Sample records for hot reduced iron
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Metagenomic Study of Iron Homeostasis in Iron Depositing Hot Spring Cyanobacterial Community
Brown, I.; Franklin H.; Tringe, S. G.; Klatt, C. G.; Bryant, D. A.; Sarkisova, S. A.; Guevara, M.
2010-01-01
Introduction: It is not clear how an iron-rich thermal hydrosphere could be hospitable to cyanobacteria, since reduced iron appears to stimulate oxidative stress in all domains of life and particularly in oxygenic phototrophs. Therefore, metagenomic study of cyanobacterial community in iron-depositing hot springs may help elucidate how oxygenic prokaryotes can withstand the extremely high concentrations of reactive oxygen species (ROS) produced by interaction between environmental Fe2+ and O2. Method: Anchor proteins from various species of cyanobacteria and some anoxygenic phototrophs were selected on the basis of their hypothetical role in Fe homeostasis and the suppression of oxidative stress and were BLASTed against the metagenomes of iron-depositing Chocolate Pots and freshwater Mushroom hot springs. Results: BLASTing proteins hypothesized to be involved in Fe homeostasis against the microbiomes from the two springs revealed that iron-depositing hot spring has a greater abundance of defensive proteins such as bacterioferritin comigratory protein (Bcp) and DNA-binding Ferritin like protein (Dps) than a fresh-water hot spring. One may speculate that the abundance of Bcp and Dps in an iron-depositing hot spring is connected to the need to suppress oxidative stress in bacteria inhabiting environments with high Fe2+ concnetration. In both springs, Bcp and Dps are concentrated within the cyanobacterial fractions of the microbial community (regardless of abundance). Fe3+ siderophore transport (from the transport system permease protein query) may be less essential to the microbial community of CP because of the high [Fe]. Conclusion: Further research is needed to confirm that these proteins are unique to photoautotrophs such as those living in iron-depositing hot spring.
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Pierson, B. K.; Parenteau, M. N.; Griffin, B. M.
1999-01-01
At Chocolate Pots Hot Springs in Yellowstone National Park the source waters have a pH near neutral, contain high concentrations of reduced iron, and lack sulfide. An iron formation that is associated with cyanobacterial mats is actively deposited. The uptake of [(14)C]bicarbonate was used to assess the impact of ferrous iron on photosynthesis in this environment. Photoautotrophy in some of the mats was stimulated by ferrous iron (1.0 mM). Microelectrodes were used to determine the impact of photosynthetic activity on the oxygen content and the pH in the mat and sediment microenvironments. Photosynthesis increased the oxygen concentration to 200% of air saturation levels in the top millimeter of the mats. The oxygen concentration decreased with depth and in the dark. Light-dependent increases in pH were observed. The penetration of light in the mats and in the sediments was determined. Visible radiation was rapidly attenuated in the top 2 mm of the iron-rich mats. Near-infrared radiation penetrated deeper. Iron was totally oxidized in the top few millimeters, but reduced iron was detected at greater depths. By increasing the pH and the oxygen concentration in the surface sediments, the cyanobacteria could potentially increase the rate of iron oxidation in situ. This high-iron-content hot spring provides a suitable model for studying the interactions of microbial photosynthesis and iron deposition and the role of photosynthesis in microbial iron cycling. This model may help clarify the potential role of photosynthesis in the deposition of Precambrian banded iron formations.
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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
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Directory of Open Access Journals (Sweden)
Morcali M.H.
2016-01-01
Full Text Available The growing use of metallic iron in metallurgy and industrial chemical applications requires a fast, easy and cheap method for the determination of metallic iron, not merely in recyclable materials, such as iron pellets, reduced iron mill scale dust, electric arc furnace dust and pig iron, but from hot briquette iron (HBI as well. This study investigates a new method for determination of metallic iron within HBI used for steel-making materials. The effects of reaction time, temperature, and stirring rate were studied. The concentration of iron was determined via Atomic Absorption Spectroscopy (AAS. After the optimization study, high-purity metallic iron powder (Sigma-Aldrich, PubChem Substance ID 24855469 was used to compare efficiencies and identify the optimum conditions; The present study was matched with international standard methods (BS ISO 5416:2006, IS 15774:2007. Results were consistent with certified values and metallic iron content could be determined within the 95% confidence level. The purposed method is easy, straightforward, and cheap.
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Lindegaard, Casper; Vaabengaard, Dorte; Christophersen, Mogens T; Ekstøm, Claus T; Fjeldborg, Julie
2009-07-01
To compare effects of hot iron branding and microchip transponder injection regarding aversive behavioral reactions indicative of pain and inflammation in horses. 7 adult horses. In a randomized controlled clinical crossover study, behavioral reactions to hot iron branding and microchip transponder injection were scored by 4 observers. Local and systemic inflammation including allodynia were assessed and compared by use of physiologic and biochemical responses obtained repeatedly for the 168-hour study period. Serum cortisol concentration was measured repeatedly throughout the first 24 hours of the study. Sham treatments were performed 1 day before and 7 days after treatments. Hot iron branding elicited a significantly stronger aversive reaction indicative of pain than did microchip transponder injection (odds ratio [OR], 12.83). Allodynia quantified by means of skin sensitivity to von Frey monofilaments was significantly greater after hot iron branding than after microchip transponder injection (OR, 2.59). Neither treatment induced signs of spontaneously occurring pain that were observed during the remaining study period, and neither treatment induced increased serum cortisol concentrations. Comparison with sham treatments indicated no memory of an unpleasant event. The hot iron branding areas had significantly increased skin temperature and swelling (OR, 14.6). Systemic inflammation as measured via serum amyloid A concentration was not detected after any of the treatments. Microchip transponder injection induced less signs of pain and inflammation and did not seem to pose a higher long-term risk than hot iron branding. Consequently, results indicated that hot iron branding does inflict more pain and should be abandoned where possible.
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Fundamental study on carbon composite iron ore hot briquette used as blast furnace burden
Energy Technology Data Exchange (ETDEWEB)
Chu, Man-sheng; Liu, Zheng-gen; Wang, Zhao-cai [Institute of Ferrous Metallurgy, Northeastern University, Shenyang (China); Yagi, Jun-ichiro [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University (Japan)
2011-05-15
Carbon composite iron ore hot briquette (CCB) is the product of fine iron ore and fine coal by hot briquetting process, which attracts more and more attention as a new type of ironmaking raw materials aiming to improve the operation efficiency and reduce the coke consumption of blast furnace. This paper is devoted to experimental study on metallurgical properties of CCB and numerical simulation of the BF operation with CCB charging. At first, the metallurgical properties of CCB, including cold crushing strength, RDI, RSI, reducibility, high temperature strength, and softening and dripping are experimentally tested and compared with the common burdens, which revealed that the CCB possesses the required metallurgical properties and is suitable to use as the blast furnace burden. Then, the effects of charging CCB on the dripping properties of comprehensive burdens are elucidated based on the experiments under simulated blast furnace conditions. The results showed that the maximum charging ratio of CCB in the iron burdens is 40%-50% for achieving appropriate dripping properties of the mixed burdens. Finally, a multi-fluid blast furnace model is used to simulate BF operation with CCB charging. According to model simulations, charging CCB will cause the temperature level to decreases in the furnace and the location of the cohesive zone shifts downward. On the other hand, the productivity tends to increase while coke rate and total reducing agent rate decrease, the heat efficiency improves remarkably and the operation performance of BF is effectively enhanced. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)
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Iron Homeostasis in Yellowstone National Park Hot Spring Microbial Communities
Brown, I.; Tringe, S. G.; Franklin, H.; Bryant, D. A.; Klatt, C. G.; Sarkisova, S. A.; Guevara, M.
2010-01-01
It has been postulated that life may have originated on Earth, and possibly on Mars, in association with hydrothermal activity and high concentrations of ferrous iron. However, it is not clear how an iron-rich thermal hydrosphere could be hospitable to microbes, since reduced iron appears to stimulate oxidative stress in all domains of life and particularly in oxygenic phototrophs. Therefore, the study of microbial diversity in iron-depositing hot springs (IDHS) and the mechanisms of iron homeostasis and suppression of oxidative stress may help elucidate how Precambrian organisms could withstand the extremely high concentrations of reactive oxygen species (ROS) produced by interaction between environmental Fe(2+) and O2. Proteins and clusters of orthologous groups (COGs) involved in the maintenance of Fe homeostasis found in cyanobacteria (CB) inhabiting environments with high and low [Fe] were main target of this analysis. Preliminary results of the analysis suggest that the Chocolate Pots (CP) microbial community is heavily dominated by phototrophs from the cyanobacteria (CB), Chloroflexi and Chlorobi phyla, while the Mushroom Spring (MS) effluent channel harbors a more diverse community in which Chloroflexi are the dominant phototrophs. It is speculated that CB inhabiting IDHS have an increased tolerance to both high concentrations of Fe(2+) and ROS produced in the Fenton reaction. This hypothesis was explored via a comparative analysis of the diversity of proteins and COGs involved in Fe and redox homeostasis in the CP and MS microbiomes.
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Regeneration of iron oxide containing pellets used for hot gas clean up
Energy Technology Data Exchange (ETDEWEB)
Palmer, A.; Heeney, P.; Furimsky, E. (CANMET, Ottawa, Ontario (Canada). Energy Research Laboratories)
1989-09-01
Four iron-containing pelletized solids used for H{sub 2}S removal from hot gas were oxidized in a Cahn electrobalance and in a fixed bed reactor. The main reactions included the sequence in which FeS was oxidized to iron sulphate which then decomposed rapidly yielding SO{sub 2} and iron oxides. The oxidation occurred predominantly on the outer surface of the pellets. 12 refs., 5 figs., 5 tabs.
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Prediction of reducible soil iron content from iron extraction data
Bodegom, van P.M.; Reeven, van J.; Denier van der Gon, H.A.C.
2003-01-01
Soils contain various iron compounds that differ in solubility, reducibility and extractability. Moreover, the contribution of the various iron compounds to total iron (Fe) and total Fe concentrations differs highly among soils. As a result, the total reducible Fe content can also differ among
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Distinguishing iron-reducing from sulfate-reducing conditions
Chapelle, F.H.; Bradley, P.M.; Thomas, M.A.; McMahon, P.B.
2009-01-01
Ground water systems dominated by iron- or sulfate-reducing conditions may be distinguished by observing concentrations of dissolved iron (Fe2+) and sulfide (sum of H2S, HS-, and S= species and denoted here as "H2S"). This approach is based on the observation that concentrations of Fe2+ and H2S in ground water systems tend to be inversely related according to a hyperbolic function. That is, when Fe2+ concentrations are high, H2S concentrations tend to be low and vice versa. This relation partly reflects the rapid reaction kinetics of Fe2+ with H2S to produce relatively insoluble ferrous sulfides (FeS). This relation also reflects competition for organic substrates between the iron- and the sulfate-reducing microorganisms that catalyze the production of Fe2+ and H 2S. These solubility and microbial constraints operate in tandem, resulting in the observed hyperbolic relation between Fe2+ and H 2S concentrations. Concentrations of redox indicators, including dissolved hydrogen (H2) measured in a shallow aquifer in Hanahan, South Carolina, suggest that if the Fe2+/H2S mass ratio (units of mg/L) exceeded 10, the screened interval being tapped was consistently iron reducing (H2 ???0.2 to 0.8 nM). Conversely, if the Fe 2+/H2S ratio was less than 0.30, consistent sulfate-reducing (H2 ???1 to 5 nM) conditions were observed over time. Concomitantly high Fe2+ and H2S concentrations were associated with H2 concentrations that varied between 0.2 and 5.0 nM over time, suggesting mixing of water from adjacent iron- and sulfate-reducing zones or concomitant iron and sulfate reduction under nonelectron donor-limited conditions. These observations suggest that Fe2+/H2S mass ratios may provide useful information concerning the occurrence and distribution of iron and sulfate reduction in ground water systems. ?? 2009 National Ground Water Association.
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Sarkisova, S. A.; Tringe, S. G.; Thomas-Keprta, K. L.; Allen, C. c.; Garrison, D. H.; McKay, David S.; Brown, I. I.
2010-01-01
We speculate that both external and intracellular iron precipitate in iron-tolerant CB might be involved in oxidative stress suppression shown by [9]. Significant differences are apparent between a set of proteins involved in the maintenance of Fe homeostasis and oxidative stress protection in iron-tolerant and fresh-water and marine CB. Correspondingly, these properties may help to make iron-tolerant CB as dominant organisms in IDHS and probably on early Earth and Mars. Further comparative analyses of hot springs metagenomes and the genomes of iron-tolerant microbes versus fresh-water/marine ones may point out to different habitable zones on early Mars.
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Cast iron as structural material for hot-working reactor vessels (PCIV)
International Nuclear Information System (INIS)
Ostendorf, H.; Schmidt, G.; Pittack, W.
1977-01-01
Cast iron with lamellar graphite is best suited for prestressed structures, because its compressive strength is nearly 4 times its tensile strength. In comparison to room temperature, cast iron with lamellar graphite shows essentially no loss of strength up to temperatures of 400 0 C. Under the particular aspect to use cast iron for hot-working prestressed reactor pressure vessels (PCIV) (Prestressed cast iron vessel=PCIV) a materials testing program is carried out, which meets the strict certification requirements for materials in the construction of reactor pressure vessels and which completes the presently available knowledge of cast iron. Especially in the following fields an extension and supplement of the present level of knowledge is necessary. - Mechanical properties under compressive stresses. - Material properties at elevated temperatures. - Influence of irradiation on mechanical and physical properties. - Production standards and quality control. The state of the research and the available data of the material testing program are reported. (Auth.)
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Cast iron as structural material for hot-working reactor vessels (PCIV)
International Nuclear Information System (INIS)
Ostendorf, H.; Schmidt, G.; Pittack, W.
1977-01-01
Cast iron with lamellar graphite is best suited for prestressed structures, because its compressive strength is nearly 4 times its tensile strength. In comparison to room temperature, cast iron with lamellar graphite shows essentially no loss of strength up to temperatures of 400 0 C. Under the particular aspect to use cast iron for hot-working prestressed reactor pressure vessels (PCIV) (Prestressed cast iron vessel=PCIV) a materials testing program is carried out, which meets the strict certification requirements for materials in the construction of reactor pressure vessels and which completes the presently available knowledge of cast iron. Especially in the following fields an extension and supplement of the present level of knowledge is necessary: mechanical properties under compressive stresses; material properties at elevated temperatures; influence of irradiation on mechanical and physical properties; production standards and quality control. The state of the research and the available data of the material testing program are reported
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Campe, Amely; Schulz, Sophia; Bohnet, Willa
2016-01-01
Although equids have had to be tagged with a transponder since 2009, breeding associations in Germany disagree as to which method is best suited for identification (with or without hot iron branding). Therefore, the aim of this systematic literature review was to gain an overview of how effective identification is using transponders and hot iron branding and as to which factors influence the success of identification. Existing literature showed that equids can be identified by means of transponders with a probability of 85-100%, whereas symbol brandings could be identified correctly in 78-89%, whole number brandings in 0-87% and single figures in 37-92% of the readings, respectively. The successful reading of microchips can be further optimised by a correctly operated implantation process and thorough training of the applying persons. affect identification with a scanner. The removal of transponders for manipulation purposes is virtually impossible. Influences during the application of branding marks can hardly, if at all, be standardised, but influence the subsequent readability relevantly. Therefore, identification by means of hot branding cannot be considered sufficiently reliable. Impaired quality of identification can be reduced during reading but cannot be counteracted. Based on the existing studies it can be concluded that the transponder method is the best suited of the investigated methods for clearly identifying equids, being forgery-proof and permanent. It is not to be expected that applying hot branding in addition to microchips would optimise the probability of identification relevantly.
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International Nuclear Information System (INIS)
Trajno, A.I.; Yusupov, V.S.; Kugushin, A.A.
1999-01-01
The possibility of plastic deformation of high strength modular cast iron (HSNCI) is under study. The microstructure and mechanical properties of hot worked and heat treated cast iron are investigated for the composition, %: Fe - 2.9 C - 2.4 Si - 0.7 Ni - 0.05 Mg - 0.04 Ce. It is stated that HSNCI can withstand various types of hot working without fracturing. Graphite inclusions lose their modular shape irreversibly during plastic deformation. Subsequent heat treatment affects the metal matrix only. The heating in oxidizing environment is noted to result in cast iron surface decarbonization [ru
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Effect of a cooling gel on pain sensitivity and healing of hot-iron cattle brands.
Tucker, C B; Mintline, E M; Banuelos, J; Walker, K A; Hoar, B; Drake, D; Weary, D M
2014-12-01
Hot-iron branding is painful for cattle, but little is known about how long this pain lasts or effective alleviation methods. Previous work with pigs indicated that cooling burns with a gel (active ingredient: tea tree oil) improved healing compared to untreated wounds. Steers (210±21 kg) were hot-iron branded and allocated to 1 of 3 treatments: control (n=24), 1 gel application immediately after branding (1X; n=12), or 2 gel applications, 1 immediately after branding and one 1 d later (2X; n=12). Pain sensitivity was assessed by applying a known and increasing force with a von Frey anesthesiometer in 5 locations (in the center, at the top of, and 5 and 10 cm above the brand and on the equivalent location on the nonbranded side of the body) until animals showed a behavioral response. Healing was measured with a 6-point scale (1=fresh brand and 6=no scabbing and fully repigmented). Both measures, along with weight gain and surface temperature of the wound, were recorded before and 1, 2, 3, 7, 14, 21, 28, 35, 56, and 70 d after branding. The gel cooled the brand, with the most obvious differences on the day it was applied (3.7 to 4.2°C cooler than control; day×gel interaction, P=0.004). All wounds were at least partially repigmented by 70 d, but only 46% of brands were fully healed at this time. The healing process was slowed when a gel was applied twice (e.g., at 21 d, healing score of 2.5±0.1 and 2.7±0.1 vs. 2.0±0.2 for control and 1X vs. 2X, respectively; P=0.001). Brands tended to remain painful throughout the 70 d (in the center of the brand; before vs. d 1-35, P≤0.001; d 56, P=0.058; and d 70, P=0.092). Overall, gel had little effect on pain sensitivity. Weight gain was reduced on d 1 after branding compared to all other time points (Pbranding. In addition, by 70 d after the procedure, hot-iron brands still tended to be more painful than nonbranded tissue and 54% were not fully healed. These results raise additional animal welfare concerns about hot-iron
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Cyclic Oxidation and Hot Corrosion Behavior of Nickel-Iron-Based Superalloy
Chellaganesh, D.; Adam Khan, M.; Winowlin Jappes, J. T.; Sathiyanarayanan, S.
2018-01-01
The high temperature oxidation and hot corrosion behavior of nickel-iron-based superalloy are studied at 900 ° and 1000 °C. The significant role of alloying elements with respect to the exposed medium is studied in detail. The mass change per unit area was catastrophic for the samples exposed at 1000 °C and gradual increase in mass change was observed at 900 °C for both the environments. The exposed samples were further investigated with SEM, EDS and XRD analysis to study the metallurgical characteristics. The surface morphology has expressed the in situ nature of the alloy and its affinity toward the environment. The EDS and XRD analysis has evidently proved the presence of protective oxides formation on prolonged exposure at elevated temperature. The predominant oxide formed during the exposure at high temperature has a major contribution toward the protection of the samples. The nickel-iron-based superalloy is less prone to oxidation and hot corrosion when compared to the existing alloy in gas turbine engine simulating marine environment.
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Hot iron rods branding, its complications: Still continue in central India
Directory of Open Access Journals (Sweden)
Seema Mahant
2017-01-01
Full Text Available Introduction: The middle of the 20th century has often been described as a golden age of scientific advancement and miraculous medical breakthroughs. In spite of a lot of awareness and many health education programs, still some traditional treatment exists in many places in our country including Central India. In some villages of Madhya Pradesh, many horrifying therapies such as iron rods branding are well known for a few common diseases such as ascites, headache, pneumonia, common cold, or hernia. Bruise marks can be seen on the bodies of a majority of villagers. Main reasons behind such therapy are lack of money for medical treatment, lack of medical facilities, and the unwillingness of medical officers to stay in small villages. Besides this, illiteracy compels them to follow old customs and practices. All these strengthen the faith of villagers in such treatments. It is all due to lack of education and proper awareness. Many female patients come to hospital with complications of iron rods branding suggest that despite being educated, strong cultural beliefs forces people to undergo branding as a treatment of many common diseases in India even in the 21st century. Aims and Objectives: To study the reasons and complications of hot iron branding. Materials and Methods: Sample size was 30. Thirty patients with old, healed (within 1 year, or recent scars of iron branding were included in the study. Patients were evaluated for the sociodemographic details and the information of underlying disease, pattern of lesions, and complications of branding. Results: Hot iron branding is still carrying on as traditional treatment in Central India. It is commonly seen in females of age 20–50 years. It is mostly found in illiterate patients of low socioeconomic status who have chronic disease and chronic pain. Conclusion: Skin branding which still has therapeutic uses in some cultural societies have severe medical complications in Central India.
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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
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Study of Ascorbic Acid as Iron(III Reducing Agent for Spectrophotometric Iron Speciation
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Antesar Elmagirbi
2012-10-01
Full Text Available The study of ascorbic acid as a reducing agent for iron(III has been investigated in order to obtain an alternative carcinogenic reducing agent, hydroxylamine, used in spectrophotometric standard method based on the formation of a red-orange complex of Fe(II-o-phenanthroline. The study was optimised with regards to ascorbic acid concentration as well as pH solution. The results showed that ascorbic acid showed maximum capacity as reducing agent of iron(III under concentration of 4.46.10-4 M and pH solution of 1-4.Under these conditions, ascorbic acid reduced iron(III proportionally and performed similarly to that of hydroxylamine. The method gave result to linear calibration over the range of 0.2-2 mg/L withhigh accuracy of 97 % and relative standard deviation of less than 2 %. This method was successfully applied to assay iron speciation in water samples.
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Hepcidin Protects Neuron from Hemin-Mediated Injury by Reducing Iron
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Yu-Fu Zhou
2017-05-01
Full Text Available Hemin plays a key role in mediating secondary neuronal injury after intracerebral hemorrhage (ICH and the cell toxicity of hemin is thought to be due to iron that is liberated when hemin is degraded. In a recent study, we demonstrated the iron regulatory hormone hepcidin reduces brain iron in iron-overloaded rats. Therefore, we hypothesized that hepcidin might be able to reduce iron and then protect neurons from hemin or iron-mediated neurotoxicity in hemin-treated neuronal cells. Here, we tested the hypothesis and demonstrated that ad-hepcidin and hepcidin peptide both have the ability to suppress the hemin-induced increase in LDH release and apoptotic cell numbers, to reduce cell iron and ferritin contents, and to inhibit expression of transferrin receptor 1, divalent metal transporter 1, and ferroportin 1 in hemin-treated neurons. We conclude that hepcidin protects neuron from hemin-mediated injury by reducing iron via inhibition of expression of iron transport proteins.
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Directory of Open Access Journals (Sweden)
Kopyciński D.
2016-03-01
Full Text Available The paper presents the results of investigations of the growth of protective coating on the surface of ductile iron casting during the hot-dip galvanizing treatment. Ductile iron of the EN-GJS-600-3 grade was melted and two moulds made by different technologies were poured to obtain castings with different surface roughness parameters. After the determination of surface roughness, the hot-dip galvanizing treatment was carried out. Based on the results of investigations, the effect of casting surface roughness on the kinetics of the zinc coating growth was evaluated. It was found that surface roughness exerts an important effect on the thickness of produced zinc coating.
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Mercury methylation coupled to iron reduction by dissimilatory iron-reducing bacteria.
Si, Youbin; Zou, Yan; Liu, Xiaohong; Si, Xiongyuan; Mao, Jingdong
2015-03-01
Iron reduction and mercury methylation by dissimilatory iron-reducing bacteria (DIRB), Geobacter sulfurreducens and Shewanella oneidensis, were studied, and the relationship of mercury methylation coupled to iron reduction was determined. The ability of both bacteria for reducing iron was tested, and Fe(III) reduction occurred with the highest rate when ferric oxyhydroxide was used as a terminal electron acceptor. G. sulfurreducens had proven to mediate the production of methylmercury (MeHg), and a notable increase of MeHg following the addition of inorganic Hg was observed. When the initial concentration of HgCl2 was 500nM, about 177.03nM of MeHg was determined at 8d after G. sulfurreducens inoculation. S. oneidensis was tested negligible for Hg methylation and only 12.06nM of MeHg was determined. Iron reduction could potentially influence Hg methylation rates. The increase in MeHg was consistent with high rate of iron reduction, indicating that Fe(III) reduction stimulated the formation of MeHg. Furthermore, the net MeHg concentration increased at low Fe(III) additions from 1.78 to 3.57mM, and then decreased when the added Fe(III) was high from 7.14 to 17.85mM. The mercury methylation rate was suppressed with high Fe(III) additions, which might have been attributable to mercury complexation and low availability. Copyright © 2014 Elsevier Ltd. All rights reserved.
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International Nuclear Information System (INIS)
Li, F.B.; Li, X.M.; Zhou, S.G.; Zhuang, L.; Cao, F.; Huang, D.Y.; Xu, W.; Liu, T.X.; Feng, C.H.
2010-01-01
The transformation of DDT was studied in an anaerobic system of dissimilatory iron-reducing bacteria (Shewanella decolorationis S12) and iron oxide (α-FeOOH). The results showed that S. decolorationis could reduce DDT into DDD, and DDT transformation rate was accelerated by the presence of α-FeOOH. DDD was observed as the primary transformation product, which was demonstrated to be transformed in the abiotic system of Fe 2+ + α-FeOOH and the system of DIRB + α-FeOOH. The intermediates of DDMS and DBP were detected after 9 months, likely suggesting that reductive dechlorination was the main dechlorination pathway of DDT in the iron-reducing system. The enhanced reductive dechlorination of DDT was mainly due to biogenic Fe(II) sorbed on the surface of α-FeOOH, which can serve as a mediator for the transformation of DDT. This study demonstrated the important role of DIRB and iron oxide on DDT and DDD transformation under anaerobic iron-reducing environments. - This is the first case reporting the reductive dechlorination of DDT in an anaerobic system of dissimilatory iron-reducing bacteria and iron oxide.
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Energy Technology Data Exchange (ETDEWEB)
Li, F.B., E-mail: cefbli@soil.gd.c [Guangdong Key Laboratory of Agricultural Environment Pollution Integrated Control, Guangdong Institute of Eco-Environmental and Soil Sciences, Guangzhou 510650 (China); Li, X.M. [Guangdong Key Laboratory of Agricultural Environment Pollution Integrated Control, Guangdong Institute of Eco-Environmental and Soil Sciences, Guangzhou 510650 (China); Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Graduate School of Chinese Academy of Sciences, Beijing 100039 (China); Zhou, S.G.; Zhuang, L. [Guangdong Key Laboratory of Agricultural Environment Pollution Integrated Control, Guangdong Institute of Eco-Environmental and Soil Sciences, Guangzhou 510650 (China); Cao, F. [Guangdong Key Laboratory of Agricultural Environment Pollution Integrated Control, Guangdong Institute of Eco-Environmental and Soil Sciences, Guangzhou 510650 (China); Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Graduate School of Chinese Academy of Sciences, Beijing 100039 (China); Huang, D.Y.; Xu, W.; Liu, T.X. [Guangdong Key Laboratory of Agricultural Environment Pollution Integrated Control, Guangdong Institute of Eco-Environmental and Soil Sciences, Guangzhou 510650 (China); Feng, C.H. [School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou 510641 (China)
2010-05-15
The transformation of DDT was studied in an anaerobic system of dissimilatory iron-reducing bacteria (Shewanella decolorationis S12) and iron oxide (alpha-FeOOH). The results showed that S. decolorationis could reduce DDT into DDD, and DDT transformation rate was accelerated by the presence of alpha-FeOOH. DDD was observed as the primary transformation product, which was demonstrated to be transformed in the abiotic system of Fe{sup 2+} + alpha-FeOOH and the system of DIRB + alpha-FeOOH. The intermediates of DDMS and DBP were detected after 9 months, likely suggesting that reductive dechlorination was the main dechlorination pathway of DDT in the iron-reducing system. The enhanced reductive dechlorination of DDT was mainly due to biogenic Fe(II) sorbed on the surface of alpha-FeOOH, which can serve as a mediator for the transformation of DDT. This study demonstrated the important role of DIRB and iron oxide on DDT and DDD transformation under anaerobic iron-reducing environments. - This is the first case reporting the reductive dechlorination of DDT in an anaerobic system of dissimilatory iron-reducing bacteria and iron oxide.
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Hot iron branding--not a reasonable requirement for international trade in live ruminants.
Whiting, Terry L.
2005-01-01
"Brand" means a permanent identification mark of which the letters, numbers and figures used are each three (3) inches or more in length or diameter and are humanely burned into the hide of a live animal with a hot iron or tattoo or caustic chemical substance and is to be considered in relation to its location on the animal and the term relates to both the mark and location. PMID:16363334
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Viable cold-tolerant iron-reducing microorganisms in geographically diverse subglacial environments
Nixon, Sophie L.; Telling, Jon P.; Wadham, Jemma L.; Cockell, Charles S.
2017-03-01
Subglacial environments are known to harbour metabolically diverse microbial communities. These microbial communities drive chemical weathering of underlying bedrock and influence the geochemistry of glacial meltwater. Despite its importance in weathering reactions, the microbial cycling of iron in subglacial environments, in particular the role of microbial iron reduction, is poorly understood. In this study we address the prevalence of viable iron-reducing microorganisms in subglacial sediments from five geographically isolated glaciers. Iron-reducing enrichment cultures were established with sediment from beneath Engabreen (Norway), Finsterwalderbreen (Svalbard), Leverett and Russell glaciers (Greenland), and Lower Wright Glacier (Antarctica). Rates of iron reduction were higher at 4 °C compared with 15 °C in all but one duplicated second-generation enrichment culture, indicative of cold-tolerant and perhaps cold-adapted iron reducers. Analysis of bacterial 16S rRNA genes indicates Desulfosporosinus were the dominant iron-reducing microorganisms in low-temperature Engabreen, Finsterwalderbreen and Lower Wright Glacier enrichments, and Geobacter dominated in Russell and Leverett enrichments. Results from this study suggest microbial iron reduction is widespread in subglacial environments and may have important implications for global biogeochemical iron cycling and export to marine ecosystems.
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COMPUTER MODELING OF STRAINS ON PHASE BOUNDARIES IN DUCTILE CAST IRON AT HOT EXTRUSION
Directory of Open Access Journals (Sweden)
A. I. Pokrovsky
2017-01-01
Full Text Available The computer modeling of the strain distribution in the structure of ductile iron with ferrite-pearlite matrix and inclusions of spherical graphite dependence on increasing degree of deformation during direct hot extrusion was researched. Using a software system of finite-element analysis ANSYS the numerical values of the strains at the phase boundaries: ferrite-perlite, graphiteferrite and also inside the graphite inclusions were defined. The analysis of the strain distribution in the investigated structures was performed and local zones of increased strains were discovered. The results of modeling are compared with metallographic analysis and fracture patterns. The obtained results could be used in the prediction of fracture zones in the cast iron products.
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Amyloid fibril systems reduce, stabilize and deliver bioavailable nanosized iron
Shen, Yi; Posavec, Lidija; Bolisetty, Sreenath; Hilty, Florentine M.; Nyström, Gustav; Kohlbrecher, Joachim; Hilbe, Monika; Rossi, Antonella; Baumgartner, Jeannine; Zimmermann, Michael B.; Mezzenga, Raffaele
2017-07-01
Iron-deficiency anaemia (IDA) is a major global public health problem. A sustainable and cost-effective strategy to reduce IDA is iron fortification of foods, but the most bioavailable fortificants cause adverse organoleptic changes in foods. Iron nanoparticles are a promising solution in food matrices, although their tendency to oxidize and rapidly aggregate in solution severely limits their use in fortification. Amyloid fibrils are protein aggregates initially known for their association with neurodegenerative disorders, but recently described in the context of biological functions in living organisms and emerging as unique biomaterial building blocks. Here, we show an original application for these protein fibrils as efficient carriers for iron fortification. We use biodegradable amyloid fibrils from β-lactoglobulin, an inexpensive milk protein with natural reducing effects, as anti-oxidizing nanocarriers and colloidal stabilizers for iron nanoparticles. The resulting hybrid material forms a stable protein-iron colloidal dispersion that undergoes rapid dissolution and releases iron ions during acidic and enzymatic in vitro digestion. Importantly, this hybrid shows high in vivo iron bioavailability, equivalent to ferrous sulfate in haemoglobin-repletion and stable-isotope studies in rats, but with reduced organoleptic changes in foods. Feeding the rats with these hybrid materials did not result in abnormal iron accumulation in any organs, or changes in whole blood glutathione concentrations, inferring their primary safety. Therefore, these iron-amyloid fibril hybrids emerge as novel, highly effective delivery systems for iron in both solid and liquid matrices.
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Effect of phosphorus on hot ductility of high purity iron
International Nuclear Information System (INIS)
Abiko, K.; Liu, C.M.; Ichikawa, M..; Suenaga, H.; Tanino, M.
1995-01-01
Tensile tests on high purity Fe-P alloys with 0, 0.05 and 0.1 mass%P were carried out at temperatures between 300 K and 1073 K to clarify the intrinsic effect of phosphorus on the mechanical properties of iron at elevated temperatures. Microstructures of as-quenched, interrupted and ruptured specimens were observed. Experimental results show that the addition of phosphorus causes a remarkable increase in proof stress of high purity iron at 300 K, but the increase in proof stress by phosphorus decreases with increasing test temperature. The strengthening effect of phosphorus reduces to zero at 1073 K. High purity iron and Fe-P alloys rupture at almost 100% reduction in area at the whole test temperatures. However, Fe-P alloys show much larger elongation at test temperatures above 773 K than high purity iron. The increased elongation of high purity iron by addition of phosphorus was shown to be related to the effect of phosphorus on dynamic recovery and recrystallization of iron as its intrinsic effect. (orig.)
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Zimmermann, M.B.; Zeder, C.; Muthayya, S.; Winichagoon, P.; Chaouki, N.; Aeberli, I.; Hurrell, R.F.
2008-01-01
Background: Overweight is increasing in transition countries, while iron deficiency remains common. In industrialized countries, greater adiposity increases risk of iron deficiency. Higher hepcidin levels in obesity may reduce dietary iron absorption. Therefore, we investigated the association
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Production and Early Preservation of Lipid Biomarkers in Iron Hot Springs
Energy Technology Data Exchange (ETDEWEB)
Parenteau, Mary N.; Jahnke, Linda L.; Farmer, Jack D.; Cady, Sherry L.
2014-06-01
The bicarbonate-buffered anoxic vent waters at Chocolate Pots hot springs in Yellowstone National Park are 51–54°C, pH 5.5–6.0, and are very high in dissolved Fe(II) at 5.8–5.9 mg/L. The aqueous Fe(II) is oxidized by a combination of biotic and abiotic mechanisms and precipitated as primary siliceous nanophase iron oxyhydroxides (ferrihydrite). Four distinct prokaryotic photosynthetic microbial mat types grow on top of these iron deposits. Lipids were used to characterize the community composition of the microbial mats, link source organisms to geologically significant biomarkers, and investigate how iron mineralization degrades the lipid signature of the community. The phospholipid and glycolipid fatty acid profiles of the highest-temperature mats indicate that they are dominated by cyanobacteria and green nonsulfur filamentous anoxygenic phototrophs (FAPs). Diagnostic lipid biomarkers of the cyanobacteria include midchain branched mono- and dimethylalkanes and, most notably, 2-methylbacteriohopanepolyol. Diagnostic lipid biomarkers of the FAPs (Chloroflexus and Roseiflexus spp.) include wax esters and a long-chain tri-unsaturated alkene. Surprisingly, the lipid biomarkers resisted the earliest stages of microbial degradation and diagenesis to survive in the iron oxides beneath the mats. Understanding the potential of particular sedimentary environments to capture and preserve fossil biosignatures is of vital importance in the selection of the best landing sites for future astrobiological missions to Mars. Finally, this study explores the nature of organic degradation processes in moderately thermal Fe(II)-rich groundwater springs—environmental conditions that have been previously identified as highly relevant for Mars exploration.
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Solubilization of plutonium hydrous oxide by iron-reducing bacteria
International Nuclear Information System (INIS)
Rusin, P.A.; Quintana, L.; Brainard, J.R.; Strietelmeler, B.A.; Tait, C.D.; Ekberg, S.A.; Palmer, P.D.; Newton, T.W.; Clark, D.L.
1994-01-01
The removal of plutonium from soils id challenging because of its strong sorption to soils and limited solubility, Microbial reduction of metals is known to affect the speciation and solubility of sparingly soluble metals in the environment, notably iron and manganese. The similarity in reduction potential for α-FeOOH(s) and hydrous PuO 2 (s) suggests that iron-reducing bacteria may also reduce and solubilize plutonium. Bacillus strains were used to demonstrate that iron-reducing bacteria mediate the solubilization of hydrous PuO 2 (s) under anaerobic conditions. Up to ∼90% of the PuO 2 was biosolubilized in the presence of nitrilotriacetic acid (NTA) within 6-7 days. Biosolubilization occurred to a lesser extent (∼ 40%) in the absence of NTA. Little PuO 2 solubilization occurred in sterile culture media or in the presence of a non-iron-reducing Escherichia coli. These observations suggest a potentially attractive, environmentally benign strategy for the remediation of Pu-contaminated soils. 26 refs., 5 figs., 2 tabs
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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.
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Effect of Some Sudanese Traditional Hot Iron Branding on Cattle Hide Quality
Directory of Open Access Journals (Sweden)
Rehab Eltejani Abdelkarim
2016-12-01
Full Text Available This study was designed in order to assess and evaluate the effect of hot iron branding on cattle hide quality. 62 shapes of hot iron branding were detected and classified. Branding damage was evaluated depending on: purpose of application, location in the animal body, branding area, tribe which applied and hide degree. The results showed that, Baggara tribes branding were causing the greater damage on cattle hides; where 71.4% of its brands placed in the abdominal and animal back area (middle of the hide; in proportion to Misseriya Zuraq tribes (68.4%. According to the location of branding, the less tribe that causing damages to the cattle hides were Darfur tribes (14.3%. In terms of branding area Darfur tribes were causing the most branding damages where 42.8% of its brands on cattle hides were between 20-30cm, followed by Baggara tribes where 57.1% of its brands were between 10-20cm then Misseriya Zuraq tribes by 52.6%, and finally North Kordofan tribes of 37.5%. grading of cattle hides depending on the presence of the brand marks the study revealed that, Misseriya Zuraq tribe's brands were obtained the highest percentage (89.4% of the rejected hides (Scarto= 4 and 5 grades, when compared with North Kordofan tribes (87.5%. For commercial reason brand's were mostly done in the area of 5-10cm but, their effect on cattle hide quality was greater, where 81% of the hides were classified as Scarto.
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IRON-TOLERANT CYANOBACTERIA: IMPLICATIONS FOR ASTROBIOLOGY
Brown, Igor I.; Allen, Carlton C.; Mummey, Daniel L.; Sarkisova, Svetlana A.; McKay, David S.
2006-01-01
The review is dedicated to the new group of extremophiles - iron tolerant cyanobacteria. The authors have analyzed earlier published articles about the ecology of iron tolerant cyanobacteria and their diversity. It was concluded that contemporary iron depositing hot springs might be considered as relative analogs of Precambrian environment. The authors have concluded that the diversity of iron-tolerant cyanobacteria is understudied. The authors also analyzed published data about the physiological peculiarities of iron tolerant cyanobacteria. They made the conclusion that iron tolerant cyanobacteria may oxidize reduced iron through the photosystem of cyanobacteria. The involvement of both Reaction Centers 1 and 2 is also discussed. The conclusion that iron tolerant protocyanobacteria could be involved in banded iron formations generation is also proposed. The possible mechanism of the transition from an oxygenic photosynthesis to an oxygenic one is also discussed. In the final part of the review the authors consider the possible implications of iron tolerant cyanobacteria for astrobiology.
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International Nuclear Information System (INIS)
Alekseev, I.E.
2007-01-01
Influence of nuclear prehistory on transfer velocity of 54 Mn impurity 'hot'-atoms - got by different nuclear channels: 56 Fe(d, α), 54 Fe(n,p) in irradiated metallic iron - is studied. Irradiation of targets were carried out in U-120 accelerator (energy range 7.3/5.3 MeV, deuteron beam current makes up 5 μA). Mean density of thermal neutron (WWR-M reactor) makes up 8.6·10 13 neutron·cm -2 ·s -1 . It is shown, that transfer velocity of 54 Mn 'hot' atoms is defining by rate of radiation damage of targets in the irradiation process at that a key importance has a bombarding particles type applied for radioactive label getting
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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)
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Pain sensitivity and healing of hot-iron cattle brands.
Tucker, C B; Mintline, E M; Banuelos, J; Walker, K A; Hoar, B; Varga, A; Drake, D; Weary, D M
2014-12-01
Hot-iron branding is painful for cattle, but little is known about the duration of or effective methods to control this pain. This work quantified pain sensitivity and healing in branded and unbranded animals. In addition, the effects of a single injection of nonsteroidal anti-inflammatory drug (NSAID) were also considered; this has been suggested as practical method of mitigating pain in the hours after the procedure. Calves (mean±SE, 126±2.2 d and 112±2.8 kg) were hot-iron branded and allocated to 1 of 4 treatments: branded with or without flunixin meglumine (intravenous; 1.1 mg/kg) and unbranded with or without this NSAID (n=12/treatment). Pain sensitivity was assessed by applying a known and increasing force with a von Frey anesthesiometer in the center of the brand (or equivalent area in nonbranded treatments) until animals showed a behavioral response. Healing was measured with a 6-point scale (1=fresh brand and 6=no scabbing and fully repigmented). These measures, along with weight gain and surface temperature, were recorded 1, 2, 7, 14, 21, 28, 35, 42, 56, and 71 d after branding. Lying behavior was recorded with loggers from the day before to d 27 after branding. Brand wounds were more painful than nonbranded tissue (Pbranding (e.g., d 7; 113±36 g of force for Brand vs. 449±23 g force for No brand, mean±SE) but persisted until d 71 (380±37 g force for Brand vs. 453±23 g of force for No brand, mean±SE); only 67% of brands were fully regimented or healed by this time. The first fully healed brand was identified 8 wk after the procedure. Giving a single injection of flunixin had no brand-specific effects on sensitivity, surface temperature, or healing but improved weight gain in the days after branding in all treated groups (flunixin×brand×day, Pbranding but tended to spend more time lying on d 15 and 26 after the procedure. The magnitude of these differences is small, less than the day-to-day variation, and not brand specific. In summary, brand
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Cooking Chicken Breast Reduces Dialyzable Iron Resulting from Digestion of Muscle Proteins
Directory of Open Access Journals (Sweden)
Aditya S. Gokhale
2014-01-01
Full Text Available The purpose of this research was to study the effect of cooking chicken breast on the production of dialyzable iron (an in vitro indicator of bioavailable iron from added ferric iron. Chicken breast muscle was cooked by boiling, baking, sautéing, or deep-frying. Cooked samples were mixed with ferric iron and either extracted with acid or digested with pepsin and pancreatin. Total and ferrous dialyzable iron was measured after extraction or digestion and compared to raw chicken samples. For uncooked samples, dialyzable iron was significantly enhanced after both extraction and digestion. All cooking methods led to markedly reduced levels of dialyzable iron both by extraction and digestion. In most cooked, digested samples dialyzable iron was no greater than the iron-only (no sample control. Cooked samples showed lower levels of histidine and sulfhydryls but protein digestibility was not reduced, except for the sautéed sample. The results showed that, after cooking, little if any dialyzable iron results from digestion of muscle proteins. Our research indicates that, in cooked chicken, residual acid-extractable components are the most important source of dialyzable iron.
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Cooking Chicken Breast Reduces Dialyzable Iron Resulting from Digestion of Muscle Proteins.
Gokhale, Aditya S; Mahoney, Raymond R
2014-01-01
The purpose of this research was to study the effect of cooking chicken breast on the production of dialyzable iron (an in vitro indicator of bioavailable iron) from added ferric iron. Chicken breast muscle was cooked by boiling, baking, sautéing, or deep-frying. Cooked samples were mixed with ferric iron and either extracted with acid or digested with pepsin and pancreatin. Total and ferrous dialyzable iron was measured after extraction or digestion and compared to raw chicken samples. For uncooked samples, dialyzable iron was significantly enhanced after both extraction and digestion. All cooking methods led to markedly reduced levels of dialyzable iron both by extraction and digestion. In most cooked, digested samples dialyzable iron was no greater than the iron-only (no sample) control. Cooked samples showed lower levels of histidine and sulfhydryls but protein digestibility was not reduced, except for the sautéed sample. The results showed that, after cooking, little if any dialyzable iron results from digestion of muscle proteins. Our research indicates that, in cooked chicken, residual acid-extractable components are the most important source of dialyzable iron.
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Stilwell, G; Lima, M S; Carvalho, R C; Broom, D M
2012-04-01
The objective of this study was to assess cortisol and behaviour changes in calves hot-iron disbudded after different analgesic protocols. We assessed the response of 27 calves at 1, 3, 6 and 24 h after disbudding with regional anaesthesia (DA), regional anaesthesia plus carprofen (DAC), disbudded only (D) or sham-disbudded (ND). At 1h cortisol was higher in D compared with all other groups. At 3h DA showed higher cortisol than ND but did not differ from baseline. At 15 min and 1h pain-related behaviours were more frequent in the D group than in all other groups. Group D (3 h) and DA (3 and 6 h) showed more ear flicks and head rubs compared with DAC and ND. We concluded that head rubbing, head shaking and ear flicking are useful behaviours for evaluating pain after hot-iron disbudding. Disbudding causes severe pain in calves and only the association of regional anaesthesia with carprofen assures good welfare for 24 h. Copyright © 2011 Elsevier Ltd. All rights reserved.
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Microbial community analysis of perchlorate-reducing cultures growing on zero-valent iron
International Nuclear Information System (INIS)
Son, Ahjeong; Schmidt, Carl J.; Shin, Hyejin; Cha, Daniel K.
2011-01-01
Anaerobic microbial mixed cultures demonstrated its ability to completely remove perchlorate in the presence of zero-valent iron. In order to understand the major microbial reaction in the iron-supported culture, community analysis comprising of microbial fatty acids and polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) techniques was performed for perchlorate reducing cultures. Analysis of fatty acid methyl esters (FAMEs) and subsequent principal component analysis (PCA) showed clear distinctions not only between iron-supported perchlorate reducing culture and seed bacteria, but also among perchlorate-reducing cultures receiving different electron donors. The DGGE pattern targeting the chlorite dismutase (cld) gene showed that iron-supported perchlorate reducing culture is similar to hydrogen-fed cultures as compared to acetate-fed culture. The phylogenetic tree suggested that the dominant microbial reaction may be a combination of the autotrophic and heterotrophic reduction of perchlorate. Both molecular and chemotaxonomic experimental results support further understanding in the function of zero-valent iron as an adequate electron source for enhancing the microbial perchlorate reduction in natural and engineered systems.
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Microbial community analysis of perchlorate-reducing cultures growing on zero-valent iron
Energy Technology Data Exchange (ETDEWEB)
Son, Ahjeong, E-mail: ason@auburn.edu [Department of Civil Engineering, Auburn University, Auburn, AL 36849 (United States); Schmidt, Carl J. [Department of Animal and Food Sciences, University of Delaware, Newark, DE 19716 (United States); Shin, Hyejin [Department of Mathematics and Statistics, Auburn University, Auburn, AL 36849 (United States); Cha, Daniel K. [Department of Civil and Environmental Engineering, University of Delaware, Newark, DE 19716 (United States)
2011-01-30
Anaerobic microbial mixed cultures demonstrated its ability to completely remove perchlorate in the presence of zero-valent iron. In order to understand the major microbial reaction in the iron-supported culture, community analysis comprising of microbial fatty acids and polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) techniques was performed for perchlorate reducing cultures. Analysis of fatty acid methyl esters (FAMEs) and subsequent principal component analysis (PCA) showed clear distinctions not only between iron-supported perchlorate reducing culture and seed bacteria, but also among perchlorate-reducing cultures receiving different electron donors. The DGGE pattern targeting the chlorite dismutase (cld) gene showed that iron-supported perchlorate reducing culture is similar to hydrogen-fed cultures as compared to acetate-fed culture. The phylogenetic tree suggested that the dominant microbial reaction may be a combination of the autotrophic and heterotrophic reduction of perchlorate. Both molecular and chemotaxonomic experimental results support further understanding in the function of zero-valent iron as an adequate electron source for enhancing the microbial perchlorate reduction in natural and engineered systems.
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Directory of Open Access Journals (Sweden)
Kendera Ján
1997-09-01
Full Text Available Results of the laboratory test treatment of the zinc containing steelwork dusts in a hot liquid pig iron are described. These results show that it is necessary to use an external reductant. The zinc content of the dust emission is ca. 20 %. The charge of the steel-works dusts diminished the Si and Mn content of pig iron.
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Phylogenetic diversity of dissimilatory ferric iron reducers in paddy soil of Hunan, South China
Energy Technology Data Exchange (ETDEWEB)
Wang Xin-Jun [State Key Lab. of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, BJ (China); Graduate Univ., Chinese Academy of Sciences, BJ (China); Yang Jing; Chen Xue-Ping; Sun Guo-Xin [State Key Lab. of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, BJ (China); Zhu Yong-Guan [State Key Lab. of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, BJ (China); Key Lab. of Urban Environment and Health, Inst. of Urban Environment, Chinese Academy of Sciences, Xiamen (China)
2009-12-15
Purpose: Dissimilatory iron-reducing bacteria have been described by both culture-dependent and -independent methods in various environments, including freshwater, marine sediments, natural wetlands, and contaminated aquifers. However, little is known about iron-reducing microbial communities in paddy soils. The goal of this study was to characterize iron-reducing microbial communities in paddy soil. Moreover, the effect of dissolved and solid-phase iron (III) species on the iron-reducing microbial communities was also investigated by enrichment cultures. Methods: Ferric citrate and ferrihydrite were used respectively to set up enrichment cultures of dissimilatory ironreducing microorganisms using 1% inoculum of soil samples, and the iron reduction was measured. Moreover, bacterial DNA was extracted and 16S rRNA genes were PCR-amplified, and subsequently analyzed by the clone library and terminal restriction fragment length polymorphism (T-RFLP). Results: Phylogenetic analysis of 16S rRNA gene sequences extracted from the enrichment cultures revealed that Bradyrhizobium, Bacteroides, Clostridium and Ralstonia species were the dominant bacteria in the ferric citrate enrichment. However, members of the genera Clostridium, Bacteroides, and Geobacter were the dominant micro-organisms in the ferrihydrite enrichment. Analysis of enrichment cultures by T-RFLP strongly supported the cloning and sequencing results. Conclusions: The present study demonstrated that dissimilatory iron-reducing consortia in As-contaminated paddy soil are phylogenetically diverse. Moreover, iron (III) sources as a key factor have a strong effect on the iron (III)-reducing microbial community structure and relative abundance in the enrichments. In addition, Geobacter species are selectively enriched by ferrihydrite enrichment cultures. (orig.)
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Hoyer, D.; Rauch, T.; Werner, K.; Kruk, J. W.
2018-04-01
The metal abundances in the atmospheres of hot white dwarfs (WDs) entering the cooling sequence are determined by the preceding Asymptotic Giant Branch (AGB) evolutionary phase and, subsequently, by the onset of gravitational settling and radiative levitation. In this paper, we investigate three hot He-rich WDs, which are believed to result from a late He-shell flash. During such a flash, the He-rich intershell matter is dredged up and dominates the surface chemistry. Hence, in contrast to the usual H-rich WDs, their spectra allow direct access to s-process element abundances in the intershell that were synthesized during the AGB stage. In order to look for trans-iron group elements (atomic number Z > 29), we performed a non-local thermodynamic equilibrium model atmosphere analysis of new ultraviolet spectra taken with the Cosmic Origins Spectrograph aboard the Hubble Space Telescope. One of our program stars is of PG 1159 spectral type; this star, PG 1707+427, has effective temperature Teff = 85 000 K, and surface gravity logg = 7.5. The two other stars are DO white dwarfs: WD 0111+002 has Teff = 58 000 K and log g = 7.7, and PG 0109+111 has Teff = 70 000 K and log g = 8.0. These stars trace the onset of element diffusion during early WD evolution. While zinc is the only trans-iron element we could detect in the PG 1159 star, both DOs exhibit lines from Zn, Ga, Ge, Se; one additionally exhibits lines from Sr, Sn, Te, and I and the other from As. Generally, the trans-iron elements are very abundant in the DOs, meaning that radiative levitation must be acting. Most extreme is the almost six orders of magnitude oversolar abundance of tellurium in PG 0109+111. In terms of mass fraction, it is the most abundant metal in the atmosphere. The two DOs join the hitherto unique hot DO RE 0503-289, in which 14 trans-iron elements had even been identified. Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which
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Iron release from ferritin and lipid peroxidation by radiolytically generated reducing radicals
International Nuclear Information System (INIS)
Reif, D.W.; Schubert, J.; Aust, S.D.
1988-01-01
Iron is involved in the formation of oxidants capable of damaging membranes, protein, and DNA. Using 137 Cs gamma radiation, we investigated the release of iron from ferritin and concomitant lipid peroxidation by radiolytically generated reducing radicals, superoxide and the carbon dioxide anion radical. Both radicals released iron from ferritin with similar efficiencies and iron mobilization from ferritin required an iron chelator. Radiolytically generated superoxide anion resulted in peroxidation of phospholipid liposomes as measured by malondialdehyde formation only when ferritin was included as an iron source and the released iron was found to be chelated by the phospholipid liposomes
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Discussion of Carbon Emissions for Charging Hot Metal in EAF Steelmaking Process
Yang, Ling-zhi; Jiang, Tao; Li, Guang-hui; Guo, Yu-feng
2017-07-01
As the cost of hot metal is reduced for iron ore prices are falling in the international market, more and more electric arc furnace (EAF) steelmaking enterprises use partial hot metal instead of scrap as raw materials to reduce costs and the power consumption. In this paper, carbon emissions based on 1,000 kg molten steel by charging hot metal in EAF steelmaking is studied. Based on the analysis of material and energy balance calculation in EAF, the results show that 146.9, 142.2, 137.0, and 130.8 kg/t of carbon emissions are produced at a hot metal ratio of 0 %, 30 %, 50 %, and 70 %, while 143.4, 98.5, 65.81, and 31.5 kg/t of carbon emissions are produced at a hot metal ratio of 0 %, 30 %, 50 %, and 70 % by using gas waste heat utilization (coal gas production) for EAF steelmaking unit process. However, carbon emissions are increased by charging hot metal for the whole blast furnace-electric arc furnace (BF-EAF) steelmaking process. In the condition that the hot metal produced by BF is surplus, as carbon monoxide in gas increased by charging hot metal, the way of coal gas production can be used for waste heat utilization, which reduces carbon emissions in EAF steelmaking unit process.
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Energy Technology Data Exchange (ETDEWEB)
Donald R. Fosnacht; Richard F. Kiesel; David W. Hendrickson; David J. Englund; Iwao Iwasaki; Rodney L. Bleifuss; Mathew A. Mlinar
2011-12-22
The current trend in the steel industry is an increase in iron and steel produced in electric arc furnaces (EAF) and a gradual decline in conventional steelmaking from taconite pellets in blast furnaces. In order to expand the opportunities for the existing iron ore mines beyond their blast furnace customer base, a new material is needed to satisfy the market demands of the emerging steel industry while utilizing the existing infrastructure and materials handling capabilities. This demand creates opportunity to convert iron ore or other iron bearing materials to Nodular Reduced Iron (NRI) in a recently designed Linear Hearth Furnace (LHF). NRI is a metallized iron product containing 98.5 to 96.0% iron and 2.5 to 4% C. It is essentially a scrap substitute with little impurity that can be utilized in a variety of steelmaking processes, especially the electric arc furnace. The objective of this project was to focus on reducing the greenhouse gas emissions (GHG) through reducing the energy intensity using specialized combustion systems, increasing production and the use of biomass derived carbon sources in this process. This research examined the use of a solid fuel-oxygen fired combustion system and compared the results from this system with both oxygen-fuel and air-fuel combustion systems. The solid pulverized fuels tested included various coals and a bio-coal produced from woody biomass in a specially constructed pilot scale torrefaction reactor at the Coleraine Minerals Research Laboratory (CMRL). In addition to combustion, the application of bio-coal was also tested as a means to produce a reducing atmosphere during key points in the fusion process, and as a reducing agent for ore conversion to metallic iron to capture the advantage of its inherent reduced carbon footprint. The results from this study indicate that the approaches taken can reduce both greenhouse gas emissions and the associated energy intensity with the Linear Hearth Furnace process for converting
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Iron-Tolerant Cyanobacteria: Ecophysiology and Fingerprinting
Brown, I. I.; Mummey, D.; Lindsey, J.; McKay, D. S.
2006-01-01
Although the iron-dependent physiology of marine and freshwater cyanobacterial strains has been the focus of extensive study, very few studies dedicated to the physiology and diversity of cyanobacteria inhabiting iron-depositing hot springs have been conducted. One of the few studies that have been conducted [B. Pierson, 1999] found that cyanobacterial members of iron depositing bacterial mat communities might increase the rate of iron oxidation in situ and that ferrous iron concentrations up to 1 mM significantly stimulated light dependent consumption of bicarbonate, suggesting a specific role for elevated iron in photosynthesis of cyanobacteria inhabiting iron-depositing hot springs. Our recent studies pertaining to the diversity and physiology of cyanobacteria populating iron-depositing hot springs in Great Yellowstone area (Western USA) indicated a number of different isolates exhibiting elevated tolerance to Fe(3+) (up to 1 mM). Moreover, stimulation of growth was observed with increased Fe(3+) (0.02-0.4 mM). Molecular fingerprinting of unialgal isolates revealed a new cyanobacterial genus and species Chroogloeocystis siderophila, an unicellular cyanobacterium with significant EPS sheath harboring colloidal Fe(3+) from iron enriched media. Our preliminary data suggest that some filamentous species of iron-tolerant cyanobacteria are capable of exocytosis of iron precipitated in cytoplasm. Prior to 2.4 Ga global oceans were likely significantly enriched in soluble iron [Lindsay et al, 2003], conditions which are not conducive to growth of most contemporary oxygenic cyanobacteria. Thus, iron-tolerant CB may have played important physiological and evolutionary roles in Earths history.
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Magnetic characteristics of ultrafine Fe particles reduced from uniform iron oxide particles
Bridger, K.; Watts, J.; Tadros, M.; Xiao, Gang; Liou, S. H.; Chien, C. L.
1987-04-01
Uniform, cubic 0.05-μm iron oxide particles were formed by forced hydrolysis of ferric perchlorate. These particles were reduced to α-Fe by heating in hydrogen at temperatures between 300 and 500 °C. The effect of reduction temperature and various prereduction treatments on the microstructure of the iron particles will be discussed. Complete reduction to α-Fe was established by 57Fe Mössbauer spectroscopy and x-ray diffraction. Magnetic measurements on epoxy and polyurethane films containing these particles with various mass fractions gave coercivities as high as 1000 Oe. The relationship between the magnetic measurements and the microstructure will be discussed. Na2SiO3 is found to be the best coating material for the process of reducing iron oxide particles to iron.
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Ghosh, Dhritiman; Bal, Bijay; Kashyap, V. K.; Pal, Subrata
2003-01-01
The bacterial diversity of a hot spring in Bakreshwar, India, was investigated by a culture-independent approach. 16S ribosomal DNA clones derived from the sediment samples were found to be associated with gamma-Proteobacteria, cyanobacteria, and green nonsulfur and low-GC gram-positive bacteria. The first of the above phylotypes cobranches with Shewanella, a well-known iron reducer. This phylogenetic correlation has been exploited to develop culture conditions for thermophilic iron-reducing microorganisms. PMID:12839826
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Zhao, Gengli; Xu, Guobin; Zhou, Min; Jiang, Yaping; Richards, Blair; Clark, Katy M; Kaciroti, Niko; Georgieff, Michael K; Zhang, Zhixiang; Tardif, Twila; Li, Ming; Lozoff, Betsy
2015-08-01
Previous trials of prenatal iron supplementation had limited measures of maternal or neonatal iron status. The purpose was to assess effects of prenatal iron-folate supplementation on maternal and neonatal iron status. Enrollment occurred June 2009 through December 2011 in Hebei, China. Women with uncomplicated singleton pregnancies at ≤20 wk gestation, aged ≥18 y, and with hemoglobin ≥100 g/L were randomly assigned 1:1 to receive daily iron (300 mg ferrous sulfate) or placebo + 0.40 mg folate from enrollment to birth. Iron status was assessed in maternal venous blood (at enrollment and at or near term) and cord blood. Primary outcomes were as follows: 1) maternal iron deficiency (ID) defined in 2 ways as serum ferritin (SF) iron (BI) anemia [ID + anemia (IDA); hemoglobin 118 μmol/mol). A total of 2371 women were randomly assigned, with outcomes for 1632 women or neonates (809 placebo/folate, 823 iron/folate; 1579 mother-newborn pairs, 37 mothers, 16 neonates). Most infants (97%) were born at term. At or near term, maternal hemoglobin was significantly higher (+5.56 g/L) for iron vs. placebo groups. Anemia risk was reduced (RR: 0.53; 95% CI: 0.43, 0.66), as were risks of ID (RR: 0.74; 95% CI: 0.69, 0.79 by SF; RR: 0.65; 95% CI: 0.59, 0.71 by BI) and IDA (RR: 0.49; 95% CI: 0.38, 0.62 by SF; RR: 0.51; 95% CI: 0.40, 0.65 by BI). Most women still had ID (66.8% by SF, 54.7% by BI). Adverse effects, all minor, were similar by group. There were no differences in cord blood iron measures; >45% of neonates in each group had ID. However, dose-response analyses showed higher cord SF with more maternal iron capsules reported being consumed (β per 10 capsules = 2.60, P iron supplementation reduced anemia, ID, and IDA in pregnant women in rural China, but most women and >45% of neonates had ID, regardless of supplementation. This trial was registered at clinicaltrials.gov as NCT02221752. © 2015 American Society for Nutrition.
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International Nuclear Information System (INIS)
Chistyakova, N. I.; Rusakov, V. S.; Nazarova, K. A.; Koksharov, Yu. A.; Zavarzina, D. G.; Greneche, J.-M.
2008-01-01
Zero-field and in-field Moessbauer investigations and electron paramagnetic resonance (EPR) measurements to follow the kinetics of the iron mineral formation by thermophilic dissimilatory anaerobic Fe(III)-reducing bacteria (strain Z-0001) and anaerobic alkaliphilic bacteria (strain Z-0531) were carried out.
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Plant cell nucleolus as a hot spot for iron.
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.
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The Effect of Ductile Cast Iron Matrix on Zinc Coating During Hot Dip Galvanising of Castings
Directory of Open Access Journals (Sweden)
D. Kopyciński
2012-12-01
Full Text Available The growth kinetics of the zinc coating formed on the surface of casting made from ductile iron grade EN-GJS-500-3 was investigated. To produce homogenous metal matrix in test samples, the normalising and ferritising annealing was carried out. Studies showeda heterogeneous structure of cast iron with varying content of the phases formed. This was followed by hot dip galvanising treatment at450°C to capture the growth kinetics of the zinc coating (the time of the treatment ranged from 60 to 600 seconds. Nonlinear estimation of the determined growth kinetics of the alloyed layer of a zinc coating was made and an equation of the zinc coating growth was derived.Based on the results of the investigations it was concluded that thickness of the zinc coating formed on the surface of casting with a 100% pearlitic matrix makes 55% of the thickness of coating formed on the surface in 100% ferritic.
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The Effect of Ductile Cast Iron Matrix on Zinc Coating During Hot Dip Galvanising of Castings
Directory of Open Access Journals (Sweden)
Kopyciński D.
2012-12-01
Full Text Available The growth kinetics of the zinc coating formed on the surface of casting made from ductile iron grade EN-GJS-500-3 was investigated. To produce homogenous metal matrix in test samples, the normalising and ferritising annealing was carried out. Studies showed a heterogeneous structure of cast iron with varying content of the phases formed. This was followed by hot dip galvanising treatment at 450°C to capture the growth kinetics of the zinc coating (the time of the treatment ranged from 60 to 600 seconds. Nonlinear estimation of the determined growth kinetics of the alloyed layer of a zinc coating was made and an equation of the zinc coating growth was derived. Based on the results of the investigations it was concluded that thickness of the zinc coating formed on the surface of casting with a 100% pearlitic matrix makes 55% of the thickness of coating formed on the surface in 100% ferritic.
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Mossbauer and magnetic study of solid phases formed by dissimilatory iron-reducing bacteria
Czech Academy of Sciences Publication Activity Database
Chistyakova, N.I.; Rusakov, V.S.; Shapkin, A.A.; Pigalev, P.A.; Kazakov, A.P.; Zhilina, T.N.; Zavarzina, D.G.; Lančok, Adriana; Kohout, J.; Greneche, J. M.
2012-01-01
Roč. 190, JUNE (2012), s. 721-724 ISSN 1012-0394 Institutional research plan: CEZ:AV0Z40320502 Keywords : Mossbauer spectroscopy * dissimilatory iron-reducing bacteria * iron oxides * biomagnetism Subject RIV: CA - Inorganic Chemistry
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Energy Technology Data Exchange (ETDEWEB)
Sarangi, B.M.; Kesav, B.; Sheshadri, M.K.
2002-07-01
Direct reduced iron or sponge iron technology was developed as an alternate route for steel making and is considered as a clean technology. The waste generation and gas emissions from this route of steel making are far less when compared to the conventional blast furnace route. The paper details the efforts of Tata Sponge Iron Limited to make the process a clean technology without affecting its surroundings and natural resources. The paper describes the system of bag filters made from filter glass fabric for collecting hot waste gases and for dedusting of product and raw material handling circuits. Design of the plant for waste gas cleaning by scrubbers and by electrostatic precipitators is described. Major pollution control equipment installed at Tata Sponge Iron Ltd., described in the article are: a wet gas cleaning plant (in 1986), a second gas cleaning plant with electrostatic precipitator (in 1998) and dust extraction and dust suppression systems. Water is sprayed around the plant to control fugitive dust and trees have been grown around it. 13 figs.
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System and method for making metallic iron with reduced CO.sub.2 emissions
Kiesel, Richard F; Englund, David J; Schlichting, Mark; Meehan, John; Crouch, Jeremiah; Wilson, Logan
2014-10-14
A method and system for making metallic iron nodules with reduced CO.sub.2 emissions is disclosed. The method includes: assembling a linear hearth furnace having entry and exit portions, at least a conversion zone and a fusion zone, and a moving hearth adapted to move reducible iron bearing material through the furnace on contiguous hearth sections; assembling a shrouded return substantially free of air ingress extending adjacent at least the conversion and fusion zones of the furnace through which hearth sections can move from adjacent the exit portion to adjacent the entry portion of the furnace; transferring the hearth sections from the furnace to the shrouded return adjacent the exit portion; reducing reducible material in the linear hearth furnace to metallic iron nodules; and transporting gases from at least the fusion zone to the shrouded return to heat the hearth sections while in the shrouded return.
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Bailey, Tom G; Cable, N Timothy; Aziz, Nabil; Dobson, Rebecca; Sprung, Victoria S; Low, David A; Jones, Helen
2016-07-01
Postmenopausal hot flushes occur due to a reduction in estrogen production causing thermoregulatory and vascular dysfunction. Exercise training enhances thermoregulatory control of sweating, skin and brain blood flow. We aimed to determine if improving thermoregulatory control and vascular function with exercise training alleviated hot flushes. Twenty-one symptomatic women completed a 7-day hot flush questionnaire and underwent brachial artery flow-mediated dilation and a cardiorespiratory fitness test. Sweat rate and skin blood flow temperature thresholds and sensitivities, and middle cerebral artery velocity (MCAv) were measured during passive heating. Women performed 16 weeks of supervised exercise training or control, and measurements were repeated. There was a greater improvement in cardiorespiratory fitness (4.45 mL/kg/min [95% CI: 1.87, 8.16]; P = 0.04) and reduced hot flush frequency (48 hot flushes/wk [39, 56]; P core temperature (0.14°C [0.01, 0.27]; P = 0.03) and increased basal MCAv (2.8 cm/s [1.0, 5.2]; P = 0.04) compared with control. Sweat rate and skin blood flow thresholds occurred approximately 0.19°C and 0.17°C earlier, alongside improved sweating sensitivity with exercise. MCAv decreased during heating (P training that improves cardiorespiratory fitness reduces self-reported hot flushes. Improvements are likely mediated through greater thermoregulatory control in response to increases in core temperature and enhanced vascular function in the cutaneous and cerebral circulations.
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Directory of Open Access Journals (Sweden)
A. I. Pokrovsky
2016-01-01
Full Text Available Imitation modeling of direct hot extrusion of bushes made from high-strength cast iron is performed using finite-element method. The evolution of stress and strain fields during processing and the probability of crack formation are evaluated. The specific feature of the work is that during hot forming a special technique was used which permitted obtaining a gradient distribution of graphite inclusions over the cross-section of bushes. The results of modeling are used in certain technologies which are implemented in industrial practice.
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International Nuclear Information System (INIS)
Berry, F.J.; Du Hongzhang
1990-01-01
Iron-57 Moessbauer spectroscopy has been used to monitor the reducibility in hydrogen of iron oxides supported on titania of differing surface areas. The results show that although Fe 3+ in the iron oxide supported on low surface area titania (11 m 2 g -1 ) is not amenable to facile reduction at low temperatures, complete reduction to metallic iron is achieved by treatment at 600deg C. The data also show that the extent of reduction at elevated temperatures exceeds that which is obtained on similar silica- and alumina-supported systems. Fe 3+ in iron oxide supported on higher surface area titania (50 m 2 g -1 and 240 m 2 g -1 ) is partially reduced in hydrogen at 235deg C to Fe 2+ but fails to attain complete reduction to the metallic state following treatment at 600deg C. The results are related to the different dispersions of iron oxide which can be attained on titania of differing surface area and the consequent interactions between the support and the supported phases. (orig.)
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Hypnotherapy to Reduce Hot Flashes: Examination of Response Expectancies as a Mediator of Outcomes
Sliwinski, Jim R.; Elkins, Gary R.
2017-01-01
The mechanism of action responsible for hypnotherapy’s effect in reducing hot flashes is not yet known. The purpose of this study was to examine the role of response expectancies as a potential mediator. Hypnotizability was also tested as an effect moderator. Data were collected from a sample of 172 postmenopausal women, who had been randomized to receive either a 5-week hypnosis intervention or structured attention counseling. Measures of response expectancies were analyzed to determine if the relationship between group assignment and hot flashes frequency was mediated by expectancies for treatment efficacy. A series of simple mediation and conditional process analyses did not support mediation of the relationship between treatment condition and hot flash frequency through response expectancy. The effect of hypnotherapy in reducing hot flashes does not appear to be due to placebo effects as determined by response expectancies. Implications for clinical practice and future research are discussed. PMID:28528570
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Energy Technology Data Exchange (ETDEWEB)
Mulac, B.L.; Edwards, G.R. [Colorado School of Mines, Golden, CO (United States). Dept. of Metallurgical and Materials Engineering; David, S.A. [Oak Ridge National Lab., TN (United States)
1998-02-01
Iron aluminides have been of interest for about 60 years because of their good high temperature strengths (below 600{degrees}C) and excellent oxidation and sulfidation resistance, as well as their relatively low cost and conservation of strategic elements. These advantageous properties have driven the development of iron aluminides as potential structural materials. However, the industrial application of iron aluminides has been inhibited because of a sharp reduction in strength at temperatures higher than 600{degrees}C and low ductility at ambient temperatures due to hydrogen embrittlement. Oak Ridge National Laboratory has shown in recent years that room temperature properties of alloys containing 28% Al (all compositions are in atomic percent unless otherwise noted) can be improved through thermomechanical processing and alloying. Iron aluminides must have good weldability if they are to be used as structural materials. A coarse fusion zone microstructure is formed when iron aluminides are welded, increasing their susceptibility to cold cracking in water vapor. A recent study at Colorado School of Mines has shown that refining the fusion zone microstructure by weld pool oscillation effectively reduces cold cracking. Weld pool inoculation has been shown to refine fusion zone microstructures, but coarse carbide distribution caused this approach to reducing cold cracking to be ineffective.
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Hot-rolling metals in vacuum. Information circular
International Nuclear Information System (INIS)
Beall, R.A.; Worthington, R.B.; Blickensderfer, R.
1979-01-01
The process of hot-rolling metals, alloys, and composites in vacuum is studied. First, a comprehensive review of the literature is presented, including the advantages and disadvantages of using vacuum. Next, details of hot-rolling titanium, chromium, and molybdenum-iron bimetal are given. Finally, the design of new equipment is described
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International Nuclear Information System (INIS)
Etique, Marjorie
2014-01-01
Radioactive waste is one of the major problems facing the nuclear industry. To circumvent this issue France plans to store vitrified high-level nuclear waste in a stainless steel container, placed into a non-alloy steel overpack, at a depth of 500 m in an argillaceous formation. The main iron corrosion products formed at the surface of the non-alloy steel are siderite (Fe II CO 3 ) and magnetite (Fe II Fe III 2 O 4 ). These compounds are formed in the anoxic conditions present in the nuclear waste repository and play a protective role against corrosion as a passive layer. This work aims to investigate the activity of nitrate-reducing bacteria (NRB, Klebsiella mobilis) and iron-reducing bacteria (IRB, Shewanella putrefaciens) during the transformation of siderite and magnetite, especially those involved in anoxic iron biogeochemical cycle. Klebsiella mobilis and Shewanella putrefaciens were first incubated with siderite or magnetite suspensions (high surface specific area) in order to exacerbate the microbial iron transformation, subsequently incubated with a magnetite/siderite film synthesized by anodic polarization at applied current density. The transformation of siderite and magnetite by direct or indirect microbial processes led to the formation of carbonated green rust (Fe II 4 Fe III 2 (OH) 12 CO 3 ). As a transient phase shared by several bacterial reactions involving Fe II and Fe III , this compound is the cornerstone of the anoxic iron biogeochemical cycle. The novelty of this thesis is the consideration of bacterial metabolisms of NRB and IRB often overlooked in bio-corrosion processes. (author) [fr
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Porsch, Katharina; Meier, Jutta; Kleinsteuber, Sabine; Wendt-Potthoff, Katrin
2009-05-01
Iron- and sulfate-reducing microorganisms play an important role for alkalinity-generating processes in mining lakes with low pH. In the acidic mining lake 111 in Lusatia, Germany, a passive in situ remediation method was tested in a large scale experiment, in which microbial iron and sulfate reduction are stimulated by addition of Carbokalk (a mixture of the nonsugar compounds of sugar beets and lime) and straw. The treated surface sediment consisted of three layers of different pH and geochemical composition. The top layer was acidic and rich in Fe(III), the second and third layer both showed moderately acidic to circum-neutral pH values, but only the second was rich in organics, strongly reduced and sulfidic. Aim of the study was to elucidate the relative importance of neutrophilic heterotrophic, acidophilic heterotrophic, and acidophilic autotrophic iron-reducing microorganisms in each of the three layers. In order to distinguish between them, the effect of their respective characteristic electron donors acetate, glucose, and elemental sulfur on potential iron reduction rates was investigated. Limitation of iron reduction by the availability of Fe(III) was revealed by the addition of Fe(OH)(3). The three groups of iron-reducing microorganisms were quantified by most probable number (MPN) technique and their community composition was analyzed by cloning and sequencing of 16S rRNA genes. In the acidic surface layer, none of the three electron donors stimulated iron reduction; acetate even had an inhibiting effect. In agreement with this, no decrease of the added electron donors was observed. Iron reduction rates were low in comparison to the other layers. Iron reduction in layers 2 and 3 was enhanced by glucose and acetate, accompanied by a decrease of these electron donors. Addition of elemental sulfur did not enhance iron reduction in either layer. Layer 2 exhibited the highest iron reduction rate (4.08 mmol dm(-3) d(-1)) and the highest cell numbers in MPN
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Effects of titanium and zirconium on iron aluminide weldments
Energy Technology Data Exchange (ETDEWEB)
Mulac, B.L.; Edwards, G.R. [Colorado School of Mines, Golden, CO (United States). Center for Welding, Joining, and Coatings Research; Burt, R.P. [Alumax Technical Center, Golden, CO (United States); David, S.A. [Oak Ridge National Lab., TN (United States). Metals and Ceramics Div.
1997-12-01
When gas-tungsten arc welded, iron aluminides form a coarse fusion zone microstructure which is susceptible to hydrogen embrittlement. Titanium inoculation effectively refined the fusion zone microstructure in iron aluminide weldments, but the inoculated weldments had a reduced fracture strength despite the presence of a finer microstructure. The weldments fractured by transgranular cleavage which nucleated at cracked second phase particles. With titanium inoculation, second phase particles in the fusion zone changed shape and also became more concentrated at the grain boundaries, which increased the particle spacing in the fusion zone. The observed decrease in fracture strength with titanium inoculation was attributed to increased spacing of second phase particles in the fusion zone. Current research has focused on the weldability of zirconium- and carbon-alloyed iron aluminides. Preliminary work performed at Oak Ridge National Laboratory has shown that zirconium and carbon additions affect the weldability of the alloy as well as the mechanical properties and fracture behavior of the weldments. A sigmajig hot cracking test apparatus has been constructed and tested at Colorado School of Mines. Preliminary characterization of hot cracking of three zirconium- and carbon-alloyed iron aluminides, each containing a different total concentration of zirconium at a constant zirconium/carbon ratio of ten, is in progress. Future testing will include low zirconium alloys at zirconium/carbon ratios of five and one, as well as high zirconium alloys (1.5 to 2.0 atomic percent) at zirconium/carbon ratios of ten to forty.
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Phase change of iron ore reduction process using EFB as reducing agent at 900-1200°C
Purwanto, H.; Salleh, H. M.; Rozhan, A. N.; Mohamad, A. S.; Zakiyuddin, A.
2018-04-01
Treatment of low grade iron ore involved reduction of oxygen in iron oxide by using reductant such as carbon monoxide or hydrogen gas. Presently, carboneous materials such as coke/coal are widely used as a source to provide reducing gas, but some problem arises from this material as the gas can harm the environments. Therefore, empty fruit bunch biomass from oil palm becomes an alternative to replace the usage of coke/coal as their major composition is carbon and hydrogen. The idea of replacing coke with biomass will reduce the amount of carbon dioxide release as biomass is a carbon neutral and renewable source, and at the same time abundance of waste from oil palm industries can be overcome. Therefore, the aim of this research is to upgrade the low grade iron with reducibility more than 50% being used in iron and steel making. In this research, low grade iron ore are mixed together with EFB then is making into composite pellet before being reduced at certain parameter chosen. The variables involved in this research is composition EFB (10%, 30% and 50%), temperature (1000°C, 1100°C and 1200°C) and reduction time is fixed with 30 minutes. From the experiment conducted, the highest reducibility achieved is 76.37% at temperature 1200°C. While XRD analysis shows the existence of metallic iron phase started to form at 1000°C with composition of 30% of EFB. Meanwhile, from magnetization test show that at 1200°C the highest magnetic susceptibility is achieved as the dominance phase at 1200°C is metallic phase. Therefore it is an interesting alternative to replace coke with biomass for reducing agent in upgrading low grade iron into workable ores.
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Cepeda-Lopez, A.C.; Melse, A.; Zimmermann, M.B.; Herter-Aeberli, I.
2015-01-01
Background: Iron deficiency is common in overweight and obese individuals. This deficiency may be due to adiposity-related inflammation that increases serum hepcidin and decreases dietary iron absorption. Because hepcidin reduces iron efflux from the basolateral enterocyte, it is uncertain whether
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Study on Increasing High Temperature pH(t) to Reduce Iron Corrosion Products
International Nuclear Information System (INIS)
Shin, Dong Man; Hur, Nam Yong; Kim, Waang Bae
2011-01-01
The transportation and deposition of iron corrosion products are important elements that affect both the steam generator (SG) integrity and secondary system in pressurized water reactor (PWR) nuclear power plants. Most of iron corrosion products are generated on carbon steel materials due to flow accelerated corrosion (FAC). The several parameters like water chemistry, temperature, hydrodynamic, and steel composition affect FAC. It is well established that the at-temperature pH of the deaerated water system has a first order effect on the FAC rate of carbon steels through nuclear industry researches. In order to reduce transportation and deposition of iron corrosion products, increasing pH(t) tests were applied on secondary system of A, B units. Increasing pH(t) successfully reduced flow accelerated corrosion. The effect of increasing pH(t) to inhibit FAC was identified through the experiment and pH(t) evaluation in this paper
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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.)
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Non-LTE line-blanketed model atmospheres of hot stars. 2: Hot, metal-rich white dwarfs
Lanz, T.; Hubeny, I.
1995-01-01
We present several model atmospheres for a typical hot metal-rich DA white dwarf, T(sub eff) = 60,000 K, log g = 7.5. We consider pure hydrogen models, as well as models with various abundances of two typical 'trace' elements-carbon and iron. We calculte a number of Local Thermodynamic Equilibrium (LTE) and non-LTE models, taking into account the effect of numerous lines of these elements on the atmospheric structure. We demostrate that while the non-LTE effects are notvery significant for pure hydrogen models, except for describing correctly the central emission in H-alpha they are essential for predicting correctly the ionization balance of metals, such as carbon and iron. Previously reported discrepancies in LTE abundances determinations using C III and C IV lines are easily explained by non-LTE effects. We show that if the iron abundance is larger than 10(exp -5), the iron line opacity has to be considered not only for the spectrum synthesis, but also in the model construction itself. For such metal abundances, non-LTE metal line-blanketed models are needed for detailed abundance studies of hot, metal-rich white dwarfs. We also discuss the predicted Extreme Ultraviolet (EUV) spectrum and show that it is very sensitive to metal abundances, as well as to non-LTE effects.
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Corrosion of Iron by Sulfate-Reducing Bacteria: New Views of an Old Problem
Garrelfs, Julia
2014-01-01
About a century ago, researchers first recognized a connection between the activity of environmental microorganisms and cases of anaerobic iron corrosion. Since then, such microbially influenced corrosion (MIC) has gained prominence and its technical and economic implications are now widely recognized. Under anoxic conditions (e.g., in oil and gas pipelines), sulfate-reducing bacteria (SRB) are commonly considered the main culprits of MIC. This perception largely stems from three recurrent observations. First, anoxic sulfate-rich environments (e.g., anoxic seawater) are particularly corrosive. Second, SRB and their characteristic corrosion product iron sulfide are ubiquitously associated with anaerobic corrosion damage, and third, no other physiological group produces comparably severe corrosion damage in laboratory-grown pure cultures. However, there remain many open questions as to the underlying mechanisms and their relative contributions to corrosion. On the one hand, SRB damage iron constructions indirectly through a corrosive chemical agent, hydrogen sulfide, formed by the organisms as a dissimilatory product from sulfate reduction with organic compounds or hydrogen (“chemical microbially influenced corrosion”; CMIC). On the other hand, certain SRB can also attack iron via withdrawal of electrons (“electrical microbially influenced corrosion”; EMIC), viz., directly by metabolic coupling. Corrosion of iron by SRB is typically associated with the formation of iron sulfides (FeS) which, paradoxically, may reduce corrosion in some cases while they increase it in others. This brief review traces the historical twists in the perception of SRB-induced corrosion, considering the presently most plausible explanations as well as possible early misconceptions in the understanding of severe corrosion in anoxic, sulfate-rich environments. PMID:24317078
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Control Strategies to Reduce the Energy Consumption of Central Domestic Hot Water Systems
Energy Technology Data Exchange (ETDEWEB)
Dentz, Jordan [The Levy Partnership, Inc., New York, NY (United States). Advanced Residential Integrated Energy Solutions; Ansanelli, Eric [The Levy Partnership, Inc., New York, NY (United States). Advanced Residential Integrated Energy Solutions; Henderson, Hugh [The Levy Partnership, Inc., New York, NY (United States). Advanced Residential Integrated Energy Solutions; Varshney, Kapil [The Levy Partnership, Inc., New York, NY (United States). Advanced Residential Integrated Energy Solutions
2016-06-23
Domestic hot water (DHW) heating is the second largest energy end use in U.S. buildings, exceeded only by space conditioning. Recirculation systems consisting of a pump and piping loop(s) are commonly used in multifamily buildings to reduce wait time for hot water at faucets; however, constant pumping increases energy consumption by exposing supply and return line piping to continuous heat loss, even during periods when there is no demand for hot water. In this study, ARIES installed and tested two types of recirculation controls in a pair of buildings in order to evaluate their energy savings potential. Demand control, temperature modulation controls, and the simultaneous operation of both were compared to the baseline case of constant recirculation. Additionally, interactive effects between DHW control fuel reductions and space conditioning (heating and cooling) were estimated in order to make more realistic predictions of the payback and financial viability of retrofitting DHW systems with these controls. Results showed that DHW fuel consumption reduced by 7% after implementing the demand control technique, 2% after implementing temperature modulation, and 15% after implementing demand control and temperature modulation techniques simultaneously; recirculation pump runtime was reduced to 14 minutes or less per day. With space heating and cooling interactions included, the estimated annual cost savings were 8%, 1%, and 14% for the respective control techniques. Possible complications in the installation, commissioning and operation of the controls were identified and solutions offered.
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Control Strategies to Reduce the Energy Consumption of Central Domestic Hot Water Systems
Energy Technology Data Exchange (ETDEWEB)
Dentz, Jordan; Ansanelli, Eric; Henderson, Hugh; Varshney, Kapil
2016-06-03
Domestic hot water (DHW) heating is the second largest energy end use in U.S. buildings, exceeded only by space conditioning. Recirculation systems consisting of a pump and piping loop(s) are commonly used in multifamily buildings to reduce wait time for hot water at faucets; however, constant pumping increases energy consumption by exposing supply and return line piping to continuous heat loss, even during periods when there is no demand for hot water. In this study, ARIES installed and tested two types of recirculation controls in a pair of buildings in order to evaluate their energy savings potential. Demand control, temperature modulation controls, and the simultaneous operation of both were compared to the baseline case of constant recirculation. Additionally, interactive effects between DHW control fuel reductions and space conditioning (heating and cooling) were estimated in order to make more realistic predictions of the payback and financial viability of retrofitting DHW systems with these controls. Results showed that DHW fuel consumption reduced by 7% after implementing the demand control technique, 2% after implementing temperature modulation, and 15% after implementing demand control and temperature modulation techniques simultaneously; recirculation pump runtime was reduced to 14 minutes or less per day. With space heating and cooling interactions included, the estimated annual cost savings were 8%, 1%, and 14% for the respective control techniques. Possible complications in the installation, commissioning and operation of the controls were identified and solutions offered.
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Diffusion Coefficient in the Zinc Coating Shaped on the Surface of Cast Iron and Steel Alloys
Directory of Open Access Journals (Sweden)
Kopyciński D.
2015-06-01
Full Text Available The article presents the method to assess the diffusion coefficient D in the sub-layer of intermetallic phases formed during hot-dip galvanizing “Armco” iron and ductile cast iron EN-GJS-500-7. Hot-dip galvanizing is one of the most popular forms of long-term protection of Fe-C alloys against corrosion. The process for producing a protective layer of sufficient quality is closely related to diffusion of atoms of zinc and iron. The simulation consist in performed a hot-dip galvanizing in laboratory condition above Fe-C alloys, in the Department of Engineering of Cast Alloys and Composites. Galvanizing time ranged from 15 to 300 seconds. Then metallographic specimens were prepared, intermetallic layers were measured and diffusion coefficient (D were calculated. It was found that the diffusion coefficient obtained during hot-dip galvanizing “Armco” iron and zinc is about two orders of magnitude less than the coefficient obtained on ductile cast iron EN-GJS-500-7.
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Hydrogenation of carbon to methane in reduced sponge iron, chromium, and ferrochromium
Energy Technology Data Exchange (ETDEWEB)
Qayyum, M A; Reeve, D A
1976-01-01
Hydrogenation of excess carbon to methane in reduced sponge iron, chromium and ferrochromium under isothermal and temperature-programmed conditions indicates that it is possible to control the residual carbon content of the metallized products which may be an advantage if further processing of the products is contemplated. Hydrogenation starts above 800/sup 0/C and a shrinking-core kinetic model fits the experimental data. The mean apparent activation energy for the hydrogenation of residual carbon to methane in sponge iron, chromium and ferrochromium is 21 kcal/mole.
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Teutsch, N.; Berg, M.; von Gunten, U.; Halliday, A.
2004-12-01
In reduced groundwater iron is involved in biotic and abiotic transformation processes, both of which could lead to iron isotope fractionation. The reduced groundwater aquifers in the area of the Vietnamese capital of Hanoi are the main drinking water sources for the city. These groundwaters contain arsenic, which imposes a serious health threat to millions of people. Dissolved arsenic is related to the reducing conditions prevalent in the groundwater, and iron and arsenic contents are correlated in the sediments. We are employing iron isotope composition as a tool to better understand the processes leading to the transformation of iron in the groundwater and its role in various biogeochemical processes in reduced environments. Drinking water is supplied to the city of Hanoi from several water treatment plants (WTP) which pump the raw groundwater from a lower aquifer, while the rural surroundings pump untreated groundwater from an upper aquifer by private tubewells. Surface water from the Red River delta is the main source of recharge to these two aquifers. Due to high content of particulate natural organic matter (NOM) in the sediment leading to extensive microbial activity, the groundwaters are anoxic and rich in dissolved iron(II). The iron(II) removal in the WTPs is carried by a multi-step treatment including aeration, settling, filtration, and chlorination. We have collected natural groundwater samples for isotopic analysis from two aquifers at several locations, a groundwater depth profile and its corresponding sediment phases from the upper aquifer and the underlying aquitard, raw and treated water from several WTPs, as well as the corresponding iron(III) precipitates. The iron concentrations of groundwaters analysed in this study range from 3 to 28 mg/L and δ 57Fe (57/54 deviation from IRMM 014) values vary between -1.2 and +1.5 ‰ . The sediment depth profile has a δ 57Fe around +0.3 ‰ , which implies that the high values obtained in the groundwater
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Raoultella sp. SM1, a novel iron-reducing and uranium-precipitating strain.
Sklodowska, Aleksandra; Mielnicki, Sebastian; Drewniak, Lukasz
2018-03-01
The main aim of this study was the characterisation of novel Raoutella isolate, an iron-reducing and uranium-precipitating strain, originating from microbial mats occurring in the sediments of a closed down uranium mine in Kowary (SW Poland). Characterisation was done in the context of its potential role in the functioning of these mats and the possibility to use them in uranium removal/recovery processes. In our experiment, we observed the biological precipitation of iron and uranium's secondary minerals containing oxygen, potassium, sodium and phosphor, which were identified as ningyoite-like minerals. The isolated strain, Raoultella sp. SM1, was also able to dissimilatory reduce iron (III) and uranium (VI) in the presence of citrate as an electron donor. Our studies allowed us to characterise a new strain which may be used as a model microorganism in the study of Fe and U respiratory processes and which may be useful in the bioremediation of uranium-contaminated waters and sediments. During this process, uranium may be immobilised in ningyoite-like minerals and can then be recovered in nano/micro-particle form, which may be easily transformed to uraninite. Copyright © 2017 Elsevier Ltd. All rights reserved.
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Transformation of vivianite by anaerobic nitrate-reducing iron-oxidizing bacteria.
Miot, J; Benzerara, K; Morin, G; Bernard, S; Beyssac, O; Larquet, E; Kappler, A; Guyot, F
2009-06-01
In phosphate-rich environments, vivianite (Fe(II)(3)(PO(4))(2), 8H(2)O) is an important sink for dissolved Fe(II) and is considered as a very stable mineral due to its low solubility at neutral pH. In the present study, we report the mineralogical transformation of vivianite in cultures of the nitrate-reducing iron-oxidizing bacterial strain BoFeN1 in the presence of dissolved Fe(II). Vivianite was first transformed into a greenish phase consisting mostly of an amorphous mixed valence Fe-phosphate. This precipitate became progressively orange and the final product of iron oxidation consisted of an amorphous Fe(III)-phosphate. The sub-micrometer analysis by scanning transmission X-ray microscopy of the iron redox state in samples collected at different stages of the culture indicated that iron was progressively oxidized at the contact of the bacteria and at a distance from the cells in extracellular minerals. Iron oxidation in the extracellular minerals was delayed by a few days compared with cell-associated Fe-minerals. This led to strong differences of Fe redox in between these two types of minerals and finally to local heterogeneities of redox within the sample. In the absence of dissolved Fe(II), vivianite was not significantly transformed by BoFeN1. Whereas Fe(II) oxidation at the cell contact is most probably directly catalyzed by the bacteria, vivianite transformation at a distance from the cells might result from oxidation by nitrite. In addition, processes leading to the export of Fe(III) from bacterial oxidation sites to extracellular minerals are discussed including some involving colloids observed by cryo-transmission electron microscopy in the culture medium.
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International Nuclear Information System (INIS)
Shirsat, S.G.; Thomas, P.; Nair, P.M.
1991-01-01
Potatoes irradiated to control sprouting were dipped in: hot water (56°C, 5 min; 52°C, 10, 15 and 20 min); cold (25°C, 5 min) or hot (56°C, 5 min) salicylic acid (1000 and 2000 ppm); or sodium hypochlorite (0.1 and 0.2%, 5 min); or dusted with salicylic acid (1 and 2%), to try to reduce the incidence of bacterial soft rot (Erwinia sp.) during controlled temperature (10°C, 15°C) and ambient temperature (20–34°C) storage. All treatments, particularly hot water and hot salicylic acid dip, increased microbial spoilage, possibly as a result of handling damage during the treatments combined with the inhibition of wound periderm formation as a result of irradiation. Storing irradiated tubers in well ventilated containers reduced soft rot compared to storing them in sacks and after 6 months storage at 10, 15 and 20–34°C, 95, 90 and 77% respectively were healthy and marketable. (author)
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Directory of Open Access Journals (Sweden)
Ceth W. Parker
2013-11-01
Full Text Available The iron mining regions of Brazil contain thousands of “iron ore caves” (IOCs that form within Fe(III-rich deposits. The mechanisms by which these IOCs form remain unclear, but the reductive dissolution of Fe(III (hydroxides by Fe(III reducing bacteria (FeRB could provide a microbiological mechanism for their formation. We evaluated the susceptibility of Fe(III deposits associated with these caves to reduction by the FeRB Shewanella oneidensis MR-1 to test this hypothesis. Canga, an Fe(III-rich duricrust, contained poorly crystalline Fe(III phases that were more susceptible to reduction than the Fe(III (predominantly hematite associated with banded iron formation (BIF, iron ore, and mine spoil. In all cases, the addition of a humic acid analogue enhanced Fe(III reduction, presumably by shuttling electrons from S. oneidensis to Fe(III phases. The particle size and quartz-Si content of the solids appeared to exert control on the rate and extent of Fe(III reduction by S. oneidensis, with more bioreduction of Fe(III associated with solid phases containing more quartz. Our results provide evidence that IOCs may be formed by the activities of Fe(III reducing bacteria (FeRB, and the rate of this formation is dependent on the physicochemical and mineralogical characteristics of the Fe(III phases of the surrounding rock.
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Korenaga, Masaaki; Nishina, Sohji; Korenaga, Keiko; Tomiyama, Yasuyuki; Yoshioka, Naoko; Hara, Yuichi; Sasaki, Yusuke; Shimonaka, Yasushi; Hino, Keisuke
2015-01-01
Background & Aims Branched-chain amino acids (BCAA) reduce the incidence of hepatocellular carcinoma (HCC) in patients with cirrhosis. However, the mechanisms that underlie these effects remain unknown. Previously, we reported that oxidative stress in male transgenic mice that expressed hepatitis C virus polyprotein (HCVTgM) caused hepatic iron accumulation by reducing hepcidin transcription, thereby leading to HCC development. This study investigated whether long-term treatment with BCAA reduced hepatic iron accumulation and oxidative stress in iron-overloaded HCVTgM and in patients with HCV-related advanced fibrosis. Methods Male HCVTgM were fed an excess-iron diet that comprised either casein or 3.0% BCAA, or a control diet, for 6 months. Results For HCVTgM, BCAA supplementation increased the serum hepcidin-25 levels and antioxidant status [ratio of biological antioxidant potential (BAP) relative to derivatives of reactive oxygen metabolites (dROM)], decreased the hepatic iron contents, attenuated reactive oxygen species generation, and restored mitochondrial superoxide dismutase expression and mitochondrial complex I activity in the liver compared with mice fed the control diet. After 48 weeks of BCAA supplementation in patients with HCV-related advanced fibrosis, BAP/dROM and serum hepcidin-25 increased and serum ferritin decreased compared with the pretreatment levels. Conclusions BCAA supplementation reduced oxidative stress by restoring mitochondrial function and improved iron metabolism by increasing hepcidin-25 in both iron-overloaded HCVTgM and patients with HCV-related advanced fibrosis. These activities of BCAA may partially account for their inhibitory effects on HCC development in cirrhosis patients. PMID:25156780
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Energy Technology Data Exchange (ETDEWEB)
Ueki, Y.; Kanayama, M.; Maeda, T.; Nishika, K.; Shimizu, M. [Kyushu University, Fukuoka (Japan). Dept. of Materials Science & Engineering
2007-01-15
The gasification behavior of carbon composite iron ore produced by hot briquetting process was examined under various gas atmospheres such as CO-N{sub 2}, CO{sub 2}-N, and CO-CO{sub 2} at various temperatures. The gasification of coal was affected strongly by atmospheric gas concentration and reaction temperature. Kinetic analysis in various gas atmospheres was carried out by using the first order reaction model, which yields the straight line relation between reaction rate constants for the gasification of coal and the gas concentration. Therefore, reaction rate constants for the gasification of coal in CO-CO{sub 2}-N{sub 2} gas atmosphere were derived.
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Lin, B; van Breukelen, B.M.; van Verseveld, H.W.; Westerhoff, H.V.; Roling, W.F.M.
2005-01-01
Relationships between community composition of the iron-reducing Geobacteraceae, pollution levels, and the occurrence of biodegradation were established for an iron-reducing aquifer polluted with landfill leachate by using cultivation-independent Geobacteraceae 16S rRNA gene-targeting techniques.
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Lin, B.; Braster, M.; van Breukelen, B.M.; van Verseveld, H.W.; Westerhoff, H.V.; Roling, W.F.M.
2005-01-01
Relationships between community composition of the iron-reducing Geobacteraceae, pollution levels, and the occurrence of biodegradation were established for an iron-reducing aquifer polluted with landfill leachate by using cultivation-independent Geobacteraceae 16S rRNA gene-targeting techniques.
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High-BTU gas production from tar-bearing hot coke oven gas over iron catalyst
Energy Technology Data Exchange (ETDEWEB)
L.Y. Li; K. Morishita; T. Takarada [Gunma University, Gunma (Japan). Department of Biological and Chemical Engineering
2005-07-01
To utilize the tar-bearing hot coke oven gas (the by-product of coke making process) more effectively, a process was developed by converting the hot coke oven gas into a methane rich high-BTU gas over iron-bearing catalysts. The catalytic behaviour of Indonesian limonite ore was mainly discussed. For a reference, a conventional nickel catalyst (Ni/Al{sub 2}O{sub 3}) was employed. Laboratory scale tests were carried out in a two-stage fixed-bed reactor at ambient pressure. A bituminous coal sample was heated at first stage, the volatiles was carried by feed gas and decomposed at second stage. The limonite promoted hydropyrolysis of coal volatiles similar to Ni/Al{sub 2}O{sub 3} catalyst. High yields of total product gas and methane were obtained at 50 vol.% hydrogen atmosphere with a feed gas of 60 ml min{sup -1} hydrogen and 60 ml min{sup -1} nitrogen. After experiments, hydrocarbons heavier than ethane were not observed. Also that, carbon balance was more than 99.8% in coal char, product gases and carbon deposits. It was considered that coal volatiles converted into light gases and carbon almost completely in catalyst bed. Yields of product gas and methane depended upon catalytic temperature. At 923 K, the maximum yield of product gas was achieved at 74.3% for limonite catalyst on carbon balance with methane 83.2 vol.% of the carbonaceous gas products. Comparing with limonite, Fe/Al{sub 2}O{sub 3} and BOF dust samples showed low activities on coal volatiles catalytic decomposition. 21 refs., 5 figs., 3 tabs.
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Role of tin as a reducing agent in iron containing heat absorbing ...
Indian Academy of Sciences (India)
Unknown
infrared region and a narrow weak band for Fe3+ ion at its λmax at around 380 nm was observed in the silicate glass. ... Tin reducing agent; iron heat absorption; silicate glass. 1. ... ing point of aluminium metal is far below than the glass.
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Aaron, R. B.; Zheng, Q.; Flynn, P.; Singha, K.; Brantley, S.
2008-12-01
Three flow-through columns outfitted with Ag/AgCl electrodes were constructed to test the effects of different microbial processes on the geophysical measurements of self potential (SP), bulk electrical conductivity (σ b), and induced polarization (IP). The columns were filled with sieved, Fe-bearing subsurface sediment from the Delmarva Peninsula near Oyster, VA, inoculated (9:1 ratio) with a freshly-collected, shallow subsurface sediment from a wetland floodplain (Dorn Creek) near Madison, WI. Each of the columns was fed anoxic and sterile PIPES buffered artificial groundwater (PBAGW) containing different concentrations of acetate and nitrate. The medium fed to Column 1 (nitrate-reducing) was amended with 100 μM acetate and 2 mM nitrate. Column 2 (iron-reducing) was run with PBAGW containing 1.0 mM acetate and 0 mM nitrate. Column 3 (alternating redox state) was operated under conditions designed to alternately stimulate nitrate-reducing and iron-reducing populations to provide conditions, i.e., the presence of both nitrate and microbially-produced Fe(II), that would allow growth of nitrate-dependent Fe(II)-oxidizing populations. We operated Column 3 with a cycling strategy of 14-18 days of high C medium (1 mM acetate and 100 μ M nitrate) followed by 14-18 days of low C medium (100 μ M acetate and 2 mM nitrate). Effluent chemistry (NO3-, NO2-, NH4+, acetate, and Fe2+) was sampled daily for four months so as to be concurrent with the electrical measurements. We observed chemical evidence of iron reduction (dissolved [Fe(II)] = 0.2mM) in the effluent from the iron reduction and alternating redox columns. Chemical depletion of NO3- ([NO3-] ranged from 1 to 0.02mM), the production of NO2-, and possible production of NH4+ (0.2 mM) was observed in the nitrate reducing column as well as the alternating redox column. All three columns displayed loss of acetate as microbial activity progressed. σ b remained constant in the alternating redox column (~0.15 S
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Multiple hearth furnace for reducing iron oxide
Brandon, Mark M [Charlotte, NC; True, Bradford G [Charlotte, NC
2012-03-13
A multiple moving hearth furnace (10) having a furnace housing (11) with at least two moving hearths (20) positioned laterally within the furnace housing, the hearths moving in opposite directions and each moving hearth (20) capable of being charged with at least one layer of iron oxide and carbon bearing material at one end, and being capable of discharging reduced material at the other end. A heat insulating partition (92) is positioned between adjacent moving hearths of at least portions of the conversion zones (13), and is capable of communicating gases between the atmospheres of the conversion zones of adjacent moving hearths. A drying/preheat zone (12), a conversion zone (13), and optionally a cooling zone (15) are sequentially positioned along each moving hearth (30) in the furnace housing (11).
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International Nuclear Information System (INIS)
Ngoi, Kuan Hoon; Chia, Chin-Hua; Zakaria, Sarani; Chiu, Wee Siong
2015-01-01
We report on the effect of using reducing agents with different chain-length on the synthesis of iron oxide nanoparticles by thermal decomposition of iron (III) acetylacetonate in 1-octadecene. This modification allows us to control the shape of nanoparticles into spherical and cubic iron oxide nanoparticles. The highly monodisperse 14 nm spherical nanoparticles are obtained under 1,2-dodecanediol and average 14 nm edge-length cubic iron oxide nanoparticles are obtained under 1,2-tetradecanediol. The structural characterization such as transmission electron microscope (TEM) and X-ray diffraction (XRD) shows similar properties between two particles with different shapes. The vibrating sample magnetometer (VSM) shows no significant difference between spherical and cubic nanoparticles, which are 36 emu/g and 37 emu/g respectively and superparamagnetic in nature
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Energy Technology Data Exchange (ETDEWEB)
Ngoi, Kuan Hoon; Chia, Chin-Hua, E-mail: chia@ukm.edu.my; Zakaria, Sarani [School of Applied Physics, Faculty Science and Technology, University Kebangsaan Malaysia 43600 UKM Bangi, Selangor (Malaysia); Chiu, Wee Siong [Low Dimensional Materials Research Centre, Department of Physics, Faculty of Science, University of Malaya, 50603 Lembah Pantai, Kuala Lumpur (Malaysia)
2015-09-25
We report on the effect of using reducing agents with different chain-length on the synthesis of iron oxide nanoparticles by thermal decomposition of iron (III) acetylacetonate in 1-octadecene. This modification allows us to control the shape of nanoparticles into spherical and cubic iron oxide nanoparticles. The highly monodisperse 14 nm spherical nanoparticles are obtained under 1,2-dodecanediol and average 14 nm edge-length cubic iron oxide nanoparticles are obtained under 1,2-tetradecanediol. The structural characterization such as transmission electron microscope (TEM) and X-ray diffraction (XRD) shows similar properties between two particles with different shapes. The vibrating sample magnetometer (VSM) shows no significant difference between spherical and cubic nanoparticles, which are 36 emu/g and 37 emu/g respectively and superparamagnetic in nature.
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Maisch, Markus; Murata, Chihiro; Unger, Julia; Kappler, Andreas; Schmidt, Caroline
2015-04-01
Rice is the major food source for more than half of the world population and 80 percent of the worldwide rice cultivation is performed on water logged paddy soils. The establishment of reducing conditions in the soil and across the soil-water interface not only stimulates the microbial production and release of the greenhouse gas methane. These settings also create optimal conditions for microbial iron(III) reduction and therefore saturate the system with reduced ferrous iron. Through the reduction and dissolution of ferric minerals that are characterized by their high surface activity, sorbed nutrients and contaminants (e.g. arsenic) will be mobilized and are thus available for uptake by plants. Rice plants have evolved a strategy to release oxygen from their roots in order to prevent iron toxification in highly ferrous environments. The release of oxygen to the reduced paddy soil causes ferric iron plaque formation on the rice roots and finally increases the sorption capacity for toxic metals. To this date the geochemical and microbiological processes that control the formation of iron plaque are not deciphered. It has been hypothesized that iron(II)-oxidizing bacteria play a potential role in the iron(III) mineral formation along the roots. However, not much is known about the actual processes, mineral products, and geochemical gradients that establish within the rhizosphere. In the present study we have developed a growth set-up that allows the co-cultivation of rice plants and iron(II)-oxidizing bacteria, as well as the visual observation and in situ measurement of geochemical parameters. Oxygen and dissolved iron(II) gradients have been measured using microelectrodes and show geochemical hot spots that offer optimal growth conditions for microaerophilic iron(II) oxidizers. First mineral identification attempts of iron plaque have been performed using Mössbauer spectroscopy and microscopy. The obtained results on mineraology and crystallinity have been
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Enning, Dennis; Venzlaff, Hendrik; Garrelfs, Julia; Dinh, Hang T; Meyer, Volker; Mayrhofer, Karl; Hassel, Achim W; Stratmann, Martin; Widdel, Friedrich
2012-01-01
Iron (Fe0) corrosion in anoxic environments (e.g. inside pipelines), a process entailing considerable economic costs, is largely influenced by microorganisms, in particular sulfate-reducing bacteria (SRB). The process is characterized by formation of black crusts and metal pitting. The mechanism is usually explained by the corrosiveness of formed H2S, and scavenge of ‘cathodic’ H2 from chemical reaction of Fe0 with H2O. Here we studied peculiar marine SRB that grew lithotrophically with metallic iron as the only electron donor. They degraded up to 72% of iron coupons (10 mm × 10 mm × 1 mm) within five months, which is a technologically highly relevant corrosion rate (0.7 mm Fe0 year−1), while conventional H2-scavenging control strains were not corrosive. The black, hard mineral crust (FeS, FeCO3, Mg/CaCO3) deposited on the corroding metal exhibited electrical conductivity (50 S m−1). This was sufficient to explain the corrosion rate by electron flow from the metal (4Fe0 → 4Fe2+ + 8e−) through semiconductive sulfides to the crust-colonizing cells reducing sulfate (8e− + SO42− + 9H+ → HS− + 4H2O). Hence, anaerobic microbial iron corrosion obviously bypasses H2 rather than depends on it. SRB with such corrosive potential were revealed at naturally high numbers at a coastal marine sediment site. Iron coupons buried there were corroded and covered by the characteristic mineral crust. It is speculated that anaerobic biocorrosion is due to the promiscuous use of an ecophysiologically relevant catabolic trait for uptake of external electrons from abiotic or biotic sources in sediments. PMID:22616633
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16S RRNA Gene Analysis of Chlorate Reducing Thermophilic Bacteria From Local Hot Spring
Aminin, Agustina L. N; Katulistiwasari, Puri; Mulyani, Nies Suci
2011-01-01
Chlorates waste remediation by biological processes has been the object of current research. Strain CR, the chlorate reducing bacteria was isolated from Gedongsongo hot spring using minimal medium broth containing chlorates and acetate at 55oC. The determination of chlorate reduction from medium was carried out using turbidimetric method. CR isolate showed reducing ability 18% after four days of incubation. The phenotypic character of CR isolate including rod-shaped cells, gram-positive bacte...
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Evaluation of advanced hot conditioning process for PHWRS
International Nuclear Information System (INIS)
Chandramohan, P.; Srinivasan, M.P.; Velmurugan, S.
2015-01-01
Hot-conditioning/hot functional test process is carried out to the PHT system of reactor before reactor going to critical/operational. The process is aimed in checking the component functionalities at high temperature and high pressure conditions, the process also checks/removes the suspended corrosion products in heat transport circuit. This process leads to formation of a passive or corrosion oxide film on the heat transport circuit surfaces which protects/mitigates the corrosion of the system circuits during the operation of plant. Major concerned alloy in the Primary Heat Transport (PHT) system of Indian PHWRs during the hot conditioning process and also during operation is the carbon steel due to its high corrosion. Hot-conditioning process mitigates the corrosion of carbon steel by the formation of iron oxide (Fe 3 O 4 ) as major oxide phase layer on the carbon steel surface with a typical thickness of 1.0 μm with particle size of 1μm after 336 h of process at 250 °C. But this passive oxide film thickness increase with time of operation of system with c.a. 10μm for 2.2 EFYP. The protectiveness of passive layer can be further enhanced by reducing the particle sizes in the passive film to nano meter range. The process can impact on the compactness of passive oxide layer with reduced pores in the oxide layer and properties of the nano nature oxide (transport properties) impacting the corrosion mitigation. The corrosion mitigation reduce the source term in the activated corrosion product generation. To achieve this a new process 'Advanced hot conditioning' was developed in water steam chemistry division, BARC for getting a passive oxide film with a lowered particle size in the passive film. The AHC process with 1g/L of PEG-8000 at 250 °C for 336 h showed a particle size <100 nm. The process was tested under the normal operating conditions as function of the time, the corrosion parameter like oxide film thickness, corrosion rate and metal ion
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Erber, R; Wulf, M; Becker-Birck, M; Kaps, S; Aurich, J E; Möstl, E; Aurich, C
2012-02-01
Branding is the traditional and well-established method used to mark horses, but recently microchip transponders for implantation have become available. In this study, behaviour, physiological stress variables and skin temperature in foals were determined in response to hot-iron branding (n=7) and microchip implantation (n=7). Salivary cortisol concentrations increased in response to branding (1.8 ± 0.2 ng/mL) and microchip implantation (1.4 ± 0.1ng/mL), but cortisol release over time did not differ. In response to both manipulations there was a transient increase in heart rate (PBranding and microchip implantation induced a comparable aversive behaviour (branding, score 3.86 ± 0.85; microchip, score 4.00 ± 0.82). Both techniques thus caused similar physiological and behavioural changes indicative of stress. Acutely, implantation of a microchip was as stressful as branding in foals. Branding caused a necrotising skin burn lasting at least 7 days. Moreover branding, but not microchip implantation (P<0.001), was accompanied by a generalized increase in skin temperature which was comparable to low degree post-burn hypermetabolism in humans. Copyright © 2011 Elsevier Ltd. All rights reserved.
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H2S adsorption and decomposition on the gradually reduced α-Fe2O3(001) surface: A DFT study
Lin, Changfeng; Qin, Wu; Dong, Changqing
2016-11-01
Reduction of iron based desulfurizer occurs during hot gas desulfurization process, which will affect the interaction between H2S and the desulfurizer surface. In this work, a detailed adsorption behavior and dissociation mechanism of H2S on the perfect and reduced α-Fe2O3(001) surfaces, as well as the correlation between the interaction characteristic and reduction degree of iron oxide, have been studied by using periodic density functional theory (DFT) calculations. Results demonstrate that H2S firstly chemisorbs on surface at relatively higher oxidation state (reduction degree χ 33%. Reduction of iron oxide benefits the H2S adsorption. Further, dissociation processes of H2S via molecular and dissociative adsorption were investigated. Results show that after reduction of Fe2O3 into the oxidation state around FeO and Fe, the reduced surface exhibits very strong catalytic capacity for H2S decomposition into S species. Meanwhile, the overall dissociation process on all surfaces is exothermic. These results provide a fundamental understanding of reduction effect of iron oxide on the interaction mechanism between H2S and desulfurizer surface, and indicate that rational control of reduction degree of desulfurizer is essential for optimizing the hot gas desulfurization process.
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Walker, K A; Mellish, J E; Weary, D M
2011-10-01
This study assessed the heart rate, breathing rate and behavioural responses of 12 juvenile Steller sea lions during hot-iron branding under isoflurane anaesthesia. Physiological and behavioural measures were recorded in four periods: baseline (five minutes), sham branding (one minute), branding (approximately 2.7 minutes) and postbranding (five minutes). No difference in heart rate was noted from baseline to sham branding, but heart rate increased from mean (sem) 78.3 (2.4) bpm in the baseline period to 85.6 (2.5) bpm in the branding period. Heart rate remained elevated in the postbranding period, averaging 84.7 (2.5) bpm. Breathing rate averaged 2.5 (1.0) breaths/minute in the baseline and sham branding periods increased to 8.9 (1.0) breaths/minute during branding, but returned to baseline by the postbranding period. Behaviourally, half of the sea lions exhibited trembling and head and shoulder movements during branding.
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Huang, Xiao-Tian; Qian, Zhong-Ming; He, Xuan; Gong, Qi; Wu, Ka-Chun; Jiang, Li-Rong; Lu, Li-Na; Zhu, Zhou-Jing; Zhang, Hai-Yan; Yung, Wing-Ho; Ke, Ya
2014-05-01
Huperzine A (HupA), a natural inhibitor of acetylcholinesterase derived from a plant, is a licensed anti-Alzheimer's disease (AD) drug in China and a nutraceutical in the United States. In addition to acting as an acetylcholinesterase inhibitor, HupA possesses neuroprotective properties. However, the relevant mechanism is unknown. Here, we showed that the neuroprotective effect of HupA was derived from a novel action on brain iron regulation. HupA treatment reduced insoluble and soluble beta amyloid levels, ameliorated amyloid plaques formation, and hyperphosphorylated tau in the cortex and hippocampus of APPswe/PS1dE9 transgenic AD mice. Also, HupA decreased beta amyloid oligomers and amyloid precursor protein levels, and increased A Disintegrin And Metalloprotease Domain 10 (ADAM10) expression in these treated AD mice. However, these beneficial effects of HupA were largely abolished by feeding the animals with a high iron diet. In parallel, we found that HupA decreased iron content in the brain and demonstrated that HupA also has a role to reduce the expression of transferrin-receptor 1 as well as the transferrin-bound iron uptake in cultured neurons. The findings implied that reducing iron in the brain is a novel mechanism of HupA in the treatment of Alzheimer's disease. Copyright © 2014 Elsevier Inc. All rights reserved.
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The Yuan vs. the Dollar: China and the United States are Already in a "Hot" War
National Research Council Canada - National Science Library
Daly, William R
2005-01-01
...., "Hot" money in FOREX) reigns as an instrument of economic and financial power. Ironically, just as the Cold War symbolically ended with the fall of the Berlin Wall, this Hot War began with another fall...
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Solubility measurement of iron-selenium compounds under reducing conditions. Research document
International Nuclear Information System (INIS)
Kitamura, Akira; Shibata, Masahiro
2003-03-01
Chemical behavior of selenium (Se), which was one of the important elements for performance assessment of geological disposal of high-level radioactive waste, was investigated under reducing and iron-containing conditions. A washing method for an iron diselenide (FeSe 2 (cr)) reagent with acidic and basic solutions (0.1 and 1 M HCl and 1 M NaOH) was carried out for the purification of FeSe 2 reagent, which was considered to be a solubility limiting solid for Se under the geological disposal conditions. Furthermore, solubility of FeSe 2 (cr) was measured in alkaline solution (pH: 11 - 13) under reducing conditions (E h vs SHE: -0.4 - 0 V), and thermodynamic data on equilibrium reactions between Se in solution and Se precipitate were obtained. The dependencies of solubility values on pH and redox potential (E h : vs. standard hydrogen electrode) were best interpreted that the solubility limiting solid was not FeSe 2 (cr) but Se(cr) and the aqueous species was SeO 3 2- in the present experimental conditions. The equilibrium constant between Se(cr) and SeO 3 2- at zero ionic strength was determined and compared with literature values. The chemical behavior of Se under geological disposal conditions was discussed. (author)
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Method of manufacturing iron aluminide by thermomechanical processing of elemental powders
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.
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Reducing tool wear by partial cladding of critical zones in hot form tool by laser metal deposition
Vollmer, Robert; Sommitsch, Christof
2017-10-01
This paper points out a production method to reduce tool wear in hot stamping applications. Usually tool wear can be observed at locally strongly stressed areas superimposed with gliding movement between blank and tool surface. The shown solution is based on a partial laser cladding of the tool surface with a wear resistant coating to increase the lifespan of tool inserts. Preliminary studies showed good results applying a material combination of tungsten carbide particles embedded in a metallic matrix. Different Nickel based alloys welded on hot work tool steel (1.2343) were tested mechanically in the interface zone. The material with the best bonding characteristic is chosen and reinforced with spherical tungsten carbide particles in a second laser welding step. Since the machining of tungsten carbides is very elaborate a special manufacturing strategy is developed to reduce the milling effort as much as possible. On special test specimens milling tests are carried out to proof the machinability. As outlook a tool insert of a b-pillar is coated to perform real hot forming tests.
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Directory of Open Access Journals (Sweden)
Pollock RF
2017-08-01
Full Text Available Richard F Pollock,1 Gorden Muduma2 1Ossian Health Economics and Communications GmbH, Basel, Switzerland; 2Pharmacosmos A/S, Holbaek, Denmark Background and aims: The reported prevalence of iron deficiency anemia (IDA varies widely but estimates suggest that 3% of men and 8% of women have IDA in the UK. Parenteral iron is indicated for patients intolerant or unresponsive to oral iron or requiring rapid iron replenishment. This study evaluated differences in the cost of treating these patients with iron isomaltoside (Monofer®, IIM relative to other intravenous iron formulations. Methods: A budget impact model was developed to evaluate the cost of using IIM relative to ferric carboxymaltose (Ferinject®, FCM, low molecular weight iron dextran (Cosmofer®, LMWID, and iron sucrose (Venofer®, IS in patients with IDA. To establish iron need, iron deficits were modeled using a simplified dosing table. The base case analysis was conducted over 1 year in patients with IDA with mean bodyweight of 82.4 kg (SD 22.5 kg and hemoglobin levels of 9.99 g/dL (SD 1.03 g/dL based on an analysis of patient characteristics in IDA trials. Costs were modeled using UK health care resource groups. Results: Using IIM required 1.3 infusions to correct the mean iron deficit, compared with 1.3, 1.8, and 7.7 with LMWID, FCM, and IS, respectively. Patients using IIM required multiple infusions in 35% of cases, compared with 35%, 77%, and 100% of patients with LMWID, FCM, and IS, respectively. Total costs were estimated to be GBP 451 per patient with IIM or LMWID, relative to GBP 594 with FCM (a GBP 143 or 24% saving with IIM or GBP 2,600 with IS (a GBP 2,149 or 83% saving with IIM. Conclusion: Using IIM or LMWID in place of FCM or IS resulted in a marked reduction in the number of infusions required to correct iron deficits in patients with IDA. The reduction in infusions was accompanied by substantial reductions in cost relative to FCM and IS over 1 year. Keywords: iron
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Iron-57 and iridium-193 Moessbauer spectroscopic studies of supported iron-iridium catalysts
International Nuclear Information System (INIS)
Berry, F.J.; Jobson, S.
1988-01-01
57 Fe and 193 Ir Moessbauer spectroscopy shows that silica- and alumina-supported iron-iridium catalysts formed by calcination in air contain mixtures of small particle iron(III) oxide and iridium(IV) oxide. The iridium dioxide in both supported catalysts is reduced in hydrogen to metallic iridium. The α-Fe 2 O 3 in the silica supported materials is predominantly reduced in hydrogen to an iron-iridium alloy whilst in the alumina-supported catalyst the iron is stabilised by treatment in hydrogen as iron(II). Treatment of a hydrogen-reduced silica-supported iron catalyst in hydrogen and carbon monoxide is accompanied by the formation of iron carbides. Carbide formation is not observed when the iron-iridium catalysts are treated in similar atmospheres. The results from the bimetallic catalysts are discussed in terms of the hydrogenation of associatively adsorbed carbon monoxide and the selectivity of supported iron-iridium catalysts to methanol formation. (orig.)
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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.
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Directory of Open Access Journals (Sweden)
Chalmers AW
2016-02-01
Full Text Available Anna W Chalmers, Jamile M Shammo Department of Internal Medicine, Division of Hematology/Oncology, Rush University Medical Center, Chicago, IL, USA Abstract: Transfusion-dependent anemia is a common feature in a wide array of hematological disorders, including thalassemia, sickle cell disease, aplastic anemia, myelofibrosis, and myelodysplastic syndromes. In the absence of a physiological mechanism to excrete excess iron, chronic transfusions ultimately cause iron overload. Without correction, iron overload can lead to end-organ damage, resulting in cardiac, hepatic, and endocrine dysfunction/failure. Iron chelating agents are utilized to reduce iron overload, as they form a complex with iron, leading to its clearance. Iron chelation has been proven to decrease organ dysfunction and improve survival in certain transfusion-dependent anemias, such as β-thalassemia. Several chelating agents have been approved by the United States Food and Drug Administration for the treatment of iron overload, including deferoxamine, deferiprone, and deferasirox. A variety of factors have to be considered when choosing an iron chelator, including dosing schedule, route of administration, tolerability, and side effect profile. Deferasirox is an orally administered iron chelator with proven efficacy and safety in multiple hematological disorders. There are two formulations of deferasirox, a tablet for suspension, and a new tablet form. This paper is intended to provide an overview of iron overload, with a focus on deferasirox, and its recently approved formulation Jadenu® for the reduction of transfusional iron overload in hematological disorders. Keywords: iron chelation therapy, transfusional iron overload, deferasirox
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Pollock, Richard F; Muduma, Gorden
2017-01-01
The reported prevalence of iron deficiency anemia (IDA) varies widely but estimates suggest that 3% of men and 8% of women have IDA in the UK. Parenteral iron is indicated for patients intolerant or unresponsive to oral iron or requiring rapid iron replenishment. This study evaluated differences in the cost of treating these patients with iron isomaltoside (Monofer ® , IIM) relative to other intravenous iron formulations. A budget impact model was developed to evaluate the cost of using IIM relative to ferric carboxymaltose (Ferinject ® , FCM), low molecular weight iron dextran (Cosmofer ® , LMWID), and iron sucrose (Venofer ® , IS) in patients with IDA. To establish iron need, iron deficits were modeled using a simplified dosing table. The base case analysis was conducted over 1 year in patients with IDA with mean bodyweight of 82.4 kg (SD 22.5 kg) and hemoglobin levels of 9.99 g/dL (SD 1.03 g/dL) based on an analysis of patient characteristics in IDA trials. Costs were modeled using UK health care resource groups. Using IIM required 1.3 infusions to correct the mean iron deficit, compared with 1.3, 1.8, and 7.7 with LMWID, FCM, and IS, respectively. Patients using IIM required multiple infusions in 35% of cases, compared with 35%, 77%, and 100% of patients with LMWID, FCM, and IS, respectively. Total costs were estimated to be GBP 451 per patient with IIM or LMWID, relative to GBP 594 with FCM (a GBP 143 or 24% saving with IIM) or GBP 2,600 with IS (a GBP 2,149 or 83% saving with IIM). Using IIM or LMWID in place of FCM or IS resulted in a marked reduction in the number of infusions required to correct iron deficits in patients with IDA. The reduction in infusions was accompanied by substantial reductions in cost relative to FCM and IS over 1 year.
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Directory of Open Access Journals (Sweden)
Ildefonso Rodriguez-Ramiro
2017-09-01
Full Text Available Iron deficiency is a major public health concern and nutritional approaches are required to reduce its prevalence. The aim of this study was to examine the iron bioavailability of a novel home fortificant, the “Lucky Iron Fish™” (LIF (www.luckyironfish.com/shop, Guelph, Canada and the impact of dietary factors and a food matrix on iron uptake from LIF in Caco-2 cells. LIF released a substantial quantity of iron (about 1.2 mM at pH 2 but this iron was only slightly soluble at pH 7 and not taken up by cells. The addition of ascorbic acid (AA maintained the solubility of iron released from LIF (LIF-iron at pH 7 and facilitated iron uptake by the cells in a concentration-dependent manner. In vitro digestion of LIF-iron in the presence of peas increased iron uptake 10-fold. However, the addition of tannic acid to the digestion reduced the cellular iron uptake 7.5-fold. Additionally, LIF-iron induced an overproduction of reactive oxygen species (ROS, similar to ferrous sulfate, but this effect was counteracted by the addition of AA. Overall, our data illustrate the major influence of dietary factors on iron solubility and bioavailability from LIF, and demonstrate that the addition of AA enhances iron uptake and reduces ROS in the intestinal lumen.
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Ruiz-Urigüen, M.; Jaffe, P. R.
2015-12-01
Autotrophic Acidimicrobiaceae-bacterium named A6 (A6), part of the Actinobacteria phylum have been linked to anaerobic ammonium (NH4+) oxidation under iron reducing conditions. These organisms obtain their energy by oxidizing NH4+ and transferring the electrons to a terminal electron acceptor (TEA). Under environmental conditions, the TEAs are iron oxides [Fe(III)], which are reduced to Fe(II), this process is known as Feammox. Our studies indicate that alternative forms of TEAs can be used by A6, e.g. iron rich clays (i.e. nontronite) and electrodes in bioelectrochemical systems such as Microbial Electrolysis Cells (MECs), which can sustain NH4+removal and A6 biomass production. Our results show that nontronite can support Feammox and promote bacterial cell production. A6 biomass increased from 4.7 x 104 to 3.9 x 105 cells/ml in 10 days. Incubations of A6 in nontronite resulted in up to 10 times more NH4+ removal and 3 times more biomass production than when ferrihydrite is used as the Fe(III) source. Additionally, Fe in nontronite can be reoxidized by aeration and A6 can reutilize it; however, Fe is still finite in the clay. In contrast, in MECs, A6 harvest electrons from NH4+ and use an anode as an unlimited TEA, as a result current is produced. We operated multiple MECs in parallel using a single external power source, as described by Call & Logan (2011). MECs were run with an applied voltage of 0.7V and different growing mediums always containing initial 5mM NH4+. Results show that current production is favored when anthraquinone-2,6-disulfonate (AQDS), an electron shuttled, is present in the medium as it facilitates the transfer of electrons from the bacterial cell to the anode. Additionally, A6 biomass increased from 1 x 104 to 9.77 x 105cells/ml in 14 days of operation. Due to Acidimicrobiaceae-bacterium A6's ability to use various TEAs, MECs represent an alternative, iron-free form, for optimized biomass production of A6 and its application in NH4
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The hypothesis of this study was that iron plaque formed on the roots of wetland plants and their rhizospheres create environmental conditions favorable for iron reducing bacteria that promote the in situ immobilization of uranium. Greenhouse microcosm studies were conducted usin...
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Characterization of the interfacial heat transfer coefficient for hot stamping processes
Luan, Xi; Liu, Xiaochuan; Fang, Haomiao; Ji, Kang; El Fakir, Omer; Wang, LiLiang
2016-08-01
In hot stamping processes, the interfacial heat transfer coefficient (IHTC) between the forming tools and hot blank is an essential parameter which determines the quenching rate of the process and hence the resulting material microstructure. The present work focuses on the characterization of the IHTC between an aluminium alloy 7075-T6 blank and two different die materials, cast iron (G3500) and H13 die steel, at various contact pressures. It was found that the IHTC between AA7075 and cast iron had values 78.6% higher than that obtained between AA7075 and H13 die steel. Die materials and contact pressures had pronounced effects on the IHTC, suggesting that the IHTC can be used to guide the selection of stamping tool materials and the precise control of processing parameters.
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Full Text Available ... drinking black tea, which reduces iron absorption. Other treatments If you have chronic kidney disease and iron- ... and lifestyle changes to avoid complications. Follow your treatment plan Do not stop taking your prescribed iron ...
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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
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Directory of Open Access Journals (Sweden)
Sarah J Texel
Full Text Available Ceruloplasmin (Cp is an essential ferroxidase that plays important roles in cellular iron trafficking. Previous findings suggest that the proper regulation and subcellular localization of iron are very important in brain cell function and viability. Brain iron dyshomeostasis is observed during normal aging, as well as in several neurodegenerative disorders such as Alzheimer's, Parkinson's and Huntington's diseases, coincident with areas more susceptible to insults. Because of their high metabolic demand and electrical excitability, neurons are particularly vulnerable to ischemic injury and death. We therefore set out to look for abnormalities in the brain of young adult mice that lack Cp. We found that iron levels in the striatum and cerebral cortex of these young animals are significantly lower than wild-type (WT controls. Also mRNA levels of the neurotrophin brain derived neurotrophic factor (BDNF, known for its role in maintenance of cell viability, were decreased in these brain areas. Chelator-mediated depletion of iron in cultured neural cells resulted in reduced BDNF expression by a posttranscriptional mechanism, suggesting a causal link between low brain iron levels and reduced BDNF expression. When the mice were subjected to middle cerebral artery occlusion, a model of focal ischemic stroke, we found increased brain damage in Cp-deficient mice compared to WT controls. Our data indicate that lack of Cp increases neuronal susceptibility to ischemic injury by a mechanism that may involve reduced levels of iron and BDNF.
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Erythrocytic ferroportin reduces intracellular iron accumulation, hemolysis, and malaria risk.
Zhang, De-Liang; Wu, Jian; Shah, Binal N; Greutélaers, Katja C; Ghosh, Manik C; Ollivierre, Hayden; Su, Xin-Zhuan; Thuma, Philip E; Bedu-Addo, George; Mockenhaupt, Frank P; Gordeuk, Victor R; Rouault, Tracey A
2018-03-30
Malaria parasites invade red blood cells (RBCs), consume copious amounts of hemoglobin, and severely disrupt iron regulation in humans. Anemia often accompanies malaria disease; however, iron supplementation therapy inexplicably exacerbates malarial infections. Here we found that the iron exporter ferroportin (FPN) was highly abundant in RBCs, and iron supplementation suppressed its activity. Conditional deletion of the Fpn gene in erythroid cells resulted in accumulation of excess intracellular iron, cellular damage, hemolysis, and increased fatality in malaria-infected mice. In humans, a prevalent FPN mutation, Q248H (glutamine to histidine at position 248), prevented hepcidin-induced degradation of FPN and protected against severe malaria disease. FPN Q248H appears to have been positively selected in African populations in response to the impact of malaria disease. Thus, FPN protects RBCs against oxidative stress and malaria infection. Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.
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Nitrate-dependent iron oxidation limits iron transport in anoxic ocean regions
Scholz, Florian; Löscher, Carolin R.; Fiskal, Annika; Sommer, Stefan; Hensen, Christian; Lomnitz, Ulrike; Wuttig, Kathrin; Göttlicher, Jörg; Kossel, Elke; Steininger, Ralph; Canfield, Donald E.
2016-11-01
Iron is an essential element for life on Earth and limits primary production in large parts of the ocean. Oxygen-free continental margin sediments represent an important source of bioavailable iron to the ocean, yet little of the iron released from the seabed reaches the productive sea surface. Even in the anoxic water of oxygen minimum zones, where iron solubility should be enhanced, most of the iron is rapidly re-precipitated. To constrain the mechanism(s) of iron removal in anoxic ocean regions we explored the sediment and water in the oxygen minimum zone off Peru. During our sampling campaign the water column featured two distinct redox boundaries separating oxic from nitrate-reducing (i.e., nitrogenous) water and nitrogenous from weakly sulfidic water. The sulfidic water mass in contact with the shelf sediment contained elevated iron concentrations >300 nM. At the boundary between sulfidic and nitrogenous conditions, iron concentrations dropped sharply to <20 nM coincident with a maximum in particulate iron concentration. Within the iron gradient, we found an increased expression of the key functional marker gene for nitrate reduction (narG). Part of this upregulation was related to the activity of known iron-oxidizing bacteria. Collectively, our data suggest that iron oxidation and removal is induced by nitrate-reducing microbes, either enzymatically through anaerobic iron oxidation or by providing nitrite for an abiotic reaction. Given the important role that iron plays in nitrogen fixation, photosynthesis and respiration, nitrate-dependent iron oxidation likely represents a key-link between the marine biogeochemical cycles of nitrogen, oxygen and carbon.
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Full Text Available ... normally stores but has used up. Increase your intake of vitamin C to help your body absorb iron. Avoid drinking black tea, which reduces iron absorption. Other treatments If you have chronic kidney disease and iron-deficiency anemia, your doctor may recommend ...
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Repair welding of cast iron coated electrodes
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.
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Hot Spots and Hot Moments of Nitrogen in a Riparian Corridor
Dwivedi, Dipankar; Arora, Bhavna; Steefel, Carl I.; Dafflon, Baptiste; Versteeg, Roelof
2018-01-01
We use 3-D high-resolution reactive transport modeling to investigate whether the spatial distribution of organic-carbon-rich and chemically reduced sediments located in the riparian zone and temporal variability in groundwater flow direction impact the formation and distribution of nitrogen hot spots (regions that exhibit higher reaction rates when compared to other locations nearby) and hot moments (times that exhibit high reaction rates as compared to longer intervening time periods) within the Rifle floodplain in Colorado. Groundwater flows primarily toward the Colorado River from the floodplain but changes direction at times of high river stage. The result is that oxic river water infiltrates the Rifle floodplain during these relatively short-term events. Simulation results indicate that episodic rainfall in the summer season leads to the formation of nitrogen hot moments associated with Colorado River rise and resulting river infiltration into the floodplain. The results further demonstrate that the naturally reduced zones (NRZs) present in sediments of the Rifle floodplain have a higher potential for nitrate removal, approximately 70% greater than non-NRZs for typical hydrological conditions. During river water infiltration, nitrate reduction capacity remains the same within the NRZs, however, these conditions impact non-NRZs to a greater extent (approximately 95% less nitrate removal). Model simulations indicate chemolithoautotrophs are primarily responsible for the removal of nitrate in the Rifle floodplain. These nitrogen hot spots and hot moments are sustained by microbial respiration and the chemolithoautotrophic oxidation of reduced minerals in the riparian zone.
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Preparation and microstructure of hot-pressed YIG
International Nuclear Information System (INIS)
Abdul Halim Shaari; Mansor Hashim; Sidek Haji Abd Aziz
1992-01-01
Bulk magnetic ceramics such as yttrium-iron-garnet (YIG) and nickel-zinc ferrite were prepared by the conventional-firing and hot-press techniques. Pre-sintering and sintering, both in air, were carried out at temperature ≥ 1200 0 C. Initial density and microstructural measurements show that the high density samples with uniform grain size can be readily achieved by hot-pressing. The well-defined microstructures, the high density attained. The agreement of saturation magnetization 4πMs values and the high resistivities indicated that the optimized preparation conditions for conventional firing yielded yttrium-iron-garnet of good quality. Quenched and isochronally annealed, the YIG samples were also found to retain their room-temperature saturation-magnetization and resonance linewidth values after any single heat treatment. However, the electrical resistivity and the effective linewidth clearly exhibited isochronal recovery. A possible model to explain this behaviour and its implications on microwave applications are discussed. Ferrites of the type MFe 2 O 4 where M=Mg, Mn, Co, Fe, Cu, Zn and Cd and of the type Ni1-2xSnxFe 2 O4 have also been prepared and their properties are being studied
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SITUATIONAL CONTROL OF HOT BLAST STOVES GROUP BASED ON DECISION TREE
Directory of Open Access Journals (Sweden)
E. I. Kobysh
2016-09-01
Full Text Available In this paper was developed the control system of group of hot blast stoves, which operates on the basis of the packing heating control subsystem and subsystem of forecasting of modes duration in the hot blast stoves APCS of iron smelting in a blast furnace. With the use of multi-criteria optimization methods, implemented the adjustment of control system conduct, which takes into account the current production situation that has arisen in the course of the heating packing of each hot blast stove group. Developed a situation recognition algorithm and the choice of scenarios of control based on a decision tree.
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The Influence of Hot-Rolled Temperature on Plasma Nitriding Behavior of Iron-Based Alloys
El-Hossary, F. M.; Khalil, S. M.; Lotfy, Kh.; Kassem, M. A.
2009-07-01
Experiments were performed with an aim of studying the effect of hot-rolled temperature (600 and 900°C) on radio frequency (rf) plasma nitriding of Fe93Ni4Zr3 alloy. Nitriding was carried out for 10 min in a nitrogen atmosphere at a base pressure of 10-2 mbarr. Different continuous plasma processing powers of 300-550 W in steps 50 W or less were applied. Nitrided hot-rolled specimens were characterized by optical microscopy (OM), X-ray diffraction (XRD) and microhardness measurements. The results reveal that the surface of hot-rolled rf plasma nitrided specimens at 600°C is characterized with a fine microstructure as a result of the high nitrogen solubility and diffusivity. Moreover, the hot-rolled treated samples at 600°C exhibit higher microhardness value than the associated values of hot-rolled treated samples at 900°C. The enhancement of microhardness is due to precipitation and predominance of new phases ( γ and ɛ phases). Mainly, this conclusion has been attributed to the high defect densities and small grain sizes of the samples hot-rolled at 600°C. Generally, the refinement of grain size plays a dramatic role in improvement of mechanical properties of tested samples.
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Hot gas metallicity and the history of supernova activity in elliptical galaxies
International Nuclear Information System (INIS)
Loewenstein, M.; Mathews, W.G.
1991-01-01
Calculations of the dynamical evolution of the hot interstellar medium (ISM) in a massive elliptical galaxy are described, with a variety of past variations of the SN rate being assumed. The investigation focuses on iron enrichment in the ISM. The equivalent widths of the 6.7-keV iron line are calculated as a function of redshift and of galactic projected radius. The present-day interstellar gas in elliptical galaxies contains a fossil record of past SN activity that can be determined from measurements of iron line equivalent widths at several projected radii in the galaxy. It is proposed that the ISM iron abundance is likely to be quite inhomogeneous. The hydrogen-free ejecta of type Ia SN also result in pronounced ISM abundance inhomogeneities that probably eventually cool and move in pressure equilibrium with the local ISM flow velocity. The 6.7-keV iron line emission is greater if the iron is confined to ionized regions of pure iron. 25 refs
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Use of radionuclides in the study of iron metabolism in iron deficient states
International Nuclear Information System (INIS)
Anatkov, A.; Karakostov, K.; Iliev, Z.; Dimitrov, L.
1977-01-01
A study of erythropoiesis in iron deficient anemias by simultaneous labelling with the radionuclides iron 59 and chromium 51 revealed accelerated iron circuit, higher percentage of daily hemolysis, severely reduced or even absent labile reserves, decreased volume of packed red cells with no decrease of blood volume. Adequate iron 59 utilization was observed after administration of large doses of iron (500 mg) in the treatment of iron deficient anemias. (author)
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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.
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Cast iron - a predictable material
Directory of Open Access Journals (Sweden)
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
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THE INFLUENCE OF PRE-HEAT TREATMENT ON WHITE CAST IRONS PLASTICITY
Directory of Open Access Journals (Sweden)
T. M. Myronova
2013-11-01
Full Text Available Purpose. The development of heat treatment modes of white cast irons for structure changes in their eutectic constituent, namely in disturbing the monolithic structure of ledeburite colonies cementite structure and eutectic net continuity. Also the mentioned heat treatment modes are targeted to the eutectic net shift for the most suitable position from the point of plastic deforming. Methodology. The hypoeutectic white cast irons with 2.92…3.35 % carbon content and additionally alloyed by 3.18 % vanadium have been used as the research materials. The mentioned alloys have been pre-heat treated and hot twist tested. Findings. The research results showed that the carbide net breaking by plastic deforming leads to cast irons mechanical properties increasing but has difficulties in implementation due to the white cast irons low plasticity. The influence of different pre-heat treatment modes on structure and plasticity of white hypoeutectic cast irons have been investigated. They include the isotherm soaking under the different temperatures as well as multiply soakings and thermo-cycling. The influence of eutectic level, as well as pre heat treatment modes on different composition white cast irons hot plasticity have been investigated. Originality. It was determined that the heat treatment, which leads to double α→γ recrystallization under 860 – 950 °С and reperlitization under 720-680 °С results in significant increase of plasticity, as well as in un-alloyed and alloyed by vanadium white cast irons. It takes place due to carbide matrix phase separation in ledeburite colonies by new phase boundaries forming especially due to carbide transformations under vanadium alloying. Practical value. The implementation of pre-heat treatment with phase recrystallization resulted in hypoeutectic white cast irons plasticity increasing. The obtained level of cast iron plasticity corresponds to the one of carbide class steels, which ensures the successful
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Thanner, S; Gutzwiller, A
2018-02-01
The effects of the recommended dose of 200 mg iron and of half that dose injected on the first day of life on health, iron status and performance during the 4 week suckling period were studied in 2'123 piglets. All piglets received creep feed and soil which was supplemented with 14 g iron per kg. Neither mortality nor the prevalence of arthritis, meningitis and foot abscess (each disease affecting about 1% of the piglets) differed between the two groups. The low dose of 100 mg iron decreased blood haemoglobin concentration at weaning (110 ± 19 vs.120 ± 15 g/l), but did not affect growth rate.
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Cooking Chicken Breast Reduces Dialyzable Iron Resulting from Digestion of Muscle Proteins
Gokhale, Aditya S.; Mahoney, Raymond R.
2014-01-01
The purpose of this research was to study the effect of cooking chicken breast on the production of dialyzable iron (an in vitro indicator of bioavailable iron) from added ferric iron. Chicken breast muscle was cooked by boiling, baking, sautéing, or deep-frying. Cooked samples were mixed with ferric iron and either extracted with acid or digested with pepsin and pancreatin. Total and ferrous dialyzable iron was measured after extraction or digestion and compared to raw chicken samples. For u...
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Obesity alters adipose tissue macrophage iron content and tissue iron distribution.
Orr, Jeb S; Kennedy, Arion; Anderson-Baucum, Emily K; Webb, Corey D; Fordahl, Steve C; Erikson, Keith M; Zhang, Yaofang; Etzerodt, Anders; Moestrup, Søren K; Hasty, Alyssa H
2014-02-01
Adipose tissue (AT) expansion is accompanied by the infiltration and accumulation of AT macrophages (ATMs), as well as a shift in ATM polarization. Several studies have implicated recruited M1 ATMs in the metabolic consequences of obesity; however, little is known regarding the role of alternatively activated resident M2 ATMs in AT homeostasis or how their function is altered in obesity. Herein, we report the discovery of a population of alternatively activated ATMs with elevated cellular iron content and an iron-recycling gene expression profile. These iron-rich ATMs are referred to as MFe(hi), and the remaining ATMs are referred to as MFe(lo). In lean mice, ~25% of the ATMs are MFe(hi); this percentage decreases in obesity owing to the recruitment of MFe(lo) macrophages. Similar to MFe(lo) cells, MFe(hi) ATMs undergo an inflammatory shift in obesity. In vivo, obesity reduces the iron content of MFe(hi) ATMs and the gene expression of iron importers as well as the iron exporter, ferroportin, suggesting an impaired ability to handle iron. In vitro, exposure of primary peritoneal macrophages to saturated fatty acids also alters iron metabolism gene expression. Finally, the impaired MFe(hi) iron handling coincides with adipocyte iron overload in obese mice. In conclusion, in obesity, iron distribution is altered both at the cellular and tissue levels, with AT playing a predominant role in this change. An increased availability of fatty acids during obesity may contribute to the observed changes in MFe(hi) ATM phenotype and their reduced capacity to handle iron.
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REDUCING ARSENIC LEVELS IN DRINKING WATER DURING IRON REMOVAL PROCESSES
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...
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Production of iron from metallurgical waste
Hendrickson, David W; Iwasaki, Iwao
2013-09-17
A method of recovering metallic iron from iron-bearing metallurgical waste in steelmaking comprising steps of providing an iron-bearing metallurgical waste containing more than 55% by weight FeO and FeO equivalent and a particle size of at least 80% less than 10 mesh, mixing the iron-bearing metallurgical waste with a carbonaceous material to form a reducible mixture where the carbonaceous material is between 80 and 110% of the stoichiometric amount needed to reduce the iron-bearing waste to metallic iron, and as needed additions to provide a silica content between 0.8 and 8% by weight and a ratio of CaO/SiO.sub.2 between 1.4 and 1.8, forming agglomerates of the reducible mixture over a hearth material layer to protect the hearth, heating the agglomerates to a higher temperature above the melting point of iron to form nodules of metallic iron and slag material from the agglomerates by melting.
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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.
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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.
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Energy Technology Data Exchange (ETDEWEB)
Borok, B A; Kel' tsev, V V
1973-01-01
In a series of laboratory experiments, natural gas containing 98.7% methane and 1.3% nitrogen was passed through a tube packed with particles of a reduced material containing 62% iron. At 900/sup 0/C and 25 vol/vol/hr space velocity, conversion was 99%, and the exit gas contained 98.4% hydrogen. The solid product, called sooty iron, obtained in the experiments contained 20 to 60% carbon; the volume of sponge iron treated with methane at 900/sup 0/C increased when the carbon content reached 30%. Runs with natural gas at a range of temperatures and constant space velocity or at 900/sup 0/C and increasing space velocity, runs with propane feed instead of methane, and the activity of the iron-carbon complex are discussed.
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Microbiology of Kamchatka Peninsula Hot Springs
Bonch-Osmolovsk, E.
2005-12-01
Hot springs of Uzon Caldera, Geyser Valley, Moutnovsky Volcano (Kamchatka Peninsula) served as the sources of isolation of numerous thermophilic prokaryotes, many of them representing new taxa. Among new isolates there were hyperthermophilic archaea - neutrophilic or acidophilic anaerobic organotrophs, able to use a wide range of polymeric organic substrates. Bacterial isolates were in majority represented by moderate thermophiles - organotrophs and lithoautotrophs. Latter group consisted of anaerobes oxidizing molecular hydrogen in the course of sulfate, sulfur or iron reduction, and of anaerobic CO-oxidizing, hydrogen-producing bacteria. Some of new isolates represented deep phylogenetic lineages in Bacteria domain. Microbial activity in Kamchatka hot springs was studied by means of radioisotopic tracing. The rates of methanogenesis, acetogenesis, inorganic carbon assimilation, acetate oxidation were determined in three different hot springs with pH ranging from 3.0 to 8.5 and water temeperature being in the range from 55 to 85oC. The results indicated the presence and activity of novel metabolic groups of thermophilic prokaryotes that so far have not been known in laboratory cultures.
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Iron colloids reduce the bioavailability of phosphorus to the green alga Raphidocelis subcapitata.
Baken, Stijn; Nawara, Sophie; Van Moorleghem, Christoff; Smolders, Erik
2014-08-01
Phosphorus (P) is a limiting nutrient in many aquatic systems. The bioavailability of P in natural waters strongly depends on its speciation. In this study, structural properties of iron colloids were determined and related to their effect on P sorption and P bioavailability. The freshwater green alga Raphidocelis subcapitata was exposed to media spiked with radiolabelled (33)PO4, and the uptake of (33)P was monitored for 1 h. The media contained various concentrations of synthetic iron colloids with a size between 10 kDa and 0.45 μm. The iron colloids were stabilised by natural organic matter. EXAFS spectroscopy showed that these colloids predominantly consisted of ferrihydrite with small amounts of organically complexed Fe. In colloid-free treatments, the P uptake flux by the algae obeyed Michaelis-Menten kinetics. In the presence of iron colloids at 9 or 90 μM Fe, corresponding to molar P:Fe ratios between 0.02 and 0.17, the truly dissolved P (<10 kDa) was between 4 and 60% of the total dissolved P (<0.45 μm). These colloids reduced the P uptake flux by R. subcapitata compared to colloid-free treatments at the same total dissolved P concentration. However, the P uptake flux from colloid containing solutions equalled that from colloid-free ones when expressed as truly dissolved P. This demonstrates that colloidal P did not contribute to the P uptake flux. It is concluded that, on the short term, phosphate adsorbed to ferrihydrite colloids is not available to the green alga R. subcapitata. Copyright © 2014 Elsevier Ltd. All rights reserved.
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Energy Technology Data Exchange (ETDEWEB)
Weil, Mirco, E-mail: m.weil@ect.de [ECT Oekotoxikologie GmbH, Böttgerstrasse 2-14, 65439 Flörsheim (Germany); Meißner, Tobias, E-mail: tmeiss@gmx.net [Fraunhofer Institute for Ceramic Technologies and Systems, Winterbergstrasse 28, 01277 Dresden (Germany); Springer, Armin, E-mail: armin.springer@nano.tu-dresden.de [Dresden University of Technology, Budapesterstrasse 27, 01069 Dresden (Germany); Bundschuh, Mirco, E-mail: mirco.bundschuh@slu.se [Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Uppsala (Sweden); Institute for Environmental Sciences, University of Koblenz-Landau, Forststrasse 7, 76829 Landau (Germany); Hübler, Lydia, E-mail: lydia.huebler@gmail.com [ECT Oekotoxikologie GmbH, Böttgerstrasse 2-14, 65439 Flörsheim (Germany); Schulz, Ralf, E-mail: schulz@uni-landau.de [Institute for Environmental Sciences, University of Koblenz-Landau, Forststrasse 7, 76829 Landau (Germany); Duis, Karen, E-mail: k-duis@ect.de [ECT Oekotoxikologie GmbH, Böttgerstrasse 2-14, 65439 Flörsheim (Germany)
2016-12-15
Highlights: • Effects on growth, reproduction and survival at ≥12.5 mg of oxidized Carbo-Iron/L were studied. • Carbo-Iron significantly increases sensitivity of offspring from exposed amphipods. • Toxicity is most likely mediated by an impaired uptake of nutrients and energy. - Abstract: For in situ remediation of groundwater contaminated by halogenated hydrocarbons Carbo-Iron{sup ®}, a composite of microscale activated carbon and nano Fe{sup 0}, was developed. Against the background of intended release of Carbo-Iron into the environment in concentrations in the g/L-range, potential ecotoxicological consequences were evaluated in the present study. The nano Fei{sup 0} in Carbo-Iron acts as reducing agent and is oxidized in aqueous systems by chlorinated solvents, groundwater constituents (e.g. dissolved oxygen) and anaerobic corrosion. As Carbo-Iron is generally oxidized rapidly after application into the environment, the oxidized state is environmentally most relevant, and Carbo-Iron was used in its oxidized form in the ecotoxicological tests. The amphipod Hyalella azteca was selected as a surrogate test species for functionally important groundwater crustaceans. Effects of Carbo-Iron on H. azteca were determined in a 10-d acute test, a 7-d feeding activity test and a 42-d chronic test. Additionally, a 56-d life cycle test was performed with a modified design to further evaluate effects of Carbo-Iron on adult H. azteca and their offspring. The size of Carbo-Iron particles in stock and test suspensions was determined via dynamic light scattering. Potential uptake of particles into test organisms was investigated using transmission and scanning electron microscopy. At the termination of the feeding and acute toxicity test (i.e. after 7 and 10 d of exposure, respectively), Carbo-Iron had a significant effect on the weight, length and feeding rate of H. azteca at the highest test concentration of 100 mg/L. While an uptake of Carbo-Iron into the gut was
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Bae, Yeunook; Kim, Dooil; Cho, Hyun-Hee; Singhal, Naresh; Park, Jae-Woo
2012-12-01
In this research, we conducted trichloroethylene (TCE) reduction in a column filled with iron and iron-reducing bacteria (IRB) and developed a mathematical model to investigate the critical reactions between active species in iron/IRB/contaminant systems. The formation of ferrous iron (Fe(II)) in this system with IRB and zero-valent iron (ZVI, Fe(0)) coated with a ferric iron (Fe(III)) crust significantly affected TCE reduction and IRB respiration in various ways. This study presents a new framework for transformation property and reducing ability of both dissolved (Fe(II)(dissolved)) and solid form ferrous iron (Fe(II)(solid)). Results showed that TCE reduction was strongly depressed by Fe(II)(solid) rather than by other inhibitors (e.g., Fe(III) and lactate), suggesting that Fe(II)(solid) might reduce IRB activation due to attachment to IRB cells. Newly exposed Fe(0) from the released Fe(II)(dissolved) was a strong contributor to TCE reduction compared to Fe(II)(solid). In addition, our research confirmed that less Fe(II)(solid) production strongly supported long-term TCE reduction because it may create an easier TCE approach to Fe(0) or increase IRB growth. Our findings will aid the understanding of the contributions of iron media (e.g., Fe(II)(solid), Fe(II)(dissolved), Fe(III), and Fe(0)) to IRB for decontamination in natural groundwater systems. Copyright © 2012 Elsevier Ltd. All rights reserved.
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Shammo, Jamile M; Komrokji, Rami S
2018-06-14
Patients with myelodysplastic syndromes (MDS) are at increased risk of iron overload due to ineffective erythropoiesis and chronic transfusion therapy. The clinical consequences of iron overload include cardiac and/or hepatic failure, endocrinopathies, and infection risk. Areas covered: Iron chelation therapy (ICT) can help remove excess iron and ultimately reduce the clinical consequences of iron overload. The authors reviewed recent (last five years) English-language articles from PubMed on the topic of iron overload-related complications and the use of ICT (primarily deferasirox) to improve outcomes in patients with MDS. Expert Commentary: While a benefit of ICT has been more firmly established in other transfusion-dependent conditions such as thalassemia, its role in reducing iron overload in MDS remains controversial due to the lack of prospective controlled data demonstrating a survival benefit. Orally administered chelation agents (e.g., deferasirox), are now available, and observational and/or retrospective data support a survival benefit of using ICT in MDS. The placebo-controlled TELESTO trial (NCT00940602) is currently examining the use of deferasirox in MDS patients with iron overload, and is evaluating specifically whether use of ICT to alleviate iron overload can also reduce iron overload-related complications in MDS and improve survival.
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Study on Damage Mechanism of Ductile Cast Iron Cooling Stave
Wang, Cui; Zhang, Jianliang; Zuo, Haibin; Dai, Bing
The damage mechanism of ductile cast iron cooling stave applied to No.4 blast furnace of Guofeng steel was analyzed through damage investigation in details, the damage causes: high-temperature gas flow erosion, wear of burden, high-temperature ablation, carburizing damage, improper operation on blast furnace, etc. were given out both in macroscopic and microscopic views. It can be obtained from metallographic diagrams that the diameter of graphite nodules increases, the number per unit area reduces, and roundness declines, successively, from cold to hot surface, which are not conducive to stave longevity. In summary, the material for staves manufacture should be better in comprehensive mechanical properties to prolong the service life, thus making blast furnace long campaign.
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Microbial reduction of iron ore
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.
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Dynamics of Phenol Degrading—Iron Reducing Bacteria in Intensive Rice Croopping System
Institute of Scientific and Technical Information of China (English)
LUWENJING; W.REICHARDT; 等
2001-01-01
Field and greenhouse experiments were conducted to investigate the effects of cropping season,nitrogen fertilizer input and aerated fallow o the dynamics of phenol degrading-iron reducing bacteria(PD-IRB)in tropical irrigated rice(Oryza sativa L.)systems,The PD-IRB population density was monitored at different stages of rice growth in two cropping seasons (dry and early wet) in a continuous annual triple rice cropping system under irrigated condition,In this system,the high nitrogen input (195 and 135 kg N ha-1 in dry and ewt seasons ,respectively)plots and control plots receiving no N fertilizer were compared to investigate the effect of nitrogen rate on population size.The phenol degrading-iron reducing bacteria (PD-IRB)were abundant in soils under croppin systems of tropical irrigated rice.However,density of the bacterial populations varied with rice growth stages.Cropping seasons,rhizosphere,and aerated fallow could affect the dynamics of PD-IRB,In the field trial,viable counts of PD-IRB in the topsoil layer(15 cm)ranged between 102 and 108 cells per gram of dry soil.A steep increase in viable counts during the second half of the cropping season suggested that the population density of PD-IRB increased ant advanced crop-growth stages.Population growth of PD-IRB was accelerated during the dry season compared to the wet season,In the greenhouse experiment,the adjacent aerated fallow revealed 1-2 orders of magnitude higher in most probable number(MPN)of PD-IRB than the wet fallow treated plots.As a prominent group of Fe reducing bacteria,PD-IRB predominated in the rhizosphere of rice,since maximum MPN of PD-IRB (2.62×108 g-1 soil) was found in rhizosphere soil.Mineral N fertilizer rates showed no significant effect on PD-IRB population density.
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Weaver, M.; Benner, S.; Fendorf, S.; Sampson, M.; Leng, M.
2007-12-01
Atmospheric concentrations of methane have been steadily increasing over the last 100 years, which has given rise to research of wetland rice fields, recently identified as a major anthropomorphic source of methane. Establishment of experimental soil pots, cultivating an aromatic early variety rice strain in the Kean Svay District of Cambodia, have recently been carried out to evaluate methods to minimize methane release by promoting redox buffering by iron oxides. In the first series of experiments, iron oxides were added to the soils and the rate of change in reducing conditions and methanogenesis onset was monitored. In the second series of experiments, plots are subject to periodic drying cycles to promote rejuvenation of buffering iron oxides. Initial results indicate a delay in the onset of methanogenesis, and overall methane generation, in plots where initial iron oxides concentrations are elevated.
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Full Text Available ... C to help your body absorb iron. Avoid drinking black tea, which reduces iron absorption. Other treatments ... improve health through research and scientific discovery. Improving health with current research Learn about the following ways ...
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Tropical forest soil microbial communities couple iron and carbon biogeochemistry
Energy Technology Data Exchange (ETDEWEB)
Dubinsky, E.A.; Silver, W.L.; Firestone, M.K.
2009-10-15
We report that iron-reducing bacteria are primary mediators of anaerobic carbon oxidation in upland tropical soils spanning a rainfall gradient (3500 - 5000 mm yr-1) in northeast Puerto Rico. The abundant rainfall and high net primary productivity of these tropical forests provide optimal soil habitat for iron-reducing and iron-oxidizing bacteria. Spatially and temporally dynamic redox conditions make iron-transforming microbial communities central to the belowground carbon cycle in these wet tropical forests. The exceedingly high abundance of iron-reducing bacteria (up to 1.2 x 10{sup 9} cells per gram soil) indicated that they possess extensive metabolic capacity to catalyze the reduction of iron minerals. In soils from the higher rainfall sites, measured rates of ferric iron reduction could account for up to 44 % of organic carbon oxidation. Iron reducers appeared to compete with methanogens when labile carbon availability was limited. We found large numbers of bacteria that oxidize reduced iron at sites with high rates of iron reduction and large numbers of iron-reducers. the coexistence of large populations of ironreducing and iron-oxidizing bacteria is evidence for rapid iron cycling between its reduced and oxidized states, and suggests that mutualistic interactions among these bacteria ultimately fuel organic carbon oxidation and inhibit CH4 production in these upland tropical forests.
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Treatment of acid rock drainage using a sulfate-reducing bioreactor with zero-valent iron
Energy Technology Data Exchange (ETDEWEB)
Ayala-Parra, Pedro; Sierra-Alvarez, Reyes; Field, James A., E-mail: jimfield@email.arizona.edu
2016-05-05
Highlights: • Electron donor from zero-valent iron (ZVI) drives sulfate reduction to sulfide. • Sulfide converts soluble heavy metals into sulfide minerals. • Excess sulfide is sequestered by iron preventing discharge. • Corrosion of ZVI consumes acidity in acid rock drainage. • ZVI as reactive material outlasted limestone in removing heavy metals. - Abstract: This study assessed the bioremediation of acid rock drainage (ARD) in flow-through columns testing zero-valent iron (ZVI) for the first time as the sole exogenous electron donor to drive sulfate-reducing bacteria in permeable reactive barriers. Columns containing ZVI, limestone or a mixture of both materials were inoculated with an anaerobic mixed culture and fed a synthetic ARD containing sulfuric acid and heavy metals (initially copper, and later also cadmium and lead). ZVI significantly enhanced sulfate reduction and the heavy metals were extensively removed (>99.7%). Solid-phase analyses showed that heavy metals were precipitated with biogenic sulfide in the columns packed with ZVI. Excess sulfide was sequestered by iron, preventing the discharge of dissolved sulfide. In the absence of ZVI, heavy metals were also significantly removed (>99.8%) due to precipitation with hydroxide and carbonate ions released from the limestone. Vertical-profiles of heavy metals in the columns packing, at the end of the experiment, demonstrated that the ZVI columns still had excess capacity to remove heavy metals, while the capacity of the limestone control column was approaching saturation. The ZVI provided conditions that enhanced sulfate reduction and generated alkalinity. Collectively, the results demonstrate an innovative passive ARD remediation process using ZVI as sole electron-donor.
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Treatment of acid rock drainage using a sulfate-reducing bioreactor with zero-valent iron
International Nuclear Information System (INIS)
Ayala-Parra, Pedro; Sierra-Alvarez, Reyes; Field, James A.
2016-01-01
Highlights: • Electron donor from zero-valent iron (ZVI) drives sulfate reduction to sulfide. • Sulfide converts soluble heavy metals into sulfide minerals. • Excess sulfide is sequestered by iron preventing discharge. • Corrosion of ZVI consumes acidity in acid rock drainage. • ZVI as reactive material outlasted limestone in removing heavy metals. - Abstract: This study assessed the bioremediation of acid rock drainage (ARD) in flow-through columns testing zero-valent iron (ZVI) for the first time as the sole exogenous electron donor to drive sulfate-reducing bacteria in permeable reactive barriers. Columns containing ZVI, limestone or a mixture of both materials were inoculated with an anaerobic mixed culture and fed a synthetic ARD containing sulfuric acid and heavy metals (initially copper, and later also cadmium and lead). ZVI significantly enhanced sulfate reduction and the heavy metals were extensively removed (>99.7%). Solid-phase analyses showed that heavy metals were precipitated with biogenic sulfide in the columns packed with ZVI. Excess sulfide was sequestered by iron, preventing the discharge of dissolved sulfide. In the absence of ZVI, heavy metals were also significantly removed (>99.8%) due to precipitation with hydroxide and carbonate ions released from the limestone. Vertical-profiles of heavy metals in the columns packing, at the end of the experiment, demonstrated that the ZVI columns still had excess capacity to remove heavy metals, while the capacity of the limestone control column was approaching saturation. The ZVI provided conditions that enhanced sulfate reduction and generated alkalinity. Collectively, the results demonstrate an innovative passive ARD remediation process using ZVI as sole electron-donor.
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Assessing the Role of Iron Sulfides in the Long Term Sequestration of U by Sulfate Reducing Bacteria
Energy Technology Data Exchange (ETDEWEB)
Rittman, Bruce; Zhou, Chen; Vannela, Raveender
2013-12-31
This four-year project’s overarching aim was to identify the role of biogenic and synthetic iron-sulfide minerals in the long-term sequestration of reduced U(IV) formed under sulfate-reducing conditions when subjected to re-oxidizing conditions. As stated in this final report, significant progress was achieved through the collaborative research effort conducted at Arizona State University (ASU) and the University of Michigan (UM).
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Full Text Available ... an MCV of less than 80 femtoliters (fL). Prevention strategies If you have certain risk factors , such ... drinking black tea, which reduces iron absorption. Other treatments If you have chronic kidney disease and iron- ...
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The Effects of Iron Filling On Some Mechanical and Physical ...
African Journals Online (AJOL)
acer
sawdust of particle size 1.18mm and iron fillings of size 300µm, 20g binder (urea formaldehyde) concentration, hot ... The water absorption and thickness swell test results showed that the .... of this type of magnetic material include: easier.
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Lili Zhang; Xinxin Yu; Hongrui Hu; Yang Li; Mingzai Wu; Zhongzhu Wang; Guang Li; Zhaoqi Sun; Changle Chen
2015-01-01
Iron oxides/reduced graphene oxide composites were synthesized by facile thermochemical reactions of graphite oxide and FeSO4?7H2O. By adjusting reaction temperature, ?-Fe2O3/reduced graphene oxide and Fe3O4/reduced graphene oxide composites can be obtained conveniently. Graphene oxide and reduced graphene oxide sheets were demonstrated to regulate the phase transition from ?-Fe2O3 to Fe3O4 via ?-Fe2O3, which was reported for the first time. The hydroxyl groups attached on the graphene oxide ...
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Minocycline Attenuates Iron-Induced Brain Injury.
Zhao, Fan; Xi, Guohua; Liu, Wenqaun; Keep, Richard F; Hua, Ya
2016-01-01
Iron plays an important role in brain injury after intracerebral hemorrhage (ICH). Our previous study found minocycline reduces iron overload after ICH. The present study examined the effects of minocycline on the subacute brain injury induced by iron. Rats had an intracaudate injection of 50 μl of saline, iron, or iron + minocycline. All the animals were euthanized at day 3. Rat brains were used for immunohistochemistry (n = 5-6 per each group) and Western blotting assay (n = 4). Brain swelling, blood-brain barrier (BBB) disruption, and iron-handling proteins were measured. We found that intracerebral injection of iron resulted in brain swelling, BBB disruption, and brain iron-handling protein upregulation (p minocycline with iron significantly reduced iron-induced brain swelling (n = 5, p Minocycline significantly decreased albumin protein levels in the ipsilateral basal ganglia (p minocycline co-injected animals. In conclusion, the present study suggests that minocycline attenuates brain swelling and BBB disruption via an iron-chelation mechanism.
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International Nuclear Information System (INIS)
Thakur, Suman; Karak, Niranjan
2014-01-01
An environmentally friendly effective technique was demonstrated to prepare iron oxide/reduced graphene oxide nanohybrid (IO/RGO) at room temperature by using banana peel ash aqueous extract as the base source and Colocasia esculenta leaves aqueous extract as the reducing agent. The nanohybrid was characterized by Fourier transform infrared spectroscopy, X-ray diffractometry, transmission electron microscopy, vibrating sample magnetometry, Raman spectroscopy and thermal studies. The results indicated the decoration of superparamagnetic IO nanoparticles on the surface of the RGO. Both organic and inorganic pollutants were effectively removed from the contaminated water (for Pb 2+ and Cd 2+ within 10 min, whereas for tetrabromobisphenol A within 30 min) by IO/RGO. The study revealed that adsorption followed pseudo-second order kinetics and isotherms were well described by the Langmuir model in all the cases. The thermodynamics parameters (ΔG°, ΔS° and ΔH°) were calculated from the temperature dependent isotherms and indicated that the adsorptions were endothermic and spontaneous. - Highlights: • Eco-friendly one step preparation of iron oxide/reduced graphene oxide nanohybrid. • The nanohybrid has excellent pollutants removal capacity from contaminated water. • Superparamagnetic iron oxide nanoparticles help in easy recycle. • The adsorption processes of pollutants are endothermic and spontaneous
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Energy Technology Data Exchange (ETDEWEB)
Thakur, Suman; Karak, Niranjan, E-mail: karakniranjan@yahoo.com
2014-04-01
An environmentally friendly effective technique was demonstrated to prepare iron oxide/reduced graphene oxide nanohybrid (IO/RGO) at room temperature by using banana peel ash aqueous extract as the base source and Colocasia esculenta leaves aqueous extract as the reducing agent. The nanohybrid was characterized by Fourier transform infrared spectroscopy, X-ray diffractometry, transmission electron microscopy, vibrating sample magnetometry, Raman spectroscopy and thermal studies. The results indicated the decoration of superparamagnetic IO nanoparticles on the surface of the RGO. Both organic and inorganic pollutants were effectively removed from the contaminated water (for Pb{sup 2+} and Cd{sup 2+} within 10 min, whereas for tetrabromobisphenol A within 30 min) by IO/RGO. The study revealed that adsorption followed pseudo-second order kinetics and isotherms were well described by the Langmuir model in all the cases. The thermodynamics parameters (ΔG°, ΔS° and ΔH°) were calculated from the temperature dependent isotherms and indicated that the adsorptions were endothermic and spontaneous. - Highlights: • Eco-friendly one step preparation of iron oxide/reduced graphene oxide nanohybrid. • The nanohybrid has excellent pollutants removal capacity from contaminated water. • Superparamagnetic iron oxide nanoparticles help in easy recycle. • The adsorption processes of pollutants are endothermic and spontaneous.
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Full Text Available ... is blood loss during dialysis. People who have chronic kidney disease also often take other medicines—such as proton ... reduces iron absorption. Other treatments If you have chronic kidney disease and iron-deficiency anemia, your doctor may recommend ...
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Recovery of iron oxide from coal fly ash
Dobbins, Michael S.; Murtha, Marlyn J.
1983-05-31
A high quality iron oxide concentrate, suitable as a feed for blast and electric reduction furnaces is recovered from pulverized coal fly ash. The magnetic portion of the fly ash is separated and treated with a hot strong alkali solution which dissolves most of the silica and alumina in the fly ash, leaving a solid residue and forming a precipitate which is an acid soluble salt of aluminosilicate hydrate. The residue and precipitate are then treated with a strong mineral acid to dissolve the precipitate leaving a solid residue containing at least 90 weight percent iron oxide.
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Software Simulation of Hot Tearing
DEFF Research Database (Denmark)
Andersen, S.; Hansen, P.N.; Hattel, Jesper Henri
1999-01-01
The brittleness of a solidifying alloy in a temperature range near the solidus temperature has been recognised since the fifties as the mechanism responsible for hot tearing. Due to this brittlenes, the metal will crack under even small amounts of strain in that temperature range. We see these hot...... tears in castings close to hot centres, where the level of strain is often too high.Although the hot tearing mechanism is well understood, until now it has been difficult to do much to reduce the hot tearing tendency in a casting. In the seventies, good hot tearing criteria were developed by considering...... the solidification rate and the strain rate of the hot tear prone areas. But, until recently it was only possible to simulate the solidification rate, so that the criteria could not be used effectively.Today, with new software developments, it is possible to also simulate the strain rate in the hot tear prone areas...
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Synergistic effect of iron and intumescent flame retardant on shape-stabilized phase change material
International Nuclear Information System (INIS)
Zhang Ping; Hu Yuan; Song Lei; Lu Hongdian; Wang Jian; Liu Qingqing
2009-01-01
This paper deals with the preparation of paraffin/high density polyethylene (HDPE)/intumescent flame retardant (IFR)/iron as flame retardant shape-stabilized phase change material (FSPCM). The influences of iron for FSPCM on morphology, flammability property, latent heat and thermal conductive property were characterized by scanning electron microscopy (SEM), cone calorimeter, differential scanning calorimetry (DSC) and hot disk thermal constants analyser. It was found that iron could be well dispersed into the composite formed by HDPE and paraffin; the flame retardant efficiency of IFR could be improved by adding iron; the thermal conductivity of FSPCM could be increased due to the high thermal conductivity of iron. At the same time, the possible flame retardant mechanism for paraffin/HDPE/IFR with iron as a FSPCM was proposed
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System and method for producing metallic iron
Englund, David J.; Schlichting, Mark; Meehan, John; Crouch, Jeremiah; Wilson, Logan
2014-07-29
A method of production of metallic iron nodules comprises assembling a hearth furnace having a moveable hearth comprising refractory material and having a conversion zone and a fusion zone, providing a hearth material layer comprising carbonaceous material on the refractory material, providing a layer of reducible material comprising and iron bearing material arranged in discrete portions over at least a portion of the hearth material layer, delivering oxygen gas into the hearth furnace to a ratio of at least 0.8:1 ponds of oxygen to pounds of iron in the reducible material to heat the conversion zone to a temperature sufficient to at least partially reduce the reducible material and to heat the fusion zone to a temperature sufficient to at least partially reduce the reducible material, and heating the reducible material to form one or more metallic iron nodules and slag.
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High Density Radiation Shielding Concretes for Hot Cells of 99mTc Project
International Nuclear Information System (INIS)
Sakr, K.
2006-01-01
High density concrete [more than 3.6 ton/m 3 (3.6x10 3 kg/m 3 )] was prepared to be used as a radiation shielding concrete (RSC) for hot-cells in gel technetium project at inshas to attenuate gamma radiation emitted from radioactive sources. different types of concrete were prepared by mixing local mineral aggregates mainly gravel and ilmenite . iron shots were added to the concrete mixture proportion as partial replacement of heavy aggregates to increase its density. the physical properties of prepared concrete in both plastic and hardened phases were investigated. compressive strength and radiation attenuation of gamma rays were determined. Results showed that ilmenite concrete mixed with iron shots had the highest density suitable to be use as RSC according to the chinese hot cell design requirements. Recommendations to avoid some technical problems of manufacturing radiation shielding concrete were maintained
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Watling, Helen R; Collinson, David M; Corbett, Melissa K; Shiers, Denis W; Kaksonen, Anna H; Watkin, Elizabeth L J
2016-09-01
The application of thermoacidophiles for chalcopyrite (CuFeS2) bioleaching in hot, acidic, saline solution was investigated as a possible process route for rapid Cu extraction. The study comprised a discussion of protective mechanisms employed for the survival and/or adaptation of thermoacidophiles to osmotic stress, a compilation of chloride tolerances for three genera of thermoacidophiles applied in bioleaching and an experimental study of the activities of three species in a saline bioleaching system. The data showed that the oxidation rates of iron(II) and reduced inorganic sulfur compounds (tetrathionate) were reduced in the presence of chloride levels well below chloride concentrations in seawater, limiting the applicability of these microorganisms in the bioleaching of CuFeS2 in saline water. Copyright © 2016. Published by Elsevier Masson SAS.
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Directory of Open Access Journals (Sweden)
Jonghan Kim
Full Text Available Iron-responsive manganese uptake is increased in iron-deficient rats, suggesting that toxicity related to manganese exposure could be modified by iron status. To explore possible interactions, the distribution of intranasally-instilled manganese in control and iron-deficient rat brain was characterized by quantitative image analysis using T1-weighted magnetic resonance imaging (MRI. Manganese accumulation in the brain of iron-deficient rats was doubled after intranasal administration of MnCl(2 for 1- or 3-week. Enhanced manganese level was observed in specific brain regions of iron-deficient rats, including the striatum, hippocampus, and prefrontal cortex. Iron-deficient rats spent reduced time on a standard accelerating rotarod bar before falling and with lower peak speed compared to controls; unexpectedly, these measures of motor function significantly improved in iron-deficient rats intranasally-instilled with MnCl(2. Although tissue dopamine concentrations were similar in the striatum, dopamine transporter (DAT and dopamine receptor D(1 (D1R levels were reduced and dopamine receptor D(2 (D2R levels were increased in manganese-instilled rats, suggesting that manganese-induced changes in post-synaptic dopaminergic signaling contribute to the compensatory effect. Enhanced olfactory manganese uptake during iron deficiency appears to be a programmed "rescue response" with beneficial influence on motor impairment due to low iron status.
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Directory of Open Access Journals (Sweden)
Bayanzay K
2016-08-01
Full Text Available Karim Bayanzay, Lama Alzoebie Department of Hematology, Gulf Medical University, Ajman, United Arab Emirates Abstract: Hypertransfusion regimens for thalassemic patients revolutionized the management of severe thalassemia; transforming a disease which previously led to early infant death into a chronic condition. The devastating effect of the accrued iron from chronic blood transfusions necessitates a more finely tuned approach to limit the complications of the disease, as well as its treatment. A comprehensive approach including carefully tailored transfusion protocol, continuous monitoring and assessment of total body iron levels, and iron chelation are currently the mainstay in treating iron overload. There are also indications for ancillary treatments, such as splenectomy and fetal hemoglobin induction. The main cause of death in iron overload continues to be related to cardiac complications. However, since the widespread use of iron chelation started in the 1970s, there has been a general improvement in survival in these patients. Keywords: hematology, chelators, deferoxamine, deferiserox, deferiprone, liver iron concentration, iron overload, serum ferritin concentration, hepatic iron storage, iron chelation therapy
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Li, Jiang; Wang, Rui; Xiao, Cheng
2014-04-01
Some studies have indicated that the consumption of chilli-containing foods can influence iron absorption and affect serum insulin and glucose concentrations, which may help to alleviate diabetes or prediabetes. The objective of this study was to explore the relationship between chilli food habits with iron status and insulin resistance in the Chinese population. Fasting blood samples, anthropometric data, and chilli food habit data collected from 8433 adults (aged 18 to 99), in 2009, as part of the China Health and Nutrition Survey, a large-scale longitudinal, household-based survey in China. Chilli food habits were assessed using chilli food eating frequencies (no eating, sometimes eating, often eating, and usually eating) and chilli food types (a little bit hot, moderately hot, and very hot). Fasting serum ferritin, insulin, and fasting plasma glucose were also measured. The homeostasis model assessment of insulin resistance (HOMA-IR) was used to estimate insulin resistance. Compared with the chilli-eating group, the no eating group had higher HOMA-IR levels for both men and women (Pfood types. However, there was no significant difference in the ferritin level and HOMA-IR components for different chilli food eating frequencies in both sex groups. Chilli food habits, especially the different hotness levels of chilli food, were associated with iron status and insulin resistance in the Chinese population. Additional studies are needed to elucidate mechanisms of action and to establish causal inference.
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Method for enhancing the desulfurization of hot coal gas in a fluid-bed coal gasifier
Grindley, Thomas
1989-01-01
A process and apparatus for providing additional desulfurization of the hot gas produced in a fluid-bed coal gasifier, within the gasifier. A fluid-bed of iron oxide is located inside the gasifier above the gasification bed in a fluid-bed coal gasifier in which in-bed desulfurization by lime/limestone takes place. The product gases leave the gasification bed typically at 1600.degree. to 1800.degree. F. and are partially quenched with water to 1000.degree. to 1200.degree. F. before entering the iron oxide bed. The iron oxide bed provides additional desulfurization beyond that provided by the lime/limestone.
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Iron crud supply device to reactor coolant
International Nuclear Information System (INIS)
Baba, Takao.
1993-01-01
In a device for supplying iron cruds into reactor coolants in a BWR type power plant, a system in which feed water containing iron cruds is supplied to the reactor coolants after once passing through an ion exchange resin is disposed. As a result, iron cruds having characteristics similar with those of naturally occurring iron cruds in the plant are obtained and they react with ionic radioactivity, to form composite oxides. Then, iron cruds having high performance of being secured to the surface of a fuel cladding tube can be supplied to the reactor coolants, thereby enabling to greatly reduce the density of reactor water ionic radioactivity. In its turn, dose rate on the surface of pipelines can be reduced, thereby enabling to reduce operators' radiation exposure dose in the plant. Further, contamination of a condensate desalting device due to iron cruds can be prevented, and further, the density of the iron cruds supplied can easily be controlled. (N.H.)
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Iron deficiency among blood donors
DEFF Research Database (Denmark)
Rigas, A S; Pedersen, O B; Magnussen, K
2017-01-01
Blood components collected from blood donors are an invaluable part of modern-day medicine. A healthy blood donor population is therefore of paramount importance. The results from the Danish Blood Donor Study (DBDS) indicate that gender, number of previous donations, time since last donation...... and menopausal status are the strongest predictors of iron deficiency. Only little information on the health effects of iron deficiency in blood donors exits. Possibly, after a standard full blood donation, a temporarily reduced physical performance for women is observed. However, iron deficiency among blood...... donors is not reflected in a reduced self-perceived mental and physical health. In general, the high proportion of iron-deficient donors can be alleviated either by extending the inter-donation intervals or by guided iron supplementation. The experience from Copenhagen, the Capital Region of Denmark...
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Eghbali, Aziz; Kazemi, Hamideh; Taherahmadi, Hassan; Ghandi, Yazdan; Rafiei, Mohammad; Bagheri, Bahador
2017-12-01
Cardiomyopathy due to iron overload can be fatal in patients with thalassemia major. Calcium channel blockers seem to be effective to reduce iron loading. Our goal was to study effects of amlodipine addition to chelators on iron loading in patients with thalassemia major. This randomized, controlled, and single-center trial was performed on 56 patients with thalassemia major. Patients were randomized 1:1 to combined group (iron chelator plus amlodipine) or control group (iron chelator) for 1 year. Iron content was measured by magnetic resonance imaging; heart T2*, and liver T2*. Serum ferritin was also measured. After 12 months of treatment, myocardial T2* values had significant improvement in combined group (21.9 ± 8.0 ms to 24.5 ± 7.6 ms; P < .05); Difference between two groups was significant (P = .02). Combined treatment had no effect on hepatic T2* value (9.6 ± 2.8 ms to 9.5 ± 3.6 ms); difference between two groups was not significant (P = .2). In addition, a significant reduction was seen in serum ferritin levels in two groups. Mild gastrointestinal upset was the most common untoward effect. Addition of amlodipine to iron chelators has beneficial effects for reduction of iron loading in patients with thalassemia major. This combination therapy seems safe. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
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Directory of Open Access Journals (Sweden)
Guanghui Li
2016-11-01
Full Text Available Recovery of iron from iron-rich diasporic bauxite ore via reductive roasting followed by magnetic separation has been explored recently. However, the efficiency of alumina extraction in the non-magnetic materials is absent. In this paper, a further study on the digestion of alumina by the Bayer process from non-magnetic material obtained after magnetic separation of reduced iron-rich diasporic bauxite with sodium salts was investigated. The results indicate that the addition of sodium salts can destroy the original occurrences of iron-, aluminum- and silicon-containing minerals of bauxite ore during reductive roasting. Meanwhile, the reactions of sodium salts with complex aluminum- and silicon-bearing phases generate diaoyudaoite and sodium aluminosilicate. The separation of iron via reductive roasting of bauxite ore with sodium salts followed by magnetic separation improves alumina digestion in the Bayer process. When the alumina-bearing material in bauxite ore is converted into non-magnetic material, the digestion temperature decreases significantly from 280 °C to 240 °C with a nearly 99% relative digestion ratio of alumina.
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Energy Technology Data Exchange (ETDEWEB)
Zhang, Ying [Department of Pharmacology, Hebei University of Chinese Medicine, Shijiazhuang 050200, Hebei (China); Department of Pathology, Hebei University of Chinese Medicine, Shijiazhuang 050200, Hebei (China); Hebei Key Laboratory of Chinese Medicine Research on Cardio-Cerebrovascular Disease, Shijiazhuang 050200, Hebei (China); Zhao, Xin [Department of Hepatobiliary Surgery, The Third Hospital of Hebei Medical University, Shijiazhuang 050051, Hebei (China); Chang, Yanzhong [Laboratory of Molecular Iron Metabolism, College of Life Science, Hebei Normal University, Shijiazhuang 050024, Hebei (China); Zhang, Yuanyuan [Department of Pharmacology, Hebei University of Chinese Medicine, Shijiazhuang 050200, Hebei (China); Chu, Xi [Department of Pharmacy, The Forth Hospital of Hebei Medical University, Shijiazhuang 050011, Hebei (China); Zhang, Xuan [Department of Pharmacology, Hebei University of Chinese Medicine, Shijiazhuang 050200, Hebei (China); Liu, Zhenyi; Guo, Hui [Department of Medicinal Chemistry, Hebei University of Chinese Medicine, Shijiazhuang 050200, Hebei (China); Wang, Na [Department of Physiology, Hebei University of Chinese Medicine, Shijiazhuang 050200, Hebei (China); Gao, Yonggang [Department of Pharmacology, Hebei University of Chinese Medicine, Shijiazhuang 050200, Hebei (China); Zhang, Jianping, E-mail: zhangjianping14@126.com [Department of Pharmacology, Hebei University of Chinese Medicine, Shijiazhuang 050200, Hebei (China); Chu, Li, E-mail: chuli0614@126.com [Department of Pharmacology, Hebei University of Chinese Medicine, Shijiazhuang 050200, Hebei (China); Hebei Key Laboratory of Integrative Medicine on Liver-Kidney Patterns, Shijiazhuang 050200, Hebei (China)
2016-06-15
Liver fibrosis is the principal cause of morbidity and mortality in patients with iron overload. Calcium channel blockers (CCBs) can antagonize divalent cation entry into renal and myocardial cells and inhibit fibrogenic gene expression. We investigated the potential of CCBs to resolve iron overload-associated hepatic fibrosis. Kunming mice were assigned to nine groups (n = 8 per group): control, iron overload, deferoxamine, high and low dose verapamil, high and low dose nimodipine, and high and low dose diltiazem. Iron deposition and hepatic fibrosis were measured in mouse livers. Expression levels of molecules associated with transmembrane iron transport were determined by molecular biology approaches. In vitro HSC-T6 cells were randomized into nine groups (the same groups as the mice). Changes in proliferation, apoptosis, and metalloproteinase expression in cells were detected to assess the anti-fibrotic effects of CCBs during iron overload conditions. We found that CCBs reduced hepatic iron content, intracellular iron deposition, the number of hepatic fibrotic areas, collagen expression levels, and hydroxyproline content. CCBs rescued abnormal expression of α1C protein in L-type voltage-dependent calcium channel (LVDCC) and down-regulated divalent metal transporter-1 (DMT-1) expression in mouse livers. In iron-overloaded HSC-T6 cells, CCBs reduced iron deposition, inhibited proliferation, induced apoptosis, and elevated expression of matrix metalloproteinase-13 (MMP-13) and tissue inhibitor of metalloproteinase-1 (TIMP-1). CCBs are potential therapeutic agents that can be used to address hepatic fibrosis during iron overload. They resolve hepatic fibrosis probably correlated with regulating transmembrane iron transport and inhibiting HSC growth. - Highlights: • Calcium channel blockers (CCBs) reduced hepatic iron content. • CCBs decreased hepatic fibrotic areas and collagen expression levels. • CCBs resolve fibrosis by regulating iron transport and
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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
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Efficacy of a low-dose ferric-EDTA in reducing iron deficiency ...
African Journals Online (AJOL)
Iron deficiency anaemia is a public health problem in Tanzania especially among children under the age of five years. In malaria holoendemic areas, control of anaemia by supplementation with iron has been reported to increase serious adverse events. The World Health Organization recommends that, programs to control ...
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Full Text Available ... Precision Medicine Activities Obesity, Nutrition, and Physical Activity Population and Epidemiology Studies Women’s Health All Science A- ... to help your body absorb iron. Avoid drinking black tea, which reduces iron ... was associated with a greater risk of death even with mild anemia. Now, anemia in older ...
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Miraei Ashtiani, Seyed-Hassan; Sturm, Barbara; Nasirahmadi, Abozar
2018-04-01
Drying and physicochemical characteristics of nectarine slices were investigated using hot-air and hybrid hot air-microwave drying methods under fixed air temperature and air speed (50 °C and 0.5 m/s, respectively). Microwave power levels for the combined hot air-microwave method were 80, 160, 240, and 320 W. Drying kinetics were analyzed and compared using six mathematical models. For both drying methods the model with the best fitness in explaining the drying behavior was the Midilli-Kucuk model. The coefficient of determination ( R 2), root mean square error (RMSE) and reduced chi square ( χ 2) for this model have been obtained greater than 0.999 and less than 0.006 and 0.0001 for hybrid hot air-microwave drying while those values for hot-air drying were more than 0.999 and less than 0.003 and 0.0001, respectively. Results showed that the hybrid method reduced the drying time considerably and produced products with higher quality. The range of effective moisture diffusivity ( D eff ) of hybrid and hot-air drying was between 8.15 × 10-8 and 2.83 × 10-7 m2/s and 1.27 × 10-8 m2/s, respectively. The total color difference (ΔE) has also been obtained from 36.68 to 44.27 for hybrid method; however this value for hot-air drying was found 49.64. Although reduced microwave power output led to a lower drying rate, it reduced changes in product parameters i.e. total color change, surface roughness, shrinkage and microstructural change and increased hardness and water uptake.
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DEFF Research Database (Denmark)
Castberg, Filip C; Maretty, Lasse; Staalsoe, Trine
2018-01-01
infected mice had extramedullary splenic haematopoiesis, and iron-supplemented mice had visually detectable intracellular iron stores. CONCLUSIONS: Blood transfusions are the only currently available means to correct severe anaemia in children with malaria. The potential of carefully timed, short...... parts of the world. This has rendered interventions against iron deficiency in malaria-endemic areas controversial. METHODS: The effect of nutritional iron deficiency on the clinical outcome of Plasmodium chabaudi AS infection in A/J mice and the impact of intravenous iron supplementation with ferric...... deficiency was associated with increased mortality from P. chabaudi malaria. This increased mortality could be partially offset by carefully timed, short-duration adjunctive iron supplementation. Moribund animals were characterized by low levels of hepcidin and high levels of fibroblast growth factor 23. All...
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Rizvi, Masood Ahmad; Syed, Raashid Maqsood; Khan, Badruddin
2011-01-01
A titration curve with multiple inflection points results when a mixture of two or more reducing agents with sufficiently different reduction potentials are titrated. In this experiment iron(II) complexes are combined into a mixture of reducing agents and are oxidized to the corresponding iron(III) complexes. As all of the complexes involve the…
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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
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Anti frictional materials iron-pig iron-brass manufacture using shaving waste products of pig-iron
International Nuclear Information System (INIS)
Nasamov, S. N.; Krivij, N.; Gudenau, H. W.; Babich, A. I.; Garcia, L. L.; Formoso, A.; Cores, A.
2003-01-01
Parts based on iron and steel powders are widely used in the manufacture of automobile and domestic equipment. This work was done to study the anti-friction properties of iron-pig iron-brass compositions of materials which were obtained by pressing and sintering from a mix of iron powders and industrial by products of cast-iron turnings, brass, talc and technical sulphur. Experiments were performed using cold pressure technology in the flowing matrix of the powder composite without solid lubricants. The subsequent sintering was carried out at 1200 degree centigree under isothermal conditions in a nitrogen atmosphere in the sintering zone during 1 h. The physical-mechanical and anti-friction properties were almost double by the active drainage of the gases from the compression mould. The study of the microstructure of the sintered materials showed that free cementite existed between the particle limits and around the pores. large agglomerations of dark inclusions could be observed, consisting of graphite, zinc and iron oxides, which were points of tension in the materials that reduce its durability and, therefore, its wear resistance to dry friction. (Author) 34 refs
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Swain, James H; Newman, Samuel M; Hunt, Janet R
2003-11-01
Foods are fortified with elemental forms of iron to reduce iron deficiency. However, the nutritional efficacy of current, commercially produced elemental iron powders has not been verified. We determined the bioavailability of six commercial elemental iron powders and examined how physicochemistry influences bioavailability. Relative biological value (RBV) of the iron powders was determined using a hemoglobin repletion/slope ratio method, treating iron-deficient rats with repletion diets fortified with graded quantities of iron powders, bakery-grade ferrous sulfate or no added iron. Iron powders were assessed physicochemically by measuring iron solubility in hydrochloric acid at pH 1.0 and 1.7, surface area by nitrogen gas adsorption and surface microstructure by electron microscopy. Bioavailability from the iron powders, based on absolute iron intake, was significantly less than from FeSO4 (100%; P Electrolytic (54%; A-131, U.S.) > Electrolytic (46%; Electrolytic Iron, India) > H-Reduced (42%; AC-325, U.S.) > Reduced (24%; ATOMET 95SP, Canada) > CO-Reduced (21%; RSI-325, Sweden). Solubility testing of the iron powders resulted in different relative rankings and better RBV predictability with increasing time at pH 1.7 (R2 = 0.65 at 150 min). The prediction was improved with less time and lower pH (R2 = 0.82, pH 1.0 at 30 min). Surface area, ranging from 90 to 370 m2/kg, was also highly predictive of RBV (R2 = 0.80). Bioavailability of iron powders is less than bakery-grade ferrous sulfate and varies up to three times among different commercial forms. Solubility at pH 1.0 and surface area were predictive of iron bioavailability in rats.
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Directory of Open Access Journals (Sweden)
Jiannan Ding
2011-06-01
Full Text Available A novel thermoacidophilic iron and sulfur-oxidizing archaeon, strain YN25, was isolated from an in situ enriched acid hot spring sample collected in Yunnan, China. Cells were irregular cocci, about 0.9-1.02 µm×1.0-1.31 µm in the medium containing elemental sulfur and 1.5-2.22 µm×1.8-2.54 µm in ferrous sulfate medium. The ranges of growth and pH were 50-85 (optimum 65 and pH 1.0-6.0 (optimum 1.5-2.5. The acidophile was able to grow heterotrophically on several organic substrates, including various monosaccharides, alcohols and amino acids, though the growth on single substrate required yeast extract as growth factor. Growth occurred under aerobic conditions or via anaerobic respiration using elemental sulfur as terminal electron acceptor. Results of morphology, physiology, fatty acid analysis and analysis based on 16S rRNA gene sequence indicated that the strain YN25 should be grouped in the species Acidianus manzaensis. Bioleaching experiments indicated that this strain had excellent leaching capacity, with a copper yielding ratio up to 79.16% in 24 d. The type strain YN25 was deposited in China Center for Type Culture Collection (=CCTCCZNDX0050.
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Radecker, Nils; Pogoreutz, Claudia; Ziegler, Maren; Ashok, Ananya; Barreto, Marcelle M.; Chaidez, Veronica; Grupstra, Carsten G. B.; Ng, Yi Mei; Perna, Gabriela; Aranda, Manuel; Voolstra, Christian R.
2017-01-01
The productivity of coral reefs in oligotrophic tropical waters is sustained by an efficient uptake and recycling of nutrients. In reef-building corals, the engineers of these ecosystems, this nutrient recycling is facilitated by a constant exchange of nutrients between the animal host and endosymbiotic photosynthetic dinoflagellates (zooxanthellae), bacteria, and other microbes. Due to the complex interactions in this so-called coral holobiont, it has proven difficult to understand the environmental limitations of productivity in corals. Among others, the micronutrient iron has been proposed to limit primary productivity due to its essential role in photosynthesis and bacterial processes. Here, we tested the effect of iron enrichment on the physiology of the coral Pocillopora verrucosa from the central Red Sea during a 12-day experiment. Contrary to previous reports, we did not see an increase in zooxanthellae population density or gross photosynthesis. Conversely, respiration rates were significantly increased, and microbial nitrogen fixation was significantly decreased. Taken together, our data suggest that iron is not a limiting factor of primary productivity in Red Sea corals. Rather, increased metabolic demands in response to iron enrichment, as evidenced by increased respiration rates, may reduce carbon (i.e., energy) availability in the coral holobiont, resulting in reduced microbial nitrogen fixation. This decrease in nitrogen supply in turn may exacerbate the limitation of other nutrients, creating a negative feedback loop. Thereby, our results highlight that the effects of iron enrichment appear to be strongly dependent on local environmental conditions and ultimately may depend on the availability of other nutrients.
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Radecker, Nils
2017-07-31
The productivity of coral reefs in oligotrophic tropical waters is sustained by an efficient uptake and recycling of nutrients. In reef-building corals, the engineers of these ecosystems, this nutrient recycling is facilitated by a constant exchange of nutrients between the animal host and endosymbiotic photosynthetic dinoflagellates (zooxanthellae), bacteria, and other microbes. Due to the complex interactions in this so-called coral holobiont, it has proven difficult to understand the environmental limitations of productivity in corals. Among others, the micronutrient iron has been proposed to limit primary productivity due to its essential role in photosynthesis and bacterial processes. Here, we tested the effect of iron enrichment on the physiology of the coral Pocillopora verrucosa from the central Red Sea during a 12-day experiment. Contrary to previous reports, we did not see an increase in zooxanthellae population density or gross photosynthesis. Conversely, respiration rates were significantly increased, and microbial nitrogen fixation was significantly decreased. Taken together, our data suggest that iron is not a limiting factor of primary productivity in Red Sea corals. Rather, increased metabolic demands in response to iron enrichment, as evidenced by increased respiration rates, may reduce carbon (i.e., energy) availability in the coral holobiont, resulting in reduced microbial nitrogen fixation. This decrease in nitrogen supply in turn may exacerbate the limitation of other nutrients, creating a negative feedback loop. Thereby, our results highlight that the effects of iron enrichment appear to be strongly dependent on local environmental conditions and ultimately may depend on the availability of other nutrients.
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Using iron line reverberation and spectroscopy to distinguish Kerr and non-Kerr black holes
Energy Technology Data Exchange (ETDEWEB)
Jiang, Jiachen; Bambi, Cosimo [Center for Field Theory and Particle Physics and Department of Physics, Fudan University, 220 Handan Road, 200433 Shanghai (China); Steiner, James F., E-mail: jcjiang12@fudan.edu.cn, E-mail: bambi@fudan.edu.cn, E-mail: jsteiner@cfa.harvard.edu [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)
2015-05-01
The iron Kα line commonly observed in the X-ray spectrum of both stellar-mass and supermassive black hole candidates is produced by the illumination of a cold accretion disk by a hot corona. In this framework, the activation of a new flaring region in the hot corona imprints a time variation on the iron line spectrum. Future X-ray facilities with high time resolution and large effective areas may be able to measure the so-called 2-dimensional transfer function; that is, the iron line profile detected by a distant observer as a function of time in response to an instantaneous flare from the X-ray primary source. This work is a preliminary study to determine if and how such a technique can provide more information about the spacetime geometry around the compact object than the already possible measurements of the time-integrated iron line profile. Within our simplified model, we find that a measurement of iron line reverberation can improve constraints appreciably given a sufficiently strong signal, though that most of the information is present in the time-integrated spectrum. Our aim is to test the Kerr metric. We find that current X-ray facilities and data are unable to provide strong tests of the Kerr nature of supermassive black hole candidates. We consider an optimistic case of 10{sup 5} iron line photons from a next-generation data set. With such data, the reverberation model improves upon the spectral constraint by an order of magnitude.
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Long-term intake of iron fortified wholemeal rye bread appears to benefit iron status of young women
DEFF Research Database (Denmark)
Hansen, Max; Nielsen, Sussi Bæch; Thomsen, A.D.
2005-01-01
The efficacy of intake of iron fortified, wholemeal rye bread on iron status of young women with low iron stores was evaluated in a 5 month single-blind intervention study. Two parallel groups of women (20-38 y) were given 144 g of rye bread/d either fortified with 6 mg iron as ferrous fumarate/100...... stores of young women with poor iron status which were otherwise reduced by intake of the unfortified control bread....
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Method and apparatus for enhancing the desulfurization of hot coal gas in a fluid-bed coal gasifier
Grindley, T.
1988-04-05
A process and apparatus for providing additional desulfurization of the hot gas produced in a fluid-bed coal gasifier, within the gasifier is described. A fluid-bed of iron oxide is located inside the gasifier above the gasification bed in a fluid-bed coal gasifier in which in-bed desulfurization by lime/limestone takes place. The product gases leave the gasification bed typically at 1600 to 1800 F and are partially quenched with water to 1000 to 1200 F before entering the iron oxide bed. The iron oxide bed provides additional desulfurization beyond that provided by the lime /limestone. 1 fig.
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Wintertime pytoplankton bloom in the Subarctic Pacific supportedby continental margin iron
Energy Technology Data Exchange (ETDEWEB)
Lam, Phoebe J.; Bishop, James K.B.; Henning, Cara C.; Marcus,Matthew A.; Waychunas, Glenn A.; Fung, Inez
2004-06-08
Heightened biological activity was observed in February 1996in the high-nutrient low-chlorophyll (HNLC) subarctic North PacificOcean, a region that is thought to beiron-limited. Here we provideevidence supporting the hypothesis that Ocean Station Papa (OSP) in thesubarctic Pacific received a lateral supply of particulate iron from thecontinental margin off the Aleutian Islands in the winter, coincidentwith the observed biological bloom. Synchrotron X-ray analysis was usedto describe the physical form, chemistry, and depth distributions of ironin size fractionated particulate matter samples. The analysis revealsthat discrete micron-sized iron-rich hotspots are ubiquitous in the upper200m at OSP, more than 900km from the closest coast. The specifics of thechemistry and depth profiles of the Fe hot spots trace them to thecontinental margins. We thus hypothesize that iron hotspots are a markerfor the delivery of iron from the continental margin. We confirm thedelivery of continental margin iron to the open ocean using an oceangeneral circulation model with an iron-like tracer source at thecontinental margin. We suggest that iron from the continental marginstimulated a wintertime phytoplankton bloom, partially relieving the HNLCcondition.
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Xia, Tian; Zhao, Yan; Sager, Tina; George, Saji; Pokhrel, Suman; Li, Ning; Schoenfeld, David; Meng, Huan; Lin, Sijie; Wang, Xiang; Wang, Meiying; Ji, Zhaoxia; Zink, Jeffrey I.; Mädler, Lutz; Castranova, Vincent; Lin, Shuo; Nel, Andre E.
2014-01-01
We have recently shown that the dissolution of ZnO nanoparticles and Zn2+ shedding leads to a series of sub-lethal and lethal toxicological responses at cellular level that can be alleviated by iron-doping. Iron-doping changes the particle matrix and slows the rate of particle dissolution. To determine whether iron doping of ZnO also leads to lesser toxic effects in vivo, toxicity studies were performed in rodent and zebrafish models. First, we synthesized a fresh batch of ZnO nanoparticles doped with 1–10 wt % of Fe. These particles were extensively characterized to confirm their doping status, reduced rate of dissolution in an exposure medium and reduced toxicity in a cellular screen. Subsequent studies compared the effects of undoped to doped particles in the rat lung, mouse lung and the zebrafish embryo. The zebrafish studies looked at embryo hatching and mortality rates as well as the generation of morphological defects, while the endpoints in the rodent lung included an assessment of inflammatory cell infiltrates, LDH release and cytokine levels in the bronchoalveolar lavage fluid. Iron doping, similar to the effect of the metal chelator, DTPA, interfered in the inhibitory effects of Zn2+ on zebrafish hatching. In the oropharyngeal aspiration model in the mouse, iron doping was associated with decreased polymorphonuclear cell counts and IL-6 mRNA production. Doped particles also elicited decreased heme oxygenase 1 expression in the murine lung. In the intratracheal instillation studies in the rat, Fe-doping was associated with decreased polymorphonuclear cell counts, LDH and albumin levels. All considered, the above data show that Fe-doping is a possible safe design strategy for preventing ZnO toxicity in animals and the environment. PMID:21250651
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Energy Technology Data Exchange (ETDEWEB)
Hayes, Kim F. [Univ. of Michigan, Ann Arbor, MI (United States); Bi, Yuqiang [Univ. of Michigan, Ann Arbor, MI (United States); Carpenter, Julian [Univ. of Michigan, Ann Arbor, MI (United States); Hyng, Sung Pil [Univ. of Michigan, Ann Arbor, MI (United States); Rittmann, Bruce E. [Arizona State Univ., Tempe, AZ (United States); Zhou, Chen [Arizona State Univ., Tempe, AZ (United States); Vannela, Raveender [Arizona State Univ., Tempe, AZ (United States); Davis, James A. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
2013-12-31
This overarching aim of this project was to identify the role of biogenic and synthetic iron-sulfide minerals in the long-term sequestration of reduced U(IV) formed under sulfate-reducing conditions when subjected to re-oxidizing conditions. The work reported herein was achieved through the collaborative research effort conducted at Arizona State University (ASU) and the University of Michigan (UM). Research at ASU, focused on the biogenesis aspects, examined the biogeochemical bases for iron-sulfide production by Desulfovibrio vulgaris, a Gram-negative bacterium that is one of the most-studied strains of sulfate-reducing bacteria. A series of experimental studies were performed to investigate comprehensively important metabolic and environmental factors that affect the rates of sulfate reduction and iron-sulfide precipitation, the mineralogical characteristics of the iron sulfides, and how uranium is reduced or co-reduced by D. vulagaris. FeS production studies revealed that controlling the pH affected the growth of D. vulgaris and strongly influenced the formation and growth of FeS solids. In particular, lower pH produced larger-sized mackinawite (Fe1+xS). Greater accumulation of free sulfide, from more sulfate reduction by D. vulgaris, also led to larger-sized mackinawite and stimulated mackinawite transformation to greigite (Fe3S4) when the free sulfide concentration was 29.3 mM. On the other hand, using solid Fe(III) (hydr)oxides as the iron source led to less productivity of FeS due to their slow and incomplete dissolution and scavenging of sulfide. Furthermore, sufficient free Fe2+, particularly during Fe(III) (hydr)oxide reductions, led to the additional formation of vivianite [Fe3(PO4)2•8(H2O)]. The U(VI) reduction studies revealed that D. vulgaris reduced U(VI) fastest when accumulating sulfide from concomitant sulfate reduction, since direct enzymatic and sulfide
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Basic feasibility study on energy conservation at Lianyuan Iron and Steel Group Co., Ltd.
Energy Technology Data Exchange (ETDEWEB)
NONE
2001-03-01
For the purpose of conserving energy and reducing greenhouse effect gas emission, a feasibility study was carried out of the installation of energy conservation facilities at the steelworks of Lianyuan Iron and Steel Group Complex, Loudi City, Hunan Province, China. The installation of the following facilities was studied: coke dry quenching (CDQ) equipment, coal moisture control (CMC) equipment, sintering ignition furnace equipment, cooler exhaust heat recovery equipment, top pressure recovery turbine (TRT), and hot stove exhaust heat recovery equipment. As a result of the study, the energy conservation amount was 20,000 toe/y by CDQ, 2,530 toe/y by CMC, 900 toe/y by improvement of ignition furnace in the sintering process, 12,300 toe/y by sintering cooler, 13,200 toe/y by TRT, and 10,300 toe/y by hot stove exhaust heat recovery equipment. Further, the amount of greenhouse effect gas reduction was 61,022 t-CO2/y, 7,843 t-CO2/y, 2,896 t-CO2/y, 38,060 t-CO2/y, 55,295 t-CO2/y, and 40,621 t-CO2/y, respectively. In the estimation of effects vs. expenses, the sintering ignition furnace, sintering cooler exhaust heat recovery, and hot stove exhaust heat recovery indicated the comparatively favorable values. (NEDO)
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Durable zinc ferrite sorbent pellets for hot coal gas desulfurization
Jha, Mahesh C.; Blandon, Antonio E.; Hepworth, Malcolm T.
1988-01-01
Durable, porous sulfur sorbents useful in removing hydrogen sulfide from hot coal gas are prepared by water pelletizing a mixture of fine zinc oxide and fine iron oxide with inorganic and organic binders and small amounts of activators such as sodium carbonate and molybdenite; the pellets are dried and then indurated at a high temperature, e.g., 1800.degree. C., for a time sufficient to produce crush-resistant pellets.
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Iron deficiency anaemia in pregnancy: The role of parenteral iron.
Esen, Umo I
2017-01-01
Maternal and perinatal morbidity and mortality remain major challenges in the delivery of safe maternity care worldwide. Anaemia in pregnancy is an important contributor to this dismal picture, especially where blood transfusion services are poorly developed. An early diagnosis and treatment of iron deficiency anaemia in pregnancy using the new generation dextran-free parenteral iron preparations can save lives and reduce morbidity in selected pregnancies. It is time to cast aside the fears associated with the use of the old parenteral iron preparations which were associated a high incidence of anaphylaxis, and embrace the use of new parenteral iron products which have better side effect profiles and can deliver total dose infusions without the need for test dosing. In selected women, the benefits of this treatment far outweigh any disadvantages.
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Iron deficiency anaemia: with the conclusion of a need for iron reader
Lim, Wai Feng; Yap, Boon Kar; Lai, Mei I.; Talik, Noorazrina; Nasser, Ammar Ahmed; Al-Haiqi, Ahmed Mubarak Ahmed; Sankar Krishnan, Prajindra
2017-10-01
In our bloodstream, there are plenty of red blood cells (RBC), which function as an important oxygen carrier in our bodies. Each RBC consists of millions of haemoglobin (Hb), which is made up from globin and iron. If any deficiency/malfunction of any globin, it will lead to anaemia as indicated in low Hb level while iron deficiency anaemia (IDA) is anaemic due to the lacking of iron as indicated in low Hb and ferritin levels. IDA affects almost two billion people globally while anaemia without iron deficiency, such as thalassaemia, affects almost 4.5% in Malaysian population. These anaemic conditions have similar clinical symptoms like fatigue, dizziness, in which disturb their cognitive development and productivity in workplace. In areas without proper medical access, many anaemic individuals were misdiagnosed and treated with iron tablets because they were thought to have iron deficiency anaemia due to low Hb content. But, excess iron is toxic to the body. Misdiagnosis can be avoided by iron status assessment. We hereby review the currently available iron status parameters in laboratory and field study with the conclusion of demonstrating the importance of a need for iron reader, in the effort to reduce the prevalence of IDA globally.
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Heart failure in patients with kidney disease and iron deficiency; the role of iron therapy.
Cases Amenós, Aleix; Ojeda López, Raquel; Portolés Pérez, José María
Chronic kidney disease and anaemia are common in heart failure (HF) and are associated with a worse prognosis in these patients. Iron deficiency is also common in patients with HF and increases the risk of morbidity and mortality, regardless of the presence or absence of anaemia. While the treatment of anaemia with erythropoiesis-stimulating agents in patients with HF have failed to show a benefit in terms of morbidity and mortality, treatment with IV iron in patients with HF and reduced ejection fraction and iron deficiency is associated with clinical improvement. In a posthoc analysis of a clinical trial, iron therapy improved kidney function in patients with HF and iron deficiency. In fact, the European Society of Cardiology's recent clinical guidelines on HF suggest that in symptomatic patients with reduced ejection fraction and iron deficiency, treatment with IV ferric carboxymaltose should be considered to improve symptoms, the ability to exercise and quality of life. Iron plays a key role in oxygen storage (myoglobin) and in energy metabolism, and there are pathophysiological bases that explain the beneficial effect of IV iron therapy in patients with HF. All these aspects are reviewed in this article. Copyright © 2017 Sociedad Española de Nefrología. Published by Elsevier España, S.L.U. All rights reserved.
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Sultana, Tanjim; DeVita, Maria V; Michelis, Michael F
2016-09-01
Functional iron deficiency (FID) is a major cause of persistent anemia in dialysis patients and also contributes to a suboptimal response to erythropoietin (Epo) administration. Vitamin C acts as an enzyme cofactor and enhances mobilization of the ferrous form of iron to transferrin thus increasing its bioavailability. High-dose intravenous vitamin C has been shown to decrease the Epo requirement and improve hemoglobin levels in previous studies. This study assessed the effect of low-dose oral vitamin C on possible reduction in Epo dose requirements in stable hemodialysis patients with FID. This prospective study included 22 stable hemodialysis patients with FID defined as transferrin saturation (T sat) 100 mcg/L with Epo requirement of ≥4000 U/HD session. Patients received oral vitamin C 250 mg daily for 3 months. Hemoglobin, iron and T sat levels were recorded monthly. No one received iron supplementation during the study period. There was a significant reduction in median Epo dose requirement in the 15 patients who completed the study, from 203.1 U/kg/week (95 % CI 188.4-270.6) to 172.8 U/kg/week (95 % CI 160.2-214.8), (P = 0.01). In the seven responders, there was 33 % reduction in Epo dose from their baseline. Despite adjustment of Epo dose, the mean hemoglobin level was significantly increased from 10.1 ± 0.6 to 10.7 ± 0.6 mg/dL (P = 0.03). No adverse effects of oral vitamin C were observed. Daily low-dose oral vitamin C supplementation reduced Epo dose requirements in hemodialysis patients with FID. Limitations of this study include a small sample size and the lack of measurements of vitamin C and oxalate levels. Despite concerns regarding oral vitamin C absorption in dialysis patients, this study indicates vitamin C was well tolerated by all participants without reported adverse effect.
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IRON BIOAVAILABILITY IN CAMEROON WEANING FOODS AND ...
African Journals Online (AJOL)
Dialyzable iron value were enhanced with lime juice and significantly reduced by legumes (beans, soy bean, and groundnut), egg and egg yolk. Irish potatoes based diets were the best sources of dialyzable iron. Iron intakes were sufficient for most balanced diets to cover the recommended daily intakes of iron for children ...
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The pollution of the 'iron gate' reservoir
International Nuclear Information System (INIS)
Babic-Mladenovic, M.; Varga, S; Popovic, L.; Damjanovic, M.
2002-01-01
The paper presents the characteristics of the Iron Gate I (the Djerdap) Water Power and Navigational System, one of the largest in Europe (completed in 1972 by joint efforts of Yugoslavia and Romania). In this paper the attention is devoted to review of the sediment monitoring program and impacts of reservoir sedimentation, as well as to the investigations of water and sediment quality. Special consideration is paid to the issue of sediment pollution research needs. Namely, the hot spot of the 'Iron Gate' sedimentation represents a scarcely known pollution of sediment deposits. The present pollution probably is considerable, since the 'Iron Gate' reservoir drains about 577000 km 2 , with over 80 million inhabitants, and developed municipal and industrial infrastructure. Therefore, in the thirty-year reservoir life various types of sediment-bound pollutants entered and deposited within it. Especially severe incidents happened during 1999 (as a result of NATO bombing campaign) and 2000 (two accidental pollutions in the Tisza river catchment). The study of the 'Iron Gate' reservoir pollution should be prepared in order to enlighten the present state of reservoir sedimentation and pollution. The main objectives of the study are to enhance the government and public awareness of the present environmental state of the 'Iron Gate' reservoir and to serve as a baseline for all future actions. (author)
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Salivary proline-rich protein may reduce tannin-iron chelation: a systematic narrative review
Delimont, Nicole M.; Rosenkranz, Sara K.; Haub, Mark D.; Lindshield, Brian L.
2017-01-01
Background Tannins are often cited for antinutritional effects, including chelation of non-heme iron. Despite this, studies exploring non-heme iron bioavailability inhibition with long-term consumption have reported mixed results. Salivary proline-rich proteins (PRPs) may mediate tannin-antinutritional effects on non-heme iron bioavailability. Aim To review evidence regarding biochemical binding mechanisms and affinity states between PRPs and tannins, as well as effects of PRPs on non-heme ir...
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International Nuclear Information System (INIS)
Zhou Quanyu; Tan Kaixuan; Zeng Sheng; Liu Dong
2009-01-01
The treatment of uranium-bearing wastewater from uranium mine and using microorganism to treat wastewater were paid much attention to environmental researchers. Based on column experiments, we investigated the potential using sulfate reducing bacteria (SRB) and zero-valent iron (ZVI) to synergetic treat contamination in wastewater such as sulfate, uranium, etc. SRB+ZVI can effectively remove contamination U(VI) and SO 4 2- in wastewater. The removal rate is 99.4% and 86.2% for U(VI) and SO 4 2- , respectively. The pH of wastewater can be basified to neutral. U(VI) and SO 4 2- as electron acceptor of sulfate reducing bacteria are removed by biological reduction. The corrosion of ZVI is benefit to enhance the pH of wastewater, forms anaerobic reducing environment, strengthens survival and metabolism reaction of SRB, and plays a synergetic enhancement. (authors)
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ABSORBABLE IRON IN BREAD: PROCEDURES OF ITS AUGMENTATION
Directory of Open Access Journals (Sweden)
M SABZEVARY
2001-12-01
Full Text Available Introduction: As many as 35 percent of the world population suffer from some degree of iron deficiency anemia. According to recent reports published by WHO and ICN (International Congress of Nutrition 20-40 percent of women are suffering from iron deficiency. Iron deficiency anemia is caused by lack of intake of the necessary doses of Fe+2 called Heme. The recommended intake dose is 10-17 mg Fe + 2/day. In Iran, bread is the main source of daily iron intake. However, the iron content of bread is Fe+3 which is not absorbable. The objectives of this study is to determine the levels of absorbable iron (Fe + 2 in two common types of Iranian bread and identify the means of raising these to an adequate levels.
Methods: Random sampling method together with the normal distribution curve was employed in testing 120 samples of flour and bread. Quantification was carried out on each sample in duplicate using spectrophotometer at 510 mu, micrometer wave length. The effect of three organic acids (lactic ascorbic and acetic acid converting of Fe+3 to Fe + 2 was investigated. Two groups of bread was tested. One group was baked in tratitional oven (Noon-e-Tanoori and the second group through the common Iranian hot rotating iron plate baking machine (Noon-e-Machini.
Results: Our results showed that the amount of absorbable Fe+2 in breads baked in rotatory oven (Noon-e-Tanoori is 0.8 ± 0.32 mg and the amount of unabsorbable Fe+3 in dried bread is 2.34 ± 0.25 mg/100 gm while the amount of absorbable Fe + 2 baked in traditional ovens is only 0.3±0.11 mg versus of unabsorbable Fe + 3 1.9±0.13 mg/100 gm of dried bread. Meanwhile it was found that lactic and ascorbic acids can convert Fe+3 to Fe+2. Therefore, addition of one of these two acids to bread can catalyze conversion of unabsorbable Fe+3 to absorbable Fe + 2.
Discussion: On the average an Iranian consumes 370 gm of -
Hackl, Laura; Speich, Cornelia; Zeder, Christophe; Sánchez-Ferrer, Antoni; Adelmann, Horst; de Pee, Saskia; Tay, Fabian; Zimmermann, Michael B; Moretti, Diego
2017-12-01
Background: Rice can be fortified with the use of hot or cold extrusion or coating, but the nutritional qualities of the resulting rice grains have never been directly compared. Objective: Using fortified rice produced by coating or hot or cold extrusion, we compared 1 ) iron and zinc absorption with the use of stable isotopes, 2 ) iron and zinc retention during cooking, and 3 ) starch microstructure. Methods: We conducted 2 studies in young women: in study 1 [ n = 19; mean ± SD age: 26.2 ± 3.4 y; body mass index (BMI; in kg/m 2 ): 21.3 ± 1.6], we compared the fractional iron absorption (FAFe) from rice meals containing isotopically labeled ferric prophosphate ( 57 FePP), zinc oxide (ZnO), citric acid, and micronutrients fortified through hot extrusion (HER1) with rice meals fortified through cold extrusion containing 57 FePP, ZnO, citric acid, and micronutrients (CER); in study 2 ( n = 22; age: 24 ± 4 y; BMI: 21.2 ± 1.3), we compared FAFe and fractional zinc absorption (FAZn) from rice meals fortified through hot extrusion (HER2) compared with rice meals fortified through coating containing 57 FePP, ZnO, a citric acid and trisodium cirate mixture (CA/TSC), and micronutrients (COR) relative to rice meals extrinsically fortified with ferrous sulfate (reference). Rice types HER1 and CER contained citric acid, whereas types HER2 and COR contained CA/TSC. We assessed retention during standardized cooking experiments and characterized the rice starch microstructure. Results: FAFe (95% CI) was greater from CER [2.2% (1.4%, 3.4%)] than from HER1 [1.2% (0.7%, 2.0%)] ( P = 0.036). There was no difference in FAFe between HER2 [5.1% (3.7%, 7.1%)] and COR [4.0% (2.9%, 5.4%)] ( P = 0.14), but FAFe from COR was lower than that from the reference meal [6.6% (4.9%, 9.0%)] ( P = 0.003), and the geometric mean FAZn (95% CI) did not differ between HER2 [9.5% (7.9%, 11.6%)] and COR [9.6% (8.7%, 10.7%)] ( P = 0.92). Cooking in a rice-to-water ratio of 1:2 resulted in iron and zinc
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Wintertime phytoplankton bloom in the Subarctic Pacific supported by continental margin iron
International Nuclear Information System (INIS)
Lam, Phoebe J.; Bishop, James K.B.; Henning, Cara C.; Marcus, Matthew A.; Waychunas, Glenn A.; Fung, Inez
2004-01-01
Heightened biological activity was observed in February 1996 in the high-nutrient low-chlorophyll (HNLC) subarctic North Pacific Ocean, a region that is thought to be iron-limited. Here we provide evidence supporting the hypothesis that Ocean Station Papa (OSP) in the subarctic Pacific received a lateral supply of particulate iron from the continental margin off the Aleutian Islands in the winter, coincident with the observed biological bloom. Synchrotron X-ray analysis was used to describe the physical form, chemistry, and depth distributions of iron in size fractionated particulate matter samples. The analysis reveals that discrete micron-sized iron-rich hotspots are ubiquitous in the upper 200m at OSP, more than 900km from the closest coast. The specifics of the chemistry and depth profiles of the Fe hot spots trace them to the continental margins. We thus hypothesize that iron hotspots are a marker for the delivery of iron from the continental margin. We confirm the delivery of continental margin iron to the open ocean using an ocean general circulation model with an iron-like tracer source at the continental margin. We suggest that iron from the continental margin stimulated a wintertime phytoplankton bloom, partially relieving the HNLC condition
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Reactive oxygen species-related activities of nano-iron metal and nano-iron oxides.
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.
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Heat losses through pipe connections in hot water stores
DEFF Research Database (Denmark)
Andersen, Elsa; Fan, Jianhua; Furbo, Simon
2007-01-01
The heat loss from pipe connections at the top of hot water storage tanks with and without a heat trap is investigated theoretically and compared to similar experimental investigations. Computational Fluid Dynamics (CFD) is used for the theoretical analysis. The investigations show that the heat...... loss from an ideally insulated pipe connected to the top of a hot water tank is mainly due to a natural convection flow in the pipe, that the heat loss coefficient of pipes connected to the top of a hot water tank is high, and that a heat trap can reduce the heat loss coefficient significantly. Further......, calculations show that the yearly thermal performance of solar domestic hot water systems is strongly reduced if the hot water tank has a thermal bridge located at the top of the tank....
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Preparation of yttrium iron garnet (YIG) by modified domestic iron oxide
International Nuclear Information System (INIS)
Mozaffari, M.; Amighian
2002-01-01
Iron oxide by product of a local steel complex was modified to use for preparation of Yttrium iron garnet (YIG). The improvement was necessary to reduce impurities, especially the Si0 2 and Cl contents, which have deteriorative effects on magnetic properties and equipment used for preparation of the samples. The modified iron oxide was then mixed with Yttrium oxide of Merck Company in appropriate proportion to obtain a stoichiometric single phase YIG, using the conventional ceramic technique. XRD and SEM equipments were used to identify the resulting phases and microstructure respectively. Magnetic parameters were measured by VSM. Curie temperature of the samples was obtained by DTG (M) method. The results were compared with those obtained from samples that made by Merck iron oxide. There are small differences between the results. This was discussed according to extra pores and minute secondary phase in the samples made by domestic iron oxide. (Author)
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Green tea or rosemary extract added to foods reduces nonheme- iron absorption
DEFF Research Database (Denmark)
Samman, S.; Sandstrøm, B.; Toft, M.B.
2001-01-01
the effect of phenolic-rich extracts obtained from green tea or rosemary on nonheme-iron absorption. Design: Young women aged 19-39 y consumed test meals on 4 separate occasions. The meals were identical except for the absence (meal A) or presence (meal B) of a phenolic-rich extract from green tea (study 1......-body retention of 59Fe and the ratio of Fe-55 to 59Fe activity in blood samples. Results: The presence of the phenolic-rich extracts resulted in decreased nonheme-iron absorption. Mean (+/-SD) iron absorption decreased from 12.1 +/- 4.5% to 8.9 +/- 5.2% (P tea extract and from 7...
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International Nuclear Information System (INIS)
Merwin, S.E.; Moeller, M.P.
1989-01-01
Nuclear Regulatory Commission (NRC) licensees are required to assess the dose to skin from a hot particle contamination event at a depth of skin of7mg/cm 2 over an area of 1 cm 2 and compare the value to the current dose limit for the skin. Although the resulting number is interesting from a comparative standpoint and can be used to predict local skin reactions, comparison of the number to existing limits based on uniform exposures is inappropriate. Most incidents that can be classified as overexposures based on this interpretation of dose actually have no effect on the health of the worker. As a result, resources are expended to reduce the likelihood that an overexposure event will occur when they could be directed toward eliminating the cause of the problem or enhancing existing programs such as contamination control. Furthermore, from a risk standpoint, this practice is not ALARA because some workers receive whole body doses in order to minimize the occurrence of hot particle skin contaminations. In this paper the authors suggest an alternative approach to controlling hot particle exposures
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Metal regeneration of iron chelates in nitric oxide scrubbing
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.
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Hot Spot Removal System: System description
Energy Technology Data Exchange (ETDEWEB)
NONE
1997-09-01
Hazardous wastes contaminated with radionuclides, chemicals, and explosives exist across the Department of Energy complex and need to be remediated due to environmental concerns. Currently, an opportunity is being developed to dramatically reduce remediation costs and to assist in the acceleration of schedules associated with these wastes by deploying a Hot Spot Removal System. Removing the hot spot from the waste site will remove risk driver(s) and enable another, more cost effective process/option/remedial alternative (i.e., capping) to be applied to the remainder of the site. The Hot Spot Removal System consists of a suite of technologies that will be utilized to locate and remove source terms. Components of the system can also be used in a variety of other cleanup activities. This Hot Spot Removal System Description document presents technologies that were considered for possible inclusion in the Hot Spot Removal System, technologies made available to the Hot Spot Removal System, industrial interest in the Hot Spot Removal System`s subsystems, the schedule required for the Hot Spot Removal System, the evaluation of the relevant technologies, and the recommendations for equipment and technologies as stated in the Plan section.
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Hot Spot Removal System: System description
International Nuclear Information System (INIS)
1997-09-01
Hazardous wastes contaminated with radionuclides, chemicals, and explosives exist across the Department of Energy complex and need to be remediated due to environmental concerns. Currently, an opportunity is being developed to dramatically reduce remediation costs and to assist in the acceleration of schedules associated with these wastes by deploying a Hot Spot Removal System. Removing the hot spot from the waste site will remove risk driver(s) and enable another, more cost effective process/option/remedial alternative (i.e., capping) to be applied to the remainder of the site. The Hot Spot Removal System consists of a suite of technologies that will be utilized to locate and remove source terms. Components of the system can also be used in a variety of other cleanup activities. This Hot Spot Removal System Description document presents technologies that were considered for possible inclusion in the Hot Spot Removal System, technologies made available to the Hot Spot Removal System, industrial interest in the Hot Spot Removal System''s subsystems, the schedule required for the Hot Spot Removal System, the evaluation of the relevant technologies, and the recommendations for equipment and technologies as stated in the Plan section
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Iron Supplementation, Response in Iron-Deficiency Anemia: Analysis of Five Trials.
Okam, Maureen M; Koch, Todd A; Tran, Minh-Ha
2017-08-01
Oral iron-replacement therapy is the mainstay of treatment for iron-deficiency anemia, but it is often poorly tolerated or ineffective. Hemoglobin response at day 14 of oral iron may be useful in assessing whether and when to transition patients from oral to intravenous (IV) iron. Pooled data from 5 randomized trials were analyzed to compare oral and IV iron-replacement therapy for iron-deficiency anemia. Treatment criteria and assignment to oral versus IV iron were defined per protocol; this analysis included only subjects receiving oral iron. Responders were subjects with ≥1.0-g/dL increases in hemoglobin at day 14, and nonresponders were those with smaller increases. Demographic and clinical characteristics were evaluated for association with hemoglobin response at multiple timepoints. Most subjects (72.8%) were classified as responders. The proportion of subjects with hemoglobin increases ≥1.0, ≥2.0, and ≥3.0 g/dL was greatest among those with postpartum anemia, intermediate among those with heavy uterine bleeding or gastrointestinal-related causes of anemia, and lowest among those with other causes; this proportion was also significantly greater among responders than nonresponders. A ≥1.0-g/dL increase in hemoglobin on day 14 most accurately predicted satisfactory overall hemoglobin response to oral iron on day 42/56 (sensitivity 90.1%; specificity 79.3%; positive and negative predictive values of 92.9% and 72.7%, respectively). Iron-replacement therapy improved quality of life and reduced fatigue. Hemoglobin responses <1.0 g/dL at day 14 of oral iron identify subjects with iron-deficiency anemia who should be transitioned to IV iron supplementation. Copyright © 2017 Elsevier Inc. All rights reserved.
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Effect of rhodium traces on the reducibility of silica-supported iron particles
Bonnefille, Eric; Millet, Jean Marc M M; Candy, Jean Pierre; Thivolle-Cazat, Jean; Bellabarba, Roñ an M.; Tooze, Robert P.; Basset, Jean-Marie
2012-01-01
Fe/SiO 2 and Rh-Fe/SiO 2 catalysts with increasing Fe/Rh ratio have been prepared and characterized by TEM, XRD, oxygen adsorption and Mössbauer spectroscopy. It was confirmed that Fe/SiO 2 catalysts cannot be reduced under hydrogen flow, to more than 50 % whatever the temperature in the 200-500 °C range and shown that the presence of even a small amount of Rh (Fe/Rh ≤2,000) promoted the reduction of iron up to 85-95 %. This promoting effect also took place with a Fe/SiO 2 + Rh/SiO 2 physical mixture (Fe/Rh B2,000). Therefore, the occurrence of a hydrogen spillover effect may be involved in the observed process. © 2012 Springer Science+Business Media, LLC.
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Effect of rhodium traces on the reducibility of silica-supported iron particles
Bonnefille, Eric
2012-06-19
Fe/SiO 2 and Rh-Fe/SiO 2 catalysts with increasing Fe/Rh ratio have been prepared and characterized by TEM, XRD, oxygen adsorption and Mössbauer spectroscopy. It was confirmed that Fe/SiO 2 catalysts cannot be reduced under hydrogen flow, to more than 50 % whatever the temperature in the 200-500 °C range and shown that the presence of even a small amount of Rh (Fe/Rh ≤2,000) promoted the reduction of iron up to 85-95 %. This promoting effect also took place with a Fe/SiO 2 + Rh/SiO 2 physical mixture (Fe/Rh B2,000). Therefore, the occurrence of a hydrogen spillover effect may be involved in the observed process. © 2012 Springer Science+Business Media, LLC.
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Groundwater mixing at fracture intersections triggers massive iron-rich microbial mats
Bochet, O.; Le Borgne, T.; Bethencourt, L.; Aquilina, L.; Dufresne, A.; Pédrot, M.; Farasin, J.; Abbott, B. W.; Labasque, T.; Chatton, E.; Lavenant, N.; Petton, C.
2017-12-01
While most freshwater on Earth resides and flows in groundwater systems, these deep subsurface environments are often assumed to have little biogeochemical activity compared to surface environments. Here we report a massive microbial mat of iron-oxidizing bacteria, flourishing 60 meters below the surface, far below the mixing zone where most microbial activity is believed to occur. The abundance of microtubular structures in the mat hinted at the prevalence of of Leptothrix ochracea, but metagenomic analysis revealed a diverse consortium of iron-oxidizing bacteria dominated by unknown members of the Gallionellaceae family. This deep biogeochemical hot spot formed at the intersection of bedrock fractures, which maintain redox gradients by mixing water with different residence times and chemical compositions. Using measured fracture properties and hydrological conditions we developed a quantitative model to simulate the reactive zone where such deep hot spots could occur. While seasonal fluctuations are generally thought to decrease with depth, we found that meter-scale changes in water table level moved the depth of the reactive zone hundreds of meters because the microaerophilic threshold for ironoxidizers is highly sensitive to changes in mixing rates at fracture intersections. These results demonstrate that dynamic microbial communities can be sustained deep below the surface in bedrock fractures. Given the ubiquity of fractures at multiple scales in Earth's subsurface, such deep hot spots may strongly influence global biogeochemical cycles.
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Modelling and prediction of pig iron variables in the blast furnace
Energy Technology Data Exchange (ETDEWEB)
Saxen, H.; Laaksonen, M.; Waller, M. [Aabo Akademi, Turku (Finland). Heat Engineering Lab.
1996-12-31
The blast furnace, where pig iron for steelmaking is produced, is an extremely complicated process, with heat and mass transfer and chemical reactions between several phases. Very few direct measurements on the internal state are available in the operation of the process. A main problem in on-line analysis and modelling is that the state of the furnace may undergo spontaneous changes, which alter the dynamic behaviour of the process. Moreover, large internal disturbances frequently occur, which affect the product quality. The work in this research project focuses on a central problem in the control of the blast furnace process, i.e., short-term prediction of pig iron variables. The problem is of considerable importance for fuel economy, product quality, and for an optimal decision making in integrated steel plants. The operation of the blast furnace aims at producing a product (hot metal) with variables maintained on a stable level (close to their setpoints) without waste of expensive fuel (metallurgical coke). The hot metal temperature and composition affect the downstream (steelmaking) processes, so fluctuations in the pig iron quality must be `corrected` in the steel plant. The goal is to develop a system which predicts the evolution of the hot metal variables (temperature, chemical composition) during the next few taps, and that can be used for decision-making in the operation of the blast furnace. Because of the complicated behaviour of the process, it is considered important to include both deterministic and stochastic components in the modelling: Mathematical models, which on the basis of measurements describe the physical state of the process, and statistical (black-box) models will be combined in the system. Moreover, different models will be applied in different domains in order to capture structural changes in the dynamics of the process SULA 2 Research Programme; 17 refs.
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Modelling and prediction of pig iron variables in the blast furnace
Energy Technology Data Exchange (ETDEWEB)
Saxen, H; Laaksonen, M; Waller, M [Aabo Akademi, Turku (Finland). Heat Engineering Lab.
1997-12-31
The blast furnace, where pig iron for steelmaking is produced, is an extremely complicated process, with heat and mass transfer and chemical reactions between several phases. Very few direct measurements on the internal state are available in the operation of the process. A main problem in on-line analysis and modelling is that the state of the furnace may undergo spontaneous changes, which alter the dynamic behaviour of the process. Moreover, large internal disturbances frequently occur, which affect the product quality. The work in this research project focuses on a central problem in the control of the blast furnace process, i.e., short-term prediction of pig iron variables. The problem is of considerable importance for fuel economy, product quality, and for an optimal decision making in integrated steel plants. The operation of the blast furnace aims at producing a product (hot metal) with variables maintained on a stable level (close to their setpoints) without waste of expensive fuel (metallurgical coke). The hot metal temperature and composition affect the downstream (steelmaking) processes, so fluctuations in the pig iron quality must be `corrected` in the steel plant. The goal is to develop a system which predicts the evolution of the hot metal variables (temperature, chemical composition) during the next few taps, and that can be used for decision-making in the operation of the blast furnace. Because of the complicated behaviour of the process, it is considered important to include both deterministic and stochastic components in the modelling: Mathematical models, which on the basis of measurements describe the physical state of the process, and statistical (black-box) models will be combined in the system. Moreover, different models will be applied in different domains in order to capture structural changes in the dynamics of the process SULA 2 Research Programme; 17 refs.
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Iron requirements of infants and toddlers
DEFF Research Database (Denmark)
Domellöf, Magnus; Braegger, Christian; Campoy, Cristina
2014-01-01
Iron deficiency (ID) is the most common micronutrient deficiency worldwide and young children are a special risk group since their rapid growth leads to high iron requirements. Risk factors associated with a higher prevalence of iron deficiency anemia (IDA) include low birth weight, high cow's milk.......There is no evidence that iron supplementation of pregnant women improves iron status in their offspring in a European setting. Delayed cord clamping reduces the risk of iron deficiency. There is insufficient evidence to support general iron supplementation of healthy, European infants and toddlers of normal birth...... intake, low intake of iron-rich complementary foods, low socioeconomic status and immigrant status.The aim of this position paper is to review the field and provide recommendations regarding iron requirements in infants and toddlers, including those of moderately or marginally low birth weight...
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Domestic hot water storage: Balancing thermal and sanitary performance
International Nuclear Information System (INIS)
Armstrong, P.; Ager, D.; Thompson, I.; McCulloch, M.
2014-01-01
Thermal stratification within hot water tanks maximises the availability of stored energy and facilitates optimal use of both conventional and renewable energy sources. However, stratified tanks are also associated with the proliferation of pathogenic bacteria, such as Legionella, due to the hospitable temperatures that arise during operation. Sanitary measures, aimed at homogenising the temperature distribution throughout the tank, have been proposed; such measures reduce the effective energy storage capability that is otherwise available. Here we quantify the conflict that arises between thermodynamic performance and bacterial sterilisation within 10 real world systems. Whilst perfect stratification enhances the recovery of hot water and reduces heat losses, water samples revealed significant bacterial growth attributable to stratification (P<0.01). Temperature measurements indicated that users were exposed to potentially unsanitary water as a result. De-stratifying a system to sterilise bacteria led to a 19% reduction in effective hot water storage capability. Increasing the tank size to compensate for this loss would lead to an 11% increase in energy consumed through standing heat losses. Policymakers, seeking to utilise hot water tanks as demand response assets, should consider monitoring and control systems that prevent exposures to unsanitary hot water. - Highlights: • Domestic hot water tanks are a potential demand side asset for power networks. • A preference for bacterial growth in stratified hot water tanks has been observed. • Temperatures in base of electric hot water tanks hospitable to Legionella. • Potential exposures to unsanitary water observed. • De-stratifying a tank to sterilise leads to reduced energy storage capability
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Hot Deformation Behavior of Hot-Extruded AA7175 Through Hot Torsion Tests.
Lee, Se-Yeon; Jung, Taek-Kyun; Son, Hyeon-Woo; Kim, Sang-Wook; Son, Kwang-Tae; Choi, Ho-Joon; Oh, Sang-Ho; Lee, Ji-Woon; Hyun, Soong-Keun
2018-03-01
The hot deformation behavior of hot-extruded AA7175 was investigated with flow curves and processing maps through hot torsion tests. The flow curves and the deformed microstructures revealed that dynamic recrystallization (DRX) occurred in the hot-extruded AA7175 during hot working. The failure strain was highest at medium temperature. This was mainly influenced by the dynamic precipitation of fine rod-shaped MgZn2. The processing map determined the optimal deformation condition for the alloy during hot working.
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Evaluation of iron oxide nanoparticle micelles for Magnetic Particle Imaging (MPI) of thrombosis
Starmans, L.W.E.; Moonen, R.P.M.; Aussems-Custers, E.; Daemen, M.J.A.P.; Strijkers, G. J.; Nicolay, K.; Grüll, H.
2015-01-01
Magnetic particle imaging (MPI) is an emerging medical imaging modality that directly visualizes magnetic particles in a hot-spot like fashion. We recently developed an iron oxide nanoparticle-micelle (ION-Micelle) platform that allows highly sensitive MPI. The goal of this study was to assess the
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A Bacillus paralicheniformis Iron-Containing Urease Reduces Urea Concentrations in Rice Wine.
Liu, Qingtao; Chen, Yuqi; Yuan, Minglai; Du, Guocheng; Chen, Jian; Kang, Zhen
2017-09-01
Urease, a nickel-containing metalloenzyme, was the first enzyme to be crystallized and has a prominent position in the history of biochemistry. In the present study, we identified a nickel urease gene cluster, ureABCEFGDH , in Bacillus paralicheniformis ATCC 9945a and characterized it in Escherichia coli Enzymatic assays demonstrate that this oxygen-stable urease is also an iron-containing acid urease. Heterologous expression assays of UreH suggest that this accessory protein is involved in the transmembrane transportation of nickel and iron ions. Moreover, this iron-containing acid urease has a potential application in the degradation of urea in rice wine. The present study not only enhances our understanding of the mechanism of activation of urease but also provides insight into the evolution of metalloenzymes. IMPORTANCE An iron-containing, oxygen-stable acid urease from B. paralicheniformis ATCC 9945a with good enzymatic properties was characterized. This acid urease shows activities toward both urea and ethyl carbamate. After digestion with 6 U/ml urease, approximately 92% of the urea in rice wine was removed, suggesting that this urease has great potential in the food industry. Copyright © 2017 American Society for Microbiology.
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Directory of Open Access Journals (Sweden)
Meng eWang
2013-05-01
Full Text Available Nearly one-third of the world population, mostly women and children, suffer from iron malnutrition and its consequences, such as anemia or impaired mental development. Biofortification of rice, which is a staple crop for nearly half of the world’s population, can significantly contribute in alleviating iron deficiency. NFP rice (transgenic rice expressing nicotianamine synthase, ferritin and phytase genes has a more than six-fold increase in iron content in polished rice grains, resulting from the synergistic action of nicotianamine synthase (NAS and ferritin transgenes. We investigated iron homeostasis in NFP plants by analyzing the expression of 28 endogenous rice genes known to be involved in the homeostasis of iron and other metals, in iron-deficient and iron-sufficient conditions. RNA was collected from different tissues (roots, flag leaves, grains and at three developmental stages during grain filling. NFP plants showed increased sensitivity to iron-deficiency conditions and changes in the expression of endogenous genes involved in nicotianamine (NA metabolism, in comparison to their non-transgenic siblings. Elevated transcript levels were detected in NFP plants for several iron transporters. In contrast, expression of OsYSL2, which encodes a member of Yellow Stripe-like protein family, and a transporter of the NA-Fe(II complex was reduced in NFP plants under low iron conditions, indicating that expression of OsYSL2 is regulated by the endogenous iron status. Expression of the transgenes did not significantly affect overall iron homeostasis in NFP plants, which establishes the engineered push-pull mechanism as a suitable strategy to increase rice endosperm iron content.
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Ghorbanzadeh, N.; Lakzian, A.; Haghnia, G. H.; Karimi, A. R.
2014-12-01
Iron is an essential element for all organisms which plays a crucial role in important biochemical processes such as respiration and photosynthesis. Iron deficiency seems to be an important problem in many calcareous soils. Biological dissimilatory Fe(III) reduction increases iron availability through reduction of Fe(III) to Fe(II). The aim of this study was to isolate, identify and evaluate some bacterial isolates for their abilities to reduce Fe(III) in two calcareous soils. Three bacterial isolates were selected and identified from paddy soils by using 16S rRNA amplification and then inoculated to sterilized and non-sterilized calcareous soils in the presence and absence of glucose. The results showed that all isolates belonged to Bacillus genus and were capable of reducing Fe(III) to Fe(II) in vitro condition. The amount of Fe(III) reduction in sterilized calcareous soils was significantly higher when inoculated with PS23 isolate and Shewanella putrefaciens ( S. putrefaciens) (as positive control) compared to PS16 and PS11 isolates. No significant difference was observed between PS11 and PS16 isolates in the presence of indigenous microbial community. The results also revealed that glucose had a significant effect on Fe(III) reduction in the examined calcareous soil samples. The amount of Fe(III) reduction increased two-fold when soil samples were treated with glucose and inoculated by S. putrefaciens and PS23 in non-sterilized soils.
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Legault, Lisa; Gutsell, Jennifer N; Inzlicht, Michael
2011-12-01
Although prejudice-reduction policies and interventions abound, is it possible that some of them result in the precise opposite of their intended effect--an increase in prejudice? We examined this question by exploring the impact of motivation-based prejudice-reduction interventions and assessing whether certain popular practices might in fact increase prejudice. In two experiments, participants received detailed information on, or were primed with, the goal of prejudice reduction; the information and primes either encouraged autonomous motivation to regulate prejudice or emphasized the societal requirement to control prejudice. Ironically, motivating people to reduce prejudice by emphasizing external control produced more explicit and implicit prejudice than did not intervening at all. Conversely, participants in whom autonomous motivation to regulate prejudice was induced displayed less explicit and implicit prejudice compared with no-treatment control participants. We outline strategies for effectively reducing prejudice and discuss the detrimental consequences of enforcing antiprejudice standards.
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International Nuclear Information System (INIS)
Hawkins, C.; Treffry, A.; Mackey, J.; Williams, J.M.; Andrews, S.C.; Guest, J.R.; Harrison, P.M.
1996-01-01
This paper describes a preliminary investigation of the mechanisms of Fe(II) oxidation and storage of Fe(III) in the bacterioferritin of Escherichia coli (EcBFR). Using Moessbauer spectroscopy to examine the initial oxidation of iron by EcBFR it is confirmed that this ferritin exhibits 'ferroxidase' activity and is shown that dimeric and monomeric iron species are produced as intermediates. The characteristics of ferroxidase activity in EcBFR is compare d with those of human H-chain ferritin (HuHF) and discuss the different Moessbauer parameters of their dimeric iron with reference to the structures of their di-metal sites. In addition, it is presented preliminary findings suggesting that after an initial 'burst', the rate of oxidation is greatly reduced, possibly due to blockage of the ferroxidase centre by bound iron. A new component, not found in HuHF and probably representing a small cluster of Fe(III) atoms, is reported
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Pit morphology studies of iron and steel in alkaline chloride environment using EMPA technique
International Nuclear Information System (INIS)
Benjamin, S.E.; Sykes, J.M.
1993-01-01
A comparative study of iron and steel in stimulated alkaline chloride solutions showed that Swedish iron has better reproducibility in terms of pitting potentials as compared to ordinary hot rolled mild steel. This study was undertaken to reason this pitting behavior on the basis of number and the nature of inclusions present in both the metals. Electron probe microanalysis technique (EPMA) was utilised to contemplate the origin of pits, the solution chemistry of the pits and finally the nature of the rust product. (author)
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Hot Blade Cuttings for the Building Industries
DEFF Research Database (Denmark)
Brander, David; Bærentzen, Jakob Andreas; Evgrafov, Anton
2016-01-01
. The project aims to reduce the amount of manual labour as well as production time by applying robots to cut expanded polystyrene (EPS) moulds for the concrete to form doubly curved surfaces. The scheme is based upon the so-called Hot Wire or Hot Blade technology where the surfaces are essentially swept out...
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Plasma hot machining for difficult-to-cut materials, 1
International Nuclear Information System (INIS)
Kitagawa, Takeaki; Maekawa, Katsuhiro; Kubo, Akihiko
1987-01-01
Machinability of difficult-to-cut materials has been a great concern to manufacturing engineers since demands for new materials in the aerospace and nuclear industries are more and more increasing. The purpose of this study is to develop a hot machining to improve machinability of high hardness materials. A plasma arc is used for heating materials cut. The surface just after being heated is removed as a chip by tungsten carbide tools. The turning experiments of high hardness steels with aid of plasma arc heating show not only the decrease in cutting forces but also the following effectiveness: (1) The application of the plasma hot machining to the condition, under which a built-up edge (BUE) appears in turning 0.46%C steel, makes the BUE disappeared, bringing less flank wear. (2) In the case of 18%Mn steel cutting, deep groove wear on the end-cutting edge diminishes, and roughness of the machined surface is improved by the prevention from chatter. (3) Although the chilled cast iron has high hardness of above HB = 350, the plasma hot machining makes it possible to cut it with tungsten carbide tools having less chipping and flank wear. (author)
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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
corrosion product alteration, magnetite and hematite mainly (c). For that, an optimised method of H2 measure at weak pressure has been realised by gaseous phase chromatography coupled with a sensitive pressure captor. - H 2 + Fe 3+ magnetite → Fe 2+ solution + 2H + (c) The interest of this study is to determine and to understand the reactivity of one model microbe species, the ferric-reducing bacterium 'Schewanella oneidensis strain MR-1', on a Fe(0) corrosion and these corrosion products (magnetite, hematite mainly) in presence or not of clay minerals (bentonite MX80). The introduction of short-term experiments in the scattered environment (batch) over reactivity Iron-bacteria with or without clay mineral is here studied through a kinetic study of H 2 bio-consumed or product, chemical analysis in solution, and by use a crystallo-chemistry tool (XRD and SEM). The main results are bio-alteration of corrosion products with development of ferri-reducing bacterial community. This microbial alteration entails an increase of aqueous corrosion by consumption of corrosion products (passivation layer). In such condition, corrosion process could be reactivated. (authors)
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Method for reducing heat loss during injection of hot water into an oil stratum
Energy Technology Data Exchange (ETDEWEB)
Evgenev, A E; Kalashnikov, V N; Raiskii, Yu D
1968-07-01
A method is described for reduction of heat loss during the injection of hot water into an oil stratum. During the transportation of the hot water to the face of the bore holes, it has high-molecular polymers added to it. The high-molecular polymer may be guanidine or polyoxyethylene in the quantity of 0.01 to 0.03% by wt.
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Iron and genome stability: An update
International Nuclear Information System (INIS)
Prá, Daniel; Franke, Silvia Isabel Rech; Henriques, João Antonio Pêgas; Fenech, Michael
2012-01-01
Iron is an essential micronutrient which is required in a relatively narrow range for maintaining metabolic homeostasis and genome stability. Iron participates in oxygen transport and mitochondrial respiration as well as in antioxidant and nucleic acid metabolism. Iron deficiency impairs these biological pathways, leading to oxidative stress and possibly carcinogenesis. Iron overload has been linked to genome instability as well as to cancer risk increase, as seen in hereditary hemochromatosis. Iron is an extremely reactive transition metal that can interact with hydrogen peroxide to generate hydroxyl radicals that form the 8-hydroxy-guanine adduct, cause point mutations as well as DNA single and double strand breaks. Iron overload also induces DNA hypermethylation and can reduce telomere length. The current Recommended Dietary Allowances (RDA) for iron, according with Institute of Medicine Dietary Reference Intake (DRI), is based in the concept of preventing anemia, and ranges from 7 mg/day to 18 mg/day depending on life stage and gender. Pregnant women need 27 mg/day. The maximum safety level for iron intake, the Upper Level (UL), is 40–45 mg/day, based on the prevention of gastrointestinal distress associated to high iron intakes. Preliminary evidence indicates that 20 mg/day iron, an intake slightly higher than the RDA, may reduce the risk of gastrointestinal cancer in the elderly as well as increasing genome stability in lymphocytes of children and adolescents. Current dietary recommendations do not consider the concept of genome stability which is of concern because damage to the genome has been linked to the origin and progression of many diseases and is the most fundamental pathology. Given the importance of iron for homeostasis and its potential influence over genome stability and cancer it is recommended to conduct further studies that conclusively define these relationships.
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Iron and genome stability: An update
Energy Technology Data Exchange (ETDEWEB)
Pra, Daniel, E-mail: daniel_pra@yahoo.com [PPG em Promocao da Saude, Universidade de Santa Cruz do Sul (UNISC), Santa Cruz do Sul, RS (Brazil); PPG em Saude e Comportamento, Universidade Catolica de Pelotas, Pelotas, RS (Brazil); Franke, Silvia Isabel Rech [PPG em Promocao da Saude, Universidade de Santa Cruz do Sul (UNISC), Santa Cruz do Sul, RS (Brazil); Henriques, Joao Antonio Pegas [Instituto de Biotecnologia, Universidade de Caxias do Sul, Caxias do Sul, RS (Brazil); Fenech, Michael [CSIRO Food and Nutritional Sciences, Adelaide, SA (Australia)
2012-05-01
Iron is an essential micronutrient which is required in a relatively narrow range for maintaining metabolic homeostasis and genome stability. Iron participates in oxygen transport and mitochondrial respiration as well as in antioxidant and nucleic acid metabolism. Iron deficiency impairs these biological pathways, leading to oxidative stress and possibly carcinogenesis. Iron overload has been linked to genome instability as well as to cancer risk increase, as seen in hereditary hemochromatosis. Iron is an extremely reactive transition metal that can interact with hydrogen peroxide to generate hydroxyl radicals that form the 8-hydroxy-guanine adduct, cause point mutations as well as DNA single and double strand breaks. Iron overload also induces DNA hypermethylation and can reduce telomere length. The current Recommended Dietary Allowances (RDA) for iron, according with Institute of Medicine Dietary Reference Intake (DRI), is based in the concept of preventing anemia, and ranges from 7 mg/day to 18 mg/day depending on life stage and gender. Pregnant women need 27 mg/day. The maximum safety level for iron intake, the Upper Level (UL), is 40-45 mg/day, based on the prevention of gastrointestinal distress associated to high iron intakes. Preliminary evidence indicates that 20 mg/day iron, an intake slightly higher than the RDA, may reduce the risk of gastrointestinal cancer in the elderly as well as increasing genome stability in lymphocytes of children and adolescents. Current dietary recommendations do not consider the concept of genome stability which is of concern because damage to the genome has been linked to the origin and progression of many diseases and is the most fundamental pathology. Given the importance of iron for homeostasis and its potential influence over genome stability and cancer it is recommended to conduct further studies that conclusively define these relationships.
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Superoxide scavenging activity of pirfenidone-iron complex
International Nuclear Information System (INIS)
Mitani, Yoshihiro; Sato, Keizo; Muramoto, Yosuke; Karakawa, Tomohiro; Kitamado, Masataka; Iwanaga, Tatsuya; Nabeshima, Tetsuji; Maruyama, Kumiko; Nakagawa, Kazuko; Ishida, Kazuhiko; Sasamoto, Kazumi
2008-01-01
Pirfenidone (PFD) is focused on a new anti-fibrotic drug, which can minimize lung fibrosis etc. We evaluated the superoxide (O 2 ·- ) scavenging activities of PFD and the PFD-iron complex by electron spin resonance (ESR) spectroscopy, luminol-dependent chemiluminescence assay, and cytochrome c reduction assay. Firstly, we confirmed that the PFD-iron complex was formed by mixing iron chloride with threefold molar PFD, and the complex was stable in distillated water and ethanol. Secondary, the PFD-iron complex reduced the amount of O 2 ·- produced by xanthine oxidase/hypoxanthine without inhibiting the enzyme activity. Thirdly, it also reduced the amount of O 2 ·- released from phorbor ester-stimulated human neutrophils. PFD alone showed few such effects. These results suggest the possibility that the O 2 ·- scavenging effect of the PFD-iron complex contributes to the anti-fibrotic action of PFD used for treating idiopathic pulmonary fibrosis
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Ahmad, Ayyaz; Gu, Xiaogang; Li, Li; Lv, Shuguang; Xu, Yisheng; Guo, Xuhong
2015-11-01
Graphene oxide (GO) and nano-sized zero-valent iron-reduced graphene oxide (nZVI-rGO) composite were prepared. The GO and nZVI-rGO composite were characterized by transmission electron microscopy (TEM), Fourier transform infrared (FTIR), energy-dispersive spectroscopy (EDS), and Raman spectroscopy. The size of nZVI was about 6 nm as observed by TEM. The system of nZVI-rGO and persulfate (PS) was used for the degradation of trichloroethylene (TCE) in water, and showed 26.5% more efficiency as compared to nZVI/PS system. The different parameters were studied to determine the efficiency of nZVI-rGO to activate the PS system for the TCE degradation. By increasing the PS amount, TCE removal was also improved while no obvious effect was observed by varying the catalyst loading. Degradation was decreased as the TCE initial concentration was increased from 20 to 100 mg/L. Moreover, when initial solution pH was increased, efficiency deteriorated to 80%. Bicarbonate showed more negative effect on TCE removal among the solution matrix. To better understand the effects of radical species in the system, the scavenger tests were performed. The •SO4(-) and •O2(-) were predominant species responsible for TCE removal. The nZVI-rGO-activated PS process shows potential applications in remediation of highly toxic organic contaminants such as TCE present in the groundwater. Graphical abstract Persulfate activated by reduced graphene oxide and nano-sized zero-valent iron composite can be used for efficient degradation of trichloroethylene (TCE) in water.
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Extending hydraulic lifetime of iron walls
International Nuclear Information System (INIS)
Mackenzie, P.D.; Sivavec, T.M.; Horney, D.P.
1997-01-01
Iron walls for control of groundwaters contaminated with chlorinated solvents and reducible metals are becoming much more widely used and field studies of this technology have proven successful to date. However, there is still much uncertainty in predicting long-term performance. This work focuses on two factors affecting the lifetime of the iron media: plugging at the treatment zone entrance and precipitation in the bulk iron media. Plugging at the system entrance is due principally to dissolved oxygen in the incoming water and is an issue in aerobic aquifers or in ex-situ canister tests. In an in-situ treatment system, plugging would result in a dramatic reduction in flow through the iron zone. Designs to minimize plugging in field applications include use of larger iron particles and admixing sand of comparable size with the iron particles. Mineral precipitation in the bulk iron media can lead to porosity losses in the media, again reducing flow through the treatment zone. Decreases in reactivity of the iron media may also occur. The nature of the mineral precipitation and the factors that affect extent of mineral precipitation are examined by a variety of tools, including tracer tests, aqueous inorganic profiles, and surface analysis techniques. At short treatment times, measured porosity losses are due mainly to entrapment of a film of H 2 gas on the iron surfaces and also to Fe(OH) 2 precipitation. Over longer treatment times precipitation of Fe(OH) 2 and FeCO 3 in low carbonate waters and of Fe(OH) 2 , FeCO 3 and CaCO 3 in higher carbonate waters will begin to dominate porosity losses. Preliminary results of an on-going study to control pH in an iron zone by admixing iron sulfide with iron show no difference in extent of carbonate precipitation versus a 100% iron system, suggesting that these systems are supersaturated with respect to carbonate precipitation
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Directory of Open Access Journals (Sweden)
Hosny KM
2015-01-01
Full Text Available Khaled Mohamed Hosny,1,2 Zainy Mohammed Banjar,3 Amani H Hariri,4 Ali Habiballah Hassan5 1Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, King Abdulaziz University, Jeddah, Saudi Arabia; 2Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, Beni Suef University, Beni Suef, Egypt; 3Department of Clinical Biochemistry, Faculty of medicine, King Abdulaziz University, Jeddah, Saudi Arabia; 4Consultant Obstetrics and Gynecology, Hera Genaral Hospital, Makkah, Saudi Arabia; 5Department of Orthodontics, Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia Abstract: According to the World Health Organization, 46% of the world’s children suffer from anemia, which is usually treated with iron supplements such as ferrous sulfate. The aim of this study was to prepare iron as solid lipid nanoparticles, in order to find an innovative way for alleviating the disadvantages associated with commercially available tablets. These limitations include adverse effects on the digestive system resulting in constipation and blood in the stool. The second drawback is the high variability in the absorption of iron and thus in its bioavailability. Iron solid lipid nanoparticles (Fe-SLNs were prepared by hot homogenization/ultrasonication. Solubility of ferrous sulfate in different solid lipids was measured, and effects of process variables such as the surfactant type and concentration, homogenization and ultrasonication times, and charge-inducing agent on the particle size, zeta potential, and encapsulation efficiency were determined. Furthermore, in vitro drug release and in vivo pharmacokinetics were studied in rabbits. Results indicated that Fe-SLNs consisted of 3% Compritol 888 ATO, 1% Lecithin, 3% Poloxamer 188, and 0.2% dicetylphosphate, with an average particle size of 25 nm with 92.3% entrapment efficiency. In vivo pharmacokinetic study revealed more than fourfold enhanced bioavailability. In
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Patrick, T E; Goodwin, T L; Collins, J A; Wyche, R C; Love, B E
1972-04-01
A comparison of two types of scalders was conducted to determine their effectiveness in reducing bacterial contamination of poultry carcasses. A conventional hot-water scalder and a prototype model of a steam scalder were tested under commercial conditions. Total plate counts from steam-scalded birds were significantly lower than the counts of water-scalded birds immediately after scalding and again after picking. No differences in the two methods could be found after chilling. Coliform counts from steam-scalded birds were significantly lower than the counts from water-scalded birds immediately after scalding. No significant differences in coliform counts were detected when the two scald methods were compared after defeathering and chilling.
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Residential hot water distribution systems: Roundtablesession
Energy Technology Data Exchange (ETDEWEB)
Lutz, James D.; Klein, Gary; Springer, David; Howard, Bion D.
2002-08-01
Residential building practice currently ignores the lossesof energy and water caused by the poor design of hot water systems. Theselosses include: combustion and standby losses from water heaters, thewaste of water (and energy) while waiting for hot water to get to thepoint of use; the wasted heat as water cools down in the distributionsystem after a draw; heat losses from recirculation systems and thediscarded warmth of waste water as it runs down the drain. Severaltechnologies are available that save energy (and water) by reducing theselosses or by passively recovering heat from wastewater streams and othersources. Energy savings from some individual technologies are reported tobe as much as 30 percent. Savings calculations of prototype systemsincluding bundles of technologies have been reported above 50 percent.This roundtable session will describe the current practices, summarizethe results of past and ongoing studies, discuss ways to think about hotwater system efficiency, and point to areas of future study. We will alsorecommend further steps to reduce unnecessary losses from hot waterdistribution systems.
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Tussing-Humphreys, Lisa; Pustacioglu, Cenk; Nemeth, Elizabeta; Braunschweig, Carol
2012-01-01
Adequate iron availability is essential to human development and overall health. Iron is a key component of oxygen-carrying proteins, has a pivotal role in cellular metabolism, and is essential to cell growth and differentiation. Inadequate dietary iron intake, chronic and acute inflammatory conditions, and obesity are each associated with alterations in iron homeostasis. Tight regulation of iron is necessary because iron is highly toxic and human beings can only excrete small amounts through sweat, skin and enterocyte sloughing, and fecal and menstrual blood loss. Hepcidin, a small peptide hormone produced mainly by the liver, acts as the key regulator of systemic iron homeostasis. Hepcidin controls movement of iron into plasma by regulating the activity of the sole known iron exporter ferroportin-1. Downregulation of the ferroportin-1 exporter results in sequestration of iron within intestinal enterocytes, hepatocytes, and iron-storing macrophages reducing iron bioavailability. Hepcidin expression is increased by higher body iron levels and inflammation and decreased by anemia and hypoxia. Importantly, existing data illustrate that hepcidin may play a significant role in the development of several iron-related disorders, including the anemia of chronic disease and the iron dysregulation observed in obesity. Therefore, the purpose of this article is to discuss iron regulation, with specific emphasis on systemic regulation by hepcidin, and examine the role of hepcidin within several disease states, including iron deficiency, anemia of chronic disease, and obesity. The relationship between obesity and iron depletion and the clinical assessment of iron status will also be reviewed. PMID:22717199
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Hydroxyurea could be a good clinically relevant iron chelator.
Italia, Khushnooma; Colah, Roshan; Ghosh, Kanjaksha
2013-01-01
Our previous study showed a reduction in serum ferritin of β-thalassemia patients on hydroxyurea therapy. Here we aimed to evaluate the efficacy of hydroxyurea alone and in combination with most widely used iron chelators like deferiprone and deferasirox for reducing iron from experimentally iron overloaded mice. 70 BALB/c mice received intraperitonial injections of iron-sucrose. The mice were then divided into 8 groups and were orally given hydroxyurea, deferiprone or deferasirox alone and their combinations for 4 months. CBC, serum-ferritin, TBARS, sTfr and hepcidin were evaluated before and after iron overload and subsequently after 4 months of drug therapy. All animals were then killed. Iron staining of the heart and liver tissue was done using Perl's Prussian Blue stain. Dry weight of iron in the heart and liver was determined by atomic absorption spectrometry. Increased serum-ferritin, TBARS, hepcidin and dry weight of iron in the liver and heart showed a significant reduction in groups treated with iron chelators with maximum reduction in the group treated with a combination of deferiprone, deferasirox and hydroxyurea. Thus hydroxyurea proves its role in reducing iron from iron overloaded mice. The iron chelating effect of these drugs can also be increased if given in combination.
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Hydroxyurea could be a good clinically relevant iron chelator.
Directory of Open Access Journals (Sweden)
Khushnooma Italia
Full Text Available Our previous study showed a reduction in serum ferritin of β-thalassemia patients on hydroxyurea therapy. Here we aimed to evaluate the efficacy of hydroxyurea alone and in combination with most widely used iron chelators like deferiprone and deferasirox for reducing iron from experimentally iron overloaded mice. 70 BALB/c mice received intraperitonial injections of iron-sucrose. The mice were then divided into 8 groups and were orally given hydroxyurea, deferiprone or deferasirox alone and their combinations for 4 months. CBC, serum-ferritin, TBARS, sTfr and hepcidin were evaluated before and after iron overload and subsequently after 4 months of drug therapy. All animals were then killed. Iron staining of the heart and liver tissue was done using Perl's Prussian Blue stain. Dry weight of iron in the heart and liver was determined by atomic absorption spectrometry. Increased serum-ferritin, TBARS, hepcidin and dry weight of iron in the liver and heart showed a significant reduction in groups treated with iron chelators with maximum reduction in the group treated with a combination of deferiprone, deferasirox and hydroxyurea. Thus hydroxyurea proves its role in reducing iron from iron overloaded mice. The iron chelating effect of these drugs can also be increased if given in combination.
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Rukuni, Ruramayi; Knight, Marian; Murphy, Michael F; Roberts, David; Stanworth, Simon J
2015-10-20
Iron deficiency anaemia is a common problem in pregnancy despite national recommendations and guidelines for treatment. The aim of this study was to appraise the evidence against the UK National Screening Committee (UKNSC) criteria as to whether a national screening programme could reduce the prevalence of iron deficiency anaemia and/or iron deficiency in pregnancy and improve maternal and fetal outcomes. Search strategies were developed for the Cochrane library, Medline and Embase to identify evidence relevant to UK National Screening Committee (UKNSC) appraisal criteria which cover the natural history of iron deficiency and iron deficiency anaemia, the tests for screening, clinical management and evidence of cost effectiveness. Many studies evaluated haematological outcomes of anaemia, but few analysed clinical consequences. Haemoglobin and ferritin appeared the most suitable screening tests, although future options may follow recent advances in understanding iron homeostasis. The clinical consequences of iron deficiency without anaemia are unknown. Oral and intravenous iron are effective in improving haemoglobin and iron parameters. There have been no trials or economic evaluations of a national screening programme for iron deficiency anaemia in pregnancy. Iron deficiency in pregnancy remains an important problem although effective tests and treatment exist. A national screening programme could be of value for early detection and intervention. However, high quality studies are required to confirm whether this would reduce maternal and infant morbidity and be cost effective.
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Baek, Gahyun; Kim, Jaai; Shin, Seung Gu; Lee, Changsoo
2016-01-01
Although anaerobic digestion (AD) is a widely used option to manage waste activated sludge (WAS), there are some drawbacks related to its slow reaction rate and low energy productivity. This study examined an anaerobic WAS digester, augmented with an iron-reducing microbial consortium, relative to changes in microbial community structure and process performance at decreasing hydraulic retention times (HRTs) of 20 to 10 days. The enhanced methanation performance (approximately 40 % increase in methane yield) by the bioaugmentation was sustained until the HRT was decreased to 12.5 days, under Fe(3+)-rich conditions (ferric oxyhydroxide, 20 mM Fe). Enhanced iron-reducing activity was evidenced by the increased Fe(2+) to total Fe ratio maintained above 50 % during the stable operational phases. A further decrease in HRT to 10 days resulted in a significant performance deterioration, along with a drop in the Fe(2+) to total Fe ratio to bacteria (IRBs) was identified by denaturing gradient gel electrophoresis (DGGE), with Spirochaetaceae- and Thauera-related organisms being dominant members, and clear dominance shifts among them with respect to decrease in HRT were observed. Lowering HRT led to evident shifts in bacterial community structure likely associated with washout of IRBs, leading to decreases in iron respiration activity and AD performance at a lower HRT. The bacterial community structure shifted dynamically over phases, and the community transitions correlated well with the changes in process performance. Overall, the combined biostimulation and bioaugmentation investigated in this study proved effective for enhanced methane recovery from anaerobic WAS digestion, which suggests an interesting potential for high-rate AD.
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Hot-Dip Coating of Lead-free Aluminum on Steel Substrates with Ultrasonic Vibration
Institute of Scientific and Technical Information of China (English)
无
2008-01-01
Hot-dip coating has been practically employed in manufacturing zinc alloy coated steel sheets. However, it is difficult to coat aluminum alloy on a bulky steel substrate without sufficient preheating, because a rapidly solidified layer containing gas babbles is formed on a substrate surface. A variety of iron-aluminides are also formed at the interface of a steel and aluminum hot-dip coating system, which is the main difficulty in joining of steel with aluminum. Ultrasonic vibration was applied to a steel substrate during hot-dip coating of aluminum alloy to control a rapidly solidified layer and a brittle reaction layer. Hot dipping of columnar steel substrates into molten aluminum alloy (Al-2.7 mass fraction Si-4.6 mass fraction Sn) was carried out through the use of a Langevin oscillator with resonant frequency of 19.5 kHz. The application of ultrasonic vibration is quite effective to control a rapidly solidified layer and a surface oxide layer from a substrate surface by the sonocapillary effect based on a cavitation phenomenon, so that the intimate contact is achieved at the beginning of hot-dip coating. The application of ultrasonic vibration to hot-dipping is effective to control a reaction layer with less than 5μm in thickness. An impact test exhibits that the good adhesive strength is approved in hot-dipped aluminum coatings with a thin reaction layer of approximately 5μm.
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Myelodysplastic syndromes and the role of iron overload.
Harvey, R Donald
2010-04-01
The epidemiology of myelodysplastic syndromes (MDS) and iron overload, recent clinical findings that highlight the importance of actively managing iron overload, and recommendations for initiating and maintaining iron chelation therapy (ICT) are summarized. MDS are a variety of hematological disorders with differing time courses. Disease morbidities are primarily due to cytopenias and evolution to acute myeloid leukemia. Iron overload is a serious complication in patients with MDS due to the long-term use of red blood cell transfusions in patients with symptomatic anemia. Clinical consequences of iron overload include end-organ damage and dysfunction, an increased frequency of transplant-related complications, and reduced survival rates. To prevent these complications, recommendations for initiating and maintaining ICT should be followed by clinicians caring for patients with MDS and iron overload. As current therapeutic options for patients with MDS do not always reduce the transfusion burden, many patients will still need long-term transfusion therapy. Strategies for the management of iron overload in MDS should be considered early in the disease course and in appropriate patients in order to prevent negative clinical outcomes associated with excessive iron accumulation.
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International Nuclear Information System (INIS)
Uematsu, Y.; Tokaji, K.; Nishigaki, K.; Okajima, D.; Ogasawara, M.
2010-01-01
The cast iron with spheroidal vanadium carbides dispersed within martensitic-matrix microstructure was developed as a die material due to its high hardness. In order to achieve high performances of dies, not only the hardness but also the mechanical properties such as fracture toughness and fatigue crack propagation (FCP) resistance should be improved. In this paper, hot isostatic pressing (HIP) or forging was applied to the cast iron to improve mechanical properties, and the fracture behaviour, such as flexural strength, fracture toughness and FCP, was studied. The average flexural strength was reduced by forging because of the enhanced notch sensitivity due to the increase in the hardness. The fracture toughness was not affected by HIP nor forging while its scatter was significantly reduced by both post-treatments. The intrinsic FCP resistance taking account of crack closure was the same regardless of the application of HIP or forging, indicating that a slight change in the microstructure resulting from both treatments and the presence of casting defects exerted little influence on FCP behaviour. It could be concluded that both HIP and forging could improve the hardness of the material, while fracture toughness and FCP resistance were maintained.
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Properties shaping and repair of selected types of cast iron
Directory of Open Access Journals (Sweden)
J. Szajnar
2007-04-01
Full Text Available The paper presents research results of twofold use of TIG - Tungsten Inert Gas also known as GTA - Gas Tungsten Arc. First is surfacing by welding on cold and hot-cold to repair chromium cast iron with chromium content about 15%. Second is remelting with electric arc of selected gray (with pearlitic matrix and ductile (with ferritic-pearlitic matrix cast iron. Repair of cast iron elements was realized in order to cut out a casting defects. Defects decrease a usability of castings for constructional application and increase a manufacturing costs. Application of surface heat treatment guarantees mechanical properties i.e. hardness and wear resistance improvement. The result of investigations show possibility of castings repair by put on defects a good quality padding welds, which have comparable properties with base material. Use of electric arc surface heat treatment resulted in increase of hardness and wear resistance, which was measured on the basis of ASTM G 65 - 00 standard.
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Radiation-induced synthesis of gold, iron-oxide composite nanoparticles
International Nuclear Information System (INIS)
Seino, Satoshi; Yamamoto, Takao; Nakagawa, Takashi; Kinoshita, Takuya; Kojima, Takao; Taniguchi, Ryoichi; Okuda, Shuichi
2007-01-01
Composite nanoparticles consisting of magnetic iron oxide nanoparticles and gold nanoparticles were synthesized using gamma-rays or electron beam. Ionizing irradiation induces the generation of reducing species inside the aqueous solution, and gold ions are reduced to form metallic Au nanoparticles. The size of Au nanoparticles depended on the dose rate and the concentration of support iron oxide. The gold nanoparticles on iron oxide nanoparticles selectively adsorb biomolecules via Au-S bonding. By using magnetic property of the support iron oxide nanoparticles, the composite nanoparticles are expected as a new type of magnetic nanocarrier for biomedical applications. (author)
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Directory of Open Access Journals (Sweden)
Y. C. Eeu
2013-01-01
Full Text Available Polypyrrole (PPy was reinforced with reduced graphene oxide (RGO and iron oxide to achieve electrochemical stability and enhancement. The ternary nanocomposite film was prepared using a facile one-pot chronoamperometry approach, which is inexpensive and experimentally friendly. The field emission scanning electron microscopy (FESEM image shows a layered morphology of the ternary nanocomposite film as opposed to the dendritic structure of PPy, suggesting hybridization of the three materials during electrodeposition. X-ray diffraction (XRD profile shows the presence of Fe2O3 in the ternary nanocomposite. Cyclic voltammetry (CV analysis illustrates enhanced current for the nanocomposite by twofold and fourfold compared to its binary (PPy/RGO and individual (PPy counterparts, respectively. The ternary nanocomposite film exhibited excellent specific capacitance retention even after 200 cycles of charge/discharge.
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Solar 'hot spots' are still hot
Bai, Taeil
1990-01-01
Longitude distributions of solar flares are not random but show evidence for active zones (or hot spots) where flares are concentrated. According to a previous study, two hot spots in the northern hemisphere, which rotate with a synodic period of about 26.72 days, produced the majority of major flares, during solar cycles 20 and 21. The more prominent of these two hot spots is found to be still active during the rising part of cycle 22, producing the majority of northern hemisphere major flares. The synodic rotation period of this hot spot is 26.727 + or - 0.007 days. There is also evidence for hot spots in the southern hemisphere. Two hot spots separated by 180 deg are found to rotate with a period of 29.407 days, with one of them having persisted in the same locations during cycles 19-22 and the other, during cycles 20-22.
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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...
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Management of Iron Deficiency Anemia
Jimenez, Kristine; Kulnigg-Dabsch, Stefanie
2015-01-01
Anemia affects one-fourth of the world’s population, and iron deficiency is the predominant cause. Anemia is associated with chronic fatigue, impaired cognitive function, and diminished well-being. Patients with iron deficiency anemia of unknown etiology are frequently referred to a gastroenterologist because in the majority of cases the condition has a gastrointestinal origin. Proper management improves quality of life, alleviates the symptoms of iron deficiency, and reduces the need for blood transfusions. Treatment options include oral and intravenous iron therapy; however, the efficacy of oral iron is limited in certain gastrointestinal conditions, such as inflammatory bowel disease, celiac disease, and autoimmune gastritis. This article provides a critical summary of the diagnosis and treatment of iron deficiency anemia. In addition, it includes a management algorithm that can help the clinician determine which patients are in need of further gastrointestinal evaluation. This facilitates the identification and treatment of the underlying condition and avoids the unnecessary use of invasive methods and their associated risks. PMID:27099596
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Glinz, Dominik; Wegmüller, Rita; Ouattara, Mamadou; Diakité, Victorine G; Aaron, Grant J; Hofer, Lorenz; Zimmermann, Michael B; Adiossan, Lukas G; Utzinger, Jürg; N'Goran, Eliézer K; Hurrell, Richard F
2017-07-14
Iron deficiency anemia (IDA) is a major public health problem in sub-Saharan Africa. The efficacy of iron fortification against IDA is uncertain in malaria-endemic settings. The objective of this study was to evaluate the efficacy of a complementary food (CF) fortified with sodium iron EDTA (NaFeEDTA) plus either ferrous fumarate (FeFum) or ferric pyrophosphate (FePP) to combat IDA in preschool-age children in a highly malaria endemic region. This is a secondary analysis of a nine-month cluster-randomized controlled trial conducted in south-central Côte d'Ivoire. 378 children aged 12-36 months were randomly assigned to no food intervention ( n = 125; control group), CF fortified with 2 mg NaFeEDTA plus 3.8 mg FeFum for six days/week ( n = 126; FeFum group), and CF fortified with 2 mg NaFeEDTA and 3.8 mg FePP for six days/week ( n = 127; FePP group). The outcome measures were hemoglobin (Hb), plasma ferritin (PF), iron deficiency (PF anemia (Hb iron deficiency with or without anemia ( p = 0.068). IDA prevalence sharply decreased in the FeFum (32.8% to 1.2%, p anemia. These data indicate that, despite the high endemicity of malaria and elevated inflammation biomarkers (C-reactive protein or α-1-acid-glycoprotein), IDA was markedly reduced by provision of iron fortified CF to preschool-age children for 9 months, with no significant differences between a combination of NaFeEDTA with FeFum or NaFeEDTA with FePP. However, there was no overall effect on anemia, suggesting most of the anemia in this setting is not due to ID. This trial is registered at clinicaltrials.gov (NCT01634945).
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International Nuclear Information System (INIS)
Starosvetsky, J.; Kamari, R.; Farber, Y.; Bilanović, D.; Armon, R.
2016-01-01
Highlights: • The present study demonstrated the high reductive capacity of both strains: the collection S. oneidensis and the wild strain Geobacter spp. (soil isolate). • The experimental strains were successful in Fe 3+ reduction for both states: soluble and crystalline (originally prepared from rust). • Rust dissolution can be improved by: addition of AFC at low concentration (0.2 g/l), increasing bacterial initial inoculum and rust reactive surface. • Both experimental IRB strains were able to completely remove previously formed rust on carbon steel coupons. • Additional results (not showed) revealed that culture S. oneidensis and the environmental isolate Geobacter spp., apparently have a different mechanism of iron reduction that requires further study. - Abstract: Iron reducing bacteria (IRB), to be used in rust dissolution and removal, have been isolated and enriched from different environmental sources. Comparative measurements revealed that a soil isolate (Geobacter sulfurreducens sp.) had the highest reductive activity equivalent to Shewanella oneidensis (strain CIP 106686, pure culture). Both reductive microorganisms can use Fe 3+ ions as electron acceptors from soluble as well as from crystalline sources. In nutrient medium containing soluble Fe 3+ , the highest reductive activity obtained for G. sulfurreducens sp. and S. oneidensis was 93 and 97% respectively. Successful removal of rust from carbon steel coupons has been achieved with both experimental bacteria.
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Energy Technology Data Exchange (ETDEWEB)
Kim, Ki-Hwan; Gohier, Aurélien; Bourée, Jean Eric; Châtelet, Marc; Cojocaru, Costel-Sorin, E-mail: costel-sorin.cojocaru@polytechnique.edu
2015-01-30
The effect of atomic hydrogen assisted pre-treatment on the growth of vertically aligned carbon nanotubes using hot-filament chemical vapor deposition was investigated. Iron nanoparticle catalysts were formed on an aluminum oxide support layer by spraying of iron chloride salt solutions as catalyst precursor. It is found that pre-treatment time and process temperature tune the density as well as the shape and the structure of the grown carbon nanotubes. An optimum pre-treatment time can be found for the growth of long and well aligned carbon nanotubes, densely packed to each other. To provide insight on this behavior, the iron catalytic nanoparticles formed after the atomic hydrogen assisted pre-treatment were analyzed by atomic force microscopy. The relations between the size and the density of the as-formed catalyst and the as-grown carbon nanotube's structure and density are discussed. - Highlights: • Effect of the atomic hydrogen assisted pre-treatment on the growth of VACNT using hot-filament CVD. • Pre-treatment time and process temperature tune the density, the shape and the structure of the CNTs. • Correlations between size and density of the as-formed catalyst and the CNT’s structure and density. • Carbon nanotubes synthesized at low temperature down to 500 °C using spayed iron chloride salts. • Density of the CNT carpet adjusted by catalytic nanoparticle engineering.
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International Nuclear Information System (INIS)
Bai, T.
1990-01-01
Longitude distributions of solar flares are not random but show evidence for active zones (or hot spots) where flares are concentrated. According to a previous study, two hot spots in the northern hemisphere, which rotate with a synodic period of about 26.72 days, produced the majority of major flares, during solar cycles 20 and 21. The more prominent of these two hot spots is found to be still active during the rising part of cycle 22, producing the majority of northern hemisphere major flares. The synodic rotation period of this hot spot is 26.727 + or - 0.007 days. There is also evidence for hot spots in the southern hemisphere. Two hot spots separated by 180 deg are found to rotate with a period of 29.407 days, with one of them having persisted in the same locations during cycles 19-22 and the other, during cycles 20-22. 14 refs
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Freezing Range, Melt Quality, and Hot Tearing in Al-Si Alloys
Uludağ, Muhammet; Çetin, Remzi; Dispinar, Derya
2018-02-01
In this study, three different aluminum-silicon alloys (A356, A413, and A380) that have different solidification morphology and solidification ranges were examined with an aim to evaluate the hot tearing susceptibility. T-shape mold and Constrained Rod Casting (CRC) mold were used for the characterization. Reduced Pressure Test (RPT) was used to quantify the casting quality by measuring bifilm index. It was found that bifilm index and solidification range have an important role on the hot tearing formation. As it is known, bifilms can cause porosity and in this case, it was shown that porosity formed by bifilms decreased hot tearing tendency. As the freezing range of alloy increases, bifilms find the time to unravel that reduces hot tearing. However, for eutectic alloy (A413), due to zero freezing range, regardless of bifilm content, hot tearing was never observed. A380.1 alloy had the highest tendency for hot tearing due to having the highest freezing range among the alloys investigated in this work.
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Application of welding technology TIG to cast iron repair
Directory of Open Access Journals (Sweden)
J. Szajnar
2008-03-01
Full Text Available Rcpnir nT cnst imn clcrncnts rcaEi7c in ordcr to cut out a sltpcrficial casting dcfcc~s, Dcrccis clccrcasc ;z usahiliny nt ca~rings torconsin~ciionaal pplication m d incrcasc a manufacturing costs. Thc pnpcr prcsclrls rcscarch rcsufts or itsc o r '1'IG - Tun~stcnI ncn Gas alsokncwn RS GTA - Gas Tunpstcn Arc surfacin: hy wclding on colt1 and half-hot to rcpnls chrninil~m cnsr iron EN-GJN-XCrlS withcliro~niurnc ontcnt nhout 3 5% and nodular ({vi~hF crritic-pcarli~ic matrix cast iron EN-GJS-500-7. Thc rcsttl~o r invcsiigations showpossibility of cns~ings rcpais hy put on derccts a good quality padding wclds, which havc compamhlc nr hcricr propcrtlcs than hnsc~naicrial.
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Energy Technology Data Exchange (ETDEWEB)
Haddad, Paula S. [Laboratorio Nacional de Luz Sincrotron (LNLS), Caixa Postal 6192, CEP 13083-970, Campinas-SP (Brazil)], E-mail: pferreira@lnls.br; Martins, Tatiana M. [Laboratorio Nacional de Luz Sincrotron (LNLS), Caixa Postal 6192, CEP 13083-970, Campinas-SP (Brazil); Instituto de Fisica Gleb Wataghin (IFGW), Universidade Estadual de Campinas (UNICAMP), Caixa Postal 6165, CEP 13083-970, Campinas-SP (Brazil); D' Souza-Li, Lilia [Laboratorio de Endocrinologia Pediatrica da Faculdade de Ciencias Medicas (FCM), UNICAMP, Caixa Postal 6111, CEP 13083-970, Campinas-SP (Brazil); Li, Li M. [Departamento de Neurologia da FCM, UNICAMP, Caixa Postal 6111, CEP 13083-970, Campinas-SP (Brazil); Metze, Konradin; Adam, Randall L. [Grupo interdisciplinar ' Patologia Analitica Celular' , Departamento de Anatomia Patologica da FCM, UNICAMP, Caixa Postal 6111, CEP 13083-970, Campinas-SP (Brazil); Knobel, Marcelo [Instituto de Fisica Gleb Wataghin (IFGW), Universidade Estadual de Campinas (UNICAMP), Caixa Postal 6165, CEP 13083-970, Campinas-SP (Brazil); Zanchet, Daniela [Laboratorio Nacional de Luz Sincrotron (LNLS), Caixa Postal 6192, CEP 13083-970, Campinas-SP (Brazil)
2008-05-01
The present work reports the synthesis, characterization and properties of magnetic iron oxide nanoparticles for biomedical applications, correlating the nanoscale tunabilities in terms of size, structure, and magnetism. Magnetic nanoparticles in different conditions were prepared through thermal decomposition of Fe(acac){sub 3} in the presence of 1,2 hexadecanodiol (reducing agent) and oleic acid and oleylamine (ligands) in a hot organic solvent. The 2,3-dimercaptosuccinic acid (DMSA) was exchanged onto the nanocrystal surface making the particles stable in water. Nanoparticles were characterized by X-ray diffraction (XRD) measurements, small angle X-ray scattering (SAXS) and transmission electron microscopy (TEM). Preliminary tests of incorporation of these nanoparticles in cells and their magnetic resonance image (MRI) were also carried out. The magnetization characterizations were made by isothermal magnetic measurements.
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Modern Cast Irons in Chemical Engineering
1934-11-09
fl’ceew. T I SOCIETY OF CHEMICAL INDUSTRY CHEMICAL ENGINEERING GROUP MODERN CAST IRONS IN CHEMICAL ENGINEERING By J. G. PEARCE, M.Sc., F.Inst.P...CAST IRONS IN CHEMICAL ENGINEERING By J. G. PEARCE, M.Sc., F.Inst.P., M.I.E.E.* INTRODUCTION to chemical or thermal resistance. Small blow-holes Any...consideration of modern cast irons in chemical seldom appear to reduce the mechanical strength of engineering should strictly be prefaced by a definition
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DEFF Research Database (Denmark)
Hannibal, Sara Stefansen
2016-01-01
HOT samler og formidler 21 literacykyndiges bud på, hvad der er hot, og hvad der bør være hot inden for literacy – og deres begrundelser for disse bud.......HOT samler og formidler 21 literacykyndiges bud på, hvad der er hot, og hvad der bør være hot inden for literacy – og deres begrundelser for disse bud....
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Microstructure Engineering in Hot Strip Mills, Part 1 of 2: Integrated mathematical Model
Energy Technology Data Exchange (ETDEWEB)
J.K. Brimacombe; I.V. Samaraseker; E.B. Hawbolt; T.R. Meadowcroft; M. Militzer; W.J. Pool; D.Q. Jin
1998-09-30
This report describes the work of developing an integrated model used to predict the thermal history, deformation, roll forces, microstructural evaluation and mechanical properties of steel strip in a hot-strip mill. This achievement results from a join research effort that is part of the American Iron and Steel Institute's (AISI) Advanced Process Control Program, a collaboration between the U.S. DOE and fifteen North American steel makers.
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Pompano, Laura M; Haas, Jere D
2017-12-01
Background: Despite its known detrimental effects, iron deficiency remains the most common micronutrient deficiency in the world. Many interventions that aim to improve iron status involve physically active populations. Intense aerobic exercise training negatively affects iron status; however, the impact of regular moderate aerobic exercise on the effectiveness of iron supplementation remains unclear. Objective: This study aimed to determine whether aerobic training modifies the assessment of the effectiveness of iron supplementation in improving conventional iron status measures. Design: Seventy-two iron-depleted, nonanemic Chinese women [serum ferritin (sFer) 110 g/L] were included in an 8-wk, partially blinded, randomized controlled trial with a 2 × 2 factorial design including iron supplements (42 mg elemental Fe/d) or placebo and aerobic training (five 25-min sessions/wk at 75-85% of maximum heart rate) or no training. Linear mixed models were used to evaluate the relation between supplement type, training, and changes in iron status over time, measured by sFer, hemoglobin, soluble transferrin receptor (sTfR), and estimated total body iron. Results: After treatment, both the iron-supplemented trained and untrained groups showed significantly improved sFer, sTfR, and body iron values compared with either of the placebo groups. Similarly, trained participants had significantly higher aerobic fitness measures than untrained participants. Training modified the sFer response to supplementation (training by supplement interaction, P = 0.07), with the iron-supplemented trained group having significantly lower sFer than the iron-supplemented untrained group at week 8 (mean ± SD: 31.8 ± 13.5 and 47.6 ± 15.7 μg/L, respectively; P = 0.042), whereas there was no significant difference between the placebo trained and untrained groups (21.3 ± 12.2 and 20.3 ± 7.0 μg/L, respectively; P = 1.00). Conclusions: Regular aerobic training reduces the apparent effectiveness
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Dinitrogen binding and cleavage by multinuclear iron complexes.
McWilliams, Sean F; Holland, Patrick L
2015-07-21
The iron-molybdenum cofactor of nitrogenase has unprecedented coordination chemistry, including a high-spin iron cluster called the iron-molybdenum cofactor (FeMoco). Thus, understanding the mechanism of nitrogenase challenges coordination chemists to understand the fundamental N2 chemistry of high-spin iron sites. This Account summarizes a series of studies in which we have synthesized a number of new compounds with multiple iron atoms, characterized them using crystallography and spectroscopy, and studied their reactions in detail. These studies show that formally iron(I) and iron(0) complexes with three- and four-coordinate metal atoms have the ability to weaken and break the triple bond of N2. These reactions occur at or below room temperature, indicating that they are kinetically facile. This in turn implies that iron sites in the FeMoco are chemically reasonable locations for N2 binding and reduction. The careful evaluation of these compounds and their reaction pathways has taught important lessons about what characteristics make iron more effective for N2 activation. Cooperation of two iron atoms can lengthen and weaken the N-N bond, while three working together enables iron atoms to completely cleave the N-N bond to nitrides. Alkali metals (typically introduced into the reaction as part of the reducing agent) are thermodynamically useful because the alkali metal cations stabilize highly reduced complexes, pull electron density into the N2 unit, and make reduced nitride products more stable. Alkali metals can also play a kinetic role, because cation-π interactions with the supporting ligands can hold iron atoms near enough to one another to facilitate the cooperation of multiple iron atoms. Many of these principles may also be relevant to the iron-catalyzed Haber-Bosch process, at which collections of iron atoms (often promoted by the addition of alkali metals) break the N-N bond of N2. The results of these studies teach more general lessons as well. They
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Effects of iron and multimicronutrient supplementation on geophagy
DEFF Research Database (Denmark)
Nchito, Mbiko; Geissler, P Wenzel; Mubila, Likezo
2004-01-01
Geophagy has been associated with iron deficiency and anaemia, but no causal relationship has been established. To clarify this, we conducted a two-by-two factorial randomised, controlled trial on the effect of iron and multimicronutrient supplementation on geophagy in Zambian schoolchildren...... was prevalent and associated with iron deficiency, but iron supplementation had no effects on geophageous behaviour. Geophagy could be a copied behaviour and the association between geophagy and iron deficiency due to impaired iron absorption following earth eating....... followed-up. In bivariate analysis, non-iron supplementation reduced the prevalence of geophagy more than iron supplementation did, but this was not confirmed in the multiple logistic regression analysis. Multimicronutrients had no effect on either geophagy prevalence or earth intake. Geophagy...
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Gloaguen, Frederic
2016-01-19
Synthetic models of the active site of iron-iron hydrogenases are currently the subjects of numerous studies aimed at developing H2-production catalysts based on cheap and abundant materials. In this context, the present report offers an electrochemist's view of the catalysis of proton reduction by simple binuclear iron(I) thiolate complexes. Although these complexes probably do not follow a biocatalytic pathway, we analyze and discuss the interplay between the reduction potential and basicity and how these antagonist properties impact the mechanisms of proton-coupled electron transfer to the metal centers. This question is central to any consideration of the activity at the molecular level of hydrogenases and related enzymes. In a second part, special attention is paid to iron thiolate complexes holding rigid and unsaturated bridging ligands. The complexes that enjoy mild reduction potentials and stabilized reduced forms are promising iron-based catalysts for the photodriven evolution of H2 in organic solvents and, more importantly, in water.
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HotRegion: a database of predicted hot spot clusters.
Cukuroglu, Engin; Gursoy, Attila; Keskin, Ozlem
2012-01-01
Hot spots are energetically important residues at protein interfaces and they are not randomly distributed across the interface but rather clustered. These clustered hot spots form hot regions. Hot regions are important for the stability of protein complexes, as well as providing specificity to binding sites. We propose a database called HotRegion, which provides the hot region information of the interfaces by using predicted hot spot residues, and structural properties of these interface residues such as pair potentials of interface residues, accessible surface area (ASA) and relative ASA values of interface residues of both monomer and complex forms of proteins. Also, the 3D visualization of the interface and interactions among hot spot residues are provided. HotRegion is accessible at http://prism.ccbb.ku.edu.tr/hotregion.
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Iron plaque decreases cadmium accumulation in Oryza sativa L. and serves as a source of iron.
Sebastian, A; Prasad, M N V
2016-11-01
Cadmium (Cd) contamination occurs in paddy soils; hence it is necessary to reduce Cd content of rice. Application and mode of action of ferrous sulphate in minimizing Cd in rice was monitored in the present study. Pot culture with Indian rice variety Swarna (MTU 7029) was maintained in Cd-spiked soil containing ferrous sulphates, which is expected to reduce Cd accumulation in rice. Responses in rhizosphere pH, root surface, metal accumulation in plant and molecular physiological processes were monitored. Iron plaque was induced on root surfaces after FeSO4 application and the amount of Fe in plaque reduced with increases in Cd in the soil. Rhizosphere pH decreased during plaque formation and became more acidic due to secretion of organic acids from the roots under Cd treatment. Moreover, iron chelate reductase activity increased with Cd treatment, but in the absence of Cd, activity of this enzyme increased in plaque-induced plants. Cd treatment caused expression of OsYSL18, whereas OsYSL15 was expressed only in roots without iron plaque. Fe content of plants increased during plaque formation, which protected plants from Cd-induced Fe deficiency and metal toxicity. This was corroborated with increased biomass, chlorophyll content and quantum efficiency of photo-synthesis among plaque-induced plants. We conclude that ferrous sulphate-induced iron plaque prevents Cd accumulation and Fe deficiency in rice. Iron released from plaque via organic acid mediated dissolution during Cd stress. © 2016 German Botanical Society and The Royal Botanical Society of the Netherlands.
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Hepatic iron overload: Quantitative MR imaging
International Nuclear Information System (INIS)
Gomori, J.M.; Horev, G.; Tamary, H.; Zandback, J.; Kornreich, L.; Zaizov, R.; Freud, E.; Krief, O.; Ben-Meir, J.; Rotem, H.
1991-01-01
Iron deposits demonstrate characteristically shortened T2 relaxation times. Several previously published studies reported poor correlation between the in vivo hepatic 1/T2 measurements made by means of midfield magnetic resonance (MR) units and the hepatic iron content of iron-overloaded patients. In this study, the authors assessed the use of in vivo 1/T2 measurements obtained by means of MR imaging at 0.5 T using short echo times (13.4 and 30 msec) and single-echo-sequences as well as computed tomographic (CT) attenuation as a measure of liver iron concentration in 10 severely iron-overloaded patients with beta-thalassemia major. The iron concentrations in surgical wedge biopsy samples of the liver, which varied between 3 and 9 mg/g of wet weight (normal, less than or equal to 0.5 mg/g), correlated well (r = .93, P less than or equal to .0001) with the preoperative in vivo hepatic 1/T2 measurements. The CT attenuation did not correlate with liver iron concentration. Quantitative MR imaging is a readily available noninvasive method for the assessment of hepatic iron concentration in iron-overloaded patients, reducing the need for needle biopsies of the liver
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Monocyte transferrin-iron uptake in hereditary hemochromatosis
International Nuclear Information System (INIS)
Sizemore, D.J.; Bassett, M.L.
1984-01-01
Transferrin-iron uptake by peripheral blood monocytes was studied in vitro to test the hypothesis that the relative paucity of mononuclear phagocyte iron loading in hereditary hemochromatosis results from a defect in uptake of iron from transferrin. Monocytes from nine control subjects and 17 patients with hemochromatosis were cultured in the presence of 59Fe-labelled human transferrin. There was no difference in 59Fe uptake between monocytes from control subjects and monocytes from patients with hemochromatosis who had been treated by phlebotomy and who had normal body iron stores. However, 59Fe uptake by monocytes from iron-loaded patients with hemochromatosis was significantly reduced compared with either control subjects or treated hemochromatosis patients. It is likely that this was a secondary effect of iron loading since iron uptake by monocytes from treated hemochromatosis patients was normal. Assuming that monocytes in culture reflect mononuclear phagocyte iron metabolism in vivo, this study suggests that the relative paucity of mononuclear phagocyte iron loading in hemochromatosis is not related to an abnormality in transferrin-iron uptake by these cells
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Neiser, Susann; Rentsch, Daniel; Dippon, Urs; Kappler, Andreas; Weidler, Peter G; Göttlicher, Jörg; Steininger, Ralph; Wilhelm, Maria; Braitsch, Michaela; Funk, Felix; Philipp, Erik; Burckhardt, Susanna
2015-08-01
The advantage of the new generation IV iron preparations ferric carboxymaltose (FCM), ferumoxytol (FMX), and iron isomaltoside 1000 (IIM) is that they can be administered in relatively high doses in a short period of time. We investigated the physico-chemical properties of these preparations and compared them with those of the older preparations iron sucrose (IS), sodium ferric gluconate (SFG), and low molecular weight iron dextran (LMWID). Mössbauer spectroscopy, X-ray diffraction, and Fe K-edge X-ray absorption near edge structure spectroscopy indicated akaganeite structures (β-FeOOH) for the cores of FCM, IIM and IS, and a maghemite (γ-Fe2O3) structure for that of FMX. Nuclear magnetic resonance studies confirmed the structure of the carbohydrate of FMX as a reduced, carboxymethylated, low molecular weight dextran, and that of IIM as a reduced Dextran 1000. Polarography yielded significantly different fingerprints of the investigated compounds. Reductive degradation kinetics of FMX was faster than that of FCM and IIM, which is in contrast to the high stability of FMX towards acid degradation. The labile iron content, i.e. the amount of iron that is only weakly bound in the polynuclear iron core, was assessed by a qualitative test that confirmed decreasing labile iron contents in the order SFG ≈ IS > LMWID ≥ FMX ≈ IIM ≈ FCM. The presented data are a step forward in the characterization of these non-biological complex drugs, which is a prerequisite to understand their cellular uptake mechanisms and the relationship between the structure and physiological safety as well as efficacy of these complexes.
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Caetano-Silva, Maria Elisa; Barros Mariutti, Lilian Regina; Bragagnolo, Neura; Bertoldo-Pacheco, Maria Teresa; Netto, Flavia Maria
2018-02-28
Food fortification with iron may favor lipid oxidation in both food matrices and the human body. This study aimed at evaluating the effect of peptide-iron complexation on lipid oxidation catalyzed by iron, using oil-in-water (O/W) emulsions as a model system. The extent of lipid oxidation of emulsions containing iron salts (FeSO 4 or FeCl 2 ) or iron complexes (peptide-iron complexes or ferrous bisglycinate) was evaluated during 7 days, measured as primary (peroxide value) and secondary products (TBARS and volatile compounds). Both salts catalyzed lipid oxidation, leading to peroxide values 2.6- to 4.6-fold higher than the values found for the peptide-iron complexes. The addition of the peptide-iron complexes resulted in the formation of lower amounts of secondary volatiles of lipid oxidation (up to 78-fold) than those of iron salts, possibly due to the antioxidant activity of the peptides and their capacity to keep iron apart from the lipid phase, since the iron atom is coordinated and takes part in a stable structure. The peptide-iron complexes showed potential to reduce the undesirable sensory changes in food products and to decrease the side effects related to free iron and the lipid damage of cell membranes in the organism, due to the lower reactivity of iron in the complexed form.
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Protein Hydrolysates as Promoters of Non-Haem Iron Absorption
Li, Yanan; Jiang, Han; Huang, Guangrong
2017-01-01
Iron (Fe) is an essential micronutrient for human growth and health. Organic iron is an excellent iron supplement due to its bioavailability. Both amino acids and peptides improve iron bioavailability and absorption and are therefore valuable components of iron supplements. This review focuses on protein hydrolysates as potential promoters of iron absorption. The ability of protein hydrolysates to chelate iron is thought to be a key attribute for the promotion of iron absorption. Iron-chelatable protein hydrolysates are categorized by their absorption forms: amino acids, di- and tri-peptides and polypeptides. Their structural characteristics, including their size and amino acid sequence, as well as the presence of special amino acids, influence their iron chelation abilities and bioavailabilities. Protein hydrolysates promote iron absorption by keeping iron soluble, reducing ferric iron to ferrous iron, and promoting transport across cell membranes into the gut. We also discuss the use and relative merits of protein hydrolysates as iron supplements. PMID:28617327
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Protein Hydrolysates as Promoters of Non-Haem Iron Absorption
Directory of Open Access Journals (Sweden)
Yanan Li
2017-06-01
Full Text Available Iron (Fe is an essential micronutrient for human growth and health. Organic iron is an excellent iron supplement due to its bioavailability. Both amino acids and peptides improve iron bioavailability and absorption and are therefore valuable components of iron supplements. This review focuses on protein hydrolysates as potential promoters of iron absorption. The ability of protein hydrolysates to chelate iron is thought to be a key attribute for the promotion of iron absorption. Iron-chelatable protein hydrolysates are categorized by their absorption forms: amino acids, di- and tri-peptides and polypeptides. Their structural characteristics, including their size and amino acid sequence, as well as the presence of special amino acids, influence their iron chelation abilities and bioavailabilities. Protein hydrolysates promote iron absorption by keeping iron soluble, reducing ferric iron to ferrous iron, and promoting transport across cell membranes into the gut. We also discuss the use and relative merits of protein hydrolysates as iron supplements.
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Reduced activation ODS ferritic steel - recent development in high speed hot extrusion processing
Energy Technology Data Exchange (ETDEWEB)
Oksiuta, Zbigniew [Faculty of Mechanical Engineering, Bialystok Technical University (Poland); Lewandowska, Malgorzata; Kurzydlowski, Krzysztof [Faculty of Materials Science and Engineering, Warsaw University of Technology (Poland); Baluc, Nadine [Ecole Polytechnique Federale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas, Association Euratom-Confederation Suisse, Villigen PSI (Switzerland)
2010-05-15
The paper presents the microstructure and mechanical properties of an oxide dispersion strengthened (ODS), reduced activation, ferritic steel, namely the Fe-14Cr-2W-0.3Ti-0.3Y{sub 2}O{sub 3} alloy, which was fabricated by hot isostatic pressing followed by high speed hydrostatic extrusion (HSHE) and heat treatment HT at 1050 C. Transmission electron microscopy (TEM) observations revealed significant differences in the grain size and dislocation density between the as-HIPped and as-HSHE materials. It was also found that the microstructure of the steel is stable after HT. The HSHE process improves significantly the tensile and Charpy impact properties of the as-HIPped steel. The ultimate tensile strength at room temperature increases from 950 up to 1350 MPa, while the upper shelf energy increases from 3.0 up to 6.0 J. However, the ductile-to-brittle transition temperature (DBTT) remains relatively high (about 75 C).These results indicate that HSHE is a promising method for achieving grain refinement and thus improving the mechanical properties of ODS ferritic steels. (Abstract Copyright [2010], Wiley Periodicals, Inc.)
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International Nuclear Information System (INIS)
Yi, Danqing; Yu, Pengchao; Hu, Bin; Liu, Huiqun; Wang, Bin; Jiang, Yong
2013-01-01
Highlights: • Ni-coated TiC composite powders were prepared by electroless plating. • Iron-based composites reinforced by TiC particles was prepared by HIP. • Mechanical and wear properties were improved with the addition of Ni-coated TiC. • The nickel coating promotes the formation and growth of sintering neck. - Abstract: Ni-coated titanium carbide (TiC) composite powders were prepared by electroless plating (EP). Further, using hot isostatic pressing (HIP), iron matrix composites reinforced with 4 wt% Ni-coated TiC particulates with relative density close to 100% were prepared. The microstructure and phase composition of the Ni-coated powders and the composites were analyzed using X-ray diffraction, scanning electron microscopy, and energy dispersive X-ray spectroscopy. The results showed that the TiC particles were distributed uniformly in the matrix and were free of segregation or coarsening. Compared to the TiC particles without Ni coating, the reinforced iron-based composites containing the Ni-coated particles showed higher relative densities and better mechanical properties. The density, hardness, tensile strength, and elongation were enhanced to 99.98%, 243 HV, 565 MPa, and 11.7%, respectively in composites containing Ni-coated TiC particles from 99.70%, 210 HV, 514 MPa, and 10.3%, respectively in composites that were prepared using particles without Ni coating. In addition, the mass losses in the composites containing the Ni-coated particles were reduced by 32–75% in the abrasive wear test with various vertical loads. We propose that the nickel coatings on the particulates had a beneficial effect on the microstructure and properties of the reinforced iron-based composites is due to promotion of neck formation and growth between TiC and iron powders during sintering, which enhanced the density of the sintered compact and the bonding strength between the TiC particles and the iron matrix
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Influence of iron on plutonium absorption by the adult and neonatal rat
International Nuclear Information System (INIS)
Sullivan, M.F.; Ruemmler, P.S.; Buschbom, R.L.
1986-01-01
To determine how iron affects plutonium absorption, adult rats were gavaged with 238 Pu nitrate (pH 2) after they had been fed an iron-deficient diet or treated with iron supplements. Neonatal rats born to dams on an iron-deficient diet were also gavaged with 238 Pu. An iron-deficient diet resulted in enhanced 238 Pu absorption both in the adults and in neonates born to iron-deficient dams. Ferric iron increased 238 Pu absorption 12-fold in adult rats; injected iron-dextran reduced that increase; gavaged ferrous iron reduced 238 Pu absorption to one-third of the control value. Rat neonates absorbed 30 to 40 times as much 238 Pu as adults; absorption was lowered in groups that received iron supplements: Iron-dextran caused a 50% reduction; ferric iron, 95%; and ferrous iron, greater than 95%. The results demonstrate an effect of the oxidation state of iron on plutonium absorption in adult rats different from that observed in suckling rats. The results suggest that the high rate of 238 Pu absorption by neonatal animals is due not only to the permeability of their intestines but also to their high demand for iron
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Effect of reduced cobalt contents on hot isostatically pressed powder metallurgy U-700 alloys
Harf, F. H.
1982-01-01
The effect of reducing the cobalt content of prealloyed powders of UDIMET 700 (U-700) alloys to 12.7, 8.6, 4.3, and 0% was examined. The powders were hot isostatically pressed into billets, which were given heat treatments appropriate for turbine disks, namely partial solutioning at temperatures below the gamma prime solvus and four step aging treatments. Chemical analyses, metallographic examinations, and X-ray diffraction measurements were performed on the materials. Minor effects on gamma prime content and on room temperature and 650 C tensile properties were observed. Creep rupture lives at 650 C reached a maximum at the 8.4% concentration, while at 760 C a maximum in life was reached at the 4.3% cobalt level. Minimum creep rates increased with decreasing cobalt content at both test temperatures. Extended exposures at 760 and 815 C resulted in decreased tensile strengths and rupture lives for all alloys. Evidence of sigma phase formation was also found.
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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...
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Zhang, L; Ye, Y; Tu, H; Hildebrandt, M A; Zhao, L; Heymach, J V; Roth, J A; Wu, X
2017-05-01
Genetic variations in MicroRNA (miRNA) binding sites may alter structural accessibility of miRNA binding sites to modulate risk of cancer. This large-scale integrative multistage study was aimed to evaluate the interplay of genetic variations in miRNA binding sites of iron regulatory pathway, dietary iron intake and lung cancer (LC) risk. The interplay of genetic variant, dietary iron intake and LC risk was assessed in large-scale case-control study. Functional characterization of the validated SNP and analysis of target miRNAs were performed. We found that the miRNA binding site SNP rs1062980 in 3' UTR of Iron-Responsive Element Binding protein 2 gene (IREB2) was associated with a 14% reduced LC risk (P value = 4.9×10 - 9). Comparing to AA genotype, GG genotype was associated with a 27% reduced LC risk. This association was evident in males and ever-smokers but not in females and never-smokers. Higher level of dietary iron intake was significantly associated with 39% reduced LC risk (P value = 2.0×10 - 8). This association was only present in individuals with AG + AA genotypes with a 46% reduced risk (P value = 1.0×10 - 10), but not in GG genotype. The eQTL-analysis showed that rs1062980 significantly alters IREB2 expression level. Rs1062980 is predicted to alter a miR-29 binding site on IREB2 and indeed the expression of miR-29 is inversely correlated with IREB2 expression. Further, we found that higher circulating miR-29a level was significantly associated with 78% increased LC risk. The miRNA binding site SNP rs1062980 in iron regulatory pathway, which may alter the expression of IREB2 potentially through modulating the binding of miR-29a, together with dietary iron intake may modify risk of LC both individually and jointly. These discoveries reveal novel pathway for understanding lung cancer tumorigenesis and risk stratification. © The Author 2017. Published by Oxford University Press on behalf of the European Society for
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Luef, Birgit; Fakra, Sirine C; Csencsits, Roseann; Wrighton, Kelly C; Williams, Kenneth H; Wilkins, Michael J; Downing, Kenneth H; Long, Philip E; Comolli, Luis R; Banfield, Jillian F
2013-02-01
Iron-reducing bacteria (FeRB) play key roles in anaerobic metal and carbon cycling and carry out biogeochemical transformations that can be harnessed for environmental bioremediation. A subset of FeRB require direct contact with Fe(III)-bearing minerals for dissimilatory growth, yet these bacteria must move between mineral particles. Furthermore, they proliferate in planktonic consortia during biostimulation experiments. Thus, a key question is how such organisms can sustain growth under these conditions. Here we characterized planktonic microbial communities sampled from an aquifer in Rifle, Colorado, USA, close to the peak of iron reduction following in situ acetate amendment. Samples were cryo-plunged on site and subsequently examined using correlated two- and three-dimensional cryogenic transmission electron microscopy (cryo-TEM) and scanning transmission X-ray microscopy (STXM). The outer membranes of most cells were decorated with aggregates up to 150 nm in diameter composed of ∼3 nm wide amorphous, Fe-rich nanoparticles. Fluorescent in situ hybridization of lineage-specific probes applied to rRNA of cells subsequently imaged via cryo-TEM identified Geobacter spp., a well-studied group of FeRB. STXM results at the Fe L(2,3) absorption edges indicate that nanoparticle aggregates contain a variable mixture of Fe(II)-Fe(III), and are generally enriched in Fe(III). Geobacter bemidjiensis cultivated anaerobically in the laboratory on acetate and hydrous ferric oxyhydroxides also accumulated mixed-valence nanoparticle aggregates. In field-collected samples, FeRB with a wide variety of morphologies were associated with nano-aggregates, indicating that cell surface Fe(III) accumulation may be a general mechanism by which FeRB can grow while in planktonic suspension.
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Moehler, S.; Landsman, W. B.; Sweigart, A. V.; Grundahl, F.
2002-01-01
We present the results of spectroscopic analyses of hot horizontal branch (HB) stars in M13 and M3, which form a famous second parameter pair. From the spectra we derived - for the first time in M13 - atmospheric parameters (effective temperature and surface gravity) as well as abundances of helium, magnesium, and iron. Consistent with analyses of hot HB stars in other globular clusters we find evidence for helium depletion and iron enrichment in stars hotter than about 12,000 K in both M3 and M13. Accounting for the iron enrichment substantially improves the agreement with canonical evolutionary models, although the derived gravities and masses are still somewhat too low. This remaining discrepancy may be an indication that scaled-solar metal-rich model atmospheres do not adequately represent the highly non-solar abundance ratios found in blue HB stars with radiative levitation. We discuss the effects of an enhancement in the envelope helium abundance on the atmospheric parameters of the blue HB stars, as might be caused by deep mixing on the red giant branch or primordial pollution from an earlier generation of intermediate mass asymptotic giant branch stars.
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Low CO{sub 2} emission technologies for iron and steelmaking as well as titania slag production
Energy Technology Data Exchange (ETDEWEB)
Orth, A.; Anastasijevic, N.; Eichberger, H. [Outokumpu Technol GmbH, Oberursel (Germany)
2007-08-15
Outokumpu Technology has developed direct reduction technologies that allow in combination with smelting reduction processes or electric arc furnaces a substantial lowering of CO{sub 2} emissions. In this paper three examples are given: The Circofer process, already demonstrated in pilot plant scale, uses coal as reductant in a two stage CFB (circulating fluidized bed)/FB (fluidized bed) reactor configuration to obtain a highly metallized product suitable for charging into smelting processes. One possible application of Circofer is, in a single stage configuration, as prereduction unit in combination with HIsmelt a smelting reduction technology to produce hot metal using iron ore and coal fines. Using Circofer as prereduction step, the capacity of a given HIsmelt installation can be increased by the factor three to four compared to cold feed and CO, emission can be lowered to values about 20% below the standard of a modern blast furnace, as this combination of technologies requires no agglomeration plant or coke ovens. A second application of Circofer is the combination with an electric arc furnace (EAF) to produce steel directly from direct reduced iron (DRI). Charging hot DRI into an EAF decreases drastically electric power consumption and thus further lowers CO, emission. Applying Circosmelt, the combination of a single stage Circofer system with an electric reduction furnace for ilmenite processing, only half of the electric power consumption required today for titania slag production using cold, unreduced feed material is required. A common additional advantage of all Circofer based routes is that a 99% pure CO{sub 2} stream is removed for process reasons from the process gas and can be used for enhanced crude oil production or sequestration methods.
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Iron cycling at corroding carbon steel surfaces
Lee, Jason S.; McBeth, Joyce M.; Ray, Richard I.; Little, Brenda J.; Emerson, David
2013-01-01
Surfaces of carbon steel (CS) exposed to mixed cultures of iron-oxidizing bacteria (FeOB) and dissimilatory iron-reducing bacteria (FeRB) in seawater media under aerobic conditions were rougher than surfaces of CS exposed to pure cultures of either type of microorganism. The roughened surface, demonstrated by profilometry, is an indication of loss of metal from the surface. In the presence of CS, aerobically grown FeOB produced tight, twisted helical stalks encrusted with iron oxides. When CS was exposed anaerobically in the presence of FeRB, some surface oxides were removed. However, when the same FeOB and FeRB were grown together in an aerobic medium, FeOB stalks were less encrusted with iron oxides and appeared less tightly coiled. These observations suggest that iron oxides on the stalks were reduced and solubilized by the FeRB. Roughened surfaces of CS and denuded stalks were replicated with three culture combinations of different species of FeOB and FeRB under three experimental conditions. Measurements of electrochemical polarization resistance established different rates of corrosion of CS in aerobic and anaerobic media, but could not differentiate rate differences between sterile controls and inoculated exposures for a given bulk concentration of dissolved oxygen. Similarly, total iron in the electrolyte could not be used to differentiate treatments. The experiments demonstrate the potential for iron cycling (oxidation and reduction) on corroding CS in aerobic seawater media. PMID:24093730
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Energy Technology Data Exchange (ETDEWEB)
Ahmed, Wael Ahmed Abou Taleb Sayed
2011-01-13
This work presents the experimental results of the synthesis of unsupported and supported SiC iron oxide nanoparticles and their catalytic activity towards ethanol partial oxidation. For comparison, further unsupported iron oxide phases were investigated towards the ethanol partial oxidation. These {gamma}-Fe{sub 2}O{sub 3} and {alpha}/{gamma}-Fe{sub 2}O{sub 3} phase catalysts were prepared by the CVS method using Fe(CO){sub 5} as precursor, supplied by another author. The {alpha}-Fe{sub 2}O{sub 3} and SiC nanoparticles were prepared by the CVS method using a home made hot wall reactor technique at atmospheric pressure. Ferrocene and tetramethylsilane were used as precursor for the production process. Process parameters of precursor evaporation temperature, precursor concentration, gas mixture velocity and gas mixture dilution were investigated and optimised to produce particle sizes in a range of 10 nm. For Fe{sub 2}O{sub 3}/SiC catalyst series production, a new hot wall reactor setup was used. The particles were produced by simultaneous thermal decomposition of ferrocene and tetramethylsilane in one reactor from both sides. The production parameters of inlet tube distance inside the reactor, precursor evaporation temperature and carrier gas flow were investigated to produce a series of samples with different iron oxide content. The prepared catalysts composition, physical and chemical properties were characterized by XRD, EDX, SEM, BET surface area, FTIR, XPS and dynamic light scattering (DLS) techniques. The catalytic activity for the ethanol gas-phase oxidation was investigated in a temperature range from 260 C to 290 C. The product distributions obtained over all catalysts were analysed with mass spectrometry analysis tool. The activity of bulk Fe{sub 2}O{sub 3} and SiC nanoparticles was compared with prepared nano-iron oxide phase catalysts. The reaction parameters, such as reaction temperature and O{sub 2}/ethanol ratio were investigated. The catalysts
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Reelfs, Olivier; Eggleston, Ian M; Pourzand, Charareh
2010-03-01
In humans, prolonged sunlight exposure is associated with various pathological states. The continuing drive to develop improved skin protection involves not only approaches to reduce DNA damage by solar ultraviolet B (UVB) but also the development of methodologies to provide protection against ultraviolet A (UVA), the oxidising component of sunlight. Furthermore identification of specific cellular events following ultraviolet (UV) irradiation is likely to provide clues as to the mechanism of the development of resulting pathologies and therefore strategies for protection. Our discovery that UVA radiation, leads to an immediate measurable increase in 'labile' iron in human skin fibroblasts and keratinocytes provides a new insight into UVA-induced skin damage, since iron is a catalyst of biological oxidations. The main purpose of this overview is to bring together some of the new findings related to mechanisms underlying UVA-induced iron release and to discuss novel approaches based on the use of multiantioxidants and light-activated caged-iron chelators for efficient protection of skin cells against UVA-induced iron damage.
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Phase Transformation of Hot Dipped Aluminium during High Temperature Oxidation
International Nuclear Information System (INIS)
Zaifol Samsu; Muhammad Daud; Hishamuddin Husain; Mohd Saari Ripin; Rusni Rejab; Zaiton Selamat; Mohd Shariff Sattar
2014-01-01
Low alloy carbon steel was coated by hot-dipping into a molten aluminum bath. Isothermal oxidations were carried out at 750 degree Celsius in static air to study the oxidation behaviour of the hot-dipped aluminide steel. The phase transformation in the aluminide layer during diffusion at 750 degree Celsius in static air was analyzed by SEM-EDX and XRD. After hot-dip treatment, the coating layers consisted of three phases, where Al, thinner layer of FeAl 3 , and thicker layer of Fe 2 Al 5 were detected from external topcoat to the aluminide/ steel substrate. After oxidation, the Fe 2 Al 5 formed during the immersion process completely transformed to Fe 2 Al 5 , FeAl 2 , FeAl and Al-Fe(Al) phases because of the composition gradient and the chemical diffusion by oxidation. After oxidation, there are some voids were found at the coating/ substrate interface due to the rapid inter-diffusion of iron and aluminium during oxidation. The FeAl phase kept growing with increasing exposure time at 750 degree Celsius, while the Fe 2 Al 5 was consumed during oxidation. After 168 hrs oxidation, the Fe 2 Al 5 phase was going disappeared as the aluminum layer was consumed. (author)
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Directory of Open Access Journals (Sweden)
Svein Oskar Frigstad
2017-01-01
Full Text Available Background. Intravenous iron allows for efficient and well-tolerated treatment in iron deficiency and is routinely used in diseases of the gastrointestinal tract. Objective. The aims of this study were to determine the probability of relapse of iron deficiency over time and to investigate treatment routine, effectiveness, and safety of iron isomaltoside. Methods. A total of 282 patients treated with iron isomaltoside were observed for two treatments or a minimum of one year. Results. Out of 282 patients, 82 had Crohn’s disease and 67 had ulcerative colitis. Another 133 patients had chronic blood loss, malabsorption, or malignancy. Patients who received an iron isomaltoside dose above 1000 mg had a 65% lower probability of needing retreatment compared with those given 1000 mg. A clinically significant treatment response was shown, but in 71/191 (37% of patients, anaemia was not corrected. The mean dose given was 1100 mg, lower than the calculated total iron need of 1481 mg. Adverse drug reactions were reported in 4% of patients. Conclusion. Iron isomaltoside is effective with a good safety profile, and high doses reduce the need for retreatment over time. Several patients were anaemic after treatment, indicating that doses were inadequate for full iron correction. This trial is registered with NCT01900197.
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Directory of Open Access Journals (Sweden)
Nina Wrobel
2016-08-01
Full Text Available Introduction: Hereditary hemochromatosis features a dysregulated iron absorption leading to iron overload and organ damage. The regulation of total hemoglobin mass during depletion of iron deposits by therapeutic phlebotomy has not been studied. Case Presentation: The initial ferritin level of the 52-year-old male subject was 1,276 μg/l. Despite successful depletion of iron stores (ferritinmin: 53 μg/l through phlebotomies, total hemoglobin mass stabilized at the pretherapy level. However, regeneration of total hemoglobin mass was accelerated (up to 10.8 g/day. Conclusion: In this hemochromatosis patient, the total hemoglobin mass was not altered in the long term, but regeneration was accelerated, possibly due to elevated body iron content.
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Experimental comparison of gamma attenuations by glasses, lead, iron and concretes
International Nuclear Information System (INIS)
Charamathieu, Andre; Papot, Lucien
1964-08-01
The authors report the experimental determination, for lead glasses of density 3.3, 4.2, 5.2 and 6.2, of thicknesses equivalent to thicknesses given for lead, iron, ordinary concrete and barite concrete for Cobalt 60 and Caesium 137 radiations. Results are presented under the form of curves. Attenuation measurements made on this opportunity and those made on various hot cells have been compared with theoretical attenuation curves produced in another CEA document [fr
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Reduced iron associated with secondary nitrite maxima in the Arabian Sea
Digital Repository Service at National Institute of Oceanography (India)
Moffetta, J.W.; Goepferta, T.J.; Naqvi, S.W.A.
2007 Published by Elsevier Ltd. doi:10.1016/j.dsr.2007.04.004 ment of Biological Sciences, 3616 Trousedale Parkway, Los Angeles, CA 90079, USA. Dissolved iron (Fe) concentrations are generally very low in seawater, with primary production limited by Fe...
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Hsieh, Wen-Pin; Deschamps, Frédéric; Okuchi, Takuo; Lin, Jung-Fu
2018-04-17
Iron may critically influence the physical properties and thermochemical structures of Earth's lower mantle. Its effects on thermal conductivity, with possible consequences on heat transfer and mantle dynamics, however, remain largely unknown. We measured the lattice thermal conductivity of lower-mantle ferropericlase to 120 GPa using the ultrafast optical pump-probe technique in a diamond anvil cell. The thermal conductivity of ferropericlase with 56% iron significantly drops by a factor of 1.8 across the spin transition around 53 GPa, while that with 8-10% iron increases monotonically with pressure, causing an enhanced iron substitution effect in the low-spin state. Combined with bridgmanite data, modeling of our results provides a self-consistent radial profile of lower-mantle thermal conductivity, which is dominated by pressure, temperature, and iron effects, and shows a twofold increase from top to bottom of the lower mantle. Such increase in thermal conductivity may delay the cooling of the core, while its decrease with iron content may enhance the dynamics of large low shear-wave velocity provinces. Our findings further show that, if hot and strongly enriched in iron, the seismic ultralow velocity zones have exceptionally low conductivity, thus delaying their cooling.
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DEFF Research Database (Denmark)
Lund, Henriette Romme
Undersøgelse af, hvad der er hot - og hvad der burde være hot på læseområdet med 21 læsekyndige. Undersøgelsen er gennemført siden 2010. HOT-undersøgelsen er foretaget af Nationalt Videncenter for Læsning - Professionshøjskolerne i samarb. med Dansklærerforeningen......Undersøgelse af, hvad der er hot - og hvad der burde være hot på læseområdet med 21 læsekyndige. Undersøgelsen er gennemført siden 2010. HOT-undersøgelsen er foretaget af Nationalt Videncenter for Læsning - Professionshøjskolerne i samarb. med Dansklærerforeningen...
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The iron chelator deferasirox protects mice from mucormycosis through iron starvation
Ibrahim, Ashraf S.; Gebermariam, Teclegiorgis; Fu, Yue; Lin,, Lin; Husseiny, Mohamed I.; French, Samuel W.; Schwartz, Julie; Skory, Christopher D.; Edwards, John E.; Spellberg, Brad J.
2007-01-01
Mucormycosis causes mortality in at least 50% of cases despite current first-line therapies. Clinical and animal data indicate that the presence of elevated available serum iron predisposes the host to mucormycosis. Here we demonstrate that deferasirox, an iron chelator recently approved for use in humans by the US FDA, is a highly effective treatment for mucormycosis. Deferasirox effectively chelated iron from Rhizopus oryzae and demonstrated cidal activity in vitro against 28 of 29 clinical isolates of Mucorales at concentrations well below clinically achievable serum levels. When administered to diabetic ketoacidotic or neutropenic mice with mucormycosis, deferasirox significantly improved survival and decreased tissue fungal burden, with an efficacy similar to that of liposomal amphotericin B. Deferasirox treatment also enhanced the host inflammatory response to mucormycosis. Most importantly, deferasirox synergistically improved survival and reduced tissue fungal burden when combined with liposomal amphotericin B. These data support clinical investigation of adjunctive deferasirox therapy to improve the poor outcomes of mucormycosis with current therapy. As iron availability is integral to the pathogenesis of other infections (e.g., tuberculosis, malaria), broader investigation of deferasirox as an antiinfective treatment is warranted. PMID:17786247
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Localized sulfate-reducing zones in a coastal plain aquifer
Brown, C.J.; Coates, J.D.; Schoonen, M.A.A.
1999-01-01
High concentrations of dissolved iron in ground water of coastal plain or alluvial aquifers contribute to the biofouling of public supply wells for which treatment and remediation is costly. Many of these aquifers, however, contain zones in which microbial sulfate reduction and the associated precipitation of iron-sulfide minerals decreases iron mobility. The principal water-bearing aquifer (Magothy Aquifer of Cretaceous age) in Suffolk County, New York, contains localized sulfate-reducing zones in and near lignite deposits, which generally are associated with clay lenses. Microbial analyses of core samples amended with [14C]-acetate indicate that microbial sulfate reduction is the predominant terminal-electron-accepting process (TEAP) in poorly permeable, lignite-rich sediments at shallow depths and near the ground water divide. The sulfate-reducing zones are characterized by abundant lignite and iron-sulfide minerals, low concentrations of Fe(III) oxyhydroxides, and by proximity to clay lenses that contain pore water with relatively high concentrations of sulfate and dissolved organic carbon. The low permeability of these zones and, hence, the long residence time of ground water within them, permit the preservation and (or) allow the formation of iron-sulfide minerals, including pyrite and marcasite. Both sulfate-reducing bacteria (SRB) and iron-reducing bacteria (IRB) are present beneath and beyond the shallow sulfate-reducing zones. A unique Fe(III)-reducing organism, MD-612, was found in core sediments from a depth of 187 m near the southern shore of Long Island. The distribution of poorly permeable, lignite-rich, sulfate-reducing zones with decreased iron concentration is varied within the principal aquifer and accounts for the observed distribution of dissolved sulfate, iron, and iron sulfides in the aquifer. Locating such zones for the placement of production wells would be difficult, however, because these zones are of limited aerial extent.
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Directory of Open Access Journals (Sweden)
Yu-Chen eLing
2015-07-01
Full Text Available Coastal acid sulfate soils (CASS constitute a serious and global environmental problem. Oxidation of iron sulfide minerals exposed to air generates sulfuric acid with consequently negative impacts on coastal and estuarine ecosystems. Tidal inundation represents one current treatment strategy for CASS, with the aim of neutralizing acidity by triggering microbial iron- and sulfate-reduction and inducing the precipitation of iron-sulfides. Although well-known functional guilds of bacteria drive these processes, their distributions within CASS environments, as well as their relationships to tidal cycling and the availability of nutrients and electron acceptors, are poorly understood. These factors will determine the long-term efficacy of passive CASS remediation strategies. Here we studied microbial community structure and functional guild distribution in sediment cores obtained from ten depths ranging from 0-20 cm in three sites located in the supra-, inter- and sub-tidal segments, respectively, of a CASS-affected salt marsh (East Trinity, Cairns, Australia. Whole community 16S rRNA gene diversity within each site was assessed by 454 pyrotag sequencing and bioinformatic analyses in the context of local hydrological, geochemical and lithological factors. The results illustrate spatial overlap, or close association, of iron- and sulfate-reducing bacteria in an environment rich in organic matter and controlled by parameters such as acidity, redox potential, degree of water saturation, and mineralization. The observed spatial distribution implies the need for empirical understanding of the timing, relative to tidal cycling, of various terminal electron-accepting processes that control acid generation and biogeochemical iron and sulfur cycling.
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Daily oral iron supplementation during pregnancy
Peña-Rosas, Juan Pablo; De-Regil, Luz Maria; Dowswell, Therese; Viteri, Fernando E
2014-01-01
Background Iron and folic acid supplementation has been the preferred intervention to improve iron stores and prevent anaemia among pregnant women, and it may also improve other maternal and birth outcomes. Objectives To assess the effects of daily oral iron supplements for pregnant women, either alone or in conjunction with folic acid, or with other vitamins and minerals as a public health intervention. Search methods We searched the Cochrane Pregnancy and Childbirth Group’s Trials Register (2 July 2012). We also searched the WHO International Clinical Trials Registry Platform (ICTRP) (2 July 2012) and contacted relevant organisations for the identification of ongoing and unpublished studies. Selection criteria Randomised or quasi-randomised trials evaluating the effects of oral preventive supplementation with daily iron, iron + folic acid or iron + other vitamins and minerals during pregnancy. Data collection and analysis We assessed the methodological quality of trials using standard Cochrane criteria. Two review authors independently assessed trial eligibility, extracted data and conducted checks for accuracy. Main results We included 60 trials. Forty-three trials, involving more than 27,402 women, contributed data and compared the effects of daily oral supplements containing iron versus no iron or placebo. Overall, women taking iron supplements were less likely to have low birthweight newborns (below 2500 g) compared with controls (8.4% versus 10.2%, average risk ratio (RR) 0.81; 95% confidence interval (CI) 0.68 to 0.97, 11 trials, 8480 women) and mean birthweight was 30.81 g greater for those infants whose mothers received iron during pregnancy (average mean difference (MD) 30.81; 95% CI 5.94 to 55.68, 14 trials, 9385 women). Preventive iron supplementation reduced the risk of maternal anaemia at term by 70% (RR 0.30; 95% CI 0.19 to 0.46, 14 trials, 2199 women) and iron deficiency at term by 57% (RR 0.43; 95% CI 0.27 to 0.66, seven trials, 1256 women
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DEFF Research Database (Denmark)
Broholm, Mette; Arvin, Erik
2000-01-01
in the groundwater. The potential for biodegradation of the phenols in the sandstone aquifer at the site has been investigated in laboratory microcosms under aerobic (oxygen amended) and mixed nitrate and iron reducing (nitrate enriched and unamended) anaerobic conditions, at a range of concentrations (low: similar...... to 5 mg 1(-1): high: similar to 60 mg 1(-1), and very high: similar to 600 mg 1(-1)) and in the presence of other organic coal-tar compounds (mono- and polyaromatic hydrocarbons (BTEXs and PAHs) and heterocyclic compounds (NSOs)) and ammonia liquor. Sandstone cores and groundwater for the microcosms...
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Directory of Open Access Journals (Sweden)
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.
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Hydrometallurgical process for recovering iron sulfate and zinc sulfate from baghouse dust
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.
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Iron chelators ICL670 and 311 inhibit HIV-1 transcription
International Nuclear Information System (INIS)
Debebe, Zufan; Ammosova, Tatyana; Jerebtsova, Marina; Kurantsin-Mills, Joseph; Niu, Xiaomei; Charles, Sharroya; Richardson, Des R.; Ray, Patricio E.; Gordeuk, Victor R.; Nekhai, Sergei
2007-01-01
HIV-1 replication is induced by an excess of iron and iron chelation by desferrioxamine (DFO) inhibits viral replication by reducing proliferation of infected cells. Treatment of cells with DFO and 2-hydroxy-1-naphthylaldehyde isonicotinoyl hydrazone (311) inhibit expression of proteins that regulate cell-cycle progression, including cycle-dependent kinase 2 (CDK2). Our recent studies showed that CDK2 participates in HIV-1 transcription and viral replication suggesting that inhibition of CDK2 by iron chelators might also affect HIV-1 transcription. Here we evaluated the effect of a clinically approved orally effective iron chelator, 4-[3,5-bis-(hydroxyphenyl)-1,2,4-triazol-1-yl]-benzoic acid (ICL670) and 311 on HIV-1 transcription. Both ICL670 and 311 inhibited Tat-induced HIV-1 transcription in CEM-T cells, 293T and HeLa cells. Neither ICL670 nor 311 induced cytotoxicity at concentrations that inhibited HIV-1 transcription. The chelators decreased cellular activity of CDK2 and reduced HIV-1 Tat phosphorylation by CDK2. Neither ICL670A or 311 decreased CDK9 protein level but significantly reduced association of CDK9 with cyclin T1 and reduced phosphorylation of Ser-2 residues of RNA polymerase II C-terminal domain. In conclusion, our findings add to the evidence that iron chelators can inhibit HIV-1 transcription by deregulating CDK2 and CDK9. Further consideration should be given to the development of iron chelators for future anti-retroviral therapeutics
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Geographical distribution of hot flash frequencies: considering climatic influences.
Sievert, Lynnette Leidy; Flanagan, Erin K
2005-10-01
Laboratory studies suggest that hot flashes are triggered by small elevations in core body temperature acting within a reduced thermoneutral zone, i.e., the temperature range in which a woman neither shivers nor sweats. In the present study, it was hypothesized that women in different populations develop climate-specific thermoneutral zones, and ultimately, population-specific frequencies of hot flashes at menopause. Correlations were predicted between hot flash frequencies and latitude, elevation, and annual temperatures. Data on hot flash frequencies were drawn from 54 studies. Pearson correlation analyses and simple linear regressions were applied, first using all studies, and second using a subset of studies that included participants only to age 60 (n = 36). Regressions were repeated with all studies, controlling for method of hot flash assessment. When analyses were restricted to studies that included women up to age 60, average temperature of the coldest month was a significant predictor of hot flash frequency (P hottest and coldest temperatures was also a significant predictor (P coldest month, difference between hottest and coldest temperatures, and mean annual temperature were significant predictors of hot flash frequency. Women reported fewer hot flashes in warmer temperatures, and more hot flashes with increasing seasonality. These results suggest that acclimatization to coldest temperatures or sensitivity to seasonality may explain part of the population variation in hot flash frequency.
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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).
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Reduction experiment of iron scale by adding waste plastics.
Zhang, Chongmin; Chen, Shuwen; Miao, Xincheng; Yuan, Hao
2009-01-01
The special features of waste plastics in China are huge in total amount, various in type and dispersive in deposition. Therefore, it is necessary to try some new ways that are fit to Chinese situation for disposing waste plastics as metallurgical raw materials more effectively and flexibly. Owing to its high ferrous content and less impurity, the iron scale became ideal raw material to produce pure iron powder. One of the methods to produce pure iron powder is Hoganas Method, by which, after one or multistage of reduction steps, the iron scale can be reduced pure iron powder. However, combining utilization of waste plastics and iron powder production, a series of reduction experiments were arranged and investigated, which is hoped to take use of both thermal and chemical energy contained in waste plastics as well as to improve the reducing condition of iron scale, and hence to develop a new metallurgical way of disposing waste plastics. The results show that under these experimental conditions, the thermal-decomposition of water plastics can conduce to an increase of porosity in the reduction systems. Moreover, better thermodynamics and kinetics conditions for the reduction of scale can be reached. As a result, the reduction rate is increased.
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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.
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Multi-Copper Oxidases and Human Iron Metabolism
Vashchenko, Ganna; MacGillivray, Ross T. A.
2013-01-01
Multi-copper oxidases (MCOs) are a small group of enzymes that oxidize their substrate with the concomitant reduction of dioxygen to two water molecules. Generally, multi-copper oxidases are promiscuous with regards to their reducing substrates and are capable of performing various functions in different species. To date, three multi-copper oxidases have been detected in humans—ceruloplasmin, hephaestin and zyklopen. Each of these enzymes has a high specificity towards iron with the resulting ferroxidase activity being associated with ferroportin, the only known iron exporter protein in humans. Ferroportin exports iron as Fe2+, but transferrin, the major iron transporter protein of blood, can bind only Fe3+ effectively. Iron oxidation in enterocytes is mediated mainly by hephaestin thus allowing dietary iron to enter the bloodstream. Zyklopen is involved in iron efflux from placental trophoblasts during iron transfer from mother to fetus. Release of iron from the liver relies on ferroportin and the ferroxidase activity of ceruloplasmin which is found in blood in a soluble form. Ceruloplasmin, hephaestin and zyklopen show distinctive expression patterns and have unique mechanisms for regulating their expression. These features of human multi-copper ferroxidases can serve as a basis for the precise control of iron efflux in different tissues. In this manuscript, we review the biochemical and biological properties of the three human MCOs and discuss their potential roles in human iron homeostasis. PMID:23807651
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Zegeye, A.; Yahaya, S.; Fialips, C. I.; White, M.; Manning, D. A.; Gray, N.
2008-12-01
Biogeochemical evidence exists to support the potential importance of crystalline or amorphous Fe minerals as electron acceptor for Fe reducing bacteria in soils and subsurface sediments. This microbial metabolic activity can be exploited as alternative method in different industrial applications. For instance, the removal of ferric iron impurities from minerals for the glass and paper industries currently rely on physical and chemical treatments having substantial economical and environmental disadvantages. The ability to remove iron by other means, such as bacterial iron reduction, may reduce costs, allow lower grade material to be mined, and improve the efficiency of mineral processing. Kaolin clay and silica sand are used in a wide range of industrial applications, particularly in paper, ceramics and glass manufacturing. Depending on the geological conditions of deposition, they are often associated with iron (hydr)oxides that are either adsorbed to the mineral surfaces or admixed as separate iron bearing minerals. In this study, we have examined the Fe(III) removal efficiency from kaolin and silica sand by a series of iron- reducing bacteria from the Shewanella species (S. alga BrY, S. oneidensis MR-1, S. putrefaciens CN32 and S. putrefaciens ATCC 8071) in the presence of anthraquinone 2,6 disulfonate (AQDS). We have also investigated the effectiveness of a natural organic matter, extracted with the silica sand, as a substitute to AQDS for enhancing Fe(III) reduction kinetics. The microbial reduction of Fe(III) was achieved using batch cultures under non-growth conditions. The rate and the extent of Fe(III) reduction was monitored as a function of the initial Fe(III) content, Shewanella species and temperature. The bacterially- treated minerals were analyzed by transmission electron microscopy (TEM) and X-ray diffraction (XRD) to observe any textural and mineralogical transformation. The whiteness and ISO brightness of the kaolin was also measured by
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Reduction of iron-bearing lunar minerals for the production of oxygen
Massieon, Charles; Cutler, Andrew; Shadman, Farhang
1992-01-01
The kinetics and mechanism of the reduction of simulants of the iron-bearing lunar minerals olivine ((Fe,Mg)2SiO4), pyroxene ((Fe,Mg,Ca)SiO3), and ilmenite (FeTiO3) are investigated, extending previous work with ilmenite. Fayalite is reduced by H2 at 1070 K to 1480 K. A layer of mixed silica glass and iron forms around an unreacted core. Reaction kinetics are influenced by permeation of hydrogen through this layer and a reaction step involving dissociated hydrogen. Reaction mechanisms are independent of Mg content. Augite, hypersthene, and hedenbergite are reduced in H2 at the same temperatures. The products are iron metal and lower iron silicates mixed throughout the mineral. Activation energy rises with calcium content. Ilmenite and fayalite are reduced with carbon deposited on partially reduced minerals via the CO disproportionation reaction. Reduction with carbon is rapid, showing the carbothermal reduction of lunar minerals is possible.
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Brito, Alex; Olivares, Manuel; Pizarro, Tito; Rodríguez, Lorena; Hertrampf, Eva
2013-12-01
Iron deficiency is the most prevalent nutritional deficiency in the world, primarily affecting infants, young children, and women of childbearing age. To evaluate the impact of the National Complementary Feeding Program (NCFP) on anemia and iron status in Chilean children aged 11 to 18 months. Two studies were performed. The first study was performed at one public outpatient health center in Santiago, using data collected in 1999 (n = 128) and 2000 (n = 125), before and after the national introduction of iron-fortified milk. Subsequently, a study of a representative sample (n = 320) from the two most populated areas of the country was performed in 2009. One year after fortification, the prevalence of anemia was 9%; significantly lower (p < .001) than the 27% prevalence observed 1 year before. Ten years after fortification, 14% of children were anemic and 77% of children with anemia (12% of all children) suffered from iron-deficiency anemia. In 2009, 11% of children consuming iron-fortified milk delivered by the NCFP (73%) were anemic, significantly lower (p = .028) than the 21% prevalence of anemia observed in children without consumption. Consumption of iron-fortified milk was positively associated with hemoglobin concentration (r = 0.28, p = .022) and was associated with a lower prevalence of anemia after adjusting for confounding factors (odds ratio, 0.50; 95% CI, 0.26 to 0.96). In Chile, the NCFP has had an impact on the reduction of anemia and improved the iron status of children aged 11 to 18 months. Increasing the consumption of this iron-fortified milk could enhance the impact of the NCFP.
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Simulation of a Sponge Iron Production Process
Directory of Open Access Journals (Sweden)
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.
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Zhang, Lili; Yu, Xinxin; Hu, Hongrui; Li, Yang; Wu, Mingzai; Wang, Zhongzhu; Li, Guang; Sun, Zhaoqi; Chen, Changle
2015-03-19
Iron oxides/reduced graphene oxide composites were synthesized by facile thermochemical reactions of graphite oxide and FeSO4 · 7H2O. By adjusting reaction temperature, α-Fe2O3/reduced graphene oxide and Fe3O4/reduced graphene oxide composites can be obtained conveniently. Graphene oxide and reduced graphene oxide sheets were demonstrated to regulate the phase transition from α-Fe2O3 to Fe3O4 via γ-Fe2O3, which was reported for the first time. The hydroxyl groups attached on the graphene oxide sheets and H2 gas generated during the annealing of graphene oxide are believed to play an important role during these phase transformations. These samples showed good electromagnetic wave absorption performance due to their electromagnetic complementary effect. These samples possess much better electromagnetic wave absorption properties than the mixture of separately prepared Fe3O4 with rGO, suggesting the crucial role of synthetic method in determining the product properties. Also, these samples perform much better than commercial absorbers. Most importantly, the great stability of these composites is highly advantageous for applications as electromagnetic wave absorption materials at high temperatures.
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Xie, Ling; Zheng, Wei; Xin, Na; Xie, Jing-Wei; Wang, Tao; Wang, Zhan-You
2012-08-01
Dysregulation of iron homeostasis is involved in the pathological process of Alzheimer's disease (AD). We have recently reported that divalent metal transporter 1 (DMT1) is upregulated in an AD transgenic mouse brain, and that silencing of DMT1, which reduces cellular iron influx, results in inhibition of amyloidogenesis in vitro, suggesting a potential target of DMT1 for AD therapy. In the present study, we tested the hypothesis that inhibition of DMT1 with ebselen, a DMT1 transport inhibitor, could affect tau phosphorylation. Human neuroblastoma SH-SY5Y cells were pre-treated with ebselen and then treated with ferrous sulfate (dissolved in ascorbic acid), and the effects of ebselen on tau phosphorylation and the relative signaling pathways were examined. Our results showed that ebselen decreased iron influx, reduced iron-induced ROS production, inhibited the activities of cyclin-dependent kinase 5 and glycogen synthase kinase 3β, and ultimately attenuated the levels of tau phosphorylation at the sites of Thr205, Ser396 and Thr231. The present study indicates that the neuroprotective effect of ebselen on AD is not only related to its antioxidant activity as reported previously, but is also associated with a reduction in tau phosphorylation by inhibition of DMT1. Copyright © 2012 Elsevier Ltd. All rights reserved.
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Further fields of application for prestressed cast iron pressure vessels (PCIV)
International Nuclear Information System (INIS)
Guelicher, L.; Schilling, F.E.
1977-01-01
The redundancy of the prestressing system of prestressed structures as well as the clear separation of sealing and load-carrying functions of prestressed cast iron pressure vessels offer substantial advantages over conventional welded steel pressure vessels. Because of the temperature resistance of cast iron up to 400 0 C it is possible to build prestressed pressure vessels commercially as hot-working structures. The compressive strength of cast iron, which is 25 times as high as that of concrete allows for a very compact design of the PCIV. Further specific properties of the PCIV like pre-fabrication of the vessel in the production plant - made possible by a structure assembled from segments - short assembly periods at the construction site etc., may open more fields of application. - PCIV as pressurized storage tanks for the emergency shut down system in nuclear power stations. - PCIV as high pressure vessel for the chemical industry. - PCIV as energy storage. - PCIV for light water reactors. - PCIV as burst protection. It is concluded that the application of prestressed cast iron promises to be successful where either structures with large volumes and high pressures and/or temperatures are required or where aspects of safety allow for efficient use of prestressed structures. (Auth.)
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BC SEA Solar Hot Water Acceleration project
Energy Technology Data Exchange (ETDEWEB)
Harris, N.C. [BC Sustainable Energy Association, Victoria, BC (Canada)
2005-07-01
Although solar hot water heating is an environmentally responsible technology that reduces fossil fuel consumption and helps mitigate global climate change, there are many barriers to its widespread use. Each year, domestic water heating contributes nearly 6 million tonnes of carbon dioxide towards Canada's greenhouse gas emissions. The installation of solar water heaters can eliminate up to 2 tonnes of carbon dioxide emissions per household. The BC SEA Solar Hot Water Acceleration project was launched in an effort to demonstrate that the technology has the potential to be widely used in homes and businesses across British Columbia. One of the main barriers to the widespread use of solar hot water heating is the initial cost of the system. Lack of public awareness and understanding of the technology are other barriers. However, other jurisdictions around the world have demonstrated that the use of renewables are the product of conscious policy decisions, including low-cost financing and other subsidies that have created demand for these technologies. To this end, the BC SEA Solar Hot Water Acceleration project will test the potential for the rapid acceleration of solar water heating in pilot communities where barriers are removed. The objective of the project is to install 100 solar water systems in homes and 25 in businesses and institutions in communities in British Columbia by July 2007. The project will explore the financial barriers to the installation of solar hot water systems and produce an action plan to reduce these barriers. In addition to leading by example, the project will help the solar energy marketplace, mitigate climate change and improve energy efficiency.
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Direct Biohydrometallurgical Extraction of Iron from Ore
Energy Technology Data Exchange (ETDEWEB)
T.C. Eisele
2005-10-01
A completely novel approach to iron extraction was investigated, based on reductive leaching of iron by anaerobic bacteria. Microorganisms were collected from an anaerobic bog where natural seepage of dissolved iron was observed. This mixed culture was used to reduce insoluble iron in a magnetite ore to the soluble ferrous (Fe{sup +2}) state. While dissolution rates were slow, concentrations of dissolved iron as high as 3487 mg/l could be reached if sufficient time was allowed. A factorial study of the effects of trace nutrients and different forms of organic matter indicated that the best dissolution rates and highest dissolved iron concentrations were achieved using soluble carbohydrate (sucrose) as the bacterial food source, and that nutrients other than nitrogen, phosphorus, potassium, sodium, and acetate were not necessary. A key factor in reaching high levels of dissolved iron was maintaining a high level of carbon dioxide in solution, since the solubility of iron carbonates increases markedly as the quantity of dissolved carbon dioxide increases. Once the iron is dissolved, it has been demonstrated that the ferrous iron can then be electroplated from solution, provided that the concentration of iron is sufficiently high and the hydrogen ion concentration is sufficiently low. However, if the leaching solution is electrolyzed directly, organic matter precipitates at the cathode along with the metallic iron. To prevent this problem, the ferrous iron should be separated from the bulk solution in a more concentrated, purified form. One route to accomplishing this is to take advantage of the change in solubility of ferrous iron as a function of carbon dioxide concentration. By cycling the concentration of carbon dioxide in solution, it is possible to produce an iron-rich concentrate that should be suitable for electrolysis. This represents the first viable hydrometallurgical method for leaching iron directly from ore and producing metallic iron.
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Hot flashes Overview Hot flashes are sudden feelings of warmth, which are usually most intense over the face, neck and chest. Your skin might redden, as if you're blushing. Hot flashes can also cause sweating, and if you ...
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Attenuation of iron-binding proteins in ARPE-19 cells reduces their resistance to oxidative stress.
Karlsson, Markus; Kurz, Tino
2016-09-01
Oxidative stress-related damage to retinal pigment epithelial (RPE) cells is an important feature in the development of age-related macular degeneration. Iron-catalysed intralysosomal production of hydroxyl radicals is considered a major pathogenic factor, leading to lipofuscin formation with ensuing depressed cellular autophagic capacity, lysosomal membrane permeabilization and apoptosis. Previously, we have shown that cultured immortalized human RPE (ARPE-19) cells are extremely resistant to exposure to bolus doses of hydrogen peroxide and contain considerable amounts of the iron-binding proteins metallothionein (MT), heat-shock protein 70 (HSP70) and ferritin (FT). According to previous findings, autophagy of these proteins depresses lysosomal redox-active iron. The aim of this study was to investigate whether up- or downregulation of these proteins would affect the resistance of ARPE-19 cells to oxidative stress. The sensitivity of ARPE-19 cells to H2 O2 exposure was tested following upregulation of MT, HSP70 and/or FT by pretreatment with ZnSO4 , heat shock or FeCl3 , as well as siRNA-mediated downregulation of the same proteins. Upregulation of MT, HSP70 and FT did not improve survival following exposure to H2 O2 . This was interpreted as existence of an already maximal protection. Combined siRNA-mediated attenuation of both FT chains (H and L), or simultaneous downregulation of all three proteins, made the cells significantly more susceptible to oxidative stress confirming the importance of iron-binding proteins. The findings support our hypothesis that the oxidative stress resistance exhibited by RPE cells may be explained by a high autophagic influx of iron-binding proteins that would keep levels of redox-active lysosomal iron low. © 2016 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.
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International Nuclear Information System (INIS)
Bergman, B.; Forberg, S.
1984-01-01
Rutile was selected for some practical studies of processing and properties of ceramic containers. Hot isostatic pressing at 1280 0 C has resulted in reaction zones between the TiO 2 powder and the steel canning. The phases ilmenite, pseudobrookite, rutile, and iron have been identified by x-ray diffraction and by microprobe analysis. The microstructures have been interpreted by classical metallographic methods, and some microstructures obtained by hot pressing and rapid cooling have also been examined for purposes of comparison. Some implications of the microstructures have been discussed in terms of microcracking and slow crack growth. 13 refs., 7 figs
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Directory of Open Access Journals (Sweden)
Kathryn L. Beck
2014-01-01
Full Text Available This study investigated dietary patterns and nondietary determinants of suboptimal iron status (serum ferritin < 20 μg/L in 375 premenopausal women. Using multiple logistic regression analysis, determinants were blood donation in the past year [OR: 6.00 (95% CI: 2.81, 12.82; P<0.001], being Asian [OR: 4.84 (95% CI: 2.29, 10.20; P<0.001], previous iron deficiency [OR: 2.19 (95% CI: 1.16, 4.13; P=0.016], a “milk and yoghurt” dietary pattern [one SD higher score, OR: 1.44 (95% CI: 1.08, 1.93; P=0.012], and longer duration of menstruation [days, OR: 1.38 (95% CI: 1.12, 1.68; P=0.002]. A one SD change in the factor score above the mean for a “meat and vegetable” dietary pattern reduced the odds of suboptimal iron status by 79.0% [OR: 0.21 (95% CI: 0.08, 0.50; P=0.001] in women with children. Blood donation, Asian ethnicity, and previous iron deficiency were the strongest predictors, substantially increasing the odds of suboptimal iron status. Following a “milk and yoghurt” dietary pattern and a longer duration of menstruation moderately increased the odds of suboptimal iron status, while a “meat and vegetable” dietary pattern reduced the odds of suboptimal iron status in women with children.
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Noise pollution in iron and steel industry
International Nuclear Information System (INIS)
Bisio, G.; Piromalli, W.; Acerbo, P.
1999-01-01
Iron and steel industry is characterized by high energy consumption and thus present remarkable problems from the point of view of noise pollution. The aims of this paper is to examine characteristic and acoustical emissions and immisions of some fundamentals iron and steel plants with several remarks on the possible measures to reduce noise pollution. For a large integrate iron and steel system, some surveys are shown with all devices running and, in addition, comparisons are made with other surveys when the main devices were out of service owing to great maintenance works [it
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Hart, F. H.
1984-01-01
Because almost the entire U.S. consumption of cobalt depends on imports, this metal has been designated "strategic'. The role and effectiveness of cobalt is being evaluated in commercial nickel-base superalloys. Udiment 700 type alloys in which the cobalt content was reduced from the normal 17% down to 12.7%, 8.5%, 4.3%, and 0% were prepared by standard powder metallurgy techniques and hot isostatically pressed into billets. Mechanical testing and microstructural investigations were performed. The mechanical properties of alloys with reduced cobalt contents which were heat-treated identically were equal or better than those of the standard alloy, except that creep rates tended to increase as cobalt was reduced. The effects of long time exposures at 760 C on mechanical properties and at 760 C and 845 C on microstructures were determined. Decreased tensile properties and shorter rupture lives with increased creep rates were observed in alloy modifications. The exposures caused gamma prime particle coarsening and formation of sigma phase in the alloys with higher cobalt contents. Exposure at 845 C also reduced the amount of MC carbides.
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Concentration of 99Tc in seawater by coprecipitation with iron hydroxide
International Nuclear Information System (INIS)
Momoshima, Noriyuki; Eto, Ichiro; Muhammad Sayad; Takashima, Yoshimasa
1991-01-01
A method for accumulation of 99 Tc in seawater has been developed. Technetium tracer in +VII oxidation state was added to the seawater together with reducing agent, potassium pyrosulfite, and coprecipitation agent, ferric chloride. After reduction of Tc(VII) at pH 4, Tc(IV) was coprecipitated as iron hydroxide by addition of sodium hydroxide to pH 9. The reduction and coprecipitation was quantitative and overall recovery of Tc was more than 98%. The green color of iron precipitate formed at pH 9 suggested that Tc(VII) as well as ferric ion was reduced under this condition. Adsorption of Tc(IV), however, was poor for iron hydroxide which was prepared in advance indicating active surface of freshly precipitated iron hydroxide is necessary for quantitative recovery of Tc(IV). A repeating coprecipitation technique was examined for enrichment of Tc in seawater that the same iron was used repeatedly as coprecipitater. After separation of iron hydroxide with Tc(IV) from supernatant, the precipitate was dissolved by addition of acid and then new seawater which contained reducing agent and Tc(VII) was added. Reduction and coprecipitation was again carried out. Good recovery was attained for 7 repeats. The proposed repeating coprecipitation technique was applicable to a large amount of seawater without increasing the amount of iron hydroxide which is subjected to radiochemical analysis. (author)
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Lipocalin 2 deficiency dysregulates iron homeostasis and exacerbates endotoxin-induced sepsis
DEFF Research Database (Denmark)
Srinivasan, Gayathri; Aitken, Jesse D; Zhang, Benyue
2012-01-01
Various states of inflammation, including sepsis, are associated with hypoferremia, which limits iron availability to pathogens and reduces iron-mediated oxidative stress. Lipocalin 2 (Lcn2; siderocalin, 24p3) plays a central role in iron transport. Accordingly, Lcn2-deficient (Lcn2KO) mice exhib...
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Evaluation of the daily iron intake by non-breastfed Egyptian infants ...
African Journals Online (AJOL)
Iron deficiency is frequently associated with anaemia. The prevalence of anaemia among Egyptian infants and young children is 25%. Fortification of infant and followup milk-based formulae remains a valuable method for delivering iron to reduce the incidence of iron deficiency anaemia. Percentage of Egyptian ...
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International Nuclear Information System (INIS)
Gupta, R.C.; Morgan, G.H.
1989-01-01
The nominal-design SSC (Superconducting Super Collider) dipole encloses the coil in an iron yoke having a circular aperture. The radial gap between the coil and the iron is about 15 mm to provide space for a strong annular collar around the coil, and also to reduce the effects of iron saturation on central field harmonics. The 15 mm gap also reduces the desirable dipole field contributed by the iron. The present paper gives a coil and aperture configuration in which the gap is reduced to 5 mm at the midplane, in which the aperture is shaped to reduce the unwanted effects of iron saturation. The transfer function is increased about 5% at 6.6 Tesla and the unwanted harmonics are within SSC tolerances at all field levels. These designs would require that the yoke and containment vessel absorb the stresses due to assembly and magnetic forces. A short magnet is being built with a close-in shaped iron aperture and existing coil geometry to assess the benefits of this concept. 7 refs., 3 figs., 6 tabs
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Iron abundance in the hot DA white dwarfs Feige 24 and G191 B2B
Vennes, Stephane; Chayer, Pierre; Thorstensen, John R.; Bowyer, Stuart; Shipman, Harry L.
1992-01-01
Attention is given to model calculations of the far- and extreme-UV line spectra of highly ionized Fe species (Fe IV, Fe V, and Fe VI) for hot high-gravity H-rich stars. A spectral analysis of 31 hr of exposure of the DA white dwarf Feige 24 with IUE in the echelle mode reveals the presence of Fe with an abundance relative to H by number of (5-10) x 10 exp -6 with an uncertainty dominated by the determination of stellar parameters. An analysis of IUE data from the white dwarf G191 B2B results in a similar Fe abundance if this star shares similar atmospheric parameters (Teff, g) with Feige 24. Fe is thus the second most abundant photospheric element in hot DA white dwarfs.
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A Test of Pulsation Theory in Hot B Subdwarfs (bis)
Fontaine, G.
There are currently 33 hot B subdwarf (sdB) stars which are known to exhibit low-amplitude (a few to tens of mmag), short-period (100-500 s), multiperiodic luminosity variations caused by acoustic mode instabilities. These pulsations are thought to be driven by an opacity bump linked to the presence of a local enhancement of the iron and other iron-peak elements) abundance in the envelopes of sdB stars. Such an enhancement results quite naturally from the diffusive equilibrium between gravitational settling and radiative support in the stellar envelope. Nevertheless, surveys for pulsating sdB stars show that variable and nonvariable objects with similar effective temperatures and gravities coexist in the log g-Teff diagram. This puzzling result suggests that an additional parameter, perhaps a weak stellar wind, might affect the extent of the iron reservoir and thus the ability of the latter to drive pulsations in sdB stars. Fortunately, it is expected that such a wind might also leave its mark on the photospheric heavy element abundance patterns. The intended FUSE observations will 1) permit a direct comparison of the heavy element abundance patterns in variable and nonvariable stars of similar atmospheric parameters, 2) provide a consistency check with our wind models, and 3) provide a test of the currently-favored explanation for the driving of the observed pulsations.
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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.
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The evolution of meteorites and planets from a hot nebula
Directory of Open Access Journals (Sweden)
Donald H. Tarling
2015-06-01
Full Text Available Meteorites have a hot origin as planetary materials derive from a supernova, similar to SN1987A, and were acquired by a nearby nova, the Sun. The supernova plasmas became zoned around the nova, mainly by their electromagnetic properties. Carbon and carbide dusts condensed first, followed, within the Inner Planetary Zone, by Ca–Mg–Al oxides and then by iron and nickel metal droplets. In the inner Asteroid Belt, the metals aggregated into clumps as they solidified but over a much longer time in the Inner Zone. ‘Soft’ collisions formed larger (<∼20 km objects in the Asteroid Belt; in the Inner Zone these aggregated forming proto-planetary cores during inwards orbital migration. In the Asteroid Belt, glassy olivines condensed, followed more open lattice minerals growing grew primarily by diffusion. Brittle silicate crystals were comminuted and only aggregated into the carbonaceous meteorites when water–ices formed. The inner planets differentiated by at least 4.4 Ga. Jupiter and the outer planets grew on asteroidal bodies thrown out into freezing water vapours and only formed by 4.1 Ga, resulting in the Late Heavy Bombardment, initially by meteoritic materials and later supplemented by ices from, and beyond, the Asteroid Belt. Critical factors are the properties of very high temperature supernova plasmas, the duration of the molten iron phase in the inner zone. Evidence usually quoted for a cold origin derives from late stage processes in hot meteorite evolution. While highly speculative, it is shown that meteorites and planets can be formed by known processes as supernova plasmas cool.
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Genetics Home Reference: iron-refractory iron deficiency anemia
... 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 ...
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The low-aluminium cast iron of reduced silicon content treated with cerium mischmetal
Directory of Open Access Journals (Sweden)
M. S. Soiński
2008-07-01
Full Text Available The work presents the effect of cerium mischmetal used in quantities of 0.1 and 0.2 wt-% and ferrosilicon used in quantities from 0.5% to 1.5% on the alloy matrix and the shape of graphite precipitates in the low-aluminium cast iron from seven heats, basing on the examination of its structure. The hypereutectic cast iron of the relatively high carbon content (4.0÷4.2% at the prior-to-treatment silicon and manganese content equal to ca. 0.6% and ca. 0.04%, respectively, has been examined.It has been found that the performed treatment leads to the change in the alloy matrix from the nearly almost pearlitic to the ferritic-pearlitic one accompanied by changes in the shape of graphite precipitates. Due to applying both of the mentioned substances in the above stated amounts the graphite precipitates in cast iron have taken the shape of nodular and vermicular ones, and no presence of flake graphite has been revealed. A quantitative analysis of the performed treatment i.e. determining the fractions of graphite precipitates of different shapes has been possible by means of a computer image analyser.
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Association between iron deficiency anemia and blood level in egyptian children
International Nuclear Information System (INIS)
Nassar, E.M.; Moawad, A.T.; Abd Alla, A.M.
2003-01-01
The relationship between iron deficiency and blood lead levels was investigated in a cross-sectional study of 200 children of both sexes, aged 6-12 years with mean of 7.8 +- 2.6 years. They were randomly selected from governmental primary school located near a highly contaminated industrial area. Blood samples were collected for measuring blood lead levels, serum iron serum ferritin, hemoglobin, mean corpuscular volume (MCV) and total iron binding capacity (TIBC) and other hematological indices. According to iron status, children were classified into non-anemic healthy controls(n=37),iron depleted children(n=58)and children with iron deficiency anemia (n=105).Iron deficiency is defined when MCV 10 / dl were significantly lower than those for children with blood lead levels < 10 /dl. Comparison of blood lead concentrations between boys and girls revealed highly significant increase in blood lead level in boys than girls. A strong negative correlation was detected between blood lead levels and serum iron in all subjects. However, such correlation vanished between blood lead concentration and serum ferritin,so, it could be concluded from the present study that the blood lead levels were changed according to changes in iron status. Improving iron status, along with reducing exposure to environmental contamination with lead, may help in reducing blood lead levels among most children especially those living in contaminated environment
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Buisson, Christophe; Daou, Nadine; Kallassy, Mireille; Lereclus, Didier; Arosio, Paolo; Bou-Abdallah, Fadi; Nielsen Le Roux, Christina
2014-01-01
In host-pathogen interactions, the struggle for iron may have major consequences on the outcome of the disease. To overcome the low solubility and bio-availability of iron, bacteria have evolved multiple systems to acquire iron from various sources such as heme, hemoglobin and ferritin. The molecular basis of iron acquisition from heme and hemoglobin have been extensively studied; however, very little is known about iron acquisition from host ferritin, a 24-mer nanocage protein able to store thousands of iron atoms within its cavity. In the human opportunistic pathogen Bacillus cereus, a surface protein named IlsA (Iron-regulated leucine rich surface protein type A) binds heme, hemoglobin and ferritin in vitro and is involved in virulence. Here, we demonstrate that IlsA acts as a ferritin receptor causing ferritin aggregation on the bacterial surface. Isothermal titration calorimetry data indicate that IlsA binds several types of ferritins through direct interaction with the shell subunits. UV-vis kinetic data show a significant enhancement of iron release from ferritin in the presence of IlsA indicating for the first time that a bacterial protein might alter the stability of the ferritin iron core. Disruption of the siderophore bacillibactin production drastically reduces the ability of B. cereus to utilize ferritin for growth and results in attenuated bacterial virulence in insects. We propose a new model of iron acquisition in B. cereus that involves the binding of IlsA to host ferritin followed by siderophore assisted iron uptake. Our results highlight a possible interplay between a surface protein and a siderophore and provide new insights into host adaptation of B. cereus and general bacterial pathogenesis. PMID:24550730
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Directory of Open Access Journals (Sweden)
Diego Segond
2014-02-01
Full Text Available In host-pathogen interactions, the struggle for iron may have major consequences on the outcome of the disease. To overcome the low solubility and bio-availability of iron, bacteria have evolved multiple systems to acquire iron from various sources such as heme, hemoglobin and ferritin. The molecular basis of iron acquisition from heme and hemoglobin have been extensively studied; however, very little is known about iron acquisition from host ferritin, a 24-mer nanocage protein able to store thousands of iron atoms within its cavity. In the human opportunistic pathogen Bacillus cereus, a surface protein named IlsA (Iron-regulated leucine rich surface protein type A binds heme, hemoglobin and ferritin in vitro and is involved in virulence. Here, we demonstrate that IlsA acts as a ferritin receptor causing ferritin aggregation on the bacterial surface. Isothermal titration calorimetry data indicate that IlsA binds several types of ferritins through direct interaction with the shell subunits. UV-vis kinetic data show a significant enhancement of iron release from ferritin in the presence of IlsA indicating for the first time that a bacterial protein might alter the stability of the ferritin iron core. Disruption of the siderophore bacillibactin production drastically reduces the ability of B. cereus to utilize ferritin for growth and results in attenuated bacterial virulence in insects. We propose a new model of iron acquisition in B. cereus that involves the binding of IlsA to host ferritin followed by siderophore assisted iron uptake. Our results highlight a possible interplay between a surface protein and a siderophore and provide new insights into host adaptation of B. cereus and general bacterial pathogenesis.
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International Nuclear Information System (INIS)
Arabani, M.; Mirabdolazimi, S.M.
2011-01-01
Research highlights: → This paper presents the first model of the fatigue behaviour of iron-asphalt mixtures in the world. → This model is able to describe the fatigue behaviour of iron-asphalt under dynamic loading. → Coarse surface, high stiffness and angularity of iron powder lead to enhanced fatigue performance. → The model illustrates that the use of iron powder has a considerable effect on tensile strain of HMA. → The use of this type of waste material could be a helpful solution for less polluted environment. - Abstract: The use of additives and admixtures in the construction of asphalt concrete pavements to strengthen them against dynamic loads has increased considerably in recent years. Recent research has shown that employing desirable waste materials in hot mix asphalts (HMAs) improves their dynamic properties noticeably. The study of some special cases, such as the addition of blast furnace slag and metallic materials of waste electronic instruments to HMA, has led to a considerable increase in the ability of HMAs to tolerate fatigue phenomena and repeated loading. Based on experimental studies, a model is proposed to describe the fatigue behaviour of asphalt mixtures containing waste iron powder. The results of this research show an important increase in the strength of asphalt mixtures containing waste iron powder against fatigue phenomena in comparison to conventional HMAs.
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Kinetics of chromium (VI) reduction by ferrous iron
International Nuclear Information System (INIS)
Batchelor, B.; Schlautman, M.; Hwang, I.; Wang, R.
1998-09-01
Chromium is a primary inorganic contaminant of concern at the Pantex Plant. Chromium concentrations have been found to be two orders of magnitude higher than the drinking water standards, particularly in certain wells in the perched aquifer below Zone 12. In situ reduction of a mobile form of chromium, Cr(VI) to an immobile form, Cr(III), was examined as a viable option to active soil restoration. Successfully immobilizing chromium in the vadose zone as Cr(III) will reduce the amount of chromium that reaches the groundwater table. The results from the solution experiments indicated that chromium was rapidly and stoichiometrically reduced by Fe(II) in solution. Also, the slurry experiments showed that the aquifer solids removed Fe(II) from solution, but a portion of the iron removed remained available for reaction with Cr(VI), but at a slower rate. A model to predict different amounts of iron pseudo-components was developed, which allowed prediction of iron amounts required to reduce chromium under in situ conditions
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Venlafaxine and desvenlafaxine in the management of menopausal hot flashes
Directory of Open Access Journals (Sweden)
Johnson ED
2011-09-01
Full Text Available Vasomotor flushes are common complaints of women during and after menopause, affecting about 75 percent of this population. Estrogen therapy is the most effective treatment for hot flashes. However, there are a significant number of women who have contraindications or choose not to use estrogen due to potential risks such as breast cancer and thromboembolic disorders. These women need alternative options. The selective norepinephrine reuptake inhibitors, venlafaxine and desvenlafaxine, have shown efficacy in alleviating hot flashes.Objective: The purpose of this review is to assess the efficacy and tolerability of these two agents for treatment of hot flashes in healthy postmenopausal women.Methods: A literature search of the MEDLINE and Ovid databases from inception to June 2011 was conducted. Randomized controlled trials, published in English, with human participants were included. Studies included postmenopausal women, and trials with breast cancer only populations were excluded.Results: Venlafaxine reduced hot flashes by 37 to 61 percent and desvenlafaxine by 55 to 69 percent. Both agents were well tolerated. The most common adverse effects were headache, dry mouth, nausea, insomnia, somnolence, and dizziness.Conclusion: Based on the evidence, venlafaxine and desvenlafaxine are both viable options for reducing the frequency and severity of hot flashes.
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DEFF Research Database (Denmark)
Lund, Henriette Romme
En undersøgelse af, hvad der er hot - og burde være hot på læseområdet. I undersøgelsen deltager 21 læsekyndige fra praksisfeltet, professionshøjskolerne og forskningsområdet.......En undersøgelse af, hvad der er hot - og burde være hot på læseområdet. I undersøgelsen deltager 21 læsekyndige fra praksisfeltet, professionshøjskolerne og forskningsområdet....
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Tribological Behavior of Laser Textured Hot Stamping Dies
Directory of Open Access Journals (Sweden)
Andre Shihomatsu
2016-01-01
Full Text Available Hot stamping of high strength steels has been continuously developed in the automotive industry to improve mechanical properties and surface quality of stamped components. One of the main challenges faced by researchers and technicians is to improve stamping dies lifetime by reducing the wear caused by high pressures and temperatures present during the process. This paper analyzes the laser texturing of hot stamping dies and discusses how different surfaces textures influence the lubrication and wear mechanisms. To this purpose, experimental tests and numerical simulation were carried out to define the die region to be texturized and to characterize the textured surface topography before and after hot stamping tests with a 3D surface profilometer and scanning electron microscopy. Results showed that laser texturing influences the lubrication at the interface die-hot sheet and improves die lifetime. In this work, the best texture presented dimples with the highest diameter, depth, and spacing, with the surface topography and dimples morphology practically preserved after the hot stamping tests.
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Iron inhibits respiratory burst of peritoneal phagocytes in vitro
DEFF Research Database (Denmark)
Gotfryd, Kamil; Jurek, Aleksandra; Kubit, Piotr
2011-01-01
Objective. This study examines the effects of iron ions Fe(3+) on the respiratory burst of phagocytes isolated from peritoneal effluents of continuous ambulatory peritoneal dialysis (CAPD) patients, as an in vitro model of iron overload in end-stage renal disease (ESRD). Material and Methods....... Respiratory burst of peritoneal phagocytes was measured by chemiluminescence method. Results. At the highest used concentration of iron ions Fe(3+) (100 µM), free radicals production by peritoneal phagocytes was reduced by 90% compared to control. Conclusions. Iron overload may increase the risk of infectious...
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Iron Abundance in the Prototype PG 1159 Star, GW Vir Pulsator PG 1159-035, and Related Objects
Werner, K.; Rauch, T.; Kruk, J. W.; Kurucz, R. L.
2011-01-01
We performed an iron abundance determination of the hot, hydrogen deficient post-AGB star PG 1159-035. which is the prototype of the PG 1159 spectral class and the GW Vir pulsators, and of two related objects (PG 1520+525, PG 1144+005), based on the first detection of Fe VIII lines in stellar photospheres. In another PG 1159 star. PG 1424+535. we detect Fe VII lines. In all four stars, each within T(sub eff) = 110,000-150,000 K, we find a solar iron abundance. This result agrees with our recent abundance analysis of the hottest PG 1159 stars (T(sub eff) = 150,000-200,000 K) that exhibit Fe x lines. On the whole, we find that the PG 1159 stars are not significantly iron deficient, in contrast to previous notions.
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Yu, Wen-Bang; Ye, Bang-Ce
2016-05-01
Fusaricidins are a class of cyclic lipopeptide antibiotics that have strong antifungal activities against plant pathogenic fungi and excellent bactericidal activities against Gram-positive bacteria. The mechanism through which fusaricidin exerts its action is not yet entirely clear. To investigate the mode of action of fusaricidin, we determined the physiological and transcriptional responses of Bacillus subtilis to fusaricidin treatment by using a systems-level approach. Our data show that fusaricidin rapidly induced the expression of σ(W) regulon and caused membrane damage in B. subtilis. We further demonstrated that ferric ions play multiple roles in the action of fusaricidin on B. subtilis. Iron deprivation blocked the formation of hydroxyl radical in the cells and significantly inhibited the bactericidal activity of fusaricidin. Conversely, high levels of iron (>2 mM) repressed the expression of BkdR regulon, resulting in a smaller cellular pool of branched-chain precursors for iso- and anteiso-branched fatty acids, which in turn led to a decrease in the proportion of branched-chain fatty acids in the membrane of B. subtilis. This change in membrane composition reduced its bilayer fluidity and increased its resistance to antimicrobial agents. In conclusion, our experiments uncovered some novel interactions and a synergism between cellular iron levels and drug resistance in Gram-positive bacteria. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
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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
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Capture and storage of hydrogen gas by zero-valent iron.
Reardon, Eric J
2014-02-01
Granular Fe(o), used to reductively degrade a variety of contaminants in groundwater, corrodes in water to produce H2(g). A portion enters the Fe(o) lattice where it is stored in trapping sites such as lattice defects and microcracks. The balance is dissolved by the groundwater where it may exsolve as a gas if its solubility is exceeded. Gas exsolution can reduce the effectiveness of the Fe(o) treatment zone by reducing contact of the contaminant with iron surfaces or by diverting groundwater flow. It also represents a lost electron resource that otherwise could be involved in reductive degradation of contaminants. It is advantageous to select an iron for remediation purposes that captures a large proportion of the H2(g) it generates. This study examines various aspects of the H2(g) uptake process and has found 1) H2(g) does not have to be generated at the water/iron interface to enter the lattice. It can enter directly from the gas/water phases, 2) exposure of granular sponge iron to H2(g) reduces the dormant period for the onset of iron corrosion, 3) the large quantities of H2(g) generated by nano-Fe(o) injected into a reactive barrier of an appropriate granular iron can be captured in the lattice of that iron, and 4) lattice-bound hydrogen represents an additional electron resource to Fe(o) for remediation purposes and may be accessible using physical or chemical means. Copyright © 2013 Elsevier B.V. All rights reserved.
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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).
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Macharia-Mutie, C.W.; Moretti, D.; Briel, van den N.; Omusundi, A.M.; Mwangi, A.M.; Kok, F.J.; Zimmerman, J.B.; Brouwer, I.D.
2012-01-01
Few studies have evaluated the impact of fortification with iron-rich foods such as amaranth grain and multi-micronutrient powder (MNP) containing low doses of highly bioavailable iron to control iron deficiency anemia (IDA) in children. We assessed the efficacy of maize porridge enriched with
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Iron Requirement and Iron Uptake from Various Iron Compounds by Different Plant Species
Christ, Rudolf A.
1974-01-01
The Fe requirements of four monocotyledonous plant species (Avena sativa L., Triticum aestivum L., Oryza sativa L., Zea mays L.) and of three dicotyledonous species (Lycopersicum esculentum Mill., Cucumis sativus L., Glycine maxima (L.) Merr.) in hydroponic cultures were ascertained. Fe was given as NaFe-EDDHA chelate (Fe ethylenediamine di (O-hydroxyphenylacetate). I found that the monocotyledonous species required a substantially higher Fe concentration in the nutrient solution in order to attain optimum growth than did the dicotyledonous species. Analyses showed that the process of iron uptake was less efficient with the monocotyledonous species. When the results obtained by using chelated Fe were compared with those using ionic Fe, it was shown that the inefficient species were equally inefficient in utilizing Fe3+ ions. However, the differences between the efficient and the inefficient species disappeared when Fe2+ was used. This confirms the work of others who postulated that Fe3+ is reduced before uptake of chelated iron by the root. In addition, it was shown that reduction also takes place when Fe is used in ionic form. The efficiency of Fe uptake seems to depend on the efficiency of the root system of the particular plant species in reducing Fe3+. The removal of Fe from the chelate complex after reduction to Fe2+ seems to present no difficulties to the various plant species. PMID:16658933
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International Nuclear Information System (INIS)
Henssen, J.; Mauersberger, R.
1990-01-01
The flow conditions in the hot-gas plenum and in the adjacent hot-gas ducts and hot-gas pipes for the high-temperature reactor project PNP-1000 (nuclear process heat project for 1000 MW thermal output) have been examined experimentally. The experiments were performed in a closed loop in which the flow model to be analyzed, representing a 60deg sector of the core bottom of the PNP-1000 with connecting hot-gas piping and diverting arrangements, was installed. The model scale was approx. 1:5.6. The temperature and flow velocity distribution in the hot-gas duct was registered by means of 14 dual hot-wire flowmeters. Through structural changes and/or the installation of internals into the hot-gas plenum of the core bottom offering little flow resistance coolant gas temperature differentials produced in the core could be reduced to such an extent that a degree of mixture amounting to over 80% was achieved at the entrance of the connected heat exchanger systems. Thereby the desired goal of an adequate degree of mixture of the hot gas involving an acceptable pressure loss was reached. (orig.)
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International Nuclear Information System (INIS)
Sun, Yongqi; Seetharaman, Seshadri; Liu, Qianyi; Zhang, Zuotai; Liu, Lili; Wang, Xidong
2016-01-01
In this study, the thermodynamics of a novel strategy, i.e., biomass/CO 2 gasification integrated with heat recovery from hot slags in the steel industry, were systemically investigated. Both the target syngas yield and the polluting gas release were considered where the effect of gasifying conditions including temperature, pressure and CO 2 reacted was analyzed and then the roles of hot slags were further clarified. The results indicated that there existed an optimum temperature for the maximization of H 2 production. Compared to blast furnace slags, steel slags remarkably increased the CO yield at 600–1400 °C due to the existence of iron oxides and decreased the S-containing gas releases at 400–700 °C, indicating potential desulfurizing ability. The identification of biomass/CO 2 gasification thermodynamics in presence of slags could thus provide important clues not only for the deep understanding of biomass gasification but also for the industrial application of this emerging strategy from the viewpoint of syngas optimization and pollution control. - Highlights: • Biomass/CO 2 gasification was integrated with the heat recovery from hot slags. • Both syngas yield and polluting gas release during gasification were determined. • There existed an optimum temperature for the maximization of H 2 production. • Steel slags increased CO yield at 600–1400 °C due to the existence of iron oxides. • Steel slags remarkably decreased the releases of S-containing gas at 400–700 °C.
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Serum Iron Protects from Renal Postischemic Injury.
Vaugier, Céline; Amano, Mariane T; Chemouny, Jonathan M; Dussiot, Michael; Berrou, Claire; Matignon, Marie; Ben Mkaddem, Sanae; Wang, Pamella H M; Fricot, Aurélie; Maciel, Thiago T; Grapton, Damien; Mathieu, Jacques R R; Beaumont, Carole; Peraldi, Marie-Noëlle; Peyssonnaux, Carole; Mesnard, Laurent; Daugas, Eric; Vrtovsnik, François; Monteiro, Renato C; Hermine, Olivier; Ginzburg, Yelena Z; Benhamou, Marc; Camara, Niels O S; Flamant, Martin; Moura, Ivan C
2017-12-01
Renal transplants remain a medical challenge, because the parameters governing allograft outcome are incompletely identified. Here, we investigated the role of serum iron in the sterile inflammation that follows kidney ischemia-reperfusion injury. In a retrospective cohort study of renal allograft recipients ( n =169), increased baseline levels of serum ferritin reliably predicted a positive outcome for allografts, particularly in elderly patients. In mice, systemic iron overload protected against renal ischemia-reperfusion injury-associated sterile inflammation. Furthermore, chronic iron injection in mice prevented macrophage recruitment after inflammatory stimuli. Macrophages cultured in high-iron conditions had reduced responses to Toll-like receptor-2, -3, and -4 agonists, which associated with decreased reactive oxygen species production, increased nuclear localization of the NRF2 transcription factor, increased expression of the NRF2-related antioxidant response genes, and limited NF- κ B and proinflammatory signaling. In macrophage-depleted animals, the infusion of macrophages cultured in high-iron conditions did not reconstitute AKI after ischemia-reperfusion, whereas macrophages cultured in physiologic iron conditions did. These findings identify serum iron as a critical protective factor in renal allograft outcome. Increasing serum iron levels in patients may thus improve prognosis of renal transplants. Copyright © 2017 by the American Society of Nephrology.
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Hori, Tomoyuki; Aoyagi, Tomo; Itoh, Hideomi; Narihiro, Takashi; Oikawa, Azusa; Suzuki, Kiyofumi; Ogata, Atsushi; Friedrich, Michael W; Conrad, Ralf; Kamagata, Yoichi
2015-01-01
Reduction of crystalline Fe(III) oxides is one of the most important electron sinks for organic compound oxidation in natural environments. Yet the limited number of isolates makes it difficult to understand the physiology and ecological impact of the microorganisms involved. Here, two-stage cultivation was implemented to selectively enrich and isolate crystalline iron(III) oxide reducing microorganisms in soils and sediments. Firstly, iron reducers were enriched and other untargeted eutrophs were depleted by 2-years successive culture on a crystalline ferric iron oxide (i.e., goethite, lepidocrocite, hematite, or magnetite) as electron acceptor. Fifty-eight out of 136 incubation conditions allowed the continued existence of microorganisms as confirmed by PCR amplification. High-throughput Illumina sequencing and clone library analysis based on 16S rRNA genes revealed that the enrichment cultures on each of the ferric iron oxides contained bacteria belonging to the Deltaproteobacteria (mainly Geobacteraceae), followed by Firmicutes and Chloroflexi, which also comprised most of the operational taxonomic units (OTUs) identified. Venn diagrams indicated that the core OTUs enriched with all of the iron oxides were dominant in the Geobacteraceae while each type of iron oxides supplemented selectively enriched specific OTUs in the other phylogenetic groups. Secondly, 38 enrichment cultures including novel microorganisms were transferred to soluble-iron(III) containing media in order to stimulate the proliferation of the enriched iron reducers. Through extinction dilution-culture and single colony isolation, six strains within the Deltaproteobacteria were finally obtained; five strains belonged to the genus Geobacter and one strain to Pelobacter. The 16S rRNA genes of these isolates were 94.8-98.1% identical in sequence to cultured relatives. All the isolates were able to grow on acetate and ferric iron but their physiological characteristics differed considerably in
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International Nuclear Information System (INIS)
Mouri, Hayato; Wunderlich, Wilfried; Hayashi, Morihito
2009-01-01
Spherical ductile cast iron (FCD400) is widely used as container material in nuclear energy processing line due to its superior mechanical properties and low price. Fatigue properties in low cycle fatigue (LCF) can be described well by the Manson-Coffin-Basquin's rule. However, at intermediate temperature range between 453 and 723 K the elongation-temperature-diagram shows a significantly 20-10% reduced elongation and an increase in yield stress in tensile test experiments. These non-linear deviations and the phenomenon of less ductility at intermediate temperatures are known for a long time [K. Chijiiwa, M. Hayashi, Mechanical properties of ductile cast iron at temperature in the region of room temperature to liquid, Imono 51 (7) (2004) 395-400]. But the following explanation is presented for the first time. In the same temperature range as the reduced fatigue life time dynamic strain ageing (DSA) also known as Portevin-le-Chartelier effect with the formation of visible serrations occurs. Both phenomena are explained by interaction effects between carbon diffusion and dislocation velocity which have at this temperature the same order of magnitude. However, this phenomenon shows interesting behavior at intermediate temperature range. During the low cycle fatigue test, DSA phenomenon disappeared, but mechanical properties show clear evidence of DSA phenomenon. Therefore, the purpose of this paper is to study the correlation of DSA occurrence, LCF and mechanical properties.
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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)
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New technologies and raw materials for iron and steel making
Energy Technology Data Exchange (ETDEWEB)
Holappa, L. [Helsinki Univ. of Technology, Otaniemi (Finland). Lab. of Metallurgy
1998-07-01
The current steelmaking is still mainly based on two alternatives routes. The first one is ore based production route via reduction in blast furnaces (BF) to produce carbon-rich hot metal which is then oxidised in basic oxygen converter process (BOF) to crude steel, then refined and alloyed in several secondary (ladle) metallurgical operations to its final composition, further followed by continuous casting and rolling operations. The second main steelmaking route starts from steel scrap as the main raw material, melting of scrap in electric furnaces to crude steel, the subsequent stages being corresponding to those in ore based steelmaking. Both these processes represent well-established and highly developed technologies. However, they have some drawbacks. Blast furnace process needs sinter or pellets and coke as its raw materials. That means erection of large integrates with high investment costs in the production units themselves as well as to avoid severe environmental issues. Scrap-based steelmaking is ideal from the viewpoint of recycling, but it is limited by the scrap availability and quality problems encountered by the noticeable metallic impurities in purchase scrap. Direct reduction of iron ore in solid state to produce direct reduced iron (DRI) has its roots in the early ironmaking history but was firstly commercialised on a modern concept at the end of the 1960's when the first Midrex installation was run into operation. Most of the DR-processes utilise natural gas as the reducing agent but also some processes utilising coal have been introduced and are used in industrial scale. The oil crises in the 1970's slowed down the progress of DRI production but during the last 15 years the production has steadily grown being nowadays about 35 Mton/year. That corresponds to roughly 10 pct of the total solid material input into the world steel production. No doubt, the growth will continue in the near future as well. Quite recently, a new process
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sup(60)Co hot atom chemistry of tris(acetylacetonato) cobalt(III) adsorbed on silica gel
International Nuclear Information System (INIS)
Nishioji, H.; Sakai, Y.; Tominaga, T.
1985-01-01
The sup(60)Co hot atom reactions were studied in tris(acetylacetonato)cobalt(III) adsorbed on silica gel surface. sup(57)Fe Moessbauer spectra of tris(acetylacetonato)iron(III) in the corresponding system were also measured in order to examine the state of dispersion of complex molecules on silica gel. The retention formation processes were discussed in terms of the dependence of sup(60)Co retention on the adsorbed amount (concentration) of cobalt(III) complexes. (author)
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Effect of chronic ethanol administration on iron metabolism in the rat
International Nuclear Information System (INIS)
Sanchez, J.; Casas, M.; Rama, R.
1988-01-01
This study shows that the ingestion of ethanol provokes alterations in iron metabolism which may lead to iron overload. Impaired release of reticuloendothelial iron was shown by a decrease of the maximum red blood cell utilization when radioactive iron was supplied as colloidal iron. An impairment in the erythropoietic activity of ethanoltreated animals was also observed, as can be seen from the reduced plasma iron turnover and red blood cell utilization within 24 h of iron administration. A rise in marrow transit time was also observed. In ethanol-treated rats there was an increase in the amount of iron retained both in the liver and the spleen. This was observed in both sexes and also in the offspring from ethanol-treated mothers. (author)
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International Nuclear Information System (INIS)
Warnke, E.P.
1990-02-01
During this development program the thermodynamic behaviour of a system was investigated, consisting of a hot working Prestressed Cast Iron Pressure Vessel and an inactive heat sink in the surrounding cavern cell. It could be shown, that the inactive heat removal system designed as a natural circuit can remove the maximum amount of heat of 890 kW during emergency conditions via a natural-draught air cooling tower even under very conservative assumptions and for a 50% loss of cooling pipes. Further it could be shown, that the hot working Prestressed Cast Iron Pressure Vessel has a very safe load carrying behaviour during all normal and upset conditions. (orig.) With 10 tabs., 38 figs., 43 refs [de
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DEFF Research Database (Denmark)
Lund, Henriette
Undersøgelse af, hvad der er hot - og hvad der burde være hot på læseområdet med 21 læsekyndige. Undersøgelsen er gennemført siden 2010. HOT-undersøgelsen er foretaget af Nationalt Videncenter for Læsning - Professionshøjskolerne i samarb. med Dansklærerforeningen...
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IRON CHELATION THERAPY IN THALASSEMIA SYNDROMES
Directory of Open Access Journals (Sweden)
Paolo Cianciulli
2009-06-01
Full Text Available Transfusional hemosiderosis is a frequent complication in patients with transfusion dependent chronic diseases such as thalassemias and severe type of sickle cell diseases. As there are no physiological mechanisms to excrete the iron contained in transfused red cells (1 unit of blood contains approximately 200 mg of iron the excess of iron is stored in various organs. Cardiomyopathy is the most severe complication covering more than 70% of the causes of death of thalassemic patients. Although the current reference standard iron chelator deferoxamine (DFO has been used clinically for over four decades, its effectiveness is limited by a demanding therapeutic regimen that leads to poor compliance. Despite poor compliance, because of the inconvenience of subcutaneous infusion, DFO improved considerably the survival and quality of life of patients with thalassemia. Deferiprone since 1998 and Deferasirox since 2005 were licensed for clinical use. The oral chelators have a better compliance because of oral use, a comparable efficacy to DFO in iron excretion and probably a better penetration to myocardial cells. Considerable increase in iron excretion was documented with combination therapy of DFO and Deferiprone. The proper use of the three chelators will improve the prevention and treatment of iron overload, it will reduce complications, and improve survival and quality of life of transfused patients
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Arrieta-Aguirre, Inés; Menéndez-Manjón, Pilar; Cuétara, María Soledad; Fernández de Larrinoa, Iñigo; García-Ruiz, Juan Carlos; Moragues, María Dolores
2018-02-01
Saprochaete capitata , formerly known as Geotrichum capitatum , is an emerging fungal pathogen with low susceptibility to echinocandins. Here, we report the nucleotide sequence of the S. capitata hot spot 1 region of the FKS gene ( FKS HS1), which codifies for the catalytic subunit of β-1,3-d-glucan synthase, the target of echinocandins. For that purpose, we first designed degenerated oligonucleotide primers derived from conserved flanking regions of the FKS1 HS1 segment of 12 different fungal species. Interestingly, analysis of the translated FKS HS1 sequences of 12 isolates of S. capitata revealed that all of them exhibited the same F-to-L substitution in a position that is highly related to reduced echinocandin susceptibility. Copyright © 2018 American Society for Microbiology.
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Ren, M.; Xu, X.; Ermolieva, T.; Cao, G.-Y.; Yermoliev, Y.
2018-01-01
China is the world’s largest iron and steel producer and Jing-Jin-Ji (Beijing-Tianjin-Hebei) region accounts for nearly 1/3 of the national iron and steel production, while it is facing serious air pollution. Among the top 10 worst polluted cities in China, seven were located in Hebei province in 2014. Recent years Jing-Jin-Ji region has been promoted iron & steel industry with green clean technology for accelerating sustainable economic transition. This paper tries to response the basic ques...
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Energy Technology Data Exchange (ETDEWEB)
Passos, Sergio R.M.; Furtado, Henrique S.; Bentes, Miguel A.G.; Almeida, Pedro S. de [Companhia Siderurgica Nacional, Volta Redonda, RJ (Brazil). Centro de Pesquisas
1996-12-31
The attractiveness of hot metal de siliconizing in ladle, relative to the process in blast furnace runner, is the previous knowledge of silicon content of hot metal, without the constraints of slag removing by skimmer met in torpedo car, and the better efficiency in low range silicon content, making easier the process controllability. Meanwhile, the main question about this technology is the extent of the resulfurization of hot metal that may occur due to process be performed after the desulfurization. This work simulates de de siliconizing process in ladle by experiments in induction furnace to compare the efficiencies of various de siliconizing agents available at CSN iron and steel making plant, and to evaluate the resulfurization intensity able to occur during the process, as well as, unexpected increasing of refractory wear. (author) 4 refs., 8 figs., 6 tabs.
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International Nuclear Information System (INIS)
Xie, Fangxi; Hong, Wei; Su, Yan; Zhang, Miaomiao; Jiang, Beiping
2017-01-01
Highlights: • Effect of hot EGR on combustion and PN emission is investigated on a GDI engine. • Appropriate addition of hot EGR can reduce fuel consumption, NO_x and PN emission. • Relationship between BSFC and emissions of hot EGR is better than cooled EGR. • Condition with low-medium speeds and medium loads are more suitable for hot EGR. - Abstract: In this paper, an experimental investigation about the influence of hot EGR addition on the engine combustion, performance and particulate number emission was conducted at a spark-ignition gasoline direct injection (GDI) engine. Meanwhile, the different effects between cooled and hot EGR addition methods were compared and the variations of fuel consumption and particle number emissions under six engine operating conditions with different speeds and loads were analyzed. The research result indicated that increasing hot EGR ratio properly with adjustment of ignition timing could effectively improve the relationship among brake-specific fuel consumption (BSFC), NO_x and particle number emissions. When hot EGR ratio increased to 20%, not only BSFC but also the NO_x and particle number emissions were reduced, which were about 7%, 87% and 36% respectively. Compared with cooled EGR, the flame development and propagation speeds were accelerated, and cycle-by-cycle combustion variation decreased with hot EGR. Meanwhile, using hot EGR made the engine realize a better relationship among fuel consumption, NO_x and particle number emissions. The biggest improvements of BSFC, NO_x and particle number emissions were obtained at low-medium speed and medium load engine conditions by hot EGR addition method. While engine speed increased and load decreased, the improvement of engine fuel consumption and emission reduced with hot EGR method.
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International Nuclear Information System (INIS)
Valenti, M.
1996-01-01
This article describes a hazardous waste treatment known as the catalytic extraction process, which also stabilizes and reduces low-level radioactive wastes to a fraction of their original volume, easing their disposal. It uses molten iron and other metals to convert hazardous wastes into useful materials
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Dynamics of Phenol Degrading-Iron ReducingBacteria{1mm in Intensive Rice Cropping System
Institute of Scientific and Technical Information of China (English)
无
2001-01-01
Field and greenhouse experiments were conducted to investigate theeffects of cropping season, nitrogen fertilizer input and aeratedfallow on the dynamics of phenol degrading-iron reducingbacteria (PD-IRB) in tropical irrigated rice ({ Oryza sativa L.)systems. The PD-IRB population density was monitored at different stagesof rice growth in two cropping seasons (dry and early wet) in acontinuous annual triple rice cropping system under irrigated condition.In this system, the high nitrogen input (195 and 135 kg N ha-1 indry and wet seasons, respectively) plots and control plots receiving noN fertilizer were compared to investigate the effect of nitrogen rate onpopulation size. The phenol degrading-iron reducing bacteria (PD-IRB)were abundant in soils under cropping systems of tropical irrigatedrice. However, density of the bacterial populations varied with ricegrowth stages. Cropping seasons, rhizosphere, and aerated fallow couldaffect the dynamics of PD-IRB. In the field trial, viable counts ofPD-IRB in the topsoil layer (15 cm) ranged between 102 and 108cells per gram of dry soil. A steep increase in viable counts during thesecond half of the cropping season suggested that the population densityof PD-IRB increased at advanced crop-growth stages. Population growth ofPD-IRB was accelerated during the dry season compared to the wet season.In the greenhouse experiment, the adjacent aerated fallow revealed 1-2orders of magnitude higher in most probable number (MPN) of PD-IRB thanthe wet fallow treated plots. As a prominent group of Fe reducingbacteria, PD-IRB predominated in the rhizosphere of rice, since maximumMPN of PD-IRB (2.62108 g-1 soil) was found in rhizospheresoil. Mineral N fertilizer rates showed no significant effect on PD-IRBpopulation density.
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Chemical fingerprints of hot Jupiter planet formation
Maldonado, J.; Villaver, E.; Eiroa, C.
2018-05-01
Context. The current paradigm to explain the presence of Jupiter-like planets with small orbital periods (P involves their formation beyond the snow line following inward migration, has been challenged by recent works that explore the possibility of in situ formation. Aims: We aim to test whether stars harbouring hot Jupiters and stars with more distant gas-giant planets show any chemical peculiarity that could be related to different formation processes. Methods: Our methodology is based on the analysis of high-resolution échelle spectra. Stellar parameters and abundances of C, O, Na, Mg, Al, Si, S, Ca, Sc, Ti, V, Cr, Mn, Co, Ni, Cu, and Zn for a sample of 88 planet hosts are derived. The sample is divided into stars hosting hot (a 0.1 au) Jupiter-like planets. The metallicity and abundance trends of the two sub-samples are compared and set in the context of current models of planet formation and migration. Results: Our results show that stars with hot Jupiters have higher metallicities than stars with cool distant gas-giant planets in the metallicity range +0.00/+0.20 dex. The data also shows a tendency of stars with cool Jupiters to show larger abundances of α elements. No abundance differences between stars with cool and hot Jupiters are found when considering iron peak, volatile elements or the C/O, and Mg/Si ratios. The corresponding p-values from the statistical tests comparing the cumulative distributions of cool and hot planet hosts are 0.20, products from observations made with ESO Telescopes at the La Silla Paranal Observatory under programme ID 072.C-0033(A), 072.C-0488(E), 074.B-0455(A), 075.C-0202(A), 077.C-0192(A), 077.D-0525(A), 078.C-0378(A), 078.C-0378(B), 080.A-9021(A), 082.C-0312(A) 082.C-0446(A), 083.A-9003(A), 083.A-9011(A), 083.A-9011(B), 083.A-9013(A), 083.C-0794(A), 084.A-9003(A), 084.A-9004(B), 085.A-9027(A), 085.C-0743(A), 087.A-9008(A), 088.C-0892(A), 089.C-0440(A), 089.C-0444(A), 089.C-0732(A), 090.C-0345(A), 092.A-9002(A), 192.C-0852
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Formation of coatings from a liquid phase on the surface of iron-base alloys
Directory of Open Access Journals (Sweden)
A. Tatarek
2008-12-01
Full Text Available The study discloses the present state of the art regarding the technology and investigations of the phenomena that take place during the formation and growth of aluminum and zinc coatings hot-dip formed on iron products. In its cognitive aspect, the study offers an in-depth analysis of the partial processes that proceed in metal bath at the solid body – liquid metal interface. It is expected that the present study will help in a more detailed description of the respective phenomena and in full explanation of the mechanism of the coating growth, taking as an example the growth of aluminum coatings. The obtained results can serve as a background for some general conclusions regarding the thickness evolution process in other hot-dip coatings.
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International Nuclear Information System (INIS)
Silvestrini, G.
1992-01-01
This paper first identifies a significant and deleterious trend, in terms of poor energy efficiency and high carbon dioxide emissions, towards the increased use of electric water heaters for sanitary hot water production in single family units. It then points out how the use of wall mounted methane fired boilers can result in overall energy savings (overall electric power consumption for domestic hot water production is estimated to represent one- quarter of Italy's total domestic power demand), as well as air pollution abatement. The feasibility of other methods of energy conservation and pollution abatement in domestic water heating are also examined. These include the use of solar hot water heaters, computerized timers which allow users to program the operation of their heating plants, and the adoption by residential communities of methane fuelled district heating plants
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Energy Technology Data Exchange (ETDEWEB)
Valdez, D H; Kuizon, M D; Marero, L M; Mallillin, A C; Cruz, E M; Madriaga, J R [Department of Science and Technology, Manila (Philippines). Food and Nutrition Research Inst.
1994-12-31
Iron bioavailability from weaning foods prepared from 70:30 combination of germinated rice:mungbean (GRM); germinated rice: cowpea (GRC) and germinated corn:mungbean (GCM) was determined by radioisotopic measurements of iron absorption in human subjects. The gruels were prepared as plain with sugar and flavoring labeled by the extrinsic tag method, and served as hot porridge. It was estimated that iron-deficient infants would absorb 3.5% from GRM, 4.9% from GRC and 5.6% from GCM. Differences between absorption among the weaning foods were not statistically significant. Planning of diets for these age group should include other sources of iron especially heme. Zinc absorption from the weaning food formulations will be studied by the in vitro and in vivo methods. For the in vivo method on human subjects, the absorption of zinc will be determined from the measurement of the whole body retention of the isotope 14 days after intake of the labeled mean. Serum zinc level will be determined to assess the zinc status of the subjects. (author). 23 refs, 1 fig., 4 tabs.
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International Nuclear Information System (INIS)
Valdez, D.H.; Kuizon, M.D.; Marero, L.M.; Mallillin, A.C.; Cruz, E.M.; Madriaga, J.R.
1994-01-01
Iron bioavailability from weaning foods prepared from 70:30 combination of germinated rice:mungbean (GRM); germinated rice: cowpea (GRC) and germinated corn:mungbean (GCM) was determined by radioisotopic measurements of iron absorption in human subjects. The gruels were prepared as plain with sugar and flavoring labeled by the extrinsic tag method, and served as hot porridge. It was estimated that iron-deficient infants would absorb 3.5% from GRM, 4.9% from GRC and 5.6% from GCM. Differences between absorption among the weaning foods were not statistically significant. Planning of diets for these age group should include other sources of iron especially heme. Zinc absorption from the weaning food formulations will be studied by the in vitro and in vivo methods. For the in vivo method on human subjects, the absorption of zinc will be determined from the measurement of the whole body retention of the isotope 14 days after intake of the labeled mean. Serum zinc level will be determined to assess the zinc status of the subjects. (author). 23 refs, 1 fig., 4 tabs
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PCBP1 and NCOA4 regulate erythroid iron storage and heme biosynthesis.
Ryu, Moon-Suhn; Zhang, Deliang; Protchenko, Olga; Shakoury-Elizeh, Minoo; Philpott, Caroline C
2017-05-01
Developing erythrocytes take up exceptionally large amounts of iron, which must be transferred to mitochondria for incorporation into heme. This massive iron flux must be precisely controlled to permit the coordinated synthesis of heme and hemoglobin while avoiding the toxic effects of chemically reactive iron. In cultured animal cells, iron chaperones poly rC-binding protein 1 (PCBP1) and PCBP2 deliver iron to ferritin, the sole cytosolic iron storage protein, and nuclear receptor coactivator 4 (NCOA4) mediates the autophagic turnover of ferritin. The roles of PCBP, ferritin, and NCOA4 in erythroid development remain unclear. Here, we show that PCBP1, NCOA4, and ferritin are critical for murine red cell development. Using a cultured cell model of erythroid differentiation, depletion of PCBP1 or NCOA4 impaired iron trafficking through ferritin, which resulted in reduced heme synthesis, reduced hemoglobin formation, and perturbation of erythroid regulatory systems. Mice lacking Pcbp1 exhibited microcytic anemia and activation of compensatory erythropoiesis via the regulators erythropoietin and erythroferrone. Ex vivo differentiation of erythroid precursors from Pcbp1-deficient mice confirmed defects in ferritin iron flux and heme synthesis. These studies demonstrate the importance of ferritin for the vectorial transfer of imported iron to mitochondria in developing red cells and of PCBP1 and NCOA4 in mediating iron flux through ferritin.
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A new environment-friendly hot pepper variety "Shiyan No. 1"
Han, Jianming; Xu, Shuzhen; Wang, Ruiling; Zhang, Yanzhao; Yun, Chao
2018-04-01
Hot pepper has rich genetic diversity which is the important base of breeding of new variety, and it is also one of the important vegetable in the word. In this study, we bred the "Shiyan No. 1" environment-friendly hot pepper variety using hybrid method on the basis of hot pepper genetic diversity. "Shiyan No. 1" is a new F1 hybrid of hot pepper variety with mid-early maturity. The new variety has a high productivity of 3000-5000kg(667m2)-1 with thick oxhorn shape fruits, green skin, thick flesh, mild-hot taste, good quality and marketable characters. It can reduce chemical pesticides usage and thereby protect environment because it is resistant to virus disease, highly resistant to phytophthora blight, anthracnose and bacterial wilt. In conclusion, the new bred "Shiyan No.1" is suitable for protected cultivation and open field cultivation in China.
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Inoculation Effects of Cast Iron
Directory of Open Access Journals (Sweden)
E. Fraś
2012-12-01
Full Text Available The paper presents a solidification sequence of graphite eutectic cells of A and D types, as well as globular and cementite eutectics. The morphology of eutectic cells in cast iron, the equations for their growth and the distances between the graphite precipitations in A and D eutectic types were analyzed. It is observed a critical eutectic growth rate at which one type of eutectic transformed into another. A mathematical formula was derived that combined the maximum degree of undercooling, the cooling rate of cast iron, eutectic cell count and the eutectic growth rate. One type of eutectic structure turned smoothly into the other at a particular transition rate, transformation temperature and transformational eutectic cell count. Inoculation of cast iron increased the number of eutectic cells with flake graphite and the graphite nodule count in ductile iron, while reducing the undercooling. An increase in intensity of inoculation caused a smooth transition from a cementite eutectic structure to a mixture of cementite and D type eutectic structure, then to a mixture of D and A types of eutectics up to the presence of only the A type of eutectic structure. Moreover, the mechanism of inoculation of cast iron was studied.
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Italia, Khushnooma; Chandrakala, S; Ghosh, Kanjaksha; Colah, Roshan
2016-09-01
In this study, we hypothesize that hydroxyurea could provide an additional benefit as a free radical scavenger and/or iron chelator in β-thalassemia patients with iron overload. Twenty-one β-thalassemia intermedia patients who presented between 3 and 17 years but later required regular blood transfusions were enrolled for hydroxyurea therapy for a year. Fourteen patients responded to the therapy with hemoglobin levels maintained above 7.5 g/dl without transfusions. Hydroxyurea was discontinued after 6 months in seven patients who did not respond to the therapy and had to be continued on regular blood transfusions. We observed a statistically significant decrease in serum ferritin levels from 4194 ± 4850 ng/ml to 2129 ± 2380 ng/ml among the responders and from 2955 ± 2909 ng/ml to 2040 ± 2432 ng/ml among the non-responders and statistically significant decrease in labile iron pool from 18678.7 ± 10067.4 mean fluorescence intensity (MFI) to 14888.5 ± 5284.0 MFI among responders and from 17986.3 ± 9079.8 MFI to 15634.8 ± 8976.9 MFI among the non-responders after therapy. Phosphatidylserine externalization also showed a statistically significant decrease from 44.2 ± 22.2 MFI to 16.6 ± 6.7 MFI among the responders and from 46.9 ± 33.1 MFI to 39.8 ± 7.4 MFI among the non-responders along with a statistically significant decrease in the levels of reactive oxygen species from 72.8 ± 35.5 MFI to 29.0 ± 8.3 MFI among the responders and from 80.9 ± 41.4 MFI to 40.5 ± 15.8 MFI among the non-responders after therapy. A statistically significant increase in reduced glutathione levels was also observed from 430.8 ± 201.1 MFI to 715.5 ± 292.4 MFI among the responders and from 359.6 ± 165.6 MFI to 450.3 ± 279.5 MFI among the non-responders after therapy. This suggests the possible additional role of hydroxyurea as a free radical scavenger and
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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
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Sulfur-Modified Zero-Valent Iron for Remediation Applications at DOE Sites - 13600
Energy Technology Data Exchange (ETDEWEB)
Fogwell, Thomas W. [Fogwell Consulting, P.O. Box 20221, Piedmont, CA 94620 (United States); Santina, Pete [SMI-PS, Inc., 2073 Prado Vista, Lincoln, CA 95648 (United States)
2013-07-01
Many DOE remediation sites have chemicals of concern that are compounds in higher oxidation states, which make them both more mobile and more toxic. The chemical reduction of these compounds both prevents the migration of these chemicals and in some cases reduces the toxicity. It has also been shown that zero-valent iron is a very effective substance to use in reducing oxygenated compounds in various treatment processes. These have included the treatment of halogenated hydrocarbons in the form volatile organic compounds used as solvents and pesticides. Zero-valent iron has also been used to reduce various oxidized metals such as chromium, arsenic, and mercury in order to immobilize them, decrease their toxicity, and prevent further transport. In addition, it has been used to immobilize or break down other non-metallic species such as selenium compounds and nitrates. Of particular interest at several DOE remediation sites is the fact that zero-valent iron is very effective in immobilizing several radioactive metals which are mobile in their oxidized states. These include both technetium and uranium. The main difficulty in using zero-valent iron has been its tendency to become inactive after relatively short periods of time. While it is advantageous to have the zero-valent iron particles as porous as possible in order to provide maximum surface area for reactions to take place, these pores can become clogged when the iron is oxidized. This is due to the fact that ferric oxide has a greater volume for a given mass than metallic iron. When the surfaces of the iron particles oxidize to ferric oxide, the pores become narrower and will eventually shut. In order to minimize the degradation of the chemical activity of the iron due to this process, a modification of zero-valent iron has been developed which prevents or slows this process, which decreases its effectiveness. It is called sulfur-modified iron, and it has been produced in high purity for applications in
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Pecavar, Verena; Blaschitz, Marion; Hufnagl, Peter; Zeinzinger, Josef; Fiedler, Anita; Allerberger, Franz; Maass, Matthias; Indra, Alexander
2012-06-01
Clostridium difficile, a Gram-positive, spore-forming, anaerobic bacterium, is the main causative agent of hospital-acquired diarrhoea worldwide. In addition to metronidazole and vancomycin, rifaximin, a rifamycin derivative, is a promising antibiotic for the treatment of recurring C. difficile infections (CDI). However, exposure of C. difficile to this antibiotic has led to the development of rifaximin-resistance due to point mutations in the β-subunit of the RNA polymerase (rpoB) gene. In the present study, 348 C. difficile strains with known PCR-ribotypes were investigated for respective single nucleotide polymorphisms (SNPs) within the proposed rpoB hot-spot region by using high-resolution melting (HRM) analysis. This method allows the detection of SNPs by comparing the altered melting behaviour of dsDNA with that of wild-type DNA. Discrimination between wild-type and mutant strains was enhanced by creating heteroduplexes by mixing sample DNA with wild-type DNA, leading to characteristic melting curve shapes from samples containing SNPs in the respective rpoB section. In the present study, we were able to identify 16 different rpoB sequence-types (ST) by sequencing analysis of a 325 bp fragment. The 16 PCR STs displayed a total of 24 different SNPs. Fifteen of these 24 SNPs were located within the proposed 151 bp SNP hot-spot region, resulting in 11 different HRM curve profiles (CP). Eleven SNPs (seven of which were within the proposed hot-spot region) led to amino acid substitutions associated with reduced susceptibility to rifaximin and 13 SNPs (eight of which were within the hot-spot region) were synonymous. This investigation clearly demonstrates that HRM analysis of the proposed SNP hot-spot region in the rpoB gene of C. difficile is a fast and cost-effective method for the identification of C. difficile samples with reduced susceptibility to rifaximin and even allows simultaneous SNP subtyping of the respective C. difficile isolates.
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The impact of aqueous washing on the ability of βFeOOH to corrode iron.
Watkinson, D E; Emmerson, N J
2017-01-01
Controlling the corrosion of historical and archaeological ferrous metal objects presents a significant challenge to conservators. Chloride is a major corrosion accelerator in coastal areas for historic ferrous metal structures and for the many chloride-containing archaeological objects within museums. Corrosion reactions involve the formation of akaganéite (βFeOOH) which incorporates chloride within its crystal structure and adsorbs it onto its surface. The mobility of the surface-adsorbed chloride in aqueous systems and atmospheric moisture means βFeOOH can itself cause iron to corrode. The extraction of chloride from βFeOOH by aqueous Soxhlet hot wash and aqueous room temperature washing is measured. The impact of this washing on the ability of βFeOOH to corrode iron is quantitatively investigated by determining the oxygen consumption of unwashed, Soxhlet-washed and room temperature-washed samples of βFeOOH mixed with iron powder and exposed to 80 % relative humidity. This acts as a proxy measurement for the corrosion rate of iron. The results are discussed relative to climatic factors for outdoor heritage objects and the treatment of archaeological iron in museums. Delivering better understanding of the properties of βFeOOH supports the development of evidence-based treatments and management procedures in heritage conservation.
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HOT CELL SYSTEM FOR DETERMINING FISSION GAS RETENTION IN METALLIC FUELS
Energy Technology Data Exchange (ETDEWEB)
Sell, D. A.; Baily, C. E.; Malewitz, T. J.; Medvedev, P. G.; Porter, D. L.; Hilton, B. A.
2016-09-01
A system has been developed to perform measurements on irradiated, sodium bonded-metallic fuel elements to determine the amount of fission gas retained in the fuel material after release of the gas to the element plenum. During irradiation of metallic fuel elements, most of the fission gas developed is released from the fuel and captured in the gas plenums of the fuel elements. A significant amount of fission gas, however, remains captured in closed porosities which develop in the fuel during irradiation. Additionally, some gas is trapped in open porosity but sealed off from the plenum by frozen bond sodium after the element has cooled in the hot cell. The Retained fission Gas (RFG) system has been designed, tested and implemented to capture and measure the quantity of retained fission gas in characterized cut pieces of sodium bonded metallic fuel. Fuel pieces are loaded into the apparatus along with a prescribed amount of iron powder, which is used to create a relatively low melting, eutectic composition as the iron diffuses into the fuel. The apparatus is sealed, evacuated, and then heated to temperatures in excess of the eutectic melting point. Retained fission gas release is monitored by pressure transducers during the heating phase, thus monitoring for release of fission gas as first the bond sodium melts and then the fuel. A separate hot cell system is used to sample the gas in the apparatus and also characterize the volume of the apparatus thus permitting the calculation of the total fission gas release from the fuel element samples along with analysis of the gas composition.
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DEFF Research Database (Denmark)
Lund, Henriette Romme
En undersøgelse af, hvad der er hot - og burde være hot på læseområdet. I undersøgelsen deltager en række læsekyndige fra praksisfeltet, professionshøjskolerne og forskningsområdet. Undersøgelsen er gentaget hvert år siden 2010.......En undersøgelse af, hvad der er hot - og burde være hot på læseområdet. I undersøgelsen deltager en række læsekyndige fra praksisfeltet, professionshøjskolerne og forskningsområdet. Undersøgelsen er gentaget hvert år siden 2010....
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DEFF Research Database (Denmark)
Lund, Henriette Romme
En undersøgelse af, hvad der er hot - og burde være hot på læseområdet. I undersøgelsen deltager en række læsekyndige fra praksisfeltet, professionshøjskolerne og forskningsområdet. Undersøgelsen er gentaget hvert år siden 2010.......En undersøgelse af, hvad der er hot - og burde være hot på læseområdet. I undersøgelsen deltager en række læsekyndige fra praksisfeltet, professionshøjskolerne og forskningsområdet. Undersøgelsen er gentaget hvert år siden 2010....
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Suppression of sawtooth oscillations due to hot electrons and hot ions
International Nuclear Information System (INIS)
Zhang, Y.Z.; Berk, H.L.
1989-01-01
The theory of m = 1 kink mode stabilization is discussed in the presence of either magnetically trapped hot electrons or hot ions. For instability hot ion requires particles peaked inside the q = 1 surface, while hot electrons require that its pressure profile be increasing at the q = 1 surface. Experimentally observed sawtooth stabilization usually occurs with off-axis heating with ECRH and near axis heating with ICRH. Such heating may produce the magnetically trapped hot particle pressure profiles that are consistent with theory. 17 refs., 2 figs
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Diffusion of hydrogen in iron oxides
International Nuclear Information System (INIS)
Bruzzoni, P.
1993-01-01
The diffusion of hydrogen in transitions metals oxides has been recently studied at room temperature through the permeability electrochemical technique. This work studies thin oxide layers grown in air or in presence of oxidizing atmospheres at temperatures up to 200 deg C. The substrate was pure iron with different superficial treatments. It was observed that these oxides reduce up to three magnitudes orders, the hydrogen stationary flux through membranes of usual thickness in comparison with iron membranes free of oxide. (Author)
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Efficacy of a biobehavioral intervention for hot flashes: a randomized controlled pilot study.
Barton, Debra L; Schroeder, Kelliann C Fee; Banerjee, Tanima; Wolf, Sherry; Keith, Timothy Z; Elkins, Gary
2017-07-01
The need for effective nonhormonal treatments for hot flash management without unwanted side effects continues. The primary aim of this pilot study was to evaluate the effect of combining a nonhormonal pharmacologic agent with a behavioral treatment for hot flash reduction. Seventy-one postmenopausal women were randomized to one of four groups: venlafaxine 75 mg + hypnosis (VH) versus venlafaxine 75 mg + sham hypnosis (VSH) versus a placebo pill + hypnosis (PH) versus placebo pill + sham hypnosis (PSH). Women recorded hot flash severity and frequency in a daily diary, in real time. The intrapatient difference in hot flash score (frequency × severity) at 8 weeks was analyzed using a General Estimating Equation model, using VSH as the referent arm, controlling for baseline hot flashes. The active arms including PH or VH were not statistically significantly different than VSH (P = 0.34, P = 0.05, respectively). Women in each active arm reported hot flash reductions of about 50%, with the PSH group reporting a 25% reduction. Women receiving the PSH reported statistically significantly smaller reductions in hot flash score than women in the referent VSH arm (P = 0.001). There were no significant negative side effects during the course of the study. Hypnosis alone reduced hot flashes equal to venlafaxine alone, but the combination of hypnosis and venlafaxine did not reduce hot flashes more than either treatment alone. More research is needed to clarify whether combining hypnosis with a different antidepressant would provide synergistic benefits.
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Small, M.
1981-04-01
In the search for a pure, available iron source, steelmakers are focusing their attention on Directly Reduced Iron (DRI). This material is produced by the reaction of a low gangue iron ore with a hydrocarbonaceous substance. Commercially, DRI is generated in four different reactors: shaft (moving-bed), rotary kiln, fluidized bed, and retort (fixed-bed). Annual worldwide production capacity approaches 33 million metric tons. Detailed assessments have been made of the uses of DRI, especially as a substitute for scrap in electric furnace (EF) steelmaking. DRI is generally of a quality superior to current grades of scrap, with steels produced more efficiently in the EF and containing lower levels of impurities. However, present economics favor EF steel production with scrap. But this situation could change within this decade because of a developing scarcity of good quality scrap.
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Higher iron bioavailability of a human-like collagen iron complex.
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.
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Laboratory procedures used in the hot corrosion project
International Nuclear Information System (INIS)
Jeys, T.R.
1980-01-01
The objective of the Hot Corrosion Project in the LLNL Metals and Ceramics Division is to study the physical and chemical mechanisms of corrosion of nickel, iron, and some of their alloys when these metals are subjected to oxidizing or sulfidizing environments at temperatures between 850 and 950 0 C. To obtain meaningful data in this study, we must rigidly control many parameters. Parameters are discussed and the methods chosen to control them in this laboratory. Some of the mechanics and manipulative procedures that are specifically related to data access and repeatability are covered. The method of recording and processing the data from each experiment using an LS-11 minicomputer are described. The analytical procedures used to evaluate the specimens after the corrosion tests are enumerated and discussed
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Directory of Open Access Journals (Sweden)
Morin Guillaume
2007-11-01
Full Text Available Abstract High levels of arsenic in groundwater and drinking water are a major health problem. Although the processes controlling the release of As are still not well known, the reductive dissolution of As-rich Fe oxyhydroxides has so far been a favorite hypothesis. Decoupling between arsenic and iron redox transformations has been experimentally demonstrated, but not quantitatively interpreted. Here, we report on incubation batch experiments run with As(V sorbed on, or co-precipitated with, 2-line ferrihydrite. The biotic and abiotic processes of As release were investigated by using wet chemistry, X-ray diffraction, X-ray absorption and genomic techniques. The incubation experiments were carried out with a phosphate-rich growth medium and a community of Fe(III-reducing bacteria under strict anoxic conditions for two months. During the first month, the release of Fe(II in the aqueous phase amounted to only 3% to 10% of the total initial solid Fe concentration, whilst the total aqueous As remained almost constant after an initial exchange with phosphate ions. During the second month, the aqueous Fe(II concentration remained constant, or even decreased, whereas the total quantity of As released to the solution accounted for 14% to 45% of the total initial solid As concentration. At the end of the incubation, the aqueous-phase arsenic was present predominately as As(III whilst X-ray absorption spectroscopy indicated that more than 70% of the solid-phase arsenic was present as As(V. X-ray diffraction revealed vivianite Fe(II3(PO42.8H2O in some of the experiments. A biogeochemical model was then developed to simulate these aqueous- and solid-phase results. The two main conclusions drawn from the model are that (1 As(V is not reduced during the first incubation month with high Eh values, but rather re-adsorbed onto the ferrihydrite surface, and this state remains until arsenic reduction is energetically more favorable than iron reduction, and (2 the
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Iron Oxide Nanoparticles Employed as Seeds for the Induction of Microcrystalline Diamond Synthesis
Directory of Open Access Journals (Sweden)
Resto Oscar
2008-01-01
Full Text Available AbstractIron nanoparticles were employed to induce the synthesis of diamond on molybdenum, silicon, and quartz substrates. Diamond films were grown using conventional conditions for diamond synthesis by hot filament chemical vapor deposition, except that dispersed iron oxide nanoparticles replaced the seeding. X-ray diffraction, visible, and ultraviolet Raman Spectroscopy, energy-filtered transmission electron microscopy , electron energy-loss spectroscopy, and X-ray photoelectron spectroscopy (XPS were employed to study the carbon bonding nature of the films and to analyze the carbon clustering around the seed nanoparticles leading to diamond synthesis. The results indicate that iron oxide nanoparticles lose the O atoms, becoming thus active C traps that induce the formation of a dense region of trigonally and tetrahedrally bonded carbon around them with the ensuing precipitation of diamond-type bonds that develop into microcrystalline diamond films under chemical vapor deposition conditions. This approach to diamond induction can be combined with dip pen nanolithography for the selective deposition of diamond and diamond patterning while avoiding surface damage associated to diamond-seeding methods.
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Iron deficiency and anemia in heart failure.
Çavuşoğlu, Yüksel; Altay, Hakan; Çetiner, Mustafa; Güvenç, Tolga Sinan; Temizhan, Ahmet; Ural, Dilek; Yeşilbursa, Dilek; Yıldırım, Nesligül; Yılmaz, Mehmet Birhan
2017-03-01
Heart failure is an important community health problem. Prevalence and incidence of heart failure have continued to rise over the years. Despite recent advances in heart failure therapy, prognosis is still poor, rehospitalization rate is very high, and quality of life is worse. Co-morbidities in heart failure have negative impact on clinical course of the disease, further impair prognosis, and add difficulties to treatment of clinical picture. Therefore, successful management of co-morbidities is strongly recommended in addition to conventional therapy for heart failure. One of the most common co-morbidities in heart failure is presence of iron deficiency and anemia. Current evidence suggests that iron deficiency and anemia are more prevalent in patients with heart failure and reduced ejection fraction, as well as those with heart failure and preserved ejection fraction. Moreover, iron deficiency and anemia are referred to as independent predictors for poor prognosis in heart failure. There is strong relationship between iron deficiency or anemia and severity of clinical status of heart failure. Over the last two decades, many clinical investigations have been conducted on clinical effectiveness of treatment of iron deficiency or anemia with oral iron, intravenous iron, and erythropoietin therapies. Studies with oral iron and erythropoietin therapies did not provide any clinical benefit and, in fact, these therapies have been shown to be associated with increase in adverse clinical outcomes. However, clinical trials in patients with iron deficiency in the presence or absence of anemia have demonstrated considerable clinical benefits of intravenous iron therapy, and based on these positive outcomes, iron deficiency has become target of therapy in management of heart failure. The present report assesses current approaches to iron deficiency and anemia in heart failure in light of recent evidence.
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[Ferrous sulfate in the treatment of iron deficiency anemia: The positions continue].
Dvoretsky, L I
The paper discusses treatment strategy and tactics for iron deficiency anemia. It gives data on the comparative efficacy of different iron sulfate drugs, their bioavailability, effects on peroxidation processes, and side effects. The paper also considers the clinical significance of a dosage form of iron-containing drugs with a sustained iron release, as well as ways to reduce the frequency and magnitude of side effects when ferrous sulfate is used.
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Marin, G H; Mestorino, N; Errecalde, J; Huber, B; Uriarte, A; Orchuela, J
2012-02-22
Because the characteristics of all body fluids depends on patient's health status, is it possible that disadvantaged and socially vulnerable mothers may have lower amounts of iron in their breast milk, and that their babies receive lower content of the mineral for their normal growth and development. Assuring a preventive treatment of the mother might solve this problem. To demonstrate breast milk iron content from disadvantaged mothers and impact of personalized iron supplementation program. cross-sectional study. Breast milk samples were obtained for ferritin analysis. Health's services usually provides free folic acid and iron treatment however, treatment compliance is low. Patients were random in two groups: "A: Controls" that had free iron tablets available from Health Centre; and "B: Intervention" group where patients accepted to be periodically contacted at home by health's team for personalized iron dispensation. 360 patients were included. Profilaxis and treatment compliance were 100% and 97,6% for B group while for "Control" one was 63% and 34%(p0.0001). Higher breast milk iron levels were detected in Intervention's mothers compared with control's patients (p0.007). Personalized iron prophylaxis and treatment increased breast milk iron levels. Public health policy must ensure iron dispensation for each underserved mother in order to reduce children problems associate to iron deficiency during the first year of their life.
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Stabilizing effects of hot electrons on low frequency plasma drift waves
International Nuclear Information System (INIS)
Huang Chaosong; Qiu Lijian; Ren Zhaoxing
1988-01-01
The MHD equation is used to study the stabilization of low frequency drift waves driven by density gradient of plasma in a hot electron plasma. The dispersion relation is derived, and the stabilizing effects of hot electrons are discussed. The physical mechanism for hot electron stabilization of the low frequency plasma perturbations is charge uncovering due to the hot electron component, which depends only on α, the ratio of N h /N i , but not on the value of β h . The hot electrons can reduce the growth rate of the interchange mode and drift wave driven by the plasma, and suppress the enomalous plasma transport caused by the drift wave. Without including the effectof β h , the stabilization of the interchange mode requires α≅2%, and the stabilization of the drift wave requires α≅40%. The theoretical analyses predict that the drift wave is the most dangerous low frequency instability in the hot electron plasma
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Petry, Nicolai; Rohner, Fabian; Gahutu, Jean Bosco; Campion, Bruno; Boy, Erick; Tugirimana, Pierrot L; Zimmerman, Michael Bruce; Zwahlen, Christian; Wirth, James P; Moretti, Diego
2016-05-01
Phytic acid (PA) is a major inhibitor of iron bioavailability from beans, and high PA concentrations might limit the positive effect of biofortified beans (BBs) on iron status. Low-phytic acid (lpa) bean varieties could increase iron bioavailability. We set out to test whether lpa beans provide more bioavailable iron than a BB variety when served as part of a composite meal in a bean-consuming population with low iron status. Dietary iron absorption from lpa, iron-biofortified, and control beans (CBs) (regular iron and PA concentrations) was compared in 25 nonpregnant young women with low iron status with the use of a multiple-meal crossover design. Iron absorption was measured with stable iron isotopes. PA concentration in lpa beans was ∼10% of BBs and CBs, and iron concentration in BBs was ∼2- and 1.5-fold compared with CBs and lpa beans, respectively. Fractional iron absorption from lpa beans [8.6% (95% CI: 4.8%, 15.5%)], BBs [7.3% (95% CI: 4.0%, 13.4%)], and CBs [8.0% (95% CI: 4.4%, 14.6%)] did not significantly differ. The total amount of iron absorbed from lpa beans and BBs was 421 μg (95% CI: 234, 756 μg) and 431 μg (95% CI: 237, 786 μg), respectively, and did not significantly differ, but was >50% higher (P beans were hard to cook, and their consumption caused transient adverse digestive side effects in ∼95% of participants. Gel electrophoresis analysis showed phytohemagglutinin L (PHA-L) residues in cooked lpa beans. BBs and lpa beans provided more bioavailable iron than control beans and could reduce dietary iron deficiency. Digestive side effects of lpa beans were likely caused by PHA-L, but it is unclear to what extent the associated digestive problems reduced iron bioavailability. This trial was registered at clinicaltrials.gov as NCT02215278. © 2016 American Society for Nutrition.
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Geerligs, P. D. Prinsen; Brabin, B. J.; Omari, A. A. A.
2003-01-01
Objective To complete a systematic review of the effect of preparing food cooked in iron pots on haemoglobin concentrations and to assess compliance with pot use. Design and Search strategy We searched The Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effectiveness,
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Solid adsorbents for removal of hydrogen sulphide from hot gas
Energy Technology Data Exchange (ETDEWEB)
Furimsky, E.; Yumura, Motoo
1986-04-01
A wide range of solids have been tested as potential adsorbents for H/sub 2/S removal from hot gas. These solids can be divided into two main groups, i.e., the adsorbents containing alkaline earth metals and those containing transition metals. Among the former, calcium oxide and naturally occurring materials such as limestone, dolomite and calcium silicate have attracted a great deal of attention. The adsorbents of the second group include iron oxide alone or in combination with some supports, zinc oxide, zinc ferrite and manganese oxide. The materials containing both the alkaline earth metals and transition metals, e.g., manganese nodules, fly ash and the reject from the aluminium industry (red mud) have been evaluated as well.
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Inhibition of turbulence in inertial-confinement-fusion hot spots by viscous dissipation.
Weber, C R; Clark, D S; Cook, A W; Busby, L E; Robey, H F
2014-05-01
Achieving ignition in inertial confinement fusion (ICF) requires the formation of a high-temperature (>10 keV) central hot spot. Turbulence has been suggested as a mechanism for degrading the hot-spot conditions by altering transport properties, introducing colder, mixed material, or reducing the conversion of radially directed kinetic energy to hot-spot heating. We show, however, that the hot spot is very viscous, and the assumption of turbulent conditions in the hot spot is incorrect. This work presents the first high-resolution, three-dimensional simulations of National Ignition Facility (NIF) implosion experiments using detailed knowledge of implosion dynamics and instability seeds and including an accurate model of physical viscosity. We find that when viscous effects are neglected, the hot spot can exhibit a turbulent kinetic energy cascade. Viscous effects, however, are significant and strongly damp small-scale velocity structures, with a hot-spot Reynolds number in the range of only 10-100.
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Gu, Lin; Li, Binglian; Wen, Haifeng; Zhang, Xin; Wang, Liang; Ye, Jianfeng
2018-06-01
The hydrothermal carbonization (HTC) was performed on Metasequoia Leaves (ML) in the presence of iron sludge, both of which were generated as solid residuals. The relations between sludge, char's properties and operating conditions were systemically investigated. Iron sludge primarily catalyzed the efficient formation of char with higher heating value (HHV) becoming 1.15-1.65 times of ML (18.21 MJ/kg) and was meanwhile reduced to magnetite. The hydrated Fe ions in octahedron crystals acted as nucleophiles facilitating the dehydration and decarboxylation reactions. The increased HHV is found strong temperature dependent while prolonging the residence time is more preferable for low organic acids generation. Thermogravimetric analysis confirmed the iron sludge enhanced conversion of volatile to fixed carbon. The as-prepared solid char showed better stability after catalytic HTC treatment, having ignition temperature increased from 253 to 426 °C as compared to the char prepared without iron sludge addition. Copyright © 2018 Elsevier Ltd. All rights reserved.
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Energy Technology Data Exchange (ETDEWEB)
Kashparov, V A; Ivanov, Yu A; Prister, B S; Zvarich, S I; Protsak, V P; Khomutinin, Yu V; Polyakov, V D; Gudkov, A N; Kurepin, A D; Pazukhin, Eh M [Yinstitut Syil` s` kogospodars` koyi Radyiologyiyi, Kyiv (Ukraine); [Moskovskij Inzhenerno-Fizicheskij Inst., Moscow (Russian Federation)
1994-12-31
Dispersal composition of fuel << hot >> particles formed after oxidation of real Chernobyl nuclear fuel in the air for 3-21 hours at 673-1173 K was obtained. Mechanism of ruthenium particles formation during the accident (with dispersion of nuclear fuel) as a result of ruthenium oxidation, its sublimation, condensation and restoration on materials, presented by the elements of iron group was modelled. Dynamics of relative release of fission products, as well as of transuranium and transplutonium elements from real and modeled << hot >> particles at their high temperature incineration (1273-2273 K) in the inert media was measured.
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Mechanism of iron uptake by the pathogenic yeast, Candida albicans
International Nuclear Information System (INIS)
Ismail, A.
1986-01-01
C. albicans requires iron for growth and phenotypic development. When deprived of iron, mycelium and bud formation was suppressed. Survival of the organism was also reduced under iron-limiting conditions. The combination of elevated temperature and iron-deprivation further reduced phenotypic development and survival of the yeast. The combination of elevated temperature and iron starvation resulted in a decrease in both the growth rate and siderophore production. However, with time, the cells were able to show partial recovery in the growth rate which occurred concomitantly with an increase in siderophore production. In order for siderophores to be utilized, ferri-siderophore receptors must be produced. The receptor was shown to be located in the plasma membrane of the yeast. Scatchard analysis of the binding of ferri-siderophores to plasma membrane receptors showed an increase in receptor affinity and number of binding sites in iron-starved cells when compared to control cells. Autoradiograms of the 58 Fe-siderophore-protein complex following SDS-PAGE separation of candidal proteins revealed the presence of a ferri-siderophore receptor of approximately 10,000 daltons. C. albicans strains which lacked the ability to synthesize phenolate siderophore maintained a phenolate receptor and bound candidal phenolate siderophore better than non-candidal phenolate siderophores
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International Nuclear Information System (INIS)
Marwat, I.U.; Hassan, K.A.; Javed, T.; Chishti, A.L.
2013-01-01
Iron deficiency of anemia (IDA) is defined as reduced number of red blood cells, and / or reduced concentration hemoglobin (Hb) due to deficiency of iron. Treatment involves dietary modifications and inorganic iron salt supplements like ferrous sulfate (FS) or Iron polymaltose complex (IPC). The decision to select either drug rests on therapeutic efficacy, untoward side effects; cost of complete course, patient's compliance and discretion of physician. Both drugs can be prescribed in oral form. This study aimed at comparing the efficacy of two iron preparations (ferrous sulphate and iron polymaltose complex salts) in childhood iron deficiency anemia. Objective: To compare the efficacy of Ferrous Sulphate and Iron Polymaltose Complex salts in the treatment of childhood Iron Deficiency Anemia. Methodology: This randomized controlled trial was conducted at Department of Pediatric Medicine Unit-II Mayo Hospital, Lahore, for a period of 6 months. One hundred and fifty children aged 6 months to 5 years suffering from iron deficiency anemia were selected and randomly divided into two groups of 75 each (Group A and B prescribed FS and IPC respectively). Results were analyzed in terms of rise in Hb from the baseline after three months. Increase in Hb level 2 gm/dl after three months of treatment was considered as effective. Results were analyzed by SPSS version 17. Efficacy of both the drugs, was compared by chi square test. P value 0.05 was accepted as significant. Results: There were 34 cases (22.7%) in 6-12 months age, 77 cases (51.3%) between 1-3 years age and 39 cases (26%) between 3-5 years age. The number of male and female children was 82 (54.7%) and 68 (45.3%) respectively. The baseline hemoglobin of all study cases was 6.64+-1.08 gm/dl (6.59+-1.13 gm/dl in Group A and 6.69+-1.04 gm/dl in Group B). At completion of therapy, the mean hemoglobin of all study cases was 9.15+-1.21 gm/dl (9.20+9-1.17 gm/dl in Group A and 9.11+-1.25 gm/dl in Group B). The difference
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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 ...
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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.
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Heart failure in patients with kidney disease and iron deficiency: The role of iron therapy
Directory of Open Access Journals (Sweden)
Aleix Cases Amenós
2017-11-01
Full Text Available Chronic kidney disease and anaemia are common in heart failure (HF and are associated with a worse prognosis in these patients. Iron deficiency is also common in patients with HF and increases the risk of morbidity and mortality, regardless of the presence or absence of anaemia. While the treatment of anaemia with erythropoiesis-stimulating agents in patients with HF have failed to show a benefit in terms of morbidity and mortality, treatment with IV iron in patients with HF and reduced ejection fraction and iron deficiency is associated with clinical improvement. In a post hoc analysis of a clinical trial, iron therapy improved kidney function in patients with HF and iron deficiency. In fact, the European Society of Cardiology's recent clinical guidelines on HF suggest that in symptomatic patients with reduced ejection fraction and iron deficiency, treatment with IV ferric carboxymaltose should be considered to improve symptoms, the ability to exercise and quality of life. Iron plays a key role in oxygen storage (myoglobin and in energy metabolism, and there are pathophysiological bases that explain the beneficial effect of IV iron therapy in patients with HF. All these aspects are reviewed in this article. Resumen: La enfermedad renal crónica y la anemia son frecuentes en la insuficiencia cardíaca (IC y su presencia se asocia con un peor pronóstico en estos pacientes. La ferropenia es frecuente en pacientes con IC y aumenta el riesgo de morbimortalidad, independientemente de la presencia o no de anemia. Mientras el tratamiento de la anemia con agentes estimuladores de la eritropoyesis en pacientes con IC no ha demostrado un beneficio sobre la morbimortalidad, el tratamiento con hierro intravenoso (iv en pacientes con IC y fracción de eyección disminuida y déficit de hierro se asocia con una mejoría clínica. Además, en un análisis post hoc de un ensayo clínico, la ferroterapia mejoró la función renal en pacientes con IC y
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Reducing As availability in calcareous soils using nanoscale zero valent iron.
Azari, Prisa; Bostani, Abdol Amir
2017-09-01
Different methods, including the use of nanoscale zero-valent iron (NZVI), have been used to treat arsenic (As)-contaminated environments, with much less data on the use of NZVI in arsenic-calcareous-polluted soils. Accordingly, two different experiments were conducted to investigate the effects of NZVI on the removal of As from three different calcareous-polluted soils. In the first experiment, the effects of soil type (differing in the rate of clay particles and organic carbon including S1 (8.0 and 0.05%), S2 (20 and 0.2%), and S3 (20.5 and 0.8%)) and NZVI concentration (0, 50, and 100 g kg -1 of dry soil) on the removal of As extractable with distilled water were evaluated using a factorial design with three replicates. In the second experiment, the NZVI concentrations were reduced to 0, 2.5, 5.0, and 25 g kg -1 , and the NZVI contact time (0.5, 48, 96, 192, 384, and 768 h) was also tested. The analysis of variance in both experiments indicated the significant effects (P soils, with increasing NZVI concentration and contact time, the concentration of available As in the solution phase significantly decreased (P = 0.01). S3, due to a higher rate of organic matter, was less responsive to the NZVI treatments than the other soils. The effectiveness of the nanoremediation method, tested in this research work, on the stabilization of As in calcareous soils, is verified.
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Iron addiction: a novel therapeutic target in ovarian cancer
International Nuclear Information System (INIS)
Basuli, D.
2017-01-01
Ovarian cancer is a lethal malignancy that has not seen a major therapeutic advance in over 30 years. We demonstrate that ovarian cancer exhibits a targetable alteration in iron metabolism. Ferroportin (FPN), the iron efflux pump, is decreased, and transferrin receptor (TFR1), the iron importer, is increased in tumor tissue from patients with high grade but not low grade serous ovarian cancer. A similar profile of decreased FPN and increased TFR1 is observed in a genetic model of ovarian cancer tumor-initiating cells (TICs). The net result of these changes is an accumulation of excess intracellular iron and an augmented dependence on iron for proliferation. A forced reduction in intracellular iron reduces the proliferation of ovarian cancer TICs in vitro, and inhibits both tumor growth and intraperitoneal dissemination of tumor cells in vivo. Some mechanistic studies demonstrate that iron increases metastatic spread by facilitating invasion through expression of matrix metalloproteases and synthesis of interleukin 6 (IL-6). Here, we show that the iron dependence of ovarian cancer TICs renders them exquisitely sensitive in vivo to agents that induce iron-dependent cell death (ferroptosis) as well as iron chelators, and thus creates a metabolic vulnerability that can be exploited therapeutically.
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Dietary iron intake, iron status, and gestational diabetes.
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.
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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...
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Influence of the Moisture Content on the Flowability of Fine-Grained Iron Ore Concentrate
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...
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Control of cast iron and casts manufacturing by Inmold method
Directory of Open Access Journals (Sweden)
S. Pietrowski
2009-07-01
Full Text Available In this paper the usability of cast iron spheroidizing process in mould control by ATD method as well as by ultrasonic method were presented. Structure of instrumentation needed for control form performance of cast iron spheroidizing by Inmold method was illustrated. Author, pointed out that amount of magnesium master alloy should obtain 0,8 ÷ 1,0% of mass in form at all. Such quantity of preliminary alloy assure of obtain of nodular graphite in cast iron. In consequence of this, is reduce the cast iron liquidus temperature and decrease of recalescence temperature of graphite-eutectic crystallization in compare with initial cast iron. Control of casts can be carried out by ultrasonic method. In plain cast iron, ferritic-pearlitic microstructure is obtaining. Additives of 1,5% Cu ensure pearlitic structure.
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The Relation Between Alloy Chemistry and Hot-Cracking
Nunes, A. C., Jr.; Talia, J. E.
2000-01-01
Hot cracking is a problem in welding 2195 aluminum-lithium alloy. Weld wire additives seem to reduce the problem. This study proposes a model intended to clarify the way alloying elements affect hot-cracking. The brittle temperature range of an alloy extends wherever the tensile stress required to move the meniscus of the liquid film at the grain/dendrite boundaries is less than the bulks flow stress Sigma(sub B) of the grains: 2gamma/delta alloys outgas.) If the above condition is not met, the grains deform under stress and the liquid film remains in place. Curves of 2gamma/delta and sigma(sub B) vs. temperature in the range just below the melting temperature determine the hot cracking susceptibility of an alloy. Both are zero at onset of solidification. sigma(sub B) rises as the thermal activation of the slip mechanism is reduced. 2gamma/delta rises as the film thickness delta which can be estimated from the Scheil equation, drops. But, given an embrittled alloy, whether the alloy actually cracks is determined by the strain imposed upon it in the embrittled condition. A critical strain is estimated, Epsilon(sub C) on the order of Epsilon(sub C) is approximately delta/l where L = grain size and where the the volume increment due to the strain, concentrated at the liquid film, is on the order of the liquid film volume. In the early 80's an empirical critical strain cracking envelope Epsilon(sub C)(T) was incorporated into a damage criterion to estimate the effect of welding parameters on the formation of microfissures in a superalloy with good results. These concepts, liquid film decoherence vs. grain bulk deformation and critical strain, form the key elements of a quantitative theory of hot-cracking applicable for assessing the effect of alloying elements on hot-cracking during welding.
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HOT STARS WITH HOT JUPITERS HAVE HIGH OBLIQUITIES
International Nuclear Information System (INIS)
Winn, Joshua N.; Albrecht, Simon; Fabrycky, Daniel; Johnson, John Asher
2010-01-01
We show that stars with transiting planets for which the stellar obliquity is large are preferentially hot (T eff > 6250 K). This could explain why small obliquities were observed in the earliest measurements, which focused on relatively cool stars drawn from Doppler surveys, as opposed to hotter stars that emerged more recently from transit surveys. The observed trend could be due to differences in planet formation and migration around stars of varying mass. Alternatively, we speculate that hot-Jupiter systems begin with a wide range of obliquities, but the photospheres of cool stars realign with the orbits due to tidal dissipation in their convective zones, while hot stars cannot realign because of their thinner convective zones. This in turn would suggest that hot Jupiters originate from few-body gravitational dynamics and that disk migration plays at most a supporting role.
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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....
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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.
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Zhu, Le; Glahn, Raymond P; Nelson, Deanna; Miller, Dennis D
2009-06-10
Iron bioavailability from supplements and fortificants varies depending upon the form of the iron and the presence or absence of iron absorption enhancers and inhibitors. Our objectives were to compare the effects of pH and selected enhancers and inhibitors and food matrices on the bioavailability of iron in soluble ferric pyrophosphate (SFP) to other iron fortificants using a Caco-2 cell culture model with or without the combination of in vitro digestion. Ferritin formation was the highest in cells treated with SFP compared to those treated with other iron compounds or chelates. Exposure to pH 2 followed by adjustment to pH 7 markedly decreased FeSO(4) bioavailability but had a smaller effect on bioavailabilities from SFP and sodium iron(III) ethylenediaminetetraacetate (NaFeEDTA), suggesting that chelating agents minimize the effects of pH on iron bioavailability. Adding ascorbic acid (AA) and cysteine to SFP in a 20:1 molar ratio increased ferritin formation by 3- and 2-fold, respectively, whereas adding citrate had no significant effect on the bioavailability of SFP. Adding phytic acid (10:1) and tannic acid (1:1) to iron decreased iron bioavailability from SFP by 91 and 99%, respectively. The addition of zinc had a marked inhibitory effect on iron bioavailability. Calcium and magnesium also inhibited iron bioavailability but to a lesser extent. Incorporating SFP in rice greatly reduced iron bioavailability from SFP, but this effect can be partially reversed with the addition of AA. SFP and FeSO(4) were taken up similarly when added to nonfat dry milk. Our results suggest that dietary factors known to enhance and inhibit iron bioavailability from various iron sources affect iron bioavailability from SFP in similar directions. However, the magnitude of the effects of iron absorption inhibitors on SFP iron appears to be smaller than on iron salts, such as FeSO(4) and FeCl(3). This supports the hypothesis that SFP is a promising iron source for food fortification
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Directory of Open Access Journals (Sweden)
Monika Jain
2014-12-01
Full Text Available Anaemia in school aged girls is an important but neglected issue. Since iron supplementation programmes have had little reported success in reducing anaemia, interest is turning to food based approaches that have higher potential for achieving far reaching benefits. The purpose of the study was to observe sustainability of the effect of iron and food supplementation on haemoglobin (Hb, intelligence quotient (IQ and growth of the subjects. At baseline, estimation of haemoglobin (Hb, red cell indices, serum iron, total iron binding capacity, serum transferrin saturation and serum ferritin was done. IQ, weight and height were measured using standard procedures. Anaemic subjectswere divided into three groups, viz., (i twice weekly supplementation of iron folic acid syrup (53 mg iron/week; (ii daily supplementation of 4 niger seed and defatted soyaflour biscuits plus 2 lemons (45 mg iron/week and (iii control. Non anaemic group(NAC was not intervened. Endline data was collected after 120 days. Follow up for Hb, IQ, weight and height was done 4 months after cessation of supplementation. The prevalence of anaemia was 77% in the study population; 46% subjects had mild anaemia and 32% had moderate anaemia. Iron status was lower in anaemic subjects (p<0.001.Iron supplementation was more effective in raising Hb and building iron stores than iron rich food supplementation. Iron supplementation improved IQ but did not bring about catch up of anaemics to non anaemics. Iron rich food supplementation was better than medicinal iron in promoting growth in anaemic girls. The impact of iron rich food supplementation on Hb, IQ and growth sustained for 4 months while that of medicinal iron did not. Effects of food supplementation are sustainable for 4 months, therefore, this strategy holds more potential to control anaemia, in school aged girls.
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Hot corrosion of low cobalt alloys
Stearns, C. A.
1982-01-01
The hot corrosion attack susceptibility of various alloys as a function of strategic materials content are investigated. Preliminary results were obtained for two commercial alloys, UDIMET 700 and Mar-M 247, that were modified by varying the cobalt content. For both alloys the cobalt content was reduced in steps to zero. Nickel content was increased accordingly to make up for the reduced cobalt but all other constituents were held constant. Wedge bar test samples were produced by casting. The hot corrosion test consisted of cyclically exposing samples to the high velocity flow of combustion products from an air-fuel burner fueled with jet A-1 and seeded with a sodium chloride aqueous solution. The flow velocity was Mach 0.5 and the sodium level was maintained at 0.5 ppm in terms of fuel plus air. The test cycle consisted of holding the test samples at 900 C for 1 hour followed by 3 minutes in which the sample could cool to room temperature in an ambient temperature air stream.
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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....
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Vacuum hot pressing of titanium-alloy powders
International Nuclear Information System (INIS)
Malik, R.K.
1975-01-01
Full or nearly full dense products of wrought-metal properties have been obtained by vacuum hot pressing (VHP) of several prealloyed Ti--6Al--4V powders including hydride, hydride/dehydride, and rotating electrode process (REP) spherical powder. The properties of billets VHP from Ti--6Al--4V hydride powder and from hydride/dehydride powders have been shown to be equivalent. The REP spherical powder billets processed by VHP or by hot isostatic pressing (HIP) resulted in equivalent tensile properties. The potential of VHP for fabrication of near net aircraft parts such as complex fittings and engine disks offers considerable cost savings due to reduced material and machining requirements
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Clean recycle and utilization of hazardous iron-bearing waste in iron ore sintering process.
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.
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The Effect Of Local Coal And Smelting Sponge Iron On Iron Content Of Pig Iron
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.
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Iron single crystal growth from a lithium-rich melt
Fix, M.; Schumann, H.; Jantz, S. G.; Breitner, F. A.; Leineweber, A.; Jesche, A.
2018-03-01
α -Fe single crystals of rhombic dodecahedral habit were grown from a Li84N12Fe∼3 melt. Crystals of several millimeter along a side form at temperatures around T ≈ 800 ° C. Upon further cooling the growth competes with the formation of Fe-doped Li3N. The b.c.c. structure and good sample quality of α -Fe single crystals were confirmed by X-ray and electron diffraction as well as magnetization measurements and chemical analysis. A nitrogen concentration of 90 ppm was detected by means of carrier gas hot extraction. Scanning electron microscopy did not reveal any sign of iron nitride precipitates.
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Iron deficiency alters megakaryopoiesis and platelet phenotype independent of thrombopoietin.
Evstatiev, Rayko; Bukaty, Adam; Jimenez, Kristine; Kulnigg-Dabsch, Stefanie; Surman, Lidia; Schmid, Werner; Eferl, Robert; Lippert, Kathrin; Scheiber-Mojdehkar, Barbara; Kvasnicka, Hans Michael; Khare, Vineeta; Gasche, Christoph
2014-05-01
Iron deficiency is a common cause of reactive thrombocytosis, however, the exact pathways have not been revealed. Here we aimed to study the mechanisms behind iron deficiency-induced thrombocytosis. Within few weeks, iron-depleted diet caused iron deficiency in young Sprague-Dawley rats, as reflected by a drop in hemoglobin, mean corpuscular volume, hepatic iron content and hepcidin mRNA in the liver. Thrombocytosis established in parallel. Moreover, platelets produced in iron deficient animals displayed a higher mean platelet volume and increased aggregation. Bone marrow studies revealed subtle alterations that are suggestive of expansion of megakaryocyte progenitors, an increase in megakaryocyte ploidy and accelerated megakaryocyte differentiation. Iron deficiency did not alter the production of hematopoietic growth factors such as thrombopoietin, interleukin 6 or interleukin 11. Megakaryocytic cell lines grown in iron-depleted conditions exhibited reduced proliferation but increased ploidy and cell size. Our data suggest that iron deficiency increases megakaryopoietic differentiation and alters platelet phenotype without changes in megakaryocyte growth factors, specifically TPO. Iron deficiency-induced thrombocytosis may have evolved to maintain or increase the coagulation capacity in conditions with chronic bleeding. Copyright © 2014 Wiley Periodicals, Inc.
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Iron/iron oxide core-shell nanoclusters for biomedical applications
International Nuclear Information System (INIS)
Qiang You; Antony, Jiji; Sharma, Amit; Nutting, Joseph; Sikes, Daniel; Meyer, Daniel
2006-01-01
Biocompatible magnetic nanoparticles have been found promising in several biomedical applications for tagging, imaging, sensing and separation in recent years. Most magnetic particles or beads currently used in biomedical applications are based on ferromagnetic iron oxides with very low specific magnetic moments of about 20-30 emu/g. Here we report a new approach to synthesize monodispersed core-shell nanostructured clusters with high specific magnetic moments above 200 emu/g. Iron nanoclusters with monodispersive size of diameters from 2 nm to 100 nm are produced by our newly developed nanocluster source and go to a deposition chamber, where a chemical reaction starts, and the nanoclusters are coated with iron oxides. HRTEM Images show the coatings are very uniform and stable. The core-shell nanoclusters are superparamagnetic at room temperature for sizes less than 15 nm, and then become ferromagnetic when the cluster size increases. The specific magnetic moment of core-shell nanoclusters is size dependent, and increases rapidly from about 80 emu/g at the cluster size of around 3 nm to over 200 emu/g up to the size of 100 nm. The use of high magnetic moment nanoclusters for biomedical applications could dramatically enhance the contrast for MRI, reduce the concentration of magnetic particle needs for cell separation, or make drug delivery possible with much lower magnetic field gradients
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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...
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46 CFR 56.60-10 - Cast iron and malleable iron.
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...
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International Nuclear Information System (INIS)
Bengtsson, Bernt; Chen, Jiaxin; Andersson, Petter
2014-01-01
For the last 10 years of service of Ringhals PWR unit 4, operating with Alloy-600MA steam generator tubing materials and a coolant pH of 7.2 (a)300°C, the cold water channel heads experienced continuous dose rate elevation. In the hot parts, however, it remained stable. Similar observations were made in Ringhals unit 2 and 3 after SGR to Alloy 690 and sometimes in other PWRs operated at similarly 'low' pH-regime. Following the introduction of elevated pH regime at Ringhals PWRs the cold side dose rates dropped to the similar levels as on the hot side. The phenomena are analysed in this paper from three different aspects: (1) the general plant observations in dose rate development under different coolant pH regimes; (2) the concentrations of dissolved and soluble iron species at the low and high coolant pH values and (3) the microstructures of the oxide films formed on the cold and hot sides of a steam generator tube pulled from a retired steam generator. Based on the analyses a hypothesis is elaborated that the formation of a thin but highly radioactive layer of iron-rich oxide deposit on the cold side may be responsible for the dose rate elevation and that its formation may be harder at the elevated pH regime. (author)
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The influence of prior ageing on microstructure, tensile properties and hot hardness of alloy 800HT
International Nuclear Information System (INIS)
El-Magd, E.
1996-01-01
For high temperature applications especially in the construction of equipment, carbide strengthened steels are widely used because of their good mechanical properties and relatively low cost. These materials undergo microstructural changes under such service conditions which contribute greatly to the strength properties and thus play an important role in equipment design considerations. The influence of a prior thermal ageing on the tensile strength values and the hot hardness of the austenitic iron base alloy, Alloy 800HT, is examined in this work. It was therefore necessary to carry out tensile and hot hardness tests with the solution treated and overaged material at ranges between room temperature and 900 . The microstructural changes are investigated using lightmicroscopy, SEM and TEM. The changes of the material properties with thermal pretreatment conditions is studied and discussed in the context of the determined microstructural development. (orig.) [de
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Iron Mineralogy and Speciation in Clay-Sized Fractions of Chinese Desert Sediments
Lu, Wanyi; Zhao, Wancang; Balsam, William; Lu, Huayu; Liu, Pan; Lu, Zunli; Ji, Junfeng
2017-12-01
Iron released from Asian desert dust may be an important source of bioavailable iron for the North Pacific Ocean and thereby may stimulate primary productivity. However, the Fe species of the fine dusts from this source region are poorly characterized. Here we investigate iron species and mineralogy in the clay-sized fractions (iron phases (ferrihydrite and lepidocrocite) and reducible iron oxides (dominated by goethite) are 0.81 wt % and 2.39 wt %, respectively, and Fe dissolved from phyllosilicates extracted by boiling HCl (dominated by chlorite) is 3.15 wt %. Dusts originating from deserts in northwestern China, particularly the Taklimakan desert, are relatively enriched in easily reducible Fe phases, probably due to abundant Fe contained in fresh weathering products resulting from the rapid erosion associated with active uplift of mountains to the west. Data about Fe speciation and mineralogy in Asian dust sources will be useful for improving the quantification of soluble Fe supplied to the oceans, especially in dust models.
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Moretti, Diego; Schuth, Stephan; Egli, Ines; Zimmermann, Michael B.; Brouwer, Inge D.
2013-01-01
Low iron and high phytic acid content make fonio based meals a poor source of bioavailable iron. Phytic acid degradation in fonio porridge using whole grain cereals as phytase source and effect on iron bioavailability when added to iron fortified fonio meals were investigated. Grains, nuts and seeds collected in Mali markets were screened for phytic acid and phytase activity. We performed an iron absorption study in Beninese women (n = 16), using non-dephytinised fonio porridge (FFP) and dephytinised fonio porridge (FWFP; 75% fonio-25% wheat), each fortified with 57Fe or 58Fe labeled FeSO4. Iron absorption was quantified by measuring the erythrocyte incorporation of stable iron isotopes. Phytic acid varied from 0.39 (bambara nut) to 4.26 g/100 g DM (pumpkin seed), with oilseeds values higher than grains and nuts. Phytase activity ranged from 0.17±1.61 (fonio) to 2.9±1.3 phytase unit (PU) per g (whole wheat). Phytic acid was almost completely degraded in FWFP after 60 min of incubation (pH≈5.0, 50°C). Phytate∶iron molar ratios decreased from 23.7∶1 in FFP to 2.7∶1 in FWFP. Iron fortification further reduced phytate∶iron molar ratio to 1.9∶1 in FFP and 0.3∶1 in FWFP, respectively. Geometric mean (95% CI) iron absorption significantly increased from 2.6% (0.8–7.8) in FFP to 8.3% (3.8–17.9) in FWFP (Pphytase increased fractional iron absorption 3.2 times, suggesting it could be a possible strategy to decrease PA in cereal-based porridges. PMID:24124445
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Gear hot forging process robust design based on finite element method
International Nuclear Information System (INIS)
Xuewen, Chen; Won, Jung Dong
2008-01-01
During the hot forging process, the shaping property and forging quality will fluctuate because of die wear, manufacturing tolerance, dimensional variation caused by temperature and the different friction conditions, etc. In order to control this variation in performance and to optimize the process parameters, a robust design method is proposed in this paper, based on the finite element method for the hot forging process. During the robust design process, the Taguchi method is the basic robust theory. The finite element analysis is incorporated in order to simulate the hot forging process. In addition, in order to calculate the objective function value, an orthogonal design method is selected to arrange experiments and collect sample points. The ANOVA method is employed to analyze the relationships of the design parameters and design objectives and to find the best parameters. Finally, a case study for the gear hot forging process is conducted. With the objective to reduce the forging force and its variation, the robust design mathematical model is established. The optimal design parameters obtained from this study indicate that the forging force has been reduced and its variation has been controlled
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Fan, Zhengfeng; Liu, Jie
2016-10-01
We present an ion-electron non-equilibrium model, in which the hot-spot ion temperature is higher than its electron temperature so that the hot-spot nuclear reactions are enhanced while energy leaks are considerably reduced. Theoretical analysis shows that the ignition region would be significantly enlarged in the hot-spot rhoR-T space as compared with the commonly used equilibrium model. Simulations show that shocks could be utilized to create and maintain non-equilibrium conditions within the hot spot, and the hot-spot rhoR requirement is remarkably reduced for achieving self-heating. In NIF high-foot implosions, it is observed that the x-ray enhancement factors are less than unity, which is not self-consistent and is caused by assuming Te =Ti. And from this non-consistency, we could infer that ion-electron non-equilibrium exists in the high-foot implosions and the ion temperature could be 9% larger than the equilibrium temperature.
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Ferrokinetic studies in normal and iron deficiency anemic calves
International Nuclear Information System (INIS)
Moellerberg, L.; Ekman, L.; Jacobsson, S.-O.
1975-01-01
inetic studies were performed on control calves and on calves with experimentallally induced iron deficiency anemia, all 15 weeks old. The plasma iron clearance half time was about 4 times shorter in the experimental than in the control group. The low plasma iron concentration in the anemic calves was partially compensated by a more rapid plasma iron disappearance. Therefore the difference in the plasma iron turnover rate was reduced. The mean value of plasma iron renewal rate was about 3 times higher in the experimental than in the control group. The maximum uptake of injected 59 Fe into blood cells was reached 14 to 16 days after injection. The uptake of 59 Fe was about 10 % higher in the control than in the experimental group. Using the values from the ferrokinetietic study, the iron need for calves could be estimated. The requirement of iron to maintain a normal and constant Hb in a calf weighing 100 kg at a growth rate of 1 kg/daily was estimated as being 17.5 mg/day. Based on information in the literature and assuming a retention of dietary Fe of 25 %, the total daily iron need for such a calf gaining 1 kg/day would be 160-180 mg. (author)
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Alemán, Mercedes; Bou, Ricard; Tres, Alba; Polo, Javier; Codony, Rafael; Guardiola, Francesc
2016-04-01
Fortification of food products with iron is a common strategy to prevent or overcome iron deficiency. However, any form of iron is a pro-oxidant and its addition will cause off-flavours and reduce a product's shelf life. A highly bioavailable heme iron ingredient was selected to fortify a chocolate cream used to fill sandwich-type cookies. Two different strategies were assessed for avoiding the heme iron catalytic effect on lipid oxidation: ascorbyl palmitate addition and co-spray-drying of heme iron with calcium caseinate. Oxidation development and sensory acceptability were monitored in the cookies over one-year of storage at room temperature in the dark. The addition of ascorbyl palmitate provided protection against oxidation and loss of tocopherols and tocotrienols during the preparation of cookies. In general, ascorbyl palmitate, either alone or in combination with the co-spray-dried heme iron, prevented primary oxidation and hexanal formation during storage. The combination of both strategies resulted in cookies that were acceptable from a sensory point of view after 1year of storage. Copyright © 2015 Elsevier Ltd. All rights reserved.
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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.
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Moreadith, R W; Batshaw, M L; Ohnishi, T; Kerr, D; Knox, B; Jackson, D; Hruban, R; Olson, J; Reynafarje, B; Lehninger, A L
1984-09-01
We report the case of an infant with hypoglycemia, progressive lactic acidosis, an increased serum lactate/pyruvate ratio, and elevated plasma alanine, who had a moderate to profound decrease in the ability of mitochondria from four organs to oxidize pyruvate, malate plus glutamate, citrate, and other NAD+-linked respiratory substrates. The capacity to oxidize the flavin adenine dinucleotide-linked substrate, succinate, was normal. The most pronounced deficiency was in skeletal muscle, the least in kidney mitochondria. Enzymatic assays on isolated mitochondria ruled out defects in complexes II, III, and IV of the respiratory chain. Further studies showed that the defect was localized in the inner membrane mitochondrial NADH-ubiquinone oxidoreductase (complex I). When ferricyanide was used as an artificial electron acceptor, complex I activity was normal, indicating that electrons from NADH could reduce the flavin mononucleotide cofactor. However, electron paramagnetic resonance spectroscopy performed on liver submitochondrial particles showed an almost total loss of the iron-sulfur clusters characteristic of complex I, whereas normal signals were noted for other mitochondrial iron-sulfur clusters. This infant is presented as the first reported case of congenital lactic acidosis caused by a deficiency of the iron-sulfur clusters of complex I of the mitochondrial electron transport chain.
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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 ...
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Hot Corrosion of Single-Crystal NiAl-X Alloys
Nesbitt, James A.
1998-01-01
Several single-crystal NiAl-X alloys (X=Hf, Ti, Cr, Ga) underwent hot corrosion testing in a Mach 0.3 burner rig at 900 deg. C for 300 1-hr cycles. The surface morphology after testing consisted of either mounds or an inward, uniform-type of attack which preserved surface features. It was observed that the surface morphology was affected by the surface preparation treatments. Microstructurally, the hot corrosion attack initiated as pits but evolved to a rampant attack consisting of the rapid inward growth of Al2O3. Electropolishing and chemical milling produced many pits and grooves on the surface. However, the presence of pits and grooves did not appear to strongly influence the hot corrosion response. Attack on many samples was strongly localized which was attributed to compositional inhomogeneity within the samples. It was found that increasing the Ti content from 1% to 5 % degraded the hot corrosion response of these alloys. In contrast, the addition of 1-2% Cr reduced the susceptibility of these alloys to hot corrosion attack and negated the deleterious effect of the 4-5% Ti addition.
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Energy Technology Data Exchange (ETDEWEB)
Sun, Yubing [School of Environment and Chemical Engineering, North China Electric Power University, Beijing 102206 (China); Institute of Plasma Physics, Chinese Academy of Science, P.O. Box 1126, Hefei, 230031 (China); Ding, Congcong; Cheng, Wencai [Institute of Plasma Physics, Chinese Academy of Science, P.O. Box 1126, Hefei, 230031 (China); Wang, Xiangke, E-mail: xkwang@ipp.ac.cn [School of Environment and Chemical Engineering, North China Electric Power University, Beijing 102206 (China); Faculty of Engineering, King Abdulaziz University, Jeddah 21589 (Saudi Arabia)
2014-09-15
Graphical abstract: - Highlights: • Sorption and in-situ reduction of U(VI) is observed. • The composites are more effective for U(VI) removal and solidification. • The inner-sphere surface complexes are observed. - Abstract: The reduced graphene oxide-supported nanoscale zero-valent iron (nZVI/rGO) composites were synthesized by chemical deposition method and were characterized by SEM, high resolution TEM, Raman and potentiometric acid-base titrations. The characteristic results showed that the nZVI nanoparticles can be uniformly dispersed on the surface of rGO. The removal of U(VI) on nZVI/rGO composites as a function of contact time, pH and U(VI) initial concentration was investigated by batch technique. The removal kinetics of U(VI) on nZVI and nZVI/rGO were well simulated by a pseudo-first-order kinetic model and pseudo-second-order kinetic model, respectively. The presence of rGO on nZVI nanoparticles increased the reaction rate and removal capacity of U(VI) significantly, which was attributed to the chemisorbed OH{sup −} groups of rGO and the massive enrichment of Fe{sup 2+} on rGO surface by XPS analysis. The XRD analysis revealed that the presence of rGO retarded the transformation of iron corrosion products from magnetite/maghemite to lepidocrocite. According to the fitting of EXAFS spectra, the U-C (at ∼2.9 Å) and U-Fe (at ∼3.2 Å) shells were observed, indicating the formation of inner-sphere surface complexes on nZVI/rGO composites. Therefore, the nZVI/rGO composites can be suitable as efficient materials for the in-situ remediation of uranium-contaminated groundwater in the environmental pollution management.
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Sebayang, Perdamean; Kurniawan, Candra; Aryanto, Didik; Arief Setiadi, Eko; Tamba, Konni; Djuhana; Sudiro, Toto
2018-03-01
An adsorption method is one of the effective ways to filter the heavy metals wastes in aqueous system. In this paper, the Fe3O4/bentonite nanocomposites were successfully prepared from natural iron sand by co-precipitation method. The chemical process was carried out by dissolving and hot stirring the milled iron sand and bentonite in acid solution and precipitating it by NH4OH. The sediment was then washed using distilled water to neutralize pH and dried at 100 °C for 5 hours to produce Fe3O4/bentonite powders. The samples were characterized by XRD, FTIR, BET, TEM, VSM and AAS. All samples were composed by Fe3O4 single phase with a spinnel structure and lattice parameter of 8.373 Å. The transmittance peak of FTIR curve proved that the Fe3O4 particles and bentonite had a molecular bonding. The addition of bentonite to Fe3O4 nanoparticles generally reduced the magnetic properties of Fe3O4/bentonite nanocomposites. The optimum condition of 30 wt% bentonite resulted 105.9 m2/g in surface area, 14 nm in an average particle size and 3.2 nm in pore size. It can be used as Cu and Pb adsorbent materials.
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Effect of iron, taurine and arginine on rat hepatic fibrosis
International Nuclear Information System (INIS)
Song Liangwen; Wang Dewen; Cui Xuemei
1997-01-01
Objective: The promotion role of iron on pathogenesis of hepatic fibrosis and the protective role of taurine and L-arginine against hepatic fibrosis were studied. Method: The model of rat radiation hepatic fibrosis was used. Experimental rats were divided into 0 Gy, 30 Gy, 30 Gy + iron, 30 Gy + taurine and 30 Gy + L-arginine groups. Serum iron, liver tissue hydroxyproline (Hyp) and malondialdehyde (MDA) were measured one and three months respectively after irradiation of hepatic tissue, production and distribution characteristics of hepatic tissue type I and III collagen were observed with a polarizing microscope. Results: Administration of iron agent could significantly increase hepatic tissue MDA content and serum iron concentration, one month after irradiation, hepatic tissue Hyp in 30 Gy + iron group began to increase, and collagen in hepatic tissue obviously increased. Taurine and L-arginine could reduce serum iron concentration and decrease production of hepatic fissure Hyp. Conclusion: Exogenous iron agent could promote early development of radiation hepatic fibrosis; taurine and arginine could diminish pathologic alteration of hepatic fibrosis to a certain extent
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Effects of kinesio taping and hot packs on premenstrual syndrome in females.
Choi, Jung-Hyun
2017-09-01
[Purpose] This study aimed to evaluate the effects of taping and hot packs on premenstrual syndrome, in an attempt to generate basic data for physical therapy intervention for premenstrual syndrome. [Subjects and Methods] Thirty-two females in their 20s with premenstrual syndrome were randomly assigned to a taping group (n=10), hot pack group (n=11), and taping with hot pack group (n=11). Premenstrual syndrome was assessed using the Menstrual Distress Questionnaire in each participant prior to intervention and was re-assessed after applying kinesio taping and/or hot pack from 10 days before the estimated date of menstruation until the first day of menstruation. [Results] Data revealed that the taping and taping with hot pack groups showed significantly reduced premenstrual syndrome following intervention. In terms of the differences in the Menstrual Distress Questionnaire total score among the groups, the taping with hot pack and hot pack groups showed a significant difference. [Conclusion] These findings indicate that kinesio taping is an easy, non-drug intervention for female college students with premenstrual syndrome.
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49 CFR 192.373 - Service lines: Cast iron and ductile iron.
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...
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Transient Ischemic Attack Caused by Iron Deficiency Anemia
Directory of Open Access Journals (Sweden)
Ufuk Emre
2006-02-01
Full Text Available Transient Ischemic Attack Caused by Iron Deficiency Anemia Transient ischemic attacks are episodes of transient focal ischemia involving the brain or brainstem. They are commonly two to thirty minutes in duration and lasting less than 24 hours. Anemia of iron deficiency isn’t frequently cause for transient ischemic attack. It has been reported as a risk factor for childhood ischemic strokes. In the iron deficiency anemia, T‹A may develop as result of hypercoagulable state and increased viscosity that is caused by anemic hypoxia that is result of reduce hemoglobine level, seconder thrombosis and microcytose As iron deficiency anemia has been reported so rarely in adult patients with transient ischemic attacks as a cause, we aimed to discuss the clinical and outcome features of two cases with iron deficiency anemia and transient ischemic attacks in this study. Materials and methods: Routine neurologic examination, biochemical screen, serological tests, vasculitic markers, thyroid function tests, vitamin B 12 level, cranial imaging, vertebral carotid doppler USG examination was conducted in the two patients. Anemia of iron deficiency was found as the only risk factor for TIA and the two patients were treated with replacement of iron and antiagregan therapy. Neurological examination revealed no abnormality through the two years of follow-up. The iron deficiency anemia may be cause of many neurologic problems such a irritability, lethargy, headache, development retardation except from T‹A. In the iron deficiency anemia, early diagnosis and treatment is important
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Iron fortification of infant formulas. American Academy of Pediatrics. Committee on Nutrition.
1999-07-01
Despite the American Academy of Pediatrics' (AAP) strong endorsement for breastfeeding, most infants in the United States are fed some infant formula by the time they are 2 months old. The AAP Committee on Nutrition has strongly advocated iron fortification of infant formulas since 1969 as a way of reducing the prevalence of iron-deficiency anemia and its attendant sequelae during the first year.1 The 1976 statement titled "Iron Supplementation for Infants" delineated the rationale for iron supplementation, proposed daily dosages of iron, and summarized potential sources of iron in the infant diet.2 In 1989, the AAP Committee on Nutrition published a statement that addressed the issue of iron-fortified infant formulas3 and concluded that there was no convincing contraindication to iron-supplemented formulas and that continued use of "low-iron" formulas posed an unacceptable risk for iron deficiency during infancy. The current statement represents a scientific update and synthesis of the 1976 and 1989 statements with recommendations about the use of iron-fortified and low-iron formulas in term infants.
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Studies of instabilities and waves in a mirror confined hot electron plasma
International Nuclear Information System (INIS)
Huang Chaosong; Qiu Lijian; Ren Zhaoxing
1989-01-01
The stability of hot electron plasmas is studied. The hot electron component can stabilize the low frequency drift wave and the interchange mode driven by the plasma, which depends only on α=N h /N i , the density ratio of the hot electrons to the plasma ions, but not on the beta value and the annular structure of the hot electrons. Stabilization of the drift wave occurs for α > 40%, and that of the interchange mode for α > 5%, which allows the prediction that the interchange mode can be suppressed in hot electron plasma experiments. The experiments have been conducted in a simple mirror machine. It is observed that the plasma drives a drift wave at 40 kHz and an interchange mode at about 100 kHz. The fluctuation amplitude of the drift wave is much higher than that of the interchange mode. The hot electrons reduce the density gradient, the fluctuation amplitude and the radial loss of the plasma. On the other hand, the hot electrons drive the interchange mode and drift wave in the ion cyclotron frequency region. The effects of a cold plasma on hot electron perturbations are discussed. (author). 10 refs, 6 figs
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Iron crystallization in a fluidized-bed Fenton process.
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.
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Energy Technology Data Exchange (ETDEWEB)
Huang, Guan, E-mail: huangg66@126.com; Liu, Yao; Cai, Jing Li; Chen, Xiang Feng; Zhao, Shu Kai; Guo, Yong An; Wei, Su Juan; Li, Xu
2017-04-30
Graphical abstract: A biomimetic catalyst of iron-tetrakis(4-sulfonatophenyl)porphyrin immobilized on powdered chitosan achieves efficient cyclohexane oxidation with high ketone and alcohol yields. - Highlights: • Fe (TPPS)/pd-CTS is an excellent catalyst for cyclohexane oxidation. • Amino ligation alters the electron cloud density around the iron cation. • Amino coordination likely reduces the activation energy of Fe (TPPS). • The catalyst achieved 22.9 mol% yields of cyclohexanone and cyclohexanol. - Abstract: This study investigates how ligands modulate metalloporphyrin activity with the goal of producing a practical biomimetic catalyst for use in the chemical industry. We immobilized iron porphyrinate [iron-tetrakis-(4-sulfonatophenyl)-porphyrin; Fe(III) (TPPS)] on powdered chitosan (pd-CTS) to form an immobilized catalyst Fe(III) (TPPS)/pd-CTS, which was characterized using modern spectroscopic techniques and used for catalytic oxidation of cyclohexane with O{sub 2}. Amino coordination to iron porphyrin in Fe(III) (TPPS)/pd-CTS altered the electron cloud density around the iron cation, probably by reducing the activation energy of Fe(III) (TPPS) and raising the reactivity of the iron ion catalytic center, thereby improving the catalytic efficiency. One milligram of Fe(III) (TPPS) catalyst can be reused three times for the oxidation reaction to yield an average of 22.9 mol% of cyclohexanone and cyclohexanol.
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International Nuclear Information System (INIS)
Chatterjee, C.; Agarwala, S.C.
1979-01-01
Tomato (Lycopersicon esculentum Mill. var. Marglobe) plants were raised under controlled sand culture to study the interaction of molybdenum and iron supply on the uptake of molybdenum and iron and activity of certain enzymes affected by iron and/or molybdenum supply. Iron deficiency caused a decrease in the molybdenum uptake and accentuated the effect of molybdenum deficiency in reducing the uptake and more so the translocation of molybdenum from roots to shoots, thus inducing more severe molybdenum deficiency. The deficiency of iron and molybdenum decreased the activity of catalase, succinate dehydrogenase and nitrate reductase, the most marked decrease being found in plants supplied with both iron and molybdenum at low levels. Changes in the activities of nitrate reductase and catalase can be attributed to the interaction of iron and molybdenum supply in their absorption and translocation. (auth.)
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Metabolic activity in the insular cortex and hypothalamus predicts hot flashes: an FDG-PET study.
Joffe, Hadine; Deckersbach, Thilo; Lin, Nancy U; Makris, Nikos; Skaar, Todd C; Rauch, Scott L; Dougherty, Darin D; Hall, Janet E
2012-09-01
Hot flashes are a common side effect of adjuvant endocrine therapies (AET; leuprolide, tamoxifen, aromatase inhibitors) that reduce quality of life and treatment adherence in breast cancer patients. Because hot flashes affect only some women, preexisting neurobiological traits might predispose to their development. Previous studies have implicated the insula during the perception of hot flashes and the hypothalamus in thermoregulatory dysfunction. The aim of the study was to understand whether neurobiological factors predict hot flashes. [18F]-Fluorodeoxyglucose (FDG) positron emission tomography (PET) brain scans coregistered with structural magnetic resonance imaging were used to determine whether metabolic activity in the insula and hypothalamic thermoregulatory and estrogen-feedback regions measured before and in response to AET predict hot flashes. Findings were correlated with CYP2D6 genotype because of CYP2D6 polymorphism associations with tamoxifen-induced hot flashes. We measured regional cerebral metabolic rate of glucose uptake (rCMRglu) in the insula and hypothalamus on FDG-PET. Of 18 women without hot flashes who began AET, new-onset hot flashes were reported by 10 (55.6%) and were detected objectively in nine (50%) participants. Prior to the use of all AET, rCMRglu in the insula (P ≤ 0.01) and hypothalamic thermoregulatory (P = 0.045) and estrogen-feedback (P = 0.007) regions was lower in women who reported developing hot flashes. In response to AET, rCMRglu was further reduced in the insula in women developing hot flashes (P ≤ 0.02). Insular and hypothalamic rCMRglu levels were lower in intermediate than extensive CYP2D6 metabolizers. Trait neurobiological characteristics predict hot flashes. Genetic variability in CYP2D6 may underlie the neurobiological predisposition to hot flashes induced by AET.
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HOT AEROSOL FIRE EXTINGUISHING AGENTS AND THE ASSOCIATED TECHNOLOGIES: A REVIEW
Directory of Open Access Journals (Sweden)
Xiaotian Zhang
2015-09-01
Full Text Available AbstractSince the phase out of Halon extinguishers in the 1980s, hot aerosol fire suppression technology has gained much attention. Unlike traditional inert gas, foam, water mist and Halon fire suppression agents, hot aerosol fire extinguishing agents do not need to be driven out by pressurized gases and can extinguish class A, B, C, D and K fires at 30 to 200 g/m3. Generally, hot aerosol fire extinguishing technology has developed from a generation I oil tank suppression system to a generation III strontium salt based S-type system. S-type hot aerosol fire extinguishing technology greatly solves the corrosion problem of electrical devices and electronics compared to potassium salt based generation I & II hot aerosol fire extinguishing technology. As substitutes for Halon agents, the ODP and GWP values of hot fire extinguishing aerosols are nearly zero, but those fine aerosol particles can cause adverse health effects once inhaled by human. As for configurations of hot aerosol fire extinguishing devices, fixed or portable cylindrical canisters are the most common among generation II & III hot aerosol fire extinguishers across the world, while generation I hot aerosol fire suppression systems are integrated with the oil tank as a whole. Some countries like the U.S., Australia, Russia and China, etc. have already developed standards for manufacturing and quality control of hot aerosol fire extinguishing agents and norms for hot aerosol fire extinguishing system design under different fire protection scenarios. Coolants in hot aerosol fire suppression systems, which are responsible for reducing hot aerosol temperature to avoid secondary fire risk are reviewed for the first time. Cooling effects are generally achieved through vaporization and endothermic chemical decomposition of coolants. Finally, this review discussed areas applying generation I, II or III hot aerosol fire suppression technologies. The generation III hot aerosol fire extinguishing
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Directory of Open Access Journals (Sweden)
Mingfu Liu
2015-05-01
Full Text Available Dialysis patients with chronic renal failure receiving deferoxamine for treating iron overload are uniquely predisposed for mucormycosis, which is most often caused by Rhizopus oryzae. Although the deferoxamine siderophore is not secreted by Mucorales, previous studies established that Rhizopus species utilize iron from ferrioxamine (iron-rich form of deferoxamine. Here we determined that the CBS domain proteins of Fob1 and Fob2 act as receptors on the cell surface of R. oryzae during iron uptake from ferrioxamine. Fob1 and Fob2 cell surface expression was induced in the presence of ferrioxamine and bound radiolabeled ferrioxamine. A R. oryzae strain with targeted reduced Fob1/Fob2 expression was impaired for iron uptake, germinating, and growing on medium with ferrioxamine as the sole source of iron. This strain also exhibited reduced virulence in a deferoxamine-treated, but not the diabetic ketoacidotic (DKA, mouse model of mucormycosis. The mechanism by which R. oryzae obtains iron from ferrioxamine involves the reductase/permease uptake system since the growth on ferrioxamine supplemented medium is associated with elevated reductase activity and the use of the ferrous chelator bathophenanthroline disulfonate abrogates iron uptake and growth on medium supplemented with ferrioxamine as a sole source of iron. Finally, R. oryzae mutants with reduced copies of the high affinity iron permease (FTR1 or with decreased FTR1 expression had an impaired iron uptake from ferrioxamine in vitro and reduced virulence in the deferoxamine-treated mouse model of mucormycosis. These two receptors appear to be conserved in Mucorales, and can be the subject of future novel therapy to maintain the use of deferoxamine for treating iron-overload.
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Hydrogen Plasma Processing of Iron Ore
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.
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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
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International Nuclear Information System (INIS)
Langlais, F.; Hottier, F.; Cadoret, R.
1982-01-01
Silicon chemical vapour deposition (SiH 2 Cl 2 /H 2 system), under reduced pressure conditions, in a hot-wall reactor, is presented. The vapour phase composition is assessed by evaluating two distinct equilibria. The homogeneous equilibrium , which assumes that the vapour phase is not in equilibrium with solid silicon, is thought to give an adequate description of the vapour phase in the case of low pressure, high gas velocities, good temperature homogeneity conditions. A comparison with heterogeneous equilibrium enables us to calculate the supersaturation so evidencing a highly irreversible growth system. The experimental determination of the growth rates reveals two distinct temperature ranges: below 1000 0 C, polycrystalline films are usually obtained with a thermally activated growth rate (+40 kcal mole -1 ) and a reaction order, with respect to the predominant species SiCl 2 , close to one; above 1000 0 C, the films are always monocrystalline and their growth rate exhibits a much lower or even negative activation energy, the reaction order in SiCl 2 remaining about one. (orig.)
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Directory of Open Access Journals (Sweden)
Geng Wu
2017-07-01
Full Text Available Thioarsenates are common arsenic species in sulfidic geothermal waters, yet little is known about their biogeochemical traits. In the present study, a novel sulfate-reducing bacterial strain Desulfotomaculum TC-1 was isolated from a sulfidic hot spring in Tengchong geothermal area, Yunnan Province, China. The arxA gene, encoding anaerobic arsenite oxidase, was successfully amplified from the genome of strain TC-1, indicating it has a potential ability to oxidize arsenite under anaerobic condition. In anaerobic arsenite oxidation experiments inoculated with strain TC-1, a small amount of arsenate was detected in the beginning but became undetectable over longer time. Thioarsenates (AsO4-xSx2- with x = 1–4 formed with mono-, di- and tri-thioarsenates being dominant forms. Tetrathioarsenate was only detectable at the end of the experiment. These results suggest that thermophilic microbes might be involved in the formation of thioarsenates and provide a possible explanation for the widespread distribution of thioarsenates in terrestrial geothermal environments.
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Wu, Geng; Huang, Liuqin; Jiang, Hongchen; Peng, Yue'e; Guo, Wei; Chen, Ziyu; She, Weiyu; Guo, Qinghai; Dong, Hailiang
2017-01-01
Thioarsenates are common arsenic species in sulfidic geothermal waters, yet little is known about their biogeochemical traits. In the present study, a novel sulfate-reducing bacterial strain Desulfotomaculum TC-1 was isolated from a sulfidic hot spring in Tengchong geothermal area, Yunnan Province, China. The arxA gene, encoding anaerobic arsenite oxidase, was successfully amplified from the genome of strain TC-1, indicating it has a potential ability to oxidize arsenite under anaerobic condition. In anaerobic arsenite oxidation experiments inoculated with strain TC-1, a small amount of arsenate was detected in the beginning but became undetectable over longer time. Thioarsenates (AsO 4-x S x 2- with x = 1-4) formed with mono-, di- and tri-thioarsenates being dominant forms. Tetrathioarsenate was only detectable at the end of the experiment. These results suggest that thermophilic microbes might be involved in the formation of thioarsenates and provide a possible explanation for the widespread distribution of thioarsenates in terrestrial geothermal environments.
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Smectite alteration by anaerobic iron corrosion
International Nuclear Information System (INIS)
Sanders, D.; Kaufhold, S.; Hassel, A.W.; Dohrmann, R.
2010-01-01
Document available in extended abstract form only. The interaction of smectites with corroding steel/iron represents a crucial topic in the estimation of the long term confinement properties of clay barriers for the encasement of steel/iron containers. Especially in case of engineered clay barriers a possible deterioration of favourable smectite properties as response to corrosion could reduce the barrier capacity. The extent of this reduction is unknown, yet. The essential properties of bentonite clays in this context are on the one hand the relatively high swelling pressure together with low hydraulic conductivity, which results from the well known expandability of smectite interlayers in aqueous environments. On the other hand smectites are cation exchangers being able to long term encase radioactive cations in a way that negative charges of silicate layers are compensated by easily exchangeable hydrated cations. Both properties are directly related to the crystal and chemical composition of smectites. The nature of the corrosion of steel canisters in clay barriers will - after a first short aerobic phase - predominantly be anaerobic resulting in the formation of Fe(II) and two equivalents of hydroxide ions. In a set of exposition experiments anaerobic corroding iron in bentonite gels was studied in order to determine alteration of the smectite fraction. During the exposition a green coloration of the bentonite neighbouring to corroding iron was observed. Upon contact to oxygen in a humid state the bentonite turned reddish indicating the oxidation of Fe(II) to Fe(III). This observation is in accordance with reported results indicating the formation of an iron rich smectite. Chemical analysis of the 'green bentonite' reveals an increase of iron fraction e.g. from 3.4% mass to 9.3% mass . The adsorbed iron is predominantly Fe(II) which was proven by chromato-metric titration. The estimated ratio between silicon to increased iron content is Si: Fe ≅ 2
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Nucleation of iron nitrides during gaseous nitriding of iron; the effect of a preoxidation treatment
DEFF Research Database (Denmark)
Friehling, Peter B.; Poulsen, Finn Willy; Somers, Marcel A.J.
2001-01-01
grains. On prolonged nitriding, immediate nucleation at the surface of iron grains becomes possible. Calculated incubation times for the nucleation of gamma'-Fe4N1-x during nitriding are generally longer than those observed experimentally in the present work. The incubation time is reduced dramatically...
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Rejitha, V; Peter, M C Subhash
2013-01-15
The effects of in vivo adrenaline and triiodothyronine (T(3)) on ferric reductase (FR) activity, a membrane-bound enzyme that reduces Fe(III) to Fe(II) iron, were studied in the organs of climbing perch (Anabas testudineus Bloch). Adrenaline injection (10 ng g(-1)) for 30 min produced significant inhibition of FR activity in the liver and kidney and that suggests a role for this stress hormone in iron acquisition in this fish. Short-term T(3) injection (40 ng g(-1)) reduced FR activity in the gills of fed fish but not in the unfed fish. Similar reduction of FR activity was also obtained in the intestine and kidney of fed fish after T(3) injection. Feeding produced pronounced decline in FR activity in the spleen but T(3) challenge in fed and unfed fish increased its activity in this iron storing organ and that point to the sensitivity of FR system to feeding activity. The in vitro effects of Fe on FR activity in the gill explants of freshwater fish showed correlations of FR with Na(+), K(+)-ATPase and H(+)-ATPase activities. Substantial increase in the FR activity was found in the gill explants incubated with all the tested doses of Fe(II) iron (1.80, 3.59 and 7.18 μM) and Fe(III) iron (1.25, 2.51 and 5.02 μM) and this indicate that FR and Na pump activity are positively correlated. On the contrary, substantial reduction of gill H(+)-ATPase activity was found in the gill explants incubated with Fe(II) iron and Fe(III) iron indicating that perch gills may not require a high acidic microenvironment for the reduction of Fe(III) iron. Accumulation of iron in the gill explants after Fe(III) iron incubation implies a direct relationship between Fe acquisition and FR activity in this tissue. The inverse correlation between FR activity and H(+)-ATPase activity in Fe(II) or Fe(III) loaded gills and the significant positive correlations of FR activity with total [Fe] content in the Fe(III) loaded gills substantiate that FR which shows sensitivity to sodium and proton pumps
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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.
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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
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Nairz, Manfred; Schleicher, Ulrike; Schroll, Andrea; Sonnweber, Thomas; Theurl, Igor; Ludwiczek, Susanne; Talasz, Heribert; Brandacher, Gerald; Moser, Patrizia L.; Muckenthaler, Martina U.; Fang, Ferric C.; Bogdan, Christian
2013-01-01
Nitric oxide (NO) generated by inducible NO synthase 2 (NOS2) affects cellular iron homeostasis, but the underlying molecular mechanisms and implications for NOS2-dependent pathogen control are incompletely understood. In this study, we found that NO up-regulated the expression of ferroportin-1 (Fpn1), the major cellular iron exporter, in mouse and human cells. Nos2−/− macrophages displayed increased iron content due to reduced Fpn1 expression and allowed for an enhanced iron acquisition by the intracellular bacterium Salmonella typhimurium. Nos2 gene disruption or inhibition of NOS2 activity led to an accumulation of iron in the spleen and splenic macrophages. Lack of NO formation resulted in impaired nuclear factor erythroid 2-related factor-2 (Nrf2) expression, resulting in reduced Fpn1 transcription and diminished cellular iron egress. After infection of Nos2−/− macrophages or mice with S. typhimurium, the increased iron accumulation was paralleled by a reduced cytokine (TNF, IL-12, and IFN-γ) expression and impaired pathogen control, all of which were restored upon administration of the iron chelator deferasirox or hyperexpression of Fpn1 or Nrf2. Thus, the accumulation of iron in Nos2−/− macrophages counteracts a proinflammatory host immune response, and the protective effect of NO appears to partially result from its ability to prevent iron overload in macrophages PMID:23630227
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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)
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Microbial synthesis of iron-based nanomaterials—A review
Indian Academy of Sciences (India)
Nanoparticles; biosynthesis; microbes; iron reducing bacteria; sulphate reducing bacteria; magnetotactic bacteria. 1. Introduction. Nanoparticles are considered to be the building blocks for nanotechnology and are referred to as the particles having one or more dimensions of the order of 100 nm or less. (Huber 2005).
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Parkinson, Gareth S.
2016-03-01
The current status of knowledge regarding the surfaces of the iron oxides, magnetite (Fe3O4), maghemite (γ-Fe2O3), haematite (α-Fe2O3), and wüstite (Fe1-xO) is reviewed. The paper starts with a summary of applications where iron oxide surfaces play a major role, including corrosion, catalysis, spintronics, magnetic nanoparticles (MNPs), biomedicine, photoelectrochemical water splitting and groundwater remediation. The bulk structure and properties are then briefly presented; each compound is based on a close-packed anion lattice, with a different distribution and oxidation state of the Fe cations in interstitial sites. The bulk defect chemistry is dominated by cation vacancies and interstitials (not oxygen vacancies) and this provides the context to understand iron oxide surfaces, which represent the front line in reduction and oxidation processes. Fe diffuses in and out from the bulk in response to the O2 chemical potential, forming sometimes complex intermediate phases at the surface. For example, α-Fe2O3 adopts Fe3O4-like surfaces in reducing conditions, and Fe3O4 adopts Fe1-xO-like structures in further reducing conditions still. It is argued that known bulk defect structures are an excellent starting point in building models for iron oxide surfaces. The atomic-scale structure of the low-index surfaces of iron oxides is the major focus of this review. Fe3O4 is the most studied iron oxide in surface science, primarily because its stability range corresponds nicely to the ultra-high vacuum environment. It is also an electrical conductor, which makes it straightforward to study with the most commonly used surface science methods such as photoemission spectroscopies (XPS, UPS) and scanning tunneling microscopy (STM). The impact of the surfaces on the measurement of bulk properties such as magnetism, the Verwey transition and the (predicted) half-metallicity is discussed. The best understood iron oxide surface at present is probably Fe3O4(100); the structure is
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... 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 ...
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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 ...
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Super-iron Nanoparticles with Facile Cathodic Charge Transfer
Energy Technology Data Exchange (ETDEWEB)
M Farmand; D Jiang; B Wang; S Ghosh; D Ramaker; S Licht
2011-12-31
Super-irons contain the + 6 valence state of iron. One advantage of this is that it provides a multiple electron opportunity to store additional battery charge. A decrease of particle size from the micrometer to the nanometer domain provides a higher surface area to volume ratio, and opportunity to facilitate charge transfer, and improve the power, voltage and depth of discharge of cathodes made from such salts. However, super-iron salts are fragile, readily reduced to the ferric state, with both heat and contact with water, and little is known of the resultant passivating and non-passivating ferric oxide products. A pathway to decrease the super-iron particle size to the nano-domain is introduced, which overcomes this fragility, and retains the battery capacity advantage of their Fe(VI) valence state. Time and power controlled mechanosynthesis, through less aggressive, dry ball milling, leads to facile charge transfer of super-iron nanoparticles. Ex-situ X-ray Absorption Spectroscopy is used to explore the oxidation state and structure of these iron oxides during discharge and shows the significant change in stability of the ferrate structure to lower oxidation state when the particle size is in the nano-domain.
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Development of the Thyssen hot briquetting process and its industrial application
Energy Technology Data Exchange (ETDEWEB)
Hoeffken, E.; Pflipsen, H.D.; Seidelmann, L.; Auth, R.
1988-07-18
At Thyssen Stahl AG the converter waste gases of the basic oxygen steelmaking plant Bruckhausen are dedusted according to a new method , the CO included in the waste gas being recovered and used as fuel gas. The dry dusts produced in this process are dumped despite their high iron content. Considerations aimed at recovering this residues have led to the development of a hot briquetting process for converter dusts. Preliminary tests were followedby the construction of a pilot plant with a briqueting capacity of 2 to 3 t/h. As a result of the successful trials, a large-size plant for a throughput rate of 12 t/h was commissioned at mid-1987, which allows to briquet all the dusts produced in the steel plant. About 30000 t briquettes, which are charged as cooling ore and scrap in the steel plant, have been produced so far. In view of the high iron content of 60 to 70% and of the elimination of dumping costs, the process can be operated economically. The recycling of the dust has contributed, moreover, to the relief of the dumping ground and to environmental protection.
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Directory of Open Access Journals (Sweden)
Yu J.
2018-01-01
Full Text Available In this investigation, a pilot-scale fluidized magnetization roasting reactor was introduced and used to enhance magnetic properties of iron ore. Consequently, the effects of roasting temperature, reducing gas CO flow rate, and fluidizing gas N2 flow rate on the magnetization roasting performance were studied. The results indicated that the hematite was almost completely converted into magnetite by a gas mixture of 4 Nm3/h CO and 1 Nm3/h N2 at roasting temperature of 540°C for about 30 s. Under optimized conditions, a high grade concentrate containing 66.84% iron with iron recovery of 91.16% was achieved. The XRD, VSM, and optical microscopy (OM analyses revealed that most of the hematite, except some coarse grains, was selectively converted to magnetite, and that the magnetic properties were greatly enhanced. Thus, their separation from non-magnetic gangue minerals was facilitated.
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Dai, Shuhui; Hua, Ya; Keep, Richard F; Novakovic, Nemanja; Fei, Zhou; Xi, Guohua
2018-06-05
Brain iron overload is involved in brain injury after intracerebral hemorrhage (ICH). There is evidence that systemic administration of minocycline reduces brain iron level and improves neurological outcome in experimental models of hemorrhagic and ischemic stroke. However, there is evidence in cerebral ischemia that minocycline is not protective in aged female animals. Since most ICH research has used male models, this study was designed to provide an overall view of ICH-induced iron deposits at different time points (1 to 28 days) in aged (18-month old) female Fischer 344 rat ICH model and to investigate the neuroprotective effects of minocycline in those rats. According to our previous studies, we used the following dosing regimen (20 mg/kg, i.p. at 2 and 12 h after ICH onset followed by 10 mg/kg, i.p., twice a day up to 7 days). T2-, T2 ⁎ -weighted and T2 ⁎ array MRI was performed at 1, 3, 7 and 28 days to measure brain iron content, ventricle volume, lesion volume and brain swelling. Immunohistochemistry was used to examine changes in iron handling proteins, neuronal loss and microglial activation. Behavioral testing was used to assess neurological deficits. In aged female rats, ICH induced long-term perihematomal iron overload with upregulated iron handling proteins, neuroinflammation, brain atrophy, neuronal loss and neurological deficits. Minocycline significantly reduced ICH-induced perihematomal iron overload and iron handling proteins. It further reduced brain swelling, neuroinflammation, neuronal loss, delayed brain atrophy and neurological deficits. These effects may be linked to the role of minocycline as an iron chelator as well as an inhibitor of neuroinflammation. Copyright © 2018 Elsevier Inc. All rights reserved.
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Directory of Open Access Journals (Sweden)
Ponomarenko, O.M.
2016-01-01
Full Text Available New facility for continuous registration of iron ore magnetization depending on temperature by heating of iron ores upon reducing conditions was created. Facility allows to register the processes of transformation of weakly magnetic minerals into strongly magnetic ones under the influence of reducing agents and temperature, as well as to determine the Curie temperature of the minerals. Using created facility it was shown, that heating of goethite and hematite in the presence of 4 % of starch in the temperature range of 300—650 °С leads to significant increase of magnetization of the samples. X-Ray diffraction confirmed that under indicated conditions the structure of hematite and goethite is transformed into magnetite structure. Obtained results open up new possibilities for the development of effective technologies for oxidized iron ore beneficiation.
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Black reefs: iron-induced phase shifts on coral reefs.
Kelly, Linda Wegley; Barott, Katie L; Dinsdale, Elizabeth; Friedlander, Alan M; Nosrat, Bahador; Obura, David; Sala, Enric; Sandin, Stuart A; Smith, Jennifer E; Vermeij, Mark J A; Williams, Gareth J; Willner, Dana; Rohwer, Forest
2012-03-01
The Line Islands are calcium carbonate coral reef platforms located in iron-poor regions of the central Pacific. Natural terrestrial run-off of iron is non-existent and aerial deposition is extremely low. However, a number of ship groundings have occurred on these atolls. The reefs surrounding the shipwreck debris are characterized by high benthic cover of turf algae, macroalgae, cyanobacterial mats and corallimorphs, as well as particulate-laden, cloudy water. These sites also have very low coral and crustose coralline algal cover and are call black reefs because of the dark-colored benthic community and reduced clarity of the overlying water column. Here we use a combination of benthic surveys, chemistry, metagenomics and microcosms to investigate if and how shipwrecks initiate and maintain black reefs. Comparative surveys show that the live coral cover was reduced from 40 to 60% to reefs on Millennium, Tabuaeran and Kingman. These three sites are relatively large (>0.75 km(2)). The phase shift occurs rapidly; the Kingman black reef formed within 3 years of the ship grounding. Iron concentrations in algae tissue from the Millennium black reef site were six times higher than in algae collected from reference sites. Metagenomic sequencing of the Millennium Atoll black reef-associated microbial community was enriched in iron-associated virulence genes and known pathogens. Microcosm experiments showed that corals were killed by black reef rubble through microbial activity. Together these results demonstrate that shipwrecks and their associated iron pose significant threats to coral reefs in iron-limited regions.
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Energy Technology Data Exchange (ETDEWEB)
Kucheryavy, Pavel; Lahanas, Nicole; Velasco, Ever; Sun, Cheng-Jun; Lockard, Jenny V.
2016-04-07
An iron porphyrin-based metal organic framework, PCN-222(Fe) is investigated upon post-synthetic reduction with piperidine. Fe K-edge X-ray absorption and Kβ mainline emission spectroscopy measurements reveal the local coor-dination geometry, oxidation and spin state changes experi-enced by the Fe sites upon reaction with this axially coordi-nating reducing agent. Analysis and fitting of these data con-firm the binding pattern predicted by a space filling model of the structurally constrained pore environments. These results are further support by UV-vis diffuse reflectance, IR and Raman spectroscopy data.
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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- ...
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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 ...
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In Vitro Iron Bioavailability of Brazilian Food-Based by-Products.
Chiocchetti, Gabriela M; De Nadai Fernandes, Elisabete A; Wawer, Anna A; Fairweather-Tait, Susan; Christides, Tatiana
2018-05-16
Background : Iron deficiency is a public health problem in many low- and middle-income countries. Introduction of agro-industrial food by-products, as additional source of nutrients, could help alleviate this micronutrient deficiency, provide alternative sources of nutrients and calories in developed countries, and be a partial solution for disposal of agro-industry by-products. Methods : The aim of this study was to determine iron bioavailability of 5 by-products from Brazilian agro-industry (peels from cucumber, pumpkin, and jackfruit, cupuaçu seed peel, and rice bran), using the in vitro digestion/ Caco-2 cell model; with Caco-2 cell ferritin formation as a surrogate marker of iron bioavailability. Total and dialyzable Fe, macronutrients, the concentrations of iron-uptake inhibitors (phytic acid, tannins, fiber) and their correlation with iron bioavailability were also evaluated. Results : The iron content of all by-products was high, but the concentration of iron and predicted bioavailability were not related. Rice bran and cupuaçu seed peel had the highest amount of phytic acid and tannins, and lowest iron bioavailability. Cucumber peels alone, and with added extrinsic Fe, and pumpkin peels with extrinsic added iron, had the highest iron bioavailability. Conclusion : The results suggest that cucumber and pumpkin peel could be valuable alternative sources of bioavailable Fe to reduce iron deficiency in at-risk populations.
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Dry reforming of methane with CO2 on an electron-activated iron catalytic bed.
Labrecque, Raynald; Lavoie, Jean-Michel
2011-12-01
A preliminary experimental investigation of dry reforming of methane with carbon dioxide, that has been performed on an iron bed activated with an electric current is reported. Operating conditions for the reaction included temperature ranging from 700 to 800° C and pressure close to 1 atm. The reaction, involving an excess of pure methane and carbon dioxide, was performed with and without addition of water vapour, provided by hot water saturation of the gaseous feed. According to syngas compositions, the electron flow has a dramatic effect on the conversion of both methane and carbon dioxide. It was shown also that hot water saturation of the CO(2) and CH(4) mixture allowed very good conversion, giving a syngas with a composition very close to what was expected from equilibrium calculations. Copyright © 2011 Elsevier Ltd. All rights reserved.
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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 ...
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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.
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Carbonate ion-enriched hot spring water promotes skin wound healing in nude rats.
Directory of Open Access Journals (Sweden)
Jingyan Liang
Full Text Available Hot spring or hot spa bathing (Onsen is a traditional therapy for the treatment of certain ailments. There is a common belief that hot spring bathing has therapeutic effects for wound healing, yet the underlying molecular mechanisms remain unclear. To examine this hypothesis, we investigated the effects of Nagano hot spring water (rich in carbonate ion, 42°C on the healing process of the skin using a nude rat skin wound model. We found that hot spring bathing led to an enhanced healing speed compared to both the unbathed and hot-water (42°C control groups. Histologically, the hot spring water group showed increased vessel density and reduced inflammatory cells in the granulation tissue of the wound area. Real-time RT-PCR analysis along with zymography revealed that the wound area of the hot spring water group exhibited a higher expression of matrix metalloproteinases-2 and -9 compared to the two other control groups. Furthermore, we found that the enhanced wound healing process induced by the carbonate ion-enriched hot spring water was mediated by thermal insulation and moisture maintenance. Our results provide the evidence that carbonate ion-enriched hot spring water is beneficial for the treatment of skin wounds.
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Mammalian iron metabolism and its control by iron regulatory proteins☆
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
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Rapid collection of iron hydroxide for determination of Th isotopes in seawater
Energy Technology Data Exchange (ETDEWEB)
Okubo, Ayako, E-mail: okubo.ayako@jaea.go.jp [Japan Atomic Energy Agency, Research Group for Analytical Chemistry (Japan); Obata, Hajime, E-mail: obata@aori.u-tokyo.ac.jp [Atmosphere Ocean Research Institute, The University of Tokyo (Japan); Magara, Masaaki, E-mail: magara.masaaki@jaea.go.jp [Japan Atomic Energy Agency, Research Group for Analytical Chemistry (Japan); Kimura, Takaumi, E-mail: kimura.takaumi@jaea.go.jp [Japan Atomic Energy Agency, Research Group for Analytical Chemistry (Japan); Ogawa, Hiroshi, E-mail: hogawa@aori.u-tokyo.ac.jp [Atmosphere Ocean Research Institute, The University of Tokyo (Japan)
2013-12-04
Graphical abstract: -- Highlights: •DIAION CR-20 chelating resin has successfully collected iron-hydroxide with Th isotopes. •Ferric ions in the iron hydroxide were bonded to functional groups of the chelating resin. •The time of preconcentration step was markedly reduced from a few days to 3–4 h. -- Abstract: This work introduces a novel method of recovery of iron hydroxide using a DIAION CR-20 chelating resin column to determine Th isotopes in seawater with a sector field (SF) inductively coupled plasma mass spectrometer (ICP-MS). Thorium isotopes in seawater were co-precipitated with iron hydroxide, and this precipitate was sent to chelating resin column. Ferric ions in the iron hydroxide were bonded to functional groups of the chelating resin directly, resulting in a pH increase of the effluent by release of hydroxide ion from the iron hydroxide. The co-precipitated thorium isotopes were quantitatively collected within the column, which indicated that thorium was retained on the iron hydroxide remaining on the chelating column. The chelating column quantitatively collected {sup 232}Th with iron hydroxide in seawater at flow rates of 20–25 mL min{sup −1}. Based on this flow rate, a 5 L sample was processed within 3–4 h. The >20 h aging of iron hydroxide tends to reduce the recovery of {sup 232}Th. The rapid collection method was successfully applied to the determination of {sup 230}Th and {sup 232}Th in open-ocean seawater samples.
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Iron-binding haemerythrin RING ubiquitin ligases regulate plant iron responses and accumulation
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
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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
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Li, Yongchao; Hu, Xiaoxian; Ren, Bozhi
2016-01-01
The present article summarizes antimony mine distribution, antimony mine drainage generation and environmental impacts, and critically analyses the remediation approach with special emphasis on iron oxidizing bacteria and sulfate reducing bacteria. Most recent research focuses on readily available low-cost adsorbents, such as minerals, wastes, and biosorbents. It is found that iron oxides prepared by chemical methods present superior adsorption ability for Sb(III) and Sb(V). However, this process is more costly and iron oxide activity can be inhibited by plenty of sulfate in antimony mine drainage. In the presence of sulfate reducing bacteria, sulfate can be reduced to sulfide and form Sb(2)S(3) precipitates. However, dissolved oxygen and lack of nutrient source in antimony mine drainage inhibit sulfate reducing bacteria activity. Biogenetic iron oxide minerals from iron corrosion by iron-oxidizing bacteria may prove promising for antimony adsorption, while the micro-environment generated from iron corrosion by iron oxidizing bacteria may provide better growth conditions for symbiotic sulfate reducing bacteria. Finally, based on biogenetic iron oxide adsorption and sulfate reducing bacteria followed by precipitation, the paper suggests an alternative treatment for antimony mine drainage that deserves exploration.
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Siderophore-mediated iron trafficking in humans is regulated by iron
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
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Moehler, S.; Sweigart, A. V.; Landsman, W. B.; Heber, U.
2000-01-01
Atmospheric parameters (T(sub eff), log g), masses and helium abundances are derived for 42 hot horizontal branch (HB) stars in the globular cluster NGC6752. For 19 stars we derive magnesium and iron abundances as well and find that iron is enriched by a factor of 50 on average with respect to the cluster abundance whereas the magnesium abundances are consistent with the cluster abundance. Radiation pressure may levitate heavy elements like iron to the surface of the star in a diffusive process. Taking into account the enrichment of heavy elements in our spectroscopic analyses we find that high iron abundances can explain part, but not all, of the problem of anomalously low gravities along the blue HB. The blue HB stars cooler than about 15,100 K and the sdB stars (T(sub eff) greater than or = 20,000 K) agree well with canonical theory when analysed with metal-rich ([M/H] = +0.5) model atmospheres, but the stars in between these two groups remain offset towards lower gravities and masses. Deep Mixing in the red giant progenitor phase is discussed as another mechanism that may influence the position of the blue HB stars in the (T(sub eff), log g)-plane but not their masses.
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XPS and FTIR spectroscopic study on microwave treated high phosphorus iron ore
International Nuclear Information System (INIS)
Omran, Mamdouh; Fabritius, Timo; Elmahdy, Ahmed M.; Abdel-Khalek, Nagui A.; El-Aref, Mortada; Elmanawi, Abd El-Hamid
2015-01-01
Highlights: • The effect of microwave radiation on structure and chemical state of high phosphorus iron ore was studied. • FTIR analyses showed that after microwave radiation the functional chemical groups of phosphorus bearing minerals (fluorapatite) dissociated. • High resolution XPS analyses of Fe 2p peaks showed that after microwave radiation a portion of Fe(+III) was reduced to Fe(+II). • Microwave radiation had a positive effect on the magnetic properties of iron oxide, through formation of ferromagnetic phases. - Abstract: A growing interest in microwave heating has emerged recently. Several potential microwave applications regarding minerals’ processing have been investigated. This paper investigates the effect of microwave radiation on Egyptian high phosphorus iron ore. Three different iron ore samples have varying Fe 2 O 3 and P 2 O 5 contents and mineralogical textures were studied. A comparative study has been carried out between untreated and microwave treated iron ore. XRD and FTIR analyses showed that after microwave radiation the crystallinity of iron bearing minerals (hematite) increased, while the functional chemical groups of phosphorus bearing minerals (fluorapatite) and other gangues dissociated. High resolution XPS analyses of Fe 2p peaks showed that after microwave radiation a portion of Fe(+III) was reduced to Fe(+II). This means that after microwave radiation iron oxide (hematite, Fe 3+ ) transformed into more magnetic phase. The results indicated that microwave radiation had a positive effect on the magnetic properties of iron oxide, through formation of ferromagnetic phases
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Influence of Atmospheric Processes on the Solubility and Composition of Iron in Saharan Dust.
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.
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Random phase plate hot spots and their effect on stimulated Brillouin backscatter and self-focusing
International Nuclear Information System (INIS)
Rose, H.A.
1995-01-01
Laser hot spots, as determined by Random Phase Plate (RPP) hot spots, control the critical value of the average intensity, I c , at which there is a rapid onset of stimulated scatter in the strongly damped convective regime of three wave parametric instabilities. For the case of stimulated Brillouin backscatter in a long scale length plasma, nascent hot spot ponderomotive self-focusing is shown to reduce the value of I c in the regime of very strongly damped acoustic waves. RPP hot spots have two, intrinsically nonlinear, thresholds for ponderomotive self-focusing. Large intensity amplifications occur in the hot spot neighborhood when the hot spot power exceeds a certain critical power, P c , which is independent of the optic's f number, F. When the second, F-dependent, hot spot power threshold is exceeded, a filament emerges from the far side of the hot spot, whose extent grows erratically in time
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Iron-carbonate interaction at Earth's core-mantle boundary
Dorfman, S. M.; Badro, J.; Nabiei, F.; Prakapenka, V.; Gillet, P.
2015-12-01
Carbon storage and flux in the deep Earth are moderated by oxygen fugacity and interactions with iron-bearing phases. The amount of carbon stored in Earth's mantle versus the core depends on carbon-iron chemistry at the core-mantle boundary. Oxidized carbonates subducted from Earth's surface to the lowermost mantle may encounter reduced Fe0 metal from disproportionation of Fe2+ in lower mantle silicates or mixing with the core. To understand the fate of carbonates in the lowermost mantle, we have performed experiments on sandwiches of single-crystal (Ca0.6Mg0.4)CO3 dolomite and Fe foil in the laser-heated diamond anvil cell at lower mantle conditions of 49-110 GPa and 1800-2500 K. Syntheses were conducted with in situ synchrotron X-ray diffraction to identify phase assemblages. After quench to ambient conditions, samples were sectioned with a focused Ga+ ion beam for composition analysis with transmission electron microscopy. At the centers of the heated spots, iron melted and reacted completely with the carbonate to form magnesiowüstite, iron carbide, diamond, magnesium-rich carbonate and calcium carbonate. In samples heated at 49 and 64 GPa, the two carbonates exhibit a eutectoid texture. In the sample heated at 110 GPa, the carbonates form rounded ~150-nm-diameter grains with a higher modal proportion of interspersed diamonds. The presence of reduced iron in the deep lower mantle and core-mantle boundary region will promote the formation of diamonds in carbonate-bearing subducted slabs. The complete reaction of metallic iron to oxides and carbides in the presence of mantle carbonate supports the formation of these phases at the Earth's core-mantle boundary and in ultra-low velocity zones.
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Direct Biohydrometallurgical Extraction of Iron from Ore. Final Technical Report
International Nuclear Information System (INIS)
T.C. Eisele
2005-01-01
A completely novel approach to iron extraction was investigated, based on reductive leaching of iron by anaerobic bacteria. Microorganisms were collected from an anaerobic bog where natural seepage of dissolved iron was observed. This mixed culture was used to reduce insoluble iron in a magnetite ore to the soluble ferrous (Fe +2 ) state. While dissolution rates were slow, concentrations of dissolved iron as high as 3487 mg/l could be reached if sufficient time was allowed. A factorial study of the effects of trace nutrients and different forms of organic matter indicated that the best dissolution rates and highest dissolved iron concentrations were achieved using soluble carbohydrate (sucrose) as the bacterial food source, and that nutrients other than nitrogen, phosphorus, potassium, sodium, and acetate were not necessary. A key factor in reaching high levels of dissolved iron was maintaining a high level of carbon dioxide in solution, since the solubility of iron carbonates increases markedly as the quantity of dissolved carbon dioxide increases. Once the iron is dissolved, it has been demonstrated that the ferrous iron can then be electroplated from solution, provided that the concentration of iron is sufficiently high and the hydrogen ion concentration is sufficiently low. However, if the leaching solution is electrolyzed directly, organic matter precipitates at the cathode along with the metallic iron. To prevent this problem, the ferrous iron should be separated from the bulk solution in a more concentrated, purified form. One route to accomplishing this is to take advantage of the change in solubility of ferrous iron as a function of carbon dioxide concentration. By cycling the concentration of carbon dioxide in solution, it is possible to produce an iron-rich concentrate that should be suitable for electrolysis. This represents the first viable hydrometallurgical method for leaching iron directly from ore and producing metallic iron
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Direct Biohydrometallurgical Extraction of Iron from Ore. Final technical report
International Nuclear Information System (INIS)
T.C. Eisele
2005-01-01
A completely novel approach to iron extraction was investigated, based on reductive leaching of iron by anaerobic bacteria. Microorganisms were collected from an anaerobic bog where natural seepage of dissolved iron was observed. This mixed culture was used to reduce insoluble iron in a magnetite ore to the soluble ferrous (Fe +2 ) state. While dissolution rates were slow, concentrations of dissolved iron as high as 3487 mg/l could be reached if sufficient time was allowed. A factorial study of the effects of trace nutrients and different forms of organic matter indicated that the best dissolution rates and highest dissolved iron concentrations were achieved using soluble carbohydrate (sucrose) as the bacterial food source, and that nutrients other than nitrogen, phosphorus, potassium, sodium, and acetate were not necessary. A key factor in reaching high levels of dissolved iron was maintaining a high level of carbon dioxide in solution, since the solubility of iron carbonates increases markedly as the quantity of dissolved carbon dioxide increases. Once the iron is dissolved, it has been demonstrated that the ferrous iron can then be electroplated from solution, provided that the concentration of iron is sufficiently high and the hydrogen ion concentration is sufficiently low. However, if the leaching solution is electrolyzed directly, organic matter precipitates at the cathode along with the metallic iron. To prevent this problem, the ferrous iron should be separated from the bulk solution in a more concentrated, purified form. One route to accomplishing this is to take advantage of the change in solubility of ferrous iron as a function of carbon dioxide concentration. By cycling the concentration of carbon dioxide in solution, it is possible to produce an iron-rich concentrate that should be suitable for electrolysis. This represents the first viable hydrometallurgical method for leaching iron directly from ore and producing metallic iron