R&D Nuggets

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QCD pairing in primordial nuggets

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Lugones, G.; Horvath, J. E.

2003-08-01

We analyze the problem of boiling and surface evaporation of quark nuggets in the cosmological quark-hadron transition. Recently, it has been shown that QCD pairing modifies the stability properties of strange quark matter. More specifically, strange quark matter in a color-flavor locked state was found to be absolutely stable for a much wider range of the parameters than ordinary unpaired strange quark matter (G. Lugones and J. E. Horvath, Phys. Rev. D, 66, 074017 (2002)). Assuming that primordial quark nuggets are actually formed we analyze the consequences of pairing on the rates of boiling and surface evaporation in order to determine whether they could have survived.

Detection of magnetized quark-nuggets, a candidate for dark matter.

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VanDevender, J Pace; VanDevender, Aaron P; Sloan, T; Swaim, Criss; Wilson, Peter; Schmitt, Robert G; Zakirov, Rinat; Blum, Josh; Cross, James L; McGinley, Niall

2017-08-18

Quark nuggets are theoretical objects composed of approximately equal numbers of up, down, and strange quarks and are also called strangelets and nuclearites. They have been proposed as a candidate for dark matter, which constitutes ~85% of the universe's mass and which has been a mystery for decades. Previous efforts to detect quark nuggets assumed that the nuclear-density core interacts directly with the surrounding matter so the stopping power is minimal. Tatsumi found that quark nuggets could well exist as a ferromagnetic liquid with a ~10 12 -T magnetic field. We find that the magnetic field produces a magnetopause with surrounding plasma, as the earth's magnetic field produces a magnetopause with the solar wind, and substantially increases their energy deposition rate in matter. We use the magnetopause model to compute the energy deposition as a function of quark-nugget mass and to analyze testing the quark-nugget hypothesis for dark matter by observations in air, water, and land. We conclude the water option is most promising.

Quantification of Microtexture at Weld Nugget of Friction Stir-Welded Carbon Steel

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Husain, Md M.; Sarkar, R.; Pal, T. K.; Ghosh, M.; Prabhu, N.

2017-05-01

Friction stir welding of C-Mn steel was carried out under 800-1400 rpm tool rotation. Tool traversing speed of 50 mm/min remained same for all joints. Effect of thermal state and deformation on texture and microstructure at weld nugget was investigated. Weld nugget consisted of ferrite + bainite/Widmanstatten ferrite with different matrix grain sizes depending on peak temperature. A texture around ( ϕ 2 = 0°, φ = 30°, ϕ 2 = 45°) was developed at weld nugget. Grain boundary misorientation at weld nugget indicated that continuous dynamic recrystallization influenced the development of fine equiaxed grain structure. Pole figures and orientation distribution function were used to determine crystallographic texture at weld nugget and base metal. Shear texture components D1, D2 and F were present at weld nugget. D1 shear texture was more prominent among all. Large number of high-angle grain boundaries ( 60-70%) was observed at weld nugget and was the resultant of accumulation of high amount of dislocation, followed by subgrain formation.

Fortification of Sardine Fish Oil from By-product of Canning Processing into Beef Meatball and Chicken Nugget

OpenAIRE

Teti Estiasih; Endang Trowulan; Widya Dwi Rukmi

2017-01-01

One source of ω-3 fatty acids is a by-product of lemuru canning processing that can be used for fortification.  Generally, fortification uses fish oil microcapsule but it is more expensive than direct fortification.  In this study, fish oil from a by-product of lemuru canning processing was directly fortified into beef meatball and chicken nugget at concentration of 0, 2, 4, and 6% (w/w).  Oxidation level, free fatty acid content, colour, lightness, texture, and sensory acceptance by triangle...

Penggunaan Bahan Pengisi terhadap Mutu Nugget Vegetarian Berbahan Dasar Tahu dan Tempe

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Syarifah Rohaya

2013-02-01

Full Text Available The purpose of this study was to compare different sources of flours and protein sources based on soya bean products in producing vegetarian nugget. Factorial experimental design with three replications was employed where wheat, sweet potato, sago and banana flour as one factor, and tempeh and tofu as another factor. Moisture and raw protein content of vegetarian nuggets produced in this study was in accordance with the Indonesia Standard (SNI. Moisture was less than 60 percent and raw protein was above 12 percent. The highest organoleptic test was obtained from the nugget made of the combination of sago as filler and tofu as protein source. The nugget contained 60.00, 14.89, 28.89 and 2.00 percent of moisture, raw protein, raw fat and ash content, respectively. The organoleptic scores were 2.70, 3.58, 3.50, 3.53 and 3.62 for color, aroma, taste, texture and springiness, respectively. Keywords: nugget, vegetarian nugget, filler

Evaluation of process parameters in the industrial scale production of fish nuggets

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Adriane da Silva

2011-06-01

Full Text Available This work reports the use of experimental design for the assessment of the effects of process parameters on the production of fish nuggets in an industrial scale environment. The effect of independent factors on the physicochemical and microbiological parameters was investigated through a full 24 experimental design. The studied factors included the temperature of fish fillet and pulp in the mixer, the temperature of the added fat, the temperature of water and the ratio of protein extraction time to emulsion time. The physicochemical analyses showed that the higher temperature of the pulp and fillet of fish, the lower the protein in the final product. Microbiological analyses revealed that the counting of Staphylococcus coagulase positive, total and thermo-tolerant coliforms were in accordance with the current legislation.

Antioxidant and antimicrobial effects of kordoi (Averrhoa carambola) fruit juice and bamboo (Bambusa polymorpha) shoot extract in pork nuggets.

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Thomas, R; Jebin, N; Saha, R; Sarma, D K

2016-01-01

Pork nuggets with 'very good' acceptability was processed by incorporating kordoi (Averrhoa carambola) fruit juice and bamboo (Bambusa polymorpha) shoot extract, and their physical, chemical, microbiological and sensorial characteristics were evaluated during 35 days storage under refrigeration. Addition of kordoi fruit juice (4%) and bamboo shoot extract (6%) had a significant effect on the pH, moisture, protein, fat, fiber, instrumental color values and texture profiles of nuggets. Nuggets with juice and extract had significantly lower TBARS values towards the end of the storage period compared to the control. Microbial and sensory qualities of nuggets were significantly improved by the addition of juice and extract. Incorporation of juice and extract at 4% and 6% levels, respectively, increased the storage life of pork nuggets by at least two weeks, i.e. from 21 days to 35 days at 4 ± 1 °C compared to the control. Copyright © 2015 Elsevier Ltd. All rights reserved.

Weld nugget formation in resistance spot welding of new lightweight sandwich material

DEFF Research Database (Denmark)

Sagüés Tanco, J.; Nielsen, Chris Valentin; Chergui, Azeddine

2015-01-01

Weldability of a new lightweight sandwich material, LITECOR®, by resistance spot welding is analyzed by experiments and numerical simulations. The spot welding process is accommodated by a first pulse squeezing out the non-conductive polymer core of the sandwich material locally to allow metal......–metal contact. This is facilitated by the use of a shunt tool and is followed by a second pulse for the actual spot welding and nugget formation. A weldability lobe in the time-current space of the second pulse reveals a process window of acceptable size for automotive assembly lines. Weld growth curves...... with experimental results in the range of welding parameters leading to acceptable weld nugget sizes. The validated accuracy of the commercially available software proves the tool useful for assisting the choice of welding parameters....

Beyond WIMPs: the Quark (Anti Nugget Dark Matter

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Zhitnitsky Ariel

2017-01-01

Full Text Available We review a testable dark matter (DM model outside of the standard WIMP paradigm. The model is unique in a sense that the observed ratio Ωdark ≃ Ωvisible for visible and dark matter densities finds its natural explanation as a result of their common QCD origin when both types of matter (DM and visible are formed during the QCD phase transition and both are proportional to single dimensional parameter of the system, Λqcd. We argue that the charge separation effect also inevitably occurs during the same QCD phase transition in the presence of the CP odd axion field a(x. It leads to preferential formation of one species of nuggets on the scales of the visible Universe where the axion field a(x is coherent. A natural outcome of this preferential evolution is that only one type of the visible baryons (not anti- baryons remain in the system after the nuggets complete their formation. Unlike conventional WIMP dark matter candidates, the nuggets and anti-nuggets are strongly interacting but macroscopically large objects. The rare events of annihilation of the anti-nuggets with visible matter lead to a number of observable effects. We argue that the relative intensities for a number of measured excesses of emission from the centre of galaxy (covering more than 11 orders of magnitude are determined by standard and well established physics. At the same time the absolute intensity of emission is determined by a single new fundamental parameter of the theory, the axion mass, 10−6eV ≲ ma ≲ 10−3eV. Finally, we comment on implications of these studies for the axion search experiments, including microwave cavity and the Orpheus experiments.

Nugget Structure Evolution with Rotation Speed for High-Rotation-Speed Friction-Stir-Welded 6061 Aluminum Alloy

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Zhang, H. J.; Wang, M.; Zhu, Z.; Zhang, X.; Yu, T.; Wu, Z. Q.

2018-03-01

High-rotation-speed friction stir welding (HRS-FSW) is a promising technique to reduce the welding loads during FSW and thus facilitates the application of FSW for in situ fabrication and repair. In this study, 6061 aluminum alloy was friction stir welded at high-rotation speeds ranging from 3000 to 7000 rpm at a fixed welding speed of 50 mm/min, and the effects of rotation speed on the nugget zone macro- and microstructures were investigated in detail in order to illuminate the process features. Temperature measurements during HRS-FSW indicated that the peak temperature did not increase consistently with rotation speed; instead, it dropped remarkably at 5000 rpm because of the lowering of material shear stress. The nugget size first increased with rotation speed until 5000 rpm and then decreased due to the change of the dominant tool/workpiece contact condition from sticking to sliding. At the rotation speed of 5000 rpm, where the weld material experienced weaker thermal effect and higher-strain-rate plastic deformation, the nugget exhibited relatively small grain size, large textural intensity, and high dislocation density. Consequently, the joint showed superior nugget hardness and simultaneously a slightly low tensile ductility.

Antioxidant Efficacy of Litchi (Litchi chinensis Sonn.) Pericarp Extract in Sheep Meat Nuggets

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Das, Arun K.; Rajkumar, Vincent; Nanda, Pramod K.; Chauhan, Pranav; Pradhan, Soubhagya R.; Biswas, Subhasish

2016-01-01

In the present study, the efficacy of litchi fruit pericarp (LFP) extract (0.5%, 1.0% and 1.5% concentration) in retarding lipid oxidation of cooked sheep meat nuggets was evaluated and compared to butylated hydroxyl toluene (BHT, 100 ppm). The total phenolic content and antioxidant potential of LFP extracts were determined. The thiobarbituric acid reactive substance (TBARS) values were evaluated to assess the potential of LFP extracts as natural antioxidants for oxidative stability of cooked nuggets during 12 days of refrigerated storage. Results show that total phenolics content in 10 mg LFP powder was comparable to 100 ppm BHT, but 15 mg LFP powder had significantly higher (p < 0.05) total phenolics content and reducing power than the synthetic antioxidant. LFP extract did not affect pH, cooking yield and the sensory attributes of cooked nuggets. Non-treated control and nuggets with 1.0% LFP extract had significantly lower total phenolics than nuggets with 1.5% extract and BHT. TBARS values were significantly lower (p < 0.05) throughout the storage period in cooked meat nuggets containing either LFP extract or BHT than in non-treated control. Results indicate that LFP extracts are promising sources of natural antioxidants and can potentially be used as functional food additives in meat products at 1.5% without affecting products’ acceptability. PMID:27213457

Antioxidant Efficacy of Litchi (Litchi chinensis Sonn. Pericarp Extract in Sheep Meat Nuggets

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Arun K. Das

2016-05-01

Full Text Available In the present study, the efficacy of litchi fruit pericarp (LFP extract (0.5%, 1.0% and 1.5% concentration in retarding lipid oxidation of cooked sheep meat nuggets was evaluated and compared to butylated hydroxyl toluene (BHT, 100 ppm. The total phenolic content and antioxidant potential of LFP extracts were determined. The thiobarbituric acid reactive substance (TBARS values were evaluated to assess the potential of LFP extracts as natural antioxidants for oxidative stability of cooked nuggets during 12 days of refrigerated storage. Results show that total phenolics content in 10 mg LFP powder was comparable to 100 ppm BHT, but 15 mg LFP powder had significantly higher (p < 0.05 total phenolics content and reducing power than the synthetic antioxidant. LFP extract did not affect pH, cooking yield and the sensory attributes of cooked nuggets. Non-treated control and nuggets with 1.0% LFP extract had significantly lower total phenolics than nuggets with 1.5% extract and BHT. TBARS values were significantly lower (p < 0.05 throughout the storage period in cooked meat nuggets containing either LFP extract or BHT than in non-treated control. Results indicate that LFP extracts are promising sources of natural antioxidants and can potentially be used as functional food additives in meat products at 1.5% without affecting products’ acceptability.

Guava ( L. Powder as an Antioxidant Dietary Fibre in Sheep Meat Nuggets

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Arun K. Verma

2013-06-01

Full Text Available This study was conducted to explore the antioxidant potential and functional value of guava (Psidium guajava L. powder in muscle foods. Guava powder was used as a source of antioxidant dietary fibre in sheep meat nuggets at two different levels i.e., 0.5% (Treatment I and 1.0% (Treatment II and its effect was evaluated against control. Guava powder is rich in dietary fibre (43.21%, phenolics (44.04 mg GAE/g and possesses good radical scavenging activity as well as reducing power. Incorporation of guava powder resulted in significant decrease (p<0.05 in pH of emulsion and nuggets, emulsion stability, cooking yield and moisture content of nuggets while ash and moisture content of emulsion were increased. Total phenolics, total dietary fibre (TDF and ash content significantly increased (p<0.05 in nuggets with added guava powder. Product redness value was significantly improved (p<0.05 due to guava powder. Textural properties did not differ significantly except, springiness and shear force values. Guava powder was found to retard lipid peroxidation of cooked sheep meat nuggets as measured by TBARS number during refrigerated storage. Guava powder did not affect sensory characteristics of the products and can be used as source of antioxidant dietary fibre in meat foods.

High energy cosmic ray signature of quark nuggets

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Audouze, J.; Schaeffer, R.; Silk, J.

1985-01-01

It has been recently proposed that dark matter in the Universe might consist of nuggets of quarks which populate the nuclear desert between nucleons and neutron star matter. It is further suggested that the Centauro events which could be the signature of particles with atomic mass A approx. 100 and energy E approx. 10 to 15th power eV might also be related to debris produced in the encounter of two neutron stars. A further consequence of the former proposal is examined, and it is shown that the production of relativistic quark nuggets is accompanied by a substantial flux of potentially observable high energy neutrinos.

Effect on spot welding variables on nugget size and bond strength of 304 austenitic stainless steel

International Nuclear Information System (INIS)

Charde, Nachimani

2012-01-01

Resistance spot welding (RSW) has revolutionized mechanical assembly in the automotive industry since its introduction in the early 1970s. Currently, one mechanical assembly in five is welded using spot welding technology, with welding of stainless steel sheet becoming increasingly common. Consequently, this research paper examines the spot welding of 2 mm thick 304 austenitic stainless steel sheet. The size of a spot weld nugget is primarily determined by the welding parameters: welding current, welding time, electrode force and electrode tip diameter However, other factors such as electrode deformation, corrosion, dissimilar materials and material properties also affect the nugget size and shape. This paper analyzes only the effects of current, weld time and force variations with unchanged electrode tip diameter. A pneumatically driven 75kVA spot welder was used to accomplish the welding process and the welded samples were subjected to tensile, hardness and metallurgical testing to characterize the size and shape of the weld nugget and the bond strength.

PCR-RFLP Using BseDI Enzyme for Pork Authentication in Sausage and Nugget Products

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Y. Erwanto

2011-04-01

Full Text Available A polymerase chain reaction–restriction fragment length polymorphism (PCR–RFLP using BseDI restriction enzyme had been applied for identifying the presence of pork in processed meat (beef sausage and chicken nugget including before and after frying. Pork sample in various levels (1%, 3%, 5%, 10%, and 25 % was prepared in a mixture with beef and chicken meats and processed for sausage and nugget. The primers CYTb1 and CYTb2 were designed in the mitochondrial cytochrome b (cyt b gene and PCR successfully amplified fragments of 359 bp. To distinguish existence of porcine species, the amplified PCR products of mitochondrial DNA were cut by BseDI restriction enzyme. The result showed pig mitochondrial DNA was cut into 131 and 228 bp fragments. The PCR-RFLP species identification assay yielded excellent results for identification of porcine species. It is a potentially reliable technique for pork detection in animal food processed products for Halal authentication.

Charges on Strange Quark Nuggets in Space

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Teplitz, V.; Bhatia, A.; Abers, E.; Dicus, D.; Repko, W.; Rosenbaum, D.

2008-01-01

This viewgraph presentation reviews the work done in calculations to find ZN such that the rate of ambient photons ionize the strange quark nuggets (SQNs) Electrons are equal to the rate of ambient e's to replace them.

The Effects of Using Seaweed (E. Cottonii on Physical Quality and Organoleptic of Chicken Nuggets

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Djalal Rosyidi

2012-02-01

Full Text Available This research was experimental method with Completely Random Design.  Seaweed used to chicken nuggets in the vary concentration, namely: 0% (F0, 10% (F1, 20% (F2, 30% (F3, 40% (F4. The observed variables were texture, water holding capacity (WHC, pH, and organoleptic quality of chicken nuggets. Collected data were analyzed using analisys variation method and followed by Duncan analysis if the result on the previous analysis showed significant difference. The  result  showed  that  chicken  nuggets  using  seaweed  gave highly significant effect  (P<0.01 on  texture, WHC, pH, and   organoleptic quality. The best result was chicken nuggets made with used of seaweed  10%;  7.97 N of texture; 4.50% of WHC; 6.16 of pH; 6.98 of texture organoleptic score; and 6.26 of taste organoleptic score. The conclusion of this research was the using of seaweed to chicken nuggets gave a significant effect on  texture, WHC, pH, and organoleptic quality. Based on the result, it suggested that using 10% of seaweed to make chicken nugeets.   Keyword : water holding capacity, chicken nuggets, seaweed

The effect of food type (fish nuggets or French fries) on oil blend degradation during repeated frying.

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Flores-Álvarez, María Del Carmen; Molina-Hernández, Erika F; Hernández-Raya, José Concepción; Sosa-Morales, María Elena

2012-11-01

Oil that is reused multiple times for deep frying goes through changes in chemical composition and physical characteristics, affecting the quality of the fried foods. In this study, the effect of the food type (fish nuggets or French fries) on the degradation of an oil blend during the deep-fat frying of each food at 180°C during 12 days was determined, and the characteristics of the fried products were evaluated. The degradation of oil during repeated use was relatively faster when fish nuggets were fried than when French fries were fried, as higher values of total polar compounds were obtained. The results are useful for producers of French fries and fish nuggets, such as restaurants or fast foods sellers, providing them with practical guidelines within the permitted values established by the regulatory authorities. The studied foods have high economic importance and are different in their composition. Under the studied conditions, the tested oil blend may be used during 4 d (4 h per day) with a daily replenishment, without discarding the oil when frying fish nuggets, and must be discarded after 8 d when French fries are processed. This suggestion allows preparing safe fried foods for consumers. © 2012 Institute of Food Technologists®

A method for recovery of iron, titanium, and vanadium from vanadium-bearing titanomagnetite

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Zhang, Yi-min; Wang, Li-na; Chen, De-sheng; Wang, Wei-jing; Liu, Ya-hui; Zhao, Hong-xin; Qi, Tao

2018-02-01

An innovative method for recovering valuable elements from vanadium-bearing titanomagnetite is proposed. This method involves two procedures: low-temperature roasting of vanadium-bearing titanomagnetite and water leaching of roasting slag. During the roasting process, the reduction of iron oxides to metallic iron, the sodium oxidation of vanadium oxides to water-soluble sodium vanadate, and the smelting separation of metallic iron and slag were accomplished simultaneously. Optimal roasting conditions for iron/slag separation were achieved with a mixture thickness of 42.5 mm, a roasting temperature of 1200°C, a residence time of 2 h, a molar ratio of C/O of 1.7, and a sodium carbonate addition of 70wt%, as well as with the use of anthracite as a reductant. Under the optimal conditions, 93.67% iron from the raw ore was recovered in the form of iron nugget with 95.44% iron grade. After a water leaching process, 85.61% of the vanadium from the roasting slag was leached, confirming the sodium oxidation of most of the vanadium oxides to water-soluble sodium vanadate during the roasting process. The total recoveries of iron, vanadium, and titanium were 93.67%, 72.68%, and 99.72%, respectively.

KOMPOSISI KIMIA DAN ORGANOLEPTIK FORMULA NUGGET BERBASIS TEPUNG TEMPE DAN TEPUNG RICEBRAN

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Sufiati Bintanah

2014-07-01

Full Text Available Abstrak Di Indonesia terjadi perubahan pola penyakit dari infeksi dan kekurangan gizi ke degeneratif dan kanker akibat perubahan gaya hidup dan pola makan  tinggi lemak dan rendah serat serta modernisasi pola hidup. Tempe kedelai merupakan bahan makanan yang dapat menurunkan trigliserida, kolesterol total, kolesterol LDL, serta meningkatkan kolesterol HDL. Bekatul juga merupakan bahan makanan yang dapat menurunkan kadar lemak darah karena mengandung oryzanol, tokoferol, dan asam felurat. Tujuan dari penelitian ini adalah untuk menyeleksi formula nugget berdasarkan karakteristik fisik, kimia dan organoleptik serta aktifitas antioksidan. Jenis penelitian ini adalah penelitian diskriptif dengan perlakuan formulasi tepung tempe dan tepung ricebran sebanyak 10 formula. Analisis komposisi kimia dilakukan terhadap bahan mentah dan nugget meliputi analisis protein (mikro kjedhl, lemak (soxhlet, air (oven, karbohidrat (Luff Schoorl l, penetapan kadar Vitamin E (Alfa-Tokoferol, analisa aktivitas anti bakteri metode difusi agar. Pengujian organoleptik menggunakan metode scoring. Hasil menunjukkan nugget dengan formula tepung tempe 50% dan tepung bekatul 50% (formula A7, mempunyai komposisi kimia terbaik yaitu protein 19,5g%, lemak 18.33g%, air 35.59%, abu 1,62%, serat kasar 9,57g%, Karbohidrat 25,41 g%, Vitamin E 148,92 µg/g, aktifitas antioksidan 197,1 µg/ml. Hasil pengujian organoleptik terhadap warna, rasa, aroma maupun tekstur yang paling disuka pada formula A7. Kesimpulan: Optimasi tepung tempe dan rice bran yang diterima berdasarkan sifat fisik, organoleptik dan analisa zat gizi adalah dengan perlakuan sangrai 20 menit. Formula nugget yang optimum A7 dengan perbandingan tepung tempe dan rice bran 50:50 g. Kata Kunci: Komposisi Kimia, Organoleptik, Formula Nugget, Tepung Tempe, Ricebran Abstract In Indonesia, there has been a changing disease pattern from infectious and food deficiency diseases to degenerative and cancerous diseases. Soy bean cake

Quality Evaluation of Chicken Nugget Formulated with Various Contents of Chicken Skin and Wheat Fiber Mixture

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Kim, Hack-Youn; Kim, Kon-Joong; Lee, Jong-Wan; Kim, Gye-Woong; Choe, Ju-Hui; Kim, Hyun-Wook; Yoon, Yohan; Kim, Cheon-Jei

2015-01-01

This study aimed to investigate the effects of various mixtures of the chicken skin and wheat fiber on the properties of chicken nuggets. Two skin and fiber mixtures (SFM) were prepared using the following formulations; SFM-1: chicken skin (50%), wheat fiber (20%), and ice (30%); and SFM-2: chicken skin (30%), wheat fiber (20%), and ice (50%). Chicken nugget samples were prepared by adding the following amounts of either SFM-1 or SFM-2: 0%, 2.5%, 5%, 7.5%, and 10%. The water content for samples formulated with SFM-1 or SFM-2 was higher than in the control (pchicken nuggets was higher than that of cooked chicken nuggets for all the samples tested. Chicken nuggets formulated with SFM-1 and SFM-2 displayed higher cooking yields than the control sample. The hardness of the control sample was also lower than the samples containing SFM-1 and SFM-2. The sensory evaluation showed no significant differences between the control and the samples containing SFM. Therefore, the incorporation of a chicken skin and wheat fiber mixture improved the quality of chicken nuggets. PMID:26761796

Cosmological axion and a quark nugget dark matter model

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Ge, Shuailiang; Liang, Xunyu; Zhitnitsky, Ariel

2018-02-01

We study a dark matter (DM) model offering a very natural explanation of two (naively unrelated) problems in cosmology: the observed relation ΩDM˜Ωvisible and the observed asymmetry between matter and antimatter in the Universe, known as the "baryogenesis" problem. In this framework, both types of matter (dark and visible) have the same QCD origin, form at the same QCD epoch, and are proportional to one and the same dimensional parameter of the system, ΛQCD, which explains how these two naively distinct problems could be intimately related, and could be solved simultaneously within the same framework. More specifically, the DM in this model is composed by two different ingredients: the (well-studied) DM axions and the (less-studied) quark nuggets made of matter or antimatter. We focus on the quantitative analysis of the relation between these two distinct components contributing to the dark sector of the theory determined by ΩDM≡[ΩDM(nuggets)+ΩDM(axion)] . We argue that the nuggets' DM component always traces the visible matter density, i.e., ΩDM(nuggets)˜Ωvisible , and this feature is not sensitive to the parameters of the system such as the axion mass ma or the misalignment angle θ0. It should be contrasted with conventional axion production mechanisms due to the misalignment when ΩDM(axion) is highly sensitive to the axion mass ma and the initial misalignment angle θ0. We also discuss the constraints on this model related to the inflationary scale HI, nonobservation of the isocurvature perturbations and the tensor modes. We also comment on some constraints related to various axion search experiments.

Evaluation of the proximate quality of the combination of Tuna (Thunnus albacares) and white oyster mushroom (Pleurotus ostreatus) nuggets

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Yufidasari, H. S.; Prihanto, A. A.; Nurdiani, R.; Jaziri, A. A.

2018-04-01

Nugget is a processed meat product which has great market demand but need variations to increase its nutritional content. Tuna is rich in omega-3 protein, vitamins, and minerals. White oyster mushrooms have high nutritional content which are about 23-33% protein, 36-68 % carbohydrates and 12-22 % amino acids. The purpose of this research is to evaluate the chemical quality of Tuna nugget (Thunnus albacores) with combination of white oyster mushroom (Pleurotus ostreatus). Complete Randomized Design (RAL) with parameters of Tuna and white oyster mushroom formulation, TJ1 (70 % Tuna: 30 % white oyster mushroom), TJ2 (50 % Tuna: 50 % white oyster mushroom), TJ3 (30 % Tuna: 70 % white oyster mushroom), and Control or K Treatment (100 % Tuna) is used. Results of Tuna nuggets with white oyster mushroom combination showed the highest value of water content in TJ3 50.14 %, protein K 19.6 %, fat TJ3 22.98 %, ash K 3.99 % and 2.47 % crude fiber. From these results, there is a need for further research on fat, ash and coarse fiber content that is used in the manufacture of fish nuggets combined with oyster mushrooms because it failed to meet Indonesian National Standard (SNI).

Effect of fermented bamboo shoot on the quality and shelf life of nuggets prepared from desi spent hen

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Ankur Das

Full Text Available Aim: An investigation was carried out to prepare nuggets from the relatively tough and fibrous meat of desi spent hen using fermented bamboo shoot as a phytopreservative in order to enhance the physico-chemical, microbiological and keeping quality of the nuggets. Materials and Methods: Lean meat of desi spent hen was minced and blended along with other non-meat ingredients and fermented bamboo shoot @10%. The emulsion was filled in metallic moulds and steam cooked and cut into pieces. Ready-toeat nuggets thus prepared were packed in sterilized LDPE zip bags and stored at 4±1°C up-to 15 days for quality evaluation. Emulsion stability (%, cooking yield (%, a and proximate composition were studied on the day of preparation, while estimation of pH, TBA values, microbial load and sensory evaluation were carried out at 5 days interval and up-to 15th day of storage. Results: The emulsion stability (%, cooking yield (%, moisture (%, crude protein (% and total ash (% of FBS treated nuggets differed significantly (p<0.01 from the control products. Storage studies revealed significantly lower (p<0.01 pH, TBA value, total plate count, psychrophillic count and counts for yeast and moulds in FBS treated nuggets in comparison to control products. Both control and treated nuggets exhibited gradual loss of panel ratings during the storage period (4±1°C for 15 days, however, nuggets containing fermented bamboo shoot revealed significantly higher (p<0.01 mean sensory scores in terms of flavour, texture, juiciness and overall acceptability. Conclusion: Nuggets with better physico-chemical and shelf life can be prepared with incorporation of fermented bamboo shoot @10% (w/w to the nugget emulsion. [Vet World 2013; 6(7.000: 419-423

Influence of quark nuggets on primordial nucleosynthesis

International Nuclear Information System (INIS)

Schaeffer, R.; Delbourgo-Salvador, P.; Audouze, J.

1985-03-01

There are many indications that the baryonic content of the universe is rather low. This has been suggested that small droplets, ''nuggets'', of quark matter could exist and be stable or at least metastable with respect to their decay into ordinary nucleons or nuclei. This hypothesis is discussed here

The impact of cooking methods on the nutritional quality and safety of chicken breaded nuggets.

Science.gov (United States)

Gonçalves Albuquerque, Tânia; Oliveira, M Beatriz P P; Sanches-Silva, Ana; Cristina Bento, Ana; Costa, Helena S

2016-06-15

The impact of cooking methods (industrial pre-frying, deep-fat frying and baking) on the nutritional quality and safety of chicken breaded nugget samples from supermarket and commercial brands was evaluated. The changes in the quality characteristics (nutritional composition, fatty acids profile, cholesterol and salt) of the fried food and frying oil, after ten consecutive frying operations, were evaluated. The total fat content of nuggets varied between 10.9 and 22.7 g per 100 g of edible portion and the salt content ranged from 0.873 to 1.63 g per 100 g. Taking into account one portion of nuggets, the daily intake of salt can reach 49%, which can have a significant impact on the health of those who regularly consume this type of food, especially considering the prevalence of hypertension around the world. The analysed chicken breaded nuggets are rich in unsaturated fatty acids, which have been related with potential health benefits, namely regarding cardiovascular diseases. The cholesterol content of baked samples was two times higher when compared with the fried ones. The trans fatty acids and polar compounds contents of the frying oil used for frying significantly increased, but the values were still away from the maximum recommended by legal entities for its rejection. From a nutritional point of view, it is possible to conclude that the applied cooking methods can significantly influence the nutritional quality and safety of the analysed chicken breaded nuggets. This study will contribute to important knowledge on how the applied cooking methods can change the nutritional quality and safety of foods, namely of chicken nuggets, and can be very useful for dietary recommendations and nutritional assessment.

The use of ionizing radiation as a method of eliminating pathogenic microorganism in Chicken Nuggets

International Nuclear Information System (INIS)

Kaempffer R, Daniela; Espinoza B, Juan; Maier N, Liliana; Torres, Ximena; Zarate S, Herman

2005-01-01

In order to determine an effective treatment of ionizing energy on chicken nuggets a study was developed so as to eliminate pathogens such as Escherichia coli and Salmonella enteritidis. The experiment included 3 types of analyses: aerobic plate count, organoleptic evaluation and chemical analyses. A total of 144 frozen nuggets (-18 o C )were analyzed and divided into two equal groups for proceeding with artificial contamination.Each nugget -weighting 25 g -was put into sealed polietilene bags.The two sample groups were sterilized with irradiation doses of 25 kGy, then inoculated with Escherichia coli O157:H7 strain ATCC 25922 ISP (Instituto de Salud Publica) and Salmonella enteritidis strain ATCC 1833-99 ISP. The samples of each group were treated with gamma irradiation (Co 60 ), with doses of 0,3;0,6 and 0,9 kGy,except for one group (control) which was not irradiated, and stored for 24 hours, 30 and 60 days post radiation. The D 10 values mid-point were found for the Escherichia coli to be 0,242 kGy and 0,295 kGy for the Salmonella enteritidis. A third group, composed by 9 randomly selected nuggets without sterilization was chosen to determine the total aerobic plate counts, resulting in an initial count of 6,15x 10 4 ufc/g. The sensory analysis of nuggets was done by means of a trained sensorial panel who evaluated samples with 0,75 and 1,5 kGy and those of the control group non irradiated. Each person tasted the whole sample (25 g)and evaluated: appearance, color, odor, bitterness, texture, flavor and acceptability. Statistically, none attribute showed significant differences (p≤0.05)between the radiated samples and the control group, concluding that the level of the nugget acceptability was qualified as very good. The chemical analysis of nuggets was done in two groups: A control group and an irradiated group with 1.5 kGy. It evaluated the percentage of proteins, fats, ashes, humidity and carbohydrates. Statistically, none of the nutrients showed significant

The Behaviour of Some Vegetable-Based Materials Used as Edible Coating on Chicken Nuggets

Directory of Open Access Journals (Sweden)

Osman Kılınççeker

2011-01-01

Full Text Available In this study, chicken nuggets were predusted with zein or soy protein isolate (SPI as the first coating. Next they were coated with 0.1, 0.2 or 0.3 % carboxymethylcellulose (CMC batters as the second coating, and then breaded with bread crumbs. Finally, they were fried at 190 °C for 2, 4 or 6 min. Predusting materials were found to enhance some physical, chemical and sensorial properties of nuggets after frying. In particular, using SPI was more advantageous than zein. It increased penetrometer values and sensorial scores as it decreased moisture loss. The performance values of batter materials were improved compared to the control. Also, the yield, moisture rate, penetrometer and general appearance values decreased as the frying time increased. During this period, frying loss and fat absorption increased. Results showed that the best coating process was using SPI as predusting material, 0.1 % CMC for batter, and 2 to 4 min of frying time.

Quality and storability of chicken nuggets formulated with green banana and soybean hulls flours.

Science.gov (United States)

Kumar, Vinay; Biswas, Ashim Kumar; Sahoo, Jhari; Chatli, Manish Kumar; Sivakumar, S

2013-12-01

The present study was envisaged to investigate the effect of green banana (GBF) and soybean hulls flours (SHF) on the physicochemical characteristics, colour, texture and storage stability of chicken meat nuggets. The addition of GBF and SHF in the nugget formulations was effective in sustaining desired cooking yield and emulsion stability besides nutritional benefits. Protein and fat contents were decreased (p > 0.05), but fibers and ash contents was increased (p  0.05%) than control and treatments. Lipid oxidation products, however, unaffected (p > 0.05) but increased in all samples over storage time. Flour treatments showed a positive impact in respect to microbiological quality, however, sensory evaluation indicated comparable scores for all attributes at all times. So, incorporation of GBF and SHF in the formulation could improve the quality and storage stability of chicken nuggets.

Refractory metal nuggets in different types of cosmic spherules.

Digital Repository Service at National Institute of Oceanography (India)

Rudraswami, N.G.; ShyamPrasad, M.; Plane, J.M.C.; Berg, T.; Feng, W.; Balgar, S.

a fremdling-like object in a cosmic spherule which has a nugget encased in Fe–Ni and sulfide phases, similar to those typically observed in CAIs of CV or CO chondrites. The atmospheric entry for this rare cosmic spherule appears to have taken place...

Utilization of waste polyethylene terephthalate as a reducing agent in the reduction of iron ore composite pellets

Science.gov (United States)

Polat, Gökhan; Birol, Burak; Sarıdede, Muhlis Nezihi

2014-08-01

The increasing consumption of plastics inevitably results in increasing amounts of waste plastics. Because of their long degradation periods, these wastes negatively affect the natural environment. Numerous studies have been conducted to recycle and eliminate waste plastics. The potential for recycling waste plastics in the iron and steel industry has been underestimated; the high C and H contents of plastics may make them suitable as alternative reductants in the reduction process of iron ore. This study aims to substitute plastic wastes for coal in reduction melting process and to investigate their performance during reduction at high temperature. We used a common type of waste plastic, polyethylene terephthalate (PET), because of its high carbon and hydrogen contents. Composite pellets containing PET wastes, coke, and magnetite iron ore were reduced at selected temperatures of 1400 and 1450°C for reduction time from 2 to 10 min to investigate the reduction melting behavior of these pellets. The results showed that an increased temperature and reduction time increased the reduction ratio of the pellets. The optimum experimental conditions for obtaining metallic iron (iron nuggets) were reduction at 1450°C for 10 min using composite pellets containing 60% PET and 40% coke.

Using the Moon and Mars as Giant Detectors for Strange Quark Nuggets

Science.gov (United States)

Chui, Talso; Penanen, Konstantin; Strayer, Don; Banerdt, Bruce; Tepliz, Vigdor; Herrin, Eugene

2004-01-01

On the Earth, the detectability of small seismic signals is limited by pervasive seismic background noise, caused primarily by interactions of the atmosphere and oceans with the solid surface. Mars, with a very thin atmosphere and no ocean is expected to have a noise level at least an order of magnitude lower than the Earth, and the airless Moon is even quieter still. These pristine low-vibration environments are ideal for searching for nuggets of "strange quark matter." Strange quark matter was postulated by Edward Witten [Phys. Rev. D30, 272, 1984] as the lowest possible energy state of matter. It would be made of up, down, and strange quarks, instead of protons and neutrons made only of up and down quarks. It would have nuclear densities, and hence be difficult to detect. Micron-sized nuggets would weigh in the ton range. As suggested by de Rujula and Glashow [Nature 312 (5996): 734, 1984], a massive strange quark nugget can generate a trail of seismic waves, as it traverses a celestial body. We discuss the mission concept for deploying a network of sensitive seismometers on Mars and on the Moon for such a search.

Evaluation of a modified pH-shift process to reduce 2-methylisoborneol and geosmin in spiked catfish and produce a consumer acceptable fried catfish nugget-like product.

Science.gov (United States)

Brown, T M; Cerruto-Noya, C A; Schrader, K K; Kleinholz, C W; DeWitt, C A Mireles

2012-10-01

Muddy and/or musty off-flavors in farmed-raised catfish occur as a result of the absorption of geosmin (GEO) and 2-methylisoborneol (MIB), compounds produced by algae. Previous research suggests the acid pH-shift method may be able to reduce off-flavors to produce a consumer acceptable product. The objective of this research was to evaluate application of the acid pH-shift method using a shaker sieve for protein recovery and to evaluate consumer acceptability of a resultant batter-coated fried nugget-like catfish product. Farm-raised catfish were either allowed to depurate (control) or treated with 1 ppb GEO or MIB. Fillets from each replicate were collected and ground and treated by the acid pH-shift process. Samples from all treatments and replicates were evaluated for residual GEO and MIB. In addition, batter-coated fried catfish samples were prepared for a consumer sensory evaluation. Results demonstrated that the pH-shift process decreased moisture, ash, and collagen content of catfish fillet tissue (P evaluated for removing off-flavors from catfish. Difficulties were encountered with regard to protein recovery using the sieve and suggestions are made to, perhaps, make the process more applicable for a sieve-based recovery step. The process as described reduced off-flavors, but only 2-fold suggesting the process would work best on catfish near or just over off-flavor thresholds. Results also indicated the pH-shift process could be used to improve texture of a fried catfish product designed to be similar to chicken nuggets. © 2012 Institute of Food Technologists®

The obtaining of iron acetate from processed iron comprising catalyst of ammonia synthesis

International Nuclear Information System (INIS)

Mansurov, M.M.; Lugovenko, A.N.; Mirzoeva, M.M.

1993-01-01

Present article is devoted to obtaining of iron acetate from processed iron comprising catalyst of ammonia synthesis. The method of synthesis of iron acetate from processed iron comprising catalyst of ammonia synthesis was elaborated. The structure of complex was determined.

Spatially varying cross-correlation coefficients in the presence of nugget effects

KAUST Repository

Kleiber, William; Genton, Marc G.

2012-01-01

We derive sufficient conditions for the cross-correlation coefficient of a multivariate spatial process to vary with location when the spatial model is augmented with nugget effects. The derived class is valid for any choice of covariance functions, and yields substantial flexibility between multiple processes. The key is to identify the cross-correlation coefficient matrix with a contraction matrix, which can be either diagonal, implying a parsimonious formulation, or a fully general contraction matrix, yielding greater flexibility but added model complexity. We illustrate the approach with a bivariate minimum and maximum temperature dataset in Colorado, allowing the two variables to be positively correlated at low elevations and nearly independent at high elevations, while still yielding a positive definite covariance matrix. © 2012 Biometrika Trust.

Spatially varying cross-correlation coefficients in the presence of nugget effects

KAUST Repository

Kleiber, William

2012-11-29

We derive sufficient conditions for the cross-correlation coefficient of a multivariate spatial process to vary with location when the spatial model is augmented with nugget effects. The derived class is valid for any choice of covariance functions, and yields substantial flexibility between multiple processes. The key is to identify the cross-correlation coefficient matrix with a contraction matrix, which can be either diagonal, implying a parsimonious formulation, or a fully general contraction matrix, yielding greater flexibility but added model complexity. We illustrate the approach with a bivariate minimum and maximum temperature dataset in Colorado, allowing the two variables to be positively correlated at low elevations and nearly independent at high elevations, while still yielding a positive definite covariance matrix. © 2012 Biometrika Trust.

Consumer attitudes and behaviours--key risk factors in an outbreak of Salmonella typhimurium phage type 12 infection sourced to chicken nuggets.

Science.gov (United States)

Kenny, B; Hall, R; Cameron, S

1999-04-01

To identify the source and intervention methods for an outbreak of Salmonella Typhimurium phage type 12 in South Australia. Ten cases of S. Typhimurium phage type (PT) 12 infection were notified in South Australia in a four-week period from 7 May 1998. Nine cases and 27 controls were included in a case control study to test the hypothesis that illness was associated with the consumption of chicken nuggets. A significant association between illness and the consumption of one brand of chicken nuggets was determined, odds ratio undefined (95% CI undefined; p = undefined). Nine of nine cases and one of 27 controls reported eating these chicken nuggets. S. Typhimurium PT 12 was isolated from an opened sample of this particular brand of nuggets which had been retrieved from the home of one case. The implicated nuggets were essentially a raw product which had been 'flash fried' in contrast with other brands which were fully cooked. The investigation highlighted issues of inadequate labelling and consumer responses to labelling information which affect food safety. A media release to highlight to the consumer the need to cook frozen food properly and a voluntary recall of the 'flash fried' product was instigated as a result of these conclusions. Further action is needed to eliminate the potential hazard that consumers will perceive and handle 'flash fried' nuggets as if they are a cooked chicken product.

Challenges facing the North American iron ore industry

Science.gov (United States)

Jorgenson, J.D.

2005-01-01

During the 20th century, the iron ore mining industries of Canada and the United States passed through several periods of transformation. The beginning of the 21st century has seen yet another period of transformation, with the economic failure of a number of steel companies, the acquisition of their facilities by more viable steelmakers, and the consolidation of control within the North American iron ore industry. Changes in Canadian and United States iron ore production and the market control structure involved are analysed. The consolidation of ownership, formation of foreign joint ventures within Nordi America, planned divestitures of upstream activities by steelmakers, and industry changes made to ensure availability of feedstocks will be reviewed. The ttaditional isolation of the Canadian and United States iron ore operations and their strong linkage to downstream steel production will be discussed in the context of a changing global economy. Management-labour conflicts that have taken place and agreements made during 2000 through 2004 will be discussed in the context of the economic environment leading up to these agreements. Cooperative agreements between competing Canadian and United States companies to resolve client needs in processing and blending will be examined. A joint industry-government project designed to use new technology to produce direct reduced iron nuggets of 96 - 98 per cent iron content using non-coking coals will also be assessed. Changes in iron ore transportation methods, ownership and infrastructure will be reviewed for both rail and inland waterway transport between Canadian and United States companies. A brief analysis of social and environmental issues relating to sustainable development of the Canadian-United States iron ore industry will be included.

Vitamin E Contents and Oxidative Stability of Red Palm Oils Blended Chicken Nuggets during Frozen Storage

International Nuclear Information System (INIS)

Nurkhuzaiah Kamaruzaman; Abdul Salam Babji; Wan Rosli Wan Ismail; Peng, F.S.

2015-01-01

Red Palm Oil (RPO) has a high oxidative stability and contains high levels of natural antioxidants, such as vitamin E and carotenoids. In this study, Vitamin E contents and lipid oxidation of chicken nuggets blended with red palm oil consist of NVRO, NVRO-100 and NVRO-50 were compared against the control chicken fat treatment, each containing 10 % fat. Vitamin E contents, thiobarbituric acid (TBA) values and peroxide values (PV) for all samples were measured throughout 4 months of storage at -18 degree Celsius. All the vitamin E homologues were decreased. α-tocopherol and α-tocotrienol decreased faster meanwhile δ-tocopherol decreased slower than other homologues. Besides that, Vitamin E content in NVRO and NVRO-100 was significantly decreased (p<0.05) from 767.15 to 482.14 μg/ g and 842.73 to 672.36 μg/ g respectively. TBA and PV values for all samples chicken nuggets increased throughout 3 months of frozen storage but started to decrease thereafter. However, chicken nuggets formulated with NVRO, NVRO-100 and NVRO-50 significantly reduced (p<0.05) TBA and PV values compared with chicken fat treatments. This study showed that frozen storage influence vitamin E stability and the potential of utilization of red palm oils in improving nutritional quality and reducing lipid oxidation of chicken nugget. (author)

Quality of Low Fat Chicken Nuggets: Effect of Sodium Chloride Replacement and Added Chickpea ( L. Hull Flour

Directory of Open Access Journals (Sweden)

Arun K. Verma

2012-02-01

Full Text Available While attempting to develop low salt, low fat and high fibre chicken nuggets, the effect of partial (40% common salt substitution and incorporation of chickpea hull flour (CHF at three different levels viz., 5, 7.5 and 10% (Treatments in pre-standardized low fat chicken nuggets (Control were observed. Common salt replacement with salt substitute blend led to a significant decrease in pH, emulsion stability, moisture, ash, hardness, cohesiveness, gumminess and chewiness values while incorporation of CHF in low salt, low fat products resulted in decreased emulsion stability, cooking yield, moisture, protein, ash, color values, however dietary fibre and textural properties were increased (p<0.01. Lipid profile revealed a decrease in total cholesterol and glycolipid contents with the incorporation of CHF (p<0.01. All the sensory attributes except appearance and flavor, remained unaffected with salt replacement, while addition of CHF resulted in lower sensory scores (p<0.01. Among low salt, low fat chicken nuggets with CHF, incorporation CHF at 5% level was found optimum having sensory ratings close to very good. Thus most acceptable low salt, low fat and high fibre chicken nuggets could be developed by a salt replacement blend and addition of 5% CHF.

ARSENIC REMOVAL BY IRON REMOVAL PROCESSES

Science.gov (United States)

Presentation will discuss the removal of arsenic from drinking water using iron removal processes that include oxidation/filtration and the manganese greensand processes. Presentation includes results of U.S. EPA field studies conducted in Michigan and Ohio on existing iron remo...

Hydrogen Plasma Processing of Iron Ore

Science.gov (United States)

Sabat, Kali Charan; Murphy, Anthony B.

2017-06-01

Iron is currently produced by carbothermic reduction of oxide ores. This is a multiple-stage process that requires large-scale equipment and high capital investment, and produces large amounts of CO2. An alternative to carbothermic reduction is reduction using a hydrogen plasma, which comprises vibrationally excited molecular, atomic, and ionic states of hydrogen, all of which can reduce iron oxides, even at low temperatures. Besides the thermodynamic and kinetic advantages of a hydrogen plasma, the byproduct of the reaction is water, which does not pose any environmental problems. A review of the theory and practice of iron ore reduction using a hydrogen plasma is presented. The thermodynamic and kinetic aspects are considered, with molecular, atomic and ionic hydrogen considered separately. The importance of vibrationally excited hydrogen molecules in overcoming the activation energy barriers, and in transferring energy to the iron oxide, is emphasized. Both thermal and nonthermal plasmas are considered. The thermophysical properties of hydrogen and argon-hydrogen plasmas are discussed, and their influence on the constriction and flow in the of arc plasmas is considered. The published R&D on hydrogen plasma reduction of iron oxide is reviewed, with both the reduction of molten iron ore and in-flight reduction of iron ore particles being considered. Finally, the technical and economic feasibility of the process are discussed. It is shown that hydrogen plasma processing requires less energy than carbothermic reduction, mainly because pelletization, sintering, and cokemaking are not required. Moreover, the formation of the greenhouse gas CO2 as a byproduct is avoided. In-flight reduction has the potential for a throughput at least equivalent to the blast furnace process. It is concluded that hydrogen plasma reduction of iron ore is a potentially attractive alternative to standard methods.

Compositional studies on Transylvanian gold nuggets: Advantages and limitations of PIXE-PIGE analysis

International Nuclear Information System (INIS)

Bugoi, Roxana; Cojocaru, Viorel; Constantinescu, Bogdan; Calligaro, Thomas; Pichon, Laurent; Roehrs, Stefan; Salomon, Joseph

2008-01-01

Minute fragments from nine gold nuggets from Transylvania - two belonging to placer deposits and seven to primary deposits - were analyzed by PIXE and PIGE at the AGLAE tandem accelerator of the Centre de Recherche et de Restauration des Musees de France (C2RMF) with a 3 MeV proton beam extracted into air. This study was triggered by some archaeological provenance issues for which the elemental characterization of the Transylvanian gold source, exploited from the Antiquity, was required. All analyzed Transylvanian gold nuggets are characterized by a consistently high amount of Ag (18% on average). Au and Ag add up to roughly 99%, the other elements - Cu, Fe, Te, Pb - being detected only at a trace level. The obtained results are in good agreement with the previous analyses of Transylvanian gold

The North American iron ore industry: a decade into the 21st century

Science.gov (United States)

Jorgenson, John D.; Perez, A. A

2011-01-01

During the 20th century, the iron ore mining industries of Canada and the United States passed through periods of transformation. The beginning of the 21st century has seen another period of transformation, with the failure of a number of steel companies and with consolidation of control within the North American iron ore industry. Canadian and United States iron ore production and the market control structure involved are changing rapidly. Consolidation of ownership, formation of foreign joint ventures, divestitures of upstream activities by steelmakers, and industry changes to ensure availability of feedstocks all played a role in recent developments in the North American iron ore industry. Canadian and U.S. iron ore operations and their strong linkage to downstream production, although isolated, must also be considered within the context of the changing global economy. Projects using new technology to produce direct reduced iron nuggets of 96-98% iron content and other projects designed to produce steel at minesites may once again change the face of the iron ore industry. Social and environmental issues related to sustainable development have had a significant effect on the North American iron ore industry.

Use of ionizing radiation in elaborated products of chicken (nuggets) for control of Escherichia coli O157:H7 and salmonella enteriditis

International Nuclear Information System (INIS)

Kaempffer Ramirez, Daniela Andrea

2005-01-01

The application of ionizing energy in Chicken's Nugget of a trade mark, was studied by the University Santo Tomas in conjunction with the Chilean Nuclear Energy Commission in order to eliminate pathogens such as Escherichia coli and Salmonella enteritidis, in addition to 9 nuggets without sterilize select for RAM. Furthermore, to search the organoleptic characteristic and to Almost Chemist Analysis by means of determined doses. A total of 144 frozen Nuggets (-18 o C) were analyzed and divided into two equal groups for artificially contamination. Each Nuggets - weighting 25 g - was put into sealed polyetilene bags. The two sample groups were sterilized with an irradiation doses of 25 kGy, then inoculated with Escherichia coli O157:H7 strain ATCC 25922 ISP (Instituto de Salud Publica) and Salmonella enteritidis strain ATCC 1833-99 ISP. The samples of each group were treated with gamma irradiation (Co 60 ), with doses of 0, 0.3,0.6 and 0.9 kGy analyzing the bacteria counts after 24 hours, 30 nd 60 days post radiation. D 10 values mid-point were found with a 0,242 kGy for the Escherichia coli and 0,295 kGy for the Salmonella enteritidis. The storage time did not time exert any influence on the D 10 values. The storage time don't showed meaningful differences between the days 1, 30 and 60, in the results obtained in the mid-point D 10 value. The sensory analysis of Nugget was done by means of a trained sensorial panel who evaluated samples with 0; 0.75 and 1,5 kGy. Each person tasted the complete sample (25 g.) and evaluated; appearance, color, odor, , bitterness, texture, flavor and acceptability. Statistically, none attribute showed significant differences (p≤0.05) between the radiated samples and the control group, concluding that the level of the Nugget acceptability was qualified as very good. The Almost Chemist Analysis of Nugget was done to two groups: A control Group (without to irradiate) and a irradiated group with 1.5 kGy. It's evaluated Proteins, Fats

Deactivation of iron oxide used in the steam-iron process to produce hydrogen

NARCIS (Netherlands)

Bleeker, M.F.; Veringa, H.J.; Kersten, Sascha R.A.

2009-01-01

In the steam-iron process pure hydrogen can be produced from any hydrocarbon feedstock by using a redox cycle of iron oxide. One of the main problems connected to the use of the iron oxide is the inherent structural changes that take place during oxygen loading and unloading leading to severe

Atmospheric processing of iron carried by mineral dust

Directory of Open Access Journals (Sweden)

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.

Representative process sampling - in practice

DEFF Research Database (Denmark)

Esbensen, Kim; Friis-Pedersen, Hans Henrik; Julius, Lars Petersen

2007-01-01

Didactic data sets representing a range of real-world processes are used to illustrate "how to do" representative process sampling and process characterisation. The selected process data lead to diverse variogram expressions with different systematics (no range vs. important ranges; trends and....../or periodicity; different nugget effects and process variations ranging from less than one lag to full variogram lag). Variogram data analysis leads to a fundamental decomposition into 0-D sampling vs. 1-D process variances, based on the three principal variogram parameters: range, sill and nugget effect...

Using the Moon As A Low-Noise Seismic Detector For Strange Quark Nuggets

Science.gov (United States)

Banerdt, W. Bruce; Chui, Talso; Griggs, Cornelius E.; Herrin, Eugene T.; Nakamura, Yosio; Paik, Ho Jung; Penanen, Konstantin; Rosenbaum, Doris; Teplitz, Vigdor L.; Young, Joseph

2006-01-01

Strange quark matter made of up, down and strange quarks has been postulated by Witten [1]. Strange quark matter would be nearly charge neutral and would have density of nuclear matter (10(exp 14) gm/cu cm). Witten also suggested that nuggets of strange quark matter, or strange quark nuggets (SQNs), could have formed shortly after the Big Bang, and that they would be viable candidates for cold dark matter. As suggested by de Rujula and Glashow [2], an SQN may pass through a celestial body releasing detectable seismic energy along a straight line. The Moon, being much quieter seismically than the Earth, would be a favorable place to search for such events. We review previous searches for SQNs to illustrate the parameter space explored by using the Moon as a low-noise detector of SQNs. We also discuss possible detection schemes using a single seismometer, and using an International Lunar Seismic Network.

TaqMan probe real-time polymerase chain reaction assay for the quantification of canine DNA in chicken nugget.

Science.gov (United States)

Rahman, Md Mahfujur; Hamid, Sharifah Bee Abd; Basirun, Wan Jefrey; Bhassu, Subha; Rashid, Nur Raifana Abdul; Mustafa, Shuhaimi; Mohd Desa, Mohd Nasir; Ali, Md Eaqub

2016-01-01

This paper describes a short-amplicon-based TaqMan probe quantitative real-time PCR (qPCR) assay for the quantitative detection of canine meat in chicken nuggets, which are very popular across the world, including Malaysia. The assay targeted a 100-bp fragment of canine cytb gene using a canine-specific primer and TaqMan probe. Specificity against 10 different animals and plants species demonstrated threshold cycles (Ct) of 16.13 ± 0.12 to 16.25 ± 0.23 for canine DNA and negative results for the others in a 40-cycle reaction. The assay was tested for the quantification of up to 0.01% canine meat in deliberately spiked chicken nuggets with 99.7% PCR efficiency and 0.995 correlation coefficient. The analysis of the actual and qPCR predicted values showed a high recovery rate (from 87% ± 28% to 112% ± 19%) with a linear regression close to unity (R(2) = 0.999). Finally, samples of three halal-branded commercial chicken nuggets collected from different Malaysian outlets were screened for canine meat, but no contamination was demonstrated.

Effective Processing of the Iron Ores

Science.gov (United States)

Kuskov, Vadim; Kuskova, Yana; Udovitsky, Vladimir

2017-11-01

Effective technology for a complex wasteless processing of the iron ores has been designed and includes three main components (plats): comminution plant, briquette plant, pigment plant. The comminution is done per energy effective technology. Using of briquetting for ores clotting enables the costs cut and brings to a higher level of environmental safety of the process. Briquette formation can be done as a regular pressing, as an extrusion. Developed technology allows to produce high quality competitively products for metallurgy industry and red iron oxide pigments. The whole production line impacts the environment in a minimal manner.

Effective Processing of the Iron Ores

Directory of Open Access Journals (Sweden)

Kuskov Vadim

2017-01-01

Full Text Available Effective technology for a complex wasteless processing of the iron ores has been designed and includes three main components (plats: comminution plant, briquette plant, pigment plant. The comminution is done per energy effective technology. Using of briquetting for ores clotting enables the costs cut and brings to a higher level of environmental safety of the process. Briquette formation can be done as a regular pressing, as an extrusion. Developed technology allows to produce high quality competitively products for metallurgy industry and red iron oxide pigments. The whole production line impacts the environment in a minimal manner.

Influence of tool pin profile on microstructure and corrosion behaviour of AA2219 Al–Cu alloy friction stir weld nuggets

Directory of Open Access Journals (Sweden)

Ch. Venkata Rao

2015-09-01

Full Text Available To overcome the problems of fusion welding of aluminium alloys, the friction stir welding (FSW is recognized as an alternative joining method to improve the mechanical and corrosion properties. Tool profile is one of the important variables which affect the performance of the FS weld. In the present work, the effect of tool profile on the weld nugget microstructure and pitting corrosion of AA2219 aluminium–copper alloy was studied. FSW of AA2219 alloy was carried out using five profiles, namely conical, square, triangle, pentagon and hexagon. The temperature measurements were made in the region adjacent to the rotating pin. It was observed that the peak temperature is more in hexagonal tool pin compared to the welds produced with other tool pin profiles. It is observed that the extensive deformation experienced at the nugget zone and the evolved microstructure strongly influences the hardness and corrosion properties of the joint during FSW. It was found that the microstructure changes like grain size, misorientation and precipitate dissolution during FSW influence the hardness and corrosion behaviour. Pitting corrosion resistance of friction stir welds of AA2219 was found to be better for hexagon profile tool compared to other profiles, which was attributed to material flow and strengthening precipitate morphology in nugget zone. Higher amount of heat generation in FS welds made with hexagonal profile tool may be the reason for greater dissolution of strengthening precipitates in nugget zone.

Bernie's Odyssey: Denver Nuggets' General Manager Bernie Bickerstaff's Basketball Roots in Harlan County, Ky.

Science.gov (United States)

Nelson, Glenn

1992-01-01

Bernie Bickerstaff discusses how growing up as an African-American athlete in rural Kentucky prepared him to become the general manager of the Denver Nuggets. Triumphing over the area's racial segregation, poverty, and mining perils gave him a sense of strength that enabled him to overcome barriers in advancing his career. (LP)

Evaluation of the nugget diameter in spot welded joints between two steel sheets by means of a potential drop technique

International Nuclear Information System (INIS)

Tohmyoh, Hironori; Ikarashi, Hidetomo; Matsui, Yoichi; Hasegawa, Yuta; Obara, Satoshi

2015-01-01

A potential drop technique which utilizes the electrical circuit used in resistance spot welding is reported. Spot welded samples comprising two steel sheets were inserted between the two Cu electrodes and a constant direct current was supplied between the electrodes. The potential drop between two points, one on each electrode, was determined by analysis for various values of nugget diameter and various values of the contact resistance between the Cu electrodes and the steel sheet sample. The nugget diameter of the spot welded joint could be quantitatively evaluated from the measured potential drop and the equation obtained from the analysis. (paper)

Evaluation of the nugget diameter in spot welded joints between two steel sheets by means of a potential drop technique

Science.gov (United States)

Tohmyoh, Hironori; Ikarashi, Hidetomo; Matsui, Yoichi; Hasegawa, Yuta; Obara, Satoshi

2015-08-01

A potential drop technique which utilizes the electrical circuit used in resistance spot welding is reported. Spot welded samples comprising two steel sheets were inserted between the two Cu electrodes and a constant direct current was supplied between the electrodes. The potential drop between two points, one on each electrode, was determined by analysis for various values of nugget diameter and various values of the contact resistance between the Cu electrodes and the steel sheet sample. The nugget diameter of the spot welded joint could be quantitatively evaluated from the measured potential drop and the equation obtained from the analysis.

Data Nuggets: Bringing Real Data into the Classroom to Unearth Students' Quantitative & Inquiry Skills

Science.gov (United States)

Schultheis, Elizabeth H.; Kjelvik, Melissa K.

2015-01-01

Current educational reform calls for increased integration between science and mathematics to overcome the shortcomings in students' quantitative skills. Data Nuggets (free online resource, http://datanuggets.org) are worksheets that bring data into the classroom, repeatedly guiding students through the scientific method and making claims…

Very High Cycle Fatigue Crack Initiation Mechanism in Nugget Zone of AA 7075 Friction Stir Welded Joint

Directory of Open Access Journals (Sweden)

Chao He

2017-01-01

Full Text Available Very high cycle fatigue behavior of nugget zone in AA 7075 friction stir welded joint was experimentally investigated using ultrasonic fatigue testing system (20 kHz to clarify the crack initiation mechanism. It was found that the fatigue strength of nugget zone decreased continuously even beyond 107 cycles with no traditional fatigue limits. Fatigue cracks initiated from the welding defects located at the bottom side of the friction stir weld. Moreover, a special semicircular zone could be characterized around the crack initiation site, of which the stress intensity factor approximately equaled the threshold of fatigue crack propagation rate. Finally, a simplified model was proposed to estimate the fatigue life by correlating the welding defect size and applied stress. The predicted results are in good agreement with the experimental results.

Isotropic radio background from quark nugget dark matter

Energy Technology Data Exchange (ETDEWEB)

Lawson, Kyle; Zhitnitsky, Ariel R., E-mail: arz@physics.ubc.ca

2013-07-09

Recent measurements by the ARCADE2 experiment unambiguously show an excess in the isotropic radio background at frequencies below the GHz scale. We argue that this excess may be a natural consequence of the interaction of visible and dark matter in the early universe if the dark matter consists of heavy nuggets of quark matter. Explanation of the observed radio band excess requires the introduction of no new parameters, rather we exploit the same dark matter model and identical normalization parameters to those previously used to explain other excesses of diffuse emission from the centre of our galaxy. These previously observed excesses include the WMAP Haze of GHz radiation, keV X-ray emission and MeV gamma-ray radiation.

Isotropic radio background from quark nugget dark matter

International Nuclear Information System (INIS)

Lawson, Kyle; Zhitnitsky, Ariel R.

2013-01-01

Recent measurements by the ARCADE2 experiment unambiguously show an excess in the isotropic radio background at frequencies below the GHz scale. We argue that this excess may be a natural consequence of the interaction of visible and dark matter in the early universe if the dark matter consists of heavy nuggets of quark matter. Explanation of the observed radio band excess requires the introduction of no new parameters, rather we exploit the same dark matter model and identical normalization parameters to those previously used to explain other excesses of diffuse emission from the centre of our galaxy. These previously observed excesses include the WMAP Haze of GHz radiation, keV X-ray emission and MeV gamma-ray radiation

Application of complex inoculants in improving the process-ability of grey cast iron for cylinder blocks

Directory of Open Access Journals (Sweden)

LIU Wei-ming

2006-05-01

Full Text Available Effect of several complex inoculants on mechanical properties, process-ability and sensibility of grey cast iron used in cylinder block were investigated. The experimental results showed that the grey cast iron treated with 60%FeSi75+40%RE complex inoculants has tensile strength consistently at about 295 MPa along with good hardness and improved metallurgy quality. While the grey cast iron inoculated with 20%FeSi75+80%Sr compound inoculants has the best process-ability, the lowest cross-section sensibility and the least microhardness difference. The wear amount of the drill increases correspondingly with the increase of the microhardness difference of matrix structure, indicating the great effect of homogeneousness of matrix structure in the grey cast iron on the machinability of the grey cast iron.

Wastewater engineering applications of BioIronTech process based on the biogeochemical cycle of iron bioreduction and (biooxidation

Directory of Open Access Journals (Sweden)

Volodymyr Ivanov

2014-12-01

Full Text Available Bioreduction of Fe(III and biooxidation of Fe(II can be used in wastewater engineering as an innovative biotechnology BioIronTech, which is protected for commercial applications by US patent 7393452 and Singapore patent 106658 “Compositions and methods for the treatment of wastewater and other waste”. The BioIronTech process comprises the following steps: 1 anoxic bacterial reduction of Fe(III, for example in iron ore powder; 2 surface renovation of iron ore particles due to the formation of dissolved Fe2+ ions; 3 precipitation of insoluble ferrous salts of inorganic anions (phosphate or organic anions (phenols and organic acids; 4 (biooxidation of ferrous compunds with the formation of negatively, positively, or neutrally charged ferric hydroxides, which are good adsorbents of many pollutants; 5 disposal or thermal regeration of ferric (hydroxide. Different organic substances can be used as electron donors in bioreduction of Fe(III. Ferrous ions and fresh ferrous or ferric hydroxides that are produced after iron bioreduction and (biooxidation adsorb and precipitate diferent negatively charged molecules, for example chlorinated compounds of sucralose production wastewater or other halogenated organics, as well as phenols, organic acids, phosphate, and sulphide. Reject water (return liquor from the stage of sewage sludge dewatering on municipal wastewater treatment plants represents from 10 to 50% of phosphorus load when being recycled to the aeration tank. BioIronTech process can remove/recover more than 90% of phosphorous from this reject water thus replacing the conventional process of phosphate precipitation by ferric/ferrous salts, which are 20–100 times more expensive than iron ore, which is used in BioIronTech process. BioIronTech process can remarkably improve the aerobic and anaerobic treatments of municipal and industrial wastewaters, especially anaerobic digestion of lipid- and sulphate-containing food-processing wastewater. It

Iron-oxidation processes in an electroflocculation (electrocoagulation) cell

Energy Technology Data Exchange (ETDEWEB)

Sasson, Moshe Ben, E-mail: mosheinspain@hotmail.com [Department of Soil and Water Sciences, Robert H. Smith Faculty of Agriculture, Food and Environment, Hebrew University of Jerusalem, Rehovot 76100 (Israel); Calmano, Wolfgang [Institute of Environmental Technology and Energy Economics, Technical University of Hamburg-Harburg, 21073 Hamburg (Germany); Adin, Avner [Department of Soil and Water Sciences, Robert H. Smith Faculty of Agriculture, Food and Environment, Hebrew University of Jerusalem, Rehovot 76100 (Israel)

2009-11-15

The processes of iron oxidation in an electroflocculation cell were investigated for a pH range of 5-9 and electric currents of 0.05-0.4 A (equivalent current densities of 8.6-69 A/m{sup 2}). At all pH values and electric currents investigated, it was demonstrated and proven that for all practical purposes, the form of iron that dissolves from the anode is Fe{sup 2+} (ferrous). The difference between the amount of theoretical dissolution as calculated by Faraday's law and the amount of observed dissolved iron ions may indicate two phenomena in electrochemical cells. The first is possible dissolution of the anode even without the operation of an electric current; this led to higher theoretical dissolution rates at lower pH. The second is the participation of some of the electrons of the electric current in reactions other than anode dissolution which led to lower theoretical dissolution rates at higher pH. Those other reactions did not lead to an increase in the local oxidation saturation level near the anode and did not affect iron-oxidation rates in the electroflocculation processes. The oxidation rates of the dissolved Fe{sup 2+} (ferrous) to Fe{sup 3+} (ferric) ions in electroflocculation processes were strongly dependent on the pH and were similar to the known oxidation rates of iron in non-electrochemical cells.

Iron-oxidation processes in an electroflocculation (electrocoagulation) cell

International Nuclear Information System (INIS)

Sasson, Moshe Ben; Calmano, Wolfgang; Adin, Avner

2009-01-01

The processes of iron oxidation in an electroflocculation cell were investigated for a pH range of 5-9 and electric currents of 0.05-0.4 A (equivalent current densities of 8.6-69 A/m 2 ). At all pH values and electric currents investigated, it was demonstrated and proven that for all practical purposes, the form of iron that dissolves from the anode is Fe 2+ (ferrous). The difference between the amount of theoretical dissolution as calculated by Faraday's law and the amount of observed dissolved iron ions may indicate two phenomena in electrochemical cells. The first is possible dissolution of the anode even without the operation of an electric current; this led to higher theoretical dissolution rates at lower pH. The second is the participation of some of the electrons of the electric current in reactions other than anode dissolution which led to lower theoretical dissolution rates at higher pH. Those other reactions did not lead to an increase in the local oxidation saturation level near the anode and did not affect iron-oxidation rates in the electroflocculation processes. The oxidation rates of the dissolved Fe 2+ (ferrous) to Fe 3+ (ferric) ions in electroflocculation processes were strongly dependent on the pH and were similar to the known oxidation rates of iron in non-electrochemical cells.

Effect of different binders on the physico-chemical, textural, histological, and sensory qualities of retort pouched buffalo meat nuggets.

Science.gov (United States)

Devadason, I Prince; Anjaneyulu, A S R; Babji, Y

2010-01-01

The functional properties of 4 binders, namely corn starch, wheat semolina, wheat flour, and tapioca starches, were evaluated to improve the quality of buffalo meat nuggets processed in retort pouches at F(0) 12.13. Incorporation of corn starch in buffalo meat nuggets produced more stable emulsion than other binders used. Product yield, drip loss, and pH did not vary significantly between the products with different binders. Shear force value was significantly higher for product with corn starch (0.42 +/- 0.0 Kg/cm(3)) followed by refined wheat flour (0.36 +/- 0.010 Kg/cm(3)), tapioca starch (0.32 +/- 0.010 Kg/cm(3)), and wheat semolina (0.32 +/- 0.010 Kg/cm(3)). Type of binder used had no significant effect on frying loss, moisture, and protein content of the product. However, fat content was higher in products with corn starch when compared to products with other binders. Texture profile indicated that products made with corn starch (22.17 +/- 2.55 N) and refined wheat flour (21.50 +/- 0.75 N) contributed firmer texture to the product. Corn starch contributed greater chewiness (83.8 +/- 12.51) to the products resulting in higher sensory scores for texture and overall acceptability. Products containing corn starch showed higher sensory scores for all attributes in comparison to products with other binders. Panelists preferred products containing different binders in the order of corn starch (7.23 +/- 0.09) > refined wheat flour (6.48 +/- 0.13) > tapioca starch (6.45 +/- 0.14) > wheat semolina (6.35 +/- 0.13) based on sensory scores. Histological studies indicated that products with corn starch showed dense protein matrix, uniform fat globules, and less number of vacuoles when compared to products made with other binders. The results indicated that corn flour is the better cereal binder for developing buffalo meat nuggets when compared to all other binders based on physico-chemical and sensory attributes.

Quark nugget dark matter: Comparison with radio observations of nearby galaxies

Energy Technology Data Exchange (ETDEWEB)

Lawson, K., E-mail: klawson@phas.ubc.ca; Zhitnitsky, A.R.

2016-06-10

It has been recently claimed that radio observations of nearby spiral galaxies essentially rule out a dark matter source for the galactic haze [1]. Here we consider the low energy thermal emission from a quark nugget dark matter model in the context of microwave emission from the galactic centre and radio observations of nearby Milky Way like galaxies. We demonstrate that observed emission levels do not strongly constrain this specific dark matter candidate across a broad range of the allowed parameter space in drastic contrast with conventional dark matter models based on the WIMP paradigm.

Micrometer- and nanometer-sized platinum group nuggets in micrometeorites from deep-sea sediments of the Indian Ocean

Digital Repository Service at National Institute of Oceanography (India)

Rudraswami, N.G.; Parashar, K.; ShyamPrasad, M.

We examined 378 micrometeorites collected from deep-sea sediments of the Indian Ocean of which 175, 180, and 23 are I-type, S-type, and G-type, respectively. Of the 175 I-type spherules, 13 contained platinum group element nuggets (PGNs...

Fusion welding process

Science.gov (United States)

Thomas, Kenneth C.; Jones, Eric D.; McBride, Marvin A.

1983-01-01

A process for the fusion welding of nickel alloy steel members wherein a ferrite containing pellet is inserted into a cavity in one member and melted by a welding torch. The resulting weld nugget, a fusion of the nickel containing alloy from the members to be welded and the pellet, has a composition which is sufficiently low in nickel content such that ferrite phases occur within the weld nugget, resulting in improved weld properties. The steel alloys encompassed also include alloys containing carbon and manganese, considered nickel equivalents.

Influence of reaction chamber shape on cast-iron spheroidization process in-mold

Directory of Open Access Journals (Sweden)

S. Pietrowski

2010-01-01

Full Text Available This paper presents a results concerning the influence of reaction chamber shape on cast – iron spheroidization process in form. The volume of the tested reaction chambers was about 118000mm3. Reaction chambers in the shape of: rectangular, cylinder and spherical cap were examined. It has been shown that the best graphite spheroidizing process was provided by spherical cap chamber shape. The reaction of cast – iron with magnesium in reaction chamber depends on the flow of cast – iron in the chamber. In rectangular and cylinder shape chambers proceed the impact of diphase stream on flat bottom wall. It causes the creation on its surface film, called: cast – iron “film”, where single grains of magnesium master alloy exist. The largest part of master alloy is drifted by liquid cast – iron to the top and only there graphite spheroidization process proceed. In the spherical cap shape reaction chamber, as a result of rotation movement of liquid cast – iron throughout its volume, graphite spheroidization process proceed. Apart from the reaction chamber shape, applying of mixing chamber ensure full cast – iron spheroidization process.

Iron crystallization in a fluidized-bed Fenton process.

Science.gov (United States)

Boonrattanakij, Nonglak; Lu, Ming-Chun; Anotai, Jin

2011-05-01

The mechanisms of iron precipitation and crystallization in a fluidized-bed reactor were investigated. Within the typical Fenton's reagent dosage and pH range, ferric ions as a product from ferrous ion oxidation would be supersaturated and would subsequently precipitate out in the form of ferric hydroxide after the initiation of the Fenton reaction. These precipitates would simultaneously crystallize onto solid particles in a fluidized-bed Fenton reactor if the precipitation proceeded toward heterogeneous nucleation. The heterogeneous crystallization rate was controlled by the fluidized material type and the aging/ripening period of the crystallites. Iron crystallization onto the construction sand was faster than onto SiO(2), although the iron removal efficiencies at 180 min, which was principally controlled by iron hydroxide solubility, were comparable. To achieve a high iron removal rate, fluidized materials have to be present at the beginning of the Fenton reaction. Organic intermediates that can form ferro-complexes, particularly volatile fatty acids, can significantly increase ferric ion solubility, hence reducing the crystallization performance. Therefore, the fluidized-bed Fenton process will achieve exceptional performance with respect to both organic pollutant removal and iron removal if it is operated with the goal of complete mineralization. Crystallized iron on the fluidized media could slightly retard the successive crystallization rate; thus, it is necessary to continuously replace a portion of the iron-coated bed with fresh media to maintain iron removal performance. The iron-coated construction sand also had a catalytic property, though was less than those of commercial goethite. Copyright © 2011 Elsevier Ltd. All rights reserved.

SOFTWARE FOR IMAGE PROCESSING OF IRON-CARBONACEOUS ALLOY MICROSTRUCTURES

Directory of Open Access Journals (Sweden)

A. N. Chichko

2011-01-01

Full Text Available The paper proposes a mathematical apparatus for image processing of a cast-iron microstructure of a pearlite class that has casually distributed graphite inclusions in the structure the software has been developed and it allows to determine statistical functions concerning distribution of graphite inclusion characteristics according to areas, perimeters and distances between inclusions. The paper shows that computer processing of gray pig-iron microstructure image makes it possible to classify microstructures on the basis of statistical distribution of a graphite phase which are considered as indiscernible while applying conventional metallographic methods and it has practical significance for investigation of the interrelations – «workability – cast iron microstructure».

Treatment and Recycling of the Process Water in Iron Ore Flotation of Yuanjiacun Iron Mine

Directory of Open Access Journals (Sweden)

Wen-li Jiang

2017-01-01

Full Text Available Coagulating sedimentation and oxidation treatment of process water in iron ore flotation of Yuanjiacun iron mine had been studied. The process water of this mine carried residual polyacrylamide (PAM, poly(diallyldimethylammonium chloride (PDADMAC, and Ca2+ from the flotation and caused decrease of the iron flotation recovery or grade of the concentrate. The studies on high-intensity magnetic separation (HIMS tailings for coagulating sedimentation showed that the settling performance of coagulant (named CYH was better than that of PDADMAC. The analyses of FTIR spectra and zeta potential demonstrated that CYH is adsorbed mainly through electrostatic attraction onto HIMS tailings. Sodium hypochlorite was adopted to oxidize the residual organics in tailings wastewater. When sodium hypochlorite is at the dosage of 1.0 g/L, reaction temperature is of 20°C, and reaction time is of 30 minutes, the removal rates of PAM, COD, and Ca2+ were 90.48%, 83.97%, and 85.00%, respectively. Bench-scale flotation studies on the treated tailings wastewater indicated that the iron recovery and grade of concentrate were close to those of freshwater.

Development and evaluation of chicken nuggets with partial replacement of meat and fat by pea fibre

Directory of Open Access Journals (Sweden)

Yana Jorge POLIZER

2015-03-01

Full Text Available The aim of this study was to develop and evaluate a chicken nugget formulation with partial substitution of the meat or fat by pea fibre. Three formulations were developed: Control (C – commercial formulation, Fibre Less Meat (FLM – reduction of 10% of meat and addition of 2% of pea fibre and Fibre Less Fat (FLF – reduction of 10% of fat and addition of 2% pea fibre. The products were characterized for their pH value, instrumental colour, texture, cooking loss (frying, proximate composition, and sensory properties (acceptance test. The control treatment presented lower (p0.05 amongst the treatments. The texture analysis showed no significant differences amongst the treatments for elasticity and cohesiveness, although the FLF batch was firmer than the others (p0.05 amongst the three treatments for aroma, texture, flavour or overall acceptability. One can conclude that it is possible to partially replace meat and fat by pea fibre in chicken nuggets, without compromising most of the physicochemical characteristics and without altering the sensory acceptance.

Solidification, processing and properties of ductile cast iron

DEFF Research Database (Denmark)

Tiedje, Niels Skat

2010-01-01

Ductile cast iron has been an important engineering material in the past 50 years. In that time, it has evolved from a complicated material that required the foundry metallurgist's highest skill and strict process control to being a commonly used material that can easily be produced with modern...... of the latest years of research indicate that ductile cast iron in the future will become a highly engineered material in which strict control of a range of alloy elements combined with intelligent design and highly advanced processing allows us to target properties to specific applications to a much higher...... degree than we have seen previously. It is the aim of the present paper to present ductile iron as a modern engineering material and present the many different possibilities that the material hides. Focus will be on the latest research in solidification and melt treatment. But for completeness...

Microstructure feature of friction stir butt-welded ferritic ductile iron

International Nuclear Information System (INIS)

Chang, Hung-Tu; Wang, Chaur-Jeng; Cheng, Chin-Pao

2014-01-01

Highlights: • Defect-free ferritic ductile iron joints is fabricated by FSW. • The welding nugget is composed of graphite, martensite, and recrystallized ferrite. • The graphite displays a striped pattern in the surface and advancing side. • The ferritic matrix transforms into martensite structure during welding. • High degree of plastic deformation is found on the advancing side. - Abstract: This study conducted friction stir welding (FSW) by using the butt welding process to join ferritic ductile iron plates and investigated the variations of microsturcture in the joined region formed after welding. No defects appeared in the resulting experimental weld, which was formed using a 3-mm thick ductile iron plate and tungsten carbide alloy stir rod to conduct FSW at a rotational speed of 982 rpm and traveling speed of 72 mm/min. The welding region was composed of deformed graphite, martensite phase, and dynamically recrystallized ferrite structures. In the surface region and on the advancing side (AS), the graphite displayed a striped configuration and the ferritic matrix transformed into martensite. On the retreating side (RS), the graphite surrounded by martensite remained as individual granules and the matrix primarily comprised dynamically recrystallized ferrite. After welding, diffusion increased the carbon content of the austenite around the deformed graphite nodules, which transformed into martensite during the subsequent cooling process. A micro Vickers hardness test showed that the maximum hardness value of the martensite structures in the weld was approximately 800 HV. An analysis using an electron probe X-ray microanalyzer (EPMA) indicated that its carbon content was approximately 0.7–1.4%. The peak temperature on the RS, 8 mm from the center of the weld, measured 630 °C by the thermocouple. Overall, increased severity of plastic deformation and process temperature near the upper stir zone (SZ) resulted in distinct phase transformation

Biological removal of iron and manganese in rapid sand filters - Process understanding of iron and manganese removal

DEFF Research Database (Denmark)

Lin, Katie

to precipitation and corrosion. Manganese and iron can either be removed physico-chemically or biologically or combined. The physico-chemical oxidation and precipitation of manganese can theoretically be achieved by aeration, but this process is slow unless pH is raised far above neutral, making the removal...... of manganese by simple aeration and precipitation under normal drinking water treatment conditions insignificant. Manganese may also be oxidized autocatalytically. Iron is usually easier to remove. First, iron is rapidly chemically oxidized by oxygen at neutral pH followed by precipitation and filtration......-filter, where iron is removed. Step 2: Filtration in an after-filter where e.g. ammonium and manganese is removed. The treatment relies on microbial processes and may present an alternative, greener and more sustainable approach for drinking water production spending less chemicals and energy than chemical (e...

A finite difference model of the iron ore sinter process

OpenAIRE

Muller, J.; de Vries, T.L.; Dippenaar, B.A.; Vreugdenburg, J.C.

2015-01-01

Iron ore fines are agglomerated to produce sinter, which is an important feed material for blast furnaces worldwide. A model of the iron ore sintering process has been developed with the objective of being representative of the sinter pot test, the standard laboratory process in which the behaviour of specific sinter feed mixtures is evaluated. The model aims to predict sinter quality, including chemical quality and physical strength, as well as key sinter process performance parameters such ...

Surface hardening of two cast irons by friction stir processing

International Nuclear Information System (INIS)

Fujii, Hidetoshi; Kikuchi, Toshifumi; Nogi, Kiyoshi; Yamaguchi, Yasufumi; Kiguchi, Shoji

2009-01-01

The Friction Stir Processing (FSP) was applied to the surface hardening of cast irons. Flake graphite cast iron (FC300) and nodular graphite cast iron (FCD700) were used to investigate the validity of this method. The matrices of the FC300 and FC700 cast irons are pearlite. The rotary tool is a 25mm diameter cylindrical tool, and the travelling speed was varied between 50 and 150mm/min in order to control the heat input at the constant rotation speed of 900rpm. As a result, it has been clarified that a Vickers hardness of about 700HV is obtained for both cast irons. It is considered that a very fine martensite structure is formed because the FSP generates the heat very locally, and a very high cooling rate is constantly obtained. When a tool without an umbo (probe) is used, the domain in which graphite is crushed and striated is minimized. This leads to obtaining a much harder sample. The hardness change depends on the size of the martensite, which can be controlled by the process conditions, such as the tool traveling speed and the load. Based on these results, it was clarified that the FSP has many advantages for cast irons, such as a higher hardness and lower distortion. As a result, no post surface heat treatment and no post machining are required to obtain the required hardness, while these processes are generally required when using the traditional methods.

Quality and Safety Assurance of Iron Casts and Manufacturing Processes

OpenAIRE

Kukla S.

2016-01-01

The scope of this work focuses on the aspects of quality and safety assurance of the iron cast manufacturing processes. Special attention was given to the processes of quality control and after-machining of iron casts manufactured on automatic foundry lines. Due to low level of automation and huge work intensity at this stage of the process, a model area was established which underwent reorganization in accordance with the assumptions of the World Class Manufacturing (WCM). An analysis of wor...

Factors Affecting Ballability of Mixture Iron Ore Concentrates and Iron Oxide Bearing Wastes in Metallurgical Processing

Directory of Open Access Journals (Sweden)

Mfon Udo

2018-05-01

Full Text Available Iron oxide bearing wastes (IROBEWAS are produced at every segment of processing stage of sinter, molten iron and steel production. They are hard to handle and in many cases are stockpiled only to be a source of environmental pollution but can be balled into pellets. Pellet of good ballability values are transportable and recyclable as they can withstand stress they will encounter without disintegrating back to dust. But ballability is affected by some factors like the grain sizes of the materials, the moisture and binder contents of the ball mix, wettability of the balled materials and the processing perimeters of the granulator. The objective of this research work is to investigate the factors affecting ballability of mixture of iron ore concentrates and iron oxide bearing wastes (IROBEWAS in metallurgical processing. The parameters under consideration were grain size of materials, the moisture contents, the speed of balling disc, IROBEWAS and Bentonite (Binder contents of the balled mix. This was carried out by balling different volume fractions of mix containing iron oxide concentrate and IROBEWAS using a balling disc and testing the resulting balls for green compressive strength using universal testing machine. It was found that the ballability of the mixture of iron ore concentrate and IROBEWAS increases as grain sizes of the materials reduce but increases as the moisture contents and IROBEWAS content increase up to an optimum value of moisture content in the mix before it starts to reduce. The ballability also increases as the speed of the granulator (Balling disc increases within the limit of this work. It was also observed that there was an increase in ballability with slight increase in bentonite content in the mix.

REDUCING ARSENIC LEVELS IN DRINKING WATER DURING IRON REMOVAL PROCESSES

Science.gov (United States)

The presentation provides an overview of iron removal technology for the removal of arsenic from drinking water. The presentation is divided into several topic topics: Arsenic Chemistry, Treatment Selection, Treatment Options, Case Studies and Iron Removal Processes. Each topic i...

Special grain boundaries in the nugget zone of friction stir welded AA6061-T6 under various welding parameters

Energy Technology Data Exchange (ETDEWEB)

Tao, Wang [Key Lab of Liquid Structure and Heredity of Materials, Ministry of Education, Shandong University, Jinan 250061 (China); Yong, Zou, E-mail: yzou@sdu.edu.cn [Key Lab of Liquid Structure and Heredity of Materials, Ministry of Education, Shandong University, Jinan 250061 (China); Xuemei, Liu [Key Lab of Liquid Structure and Heredity of Materials, Ministry of Education, Shandong University, Jinan 250061 (China); Matsuda, Kenji [Department of Materials Science and Technology, Faculty of Engineering, University of Toyama, Toyama 930-8555 (Japan)

2016-08-01

The age hardenable AA6061-T6 plate was butt welded by friction stir welding. The total heat input, generated by friction between the tool and work piece and plastic deformation, results in a consumption of meta-stable phases in the nugget zone. Precipitation phenomena were closely related to the diffusion of the solute atoms. The existence of special grain boundaries like Σ1a and Σ3 will increase the difficulty in diffusion, which will improve the hardness in the nugget zone. Furthermore, the formation of Σ3 grain boundaries can result from an impingement of re-crystallized grains coming from texture components in twin relationship already. An appropriate strain level may benefit the development of the twin components with a similar intensity. The welding parameters have an effect on heat source mode and the strain level. Then, the type of dynamic re-crystallization and distribution of the special grain boundaries was altered by changing the parameters.

Effect of annealing process of iron powder on magnetic properties ...

Indian Academy of Sciences (India)

Administrator

Abstract. Iron powder magnetic cores are used as soft magnetic rotors, in micro special motors such as BS brake motors, refrigerator compressor motors and brushless servo motors. Heat treatment of iron powder played an important role in the magnetic properties and loss of the motor cores. After the annealing process,.

Study on the Formulation of Squid (Loligosp) Nugget Added with Yellow Pumpkin (Curcubitamoschata) Flour

OpenAIRE

Nurharyati, Lisa; ', Suparmi; Sari, N Ira

2017-01-01

This study aimed to determine the squid nugget formulation with the addition of pumpkin flour. It was evaluated for the organoleptic value and the proximate composition. The method used was an experimental method and designed as non-factorial completely randomized design (CRD). The treatments were addition of pumpkin flour into the mix, consisting of four levels, namely: N0 (without the addition of pumpkin flour), N1 (pumpkin flour 50 g), N2 (pumpkin flour 75 g) and N3 (pumpkin flour 100 g).B...

Iron behaviour in the process of stratum-infiltration uranium ore formation

International Nuclear Information System (INIS)

Shmariovich, E.M.; Golubev, V.S.

1980-01-01

Investigated has been the behaviour of iron in the process of stratum infiltration uranium mineralization. Iron is partially avacuated from the forward part of the stratum oxidation zone during the development of infiltration uranium mineralization in pyritiferous rocks. This phenomenon is characterized quantitatively and described on the basis of equations of physical chemistry and dynamics of geochemical processes. Local regions of epigenetic ferruginization caused by opposite diffusion of iron and its precipitation in oxygenous conditions often occur at the sections of sharp moderation of limonitization zone advance. Formation of similar ferruginous margins takes place in a very short geological period (less than thousand years)

Sulfur Removal by Adding Iron During the Digestion Process of High-sulfur Bauxite

Science.gov (United States)

Zhanwei, Liu; Hengwei, Yan; Wenhui, Ma; Keqiang, Xie; Dunyong, Li; Licong, Zheng; Pengfei, Li

2018-04-01

This paper proposes a novel approach to sulfur removal by adding iron during the digestion process. Iron can react with high-valence sulfur (S2O3 2-, SO3 2-, SO4 2-) to generate S2- at digestion temperature, and then S2- enter red mud in the form of Na3FeS3 to be removed. As iron dosage increases, high-valence sulfur concentration decreases, but the concentration of S2- increases; sulfur digestion rate decreases while sulfur content in red mud markedly increases; the alumina digestion rate, conversely, remains fairly stable. So sulfur can be removed completely by adding iron in digestion process, which provide a theoretical basis for the effective removal of sulfur in alumina production process.

Assessment of iron bioavailability from different bread making processes using an in vitro intestinal cell model.

Science.gov (United States)

Rodriguez-Ramiro, I; Brearley, C A; Bruggraber, S F A; Perfecto, A; Shewry, P; Fairweather-Tait, S

2017-08-01

Myo-inositol hexakisphosphate (IP6), is the main iron chelator in cereals and bread. The aim of this study was to investigate the effect of three commercial baking processes (sourdough, conventional yeast and Chorleywood Bread Making Process (CBP)) on the IP6 content of wholemeal bread, its impact on iron uptake in Caco-2 cells and the predicted bioavailability of iron from these breads with added iron, simulating a mixed-meal. The sourdough process fully degraded IP6 whilst the CBP and conventional processes reduced it by 75% compared with wholemeal flour. The iron released in solution after a simulated digestion was 8-fold higher in sourdough bread than with others but no difference in cellular iron uptake was observed. Additionally, when iron was added to the different breads digestions only sourdough bread elicited a significant ferritin response in Caco-2 cells (4.8-fold compared to the other breads) suggesting that sourdough bread could contribute towards improved iron nutrition. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

Effect of synthetic iron colloids on the microbiological NH(4)(+) removal process during groundwater purification.

Science.gov (United States)

Wolthoorn, Anke; Temminghoff, Erwin J M; van Riemsdijk, Willem H

2004-04-01

Subsurface aeration is used to oxidise Fe in situ in groundwater that is used to make drinking water potable. In a groundwater system with pH>7 subsurface aeration results in non-mobile Fe precipitate and mobile Fe colloids. Since originally the goal of subsurface aeration is to remove iron in situ, the formation of non-mobile iron precipitate, which facilitates the metal's removal, is the desired result. In addition to this intended effect, subsurface aeration may also strongly enhance the microbiological removal of ammonium (NH(4)(+)) in the purification station. Mobile iron colloids could be the link between subsurface aeration and the positive effect on the NH(4)(+) removal process. Therefore, the objective of this study was to assess whether synthetic iron colloids could improve the NH(4)(+) removal process. The effect of synthetic iron colloids on the NH(4)(+) removal process was studied using an artificial purification set-up on a laboratory scale. Columns that purified groundwater with or without added synthetic iron colloids were set up in duplicate. The results showed that the NH(4)(+) removal was significantly ( alpha = 0.05 ) increased in columns treated with the synthetic iron colloids. Cumulative after 4 months about 10% more NH(4)(+) was nitrified in the columns that was treated with the groundwater containing synthetic iron colloids. The results support the hypothesis that mobile iron colloids could be the link between subsurface aeration and the positive effect on the NH(4)(+) removal process.

Method of manufacturing iron aluminide by thermomechanical processing of elemental powders

Science.gov (United States)

Deevi, Seetharama C.; Lilly, Jr., A. Clifton; Sikka, Vinod K.; Hajaligol, Mohammed R.

2000-01-01

A powder metallurgical process of preparing iron aluminide useful as electrical resistance heating elements having improved room temperature ductility, electrical resistivity, cyclic fatigue resistance, high temperature oxidation resistance, low and high temperature strength, and/or resistance to high temperature sagging. The iron aluminide has an entirely ferritic microstructure which is free of austenite and can include, in weight %, 20 to 32% Al, and optional additions such as .ltoreq.1% Cr, .gtoreq.05% Zr or ZrO.sub.2 stringers extending perpendicular to an exposed surface of the heating element, .ltoreq.2% Ti, .ltoreq.2% Mo, .ltoreq.1% Zr, .ltoreq.1% C, .ltoreq.0.1% B, .ltoreq.30% oxide dispersoid and/or electrically insulating or electrically conductive covalent ceramic particles, .ltoreq.1 % rare earth metal, .ltoreq.1% oxygen, and/or .ltoreq.3% Cu. The process includes forming a mixture of aluminum powder and iron powder, shaping the mixture into an article such as by cold rolling the mixture into a sheet, and sintering the article at a temperature sufficient to react the iron and aluminum powders and form iron aluminide. The sintering can be followed by hot or cold rolling to reduce porosity created during the sintering step and optional annealing steps in a vacuum or inert atmosphere.

Evidence of biogeochemical processes in iron duricrust formation

Science.gov (United States)

Levett, Alan; Gagen, Emma; Shuster, Jeremiah; Rintoul, Llew; Tobin, Mark; Vongsvivut, Jitraporn; Bambery, Keith; Vasconcelos, Paulo; Southam, Gordon

2016-11-01

Canga is a moderately hard iron-rich duricrust primarily composed of goethite as a result of the weathering of banded iron formations. Canga duricrusts lack a well-developed soil profile and consequently form an innate association with rupestrian plants that may become ferruginised, contributing to canga possessing macroscopic biological features. Examination of polished canga using a field emission scanning electron microscope (FE-SEM) revealed the biological textures associated with canga extended to the sub-millimetre scale in petrographic sections and polished blocks. Laminae that formed by abiotic processes and regions where goethite cements were formed in association with microorganisms were observed in canga. Biological cycling of iron within canga has resulted in two distinct forms of microbial fossilisation: permineralisation of multispecies biofilms and mineralisation of cell envelopes. Goethite permineralised biofilms frequently formed around goethite-rich kaolinite grains in close proximity to goethite bands and were composed of micrometre-scale rod-shaped, cocci and filamentous microfossils. In contrast, the cell envelopes immobilised by authigenic iron oxides were primarily of rod-shaped microorganisms, were not permineralised and occurred in pore spaces within canga. Complete mineralisation of intact rod-shaped casts and the absence of permineralisation suggested mineralised cell envelopes may represent fossilised iron-oxidising bacteria in the canga ecosystem. Replication of these iron-oxidising bacteria appeared to infill the porous regions within canga. Synchrotron-based Fourier transform infrared (FTIR) microspectroscopy demonstrated that organic biomarkers were poorly preserved with only weak bands indicative of aliphatic methylene (CH2) associated with permineralised microbial biofilms. High resolution imaging of microbial fossils in canga that had been etched with oxalic acid supported the poor preservation of organic biomarkers within canga

Quality and Safety Assurance of Iron Casts and Manufacturing Processes

Directory of Open Access Journals (Sweden)

Kukla S.

2016-06-01

Full Text Available The scope of this work focuses on the aspects of quality and safety assurance of the iron cast manufacturing processes. Special attention was given to the processes of quality control and after-machining of iron casts manufactured on automatic foundry lines. Due to low level of automation and huge work intensity at this stage of the process, a model area was established which underwent reorganization in accordance with the assumptions of the World Class Manufacturing (WCM. An analysis of work intensity was carried out and the costs were divided in order to identify operations with no value added, particularly at individual manufacturing departments. Also an analysis of ergonomics at work stations was carried out to eliminate activities that are uncomfortable and dangerous to the workers' health. Several solutions were proposed in terms of rationalization of work organization at iron cast after-machining work stations. The proposed solutions were assessed with the use of multi-criteria assessment tools and then the best variant was selected based on the assumed optimization criteria. The summary of the obtained results reflects benefits from implementation of the proposed solutions.

Iron oxides and their applications in catalytic processes: a review

OpenAIRE

Oliveira, Luiz C. A.; Fabris, José D.; Pereira, Márcio C.

2013-01-01

A review of most of the reported studies on the use of iron oxides as catalyst in specific processes, namely Haber-Bosch reaction, Fischer-Tropsch synthesis, Fenton oxidation and photolytic molecular splitting of water to produce gaseous hydrogen, was carried out. An essential overview is thus presented, intending to address the fundamental meaning, as well as the corresponding chemical mechanisms, and perspectives on new technological potentialities of natural and synthetic iron oxides, more...

Influence of Atmospheric Processes on the Solubility and Composition of Iron in Saharan Dust.

Science.gov (United States)

Longo, Amelia F; Feng, Yan; Lai, Barry; Landing, William M; Shelley, Rachel U; Nenes, Athanasios; Mihalopoulos, Nikolaos; Violaki, Kalliopi; Ingall, Ellery D

2016-07-05

Aerosol iron was examined in Saharan dust plumes using a combination of iron near-edge X-ray absorption spectroscopy and wet-chemical techniques. Aerosol samples were collected at three sites located in the Mediterranean, the Atlantic, and Bermuda to characterize iron at different atmospheric transport lengths and time scales. Iron(III) oxides were a component of aerosols at all sampling sites and dominated the aerosol iron in Mediterranean samples. In Atlantic samples, iron(II and III) sulfate, iron(III) phosphate, and iron(II) silicates were also contributors to aerosol composition. With increased atmospheric transport time, iron(II) sulfates are found to become more abundant, aerosol iron oxidation state became more reduced, and aerosol acidity increased. Atmospheric processing including acidic reactions and photoreduction likely influence the form of iron minerals and oxidation state in Saharan dust aerosols and contribute to increases in aerosol-iron solubility.

Solar Extreme UV radiation and quark nugget dark matter model

Energy Technology Data Exchange (ETDEWEB)

Zhitnitsky, Ariel, E-mail: arz@phas.ubc.ca [Department of Physics and Astronomy, University of British Columbia, Vancouver, B.C. V6T 1Z1 (Canada)

2017-10-01

We advocate the idea that the surprising emission of extreme ultra violet (EUV) radiation and soft x-rays from the Sun are powered externally by incident dark matter (DM) particles. The energy and the spectral shape of this otherwise unexpected solar irradiation is estimated within the quark nugget dark matter model. This model was originally invented as a natural explanation of the observed ratio Ω{sub dark} ∼ Ω{sub visible} when the DM and visible matter densities assume the same order of magnitude values. This generic consequence of the model is a result of the common origin of both types of matter which are formed during the same QCD transition and both proportional to the same fundamental dimensional parameter Λ{sub QCD}. We also present arguments suggesting that the transient brightening-like 'nanoflares' in the Sun may be related to the annihilation events which inevitably occur in the solar atmosphere within this dark matter scenario.

Critical charges on strange quark nuggets and other extended objects

International Nuclear Information System (INIS)

Dicus, Duane A.; Repko, Wayne W.; Teplitz, V. L.

2008-01-01

We investigate the behavior of the critical charge for spontaneous pair production, Z C , defined as the charge at which the total energy of a K-shell electron is E=-m e , as a function of the radius R of the charge distribution. Our approach is to solve the Dirac equation for a potential V(r) consisting of a spherically symmetrical charge distribution of radius R and a Coulomb tail. For a spherical shell distribution of the type usually associated with color-flavor locked strange quark nuggets, we confirm the relation Z C =0.71R (fm) for sufficiently large R obtained by Madsen, who used an approach based on the Thomas-Fermi model. We also present results for a uniformly charged sphere and again find that Z C ∼R for large enough R. Also discussed is the behavior of Z C when simple ad hoc modifications are made to the potential for 0≤r< R.

Solar Extreme UV radiation and quark nugget dark matter model

Science.gov (United States)

Zhitnitsky, Ariel

2017-10-01

We advocate the idea that the surprising emission of extreme ultra violet (EUV) radiation and soft x-rays from the Sun are powered externally by incident dark matter (DM) particles. The energy and the spectral shape of this otherwise unexpected solar irradiation is estimated within the quark nugget dark matter model. This model was originally invented as a natural explanation of the observed ratio Ωdark ~ Ωvisible when the DM and visible matter densities assume the same order of magnitude values. This generic consequence of the model is a result of the common origin of both types of matter which are formed during the same QCD transition and both proportional to the same fundamental dimensional parameter ΛQCD. We also present arguments suggesting that the transient brightening-like "nanoflares" in the Sun may be related to the annihilation events which inevitably occur in the solar atmosphere within this dark matter scenario.

Integrating Fenton's process and ion exchange for olive mill wastewater treatment and iron recovery.

Science.gov (United States)

Reis, Patrícia M; Martins, Pedro J M; Martins, Rui C; Gando-Ferreira, Licínio M; Quinta-Ferreira, Rosa M

2018-02-01

A novel integrated methodology involving Fenton's process followed by ion exchange (IE) was proposed for the treatment of olive mill wastewater. Fenton's process was optimized and it was able to remove up to 81% of chemical oxygen demand when pH 3.5, reaction time 1 h, [Fe 2+ ] = 50 mg L -1 and [Fe 2+ ]/[H 2 O 2 ] = 0.002 were applied. In spite of the potential of this treatment approach, final iron removal from the liquid typically entails pH increase and iron sludge production. The integration of an IE procedure using Lewatit TP 207 resin was found to be able to overcome this important environmental shortcoming. The resin showed higher affinity toward Fe 3+ than to Fe 2+ . However, the iron removal efficiency of an effluent coming from Fenton's was independent of the type of the initial iron used in the process. The presence of organic matter had no significant effect over the resin iron removal efficiency. Even if some efficiency decrease was observed when a high initial iron load was applied, the adsorbent mass quantity can be easily adapted to reach the desired iron removal. The use of IE is an interesting industrial approach able to surpass Fenton's peroxidation drawback and will surely boost its full-scale application in the treatment of bio-refractory effluents.

The Influence of Friction Stir Weld Tool Form and Welding Parameters on Weld Structure and Properties: Nugget Bulge in Self-Reacting Friction Stir Welds

Science.gov (United States)

Schneider, Judy; Nunes, Arthur C., Jr.; Brendel, Michael S.

2010-01-01

Although friction stir welding (FSW) was patented in 1991, process development has been based upon trial and error and the literature still exhibits little understanding of the mechanisms determining weld structure and properties. New concepts emerging from a better understanding of these mechanisms enhance the ability of FSW engineers to think about the FSW process in new ways, inevitably leading to advances in the technology. A kinematic approach in which the FSW flow process is decomposed into several simple flow components has been found to explain the basic structural features of FSW welds and to relate them to tool geometry and process parameters. Using this modelling approach, this study reports on a correlation between the features of the weld nugget, process parameters, weld tool geometry, and weld strength. This correlation presents a way to select process parameters for a given tool geometry so as to optimize weld strength. It also provides clues that may ultimately explain why the weld strength varies within the sample population.

Treatment of highly polluted groundwater by novel iron removal process.

Science.gov (United States)

Sim, S J; Kang, C D; Lee, J W; Kim, W S

2001-01-01

The removal of ferrous iron (Fe(II)) in groundwater has been generally achieved by simple aeration, or the addition of an oxidizing agent. Aeration has been shown to be very efficient in insolubilization ferrous iron at a pH level greater than 6.5. In this study, pH was maintained over 6.5 using limestone granules under constant aeration to oxidize ferrous iron in groundwater in a limestone packed column. A sedimentation unit coupled with a membrane filtration was also developed to precipitate and filtrate the oxidized ferric compound simultaneously. Several bench-scale studies, including the effects of the limestone granule sizes, amounts and hydraulic retention time on iron removal in the limestone packed column were investigated. It was found that 550 g/L of the 7-8 mesh size limestone granules, and 20 min of hydraulic retention time in the limestone packed column, were necessary for the sufficient oxidation of 40 mg/L of iron(II) in groundwater. Long-term operation was successfully achieved in contaminated waters by removing the iron deposits on the surface of the limestone granule by continuous aeration from the bottom of the column. Periodic reverse flow helped to remove caking and fouling of membrane surface caused by the continuous filtration. Recycling of the treated water from the membrane right after reverse flow operation made possible an admissible limit of iron concentration of the treated water for drinking. The pilot-scale process was constructed and has been tested in the rural area of Korea.

Experimental analysis of influence of different lubricants types on the multi-phase ironing process

Directory of Open Access Journals (Sweden)

Milan Djordjević

2013-05-01

Full Text Available This paper is aimed at presenting results of an experimental analysis of the different types of lubricants influence on the multi-phase ironing process. Based on sliding of the metal strip between the two contact elements a special tribological model was adopted. The subject of experimental investigations was variations of the drawing force, contact pressure and the friction coefficient for each type of the applied lubricants. The ironing process was conducted in three-phases at the constant sliding velocity. The objective of this analysis was to compare all the applied lubricants in order to estimate their quality from the point of view of their applicability in the multi-phase ironing process.

EXPERIMENTAL ANALYSIS OF INFLUENCE OF DIFFERENT LUBRICANTS TYPES ON THE MULTI-PHASE IRONING PROCESS

Directory of Open Access Journals (Sweden)

Milan Djordjević

2013-09-01

Full Text Available This paper is aimed at presenting results of an experimental analysis of the different types of lubricants influence on the multi-phase ironing process. Based on sliding of the metal strip between the two contact elements a special tribological model was adopted. The subject of experimental investigations was variations of the drawing force, contact pressure and the friction coefficient for each type of the applied lubricants. The ironing process was conducted in three-phases at the constant sliding velocity. The objective of this analysis was to compare all the applied lubricants in order to estimate their quality from the point of view of their applicability in the multi-phase ironing process.

Microbial dissimilatory iron(III) reduction: Studies on the mechanism and on processes of environmental relevance

OpenAIRE

Jahn, Michael

2005-01-01

Many microbes are able to respire aerobically oxygen or anaerobically other electron acceptors for example sulphate, nitrate, manganese(IV) or Fe(III). As iron minerals are widespread in nature, dissimilatory iron(III) reduction by different microorganisms is a very important process of anaerobic respiration. The general goal of this work was to improve the knowledge of processes, in which iron-reducing microbes are said to play an important role. For this purpose, in one part the focus wa...

Laser processing of cast iron for enhanced erosion resistance

International Nuclear Information System (INIS)

Chen, C.H.; Altstetter, C.J.; Rigsbee, J.M.

1984-01-01

The surfaces of nodular and gray cast iron have been modified by CO 2 laser processing for enhanced hardness and erosion resistance. Control of the near-surface microstructure was achieved primarily by controlling resolidification of the laser melted layer through variations in laser beam/target interaction time and beam power density. Typical interaction times and power densities used were 5 msec and 500 kW/cm 2 . Two basic kinds of microstructure can be produced-a feathery microstructure with high hardness (up to 1245 HV) and a dendritic microstructure with a metastable, fully austenitic matrix and lower hardness (600 to 800 HV). Erosion testing was done using slurries of SiO 2 or SiC in water. Weight loss and crater profile measurements were used to evaluate the erosion characteristics of the various microstructures. Both ductile and gray cast iron showed marked improvement in erosion resistance after laser processing

Iron Mineral Catalyzed C-H Activation As a Potential Pathway for Halogenation Processes

Science.gov (United States)

Tubbesing, C.; Schoeler, H. F.; Benzing, K.; Krause, T.; Lippe, S.; Rudloff, M.

2014-12-01

Due to increasing drinking water demand of mankind and an expected climate change the impact of salt lakes and salt deserts will increase within the next decades. Furthermore, a rising sea level influences coastal areas like salt marshes and abets processes which will lead to elevated organohalogen formation. An additional increase of the global warming potential, of particle formation and stratospheric ozone depletion is expected. Understanding these multifaceted processes is essential for mankind to be prepared for these alterations of the atmosphere. For example, Keppler et al. (2000) described the production of volatile halogenated organic compounds via oxidation of organic matter driven by ferric iron. However, the formation of long-chained alkyl halides in salt lakes is yet undisclosed. Despite the relative "inertness" of alkanes a direct halogenation of these compounds might be envisaged. In 2005 Vaillancourt et al. discovered a nonheme iron enzyme which is able to halogenate organic compounds via generating the high valent ferryl cation as reaction center. Based on various publications about C-H activation (Bergman, 2007) we postulate a halogenation process in which an iron containing minerals catalyse the C-H bond cleavage of organic compounds in soils. The generated organic radicals are highly reactive towards halides connected to the iron complex. We suggest that next to diagenetically altered iron containing enzymes, minerals such as oxides, hydroxides and sulfides are involved in abiotic halogenation processes. We applied the amino acid methionine as organic model compound and soluble iron species as reactants. All samples were incubated in aqueous phases containing various NaCl concentrations. As a result various halogenated ethanes and ethenes were identified as reaction products. References Bergman, R. G. (2007) Nature, 446(7134) 391-393 Keppler, F., et al. (2000) Nature, 403(6767) 298-301 Vaillancourt, F. H., et al. (2005) Nature, 436(7054) 1191-1194

Effect of almond on technological, nutritional, textural and sensory characteristics of goat meat nuggets.

Science.gov (United States)

Rajkumar, V; Das, Arun K; Verma, Arun K

2014-11-01

An attempt was made through the present study to develop meat based functional food by incorporating almond nut at two different 2.5 and 5 % (Formulation 1 and 2) levels and observe its impact on the different quality attributes against control goat meat nuggets. Almond improved (P Product with 2.5 % almond had higher (P products, whereas expressible water was lower. Emulsion and products pH values increased with the addition of almond. Emulsion and products with almond had higher (P products did not differ significantly. Percent SFAs decreased (P products. Almond incorporation can be a very good approach to enhance nutritional profile of the meat products without affecting acceptability.

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

International Nuclear Information System (INIS)

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

2001-01-01

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

Charge exchange processes involving iron ions

International Nuclear Information System (INIS)

Phaneuf, R.A.

1985-01-01

A review and evaluation is given of the experimental data which are available for charge exchange processes involving iron ions and neutral H, H 2 and He. Appropriate scaling laws are presented, and their accuracy estimated for these systems. A bibliography is given of available data sources, as well as of useful data compilations and review articles. A procedure is recommended for providing single approximate formulae to the fusion community to describe total cross sections for electron capture by partially-stripped Fe/sup q+/ ions in collisions with H, H 2 and He, based on the scaling relationships suggested by Janev and Hvelplund

Hydrometallurgical process for recovering iron sulfate and zinc sulfate from baghouse dust

Science.gov (United States)

Zaromb, Solomon; Lawson, Daniel B.

1994-01-01

A process for recovering zinc/rich and iron-rich fractions from the baghouse dust that is generated in various metallurgical operations, especially in steel-making and other iron-making plants, comprises the steps of leaching the dust by hot concentrated sulfuric acid so as to generate dissolved zinc sulfate and a precipitate of iron sulfate, separating the precipitate from the acid by filtration and washing with a volatile liquid, such as methanol or acetone, and collecting the filtered acid and the washings into a filtrate fraction. The volatile liquid may be recovered distillation, and the zinc may be removed from the filtrate by alternative methods, one of which involves addition of a sufficient amount of water to precipitate hydrated zinc sulfate at 10.degree. C., separation of the precipitate from sulfuric acid by filtration, and evaporation of water to regenerate concentrated sulfuric acid. The recovery of iron may also be effected in alternative ways, one of which involves roasting the ferric sulfate to yield ferric oxide and sulfur trioxide, which can be reconverted to concentrated sulfuric acid by hydration. The overall process should not generate any significant waste stream.

Iron and stony-iron meteorites

DEFF Research Database (Denmark)

Benedix, Gretchen K.; Haack, Henning; McCoy, T. J.

2014-01-01

Without iron and stony-iron meteorites, our chances of ever sampling the deep interior of a differentiated planetary object would be next to nil. Although we live on a planet with a very substantial core, we will never be able to sample it. Fortunately, asteroid collisions provide us with a rich...... sampling of the deep interiors of differentiated asteroids. Iron and stony-iron meteorites are fragments of a large number of asteroids that underwent significant geological processing in the early solar system. Parent bodies of iron and some stony-iron meteorites completed a geological evolution similar...... to that continuing on Earth – although on much smaller length- and timescales – with melting of the metal and silicates; differentiation into core, mantle, and crust; and probably extensive volcanism. Iron and stony-iron meteorites are our only available analogues to materials found in the deep interiors of Earth...

Ductile cast iron obtaining by Inmold method with use of LOST FOAM process

Directory of Open Access Journals (Sweden)

T. Pacyniak

2010-01-01

Full Text Available The possibility of manufacturing of ductile cast iron castings by Inmold method with use of LOST FOAM process was presented in this work. The spheroidization was carried out by magnesium master alloy in amounts of 1% casting mass. Nodulizer was located in the reactive chamber in the gating system made of foamed polystyrene. Pretests showed, that there are technical possibilities of manufacturing of casts from ductile cast iron in the LOST FOAM process with use of spheroidization in mould.

Atmospheric processing of combustion aerosols as a source of soluble iron to the open ocean

OpenAIRE

伊藤, 彰記; ITO, Akinori

2015-01-01

The majority of bioavailable iron (Fe) from the atmosphere is delivered from arid and semiarid regions to the oceans because the global deposition of iron from combustion sources is small compared with that from mineral dust. Atmospheric processing of mineral aerosols by inorganic and organic acids from anthropogenic and natural sources has been shown to increase the iron solubility of soils (initially < 0.5%) up to about 10%. On the other hand, atmospheric observations have shown that iron i...

Fine tuning of dwelling time in friction stir welding for preventing material overheating, weld tensile strength increase and weld nugget size decrease

Directory of Open Access Journals (Sweden)

Mijajlović Miroslav M.

2016-01-01

Full Text Available After successful welding, destructive testing into test samples from Al 2024-T351 friction stir butt welds showed that tensile strength of the weld improve along the joint line, while dimensions of the weld nugget decrease. For those welds, both the base material and the welding tool constantly cool down during the welding phase. Obviously, the base material became overheated during the long dwelling phase what made conditions for creation of joints with the reduced mechanical properties. Preserving all process parameters but varying the dwelling time from 5-27 seconds a new set of welding is done to reach maximal achievable tensile strength. An analytical-numerical-experimental model is used for optimising the duration of the dwelling time while searching for the maximal tensile strength of the welds

Clean recycle and utilization of hazardous iron-bearing waste in iron ore sintering process.

Science.gov (United States)

Gan, Min; Ji, Zhiyun; Fan, Xiaohui; Chen, Xuling; Zhou, Yang; Wang, Guojing; Tian, Ye; Jiang, Tao

2018-04-18

Applying recycled iron-bearing waste materials (RIM) into iron ore sintering process is the general disposal approach worldwide, while its use is still a thorny problem. Results showed that adding RIM increased contents of hazardous elements (K, Na, Pb, Zn, and Cl) in sinter product, and also enhanced emission concentration of PM 2.5 in flue gas; increasing reaction temperature, and contents of CaO & coke breeze in raw mixtures improved hazardous elements removal. Based on these features, a novel method through granulating natural iron ores and RIM separately and distributing granulated RIM in bottom sintering layers was proposed for clean RIM cycle. When recycling 5% RIM, granulating RIM separately with higher contents of CaO and coke breeze removed hazardous elements effectively, the contents of which in sinter were reduced to comparable level of the case without RIM. Moreover, distributing RIM in bottom sintering layer reached intensive release of hazardous elements and PM 2.5 during sintering, which reduced the flue gas volume needing purification by about 2/3. Through activated carbon purification, about 60% of PM 2.5 comprised high contents of hazardous elements was removed. Novel technique eliminated the negative impact of RIM and has the prospect to reach clean recycle in sinter-making plants. Copyright © 2018. Published by Elsevier B.V.

Experimental and computer simulation results of the spot welding process using SORPAS software

International Nuclear Information System (INIS)

Al-Jader, M A; Cullen, J D; Athi, N; Al-Shamma'a, A I

2009-01-01

The highly competitive nature of the automotive industry drives demand for improvements and increased precision engineering in resistance spot welding. Currently there are about 4300 weld points on the average steel vehicle. Current industrial monitoring systems check the quality of the nugget after processing 15 cars, once every two weeks. The nuggets are examined off line using a destructive process, which takes approximately 10 days to complete causing a long delay in the production process. This paper presents a simulation of the spot welding growth curves, along with a comparison to growth curves performed on an industrial spot welding machine. The correlation of experimental results shows that SORPAS simulations can be used as an off line measurement to reduce factory energy usage. The first section in your paper

SURFACE CAST IRON STRENGTHENING USING COMBINED LASER AND ULTRASONIC PROCESSING

Directory of Open Access Journals (Sweden)

O. G. Devojno

2013-01-01

Full Text Available The paper provides an analysis of ultrasonic surface plastic deformation and subsequent laser thermal strengthening of gray cast iron parts in the regime of hardening from a solid state with the purpose to obtain strengthened surface layers of bigger depth and less roughness of the processed surface. Program complex ANSYS 11.0 has been used for calculation of temperature fields induced by laser exposure.  The appropriate regime of laser processing without surface fusion has been selected on the basis of the applied complex. The possibility of displacement in the bottom boundary of α–γ-transformation temperature  for СЧ20 with 900 °С up to 800 °С is confirmed due to preliminary ultrasonic surface plastic deformation of the surface that allows to expand technological opportunities of laser quenching  of gray  cast iron from a solid state. 

Biogeochemical processes controlling density stratification in an iron-meromictic lake

Science.gov (United States)

Nixdorf, E.; Boehrer, B.

2015-06-01

Biogeochemical processes and mixing regime of a lake can control each other mutually. The prominent case of iron meromixis is investigated in Waldsee near Doebern, a small lake that originated from surface mining of lignite. From a four years data set of monthly measured electrical conductivity profiles, we calculated summed conductivity as a quantitative variable reflecting the amount of electro-active substances in the entire lake. Seasonal variations followed changing chemocline height. Coinciding changes of electrical conductivities in the monimolimnion indicated that a considerable share of substances, precipitated by the advancing oxygenated epilimnion, re-dissolved in the remaining anoxic deep waters and contributed considerably to the density stratification. In addition, we constructed a lab experiment, in which aeration of monimolimnetic waters removed iron compounds and organic material. Precipitates could be identified by visual inspection. Introduced air bubbles ascended through the water column and formed a water mass similar to the mixolimnetic Waldsee water. The remaining less dense water remained floating on the nearly unchanged monimolimnetic water. In conclusion, iron meromixis as seen in Waldsee did not require two different sources of incoming waters, but the inflow of iron rich deep groundwater and the aeration through the lake surface were fully sufficient.

Methodology of Fault Diagnosis in Ductile Iron Melting Process

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Perzyk M.

2016-12-01

Full Text Available Statistical Process Control (SPC based on the Shewhart’s type control charts, is widely used in contemporary manufacturing industry, including many foundries. The main steps include process monitoring, detection the out-of-control signals, identification and removal of their causes. Finding the root causes of the process faults is often a difficult task and can be supported by various tools, including data-driven mathematical models. In the present paper a novel approach to statistical control of ductile iron melting process is proposed. It is aimed at development of methodologies suitable for effective finding the causes of the out-of-control signals in the process outputs, defined as ultimate tensile strength (Rm and elongation (A5, based mainly on chemical composition of the alloy. The methodologies are tested and presented using several real foundry data sets. First, correlations between standard abnormal output patterns (i.e. out-of-control signals and corresponding inputs patterns are found, basing on the detection of similar patterns and similar shapes of the run charts of the chemical elements contents. It was found that in a significant number of cases there was no clear indication of the correlation, which can be attributed either to the complex, simultaneous action of several chemical elements or to the causes related to other process variables, including melting, inoculation, spheroidization and pouring parameters as well as the human errors. A conception of the methodology based on simulation of the process using advanced input - output regression modelling is presented. The preliminary tests have showed that it can be a useful tool in the process control and is worth further development. The results obtained in the present study may not only be applied to the ductile iron process but they can be also utilized in statistical quality control of a wide range of different discrete processes.

Finite element simulation of ironing process under warm conditions

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Swadesh Kumar Singh

2014-01-01

Full Text Available Metal forming is one of the most important steps in manufacturing of a large variety of products. Ironing in deep drawing is done by adjusting the clearance between the punch and the die and allow the material flow over the punch. In the present investigation effect of extent of ironing behavior on the characteristics of the product like thickness distribution with respect to temperature was studied. With the help of finite element simulation using explicit finite element code LS-DYNA the stress in the drawn cup were predicted in the drawn cup. To increase the accuracy in the simulation process, numbers of integration points were increased in the thickness direction and it was found that there is very close prediction of finite element results to that of experimental ones.

Microbial processes in banded iron formation deposition

DEFF Research Database (Denmark)

Posth, Nicole; Konhauser, Kurt; Kappler, Andreas

2013-01-01

, remains unresolved. Evidence of an anoxic Earth with only localized oxic areas until the Great Oxidation Event ca 2·45 to 2·32 Ga makes the investigation of O2-independent mechanisms for banded iron formation deposition relevant. Recent studies have explored the long-standing proposition that Archean......Banded iron formations have been studied for decades, particularly regarding their potential as archives of the Precambrian environment. In spite of this effort, the mechanism of their deposition and, specifically, the role that microbes played in the precipitation of banded iron formation minerals...... banded iron formations may have been formed, and diagenetically modified, by anaerobic microbial metabolisms. These efforts encompass a wide array of approaches including isotope, ecophysiological and phylogeny studies, molecular and mineral marker analysis, and sedimentological reconstructions. Herein...

Dark Matter searches using gravitational wave bar detectors: quark nuggets and newtorites

CERN Document Server

Bassan, M; D'Antonio, S.; Fafone, V.; Giordano, G.; Marini, A.; Minenkov, Y.; Modena, I.; Pallottino, G.V.; Pizzella, G.; Rocchi, A.; Ronga, F.; Visco, M.

2016-01-01

Many experiments have searched for supersymmetric WIMP dark matter, with null results. This may suggest to look for more exotic possibilities, for example compact ultra-dense quark nuggets, widely discussed in literature with several different names. Nuclearites are an example of candidate compact objects with atomic size cross section. After a short discussion on nuclearites, the result of a nuclearite search with the gravitational wave bar detectors Nautilus and Explorer is reported. The geometrical acceptance of the bar detectors is 19.5 $\\rm m^2$ sr, that is smaller than that of other detectors used for similar searches. However, the detection mechanism is completely different and is more straightforward than in other detectors. The experimental limits we obtain are of interest because, for nuclearites of mass less than $10^{-5}$ g, we find a flux smaller than that one predicted considering nuclearites as dark matter candidates. Particles with gravitational only interactions (newtorites) are another examp...

Processes underlying the nutritional programming of embryonic development by iron deficiency in the rat.

Directory of Open Access Journals (Sweden)

Angelina Swali

Full Text Available Poor iron status is a global health issue, affecting two thirds of the world population to some degree. It is a particular problem among pregnant women, in both developed and developing countries. Feeding pregnant rats a diet deficient in iron is associated with both hypertension and reduced nephron endowment in adult male offspring. However, the mechanistic pathway leading from iron deficiency to fetal kidney development remains elusive. This study aimed to establish the underlying processes associated with iron deficiency by assessing gene and protein expression changes in the rat embryo, focussing on the responses occurring at the time of the nutritional insult. Analysis of microarray data showed that iron deficiency in utero resulted in the significant up-regulation of 979 genes and down-regulation of 1545 genes in male rat embryos (d13. Affected processes associated with these genes included the initiation of mitosis, BAD-mediated apoptosis, the assembly of RNA polymerase II preinitiation complexes and WNT signalling. Proteomic analyses highlighted 7 proteins demonstrating significant up-regulation with iron deficiency and the down-regulation of 11 proteins. The main functions of these key proteins included cell proliferation, protein transport and folding, cytoskeletal remodelling and the proteasome complex. In line with our recent work, which identified the perturbation of the proteasome complex as a generalised response to in utero malnutrition, we propose that iron deficiency alone leads to a more specific failure in correct protein folding and transport. Such an imbalance in this delicate quality-control system can lead to cellular dysfunction and apoptosis. Therefore these findings offer an insight into the underlying mechanisms associated with the development of the embryo during conditions of poor iron status, and its health in adult life.

Aceitação sensorial de reestruturados empanados elaborados com filé de peito de galinhas matrizes de corte e poedeiras comerciais Sensory acceptance of nuggets prepared with broiler breeder and spent layer hens breast meat

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Tatiana Pacheco Nunes

2006-12-01

Full Text Available Em 2005, no Brasil, o alojamento de galinhas poedeiras comerciais e de matrizes de corte somados foi de 109 milhões de cabeças, sendo que um número próximo a este deve ter sido descartado no mesmo período. Este grande número de galinhas descartadas contrasta com a falta de mercado consumidor e o baixo valor comercial alcançado por estas aves. A utilização da carne de galinhas na elaboração de produtos de conveniência poderia agregar valor e ampliar o consumo desta matéria-prima. Diante do exposto, o objetivo deste trabalho foi elaborar produtos empanados tipo nuggets, utilizando carne de galinhas de descarte (matrizes de corte e poedeiras comercias brancas e avaliar a aceitação pelo consumidor destes produtos, em comparação com nuggets elaborados com carne de frango. Os produtos desenvolvidos foram avaliados por análise sensorial, utilizando testes de aceitação e de intenção de compra em localização central (400 provadores. Não foram encontradas diferenças (p > 0,05 na aceitação sensorial nem na intenção de compra entre os três diferentes produtos avaliados. Concluiu-se que a elaboração de produtos empanados pode representar uma boa alternativa para a utilização de filés de peito de galinhas, agregando maior valor a estas aves ao final do ciclo de postura.In Brazil, the flock size of layer and broiler breeder hens housed in 2005 was 109 million. A similar number of hens might be spent in this period. This great number of spent hens contrasts with the absence of consumer market and the low commercial value reached by these birds. The manufacture of convenience products using spent hens meat could add value and elevate the consumption of this raw material. Thus, the purpose of this study was to develop nuggets made with spent hens (white layers and broiler breeders meat and evaluate the consumer acceptance of these products in comparison to nuggets elaborated with broiler meat. Sensory evaluation of acceptance

Dissolution of copper and iron from malachite ore and precipitation of copper sulfate pentahydrate by chemical process

OpenAIRE

H. Kokes; M.H. Morcali; E. Acma

2014-01-01

The present work describes an investigation of a chemical process for the recovery of copper and iron from malachite ore. For the dissolution of copper and iron, H2SO4 was employed as well as H2O2 as an oxidizing agent. The effects of reaction temperature and time, acid concentration, liquid-to-solid ratio and agitation rate on the copper and iron percentage were investigated. Following the steps of dissolving the copper and iron sulfate and filtering, iron (III) hydroxide was precipitated by...

Study and modeling of the ironing process on a multi-layered polymer coated low-carbon steel

Science.gov (United States)

Selles Canto, Miguel Angel

The ironing process is the most crucial step in the manufacture of cans. Sheet steel covered by three polymer layers can be used as the starting material, but this coating must neither break nor fail in any manner in order to be considered as a viable and effective alternative to traditional practice. During ironing, the deformations are severe and high pressures exist at the tool-workpiece interface. Thickness reductions inherent in ironing require a large amount of surface generation. Deterioration of the coating in this delicate operation might enable direct contact of the stored food or drink with the metal. As can be appreciated, the key to the use of polymer-coated steel sheets in the manufacture of cans lies in the survival of these layers during the ironing process. Another important issue is the roughness of the newly-generated surface, because it should be possible to decorate the can without any difficulty. Changing the traditional manufacture of metallic containers such as cans and using this new coated material permits great reduction in environmental contaminants produced as a result of avoiding the formation of Volatile Organic Compounds (VOCs) during the manufacture of the polymer layers. This reduction is even greater because of not using additional lubricants due to the self-lubricanting property of the solid polymer coating layers during the drawing process. These objectives, together with the improvement of the mechanical characteristics and the adhesion of the painting or decorative priming, are realized by the use of the proposed material. In the existing bibliography about ironing processes on coated materials, some authors propose the use of the Upper Bound Theorem for modeling the material behavior. The present research shows for the first time the modeling of the ironing process on a three-layer polymer coated material. In addition, it takes into account the cases in which successful ironing is produced and those in which ones the ironing

Indentation Creep Behavior of Nugget Zone of Friction Stir Welded 2014 Aluminum Alloy

Science.gov (United States)

Das, Jayashree; Robi, P. S.; Sankar, M. Ravi

2018-04-01

The present study is aimed at evaluating the creep behavior of the nugget zone of friction welded 2014 Aluminum alloy by indentation creep tests. Impression creep testing was carried out at different temperatures of 300°C, 350°C and 400 °C with stress 124.77MPa, 187.16MPa, 249.55 MPa using a 1.0 mm diameter WC indenter. Experiments were conducted till the curve enters the steady state creep region. Constitutive modeling of creep behavior was carried out considering the temperature, stress and steady state creep rate. Microstructural investigation of the crept specimen at 400°C temperature and 187.16 MPa load was carried out and found that the small precipitates accumulate along the grain boundaries at the favorable conditions of the creep temperature and stress, new precipitates evolve due to the ageing. The grains are broken and deformed due to the creep phenomena.

Microstructures and formation mechanism of hypoeutectic white cast iron by isothermal electromagnetic rheocast process

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Zhang Wanning

2010-05-01

Full Text Available An investigation was made on the evolution of microstructures of hypoeutectic white cast iron slurry containing 2.5wt.%C and 1.8wt.%Si produced by rheocasting in which the solidifying alloy was vigorously agitated by electromagnetic stirrer during isothermal cooling processes. The results indicated that under the proper agitating temperatures and speeds applied, the dendrite structures in white cast iron slurry were gradually evolved into spherical structures during a certain agitating time. It also revealed that the bent dendrites were formed by either convection force or by the growth of the dendrites themselves in the bending direction; then, as they were in solidifying, they were gradually being alternated into separated particles and into more spherical structures at the end of the isothermal cooling process. Especially, the dendrites were granulated as the bending process proceeding, which suggested that they were caused by unwanted elements such as sulfur and phosphor usually contained in engineering cast iron. Convective flow of the melt caused corrosion on the dendritic segments where they were weaker in strength and lower in melting temperature because of higher concentration of sulfur or phosphor. And the granulation process for such dendrites formed in the melt became possible under the condition. Certainly, dendrite fragments are another factors considerable to function for spherical particles formation. A new mechanism, regarding to the rheocast structure formation of white cast iron, was suggested based on the structural evolution observed in the study.

On the crystalline structures of iron oxides formed during the removal process of iron in water

International Nuclear Information System (INIS)

Cho, Bongyeon; Fujita, Kenji; Oda, Katsuro; Ino, Hiromitsu

1993-01-01

The iron oxide samples collected from both filtration and batch reactors were analysed by X-ray diffraction and Moessbauer spectroscopy. In the filtration of water containing iron, the oxidized form of iron was determined to be ferrihydrite. In contrast, in the batch experiment without filtration, iron was oxidized to microcrystalline goethite. (orig.)

Heterocyclic aromatic amine content in chicken burgers and chicken nuggets sold in fast food restaurants and effects of green tea extract and microwave thawing on their formation

Science.gov (United States)

The aims of the current study were to investigate the presence of carcinogenic and mutagenic heterocyclic aromatic amines (HAAs) in chicken burgers (CBs) and chicken nuggets (CNs) purchased from fast food restaurants and the effects of green tea extract addition (GTE) to the covering material as wel...

Valorizing waste iron powder in biogas production: Hydrogen sulfide control and process performances.

Science.gov (United States)

Andriamanohiarisoamanana, Fetra J; Shirai, Tomoya; Yamashiro, Takaki; Yasui, Seiichi; Iwasaki, Masahiro; Ihara, Ikko; Nishida, Takehiro; Tangtaweewipat, Suchon; Umetsu, Kazutaka

2018-02-15

Biogas is composed of different gases including hydrogen sulfide (H 2 S), which is a hazardous gas that damages pipes and generators in anaerobic digestion system. The objective of this study was to control H 2 S by waste iron powder produced by laser cutting machine in a steel and iron industry. Waste iron powder was mixed with dairy manure at a concentration between 2.0 and 20.0 g/L in batch experiments, while the concentration was varied between 1.0 and 4.0 g/L in bench experiment. In batch experiment, a reduction of up to 93% of H 2 S was observed at waste iron powder of 2.0 g/L (T1), while the reduction was of more than 99% at waste iron powder beyond 8.0 g/L (T4 ∼ T6). The total sulfide concentration (S T ) increased together with waste iron powder concentration and was fitted with a quadratic equation with a maximum S T of 208.0 mg/L at waste iron powder of 20.2 g/L. Waste iron powder did not have significant effect on methane yield in batch and bench experiments. However, hydrolysis rate constant was increased by almost 100%, while the lag-phase period was reduced to half in test digesters compared to that in control digester. In bench experiment, H 2 S concentration was reduced by 89% at 2.0 g/L, while 50% at 1.0 g/L. Therefore, waste iron powder was effectively removed H 2 S and did not affect negatively anaerobic digestion process. Copyright © 2017 Elsevier Ltd. All rights reserved.

Development of Powder-in-Tube Processed Iron Pnictide Wires and Tapes

KAUST Repository

Ma, Yanwei

2011-06-01

The development of PIT fabrication process of iron pnictide superconducting wires and tapes has been reviewed. Silver was found to be the best sheath material, since no reaction layer was observed between the silver sheath and the superconducting core. The grain connectivity of iron pnictide wires and tapes has been markedly improved by employing Ag or Pb as dopants. At present, critical current densities in excess of 3750 A /cm 2 (I c = 37.5 A) at 4.2 K have been achieved in Ag-sheathed SrKFeAs wires prepared with the above techniques, which is the highest value obtained in iron-based wires and tapes so far. Moreover, Ag-sheathed Sm-1111 superconducting tapes were successfully prepared by PIT method at temperatures as low as ̃ 900 °C, instead of commonly used temperatures of ̃ 1200 °C. These results demonstrate the feasibility of producing superconducting pnictide composite wires, even grain boundary properties require much more attention. © 2010 IEEE.

The effect of irradiation and thermal process on beef heme iron concentration and color properties

International Nuclear Information System (INIS)

Mistura, Liliana Perazzini Furtado; Colli, Celia

2009-01-01

The aim of this study was to evaluate the influence of irradiation and thermal process on the heme iron (heme-Fe) concentration and color properties of Brazilian cattle beef. Beef samples (patties and steaks) were irradiated at 0-10 kGy and cooked in a combination oven at 250 deg C for 9 minutes with 70% humidity. Total iron and heme iron (heme-Fe) concentrations were determined. The data were compared by multiple comparisons and fixed- effects ANOVA. Irradiation at doses higher than 5 kGy significantly altered the heme-Fe concentration. However, the sample preparation conditions interfered more in the heme-Fe content than did the irradiation. Depending on the animal species, meat heme iron levels between 35 and 52% of the total iron are used for dietetic calculations. In this study the percentage of heme-iron was, on average, 70% of the total iron showing that humidity is an important factor for its preservation. The samples were analyzed instrumentally for CIE L * , a * , and b * values. (author)

Prediction of ferric iron precipitation in bioleaching process using partial least squares and artificial neural network

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Golmohammadi Hassan

2013-01-01

Full Text Available A quantitative structure-property relationship (QSPR study based on partial least squares (PLS and artificial neural network (ANN was developed for the prediction of ferric iron precipitation in bioleaching process. The leaching temperature, initial pH, oxidation/reduction potential (ORP, ferrous concentration and particle size of ore were used as inputs to the network. The output of the model was ferric iron precipitation. The optimal condition of the neural network was obtained by adjusting various parameters by trial-and-error. After optimization and training of the network according to back-propagation algorithm, a 5-5-1 neural network was generated for prediction of ferric iron precipitation. The root mean square error for the neural network calculated ferric iron precipitation for training, prediction and validation set are 32.860, 40.739 and 35.890, respectively, which are smaller than those obtained by PLS model (180.972, 165.047 and 149.950, respectively. Results obtained reveal the reliability and good predictivity of neural network model for the prediction of ferric iron precipitation in bioleaching process.

Implementation of fluidized granulated iron reactors in a chromate remediation process

International Nuclear Information System (INIS)

Müller, P.; Lorber, K.E.; Mischitz, R.; Weiß, C.

2014-01-01

A new approach concerning in-situ remediation on source (‘hot-spot’) decontamination of a chromate damage in connection with an innovative pump-and-treat-technique has been developed. Iron granulates show significant higher reduction rates, using fluidized bed conditions, than a literature study with a fixed bed installation of small-sized iron granules. First results from an abandoned tannery site concerning injections of sodium dithionite as a chromate reductant for the vadose zone in combination with a pump-and-treat-method, allying the advantages of granulated zero valent iron (ZVI), are reported. Reduction amounts of chromate have been found up to 88% compared with initial values in the soil after a soil water exchange of 8 pore volumes within 2.5 months. Chromate concentrations in the pumped effluent have been reduced to under the detection limit of 0.005 mg/L by treatment with ZVI in the pilot plant. - Highlights: • Fe-granules show high Cr(VI)-reduction rates using fluidized bed conditions. • No respective negligible passivation effects on the surface of the iron granulates. • P and T-method by using ZVI in a FBR is very effective for Cr(VI) remediation. • The process provides no increase in salinity of the treated effluent

Uranium,Radium and Iron Absorption from Liquid Waste Uranium Ore Processing by Zeolite

International Nuclear Information System (INIS)

Wismawati, T; Sorot sudiro, A; Herjati, T

1998-01-01

The aim of this work is to determine zeolites sorption capacity and the distribution coefficient of uranium, radium, and iron in zeolite-liquid waste system. Mineralogical composition of zeolite used in the experiment has been determine by examining the thin sections of zeolite grains under a microscope. Zeolite has ben activated by the dilute sulfuric acid or sodium hydroxide solution. The results show that the use of 0.25 N sodium hydroxide solution could be optimizing the zeolite for uranium and iron ions sorption and that of 0.1 N sulfuric acid solution is for radium sorption. The re-activation process has been carried out in three hours. Under such a condition, the sorption efficiency of zeolite to those ions have been known to be 45.85% for uranium, 96.63 % for iron and 87.80 % for radium. The distribution coefficients of uranium, radium and iron ion in zeolite-liquid waste system have been calculated 0.85, 7.02, and 28.65 ml/g respectively

Study of ferrallitisation process in soil by application of isotopic dilution kinetic technique to iron

International Nuclear Information System (INIS)

Thomann, Christiane

1978-01-01

Isotopic dilution kinetic technique applied to iron may contribute to make clear the conditions of ''potential'' mobility of iron in soils, under the action of three factors: moisture, incubation period and organic matter imputs. Comparison between surface horizons of three tropical soils: leached ferruginous tropical soil, weakly ferrallitic red soil and ferrallitic soil shows that in the ferrallitisation process, weakly ferrallitic soil would take place between the two other types of soils with a maximum mobility of iron. This mobility decreases when organic matter rate decreases leading then to ''beige'' soil (ferruginous leached tropical soil), and when hydroxide rate increases, which leads to ferrallitic soil. In podzol (A 1 horizon), for the same rate of organic matter, potential mobility of iron is higher than in ferallitic soil, because it contains ten times more free iron than the podzol [fr

Weld Growth Mechanisms and Failure Behavior of Three-Sheet Resistance Spot Welds Made of 5052 Aluminum Alloy

Science.gov (United States)

Li, Yang; Yan, Fuyu; Luo, Zhen; Chao, Y. J.; Ao, Sansan; Cui, Xuetuan

2015-06-01

This paper investigates the weld nugget formation in three-sheet aluminum alloy resistance spot welding. The nugget formation process in three equal thickness sheets and three unequal thickness sheets of 5052 aluminum alloy were studied. The results showed that the nugget was initially formed at the workpiece/workpiece interfaces (i.e., both upper interface and lower interface). The two small nuggets then grew along the radial direction and axial direction (welding direction) as the welding time increased. Eventually, the two nuggets fused into one large nugget. During the welding process, the Peltier effect between the Cu-Al caused the shift of the nugget in the welding direction. In addition, the mechanical strength and fracture mode of the weld nuggets at the upper and lower interfaces were also studied using tensile shear specimen configuration. Three failure modes were identified, namely interfacial, mixed, and pullout. The critical welding time and critical nugget diameter corresponding to the transitions of these modes were investigated. Finally, an empirical failure load formula for three-sheet weld similar to two-sheet spot weld was developed.

REMOVAL OF ARSENIC FROM DRINKING WATER SUPPLIES BY IRON REMOVAL PROCESS

Science.gov (United States)

This design manual is an in-depth presentation of the steps required to design and operate a water treatment plant for removal of arsenic in the As (V) form from drinking water using an iron removal process. The manual also discusses the capital and operating costs including many...

Colour Metallography of Cast Iron - Chapter 2: Grey Iron (Ⅱ

Directory of Open Access Journals (Sweden)

Zhou Jiyang

2009-08-01

Full Text Available Cast iron, as a traditional metal material, has advantages of low total cost, good castability and machinability, good wear resistance and low notch sensitivity, and is still facing tough challenge in quality, property and variety of types etc. Experts and engineers studying and producing iron castings all around world extremely concern this serious challenge. Over more than 30 years, a great of research work has been carried out on how to further improve its property, expand its application and combine cast iron technology with some hi-techs (for example, computer technology. Nevertheless, cast iron is a multi-element and multi-phase alloy and has complex and variety of structures and still has great development potential in structure and property. For further studying and developing cast iron, theoretical research work is important promise, and the study on solidification process and control mechanism of graphite morphology is fundamental for improving property of cast iron and developing new type of cast iron. Metallography of cast iron normally includes two sections: liquid phase transformation and solid phase transformation. The book, Colour Metallography of Cast Iron, uses colour metallography technique to study solidification structures of cast irons: graphite, carbides, austenite and eutectics; and focuses on solidification processes. With progress of modern solidification theory, the control of material solidification process becomes important measure for improving traditional materials and developing new materials. Solidification structure not only influences mechanical and physical properties of cast iron, but also affects its internal quality. The book uses a large amount of colour photos to describe the formation of solidification structures and their relations. Crystallization phenomena, which cannot be displayed with traditional metallography, are presented and more phase transformation information is obtained from these colour

Oxidation of adsorbed ferrous iron: kinetics and influence of process conditions.

Science.gov (United States)

Buamah, R; Petrusevski, B; Schippers, J C

2009-01-01

For the removal of iron from groundwater, aeration followed with rapid (sand) filtration is frequently applied. Iron removal in this process is achieved through oxidation of Fe(2 + ) in aqueous solution followed by floc formation as well as adsorption of Fe(2 + ) onto the filter media. The rate of oxidation of the adsorbed Fe(2 + ) on the filter media plays an important role in this removal process. This study focuses on investigating the effect of pH on the rate of oxidation of adsorbed Fe(2 + ). Fe(2 + ) has been adsorbed, under anoxic conditions, on iron oxide coated sand (IOCS) in a short filter column and subsequently oxidized by feeding the column with aerated water. Ferrous ions adsorbed at pH 5, 6, 7 and 8 demonstrated consumption of oxygen, when aerated water was fed into the column. The oxygen uptake at pH 7 and 8 was faster than at pH 5 and 6. However the difference was less pronounced than expected. The difference is attributed to the pH buffering effect of the IOCS. At feedwater pH 5, 6 and 7 the pH in the effluent was higher than in the influent, while a pH drop should occur because of oxidation of adsorbed Fe(2 + ). At pH 8, the pH dropped. These phenomena are attributed to the presence of calcium and /or ferrous carbonate in IOCS.

Predictive modelling of Fe(III) precipitation in iron removal process for bioleaching circuits.

Science.gov (United States)

Nurmi, Pauliina; Ozkaya, Bestamin; Kaksonen, Anna H; Tuovinen, Olli H; Puhakka, Jaakko A

2010-05-01

In this study, the applicability of three modelling approaches was determined in an effort to describe complex relationships between process parameters and to predict the performance of an integrated process, which consisted of a fluidized bed bioreactor for Fe(3+) regeneration and a gravity settler for precipitative iron removal. Self-organizing maps were used to visually evaluate the associations between variables prior to the comparison of two different modelling methods, the multiple regression modelling and artificial neural network (ANN) modelling, for predicting Fe(III) precipitation. With the ANN model, an excellent match between the predicted and measured data was obtained (R (2) = 0.97). The best-fitting regression model also gave a good fit (R (2) = 0.87). This study demonstrates that ANNs and regression models are robust tools for predicting iron precipitation in the integrated process and can thus be used in the management of such systems.

Dissolution of copper and iron from malachite ore and precipitation of copper sulfate pentahydrate by chemical process

Directory of Open Access Journals (Sweden)

H. Kokes

2014-03-01

Full Text Available The present work describes an investigation of a chemical process for the recovery of copper and iron from malachite ore. For the dissolution of copper and iron, H2SO4 was employed as well as H2O2 as an oxidizing agent. The effects of reaction temperature and time, acid concentration, liquid-to-solid ratio and agitation rate on the copper and iron percentage were investigated. Following the steps of dissolving the copper and iron sulfate and filtering, iron (III hydroxide was precipitated by adjusting the pH level of the solution. Subsequently, copper sulfate pentahydrate was obtained by using various precipitants (i.e. ethanol, methanol and sulfuric acid.

Change of pH and Iron Ion Concentration During Photodegradation of TCE with Ferrioxalate/UVvis Process

International Nuclear Information System (INIS)

Hareyama, Wataru; Suto, Koichi; Inoue, Chihiro; Chida, Tadashi; Nakazawa, Hiroshi

2006-01-01

Recently, some studies show various organic compounds such as pesticides and dyes degraded with the irradiation of ultraviolet light and visible light in the presence of oxalic acid and ferric ion (ferrioxalate/UVvis process). The process has much advance than other technologies because it can utilize the wavelength of 300∼450nm and also under the condition of neutral pH. Chlorinated organic compounds such as trichloroethene (TCE), which have caused ground water pollution on a lot of sites, have never been applied by photodegradation with this process. In this study, we showed the degradation of TCE in the presence of oxalic acid and iron ion and the change of pH, ferric and ferrous ion concentration during the photodegradation of TCE with ferrioxalate/UV-vis process. TCE was degraded in the presence of oxalic acid and iron ion. In the reactions, the equilibrium of oxalate ion and iron ion is important since it determines the amount of ferrioxalate complex which absorbs light and induces the reactions of the degradation of TCE. Thus, the pH value and iron ion concentration are the important factors which determine the amount of ferrioxalate complex. The pH is nearly constant during the photodegradation of TCE. The ferrous ion concentration was decreased as soon as beginning photodegradation of TCE, and then the ferrous ion concentration and ferric ion concentration became constant

Mammalian iron metabolism and its control by iron regulatory proteins☆

Science.gov (United States)

Anderson, Cole P.; Shen, Lacy; Eisenstein, Richard S.; Leibold, Elizabeth A.

2013-01-01

Cellular iron homeostasis is maintained by iron regulatory proteins 1 and 2 (IRP1 and IRP2). IRPs bind to iron-responsive elements (IREs) located in the untranslated regions of mRNAs encoding protein involved in iron uptake, storage, utilization and export. Over the past decade, significant progress has been made in understanding how IRPs are regulated by iron-dependent and iron-independent mechanisms and the pathological consequences of IRP2 deficiency in mice. The identification of novel IREs involved in diverse cellular pathways has revealed that the IRP–IRE network extends to processes other than iron homeostasis. A mechanistic understanding of IRP regulation will likely yield important insights into the basis of disorders of iron metabolism. This article is part of a Special Issue entitled: Cell Biology of Metals. PMID:22610083

Advanced landfill leachate treatment using iron-carbon microelectrolysis- Fenton process: Process optimization and column experiments.

Science.gov (United States)

Wang, Liqun; Yang, Qi; Wang, Dongbo; Li, Xiaoming; Zeng, Guangming; Li, Zhijun; Deng, Yongchao; Liu, Jun; Yi, Kaixin

2016-11-15

A novel hydrogen peroxide-enhanced iron-carbon (Fe-C) microelectrolysis reactor was proposed for the pretreatment of mature landfill leachate. This reactor, combining microelectrolysis with Fenton process, revealed high treatment efficiency. The operating variables, including Fe-C dosage, H2O2 concentration and initial pH, were optimized by the response surface methodology (RSM), regarding the chemical oxygen demand (COD) removal efficiency and biochemical oxygen demand: chemical oxygen demand (BOD5/COD) as the responses. The highest COD removal (74.59%) and BOD5/COD (0.50) was obtained at optimal conditions of Fe-C dosage 55.72g/L, H2O2 concentration 12.32mL/L and initial pH 3.12. Three-dimensional excitation and emission matrix (3D-EEM) fluorescence spectroscopy and molecular weight (MW) distribution demonstrated that high molecular weight fractions such as refractory fulvic-like substances in leachate were effectively destroyed during the combined processes, which should be attributed to the combination oxidative effect of microelectrolysis and Fenton. The fixed-bed column experiments were performed and the breakthrough curves at different flow rates were evaluated to determine the practical applicability of the combined process. All these results show that the hydrogen peroxide-enhanced iron-carbon (Fe-C) microelectrolysis reactor is a promising and efficient technology for the treatment of mature landfill leachate. Copyright © 2016 Elsevier B.V. All rights reserved.

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

Iron and Immunity

NARCIS (Netherlands)

Verbon, E.H.|info:eu-repo/dai/nl/413534049; Trapet, P.L.; Stringlis, I.|info:eu-repo/dai/nl/41185206X; Kruijs, Sophie; Bakker, P.A.H.M.|info:eu-repo/dai/nl/074744623; Pieterse, C.M.J.|info:eu-repo/dai/nl/113115113

2017-01-01

Iron is an essential nutrient for most life on Earth because it functions as a crucial redox catalyst in many cellular processes. However, when present in excess iron can lead to the formation of harmful hydroxyl radicals. Hence, the cellular iron balance must be tightly controlled. Perturbation of

The temperature gradient on section of casting in process of primary crystallization of chromium cast iron

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A. Studnicki

2008-08-01

Full Text Available The methodology of defining in article was introduced the temperature gradient in process of primary crystallization during cooling the casting from chromium cast iron on basis of measurements of thermal field in test DTA-K3. Insert also the preliminary results of investigations of influence temperature gradient on structure of studied wear resistance chromium cast iron.

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

Extraction of Iron and Manganese from Pyrolusite Absorption Residue by Ammonium Sulphate Roasting–Leaching Process

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Lin Deng

2018-01-01

Full Text Available The residue from desulfurization and denitrification of exhaust gas treatment process with pyrolusite ore as absorbent is regarded as a potential source of iron and manganese. In this study, an extraction process is proposed for recovery of iron and manganese with ammonium sulphate roasting followed by sulphuric acid leaching. Firstly, the conversion mechanism was analyzed through mineral phase analysis of roasting products at different roasting temperature by means of X-ray diffraction (XRD technology. Then, the parameters of the roasting procedure such as roasting temperature and time, ammonium sulphate dosage, leaching temperature, leaching time, and sulphuric acid concentration are examined. The results implicate that the iron oxide and manganese dioxide in the residue are firstly converted into the water-soluble ( NH 4 3 Fe ( SO 4 3 and ( NH 4 2 Mn 2 ( SO 4 3 at 200–350 °C, and then the more stable NH 4 Fe ( SO 4 2 and MnSO 4 are formed, at temperature higher than 350 °C. Under optimum conditions, 95.2% Fe and 97.0% Mn can be extracted. Reactant diffusion through inert layer of silicon dioxide was considered as the rate-limiting step for iron extraction with an activation energy of 20.56 kJ/mol, while, the recovery process of Mn was controlled by both reactant diffusion and chemical reaction with an activation energy of 29.52 kJ/mol.

Theoretical and practical investigation into sustainable metal joining process for the automotive industry

International Nuclear Information System (INIS)

Al-Jader, M A; Cullen, J D; Shaw, Andy; Al-Shamma'a, A I

2011-01-01

Currently there are about 4300 weld points on the average steel vehicle. Errors and problems due to tip damage and wear can cause great losses due to production line downtime. Current industrial monitoring systems check the quality of the nugget after processing 15 cars average once every two weeks. The nuggets are examined off line using a destructive process, which takes approximately 10 days to complete causing a long delay in the production process. In this paper a simulation results using software package, SORPAS, will be presented to determined the sustainability factors in spot welding process including Voltage, Current, Force, Water cooling rates, Material thicknesses and usage. The experimental results of various spot welding processes will be investigated and reported. The correlation of experimental results shows that SORPAS simulations can be used as an off line measurement to reduce factory energy usage. This paper also provides an overview of electrode current selection and its variance over the lifetime of the electrode tip, and describes the proposed analysis system for the selection of welding parameters for the spot welding process, as the electrode tip wears.

The Effect Of Local Coal And Smelting Sponge Iron On Iron Content Of Pig Iron

Science.gov (United States)

Oediyani, Soesaptri; Juwita Sari, Pramita; Hadi P, Djoko

2018-03-01

The new regulation on mineral resources was announced by Ministry of Energy and Mineral resources (ESDM) of Indonesia at 2014 which it called Permen ESDM No 1/2014. Therefore, this research was conducted to add the value of local iron ores by using smelting technology. The objective of the research is to produce pig iron that meet the requirement of the new regulation of mineral resources such as 90% Fe. First, iron ores and coal mixed together with lime as a flux, then smelted in a Electric Arc Furnace at 1800°C. The process variables are (1; 1.25; 1.5; 1.75; 2.0) and the composition of coal (0.8%, 1.6%, 3.0%). The type of coal that used in this research was bituminous coal from Kalimantan and also the iron ores from Kalimantan. The products of the smelting technology are Pig iron and slag. Both pig iron and slag then analyzed by SEM-EDS to measure the iron content. The result shows that the maximum iron content on pig iron is about 95.04% meanwhile the minimum iron content on slag is about 3.66%. This result achieved at 1.6% coal and 2.0.

Oxygen blast furnace and combined cycle (OBF-CC) - an efficient iron-making and power generation process

International Nuclear Information System (INIS)

Jianwei, Y.; Guolong, S.; Cunjiang, K.; Tianjun, Y.

2003-01-01

A new iron and power generating process, oxygen blast furnace and combined cycle (OBF-CC), is presented. In order to support the opinion, the features of the oxygen blast furnace and integrated coal gasification and combined cycle (IGCC) are summarized. The relation between the blasting parameters and the output gas quantity, as well as caloric value is calculated based on mass and energy balance. Analysis and calculation indicate that the OBF-CC will be an efficient iron-making and power generation process with higher energy efficiency and less pollution

Quark nugget dark matter: no contradiction with 511 keV line emission from dwarf galaxies

Energy Technology Data Exchange (ETDEWEB)

Lawson, Kyle; Zhitnitsky, Ariel, E-mail: klawson@phas.ubc.ca, E-mail: arz@phas.ubc.ca [Department of Physics and Astronomy, University of British Columbia, Vancouver, B.C. V6T 1Z1 (Canada)

2017-02-01

The observed galactic 511 keV line has been interpreted in a number of papers as a possible signal of dark matter annihilation within the galactic bulge. If this is the case then it is possible that a similar spectral feature may be observed in association with nearby dwarf galaxies. These objects are believed to be strongly dark matter dominated and present a relatively clean observational target. Recently INTEGRAL observations have provided new constraints on the 511 keV flux from nearby dwarf galaxies [1] motivating further investigation into the mechanism by which this radiation may arise. In the model presented here dark matter in the form of heavy quark nuggets produces the galactic 511 keV emission line through interactions with the visible matter. It is argued that this type of interaction is not strongly constrained by the flux limits reported in [2].

Reactive oxygen species-related activities of nano-iron metal and nano-iron oxides.

Science.gov (United States)

Wu, Haohao; Yin, Jun-Jie; Wamer, Wayne G; Zeng, Mingyong; Lo, Y Martin

2014-03-01

Nano-iron metal and nano-iron oxides are among the most widely used engineered and naturally occurring nanostructures, and the increasing incidence of biological exposure to these nanostructures has raised concerns about their biotoxicity. Reactive oxygen species (ROS)-induced oxidative stress is one of the most accepted toxic mechanisms and, in the past decades, considerable efforts have been made to investigate the ROS-related activities of iron nanostructures. In this review, we summarize activities of nano-iron metal and nano-iron oxides in ROS-related redox processes, addressing in detail the known homogeneous and heterogeneous redox mechanisms involved in these processes, intrinsic ROS-related properties of iron nanostructures (chemical composition, particle size, and crystalline phase), and ROS-related bio-microenvironmental factors, including physiological pH and buffers, biogenic reducing agents, and other organic substances. Copyright © 2014. Published by Elsevier B.V.

Colour Metallography of Cast Iron - Chapter 3: Spheroidal Graphite Cast Iron (Ⅳ

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Zhou Jiyang

2010-11-01

Full Text Available Cast iron, as a traditional metal material, has advantages of low total cost, good castability and machinability, good wear resistance and low notch sensitivity, and is still facing tough challenge in quality, property and variety of types etc. Experts and engineers studying and producing iron castings all around world extremely concern this serious challenge. Over more than 30 years, a great of research work has been carried out on how to further improve its property, expand its application and combine cast iron technology with some hi-techs (for example, computer technology. Nevertheless, cast iron is a multi-element and multi-phase alloy and has complex and variety of structures and still has great development potential in structure and property. For further studying and developing cast iron, theoretical research work is important promise, and the study on solidification process and control mechanism of graphite morphology is fundamental for improving property of cast iron and developing new type of cast iron. Metallography of cast iron normally includes two sections: liquid phase transformation and solid phase transformation. The book, Colour Metallography of Cast Iron, uses colour metallography technique to study solidification structures of cast irons: graphite, carbides, austenite and eutectics; and focuses on solidification processes. With progress of modern solidification theory, the control of material solidification process becomes important measure for improving traditional materials and developing new materials. Solidification structure not only influences mechanical and physical properties of cast iron, but also affects its internal quality. The book uses a large amount of colour photos to describe the formation of solidification structures and their relations. Crystallization phenomena, which cannot be displayed with traditional metallography, are presented and more phase transformation information is obtained from these colour

Colour Metallography of Cast Iron - Chapter 3: Spheroidal Graphite Cast Iron (Ⅰ

Directory of Open Access Journals (Sweden)

Zhou Jiyang

2010-02-01

Full Text Available Cast iron, as a traditional metal material, has advantages of low total cost, good castability and machinability, good wear resistance and low notch sensitivity, and is still facing tough challenge in quality, property and variety of types etc. Experts and engineers studying and producing iron castings all around world extremely concern this serious challenge. Over more than 30 years, a great of research work has been carried out on how to further improve its property, expand its application and combine cast iron technology with some hi-techs (for example, computer technology. Nevertheless, cast iron is a multi-element and multi-phase alloy and has complex and variety of structures and still has great development potential in structure and property. For further studying and developing cast iron, theoretical research work is important promise, and the study on solidification process and control mechanism of graphite morphology is fundamental for improving property of cast iron and developing new type of cast iron. Metallography of cast iron normally includes two sections: liquid phase transformation and solid phase transformation. The book, Colour Metallography of Cast Iron, uses colour metallography technique to study solidification structures of cast irons: graphite, carbides, austenite and eutectics; and focuses on solidification processes. With progress of modern solidification theory, the control of material solidification process becomes important measure for improving traditional materials and developing new materials. Solidification structure not only influences mechanical and physical properties of cast iron, but also affects its internal quality. The book uses a large amount of colour photos to describe the formation of solidification structures and their relations. Crystallization phenomena, which cannot be displayed with traditional metallography, are presented and more phase transformation information is obtained from these colour

Colour Metallography of Cast Iron - Chapter 4: Vermicular Graphite Cast Iron (Ⅱ

Directory of Open Access Journals (Sweden)

Zhou Jiyang

2011-05-01

Full Text Available Cast iron, as a traditional metal material, has advantages of low total cost, good castability and machinability, good wear resistance and low notch sensitivity, and is still facing tough challenge in quality, property and variety of types etc. Experts and engineers studying and producing iron castings all around world extremely concern this serious challenge. Over more than 30 years, a great of research work has been carried out on how to further improve its property, expand its application and combine cast iron technology with some hi-techs (for example, computer technology. Nevertheless, cast iron is a multi-element and multi-phase alloy and has complex and variety of structures and still has great development potential in structure and property. For further studying and developing cast iron, theoretical research work is important promise, and the study on solidification process and control mechanism of graphite morphology is fundamental for improving property of cast iron and developing new type of cast iron. Metallography of cast iron normally includes two sections: liquid phase transformation and solid phase transformation. The book, Colour Metallography of Cast Iron, uses colour metallography technique to study solidification structures of cast irons: graphite, carbides, austenite and eutectics; and focuses on solidification processes. With progress of modern solidification theory, the control of material solidification process becomes important measure for improving traditional materials and developing new materials. Solidification structure not only influences mechanical and physical properties of cast iron, but also affects its internal quality. The book uses a large amount of colour photos to describe the formation of solidification structures and their relations. Crystallization phenomena, which cannot be displayed with traditional metallography, are presented and more phase transformation information is obtained from these colour

Insights into iron and nuclear factor-kappa B (NF-kappaB) involvement in chronic inflammatory processes in peritoneal endometriosis.

Science.gov (United States)

Defrère, Sylvie; González-Ramos, Reinaldo; Lousse, Jean-Christophe; Colette, Sébastien; Donnez, Olivier; Donnez, Jacques; Van Langendonckt, Anne

2011-08-01

Endometriosis is a chronic pelvic inflammatory process. Local inflammation is known to play a role in pain and infertility associated with the disease, and may be extensively involved in molecular and cellular processes leading to endometriosis development. In this review, we focus on two inflammatory mediators clearly implicated in the pathogenesis of endometriosis, iron and NF-kappaB, and their potential association. Iron is essential for all living organisms, but excess iron results in toxicity and is linked to pathological disorders. In endometriosis patients, iron overload has been demonstrated in the different compartments of the peritoneal cavity (peritoneal fluid, endometriotic lesions, peritoneum and macrophages). This iron overload affects numerous mechanisms involved in endometriosis development. Moreover, iron can generate free radical species able to react with a wide range of cellular constituents, inducing cellular damage. Overproduction of reactive oxygen species also impairs cellular function by altering gene expression via regulation of redox-sensitive transcription factors such as NF-kappaB, which is clearly implicated in endometriosis. Indeed, NF-kappaB is activated in endometriotic lesions and peritoneal macrophages of endometriosis patients, which stimulates synthesis of proinflammatory cytokines, generating a positive feedback loop in the NF-kappaB pathway. NF-kappaB-mediated gene transcription promotes a variety of processes, including endometriotic lesion establishment, maintenance and development. In conclusion, iron and NF-kappaB appear to be linked and both are clearly involved in endometriosis development, making these pathways an attractive target for future treatment and prevention of this disease.

Crystallography of refractory metal nuggets in carbonaceous chondrites: A transmission Kikuchi diffraction approach

Science.gov (United States)

Daly, Luke; Bland, Phil A.; Dyl, Kathryn A.; Forman, Lucy V.; Saxey, David W.; Reddy, Steven M.; Fougerouse, Denis; Rickard, William D. A.; Trimby, Patrick W.; Moody, Steve; Yang, Limei; Liu, Hongwei; Ringer, Simon P.; Saunders, Martin; Piazolo, Sandra

2017-11-01

Transmission Kikuchi diffraction (TKD) is a relatively new technique that is currently being developed for geological sample analysis. This technique utilises the transmission capabilities of a scanning electron microscope (SEM) to rapidly and accurately map the crystallographic and geochemical features of an electron transparent sample. TKD uses a similar methodology to traditional electron backscatter diffraction (EBSD), but is capable of achieving a much higher spatial resolution (5-10 nm) (Trimby, 2012; Trimby et al., 2014). Here we apply TKD to refractory metal nuggets (RMNs) which are micrometre to sub-micrometre metal alloys composed of highly siderophile elements (HSEs) found in primitive carbonaceous chondrite meteorites. TKD allows us to analyse RMNs in situ, enabling the characterisation of nanometre-scale variations in chemistry and crystallography, whilst preserving their spatial and crystallographic context. This provides a complete representation of each RMN, permitting detailed interpretation of their formation history. We present TKD analysis of five transmission electron microscopy (TEM) lamellae containing RMNs coupled with EBSD and TEM analyses. These analyses revealed textures and relationships not previously observed in RMNs. These textures indicate some RMNs experienced annealing, forming twins. Some RMNs also acted as nucleation centres, and formed immiscible metal-silicate fluids. In fact, each RMN analysed in this study had different crystallographic textures. These RMNs also had heterogeneous compositions, even between RMNs contained within the same inclusion, host phase and even separated by only a few nanometres. Some RMNs are also affected by secondary processes at low temperature causing exsolution of molybdenite. However, most RMNs had crystallographic textures indicating that the RMN formed prior to their host inclusion. TKD analyses reveal most RMNs have been affected by processing in the protoplanetary disk. Despite this

Simulation of a Sponge Iron Production Process

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Tor Onshus

1983-07-01

Full Text Available A model for reduction of FeO with hydrogen in a countercurrent moving bed reactor is summarized. This model is a special case of a mor ecomplete model which also includes reduction of the higher oxides, hematite and magnetite, with a mixture of reducing gases, thus describing the production of direct-reduced iron from iron ores. Equations governing the heat and mass transfer between the gas and solid phase are not given here, but play an important role in the dynamic bahviour of the model.

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

Compacted graphite iron: Cast iron makes a comeback

Science.gov (United States)

Dawson, S.

1994-08-01

Although compacted graphite iron has been known for more than four decades, the absence of a reliable mass-production technique has resulted in relatively little effort to exploit its operational benefits. However, a proven on-line process control technology developed by SinterCast allows for series production of complex components in high-quality CGI. The improved mechanical properties of compacted graphite iron relative to conventional gray iron allow for substantial weight reduction in gasoline and diesel engines or substantial increases in horsepower, or an optimal combination of both. Concurrent with these primary benefits, CGI also provides significant emissions and fuel efficiency benefits allowing automakers to meet legislated performance standards. The operational and environmental benefits of compacted graphite iron together with its low cost and recyclability reinforce cast iron as a prime engineering material for the future.

2-Chlorophenol Removal of Aqueous Solution Using Advanced Oxidation Processes Resulting from Iron/ Persulfate and Ultra Violet/ Persulfate

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Shokufeh Astereki

2016-06-01

Full Text Available Background: Advanced oxidation processes are used to remove toxic aromatic compounds with low biodegradability, such as 2-chlorophenol. This study investigated the use of sulfate (SO4- and persulfate (S2O82- radicals, as one of the advanced oxidation methods, to remove 2- chlorophenol from aquatic solutions. Methods: This experimental and pilot-scale study was carried out using two chemical batch reactors; one of the reactors equipped with UV lamps and the other was on the hot plate. In iron/ persulfate (Fe/S2O82- and ultra violet/ persulfate (UV/S2O82- processes different parameters were investigated. Results: Iron, UV, the initial pH of the solution, persulfate concentration have considerable effects on the elimination of 2-chlorophenol in both processes. In both processes, the maximum elimination occurred in acidic conditions. The elimination efficiency was increased by increasing the concentration of 2-chlorophenol and UV intensity, and also by decreasing the concentration of persulfate and iron. Accordingly, in iron/ persulfate and ultra violet/ persulfate processes 2-chlorophenol was eliminated with 99.96% and 99.58% efficiencies, respectively. Conclusion: Sulfate radicals produced from activated persulfate ions with hot-Fe ion and UV radiation have significant impact on the removal of 2-chlorophenol. Therefore, the processes of Fe/S2O82- and UV/S2O82- can be regarded as good choices for industrial wastewater treatment plants operators in the future.

Advanced landfill leachate treatment using iron-carbon microelectrolysis- Fenton process: Process optimization and column experiments

International Nuclear Information System (INIS)

Wang, Liqun; Yang, Qi; Wang, Dongbo; Li, Xiaoming; Zeng, Guangming; Li, Zhijun; Deng, Yongchao; Liu, Jun; Yi, Kaixin

2016-01-01

Highlights: • Fe-C microelectrolysis-Fenton process is proposed to pretreat landfill leachate. • Operating variables are optimized by response surface methodology (RSM). • 3D-EEMs and MW distribution explain the mechanism of enhanced biodegradability. • Fixed-bed column experiments are performed at different flow rates. - Abstract: A novel hydrogen peroxide-enhanced iron-carbon (Fe-C) microelectrolysis reactor was proposed for the pretreatment of mature landfill leachate. This reactor, combining microelectrolysis with Fenton process, revealed high treatment efficiency. The operating variables, including Fe-C dosage, H_2O_2 concentration and initial pH, were optimized by the response surface methodology (RSM), regarding the chemical oxygen demand (COD) removal efficiency and biochemical oxygen demand: chemical oxygen demand (BOD_5/COD) as the responses. The highest COD removal (74.59%) and BOD_5/COD (0.50) was obtained at optimal conditions of Fe-C dosage 55.72 g/L, H_2O_2 concentration 12.32 mL/L and initial pH 3.12. Three-dimensional excitation and emission matrix (3D-EEM) fluorescence spectroscopy and molecular weight (MW) distribution demonstrated that high molecular weight fractions such as refractory fulvic-like substances in leachate were effectively destroyed during the combined processes, which should be attributed to the combination oxidative effect of microelectrolysis and Fenton. The fixed-bed column experiments were performed and the breakthrough curves at different flow rates were evaluated to determine the practical applicability of the combined process. All these results show that the hydrogen peroxide-enhanced iron-carbon (Fe-C) microelectrolysis reactor is a promising and efficient technology for the treatment of mature landfill leachate.

Advanced landfill leachate treatment using iron-carbon microelectrolysis- Fenton process: Process optimization and column experiments

Energy Technology Data Exchange (ETDEWEB)

Wang, Liqun, E-mail: 691127317@qq.com [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082 (China); Yang, Qi, E-mail: yangqi@hnu.edu.cn [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082 (China); Wang, Dongbo [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082 (China); Li, Xiaoming, E-mail: xmli121x@hotmail.com [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082 (China); Zeng, Guangming; Li, Zhijun; Deng, Yongchao; Liu, Jun; Yi, Kaixin [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082 (China)

2016-11-15

Highlights: • Fe-C microelectrolysis-Fenton process is proposed to pretreat landfill leachate. • Operating variables are optimized by response surface methodology (RSM). • 3D-EEMs and MW distribution explain the mechanism of enhanced biodegradability. • Fixed-bed column experiments are performed at different flow rates. - Abstract: A novel hydrogen peroxide-enhanced iron-carbon (Fe-C) microelectrolysis reactor was proposed for the pretreatment of mature landfill leachate. This reactor, combining microelectrolysis with Fenton process, revealed high treatment efficiency. The operating variables, including Fe-C dosage, H{sub 2}O{sub 2} concentration and initial pH, were optimized by the response surface methodology (RSM), regarding the chemical oxygen demand (COD) removal efficiency and biochemical oxygen demand: chemical oxygen demand (BOD{sub 5}/COD) as the responses. The highest COD removal (74.59%) and BOD{sub 5}/COD (0.50) was obtained at optimal conditions of Fe-C dosage 55.72 g/L, H{sub 2}O{sub 2} concentration 12.32 mL/L and initial pH 3.12. Three-dimensional excitation and emission matrix (3D-EEM) fluorescence spectroscopy and molecular weight (MW) distribution demonstrated that high molecular weight fractions such as refractory fulvic-like substances in leachate were effectively destroyed during the combined processes, which should be attributed to the combination oxidative effect of microelectrolysis and Fenton. The fixed-bed column experiments were performed and the breakthrough curves at different flow rates were evaluated to determine the practical applicability of the combined process. All these results show that the hydrogen peroxide-enhanced iron-carbon (Fe-C) microelectrolysis reactor is a promising and efficient technology for the treatment of mature landfill leachate.

Bacterial Oxidation and Reduction of Iron in the Processes of Creation and Treatment of Acid Mining Waters

Directory of Open Access Journals (Sweden)

Daniel Kupka

2004-12-01

Full Text Available Acid mine drainages (AMDs arise at the weathering of sulphidic minerals. The occurrence of acidic streams is commonly associated with the human mining activities. Due to the disruption and excavation of sulphide deposits, the oxidation processes have initiated. Acidic products of sulphide oxidation accelerate the degradation of accompanying minerals. AMDs typically contain high concentrations of sulfuric acid and soluble metals and cause serious ecological problems due to the water pollution and the devastation of adjacent country. Microbial life in these extremely acidic environments may be considerably diverse. AMDs are abundant in bacteria capable to oxidize and/or to reduce iron. The rate of bacterial oxidation of ferrous iron released from pyrite surfaces is up to one million times faster than the chemical oxidation rate at low pH. Bacterial regeneration of ferric iron maintains the continuity of pyrite oxidation and the production of AMDs. Another group of microorganisms living in these environments are acidophilic ferric iron reducing bacteria. This group of microorganisms has been discovered only relatively recently. Acidophilic heterotrophic bacteria reduce ferric iron in either soluble or solid forms to ferrous iron. The reductive dissolution of ferric iron minerals brings about a mobilization of iron as well as associated heavy metals. The Bacterial oxidation and reduction of iron play an important role in the transformation of either crystalline or amorphous iron-containing minerals, including sulphides, oxides, hydroxysulfates, carbonates and silicates. This work discusses the role of acidophilic bacteria in the natural iron cycling and the genesis of acidic effluents. The possibilities of application of iron bacteria in the remediation of AMDs are also considered.

Temporary dietary iron restriction affects the process of thrombus resolution in a rat model of deep vein thrombosis.

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Makiko Oboshi

Full Text Available Deep vein thrombosis (DVT is a major cause of pulmonary thromboembolism and sudden death. Thus, it is important to consider the pathophysiology of DVT. Recently, iron has been reported to be associated with thrombotic diseases. Hence, in this study, we investigate the effects of dietary iron restriction on the process of thrombus resolution in a rat model of DVT.We induced DVT in 8-week-old male Sprague-Dawley rats by performing ligations of their inferior venae cavae. The rats were then given either a normal diet (DVT group or an iron-restricted diet (DVT+IR group. Thrombosed inferior venae cavae were harvested at 5 days after ligation.The iron-restricted diet reduced venous thrombus size compared to the normal diet. Intrathrombotic collagen content was diminished in the DVT+IR group compared to the DVT group. In addition, intrathrombotic gene expression and the activity of matrix metalloproteinase-9 were increased in the DVT+IR group compared to the DVT group. Furthermore, the DVT+IR group had greater intrathrombotic neovascularization as well as higher gene expression levels of urokinase-type plasminogen activator and tissue-type plasminogen activator than the DVT group. The iron-restricted diet decreased intrathrombotic superoxide production compared to the normal diet.These results suggest that dietary iron restriction affects the process of thrombus resolution in DVT.

Temporary dietary iron restriction affects the process of thrombus resolution in a rat model of deep vein thrombosis.

Science.gov (United States)

Oboshi, Makiko; Naito, Yoshiro; Sawada, Hisashi; Hirotani, Shinichi; Iwasaku, Toshihiro; Okuhara, Yoshitaka; Morisawa, Daisuke; Eguchi, Akiyo; Nishimura, Koichi; Fujii, Kenichi; Mano, Toshiaki; Ishihara, Masaharu; Masuyama, Tohru

2015-01-01

Deep vein thrombosis (DVT) is a major cause of pulmonary thromboembolism and sudden death. Thus, it is important to consider the pathophysiology of DVT. Recently, iron has been reported to be associated with thrombotic diseases. Hence, in this study, we investigate the effects of dietary iron restriction on the process of thrombus resolution in a rat model of DVT. We induced DVT in 8-week-old male Sprague-Dawley rats by performing ligations of their inferior venae cavae. The rats were then given either a normal diet (DVT group) or an iron-restricted diet (DVT+IR group). Thrombosed inferior venae cavae were harvested at 5 days after ligation. The iron-restricted diet reduced venous thrombus size compared to the normal diet. Intrathrombotic collagen content was diminished in the DVT+IR group compared to the DVT group. In addition, intrathrombotic gene expression and the activity of matrix metalloproteinase-9 were increased in the DVT+IR group compared to the DVT group. Furthermore, the DVT+IR group had greater intrathrombotic neovascularization as well as higher gene expression levels of urokinase-type plasminogen activator and tissue-type plasminogen activator than the DVT group. The iron-restricted diet decreased intrathrombotic superoxide production compared to the normal diet. These results suggest that dietary iron restriction affects the process of thrombus resolution in DVT.

The Iron Removal in Marmatite Concentrate Pressure Leaching Process

Science.gov (United States)

Wen-bo, LUO; Ji-kun, WANG; Yin, GAN

2018-01-01

To modify the pressure leaching technology of horizontal autoclave using marmatite concentrate, an appropriate increase in the pulp’s residence time in the horizontal autoclave is required. This increase will provide sufficient time for leaching to be completed in the first three chambers of the horizontal autoclave. Adding zinc oxide ore and potassium sulfate in the fourth chamber of the horizontal autoclave is needed to complete preliminary neutralization and iron precipitation in the horizontal autoclave. The pilot plant experimental results of the proposed technology are satisfactory, further shortening the process of pressure leaching and improving its economic efficiency.

Ironing out the Details: Exploring the Role of Iron and Heme in Blood-Sucking Arthropods

Science.gov (United States)

Whiten, Shavonn R.; Eggleston, Heather; Adelman, Zach N.

2018-01-01

Heme and iron are essential molecules for many physiological processes and yet have the ability to cause oxidative damage such as lipid peroxidation, protein degradation, and ultimately cell death if not controlled. Blood-sucking arthropods have evolved diverse methods to protect themselves against iron/heme-related damage, as the act of bloodfeeding itself is high risk, high reward process. Protective mechanisms in medically important arthropods include the midgut peritrophic matrix in mosquitoes, heme aggregation into the crystalline structure hemozoin in kissing bugs and hemosomes in ticks. Once heme and iron pass these protective mechanisms they are presumed to enter the midgut epithelial cells via membrane-bound transporters, though relatively few iron or heme transporters have been identified in bloodsucking arthropods. Upon iron entry into midgut epithelial cells, ferritin serves as the universal storage protein and transport for dietary iron in many organisms including arthropods. In addition to its role as a nutrient, heme is also an important signaling molecule in the midgut epithelial cells for many physiological processes including vitellogenesis. This review article will summarize recent advancements in heme/iron uptake, detoxification and exportation in bloodfeeding arthropods. While initial strides have been made at ironing out the role of dietary iron and heme in arthropods, much still remains to be discovered as these molecules may serve as novel targets for the control of many arthropod pests. PMID:29387018

Property and process correlations for iron-enriched basalt waste forms

International Nuclear Information System (INIS)

Grandy, J.D.; Eddy, T.L.; Anderson, G.L.

1993-02-01

Correlations of thermodynamic properties and process parameters of high-temperature slag for a range of compositions of iron-enriched basalt are presented. The quantification of the properties of this complex mixture can assist in the design and monitoring of high-temperature melting systems for the treatment of radioactive and hazardous wastes at the Idaho National Engineering Laboratory. The buried and stored wastes at the INEL Radioactive Waste Management Complex have a similar composition to iron-enriched basalt after oxidation of organics. The properties correlated are the viscosity, electrical conductivity, refractory corrosion, and recrystallization temperature. The correlations are expressed as a function of input waste-soil mixture composition, alkali concentration, and slag temperature. An application to determine the effect of alkali flux on slag temperature, leach rate, and volume reduction is presented. Though the correlations are for mixtures of soil and waste with average transuranic-contaminated waste compositions, it appears that good approximations for other waste streams and glass-ceramic waste forms can be obtained because of similarities in composition

Crystallization process and magnetic properties of amorphous iron oxide nanoparticles

International Nuclear Information System (INIS)

Phu, N D; Luong, N H; Chau, N; Hai, N H; Ngo, D T; Hoang, L H

2011-01-01

This paper studied the crystallization process, phase transition and magnetic properties of amorphous iron oxide nanoparticles prepared by the microwave heating technique. Thermal analysis and magnetodynamics studies revealed many interesting aspects of the amorphous iron oxide nanoparticles. The as-prepared sample was amorphous. Crystallization of the maghemite γ-Fe 2 O 3 (with an activation energy of 0.71 eV) and the hematite α-Fe 2 O 3 (with an activation energy of 0.97 eV) phase occurred at around 300 deg. C and 350 deg. C, respectively. A transition from the maghemite to the hematite occurred at 500 deg. C with an activation energy of 1.32 eV. A study of the temperature dependence of magnetization supported the crystallization and the phase transformation. Raman shift at 660 cm -1 and absorption band in the infrared spectra at 690 cm -1 showed the presence of disorder in the hematite phase on the nanoscale which is supposed to be the origin of the ferromagnetic behaviour of that antiferromagnetic phase.

Binary stars as sources of iron and of s-process isotopes

International Nuclear Information System (INIS)

Iben, Icko Jr.; Bologna Univ.; Sussex Univ., Brighton

1986-01-01

Sources of elements and isotopes in stars, during the development of stars, is examined. The paper was presented to the conference on ''The early universe and its evolution'', Erice, Italy, 1986. Intermediate mass stars in their asymptotic giant branch phase of evolution as sources of carbon, merging white dwarfs as sources of iron, and helium star cataclysmics as sources of s-process elements, are all discussed. (U.K.)

BOWIEITE: A NEW RHODIUM-IRIDIUM-PLATINUM SULFIDE IN PLATINUM-ALLOY NUGGETS, GOODNEWS BAY, ALASKA.

Science.gov (United States)

Desborough, George A.; Criddle, Alan J.

1984-01-01

Bowieite (Rh,Ir,Pt)//2S//3, a new mineral species, is found in three nuggets of platinum from Goodnews Bay, Alaska. In linearly polarized reflected light, and compared to the host, higher reflecting white platinum-iridium alloy, bowieite is pale gray to pale gray-brown; neither bireflectance nor reflectance pleochroism is apparent. With polars crossed, its anisotropic rotation tints vary from gray to dark brown. Luminance values (relative to the CIE illuminant C) for R//1 and R//2, computed from full spectral data for the most bireflectant grain, are 45. 8% and 48. 2% in air, and 30. 5% and 33. 0% in oil, respectively. VHN//1//0//0 1288 (858 to 1635). Bowieite is orthorhombic, space group Pnca, with a 8. 454(7) -8. 473(8), b 5. 995(1)-6. 002(7), c 6. 143(1)-6. 121(8) A, Z equals 4. Some grains that are 2. 6 to 3. 8 atomic % metal-deficient occur as an optically coherent rim on bowieite; the rim and the bowieite grain are not optically continuous.

Ethylene, Enzymatic and Respiratory Pattern Evolution in Loquat (Eriobotrya japonica (Thunb. Lindl. cv. Golden Nugget in the Last four Sequential Stages of Maturation Evolución del Patrón Respiratorio, Enzimático y de Etileno del Níspero Japonés (Eriobotrya japonica (Thunb. Lindl. cv. Golden Nugget en los Últimos Cuatro Estadios Secuenciales de Madurez

Directory of Open Access Journals (Sweden)

Pedro L Undurraga M

2011-12-01

Full Text Available There is some controversy regarding the respiratory pattern of loquat (Eriobotrya japonica [Thunb.] Lindl.. Thus in order to provide information on this aspect of loquat, fruit of 50-70 g, from cv. Golden Nugget were harvested in four stages of maturity: green (BBCH 709, color break (BBCH 801, yellow (BBCH 807, and orange (BBCH 809. The parameters evaluated in each stage were: soluble solids, titratable acidity, respiration, ethylene generation, and activity of the enzymes pectin methyl esterase (PME, peroxidase, polyphenoloxidase (PPO, polygalacturonase (PG, and cellulose, and the soluble solids:acidity ratio was calculated. The results show that ethylene concentration increased at the time of color break, which was not the case for the change in the respiratory rate. The activity of the peroxidase enzyme increased from the green stage to color break, while the enzymes PME, cellulase, and PG showed a constant reduction from the green to the orange stage, and PPO showed no change over the four stages studied. With regards to quality, from color break onwards soluble solids increased to 11.8 °Brix and titratable acidity dropped from 0.67 to 0.28 g L-1 malic acid. Based on these results, the conclusion is that towards the end of its development loquat cv. Golden Nugget evidence enzymatic and ethylene behavior similar to that of climacteric fruits.Existe controversia sobre el patrón respiratorio del níspero (Eriobotrya japonica [Thunb.] Lindl.. Con el fin de aportar información sobre este aspecto, frutos del cv. Golden Nugget entre 50-70 g, fueron cosechados en cuatro estadios de madurez; verde (BBCH 709, quiebre de color (BBCH 801, amarillo (BBCH 807, y anaranjado (BBCH 809. Los parámetros evaluados en cada estadio fueron: sólidos solubles, acidez titulable, relación sólidos solubles acidez, respiración, generación de etileno y la actividad de las enzimas pectin metil esterasa (PME, peroxidasa, polifenoloxidasa (PPO, poligalacturonasa

Sensitivity of Austempering Heat Treatment of Ductile Irons to Changes in Process Parameters

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Boccardo, A. D.; Dardati, P. M.; Godoy, L. A.; Celentano, D. J.

2018-03-01

Austempered ductile iron (ADI) is frequently obtained by means of a three-step austempering heat treatment. The parameters of this process play a crucial role on the microstructure of the final product. This paper considers the influence of some process parameters (i.e., the initial microstructure of ductile iron and the thermal cycle) on key features of the heat treatment (such as minimum required time for austenitization and austempering and microstructure of the final product). A computational simulation of the austempering heat treatment is reported in this work, which accounts for a coupled thermo-metallurgical behavior in terms of the evolution of temperature at the scale of the part being investigated (the macroscale) and the evolution of phases at the scale of microconstituents (the microscale). The paper focuses on the sensitivity of the process by looking at a sensitivity index and scatter plots. The sensitivity indices are determined by using a technique based on the variance of the output. The results of this study indicate that both the initial microstructure and the thermal cycle parameters play a key role in the production of ADI. This work also provides a guideline to help selecting values of the appropriate process parameters to obtain parts with a required microstructural characteristic.

Sensitivity of Austempering Heat Treatment of Ductile Irons to Changes in Process Parameters

Science.gov (United States)

Boccardo, A. D.; Dardati, P. M.; Godoy, L. A.; Celentano, D. J.

2018-06-01

Austempered ductile iron (ADI) is frequently obtained by means of a three-step austempering heat treatment. The parameters of this process play a crucial role on the microstructure of the final product. This paper considers the influence of some process parameters ( i.e., the initial microstructure of ductile iron and the thermal cycle) on key features of the heat treatment (such as minimum required time for austenitization and austempering and microstructure of the final product). A computational simulation of the austempering heat treatment is reported in this work, which accounts for a coupled thermo-metallurgical behavior in terms of the evolution of temperature at the scale of the part being investigated (the macroscale) and the evolution of phases at the scale of microconstituents (the microscale). The paper focuses on the sensitivity of the process by looking at a sensitivity index and scatter plots. The sensitivity indices are determined by using a technique based on the variance of the output. The results of this study indicate that both the initial microstructure and the thermal cycle parameters play a key role in the production of ADI. This work also provides a guideline to help selecting values of the appropriate process parameters to obtain parts with a required microstructural characteristic.

BIOINSPIRED DESIGN AND DIRECTED EVOLUTION OF IRON CONTAINING ENZYMES FOR GREENSYNTHETIC PROCESSES AND BIOREMEDIATION

Science.gov (United States)

SU833912Title: Bioinspired Design and Directed Evolution of Iron Containing Enzymes for Green Synthetic Processes and BioremediationEdward I. Solomon, Shaun D. Wong, Lei Liu, Caleb B. Bell, IIICynthia Nolt-HelmsProject Period: August 15, 2008 - August 14,...

Energy efficiency opportunities in the production process of cast iron foundries: An experience in Italy

International Nuclear Information System (INIS)

Lazzarin, Renato M.; Noro, Marco

2015-01-01

Foundry sector is one of the most energy intensive in industry. Energy audits performed in 5 Italian cast iron foundries allowed to identify energy utilization in the various processes that from the melting of the iron arrive at the finishing of the casting. Main equipment was surveyed, evaluating the influence on the overall energy consumption, producing a detailed analysis of energy use per department and energy performance indexes. A separate study was carried out for foundries with induction furnaces and cold or hot blast cupolas. Possibilities of heat recovery was identified particularly in combustion air preheating, but also for building heating or to power direct cycles to produce electricity. Better insulation and new insulating materials can improve the efficiency and the quality of the processes. Suggestions are supplied in the various foundry departments for energy saving. Possible energy saving actions on the service plants will be dealt with in a separate paper. - Highlights: • The Authors performed energy audits in 5 Italian cast iron foundries. • Main equipment was surveyed, evaluating the influence on the overall energy consumption. • An analysis of energy use per department and energy performance indexes was performed. • Possibilities of heat recovery were identified in combustion air preheating and for building heating. • Better and new insulating materials were analyzed to improve the efficiency and process quality.

Pyrimethanil degradation by photo-Fenton process: Influence of iron and irradiance level on treatment cost.

Science.gov (United States)

Cabrera Reina, A; Miralles-Cuevas, S; Casas López, J L; Sánchez Pérez, J A

2017-12-15

This study evaluates the combined effect of photo-catalyst concentration and irradiance level on photo-Fenton efficiency when this treatment is applied to industrial wastewater decontamination. Three levels of irradiance (18, 32 and 46W/m 2 ) and three iron concentrations (8, 20 and 32mg/L) were selected and their influence over the process studied using a raceway pond reactor placed inside a solar box. For 8mg/L, it was found that there was a lack of catalyst to make use of all the available photons. For 20mg/L, the treatment always improved with irradiance indicating that the process was photo-limited. For 32mg/L, the excess of iron caused an excess of radicals production which proved to be counter-productive for the overall process efficiency. The economic assessment showed that acquisition and maintenance costs represent the lowest relative values. The highest cost was found to be the cost of the reagents consumed. Both sulfuric acid and sodium hydroxide are negligible in terms of costs. Iron cost percentages were also very low and never higher than 10.5% while the highest cost was always that of hydrogen peroxide, representing at least 85% of the reagent costs. Thus, the total costs were between 0.76 and 1.39€/m 3 . Copyright © 2017 Elsevier B.V. All rights reserved.

Integrated pyrolucite fluidized bed-membrane hybrid process for improved iron and manganese control in drinking water.

Science.gov (United States)

Dashtban Kenari, Seyedeh Laleh; Barbeau, Benoit

2017-04-15

Newly developed ceramic membrane technologies offer numerous advantages over the conventional polymeric membranes. This work proposes a new configuration, an integrated pyrolucite fluidized bed (PFB)-ceramic MF/UF hybrid process, for improved iron and manganese control in drinking water. A pilot-scale study was undertaken to evaluate the performance of this process with respect to iron and manganese control as well as membrane fouling. In addition, the fouling of commercially available ceramic membranes in conventional preoxidation-MF/UF process was compared with the hybrid process configuration. In this regard, a series of experiments were conducted under different influent water quality and operating conditions. Fouling mechanisms and reversibility were analyzed using blocking law and resistance-in-series models. The results evidenced that the flux rate and the concentration of calcium and humic acids in the feed water have a substantial impact on the filtration behavior of both membranes. The model for constant flux compressible cake formation well described the rise in transmembrane pressure. The compressibility of the filter cake substantially increased in the presence of 2 mg/L humic acids. The presence of calcium ions caused significant aggregation of manganese dioxide and humic acid which severely impacted the extent of membrane fouling. The PFB pretreatment properly alleviated membrane fouling by removing more than 75% and 95% of iron and manganese, respectively. Copyright © 2017 Elsevier Ltd. All rights reserved.

Assessment of polyphase sintered iron-cobalt-iron boride cermets

International Nuclear Information System (INIS)

Nowacki, J.; Pieczonka, T.

2004-01-01

Sintering of iron, cobalt and boron powders has been analysed. As a result iron-iron boride, Fe-Fe 2 B and iron/cobalt boride with a slight admixture of molybdenum, Fe - Co - (FeMoCo) 2 B cermets have been produced. Iron was introduced to the mixture as the Astalloy Mo Hoeganaes grade powder. Elemental amorphous boron powder was used, and formation of borides occurred both during heating and isothermal sintering periods causing dimensional changes of the sintered body. Dilatometry was chosen to control basic phenomena taking place during multiphase sintering of investigated systems. The microstructure and phase constituents of sintered compacts were controlled as well. The cermets produced were substituted to: metallographic tests, X-ray analysis, measurements of hardness and of microhardness, and of wear in the process of sliding dry friction. Cermets are made up of two phases; hard grains of iron - cobalt boride, (FeCo) 2 B (1800 HV) constituting the reinforcement and a relatively soft and plastic eutectic mixture Fe 2 B - Co (400-500 HV) constituting the matrix. (author)

In vitro evaluation of iron solubility and dialyzability of various iron fortificants and of iron-fortified milk products targeted for infants and toddlers.

Science.gov (United States)

Kapsokefalou, Maria; Alexandropoulou, Isidora; Komaitis, Michail; Politis, Ioannis

2005-06-01

The objectives of the present study were: to compare the solubility and dialyzability of various iron fortificants (iron pyrophosphate, ferrous bis-glycinate, ferrous gluconate, ferrous lactate, ferrous sulfate) added, in the presence of ascorbic acid, to pasteurized milk samples produced under laboratory conditions; and to compare the solubility and dialyzability of iron in commercial pasteurized, UHT and condensed milk products available in the Greek market fortified with various vitamins and minerals including iron and targeted towards infants (6-12 months old) and toddlers. Iron solubility and dialyzability were determined using a simulated gastrointestinal digestive system. Ferrous dialyzable iron (molecular weight lower than 8000) was used as an index for prediction of iron bioavailability. Ferrous dialyzable iron in pasteurized milk samples fortified with iron pyrophosphate, ferrous lactate and ferrous bis-glycinate was higher (P iron in products fortified with ferrous lactate was not different (P > 0.05) from those fortified with ferrous sulfate. Ferrous dialyzable iron in four condensed commercial milk products was higher (P iron was higher (P iron source, milk processing and the overall product composition affect formation of ferrous dialyzable iron and may determine the success and effectiveness of iron fortification of milk.

Placental iron uptake and its regulation

NARCIS (Netherlands)

M. Bierings (Marc)

1989-01-01

textabstractIron transport in pregnancy is an active one-way process, from mother to fetus. Early in gestation fetal iron needs are low, and so is trans-placental transport, but as erythropoiesis develops, rising fetal iron needs are met by trans-placental iron transport. Apparently, the fetus

Colour Metallography of Cast Iron

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Zhou Jiyang

2009-05-01

Full Text Available Cast iron, as a traditional metal material, has advantages of low total cost, good castability and machinability, good wear resistance and low notch sensitivity, and is still facing tough challenge in quality, property and variety of types etc. Experts and engineers studying and producing iron castings all around world extremely concern this serious challenge. Over more than 30 years, a great of research work has been carried out on how to further improve its property, expand its application and combine cast iron technology with some hi-techs (for example, computer technology. Nevertheless, cast iron is a multi-element and multi-phase alloy and has complex and variety of structures and still has great development potential in structure and property. For further studying and developing cast iron, theoretical research work is important promise, and the study on solidification process and control mechanism of graphite morphology is fundamental for improving property of cast iron and developing new type of cast iron.Metallography of cast iron normally includes two sections: liquid phase transformation and solid phase transformation. The book, Colour Metallography of Cast Iron , uses colour metallography technique to study solidification structures of cast irons: graphite, carbides, austenite and eutectics; and focuses on solidification processes. With progress of modern solidification theory, the control of material solidification process becomes important measure for improving traditionalmaterials and developing new materials. Solidification structure not only influences mechanical and physical properties of cast iron, but also affects its internal quality. The book uses a large amount of colour photos to describe the formation of solidification structures and their relations. Crystallization phenomena, which cannot be displayed with traditional metallography, are presented and more phase transformation information is obtained from these colour

Recovery of Iron from Pyrolusite Leaching Slag by a Lab-Scale Circulation Process of Oxalic Acid Leaching and Ultraviolet Irradiation

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Biao Deng

2017-12-01

Full Text Available Pyrolusite leaching slag is a Fe-containing slag generated from pyrolusite leaching process with SO2. Recovery of iron from the slag not only has economic benefit, but also prevents the secondary pollution to the environment. A novel lab-scale cyclic process for recovering iron from pyrolusite leaching slag was introduced. The process contains two steps: (1 iron was leached with oxalic acid and [Fe(C2O4n](3−2n+ solution was generated; (2 the [Fe(C2O4n](3−2n+ solution was irradiated by ultraviolet and ferrous oxalate precipitation were obtained. The effect of operation parameter on leaching and irradiation process were studied separately. In the leaching process, the optimal solid/liquid ratio, oxalic acid concentration, leaching temperature, stirring rate, and leaching time are 1:50, 0.40 mol/L, 95 °C, 300 r/min, and 3 h, respectively. In the irradiation process, the best irradiation wavelength, Fe/oxalic acid molar ratio and irradiation time are 254 nm, 1:4, and 30 min. Besides, a test of 9 continuous cycles was carried out and the performance and material balance of the combined process were investigated. The results showed that the cyclic process is entirely feasible and prove to be stable producing, and ferrous oxalate of 99.32% purity. Material balance indicated that 95.17% of iron was recovered in the form of FeC2O4·2H2O, and the recovery efficiency of oxalic acid was 58.52%.

Formation of iron nanoparticles and increase in iron reactivity in mineral dust during simulated cloud processing.

Science.gov (United States)

Shi, Zongbo; Krom, Michael D; Bonneville, Steeve; Baker, Alex R; Jickells, Timothy D; Benning, Liane G

2009-09-01

The formation of iron (Fe) nanoperticles and increase in Fe reactivity in mineral dust during simulated cloud processing was investigated using high-resolution microscopy and chemical extraction methods. Cloud processing of dust was experimentally simulated via an alternation of acidic (pH 2) and circumneutral conditions (pH 5-6) over periods of 24 h each on presieved (formation of Fe-rich nanoparticle aggregates, which were not found initially. Similar Fe-rich nanoparticles were also observed in wet-deposited Saharen dusts from the western Mediterranean but not in dry-deposited dust from the eastern Mediterranean. Sequential Fe extraction of the soil samples indicated an increase in the proportion of chemically reactive Fe extractable by an ascorbate solution after simulated cloud processing. In addition, the sequential extractions on the Mediterranean dust samples revealed a higher content of reactive Fe in the wet-deposited dust compared to that of the dry-deposited dust These results suggestthat large variations of pH commonly reported in aerosol and cloud waters can trigger neo-formation of nanosize Fe particles and an increase in Fe reactivity in the dust

Treatment of landfill leachate by a combined process: Iron electrodissolution, iron oxidation by H2O2 and chemical flocculation

Directory of Open Access Journals (Sweden)

Dayana Donneys-Victoria

2018-01-01

Full Text Available The efficiency of iron electrodissolution and the flocculation processes with Fe2+ and Fe3+ for removing color, turbidity, chloride and chemical oxygen demand (COD were studied by treating a landfill leachate effluent from “El Carrasco” (Bucaramanga, Colombia. The pH and current density for the electrodissolution treatment were determined from potentiodynamic polarization studies. The electrodissolution process was performed under galvanostatic conditions at 24 A m−2 with changing polarity of the electrodes. Hydrogen peroxide was used for the oxidation of Fe2+ to Fe3+ while Ca(OH2 was used for the flocculation as the pH modifier and coagulant adjuvant agent along with an anionic polyacrylamide. The results showed that higher removal efficiencies of the COD, color and turbidity were obtained (85, 96 and 76%, respectively using 0.225 g L−1 of hydrogen peroxide at pH about 8.5 after 150 min; requiring 0.6 kWh m−3 and a total treatment cost of 2.24 USD m−3. Keywords: Leachate, Iron electrodissolution, Potentiodynamic polarization, Flocculation

Co-processing of lignite-plastic mixtures into liquid distillate fractions in the presence of iron catalysts

Energy Technology Data Exchange (ETDEWEB)

Kuznetsov, B.N.; Sharypov, V.I.; Beregovtsova, N.G.; Baryshnikov, S.V.; Doroginskaya, A.N. [Russian Academy of Sciences, Krasnoyarsk (Russian Federation). Inst. of Chemistry of Natural Organic Materials Sibirian Branch

1997-12-31

Some features of co-processing of Kansk-Achinsk lignite with plastics into hydrocarbon mixtures in the presence of activated iron-containing minerals (hematite, magnetite, pyrrhotite) were investigated under various operating parameters. The following catalytic processes were studied: pyrolysis in an inert atmosphere, hydropyrolysis and water-steam cracking. (orig.)

An iron/amine-catalyzed cascade process for the enantioselective functionalization of allylic alcohols.

Science.gov (United States)

Quintard, Adrien; Constantieux, Thierry; Rodriguez, Jean

2013-12-02

Three is a lucky number: An enantioselective transformation of allylic alcohols into β-chiral saturated alcohols has been developed by combining two distinct metal- and organocatalyzed catalytic cycles. This waste-free triple cascade process merges an iron-catalyzed borrowing-hydrogen step with an aminocatalyzed nucleophilic addition reaction. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effective sulfur and energy recovery from hydrogen sulfide through incorporating an air-cathode fuel cell into chelated-iron process.

Science.gov (United States)

Sun, Min; Song, Wei; Zhai, Lin-Feng; Cui, Yu-Zhi

2013-12-15

The chelated-iron process is among the most promising techniques for the hydrogen sulfide (H2S) removal due to its double advantage of waste minimization and resource recovery. However, this technology has encountered the problem of chelate degradation which made it difficult to ensure reliable and economical operation. This work aims to develop a novel fuel-cell-assisted chelated-iron process which employs an air-cathode fuel cell for the catalyst regeneration. By using such a process, sulfur and electricity were effectively recovered from H2S and the problem of chelate degradation was well controlled. Experiment on a synthetic sulfide solution showed the fuel-cell-assisted chelated-iron process could maintain high sulfur recovery efficiencies generally above 90.0%. The EDTA was preferable to NTA as the chelating agent for electricity generation, given the Coulombic efficiencies (CEs) of 17.8 ± 0.5% to 75.1 ± 0.5% for the EDTA-chelated process versus 9.6 ± 0.8% to 51.1 ± 2.7% for the NTA-chelated process in the pH range of 4.0-10.0. The Fe (III)/S(2-) ratio exhibited notable influence on the electricity generation, with the CEs improved by more than 25% as the Fe (III)/S(2-) molar ratio increased from 2.5:1 to 3.5:1. Application of this novel process in treating a H2S-containing biogas stream achieved 99% of H2S removal efficiency, 78% of sulfur recovery efficiency, and 78.6% of energy recovery efficiency, suggesting the fuel-cell-assisted chelated-iron process was effective to remove the H2S from gas streams with favorable sulfur and energy recovery efficiencies. Copyright © 2013 Elsevier B.V. All rights reserved.

Direct Iron Coating onto Nd-Fe-B Powder by Thermal Decomposition of Iron Pentacarbonyl

International Nuclear Information System (INIS)

Yamamuro, S; Okano, M; Tanaka, T; Sumiyama, K; Nozawa, N; Nishiuchi, T; Hirosawa, S; Ohkubo, T

2011-01-01

Iron-coated Nd-Fe-B composite powder was prepared by thermal decomposition of iron pentacarbonyl in an inert organic solvent in the presence of alkylamine. Though this method is based on a modified solution-phase process to synthesize highly size-controlled iron nanoparticles, it is in turn featured by a suppressed formation of iron nanoparticles to achieve an efficient iron coating solely onto the surfaces of rare-earth magnet powder. The Nd-Fe-B magnetic powder was successfully coated by iron shells whose thicknesses were of the order of submicrometer to micrometer, being tuneable by the amount of initially loaded iron pentacarbonyl in a reaction flask. The amount of the coated iron reached to more than 10 wt.% of the initial Nd-Fe-B magnetic powder, which is practically sufficient to fabricate Nd-Fe-B/α-Fe nanocomposite permanent magnets.

Subsurface aeration of anaerobic groundwater : iron colloid formation and the nitrification process

NARCIS (Netherlands)

Wolthoorn, A.

2003-01-01

Keywords: Iron, anaerobic groundwater, groundwater purification, heterogeneous oxidation, iron colloid formation, electron microscopy, nitrification In anaerobic groundwater iron and ammonium can be found in relatively high concentrations. These substances need to be removed when groundwater is used

Humic Acid Removal from Aqueous Environments by Electrocoagulation Process Using Iron Electrodes

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Edris Bazrafshan

2012-01-01

Full Text Available At present study the performance of electrocoagulation process using iron electrodes sacrificial anode has been investigated for removal of HA from artificial aqueous solution. The experiments were performed in a bipolar batch reactor with four iron electrode connected in parallel. Several working parameters, such as initial pH (3, 5, 7, and 9, electrical conductivity (50 V and reaction time were studied in an attempt to achieve the highest removal capacity. Solutions of HA with concentration equal 20 mg L-1 were prepared. To follow the progress of the treatment, samples of 10 ml were taken at 15, 30, 45, 60, and 75 min interval. Finally HA concentration was measured by UV absorbance at 254 nm (UV254 and TOC concentration was measured by TOC Analyser. The maximum efficiency of HA removal which was obtained in voltage of 50 V, reaction time of 75 min, initial concentration 20 mg L-1, conductivity 3000 µS/Cm and pH 5, is equal to 92.69%. But for natural water samples at the same optimum condition removal efficiency was low (68.8 %. It can be concluded that the electrocoagulation process has the potential to be utilized for cost-effective removal of HA from aqueous environments.

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.

One step paired electrochemical synthesis of iron and iron oxide nanoparticles

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Ordoukhanian Juliet

2016-09-01

Full Text Available In this study, a new one step paired electrochemical method is developed for simultaneous synthesis of iron and iron oxide nanoparticles. iron and iron oxide are prepared as cathodic and anodic products from iron (ii sulfate aqueous solution in a membrane divided electrolytic cell by the pulsed current electrosynthesis. Because of organic solvent-free and electrochemical nature of the synthesis, the process could be considered as green and environmentally friendly. The reduction of energy consumption and low cost are the other significant advantages of this new method that would have a great application potential in the chemical industry. The nanostructure of prepared samples was characterized by Fourier transform infrared spectroscopy (FT-IR, X-ray diffraction (XRD, scanning electron microscopy (SEM and transmission electron microscopy (TEM. The magnetic properties were studied by vibrating sample magnetometer (VsM.

Solubility limit and precipitation kinetics of iron-phosphide in ferritic iron

International Nuclear Information System (INIS)

Suzuki, Shigeru

1992-01-01

The solubility limit of iron-phosphide in ferritic iron was examined with electrical resistivity measurements by using the relationship between resistivity and the amount of dissolved phosphorous. The temperature dependence of the solubility obtained was in good agreement with previous results. The kinetics of precipitation of the phosphide from a supersaturated Fe-3.75 at.% P alloy was also investigated with changes of the resistivity by isochronal and isothermal annealing. The activation energy for the precipitation process of the phosphide was about 2.6 eV. Diffusivities of phosphorus were estimated from the annealing behaviour and the morphology of the precipitates, which were comparable to those obtained with the tracer method previously. This suggests that the precipitation process of phosphide is rate controlled by diffusion of phosphorus in ferritic iron-phosphorus alloys. (orig.) [de

Pilot scale evaluation of biological and pressure clarification processes for the removal of high level of iron and manganese

Energy Technology Data Exchange (ETDEWEB)

Yannoni, C.C.; Kinsley, B.P. [Fay, Spofford & Thorndike, Inc., Burlington, MA (United States); Marston, T.R. [Connecticut Water Company, Clinton, CT (United States)

1996-11-01

Iron and manganese originating from groundwater supplies have a long history of causing consumer complaints in water distribution systems. Although iron and manganese are not public health concerns, they are a major concern from an aesthetic standpoint. The elevated awareness of consumers in regard to the quality of drinking water, an increase in regulations requiring additional treatment and the cost associated with developing new sources of supply, has required many utilities to implement improvements to existing facilities. Historical water quality data collected from the Connecticut Water Company`s (CWC) Westbrook Well revealed an increasing trend in iron and manganese concentrations. As a result, the existing greensand filtration facility located at the well, provides insufficient removal rates and inefficient operating cycles. Variations in operating procedures were not successful in correcting these problems. A water treatment feasibility study recommended evaluation of biological and pressure clarification processes to reduce iron (9 mg/l) and manganese (1.5 mg/l) levels below the secondary maximum contaminant levels of 0.30 and 0.05 mg/l, respectively. Assessment of these processes was accomplished through the construction and operation of a 5 gallon per minute (gpm) capacity pilot plant at the Westbrook Water Treatment Plant. Application of biological treatment for iron removal was then piloted on the existing full-scale treatment facility.

Process for iron separation from an organic solution containing uranium

International Nuclear Information System (INIS)

Textoris, A.; Lyaudet, G.; Bathelier, A.

1987-01-01

Iron is separated from an organic solution of U and Fe in a phosphine oxide and an acid organic phosphorus compound by reaction on oxalic acid or a mixture of sulfuric and phosphoric acid or phosphoric acid. Uranium stays in the initial organic solution and iron is transferred to the aqueous phase [fr

The technical processes of quarrying in the Late Iron Age of Western Iberia

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Jesús RODRÍGUEZ HERNÁNDEZ

2013-01-01

Full Text Available This paper reconstructs the technical processes involved in producing the stone works made by the communities of Western Iberia during the Late Iron Age. For this study, we use both archaeological and ethnographic data. We analyze the characteristics of granite, the extraction process in the quarry, the available means of transport, the tools used and the carving process, focusing analysis on the zoomorphic sculptures known as “verracos”. Assessment of these technical aspects is essential for the analysis of the finished products and constitutes a first step in better understanding the status of stonemasons within the protohistoric societies of the Western Iberian Peninsula.

Reduction of chromate from electroplating wastewater from pH 1 to 2 using fluidized zero valent iron process

International Nuclear Information System (INIS)

Chen, S.-S.; Cheng, C.-Y.; Li, C.-W.; Chai, P.-H.; Chang, Y.-M.

2007-01-01

Fluidized zero valent iron (ZVI) process was conducted to reduce hexavalent chromium (chromate, CrO 4 2- ) to trivalent chromium (Cr 3+ ) from electroplating wastewater due to the following reasons: (1) Extremely low pH (1-2) for the electroplating wastewater favoring the ZVI reaction. (2) The ferric ion, produced from the reaction of Cr(VI) and ZVI, can act as a coagulant to assist the precipitation of Cr(OH) 3(s) to save the coagulant cost. (3) Higher ZVI utilization for fluidized process due to abrasive motion of the ZVI. For influent chromate concentration of 418 mg/L as Cr 6+ , pH 2 and ZVI dosage of 3 g (41 g/L), chromate removal was only 29% with hydraulic detention time (HRT) of 1.2 min, but was increased to 99.9% by either increasing HRT to 5.6 min or adjusting pH to 1.5. For iron species at pH 2 and HRT of 1.2 min, Fe 3+ was more thermodynamically stable since oxidizing agent chromate was present. However, if pH was adjusted to 1.5 or 1, where chromate was completely removed, high Fe 2+ but very low Fe 3+ was present. It can be explained that ZVI reacted with chromate to produce Fe 2+ first and the presence of chromate would keep converting Fe 2+ to Fe 3+ . Therefore, Fe 2+ is an indicator for complete reduction from Cr(VI) to Cr(III). X-ray diffraction (XRD) was conducted to exam the remained species at pH 2. ZVI, iron oxide and iron sulfide were observed, indicating the formation of iron oxide or iron sulfide could stop the chromate reduction reaction

Iron and stony-iron meteorites

DEFF Research Database (Denmark)

Ruzicka, Alex M.; Haack, Henning; Chabot, Nancy L.

2017-01-01

By far most of the melted and differentiated planetesimals that have been sampled as meteorites are metal-rich iron meteorites or stony iron meteorites. The parent asteroids of these meteorites accreted early and differentiated shortly after the solar system formed, producing some of the oldest...... and interpretations for iron and stony iron meteorites (Plate 13.1). Such meteorites provide important constraints on the nature of metal-silicate separation and mixing in planetesimals undergoing partial to complete differentiation. They include iron meteorites that formed by the solidification of cores...... (fractionally crystallized irons), irons in which partly molten metal and silicates of diverse types were mixed together (silicate-bearing irons), stony irons in which partly molten metal and olivine from cores and mantles were mixed together (pallasites), and stony irons in which partly molten metal...

Fiber laser cladding of nickel-based alloy on cast iron

Energy Technology Data Exchange (ETDEWEB)

Arias-González, F., E-mail: felipeag@uvigo.es [Applied Physics Dpt., University of Vigo, EEI, Lagoas-Marcosende, Vigo E-36310 (Spain); Val, J. del [Applied Physics Dpt., University of Vigo, EEI, Lagoas-Marcosende, Vigo E-36310 (Spain); Comesaña, R. [Materials Engineering, Applied Mechanics and Construction Dpt., University of Vigo, EEI, Lagoas-Marcosende, Vigo E-36310 (Spain); Penide, J.; Lusquiños, F.; Quintero, F.; Riveiro, A.; Boutinguiza, M.; Pou, J. [Applied Physics Dpt., University of Vigo, EEI, Lagoas-Marcosende, Vigo E-36310 (Spain)

2016-06-30

Highlights: • Fiber laser cladding of Ni-based alloy on cast iron was experimentally studied. • Two different types of cast iron have been analyzed: gray and ductile cast iron. • Suitable processing parameters to generate a Ni-based coating were determined. • Dilution is higher in gray cast iron samples than in ductile cast iron. • Ni-based coating presents higher hardness than cast iron but similar Young's modulus. - Abstract: Gray cast iron is a ferrous alloy characterized by a carbon-rich phase in form of lamellar graphite in an iron matrix while ductile cast iron presents a carbon-rich phase in form of spheroidal graphite. Graphite presents a higher laser beam absorption than iron matrix and its morphology has also a strong influence on thermal conductivity of the material. The laser cladding process of cast iron is complicated by its heterogeneous microstructure which generates non-homogeneous thermal fields. In this research work, a comparison between different types of cast iron substrates (with different graphite morphology) has been carried out to analyze its impact on the process results. A fiber laser was used to generate a NiCrBSi coating over flat substrates of gray cast iron (EN-GJL-250) and nodular cast iron (EN-GJS-400-15). The relationship between processing parameters (laser irradiance and scanning speed) and geometry of a single laser track was examined. Moreover, microstructure and composition were studied by Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray Spectroscopy (EDS) and X-Ray Diffraction (XRD). The hardness and elastic modulus were analyzed by means of micro- and nanoindentation. A hardfacing coating was generated by fiber laser cladding. Suitable processing parameters to generate the Ni-based alloy coating were determined. For the same processing parameters, gray cast iron samples present higher dilution than cast iron samples. The elastic modulus is similar for the coating and the substrate, while the Ni

The interactive biotic and abiotic processes of DDT transformation under dissimilatory iron-reducing conditions.

Science.gov (United States)

Jin, Xin; Wang, Fang; Gu, Chenggang; Yang, Xinglun; Kengara, Fredrick O; Bian, Yongrong; Song, Yang; Jiang, Xin

2015-11-01

The objective of the study was to elucidate the biotic and abiotic processes under dissimilatory iron reducing conditions involved in reductive dechlorination and iron reduction. DDT transformation was investigated in cultures of Shewanella putrefaciens 200 with/without α-FeOOH. A modified first-order kinetics model was developed and described DDT transformation well. Both the α-FeOOH reduction rate and the dechlorination rate of DDT were positively correlated to the biomass. Addition of α-FeOOH enhanced reductive dechlorination of DDT by favoring the cell survival and generating Fe(II) which was absorbed on the surface of bacteria and iron oxide. 92% of the absorbed Fe(II) was Na-acetate (1M) extractable. However, α-FeOOH also played a negative role of competing for electrons as reflected by the dechlorination rate of DDT was inhibited when increasing the α-FeOOH from 1 g L(-1) to 5 g L(-1). DDT was measured to be toxic to S. putrefaciens 200. The metabolites DDD, DDE and DDMU were recalcitrant to S. putrefaciens 200. The results suggested that iron oxide was not the key factor to promote the dissipation of DDX (DDT and the metabolites), whereas the one-electron reduction potential (E1) of certain organochlorines is the main factor and that the E1 higher than the threshold of the reductive driving forces of DIRB probably ensures the occur of reductive dechlorination. Copyright © 2015 Elsevier Ltd. All rights reserved.

Microbial reduction of iron ore

Science.gov (United States)

Hoffmann, M.R.; Arnold, R.G.; Stephanopoulos, G.

1989-11-14

A process is provided for reducing iron ore by treatment with microorganisms which comprises forming an aqueous mixture of iron ore, microorganisms operable for reducing the ferric iron of the iron ore to ferrous iron, and a substrate operable as an energy source for the microbial reduction; and maintaining the aqueous mixture for a period of time and under conditions operable to effect the reduction of the ore. Preferably the microorganism is Pseudomonas sp. 200 and the reduction conducted anaerobically with a domestic wastewater as the substrate. An aqueous solution containing soluble ferrous iron can be separated from the reacted mixture, treated with a base to precipitate ferrous hydroxide which can then be recovered as a concentrated slurry. 11 figs.

The production and use of citric acid for the removal of potassium from the iron ore concentrate of the Sishen Iron Ore Mine, South Africa

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Peter J. Williams

2010-04-01

Full Text Available The depletion of the richer iron ore worldwide has made it necessary to process lower quality iron ore. Certain substances, such as potassium, contained within the lower quality iron ore, have a detrimental effect on the smelting process during steel manufacturing. Therefore, international steel-making companies charge penalties when purchasing iron ore concentrates containing high concentrations of potassium. To date, lower quality iron ore has been blended with high quality iron ore in an attempt to alleviate the potassium concentrations in the export iron ore; however, the ratio of low quality iron ore to high quality iron ore is increasing, thereby becoming an escalating problem within the economic functioning of the Sishen Iron Ore Mine. It has, therefore, become necessary to develop an economically viable and environmentally friendly process to reduce the high potassium concentrations contained in the iron ore concentrate of the Sishen Iron Ore Mine. In this study, we compared solid substrate and submerged fermentation using Aspergillus niger for the production of citric acid, which is used for the chemical leaching of potassium from the iron ore concentrate. It was found that submerged fermentation proved to be more economical and efficient, producing a maximum citric acid concentration of 102.3 g/L in 96 h of fermentation. ‘Heap leaching’ simulation experiments were found to be uneconomical, due to the required addition of fungal growth medium every 5 days as a result of growth factor depletion within this time; however, this process removed 17.65% of the potassium from the iron ore concentrate. By contrast, chemical leaching of potassium from the iron ore concentrate proved to be most efficient when using a 1 mol citric acid leaching solution at 60 ºC, removing 23.53% of the potassium contained within the iron ore concentrate. Therefore, the most economical and efficient process for the removal of potassium from the iron

Manufacture of barium hexaferrite (BaO3.98Fe2O3) from iron oxide waste of grinding process by using calcination process

Science.gov (United States)

Idayanti, N.; Dedi; Kristiantoro, T.; Mulyadi, D.; Sudrajat, N.; Alam, G. F. N.

2018-03-01

The utilization of iron oxide waste of grinding process as raw materials for making barium hexaferrite has been completed by powder metallurgy method. The iron oxide waste was purified by roasting at 800 °C temperature for 3 hours. The method used varying calcination temperature at 1000, 1100, 1200, and 1250 °C for 3 hours. The starting iron oxide waste (Fe2O3) and barium carbonate (BaCO3) were prepared by mol ratio of Fe2O3:BaCO3 from the formula BaO3.98Fe2O3. Some additives such as calcium oxide (CaO), silicon dioxide (SiO2), and polyvinyl alcohol (PVA) were added after calcination process. The samples were formed at the pressure of 2 ton/cm2 and sintered at the temperature of 1250 °C for 1 hour. The formation of barium hexaferrite compounds after calcination is determined by X-Ray diffraction. The magnetic properties were observed by Permagraph-Magnet Physik with the optimum characteristic at calcination temperature of 1250 °C with the induction of remanence (Br) = 1.38 kG, coercivity (HcJ) = 4.533 kOe, product energy maximum (BHmax) = 1.086 MGOe, and density = 4.33 g/cm3.

Metal regeneration of iron chelates in nitric oxide scrubbing

Science.gov (United States)

Chang, S.G.; Littlejohn, D.; Shi, Y.

1997-08-19

The present invention relates to a process of using metal particles to reduce NO to NH{sub 3}. More specifically, the invention concerns an improved process to regenerate iron (II) (CHELATE) by reduction of iron (II) (CHELATE) (NO) complex, which process comprises: (a) contacting an aqueous solution containing iron (II) (CHELATE) (NO) with metal particles at between about 20 and 90 C to reduce NO present, produce ammonia or an ammonium ion, and produce free iron (II) (CHELATE) at a pH of between about 3 and 8. The process is useful to remove NO from flue gas and reduce pollution. 34 figs.

Chemical process to separate iron oxides particles in pottery sample for EPR dating

Science.gov (United States)

Watanabe, S.; Farias, T. M. B.; Gennari, R. F.; Ferraz, G. M.; Kunzli, R.; Chubaci, J. F. D.

2008-12-01

Ancient potteries usually are made of the local clay material, which contains relatively high concentration of iron. The powdered samples are usually quite black, due to magnetite, and, although they can be used for thermoluminescene (TL) dating, it is easiest to obtain better TL reading when clearest natural or pre-treated sample is used. For electron paramagnetic resonance (EPR) measurements, the huge signal due to iron spin-spin interaction, promotes an intense interference overlapping any other signal in this range. Sample dating is obtained by dividing the radiation dose, determined by the concentration of paramagnetic species generated by irradiation, by the natural dose so as a consequence, EPR dating cannot be used, since iron signal do not depend on radiation dose. In some cases, the density separation method using hydrated solution of sodium polytungstate [Na 6(H 2W 12O 40)·H 2O] becomes useful. However, the sodium polytungstate is very expensive in Brazil; hence an alternative method for eliminating this interference is proposed. A chemical process to eliminate about 90% of magnetite was developed. A sample of powdered ancient pottery was treated in a mixture (3:1:1) of HCl, HNO 3 and H 2O 2 for 4 h. After that, it was washed several times in distilled water to remove all acid matrixes. The original black sample becomes somewhat clearer. The resulting material was analyzed by plasma mass spectrometry (ICP-MS), with the result that the iron content is reduced by a factor of about 9. In EPR measurements a non-treated natural ceramic sample shows a broad spin-spin interaction signal, the chemically treated sample presents a narrow signal in g = 2.00 region, possibly due to a radical of (SiO 3) 3-, mixed with signal of remaining iron [M. Ikeya, New Applications of Electron Spin Resonance, World Scientific, Singapore, 1993, p. 285]. This signal increases in intensity under γ-irradiation. However, still due to iron influence, the additive method yielded too

Ultrafine ferromagnetic iron oxide nanoparticles: Facile synthesis by low temperature decomposition of iron glycerolate

Energy Technology Data Exchange (ETDEWEB)

Bartůněk, Vilém, E-mail: vilem.bartunek@vscht.cz [Department of Inorganic Chemistry, Faculty of Chemical Technology, University of Chemistry and Technology, Technická 5, 166 28 Prague 6 (Czech Republic); Průcha, David [Department of Inorganic Chemistry, Faculty of Chemical Technology, University of Chemistry and Technology, Technická 5, 166 28 Prague 6 (Czech Republic); Švecová, Marie [Department of Analytical Chemistry, Faculty of Chemical Engineering, University of Chemistry and Technology, Technická 5, 166 28 Prague 6 (Czech Republic); Ulbrich, Pavel [Department of Biochemistry and Microbiology, Faculty of Food and Biochemical Technology, University of Chemistry and Technology, Technická 3, 166 28 Prague 6 (Czech Republic); Huber, Štěpán; Sedmidubský, David; Jankovský, Ondřej [Department of Inorganic Chemistry, Faculty of Chemical Technology, University of Chemistry and Technology, Technická 5, 166 28 Prague 6 (Czech Republic)

2016-09-01

We synthesized dark colored ultrafine – sub 10 nm iron oxide nanoparticles by a facile and low temperature process based on thermal decomposition of an affordable precursor – iron glycerolate. Simultaneous thermal analysis (STA) was used to study the thermal behaviour during the decomposition. The iron glycerolate was thoroughly analysed by various methods. The size of the iron nanoparticles was determined from XRD patterns and by transmission electron microscopy (TEM) and their composition has been confirmed by XPS. Magnetic properties of the nanoparticles were studied by vibrating sample magnetometry. The prepared single phase material exhibiting ferromagnetic properties is usable in a wide range of applications and may be suitable even for large scale industrial applications. - Highlights: • Iron glycerolate prepared and characterised. • Iron oxide nanoparticles prepared by thermal decomposition of iron glycerolate. • STA used to study the decomposition. • Products characterised by XRD, XPS, FT-IR, SEM and TEM. • Magnetic behaviour of monophasic samples determined.

Optimization of casting defects analysis with supply chain in cast iron foundry process

Directory of Open Access Journals (Sweden)

C. Narayanaswamy

2016-10-01

Full Text Available Some of the foundries are in need of meeting production targets and due to the urgency they ignore the rejections. The objective of this paper is to analyze the various defects, [1] from molding process in a cast iron foundry. The Failure Mode Effects Analysis (FMEA in quality control [2-6] with suitable supply chain for mold making process considering rejection rates are identified and analyzed in terms of Risk Priority Number (RPN to prioritize the attention for each of the problem. The optimum levels of selected parameters [7] are obtained in this analysis.

Powder metallurgical processing of magnetostrictive materials based on rare earth-iron intermetallic compounds

International Nuclear Information System (INIS)

Malekzadeh, M.

1978-01-01

Procedures are described for fabrication of high density rare earth-iron magnetostrictive compounds by powder metallurgical techniques. The fabrication involves a sequence of steps which includes preparing the pre-alloyed compounds, pulverizing them into a fine powder, compacting in suitable sizes and shapes, and sintering. Samples prepared by these procedures are carefully characterized by scanning electron microscopy, x-ray diffraction, dilatometry, and magnetic measurements. Process steps are found to exert important influences upon densities, microstructure and magnetic properties attained after densification. Investigations on a number of these process steps, including milling time and medium, sintering, and magnetic powder alignment are described

Effects of microbial redox cycling of iron on cast iron pipe corrosion in drinking water distribution systems.

Science.gov (United States)

Wang, Haibo; Hu, Chun; Zhang, Lili; Li, Xiaoxiao; Zhang, Yu; Yang, Min

2014-11-15

Bacterial characteristics in corrosion products and their effect on the formation of dense corrosion scales on cast iron coupons were studied in drinking water, with sterile water acting as a reference. The corrosion process and corrosion scales were characterized by electrochemical and physico-chemical measurements. The results indicated that the corrosion was more rapidly inhibited and iron release was lower due to formation of more dense protective corrosion scales in drinking water than in sterile water. The microbial community and denitrifying functional genes were analyzed by pyrosequencing and quantitative polymerase chain reactions (qPCR), respectively. Principal component analysis (PCA) showed that the bacteria in corrosion products played an important role in the corrosion process in drinking water. Nitrate-reducing bacteria (NRB) Acidovorax and Hydrogenophaga enhanced iron corrosion before 6 days. After 20 days, the dominant bacteria became NRB Dechloromonas (40.08%) with the protective corrosion layer formation. The Dechloromonas exhibited the stronger corrosion inhibition by inducing the redox cycling of iron, to enhance the precipitation of iron oxides and formation of Fe3O4. Subsequently, other minor bacteria appeared in the corrosion scales, including iron-respiring bacteria and Rhizobium which captured iron by the produced siderophores, having a weaker corrosion-inhibition effect. Therefore, the microbially-driven redox cycling of iron with associated microbial capture of iron caused more compact corrosion scales formation and lower iron release. Copyright © 2014 Elsevier Ltd. All rights reserved.

Microbial impact on metallic corrosion processes: case of iron reducing bacteria

International Nuclear Information System (INIS)

Esnault, Loic; Jullien, Michel; Libert, Marie; Mustin, Christian

2010-01-01

Document available in extended abstract form only. French concept of deep disposal of nuclear waste is based on a multi-barrier system with a metal container and a clayey host rock as last natural barrier for radionuclides confinement and to avoid their migration in the environment. One of the most important criteria for the safety assessment concerns the life time of metal containers. In this deep environment (elevated pressure and temperature, low water content) many factors may induce an alteration and modification of metal containers properties through corrosion processes. Two types of reactions are currently studied First, the anaerobic aqueous corrosion (a) which is depending on the amount of water available and the second is clayey corrosion (b) by an oxidation of structural Iron(III) or clay's H + on Fe(0) of metal containers. - Fe 0 + 2H 2 O → Fe 2+ + 2OH - + H 2 (a) - Fe 0 + 2H + argile → Fe 2+ solution + H 2 (b) - Fe 0 + Fe 3+ argile → Fe 2+ solution + Fe 2+ argile (b) These processes will entail different reaction products: first, we observe formation of corrosion products like aqueous Fe(II) and magnetite, hematite like mineral. These new minerals inhibit aqueous corrosion by the formation of a passivation process. For the second process, we observe a transformation of smectites into iron-rich serpentine-type minerals. These phenomenons will be responsible for a potential loss of confinement properties such as release of radionuclides, swelling and capacity to cations exchange. Moreover, since the discovery of microorganisms in deep clayey environment or in bentonite used as swelling clay. A new corrosion parameter 'biological one inducing bio-corrosion process' must be taken into account and has to be investigated to improve geochemical prediction on the sustainability of containers in geological disposal. - Impact of microorganisms has to be focused in term of bio-corrosion and more precisely on an indirect corrosion through the

Solubility of iron in liquid lead

International Nuclear Information System (INIS)

Ali-Khan, I.

1981-01-01

The use of liquid lead in high temperature chemical and metallurgical processes is well known. The structural materials applied for the containment of these processes are either iron base alloys or possess iron as an alloying element. Besides that, lead itself is alloyed in some steels to achieve some very useful properties. For understanding the effect of liquid lead in such structural materials, it is important to determine the solubility of iron in liquid lead which would also be indicative of the stability of these alloys. At the institute of reactor materials of KFA Juelich, investigations have been conducted to determine the solubility of iron in liquid lead up to a temperature of about 1000 0 C. In this presentation the data concerning the solubility of iron in liquid lead are brought up to date and discussed including the results of our previous investigations. (orig.)

The effect of austenitizing conditions in the ductile iron hardening process on longitudinal ultrasonic wave velocity

Directory of Open Access Journals (Sweden)

A. W. Orłowicz

2014-04-01

Full Text Available The paper presents results of a research on the effect of austenitizing temperature and time adopted in the hardening operation on the ultrasonic wave velocity in ductile iron. It has been found that with increasing austenitizing temperature and with the passage of the austenitizing time, a monotonic decrease of the ultrasonic longitudinal wave velocity value occurred. Implementation of ultrasonic testing of results obtained in the course of the cast iron hardening process both in production and as-cast conditions, requires development of a test methodology that must take into account the influence of base material structure (degree of nodularization, graphite precipitation count on the ultrasound wave velocity.

Effect of transferrin saturation on internal iron exchange

International Nuclear Information System (INIS)

Bergamaschi, G.; Eng, M.J.; Huebers, H.A.; Finch, C.A.

1986-01-01

Radioiron was introduced into the intestinal lumen to evaluate absorption, injected as nonviable red cells to evaluate reticuloendothelial (RE) processing of iron, and injected as hemoglobin to evaluate hepatocyte iron processing. Redistribution of iron through the plasma was evaluated in control animals and animals whose transferrin was saturated by iron infusion. Radioiron introduced into the lumen of the gut as ferrous sulfate and as transferrin-bound iron was absorbed about half as well in iron-infused animals, and absorbed iron was localized in the liver. The similar absorption of transferrin-bound iron suggested that absorption of ferrous iron occurred via the mucosal cell and did not enter by diffusion. The decrease in absorption was associated with an increase in mucosal iron and ferritin content produced by the iron infusion. An inverse relationship (r = -0.895) was shown between mucosal ferritin iron and absorption. When iron was injected as nonviable red cells, it was deposited predominantly in reticuloendothelial cells of the spleen. Return of this radioiron to the plasma was only 6% of that in control animals. While there was some movement of iron from spleen to liver, this could be accounted for by intravascular hemolysis. Injected hemoglobin tagged with radioiron was for the most part taken up and held by the liver. Some 13% initially localized in the marrow in iron-infused animals was shown to be storage iron unavailable for hemoglobin synthesis. These studies demonstrate the hepatic trapping of absorbed iron and the inability of either RE cell or hepatocyte to release iron in the transferrin-saturated animal

The variable contact pressure influence on the tensile force in the process of strip sliding in the flat die in ironing

Directory of Open Access Journals (Sweden)

Milan Djordjević

2016-07-01

Full Text Available Possibilities to influence the deep drawing process during its duration are limited and generally consist of influences at the flange of the thin sheet, mainly by the contact pressure (the blank holding force. The common characteristics of previous investigations were setting of the fixed values of the blank holding force or the holder's pressure within the ironing tool. The objective of this investigation was the continuous setting of the variable pressure during the sliding process, via the preset functions, in order to analyze the variable pressure influence on the ironing process. This is why an experimental computerized device was designed and constructed for analyzing the influence of the variable contact pressure on the sliding process of the model strip during the flat-die test. The multi-parameter experiment was conducted; various materials of the tested pieces were applied (primarily thin sheet made of Al alloys and low-carbon steels sheet, with and without coating; different versions of the tool's contact elements were used, with various friction regimes and influential parameters (variable contact pressure during the sliding process, etc.. This experimental device practically represents a simulator for realization and studying of the physical model of an important segment of the ironing process in the completely realistic conditions (materials, tools, etc.. The aim was to find the optimal combination of the variable contact pressure and the tribological parameters, so that the punch force, as one of the process output parameters, would have the minimal value, as well as to avoid the undesired effects during the forming (difficult sliding of the flange, appearance of thin sheet's wrinkling, structural destruction, etc.. Understanding the mutual dependence of the holder's variable pressure and other influences should enable improvement of the ironing process control and should contribute to better understanding of the phenomena

Determination of metallic iron in sponge-iron

International Nuclear Information System (INIS)

Mueller, C.S.

1974-01-01

The amount of metallic iron in sponge-iron is a parameter of major interest in the evaluation of the performance of the ore-reduction process and in the determination of the composition of the load of the electric furnace used to produce the steel. Moessbauer effect offers the promise of a simple and elegant analysis method, capable of competing directly with the usually time-consuming chemical procedures. The applicability of the method is considered and the possible sources of error are analyzed, resulting in the design of an instrument that is reasonably accurate and simple to use. Detailed electronic circuity required to produce a direct-reading digital instrument is shown [pt

Lead-iron phosophate glass

International Nuclear Information System (INIS)

Sales, B.C.; Boatner, L.A.

1988-01-01

The lead-iron phosphate nuclear waste glasses (LIPNWG) are the subject of the present chapter. They were discovered in 1984 while the authors were attempting to find a sintering aid for certain types of crystalline monazite ceramic high-level nuclear waste forms. In the present chapter, the term waste glass is synonymous with nuclear waste glass (NWG), and the acronym LIP is often used for lead-iron phosphate. Lead-iron phosphate glasses, like many of the previously studied phosphate glasses, are corrosion resistant in aqueous solutions at temperatures below 100 degrees C, and they can be melted and poured at temperatures that are relatively low in comparison with the processing temperatures required for current silicate glass compositions. Unlike the phosphate glasses investigated previously, however, LIPNWGs do not suffer from alteration due to devitrification during realistic and readily, achievable cooling periods. Additionally, lead-iron phosphate glass melts are not nearly as corrosive as the sodium phosphate melts investigated during the 1960s; and, therefore, they can be melted and processed using crucibles made from a variety of materials

Bioavailability of iron to rats from processed soybean fractions determined by intrinsic and extrinsic labeling techniques

International Nuclear Information System (INIS)

Weaver, C.M.; Nelson, N.; Elliott, J.G.

1984-01-01

Intrinsic and extrinsic labeling techniques were used to measure iron bioavailability from soybean fractions (isolated soy protein, defatted flour, soy hulls, insoluble material and whey) by iron-depleted and non-iron-depleted rats. As expected, absorption of iron was higher in the iron-depleted than in the non-iron-depleted rats. In the iron-depleted group, significantly more iron was absorbed from soy whey than from other fractions. No other significant difference in iron absorption associated with iron source was observed. The higher absorption rate of iron from whey by the iron-depleted rats probably was related to a lower quantity of food consumed during the test meal by this group. Intrinsic and extrinsic labeling techniques produced similar assessments of bioavailability of iron

The role of mitochondria in cellular iron-sulfur protein biogenesis and iron metabolism.

Science.gov (United States)

Lill, Roland; Hoffmann, Bastian; Molik, Sabine; Pierik, Antonio J; Rietzschel, Nicole; Stehling, Oliver; Uzarska, Marta A; Webert, Holger; Wilbrecht, Claudia; Mühlenhoff, Ulrich

2012-09-01

Mitochondria play a key role in iron metabolism in that they synthesize heme, assemble iron-sulfur (Fe/S) proteins, and participate in cellular iron regulation. Here, we review the latter two topics and their intimate connection. The mitochondrial Fe/S cluster (ISC) assembly machinery consists of 17 proteins that operate in three major steps of the maturation process. First, the cysteine desulfurase complex Nfs1-Isd11 as the sulfur donor cooperates with ferredoxin-ferredoxin reductase acting as an electron transfer chain, and frataxin to synthesize an [2Fe-2S] cluster on the scaffold protein Isu1. Second, the cluster is released from Isu1 and transferred toward apoproteins with the help of a dedicated Hsp70 chaperone system and the glutaredoxin Grx5. Finally, various specialized ISC components assist in the generation of [4Fe-4S] clusters and cluster insertion into specific target apoproteins. Functional defects of the core ISC assembly machinery are signaled to cytosolic or nuclear iron regulatory systems resulting in increased cellular iron acquisition and mitochondrial iron accumulation. In fungi, regulation is achieved by iron-responsive transcription factors controlling the expression of genes involved in iron uptake and intracellular distribution. They are assisted by cytosolic multidomain glutaredoxins which use a bound Fe/S cluster as iron sensor and additionally perform an essential role in intracellular iron delivery to target metalloproteins. In mammalian cells, the iron regulatory proteins IRP1, an Fe/S protein, and IRP2 act in a post-transcriptional fashion to adjust the cellular needs for iron. Thus, Fe/S protein biogenesis and cellular iron metabolism are tightly linked to coordinate iron supply and utilization. This article is part of a Special Issue entitled: Cell Biology of Metals. Copyright © 2012 Elsevier B.V. All rights reserved.

Characterization and uranium bioleaching performance of mixed iron- and sulfur-oxidizers versus iron-oxidizers

International Nuclear Information System (INIS)

Qian Li; Jing Sun; Dexin Ding; Qingliang Wang; Wenge Shi; Eming Hu; Xiaoyu Jiang; University of South China, Hengyang; Xingxing Wang

2017-01-01

In order to develop and apply mixed iron- and sulfur-oxidizers in uranium bioleaching, the characteristics of a mixed iron- and sulfur-oxidizing consortium (Consortium ISO) were comparatively investigated versus an iron-oxidizing consortium (Consortium IO). The results showed, the Consortium ISO exerted stronger oxidative ability and acid-producing ability than Consortium IO did. The synergy of sulfur-oxidizers and iron-oxidizers could change the structure and properties of the passivation substance, and work positively for eliminating the accumulation of passivation substance. In the bioleaching process, the uranium bioleaching experiments showed the recovery percentage of uranium reached 99.5% with Consortium ISO, 6.3% more than that of Consortium IO. (author)

Precipitated iron. A limit on gettering efficacy in multicrystalline silicon

Energy Technology Data Exchange (ETDEWEB)

Fenning, D.P.; Hofstetter, J.; Bertoni, M.I.; Buonassisi, T. [Massachusetts Institute of Technology MIT, Cambridge, Massachusetts 02139 (United States); Coletti, G. [ECN Solar Energy, Westerduinweg 3, NL-1755 LE Petten (Netherlands); Lai, B. [Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Del Canizo, C. [Instituto de Energia Solar, Universidad Politecnica de Madrid, 28040 Madrid (Spain)

2013-01-31

A phosphorus diffusion gettering model is used to examine the efficacy of a standard gettering process on interstitial and precipitated iron in multicrystalline silicon. The model predicts a large concentration of precipitated iron remaining after standard gettering for most as-grown iron distributions. Although changes in the precipitated iron distribution are predicted to be small, the simulated post-processing interstitial iron concentration is predicted to depend strongly on the as-grown distribution of precipitates, indicating that precipitates must be considered as internal sources of contamination during processing. To inform and validate the model, the iron distributions before and after a standard phosphorus diffusion step are studied in samples from the bottom, middle, and top of an intentionally Fe-contaminated laboratory ingot. A census of iron-silicide precipitates taken by synchrotron-based X-ray fluorescence microscopy confirms the presence of a high density of iron-silicide precipitates both before and after phosphorus diffusion. A comparable precipitated iron distribution was measured in a sister wafer after hydrogenation during a firing step. The similar distributions of precipitated iron seen after each step in the solar cell process confirm that the effect of standard gettering on precipitated iron is strongly limited as predicted by simulation. Good agreement between the experimental and simulated data supports the hypothesis that gettering kinetics is governed by not only the total iron concentration but also by the distribution of precipitated iron. Finally, future directions based on the modeling are suggested for the improvement of effective minority carrier lifetime in multicrystalline silicon solar cells.

Formation of poorly crystalline iron monosulfides: Surface redox reactions on high purity iron, spectroelectrochemical studies

Energy Technology Data Exchange (ETDEWEB)

Hansson, E.B. [Geological Institute, University of Copenhagen, Oster Voldgade 10, Copenhagen K, DK-1350 (Denmark); Odziemkowski, M.S. [Department of Earth Sciences, University of Waterloo, Waterloo, Ont., N2L 3G1 (Canada)]. E-mail: marek@sciborg.uwaterloo.ca; Gillham, R.W. [Department of Earth Sciences, University of Waterloo, Waterloo, Ont., N2L 3G1 (Canada)

2006-11-15

In the use of iron for reductive dehalogenation of chlorinated solvents in ground water, due to presence of sulfate-reducing bacteria the formation of hydrogen sulfide is expected. To simulate those processes the interface between 99.99% pure iron and 0.1 M NaHCO{sub 3} deoxygenated solution with 3.1 x 10{sup -5}-7.8 x 10{sup -3} M Na{sub 2}S . 9H{sub 2}O added was studied. The surface processes were characterised by the in situ normal Raman spectroscopy (NRS) and ex situ techniques; X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), energy dispersive X-ray (EDX). The open circuit potential (OCP) was monitored during in situ NRS measurements, and potentiodynamic anodic polarization measurements were carried out to reveal electrochemical behaviour of iron electrode. Open circuit potential-time transients indicated that the native oxide is unstable in deaerated bicarbonate solution and undergoes reductive dissolution (i.e. autoreduction) leaving the metallic Fe covered by Fe(OH){sub 2}, adsorbed OH{sup -}, and patches of 'magnetite-like' oxide. Immediately upon injection of the Na{sub 2}S-solution the iron interface undergoes complex redox surface processes and a poorly crystalline FeS film forms. Potentiodynamic anodic polarization measurements indicated a mechanical breakdown of the FeS film. The origin and initiation of this breakdown process is not clear but is probably a result of internal stress developed during film growth. Based on surface studies supported by electrochemical measurements, a conceptual model for the complex redox processes occurring at the iron interface is proposed. This model describes the structural development of a poorly crystalline FeS, which breaks down, allowing further dissolution of the Fe and formation of FeOOH at the interface. Simultaneously and despite the existence of thick layer of FeS the entrance of hydrogen was evident as the typical hydrogen cracks in bulk of the

Mineralogical issues in long-term corrosion of iron and iron-nickel alloys

International Nuclear Information System (INIS)

VanOrden, A.C.; McNeil, M.B.

1988-01-01

Prediction of very long term corrosion behavior of buried objects in general requires taking into account that the corrosion processes themselves after the local conditions. Recent work has analyzed corrosion processes in terms of trajectories on Pourbaix diagrams and appears to offer the prospect for using short-term corrosion tests to project corrosion behavior over very long periods. Two different classes of materials are considered here: essentially pure iron, which is an analogue to the carbon steel design overpacks for the salt and basalt sites (on which work has been suspended at present, and iron-nickel alloys, which are the best analogues available for some of the alloys being considered on the tuff site. There are a number of sources of data on corrosion of iron over archaeological times; the data used in this paper are from the recent National Bureau of Standards work on Roman iron nails for Inchtuthill in Scotland, which can be dated fairly precisely to about 70 A.D. and whose method of production is understood. The only available source of natural-analogue data on Fe-Ni alloys is the corrosion of meteorites

Atmospheric Processing of Volcanic Glass: Effects on Iron Solubility and Redox Speciation.

Science.gov (United States)

Maters, Elena C; Delmelle, Pierre; Bonneville, Steeve

2016-05-17

Volcanic ash from explosive eruptions can provide iron (Fe) to oceanic regions where this micronutrient limits primary production. Controls on the soluble Fe fraction in ash remain poorly understood but Fe solubility is likely influenced during atmospheric transport by condensation-evaporation cycles which induce large pH fluctuations. Using glass powder as surrogate for ash, we experimentally simulate its atmospheric processing via cycles of pH 2 and 5 exposure. Glass fractional Fe solubility (maximum 0.4%) is governed by the pH 2 exposure duration rather than by the pH fluctuations, however; pH 5 exposure induces precipitation of Fe-bearing nanoparticles which (re)dissolve at pH 2. Glass leaching/dissolution release Fe(II) and Fe(III) which are differentially affected by changes in pH; the average dissolved Fe(II)/Fetot ratio is ∼0.09 at pH 2 versus ∼0.18 at pH 5. Iron release at pH 2 from glass with a relatively high bulk Fe(II)/Fetot ratio (0.5), limited aqueous Fe(II) oxidation at pH 5, and possibly glass-mediated aqueous Fe(III) reduction may render atmospherically processed ash a significant source of Fe(II) for phytoplankton. By providing new insight into the form(s) of Fe associated with ash as wet aerosol versus cloud droplet, we improve knowledge of atmospheric controls on volcanogenic Fe delivery to the ocean.

The Process of Nanostructuring of Metal (Iron Matrix in Composite Materials for Directional Control of the Mechanical Properties

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Elena Zemtsova

2014-01-01

Full Text Available We justified theoretical and experimental bases of synthesis of new class of highly nanostructured composite nanomaterials based on metal matrix with titanium carbide nanowires as dispersed phase. A new combined method for obtaining of metal iron-based composite materials comprising the powder metallurgy processes and the surface design of the dispersed phase is considered. The following stages of material synthesis are investigated: (1 preparation of porous metal matrix; (2 surface structuring of the porous metal matrix by TiC nanowires; (3 pressing and sintering to give solid metal composite nanostructured materials based on iron with TiC nanostructures with size 1–50 nm. This material can be represented as the material type “frame in the frame” that represents iron metal frame reinforcing the frame of different chemical compositions based on TiC. Study of material functional properties showed that the mechanical properties of composite materials based on iron with TiC dispersed phase despite the presence of residual porosity are comparable to the properties of the best grades of steel containing expensive dopants and obtained by molding. This will solve the problem of developing a new generation of nanostructured metal (iron-based materials with improved mechanical properties for the different areas of technology.

Cast iron - a predictable material

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Jorg C. Sturm

2011-02-01

Full Text Available High strength compacted graphite iron (CGI or alloyed cast iron components are substituting previously used non-ferrous castings in automotive power train applications. The mechanical engineering industry has recognized the value in substituting forged or welded structures with stiff and light-weight cast iron castings. New products such as wind turbines have opened new markets for an entire suite of highly reliable ductile iron cast components. During the last 20 years, casting process simulation has developed from predicting hot spots and solidification to an integral assessment tool for foundries for the entire manufacturing route of castings. The support of the feeding related layout of the casting is still one of the most important duties for casting process simulation. Depending on the alloy poured, different feeding behaviors and self-feeding capabilities need to be considered to provide a defect free casting. Therefore, it is not enough to base the prediction of shrinkage defects solely on hot spots derived from temperature fields. To be able to quantitatively predict these defects, solidification simulation had to be combined with density and mass transport calculations, in order to evaluate the impact of the solidification morphology on the feeding behavior as well as to consider alloy dependent feeding ranges. For cast iron foundries, the use of casting process simulation has become an important instrument to predict the robustness and reliability of their processes, especially since the influence of alloying elements, melting practice and metallurgy need to be considered to quantify the special shrinkage and solidification behavior of cast iron. This allows the prediction of local structures, phases and ultimately the local mechanical properties of cast irons, to asses casting quality in the foundry but also to make use of this quantitative information during design of the casting. Casting quality issues related to thermally driven

Extracellular polymeric substances mediate bioleaching/biocorrosion via interfacial processes involving iron(III) ions and acidophilic bacteria.

Science.gov (United States)

Sand, Wolfgang; Gehrke, Tilman

2006-01-01

Extracellular polymeric substances seem to play a pivotal role in biocorrosion of metals and bioleaching, biocorrosion of metal sulfides for the winning of precious metals as well as acid rock drainage. For better control of both processes, the structure and function of extracellular polymeric substances of corrosion-causing or leaching bacteria are of crucial importance. Our research focused on the extremophilic bacteria Acidithiobacillus ferrooxidans and Leptospirillum ferrooxidans, because of the "simplicity" and knowledge about the interactions of these bacteria with their substrate/substratum and their environment. For this purpose, the composition of the corresponding extracellular polymeric substances and their functions were analyzed. The extracellular polymeric substances of both species consist mainly of neutral sugars and lipids. The functions of the exopolymers seem to be: (i) to mediate attachment to a (metal) sulfide surface, and (ii) to concentrate iron(III) ions by complexation through uronic acids or other residues at the mineral surface, thus, allowing an oxidative attack on the sulfide. Consequently, dissolution of the metal sulfide is enhanced, which may result in an acceleration of 20- to 100-fold of the bioleaching process over chemical leaching. Experiments were performed to elucidate the importance of the iron(III) ions complexed by extracellular polymeric substances for strain-specific differences in oxidative activity for pyrite. Strains of A. ferrooxidans with a high amount of iron(III) ions in their extracellular polymeric substances possess greater oxidation activity than those with fewer iron(III) ions. These data provide insight into the function of and consequently the advantages that extracellular polymeric substances provide to bacteria. The role of extracellular polymeric substances for attachment under the conditions of a space station and resulting effects like biofouling, biocorrosion, malodorous gases, etc. will be discussed.

A combined process of adsorption and Fenton-like oxidation for furfural removal using zero-valent iron residue.

Science.gov (United States)

Li, Furong; Bao, Jianguo; Zhang, Tian C; Lei, Yutian

2015-01-01

In this study, the feasibility of using a combined adsorption and Fenton-like oxidation process (with zero-valent iron (ZVI) residue from heat wraps as an absorbent and catalyst) to remove furfural in the solution was evaluated. The influencing parameters (e.g. pH, H2O2 concentration, initial furfural concentration) and the reusability of ZVI residue (to replace the iron powder) were estimated. The ZVI residue was found to have much better adsorption effect on furfural at pH 2.0 compared with pH 6.7. For Fenton-like reaction alone with ZVI residue, the highest furfural removal of 97.5% was observed at the concentration of 0.176 mol/L H2O2, and all of the samples had >80% removal efficiency at different initial furfural concentrations of 2, 10, 20, 30 and 40 mmol/L. However, with a combined adsorption and Fenton-like oxidation, the removal efficiency of furfural was nearly 100% for all treatments. The ZVI residue used for furfural removal was much better than that of iron powder in the Fenton-like reaction at a seven-cycle experiment. This study suggests the combined process of adsorption and Fenton-like oxidation using ZVI residue is effective for the treatment of furfural in the liquid.

Modelling Systemic Iron Regulation during Dietary Iron Overload and Acute Inflammation: Role of Hepcidin-Independent Mechanisms.

Science.gov (United States)

Enculescu, Mihaela; Metzendorf, Christoph; Sparla, Richard; Hahnel, Maximilian; Bode, Johannes; Muckenthaler, Martina U; Legewie, Stefan

2017-01-01

Systemic iron levels must be maintained in physiological concentrations to prevent diseases associated with iron deficiency or iron overload. A key role in this process plays ferroportin, the only known mammalian transmembrane iron exporter, which releases iron from duodenal enterocytes, hepatocytes, or iron-recycling macrophages into the blood stream. Ferroportin expression is tightly controlled by transcriptional and post-transcriptional mechanisms in response to hypoxia, iron deficiency, heme iron and inflammatory cues by cell-autonomous and systemic mechanisms. At the systemic level, the iron-regulatory hormone hepcidin is released from the liver in response to these cues, binds to ferroportin and triggers its degradation. The relative importance of individual ferroportin control mechanisms and their interplay at the systemic level is incompletely understood. Here, we built a mathematical model of systemic iron regulation. It incorporates the dynamics of organ iron pools as well as regulation by the hepcidin/ferroportin system. We calibrated and validated the model with time-resolved measurements of iron responses in mice challenged with dietary iron overload and/or inflammation. The model demonstrates that inflammation mainly reduces the amount of iron in the blood stream by reducing intracellular ferroportin transcription, and not by hepcidin-dependent ferroportin protein destabilization. In contrast, ferroportin regulation by hepcidin is the predominant mechanism of iron homeostasis in response to changing iron diets for a big range of dietary iron contents. The model further reveals that additional homeostasis mechanisms must be taken into account at very high dietary iron levels, including the saturation of intestinal uptake of nutritional iron and the uptake of circulating, non-transferrin-bound iron, into liver. Taken together, our model quantitatively describes systemic iron metabolism and generated experimentally testable predictions for additional

A novel conditioning process for enhancing dewaterability of waste activated sludge by combination of zero-valent iron and persulfate.

Science.gov (United States)

Zhou, Xu; Wang, Qilin; Jiang, Guangming; Liu, Peng; Yuan, Zhiguo

2015-06-01

Improvement of sludge dewaterability is crucial for reducing the costs of sludge disposal in wastewater treatment plants. This study presents a novel conditioning method for improving waste activated sludge dewaterability by combination of persulfate and zero-valent iron. The combination of zero-valent iron (0-30g/L) and persulfate (0-6g/L) under neutral pH substantially enhanced the sludge dewaterability due to the advanced oxidization reactions. The highest enhancement of sludge dewaterability was achieved at 4g persulfate/L and 15g zero-valent iron/L, with which the capillary suction time was reduced by over 50%. The release of soluble chemical oxygen demand during the conditioning process implied the decomposition of sludge structure and microorganisms, which facilitated the improvement of dewaterability due to the release of bound water that was included in sludge structure and microorganism. Economic analysis showed that the proposed conditioning process with persulfate and ZVI is more economically favorable for improving WAS dewaterability than classical Fenton reagent. Copyright © 2015 Elsevier Ltd. All rights reserved.

Change of iron species and iron solubility in Asian dust during the long-range transport from western China to Japan

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Y. Takahashi

2011-11-01

Full Text Available In the North Pacific, transport and deposition of mineral dust from Asia appear to be one of major sources of iron which can regulate growth of phytoplankton in the ocean. In this process, it is essential to identify chemical species of iron contained in Asian dust, because bioavailability of iron in the ocean is strongly influenced by the solubility of iron, which in turn is dependent on iron species in the dust. Here, we report that clay minerals (illite and chlorite in the dusts near the source collected at Aksu (western China can be transformed into ferrihydrite by atmospheric chemical processes during their long-range transport to eastern China (Qingdao and Japan (Tsukuba based on the speciation by X-ray absorption fine structure (XAFS and other methods such as X-ray diffraction and chemical extraction. As a result, Fe molar ratio in Aksu (illite : chlorite : ferrihydrite = 70 : 25 : 5 was changed to that in Tsukuba (illite : chlorite : ferrihydrite = 65 : 10 : 25. Moreover, leaching experiments were conducted to study the change of iron solubility. It was found that the iron solubility for the dust in Tsukuba (soluble iron fraction: 11.8 % and 1.10 % for synthetic rain water and seawater, respectively was larger than that in Aksu (4.1 % and 0.28 %, respectively, showing that iron in the dust after the transport becomes more soluble possibly due to the formation of ferrihydrite in the atmosphere. Our findings suggested that secondary formation of ferrihydrite during the transport should be considered as one of important processes in evaluating the supply of soluble iron to seawater.

Process evaluation of a national school-based iron supplementation program for adolescent girls in Iran.

Science.gov (United States)

Kheirouri, Sorayya; Alizadeh, Mohammad

2014-09-16

Iron deficiency anemia remains as one of the most common nutritional problems in Iran, especially in women and girls. A process evaluation study of the national iron supplementation program targeting girls attending high schools was conducted to examine degree of exposure and satisfaction of the targets with the intervention components, and to assess the delivery (quantity), fidelity (quality), and environmental mediators of the intervention. Three assessment tools were developed and used for the process evaluation. A total of 8 schools were selected using a simple randomization method. Data were collected from students (n = 658 of 661 participants), teachers (n = 80), and school principals (n = 7 of 8). For the qualitative measures semi-structured interviews were conducted with the three study groups. Mean continuous compliance was 62.3%. Intolerance to pills and no water supply in classrooms accounted for 47.72% and 36.21% of the refusals, respectively. The refusal rate was significantly correlated (p knowledge of iron deficiency issues (p < 0.05). The odds of refusal in the absence of a classroom water supply were 2.02 (95% CI 1 · 044 to 3 · 900) times greater than for those classrooms with a water supply. Student exposure to the program's goal was satisfactory; however, delivery and fidelity of educational materials and training sessions were inadequate. The findings suggest that the methods of delivery and the fidelity of the program components, education materials and training sessions were insufficient and need to be improved. Additionally, specific attention has to be given to contextual factors to ensure the success of the program.

In Situ Spectroscopic Analysis of the Carbothermal Reduction Process of Iron Oxides during Microwave Irradiation

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Jun Fukushima

2018-01-01

Full Text Available The effects of microwave plasma induction and reduction on the promotion of the carbothermal reduction of iron oxides (α-Fe2O3, γ-Fe2O3, and Fe3O4 are investigated using in situ emission spectroscopy measurements during 2.45 GHz microwave processing, and the plasma discharge (such as CN and N2 is measured during microwave E-field irradiation. It is shown that CN gas or excited CN molecules contribute to the iron oxide reduction reactions, as well as to the thermal reduction. On the other hand, no plasma is generated during microwave H-field irradiation, resulting in thermal reduction. Magnetite strongly interacts with the microwave H-field, and the reduction reaction is clearly promoted by microwave H-field irradiation, as well as thermal reduction reaction.

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.

The Aging of Iron Man

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Azhaar Ashraf

2018-03-01

Full Text Available Brain iron is tightly regulated by a multitude of proteins to ensure homeostasis. Iron dyshomeostasis has become a molecular signature associated with aging which is accompanied by progressive decline in cognitive processes. A common theme in neurodegenerative diseases where age is the major risk factor, iron dyshomeostasis coincides with neuroinflammation, abnormal protein aggregation, neurodegeneration, and neurobehavioral deficits. There is a great need to determine the mechanisms governing perturbations in iron metabolism, in particular to distinguish between physiological and pathological aging to generate fruitful therapeutic targets for neurodegenerative diseases. The aim of the present review is to focus on the age-related alterations in brain iron metabolism from a cellular and molecular biology perspective, alongside genetics, and neuroimaging aspects in man and rodent models, with respect to normal aging and neurodegeneration. In particular, the relationship between iron dyshomeostasis and neuroinflammation will be evaluated, as well as the effects of systemic iron overload on the brain. Based on the evidence discussed here, we suggest a synergistic use of iron-chelators and anti-inflammatories as putative anti-brain aging therapies to counteract pathological aging in neurodegenerative diseases.

The Aging of Iron Man.

Science.gov (United States)

Ashraf, Azhaar; Clark, Maryam; So, Po-Wah

2018-01-01

Brain iron is tightly regulated by a multitude of proteins to ensure homeostasis. Iron dyshomeostasis has become a molecular signature associated with aging which is accompanied by progressive decline in cognitive processes. A common theme in neurodegenerative diseases where age is the major risk factor, iron dyshomeostasis coincides with neuroinflammation, abnormal protein aggregation, neurodegeneration, and neurobehavioral deficits. There is a great need to determine the mechanisms governing perturbations in iron metabolism, in particular to distinguish between physiological and pathological aging to generate fruitful therapeutic targets for neurodegenerative diseases. The aim of the present review is to focus on the age-related alterations in brain iron metabolism from a cellular and molecular biology perspective, alongside genetics, and neuroimaging aspects in man and rodent models, with respect to normal aging and neurodegeneration. In particular, the relationship between iron dyshomeostasis and neuroinflammation will be evaluated, as well as the effects of systemic iron overload on the brain. Based on the evidence discussed here, we suggest a synergistic use of iron-chelators and anti-inflammatories as putative anti-brain aging therapies to counteract pathological aging in neurodegenerative diseases.

On iron radionuclide interactions and in situ measurement of iron corrosion products

International Nuclear Information System (INIS)

Puranen, A.; Jonsson, M.; Cui, D.; Scheidegger, A.M.; Wersin, P.; Spahiu, K.

2005-01-01

Full text of publication follows: In performance assessments of hard rock repositories, it is conservatively assumed that waste canisters are breached and that the spent fuel will get into contact with groundwater after 1000 years. When the canister eventually fails to protect HLW from groundwater, dissolved radionuclides from HLW will react with iron canister materials. The reactivity will depend on the conditions in solution and at the iron-water interface. To improve our understanding on the redox chemistry at near field conditions, batch experiments are conducted by contacting polished iron foils with a synthetic groundwater solution containing 10 mM NaCl, 2 mM NaHCO 3 and 5 ppm Se(IV), Se(VI), Tc(VII) and U(VI) in a glove box filled with Ar + 0.03% CO 2 gas mixture. The reaction rates are measured by analysing Se, Tc and U concentrations by ICP-MS. Iron corrosion products formed during the reaction(s) is monitored in-situ by a Layer Raman spectrometer through an optical window. The corrosion potential of the iron foil as well as the Eh and pH values of the bulk solution are recorded continuously during the experiment. The reacted iron foil is embedded with EPOXY resin, and the cross section will be analysed by SEM-EDS and XAS. The preliminary experimental results shows that with the formation of iron green rust FeII 4 FeIII 2 (OH) 12 CO 3 on iron foil, the rates of redox reactions between iron and the negatively charged radionuclides species are increased. The observation is explained by the fact that radionuclide anionic species can be first adsorbed then reduced on the positively charged outer surface of iron green rust. The positive charge is a result of the electrical balance of the negative charges of carbonate contained between the layered iron hydroxides in the green rust. Reduced forms of radionuclides are identified in the iron corrosion products. The results suggest that the formation of iron green rust as a corrosion product on the surface of iron

Use of lignite in the production of sponge iron and processing of waste oxides in rotary kilns

Energy Technology Data Exchange (ETDEWEB)

Eichberger, H; Schnabel, W; Serbent, H

1978-11-01

Based on a study of the situation of fossil energy reserves, processes are described in which non-coking coals, in particular lignite, are used for reduction in the rotary kiln, i.e. for sponge iron production and for zinc volatilization from waste oxides).

Interplay of domain walls and magnetization rotation on dynamic magnetization process in iron/polymer–matrix soft magnetic composites

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Dobák, Samuel, E-mail: samuel.dobak@student.upjs.sk [Institute of Physics, Faculty of Science, Pavol Jozef Šafárik University, Park Angelinum 9, 041 54 Košice (Slovakia); Füzer, Ján; Kollár, Peter [Institute of Physics, Faculty of Science, Pavol Jozef Šafárik University, Park Angelinum 9, 041 54 Košice (Slovakia); Fáberová, Mária; Bureš, Radovan [Institute of Materials Research, Slovak Academy of Sciences, Watsonova 47, 043 53 Košice (Slovakia)

2017-03-15

This study sheds light on the dynamic magnetization process in iron/resin soft magnetic composites from the viewpoint of quantitative decomposition of their complex permeability spectra into the viscous domain wall motion and magnetization rotation. We present a comprehensive view on this phenomenon over the broad family of samples with different average particles dimension and dielectric matrix content. The results reveal the pure relaxation nature of magnetization processes without observation of spin resonance. The smaller particles and higher amount of insulating resin result in the prevalence of rotations over domain wall movement. The findings are elucidated in terms of demagnetizing effects rising from the heterogeneity of composite materials. - Highlights: • A first decomposition of complex permeability into domain wall and rotation parts in soft magnetic composites. • A pure relaxation nature of dynamic magnetization processes. • A complete loss separation in soft magnetic composites. • The domain walls activity is considerably suppressed in composites with smaller iron particles and higher matrix content. • The demagnetizing field acts as a significant factor at the dynamic magnetization process.

Proteomic analysis of iron acquisition, metabolic and regulatory responses of Yersinia pestis to iron starvation

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Fleischmann Robert D

2010-01-01

little evidence for temperature-specific adaptation processes to iron starvation.

Computational modeling and analysis of iron release from macrophages.

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Alka A Potdar

2014-07-01

Full Text Available A major process of iron homeostasis in whole-body iron metabolism is the release of iron from the macrophages of the reticuloendothelial system. Macrophages recognize and phagocytose senescent or damaged erythrocytes. Then, they process the heme iron, which is returned to the circulation for reutilization by red blood cell precursors during erythropoiesis. The amount of iron released, compared to the amount shunted for storage as ferritin, is greater during iron deficiency. A currently accepted model of iron release assumes a passive-gradient with free diffusion of intracellular labile iron (Fe2+ through ferroportin (FPN, the transporter on the plasma membrane. Outside the cell, a multi-copper ferroxidase, ceruloplasmin (Cp, oxidizes ferrous to ferric ion. Apo-transferrin (Tf, the primary carrier of soluble iron in the plasma, binds ferric ion to form mono-ferric and di-ferric transferrin. According to the passive-gradient model, the removal of ferrous ion from the site of release sustains the gradient that maintains the iron release. Subcellular localization of FPN, however, indicates that the role of FPN may be more complex. By experiments and mathematical modeling, we have investigated the detailed mechanism of iron release from macrophages focusing on the roles of the Cp, FPN and apo-Tf. The passive-gradient model is quantitatively analyzed using a mathematical model for the first time. A comparison of experimental data with model simulations shows that the passive-gradient model cannot explain macrophage iron release. However, a facilitated-transport model associated with FPN can explain the iron release mechanism. According to the facilitated-transport model, intracellular FPN carries labile iron to the macrophage membrane. Extracellular Cp accelerates the oxidation of ferrous ion bound to FPN. Apo-Tf in the extracellular environment binds to the oxidized ferrous ion, completing the release process. Facilitated-transport model can

Serum Iron and Haemoglobin Estimation in Oral Submucous Fibrosis and Iron Deficiency Anaemia: A Diagnostic Approach.

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Bhardwaj, Divya; Dinkar, Ajit D; Satoskar, Sujata K; Desai, Sapna Raut

2016-12-01

Oral Submucous Fibrosis (OSMF) is a premalignant condition with potential malignant behaviour characterized by juxta-epithelial fibrosis of the oral cavity. In the process of collagen synthesis, iron gets utilized, by the hydroxylation of proline and lysine, leading to decreased serum iron levels. The trace element like iron is receiving much attention in the detection of oral cancer and precancerous condition like OSMF as it was found to be significantly altered in these conditions. The aim of this study was to compare the haemoglobin and serum iron values of OSMF subjects with that of iron deficiency anaemia subjects. Total of 120 subjects were included, 40 subjects with the OSMF, 40 with the iron deficiency anemia without tobacco chewing habit, 40 healthy control subjects without OSMF and iron deficiency anaemia. A total of 5ml of venous blood was withdrawn from all the subjects and serum iron and haemoglobin levels were estimated for all the subjects. Estimation of iron was done using Ferrozine method and haemoglobin by Sahli's method. The statistical method applied were Kruskal Wallis, Mann Whitney and Pearson correlation coefficient test. There was a statistically significant difference in serum iron and haemoglobin level in all three groups (pauxillary test in assessment of prognosis of the disease.

Iron Refractory Iron Deficiency Anaemia: A Rare Cause of Iron Deficiency Anaemia

LENUS (Irish Health Repository)

McGrath, T

2018-01-01

We describe the case of a 17-month-old boy with a hypochromic microcytic anaemia, refractory to oral iron treatment. After exclusion of dietary and gastrointestinal causes of iron deficiency, a genetic cause for iron deficiency was confirmed by finding two mutations in the TMPRSS6 gene, consistent with a diagnosis of iron-refractory iron deficiency anaemia (IRIDA).

Integrity of the iron transport process in mice with X-linked anaemia

International Nuclear Information System (INIS)

Thomson, A.B.R.; Valberg, L.S.

1975-01-01

The defect in iron (Fe) absorption in X-linked anaemia (sla) remains an enigma; absorption of a tracer dose of Fe is impaired in mice raised on an iron-containing cube diet but not in those raised on an iron-deficient diet. Because cobalt (Co) shares a similar intestinal transport pathway with Fe, a study was made of the effect of iron deficient diet on Co absorption. The duodenum of sla and genetically normal mice was perfused for 30 min with labelled solutions containing Co or Fe. Co uptake and transfer were similar in sla and normals fed cubes whereas Fe uptake and transfer were less in sla than in normals. The iron deficient diet caused an increase in the uptake and transfer of Co and Fe in sla and normals. When Co and Fe were perfused together in sla fed deficient diet, the uptake and transfer of each metal was less than when perfused alone. The distribution of Fe and Co in subcellular mucosal fractions was determined by a differential centrifugation technique. Deficient diet resulted in a directionally similar change in the subcellular distribution of Co and Fe in sla and normals. The increase in Co as well as Fe absorption in the sla on an iron deficient diet to the same high level found in genetically normal animals, and the inhibitory effect of each metal on the absorption of the other suggests that the absorption defect in sla is unlikely to be due to a primary defect in the function of the transport carrier. (author)

Ocean iron fertilization in the context of the Kyoto protocol and the post-Kyoto process

International Nuclear Information System (INIS)

Bertram, Christine

2010-01-01

Ocean iron fertilization is currently discussed as a potential measure to mitigate climate change by enhancing oceanic CO 2 uptake. Its mitigation potential is not yet well explored, and carbon offsets generated through iron fertilization activities could currently not be traded on regulated carbon markets. Still, commercial interests in ocean iron fertilization already exist, which underlines the need to investigate a possible regulatory framework for it. To this end, I first discuss important basic aspects of ocean iron fertilization, namely its scientific background, quantitative potential, side effects, and costs. In a second step, I review regulatory aspects connected to ocean iron fertilization, like its legal status and open access issues. Moreover, I analyze how the regulations for afforestation and reforestation activities within the framework of the Kyoto Clean Development Mechanism (CDM) could be applied to ocean iron fertilization. Main findings are that the quantitative potential of ocean iron fertilization is limited, that costs are higher than initially hoped, and that potential adverse side effects are severe. Moreover, the legal status of ocean iron fertilization is currently not well defined, open access might cause inefficiencies, and the CDM regulations could not be easily applied to ocean iron fertilization.

Application of Electrocoagulation Process Using Iron and Aluminum Electrodes for Fluoride Removal from Aqueous Environment

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Edris Bazrafshan

2012-01-01

Full Text Available Fluoride in drinking water above permissible level is responsible for human being affected by skeletal fluorosis. The present study was carried out to assess the ability of electrocoagulation process with iron and aluminum electrodes in order to removal of fluoride from aqueous solutions. Several working parameters, such as fluoride concentration, pH, applied voltage and reaction time were studied to achieve a higher removal capacity. Variable concentrations (1, 5 and 10 mg L-1 of fluoride solutions were prepared by mixing proper amount of sodium fluoride with deionized water. The varying pH of the initial solution (3, 7 and 10 was also studied to measure their effects on the fluoride removal efficiency. Results obtained with synthetic solution revealed that the most effective removal capacities of fluoride could be achieved at 40 V electrical potential. In addition, the increase of electrical potential, in the range of 10-40 V, enhanced the treatment rate. Also comparison of fluoride removal efficiency showed that removal efficiency is similar with iron and aluminum electrodes. Finally it can be concluded that the electrocoagulation process has the potential to be utilized for the cost-effective removal of fluoride from water and wastewater.

Ultrasonic C-scan Technique for Nondestructive Evaluation of Spot Weld Quality

International Nuclear Information System (INIS)

Park, Ik Gun

1994-01-01

This paper discusses the feasibility of ultrasonic C-scan technique for nondestructive evaluation of spot weld quality. Ultrasonic evaluation for spot weld quality was performed by immersion method with the mechanical and the electronic scanning of point-focussed ultrasonic beam(25 MHz). For the sake of the approach to the quantitative measurement of nugget diameter and the discrimination of the corona bond from nugget, preliminary infinitesimal gap experiment by newton ring is tried in order to set up the optimum ultrasonic test condition. Ultrasonic image data obtained were confirmed and compared by optical microscope and SAM(Scanning Acoustic Microscope) observation of the spot-weld cross section. The results show that the nugget diameter can be measured with the accuracy of 1.0mm, and voids included in nugget can be detected to 10μm extent with simplicity and accuracy. Finally, it was found that it is necessary to make a profound study of definite discrimination of corona bond from nugget and the approach of quantitative evaluation of nugget diameter by utilizing the various image processing techniques

The Efficiency of Strontium-90 Desorption Using Iron (III Solutions in the Decontamination Process of Radioactive Soils

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Olga Vladimirovna Cheremisina

2018-03-01

Full Text Available The paper presents the investigation on the estimated efficiency of iron (III chloride solutions in the decontamination process of radioactive soils with 90 Sr, according to kinetic and thermodynamic characteristics of the desorption process. The specific 90 Sr radioactivity of soil samples was (3.9±0.3·104 Bq·g. The adsorption isotherms of Sr 2+ and Fe 3+ are described with the Langmuir equation. The values of Gibbs energy G0298 = -4.65 kJ·mol -1 and equilibrium ion exchange constant Keq = 6,5 confirm the hypothesis of strontium removal from soils with iron (III cations. The effectiveness of the method is substantiated by experimental and calculated results of this study samples of radioactive soils are deactivated in 90% after 9.5 hours, whereas the kinetic constant is 6.77·10 s -1 . The suggested method of soil cleanup with 0.2 M Fe 3+ solutions is optimal and complies with the environmental requirements.

Adsorptive removal of arsenic by novel iron/olivine composite: Insights into preparation and adsorption process by response surface methodology and artificial neural network.

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Ghosal, Partha S; Kattil, Krishna V; Yadav, Manoj K; Gupta, Ashok K

2018-03-01

Olivine, a low-cost natural material, impregnated with iron is introduced in the adsorptive removal of arsenic. A wet impregnation method and subsequent calcination were employed for the preparation of iron/olivine composite. The major preparation process parameter, viz., iron loading and calcination temperature were optimized through the response surface methodology coupled with a factorial design. A significant variation of adsorption capacity of arsenic (measured as total arsenic), i.e., 63.15 to 310.85 mg/kg for arsenite [As(III) T ] and 76.46 to 329.72 mg/kg for arsenate [As(V) T ] was observed, which exhibited the significant effect of the preparation process parameters on the adsorption potential. The iron loading delineated the optima at central points, whereas a monotonous decreasing trend of adsorption capacity for both the As(III) T and As(V) T was observed with the increasing calcination temperature. The variation of adsorption capacity with the increased iron loading is more at lower calcination temperature showing the interactive effect between the factors. The adsorbent prepared at the optimized condition of iron loading and calcination temperature, i.e., 10% and 200 °C, effectively removed the As(III) T and As(V) T by more than 96 and 99%, respectively. The material characterization of the adsorbent showed the formation of the iron compound in the olivine and increase in specific surface area to the tune of 10 multifold compared to the base material, which is conducive to the enhancement of the adsorption capacity. An artificial neural network was applied for the multivariate optimization of the adsorption process from the experimental data of the univariate optimization study and the optimized model showed low values of error functions and high R 2 values of more than 0.99 for As(III) T and As(V) T . The adsorption isotherm and kinetics followed Langmuir model and pseudo second order model, respectively demonstrating the chemisorption in this

Heme metabolism as an integral part of iron homeostasis

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Paweł Lipiński

2014-01-01

Full Text Available Heme, a ferrous iron protoporphyrin IX complex, is employed as a prosthetic group in a number of diverse heme proteins that participate in important cellular and systemic physiological processes. Provision of an adequate amount of iron for heme biosynthesis is one of the elemental hallmarks of intracellular iron homeostasis. In the cell the bioavailability of iron for the two main iron biological pathways – heme synthesis and the biogenesis of iron-sulfur clusters ([Fe-S] – is mainly regulated by the IRP/IRE posttranscriptional system. The biogenesis of [Fe-S] centers is crucial for heme synthesis because these co-factors determine the activity of IRP1 and that of ferrochelatase, an enzyme responsible for the insertion of an iron into protoporphyrin IX to produce heme. On the other hand, delivery of iron for heme and hemoglobin synthesis in erythroblasts, precursors of erythrocytes in bone marrow, is an indispensable element of body iron homeostasis. This process relies on the recovery of iron from senescent red blood cells through the enzymatic degradation of heme molecules and recycling of iron to the circulation. Molecular coordination of these processes involves the activity of heme oxygenase 1, IRP1 and IRP2 as well as the functioning of the hepcidin-ferroportin regulatory axis. Recent studies show in mammals the existence of an expanded system of proteins involved in the transport of intact heme molecules at the cellular and systemic levels. The biological role of this system is of particular importance when the concentration of free heme reaches a toxic level in the body (intravascular hemolysis as well as locally in cells having intensive heme metabolism such as erythroblasts and macrophages.

[Heme metabolism as an integral part of iron homeostasis].

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Lipiński, Paweł; Starzyński, Rafał R; Styś, Agnieszka; Gajowiak, Anna; Staroń, Robert

2014-01-02

Heme, a ferrous iron protoporphyrin IX complex, is employed as a prosthetic group in a number of diverse heme proteins that participate in important cellular and systemic physiological processes. Provision of an adequate amount of iron for heme biosynthesis is one of the elemental hallmarks of intracellular iron homeostasis. In the cell the bioavailability of iron for the two main iron biological pathways--heme synthesis and the biogenesis of iron-sulfur clusters ([Fe-S])--is mainly regulated by the IRP/IRE posttranscriptional system. The biogenesis of [Fe-S] centers is crucial for heme synthesis because these co-factors determine the activity of IRP1 and that of ferrochelatase, an enzyme responsible for the insertion of an iron into protoporphyrin IX to produce heme. On the other hand, delivery of iron for heme and hemoglobin synthesis in erythroblasts, precursors of erythrocytes in bone marrow, is an indispensable element of body iron homeostasis. This process relies on the recovery of iron from senescent red blood cells through the enzymatic degradation of heme molecules and recycling of iron to the circulation. Molecular coordination of these processes involves the activity of heme oxygenase 1, IRP1 and IRP2 as well as the functioning of the hepcidin-ferroportin regulatory axis. Recent studies show in mammals the existence of an expanded system of proteins involved in the transport of intact heme molecules at the cellular and systemic levels. The biological role of this system is of particular importance when the concentration of free heme reaches a toxic level in the body (intravascular hemolysis) as well as locally in cells having intensive heme metabolism such as erythroblasts and macrophages.

Natural resources sustainability: iron ore mining

International Nuclear Information System (INIS)

De La Torre de Palacios, Luis

2011-01-01

In the present article, a new tool to determine environmental sustainability, the energy impact index (EII) was developed to classify different iron mine projects according to two main parameters including energy consumption and CO 2 emissions. The EII considers the characteristics of the mineral (such as the quality, size, hardness, iron ore grade, reducibility, mineral/waste rate, and type of deposit), mining processes (type of exploitation, ore processing, available technology), and transportation (distance to cover).

Use characterisation of a diatomite catalyst impregnated with iron in the heterogeneous catalytic ozonization process

International Nuclear Information System (INIS)

Garcia Herrera, Walter

2014-01-01

Advanced oxidation processes have had a promising option in the treatment of wastewater, mainly in the presence of emerging and persistent pollutants. Among these processes have highlighted the catalytic ozonization, which has showed positive results in water treatment. Heterogeneous catalytic ozonization was characterized using diatomite impregnated with iron at the Universidad de Costa Rica. Contaminant degradation model was quantified (spectrophotometrically) for ozonization process and catalytic ozonization with the catalyst studied (1.000 g / L) at three different pH 4, 7 and 10. The effect of the catalyst concentration in the solution (0.250, 0.500, 1000, 1500 and 2.000 g/L) was determined under the conditions of pH with better performance of the catalyst. Runs in the presence of tert-butyl alcohol (TBA), known hydroxyl radical scavenger were performed to evaluate the effect on ozone indirect reactions. The degree of mineralization obtained was measured in the catalytic process.The variation of the COD of the solution was quantified under the best working conditions obtained. Finally, the performance of the catalyst in 4 cycles of reuse was studied by monitoring the leached iron of the catalyst, which has turned out to be 12%. Most degradation of contaminant model in ozonization process was obtained at pH 10, in accordance with the above theory (Buhler, Stachelin, & Hoigne, 1984). In contrast, at pH 4 the catalyst has presented the best efficiency, to the 3 minutes the noncatalytic process was curettaged 35% of dye, while the catalytic process by 60% in the same time. The degradation of the contaminant was improved even in the case of noncatalytic process at pH 10, which the 3 minutes was degradated to 44%. The presence of the catalyst at initial pH of 7 and 10, has showed without significant improvements in the process. The solution concentration of catalyst has presented the best efficiency of degradation has been 2,000 g/L, which has increased 70% to 3

The adsorption of orthophosphate onto casein-iron precipitates.

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Mittal, Vikas A; Ellis, Ashling; Ye, Aiqian; Edwards, Patrick J B; Singh, Harjinder

2018-01-15

This study explored the interactions of orthophosphate with casein-iron precipitates. Casein-iron precipitates were formed by adding ferric chloride at ≥10mM to sodium caseinate solutions ranging in concentration from 1 to 3%(w/v). The addition of different concentrations of orthophosphate solution to the casein-iron precipitates resulted in gradual adsorption of the orthophosphate, causing re-dispersion of the casein-iron complexes. The interactions of added orthophosphate with iron in the presence and absence of caseins are postulated, and new mechanisms are proposed. The re-dispersed soluble complexes of casein-iron-orthophosphate generated using this process could be used as novel iron fortificants. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of iron ions and electric field on nitrification process in the periodic reversal bio-electrocoagulation system.

Science.gov (United States)

Qian, Guangsheng; Hu, Xiaomin; Li, Liang; Ye, Linlin; Lv, Weijian

2017-11-01

This study explored the nitrification mechanism of a periodic reversal bio-electrocoagulation system with Fe-C electrodes. The ammonia nitrogen removal was compared in four identical cylindrical sequencing bath reactors. Two of them were reactors with Fe-C electrodes (S1) and C-C electrodes (S2), respectively. The other two were a reactor with iron ions (S3) and a traditional SBR (S4), respectively. The results demonstrated that the effect on enhancing nitrification in S1 was the best among all four SBRs, followed by S3, S2 and S4. Iron ions increased the biomass, and electric field improved the proton transfer and enzyme activity. The dominant bacterial genera in the four SBRs were Hyphomicrobium, Thauera, Nitrobacter, Nitrosomonas, Paracoccus and Hydrogenophaga. The iron ions may increase the levels of Nitrosomonas and Nitrobacter, both of which were the main microbes of the nitrification process. This study provided a significant and meaningful understanding of nitrification in a bio-electrocoagulation system. Copyright © 2017 Elsevier Ltd. All rights reserved.

Solubility of iron from combustion source particles in acidic media linked to iron speciation.

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Fu, Hongbo; Lin, Jun; Shang, Guangfeng; Dong, Wenbo; Grassian, Vichi H; Carmichael, Gregory R; Li, Yan; Chen, Jianmin

2012-10-16

In this study, iron solubility from six combustion source particles was investigated in acidic media. For comparison, a Chinese loess (CL) dust was also included. The solubility experiments confirmed that iron solubility was highly variable and dependent on particle sources. Under dark and light conditions, the combustion source particles dissolved faster and to a greater extent relative to CL. Oil fly ash (FA) yielded the highest soluble iron as compared to the other samples. Total iron solubility fractions measured in the dark after 12 h ranged between 2.9 and 74.1% of the initial iron content for the combustion-derived particles (Oil FA > biomass burning particles (BP) > coal FA). Ferrous iron represented the dominant soluble form of Fe in the suspensions of straw BP and corn BP, while total dissolved Fe presented mainly as ferric iron in the cases of oil FA, coal FA, and CL. Mössbauer measurements and TEM analysis revealed that Fe in oil FA was commonly presented as nanosized Fe(3)O(4) aggregates and Fe/S-rich particles. Highly labile source of Fe in corn BP could be originated from amorphous Fe form mixed internally with K-rich particles. However, Fe in coal FA was dominated by the more insoluble forms of both Fe-bearing aluminosilicate glass and Fe oxides. The data presented herein showed that iron speciation varies by source and is an important factor controlling iron solubility from these anthropogenic emissions in acidic solutions, suggesting that the variability of iron solubility from combustion-derived particles is related to the inherent character and origin of the aerosols themselves. Such information can be useful in improving our understanding on iron solubility from combustion aerosols when they undergo acidic processing during atmospheric transport.

Genetics Home Reference: iron-refractory iron deficiency anemia

Science.gov (United States)

... refractory iron deficiency anemia Iron-refractory iron deficiency anemia Printable PDF Open All Close All Enable Javascript ... expand/collapse boxes. Description Iron-refractory iron deficiency anemia is one of many types of anemia , which ...

The pupylation machinery is involved in iron homeostasis by targeting the iron storage protein ferritin.

Science.gov (United States)

Küberl, Andreas; Polen, Tino; Bott, Michael

2016-04-26

The balance of sufficient iron supply and avoidance of iron toxicity by iron homeostasis is a prerequisite for cellular metabolism and growth. Here we provide evidence that, in Actinobacteria, pupylation plays a crucial role in this process. Pupylation is a posttranslational modification in which the prokaryotic ubiquitin-like protein Pup is covalently attached to a lysine residue in target proteins, thus resembling ubiquitination in eukaryotes. Pupylated proteins are recognized and unfolded by a dedicated AAA+ ATPase (Mycobacterium proteasomal AAA+ ATPase; ATPase forming ring-shaped complexes). In Mycobacteria, degradation of pupylated proteins by the proteasome serves as a protection mechanism against several stress conditions. Other bacterial genera capable of pupylation such as Corynebacterium lack a proteasome, and the fate of pupylated proteins is unknown. We discovered that Corynebacterium glutamicum mutants lacking components of the pupylation machinery show a strong growth defect under iron limitation, which was caused by the absence of pupylation and unfolding of the iron storage protein ferritin. Genetic and biochemical data support a model in which the pupylation machinery is responsible for iron release from ferritin independent of degradation.

Constructal design of a blast furnace iron-making process based on multi-objective optimization

International Nuclear Information System (INIS)

Liu, Xiong; Chen, Lingen; Feng, Huijun; Qin, Xiaoyong; Sun, Fengrui

2016-01-01

For the fixed total raw material cost and based on constructal theory and finite time thermodynamics, a BFIM (blast furnace iron-making) process is optimized by taking a complex function as optimization objective. The complex function is integrated with HM (hot metal) yield and useful energy of the BF (blast furnace). The optimal cost distribution of raw materials (namely “generalized optimal construct”) is obtained. The effects of some parameters, such as oxygen enrichment, blast temperature and pulverized coal dosage, on the optimization results are analyzed. The results show that the HM yield, useful energy and complex function are, respectively, increased by 3.13%, 2.66% and 2.90% after generalized constructal optimization. The utilization efficiencies of the BFG (blast furnace gas) and slag are 41.3% and 57.1%, respectively, which means that the utilization potentials of the BFG and slag can be further exploited. Increasing pulverized coal dosage and decreasing the agglomerate ratio can increase the complex function. The performance the BFIM process can be improved by adjusting the oxygen enrichment, blast temperature, blast dosage, pressure ratio of the Brayton cycle's air compressor and relative pressure drop of the air compressor inlet to their optimal values, respectively, which are new findings of this paper. - Highlights: • Constructal optimization of a blast furnace iron-making process is performed. • Finite time thermodynamic model of open Brayton cycle is adopted. • Weighting function is taken as optimization objective. • Optimal cost distribution of the raw materials is obtained.

The production of pig iron from crushing plant waste using hot blast cupola

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Kusno Isnugroho

2018-03-01

Full Text Available A production of pig iron has been conducted from crushing plant waste. The process of preparing pig iron was using hot blast cupola (HBC furnace which was injected with charcoal powder to improve temperature process and reduction zone in the furnace. The process was started by washing process and magnetic separation of raw material as an effort to improve iron content degree from crushing plant waste. The next process was preparing the composite pellet with the particle size of −80 + 100 mesh and with the composition of 80% iron ore, 15% wood charcoal, and 5% bentonite. The result of pellet size was 2.5–4.0 mm. The experiment was continued to reduce pellet composite in the HBC furnace. The pig iron produced from this process contained of 93.62%Fe, 3.5%C, 1.55%Si, 0.87%Mn, 0.05%P, and 0.087%S.With this result, the pig iron produced already fulfill the metallurgical specification to be used in smelting industry. Keywords: Pig iron, Pellet, Injection, Charcoal, Hot blast cupola

Novel insights into iron metabolism by integrating deletome and transcriptome analysis in an iron deficiency model of the yeast Saccharomyces cerevisiae

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Arkin Adam P

2009-03-01

Full Text Available Abstract Background Iron-deficiency anemia is the most prevalent form of anemia world-wide. The yeast Saccharomyces cerevisiae has been used as a model of cellular iron deficiency, in part because many of its cellular pathways are conserved. To better understand how cells respond to changes in iron availability, we profiled the yeast genome with a parallel analysis of homozygous deletion mutants to identify essential components and cellular processes required for optimal growth under iron-limited conditions. To complement this analysis, we compared those genes identified as important for fitness to those that were differentially-expressed in the same conditions. The resulting analysis provides a global perspective on the cellular processes involved in iron metabolism. Results Using functional profiling, we identified several genes known to be involved in high affinity iron uptake, in addition to novel genes that may play a role in iron metabolism. Our results provide support for the primary involvement in iron homeostasis of vacuolar and endosomal compartments, as well as vesicular transport to and from these compartments. We also observed an unexpected importance of the peroxisome for growth in iron-limited media. Although these components were essential for growth in low-iron conditions, most of them were not differentially-expressed. Genes with altered expression in iron deficiency were mainly associated with iron uptake and transport mechanisms, with little overlap with those that were functionally required. To better understand this relationship, we used expression-profiling of selected mutants that exhibited slow growth in iron-deficient conditions, and as a result, obtained additional insight into the roles of CTI6, DAP1, MRS4 and YHR045W in iron metabolism. Conclusion Comparison between functional and gene expression data in iron deficiency highlighted the complementary utility of these two approaches to identify important functional

Effect of dietary iron source and iron status on iron bioavailability tests in the rat

International Nuclear Information System (INIS)

Zhang, D.; Hendricks, D.G.; Mahoney, A.W.

1986-01-01

Weanling male rats were made anemic in 7 days by feeding a low iron diet and bleeding. Healthy rats were fed the low iron diet supplemented with ferrous sulfate (29 ppm Fe). Each group was subdivided and fed for 10 days on test diets containing about 29 ppm iron that were formulated with meat:spinach mixtures or meat:soy mixtures to provided 100:0, 75:25, 50:50, 25:75, or 0:100% of the dietary iron from these sources or from a ferrous sulfate diet. After 3 days on the diets all rats were dosed orally with 2 or 5 micro curries of 59 Fe after a 18 hour fast and refeeding for 1.5 hours. Iron status influenced liver iron, carcass iron, liver radio activity and percent of radioactive dose retained. Diet influenced fecal iron and apparent absorption of iron. In iron bioavailability studies assessment methodology and iron status of the test subject greatly influences the estimates of the value of dietary sources of iron

Phosphorus Retention (32P) by synthetic iron oxides

International Nuclear Information System (INIS)

Bittencourt, V.C.; Montanheiro, M.N.S.

1975-02-01

The P retention by iron oxides was characterized as a chemical adsorption process followed by a physical adsorption. The former process was very intense with initial amounts of added P but after a certain surface saturation is reached physical interaction occurs. It was supposed that the chemically adsorbed phosphate confers a negative charge on the iron oxides particles, which repels any further physical adsorbtion of the anion. However due to diffusion of phosphate ions into the internal layers of the iron oxides, their surface can retain further amounts of P [pt

Effect of electrical pulse treatment on the thermal fatigue resistance of bionic compacted graphite cast iron processed in water

International Nuclear Information System (INIS)

Liu, Yan; Zhou, Hong; Su, Hang; Yang, Chunyan; Cheng, Jingyan; Zhang, Peng; Ren, Luquan

2012-01-01

Highlights: ► Electrical pulse treatment can reduce cracks on bionic units before thermal fatigue tests. ► Electrical pulse treatment can reduce crack sources during thermal fatigue tests. ► Thermal fatigue resistance of bionic units processed in water is enhanced. ► Thermal fatigue resistance of bionic CGI processed in water is improved. -- Abstract: In order to further enhance the thermal fatigue resistance of bionic compacted graphite cast iron (CGI) which is processed by laser in water, the electrical pulse treatment is applied to improve the thermal fatigue resistance of bionic units. The results show that the electrical pulse treatment causes the supersaturated carbon atoms located in the lattice of austenite to react with the iron atoms to form the Fe 3 C. The microstructures of the bionic units processed in water are refined by the electrical pulse treatment. The cracks on the bionic units are reduced by the electrical pulse treatment before the thermal fatigue tests; and during the tests, the thermal fatigue resistance of bionic units is therefore enhanced by reducing the crack sources. By this way, the thermal fatigue resistance of bionic CGI processed in water is improved.

Vacuolar iron transporter BnMEB2 is involved in enhancing iron tolerance of Brassica napus

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Wei Zhu

2016-09-01

Full Text Available Iron toxicity is a major nutrient disorder that severely affects crop development and yield. Vacuolar detoxification of metal stress is an important strategy for plants to survive and adapt to this adverse environment. Vacuolar iron transporter (VIT members are involved in this process and play essential roles in iron storage and transport. In this study, a rapeseed VIT gene BnMEB2 (BnaC07g30170D was identified. BnMEB2 is a homolog to Arabidopsis MEB2 (At5g24290 and acts as a detoxifier in vacuolar sequestration of divalent metal. Transient expression analysis revealed that BnMEB2 was localized to the vacuolar membrane. Q-PCR detection showed a high expression of BnMEB2 in mature (60-day-old leaves and could be obviously induced by exogenous iron stress in both roots and leaves. Over-expressed BnMEB2 in both Arabidopsis wild type and meb2 mutant seedlings resulted in greatly improved iron tolerability with no significant changes in the expression level of other vacuolar iron transporter genes. The mutant meb2 grew slowly and its root hair elongation was inhibited under high iron concentration condition while BnMEB2 over-expressed transgenic plants of the mutant restored the phenotypes with apparently higher iron storage in roots and dramatically increased iron content in the whole plant. Taken together, these results suggested that BnMEB2 was a VIT gene in rapeseed which was necessary for safe storage and vacuole detoxification function of excess iron to enhance the tolerance of iron toxicity. This research sheds light on a potentially new strategy for attenuating hazardous metal stress from environment and improving iron biofortification in Brassicaceae crops.

Dechlorination of Hexachloroethane in Water Using Iron Shavings and Amended Iron Shavings: Kinetics and Pathways

Directory of Open Access Journals (Sweden)

D. L. Wu

2014-01-01

Full Text Available In contrast to previous studies which employed zero-valent iron powder, this paper investigated reductive dechlorination of hexachloroethane (HCA using iron shavings and bimetallic iron shavings modified with Cu, Ag, or Pd. Results clearly show that iron shavings offer superior reductive dechlorination of HCA. In addition, surface-normalized pseudo first-order dechlorination rates of 0.0073 L·m−2·h−1, 0.0136 L·m−2·h−1, 0.0189 L·m−2·h−1, and 0.0084 L·m−2·h−1 were observed in the presence of iron shavings (Fe0 and the bimetallic iron shavings Cu/Fe, Ag/Fe, and Pd/Fe, respectively. Bimetallic iron shavings consisting of Cu/Fe and Ag/Fe could greatly enhance the reductive reaction rate; Pd/Fe was used to achieve complete dechlorination of HCA within 5 hours. The additives of Ag and Pd shifted product distributions, and the reductive dechlorination of HCA occurred via β reductive elimination and sequential hydrogenolysis in the presence of all iron shavings. This study consequently designed a reaction pathway diagram which reflected the reaction pathway and most prevalent dechlorination products. Iron shavings are a common byproduct of mechanical processing plants. While the purity of such Fe metals may be low, these shavings are readily available at low costs and could potentially be used in engineering applications such as contamination control technologies.

Atmospheric processing outside clouds increases soluble iron in mineral dust.

Science.gov (United States)

Shi, Zongbo; Krom, Michael D; Bonneville, Steeve; Benning, Liane G

2015-02-03

Iron (Fe) is a key micronutrient regulating primary productivity in many parts of the global ocean. Dust deposition is an important source of Fe to the surface ocean, but most of this Fe is biologically unavailable. Atmospheric processing and reworking of Fe in dust aerosol can increase the bioavailable Fe inputs to the ocean, yet the processes are not well understood. Here, we experimentally simulate and model the cycling of Fe-bearing dust between wet aerosol and cloud droplets. Our results show that insoluble Fe in dust particles readily dissolves under acidic conditions relevant to wet aerosols. By contrast, under the higher pH conditions generally relevant to clouds, Fe dissolution tends to stop, and dissolved Fe precipitates as poorly crystalline nanoparticles. If the dust-bearing cloud droplets evaporated again (returning to the wet aerosol stage with low pH), those neo-formed Fe nanoparticles quickly redissolve, while the refractory Fe-bearing phases continue to dissolve gradually. Overall, the duration of the acidic, wet aerosol stage ultimately increases the amount of potentially bioavailable Fe delivered to oceans, while conditions in clouds favor the formation of Fe-rich nanoparticles in the atmosphere.

Formation of iron oxides from acid mine drainage and magnetic separation of the heavy metals adsorbed iron oxides

Energy Technology Data Exchange (ETDEWEB)

Kwon, Hee Won; Kim, Jeong Jin; Kim, Young Hun [Andong National University, Andong (Korea, Republic of); Ha, Dong Woo [Korea Electrotechnology Research Institute, Changwon (Korea, Republic of)

2016-03-15

There are a few thousand abandoned metal mines in South Korea. The abandoned mines cause several environmental problems including releasing acid mine drainage (AMD), which contain a very high acidity and heavy metal ions such as Fe, Cu, Cd, Pb, and As. Iron oxides can be formed from the AMD by increasing the solution pH and inducing precipitation. Current study focused on the formation of iron oxide in an AMD and used the oxide for adsorption of heavy metals. The heavy metal adsorbed iron oxide was separated with a superconducting magnet. The duration of iron oxide formation affected on the type of mineral and the degree of magnetization. The removal rate of heavy metal by the adsorption process with the formed iron oxide was highly dependent on the type of iron oxide and the solution pH. A high gradient magnetic separation (HGMS) system successfully separated the iron oxide and harmful heavy metals.

Greek “red mud” residue: A study of microwave reductive roasting followed by magnetic separation for a metallic iron recovery process

Energy Technology Data Exchange (ETDEWEB)

Samouhos, Michail, E-mail: msamouhos@metal.ntua.gr [School of Mining and Metallurgical Engineering, Laboratory of Metallurgy, National Technical University of Athens, 9, Iroon Polytechniou Street, 157 80 Zografou, Athens (Greece); Taxiarchou, Maria; Tsakiridis, Petros E. [School of Mining and Metallurgical Engineering, Laboratory of Metallurgy, National Technical University of Athens, 9, Iroon Polytechniou Street, 157 80 Zografou, Athens (Greece); Potiriadis, Konstantinos [Greek Atomic Energy Commission (GAEC), Patriarxou Grigoriou and Neapoleos, P.O. Box 60092, 15310 Agia Paraskevi, Athens (Greece)

2013-06-15

Highlights: • Microwave reduction of a red mud. •Measurement of real and imaginary permittivity of red mud–lignite mixture. •Red mud was subjected to reductive roasting and magnetic separation processes. •The optimum concentrate contains 31.6% iron with a 69.3% metallization degree. •{sup 226}Ra, {sup 228}Ra, {sup 238}U, {sup 228}Th, {sup 232}Th, {sup 40}K were detected in the magnetic concentrate. -- Abstract: The present research work is focused on the development of an alternative microwave reductive roasting process of red mud using lignite (30.15 wt.% C{sub fix}), followed by wet magnetic separation, in order to produce a raw material suitable for sponge or cast iron production. The reduction degree of iron was controlled by both the reductive agent content and the microwave heating time. The reduction followed the Fe{sub 2}O{sub 3} → Fe{sub 3}O{sub 4} → FeO → Fe sequence. The dielectric constants [real (ε′) and imaginary (ε″) permittivities] of red mud–lignite mixture were determined at 2.45 GHz, in the temperature range of 25–1100 °C. The effect of parameters such as temperature, intensity of reducing conditions, intensity of magnetic field and dispersing agent addition rate on the result of both processes was investigated. The phase's transformations in reduction process with microwave heating were determined by X-ray diffraction analysis (XRD) in combination with thermogravimetric/differential thermal analysis (TGA/DTA). The microstructural and morphological characterization of the produced calcines was carried out by scanning electron microscopy (SEM). At the optimum conditions a magnetic concentrate with total iron concentration of 35.15 and 69.3 wt.% metallization degree was obtained.

Iron stocks of buried Podzols: Endogenic iron deficits and potential exogenic enrichment in the Maashorst region, SE Netherlands

NARCIS (Netherlands)

van Mourik, J.M.; de Vet, S.J.

2015-01-01

Podzolation is the dominant soil forming process in chemical poor sandy soils. It iswell studied howiron concentrations of podzols are effected by translocation of active iron fromeluvial to illuvial horizons and leaching to the aquifer. Iron stocks of Podzols, in contrasts, have not been widely

Genomic insights into microbial iron oxidation and iron uptake strategies in extremely acidic environments.

Science.gov (United States)

Bonnefoy, Violaine; Holmes, David S

2012-07-01

This minireview presents recent advances in our understanding of iron oxidation and homeostasis in acidophilic Bacteria and Archaea. These processes influence the flux of metals and nutrients in pristine and man-made acidic environments such as acid mine drainage and industrial bioleaching operations. Acidophiles are also being studied to understand life in extreme conditions and their role in the generation of biomarkers used in the search for evidence of existing or past extra-terrestrial life. Iron oxidation in acidophiles is best understood in the model organism Acidithiobacillus ferrooxidans. However, recent functional genomic analysis of acidophiles is leading to a deeper appreciation of the diversity of acidophilic iron-oxidizing pathways. Although it is too early to paint a detailed picture of the role played by lateral gene transfer in the evolution of iron oxidation, emerging evidence tends to support the view that iron oxidation arose independently more than once in evolution. Acidic environments are generally rich in soluble iron and extreme acidophiles (e.g. the Leptospirillum genus) have considerably fewer iron uptake systems compared with neutrophiles. However, some acidophiles have been shown to grow as high as pH 6 and, in the case of the Acidithiobacillus genus, to have multiple iron uptake systems. This could be an adaption allowing them to respond to different iron concentrations via the use of a multiplicity of different siderophores. Both Leptospirillum spp. and Acidithiobacillus spp. are predicted to synthesize the acid stable citrate siderophore for Fe(III) uptake. In addition, both groups have predicted receptors for siderophores produced by other microorganisms, suggesting that competition for iron occurs influencing the ecophysiology of acidic environments. Little is known about the genetic regulation of iron oxidation and iron uptake in acidophiles, especially how the use of iron as an energy source is balanced with its need to take up

Iron absorption in relation to iron status

International Nuclear Information System (INIS)

Magnusson, B.; Bjoern-Rasmussen, E.; Hallberg, L.; Rossander, L.

1981-01-01

The absorption from a 3 mg dose of ferrous iron was measured in 250 male subjects. The absorption was related to the log concentration of serum ferritin in 186 subjects of whom 99 were regular blood donors (r= -0.76), and to bone marrow haemosiderin grading in 52 subjects with varying iron status. The purpose was to try and establish a percentage absorption from such a dose that is representative of subjects who are borderline iron deficient. This information is necessary for food iron absorption studies in order (1) to calculate the absorption of iron from the diet at a given iron status and (2) compare the absorption of iron from different meals studied in different groups of subjects by different investigarors. The results suggest that an absorption of about 40% of a 3 mg reference dose of ferrous iron is given in a fasting state, roughly corresponds to the absorption in borderline-iron-deficient subjects. The results indicate that this 40% absorption value corresponds to a serum ferritin level of 30 μg/l and that food iron absorption in a group of subjects should be expressed preferably as the absorption corresponding to a reference-dose absorption of 45%, or possibly a serum ferritin level of 30 μg/l. (author)

Accelerated dissolution of iron oxides in ice

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D. Jeong

2012-11-01

Full Text Available Iron dissolution from mineral dusts and soil particles is vital as a source of bioavailable iron in various environmental media. In this work, the dissolution of iron oxide particles trapped in ice was investigated as a new pathway of iron supply. The dissolution experiments were carried out in the absence and presence of various organic complexing ligands under dark condition. In acidic pH conditions (pH 2, 3, and 4, the dissolution of iron oxides was greatly enhanced in the ice phase compared to that in water. The dissolved iron was mainly in the ferric form, which indicates that the dissolution is not a reductive process. The extent of dissolved iron was greatly affected by the kind of organic complexing ligands and the surface area of iron oxides. The iron dissolution was most pronounced with high surface area iron oxides and in the presence of strong iron binding ligands. The enhanced dissolution of iron oxides in ice is mainly ascribed to the "freeze concentration effect", which concentrates iron oxide particles, organic ligands, and protons in the liquid like ice grain boundary region and accelerates the dissolution of iron oxides. The ice-enhanced dissolution effect gradually decreased when decreasing the freezing temperature from −10 to −196 °C, which implies that the presence and formation of the liquid-like ice grain boundary region play a critical role. The proposed phenomenon of enhanced dissolution of iron oxides in ice may provide a new pathway of bioavailable iron production. The frozen atmospheric ice with iron-containing dust particles in the upper atmosphere thaws upon descending and may provide bioavailable iron upon deposition onto the ocean surface.

An iron-57 Moessbauer spectroscopic study of titania-supported iron- and iron-iridium catalysts

International Nuclear Information System (INIS)

Berry, F.J.; Jobson, S.

1992-01-01

57 Fe Moessbauer spectroscopy shows that titania-supported iron is reduced by treatment in hydrogen at significantly lower temperatures than corresponding silica- and alumina-supported catalysts. The metallic iron formed under hydrogen at 600deg C is partially converted to carbide by treatment in carbon monoxide and hydrogen. In contrast to its alumina- and silica-supported counterparts, the remainder of the titania-supported iron is unchanged by this gaseous mixture. The 57 Fe Moessbauer spectra of EXAFS show that iron and iridium in the titania-supported iron-iridium catalysts are reduced in hydrogen at even lower temperatures and, after treatment at 600deg C, are predominantly present as the iron-iridium alloy. The treatment of these reduced catalysts in carbon monoxide and hydrogen is shown by Moessbauer spectroscopy and EXAFS to induce the segregation of iron from the iron-iridium alloy and its conversion to iron oxide. (orig.)

Immunity to plant pathogens and iron homeostasis.

Science.gov (United States)

Aznar, Aude; Chen, Nicolas W G; Thomine, Sebastien; Dellagi, Alia

2015-11-01

Iron is essential for metabolic processes in most living organisms. Pathogens and their hosts often compete for the acquisition of this nutrient. However, iron can catalyze the formation of deleterious reactive oxygen species. Hosts may use iron to increase local oxidative stress in defense responses against pathogens. Due to this duality, iron plays a complex role in plant-pathogen interactions. Plant defenses against pathogens and plant response to iron deficiency share several features, such as secretion of phenolic compounds, and use common hormone signaling pathways. Moreover, fine tuning of iron localization during infection involves genes coding iron transport and iron storage proteins, which have been shown to contribute to immunity. The influence of the plant iron status on the outcome of a given pathogen attack is strongly dependent on the nature of the pathogen infection strategy and on the host species. Microbial siderophores emerged as important factors as they have the ability to trigger plant defense responses. Depending on the plant species, siderophore perception can be mediated by their strong iron scavenging capacity or possibly via specific recognition as pathogen associated molecular patterns. This review highlights that iron has a key role in several plant-pathogen interactions by modulating immunity. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

The mutual co-regulation of extracellular polymeric substances and iron ions in biocorrosion of cast iron pipes.

Science.gov (United States)

Jin, Juntao; Guan, Yuntao

2014-10-01

New insights into the biocorrosion process may be gained through understanding of the interaction between extracellular polymeric substances (EPS) and iron. Herein, the effect of iron ions on the formation of biofilms and production of EPS was investigated. Additionally, the impact of EPS on the corrosion of cast iron coupons was explored. The results showed that a moderate concentration of iron ions (0.06 mg/L) promoted both biofilm formation and EPS production. The presence of EPS accelerated corrosion during the initial stage, while inhibited corrosion at the later stage. The functional groups of EPS acted as electron shuttles to enable the binding of iron ions. Binding of iron ions with EPS led to anodic dissolution and promoted corrosion, while corrosion was later inhibited through oxygen reduction and availability of phosphorus from EPS. The presence of EPS also led to changes in crystalline phases of corrosion products. Copyright © 2014 Elsevier Ltd. All rights reserved.

MATHEMATICAL MODELING AND NUMERICAL SOLUTION OF IRON CORROSION PROBLEM BASED ON CONDENSATION CHEMICAL PROPERTIES

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Basuki Widodo

2012-02-01

Full Text Available Corrosion process is a natural case that happened at the various metals, where the corrosion process in electrochemical can be explained by using galvanic cell. The iron corrosion process is based on the acidity degree (pH of a condensation, iron concentration and condensation temperature of electrolyte. Those are applied at electrochemistry cell. The iron corrosion process at this electrochemical cell also able to generate electrical potential and electric current during the process takes place. This paper considers how to build a mathematical model of iron corrosion, electrical potential and electric current. The mathematical model further is solved using the finite element method. This iron corrosion model is built based on the iron concentration, condensation temperature, and iteration time applied. In the electric current density model, the current based on electric current that is happened at cathode and anode pole and the iteration time applied. Whereas on the potential  electric model, it is based on the beginning of electric potential and the iteration time applied. The numerical results show that the part of iron metal, that is gristle caused by corrosion, is the part of metal that has function as anode and it has some influences, such as time depth difference, iron concentration and condensation temperature on the iron corrosion process and the sum of reduced mass during corrosion process. Moreover, difference influence of time and beginning electric potential has an effect on the electric potential, which emerges during corrosion process at the electrochemical cell. Whereas, at the electrical current is also influenced by difference of depth time and condensation temperature applied.Keywords: Iron Corrosion, Concentration of iron, Electrochemical Cell and Finite Element Method

Colour Metallography of Cast Iron - Chapter 1: Introduction (Ⅰ

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Zhou Jiyang

2009-02-01

Full Text Available Cast iron, as a traditional metal material, has advantages of low total cost, good castability and machinability, good wear resistance and low notch sensitivity, and is still facing tough challenge in quality, property and variety of types etc. Experts and engineers studying and producing iron castings all around world extremely concern this serious challenge. Over more than 30 years, a great of research work has been carried out on how to further improve its property, expand its application and combine cast iron technology with some hi-techs (for example, computer technology. Nevertheless, cast iron is a multi-element and multi-phase alloy and has complex and variety of structures and still has great development potential in structure and property. For further studying and developing cast iron, theoretical research work is important promise, and the study on solidification process and control mechanism of graphite morphology is fundamental for improving property of cast iron and developing new type of cast iron. Metallography of cast iron normally includes two sections: liquid phase transformation and solid phase transformation. The book, Colour Metallography of Cast Iron, uses colour metallography technique to study solidification structures of cast irons: graphite, carbides, austenite and eutectics; and focuses on solidification processes. With progress of modern solidification theory, the control of material solidification process becomes important measure for improving traditional materials and developing new materials. Solidification structure not only influences mechanical and physical properties of cast iron, but also affects its internal quality. The book uses a large amount of colour photos to describe the formation of solidification structures and their relations. Crystallization phenomena, which cannot be displayed with traditional metallography, are presented and more phase transformation information is obtained from these colour

In Situ Investigation of the Iron Carbide Precipitation Process in a Fe-C-Mn-Si Q&P Steel

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Sébastien Y. P. Allain

2018-06-01

Full Text Available Quenching and Partitioning (Q&P steels are promising candidates for automotive applications because of their lightweight potential. Their properties depend on carbon enrichment in austenite which, in turn, is strongly influenced by carbide precipitation in martensite during quenching and partitioning treatment. In this paper, by coupling in situ High Energy X-Ray Diffraction (HEXRD experiments and Transmission Electron Microscopy (TEM, we give some clarification regarding the precipitation process of iron carbides in martensite throughout the Q&P process. For the first time, precipitation kinetics was followed in real time. It was shown that precipitation starts during the reheating sequence for the steel studied. Surprisingly, the precipitated fraction remains stable all along the partitioning step at 400 °C. Furthermore, the analyses enable the conclusion that the iron carbides are most probably eta carbides. The presence of cementite was ruled out, while the presence of several epsilon carbides cannot be strictly excluded.

Effect of iron salt counter ion in dose-response curves for inactivation of Fusarium solani in water through solar driven Fenton-like processes

Science.gov (United States)

Aurioles-López, Verónica; Polo-López, M. Inmaculada; Fernández-Ibáñez, Pilar; López-Malo, Aurelio; Bandala, Erick R.

2016-02-01

The inactivation of Fusarium solani in water was assessed by solar driven Fenton-like processes using three different iron salts: ferric acetylacetonate (Fe(acac)3), ferric chloride (FeCl3) and ferrous sulfate (FeSO4). The experimental conditions tested were [Fe] ≈ 5 mg L-1, [H2O2] ≈ 10 mg L-1 and [Fe] ≈ 10 mg L-1; [H2O2] ≈ 20 mg L-1 mild and high, respectively, and pH 3.0 and 5.0, under solar radiation. The highest inactivation rates were observed at high reaction conditions for the three iron salts tested at pH 5.0 with less than 3.0 kJ L-1 of accumulate energy (QUV) to achieve over 99.9% of F. solani inactivation. Fe(acac)3 was the best iron salt to accomplishing F. solani inactivation. The modified Fermi equation was used to fix the experimental inactivation, data showed it was helpful for modeling the process, adequately describing dose-response curves. Inactivation process using FeSO4 at pH 3.0 was modeled fairly with r2 = 0.98 and 0.99 (mild and high concentration, respectively). Fe(acac)3, FeCl3 and FeSO4 at high concentration (i.e. [Fe] ≈ 10 mg L-1; [H2O2] ≈ 20 mg L-1) and pH 5.0 showed the highest fitting values (r2 = 0.99). Iron salt type showed a remarkable influence on the Fenton-like inactivation process.

Regulation of iron metabolism during Neisseria meningitidis infection in mice

Energy Technology Data Exchange (ETDEWEB)

Letendre, E.D.

1984-01-01

Bacterial invasion of vertebrates triggers a marked reduction in the levels of iron associated with the plasma transferrin (Tf) pool. This hypoferremic response has been regarded as a host attempt to withhold essential iron from the invading pathogen. The exact nature of the mechanisms involved remains obscure. The kinetics of iron processing by the RE system were studied by labeling the RE compartments with /sup 59/Fe-labeled denatured red blood cells. Uptake and redistribution of the label indicated the RE-processed iron was not returned to the plasma Tf pool during the hypoferremia. Fractionation of hepatic cellular compartments showed that this impaired release of iron resulted from a preferential incorporation of home-derived iron into the intracellular ferritin pool and this produces the hypoferremia. The role of ceruloplasmin (ferroxidase I,EC.1.16.3.1) (Cp) in iron metabolism during meningococcal infection was investigated. Plasma Cp ferroxidase activity was found to increase greatly in mice during the convalescence phase.

The liver in regulation of iron homeostasis.

Science.gov (United States)

Rishi, Gautam; Subramaniam, V Nathan

2017-09-01

The liver is one of the largest and most functionally diverse organs in the human body. In addition to roles in detoxification of xenobiotics, digestion, synthesis of important plasma proteins, gluconeogenesis, lipid metabolism, and storage, the liver also plays a significant role in iron homeostasis. Apart from being the storage site for excess body iron, it also plays a vital role in regulating the amount of iron released into the blood by enterocytes and macrophages. Since iron is essential for many important physiological and molecular processes, it increases the importance of liver in the proper functioning of the body's metabolism. This hepatic iron-regulatory function can be attributed to the expression of many liver-specific or liver-enriched proteins, all of which play an important role in the regulation of iron homeostasis. This review focuses on these proteins and their known roles in the regulation of body iron metabolism. Copyright © 2017 the American Physiological Society.

Coal fly ash as a source of iron in atmospheric dust.

Science.gov (United States)

Chen, Haihan; Laskin, Alexander; Baltrusaitis, Jonas; Gorski, Christopher A; Scherer, Michelle M; Grassian, Vicki H

2012-02-21

Anthropogenic coal fly ash (FA) aerosol may represent a significant source of bioavailable iron in the open ocean. Few measurements have been made that compare the solubility of atmospheric iron from anthropogenic aerosols and other sources. We report here an investigation of iron dissolution for three FA samples in acidic aqueous solutions and compare the solubilities with that of Arizona test dust (AZTD), a reference material for mineral dust. The effects of pH, simulated cloud processing, and solar radiation on iron solubility have been explored. Similar to previously reported results on mineral dust, iron in aluminosilicate phases provides the predominant component of dissolved iron. Iron solubility of FA is substantially higher than of the crystalline minerals comprising AZTD. Simulated atmospheric processing elevates iron solubility due to significant changes in the morphology of aluminosilicate glass, a dominant material in FA particles. Iron is continuously released into the aqueous solution as FA particles break up into smaller fragments. These results suggest that the assessment of dissolved atmospheric iron deposition fluxes and their effect on the biogeochemistry at the ocean surface should be constrained by the source, environmental pH, iron speciation, and solar radiation.

Iron sponge installation clicks at Retlaw plant

Energy Technology Data Exchange (ETDEWEB)

1965-06-21

Iron sponge desulfurization, often ignored by plant designers in favor of the monoethanolamine process, may offer economic advantages in sweetening of small gas volumes with low hydrogen sulfide and carbon dioxide content. The process removes hydrogen sulfide and mercaptans by passing sour gas through vessels loosely packed with wood shavings impregnated by a hydrated form of iron oxide, which reacts with the hydrogen sulfide to form ferric sulfide. The disadvantages are that carbon dioxide is not removed, hydrate formation is a danger in cold weather, and gas sales may be lost when towers are down for servicing. Periodic regeneration of beds takes about a day, and sponges must be replaced occasionally. Despite these shortcomings, the process may prove economical, since a typical plant costs $110,000 as compared to $270,000 for an amine unit. The expense of operating the plant is $23,000 compared with $28,000 for the amine unit. Thus, economics clearly favor the iron sponge process.

Synthesis of iron oxide nanoparticles via sonochemical method and their characterization

Institute of Scientific and Technical Information of China (English)

Amir Hassanjani-Roshan; Mohammad Reza Vaezi; Ali Shokuhfar; Zohreh Rajabali

2011-01-01

Preparation of iron oxide (α-Fe2O3) nanoparticles was carried out via a sonochemical process. The process parameters such as temperature,sonication time and power of ultrasonication play important roles in the size and morphology of the final products. The iron oxide nanoparticles were characterized by transmission electron microscopy,X-ray powder diffraction,and thermogravimetric and differential thermal analyses. From transmission electron microscopy observations,the size of the iron oxide nanoparticles is estimated to be significantly smaller than 19 nm. X-ray diffraction data of the powder after annealing provide direct evidence that the iron oxide was formed during the sonochemical process.

U-shaped curve for risk associated with maternal hemoglobin, iron status, or iron supplementation.

Science.gov (United States)

Dewey, Kathryn G; Oaks, Brietta M

2017-12-01

Both iron deficiency (ID) and excess can lead to impaired health status. There is substantial evidence of a U-shaped curve between the risk of adverse birth outcomes and maternal hemoglobin concentrations during pregnancy; however, it is unclear whether those relations are attributable to conditions of low and high iron status or to other mechanisms. We summarized current evidence from human studies regarding the association between birth outcomes and maternal hemoglobin concentrations or iron status. We also reviewed effects of iron supplementation on birth outcomes among women at low risk of ID and the potential mechanisms for adverse effects of high iron status during pregnancy. Overall, we confirmed a U-shaped curve for the risk of adverse birth outcomes with maternal hemoglobin concentrations, but the relations differ by trimester. For low hemoglobin concentrations, the link with adverse outcomes is more evident when hemoglobin concentrations are measured in early pregnancy. These relations generally became weaker or nonexistent when hemoglobin concentrations are measured in the second or third trimesters. Associations between high hemoglobin concentration and adverse birth outcomes are evident in all 3 trimesters but evidence is mixed. There is less evidence for the associations between maternal iron status and adverse birth outcomes. Most studies used serum ferritin (SF) concentrations as the indicator of iron status, which makes the interpretation of results challenging because SF concentrations increase in response to inflammation or infection. The effect of iron supplementation during pregnancy may depend on initial iron status. There are several mechanisms through which high iron status during pregnancy may have adverse effects on birth outcomes, including oxidative stress, increased blood viscosity, and impaired systemic response to inflammation and infection. Research is needed to understand the biological processes that underlie the U-shaped curves

Iron isotope biogeochemistry of Neoproterozoic marine shales

Science.gov (United States)

Kunzmann, Marcus; Gibson, Timothy M.; Halverson, Galen P.; Hodgskiss, Malcolm S. W.; Bui, Thi Hao; Carozza, David A.; Sperling, Erik A.; Poirier, André; Cox, Grant M.; Wing, Boswell A.

2017-07-01

Iron isotopes have been widely applied to investigate the redox evolution of Earth's surface environments. However, it is still unclear whether iron cycling in the water column or during diagenesis represents the major control on the iron isotope composition of sediments and sedimentary rocks. Interpretation of isotopic data in terms of oceanic redox conditions is only possible if water column processes dominate the isotopic composition, whereas redox interpretations are less straightforward if diagenetic iron cycling controls the isotopic composition. In the latter scenario, iron isotope data is more directly related to microbial processes such as dissimilatory iron reduction. Here we present bulk rock iron isotope data from late Proterozoic marine shales from Svalbard, northwestern Canada, and Siberia, to better understand the controls on iron isotope fractionation in late Proterozoic marine environments. Bulk shales span a δ 56Fe range from -0.45 ‰ to +1.04 ‰ . Although δ 56Fe values show significant variation within individual stratigraphic units, their mean value is closer to that of bulk crust and hydrothermal iron in samples post-dating the ca. 717-660 Ma Sturtian glaciation compared to older samples. After correcting for the highly reactive iron content in our samples based on iron speciation data, more than 90% of the calculated δ 56Fe compositions of highly reactive iron falls in the range from ca. -0.8 ‰ to +3 ‰ . An isotope mass-balance model indicates that diagenetic iron cycling can only change the isotopic composition of highly reactive iron by control the isotopic composition of highly reactive iron. Considering a long-term decrease in the isotopic composition of the iron source to the dissolved seawater Fe(II) reservoir to be unlikely, we offer two possible explanations for the Neoproterozoic δ 56Fe trend. First, a decreasing supply of Fe(II) to the ferrous seawater iron reservoir could have caused the reservoir to decrease in size

Influence of the Moisture Content on the Flowability of Fine-Grained Iron Ore Concentrate

OpenAIRE

C. Lanzerstorfer; M. Hinterberger

2017-01-01

The iron content of the ore used is crucial for the productivity and coke consumption rate in blast furnace pig iron production. Therefore, most iron ore deposits are processed in beneficiation plants to increase the iron content and remove impurities. In several comminution stages, the particle size of the ore is reduced to ensure that the iron oxides are physically liberated from the gangue. Subsequently, physical separation processes are applied to concentrate the iron ore. The fine-graine...

A systematic study of the controlled generation of crystalline iron oxide nanoparticles on graphene using a chemical etching process

Directory of Open Access Journals (Sweden)

Peter Krauß

2017-09-01

Full Text Available Chemical vapor deposition (CVD of carbon precursors employing a metal catalyst is a well-established method for synthesizing high-quality single-layer graphene. Yet the main challenge of the CVD process is the required transfer of a graphene layer from the substrate surface onto a chosen target substrate. This process is delicate and can severely degrade the quality of the transferred graphene. The protective polymer coatings typically used generate residues and contamination on the ultrathin graphene layer. In this work, we have developed a graphene transfer process which works without a coating and allows the transfer of graphene onto arbitrary substrates without the need for any additional post-processing. During the course of our transfer studies, we found that the etching process that is usually employed can lead to contamination of the graphene layer with the Faradaic etchant component FeCl3, resulting in the deposition of iron oxide FexOy nanoparticles on the graphene surface. We systematically analyzed the removal of the copper substrate layer and verified that crystalline iron oxide nanoparticles could be generated in controllable density on the graphene surface when this process is optimized. It was further confirmed that the FexOy particles on graphene are active in the catalytic growth of carbon nanotubes when employing a water-assisted CVD process.

Iron economy in Naegleria gruberi reflects its metabolic flexibility.

Science.gov (United States)

Mach, Jan; Bíla, Jarmila; Ženíšková, Kateřina; Arbon, Dominik; Malych, Ronald; Glavanakovová, Marie; Nývltová, Eva; Sutak, Robert

2018-05-05

Naegleria gruberi is a free-living amoeba, closely related to the human pathogen Naegleria fowleri, the causative agent of the deadly human disease primary amoebic meningoencephalitis. Herein, we investigated the effect of iron limitation on different aspects of N. gruberi metabolism. Iron metabolism is among the most conserved pathways found in all eukaryotes. It includes the delivery, storage and utilisation of iron in many cell processes. Nevertheless, most of the iron metabolism pathways of N. gruberi are still not characterised, even though iron balance within the cell is crucial. We found a single homolog of ferritin in the N. gruberi genome and showed its localisation in the mitochondrion. Using comparative mass spectrometry, we identified 229 upregulated and 184 down-regulated proteins under iron-limited conditions. The most down-regulated protein under iron-limited conditions was hemerythrin, and a similar effect on the expression of hemerythrin was found in N. fowleri. Among the other down-regulated proteins were [FeFe]-hydrogenase and its maturase HydG and several heme-containing proteins. The activities of [FeFe]-hydrogenase, as well as alcohol dehydrogenase, were also decreased by iron deficiency. Our results indicate that N. gruberi is able to rearrange its metabolism according to iron availability, prioritising mitochondrial pathways. We hypothesise that the mitochondrion is the center for iron homeostasis in N. gruberi, with mitochondrially localised ferritin as a potential key component of this process. Copyright © 2018 Australian Society for Parasitology. Published by Elsevier Ltd. All rights reserved.

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.

Higher iron bioavailability of a human-like collagen iron complex.

Science.gov (United States)

Zhu, Chenhui; Yang, Fan; Fan, Daidi; Wang, Ya; Yu, Yuanyuan

2017-07-01

Iron deficiency remains a public health problem around the world due to low iron intake and/or bioavailability. FeSO 4 , ferrous succinate, and ferrous glycinate chelate are rich in iron but have poor bioavailability. To solve the problem of iron deficiency, following previous research studies, a thiolated human-like collagen-ironcomplex supplement with a high iron content was prepared in an anaerobic workstation. In addition, cell viability tests were evaluated after conducting an MTT assay, and a quantitative analysis of the thiolated human-like collagen-iron digesta samples was performed using the SDS-PAGE method coupled with gel filtration chromatography. The iron bioavailability was assessed using Caco-2 cell monolayers and iron-deficiency anemia mice models. The results showed that (1) one mole of thiolated human-like collagen-iron possessed approximately 35.34 moles of iron; (2) thiolated human-like collagen-iron did not exhibit cytotoxity and (3) thiolated human-like collagen- iron digesta samples had higher bioavailability than other iron supplements, including FeSO 4 , ferrous succinate, ferrous glycine chelate and thiolated human-like collagen-Fe iron. Finally, the iron bioavailability was significantly enhanced by vitamin C. These results indicated that thiolated human-like collagen-iron is a promising iron supplement for use in the future.

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.

The impact of steeping, germination and hydrothermal processing of wheat (Triticum aestivum L.) grains on phytate hydrolysis and the distribution, speciation and bio-accessibility of iron and zinc elements.

Science.gov (United States)

Lemmens, Elien; De Brier, Niels; Spiers, Kathryn M; Ryan, Chris; Garrevoet, Jan; Falkenberg, Gerald; Goos, Peter; Smolders, Erik; Delcour, Jan A

2018-10-30

Chelation of iron and zinc in wheat as phytates lowers their bio-accessibility. Steeping and germination (15 °C, 120 h) lowered phytate content from 0.96% to only 0.81% of initial dry matter. A multifactorial experiment in which (steeped/germinated) wheat was subjected to different time (2-24 h), temperature (20-80 °C) and pH (2.0-8.0) conditions showed that hydrothermal processing of germinated (15 °C, 120 h) wheat at 50 °C and pH 3.8 for 24 h reduced phytate content by 95%. X-ray absorption near-edge structure imaging showed that it indeed abolished chelation of iron to phytate. It also proved that iron was oxidized during steeping, germination and hydrothermal processing. It was further shown that zinc and iron bio-accessibility were respectively 3 and 5% in wheat and 27 and 37% in hydrothermally processed wheat. Thus, hydrothermal processing of (germinated) wheat paves the way for increasing elemental bio-accessibility in whole grain-based products. Copyright © 2018 Elsevier Ltd. All rights reserved.

The Efficiency of Strontium-90 Desorption Using Iron (III) Solutions in the Decontamination Process of Radioactive Soils

OpenAIRE

Olga Vladimirovna Cheremisina; Vasiliy Sergeev; Varvara Alabusheva; Alexander Fedorov; Alexandra Iliyna

2018-01-01

The paper presents the investigation on the estimated efficiency of iron (III) chloride solutions in the decontamination process of radioactive soils with 90 Sr, according to kinetic and thermodynamic characteristics of the desorption process. The specific 90 Sr radioactivity of soil samples was (3.9±0.3)·104 Bq·g. The adsorption isotherms of Sr 2+ and Fe 3+ are described with the Langmuir equation. The values of Gibbs energy G0298 = -4.65 kJ·mol -1 and equilibrium ion exchange constant ...

Iron turbidity removal from the active process water system of the Kaiga Generating Station Unit 1 using an electrochemical filter

International Nuclear Information System (INIS)

Venkateswaran, G.; Gokhale, B.K.

2007-01-01

Iron turbidity is observed in the intermediate cooling circuit of the active process water system (APWS) of Kaiga Generating Station (KGS). Deposition of hydrous/hydrated oxides of iron on the plate type heat exchanger, which is employed to transfer heat from the APWS to the active process cooling water system (APCWS), can in turn result in higher moderator D 2 O temperatures due to reduced heat transfer. Characterization of turbidity showed that the major component is γ-FeOOH. An in-house designed and fabricated electrochemical filter (ECF) containing an alternate array of 33 pairs of cathode and anode graphite felts was successfully tested for the removal of iron turbidity from the APWS of Kaiga Generating Station Unit No. 1 (KGS No. 1). A total volume of 52.5 m 3 water was processed using the filter. At an average inlet turbidity of 5.6 nephelometric turbidity units (NTU), the outlet turbidity observed from the ECF was 1.6 NTU. A maximum flow rate (10 L . min -1 ) and applied potential of 18.0-20.0 V was found to yield an average turbidity-removal efficiency of ∝ 75 %. When the experiment was terminated, a throughput of > 2.08 . 10 5 NTU-liters was realized without any reduction in the removal efficiency. Removal of the internals of the filter showed that only the bottom 11 pairs of felts had brownish deposits, while the remaining felts looked clean and unused. (orig.)

Hepcidin: A Critical Regulator of Iron Metabolism during Hypoxia

Directory of Open Access Journals (Sweden)

Korry J. Hintze

2011-01-01

Full Text Available Iron status affects cognitive and physical performance in humans. Recent evidence indicates that iron balance is a tightly regulated process affected by a series of factors other than diet, to include hypoxia. Hypoxia has profound effects on iron absorption and results in increased iron acquisition and erythropoiesis when humans move from sea level to altitude. The effects of hypoxia on iron balance have been attributed to hepcidin, a central regulator of iron homeostasis. This paper will focus on the molecular mechanisms by which hypoxia affects hepcidin expression, to include a review of the hypoxia inducible factor (HIF/hypoxia response element (HRE system, as well as recent evidence indicating that localized adipose hypoxia due to obesity may affect hepcidin signaling and organismal iron metabolism.

Theoretical Investigation of Hydrogen Adsorption and Dissociation on Iron and Iron Carbide Surfaces Using the ReaxFF Reactive Force Field Method

Energy Technology Data Exchange (ETDEWEB)

Zou, Chenyu; van Duin, Adri C.T.; Sorescu, Dan C.

2012-06-01

We have developed a ReaxFF reactive force field to describe hydrogen adsorption and dissociation on iron and iron carbide surfaces relevant for simulation of Fischer–Tropsch (FT) synthesis on iron catalysts. This force field enables large system (>>1000 atoms) simulations of hydrogen related reactions with iron. The ReaxFF force field parameters are trained against a substantial amount of structural and energetic data including the equations of state and heats of formation of iron and iron carbide related materials, as well as hydrogen interaction with iron surfaces and different phases of bulk iron. We have validated the accuracy and applicability of ReaxFF force field by carrying out molecular dynamics simulations of hydrogen adsorption, dissociation and recombination on iron and iron carbide surfaces. The barriers and reaction energies for molecular dissociation on these two types of surfaces have been compared and the effect of subsurface carbon on hydrogen interaction with iron surface is evaluated. We found that existence of carbon atoms at subsurface iron sites tends to increase the hydrogen dissociation energy barrier on the surface, and also makes the corresponding hydrogen dissociative state relatively more stable compared to that on bare iron. These properties of iron carbide will affect the dissociation rate of H{sub 2} and will retain more surface hydride species, thus influencing the dynamics of the FT synthesis process.

An investigation of air emission levels from distinct iron and steel production processes with the adoption of pollution control and pollution prevention alternatives

International Nuclear Information System (INIS)

Costa, M.M.; Schaeffer, R.

1999-01-01

This paper aims to investigate environmental aspects from different iron and steel production processes. A methodology based on material flows is developed in order to verify some air emission levels attained by Pollution Control and Pollution Prevention alternatives. The data basis for modeling energy and materials flows in iron and steel production is obtained from a literature review on different technological processes, energy and materials consumption and pollutant releases to the environmental Modeling combines both process analysis and input-output techniques to simulate the different iron and steel production routes and to estimate the resulting total atmospheric pollution releases based on air emission factors for several pollutants by each production step. Processes examined include: (1) Conventional Integrated (100% ore-based and partly scrap-based); (2) Mini-mill with EAF (100% scrap-based and partly DRI-based); and (3) New Integrated based on the COREX smelting reduction process. Among the alternatives considered for air emissions reductions are those related to Pollution Control (mainly gas cleaning systems) and to Pollution Prevention (change/reduction in input materials, operational procedures and housekeeping improvements, on-site recycling and technology innovations and modifications). Results indicate higher air pollution intensity for the Conventional Integrated Route over the Mini-mill with EAF and COREX smelting reduction processes, though pointing out that final figures are strongly affected by the systems' boundaries and the different air emission levels of each production step

Effect of zero-valent iron and trivalent iron on UASB rapid start-up.

Science.gov (United States)

Wang, Jie; Fang, Hongyan; Jia, Hui; Yang, Guang; Gao, Fei; Liu, Wenbin

2018-01-01

In order to realize the rapid start-up of upflow anaerobic sludge blanket (UASB) reactor, the iron ion in different valence state was added to UASB. The results indicated that the start-up time of R3 (FeCl 3 ) was 48 h faster than that of R2 (zero-valent iron (ZVI)). It was because the FeCl 3 could rapidly promote granulation of sludge as a flocculant. However, ZVI released Fe 2+ through corrosion slowly, and then the Fe 2+ increased start-up speed by enhancing enzyme activity and enriching methanogens. In addition, the ZVI and FeCl 3 could promote hydrolysis acidification and strengthen the decomposition of long-chain fatty acids. The detection of iron ions showed that iron ions mainly existed in the sludge. Because the high concentration of Fe 2+ could inhibit anaerobic bacteria activity, excess Fe 3+ could be changed into iron hydroxide precipitation to hinder the mass transfer process of anaerobic bacteria under the alkaline condition. The FeCl 3 was suitable to be added at the initial stage of UASB start-up, and the ZVI was more fitted to be used in the middle stage of reactor start-up to improve the redox ability.

Iron

Science.gov (United States)

Iron is a mineral that our bodies need for many functions. For example, iron is part of hemoglobin, a protein which carries ... It helps our muscles store and use oxygen. Iron is also part of many other proteins and ...

A cascade of iron-containing proteins governs the genetic iron starvation response to promote iron uptake and inhibit iron storage in fission yeast.

Directory of Open Access Journals (Sweden)

Javier Encinar del Dedo

2015-03-01

Full Text Available Iron is an essential cofactor, but it is also toxic at high levels. In Schizosaccharomyces pombe, the sensor glutaredoxin Grx4 guides the activity of the repressors Php4 and Fep1 to mediate a complex transcriptional response to iron deprivation: activation of Php4 and inactivation of Fep1 leads to inhibition of iron usage/storage, and to promotion of iron import, respectively. However, the molecular events ruling the activity of this double-branched pathway remained elusive. We show here that Grx4 incorporates a glutathione-containing iron-sulfur cluster, alone or forming a heterodimer with the BolA-like protein Fra2. Our genetic study demonstrates that Grx4-Fra2, but not Fep1 nor Php4, participates not only in iron starvation signaling but also in iron-related aerobic metabolism. Iron-containing Grx4 binds and inactivates the Php4 repressor; upon iron deprivation, the cluster in Grx4 is probably disassembled, the proteins dissociate, and Php4 accumulates at the nucleus and represses iron consumption genes. Fep1 is also an iron-containing protein, and the tightly bound iron is required for transcriptional repression. Our data suggest that the cluster-containing Grx4-Fra2 heterodimer constitutively binds to Fep1, and upon iron deprivation the disassembly of the iron cluster between Grx4 and Fra2 promotes reverse metal transfer from Fep1 to Grx4-Fra2, and de-repression of iron-import genes. Our genetic and biochemical study demonstrates that the glutaredoxin Grx4 independently governs the Php4 and Fep1 repressors through metal transfer. Whereas iron loss from Grx4 seems to be sufficient to release Php4 and allow its nuclear accumulation, total or partial disassembly of the Grx4-Fra2 cluster actively participates in iron-containing Fep1 activation by sequestering its iron and decreasing its interaction with promoters.

Iron modified bentonite: Enhanced adsorption performance for organic pollutant and its regeneration by heterogeneous visible light photo-Fenton process at circumneutral pH

International Nuclear Information System (INIS)

Gao, Yaowen; Guo, Yongzhao; Zhang, Hui

2016-01-01

Highlights: • The iron modification markedly improved the adsorption performance of FeMB for RhB. • LED lamps emitting white light were employed as visible light source. • FeMB can be regenerated by visible light photo-Fenton process at circumneutral pH. • FeMB can be reused repeatedly after the heterogeneous photo-Fenton regeneration. - Abstract: Iron modified bentonite (FeMB) was prepared and used as an inexpensive adsorbent to rapidly remove organic pollutant (Rhodamine B, RhB) from aqueous solution. The iron modification significantly improved the adsorption performance of FeMB for RhB and permitted an easy separation of FeMB from the treated effluent. The equilibrium adsorption studies indicated that the dye molecules obeyed Langmuir type of adsorption with the calculated maximum adsorption capacity of 168.13 mg g"−"1 for FeMB. The heterogeneous photo-Fenton process operated at circumneutral pH in the presence of visible light irradiation was found to be effective for the regeneration of the spent FeMB. Furthermore, the regeneration efficiency of as high as 79% was still achieved after 5 consecutive adsorption-regeneration cycles. Considering that, the visible light photo-Fenton approach could be applied as an excellent alternative for regenerating clay-based adsorbents by avoiding the use of dissolved iron salts.

Dietary iron intake, iron status, and gestational diabetes.

Science.gov (United States)

Zhang, Cuilin; Rawal, Shristi

2017-12-01

Pregnant women are particularly vulnerable to iron deficiency and related adverse pregnancy outcomes and, as such, are routinely recommended for iron supplementation. Emerging evidence from both animal and population-based studies, however, has raised potential concerns because significant associations have been observed between greater iron stores and disturbances in glucose metabolism, including increased risk of type 2 diabetes among nonpregnant individuals. Yet, the evidence is uncertain regarding the role of iron in the development of gestational diabetes mellitus (GDM), a common pregnancy complication which has short-term and long-term adverse health ramifications for both women and their children. In this review, we critically and systematically evaluate available data examining the risk of GDM associated with dietary iron, iron supplementation, and iron status as measured by blood concentrations of several indicators. We also discuss major methodologic concerns regarding the available epidemiologic studies on iron and GDM. © 2017 American Society for Nutrition.

Studies on the pathogenesis in iron deficiency anemia Part 1. Urinary iron excretion in iron deficiency anemia patients and rats in various iron states

OpenAIRE

中西,徳彦

1991-01-01

In the "iron excretion test" , urinary iron excretion after injection of saccharated iron oxide has been reported to be accelerated in relapsing idiopathic iron deficiency anemia. To determine the relevance of urinary iron excretion to clinical factors other than iron metabolism, 15 clinical parameters were evaluated. The serum creatinine level was positively and the serum albumin level was negatively correlated with urinary iron excretion, showing coefficients of r＝0.97,－0.86 respectively, a...

Formation mechanisms of periodic longitudinal microstructure and texture patterns in friction stir welded magnesium AZ80

Energy Technology Data Exchange (ETDEWEB)

Hiscocks, J., E-mail: j.hiscocks@queensu.ca [Department of Mechanical and Materials Engineering, Queen' s University, Kingston, Ontario (Canada); Diak, B.J. [Department of Mechanical and Materials Engineering, Queen' s University, Kingston, Ontario (Canada); Gerlich, A.P. [Department of Mechanical and Mechatronics Engineering, Waterloo University, Waterloo, Ontario (Canada); Daymond, M.R. [Department of Mechanical and Materials Engineering, Queen' s University, Kingston, Ontario (Canada)

2016-12-15

Many studies of friction stir welding have shown that periodicity of metal flow around the tool pin may result in the formation of periodic differences in microstructure and texture in the weld nugget area correlated with the weld pitch. The current work investigates the periodicity of magnesium weld microtexture in the nugget region and its association with material flow using optical and electron microscopy. Two welds created in AZ80 at different processing conditions are presented in detail, one illustrating periodic longitudinal texture change, and one showing for the first time that periodic variations in texture, grain size, or composition are not defining features of periodic nugget flow. While nugget texture is dominated by shear deformation, it was found here to be affected to a lesser degree by compaction of material behind the welding tool, which led to reduction in intensity of the shear texture fiber. The decreased tendency for magnesium based alloys to form periodic patterns as compared to aluminum based alloys is explained with reference to the shear textures. - Highlights: •It is shown here that periodic material flow in the nugget does not necessitate longitudinal texture patterns. •Longitudinal texture patterns are shown to be present or absent in Mg AZ80 based on processing conditions. •Texture in the nugget is mainly dictated by shear deformation, but has measurable effects from other deformation modes. •Explanation of why longitudinal texture change is frequently reported in aluminum but not magnesium alloys is provided. •A new vector visualization of material flow based on EBSD data analysis is shown.

Delamination wear mechanism in gray cast irons

International Nuclear Information System (INIS)

Salehi, M.

2000-01-01

An investigation of the friction and sliding wear of gray cast iron against chromium plated cast irons was carried out on a newly constructed reciprocating friction and wear tester. The tests were the first to be done on the test rig under dry conditions and at the speed of 170 cm/min, and variable loads of 20-260 N for a duration of 15 min. to 3 hours. The gray cast iron surfaces worn by a process of plastic deformation at the subsurface, crack nucleation, and crack growth leading to formation of plate like debris and therefore the delamination theory applies. No evidence of adhesion was observed. This could be due to formation of oxides on the wear surface which prevent adhesion. channel type chromium plating ''picked'' up cast iron from the counter-body surfaces by mechanically trapping cast iron debris on and within the cracks. The removal of the plated chromium left a pitted surface on the cast iron

Iron from Zealandic bog iron ore -

DEFF Research Database (Denmark)

Lyngstrøm, Henriette Syrach

2011-01-01

og geologiske materiale, metallurgiske analyser og eksperimentel arkæologiske forsøg - konturerne af en jernproduktion med udgangspunkt i den sjællandske myremalm. The frequent application by archaeologists of Werner Christensen’s distribution map for the occurrence of bog iron ore in Denmark (1966...... are sketched of iron production based on bog iron ore from Zealand....

Geochemical investigation of iron transport into bentonite as steel corrodes

International Nuclear Information System (INIS)

Hunter, Fiona; Bate, Fiona; Heath, Tim; Hoch, Andrew

2007-09-01

In Sweden and Finland, it is proposed that spent nuclear fuel will be encapsulated in sealed cylindrical canisters, for disposal in a geologic repository, either in vertical boreholes (KBS-3V) or in long horizontal boreholes (KBS-3H). The canisters will consist of a thick cast iron insert and a copper outer container, and each canister will be surrounded by a compacted bentonite clay buffer. It is important to investigate the possible consequences if a failure of these physical barriers was to occur. For instance, if mechanical failure of the copper outer container were to occur then groundwater could enter the annulus and reach the cast iron insert. This would result in anaerobically corroded iron from the cast iron insert interacting with the bentonite surrounding the canisters. The presence of anaerobically corroded iron in groundwater raises the question of how the bentonite will be affected by this process. In the case of the KBS-3H concept, mechanical failure of the copper outer container could lead to interaction between anaerobically corroded iron and bentonite, as above. However, direct contact between anaerobically corroding carbon steel and bentonite is also likely because of the presence of perforated carbon steel support structures in the long horizontal boreholes. As part of the NF-PRO project, an extensive experimental programme has been carried out over several years to study the interactions between anaerobically corroding carbon steel or cast iron and bentonite. The purpose of this report is to describe the modelling work that has been carried out, and the conclusions that have been reached. The experimental programme has carried out a series of long term experiments looking at anaerobic corrosion of carbon steel or cast iron in compacted MX80 bentonite at 30 deg C or 50 deg C. In the bentonite the concentration of iron decreased with increasing distance away from the iron-bentonite interface, with local iron concentrations as high as 20 wt % in

Geochemical investigation of iron transport into bentonite as steel corrodes

Energy Technology Data Exchange (ETDEWEB)

Hunter, Fiona; Bate, Fiona; Heath, Tim; Hoch, Andrew [Serco Assurance, Harwe ll (United Kingdom)

2007-09-15

In Sweden and Finland, it is proposed that spent nuclear fuel will be encapsulated in sealed cylindrical canisters, for disposal in a geologic repository, either in vertical boreholes (KBS-3V) or in long horizontal boreholes (KBS-3H). The canisters will consist of a thick cast iron insert and a copper outer container, and each canister will be surrounded by a compacted bentonite clay buffer. It is important to investigate the possible consequences if a failure of these physical barriers was to occur. For instance, if mechanical failure of the copper outer container were to occur then groundwater could enter the annulus and reach the cast iron insert. This would result in anaerobically corroded iron from the cast iron insert interacting with the bentonite surrounding the canisters. The presence of anaerobically corroded iron in groundwater raises the question of how the bentonite will be affected by this process. In the case of the KBS-3H concept, mechanical failure of the copper outer container could lead to interaction between anaerobically corroded iron and bentonite, as above. However, direct contact between anaerobically corroding carbon steel and bentonite is also likely because of the presence of perforated carbon steel support structures in the long horizontal boreholes. As part of the NF-PRO project, an extensive experimental programme has been carried out over several years to study the interactions between anaerobically corroding carbon steel or cast iron and bentonite. The purpose of this report is to describe the modelling work that has been carried out, and the conclusions that have been reached. The experimental programme has carried out a series of long term experiments looking at anaerobic corrosion of carbon steel or cast iron in compacted MX80 bentonite at 30 deg C or 50 deg C. In the bentonite the concentration of iron decreased with increasing distance away from the iron-bentonite interface, with local iron concentrations as high as 20 wt % in

Response to parenteral iron therapy distinguish unexplained refractory iron deficiency anemia from iron-refractory iron deficiency anemia.

Science.gov (United States)

Akin, M; Sarbay, H; Guler, S; Balci, Y I; Polat, A

2016-04-01

We evaluated that response to parenteral iron therapy could be helpful in distinguishing the types of iron deficiency anemia. This study analyzed responses to IV iron sucrose therapy of 15 children with unexplained refractory iron deficiency anemia (URIDA). We compared the results at diagnosis, 6 weeks and 6 months after the therapy. Results were compared with responses of 11 patients' results with iron-refractory iron deficiency anemia (IRIDA) from our previous study. Six weeks after the start of treatment, ferritin, MCV, MCH and Hb values were in normal range in 10 patients. The increase in Hb, MCH, MCV, and ferritin values ranged 2.6-3.5 g/dL, 1.7-4.2 pg, 2-9 fL, and 13-25 ng/mL, respectively. In five patients, Hb, MCH, and MCV mean (range) values [11.2 g/dL (11-12.2), 24.5 pg (24-25.6), and 67 fL (65-70)] were nearly normal but ferritin mean (range) values [9.8 ng/mL (8-11)] were below normal. Six weeks after the start of treatment, Hb, MCH, MCV and ferritin values of patients with IRIDA were increased. The increase in Hb, MCH, MCV, and ferritin values ranged 0.8-2.7 g/dL, 1.7-4.2 pg, 2-9 fL, and 13-25 ng/mL, respectively. IRIDA is only partially responsive to parenteral iron supplementation. In conclusion, this study demonstrated that the response to intravenous iron therapy for the URIDA cases improved blood parameters more effectively than hereditary IRIDA. Response to parenteral iron therapy would be helpful to distinguish unexplained refractory IDA from hereditary IRIDA for clinicians who do not have access to hepcidin or TMPRS6 mutation analysis. © 2016 John Wiley & Sons Ltd.

Natural radioactivity in iron and steel materials by low-level gamma spectrometry

International Nuclear Information System (INIS)

Tanase, G.; Tanase, Maria

2003-01-01

High resolution low-level gamma spectrometry was applied to perform a radioactivity measurement in iron and steel raw materials (coal, coke, iron ore, pellets, manganese ore, limestone, dolomite), auxiliary materials (scorialite, oxide of Ti, bentonite), and some related final products (cast iron, slag, blast-furnace, flue dust) involved in iron making processing. We control the activity of materials in various kinds of samples and we investigate for transfer of radioactivity during the blast-furnace process. Artificial radioisotopes are rarely encountered. (authors)

Synthesis and Stability of Iron Nanoparticles for Lunar Environment Studies

Science.gov (United States)

Hung, Ching-cheh; McNatt, Jeremiah

2009-01-01

Simulant of lunar dust is needed when researching the lunar environment. However, unlike the true lunar dust, today s simulants do not contain nanophase iron. Two different processes have been developed to fabricate nanophase iron to be used as part of the lunar dust simulant: (1) Sequentially treating a mixture of ferric chloride, fluorinated carbon, and soda lime glass beads at about 300 C in nitrogen, at room temperature in air, and then at 1050 C in nitrogen. The product includes glass beads that are grey in color, can be attracted by a magnet, and contain alpha-iron nanoparticles (which seem to slowly lose their lattice structure in ambient air during a period of 12 months). This product may have some similarity to the lunar glassy regolith that contains Fe(sup 0). (2) Heating a mixture of carbon black and a lunar simulant (a mixed metal oxide that includes iron oxide) at 1050 C in nitrogen. This process simulates lunar dust reaction to the carbon in a micrometeorite at the time of impact. The product contains a chemically modified simulant that can be attracted by a magnet and has a surface layer whose iron concentration increased during the reaction. The iron was found to be alpha-iron and Fe3O4 nanoparticles, which appear to grow after the fabrication process, but stabilizes after 6 months of ambient air storage.

Microwave-assisted combustion synthesis of nano iron oxide/iron-coated activated carbon, anthracite, cellulose fiber, and silica, with arsenic adsorption studies

Science.gov (United States)

Combustion synthesis of iron oxide/iron coated carbons such as activated carbon, anthracite, cellulose fiber and silica is described. The reactions were carried out in alumina crucibles using a Panasonic kitchen microwave with inverter technology, and the reaction process was com...

Investigation of Iron Oxide Morphology in a Cyclic Redox Water Splitting Process for Hydrogen Generation

Directory of Open Access Journals (Sweden)

Michael M. Bobek

2012-10-01

Full Text Available A solar fuels generation research program is focused on hydrogen production by means of reactive metal water splitting in a cyclic iron-based redox process. Iron-based oxides are explored as an intermediary reactive material to dissociate water molecules at significantly reduced thermal energies. With a goal of studying the resulting oxide chemistry and morphology, chemical assistance via CO is used to complete the redox cycle. In order to exploit the unique characteristics of highly reactive materials at the solar reactor scale, a monolithic laboratory scale reactor has been designed to explore the redox cycle at temperatures ranging from 675 to 875 K. Using high resolution scanning electron microscope (SEM and electron dispersive X-ray spectroscopy (EDS, the oxide morphology and the oxide state are quantified, including spatial distributions. These images show the change of the oxide layers directly after oxidation and after reduction. The findings show a significant non-stoichiometric O/Fe gradient in the atomic ratio following oxidation, which is consistent with a previous kinetics model, and a relatively constant, non-stoichiometric O/Fe atomic ratio following reduction.

Kinetic, spectroscopic and chemical modification study of iron release from transferrin; iron(III) complexation to adenosine triphosphate

International Nuclear Information System (INIS)

Thompson, C.P.

1985-01-01

Amino acids other than those that serve as ligands have been found to influence the chemical properties of transferrin iron. The catalytic ability of pyrophosphate to mediate transferrin iron release to a terminal acceptor is largely quenched by modification non-liganded histine groups on the protein. The first order rate constants of iron release for several partially histidine modified protein samples were measured. A statistical method was employed to establish that one non-liganded histidine per metal binding domain was responsible for the reduction in rate constant. These results imply that the iron mediated chelator, pyrophosphate, binds directly to a histidine residue on the protein during the iron release process. EPR spectroscopic results are consistent with this interpretation. Kinetic and amino acid sequence studies of ovotransferrin and lactoferrin, in addition to human serum transferrin, have allowed the tentative assignment of His-207 in the N-terminal domain and His-535 in the C-terminal domain as the groups responsible for the reduction in rate of iron release. The above concepts have been extended to lysine modified transferrin. Complexation of iron(II) to adenosine triphosphate (ATP) was also studied to gain insight into the nature of iron-ATP species present at physiological pH. 31 P NMR spectra are observed when ATP is presented in large excess

Moessbauer study on the formation process of Fe-K composition in iron-based catalyst for dehydrogenation of ethylbenzene

International Nuclear Information System (INIS)

Jiang Keyu; Zhao Zhenjie; Yang Xielong

2001-01-01

Fe-K spinel structure is the predecessor of active phase of potassium promoted iron-based catalyst for dehydrogenation of ethylbenzene. Moessbauer spectroscopy has been used to study the formation process of Fe-K spinel structure which depends on the catalyst composition and preparing condition. The results may prove useful for production of industrial catalyst

Iron and manganese oxide mineralization in the Pacific

Science.gov (United States)

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

1997-01-01

Iron, manganese, and iron-manganese deposits occur in nearly all geomorphologic and tectonic environments in the ocean basins and form by one or more of four processes: (1) hydrogenetic precipitation from cold ambient seawater, (2) precipitation from hydrothermal fluids, (3) precipitation from sediment pore waters that have been modified from bottom water compositions by diagenetic reactions in the sediment column and (4) replacement of rocks and sediment. These processes are discussed.

Iron isomaltoside 1000: a new intravenous iron for treating iron deficiency in chronic kidney disease

DEFF Research Database (Denmark)

Wikström, Björn; Bhandari, Sunil; Barany, Peter

2011-01-01

Patients with chronic kidney disease (CKD) often suffer from iron deficiency anemia necessitating treatment with intravenous iron. This study was designed to assess the safety of iron isomaltoside 1000 (Monofer) in CKD patients. The secondary objective was to assess its effect on iron deficiency...... anemia....

Friction welding of ductile cast iron using interlayers

International Nuclear Information System (INIS)

Winiczenko, Radoslaw; Kaczorowski, Mieczyslaw

2012-01-01

Highlights: → The results of the study of the friction welding of ductile cast iron using interlayers are presented. → The results of the analysis shows that the joint has the tensile strength compared to that of basic material. → In case of ductile cast iron, it is possible to reach the tensile strength equals even 700 MPa. → The process of friction welding was accompanied with diffusion of Cr, Ni and C atoms across the interface. -- Abstract: In this paper, ductile cast iron-austenitic stainless steel, ductile cast iron-pure Armco iron and ductile cast iron-low carbon steel interlayers were welded, using the friction welding method. The tensile strength of the joints was determined, using a conventional tensile test machine. Moreover, the hardness across the interface of materials was measured on metallographic specimens. The fracture surface and microstructure of the joints was examined using either light stereoscope microscopy as well as electron microscopy. In this case, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were applied. The results of the analysis shows that the joint has the tensile strength compared to that of basic material. In case of ductile cast iron, it is possible to reach the tensile strength equals even 700 MPa. It was concluded that the process of friction welding was accompanied with diffusion of Cr, Ni and C atoms across the ductile cast iron-stainless steel interface. This leads to increase in carbon concentration in stainless steel where chromium carbides were formed, the size and distribution of which was dependent on the distance from the interface.

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

Directory of Open Access Journals (Sweden)

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.

Iron oxides in human spleen.

Science.gov (United States)

Kopáni, Martin; Miglierini, Marcel; Lančok, Adriana; Dekan, Július; Čaplovicová, Mária; Jakubovský, Ján; Boča, Roman; Mrazova, Hedviga

2015-10-01

Iron is an essential element for fundamental cell functions and a catalyst for chemical reactions. Three samples extracted from the human spleen were investigated by scanning (SEM) and transmission electron microscopy (TEM), Mössbauer spectrometry (MS), and SQUID magnetometry. The sample with diagnosis of hemosiderosis (H) differs from that referring to hereditary spherocytosis and the reference sample. SEM reveals iron-rich micrometer-sized aggregate of various structures-tiny fibrils in hereditary spherocytosis sample and no fibrils in hemochromatosis. Hematite and magnetite particles from 2 to 6 μm in TEM with diffraction in all samples were shown. The SQUID magnetometry shows different amount of diamagnetic, paramagnetic and ferrimagnetic structures in the tissues. The MS results indicate contribution of ferromagnetically split sextets for all investigated samples. Their occurrence indicates that at least part of the sample is magnetically ordered below the critical temperature. The iron accumulation process is different in hereditary spherocytosis and hemosiderosis. This fact may be the reason of different iron crystallization.

Iron removal on feldspar by using Averrhoa bilimbii as bioleaching agent

Science.gov (United States)

Amin, Muhammad; Aji, Bramantyo B.; Supriyatna, Yayat Iman; Bahfie, Fathan

2017-01-01

Investigation of Averrhoa bilimbii as bioleaching agent was carried out. Parameters of leaching duration, acid concentration, and temperature were performed in iron removal process. Feldspar with sized 149 µm was diluted in 30 ml acid solution in order to reduce its iron content. The experimental results showed a good technical feasibility of the process which iron oxide content of feldspar was decreased from 2.24% to 0.29%. The lowest iron concentration remained was obtained after 5 hours of leaching treatment at 60 °C, and concentrated (100 vol%) Averrhoa bilimbii extract as bioleaching agent. SEM characterizations were carried out on the feldspar before and after the leaching treatment. The result shows that there were no significant effect of leaching process on the ore morphology.

Iron biomineralization by anaerobic neutrophilic iron-oxidizing bacteria

DEFF Research Database (Denmark)

Miot, Jennyfer; Benzerara, Karim; Morin, Guillaume

2009-01-01

Minerals formed by bio-oxidation of ferrous iron (Fe(II)) at neutral pH, their association with bacterial ultrastructures as well as their impact on the metabolism of iron-oxidizing bacteria remain poorly understood. Here, we investigated iron biomineralization by the anaerobic nitrate-dependent ......Minerals formed by bio-oxidation of ferrous iron (Fe(II)) at neutral pH, their association with bacterial ultrastructures as well as their impact on the metabolism of iron-oxidizing bacteria remain poorly understood. Here, we investigated iron biomineralization by the anaerobic nitrate...... precipitation in the periplasm (in a few tens of minutes), followed by the formation of surface-bound globules. Moreover, we frequently observed an asymmetric mineral thickening at the cell poles. In parallel, the evolution of iron oxidation was quantified by STXM: iron both contained in the bacteria...... and in the extracellular precipitates reached complete oxidation within 6 days. While a progressive oxidation of Fe in the bacteria and in the medium could be observed, spatial redox (oxido-reduction state) heterogeneities were detected at the cell poles and in the extracellular precipitates after 1 day. All...

Repair welding of cast iron coated electrodes

Science.gov (United States)

Żuk, M.; Górka, J.; Dojka, R.; Czupryński, A.

2017-08-01

Welding cast iron is a complex production procedure. Repair welding was used to repair damaged or poorly made castings. This is due to a tendency to cracking of the material during welding as well as after it. Welding cast iron can be carried out on hot or on cold. Hot welding requires high heat material and the use of welding material in the form of cast iron. In the case of cold welding, it is possible to use different materials. Mostly used filler metals are nickel and copper based. The work shows the course of research concerning repairmen of ductile iron with arc welding method. For the reparation process four types of ESAB company coated electrodes dedicated for cast iron were used with diameter 3.2 and 4 mm: ES 18-8-6B (4mm), EB 150 (4mm), OK NiCl, EŻM. In the cast iron examined during the testing grooves were made using plasma methods, in order to simulate the removed casting flaws. Then the welding process with coated electrodes was executed. The process utilized low welding current row of 100A, so there would only be a small amount of heat delivered to the heat affected zone (HAZ). Short stitches were made, after welding it was hammered, in order to remove stresses. After the repair welding the part of studies commenced which purpose was finding surface defects using visual testing (VT) and penetration testing (PT). In the second part, a series of macro and microscopic studies were executed witch the purpose of disclosuring the structure. Then the hardness tests for welds cross sections were performed. An important aspect of welding cast iron is the colour of the padding weld after welding, more precisely the difference between the base material and padding weld, the use of different materials extra gives the extra ability to select the best variant. The research of four types of coated electrode was executed, based on the demands the best option in terms of aesthetic, strength and hardness.

46 CFR 56.60-10 - Cast iron and malleable iron.

Science.gov (United States)

2010-10-01

... 46 Shipping 2 2010-10-01 2010-10-01 false Cast iron and malleable iron. 56.60-10 Section 56.60-10... APPURTENANCES Materials § 56.60-10 Cast iron and malleable iron. (a) The low ductility of cast iron and malleable iron should be recognized and the use of these metals where shock loading may occur should be...

The existence of native iron - implications for nuclear waste management. Part 1

International Nuclear Information System (INIS)

Hellmuth, K.H.

1991-05-01

Occurance of native iron in near-surface environments on the earth is a remarkable pehomenon, which has implications on issues of nuclear waste management, above all, long-term corrosion, matrix diffusion and water-rock interaction. Exisisting knowledge on native iron is reviewed, laying stress on processes and parameters, which led to preservation of the iron during geological periods of time. Types of occurrence, composition and properties of the iron, and mineral parageneses associated are described. Processes affecting the iron during the course of its evolution, passing through the stages of the melt, differentiation, crystallization, cooling, fracturing, hydrothermal fluid intrusion and low temperature weathering are discussed

Molecular dynamics study of dynamic and structural properties of supercooled liquid and glassy iron in the rapid-cooling processes

Energy Technology Data Exchange (ETDEWEB)

Cao, Qi-Long; Huang, Duo-Hui; Yang, Jun-Sheng; Wan, Min-Jie; Wang, Fan-Hou, E-mail: eatonch@gmail.com

2014-10-01

Molecular dynamics simulations were applied to study the dynamic and structural properties of supercooled liquid and glassy iron in the rapid-cooling processes. The mean-square displacement and the non-Gaussian parameter were used to describe the dynamic properties. The evolution of structural properties was investigated using the pair distribution functions and bond-angle distribution functions. Results for dynamic and structural relaxations indicate that the dynamic features are consistently correlated with the structure evolution, and there are three temperature regions as the temperature decreases: (1) at higher temperatures (1500 K, 1300 K, and 1100 K), the system remains in the liquid characteristics during the overall relaxation process. (2) At medial temperatures (1050 K, 900 K, and 700 K), a fast β-relaxation is followed by a much slower α-relaxation. There is a little change in the structural properties in the β-relaxation region, while major configuration rearrangements occurred in the α-relaxation range and the crystallization process was completed at the end of α-relaxation region. (3) At lower temperature (500 K), the system shows glassy characteristics during the overall relaxation process. In addition, the melting temperature, glass transition temperature and diffusion coefficients of supercooled liquid iron are also computed.

Digging for red nuggets: discovery of hot halos surrounding massive, compact, relic galaxies

Science.gov (United States)

Werner, N.; Lakhchaura, K.; Canning, R. E. A.; Gaspari, M.; Simionescu, A.

2018-04-01

We present the results of Chandra X-ray observations of the isolated, massive, compact, relic galaxies MRK 1216 and PGC 032873. Compact massive galaxies observed at z > 2, also called red nuggets, formed in quick dissipative events and later grew by dry mergers into the local giant ellipticals. Due to the stochastic nature of mergers, a few of the primordial massive galaxies avoided the mergers and remained untouched over cosmic time. We find that the hot atmosphere surrounding MRK 1216 extends far beyond the stellar population and has an 0.5-7 keV X-ray luminosity of LX = (7.0 ± 0.2) × 1041 erg s-1, which is similar to the nearby X-ray bright giant ellipticals. The hot gas has a short central cooling time of ˜50 Myr and the galaxy has a ˜13 Gyr old stellar population. The presence of an X-ray atmosphere with a short nominal cooling time and the lack of young stars indicate the presence of a sustained heating source, which prevented star formation since the dissipative origin of the galaxy 13 Gyrs ago. The central temperature peak and the presence of radio emission in the core of the galaxy indicate that the heating source is radio-mechanical AGN feedback. Given that both MRK 1216 and PGC 032873 appear to have evolved in isolation, the order of magnitude difference in their current X-ray luminosity could be traced back to a difference in the ferocity of the AGN outbursts in these systems. Finally, we discuss the potential connection between the presence of hot halos around such massive galaxies and the growth of super/over-massive black holes via chaotic cold accretion.

Magnetic property effect on transport processes in resistance spot welding

Energy Technology Data Exchange (ETDEWEB)

Wei, P S [Department of Mechanical and Electro-Mechanical Engineering, National Sun Yat-Sen University, Kaohsiung, Taiwan 80424 (China); Wu, T H, E-mail: pswei@mail.nsysu.edu.tw, E-mail: wux0064@gmail.com [Department of Mechanical Engineering, Yung Ta Institute of Technology and Commerce, Pintong, Taiwan 909 (China)

2011-08-17

This study investigates the effects of the Curie temperature and magnetic permeability on transport variables, solute distribution and nugget shapes during resistance spot welding. The Curie temperature is the temperature below which a metal or alloy is ferromagnetic with a high magnetic permeability, and above which it is paramagnetic with a small magnetic permeability. The model proposed here accounts for electromagnetic force, heat generation and contact resistance at the faying surface and electrode-workpiece interfaces and bulk resistance in workpieces. Contact resistance includes constriction and film resistances, which are functions of hardness, temperature, electrode force and surface condition. The computed results show that transport variables and nugget shapes can be consistently interpreted from the delay of response time and jump of electric current density as a result of finite magnetic diffusion, rather than through the examination of the variations of dynamic electrical resistance with time. The molten nugget on the faying surface is initiated earlier with increasing magnetic permeability and Curie temperature. A high Curie temperature enhances convection and solute mixing, and readily melts through the workpiece surface near the electrode edge. Any means to reduce the Curie temperature or magnetic permeability, such as adjusting the solute content, can be a good way to control weld quality. This study can also be applied to interpret the contact problems encountered in various electronics and packaging technologies, and so on.

Mathematical model of the reformer sponge iron cycle

International Nuclear Information System (INIS)

Fraser, S.; Hacker, V.; Evers, B.; Hierzer, J.; Besenhard, J.O.

2003-01-01

A mathematical model of the Reformer Sponge Iron Cycle (RESC), an innovative hydrogen production process based on redox reactions of iron ore pellets is presented. In the oxidation stage of the RESC, hydrogen is produced by blowing steam over hot iron pellets, hence oxidizing the iron. In the reduction stage, synthesis gas coming from a reformer mixed with a fraction of recycled off-gas is used to reduce the iron oxide pellets (wuestite and/or magnetite) back into iron again. A mathematical model of the complete RESC was developed and verified with experimental data. The model is based on calculations of the equilibrium gas concentrations for reformer and Sponge Iron Reactor (SIR). The current model computes mass fluxes, molar fluxes, partial pressures and variations of the respective throughout the complete cycle. The recycle rate, determining the fraction of SIR off-gas recycled and added to the input gas stream was subsequently optimized in order to maximize the amount of iron oxide reduced for a certain input gas flow. (author)

Iron-borosilicate soft magnetic composites: The correlation between processing parameters and magnetic properties for high frequency applications

Energy Technology Data Exchange (ETDEWEB)

Gheiratmand, T., E-mail: t.gheiratmand@yahoo.com; Madaah Hosseini, H.R., E-mail: Madaah@sharif.edu; Seyed Reihani, S.M.

2017-05-01

Iron-borosilicate soft magnetic composites are suitable magnetic materials for high temperature and high frequency applications. In this research two different techniques have been applied to fabricate these composites: uniaxial pressing following by sintering and spark plasma sintering. Different processing parameters including the content of borosilicate, the amount of compaction pressure and the size of iron particles have been evaluated through the study of microstructure and magnetic properties. The microstructural observations showed that the borosilicate is distributed on the iron grain boundaries enhancing the resistivity and causing the loss of eddy currents. Increasing the compaction pressure was led to the decrease of electrical resistivity. By increasing the frequency both real and imaginary parts of permeability decreased. The use of higher content of borosilicate resulted in the lower decreasing slop of permeability. Best combination of density, permeability and electrical resistivity was obtained in the sample with 2 wt% of borosilicate. In addition, the densification of powders with fine particles was more difficult than coarse particles due to the inter particles friction and bridging effects. Furthermore, as the particles size increases the size of open porosities before sintering where the borosilicate could aggregate enhances. This could yields to the increase in the electrical resistivity. The high ratio of surface to the volume in the powders with fine particles results in the developing the demagnetizing fields and subsequently, decreasing the permeability. The highest relative density (99.99% of theoretical density) with best distribution of borosilicate was achieved in the composites produced by spark plasma sintering (SPS). The relaxation frequency, obtained from imaginary part of permeability, was found as 340 Hz in the composites made by SPS. - Highlights: • Iron-borosilicate SMC was produced for high temperature and frequency

Effect of Organic Substances on the Efficiency of Fe(Ii to Fe(Iii Oxidation and Removal of Iron Compounds from Groundwater in the Sedimentation Process

Directory of Open Access Journals (Sweden)

Krupińska Izabela

2017-09-01

Full Text Available One of the problems with iron removal from groundwater is organic matter. The article presents the experiments involved groundwater samples with a high concentration of total iron - amounting to 7.20 mgFe/dm3 and an increased amount of organic substances (TOC from 5.50 to 7.50 mgC/dm3. The water samples examined differed in terms of the value of the ratio of the TOC concentration and the concentration of total iron (D. It was concluded that with increase in the coexistence ratio of organic substances and total iron in water (D = [TOC]/[Fetot], efficiency of Fe(II to Fe(III oxidization with dissolved oxygen decreased, while the oxidation time was increasing. This rule was not demonstrated for potassium manganate (VII when used as an oxidizing agent. The application of potassium manganate (VII for oxidation of Fe(II ions produced the better results in terms of total iron concentration reduction in the sedimentation process than the oxidation with dissolved oxygen.

Effect of Organic Substances on the Efficiency of Fe(Ii) to Fe(Iii) Oxidation and Removal of Iron Compounds from Groundwater in the Sedimentation Process

Science.gov (United States)

Krupińska, Izabela

2017-09-01

One of the problems with iron removal from groundwater is organic matter. The article presents the experiments involved groundwater samples with a high concentration of total iron - amounting to 7.20 mgFe/dm3 and an increased amount of organic substances (TOC from 5.50 to 7.50 mgC/dm3). The water samples examined differed in terms of the value of the ratio of the TOC concentration and the concentration of total iron (D). It was concluded that with increase in the coexistence ratio of organic substances and total iron in water (D = [TOC]/[Fetot]), efficiency of Fe(II) to Fe(III) oxidization with dissolved oxygen decreased, while the oxidation time was increasing. This rule was not demonstrated for potassium manganate (VII) when used as an oxidizing agent. The application of potassium manganate (VII) for oxidation of Fe(II) ions produced the better results in terms of total iron concentration reduction in the sedimentation process than the oxidation with dissolved oxygen.

Quantification of body iron and iron absorption in the REDS-II Donor Iron Status Evaluation (RISE) study.

Science.gov (United States)

Kiss, Joseph E; Birch, Rebecca J; Steele, Whitney R; Wright, David J; Cable, Ritchard G

2017-07-01

Repeated blood donation alters the iron balance of blood donors. We quantified these effects by analyzing changes in body iron as well as calculating iron absorbed per day for donors enrolled in a prospective study. For 1308 donors who completed a final study visit, we calculated total body iron at the enrollment and final visits and the change in total body iron over the course of the study. Taking into account iron lost from blood donations during the study and obligate losses, we also calculated the average amount of iron absorbed per day. First-time/reactivated donors at enrollment had iron stores comparable to previous general population estimates. Repeat donors had greater donation intensity and greater mean iron losses than first-time/reactivated donors, yet they had little change in total body iron over the study period, whereas first-time/reactivated donors had an average 35% drop. There was higher estimated iron absorption in the repeat donors (men: 4.49 mg/day [95% confidence interval [CI], 4.41-4.58 mg/day]; women: 3.75 mg/day [95% CI, 3.67-3.84 mg/day]) compared with estimated iron absorption in first-time/reactivated donors (men: 2.89 mg/day [95% CI, 2.75-3.04 mg/day]; women: 2.76 mg/day [95% CI, 2.64-2.87 mg/day]). The threshold for negative estimated iron stores (below "0" mg/kg stores) was correlated with the development of anemia at a plasma ferritin value of 10 ng/mL. These analyses provide quantitative data on changes in estimated total body iron for a broad spectrum of blood donors. In contrast to using ferritin alone, this model allows assessment of the iron content of red blood cells and the degree of both iron surplus and depletion over time. © 2017 AABB.

Iron-Deficiency Anemia

Medline Plus

Full Text Available ... Research Home / < Back To Health Topics / Iron-Deficiency Anemia Iron-Deficiency Anemia Also known as Leer en español Iron-deficiency ... iron-deficiency anemia. Blood tests to screen for iron-deficiency anemia To screen for iron-deficiency anemia, your doctor ...

Iron oxides characterization by Moessbauer spectroscopy

International Nuclear Information System (INIS)

Basurto Sanchez, R.

1993-01-01

In this work rust development on low carbon wire surface after the conformation process at different temperatures was studied by Moessbauer spectroscopy. The characterization was made by determining the following spectral parameters; 1) Quadrupole splitting, 2) Isomer shift, and 3) Magnetic splitting. The area quantification determined the percentage amount of three different iron oxides. These iron oxides were: a) Wustite (Fe O), b) Hematite (Fe 2 O 3 ), and c) Magnetite (Fe 3 O 4 ) which were present in the rust studied. With the results it was possible to establish the best temperature to favor the development of each of these iron oxides. (Author)

Impact of sorghum processing on phytate, phenolic compounds and in vitro solubility of iron and zinc in thick porridges

NARCIS (Netherlands)

Kayodé, A.P.P.; Linnemann, A.R.; Nout, M.J.R.; Boekel, van M.A.J.S.

2007-01-01

This study focussed on the impact of process variables on levels of phytate and phenolic compounds, and in vitro solubility of iron (Fe) and zinc (Zn) in sorghum porridges, a major staple in semi-arid tropics. The aim was to identify practices that enhance the mineral availability in this type of

Redox process catalysed by growing crystal-strengite, FePO4,2H2O, crystallizing from solution with iron(II) and hydroxylamine

Science.gov (United States)

Lundager Madsen, Hans Erik

2014-09-01

In an attempt to grow pure crystals of the iron(II) phosphate vivianite, Fe3(PO4)2,8H2O, from a solution of Mohr's salt, Fe(NH4)2(SO4)2,6H2O, added to a solution of ammonium phosphate, hydroxylammonium chloride, NH3OHCl, was added to the iron(II) stock solution to eliminate oxidation of iron(II) by oxygen from the air. However, the effect turned out to be the opposite of the expected: whereas hydroxylamine reduces iron(III) in bulk solution, it acted as a strong oxidant in the presence of growing iron phosphate crystals, causing the crystallization of the iron(III) phosphate strengite, FePO4,2H2O, as the only solid phase. Evidently the crystal surface catalyses oxidation of iron(II) by hydroxylamine. The usual composite kinetics of spiral growth and surface nucleation was found. The surface-nucleation part yielded edge free energy λ in the range 12-45 pJ/m, virtually independent of temperature and in the range typical for phosphates of divalent metals. The scatter of values for λ presumably arises from contributions from different crystal forms to the overall growth rate. The low mean value points to strong adsorption of iron(II), which is subsequently oxidized at the crystal surface, forming strengite. The state of the system did not tend to thermodynamic equilibrium, but to a metastable state, presumably controlled by the iron(II) rich surface layer of the crystal. In addition to crystal growth, it was possible to measure nucleation kinetics by light scattering (turbidimetry). A point of transition from heterogeneous to homogeneous nucleation was found, and from the results for the homogeneous domain a rather precise value of crystal surface free energy γ=55 mJ/m2 was found. This is a relatively low value as well, indicating that the redox process plays a role already at the nucleation stage.

49 CFR 192.373 - Service lines: Cast iron and ductile iron.

Science.gov (United States)

2010-10-01

... 49 Transportation 3 2010-10-01 2010-10-01 false Service lines: Cast iron and ductile iron. 192.373... Regulators, and Service Lines § 192.373 Service lines: Cast iron and ductile iron. (a) Cast or ductile iron... cast iron pipe or ductile iron pipe is installed for use as a service line, the part of the service...

Melting of Grey Cast Iron Based on Steel Scrap Using Silicon Carbide

Directory of Open Access Journals (Sweden)

Stojczew A.

2014-08-01

Full Text Available The paper presents the issue of synthetic cast iron production in the electric induction furnace exclusively on the steel scrap base. Silicon carbide and synthetic graphite were used as carburizers. The carburizers were introduced with solid charge or added on the liquid metal surface. The chemical analysis of the produced cast iron, the carburization efficiency and microstructure features were presented in the paper. It was stated that ferrosilicon can be replaced by silicon carbide during the synthetic cast iron melting process. However, due to its chemical composition (30% C and 70% Si which causes significant silicon content in iron increase, the carbon deficit can be partly compensated by the carburizer introduction. Moreover it was shown that the best carbon and silicon assimilation rate is obtained where the silicon carbide is being introduced together with solid charge. When it is thrown onto liquid alloy surface the efficiency of the process is almost two times less and the melting process lasts dozen minutes long. The microstructure of the cast iron produced with the silicon carbide shows more bulky graphite flakes than inside the microstructure of cast iron produced on the pig iron base.

Iron modified bentonite: Enhanced adsorption performance for organic pollutant and its regeneration by heterogeneous visible light photo-Fenton process at circumneutral pH

Energy Technology Data Exchange (ETDEWEB)

Gao, Yaowen; Guo, Yongzhao; Zhang, Hui, E-mail: eeng@whu.edu.cn

2016-01-25

Highlights: • The iron modification markedly improved the adsorption performance of FeMB for RhB. • LED lamps emitting white light were employed as visible light source. • FeMB can be regenerated by visible light photo-Fenton process at circumneutral pH. • FeMB can be reused repeatedly after the heterogeneous photo-Fenton regeneration. - Abstract: Iron modified bentonite (FeMB) was prepared and used as an inexpensive adsorbent to rapidly remove organic pollutant (Rhodamine B, RhB) from aqueous solution. The iron modification significantly improved the adsorption performance of FeMB for RhB and permitted an easy separation of FeMB from the treated effluent. The equilibrium adsorption studies indicated that the dye molecules obeyed Langmuir type of adsorption with the calculated maximum adsorption capacity of 168.13 mg g{sup −1} for FeMB. The heterogeneous photo-Fenton process operated at circumneutral pH in the presence of visible light irradiation was found to be effective for the regeneration of the spent FeMB. Furthermore, the regeneration efficiency of as high as 79% was still achieved after 5 consecutive adsorption-regeneration cycles. Considering that, the visible light photo-Fenton approach could be applied as an excellent alternative for regenerating clay-based adsorbents by avoiding the use of dissolved iron salts.

The structure of high-quality aluminium cast iron

Directory of Open Access Journals (Sweden)

D. Kopyciński

2012-01-01

Full Text Available In this study presents the analyse of aluminium iron cast structure (as-cast condition which are used in high temperature. While producing the casts of aluminium iron major influence has been preserve the structure of technological process parameters. The addition to Fe-C-Al alloy V, Ti, Cr leads to the improvement of functional and mechanical cast qualities. In this study, a method was investigated to eliminate the presence of undesirable Al4C3 phases in a aluminium cast iron structure and thus improve the production process. V and Ti additions in aluminium cast iron allows to development of FeAl - VC or TiC alloys. In particular, V or Ti contents above 5 wt.% were found to totally eliminate the presence of Al4C3. In addition, preliminary work indicates that the alloy with the FeAl - VC or TiC structure reveals high oxidation resistance. The introduction of 5 wt.% chromium to aluminium cast iron strengthened Al4C3 precipitate. Thus, the resultant alloy can be considered an intermetallic FeAl matrix strengthened by VC and TiC or modified Al4C3 reinforcements.

Comparative study of efficacy, tolerability and compliance of oral iron preparations (iron edetate, iron polymatose complex) and intramuscular iron sorbitol in iron deficiency anaemia in children

International Nuclear Information System (INIS)

Afzal, M.; Qureshi, S.M.; Lutafullah, M.

2009-01-01

To compare the efficacy, tolerability and compliance of oral iron preparations(iron edetate and Iron polymaltose complex) with each other and with intramuscular iron sorbitol in iron deficiency anaemia in children. A Randomized Controlled Trial (RCT) was carried out at the Paediatric Department of Combined Military Hospital (CMH) from January 2006 to December 2007. In total 146 children, up to 12 years age having haemoglobin (Hb%) less than 8 gm% were included. They were randomly distributed into three groups. Group A(64 cases) received oral sodium iron edetate (SIE), Group B (40 cases) received oral iron polymaltose complex (IPC) and group C (42 cases) received intramuscular iron sorbitol (IS) in recommended dosages. Rise in Hb%>10 gm% was kept as desired target. Maximum duration of treatment planned was 2 weeks for parenteral iron (group C) and 12 weeks for oral iron (groups A and B). Haematological parameters- Hb%, mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC) were measured at induction followed at 2 weeks, 4 weeks, 8 weeks and 12 weeks after start of treatment. Compliance and drop out rates were determined on each visit. Data was analyzed using SPSS version 10. ANOVA was used to analyze difference in rise in Hb% at various intervals. Statistically significant increase in mean Hb%, MCV, MCHC after 02 weeks was observed in group C (IS). Rise in these parameters became significant in group A (SIE) and B (IPC) after 04 weeks. Persistent rise was observed in oral groups at 08 and 12 weeks. Rise in Hb% was much faster in group C (IS). It took 2 weeks to achieve mean Hb% > 10 gm% and compliance rate was 40.5%, while to achieve same target, duration required was 8 weeks in group A (SIE) and 12 weeks in group B (IPC) and compliance rate was 39% and 30% respectively. Adverse effects were much more common with group A (SIE) as compared to other two groups. Intramuscular iron sorbitol is a reliable and

In-depth study of the mechanical properties for Fe_3Al based iron aluminide fabricated using the wire-arc additive manufacturing process

International Nuclear Information System (INIS)

Shen, Chen; Pan, Zengxi; Cuiuri, Dominic; Dong, Bosheng; Li, Huijun

2016-01-01

An innovative wire-arc additive manufacturing (WAAM) process is used to fabricate iron aluminide alloy in-situ, through separate feeding of pure Fe and Al wires into a molten pool that is generated by the gas tungsten arc welding (GTAW) process. This paper investigates the morphologies, chemical compositions and mechanical properties of the as-fabricated 30 at% Al iron aluminide wall components, and how these properties vary at different locations within the buildup wall. The tensile properties are also measured in different loading orientations; as epitaxial growth of large columnar grains is observed in the microstructures. Fe_3Al is the only phase detected in the middle buildup section of the wall structure, which constitutes the majority of the deposited material. The bottom section of the structure contains a dilution affected region where some acicular Fe_3AlC_0_._5 precipitates can be observed, induced by carbon from the steel substrate that was used for fabrication. The microhardness and chemical composition indicate relatively homogeneous material properties throughout the buildup wall. However, the tensile properties are very different in the longitudinal direction and normal directions, due to epitaxial growth of large columnar grains. In general, the results have demonstrated that the WAAM process is capable of producing full density in-situ-alloyed iron aluminide components with tensile properties that are comparable to powder metallurgy methods.

Ceruloplasmin-ferroportin system of iron traffic in vertebrates

Institute of Scientific and Technical Information of China (English)

Giovanni; Musci; Fabio; Polticelli; Maria; Carmela; Bonaccorsi; di; Patti

2014-01-01

Safe trafficking of iron across the cell membrane is a delicate process that requires specific protein carriers. While many proteins involved in iron uptake by cells are known, only one cellular iron export protein has been identified in mammals: ferroportin(SLC40A1). Ceruloplasmin is a multicopper enzyme endowed with ferroxidase activity that is found as a soluble isoform in plasma or as a membrane-associated isoform in specific cell types. According to the currently accepted view, ferrous iron transported out of the cell by ferroportin would be safely oxidized by ceruloplasmin to facilitate loading on transferrin. Therefore, the ceruloplasminferroportin system represents the main pathway for cellular iron egress and it is responsible for physiological regulation of cellular iron levels. The most recent findings regarding the structural and functional features of ceruloplasmin and ferroportin and their relationship will be described in this review.

Application of magnetic iron oxide nanoparticles in stabilization process of biological molecules

Directory of Open Access Journals (Sweden)

Mohammad Hossien Salmani

2017-07-01

Conclusion: Co-precipitation method is an easy way to prepare magnetic nanoparticles of iron with a large surface and small particle size, which increases the ability of these particles to act as a suitable carrier for enzyme stabilization. Adequate modification of the surface of these nanoparticles enhances their ability to bind to biological molecules. The immobilized protein or enzyme on magnetic nanoparticles are more stable against structural changes, temperature and pH in comparison with un-stabilized structures, and it is widely used in various sciences, including protein isolation and purification, pharmaceutical science, and food analysis. Stabilization based on the covalent bonds and physical absorption is nonspecific, which greatly limits their functionality. The process of stabilization through bio-mediums provide a new method to overcome the selectivity problem.

Results of the First American Prospective Study of Intravenous Iron in Oral Iron-Intolerant Iron-Deficient Gravidas.

Science.gov (United States)

Auerbach, Michael; James, Stephanie E; Nicoletti, Melissa; Lenowitz, Steven; London, Nicola; Bahrain, Huzefa F; Derman, Richard; Smith, Samuel

2017-12-01

Anemia affects up to 42% of gravidas. Neonatal iron deficiency is associated with low birth weight, delayed growth and development, and increased cognitive and behavioral abnormalities. While oral iron is convenient, up to 70% report significant gastrointestinal toxicity. Intravenous iron formulations allowing replacement in one visit with favorable side-effect profiles decrease rates of anemia with improved hemoglobin responses and maternal fetal outcomes. Seventy-four oral iron-intolerant, second- and third-trimester iron-deficient gravidas were questioned for oral iron intolerance and treated with intravenous iron. All received 1000 mg of low-molecular-weight iron dextran in 250 mL normal saline. Fifteen minutes after a test dose, the remainder was infused over the balance of 1 hour. Subjects were called at 1, 2, and 7 days to assess delayed reactions. Four weeks postinfusion or postpartum, hemoglobin levels and iron parameters were measured. Paired t test was used for hemoglobin and iron; 58/73 women were questioned about interval growth and development of their babies. Seventy-three of 74 enrolled subjects completed treatment. Sixty had paired pre- and posttreatment data. The mean pre- and posthemoglobin concentrations were 9.7 and 10.8 g/dL (P iron deficiency anemia. Intravenous iron has less toxicity and is more effective, supporting moving it closer to frontline therapy. Copyright © 2017 Elsevier Inc. All rights reserved.

Studying Irony Detection Beyond Ironic Criticism: Let's Include Ironic Praise

Directory of Open Access Journals (Sweden)

Richard Bruntsch

2017-04-01

Full Text Available Studies of irony detection have commonly used ironic criticisms (i.e., mock positive evaluation of negative circumstances as stimulus materials. Another basic type of verbal irony, ironic praise (i.e., mock negative evaluation of positive circumstances is largely absent from studies on individuals' aptitude to detect verbal irony. However, it can be argued that ironic praise needs to be considered in order to investigate the detection of irony in the variety of its facets. To explore whether the detection ironic praise has a benefit beyond ironic criticism, three studies were conducted. In Study 1, an instrument (Test of Verbal Irony Detection Aptitude; TOVIDA was constructed and its factorial structure was tested using N = 311 subjects. The TOVIDA contains 26 scenario-based items and contains two scales for the detection of ironic criticism vs. ironic praise. To validate the measurement method, the two scales of the TOVIDA were experimentally evaluated with N = 154 subjects in Study 2. In Study 3, N = 183 subjects were tested to explore personality and ability correlates of the two TOVIDA scales. Results indicate that the co-variance between the ironic TOVIDA items was organized by two inter-correlated but distinct factors: one representing ironic praise detection aptitude and one representing ironic criticism detection aptitude. Experimental validation showed that the TOVIDA items truly contain irony and that item scores reflect irony detection. Trait bad mood and benevolent humor (as a facet of the sense of humor were found as joint correlates for both ironic criticism and ironic praise detection scores. In contrast, intelligence, trait cheerfulness, and corrective humor were found as unique correlates of ironic praise detection scores, even when statistically controlling for the aptitude to detect ironic criticism. Our results indicate that the aptitude to detect ironic praise can be seen as distinct from the aptitude to detect ironic

Absorption of medicamental iron and iron from food

International Nuclear Information System (INIS)

Reizenstein, P.; Carlmark, B.; Ehn, L.; Forsberg, K.; Hoeglund, S.; Terpstra, T.

1976-01-01

Methods are reviewed for the measurement of iron absorption. The chemical balance method has been almost entirely supplanted by radioisotope methods, which include notably whole-body counting and measurement of incorporation of radioiron into red cells. A survey is also given of the various conditions that influence iron absorption, including chemical form of iron, amount of iron, accompanying diet. Absorption tests must be conducted under relevant conditions. (author)

Iron aluminide composites

International Nuclear Information System (INIS)

Schneibel, J.H.

1999-01-01

Iron aluminides with the B2 structure are highly oxidation and corrosion resistant. They are thermodynamically compatible with a wide range of ceramics such as TiC, WC, TiB 2 , and ZrB 2 . In addition, liquid iron aluminides wet these ceramics very well. Therefore, FeAl/ceramic composites may be produced by techniques such as liquid phase sintering of powder mixtures, or pressureless melt infiltration of ceramic powders with liquid FeAl. These techniques, the resulting microstructures, and their advantages as well as limitations are described. Iron aluminide composites can be very strong. Room temperature flexure strengths as high as 1.8 GPa have been observed for FeAl/WC. Substantial gains in strength of elevated temperatures (1,073 K) have also been demonstrated. Above 40 vol.% WC the room temperature flexure strength becomes flaw-limited. This is thought to be due to processing flaws and limited interfacial strength. The fracture toughness of FeAl/WC is unexpectedly high and follows a rule of mixtures. Interestingly, sufficiently thin (<1 microm) FeAl ligaments between adjacent WC particles fracture not by cleavage, but in a ductile manner. For these thin ligaments the dislocation pile-ups formed during deformation are not long enough to nucleate cleavage fracture, and their fracture mode is therefore ductile. For several reasons, this brittle-to-ductile size transition does not improve the fracture toughness of the composites significantly. However, since no cleavage cracks are nucleated in sufficiently thin FeAl ligaments, slow crack growth due to ambient water vapor does not occur. Therefore, as compared to monolithic iron aluminides, environmental embrittlement is dramatically reduced in iron aluminide composites

Remote-sensing data processing with the multivariate regression analysis method for iron mineral resource potential mapping: a case study in the Sarvian area, central Iran

Science.gov (United States)

Mansouri, Edris; Feizi, Faranak; Jafari Rad, Alireza; Arian, Mehran

2018-03-01

This paper uses multivariate regression to create a mathematical model for iron skarn exploration in the Sarvian area, central Iran, using multivariate regression for mineral prospectivity mapping (MPM). The main target of this paper is to apply multivariate regression analysis (as an MPM method) to map iron outcrops in the northeastern part of the study area in order to discover new iron deposits in other parts of the study area. Two types of multivariate regression models using two linear equations were employed to discover new mineral deposits. This method is one of the reliable methods for processing satellite images. ASTER satellite images (14 bands) were used as unique independent variables (UIVs), and iron outcrops were mapped as dependent variables for MPM. According to the results of the probability value (p value), coefficient of determination value (R2) and adjusted determination coefficient (Radj2), the second regression model (which consistent of multiple UIVs) fitted better than other models. The accuracy of the model was confirmed by iron outcrops map and geological observation. Based on field observation, iron mineralization occurs at the contact of limestone and intrusive rocks (skarn type).

Product and process innovation of grey cast iron brake discs

Energy Technology Data Exchange (ETDEWEB)

Schorn, M. [Brembo S.P.A. (Italy)

2006-07-01

The brake disc out of grey cast iron often seems to be playing the role of the ''underdog'' in the technical examinations of the entire brake system. This is also reflected by the 25 year history of the {mu}-club. In a total of 93 presentations in those 25 years, only 3 were related to the topic of grey cast iron discs. This is not a correct relation to the importance of this component within the brake system. The disc, although per definition with a lower specific load than the pad, has the major task to store and dissipate the heat in which the kinetic energy of the vehicle is transformed. The disc also has a significant effect on NVH behaviour, particularly in the low frequency range. It also has a permanent fight with its weight as an unsprung mass. (orig.)

Iron-Deficiency Anemia

Science.gov (United States)

... To Health Topics / Iron-Deficiency Anemia Iron-Deficiency Anemia Also known as Leer en español Iron-deficiency ... anemia. Blood tests to screen for iron-deficiency anemia To screen for iron-deficiency anemia, your doctor ...

A novel process for recovery of iron, titanium, and vanadium from titanomagnetite concentrates: NaOH molten salt roasting and water leaching processes

International Nuclear Information System (INIS)

Chen, Desheng; Zhao, Longsheng; Liu, Yahui; Qi, Tao; Wang, Jianchong; Wang, Lina

2013-01-01

Highlights: ► The conversion of titanium is 96.6% in the rich titanium–vanadium slag. ► MgTi 2 O 5 and M 3 O 5 (M = Ti, Mg, Fe) were converted to Na 2 TiO 3 and NaMO 2 , respectively. ► Na 2 TiO 3 is converted to undefined structure of H 2 TiO 3 . ► NaMO 2 is converted to α-NaFeO 2 -type structure of HMO 2 . ► 87.3% of sodium, 42.3% of silicon, 43.2% of aluminum, 22.8% of manganese and 96.6% of vanadium were leached out. -- Abstract: A novel process for recovering iron, titanium, and vanadium from titanomagnetite concentrates has been developed. In the present paper, the treatment of rich titanium–vanadium slag by NaOH molten salt roasting and water leaching processes is investigated. In the NaOH molten salt roasting process, the metallic iron is oxidized into ferriferous oxide, MgTi 2 O 5 is converted to NaCl-type structure of Na 2 TiO 3 , and M 3 O 5 (M = Ti, Mg, Fe) is converted to α-NaFeO 2 -type structure of NaMO 2 , respectively. Roasting temperature and NaOH–slag mass ratio played a considerable role in the conversion of titanium in the rich titanium–vanadium slag during the NaOH molten salt roasting process. Roasting at 500 °C for 60 min and a 1:1 NaOH–slag mass ratio produces 96.3% titanium conversion. In the water leaching process, the Na + was exchanged with H + , Na 2 TiO 3 is converted to undefined structure of H 2 TiO 3 , and NaMO 2 is converted to α-NaFeO 2 -type structure of HMO 2 . Under the optimal conditions, 87.3% of the sodium, 42.3% of the silicon, 43.2% of the aluminum, 22.8% of the manganese, and 96.6% of the vanadium are leached out

Rhombohedral iron trifluoride with a hierarchized macroporous/mesoporous texture from gaseous fluorination of iron disilicide

Energy Technology Data Exchange (ETDEWEB)

Guérin, Katia, E-mail: katia.araujo_da_silva@univ-bpclermont.fr [Université Clermont Auvergne, Université Blaise Pascal, Institut de Chimie de Clermont-Ferrand, BP 10448, F-63000 Clermont-Ferrand (France); CNRS, UMR 6296, ICCF, F-63171 Aubière (France); Delbègue, Diane; Louvain, Nicolas; Doubtsof, Léa; Hamwi, André [Université Clermont Auvergne, Université Blaise Pascal, Institut de Chimie de Clermont-Ferrand, BP 10448, F-63000 Clermont-Ferrand (France); CNRS, UMR 6296, ICCF, F-63171 Aubière (France); Laik, Barbara; Pereira-Ramos, Jean-Pierre [Université Paris Est Créteil, Institut de Chimie et des Matériaux Paris-Est, UMR CNRS 7182, Thiais (France); Tahar-sougrati, Moulay; Jumas, Jean-Claude [Université Montpellier II, Institut Charles Gerhardt de Montpellier, UMR CNRS 5253, Montpellier (France); Willmann, Patrick; Cénac-Morthe, Céline [Centre National d' Etudes Spatiales, Toulouse (France)

2016-04-15

Stable low temperature rhombohedral iron trifluoride has been obtained by the fluorination under the pure fluorine gas of iron disilicide. The combination of both unusual fluorination process and precursor avoids to get unhydrated crystalline FeF{sub 3} particles and allows the formation of hierarchized channels of mesoporous/macroporous texture favorable for lithium diffusion. The fluorination mechanism proceeds by temperature steps from the formation, for a fluorination temperature below 200 °C, of an amorphous phase and an intermediate iron difluoride identified mainly by {sup 57}Fe Mössbauer spectroscopy before getting, as soon as a fluorination temperature of 260 °C is reached, the rhombohedral FeF{sub 3}. Both amorphous and crystallized samples display good ability for electrochemical process when used as cathode in lithium-ion battery. The low diameter of rhombohedral structure channels is balanced by an appropriate mesoporous texture and a capacity of 225 mAh.g{sup −1} after 5 cycles for a discharge cut-off of 2.5 V vs. Li{sup +}/Li at a current density of C/20 has been obtained and stabilized at 95 mAh.g{sup −1} after 116 cycles. - Highlights: • We investigated the synthesis of rhombohedral FeF{sub 3} by solid–gas reaction from iron disilicide. • We demonstrated that depending on the fluorination temperature various phases are stabilized. • We got a hierarchized macroporous/mesoporous texture. • We studied the electrochemical performances of amorphous and crystallized FeF{sub 3}. • Crystallized FeF{sub 3} presents a high faradic yield at first cycle focusing on insertion process.

Ultrasonic Real-Time Quality Monitoring Of Aluminum Spot Weld Process

Science.gov (United States)

Perez Regalado, Waldo Josue

The real-time ultrasonic spot weld monitoring system, introduced by our research group, has been designed for the unsupervised quality characterization of the spot welding process. It comprises the ultrasonic transducer (probe) built into one of the welding electrodes and an electronics hardware unit which gathers information from the transducer, performs real-time weld quality characterization and communicates with the robot programmable logic controller (PLC). The system has been fully developed for the inspection of spot welds manufactured in steel alloys, and has been mainly applied in the automotive industry. In recent years, a variety of materials have been introduced to the automotive industry. These include high strength steels, magnesium alloys, and aluminum alloys. Aluminum alloys have been of particular interest due to their high strength-to-weight ratio. Resistance spot welding requirements for aluminum vary greatly from those of steel. Additionally, the oxide film formed on the aluminum surface increases the heat generation between the copper electrodes and the aluminum plates leading to accelerated electrode deterioration. Preliminary studies showed that the real-time quality inspection system was not able to monitor spot welds manufactured with aluminum. The extensive experimental research, finite element modelling of the aluminum welding process and finite difference modeling of the acoustic wave propagation through the aluminum spot welds presented in this dissertation, revealed that the thermodynamics and hence the acoustic wave propagation through an aluminum and a steel spot weld differ significantly. For this reason, the hardware requirements and the algorithms developed to determine the welds quality from the ultrasonic data used on steel, no longer apply on aluminum spot welds. After updating the system and designing the required algorithms, parameters such as liquid nugget penetration and nugget diameter were available in the ultrasonic data

Effects of microstructure and local mechanical fields on intergranular stress corrosion cracking of a friction stir welded aluminum–copper–lithium 2050 nugget

International Nuclear Information System (INIS)

Dhondt, Matthieu; Aubert, Isabelle; Saintier, Nicolas; Olive, Jean Marc

2014-01-01

Highlights: • Applied stress changes the corrosion mode from pitting to intergranular cracking. • Residual stresses are sufficient to induce intergranular stress corrosion cracking. • Effect of crystallographic texture on the development of IGSCC evidenced by EBSD. • Cubic elasticity drives the local orientation of the intergranular cracking. • Tomography observations show the 3D nature of the corrosion development. - Abstract: The effects of the microstructure and mechanical fields on intergranular stress corrosion cracking (IGSCC) of the nugget zone of heat treated welds obtained by friction stir welding in the AA2050 aluminum alloy have been investigated at different scales. At low strain rate, in 1.0 NaCl aqueous solution, IGSCC develops in the microstructure, whereas only pitting corrosion is observed without any mechanical stress. Based on surface observations, EBSD analysis and X-ray tomography, the key role of sub-millimetric textured bands (induced by the welding process) on the IGSCC is demonstrated. Analyses at a more local scale show the grain boundary (low angle boundary, special coincident site lattice boundary or high angle boundary) do not have a significant effect on crack initiation. Crystal plasticity finite element calculations show that the threshold normal stress at grain boundaries for IGSCC development is about 80% of the macroscopic stress. It is also highlighted by crystal plasticity calculations that there is a drastic effect of the local stress field on the shape of cracks. Finally, it is shown that plasticity induced residual stresses are sufficient for the formation of IGSCC

Magnetic and quadrupolar studies of the iron storage overload in livers

International Nuclear Information System (INIS)

Rimbert, J.N.; Dumas, F.; Richardot, G.; Kellershohn, C.

1986-01-01

Absorption 57 Fe Moessbauer spectra, performed directly on tissues of liver with iron overload due to an excessive intestinal iron absorption or induced by hypertransfusional therapeutics, have pointed out a new high spin ferric storage iron besides the ferritin and hemosiderin. Moessbauer studies, carried out on ferritin and hemosiderin fractions isolated from normal and overloaded livers, show that this compound, only present in the secondary iron overload (transfusional pathway), seems characteristic of the physiological process which induces the iron overload. (Auth.)

Iron-Deficiency Anemia

Medline Plus

Full Text Available ... risk for iron-deficiency anemia, including: Vegetarian or vegan eating patterns. Not eating enough iron-rich foods, ... iron-fortified foods that have iron added. Vegetarian diets can provide enough iron if you choose nonmeat ...

Influence of heat processing on the bioaccessibility of zinc and iron from cereals and pulses consumed in India.

Science.gov (United States)

Hemalatha, Sreeramaiah; Platel, Kalpana; Srinivasan, Krishnapura

2007-01-01

Influence of heat processing on the bioaccessibility of zinc and iron from food grains consumed in India was evaluated. Cereals - rice (Oryza sativa), finger millet (Eleusine coracana), sorghum (Sorghum vulgare), wheat (Triticum aestivum), and maize (Zea mays), and pulses - chickpea (Cicer arietinum) - whole and decorticated, green gram (Phaseolus aureus) - whole and decorticated, decorticated black gram (Phaseolus mungo), decorticated red gram (Cajanus cajan), cowpea (Vigna catjang), and French bean (Phaseolus vulgaris) were examined for zinc and iron bioaccessibility by employing an in vitro dialysability procedure. Both pressure-cooking and microwave heating were tested for their influence on mineral bioaccessibility. Zinc bioaccessibility from food grains was considerably reduced upon pressure-cooking, especially in pulses. Among cereals, pressure-cooking decreased zinc bioaccessibility by 63% and 57% in finger millet and rice, respectively. All the pressure-cooked cereals showed similar percent zinc bioaccessibility with the exception of finger millet. Bioaccessibility of zinc from pulses was generally lower as a result of pressure-cooking or microwave heating. The decrease in bioaccessibility of zinc caused by microwave heating ranged from 11.4% in chickpea (whole) to 63% in cowpea. Decrease in zinc bioaccessibility was 48% in pressure-cooked whole chickpea, 45% and 55% in pressure-cooked or microwave-heated whole green gram, 32% and 22% in pressure-cooked or microwave-heated decorticated green gram, and 45% in microwave-heated black gram. Iron bioaccessibility, on the other hand, was significantly enhanced generally from all the food grains studied upon heat treatment. Thus, heat treatment of grains produced contrasting effect on zinc and iron bioaccessibility.

Evaluation of the mercaptobenzothiazole degradation by combined adsorption process and Fenton reaction using iron mining residue.

Science.gov (United States)

Martins, Adriana Lau da Silva; Teixeira, Luís Alberto César; da Fonseca, Fabiana Valéria; Yokoyama, Lídia

2017-08-01

The present study investigated the degradation of mercaptobenzothiazole (MBT), evaluating homogeneous and heterogeneous systems. An iron mineral residue from the desliming step of iron mining was used as a source in the Fenton-like reaction (advanced oxidation process). A granulometric analysis of the residue was performed and yielded fractions with high hematite (Fe 2 O 3 ) and low quartz content in sieves from 74 to below 44 mm. In this particle size range, the hematite content from 58.9% to 67.4% and the Brunauer-Emmett-Teller area from 0.1345 to 1.3137 m 2  g -1 were obtained. The zeta potential curves as a function of pH were obtained for the residue, the MBT solution and mixtures thereof. The adsorption of MBT in the residue and its degradation through the Fenton-like reaction were investigated. Adsorption tests and the Fenton-like reaction were carried out, where the MBT species and the residue are oppositely charged, yielding, respectively, 10% MBT adsorption on the surface of the residue and 100% MBT degradation by the Fenton-like reaction at pH 3, hydrogen peroxide concentration of 25 mg L -1 , residue concentration of 3 g L -1 , 200 rpm and 25°C, from a 100 mg L -1 MBT solution. MBT degradation was found to occur mainly by the heterogeneous Fenton-like process.

Effect of shot peening process on fatigue behavior of an alloyed austempered ductile iron

Directory of Open Access Journals (Sweden)

Amir Sadighzadeh Benam

2011-08-01

Full Text Available Shot peening is one of the most common surface treatments to improve the fatigue behavior of metallic parts. In this study the effect of shot peening process on the fatigue behavior of an alloyed austempered ductile iron (ADI has been studied. Austempering heat treatment consisted of austenitizing at 875℃ for 90 min followed by austempering at three different temperatures of 320, 365 and 400℃. Rotating-bending fatigue test was carried out on samples after shot peening by 0.4 – 0.6 mm shots. XRD and SEM analysis, micro hardness and roughness tests were carried out to study the fatigue behavior of the samples. Results indicate that the fatigue strengths of samples austempered at 320, 365 and 400℃ are increased by 27.3%, 33.3% and 48.4%, respectively, after shot peening process.

Iron-Deficiency Anemia

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Full Text Available ... Iron-Deficiency Anemia Iron-Deficiency Anemia Also known as Leer en español Iron-deficiency anemia is a ... address the cause of your iron deficiency, such as any underlying bleeding. If undiagnosed or untreated, iron- ...

Iron-Deficiency Anemia

Medline Plus

Full Text Available ... To Health Topics / Iron-Deficiency Anemia Iron-Deficiency Anemia Also known as Leer en español Iron-deficiency ... anemia. Blood tests to screen for iron-deficiency anemia To screen for iron-deficiency anemia, your doctor ...

High purity Fe3O4 from Local Iron Sand Extraction

Science.gov (United States)

Gunanto, Y. E.; Izaak, M. P.; Jobiliong, E.; Cahyadi, L.; Adi, W. A.

2018-04-01

Indonesia has a long coastline and is rich with iron sand. The iron sand is generally rich in various elements such as iron and titanium. One of the products processing of the iron sand mineral is iron (II) (III) oxide (magnetite Fe3O4). The stages of purification process to extracting magnetite phase and discarding the other phases has been performed. Magnetite phase analysis of ironsand extraction retrieved from Indonesia have been investigated. The result of analysis element of iron sand shows that it consists of majority Fe around 65 wt%. However, there are still 17 impurities such as Ti, Al, Ce, Co, Cr, Eu, La, Mg, Mn, Na, Sc, Sm, Th, V, Yb, and Zn. After extraction process, Fe element content increases up to 94%. The iron sand powder after milling for 10 hours and separating using a magnetic separator, the iron sand powders are dissolved in acid chloride solution to form a solution of iron chloride, and this solution is sprinkled with sodium hydroxide to obtain fine powders of Fe3O4. The fine powders which formed were washed with de-mineralization water. The X-ray diffraction pattern shows that the fine powders have a single phase of Fe3O4. The analysis result shows that the sample has the chemical formula: Fe3O4 with a cubic crystal system, space group: Fd-3m and lattice parameters: a = b = c = 8.3681 (1) Å, α = β = γ = 90°. The microstructure analysis shows that the particle of Fe3O4 homogeneously shaped like spherical. The magnetic properties using vibrating sample magnetometer shows that Fe3O4 obtained have ferromagnetic behavior with soft magnetic characteristics. We concluded that this purification of iron sand had been successfully performed to obtain fine powders of Fe3O4 with high purity.

Review of iron oxides for water treatment

International Nuclear Information System (INIS)

Navratil, J. D.

2001-01-01

Many processes have utilized iron oxides for the treatment of liquid wastes containing radioactive and hazardous metals. These processes have included adsorption, precipitation and other chemical and physical techniques. For example, a radioactive wastewater precipitation process includes addition of a ferric hydroxide floc to scavenge radioactive contaminants, such as americium, plutonium and uranium. Some adsorption processes for wastewater treatment have utilized ferrites and a variety of iron containing minerals. Various ferrites and natural magnetite were used in batch modes for actinide and heavy metal removal from wastewater. Supported magnetite was also used in a column mode, and in the presence of an external magnetic field, enhanced capacity was found for removal of plutonium and americium from wastewater. These observations were explained by a nano-level high gradient magnetic separation effect, as americium, plutonium and other hydrolytic metals are known to form colloidal particles at elevated pHs. Recent modeling work supports this assumption and shows that the smaller the magnetite particle the larger the induced magnetic field around the particle from the external field. Other recent studies have demonstrated the magnetic enhanced removal of arsenic, cobalt and iron from simulated groundwater. (author)

Serum iron and total iron binding capacity levels among the abo ...

African Journals Online (AJOL)

Iron deficiency anaemia is a common tropical disease. Iron plays a very important role in the human body. The understanding of the different blood groups ability to retain iron in their system can give an insight into their ability to handle the disease Iron deficiency anaemia. Serum Iron, Total Iron Binding Capacity (TIBC) and ...

Zinc deficiency-induced iron accumulation, a consequence of alterations in iron regulatory protein-binding activity, iron transporters, and iron storage proteins.

Science.gov (United States)

Niles, Brad J; Clegg, Michael S; Hanna, Lynn A; Chou, Susan S; Momma, Tony Y; Hong, Heeok; Keen, Carl L

2008-02-22

One consequence of zinc deficiency is an elevation in cell and tissue iron concentrations. To examine the mechanism(s) underlying this phenomenon, Swiss 3T3 cells were cultured in zinc-deficient (D, 0.5 microM zinc), zinc-supplemented (S, 50 microM zinc), or control (C, 4 microM zinc) media. After 24 h of culture, cells in the D group were characterized by a 50% decrease in intracellular zinc and a 35% increase in intracellular iron relative to cells in the S and C groups. The increase in cellular iron was associated with increased transferrin receptor 1 protein and mRNA levels and increased ferritin light chain expression. The divalent metal transporter 1(+)iron-responsive element isoform mRNA was decreased during zinc deficiency-induced iron accumulation. Examination of zinc-deficient cells revealed increased binding of iron regulatory protein 2 (IRP2) and decreased binding of IRP1 to a consensus iron-responsive element. The increased IRP2-binding activity in zinc-deficient cells coincided with an increased level of IRP2 protein. The accumulation of IRP2 protein was independent of zinc deficiency-induced intracellular nitric oxide production but was attenuated by the addition of the antioxidant N-acetylcysteine or ascorbate to the D medium. These data support the concept that zinc deficiency can result in alterations in iron transporter, storage, and regulatory proteins, which facilitate iron accumulation.

You can't "nudge" nuggets: An investigation of college late-night dining with behavioral economics interventions.

Science.gov (United States)

Bevet, Samuel; Niles, Meredith T; Pope, Lizzy

2018-01-01

A mixed-methods approach was used to evaluate and improve the "late-night dining" options in a university dining hall. Surveys assessed student desires for late-night offerings, and evaluated students' habits and motivations during late-night dining. Two interventions were implemented to see if students could be "nudged" into different choice patterns. In the first, a "veggie-heavy" entrée was added at the beginning of the entrée line, so that students would substitute an entrée containing vegetables for the alternatives. In the second, a snack-food bar was set up to cater to students who didn't want to stand in the long entrée line, and preferred a snack. Data on food choice was collected during the interventions. Survey responses showed significant differences in the reasons females and males utilized late-night dining (p<0.001). We also found that students at late-night dining had a lower emphasis on health than the general student population. Even students at late-night who reported being health-conscious showed no difference in food selections from students who said health was not important (p = 0.883). Veggie-heavy entrées had mild success in increasing vegetable selection. However, veggie-heavy entrées were largely ignored when the other option was chicken nuggets. The snack bar was very popular. Entrée placement and convenience lines may have mild impacts on food selection in a late-night dining environment.

Iron oxyhydroxide mineralization on microbial extracellular polysaccharides

Energy Technology Data Exchange (ETDEWEB)

Chan, Clara S.; Fakra, Sirine C.; Edwards, David C.; Emerson, David; Banfield, Jillian F.

2010-06-22

Iron biominerals can form in neutral pH microaerophilic environments where microbes both catalyze iron oxidation and create polymers that localize mineral precipitation. In order to classify the microbial polymers that influence FeOOH mineralogy, we studied the organic and mineral components of biominerals using scanning transmission X-ray microscopy (STXM), micro X-ray fluorescence ({mu}XRF) microscopy, and high-resolution transmission electron microscopy (HRTEM). We focused on iron microbial mat samples from a creek and abandoned mine; these samples are dominated by iron oxyhydroxide-coated structures with sheath, stalk, and filament morphologies. In addition, we characterized the mineralized products of an iron-oxidizing, stalk-forming bacterial culture isolated from the mine. In both natural and cultured samples, microbial polymers were found to be acidic polysaccharides with carboxyl functional groups, strongly spatially correlated with iron oxyhydroxide distribution patterns. Organic fibrils collect FeOOH and control its recrystallization, in some cases resulting in oriented crystals with high aspect ratios. The impact of polymers is particularly pronounced as the materials age. Synthesis experiments designed to mimic the biomineralization processes show that the polysaccharide carboxyl groups bind dissolved iron strongly but release it as mineralization proceeds. Our results suggest that carboxyl groups of acidic polysaccharides are produced by different microorganisms to create a wide range of iron oxyhydroxide biomineral structures. The intimate and potentially long-term association controls the crystal growth, phase, and reactivity of iron oxyhydroxide nanoparticles in natural systems.

The "Iron Inventor": Using Creative Problem Solving to Spur Student Creativity

Science.gov (United States)

Lee, Seung Hwan; Hoffman, K. Douglas

2014-01-01

Based on the popular television show the "Iron Chef," an innovative marketing activity called the "Iron Inventor" is introduced. Using the creative problem-solving approach and active learning techniques, the Iron Inventor facilitates student learning pertaining to the step-by-step processes of creating a new product and…

Determining the Effect of Environmental Conditions on Iron Corrosion by Atomic Absorption

Science.gov (United States)

Malel, Esteban; Shalev, Deborah E.

2013-01-01

Iron corrosion is a complex process that occurs when iron is exposed to oxygen and humidity and is exacerbated by the presence of chloride ions. The deterioration of iron structures or other components can be costly to society and is usually evaluated by following the properties of the corroding material. Here, the iron ions released into solution…

Iron-binding haemerythrin RING ubiquitin ligases regulate plant iron responses and accumulation

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Kobayashi, Takanori; Nagasaka, Seiji; Senoura, Takeshi; Itai, Reiko Nakanishi; Nakanishi, Hiromi; Nishizawa, Naoko K.

2013-01-01

Iron is essential for most living organisms. Plants transcriptionally induce genes involved in iron acquisition under conditions of low iron availability, but the nature of the deficiency signal and its sensors are unknown. Here we report the identification of new iron regulators in rice, designated Oryza sativa Haemerythrin motif-containing Really Interesting New Gene (RING)- and Zinc-finger protein 1 (OsHRZ1) and OsHRZ2. OsHRZ1, OsHRZ2 and their Arabidopsis homologue BRUTUS bind iron and zinc, and possess ubiquitination activity. OsHRZ1 and OsHRZ2 are susceptible to degradation in roots irrespective of iron conditions. OsHRZ-knockdown plants exhibit substantial tolerance to iron deficiency, and accumulate more iron in their shoots and grains irrespective of soil iron conditions. The expression of iron deficiency-inducible genes involved in iron utilization is enhanced in OsHRZ-knockdown plants, mostly under iron-sufficient conditions. These results suggest that OsHRZ1 and OsHRZ2 are iron-binding sensors that negatively regulate iron acquisition under conditions of iron sufficiency. PMID:24253678

Extracting phosphoric iron under laboratorial conditions smelting bog iron ores

International Nuclear Information System (INIS)

Török, B; Thiele, A

2013-01-01

In recent years it has been indicated by archaeometric investigations that phosphoric-iron (P-iron, low carbon steel with 0,5-1,5wt% P), which is an unknown and unused kind of steel in the modern industry, was widely used in different parts of the world in medieval times. In this study we try to explore the role of phosphorus in the arhaeometallurgy of iron and answer some questions regarding the smelting bog iron ores with high P-content. XRF analyses were performed on bog iron ores collected in Somogy county. Smelting experiments were carried out on bog iron ores using a laboratory model built on the basis of previously conducted reconstructed smelting experiments in copies of excavated furnaces. The effect of technological parameters on P-content of the resulted iron bloom was studied. OM and SEM-EDS analyses were carried out on the extracted iron and slag samples. On the basis of the material analyses it can be stated that P-iron is usually extracted but the P-content is highly affected by technological parameters. Typical microstructures of P-iron and of slag could also be identified. It could also be established that arsenic usually solved in high content in iron as well

Iron Therapy in Patients with Heart Failure and Iron Deficiency: Review of Iron Preparations for Practitioners.

Science.gov (United States)

Drozd, Marcin; Jankowska, Ewa A; Banasiak, Waldemar; Ponikowski, Piotr

2017-06-01

In patients with heart failure (HF), iron deficiency (ID) correlates with decreased exercise capacity and poor health-related quality of life, and predicts worse outcomes. Both absolute (depleted iron stores) and functional (where iron is unavailable for dedicated tissues) ID can be easily evaluated in patients with HF using standard laboratory tests (assessment of serum ferritin and transferrin saturation). Intravenous iron therapy in iron-deficient patients with HF and reduced ejection fraction has been shown to alleviate HF symptoms and improve exercise capacity and quality of life. In this paper, we provide information on how to diagnose ID in HF. Further we discuss pros and cons of different iron preparations and discuss the results of major trials implementing iron supplementation in HF patients, in order to provide practical guidance for clinicians on how to manage ID in patients with HF.

Siderophore-mediated iron trafficking in humans is regulated by iron

Science.gov (United States)

Liu, Zhuoming; Lanford, Robert; Mueller, Sebastian; Gerhard, Glenn S.; Luscieti, Sara; Sanchez, Mayka; Devireddy, L.

2013-01-01

Siderophores are best known as small iron binding molecules that facilitate microbial iron transport. In our previous study we identified a siderophore-like molecule in mammalian cells and found that its biogenesis is evolutionarily conserved. A member of the short chain dehydrogenase family of reductases, 3-OH butyrate dehydrogenase (BDH2) catalyzes a rate-limiting step in the biogenesis of the mammalian siderophore. We have shown that depletion of the mammalian siderophore by inhibiting expression of bdh2 results in abnormal accumulation of cellular iron and mitochondrial iron deficiency. These observations suggest that the mammalian siderophore is a critical regulator of cellular iron homeostasis and facilitates mitochondrial iron import. By utilizing bioinformatics, we identified an iron-responsive element (IRE; a stem-loop structure that regulates genes expression post-transcriptionally upon binding to iron regulatory proteins or IRPs) in the 3′-untranslated region (3′-UTR) of the human BDH2 (hBDH2) gene. In cultured cells as well as in patient samples we now demonstrate that the IRE confers iron-dependent regulation on hBDH2 and binds IRPs in RNA electrophoretic mobility shift assays. In addition, we show that the hBDH2 IRE associates with IRPs in cells and that abrogation of IRPs by RNAi eliminates the iron-dependent regulation of hBDH2 mRNA. The key physiologic implication is that iron-mediated post-transcriptional regulation of hBDH2 controls mitochondrial iron homeostasis in human cells. These observations provide a new and an unanticipated mechanism by which iron regulates its intracellular trafficking. PMID:22527885

Computer-aided control of high-quality cast iron

Directory of Open Access Journals (Sweden)

S. Pietrowski

2008-04-01

Full Text Available The study discusses the possibility of control of the high-quality grey cast iron and ductile iron using the author’s genuine computer programs. The programs have been developed with the help of algorithms based on statistical relationships that are said to exist between the characteristic parameters of DTA curves and properties, like Rp0,2, Rm, A5 and HB. It has been proved that the spheroidisation and inoculation treatment of cast iron changes in an important way the characteristic parameters of DTA curves, thus enabling a control of these operations as regards their correctness and effectiveness, along with the related changes in microstructure and mechanical properties of cast iron. Moreover, some examples of statistical relationships existing between the typical properties of ductile iron and its control process were given for cases of the melts consistent and inconsistent with the adopted technology.A test stand for control of the high-quality cast iron and respective melts has been schematically depicted.

Microwave-Assisted Combustion Synthesis of Nano Iron Oxide/Iron-Coated Activated Carbon, Anthracite, Cellulose Fiber, and Silica, with Arsenic Adsorption Studies

Directory of Open Access Journals (Sweden)

Mallikarjuna N. Nadagouda

2011-01-01

Full Text Available Combustion synthesis of iron oxide/iron coated carbons such as activated carbon, anthracite, cellulose fiber, and silica is described. The reactions were carried out in alumina crucibles using a Panasonic kitchen microwave with inverter technology, and the reaction process was completed within a few minutes. The method used no additional fuel and nitrate, which is present in the precursor itself, to drive the reaction. The obtained samples were then characterized with X-ray mapping, scanning electron microscopy (SEM, energy dispersive X-ray analysis (EDS, selected area diffraction pattern (SAED, transmission electron microscopy (TEM, X-ray diffraction (XRD, and inductively coupled plasma (ICP spectroscopy. The size of the iron oxide/iron nanoparticle-coated activated carbon, anthracite, cellulose fiber, and silica samples were found to be in the nano range (50–400 nm. The iron oxide/iron nanoparticles mostly crystallized into cubic symmetry which was confirmed by SAED. The XRD pattern indicated that iron oxide/iron nano particles existed in four major phases. That is, γ-Fe2O3, α-Fe2O3, Fe3O4, and Fe. These iron-coated activated carbon, anthracite, cellulose fiber, and silica samples were tested for arsenic adsorption through batch experiments, revealing that few samples had significant arsenic adsorption.

Effect of atmospheric organic complexation on iron-bearing dust solubility

Directory of Open Access Journals (Sweden)

R. Paris

2013-05-01

Full Text Available Recent studies reported that the effect of organic complexation may be a potentially important process to be considered by models estimating atmospheric iron flux to the ocean. In this study, we investigated this process effect by a series of dissolution experiments on iron-bearing dust in the presence or the absence of various organic compounds (acetate, formate, oxalate, malonate, succinate, glutarate, glycolate, lactate, tartrate and humic acid as an analogue of humic like substances, HULIS typically found in atmospheric waters. Only 4 of tested organic ligands (oxalate, malonate, tartrate and humic acid caused an enhancement of iron solubility which was associated with an increase of dissolved Fe(II concentrations. For all of these organic ligands, a positive linear dependence of iron solubility to organic concentrations was observed and showed that the extent of organic complexation on iron solubility decreased in the following order: oxalate >malonate = tartrate > humic acid. This was attributed to the ability of electron donors of organic ligands and implies a reductive ligand-promoted dissolution. This study confirms that among the known atmospheric organic binding ligands of Fe, oxalate is the most effective ligand promoting dust iron solubility and showed, for the first time, the potential effect of HULIS on iron dissolution under atmospheric conditions.

Effect of internal gettering of iron on electrical characteristics of devices

International Nuclear Information System (INIS)

Talvitie, H.; Haarahiltunen, A.; Savin, H.; Yli-Koski, M.; Asghar, M.I.; Sinkkonen, J.

2009-01-01

Different types of gettering treatments were applied to a real device process to evaluate their ability to remove iron contamination from the device layer and improve the electrical characteristics of the devices. NMOS and PMOS transistors and other test structures were manufactured on boron doped, both iron contaminated and uncontaminated Cz silicon wafers with or without gettering treatment. Gettering treatments, which were designed to induce sufficient iron precipitate nucleation in the bulk to ensure iron precipitation, were inserted in the fabrication process after the last high temperature treatment in which the iron solubility was higher than the contamination level. The electrical characteristics of the devices, such as leakage currents, were measured. The applied gettering treatments were found to be inefficient to improve the device performance, possibly due to stronger gettering to heavily doped, ion implantation damaged device layer.

Ultrasonic diagnosis of spot welding in thin plates

International Nuclear Information System (INIS)

Kim, No You; Hong, Min Sung

2005-01-01

Spot welding widely used in automotive and aerospace industries has made it possible to produce more precise and smaller electric part by robotization and systemization of welding process. The quality of welding depends upon the size of nugget between the overlapped steel plates. Recently, the thickness of the steel plates becomes much thinner and hence, it introduces the smaller size of nugget. Therefore, it is necessary to develop the criterion to evaluate the quality of weld in order to obtain the optimal welding conditions for the better performance. In this paper, a thin steel plates, 0.1 mm through 0.3 mm thickness, have been spot-welded at different welding conditions and the nugget sizes are examined by defocused scanning microscopy. The relationships between nugget sizes and weldability have been investigated experimentally. The result of ultrasonic technique shows the good agreement with that of the tensile test.

New insights into iron deficiency and iron deficiency anemia.

Science.gov (United States)

Camaschella, Clara

2017-07-01

Recent advances in iron metabolism have stimulated new interest in iron deficiency (ID) and its anemia (IDA), common conditions worldwide. Absolute ID/IDA, i.e. the decrease of total body iron, is easily diagnosed based on decreased levels of serum ferritin and transferrin saturation. Relative lack of iron in specific organs/tissues, and IDA in the context of inflammatory disorders, are diagnosed based on arbitrary cut offs of ferritin and transferrin saturation and/or marker combination (as the soluble transferrin receptor/ferritin index) in an appropriate clinical context. Most ID patients are candidate to traditional treatment with oral iron salts, while high hepcidin levels block their absorption in inflammatory disorders. New iron preparations and new treatment modalities are available: high-dose intravenous iron compounds are becoming popular and indications to their use are increasing, although long-term side effects remain to be evaluated. Copyright © 2017 Elsevier Ltd. All rights reserved.

High solubility pathway for the carbon dioxide free production of iron.

Science.gov (United States)

Licht, Stuart; Wang, Baohui

2010-10-07

We report a fundamental change in the understanding of iron oxide thermochemistry, opening a facile, new CO(2)-free route to iron production. The resultant process can eliminate a major global source of greenhouse gas emission, producing the staple iron in molten media at high rate and low electrolysis energy.