu; Cao, Jian-Bing; Li, Xiao-Ming; Zheng, Wei; Wang, Dong-Bo; Zhang, Yi

2010-01-01

91

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

92

Tellurium content of marine manganese oxides and other manganese oxides  

USGS Publications Warehouse

Tellurium in amounts ranging from 5 to 125 parts per million was present in all of 12 samples of manganese oxide nodules from the floor of the Pacific and Indian oceans. These samples represent the first recognized points of high tellurium concentration in a sedimentary cycle. The analyses may lend support to the theory that the minor-element content of seafloor manganese nodules is derived from volcanic emanations.

Lakin, H.W.; Thompson, C.E.; Davidson, D.F.

1963-01-01

93

Influence of C, Mn and Ni Contents on Microstructure and Properties of Strong Steel  

E-print Network

Influence of C, Mn and Ni Contents on Microstructure and Properties of Strong Steel Weld Metals. % were investigated in high strength steel weld metals with 2 wt. % manganese. It was found that nickel. Introduction High strength steel with yield strength greater than 690 MPa (100 ksi) has been welded

Cambridge, University of

94

Use of AES to determine low solubilities of impurities: Case of MnS in austenitic stainless steel  

SciTech Connect

The solubility of manganese sulfide in a commercial 304 austenitic stainless steel was studied using AES to determine surface sulfur segregation. The segregation mechanism at stainless steel surfaces were extensively studied, but thermodynamic data such as segregation free energy, or manganese sulfide dissolution heat have not been established, although these data are of great interest because the MnS dissolution parameters give the amount of free sulfur in solid solution. The only solubility data for manganese sulfide in austenitic steel was given to Turkdogan in 1955 and concerned MnS in iron-manganese alloys. In the present study, the Auger spectra are used to calculate the free energy of dissolution of manganese sulfide as well as the sulfur segregation parameters in austenitic stainless steel.

Hays, V.; Gall, R. le; Saindrenan, G. [ISITEM, Nantes (France). Lab. Genie des Materiaux] [ISITEM, Nantes (France). Lab. Genie des Materiaux; Roptin, D. [ECN, Nantes (France). Lab. Materiaux] [ECN, Nantes (France). Lab. Materiaux

1998-01-06

95

FATE OF METHYLCYCLOPENTADIENYL MANGANESE TRICARBONYL  

EPA Science Inventory

Methylcyclopentadienyl manganese tricarbonyl (MMT) has been proposed as an octane booster for unleaded gasoline; such use could result in ecological and human exposure through surface water and ground water ecosystems. o evaluate the environmental risks from MMT, its environmenta...

96

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

97

Modelling the role of non metallic inclusions on the anisotropic fatigue behaviour of forged steel  

E-print Network

. This study aims at describing the high cycle fatigue response of a forged bainitic steel. This material manganese-sulfide inclusion clusters are the origin of crack initiation and the fatigue strength drops Cycle Fatigue. Keywords: High cycle fatigue; Anisotropy; Manganese Sulphide Inclusions; Probability

Paris-Sud XI, Universit de

98

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

2011-01-01

99

21 CFR 184.1449 - Manganese citrate.  

Code of Federal Regulations, 2010 CFR

...It is obtained by precipitating manganese carbonate from manganese sulfate and sodium carbonate solutions. The filtered and washed precipitate...solution to form manganous citrate and then with sodium citrate to complete the reaction....

2010-04-01

100

21 CFR 184.1449 - Manganese citrate.  

Code of Federal Regulations, 2014 CFR

...It is obtained by precipitating manganese carbonate from manganese sulfate and sodium carbonate solutions. The filtered and washed precipitate...solution to form manganous citrate and then with sodium citrate to complete the reaction....

2014-04-01

101

21 CFR 184.1449 - Manganese citrate.  

Code of Federal Regulations, 2012 CFR

...It is obtained by precipitating manganese carbonate from manganese sulfate and sodium carbonate solutions. The filtered and washed precipitate...solution to form manganous citrate and then with sodium citrate to complete the reaction....

2012-04-01

102

21 CFR 184.1449 - Manganese citrate.  

Code of Federal Regulations, 2013 CFR

...It is obtained by precipitating manganese carbonate from manganese sulfate and sodium carbonate solutions. The filtered and washed precipitate...solution to form manganous citrate and then with sodium citrate to complete the reaction....

2013-04-01

103

21 CFR 184.1449 - Manganese citrate.  

Code of Federal Regulations, 2011 CFR

...It is obtained by precipitating manganese carbonate from manganese sulfate and sodium carbonate solutions. The filtered and washed precipitate...solution to form manganous citrate and then with sodium citrate to complete the reaction....

2011-04-01

104

21 CFR 73.2775 - Manganese violet.  

Code of Federal Regulations, 2012 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...

2012-04-01

105

21 CFR 73.2775 - Manganese violet.  

Code of Federal Regulations, 2011 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...

2011-04-01

106

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

107

Heteroepitaxial Nucleation and Oriented Growth of Manganese  

E-print Network

Heteroepitaxial Nucleation and Oriented Growth of Manganese Oxide Islands on Carbonate Minerals and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138 Manganese redox cycling study, Mn2+(aq) is reacted with O2(aq) at circumneutral pH to form manganese oxide islands on the (101h4

108

Original article Studies on differential manganese tolerance  

E-print Network

Original article Studies on differential manganese tolerance of mung bean and rice genotypes germinated and grown in the presence of manganese under controlled environmental conditions. Standard growth tested as markers of manganese toxicity. Measurements as early as 48 hours after the germination did

Boyer, Edmond

109

Original article Intestinal transfer of manganese  

E-print Network

Original article Intestinal transfer of manganese: resemblance to and competition with calcium Y of calcium, phosphate and the sugars lactose and sorbitol on the intestinal absorption of manganese were / Ca lglucides / phosphates #12;INTRODUCTION The intestinal transport of manganese seems very similar

Paris-Sud XI, Université de

110

Manganese depresses rat heart muscle respiration  

Technology Transfer Automated Retrieval System (TEKTRAN)

It has previously been reported that moderately high dietary manganese (Mn) in combination with marginal magnesium (Mg) resulted in ultrastructural damage to heart mitochondria. Manganese may replace Mg in biological functions, including the role of enzyme cofactor. Manganese may accumulate and subs...

111

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

112

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

E-print Network

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 that the resulting structure has relatively low loss. We develop the analytical description of the relevant electromagnetic phenomena and justify our analytic results via numerical solutions of Maxwell equations.

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

2005-06-27

113

Biomarkers of Manganese Intoxication  

PubMed Central

Manganese (Mn), upon absorption, is primarily sequestered in tissue and intracellular compartments. For this reason, blood Mn concentration does not always accurately reflect Mn concentration in the targeted tissue, particularly in the brain. The discrepancy between Mn concentrations in tissue or intracellular components means that blood Mn is a poor biomarker of Mn exposure or toxicity under many conditions and that other biomarkers must be established. For group comparisons of active workers, blood Mn has some utility for distinguishing exposed from unexposed subjects, although the large variability in mean values renders it insensitive for discriminating one individual from the rest of the study population. Mn exposure is known to alter iron (Fe) homeostasis. The Mn/Fe ratio (MIR) in plasma or erythrocytes reflects not only steady-state concentrations of Mn or Fe in tested individuals, but also a biological response (altered Fe homeostasis) to Mn exposure. Recent human studies support the potential value for using MIR to distinguish individuals with Mn exposure. Additionally, magnetic resonance imaging (MRI), in combination with noninvasive assessment of ?-aminobutyric acid (GABA) by magnetic resonance spectroscopy (MRS), provides convincing evidence of Mn exposure, even without clinical symptoms of Mn intoxication. For subjects with long-term, low-dose Mn exposure or for those exposed in the past but not the present, neither blood Mn nor MRI provides a confident distinction for Mn exposure or intoxication. While plasma or erythrocyte MIR is more likely a sensitive measure, the cut-off values for MIR among the general population need to be further tested and established. Considering the large accumulation of Mn in bone, developing an X-ray fluorescence spectroscopy or neutron-based spectroscopy method may create yet another novel non-invasive tool for assessing Mn exposure and toxicity. PMID:20946915

Zheng, Wei; Fu, Sherleen X.; Dydak, Ulrike; Cowan, Dallas M.

2010-01-01

114

ADVANCEMENTS IN STEEL FOR WEIGHT REDUCTION OF P900 ARMOR PLATE  

Microsoft Academic Search

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 perforated armor currently used for Army ground combat systems. Two steel plates with nominal composition in weight percent of Fe-30Mn-9Al-1Si-0.9C-0.5Mo were

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

115

Magnetic property variations in nickel caused by non-magnetic inclusions  

Microsoft Academic Search

A study of the effect of non-magnetic particles on the magnetic properties of nickel is reported. The presence of inclusions is known to affect the structure sensitive magnetic properties of materials. In this work, two kinds of inclusions, namely, alumina particles and voids were studied and their effects on the magnetic properties were investigated. Powder metallurgy techniques were used to

A. Ramesh; M. R. Govindaraju; D. C. Jiles; S. B. Biner

1996-01-01

116

Manganese and chronic hepatic encephalopathy  

Microsoft Academic Search

SummaryClinical observations and animal studies have raised the hypothesis that increased concentrations of manganese (Mn) in whole blood might lead to accumulation of this metal within the basal ganglia in patients with end-stage liver disease. We studied ten patients with liver failure (and ten controls) by magnetic resonance imaging (MRI) and measurement of Mn in brain tissue of three patients

D Krieger; S Krieger; L Theilmann; O Jansen; P Gass; H Lichtnecker

1995-01-01

117

Action of manganese on puberty  

E-print Network

to Mn than adults, we wanted to determine the effects of Mn exposure on puberty-related hormones and the onset of puberty, and discern the site and mechanism of Mn action. We demonstrated that the central administration of manganese chloride (MnCl2...

Lee, Bo Yeon

2007-09-17

118

Manganese Pollution and Violent Crime  

Microsoft Academic Search

Evidence of my scientific career and qualification to assess harmful effects of pollution with manganese (or other toxins like lead or hydrofluorosilicic acid) is available in Who's Who in America. In addition to peer reviewed publications on the harmful effects of toxins. I have given papers at the International Society of Neurotoxicology, the American Academy of Environmental Medicine, & other

Roger D. Masters

119

Precipitates in electrical steels  

NASA Astrophysics Data System (ADS)

Precipitates heavily influence the magnetic properties of electrical steels, either as a key controlled requirement as part of the manufacturing process or as an unwanted harmful residual in the final product. In this current work copper-manganese sulphides precipitates are the primary inhibitor species in the conventional grain-oriented (CGO) steels examined and grain boundary pinning is effective at a mean precipitate size of 30-70 nm. The growth of CuMnS has been studied and the results show that a precipitate size above 100 nm allows the onset of secondary recrystallisation in the heating conditions applied. The effect of precipitates on the magnetic properties of both grain-oriented and non-oriented steels in their final product form is then examined. Examples of grain-oriented material still containing large numbers of precipitates clearly show the detrimental effects with increases in total power loss of 40% or more. Loss deterioration by about 20% is also seen in samples of high silicon non-oriented material in which titanium carbo-nitride precipitates have been observed. In this case the precipitates are believed to have formed during cooling after final annealing. Finally a grain-oriented steel with a large number of very small precipitates, which do not seem to have any harmful effect on the magnetic properties, is demonstrated.

Jenkins, Keith; Lindenmo, Magnus

120

Synthesis, characterization, optical and sensing property of manganese oxide nanoparticles  

SciTech Connect

Manganese oxide nanoparticles were prepared by thermal decomposition of manganese oxalate. Manganese oxalate was synthesized by reacting 1:1 mole ratio of manganese acetate and ammonium oxalate along with sodium dodecyl sulfate (SDS). The structural characterization of manganese oxalate and manganese oxide nanoparticles was analyzed by XRD. The XRD spectrum confirms the crystal structure of the manganese oxide and manganese oxalate. In addition, the average grain size, lattice parameter values were also calculated using XRD spectrum. Moreover, the diffraction peaks were broadened due to the smaller size of the particle. The band gap of manganese oxide was calculated from optical absorption, which was carried out by DRS UV-Visible spectroscopy. The morphology of manganese oxide nanoparticles was analyzed by SEM images. The FT-IR analysis confirms the formation of the manganese oxide from manganese oxalate nanoparticles. The electrochemical sensing behavior of manganese oxide nanoparticles were investigated using hydrogen peroxide by cyclic voltammetry.

Manigandan, R.; Suresh, R.; Giribabu, K.; Narayanan, V., E-mail: vnnara@yahoo.co.in [Department of Inorganic Chemistry, University of Madras, Guindy Campus, Chennai 600 025 (India); Vijayalakshmi, L. [Annai Veilankanni's College for Women (Arts and Science), Saidapet, Chennai 600015 (India); Stephen, A. [Department of Nuclear Physics, University of Madras, Guindy Campus, Chennai 600 025 (India)

2014-01-28

121

Synthesis, characterization, optical and sensing property of manganese oxide nanoparticles  

NASA Astrophysics Data System (ADS)

Manganese oxide nanoparticles were prepared by thermal decomposition of manganese oxalate. Manganese oxalate was synthesized by reacting 1:1 mole ratio of manganese acetate and ammonium oxalate along with sodium dodecyl sulfate (SDS). The structural characterization of manganese oxalate and manganese oxide nanoparticles was analyzed by XRD. The XRD spectrum confirms the crystal structure of the manganese oxide and manganese oxalate. In addition, the average grain size, lattice parameter values were also calculated using XRD spectrum. Moreover, the diffraction peaks were broadened due to the smaller size of the particle. The band gap of manganese oxide was calculated from optical absorption, which was carried out by DRS UV-Visible spectroscopy. The morphology of manganese oxide nanoparticles was analyzed by SEM images. The FT-IR analysis confirms the formation of the manganese oxide from manganese oxalate nanoparticles. The electrochemical sensing behavior of manganese oxide nanoparticles were investigated using hydrogen peroxide by cyclic voltammetry.

Manigandan, R.; Suresh, R.; Giribabu, K.; Vijayalakshmi, L.; Stephen, A.; Narayanan, V.

2014-01-01

122

Chemical and microbiological studies of sulfide?mediated manganese reduction  

Microsoft Academic Search

Laboratory studies of manganese reduction by naturally occurring reduced inorganic compounds were undertaken, both to study further possible in situ mechanisms of manganese reduction and to examine how manganese redox reactions might be coupled to other biogeochemical processes. Chemical manganese reduction by sulfide (in the presence of excess manganese oxide) was found to be rapid and complete, with all sulfide

David J. Burdige; Kenneth H. Nealson

1986-01-01

123

Filling Narrow Trenches by Iodine-Catalyzed CVD of Copper and Manganese on Manganese Nitride Barrier/Adhesion Layers  

E-print Network

Filling Narrow Trenches by Iodine-Catalyzed CVD of Copper and Manganese on Manganese Nitride). Conformally deposited manganese nitride serves as an underlayer that initially chemisorbs iodine. CVD of copper or copper-manganese alloy releases the adsorbed iodine atoms from the surface of the manganese

124

Impact of dietary manganese concentration on status criteria to determine manganese requirement in piglets.  

PubMed

The Mn requirement for pigs is not well established. This study aimed to find criteria for assessing growing piglet supply status for Mn and to determine whether the current Mn recommendations meet the requirements for piglets. Thirty-six weaned male castrated 27-day-old piglets (7.24??0.69?kg) were randomized into six groups of six piglets each and housed individually in stainless steel metabolic cages for 42?days. The piglets were fed a diet based on skimmed milk powder and corn starch with increasing Mn concentrations (0.24; 2; 4; 8; 16; or 32?mg?Mn/kg diet as-fed). In week 6, Mn0.24 led to reduced feed intake (p?Manganese concentrations in blood, liver, kidney, lung, heart, phalanx proximalis, pancreas and skeletal muscle were influenced by the dietary Mn supply (p?Manganese concentrations in the liver, kidney and phalanx proximalis seem to be suitable biomarkers for Mn status. A 4?mg/kg dietary Mn concentration recommended by NRC (1998, Nutrient Requirements of Swine. National Academy Press, Washington DC.) did not fulfil piglet requirements. Under the conditions investigated, 16?mg?Mn/kg diet were necessary to reach a plateau in specific enzyme activity and Mn concentration in organs. PMID:21883497

Pallauf, J; Kauer, C; Most, E; Habicht, S D; Moch, J

2012-12-01

125

Spectroscopic characterization of manganese minerals.  

PubMed

Manganese minerals ardenite, alleghanyite and leucopoenicite originated from Madhya Pradesh, India, Nagano prefecture Japan, Sussex Country and Parker Shaft Franklin, Sussex Country, New Jersey respectively are used in the present work. In these minerals manganese is the major constituent and iron if present is in traces only. An EPR study of on all of the above samples confirms the presence of Mn(II) with g around 2.0. Optical absorption spectrum of the mineral alleghanyite indicates that Mn(II) is present in two different octahedral sites and in leucophoenicite Mn(II) is also in octahedral geometry. Ardenite mineral gives only a few Mn(II) bands. NIR results of the minerals ardenite, leucophoenicite and alleghanyite are due to hydroxyl and silicate anions which confirming the formulae of the minerals. PMID:23995604

Lakshmi Reddy, S; Padma Suvarna, K; Udayabhaska Reddy, G; Endo, Tamio; Frost, R L

2014-01-01

126

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

Code of Federal Regulations, 2012 CFR

...2012-07-01 2012-07-01 false Manganese heterocyclic tetraamine complex (generic...Chemical Substances 721.10003 Manganese heterocyclic tetraamine complex (generic...chemical substances identified generically as manganese heterocyclic tetraamine...

2012-07-01

127

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

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false Manganese heterocyclic tetraamine complex (generic...Chemical Substances 721.10003 Manganese heterocyclic tetraamine complex (generic...chemical substances identified generically as manganese heterocyclic tetraamine...

2011-07-01

128

40 CFR 721.10011 - Barium calcium manganese strontium oxide.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 false Barium calcium manganese strontium oxide. 721.10011 Section...Substances 721.10011 Barium calcium manganese strontium oxide. (a) Chemical substance...substance identified as barium calcium manganese strontium oxide (PMN...

2012-07-01

129

40 CFR 721.10011 - Barium calcium manganese strontium oxide.  

Code of Federal Regulations, 2013 CFR

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

2013-07-01

130

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

131

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

Code of Federal Regulations, 2014 CFR

...2014-07-01 2014-07-01 false Manganese heterocyclic tetraamine complex (generic...Chemical Substances 721.10003 Manganese heterocyclic tetraamine complex (generic...chemical substances identified generically as manganese heterocyclic tetraamine...

2014-07-01

132

40 CFR 721.10011 - Barium calcium manganese strontium oxide.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 false Barium calcium manganese strontium oxide. 721.10011 Section...Substances 721.10011 Barium calcium manganese strontium oxide. (a) Chemical substance...substance identified as barium calcium manganese strontium oxide (PMN...

2011-07-01

133

40 CFR 721.10011 - Barium calcium manganese strontium oxide.  

Code of Federal Regulations, 2014 CFR

...2014-07-01 false Barium calcium manganese strontium oxide. 721.10011 Section...Substances 721.10011 Barium calcium manganese strontium oxide. (a) Chemical substance...substance identified as barium calcium manganese strontium oxide (PMN...

2014-07-01

134

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

135

40 CFR 721.10201 - Cobalt lithium manganese nickel oxide.  

Code of Federal Regulations, 2012 CFR

...false Cobalt lithium manganese nickel oxide. 721.10201 Section...10201 Cobalt lithium manganese nickel oxide. (a) Chemical substance...as cobalt lithium manganese nickel oxide (PMN P-04-269...Requirements as specified in 721.63 (a)(1),...

2012-07-01

136

40 CFR 721.10201 - Cobalt lithium manganese nickel oxide.  

Code of Federal Regulations, 2014 CFR

...false Cobalt lithium manganese nickel oxide. 721.10201 Section...10201 Cobalt lithium manganese nickel oxide. (a) Chemical substance...as cobalt lithium manganese nickel oxide (PMN P-04-269...Requirements as specified in 721.63 (a)(1),...

2014-07-01

137

40 CFR 721.10201 - Cobalt lithium manganese nickel oxide.  

Code of Federal Regulations, 2013 CFR

...false Cobalt lithium manganese nickel oxide. 721.10201 Section...10201 Cobalt lithium manganese nickel oxide. (a) Chemical substance...as cobalt lithium manganese nickel oxide (PMN P-04-269...Requirements as specified in 721.63 (a)(1),...

2013-07-01

138

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. 721.10011...Chemical Substances 721.10011 Barium calcium manganese strontium oxide. (a...chemical substance identified as barium calcium manganese strontium oxide (PMN...

2010-07-01

139

Iron and manganese in lakes  

Microsoft Academic Search

The role of redox processes in determining the chemistry of iron and manganese is considered systematically. Both metals have soluble reduced forms and insoluble oxyhydroxides which are readily interconverted in the vicinity of a redox boundary. Although the oxyhydroxides are dominant in well-oxygenated waters, measureable concentrations of Fe(II) and Mn(II) can be observed, especially where photochemical reduction occurs. Differences in

William Davison

1993-01-01

140

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

141

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

142

Magnetic Adaptive Testing of Non-magnetic Properties of Ferromagnetic Materials  

Microsoft Academic Search

A method of Magnetic Adaptive Testing (MAT) has been developed lately for optimized non-destructive detection and analysis of variation\\/degradation of non-magnetic features of ferromagnetic materials. Based on simple measurement of representative pools of magnetic hysteresis data, and on the fact that the inspected material degradation modifies the corresponding data-pools, remarkable magnetic descriptors - optimally adapted to the investigated system -

I. Tom

2004-01-01

143

Thickness measurement of non-magnetic plates using multi-frequency eddy current sensors  

Microsoft Academic Search

A robust feature in multi-frequency eddy current (MEC) testing has been found that can be directly linked to the thickness of the plate under test. It is shown mathematically that the peak frequency of the imaginary part of the inductance change when an air-cored coil is placed next to a non-magnetic metallic plate is inversely proportional to the thickness of

W. Yin; A. J. Peyton

2007-01-01

144

Negative impact of manganese on honeybee foraging.  

PubMed

Anthropogenic accumulation of metals such as manganese is a well-established health risk factor for vertebrates. By contrast, the long-term impact of these contaminants on invertebrates is mostly unknown. Here, we demonstrate that manganese ingestion alters brain biogenic amine levels in honeybees and fruit flies. Furthermore, we show that manganese exposure negatively affects foraging behaviour in the honeybee, an economically important pollinator. Our findings indicate that in addition to its direct impact on human health, the common industrial contaminant manganese might also have indirect environmental and economical impacts via the modulation of neuronal and behavioural functions in economically important insects. PMID:25808001

Svik, Eirik; Perry, Clint J; LaMora, Angie; Barron, Andrew B; Ben-Shahar, Yehuda

2015-03-01

145

Electronic band structures and magnetism of intermetallic Cu 2Sb-type manganese compounds MnAlGe and MnGaGe  

NASA Astrophysics Data System (ADS)

Electronic band structures of intermetallic manganese compounds, MnAlGe and MnGaGe, having the Cu 2Sb-type crystal structure are calculated for both the non-magnetic and ferromagnetic states by a self-consistent augmented-plane-wave (APW) method. The gross features of the dispersion curve and the density of states of MnAlGe are similar to those of MnGaGe, Mn-3d states are hybridized with Al-3p or Ga-4p states and Ge-4p states. A strong two-dimensional character has been found in the Fermi surfaces obtained for the non-magnetic and ferromagnetic bands. The calculated magnetic moments in the ferromagnetic state are in good agreement with the observed results.

Motizuki, K.; Korenari, T.; Shirai, M.

1992-02-01

146

Manganese nodules: thorium-230: protactinium-231 ratios.  

PubMed

The Th(230): Pa(231) activity ratio in 7 of 11 manganese nodules is less than 10.8, the theoretical production ratio of activities in the ocean. This finding indicates difierential accumulation of these nuclides in authigenic deposits of manganese-iron oxide. PMID:17778807

Sackett, W M

1966-11-01

147

Drinking Water Problems: Iron and Manganese  

E-print Network

Iron and manganese can give water an unpleasant taste, odor and color. In this publication you'll learn how to know whether your water contains iron or manganese and how to eliminate these contaminants with various treatment methods such as aeration...

Dozier, Monty; McFarland, Mark L.

2004-02-20

148

Manganese and Oxidative Damage in Cucumber  

Microsoft Academic Search

Micronutrients in low or high concentration can affect growth, respiration, photosynthesis, and reproduction in plants. Cucumber (Cucumis sativus, L.) is grown in India in areas low or high in manganese concentration in soils. A study was conducted to investigate the effects of manganese concentration on some metabolic activities affecting developmental responses in cucumber. Seed of cucumber, cv. Sonali, were grown

Rajeev Gopal

2008-01-01

149

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

150

New Experimental Evidence on the Incomplete Transformation Phenomenon in Steel.  

SciTech Connect

The aim of this work is to analyse the carbon content distribution in austenite during isothermal bainite formation and the incomplete reaction phenomenon by means of X-ray diffraction analysis and atom-probe tomography in high silicon, manganese alloyed steels. Results provide new evidence on the explanation for the incomplete reaction phenomenon and the bainite transformation theory.

Caballero, Francesca G. [CENIM-CSIC, Madrid, Spain; Garcia-Mateo, C. [CENIM-CSIC, Madrid, Spain; Santofimia, M. J. [Delft University of Technology, Delft, Netherlands; Miller, Michael K [ORNL; Garcia de Andres, C [CENIM-CSIC, Madrid, Spain

2009-01-01

151

Comparisons among magnetic and non-magnetic fly ash fractions: Strength development of cement-fly ash mortars  

Microsoft Academic Search

Magnetic extractions from aqueous-fly ash suspensions produced magnetic and non-magnetic fly ash fractions. Several fractions were obtained from an original fly ash (T0), from T0 and further grinding, and from a ground fly ash (T60). Magnetic and non-magnetic samples were characterized: chemical composition, granulometric data, specific gravity and specific surface area. Workability studies on mortars containing these fractions were carried

J. Pay; J. Monz; M. V. Borrachero; E. Peris-Mora

1996-01-01

152

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

153

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

154

Dinuclear manganese centers in the manganese-lead-tellurate glasses.  

PubMed

FTIR, UV-VIS and EPR spectra of manganese doped lead-tellurate glasses with composition xMnO(100-x)[4TeO2PbO2] where x=0, 1, 5, 10, 20, 30, 40mol% have been studied. The FTIR spectra show the formation of the Mn-O-Pb and Mn-O-Te bridging bonds by increasing of MnO concentration. The UV-VIS spectra show the Mn(+3) species exhibit pronounced absorption, which masks the Mn(+2) spin-forbidden absorption bands when Mn(+2) ions are in high concentrations in these glasses. The EPR spectra exhibit resonance signals characteristic of Mn(+2) ions. The resonance signal located at g?2 is due to Mn(+2) ions in an environment close to octahedral symmetry, whereas the resonance at g?4.3 and 3.3 are attributed to the rhombic surroundings of the Mn(+2) ions. The increase in the MnO content gives rise to absorption at g?2.4 and the paramagnetic ions are involved in dinuclear manganese centers. PMID:21498108

Rada, S; Dehelean, A; Culea, M; Culea, E

2011-07-01

155

Manganese borohydride; synthesis and characterization.  

PubMed

Solvent-based synthesis and characterization of ?-Mn(BH4)2 and a new nanoporous polymorph of manganese borohydride, ?-Mn(BH4)2, via a new solvate precursor, Mn(BH4)21/2S(CH3)2, is presented. Manganese chloride is reacted with lithium borohydride in a toluene/dimethylsulfide mixture at room temperature, which yields halide and solvent-free manganese borohydride after extraction with dimethylsulfide (DMS) and subsequent removal of residual solvent. This work constitutes the first example of establishing a successful, reproducible solvent-based synthesis route for a pure, crystalline, stable transition metal borohydride. The new polymorph, ?-Mn(BH4)2, is shown to be the manganese counterpart of the zeolite-like compound, ?-Mg(BH4)2 (cubic, a = 16.209(1) , space group Id3[combining macron]a). It is verified that large pores (diameter > 6.0 ) exist in this structure. The solvate, Mn(BH4)21/2S(CH3)2, is subsequently shown to be the analogue of Mg(BH4)21/2S(CH3)2. As the structural analogies between Mg(BH4)2 and Mn(BH4)2 became evident a new polymorph of Mg(BH4)2 was identified and termed ?-Mg(BH4)2. ?-Mg(BH4)2 is the structural counterpart of ?-Mn(BH4)2. All synthesis products are characterized employing synchrotron radiation-powder X-ray diffraction, infrared spectroscopy and thermogravimetric analysis in combination with mass spectroscopy. Thermal analysis reveals the decomposition of Mn(BH4)2 to occur at 160 C, accompanied by a mass loss of 14.8 wt%. A small quantity of the desorbed gaseous species is identified as diborane (?m(Mn(BH4)2) = 9.5 wt% H2), while the remaining majority is found to be hydrogen. PMID:25611294

Richter, Bo; Ravnsbk, Dorthe B; Tumanov, Nikolay; Filinchuk, Yaroslav; Jensen, Torben R

2015-02-17

156

Phase transformational kinetics and hardenability of alloyed medium-carbon steels  

Microsoft Academic Search

The phase transformational kinetics and hardenability of 0.4 pct C steels were studied as influenced by alloying elements,\\u000a singly and in combination. Sixteen series of steels, each containing up to about 0.75 pct Mo, were prepared by laboratory\\u000a induction air melting. The base steels contained manganese, chromium, nickel, silicon, and combinations of these elements\\u000a as alloy additions. Continuous cooling transformation

W. W. Cias; D. V. Doane

1973-01-01

157

MANGANESE--2002 49.1 By Lisa A. Corathers  

E-print Network

MANGANESE--2002 49.1 MANGANESE By Lisa A. Corathers Domestic survey data and tables were prepared Logistics Agency issued on October 1, 2002, was the same with respect to manganese as in the revised fiscal year 2002 AMP issued on October 1, 2001, with the exception of the manganese ferrogroup. The AMP

Torgersen, Christian

158

MANGANESE--2003 48.1 By Lisa A. Corathers  

E-print Network

MANGANESE--2003 48.1 MANGANESE By Lisa A. Corathers Domestic survey data and tables were prepared on December 23, 2002, was the same with respect to manganese as in the revised fiscal year 2002 AMP issued September 30, 2003. Under this AMP, the maximum disposal authority for manganese materials was 226

Torgersen, Christian

159

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

160

Spintronic transport of a non-magnetic molecule between magnetic electrodes  

SciTech Connect

The spintronic transport properties of a junction system composed of a non-magnetic molecule sandwiched between ferromagnetic metal electrodes are investigated theoretically using a non-equilibrium Green's function method based on density functional theory. It is revealed that in such a system, the molecular magnetic properties induced by hybridization with the magnetic electrodes play a crucial role. Alignment of the induced molecular spin-split levels is strongly related to the spin injection and tunneling magneto-resistance effects. It is found that in the system with weaker molecule-electrode interaction, stronger spintronic effects of the spin injection and tunneling magneto-resistance are observed.

Kondo, Hisashi, E-mail: kondo@tokyo.rist.or.jp [Institute of Industrial Science, University of Tokyo, Meguro, Tokyo 153-8505 (Japan)] [Institute of Industrial Science, University of Tokyo, Meguro, Tokyo 153-8505 (Japan); Ohno, Takahisa, E-mail: OHNO.Takahisa@nims.go.jp [Computational Materials Science Unit, National Institute for Materials Science, Tsukuba, Ibaraki 305-0047 (Japan) [Computational Materials Science Unit, National Institute for Materials Science, Tsukuba, Ibaraki 305-0047 (Japan); Institute of Industrial Science, University of Tokyo, Meguro, Tokyo 153-8505 (Japan)

2013-12-02

161

Manganese oxidation by Leptothrix discophora.  

PubMed Central

Cells of Leptothrix discophora SS1 released Mn2+-oxidizing factors into the medium during growth in batch culture. Manganese was optimally oxidized when the medium was buffered with HEPES (N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid) at pH 7.5. Manganese-oxidizing activity in the culture medium in which this strain had been grown previously was sensitive to heat, phosphate, Tris, NaN3, HgCl2 NaCl, sodium dodecyl sulfate, and pronase; 0.5 mol of O2 was consumed per mol of MnO2 formed. During Mn2+ oxidation, protons were liberated. With sodium dodecyl sulfate-polyacrylamide gel electrophoresis, two protein-containing bands were detected in the spent culture medium. One band had an apparent molecular weight of 110,000 and was predominant in Mn2+-oxidizing activity. The second product (Mr 85,000) was only detected in some cases and probably represents a proteolytic breakdown moiety of the 110,000-Mr protein. The Mn2+-oxidizing factors were associated with the MnO2 aggregates that had been formed in spent culture medium. After solubilization of this MnO2 with ascorbate, Mn2+-oxidizing activity could be recovered. Images PMID:3804969

Boogerd, F C; de Vrind, J P

1987-01-01

162

OXIDATION AND SORPTION KINETICS OF ARSENIC ON A POORLY CRYSTALLINE MANGANESE OXIDE  

E-print Network

OXIDATION AND SORPTION KINETICS OF ARSENIC ON A POORLY CRYSTALLINE MANGANESE OXIDE by Brandon J MANGANESE OXIDE by Brandon J. Lafferty Approved..........................................................................................................1 Manganese Oxides...................................

Sparks, Donald L.

163

Manganese peroxidase gene transcription in Phanerochaete chrysosporium: activation by manganese.  

PubMed Central

The expression of manganese peroxidase in nitrogen-limited cultures of Phanerochaete chrysosporium is dependent on Mn, and initial work suggested that Mn regulates transcription of the mnp gene. In this study, using Northern (RNA) blot analysis of kinetic, dose-response, and inhibitor experiments, we demonstrate unequivocally that Mn regulates mnp gene transcription. The amount of mnp mRNA in cells of 4-day-old nitrogen-limited cultures is a direct function of the concentration of Mn in the culture medium up to a maximum of 180 microM. Addition of Mn to nitrogen-limited Mn-deficient secondary metabolic (4-, 5-, and 6-day-old) cultures results in the appearance of mnp mRNA within 40 min. The appearance of this message is completely inhibited by the RNA synthesis inhibitor dactinomycin but not by the protein synthesis inhibitor cycloheximide. Furthermore, the amount of mnp mRNA produced is a direct function of the concentration of added Mn. In contrast, addition of Mn to low-nitrogen Mn-deficient 2- or 3-day-old cultures does not result in the appearance of mnp mRNA. Manganese peroxidase protein is detected by specific immunoprecipitation of the in vitro translation products of poly(A) RNA isolated from Mn-supplemented (but not from Mn-deficient) cells. All of these results demonstrate that Mn, the substrate for the enzyme, regulates mnp gene transcription via a growth-stage-specific and concentration-dependent mechanism. Images PMID:2061289

Brown, J A; Alic, M; Gold, M H

1991-01-01

164

49 CFR 178.61 - Specification 4BW welded steel cylinders with electric-arc welded longitudinal seam.  

Code of Federal Regulations, 2010 CFR

...hearth, electric or basic oxygen carbon steel of uniform quality. Content...may not exceed the following: Carbon 0.25, Manganese 0.60...maximum ratio of 2.1. If low carbon steel is used, the thickness...must be butt with one member offset (joggle butt) or lap...

2010-10-01

165

Manipulation of magnetic state in phosphorene layer by non-magnetic impurity doping  

NASA Astrophysics Data System (ADS)

Using the full-potential linearized augmented plane wave method, we have explored the structural, electronic band structure, binding energy, and magnetic properties of a non-magnetic impurity (Al, Si, S, and Cl) doped phosphorene layer. The binding energy showed a tendency to decrease with increasing atomic number. Nonetheless, we still found large binding energies of 5.1 eV ? 8.3 eV. We observed that the electronic band structure and magnetic property were strongly dependent on the specific impurity atom. For instance, we propose that the Al doped system will show a semiconducting transport property. In all other systems, we found metallic band structures. We predict that the Al and Si impurity act as donor elements whereas the S and Cl impurities behave as acceptor elements. Interestingly, the magnetic state appeared in Si, S, and Cl doped systems while the Al impurity induced no spin polarized state. In the Si doped system, the major contribution to a magnetic moment originated from Si impurity itself, while the presence of dangling bonds at a neighboring P atom near the impurity site plays a crucial role for magnetism in S and Cl doped systems. On the other hand, interestingly, we observed a half metallic feature in the S doped layer. Overall, we have found that the magnetic state can be manipulated by even non-magnetic impurity doping in a phosphorene layer.

Khan, Imran; Hong, Jisang

2015-02-01

166

Manganese biosorption sites of Saccharomyces cerevisiae.  

PubMed

Experiments conducted by pre-treating the fermentation industrial waste biomass of Saccharomyces cerevisiae with laboratory grade chemicals like formaldehyde-formic acid, ethanol, triethyl phosphite-nitromethane, dithiopyridine and benzene helped in studying the roles played by amines, carboxylic acids, phosphates, sulfhydryl group and lipids present on the cell wall of the biomass in manganese biosorption. Potentiometric titration of S. cerevisiae revealed the presence of carboxyl, phosphate, amine groups. The extent of the contribution of the functional groups and lipids to manganese biosorption was in the order: carboxylic acids > amines > lipids > phosphates. Blocking of sulfhydryl group did not have any significant effect on manganese uptake. PMID:17674651

Parvathi, K; Nareshkumar, R; Nagendran, R

2007-07-01

167

Iron and Manganese in Potable Water  

E-print Network

be treated in a number of ways. It can be heated and con verted to M n 3 O4, or dissolved in hydrochloric acid and precipitated as Mn NH 4 P 0 4 . This last has been worked (Ril over by Gibbs 'and by Gooch and Austin , all of whom pronounce it very... of Manganese 2. The precipitation of Manganese by means of (RS) ammonium carbonate we can dismiss at once as not being 4. available for water, for calcium and magnesium would be precipitated at the same time. 3. The precipitation of Manganese as MnOa hy...

Young, Clifford Caudy

1911-06-01

168

Chronic manganese poisoning: A neuropathological study with determination of manganese distribution in the brain  

Microsoft Academic Search

An autopsy case of a 52-year-old man suffering from chronic manganese poisoning (CMP) is reported with determination of the manganese distribution in the brain. The patient had been working in a manganese ore crushing plant since 1965. In 1967 he began to complain of difficulties in walking and diminished libido. Later, he developed various neuro-psychiatric symptoms including euphoria, emotional incontinence,

M. Yamada; S. Ohno; I. Okayasu; R. Okeda; S. Hatakeyama; H. Watanabe; K. Ushio; H. Tsukagoshi

1986-01-01

169

Optimisation of metallic pigments in coatings by an electrochemical technique and an investigation of manganese powder as pigment for metal rich primers  

Microsoft Academic Search

Zinc dust and manganese powder as pigments were incorporated in epoxy-polyamide and butyl titanate medium, with different pigment volume concentration (PVC) ranging from 20 to 74. These protective coatings were coated on sand blasted mild steel substrates and immersed in 3 wt.% sodium chloride solution and the corrosion current was measured by the Tafel extrapolation method. From the corrosion current

M. Selvaraj; S. Guruviah

1996-01-01

170

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

171

21 CFR 73.2775 - Manganese violet.  

Code of Federal Regulations, 2014 CFR

...Identity. The color additive manganese violet...be avoided by good manufacturing practice: Ash...filtrate of 10 grams color additive (shaken occasionally...consistent with good manufacturing practice. (d) Labeling. The color additive and any mixture...

2014-04-01

172

21 CFR 184.1446 - Manganese chloride.  

Code of Federal Regulations, 2010 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...

2010-04-01

173

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

174

21 CFR 184.1446 - Manganese chloride.  

Code of Federal Regulations, 2011 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...

2011-04-01

175

HEALTH ASSESSMENT DOCUMENT FOR MANGANESE. FINAL REPORT  

EPA Science Inventory

The document evaluates data on occurrence, sources, and transport of manganese in the environment and data on metabolism, pharmacokinetics, laboratory toxicological and epidemiologic studies to determine the nature and dose response relationship of potential health effects on hum...

176

Toenail, Blood and Urine as Biomarkers of Manganese Exposure  

PubMed Central

Objective This study examined the correlation between manganese exposure and manganese concentrations in different biomarkers. Methods Air measurement data and work histories were used to determine manganese exposure over a workshift and cumulative exposure. Toenail samples (n=49), as well as blood and urine before (n=27) and after (urine, n=26; blood, n=24) a workshift were collected. Results Toenail manganese, adjusted for age and dietary manganese, was significantly correlated with cumulative exposure in months 7-9, 10-12, and 7-12 before toenail clipping date, but not months 1-6. Manganese exposure over a work shift was not correlated with changes in blood nor urine manganese. Conclusions Toenails appeared to be a valid measure of cumulative manganese exposure 7 to 12 months earlier. Neither change in blood nor urine manganese appeared to be suitable indicators of exposure over a typical workshift. PMID:21494156

Laohaudomchok, Wisanti; Lin, Xihong; Herrick, Robert F.; Fang, Shona C.; Cavallari, Jennifer M.; Christiani, David C.; Weisskopf, Marc G.

2011-01-01

177

Magnesium and manganese content of halophilic bacteria.  

PubMed

Magnesium and manganese contents were measured by atomic absorption spectrophotometry in bacteria of several halophilic levels, in Vibrio costicola, a moderately halophilic eubacterium growing in 1 M NaCl, Halobacterium volcanii, a halophilic archaebacterium growing in 2.5 M NaCl, Halobacterium cutirubrum, an extremely halophilic archaebacterium growing in 4 M NaCl, and Escherichia coli, a nonhalophilic eubacterium growing in 0.17 M NaCl. Magnesium and manganese contents varied with the growth phase, being maximal at the early log phase. Magnesium and manganese molalities in cell water were shown to increase with the halophilic character of the logarithmically growing bacteria, from 30 mmol of Mg per kg of cell water and 0.37 mmol of Mn per kg of cell water for E. coli to 102 mmol of Mg per kg of cell water and 1.6 mmol of Mn per kg of cell water for H. cutirubrum. The intracellular concentrations of manganese were determined independently by a radioactive tracer technique in V. costicola and H. volcanii. The values obtained by Mn loading represented about 70% of the values obtained by atomic absorption. The increase of magnesium and manganese contents associated with the halophilic character of the bacteria suggests that manganese and magnesium play a role in haloadaptation. PMID:16347151

Mdicis, E D; Paquette, J; Gauthier, J J; Shapcott, D

1986-09-01

178

Development of new nanocomposite based on nanosized-manganese oxide and carbon nanotubes for high performance electrochemical capacitors  

Microsoft Academic Search

We report the synthesis of a new composite electrode based on nanosized-manganese oxide and carbon nanotubes (CNTs) by electrophoretic deposition of CNTs on a stainless steel (SS) substrate followed by direct spontaneous reduction of MnO4? ions to MnO2 to form the multi-scaled SSCNTMnO2 electrode. The resulting material was characterized by scanning electron microscopy, energy dispersive X-ray analysis, cyclic voltammetry and

Tarik Bordjiba; Daniel Blanger

2010-01-01

179

Pathophysiology of manganese-associated neurotoxicity.  

PubMed

Manganese (Mn) is a well established neurotoxin associated with specific damage to the basal ganglia in humans. The phenotype associated with Mn neurotoxicity was first described in two workers with occupational exposure to Mn oxide (Couper, 1837). Although the description did not use modern clinical terminology, a parkinsonian illness characterized by slowness of movement (bradykinesia), masked facies, and gait impairment (postural instability) appears to have predominated. Nearly 100 years later an outbreak of an atypical parkinsonian illness in a Chilean Mn mine provided a phenotypic description of a fulminant neurologic disorder with parkinsonism, dystonia, and neuropsychiatric symptoms (Rodier, 1955). Exposures associated with this syndrome were massive and an order of magnitude greater than modern exposures (Rodier, 1955; Hobson et al., 2011). The clinical syndrome associated with Mn neurotoxicity has been called manganism. Modern exposures to Mn occur primarily through occupations in the steel industry and welding. These exposures are often chronic and varied, occurring over decades in the healthy workforce. Although the severe neurologic disorder described by Rodier and Couper are no longer seen, several reports have suggested a possible increased risk of neurotoxicity in these workers (Racette et al., 2005b; Bowler et al., 2007; Harris et al., 2011). Based upon limited prior imaging and pathologic investigations into the pathophysiology of neurotoxicity in Mn exposed workers (Huang et al., 2003), many investigators have concluded that the syndrome spares the dopamine system distinguishing manganism from Parkinson disease (PD), the most common cause of parkinsonism in the general population, and a disease with characteristic degenerative changes in the dopaminergic system (Jankovic, 2005). The purpose of this symposium was to highlight recent advances in the understanding of the pathophysiology of Mn associated neurotoxicity from Caenorhabditis elegans to humans. Dr. Aschner's presentation discussed mechanisms of dopaminergic neuronal toxicity in C. elegans and demonstrates a compelling potential role of Mn in dopaminergic degeneration. Dr. Guilarte's experimental, non-human primate model of Mn neurotoxicity suggests that Mn decreases dopamine release in the brain without loss of neuronal integrity markers, including dopamine. Dr. Racette's presentation demonstrates a unique pattern of dopaminergic dysfunction in active welders with chronic exposure to Mn containing welding fumes. Finally, Dr. Dydak presented novel magnetic resonance (MR) spectroscopy data in Mn exposed smelter workers and demonstrated abnormalities in the thalamus and frontal cortex for those workers. This symposium provided some converging evidence of the potential neurotoxic impact of Mn on the dopaminergic system and challenged existing paradigms on the pathophysiology of Mn in the central nervous system. PMID:22202748

Racette, Brad A; Aschner, Michael; Guilarte, Tomas R; Dydak, Ulrike; Criswell, Susan R; Zheng, Wei

2012-08-01

180

Position-dependent effect of non-magnetic impurities on superconducting properties of nanowires  

NASA Astrophysics Data System (ADS)

Anderson's theorem states that non-magnetic impurities do not change the bulk properties of conventional superconductors. However, as the dimensionality is reduced, the effect of impurities becomes more significant. Here we investigate superconducting nanowires with diameter comparable to the Fermi wavelength ?F (which is less than the superconducting coherence length) by using a microscopic description based on the Bogoliubov-de Gennes method. We find that: 1) impurities strongly affect the superconducting properties, 2) the effect is impurity position dependent, and 3) it exhibits opposite behavior for resonant and off-resonant wire widths. We show that this is due to the interplay between the shape resonances of the order parameter and the subband energy spectrum induced by the lateral quantum confinement. These effects can be used to manipulate the Josephson current, filter electrons by subband and investigate the symmetries of the superconducting subband gaps.

Zhang, L.-F.; Covaci, L.; Peeters, F. M.

2015-01-01

181

Spin-polarized electron transport through a non-magnetic double barrier semiconductor heterostructure [rapid communication  

NASA Astrophysics Data System (ADS)

The spin-polarized electron resonant tunneling at zero magnetic field through a double barrier hetero structure of non-magnetic III V semiconductor is theoretically investigated within the envelop function approximation and the Kane model for the bulk. An elegant model is proposed to study the combined effects of Dresselhaus and in-plane Rashba spin orbit interactions on the spin-dependent tunneling through double barriers of strained hetero structures. Enhanced degree of spin-polarization and easily tunable wider range of energy for a specific polarization are predicted. We estimate that the polarization can reach cent percent with moderate applied electric field. Our investigations show that spin-relaxation can be suppressed by compensating the bulk and structural inversion symmetries using appropriate electric potential. This effect could be engineered in the fabrication of spin-dependent optoelectronic devices.

Gnanasekar, K.; Navaneethakrishnan, K.

2005-06-01

182

Biogeochemical cycling of manganese in Oneida Lake, New York: whole lake studies of manganese  

NASA Technical Reports Server (NTRS)

Oneida Lake, New York is a eutrophic freshwater lake known for its abundant manganese nodules and a dynamic manganese cycle. Temporal and spatial distribution of soluble and particulate manganese in the water column of the lake were analyzed over a 3-year period and correlated with other variables such as oxygen, pH, and temperature. Only data from 1988 are shown. Manganese is removed from the water column in the spring via conversion to particulate form and deposited in the bottom sediments. This removal is due to biological factors, as the lake Eh/pH conditions alone can not account for the oxidation of the soluble manganese Mn(II). During the summer months the manganese from microbial reduction moves from the sediments to the water column. In periods of stratification the soluble Mn(II) builds up to concentrations of 20 micromoles or more in the bottom waters. When mixing occurs, the soluble Mn(II) is rapidly removed via oxidation. This cycle occurs more than once during the summer, with each manganese atom probably being used several times for the oxidation of organic carbon. At the end of the fall, whole lake concentrations of manganese stabilize, and remain at about 1 micromole until the following summer, when the cycle begins again. Inputs and outflows from the lake indicate that the active Mn cycle is primarily internal, with a small accumulation each year into ferromanganese nodules located in the oxic zones of the lake.

Aguilar, C.; Nealson, K. H.

1998-01-01

183

Managing the manganese: molecular mechanisms of manganese transport and homeostasis.  

PubMed

Manganese (Mn) is an essential metal nutrient for plants. Recently, some of the genes responsible for transition metal transport in plants have been identified; however, only relatively recently have Mn2+ transport pathways begun to be identified at the molecular level. These include transporters responsible for Mn accumulation into the cell and release from various organelles, and for active sequestration into endomembrane compartments, particularly the vacuole and the endoplasmic reticulum. Several transporter gene families have been implicated in Mn2+ transport, including cation/H+ antiporters, natural resistance-associated macrophage protein (Nramp) transporters, zinc-regulated transporter/iron-regulated transporter (ZRT/IRT1)-related protein (ZIP) transporters, the cation diffusion facilitator (CDF) transporter family, and P-type ATPases. The identification of mutants with altered Mn phenotypes can allow the identification of novel components in Mn homeostasis. In addition, the characterization of Mn hyperaccumulator plants can increase our understanding of how plants can adapt to excess Mn, and ultimately allow the identification of genes that confer this stress tolerance. The identification of genes responsible for Mn2+ transport has substantially improved our understanding of plant Mn homeostasis. PMID:16101910

Pittman, Jon K

2005-09-01

184

Study of high performance alloy electroforming. [nickel manganese and nickel cobalt manganese alloys  

NASA Technical Reports Server (NTRS)

Nickel-manganese alloy electrodeposits from an electrolyte containing more manganese ion than previously used is being evaluated at two bath operating temperatures with a great variety of pulse plating conditions. Saccharine was added as a stress reducing agent for the electroforming of several of the samples with highest manganese content. All specimens for mechanical property testing have been produced but are not through the various heat treatments as yet. One of the heat treatment will be at 343 C (650 F), the temperature at which the MCC outer electroformed nickel shell is stress relieved. A number of retainer specimens from prior work have been tested for hardness before and after heat treatment. There appears to be a fairly good correlation between hardness and mechanical properties. Comparison of representative mechanical properties with hardnesses are made for nickel-manganese electrodeposits and nickel-cobalt-manganese deposits.

Malone, G. A.

1984-01-01

185

Manganese in dwarf spheroidal galaxies  

E-print Network

We provide manganese abundances (corrected for the effect of the hyperfine structure) for a large number of stars in the dwarf spheroidal galaxies Sculptor and Fornax, and for a smaller number in the Carina and Sextans dSph galaxies. Abundances had already been determined for a number of other elements in these galaxies, including alpha and iron-peak ones, which allowed us to build [Mn/Fe] and [Mn/alpha] versus [Fe/H] diagrams. The Mn abundances imply sub-solar [Mn/Fe] ratios for the stars in all four galaxies examined. In Sculptor, [Mn/Fe] stays roughly constant between [Fe/H]\\sim -1.8 and -1.4 and decreases at higher iron abundance. In Fornax, [Mn/Fe] does not vary in any significant way with [Fe/H]. The relation between [Mn/alpha] and [Fe/H] for the dSph galaxies is clearly systematically offset from that for the Milky Way, which reflects the different star formation histories of the respective galaxies. The [Mn/alpha] behavior can be interpreted as a result of the metal-dependent Mn yields of type II and ...

North, P; Jablonka, P; Hill, V; Shetrone, M; Letarte, B; Lemasle, B; Venn, K A; Battaglia, G; Tolstoy, E; Irwin, M J; Primas, F; Francois, P

2012-01-01

186

Transformation kinetics and pathways of tetracycline antibiotics with manganese oxide  

E-print Network

Transformation kinetics and pathways of tetracycline antibiotics with manganese oxide Wan-Ru Chen 1 tetracyclines. ? 2011 Elsevier Ltd. All rights reserved. 1. Introduction Manganese, commonly present as Mn

Huang, Ching-Hua

187

(Data in thousand metric tons, gross weight, unless noted) Domestic Production and Use: Manganese ore containing 35% or more manganese was not produced domestically  

E-print Network

102 MANGANESE (Data in thousand metric tons, gross weight, unless noted) Domestic Production and Use: Manganese ore containing 35% or more manganese was not produced domestically in 1995. Manganese, and as a colorant for brick. Leading identifiable end uses of manganese were construction, machinery

Torgersen, Christian

188

Development of an accelerator based system for in vivo neutron activation analysis measurements of manganese in humans  

NASA Astrophysics Data System (ADS)

Manganese is required by the human body, but as with many heavy elements, in large amounts it can be toxic, producing a neurological disorder similar to that of Parkinson's Disease. The primary industrial uses of the element are for the manufacturing of steel and alkali batteries. Environmental exposure may occur via drinking water or exhaust emissions from vehicles using gasoline with the manganese containing compound MMT as an antiknock agent (MMT has been approved for use in both Canada and the United States). Preclinical symptoms of toxicity have recently been detected in individuals occupationally exposed to airborne manganese at levels below the present threshold limit value set by the EPA. Evidence also suggests that early detection of manganese toxicity is crucial since once the symptoms have developed past a certain point, the syndrome will continue to progress even if manganese exposure ceases. The development of a system for in vivo neutron activation analysis (IVNAA) measurement of manganese levels was investigated, with the goal being to have a means of monitoring both over exposed and manganese deficient populations. The McMaster KN-accelerator was used to provide low-energy neutrons, activation within an irradiation site occurred via the 55Mn(n,gamma) 56Mn capture reaction, and the 847 keV gamma-rays emitted when 56Mn decayed were measured using one or more Nal(TI) detectors. The present data regarding manganese metabolism and storage within the body are limited, and it is unclear what the optimal measurement site would be to provide a suitable biomarker of past exposure. Therefore the feasibility of IVNAA measurements in three sites was examined---the liver, brain and hand bones. Calibration curves were derived, minimum detectable limits determined and resulting doses calculated for each site (experimentally in the case of the liver and hand bones, and through computer simulations for the brain). Detailed analytical calculations of the 7Li(p,n) 7Be reaction, used to produce neutrons by the KN, were conducted to determine neutron spectral information, angular distributions and yields. These data were used as input for the transport code MCNP, and computer simulations of experimental conditions were performed. The simulations consistently overestimate experiment measurements by a constant factor, and possible reasons for this discrepancy are discussed. It has been concluded that IVNAA measurements of the brain would only provide limited information, however, measurement of both the liver and hand bone should be possible. It is recommended that preliminary in vivo measurements be pursued for the hand, as metabolic data suggest that bone may be a long term storage site for manganese.

Arnold, Michelle Lynn

2001-11-01

189

Original Research Manganese-Enhanced MRI Reveals Multiple  

E-print Network

Original Research Manganese-Enhanced MRI Reveals Multiple Cellular and Vascular Layers in Normal,6* Purpose: To use manganese-enhanced magnetic reso- nance imaging (MEMRI) at 25 ? 25 ? 800 mm3 to image different retinal and vascular layers in the rat retinas. Materials and Methods: Manganese

Duong, Timothy Q.

190

Arsenite Oxidation by a Poorly Crystalline Manganese-Oxide. 2.  

E-print Network

Arsenite Oxidation by a Poorly Crystalline Manganese-Oxide. 2. Results from X-ray Absorption September 23, 2010. Accepted October 1, 2010. Arsenite (AsIII ) oxidation by manganese oxides (Mn Manganese-oxides (Mn-oxides) commonly occur as fine- grained particles or coatings in terrestrial

Sparks, Donald L.

191

Directed Vapor Deposition of Lithium Manganese Oxide Films  

E-print Network

Directed Vapor Deposition of Lithium Manganese Oxide Films A Dissertation Presented to the faculty the deposition of lithium manganese oxide films. Many phases with offering various electrochemical performance techniques. As-deposited lithium manganese oxide films grown on substrates at ambient temperature using high

Wadley, Haydn

192

High manganese concentrations in rocks at Gale crater, Mars  

E-print Network

High manganese concentrations in rocks at Gale crater, Mars Nina L. Lanza1 , Woodward W. Fischer2 to iron, manganese is sensitive only to high redox potential oxidants, and when concentrated in rocks on the Curiosity rover indicate abundances of manganese in and on some rock targets that are 1­2 orders

193

Pwave Pairing and Colossal Magnetoresistance in Manganese Oxides  

E-print Network

P­wave Pairing and Colossal Magnetoresistance in Manganese Oxides Yong­Jihn Kim y Department that the existing experimental data of most manganese ox­ ides show the frustrated p­wave superconducting paid to the manganese oxides since the observa­ tion of colossal magnetoresistance (CMR). 1\\Gamma4

194

EFFECT OF MANGANESE ON GROI,IIHOF SPHAEROTILUS  

E-print Network

l-rrE I TLg EFFECT OF MANGANESE ON GROI,IIHOF SPHAEROTILUS DISCOPHORUS THESIS SUB spontaneously oxidize at physiological pH' whereas manganous manganese does not, the latter has been preferred ln modern studies of the problem. Work by Prav6 (f4) suggested that manganese autotrophy night exist

Luther, Douglas S.

195

NEUTRON SCATTERING AND CATION ROTATIONAL MOTION IN TETRAMETHYLAMMONIUM MANGANESE CHLORIDE  

E-print Network

473 NEUTRON SCATTERING AND CATION ROTATIONAL MOTION IN TETRAMETHYLAMMONIUM MANGANESE CHLORIDE B sample of tetramethylammonium manganese chloride has been measured for 0-500 cm-1energy transfers, both ammonium manganese chloride, (CH3)4MnCl3 exhibits the properties of a one-dimen- sional anti-ferro magnet

Paris-Sud XI, Université de

196

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

E-print Network

Terrestrial manganese-53 -- A new monitor of Earth surface processes Joerg M. Schaefer a,, Thomas 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

Winckler, Gisela

197

Kinetic Modeling of Oxidation of Antibacterial Agents by Manganese  

E-print Network

Kinetic Modeling of Oxidation of Antibacterial Agents by Manganese Oxide H U I C H U N Z H A N G demonstratedinearlierstudiestobehighlysusceptibletooxidation by manganese oxides, a common oxidant in soils. However, because of the high complexity of oxidative transformation of organic contaminants by manganese oxides in well-defined systems. Introduction

Huang, Ching-Hua

198

Arsenite Oxidation by a Poorly Crystalline Manganese-Oxide 1.  

E-print Network

Arsenite Oxidation by a Poorly Crystalline Manganese-Oxide 1. Stirred-Flow Experiments B R A N D O September 23, 2010. Accepted October 1, 2010. Manganese-oxides (Mn-oxides) are quite reactive, with respect of studying reaction mechanisms over time. Introduction Manganese-oxide minerals (Mn-oxides) are powerful

Sparks, Donald L.

199

Essentiality, Toxicity and Uncertainty in the Risk Assessment of Manganese  

EPA Science Inventory

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 quant...

200

Silver manganese oxide electrodes for lithium batteries  

DOEpatents

This invention relates to electrodes for non-aqueous lithium cells and batteries with silver manganese oxide positive electrodes, denoted AgxMnOy, in which x and y are such that the manganese ions in the charged or partially charged electrodes cells have an average oxidation state greater than 3.5. The silver manganese oxide electrodes optionally contain silver powder and/or silver foil to assist in current collection at the electrodes and to improve the power capability of the cells or batteries. The invention relates also to a method for preparing AgxMnOy electrodes by decomposition of a permanganate salt, such as AgMnO4, or by the decomposition of KMnO4 or LiMnO4 in the presence of a silver salt.

Thackeray, Michael M.; Vaughey, John T.; Dees, Dennis W.

2006-05-09

201

Manganese in dwarf spheroidal galaxies  

NASA Astrophysics Data System (ADS)

We provide manganese abundances (corrected for the effect of the hyperfine structure) for a large number of stars in the dwarf spheroidal galaxies Sculptor and Fornax, and for a smaller number in the Carina and Sextans dSph galaxies. Abundances had already been determined for a number of other elements in these galaxies, including ? and iron-peak ones, which allowed us to build [Mn/Fe] and [Mn/?] versus [Fe/H] diagrams. The Mn abundances imply sub-solar [Mn/Fe] ratios for the stars in all four galaxies examined. In Sculptor, [Mn/Fe] stays roughly constant between [Fe/H] ~ -1.8 and -1.4 and decreases at higher iron abundance. In Fornax, [Mn/Fe] does not vary in any significant way with [Fe/H]. The relation between [Mn/?] and [Fe/H] for the dSph galaxies is clearly systematically offset from that for the Milky Way, which reflects the different star formation histories of the respective galaxies. The [Mn/?] behavior can be interpreted as a result of the metal-dependent Mn yields of Type II and Type Ia supernovae. We also computed chemical evolution models for star formation histories matching those determined empirically for Sculptor, Fornax, and Carina, and for the Mn yields of SNe Ia, which were assumed to be either constant or variable with metallicity. The observed [Mn/Fe] versus [Fe/H] relation in Sculptor, Fornax, and Carina can be reproduced only by the chemical evolution models that include a metallicity-dependent Mn yield from the SNe Ia. Based on observations made with the FLAMES-GIRAFFE multi-object spectrograph mounted on the Kuyen VLT telescope at ESO-Paranal Observatory (programs 171.B-0588, 074.B-0415 and 076.B-0146).Appendices are available in electronic form at http://www.aanda.org

North, P.; Cescutti, G.; Jablonka, P.; Hill, V.; Shetrone, M.; Letarte, B.; Lemasle, B.; Venn, K. A.; Battaglia, G.; Tolstoy, E.; Irwin, M. J.; Primas, F.; Franois, P.

2012-05-01

202

Bacterial manganese reduction and growth with manganese oxide as the sole electron acceptor  

NASA Technical Reports Server (NTRS)

Microbes that couple growth to the reduction of manganese could play an important role in the biogeochemistry of certain anaerobic environments. Such a bacterium, Alteromonas putrefaciens MR-1, couples its growth to the reduction of manganese oxides only under anaerobic conditions. The characteristics of this reduction are consistent with a biological, and not an indirect chemical, reduction of manganese, which suggest that this bacterium uses manganic oxide as a terminal electron acceptor. It can also utilize a large number of other compounds as terminal electron acceptors; this versatility could provide a distinct advantage in environments where electron-acceptor concentrations may vary.

Myers, Charles R.; Nealson, Kenneth H.

1988-01-01

203

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. PMID:19699328

Whittaker, James W.

2009-01-01

204

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

205

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.; Pailhs, S.; Bouzerar, G.

2011-11-01

206

Instability of a magnetoelastic layer resting on a non-magnetic substrate  

NASA Astrophysics Data System (ADS)

Magnetorheological elastomers (MREs) are ferromagnetic particle impregnated rubbers whose mechanical properties are altered by the application of external magnetic fields. Due to their coupled magneto-mechanical response, MREs are finding an increasing number of engineering applications. One such application is in haptics, where the goal is to actively control surface roughness. One way to achieve this is by exploiting the unstable regime of MRE substrate/layer assemblies subjected to transverse magnetic fields. In this work, we study the response of such an assembly subjected to a transverse magnetic field and in-plane stress. The layer is made up of a transversely isotropic MRE material, whose energy density has been obtained experimentally, while the substrate is a non-magnetic isotropic pure polymer/gel. An analytical solution to this problem based on a general, finite strain, 2D continuum modeling for both the MRE layer and the substrate shows that for adequately soft substrates there is a finite-wavelength buckling mode under a transverse magnetic field. Moreover, the critical magnetic field can be substantially reduced in the presence of a compressive stress of the assembly, thus opening the possibility for haptic applications operating under low magnetic fields.

Danas, K.; Triantafyllidis, N.

2014-09-01

207

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

208

Rotating field eddy current probe for characterization of cracking in non-magnetic tubing  

SciTech Connect

A rotating field eddy current probe was built and tested for use in small diameter, non-magnetic tubing. The rotating field probe is a driver/pickup style with two orthogonally wound drive coils and a pancake pickup coil. The driver coils are excited by two sine waves 90{degree} out of phase with each other. The physical arrangement of the drive coils and the 90{degree} phase shift of the excitation waveforms creates a field which rotates in the test piece under the drive coils. Preliminary tests on electrical discharge machined (EDM) notches show that phased based estimates of notch depth are possible. Probes currently used for detection of cracks in tubing produce responses that have proven unreliable for estimating defect depths. This recently developed version of the rotating field eddy current probe produces a bipolar response in the presence of a crack or a notch. Typically, the phase angle of a bipolar eddy current response is easily identified and measured and is used extensively for estimating depths of volumetric defects. Data are shown relating the phase angle of the rotating field probe`s bipolar response to the depth of circumferential EDM notches.

Capobianco, T.E. [Lockheed Martin, Schenectady, NY (United States)

1998-07-01

209

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.

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

2013-05-01

210

Non-magnetic impurities to induce magnetism in ?-PbO crystal structure  

NASA Astrophysics Data System (ADS)

A new route to d0 magnetism is established with the help of the first-principles methods. Non-magnetic elements in groups 13 and 14 of the periodic table are found to act as the magnetic centers upon embedding in polycrystalline ?-PbO structure. Thus, the local magnetic moment is generated on the impurity site (1.0\\mu_B and 2.0\\mu_B for elements in groups 13 and 14, respectively) due to p orbitals partially filled with electrons whose on-site spin ordering is governed by the first Hund's rule. The magnetic interactions between impurities are controlled by occupation of the p orbitals so that antiferromagnetic (AFM) ordering occurs between impurities of 2.0\\mu_B while ferromagnetic (FM) ordering occurs between impurities possessing 1.0\\mu_B . With respect to the strength of the magnetic interactions, the atomic radius of impurity is found to be a key element to tune the wave function tails of localized electrons: with the reduction of the atomic radius, the on-site stability of the spin-polarized state grows while losing in the long-range order interactions. However, it has been shown that a suppression of the long-range order interactions can be compensated by higher impurity concentration that is allowed by the shift of the solubility limit to higher magnitude.

Berashevich, J.; Reznik, A.

2013-11-01

211

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

212

Steels for parts of the propulsion system of industrial caterpillar tractors  

Microsoft Academic Search

New steels were developed for the track shoes and track links of tractors used for the mining of ore, coal, and gold and for the construction of gas and oil lines in the Soviet Union. Steels 40KhFR (for the shoes) and 40GMFR (for the links), alloyed with chromium (up to 1.0%) or manganese (up to 1.2%) with additional microalloying with

G. V. Spirkina; L. B. Efimova

1988-01-01

213

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

214

Manganese ore tailing: optimization of acid leaching conditions and recovery of soluble manganese.  

PubMed

Manganese recovery from industrial ore processing waste by means of leaching with sulfuric acid was the objective of this study. Experimental conditions were optimized by multivariate experimental design approaches. In order to study the factors affecting leaching, a screening step was used involving a full factorial design with central point for three variables in two levels (2(3)). The three variables studied were leaching time, concentration of sulfuric acid and sample amount. The three factors screened were shown to be relevant and therefore a Doehlert design was applied to determine the best working conditions for leaching and to build the response surface. By applying the best leaching conditions, the concentrations of 12.80 and 13.64 %w/w of manganese for the global sample and for the fraction -44 + 37 ?m, respectively, were found. Microbeads of chitosan were tested for removal of leachate acidity and recovering of soluble manganese. Manganese recovery from the leachate was 95.4%. Upon drying the leachate, a solid containing mostly manganese sulfate was obtained, showing that the proposed optimized method is efficient for manganese recovery from ore tailings. PMID:25284800

Santos, Olvia de Souza Heleno; Carvalho, Cornlio de Freitas; Silva, Gilmare Antnia da; Santos, Cludio Gouva Dos

2015-01-01

215

ADVERSE HEALTH EFFECTS FROM ENVIRONMENTAL MANGANESE EXPOSURE.  

EPA Science Inventory

The ubiquitous element, manganese (Mn), is an essential nutrient, but toxic at excessive exposure levels. Therefore, the US EPA set guideline levels for Mn exposure through inhalation (reference concentration-RfC=0.05 ?g/m3) and ingestion (reference dose-RfD=0.14 mg/kg/day (10 mg...

216

Risk Assessment of an Essential Element: Manganese  

Microsoft Academic Search

Manganese (Mn) is an essential element for humans, animals, and plants and is required for growth, development, and maintenance of health. Mn is present in most tissues of all living organisms and is present naturally in rocks, soil, water, and food. High-dose oral, parenteral, or inhalation exposures are associated with increased tissue Mn levels that may lead to development of

Annette B. Santamaria; Sandra I. Sulsky

2010-01-01

217

Manganese-enhanced magnetic resonance imaging (MEMRI)  

Microsoft Academic Search

ABSTRACT: Manganese ion (Mn, with its unique biology, in order to further expand the already broad assortment of useful information that can be measured,by MRI. Such an approach has been continuously developed in the past several years to provide unique tissue contrast, to assess tissue viability, to act as a surrogate marker of calcium influx into cells and to trace

Alan P. Koretsky; Afonso C. Silva

2004-01-01

218

BORON, MANGANESE, MOLYBDENUM, AND OTHER TRACE ELEMENTS  

Technology Transfer Automated Retrieval System (TEKTRAN)

The nutritional importance of each of the mineral elements reviewed in this chapter is considered limited, unclear, or speculative. Three elements can be considered essential for higher animals and humans. These elements are manganese and molybdenum, which are known enzyme cofactors, and boron, whos...

219

21 CFR 73.2775 - Manganese violet.  

Code of Federal Regulations, 2010 CFR

...ammonium pyrophosphate complex having the approximate formula: Mn(III)NH4 P2 O7 . (b) Specifications. Manganese...not more than 1 part per million. Total color, based on Mn content in as is sample, not less than 93 percent....

2010-04-01

220

The Products of Manganese (II) Oxidation  

SciTech Connect

Manganese, the second most abundant transition metal in the earth's crust, exists in a number of oxidation states, among which the II, III, and IV oxidation states are of greatest environmental importance. Produced through microbial activity, manganese oxides help to mediate redox reactions with organic and inorganic compounds and help to sequester a variety of metals. The mechanism by which Manganese (II) is oxidized to Manganese (IV) is a biologically catalyzed process. There are at least three different pathways by which Mn(II) can be bacterially oxidized to Mn(IV); the first in which states that Mn(II) can be oxidized to mixed Mn(III, IV), and Mn(IV) oxides and oxyhydroxides. The second of these pathways is that Mn(II) can be directly oxidized to Mn(IV) and the last of these pathways is that Mn(II) follows an enzymatic bond with a Mn(III) intermediate in which Mn(II) oxidizes to Mn(III) and then to Mn(IV). The pathways of focus for this research are the latter two pathways.

Perkins, A.

2004-09-03

221

Role of manganese in neurodegenerative diseases  

Microsoft Academic Search

Manganese (Mn) is an essential ubiquitous trace element that is required for normal growth, development and cellular homeostasis. Exposure to high Mn levels causes a clinical disease characterized by extrapyramidal symptom resembling idiopathic Parkinson's disease (IPD). The present review focuses on the role of various transporters in maintaining brain Mn homeostasis along with recent methodological advances in real-time measurements of

Aaron B. Bowman; Gunnar F. Kwakye; Elena Herrero Hernndez; Michael Aschner

222

Real time pit initiation studies on stainless steels: The effect of sulphide inclusions  

Microsoft Academic Search

It has long been accepted that manganese sulphide favours pitting on stainless steels. However, there are different standpoints on the most important mechanism for pit initiation; due to dissolution of sulphide inclusions, chromium depletion around the inclusion or mechanical rupture of the passive film by metal chlorides. Analysing the pitting potential and metastable pitting rates on different grades of stainless

T. L. Sudesh L. Wijesinghe; Daniel John Blackwood

2007-01-01

223

Metallic Oxides with the Structure of High-speed Steel Carbide  

Microsoft Academic Search

OXIDES isomorphous with the high-speed steel carbide Fe3W3C have been found to exist with the ideal composition Me3Ti3O, where Me is one of the transition metals manganese, iron, cobalt, nickel or copper (but not vanadium, chromium or zinc).

Nils Karlsson

1951-01-01

224

Thermodynamic modelling of the formation of zinc-manganese ferrite spinel in electric arc furnace dust.  

PubMed

Electric arc furnace dust is generated when automobile scrap, containing galvanized steel, is remelted in an electric arc furnace. This dust is considered as a hazardous waste in most countries. Zinc is a major component of the dust and can be of significant commercial value. Typically, the majority of the zinc exists as zinc oxide (ZnO) and as a zinc-manganese ferrite spinel ((Zn(x)Mn(y)Fe(1-x-y))Fe(2)O(4)). The recovery of the zinc from the dust in metal recycling and recovery processes, particularly in the hydrometallurgical extraction processes, is often hindered by the presence of the mixed ferrite spinel. However, there is a paucity of information available in the literature on the formation of this spinel. Therefore, in the present research, the equilibrium module of HSC Chemistry 6.1 was utilized to investigate the thermodynamics of the formation of the spinel and the effect of variables on the amount and the composition of the mixed ferrite spinel. It is proposed that the mixed ferrite spinel forms due to the reaction of iron-manganese particulates with both gaseous oxygen and zinc, at the high temperatures in the freeboard of the furnace above the steel melt. Based on the thermodynamic predictions, methods are proposed for minimizing the formation of the mixed ferrite spinel. PMID:20356673

Pickles, C A

2010-07-15

225

Soil Manganese Enrichment from Industrial Inputs: A Gastropod Perspective  

PubMed Central

Manganese is one of the most abundant metal in natural environments and serves as an essential microelement for all living systems. However, the enrichment of soil with manganese resulting from industrial inputs may threaten terrestrial ecosystems. Several studies have demonstrated harmful effects of manganese exposure by cutaneous contact and/or by soil ingestion to a wide range of soil invertebrates. The link between soil manganese and land snails has never been made although these invertebrates routinely come in contact with the upper soil horizons through cutaneous contact, egg-laying, and feeding activities in soil. Therefore, we have investigated the direct transfer of manganese from soils to snails and assessed its toxicity at background concentrations in the soil. Juvenile Cantareus aspersus snails were caged under semi-field conditions and exposed first, for a period of 30 days, to a series of soil manganese concentrations, and then, for a second period of 30 days, to soils with higher manganese concentrations. Manganese levels were measured in the snail hepatopancreas, foot, and shell. The snail survival and shell growth were used to assess the lethal and sublethal effects of manganese exposure. The transfer of manganese from soil to snails occurred independently of food ingestion, but had no consistent effect on either the snail survival or shell growth. The hepatopancreas was the best biomarker of manganese exposure, whereas the shell did not serve as a long-term sink for this metal. The kinetics of manganese retention in the hepatopancreas of snails previously exposed to manganese-spiked soils was significantly influenced by a new exposure event. The results of this study reveal the importance of land snails for manganese cycling in terrestrial biotopes and suggest that the direct transfer from soils to snails should be considered when precisely assessing the impact of anthropogenic Mn releases on soil ecosystems. PMID:24454856

Bordean, Despina-Maria; Nica, Dragos V.; Harmanescu, Monica; Banatean-Dunea, Ionut; Gergen, Iosif I.

2014-01-01

226

Non-magnetic Iron Rich Microspherules from Younger Dryas Boundary Layer  

NASA Astrophysics Data System (ADS)

We report the discovery of abundance peaks of high-temperature non-magnetic spherules at 3 sites that date at or close to the onset of the Younger Dryas (YD) cooling episode at 12.9 0.1 kiloannum. Two sites (Gainey and Blackwater Draw) exhibit human cultural artifact sequences that rank them among the premier end-Pleistocene archeological locations. The third site has been discovered in southern part of Czech Republic within the sedimentary record of paleolake Svarcenberk. The spherules, sometimes associated with high temperature melt-glass, are found in the Younger Dryas boundary (YDB) layer proposed to have resulted from a cosmic impact/airburst (Firestone et al., 2007). That event was posited to have triggered Younger Dryas cooling, contributed to megafaunal extinctions, and led to human cultural shifts and population decreases across the Northern Hemisphere. Reports of peak abundances in YDB impact-related spherules have been confirmed by several independent groups, but disputed by several others. We have performed geochemical analyses with energy dispersive x-ray spectroscopy on YDB spherules, supported by examination of surface ultrastructures by scanning electron microscope. These analyses demonstrate that the spherules were not formed through volcanic, cosmic, anthropogenic, biogenic, or authigenic processes. Instead, they are comprised of high-temperature mineral phases of terrestrial source rocks and sediments. They are also geochemically similar to spherules, melted glass tektites, and impact ejecta recovered from twelve known impact craters and strewnfields, including the Australasian tektite field (780 kiloannum) and the Cretaceous-Paleogene impact layer (65 million years), supporting the hypothesis that they formed by cosmic impact. Magnetic analyses performed on spherules allowed separation of microspherules into two groups. Group A with enhanced coercivity corresponds to microspheres composed of nanosphere agglomerates with high silica content. Group B with low susceptibility corresponds to crystallized microspheres. Magnetic signature of both groups show that their genesis is not connected with lightning discharge and rather confirms magnetization in ambient geomagnetic field.

Kletetschka, G.; Nabelek, L.; Svitavska-Sokolova, H.; Kadlec, J.; Bunch, T. E.; West, A.; Firestone, R. B.

2013-05-01

227

Numerical simulation of the three-dimensional structure and dynamics of the non-magnetic solar chromosphere  

Microsoft Academic Search

Three-dimensional numerical simulations with CO5, a new radiation hydrodynamics code, result in a dynamic, thermally bifurcated model of the non-magnetic chromosphere of the quiet Sun. The 3D model includes the middle and low chromosphere, the photosphere, and the top of the convection zone, where acoustic waves are excited by convective motions. While the waves propagate upwards, they steepen into shocks,

Sven Wedemeyer; Bernd Freytag; Matthias Steffen; H.-G. Ludwig; Hartmut Holweger

2004-01-01

228

Topologically Constrained Manganese(III) and Iron(III) Complexes of Two Cross-Bridged Tetraazamacrocycles  

E-print Network

Topologically Constrained Manganese(III) and Iron(III) Complexes of Two Cross prepared by the chemical oxidation of the divalent manganese and iron analogues. The ligands are ethylene for the complexes with manganese(III). The manganese chemistry of 1 was studied in depth. The dichloro manganese

Hubin, Tim

229

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

230

Manganese binding proteins in human and cow's milk  

SciTech Connect

Manganese nutrition in the neonatal period is poorly understood, due in part to a lack of information on the amount of manganese in infant foods and its bioavailability. Since the molecular localization of an element in foods is one determinant of its subsequent bioavailability, a study was made of the binding of manganese in human and cow's milk. An extrinsic label of /sup 54/Mn was shown to equilibrate isotopically with native manganese in milks and formulas. Milk samples were separated into fat, casein and whey by ultracentrifugation. In human milk, the major part (71%) of manganese was found in whey, 11% in casein and 18% in the lipid fraction. In contrast, in cow's milk, 32% of total manganese was in whey, 67% in casein and 1% in lipid. Within the human whey fraction, most of the manganese was bound to lactoferrin, while in cow's whey, manganese was mostly complexed to ligands with molecular weights less than 200. The distribution of manganese in formulas was closer to that of human milk than of cow's milk. The bioavailability of manganese associated with lactoferrin, casein and low molecular weight complexes needs to be assessed.

Loennerdal, B.; Keen, C.L.; Hurley, L.S.

1985-03-01

231

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

232

Induction of oxidative stress and inflammatory cytokines by manganese chloride in cultured T98G cells, human brain glioblastoma cell line.  

PubMed

Manganese, an essential trace nutrient in human beings, has been widely used in the steel industry to improve hardness, stiffness, and strength. With the increased applications of manganese compounds, discharge into the environment has rapidly increased and may exert adverse effects on human health. In this study, manganese toxicity was investigated using cultured T98G cells, which are derived from human glioblasts with the ability to differentiate into several different types of neuroglia. Cytotoxicity was shown in manganese-treated groups (100, 200, 400, and 800microM of MnCl(2)), and cell viability was decreased to 58.8% of the control group at 2days after treatment with 800microM of MnCl(2). When cells were treated with manganese for 24h, ROS dose-dependently increased while antioxidant intracellular GSH decreased. With the generation of ROS, the increased activity of caspase-3 was shown, and was followed by chromatin condensation and breakage, which is an indication of the cellular apoptotic process. ROS also triggered pro-inflammatory responses in cultured T98G cells, which were demonstrated by the increased gene expression and protein levels of IL-6 and IL-8. PMID:19815061

Park, Eun-Jung; Park, Kwangsik

2010-03-01

233

Anodic Behaviour of High Nitrogen-Bearing Steel in PEMFC Environments  

SciTech Connect

High nitrogen-bearing stainless steels, AISI Type 201 and AL219, were investigated in simulated polymer electrolyte membrane fuel cell (PEMFC) environments to assess the use of these materials in fuel cell bipolar plate applications. Both steels exhibit better corrosion behavior than 316L steel in the same environments. Type 201 steel shows similar but lower interfacial contact resistance (ICR) than 316L, while AL219 steel shows higher ICR than 316L. X-ray photoelectron spectroscopy (XPS) analysis shows that the air-formed films on Type 201 and AL219 are composed of iron oxides, chromium oxide, and manganese oxide. Iron oxides dominate the composition of the air-formed film, specially the outer layer. Chromium oxide dominates passive films. Surface film thicknesses were estimated. The results suggest that high nitrogen-bearing stainless steels are promising materials for PEMFC bipolar plates.

Wang, H.; Turner, J. A.

2008-02-01

234

VizieR Online Data Catalog: STEREO non-magnetic chemically peculiar stars (Paunzen+, 2013)  

NASA Astrophysics Data System (ADS)

We have analysed the photometric data obtained with the STEREO spacecraft for 558 non-magnetic chemically peculiar (CP) stars to search for rotational and pulsational variability. Applying the Lomb-Scargle and the phase dispersion minimization methods, we have detected photometric variability for 44 objects from which 35 were previously unknown. The new objects are all bright stars on the ecliptic plane (magnitude range 4.7

Paunzen, E.; Wraight, K. T.; Fossati, L.; Netopil, M.; White, G. J.; Bewsher, D.

2014-03-01

235

International Strategic Minerals Inventory summary report; manganese  

USGS Publications Warehouse

Major world resources of manganese, a strategic mineral commodity, are described in this summary report of information in the International Strategic Minerals Inventory {ISMI). ISMI is a cooperative data-collection effort of earth-science and mineral-resource agencies in Australia, Canada, the Federal Republic of Germany, the Republic of South Africa, and the United States of America. This report, designed to be of benefit to policy analysts, contains two parts. Part I presents an overview of the resources and potential supply of manganese on the basis of inventory information. Part II contains tables of some of the geologic information and mineral-resource and production data that were collected by ISMI participants.

DeYoung, John H.; Sutphin, David M.; Cannon, William F.

1984-01-01

236

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

Federal Register 2010, 2011, 2012, 2013, 2014

...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

237

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

238

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

Code of Federal Regulations, 2013 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...

2013-07-01

239

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

Code of Federal Regulations, 2012 CFR

...2012-07-01 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...

2012-07-01

240

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

Code of Federal Regulations, 2012 CFR

...2012-07-01 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...

2012-07-01

241

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

Code of Federal Regulations, 2014 CFR

...2014-07-01 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...

2014-07-01

242

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

Code of Federal Regulations, 2011 CFR

...2011-07-01 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...

2011-07-01

243

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

Code of Federal Regulations, 2014 CFR

...2014-07-01 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...

2014-07-01

244

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

245

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

Code of Federal Regulations, 2011 CFR

...2011-07-01 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...

2011-07-01

246

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

247

40 CFR 721.10529 - Cobalt iron manganese oxide, carboxylic acid-modified (generic).  

Code of Federal Regulations, 2014 CFR

... 2014-07-01 false Cobalt iron manganese oxide, carboxylic acid-modified...Substances 721.10529 Cobalt iron manganese oxide, carboxylic acid-modified...identified generically as cobalt iron manganese oxide, carboxylic...

2014-07-01

248

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

Code of Federal Regulations, 2012 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...

2012-07-01

249

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

Code of Federal Regulations, 2011 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...

2011-07-01

250

40 CFR 721.10529 - Cobalt iron manganese oxide, carboxylic acid-modified (generic).  

Code of Federal Regulations, 2013 CFR

... 2013-07-01 false Cobalt iron manganese oxide, carboxylic acid-modified...Substances 721.10529 Cobalt iron manganese oxide, carboxylic acid-modified...identified generically as cobalt iron manganese oxide, carboxylic...

2013-07-01

251

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

Code of Federal Regulations, 2014 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...

2014-07-01

252

75 FR 70665 - Proposed Significant New Use Rule for Cobalt Lithium Manganese Nickel Oxide  

Federal Register 2010, 2011, 2012, 2013, 2014

...Proposed Significant New Use Rule for Cobalt Lithium Manganese Nickel Oxide AGENCY...for the chemical substance identified as cobalt lithium manganese nickel oxide (CAS No...for the chemical substance identified as cobalt lithium manganese nickel oxide...

2010-11-18

253

The cosmic origin of carbon and manganese  

E-print Network

[ABRIDGED] We have determined carbon abundances for 51 dwarf stars and manganese abundances for 95 dwarf stars in two distinct and well defined stellar populations - the Galactic thin and thick disks. As these two populations have different chemical histories we have been able to, through a differential abundance analysis using high-resolution spectra, constrain the formation sites for carbon and manganese in the Galactic disk(s). The analysis of carbon is based on the forbidden [C I] line at 872.7 nm which is an abundance indicator that is insensitive to errors in the stellar atmosphere parameters. Combining these data with our previously published oxygen abundances, based on the forbidden [O I] line at 630.0 nm, we can form very robust [C/O] ratios that we then used to investigate the origin of carbon and the chemical evolution of the Galactic thin and thick disks..... Our interpretation of our abundance trends is that the sources that are responsible for the carbon enrichment in the Galactic thin and thick disks have operated on a time-scale very similar to those that are responsible for the Fe and Y enrichment (i.e., SNIa and AGB stars, respectively). For manganese, when comparing our Mn abundances with O abundances for the same stars we find that the abundance trends in the stars with kinematics typical of the thick disk can be explained by metallicity dependent yields from SN II. Furthermore, the [Mn/O] versus [O/H] trend in the halo is flat. We conclude that the simplest interpretation of our data is that manganese most likely is produced in SN II and that the Mn yields for such SNae must be metallicity dependent.

Thomas Bensby; Sofia Feltzing

2008-09-24

254

Manganese oxide nanowires, films, and membranes and methods of making  

DOEpatents

Nanowires, films, and membranes comprising ordered porous manganese oxide-based octahedral molecular sieves and methods of making the same are disclosed. A method for forming nanowires includes hydrothermally treating a chemical precursor composition in a hydrothermal treating solvent to form the nanowires, wherein the chemical precursor composition comprises a source of manganese cations and a source of counter cations, and wherein the nanowires comprise ordered porous manganese oxide-based octahedral molecular sieves.

Suib, Steven Lawrence (Storrs, CT); Yuan, Jikang (Storrs, CT)

2011-02-15

255

(Data in thousand metric tons, gross weight, unless otherwise specified) Domestic Production and Use: Manganese ore containing 35% or more manganese was not produced domestically  

E-print Network

106 MANGANESE (Data in thousand metric tons, gross weight, unless otherwise specified) Domestic Production and Use: Manganese ore containing 35% or more manganese was not produced domestically in 2002. Manganese ore was consumed mainly by about 15 firms with plants principally in the Eastern United States

Torgersen, Christian

256

(Data in thousand metric tons gross weight unless otherwise specified) Domestic Production and Use: Manganese ore containing 35% or more manganese was not produced domestically  

E-print Network

102 MANGANESE (Data in thousand metric tons gross weight unless otherwise specified) Domestic Production and Use: Manganese ore containing 35% or more manganese was not produced domestically in 2006. Manganese ore was consumed mainly by eight firms with plants principally in the East and Midwest. Most ore

Torgersen, Christian

257

(Data in thousand metric tons, gross weight unless otherwise specified) Domestic Production and Use: Manganese ore containing 35% or more manganese was not produced  

E-print Network

104 MANGANESE (Data in thousand metric tons, gross weight unless otherwise specified) Domestic Production and Use: Manganese ore containing 35% or more manganese was not produced domestically in 2004. Manganese ore was consumed mainly by about eight firms with plants principally in the Eastern United States

Torgersen, Christian

258

(Data in thousand metric tons gross weight unless otherwise specified) Domestic Production and Use: Manganese ore containing 35% or more manganese was not produced domestically  

E-print Network

104 MANGANESE (Data in thousand metric tons gross weight unless otherwise specified) Domestic Production and Use: Manganese ore containing 35% or more manganese was not produced domestically in 2007. Manganese ore was consumed mainly by eight firms with plants principally in the East and Midwest. Most ore

Torgersen, Christian

259

(Data in thousand metric tons, gross weight, unless otherwise specified) Domestic Production and Use: Manganese ore containing 35% or more manganese was not produced domestically  

E-print Network

102 MANGANESE (Data in thousand metric tons, gross weight, unless otherwise specified) Domestic Production and Use: Manganese ore containing 35% or more manganese was not produced domestically in 2000. Manganese ore was consumed mainly by about 15 firms with plants principally in the Eastern United States

Torgersen, Christian

260

(Data in thousand metric tons, gross weight, unless otherwise specified) Domestic Production and Use: Manganese ore containing 35% or more manganese was not produced domestically  

E-print Network

108 MANGANESE (Data in thousand metric tons, gross weight, unless otherwise specified) Domestic Production and Use: Manganese ore containing 35% or more manganese was not produced domestically in 1998. Manganese ore was consumed mainly by about 15 firms with plants principally in the Eastern and Midwestern

Torgersen, Christian

261

(Data in thousand metric tons, gross weight, unless otherwise specified) Domestic Production and Use: Manganese ore containing 35% or more manganese was not produced domestically  

E-print Network

104 MANGANESE (Data in thousand metric tons, gross weight, unless otherwise specified) Domestic Production and Use: Manganese ore containing 35% or more manganese was not produced domestically in 1996. Manganese ore was consumed mainly by about 15 firms with plants principally in the Eastern and Midwestern

Torgersen, Christian

262

(Data in thousand metric tons, gross weight, unless otherwise specified) Domestic Production and Use: Manganese ore containing 35% or more manganese was not produced  

E-print Network

104 MANGANESE (Data in thousand metric tons, gross weight, unless otherwise specified) Domestic Production and Use: Manganese ore containing 35% or more manganese was not produced domestically in 2003. Manganese ore was consumed mainly by about eight firms with plants principally in the Eastern United States

Torgersen, Christian

263

(Data in thousand metric tons gross weight unless otherwise specified) Domestic Production and Use: Manganese ore containing 35% or more manganese was not produced  

E-print Network

106 MANGANESE (Data in thousand metric tons gross weight unless otherwise specified) Domestic Production and Use: Manganese ore containing 35% or more manganese was not produced domestically in 2005. Manganese ore was consumed mainly by eight firms with plants principally in the East and Midwest. Most ore

Torgersen, Christian

264

(Data in thousand metric tons, gross weight, unless otherwise specified) Domestic Production and Use: Manganese ore containing 35% or more manganese was not produced domestically  

E-print Network

104 MANGANESE (Data in thousand metric tons, gross weight, unless otherwise specified) Domestic Production and Use: Manganese ore containing 35% or more manganese was not produced domestically in 1997. Manganese ore was consumed mainly by about 15 firms with plants principally in the Eastern and Midwestern

Torgersen, Christian

265

(Data in thousand metric tons, gross weight, unless otherwise specified) Domestic Production and Use: Manganese ore containing 35% or more manganese was not produced domestically  

E-print Network

104 MANGANESE (Data in thousand metric tons, gross weight, unless otherwise specified) Domestic Production and Use: Manganese ore containing 35% or more manganese was not produced domestically in 2001. Manganese ore was consumed mainly by about 15 firms with plants principally in the Eastern United States

Torgersen, Christian

266

(Data in thousand metric tons, gross weight, unless otherwise noted) Domestic Production and Use: Manganese ore containing 35% or more manganese was not produced domestically  

E-print Network

106 MANGANESE (Data in thousand metric tons, gross weight, unless otherwise noted) Domestic Production and Use: Manganese ore containing 35% or more manganese was not produced domestically in 1999. Manganese ore was consumed mainly by about 15 firms with plants principally in the Eastern and Midwestern

Torgersen, Christian

267

Microstructure and mechanical behavior of neutron irradiated ultrafine grained ferritic steel  

SciTech Connect

Neutron irradiation effects on ultra-fine grain (UFG) low carbon steel prepared by equal channel angular pressing (ECAP) has been examined. Counterpart samples with conventional grain (CG) sizes have been irradiated alongside with the UFG ones for comparison. Samples were irradiated in the Advanced Test Reactor (ATR) at Idaho National Laboratory (INL) to 1.24 dpa. Atom probe tomography revealed manganese, silicon-enriched clusters in both ECAP and CG steel after neutron irradiation. X-ray quantitative analysis showed that dislocation density in CG increased after irradiation. However, no significant change was observed in UFG steel revealing better radiation tolerance.

Ahmad Alsabbagh; Apu Sarkar; Brandon Miller; Jatuporn Burns; Leah Squires; Douglas Porter; James I. Cole; K. L. Murty

2014-10-01

268

Manganese abundances in Galactic bulge red giants  

E-print Network

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 beween 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. 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. 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. We aim at identifying the chemical evolution of manganese, as a function of metallicity, in the Gala...

Barbuy, B; Zoccali, M; Minniti, D; Renzini, A; Ortolani, S; Gomez, A; Trevisan, M; Dutra, N

2013-01-01

269

Manganese Inhalation as a Parkinson Disease Model  

PubMed Central

The present study examines the effects of divalent and trivalent Manganese (Mn2+/Mn3+) mixture inhalation on mice to obtain a novel animal model of Parkinson disease (PD) inducing bilateral and progressive dopaminergic cell death, correlate those alterations with motor disturbances, and determine whether L-DOPA treatment improves the behavior, to ensure that the alterations are of dopaminergic origin. CD-1 male mice inhaled a mixture of Manganese chloride and Manganese acetate, one hour twice a week for five months. Before Mn exposure, animals were trained to perform motor function tests and were evaluated each week after the exposure. By the end of Mn exposure, 10 mice were orally treated with 7.5?mg/kg L-DOPA. After 5 months of Mn mixture inhalation, striatal dopamine content decreased 71%, the SNc showed important reduction in the number of TH-immunopositive neurons, mice developed akinesia, postural instability, and action tremor; these motor alterations were reverted with L-DOPA treatment. Our data provide evidence that Mn2+/Mn3+ mixture inhalation produces similar morphological, neurochemical, and behavioral alterations to those observed in PD providing a useful experimental model for the study of this neurodegenerative disease. PMID:21209715

Ordoez-Librado, Jos Luis; Anaya-Martnez, Vernica; Gutierrez-Valdez, Ana Luisa; Coln-Barenque, Laura; Montiel-Flores, Enrique; Avila-Costa, Maria Rosa

2011-01-01

270

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

271

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

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 todays most powerful commercial magnets at temperature higher than 200C. Members of PNNLs 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

272

Instrumentation of the variable-angle magneto-optic ellipsometer and its application to M-O media and other non-magnetic films  

NASA Technical Reports Server (NTRS)

A new and comprehensive dielectric tensor characterization instrument is presented for characterization of magneto-optical recording media and non-magnetic thin films. Random and systematic errors of the system are studied. A series of TbFe, TbFeCo, and Co/Pt samples with different composition and thicknesses are characterized for their optical and magneto-optical properties. The optical properties of several non-magnetic films are also measured.

Zhou, Andy F.; Erwin, J. Kevin; Mansuripur, M.

1992-01-01

273

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

274

Manganese-enhanced magnetic resonance microscopy of mineralization  

USGS Publications Warehouse

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 T1, T2 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 MnCl2 and 3 mM CaCl2. A banding pattern of high and low T2 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. ?? 2007 Elsevier Inc. All rights reserved.

Chesnick, I.E.; Todorov, T.I.; Centeno, J.A.; Newbury, D.E.; Small, J.A.; Potter, K.

2007-01-01

275

REGULAR ARTICLE Interaction of nickel and manganese in accumulation  

E-print Network

. Hyperaccumulator. Manganese localization . Nickel localization . Phytoremediation . trichomes Introduction More 1992). Our research consortium has developed commercially feasible phytoremediation and phyto- mining

Sparks, Donald L.

276

Nanostructured manganese oxides as highly active water oxidation catalysts: a boost from manganese precursor chemistry.  

PubMed

We present a facile synthesis of bioinspired manganese oxides for chemical and photocatalytic water oxidation, starting from a reliable and versatile manganese(II) oxalate single-source precursor (SSP) accessible through an inverse micellar molecular approach. Strikingly, thermal decomposition of the latter precursor in various environments (air, nitrogen, and vacuum) led to the three different mineral phases of bixbyite (Mn2 O3 ), hausmannite (Mn3 O4 ), and manganosite (MnO). Initial chemical water oxidation experiments using ceric ammonium nitrate (CAN) gave the maximum catalytic activity for Mn2 O3 and MnO whereas Mn3 O4 had a limited activity. The substantial increase in the catalytic activity of MnO in chemical water oxidation was demonstrated by the fact that a phase transformation occurs at the surface from nanocrystalline MnO into an amorphous MnOx (1manganese oxides including the newly formed amorphous MnOx . Both Mn2 O3 and the amorphous MnOx exhibit tremendous enhancement in oxygen evolution during photocatalysis and are much higher in comparison to so far known bioinspired manganese oxides and calcium-manganese oxides. Also, for the first time, a new approach for the representation of activities of water oxidation catalysts has been proposed by determining the amount of accessible manganese centers. PMID:25044528

Menezes, Prashanth W; Indra, Arindam; Littlewood, Patrick; Schwarze, Michael; Gbel, Caren; Schomcker, Reinhard; Driess, Matthias

2014-08-01

277

VERTEX: manganese transport through oxygen minima  

NASA Astrophysics Data System (ADS)

Manganese transport through a well-developed oxygen minimum was studied off central Mexico (18N, 108W) in October-November 1981 as part of the VERTEX (Vertical Transport and Exchange) research program. Refractory, leachable and dissolved Mn fractions associated with particulates caught in traps set at eight depths (120-1950 m) were analyzed. Particles entering the oxygen minimum had relatively large Mn loads; however, as the particulates sank further into the minimum, total Mn fluxes steadily decreased from 190 nmol m -2 day -1 at 120 m to 36 nmol m -2 day -1 at 400 m. Manganese fluxes then steadily increased in the remaining 800-1950 m, reaching rates of up to 230 nmol m -2 day -1 at 1950 m. Manganese concentrations were also measured in the water column. Dissolved Mn levels < 3.0 nmol kg -1 were consistently observed within the 150-600 m depth interval. In contrast, suspended particulate leachable Mn amounts were especially low at those depths, and never exceeded 0.04 nmol kg -1. The combined water column and particle trap data clearly indicate that Mn is released from particles as they sink through the oxygen minimum. Rate-of-change estimates based on trap flux data yield regeneration rates of up to 0.44 nmol kg -1 yr -1 in the upper oxygen minimum (120-200 m). However, only 30% of the dissolved Mn in the oxygen minimum appears to be from sinking particulate regeneration; the other 70% probably results from continental-slope-release-horizontal-transport processes. Dissolved Mn scavenges back onto particles as oxygen levels begin to increase with depth. Scavenging rates ranging from -0.03 to -0.09 nmol kg -1 yr -1 were observed at depths from 700 to 1950 m. These scavenging rates result in Mn residence times of 16-19 years, and scavenging rate constants on the order of 0.057 yr -1. Manganese removal via scavenging on sinking particles below the oxygen minimum is balanced by Mn released along continental boundaries and transported horizontally via advective-diffusive processes. Manganese appears to be very weakly associated with particulates. Nevertheless, the amounts of Mn involved with sinking biogenic particles are large, and the resulting fluxes are on the same order of magnitude as those necessary to explain the excess Mn accumulating on the sea floor. The overall behavior of Mn observed in this, and other, studies strongly suggests some type of equilibrium occurring between dissolved and particulate phases. This equilibrium appears to shift in direct or indirect response to dissolved oxygen levels.

Martin, John H.; Knauer, George A.

1984-01-01

278

Acceleration of irradiation hardening of low-copper reactor pressure vessel steel observed by means of SANS and tensile testing  

Microsoft Academic Search

Neutron irradiation of low-copper reactor pressure vessel steels containing manganese and nickel gives rise to microstructural changes and a deterioration of mechanical properties. This deterioration apparently progresses slower than in steels containing more than ?0.1 wt% Cu. An acceleration of this process after the accumulation of a threshold fluence caused by the so-called late blooming phases is a matter of

F. Bergner; A. Ulbricht; H.-W. Viehrig

2009-01-01

279

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.

Turnbull, John C.; Kessler, S. William; Eastman, G. Yale

1980-07-01

280

Assessment of the permissible exposure level to manganese in workers exposed to manganese dioxide dust  

Microsoft Academic Search

The prevalence of neuropsychological and respiratory symptoms, lung ventilatory parameters, neurofunctional performances (visual reaction time, eye-hand coordination, hand steadiness, audioverbal short term memory), and several biological parameters (calcium, iron, luteinising hormone (LH), follicle stimulating hormone (FSH), and prolactin concentrations in serum, blood counts, manganese (Mn) concentration in blood and in urine) were examined in a group of workers (n =

H A Roels; P Ghyselen; J P Buchet; E Ceulemans; R R Lauwerys

1992-01-01

281

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

2012-11-01

282

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. PMID:22198285

Whittaker, James W.

2012-01-01

283

Absorption of manganese by rice under flooded and unflooded conditions  

Microsoft Academic Search

Summary Manganese absorption by rice plants under flooded and unflooded conditions, in an upland and a lowland soil was studied. Both under flooded and unflooded conditions the rate of manganese absorption was high during 3rd to 4th week and again during 9th to 10th week.

C. S. Weeraratna

1969-01-01

284

Component masses of young, wide, non-magnetic white dwarf binaries in the Sloan Digital Sky Survey Data Release 7  

NASA Astrophysics Data System (ADS)

We present a spectroscopic component analysis of 18 candidate young, wide, non-magnetic, double-degenerate binaries identified from a search of the Sloan Digital Sky Survey Data Release 7 (DR7). All but two pairings are likely to be physical systems. We show SDSS J084952.47+471247.7 + SDSS J084952.87+471249.4 to be a wide DA + DB binary, only the second identified to date. Combining our measurements for the components of 16 new binaries with results for three similar, previously known systems within the DR7, we have constructed a mass distribution for the largest sample to date (38) of white dwarfs in young, wide, non-magnetic, double-degenerate pairings. This is broadly similar in form to that of the isolated field population with a substantial peak around M 0.6 M?. We identify an excess of ultramassive white dwarfs and attribute this to the primordial separation distribution of their progenitor systems peaking at relatively larger values and the greater expansion of their binary orbits during the final stages of stellar evolution. We exploit this mass distribution to probe the origins of unusual types of degenerates, confirming a mild preference for the progenitor systems of high-field-magnetic white dwarfs, at least within these binaries, to be associated with early-type stars. Additionally, we consider the 19 systems in the context of the stellar initial mass-final mass relation. None appear to be strongly discordant with current understanding of this relationship.

Baxter, R. B.; Dobbie, P. D.; Parker, Q. A.; Casewell, S. L.; Lodieu, N.; Burleigh, M. R.; Lawrie, K. A.; Klebi, B.; Koester, D.; Holland, B. R.

2014-06-01

285

Some factors influencing cadmium-manganese interaction in adult rats  

SciTech Connect

Recent data show that even a low dose of cadmium (20 {mu}g/day/rat) significantly suppresses manganese transduodenal transport when administered during a three-day period. The inhibitory effect of cadmium upon manganese absorption is enhanced by concurrently administered iron-fortified milk diet. This suggests that the (synergistic) action of cadmium and iron upon manganese and the competition between these (three) ions in the intestine depend on their relative concentrations and affinity for the binding sites within the intestinal mucosa. For this reason the authors considered it worthwhile examining whether this inhibitory effect of cadmium would be affected by simultaneously administered manganese-fortified milk. Since the absorption of heavy metals and, at the same time, the demand for manganese is higher in the young than in the old animals, they also studied how this interaction depends upon the animals' age and sex and whether it is the same in the whole small intestine.

Gruden, N.; Matausic, S. (Univ. of Zagreb (Yugoslavia))

1989-07-01

286

An investigation on the sintering behavior of 316L and 17-4PH stainless steel powders for graded composites  

Microsoft Academic Search

This paper presents the densification and microstructure of bilayer structures made from 316L and 17-4PH stainless steels powders during sintering. The requirements for such objects could be magnetic properties at one area of the part and non-magnetic properties at another area of the object. A pressureless solid state sintering method in conjunction with a powder layering technique was used. The

A. Simchi; A. Rota; P. Imgrund

2006-01-01

287

Biogeochemistry of manganese in Lake Matano, Indonesia  

E-print Network

2991, 2011 www.biogeosciences.net/8/2977/2011/ C. Jones et al.: Biogeochemistry of manganese in ferruginous Lake Matano 2985 1 2 m 0 2,500 5,000 7,500 10,000 Voltage 0 50 100 150 200 250 300 Inte nsi ty Mn Fe Cu Cu O C Mn Fe Si Fig. 7. TEM micrograph...). A conceptual model of Mn and O2 water column profiles generally applicable to most stratified aquatic environments (e.g. Lake Vanda, the Black Sea, Lake Bret, etc.) (see Davison, 1993 for a review) is shown in Fig. 1. Reactions controlling...

Jones, C.; Crowe, S.A.; Sturm, A.; Leslie, Karla Louise; MacLean, L.C.W.; Katsev, S.; Henny, C.; Fowle, David A.; Canfield, D.E.

2011-10-26

288

Electron Energy-Loss Safe-Dose Limits for Manganese Valence Measurements in Environmentally Relevant Manganese Oxides  

E-print Network

Relevant Manganese Oxides Kenneth J. T. Livi,*, Brandon Lafferty,,§ Mengqiang Zhu,,# Shouliang Zhang, Anne-Claire Gaillot, and Donald L. Sparks The High-Resolution Analytical Electron Microbeam Facility Houssiniere, BP 32229, 44322 Nantes Cedex 3, France *S Supporting Information ABSTRACT: Manganese (Mn) oxides

Sparks, Donald L.

289

High Temperature Single Crystal X-Ray Diffraction: Structure of Cubic Manganese Iodine and Manganese Bromine Boracites  

NASA Astrophysics Data System (ADS)

The structural parameters of optically controlled cubic manganese iodine boracite, Mn 3B 7O 13I, and manganese bromine boracite, Mn 3B 7O 13Br, have been refined on single crystals at 421 and 580 K, respectively (space group F4 c , Z = 8). In order to perform these measurements, a low-cost heating device, based on a soldering iron heating element, has been used. Cell parameters were found to be 12.3404(3) for manganese iodine boracite and 12.3100(9) for manganese bromine boracite. The cell parameters and the deviation from planarity of the oxygen environment around the metal ion are found to be greater in manganese boracites than in other known cubic boracites.

Crottaz, O.; Kubel, F.; Schmid, H.

1995-11-01

290

Effect of enhanced manganese oxidation in the hyporheic zone on basin-scale geochemical mass balance  

E-print Network

Effect of enhanced manganese oxidation in the hyporheic zone on basin-scale geochemical mass) in enhancing microbially mediated oxidation of dissolved manganese (to form manganese precipitates) in a drainage basin contaminated by copper mining. The fate of manganese is of overall importance to water

291

Effect of enhanced manganese oxidation in the hyporheic zone on basin-scale geochemical mass balance  

Microsoft Academic Search

We determined the role of the hyporheic zone (the subsurface zone where stream water and shallow groundwater mix) in enhancing microbially mediated oxidation of dissolved manganese (to form manganese precipitates) in a drainage basin contaminated by copper mining. The fate of manganese is of overall importance to water quality in Pinal Creek Basin, Arizona, because manganese reactions affect the transport

Judson W. Harvey; Christopher C. Fuller

1998-01-01

292

The cosmic origin of carbon and manganese  

E-print Network

[ABRIDGED] We have determined carbon abundances for 51 dwarf stars and manganese abundances for 95 dwarf stars in two distinct and well defined stellar populations - the Galactic thin and thick disks. As these two populations have different chemical histories we have been able to, through a differential abundance analysis using high-resolution spectra, constrain the formation sites for carbon and manganese in the Galactic disk(s). The analysis of carbon is based on the forbidden [C I] line at 872.7 nm which is an abundance indicator that is insensitive to errors in the stellar atmosphere parameters. Combining these data with our previously published oxygen abundances, based on the forbidden [O I] line at 630.0 nm, we can form very robust [C/O] ratios that we then used to investigate the origin of carbon and the chemical evolution of the Galactic thin and thick disks..... Our interpretation of our abundance trends is that the sources that are responsible for the carbon enrichment in the Galactic thin and thick...

Bensby, Thomas

2008-01-01

293

Thermal chemistry of Mn{sub 2}(CO){sub 10} during deposition of thin manganese films on silicon oxide and on copper surfaces  

SciTech Connect

The surface chemistry of dimanganese decacarbonyl on the native oxide of Si(100) wafers was characterized with the aid of x-ray photoelectron spectroscopy. Initial experiments in a small stainless-steel reactor identified a narrow range of temperatures, between approximately 445 and 465 K, in which the deposition of manganese could be achieved in a self-limiting fashion, as is desirable for atomic layer deposition. Deposition at higher temperatures leads to multilayer growth, but the extent of this Mn deposition reverses at even higher temperatures (about 625 K), and also ifhydrogen is added to the reaction mixture. Extensive decarbonylation takes place below room temperature, but limited C-O bond dissociation and carbon deposition are still seen after high exposures at 625 K. The films deposited at low ({approx}450 K) temperatures are mostly in the form of MnO, but at 625 K that converts to a manganese silicate, and upon higher doses a manganese silicide forms at the SiO{sub 2}/Si(100) interface as well. No metallic manganese could be deposited with this precursor on either silicon dioxide or copper surfaces.

Qin Xiangdong; Sun Huaxing; Zaera, Francisco [Department of Chemistry, University of California, Riverside, California 92521 (United States)

2012-01-15

294

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

295

Influence of manganese on enzyme synthesis and citric acid accumulation in Aspergillus niger  

Microsoft Academic Search

Summary A comparison of citric acid fermentations in manganese-deficient and manganese-containing media showed that manganese strongly influences idiophase metabolism. In the presence of manganese, cell growth increases, sugar consumption is diminished and acidogenesis decreases drastically. An investigation of the key enzymes of glycolysis, the pentosephosphate pathway, TCA-cycle, nitrogen metabolism, and gluconeogenesis indicated that manganese deficiency was accompanied by a repression

C. P. Kubicek; M. Rhr

1977-01-01

296

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

297

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.; Gmez, A.; Trevisan, M.; Dutra, N.

2013-11-01

298

Distributions of Manganese, Iron, and Manganese-Oxidizing Bacteria In Lake Superior Sediments of Different Organic Carbon Content  

NASA Technical Reports Server (NTRS)

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 bacteria and Mn oxidizing bacteria, determined by plating and counting, showed that aerobic (and facultatively aerobic) heterotrophic bacteria were present at the highest concentrations near the surface and decreased steadily with depth, while Mn oxidizing bacteria were concentrations 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, Laurie L.; Nealson, Kenneth H.

1989-01-01

299

Manganese inhibits poly(ADP-ribosyl)ation in human cells: a possible mechanism behind manganese-induced toxicity?  

PubMed

For humans manganese is both an essential trace element and, at higher doses, a toxic metal. Due to the ubiquitous occurrence of manganese in foodstuff, in industrial countries daily dietary uptake is higher as compared to the estimated daily requirement. Therefore manganese deficiency is extremely rare. In contrast chronic manganese toxicity, affecting primarily the central nervous system, is more prevalent. Thus manganese occupational and dietary overexposure has been shown to cause progressive, permanent, neurodegenerative damage, resulting in syndromes similar to idiopathic Parkinson's disease. To date modes of manganese neurotoxic action are poorly understood and in most studies oxidative stress is postulated as the underlying mechanism. The present study searched on the cellular level for a molecular mechanism behind manganese-induced neurotoxicity and investigated bioavailability, cytotoxicity and genotoxicity of MnCl(2), as well as its impact on the DNA damage response in human cells (HeLa S3) in culture. Whereas up to 10 M MnCl(2) showed no induction of DNA strand breaks after 24 h incubation, manganese strongly inhibited H(2)O(2)-stimulated poly(ADP-ribosyl)ation at low, completely non-cytotoxic, for certain human exposure, relevant concentrations starting at 1 M. Thereby inhibition of this essential DNA damage response signalling reaction was not due to a reduced gene expression or protein level of the responsible polymerase PARP-1. Taken together, the results indicate that manganese, under conditions of either overload due to high exposure or disturbed homeostasis, can disturb the cellular response to DNA strand breaks, which has been shown before (S. Katyal and P. J. McKinnon, Mech. Ageing Dev., 2008, 129, 483-491) to result in neurological diseases. PMID:20820627

Bornhorst, Julia; Ebert, Franziska; Hartwig, Andrea; Michalke, Bernhard; Schwerdtle, Tanja

2010-11-01

300

Isotopic evidence for organic matter oxidation by manganese reduction in the formation of stratiform manganese carbonate ore  

USGS Publications Warehouse

Unlike other marine-sedimentary manganese ore deposits, which are largely composed of manganese oxides, the primary ore at Molango (Hidalgo State, Mexico) is exclusively manganese carbonate (rhodochrosite, Mn-calcite, kutnahorite). Stable isotope studies of the carbonates from Molango provide critical new information relevant to the controversy over syngenetic and diagenetic models of stratiform manganese deposit formation. Negative ??13C values for carbonates from mineralized zones at Molango are strongly correlated with manganese content both on a whole rock scale and by mineral species. Whole rock ??13C data fall into three groups: high-grade ore = -16.4 to -11.5%.; manganese-rich, sub-ore-grade = -5.2 to 0%.; and unmineralized carbonates = 0 to +2.5%. (PDB). ??18O data show considerable overlap in values among the three groups: +4.8 to -2.8, -5.4 to -0.3%., and -7.4 to +6.2 (PDB), respectively. Isotopic data for individual co-existing minerals suggest a similar separation of ??13C values: ??13C values from calcite range from -1.1 to +0.7%. (PDB), whereas values from rhodochrosite are very negative, -12.9 to -5.5%., and values from kutnahorite or Mn-calcite are intermediate between calcite and rhodochrosite. 13C data are interpreted to indicate that calcite (i.e. unmineralized carbonate) formed from a normal marine carbon reservoir. However, 13C data for the manganese-bearing carbonates suggest a mixed seawater and organic source of carbon. The presence of only trace amounts of pyrite suggests sulfate reduction may have played a minor part in oxidizing organic matter. It is possible that manganese reduction was the predominant reaction that oxidized organic matter and that it released organic-derived CO2 to produce negative ??13C values and manganese carbonate mineralization. ?? 1988.

Okita, P.M.; Maynard, J.B.; Spiker, E. C.; Force, E.R.

1988-01-01

301

Manganese Neurotoxicity: a Focus on Glutamate Transporters  

PubMed Central

Manganese (Mn) is an essential element that is required in trace amount for normal growth, development as well maintenance of proper function and regulation of numerous cellular and biochemical reactions. Yet, excessive Mn brain accumulation upon chronic exposure to occupational or environmental sources of this metal may lead to a neurodegenerative disorder known as manganism, which shares similar symptoms with idiopathic Parkinsons disease (PD). In recent years, Mn exposure has gained public health interest for two primary reasons: continuous increased usage of Mn in various industries, and experimental findings on its toxicity, linking it to a number of neurological disorders. Since the first report on manganism nearly two centuries ago, there have been substantial advances in the understanding of mechanisms associated with Mn-induced neurotoxicity. This review will briefly highlight various aspects of Mn neurotoxicity with a focus on the role of astrocytic glutamate transporters in triggering its pathophysiology. PMID:24472696

2013-01-01

302

Genetic factors and manganese-induced neurotoxicity.  

PubMed

Manganese (Mn), is a trace metal required for normal physiological processes in humans. Mn levels are tightly regulated, as high levels of Mn result in accumulation in the brain and cause a neurological disease known as manganism. Manganism shares many similarities with Parkinson's disease (PD), both at the physiological level and the cellular level. Exposure to high Mn-containing environments increases the risk of developing manganism. Mn is absorbed primarily through the intestine and then released in the blood. Excessive Mn is secreted in the bile and excreted in feces. Mn enters and exits cells through a number of non-specific importers localized on the cell membrane. Mutations in one of the Mn exporters, SLC30A10 (solute carrier family 30, member 10), result in Mn induced toxicity with liver impairments and neurological dysfunction. Four PD genes have been identified in connection to regulation of Mn toxicity, shedding new light on potential links between manganism and PD. PMID:25136353

Chen, Pan; Parmalee, Nancy; Aschner, Michael

2014-01-01

303

Radiation resistant austenitic stainless steel alloys  

DOEpatents

An austenitic stainless steel alloy, with improved resistance to radiation-induced swelling and helium embrittlement, and improved resistance to thermal creep at high temperatures, consisting essentially of, by weight percent: from 16 to 18% nickel; from 13 to 17% chromium; from 2 to 3% molybdenum; from 1.5 to 2.5% manganese; from 0.01 to 0.5% silicon; from 0.2 to 0.4% titanium; from 0.1 to 0.2% niobium; from 0.1 to 0.6% vanadium; from 0.06 to 0.12% carbon; from 0.01% to 0.03% nitrogen; from 0.03 to 0.08% phosphorus; from 0.005 to 0.01% boron; and the balance iron, and wherein the alloy may be thermomechanically treated to enhance physical and mechanical properties.

Maziasz, Philip J. (Oak Ridge, TN); Braski, David N. (Oak Ridge, TN); Rowcliffe, Arthur F. (Oak Ridge, TN)

1989-01-01

304

Radiation resistant austenitic stainless steel alloys  

DOEpatents

An austenitic stainless steel alloy, with improved resistance to radiation-induced swelling and helium embrittlement, and improved resistance to thermal creep at high temperatures, consisting essentially of, by weight percent: from 16 to 18% nickel; from 13 to 17% chromium; from 2 to 3% molybdenum; from 1.5 to 2.5% manganese; from 0.01 to 0.5% silicon; from 0.2 to 0.4% titanium; from 0.1 to 0.2% niobium; from 0.1 to 0.6% vanadium; from 0.06 to 0.12% carbon; from 0.01 to 0.03% nitrogen; from 0.03 to 0.08% phosphorus; from 0.005 to 0.01% boron; and the balance iron, and wherein the alloy may be thermomechanically treated to enhance physical and mechanical properties. 4 figs.

Maziasz, P.J.; Braski, D.N.; Rowcliffe, A.F.

1987-02-11

305

A ROLE FOR MANGANESE IN OXYGEN EVOLUTION IN PHOTOSYNTHESIS  

E-print Network

Knox, in Primary Processes of Photosynthesis, Topics inProcesses of Photo- synthesis, Topics jn Photosynthesis,process. Manganese has been attractive as an element implicated in the water-splitting reactions of photosynthesis

Sauer, Kenneth

2012-01-01

306

Electrochromic reactions in manganese oxides I. Raman analysis  

SciTech Connect

Like nickel oxide, manganese oxide is a widely studied material in the primary batteries field. The reactions taking place during voltametric cycling of manganese oxides can be determined using in situ Raman spectroscopy. The main difficulty for the oxide identification is to obtain relevant Raman reference spectra because of the many possible compounds and, for some of these compounds, of their instability in the laser beam. As a consequence, several modifications of different tetra-, tri- and divalent manganese oxides and oxyhydroxides were carefully studied. The electrochromic behavior of three types of manganese oxides, two prepared by thermal oxidations and the other by electrochemical deposition, were then compared. The presence of nonstoichiometry in the pristine material was necessary to obtain a reversible electrochromic effect. The reaction during electrochromic cycling is more complicated than a simple passage from MnO[sub 2] to MnOOH.

Bernard, M.C.; Hugot-Le Goff, A.; Thi, B.V. (Univ. Pierre et Marie Curie, Paris (France). UPR 15 du CNRS Physique des Liquides et Electrochimie); Cordoba de Torresi, S. (Univ. Estadual de Campinas (Brazil). Dept. de Fisica Aplicada)

1993-11-01

307

Manganese, Iron, and sulfur cycling in Louisiana continental shelf sediments  

EPA Science Inventory

Sulfate reduction is considered the primary pathway for organic carbon remineralization on the northern Gulf of Mexico Louisiana continental shelf (LCS) where bottom waters are seasonally hypoxic, yet limited information is available on the importance of iron and manganese cyclin...

308

The cause of welding cracks in aircraft steels  

NASA Technical Reports Server (NTRS)

The discussion in this article refers to gas welding of thin-walled parts of up to about 3 mm thickness. It was proven that by restricting the sulphur, carbon, and phosphorous content, and by electric-furnace production of the steel, it was possible in a short time to remove this defect. Weld hardness - i.e., martensite formation and hardness of the overheated zone - has no connection with the tendency to weld-crack development. Si, Cr, Mo, or V content has no appreciable effect, while increased manganese content tends to reduce the crack susceptibility.

Muller, J

1940-01-01

309

Aluminum-manganese-tin alloys with improved pitting corrosion resistance  

Microsoft Academic Search

This invention relates to aluminum alloy compositions that have superior corrosion and pitting resistance. These compositions include small amounts of manganese and tin, with the major constituent being aluminum. Elements such as zinc, titanium, tantalum, and\\/or cobalt can also be added. The manganese content ranges from 0.20 to 2 weight percent and the tin content ranges from 0.20 to 1.5

Tong

1985-01-01

310

Carbothermal Reduction of Manganese Oxide in Different Gas Atmospheres  

Microsoft Academic Search

Carbothermal reduction of manganese oxides was studied in hydrogen, helium, and argon at different temperatures and carbon-to-manganese\\u000a oxide ratios. Isothermal and temperature programmed carbothermal reduction experiments were conducted in a fixed bed reactor\\u000a in a vertical tube furnace, with on-line monitoring of gas composition by the CO-CO2 infrared sensor. The extent of reduction was calculated using the off-gas composition and

Ring Kononov; Oleg Ostrovski; Samir Ganguly

2008-01-01

311

Manganese deposits in Turkey: Distribution, types and tectonic setting  

Microsoft Academic Search

Manganese deposits in Turkey are divided into four main groups on the basis of their age, host rocks and processes of formation. The first is hydrothermalhydrogenetic and rarely diagenetic-type manganese deposits which are chiefly associated with radiolarian chert series. These deposits occur as lenses and small ore beds within ophiolitic melanges zones of Paleo-Tethyan, Karakaya and Neo-Tethyan (North Anatolian and

Hseyin ztrk

1997-01-01

312

Manganese in Texas Soils and its Relation to Crops.  

E-print Network

TEXAS AGRICULTURAL EXPERIMENT STATION A. B. CONNER, DIRECTOR COLLEGE STATION, BRAZOS COUNTY, TEXAS BULLETIN NO. 432 AUGUST, 1931 DIVISION OF CHEMISTRY MANGANESE REL AGRICULTURAL AND MECHANICAL COLLEGE OF TEXAS T. 0. IBTALTOM, President... . ........................................is. 36 BULLETIN NO. 432 AUGUST, 1931 MANGANESE IN TEXAS SOILS AND ITS RELATION TO CROPS* By E. C. CARLYLE It has long been recognized that certain elements (carbon, nitro- gen, oxygen, hydrogen, phosphorus, potassium, calcium, magnesium, sulfur...

Carlyle, E. C. (Elmer Cardinal)

1931-01-01

313

Particulate matter and manganese exposures in Toronto, Canada  

Microsoft Academic Search

Methylcyclopentadienyl manganese tricarbonyl (MMT) is a manganese-based gasoline additive used to enhance automobile performance. MMT has been used in Canadian gasoline for about 20yr. Because of the potential for increased levels of Mn in particulate matter resulting from automotive exhausts, a large-scale population-based exposure study (?1000 participant periods) was conducted in Toronto, Canada, to estimate the distribution of 3-day average

E. D. Pellizzari; C. A. Clayton; C. E. Rodes; R. E. Mason; L. L. Piper; B. Fort; G. Pfeifer; D. Lynam

1999-01-01

314

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

315

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

316

The Molecular Geomicrobiology of Bacterial Manganese(II) Oxidation  

Microsoft Academic Search

\\u000a Manganese is the second most abundant transition metal found in the Earths 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

317

Giant negative magnetoresistance in Manganese-substituted Zinc Oxide  

PubMed Central

We report a large negative magnetoresistance in Manganese-substituted Zinc Oxide thin films. This anomalous effect was found to appear in oxygen-deficient films and to increase with the concentration of Manganese. By combining magnetoresistive measurements with magneto-photoluminescence, we demonstrate that the effect can be explained as the result of a magnetically induced transition from hopping to band conduction where the activation energy is caused by the sp-d exchange interaction. PMID:25783664

Wang, X. L.; Shao, Q.; Zhuravlyova, A.; He, M.; Yi, Y.; Lortz, R.; Wang, J. N.; Ruotolo, A.

2015-01-01

318

Oxygen toxicity in Streptococcus mutans: manganese, iron and superoxide dismutase  

SciTech Connect

When cultured anaerobically in a chemically defined medium that was treated with Chelex-100 to lower its trace metal content, Streptococcus mutans OMZ176 had no apparent requirement for manganese or iron. Manganese or iron was necessary for aerobic cultivation in deep static cultures. During continuous aerobic cultivation in a stirred chemostat, iron did not support the growth rate achieved with manganese. Since the dissolved oxygen level in the chemostat cultures was higher than the final level in the static cultures, manganese may be required for growth at elevated levels. In medium supplemented with manganese, cells grown anaerobically contained a low level of superoxide dismutase (SOD) activity; aerobic cultivation increased SOD activity at least threefold. In iron-supplemented medium, cells grown anaerobically also had low SOD activity; aerobic incubation resulted in little increase in SOD activity. Polyacrylamide gel electrophoresis of the cell extracts revealed a major band and a minor band of SOD activity in the cells grown with manganese; however, cells grown with iron contained a single band of SOD activity with an R/sub f/ value similar to that of the major band found in cells grown with manganese. None of the SOD activity bands were abolished by the inclusion of 2 mM hydrogen peroxide in the SOD activity strain. S. mutans may not produce a separate iron-containing SOD but may insert either iron or manganese into an apo-SOD protein. Alternatively, iron may function in another activity (not SOD) that augments the defense against oxygen toxicity at low SOD levels. 28 references, 3 figures, 1 table.

Martin, M.E.; Strachan, R.C.; Aranha, H.; Evans, S.L.; Salin, M.L.; Welch, B.; Arceneaux, J.E.L.; Byers, B.R.

1984-07-01

319

Giant negative magnetoresistance in Manganese-substituted Zinc Oxide  

NASA Astrophysics Data System (ADS)

We report a large negative magnetoresistance in Manganese-substituted Zinc Oxide thin films. This anomalous effect was found to appear in oxygen-deficient films and to increase with the concentration of Manganese. By combining magnetoresistive measurements with magneto-photoluminescence, we demonstrate that the effect can be explained as the result of a magnetically induced transition from hopping to band conduction where the activation energy is caused by the sp-d exchange interaction.

Wang, X. L.; Shao, Q.; Zhuravlyova, A.; He, M.; Yi, Y.; Lortz, R.; Wang, J. N.; Ruotolo, A.

2015-03-01

320

Erythrocyte antioxidant enzyme activities and lipid peroxidation in the erythrocyte membrane of stainless-steel welders exposed to welding fumes and gases  

Microsoft Academic Search

The erythrocyte antioxidant system (superoxide dismutase, SOD; catalase, CAT) and lipid peroxidation (malondialdehyde, MDA) in the erythrocyte membrane were studied in workers continously exposed to welding fumes and gases, which are thought to be oxidant pollutants. Thirty-five welders using the manual metal arc method on stainless steel and 30 controls were studied. Plasma chromium (Cr), manganese (Mn), and cupper (Cu)

Nalan Imamoglu; Mkerrem-Betl Yerer; Hamiyet Donmez-Altuntas; Recep Saraymen

2008-01-01

321

Failure of Manganese to Protect from Shiga Toxin  

PubMed Central

Shiga toxin (Stx), the main virulence factor of Shiga toxin producing Escherichia coli, is a major public health threat, causing hemorrhagic colitis and hemolytic uremic syndrome. Currently, there are no approved therapeutics for these infections; however manganese has been reported to provide protection from the Stx1 variant isolated from Shigella dysenteriae (Stx1-S) both in vitro and in vivo. We investigated the efficacy of manganese protection from Stx1-S and the more potent Stx2a isoform, using experimental systems well-established for studying Stx: in vitro responses of Vero monkey kidney cells, and in vivo toxicity to CD-1 outbred mice. Manganese treatment at the reported therapeutic concentration was toxic to Vero cells in culture and to CD-1 mice. At lower manganese concentrations that were better tolerated, we observed no protection from Stx1-S or Stx2a toxicity. The ability of manganese to prevent the effects of Stx may be particular to certain cell lines, mouse strains, or may only be manifested at high, potentially toxic manganese concentrations. PMID:23875002

Weiss, Alison A.

2013-01-01

322

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, P.U.P.A.; Abrecth, Mike; Baldwin, Katherine L.; Russell, Robin E.; Pedersen, Joel A.; McKenzie, Debbie

2013-01-01

323

Effect of the strong magnetic field on the magnetic interaction between two non-magnetic particles migrating in a conductive fluid  

Microsoft Academic Search

This paper presents a theoretical analysis of the interaction between two non-magnetic particles migrating in a conductive fluid due to an imposed strong magnetic field. A repulsive force induced by the conductive fluid flow around the particles is first derived and calculated for a concrete example. From the numerical results, a counteracting behavior with the interparticle magnetic dipole-dipole attractive force

Z. Sun; T. Kokalj; M. Guo; F. Verhaeghe; O. Van der Biest; B. Blanpain; K. Van Reusel

2009-01-01

324

Alkane oxidation with manganese substituted polyoxometalates in aqueous media with ozone and the intermediacy of manganese ozonide species  

Microsoft Academic Search

Manganese substituted polyoxometalates (POMs), such as Li12(MnII2ZnW(ZnW9O34)2) were effective catalysts for the oxidation of alkanes to ketones with ozone in an aqueous reaction medium; a green intermediate compound observ- able by UV-VIS and ESR at 278 C was postulated to be a reactive manganese ozonide species. Transition metal substituted polyoxometalates have been stud- ied as oxidatively resistant analogues of metalloporphyrins.

Ronny Neumann; Alexander M. Khenkin

1998-01-01

325

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

326

40 CFR 721.10253 - Butanedioic acid, 2-methylene-, polymer with 2,5 furanedione, copper(2+) manganese(2+) sodium...  

Code of Federal Regulations, 2012 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...

2012-07-01

327

40 CFR 721.10253 - Butanedioic acid, 2-methylene-, polymer with 2,5 furanedione, copper(2+) manganese(2+) sodium...  

Code of Federal Regulations, 2014 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...

2014-07-01

328

Ultrahigh carbon steels, Damascus steels, and superplasticity  

SciTech Connect

The processing properties of ultrahigh carbon steels (UHCSs) have been studied at Stanford University over the past twenty years. These studies have shown that such steels (1 to 2.1% C) can be made superplastic at elevated temperature and can have remarkable mechanical properties at room temperature. It was the investigation of these UHCSs that eventually brought us to study the myths, magic, and metallurgy of ancient Damascus steels, which in fact, were also ultrahigh carbon steels. These steels were made in India as castings, known as wootz, possibly as far back as the time of Alexander the Great. The best swords are believed to have been forged in Persia from Indian wootz. This paper centers on recent work on superplastic UHCSs and on their relation to Damascus steels. 32 refs., 6 figs.

Sherby, O.D. [Stanford Univ., CA (United States). Dept. of Materials Science and Engineering; Wadsworth, J. [Lawrence Livermore National Lab., CA (United States)

1997-04-01

329

THE STATE OF MANGANESE IN THE PHOTOSYNTHETIC APPARATUS: FIRST VIEW OF THE MANGANESE SITES BY X-RAY ABSORPTION SPECTROSCOPY  

SciTech Connect

Manganese atoms have long been implicated as essential ingredients in photosynthetic oxygen evolution. Heretofore they have eluded direct observation. We report the first direct observation, by X-ray Absorption Spectroscopy, of the Mn sites in chloroplasts isolated from Spinacia oleracea. The manganese in chlorplasts is commonly thought to exist in two pools. The major pool, corresponding to two-thirds of the manganese, can be reversibly released with concomitant loss of oxygen evolving capacity, and has thus come to be assigned as the active pool. The role of the remanant one-third, or tightly bound pool is moot. Our analysis of the Extended X-ray Absorption Fine Structure of the active pool is consistent with a bridged dimeric structure involving two manganese atoms separated by about 2.7 {Angstroms}. The distance between manganese and bridging ligands is about 1.8 {Angstrom}. Analysis of the edge region suggests that the manganese in the active pool exists in oxidation states somewhat higher than Mn(II).

Kirby, Jon A.; Goodin, D.B.; Robertson, A.S.; Smith, J.P.; Thompson, A.C.; Klein, M.P.

1980-11-01

330

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

331

Effects of manganese deficiency and added cerium on nitrogen metabolism of maize.  

PubMed

Manganese is one of the essential microelements for plant growth, and cerium is a beneficial element for plant growth. However, whether manganese deficiency affects nitrogen metabolism of plants and cerium improves the nitrogen metabolism of plants by exposure to manganese-deficient media are still unclear. The main aim of the study was to determine the effects of manganese deficiency in nitrogen metabolism and the roles of cerium in the improvement of manganese-deficient effects in maize seedlings. Maize seedlings were cultivated in manganese present Meider's nutrient solution. They were subjected to manganese deficiency and to cerium chloride administered in the manganese-present and manganese-deficient media. Maize seedlings grown in the various media were measured for key enzyme activities involved in nitrogen metabolism, such as nitrate reductase, glutamate dehydrogenase, glutamine synthetase, and glutamic-oxaloace transaminase. We found that manganese deficiency restricted uptake and transport of NO(3)(-), inhibited activities of nitrogen-metabolism-related enzymes, such as nitrate reductase, glutamine synthetase, and glutamic-oxaloace transaminase, thus decreasing the synthesis of chlorophyll and soluble protein, and inhibited the growth of maize seedlings. Manganese deficiency promoted the activity of glutamate dehydrogenase and reduced the toxicity of excess ammonia to the plant, while added cerium relieved the damage to nitrogen metabolism caused by manganese deficiency in maize seedlings. However, cerium addition exerted positively to relieve the damage of nitrogen metabolism process in maize seedlings caused by exposure to manganese-deficient media. PMID:21660532

Gong, Xiaolan; Qu, Chunxiang; Liu, Chao; Hong, Mengmeng; Wang, Ling; Hong, Fashui

2011-12-01

332

Xenon in Mercury-Manganese Stars  

E-print Network

Previous studies of elemental abundances in Mercury-Manganese (HgMn) stars have occasionally reported the presence of lines of the ionized rare noble gas Xe II, especially in a few of the hottest stars with Teff ~ 13000--15000 K. A new study of this element has been undertaken using observations from Lick Observatory's Hamilton Echelle Spectrograph. In this work, the spectrum synthesis program UCLSYN has been used to undertake abundance analysis assuming LTE. We find that in the Smith & Dworetsky sample of HgMn stars, Xe is vastly over-abundant in 21 of 22 HgMn stars studied, by factors of 3.1--4.8 dex. There does not appear to be a significant correlation of Xe abundance with Teff. A comparison sample of normal late B stars shows no sign of Xe II lines that could be detected, consistent with the expected weakness of lines at normal abundance. The main reason for the previous lack of widespread detection in HgMn stars is probably due to the strongest lines being at longer wavelengths than the photographic...

Dworetsky, M M; Patel, K

2008-01-01

333

Mechanisms of lead and manganese neurotoxicity  

PubMed Central

Human exposure to neurotoxic metals is a global public health problem. Metals which cause neurological toxicity, such as lead (Pb) and manganese (Mn), are of particular concern due to the long-lasting and possibly irreversible nature of their effects. Pb exposure in childhood can result in cognitive and behavioural deficits in children. These effects are long-lasting and persist into adulthood even after Pb exposure has been reduced or eliminated. While Mn is an essential element of the human diet and serves many cellular functions in the human body, elevated Mn levels can result in a Parkinson's disease (PD)-like syndrome and developmental Mn exposure can adversely affect childhood neurological development. Due to the ubiquitous presence of both metals, reducing human exposure to toxic levels of Mn and Pb remains a world-wide public health challenge. In this review we summarize the toxicokinetics of Pb and Mn, describe their neurotoxic mechanisms, and discuss common themes in their neurotoxicity. PMID:25722848

Neal, April P.; Guilarte, Tomas R.

2015-01-01

334

Manganese Superoxide Dismutase: Guardian of the Powerhouse  

PubMed Central

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.

2011-01-01

335

Xenon in Mercury-Manganese Stars  

E-print Network

Previous studies of elemental abundances in Mercury-Manganese (HgMn) stars have occasionally reported the presence of lines of the ionized rare noble gas Xe II, especially in a few of the hottest stars with Teff ~ 13000--15000 K. A new study of this element has been undertaken using observations from Lick Observatory's Hamilton Echelle Spectrograph. In this work, the spectrum synthesis program UCLSYN has been used to undertake abundance analysis assuming LTE. We find that in the Smith & Dworetsky sample of HgMn stars, Xe is vastly over-abundant in 21 of 22 HgMn stars studied, by factors of 3.1--4.8 dex. There does not appear to be a significant correlation of Xe abundance with Teff. A comparison sample of normal late B stars shows no sign of Xe II lines that could be detected, consistent with the expected weakness of lines at normal abundance. The main reason for the previous lack of widespread detection in HgMn stars is probably due to the strongest lines being at longer wavelengths than the photographic blue. The lines used in this work were 4603.03A, 4844.33A and 5292.22A.

M. M. Dworetsky; J. L. Persaud; K. Patel

2008-01-16

336

Genetic factors and manganese-induced neurotoxicity  

PubMed Central

Manganese (Mn), is a trace metal required for normal physiological processes in humans. Mn levels are tightly regulated, as high levels of Mn result in accumulation in the brain and cause a neurological disease known as manganism. Manganism shares many similarities with Parkinsons disease (PD), both at the physiological level and the cellular level. Exposure to high Mn-containing environments increases the risk of developing manganism. Mn is absorbed primarily through the intestine and then released in the blood. Excessive Mn is secreted in the bile and excreted in feces. Mn enters and exits cells through a number of non-specific importers localized on the cell membrane. Mutations in one of the Mn exporters, SLC30A10 (solute carrier family 30, member 10), result in Mn induced toxicity with liver impairments and neurological dysfunction. Four PD genes have been identified in connection to regulation of Mn toxicity, shedding new light on potential links between manganism and PD. PMID:25136353

Chen, Pan; Parmalee, Nancy; Aschner, Michael

2014-01-01

337

Manganese alters rat brain amino acids levels  

PubMed Central

Manganese (Mn) is an essential element and it acts as a cofactor for a number of enzymatic reactions, including those involved in amino acid, lipid, protein and carbohydrate metabolism. Excessive exposure to Mn can lead to poisoning, characterized by psychiatric disturbances and an extrapyramidal disorder. Mn-induced neuronal degeneration is associated with alterations in amino acids metabolism. In the present study, we analyzed whole rat brain amino acid content subsequent to 4 or 8 intraperitoneal (ip) injections, with 25 mg MnCl2/kg/day, at 48-hour (h) intervals. We noted a significant increase in glycine brain levels after 4 or 8 Mn injections (p<0.05 and p<0.01, respectively) and arginine also after 4 or 8 injections (p<0.001). Significant increases were also noted in brain proline (p<0.01), cysteine (p<0.05), phenylalanine (p<0.01) and tyrosine (p<0.01) levels after 8 Mn injections vs. the control group. These findings suggest that Mn-induced alterations in amino acid levels secondary to Mn affect the neurochemical milieu. PMID:22971893

Santos, Dinamene; Batoreu, M. Camila; Almeida, Isabel; Ramos, Ruben; Sidoryk-Wegrzynowicz, M.; Aschner, Michael; Marreilha dos Santos, A.P.

2012-01-01

338

Redundancy among manganese peroxidases in Pleurotus ostreatus.  

PubMed

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). Mn(2+) amendment to P. ostreatus cultures results in enhanced degradation of recalcitrant compounds (such as the azo dye orange II) and lignin. In Mn(2+)-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 Mn(2+)-sufficient cultures, mnp3 was inactivated via the ?ku80 strain-based P. ostreatus gene-targeting system. In Mn(2+)-sufficient medium, inactivation of mnp3 did not significantly affect expression of nontargeted MnPs or their genes, nor did it considerably diminish the fungal Mn(2+)-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. PMID:23377936

Salame, Tomer M; Knop, Doriv; Levinson, Dana; Yarden, Oded; Hadar, Yitzhak

2013-04-01

339

Manganese accumulation in nail clippings as a biomarker of welding fume exposure and neurotoxicity.  

PubMed

Occupational exposure to welding fumes (WF) is thought to cause Parkinson's disease (PD)-like neurological dysfunction. An apprehension that WF may accelerate the onset of PD also exists. Identifying reliable biomarkers of exposure and neurotoxicity are therefore critical for biomonitoring and neurological risk characterization of WF exposure. Manganese (Mn) in welding consumables is considered the causative factor for the neurological deficits seen in welders. Hence, we sought to determine if Mn accumulation in blood or nail clippings can be a marker for adverse exposure and neurotoxicity. To model this, rats were exposed by intratracheal instillation to dissolved or suspended fume components collected from gas metal arc-mild steel (GMA-MS) or manual metal arc-hard surfacing (MMA-HS) welding. Trace element analysis revealed selective Mn accumulation in dopaminergic brain areas, striatum (STR) and midbrain (MB), following exposure to the two fumes. This caused dopaminergic abnormality as evidenced by loss of striatal tyrosine hydroxylase (Th; 25-32% decrease) and Parkinson disease (autosomal recessive, early onset) 7 (Park7; 25-46% decrease) proteins. While blood Mn was not detectable, Mn levels in nails strongly correlated with the pattern of Mn accumulation in the striatum (R(2)=0.9386) and midbrain (R(2)=0.9332). Exposure to manganese chloride (MnCl(2)) caused similar Mn accumulation in STR, MB and nail. Our findings suggest that nail Mn has the potential to be a sensitive and reliable biomarker for long-term Mn exposure and associated neurotoxicity. The non-invasive means by which nail clippings can be collected, stored, and transported with relative ease, make it an attractive surrogate for biomonitoring WF exposures in occupational settings. PMID:22085607

Sriram, Krishnan; Lin, Gary X; Jefferson, Amy M; Roberts, Jenny R; Andrews, Ronnee N; Kashon, Michael L; Antonini, James M

2012-01-27

340

Comminuting irradiated ferritic steel  

DOEpatents

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

341

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] [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] [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] [Univ. of Sydney, New South Wales (Australia). Electron Microscopy Unit

1998-10-09

342

Steel slag in acid mine drainage treatment and control  

SciTech Connect

Steel slags are composed of calcium alumino-silicate oxides. Most slags have a sandy texture, but others have a silty texture and give a fine, powdery feel. Neutralization potentials of steel slags range from 45 to 78%, which make them candidates for neutralizing the acidity in acid mine drainage. Analysis of total metal content in Mingo Junction steel slab shows high concentrations of aluminum, chromium, iron, manganese, and titanium. Upon leaching this slag with water, the leachate had a pH of 11.7 and n alkalinity of 1,450 mg/L as CaCO{sub 3} equivalent. In general, steel slag yielded more alkalinity than equal weights of limestone (500 to 1,500 mg/L compared to 60 to 80 mg/L) during leaching studies. Leaching the slag with water and a weak sulfuric acid solution showed that the metals contained in the slag were not readily leachable since these metals were found at low concentrations in the leachate. When different amounts of slag were mixed with an acid-producing coal refuse and then leached with water, pH values of the leachate varied between 3.5 and 7.3. Slightly elevated levels of selenium, nickel, manganese, and possibly iron were found in leachates of refuse/slag mixtures compared to refuse alone. Due to slag's high availability in some areas and low cost, steel slags show potential as an acid-neutralizing material for coal refuse and acid-producing spoils, and for treating acid mine drainage directly. If slag is to be used as an alkaline amendment, it must be added in sufficient quantities to ensure nonacid conditions now and in the future, since under acid conditions some metals may become available. Steel slag can also be used as a liming material for soils. The most promising use for steel slag is as a source of alkalinity to fresh waters that may subsequently encounter acid mine drainage, such as alkaline leach beds or limestone sand applications to headwater streams.

Ziemkiewicz, P.; Skousen, J.

1999-07-01

343

Selenium Induces Manganese-dependent Peroxidase Production by the White-Rot Fungus Bjerkandera adusta  

E-print Network

Selenium Induces Manganese-dependent Peroxidase Production by the White-Rot Fungus Bjerkandera, selenium (Se) induction of the ligninolytic enzyme manganese- dependent peroxidase (MnP) production-rot fungi. Keywords Lipid peroxidation . Manganese peroxidase . Selenium . White-rot fungi Abbreviations Ag

Tullos, Desiree

344

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

Code of Federal Regulations, 2010 CFR

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

2010-07-01

345

Manganese exposure from drinking water and children's academic achievement Khalid Khan a  

E-print Network

Manganese exposure from drinking water and children's academic achievement Khalid Khan a , Gail A Health, Department of Epidemiology, United States 1. Introduction Health effects of chronic manganese (Mn: Received 28 September 2011 Accepted 2 December 2011 Available online 13 December 2011 Keywords: Manganese

van Geen, Alexander

346

Manganese Detection with a Metal Catalyst Free Carbon Nanotube Electrode: Anodic versus Cathodic Stripping  

E-print Network

Manganese Detection with a Metal Catalyst Free Carbon Nanotube Electrode: Anodic versus Cathodic and sensitivity. The CSV method was used in pond water matrix addition measurements. Keywords: Manganese, Anodic.1002/elan.201200302 1 Introduction Manganese (Mn) is commonly found throughout most aquatic environments

Papautsky, Ian

347

40 CFR 721.10010 - Barium manganese oxide (BaMnO3).  

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false Barium manganese oxide (BaMnO3). 721.10010 Section...Chemical Substances 721.10010 Barium manganese oxide (BaMnO3). (a) Chemical...chemical substance identified as barium manganese oxide (BaMnO3 ) (PMN...

2011-07-01

348

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

349

Mesoporous Hydrous Manganese Dioxide Nanowall Arrays with Large Lithium Ion Energy Storage Capacities  

E-print Network

Mesoporous Hydrous Manganese Dioxide Nanowall Arrays with Large Lithium Ion Energy Storage of its low cost, low toxicity, and chemical stability.[3,4] However, the appli- cation of manganese relatively low intercalation capacity and poor cycle stability; bulk manganese diox- ide film could only

Cao, Guozhong

350

Multiple Scattering Calculations of Bonding and X-ray Absorption Spectroscopy of Manganese Oxides  

E-print Network

Multiple Scattering Calculations of Bonding and X-ray Absorption Spectroscopy of Manganese Oxides B edge X-ray absorption spectra of manganese oxides at the Mn L2,3, Mn K, and O K edges to investigate The particularly rich redox chemistry of manganese is evident in its oxides, which are of wide contemporary

Haskel, Daniel

351

40 CFR 721.10008 - Manganese strontium oxide (MnSrO3).  

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false Manganese strontium oxide (MnSrO3). 721...Chemical Substances 721.10008 Manganese strontium oxide (MnSrO3). (a...The chemical substance identified as manganese strontium oxide (MnSrO3 )...

2011-07-01

352

Lithium manganese oxide films fabricated by electron beam directed vapor deposition  

E-print Network

Lithium manganese oxide films fabricated by electron beam directed vapor deposition S. W. Jina 2007; published 17 December 2007 Lithium manganese oxide thin films have been grown using a gas jet of this material by sputtering and other vapor deposition techniques. The lithium manganese oxide films grown

Wadley, Haydn

353

Hydrous Manganese Dioxide Nanowall Arrays Growth and Their Ions Intercalation Electrochemical Properties  

E-print Network

Hydrous Manganese Dioxide Nanowall Arrays Growth and Their Li+ Ions Intercalation Electrochemical, 2007 Nanowall arrays of hydrous manganese dioxide MnO2 ·0.5H2O were deposited on cathodic substrates by the potentiostatic method from a mixed aqueous solution of manganese acetate and sodium sulfate, and the Li+ ions

Cao, Guozhong

354

Indirect Magnetic Coupling of Manganese Porphyrin to a Ferromagnetic Cobalt Substrate D. Chylarecka,  

E-print Network

Indirect Magnetic Coupling of Manganese Porphyrin to a Ferromagnetic Cobalt Substrate D. Chylarecka (DFT+U) calculations, for the magnetic coupling of manganese(II) porphyrin (MnP) molecules to thin Co and scanning tunneling microscopy (STM) study of manganese(III) tetraphenylporphyrin chloride (Mn

Aeschlimann, Martin

355

40 CFR 721.10008 - Manganese strontium oxide (MnSrO3).  

Code of Federal Regulations, 2014 CFR

...2014-07-01 2014-07-01 false Manganese strontium oxide (MnSrO3). 721...Chemical Substances 721.10008 Manganese strontium oxide (MnSrO3 ). ...The chemical substance identified as manganese strontium oxide (MnSrO3 )...

2014-07-01

356

Studies on the Manganese-Mediated Isomerization of Alkynyl Carbonyls to  

E-print Network

Studies on the Manganese-Mediated Isomerization of Alkynyl Carbonyls to Allenyl Carbonyls Salvatore@fau.edu Received May 24, 2005 A study of the role of base in the isomerization of manganese- coordinated conjugated indicates that manganese requires a ligand prior to isomerization with amine bases. A series of amine bases

Lepore, Salvatore D.

357

40 CFR 721.10010 - Barium manganese oxide (BaMnO3).  

Code of Federal Regulations, 2014 CFR

...2014-07-01 2014-07-01 false Barium manganese oxide (BaMnO3). 721.10010 Section...Chemical Substances 721.10010 Barium manganese oxide (BaMnO3 ). (a) Chemical...chemical substance identified as barium manganese oxide (BaMnO3 ) (PMN...

2014-07-01

358

Kinetics of manganese adsorption, desorption, and oxidation in coastal marine sediments  

E-print Network

Kinetics of manganese adsorption, desorption, and oxidation in coastal marine sediments Dominique´bec a` Rimouski, Que´bec, Canada Abstract Ejection of excavated manganese (Mn)-laden particles from disturbances triggers desorption and oxidation of reduced manganese species. These competing reactions

Beaudoin, Georges

359

Layer-Specific Manganese-Enhanced MRI of the Retina in Light and Dark Adaptation  

E-print Network

Retina Layer-Specific Manganese-Enhanced MRI of the Retina in Light and Dark Adaptation Bryan H. De manganese-enhanced MRI (MEMRI) to image layer-specific changes in calcium-dependent activities in the rat retina have also been demonstrated. Functional manganese-enhanced MRI (MEMRI)20,21 has also been used

Duong, Timothy Q.

360

Chin. Phys. B Vol. 20, No. 9 (2011) 096401 Self-assembly and growth of manganese  

E-print Network

Chin. Phys. B Vol. 20, No. 9 (2011) 096401 Self-assembly and growth of manganese phthalocyanine manuscript received 25 May 2011) Self-assembly and growth of manganese phthalocyanine (MnPc) molecules islands with second and third layers are observed. Keywords: self-assembly, manganese phthalocyanine

Gao, Hongjun

361

40 CFR 721.10010 - Barium manganese oxide (BaMnO3).  

Code of Federal Regulations, 2012 CFR

...2012-07-01 2012-07-01 false Barium manganese oxide (BaMnO3). 721.10010 Section...Chemical Substances 721.10010 Barium manganese oxide (BaMnO3 ). (a) Chemical...chemical substance identified as barium manganese oxide (BaMnO3 ) (PMN...

2012-07-01

362

Vesicular distribution of Secretory Pathway Ca2+ isoform 1 and a role in manganese detoxification  

E-print Network

Vesicular distribution of Secretory Pathway Ca2+ -ATPase isoform 1 and a role in manganese+Business Media, LLC. 2010 Abstract Manganese is a trace element that is an essential co-factor in many enzymes suggest a role for SPCA1 in Mn2? detoxification in liver. Keywords Manganese Á Ca2? -ATPase Á Liver Á

Rao, Rajini

363

Localization and Role of Manganese Superoxide Dismutase in a Marine Diatom1[OA  

E-print Network

Localization and Role of Manganese Superoxide Dismutase in a Marine Diatom1[OA] Felisa Wolfe-Simon2 by their metal cofactor (iron, manganese [Mn], copper/zinc, nickel), MnSOD is the dominant form in the diatom in four isoforms, recognized by their metal center cofactors (iron [Fe], manganese [Mn], copper [Cu

364

STRUCTURE AND REACTIVITY STUDY OF BIOTIC AND ABIOTIC POORLY CRYSTALLINE MANGANESE OXIDES  

E-print Network

STRUCTURE AND REACTIVITY STUDY OF BIOTIC AND ABIOTIC POORLY CRYSTALLINE MANGANESE OXIDES Rights Reserved #12;STRUCTURE AND REACTIVITY STUDY OF BIOTIC AND ABIOTIC POORLY CRYSTALLINE MANGANESE. Luther, III who inspired me on manganese reaction mechanisms in many helpful discussions, and Dr. Thomas

Sparks, Donald L.

365

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

Code of Federal Regulations, 2012 CFR

...2012-07-01 2012-07-01 false Lithium manganese oxide (LiMn204) (generic name...Chemical Substances 721.4587 Lithium manganese oxide (LiMn204) (generic name...substance identified generically as lithium manganese oxide (LiMn204)...

2012-07-01

366

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 Section...Chemical Substances 721.10010 Barium manganese oxide (BaMnO3). (a) Chemical...chemical substance identified as barium manganese oxide (BaMnO3 ) (PMN...

2010-07-01

367

3622 Organometallics 1992, 11,3622-3629 Catalytic Thermal C-H Activation with Manganese Complexes  

E-print Network

3622 Organometallics 1992, 11,3622-3629 Catalytic Thermal C-H Activation with Manganese Complexes: Evidence for q2-H2Coordination in a Neutral Manganese Complex and Its Role in C-H Activation Christophe- icallystudy and formulate a comprehensive view of C-H activation. It hasbeen reported that manganese complexes

Jones, William D.

368

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 Section...Chemical Substances 721.10010 Barium manganese oxide (BaMnO3 ). (a) Chemical...chemical substance identified as barium manganese oxide (BaMnO3 ) (PMN...

2013-07-01

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

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Lithium manganese oxide (LiMn204) (generic name...Chemical Substances 721.4587 Lithium manganese oxide (LiMn204) (generic name...substance identified generically as lithium manganese oxide (LiMn204)...

2013-07-01

370

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

Code of Federal Regulations, 2014 CFR

...2014-07-01 2014-07-01 false Lithium manganese oxide (LiMn204) (generic name...Chemical Substances 721.4587 Lithium manganese oxide (LiMn204) (generic name...substance identified generically as lithium manganese oxide (LiMn204)...

2014-07-01

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40 CFR 721.10008 - Manganese strontium oxide (MnSrO3).  

Code of Federal Regulations, 2012 CFR

...2012-07-01 2012-07-01 false Manganese strontium oxide (MnSrO3). 721...Chemical Substances 721.10008 Manganese strontium oxide (MnSrO3 ). ...The chemical substance identified as manganese strontium oxide (MnSrO3 )...

2012-07-01

372

Assessment of the role of manganese in congenital joint laxity and dwarfism in calves *  

E-print Network

Short note Assessment of the role of manganese in congenital joint laxity and dwarfism in calves. The congenital joint laxity and dwarfism was asso- ciated with a lower serum manganese concentration in silage-fed cows than in hay-fed cows. How- ever, manganese concentrations were similar in red clover silage, grass

Boyer, Edmond

373

Manganese porphyrin multilayer films assembled on ITO electrodes via zirconium phosphonate chemistry: chemical and electrochemical  

E-print Network

Manganese porphyrin multilayer films assembled on ITO electrodes via zirconium phosphonate University, 2145 Sheridan Road, Evanston, IL 60208-3113 A supported manganese porphyrin-based oxidation)porphyrinato] manganese(III) chloride (2) and zirconium(IV) ions on indium­tin oxide electrodes. This assembly technique

374

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

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false Lithium manganese oxide (LiMn204) (generic name...Chemical Substances 721.4587 Lithium manganese oxide (LiMn204) (generic name...substance identified generically as lithium manganese oxide (LiMn204)...

2011-07-01

375

Delta-phase manganese gallium on gallium nitride: a magnetically tunable spintronic system  

E-print Network

Delta-phase manganese gallium on gallium nitride: a magnetically tunable spintronic system Kangkang, University of Michigan, Ann Arbor, MI 48109, U.S.A. ABSTRACT Ferromagnetic delta-phase manganese gallium to their potential for novel spintronics applications such as spin light-emitting diodes[1] . Delta phase manganese

376

40 CFR 721.10009 - Manganese yttrium oxide (MnYO3).  

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false Manganese yttrium oxide (MnYO3). 721.10009 Section...Substances 721.10009 Manganese yttrium oxide (MnYO3). (a) Chemical substance...chemical substance identified as manganese yttrium oxide (MnYO3 ) (PMN...

2011-07-01

377

40 CFR 721.10013 - Manganese yttrium oxide (Mn2YO5).  

Code of Federal Regulations, 2014 CFR

...2014-07-01 2014-07-01 false Manganese yttrium oxide (Mn2YO5). 721.10013 Section...Substances 721.10013 Manganese yttrium oxide (Mn2 YO5 ). (a) Chemical...chemical substance identified as manganese yttrium oxide (Mn2 YO5 ) (PMN...

2014-07-01

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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 Section...Substances 721.10009 Manganese yttrium oxide (MnYO3 ). (a) Chemical...chemical substance identified as manganese yttrium oxide (MnYO3 ) (PMN...

2013-07-01

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40 CFR 721.10013 - Manganese yttrium oxide (Mn2YO5).  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Manganese yttrium oxide (Mn2YO5). 721.10013 Section...Substances 721.10013 Manganese yttrium oxide (Mn2YO5). (a) Chemical substance...chemical substance identified as manganese yttrium oxide (Mn2 YO5 ) (PMN...

2010-07-01

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40 CFR 721.10013 - Manganese yttrium oxide (Mn2YO5).  

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false Manganese yttrium oxide (Mn2YO5). 721.10013 Section...Substances 721.10013 Manganese yttrium oxide (Mn2YO5). (a) Chemical substance...chemical substance identified as manganese yttrium oxide (Mn2 YO5 ) (PMN...

2011-07-01

381

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 Section...Substances 721.10013 Manganese yttrium oxide (Mn2 YO5 ). (a) Chemical...chemical substance identified as manganese yttrium oxide (Mn2 YO5 ) (PMN...

2013-07-01

382

40 CFR 721.10009 - Manganese yttrium oxide (MnYO3).  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Manganese yttrium oxide (MnYO3). 721.10009 Section...Substances 721.10009 Manganese yttrium oxide (MnYO3). (a) Chemical substance...chemical substance identified as manganese yttrium oxide (MnYO3 ) (PMN...

2010-07-01

383

40 CFR 721.10009 - Manganese yttrium oxide (MnYO3).  

Code of Federal Regulations, 2014 CFR

...2014-07-01 2014-07-01 false Manganese yttrium oxide (MnYO3). 721.10009 Section...Substances 721.10009 Manganese yttrium oxide (MnYO3 ). (a) Chemical...chemical substance identified as manganese yttrium oxide (MnYO3 ) (PMN...

2014-07-01

384

40 CFR 721.10013 - Manganese yttrium oxide (Mn2YO5).  

Code of Federal Regulations, 2012 CFR

...2012-07-01 2012-07-01 false Manganese yttrium oxide (Mn2YO5). 721.10013 Section...Substances 721.10013 Manganese yttrium oxide (Mn2 YO5 ). (a) Chemical...chemical substance identified as manganese yttrium oxide (Mn2 YO5 ) (PMN...

2012-07-01

385

40 CFR 721.10009 - Manganese yttrium oxide (MnYO3).  

Code of Federal Regulations, 2012 CFR

...2012-07-01 2012-07-01 false Manganese yttrium oxide (MnYO3). 721.10009 Section...Substances 721.10009 Manganese yttrium oxide (MnYO3 ). (a) Chemical...chemical substance identified as manganese yttrium oxide (MnYO3 ) (PMN...

2012-07-01

386

75 FR 70583 - Cobalt Lithium Manganese Nickel Oxide; Withdrawal of Significant New Use Rule  

Federal Register 2010, 2011, 2012, 2013, 2014

...EPA-HQ-OPPT-2009-0922; FRL-8853-2] RIN 2070-AB27 Cobalt Lithium Manganese Nickel Oxide; Withdrawal...for the chemical substance identified as cobalt lithium manganese nickel oxide (CAS No...EPA is withdrawing the rule issued for cobalt lithium manganese nickel oxide (PMN...

2010-11-18

387

76 FR 47996 - Cobalt Lithium Manganese Nickel Oxide; Significant New Use Rule  

Federal Register 2010, 2011, 2012, 2013, 2014

...EPA-HQ-OPPT-2009-0922; FRL-8878-2] RIN 2070-AB27 Cobalt Lithium Manganese Nickel Oxide; Significant...for the chemical substance identified as cobalt lithium manganese nickel oxide (CAS No...for the chemical substance identified as cobalt lithium manganese nickel oxide...

2011-08-08

388

Olfactory uptake of manganese requires DMT1 and is enhanced by anemia  

Microsoft Academic Search

Manganese, an essential nutrient, can also elicit toxicity in the central nervous system (CNS). The route of exposure strongly influences the potential neurotoxicity of manganese-containing compounds. Recent studies suggest that inhaled manganese can enter the rat brain through the olfactory system, but little is known about the molecular factors involved. Divalent metal transporter-1 (DMT1) is the major trans- porter responsible

Khristy Thompson; Ramon M. Molina; Thomas Donaghey; James E. Schwob; Joseph D. Brain; Marianne Wessling-Resnick

2006-01-01

389

40 CFR 721.10008 - Manganese strontium oxide (MnSrO3).  

Code of Federal Regulations, 2010 CFR

... 2010-07-01 false Manganese strontium oxide (MnSrO3). 721.10008 Section...Substances 721.10008 Manganese strontium oxide (MnSrO3). (a) Chemical...chemical substance identified as manganese strontium oxide (MnSrO3 ) (PMN...

2010-07-01

390

High manganese concentrations in rocks at Gale crater, Mars  

NASA Astrophysics Data System (ADS)

The surface of Mars has long been considered a relatively oxidizing environment, an idea supported by the abundance of ferric iron phases observed there. However, compared to iron, manganese is sensitive only to high redox potential oxidants, and when concentrated in rocks, it provides a more specific redox indicator of aqueous environments. Observations from the ChemCam instrument on the Curiosity rover indicate abundances of manganese in and on some rock targets that are 1-2 orders of magnitude higher than previously observed on Mars, suggesting the presence of an as-yet unidentified manganese-rich phase. These results show that the Martian surface has at some point in time hosted much more highly oxidizing conditions than has previously been recognized.

Lanza, Nina L.; Fischer, Woodward W.; Wiens, Roger C.; Grotzinger, John; Ollila, Ann M.; Cousin, Agnes; Anderson, Ryan B.; Clark, Benton C.; Gellert, Ralf; Mangold, Nicolas; Maurice, Sylvestre; Le Moulic, Stphane; Nachon, Marion; Schmidt, Mariek; Berger, Jeffrey; Clegg, Samuel M.; Forni, Olivier; Hardgrove, Craig; Melikechi, Noureddine; Newsom, Horton E.; Sautter, Violaine

2014-08-01

391

Manganese- and iron-dependent marine methane oxidation.  

PubMed

Anaerobic methanotrophs help regulate Earth's climate and may have been an important part of the microbial ecosystem on the early Earth. The anaerobic oxidation of methane (AOM) is often thought of as a sulfate-dependent process, despite the fact that other electron acceptors are more energetically favorable. Here, we show that microorganisms from marine methane-seep sediment in the Eel River Basin in California are capable of using manganese (birnessite) and iron (ferrihydrite) to oxidize methane, revealing that marine AOM is coupled, either directly or indirectly, to a larger variety of oxidants than previously thought. Large amounts of manganese and iron are provided to oceans from rivers, indicating that manganese- and iron-dependent AOM have the potential to be globally important. PMID:19589998

Beal, Emily J; House, Christopher H; Orphan, Victoria J

2009-07-10

392

Manganese- and Iron-Dependent Marine Methane Oxidation  

NASA Astrophysics Data System (ADS)

Anaerobic methanotrophs help regulate Earths climate and may have been an important part of the microbial ecosystem on the early Earth. The anaerobic oxidation of methane (AOM) is often thought of as a sulfate-dependent process, despite the fact that other electron acceptors are more energetically favorable. Here, we show that microorganisms from marine methane-seep sediment in the Eel River Basin in California are capable of using manganese (birnessite) and iron (ferrihydrite) to oxidize methane, revealing that marine AOM is coupled, either directly or indirectly, to a larger variety of oxidants than previously thought. Large amounts of manganese and iron are provided to oceans from rivers, indicating that manganese- and iron-dependent AOM have the potential to be globally important.

Beal, Emily J.; House, Christopher H.; Orphan, Victoria J.

2009-07-01

393

Manganese?oxidizing bacteria mediate the degradation of 17??ethinylestradiol  

PubMed Central

Summary Manganese (II) and manganese?oxidizing bacteria were used as an efficient biological system for the degradation of the xenoestrogen 17??ethinylestradiol (EE2) at trace concentrations. Mn2+?derived higher oxidation states of Mn (Mn3+, Mn4+) by Mn2+?oxidizing bacteria mediate the oxidative cleavage of the polycyclic target compound EE2. The presence of manganese (II) was found to be essential for the degradation of EE2 by Leptothrix discophora, Pseudomonas putida MB1, P.?putida MB6 and P.?putida MB29. Mn2+?dependent degradation of EE2 was found to be a slow process, which requires multi?fold excess of Mn2+ and occurs in the late stationary phase of growth, implying a chemical process taking place. EE2?derived degradation products were shown to no longer exhibit undesirable estrogenic activity. PMID:21261871

Sabirova, Julia S.; Cloetens, L. F. F.; Vanhaecke, L.; Forrez, I.; Verstraete, Willy; Boon, N.

2008-01-01

394

Manganese superoxide dismutase: beyond life and death.  

PubMed

Manganese superoxide dismutase (MnSOD) is a nuclear-encoded antioxidant enzyme that localizes to the mitochondria. Expression of MnSOD is essential for the survival of aerobic life. Transgenic mice expressing a luciferase reporter gene under the control of the human MnSOD promoter demonstrate that the level of MnSOD is reduced prior to the formation of cancer. Overexpression of MnSOD in transgenic mice reduces the incidences and multiplicity of papillomas in a DMBA/TPA skin carcinogenesis model. However, MnSOD deficiency does not lead to enhanced tumorigenicity of skin tissue similarly treated because MnSOD can modulate both the p53-mediated apoptosis and AP-1-mediated cell proliferation pathways. Apoptosis is associated with an increase in mitochondrial levels of p53 suggesting a link between MnSOD deficiency and mitochondrial-mediated apoptosis. Activation of p53 is preventable by application of a SOD mimetic (MnTE-2-PyP(5+)). Thus, p53 translocation to mitochondria and subsequent inactivation of MnSOD explain the observed mitochondrial dysfunction that leads to transcription-dependent mechanisms of p53-induced apoptosis. Administration of MnTE-2-PyP(5+) following apoptosis but prior to proliferation leads to suppression of protein carbonyls and reduces the activity of AP-1 and the level of the proliferating cellular nuclear antigen, without reducing the activity of p53 or DNA fragmentation following TPA treatment. Remarkably, the incidence and multiplicity of skin tumors are drastically reduced in mice that receive MnTE-2-PyP(5+) prior to cell proliferation. The results demonstrate the role of MnSOD beyond its essential role for survival and suggest a novel strategy for an antioxidant approach to cancer intervention. PMID:20454814

Holley, Aaron K; Dhar, Sanjit Kumar; Xu, Yong; St Clair, Daret K

2012-01-01

395

Biological Superoxide In Manganese Oxide Formation  

NASA Astrophysics Data System (ADS)

Manganese (Mn) oxides are among the strongest sorbents and oxidants within the environment, controlling the fate and transport of numerous elements and the degradation of recalcitrant carbon. Both bacteria and fungi mediate the oxidation of Mn(II) to Mn(III/IV) oxides but the genetic and biochemical mechanisms responsible remain poorly understood. Furthermore, the physiological basis for microbial Mn(II) oxidation remains an enigma. We have recently reported that a common marine bacterium (Roseobacter sp. AzwK-3b) oxidizes Mn(II) via reaction with extracellular superoxide (O2-) produced during exponential growth. Here we expand this superoxide-mediated Mn(II) oxidation pathway to fungi, introducing a surprising homology between prokaryotic and eukaryotic metal redox processes. For instance, Stibella aciculosa, a common soil Ascomycete filamentous fungus, precipitates Mn oxides at the base of asexual reproductive structures (synnemata) used to support conidia (Figure 1). This distribution is a consequence of localized production of superoxide (and it's dismutation product hydrogen peroxide, H2O2), leading to abiotic oxidation of Mn(II) by superoxide. Disruption of NADPH oxidase activity using the oxidoreductase inhibitor DPI leads to diminished cell differentiation and subsequent Mn(II) oxidation inhibition. Addition of Cu(II) (an effective superoxide scavenger) leads to a concentration dependent decrease in Mn oxide formation. We predict that due to the widespread production of extracellular superoxide within the fungal and likely bacterial kingdoms, biological superoxide may be an important contributor to the cycling of Mn, as well as other metals (e.g., Hg, Fe). Current and future explorations of the genes and proteins involved in superoxide production and Mn(II) oxidation will ideally lend insight into the physiological and biochemical basis for these processes.

Hansel, C.; Learman, D.; Zeiner, C.; Santelli, C. M.

2011-12-01

396

Manganese Transport via the Transferrin Mechanism  

PubMed Central

Excessive manganese (Mn) uptake by brain cells, particularly in regions like the basal ganglia, can lead to toxicity. Mn2+ is transported into cells via a number of mechanisms, while Mn3+ is believed to be transported similarly to iron (Fe) via the transferrin (Tf) mechanism. Cellular Mn uptake is therefore determined by the activity of the mechanisms transporting Mn into each type of cell and by the amounts of Mn2+, Mn3+ and their complexes to which these cells are exposed; this complicates understanding the contributions of each transporter to Mn toxicity. While uptake of Fe3+ via the Tf mechanism is well understood, uptake of Mn3+ via this mechanism has not been systematically studied. The stability of the Mn3+Tf complex allowed us to form and purify this complex and label it with a fluorescent (Alexa green) tag. Using purified and labeled Mn3+Tf and biophysical tools, we have developed a novel approach to study Mn3+Tf transport independently of other Mn transport mechanisms. This approach was used to compare the uptake of Mn3+Tf into neuronal cell lines with published descriptions of Fe3+ uptake via the Tf mechanism, and to obtain quantitative information on Mn uptake via the Tf mechanism. Results confirm that in these cell lines significant Mn3+ is transported by the Tf mechanism similarly to Fe3+Tf transport; although Mn3+Tf transport is markedly slower than other Mn transport mechanisms. This novel approach may prove useful for studying Mn toxicity in other systems and cell types. PMID:23146871

Gunter, Thomas E.; Gerstner, Brent; Gunter, Karlene K.; Malecki, Jon; Gelein, Robert; Valentine, William M.; Aschner, Michael; Yule, David I.

2013-01-01

397

Manganese superoxide dismutase: beyond life and death  

PubMed Central

Manganese superoxide dismutase (MnSOD) is a nuclear-encoded antioxidant enzyme that localizes to the mitochondria. Expression of MnSOD is essential for the survival of aerobic life. Transgenic mice expressing a luciferase reporter gene under the control of the human MnSOD promoter demonstrate that the level of MnSOD is reduced prior to the formation of cancer. Overexpression of MnSOD in transgenic mice reduces the incidences and multiplicity of papillomas in a DMBA/TPA skin carcinogenesis model. However, MnSOD deficiency does not lead to enhanced tumorigenicity of skin tissue similarly treated because MnSOD can modulate both the p53-mediated apoptosis and AP-1-mediated cell proliferation pathways. Apoptosis is associated with an increase in mitochondrial levels of p53 suggesting a link between MnSOD deficiency and mitochondrial-mediated apoptosis. Activation of p53 is preventable by application of a SOD mimetic (MnTE-2-PyP5+). Thus, p53 translocation to mitochondria and subsequent inactivation of MnSOD explain the observed mitochondrial dysfunction that leads to transcription-dependent mechanisms of p53-induced apoptosis. Administration of MnTE-2-PyP5+ following apoptosis but prior to proliferation leads to suppression of protein carbonyls and reduces the activity of AP-1 and the level of the proliferating cellular nuclear antigen, without reducing the activity of p53 or DNA fragmentation following TPA treatment. Remarkably, the incidence and multiplicity of skin tumors are drastically reduced in mice that receive MnTE-2-PyP5+ prior to cell proliferation. The results demonstrate the role of MnSOD beyond its essential role for survival and suggest a novel strategy for an antioxidant approach to cancer intervention. PMID:20454814

Holley, Aaron K.; Dhar, Sanjit Kumar; Xu, Yong

2010-01-01

398

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

399

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

400

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; Mller, Daniel B; Allwood, Julian M

2013-04-01

401

Manganese oxidation state mediates toxicity in PC12 cells  

SciTech Connect

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 {mu}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, serotonin, H-ferritin, transferrin receptor (TfR), Mn-superoxide dismutase (MnSOD), and copper-zinc superoxide dismutase (CuZnSOD) protein levels). Exposures to Mn(III) >10 {mu}M produced 2- to 5-fold higher cellular manganese levels than equimolar exposures to Mn(II). Cell viability and ATP levels both decreased at the highest Mn(II) and Mn(III) exposures (150-200 {mu}M), while Mn(III) exposures produced increases in LDH activity at lower exposures ({>=}50 {mu}M) than did Mn(II) (200 {mu}M only). Mn(II) reduced cellular dopamine levels more than Mn(III), especially at the highest exposures (50% reduced at 200 {mu}M Mn(II)). In contrast, Mn(III) produced a >70% reduction in cellular serotonin at all exposures compared to Mn(II). Different cellular responses to Mn(II) exposures compared to Mn(III) were also observed for H-ferritin, TfR, and MnSOD protein levels. Notably, these differential effects of Mn(II) versus Mn(III) exposures on cellular toxicity could not simply be accounted for by the different cellular levels of manganese. These results suggest that the oxidation state of manganese exposures plays an important role in mediating manganese cytotoxicity.

Reaney, S.H. [Department of Chemistry and Biochemistry, University of California, Santa Cruz, CA 95064 (United States) and Department of Environmental Toxicology, University of California, 1156 High St., Santa Cruz, CA 95064 (United States)]. E-mail: stevereaney@hotmail.com; Smith, D.R. [Department of Environmental Toxicology, University of California, 1156 High St., Santa Cruz, CA 95064 (United States)

2005-06-15

402

The sensitized luminescence of manganese-activated calcite  

USGS Publications Warehouse

Synthetic manganese-activated calcites are shown to be practically inert to ultraviolet excitation in the range 2000-3500A, while they are luminescent under cathode-ray excitation. The incorporation of small amounts of an auxiliary impurity along with the manganese produces the strong response to ultraviolet radiation hitherto ascribed to CaCO3:Mn itself. Three such impurities have been studied: lead, thallium, and cerium. The first two induce excitation in the neighborhood of the mercury resonance line, while the cerium introduces a response principally to longer wave ultraviolet. The strong response to 2537A excitation shown by some natural calcites is likewise found to be due to the presence of lead along with the manganese, rather than to the manganese alone. The data do not warrant ascribing the longer wave-length ultraviolet-excited luminescence of all natural calcites to the action of an auxiliary impurity. The essential identity of the cathode-ray excited luminescence spectra of CaCO 3:Mn, CaCO3: (Pb+Mn), CaCO3:(Tl+Mn), and CaCO3:(Ce+Mn) with the 2537A-excited spectra of the latter three is evidence that the luminescent center in all cases is the manganese ion or the MnO6 group. It is shown that a "cascade" mechanism for the action of the auxiliary impurities, lead, thallium, and cerium, is incorrect; and that the phenomenon must be considered as a case of sensitized luminescence. Owing to the nature of cathode-ray excitation, the manganese activator can be excited by this agent even in the absence of a second impurity. For optical excitation, however, an absorption band for the ultraviolet must be established by building into the CaCO3:Mn a second impurity or "sensitizer.".

Schulman, J.H.; Evans, L.W.; Ginther, R.J.; Murata, K.J.

1947-01-01

403

Effects of heat treatment and alloying elements on the microstructures and mechanical properties of 0.15 wt pct C transformation-induced plasticity-aided cold-rolled steel sheets  

Microsoft Academic Search

The main emphasis of this study has been placed on understanding the effects of manganese and silicon additions and of heat-treatment\\u000a (intercritical annealing and isothermal treatment) conditions on the microstructures and mechanical properties of 0.15 wt\\u000a pct C transformation-induced plasticity (TRIP)-aided cold-rolled steel sheets. The steel sheets were intercritically annealed\\u000a and isothermally treated at the bainitic region. Microstructural observation and

Sung-Joon Kim; Chang Gjl Lee; Ildong Choi; Sunghak Lee

2001-01-01

404

Methods of forming steel  

DOEpatents

In one aspect, the invention encompasses a method of forming a steel. A metallic glass is formed and at least a portion of the glass is converted to a crystalline steel material having a nanocrystalline scale grain size. In another aspect, the invention encompasses another method of forming a steel. A molten alloy is formed and cooled the alloy at a rate which forms a metallic glass. The metallic glass is devitrified to convert the glass to a crystalline steel material having a nanocrystalline scale grain size. In yet another aspect, the invention encompasses another method of forming a steel. A first metallic glass steel substrate is provided, and a molten alloy is formed over the first metallic glass steel substrate to heat and devitrify at least some of the underlying metallic glass of the substrate.

Branagan, Daniel J. (Iona, ID); Burch, Joseph V. (Shelley, ID)

2001-01-01

405

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

406

MAGNETIC INTERACTION BETWEEN TWO NON-MAGNETIC PARTICLES MIGRATING IN A CONDUCTIVE FLUID INDUCED BY A STRONG MAGNETIC FIELD-AN ANALYTICAL APPROACH  

Microsoft Academic Search

An analytical approach is developed in the present paper to investigate the interaction between two non-magnetic particles migrating in a conductive ?uid due to an imposed strong magnetic fleld (e.g., 10 Tesla). The interaction between the conductive ?uid and a single particle migrating along the magnetic lines is in?uenced by the magnetic fleld and can be represented by an additional

Zhi Sun; Muxing Guo; Frederik Verhaeghe; Jef Vleugels; Omer Van der Biest; Bart Blanpain

2010-01-01

407

Characterization of High-Velocity Solution Precursor Flame-Sprayed Manganese Cobalt Oxide Spinel Coatings for Metallic SOFC Interconnectors  

NASA Astrophysics Data System (ADS)

A modified high-velocity oxy-fuel spray (HVOF) thermal spray torch equipped with liquid feeding hardware was used to spray manganese-cobalt solutions on ferritic stainless steel grade Crofer 22 APU substrates. The HVOF torch was modified in such a way that the solution could be fed axially into the combustion chamber through 250- and 300-?m-diameter liquid injector nozzles. The solution used in this study was prepared by diluting nitrates of manganese and cobalt, i.e., Mn(NO3)24H2O and Co(NO3)26H2O, respectively, in deionized water. The as-sprayed coatings were characterized by X-ray diffraction and field-emission scanning electron microscopy operating in secondary electron mode. Chemical analyses were performed on an energy dispersive spectrometer. Coatings with remarkable density could be prepared by the novel high-velocity solution precursor flame spray (HVSPFS) process. Due to finely sized droplet formation in the HVSPFS process and the use of as delivered Crofer 22 APU substrate material having very low substrate roughness ( R a < 0.5 ?m), thin and homogeneous coatings, with thicknesses lower than 10 ?m could be prepared. The coatings were found to have a crystalline structure equivalent to MnCo2O4 spinel with addition of Co-oxide phases. Crystallographic structure was restored back to single-phase spinel structure by heat treatment.

Puranen, Jouni; Laakso, Jarmo; Kylmlahti, Mikko; Vuoristo, Petri

2013-06-01

408

Transuranic interfacial reaction studies on manganese oxidemineral surfaces  

SciTech Connect

Several DOE sites have been contaminated by transuranicradionuclide (TRU) discharges including neptunium and plutonium. Theirinteraction with the surrounding geological media can affect thetransport and remediation of these radionuclides in the environment.Manganese based minerals, present as minor phases in the vadose zone, canpreferentially sequester TRU over other minerals present in largerquantities. The objective of this project is to understand theinteractions between plutonium and neptunium and manganese oxyhydroxideminerals to predict potential hazards they represent to the environment,as well as to provide important scientific information for the design ofeffective remediation strategies for contaminated DOE sites.

Shaughnessy, Dawn A.; Nitsche, Heino; Serne, R. Jeffrey; Shuh,David K.; Waychunas, Glenn A.; Booth, Corwin H.; Cantrell, Kirk J.

2002-05-15

409

Biochemical changes in pulmonary cells following manganese oxide inhalation  

SciTech Connect

Inhalation of manganese oxide (Mn dose, 879.0 ..mu..g/m/sup 3/) for 2 h reduced the total number of alveolar macrophages obtained by endotracheal lavage in pulmonary cell populations, slightly reduced cellular viability, and reduced both phagocytic capability and total protein in sonicated pulmonary cells. Increases in intracellular adenosine triphosphate and acid phosphatase specific activity were also exhibited by the pulmonary cells, but sonicated cells obtained from the exposed mice showed no change in lactic acid dehydrogenase specific activity. A slight increase in extracellular protein in the fluid phase of the lavage suspension was observed after manganese oxide exposure.

Adkins, B. Jr. (Northrop Services, Inc., Research Triangle Park, NC); Luginbuhl, G.H.; Gardner, D.E.

1980-03-01

410

Effect of Internal Hydrogen on Delayed Cracking of Metastable Low-Nickel Austenitic Stainless Steels  

NASA Astrophysics Data System (ADS)

Metastable austenitic stainless steels, especially manganese-alloyed low-nickel grades, may be susceptible to delayed cracking after forming processes. Even a few wppm of hydrogen present in austenitic stainless steels as an inevitable impurity is sufficient to cause cracking if high enough fraction of strain-induced ?'-martensite and high residual tensile stresses are present. The role of internal hydrogen content in delayed cracking of several metastable austenitic stainless steels having different alloying chemistries was investigated by means of Swift cup tests, both in as-supplied state and after annealing at 673 K (400 C). Hydrogen content of the test materials in each state was analyzed with three different methods: inert gas fusion, thermal analysis, and thermal desorption spectroscopy. Internal hydrogen content in as-supplied state was higher in the studied manganese-alloyed low-nickel grades, which contributed to susceptibility of unstable grades to delayed cracking. Annealing of the stainless steels reduced their hydrogen content by 1 to 3 wppm and markedly lowered the risk of delayed cracking. Limiting drawing ratio was improved from 1.4 to 1.7 in grade 204Cu, from 1.7 to 2.0 in grade 201 and from 1.8 to 2.12 in grade 301. The threshold levels of ?'-martensite and residual stress for delayed cracking at different hydrogen contents were defined for the test materials.

Papula, Suvi; Talonen, Juho; Todoshchenko, Olga; Hnninen, Hannu

2014-10-01

411

The effect of manganese-copper interactions on growth of a diatom in water from a manganese-rich British Columbia fjord  

NASA Astrophysics Data System (ADS)

A competitive interaction between manganese and copper has previously been reported for the growth of marine phytoplankton. This was confirmed in an artificial medium with the marine diatom Thalassiosira pseudonana. The reduction in cell division rate produced by excess copper was alleviated by increasing the concentration of manganese. This relationship was also found to exist in natural water from a silled British Columbia fjord; the reduction in cell division rate with added copper was less in manganese-rich deep water than in manganese-poor shallow water. In coastal waters, elevated concentrations of manganese occur under certain hydrographic conditions and have the potential to reduce the detrimental effects of excess biologically available copper. At lower levels of copper, high concentrations of manganese may reduce uptake and produce a copper deficiency.

Kazumi, Junko; Zorkin, Nicholas; Lewis, A. G.

1987-09-01

412

Manganese sulfide formation via concomitant microbial manganese oxide and thiosulfate reduction  

SciTech Connect

The dissimilatory metal-reducing bacterium, Shewanella oneidensis MR-1 produced {gamma}-MnS (rambergite) nanoparticles during the concurrent reduction of MnO{sub 2} and thiosulfate coupled to H{sub 2} oxidation. To investigate effect of direct microbial reduction of MnO{sub 2} on MnS formation, two MR-1 mutants defective in outer membrane c-type cytochromes ({Delta}mtrC/{Delta}omcA and {Delta}mtrC/{Delta}omcA/{Delta}mtrF) were also used and it was determined that direct reduction of MnO{sub 2} 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{sub 3} (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{sub 3} 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 favor 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 modeling 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.

Lee, Ji-Hoon; Kennedy, David W.; Dohnalkova, Alice; Moore, Dean A.; Nachimuthu, Ponnusamy; Reed, Samantha B.; Fredrickson, Jim K.

2011-12-13

413

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

414

Iron and manganese are two similar ele-ments that can be a nuisance in a drinking  

E-print Network

Iron and manganese are two similar ele- ments that can be a nuisance in a drinking water supply. Iron is more common than manganese, but they often occur together. They are not hazardous to health. What problems do iron and manganese cause? Iron and manganese can give water an unpleasant taste, odor

415

Comparative response of poppy (Papaver somniferum L.) and eight crop and vegetable species to manganese excess in solution culture  

Microsoft Academic Search

The relative response of poppy (Papaver somniferum L.) and eight crop and vegetable species to excess manganese was investigated in a glasshouse, solution culture experiment. Plant yields and manganese concentrations were measured after two and six weeks growth at five levels of manganese (10800 ?M). Poppies were highly sensitive to manganese toxicity in solution culture and reductions in shoot yield

T. B. Koen

1982-01-01

416

Observation of ferromagnetic semiconductor behavior in manganese-oxide doped graphene  

NASA Astrophysics Data System (ADS)

We have doped manganese-oxide onto graphene by an electrochemical method. Graphene showed a clear ferromagnetic semiconductor behavior after doping of manganese-oxide. The manganese-oxide doped graphene has a coercive field (Hc) of 232 Oe at 10 K, and has the Curie temperature of 270 K from the temperature-dependent resistivity using transport measurement system. The ferromagnetism of manganese-oxide doped graphene attributes to the double-exchange from the coexistence of Mn3+ and Mn4+ on the surface of graphene. In addition, the semiconducting behavior is caused by the formation of manganese-oxide on graphene.

Park, Chang-Soo; Zhao, Yu; Shon, Yoon; Yoon, Chong S.; Lee, Haigun; Lee, Cheol Jin

2014-08-01

417

Steel: Steel Reheating for Further Processing  

SciTech Connect

Oxy-fuel combustion burners have the potential to reduce energy consumption by as much as 45% per ton of steel. Order this fact sheet and read about the many other benefits of this exciting new process.

Ericksen, E.

1999-01-29

418

Active transport at the blood-CSF barrier contributes to manganese influx into the brain.  

PubMed

Manganese is an essential trace element, and a contrast agent of potential interest for brain magnetic resonance imaging. Brain overexposure to manganese, however induces a neurodegenerative syndrome. Imaging data suggest that manganese appearance into the CSF precedes its accumulation into the cerebral parenchyma. We therefore investigated manganese uptake and transport at the blood-CSF barrier. Like lead, the non protein-bound divalent manganese accumulated into the rat choroid plexus. The metal accumulation was especially high in developing animals. Using a differentiated cellular model of the blood-CSF barrier, we demonstrated that manganese crosses the choroid plexus epithelium by a concentrating, unidirectional blood-to-CSF transport mechanism. This transport was inhibited by calcium, which is also transported into the CSF against its concentration gradient. The permeability barrier function towards lipid-insoluble compound and the organic anion transport property of the blood-brain interface were affected by exposure of the blood-facing membrane of choroidal cells to micromolar concentrations of manganese, but its antioxidant capacity was not. The unidirectional transport of manganese across the choroid plexus provides the anatomo-functional basis linking the systemic exposure to manganese with the spreading pattern of manganese accumulation observed in brain imaging, and explains the polarized sensitivity of choroidal epithelial cells to manganese toxicity. PMID:21395586

Schmitt, Charlotte; Strazielle, Nathalie; Richaud, Pierre; Bouron, Alexandre; Ghersi-Egea, Jean-Franois

2011-05-01

419

Time to Re-evaluate the Guideline Value for Manganese in Drinking Water?  

PubMed Central

Objective We reviewed the scientific background for the current health-based World Health Organization (WHO) guideline value for manganese in drinking water. Data sources and extraction The initial starting point was the background document for the development of the WHOs guideline value for manganese in drinking water as well as other regulations and recommendations on manganese intake levels. Data referred to in these documents were traced back to the original research papers. In addition, we searched for scientific reports on manganese exposure and health effects. Data synthesis The current health-based guideline value for manganese in drinking water is based partly on debatable assumptions, where information from previous reports has been used without revisiting original scientific articles. Presently, preparation of common infant formulas with water containing manganese concentrations equivalent to the WHO guideline value will result in exceeding the maximum manganese concentration for infant formula. However, there are uncertainties about how this maximum value was derived. Concurrently, there is increasing evidence of negative neurologic effects in children from excessive manganese exposure. Conclusions The increasing number of studies reporting associations between neurologic symptoms and manganese exposure in infants and children, in combination with the questionable scientific background data used in setting the manganese guideline value for drinking water, certainly warrant a re-evaluation of the guideline value. Further research is needed to understand the causal relationship between manganese exposure and childrens health, and to enable an improved risk assessment. PMID:18007980

Ljung, Karin; Vahter, Marie

2007-01-01

420

Manganese-oxidizing photosynthesis before the rise of cyanobacteria  

E-print Network

Manganese-oxidizing photosynthesis before the rise of cyanobacteria Jena E. Johnsona,1 , Samuel M) The emergence of oxygen-producing (oxygenic) photosynthesis fundamentally transformed our planet; however biological innovation-- the evolution of oxygenic photosynthesis (3, 4). Several bio- chemical attributes

Fischer, Woodward

421

Elements of the iron and manganese cycles in Lake Baikal  

USGS Publications Warehouse

Using data obtained in recent years, we considered the external mass balance and characteristics of internal iron and manganese cycles in Lake Baikal (biological uptake, remineralization, sedimentary and diffusive fluxes, accumulation in sediments, time of renewal, etc.). Some previous results and common concepts were critically reevaluated. ?? Pleiades Publishing, Ltd. 2007.

Granina, L.Z.; Callender, E.

2007-01-01

422

EFFECTS OF MANGANESE AND THEIR MODIFICATION BY HEXAMETAPHOSPHATE  

EPA Science Inventory

The ability of oral Mn(+2) to produce the depletions of dopamine in the corpus striata characteristic of the Parkinson-like syndrome in manganese workers was examined in rats. A second objective of this work was to study the biological interactions between Mn(+2) and sodium hexam...

423

Community Exposure to Air Manganese and Motor and Cognitive Outcomes  

EPA Science Inventory

Although manganese (Mn) is an essential nutrient, occupational studies have shown inhaling high levels of Mn can lead to adverse nervous system health effects. Few studies have examined the health effects of air-Mn exposure on adults in a community. We conducted a cross-sectional...

424

Cognitive Function Related to Environmental Exposure to Manganese  

EPA Science Inventory

Background: The towns of Marietta and East Liverpool (EL), Ohio, have been identified as having elevated manganese (Mn) in air due to industrial pollution. Objectives: To evaluate relationships between environmental Mn (Mn-air) exposure and distance from the source and cognitive...

425

Differential tolerance of high manganese among rapeseed genotypes  

Microsoft Academic Search

Cultivation of crop cultivars resistant to high soil manganese (Mn) may reduce the negative effects of Mn toxicity on crop yield. Three studies were carried out to select Brassica genotypes (B. napus and B. rapa) resistant to high Mn concentration and to characterise the nature of any Mn resistance found. In Experiment 1, 33 B. napus and nine B. rapa

J. S. Moroni; B. J. Scott; N. Wratten

2003-01-01

426

Diagnosis and correction of manganese deficiency in corn  

Microsoft Academic Search

Although manganese (Mn) deficiency in soybeans (Glycine max) has been recognized on the Atlantic Coastal Plain, it has not been well recognized in corn (Zea mays) until recent years. Hence, there is a lack of information relating to the diagnosis and correction of Mn deficiency in corn. Field experiments were conducted to determine if the Mn soil test interpretation for

H. J. Mascagni Jr; F. R. Cox

1984-01-01

427

How pharmacokinetic modeling could improve a risk assessment for manganese  

EPA Science Inventory

The neurotoxicity of manganese (Mn) is well established, yet the risk assessment of Mn is made complex by certain enigmas. These include apparently greatertoxicity via inhalation compared to oral exposure and greater toxicity in humans compared to rats. In addition, until recentl...

428

Aqueous ferrofluids based on manganese and cobalt ferrites  

Microsoft Academic Search

Synthesis of two new aqueous ferrofluids is performed chemically according to Massart's procedure. Manganese and cobalt ferrite magnetic particles are precipitated and treated in order to obtain colloidal sols by creating a charge density on their surface. Such ionic ferrofluids can be prepared in an acidic (after a treatment by ferric nitrate) or in an alkaline medium at a concentration

Francisco Augusto Tourinho; Raymonde Franck; Ren Massart

1990-01-01

429

MANGANESE DIOXIDE COATED FILTERS FOR REMOVING RADIUM FROM DRINKING WATER  

EPA Science Inventory

Research was performed using manganese dioxide (MnO2) to demonstrate that above pH3 cations are adsorbed from solution in the order of their affinity, and that the interaction is characterized by the pH dependence of the metal. The relationship of the zero point charge of pH and ...

430

Discovery of Chromium, Manganese, Nickel, and Copper Isotopes  

E-print Network

Twenty-seven chromium, twenty-five manganese, thirty-one nickel and twenty-six copper isotopes have so far been observed and the discovery of these isotopes is discussed. For each isotope a brief synopsis of the first refereed publication, including the production and identification method, is presented.

K. Garofali; R. Robinson; M. Thoennessen

2010-12-07

431

Discovery of Chromium, Manganese, Nickel, and Copper Isotopes  

E-print Network

Twenty-seven chromium, twenty-five manganese, thirty-one nickel and twenty-six copper isotopes have so far been observed and the discovery of these isotopes is discussed. For each isotope a brief synopsis of the first refereed publication, including the production and identification method, is presented.

Garofali, K; Thoennessen, M

2010-01-01

432

INHALATION TOXICOLOGY OF AIRBORNE PARTICULATE MANGANESE IN RHESUS MONKEYS  

EPA Science Inventory

Four male and four female rhesus monkeys were exposed to manganese oxide (Mn3O4) aerosol at 100 micrograms/cubic meter in an exposure chamber for periods up to 66 weeks. Three male and three female monkeys were maintained as unexposed controls. Observation and clinical chemistry ...

433

Formation of nickel, cobalt, manganese and cadmium ferrocyanides.  

PubMed

Potentiometric and solubility studies have been made of the ferrocyanides of nickel, cobalt, manganese(II) and cadmium both in the presence and absence of potassium. The K(3p),DeltaG degrees , DeltaH degrees and DeltaS degrees values are reported. PMID:18961181

Bellomo, A; De Marco, D; Casale, A

1972-10-01

434

Estimating Air-Manganese Exposures in Two Ohio Towns  

EPA Science Inventory

Manganese (Mn), a nutrient required for normal metabolic function, is also a persistent air pollutant and a known neurotoxin at high concentrations. Elevated exposures can result in a number of motor and cognitive deficits. Quantifying chronic personal exposures in residential po...

435

Manganese Oxidation In A Natural Marine Environment- San Antonio Bay  

E-print Network

Cosmochimica Acta 54(3): 781-795. Brewer P.G., Spencer D.W. 1971. Colorimetric Determination of Manganese in Anoxic Waters. Limnology and Oceanography 16(1): 107-110. Brouwers G., De Vrind J.P.M., Corstjens P.L.A.M., Cornelis P., Baysse C., De Vrind- De... ............................................................................................................... 1 STUDY AREA .................................................................................................................... 4 METHODS...

Neyin, Rosemary Ogheneochuko

2013-04-12

436

An investigation of the plastic fracture of AISI 4340 and 18 nickel - 200 grade maraging steels  

NASA Technical Reports Server (NTRS)

The mechanisms of plastic fracture (dimpled rupture) in high-purity and commercial 18 Ni, 200 grade maraging steels and quenched and tempered AISI 4340 steels have been studied. Plastic fracture takes place in the maraging alloys through void initiation by fracture of titanium carbo-nitride inclusions and the growth of these voids until impingement results in coalescence and final fracture. The fracture of AISI 4340 steel at a yield strength of 200 ksi occurs by nucleation and subsequent growth of voids formed by fracture of the interface between manganese sulfide inclusions and the matrix. The growth of these inclusion-nucleated voids is interrupted long before coalescence by impingement, by the formation of void sheets which connect neighboring sulfide-nucleated voids.

Cox, T. B.; Low, J. R., Jr.

1974-01-01

437

Ferromagnetic order in silicon-manganese alloys with phase separation  

SciTech Connect

A phenomenological model of high-temperature ferromagnetism in silicon-manganese alloys has been proposed taking into account phase separation in these alloys, where manganese-rich particles of the secondary phase (precipitate MnSi{sub 2-z} with z Almost-Equal-To 0.25-0.30) are formed inside a manganese-depleted matrix of almost pure silicon. Precipitate MnSi{sub 2-z} is considered as the silicide MnSi{sub 1.7} containing a certain number of magnetic defects whose origin is due to the presence of weakly hybridized 3d orbitals of manganese. The silicide MnSi{sub 1.7} is a weak band ferromagnet in which strong fluctuations of the spin density (paramagnons) are present at a temperature much higher than its Curie temperature. It has been shown that the ferromagnetic exchange interactions between the magnetic moments of defects in precipitate exists due to thermal excitations of the spin density and the ferromagnetic order can appear at a temperature much higher than the Curie temperature of the silicide. The spatial structures and characteristics of this order have been described in the framework of the proposed approach for both homogeneous bulk precipitate and precipitate particles of various shapes and sizes. The short-range magnetic order near the bulk phase transition has been analyzed taking into account inhomogeneities in the distribution of magnetic defects in precipitate. The experimental data on the magnetic properties of silicon-manganese alloys have been interpreted in terms of the theoretical results obtained in this work.

Men'shov, V. N., E-mail: vnmenshov@mail.ru; Tugushev, V. V., E-mail: tuvictor@mail.ru [National Research Centre Kurchatov Institute (Russian Federation)

2011-07-15

438

Hot coal gas desulfurization with manganese-based sorbents  

SciTech Connect

The primary major deposit of manganese in the US which can be readily mined by an in situ process is located in the Emily district of Minnesota. The US Bureau of Mines Research Centers at both the Twin Cities and Salt Lake City have developed a process for extracting and refining manganese in the form of a high-purity carbonate product. This product has been formulated into pellets by a multi-step process of drying, calcination, and induration to produce relatively high-strength formulations which are capable of being used for hot fuel gas desulfurization. These pellets, which have been developed at the University of Minnesota under joint sponsorship of the US Department of Energy and the US Bureau of Mines, appear superior to other, more expensive, formulations of zinc titanate and zinc ferrite which have previously been studied for multi-cycle loading (desulfurization) and regeneration (evolution of high-strength SO{sub 2} and restoration of pellet reactivity). Although these other formulations have been under development for the past twelve years, their prices still exceed $7 per pound. If manganese pellets perform as predicted in fixed bed testing, and if a significant number of utilities which burn high-sulfur coals incorporate combined-cycle gasification with hot coal gas desulfurization as a viable means of increasing conversion efficiencies, then the potential market for manganese pellets may be as high as 200,000 tons per year at a price not less than $3 per pound. This paper discusses the role of manganese pellets in the desulfurization process with respect to the integrated gasification combined-cycle (IGCC) for power generation.

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

1995-11-01

439

Manganese chromium isotope systematics of carbonaceous chondrites  

NASA Astrophysics Data System (ADS)

In this article we present the results of Cr isotope investigations of different types of carbonaceous chondrites and of the pallasite Eagle Station. The 53Cr/ 52Cr ratios in the bulk samples of carbonaceous chondrites are correlated with 55Mn/ 52Cr ratios. The slope of the correlation line yields a 53Mn/ 55Mn ratio of (8.5 1.5) 10 - 6 at the time of Mn/Cr fractionation. Mapping this ratio onto an absolute time scale yields a time for this event of 4568.1 + 0.8/- 1.1 Ma ago. This time is very similar to the formation age of Efremovka CAIs of 4567.2 0.6 Ma [Y. Amelin, A. N. Krot, I. D. Hutcheon, A. A. Ulyanov, Lead isotopic ages of chondrules and calcium-aluminum-rich inclusions, Science 297 (2002) 1678-1683], to a time of the chondrule formation of 4568 1 Ma ago [L.E. Nyquist, D. Lindstrom, D. Mittlefehldt, C.-Y. Shih, H. Wiesmann, S. Wentworth, R. Martinez, Manganese-chromium formation intervals for chondrules from the Bishunpur and Chainpur meteorites, Meteorit. Planet. Sci. 36 (2001) 911-938], which, most likely, constrains early global high-temperature Mn/Cr fractionation in a nebular setting. The bulk samples of carbonaceous chondrites exhibit clear 54Cr excesses ( 54Cr *) that are correlated with the 53Cr excesses ( 53Cr *) and also with Mn/Cr ratios. One possible explanation of this correlation is that 54Cr * is also radiogenic, like 53Cr *, and was formed by the decay of the short-lived parent radionuclide 54Mn. The very short half-life of 54Mn of 312 days would require that both short-lived radionuclides 53Mn and 54Mn were generated locally in spallation reactions during the early period of an active sun. The alternative and possibly more plausible explanation is the heterogeneous addition of presolar material. The presolar component, enriched in 54Cr, is mostly contained in the matrix of carbonaceous chondrites. The relative amount of matrix decreases in the sequence CI > CM > CO,CV. A large proportion of Mn is associated with the matrix while Cr preferentially resides in the chondrules. Thus, the Mn/Cr ratio also follows the sequence CI > CM > CO > CV and is correlated with 54Cr. The acid-resistant residues of carbonaceous chondrites are characterized by relatively large excesses of 54Cr and moderate deficits of 53Cr. The magnitude of these excesses and deficits decreases in the sequence CI, CM, CV and may imply that Cr in the CM, and CV residues is increasingly more equilibrated with Cr from the rest of the meteorites. The 53Cr/ 52Cr and 54Cr/ 52Cr ratios in the residues are anti-correlated indicating that there are at least two Cr components of possibly presolar origin. All residues have large excesses of the most neutron-rich Ti isotope, 50Ti *. The pattern of 50Ti * does not exactly follow that observed for 54Cr * but it is generally similar. The Cr isotope systematic of the pallasite Eagle Station indicates that the precursor of this meteorite was a CV-type material. The 53Mn- 53Cr system indicates that the Cr isotopes equilibrated in this meteorite 4557.5 0.6 Ma ago.

Shukolyukov, A.; Lugmair, G. W.

2006-10-01

440

Effect of hydrogen on internal friction and Young`s modulus of Fe-Cr-Mn austenitic stainless steel  

SciTech Connect

The internal friction technique has so far been applied to studies on hydrogen behavior in iron and steel. The hydrogen cold-work peak is well known for pure iron and has also been observed in BCC iron alloys such as ferritic stainless steel and maraging steel. It provides important information about the hydrogen- dislocation interaction in the BCC iron lattice. Meanwhile, for FCC iron alloys such as austenitic stainless steel, another characteristic hydrogen internal friction peak has been found by authors` group and confirmed by several other investigators. In the present study, type 205 austenitic stainless steel (Fe-17Cr-15Mn) was chosen as a nickel-free FCC iron alloy, in which manganese is totally substituted for nickel in type 304 steel. This steel has an unstable FCC lattice as is the case of type 304 steel, in which hydrogen-induced phase transformation depends on the austenite stability. However, the present steel was confirmed to form the {var_epsilon}{sub H} phase after cathodic hydrogen charging in a similar manner to the stable FCC lattice of type 310 steel. In addition, the Fe-Cr-Mn alloy shows a marked anomaly in the temperature dependence of Young`s modulus: an abrupt drop near the Neel temperature T{sub N} and successive lowering below T{sub N}, as has been reported in the literature for some antiferromagnetic materials. The effect of hydrogen on Young`s modulus was studied by several investigators, but there was great inconsistency among their experimental results. The purpose of this paper is to confirm the hydrogen peak of internal friction in type 205 steel and to examine the effect of hydrogen on Young`s modulus of this steel.

Usui, Makoto [Aichi Steel Works, Ltd., Tokai (Japan). Research Div.] [Aichi Steel Works, Ltd., Tokai (Japan). Research Div.; Asano, Shigeru [Nagoya Inst. of Tech. (Japan). Dept. of Materials Science and Engineering] [Nagoya Inst. of Tech. (Japan). Dept. of Materials Science and Engineering

1996-06-01

441

Manganese reduction by microbes from oxic regions of the Lake Vanda (Antarctica) water column  

SciTech Connect

Depth profiles of metals in Lake Vanda, a permanently ice-covered, stratified Antarctic lake, suggest the importance of particulate manganese oxides in the scavenging, transport, and release of metals. Since manganese oxides can be solubilized by manganese-reducing bacteria, microbially mediated manganese reduction was investigated in Lake Vanda. Microbes concentrated from oxic regions of the water column, encompassing a peak of soluble manganese [Mn(II)], reduced synthetic manganese oxides (MnO{sub 2}) when incubated aerobically, Pure cultures of manganese-reducing bacteria were readily isolated from waters collected near the oxic Mn(II) peak. Based on phylogenetic analysis of the 16S rRNA gene sequence, most of the isolated manganese reducers belong to the genus Carnobacterium. Cultures of a phylogenetically representative strain of Carnobacterium reduced synthetic MnO{sub 2} in the presence of sodium azide, as was seen in field assays. Unlike anaerobes that utilize manganese oxides as terminal electron acceptors in respiration, isolates of the genus Carnobacterium reduced Mn(IV) via a diffusible compound under oxic conditions. The release of adsorbed trace metals accompanying the solubilization of manganese oxides may provide populations of Carnobacterium with a source of nutrients in this extremely oligotrophic environment.

Bratina, B.J.; Stevenson, B.S.; Schmidt, T.M. [Michigan State Univ., East Lansing, MI (United States); Green, W.J. [Miami Univ., Oxford, OH (United States). School of Interdisciplinary Studies

1998-10-01

442

Metabolomic analyses of body fluids after subchronic manganese inhalation in rhesus monkeys.  

PubMed

Neurotoxicity is linked with high-dose manganese inhalation. There are few biomarkers that correlate with manganese exposure. Blood manganese concentrations depend upon the magnitude and duration of the manganese exposure and inconsistently reflect manganese exposure concentrations. The objective of this study was to search for novel biomarkers of manganese exposure in the urine and blood obtained from rhesus monkeys following subchronic manganese sulfate (MnSO(4)) inhalation. Liquid chromatography-mass spectrometry was used to identify putative biomarkers. Juvenile rhesus monkeys were exposed 5 days/week to airborne MnSO(4) at 0, 0.06, 0.3, or 1.5 mg Mn/m(3) for 65 exposure days or 1.5 mg Mn/m(3) for 15 or 33 days. Monkeys exposed to MnSO(4) at >or= 0.06 mg Mn/m(3) developed increased brain manganese concentrations. A total of 1097 parent peaks were identified in whole blood and 2462 peaks in urine. Principal component analysis was performed on a subset of 113 peaks that were found to be significantly changed following subchronic manganese exposure. Using the Nearest Centroid analysis, the subset of 113 significantly perturbed components predicted globus pallidus manganese concentrations with 72.9% accuracy for all subchronically exposed monkeys. Using the five confirmed components, the prediction rate for high brain manganese levels remained > 70%. Three of the five identified components, guanosine, disaccharides, and phenylpyruvate, were significantly correlated with brain manganese levels. In all, 27 metabolites with statistically significant expression differences were structurally confirmed by MS-MS methods. Biochemical changes identified in manganese-exposed monkeys included endpoints relate to oxidative stress (e.g., oxidized glutathione) and neurotransmission (aminobutyrate, glutamine, phenylalanine). PMID:18684773

Dorman, David C; Struve, Melanie F; Norris, Amy; Higgins, Alan J

2008-11-01

443

Potential of dandelion ( Taraxacum officinale) as a bioindicator of manganese arising from the use of methylcyclopentadienyl manganese tricarbonyl in unleaded gasoline  

Microsoft Academic Search

Methylcyclopentadienyl manganese tricarbonyl (MMT) is an organic manganese (Mn) compound currently added to unleaded gasoline in Canada. It has been suggested that the combustion of MMT containing Mn could cause various deleterious health effects in animals and humans at very high concentrations. This study evaluates the potential of dandelions (Taraxacum officinale) as bioindicators of Mn environmental comtamination. Samples were picked

L. Normandin; G. Kennedy; J. Zayed

1999-01-01

444

Nano-sized manganese oxide: a proposed catalyst for water oxidation in the reaction of some manganese complexes and cerium(IV) ammonium nitrate.  

PubMed

According to UV-visible spectroscopy, X-ray diffraction spectrometry, dynamic light scattering, Fourier transform infrared spectroscopy, electron paramagnetic resonance spectroscopy, transmission electron microscopy, scanning electron microscopy and X-ray photoelectron spectroscopy, nano-sized manganese oxides are proposed as active catalysts for water oxidation in the reaction of some manganese complexes and cerium(IV) ammonium nitrate. PMID:22806229

Najafpour, Mohammad Mahdi; Moghaddam, Atefeh Nemati

2012-09-14

445

Steel Industry Wastes.  

ERIC Educational Resources Information Center

Presents a literature review of wastes from steel industry, covering publications of 1976-77. This review covers: (1) coke production; (2) iron and steel production; (3) rolling operations; and (4) surface treatment. A list of 133 references is also presented. (NM)

Schmidtke, N. W.; Averill, D. W.

1978-01-01

446

Steel industry wastes  

SciTech Connect

In this annual literature review, the regulations of the EPA which apply to the steel industry are discussed. Coke plant wastes are discussed. The characterization of the suspended solids in steel plant river intake water and in plant discharge effluent by electron-optical and x-ray diffraction techniques are discussed. 12 references.

Chung, N.K.

1985-06-01

447

Steels for parts of the propulsion system of industrial caterpillar tractors  

SciTech Connect

New steels were developed for the track shoes and track links of tractors used for the mining of ore, coal, and gold and for the construction of gas and oil lines in the Soviet Union. Steels 40KhFR (for the shoes) and 40GMFR (for the links), alloyed with chromium (up to 1.0%) or manganese (up to 1.2%) with additional microalloying with boron, titanium, and aluminum and with small additions of vanadium (up to 0.10%) and molybdenum (up to 0.16%), were used as base steels. The influence of microalloying was revealed in increases in the depth of hardenability and in impact strength. The steels are fine grained with increased cold resistance both in the high strength and hardened and tempered conditions. Optimum final heat-treat cycles were determined. An analysis of service data showed that the life of parts of the new steels is more than twice as long as of parts of the previously used steels.

Spirkina, G.V.; Efimova, L.B.

1988-05-01

448

Adsorption of selenium by amorphous iron oxyhydroxide and manganese dioxide  

USGS Publications Warehouse

This work compares and models the adsorption of selenium and other anions on a neutral to alkaline surface (amorphous iron oxyhydroxide) and an acidic surface (manganese dioxide). Selenium adsorption on these oxides is examined as a function of pH, particle concentration, oxidation state, and competing anion concentration in order to assess how these factors might influence the mobility of selenium in the environment. The data indicate that 1. 1) amorphous iron oxyhydroxide has a greater affinity for selenium than manganese dioxide, 2. 2) selenite [Se(IV)] adsorption increases with decreasing pH and increasing particle concentration and is stronger than selenate [Se(VI)] adsorption on both oxides, and 3. 3) selenate does not adsorb on manganese dioxide. The relative affinity of selenate and selenite for the oxides and the lack of adsorption of selenate on a strongly acidic surface suggests that selenate forms outer-sphere complexes while selenite forms inner-sphere complexes with the surfaces. The data also indicate that the competition sequence of other anions with respect to selenite adsorption at pH 7.0 is phosphate > silicate > molybdate > fluoride > sulfate on amorphous iron oxyhydroxide and molybdate ??? phosphate > silicate > fluoride > sulfate on manganese dioxide. The adsorption of phosphate, molybdate, and silicate on these oxides as a function of pH indicates that the competition sequences reflect the relative affinities of these anions for the surfaces. The Triple Layer surface complexation model is used to provide a quantitative description of these observations and to assess the importance of surface site heterogeneity on anion adsorption. The modeling results suggest that selenite forms binuclear, innersphere complexes with amorphous iron oxyhydroxide and monodentate, inner-sphere complexes with manganese dioxide and that selenate forms outer-sphere, monodentate complexes with amorphous iron oxyhydroxide. The heterogeneity of the oxide surface sites is reflected in decreasing equilibrium constants for selenite with increasing adsorption density and both experimental observations and modeling results suggest that manganese dioxide has fewer sites of higher energy for selenite adsorption than amorphous iron oxyhydroxide. Modeling and interpreting the adsorption of phosphate, molybdate, and silicate on the oxides are made difficult by the lack of constraint in choosing surface species and the fact that equally good fits can be obtained with different surface species. Finally, predictions of anion competition using the model results from single adsorbate systems are not very successful because the model does not account for surface site heterogeneity. Selenite adsorption data from a multi-adsorbate system could be fit if the equilibrium constant for selenite is decreased with increasing anion adsorption density. ?? 1990.

Balistrieri, L.S.; Chao, T.T.

1990-01-01

449

Manganese reduction and its stabilization in the rock record  

NASA Astrophysics Data System (ADS)

Manganese oxides are abundant and highly reactive electron acceptors present within many environments. Their occurance is intimately tied to the availability of oxygen, as only O2 and oxygen-derived species such as superoxide and peroxide can oxidize reduced Mn(II). Because Mn2+ is soluble and Mn3+ and Mn4+ readily undergo hydrolysis to form insoluble precipitates, the record of manganese in sedimentary deposits can yield interesting insights into the history of atmospheric oxygen--the largest manganese deposits in Earth history (approximately 2.2 billion years ago) are associated with the rise of oxygen. From studying modern environments, we understand that manganese is concentrated in sediments by the oxidation and deposition of Mn(IV) minerals; however, our observations of the geologic record show diagenetic stabilization of only Mn(II) carbonate or mixed Mn(II)-Mn(III) oxide minerals--all Mn(IV)-oxide phases in ancient samples are associated with modern weathering and oxidation processes. Reduction is a key element within the manganese cycle, yet the (bio)geochemical processes responsible for the formation of mixed Mn(II)-Mn(III) minerals have not been fully elucidated. To better understand how manganese is converted from insoluble Mn(IV) oxide to these Mn(II/III)-bearing phases, we investigated secondary mineral precipitates which form during and after Mn(IV)-oxide reduction using a well-studied metal-reducing bacteria, Shewanella oneidensis MR-1. To examine changes in Mn mineralogy and oxidation state during the progression of Mn(IV) reductive dissolution/transformation by S. oneidensis, we utilized a flow through reactor system allowing for in-situ and real time x-ray absorption spectroscopy (XAS) measurements. We also confirmed mineral phases using XRD and FTIR spectrometry. Our experiments reveal that when solution phosphate concentrations are high, a Mn(II) phosphate phase quickly forms as a secondary precipitate during complete reduction of Mn(IV) oxides. However, when phosphate is excluded, either complete or incomplete reduction may ensue. When incomplete reduction occurs, the dominant solid phase at the end of experimentation is a Mn(III)-bearing oxide, but in experiments with complete Mn(VI) reduction, we observe either the formation of Mn carbonate(s), or complete dissolution (no secondary precipitates) depending on the presence of organic ligands and carbonate chemistry of the media. Accordingly, we will discuss (bio)geochemical mechanisms which may explain Mn stabilization within sediments as Mn(II)-carbonate and Mn(III)-dominated minerals, and relate them to observations of Mn within the rock record.

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

2013-12-01

450

Manganese accumulation in soil and plants along Utah roadways: A possible indication of motor vehicle exhaust pollution  

SciTech Connect

An organic manganese compound is currently added to gasoline to replace tetraethyl lead as an antiknock fuel additive in the U.S. and Canada. Combustion exhaust gases contain manganese oxides. Manganese oxides are known to cause various deleterious health effects in experimental animals and humans. A field survey of roadside soil and plants in central Utah revealed that soil manganese concentrations in high traffic areas were up to 100-fold higher than historic lead levels. Soil manganese concentrations were highly correlated with distance from the roadway. In addition, roadside aquatic plants were higher in leaf tissue manganese than herbs or grasses. Submerged and emergent aquatic plants were sensitive bioindicators of manganese contamination. Manganese concentrations in soil and in some plant species along impacted roadsides often exceeded levels known to cause toxicity. We conclude that roadside soil and plants were apparently contaminated by manganese oxides from Mn-containing motor vehicle exhaust.

Lytle, C.M.; Smith, B.N.; McKinnon, C.Z. [Brigham Young Univ., Provo, UT (United States)

1995-06-01

451

Hot Tearing Modeling: A Microstructural Approach Applied to Steel Solidification  

NASA Astrophysics Data System (ADS)

Hot tearing during solidification processes has been deeply investigated in past and recent years through testing, modeling, and development of a number of macroscopic hot tearing criteria. The objective is predicting the crack occurrence during industrial solidification processes, which, in the steel production, are mainly ingot and continuous casting. The present work is inspired by the criterion proposed in the work of Bellet et al.[1] called CBC criterion, from which the methodological approach and experimental data used for calibration, related to nine carbon steels, have been derived. The proposed hot tearing criterion adopts as parameters: primary and secondary arm spacing, the mechanical resistance near the solidus temperature, the solidification parameters G (gradient) and v (dendrite tip velocity), the brittle range extension in the dendritic front and the temperature of formation of manganese sulfides. The new formulation is an attempt to substitute to brittle temperature range and steel content, appearing in the CBC criterion, the dendritic structure characteristics, in the aim of: (a) moving toward a generalized expression of the cracking index applicable to different steel classes; (b) introducing the dependence of the crack susceptibility on the cooling conditions. The agreement of the new hot tearing index values with the experimental ones is of the same kind as that of the CBC criterion, indicating that the parameters and the dependences adopted in the new criterion make a sense. Further study and experimental work are needed to assess the influence of the microstructure morphology on the hot cracking sensitivity and to check the suitability of the approach to a wider range of steel compositions.

Ridolfi, Maria Rita

2014-08-01

452

EAST ELEVATION, LTV STEEL (FORMERLY REPUBLIC STEEL), 8" BAR MILL, ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

EAST ELEVATION, LTV STEEL (FORMERLY REPUBLIC STEEL), 8" BAR MILL, BUFFALO PLANT. VIEW LOOKING SOUTHWEST FROM ROLL SHOP. 8" BAR MILL DESIGNED AND BUILT BY DONNER STEEL CO. (PREDECESSOR OF REPUBLIC), 1919-1920. FOR DESCRIPTION OF ORIGINAL MILL SEE "IRON AGE", 116\\4 (23 JULY 1925): 201-204. - LTV Steel, 8-inch Bar Mill, Buffalo Plant, Buffalo, Erie County, NY

453

STEEL: RECENT PUBLICATIONS HAMPSON, G. J., STEEL, R. J., BURGESS,  

E-print Network

STEEL: RECENT PUBLICATIONS HAMPSON, G. J., STEEL, R. J., BURGESS, P. M. and R. W. DALRYMPLE, (in of Siliciclastic Shallow-Marine Stratigraphy. SEPM Spec. Publication 90. STEEL, R.J., CARVAJAL, C., PETTER, A. THOMAS P. GERBER, LINCOLN F. PRATSON, MATTHEW A.WOLINSKY, RON STEEL, JER MOHR, JOHN B. SWENSON CHRIS

Yang, Zong-Liang

454

Manganese oxide nanowires, films, and membranes and methods of making  

DOEpatents

Nanowires, films, and membranes comprising ordered porous manganese oxide-based octahedral molecular sieves, and methods of making, are disclosed. A single crystal ultra-long nanowire includes an ordered porous manganese oxide-based octahedral molecular sieve, and has an average length greater than about 10 micrometers and an average diameter of about 5 nanometers to about 100 nanometers. A film comprises a microporous network comprising a plurality of single crystal nanowires in the form of a layer, wherein a plurality of layers is stacked on a surface of a substrate, wherein the nanowires of each layer are substantially axially aligned. A free standing membrane comprises a microporous network comprising a plurality of single crystal nanowires in the form of a layer, wherein a plurality of layers is aggregately stacked, and wherein the nanowires of each layer are substantially axially aligned.

Suib, Steven Lawrence (Storrs, CT); Yuan, Jikang (Storrs, CT)

2008-10-21

455

First principle study of manganese doped cadmium sulphide sheet  

NASA Astrophysics Data System (ADS)

First-principle electronic structure calculations for cadmium sulphide (CdS) sheet in hexagonal phase, with Manganese substitution and addition, as well as including the Cd defects, are investigated. The lattice constants calculated for CdS sheet agrees fairly well with results reported for thin films experimentally. The calculations of total spin density of states and partial density of states in different cases shows substantial magnetic dipole moments acquired by the sheet. A magnetic dipole moment 5.00612 ?B and band gap of the order 1 eV are found when cadmium atom is replaced by Manganese. The magnetism acquired by the sheet makes it functionally important candidate in many applications.

Kumar, Sanjeev; Kumar, Ashok; Ahluwalia, P. K.

2014-04-01

456

Polyaspartic acid coated manganese oxide nanoparticles for efficient liver MRI  

NASA Astrophysics Data System (ADS)

We report in this communication a simple, facile surface modification strategy to transfer hydrophobic manganese oxide nanoparticles (MONPs) into water by using polyaspartic acid (PASP). We systematically investigated the effect of the size of PASP-MONPs on MRI of normal liver and found that the particles with a core size of 10 nm exhibited greater enhancement than those with larger core sizes.We report in this communication a simple, facile surface modification strategy to transfer hydrophobic manganese oxide nanoparticles (MONPs) into water by using polyaspartic acid (PASP). We systematically investigated the effect of the size of PASP-MONPs on MRI of normal liver and found that the particles with a core size of 10 nm exhibited greater enhancement than those with larger core sizes. Electronic supplementary information (ESI) available. See DOI: 10.1039/c1nr11242b

Xing, Ruijun; Zhang, Fan; Xie, Jin; Aronova, Maria; Zhang, Guofeng; Guo, Ning; Huang, Xinglu; Sun, Xiaolian; Liu, Gang; Bryant, L. Henry; Bhirde, Ashwinkumar; Liang, Amy; Hou, Yanglong; Leapman, Richard D.; Sun, Shouheng; Chen, Xiaoyuan

2011-12-01

457

First principle study of manganese doped cadmium sulphide sheet  

SciTech Connect

First-principle electronic structure calculations for cadmium sulphide (CdS) sheet in hexagonal phase, with Manganese substitution and addition, as well as including the Cd defects, are investigated. The lattice constants calculated for CdS sheet agrees fairly well with results reported for thin films experimentally. The calculations of total spin density of states and partial density of states in different cases shows substantial magnetic dipole moments acquired by the sheet. A magnetic dipole moment 5.00612 ?{sub B} and band gap of the order 1 eV are found when cadmium atom is replaced by Manganese. The magnetism acquired by the sheet makes it functionally important candidate in many applications.

Kumar, Sanjeev, E-mail: drskumar11@gmail.com [Department of Physics, St. Bede's College, Shimla-171002 (India); Kumar, Ashok; Ahluwalia, P. K. [Department of Physics, Himachal Pradesh University, Shimla-171005 (India)

2014-04-24

458

Manganese: Recent advances in understanding its transport and neurotoxicity  

SciTech Connect

The present review is based on presentations from the meeting of the Society of Toxicology in San Diego, CA (March 2006). It addresses recent developments in the understanding of the transport of manganese (Mn) into the central nervous system (CNS), as well as brain imaging and neurocognitive studies in non-human primates aimed at improving our understanding of the mechanisms of Mn neurotoxicity. Finally, we discuss potential therapeutic modalities for treating Mn intoxication in humans.

Aschner, Michael [Departments of Pediatrics, Pharmacology, and Kennedy Center for Research on Human Development, B-3307 Medical Center North, Vanderbilt University, School of Medicine, Nashville, TN 37232-2495 (United States)]. E-mail: Michael.Aschner@vanderbilt.edu; Guilarte, Tomas R. [Neurotoxicology and Molecular Imaging Laboratory, Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD (United States); Schneider, Jay S. [Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA (United States); Zheng Wei [School of Health Sciences, Purdue University, West Lafayette, IN (United States)

2007-06-01

459

The manganese superoxide dismutase from the penicillin producer Penicillium chrysogenum  

Microsoft Academic Search

The antioxidant enzyme superoxide dismutase has been studied in order to define mechanisms for the influence of oxygen on\\u000a penicillin production. Manganese-containing SOD activity was purified from penicillin-producing cultures of the filamentous\\u000a fungus Penicillium chrysogenum and reverse genetics was used to identify full-length cDNA and genomic clones. Sequence analysis revealed a 630-bp ORF containing\\u000a three exons and two introns with

Bruno Dez; Carmen Schleissner; Miguel Angel Moreno; Marta Rodrguez; Alfonso Collados; Jos Luis Barredo

1998-01-01

460

Possible Health Effects of High Manganese Concentration in Drinking Water  

Microsoft Academic Search

Three areas in the same region of northwest Peloponnesos, Greece, that had varying concentrations of manganese (Mn) in drinking water were selected for study. The Mn concentrations in areas A, B, and C were 3.614.6 ?g\\/I, 81.6252.6 ?g\\/I, and 1 8002 300 ?g\\/I, respectively. A random sample (62 in area A, 49 in area B, and 77 in area C)

Xenophon G. Kondakis; Nicolas Makris; Michael Leotsinidis; Mary Prinou; Theodore Papapetropoulos

1989-01-01

461

Manganese toxicity in children receiving long-term parenteral nutrition  

Microsoft Academic Search

SummaryBackground In patients receiving long-term parenteral nutrition (PN), cholestatic disease and nervous system disorders have been associated with high blood concentrations of manganese. In such patients, the normal homoeostatic mechanisms of the liver and gut are bypassed and the requirement for this trace element is not known; nor has it been certain whether hyper-manganesaemia causes the cholestasis or vice versa.

J. M. E Fell; N Meadows; K Khan; S. G Long; P. J Milla; A. P Reynolds; G Quaghebeur; W. J Taylor

1996-01-01

462

Toxicity of manganese to Ceriodaphnia dubia and Hyalella azteca  

USGS Publications Warehouse

Manganese is a toxic element frequently overlooked when assessing toxicity of effluents, sediments and pore waters. Manganese can be present at toxic levels in anoxic solutions due to its increased solubility under chemically-reducing conditions, and it can remain at those levels for days in aerated test waters due to slow precipitation kinetics. Ceriodaphnia dubia and Hyalella azteca are freshwater organisms often used for toxicity testing and recommended for assessments of effluents and pore waters. Lethal and reproductive-inhibition concentrations of Mn were determined for C. dubia in acute 48h tests and chronic 3-brood tests using animals <24 h old and between 24 and 48 h old. Sensitivity of H. azteca was determined with 7d old animals in acute 96h tests. Tests were run at three levels of water hardness to assess the amelioratory effect, which was often significant. Manganese concentrations were measured analytically at test initiation and after 96 h for calculations of toxicity endpoints and determinations of Mn precipitation during the tests. Minimal amounts of Mn (below 3%) precipitated within 96 h. LC50s determined for H. azteca progressively increased from 3.0 to 8.6 to 13.7 mg Mn/L in soft, moderately-hard and hard waters, respectively. The tolerance of C. dubia to Mn was not significantly different between moderately-hard and hard waters, but was significantly lower in soft water. There was no significant difference in Mn sensitivity between the ages of C. dubia tested. Acute LC50 values for C. dubia averaged 6.2, 14.5 and 15.2 mg Mn/L and chronic IC50 values averaged 3.9, 8.5 and 11.5 mg Mn/L for soft, moderately-hard and hard waters, respectively. Manganese toxicity should be considered when assessing solutions with concentrations near these levels.

Lasier, P.J.; Winger, P.V.; Bogenrieder, K.J.

2000-01-01

463

Manganese and Zinc Toxicity Thresholds for Mountain and Geyer Willow  

Microsoft Academic Search

Information on the heavy metal toxicity thresholds of woody species endemic to the western United States is lacking but critical for successful restoration of contaminated riparian areas. Manganese (Mn, 5010,000 mg l) and zinc (Zn, 1001000 mg l) toxicity thresholds were determined for Geyer (Salix geyeriana Anderss.) and mountain (S. monticola Bebb) willow using a sand-culture technique. The lethal concentration

Jennifer O. Shanahan; Joe E. Brummer; Wayne C. Leininger; Mark W. Paschke

2007-01-01

464

Nanostructured cobalt manganese ferrite thin films for gas sensor application  

Microsoft Academic Search

Ferrite compounds are very important because of their optical, electrical or magnetic properties. Moreover, many papers relate to their development as possible gas sensor.In this study, we were interested in using cobaltmanganeseferrite as sensitive layer for CO2 sensor devices. Such an application required a high surface activity, and consequently a small crystallite size and a large surface area. The physical

Izabela Sandu; Lionel Presmanes; Pierre Alphonse; Philippe Tailhades

2006-01-01

465

Polyaspartic acid coated manganese oxide nanoparticles for efficient liver MRI.  

PubMed

We report in this communication a simple, facile surface modification strategy to transfer hydrophobic manganese oxide nanoparticles (MONPs) into water by using polyaspartic acid (PASP). We systematically investigated the effect of the size of PASP-MONPs on MRI of normal liver and found that the particles with a core size of 10 nm exhibited greater enhancement than those with larger core sizes. PMID:22064945

Xing, Ruijun; Zhang, Fan; Xie, Jin; Aronova, Maria; Zhang, Guofeng; Guo, Ning; Huang, Xinglu; Sun, Xiaolian; Liu, Gang; Bryant, L Henry; Bhirde, Ashwinkumar; Liang, Amy; Hou, Yanglong; Leapman, Richard D; Sun, Shouheng; Chen, Xiaoyuan

2011-12-01

466

Polyaspartic acid coated manganese oxide nanoparticles for efficient liver MRI  

PubMed Central

We report in this communication a simple, facile surface modification strategy to transfer hydrophobic manganese oxide nanoparticles (MONPs) into water by using polyaspartic acid (PASP). We systematically investigated the effect of the size of PASP-MONPs on MRI of normal liver and found that the particles with a core size of 10 nm exhibited greater enhancement than those with larger core sizes. PMID:22064945

Xing, Ruijun; Zhang, Fan; Xie, Jin; Aronova, Maria; Zhang, Guofeng; Guo, Ning; Huang, Xinglu; Sun, Xiaolian; Liu, Gang; Bryant, L. Henry; Bhirde, Ashwinkumar; Liang, Amy; Hou, Yanglong; Leapman, Richard D.; Sun, Shouheng; Chen, Xiaoyuan

2013-01-01

467

Manganese (Mn) and Iron (Fe): Interdependency of Transport and Regulation  

Microsoft Academic Search

Manganese (Mn) and iron (Fe) are transition metals that are crucial to the appropriate growth, development, function, and\\u000a maintenance of biological organisms. Because of their chemical similarity, in organisms ranging from bacteria to mammals they\\u000a share and compete for many protein transporters, such as the divalent metal transporter-1. As such, during conditions of low\\u000a Fe, abnormal Mn accumulation occurs. Conversely,

Vanessa A. Fitsanakis; Na Zhang; Stephanie Garcia; Michael Aschner

2010-01-01

468

Giant magnetoresistance of manganese oxides with a layered perovskite structure  

Microsoft Academic Search

MANGANESE oxides with the cubic perovskite structure (typified by LaMnO3) have stimulated considerable interest because of their magnetoresistive properties1-9 they exhibit extremely large changes in electrical resistance in response to applied magnetic fields, a property that is of technological relevance for the development of magnetic memory and switching devices. But for such applications to be viable, great improvements will be

Y. Moritomo; A. Asamitsu; H. Kuwahara; Y. Tokura

1996-01-01

469

Manganese deposits on Mars suggest a highly oxidized past  

NASA Astrophysics Data System (ADS)

As the Curiosity rover picks its way across the Martian surface, sampling rocks and snapping photos, it searches for signs that the dusty craters and ridges under its treads may once have supported life or, at least, that they might have been habitable. Now, using measurements of manganese abundances in Martian rocks, Lanza et al. provide new evidence that Mars may have hosted liquid water and a more strongly oxygenated atmosphere at some point in its past.

Rosen, Julia

2014-11-01

470

Catalysis of peroxynitrite reactions by manganese and iron porphyrins.  

PubMed

Kinetics and products of peroxynitrite anion O=NOO- reactions, catalyzed by water-soluble manganese and iron porphyrins, were studied under basic and neutral conditions. In the absence of organic substrates peroxynitrite decomposes catalytically to give nitrite and dioxygen as major products. Catalytic decomposition competes with direct oxidation of sulfoxide to sulfone, while phenol is catalytically nitrated in o- and p-positions. A reaction mechanism is proposed. PMID:9466957

Balavoine, G G; Geletti, Y V; Bejan, D

1997-01-01

471

Iron-manganese nodules from nares abyssal plain: geochemistry and mineralogy.  

PubMed

Three nodules from a core taken north of Puerto Rico are composed chiefly of an x-ray amorphous, hydrated, iron-manganese oxide, with secondary goethite, and minor detrital silicates incorporated during growth of the nodules. No primary manganese mineral is apparent. The nodules are enriched in iron and depleted in manganese relative to Atlantic Ocean averages. The formation of these nodules appears to have been contemporary with sedimentation and related to volcanic activity. PMID:17802621

Smith, R E; Gassaway, J D; Giles, H N

1968-08-23

472

Biogeochemistry of manganese- and iron-rich sediments in Toolik Lake, Alaska  

Microsoft Academic Search

The sediments within Toolik Lake in arctic Alaska are characterized by extremely low rates of organic matter sedimentation\\u000a and unusually high concentrations of iron and manganese. Pore water and solid phase measurements of iron, manganese, trace\\u000a metals, carbon, nitrogen, phosphorus, and sulfur are consistent with the hypothesis that the reduction of organic matter by\\u000a iron and manganese is the most

Jeffrey C. Cornwell; George W. Kipphut

1992-01-01

473

Preparation and characterization of manganese oxide\\/CNT composites as supercapacitive materials  

Microsoft Academic Search

Manganese oxide was synthesized and dispersed on carbon nanotube (CNT) matrix by thermally decomposing manganese nitrates. CNTs used in this paper were grown directly on graphite disk by chemical vapor deposition technique. The capacitive behavior of manganese oxide\\/CNT composites was investigated by cyclic voltammetry and galvanostatic chargedischarge method in 1 M Na2SO4 aqueous solutions. When the loading mass of MnO2

Zhen Fan; Jinhua Chen; Mingyong Wang; Kunzai Cui; Haihui Zhou; Yafei Kuang

2006-01-01

474

Determination of manganese in ores by activation analysis using a californium-252 neutron source  

Microsoft Academic Search

A252Cf neutron source has been used to analyse manganese in ores such as pyrolusite, rodonite (manganese silicate) and blends\\u000a used in dry-batteries. Samples with about 150 mg and standards of manganese dioxide were irradiated for about 20 min and counted\\u000a using a well-type NaI(Tl) scintillation counter and scaler, with or without pulse-height discriminator between the detector\\u000a and the scaler. The

A. Cardoso; F. W. Lima

1977-01-01

475

Growth and characterization of gel grown pure and mixed iron-manganese levo-tartrate crystals  

Microsoft Academic Search

Several applications of iron tartrate and manganese tartrate compounds are reported in the literature. In the present investigation,\\u000a we have grown pure and mixed iron (II)-manganese levo-tartrate crystals by single diffusion gel growth technique. Crystals\\u000a with spherulitic morphology were harvested. The colouration of the crystals changed from black to pinkish brown upon increasing\\u000a the content of manganese in the crystals.

S. J. Joshi; B. B. Parekh; K. D. Vohra; M. J. Joshi

2006-01-01

476

Steel initiative: Development of superplastic steel processing  

Microsoft Academic Search

The influence of aluminum content and thermomechanical processing steps on developing fine microstructures in ultrahigh carbon steels (UHCS) was examined. The presence of aluminum results in ultrafine pearlitic structures without proeutectoid carbide networks, and greatly retards the eutectoid transformation kinetics. This retardation facilitates processing, which involves various combinations of DET and DETWAD steps. By applying the transformation kinetics as a

D. H. Sherman; J. M. Leach; A. F. Hayes; J. A. Lemsky; J. D. Thomas; G. H. Geiger; A. Goldberg; M. J. Strum; O. D. Sherby; WI Cudahy; North Star Steel Co; MI Monroe

1989-01-01

477

A redox-assisted supramolecular assembly of manganese oxide nanotube  

SciTech Connect

In this paper, we report the hydrothermal synthesis of manganese oxide nanotube from an aqueous medium of pH 7, using KMnO{sub 4} and MnCl{sub 2} as inorganic precursors, polyoxyethylene (10) nonyl phenyl ether (TX-10) a surfactant and acetaldehyde an additive. The characterization of X-ray diffraction (XRD), transmission electron microscopy (TEM), selected area electron diffraction (SAED) and N{sub 2} adsorption at 77 K (BET) reveals that the synthesized manganese oxide nanotube has a mesopore size of ca. 3.65 nm and a wall thickness of ca. 12 nm, with the wall being composed of microporous crystals of monoclinic manganite. The X-ray photoelectron spectroscopy (XPS) result demonstrates a decrease of the binding energy of the Mn{sup 3+} in the manganese oxide nanotube, which may be related to both the nanotubular morphology and the crystalline pore wall. A mechanism of a redox-assisted supramolecular assembly, regulated by acetaldehyde, is postulated.

Tao Li [College of Chemistry and Chemical Engineering, Hunan University, Key Laboratory of Chemometrics and Chemical Biological Sensing Technologies, Ministry of Education, Changsha 410082 (China); Sun Chenggao [College of Chemistry and Chemical Engineering, Hunan University and Key Laboratory of Chemometrics and Chemical Biological Sensing Technologies, Ministry of Education, Changsha 410082 (China); Fan Meilian [College of Chemistry and Chemical Engineering, Hunan University, Key Laboratory of Chemometrics and Chemical Biological Sensing Technologies, Ministry of Education, Changsha 410082 (China); Huang Caijuan [College of Chemistry and Chemical Engineering, Hunan University, Key Laboratory of Chemometrics and Chemical Biological Sensing Technologies, Ministry of Education, Changsha 410082 (China); Wu Hailong [College of Chemistry and Chemical Engineering, Hunan University, Key Laboratory of Chemometrics and Chemical Biological Sensing Technologies, Ministry of Education, Changsha 410082 (China); Chao Zisheng [College of Chemistry and Chemical Engineering, Hunan University, Key Laboratory of Chemometrics and Chemical Biological Sensing Technologies, Ministry of Education, Changsha 410082 (China)]. E-mail: zschao@yahoo.com; Zhai Hesheng [College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005 (China)]. E-mail: hszhai@xmu.edu.cn

2006-11-09

478

Laser microstructuring and annealing processes for lithium manganese oxide cathodes  

NASA Astrophysics Data System (ADS)

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 were synthesized by non-reactive radiofrequency magnetron sputtering of a spinel lithium manganese oxide target. For the enhancement of the power density and cycle stability, large area direct laser patterning using UV-laser radiation with a wavelength of 248 nm was performed. Subsequent laser annealing processes were investigated in a second step in order to set up a spinel-like phase using 940 nm laser radiation at a temperature of 680 C. The interaction processes between UV-laser radiation and the material was investigated using laser ablation inductively coupled plasma mass spectroscopy. The changes in phase, structure and grain shape of the thin films due to the annealing process were recorded using Raman spectroscopy, X-ray diffraction and scanning electron microscopy. The structured cathodes were cycled using standard electrolyte and a metallic lithium anode. Different surface structures were investigated and a significant increase in cycling stability was found. Surface chemistry of an as-deposited as well as an electrochemically cycled thin film was investigated via X-ray photoelectron spectroscopy.

Prll, J.; Kohler, R.; Torge, M.; Ulrich, S.; Ziebert, C.; Bruns, M.; Seifert, H. J.; Pfleging, W.

2011-09-01

479

Characterisation of chemically lithiated heat-treated electrolytic manganese dioxide  

SciTech Connect

Highlights: ? Manganese oxides are a promising cathode material for lithium ion batteries. Here we examine the structural and morphological changes that occur upon reduction, and assess its impact on material performance. ? Upon reduction, MnO{sub 2} transforms into LiMn{sub 2}O{sub 4}, which is subsequently reduced to Li{sub 2}Mn{sub 2}O{sub 4}. ? Significant morphological changes occur, particularly to the material porosity. ? This transformation for MnO{sub 2} has not been reported previously. -- Abstract: Heat treated manganese dioxide is partially lithiated using butyl-lithium to determine the changes in crystal structure, chemical composition and morphology upon reduction, as a means of simulating its discharge behaviour in a non-aqueous battery cathode. As reduction proceeds, and lithium ions are inserted into the heat treated electrolytic manganese dioxide (EMD) structure, the material undergoes a phase transition to LiMn{sub 2}O{sub 4}. This new phase is further reduced to Li{sub 2}Mn{sub 2}O{sub 4}. Reduction initially results in a 56% decrease in the surface area of the material; however, at higher degrees of reduction a slight increase in this value is observed, as a consequence of the strain placed on the lattice through continued lithium insertion.

Dose, Wesley M.; Lehr, Joshua [Discipline of Chemistry, University of Newcastle, Callaghan, NSW 2308 (Australia)] [Discipline of Chemistry, University of Newcastle, Callaghan, NSW 2308 (Australia); Donne, Scott W., E-mail: scott.donne@newcastle.edu.au [Discipline of Chemistry, University of Newcastle, Callaghan, NSW 2308 (Australia)

2012-07-15

480

The corrosive nature of manganese in drinking water.  

PubMed

Corrosion problems having to do with drinking water distribution systems are related to many processes and factors and two of them are ionic acidity and carbon dioxide, which were considered in this work. The corrosion character of water is determined by the corrosion indexes of Langelier, Ryznar, Larson, and Mojmir. The results show that pipes made of different materials, such as plastics or metals, are affected by corrosion, causing manganese to be deposited on materials and dissolved in water. The deterioration of the materials, the degree of corrosion, and the deposited corrosion products were determined by X-ray diffraction and Scanning Electron Microscopy. High levels of manganese and nitrate ions in water may cause serious damage to the health of consumers of water. Three wells were examined, one of them presented a high content of manganese; the others had high levels of nitrate ions, which increased the acidity of the water and, therefore, the amount of corrosion of the materials in the distribution systems. PMID:23376288

Alvarez-Bastida, C; Martnez-Miranda, V; Vzquez-Meja, G; Solache-Ros, M; Fonseca-Montes de Oca, G; Trujillo-Flores, E

2013-03-01

481

Characterization of Synthetic and Natural Manganese Oxides as Martian Analogues  

NASA Technical Reports Server (NTRS)

Recent discoveries of highly concentrated manganese oxides in Gale Crater and on the rim of Endeavour Crater by the Mars Science Laboratory Curiosity and Mars Exploration Rover Opportunity, respectively, imply more highly oxidizing aqueous conditions than previously recognized. Manganese oxides are a significant environmental indicator about ancient aqueous conditions, provided the phases can be characterized reliably. Manganese oxides are typically fine-grained and poorly crystalline, making the mineral structures difficult to determine, and they generally have very low visible reflectance with few distinctive spectral features in the visible to near infrared, making them a challenge for interpretation from remote sensing data. Therefore, these recent discoveries motivate better characterization using methods available on Mars, particularly visible to near infrared (VNIR) spectroscopy, X-ray diffractometry (XRD), and compositional measurements. Both rovers have complementary instruments in this regard. Opportunity is equipped with its multispectral visible imager, Pancam, and an Alpha Particle X-ray Spectrometer (APXS), and Curiosity has the multispectral Mastcam, ChemCam (laser-induced breakdown spectroscopy and passive spectroscopy), and APXS for in situ characterization, and ChemMin (XRD) for collected samples.

Fox, V. K.; Arvidson, R. E.; Jolliff, B. L.; Carpenter, P. K.; Catalano, J. G.; Hinkle, M. A. G.; Morris, R. V.

2015-01-01

482

[Manganese uptake and transportation as well as antioxidant response to excess manganese in plants].  

PubMed

Manganese (Mn) is an essential micronutrient throughout all stages of plant development. Mn plays an important role in many metabolic processes in plants. It is of particular importance to photosynthetic organisms in the chloroplast of which a cluster of Mn atoms at the catalytic centre function in the light-induced water oxidation by photosystem II, and also function as a cofactor for a variety of enzymes, such as Mn-SOD. But excessive Mn is toxic to plants which is one of the most toxic metals in acid soils. The knowledge of Mn(2+) uptake and transport mechanisms, especially the genes responsible for transition metal transport, could facilitate the understanding of both Mn tolerance and toxicity in plants. Recently, several plant genes were identified to encode transporters with Mn(2+) transport activity, such as zinc-regulated transporter/iron-regulated transporter (ZRT/IRT1)-related protein (ZIP) transporters, natural resistance-associated macrophage protein (Nramp) transporters, cation/H(+) antiporters, the cation diffusion facilitator (CDF) transporter family, and P-type ATPase. In addition, excessive Mn frequently induces oxidative stress, then several defense enzymes and antioxidants are stimulated to scavenge the superoxide and hydrogen peroxide formed under stress. Mn-induced oxidative stress and anti-oxidative reaction are very important mechanisms of Mn toxicity and Mn tolerance respectively in plants. This article reviewed the transporters identified as or proposed to be functioning in Mn(2+) transport, Mn toxicity-induced oxidative stress, and the response of antioxidants and antioxidant enzymes in plants to excessive Mn to facilitate further study. Meanwhile, basing on our research results, new problems and views are brought forward. PMID:18349501

Yang, Zhong-Bao; You, Jiang-Feng; Yang, Zhen-Ming

2007-12-01

483

Manganese in occupational arc welding fumes--aspects on physiochemical properties, with focus on solubility.  

PubMed

Physicochemical properties, such as particle sizes, composition, and solubility of welding fumes are decisive for the bioaccessibility of manganese and thereby for the manganese cytotoxic and neurotoxic effects arising from various welding fumes. Because of the diverse results within the research on welding fume solubility, this article aims to review and discuss recent literature on physicochemical properties of gas metal arc welding, shielded metal arc welding, and flux-cored arc welding fumes, with focus on solubility properties. This article also presents a short introduction to the literature on arc welding techniques, health effects from manganese, and occupational exposure to manganese among welders. PMID:22997412

Taube, Fabian

2013-01-01

484

Effects of Chronic Manganese Exposure on Cognitive and Motor Functioning in Non-Human Primates  

PubMed Central

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 15 mg/kg/week) over an exposure period lasting 272 17 days. Prior to manganese exposure, animals were trained to perform tests of cognitive and motor functioning and overall behavior was assessed by ratings and by videotaped analyses. By the end of the manganese exposure period, animals developed subtle deficits in spatial working memory and had modest decreases in spontaneous activity and manual dexterity. In addition, stereotypic or compulsive-like behaviors such as compulsive grooming increased in frequency by the end of the manganese exposure period. Blood manganese levels measured at the end of the manganese exposure period ranged from 29.4 to 73.7 ?g/L (mean = 55.7 10.8 (compared to levels of 5.114.2 ?g/L at baseline (mean = 9.2 2.7), placing them within the upper range of levels reported for human environmental, medical or occupational exposures. These results suggest that chronic exposure to levels of manganese achieved in this study may have detrimental effects on behavior, cognition and motor functioning. PMID:16978592

Schneider, Jay S.; Decamp, Emmanuel; Koser, Amy Jo; Fritz, Stephanie; Gonczi, Heather; Syversen, Tore; Guilarte, Toms R.

2007-01-01

485

Effect of Inclusions' Behavior on the Microstructure in Al-Ti Deoxidized and Magnesium-Treated Steel with Different Aluminum Contents  

NASA Astrophysics Data System (ADS)

To clarify the precipitation behavior of beneficial inclusions and mechanism of their effects on microstructure, the effect of aluminum content on inclusion's characteristics and their influence on the refinement of microstructure in Al-Ti complex deoxidized magnesium-treated steels were systematically investigated based on experiment and calculation. The results showed that due to the dual effects of Ti and Mg deoxidation, a large amount of finely dispersed Al2O3-TiO x -MgO inclusions in low aluminum steel with a complex multilayer or mosaic structure were formed, whereas a relatively smaller amount of Al2O3-MgO inclusions with the simple bundle structure were observed in high aluminum steel. The Al2O3-TiO x -MgO core oxides are more conducive to the precipitation of multiple manganese sulfides with thinner thickness on their local surfaces. Thus, the inclusion deformation, which mainly depends on the surface manganese sulfides layer, is smaller in low aluminum steel than that in high aluminum steel. Complex inclusions in low aluminum steel can pin austenite grain boundaries and induce interlocking acicular ferrite effectively. In addition to the small size and chemical composition of inclusions, the complex structure of oxides and the precipitation of multiple MnS on their surface are important to the nucleation of interlocking AFs on inclusions in Ti-deoxidized Mg-treated steel. The AFs quantity is much more, and the grain size is more uniform in low aluminum steel than that in high aluminum steel.

Wu, Zhenhua; Zheng, Wan; Li, Guangqiang; Matsuura, Hiroyuki; Tsukihashi, Fumitaka

2015-02-01

486

Characterization of aging-induced microstructural changes in M250 maraging steel using magnetic parameters  

NASA Astrophysics Data System (ADS)

The best combinations of mechanical properties (yield stress and fracture toughness) of M250 maraging steel is obtained through short-term thermal aging (3-10 h) at 755 K. This is attributed to the microstructure containing precipitation of intermetallic phases in austenite-free low-carbon martensite matrix. Over-aged microstructure, containing reverted austenite degrades the mechanical properties drastically. Hence, it necessitates identification of a suitable non-destructive evaluation (NDE) technique for detecting any reverted austenite unambiguously during aging. The influence of aging on microstructure, room temperature hardness and non-destructive magnetic parameters such as coercivity ( Hc), saturation magnetization ( Ms) and magnetic Barkhausen emission (MBE) RMS peak voltage is studied in order to derive correlations between these parameters in aged M250 maraging steel. Hardness was found to increase with precipitation of intermetallics during initial aging and decrease at longer durations due to austenite reversion. Among the different magnetic parameters studied, MBE RMS peak voltage was found to be very sensitive to austenite reversion (non-magnetic phase) as they decreased drastically up on initiation of austenite reversion. Hence, this parameter can be effectively utilized to detect and quantify the reverted austenite in maraging steel specimen. The present study clearly indicates that the combination of MBE RMS peak voltage and hardness can be used for unambiguous characterization of microstructural features of technological and practical importance (3-10 h of aging duration at 755 K) in M250 grade maraging steel.

Rajkumar, K. V.; Vaidyanathan, S.; Kumar, Anish; Jayakumar, T.; Raj, Baldev; Ray, K. K.

2007-05-01

487

Mechanisms of hydrogen sulfide removal with steel making slag.  

PubMed

In the present study, we experimentally investigated the removal of hydrogen sulfide using steel-making slag (SMS) and clarified the mechanism of hydrogen sulfide removal with the SMS. The results proved that SMS is able to remove hydrogen sulfide dissolved in water, and the maximum removal amount of hydrogen sulfide per unit weight of the SMS for 8 days was estimated to be 37.5 mg S/g. The removal processes of hydrogen sulfide were not only adsorption onto the SMS, but oxidation and precipitation as sulfur. The chemical forms of sulfide adsorbed onto the SMS were estimated to be sulfur and manganese sulfide in the ratio of 81% and 19%, respectively. It is demonstrated here that the SMS is a promising material to remediate organically enriched coastal sediments in terms of removal of hydrogen sulfide. Furthermore, using SMS is expected to contribute to development of a recycling-oriented society. PMID:22894171

Kim, Kyunghoi; Asaoka, Satoshi; Yamamoto, Tamiji; Hayakawa, Shinjiro; Takeda, Kazuhiko; Katayama, Misaki; Onoue, Takasumi

2012-09-18

488

Iron and manganese oxide mineralization in the Pacific  

USGS Publications Warehouse

Iron, manganese, and iron-manganese deposits occur in nearly all geomorphologic and tectonic environments in the ocean basins and form by one or more of four processes: (1) hydrogenetic precipitation from cold ambient seawater, (2) precipitation from hydrothermal fluids, (3) precipitation from sediment pore waters that have been modified from bottom water compositions by diagenetic reactions in the sediment column and (4) replacement of rocks and sediment. Iron and manganese deposits occur in five forms: nodules, crusts, cements, mounds and sediment-hosted stratabound layers. Seafloor oxides show a wide range of compositions from nearly pure iron to nearly pure manganese end members. Fe/Mn ratios vary from about 24 000 (up to 58% elemental Fe) for hydrothermal seamount ironstones to about 0.001 (up to 52% Mn) for hydrothermal stratabound manganese oxides from active volcanic arcs. Hydrogenetic Fe-Mn crusts that occur on most seamounts in the ocean basins have a mean Fe/Mn ratio of 0.7 for open-ocean seamount crusts and 1.2 for continental margin seamount crusts. Fe-Mn nodules of potential economic interest from the Clarion-Clipperton Zone have a mean Fe/Mn ratio of 0.3, whereas the mean ratio for nodules from elsewhere in the Pacific is about 0.7. Crusts are enriched in Co, Ni and Pt and nodules in Cu and Ni, and both have significant concentrations of Pb, Zn, Ba, Mo, V and other elements. In contrast, hydrothermal deposits commonly contain only minor trace metal contents, although there are many exceptions, for example, with Ni contents up to 0.66%, Cr to 1.2%, and Zn to 1.4%. Chondrite-normalized REE patterns generally show a positive Ce anomaly and abundant ??REEs for hydrogenetic and mixed hydrogenetic-diagenetic deposits, whereas the Ce anomaly is negative for hydrothermal deposits and ??REE contents are low. However, the Ce anomaly in crusts may vary from strongly positive in East Pacific crusts to slightly negative in West Pacific crusts, which may reflect the redox conditions of seawater. The concentration of elements in hydrogenetic Fe-Mn crusts depends on a wide variety of water column and crust surface characteristics, whereas concentration of elements in hydrothermal oxide deposits depends of the intensity of leaching, rock types leached, and precipitation of sulphides at depth in the hydrothermal system.

Hein, J.R.; Koschinsky, A.; Halbach, P.; Manheim, F. T.; Bau, M.; Kang, J.-K.; Lubick, N.

1997-01-01

489

Mechanisms of inclusion formation in Al-Ti-Si-Mn deoxidized steel weld metals  

NASA Astrophysics Data System (ADS)

The present investigation is concerned with basic studies of the mechanisms of inclusion formation in submerged arc (SA), gas metal arc (GMA), and flux cored arc (FCA) steel weld metals. Theoretical models of deoxidation have been developed to establish a basis for quantitative predictions of important inclusion characteristics, such as volume fraction, size, and chemical composition from knowledge of weld metal chemistry and operating parameters. The relevance of these models has been tested against extensive inclusion data obtained from scanning electron microscope (SEM) and scanning transmission electron microscope (STEM) examinations of a large number of experimental welds containing various contents of aluminum, titanium, silicon, manganese, and oxygen.

Kluken, A. O.; Grong, .

1989-08-01