Development of a method for determination of metallic iron content within hot briquette iron (HBI for steelmaking

Directory of Open Access Journals (Sweden)

Morcali M.H.

2016-01-01

Full Text Available The growing use of metallic iron in metallurgy and industrial chemical applications requires a fast, easy and cheap method for the determination of metallic iron, not merely in recyclable materials, such as iron pellets, reduced iron mill scale dust, electric arc furnace dust and pig iron, but from hot briquette iron (HBI as well. This study investigates a new method for determination of metallic iron within HBI used for steel-making materials. The effects of reaction time, temperature, and stirring rate were studied. The concentration of iron was determined via Atomic Absorption Spectroscopy (AAS. After the optimization study, high-purity metallic iron powder (Sigma-Aldrich, PubChem Substance ID 24855469 was used to compare efficiencies and identify the optimum conditions; The present study was matched with international standard methods (BS ISO 5416:2006, IS 15774:2007. Results were consistent with certified values and metallic iron content could be determined within the 95% confidence level. The purposed method is easy, straightforward, and cheap.

Regeneration of iron oxide containing pellets used for hot gas clean up

Energy Technology Data Exchange (ETDEWEB)

Palmer, A.; Heeney, P.; Furimsky, E. (CANMET, Ottawa, Ontario (Canada). Energy Research Laboratories)

1989-09-01

Four iron-containing pelletized solids used for H{sub 2}S removal from hot gas were oxidized in a Cahn electrobalance and in a fixed bed reactor. The main reactions included the sequence in which FeS was oxidized to iron sulphate which then decomposed rapidly yielding SO{sub 2} and iron oxides. The oxidation occurred predominantly on the outer surface of the pellets. 12 refs., 5 figs., 5 tabs.

Hereditary iron and copper deposition

DEFF Research Database (Denmark)

Aaseth, Jan; Flaten, Trond Peder; Andersen, Ole

2007-01-01

Hereditary deposition of iron (primary haemochromatosis) or copper (Wilson's disease) are autosomal recessive metabolic disease characterized by progressive liver pathology and subsequent involvement of various other organs. The prevalence of primary haemochromatosis is approximately 0.5%, about......, they may be inadequate in patients diagnosed so late that extensive body deposits of metal have been developed. The main research needs in this field are to further clarify molecular mechanisms of disease progression and to develop new chelators that are more effective and less toxic than those presently...

The role of catalytic nanoparticle pretreatment on the growth of vertically aligned carbon nanotubes by hot-filament chemical vapor deposition

Energy Technology Data Exchange (ETDEWEB)

Kim, Ki-Hwan; Gohier, Aurélien; Bourée, Jean Eric; Châtelet, Marc; Cojocaru, Costel-Sorin, E-mail: costel-sorin.cojocaru@polytechnique.edu

2015-01-30

The effect of atomic hydrogen assisted pre-treatment on the growth of vertically aligned carbon nanotubes using hot-filament chemical vapor deposition was investigated. Iron nanoparticle catalysts were formed on an aluminum oxide support layer by spraying of iron chloride salt solutions as catalyst precursor. It is found that pre-treatment time and process temperature tune the density as well as the shape and the structure of the grown carbon nanotubes. An optimum pre-treatment time can be found for the growth of long and well aligned carbon nanotubes, densely packed to each other. To provide insight on this behavior, the iron catalytic nanoparticles formed after the atomic hydrogen assisted pre-treatment were analyzed by atomic force microscopy. The relations between the size and the density of the as-formed catalyst and the as-grown carbon nanotube's structure and density are discussed. - Highlights: • Effect of the atomic hydrogen assisted pre-treatment on the growth of VACNT using hot-filament CVD. • Pre-treatment time and process temperature tune the density, the shape and the structure of the CNTs. • Correlations between size and density of the as-formed catalyst and the CNT’s structure and density. • Carbon nanotubes synthesized at low temperature down to 500 °C using spayed iron chloride salts. • Density of the CNT carpet adjusted by catalytic nanoparticle engineering.

Bismuth iron oxide thin films using atomic layer deposition of alternating bismuth oxide and iron oxide layers

Energy Technology Data Exchange (ETDEWEB)

Puttaswamy, Manjunath; Vehkamäki, Marko [University of Helsinki, Department of Chemistry, P.O. Box 55, FI-00014 Helsinki (Finland); Kukli, Kaupo, E-mail: kaupo.kukli@helsinki.fi [University of Helsinki, Department of Chemistry, P.O. Box 55, FI-00014 Helsinki (Finland); University of Tartu, Institute of Physics, W. Ostwald 1, EE-50411 Tartu (Estonia); Dimri, Mukesh Chandra [National Institute of Chemical Physics and Biophysics, Akadeemia tee 23, EE-12618 Tallinn (Estonia); Kemell, Marianna; Hatanpää, Timo; Heikkilä, Mikko J. [University of Helsinki, Department of Chemistry, P.O. Box 55, FI-00014 Helsinki (Finland); Mizohata, Kenichiro [University of Helsinki, Department of Physics, P.O. Box 64, FI-00014 Helsinki (Finland); Stern, Raivo [National Institute of Chemical Physics and Biophysics, Akadeemia tee 23, EE-12618 Tallinn (Estonia); Ritala, Mikko; Leskelä, Markku [University of Helsinki, Department of Chemistry, P.O. Box 55, FI-00014 Helsinki (Finland)

2016-07-29

Bismuth iron oxide films with varying contributions from Fe{sub 2}O{sub 3} or Bi{sub 2}O{sub 3} were prepared using atomic layer deposition. Bismuth (III) 2,3-dimethyl-2-butoxide, was used as the bismuth source, iron(III) tert-butoxide as the iron source and water vapor as the oxygen source. The films were deposited as stacks of alternate Bi{sub 2}O{sub 3} and Fe{sub 2}O{sub 3} layers. Films grown at 140 °C to the thickness of 200–220 nm were amorphous, but crystallized upon post-deposition annealing at 500 °C in nitrogen. Annealing of films with intermittent bismuth and iron oxide layers grown to different thicknesses influenced their surface morphology, crystal structure, composition, electrical and magnetic properties. Implications of multiferroic performance were recognized in the films with the remanent charge polarization varying from 1 to 5 μC/cm{sup 2} and magnetic coercivity varying from a few up to 8000 A/m. - Highlights: • Bismuth iron oxide thin films were grown by atomic layer deposition at 140 °C. • The major phase formed in the films upon annealing at 500 °C was BiFeO{sub 3}. • BiFeO{sub 3} films and films containing excess Bi favored electrical charge polarization. • Slight excess of iron oxide enhanced saturative magnetization behavior.

Magnetic and gravity gradiometry framework for Mesoproterozoic iron oxide-apatite and iron oxide-copper-gold deposits, southeast Missouri, USA

Science.gov (United States)

McCafferty, Anne E.; Phillips, Jeffrey; Driscoll, Rhonda L.

2016-01-01

High-resolution airborne magnetic and gravity gradiometry data provide the geophysical framework for evaluating the exploration potential of hidden iron oxide deposits in Mesoproterozoic basement rocks of southeast Missouri. The data are used to calculate mineral prospectivity for iron oxide-apatite (IOA) ± rare earth element (REE) and iron oxide-copper-gold (IOCG) deposits. Results delineate the geophysical footprints of all known iron oxide deposits and reveal several previously unrecognized prospective areas. The airborne data are also inverted to three-dimensional density and magnetic susceptibility models over four concealed deposits at Pea Ridge (IOA ± REE), Boss (IOCG), Kratz Spring (IOA), and Bourbon (IOCG). The Pea Ridge susceptibility model shows a magnetic source that is vertically extensive and traceable to a depth of greater than 2 km. A smaller density source, located within the shallow Precambrian basement, is partly coincident with the magnetic source at Pea Ridge. In contrast, the Boss models show a large (625-m-wide), vertically extensive, and coincident dense and magnetic stock with shallower adjacent lobes that extend more than 2,600 m across the shallow Precambrian paleosurface. The Kratz Spring deposit appears to be a smaller volume of iron oxides and is characterized by lower density and less magnetic rock compared to the other iron deposits. A prospective area identified south of the Kratz Spring deposit shows the largest volume of coincident dense and nonmagnetic rock in the subsurface, and is interpreted as prospective for a hematite-dominant lithology that extends from the top of the Precambrian to depths exceeding 2 km. The Bourbon deposit displays a large bowl-shaped volume of coincident high density and high-magnetic susceptibility rock, and a geometry that suggests the iron mineralization is vertically restricted to the upper parts of the Precambrian basement. In order to underpin the evaluation of the prospectivity and three

Analysis of graphite dust deposition in hot gas duct of HTGR

International Nuclear Information System (INIS)

Peng Wei; Zhen Ya'nan; Yang Xiaoyong; Ye Ping

2013-01-01

The behavior of the graphite dust is important to the safety of high-temperature gas-cooled reactor (HTGR). The temperature field in hot gas duct was obtained using computational fluid dynamics (CFD) method. Further analysis to the thermo-phoretic deposition and turbulent deposition shows that as the dust particle diameter increases, the thermo-phoretic deposition efficiency decreases, and the turbulent deposition efficiency initially decreases and then increases. The comparisons of calculation results for two reactor powers, namely 30% FP (full power) and 100 % FP, indicate that the thermo-phoretic deposition efficiency is higher at 30% FP than that at 100% FP. while the turbulent deposition efficiency grows more rapidly at 100% FP. Besides, the results also demonstrate that the thermo-phoretic deposition and the turbulent deposition are nearly equivalent when particle sizes are small, while the turbulent deposition becomes dominant when particle sizes are fairly large. The calculation results by using the most probable distribution of particle size show that the total deposition of graphite dusts in hot gas duct is limited. (authors)

Enhanced energy deposition symmetry by hot electron transport

International Nuclear Information System (INIS)

Wilson, D.; Mack, J.; Stover, E.; VanHulsteyn, D.; McCall, G.; Hauer, A.

1981-01-01

High energy electrons produced by resonance absorption carry the CO 2 laser energy absorbed in a laser fusion pellet. The symmetrization that can be achieved by lateral transport of the hot electrons as they deposit their energy is discussed. A K/sub α/ experiment shows a surprising symmetrization of energy deposition achieved by adding a thin layer of plastic to a copper sphere. Efforts to numerically model this effect are described

Iron and manganese deposits in Uruguay

International Nuclear Information System (INIS)

Alvarado, B.

1959-01-01

This report is the results of the study carried out for the United Nations expert which the main object was: the study of the information available about iron and manganese formation in Uruguay, as well as the main researching deposit to determinate economical possibilities in the exportation.

Non cardiopatic and cardiopatic beta thalassaemic patients: quantitative and qualitative cardiac iron deposition evaluation with MRI

International Nuclear Information System (INIS)

Macarini, Luca; Marini, Stefania; Scardapane, Arnaldo; Pietrapertosa, Anna; Ettore, Giovanni Carlo

2005-01-01

Purpose: Cardiomyopathy is one of the major complications of β thalassaemia major as a result of transfusion iron overload. The aim of our study is to evaluate with MR if there is any difference of iron deposition signal intensity (SI) or distribution between non-cardiopatic and cardiopatic thalassaemic patients in order to establish if there is a relationship between cardiopathy and iron deposition. Materials and methods: We studied 20 patients affected by β thalassaemia major, of whom 10 cardiopatic and 10 non-cardiopatic, and 10 healthy volunteers as control group. Serum ferritin and left ventricular ejection fraction were calculated in thalassaemic patients. All patients were examinated using a 1.5 MR unit with ECG-gated GE cine-MR T2*-weighted, SE T1-weighted and GE T2*-weighted sequences. In all cases, using an adequate ROI, the myocardial and skeletal muscle signal intensity (SI), the myocardial/skeletal muscle signal intensity radio (SIR) and the SI average of the myocardium and skeletal muscle were calculated for every study group. The qualitative evaluation of iron deposition distribution was independently performed by three radiologists who analysed the extension, the site and the morphology of iron deposition on the MR images and reported their observations on the basis of a four-level rating scale: 0 (absent), 1 (limited), 2 (partial), 3 (widespread deposition). The results of quantitative and qualitative evaluation were analysed with statistical tests. Results: Cardiac iron deposition was found in 8/10 non-cardiopatic thalassaemic patients and in all cardiopatic thalassaemic patients. We noticed a significant SI difference (p>0.05) between the healthy volunteer control group and the thalassaemic patients with iron deposition, but no significant SI difference in iron deposition between non-cardiopatic thalassaemic patients in the areas evaluated. The qualitative evaluation revealed a different distribution of iron deposition between the two

MRI in haemochromatosis: pituitary versus testicular iron deposition in five patients with hypogonadism

International Nuclear Information System (INIS)

Miaux, Y.; Daurelle, P.; Zagdanski, A.M.; Passa, P.; Bourrier, P.; Frija, J.

1995-01-01

Haemochromatosis is a disease characterised by iron deposition in the liver and other organs. Hypogonadism is a commonly associated condition and may be either primary due to testicular lesions or secondary due to pituitary dysfunction. Hypogonadism secondary to pituitary dysfunction is more frequent and is thought to be related to iron deposition in the anterior pituitary. Increased iron content decreases signal intensity of spin-echo MRI images because T2 values are significantly shortened. Our purpose in this study was to evaluate by MRI iron deposition in the liver, testis and pituitary of 6 patients with haemochromatosis and severe hypogonadotrophic hypogonadism. Six subjects served as controls. There was a significant T2 shortening of the liver and pituitary in patients with haemochromatosis compared with control patients. Therefore MRI detected iron overload in the pituitary and no iron in the testis, supporting the hypothesis of hypogonadotrophic pituitary insufficiency due to cellular damage induced by iron overload in the anterior pituitary gland. (orig.)

Developments in hot-filament metal oxide deposition (HFMOD)

International Nuclear Information System (INIS)

Durrant, Steven F.; Trasferetti, Benedito C.; Scarminio, Jair; Davanzo, Celso U.; Rouxinol, Francisco P.M.; Gelamo, Rogerio V.; Bica de Moraes, Mario A.

2008-01-01

Hot-filament metal oxide deposition (HFMOD) is a variant of conventional hot-filament chemical vapor deposition (HFCVD) recently developed in our laboratory and successfully used to obtain high-quality, uniform films of MO x , WO x and VO x . The method employs the controlled oxidation of a filament of a transition metal heated to 1000 deg. C or more in a rarefied oxygen atmosphere (typically, of about 1 Pa). Metal oxide vapor formed on the surface of the filament is transported a few centimetres to deposit on a suitable substrate. Key system parameters include the choice of filament material and diameter, the applied current and the partial pressures of oxygen in the chamber. Relatively high film deposition rates, such as 31 nm min -1 for MoO x , are obtained. The film stoichiometry depends on the exact deposition conditions. MoO x films, for example, present a mixture of MoO 2 and MoO 3 phases, as revealed by XPS. As determined by Li + intercalation using an electrochemical cell, these films also show a colouration efficiency of 19.5 cm 2 C -1 at a wavelength of 700 nm. MO x and WO x films are promising in applications involving electrochromism and characteristics of their colouring/bleaching cycles are presented. The chemical composition and structure of VO x films examined using IRRAS (infrared reflection-absorption spectroscopy), RBS (Rutherford backscattering spectrometry) and XPS (X-ray photoelectron spectrometry) are also presented

Iron deposition in modern and archaeological teeth

Energy Technology Data Exchange (ETDEWEB)

Williams, A.-M.M., E-mail: AnneMarie.Williams@utas.edu.au [School of Medicine, Private Bag 34, University of Tasmania, Hobart 7001 (Australia); Siegele, R. [Australian Nuclear Science and Technology Organisation, PMB 1, Menai, NSW 2234 (Australia)

2014-09-15

Iron surface concentrations and profile maps were measured on the enamel of archaeological and modern teeth to determine how iron is deposited in tooth enamel and if it was affected by the post-mortem environment. Teeth from Australian children who died in the second half of the 19th century were compared with contemporary teeth extracted for orthodontic purposes. Surface analysis of the teeth was performed using the 3 MV Van Der Graff Accelerator at The Australian Nuclear Science and Technology Organisation (ANSTO), Sydney, Australia. A small sample of teeth were then cut in the mid sagittal plane and analysed using ANSTO High Energy Heavy Ion Microprobe. Maps and linear profiles were produced showing the distribution of iron across the enamel. Results show that both the levels and distribution of iron in archaeological teeth is quite different to contemporary teeth, raising the suggestion that iron has been significantly altered by the post-mortem environment.

Iron deposition in modern and archaeological teeth

International Nuclear Information System (INIS)

Williams, A.-M.M.; Siegele, R.

2014-01-01

Iron surface concentrations and profile maps were measured on the enamel of archaeological and modern teeth to determine how iron is deposited in tooth enamel and if it was affected by the post-mortem environment. Teeth from Australian children who died in the second half of the 19th century were compared with contemporary teeth extracted for orthodontic purposes. Surface analysis of the teeth was performed using the 3 MV Van Der Graff Accelerator at The Australian Nuclear Science and Technology Organisation (ANSTO), Sydney, Australia. A small sample of teeth were then cut in the mid sagittal plane and analysed using ANSTO High Energy Heavy Ion Microprobe. Maps and linear profiles were produced showing the distribution of iron across the enamel. Results show that both the levels and distribution of iron in archaeological teeth is quite different to contemporary teeth, raising the suggestion that iron has been significantly altered by the post-mortem environment

Mineralogical study of zard koh and kulli koh iron ore deposits of pakistan

International Nuclear Information System (INIS)

Khoso, S.A.; Abro, M.I.

2017-01-01

Zard Koh and Kulli Koh are two recently discovered iron ore deposits, existing in the Chagai district, Balochistan, Pakistan. PSM (Pakistan Steel Mill Limited) is interested to utilize these ore deposits at priority. Purpose of the present study was to assess the mineralogy of the Zard Koh and Kulli Koh iron ore deposits, as it plays a vital role in the selection of an appropriate processing method. The mineralogical study of ore deposits was carried out by XRD (X-Ray Diffraction), XRF (X-Ray Fluorescence), SEM (Scanning Electron Microscope) attached with EDS (Energy Dispersive Spectroscope) and SM (Stereomicroscope) techniques. Results indicated that the Zard Koh ore is mainly composed of 60.15% maghemite, 23.57% pyrite, 4.07% chlorite, 10.30% grossular and 1.65% admontite minerals. The chemical analysis revealed that Zard Koh iron ore contains an average of 54.27% Fe, 12.73% S, 8.70% Si, 3.07% Al, 4.07% Ca, and 2.16% Mg. Similarly, the mineralogical study of the Kulli Koh iron ore indicated that, ore is containing 51.16% hematite, 29.24% quartz, 8.89% dravite, and 8.76% kaolinite minerals. Elemental analysis of different samples indicated that Kulli Koh iron ore contains an average composition of 40.23% Fe, 20.67% Si, 3.44% Ca, 3.81% Al and 3.25% Mg. Mineralogical study of the Zard Koh and Kulli Koh iron ore deposits suggested that these ore deposits can be beneficiated costeffectively by using magnetic separation techniques. (author)

Iron Deposition and Ferritin Heavy Chain (Fth Localization in Rodent Teeth

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Wen Xin

2013-01-01

Full Text Available Abstract Background An iron rich layer on the labial surface is characteristic of the enamel of rodent incisors. In order to address a role for iron content in continuously growing incisors during odontogenesis, we studied iron deposition patterns in enamel and dentine using Perls’ blue staining and ferritin heavy chain (Fth immunolocalization. Fth expression is regulated by iron level; therefore its localization can be used as a sensitive indicator for iron deposition. Results Sagittal sections of 4-week old rat incisors showed a gradual increase in iron level in the enamel organ from secretory to maturation stages. In addition, iron was detected in ameloblasts of erupting third molars of 4-week old rats, suggesting iron plays a role in both incisor and molar development. In odontoblasts, the presence of iron was demonstrated, and this is consistent with iron’s role in collagen synthesis. Using postnatal 3-, 6-, 9-day old mice, the spatial and temporal expression of Fth in tooth development again indicated the presence of iron in mature ameloblasts and odontoblasts. Conclusions While these data do not explain what functional role iron has in tooth formation, it does highlight a significant molecular activity associated with the formation of the rodent dentition.

Cast iron as structural material for hot-working reactor vessels (PCIV)

International Nuclear Information System (INIS)

Ostendorf, H.; Schmidt, G.; Pittack, W.

1977-01-01

Cast iron with lamellar graphite is best suited for prestressed structures, because its compressive strength is nearly 4 times its tensile strength. In comparison to room temperature, cast iron with lamellar graphite shows essentially no loss of strength up to temperatures of 400 0 C. Under the particular aspect to use cast iron for hot-working prestressed reactor pressure vessels (PCIV) (Prestressed cast iron vessel=PCIV) a materials testing program is carried out, which meets the strict certification requirements for materials in the construction of reactor pressure vessels and which completes the presently available knowledge of cast iron. Especially in the following fields an extension and supplement of the present level of knowledge is necessary. - Mechanical properties under compressive stresses. - Material properties at elevated temperatures. - Influence of irradiation on mechanical and physical properties. - Production standards and quality control. The state of the research and the available data of the material testing program are reported. (Auth.)

Cast iron as structural material for hot-working reactor vessels (PCIV)

International Nuclear Information System (INIS)

Ostendorf, H.; Schmidt, G.; Pittack, W.

1977-01-01

Cast iron with lamellar graphite is best suited for prestressed structures, because its compressive strength is nearly 4 times its tensile strength. In comparison to room temperature, cast iron with lamellar graphite shows essentially no loss of strength up to temperatures of 400 0 C. Under the particular aspect to use cast iron for hot-working prestressed reactor pressure vessels (PCIV) (Prestressed cast iron vessel=PCIV) a materials testing program is carried out, which meets the strict certification requirements for materials in the construction of reactor pressure vessels and which completes the presently available knowledge of cast iron. Especially in the following fields an extension and supplement of the present level of knowledge is necessary: mechanical properties under compressive stresses; material properties at elevated temperatures; influence of irradiation on mechanical and physical properties; production standards and quality control. The state of the research and the available data of the material testing program are reported

Formation of microstructure and properties on hot working and heat treatment of high strength modular cast iron

International Nuclear Information System (INIS)

Trajno, A.I.; Yusupov, V.S.; Kugushin, A.A.

1999-01-01

The possibility of plastic deformation of high strength modular cast iron (HSNCI) is under study. The microstructure and mechanical properties of hot worked and heat treated cast iron are investigated for the composition, %: Fe - 2.9 C - 2.4 Si - 0.7 Ni - 0.05 Mg - 0.04 Ce. It is stated that HSNCI can withstand various types of hot working without fracturing. Graphite inclusions lose their modular shape irreversibly during plastic deformation. Subsequent heat treatment affects the metal matrix only. The heating in oxidizing environment is noted to result in cast iron surface decarbonization [ru

Developments in hot-filament metal oxide deposition (HFMOD)

Energy Technology Data Exchange (ETDEWEB)

Durrant, Steven F. [Laboratorio de Plasmas Tecnologicos, Campus Experimental de Sorocaba, Universidade Estadual Paulista (UNESP), Avenida Tres de Marco, 511, Alto de Boa Vista, 18087-180 Sorocaba, SP (Brazil)], E-mail: steve@sorocaba.unesp.br; Trasferetti, Benedito C. [Departamento de Policia Federal, Superintendencia Regional no Piaui, Setor Tecnico-Cientifico, Avenida Maranhao, 1022/N, 64.000-010, Teresina, PI (Brazil); Scarminio, Jair [Departamento de Fisica, Universidade Estadual de Londrina (UEL), 86051-990, Londrina, PR (Brazil); Davanzo, Celso U. [Instituto de Quimica, Universidade Estadual de Campinas (UNICAMP), 13083-970, Campinas, SP (Brazil); Rouxinol, Francisco P.M.; Gelamo, Rogerio V.; Bica de Moraes, Mario A. [Laboratorio de Processos de Plasma, Departamento de Fisica Aplicada, Instituto de Fisica Gleb Wataghin, Universidade Estadual de Campinas (UNICAMP), 13083-970, Campinas, SP (Brazil)

2008-01-15

Hot-filament metal oxide deposition (HFMOD) is a variant of conventional hot-filament chemical vapor deposition (HFCVD) recently developed in our laboratory and successfully used to obtain high-quality, uniform films of MO{sub x}, WO{sub x} and VO{sub x}. The method employs the controlled oxidation of a filament of a transition metal heated to 1000 deg. C or more in a rarefied oxygen atmosphere (typically, of about 1 Pa). Metal oxide vapor formed on the surface of the filament is transported a few centimetres to deposit on a suitable substrate. Key system parameters include the choice of filament material and diameter, the applied current and the partial pressures of oxygen in the chamber. Relatively high film deposition rates, such as 31 nm min{sup -1} for MoO{sub x}, are obtained. The film stoichiometry depends on the exact deposition conditions. MoO{sub x} films, for example, present a mixture of MoO{sub 2} and MoO{sub 3} phases, as revealed by XPS. As determined by Li{sup +} intercalation using an electrochemical cell, these films also show a colouration efficiency of 19.5 cm{sup 2} C{sup -1} at a wavelength of 700 nm. MO{sub x} and WO{sub x} films are promising in applications involving electrochromism and characteristics of their colouring/bleaching cycles are presented. The chemical composition and structure of VO{sub x} films examined using IRRAS (infrared reflection-absorption spectroscopy), RBS (Rutherford backscattering spectrometry) and XPS (X-ray photoelectron spectrometry) are also presented.

Mineralogical Study of Zard Koh and Kulli Koh Iron Ore Deposits of Pakistan

Directory of Open Access Journals (Sweden)

SULTAN AHMED KHOSO

2017-10-01

Full Text Available Zard Koh and Kulli Koh are two recently discovered iron ore deposits, existing in the Chagai district, Balochistan, Pakistan. PSM (Pakistan Steel Mill Limited is interested to utilize these ore deposits at priority. Purpose of the present study was to assess the mineralogy of the Zard Koh and Kulli Koh iron ore deposits, as it plays a vital role in the selection of an appropriate processing method. The mineralogical study of ore deposits was carried out by XRD (X-Ray Diffraction, XRF (X-Ray Fluorescence, SEM (Scanning Electron Microscope attached with EDS (Energy Dispersive Spectroscope and SM (Stereomicroscope techniques. Results indicated that the Zard Koh ore is mainly composed of 60.15% maghemite, 23.57% pyrite, 4.07% chlorite, 10.30% grossular and 1.65% admontite minerals. The chemical analysis revealed that Zard Koh iron ore contains an average of 54.27% Fe, 12.73% S, 8.70% Si, 3.07% Al, 4.07% Ca, and 2.16% Mg. Similarly, the mineralogical study of the Kulli Koh iron ore indicated that, ore is containing 51.16% hematite, 29.24% quartz, 8.89% dravite, and 8.76% kaolinite minerals. Elemental analysis of different samples indicated that Kulli Koh iron ore contains an average composition of 40.23% Fe, 20.67% Si, 3.44% Ca, 3.81% Al and 3.25% Mg. Mineralogical study of the Zard Koh and Kulli Koh iron ore deposits suggested that these ore deposits can be beneficiated costeffectively by using magnetic separation techniques.

How deposition parameters control growth dynamics of nc-Si deposited by hot-wire chemical vapor deposition

International Nuclear Information System (INIS)

Moutinho, H.R.; To, B.; Jiang, C.-S.; Xu, Y.; Nelson, B.P.; Teplin, C.W.; Jones, K.M.; Perkins, J.; Al-Jassim, M.M.

2006-01-01

We studied the growth of silicon films deposited by hot-wire chemical vapor deposition under different values of filament current, substrate temperature, and hydrogen dilution ratio. The physical and electrical properties of the films were studied by Raman spectroscopy, x-ray diffraction, atomic force microscopy, conductive-atomic force microscopy, and transmission electron microscopy. There is an interdependence of the growth parameters, and films grown with different parameters can have similar structures. We discuss why this interdependence occurs and how it influences the properties of the deposited films, as well as the deposition rate. In general, the films have a complex structure, with a mixture of amorphous (220)-oriented crystalline and nanocrystalline phases present in most cases. The amount of each phase can be controlled by the variation of one or more of the growth parameters at a time

Chemical vapor deposition of aluminide coatings on iron, nickel and superalloys

International Nuclear Information System (INIS)

John, John T.; De, P.K.; Dubey, Vivekanand; Srinivasa, Raman

2009-08-01

Aluminide coatings are a class of intermetallic coatings applied on nickel and cobalt base superalloys and steels to protect them from different forms of environmental degradation at high temperatures. In this report a CVD system that can produce the aluminide coatings on iron, nickel and nickel base alloys has been described and the result of chemical vapor deposition of aluminide coatings on iron specimens, their characterization, and property evaluation have been presented. The CVD system consists of an AlCl 3 bath, a stainless steel retort as a hot-wall reacto, cold traps and vacuum system. Aluminium chloride vapor was carried in a stream of hydrogen gas at a flow rate of 150 SCCM (standard cubic centimeter per minute) into the CVD reactor maintained in the temperature range of 1173 - 1373 K and at a pressure of 1.33 kPa (10 Torr). Aluminum deposition takes place from aluminium subchlorides produced by reaction between AlCl 3 and pure aluminum kept in the CVD reactor. The aluminum diffuses into the iron samples and iron aluminide phases are formed at the surface. The coatings were shining bright and showed good adherence to the substrate. The coatings consisted of FeAl phase over a wide range of experimental conditions. The growth kinetics of the coating followed a parabolic rate law and the mean activation energy was 212 ±16 kJ/mol. Optical microscopic studies on the transverse section of the coating showed that the aluminide coating on iron consisted of two layers. The top layer had a thickness in the range of 20-50 μm, and the under layer had thickness ranging from 35 to 250 μm depending on coating temperature in two hours. The thickness of the aluminide layer increased with coating duration and temperature. Electron microprobe studies (EPMA) showed that the aluminum concentration decreased steadily as distance from the surface increased. TEM studies showed that the outer most layer had a B2 order (of the FeAl phase), which extended even into the under

Methods of preparing deposits containing iron oxides for recycling

Directory of Open Access Journals (Sweden)

T. Lis

2013-04-01

Full Text Available The metallurgical industry is one of the largest sources of wastes. Some of them, however, owing to their content of metals such as zinc or iron, may become valuable secondary raw materials. In order to achieve that purpose, they require appropriate preparation. This article provides a discussion on the methods of preparation of scrap from steelworks, namely deposits containing iron oxides, enabling their recycling.

Change in color of the hot spring deposits at the Chinoike-Jigoku hot pool, Beppu geothermal field

Energy Technology Data Exchange (ETDEWEB)

Kazuthoshi, Oue; Ohsawa, Shinji; Yusa, Yuki [Kyoto University, Beppu (Japan). Beppu Geothermal Research Laboratory, Graduate School of Science

2002-06-01

The Chinoike-Jigoku hot pool in Beppu geothermal field, Central Kyushu, Japan, displays a blood-red color due to the hematite (Fe{sub 2}O{sub 3}) deposited at the bottom of the pool. The colors of the deposits collected on 1 October 1990, on 27 March 1995, and on 6 March 1996 were measured with a colorimeter. The results show that the red deposits became yellower in 1995 and 1996 than they were in 1990. X-ray diffraction (XRD) patterns and chemical compositions of the deposits indicate that the discoloration of the Chinoike-Jigoku pool water is caused by an increase in the content of jarosite [KFe{sub 3}(SO{sub 4}){sub 2}(OH){sub 6}]. The temperature of the subsurface thermal water beneath the Chinoike-Jigoku hot pool, as estimated by the anhydrite chemical geothermometer, has declined from 200 to 150{sup o}C over the past 25 years. The Na and Cl concentrations of the hot spring water discharging from Chinoike-Jigoku have decreased, while the SO{sub 4} concentration has increased. The temporal variations in subsurface temperature and dissolved ion concentrations suggest that the mixing ratio between the high-temperature, neutral Na-Cl type water and the relatively low-temperature, acid H-SO{sub 4} type water that form the thermal water of Chinoike-Jigoku has changed over the last 25 years. Hydrothermal studies of jarosite stability have confirmed that the increase in jarosite content in the deposits was caused by a temperature drop of the mixed thermal water beneath Chinoike-Jigoku pool, due to an increase in the contribution of the cooler H-SO{sub 4} water type to the thermal mixture. (author)

Cyclic Oxidation and Hot Corrosion Behavior of Nickel-Iron-Based Superalloy

Science.gov (United States)

Chellaganesh, D.; Adam Khan, M.; Winowlin Jappes, J. T.; Sathiyanarayanan, S.

2018-01-01

The high temperature oxidation and hot corrosion behavior of nickel-iron-based superalloy are studied at 900 ° and 1000 °C. The significant role of alloying elements with respect to the exposed medium is studied in detail. The mass change per unit area was catastrophic for the samples exposed at 1000 °C and gradual increase in mass change was observed at 900 °C for both the environments. The exposed samples were further investigated with SEM, EDS and XRD analysis to study the metallurgical characteristics. The surface morphology has expressed the in situ nature of the alloy and its affinity toward the environment. The EDS and XRD analysis has evidently proved the presence of protective oxides formation on prolonged exposure at elevated temperature. The predominant oxide formed during the exposure at high temperature has a major contribution toward the protection of the samples. The nickel-iron-based superalloy is less prone to oxidation and hot corrosion when compared to the existing alloy in gas turbine engine simulating marine environment.

Deposition of thermal and hot-wire chemical vapor deposition copper thin films on patterned substrates.

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Papadimitropoulos, G; Davazoglou, D

2011-09-01

In this work we study the hot-wire chemical vapor deposition (HWCVD) of copper films on blanket and patterned substrates at high filament temperatures. A vertical chemical vapor deposition reactor was used in which the chemical reactions were assisted by a tungsten filament heated at 650 degrees C. Hexafluoroacetylacetonate Cu(I) trimethylvinylsilane (CupraSelect) vapors were used, directly injected into the reactor with the aid of a liquid injection system using N2 as carrier gas. Copper thin films grown also by thermal and hot-wire CVD. The substrates used were oxidized silicon wafers on which trenches with dimensions of the order of 500 nm were formed and subsequently covered with LPCVD W. HWCVD copper thin films grown at filament temperature of 650 degrees C showed higher growth rates compared to the thermally ones. They also exhibited higher resistivities than thermal and HWCVD films grown at lower filament temperatures. Thermally grown Cu films have very uniform deposition leading to full coverage of the patterned substrates while the HWCVD films exhibited a tendency to vertical growth, thereby creating gaps and incomplete step coverage.

Mineralogy, geochemistry and origin of Zafarabad iron deposit based on REE and trace elements of magnetite

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Mehrdad Barati

2013-10-01

Full Text Available Zafarabad iron deposit is located northwest of Divandareh, in the northern margin of Sanandaj-Sirjan plutonic-metamorphic zone. The deposit is in lentoid to tubular shape, within a shear zone and occrrued in host rocks of calc-schist and limestone. Magnetite with massive, cataclastic and replacement textures are the main phases, while pyrite and other sulfide minerals are found. Major and trace elements are measured by ICP-MS and ICP-AES methods. Based on some ratios of trace elements in the ore samples and (Ti+V vs. Cal+Al+Mn and Ti+V vs. Ni/(Cr+Mn diagrams which are used for classification of iron deposit types, Zafarabad iron deposit fall in the range of skarn deposits. Spider diagrams show a steady decline from LREE to HREE elements with Eu (mean value of 0.06 ppm and Ce (mean value of 0.94 ppm negative anomalies. Comparing the distribution patterns of REE for the Zafarabad magnetites with those of various types of iron deposits shows that the REE pattern for Zafarabad is similar to these deposits. Analysis of calculated parameters for REE shows that the hydrothermal fluids responsible for mineralization are mainly of magmatic origin through fractionation and crystallization processes of a deep iron rich fluid phase and its emplacement within the carbonate rocks, forming iron skarn.

Hot iron rods branding, its complications: Still continue in central India

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Seema Mahant

2017-01-01

Full Text Available Introduction: The middle of the 20th century has often been described as a golden age of scientific advancement and miraculous medical breakthroughs. In spite of a lot of awareness and many health education programs, still some traditional treatment exists in many places in our country including Central India. In some villages of Madhya Pradesh, many horrifying therapies such as iron rods branding are well known for a few common diseases such as ascites, headache, pneumonia, common cold, or hernia. Bruise marks can be seen on the bodies of a majority of villagers. Main reasons behind such therapy are lack of money for medical treatment, lack of medical facilities, and the unwillingness of medical officers to stay in small villages. Besides this, illiteracy compels them to follow old customs and practices. All these strengthen the faith of villagers in such treatments. It is all due to lack of education and proper awareness. Many female patients come to hospital with complications of iron rods branding suggest that despite being educated, strong cultural beliefs forces people to undergo branding as a treatment of many common diseases in India even in the 21st century. Aims and Objectives: To study the reasons and complications of hot iron branding. Materials and Methods: Sample size was 30. Thirty patients with old, healed (within 1 year, or recent scars of iron branding were included in the study. Patients were evaluated for the sociodemographic details and the information of underlying disease, pattern of lesions, and complications of branding. Results: Hot iron branding is still carrying on as traditional treatment in Central India. It is commonly seen in females of age 20–50 years. It is mostly found in illiterate patients of low socioeconomic status who have chronic disease and chronic pain. Conclusion: Skin branding which still has therapeutic uses in some cultural societies have severe medical complications in Central India.

REVIEW OF COASTAL CHARACTERISTICS OF IRON SAND DEPOSITS IN CILACAP CENTRAL JAVA

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Hananto Kurnio

2017-07-01

Full Text Available Mineable iron sand deposits in Cilacap – southern coastal area of Central Java have certain coastal characteristics that need to be studied in order to understand its depositional environment. With the knowledge of such environment, it can be applied to look for other places prospective of iron sand deposits that have the same characteristics especially recently when Cilacap’s deposits were almost depleted. Coastal characteristics of iron sand deposit in Cilacap is shown by successive sandy beach ridges separated by marshy valleys typical of prograded coasts and by dunes of sand elongated parallel to the shore line with elevation varies from 0 m to 15 m above sea level. The iron sand deposit was derived from denudation of andesite and “Old Andesite Formation” enriched in magnetite and ilmenite minerals in the steep elevated and deeply weathered rock hinterlands of Cilacap. High sediment loads of Serayu Basin in the hinterland (3,500-4,500 ton/km2/year; Citarum River basin only 800-1,200 ton/km2/year was causing extensive deposition of iron sand in the coastal zone. Key words: coast, characteristic, iron sand, Cilacap Endapan pasir besi yang dapat ditambang di Cilacap – pesisir selatan Jawa Tengah memiliki karakteristik pantai tertentu yang perlu dikaji agar dapat dipahami lingkungan pengendapannya. Dengan pengetahuan tentang lingkungan pengendapan tersebut, dapat diterapkan untuk mencari daerah-daerah lain prospek endapan pasir besi yang memiliki karakteristik yang sama terutama pada akhir-akhir ini ketika endapan Cilacap akan habis. Karakteristik pantai endapan pasir besi di Cilacap dicirikan oleh urutan pematang pantai berpasir yang dipisahkan oleh lembah-lembah berawa khas pantai maju dan oleh gumuk-gumuk pasir memanjang sejajar dengan garis pantai dengan ketinggian bervariasi dari 0 m hingga 15 m dari muka laut. Endapan pasir besi di daerah ini berasal dari proses denudasi andesit dan “Formasi Andesit

Ionization processes in the Fe 27 region of hot iron plasma in the field of hard gamma radiation

International Nuclear Information System (INIS)

Illarionov, A.F.

1989-01-01

A highly ionized hot plasma of an iron 26 56 Fe-type heavy element in the field of hard ionizing gamma-ray radiation is considered. The processes of ionization and recombination are discussed for a plasma consisting of the fully ionized Fe 27 and the hydrogen-like Fe 26 ions of iron in the case of large optical depth of the plasma with respect to the photoionization by gamma-ray quanta. The self-ionization process of a hot plasma with the temperature kT ≅ I (I being the ionization potential), due to the production of the own ionizing gamma-ray quanta, by the free-free (ff) and recombination (fb) radiation mechanisms, is investigated. It is noted that in the stationary situation the process of self-ionization of a hot plasma imposes the restriction upon the plasma temperature, kT<1.5 I. It is shown that the ionization of heavy-ion plasma by the impact of thermal electrons is dominating over the processes of ff- and fb-selfionization of plasma only by the large concentration of hydrogen-like iron at the periphery of the region of fully ionized iron Fe 27

Iron deposits in the knee joints of a thalassemic patient

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Charalambos P Economides

2013-02-01

Full Text Available The overall prognosis for patients with ß-thalassemia has improved considerably during the past decades mainly due to regular blood transfusions, improvements in chelation therapy, and enhanced surveillance with imaging studies examining iron overload and other clinical complications. However, the prolonged survival of these patients leads to the development of other health problems including degenerative diseases such as arthropathies, which require further attention since they have a significant impact on the quality of life. In the current case report, we present a 45-year-old white man with ß-thalassemia complaining of non-traumatic pain and restriction in the range of motion of both knees. Magnetic resonance imaging (MRI revealed a tear in the medial meniscus of the left knee as well as iron deposits in both knees. Histological findings confirmed the presence of hemosiderin in both joints. To our knowledge, this is the first reported case of macroscopically documented iron deposits in the knee joints of a patient with ß-thalassemia using MRI.

IRON-TOLERANT CYANOBACTERIA: IMPLICATIONS FOR ASTROBIOLOGY

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Brown, Igor I.; Allen, Carlton C.; Mummey, Daniel L.; Sarkisova, Svetlana A.; McKay, David S.

2006-01-01

The review is dedicated to the new group of extremophiles - iron tolerant cyanobacteria. The authors have analyzed earlier published articles about the ecology of iron tolerant cyanobacteria and their diversity. It was concluded that contemporary iron depositing hot springs might be considered as relative analogs of Precambrian environment. The authors have concluded that the diversity of iron-tolerant cyanobacteria is understudied. The authors also analyzed published data about the physiological peculiarities of iron tolerant cyanobacteria. They made the conclusion that iron tolerant cyanobacteria may oxidize reduced iron through the photosystem of cyanobacteria. The involvement of both Reaction Centers 1 and 2 is also discussed. The conclusion that iron tolerant protocyanobacteria could be involved in banded iron formations generation is also proposed. The possible mechanism of the transition from an oxygenic photosynthesis to an oxygenic one is also discussed. In the final part of the review the authors consider the possible implications of iron tolerant cyanobacteria for astrobiology.

HO-1-mediated macroautophagy: a mechanism for unregulated iron deposition in aging and degenerating neural tissues.

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Zukor, Hillel; Song, Wei; Liberman, Adrienne; Mui, Jeannie; Vali, Hojatollah; Fillebeen, Carine; Pantopoulos, Kostas; Wu, Ting-Di; Guerquin-Kern, Jean-Luc; Schipper, Hyman M

2009-05-01

Oxidative stress, deposition of non-transferrin iron, and mitochondrial insufficiency occur in the brains of patients with Alzheimer disease (AD) and Parkinson disease (PD). We previously demonstrated that heme oxygenase-1 (HO-1) is up-regulated in AD and PD brain and promotes the accumulation of non-transferrin iron in astroglial mitochondria. Herein, dynamic secondary ion mass spectrometry (SIMS) and other techniques were employed to ascertain (i) the impact of HO-1 over-expression on astroglial mitochondrial morphology in vitro, (ii) the topography of aberrant iron sequestration in astrocytes over-expressing HO-1, and (iii) the role of iron regulatory proteins (IRP) in HO-1-mediated iron deposition. Astroglial hHO-1 over-expression induced cytoplasmic vacuolation, mitochondrial membrane damage, and macroautophagy. HO-1 promoted trapping of redox-active iron and sulfur within many cytopathological profiles without impacting ferroportin, transferrin receptor, ferritin, and IRP2 protein levels or IRP1 activity. Thus, HO-1 activity promotes mitochondrial macroautophagy and sequestration of redox-active iron in astroglia independently of classical iron mobilization pathways. Glial HO-1 may be a rational therapeutic target in AD, PD, and other human CNS conditions characterized by the unregulated deposition of brain iron.

The long term tsunami impact: Evolution of iron speciation and major elements concentration in tsunami deposits from Thailand.

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Kozak, Lidia; Niedzielski, Przemyslaw

2017-08-01

The article describes the unique studies of the chemical composition changes of new geological object (tsunami deposits in south Thailand - Andaman Sea Coast) during four years (2005-2008) from the beginning of formation of it (deposition of tsunami transported material, 26 December 2004). The chemical composition of the acid leachable fraction of the tsunami deposits has been studied in the scope of concentration macrocompounds - concentration of calcium, magnesium, iron, manganese and iron speciation - the occurrence of Fe(II), Fe(III) and non-ionic iron species described as complexed iron (Fe complex). The changes of chemical composition and iron speciation in the acid leachable fraction of tsunami deposits have been observed with not clear tendencies of changes direction. For iron speciation changes the transformation of the Fe complex to Fe(III) has been recorded with no significant changes of the level of Fe(II). Copyright © 2017 Elsevier Ltd. All rights reserved.

Iron deposits in the chronically inflamed central nervous system and contributes to neurodegeneration.

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Andersen, Hjalte Holm; Johnsen, Kasper Bendix; Moos, Torben

2014-05-01

Neurodegenerative disorders are characterized by the presence of inflammation in areas with neuronal cell death and a regional increase in iron that exceeds what occurs during normal aging. The inflammatory process accompanying the neuronal degeneration involves glial cells of the central nervous system (CNS) and monocytes of the circulation that migrate into the CNS while transforming into phagocytic macrophages. This review outlines the possible mechanisms responsible for deposition of iron in neurodegenerative disorders with a main emphasis on how iron-containing monocytes may migrate into the CNS, transform into macrophages, and die out subsequently to their phagocytosis of damaged and dying neuronal cells. The dying macrophages may in turn release their iron, which enters the pool of labile iron to catalytically promote formation of free-radical-mediated stress and oxidative damage to adjacent cells, including neurons. Healthy neurons may also chronically acquire iron from the extracellular space as another principle mechanism for oxidative stress-mediated damage. Pharmacological handling of monocyte migration into the CNS combined with chelators that neutralize the effects of extracellular iron occurring due to the release from dying macrophages as well as intraneuronal chelation may denote good possibilities for reducing the deleterious consequences of iron deposition in the CNS.

Geochemistry and the origin of the Mamouniyeh iron ore-terra rossa deposit, Markazi Province - Iran

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Marziyeh Mahboubiyan Fard

2017-11-01

Full Text Available Introduction Iron is among the metals whose ore deposits are not confined to a specific geologic period of crustal formation and they have formed in various geologic environments during previous periods (Ghorbani, 2007. About 95% of iron ore deposits have sedimentary origin and have formed due to chemical deposition from ancient sea water. The remaining percent is the result of alteration and magmatic activities (Gutzmer and Beukes, 2009. In sedimentary environments, a large amount of sedimentary iron minerals have formed resulting in different iron facies. Iron oxide facies are of the most important facies (James, 1954. The most important Iranian iron deposits are located in Central Iran, Sanandaj- Sirjan and East Iran zones, and the Kordestan area (Ghorbani, 2007. In the Orumiyeh-Dokhtar Zone, many iron ore deposits have been formed in conjunction with granitic and granodioritic plutons related to Oligocene-Miocene plutonic and volcanic activities (Hoshmandzadeh, 1995. The Mamouniyeh iron ore-terra rossa deposit is located in the Orumiyeh-Dokhtar volcanic zone. Iron mineralization have occurred in trachytic-trachyandesitic lavas and pyroclastic rocks of Pliocene age. Materials and methods A total of 28 rock samples were picked up from ore and host rocks during field observations. Petrographical and mineralogical studies were performed on 15 thin sections of ore and host rocks. XRD studies were performed on 3 ore samples. In order to investigate the geochemistry of the ore, 10 samples were analyzed for major, trace and rare earth elements (REEs using the ICP-MS method. Result Field and mineralogical studies reveal that the ore is composed of hematite along with crypto-crystalline silica as alternating layers of various thickness and color. The existence of alternating layers of hematite and quartz implies that the ore is similar to banded iron formations, but on a smaller scale, related to submarine hydrothermal activities. Silica is found as

A deposit model for magmatic iron-titanium-oxide deposits related to Proterozoic massif anorthosite plutonic suites: Chapter K in Mineral Deposit Models for Resource Assessment

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Woodruff, Laurel G.; Nicholson, Suzanne W.; Fey, David L.

2013-01-01

This descriptive model for magmatic iron-titanium-oxide (Fe-Ti-oxide) deposits hosted by Proterozoic age massif-type anorthosite and related rock types presents their geological, mineralogical, geochemical, and geoenvironmental attributes. Although these Proterozoic rocks are found worldwide, the majority of known deposits are found within exposed rocks of the Grenville Province, stretching from southwestern United States through eastern Canada; its extension into Norway is termed the Rogaland Anorthosite Province. This type of Fe-Ti-oxide deposit dominated by ilmenite rarely contains more than 300 million tons of ore, with between 10- to 45-percent titanium dioxide (TiO2), 32- to 45-percent iron oxide (FeO), and less than 0.2-percent vanadium (V).

Hot wire deposited hydrogenated amorphous silicon solar cells

Energy Technology Data Exchange (ETDEWEB)

Mahan, A.H.; Iwaniczko, E.; Nelson, B.P.; Reedy, R.C. Jr.; Crandall, R.S. [National Renewable Energy Lab., Golden, CO (United States)

1996-05-01

This paper details the results of a study in which low H content, high deposition rate hot wire (HW) deposited amorphous silicon (a-Si:H) has been incorporated into a substrate solar cell. The authors find that the treatment of the top surface of the HW i layer while it is being cooled from its high deposition temperature is crucial to device performance. They present data concerning these surface treatments, and correlate these treatments with Schottky device performance. The authors also present first generation HW n-i-p solar cell efficiency data, where a glow discharge (GD) {mu}c-Si(p) layer was added to complete the partial devices. No light trapping layer was used to increase the device Jsc. Their preliminary investigations have yielded efficiencies of up to 6.8% for a cell with a 4000 {Angstrom} thick HW i-layer, which degrade less than 10% after a 900 hour light soak. The authors suggest avenues for further improvement of their devices.

Kinetic study on hot-wire-assisted atomic layer deposition of nickel thin films

International Nuclear Information System (INIS)

Yuan, Guangjie; Shimizu, Hideharu; Momose, Takeshi; Shimogaki, Yukihiro

2014-01-01

High-purity Ni films were deposited using hot-wire-assisted atomic layer deposition (HW-ALD) at deposition temperatures of 175, 250, and 350 °C. Negligible amount of nitrogen or carbon contamination was detected, even though the authors used NH 2 radical as the reducing agent and nickelocene as the precursor. NH 2 radicals were generated by the thermal decomposition of NH 3 with the assist of HW and used to reduce the adsorbed metal growth precursors. To understand and improve the deposition process, the kinetics of HW-ALD were analyzed using a Langmuir-type model. Unlike remote-plasma-enhanced atomic layer deposition, HW-ALD does not lead to plasma-induced damage. This is a significant advantage, because the authors can supply sufficient NH 2 radicals to deposit high-purity metallic films by adjusting the distance between the hot wire and the substrate. NH 2 radicals have a short lifetime, and it was important to use a short distance between the radical generation site and substrate. Furthermore, the impurity content of the nickel films was independent of the deposition temperature, which is evidence of the temperature-independent nature of the NH 2 radical flux and the reactivity of the NH 2 radicals

Spectral characteristics of banded iron formations in Singhbhum craton, eastern India: Implications for hematite deposits on Mars

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Mahima Singh

2016-11-01

Full Text Available Banded iron formations (BIFs are major rock units having hematite layers intermittent with silica rich layers and formed by sedimentary processes during late Archean to mid Proterozoic time. In terrestrial environment, hematite deposits are mainly found associated with banded iron formations. The BIFs in Lake Superior (Canada and Carajas (Brazil have been studied by planetary scientists to trace the evolution of hematite deposits on Mars. Hematite deposits are extensively identified in Meridiani region on Mars. Many hypotheses have been proposed to decipher the mechanism for the formation of these deposits. On the basis of geomorphological and mineralogical studies, aqueous environment of deposition is found to be the most supportive mechanism for its secondary iron rich deposits. In the present study, we examined the spectral characteristics of banded iron formations of Joda and Daitari located in Singhbhum craton in eastern India to check its potentiality as an analog to the aqueous/marine environment on Mars. The prominent banding feature of banded iron formations is in the range of few millimeters to few centimeters in thickness. Fe rich bands are darker (gray in color compared to the light reddish jaspilitic chert bands. Thin quartz veins (<4 mm are occasionally observed in the hand-specimens of banded iron formations. Spectral investigations have been conducted in VIS/NIR region of electromagnetic spectrum in the laboratory conditions. Optimum absorption bands identified include 0.65, 0.86, 1.4 and 1.9 μm, in which 0.56 and 0.86 μm absorption bands are due to ferric iron and 1.4 and 1.9 μm bands are due to OH/H2O. To validate the mineralogical results obtained from VIS/NIR spectral radiometry, laser Raman and Fourier transform infrared spectroscopic techniques were utilized and the results were found to be similar. Goethite-hematite association in banded iron formation in Singhbhum craton suggests dehydration activity, which has

Minerals of oxidation zone of the Chokadambulaq iron deposit

International Nuclear Information System (INIS)

Safaraliev, N.S.

2008-01-01

The zone of oxidation of Chokadambulaq iron deposit has original mineral composition, which characterized specificity of their formation. Here is formed a secondary zone of enrichment marit ores, having practical meaning. In last is concentrated from 0.5 up to 1.0% from total quantities of reserves

Oncoidal granular iron formation in the Mesoarchaean Pongola Supergroup, southern Africa: Textural and geochemical evidence for biological activity during iron deposition.

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Smith, A J B; Beukes, N J; Gutzmer, J; Czaja, A D; Johnson, C M; Nhleko, N

2017-11-01

We document the discovery of the first granular iron formation (GIF) of Archaean age and present textural and geochemical results that suggest these formed through microbial iron oxidation. The GIF occurs in the Nconga Formation of the ca. 3.0-2.8 Ga Pongola Supergroup in South Africa and Swaziland. It is interbedded with oxide and silicate facies micritic iron formation (MIF). There is a strong textural control on iron mineralization in the GIF not observed in the associated MIF. The GIF is marked by oncoids with chert cores surrounded by magnetite and calcite rims. These rims show laminated domal textures, similar in appearance to microstromatolites. The GIF is enriched in silica and depleted in Fe relative to the interbedded MIF. Very low Al and trace element contents in the GIF indicate that chemically precipitated chert was reworked above wave base into granules in an environment devoid of siliciclastic input. Microbially mediated iron precipitation resulted in the formation of irregular, domal rims around the chert granules. During storm surges, oncoids were transported and deposited in deeper water environments. Textural features, along with positive δ 56 Fe values in magnetite, suggest that iron precipitation occurred through incomplete oxidation of hydrothermal Fe 2+ by iron-oxidizing bacteria. The initial Fe 3+ -oxyhydroxide precipitates were then post-depositionally transformed to magnetite. Comparison of the Fe isotope compositions of the oncoidal GIF with those reported for the interbedded deeper water iron formation (IF) illustrates that the Fe 2+ pathways and sources for these units were distinct. It is suggested that the deeper water IF was deposited from the evolved margin of a buoyant Fe 2+ aq -rich hydrothermal plume distal to its source. In contrast, oncolitic magnetite rims of chert granules were sourced from ambient Fe 2+ aq -depleted shallow ocean water beyond the plume. © 2017 John Wiley & Sons Ltd.

Analysis of Characteristics of Ore about Iron Deposit of Da Hong Mountain in Yun Nan Province

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Zhang Yuefeng

2016-01-01

Full Text Available This thesis aims to analyse the deposit characteristics about Da Hong Mountains Iron ore in Yunnan province. The texture and structure, especially the chemical composition, is different in every section of deposit after comparing. Moreover, the content of SiO2 is much higher than general iron ore. However, the content of other noble metals cannot reach the lowest industrial grade. Da Hong Mountains Iron ore has unique features because of metallogenic periods.

Effect of the Surface Layer of Iron Casting on the Growth of Protective Coating During Hot-Dip Galvanizing

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Kopyciński D.

2016-03-01

Full Text Available The paper presents the results of investigations of the growth of protective coating on the surface of ductile iron casting during the hot-dip galvanizing treatment. Ductile iron of the EN-GJS-600-3 grade was melted and two moulds made by different technologies were poured to obtain castings with different surface roughness parameters. After the determination of surface roughness, the hot-dip galvanizing treatment was carried out. Based on the results of investigations, the effect of casting surface roughness on the kinetics of the zinc coating growth was evaluated. It was found that surface roughness exerts an important effect on the thickness of produced zinc coating.

Investigation of cerebral iron deposition in aged patients with ischemic cerebrovascular disease using susceptibility-weighted imaging

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Liu Y

2016-08-01

Full Text Available Yin Liu, Jun Liu, Huanghui Liu, Yunjie Liao, Lu Cao, Bin Ye, Wei Wang Department of Radiology, The Third Xiangya Hospital, Central South University, Changsha, Hunan, People’s Republic of China Objective: The aim of this study was to investigate focal iron deposition level in the brain in patients with ischemic cerebrovascular disease and its correlation with cerebral small vessel disease imaging markers.Patients and methods: Seventy-four patients with first-ever transient ischemic attack (median age: 69 years; 30 males and 44 females and 77 patients with positive ischemic stroke history (median age: 72 years; 43 males and 34 females were studied retrospectively. On phase image of susceptibility-weighted imaging and regions of interest were manually drawn at the bilateral head of the caudate nucleus, lenticular nucleus (LN, thalamus (TH, frontal white matter, and occipital white matter. The correlation between iron deposition level and the clinical and imaging variables was also investigated.Results: Iron deposition level at LN was significantly higher in patients with previous stroke history. It linearly correlated with the presence and number of cerebral microbleeds (CMBs but not with white matter hyperintensity and lacunar infarct. Multiple linear regression analysis showed that deep structure CMBs were the most relevant in terms of iron deposition at LN.Conclusion: Iron deposition at LN may increase in cases of more severe ischemia in aged patients with transient ischemic attack, and it may be an imaging marker for CMB of ischemic origin. Keywords: cerebral microbleed, ischemia, susceptibility-weighted imaging, iron, lenticular nucleus

Mineralogical and geochemical characteristics of the Noamundi-Koira basin iron ore deposits (India)

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Mirza, Azimuddin; Alvi, Shabbar Habib; Ilbeyli, Nurdane

2015-04-01

India is one of the richest sources of iron ore deposits in the world; and one of them is located in the Noamundi-Koira basin, Singhbhum-Orissa craton. The geological comparative studies of banded iron formation (BIF) and associated iron ores of Noamundi-Koira iron ore deposits, belonging to the iron ore group in eastern India, focus on the study of mineralogy and major elemental compositions along with the geological evaluation of different iron ores. The basement of the Singhbhum-Orissa craton is metasedimentary rocks which can be traced in a broadly elliptical pattern of granitoids, surrounded by metasediments and metavolcanics of Greenstone Belt association. The Singhbhum granitoid is intrusive into these old rocks and to younger, mid Archaean metasediments, including iron formations, schists and metaquartzites and siliciclastics of the Precambrian Iron Ore Group (Saha et al., 1994; Sharma, 1994). The iron ore of Noamundi-Koira can be divided into seven categories (Van Schalkwyk and Beukes 1986). They are massive, hard laminated, soft laminated, martite-goethite, powdery blue dust and lateritic ore. Although it is more or less accepted that the parent rock of iron ore is banded hematite jasper (BHJ), the presence of disseminated martite in BHJ suggests that the magnetite of protore was converted to martite. In the study area, possible genesis of high-grade hematite ore could have occurred in two steps. In the first stage, shallow, meteoric fluids affect primary, unaltered BIF by simultaneously oxidizing magnetite to martite and replacing quartz with hydrous iron oxides. In the second stage of supergene processes, deep burial upgrades the hydrous iron oxides to microplaty hematite. Removal of silica from BIF and successive precipitation of iron resulted in the formation of martite- goethite ore. Soft laminated ores were formed where precipitation of iron was partial or absent. The leached out space remains with time and the interstitial space is generally filled

Reactive adsorption of SO2 on activated carbons with deposited iron nanoparticles.

Science.gov (United States)

Arcibar-Orozco, Javier A; Rangel-Mendez, J Rene; Bandosz, Teresa J

2013-02-15

The effect of iron particle size anchored on the surface of commercial activated carbon on the removal of SO(2) from a gas phase was studied. Nanosize iron particles were deposited using forced hydrolysis of FeCl(3) with or without H(3)PO(4) as a capping agent. Dynamic adsorption experiments were carried out on either dry or pre-humidified materials and the adsorption capacities were calculated. The surface of the initial and exhausted materials was extensively characterized by microscopic, porosity, thermogravimetric and surface chemistry. The results indicate that the SO(2) adsorption capacity increased two and half times after the prehumidification process owing to the formation of H(2)SO(4) in the porous system. Iron species enhance the SO(2) adsorption capacity only when very small nanoparticles are deposited on the pore walls as a thin layer. Large iron nanoparticles block the ultramicropores decreasing the accessibility of the active sites and consuming oxygen that rest adsorption centers for SO(2) molecules. Iron nanoparticles of about 3-4 nm provide highly dispersed adsorption sites for SO(2) molecules and thus increase the adsorption capacity of about 80%. Fe(2)(SO(4))(3) was detected on the surface of exhausted samples. Copyright © 2012 Elsevier B.V. All rights reserved.

Discussion on problems of terrestrial heat and moderate-hot water at an uranium deposit in Jiangxi province

International Nuclear Information System (INIS)

Liu Xiangguo

2003-01-01

According to scientific research and technical summing up reports, based on the field investigation, the possible problems of terrestrial heat and moderate-hot water during the exploitation of an uranium deposit in Jiangxi Province are discussed. The preliminary analysis and discussion on the distribution, distribution regularity, causes of formation and correlation of terrestrial heat and moderate-hot water at the uranium deposit are carried out

Influence of reactive oxygen species during deposition of iron oxide films by high power impulse magnetron sputtering

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Stranak, V.; Hubicka, Z.; Cada, M.; Bogdanowicz, R.; Wulff, H.; Helm, C. A.; Hippler, R.

2018-03-01

Iron oxide films were deposited using high power impulse magnetron sputtering (HiPIMS) of an iron cathode in an argon/oxygen gas mixture at different gas pressures (0.5 Pa, 1.5 Pa, and 5.0 Pa). The HiPIMS system was operated at a repetition frequency f  =  100 Hz with a duty cycle of 1%. A main goal is a comparison of film growth during conventional and electron cyclotron wave resonance-assisted HiPIMS. The deposition plasma was investigated by means of optical emission spectroscopy and energy-resolved mass spectrometry. Active oxygen species were detected and their kinetic energy was found to depend on the gas pressure. Deposited films were characterized by means of spectroscopic ellipsometry and grazing incidence x-ray diffraction. Optical properties and crystallinity of as-deposited films were found to depend on the deposition conditions. Deposition of hematite iron oxide films with the HiPIMS-ECWR discharge is attributed to the enhanced production of reactive oxygen species.

A Holistic Model That Physicochemically Links Iron Oxide - Apatite and Iron Oxide - Copper - Gold Deposits to Magmas

Science.gov (United States)

Simon, A. C.; Reich, M.; Knipping, J.; Bilenker, L.; Barra, F.; Deditius, A.; Lundstrom, C.; Bindeman, I. N.

2015-12-01

Iron oxide-apatite (IOA) and iron oxide-copper-gold deposits (IOCG) are important sources of their namesake metals and increasingly for rare earth metals in apatite. Studies of natural systems document that IOA and IOCG deposits are often spatially and temporally related with one another and coeval magmatism. However, a genetic model that accounts for observations of natural systems remains elusive, with few observational data able to distinguish among working hypotheses that invoke meteoric fluid, magmatic-hydrothermal fluid, and immiscible melts. Here, we use Fe and O isotope data and high-resolution trace element (e.g., Ti, V, Mn, Al) data of individual magnetite grains from the world-class Los Colorados (LC) IOA deposit in the Chilean Iron Belt to elucidate the origin of IOA and IOCG deposits. Values of d56Fe range from 0.08‰ to 0.26‰, which are within the global range of ~0.06‰ to 0.5‰ for magnetite formed at magmatic conditions. Values of δ18O for magnetite and actinolite are 2.04‰ and 6.08‰, respectively, consistent with magmatic values. Ti, V, Al, and Mn are enriched in magnetite cores and decrease systematically from core to rim. Plotting [Al + Mn] vs. [Ti + V] indicates that magnetite cores are consistent with magmatic and/or magmatic-hydrothermal (i.e., porphyry) magnetites. Decreasing Al, Mn, Ti, V is consistent with a cooling trend from porphyry to Kiruna to IOCG systems. The data from LC are consistent with the following new genetic model for IOA and IOCG systems: 1) magnetite cores crystallize from silicate melt; 2) these magnetite crystals are nucleation sites for aqueous fluid that exsolves and scavenges inter alia Fe, P, S, Cu, Au from silicate melt; 3) the magnetite-fluid suspension is less dense that the surrounding magma, allowing ascent; 4) as the suspension ascends, magnetite grows in equilibrium with the fluid and takes on a magmatic-hydrothermal character (i.e., lower Al, Mn, Ti, V); 5) during ascent, magnetite, apatite and

Industrialization of hot wire chemical vapor deposition for thin film applications

NARCIS (Netherlands)

Schropp, Ruud

2015-01-01

The consequences of implementing a Hot Wire Chemical Vapor Deposition (HWCVD) chamber into an existing in-line or roll-to-roll reactor are described. The hardware and operation of the HWCVD production reactor is compared to that of existing roll-to-roll reactors based on Plasma Enhanced Chemical

Regional framework and geology of iron oxide-apatite-rare earth element and iron oxide-copper-gold deposits of the Mesoproterozoic St. Francois Mountains Terrane, southeast Missouri

Science.gov (United States)

Day, Warren C.; Slack, John F.; Ayuso, Robert A.; Seeger, Cheryl M.

2016-01-01

This paper provides an overview on the genesis of Mesoproterozoic igneous rocks and associated iron oxide ± apatite (IOA) ± rare earth element, iron oxide-copper-gold (IOCG), and iron-rich sedimentary deposits in the St. Francois Mountains terrane of southeast Missouri, USA. The St. Francois Mountains terrane lies along the southeastern margin of Laurentia as part of the eastern granite-rhyolite province. The province formed during two major pulses of igneous activity: (1) an older early Mesoproterozoic (ca. 1.50–1.44 Ga) episode of volcanism and granite plutonism, and (2) a younger middle Mesoproterozoic (ca. 1.33–1.30 Ga) episode of bimodal gabbro and granite plutonism. The volcanic rocks are predominantly high-silica rhyolite pyroclastic flows, volcanogenic breccias, and associated volcanogenic sediments with lesser amounts of basaltic to andesitic volcanic and associated subvolcanic intrusive rocks. The iron oxide deposits are all hosted in the early Mesoproterozoic volcanic and volcaniclastic sequences. Previous studies have characterized the St. Francois Mountains terrane as a classic, A-type within-plate granitic terrane. However, our new whole-rock geochemical data indicate that the felsic volcanic rocks are effusive derivatives from multicomponent source types, having compositional similarities to A-type within-plate granites as well as to S- and I-type granites generated in an arc setting. In addition, the volcanic-hosted IOA and IOCG deposits occur within bimodal volcanic sequences, some of which have volcanic arc geochemical affinities, suggesting an extensional tectonic setting during volcanism prior to emplacement of the ore-forming systems.The Missouri iron orebodies are magmatic-related hydrothermal deposits that, when considered in aggregate, display a vertical zonation from high-temperature, magmatic ± hydrothermal IOA deposits emplaced at moderate depths (~1–2 km), to magnetite-dominant IOA veins and IOCG deposits emplaced at shallow

Effect of a cooling gel on pain sensitivity and healing of hot-iron cattle brands.

Science.gov (United States)

Tucker, C B; Mintline, E M; Banuelos, J; Walker, K A; Hoar, B; Drake, D; Weary, D M

2014-12-01

Hot-iron branding is painful for cattle, but little is known about how long this pain lasts or effective alleviation methods. Previous work with pigs indicated that cooling burns with a gel (active ingredient: tea tree oil) improved healing compared to untreated wounds. Steers (210±21 kg) were hot-iron branded and allocated to 1 of 3 treatments: control (n=24), 1 gel application immediately after branding (1X; n=12), or 2 gel applications, 1 immediately after branding and one 1 d later (2X; n=12). Pain sensitivity was assessed by applying a known and increasing force with a von Frey anesthesiometer in 5 locations (in the center, at the top of, and 5 and 10 cm above the brand and on the equivalent location on the nonbranded side of the body) until animals showed a behavioral response. Healing was measured with a 6-point scale (1=fresh brand and 6=no scabbing and fully repigmented). Both measures, along with weight gain and surface temperature of the wound, were recorded before and 1, 2, 3, 7, 14, 21, 28, 35, 56, and 70 d after branding. The gel cooled the brand, with the most obvious differences on the day it was applied (3.7 to 4.2°C cooler than control; day×gel interaction, P=0.004). All wounds were at least partially repigmented by 70 d, but only 46% of brands were fully healed at this time. The healing process was slowed when a gel was applied twice (e.g., at 21 d, healing score of 2.5±0.1 and 2.7±0.1 vs. 2.0±0.2 for control and 1X vs. 2X, respectively; P=0.001). Brands tended to remain painful throughout the 70 d (in the center of the brand; before vs. d 1-35, P≤0.001; d 56, P=0.058; and d 70, P=0.092). Overall, gel had little effect on pain sensitivity. Weight gain was reduced on d 1 after branding compared to all other time points (Pbranding. In addition, by 70 d after the procedure, hot-iron brands still tended to be more painful than nonbranded tissue and 54% were not fully healed. These results raise additional animal welfare concerns about hot-iron

Iron deposition in cranial bone marrow with sickle cell disease: MR assessment using a fat suppression technique

International Nuclear Information System (INIS)

Kaneko, K.; Humbert, J.H.; Kogutt, M.S.; Robinson, A.E.

1993-01-01

Thirteen patients with sickle cell disease (SCD) undergoing transfusion therapy and 8 control patients were examined by magnetic resonance imaging to discriminate bone marrow change due to iron deposition from hematologic marrow hyperplasia. Using T1-weighted spin echo images, only two subjects showed extremely low signal intensity marrow compatible with iron deposition. However, using T2-weighted fast spin echo images with fat suppression, cranial bone marrow in SCD patients with transfusion therapy showed considerably lower signal than that of controls. The main cause of marrow signal decrease in SCD patients with transfusion therapy was considered to be iron deposition due to repeated transfusion therapy rather than red marrow hyperplasia. (orig.)

Microbial involvement in the formation of Cambrian sea-floor silica-iron oxide deposits, Australia

Science.gov (United States)

Duhig, Nathan C.; Davidson, Garry J.; Stolz, Joe

1992-06-01

The Cambrian-Ordovician Mount Windsor volcanic belt in northern Australia is host to stratiform lenses of massive ferruginous chert that are spatially associated with volcanogenic massive sulfide occurrences, in particular the Thalanga zinc-lead-copper-silver deposit. The rocks are composed principally of Fe2O3 and SiO2, with very low concentrations of alkalic elements, and lithogenous elements such as Al, Zr, and Ti; they are interpreted as nearly pure chemical sediments. Textural evidence is documented of the integral role of filamentous bacteria (and/or fungi) in depositing iron from hydrothermal fluids, and of the inorganic precipitation of silica-iron-oxyhydroxide gels that subsequently matured to subcrystalline and crystalline silica forms. At least three distinct iron-accumulating microbial forms are distinguished: networks of septate filaments, nonseptate filament networks, and extremely coarse branching filaments that do not reconnect. Values for δ34S in disseminated pyrite are up to 50‰ lighter than those of contemporaneous Cambrian seawater, suggesting postdepositional colonization of some ironstones by sulfur-reducing bacteria. The site not only preserves the textural interplay of biological and inorganic depositional processes in exhalites, but also extends the oldest known instance of microbial mediation in vent-proximal hydrothermal iron precipitation to at least 500 Ma.

Hot iron branding--not a reasonable requirement for international trade in live ruminants.

Science.gov (United States)

Whiting, Terry L.

2005-01-01

"Brand" means a permanent identification mark of which the letters, numbers and figures used are each three (3) inches or more in length or diameter and are humanely burned into the hide of a live animal with a hot iron or tattoo or caustic chemical substance and is to be considered in relation to its location on the animal and the term relates to both the mark and location. PMID:16363334

Corrosion Behavior of Pipeline Carbon Steel under Different Iron Oxide Deposits in the District Heating System

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Yong-Sang Kim

2017-05-01

Full Text Available The corrosion behavior of pipeline steel covered by iron oxides (α-FeOOH; Fe3O4 and Fe2O3 was investigated in simulated district heating water. In potentiodynamic polarization tests; the corrosion rate of pipeline steel is increased under the iron oxide but the increaseing rate is different due to the differnet chemical reactions of the covered iron oxides. Pitting corrosion was only observed on the α-FeOOH-covered specimen; which is caused by the crevice corrosion under the α-FeOOH. From Mott-Schottky and X-ray diffraction results; the surface reaction and oxide layer were dependent on the kind of iron oxides. The iron oxides deposit increases the failure risk of the pipeline and localized corrosion can be occurred under the α-FeOOH-covered region of the pipeline. Thus, prevention methods for the iron oxide deposit in the district pipeline system such as filtering or periodic chemical cleaning are needed.

Electrochemical deposition of iron sulfide thin films and heterojunction diodes with zinc oxide

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Shoichi Kawai

2014-03-01

Full Text Available Iron sulfide thin films were fabricated by the electrochemical deposition method from an aqueous solution containing FeSO4 and Na2S2O3. The composition ratio obtained was Fe:S:O = 36:56:8. In the photoelectrochemical measurement, a weak negative photo-current was observed for the iron sulfide films, which indicates that its conduction type is p-type. No peaks were observed in X-ray diffraction pattern, and thus the deposited films were considered to be amorphous. For a heterojunction with ZnO, rectification properties were confirmed in the current-voltage characteristics. Moreover, the current was clearly enhanced under AM1.5 illumination.

Chemical fingerprint of iron oxides related to iron enrichment of banded iron formation from the Cauê Formation - Esperança Deposit, Quadrilátero Ferrífero, Brazil: a laser ablation ICP-MS study

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Lucilia Aparecida Ramos de Oliveira

Full Text Available Chemical signatures of iron oxides from dolomitic itabirite and high-grade iron ore from the Esperança deposit, located in the Quadrilátero Ferrífero, indicate that polycyclic processes involving changing of chemical and redox conditions are responsible for the iron enrichment on Cauê Formation from Minas Supergroup. Variations of Mn, Mg and Sr content in different generations of iron oxides from dolomitic itabirite, high-grade iron ore and syn-mineralization quartz-carbonate-hematite veins denote the close relationship between high-grade iron ore formation and carbonate alteration. This indicates that dolomitic itabirite is the main precursor of the iron ore in that deposit. Long-lasting percolation of hydrothermal fluids and shifts in the redox conditions have contributed to changes in the Y/Ho ratio, light/heavy rare earth elements ratio and Ce anomaly with successive iron oxide generations (martite-granular hematite, as well as lower abundance of trace elements including rare earth elements in the younger specularite generations.

Depositional facies and aqueous-solid geochemistry of travertine-depositing hot springs (Angel Terrace, Mammoth Hot Springs, Yellowstone National Park, USA)

Energy Technology Data Exchange (ETDEWEB)

Fouke, B.W.; Farmer, J.D.; Des Marais, D.J.; Pratt, L.; Sturchio, N.C.; Burns, P.C.; Discipulo, M.K.

2000-05-01

Petrographic and geochemical analyses of travertine-depositing hot springs at Angel Terrace, Mammoth Hot Springs, Yellowstone National Park, have been used to define five depositional facies along the spring drainage system. Spring waters are expelled in the vent facies at 71 to 73 C and precipitate mounded travertine composed of aragonite needle botryoids. The apron and channel facies (43--72 C) is floored by hollow tubes composed of aragonite needle botryoids that encrust sulfide-oxidizing Aquificales bacteria. The travertine of the pond facies (30--62 C) varies in composition from aragonite needle shrubs formed at higher temperatures to ridged networks of calcite and aragonite at lower temperatures. Calcite ice sheets, calcified bubbles, and aggregates of aragonite needles (fuzzy dumbbells) precipitate at the air-water interface and settle to pond floors. The proximal-slope facies (28--54 C), which forms the margins of terracette pools, is composed of arcuate aragonite needle shrubs that create small microterracettes on the steep slope face. Finally, the distal-slope facies (28--30 C) is composed of calcite spherules and calcite feather crystals. Despite the presence of abundant microbial mat communities and their observed role in providing substrates for mineralization, the compositions of spring-water and travertine predominantly reflect abiotic physical and chemical processes. Vigorous CO{sub 2} degassing causes a +2 unit increase in spring water pH, as well as Rayleigh-type covariations between the concentration of dissolved inorganic carbon and corresponding {delta}{sup 13}C. Travertine {delta}{sup 13}C and {delta}{sup 18}O are nearly equivalent to aragonite and calcite equilibrium values calculated from spring water in the higher-temperature ({approximately}50--73 C) depositional facies. Conversely, travertine precipitating in the lower-temperature (<{approximately}50 C) depositional facies exhibits {delta}{sup 13}C and {delta}{sup 18}O values that are as

Advanced zirconia-coated carbonyl-iron particles for acidic magnetorheological finishing of chemical-vapor-deposited ZnS and other IR materials

Science.gov (United States)

Salzman, S.; Giannechini, L. J.; Romanofsky, H. J.; Golini, N.; Taylor, B.; Jacobs, S. D.; Lambropoulos, J. C.

2015-10-01

We present a modified version of zirconia-coated carbonyl-iron (CI) particles that were invented at the University of Rochester in 2008. The amount of zirconia on the coating is increased to further protect the iron particles from corrosion when introduced to an acidic environment. Five low-pH, magnetorheological (MR) fluids were made with five acids: acetic, hydrochloric, nitric, phosphoric, and hydrofluoric. All fluids were based on the modified zirconia-coated CI particles. Off-line viscosity and pH stability were measured for all acidic MR fluids to determine the ideal fluid composition for acidic MR finishing of chemical-vapor-deposited (CVD) zinc sulfide (ZnS) and other infrared (IR) optical materials, such as hot-isostatic-pressed (HIP) ZnS, CVD zinc selenide (ZnSe), and magnesium fluoride (MgF2). Results show significant reduction in surface artifacts (millimeter-size, pebble-like structures on the finished surface) for several standard-grade CVD ZnS substrates and good surface roughness for the non-CVD MgF2 substrate when MR finished with our advanced acidic MR fluid.

The Application of Artificial Neural Networks to Ore Reserve Estimation at Choghart Iron Ore Deposit

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Seyyed Ali Nezamolhosseini

2017-01-01

Full Text Available Geo-statistical methods for reserve estimation are difficult to use when stationary conditions are not satisfied. Artificial Neural Networks (ANNs provide an alternative to geo-statistical techniques while considerably reducing the processing time required for development and application. In this paper the ANNs was applied to the Choghart iron ore deposit in Yazd province of Iran. Initially, an optimum Multi Layer Perceptron (MLP was constructed to estimate the Fe grade within orebody using the whole ore data of the deposit. Sensitivity analysis was applied for a number of hidden layers and neurons, different types of activation functions and learning rules. Optimal architectures for iron grade estimation were 3-20-10-1. In order to improve the network performance, the deposit was divided into four homogenous zones. Subsequently, all sensitivity analyses were carried out on each zone.  Finally, a different optimum network was trained and Fe was estimated separately for each zone. Comparison of correlation coefficient (R and least mean squared error (MSE showed that the ANNs performed on four homogenous zones were far better than the nets applied to the overall ore body. Therefore, these optimized neural networks were used to estimate the distribution of iron grades and the iron resource in Choghart deposit. As a result of applying ANNs, the tonnage of ore for Choghart deposit is approximately estimated at 135.8 million tones with average grade of Fe at 56.14 percent. Results of reserve estimation using ANNs showed a good agreement with the geo-statistical methods applied to this ore body in another work.

High-BTU gas production from tar-bearing hot coke oven gas over iron catalyst

Energy Technology Data Exchange (ETDEWEB)

L.Y. Li; K. Morishita; T. Takarada [Gunma University, Gunma (Japan). Department of Biological and Chemical Engineering

2005-07-01

To utilize the tar-bearing hot coke oven gas (the by-product of coke making process) more effectively, a process was developed by converting the hot coke oven gas into a methane rich high-BTU gas over iron-bearing catalysts. The catalytic behaviour of Indonesian limonite ore was mainly discussed. For a reference, a conventional nickel catalyst (Ni/Al{sub 2}O{sub 3}) was employed. Laboratory scale tests were carried out in a two-stage fixed-bed reactor at ambient pressure. A bituminous coal sample was heated at first stage, the volatiles was carried by feed gas and decomposed at second stage. The limonite promoted hydropyrolysis of coal volatiles similar to Ni/Al{sub 2}O{sub 3} catalyst. High yields of total product gas and methane were obtained at 50 vol.% hydrogen atmosphere with a feed gas of 60 ml min{sup -1} hydrogen and 60 ml min{sup -1} nitrogen. After experiments, hydrocarbons heavier than ethane were not observed. Also that, carbon balance was more than 99.8% in coal char, product gases and carbon deposits. It was considered that coal volatiles converted into light gases and carbon almost completely in catalyst bed. Yields of product gas and methane depended upon catalytic temperature. At 923 K, the maximum yield of product gas was achieved at 74.3% for limonite catalyst on carbon balance with methane 83.2 vol.% of the carbonaceous gas products. Comparing with limonite, Fe/Al{sub 2}O{sub 3} and BOF dust samples showed low activities on coal volatiles catalytic decomposition. 21 refs., 5 figs., 3 tabs.

Sulfur Cycling in an Iron Oxide-Dominated, Dynamic Marine Depositional System: The Argentine Continental Margin

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Natascha Riedinger

2017-05-01

Full Text Available The interplay between sediment deposition patterns, organic matter type and the quantity and quality of reactive mineral phases determines the accumulation, speciation, and isotope composition of pore water and solid phase sulfur constituents in marine sediments. Here, we present the sulfur geochemistry of siliciclastic sediments from two sites along the Argentine continental slope—a system characterized by dynamic deposition and reworking, which result in non-steady state conditions. The two investigated sites have different depositional histories but have in common that reactive iron phases are abundant and that organic matter is refractory—conditions that result in low organoclastic sulfate reduction rates (SRR. Deposition of reworked, isotopically light pyrite and sulfurized organic matter appear to be important contributors to the sulfur inventory, with only minor addition of pyrite from organoclastic sulfate reduction above the sulfate-methane transition (SMT. Pore-water sulfide is limited to a narrow zone at the SMT. The core of that zone is dominated by pyrite accumulation. Iron monosulfide and elemental sulfur accumulate above and below this zone. Iron monosulfide precipitation is driven by the reaction of low amounts of hydrogen sulfide with ferrous iron and is in competition with the oxidation of sulfide by iron (oxyhydroxides to form elemental sulfur. The intervals marked by precipitation of intermediate sulfur phases at the margin of the zone with free sulfide are bordered by two distinct peaks in total organic sulfur (TOS. Organic matter sulfurization appears to precede pyrite formation in the iron-dominated margins of the sulfide zone, potentially linked to the presence of polysulfides formed by reaction between dissolved sulfide and elemental sulfur. Thus, SMTs can be hotspots for organic matter sulfurization in sulfide-limited, reactive iron-rich marine sedimentary systems. Furthermore, existence of elemental sulfur and iron

Petrological and geochemical features of the early Paleozoic granitic gneisses and iron ores in the Tianhu iron deposit, Eastern Tianshan, NW China: Implications for ore genesis

Science.gov (United States)

Zheng, Jiahao; Mao, Jingwen; Yang, Fuquan; Chai, Fengmei; Shen, Ping

2017-08-01

This paper reports whole-rock geochemical, zircon U-Pb and Hf isotopic data for ore-hosted granitic gneisses, mineral compositions of oxides, and sulfur isotopic data for sulfides in iron ores from the Tianhu deposit, central part of the Eastern Tianshan. Our results can provide crucial constraints on the genesis of granitic gneisses and early Paleozoic tectonic setting of the Eastern Tianshan. LA-ICP-MS U-Pb dating on magmatic zircons yielded weighted mean 206Pb/238U ages of 463 to 438 Ma, interpreted as the crystallization ages of the granitic protoliths and the formation ages of the Tianhu Group. Zircon U-Pb age of ore-hosted granitic gneiss (ca. 459 Ma) can provide reliable constrains on upper limit for iron mineralization age in the Tianhu deposit. Geochemical characteristics suggest that the protoliths of the Tianhu granitic gneisses are metaluminous to weakly peraluminous high-K calc-alkaline granitic rocks, exhibiting typical subduction-related features such as strong enrichment in LREE and LILE and depletion in HFSE. Zircon Hf isotopic compositions show a positive trend from 463 to 438 Ma, indicating that 460 Ma magmas came from both ancient and juvenile sources, whereas 438 Ma magmas involved more juvenile material. Some early Paleozoic granitoids were recently identified in the Eastern Tianshan with the ages between ca. 475 and ca. 425 Ma. The formation of these early Paleozoic granitoids was in response to subduction processes, suggesting that subduction of Junggar Ocean probably began in the Early Ordovician and lasted until Late Silurian. Pyrite and pyrrhotite in iron ores have δ34SCDT values from + 4.6 to + 15.7‰, which are consistent with the marine source, but inconsistent with the magmatic source or those involved evaporites in skarn iron deposit. Geological, geochemical, and isotopic data suggest that the Tianhu iron ores were formed by volcano-sedimentary processes in a subduction environment during the early Paleozoic time, and Tianhu is a

A deposit model for magmatic iron-titanium-oxide deposits related to Proterozoic massif anorthosite plutonic suites

Science.gov (United States)

Woodruff, Laurel G.; Nicholson, Suzanne W.; Fey, David L.

2013-01-01

This descriptive model for magmatic iron-titanium-oxide (Fe-Ti-oxide) deposits hosted by Proterozoic age massif-type anorthosite and related rock types presents their geological, mineralogical, geochemical, and geoenvironmental attributes. Although these Proterozoic rocks are found worldwide, the majority of known deposits are found within exposed rocks of the Grenville Province, stretching from southwestern United States through eastern Canada; its extension into Norway is termed the Rogaland Anorthosite Province. This type of Fe-Ti-oxide deposit dominated by ilmenite rarely contains more than 300 million tons of ore, with between 10- to 45-percent titanium dioxide (TiO2), 32- to 45-percent iron oxide (FeO), and less than 0.2-percent vanadium (V). The origin of these typically discordant ore deposits remains as enigmatic as the magmatic evolution of their host rocks. The deposits clearly have a magmatic origin, hosted by an age-constrained unique suite of rocks that likely are the consequence of a particular combination of tectonic circumstances, rather than any a priori temporal control. Principal ore minerals are ilmenite and hemo-ilmenite (ilmenite with extensive hematite exsolution lamellae); occurrences of titanomagnetite, magnetite, and apatite that are related to this deposit type are currently of less economic importance. Ore-mineral paragenesis is somewhat obscured by complicated solid solution and oxidation behavior within the Fe-Ti-oxide system. Anorthosite suites hosting these deposits require an extensive history of voluminous plagioclase crystallization to develop plagioclase-melt diapirs with entrained Fe-Ti-rich melt rising from the base of the lithosphere to mid- and upper-crustal levels. Timing and style of oxide mineralization are related to magmatic and dynamic evolution of these diapiric systems and to development and movement of oxide cumulates and related melts. Active mines have developed large open pits with extensive waste-rock piles, but

Geophysical prospecting for iron ore deposit around Tajimi village, Lokoja, North–Central Nigeria

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Bayowa Oyelowo

2016-09-01

Full Text Available Ground magnetic and electrical resistivity survey were undertaken to investigate the occurrence and geometry of iron ore deposit around Tajimi village, Lokoja, North-Central Nigeria. The generated residual map of the ground-magnetic data acquired at 250 stations along 15 traverses revealed numerous prominent anomalies, mostly trending in the N-S direction. The radial power spectrum revealed the depth to magnetic sources between 6 m to 20 m. The interpreted VES data characterized the area into three subsurface layers: top soil, presumably iron ore layer and weathered/fresh basement. The result of vertical electrical sounding curves showed a sudden drop in resistivity (42-241 Ωm over high magnetic response. The geo-electric section revealed that the study area is generally characterized with thin overburden (0.5-1.7 m and the thickness of the second layer (presumed to be the iron ore layer ranged between 6.2-25.1 m. The study concluded that areas of high magnetic intensity showed a sudden drop in resistivity value for the VES points, which give an indication of the presence of an electrically conductive structure presumed to be iron ore deposits.

COMPUTER MODELING OF STRAINS ON PHASE BOUNDARIES IN DUCTILE CAST IRON AT HOT EXTRUSION

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A. I. Pokrovsky

2017-01-01

Full Text Available The computer modeling of the strain distribution in the structure of ductile iron with ferrite-pearlite matrix and inclusions of spherical graphite dependence on increasing degree of deformation during direct hot extrusion was researched. Using a software system of finite-element analysis ANSYS the numerical values of the strains at the phase boundaries: ferrite-perlite, graphiteferrite and also inside the graphite inclusions were defined. The analysis of the strain distribution in the investigated structures was performed and local zones of increased strains were discovered. The results of modeling are compared with metallographic analysis and fracture patterns. The obtained results could be used in the prediction of fracture zones in the cast iron products. 

Oxygen in the Martian atmosphere: Regulation of PO2 by the deposition of iron formations on Mars

Science.gov (United States)

Burns, Roger G.

1992-01-01

During Earth's early history, and prior to the evolution of its present day oxygenated atmosphere, extensive iron rich siliceous sedimentary rocks were deposited, consisting of alternating layers of silica (chert) and iron oxide minerals (hematite and magnetite). The banding in iron formations recorded changes of atmosphere-hydrosphere interactions near sea level in the ancient ocean, which induced the oxidation of dissolved ferrous iron, precipitation of insoluble ferric oxides and silica, and regulation of oxygen in Earth's early atmosphere. Similarities between the Archean Earth and the composition of the present day atmosphere on Mars, together with the pervasive presence of ferric oxides in the Martian regolith suggest that iron formation might also have been deposited on Mars and influenced the oxygen content of the Martian atmosphere. Such a possibility is discussed here with a view to assessing whether the oxygen content of the Martian atmosphere has been regulated by the chemical precipitation of iron formations on Mars.

Fundamental study on carbon composite iron ore hot briquette used as blast furnace burden

Energy Technology Data Exchange (ETDEWEB)

Chu, Man-sheng; Liu, Zheng-gen; Wang, Zhao-cai [Institute of Ferrous Metallurgy, Northeastern University, Shenyang (China); Yagi, Jun-ichiro [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University (Japan)

2011-05-15

Carbon composite iron ore hot briquette (CCB) is the product of fine iron ore and fine coal by hot briquetting process, which attracts more and more attention as a new type of ironmaking raw materials aiming to improve the operation efficiency and reduce the coke consumption of blast furnace. This paper is devoted to experimental study on metallurgical properties of CCB and numerical simulation of the BF operation with CCB charging. At first, the metallurgical properties of CCB, including cold crushing strength, RDI, RSI, reducibility, high temperature strength, and softening and dripping are experimentally tested and compared with the common burdens, which revealed that the CCB possesses the required metallurgical properties and is suitable to use as the blast furnace burden. Then, the effects of charging CCB on the dripping properties of comprehensive burdens are elucidated based on the experiments under simulated blast furnace conditions. The results showed that the maximum charging ratio of CCB in the iron burdens is 40%-50% for achieving appropriate dripping properties of the mixed burdens. Finally, a multi-fluid blast furnace model is used to simulate BF operation with CCB charging. According to model simulations, charging CCB will cause the temperature level to decreases in the furnace and the location of the cohesive zone shifts downward. On the other hand, the productivity tends to increase while coke rate and total reducing agent rate decrease, the heat efficiency improves remarkably and the operation performance of BF is effectively enhanced. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

The pollution of the 'iron gate' reservoir

International Nuclear Information System (INIS)

Babic-Mladenovic, M.; Varga, S; Popovic, L.; Damjanovic, M.

2002-01-01

The paper presents the characteristics of the Iron Gate I (the Djerdap) Water Power and Navigational System, one of the largest in Europe (completed in 1972 by joint efforts of Yugoslavia and Romania). In this paper the attention is devoted to review of the sediment monitoring program and impacts of reservoir sedimentation, as well as to the investigations of water and sediment quality. Special consideration is paid to the issue of sediment pollution research needs. Namely, the hot spot of the 'Iron Gate' sedimentation represents a scarcely known pollution of sediment deposits. The present pollution probably is considerable, since the 'Iron Gate' reservoir drains about 577000 km 2 , with over 80 million inhabitants, and developed municipal and industrial infrastructure. Therefore, in the thirty-year reservoir life various types of sediment-bound pollutants entered and deposited within it. Especially severe incidents happened during 1999 (as a result of NATO bombing campaign) and 2000 (two accidental pollutions in the Tisza river catchment). The study of the 'Iron Gate' reservoir pollution should be prepared in order to enlighten the present state of reservoir sedimentation and pollution. The main objectives of the study are to enhance the government and public awareness of the present environmental state of the 'Iron Gate' reservoir and to serve as a baseline for all future actions. (author)

[Literature review of the influences on error rates when identifying equids with transponder and hot-iron branding].

Science.gov (United States)

Campe, Amely; Schulz, Sophia; Bohnet, Willa

2016-01-01

Although equids have had to be tagged with a transponder since 2009, breeding associations in Germany disagree as to which method is best suited for identification (with or without hot iron branding). Therefore, the aim of this systematic literature review was to gain an overview of how effective identification is using transponders and hot iron branding and as to which factors influence the success of identification. Existing literature showed that equids can be identified by means of transponders with a probability of 85-100%, whereas symbol brandings could be identified correctly in 78-89%, whole number brandings in 0-87% and single figures in 37-92% of the readings, respectively. The successful reading of microchips can be further optimised by a correctly operated implantation process and thorough training of the applying persons. affect identification with a scanner. The removal of transponders for manipulation purposes is virtually impossible. Influences during the application of branding marks can hardly, if at all, be standardised, but influence the subsequent readability relevantly. Therefore, identification by means of hot branding cannot be considered sufficiently reliable. Impaired quality of identification can be reduced during reading but cannot be counteracted. Based on the existing studies it can be concluded that the transponder method is the best suited of the investigated methods for clearly identifying equids, being forgery-proof and permanent. It is not to be expected that applying hot branding in addition to microchips would optimise the probability of identification relevantly.

Preparation of iron-deposited graphite surface for application as cathode material during electrochemical vat-dyeing process

International Nuclear Information System (INIS)

Anbu Kulandainathan, M.; Kiruthika, K.; Christopher, G.; Babu, K. Firoz; Muthukumaran, A.; Noel, M.

2008-01-01

Iron-deposited graphite surfaces were prepared, characterized and employed as cathode materials for electrochemical vat-dyeing process containing very low concentration of sodium dithionite. The electrodeposition, in presence of ammonium thiocyanate and gelatin or animal glue as binding additives, were found to give finer iron deposits for improved electrochemical dyeing application. The electrodeposits were characterized using scanning electron microscopy, electron-dispersive X-ray spectroscopy and X-ray diffraction methods, before and after electrochemical dyeing process. The electrochemical activity of the iron-deposited graphite electrodes always stored in water seems to depend on the surface-bound Fe 3+ /Fe 2+ redox species. Vat dyes like C.I. Vat Violet 1, C.I. Vat Green 1 and C.I. Vat Blue 4 could be efficiently dyed employing these above electrode materials. The colour intensity and washing fastness of the dyed fabrics were found to be equal with conventionally dyed fabrics. The electrodes could also be reused for the dyeing process

Novel Pattern of Iron Deposition in the Fascicula Nigrale in Patients with Parkinson's Disease: A Pilot Study

International Nuclear Information System (INIS)

Peckham, Miriam E.; Dashtipour, Khashayar; Holshouser, Barbara A.; Kani, Camellia; Boscanin, Alex; Kani, Kayvan; Harder, Sheri L.

2016-01-01

Background and Purpose. To determine whether the pattern of iron deposition in the fascicula nigrale in patients with Parkinson's disease would be different from age-matched controls by utilizing quantitative susceptibility mapping to measure susceptibility change. Methods. MRIs of the brain were obtained from 34 subjects, 18 with Parkinson's disease and 16 age- and gender-matched controls. Regions of interest were drawn around the fascicula nigrale and substantia nigra using SWI mapping software by blinded investigators. Statistical analyses were performed to determine susceptibility patterns of both of these regions. Results. Measurements showed significantly increased susceptibility in the substantia nigra in Parkinson's patients and an increased rostral-caudal deposition of iron in the fascicula nigrale in all subjects. This trend was exaggerated with significant correlation noted with increasing age in the Parkinson group. Conclusion. The pattern of an exaggerated iron deposition gradient of the fascicula nigrale in the Parkinson group could represent underlying tract dysfunction. Significant correlation of increasing iron deposition with increasing age may be a cumulative effect, possibly related to disease duration

Synthesis and in vacuo deposition of iron oxide nanoparticles by microplasma-assisted decomposition of ferrocene

International Nuclear Information System (INIS)

Schaefer, Michael; Kumar, Ajay; Mohan Sankaran, R.; Schlaf, Rudy

2014-01-01

Microplasma-assisted gas-phase nucleation has emerged as an important new approach to produce high-purity, nanometer-sized, and narrowly dispersed particles. This study aims to integrate this technique with vacuum conditions to enable synthesis and deposition in an ultrahigh vacuum compatible environment. The ultimate goal is to combine nanoparticle synthesis with photoemission spectroscopy-based electronic structure analysis. Such measurements require in vacuo deposition to prevent surface contamination from sample transfer, which can be deleterious for nanoscale materials. A homebuilt microplasma reactor was integrated into an existing atomic layer deposition system attached to a surface science multi-chamber system equipped with photoemission spectroscopy. As proof-of-concept, we studied the decomposition of ferrocene vapor in the microplasma to synthesize iron oxide nanoparticles. The injection parameters were optimized to achieve complete precursor decomposition under vacuum conditions, and nanoparticles were successfully deposited. The stoichiometry of the deposited samples was characterized in situ using X-ray photoelectron spectroscopy indicating that iron oxide was formed. Additional transmission electron spectroscopy characterization allowed the determination of the size, shape, and crystal lattice of the particles, confirming their structural properties.

Microstructure and geochemical evidences for genesis of the Gol-Gohar iron deposit

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Shahryar Mahmoudi

2017-11-01

Full Text Available Introduction The Gol-Gohar iron ore deposit located in 55 km South West of the city of Sirjan, in the Sanandaj-Sirjan structural zone. Sanandaj-Sirjan zone (SSZ is part of the Alpian-Hymalian orogenic belt and it is located in the west of the central Iran microplate. SSZ represented the metamorphic belt of the Zagros orogeny, that extends for 1500 km from Sirjan in the southeast to Sanandaj in the northwest of Iran (Mohajjel et al, 2003. The Gol-Gohar iron ore deposit is surrounded by a complex of igneous and metamorphic rocks mainly consisting of pelitic schists, basic schists, gneiss, amphibolite, marble, granodiorit, granite and mylonitic granite. In the early studies on the genesis of Gol-Gohr iron deposits, it was considered that sedimentary and tectonic processes were more effective in iron ore deposition. Later studies mainly confirmed a magmatic genesis for Gol-Gohar iron ore (Mucke and Golestaneh, 1982. Although some researchers argued that skarnisation process was the main cause of mineralisation (Hallaj and Jacobpor, 1991؛ Torabian, 2007, still some discussions on Gol-Gohr genesis are underway. Materials and methods – Gol-Gohar mine is divided into three blocks and several exploratory boreholes have been drilled down to 200 to 1400m depths in the third block. The representative samples were taken from exploration drill holes and outcrops around the mine. Microscopic observation (Zeiss Aksioscope in thin and polish sections show that the main ore mineral in the Gol-Gohar deposit is magnetite formed into two types with distinctive optical properties; the milky-gray magnetite (type1 named also “upper ore” and blue to brown magnetite (type2 named also “lower ore” (Mucke and Golestaneh, 1982. Mineralogy and microtectonic study were carried out on 100 thin and 30 polished sections using Zeiss research microscope. For geochemical analyses 20 samples were selected from 3 major exploration drill holes. After whole rock chemical

Effect of Some Sudanese Traditional Hot Iron Branding on Cattle Hide Quality

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Rehab Eltejani Abdelkarim

2016-12-01

Full Text Available This study was designed in order to assess and evaluate the effect of hot iron branding on cattle hide quality. 62 shapes of hot iron branding were detected and classified. Branding damage was evaluated depending on: purpose of application, location in the animal body, branding area, tribe which applied and hide degree. The results showed that, Baggara tribes branding were causing the greater damage on cattle hides; where 71.4% of its brands placed in the abdominal and animal back area (middle of the hide; in proportion to Misseriya Zuraq tribes (68.4%. According to the location of branding, the less tribe that causing damages to the cattle hides were Darfur tribes (14.3%. In terms of branding area Darfur tribes were causing the most branding damages where 42.8% of its brands on cattle hides were between 20-30cm, followed by Baggara tribes where 57.1% of its brands were between 10-20cm then Misseriya Zuraq tribes by 52.6%, and finally North Kordofan tribes of 37.5%. grading of cattle hides depending on the presence of the brand marks the study revealed that, Misseriya Zuraq tribe's brands were obtained the highest percentage (89.4% of the rejected hides (Scarto= 4 and 5 grades, when compared with North Kordofan tribes (87.5%. For commercial reason brand's were mostly done in the area of 5-10cm but, their effect on cattle hide quality was greater, where 81% of the hides were classified as Scarto.

Effects of oxygen gas pressure on properties of iron oxide films grown by pulsed laser deposition

International Nuclear Information System (INIS)

Guo, Qixin; Shi, Wangzhou; Liu, Feng; Arita, Makoto; Ikoma, Yoshifumi; Saito, Katsuhiko; Tanaka, Tooru; Nishio, Mitsuhiro

2013-01-01

Highlights: ► Pulsed laser deposition is a promising technique for growing iron oxide films. ► Crystal structure of the iron oxide films strongly depends on oxygen gas pressure. ► Optimum of the oxygen gas pressure leads single phase magnetite films with high crystal quality. -- Abstract: Iron oxide films were grown on sapphire substrates by pulsed laser deposition at oxygen gas pressures between 1 × 10 −5 and 1 × 10 −1 Pa with a substrate temperature of 600 °C. Atomic force microscope, X-ray diffraction, Raman spectroscopy, X-ray absorption fine structure, and vibrational sample magnetometer analysis revealed that surface morphology and crystal structure of the iron oxide films strongly depend on the oxygen gas pressure during the growth and the optimum oxygen gas pressure range is very narrow around 1 × 10 −3 Pa for obtaining single phase magnetite films with high crystal quality

Oxygen, hydrogen, sulfur, and carbon isotopes in the Pea Ridge magnetite-apatite deposit, southeast Missouri, and sulfur isotope comparisons to other iron deposits in the region

Science.gov (United States)

Johnson, Craig A.; Day, Warren C.; Rye, Robert O.

2016-01-01

Oxygen, hydrogen, sulfur, and carbon isotopes have been analyzed in the Pea Ridge magnetite-apatite deposit, the largest historic producer among the known iron deposits in the southeast Missouri portion of the 1.5 to 1.3 Ga eastern granite-rhyolite province. The data were collected to investigate the sources of ore fluids, conditions of ore formation, and provenance of sulfur, and to improve the general understanding of the copper, gold, and rare earth element potential of iron deposits regionally. The δ18O values of Pea Ridge magnetite are 1.9 to 4.0‰, consistent with a model in which some magnetite crystallized from a melt and other magnetite—perhaps the majority—precipitated from an aqueous fluid of magmatic origin. The δ18O values of quartz, apatite, actinolite, K-feldspar, sulfates, and calcite are significantly higher, enough so as to indicate growth or equilibration under cooler conditions than magnetite and/or in the presence of a fluid that was not entirely magmatic. A variety of observations, including stable isotope observations, implicate a second fluid that may ultimately have been meteoric in origin and may have been modified by isotopic exchange with rocks or by evaporation during storage in lakes.Sulfur isotope analyses of sulfides from Pea Ridge and seven other mineral deposits in the region reveal two distinct populations that average 3 and 13‰. Two sulfur sources are implied. One was probably igneous melts or rocks belonging to the mafic- to intermediate-composition volcanic suite that is present at or near most of the iron deposits; the other was either melts or volcanic rocks that had degassed very extensively, or else volcanic lakes that had trapped rising magmatic gases. The higher δ34S values correspond to deposits or prospects where copper is noteworthy—the Central Dome portion of the Boss deposit, the Bourbon deposit, and the Vilander prospective area. The correspondence suggests that (1) sulfur either limited the deposition

Phanerozoic Rifting Phases And Mineral Deposits

Science.gov (United States)

Hassaan, Mahmoud

2016-04-01

connected with NW,WNW and N-S faults genetically related to volcano-hydrothermal activity associated the Red Sea rifting. At Sherm EL-Sheikh hydrothermal manganese deposit occurs in Oligocene clastics within fault zone. Four iron-manganese-barite mineralization in Esh-Elmellaha plateau are controlled by faults trending NW,NE and nearly E-W intersecting Miocene carbonate rocks. Barite exists disseminated in the ores and as a vein in NW fault. In Shalatee - Halaib district 24 manganese deposits and barite veins with sulphide patches occur within Miocene carbonates distributed along two NW fault planes,trending 240°and 310° and occur in granite and basalt . Uranium -lead-zinc sulfide mineralization occur in Late Proterozoic granite, Late Cretaceous sandstones, and chiefly in Miocene clastic-carbonate-evaporate rocks. The occurrences of uranium- lead-zinc and iron-manganese-barite mineralization have the characteristic features of hypogene cavity filling and replacement deposits correlated with Miocene- Recent Aden volcanic rocks rifting. In western Saudi Arabia barite-lead-zinc mineralization occurs at Lat. 25° 45' and 25° 50'N hosted by Tertiary sediments in limestone nearby basaltic flows and NE-SW fault system. The mineralized hot brines in the Red Sea deeps considered by the author a part of this province. The author considers the constant rifting phases of Pangea and then progressive fragmentation of Western Gondwana during the Late Carboniferous-Lias, Late Jurassic-Early Aptian, Late Aptian - Albian and Late Eocene-Early Miocene and Oligocene-Miocene, responsible for formation of the mineral deposits constituting the M provinces. During these events, rifting, magmatism and hydrothermal activities took place in different peri-continental margins.

Lower Silurian `hot shales' in North Africa and Arabia: regional distribution and depositional model

Science.gov (United States)

Lüning, S.; Craig, J.; Loydell, D. K.; Štorch, P.; Fitches, B.

2000-03-01

Lowermost Silurian organic-rich (`hot') shales are the origin of 80-90% of Palaeozoic sourced hydrocarbons in North Africa and also played a major role in petroleum generation on the Arabian Peninsula. In most cases, the shales were deposited directly above upper Ordovician (peri-) glacial sandstones during the initial early Silurian transgression that was a result of the melting of the late Ordovician icecap. Deposition of the main organic-rich shale unit in the North African/Arabian region was restricted to the earliest Silurian Rhuddanian stage ( acuminatus, atavus and probably early cyphus graptolite biozones). During this short period (1-2 m.y.), a favourable combination of factors existed which led to the development of exceptionally strong oxygen-deficiency in the area. In most countries of the study area, the post-Rhuddanian Silurian shales are organically lean and have not contributed to petroleum generation. The distribution and thickness of the basal Silurian `hot' shales have been mapped in detail for the whole North African region, using logs from some 300 exploration wells in Libya, Tunisia, Algeria and Morocco. In addition, all relevant, accessible published and unpublished surface and subsurface data of the lower Silurian shales in North Africa and Arabia have been reviewed, including sedimentological, biostratigraphic and organic geochemical data. The lowermost Silurian hot shales of northern Gondwana are laterally discontinuous and their distribution and thickness were controlled by the early Silurian palaeorelief which was shaped mainly by glacial processes of the late Ordovician ice age and by Pan-African and Infracambrian compressional and extensional tectonism. The thickest and areally most extensive basal Silurian organic-rich shales in North Africa occur in Algeria, Tunisia and western Libya, while on the Arabian Peninsula they are most prolific in Saudi Arabia, Oman, Jordan and Iraq. The hot shales were not deposited in Egypt, which was a

Iron Oxide Nanoparticles Employed as Seeds for the Induction of Microcrystalline Diamond Synthesis

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Resto Oscar

2008-01-01

Full Text Available AbstractIron nanoparticles were employed to induce the synthesis of diamond on molybdenum, silicon, and quartz substrates. Diamond films were grown using conventional conditions for diamond synthesis by hot filament chemical vapor deposition, except that dispersed iron oxide nanoparticles replaced the seeding. X-ray diffraction, visible, and ultraviolet Raman Spectroscopy, energy-filtered transmission electron microscopy , electron energy-loss spectroscopy, and X-ray photoelectron spectroscopy (XPS were employed to study the carbon bonding nature of the films and to analyze the carbon clustering around the seed nanoparticles leading to diamond synthesis. The results indicate that iron oxide nanoparticles lose the O atoms, becoming thus active C traps that induce the formation of a dense region of trigonally and tetrahedrally bonded carbon around them with the ensuing precipitation of diamond-type bonds that develop into microcrystalline diamond films under chemical vapor deposition conditions. This approach to diamond induction can be combined with dip pen nanolithography for the selective deposition of diamond and diamond patterning while avoiding surface damage associated to diamond-seeding methods.

Effects of Hot Streak and Phantom Cooling on Heat Transfer in a Cooled Turbine Stage Including Particulate Deposition

Energy Technology Data Exchange (ETDEWEB)

Bons, Jeffrey [The Ohio State Univ., Columbus, OH (United States); Ameri, Ali [The Ohio State Univ., Columbus, OH (United States)

2016-01-08

The objective of this research effort was to develop a validated computational modeling capability for the characterization of the effects of hot streaks and particulate deposition on the heat load of modern gas turbines. This was accomplished with a multi-faceted approach including analytical, experimental, and computational components. A 1-year no cost extension request was approved for this effort, so the total duration was 4 years. The research effort succeeded in its ultimate objective by leveraging extensive experimental deposition studies complemented by computational modeling. Experiments were conducted with hot streaks, vane cooling, and combinations of hot streaks with vane cooling. These studies contributed to a significant body of corporate knowledge of deposition, in combination with particle rebound and deposition studies funded by other agencies, to provide suitable conditions for the development of a new model. The model includes the following physical phenomena: elastic deformation, plastic deformation, adhesion, and shear removal. It also incorporates material property sensitivity to temperature and tangential-normal velocity rebound cross-dependencies observed in experiments. The model is well-suited for incorporation in CFD simulations of complex gas turbine flows due to its algebraic (explicit) formulation. This report contains model predictions compared to coefficient of restitution data available in the open literature as well as deposition results from two different high temperature turbine deposition facilities. While the model comparisons with experiments are in many cases promising, several key aspects of particle deposition remain elusive. The simple phenomenological nature of the model allows for parametric dependencies to be evaluated in a straightforward manner. This effort also included the first-ever full turbine stage deposition model published in the open literature. The simulations included hot streaks and simulated vane cooling

Hetero- and homogeneous three-dimensional hierarchical tungsten oxide nanostructures by hot-wire chemical vapor deposition

Energy Technology Data Exchange (ETDEWEB)

Houweling, Z.S., E-mail: Silvester.Houweling@asml.com [Utrecht University, Debye Institute for Nanomaterials Science, Nanophotonics—Physics of Devices, Princetonlaan 4, 3584 CB Utrecht (Netherlands); Harks, P.-P.R.M.L.; Kuang, Y.; Werf, C.H.M. van der [Utrecht University, Debye Institute for Nanomaterials Science, Nanophotonics—Physics of Devices, Princetonlaan 4, 3584 CB Utrecht (Netherlands); Geus, J.W. [Utrecht University, Inorganic Chemistry and Catalysis, Padualaan 8, 3584 CH Utrecht (Netherlands); Schropp, R.E.I. [Utrecht University, Debye Institute for Nanomaterials Science, Nanophotonics—Physics of Devices, Princetonlaan 4, 3584 CB Utrecht (Netherlands)

2015-01-30

We present the synthesis of three-dimensional tungsten oxide (WO{sub 3−x}) nanostructures, called nanocacti, using hot-wire chemical vapor deposition. The growth of the nanocacti is controlled through a succession of oxidation, reduction and re-oxidation processes. By using only a resistively heated W filament, a flow of ambient air and hydrogen at subatmospheric pressure, and a substrate heated to about 700 °C, branched nanostructures are deposited. We report three varieties of simple synthesis approaches to obtain hierarchical homo- and heterogeneous nanocacti. Furthermore, by using catalyst nanoparticles site-selection for the growth is demonstrated. The atomic, morphological and crystallographic compositions of the nanocacti are determined using a combination of electron microscopy techniques, energy-dispersive X-ray spectroscopy and electron diffraction. - Highlights: • Continuous upscalable hot-wire CVD of 3D hierarchical nanocacti • Controllable deposition of homo- and heterogeneous WO{sub 3−x}/WO{sub 3−y} nanocacti • Introduction of three synthesis routes comprising oxidation, reduction and re-oxidation processes • Growth of periodic arrays of hetero- and homogeneous hierarchical 3D nanocacti.

Iron oxide deposits associated with the ectosymbiotic bacteria in the hydrothermal vent shrimp Rimicaris exoculata

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P. Compère

2008-09-01

Full Text Available The Rimicaris exoculata shrimp is considered as a primary consumer that dominates the fauna of most Mid-Atlantic Ridge (MAR hydrothermal ecosystems. These shrimps harbour in their gill chambers an important ectosymbiotic community of chemoautotrophic bacteria associated with iron oxide deposits. The structure and elemental composition of the mineral concretions associated with these bacteria have been investigated by using LM, ESEM, TEM STEM and EDX microanalyses. The nature of the iron oxides in shrimps obtained from the Rainbow vent field has also been determined by Mössbauer spectroscopy. This multidisciplinary approach has revealed that the three layers of mineral crust in the Rimicaris exoculata shrimps consist of large concretions formed by aggregated nanoparticles of two-line ferrihydrite and include other minor elements as Si, Ca, Mg, S and P, probably present as silicates cations, sulphates or phosphates respectively that may contribute to stabilise the ferrihydrite form of iron oxides. TEM-observations on the bacteria have revealed their close interactions with these minerals. Abiotic and biotic precipitation could occur within the gill chamber of Rimicaris exoculata, suggesting the biologically-mediated formation of the iron oxide deposits. The difference of the bacterial density in the three-mineral crust layers could be correlated to the importance of the iron oxide concretions and suggest that the first mineral particles precipitates on the lower layer which could be considered as the most likely location of iron-oxidizing bacteria.

Industrialization of Hot Wire Chemical Vapor Deposition for thin film applications

International Nuclear Information System (INIS)

Schropp, R.E.I.

2015-01-01

The consequences of implementing a Hot Wire Chemical Vapor Deposition (HWCVD) chamber into an existing in-line or roll-to-roll reactor are described. The hardware and operation of the HWCVD production reactor is compared to that of existing roll-to-roll reactors based on Plasma Enhanced Chemical Vapor Deposition. The most important consequences are the technical consequences and the economic consequences, which are both discussed. The technical consequences are adaptations needed to the hardware and to the processing sequences due to the different interaction of the HWCVD process with the substrate and already deposited layers. The economic consequences are the reduced investments in radio frequency (RF) supplies and RF components. This is partially offset by investments that have to be made in higher capacity pumping systems. The most mature applications of HWCVD are moisture barrier coatings for thin film flexible devices such as Organic Light Emitting Diodes and Organic Photovoltaics, and passivation layers for multicrystalline Si solar cells, high mobility field effect transistors, and silicon heterojunction cells (also known as heterojunction cells with intrinsic thin film layers). Another example is the use of Si in thin film photovoltaics. The cost perspective per unit of thin film photovoltaic product using HWCVD is estimated at 0.07 €/Wp for the Si thin film component. - Highlights: • Review of consequences of implementing Hot Wire CVD into a manufacturing plant • Aspects of scaling up to large area and continuous manufacturing are discussed • Economic advantage of introducing a HWCVD process in a production system is estimated • Using HWCVD, the cost for the Si layers in photovoltaic products is 0.08 €/Wp.

Industrialization of Hot Wire Chemical Vapor Deposition for thin film applications

Energy Technology Data Exchange (ETDEWEB)

Schropp, R.E.I., E-mail: r.e.i.schropp@tue.nl

2015-11-30

The consequences of implementing a Hot Wire Chemical Vapor Deposition (HWCVD) chamber into an existing in-line or roll-to-roll reactor are described. The hardware and operation of the HWCVD production reactor is compared to that of existing roll-to-roll reactors based on Plasma Enhanced Chemical Vapor Deposition. The most important consequences are the technical consequences and the economic consequences, which are both discussed. The technical consequences are adaptations needed to the hardware and to the processing sequences due to the different interaction of the HWCVD process with the substrate and already deposited layers. The economic consequences are the reduced investments in radio frequency (RF) supplies and RF components. This is partially offset by investments that have to be made in higher capacity pumping systems. The most mature applications of HWCVD are moisture barrier coatings for thin film flexible devices such as Organic Light Emitting Diodes and Organic Photovoltaics, and passivation layers for multicrystalline Si solar cells, high mobility field effect transistors, and silicon heterojunction cells (also known as heterojunction cells with intrinsic thin film layers). Another example is the use of Si in thin film photovoltaics. The cost perspective per unit of thin film photovoltaic product using HWCVD is estimated at 0.07 €/Wp for the Si thin film component. - Highlights: • Review of consequences of implementing Hot Wire CVD into a manufacturing plant • Aspects of scaling up to large area and continuous manufacturing are discussed • Economic advantage of introducing a HWCVD process in a production system is estimated • Using HWCVD, the cost for the Si layers in photovoltaic products is 0.08 €/Wp.

Nuclear prehistory influence on transfer velocity of 54Mn impurity 'hot' atoms in irradiated metallic iron

International Nuclear Information System (INIS)

Alekseev, I.E.

2007-01-01

Influence of nuclear prehistory on transfer velocity of 54 Mn impurity 'hot'-atoms - got by different nuclear channels: 56 Fe(d, α), 54 Fe(n,p) in irradiated metallic iron - is studied. Irradiation of targets were carried out in U-120 accelerator (energy range 7.3/5.3 MeV, deuteron beam current makes up 5 μA). Mean density of thermal neutron (WWR-M reactor) makes up 8.6·10 13 neutron·cm -2 ·s -1 . It is shown, that transfer velocity of 54 Mn 'hot' atoms is defining by rate of radiation damage of targets in the irradiation process at that a key importance has a bombarding particles type applied for radioactive label getting

[Quantitative magnetic resonance imaging of brain iron deposition: comparison between quantitative susceptibility mapping and transverse relaxation rate (R2*) mapping].

Science.gov (United States)

Guan, Ji-Jing; Feng, Yan-Qiu

2018-03-20

To evaluate the accuracy and sensitivity of quantitative susceptibility mapping (QSM) and transverse relaxation rate (R2*) mapping in the measurement of brain iron deposition. Super paramagnetic iron oxide (SPIO) phantoms and mouse models of Parkinson's disease (PD) related to iron deposition in the substantia nigra (SN) underwent 7.0 T magnetic resonance (MR) scans (Bruker, 70/16) with a multi-echo 3D gradient echo sequence, and the acquired data were processed to obtain QSM and R2*. Linear regression analysis was performed for susceptibility and R2* in the SPIO phantoms containing 5 SPIO concentrations (30, 15, 7.5, 3.75 and 1.875 µg/mL) to evaluate the accuracy of QSM and R2* in quantitative iron analysis. The sensitivities of QSM and R2* mapping in quantitative detection of brain iron deposition were assessed using mouse models of PD induced by 1-methyl-4-phenyl-1,2,3,6-tetrahy-dropyridine (MPTP) in comparison with the control mice. In SPIO phantoms, QSM provided a higher accuracy than R2* mapping and their goodness-of-fit coefficients (R 2 ) were 0.98 and 0.89, respectively. In the mouse models of PD and control mice, the susceptibility of the SN was significantly higher in the PD models (5.19∓1.58 vs 2.98∓0.88, n=5; Pbrain iron deposition than R2*, and the susceptibility derived by QSM can be a potentially useful biomarker for studying PD.

Field experiment for determining lead accumulation in rice grains of different genotypes and correlation with iron oxides deposited on rhizosphere soil.

Science.gov (United States)

Lai, Yu-Cheng; Syu, Chien-Hui; Wang, Pin-Jie; Lee, Dar-Yuan; Fan, Chihhao; Juang, Kai-Wei

2018-01-01

Paddy rice (Oryza sativa L.) is a major staple crop in Asia. However, heavy metal accumulation in paddy soil poses a health risk for rice consumption. Although plant uptake of Pb is usually low, Pb concentrations in rice plants have been increasing with Pb contamination in paddy fields. It is known that iron oxide deposits in the rhizosphere influence the absorption of soil Pb by rice plants. In this study, 14 rice cultivars bred in Taiwan, including ten japonica cultivars (HL21, KH145, TC192, TK9, TK14, TK16, TN11, TNG71, TNG84, and TY3) and four indica cultivars (TCS10, TCS17, TCSW2, and TNGS22), were used in a field experiment. We investigated the genotypic variation in rice plant Pb in relation to iron oxides deposited in the rhizosphere, as seen in a suspiciously contaminated site in central Taiwan. The results showed that the cultivars TCSW2, TN11, TNG71, and TNG84 accumulated brown rice Pb exceeding the tolerable level of 0.2mgkg -1 . In contrast, the cultivars TNGS22, TK9, TK14, and TY3 accumulated much lower brown rice Pb (iron oxides deposited on the rhizosphere soil show stronger affinity to soil-available Pb than those on the root surface to form iron plaque. The relative tendency of Pb sequestration toward rhizosphere soil was negatively correlated with the Pb concentrations in brown rice. The iron oxides deposited on the rhizosphere soil but not on the root surface to form iron plaque dominate Pb sequestration in the rhizosphere. Therefore, the enhancement of iron oxide deposits on the rhizosphere soil could serve as a barrier preventing soil Pb on the root surface and result in reduced Pb accumulation in brown rice. Copyright © 2017 Elsevier B.V. All rights reserved.

Features structure of iron-bearing strata’s of the Bakchar deposit, Western Siberia

Science.gov (United States)

Asochakova, E. M.

2017-12-01

The ore-bearing strata’s of Bakchar deposit have complicated structural-textural heterogeneity and variable mineral composition. This deposit is one of the most promising areas of localization of sedimentary iron ore. The ore-bearing strata’s are composed mainly of sandstones (sometimes with ferruginous pebbles, less often conglomerates), siltstones and clays. The ironstones are classified according to their lithology and geochemistry into three types: goethite-hydrogoethitic oolitic, glauconite-chloritic and transitional (intermediate) type iron ores. The mineral composition includes many different minerals: terrigenous, authigenic and clayey. Ironstones are characterized by elevated concentrations of many rare and valuable metals present in them as trace elements, additionally alloying (Mn, V, Cr, Ti, Zr, Mo, etc.) and harmful impurities (S, As, Cu, Pb, Zn, P). There are prerequisites for the influence of numerous factors, such as prolonged transgression of the sea, swamping of paleo-river deltas, the appearance of a tectonic fracture zone associated with active bottom tectonics and unloading of catagenetic waters, regression and natural ore enrichment due to the re-washing of slightly-iron rocks. These factors are reflected in the structure of the ore-bearing strata in which rhythmic cycles of ore sedimentation with successive changes in them are distinguished by an association of different mineral composition.

Pain sensitivity and healing of hot-iron cattle brands.

Science.gov (United States)

Tucker, C B; Mintline, E M; Banuelos, J; Walker, K A; Hoar, B; Varga, A; Drake, D; Weary, D M

2014-12-01

Hot-iron branding is painful for cattle, but little is known about the duration of or effective methods to control this pain. This work quantified pain sensitivity and healing in branded and unbranded animals. In addition, the effects of a single injection of nonsteroidal anti-inflammatory drug (NSAID) were also considered; this has been suggested as practical method of mitigating pain in the hours after the procedure. Calves (mean±SE, 126±2.2 d and 112±2.8 kg) were hot-iron branded and allocated to 1 of 4 treatments: branded with or without flunixin meglumine (intravenous; 1.1 mg/kg) and unbranded with or without this NSAID (n=12/treatment). Pain sensitivity was assessed by applying a known and increasing force with a von Frey anesthesiometer in the center of the brand (or equivalent area in nonbranded treatments) until animals showed a behavioral response. Healing was measured with a 6-point scale (1=fresh brand and 6=no scabbing and fully repigmented). These measures, along with weight gain and surface temperature, were recorded 1, 2, 7, 14, 21, 28, 35, 42, 56, and 71 d after branding. Lying behavior was recorded with loggers from the day before to d 27 after branding. Brand wounds were more painful than nonbranded tissue (Pbranding (e.g., d 7; 113±36 g of force for Brand vs. 449±23 g force for No brand, mean±SE) but persisted until d 71 (380±37 g force for Brand vs. 453±23 g of force for No brand, mean±SE); only 67% of brands were fully regimented or healed by this time. The first fully healed brand was identified 8 wk after the procedure. Giving a single injection of flunixin had no brand-specific effects on sensitivity, surface temperature, or healing but improved weight gain in the days after branding in all treated groups (flunixin×brand×day, Pbranding but tended to spend more time lying on d 15 and 26 after the procedure. The magnitude of these differences is small, less than the day-to-day variation, and not brand specific. In summary, brand

Structural properties of WO{sub 3} dependent of the annealing temperature deposited by hot-filament metal oxide deposition

Energy Technology Data Exchange (ETDEWEB)

Flores M, J. E. [Benemerita Universidad Autonoma de Puebla, Facultad de Ciencias de la Electronica, Av. San Claudio y 18 Sur, Ciudad Universitaria, Col. Jardines de San Manuel, 72570 Puebla (Mexico); Diaz R, J. [IPN, Centro de Investigacion en Biotecnologia Aplicada, Ex-Hacienda de San Molino Km 1.5 Tepetitla, 90700 Tlaxcala (Mexico); Balderas L, J. A., E-mail: eflores@ece.buap.mx [IPN, Unidad Profesional Interdisciplinaria de Biotecnologia, Av. Acueducto s/n, Col. Barrio la Laguna, 07340 Mexico D. F. (Mexico)

2012-07-01

In this work presents a study of the effect of the annealing temperature on structural and optical properties of WO{sub 3} that has been grown by hot-filament metal oxide deposition. The chemical stoichiometry was determined by X-ray photoelectron spectroscopy. By X-ray diffraction obtained that the as-deposited WO{sub 3} films present mainly monoclinic crystalline phase. WO{sub 3} optical band gap energy can be varied from 2.92 to 3.15 eV obtained by transmittance measurements by annealing WO{sub 3} from 100 to 500 C. The Raman spectrum of the as-deposited WO{sub 3} film shows four intense peaks that are typical Raman peaks of crystalline WO{sub 3} (m-phase) that corresponds to the stretching vibrations of the bridging oxygen that are assigned to W-O stretching ({upsilon}) and W-O bending ({delta}) modes, respectively, which enhanced and increased their intensity with the annealing temperature. (Author)

Detection of iron-depositing Pedomicrobium species in native biofilms from the Odertal National Park by a new, specific FISH probe.

Science.gov (United States)

Braun, Burga; Richert, Inga; Szewzyk, Ulrich

2009-10-01

Iron-depositing bacteria play an important role in technical water systems (water wells, distribution systems) due to their intense deposition of iron oxides and resulting clogging effects. Pedomicrobium is known as iron- and manganese-oxidizing and accumulating bacterium. The ability to detect and quantify members of this species in biofilm communities is therefore desirable. In this study the fluorescence in situ hybridization (FISH) method was used to detect Pedomicrobium in iron and manganese incrusted biofilms. Based on comparative sequence analysis, we designed and evaluated a specific oligonucleotide probe (Pedo 1250) complementary to the hypervariable region 8 of the 16S rRNA gene for Pedomicrobium. Probe specificities were tested against 3 different strains of Pedomicrobium and Sphingobium yanoikuyae as non-target organism. Using optimized conditions the probe hybridized with all tested strains of Pedomicrobium with an efficiency of 80%. The non-target organism showed no hybridization signals. The new FISH probe was applied successfully for the in situ detection of Pedomicrobium in different native, iron-depositing biofilms. The hybridization results of native bioflims using probe Pedo_1250 agreed with the results of the morphological structure of Pedomicrobium bioflims based on scanning electron microscopy.

APPLICATION OF MAGNETIC SURVEY TO EXPLORE THE IRON ORE DEPOSITS IN THE NUSAWUNGU COASTAL REGENCY OF CILACAP CENTRAL JAVA

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S Sehah

2017-12-01

Full Text Available The research aiming to explore the iron ore deposits in the Nusawungu coastal Regency of Cilacap has been conducted using the magnetic survey. The acquisition of magnetic data was conducted in April – Mei 2017, covering the area in the ranges of 109.314° – 109.345°E and 7.691° – 7.709°S. The obtained magnetic field strength data were corrected, reduced, and mapped to obtain the contour map of local magnetic anomaly. The modeling process was carried out along the path extending over the map from the positions of 109.314°E and 7.695°S to 109.335°E and 7.699°S, so that some subsurface anomalous objects are obtained. The lithological interpretation was performed to identify the types of subsurface rocks and their formations based on the magnetic susceptibility value of each anomalous objects and supported by the geological information of the research area. Based on the interpretation results, three rocks deposits of alluvium formations were obtained, which are estimated to contain iron ore. The first deposit has a length of 164.85 m, a depth of 0.57 – 8.43 m, and a magnetic susceptibility value of 0.0097 cgs. The second deposit has a length of 376.28 m, a depth of 2.56 – 19.66 m, and a magnetic susceptibility value of 0.0108 cgs. The third deposit has a length of 1,306.26 m, a depth of 3.70 – 58.69 m, and a magnetic susceptibility value of 0.0235 cgs. Out of the whole rocks deposits, the third rock deposit is interpreted to have the most prospective iron ore. This interpretation based on its high magnetic susceptibility value, which indicates the presence of many magnetic minerals (i.e. iron ores in the rock.

Effects of hot-iron disbudding, using regional anaesthesia with and without carprofen, on cortisol and behaviour of calves.

Science.gov (United States)

Stilwell, G; Lima, M S; Carvalho, R C; Broom, D M

2012-04-01

The objective of this study was to assess cortisol and behaviour changes in calves hot-iron disbudded after different analgesic protocols. We assessed the response of 27 calves at 1, 3, 6 and 24 h after disbudding with regional anaesthesia (DA), regional anaesthesia plus carprofen (DAC), disbudded only (D) or sham-disbudded (ND). At 1h cortisol was higher in D compared with all other groups. At 3h DA showed higher cortisol than ND but did not differ from baseline. At 15 min and 1h pain-related behaviours were more frequent in the D group than in all other groups. Group D (3 h) and DA (3 and 6 h) showed more ear flicks and head rubs compared with DAC and ND. We concluded that head rubbing, head shaking and ear flicking are useful behaviours for evaluating pain after hot-iron disbudding. Disbudding causes severe pain in calves and only the association of regional anaesthesia with carprofen assures good welfare for 24 h. Copyright © 2011 Elsevier Ltd. All rights reserved.

PREPARATION AND CHARACTERIZATION OF IRON SULPHIDE THIN FILMS BY CHEMICAL BATH DEPOSITION METHOD

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Anuar Kassim

2010-06-01

Full Text Available FeS2 thin films have been deposited by using low cost chemical bath deposition technique. The films obtained under deposition parameters such as bath temperature (90 °C, deposition period (90 min, electrolyte concentration (0.15 M and pH of the reactive mixture (pH 2.5. The thin films were characterized using X-ray diffraction and atomic force microscopy in order to study the structural and morphological properties. The band gap energy, transition type and absorption properties were determined using UV-Vis Spectrophotometer. X-ray diffraction displayed a pattern consistent with the formation of an orthorhombic structure, with a strong (110 preferred orientation. Atomic force microscopy image showed the substrate surface is well covered with irregular grains. A direct band gap of 1.85 eV was obtained according to optical absorption studies.   Keywords: Iron sulfide, X-ray diffraction, chemical bath deposition, thin films

Cortical T2 signal shortening in amyotrophic lateral sclerosis is not due to iron deposits

Energy Technology Data Exchange (ETDEWEB)

Hecht, M.J.; Neundoerfer, B. [University of Erlangen-Nurenberg, Department of Neurology, Erlangen (Germany); Fellner, C.; Fellner, F.A. [University of Erlangen-Nurenberg, Institute of Diagnostic Radiology, Erlangen (Germany); Landes-Nervenklinik Wagner-Jauregg, Institute of Radiology, Linz (Austria); Schmid, A. [University of Erlangen-Nurenberg, Institute of Diagnostic Radiology, Erlangen (Germany)

2005-11-01

Signal shortening of the motor cortex in T2-weighted MR images is a frequent finding in patients with amyotrophic lateral sclerosis (ALS). The cause of signal shortening in ALS is unknown, although iron deposits have been suggested. To test this hypothesis, we acquired T2*-weighted gradient-echo (GRE) MR images in addition to T2-weighted turbo spin-echo in 69 patients with ALS. Signal shortening in T2-weighted images was found in 31 patients. In T2*-weighted GRE images, only three patients had signal shortening. One patient with additional bifrontal haemorrhage had frontal but no motor cortex signal shortening. Iron deposits do not cause cortical signal shortening in patients with ALS predominantly. Other factors are presumably more important in the generation of cortical T2 shortening in ALS. (orig.)

Cortical T2 signal shortening in amyotrophic lateral sclerosis is not due to iron deposits

International Nuclear Information System (INIS)

Hecht, M.J.; Neundoerfer, B.; Fellner, C.; Fellner, F.A.; Schmid, A.

2005-01-01

Signal shortening of the motor cortex in T2-weighted MR images is a frequent finding in patients with amyotrophic lateral sclerosis (ALS). The cause of signal shortening in ALS is unknown, although iron deposits have been suggested. To test this hypothesis, we acquired T2*-weighted gradient-echo (GRE) MR images in addition to T2-weighted turbo spin-echo in 69 patients with ALS. Signal shortening in T2-weighted images was found in 31 patients. In T2*-weighted GRE images, only three patients had signal shortening. One patient with additional bifrontal haemorrhage had frontal but no motor cortex signal shortening. Iron deposits do not cause cortical signal shortening in patients with ALS predominantly. Other factors are presumably more important in the generation of cortical T2 shortening in ALS. (orig.)

Mineralogy, chemistry of magnetite and genesis of Korkora-1 iron deposit, east of Takab, NW Iran

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Mohammad Maanijou

2014-10-01

Full Text Available Introduction There is an iron mining complex called Shahrak 60 km east of Takab town, NW Iran. The exploration in the Shahrak deposit (general name for all iron deposits of the area started in 1992 by Foolad Saba Noor Co. and continued in several periods until 2008. The Shahrak deposit comprising 10 ore deposits including Korkora-1, Korkora-2, Shahrak-1, Shahrak-2, Shahrak-3, Cheshmeh, Golezar, Sarab-1, Sarab-2, and Sarab-3 deposits Sheikhi, 1995 with total 60 million tons of proved ore reserves. The Fe grade ranges from 45 to 65% (average 50%. The ore reserves of these deposits vary and the largest one is Korkora-1 with 15 million tons of 55% Fe and 0.64% S. The Korkora-1 ore deposit is located in western Azarbaijan and Urumieh-Dokhtar volcanic zone, at the latitude of 36°21.8´, and longitude of 47°32´. Materials and methods Six thin-polished sections were made on magnetite, garnet, and amphibole for EPMA (Electron Probe Micro Analysis. EPMA was performed using a JEOL JXA-733 electron microprobe at the University of New Brunswick, Canada, with wavelength-dispersive spectrometers. Results and discussion Outcropped units of the area are calc-alkaline volcanics of rhyolite, andesite and dacite and carbonate rocks of Qom Formation in which intrusion of diorite to granodiorite and quartzdoirite caused contact metamorphism, alteration plus skarnization and formation of actinolite, talc, chlorite, phlogopite, quartz, calcite, epidote and marblization in the vicinity of the ore deposit. Iron mineralization formed at the contacts of andesite and dacite with carbonates in Oligo-Miocene. The study area consists of skarn, metamorphic rocks, and iron ore zones. The shape of the deposit is lentoid to horizontal with some alteration halos. The ore occurred as replacement, massive, disseminated, open-space filling and breccia. The ore minerals of the deposit include low Ti-magnetite (0.04 to 0.2 wt % Ti, minor apatite, and sulfide minerals such as pyrite

Plasma Deposited Thin Iron Oxide Films as Electrocatalyst for Oxygen Reduction Reaction in Proton Exchange Membrane Fuel Cells

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Lukasz JOZWIAK

2017-02-01

Full Text Available The possibility of using plasma deposited thin films of iron oxides as electrocatalyst for oxygen reduction reaction (ORR in proton exchange membrane fuel cells (PEMFC was examined. Results of energy-dispersive X-ray spectroscopy (EDX and X-ray photoelectron spectroscopy (XPS analysis indicated that the plasma deposit consisted mainly of FeOX structures with the X parameter close to 1.5. For as deposited material iron atoms are almost exclusively in the Fe3+ oxidation state without annealing in oxygen containing atmosphere. However, the annealing procedure can be used to remove the remains of carbon deposit from surface. The single cell test (SCT was performed to determine the suitability of the produced material for ORR. Preliminary results showed that power density of 0.23 mW/cm2 could be reached in the tested cell.DOI: http://dx.doi.org/10.5755/j01.ms.23.1.14406

Radiocarbon Ages and Environments of Deposition of the Wono and Trego Hot Springs Tephra Layers in the Pyramid Lake Subbasin, Nevada

Science.gov (United States)

Benson, L.V.; Smoot, J.P.; Kashgarian, Michaele; Sarna-Wojcicki, A.; Burdett, J.W.

1997-01-01

Uncalibrated radiocarbon data from core PLC92B taken from Wizards Cove in the Pyramid Lake subbasin indicate that the Trego Hot Springs and Wono tephra layers were deposited 23,200 ?? 300 and 27,300 ??300 14C yr B.P. (uncorrected for reservoir effect). Sedimentological data from sites in the Pyramid Lake and Smoke Creek-Black Rock Desert subbasins indicate that the Trego Hot Springs tephra layer was deposited during a relatively dry period when Pyramid Lake was at or below its spill point (1177 m) to the Winnemucca Lake subbasin. The Wono tephra layer was deposited when lake depth was controlled by spill across Emerson Pass sill (1207 m) to the Smoke Creek-Black Rock Desert subbasin. 18O data from core PLC92B also support the concept that the Trego Hot Springs tephra fell into a relatively shallow Pyramid Lake and that the Wono tephra fell into a deeper spilling lake. ?? 1997 University of Washington.

The study of metal sulphide nanomaterials obtained by chemical bath deposition and hot-injection technique

Science.gov (United States)

Maraeva, E. V.; Alexandrova, O. A.; Forostyanaya, N. A.; Levitskiy, V. S.; Mazing, D. S.; Maskaeva, L. N.; Markov, V. Ph; Moshnikov, V. A.; Shupta, A. A.; Spivak, Yu M.; Tulenin, S. S.

2015-11-01

In this study lead sulphide - cadmium sulphide based layers were obtained through chemical deposition of water solutions and cadmium sulphide quantum dots were formed through hot-injection technique. The article discusses the results of surface investigations with the use of atomic force microscopy, Raman spectroscopy and photoluminescence measurements.

Structural and spectroscopic analysis of hot filament decomposed ethylene deposited at low temperature on silicon surface

International Nuclear Information System (INIS)

Tung, F.-K.; Perevedentseva, E.; Chou, P.-W.; Cheng, C.-L.

2005-01-01

The deposition of decomposed ethylene on silicon wafer at lower temperature using hot filament chemical vapor deposition (HFCVD) method was applied to compose thin film of carbon and its compounds with silicon and hydrocarbon structures. The films were analyzed using Raman spectroscopy, X-ray diffraction, and scanning electron microscopy with elemental microanalysis by energy dispersive X-ray spectrometer. The structure and morphology of the early stage of the film deposition was analyzed. The obtaining of SiC as well as diamond-like structure with this method and catalytic influence of chemical admixtures on the film structure and properties are discussed

Search for trans-iron elements in hot, helium-rich white dwarfs with the HST Cosmic Origins Spectrograph

Science.gov (United States)

Hoyer, D.; Rauch, T.; Werner, K.; Kruk, J. W.

2018-04-01

The metal abundances in the atmospheres of hot white dwarfs (WDs) entering the cooling sequence are determined by the preceding Asymptotic Giant Branch (AGB) evolutionary phase and, subsequently, by the onset of gravitational settling and radiative levitation. In this paper, we investigate three hot He-rich WDs, which are believed to result from a late He-shell flash. During such a flash, the He-rich intershell matter is dredged up and dominates the surface chemistry. Hence, in contrast to the usual H-rich WDs, their spectra allow direct access to s-process element abundances in the intershell that were synthesized during the AGB stage. In order to look for trans-iron group elements (atomic number Z > 29), we performed a non-local thermodynamic equilibrium model atmosphere analysis of new ultraviolet spectra taken with the Cosmic Origins Spectrograph aboard the Hubble Space Telescope. One of our program stars is of PG 1159 spectral type; this star, PG 1707+427, has effective temperature Teff = 85 000 K, and surface gravity logg = 7.5. The two other stars are DO white dwarfs: WD 0111+002 has Teff = 58 000 K and log g = 7.7, and PG 0109+111 has Teff = 70 000 K and log g = 8.0. These stars trace the onset of element diffusion during early WD evolution. While zinc is the only trans-iron element we could detect in the PG 1159 star, both DOs exhibit lines from Zn, Ga, Ge, Se; one additionally exhibits lines from Sr, Sn, Te, and I and the other from As. Generally, the trans-iron elements are very abundant in the DOs, meaning that radiative levitation must be acting. Most extreme is the almost six orders of magnitude oversolar abundance of tellurium in PG 0109+111. In terms of mass fraction, it is the most abundant metal in the atmosphere. The two DOs join the hitherto unique hot DO RE 0503-289, in which 14 trans-iron elements had even been identified. Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which

Automated recognition of stratigraphic marker shales from geophysical logs in iron ore deposits

Science.gov (United States)

Silversides, Katherine; Melkumyan, Arman; Wyman, Derek; Hatherly, Peter

2015-04-01

The mining of stratiform ore deposits requires a means of determining the location of stratigraphic boundaries. A variety of geophysical logs may provide the required data but, in the case of banded iron formation hosted iron ore deposits in the Hamersley Ranges of Western Australia, only one geophysical log type (natural gamma) is collected for this purpose. The information from these logs is currently processed by slow manual interpretation. In this paper we present an alternative method of automatically identifying recurring stratigraphic markers in natural gamma logs from multiple drill holes. Our approach is demonstrated using natural gamma geophysical logs that contain features corresponding to the presence of stratigraphically important marker shales. The host stratigraphic sequence is highly consistent throughout the Hamersley and the marker shales can therefore be used to identify the stratigraphic location of the banded iron formation (BIF) or BIF hosted ore. The marker shales are identified using Gaussian Processes (GP) trained by either manual or active learning methods and the results are compared to the existing geological interpretation. The manual method involves the user selecting the signatures for improving the library, whereas the active learning method uses the measure of uncertainty provided by the GP to select specific examples for the user to consider for addition. The results demonstrate that both GP methods can identify a feature, but the active learning approach has several benefits over the manual method. These benefits include greater accuracy in the identified signatures, faster library building, and an objective approach for selecting signatures that includes the full range of signatures across a deposit in the library. When using the active learning method, it was found that the current manual interpretation could be replaced in 78.4% of the holes with an accuracy of 95.7%.

The study of metal sulphide nanomaterials obtained by chemical bath deposition and hot-injection technique

International Nuclear Information System (INIS)

Maraeva, E V; Alexandrova, O A; Levitskiy, V S; Mazing, D S; Moshnikov, V A; Shupta, A A; Spivak, Yu M; Forostyanaya, N A; Maskaeva, L N; Markov, V Ph; Tulenin, S S

2015-01-01

In this study lead sulphide – cadmium sulphide based layers were obtained through chemical deposition of water solutions and cadmium sulphide quantum dots were formed through hot-injection technique. The article discusses the results of surface investigations with the use of atomic force microscopy, Raman spectroscopy and photoluminescence measurements. (paper)

Molecularly ordered aluminum tris-(8-hydroxyquinoline) thin films grown by hot-wall deposition

Energy Technology Data Exchange (ETDEWEB)

Tapponnier, A. [Nonlinear Optics Laboratory, Institute of Quantum Electronics, Swiss Federal Institute of Technology Zuerich (ETH), CH-8093 Zurich (Switzerland)]. E-mail: axelle@phys.ethz.ch; Khan, R.U.A. [Nonlinear Optics Laboratory, Institute of Quantum Electronics, Swiss Federal Institute of Technology Zuerich (ETH), CH-8093 Zurich (Switzerland); Marcolli, C. [Institute of Atmospheric and Climate Sciences, Swiss Federal Institute of Technology Zuerich (ETH), CH-8092 Zurich (Switzerland); Guenter, P. [Nonlinear Optics Laboratory, Institute of Quantum Electronics, Swiss Federal Institute of Technology Zuerich (ETH), CH-8093 Zurich (Switzerland)

2007-01-22

We report on the growth and microstructural analysis of molecularly ordered thin film layers of aluminum tris-(8-hydroxyquinoline) (Alq{sub 3}) by hot-wall deposition onto amorphous glass substrates. Using transmission electron microscopy (TEM), ordering on a scale of 100 nm was observed. Raman measurements of these films indicated that they corresponded to the {alpha}-polymorph of crystalline Alq{sub 3}, and photoluminescence measurements exhibited a single broad peak centered at 500 nm, which is also consistent with the {alpha}-form. As a comparison, we deposited films of Alq3 using organic molecular beam deposition (OMBD), which exhibited no molecular ordering from the TEM studies. For these films, strong point-to-point variations in the Raman spectrum, and the existence of a double peak in the photoluminescence at 500 and 522 nm were observed. These measurements indicate that the OMBD films possess a mixture of both {alpha} and amorphous phases.

Human serum albumin (HSA) adsorption onto a-SiC:H thin films deposited by hot wire chemical vapor deposition

International Nuclear Information System (INIS)

Swain, Bibhu P.

2006-01-01

In the present paper, we report the study of the adsorption behavior of human serum albumin (HSA) onto surfaces of a-SiC:H thin films deposited by using the hot wire chemical vapor deposition (HWCVD) technique. The surface composition and surface energy of the various substrates as well as the evaluation of the adsorbed amount of protein has been carried out by means of X-ray photoelectron spectroscopy (XPS), Fourier transform infra-red (FTIR) spectroscopy, AFM and contact angle measurements. At the immediate effect of HSA interaction with a-SiC:H films N is adsorbed on the surface and stabilized after 3 days. Preliminary observation found that Si and O atom are desorbed from the surface while C and N set adsorbed to the surface of the a-SiC:H film

Human serum albumin (HSA) adsorption onto a-SiC:H thin films deposited by hot wire chemical vapor deposition

Energy Technology Data Exchange (ETDEWEB)

Swain, Bibhu P. [Department of Metallurgical Engineering and Materials Science, Indian Institute of Technology, Bombay (India) and Samtel Centre for Display Technologies, Indian Institute of Technology Kanpur, India, Kanpur 208016 (India)]. E-mail: bibhup@iitb.ac.in

2006-12-15

In the present paper, we report the study of the adsorption behavior of human serum albumin (HSA) onto surfaces of a-SiC:H thin films deposited by using the hot wire chemical vapor deposition (HWCVD) technique. The surface composition and surface energy of the various substrates as well as the evaluation of the adsorbed amount of protein has been carried out by means of X-ray photoelectron spectroscopy (XPS), Fourier transform infra-red (FTIR) spectroscopy, AFM and contact angle measurements. At the immediate effect of HSA interaction with a-SiC:H films N is adsorbed on the surface and stabilized after 3 days. Preliminary observation found that Si and O atom are desorbed from the surface while C and N set adsorbed to the surface of the a-SiC:H film.

Decreased serum hepcidin concentration correlates with brain iron deposition in patients with HBV-related cirrhosis.

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Dong Lin

brain iron repletion. Serum hepcidin may be a clinical biomarker for brain iron deposition in cirrhotic patients, which may have therapeutic potential.

Evaluation of iron deposits in the reticuloendothelial system using T2-relaxation rate of MRI. Relation with serum ferritin and Fe concentration

International Nuclear Information System (INIS)

Ootsuka, Kae; Togami, Izumi; Kitagawa, Takahiro

1996-01-01

MR imaging is a useful non-invasive technique to detect iron deposits in many organs, but it is difficult to evaluate quantitatively. This study was performed to determine the possibility whether T2 relaxation rate (1/T2) could quantify iron deposits in the reticuloendothelial system (liver, spleen and bone marrow) of 11 patients and four normal volunteers. A moderate correlation was obtained between T2-relaxation rate and the serum ferritin level. These results suggest that T2-relaxation rate may provide useful information for the repeated quantitative evaluation of patients with iron-overload-syndromes. (author)

A novel acidophilic, thermophilic iron and sulfur-oxidizing archaeon isolated from a hot spring of tengchong, yunnan, China

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Jiannan Ding

2011-06-01

Full Text Available A novel thermoacidophilic iron and sulfur-oxidizing archaeon, strain YN25, was isolated from an in situ enriched acid hot spring sample collected in Yunnan, China. Cells were irregular cocci, about 0.9-1.02 µm×1.0-1.31 µm in the medium containing elemental sulfur and 1.5-2.22 µm×1.8-2.54 µm in ferrous sulfate medium. The ranges of growth and pH were 50-85 (optimum 65 and pH 1.0-6.0 (optimum 1.5-2.5. The acidophile was able to grow heterotrophically on several organic substrates, including various monosaccharides, alcohols and amino acids, though the growth on single substrate required yeast extract as growth factor. Growth occurred under aerobic conditions or via anaerobic respiration using elemental sulfur as terminal electron acceptor. Results of morphology, physiology, fatty acid analysis and analysis based on 16S rRNA gene sequence indicated that the strain YN25 should be grouped in the species Acidianus manzaensis. Bioleaching experiments indicated that this strain had excellent leaching capacity, with a copper yielding ratio up to 79.16% in 24 d. The type strain YN25 was deposited in China Center for Type Culture Collection (=CCTCCZNDX0050.

An Analysis of the Published Mineral Resource Estimates of the Haji-Gak Iron Deposit, Afghanistan

International Nuclear Information System (INIS)

Sutphin, David M.; Renaud, Karine M.; Drew, Lawrence J.

2011-01-01

The Haji-Gak iron deposit of eastern Bamyan Province, eastern Afghanistan, was studied extensively and resource calculations were made in the 1960s by Afghan and Russian geologists. Recalculation of the resource estimates verifies the original estimates for categories A (in-place resources known in detail), B (in-place resources known in moderate detail), and C 1 (in-place resources estimated on sparse data), totaling 110.8 Mt, or about 6% of the resources as being supportable for the methods used in the 1960s. C 2 (based on a loose exploration grid with little data) resources are based on one ore grade from one drill hole, and P 2 (prognosis) resources are based on field observations, field measurements, and an ore grade derived from averaging grades from three better sampled ore bodies. C 2 and P 2 resources are 1,659.1 Mt or about 94% of the total resources in the deposit. The vast P 2 resources have not been drilled or sampled to confirm their extent or quality. The purpose of this article is to independently evaluate the resources of the Haji-Gak iron deposit by using the available geologic and mineral resource information including geologic maps and cross sections, sampling data, and the analog-estimating techniques of the 1960s to determine the size and tenor of the deposit.

Geologic field notes and geochemical analyses of outcrop and drill core from Mesoproterozoic rocks and iron-oxide deposits and prospects of southeast Missouri

Science.gov (United States)

Day, Warren C.; Granitto, Matthew

2014-01-01

The U.S. Geological Survey, in cooperation with the Missouri Department of Natural Resources/Missouri Geological Survey, undertook a study from 1988 to 1994 on the iron-oxide deposits and their host Mesoproterozoic igneous rocks in southeastern Missouri. The project resulted in an improvement of our understanding of the geologic setting, mode of formation, and the composition of many of the known deposits and prospects and the associated rocks of the St. Francois terrane in Missouri. The goal for this earlier work was to allow the comparison of Missouri iron-oxide deposits in context with other iron oxide-copper ± uranium (IOCG) types of mineral deposits observed globally. The raw geochemical analyses were released originally through the USGS National Geochemical Database (NGDB, http://mrdata.usgs.gov). The data presented herein offers all of the field notes, locations, rock descriptions, and geochemical analyses in a coherent package to facilitate new research efforts in IOCG deposit types. The data are provided in both Microsoft Excel (Version Office 2010) spreadsheet format (*.xlsx) and MS-DOS text formats (*.txt) for ease of use by numerous computer programs.

Age-related deposition of brain iron in normal adults: an in vivo susceptibility weighted imaging study

International Nuclear Information System (INIS)

Wang Qidong; Xu Xiaojun; Zhang Minming

2008-01-01

Objective: The purpose of this study was to investigate the effect of age on the iron concentration of the human brain. Methods: The brain iron level was evaluated in vivo in 78 healthy adult volunteers using a noninvasive magnetic resonance method termed susceptibility weighted imaging. The subjects were divided intothree groups due to different ages: young (22-35 years old, n=27), middle- aged (36-55 years old, n=35), and aged (56-78 years old, n=16). The phase values were measured on the corrected phase images in the globus pallidus, putamen, caudate, substantia nigra, red nucleus, thalamus and frontal white matter. The phase values of those regions measured from the subjects over than 30 years old were correlated with published values of brain iron concentration in normal adults to check the validity of the data. Then, the phase values of the three groups were tested for significant age-related differences using one-way ANOVA, followed by post hoc testing using least significant difference (LSD) procedure. Regression analysis was used to further examine age-related effects revealed by group comparisons, and to estimate the rates of age-related changes. Results: A strong negative correlation was found between the phase values and the published values of the brain iron concentration (r=-0.796, P= 0.032), which indicated that the higher the iron deposition level, the greater the negative phase values. In the putamen (F=20.115, P<0.01) and frontal white matter (F=3.536, P=0.034), significant differences were detected in the phase values of the three age groups. Linear regression analysis showed that phase values of the putamen, frontal white matter, and red nucleus decreased with age (The regression coefficients were -0.001, -0.001, and < -0.001 respectively, and the P value were all < 0.05), which indicated that the iron concentration of those brain structures increased with age. No significant age- related changes of the iron concentration were found in the

Iron and manganese deposits in Uruguay; Los yacimientos de hierro y manganeso en el Uruguay

Energy Technology Data Exchange (ETDEWEB)

Alvarado, B

1959-07-01

This report is the results of the study carried out for the United Nations expert which the main object was: the study of the information available about iron and manganese formation in Uruguay, as well as the main researching deposit to determinate economical possibilities in the exportation.

Hepatic MR imaging for in vivo differentiation of steatosis, iron deposition and combined storage disorder: Single-ratio in/opposed phase analysis vs. dual-ratio Dixon discrimination

International Nuclear Information System (INIS)

Bashir, Mustafa R.; Merkle, Elmar M.; Smith, Alastair D.; Boll, Daniel T.

2012-01-01

Objective: To assess whether in vivo dual-ratio Dixon discrimination can improve detection of diffuse liver disease, specifically steatosis, iron deposition and combined disease over traditional single-ratio in/opposed phase analysis. Methods: Seventy-one patients with biopsy-proven (17.7 ± 17.0 days) hepatic steatosis (n = 16), iron deposition (n = 11), combined deposition (n = 3) and neither disease (n = 41) underwent MR examinations. Dual-echo in/opposed-phase MR with Dixon water/fat reconstructions were acquired. Analysis consisted of: (a) single-ratio hepatic region-of-interest (ROI)-based assessment of in/opposed ratios; (b) dual-ratio hepatic ROI assessment of in/opposed and fat/water ratios; (c) computer-aided dual-ratio assessment evaluating all hepatic voxels. Disease-specific thresholds were determined; statistical analyses assessed disease-dependent voxel ratios, based on single-ratio (a) and dual-ratio (b and c) techniques. Results: Single-ratio discrimination succeeded in identifying iron deposition (I/O Ironthreshold Fatthreshold>1.15 ) from normal parenchyma, sensitivity 70.0%; it failed to detect combined disease. Dual-ratio discrimination succeeded in identifying abnormal hepatic parenchyma (F/W Normalthreshold > 0.05), sensitivity 96.7%; logarithmic functions for iron deposition (I/O Iron d iscriminator (0.01−F/W Iron )/0.48 ) and for steatosis (I/O Fatdiscriminator > e (F/W Fat −0.01)/0.48 ) differentiated combined from isolated diseases, sensitivity 100.0%; computer-aided dual-ratio analysis was comparably sensitive but less specific, 90.2% vs. 97.6%. Conclusion: MR two-point-Dixon imaging using dual-ratio post-processing based on in/opposed and fat/water ratios improved in vivo detection of hepatic steatosis, iron deposition, and combined storage disease beyond traditional in/opposed analysis.

Geochemical and iron isotopic insights into hydrothermal iron oxyhydroxide deposit formation at Loihi Seamount

Science.gov (United States)

Rouxel, Olivier; Toner, Brandy; Germain, Yoan; Glazer, Brian

2018-01-01

Low-temperature hydrothermal vents, such as those encountered at Loihi Seamount, harbor abundant microbial communities and provide ideal systems to test hypotheses on biotic versus abiotic formation of hydrous ferric oxide (FeOx) deposits at the seafloor. Hydrothermal activity at Loihi Seamount produces abundant microbial mats associated with rust-colored FeOx deposits and variably encrusted with Mn-oxyhydroxides. Here, we applied Fe isotope systematics together with major and trace element geochemistry to study the formation mechanisms and preservation of such mineralized microbial mats. Iron isotope composition of warm (oxidation of Fe(II) during mixing of the hydrothermal fluid with seawater. By comparing the results with experimentally determined Fe isotope fractionation factors, we determined that less than 20% of Fe(II) is oxidized within active microbial mats, although this number may reach 80% in aged or less active deposits. These results are consistent with Fe(II) oxidation mediated by microbial processes considering the expected slow kinetics of abiotic Fe oxidation in low oxygen bottom water at Loihi Seamount. In contrast, FeOx deposits recovered at extinct sites have distinctly negative Fe-isotope values down to -1.77‰ together with significant enrichment in Mn and occurrence of negative Ce anomalies. These results are best explained by the near-complete oxidation of an isotopically light Fe(II) source produced during the waning stage of hydrothermal activity under more oxidizing conditions. Light Fe isotope values of FeOx are therefore generated by subsurface precipitation of isotopically heavy Fe-oxides rather than by the activity of dissimilatory Fe reduction in the subsurface. Overall, Fe-isotope compositions of microbial mats at Loihi Seamount display a remarkable range between -1.2‰ and +1.6‰ which indicate that Fe isotope compositions of hydrothermal Fe-oxide precipitates are particularly sensitive to local environmental conditions where

Plant cell nucleolus as a hot spot for iron.

Science.gov (United States)

Roschzttardtz, Hannetz; Grillet, Louis; Isaure, Marie-Pierre; Conéjéro, Geneviève; Ortega, Richard; Curie, Catherine; Mari, Stéphane

2011-08-12

Many central metabolic processes require iron as a cofactor and take place in specific subcellular compartments such as the mitochondrion or the chloroplast. Proper iron allocation in the different organelles is thus critical to maintain cell function and integrity. To study the dynamics of iron distribution in plant cells, we have sought to identify the different intracellular iron pools by combining three complementary imaging approaches, histochemistry, micro particle-induced x-ray emission, and synchrotron radiation micro X-ray fluorescence. Pea (Pisum sativum) embryo was used as a model in this study because of its large cell size and high iron content. Histochemical staining with ferrocyanide and diaminobenzidine (Perls/diaminobenzidine) strongly labeled a unique structure in each cell, which co-labeled with the DNA fluorescent stain DAPI, thus corresponding to the nucleus. The unexpected presence of iron in the nucleus was confirmed by elemental imaging using micro particle-induced x-ray emission. X-ray fluorescence on cryo-sectioned embryos further established that, quantitatively, the iron concentration found in the nucleus was higher than in the expected iron-rich organelles such as plastids or vacuoles. Moreover, within the nucleus, iron was particularly accumulated in a subcompartment that was identified as the nucleolus as it was shown to transiently disassemble during cell division. Taken together, our data uncover an as yet unidentified although abundant iron pool in the cell, which is located in the nuclei of healthy, actively dividing plant tissues. This result paves the way for the discovery of a novel cellular function for iron related to nucleus/nucleolus-associated processes.

Magnetic resonance imaging of iron storage diseases

International Nuclear Information System (INIS)

Yoshida, Hideo; Mano, Isamu; Asai, Sae; Yashiro, Naofumi; Itai, Yuji; Iio, Masahiro.

1985-01-01

We presented MRI findings of four patients of iron storage diseases with hemochromatosis and hemosiderosis. We examined detectavility of iron deposits with in vitro MR and X-CT observations of ferric (Fe 3+ ) solutions. Conculusion are as follows, 1) In detection of small amount of iron deposits, MRI is much better than X-CT. 2) MRI is a unique technique to detect iron deposits in bone marrow. 3) Early estimation of iron storage diseases will be promising using MRI technique. (author)

Iron oxi-hydroxides characterization and associated elements (S, Se, As, Mo, V, Zr) in the redox environments favorable for uranium deposits

International Nuclear Information System (INIS)

Pons, Tony

2015-01-01

This work presents a multi-scale and a multi-technical study for the characterization of iron oxi-hydroxides in three uranium-type deposits and host rock. The choice of sites has focused on a roll front deposit: Zoovch Ovoo in a Cretaceous basin of East Gobi (Mongolia); a tectonic-lithological type: Akola/Ebba in Tim Mersoi basin (Niger) and a Proterozoic unconformity type: Kiggavik in Thelon basin (Canada). A new approach has been implemented to characterize the iron oxi-hydroxides on macroscopic samples: field infrared spectroscopy using the ASD TerraSpec spectrometer. From the original indexes calculated on the spectra, it was possible both to characterize the iron oxi-hydroxides; only hematite and goethite were identified in the different parts of oxidized uranium fronts, and visualize the alteration zonation along the redox front. In addition, the visible part of spectrum was used to quantify the color of samples through the IHS system parameters (Intensity - Hue - Saturation) and the Munsell system. The color setting of the study identified a specific hue for mineralized samples studied: a mixture of yellow and red (2.5 to 10 Yr in Munsell notation). At the crystals scale, the iron-hydroxides were characterized by μ-Raman spectroscopy. The study highlighted a difference in crystallinity of hematite crystals in different fields. From a morphological point of view, the crystals of goethite in the Zoovch Ovoo deposit, is only authigenic iron oxi-hydroxides described in this uranium front, are twinned in the form of six-pointed star, reflecting a low crystallization temperature, compared to Niger and Kiggavik deposits. This crystallization is mainly controlled by the availability of Fe(III) ions in the fluid, released by pyrite dissolution in an oxidizing environment and pH. From a chemical point of view, iron oxi-hydroxides record the fluid passage owing their uranium content. Secondly, the composition in trace elements marks the type of deposit, for example

The Effect of Ductile Cast Iron Matrix on Zinc Coating During Hot Dip Galvanising of Castings

Directory of Open Access Journals (Sweden)

D. Kopyciński

2012-12-01

Full Text Available The growth kinetics of the zinc coating formed on the surface of casting made from ductile iron grade EN-GJS-500-3 was investigated. To produce homogenous metal matrix in test samples, the normalising and ferritising annealing was carried out. Studies showeda heterogeneous structure of cast iron with varying content of the phases formed. This was followed by hot dip galvanising treatment at450°C to capture the growth kinetics of the zinc coating (the time of the treatment ranged from 60 to 600 seconds. Nonlinear estimation of the determined growth kinetics of the alloyed layer of a zinc coating was made and an equation of the zinc coating growth was derived.Based on the results of the investigations it was concluded that thickness of the zinc coating formed on the surface of casting with a 100% pearlitic matrix makes 55% of the thickness of coating formed on the surface in 100% ferritic.

The Effect of Ductile Cast Iron Matrix on Zinc Coating During Hot Dip Galvanising of Castings

Directory of Open Access Journals (Sweden)

Kopyciński D.

2012-12-01

Full Text Available The growth kinetics of the zinc coating formed on the surface of casting made from ductile iron grade EN-GJS-500-3 was investigated. To produce homogenous metal matrix in test samples, the normalising and ferritising annealing was carried out. Studies showed a heterogeneous structure of cast iron with varying content of the phases formed. This was followed by hot dip galvanising treatment at 450°C to capture the growth kinetics of the zinc coating (the time of the treatment ranged from 60 to 600 seconds. Nonlinear estimation of the determined growth kinetics of the alloyed layer of a zinc coating was made and an equation of the zinc coating growth was derived. Based on the results of the investigations it was concluded that thickness of the zinc coating formed on the surface of casting with a 100% pearlitic matrix makes 55% of the thickness of coating formed on the surface in 100% ferritic.

Investigation of aluminum and iron deposition on metaplastic bones in three patients with diffuse pulmonary ossification.

Science.gov (United States)

Ohtsuki, Yuji; Mori, Kousuke; Ohnishi, Hirozo; Enzan, Hideaki; Iguchi, Mitsuko; Lee, Gang-Hong; Furihata, Mutsuo

2015-12-01

Diffuse pulmonary ossification (DPO) is a rare pulmonary lesion. DPO is typically detected at autopsy rather than premortem. Recently, however, several cases were diagnosed antemortem using computed tomography, high-resolution computed tomography, or video-assisted thoracic surgery. In the present study, we evaluated DPO at autopsy from two patients with post-myocardial infarction (cases 1 and 3) and one patient with duodenal cancer (case 2). Multiple metaplastic bones (nodular in case 1 and 3 or dendriform in case 2) were detected in these three cases. In an attempt to detect aluminum and iron deposition in these metaplastic bones, histochemical investigations were performed. The two nodular types of one and three cases were positive for aluminum and iron, but the dendriform type of case 2 was positive only for aluminum. The depositions occurred in a linear pattern along the calcifying front. It is of great interest that these deposition patterns were similar to those of bones from three previously reported DPO cases and from the bones of hemodialysis patients. It is suggested that these abnormal metal depositions in the calcifying front might disturb the normal mineralization processes of the metaplastic bones, although no morphological abnormality was detected, except for dense black color of calcifying front lines. Further investigations are needed in more patients with DPO to obtain more information on this topic.

Banded Iron Formations

DEFF Research Database (Denmark)

Posth, Nicole R; Konhauser, Kurt O; Kappler, Andreas

2011-01-01

Sedimentary deposits of alternating iron-rich (20–40% Fe) and iron-poor, siliceous (40–50% SiO2) mineral layers that primarily precipitated throughout much of the late Archean (2.7–2.5 Ga) and Paleoproterozoic (2.5– 1.8 Ga), but then remerged in the Neoproterozoic (0.8 Ga).......Sedimentary deposits of alternating iron-rich (20–40% Fe) and iron-poor, siliceous (40–50% SiO2) mineral layers that primarily precipitated throughout much of the late Archean (2.7–2.5 Ga) and Paleoproterozoic (2.5– 1.8 Ga), but then remerged in the Neoproterozoic (0.8 Ga)....

Liver Iron Contents in Rats after Administration of Certain Iron ...

African Journals Online (AJOL)

The effect of consumption of certain iron compounds on liver iron deposition was ... extra iron probably depends on the type of food prepared, .... main groups. Each main group consisted of 4 subgroups. (8 rats per subgroup) which received the same basic diet but differing amounts of iron of a specific type. Each animal was ...

Magnetite-apatite mineralization in Khanlogh iron deposit, northwest of Neyshaboor, NE Iran

Science.gov (United States)

Najafzadeh Tehrani, Parvin; Asghar Calagari, Ali; Velasco Roldan, Francisco; Simmonds, Vartan; Siahcheshm, Kamal

2016-04-01

Khanlogh iron deposit lies on Sabzehvar-Ghoochan Cenozoic magmatic belt in northwest of Neyshaboor, NE Iran. The lithologic units in this area include a series of sub-volcanic intrusive rocks like diorite porphyry, quartz-diorite porphyry, and micro-granodiorite of Oligocene age. Mineralization in this area occurred as veins, dissemination, and open space filling in brecciated zones within the host sub-volcanic intrusive bodies. Three distinct types of mineral associations can be distinguished, (1) diopside-magnetite, (2) magnetite-apatite, and (3) apatite-calcite. Microscopic examinations along with SEM and EPMA studies demonstrated that magnetite is the most common ore mineral occurring as solitary crystals. The euhedral magnetite crystals are accompanied by lamellar destabilized ilmenite and granular fluorapatite in magnetite-apatite ores. The results of EPMA revealed that the lamellar ilmenite, relative to host magnetite crystal, is notably enriched in MgO and MnO (average of 3.3 and 2.6 wt%, respectively; n=5), whereas magnetite is slighter enriched in Ti (TiO2 around 1.8 wt%) being average of MgO, MnO and V2O3 of 0.6wt%, 0.2wt%, and 0.6 wt% (respectively; n=20). Minerals such as chlorapatite, calcite, and chalcedony are also present in the magnetite-apatite ores. The samples from apatite-calcite ores contain coarse crystals of apatite and rhomboedral calcite. The plot of the EPMA data of Khanlogh iron ore samples on diagram of TiO2-V2O5 (Hou et al, 2011) illustrated that the data points lies between the well-known Kiruna and El Laco (Chile) iron deposits. The magnetite crystals in the sub-volcanic host rocks were possibly formed by immiscible iron oxide fluids during magmatic stage. However, the magnetite and apatite existing in the veins and breccia zones may have developed by high temperature hydrothermal fluids. Studies done by Purtov and Kotelnikova (1993) proved that the proportion of Ti in magnetite is related to fluoride complex in the hydrothermal

FINITE-ELEMENT MODELING OF HOT FORMING OF BUSHES MADE FROM HIGH-STRENGTH CAST IRON WITH A GRADIENT DISTRIBUTION OF GRAPHITE INCLUSIONS OVER CROSS-SECTION

Directory of Open Access Journals (Sweden)

A. I. Pokrovsky

2016-01-01

Full Text Available Imitation modeling of direct hot extrusion of bushes made from high-strength cast iron is performed using finite-element method. The evolution of stress and strain fields during processing and the probability of crack formation are evaluated. The specific feature of the work is that during hot forming a special technique was used which permitted obtaining a gradient distribution of graphite inclusions over the cross-section of bushes. The results of modeling are used in certain technologies which are implemented in industrial practice.

[NIR and XRD analysis of drill-hole samples from Zhamuaobao iron-graphite deposit, Inner Mongolia].

Science.gov (United States)

Li, Ying-kui; Cao, Jian-jin; Wu, Zheng-quan; Dai, Dong-le; Lin, Zu-xu

2015-01-01

The author analyzed the 4202 drill-hole samples from Zhamuaobao iron-graphite deposit by using near infrared spectroscopy(NIR) and X-ray diffraction(XRD) measuring and testing techniques, and then compared and summarized the results of two kinds of testing technology. The results indicate that some difference of the mineral composition exists among different layers, the lithology from upper to deeper is the clay gravel layer of tertiary and quaternary, mudstone, mica quartz schist, quartz actinolite scarn, skarnization marble, iron ore deposits, graphite deposits and mica quartz schist. The petrogenesis in different depth also shows difference, which may indicate the geological characteristic to some extent. The samples had mainly undergone such processes as oxidization, carbonation, chloritization and skarn alteration. The research results can not only improve the geological feature of the mining area, but also have great importance in ore exploration, mining, mineral processing and so on. What's more, as XRD can provide preliminary information about the mineral composition, NIR can make further judgement on the existence of the minerals. The research integrated the advantages of both NIR and XRD measuring and testing techniques, put forward a method with two kinds of modern testing technology combined with each other, which may improve the accuracy of the mineral composition identification. In the meantime, the NIR will be more wildly used in geography on the basis of mineral spectroscopy.

Ferric Iron Precipitation in the Nagahama Bay, Satsuma Iwo-Jima Island, Kagoshima

Science.gov (United States)

Nagata, T.; Kiyokawa, S.; Ikehara, M.; Oguri, K.; Goto, S.; Ito, T.; Yamaguchi, K. E.; Ueshiba, T.

2010-12-01

Satsuma-Iwojima island is active volcanic island and 6 x 3 km in size, located 38km south of Kyushu island, Japan. The reddish brown water along the coast of the Iwo-dake volcano at the center of the island formed by neutralization through mixing of shallow hydrothermal fluid and seawater. The reddish brown water contains reddish ferrihydrite (Fe3+) that is derived from oxidation of Fe2+ from acidic hot spring (Shikaura and Tazaki, 2001). In the Nagahama Bay with its opening to the south, red-colored Fe-rich water is affected by tidal current, but sedimentation of the ferric hydroxide is confirmed to occur in the ocean bottom (Ninomiya and Kiyokawa, 2009). Here we focus other lines of evidence from long term observations and meteorological records as important factor to form thick iron rich sediments. Meteorological and stationary observations: We used weather record in the Satsuma Iwo-jima and cross-checked with stationary observations, which enabled us to observe color changes of the surface of Nagahama Bay. It was made clear that north wind condition in the Nagahama Bay resulted in changes of the color of its surface, from red to green, by intrusion of ocean water coming from outside. Long term temperature monitoring: The temperature of seawater in the Nagahama Bay fluctuated synchronically with the air temperature. But that of hot spring water rather remained constant regardless of the seasonal change. We observed that seawater temperature in the Nagahama Bay is low at high tide and high at low tide, and the rage of temperature change is maximum at the spring tide and minimum at the neap tide. In other words, the amount of discharge of hot spring and that of seawater inflow vary inversely. Core sample: In the Nagahama Bay, iron rich sediments that is more than 1 m thick were identified. The core sample shows lithology as following; upper part, 10-20cm thick, formed loose Fe-rich deposit, lower portion formed alteration of weakly consolidated Fe-rich orange

Trace elements in magnetite from massive iron oxide-apatite deposits indicate a combined formation by igneous and magmatic-hydrothermal processes

Science.gov (United States)

Knipping, Jaayke L.; Bilenker, Laura D.; Simon, Adam C.; Reich, Martin; Barra, Fernando; Deditius, Artur P.; Wälle, Markus; Heinrich, Christoph A.; Holtz, François; Munizaga, Rodrigo

2015-12-01

Iron oxide-apatite (IOA) deposits are an important source of iron and other elements (e.g., REE, P, U, Ag and Co) vital to modern society. However, their formation, including the namesake Kiruna-type IOA deposit (Sweden), remains controversial. Working hypotheses include a purely magmatic origin involving separation of an Fe-, P-rich, volatile-rich oxide melt from a Si-rich silicate melt, and precipitation of magnetite from an aqueous ore fluid, which is either of magmatic-hydrothermal or non-magmatic surface or metamorphic origin. In this study, we focus on the geochemistry of magnetite from the Cretaceous Kiruna-type Los Colorados IOA deposit (∼350 Mt Fe) located in the northern Chilean Iron Belt. Los Colorados has experienced minimal hydrothermal alteration that commonly obscures primary features in IOA deposits. Laser ablation-inductively coupled plasma-mass spectroscopy (LA-ICP-MS) transects and electron probe micro-analyzer (EPMA) wavelength-dispersive X-ray (WDX) spectrometry mapping demonstrate distinct chemical zoning in magnetite grains, wherein cores are enriched in Ti, Al, Mn and Mg. The concentrations of these trace elements in magnetite cores are consistent with igneous magnetite crystallized from a silicate melt, whereas magnetite rims show a pronounced depletion in these elements, consistent with magnetite grown from an Fe-rich magmatic-hydrothermal aqueous fluid. Further, magnetite grains contain polycrystalline inclusions that re-homogenize at magmatic temperatures (>850 °C). Smaller inclusions (500 ppm) concentrations.

Corrosion behaviour of layers obtained by nitrogen implantation into boron films deposited onto iron substrates

International Nuclear Information System (INIS)

Marchetti, F.; Fedrizzi, L.; Giacomozzi, F.; Guzman, L.; Borgese, A.

1985-01-01

The electrochemical behaviour and corrosion resistance of boron films deposited onto Armco iron after bombardment with 100 keV N + ions were determined in various test solutions. The changes in the electrochemical parameters give evidence of lower anodic dissolution rates for the treated samples. Scanning electron microscopy and Auger analysis of the corroded surfaces confirm the presence of protective layers. (Auth.)

Comparison of the mineralogy of the Boss-Bixby, Missouri copper-iron deposit, and the Olympic Dam copper-uranium-gold deposit, South Australia

International Nuclear Information System (INIS)

Brandom, R.T.; Hagni, R.D.; Allen, C.R.

1985-01-01

An ore microscopic examination of 80 polished sections prepared from selected drill core specimens from the Boss-Bixby, Missouri copper-iron deposit has shown that its mineral assemblage is similar to that of the Olympic Dam (Roxby Downs) copper-uranium-gold deposit in South Australia. A comparison with the mineralogy reported for Olympic Dam shows that both deposits contain: 1) the principal minerals, magnetite, hematite, chalcopyrite, and bornite, 2) the cobalt-bearing phases, carrollite and cobaltian pyrite, 3) the titanium oxides, rutile and anatase, 4) smaller amounts of martite, covellite, and electrum, 5) fluorite and carbonates, and 6) some alteration minerals. The deposits also are similar with regard to the sequence of mineral deposition: 1) early oxides, 2) then sulfide minerals, and 3) a final oxide generation. The deposits, however, are dissimilar with regard to their host rock lithologies and structural settings. The Boss-Bixby ores occupy breccia zones within a hydrothermally altered basic intrusive and intruded silicic volcanics, whereas the Olympic Dam ores are contained in sedimentary breccias in a graben or trough. Also, some minerals have been found thus far to occur at only one of the deposits. The similarity of mineralogy in these deposits suggests that they were formed from ore fluids that had some similarities in character and that the St. Francois terrane of Missouri is an important region for further exploration for deposits with this mineral assemblage

Experience in studying of the iron mineralogy in the oxidation zone of uranium deposits by physical methods

International Nuclear Information System (INIS)

Kochenov, A.V.; Dobrovol'skaya, N.V.; Zajtseva, G.M.; Korovushkin, V.V.; Moiseev, V.M.; Yakubovskaya, N.Yu.

1977-01-01

Possibilities are considered of increasing the reliability of the diagnostics and the resolving power of the procedure for the determination of the minaral forms and percentage of iron oxides and hydroxides in the oxidized zone of uranium deposits using a combination of methods of nuclear gamma resonance, thermomagnetic analysis and the Faraday method. The apparatus used included a YaGRS-4 spectrometer in combination with an AI-236 analyzer and a vibration magnetometer. The essence of the methods and of the procedure of analyses is presented. Parameters of reference samples of goethite, maghemite, etc. which emerged from their analysis by the above combination of methods are given. The established diagnostic features have been used in the study of iron mineralogy of oxidized zones, uranium deposits of sedimantarycoal and sandstone types, as well as crusts of weathering of sedimentary rocks. It has been found that in zone of epigenetically altered rocks iron minerals are of mixed multicomponent composition reflecting the fact that the processes of formation of oxidized zones are multistage and not unidirectional in character. The procedure proposed allows one to diagnose finely dispersed, roentgenoamorphous or poorly crystallized minerals, to discover ferruginous minerals in complex multiphase systems and determine their percentages

Synthesis of thick diamond films by direct current hot-cathode plasma chemical vapour deposition

CERN Document Server

Jin Zeng Sun; Bai Yi Zhen; Lu Xian Yi

2002-01-01

The method of direct current hot-cathode plasma chemical vapour deposition has been established. A long-time stable glow discharge at large discharge current and high gas pressure has been achieved by using a hot cathode in the temperature range from 1100 degree C to 1500 degree C and non-symmetrical configuration of the poles, in which the diameter of the cathode is larger than that of anode. High-quality thick diamond films, with a diameter of 40-50 mm and thickness of 0.5-4.2 mm, have been synthesized by this method. Transparent thick diamond films were grown over a range of growth rates between 5-10 mu m/h. Most of the thick diamond films have thermal conductivities of 10-12 W/K centre dot cm. The thick diamond films with high thermal conductivity can be used as a heat sink of semiconducting laser diode array and as a heat spreading and isolation substrate of multichip modules. The performance can be obviously improved

Effects of simulated deposition of acid mist and iron ore particulate matter on photosynthesis and the generation of oxidative stress in Schinus terebinthifolius Radii and Sophora tomentosa L.

Science.gov (United States)

Kuki, Kacilda Naomi; Oliva, Marco Antônio; Pereira, Eduardo Gusmão; Costa, Alan Carlos; Cambraia, José

2008-09-15

Particulate matter is a natural occurrence in the environment, but some industries, such as the iron ore sector, can raise the total amount of particles in the atmosphere. This industry is primarily a source of iron and sulfur dioxide particulates. The effects of the pollutants from the iron ore industries on representatives of restinga vegetation in a Brazilian coastal ecosystem were investigated using physiological and biochemical measures. Two species, Schinus terebinthifolius and Sophora tomentosa, were exposed to simulated deposition of acid mist and iron ore particulate matter in acrylic chambers in a greenhouse. Parameters such as gas exchange, fluorescence emission, chlorophyll content, total iron content, antioxidant enzyme activity and malondialdehyde content were assessed in order to evaluate the responses of the two species. Neither treatment was capable of inducing oxidative stress in S. terebinthifolius. Nevertheless, the deposition of iron ore particulates on this species increased chlorophyll content, the maximum quantum efficiency of photosystem II and the electron transport rate, while iron content was unaltered. On the other hand, S. tomentosa showed a greater sensitivity to the treatments. Plants of S. tomentosa that were exposed to acid mist had a decrease in photosynthesis, while the deposition of iron particulate matter led to an increase in iron content and membrane permeability of the leaves. The activities of antioxidant enzymes, such as catalases and superoxide dismutase, were enhanced by both treatments. The results suggested that the two restinga species use different strategies to overcome the stressful conditions created by the deposition of particulate matter, either solid or wet. It seems that while S. terebinthifolius avoided stress, S. tomentosa used antioxidant enzyme systems to partially neutralize oxidative stress. The findings also point to the potential use of S. tomentosa as a biomarker species under field conditions.

Effects of simulated deposition of acid mist and iron ore particulate matter on photosynthesis and the generation of oxidative stress in Schinus terebinthifolius Radii and Sophora tomentosa L

Energy Technology Data Exchange (ETDEWEB)

Kuki, Kacilda Naomi [Departamento de Biologia Vegetal, Universidade Federal de Vicosa (Brazil)], E-mail: naomikuki@hotmail.com; Oliva, Marco Antonio; Pereira, Eduardo Gusmao; Costa, Alan Carlos [Departamento de Biologia Vegetal, Universidade Federal de Vicosa (Brazil); Cambraia, Jose [Departamento de Biologia Geral, Universidade Federal de Vicosa (Brazil)

2008-09-15

Particulate matter is a natural occurrence in the environment, but some industries, such as the iron ore sector, can raise the total amount of particles in the atmosphere. This industry is primarily a source of iron and sulfur dioxide particulates. The effects of the pollutants from the iron ore industries on representatives of restinga vegetation in a Brazilian coastal ecosystem were investigated using physiological and biochemical measures. Two species, Schinus terebinthifolius and Sophora tomentosa, were exposed to simulated deposition of acid mist and iron ore particulate matter in acrylic chambers in a greenhouse. Parameters such as gas exchange, fluorescence emission, chlorophyll content, total iron content, antioxidant enzyme activity and malondialdehyde content were assessed in order to evaluate the responses of the two species. Neither treatment was capable of inducing oxidative stress in S. terebinthifolius. Nevertheless, the deposition of iron ore particulates on this species increased chlorophyll content, the maximum quantum efficiency of photosystem II and the electron transport rate, while iron content was unaltered. On the other hand, S. tomentosa showed a greater sensitivity to the treatments. Plants of S. tomentosa that were exposed to acid mist had a decrease in photosynthesis, while the deposition of iron particulate matter led to an increase in iron content and membrane permeability of the leaves. The activities of antioxidant enzymes, such as catalases and superoxide dismutase, were enhanced by both treatments. The results suggested that the two restinga species use different strategies to overcome the stressful conditions created by the deposition of particulate matter, either solid or wet. It seems that while S. terebinthifolius avoided stress, S. tomentosa used antioxidant enzyme systems to partially neutralize oxidative stress. The findings also point to the potential use of S. tomentosa as a biomarker species under field conditions.

Effects of simulated deposition of acid mist and iron ore particulate matter on photosynthesis and the generation of oxidative stress in Schinus terebinthifolius Radii and Sophora tomentosa L

International Nuclear Information System (INIS)

Kuki, Kacilda Naomi; Oliva, Marco Antonio; Pereira, Eduardo Gusmao; Costa, Alan Carlos; Cambraia, Jose

2008-01-01

Particulate matter is a natural occurrence in the environment, but some industries, such as the iron ore sector, can raise the total amount of particles in the atmosphere. This industry is primarily a source of iron and sulfur dioxide particulates. The effects of the pollutants from the iron ore industries on representatives of restinga vegetation in a Brazilian coastal ecosystem were investigated using physiological and biochemical measures. Two species, Schinus terebinthifolius and Sophora tomentosa, were exposed to simulated deposition of acid mist and iron ore particulate matter in acrylic chambers in a greenhouse. Parameters such as gas exchange, fluorescence emission, chlorophyll content, total iron content, antioxidant enzyme activity and malondialdehyde content were assessed in order to evaluate the responses of the two species. Neither treatment was capable of inducing oxidative stress in S. terebinthifolius. Nevertheless, the deposition of iron ore particulates on this species increased chlorophyll content, the maximum quantum efficiency of photosystem II and the electron transport rate, while iron content was unaltered. On the other hand, S. tomentosa showed a greater sensitivity to the treatments. Plants of S. tomentosa that were exposed to acid mist had a decrease in photosynthesis, while the deposition of iron particulate matter led to an increase in iron content and membrane permeability of the leaves. The activities of antioxidant enzymes, such as catalases and superoxide dismutase, were enhanced by both treatments. The results suggested that the two restinga species use different strategies to overcome the stressful conditions created by the deposition of particulate matter, either solid or wet. It seems that while S. terebinthifolius avoided stress, S. tomentosa used antioxidant enzyme systems to partially neutralize oxidative stress. The findings also point to the potential use of S. tomentosa as a biomarker species under field conditions

Deposition of a thin electro-polymerized organic film on iron surface

International Nuclear Information System (INIS)

Lecayon, Gerard

1980-01-01

We use an electrochemical method to prepare a polymerized thin film, obtained from acrylonitrile in a solution of acetonitrile and tetraethylammonium perchlorate. The films are deposited on oxidized iron electrodes, with a surface area varying from a few mm to several cm, their thickness ranges from ten A to thousand A. This result is obtained by controlling the evolution of reactions: duplication, hydrogenation, polymerization which occur during the electrochemical reduction of acrylonitrile. The choice of suitable experimental conditions enhances the polymerization and increases the adherence of the polymer on the electrode. The usual methods of surface studies: S.E.M., A.E.S., S.I.M.S., permit the characterization of the electrode surface and the chemical composition of the deposit films. The molecular structure of polymer, and its evolution under aging or heating was studied by infrared multi-reflection spectroscopy. Very good correlation exists between the electrochemical characteristic: I = f(t), the initial surface state of the electrodes, and the homogeneity of the electro-polymerized films. Diagrams corresponding to mechanisms of different stages of electro-polymerization are proposed. (author) [fr

Chemistry of Selected Core Samples, Concentrate, Tailings, and Tailings Pond Waters: Pea Ridge Iron (-Lanthanide-Gold) Deposit, Washington County, Missouri

Science.gov (United States)

Grauch, Richard I.; Verplanck, Philip L.; Seeger, Cheryl M.; Budahn, James R.; Van Gosen, Bradley S.

2010-01-01

The Minerals at Risk and for Emerging Technologies Project of the U.S. Geological Survey (USGS) Mineral Resources Program is examining potential sources of lanthanide elements (rare earth elements) as part of its objective to provide up-to-date geologic information regarding mineral commodities likely to have increased demand in the near term. As part of the examination effort, a short visit was made to the Pea Ridge iron (-lanthanide-gold) deposit, Washington County, Missouri in October 2008. The deposit, currently owned by Wings Enterprises, Inc. of St. Louis, Missouri (Wings), contains concentrations of lanthanides that may be economic as a primary product or as a byproduct of iron ore production. This report tabulates the results of chemical analyses of the Pea Ridge samples and compares rare earth elements contents for world class lanthanide deposits with those of the Pea Ridge deposit. The data presented for the Pea Ridge deposit are preliminary and include some company data that have not been verified by the USGS or by the Missouri Department of Natural Resources, Division of Geology and Land Survey (DGLS), Geological Survey Program (MGS). The inclusion of company data is for comparative purposes only and does not imply an endorsement by either the USGS or MGS.

Direct growth of large grain polycrystalline silicon films on aluminum-induced crystallization seed layer using hot-wire chemical vapor deposition

International Nuclear Information System (INIS)

Wu, Bing-Rui; Lo, Shih-Yung; Wuu, Dong-Sing; Ou, Sin-Liang; Mao, Hsin-Yuan; Wang, Jui-Hao; Horng, Ray-Hua

2012-01-01

Large grain polycrystalline silicon (poly-Si) films on glass substrates have been deposited on an aluminum-induced crystallization (AIC) seed layer using hot-wire chemical vapor deposition (HWCVD). A poly-Si seed layer was first formed by the AIC process and a thicker poly-Si film was subsequently deposited upon the seed layer using HWCVD. The effects of AIC annealing parameters on the structural and electrical properties of the poly-Si seed layers were characterized by Raman scattering spectroscopy, field-emission scanning electron microscopy, and Hall measurements. It was found that the crystallinity of seed layer was enhanced with increasing the annealing duration and temperature. The poly-Si seed layer formed at optimum annealing parameters can reach a grain size of 700 nm, hole concentration of 3.5 × 10 18 cm −3 , and Hall mobility of 22 cm 2 /Vs. After forming the seed layer, poly-Si films with good crystalline quality and high growth rate (> 1 nm/s) can be obtained using HWCVD. These results indicated that the HWCVD-deposited poly-Si film on an AIC seed layer could be a promising candidate for thin-film Si photovoltaic applications. - Highlights: ►Poly-Si seed layers are formed by aluminum-induced crystallization (AIC) process. ►Poly-Si on AIC seed layers are prepared by hot-wire chemical vapor deposition. ►AIC process parameters affect structural properties of poly-Si films. ►Increasing the annealing duration and temperature increases the film crystallinity.

Hot-rolling metals in vacuum. Information circular

International Nuclear Information System (INIS)

Beall, R.A.; Worthington, R.B.; Blickensderfer, R.

1979-01-01

The process of hot-rolling metals, alloys, and composites in vacuum is studied. First, a comprehensive review of the literature is presented, including the advantages and disadvantages of using vacuum. Next, details of hot-rolling titanium, chromium, and molybdenum-iron bimetal are given. Finally, the design of new equipment is described

Corneal iron ring after conductive keratoplasty.

Science.gov (United States)

Kymionis, George D; Naoumidi, Tatiana L; Aslanides, Ioannis M; Pallikaris, Ioannis G

2003-08-01

To report formation of corneal iron ring deposits after conductive keratoplasty. Observational case report. Case report. A 54-year-old woman underwent conductive keratoplasty for hyperopia. One year after conductive keratoplasty, iron ring pattern pigmentation was detected at the corneal epithelium of both eyes. This is the first report of the appearance of corneal iron ring deposits following conductive keratoplasty treatment in a patient. It is suggested that alterations in tear film stability, resulting from conductive keratoplasty-induced changes in corneal curvature, constitute the contributory factor for these deposits.

The effects of metamorphism on iron mineralogy and the iron speciation redox proxy

Science.gov (United States)

Slotznick, Sarah P.; Eiler, John M.; Fischer, Woodward W.

2018-03-01

As the most abundant transition metal in the Earth's crust, iron is a key player in the planetary redox budget. Observations of iron minerals in the sedimentary record have been used to describe atmospheric and aqueous redox environments over the evolution of our planet; the most common method applied is iron speciation, a geochemical sequential extraction method in which proportions of different iron minerals are compared to calibrations from modern sediments to determine water-column redox state. Less is known about how this proxy records information through post-depositional processes, including diagenesis and metamorphism. To get insight into this, we examined how the iron mineral groups/pools (silicates, oxides, sulfides, etc.) and paleoredox proxy interpretations can be affected by known metamorphic processes. Well-known metamorphic reactions occurring in sub-chlorite to kyanite rocks are able to move iron between different iron pools along a range of proxy vectors, potentially affecting paleoredox results. To quantify the effect strength of these reactions, we examined mineralogical and geochemical data from two classic localities where Silurian-Devonian shales, sandstones, and carbonates deposited in a marine sedimentary basin with oxygenated seawater (based on global and local biological constraints) have been regionally metamorphosed from lower-greenschist facies to granulite facies: Waits River and Gile Mountain Formations, Vermont, USA and the Waterville and Sangerville-Vassalboro Formations, Maine, USA. Plotting iron speciation ratios determined for samples from these localities revealed apparent paleoredox conditions of the depositional water column spanning the entire range from oxic to ferruginous (anoxic) to euxinic (anoxic and sulfidic). Pyrrhotite formation in samples highlighted problems within the proxy as iron pool assignment required assumptions about metamorphic reactions and pyrrhotite's identification depended on the extraction techniques

Computer Simulation of Temperature Parameter for Diamond Formation by Using Hot-Filament Chemical Vapor Deposition

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Chang Weon Song

2017-12-01

Full Text Available To optimize the deposition parameters of diamond films, the temperature, pressure, and distance between the filament and the susceptor need to be considered. However, it is difficult to precisely measure and predict the filament and susceptor temperature in relation to the applied power in a hot filament chemical vapor deposition (HF-CVD system. In this study, the temperature distribution inside the system was numerically calculated for the applied powers of 12, 14, 16, and 18 kW. The applied power needed to achieve the appropriate temperature at a constant pressure and other conditions was deduced, and applied to actual experimental depositions. The numerical simulation was conducted using the commercial computational fluent dynamics software ANSYS-FLUENT. To account for radiative heat-transfer in the HF-CVD reactor, the discrete ordinate (DO model was used. The temperatures of the filament surface and the susceptor at different power levels were predicted to be 2512–2802 K and 1076–1198 K, respectively. Based on the numerical calculations, experiments were performed. The simulated temperatures for the filament surface were in good agreement with the experimental temperatures measured using a two-color pyrometer. The results showed that the highest deposition rate and the lowest deposition of non-diamond was obtained at a power of 16 kW.

Magnetic and cytotoxic properties of hot-filament chemical vapour deposited diamond

Energy Technology Data Exchange (ETDEWEB)

Zanin, Hudson, E-mail: hudsonzanin@gmail.com [Faculdade de Engenharia Eletrica e Computacao, Departamento de Semicondutores, Instrumentos e Fotonica, Universidade Estadual de Campinas, UNICAMP, Av. Albert Einstein N.400, CEP 13 083-852 Campinas, Sao Paulo (Brazil); Peterlevitz, Alfredo Carlos; Ceragioli, Helder Jose [Faculdade de Engenharia Eletrica e Computacao, Departamento de Semicondutores, Instrumentos e Fotonica, Universidade Estadual de Campinas, UNICAMP, Av. Albert Einstein N.400, CEP 13 083-852 Campinas, Sao Paulo (Brazil); Rodrigues, Ana Amelia; Belangero, William Dias [Laboratorio de Biomateriais em Ortopedia, Faculdade de Ciencias Medicas, Universidade Estadual de Campinas, Rua Cinco de Junho 350 CEP 13083970, Campinas, Sao Paulo (Brazil); Baranauskas, Vitor [Faculdade de Engenharia Eletrica e Computacao, Departamento de Semicondutores, Instrumentos e Fotonica, Universidade Estadual de Campinas, UNICAMP, Av. Albert Einstein N.400, CEP 13 083-852 Campinas, Sao Paulo (Brazil)

2012-12-01

Microcrystalline (MCD) and nanocrystalline (NCD) magnetic diamond samples were produced by hot-filament chemical vapour deposition (HFCVD) on AISI 316 substrates. Energy Dispersive X-ray Spectroscopy (EDS) measurements indicated the presence of Fe, Cr and Ni in the MCD and NCD samples, and all samples showed similar magnetisation properties. Cell viability tests were realised using Vero cells, a type of fibroblastic cell line. Polystyrene was used as a negative control for toxicity (NCT). The cells were cultured under standard cell culture conditions. The proliferation indicated that these magnetic diamond samples were not cytotoxic. - Highlights: Black-Right-Pointing-Pointer Polycrystalline diamonds doped with Fe, Cr and Ni acquire ferromagnetic properties. Black-Right-Pointing-Pointer CVD diamonds have been prepared with magnetic and semiconductor properties. Black-Right-Pointing-Pointer Micro/nanocrystalline diamonds show good cell viability with fibroblast proliferation.

Composition and microstructure of a furnace ash deposit from a coal-fired utility boiler

Energy Technology Data Exchange (ETDEWEB)

Fessler, R R

1980-07-01

An exploratory study of the structure and composition of furnace-ash deposits was carried out using optical metallography, electron microprobe analysis, scanning electron microscopy, and energy-dispersive X-ray analysis. The results of these analyses were supplemented by studies of particulate melting temperature using hot-stage microscopy to measure melting temperature, and energy-dispersive X-ray analyses to measure composition of melted particles. It was found that the general structure of the ash deposit was a matrix of glassy, spherical particles having a wide range of composition in which unfused particles containing iron oxide and calcium oxide were dispersed. At the imprint of the tube surface a considerable concentration of calcium, sulphur and iron was found. Near the fused outer surface of the deposit, the glassy materials had melted into a porous, glassy slag containing spherical globules of iron oxide combined with other materials. There were no systematic compositional gradients from the tube surface to the fused outer layer except for the sulfur layer found only at the tube surface. However, there were significant differences in composition from particle to particle and these differences were similar to those found in the coal mineral matter as isolated by low-temperature ashing. Single particles of low-temperature ash were found having low fusion temperatures, in the range of fusion temperatures for particles in furnance has. Thus, the glassy spheres found in furnace deposits could originate from single coal particles, without the need of interactions among coal particles or ash particles.

Corneal iron ring after hyperopic photorefractive keratectomy.

Science.gov (United States)

Bilgihan, K; Akata, F; Gürelik, G; Adigüzel, U; Akpinar, M; Hasanreisoğlu, B

1999-05-01

To report the incidence and course of corneal iron deposition after hyperopic photorefractive keratectomy (PRK). Gazi University, Medical School, Department of Ophthalmology, Ankara, Turkey. Between January 1995 and December 1997, 62 eyes had PRK to correct hyperopia. Nine eyes developed corneal iron ring 5 to 8 months (mean 6.25 months +/- 1.3 [SD]) after PRK for hyperopia. The rings persisted during the mean follow-up of 19 +/- 11.09 months. The ring-shaped iron deposition after PRK for hyperopia must be differentiated from the Fleischer ring. Our results suggest that the slitlamp findings of peripheral corneal iron deposition in hyperopic PRK patients correlate with achieved correction.

Characterization and gas-sensing behavior of an iron oxide thin film prepared by atomic layer deposition

International Nuclear Information System (INIS)

Aronniemi, Mikko; Saino, J.; Lahtinen, J.

2008-01-01

In this work we investigate an iron oxide thin film grown with atomic layer deposition for a gas sensor application. The objective is to characterize the structural, chemical, and electrical properties of the film, and to demonstrate its gas-sensitivity. The obtained scanning electron microscopy and atomic force microscopy results indicate that the film has a granular structure and that it has grown mainly on the glass substrate leaving the platinum electrodes uncovered. X-ray diffraction results show that iron oxide is in the α-Fe 2 O 3 (hematite) phase. X-ray photoelectron spectra recorded at elevated temperature imply that the surface iron is mainly in the Fe 3+ state and that oxygen has two chemical states: one corresponding to the lattice oxygen and the other to adsorbed oxygen species. Electric conductivity has an activation energy of 0.3-0.5 eV and almost Ohmic current-voltage dependency. When exposed to O 2 and CO, a typical n-type response is observed

Increased brain iron deposition is a risk factor for brain atrophy in patients with haemodialysis: a combined study of quantitative susceptibility mapping and whole brain volume analysis.

Science.gov (United States)

Chai, Chao; Zhang, Mengjie; Long, Miaomiao; Chu, Zhiqiang; Wang, Tong; Wang, Lijun; Guo, Yu; Yan, Shuo; Haacke, E Mark; Shen, Wen; Xia, Shuang

2015-08-01

To explore the correlation between increased brain iron deposition and brain atrophy in patients with haemodialysis and their correlation with clinical biomarkers and neuropsychological test. Forty two patients with haemodialysis and forty one age- and gender-matched healthy controls were recruited in this prospective study. 3D whole brain high resolution T1WI and susceptibility weighted imaging were scanned on a 3 T MRI system. The brain volume was analyzed using voxel-based morphometry (VBM) in patients and to compare with that of healthy controls. Quantitative susceptibility mapping was used to measure and compare the susceptibility of different structures between patients and healthy controls. Correlation analysis was used to investigate the relationship between the brain volume, iron deposition and neuropsychological scores. Stepwise multiple regression analysis was used to explore the effect of clinical biomarkers on the brain volumes in patients. Compared with healthy controls, patients with haemodialysis showed decreased volume of bilateral putamen and left insular lobe (All P brain iron deposition is negatively correlated with the decreased volume of bilateral putamen (P brain iron deposition and dialysis duration was risk factors for brain atrophy in patients with haemodialysis. The decreased gray matter volume of the left insular lobe was correlated with neurocognitive impairment.

Decontamination of stainless steel covered with radioactive iron oxide deposit using cathodic polarization and ultra-sonic vibration

International Nuclear Information System (INIS)

Sawa, Toshio; Takahashi, Sankichi; Kataoka, Ichiro; Itoh, Hisao.

1985-01-01

The most effective method for reduction of radio activity in BWR nuclear power plants is to remove the iron oxide deposits on cooling pipes. The dissolution behavior of Fe 3 O 4 deposits on the stainless steel were studied in the EDTA solution by means of cathodic polarization and ultra sonic vibration. The dissolution rates of deposits were determined by the decontamination factor (DF) calculated from the radio activity change. Dissolution rate of deposits were dependent on the electrode potential in the less noble range than their rest potentials of stainless steel. The potential at the highest dissolution rate was -1.0 V vs. SCE in the electrolyte at 80 0 C. But the time variation of DF showed that the DF ceased from increasing at some intermediate values. This is perhaps because the current hardly flows to the deposits in a narrow crevice. Therefore, for the dissolution of deposits on stainless steel, it became clear that the successive vibration by ultra-sonic after treating by cathodic polarization is effective. (author)

Effect of Different Catalyst Deposition Technique on Aligned Multiwalled Carbon Nanotubes Grown by Thermal Chemical Vapor Deposition

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Mohamed Shuaib Mohamed Saheed

2014-01-01

Full Text Available The paper reported the investigation of the substrate preparation technique involving deposition of iron catalyst by electron beam evaporation and ferrocene vaporization in order to produce vertically aligned multiwalled carbon nanotubes array needed for fabrication of tailored devices. Prior to the growth at 700°C in ethylene, silicon dioxide coated silicon substrate was prepared by depositing alumina followed by iron using two different methods as described earlier. Characterization analysis revealed that aligned multiwalled carbon nanotubes array of 107.9 µm thickness grown by thermal chemical vapor deposition technique can only be achieved for the sample with iron deposited using ferrocene vaporization. The thick layer of partially oxidized iron film can prevent the deactivation of catalyst and thus is able to sustain the growth. It also increases the rate of permeation of the hydrocarbon gas into the catalyst particles and prevents agglomeration at the growth temperature. Combination of alumina-iron layer provides an efficient growth of high density multiwalled carbon nanotubes array with the steady growth rate of 3.6 µm per minute for the first 12 minutes and dropped by half after 40 minutes. Thicker and uniform iron catalyst film obtained from ferrocene vaporization is attributed to the multidirectional deposition of particles in the gaseous form.

Effect of phosphorus on hot ductility of high purity iron

International Nuclear Information System (INIS)

Abiko, K.; Liu, C.M.; Ichikawa, M..; Suenaga, H.; Tanino, M.

1995-01-01

Tensile tests on high purity Fe-P alloys with 0, 0.05 and 0.1 mass%P were carried out at temperatures between 300 K and 1073 K to clarify the intrinsic effect of phosphorus on the mechanical properties of iron at elevated temperatures. Microstructures of as-quenched, interrupted and ruptured specimens were observed. Experimental results show that the addition of phosphorus causes a remarkable increase in proof stress of high purity iron at 300 K, but the increase in proof stress by phosphorus decreases with increasing test temperature. The strengthening effect of phosphorus reduces to zero at 1073 K. High purity iron and Fe-P alloys rupture at almost 100% reduction in area at the whole test temperatures. However, Fe-P alloys show much larger elongation at test temperatures above 773 K than high purity iron. The increased elongation of high purity iron by addition of phosphorus was shown to be related to the effect of phosphorus on dynamic recovery and recrystallization of iron as its intrinsic effect. (orig.)

General geology, alteration, and iron deposits in the Palaeoproterozoic Misi region, northern Finland

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Tero Niiranen

2003-01-01

characteristic for the entire region. The styles of alteration in the region are: scapolitisation, regional and local albitisation, sericitisation and silicification associated with a major shear zone, and late carbonatisation and carbonate veining associated with brecciation of the ores and their wall rocks. Local intense albitisation and formation of skarnoids and magnetite ores took placeduring the pre-D1 or D1 faulting or shearing which postdate the intrusion of 2120 Ma gabbros. The iron was mobilized from the mafic to intermediate country rocks and/or marble sequence which possibly contained sedimentary iron formation. Regional alteration with the local intense albitisation and ore formation show similar features to the iron oxide-copper-gold type deposits, although the known deposits in the Misi region only contain trace amounts of gold and copper.

A Potential Biomarker in Amyotrophic Lateral Sclerosis: Can Assessment of Brain Iron Deposition with SWI and Corticospinal Tract Degeneration with DTI Help?

Science.gov (United States)

Sheelakumari, R; Madhusoodanan, M; Radhakrishnan, A; Ranjith, G; Thomas, B

2016-02-01

Iron-mediated oxidative stress plays a pivotal role in the pathogenesis of amyotrophic lateral sclerosis. This study aimed to assess iron deposition qualitatively and quantitatively by using SWI and microstructural changes in the corticospinal tract by using DTI in patients with amyotrophic lateral sclerosis. Seventeen patients with amyotrophic lateral sclerosis and 15 age- and sex-matched controls underwent brain MR imaging with SWI and DTI. SWI was analyzed for both signal-intensity scoring and quantitative estimation of iron deposition in the anterior and posterior banks of the motor and sensory cortices and deep gray nuclei. The diffusion measurements along the corticospinal tract at the level of pons and medulla were obtained by ROI analysis. Patients with amyotrophic lateral sclerosis showed reduced signal-intensity grades in the posterior bank of the motor cortex bilaterally. Quantitative analysis confirmed significantly higher iron content in the posterior bank of the motor cortex in patients with amyotrophic lateral sclerosis. In contrast, no significant differences were noted for the anterior bank of the motor cortex, anterior and posterior banks of the sensory cortex, and deep nuclei. Receiver operating characteristic comparison showed a cutoff of 35μg Fe/g of tissue with an area under the curve of 0.78 (P = .008) for the posterior bank of the motor cortex in discriminating patients with amyotrophic lateral sclerosis from controls. Fractional anisotropy was lower in the pyramidal tracts of patients with amyotrophic lateral sclerosis at the pons and medulla on either side, along with higher directionally averaged mean diffusivity values. The combination of SWI and DTI revealed an area under the curve of 0.784 for differentiating patients with amyotrophic lateral sclerosis from controls. Measurements of motor cortex iron deposition and diffusion tensor parameters of the corticospinal tract may be useful biomarkers for the diagnosis of clinically suspected

Influence of substrate material on the microstructure and optical properties of hot wall deposited SnS thin films

International Nuclear Information System (INIS)

Bashkirov, S.A.; Gremenok, V.F.; Ivanov, V.A.; Shevtsova, V.V.; Gladyshev, P.P.

2015-01-01

Tin monosulfide SnS raises an interest as a promising material for photovoltaics. The influence of the substrate material on the microstructure and optical properties of SnS thin films with [111] texture obtained by hot wall vacuum deposition on glass, molybdenum and indium tin oxide substrates is reported. The lattice parameters for layers grown on different substrates were determined by X-ray diffraction and their deviations from the data reported in the literature for single α-SnS crystals were discussed. The change in the degree of preferred orientation of the films depending on the substrate material is observed. The direct nature of the optical transitions with the optical band gap of 1.15 ± 0.01 eV is reported. - Highlights: • SnS thin films were hot wall deposited on glass, molybdenum and indium tin oxide. • Physical properties of the films were studied with respect to the substrate type. • The SnS lattice parameter deviations were observed and the explanation was given. • The direct optical transitions with the band gap of 1.15 ± 0.01 eV were observed

Fabrication and properties of iron-based soft magnetic composites coated with parylene via chemical vapor deposition polymerization

International Nuclear Information System (INIS)

Wu, Shen; Sun, Aizhi; Lu, Zhenwen; Cheng, Chuan

2015-01-01

This paper focuses on novel iron-based soft magnetic composites synthesis utilizing low friction factor parylene C films to coat iron powder via chemical vapor deposition polymerization. The morphology, magnetic properties, density, and chemical stability of parylene insulated iron particles were investigated. The coated parylene insulating layer was characterized by scanning electron microscopy and energy dispersive X-ray spectroscopy. The thickness of parylene C film is averagely 300 nm according to the results of transmission electron microscopy. Parylene C film uniformly coated the powder surface resulting in reducing the permeability imaginary part, increasing electrical resistivity and increasing the operating frequency of the synthesized magnets. It was shown that the parylene C coated compacts exhibited noticeably higher density compared to the epoxy resin coated compacts at the same pressure, suppress at 800 MPa increased the density by 17.02%. The result of Tafel curves indicated that the resistance of the iron particles to corrosion by NaCl solution is obviously improved after being insulated with parylene C film. - Highlights: • Parylene C uniformly coated the powder, increased the operating frequency of SMCs. • Compared with epoxy coated, the density of SMCs increased by 17.02% at 800 MPa. • The resistance of the iron particles is obviously improved with parylene film insulated

Correlations in distribution and concentration of calcium, copper and iron with zinc in isolated extracellular deposits associated with age-related macular degeneration

Science.gov (United States)

Flinn, Jane M; Kakalec, Peter; Tappero, Ryan; Jones, Blair F.; Lengyel, Imre

2014-01-01

Zinc (Zn) is abundantly enriched in sub-retinal pigment epithelial (RPE) deposits, the hallmarks of age-related macular degeneration (AMD), and is thought to play a role in the formation of these deposits. However, it is not known whether Zn is the only metal relevant for sub-RPE deposit formation. Because of their involvement in the pathogenesis of AMD, we determined the concentration and distribution of calcium (Ca), iron (Fe) and copper (Cu) and compared these with Zn in isolated and sectioned macular (MSD), equatorial (PHD) and far peripheral (FPD) sub-RPE deposits from an 86 year old donor eye with post mortem diagnosis of early AMD. The sections were mounted on Zn free microscopy slides and analyzed by microprobe synchrotron X-ray fluorescence (μSXRF). Metal concentrations were determined using spiked sectioned sheep brain matrix standards, prepared the same way as the samples. The heterogeneity of metal distributions was examined using pixel by pixel comparison. The orders of metal concentrations were Ca ⋙ Zn > Fe in all three types of deposits but Cu levels were not distinguishable from background values. Zinc and Ca were consistently present in all deposits but reached highest concentration in MSD. Iron was present in some but not all deposits and was especially enriched in FPD. Correlation analysis indicated considerable variation in metal distribution within and between sub-RPE deposits. The results suggest that Zn and Ca are the most likely contributors to deposit formation especially in MSD, the characteristic risk factor for the development of AMD in the human eye.

Non-LTE line-blanketed model atmospheres of hot stars. 2: Hot, metal-rich white dwarfs

Science.gov (United States)

Lanz, T.; Hubeny, I.

1995-01-01

We present several model atmospheres for a typical hot metal-rich DA white dwarf, T(sub eff) = 60,000 K, log g = 7.5. We consider pure hydrogen models, as well as models with various abundances of two typical 'trace' elements-carbon and iron. We calculte a number of Local Thermodynamic Equilibrium (LTE) and non-LTE models, taking into account the effect of numerous lines of these elements on the atmospheric structure. We demostrate that while the non-LTE effects are notvery significant for pure hydrogen models, except for describing correctly the central emission in H-alpha they are essential for predicting correctly the ionization balance of metals, such as carbon and iron. Previously reported discrepancies in LTE abundances determinations using C III and C IV lines are easily explained by non-LTE effects. We show that if the iron abundance is larger than 10(exp -5), the iron line opacity has to be considered not only for the spectrum synthesis, but also in the model construction itself. For such metal abundances, non-LTE metal line-blanketed models are needed for detailed abundance studies of hot, metal-rich white dwarfs. We also discuss the predicted Extreme Ultraviolet (EUV) spectrum and show that it is very sensitive to metal abundances, as well as to non-LTE effects.

Growth of highly oriented carbon nanotubes by plasma-enhanced hot filament chemical vapor deposition

Energy Technology Data Exchange (ETDEWEB)

Huang, Z.P.; Xu, J.W.; Ren, Z.F.; Wang, J.H. [Materials Synthesis Laboratory, Departments of Physics and Chemistry, and Center for Advanced Photonic and Electronic Materials (CAPEM), State University of New York at Buffalo, Buffalo, New York 14260 (United States); Siegal, M.P.; Provencio, P.N. [Sandia National Laboratories, Albuquerque, New Mexico 87185-1421 (United States)

1998-12-01

Highly oriented, multiwalled carbon nanotubes were grown on polished polycrystalline and single crystal nickel substrates by plasma enhanced hot filament chemical vapor deposition at temperatures below 666 {degree}C. The carbon nanotubes range from 10 to 500 nm in diameter and 0.1 to 50 {mu}m in length depending on growth conditions. Acetylene is used as the carbon source for the growth of the carbon nanotubes and ammonia is used for dilution gas and catalysis. The plasma intensity, acetylene to ammonia gas ratio, and their flow rates, etc. affect the diameters and uniformity of the carbon nanotubes. {copyright} {ital 1998 American Institute of Physics.}

Quantitative measurements of brain iron deposition in cirrhotic patients using susceptibility mapping.

Science.gov (United States)

Xia, Shuang; Zheng, Gang; Shen, Wen; Liu, Saifeng; Zhang, Long Jiang; Haacke, E Mark; Lu, Guang Ming

2015-03-01

Susceptibility-weighted imaging (SWI) has been used to detect micro-bleeds and iron deposits in the brain. However, no reports have been published on the application of SWI in studying iron changes in the brain of cirrhotic patients. To compare the susceptibility of different brain structures in cirrhotic patients with that in healthy controls and to evaluate susceptibility as a potential biomarker and correlate the measured susceptibility and cadaveric brain iron concentration for a variety of brain structures. Forty-three cirrhotic patients (27 men, 16 women; mean age, 50 ± 9 years) and 34 age- and sex-matched healthy controls (22 men, 12 women; mean age, 47 ± 7 years) were included in this retrospective study. Susceptibility was measured in the frontal white matter, basal ganglia, midbrain, and dentate nucleus and compared with results gathered from two postmortem brain studies. Correlation between susceptibility and clinical biomarkers and neuropsychiatric tests scores was calculated. In cirrhotic patients, the susceptibility of left frontal white matter, bilateral caudate head, and right substantia nigra was higher than that in healthy controls (P brain study (r = 0.835, P = 0.01) in eight deep grey matter structures and another in five brain structures (r = 0.900, P = 0.03). The susceptibility of right caudate head (r = 0.402) and left caudate head (r = 0.408) correlated with neuropsychological test scores (both P brain regions appears to reflect neurocognitive changes. © The Foundation Acta Radiologica 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Calcium channel blockers ameliorate iron overload-associated hepatic fibrosis by altering iron transport and stellate cell apoptosis

Energy Technology Data Exchange (ETDEWEB)

Zhang, Ying [Department of Pharmacology, Hebei University of Chinese Medicine, Shijiazhuang 050200, Hebei (China); Department of Pathology, Hebei University of Chinese Medicine, Shijiazhuang 050200, Hebei (China); Hebei Key Laboratory of Chinese Medicine Research on Cardio-Cerebrovascular Disease, Shijiazhuang 050200, Hebei (China); Zhao, Xin [Department of Hepatobiliary Surgery, The Third Hospital of Hebei Medical University, Shijiazhuang 050051, Hebei (China); Chang, Yanzhong [Laboratory of Molecular Iron Metabolism, College of Life Science, Hebei Normal University, Shijiazhuang 050024, Hebei (China); Zhang, Yuanyuan [Department of Pharmacology, Hebei University of Chinese Medicine, Shijiazhuang 050200, Hebei (China); Chu, Xi [Department of Pharmacy, The Forth Hospital of Hebei Medical University, Shijiazhuang 050011, Hebei (China); Zhang, Xuan [Department of Pharmacology, Hebei University of Chinese Medicine, Shijiazhuang 050200, Hebei (China); Liu, Zhenyi; Guo, Hui [Department of Medicinal Chemistry, Hebei University of Chinese Medicine, Shijiazhuang 050200, Hebei (China); Wang, Na [Department of Physiology, Hebei University of Chinese Medicine, Shijiazhuang 050200, Hebei (China); Gao, Yonggang [Department of Pharmacology, Hebei University of Chinese Medicine, Shijiazhuang 050200, Hebei (China); Zhang, Jianping, E-mail: zhangjianping14@126.com [Department of Pharmacology, Hebei University of Chinese Medicine, Shijiazhuang 050200, Hebei (China); Chu, Li, E-mail: chuli0614@126.com [Department of Pharmacology, Hebei University of Chinese Medicine, Shijiazhuang 050200, Hebei (China); Hebei Key Laboratory of Integrative Medicine on Liver-Kidney Patterns, Shijiazhuang 050200, Hebei (China)

2016-06-15

Liver fibrosis is the principal cause of morbidity and mortality in patients with iron overload. Calcium channel blockers (CCBs) can antagonize divalent cation entry into renal and myocardial cells and inhibit fibrogenic gene expression. We investigated the potential of CCBs to resolve iron overload-associated hepatic fibrosis. Kunming mice were assigned to nine groups (n = 8 per group): control, iron overload, deferoxamine, high and low dose verapamil, high and low dose nimodipine, and high and low dose diltiazem. Iron deposition and hepatic fibrosis were measured in mouse livers. Expression levels of molecules associated with transmembrane iron transport were determined by molecular biology approaches. In vitro HSC-T6 cells were randomized into nine groups (the same groups as the mice). Changes in proliferation, apoptosis, and metalloproteinase expression in cells were detected to assess the anti-fibrotic effects of CCBs during iron overload conditions. We found that CCBs reduced hepatic iron content, intracellular iron deposition, the number of hepatic fibrotic areas, collagen expression levels, and hydroxyproline content. CCBs rescued abnormal expression of α1C protein in L-type voltage-dependent calcium channel (LVDCC) and down-regulated divalent metal transporter-1 (DMT-1) expression in mouse livers. In iron-overloaded HSC-T6 cells, CCBs reduced iron deposition, inhibited proliferation, induced apoptosis, and elevated expression of matrix metalloproteinase-13 (MMP-13) and tissue inhibitor of metalloproteinase-1 (TIMP-1). CCBs are potential therapeutic agents that can be used to address hepatic fibrosis during iron overload. They resolve hepatic fibrosis probably correlated with regulating transmembrane iron transport and inhibiting HSC growth. - Highlights: • Calcium channel blockers (CCBs) reduced hepatic iron content. • CCBs decreased hepatic fibrotic areas and collagen expression levels. • CCBs resolve fibrosis by regulating iron transport and

Diffusion Coefficient in the Zinc Coating Shaped on the Surface of Cast Iron and Steel Alloys

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Kopyciński D.

2015-06-01

Full Text Available The article presents the method to assess the diffusion coefficient D in the sub-layer of intermetallic phases formed during hot-dip galvanizing “Armco” iron and ductile cast iron EN-GJS-500-7. Hot-dip galvanizing is one of the most popular forms of long-term protection of Fe-C alloys against corrosion. The process for producing a protective layer of sufficient quality is closely related to diffusion of atoms of zinc and iron. The simulation consist in performed a hot-dip galvanizing in laboratory condition above Fe-C alloys, in the Department of Engineering of Cast Alloys and Composites. Galvanizing time ranged from 15 to 300 seconds. Then metallographic specimens were prepared, intermetallic layers were measured and diffusion coefficient (D were calculated. It was found that the diffusion coefficient obtained during hot-dip galvanizing “Armco” iron and zinc is about two orders of magnitude less than the coefficient obtained on ductile cast iron EN-GJS-500-7.

Iron deposition of the deep grey matter in patients with multiple sclerosis and neuromyelitis optica: A control quantitative study by 3D-enhanced susceptibility-weighted angiography (ESWAN)

International Nuclear Information System (INIS)

Chen Xuan; Zeng Chun; Luo Tianyou; Ouyang Yu; Lv Fajin; Rumzan, Reshiana; Wang Zhongping; Li Qi; Wang Jingjie; Hou Huanxin

2012-01-01

Purpose: Previous studies have detected abnormal iron deposition in the deep grey matter (DGM) of multiple sclerosis (MS). The regional specificity of the DGM iron deposition in neuromyelitis optica (NMO) is still unclear. We compared the differences in the DGM iron concentration between MS and NMO patients. Methods: We enrolled 42 relapsing–remitting MS (RRMS) patients, 42 NMO patients and 42 healthy controls undergoing brain conventional MRI and three-dimensional (3D)-enhanced T 2 *-weighted angiography (ESWAN) sequences. We obtained the mean phase values (MPVs) for ESWAN-filtered phase images. An analysis of covariance (ANCOVA) was used to compare MPVs among three groups. The correlations of MPVs changes with disease duration and expanded disability status scale (EDSS) were analyzed. Results: The RRMS patients had higher DGM iron concentration than did the NMO and control groups, but only the bilateral substantia nigra (SN) showed a significant statistical difference among three groups (p 0.05). Furthermore, no correlations were found between the DGM iron concentration and EDSS (p > 0.05). Conclusions: We confirm the iron concentration in the DGM iron content of MS patients is more than NMO patients and healthy controls in the same age range. Furthermore, the disease duration was found to be a significant contributor to patients with MS.

A genetic link between magnetite mineralization and diorite intrusion at the El Romeral iron oxide-apatite deposit, northern Chile

Science.gov (United States)

Rojas, Paula A.; Barra, Fernando; Reich, Martin; Deditius, Artur; Simon, Adam; Uribe, Francisco; Romero, Rurik; Rojo, Mario

2018-01-01

El Romeral is one of the largest iron oxide-apatite (IOA) deposits in the Coastal Cordillera of northern Chile. The Cerro Principal magnetite ore body at El Romeral comprises massive magnetite intergrown with actinolite, with minor apatite, scapolite, and sulfides (pyrite ± chalcopyrite). Several generations of magnetite were identified by using a combination of optical and electron microscopy techniques. The main mineralization event is represented by zoned magnetite grains with inclusion-rich cores and inclusion-poor rims, which form the massive magnetite ore body. This main magnetite stage was followed by two late hydrothermal events that are represented by magnetite veinlets that crosscut the massive ore body and by disseminated magnetite in the andesite host rock and in the Romeral diorite. The sulfur stable isotope signature of the late hydrothermal sulfides indicates a magmatic origin for sulfur (δ34S between - 0.8 and 2.9‰), in agreement with previous δ34S data reported for other Chilean IOA and iron oxide-copper-gold deposits. New 40Ar/39Ar dating of actinolite associated with the main magnetite ore stage yielded ages of ca. 128 Ma, concordant within error with a U-Pb zircon age for the Romeral diorite (129.0 ± 0.9 Ma; mean square weighted deviation = 1.9, n = 28). The late hydrothermal magnetite-biotite mineralization is constrained at ca. 118 Ma by 40Ar/39Ar dating of secondary biotite. This potassic alteration is about 10 Ma younger than the main mineralization episode, and it may be related to post-mineralization dikes that crosscut and remobilize Fe from the main magnetite ore body. These data reveal a clear genetic association between magnetite ore formation, sulfide mineralization, and the diorite intrusion at El Romeral (at 129 Ma), followed by a late and more restricted stage of hydrothermal alteration associated with the emplacement of post-ore dikes at ca. 118 Ma. Therefore, this new evidence supports a magmatic-hydrothermal model for the

Synthesis of iron oxides nanoparticles with very high saturation magnetization form TEA-Fe(III) complex via electrochemical deposition for supercapacitor applications

Science.gov (United States)

Elrouby, Mahmoud; Abdel-Mawgoud, A. M.; El-Rahman, Rehab Abd

2017-11-01

This work is devoted to the synthesis of magnetic iron oxides nanoparticles with very high saturation magnetization to be qualified for supercapacitor applications using, a simple electrodeposition technique. It is found that the electrochemical reduction process depends on concentration, temperature, deposition potential and the scan rate of potential. The nature of electrodeposition process has been characterized via voltammetric and chronoamperometric techniques. The morphology of the electrodeposits has been investigated using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The structure and phase content of these investigated electrodeposits have been examined and calculated. The obtained iron oxides show a high saturation magnetization (Ms) of about 229 emu g-1. The data exhibited a relation between Ms of electrodeposited iron oxide and specific capacitance. This relation exhibits that the highest Ms value of electrodeposited iron oxides gives also highest specific capacitance of about 725 Fg-1. Moreover, the electrodeposited iron oxides exhibit a very good stability. The new characteristics of the electro synthesized iron oxides at our optimized conditions, strongly qualify them as a valuable material for high-performance supercapacitor applications.

Early detection of injuries in leaves of Clusia hilariana Schltdl. (Clusiaceae caused by particulate deposition of iron

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Diego Ismael Rocha

2014-06-01

Full Text Available This study aims to evaluate the prognostic value of microscopic parameters of asymptomatic leaves of Clusia hilariana Schltdl. subjected to particulate deposition of iron (2.14 mg cm-2 day-1 for 45 consecutive days. Samples of young and expanded leaves without symptoms were collected and subjected to light and scanning electron microscopy techniques. The height of the epidermal cells on both surfaces of the leaf and the thickness of the hypodermis, the chlorophyll parenchyma, and the leaf blade were measured. Micromorphological injury occurred in the abaxial surface of young leaves and on both surfaces of expanded leaves. Erosion of the epicuticular wax and cuticle rupture were frequent on the adaxial surface, while on the abaxial surface of both leaves there was a loss of sinuosity on the anticlinal wall of the epidermal cells, stomatal deformity and obstruction. Micromorphometric alterations were seen in all leaf tissues except in the height of epidermic cells, probably due to the thick cuticle and prominent cuticular flanges. The highest difference in thickness of the leaf blade was seen in young leaves of plants subjected to SPMFe, indicating greater sensibility to particulate iron in comparison to the expanded leaves. The micromorphological and micromorphometric alterations in the leaf blade of Clusia hilariana Schltdl. showed the prognostic potential of these tools on the evaluation of impacts caused by the deposition of particulate matter, especially in the 'Restinga' natural vegetation, where the exposure is increasing due to the presence of iron ore industry in their surroundings.

Trace Element Geochemistry of Magnetite and Accesory Phases from El Romeral Iron Oxide-Apatite Deposit, Northern Chile

Science.gov (United States)

Barra, F.; Rojas, P.; Reich, M.; Deditius, A.; Simon, A. C.

2017-12-01

Iron oxide-apatite (IOA) or "Kiruna-type" deposits are an important source of Fe, P, REE, among other essential elements for society. Three main hypotheses have been proposed to explain the genesis of these controversial deposits, which invoke liquid immiscibility, hydrothermal replacement or a magmatic-hydrothermal origin driven by flotation of magnetite-bubble pairs. Here we focus on the El Romeral, one of the largest IOA deposits located in the southernmost part of the Cretaceous Chilean Iron Belt. We combined SEM observations and EMPA analyses of magnetite, actinolite, pyrite, and apatite, with micro-Raman determinations of mineral inclusions within magnetite grains. Two textural types of magnetite were identified at El Romeral: (i) inclusion-rich magnetite (Mag I), and (ii) inclusion-poor magnetite (Mag II) that are commonly surrounding the inclusion-rich Mag I grains. Mag I is characterized by high V ( 2500-2800 ppm) and Ti (300-1000 ppm) contents with high-temperature mineral inclusions such as ilmenite, Ti-pargasite and clinochlore at depth, and quartz and phlogopite inclusions in shallower samples. These characteristics are consistent with a magmatic origin for Mag I. Inclusion-poor magnetite (Mag II) have high V (2400-2600 ppm) and lower Ti (70-200 ppm) contents than Mag I, which point to chemical changes of the mineralizing fluid(s). An increase in thermal gradient with depth is evidenced by the presence of high-temperature (low #Fe) actinolite, as well as F-rich apatite and pyrite with high Co:Ni (>1) in the deep zones. In contrast, lower Co:Ni ratios (<0.5) in pyrite and higher Cl contents in OH-rich apatite are detected in samples from shallower levels. This vertical chemical variation supports a magmatic-hydrothermal origin for the El Romeral deposit, and point to compositional changes driven by decompression of a magnetite-fluid suspension.

Hot wire chemical vapor deposition: limits and opportunities of protecting the tungsten catalyzer from silicide with a cavity

International Nuclear Information System (INIS)

Frigeri, P.A.; Nos, O.; Bengoechea, S.; Frevert, C.; Asensi, J.M.; Bertomeu, J.

2009-01-01

Hot Wire Chemical Vapor Deposition (HW-CVD) is one of the most promising techniques for depositing the intrinsic microcrystalline silicon layer for the production of micro-morph solar cells. However, the silicide formation at the colder ends of the tungsten wire drastically reduces the lifetime of the catalyzer, thus limiting its industrial exploitation. A simple but interesting strategy to decrease the silicide formation is to hide the electrical contacts of the catalyzer in a long narrow cavity which reduces the probability of the silane molecules to reach the colder ends of the wire. In this paper, the working mechanism of the cavity is elucidated. Measurements of the thickness profile of the silicon deposited in the internal walls of the cavity have been compared with those predicted using a simple diffusion model based on the assumption of Knudsen flow. A lifetime study of the protected and unprotected wires has been carried out. The different mechanisms which determine the deterioration of the catalyzer have been identified and discussed.

Microstructure and wear behaviors of WC–12%Co coating deposited on ductile iron by electric contact surface strengthening

International Nuclear Information System (INIS)

Qi, Xiaoben; Zhu, Shigen; Ding, Hao; Zhu, Zhengkun; Han, Zhibing

2013-01-01

WC–12%Co powders deposited on ductile iron by electric contact strengthening were studied. This technology was based on the application of the contact resistance heating between the electrode and work piece to form a wear resistant layer on ductile iron. The microstructure, microhardness distribution, phase transformation and wear behaviors of the coating were investigated using optical microscope, scanning electron microscope, Vickers hardness (HV 0.5 ), X-ray diffraction, rolling contact wear tests. The results showed that the WC–12%Co coating by electric contact strengthening was metallurgically bonded to the ductile iron. Additionally, the effect of experimental parameters on microhardness and wear resistance of coatings were studied using orthogonal experiment. The results showed that compared with (A) electric current and (B) rotating speed, (C) contact force displays the most significant effect on microhardness and wear resistance of coatings. The coatings produced at A = 19 kA, B = 0.3 r/min and C = 700 N possessed highest microhardness of 1073 HV 0.5 and wear resistance.

Iron deposition in the precentral grey matter in patients with multiple sclerosis: A quantitative study using susceptibility-weighted imaging

Energy Technology Data Exchange (ETDEWEB)

Rumzan, Reshiana, E-mail: minouchka_16@yahoo.com [Department of Radiology, The First Affiliated Hospital of Chongqing Medical University, No. 1 Youyi Road, Yuzhong District, Chongqing 400016 (China); Wang, Jing-jie, E-mail: jingjiewang@126.com [Department of Radiology, The First Affiliated Hospital of Chongqing Medical University, No. 1 Youyi Road, Yuzhong District, Chongqing 400016 (China); Zeng, Chun, E-mail: zengchun19840305@163.com [Department of Radiology, The First Affiliated Hospital of Chongqing Medical University, No. 1 Youyi Road, Yuzhong District, Chongqing 400016 (China); Chen, Xuan, E-mail: martha860831@sina.com [Department of Imaging, The Second People' s Hospital of Sichuan, 55 Renmin South Road, Chengdu 610041 (China); Li, Yongmei, E-mail: lymzhang70@yahoo.com.cn [Department of Radiology, The First Affiliated Hospital of Chongqing Medical University, No. 1 Youyi Road, Yuzhong District, Chongqing 400016 (China); Luo, Tianyou, E-mail: ltychy@sina.com [Department of Radiology, The First Affiliated Hospital of Chongqing Medical University, No. 1 Youyi Road, Yuzhong District, Chongqing 400016 (China); Lv, Fajin, E-mail: fajinlv@hotmail.com [Department of Radiology, The First Affiliated Hospital of Chongqing Medical University, No. 1 Youyi Road, Yuzhong District, Chongqing 400016 (China); Wang, Zhong-ping, E-mail: wzp20551015@126.com [Department of Radiology, The First Affiliated Hospital of Chongqing Medical University, No. 1 Youyi Road, Yuzhong District, Chongqing 400016 (China); Hou, Huanxin, E-mail: newt948@foxmail.com [Department of Radiology, The First Affiliated Hospital of Chongqing Medical University, No. 1 Youyi Road, Yuzhong District, Chongqing 400016 (China); Huang, Fuhong, E-mail: fuhonghuang@163.com [Department of Radiology, The First Affiliated Hospital of Chongqing Medical University, No. 1 Youyi Road, Yuzhong District, Chongqing 400016 (China)

2013-02-15

Purpose: Several studies suggest that iron deposition may play a role in multiple sclerosis (MS) pathology. Three-dimensional (3D) enhanced T2*-weighted angiography (ESWAN) at 3T was used to quantify iron deposition in the precentral grey matter in MS and its relationship with disease duration, atrophy and Expanded Disability Status Scale (EDSS) scores. Methods: We recruited 33 patients with diagnosis of clinically definite MS and 31 age- and sex-matched healthy controls who underwent conventional brain MRI, 3D-ESWAN and 3D T1sequences. We obtained the mean phase values (MPVs) of the precentral grey matter on ESWAN-filtered phase images and volume of the precentral gyrus on 3D T1 images. We investigated the correlation between precentral grey matter MPVs, precentral gyrus volume, disease duration and EDSS scores of MS patients and healthy controls. Results: The precentral grey matter MPVs in MS patients and controls were 1870.83 ± 56.61 and 1899.22 ± 51.73 respectively and had significant difference in the MS group vs. the control group (t = −2.09, P = 0.04). There was significant negative correlation between precentral grey matter MPVs and disease duration (r = −0.365, P = 0.03). No correlation was found between MPVs and EDSS scores. Mean precentral gyrus volume in MS patients was 4368.55 ± 867.78 whereas in controls was 5701.00 ± 1184.03 with significant difference between volume of the precentral gyrus in MS patients compared to healthy controls (t = −5.167, P < 0.001). There was a positive correlation between MPVs and precentral gyrus volume (r = 0.291, P = 0.020). Conclusions: Our study demonstrated that quantitative assessment of abnormal iron deposition in the precentral grey matter in MS patients can be measured using 3D-ESWAN.

Carbon materials as new nanovehicles in hot-melt drug deposition

International Nuclear Information System (INIS)

Bielicka, Agnieszka; Wiśniewski, Marek; Terzyk, Artur P; Gauden, Piotr A; Furmaniak, Sylwester; Bieniek, A; Roszek, Katarzyna; Kowalczyk, Piotr

2013-01-01

The application of commercially available carbon materials (nanotubes and porous carbons) for the preparation of drug delivery systems is studied. We used two types of carbon nanotubes (CNT) and two activated carbons as potential materials in so-called hot-melt drug deposition (HMDD). The materials were first studied using Raman spectroscopy. Paracetamol was chosen as a model drug. The performed thermal analysis, kinetics, and adsorption–desorption studies revealed that nanoaggregates are formed between carbon nanotubes. In contrast, in pores of activated carbon we do not observe this process and the drug adsorption phenomenon mechanism is simply the filling of small pores. The formation of nanoaggregates was confirmed by the results of GCMC (grand canonical Monte Carlo) simulations and the study of the surface area on nitrogen adsorption–desorption isotherms. The application of carbon nanotubes in HMDD offers the possibility of controlling the rate of drug delivery. Performed MTT tests of nanotubes and drug-loaded nanotubes show that the observed decrease in cell viability number is caused by the influence of the cytostatic properties of nanotubes—they inhibit the proliferation of cells. The carbon nanotubes studied in this paper are essentially nontoxic. (paper)

Effects of atmospheric gas composition and temperature on the gasification of coal in hot briquetting carbon composite iron ore

Energy Technology Data Exchange (ETDEWEB)

Ueki, Y.; Kanayama, M.; Maeda, T.; Nishika, K.; Shimizu, M. [Kyushu University, Fukuoka (Japan). Dept. of Materials Science & Engineering

2007-01-15

The gasification behavior of carbon composite iron ore produced by hot briquetting process was examined under various gas atmospheres such as CO-N{sub 2}, CO{sub 2}-N, and CO-CO{sub 2} at various temperatures. The gasification of coal was affected strongly by atmospheric gas concentration and reaction temperature. Kinetic analysis in various gas atmospheres was carried out by using the first order reaction model, which yields the straight line relation between reaction rate constants for the gasification of coal and the gas concentration. Therefore, reaction rate constants for the gasification of coal in CO-CO{sub 2}-N{sub 2} gas atmosphere were derived.

Study of iron deposit using seismic refraction and resistivity in Carajás Mineral Province, Brazil

Science.gov (United States)

Nogueira, Pedro Vencovsky; Rocha, Marcelo Peres; Borges, Welitom Rodrigues; Silva, Adalene Moreira; Assis, Luciano Mozer de

2016-10-01

This work comprises the acquisition, processing and interpretation of 2D seismic shallow refraction (P-wave) and resistivity profiles located in the iron ore deposit of N4WS, Carajás Mineral Province (CMP), northern Brazil. The geophysical methods were used to identify the boundaries of the iron ore deposit. Another objective was to evaluate the potentiality of these geophysical methods in that geological context. In order to validate the results, the geophysical lines were located to match a geological borehole line. For the seismic refraction, we used 120 channels, spaced by 10 m, in a line of 1190 m, with seven shot points. The resistivity method used in the acquisition was the electrical resistivity imaging, with pole-pole array, in order to reach greater depths. The resistivity line had a length of 1430 m, with 10 m spacing between electrodes. The seismic results produced a model with two distinct layers. Based on the velocities values, the first layer was interpreted as altered rocks, and the second layer as more preserved rocks. It was not possible to discriminate different lithologies with the seismic method inside each layer. From the resistivity results, a zone of higher resistivity (> 3937 Ω·m) was interpreted as iron ore, and a region of intermediate resistivity (from 816 to 2330 Ω·m) as altered rocks. These two regions represent the first seismic layer. On the second seismic layer, an area with intermediated resistivity values (from 483 to 2330 Ω·m) was interpreted as mafic rocks, and the area with lower resistivity (boreholes and show reasonable correlation, suggesting that the geophysical anomalies correspond to the main variations in composition and physical properties of rocks.

Sedimentology and geochemistry of early Proterozoic storm-dominated deposits in the transition zone from microbanded Kuruman to granular Griquatown iron-formation, Griqualand West

International Nuclear Information System (INIS)

Beukes, N.J.; Klein, C.

1990-01-01

A transition from microbanded Kuruman to granular Griquatown iron-formation is described in terms of sedimentological, petrographic, and geochemical characteristics, as well as whole rock carbon and oxygen isotopic compositions. Five major lithofacies are present in the Kuruman-Griquatown transition zone. The lithofacies are arranged in an upward coarsening sequence. It is concluded that the coarsening upward microbanded-granular iron-formation units in the Kuruman-Griquatown sequence represent shallowing upward storm-dominated deposits. 2 refs

Mineralogy and electron microprobe studies of magnetite in the Sarab-3 iron Ore deposit, southwest of the Shahrak mining region (east Takab

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Mohammad Maanijou

2018-04-01

Full Text Available Introduction There is an iron mining complex called Shahrak 60 km east of the Takab town, NW Iran. The exploration in the Shahrak deposit (general name for all iron deposits of the area started in 1992 by the Foolad Saba Noor Co. and continued in several periods until 2008. The Shahrak deposit is comprised of 10 ore deposits including Sarab-1, Sarab-2, Sarab-3, Korkora-1, Korkora-2, Shahrak-1, Shahrak-2, Shahrak-3, Cheshmeh and Golezar deposits (Sheikhi, 1995 with a total 60 million tons of proven ore reserves. The Fe grade ranges from 45 to 65% (average 50%. The ore reserves of these deposits are different. Sarab-3 ore deposit with 9 million tons of 54% Fe and 8.95% S is located at the northeast of Kurdistan and in the Sanandaj-Sirjan structural zone at the latitude of 36°20´ and longitude of 47°32´. Materials and methods Sixty thin-polished, polished and thin sections are made for the study of mineralogy and petrology, and among them six thin-polished sections were selected for EPMA (Electron Probe Micro Analysis on magnetite and hematite. EPMA was performed using the Cameca Sx100 electron microprobe at the Iran Mineral Processing Research Center (IMPRC with wavelength-dispersive spectrometers. Results and discussion Based on field observations and petrographic studies, lithologic composition of intrusion (Miocene age ranges within the diorite-leucodiorite, monzodiorite-quartz monzodiorite, granodiorite-granite. With the intrusion of those igneous bodies into carbonate rocks of the Qom Formation, contact metamorphism was formed. The formation of Sarab-3 iron deposit occurred at the three stages of metamorphism, skarnification and supergene. Based on field geology of the deposit, it is composed of endoskarn, exoskarn including Fe ore±sulfides. At the metamorphic stage, after intrusion of intrusive bodies in carbonate rocks, recrystallization took place and marble was formed. With more crystallization of magma, evolved hydrothermal fluids

Growth and characterization of yttrium iron garnet films on Si substrates by Chemical Solution Deposition (CSD) technique

Energy Technology Data Exchange (ETDEWEB)

Guo, Xin; Chen, Ying; Wang, Genshui [Key Laboratory of Inorganic Function Materials and Devices, Shanghai Institute of Ceramics, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 1295 Dingxi Rd., Shanghai 200050 (China); Zhang, Yuanyuan [Key Laboratory of Polar Materials and Devices, Ministry of Education, Department of Electronic Engineering, East China Normal University, 500 Dongchuan Rd., Shanghai 200241 (China); Ge, Jun [Key Laboratory of Inorganic Function Materials and Devices, Shanghai Institute of Ceramics, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 1295 Dingxi Rd., Shanghai 200050 (China); Tang, Xiaodong [Key Laboratory of Polar Materials and Devices, Ministry of Education, Department of Electronic Engineering, East China Normal University, 500 Dongchuan Rd., Shanghai 200241 (China); Ponchel, Freddy; Rémiens, Denis [Institute of Electronics, Microelectronics and Nanotechnology (IEMN)–DOAE, UMR CNRS 8520, Université des Sciences et Technologies de Lille, 59652 Villeneuve d’Ascq Cedex (France); Dong, Xianlin, E-mail: xldong@mail.sic.ac.cn [Key Laboratory of Inorganic Function Materials and Devices, Shanghai Institute of Ceramics, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 1295 Dingxi Rd., Shanghai 200050 (China)

2016-06-25

Yttrium Iron Garnet (YIG) films were prepared on Si substrates by Chemical Solution Deposition (CSD) technique using acetic acid and deionized water as solvents. Well-crystallized and crack-free YIG films were obtained when annealed at 750 °C and 850 °C respectively, showing a low surface roughness of several nanometers. When annealed at 750 °C for 30 min, the saturated magnetization (Ms) and coercive field (Hc) of YIG films were 0.121 emu/mm{sup 3} (4πMs = 1.52 kGs) and 7 Oe respectively, which were similar to that prepared by PLD technique. The peak-to-peak linewidth of ferromagnetic resonance (FMR) was 220 Oe at 9.10 GHz. The results demonstrated that CSD was an excellent technique to prepare high quality yttrium iron garnet (YIG) films on silicon, which could provide a lower-cost way for large-scale production on Si-based integrated devices. - Highlights: • The preparation of YIG films by Chemical Solution Deposition are demonstrated. • Well-crystallized and crack-free YIG films can be obtained on Si substrate by CSD. • YIG films can be crystallized in 750 °C with good magnetic performances. • It's beneficial to large-scale production of YIG films on Si integrated devices.

Polymeric precursors method for obtaining pigments based on Inorganic oxides of chromium and iron deposited on TiO2

International Nuclear Information System (INIS)

Silva, Everlania M. da; Galvao, Sheila B.; Paskocimas, C.A.

2011-01-01

The case study was the use of chromium oxides and iron, as a precursor in the synthesis of inorganic pigments. The synthesis was based on the dissolution of citric acid as a complexing agent, addition of metal oxides, such as ion chromophores; polymerization with ethylene glycol and doping with titanium oxide. Going through pre-calcination, breakdown, calcination at different temperatures (700, 900 and 1100 deg C resulting in pigments: green for pigment and chromium deposited on TiO2, orange for iron on TiO2. The thermal analysis (TG and DTA), evaluated their thermal decompositions, the XRD revealed the formation of crystalline phases such as iron titanate and chrome titanate; SEM showed the formation of hexagonal particles for both oxides. Under the different analysis, one can see the potential stability of pigments and powders, can be proposed its use as pigments in polymers. (author)

Adsorptive Iron Removal from Groundwater

OpenAIRE

Sharma, S.K.

2001-01-01

Iron is commonly present in groundwater worldwide. The presence of iron in the water supply is not harmful to human health, however it is undesirable. Bad taste, discoloration, staining, deposition in the distribution system leading to aftergrowth, and incidences of high turbidity are some of the aesthetic and operational problems associated with iron in water supplies. Iron removal from groundwater is, therefore, a major concern for water supply companies using groundwater sources....

Synthesizing the Nanocrytalline Cobalt-Iron Coating Through The Electrodeposition Process With Different Time Deposition

Science.gov (United States)

Rozlin Nik Masdek, Nik; Sorfian Hafiz Mansor, Mohd; Salleh, Zuraidah; Hyie, Koay Mei

2018-03-01

In the engineering world, electrodeposition or electroplating has become the most popular method of surface coating in improving corrosion behavior and mechanical properties of material. Therefore in this study, CoFe nanoparticle protective coating has been synthesized on the mild steel washer using electrodeposition method. The electrodeposition was conducted in the acidic environment with the pH value range from 1 to 2 with the controlled temperature of 50°C. The influence of deposition time (30, 60, 90 minutes) towards characteristic and properties such as particle size, surface morphology, corrosion behavior, and microhardness were studied in this investigation. Several results can be obtained by doing this experiment and testing. First, the surface morphology of Cobalt Iron (CoFe) on the electrodeposited mild steel washer are obtained. In addition, the microhardness of the mild steel washer due to the different deposition time are determined. Next, the observation on the difference in the grain size of CoFe that has been electrodeposited on the mild steel plate is made. Last but not least, the corrosion behavior was investigated. CoFe nanoparticles deposited for 30 minutes produced the smallest particle size and the highest microhardness of 86.17 and 236.84 HV respectively. The CoFe nanoparticles also exhibit the slowest corrosion rate at 30 minutes as compared to others. The crystalline size also increases when the time deposition is increased. The sample with 30 minute depositon time indicate the smallest crystalline size which is 15nm. The decrement of deposition time plays an important role in synthesizing CoFe nanoparticles with good corrosion resistance and microhardness. CoFe nanoparticles obtained at 30 minutes shows high corrosion resistance compared to others. In a nutshell, it was observed that the decrement of deposition time improved mechanical and corrosion properties of CoFe nanoparticles.

Preferential soft-tissue preservation in the Hot Creek carbonate spring deposit, British Columbia, Canada

Science.gov (United States)

Rainey, Dustin K.; Jones, Brian

2010-05-01

The relict Holocene Hot Creek carbonate spring deposit in southeast British Columbia is characterized by excellent preservation of soft-tissue organisms (e.g. cyanobacteria), but poor preservation of organisms with hard-tissue (e.g. wood, diatoms). The deposit is formed mainly of calcified cyanobacteria, with fewer mineralized macrophytes (plants), bryophytes (mosses), wood, and diatoms. Cyanobacteria grew as solitary filaments ( Lyngbya) and as radiating hemispherical colonies ( Rivularia). Both were preserved by encrustation and encapsulation while alive, and as casts after filament death and decay. Sheath impregnation was rare to absent. Filament encrustation, whereby calcite crystals nucleated on, and grew away from the sheath exterior, produced moulds that replicated external filament morphology, but hastened filament decay. Filament encapsulation, whereby calcite nucleated in the vicinity of, and grew towards the encapsulated filament, promoted sheath preservation even after trichome decay. Subsequent calcite precipitation inside the hollow sheath generated sheath casts. The inability of mineralizing spring water to penetrate durable cell walls meant that bryophytes, macrophytes, and most wood was preserved by encrustation. Some wood resisted complete decay for several thousand years, and its lignified cell walls allowed rare permineralizations. Diatoms were not preserved in the relict deposit because the frustules were dissolved by the basic spring water. Amorphous calcium carbonate produced by photosynthetic CO 2 removal may have acted as nucleation sites for physicochemically precipitated calcite. Thus, metabolic activities of floral organisms probably initiated biotic mineralization, but continuous inorganic calcite precipitation on and in flora ensured that soft tissues were preserved.

Iron isotope fractionation during hydrothermal ore deposition and alteration

Science.gov (United States)

Markl, Gregor; von Blanckenburg, Friedhelm; Wagner, Thomas

2006-06-01

Iron isotopes fractionate during hydrothermal processes. Therefore, the Fe isotope composition of ore-forming minerals characterizes either iron sources or fluid histories. The former potentially serves to distinguish between sedimentary, magmatic or metamorphic iron sources, and the latter allows the reconstruction of precipitation and redox processes. These processes take place during ore formation or alteration. The aim of this contribution is to investigate the suitability of this new isotope method as a probe of ore-related processes. For this purpose 51 samples of iron ores and iron mineral separates from the Schwarzwald region, southwest Germany, were analyzed for their iron isotope composition using multicollector ICP-MS. Further, the ore-forming and ore-altering processes were quantitatively modeled using reaction path calculations. The Schwarzwald mining district hosts mineralizations that formed discontinuously over almost 300 Ma of hydrothermal activity. Primary hematite, siderite and sulfides formed from mixing of meteoric fluids with deeper crustal brines. Later, these minerals were partly dissolved and oxidized, and secondary hematite, goethite and iron arsenates were precipitated. Two types of alteration products formed: (1) primary and high-temperature secondary Fe minerals formed between 120 and 300 °C, and (2) low-temperature secondary Fe minerals formed under supergene conditions (illustrates the potential of the new technique in deciphering ore formation and alteration processes. Isotope ratios are strongly dependent on and highly characteristic of fluid and precipitation histories. Therefore, they are less suitable to provide information on Fe sources. However, it will be possible to unravel the physico-chemical processes leading to the formation, dissolution and redeposition of ores in great detail.

Contribution to the study of the electrodeposition of iron-nickel alloys

International Nuclear Information System (INIS)

Valignat, J.

1968-01-01

Using a coulometric technique based upon the anodic intentiostatic dissolution, we studied the potentiostatic, deposition of nickel, iron and nickel iron alloys. We have shown that the minimum of the curve I = f (t) (deposition current versus time) is probably due to the transitory blocking of the surface by hydrogen and that the syn-crystallisation of nickel and iron is responsible for the anomalous co-deposition of these two elements. (author) [fr

Depositing Nickel-based Hardfacing to Join Carbon Steel and Cast Iron

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Tomás Fernández-Columbié

2016-10-01

Full Text Available The objective of this investigation is to determine the micro-structural behavior of a joint between cast iron and carbon steel by depositing a nickel-based substrate in the carbon steel. The filler was added through Shielded Metal Arc Welding using Castec 3099 (UTP 8 electrodes while the base materials were joined through Gas Tungsten Arc Welding with ER 70S – A1 bare electrodes. The Schaeffler diagram was used to analyze the chemical composition of the resulting weld beads. The results of the analysis performed on the welded area and the heat influence zone indicated the formation of acicular structures near the welded line when Castec 3099 electrodes are used and the formation of skeletal ferrite on the heat influence zone during the application of this welding process. An austenitic mixture is formed when ER 70S – A1 electrodes are used.

Biodiversity hot spot on a hot spot: novel extremophile diversity in Hawaiian fumaroles.

Science.gov (United States)

Wall, Kate; Cornell, Jennifer; Bizzoco, Richard W; Kelley, Scott T

2015-01-06

Fumaroles (steam vents) are the most common, yet least understood, microbial habitat in terrestrial geothermal settings. Long believed too extreme for life, recent advances in sample collection and DNA extraction methods have found that fumarole deposits and subsurface waters harbor a considerable diversity of viable microbes. In this study, we applied culture-independent molecular methods to explore fumarole deposit microbial assemblages in 15 different fumaroles in four geographic locations on the Big Island of Hawai'i. Just over half of the vents yielded sufficient high-quality DNA for the construction of 16S ribosomal RNA gene sequence clone libraries. The bacterial clone libraries contained sequences belonging to 11 recognized bacterial divisions and seven other division-level phylogenetic groups. Archaeal sequences were less numerous, but similarly diverse. The taxonomic composition among fumarole deposits was highly heterogeneous. Phylogenetic analysis found cloned fumarole sequences were related to microbes identified from a broad array of globally distributed ecotypes, including hot springs, terrestrial soils, and industrial waste sites. Our results suggest that fumarole deposits function as an "extremophile collector" and may be a hot spot of novel extremophile biodiversity. © 2015 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

Atmospheric processing of iron carried by mineral dust

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S. Nickovic

2013-09-01

Full Text Available Nutrification of the open ocean originates mainly from deposited aerosol in which the bio-avaliable iron is likely to be an important factor. The relatively insoluble iron in dust from arid soils becomes more soluble after atmospheric processing and, through its deposition in the ocean, could contribute to marine primary production. To numerically simulate the atmospheric route of iron from desert sources to sinks in the ocean, we developed a regional atmospheric dust-iron model that included parameterization of the transformation of iron to a soluble form caused by dust mineralogy, cloud processes and solar radiation. When compared with field data on the aerosol iron, which were collected during several Atlantic cruises, the results from the higher-resolution simulation experiments showed that the model was capable of reproducing the major observed patterns.

Study on the deposition patterns of aerosol inhalation scintigraphy, 2

International Nuclear Information System (INIS)

Watanabe, Hiroyuki

1989-01-01

The superimposed images obtained by the SPECT of aeresol inhalation scintigraphy and chest CT were applied in 7 cases of diffuse panbronchiolitis. Aerosol deposition patterns were examined, and hot spots were compared with bronchial morphological abnormalities. The results were as follows: 1. Nevertheless, aerosol deposition patterns were characterized by defects of the depositions in the outer zone and hot spots in the inner zone, hot spots distributed from the inner zone to the outer zone. 2. Hot spots and bronchial morphological abnormalities were markedly matched in the inner zone; however, they were mismatched in the outer zone. I concluded that the mechanisms of hot spot formation in the inner zone were different from those in the outer zone. (author)

Diagenetic Changes in Common Hot Spring Microfacies

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Hinman, N. W.; Kendall, T. A.; MacKenzie, L. A.; Cady, S. D.

2016-05-01

The friable nature of silica hot spring deposits makes them susceptible to mechanical weathering. Rapid diagenesis must take place for these rocks to persist in the geologic record. The properties of two microfacies at two deposits were compared.

A high-temperature hydrothermal deposit on the East Pacific Rise near 70N

International Nuclear Information System (INIS)

Boulegue, J.; Stouff, P.; Perseil, E.A.; Bernat, M.; Dupre, B.; Francheteau, J.

1984-01-01

A SEABEAM survey of the East Pacific Rise (EPR) led to the selection of several sites having structural characteristics favorable for hydrothermal activity. Dredging of such an area located at 7 0 N on the EPR resulted in the recovery of sulfides, oxides and fresh basalt. Chemical analyses and isotopic compositions showed that the recovered pyrites were probably precipitated directly from hot vent hydrothermal waters. Chemical analyses and isotopic composition of manganese-iron oxides indicated that they too were of hydrothermal origin. 210 Pb/Pb measurements yielded ages of 90 +- 10 years for the deposits. This site may still be undergoing hydrothermal activity. (orig.)

Iron and Prochlorococcus

Science.gov (United States)

2009-06-01

including: acid -cleaned filters, filters rinsed with un-amended trace-metal clean seawater, and filters rinsed with the oxalate solution followed by...greatly influenced by the sources of iron to the marine environment, which include riverine input, hydrothermal upwelling, and atmospheric...deposition (Jickells et al, 2005). While the amount of iron introduced to the oceans from riverine and hydrothermal sources is high, precipitation occurs

Adsorptive iron removal from groundwater

NARCIS (Netherlands)

Sharma, S.K.

2001-01-01

Iron is commonly present in groundwater worldwide. The presence of iron in the water supply is not harmful to human health, however it is undesirable. Bad taste, discoloration, staining, deposition in the distribution system leading to aftergrowth, and incidences of high turbidity are some

Precipitation of iron species on the cold side of PWR steam generator and its possible correlation to dose rate elevation

International Nuclear Information System (INIS)

Bengtsson, Bernt; Chen, Jiaxin; Andersson, Petter

2014-01-01

For the last 10 years of service of Ringhals PWR unit 4, operating with Alloy-600MA steam generator tubing materials and a coolant pH of 7.2 (a)300°C, the cold water channel heads experienced continuous dose rate elevation. In the hot parts, however, it remained stable. Similar observations were made in Ringhals unit 2 and 3 after SGR to Alloy 690 and sometimes in other PWRs operated at similarly 'low' pH-regime. Following the introduction of elevated pH regime at Ringhals PWRs the cold side dose rates dropped to the similar levels as on the hot side. The phenomena are analysed in this paper from three different aspects: (1) the general plant observations in dose rate development under different coolant pH regimes; (2) the concentrations of dissolved and soluble iron species at the low and high coolant pH values and (3) the microstructures of the oxide films formed on the cold and hot sides of a steam generator tube pulled from a retired steam generator. Based on the analyses a hypothesis is elaborated that the formation of a thin but highly radioactive layer of iron-rich oxide deposit on the cold side may be responsible for the dose rate elevation and that its formation may be harder at the elevated pH regime. (author)

Bio-mimicked atomic-layer-deposited iron oxide-based memristor with synaptic potentiation and depression functions

Science.gov (United States)

Wan, Xiang; Gao, Fei; Lian, Xiaojuan; Ji, Xincun; Hu, Ertao; He, Lin; Tong, Yi; Guo, Yufeng

2018-06-01

In this study, an iron oxide (FeO x )-based memristor was investigated for the realization of artificial synapses. An FeO x resistive switching layer was prepared by self-limiting atomic layer deposition (ALD). The movement of oxygen vacancies enabled the device to have history-dependent synaptic functions, which was further demonstrated by device modeling and simulation. Analog synaptic potentiation/depression in conductance was emulated by applying consecutive voltage pulses in the simulation. Our results suggest that the ALD FeO x -based memristor can be used as the basic building block for neural networks, neuromorphic systems, and brain-inspired computers.

Anthropogenic combustion iron as a complex climate forcer.

Science.gov (United States)

Matsui, Hitoshi; Mahowald, Natalie M; Moteki, Nobuhiro; Hamilton, Douglas S; Ohata, Sho; Yoshida, Atsushi; Koike, Makoto; Scanza, Rachel A; Flanner, Mark G

2018-04-23

Atmospheric iron affects the global carbon cycle by modulating ocean biogeochemistry through the deposition of soluble iron to the ocean. Iron emitted by anthropogenic (fossil fuel) combustion is a source of soluble iron that is currently considered less important than other soluble iron sources, such as mineral dust and biomass burning. Here we show that the atmospheric burden of anthropogenic combustion iron is 8 times greater than previous estimates by incorporating recent measurements of anthropogenic magnetite into a global aerosol model. This new estimation increases the total deposition flux of soluble iron to southern oceans (30-90 °S) by 52%, with a larger contribution of anthropogenic combustion iron than dust and biomass burning sources. The direct radiative forcing of anthropogenic magnetite is estimated to be 0.021 W m -2 globally and 0.22 W m -2 over East Asia. Our results demonstrate that anthropogenic combustion iron is a larger and more complex climate forcer than previously thought, and therefore plays a key role in the Earth system.

A composite mouse model of aplastic anemia complicated with iron overload.

Science.gov (United States)

Wu, Dijiong; Wen, Xiaowen; Liu, Wenbin; Xu, Linlong; Ye, Baodong; Zhou, Yuhong

2018-02-01

Iron overload is commonly encountered during the course of aplastic anemia (AA), but no composite animal model has been developed yet, which hinders drug research. In the present study, the optimal dosage and duration of intraperitoneal iron dextran injection for the development of an iron overload model in mice were explored. A composite model of AA was successfully established on the principle of immune-mediated bone marrow failure. Liver volume, peripheral hemogram, bone marrow pathology, serum iron, serum ferritin, pathological iron deposition in multiple organs (liver, bone marrow, spleen), liver hepcidin, and bone morphogenetic protein 6 (BMP6), SMAD family member 4 (SMAD4) and transferrin receptor 2 (TfR2) mRNA expression levels were compared among the normal control, AA, iron overload and composite model groups to validate the composite model, and explore the pathogenesis and features of iron overload in this model. The results indicated marked increases in iron deposits, with significantly increased liver/body weight ratios as well as serum iron and ferritin in the iron overload and composite model groups as compared with the normal control and AA groups (Poverload and AA was successfully established, and AA was indicated to possibly have a critical role in abnormal iron metabolism, which promoted the development of iron deposits.

Dissolution of manganese and cobalt and their deposition on Type 304 stainless steel in liquid sodium

International Nuclear Information System (INIS)

Yokota, Norikatsu; Shimoyashiki, Shigehiro

1989-01-01

Dissolution of manganese and cobalt and their deposition on Type 304 stainless steel in liquid sodium at 833 K for 3.6 x 10 3 ks were examined using a liquid sodium pot. Manganese was easily dissolved in sodium from the iron-manganese alloy specimen and deposited on the steel to form two kind of deposition particles, α-phase (body-centered cubic) composed of iron and γ-phase (face-centered cubic) composed of iron and manganese, respectively. Cobalt which was less easily dissolved than manganese also deposited on the Type 304 stainless steel, giving an iron-cobalt alloy. These three deposition particles corresponded to the precipitation lines of iron-manganese and iron-cobalt phase diagrams at 833 K, respectively. Therefore, the deposition process of manganese or cobalt in sodium was explained as a precipitation process of iron-manganese or iron-cobalt in the solid region of the binary phase diagram. A sodium chromite (NaCrO 2 ) layer was formed on the steel surface. (author)

Uranium exploration target selection for proterozoic iron oxide/breccia complex type deposits in India

International Nuclear Information System (INIS)

Dwivedy, K.K.; Sinha, K.K.

1997-01-01

Multimetal iron oxide/breccia complex (IOBC) type deposits exemplified by Olympic Dam in Australia, fall under low grade, large tonnage deposits. A multidisciplinary integrated exploration programme consisting of airborne surveys, ground geological surveys, geophysical and geochemical investigations and exploratory drilling, supported adequately by the state of the art analytical facilities, data processing using various software and digital image processing has shown moderate success in the identification of target areas for this type of deposits in the Proterozoic terrains of India. Intracratonic, anorogenic, continental rift to continental margin environment have been identified in a very wide spectrum of rock associations. The genesis and evolution of such associations during the Middle Proterozoic period have been reviewed and applied for target selection in the (i) Son-Narmada rift valley zone; (ii) areas covered by Dongargarh Supergroup of rocks in Madhya Pradesh; (iii) areas exposing ferruginous breccia in the western part of the Singhbhum Shear Zone (SSZ) around Lotapahar; (iv) Siang Group of rocks in Arunachal Pradesh; (v) Crystalline rocks of Garo Hills around Anek; and (vi) Chhotanagpur Gneissic complex in the Bahia-Ulatutoli tract of Ranchi Plateau. Of theses six areas, the Son-Narmada rift area appears to be the most promising area for IOBC type deposits. Considering occurrences of the uranium anomalies near Meraraich, Kundabhati, Naktu and Kudar and positive favourability criteria observed in a wide variety of rocks spatially related to the rifts and shears, certain sectors in Son-Narmada rift zone have been identified as promising for intense subsurface exploration. 20 refs, 4 figs, 1 tab

Chemical Compositions of Fluid Inclusions in the Jalal –Abad iron oxide deposit, North West of Zarand, Using LA-ICP-MS Microanalysis

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Behrouz Karimi Shahraki

2017-07-01

Full Text Available Introduction The Poshtebadam Bafq Zarand district in central Iran is a world class iron oxide province. This region contains over two billion tons of iron ore reserves within more than 34 major magnetic anomalies and deposits in an area of 7,500 km2 (Stosch et al., 2011. The Jalal-Abad iron ore deposit (200Mt at 45% Fe, 1.18% S and 0.08% P is located 38 km northwest of Zarand, 16 km southeast of the Rizu town in the Kerman province, Iran. Iron ore deposits are hosted by the Early Cambrian Rizu Series, composed mainly of sedimentary, volcanic and volcaniclastic rocks which are dominated by dolomite, sandstone, shale, siltstone, tuff, ignimbrite and rhyodacite. The origin of the iron oxide deposits is controversial and various genetic models have been suggested. Some researchers believe in magmatic origins or Kiruna type, while others suggest metasomatic replacement from pre-existing rocks (Stosch et al., 2011. LA-ICP-MS has been used to characterize the multi element chemistry of the diverse fluid inclusions found in the Jalal–Abad iron oxide deposit. The aim of this investigation was to understand the genesis of the ore body and identify possible hydrothermal fluid sources in the Jalal-Abad district. Sampling and method of study About 100 samples from different types of ore were collected from surface outcrops and a drill core whose association with mineralization are well established. Thin sections, polished thin sections and polished sections were prepared. SEM studies (FEI 5900LV and LA-ICP-MS analyses of fluid inclusions were carried out in the School of Earth and Environment, the University of Leeds, UK. Fluid inclusions were studied using a Linkam THM-600 heating-freezing stage mounted on Zeiss petrography microscope at the Iranian Mineral Processing Research Center. Result and discussion Jalal Abad deposit is hosted by the early Cambrian volcano-sedimentary rocks of the Rizu series. Stratabound mineralization occurs in a variety of

Carbonate petrography, kerogen distribution, and carbon and oxygen isotope variations in an early Proterozoic transition from limestone to iron-formation deposition, Transvaal Supergroup, South Africa

Science.gov (United States)

Beukes, N. J.; Klein, C.; Kaufman, A. J.; Hayes, J. M.

1990-01-01

The transition zone comprises Campbellrand microbialaminated (replacing "cryptalgalaminate") limestone and shale, with minor dolomite, conformably overlain by the Kuruman Iron Formation of which the basal part is characterized by siderite-rich microbanded iron-formation with minor magnetite and some hematite-containing units. The iron-formation contains subordinate intraclastic and microbialaminated siderite mesobands and was deposited in deeper water than the limestones. The sequence is virtually unaltered with diagenetic mineral assemblages reflecting a temperature interval of about 110 degrees to 170 degrees C and pressures of 2 kbars. Carbonate minerals in the different rock types are represented by primary micritic precipitates (now recrystallized to microsparite), early precompactional sparry cements and concretions, deep burial limpid euhedral sparites, and spar cements precipitated from metamorphic fluids in close contact with diabase sills. Paragenetic pathways of the carbonate minerals are broadly similar in all lithofacies with kerogen intimately associated with them. Kerogen occurs as pigmentation in carbonate crystals, as reworked organic detritus in clastic-textured carbonate units, and as segregations of kerogen pigment around late diagenetic carbonate crystals. Locally kerogen may also be replaced by carbonate spar. Carbon isotope compositions of the carbonate minerals and kerogen are dependent on their mode of occurrence and on the composition of the dominant carbonate species in a specific lithofacies. Integration of sedimentary, petrographic, geochemical, and isotopic results makes it possible to distinguish between depositional, early diagenetic, deep burial, and metamorphic effects on the isotopic compositions of the carbonate minerals and the kerogen in the sequence. Major conclusions are that deep burial thermal decarboxylation led to 13C depletion in euhedral ferroan sparites and 13C enrichment in kerogen (organic carbon). Metamorphic

Catalyst Design Using Nanoporous Iron for the Chemical Vapor Deposition Synthesis of Single-Walled Carbon Nanotubes

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Tarek M. Abdel-Fattah

2013-01-01

Full Text Available Single-walled carbon nanotubes (SWNTs have been synthesized via a novel chemical vapor deposition (CVD approach utilizing nanoporous, iron-supported catalysts. Stable aqueous dispersions of the CVD-grown nanotubes using an anionic surfactant were also obtained. The properties of the as-produced SWNTs were characterized through atomic force microscopy and Raman spectroscopy and compared with purified SWNTs produced via the high-pressure CO (HiPCO method as a reference, and the nanotubes were observed with greater lengths than those of similarly processed HiPCO SWNTs.

Erosion-corrosion entrainment of iron-containing compounds as a source of deposits in steam generators used at nuclear power plants equipped with VVER reactors

Science.gov (United States)

Tomarov, G. V.; Shipkov, A. A.

2011-03-01

The main stages and processes through which deposits are generated, migrate, and precipitate in the metal-secondary coolant system of power units at nuclear power plants are analyzed and determined. It is shown that substances produced by the mechanism of general erosion-corrosion are the main source of the ionic-colloid form of iron, which is the main component of deposits in a steam generator. Ways for controlling the formation of deposits in a nuclear power plant's steam generator are proposed together with methods for estimating their efficiency.

Printing and Curing of Conductive Ink Track on Fabric using Syringe Deposition System with DLP Projector and Hot Plate

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Khirotdin Rd. Khairilhijra

2017-01-01

Full Text Available Printing is a technique to transfer ink onto substrates to create pattern and syringe deposition system has shown some great potential in printing due to its ability to produce filamentary bead tracks which is important concerning conductivity and easily adopted on conformal surfaces which could not be realized by conventional technique. Fabrics with integrated electrical features able to create intelligent articles and may potentially open up new perspective areas of application in textile printing. However, the applicability of this technique on fabrics remains unknown which the ink used has to meet certain requirements including high electrical conductivity, resistance to oxidation, dry out without clogging, good adhesion with suitable viscosity and surface tension. Thus, there is a need to do this study which is to determine the feasibility of syringe deposition system to print a conductive ink tracks using silver epoxy-based conductive ink on fabric substrate via lycra material. This study is also aim to investigate the feasibility of using DLP projector with hot plate as another source of heat to be used in curing the ink tracks on fabric. The effect of printing and curing parameters to the characteristics and conductivity of the ink track is investigated. Several mechanical and electrical tests were also administered to determine the cure, hardness, adhesion and resistance level of the ink tracks. The results obtained were as expected which higher printing speed and lower deposition height used, a narrower and thinner ink tracks were produced. Sample with 4 mm/s of printing speed and deposition height of 1 mm resulted in dimension closer to the targeted dimension. The longer curing time and higher temperature used, a lower resistance is produced. The lowest resistance achieved is 0.9 Ω cured at 150°C for 60 minutes. The conductivity of the ink track was affected by curing process and cross-sectional area of the ink track. It is proven

Quantitative T2* magnetic resonance imaging for evaluation of iron deposition in the brain of β-thalassemia patients.

Science.gov (United States)

Akhlaghpoor, S; Ghahari, A; Morteza, A; Khalilzadeh, O; Shakourirad, A; Alinaghizadeh, M R

2012-09-01

Iron overload is a common clinical problem in patients with β-thalassemia major. The purpose of this study was to assess the presence of excess iron in certain areas of the brain (thalamus, midbrain, adenohypophysis and basal ganglia) in patients with β-thalassemia major and evaluate the association with serum ferritin and liver iron content. A cross-sectional study on 53 patients with β-thalassemia major and 40 healthy controls was carried out. All patients and healthy controls underwent magnetic resonance imaging (MRI) examinations of the brain and liver. Multiecho fast gradient echo sequence was used and T2* values were calculated based on the Brompton protocol. Correlations between T2* values in the brain with T2* values in the liver as well as serum ferritin levels were investigated. There were no significant differences between patients and healthy controls with respect to age and sex. Patients had significantly lower T2* values in basal ganglia (striatum), thalamus and adenohypophysis compared to controls while there were no differences in the midbrain (red nucleus). There were no significant correlations between liver T2* values or serum ferritin with T2* values of basal ganglia (striatum), thalamus and adenohypophysis in patients or healthy controls. There were no significant correlations between T2* values of adenohypophysis and thalamus or basal ganglia (striatum) while these variables were significantly correlated in healthy controls. Serum ferritin and liver iron content may not be good indicators of brain iron deposition in patients with β thalassemia major. Nevertheless, the quantitative T2* MRI technique is useful for evaluation of brain iron overload in β thalassemia major patients.

Iron and chlorine as guides to stratiform Cu-Co-Au deposits, Idaho Cobalt Belt, USA

Science.gov (United States)

Nash, J.T.; Connor, J.J.

1993-01-01

The Cu-Co-Au deposits of the Idaho Cobalt Belt are in lithostratigraphic zones of the Middle Proterozoic Yellowjacket Formation characterized by distinctive chemical and mineralogical compositions including high concentrations of Fe (15- > 30 wt. percent Fe2O3), Cl (0.1-1.10 wt. percent), and magnetite or biotite (> 50 vol. percent). The Cu-Co-Au deposits of the Blackbird mine are stratabound in Fe-silicate facies rocks that are rich in biotite, Fe, and Cl, but stratigraphically equivalent rocks farther than 10 km from ore deposits have similar compositions. A lower lithostratigraphic zone containing magnetite and small Cu-Co-Au deposits extends for more than 40 km. The Fe-rich strata are probably exhalative units related to mafic volcanism and submarine hot springs, but the origin of the high Cl concentrations is less clear. Former chlorine-rich pore fluids are suggested by the presence of supersaline fluid inclusions, by Cl-rich biotite and scapolite (as much as 1.87 percent Cl in Fe-rich biotite), and by high Cl concentrations in rock samples. Chlorine is enriched in specific strata and in zones characterized by soft-sediment deformation, thus probably was introduced during sedimentation or diagenesis. Unlike some metasedimentary rocks containing scapolite and high Cl, the Yellowjacket Formation lacks evidence for evaporitic strata that could have been a source of Cl. More likely, the Cl reflects a submarine brine that carried Fe, K, and base metals. Strata containing anomalous Fe-K-Cl are considered to be a guide to sub-basins favorable for the occurrence of stratiform base-metal deposits. ?? 1993 Springer-Verlag.

Hot working behavior of selective laser melted and laser metal deposited Inconel 718

Science.gov (United States)

Bambach, Markus; Sizova, Irina

2018-05-01

The production of Nickel-based high-temperature components is of great importance for the transport and energy sector. Forging of high-temperature alloys often requires expensive dies, multiple forming steps and leads to forged parts with tolerances that require machining to create the final shape and a large amount of scrap. Additive manufacturing offers the possibility to print the desired shapes directly as net-shape components, requiring only little additional effort in machining. Especially for high-temperature alloys carrying a large amount of energy per unit mass, additive manufacturing could be more energy-efficient than forging if the energy contained in the machining scrap exceeds the energy needed for powder production and laser processing. However, the microstructure and performance of 3d-printed parts will not reach the level of forged material unless further expensive processes such as hot-isostatic pressing are used. Using the design freedom and possibilities to locally engineer material, additive manufacturing could be combined with forging operations to novel process chains, offering the possibility to reduce the number of forging steps and to create near-net shape forgings with desired local properties. Some innovative process chains combining additive manufacturing and forging have been patented recently, but almost no scientific knowledge on the workability of 3D printed preforms exists. The present study investigates the flow stress and microstructure evolution during hot working of pre-forms produced by laser powder deposition and selective laser melting (Figure 1) and puts forward a model for the flow stress.

Physiological and behavioural responses of young horses to hot iron branding and microchip implantation.

Science.gov (United States)

Erber, R; Wulf, M; Becker-Birck, M; Kaps, S; Aurich, J E; Möstl, E; Aurich, C

2012-02-01

Branding is the traditional and well-established method used to mark horses, but recently microchip transponders for implantation have become available. In this study, behaviour, physiological stress variables and skin temperature in foals were determined in response to hot-iron branding (n=7) and microchip implantation (n=7). Salivary cortisol concentrations increased in response to branding (1.8 ± 0.2 ng/mL) and microchip implantation (1.4 ± 0.1ng/mL), but cortisol release over time did not differ. In response to both manipulations there was a transient increase in heart rate (PBranding and microchip implantation induced a comparable aversive behaviour (branding, score 3.86 ± 0.85; microchip, score 4.00 ± 0.82). Both techniques thus caused similar physiological and behavioural changes indicative of stress. Acutely, implantation of a microchip was as stressful as branding in foals. Branding caused a necrotising skin burn lasting at least 7 days. Moreover branding, but not microchip implantation (P<0.001), was accompanied by a generalized increase in skin temperature which was comparable to low degree post-burn hypermetabolism in humans. Copyright © 2011 Elsevier Ltd. All rights reserved.

Assessing the Roles of Iron, Macronutrients and Wet deposition in Controlling Phytoplankton Growth in Seasonally Oligotrophic Waters of the Mid-Atlantic Bight

Science.gov (United States)

Sedwick, P.; Mulholland, M. R.; Najjar, R.; Bernhardt, P. W.; Price, L. M.; Sohst, B. M.; Sookhdeo, C.; Widner, B.

2016-02-01

The role of iron supply in regulating phytoplankton production in high-nutrient, low-chlorophyll ocean regions has been well established. Less clear, however, is the importance of iron for phytoplankton processes in other oceanic settings, such as coastal and oligotrophic waters, where differential changes in the supply and removal of dissolved iron (dFe) can result in limitation or co-limitation of growth due to iron deficiency. One such region of interest is the Mid-Atlantic Bight (MAB), where previous field experiments have provided some evidence of co-limitation of algal growth by nitrogen and iron. In summer 2014 we conducted field sampling and shipboard experiments to assess the role of iron and macronutrient availability in controlling primary production in seasonally oligotrophic waters over the MAB continental slope, with a focus on the the impacts of wet deposition. Our results indicate that nitrogen was the proximate limiting nutrient, with a secondary limitation imposed by availability of phosphorus; we found no evidence for a deficiency in dFe, which was present at concentrations in the range 0.3-0.9 nM. Phytoplankton growth was clearly stimulated by the addition of natural rainwater, suggesting that summer rain events stimulate primary production in the MAB by contributing new nitrogen (primarily as ammonium) and phosphorus, whilst maintaining iron-replete conditions.

Simulating Precambrian banded iron formation diagenesis

DEFF Research Database (Denmark)

Posth, Nicole R.; K??hler, Inga; D. Swanner, Elizabeth

2013-01-01

Post-depositional diagenetic alteration makes the accurate interpretation of key precipitation processes in ancient sediments, such as Precambrian banded iron formations (BIFs), difficult. While microorganisms are proposed as key contributors to BIF deposition, the diagenetic transformation...

Study of the sulfur mechanism on the formation of coke deposition on iron surfaces; Etude des mecanismes d'action du soufre sur le cokage catalytique du fer

Energy Technology Data Exchange (ETDEWEB)

Bonnet, F.

2001-12-01

The formation of coke deposition which occurs in a range of temperature 500 deg C-650 deg C is a major problem in many chemical and petrochemical processes where hydrocarbons or other strongly carburizing atmospheres are involved. To reduce the rate of coke deposition, sulfur can be added in the gas phase. The topic of this work is to study the sulfur mechanism on the formation of coke deposition on iron surfaces. Firstly, we study the mechanism of graphitic filament formation on reduced and oxidised iron surfaces. A new mechanism of catalytic particle formation is proposed when the surface is initially oxidised. This mechanism is based on thermodynamic, kinetic and structural considerations. The results show that oxide/carbide transitions are involved in the transformation of the oxide layer in catalytic particles. Although the different iron oxides are precursors for the formation of catalytic particles, wustite (FeO) has a better reactivity than magnetite (Fe{sub 3}O{sub 4}) and hematite (Fe{sub 2}O{sub 3}). Sulfur acts on different steps of the coke formation, preventing phase transformations (carburation, graphitization) which occur during the formation of catalytic particles. Sulfur activity required to prevent these transformations changes with the temperature, the chemical state of iron (reduced or oxidised) and the carbon activity in the gas phase. Sulfur/ethylene co-adsorption studies were performed on mono-crystal of iron (110). The results show that sulfur can prevent adsorption and decomposition of this hydrocarbon on metallic surface (Fe) and on magnetite (Fe{sub 3}O{sub 4}). Then, sulfur prevents the reaction leading to the carburation and graphitization of the surface. (author)

Iron oxide copper-gold deposits in the Islamic Republic of Mauritania (phase V, deliverable 79): Chapter M in Second projet de renforcement institutionnel du secteur minier de la République Islamique de Mauritanie (PRISM-II)

Science.gov (United States)

Fernette, Gregory

2015-01-01

Mauritania hosts one significant copper-gold deposit, Guelb Moghrein and several occurrences, which have been categorized as iron oxide copper-gold (IOCG) deposits but which are atypical in some important respects. Nonetheless, Guelb Moghrein is an economically significant mineral deposit and an attractive exploration target. The deposit is of Archean age and is hosted by a distinctive metacarbonate rock which is part of a greenstone-banded iron formation (BIF) package within a thrust stack in the northern part of the Mauritanide Belt. The surrounding area hosts a number of similar copper-gold occurrences. Based on the characteristics of the Guelb Moghrein deposit and its geologic environment, five tracts which are considered permissive for IOCG type mineralization similar to Guelb Moghrein have been delineated.

Effects of hot-iron branding on heart rate, breathing rate and behaviour of anaesthetised Steller sea lions.

Science.gov (United States)

Walker, K A; Mellish, J E; Weary, D M

2011-10-01

This study assessed the heart rate, breathing rate and behavioural responses of 12 juvenile Steller sea lions during hot-iron branding under isoflurane anaesthesia. Physiological and behavioural measures were recorded in four periods: baseline (five minutes), sham branding (one minute), branding (approximately 2.7 minutes) and postbranding (five minutes). No difference in heart rate was noted from baseline to sham branding, but heart rate increased from mean (sem) 78.3 (2.4) bpm in the baseline period to 85.6 (2.5) bpm in the branding period. Heart rate remained elevated in the postbranding period, averaging 84.7 (2.5) bpm. Breathing rate averaged 2.5 (1.0) breaths/minute in the baseline and sham branding periods increased to 8.9 (1.0) breaths/minute during branding, but returned to baseline by the postbranding period. Behaviourally, half of the sea lions exhibited trembling and head and shoulder movements during branding.

Multifragmentation of hot nuclei

International Nuclear Information System (INIS)

Tamain, B.

1990-10-01

It is difficult to deposit a large amount (∼ 1 Gev) of excitation energy into a nucleus. And if one wants to deposit large excitation energy values, the best way consists of shooting a given target nucleus with several nucleons, which can be achieved by using intermediate energy (10-100 MeV/nucleon) heavy ions. Such very excited objects were named hot nuclei. The study of hot nuclei has been undertaken only for 7 years because intermediate energy heavy ion facilities were not available before. The game is then to determine the decay properties of such nuclei, their limits of existence. Their study is connected with general properties of nuclear matter: namely its equation of state. Of special interest, is the onset of a new decay mechanism: multifragmentation, which is the non-sequential disassembly of a hot nucleus into several light nuclei (often called intermediate-mass fragments or IMF) or particles. This paper, shows how this mechanism can reflect fundamental properties of nuclear matter, but also how its experimental signature is difficult to establish. Multifragmentation has also been studied by using very energetic projectiles (protons and heavy ions) in the relativistic or ultra-relativistic region. The multifragmentation question of hot nuclei is far from being solved. One knows that IMF production increases when the excitation energy brought into a system is strongly increased, but very little is known about the mechanisms involved and a clear onset for multifragmentation is not established

The palaeoenvironmental implications of carbonate petrography, kerogen distribution and carbon and oxygen isotope variations in the early Proterozoic transition from Campbellrand limestone to Kuruman iron-formation deposition in Griqualand West

International Nuclear Information System (INIS)

Beukes, N.J.; Klein, C.; Kaufman, A.J.; Hayes, J.M.

1990-01-01

The Griqualand West area of the Transvaal basin in South Africa offers a unique opportunity to study the relationships between the deposition of limestone and iron-formation. The stratigraphic sequence includes the transition from microbialaminated Campbellrand carbonates to the conformably Kuruman iron formation composed mainly of microbanded iron-formation. The relationships between carbonate mineral paragenesis, kerogen abundance, and isotopic compositions of carbon and oxygen for the same drill core samples are reported. The significance of whole rock carbon-isotopic compositions of iron-formations relative to those of limestones and dolomites are explored. 6 refs

Compositional variation of glauconites in Upper Cretaceous-Paleogene sedimentary iron-ore deposits in South-eastern Western Siberia

Science.gov (United States)

Rudmin, Maxim; Banerjee, Santanu; Mazurov, Aleksey

2017-06-01

Glauconite occurs either as unaltered greenish or as altered brownish variety in Upper Cretaceous-Palaeocene sediments in the southeastern corner of Western Siberia. Studied section within the Bakchar iron-ore deposit includes Ipatovo, Slavgorod, Gan'kino and Lyulinvor formations, which are represented by sandstones, siltstones, claystones and oolitic ironstones of coastal-marine facies. The origin of unaltered glauconite is explained by the ;verdissement theory;. Transgressions during Lower Coniacian, Santonian and Campanian favored the formation of unaltered glauconites in dysoxic to anoxic conditions. Subaerial exposure of glauconite resulted in leaching of potassium, oxidation of iron and formation of iron hydroxides in Upper Coniacian, Maastrichtian and Palaeocene. Glauconite ultimately converts to leptochlorite and hydrogoethite by this alteration. Abundant microscopic gold inclusions, besides sulphides, sulphates, oxides and silicates characterize this glauconite. Mineral inclusions include precious, rare metals and non-ferrous metals. The concentration of gold in glauconite may be as high as 42.9 ppb. Abundant inclusions of various compositions in glauconites indicate enrichment of marine sediments in precious and non-precious metals. While major element composition of glauconites is affected by subaerial exposure, the broadly similar micro-inclusions in both altered and unaltered varieties are possibly related to the comparatively immobile nature of REE and trace elements.

Fe-O stable isotope pairs elucidate a high-temperature origin of Chilean iron oxide-apatite deposits

Science.gov (United States)

Bilenker, Laura D.; Simon, Adam C.; Reich, Martin; Lundstrom, Craig C.; Gajos, Norbert; Bindeman, Ilya; Barra, Fernando; Munizaga, Rodrigo

2016-03-01

Iron oxide-apatite (IOA) ore deposits occur globally and can host millions to billions of tons of Fe in addition to economic reserves of other metals such as rare earth elements, which are critical for the expected growth of technology and renewable energy resources. In this study, we pair the stable Fe and O isotope compositions of magnetite samples from several IOA deposits to constrain the source reservoir of these elements in IOAs. Since magnetite constitutes up to 90 modal% of many IOAs, identifying the source of Fe and O within the magnetite may elucidate high-temperature and/or lower-temperature processes responsible for their formation. Here, we focus on the world-class Los Colorados IOA in the Chilean iron belt (CIB), and present data for magnetite from other Fe oxide deposits in the CIB (El Laco, Mariela). We also report Fe and O isotopic values for other IOA deposits, including Mineville, New York (USA) and the type locale, Kiruna (Sweden). The ranges of Fe isotopic composition (δ56Fe, 56Fe/54Fe relative to IRMM-14) of magnetite from the Chilean deposits are: Los Colorados, δ56Fe (±2σ) = 0.08 ± 0.03‰ to 0.24 ± 0.08‰; El Laco, δ56Fe = 0.20 ± 0.03‰ to 0.53 ± 0.03‰; Mariela, δ56Fe = 0.13 ± 0.03‰. The O isotopic composition (δ18O, 18O/16O relative to VSMOW) of the same Chilean magnetite samples are: Los Colorados, δ18O (±2σ) = 1.92 ± 0.08‰ to 3.17 ± 0.03‰; El Laco, δ18O = 4.00 ± 0.10‰ to 4.34 ± 0.10‰; Mariela, δ18O = (1.48 ± 0.04‰). The δ18O and δ56Fe values for Kiruna magnetite yield an average of 1.76 ± 0.25‰ and 0.16 ± 0.07‰, respectively. The Fe and O isotope data from the Chilean IOAs fit unequivocally within the range of magnetite formed by high-temperature magmatic or magmatic-hydrothermal processes (i.e., δ56Fe 0.06-0.49‰ and δ18O = 1.0-4.5‰), consistent with a high-temperature origin for Chilean IOA deposits. Additionally, minimum formation temperatures calculated by using the measured Δ18O

Overload of iron in the skin of patients with varicose ulcers. Possible contributing role of iron accumulation in progression of the disease

International Nuclear Information System (INIS)

Ackerman, Z.; Seidenbaum, M.; Loewenthal, E.; Rubinow, A.

1988-01-01

The brown pigmentation of the skin associated with venous ulceration is caused by increased local iron deposition. Diagnostic x-ray spectrometry, a method based on x-ray fluorescence analysis, was used for the noninvasive determination of iron levels in the skin of patients with venous ulceration. The mean (+/- SEM) iron concentration in the skin around the venous ulcer was elevated, compared with control values of nonulcerated skin (250 +/- 54 vs 128 +/- 39 micrograms) and compared with normal skin from the forearm (250 +/- 54 vs 14 +/- 2.5 micrograms). These data suggest that dermal iron deposition may not be an incidental by-product of increased venous pressure, but may actively perpetuate tissue damage in venous ulcerations

The Yuan vs. the Dollar: China and the United States are Already in a "Hot" War

National Research Council Canada - National Science Library

Daly, William R

2005-01-01

...., "Hot" money in FOREX) reigns as an instrument of economic and financial power. Ironically, just as the Cold War symbolically ended with the fall of the Berlin Wall, this Hot War began with another fall...

Bone marrow and chelatable iron in patients with protein energy ...

African Journals Online (AJOL)

Objectives: To examine the iron status of malnourished children by comparing bone marrow iron deposits in children with protein energy malnutrition with those in well-nourished controls, and measuring chelatable urinary iron excretion in children with kwashiorkor. Design: Bone marrow iron was assessed histologicaHy in ...

Effect of Initial Iron Content in a Zinc Bath on the Dissolution Rate of Iron During a Hot Dip Galvanizing Process

Science.gov (United States)

Lee, Sang Myung; Lee, Suk Kyu; Paik, Doo-Jin; Park, Joo Hyun

2017-04-01

The mechanism of iron dissolution and the effect of initial Fe content in a Zn bath on the dissolution rate of iron were investigated using a finger rotating method (FRM). When the initial iron content, [Fe]°, in the zinc bath was less than the solubility limit, the iron content in the zinc bath showed a rapid increase, whereas a moderate increase was observed when [Fe]° was close to the solubility limit. Based on Eisenberg's kinetic model, the mass transfer coefficient of iron in the present experimental condition was calculated to be k M = 1.2 × 10-5 m/s, which was similar to the results derived by Giorgi et al. under industrial practice conditions. A dissolution of iron occurred even when the initial iron content in the zinc bath was greater than the solubility limit, which was explained by the interfacial thermodynamics in conjunction with the morphology of the surface coating layer. By analyzing the diffraction patterns using TEM, the outermost dendritic-structured coating layer was confirmed as FeZn13 ( ζ). In order to satisfy the local equilibrium based on the Gibbs-Thomson equation, iron in the dendrite-structured phase spontaneously dissolved into the zinc bath, resulting in the enrichment of iron in front of the dendrite tip. Through the diffusion boundary layer in front of the dendritic-structured layer, dissolved Fe atoms diffused out and reacted with Zn and small amounts of Al, resulting in the formation of dross particles such as FeZn10Al x ( δ). It was experimentally confirmed that the smaller the difference between the initial iron content in the zinc bath and the iron solubility limit at a given temperature, the lower the number of formed dross particles.

Neutron activation analysis of the rare earth elements in Nasu hot springs

International Nuclear Information System (INIS)

Ikeda, Nagao; Takahashi, Naruto.

1978-01-01

Eleven rare earth elements (lanthanum, cerium, neodymium, samarium, europium, gadolinium, terbium, holmium, thulium, ytterbium and lutetium) in hot spring waters and sinter deposits in the Nasu area were determined by the neutron activation method. The rare earth elements in hot spring water were preconcentrated in ferric hydroxide precipitate and neutron-irradiated. The rare earth elements were chemically separated into lighter and heavier groups and the activity of each group was measured with a Ge(Li) detector. Distribution of the rare earth elements between the hot spring water and the sinter deposit was also discussed. (auth.)

Iron and oxygen isotope signatures of the Pea Ridge and Pilot Knob magnetite-apatite deposits, southeast Missouri, USA

Science.gov (United States)

Childress, Tristan; Simon, Adam C.; Day, Warren C.; Lundstrom, Craig C.; Bindeman, Ilya N.

2016-01-01

New O and Fe stable isotope ratios are reported for magnetite samples from high-grade massive magnetite of the Mesoproterozoic Pea Ridge and Pilot Knob magnetite-apatite ore deposits and these results are compared with data for other iron oxide-apatite deposits to shed light on the origin of the southeast Missouri deposits. The δ18O values of magnetite from Pea Ridge (n = 12) and Pilot Knob (n = 3) range from 1.0 to 7.0 and 3.3 to 6.7‰, respectively. The δ56Fe values of magnetite from Pea Ridge (n = 10) and Pilot Knob (n = 6) are 0.03 to 0.35 and 0.06 to 0.27‰, respectively. These δ18O and the δ56Fe values suggest that magnetite crystallized from a silicate melt (typical igneous δ56Fe ranges 0.06–0.49‰) and grew in equilibrium with a magmatic-hydrothermal aqueous fluid. We propose that the δ18O and δ56Fe data for the Pea Ridge and Pilot Knob magnetite-apatite deposits are consistent with the flotation model recently proposed by Knipping et al. (2015a), which invokes flotation of a magmatic magnetite-fluid suspension and offers a plausible explanation for the igneous (i.e., up to ~15.9 wt % TiO2 in magnetite) and hydrothermal features of the deposits.

Reflection seismic characterization of the Grängesberg iron deposit and its mining-induced structures, central Sweden

Science.gov (United States)

Place, Joachim; Malehmir, Alireza; Högdahl, Karin; Juhlin, Christopher; Persson Nilsson, Katarina

2014-05-01

Reflection seismic investigation has been conducted on the Grängesberg apatite iron deposit where over 150 Mt of iron ore were produced until the mine closed in 1989. The mine infrastructure with shafts and tunnels extend down to ca. 650 m below the surface. Both natural and mine induced fracture and fault systems are today water-filled (some of them extending to the surface). The disputed ore genesis of the apatite-iron ores and its exploration potential due to large remaining quantities once again attracts both scientific and commercial interests. A good understanding of the geometry of mineral deposits and their hostrock structures at depth is essential for optimizing their exploration and exploitation. In addition, deep understanding of the fracture system is vital if mining activity is resumed as these may impact the terrain stability and seismicity, which may put at risk new populated and industrial areas. To address some of these challenging issues related to the past mining and also to obtain information about the depth continuation of the existing deposit, two E-W oriented reflection lines with a total length of 3.5 km were acquired in May 2013 by Uppsala University. A weight drop mounted on an hydraulic bobcat truck (traditionally used for concrete breaking in demolition sector) was used to generate seismic signal. In order to increase the signal-to-noise ratio, several impacts were generated at each shot point and stacked together. The seismic lines intersect at high angle the Grängesberg ore body and open pit, as well as several mining-induced faults. A combination of cabled and wireless receivers placed at every 10 m was used for the data recording. Use of wireless receivers was necessary as deploying cabled sensors was not possible due to city infrastructures, roads and houses. A careful analysis of the data suggested that several field-related issues such as (1) the crooked geometry of the lines (due to the available path and road network), (2

Mathematical model of the reformer sponge iron cycle

Energy Technology Data Exchange (ETDEWEB)

Fraser, S.; Hacker, V.; Evers, B.; Hierzer, J.; Besenhard, J.O. [Graz University of Technology, Graz (Austria). Inst. for Chemical Technology of Inorganic Materials Christian Doppler Pilot-Lab. for Fuel Cell Systems

2003-07-01

An innovative hydrogen production process called the Reformer Sponge Iron Cycle (RESC), based on redox reactions of iron ore pellets, was mathematically modeled. The hydrogen is produced by blowing steam over hot iron pellets in the oxidation stage, resulting in the oxidation of the iron. Synthesis gas coming from a reformer mixed with a fraction of recycled off-gas was used to reduce the iron oxide pellets (wuestite and-or magnetite) in the reduction stage, leading once more to iron . Once the mathematical model was developed, it was verified utilizing experimental data. Based on calculations of the equilibrium gas concentrations for reformer and sponge iron reactor (SIR), the model computes mass fluxes, molar fluxes, partial pressures, and variations of them throughout the complete cycle. The recycle rate, which determines the fraction of SIR off-gas recycled and added to the input gas stream, was optimized to maximize the amount of iron oxide reduced for a certain input gas flow. 5 refs., 4 figs.

Structural and photoluminescence investigation on the hot-wire assisted plasma enhanced chemical vapor deposition growth silicon nanowires

International Nuclear Information System (INIS)

Chong, Su Kong; Goh, Boon Tong; Wong, Yuen-Yee; Nguyen, Hong-Quan; Do, Hien; Ahmad, Ishaq; Aspanut, Zarina; Muhamad, Muhamad Rasat; Dee, Chang Fu; Rahman, Saadah Abdul

2012-01-01

High density of silicon nanowires (SiNWs) were synthesized by a hot-wire assisted plasma enhanced chemical vapor deposition technique. The structural and optical properties of the as-grown SiNWs prepared at different rf power of 40 and 80 W were analyzed in this study. The SiNWs prepared at rf power of 40 W exhibited highly crystalline structure with a high crystal volume fraction, X C of ∼82% and are surrounded by a thin layer of SiO x . The NWs show high absorption in the high energy region (E>1.8 eV) and strong photoluminescence at 1.73 to 2.05 eV (red–orange region) with a weak shoulder at 1.65 to 1.73 eV (near IR region). An increase in rf power to 80 W reduced the X C to ∼65% and led to the formation of nanocrystalline Si structures with a crystallite size of <4 nm within the SiNWs. These NWs are covered by a mixture of uncatalyzed amorphous Si layer. The SiNWs prepared at 80 W exhibited a high optical absorption ability above 99% in the broadband range between 220 and ∼1500 nm and red emission between 1.65 and 1.95 eV. The interesting light absorption and photoluminescence properties from both SiNWs are discussed in the text. - Highlights: ► Growth of random oriented silicon nanowires using hot-wire assisted plasma enhanced chemical vapor deposition. ► Increase in rf power reduces the crystallinity of silicon nanowires. ► High density and nanocrystalline structure in silicon nanowires significant enhance the near IR light absorption. ► Oxide defects and silicon nanocrystallites in silicon nanowires reveal photoluminescence in red–orange and red regions.

Reconstructing the Mineralogy and Bioavailability of Dust-Borne Iron Deposited to the Southern Ocean through the Last Glacial Cycle

Science.gov (United States)

Shoenfelt, E. M.; Winckler, G.; Lamy, F.; Bostick, B. C.

2017-12-01

The iron (Fe) in dust deposited to the Fe-limited Southern Ocean plays an important role in ocean biogeochemistry and global climate. For instance, increases in dust-borne Fe deposition in the subantarctic Southern Ocean have been linked to increases in productivity and part of the CO2 drawdown of the last glacial cycle [1]. Notably, bioavailable Fe impacts productivity rather than total Fe. While it has long been understood that Fe mineralogy impacts Fe bioavailability in general, our understanding of the mineralogy of Fe in dust in specific is limited to that in modern dust sources. Reduced mineral Fe in dust has been shown to be more bioavailable than oxidized mineral iron, as it is more readily dissolved [2], and it is more easily utilized directly by a model diatom [3]. Our previous work focusing on South American dust sources shows that glacial activity is associated with higher Fe(II) fractions in dust-borne minerals, due to the physical weathering of Fe(II)-rich silicates in bedrock [3]. Thus, we hypothesize that there were higher Fe(II) fractions in dust deposited during cold glacial periods where ice sheets were more widespread. Using synchrotron-based X-ray absorption spectroscopy, we have reconstructed the mineralogy of Fe deposited to Southern Ocean sediment cores from the subantarctic South Atlantic (TN057-6/ODP Site 1090) and South Pacific (PS7/56-1) through the last glacial cycle, creating the first paleorecord of Fe mineralogy and its associated bioavailability. During cold glacial periods there is a higher fraction of reduced Fe - in the form of Fe(II) silicates - deposited to the sediments compared to warm interglacial periods. Thus, Fe(II) content is directly correlated with dust input. The presence of Fe(II) silicates rather than products of diagenesis such as pyrite suggests that these Fe(II) minerals are physically weathered from bedrock and preserved rather than produced in the sediment. This result suggests that not only was there more dust

Structural phase change and optical band gap bowing in hot wall deposited CdSe{sub x}Te{sub 1-x} thin films

Energy Technology Data Exchange (ETDEWEB)

Muthukumarasamy, N. [Department of Physics, Coimbatore Institute of Technology, Coimbatore, Tamilnadu (India); Jayakumar, S.; Kannan, M.D.; Balasundaraprabhu, R. [Thin Film Center, PSG College of Technology, Coimbatore, Tamilnadu (India)

2009-04-15

CdSe{sub x}Te{sub 1-x} thin films of different compositions have been deposited on glass substrates by hot wall deposition method under conditions very close to thermodynamical equilibrium with minimum loss of material. The structural studies carried out on the deposited films revealed that they are crystalline in nature and exhibit either cubic zinc blende or hexagonal phase or both depending on the composition of the material. The lattice parameter values for both cubic and hexagonal phases have been determined and are observed to vary with composition according to Vegard's law. The optical properties of the deposited CdSe{sub x}Te{sub 1-x} thin films have been studied using transmittance spectra. The spectra shows a sharp fall in transmittance at wavelength corresponding to the band gap of the material. The optical band gap has been determined and found to be direct allowed. The band gap has been observed to strongly depend on film composition. The variation of band gap with composition has been observed to be quadratic in nature exhibiting a bowing behaviour. (author)

Hot nuclei: high temperatures, high angular momenta

International Nuclear Information System (INIS)

Guerreau, D.

1991-01-01

A review is made of the present status concerning the production of hot nuclei above 5 MeV temperature, concentrating mainly on the possible experimental evidences for the attainment of a critical temperature, on the existence of dynamical limitations to the energy deposition and on the experimental signatures for the formation of hot spinning nuclei. The data strongly suggest a nuclear disassembly in collisions involving very heavy ions at moderate incident velocities. Furthermore, hot nuclei seem to be quite stable against rotation on a short time scale. (author) 26 refs.; 12 figs

Design, Modeling, Fabrication, and Evaluation of Thermoelectric Generators with Hot-Wire Chemical Vapor Deposited Polysilicon as Thermoelement Material

Science.gov (United States)

de Leon, Maria Theresa; Tarazona, Antulio; Chong, Harold; Kraft, Michael

2014-11-01

This paper presents the design, modeling, fabrication, and evaluation of thermoelectric generators (TEGs) with p-type polysilicon deposited by hot-wire chemical vapor deposition (HWCVD) as thermoelement material. A thermal model is developed based on energy balance and heat transfer equations using lumped thermal conductances. Several test structures were fabricated to allow characterization of the boron-doped polysilicon material deposited by HWCVD. The film was found to be electrically active without any post-deposition annealing. Based on the tests performed on the test structures, it is determined that the Seebeck coefficient, thermal conductivity, and electrical resistivity of the HWCVD polysilicon are 113 μV/K, 126 W/mK, and 3.58 × 10-5 Ω m, respectively. Results from laser tests performed on the fabricated TEG are in good agreement with the thermal model. The temperature values derived from the thermal model are within 2.8% of the measured temperature values. For a 1-W laser input, an open-circuit voltage and output power of 247 mV and 347 nW, respectively, were generated. This translates to a temperature difference of 63°C across the thermoelements. This paper demonstrates that HWCVD, which is a cost-effective way of producing solar cells, can also be applied in the production of TEGs. By establishing that HWCVD polysilicon can be an effective thermoelectric material, further work on developing photovoltaic-thermoelectric (PV-TE) hybrid microsystems that are cost-effective and better performing can be explored.

Investigation of thermal and hot-wire chemical vapor deposition copper thin films on TiN substrates using CupraSelect as precursor.

Science.gov (United States)

Papadimitropoulos, G; Davazoglou, D

2011-09-01

Copper films were deposited on oxidized Si substrates covered with TiN using a novel chemical vapor deposition reactor in which reactions were assisted by a heated tungsten filament (hot-wire CVD, HWCVD). Liquid at room temperature hexafluoroacetylacetonate Cu(I) trimethylvinylsilane (CupraSelect) was directly injected into the reactor with the aid of a direct-liquid injection (DLI) system using N2 as carrier gas. The deposition rates of HWCVD Cu films obtained on TiN covered substrates were found to increase with filament temperature (65 and 170 degrees C were tested). The resistivities of HWCVD Cu films were found to be higher than for thermally grown films due to the possible presence of impurities into the Cu films from the incomplete dissociation of the precursor and W impurities caused by the presence of the filament. For HWCVD films grown at a filament temperature of 170 degrees C, smaller grains are formed than at 65 degrees C as shown from the taken SEM micrographs. XRD diffractograms taken on Cu films deposited on TiN could not reveal the presence of W compounds originating from the filament because the relative peak was masked by the TiN [112] peak.

Hot-wire substoichiometric tungsten oxide films deposited in hydrogen environment with n-type conductivity

International Nuclear Information System (INIS)

Kostis, I; Vasilopoulou, M; Giannakopoulos, K; Papadimitropoulos, G; Davazoglou, D; Michalas, L; Papaioannou, G; Konofaos, N; Iliadis, A A; Kennou, S

2012-01-01

Substoichiometric tungsten oxide nanostructured films were synthesized by a hot-wire deposition technique in hydrogen-rich environment and characterized for their structural and electrical properties. A semiconducting behaviour was identified, allowing n-type conductivity even at room temperature which is an important result since it is well known that fully stoichiometric tungsten trioxide is nearly an insulator. Current-voltage characteristics for various temperatures were measured for tungsten oxide/Si heterostructures and analysed using proper modelling. As a result, the conduction mechanism inside the films was identified and found to be of a dual nature, with variable range hopping being dominant at near room temperatures. The saturation current was found to be thermally activated and the activation energy was calculated at 0.40 eV and the grain boundaries barrier at 150 meV. From Hall measurements it was also revealed that the dominant carriers are electrons and a carrier concentration of about 10 14 cm -3 was estimated.

Tuning temperature and size of hot spots and hot-spot arrays.

Science.gov (United States)

Saïdi, Elika; Babinet, Nicolas; Lalouat, Loïc; Lesueur, Jérôme; Aigouy, Lionel; Volz, Sébastian; Labéguerie-Egéa, Jessica; Mortier, Michel

2011-01-17

By using scanning thermal microscopy, it is shown that nanoscale constrictions in metallic microwires deposited on an oxidized silicon substrate can be tuned in terms of temperature and confinement size. High-resolution temperature maps indeed show that submicrometer hot spots and hot-spot arrays are obtained when the SiO(2) layer thickness decreases below 100 nm. When the SiO(2) thickness becomes larger, heat is less confined in the vicinity of the constrictions and laterally spreads all along the microwire. These results are in good agreement with numerical simulations, which provide dependences between silica-layer thickness and nanodot shape and temperature. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

'Hot' particles in the atmosphere (Vilnius, 1986)

International Nuclear Information System (INIS)

Lujanas, V.; Shpirkauskaite, N.

1992-01-01

After the Chernobyl accident in the atmosphere above Vilnius the alpha-and beta- 'hot' particles were discovered. The amount of particles and their size were measured by the alpha-radiography. After the exposition of nuclear plates the 'auroras' of the beta hot particles were of the size 0.37-22.2 μm. The change in time of the beta- 'hot' particles amount in the ground level air from the 25th of April to the 9th of May, 1986 was given. The amount of this particles deposited in the adult man respiratory tract was calculated. The energy of the discovered 8 'hot' alpha-particles ranged from 4.2 to 6.6 MeV. All the samples in which alpha- 'hot' particles found were taken in anticyclone conditions. (author). 1 tab., 1 ref

Non cardiopatic and cardiopatic beta thalassaemic patients: quantitative and qualitative cardiac iron deposition evaluation with MRI; Pazienti {beta} talassemici non cardiopatici e cardiopatici: valutazione quantitativa e qualitativa del deposito di ferro cardiaco con RM

Energy Technology Data Exchange (ETDEWEB)

Macarini, Luca; Marini, Stefania; Scardapane, Arnaldo [Bari Univ., Bari (Italy). DIMIMP-Sezione di Diagnostica per Immagini; Pietrapertosa, Anna [Bari Univ., Bari (Italy). MIDIM-Cattedra di Ematologia II; Ettore, Giovanni Carlo [Foggia Univ., Foggia (Italy). Cattedra di Radiologia

2005-02-01

Purpose: Cardiomyopathy is one of the major complications of {beta} thalassaemia major as a result of transfusion iron overload. The aim of our study is to evaluate with MR if there is any difference of iron deposition signal intensity (SI) or distribution between non-cardiopatic and cardiopatic thalassaemic patients in order to establish if there is a relationship between cardiopathy and iron deposition. Materials and methods: We studied 20 patients affected by {beta} thalassaemia major, of whom 10 cardiopatic and 10 non-cardiopatic, and 10 healthy volunteers as control group. Serum ferritin and left ventricular ejection fraction were calculated in thalassaemic patients. All patients were examinated using a 1.5 MR unit with ECG-gated GE cine-MR T2*-weighted, SE T1-weighted and GE T2*-weighted sequences. In all cases, using an adequate ROI, the myocardial and skeletal muscle signal intensity (SI), the myocardial/skeletal muscle signal intensity radio (SIR) and the SI average of the myocardium and skeletal muscle were calculated for every study group. The qualitative evaluation of iron deposition distribution was independently performed by three radiologists who analysed the extension, the site and the morphology of iron deposition on the MR images and reported their observations on the basis of a four-level rating scale: 0 (absent), 1 (limited), 2 (partial), 3 (widespread deposition). The results of quantitative and qualitative evaluation were analysed with statistical tests. Results: Cardiac iron deposition was found in 8/10 non-cardiopatic thalassaemic patients and in all cardiopatic thalassaemic patients. We noticed a significant SI difference (p>0.05) between the healthy volunteer control group and the thalassaemic patients with iron deposition, but no significant SI difference in iron deposition between non-cardiopatic thalassaemic patients in the areas evaluated. The qualitative evaluation revealed a different distribution of iron deposition between the two

Characteristics of Iron-Palladium alloy thin films deposited by magnetron sputtering

Science.gov (United States)

Chiu, Y.-J.; Shen, C.-Y.; Chang, H.-W.; Jian, S.-R.

2018-06-01

The microstructural features, magnetic, nanomechanical properties and wettability behaviors of Iron-Palladium (FePd) alloy thin films are investigated by using X-ray diffraction (XRD), atomic force microscopy (AFM), vibrating sample magnetometer (VSM), nanoindentation and water contact angle (CA) techniques, respectively. The FePd alloy thin films were deposited on glass substrates using a magnetron sputtering system. The post-annealing processes of FePd alloy thin films were carried out at 400 °C and 750 °C and resulted in a significant increase of both the average grain size and surface roughness. The XRD analysis showed that FePd alloy thin films exhibited a predominant (1 1 1) orientation. The magnetic field dependence of magnetization of all FePd thin films are measured at room temperature showed the ferromagnetic characteristics. The nanoindentation with continuous stiffness measurement (CSM) is used to measure the hardness and Young's modulus of present films. The contact angle (θCA) increased with increasing surface roughness. The maximum θCA of 75° was achieved for the FePd alloy thin film after annealing at 750 °C and a surface roughness of 4.2 nm.

In Vivo MRI Mapping of Brain Iron Deposition across the Adult Lifespan.

Science.gov (United States)

Acosta-Cabronero, Julio; Betts, Matthew J; Cardenas-Blanco, Arturo; Yang, Shan; Nestor, Peter J

2016-01-13

Disruption of iron homeostasis as a consequence of aging is thought to cause iron levels to increase, potentially promoting oxidative cellular damage. Therefore, understanding how this process evolves through the lifespan could offer insights into both the aging process and the development of aging-related neurodegenerative brain diseases. This work aimed to map, in vivo for the first time with an unbiased whole-brain approach, age-related iron changes using quantitative susceptibility mapping (QSM)--a new postprocessed MRI contrast mechanism. To this end, a full QSM standardization routine was devised and a cohort of N = 116 healthy adults (20-79 years of age) was studied. The whole-brain and ROI analyses confirmed that the propensity of brain cells to accumulate excessive iron as a function of aging largely depends on their exact anatomical location. Whereas only patchy signs of iron scavenging were observed in white matter, strong, bilateral, and confluent QSM-age associations were identified in several deep-brain nuclei--chiefly the striatum and midbrain-and across motor, premotor, posterior insular, superior prefrontal, and cerebellar cortices. The validity of QSM as a suitable in vivo imaging technique with which to monitor iron dysregulation in the human brain was demonstrated by confirming age-related increases in several subcortical nuclei that are known to accumulate iron with age. The study indicated that, in addition to these structures, there is a predilection for iron accumulation in the frontal lobes, which when combined with the subcortical findings, suggests that iron accumulation with age predominantly affects brain regions concerned with motor/output functions. This study used a whole--brain imaging approach known as quantitative susceptibility mapping (QSM) to provide a novel insight into iron accumulation in the brain across the adult lifespan. Validity of the method was demonstrated by showing concordance with ROI analysis and prior knowledge

Impact of microcrystalline silicon carbide growth using hot-wire chemical vapor deposition on crystalline silicon surface passivation

International Nuclear Information System (INIS)

Pomaska, M.; Beyer, W.; Neumann, E.; Finger, F.; Ding, K.

2015-01-01

Highly crystalline microcrystalline silicon carbide (μc-SiC:H) with excellent optoelectronic material properties is a promising candidate as highly transparent doped layer in silicon heterojunction (SHJ) solar cells. These high quality materials are usually produced using hot wire chemical vapor deposition under aggressive growth conditions giving rise to the removal of the underlying passivation layer and thus the deterioration of the crystalline silicon (c-Si) surface passivation. In this work, we introduced the n-type μc-SiC:H/n-type μc-SiO x :H/intrinsic a-SiO x :H stack as a front layer configuration for p-type SHJ solar cells with the μc-SiO x :H layer acting as an etch-resistant layer against the reactive deposition conditions during the μc-SiC:H growth. We observed that the unfavorable expansion of micro-voids at the c-Si interface due to the in-diffusion of hydrogen atoms through the layer stack might be responsible for the deterioration of surface passivation. Excellent lifetime values were achieved under deposition conditions which are needed to grow high quality μc-SiC:H layers for SHJ solar cells. - Highlights: • High surface passivation quality was preserved after μc-SiC:H deposition. • μc-SiC:H/μc-SiO x :H/a-SiO x :H stack a promising front layer configuration • Void expansion at a-SiO x :H/c-Si interface for deteriorated surface passivation • μc-SiC:H provides a high transparency and electrical conductivity.