The Nanofabrication and Application of Substrates for Surface-Enhanced Raman Scattering

Directory of Open Access Journals (Sweden)

Xian Zhang

2012-01-01

Full Text Available Surface-enhanced Raman scattering (SERS was discovered in 1974 and impacted Raman spectroscopy and surface science. Although SERS has not been developed to be an applicable detection tool so far, nanotechnology has promoted its development in recent decades. The traditional SERS substrates, such as silver electrode, metal island film, and silver colloid, cannot be applied because of their enhancement factor or stability, but newly developed substrates, such as electrochemical deposition surface, Ag porous film, and surface-confined colloids, have better sensitivity and stability. Surface enhanced Raman scattering is applied in other fields such as detection of chemical pollutant, biomolecules, DNA, bacteria, and so forth. In this paper, the development of nanofabrication and application of surface-enhanced Ramans scattering substrate are discussed.

Safety Profile of TiO2-Based Photocatalytic Nanofabrics for Indoor Formaldehyde Degradation

Directory of Open Access Journals (Sweden)

Guixin Cui

2015-11-01

Full Text Available Anatase TiO2 nanoparticles (TNPs are synthesized using the sol-gel method and loaded onto the surface of polyester-cotton (65/35 fabrics. The nanofabrics degrade formaldehyde at an efficiency of 77% in eight hours with visible light irradiation or 97% with UV light. The loaded TNPs display very little release from nanofabrics (~0.0% during a standard fastness to rubbing test. Assuming TNPs may fall off nanofabrics during their life cycles, we also examine the possible toxicity of TNPs to human cells. We found that up to a concentration of 220 μg/mL, they do not affect viability of human acute monocytic leukemia cell line THP-1 macrophages and human liver and kidney cells.

Friction-induced nanofabrication on monocrystalline silicon

International Nuclear Information System (INIS)

Yu Bingjun; Qian Linmao; Yu Jiaxin; Zhou Zhongrong; Dong Hanshan; Chen Yunfei

2009-01-01

Fabrication of nanostructures has become a major concern as the scaling of device dimensions continues. In this paper, a friction-induced nanofabrication method is proposed to fabricate protrusive nanostructures on silicon. Without applying any voltage, the nanofabrication is completed by sliding an AFM diamond tip on a sample surface under a given normal load. Nanostructured patterns, such as linear nanostructures, nanodots or nanowords, can be fabricated on the target surface. The height of these nanostructures increases rapidly at first and then levels off with the increasing normal load or number of scratching cycles. TEM analyses suggest that the friction-induced hillock is composed of silicon oxide, amorphous silicon and deformed silicon structures. Compared to the tribochemical reaction, the amorphization and crystal defects induced by the mechanical interaction may have played a dominating role in the formation of the hillocks. Similar to other proximal probe methods, the proposed method enables fabrication at specified locations and facilitates measuring the dimensions of nanostructures with high precision. It is highlighted that the fabrication can also be realized on electrical insulators or oxide surfaces, such as quartz and glass. Therefore, the friction-induced method points out a new route in fabricating nanostructures on demand.

High resolution UV spectroscopy and laser-focused nanofabrication

NARCIS (Netherlands)

Myszkiewicz, G.

2005-01-01

This thesis combines two at first glance different techniques: High Resolution Laser Induced Fluorescence Spectroscopy (LIF) of small aromatic molecules and Laser Focusing of atoms for Nanofabrication. The thesis starts with the introduction to the high resolution LIF technique of small aromatic

Low power femtosecond tip-based nanofabrication with advanced control

Science.gov (United States)

Liu, Jiangbo; Guo, Zhixiong; Zou, Qingze

2018-02-01

In this paper, we propose an approach to enable the use of low power femtosecond laser in tip-based nanofabrication (TBN) without thermal damage. One major challenge in laser-assisted TBN is in maintaining precision control of the tip-surface positioning throughout the fabrication process. An advanced iterative learning control technique is exploited to overcome this challenge in achieving high-quality patterning of arbitrary shape on a metal surface. The experimental results are analyzed to understand the ablation mechanism involved. Specifically, the near-field radiation enhancement is examined via the surface-enhanced Raman scattering effect, and it was revealed the near-field enhanced plasma-mediated ablation. Moreover, silicon nitride tip is utilized to alleviate the adverse thermal damage. Experiment results including line patterns fabricated under different writing speeds and an "R" pattern are presented. The fabrication quality with regard to the line width, depth, and uniformity is characterized to demonstrate the efficacy of the proposed approach.

Reduction of ferric iron by acidophilic heterotrophic bacteria: evidence for constitutive and inducible enzyme systems in Acidiphilium spp.

Science.gov (United States)

Johnson, D B; Bridge, T A M

2002-01-01

To compare the abilities of two obligately acidophilic heterotrophic bacteria, Acidiphilium acidophilum and Acidiphilium SJH, to reduce ferric iron to ferrous when grown under different culture conditions. Bacteria were grown in batch culture, under different aeration status, and in the presence of either ferrous or ferric iron. The specific rates of ferric iron reduction by fermenter-grown Acidiphilium SJH were unaffected by dissolved oxygen (DO) concentrations, while iron reduction by A. acidophilum was highly dependent on DO concentrations in the growth media. The ionic form of iron present (ferrous or ferric) had a minimal effect on the abilities of harvested cells to reduce ferric iron. Whole cell protein profiles of Acidiphilium SJH were very similar, regardless of the DO status of the growth medium, while additional proteins were present in A. acidophilum grown microaerobically compared with aerobically-grown cells. The dissimilatory reduction of ferric iron is constitutive in Acidiphilium SJH while it is inducible in A. acidophilum. Ferric iron reduction by Acidiphilium spp. may occur in oxygen-containing as well as anoxic acidic environments. This will detract from the effectiveness of bioremediation systems where removal of iron from polluted waters is mediated via oxidation and precipitation of the metal.

Multiplexed, high density electrophysiology with nanofabricated neural probes.

Directory of Open Access Journals (Sweden)

Jiangang Du

Full Text Available Extracellular electrode arrays can reveal the neuronal network correlates of behavior with single-cell, single-spike, and sub-millisecond resolution. However, implantable electrodes are inherently invasive, and efforts to scale up the number and density of recording sites must compromise on device size in order to connect the electrodes. Here, we report on silicon-based neural probes employing nanofabricated, high-density electrical leads. Furthermore, we address the challenge of reading out multichannel data with an application-specific integrated circuit (ASIC performing signal amplification, band-pass filtering, and multiplexing functions. We demonstrate high spatial resolution extracellular measurements with a fully integrated, low noise 64-channel system weighing just 330 mg. The on-chip multiplexers make possible recordings with substantially fewer external wires than the number of input channels. By combining nanofabricated probes with ASICs we have implemented a system for performing large-scale, high-density electrophysiology in small, freely behaving animals that is both minimally invasive and highly scalable.

Removal of some heavy metals from industrial waste water using polyacrylamide ferric antimonate as new ion exchange material

International Nuclear Information System (INIS)

El-Aryan, Y.F.A.

2011-01-01

Composite ion exchangers consist of one or more ion exchangers combined with another material, which can be inorganic or organic and may it be an ion exchanger. The reason for manufacturing a composite material is to produce a granular material, with sufficient strength for column use, from ion exchangers that do not form, or only form weak, granules themselves. Attempts in this study are focused to prepare composite ion exchangers for treatment of wastewater. Heavy metals when present in water in concentrations exceeding the permitted limits are injurious to the health. Hence, it is very important to treat such waters to remove the metal ions present before it is supplied for any useful purpose. Therefore, many investigations have studied to develop more effective process to treat such waste stream. Ion-exchange has been widely adopted in heavy metal containing wastewater and most of the ion-exchangers (i.e. ion-exchange media) currently being used are commercially mass-produced organic resins.Therefore, the main aim of this work is directed to find the optimum conditions for removal of some heavy metals from industrial waste water.1-Preparation of polyacrylamide ferric antimonate composite.2-Characterization of the prepared exchanger using IR spectra, X-ray diffraction pattern, DTA and TG analyses.3-Chemical stability, capacity and equilibrium measurements will be determined on the materials using at different conditions (ph heating temperature and reaction temperature).4-Kinetic studies of some heavy metals.5-Ion exchange isotherm.6-Breakthrough curves for removal of the investigated metal ions on the prepared exchanger under certain condition.

Microchannel Reactors for ISRU Applications Using Nanofabricated Catalysts, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Makel Engineering, Inc. (MEI) and USRA propose to develop microchannel reactors for In-Situ Resources Utilization (ISRU) using nanofabricated catalysts. The proposed...

Ferric ion mediated photochemical decomposition of perfluorooctanoic acid (PFOA) by 254 nm UV light

International Nuclear Information System (INIS)

Wang Yuan; Zhang Pengyi; Pan Gang; Chen Hao

2008-01-01

The great enhancement of ferric ion on the photochemical decomposition of environmentally persistent perfluorooctanoic acid (PFOA) under 254 nm UV light was reported. In the presence of 10 μM ferric ion, 47.3% of initial PFOA (48 μM) was decomposed and the defluorination ratio reached 15.4% within 4 h reaction time. While the degradation and defluorination ratio greatly increased to 80.2% and 47.8%, respectively, when ferric ion concentration increased to 80 μM, and the corresponding half-life was shortened to 103 min. Though the decomposition rate was significantly lowered under nitrogen atmosphere, PFOA was efficiently decomposed too. Other metal ions like Cu 2+ and Zn 2+ also slightly improved the photochemical decomposition of PFOA under irradiation of 254 nm UV light. Besides fluoride ion, other intermediates during PFOA decomposition including formic acid and five shorter-chain perfluorinated carboxylic acids (PFCAs) with C7, C6, C5, C4 and C3, respectively, were identified and quantified by IC or LC/MS. The mixture of PFOA and ferric ion had strong absorption around 280 nm. It is proposed that PFOA coordinates with ferric ion to form a complex, and its excitation by 254 nm UV light leads to the decomposition of PFOA in a stepwise way

Heavy metal toxicity and iron chlorosis

Energy Technology Data Exchange (ETDEWEB)

DeKock, P C

1956-01-01

The toxicity of copper, nickel, cobalt, zinc, chromium, and manganese to mustard was studied in water culture, utilizing either the ionic form or the EDTA chelate of the metal in the presence of either ferric chloride or ferric EDTA. In presence of ferric chloride the activity of the metals in producing chlorosis was as given above, i.e. in the order of stability of their chelates. In the presence of ferric versenate, toxicity of the ionic metal was much reduced. The metal chelates gave very little indication of toxicity with either form of iron. It was found that the ratio of total phosphorus to total iron was higher in chlorotic plants than in green plants, irrespective of which metal was causing the toxicity. Copper could be demonstrated in the phloem cells of the root using biscyclohexanone-oxalydihydrazone as histochemical reagent. It is postulated that transport of iron probably takes place in the phloem as an active process. It would appear that as a major part of the iron in plant cells is attached to nucleo- or phospho-proteins, the heavy metals must be similarly attached to phospho-proteins.

Industrial applications of micro/nanofabrication at Singapore Synchrotron Light Source

International Nuclear Information System (INIS)

Jian, L K; Casse, B D F; Heussler, S P; Kong, J R; Saw, B T; Mahmood, Shahrain bin; Moser, H O

2006-01-01

SSLS (Singapore Synchrotron Light Source) has set up a complete one-stop shop for micro/nanofabrication in the framework of the LIGA process. It is dubbed LiMiNT for Lithography for Micro and Nanotechnology and allows complete prototyping using the integral cycle of the LIGA process for producing micro/nanostructures from mask design/fabrication over X-ray lithography to electroplating in Ni, Cu, or Au, and, finally, hot embossing in a wide variety of plastics as one of the capabilities to cover a wide range of application fields and to go into higher volume production. The process chain also includes plasma cleaning and sputtering as well as substrate preparation processes including metal buffer layers, plating bases, and spin coating, polishing, and dicing. Furthermore, metrology using scanning electron microscopy (SEM), optical profilometry, and optical microscopy is available. LiMiNT is run as a research lab as well as a foundry. In this paper, several industrial applications will be presented, in which LiMiNT functions as a foundry to provide external customers the micro/nano fabrication services. These services include the fabrication of optical or X-ray masks, of micro/nano structures from polymers or from metals and of moulds for hot embossing or injection moulding

A nanofabricated, monolithic, path-separated electron interferometer

OpenAIRE

Agarwal, Akshay; Kim, Chung-Soo; Hobbs, Richard; Dyck, Dirk van; Berggren, Karl K.

2017-01-01

Progress in nanofabrication technology has enabled the development of numerous electron optic elements for enhancing image contrast and manipulating electron wave functions. Here, we describe a modular, self-aligned, amplitude-division electron interferometer in a conventional transmission electron microscope. The interferometer consists of two 45-nm-thick silicon layers separated by 20??m. This interferometer is fabricated from a single-crystal silicon cantilever on a transmission electron m...

Nanofabrication Technology for Production of Quantum Nano-Electronic Devices Integrating Niobium Electrodes and Optically Transparent Gates

Science.gov (United States)

2018-01-01

TECHNICAL REPORT 3086 January 2018 Nanofabrication Technology for Production of Quantum Nano-electronic Devices Integrating Niobium Electrodes...work described in this report was performed for the by the Advanced Concepts and Applied Research Branch (Code 71730) and the Science and Technology ...Applied Sciences Division iii EXECUTIVE SUMMARY This technical report demonstrates nanofabrication technology for Niobium heterostructures and

Large-scale nanofabrication of periodic nanostructures using nanosphere-related techniques for green technology applications (Conference Presentation)

Science.gov (United States)

Yen, Chen-Chung; Wu, Jyun-De; Chien, Yi-Hsin; Wang, Chang-Han; Liu, Chi-Ching; Ku, Chen-Ta; Chen, Yen-Jon; Chou, Meng-Cheng; Chang, Yun-Chorng

2016-09-01

Nanotechnology has been developed for decades and many interesting optical properties have been demonstrated. However, the major hurdle for the further development of nanotechnology depends on finding economic ways to fabricate such nanostructures in large-scale. Here, we demonstrate how to achieve low-cost fabrication using nanosphere-related techniques, such as Nanosphere Lithography (NSL) and Nanospherical-Lens Lithography (NLL). NSL is a low-cost nano-fabrication technique that has the ability to fabricate nano-triangle arrays that cover a very large area. NLL is a very similar technique that uses polystyrene nanospheres to focus the incoming ultraviolet light and exposure the underlying photoresist (PR) layer. PR hole arrays form after developing. Metal nanodisk arrays can be fabricated following metal evaporation and lifting-off processes. Nanodisk or nano-ellipse arrays with various sizes and aspect ratios are routinely fabricated in our research group. We also demonstrate we can fabricate more complicated nanostructures, such as nanodisk oligomers, by combining several other key technologies such as angled exposure and deposition, we can modify these methods to obtain various metallic nanostructures. The metallic structures are of high fidelity and in large scale. The metallic nanostructures can be transformed into semiconductor nanostructures and be used in several green technology applications.

Engineering metallic nanostructures for plasmonics and nanophotonics

Science.gov (United States)

Lindquist, Nathan C.; Nagpal, Prashant; McPeak, Kevin M.; Norris, David J.; Oh, Sang-Hyun

2012-03-01

Metallic nanostructures now play an important role in many applications. In particular, for the emerging fields of plasmonics and nanophotonics, the ability to engineer metals on nanometric scales allows the development of new devices and the study of exciting physics. This review focuses on top-down nanofabrication techniques for engineering metallic nanostructures, along with computational and experimental characterization techniques. A variety of current and emerging applications are also covered.

Process for making rare earth metal chlorides

International Nuclear Information System (INIS)

Kruesi, P.R.

1981-01-01

An uncombined metal or a metal compound such as a sulfide, oxide, carbonate or sulfate is converted in a liquid salt bath to the corresponding metal chloride by reacting it with chlorine gas or a chlorine donor. The process applies to metals of groups 1b, 2a, 2b, 3a, 3b, 4a, 5a and 8 of the periodic table and to the rare earth metals. The chlorine donor may be ferric or sulfur chloride. The liquid fused salt bath is made up of chlorides of alkali metals, alkaline earth metals, ammonia, zinc and ferric iron. Because the formed metal chlorides are soluble in the liquid fused salt bath, they can be recovered by various conventional means

Development of nano-fabrication technique utilizing self-organizational behavior of point defects induced by ion irradiation

Energy Technology Data Exchange (ETDEWEB)

Nitta, Noriko [Department of Environmental Systems Engineering, Kochi University of Technology, Tosayamada-Cho, Kochi-Prefecture 782-8502 (Japan); Taniwaki, Masafumi [Department of Environmental Systems Engineering, Kochi University of Technology, Tosayamada-Cho, Kochi-Prefecture 782-8502 (Japan)]. E-mail: taniwaki.masafumi@kochi-tech.ac.jp

2006-04-01

The present authors proposed a novel nano-fabrication technique that is able to arrange the fine cells orderly, based on their finding in GaSb implanted at a low temperature. In this article, first the experimental results that anomalous cellular structure was formed in GaSb by ion implantation is introduced and the self-organizational formation mechanism of the structure is described. Next a nano-fabrication technique that utilizes focused ion beam is described. This technique consists of two procedures, i.e. the formation process of the voids array and the development of the initial array to ordered cellular structure. Finally, the nano-fabrication is actually performed by this technique and their results are reported. Fabrication succeeded in structures where the dot (cell) interval was 100 nm or larger. The minimum ion dose for initial voids which develops to the ordered cellular structure is evaluated. It is also shown that the substrate temperature during implantation is an essential parameter for this technique.

Development of nano-fabrication technique utilizing self-organizational behavior of point defects induced by ion irradiation

International Nuclear Information System (INIS)

Nitta, Noriko; Taniwaki, Masafumi

2006-01-01

The present authors proposed a novel nano-fabrication technique that is able to arrange the fine cells orderly, based on their finding in GaSb implanted at a low temperature. In this article, first the experimental results that anomalous cellular structure was formed in GaSb by ion implantation is introduced and the self-organizational formation mechanism of the structure is described. Next a nano-fabrication technique that utilizes focused ion beam is described. This technique consists of two procedures, i.e. the formation process of the voids array and the development of the initial array to ordered cellular structure. Finally, the nano-fabrication is actually performed by this technique and their results are reported. Fabrication succeeded in structures where the dot (cell) interval was 100 nm or larger. The minimum ion dose for initial voids which develops to the ordered cellular structure is evaluated. It is also shown that the substrate temperature during implantation is an essential parameter for this technique

STUDY OF UREMIC TOXIN FLUXES ACROSS NANOFABRICATED HEMODIALYSIS MEMBRANES USING IRREVERSIBLE THERMODYNAMICS

Directory of Open Access Journals (Sweden)

Assem Hedayat

2013-03-01

Conclusions: Nanofabricated hemodialysis membranes with a reduced thickness and an applied electric potential can enhance the effective diffusivity and electro-migration flux of the respective uremic toxins by 3 orders of magnitude as compared to those passing through the high flux hemodialyzer.

FERRIC CITRATE: AN IRON-BASED ORAL PHOSPHATE BINDER

Directory of Open Access Journals (Sweden)

T. Christopher Bond

2012-06-01

Based on actual physician behavior in response to ferritin and TSAT increases and ferric citrate clinical trial results, and assuming equivalent pricing to other PBs, there would be cost savings with ferric citrate use through reduced ESA and iron use.

Methods for recovering metals from electronic waste, and related systems

Science.gov (United States)

Lister, Tedd E; Parkman, Jacob A; Diaz Aldana, Luis A; Clark, Gemma; Dufek, Eric J; Keller, Philip

2017-10-03

A method of recovering metals from electronic waste comprises providing a powder comprising electronic waste in at least a first reactor and a second reactor and providing an electrolyte comprising at least ferric ions in an electrochemical cell in fluid communication with the first reactor and the second reactor. The method further includes contacting the powders within the first reactor and the second reactor with the electrolyte to dissolve at least one base metal from each reactor into the electrolyte and reduce at least some of the ferric ions to ferrous ions. The ferrous ions are oxidized at an anode of the electrochemical cell to regenerate the ferric ions. The powder within the second reactor comprises a higher weight percent of the at least one base metal than the powder in the first reactor. Additional methods of recovering metals from electronic waste are also described, as well as an apparatus of recovering metals from electronic waste.

Nanofabrication of Plasmonic Circuits Containing Single Photon Sources

DEFF Research Database (Denmark)

Siampour, Hamidreza; Kumar, Shailesh; Bozhevolnyi, Sergey I.

2017-01-01

Nanofabrication of photonic components based on dielectric loaded surface plasmon polariton waveguides (DLSPPWs) excited by single nitrogen vacancy (NV) centers in nanodiamonds is demonstrated. DLSPPW circuits are built around NV containing nanodiamonds, which are certified to be single-photon...... emitters, using electron-beam lithography of hydrogen silsesquioxane (HSQ) resist on silver-coated silicon substrates. A propagation length of 20 ± 5 μm for the NV single-photon emission is measured with DLSPPWs. A 5-fold enhancement in the total decay rate, and 58% coupling efficiency to the DLSPPW mode...

Intravenous ferric carboxymaltose for anaemia in pregnancy.

Science.gov (United States)

Froessler, Bernd; Collingwood, Joshua; Hodyl, Nicolette A; Dekker, Gustaaf

2014-03-25

Iron deficiency is a common nutritional deficiency amongst women of childbearing age. Peri-partum iron deficiency anaemia (IDA) is associated with significant maternal, fetal and infant morbidity. Current options for treatment are limited: these include oral iron supplementation, which can be ineffective and poorly tolerated, and red blood cell transfusions, which carry an inherent risk and should be avoided. Ferric carboxymaltose is a new treatment option that may be better tolerated.The study was designed to assess the safety and efficacy of iron deficiency anaemia (IDA) correction with intravenous ferric carboxymaltose in pregnant women with mild, moderate and severe anaemia in the second and third trimester. Prospective observational study; 65 anaemic pregnant women received ferric carboxymaltose up to 15 mg/kg between 24 and 40 weeks of pregnancy (median 35 weeks gestational age, SD 3.6). Treatment effectiveness was assessed by repeat haemoglobin (Hb) measurements and patient report of well-being in the postpartum period. Safety was assessed by analysis of adverse drug reactions and fetal heart rate monitoring during the infusion. Intravenous ferric carboxymaltose infusion significantly increased Hb values (p anaemia in pregnancy.

Transcriptional regulation by Ferric Uptake Regulator (Fur) in pathogenic bacteria.

Science.gov (United States)

Troxell, Bryan; Hassan, Hosni M

2013-01-01

In the ancient anaerobic environment, ferrous iron (Fe(2+)) was one of the first metal cofactors. Oxygenation of the ancient world challenged bacteria to acquire the insoluble ferric iron (Fe(3+)) and later to defend against reactive oxygen species (ROS) generated by the Fenton chemistry. To acquire Fe(3+), bacteria produce low-molecular weight compounds, known as siderophores, which have extremely high affinity for Fe(3+). However, during infection the host restricts iron from pathogens by producing iron- and siderophore-chelating proteins, by exporting iron from intracellular pathogen-containing compartments, and by limiting absorption of dietary iron. Ferric Uptake Regulator (Fur) is a transcription factor which utilizes Fe(2+) as a corepressor and represses siderophore synthesis in pathogens. Fur, directly or indirectly, controls expression of enzymes that protect against ROS damage. Thus, the challenges of iron homeostasis and defense against ROS are addressed via Fur. Although the role of Fur as a repressor is well-documented, emerging evidence demonstrates that Fur can function as an activator. Fur activation can occur through three distinct mechanisms (1) indirectly via small RNAs, (2) binding at cis regulatory elements that enhance recruitment of the RNA polymerase holoenzyme (RNAP), and (3) functioning as an antirepressor by removing or blocking DNA binding of a repressor of transcription. In addition, Fur homologs control defense against peroxide stress (PerR) and control uptake of other metals such as zinc (Zur) and manganese (Mur) in pathogenic bacteria. Fur family members are important for virulence within bacterial pathogens since mutants of fur, perR, or zur exhibit reduced virulence within numerous animal and plant models of infection. This review focuses on the breadth of Fur regulation in pathogenic bacteria.

Ferric sulfates on Mars: Surface Explorations and Laboratory Experiments

Science.gov (United States)

Wang, A.; Ling, Z.; Freeman, J. J.

2008-12-01

Recent results from missions to Mars have reinforced the importance of sulfates for Mars science. They are the hosts of water, the sinks of acidity, and maybe the most active species in the past and current surface/near-surface processes on Mars. Fe-sulfate was found frequently by Spirit and Opportunity rovers: jarosite in Meridiani Planum outcrops and a less specific "ferric sulfate" in the salty soils excavated by Spirit at Gusev Crater. Pancam spectral analysis suggests a variety of ferric sulfates in these soils, i.e. ferricopiapite, jarosite, fibroferrite, and rhomboclase. A change in the Pancam spectral features occurred in Tyrone soils after ~ 190 sols of exposure to surface conditions. Dehydration of ferric sulfate is a possible cause. We synthesized eight ferric sulfates and conducted a series of hydration/dehydration experiments. Our goal was to establish the stability fields and phase transition pathways of these ferric sulfates. In our experiments, water activity, temperature, and starting structure are the variables. No redox state change was observed. Acidic, neutral, and basic salts were used. Ferric sulfate sample containers were placed into relative humidity buffer solutions that maintain static relative humidity levels at three temperatures. The five starting phases were ferricopiapite (Fe4.67(SO4)6(OH)2.20H2O), kornelite (Fe2(SO4)3.7H2O), rhomboclase (FeH(SO4)2.4H2O), pentahydrite (Fe2(SO4)3.5H2O), and an amorphous phase (Fe2(SO4)3.5H2O). A total of one hundred fifty experiments have been running for nearly ten months. Thousands of coupled Raman and gravimetric measurements were made at intermediate steps to monitor the phase transitions. The first order discovery from these experiments is the extremely large stability field of ferricopiapite. Ferricopiapite is the major ferric sulfate to precipitate from a Fe3+-S-rich aqueous solution at mid-low temperature, and it has the highest H2O/Fe ratio (~ 4.3). However, unlike the Mg-sulfate with highest

Femtosecond laser three-dimensional micro- and nanofabrication

Energy Technology Data Exchange (ETDEWEB)

Sugioka, Koji, E-mail: ksugioka@riken.jp [RIKEN Center for Advanced Photonics, Hirosawa 2-1, Wako, Saitama 351-0198 (Japan); Cheng, Ya, E-mail: ya.cheng@siom.ac.cn [Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, P.O. Box 800-211, Shanghai 201800 (China)

2014-12-15

The rapid development of the femtosecond laser has revolutionized materials processing due to its unique characteristics of ultrashort pulse width and extremely high peak intensity. The short pulse width suppresses the formation of a heat-affected zone, which is vital for ultrahigh precision fabrication, whereas the high peak intensity allows nonlinear interactions such as multiphoton absorption and tunneling ionization to be induced in transparent materials, which provides versatility in terms of the materials that can be processed. More interestingly, irradiation with tightly focused femtosecond laser pulses inside transparent materials makes three-dimensional (3D) micro- and nanofabrication available due to efficient confinement of the nonlinear interactions within the focal volume. Additive manufacturing (stereolithography) based on multiphoton absorption (two-photon polymerization) enables the fabrication of 3D polymer micro- and nanostructures for photonic devices, micro- and nanomachines, and microfluidic devices, and has applications for biomedical and tissue engineering. Subtractive manufacturing based on internal modification and fabrication can realize the direct fabrication of 3D microfluidics, micromechanics, microelectronics, and photonic microcomponents in glass. These microcomponents can be easily integrated in a single glass microchip by a simple procedure using a femtosecond laser to realize more functional microdevices, such as optofluidics and integrated photonic microdevices. The highly localized multiphoton absorption of a tightly focused femtosecond laser in glass can also induce strong absorption only at the interface of two closely stacked glass substrates. Consequently, glass bonding can be performed based on fusion welding with femtosecond laser irradiation, which provides the potential for applications in electronics, optics, microelectromechanical systems, medical devices, microfluidic devices, and small satellites. This review paper

Microbial reduction of ferric iron oxyhydroxides as a way for remediation of grey forest soils heavily polluted with toxic metals by infiltration of acid mine drainage

Science.gov (United States)

Georgiev, Plamen; Groudev, Stoyan; Spasova, Irena; Nicolova, Marina

2015-04-01

The abandoned uranium mine Curilo is a permanent source of acid mine drainage (AMD) which steadily contaminated grey forest soils in the area. As a result, the soil pH was highly acidic and the concentration of copper, lead, arsenic, and uranium in the topsoil was higher than the relevant Maximum Admissible Concentration (MAC) for soils. The leaching test revealed that approximately half of each pollutant was presented as a reducible fraction as well as the ferric iron in horizon A was presented mainly as minerals with amorphous structure. So, the approach for remediation of the AMD-affected soils was based on the process of redoxolysis carried out by iron-reducing bacteria. Ferric iron hydroxides reduction and the heavy metals released into soil solutions was studied in the dependence on the source of organic (fresh or silage hay) which was used for growth and activity of soil microflora, initial soil pH (3.65; 4.2; and 5.1), and the ion content of irrigation solutions. The combination of limestone (2.0 g/ kg soil), silage addition (at rate of 45 g dry weight/ kg soil) in the beginning and reiterated at 6 month since the start of soil remediation, and periodical soil irrigation with slightly acidic solutions containing CaCl2 was sufficient the content of lead and arsenic in horizon A to be decreased to concentrations similar to the relevant MAC. The reducible, exchangeable, and carbonate mobile fractions were phases from which the pollutants was leached during the applied soil remediation. It determined the higher reduction of the pollutants bioavailability also as well as the process of ferric iron reduction was combined with neutralization of the soil acidity to pH (H2O) 6.2.

Nanofluidic channels of arbitrary shapes fabricated by tip-based nanofabrication

International Nuclear Information System (INIS)

Hu, Huan; Cunningham, Brian T; King, William P; Zhuo, Yue; Oruc, Muhammed E

2014-01-01

Nanofluidic channels have promising applications in biomolecule manipulation and sensing. While several different methods of fabrication have been demonstrated for nanofluidic channels, a rapid, low-cost fabrication method that can fabricate arbitrary shapes of nanofluidic channels is still in demand. Here, we report a tip-based nanofabrication (TBN) method for fabricating nanofluidic channels using a heated atomic force microscopy (AFM) tip. The heated AFM tip deposits polymer nanowires where needed to serve as etch mask to fabricate silicon molds through one step of etching. PDMS nanofluidic channels are easily fabricated through replicate molding using the silicon molds. Various shapes of nanofluidic channels with either straight or curvilinear features are demonstrated. The width of the nanofluidic channels is 500 nm, and is determined by the deposited polymer nanowire width. The height of the channel is 400 nm determined by the silicon etching time. Ion conductance measurement on one single curvy shaped nanofluidic channel exhibits the typical ion conductance saturation phenomenon as the ion concentration decreases. Moreover, fluorescence imaging of fluid flowing through a fabricated nanofluidic channel demonstrates the channel integrity. This TBN process is seamlessly compatible with existing nanofabrication processes and can be used to achieve new types of nanofluidic devices. (paper)

Superiority of ferric chloride as coagulant over alum and ferrous sulphate at controlled pH and cost comparison of these coagulant

International Nuclear Information System (INIS)

Irfan, M.

2008-01-01

This study was conducted by author as a member of Specialty Chemical Division of Sitara Chemical Industries which is the largest chlor -alkali manufacturing industry in Pakistan. Sitara is also producing FeCl/sub 3/ as a byproduct to consume its additional quantity of chlorine produced during electrolysis of brine solution for caustic soda preparation. Most of the industries are using Alum along with other polymers for treatment of effluent waste water. Treatment system is based on sand bed filters. For coagulation of unwanted materials present in the water, Alum is being used with Anionic Polymer (Accofloc-A2125) as flocculent. But the ferric chloride is not only functions as a reactants to remove water impurities but it also functions as a both coagulant and a Flocculent. This study was conducted for finding best alternative chemicals to improve treated water quality. For this purpose Ferric Chloride (FeCl/sub 3/) is used as best alternative of alum for better removal of turbidity, heavy metals and micro organisms to eradicate above said problems and for better removal of turbidity, heavy metals and micro, organisms to eradicate health problems. As per lab scale results quality of treated water with Ferric Chloride (FeCl/sub 3/) proved better than that of Alum. The main objective of this research is to investigate the efficiency of coagulation and flocculation processes for removing suspended solids, colour and COD which present in significant quantity. Three types of coagulants were examined using standard jar test apparatus, i.e., aluminum sulphate (alum), ferric chloride (FeCl/sub 3/) and ferrous sulphate (FeSO/sub 4/). The effects of agitation speed, settling time, pH, coagulant dosages and temperature were examined. At 300 rpm of rapid mixing and 50 rpm of slow mixing and 60 minutes settling time, higher removals of suspended solids (over 95%), colour (90%) and COD (43%) were achieved at pH 4 and 12. FeCl/sub 3/ was found to be superior compared with other

Surface plasmon microscopy with low-cost metallic nanostructures for biosensing I

Science.gov (United States)

Lindquist, Nathan; Oh, Sang-Hyun; Otto, Lauren

2012-02-01

The field of plasmonics aims to manipulate light over dimensions smaller than the optical wavelength by exploiting surface plasmon resonances in metallic films. Typically, surface plasmons are excited by illuminating metallic nanostructures. For meaningful research in this exciting area, the fabrication of high-quality nanostructures is critical, and in an undergraduate setting, low-cost methods are desirable. Careful optical characterization of the metallic nanostructures is also required. Here, we present the use of novel, inexpensive nanofabrication techniques and the development of a customized surface plasmon microscopy setup for interdisciplinary undergraduate experiments in biosensing, surface-enhanced Raman spectroscopy, and surface plasmon imaging. A Bethel undergraduate student performs the nanofabrication in collaboration with the University of Minnesota. The rewards of mentoring undergraduate students in cooperation with a large research university are numerous, exposing them to a wide variety of opportunities. This research also interacts with upper-level, open-ended laboratory projects, summer research, a semester-long senior research experience, and will enable a large range of experiments into the future.

Subsurface injection of dissolved ferric chloride to form a chemical barrier: Laboratory investigations

International Nuclear Information System (INIS)

Morrison, S.J.; Spangler, R.R.; Morris, S.A.

1996-01-01

A chemical barrier is a permeable zone of reactive materials emplaced in the subsurface to remove ground-water contaminants while allowing clean ground water to pass through. Because dissolved ferric chloride hydrolyzes to amorphous ferric oxyhydroxide when it contacts calcite (CaCO 3 ), it may be viable to emplace a zone of amorphous ferric oxyhydroxide (an absorbent for U, Mo, and other inorganic contaminants) into calcite-bearing geologic units by injecting ferric chloride through wells. For a chemical barrier to be successful, it must remain permeable and must be immobile. This investigation monitored chemical compositions, hydraulic conductivity, and iron mobility in laboratory columns and in a two-dimensional tank to determine the viability of injecting ferric chloride to form an amorphous ferric oxyhydroxide chemical barrier. The authors introduced a ferric chloride solution (1,345 mg/1[0.024 m] Fe) to calcite-bearing alluvial gravel to form a chemical barrier of amorphous ferric oxyhydroxide, followed by solutions contaminated with U and Mo. The simulated chemical barriers decreased U and Mo concentrations to less than 0.05 mg/l (2.1 x 10 -7 m) and 0.01 (1.0 x 10 -7 m), respectively; however, the breakthrough front is spread out with concentrations increasing to more than regulatory guideline values sooner than predicted. The hydraulic conductivity of calcite-bearing alluvial gravel decreased substantially during ferric chloride introduction because of the formation of carbon dioxide but increased to within factors of 1 to 5 of the original value as synthetic ground water flowed through the system. Amorphous ferric oxyhydroxide that formed in these experiments remained immobile at flow rates exceeding those typical of ground water. These laboratory results, in conjunction with site-specific characterization data, can be used to design chemical barriers emplaced by injection of ferric chloride

Photofunctional polyurethane nanofabrics doped by zinc tetraphenylporphyrin and zinc phthalocyanine photosensitizers

Czech Academy of Sciences Publication Activity Database

Mosinger, Jiří; Lang, Kamil; Kubát, Pavel; Sýkora, Jan; Hof, Martin; Plíštil, J.; Mosinger, B.

2009-01-01

Roč. 19, č. 4 (2009), s. 705-713 ISSN 1053-0509 R&D Projects: GA ČR GA203/08/0831; GA ČR GA203/07/1424; GA ČR(CZ) GA203/06/1244 Institutional research plan: CEZ:AV0Z40320502; CEZ:AV0Z40400503 Keywords : singlet oxygen * nanofabric * energy transfer Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.017, year: 2009

Ferric oxide quantum dots in stable phosphate glass system and their magneto-optical study

Energy Technology Data Exchange (ETDEWEB)

Garaje, Sunil N.; Apte, Sanjay K. [Nanocomposite Group, Centre for Materials for Electronics Technology (C-MET), Department of Electronics and Information Technology (DeitY), Government of India, Panchawati, Off Pashan Road, Pune 411008 (India); Kumar, Ganpathy [Department of Electrical and Computer Engineering, Tennessee Technological University, 1 William L. Jones Drive, Cookeville, TN 38505 (United States); Panmand, Rajendra P.; Naik, Sonali D. [Nanocomposite Group, Centre for Materials for Electronics Technology (C-MET), Department of Electronics and Information Technology (DeitY), Government of India, Panchawati, Off Pashan Road, Pune 411008 (India); Mahajan, Satish M., E-mail: smahajan@tntech.edu [Department of Electrical and Computer Engineering, Tennessee Technological University, 1 William L. Jones Drive, Cookeville, TN 38505 (United States); Chand, Ramesh [Ministry of Communications and Information Technology, Department of Electronics and Information Technology (DeitY), Electronics Niketan, 6, CGO Complex, New Delhi 110003 (India); Kale, Bharat B., E-mail: bbkale@cmet.gov.in [Nanocomposite Group, Centre for Materials for Electronics Technology (C-MET), Department of Electronics and Information Technology (DeitY), Government of India, Panchawati, Off Pashan Road, Pune 411008 (India)

2013-02-15

Graphical abstract: We report synthesis of ferric oxide embedded low melting phosphate glass nanocomposite and also the effect of ferric oxide nanoparticles (NCs) content on the optical and magneto-optical properties of the glasses. Faraday rotation of the glass nanocomposites was measured and showed variation in Verdet constant with concentration of ferric oxide. Interestingly, the host glass itself showed fairly good Verdet constant (11.5°/T cm) and there is a threefold enhancement in the Verdet constant of ferric oxide quantum dot-glass nanocomposite. Highlights: ► We synthesize ferric oxide embedded low melting stable phosphate glass nanocomposite. ► Glasses doped with 0.25 and 2% ferric oxide show particle size in the range of 4–12 nm. ► The host phosphate glass itself shows fairly good Verdet constant (11.5°/T cm). ► Glasses doped with 0.25% ferric oxide show high Verdet constant (30.525°/T cm). ► The as synthesis glasses may have potential application in magneto optical devices. -- Abstract: Herein, we report the synthesis of ferric oxide embedded low melting phosphate glass nanocomposite and also the effect of ferric oxide nanoparticles content on the optical and magneto-optical properties of the glasses. The optical study clearly showed red shift in optical cut off with increasing ferric oxide concentration. The band gap of the host glass was observed to be 3.48 eV and it shifted to 3.14 eV after doping with ferric oxide. The glasses doped with 0.25 and 2% ferric oxide showed particle size of 4–6 nm and 8–12 nm, respectively. Faraday rotation of the glass nanocomposites was measured and showed variation in the Verdet constant as per increasing concentration of ferric oxide. Interestingly, the host glass itself showed fairly good Verdet constant (11.5°/T cm) and threefold enhancement was observed in the Verdet constant of ferric oxide quantum dot-glass nanocomposite.

The absorption and transportation of ferric-salt in apple trees

International Nuclear Information System (INIS)

Xiong Zhixun; Chen Meihong

1994-01-01

59 Fe tracer technique was used to study the ferric-salt absorption, utilization and transportation in apple trees. The results indicated that absorption and utilization rate of ferric salt was 0.056%∼0.110% for roots and 30% for leaves, and that Fe is not easily to be transferred from one part to another. Fulvic acid iron had a better effect than ferrous sulfate. Ferric-salt absorption, utilization and transference were different among the cultivars. Intensive injections of ferrous salt into the apple trunks seemed to be more effective for correcting of chlorosis

Development of a radiochromic ferric oligomer hydrogel

International Nuclear Information System (INIS)

Jordan, Kevin; Sekimoto, Masaya

2010-01-01

Ferrous gelatin hydrogels were prepared by using sulphuric acid concentrations lower than required to maintain radiation induced ferric ions fully hydrated. The ferric hydroxyl species that are produced following irradiation exhibit a radiochromic response that can be probed with blue light. The dose distribution shapes were stable in time, indicating no long term diffusion. An over response to dose gradients was observed both in one centimeter cuvette samples and litre volumes probed with optical cone beam CT. This ferrous hydrogel may represent a model system for studying iron radiochemistry in biological systems.

From nanofabrication to self-fabrication--tailored chemistry for control of single molecule electronic devices

DEFF Research Database (Denmark)

Moth-Poulsen, Kasper; Bjørnholm, Thomas

2010-01-01

as alternatives to the dominant top-down nanofabrication techniques. One example is solution-based self-assembly of a molecule enclosed by two gold nanorod electrodes. This article will discuss recent attempts to control the self-assembly process by the use of supramolecular chemistry and how to tailor...

X-ray lithography for micro- and nano-fabrication at ELETTRA for interdisciplinary applications

International Nuclear Information System (INIS)

Di Fabrizio, E; Fillipo, R; Cabrini, S

2004-01-01

ELETTRA (http://www.elettra.trieste.it/index.html) is a third generation synchrotron radiation source facility operating at Trieste, Italy, and hosts a wide range of research activities in advanced materials analysis and processing, biology and nano-science at several various beam lines. The energy spectrum of ELETTRA allows x-ray nano-lithography using soft (1.5 keV) and hard x-ray (10 keV) wavelengths. The Laboratory for Interdisciplinary Lithography (LIILIT) was established in 1998 as part of an Italian national initiative on micro- and nano-technology project of INFM and is funded and supported by the Italian National Research Council (CNR), INFM and ELETTRA. LILIT had developed two dedicated lithographic beam lines for soft (1.5 keV) and hard x-ray (10 keV) for micro- and nano-fabrication activities for their applications in engineering, science and bio-medical applications. In this paper, we present a summary of our research activities in micro- and nano-fabrication involving x-ray nanolithography at LILIT's soft and hard x-ray beam lines

Compact Submillimeter-Wave Receivers Made with Semiconductor Nano-Fabrication Technologies

Science.gov (United States)

Jung, C.; Thomas, B.; Lee, C.; Peralta, A.; Chattopadhyay, G.; Gill, J.; Cooper, K.; Mehdi, I.

2011-01-01

Advanced semiconductor nanofabrication techniques are utilized to design, fabricate and demonstrate a super-compact, low-mass (<10 grams) submillimeter-wave heterodyne front-end. RF elements such as waveguides and channels are fabricated in a silicon wafer substrate using deep-reactive ion etching (DRIE). Etched patterns with sidewalls angles controlled with 1 deg precision are reported, while maintaining a surface roughness of better than 20 nm rms for the etched structures. This approach is being developed to build compact 2-D imaging arrays in the THz frequency range.

Mercury (II) reduction and co-precipitation of metallic mercury on hydrous ferric oxide in contaminated groundwater.

Science.gov (United States)

Richard, Jan-Helge; Bischoff, Cornelia; Ahrens, Christian G M; Biester, Harald

2016-01-01

Mercury (Hg) speciation and sorption analyses in contaminated aquifers are useful for understanding transformation, retention, and mobility of Hg in groundwater. In most aquifers hydrous ferric oxides (HFOs) are among the most important sorbents for trace metals; however, their role in sorption or mobilization of Hg in aquifers has been rarely analyzed. In this study, we investigated Hg chemistry and Hg sorption to HFO under changing redox conditions in a highly HgCl2-contaminated aquifer (up to 870μgL(-1) Hg). Results from aqueous and solid phase Hg measurements were compared to modeled (PHREEQC) data. Speciation analyses of dissolved mercury indicated that Hg(II) forms were reduced to Hg(0) under anoxic conditions, and adsorbed to or co-precipitated with HFO. Solid phase Hg thermo-desorption measurements revealed that between 55 and 93% of Hg bound to HFO was elemental Hg (Hg(0)). Hg concentrations in precipitates reached more than 4 weight %, up to 7000 times higher than predicted by geochemical models that do not consider unspecific sorption to and co-precipitation of elemental Hg with HFO. The observed process of Hg(II) reduction and Hg(0) formation, and its retention and co-precipitation by HFO is thought to be crucial in HgCl2-contaminated aquifers with variable redox-conditions regarding the related decrease in Hg solubility (factor of ~10(6)), and retention of Hg in the aquifer. Copyright © 2015 Elsevier B.V. All rights reserved.

Pyrolysis of the mixture of MSWI fly ash and sewage sludge for co-disposal: Effect of ferrous/ferric sulfate additives.

Science.gov (United States)

Hu, Yuyan; Yang, Fan; Chen, Fangfang; Feng, Yuheng; Chen, Dezhen; Dai, Xiaohu

2018-05-01

Co-pyrolysis with sewage sludge was proved to be an efficient pre-treatment for sanitary landfill of municipal solid waste incineration (MSWI) fly ash (FA). In this study, to improve the stabilization effect of heavy metals, mixed ferrous/ferric sulfate was added into the FA/SS mixture before pyrolysis. To examine the feasibility of the landfill of co-pyrolysis char, toxicity characteristic leaching procedure (HJ/T300) was conducted. In addition, physio-chemical characteristics of char were also tested to explain the stability of heavy metals, including the speciation, mineralogical composition and the morphological features of them. The results indicated that within the range that the obtained char could meet the standard for landfill (GB16889-2008), the appropriate addition of mixed ferrous/ferric sulfates benefit to raising the FA ratio in the FA/SS mixture. The maximum ratio of 67 wt% is achieved when the additive was 1.5 wt% of dried SS (based on iron element) and the pyrolysis temperature was 500 °C. Copyright © 2018 Elsevier Ltd. All rights reserved.

Engineering Metal Nanostructure for SERS Application

Directory of Open Access Journals (Sweden)

Yanqin Cao

2013-01-01

Full Text Available Surface-enhanced Raman scattering (SERS has attracted great attention due to its remarkable enhancement and excellent selectivity in the detection of various molecules. Noble metal nanomaterials have usually been employed for producing substrates that can be used in SERS because of their unique local plasma resonance. As the SERS enhancement of signals depends on parameters such as size, shape, morphology, arrangement, and dielectric environment of the nanostructure, there have been a number of studies on tunable nanofabrication and synthesis of noble metals. In this work, we will illustrate progress in engineering metallic nanostructures with various morphologies using versatile methods. We also discuss their SERS applications in different fields and the challenges.

Enhancing phosphorus release from waste activated sludge containing ferric or aluminum phosphates by EDTA addition during anaerobic fermentation process.

Science.gov (United States)

Zou, Jinte; Zhang, Lili; Wang, Lin; Li, Yongmei

2017-03-01

The effect of ethylene diamine tetraacetic acid (EDTA) addition on phosphorus release from biosolids and phosphate precipitates during anaerobic fermentation was investigated. Meanwhile, the impact of EDTA addition on the anaerobic fermentation process was revealed. The results indicate that EDTA addition significantly enhanced the release of phosphorus from biosolids, ferric phosphate precipitate and aluminum phosphate precipitate during anaerobic fermentation, which is attributed to the complexation of metal ions and damage of cell membrane caused by EDTA. With the optimal EDTA addition of 19.5 mM (0.41 gEDTA/gSS), phosphorus release efficiency from biosolids was 82%, which was much higher than that (40%) without EDTA addition. Meanwhile, with 19.5 mM EDTA addition, almost all the phosphorus in ferric phosphate precipitate was released, while only 57% of phosphorus in aluminum phosphate precipitate was released. This indicates that phosphorus in ferric phosphate precipitate was much easier to be released than that in aluminum phosphate precipitate during anaerobic fermentation of sludge. In addition, proper EDTA addition facilitated the production of soluble total organic carbon and volatile fatty acids, as well as solid reduction during sludge fermentation, although methane production could be inhibited. Therefore, EDTA addition can be used as an alternative method for recovering phosphorus from waste activated sludge containing ferric or aluminum precipitates, as well as recovery of soluble carbon source. Copyright © 2016 Elsevier Ltd. All rights reserved.

Real-time nanofabrication with high-speed atomic force microscopy

International Nuclear Information System (INIS)

Vicary, J A; Miles, M J

2009-01-01

The ability to follow nanoscale processes in real-time has obvious benefits for the future of material science. In particular, the ability to evaluate the success of fabrication processes in situ would be an advantage for many in the semiconductor industry. We report on the application of a previously described high-speed atomic force microscope (AFM) for nanofabrication. The specific fabrication method presented here concerns the modification of a silicon surface by locally oxidizing the region in the vicinity of the AFM tip. Oxide features were fabricated during imaging, with relative tip-sample velocities of up to 10 cm s -1 , and with a data capture rate of 15 fps.

Gas-phase spectroscopy of ferric heme-NO complexes

DEFF Research Database (Denmark)

Wyer, J.A.; Jørgensen, Anders; Pedersen, Bjarke

2013-01-01

and significantly blue-shifted compared to ferric heme nitrosyl proteins (maxima between 408 and 422 nm). This is in stark contrast to the Q-band absorption where the protein microenvironment is nearly innocent in perturbing the electronic structure of the porphyrin macrocycle. Photodissociation is primarily...... maxima of heme and its complexes with amino acids and NO. Not so innocent: Weakly bound complexes between ferric heme and NO were synthesised in the gas phase, and their absorption measured from photodissociation yields. Opposite absorption trends in the Soret-band are seen upon NO addition to heme ions...

STUDY ON SOFTENING AND DROPPING PROPERTIES OF METALIZED BURDEN INSIDE BLAST FURNACE

Directory of Open Access Journals (Sweden)

Bi-yang Tuo

2014-12-01

Full Text Available The inferences of burden metallization rate on softening-melting dropping properties were investigated through softening-melting dropping test of three kinds of metalized burden pressure drop. The results indicated that the softeningmelting temperature interval of pre-reduction mixed burden is bigger than primeval mixed burden, the melting interval narrow with the rise of metallization rate of ferric burden as well as dropping temperature interval. The average pressure drop, maximum pressure drop and softening-melting dropping properties eigenvalue decrease with the rise of metallization rate of ferric burden. Besides, the dropping temperature of burden reduces with the rise of carbon content of molten iron. The combination high metalized burden and higher carbon content of molten iron is benefit to decreasing thickness of cohesive zone and improve permeability of cohesive zone.

Nanofabrication and Nanopatterning of Carbon Nanomaterials for Flexible Electronics

Science.gov (United States)

Ding, Junjun

Stretchable electrodes have increasingly drawn attention as a vital component for flexible electronic devices. Carbon nanomaterials such as graphene and carbon nanotubes (CNTs) exhibit properties such as high mechanical flexibility and strength, optical transparency, and electrical conductivity which are naturally required for stretchable electrodes. Graphene growth, nanopatterning, and transfer processes are important steps to use graphene as flexible electrodes. However, advances in the large-area nanofabrication and nanopatterning of carbon nanomaterials such as graphene are necessary to realize the full potential of this technology. In particular, laser interference lithography (LIL), a fast and low cost large-area nanoscale patterning technique, shows tremendous promise for the patterning of graphene and other nanostructures for numerous applications. First, it was demonstrated that large-area nanopatterning and the transfer of chemical vapor deposition (CVD) grown graphene via LIL and plasma etching provide a reliable method to provide large area nanoengineered graphene on various target substrates. Then, to improve the electrode performance under large strain (naturally CVD grown graphene sheet will crack at tensile strains larger than 1%), a corrugated graphene structure on PDMS was designed, fabricated, and tested, with experimental results indicating that this approach successfully allows the graphene sheets to withstand cyclic tensile strains up to 15%. Lastly, to further enhance the performance of carbon-based stretchable electrodes, an approach was developed which coupled graphene and vertically aligned CNT (VACNT) on a flexible PDMS substrate. Characterization of the graphene-VACNT hybrid shows high electrical conductivity and durability through 50 cycles of loading up to 100% tensile strain. While flexible electronics promise tremendous advances in important technological areas such as healthcare, sensing, energy, and wearable electronics, continued

Dissolution of Fe(III) (hydr) oxides by metal-EDTA complexes

Science.gov (United States)

Ngwack, Bernd; Sigg, Laura

1997-03-01

The dissolution of Fe(III)(hydr)oxides (goethite and hydrous ferric oxide) by metal-EDTA complexes occurs by ligand-promoted dissolution. The process is initiated by the adsorption of metal-EDTA complexes to the surface and is followed by the dissociation of the complex at the surface and the release of Fe(III)EDTA into solution. The dissolution rate is decreased to a great extent if EDTA is complexed by metals in comparison to the uncomplexed EDTA. The rate decreases in the order EDTA CaEDTA ≫ PbEDTA > ZnEDTA > CuEDTA > Co(II)EDTA > NiEDTA. Two different rate-limiting steps determine the dissolution process: (1) detachment of Fe(III) from the oxide-structure and (2) dissociation of the metal-EDTA complexes. In the case of goethite, step 1 is slower than step 2 and the dissolution rates by various metals are similar. In the case of hydrous ferric oxide, step 2 is rate-limiting and the effect of the complexed metal is very pronounced.

Modeling of ferric sulfate decomposition and sulfation of potassium chloride during grate‐firing of biomass

DEFF Research Database (Denmark)

Wu, Hao; Jespersen, Jacob Boll; Jappe Frandsen, Flemming

2013-01-01

Ferric sulfate is used as an additive in biomass combustion to convert the released potassium chloride to the less harmful potassium sulfate. The decomposition of ferric sulfate is studied in a fast heating rate thermogravimetric analyzer and a volumetric reaction model is proposed to describe...... the process. The yields of sulfur oxides from ferric sulfate decomposition under boiler conditions are investigated experimentally, revealing a distribution of approximately 40% SO3 and 60% SO2. The ferric sulfate decomposition model is combined with a detailed kinetic model of gas‐phase KCl sulfation...... and a model of K2SO4 condensation to simulate the sulfation of KCl by ferric sulfate addition. The simulation results show good agreements with experiments conducted in a biomass grate‐firing reactor. The results indicate that the SO3 released from ferric sulfate decomposition is the main contributor to KCl...

Electrical conduction studies in ferric-doped KHSO 4 single crystals

Science.gov (United States)

Sharon, M.; Kalia, A. K.

1980-03-01

Direct-current conductivity of ferric-doped (138, 267, and 490 ppm) single crystals of KHSO 4 has been studied. The mechanism for the dc conduction process is discussed. It is observed that the ferric ion forms a (Fe 3+-two vacancies) complex and the enthaply for its formation is 0.09 ± 0.01 eV. It is proposed that each ferric ion removes two protons from each HSO 4 dimer. The conductivity plot shows the presence of intrinsic and extrinsic regions. It is proposed that in the intrinsic region the dimer of HSO -4 breaks reversibly to form a long-chain monomer-type structure. The conductivity in the KHSO 4 crystal is proposed to be controlled by the rotation of HSO -4 tetrahedra along the axis which contains no hydrogen atom. Isotherm calculation for the trivalent-doped system is applied to this crystal and the results are compared with Co 2+-doped KHSO 4 crystal. The distribution coefficient of ferric ion in the KHSO 4 single crystal is calculated to be 4.5 × 10 -1. Ferric ion causes tapering in the crystal growth habit of KHSO 4 and it is believed to be due to the presence of (Fe 3+-two vacancies) complex. The enthalpy values for the various other processes are as follows: enthalpy for the breakage of HSO -4 dimer ( Hi) = 1.28 ± 0.01 eV; enthalpy for the rotation of HSO -4 tetrahedron ( Hm) = 0.58 ± 0.01 eV.

Nanofabricated racks of aligned and anchored DNA substrates for single-molecule imaging.

Science.gov (United States)

Gorman, Jason; Fazio, Teresa; Wang, Feng; Wind, Shalom; Greene, Eric C

2010-01-19

Single-molecule studies of biological macromolecules can benefit from new experimental platforms that facilitate experimental design and data acquisition. Here we develop new strategies to construct curtains of DNA in which the molecules are aligned with respect to one another and maintained in an extended configuration by anchoring both ends of the DNA to the surface of a microfluidic sample chamber that is otherwise coated with an inert lipid bilayer. This "double-tethered" DNA substrate configuration is established through the use of nanofabricated rack patterns comprised of two distinct functional elements: linear barriers to lipid diffusion that align DNA molecules anchored by one end to the bilayer and antibody-coated pentagons that provide immobile anchor points for the opposite ends of the DNA. These devices enable the alignment and anchoring of thousands of individual DNA molecules, which can then be visualized using total internal reflection fluorescence microscopy under conditions that do not require continuous application of buffer flow to stretch the DNA. This unique strategy offers the potential for studying protein-DNA interactions on large DNA substrates without compromising measurements through application of hydrodynamic force. We provide a proof-of-principle demonstration that double-tethered DNA curtains made with nanofabricated rack patterns can be used in a one-dimensional diffusion assay that monitors the motion of quantum dot-tagged proteins along DNA.

Effect of three Electron Shuttles on Bioreduction of Ferric Iron in two Acidic and Calcareous soils

Directory of Open Access Journals (Sweden)

Setareh Sharifi

2017-01-01

.54 when P. aeruginosa was added. The acid extractable iron was 3.90 mg g-1 in the presence of AQS and Shewanella sp. By adding P. aeruginosa, acid extractable iron was 2.84 mg g-1 compared to control treatments. Conclusions: Dissimilatory ferric iron reduction is a potentially important process in controlling contaminant fate. It has the potential for being particularly useful in the remediation of metals and radionuclides. Means for stimulating ferric iron reduction will be useful in enhancing bioremediation process. Results illustrated that the Shewanella sp. and P. aeruginosa were enhanced the bioreduction of ferric iron in the presence of AQS, humic acid and fulvic acid in soils. When soil samples were inoculated with Shewanella sp., and AQS was added to the soil samples (in acidic and calcareous soil samples the concentration of ferrous iron increased intensively.

[Stabilization of Cadmium Contaminated Soils by Ferric Ion Modified Attapulgite (Fe/ATP)--Characterizations and Stabilization Mechanism].

Science.gov (United States)

Rong, Yang; Li, Rong-bo; Zhou, Yong-li; Chen, Jing; Wang, Lin-ling; Lu, Xiao-hua

2015-08-01

Ferric ion modified attapulgite (Fe/ATP) was prepared by impregnation and its structure and morphology were characterized. The toxicity characteristic leaching procedure (TCLP) was used to evaluate the effect of Cadmium( Cd) stabilization in soil with the addition of attapulgite (ATP) and Fe/ATP. The stabilization mechanism of Cd was further elucidated by comparing the morphologies and structure of ATP and Fe/ATP before and after Cd adsorption. Fe/ATP exhibited much better adsorption capacity than ATP, suggesting different adsorption mechanisms occurred between ATP and Fe/ATP. The leaching concentrations of Cd in soil decreased by 45% and 91% respectively, with the addition of wt. 20% ATP and Fe/ATP. The former was attributed to the interaction between Cd2 and --OH groups by chemical binding to form inner-sphere complexes in ATP and the attachment between Cd2+ and the defect sites in ATP framework. Whereas Cd stabilization with Fe/ATP was resulted from the fact that the active centers (--OH bonds or O- sites) on ATP could react with Fe3+ giving Fe--O--Cd-- bridges, which helped stabilize Cd in surface soil. What'more, the ferric oxides and metal hydroxides on the surface of ATP could interact with Cd, probably by the formation of cadmium ferrite. In conclusion, Fe/ATP, which can be easily prepared, holds promise as a potential low-cost and environmental friendly stabilizing agent for remediation of soil contaminated with heavy metals.

Removal Of Heavy Metals From Industrial Wastewaters Using Local ...

African Journals Online (AJOL)

Wastewater samples from battery, paint and textile industries were treated with different doses of locally available alum, aluminum sulphate and ferric chloride in order to determine and compare their effectiveness in removing heavy metal contents from the wastewaters. The percentage removal of the metals from the ...

Single-molecule dynamics in nanofabricated traps

Science.gov (United States)

Cohen, Adam

2009-03-01

The Anti-Brownian Electrokinetic trap (ABEL trap) provides a means to immobilize a single fluorescent molecule in solution, without surface attachment chemistry. The ABEL trap works by tracking the Brownian motion of a single molecule, and applying feedback electric fields to induce an electrokinetic motion that approximately cancels the Brownian motion. We present a new design for the ABEL trap that allows smaller molecules to be trapped and more information to be extracted from the dynamics of a single molecule than was previously possible. In particular, we present strategies for extracting dynamically fluctuating mobilities and diffusion coefficients, as a means to probe dynamic changes in molecular charge and shape. If one trapped molecule is good, many trapped molecules are better. An array of single molecules in solution, each immobilized without surface attachment chemistry, provides an ideal test-bed for single-molecule analyses of intramolecular dynamics and intermolecular interactions. We present a technology for creating such an array, using a fused silica plate with nanofabricated dimples and a removable cover for sealing single molecules within the dimples. With this device one can watch the shape fluctuations of single molecules of DNA or study cooperative interactions in weakly associating protein complexes.

Comparative evaluation of microbial and chemical leaching processes for heavy metal removal from dewatered metal plating sludge

International Nuclear Information System (INIS)

Bayat, Belgin; Sari, Bulent

2010-01-01

The purpose of the study described in this paper was to evaluate the application of bioleaching technique involving Acidithiobacillus ferrooxidans to recover heavy metals (Zn, Cu, Ni, Pb, Cd and Cr) in dewatered metal plating sludge (with no sulfide or sulfate compounds). The effect of some conditional parameters (i.e. pH, oxidation-reduction potential (ORP), sulfate production) and operational parameters (i.e. pulp density of the sludge and agitation time) were investigated in a 3 l completely mixed batch (CMB) reactor. The metal recovery yields in bioleaching were also compared with chemical leaching of the sludge waste using commercial inorganic acids (sulfuric acids and ferric chloride). The leaching of heavy metals increased with decreasing of pH and increasing of ORP and sulfate production during the bioleaching experiment. Optimum pulp density for bioleaching was observed at 2% (w/v), and leaching efficiency decreased with increasing pulp density in bioleaching experiments. Maximum metal solubilization (97% of Zn, 96% of Cu, 93% of Ni, 84% of Pb, 67% of Cd and 34% of Cr) was achieved at pH 2, solids contents of 2% (w/v), and a reaction temperature of 25 ± 2 deg. C during the bioleaching process. The maximum removal efficiencies of 72% and 79% Zn, 70% and 75% Cu, 69% and 73% Ni, 57% and 70% Pb, 55% and 65% Cd, and 11% and 22% Cr were also attained with the chemical leaching using sulfuric acids and ferric chloride, respectively, at pH 2, solids contents of 2% (w/v), and a reaction temperature of 25 ± 2 deg. C during the acid leaching processes. The rates of metal leaching for bioleaching and chemical leaching are well described by a kinetic equation related to time. Although bioleaching generally requires a longer period of operation compared to chemical leaching, it achieves higher removal efficiency for heavy metals. The efficiency of leaching processes can be arranged in descending order as follows: bioleaching > ferric chloride leaching > sulfuric acid

Comparative evaluation of microbial and chemical leaching processes for heavy metal removal from dewatered metal plating sludge

Energy Technology Data Exchange (ETDEWEB)

Bayat, Belgin, E-mail: bbayat@cu.edu.tr [Department of Environmental Engineering, Faculty of Engineering and Architecture, Cukurova University, Balcali, Adana 01330 (Turkey); Sari, Bulent [Department of Environmental Engineering, Faculty of Engineering and Architecture, Cukurova University, Balcali, Adana 01330 (Turkey)

2010-02-15

The purpose of the study described in this paper was to evaluate the application of bioleaching technique involving Acidithiobacillus ferrooxidans to recover heavy metals (Zn, Cu, Ni, Pb, Cd and Cr) in dewatered metal plating sludge (with no sulfide or sulfate compounds). The effect of some conditional parameters (i.e. pH, oxidation-reduction potential (ORP), sulfate production) and operational parameters (i.e. pulp density of the sludge and agitation time) were investigated in a 3 l completely mixed batch (CMB) reactor. The metal recovery yields in bioleaching were also compared with chemical leaching of the sludge waste using commercial inorganic acids (sulfuric acids and ferric chloride). The leaching of heavy metals increased with decreasing of pH and increasing of ORP and sulfate production during the bioleaching experiment. Optimum pulp density for bioleaching was observed at 2% (w/v), and leaching efficiency decreased with increasing pulp density in bioleaching experiments. Maximum metal solubilization (97% of Zn, 96% of Cu, 93% of Ni, 84% of Pb, 67% of Cd and 34% of Cr) was achieved at pH 2, solids contents of 2% (w/v), and a reaction temperature of 25 {+-} 2 deg. C during the bioleaching process. The maximum removal efficiencies of 72% and 79% Zn, 70% and 75% Cu, 69% and 73% Ni, 57% and 70% Pb, 55% and 65% Cd, and 11% and 22% Cr were also attained with the chemical leaching using sulfuric acids and ferric chloride, respectively, at pH 2, solids contents of 2% (w/v), and a reaction temperature of 25 {+-} 2 deg. C during the acid leaching processes. The rates of metal leaching for bioleaching and chemical leaching are well described by a kinetic equation related to time. Although bioleaching generally requires a longer period of operation compared to chemical leaching, it achieves higher removal efficiency for heavy metals. The efficiency of leaching processes can be arranged in descending order as follows: bioleaching > ferric chloride leaching > sulfuric

Ferric-Pyoverdine Recognition by Fpv Outer Membrane Proteins of Pseudomonas protegens Pf-5

Science.gov (United States)

Hartney, Sierra L.; Mazurier, Sylvie; Girard, Maëva K.; Mehnaz, Samina; Davis, Edward W.; Gross, Harald; Lemanceau, Philippe

2013-01-01

The soil bacterium Pseudomonas protegens Pf-5 (previously called P. fluorescens Pf-5) produces two siderophores, enantio-pyochelin and a compound in the large and diverse pyoverdine family. Using high-resolution mass spectroscopy, we determined the structure of the pyoverdine produced by Pf-5. In addition to producing its own siderophores, Pf-5 also utilizes ferric complexes of some pyoverdines produced by other strains of Pseudomonas spp. as sources of iron. Previously, phylogenetic analysis of the 45 TonB-dependent outer membrane proteins in Pf-5 indicated that six are in a well-supported clade with ferric-pyoverdine receptors (Fpvs) from other Pseudomonas spp. We used a combination of phylogenetics, bioinformatics, mutagenesis, pyoverdine structural determinations, and cross-feeding bioassays to assign specific ferric-pyoverdine substrates to each of the six Fpvs of Pf-5. We identified at least one ferric-pyoverdine that was taken up by each of the six Fpvs of Pf-5. Functional redundancy of the Pf-5 Fpvs was also apparent, with some ferric-pyoverdines taken up by all mutants with a single Fpv deletion but not by a mutant having deletions in two of the Fpv-encoding genes. Finally, we demonstrated that phylogenetically related Fpvs take up ferric complexes of structurally related pyoverdines, thereby establishing structure-function relationships that can be employed in the future to predict the pyoverdine substrates of Fpvs in other Pseudomonas spp. PMID:23222724

Dense Plasma Focus-Based Nanofabrication of III-V Semiconductors: Unique Features and Recent Advances.

Science.gov (United States)

Mangla, Onkar; Roy, Savita; Ostrikov, Kostya Ken

2015-12-29

The hot and dense plasma formed in modified dense plasma focus (DPF) device has been used worldwide for the nanofabrication of several materials. In this paper, we summarize the fabrication of III-V semiconductor nanostructures using the high fluence material ions produced by hot, dense and extremely non-equilibrium plasma generated in a modified DPF device. In addition, we present the recent results on the fabrication of porous nano-gallium arsenide (GaAs). The details of morphological, structural and optical properties of the fabricated nano-GaAs are provided. The effect of rapid thermal annealing on the above properties of porous nano-GaAs is studied. The study reveals that it is possible to tailor the size of pores with annealing temperature. The optical properties of these porous nano-GaAs also confirm the possibility to tailor the pore sizes upon annealing. Possible applications of the fabricated and subsequently annealed porous nano-GaAs in transmission-type photo-cathodes and visible optoelectronic devices are discussed. These results suggest that the modified DPF is an effective tool for nanofabrication of continuous and porous III-V semiconductor nanomaterials. Further opportunities for using the modified DPF device for the fabrication of novel nanostructures are discussed as well.

Binding of ferric ions is essential for the biological activity of glycine-extended gastrin

International Nuclear Information System (INIS)

Baldwin, G.S.; Pannequin, J.; Hollande, F.; Shulkes, A.

2002-01-01

Full text: Non-amidated gastrins, such as glycine-extended gastrin17 (Ggly), are now known to be biologically active. Ggly stimulates cell proliferation and migration, and was recently shown to bind two ferric ions with high affinity. The objective of the present work was to define the structure of Ggly for the first time, and to investigate the role of ferric ions in biological activity. Methods: The structure of Ggly, and the identity of the ammo acids that act as ferric ion ligands, were determined by NMR and fluorescence spectroscopy. The effect on the gastric epithelial cell line IMGE-5 of Ggly fragments, and of Ggy mutants with some or all of the five consecutive glutamate residues replaced by alanine, was measured in terms of cell proliferation, cell migration and phosphorylation of focal adhesion kinase. Results: Ggly adopts a well-defined loop stabilised by hydrophobic interactions between Leu5, Tyrl2, Trp 14 and Phe17. Studies with Ggly fragments indicated that ferric ions bind via the pentaglutamate sequence, which is necessary but not sufficient for full activity Selective replacement of some or all of the glutamates results in a reduction in ferric ion binding, and complete loss of biological activity. Conclusion: Our results are consistent with the hypothesis that ferric ion binding is necessary for biological activity

The Porphyromonas gingivalis ferric uptake regulator orthologue does not regulate iron homeostasis

Directory of Open Access Journals (Sweden)

Catherine Butler

2015-09-01

Full Text Available Porphyromonas gingivalis is a Gram-negative anaerobic bacterium that has an absolute requirement for iron which it transports from the host as heme and/or Fe2+. Iron transport must be regulated to prevent toxic effects from excess metal in the cell. P. gingivalis has one ferric uptake regulator (Fur orthologue encoded in its genome called Har, which would be expected to regulate the transport and usage of iron within this bacterium. As a gene regulator, inactivation of Har should result in changes in gene expression of several genes compared to the wild-type. This dataset (GEO accession number GSE37099 provides information on expression levels of genes in P. gingivalis in the absence of Har. Surprisingly, these genes do not relate to iron homeostasis.

Absorption mechanisms for cationic and anionic mineral species on ferric iron polymer hydroxides and oxidation products of ferrous iron in aqueous media

International Nuclear Information System (INIS)

Gandon, Remi

1982-01-01

Adsorbents obtained by hydrolysing the Fe 3+ , 6H 2 O ion are made of polymers with aquo (H 2 O), hydroxo (-OH...) and oxo (...O...) ligands. Radioactive tracers reveal the importance of chemical mechanisms in adsorption phenomena on ferric oxide in aqueous media. Zn 2+ , Co 2+ and Mn 2+ cations are exchanged with hydrogen from hydroxo groups. CrO 4 2- , SeO 3 2- and Sb(OH) 6 - anions form covalent associations in place of iron ligands. The adsorption of hydrolyzed ions results in strong oxygen bridge bonds. In fresh water, Co and Mn participate alone in physical electrostatic adsorption. Iron II oxidation products generate chemical adsorptions. Zn 2+ and Sb(OH) 6 - associate with ferric hydroxides from oxidized Fe 2+ . 60 Co, 54 Mn and 51 Cr form covalent associations between unpaired 3d iron electrons and the adsorbed element. This process is not predominant with selenium IV or VI reduced to the metallic state or fixed on ferric hydroxide in the selenite form. These conclusions can be applied to pollutant analysis and to water purification and contribute to our understanding of the role of iron in the distribution of oligo-elements in aqueous media. (author) [fr

Moessbauer and infrared spectroscopy as a diagnostic tool for the characterization of ferric tannates

Energy Technology Data Exchange (ETDEWEB)

Jaen, Juan A., E-mail: jjaen@ancon.up.ac.p [Universidad de Panama, Depto. de Quimica Fisica, CITEN, Lab. No. 105, Edificio de Laboratorios Cientificos-VIP (Panama); Navarro, Cesar [Universidad de Panama, Escuela de Quimica, Facultad de Ciencias Naturales, Exactas y Tecnologia (Panama)

2009-07-15

Fourier transform infrared spectroscopy and Moessbauer spectroscopy are use for the characterization and qualitative analysis of hydrolysable and condensed tannates. The two classes of tannates may be differentiated from the characteristic IR pattern. Moessbauer proof that a mixture of mono- and bis-type ferric tannate complexes, and an iron(II)-tannin complex are obtained from the interaction of hydrolysable tannins (tannic acid and chestnut tannin) and condensed tannins (mimosa and quebracho) with a ferric nitrate solution. At pH 7, a partially hydrolyzed ferric tannate complex was also obtained.

Moessbauer and infrared spectroscopy as a diagnostic tool for the characterization of ferric tannates

International Nuclear Information System (INIS)

Jaen, Juan A.; Navarro, Cesar

2009-01-01

Fourier transform infrared spectroscopy and Moessbauer spectroscopy are use for the characterization and qualitative analysis of hydrolysable and condensed tannates. The two classes of tannates may be differentiated from the characteristic IR pattern. Moessbauer proof that a mixture of mono- and bis-type ferric tannate complexes, and an iron(II)-tannin complex are obtained from the interaction of hydrolysable tannins (tannic acid and chestnut tannin) and condensed tannins (mimosa and quebracho) with a ferric nitrate solution. At pH 7, a partially hydrolyzed ferric tannate complex was also obtained.

Binding of heavy metal ions in aggregates of microbial cells, EPS and biogenic iron minerals measured in-situ using metal- and glycoconjugates-specific fluorophores

Science.gov (United States)

Hao, Likai; Guo, Yuan; Byrne, James M.; Zeitvogel, Fabian; Schmid, Gregor; Ingino, Pablo; Li, Jianli; Neu, Thomas R.; Swanner, Elizabeth D.; Kappler, Andreas; Obst, Martin

2016-05-01

Aggregates consisting of bacterial cells, extracellular polymeric substances (EPS) and Fe(III) minerals formed by Fe(II)-oxidizing bacteria are common at bulk or microscale chemical interfaces where Fe cycling occurs. The high sorption capacity and binding capacity of cells, EPS, and minerals controls the mobility and fate of heavy metals. However, it remains unclear to which of these component(s) the metals will bind in complex aggregates. To clarify this question, the present study focuses on 3D mapping of heavy metals sorbed to cells, glycoconjugates that comprise the majority of EPS constituents, and Fe(III) mineral aggregates formed by the phototrophic Fe(II)-oxidizing bacteria Rhodobacter ferrooxidans SW2 using confocal laser scanning microscopy (CLSM) in combination with metal- and glycoconjugates-specific fluorophores. The present study evaluated the influence of glycoconjugates, microbial cell surfaces, and (biogenic) Fe(III) minerals, and the availability of ferrous and ferric iron on heavy metal sorption. Analyses in this study provide detailed knowledge on the spatial distribution of metal ions in the aggregates at the sub-μm scale, which is essential to understand the underlying mechanisms of microbe-mineral-metal interactions. The heavy metals (Au3+, Cd2+, Cr3+, CrO42-, Cu2+, Hg2+, Ni2+, Pd2+, tributyltin (TBT) and Zn2+) were found mainly sorbed to cell surfaces, present within the glycoconjugates matrix, and bound to the mineral surfaces, but not incorporated into the biogenic Fe(III) minerals. Statistical analysis revealed that all ten heavy metals tested showed relatively similar sorption behavior that was affected by the presence of sorbed ferrous and ferric iron. Results in this study showed that in addition to the mineral surfaces, both bacterial cell surfaces and the glycoconjugates provided most of sorption sites for heavy metals. Simultaneously, ferrous and ferric iron ions competed with the heavy metals for sorption sites on the organic

Evaluation of Ferric and Ferrous Iron Therapies in Women with Iron Deficiency Anaemia

Science.gov (United States)

Berber, Ilhami; Erkurt, Mehmet Ali; Aydogdu, Ismet; Kuku, Irfan

2014-01-01

Introduction. Different ferric and ferrous iron preparations can be used as oral iron supplements. Our aim was to compare the effects of oral ferric and ferrous iron therapies in women with iron deficiency anaemia. Methods. The present study included 104 women diagnosed with iron deficiency anaemia after evaluation. In the evaluations performed to detect the aetiology underlying the iron deficiency anaemia, it was found and treated. After the detection of the iron deficiency anaemia aetiology and treatment of the underlying aetiology, the ferric group consisted of 30 patients treated with oral ferric protein succinylate tablets (2 × 40 mg elemental iron/day), and the second group consisted of 34 patients treated with oral ferrous glycine sulphate tablets (2 × 40 mg elemental iron/day) for three months. In all patients, the following laboratory evaluations were performed before beginning treatment and after treatment. Results. The mean haemoglobin and haematocrit increases were 0.95 g/dL and 2.62% in the ferric group, while they were 2.25 g/dL and 5.91% in the ferrous group, respectively. A significant difference was found between the groups regarding the increase in haemoglobin and haematocrit values (P < 0.05). Conclusion. Data are submitted on the good tolerability, higher efficacy, and lower cost of the ferrous preparation used in our study. PMID:25006339

Comparison of two modified coal ash ferric-carbon micro-electrolysis ceramic media for pretreatment of tetracycline wastewater.

Science.gov (United States)

Yang, Kunlun; Jin, Yang; Yue, Qinyan; Zhao, Pin; Gao, Yuan; Wu, Suqing; Gao, Baoyu

2017-05-01

Application of modified sintering ferric-carbon ceramics (SFC) and sintering-free ferric-carbon ceramics (SFFC) based on coal ash and scrap iron for pretreatment of tetracycline (TET) wastewater was investigated in this article. Physical property, morphological character, toxic metal leaching content, and crystal component were studied to explore the application possibility of novel ceramics in micro-electrolysis reactors. The influences of operating conditions including influent pH, hydraulic retention time (HRT), and air-water ratio (A/W) on the removal of tetracycline were studied. The results showed that SFC and SFFC were suitable for application in micro-electrolysis reactors. The optimum conditions of SFC reactor were pH of 3, HRT of 7 h, and A/W of 10. For SFFC reactor, the optimum conditions were pH of 2, HRT of 7 h, and A/W of 15. In general, the TET removal efficiency of SFC reactor was better than that of SFFC reactor. However, the harden resistance of SFFC was better than that of SFC. Furthermore, the biodegradability of TET wastewater was improved greatly after micro-electrolysis pretreatment for both SFC and SFFC reactors.

Restraining Sodium Volatilization in the Ferric Bauxite Direct Reduction System

Directory of Open Access Journals (Sweden)

Wentao Hu

2016-03-01

Full Text Available Direct reduction is an emerging utilization technology of ferric bauxite. However, it requires much more sodium carbonate than ordinary bauxite does. The volatilization is one of the most significant parts of sodium carbonate consumption, as reported in previous studies. Based on the new direct reduction method for utilization of ferric bauxite, this paper has systematically investigated factors including heating temperature, heating time, and sodium carbonate dosage influencing sodium volatilization. For the purpose of reducing sodium volatilization, the Box–Benhken design was employed, and the possibility of separating iron and sodium after direct reduction was also investigated.

Removing ferric ions from concentrated acid leaching solution of an uranium ore by jarosite

International Nuclear Information System (INIS)

Song Huanbi; Hu Yezang

1997-01-01

The author expounds the fundamental rules of removing ferric ions by jarosite and presents results of removing ferric ions from concentrated acid curing-trickle leaching solution of an uranium ore. It turns out that the method can be applied to uranium hydrometallurgical process effectively

Role of Intravenous Ferric Carboxy-maltose in Pregnant Women with Iron Deficiency Anaemia.

Science.gov (United States)

Mishra, Vineet; Gandhi, Khusaili; Roy, Priyankur; Hokabaj, Shaheen; Shah, Kunur N

2017-09-08

Iron deficiency is a common nutritional deficiency amongst women of childbearing age. Peri-partum iron deficiency anaemia is associated with significant maternal, foetal and infant morbidity. Current options for treatment include oral iron, which can be ineffective and poorly tolerated, and red blood cell transfusions, which carry an inherent risk and should be avoided. Ferric carboxymaltose is a modern treatment option. The study was designed to assess the safety and efficacy of intravenous ferric carboxymaltose for correction of iron deficiency anaemia in pregnant women. A prospective study was conducted at Institute of Kidney Disease and Research Centre, Ahmedabad from January 2014 to December 2016. Antenatal women (108) with iron deficiency anaemia were the study subjects. Socio-demographic profile was recorded and anaemia was assessed based on recent haemoglobin reports. Iron deficiency was diagnosed on basis of serum ferritin value. Intravenous ferric carboxymaltose as per total correction dose (maximum 1500mg) was administered to all women; the improvement in haemoglobin levels were assessed after 3 weeks of total dose infusion. Most of the women(n= 45, 41.7%), were in the age group of 27-30 years. Most of the women (n = 64, 59.3%) had moderate anaemia as per WHO guidelines. Mean haemoglobin levels significantly increased over a period of 3 weeks after Ferric carboxymaltose administrationand no serious life threatening adverse events were observed. Intravenous ferric carboxymaltose was safe and effective in pregnent women with iron deficiency anaemia.

Safety and Efficacy of Intravenous Ferric Carboxy Maltose in Iron Deficiency Anaemia During Post-partum Period.

Science.gov (United States)

Mishra, Vineet; Roy, Priyankar; Gandhi, Khushali; Choudhary, Sumesh; Aggarwal, Rohina; Sokabaj, Shaheen

2018-01-01

Iron deficiency is the commonest treatable cause of postpartum anaemia. Parenteral iron therapy results in faster and higher replenishment of iron stores and correction of haemoglobin levels with better compliance. Ferric Carboxy Maltose is an effective and a safe option which can be administered intravenously in single total correction dose without any serious adverse effects.The study was done to evaluate the efficacy and safety of Ferric Carboxy Maltose in the treatment of iron deficiency anaemia in post-natal patients. It was an open, single arm study including 615 women with diagnosis of Iron deficiency anaemia and haemoglobin (Hb) levels between 4gm% and 11gm% from January 2013 to December 2016. Intravenous Ferric Carboxy Maltose(500-1500mg) was administered and the improvement in haemoglobin levels and iron stores were assessed after three weeks of total dose infusion. Out of the 615 women, 595 women were included in the analysis. Most of the women were in the age group of 27-30 years. Most of the women had mild anaemia as per World Health Organisation guidelines. Mean hemoglobin levels significantly increased over a period of three weeks after Ferric Carboxy Maltose administration. Other parameters like total iron binding capacity, Ferritin and Iron also had a significant improvement after Ferric Carboxy Maltose administration. No serious adverse events were observed after Ferric Carboxy Maltose. Intravenous Ferric Carboxy Maltose was an effective and a safe treatment option for iron deficiency anaemia and has an advantage of single administration of high doses without serious adverse effects.

Mössbauer and infrared spectroscopy as a diagnostic tool for the characterization of ferric tannates

Science.gov (United States)

Jaén, Juan A.; Navarro, César

2009-07-01

Fourier transform infrared spectroscopy and Mössbauer spectroscopy are use for the characterization and qualitative analysis of hydrolysable and condensed tannates. The two classes of tannates may be differentiated from the characteristic IR pattern. Mössbauer proof that a mixture of mono- and bis-type ferric tannate complexes, and an iron(II)-tannin complex are obtained from the interaction of hydrolysable tannins (tannic acid and chestnut tannin) and condensed tannins (mimosa and quebracho) with a ferric nitrate solution. At pH 7, a partially hydrolyzed ferric tannate complex was also obtained.

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

Directory of Open Access Journals (Sweden)

Golmohammadi Hassan

2013-01-01

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

CU(II): catalyzed hydrazine reduction of ferric nitrate

International Nuclear Information System (INIS)

Karraker, D.G.

1981-11-01

A method is described for producing ferrous nitrate solutions by the cupric ion-catalyzed reduction of ferric nitrate with hydrazine. The reaction is complete in about 1.5 hours at 40 0 C. Hydrazoic acid is also produced in substantial quantities as a reaction byproduct

Experimental determination of the phase boundary between kornelite and pentahydrated ferric sulfate at 0.1MPa

Science.gov (United States)

Kong, W.G.; Wang, A.; Chou, I.-Ming

2011-01-01

Recent findings of various ferric sulfates on Mars emphasize the importance of understanding the fundamental properties of ferric sulfates at temperatures relevant to that of Martian surface. In this study, the phase boundary between kornelite (Fe2(SO4)3.7H2O) and pentahydrated ferric sulfate (Fe2(SO4)3.5H2O) was experimentally determined using the humidity-buffer technique together with gravimetric measurements and Raman spectroscopy at 0.1MPa in the 36-56??C temperature range. Through the thermodynamic analysis of our experimental data, the enthalpy change (-290.8??0.3kJ/mol) and the Gibbs free energy change (-238.82??0.02kJ/mol) for each water molecule of crystallization in the rehydration of pentahydrated ferric sulfate to kornelite were obtained. ?? 2011 Elsevier B.V.

Ferric hydroxide supported gold subnano clusters or quantum dots: enhanced catalytic performance in chemoselective hydrogenation.

Science.gov (United States)

Liu, Lequan; Qiao, Botao; Ma, Yubo; Zhang, Juan; Deng, Youquan

2008-05-21

An attempt to prepare ferric hydroxide supported Au subnano clusters via modified co-precipitation without any calcination was made. High resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) have been employed to study the structure and chemical states of these catalysts. No Au species could be observed in the HRTEM image nor from the XRD pattern, suggesting that the sizes of the Au species in and on the ferric hydroxide support were less than or around 1 nm. Chemoselective hydrogenation of aromatic nitro compounds and alpha,beta-unsaturated aldehydes was selected as a probe reaction to examine the catalytic properties of this catalyst. Under the same reaction conditions, such as 100 degrees C and 1 MPa H2 in the hydrogenation of aromatic nitro compounds, a 96-99% conversion (except for 4-nitrobenzonitrile) with 99% selectivity was obtained over the ferric hydroxide supported Au catalyst, and the TOF values were 2-6 times higher than that of the corresponding ferric oxide supported catalyst with 3-5 nm size Au particles. For further evaluation of this Au catalyst in the hydrogenation of citral and cinnamaldehyde, selectivity towards unsaturated alcohols was 2-20 times higher than that of the corresponding ferric oxide Au catalyst.

Thermally assisted nanosecond laser generation of ferric nanoparticles

Science.gov (United States)

Kurselis, K.; Kozheshkurt, V.; Kiyan, R.; Chichkov, B.; Sajti, L.

2018-03-01

A technique to increase nanosecond laser based production of ferric nanoparticles by elevating temperature of the iron target and controlling its surface exposure to oxygen is reported. High power near-infrared laser ablation of the iron target heated up to 600 °C enhances the particle generation efficiency by more than tenfold exceeding 6 μg/J. Temporal and thermal dependencies of the particle generation process indicate correlation of this enhancement with the oxidative processes that take place on the iron surface during the per spot interpulse delay. Nanoparticles, produced using the heat-assisted ablation technique, are examined using scanning electron and transmission electron microscopy confirming the presence of 1-100 nm nanoparticles with an exponential size distribution that contain multiple randomly oriented magnetite nanocrystallites. The described process enables the application of high power lasers and facilitates precise, uniform, and controllable direct deposition of ferric nanoparticle coatings at the industry-relevant rates.

Modeling of sulfation of potassium chloride by ferric sulfate addition during grate-firing of biomass

DEFF Research Database (Denmark)

Wu, Hao; Jespersen, Jacob Boll; Aho, Martti

2013-01-01

Potassium chloride, KCl, formed from critical ash-forming elements released during combustion may lead to severe ash deposition and corrosion problems in biomass-fired boilers. Ferric sulfate, Fe2(SO4)3 is an effective additive, which produces sulfur oxides (SO2 and SO3) to convert KCl to the less...... harmful K2SO4. In the present study the decomposition of ferric sulfate is studied in a fast-heating rate thermogravimetric analyzer (TGA), and a kinetic model is proposed to describe the decomposition process. The yields of SO2 and SO3 from ferric sulfate decomposition are investigated in a laboratory......-scale tube reactor. It is revealed that approximately 40% of the sulfur is released as SO3, the remaining fraction being released as SO2. The proposed decomposition model of ferric sulfate is combined with a detailed gas phase kinetic model of KCl sulfation, and a simplified model of K2SO4 condensation...

Comparison of electrocoagulation and chemical coagulation for heavy metal removal

Energy Technology Data Exchange (ETDEWEB)

Akbal, F.; Camci, S. [Ondokuz Mayis University, Engineering Faculty, Environmental Engineering Department, Kurupelit, Samsun (Turkey)

2010-10-15

Copper (Cu), chromium (Cr), and nickel (Ni) removal from metal plating wastewater by electrocoagulation and chemical coagulation was investigated. Chemical coagulation was performed using either aluminum sulfate or ferric chloride, whereas electrocoagulation was done in an electrolytic cell using aluminum or iron electrodes. By chemical coagulation, Cu-, Cr-, and Ni-removal of 99.9 % was achieved with aluminum sulfate and ferric chloride dosages of 500, 1000, and 2000 mg L{sup -1}, respectively. Removal of metals by electrocoagulation was affected by the electrode material, wastewater pH, current density, number of electrodes, and electrocoagulation time. Electrocoagulation with iron electrodes at a current density of 10 mA cm{sup -2}, electrocoagulation time of 20 min, and pH 3.0 resulted in 99.9 % Cu-, 99.9 % Cr-, and 98 % Ni-removal. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

The Nox/Ferric reductase/Ferric reductase-like families of Eumycetes.

Science.gov (United States)

Grissa, Ibtissem; Bidard, Frédérique; Grognet, Pierre; Grossetete, Sandrine; Silar, Philippe

2010-09-01

Reactive Oxygen Species (ROS) are involved in plant biomass degradation by fungi and development of fungal structures. While the ROS-generating NADPH oxidases from filamentous fungi are under strong scrutiny, much less is known about the related integral Membrane (or Ferric) Reductases (IMRs). Here, we present a survey of these enzymes in 29 fungal genomes covering the entire available range of fungal diversity. IMRs are present in all fungal genomes. They can be classified into at least 24 families, underscoring the high diversity of these enzymes. Some are differentially regulated during colony or fruiting body development, as well as by the nature of the carbon source of the growth medium. Importantly, functional characterization of IMRs has been made on proteins belonging to only two families, while nothing or very little is known about the proteins of the other 22 families. Copyright © 2010 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.

Heavy metal removal from water/wastewater by nanosized metal oxides: A review

International Nuclear Information System (INIS)

Hua, Ming; Zhang, Shujuan; Pan, Bingcai; Zhang, Weiming; Lv, Lu; Zhang, Quanxing

2012-01-01

Nanosized metal oxides (NMOs), including nanosized ferric oxides, manganese oxides, aluminum oxides, titanium oxides, magnesium oxides and cerium oxides, provide high surface area and specific affinity for heavy metal adsorption from aqueous systems. To date, it has become a hot topic to develop new technologies to synthesize NMOs, to evaluate their removal of heavy metals under varying experimental conditions, to reveal the underlying mechanism responsible for metal removal based on modern analytical techniques (XAS, ATR-FT-IR, NMR, etc.) or mathematical models, and to develop metal oxide-based materials of better applicability for practical use (such as granular oxides or composite materials). The present review mainly focuses on NMOs’ preparation, their physicochemical properties, adsorption characteristics and mechanism, as well as their application in heavy metal removal. In addition, porous host supported NMOs are particularly concerned because of their great advantages for practical application as compared to the original NMOs. Also, some magnetic NMOs were included due to their unique separation performance.

Isoelectric focusing of small non-covalent metal species from plants.

Science.gov (United States)

Köster, Jessica; Hayen, Heiko; von Wirén, Nicolaus; Weber, Günther

2011-03-01

IEF is known as a powerful electrophoretic separation technique for amphoteric molecules, in particular for proteins. The objective of the present work is to prove the suitability of IEF also for the separation of small, non-covalent metal species. Investigations are performed with copper-glutathione complexes, with the synthetic ligand ethylenediamine-N,N'-bis(o-hydroxyphenyl)acetic acid (EDDHA) and respective metal complexes (Fe, Ga, Al, Ni, Zn), and with the phytosiderophore 2'-deoxymugineic acid (DMA) and its ferric complex. It is shown that ethylenediamine-N,N'-bis(o-hydroxyphenyl)acetic acid and DMA species are stable during preparative scale IEF, whereas copper-glutathione dissociates considerably. It is also shown that preparative scale IEF can be applied successfully to isolate ferric DMA from real plant samples, and that multidimensional separations are possible by combining preparative scale IEF with subsequent HPLC-MS analysis. Focusing of free ligands and respective metal complexes with di- and trivalent metals results in different pIs, but CIEF is usually needed for a reliable estimation of pI values. Limitations of the proposed methods (preparative IEF and CIEF) and consequences of the results with respect to metal speciation in plants are discussed. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effect of Ferric Ions on Bioleaching of Pentlandite Concentrate

Science.gov (United States)

Li, Qian; Lai, Huimin; Yang, Yongbin; Xu, Bin; Jiang, Tao; Zhang, Yaping

The intensified effects of ferric phosphate and ferric sulfate as nutrient and oxidant on the bioleaching of pentlandite concentrate with Acidithiobacillus ferrooxidans and Sulfobacillus thermosulfidooxidans were studied. The results showed that the nickel leaching rate was enhanced continuously with FePO4 or Fe2(SO4)3 added in certain extent, but declined at excess. For A. ferrooxidans, the optimum additive amount of Fe2(SO4)3 was 6.63mM/L and the nickel leaching rate reached 71.76%. Compared with Fe2(SO4)3, the optimum additive amount of FePO4 was 26.52mM/L for both strains. For A. ferrooxidans and S. thermosulfidooxidans, the nickel leaching rate could increase to 98.06% and 98.11% which was 1.83 times and 1.55 times of the leachig rate of blank test, respectively.

Bioavailability and the mechanisms of intestinal absorption of iron from ferrous ascorbate and ferric polymaltose in experimental animals

International Nuclear Information System (INIS)

Johnson, G.; Jacobs, P.

1990-01-01

The comparative bioavailability from matching quantities of iron in the form of ferrous ascorbate or ferric polymaltose was defined in rats. Studies were carried out in the intact animals under basal conditions and also when requirements for this metal were either increased or decreased by manipulating stores or erythropoietic activity. No significant difference was found in the total quantity of iron absorbed from either salt or complex under any of these circumstances, suggesting that the mucosal mechanism regulating the overall process was common to both. However, the rate of transfer from the lumen into portal blood was distinctive, reaching a maximum with salt at 30 min compared to 24 h for the complex. To explore the possibility that iron from the two sources was initially handled by different subcellular pathways, the radiolabeled compounds were instilled into loops of bowel that had been isolated between ligatures in vivo. Enterocytes were harvested and fractionated, and incorporation into ferritin and transferrin was determined using RIA. From salt, iron appeared rapidly in duodenal but not ileal ferritin, whereas mucosal transferrin increased under conditions of stimulated absorption, suggesting that this protein may act as a shuttle for the metal. In contrast, iron from polymaltose showed a cumulative incorporation into duodenal ferritin over time that correlated with iron absorption, defined by the appearance of radiolabel in the serum and in the carcass; a similar pattern was demonstrable in ileal mucosal cells. Conversely, binding of iron to transferrin was minimal. No iron polymaltose was found within the mucosal cells. It is suggested that the low rate of iron transfer from this ferric complex may reflect its extracellular breakdown in the lumen of the gastrointestinal tract

Evolution of the local structure of ferric gels and polymers during the crystallisation of iron oxides. Application to uranium trapping

International Nuclear Information System (INIS)

Combes, Jean-Marie

1988-01-01

A first part of this research thesis reports the study of the structure of the main iron oxides and oxy-hydroxides, and of the protocols for the synthesis of ferric gels. The second part reports a topological approach by EXAFS (Extended X-Ray Absorption Fine Structure) of the structure of Mn and Fe oxides and oxy-hydroxides. The third part reports the study of the formation of ferric oxides from aqueous solutions by using a polyhedral approach by X-ray absorption spectroscopy in the case of hydrolysis and formation of ferric gels, and in the case of haematite formation from ferric gels. The next parts respectively report the study of the local structure of gels synthesised from iron(II), and the study of the local structure of natural ferric gels. Then, the author reports the study of sites of uranium bonding on ferric gels [fr

Extraction of metals from ores by bacterial leaching: present status and future prospects

International Nuclear Information System (INIS)

Kelly, D.P.

1977-01-01

The principal organism effecting bacterial leaching of ferrous and sulfide ores is Thiobacillus ferrooxidans, though other thiobacilli and other bacteria may be involved. The process depends on (a) direct solubilization of metal sulfides by bacterial oxidation; (b) dissolution of metal sulfides or oxides by ferric iron produced by bacterial pyrite oxidation. Mining spoil dumps and low grade ores can be leached for copper or uranium by cheap low-level technology. Dump leaching enables maximum recovery of valuable metal from any ore, but makes possible exploitation of very low grade Cu and U ores. Continuous extraction processes are possible where a continuously growing bacterial culture is fed with pyritic ores (or FeSO 4 or other sulfide) and continuous metal solubilization proceeds. Intimate contact between the bacteria and the ore to be leached (especially with uranium oxide ores) is not always necessary: leaching of UO 2 ores probably depends only on ferric iron reaction with the ore. Degradation of pyrite-containing rocks may also be developed as part of future recovery processes for petroleum from oil shales. Two-stage leaching systems present the best prospect for developing a higher-level technology for metal extraction. State 1: bacterial generation of Fe 3+ from pyrite or a Fe 2+ source; Stage 2: chemical leaching of ore by Fe 3+ in acid solution. Two-stage processes can be surface processes using crushed or milled ores or can be applied to underground solution mining, when an ore (e.g. uranium) can be leached by pumping Fe 3+ solutions through shattered underground deposits, metal recovered (e.g. solvent extraction) and Fe 3+ regenerated by bacterial oxidation at the surface. The use of controlled continuous microbial cultures to generate either bacteria or ferric iron is outlined

Metal-dielectric metamaterials for guided wave silicon photonics.

Science.gov (United States)

Lupu, A; Dubrovina, N; Ghasemi, R; Degiron, A; de Lustrac, A

2011-11-21

The aim of the present paper is to investigate the potential of metallic metamaterials for building optical functions in guided wave optics at 1.5 µm. A significant part of this work is focused on the optimization of the refractive index variation associated with localized plasmon resonances. The minimization of metal related losses is specifically addressed as well as the engineering of the resonance frequency of the localized plasmons. Our numerical modeling results show that a periodic chain of gold cut wires placed on the top of a 100 nm silicon waveguide makes it possible to achieve a significant index variation in the vicinity of the metamaterial resonance and serve as building blocks for implementing optical functions. The considered solutions are compatible with current nano-fabrication technologies. © 2011 Optical Society of America

Graphene oxide/ferric hydroxide composites for efficient arsenate removal from drinking water

International Nuclear Information System (INIS)

Zhang Kai; Dwivedi, Vineet; Chi Chunyan; Wu Jishan

2010-01-01

A series of novel composites based on graphene oxide (GO) cross-linked with ferric hydroxide was developed for effective removal of arsenate from contaminated drinking water. GO, which was used as a supporting matrix here, was firstly treated with ferrous sulfate. Then, the ferrous compound cross-linked with GO was in situ oxidized to ferric compound by hydrogen peroxide, followed by treating with ammonium hydroxide. The morphology and composition of the composites were analyzed by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The ferric hydroxide was found to be homogenously impregnated onto GO sheets in amorphous form. These composites were evaluated as absorbents for arsenate removal from contaminated drinking water. For the water with arsenate concentration at 51.14 ppm, more than 95% of arsenate was absorbed by composite GO-Fe-5 with an absorption capacity of 23.78 mg arsenate/g of composite. Effective arsenate removal occurred in a wide range of pH from 4 to 9. However, the efficiency of arsenate removal was decreased when pH was increased to higher than 8.

Thermodynamics of ion-exchange on ferric antimonate

International Nuclear Information System (INIS)

Rawat, J.P.; Muktawat, K.P.S.

1981-01-01

A simple approach to ion-exchange equilibria on ferric antimonate has been applied. The values of selectivity coefficients for Ba 2+ , Mg 2+ , Ca 2+ and Sr 2+ have been measured using equilibrium experiments at constant ionic strength and at different temperatures from 20 to 60 0 C. The thermodynamic equilibrium constant and values of ΔG 0 , ΔH 0 and ΔS 0 are reported. (author)

Production of ferric sulphate from pyrite by thiobacillus ferrooxidans. Application to uranium ore leaching

International Nuclear Information System (INIS)

Rouas, C.

1988-12-01

A process for uranium extraction by oxidizing solutions of ferric sulphate produced by T. ferrooxidans from pyrite is developed. A new counting method specific of T. ferrooxidans is designed. An uranium resistant wild strain, with oxidizing properties as high as the strain ATCC 19859, is isolated. Optimal conditions for ferric sulphate production from pyrite are defined (pH 1.8, density of the medium 1.2%, pyrite granulometry [fr

Adherence rates to ferric citrate as compared to active control in patients with end stage kidney disease on dialysis.

Science.gov (United States)

Jalal, Diana; McFadden, Molly; Dwyer, Jamie P; Umanath, Kausik; Aguilar, Erwin; Yagil, Yoram; Greco, Barbara; Sika, Mohammed; Lewis, Julia B; Greene, Tom; Goral, Simin

2017-04-01

Oral phosphate binders are the main stay of treatment of hyperphosphatemia. Adherence rates to ferric citrate, a recently approved phosphate binder, are unknown. We conducted a post-hoc analysis to evaluate whether adherence rates were different for ferric citrate vs. active control in 412 subjects with end stage kidney disease (ESKD) who were randomized to ferric citrate vs. active control (sevelamer carbonate and/or calcium acetate). Adherence was defined as percent of actual number of pills taken to total number of pills prescribed. There were no significant differences in baseline characteristics including gender, race/ethnicity, and age between the ferric citrate and active control groups. Baseline phosphorus, calcium, and parathyroid hormone levels were similar. Mean (SD) adherence was 81.4% (17.4) and 81.7% (15.9) in the ferric citrate and active control groups, respectively (P = 0.88). Adherence remained similar between both groups after adjusting for gender, race/ethnicity, age, cardiovascular disease (CVD), and diabetic nephropathy (mean [95% CI]: 81.4% [78.2, 84.6] and 81.5% [77.7, 85.2] for ferric citrate and active control, respectively). Gender, race/ethnicity, age, and diagnosis of diabetic nephropathy did not influence adherence to the prescribed phosphate binder. Subjects with CVD had lower adherence rates to phosphate binder; this was significant only in the active control group. Adherence rates to the phosphate binder, ferric citrate, were similar to adherence rates to active control. Similar adherence rates to ferric citrate are notable since tolerance to active control was an entry criteria and the study was open label. Gender, race/ethnicity, nor age influenced adherence. © 2016 International Society for Hemodialysis.

Evaluation of oral abdominal contrast agent containing ferric ammonium citrate

International Nuclear Information System (INIS)

Shiga, Toshiko; Kawamura, Yasutaka; Iwasaki, Toshiko

1991-01-01

We evaluated the effectiveness of oral MRI contrast agent containing ferric ammonium citrate. Twenty patients were arbitrarily divided into 2 groups according to the given dose of 100 and 200 mg Fe of oral MRI contrast agent. MRI was performed before and immediately after ingesting 300 ml solution of oral MRI contrast agent using a 1.5 T superconducting system (GE: Signa). Each dose of 100 and 200 mg Fe of oral MRI contrast agent produced sufficient enhancement of gastrointestinal tract, enough to make clear the pancreatic contour and porta hepatis. There was no significant change in blood and urine analysis observed after taking oral MRI contrast agent. The use of ferric ammonium citrate as an oral MRI contrast agent seems to add valuable information in performing upper abdominal MRI imaging. (author)

Influence of different concentration of heavy metals on the seed ...

African Journals Online (AJOL)

use

0.001, 0.01, 0.1 and 1%) of lead acetate, cupric carbonate and ferric chloride were ... nutrients and seem to be more or less toxic to plants and ... Some heavy metals at low doses are essential ..... The toxic action and interactions of copper.

A New Direction for Biomining: Extraction of Metals by Reductive Dissolution of Oxidized Ores

Directory of Open Access Journals (Sweden)

Kevin B. Hallberg

2013-01-01

Full Text Available Biomining, the biotechnology that uses microorganisms to extract metals from ores and concentrates, is currently used exclusively for processing reduced ores and mine wastes. Metals of economic value also occur extensively in oxidized ores, such as nickel laterites. While these are not amenable to oxidative dissolution, the ferric iron minerals they contain can, in theory, be disrupted by iron reduction, causing associated metals to be released. We have harnessed the ability of the facultatively anaerobic, acidophilic bacterium Acidithiobacillus ferroooxidans to couple the oxidation of elemental sulphur to the reduction of ferric iron in the goethite fraction of a limonitic nickel ore at 30 °C. Nickel and other metals (Co, Cr and Mn were effectively solubilised and maintained in solution due to the low pH (1.8 of the leach liquor. The results highlight the potential for the bioprocessing of oxidized, iron-rich ores using an approach that is energy-saving and environmentally-benign compared with metallurgical processes currently applied to the extraction of Ni from lateritic ores.

A Cost-effectiveness Analysis of Ferric Carboxymaltose in Patients With Iron Deficiency and Chronic Heart Failure in Spain.

Science.gov (United States)

Comín-Colet, Josep; Rubio-Rodríguez, Darío; Rubio-Terrés, Carlos; Enjuanes-Grau, Cristina; Gutzwiller, Florian S; Anker, Stefan D; Ponikowski, Piotr

2015-10-01

Treatment with ferric carboxymaltose improves symptoms, functional capacity, and quality of life in patients with chronic heart failure and iron deficiency. The aim of this study was to assess the cost-effectiveness of ferric carboxymaltose treatment vs no treatment in these patients. We used an economic model based on the Spanish National Health System, with a time horizon of 24 weeks. Patient characteristics and ferric carboxymaltose effectiveness (quality-adjusted life years) were taken from the Ferinject® Assessment in patients with IRon deficiency and chronic Heart Failure trial. Health care resource use and unit costs were taken either from Spanish sources, or from the above mentioned trial. In the base case analysis, patients treated with and without ferric carboxymaltose treatment acquired 0.335 and 0.298 quality-adjusted life years, respectively, representing a gain of 0.037 quality-adjusted life years for each treated patient. The cost per patient was €824.17 and €597.59, respectively, resulting in an additional cost of €226.58 for each treated patient. The cost of gaining 1 quality adjusted life year with ferric carboxymaltose was €6123.78. Sensitivity analyses confirmed the robustness of the model. The probability of ferric carboxymaltose being cost-effective (< €30 000 per quality-adjusted life year) and dominant (more effective and lower cost than no treatment) was 93.0% and 6.6%, respectively. Treatment with ferric carboxymaltose in patients with chronic heart failure and iron deficiency, with or without anemia, is cost-effective in Spain. Copyright © 2014 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

Gravity settling of precipitated magnetite and ferric floc

International Nuclear Information System (INIS)

Holt, N.S.; Loft, P.R.

1983-06-01

A comparison is presented of the gravity settling performance of ferric floc and magnetite, both in batch settling tests, and on a continuous gravity settler. The precipitation of magnetite from solution on a continuous basis was also demonstrated, and the process was shown not to be significantly affected by the presence of a wide range of chemical species. (U.K.)

Oxidation of Alcohols by Ferric Nitrate in the Presence of Barium ...

African Journals Online (AJOL)

NJD

Oxidation, ferric nitrate, barium chloride, silica sulphuric acid, heterogeneous or solvent-free conditions. 1. Introduction ... economic advantage and environment protection. ... by TLC. After completion, structure of the product was charac-.

Assembling phosphorene flexagons for 2D electron-density-guided nanopatterning and nanofabrication.

Science.gov (United States)

Kang, Kisung; Jang, Woosun; Soon, Aloysius

2017-07-27

To build upon the rich structural diversity in the ever-increasing polymorphic phases of two-dimensional phosphorene, we propose different assembly methods (namely, the "bottom-up" and "top-down" approaches) that involve four commonly reported parent phases (i.e. the α-, β-, γ-, and δ-phosphorene) in combination with the lately reported remarkably low-energy one-dimensional defects in α-phosphorene. In doing so, we generate various periodically repeated phosphorene patterns in these so-called phosphorene flexagons and present their local electron density (via simulated scanning tunneling microscopy (STM) images). These interesting electron density patterns seen in the flexagons (mimicking symmetry patterns that one may typically see in a kaleidoscope) may assist as potential 2D templates where electron-density-guided nanopatterning and nanofabrication in complex organized nanoarchitectures are important.

Bio-inspired silicon nanospikes fabricated by metal-assisted chemical etching for antibacterial surfaces

Science.gov (United States)

Hu, Huan; Siu, Vince S.; Gifford, Stacey M.; Kim, Sungcheol; Lu, Minhua; Meyer, Pablo; Stolovitzky, Gustavo A.

2017-12-01

The recently discovered bactericidal properties of nanostructures on wings of insects such as cicadas and dragonflies have inspired the development of similar nanostructured surfaces for antibacterial applications. Since most antibacterial applications require nanostructures covering a considerable amount of area, a practical fabrication method needs to be cost-effective and scalable. However, most reported nanofabrication methods require either expensive equipment or a high temperature process, limiting cost efficiency and scalability. Here, we report a simple, fast, low-cost, and scalable antibacterial surface nanofabrication methodology. Our method is based on metal-assisted chemical etching that only requires etching a single crystal silicon substrate in a mixture of silver nitrate and hydrofluoric acid for several minutes. We experimentally studied the effects of etching time on the morphology of the silicon nanospikes and the bactericidal properties of the resulting surface. We discovered that 6 minutes of etching results in a surface containing silicon nanospikes with optimal geometry. The bactericidal properties of the silicon nanospikes were supported by bacterial plating results, fluorescence images, and scanning electron microscopy images.

Hemispherical Shell Nanostructures from Metal-Stripped Embossed Alumina on Aluminum Templates

DEFF Research Database (Denmark)

Nielsen, Peter; Albrektsen, Ole; Simonsen, Adam Cohen

2011-01-01

aluminum/ alumina (Al/Al2O3) templates as a novel and versatile nanofabrication procedure, and we demonstrate explicitly how to exploit the technique for developing large-area hexagonally close-packed hemispherical shell nanostructures by stripping noble metal layers from embossed templates fabricated from...... anodized Al. Utilizing for this process the linear relationship between anodization voltage and the resulting interpore distance in the formed oxide, it is possible to tune the radius of curvature of the resulting hemispherical shells continuously, which in turn results in tunable optical properties...

Part 5: Experimental periods using a ferrous-ferric chloride blend

African Journals Online (AJOL)

drinie

A blend of ferrous chloride and ferric chloride (FeCl2-FeCl3) was simultaneously dosed into an activated sludge system at .... theoretical oxygen demand for this reaction is small, namely 0.15 ...... The role of bacterial extracellular polymers.

A case of osteomalacia due to deranged mineral balance caused by saccharated ferric oxide and short-bowel syndrome

Science.gov (United States)

Nomoto, Hiroshi; Miyoshi, Hideaki; Nakamura, Akinobu; Nagai, So; Kitao, Naoyuki; Shimizu, Chikara; Atsumi, Tatsuya

2017-01-01

Abstract Rationale: Saccharated ferric oxide has been shown to lead to elevation of fibroblast growth factor 23, hypophosphatemia, and, consequently, osteomalacia. Moreover, mineral imbalance is often observed in patients with short-bowel syndrome to some degree. Patient concerns: A 62-year-old woman with short-bowel syndrome related with multiple resections of small intestines due to Crohn disease received regular intravenous administration of saccharated ferric oxide. Over the course of treatment, she was diagnosed with tetany, which was attributed to hypocalcemia. Additional assessments of the patient revealed not only hypocalcemia, but also hypophosphatemia, hypomagnesemia, osteomalacia, and a high concentration of fibroblast growth factor 23 (314 pg/mL). Diagnoses: We diagnosed her with mineral imbalance-induced osteomalacia due to saccharated ferric oxide and short-bowel syndrome. Interventions: Magnesium replacement therapy and discontinuation of saccharated ferric oxide alone. Outcomes: These treatments were able to normalize her serum mineral levels and increase her bone mineral density. Lessons: This case suggests that adequate evaluation of serum minerals, including phosphate and magnesium, during saccharated ferric oxide administration may be necessary, especially in patients with short-bowel syndrome. PMID:28953654

Assembly of metallic nanoparticle arrays on glass via nanoimprinting and thin-film dewetting

Directory of Open Access Journals (Sweden)

Sun-Kyu Lee

2017-05-01

Full Text Available We propose a nanofabrication process to generate large-area arrays of noble metal nanoparticles on glass substrates via nanoimprinting and dewetting of metallic thin films. Glass templates were made via pattern transfer from a topographic Si mold to an inorganically cross-linked sol–gel (IGSG resist on glass using a two-layer polydimethylsiloxane (PDMS stamp followed by annealing, which turned the imprinted resist into pure silica. The transparent, topographic glass successfully templated the assembly of Au and Ag nanoparticle arrays via thin-film deposition and dewetting at elevated temperatures. The microstructural and mechanical characteristics that developed during the processes were discussed. The results are promising for low-cost mass fabrication of devices for several photonic applications.

Assembly of metallic nanoparticle arrays on glass via nanoimprinting and thin-film dewetting.

Science.gov (United States)

Lee, Sun-Kyu; Hwang, Sori; Kim, Yoon-Kee; Oh, Yong-Jun

2017-01-01

We propose a nanofabrication process to generate large-area arrays of noble metal nanoparticles on glass substrates via nanoimprinting and dewetting of metallic thin films. Glass templates were made via pattern transfer from a topographic Si mold to an inorganically cross-linked sol-gel (IGSG) resist on glass using a two-layer polydimethylsiloxane (PDMS) stamp followed by annealing, which turned the imprinted resist into pure silica. The transparent, topographic glass successfully templated the assembly of Au and Ag nanoparticle arrays via thin-film deposition and dewetting at elevated temperatures. The microstructural and mechanical characteristics that developed during the processes were discussed. The results are promising for low-cost mass fabrication of devices for several photonic applications.

Reaction of ferric leghemoglobin with H2O2

DEFF Research Database (Denmark)

Moreau, S; Davies, M J; Puppo, A

1995-01-01

Ferric leghemoglobin in the presence of H2O2 is known to give rise to protein radicals, at least one of which is centred on a tyrosine residue. These radicals are quenched by at least two processes. The first one involves an intramolecular heme-protein cross-link probably involving the tyrosine r...

Influence of Carbon Sources and Electron Shuttles on Ferric Iron Reduction by Cellulomonas sp. Strain ES6

Energy Technology Data Exchange (ETDEWEB)

Dr Robin Gerlach; Erin K. Field; Sridhar Viamajala; Brent M. Peyton; William A. Apel; Al B. Cunningham

2011-09-01

Microbially reduced iron minerals can reductively transform a variety of contaminants including heavy metals, radionuclides, chlorinated aliphatics, and nitroaromatics. A number of Cellulomonas spp. strains, including strain ES6, isolated from aquifer samples obtained at the U.S. Department of Energy's Hanford site in Washington, have been shown to be capable of reducing Cr(VI), TNT, natural organic matter, and soluble ferric iron [Fe(III)]. This research investigated the ability of Cellulomonas sp. strain ES6 to reduce solid phase and dissolved Fe(III) utilizing different carbon sources and various electron shuttling compounds. Results suggest that Fe(III) reduction by and growth of strain ES6 was dependent upon the type of electron donor, the form of iron present, and the presence of synthetic or natural organic matter, such as anthraquinone-2,6-disulfonate (AQDS) or humic substances. This research suggests that Cellulomonas sp. strain ES6 could play a significant role in metal reduction in the Hanford subsurface and that the choice of carbon source and organic matter addition can allow for independent control of growth and iron reduction activity.

Treatment of Highly Turbid Water by Polyaluminum Ferric Chloride (PAFCL

Directory of Open Access Journals (Sweden)

Fazel Fazel Mohammadi-Moghaddam

2015-10-01

Full Text Available Background & Aims of the Study: In some situation like rainfall seasons raw water become very turbid so it affected the water treatment plant processes and quality of produced water. Treatment of very high turbid water has some concerns like precursors for disinfection by-products and very loading rate of particle on filter's media and consequently increases in water consumption for filter backwash. This paper investigates the performance of a composite inorganic polymer of aluminium and ferric salt, Polyaluminium ferric chloride (PAFCl, for the removal of turbidity, color and natural organic matter (NOM from high turbid water. Materials and Methods: Experiments were carried out by Jar test experiment by synthetic water samples with 250 and 500 NTU turbidity that prepared in laboratory. Results: The results of conventional jar test showed that the optimum pH for coagulation of water sample was 7.5 to 8 and optimum dosage of the coagulant was 10 mg/L. Removal efficiency of turbidity, color and UV adsorbent at 254 nm at optimum dose and pH without filtration was 99.92%, 100% and 80.6% respectively for first sample (250 NTU and 99.95%, 99.49% and 84.77 for second sample (500 NTU respectively. Conclusion: It concluded that polyaluminium ferric chloride has a very good efficiency for the removal of turbidity, color and organic matter in high turbid water. Also it can be select as a coagulant for high turbid water and some waste water from water treatment plant like filter backwash water.

Equilibrium Studies of Fluoride Adsorption onto a Ferric Poly ...

African Journals Online (AJOL)

African countries along the Great Rift Valley are among areas of the world where excess fluoride in water sources is a major public health problem. In this work, the removal of fluoride (F) from water solutions using a ferric poly-mineral (FPM) from Kenya was therefore studied using batch adsorption experiments. The effect of ...

Beta transmutations in apatites with ferric iron as an electron acceptor - implication for nuclear waste form development.

Science.gov (United States)

Yao, Ge; Zhang, Zelong; Wang, Jianwei

2017-09-27

Apatite-structured materials have been considered for the immobilization of a number of fission products from reprocessing nuclear fuel because of their chemical durability as well as compositional and structural flexibility. It is hypothesized that the effect of beta decay on the stability can be mitigated by introducing an appropriate electron acceptor at the neighboring sites in the structure. The decay series 137 Cs → 137 Ba and 90 Sr → 90 Y → 90 Zr were investigated using a spin-polarized DFT approach to test the hypothesis. Apatites with compositions of Ca 10 (PO 4 ) 6 F 2 and Ca 4 Y 6 (SiO 4 ) 6 F 2 were selected as model systems for the incorporation of radionuclides Cs and Sr, respectively. Ferric iron was introduced in the structure as an electron acceptor. Electron density of states, crystal and defect structures, and energies before and after beta decay were calculated. The calculated electron density of states suggests that the extra electron is localized at the ferric iron, which changes its oxidation state and becomes ferrous iron. The crystal and defect structures were analyzed based on the volume, lattice parameters, radial distribution functions, metal cation to coordinating oxygen distances, and the metaprism twist angle of the apatite crystal structure. The results show that there are minor changes in the crystal and defect structures of CsFeCa 8 (PO 4 ) 6 F 2 with Cs + and Fe 3+ substitutions undergoing the Cs → Ba transmutation, and of Ca 3 SrY 4 Fe 2 (SiO 4 ) 6 F 2 with Sr 2+ and Fe 3+ substitutions undergoing the Sr → Y → Zr transmutations. The last decay change, from Y 3+ → Zr 4+ , causes relatively larger changes in the local defect structure around Zr involving the coordination environment but the change is not significant to the crystal structure. The results on calculated cohesive energy suggest that the transmutations Cs + → Ba 2+ and Sr 2+ → Y 3+ → Zr 4+ in both apatite compositions are energetically favorable

The influence of surfactant on the synthesis of gamma ferric oxide: implications on phase composition and magnetic properties

International Nuclear Information System (INIS)

Narasimhan, B.R.V.; Prabhakar, S.; Manohar, P.; Gnanam, F.D.

2002-01-01

It has already been established that ferrous carbonate precipitated from the reaction of ferrous sulphate and sodium carbonate, on direct thermal decomposition yields gamma ferric oxide. The present work describes the effect of sodium lauryl sulphate (Sodium dodecyl sulphate) on the synthesis of gamma ferric oxide when it is introduced during the precipitation of ferrous carbonate. Since ferrous carbonate undergoes rapid oxidation on standing in air, the extent of oxidation in presence of sodium lauryl sulphate is also studied using oxidation-reduction potential measurements. The ferric oxide powders are characterized for phase analysis (XRD), magnetic properties (VSM) and particle size analysis. (author)

Scalable nanofabrication of U-shaped nanowire resonators with tunable optical magnetism.

Science.gov (United States)

Zhou, Fan; Wang, Chen; Dong, Biqin; Chen, Xiangfan; Zhang, Zhen; Sun, Cheng

2016-03-21

Split ring resonators have been studied extensively in reconstituting the diminishing magnetism at high electromagnetic frequencies in nature. However, breakdown in the linear scaling of artificial magnetism is found to occur at the near-infrared frequency mainly due to the increasing contribution of self-inductance while reducing dimensions of the resonators. Although alternative designs have enabled artificial magnetism at optical frequencies, their sophisticated configurations and fabrication procedures do not lend themselves to easy implementation. Here, we report scalable nanofabrication of U-shaped nanowire resonators (UNWRs) using the high-throughput nanotransfer printing method. By providing ample area for conducting oscillating electric current, UNWRs overcome the saturation of the geometric scaling of the artificial magnetism. We experimentally demonstrated coarse and fine tuning of LC resonances over a wide wavelength range from 748 nm to 1600 nm. The added flexibility in transferring to other substrates makes UNWR a versatile building block for creating functional metamaterials in three dimensions.

Ferric reductase activity of low molecular weight human milk fraction is associated with enhanced iron solubility and uptake in Caco-2 cells.

Science.gov (United States)

Pullakhandam, Raghu; Nair, Madhavan Krishnapillai; Kasula, Sunanda; Kilari, Sreenivasulu; Thippande, Tippeswamy Gowda

2008-09-19

It is known that the fractional absorption of extrinsic iron from human milk is higher in infants and adults. A low molecular weight milk fraction has been proposed to increase the bioavailability of iron from human milk. Nevertheless, the mechanisms remained elusive. Here in we demonstrate ferric reductase activity (Km7.73x10(-6)M) in low molecular weight human milk fraction (10kF, filtrate derived from ultra filtration of milk whey through 10kDa cutoff membrane), which increased ferric iron solubility and iron uptake in Caco-2 cells. The 10kF fraction was as effective as ascorbic acid (1:20 iron to ascorbic acid) in increasing the ferric iron solubility and uptake in Caco-2 cells. Further, gel filtration chromatography on peptide column led to co-elution of ferric reductase and iron solubilization activities at an apparent molecular mass of iron in Caco-2 cells. Thus, it is concluded that human milk possesses ferric reductase activity and is associated with ferric iron solubilization and enhanced absorption.

Preparation of ferric acetylacetonate, bonzonate and caprate labelled with Fe-55 and tests of application to liquid scintillation measurements

International Nuclear Information System (INIS)

Los Arcos, J.M.; Rodriguez Barquero, L.; Grau Malonda, A.

1990-01-01

The methods of preparation of ferric acetylacetonate, benzoate and caprate labelled with 55 Fe are described. The quenching effect, the spectral baehaviour and the count rate stability are studied by liquid scintillation measurements in toluene, INSTAGEL and HISAFE II, for two different values of the sample concentration. The ferric acetylaceton-ate is stable for all the three scintillators but shows a strong quench, while the ferric benzoate and caprate are stable only for INSTAGEL and HISAFE II showing no significant quench at the concentrat-ions of interest in habitual measurements. (Author)

Template-free electrochemical nanofabrication of polyaniline nanobrush and hybrid polyaniline with carbon nanohorns for supercapacitors

Energy Technology Data Exchange (ETDEWEB)

Wei Di; Andrew, Piers; Ryhaenen, Tapani [Nokia Research Centre Cambridge, Broers Building, 21 J J Thomson Avenue, Cambridge CB3 0FA (United Kingdom); Wang, Haolan; Hiralal, Pritesh; Amaratunga, Gehan A J [Electrical Engineering Division, Department of Engineering, University of Cambridge, 9 J J Thomson Avenue, Cambridge CB3 0FA (United Kingdom); Hayashi, Yasuhiko, E-mail: di.wei@nokia.com, E-mail: gaja1@cam.ac.uk [Department of Materials Science, Nagoya Institute of Technology, Nagoya 466-8555 (Japan)

2010-10-29

Polyaniline (PANI) nanobrushes were synthesized by template-free electrochemical galvanostatic methods. When the same method was applied to the carbon nanohorn (CNH) solution containing aniline monomers, a hybrid nanostructure containing PANI and CNHs was enabled after electropolymerization. This is the first report on the template-free method to make PANI nanobrushes and homogeneous hybrid soft matter (PANI) with carbon nanoparticles. Raman spectroscopy was used to analyze the interaction between CNH and PANI. Electrochemical nanofabrication offers simplicity and good control when used to make electronic devices. Both of these materials were applied in supercapacitors and an improvement capacitive current by using the hybrid material was observed.

Template-free electrochemical nanofabrication of polyaniline nanobrush and hybrid polyaniline with carbon nanohorns for supercapacitors

Science.gov (United States)

Wei, Di; Wang, Haolan; Hiralal, Pritesh; Andrew, Piers; Ryhänen, Tapani; Hayashi, Yasuhiko; Amaratunga, Gehan A. J.

2010-10-01

Polyaniline (PANI) nanobrushes were synthesized by template-free electrochemical galvanostatic methods. When the same method was applied to the carbon nanohorn (CNH) solution containing aniline monomers, a hybrid nanostructure containing PANI and CNHs was enabled after electropolymerization. This is the first report on the template-free method to make PANI nanobrushes and homogeneous hybrid soft matter (PANI) with carbon nanoparticles. Raman spectroscopy was used to analyze the interaction between CNH and PANI. Electrochemical nanofabrication offers simplicity and good control when used to make electronic devices. Both of these materials were applied in supercapacitors and an improvement capacitive current by using the hybrid material was observed.

Nano-fabricated plasmonic optical transformer

Science.gov (United States)

Choo, Hyuck; Cabrini, Stefano; Schuck, P. James; Liang, Xiaogan; Yablonovitch, Eli

2015-06-09

The present invention provides a plasmonic optical transformer to produce a highly focuses optical beam spot, where the transformer includes a first metal layer, a dielectric layer formed on the first metal layer, and a second metal layer formed on the dielectric layer, where the first metal layer, the dielectric layer, and the second layer are patterned to a shape including a first section having a first cross section, a second section following the first section having a cross-section tapering from the first section to a smaller cross-section, and a third section following the second section having a cross-section matching the tapered smaller cross-section of the second section.

Effect of glutaraldehyde and ferric sulfate on shear bond strength of adhesives to primary dentin

Directory of Open Access Journals (Sweden)

Prabhakar A

2008-12-01

Full Text Available Aim: The present study was undertaken to evaluate the effect of alternative pulpotomy agents such as glutaraldehyde and ferric sulfate on the shear bond strength of self-etch adhesive systems to dentin of primary teeth. Materials and Methods: Eighty human primary molar teeth were sectioned in a mesiodistal direction and divided into experimental and control groups. Lingual dentin specimens in experimental groups were treated with glutaraldehyde and ferric sulfate. Buccal surfaces soaked in water served as control group. Each group was then divided into two groups based on the adhesive system used: Clearfil SE Bond and Adper Prompt L-Pop. A teflon mold was used to build the composite (Filtek Z-250 cylinders on the dentinal surface of all the specimens. Shear bond strength was tested for all the specimens with an Instron Universal Testing Machine. The failure mode analysis was performed with a Scanning Electron Microscope (SEM. Results: The results revealed that glutaraldehyde and ferric sulfate significantly reduced the shear bond strength of the tested adhesive systems to primary dentin. Clearfil SE Bond showed much higher shear bond strength than Adper Prompt L Pop to primary dentin. SEM analysis revealed a predominant cohesive failure mode for both adhesive systems. Conclusion: This study revealed that the pulpotomy medicaments glutaraldehyde and ferric sulfate adversely affected the bonding of self-etch adhesive systems to primary dentin.

Total gastrectomy due to ferric chloride intoxication.

Science.gov (United States)

Menéndez, A Mesut; Abramson, Leonardo; Vera, Raúl A; Duza, Guillermo E; Palermo, Mariano

2015-09-01

The ferric chloride intoxication is frequently caused by accident. Its toxicity is generally underrated, which can lead to fatal evolution or irreversible consequences. In this case, the caustic condition of the substance is related to the toxic properties of iron. A 36-year-old male patient arrives by ambulance indicating sensory deterioration. He presents erosive injuries in the buccal cavity and in the oropharynx, brownish teeth and metabolic acidosis. Toxicology tests and ferritin blood dosage are requested, which show a result from 1400 mg/dl. The symptoms are interpreted as acute iron intoxication. Due to the unfavorable evolution of his condition, an abdominal and pelvic CT scan are performed, which show extensive pneumoperitoneum and free fluid in the abdominal cavity. An exploratory laparotomy, a total gastrectomy with esophagostomy and feeding jejunostomy, washing and drainage due to perforated gastric necrosis caused by caustic ingestion are performed. In our country, there is a high rate of intoxication caused by iron compounds, although it is not statistically measured. Nevertheless, the ferric chloride intoxication is extremely infrequent. The ingestion of this product leads to complications, which are associated with the iron concentration and its condition as a caustic agent. The surgical indications in the presence of intoxication caused by iron compounds are: stomach evacuation of iron, gastric necrosis, perforation or peritonitis and stenosis. Early or prophylactic gastrectomy is contraindicated. However, if complications that require immediate surgical intervention arise, there should be no hesitation and the corresponding procedure should be performed.

Atomic layer deposition (ALD) for optical nanofabrication

Science.gov (United States)

Maula, Jarmo

2010-02-01

ALD is currently one of the most rapidly developing fields of thin film technology. Presentation gives an overview of ALD technology for optical film deposition, highlighting benefits, drawbacks and peculiarities of the ALD, especially compared to PVD. Viewpoint is practical, based on experience gained from tens of different applications over the last few decades. ALD is not competing, but enabling technology to provide coatings, which are difficult for traditional technologies. Examples of such cases are films inside of tubes; double side deposition on the substrate; large area accurate coatings; decorative coating for 3D parts; conformal coatings on high aspect ratio surfaces or inside porous structures. Novel materials can be easily engineered by making modifications on molecular level. ALD coats large surfaces effectively and fast. Opposite to common view, it actually provides high throughput (coated area/time), when used properly with a batch and/or in-line tools. It is possible to use ALD for many micrometers thick films or even produce thin parts with competitive cost. Besides optical films ALD provides large variety of features for nanofabrication. For example pin hole free films for passivation and barrier applications and best available films for conformal coatings like planarization or to improve surface smoothness. High deposition repeatability even with subnanometer film structures helps fabrication. ALD enters to production mostly through new products, not yet existing on the market and so the application IP field is reasonably open. ALD is an enabling, mature technology to fabricate novel optical materials and to open pathways for new applications.

Arsenic removal from acidic solutions with biogenic ferric precipitates.

Science.gov (United States)

Ahoranta, Sarita H; Kokko, Marika E; Papirio, Stefano; Özkaya, Bestamin; Puhakka, Jaakko A

2016-04-05

Treatment of acidic solution containing 5g/L of Fe(II) and 10mg/L of As(III) was studied in a system consisting of a biological fluidized-bed reactor (FBR) for iron oxidation, and a gravity settler for iron precipitation and separation of the ferric precipitates. At pH 3.0 and FBR retention time of 5.7h, 96-98% of the added Fe(II) precipitated (99.1% of which was jarosite). The highest iron oxidation and precipitation rates were 1070 and 28mg/L/h, respectively, and were achieved at pH 3.0. Subsequently, the effect of pH on arsenic removal through sorption and/or co-precipitation was examined by gradually decreasing solution pH from 3.0 to 1.6 (feed pH). At pH 3.0, 2.4 and 1.6, the highest arsenic removal efficiencies obtained were 99.5%, 80.1% and 7.1%, respectively. As the system had ferric precipitates in excess, decreased arsenic removal was likely due to reduced co-precipitation at pHremoves iron and arsenic from acidic solutions, indicating potential for mining wastewater treatment. Copyright © 2015 Elsevier B.V. All rights reserved.

The possibility of multi-layer nanofabrication via atomic force microscope-based pulse electrochemical nanopatterning

Science.gov (United States)

Kim, Uk Su; Morita, Noboru; Lee, Deug Woo; Jun, Martin; Park, Jeong Woo

2017-05-01

Pulse electrochemical nanopatterning, a non-contact scanning probe lithography process using ultrashort voltage pulses, is based primarily on an electrochemical machining process using localized electrochemical oxidation between a sharp tool tip and the sample surface. In this study, nanoscale oxide patterns were formed on silicon Si (100) wafer surfaces via electrochemical surface nanopatterning, by supplying external pulsed currents through non-contact atomic force microscopy. Nanoscale oxide width and height were controlled by modulating the applied pulse duration. Additionally, protruding nanoscale oxides were removed completely by simple chemical etching, showing a depressed pattern on the sample substrate surface. Nanoscale two-dimensional oxides, prepared by a localized electrochemical reaction, can be defined easily by controlling physical and electrical variables, before proceeding further to a layer-by-layer nanofabrication process.

Pitting corrosion resistance of high alloy OCTG in ferric chloride solution

International Nuclear Information System (INIS)

Masamura, K.; Yamamoto, S.; Matsushima, I.

1986-01-01

The effects of alloying elements and precipitated phases on the corrosion rate of high alloy OCTG in the ferric chloride solution have been evaluated. The corrosion rate of Fe-Cr-Ni-Mo alloys without precipitated phases, e.g. carbides and sigma phase, can be estimated from the composition using the following equation: log(C.R.)=-0.144xPRE-7690/(273+T)+28.6 where C.R. is the corrosion rate in g/m/sup 2//hr; PRE is Cr+3Mo+16N in percent and T is the test temperature in 0 C. The activation energies of the ferric chloride test are almost the same regardless of PRE or Ni content when no detrimental phase precipitates. When carbides or the sigma phase precipitate, the corrosion rate is higher and the activation energy is lowered. This suggests that secondary phases give preferential sites for initiation of pitting corrosion

A case of osteomalacia due to deranged mineral balance caused by saccharated ferric oxide and short-bowel syndrome: A case report.

Science.gov (United States)

Nomoto, Hiroshi; Miyoshi, Hideaki; Nakamura, Akinobu; Nagai, So; Kitao, Naoyuki; Shimizu, Chikara; Atsumi, Tatsuya

2017-09-01

Saccharated ferric oxide has been shown to lead to elevation of fibroblast growth factor 23, hypophosphatemia, and, consequently, osteomalacia. Moreover, mineral imbalance is often observed in patients with short-bowel syndrome to some degree. A 62-year-old woman with short-bowel syndrome related with multiple resections of small intestines due to Crohn disease received regular intravenous administration of saccharated ferric oxide. Over the course of treatment, she was diagnosed with tetany, which was attributed to hypocalcemia. Additional assessments of the patient revealed not only hypocalcemia, but also hypophosphatemia, hypomagnesemia, osteomalacia, and a high concentration of fibroblast growth factor 23 (314 pg/mL). We diagnosed her with mineral imbalance-induced osteomalacia due to saccharated ferric oxide and short-bowel syndrome. Magnesium replacement therapy and discontinuation of saccharated ferric oxide alone. These treatments were able to normalize her serum mineral levels and increase her bone mineral density. This case suggests that adequate evaluation of serum minerals, including phosphate and magnesium, during saccharated ferric oxide administration may be necessary, especially in patients with short-bowel syndrome.

A micro-spectroscopy study on the influence of chemical residues from nanofabrication on the nitridation chemistry of Al nanopatterns

Energy Technology Data Exchange (ETDEWEB)

Qi, B., E-mail: bing@raunvis.hi.is [Physics Department, Science Institute, University of Iceland, Dunhaga 3,107 Reykjavik (Iceland); Olafsson, S. [Physics Department, Science Institute, University of Iceland, Dunhaga 3,107 Reykjavik (Iceland); Zakharov, A.A. [MAX-lab, Lund University, S-22100 Lund (Sweden); Agnarsson, B. [Physics Department, Science Institute, University of Iceland, Dunhaga 3,107 Reykjavik (Iceland); Department of Applied Physics, Chalmers University of Technology, S-41296 Gothenburg (Sweden); Gislason, H.P. [Physics Department, Science Institute, University of Iceland, Dunhaga 3,107 Reykjavik (Iceland); Goethelid, M. [Materialfysik, MAP, ICT, KTH, ELECTRUM 229, 16440 Kista (Sweden)

2012-03-01

We applied spatially resolved photoelectron spectroscopy implemented with an X-ray photoemission electron microscopy (XPEEM) using soft X-ray synchrotron radiation to identify the compositional and morphological inhomogeneities of a SiO{sub 2}/Si substrate surface nanopatterned with Al before and after nitridation. The nanofabrication was conducted by a polymethylmethacrylate (PMMA)-based e-beam lithography and a fluorine-based reactive ion etching (RIE), followed by Al metalization and acetone lift-off. Three types of chemical residues were identified before nitridation: (1) fluorocarbons produced and accumulated mainly during RIE process on the sidewalls of the nanopatterns; (2) a thick Al-bearing PMMA layer and/or (3) a thin PMMA residue layer owing to unsuccessful or partial lift-off of the e-beam unexposed PMMA between the nanopatterns. The fluorocarbons actively influenced the surface chemical composition of the nanopatterns by forming Al-F compounds. After nitridation, in the PMMA residue-free area, the Al-F compounds on the sidewalls were decomposed and transformed to AlN. The PMMA residues between the nanopatterns had no obvious influence on the surface chemical composition and nitridation properties of the Al nanopatterns. They were only partially decomposed by the nitridation. The regional surface morphology of the nanopatterns revealed by the secondary electron XPEEM was consistent with the scanning electron microscopy results.

THE SURFACE PHOTOCHEMISTRY OF PROCYMIDONE IN PRESENCE OF AMMONIUM FERRIC CITRATE

Directory of Open Access Journals (Sweden)

Ivan Osipov

2015-12-01

Full Text Available Procymidone was chosen as the model compound and its phototransformation was followed under sunlight irradiation. The main photodegradation products on silica is 3,5-dichloroaniline and 3,5-diclorphenilisocyanate. The use of ammonium ferric citrate enhances the degradation of the procymidone.

Radium behaviour during ferric oxi-hydroxides crystallization

International Nuclear Information System (INIS)

Bassot, S.; Stammose, D.; Benitah, S.

2004-01-01

In uranium mill tailings, oxides and oxi-hydroxides are responsible of about 70% of the radium immobilization, half being associated to amorphous forms (mainly hydrous ferric oxides and hydrous manganese oxides). With time, crystallization of these amorphous forms can occur, inducing a redistribution of radium between solid and solution. If the amount of mobile radium increases, the impact of these tailings on the environment may become significant. The aim of this study is to determine the amount of radium released in solution during the crystallization process of hydrous ferric oxide (HFO). The transformation of Ra-HFO co-precipitate in crystallized forms (goethite, hematite, is studied by ageing at 40 deg C for different solution compositions. Both solids and solutions are sampled for different times and analysed. The solid evolution is followed by specific area measurements (about 250 m2/g for HFO and about 10-20 m 2 /g for crystallized form) and by determination of the amorphous fraction according to a selective extraction procedure. The solutions were analysed for 226 radium activity, iron concentration and pH. In order to discriminate the part of radium included in the solid and the part of radium fixed on the solid surface, radium sorption onto HFO and crystallized forms is studied as a function of pH. The modelling of the sorption curves with JCHESS 2.0 code allow to point out the mechanisms responsible of the 226-radium distribution between solid and solution during the crystallization process of HFO. (author)

Reduction of costs for anemia-management drugs associated with the use of ferric citrate

Directory of Open Access Journals (Sweden)

Thomas A

2014-05-01

Full Text Available Anila Thomas,1 Leif E Peterson2 1Clinical Pharmacy Services, Houston Methodist Hospital, Houston, TX, USA; 2Center for Biostatistics, Houston Methodist Research Institute, Houston, TX, USA Background: Ferric citrate is a novel phosphate binder which has the potential to reduce usage of erythropoietin-stimulating agents (ESAs and intravenous (IV iron used for anemia management during hemodialysis (HD among patients with end-stage renal disease (ESRD. Currently, the potential health care cost savings on a national scale due to the use of ferric citrate in ESRD are undetermined. Methods: Per-patient-per-year costs of ESAs (Epogen® and Aranesp® [Amgen Inc., CA, USA] and IV iron (Venofer® [American Regent, Inc., NY, USA] and Ferrlecit® [Sanofi US, Bridgewater, NJ, USA] were based on RED BOOK™ (Truven Health Analytics New York, NY, USA costs combined with the Centers for Medicare and Medicaid Services (CMS base rate and actual usage in 2011 for the four drugs. The annual number of outpatients undergoing HD in the US was based on frequencies reported by the USRDS (United States Renal Data System. Monte Carlo uncertainty analysis was performed to determine total annual costs and cost reduction based on ferric citrate usage. Results: Total annual cost of ESAs and IV iron for anemia management in ESRD determined by Monte Carlo analysis assuming CMS base rate value was 5.127 (3.664–6.260 billion USD. For actual utilization in 2011, total annual cost of ESAs and IV iron was 3.981 (2.780–4.930 billion USD. If ferric citrate usage reduced ESA utilization by 20% and IV iron by 40%, then total cost would be reduced by 21.2% to 4.038 (2.868–4.914 billion USD for the CMS base rate, and by 21.8% to 3.111 (2.148–3.845 billion USD, based on 2011 actual utilization. Conclusion: It is likely that US health care costs for anemia-management drugs associated with ESRD among HD patients can be reduced by using ferric citrate as a phosphate binder. Keywords

Novel approach to zinc removal from circum-neutral mine waters using pelletised recovered hydrous ferric oxide.

Science.gov (United States)

Mayes, William M; Potter, Hugh A B; Jarvis, Adam P

2009-02-15

Data are presented which evaluate the performance of a pilot-scale treatment system using pelletised hydrous ferric oxide (HFO; a waste stream from coal mine water treatment) as a high surface area sorbent for removing zinc (Zn) from a metal mine water discharge in the North Pennines Orefield, UK. Over a 10-month period the system removed Zn at mean area- and volume-adjusted removal rates of 3.7 and 8.1gm(-3)day(-1), respectively, with a mean treatment efficiency of 32% at a low mean residence time of 49min. There were seasonal effects in Zn removal owing to establishment and dieback of algae in the treatment tank. This led to increased Zn uptake in early summer months followed by slight Zn release upon algae senescence. In addition to these biosorptive processes, the principal sinks for Zn appear to be (1) sorption onto the HFO surface, and (2) precipitation with calcite-dominated secondary minerals. The latter were formed as a product of dissolution of portlandite in the cement binder and calcium recarbonation. Further optimisation of the HFO pelletisation process holds the possibility for providing a low-cost, low footprint treatment option for metal rich mine waters, in addition to a valuable after-use for recovered HFO from coal mine water treatment facilities.

Fabrication and characterization of nanostructured metallic arrays with multi-shapes in monolayer and bilayer

Energy Technology Data Exchange (ETDEWEB)

Zhu Shaoli, E-mail: slzhu@ntu.edu.s [Nanyang Technological University, School of Electronic and Electrical Engineering (Singapore); Fu Yongqi [University of Electronic Science and Technology of China, School of Physical Electronics (China)

2010-06-15

Fabrication and characterization of nanostructured metallic arrays with different shapes in monolayer and bilayer were presented in this article. Nano-rhombic, nano-hexagon, and nano-column metallic arrays with the tunable shapes and in-plane dimensions were fabricated by means of vertical reactive ion etching and nanosphere lithography. The nanosize range of nanoparticles is from 50 to 300 nm. Optical characterization of these arrays was performed experimentally by spectroscopy. Specifically, we compared spectra width at site of full width at half maximum (FWHM) of the measured extinction spectra in the visible range to that of the traditional hexagonal-arranged triangular nanoparticles. The results show that the combination of vertical reactive ion etching and nanosphere lithography approach yields as tunable masks and provides an easy way for a flexible nanofabrication. These metallic arrays have narrower FWHM of the spectra which makes them potential applications in biosensors, data storage, and bioreactors.

Supramolecular Ferric Porphyrins as Cyanide Receptors in Aqueous Solution

Science.gov (United States)

2011-01-01

All fundamental data about binding of the cyanide to a supramolecular complex composed of a per-O-methylated β-cyclodextrin dimer having an imidazole linker (Im3CD) and an anionic ferric porphyrin (Fe(III)TPPS) indicate that the Fe(III)TPPS/Im3CD complex is much better as an cyanide receptor in vivo than hydroxocobalamin, whose cyanide binding ability is lowered by its strong binding to serum proteins in the blood. PMID:24900285

Highly selective and sensitive fluorogenic ferric probes based on aggregation-enhanced emission with - SiMe3 substituted polybenzene

Science.gov (United States)

Wang, Xuefeng; Wang, Hua; Jiang, Qin; Lee, Yong-Ill; Feng, Shengyu; Liu, Hong-Guo

2018-01-01

In this study, thiophene was linked to polybenzene to generate novel fluorescent probes, namely 3,4-diphenyl-2,5-di(2-thienyl)phenyl-trimethylsilane (DPTB-TMS) with a - SiMe3 substituent and 3,4-diphenyl-2,5-di(2-thienyl)phenyl (DPTB) without the - SiMe3 substituent, respectively. Both of the two compounds exhibit aggregation-enhanced emission (AEE) properties in tetrahydrofuran/water mixtures due to restricted intramolecular rotation of the peripheral groups, which make the two compounds good candidates for the detection of Fe3 + ions in aqueous-based solutions. The fluorescence intensity of the two compounds decreases immediately and obviously upon addition of a trace amount of Fe3 +, and decreases continuously as the amount of Fe3 + increases. The fluorescence was quenched to 92% of its initial intensity when the amount of Fe3 + ions reached 6 μmol for DPTB-TMS and to 80% for DPTB in the systems, indicating that the compound with the - SiMe3 group is a more effective probe. The detection limit was found to be 1.17 μM (65 ppb). The detection mechanism is proposed to be static quenching. DPTB-TMS is highly efficient for the detection of ferric ions even in the presence of other metal ions. In addition, the method is also successfully applied to the detection of ferric ions in water, blood serum, or solid films. This indicates that these polybenzene compounds can be applied as low-cost, high selectivity, and high efficiency Fe3 + probes in water or in clinical applications.

Real-time monitoring of arsenic filtration by granular ferric hydroxide

International Nuclear Information System (INIS)

Fleming, D.E.B.; Eddy, I.S.; Gherase, M.R.; Gibbons, M.K.; Gagnon, G.A.

2008-01-01

Full text: Contamination of drinking water by arsenic is a serious public health issue in many parts of the world. One recent approach to this problem has been to filter out arsenic by use of granular ferric hydroxide (GFH), an adsorbent developed specifically for the selective removal of arsenic from water. Previous studies have documented the efficiency and high treatment capacity of this approach. We present a novel X-ray fluorescence method to monitor the accumulation of arsenic within a specially designed GFH column, as both a function of time (or water volume) and location along the column. Using a miniature X-ray tube and silicon PiN diode detector, X-ray fluorescence is used to detect characteristic X-rays of arsenic excited from within the GFH. Trials were performed using a water flow rate of approximately 1.5 litres per hour, with an added arsenic concentration of approximately 1000 μg per litre. In this paper, trial results are presented and potential applications described. Characteristic arsenic Kα X-ray peak area as a function of time, as measured at various locations along a granular ferric hydroxide (GFH) water filtration column

Ferric and cobaltous hydroacid complexes for forward osmosis (FO) processes

KAUST Repository

Ge, Qingchun; Fu, Fengjiang; Chung, Neal Tai-Shung

2014-01-01

Cupric and ferric hydroacid complexes have proven their advantages as draw solutes in forward osmosis in terms of high water fluxes, negligible reverse solute fluxes and easy recovery (Ge and Chung, 2013. Hydroacid complexes: A new class of draw solutes to promote forward osmosis (FO) processes. Chemical Communications 49, 8471-8473.). In this study, cobaltous hydroacid complexes were explored as draw solutes and compared with the ferric hydroacid complex to study the factors influencing their FO performance. The solutions of the cobaltous complexes produce high osmotic pressures due to the presence of abundant hydrophilic groups. These solutes are able to dissociate and form a multi-charged anion and Na+ cations in water. In addition, these complexes have expanded structures which lead to negligible reverse solute fluxes and provide relatively easy approaches in regeneration. These characteristics make the newly synthesized cobaltous complexes appropriate as draw solutes. The FO performance of the cobaltous and ferric-citric acid (Fe-CA) complexes were evaluated respectively through cellulose acetate membranes, thin-film composite membranes fabricated on polyethersulfone supports (referred as TFC-PES), and polybenzimidazole and PES dual-layer (referred as PBI/PES) hollow fiber membranes. Under the conditions of DI water as the feed and facing the support layer of TFC-PES FO membranes (PRO mode), draw solutions at 2.0M produced relatively high water fluxes of 39-48 LMH (Lm-2hr-1) with negligible reverse solute fluxes. A water flux of 17.4 LMH was achieved when model seawater of 3.5wt.% NaCl replaced DI water as the feed and 2.0M Fe-CA as the draw solution under the same conditions. The performance of these hydroacid complexes surpasses those of the synthetic draw solutes developed in recent years. This observation, along with the relatively easy regeneration, makes these complexes very promising as a novel class of draw solutes. © 2014 Elsevier Ltd.

Ferric and cobaltous hydroacid complexes for forward osmosis (FO) processes

KAUST Repository

Ge, Qingchun

2014-07-01

Cupric and ferric hydroacid complexes have proven their advantages as draw solutes in forward osmosis in terms of high water fluxes, negligible reverse solute fluxes and easy recovery (Ge and Chung, 2013. Hydroacid complexes: A new class of draw solutes to promote forward osmosis (FO) processes. Chemical Communications 49, 8471-8473.). In this study, cobaltous hydroacid complexes were explored as draw solutes and compared with the ferric hydroacid complex to study the factors influencing their FO performance. The solutions of the cobaltous complexes produce high osmotic pressures due to the presence of abundant hydrophilic groups. These solutes are able to dissociate and form a multi-charged anion and Na+ cations in water. In addition, these complexes have expanded structures which lead to negligible reverse solute fluxes and provide relatively easy approaches in regeneration. These characteristics make the newly synthesized cobaltous complexes appropriate as draw solutes. The FO performance of the cobaltous and ferric-citric acid (Fe-CA) complexes were evaluated respectively through cellulose acetate membranes, thin-film composite membranes fabricated on polyethersulfone supports (referred as TFC-PES), and polybenzimidazole and PES dual-layer (referred as PBI/PES) hollow fiber membranes. Under the conditions of DI water as the feed and facing the support layer of TFC-PES FO membranes (PRO mode), draw solutions at 2.0M produced relatively high water fluxes of 39-48 LMH (Lm-2hr-1) with negligible reverse solute fluxes. A water flux of 17.4 LMH was achieved when model seawater of 3.5wt.% NaCl replaced DI water as the feed and 2.0M Fe-CA as the draw solution under the same conditions. The performance of these hydroacid complexes surpasses those of the synthetic draw solutes developed in recent years. This observation, along with the relatively easy regeneration, makes these complexes very promising as a novel class of draw solutes. © 2014 Elsevier Ltd.

Parallel computation with molecular-motor-propelled agents in nanofabricated networks.

Science.gov (United States)

Nicolau, Dan V; Lard, Mercy; Korten, Till; van Delft, Falco C M J M; Persson, Malin; Bengtsson, Elina; Månsson, Alf; Diez, Stefan; Linke, Heiner; Nicolau, Dan V

2016-03-08

The combinatorial nature of many important mathematical problems, including nondeterministic-polynomial-time (NP)-complete problems, places a severe limitation on the problem size that can be solved with conventional, sequentially operating electronic computers. There have been significant efforts in conceiving parallel-computation approaches in the past, for example: DNA computation, quantum computation, and microfluidics-based computation. However, these approaches have not proven, so far, to be scalable and practical from a fabrication and operational perspective. Here, we report the foundations of an alternative parallel-computation system in which a given combinatorial problem is encoded into a graphical, modular network that is embedded in a nanofabricated planar device. Exploring the network in a parallel fashion using a large number of independent, molecular-motor-propelled agents then solves the mathematical problem. This approach uses orders of magnitude less energy than conventional computers, thus addressing issues related to power consumption and heat dissipation. We provide a proof-of-concept demonstration of such a device by solving, in a parallel fashion, the small instance {2, 5, 9} of the subset sum problem, which is a benchmark NP-complete problem. Finally, we discuss the technical advances necessary to make our system scalable with presently available technology.

Metal-insulator-metal diodes with sub-nanometre surface roughness for energy-harvesting applications

KAUST Repository

Khan, A.A.; Jayaswal, Gaurav; Gahaffar, F.A.; Shamim, Atif

2017-01-01

For ambient radio-frequency (RF) energy harvesting, the available power levels are quite low, and it is highly desirable that the rectifying diodes do not consume any power at all. Contrary to semiconducting diodes, a tunnelling diode – also known as a metal-insulator-metal (MIM) diode – can provide zero-bias rectification, provided the two metals have different work functions. This could result in a complete passive rectenna system. Despite great potential, MIM diodes have not been investigated much in the GHz-frequency regime due to challenging nano-fabrication requirements. In this work, we investigate zero-bias MIM diodes for RF energy-harvesting applications. We studied the surface roughness issue for the bottom metal of the MIM diode for various deposition techniques such as sputtering, atomic layer deposition (ALD) and electron-beam (e-beam) evaporation for crystalline metals as well as for an amorphous alloy, namely ZrCuAlNi. A surface roughness of sub-1nm has been achieved for both the crystalline metals as well as the amorphous alloy, which is vital for the reliable operation of the MIM diode. An MIM diode comprising of a Ti-ZnO-Pt combination yields a zero-bias responsivity of 0.25V−1 and a dynamic resistance of 1200Ω. Complete RF characterisation has been performed by integrating the MIM diode with a coplanar waveguide transmission line. The input impedance varies from 100Ω to 50Ω in the frequency range of between 2GHz and 10GHz, which can be easily matched to typical antenna impedances in this frequency range. Finally, a rectified DC voltage of 4.7mV is obtained for an incoming RF power of 0.4W at zero bias. These preliminary results of zero-bias rectification indicate that complete, passive rectennas (a rectifier and antenna combination) are feasible with further optimisation of MIM devices.

Metal-insulator-metal diodes with sub-nanometre surface roughness for energy-harvesting applications

KAUST Repository

Khan, A.A.

2017-07-27

For ambient radio-frequency (RF) energy harvesting, the available power levels are quite low, and it is highly desirable that the rectifying diodes do not consume any power at all. Contrary to semiconducting diodes, a tunnelling diode – also known as a metal-insulator-metal (MIM) diode – can provide zero-bias rectification, provided the two metals have different work functions. This could result in a complete passive rectenna system. Despite great potential, MIM diodes have not been investigated much in the GHz-frequency regime due to challenging nano-fabrication requirements. In this work, we investigate zero-bias MIM diodes for RF energy-harvesting applications. We studied the surface roughness issue for the bottom metal of the MIM diode for various deposition techniques such as sputtering, atomic layer deposition (ALD) and electron-beam (e-beam) evaporation for crystalline metals as well as for an amorphous alloy, namely ZrCuAlNi. A surface roughness of sub-1nm has been achieved for both the crystalline metals as well as the amorphous alloy, which is vital for the reliable operation of the MIM diode. An MIM diode comprising of a Ti-ZnO-Pt combination yields a zero-bias responsivity of 0.25V−1 and a dynamic resistance of 1200Ω. Complete RF characterisation has been performed by integrating the MIM diode with a coplanar waveguide transmission line. The input impedance varies from 100Ω to 50Ω in the frequency range of between 2GHz and 10GHz, which can be easily matched to typical antenna impedances in this frequency range. Finally, a rectified DC voltage of 4.7mV is obtained for an incoming RF power of 0.4W at zero bias. These preliminary results of zero-bias rectification indicate that complete, passive rectennas (a rectifier and antenna combination) are feasible with further optimisation of MIM devices.

In Situ Structural Characterization of Ferric Iron Dimers in Aqueous Solutions

DEFF Research Database (Denmark)

Zhu, Mengqiang; Puls, Brendan W.; Frandsen, Cathrine

2013-01-01

The structure of ferric iron (Fe3+) dimers in aqueous solutions has long been debated. In this work, we have determined the dimer structure in situ in aqueous solutions using extended X-ray absorption fine structure (EXAFS) spectroscopy. An Fe K-edge EXAFS analysis of 0.2 M ferric nitrate solutions...... at pH 1.28–1.81 identified a Fe–Fe distance at ∼3.6 Å, strongly indicating that the dimers take the μ-oxo form. The EXAFS analysis also indicates two short Fe–O bonds at ∼1.80 Å and ten long Fe–O bonds at ∼2.08 Å, consistent with the μ-oxo dimer structure. The scattering from the Fe–Fe paths interferes...... confirmed by Mössbauer analyses of analogous quick frozen solutions. This work also explores the electronic structure and the relative stability of the μ-oxo dimer in a comparison to the dihydroxo dimer using density function theory (DFT) calculations. The identification of such dimers in aqueous solutions...

Nanomanipulation and nanofabrication with multi-probe scanning tunneling microscope: from individual atoms to nanowires.

Science.gov (United States)

Qin, Shengyong; Kim, Tae-Hwan; Wang, Zhouhang; Li, An-Ping

2012-06-01

The wide variety of nanoscale structures and devices demands novel tools for handling, assembly, and fabrication at nanoscopic positioning precision. The manipulation tools should allow for in situ characterization and testing of fundamental building blocks, such as nanotubes and nanowires, as they are built into functional devices. In this paper, a bottom-up technique for nanomanipulation and nanofabrication is reported by using a 4-probe scanning tunneling microscope (STM) combined with a scanning electron microscope (SEM). The applications of this technique are demonstrated in a variety of nanosystems, from manipulating individual atoms to bending, cutting, breaking carbon nanofibers, and constructing nanodevices for electrical characterizations. The combination of the wide field of view of SEM, the atomic position resolution of STM, and the flexibility of multiple scanning probes is expected to be a valuable tool for rapid prototyping in the nanoscience and nanotechnology.

Comparative Evaluation of Aluminum Sulfate and Ferric Sulfate-Induced Coagulations as Pretreatment of Microfiltration for Treatment of Surface Water

Directory of Open Access Journals (Sweden)

Yali Song

2015-06-01

Full Text Available Two coagulants, aluminum sulfate and ferric chloride, were tested to reduce natural organic matter (NOM as a pretreatment prior to polyvinylidene fluoride (PVDF microfiltration (MF membranes for potable water treatment. The results showed that the two coagulants exhibited different treatment performance in NOM removal. Molecular weight (MW distributions of NOM in the tested surface raw water were concentrated at 3–5 kDa and approximately 0.2 kDa. Regardless of the coagulant species and dosages, the removal of 0.2 kDa NOM molecules was limited. In contrast, NOM at 3–5 kDa were readily removed with increasing coagulant dosages. In particular, aluminum sulfate favorably removed NOM near 5 kDa, whereas ferric chloride tended to reduce 3 kDa organic substances. Although aluminum sulfate and ferric chloride could improve the flux of the ensuing MF treatment, the optimal coagulant dosages to achieve effective pretreatment were different: 2–30 mg/L for aluminum sulfate and >15 mg/L for ferric chloride. The scanning electron microscope (SEM image of the membrane-filtered coagulated raw water showed that coagulation efficiency dramatically affected membrane flux and that good coagulation properties can reduce membrane fouling.

Molecular and phenotypic characterization of transgenic soybean expressing the Arabidopsis ferric chelate reductase gene, FRO2.

Science.gov (United States)

Vasconcelos, Marta; Eckert, Helene; Arahana, Venancio; Graef, George; Grusak, Michael A; Clemente, Tom

2006-10-01

Soybean (Glycine max Merr.) production is reduced under iron-limiting calcareous soils throughout the upper Midwest regions of the US. Like other dicotyledonous plants, soybean responds to iron-limiting environments by induction of an active proton pump, a ferric iron reductase and an iron transporter. Here we demonstrate that heterologous expression of the Arabidopsis thaliana ferric chelate reductase gene, FRO2, in transgenic soybean significantly enhances Fe(+3) reduction in roots and leaves. Root ferric reductase activity was up to tenfold higher in transgenic plants and was not subjected to post-transcriptional regulation. In leaves, reductase activity was threefold higher in the transgenic plants when compared to control. The enhanced ferric reductase activity led to reduced chlorosis, increased chlorophyll concentration and a lessening in biomass loss in the transgenic events between Fe treatments as compared to control plants grown under hydroponics that mimicked Fe-sufficient and Fe-deficient soil environments. However, the data indicate that constitutive FRO2 expression under non-iron stress conditions may lead to a decrease in plant productivity as reflected by reduced biomass accumulation in the transgenic events under non-iron stress conditions. When grown at Fe(III)-EDDHA levels greater than 10 microM, iron concentration in the shoots of transgenic plants was significantly higher than control. The same observation was found in the roots in plants grown at iron levels higher than 32 microM Fe(III)-EDDHA. These results suggest that heterologous expression of an iron chelate reductase in soybean can provide a route to alleviate iron deficiency chlorosis.

Laser applications in nanotechnology: nanofabrication using laser ablation and laser nanolithography

International Nuclear Information System (INIS)

Makarov, G N

2013-01-01

The fact that nanoparticles and nanomaterials have fundamental properties different both from their constituent atoms or molecules and from their bulk counterparts has stimulated great interest, both theoretical and practical, in nanoparticles and nanoparticle-based assemblies (functional materials), with the result that these structures have become the subject of explosive research over the last twenty years or so. A great deal of progress in this field has relied on the use of lasers. In this paper, the directions followed and results obtained in laser nanotechnology research are reviewed. The parameters, properties, and applications of nanoparticles are discussed, along with the physical and chemical methods for their fabrication and investigation. Nanofabrication applications of and fundamental physical principles behind laser ablation and laser nanolithography are discussed in detail. The applications of laser radiation are shown to range from fabricating, melting, and evaporating nanoparticles to changing their shape, structure, size, and size distribution, through studying their dynamics and forming them into periodic arrays and various structures and assemblies. The historical development of research on nanoparticles and nanomaterials and the application of laser nanotechnology in various fields are briefly reviewed. (reviews of topical problems)

Photoexcitation dynamics of nitric oxide bound ferric myoglobin probed by femtosecond IR spectroscopy

Directory of Open Access Journals (Sweden)

Park Jaehun

2013-03-01

Full Text Available Time-resolved vibrational spectra show that photolysis quantum yield of NO bound ferric myoglobin is smaller than 0.86, the deligated NO geminately rebinds with subnanosecond time scale, and the rebinding kinetics depends on protein conformation.

Ferric iron remediation and stabilisation (firs) - developing a new robust electrokinetic remediation technique for heavy metal and radionuclide contaminated sites

International Nuclear Information System (INIS)

Faulkner, D.; Hopkinson, L.; Cundy, A.

2005-01-01

Electrokinetic remediation is an emerging technology that has generated considerable interest as a technique for the in-situ remediation of contaminated clay-rich soils and sediments. Despite promising experimental results, however, at present there is no standardised universal electrokinetic soil/sediment remediation approach. Many of the current technologies are technically complex and energy intensive, and geared towards the removal of 90% or more of specific contaminants, under very specific field or laboratory-based conditions. However, in the real environment a low-tech, low-energy contaminant reduction / containment technique may be more appropriate and realistic. Such a technique, FIRS (Ferric Iron Remediation and Stabilisation), is discussed here. The FIRS technique involves the application of a low magnitude (typically less than 0.2 V/cm) direct electric potential between two or more sacrificial, iron-rich, electrodes emplaced either side of a contaminated soil or sediment. The electric potential is used to generate a strong pH (and Eh) gradient within the soil column (pH 2 - 13), which acts to re-mobilize contaminants in the treated soil, and force the precipitation of an impermeable, sorptive iron-rich barrier or 'pan' in the soil between the electrodes. Geochemical data from bench-scale treatment cells indicate that the FIRS technique can significantly reduce the concentration of a range of heavy metals and radionuclides in contaminated soils, by remobilization of contaminants followed by precipitation on, or around, the iron-rich barrier generated by the technique. In addition, arsenic seems highly amenable to the FIRS treatment, due to its solubility under the high pH conditions generated near to the cathode, and its marked geochemical affinity with the freshly precipitated iron oxides and oxy-hydroxides in the iron barrier. Geotechnical tests indicate that the iron barrier produced by the technique is practically impervious (permeability 10 -9 m

Intravenous ferric carboxymaltose accelerates erythropoietic recovery from experimental malarial anemia

DEFF Research Database (Denmark)

Maretty, Lasse; Sharp, Rebecca Emilie; Andersson, Mikael

2012-01-01

Iron restriction has been proposed as a cause of erythropoietic suppression in malarial anemia; however, the role of iron in malaria remains controversial, because it may increase parasitemia. To investigate the role of iron-restricted erythropoiesis, A/J mice were infected with Plasmodium chabaudi...... use of iron therapy in malaria and show the need for trials of intravenous ferric carboxymaltose as an adjunctive treatment for severe malarial anemia....

Comparison of Water Turbidity Removal Efficiencies of Descurainia Sophia Seed Extract and Ferric chloride

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Mazyar Peyda

2016-03-01

Full Text Available Background Turbidity removal using inorganic coagulants such as iron and aluminum salts in water treatment processes causes environmental and human health concern. Historically, the use of natural coagulant to purify turbid water has been practiced for a long time. Recent research indicates that Descurainia Sophia seed can be effectively used as a natural coagulant to remove water turbidity. Method: In this work, turbidity removal efficiency of Descurainia Sophia seed extract was compared with Ferric chloride. Experiments were performed in laboratory scale. The coagulation experiments were done with kaolin as a model soil to produce turbidity in distilled water. The turbidity removal efficiency of Descurainia Sophia seed extract and Ferric chloride were conducted with jar test apparatus. In all experiments, initial turbidity was kept constant 100(NTU. Optimum combination of independent variables was used to compare two different types of coagulants. Result: The obtained results showed that Ferric chloride could remove 89.75% of the initial turbidity, while in case of Descurainia Sophia this value was 43.13%. The total organic carbon (TOC analysis of the treated water using seed extract showed an increased concentration of TOC equal to 0.99 mg/L. Conclusions: This research has shown that Descurainia Sophia seed extract has an acceptable potential in the coagulation/flocculation process to treat turbid water.

Metal Oxide Decomposition In Hydrothermal Alkaline Sodium Phosphate Solutions

Energy Technology Data Exchange (ETDEWEB)

S.E. Ziemniak

2003-09-24

Alkaline hydrothermal solutions of sodium orthophosphate (2.15 < Na/P < 2.75) are shown to decompose transition metal oxides into two families of sodium-metal ion-(hydroxy)phosphate compounds. Equilibria for these reactions are quantified by determining phosphate concentration-temperature thresholds for decomposition of five oxides in the series: Ti(IV), Cr(III), Fe(III, II), Ni(II) and Zn(II). By application of a computational chemistry method General Utility Lattice Program (GULP), it is demonstrated that the unique non-whole-number Na/P molar ratio of sodium ferric hydroxyphosphate is a consequence of its open-cage structure in which the H{sup +} and excess Na{sup +} ions are located.

Ferric reductase genes involved in high-affinity iron uptake are differentially regulated in yeast and hyphae of Candida albicans.

Science.gov (United States)

Jeeves, Rose E; Mason, Robert P; Woodacre, Alexandra; Cashmore, Annette M

2011-09-01

The pathogenic yeast Candida albicans possesses a reductive iron uptake system which is active in iron-restricted conditions. The sequestration of iron by this mechanism initially requires the reduction of free iron to the soluble ferrous form, which is catalysed by ferric reductase proteins. Reduced iron is then taken up into the cell by a complex of a multicopper oxidase protein and an iron transport protein. Multicopper oxidase proteins require copper to function and so reductive iron and copper uptake are inextricably linked. It has previously been established that Fre10 is the major cell surface ferric reductase in C. albicans and that transcription of FRE10 is regulated in response to iron levels. We demonstrate here that Fre10 is also a cupric reductase and that Fre7 also makes a significant contribution to cell surface ferric and cupric reductase activity. It is also shown, for the first time, that transcription of FRE10 and FRE7 is lower in hyphae compared to yeast and that this leads to a corresponding decrease in cell surface ferric, but not cupric, reductase activity. This demonstrates that the regulation of two virulence determinants, the reductive iron uptake system and the morphological form of C. albicans, are linked. Copyright © 2011 John Wiley & Sons, Ltd.

SPECTROPHOTOMETRIC ASSESSMENT OF FERRIC REDUCING POWER OF THE INSTANT COFFEE

OpenAIRE

Tsiupko, T. G.; Tishchenko, E. A.; Voronova, O. B.

2016-01-01

The methods of antioxidant activity determination of foodstuffs using different indicator systems were discussed. The investigation of ferric reducing power (FRP) of coffee and its individual phenolic components such as chlorogenic (CGA), caffeic (СА), ferulic (FA), gallic (GA), vanillic (VA), protocatechuic (PCA) and uric (UA) acids as well as quercetin (Qu) and catechol (C) using the spectrophotometric method with Fe(III) - o-Phen indicator system was carried out. It was shown that the sens...

Inhibition of cellulase-catalyzed lignocellulosic hydrolysis by iron and oxidative metal ions and complexes.

Science.gov (United States)

Tejirian, Ani; Xu, Feng

2010-12-01

Enzymatic lignocellulose hydrolysis plays a key role in microbially driven carbon cycling and energy conversion and holds promise for bio-based energy and chemical industries. Cellulases (key lignocellulose-active enzymes) are prone to interference from various noncellulosic substances (e.g., metal ions). During natural cellulolysis, these substances may arise from other microbial activities or abiotic events, and during industrial cellulolysis, they may be derived from biomass feedstocks or upstream treatments. Knowledge about cellulolysis-inhibiting reactions is of importance for the microbiology of natural biomass degradation and the development of biomass conversion technology. Different metal ions, including those native to microbial activity or employed for biomass pretreatments, are often tested for enzymatic cellulolysis. Only a few metal ions act as inhibitors of cellulases, which include ferrous and ferric ions as well as cupric ion. In this study, we showed inhibition by ferrous/ferric ions as part of a more general effect from oxidative (or redox-active) metal ions and their complexes. The correlation between inhibition and oxidation potential indicated the oxidative nature of the inhibition, and the dependence on air established the catalytic role that iron ions played in mediating the dioxygen inhibition of cellulolysis. Individual cellulases showed different susceptibilities to inhibition. It is likely that the inhibition exerted its effect more on cellulose than on cellulase. Strong iron ion chelators and polyethylene glycols could mitigate the inhibition. Potential microbiological and industrial implications of the observed effect of redox-active metal ions on enzymatic cellulolysis, as well as the prevention and mitigation of this effect in industrial biomass conversion, are discussed.

A top-down approach for fabricating three-dimensional closed hollow nanostructures with permeable thin metal walls

Directory of Open Access Journals (Sweden)

Carlos Angulo Barrios

2017-06-01

Full Text Available We report on a top-down method for the controlled fabrication of three-dimensional (3D, closed, thin-shelled, hollow nanostructures (nanocages on planar supports. The presented approach is based on conventional microelectronic fabrication processes and exploits the permeability of thin metal films to hollow-out polymer-filled metal nanocages through an oxygen-plasma process. The technique is used for fabricating arrays of cylindrical nanocages made of thin Al shells on silicon substrates. This hollow metal configuration features optical resonance as revealed by spectral reflectance measurements and numerical simulations. The fabricated nanocages were demonstrated as a refractometric sensor with a measured bulk sensitivity of 327 nm/refractive index unit (RIU. The pattern design flexibility and controllability offered by top-down nanofabrication techniques opens the door to the possibility of massive integration of these hollow 3D nano-objects on a chip for applications such as nanocontainers, nanoreactors, nanofluidics, nano-biosensors and photonic devices.

A top-down approach for fabricating three-dimensional closed hollow nanostructures with permeable thin metal walls.

Science.gov (United States)

Barrios, Carlos Angulo; Canalejas-Tejero, Víctor

2017-01-01

We report on a top-down method for the controlled fabrication of three-dimensional (3D), closed, thin-shelled, hollow nanostructures (nanocages) on planar supports. The presented approach is based on conventional microelectronic fabrication processes and exploits the permeability of thin metal films to hollow-out polymer-filled metal nanocages through an oxygen-plasma process. The technique is used for fabricating arrays of cylindrical nanocages made of thin Al shells on silicon substrates. This hollow metal configuration features optical resonance as revealed by spectral reflectance measurements and numerical simulations. The fabricated nanocages were demonstrated as a refractometric sensor with a measured bulk sensitivity of 327 nm/refractive index unit (RIU). The pattern design flexibility and controllability offered by top-down nanofabrication techniques opens the door to the possibility of massive integration of these hollow 3D nano-objects on a chip for applications such as nanocontainers, nanoreactors, nanofluidics, nano-biosensors and photonic devices.

Ferric carboxymaltose prevents recurrence of anemia in patients with inflammatory bowel disease

DEFF Research Database (Denmark)

Evstatiev, Rayko; Alexeeva, Olga; Bokemeyer, Bernd

2013-01-01

Iron-deficiency anemia is the most common systemic complication of inflammatory bowel diseases (IBD). Iron-deficiency anemia recurs frequently and rapidly after iron-replacement therapy in patients with IBD. We performed a randomized, placebo-controlled trial to determine if administration...... of ferric carboxymaltose (FCM) prevents anemia in patients with IBD and low levels of serum ferritin....

Application of granular ferric hydroxides for removal elevated concentrations of arsenic from mine waters

Science.gov (United States)

Szlachta, Małgorzata; Włodarczyk, Paweł; Wójtowicz, Patryk

2015-04-01

Arsenic is naturally occurring element in the environment. Over three hundred minerals are known to contain some form of arsenic and among them arsenopyrite is the most common one. Arsenic-bearing minerals are frequently associated with ores containing mined metals such as copper, tin, nickel, lead, uranium, zinc, cobalt, platinum and gold. In the aquatic environment arsenic is typically present in inorganic forms, mainly in two oxidation states (+5, +3). As(III) is dominant in more reduced conditions, whereas As(V) is mostly present in an oxidizing environment. However, due to certain human activities the elevated arsenic levels in aquatic ecosystems are arising to a serious environmental problem. High arsenic concentrations found in surface and groundwaters, in some regions originate from mining activities and ore processing. Therefore, the major concern of mining industry is to maintain a good quality of effluents discharged in large volumes. This requires constant monitoring of effluents quality that guarantee the efficient protection of the receiving waters and reacting to possible negative impact of contamination on local communities. A number of proven technologies are available for arsenic removal from waters and wastewaters. In the presented work special attention is given to the adsorption method as a technically feasible, commonly applied and effective technique for the treatment of arsenic rich mine effluents. It is know that arsenic has a strong affinity towards iron rich materials. Thus, in this study the granular ferric hydroxides (CFH 12, provided by Kemira Oyj, Finland) was applied to remove As(III) and As(V) from aqueous solutions. The batch adsorption experiments were carried out to assess the efficiency of the tested Fe-based material under various operating parameters, including composition of treated water, solution pH and temperature. The results obtained from the fixed bed adsorption tests demonstrated the benefits of applying granular

A novel role of the ferric reductase Cfl1 in cell wall integrity, mitochondrial function, and invasion to host cells in Candida albicans.

Science.gov (United States)

Yu, Qilin; Dong, Yijie; Xu, Ning; Qian, Kefan; Chen, Yulu; Zhang, Biao; Xing, Laijun; Li, Mingchun

2014-11-01

Candida albicans is an important opportunistic pathogen, causing both superficial mucosal infections and life-threatening systemic diseases. Iron acquisition is an important factor for pathogen-host interaction and also a significant element for the pathogenicity of this organism. Ferric reductases, which convert ferric iron into ferrous iron, are important components of the high-affinity iron uptake system. Sequence analyses have identified at least 17 putative ferric reductase genes in C. albicans genome. CFL1 was the first ferric reductase identified in C. albicans. However, little is known about its roles in C. albicans physiology and pathogenicity. In this study, we found that disruption of CFL1 led to hypersensitivity to chemical and physical cell wall stresses, activation of the cell wall integrity (CWI) pathway, abnormal cell wall composition, and enhanced secretion, indicating a defect in CWI in this mutant. Moreover, this mutant showed abnormal mitochondrial activity and morphology, suggesting a link between ferric reductases and mitochondrial function. In addition, this mutant displayed decreased ability of adhesion to both the polystyrene microplates and buccal epithelial cells and invasion of host epithelial cells. These findings revealed a novel role of C. albicans Cfl1 in maintenance of CWI, mitochondrial function, and interaction between this pathogen and the host. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

Combining Ferric Salt and Cactus Mucilage for Arsenic Removal from Water.

Science.gov (United States)

Fox, Dawn I; Stebbins, Daniela M; Alcantar, Norma A

2016-03-01

New methods to remediate arsenic-contaminated water continue to be studied, particularly to fill the need for accessible methods that can significantly impact developing communities. A combination of cactus mucilage and ferric (Fe(III)) salt was investigated as a flocculation-coagulation system to remove arsenic (As) from water. As(V) solutions, ferric nitrate, and mucilage suspensions were mixed and left to stand for various periods of time. Visual and SEM observations confirmed the flocculation action of the mucilage as visible flocs formed and settled to the bottom of the tubes within 3 min. The colloidal suspensions without mucilage were stable for up to 1 week. Sample aliquots were tested for dissolved and total arsenic by ICP-MS and HGAFS. Mucilage treatment improved As removal (over Fe(III)-only treatment); the system removed 75-96% As in 30 min. At neutral pH, removal was dependent on Fe(III) and mucilage concentration and the age of the Fe(III) solution. The process is fast, achieving maximum removal in 30 min, with the majority of As removed in 10-15 min. Standard jar tests with 1000 μg/L As(III) showed that arsenic removal and settling rates were pH-dependent; As removal was between 52% (high pH) and 66% (low pH).

Characterization of ferric arsenate-sulfate compounds: Implications for arsenic control in refractory gold processing residues

Czech Academy of Sciences Publication Activity Database

Paktunc, D.; Majzlan, J.; Palatinus, Lukáš; Dutrizac, J.; Klementová, Mariana; Poirier, G.

2013-01-01

Roč. 98, č. 4 (2013), s. 554-565 ISSN 0003-004X Institutional support: RVO:68378271 Keywords : arsenic * ferric arsenate sulfate * autoclave residue * hydrometallurgy Subject RIV: DB - Geology ; Mineralogy Impact factor: 2.059, year: 2013

FeII induced mineralogical transformations of ferric oxyhydroxides into magnetite of variable stoichiometry and morphology

International Nuclear Information System (INIS)

Usman, M.; Abdelmoula, M.; Hanna, K.

2012-01-01

The Mössbauer spectroscopy was used to monitor the mineralogical transformations of ferrihydrite (F), lepidocrocite (L) and goethite (G) into magnetite as a function of aging time. Ferric oxyhydroxides were reacted with soluble Fe II and OH – in stoichiometric amounts to form magnetite at an initial pH of ∼9.7. Observed transformation extent into magnetite followed the order: F>L>G with almost 30% of untransformed G after 1 month. The departure from stoichiometry, δ, of magnetite (Fe 3−δ O 4 ) generated from F (δ∼0.04) and L (δ∼0.05) was relatively low as compared to that in magnetite from G (δ∼0.08). The analysis by transmission electron microscopy and BET revealed that generated magnetite was also different in terms of morphology, particle size and surface area depending on the nature of initial ferric oxyhydroxide. This method of preparation is a possible way to form nano-sized magnetite. - Graphical abstract: Mössbauer spectrum of the early stage of magnetite formation formed from the interaction of adsorbed Fe II species with goethite. Highlights: ► Ferric oxides were reacted with hydroxylated Fe II to form magnetite. ► Magnetite formation was quantified as a function of aging time. ► Complete transformation of ferrihydrite and lepidocrocite was achieved. ► Almost 70% of initial goethite was transformed. ► Resulting magnetites have differences in stoichiometry and morphological properties.

Energy cascades, excited state dynamics, and photochemistry in cob(III)alamins and ferric porphyrins.

Science.gov (United States)

Rury, Aaron S; Wiley, Theodore E; Sension, Roseanne J

2015-03-17

Porphyrins and the related chlorins and corrins contain a cyclic tetrapyrrole with the ability to coordinate an active metal center and to perform a variety of functions exploiting the oxidation state, reactivity, and axial ligation of the metal center. These compounds are used in optically activated applications ranging from light harvesting and energy conversion to medical therapeutics and photodynamic therapy to molecular electronics, spintronics, optoelectronic thin films, and optomagnetics. Cobalt containing corrin rings extend the range of applications through photolytic cleavage of a unique axial carbon-cobalt bond, permitting spatiotemporal control of drug delivery. The photochemistry and photophysics of cyclic tetrapyrroles are controlled by electronic relaxation dynamics including internal conversion and intersystem crossing. Typically the electronic excitation cascades through ring centered ππ* states, ligand to metal charge transfer (LMCT) states, metal to ligand charge transfer (MLCT) states, and metal centered states. Ultrafast transient absorption spectroscopy provides a powerful tool for the investigation of the electronic state dynamics in metal containing tetrapyrroles. The UV-visible spectrum is sensitive to the oxidation state, electronic configuration, spin state, and axial ligation of the central metal atom. Ultrashort broadband white light probes spanning the range from 270 to 800 nm, combined with tunable excitation pulses, permit the detailed unravelling of the time scales involved in the electronic energy cascade. State-of-the-art theoretical calculations provide additional insight required for precise assignment of the states. In this Account, we focus on recent ultrafast transient absorption studies of ferric porphyrins and corrin containing cob(III)alamins elucidating the electronic states responsible for ultrafast energy cascades, excited state dynamics, and the resulting photoreactivity or photostability of these compounds. Iron

Diffusion simulation of ferric ions in dosemeter Fricke-gel with variable diffusion coefficient

International Nuclear Information System (INIS)

Milani, Caio Jacob; Bevilacqua, Joyce da Silva; Rodrigues Junior, Orlando

2014-01-01

Dosimetry using dosimeters Fricke-xylenol-Gel (FXG) allows confirmation and better understanding of radiotherapy treatments. The technique involves the evaluation of volumes irradiated by magnetic resonance imaging (MRI) or CT-optical. In both cases, the time spent between the irradiation and measurement is an important factor that directly influences the results. The quality of the images can be compromised by the mobility of ferric ions (Fe 3+), formed during the interaction of radiation with matter, increasing the uncertainty in determining the isodose. In this work, we simulated the dynamic involving ferric ions formed in one irradiated region irradiated in a two-dimensional domain with a variable diffusion coefficient. This phenomenon is modeled by a differential equation and solved numerically by an efficient algorithm that generalizes the Crank-Nicolson method. The stability and consistency of the method guarantee the convergence of the numerical solution for a predefined tolerance based in the choice of discretization steps of time and space. Different continuous functions were chosen to represent the diffusion coefficient and graphical views of the phenomenon are presented for a better understanding of the process

Ferric Iron Reduction by Bacteria Associated with the Roots of Freshwater and Marine Macrophytes†

Science.gov (United States)

King, G. M.; Garey, Meredith A.

1999-01-01

In vitro assays of washed, excised roots revealed maximum potential ferric iron reduction rates of >100 μmol g (dry weight)−1 day−1 for three freshwater macrophytes and rates between 15 and 83 μmol (dry weight)−1 day−1 for two marine species. The rates varied with root morphology but not consistently (fine root activity exceeded smooth root activity in some but not all cases). Sodium molybdate added at final concentrations of 0.2 to 20 mM did not inhibit iron reduction by roots of marine macrophytes (Spartina alterniflora and Zostera marina). Roots of a freshwater macrophyte, Sparganium eurycarpum, that were incubated with an analog of humic acid precursors, anthroquinone disulfate (AQDS), reduced freshly precipitated iron oxyhydroxide contained in dialysis bags that excluded solutes with molecular weights of >1,000; no reduction occurred in the absence of AQDS. Bacterial enrichment cultures and isolates from freshwater and marine roots used a variety of carbon and energy sources (e.g., acetate, ethanol, succinate, toluene, and yeast extract) and ferric oxyhydroxide, ferric citrate, uranate, and AQDS as terminal electron acceptors. The temperature optima for a freshwater isolate and a marine isolate were equivalent (approximately 32°C). However, iron reduction by the freshwater isolate decreased with increasing salinity, while reduction by the marine isolate displayed a relatively broad optimum salinity between 20 and 35 ppt. Our results suggest that by participating in an active iron cycle and perhaps by reducing humic acids, iron reducers in the rhizoplane of aquatic macrophytes limit organic availability to other heterotrophs (including methanogens) in the rhizosphere and bulk sediments. PMID:10508065

The equilibrium leach testing of ferric/aluminium hydroxide flocs

International Nuclear Information System (INIS)

Biddle, P.; Greenfield, B.F.; Greenham, P.S.; Rees, J.H.

1987-09-01

Equilibrium leach tests have been carried out on ferric/aluminium hydroxide flocs using cement and resin matrices, and cement and clay backfills in both air and nitrogen atmospheres. The equilibrium concentrations of a number of actinides and fission products were measured in leachates obtained over periods of up to a year. The lowest equilibrium actinide concentrations were found in leachates from systems with a cement backfill. Cement matrix-cement backfill was the most promising combination for limiting concentrations of long-lived radionuclides, resin-clay the least. Comparison of leachate concentrations with limiting drinking water concentrations are made and the high degree of protection afforded by candidate near field components shown. (author)

The equilibrium leach testing of ferric/aluminium hydroxide flocs

International Nuclear Information System (INIS)

Biddle, P.; Greenfield, B.F.; Greenham, P.S.; Rees, J.H.

1987-09-01

Equilibrium leach tests have been carried out on ferric/aluminium hydroxide flocs using cement and resin matrices, and cement and clay backfills in both air and nitrogen atmospheres. The equilibrium concentrations of a number of actinides and fission products were measured in leachates obtained over periods of up to a year. The lowest equilibrium actinide concentrations were found in leachates from systems with a cement backfill. Cement matrix-cement backfill was the most promising combination for limiting concentrations of long-lived radionuclides, resin-clay the least. Comparisons of leachate concentrations with limiting drinking water concentrations are made and the high degree of protection afforded by candidate near field components shown. (author)

Nanofabrication and coloration study of artificial Morpho butterfly wings with aligned lamellae layers

Science.gov (United States)

Zhang, Sichao; Chen, Yifang

2015-11-01

The bright and iridescent blue color from Morpho butterfly wings has attracted worldwide attentions to explore its mysterious nature for long time. Although the physics of structural color by the nanophotonic structures built on the wing scales has been well established, replications of the wing structure by standard top-down lithography still remains a challenge. This paper reports a technical breakthrough to mimic the blue color of Morpho butterfly wings, by developing a novel nanofabrication process, based on electron beam lithography combined with alternate PMMA/LOR development/dissolution, for photonic structures with aligned lamellae multilayers in colorless polymers. The relationship between the coloration and geometric dimensions as well as shapes is systematically analyzed by solving Maxwell’s Equations with a finite domain time difference simulator. Careful characterization of the mimicked blue by spectral measurements under both normal and oblique angles are carried out. Structural color in blue reflected by the fabricated wing scales, is demonstrated and further extended to green as an application exercise of the new technique. The effects of the regularity in the replicas on coloration are analyzed. In principle, this approach establishes a starting point for mimicking structural colors beyond the blue in Morpho butterfly wings.

Nanofabrication and coloration study of artificial Morpho butterfly wings with aligned lamellae layers.

Science.gov (United States)

Zhang, Sichao; Chen, Yifang

2015-11-18

The bright and iridescent blue color from Morpho butterfly wings has attracted worldwide attentions to explore its mysterious nature for long time. Although the physics of structural color by the nanophotonic structures built on the wing scales has been well established, replications of the wing structure by standard top-down lithography still remains a challenge. This paper reports a technical breakthrough to mimic the blue color of Morpho butterfly wings, by developing a novel nanofabrication process, based on electron beam lithography combined with alternate PMMA/LOR development/dissolution, for photonic structures with aligned lamellae multilayers in colorless polymers. The relationship between the coloration and geometric dimensions as well as shapes is systematically analyzed by solving Maxwell's Equations with a finite domain time difference simulator. Careful characterization of the mimicked blue by spectral measurements under both normal and oblique angles are carried out. Structural color in blue reflected by the fabricated wing scales, is demonstrated and further extended to green as an application exercise of the new technique. The effects of the regularity in the replicas on coloration are analyzed. In principle, this approach establishes a starting point for mimicking structural colors beyond the blue in Morpho butterfly wings.

Ferritin Elevation and Improved Responsiveness to Erythropoiesis-Stimulating Agents in Patients on Ferric Citrate Hydrate

Directory of Open Access Journals (Sweden)

Keitaro Yokoyama

2017-05-01

Discussion: It is suggested that not only iron load but also the erythropoiesis-stimulating agent dose reduction may be involved in ferritin elevation during ferric citrate hydrate treatment, resulting in a decrease of erythropoietin resistance index.

Safety and Efficacy of Ferric Carboxymaltose in Anemic Pregnant Women: A Retrospective Case Control Study

NARCIS (Netherlands)

Pels, Anouk; Ganzevoort, Wessel

2015-01-01

Background. Anemia during pregnancy is commonly caused by iron deficiency and can have severe consequences for both the mother and the developing fetus. The aim of this retrospective study was to assess the safety and efficacy of intravenous ferric carboxymaltose (FCM) in pregnant women. Methods.

Metal photonics and plasmonics for energy generation

Science.gov (United States)

Nagpal, Prashant

Energy generation from renewable sources and conservation of energy are important goals for reducing our carbon footprint on the environment. Important sources of renewable energy like sun and geothermal energy are difficult to harness because of their energetically broad radiation. Most of our current energy requirements are met through consumption of fossil fuels, and more than 60% of this energy is released to the environment as "waste heat". Thus, converting heat from sun, or inefficient furnaces and automobiles can provide an important source of energy generation. In the present work, I describe design, fabrication, and characterization two and three dimensional patterned metals. These nanofabricated structures can be used as selective emitters to tailor the glow of hot objects. The tailored radiation can then be converted efficiently into electricity using an infrared photocell. This thermophotovoltaic conversion can be very efficient, and useful for converting heat-to-electricity from a wide variety of sources.

Arsenic removal from acidic solutions with biogenic ferric precipitates

Energy Technology Data Exchange (ETDEWEB)

Ahoranta, Sarita H., E-mail: sarita.ahoranta@tut.fi [Department of Chemistry and Bioengineering, Tampere University of Technology, P.O. Box 541, FI-33101 Tampere (Finland); Kokko, Marika E., E-mail: marika.kokko@tut.fi [Department of Chemistry and Bioengineering, Tampere University of Technology, P.O. Box 541, FI-33101 Tampere (Finland); Papirio, Stefano, E-mail: stefano.papirio@unicas.it [Department of Chemistry and Bioengineering, Tampere University of Technology, P.O. Box 541, FI-33101 Tampere (Finland); Özkaya, Bestamin, E-mail: bozkaya@yildiz.edu.tr [Department of Chemistry and Bioengineering, Tampere University of Technology, P.O. Box 541, FI-33101 Tampere (Finland); Department of Environmental Engineering, Yildiz Technical University, Davutpasa Campus 34220, Esenler, Istanbul (Turkey); Puhakka, Jaakko A., E-mail: jaakko.puhakka@tut.fi [Department of Chemistry and Bioengineering, Tampere University of Technology, P.O. Box 541, FI-33101 Tampere (Finland)

2016-04-05

Highlights: • Continuous and rapid arsenic removal with biogenic jarosite was achieved at pH 3.0. • Arsenic removal was inefficient below pH 2.4 due to reduced Fe–As co-precipitation. • As(V) had better sorption characteristics than As(III). • Biogenic jarosite adsorbed arsenic more effectively than synthetic jarosite. - Abstract: Treatment of acidic solution containing 5 g/L of Fe(II) and 10 mg/L of As(III) was studied in a system consisting of a biological fluidized-bed reactor (FBR) for iron oxidation, and a gravity settler for iron precipitation and separation of the ferric precipitates. At pH 3.0 and FBR retention time of 5.7 h, 96–98% of the added Fe(II) precipitated (99.1% of which was jarosite). The highest iron oxidation and precipitation rates were 1070 and 28 mg/L/h, respectively, and were achieved at pH 3.0. Subsequently, the effect of pH on arsenic removal through sorption and/or co-precipitation was examined by gradually decreasing solution pH from 3.0 to 1.6 (feed pH). At pH 3.0, 2.4 and 1.6, the highest arsenic removal efficiencies obtained were 99.5%, 80.1% and 7.1%, respectively. As the system had ferric precipitates in excess, decreased arsenic removal was likely due to reduced co-precipitation at pH < 2.4. As(III) was partially oxidized to As(V) in the system. In shake flask experiments, As(V) sorbed onto jarosite better than As(III). Moreover, the sorption capacity of biogenic jarosite was significantly higher than that of synthetic jarosite. The developed bioprocess simultaneously and efficiently removes iron and arsenic from acidic solutions, indicating potential for mining wastewater treatment.

Super-resolution nanofabrication with metal-ion doped hybrid material through an optical dual-beam approach

International Nuclear Information System (INIS)

Cao, Yaoyu; Li, Xiangping; Gu, Min

2014-01-01

We apply an optical dual-beam approach to a metal-ion doped hybrid material to achieve nanofeatures beyond the optical diffraction limit. By spatially inhibiting the photoreduction and the photopolymerization, we realize a nano-line, consisting of polymer matrix and in-situ generated gold nanoparticles, with a lateral size of sub 100 nm, corresponding to a factor of 7 improvement compared to the diffraction limit. With the existence of gold nanoparticles, a plasmon enhanced super-resolution fabrication mechanism in the hybrid material is observed, which benefits in a further reduction in size of the fabricated feature. The demonstrated nanofeature in hybrid materials paves the way for realizing functional nanostructures

Arsenic and antimony removal from drinking water by adsorption on granular ferric oxide.

Science.gov (United States)

Sazakli, Eleni; Zouvelou, Stavroula V; Kalavrouziotis, Ioannis; Leotsinidis, Michalis

2015-01-01

Arsenic and antimony occur in drinking water due to natural weathering or anthropogenic activities. There has been growing concern about their impact on health. The aim of this study was to assess the efficiency of a granular ferric oxide adsorbent medium to remove arsenic and antimony from drinking water via rapid small-scale column tests (RSSCTs). Three different water matrices - deionized, raw water treated with a reverse osmosis domestic device and raw water - were spiked with arsenic and/or antimony to a concentration of 100 μg L⁻¹. Both elements were successfully adsorbed onto the medium. The loadings until the guideline value was exceeded in the effluent were found to be 0.35-1.63 mg g⁻¹ for arsenic and 0.12-2.11 mg g⁻¹ for antimony, depending on the water matrix. Adsorption of one element was not substantially affected by the presence of the other. Aeration did not affect significantly the adsorption capacity. Granular ferric oxide could be employed for the simultaneous removal of arsenic and antimony from drinking water, whereas full-scale systems should be assessed via laboratory tests before their implementation.

Evaluation of hydrous ferric oxide loaded activated carbon as a granular composite sorbent for radiostrontium

International Nuclear Information System (INIS)

Samanta, S.K.

1997-01-01

A composite sorbent was prepared in granular form by depositing hydrous ferric oxide inside the pores of activated carbon. The composite sorbent was found to show excellent sorption of radiostrontium in the presence of high sodium concentration under alkaline conditions. (author). 3 refs., 2 figs., 1 tab

Ferric chloride modified zeolite in wastewater on Cr (VI) adsorption characteristics

Science.gov (United States)

Wu, Xiaoqing; Zhang, Kang; Chen, Wen; Zhang, Hua

2018-03-01

Zeolite was modified by ferric chloride(Fe-Z) removal Cr (VI) ion from wastewater. The results showed that the effect of Cr(VI) adsorption on modified zeolite depended significantly on pH. It is favorable for the adsorption of Cr(VI) in acid condition. The Langmuir isotherm model has high fitting accuracy with experimental data, demonstrated that is monolayer adsorption and chemical adsorption.The pseudo-second-order equation provided the best correlation to the data. The model can describe the adsorption reaction process well.

Extraction of uranium from coarse ore and acid-curing and ferric sulphate-trickle leaching process

International Nuclear Information System (INIS)

Jin Suoqing

1994-01-01

On the basis of analysis of the problems in the technology of the traditional uranium hydrometallurgy and the limitations of thin layer leaching process (TLL), a new leaching system-acid-curing and ferric sulphate-trickle leaching (AFL) process (NGJ in Chinese) has developed for extraction of uranium from the coarse ore. The ferric sulphate solution was used for trickling the acid-cured uranium ore and the residual leaching reaction incomplete in TLL process can be improved in this process. And the AFL process has a wide applicability to China's uranium ores, being in competition with the traditional agitation leaching process for treating coarse ores. The uranium ore processing technology based on the AFL process will become one of the new basic technologies of uranium hydrometallurgy. A series of difficulties will be basically overcome associated with fine grinding because of its elimination in the presented process. Moreover, the situation of the present uranium hydrometallurgy can be also changed owing to without technological effluent discharge

Sodium nitroprusside may modulate Escherichia coli antioxidant enzyme expression by interacting with the ferric uptake regulator.

Science.gov (United States)

Bertrand, R; Danielson, D; Gong, V; Olynik, B; Eze, M O

2012-01-01

Efforts to explore possible relationships between nitric oxide (NO) and antioxidant enzymes in an Escherichia coli model have uncovered a possible interaction between sodium nitroprusside (SNP), a potent, NO-donating drug, and the ferric uptake regulator (Fur), an iron(II)--dependent regulator of antioxidant and iron acquisition proteins present in Gram-negative bacteria. The enzymatic profiles of superoxide dismutase and hydroperoxidase during logarithmic phase of growth were studied via non-denaturing polyacrylamide gel electrophoresis and activity staining specific to each enzyme. Though NO is known to induce transcription of the manganese-bearing isozyme of SOD (MnSOD), treatment with SNP paradoxically suppressed MnSOD expression and greatly enhanced the activity of the iron-containing equivalent (FeSOD). Fur, one of six global regulators of MnSOD transcription, is uniquely capable of suppressing MnSOD while enhancing FeSOD expression through distinct mechanisms. We thus hypothesize that Fur is complacent in causing this behaviour and that the iron(II) component of SNP is activating Fur. E. coli was also treated with the SNP structural analogues, potassium ferricyanide (PFi) and potassium ferrocyanide (PFo). Remarkably, the ferrous PFo was capable of mimicking the SNP-related pattern, whereas the ferric PFi was not. As Fur depends upon ferrous iron for activation, we submit this observation of redox-specificity as preliminary supporting evidence for the hypothesized Fur-SNP interaction. Iron is an essential metal that the human innate immune system sequesters to prevent its use by invading pathogens. As NO is known to inhibit iron-bound Fur, and as activated Fur regulates iron uptake through feedback inhibition, we speculate that the administration of this drug may disrupt this strategic management of iron in favour of residing Gram-negative species by providing a source of iron in an otherwise iron-scarce environment capable of encouraging its own uptake

Nano-fabrication of molecular electronic junctions by targeted modification of metal-molecule bonds

Science.gov (United States)

Jafri, S. Hassan M.; Löfås, Henrik; Blom, Tobias; Wallner, Andreas; Grigoriev, Anton; Ahuja, Rajeev; Ottosson, Henrik; Leifer, Klaus

2015-09-01

Reproducibility, stability and the coupling between electrical and molecular properties are central challenges in the field of molecular electronics. The field not only needs devices that fulfill these criteria but they also need to be up-scalable to application size. In this work, few-molecule based electronics devices with reproducible electrical characteristics are demonstrated. Our previously reported 5 nm gold nanoparticles (AuNP) coated with ω-triphenylmethyl (trityl) protected 1,8-octanedithiol molecules are trapped in between sub-20 nm gap spacing gold nanoelectrodes forming AuNP-molecule network. When the trityl groups are removed, reproducible devices and stable Au-thiol junctions are established on both ends of the alkane segment. The resistance of more than 50 devices is reduced by orders of magnitude as well as a reduction of the spread in the resistance histogram is observed. By density functional theory calculations the orders of magnitude decrease in resistance can be explained and supported by TEM observations thus indicating that the resistance changes and strongly improved resistance spread are related to the establishment of reproducible and stable metal-molecule bonds. The same experimental sequence is carried out using 1,6-hexanedithiol functionalized AuNPs. The average resistances as a function of molecular length, demonstrated herein, are comparable to the one found in single molecule devices.

Analysis of spatial diffusion of ferric ions in PVA-GTA gel dosimeters through magnetic resonance imaging

Energy Technology Data Exchange (ETDEWEB)

Marrale, Maurizio [Dipartimento di Fisica e Chimica, Universitá di Palermo, Viale delle Scienze, Edificio 18, 90128 Palermo (Italy); Istituto Nazionale di Fisica Nucleare (INFN) – Gruppo V Sezione di Catania, Via Santa Sofia, 64, 95123 Catania (Italy); ATeN Center, Università di Palermo, Viale delle Scienze, Edificio 18, 90128 Palermo (Italy); Collura, Giorgio [Dipartimento di Fisica e Chimica, Universitá di Palermo, Viale delle Scienze, Edificio 18, 90128 Palermo (Italy); Istituto Nazionale di Fisica Nucleare (INFN) – Gruppo V Sezione di Catania, Via Santa Sofia, 64, 95123 Catania (Italy); Gallo, Salvatore, E-mail: salvatore.gallo05@unipa.it [Dipartimento di Fisica e Chimica, Universitá di Palermo, Viale delle Scienze, Edificio 18, 90128 Palermo (Italy); Istituto Nazionale di Fisica Nucleare (INFN) – Gruppo V Sezione di Catania, Via Santa Sofia, 64, 95123 Catania (Italy); Dipartimento di Fisica, Universitá di Milano, Via Giovanni Celoria 16, 20133 Milano (Italy); Nici, Stefania [Dipartimento di Fisica e Chimica, Universitá di Palermo, Viale delle Scienze, Edificio 18, 90128 Palermo (Italy); Tranchina, Luigi [ATeN Center, Università di Palermo, Viale delle Scienze, Edificio 18, 90128 Palermo (Italy); Abbate, Boris Federico [U.O.C. Fisica Sanitaria, A.R.N.A.S., Ospedale Civico Palermo, Piazza Nicola Leotta 4, 90127 Palermo (Italy); Marineo, Sandra; Caracappa, Santo [Istituto Zooprofilattico Sperimentale della Sicilia (IZS), Via Gino Marinuzzi, 3, 90129 Palermo (Italy); and others

2017-04-01

Highlights: • Analysis of ferric ions diffusion throughout the gel matrix in PVA-GTA samples. • Measurements with preclinical 7T MRI scanner with spatial resolution of 200 μm. • Diffusion process is much slower for PVA-GTA gels than for agarose ones. - Abstract: This work focused on the analysis of the temporal diffusion of ferric ions through PVA-GTA gel dosimeters. PVA-GTA gel samples, partly exposed with 6 MV X-rays in order to create an initial steep gradient, were mapped using magnetic resonance imaging on a 7T MRI scanner for small animals. Multiple images of the gels were acquired over several hours after irradiation and were analyzed to quantitatively extract the signal profile. The spatial resolution achieved is 200 μm and this makes this technique particularly suitable for the analysis of steep gradients of ferric ion concentration. The results obtained with PVA-GTA gels were compared with those achieved with agarose gels, which is a standard dosimetric gel formulation. The analysis showed that the diffusion process is much slower (more than five times) for PVA-GTA gels than for agarose ones. Furthermore, it is noteworthy that the diffusion coefficient value obtained through MRI analysis is significantly consistent with that obtained in separate study Marini et al. (Submitted for publication) using a totally independent method such as spectrophotometry. This is a valuable result highlighting that the good dosimetric features of this gel matrix not only can be reproduced but also can be measured through independent experimental techniques based on different physical principles.

Effects of lead mineralogy on soil washing enhanced by ferric salts as extracting and oxidizing agents.

Science.gov (United States)

Yoo, Jong-Chan; Park, Sang-Min; Yoon, Geun-Seok; Tsang, Daniel C W; Baek, Kitae

2017-10-01

In this study, we evaluated the feasibility of using ferric salts including FeCl 3 and Fe(NO 3 ) 3 as extracting and oxidizing agents for a soil washing process to remediate Pb-contaminated soils. We treated various Pb minerals including PbO, PbCO 3 , Pb 3 (CO 3 ) 2 (OH) 2 , PbSO 4 , PbS, and Pb 5 (PO 4 ) 3 (OH) using ferric salts, and compared our results with those obtained using common washing agents of HCl, HNO 3 , disodium-ethylenediaminetetra-acetic acid (Na 2 -EDTA), and citric acid. The use of 50 mM Fe(NO 3 ) 3 extracted significantly more Pb (above 96% extraction) from Pb minerals except PbSO 4 (below 55% extraction) compared to the other washing agents. In contrast, washing processes using FeCl 3 and HCl were not effective for extraction from Pb minerals because of PbCl 2 precipitation. Yet, the newly formed PbCl 2 could be dissolved by subsequent wash with distilled water under acidic conditions. When applying our washing method to remediate field-contaminated soil from a shooting range that had high concentrations of Pb 3 (CO 3 ) 2 (OH) 2 and PbCO 3 , we extracted more Pb (approximately 99% extraction) from the soil using 100 mM Fe(NO 3 ) 3 than other washing agents at the same process conditions. Our results show that ferric salts can be alternative washing agents for Pb-contaminated soils in view of their extracting and oxidizing abilities. Copyright © 2017 Elsevier Ltd. All rights reserved.

FecB, a periplasmic ferric-citrate transporter from E. coli, can bind different forms of ferric-citrate as well as a wide variety of metal-free and metal-loaded tricarboxylic acids.

Science.gov (United States)

Banerjee, Sambuddha; Paul, Subrata; Nguyen, Leonard T; Chu, Byron C H; Vogel, Hans J

2016-01-01

The Escherichia coli Fec system, consisting of an outer membrane receptor (FecA), a periplasmic substrate binding protein (FecB) and an inner membrane permease-ATPase type transporter (FecC/D), plays an important role in the uptake and transport of Fe(3+)-citrate. Although several FecB sequences from various organisms have been reported, there are no biophysical or structural data available for this protein to date. In this work, using isothermal titration calorimetry (ITC), we report for the first time the ability of FecB to bind different species of Fe(3+)-citrate as well as other citrate complexes with trivalent (Ga(3+), Al(3+), Sc(3+) and In(3+)) and a representative divalent metal ion (Mg(2+)) with low μM affinity. Interestingly, ITC experiments with various iron-free di- and tricarboxylic acids show that FecB can bind tricarboxylates with μM affinity but not biologically relevant dicarboxylates. The ability of FecB to bind with metal-free citrate is also observed in (1)H,(15)N HSQC-NMR titration experiments reported here at two different pH values. Further, differential scanning calorimetry (DSC) experiments indicate that the ligand-bound form of FecB has greater thermal stability than ligand-free FecB under all pH and ligand conditions tested, which is consistent with the idea of domain closure subsequent to ligand binding for this type of periplasmic binding proteins.

Effect of heavy metals ondecolorization of reactive brilliant red by newly isolated microorganisms

International Nuclear Information System (INIS)

Nosheen, S.; Arshad, M.

2011-01-01

This study involves aerobic decolorisation of reactive azo dye reactive brilliant red 2KBP by newly isolated microbial strains (two bacterial and one fungal strain) in presence of heavy metals including cobalt chloride, ferric chloride, zinc sulphate, copper sulphate and nickel chloride. Many heavy metals are necessary for microbial growth and are required in very small amounts however at higher levels they become toxic. So was the objective of present work to check the effect of concentration of heavy metals on the potential of microbial strains to decolorize azo dyes. All the heavy metals under consideration were added in range of 0.5 gl-1-2.5gl/sup -1/. All heavy metals showed inhibitory effect on decolorization capacity of bacterial as well as fungal strain .At optimum conditions bacterial strains named as B1 and B2 removed 84% and 78% while fungal strain decolorized 90.4% of dye. Cobalt and nickel showed greater inhibitors on% decolorization of dyes than Zinc and iron. Fungal strain showed greater negative effect. Heavy metals might affect enzyme activities and thus reducing removal of dye. (author)

Enhancement of Fenton oxidation for removing organic matter from hypersaline solution by accelerating ferric system with hydroxylamine hydrochloride and benzoquinone.

Science.gov (United States)

Peng, Siwei; Zhang, Weijun; He, Jie; Yang, Xiaofang; Wang, Dongsheng; Zeng, Guisheng

2016-03-01

Fenton oxidation is generally inhibited in the presence of a high concentration of chloride ions. This study investigated the feasibility of using benzoquinone (BQ) and hydroxylamine hydrochloride (HA) as Fenton enhancers for the removal of glycerin from saline water under ambient temperature by accelerating the ferric system. It was found that organics removal was not obviously affected by chloride ions of low concentration (less than 0.1mol/L), while the mineralization rate was strongly inhibited in the presence of a large amount of chloride ions. In addition, ferric hydrolysis-precipitation was significantly alleviated in the presence of HA and BQ, and HA was more effective in reducing ferric ions into ferrous ions than HA, while the H2O2 decomposition rate was higher in the BQ-Fenton system. Electron spin resonance analysis revealed that OH production was reduced in high salinity conditions, while it was enhanced after the addition of HA and BQ (especially HA). This study provided a possible solution to control and alleviate the inhibitory effect of chloride ions on the Fenton process for organics removal. Copyright © 2015. Published by Elsevier B.V.

VOLATILE CHLORIDE PROCESS FOR THE RECOVERY OF METAL VALUES

Science.gov (United States)

Hanley, W.R.

1959-01-01

A process is presented for recovering uranium, iron, and aluminum from centain shale type ores which contain uranium in minute quantities. The ore is heated wiih a chlorinating agent. such as chlorine, to form a volatilized stream of metal chlorides. The chloride stream is then passed through granular alumina which preferentially absorbs the volatile uranium chloride and from which the uranium may later be recovered. The remaining volatilized chlorides, chiefly those of iron and aluminum, are further treated to recover chlorine gas for recycle, and to recover ferric oxide and aluminum oxide as valuable by-products.

Cyanide binding to ferrous and ferric microperoxidase-11.

Science.gov (United States)

Ascenzi, Paolo; Sbardella, Diego; Santucci, Roberto; Coletta, Massimo

2016-07-01

Microperoxidase-11 (MP11) is an undecapeptide derived from horse heart cytochrome c (cytc). MP11 is characterized by a covalently linked solvent-exposed heme group, the heme-Fe atom being axially coordinated by a histidyl residue. Here, the reactions of ferrous and ferric MP11 (MP11-Fe(II) and MP11-Fe(III), respectively) with cyanide have been investigated from the kinetic and thermodynamic viewpoints, at pH 7.0 and 20.0 °C. Values of the second-order rate constant for cyanide binding to MP11-Fe(II) and MP11-Fe(III) are 4.5 M(-1) s(-1) and 8.9 × 10(3) M(-1) s(-1), respectively. Values of the first-order rate constant for cyanide dissociation from ligated MP11-Fe(II) and MP11-Fe(III) are 1.8 × 10(-1) s(-1) and 1.5 × 10(-3) s(-1), respectively. Values of the dissociation equilibrium constant for cyanide binding to MP11-Fe(II) and MP11-Fe(III) are 3.7 × 10(-2) and 1.7 × 10(-7) M, respectively, matching very well with those calculated from kinetic parameters so that no intermediate species seem to be involved in the ligand-binding process. The pH-dependence of cyanide binding to MP11-Fe(III) indicates that CN(-) is the only binding species. Present results have been analyzed in parallel with those of several heme-proteins, suggesting that (1) the ligand accessibility to the metal center and cyanide ionization may modulate the formation of heme-Fe-cyanide complexes, and (2) the general polarity of the heme pocket and/or hydrogen bonding of the heme-bound ligand may affect cyanide exit from the protein matrix. Microperoxidase-11 (MP11) is an undecapeptide derived from horse heart cytochrome c. Penta-coordinated MP11 displays a very high reactivity towards cyanide, whereas the reactivity of hexa-coordinated horse heart cytochrome c is very low.

Optical and electrical properties of thin films of bismuth ferric oxide

International Nuclear Information System (INIS)

Cardona R, D.

2014-01-01

The bismuth ferric oxide (BFO) has caused great attention in recent years because of their multi ferric properties, making it very attractive for different technological applications. In this paper simultaneous ablation of two white (Bi and Fe 2 O 3 ) was used in a reactive atmosphere (containing oxygen) to deposit thin films of BFO. The composition of the films is changed by controlling the plasma parameters such as the average kinetic energy of the ions (E p) and the plasma density (Np). The effects caused by excess of Bi and Fe in atomic structure and the optical and electrical properties of the films BiFeO 3 in terms of plasma parameters were studied. The X-ray diffraction patterns of BFO samples with excess of bismuth above 2% at. They exhibited small changes in structure leading to improved levels of leakage currents compared to levels of the film with a stoichiometry close to BiFeO 3 composition. These samples showed a secondary phase (Bi 2 5FeO 4 0 selenite type) that led to the increase in the values of band gap and resistivity as well as the improvement of the piezoelectric properties. On the other hand, the films with iron excess showed as secondary phase compounds of iron oxide (α - γ-Fe 2 O 3 ) that caused increments in the conductivity and decrease in the values of band gap. The results are discussed in terms of the excesses of Bi and Fe which were correlated with the plasma parameters. (Author)

Synovectomy of the rheumatoid knee using intra-articular injection of dysprosium-165-ferric hydroxide macroaggregates

International Nuclear Information System (INIS)

Sledge, C.B.; Zuckerman, J.D.; Shortkroff, S.; Zalutsky, M.R.; Venkatesan, P.; Snyder, M.A.; Barrett, W.P.

1987-01-01

One hundred and eleven patients who had seropositive rheumatoid arthritis and persistent synovitis of the knee were treated with intra-articular injection of 270 millicuries of dysprosium-165 bound to ferric hydroxide macroaggregates. A two-year follow-up was available for fifty-nine of the treated knees. Thirty-nine had a good result; nine, a fair result; and eleven, a poor result. Of the twenty-five knees that had Stage-I radiographic changes, nineteen had a good result. Of the thirty-four knees that had Stage-II radiographic changes, twenty showed a good result. Systemic spread of the radioactivity from the injected joint was minimum. The mean whole-body dose was calculated to be 0.3 rad and that to the liver twenty-four hours after injection, 3.2 rads. The results indicated that dysprosium-165-ferric hydroxide macroaggregate is an effective agent for performing radiation synovectomy, particularly in knees that have Stage-I radiographic changes. Because of the minimum rate of systemic spread of the dysprosium-165, it offers a definite advantage over agents that previously have been used

Isolation of Trichoderma harzianum (Rifai) growing on ferric hydroxide mud impregnated with gas oil

Energy Technology Data Exchange (ETDEWEB)

Gudin, C. (Lavera Refinery, France); Chater, K.W.A.

1977-09-01

In northern France, gas oil-impregnated ferric hydroxide mud was found to support fungal growth. The fungus was identified by the Commonwealth Mycological Institute, Kew, with whom a reference culture has been registered. Experiments indicated that its growth resulted from the biodegradation of the gas oil. It is believed that, in this unusual situation, contaminating hydrocarbons may be removed from the environment by microbial activity.

Complex sulphide-barite ore leaching in ferric chloride solution

Directory of Open Access Journals (Sweden)

Miroslav Sokić

2016-06-01

Full Text Available The results of research on the leaching process of complex sulphide-barite ore were presented in this paper. The leaching process was carried out in a laboratory autoclave by ferric chloride solution. Considering that those minerals are represented in complex structural-textural relationships, it is not possible to extract lead, zinc and copper minerals from ore by flotation methods. The obtained results confirmed possibility of the ore processing directly, by chemical methods. The effect of temperature, time and oxygen partial pressure on the lead, zinc and copper dissolution was studied. The maximal leaching degree was achieved at 100 °C and amount of 91.5 % for Pb, 96.1 % for Zn and 60.7 % for Cu. Leaching at temperatures above 100 °C is impractical.

Memory Device and Nanofabrication Techniques Using Electrically Configurable Materials

Science.gov (United States)

Ascenso Simões, Bruno

Development of novel nanofabrication techniques and single-walled carbon nanotubes field configurable transistor (SWCNT-FCT) memory devices using electrically configurable materials is presented. A novel lithographic technique, electric lithography (EL), that uses electric field for pattern generation has been demonstrated. It can be used for patterning of biomolecules on a polymer surface and patterning of resist as well. Using electrical resist composed of a polymer having Boc protected amine group and iodonium salt, Boc group on the surface of polymer was modified to free amine by applying an electric field. On the modified surface of the polymer, Streptavidin pattern was fabricated with a sub-micron scale. Also patterning of polymer resin composed of epoxy monomers and diaryl iodonium salt by EL has been demonstrated. Reaction mechanism for electric resist configuration is believed to be induced by an acid generation via electrochemical reduction in the resist. We show a novel field configurable transistor (FCT) based on single-walled carbon nanotube network field-effect transistors in which poly (ethylene glycol) crosslinked by electron-beam is incorporated into the gate. The device conductance can be configured to arbitrary states reversibly and repeatedly by applying external gate voltages. Raman spectroscopy revealed that evolution of the ratio of D- to G-band intensity in the SWCNTs of the FCT progressively increases as the device is configured to lower conductance states. Electron transport studies at low temperatures showed a strong temperature dependence of the resistance. Band gap widening of CNTs up to ˜ 4 eV has been observed by examining the differential conductance-gate voltage-bias voltage relationship. The switching mechanism of the FCT is attributed a structural transformation of CNTs via reversible hydrogenation and dehydrogenations induced by gate voltages, which tunes the CNT bandgap continuously and reversibly to non-volatile analog values

Two-photon polymerization of metal ions doped acrylate monomers and oligomers for three-dimensional structure fabrication

International Nuclear Information System (INIS)

Duan Xuanming; Sun Hongbo; Kaneko, Koshiro; Kawata, Satoshi

2004-01-01

We have investigated two-photon polymerization of metal ions doped acrylate monomers and oligomers which is applied for three-dimensional (3D) micro/nano-structure fabrication. Titanium (IV) ions doped urethane acrylate photopolymerizable resins were synthesized, and their optical and polymerization properties were investigated. The resolution of two-photon polymerization for micro/nanofabrication was evaluated. Titanium dioxide (TiO 2 ) nanoparticles were generated in the polymer matrix of micron-sized polymer structures. A 3D diamond photonic crystal structure, which consisted of polymer composite materials of TiO 2 nanoparticles, was successfully fabricated by direct laser writing and its photonic bandgap was confirmed. This work would give us a new solution for producing 3D micro/nanodevices of functional polymer composite materials

Vapor-Phase Deposition and Modification of Metal-Organic Frameworks: State-of-the-Art and Future Directions.

Science.gov (United States)

Stassen, Ivo; De Vos, Dirk; Ameloot, Rob

2016-10-04

Materials processing, and thin-film deposition in particular, is decisive in the implementation of functional materials in industry and real-world applications. Vapor processing of materials plays a central role in manufacturing, especially in electronics. Metal-organic frameworks (MOFs) are a class of nanoporous crystalline materials on the brink of breakthrough in many application areas. Vapor deposition of MOF thin films will facilitate their implementation in micro- and nanofabrication research and industries. In addition, vapor-solid modification can be used for postsynthetic tailoring of MOF properties. In this context, we review the recent progress in vapor processing of MOFs, summarize the underpinning chemistry and principles, and highlight promising directions for future research. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Fate and Distribution of Heavy Metals in Wastewater Irrigated Calcareous Soils

Science.gov (United States)

Stietiya, Mohammed Hashem; Duqqah, Mohammad; Udeigwe, Theophilus; Zubi, Ruba; Ammari, Tarek

2014-01-01

Accumulation of heavy metals in Jordanian soils irrigated with treated wastewater threatens agricultural sustainability. This study was carried out to investigate the environmental fate of Zn, Ni, and Cd in calcareous soils irrigated with treated wastewater and to elucidate the impact of hydrous ferric oxide (HFO) amendment on metal redistribution among soil fractions. Results showed that sorption capacity for Zarqa River (ZR1) soil was higher than Wadi Dhuleil (WD1) soil for all metals. The order of sorption affinity for WD1 was in the decreasing order of Ni > Zn > Cd, consistent with electrostatic attraction and indication of weak association with soil constituents. Following metal addition, Zn and Ni were distributed among the carbonate and Fe/Mn oxide fractions, while Cd was distributed among the exchangeable and carbonate fractions in both soils. Amending soils with 3% HFO did not increase the concentration of metals associated with the Fe/Mn oxide fraction or impact metal redistribution. The study suggests that carbonates control the mobility and bioavailability of Zn, Ni, and Cd in these calcareous soils, even in presence of a strong adsorbent such as HFO. Thus, it can be inferred that in situ heavy metal remediation of these highly calcareous soils using iron oxide compounds could be ineffective. PMID:24723833

Fate and Distribution of Heavy Metals in Wastewater Irrigated Calcareous Soils

Directory of Open Access Journals (Sweden)

Mohammed Hashem Stietiya

2014-01-01

Full Text Available Accumulation of heavy metals in Jordanian soils irrigated with treated wastewater threatens agricultural sustainability. This study was carried out to investigate the environmental fate of Zn, Ni, and Cd in calcareous soils irrigated with treated wastewater and to elucidate the impact of hydrous ferric oxide (HFO amendment on metal redistribution among soil fractions. Results showed that sorption capacity for Zarqa River (ZR1 soil was higher than Wadi Dhuleil (WD1 soil for all metals. The order of sorption affinity for WD1 was in the decreasing order of Ni > Zn > Cd, consistent with electrostatic attraction and indication of weak association with soil constituents. Following metal addition, Zn and Ni were distributed among the carbonate and Fe/Mn oxide fractions, while Cd was distributed among the exchangeable and carbonate fractions in both soils. Amending soils with 3% HFO did not increase the concentration of metals associated with the Fe/Mn oxide fraction or impact metal redistribution. The study suggests that carbonates control the mobility and bioavailability of Zn, Ni, and Cd in these calcareous soils, even in presence of a strong adsorbent such as HFO. Thus, it can be inferred that in situ heavy metal remediation of these highly calcareous soils using iron oxide compounds could be ineffective.

Ferric chloride-graphite intercalation compounds as anode materials for Li-ion batteries.

Science.gov (United States)

Wang, Lili; Zhu, Yongchun; Guo, Cong; Zhu, Xiaobo; Liang, Jianwen; Qian, Yitai

2014-01-01

Ferric chloride-graphite intercalation compounds (FeCl3 -GICs) with stage 1 and stage 2 structures were synthesized by reacting FeCl3 and expanded graphite (EG) in air in a stainless-steel autoclave. As rechargeable Li-ion batteries, these FeCl3 -GICs exhibit high capacity, excellent cycling stability, and superior rate capability, which could be attributed to their unique intercalation features. This work may enable new possibilities for the fabrication of Li-ion batteries. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Redox Evolution in Magma Oceans Due to Ferric/Ferrous Iron Partitioning

Science.gov (United States)

Schaefer, L.; Elkins-Tanton, L. T.; Pahlevan, K.

2017-12-01

A long-standing puzzle in the evolution of the Earth is that while the present day upper mantle has an oxygen fugacity close to the QFM buffer, core formation during accretion would have occurred at much lower oxygen fugacities close to IW. We present a new model based on experimental evidence that normal solidification and differentiation processes in the terrestrial magma ocean may explain both core formation and the current oxygen fugacity of the mantle without resorting to a change in source material or process. A commonly made assumption is that ferric iron (Fe3+) is negligible at such low oxygen fugacities [1]. However, recent work on Fe3+/Fe2+ ratios in molten silicates [2-4] suggests that the Fe3+ content should increase at high pressure for a given oxygen fugacity. While disproportionation was not observed in these experiments, it may nonetheless be occurring in the melt at high pressure [5]. Therefore, there may be non-negligible amounts of Fe3+ formed through metal-silicate equilibration at high pressures within the magma ocean. Homogenization of the mantle and further partitioning of Fe2+/Fe3+ as the magma ocean crystallizes may explain the oxygen fugacity of the Earth's mantle without requiring additional oxidation mechanisms. We present here models using different parameterizations for the Fe2+/Fe3+ thermodynamic relationships in silicate melts to constrain the evolution of the redox state of the magma ocean as it crystallizes. The model begins with metal-silicate partitioning at high pressure to form the core and set the initial Fe3+ abundance. Combined with previous work on oxygen absorption by magma oceans due to escape of H from H2O [6], we show that the upper layers of solidifying magma oceans should be more oxidized than the lower mantle. This model also suggests that large terrestrial planets should have more oxidized mantles than small planets. From a redox perspective, no change in the composition of the Earth's accreting material needs to be

Pyrite formation and mineral transformation pathways upon sulfidation of ferric hydroxides depend on mineral type and sulfide concentration

NARCIS (Netherlands)

Peiffer, Stefan; Behrends, Thilo; Hellige, Katrin; Larese-Casanova, Philip; Wan, Moli; Pollok, Kilian

2015-01-01

The reaction of ferric (hydr)oxides with dissolved sulfide does not lead to the instantaneous production of thermodynamically stable products but can induce a variety of mineral transformations including the formation of metastable intermediates. The importance of the various transformation pathways

Simultaneous deposition of Ni nanoparticles and wires on a tubular halloysite template: A novel metallized ceramic microstructure

International Nuclear Information System (INIS)

Fu Yubin; Zhang Lide

2005-01-01

Tubular halloysite can be used as a template to fabricate a novel metallized ceramic microstructure through electroless plating. Reduction of Pd ions by methanol is conducted to initiate Ni plating. There is a simultaneous deposition of Ni nanoparticles on the outer surface and discontinuous wires in the lumen site of the halloysite template obtained. The different deposition could be caused by the different composition distribution of ferric oxide impurity in the wall due to the isomorphic substitution during the formation of halloysite template. Its magnetic property is mainly attributed to the Ni nanoparticles, not the wires. The metallized ceramic microstructure has the potential to be utilized as a novel magnetic material

Ferrous and ferric ions-based high-throughput screening strategy for nitrile hydratase and amidase.

Science.gov (United States)

Lin, Zhi-Jian; Zheng, Ren-Chao; Lei, Li-Hua; Zheng, Yu-Guo; Shen, Yin-Chu

2011-06-01

Rapid and direct screening of nitrile-converting enzymes is of great importance in the development of industrial biocatalytic process for pharmaceuticals and fine chemicals. In this paper, a combination of ferrous and ferric ions was used to establish a novel colorimetric screening method for nitrile hydratase and amidase with α-amino nitriles and α-amino amides as substrates, respectively. Ferrous and ferric ions reacted sequentially with the cyanide dissociated spontaneously from α-amino nitrile solution, forming a characteristic deep blue precipitate. They were also sensitive to weak basicity due to the presence of amino amide, resulting in a yellow precipitate. When amino amide was further hydrolyzed to amino acid, it gave a light yellow solution. Mechanisms of color changes were further proposed. Using this method, two isolates with nitrile hydratase activity towards 2-amino-2,3-dimethyl butyronitrile, one strain capable of hydrating 2-amino-4-(hydroxymethyl phosphiny) butyronitrile and another microbe exhibiting amidase activity against 2-amino-4-methylsulfanyl butyrlamide were obtained from soil samples and culture collections of our laboratory. Versatility of this method enabled it the first direct and inexpensive high-throughput screening system for both nitrile hydratase and amidase. Copyright © 2011 Elsevier B.V. All rights reserved.

Ferric ammonium citrate as a positive bowel contrast agent for MR imaging of the upper abdomen

Energy Technology Data Exchange (ETDEWEB)

Kivelitz, D.; Taupitz, M.; Hamm, B. [Universitaetsklinikum Charite, Berlin (Germany). Inst. fuer Radiologie; Gehl, H.B. [Medizinische Univ. Luebeck (Germany). Inst. fuer Radiologie; Heuck, A. [Muenchen Univ. (Germany). Radiologische Klinik; Krahe, T. [Koeln Univ. (Germany). Inst. fuer Radiologische Diagnostik; Lodemann, K.P. [Bracco-Byk Gulden GmbH, Konstanz (Germany)

1999-07-01

Purpose: To evaluate the safety and diagnostic efficacy of two different doses of ferric ammonium citrate as a paramagnetic oral contrast agent for MR imaging of the upper abdomen. Material and methods: Ninety-nine adult patients referred for MR imaging for a known or suspected upper abdominal pathology were included in this randomized multicenter double-blind clinical trial. Imaging was performed with spin-echo (T1- and T2-weighted) and gradient-echo (T1-weighted) techniques before and after administration of either 1200 mg or 2400 mg of ferric ammonium citrate dissolved in 600 ml of water. Safety analysis included monitoring of vital signs, assessment of adverse events, and laboratory testing. Efficacy with regard to organ distension, contrast distribution, bowel enhancement and delineation of adjacent structures was graded qualitatively. Results: No serious adverse events were reported for either of the two concentrations. A total of 31 minor side effects were noted, of which significantly more occurred in the higher dose group (p<0.01). The diagnostic confidence in defining or excluding disease was graded as better after contrast administration for 48% of all images. Marked or moderate enhancement of the upper gastrointestinal tract was achieved at both doses in 69.5% of cases with no evident difference between the two doses. The higher dose tended to show better results in terms of the contrast assessment parameters. Conclusion: Ferric ammonium citrate is a safe and effective oral contrast agent for MR imaging of the upper abdomen at two different dose levels. The higher dose showed a tendency toward better imaging results while the lower dose caused significantly fewer side effects. Therefore, the 1200 mg dose can be recommended in view of the risk-to-benefit ratio. (orig.)

[Topography structure and flocculation mechanism of polymeric phosphate ferric sulfate (PPFS)].

Science.gov (United States)

Zheng, Huai-li; Zhang, Hui-qin; Jiang, Shao-jie; Li, Fang; Jiao, Shi-jun; Fang, Hui-li

2011-05-01

Characteristics of polymeric phosphate ferric sulfate (PPFS) were investigated using FTIR (Fourier transform infrared spectrometer), XRD (X-ray diffraction) and SEM (scanning electron microscope) in the present study. The formed PPFS structure and morphology were stereo meshwork, which was clustered and close to coral reef, synthesis of high charge density, bioactive polyhydroxy and mixed polynuclear complex PPFS. The results showed that charge neutralization of PPFS had not played a decisive role in the coagulation beaker test and the zeta potential proved that PPFS was largely affected by bridging and netting sweep. Therefore, the coagulation mechanisms of PPFS were mainly composed of charge neutralization, adsorption bridging and netting sweep mechanisms.

Influence of Heavy Metal Stress on Antioxidant Status and DNA Damage in Urtica dioica

Directory of Open Access Journals (Sweden)

Darinka Gjorgieva

2013-01-01

Full Text Available Heavy metals have the potential to interact and induce several stress responses in the plants; thus, effects of heavy metal stress on DNA damages and total antioxidants level in Urtica dioica leaves and stems were investigated. The samples are sampled from areas with different metal exposition. Metal content was analyzed by Inductively Coupled Plasma-Atomic Emission Spectrometer (ICP-AES, for total antioxidants level assessment the Ferric-Reducing Antioxidant Power (FRAP assay was used, and genomic DNA isolation from frozen plant samples was performed to obtain DNA fingerprints of investigated plant. It was found that heavy metal contents in stems generally changed synchronously with those in leaves of the plant, and extraneous metals led to imbalance of mineral nutrient elements. DNA damages were investigated by Random Amplified Polymorphic DNA (RAPD technique, and the results demonstrated that the samples exposed to metals yielded a large number of new fragments (total 12 in comparison with the control sample. This study showed that DNA stability is highly affected by metal pollution which was identified by RAPD markers. Results suggested that heavy metal stress influences antioxidant status and also induces DNA damages in U. dioica which may help to understand the mechanisms of metals genotoxicity.

Influence of heavy metal stress on antioxidant status and DNA damage in Urtica dioica.

Science.gov (United States)

Gjorgieva, Darinka; Kadifkova Panovska, Tatjana; Ruskovska, Tatjana; Bačeva, Katerina; Stafilov, Trajče

2013-01-01

Heavy metals have the potential to interact and induce several stress responses in the plants; thus, effects of heavy metal stress on DNA damages and total antioxidants level in Urtica dioica leaves and stems were investigated. The samples are sampled from areas with different metal exposition. Metal content was analyzed by Inductively Coupled Plasma-Atomic Emission Spectrometer (ICP-AES), for total antioxidants level assessment the Ferric-Reducing Antioxidant Power (FRAP) assay was used, and genomic DNA isolation from frozen plant samples was performed to obtain DNA fingerprints of investigated plant. It was found that heavy metal contents in stems generally changed synchronously with those in leaves of the plant, and extraneous metals led to imbalance of mineral nutrient elements. DNA damages were investigated by Random Amplified Polymorphic DNA (RAPD) technique, and the results demonstrated that the samples exposed to metals yielded a large number of new fragments (total 12) in comparison with the control sample. This study showed that DNA stability is highly affected by metal pollution which was identified by RAPD markers. Results suggested that heavy metal stress influences antioxidant status and also induces DNA damages in U. dioica which may help to understand the mechanisms of metals genotoxicity.

Diluting ferric carboxymaltose in sodium chloride infusion solution (0.9% w/v) in polypropylene bottles and bags: effects on chemical stability.

Science.gov (United States)

Philipp, Erik; Braitsch, Michaela; Bichsel, Tobias; Mühlebach, Stefan

2016-01-01

This study was designed to assess the physicochemical stability of colloidal ferric carboxymaltose solution (Ferinject) when diluted and stored in polypropylene (PP) bottles and bags for infusion. Two batches of ferric carboxymaltose solution (Ferinject) were diluted (500 mg, 200 mg and 100 mg iron in 100 mL saline) in PP bottles or bags under aseptic conditions. The diluted solutions were stored at 30°C and 75%±5% relative humidity (rH) for 72 h, and samples were withdrawn aseptically at preparation and after 24 h, 48 h and 72 h. Multiple parameters were used to test stability-related measures (pH, total iron and iron (II) content, molecular weight range determination, microbial contamination and particles count ≥10 μm). Overall, Ferinject diluted in 0.9% (w/v) NaCl solution and stored in PP bottles and bags was stable within the specifications for the complex and the acceptability limits set for all assays. In both containers, total iron content remained stable, within 10% of the theoretical iron content, and levels of iron (II) remained far below the threshold of acceptability. All preparations were free from sediments, particle numbers were acceptable and there was no microbial contamination. The molecular weight distribution and polydispersity index were also acceptable. Under the tested experimental conditions, colloidal ferric carboxymaltose solution (Ferinject) diluted in saline in PP infusion bottles or bags demonstrated physical and chemical stability for up to 72 h at 30°C and 75% rH. Because of the lack of additional clinical data, when using ferric carboxymaltose, physicians/pharmacists should refer to the dilution and storing recommendations given in the product's summary of product characteristics.

[INVITED] Nanofabrication of phase-shifted Bragg gratings on the end facet of multimode fiber towards development of optical filters and sensors

Science.gov (United States)

Gallego, E. E.; Ascorbe, J.; Del Villar, I.; Corres, J. M.; Matias, I. R.

2018-05-01

This work describes the process of nanofabrication of phase-shifted Bragg gratings on the end facet of a multimode optical fiber with a pulsed DC sputtering system based on a single target. Several structures have been explored as a function of parameters such as the number of layers or the phase-shift. The experimental results, corroborated with simulations based on plane-wave propagation in a stack of homogeneous layers, indicate that the phase-shift can be controlled with a high degree of accuracy. The device could be used both in communications, as a filter, or in the sensors domain. As an example of application, a humidity sensor with wavelength shifts of 12 nm in the range of 30 to 90% relative humidity (200 pm/% relative humidity) is presented.

Radioisotopic synovectomy using ferric hydroxide macroaggregated for chronic arthritis treatment

International Nuclear Information System (INIS)

Lima, Carla Flavia; Campos, Tarcisio P.R.

2002-01-01

Synovectomy radioisotopic is an arthritis treatment used in specific clinical conditions whose main goal is to sterilized the synovia. This treatment has specific and precise indications and it is considered to have an adequate response. The present work presents a modeling of an articulation (joint) based on its real geometric anatomy and chemical constitution. The internal dosimetry is evaluated by the Monte Carlo Code. The majority of the radionuclides were considered in the simulations. The syntheses of the ferric hydroxide macroaggregates with dysprosium and samarium have been prepared (Dy 165 -MHF and Sm 153 -MHF). Obtaining the cintilographic images of rabbits in which Dy 165 -MHF is injected is in progress. Biodistribution studies in addition with the internal dosimetry will certify the dose in the membrane of the synovia. (author)

Simulation of ferric ions transfer in dosemeter Fricke-Xylenol-Gel in means no homogeneous

International Nuclear Information System (INIS)

Milani, Caio J.; Bevilacqua, Joyce da Silva; Cavinato, Christianne C.; Rodrigues Junior, Orlando; Campos, Leticia L.

2013-01-01

Dosimetry in three dimensions using Fricke-Xilenol-Gel dosimeters (FXG) allows the confirmation and a better understanding of a treatment by Radiotherapy. The technique involves the assessment of the irradiated volumes by magnetic resonance imaging (MRI) or optical-CT. On both cases, the time elapsed between the irradiation and the measurement is an important factor in the quality of results. The quality of the images can be compromised by the mobility of the ferric ions (Fe 3+ ), formed during the the interaction of the radiation with the matter, increasing the uncertainty in the determination of the isodoses in the volume. In this work, the phenomenon of the diffusion of the ferric ions formed by an irradiated region is simulated in a bidimensional domain. The dynamic of the Fe 3+ in Fricke-Gel is modeled by a parabolic partial differential equation and solved by the ADI-Peaceman-Rachford algorithm. Stability and consistency of the method guarantee the convergence of the numerical solution for a pre-defined error magnitude, based on choices for the discretization values of time and space. Homogeneous and non-homogeneous cases are presented considering an irradiated region and a physical barrier that prevents the movement of the ions, on the non-homogeneous case. Graphical visualizations of the phenomenon are presented for better understanding of the process. (author)

Gallic Acid, Ellagic Acid and Pyrogallol Reaction with Metallic Iron

Energy Technology Data Exchange (ETDEWEB)

Jaen, J. A., E-mail: jjaen@ancon.up.ac.p [Universidad de Panama, Departamento de Quimica Fisica, Facultad de Ciencias Naturales, Exactas y Tecnologia (Panama); Gonzalez, L.; Vargas, A.; Olave, G. [Universidad de Panama, Escuela de Quimica, Facultad de Ciencias Naturales, Exactas y Tecnologia (Panama)

2003-06-15

The reaction between gallic acid, ellagic acid and pyrogallol with metallic iron was studied using infrared and Moessbauer spectroscopy. Most hydrolysable tannins with interesting anticorrosive or inhibition properties are structurally related to these compounds, thus they may be used as models for the study of hydrolysable tannins and related polyphenols. The interaction was followed up to 3 months. Results indicated two different behaviors. At polyphenol concentrations higher than 1% iron converts to sparingly soluble and amorphous ferric (and ferrous) polyphenolate complexes. At lower concentrations (0.1%), the hydrolysis reactions are dominant, resulting in the formation of oxyhydroxides, which can be further reduced to compounds like magnetite by the polyphenols.

Gallic Acid, Ellagic Acid and Pyrogallol Reaction with Metallic Iron

International Nuclear Information System (INIS)

Jaen, J. A.; Gonzalez, L.; Vargas, A.; Olave, G.

2003-01-01

The reaction between gallic acid, ellagic acid and pyrogallol with metallic iron was studied using infrared and Moessbauer spectroscopy. Most hydrolysable tannins with interesting anticorrosive or inhibition properties are structurally related to these compounds, thus they may be used as models for the study of hydrolysable tannins and related polyphenols. The interaction was followed up to 3 months. Results indicated two different behaviors. At polyphenol concentrations higher than 1% iron converts to sparingly soluble and amorphous ferric (and ferrous) polyphenolate complexes. At lower concentrations (0.1%), the hydrolysis reactions are dominant, resulting in the formation of oxyhydroxides, which can be further reduced to compounds like magnetite by the polyphenols.

Iron-reducing bacteria accumulate ferric oxyhydroxide nanoparticle aggregates that may support planktonic growth.

Science.gov (United States)

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.

Removal of Sb(III and Sb(V by Ferric Chloride Coagulation: Implications of Fe Solubility

Directory of Open Access Journals (Sweden)

Muhammad Ali Inam

2018-04-01

Full Text Available Coagulation and precipitation appear to be the most efficient and economical methods for the removal of antimony from aqueous solution. In this study, antimony removal from synthetic water and Fe solubility with ferric chloride (FC coagulation has been investigated. The effects of pH, FC dosage, initial antimony loading and mixed Sb(III, Sb(V proportions on Fe solubility and antimony removal were studied. The results showed that the Sb(III removal efficiency increased with the increase of solution pH particularly due to an increase in Fe precipitation. The Sb(V removal was influenced by the solution pH due to a change in Fe solubility. However, the Fe solubility was only impaired by the Sb(III species at optimum pH 7. The removal efficiencies of both Sb species were enhanced with an increase in FC dose. The quantitative analysis of the isotherm study revealed the strong adsorption potential of Sb(III on Fe precipitates as compared to Sb(V. Furthermore, the removal behavior of antimony was inhibited in mixed proportion with high Sb(V fraction. In conclusion, this study contributes to better understanding the fate of Sb species, their mobilities, and comparative removal behavior, with implications for Fe solubility using ferric chloride in different aqueous environments.

Fabrication of smooth patterned structures of refractory metals, semiconductors, and oxides via template stripping.

Science.gov (United States)

Park, Jong Hyuk; Nagpal, Prashant; McPeak, Kevin M; Lindquist, Nathan C; Oh, Sang-Hyun; Norris, David J

2013-10-09

The template-stripping method can yield smooth patterned films without surface contamination. However, the process is typically limited to coinage metals such as silver and gold because other materials cannot be readily stripped from silicon templates due to strong adhesion. Herein, we report a more general template-stripping method that is applicable to a larger variety of materials, including refractory metals, semiconductors, and oxides. To address the adhesion issue, we introduce a thin gold layer between the template and the deposited materials. After peeling off the combined film from the template, the gold layer can be selectively removed via wet etching to reveal a smooth patterned structure of the desired material. Further, we demonstrate template-stripped multilayer structures that have potential applications for photovoltaics and solar absorbers. An entire patterned device, which can include a transparent conductor, semiconductor absorber, and back contact, can be fabricated. Since our approach can also produce many copies of the patterned structure with high fidelity by reusing the template, a low-cost and high-throughput process in micro- and nanofabrication is provided that is useful for electronics, plasmonics, and nanophotonics.

FPGA-based quench detection system for super-FRS super-ferric dipole prototype

International Nuclear Information System (INIS)

Yang Tongjun; Wu Wei; Yao Qinggao; Yuan Ping; He Yuan; Han Shaofei; Ma Lizhen

2011-01-01

The quench detection system for Super-FRS super-ferric dipole prototype magnet of FAIR has been designed and built. The balance bridge was used to detect quench signal. In order to avoid blind zone of quench detection, two independent bridges were used. NI PXI-7830R FPGA was used to implement filter to quench signal and algorithm of quench decision and to produce quench trigger signal. Pre-sample technique was used in quench data acquisition. The data before and after quench could be recorded for analysis later. The test result indicated that the quench of the dipole's superconducting coil could be reliably detected by the quench detection module. (authors)

Improvement of Sodium Leaching Ratio of Ferric Bauxite Sinter after Direct Reduction

Directory of Open Access Journals (Sweden)

Wentao Hu

2017-01-01

Full Text Available The sodium leaching ratio (ηN of ferric bauxite direct reduction process is much lower than that of ordinary bauxite; thus, the former consumes more sodium than the latter. ηN can be promoted by increasing the dosage of sodium or restricted by increasing the heating temperature and time. However, the restriction effect of heating temperature is 16.67 times larger than that of heating time, and the restriction effect decreases 47.03 times faster when heating temperature increases than that process of heating time. These imply that ηN improves with the increasing sodium carbonate dosage and the decreasing heating temperature.

Amorphous salts formed from rapid dehydration of multicomponent chloride and ferric sulfate brines: Implications for Mars

Science.gov (United States)

Sklute, Elizabeth C.; Rogers, A. Deanne; Gregerson, Jason C.; Jensen, Heidi B.; Reeder, Richard J.; Dyar, M. Darby

2018-03-01

Salts with high hydration states have the potential to maintain high levels of relative humidity (RH) in the near subsurface of Mars, even at moderate temperatures. These conditions could promote deliquescence of lower hydrates of ferric sulfate, chlorides, and other salts. Previous work on deliquesced ferric sulfates has shown that when these materials undergo rapid dehydration, such as that which would occur upon exposure to present day Martian surface conditions, an amorphous phase forms. However, the fate of deliquesced halides or mixed ferric sulfate-bearing brines are presently unknown. Here we present results of rapid dehydration experiments on Ca-, Na-, Mg- and Fe-chloride brines and multicomponent (Fe2(SO4)3 ± Ca, Na, Mg, Fe, Cl, HCO3) brines at ∼21 °C, and characterize the dehydration products using visible/near-infrared (VNIR) reflectance spectroscopy, mid-infrared attenuated total reflectance spectroscopy, and X-ray diffraction (XRD) analysis. We find that rapid dehydration of many multicomponent brines can form amorphous solids or solids with an amorphous component, and that the presence of other elements affects the persistence of the amorphous phase under RH fluctuations. Of the pure chloride brines, only Fe-chloride formed an amorphous solid. XRD patterns of the multicomponent amorphous salts show changes in position, shape, and magnitude of the characteristic diffuse scattering observed in all amorphous materials that could be used to help constrain the composition of the amorphous salt. Amorphous salts deliquesce at lower RH values compared to their crystalline counterparts, opening up the possibility of their role in potential deliquescence-related geologic phenomena such as recurring slope lineae (RSLs) or soil induration. This work suggests that a wide range of aqueous mixed salt solutions can lead to the formation of amorphous salts and are possible for Mars; detailed studies of the formation mechanisms, stability and transformation

Amorphous salts formed from rapid dehydration of multicomponent chloride and ferric sulfate brines: Implications for Mars

Science.gov (United States)

Sklute, Elizabeth C.; Rogers, A. Deanne; Gregerson, Jason C.; Jensen, Heidi B.; Reeder, Richard J.; Dyar, M. Darby

2018-01-01

Salts with high hydration states have the potential to maintain high levels of relative humidity (RH) in the near subsurface of Mars, even at moderate temperatures. These conditions could promote deliquescence of lower hydrates of ferric sulfate, chlorides, and other salts. Previous work on deliquesced ferric sulfates has shown that when these materials undergo rapid dehydration, such as that which would occur upon exposure to present day Martian surface conditions, an amorphous phase forms. However, the fate of deliquesced halides or mixed ferric sulfate-bearing brines are presently unknown. Here we present results of rapid dehydration experiments on Ca–, Na–, Mg– and Fe–chloride brines and multi-component (Fe2 (SO4)3 ± Ca, Na, Mg, Fe, Cl, HCO3) brines at ∼21°C, and characterize the dehydration products using visible/near-infrared (VNIR) reflectance spectroscopy, mid-infrared attenuated total reflectance spectroscopy, and X-ray diffraction (XRD) analysis. We find that rapid dehydration of many multicomponent brines can form amorphous solids or solids with an amorphous component, and that the presence of other elements affects the persistence of the amorphous phase under RH fluctuations. Of the pure chloride brines, only Fe–chloride formed an amorphous solid. XRD patterns of the multicomponent amorphous salts show changes in position, shape, and magnitude of the characteristic diffuse scattering observed in all amorphous materials that could be used to help constrain the composition of the amorphous salt. Amorphous salts deliquesce at lower RH values compared to their crystalline counterparts, opening up the possibility of their role in potential deliquescence-related geologic phenomena such as recurring slope lineae (RSLs) or soil induration. This work suggests that a wide range of aqueous mixed salt solutions can lead to the formation of amorphous salts and are possible for Mars; detailed studies of the formation mechanisms, stability and

Amorphous salts formed from rapid dehydration of multicomponent chloride and ferric sulfate brines: Implications for Mars.

Science.gov (United States)

Sklute, Elizabeth C; Rogers, A Deanne; Gregerson, Jason C; Jensen, Heidi B; Reeder, Richard J; Dyar, M Darby

2018-03-01

Salts with high hydration states have the potential to maintain high levels of relative humidity (RH) in the near subsurface of Mars, even at moderate temperatures. These conditions could promote deliquescence of lower hydrates of ferric sulfate, chlorides, and other salts. Previous work on deliquesced ferric sulfates has shown that when these materials undergo rapid dehydration, such as that which would occur upon exposure to present day Martian surface conditions, an amorphous phase forms. However, the fate of deliquesced halides or mixed ferric sulfate-bearing brines are presently unknown. Here we present results of rapid dehydration experiments on Ca-, Na-, Mg- and Fe-chloride brines and multi-component (Fe 2 (SO 4 ) 3 ± Ca, Na, Mg, Fe, Cl, HCO 3 ) brines at ∼21°C, and characterize the dehydration products using visible/near-infrared (VNIR) reflectance spectroscopy, mid-infrared attenuated total reflectance spectroscopy, and X-ray diffraction (XRD) analysis. We find that rapid dehydration of many multicomponent brines can form amorphous solids or solids with an amorphous component, and that the presence of other elements affects the persistence of the amorphous phase under RH fluctuations. Of the pure chloride brines, only Fe-chloride formed an amorphous solid. XRD patterns of the multicomponent amorphous salts show changes in position, shape, and magnitude of the characteristic diffuse scattering observed in all amorphous materials that could be used to help constrain the composition of the amorphous salt. Amorphous salts deliquesce at lower RH values compared to their crystalline counterparts, opening up the possibility of their role in potential deliquescence-related geologic phenomena such as recurring slope lineae (RSLs) or soil induration. This work suggests that a wide range of aqueous mixed salt solutions can lead to the formation of amorphous salts and are possible for Mars; detailed studies of the formation mechanisms, stability and transformation

Hydrolysis of ferric chloride in solution

International Nuclear Information System (INIS)

Lussiez, G.; Beckstead, L.

1996-11-01

The Detox trademark process uses concentrated ferric chloride and small amounts of catalysts to oxidize organic compounds. It is under consideration for oxidizing transuranic organic wastes. Although the solution is reused extensively, at some point it will reach the acceptable limit of radioactivity or maximum solubility of the radioisotopes. This solution could be cemented, but the volume would be increased substantially because of the poor compatibility of chlorides and cement. A process has been developed that recovers the chloride ions as HCl and either minimizes the volume of radioactive waste or permits recycling of the radioactive chlorides. The process involves a two-step hydrolysis at atmospheric pressure, or preferably under a slight vacuum, and relatively low temperature, about 200 degrees C. During the first step of the process, hydrolysis occurs according to the reaction below: FeCl 3 liquid + H 2 O → FeOCl solid + 2 HCl gas During the second step, the hot, solid, iron oxychloride is sprayed with water or placed in contact with steam, and hydrolysis proceeds to the iron oxide according to the following reaction: 2 FeOCl solid + H 2 O → Fe 2 O 3 solid + 2 HCl gas . The iron oxide, which contains radioisotopes, can then be disposed of by cementation or encapsulation. Alternately, these chlorides can be washed off of the solids and can then either be recycled or disposed of in some other way

Effect of soil washing with only chelators or combining with ferric chloride on soil heavy metal removal and phytoavailability: Field experiments.

Science.gov (United States)

Guo, Xiaofang; Wei, Zebin; Wu, Qitang; Li, Chunping; Qian, Tianwei; Zheng, Wei

2016-03-01

In a field experiment on multi-metal contaminated soil, we investigated the efficiency of Cd, Pb, Zn, and Cu removal by only mixture of chelators (MC) or combining with FeCl3. After washing treatment, a co-cropping system was performed for heavy metals to be extracted by Sedum alfredii and to produce safe food from Zea mays. We analyzed the concentration of heavy metals in groundwater to evaluate the leashing risk of soil washing with FeCl3 and MC. Results showed that addition of FeCl3 was favorable to the removal of heavy metals in the topsoil. Metal leaching occurred mainly in rain season during the first co-cropping. The removal rates of Cd, Zn, Pb, and Cu in topsoil were 28%, 53%, 41%, and 21% with washing by FeCl3+MC after first harvest. The application of FeCl3 reduced the yield of S. alfredii and increased the metals concentration of Z. mays in first harvest. However, after amending soil, the metals concentration of Z. mays in FeCl3+MC treatment were similar to that only washing by MC. The grains and shoots of Z. mays were safe for use in feed production. Soil washing did not worsen groundwater contamination during the study period. But the concentration of Cd in groundwater was higher than the limit value of Standard concentrations for Groundwater IV. This study suggests that soil washing using FeCl3 and MC for the remediation of multi-metal contaminated soil is potential feasibility. However, the subsequent measure to improve the washed soil environment for planting crop is considered. Copyright © 2016. Published by Elsevier Ltd.

Electrochemical Applications in Metal Bioleaching.

Science.gov (United States)

Tanne, Christoph Kurt; Schippers, Axel

2017-12-10

Biohydrometallurgy comprises the recovery of metals by biologically catalyzed metal dissolution from solids in an aqueous solution. The application of this kind of bioprocessing is described as "biomining," referring to either bioleaching or biooxidation of sulfide metal ores. Acidophilic iron- and sulfur-oxidizing microorganisms are the key to successful biomining. However, minerals such as primary copper sulfides are recalcitrant to dissolution, which is probably due to their semiconductivity or passivation effects, resulting in low reaction rates. Thus, further improvements of the bioleaching process are recommendable. Mineral sulfide dissolution is based on redox reactions and can be accomplished by electrochemical technologies. The impact of electrochemistry on biohydrometallurgy affects processing as well as analytics. Electroanalysis is still the most widely used electrochemical application in mineralogical research. Electrochemical processing can contribute to bioleaching in two ways. The first approach is the coupling of a mineral sulfide to a galvanic partner or electrocatalyst (spontaneous electron transfer). This approach requires only low energy consumption and takes place without technical installations by the addition of higher redox potential minerals (mostly pyrite), carbonic material, or electrocatalytic ions (mostly silver ions). Consequently, the processed mineral (often chalcopyrite) is preferentially dissolved. The second approach is the application of electrolytic bioreactors (controlled electron transfer). The electrochemical regulation of electrolyte properties by such reactors has found most consideration. It implies the regulation of ferrous and ferric ion ratios, which further results in optimized solution redox potential, less passivation effects, and promotion of microbial activity. However, many questions remain open and it is recommended that reactor and electrode designs are improved, with the aim of finding options for simplified

High affinity (3H) β-Alanine uptake by scar margins of ferric chloride-induced epileptogenic foci in rat isocortex

International Nuclear Information System (INIS)

Robitaille, Y.; Sherwin, A.

1984-01-01

Cortical astrocytes of normal mammalian brain are endowed with a high affinity uptake system for β-Alanine which is competitively inhibited by gamma aminobutyric acid (GABA), a neurotransmitter strongly implicated in epileptogenesis. The authors evaluated ( 3 H) β-Alanine uptake by reactive astrocytes proliferating within scar of epileptogenic foci induced in rat motor cortex by microinjections of 100 mM ferric chloride. Following in vitro incubation of scar tissue with ( 3 H) β-Alanine, ultrastructural morphometry of grain patterns at 5, 30 and 120 days post injection revealed early and significant grain count increases over astroglial processes, predominantly those related to perivascular glial end-feet. Astrocytic cell body and endothelial cell counts showed a more gradual and stepwise increase. Similar data were obtained by comparing visual and edited mean astrocytic grain counts. These results suggest that the enhanced uptake of reactive astrocytes may reflect a marked decrease of inhibitory GABAergic neurons within ferric chloride-induced scars. 7 figures, 1 table

Characterization of sonicated natural zeolite/ferric chloride hexahydrate by infrared spectroscopy

Science.gov (United States)

Prasetyo, T. A. B.; Soegijono, B.

2018-03-01

The characteristics of sonicated Bayah natural zeolite with and without ferric chloride hexahydrate solution using infrared method has been studied. High intensity ultrasonic waves were exposed to the samples for 40 min, 80 min and 120 min. Infra red spectra analysis was conducted to evaluate zeolite vibrational spectrum contributions, namely, the vibrations from the framework of the zeolite, from the charge-balancing cations, and from the relatively isolated groups, such as the surface OH groups and their behavior after sonication process. An addition of FeCl3.6H2O and sonication process on natural zeolite improved secondary building units link by forming oxygen bridges and also close relationship with duration of applied high intensity ultrasonic process. Longer ultrasonic process resulted in more increment of O-H absorbance.

Iron fortification of flour with a complex ferric orthophosphate

International Nuclear Information System (INIS)

Hallberg, L.; Rossander-Hulthen, L.; Gramatkovski, E.

1989-01-01

The unexpectedly low bioavailability in humans of elemental iron powder prompted us to search for other Fe compounds suitable for Fe fortification of flour that fulfill the two requirements of insolubility in water (due to high water content of flour) and good bioavailability in humans. Systematic studies of compatibility, solubility, and bioavailability led to this study of a microcrystalline complex ferric orthophosphate (CFOP), Fe 3 H 8 (NH 4 )-(PO 4 )6.6H 2 O, a well-defined compound. This compound was labeled with 59 Fe, and the native Fe in meals was labeled with 55 FeCl3. The ratio of absorbed 59 Fe to absorbed 55 Fe is a direct measure of the fraction of CFOP that joins the nonheme Fe pool and that is made potentially available for absorption. The relative bioavailability of CFOP varied from 30% to 60% when labeled wheat rolls were served with different meals. The CFOP meets practical requirements of an Fe fortificant for flour well, with regard to both compatibility and bioavailability in humans

The inhibitory effect of metals and other ions on acid phosphatase activity from Vigna aconitifolia seeds.

Science.gov (United States)

Srivastava, Pramod Kumar; Anand, Asha

2015-01-01

Sensitivity of acid phosphatase from Vigna aconitifolia seeds to metal ions, fluoride, and phosphate was examined. All the effectors had different degree of inhibitory effect on the enzyme. Among metal ions, molybdate and ferric ion were observed to be most potent inhibitors and both exhibited mixed type of inhibition. Acid phosphatase activity was inhibited by Cu2+ in a noncompetitive manner. Zn and Mn showed mild inhibition on the enzyme activity. Inhibition kinetics analysis explored molybdate as a potent inhibitor for acid phosphatase in comparison with other effectors used in this study. Fluoride was the next most strong inhibitor for the enzyme activity, and caused a mixed type of inhibition. Phosphate inhibited the enzyme competitively, which demonstrates that inhibition due to phosphate is one of the regulatory factors for enzyme activity.

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.)

Studying Equilibrium in the Chemical Reaction between Ferric and Iodide Ions in Solution Using a Simple and Inexpensive Approach

Science.gov (United States)

Nikolaychuk, Pavel Anatolyevich; Kuvaeva, Alyona Olegovna

2016-01-01

A laboratory experiment on the study of the chemical equilibrium based on the reaction between ferric and iodide ions in solution with the formation of ferrous ions, free iodine, and triiodide ions is developed. The total concentration of iodide and triiodide ions in the reaction mixture during the reaction is determined by the argentometric…

Novel regeneration method for phosphate loaded granular ferric (hydr)oxide--a contribution to phosphorus recycling.

Science.gov (United States)

Kunaschk, Marco; Schmalz, Viktor; Dietrich, Norman; Dittmar, Thomas; Worch, Eckhard

2015-03-15

At a progressive rate, small wastewater treatment plants in rural areas need to be equipped with an additional phosphorus removal stage in order to achieve a good chemical status in the receiving natural water bodies. A conventional regeneration method for ferric (hydr)oxides such as phosphate specific adsorbents, which can be applied to remove and recover phosphorus in fixed bed filters, was investigated and improved. It was shown that a loss of up to 85% of the initial capacity can be observed when regeneration with 1 M NaOH is implemented. The losses are caused by surface blocking with different calcium-containing compounds as revealed by an EDX analysis. These blocking compounds could be removed completely with an additional acidic regeneration step at pH = 2.5. During the alkaline desorption that followed, complete phosphorus removal and a full recovery of the adsorption capacity were achieved for goethite-rich Bayoxide(®) E 33 HC (E33HC) and akaganéite-rich GEH(®) 104 (GEH). The regeneration procedure was repeated up to eight times without any signs of further decline in the phosphate adsorption capacity or any changes in the specific surface area or pore size distribution of the adsorbent. In contrast to GEH and E33HC, ferric hydroxide- and calcite-rich FerroSorp(®) Plus (FSP) was partly dissolved during acid treatment. Copyright © 2015 Elsevier Ltd. All rights reserved.

Performance Characteristics of Bio-Inspired Metal Nanostructures as Surface-Enhanced Raman Scattered (SERS) Substrates.

Science.gov (United States)

Areizaga-Martinez, Hector I; Kravchenko, Ivan; Lavrik, Nickolay V; Sepaniak, Michael J; Hernández-Rivera, Samuel P; De Jesús, Marco A

2016-09-01

The fabrication of high-performance plasmonic nanomaterials for bio-sensing and trace chemical detection is a field of intense theoretical and experimental research. The use of metal-silicon nanopillar arrays as analytical sensors has been reported with reasonable results in recent years. The use of bio-inspired nanocomposite structures that follow the Fibonacci numerical architecture offers the opportunity to develop nanostructures with theoretically higher and more reproducible plasmonic fields over extended areas. The work presented here describes the nanofabrication process for a series of 40 µm × 40 µm bio-inspired arrays classified as asymmetric fractals (sunflower seeds and romanesco broccoli), bilaterally symmetric (acacia leaves and honeycombs), and radially symmetric (such as orchids and lily flowers) using electron beam lithography. In addition, analytical capabilities were evaluated using surface-enhanced Raman scattering (SERS). The substrate characterization and SERS performance of the developed substrates as the strategies to assess the design performance are presented and discussed. © The Author(s) 2016.

Broadband and wide angle near-unity absorption in graphene-insulator-metal thin film stacks

Science.gov (United States)

Zhang, H. J.; Zheng, G. G.; Chen, Y. Y.; Xu, L. H.

2018-05-01

Broadband unity absorption in graphene-insulator-metal (GIM) structures is demonstrated in the visible (VIS) and near-infrared (NIR) spectra. The spectral characteristics possess broadband absorption peaks, by simply choosing a stack of GIM, while no nanofabrication steps and patterning are required, and thus can be easily fabricated to cover a large area. The electromagnetic (EM) waves can be entirely trapped and the absorption can be greatly enhanced are verified with the finite-difference time-domain (FDTD) and rigorous coupled wave analysis (RCWA) methods. The position and the number of the absorption peak can be totally controlled by adjusting the thickness of the insulator layer. The proposed absorber maintains high absorption (above 90%) for both transverse electric (TE) and transverse magnetic (TM) polarizations, and for angles of incidence up to 80°. This work opens up a promising approach to realize perfect absorption (PA) with ultra-thin film, which could implicate many potential applications in optical detection and optoelectronic devices.

Optical properties and electronic transitions of zinc oxide, ferric oxide, cerium oxide, and samarium oxide in the ultraviolet and extreme ultraviolet

DEFF Research Database (Denmark)

Pauly, N; Yubero, F; Espinós, J P

2017-01-01

Optical properties and electronic transitions of four oxides, namely zinc oxide, ferric oxide, cerium oxide, and samarium oxide, are determined in the ultraviolet and extreme ultraviolet by reflection electron energy loss spectroscopy using primary electron energies in the range 0.3-2.0 ke...

Treatment of rheumatoid synovitis of the knee with intraarticular injection of dysprosium 165-ferric hydroxide macroaggregates

International Nuclear Information System (INIS)

Sledge, C.B.; Zuckerman, J.D.; Zalutsky, M.R.

1986-01-01

One hundred eight knees of 93 patients with seropositive rheumatoid arthritis and persistent synovitis of the knee were treated with an intraarticular injection of 270 mCi of dysprosium 165 bound to ferric hydroxide macroaggregate. Leakage of radioactivity from the injected joint was minimal. Mean leakage to the venous blood 3 hours after injection was 0.11% of the injected dose; this corresponds to a mean whole body dose of 0.2 rads. Mean leakage to the liver 24 hours after injection was 0.64% of the injected dose; this corresponds to a mean liver dose of 3.2 rads. In 7 additional patients examined, there was negligible or near negligible activity found in the draining inguinal lymph nodes. One-year followup was possible for 74 knees (63 patients). Sixty-one percent of the knees had good results, 23% had fair results, and 16% had poor results. There was a direct correlation between the radiographic stage and response to treatment. In knees with stage I radiographic changes, 72% showed good results; 93% showed improvement. In knees with stage II changes, 59% showed good results; 81% showed improvement. These preliminary results indicate that dysprosium 165-ferric hydroxide macroaggregate is an effective agent for radiation synovectomy. The low leakage rates observed offer a definite advantage over agents previously used

Synthesis and characterization of redox-active ferric nontronite

Energy Technology Data Exchange (ETDEWEB)

Ilgen, A. G.; Kukkadapu, R. K.; Dunphy, D. R.; Artyushkova, K.; Cerrato, J. M.; Kruichak, J. N.; Janish, M. T.; Sun, C. J.; Argo, J. M.; Washington, R. E.

2017-10-01

Heterogeneous redox reactions on clay mineral surfaces control mobility and bioavailability of redox-sensitive nutrients and contaminants. Iron (Fe) residing in clay mineral structures can either catalyze or directly participate in redox reactions; however, chemical controls over its reactivity are not fully understood. In our previous work we demonstrated that converting a minor portion of Fe(III) to Fe(II) (partial reduction) in the octahedral sheet of natural Fe-rich clay mineral nontronite (NAu-1) activates its surface, making it redox-active. In this study we produced and characterized synthetic ferric nontronite (SIP), highlighting structural and chemical similarities and differences between this synthetic nontronite and its natural counterpart NAu-1, and probed whether mineral surface is redox-active by reacting it with arsenic As(III) under oxic and anoxic conditions. We demonstrate that synthetic nontronite SIP undergoes the same activation as natural nontronite NAu-1 following the partial reduction treatment. Similar to NAu-1, SIP oxidized As(III) to As(V) under both oxic (catalytic pathway) and anoxic (direct oxidation) conditions. The similar reactivity trends observed for synthetic nontronite and its natural counterpart make SIP an appropriate analog for laboratory studies. The development of chemically pure analogs for ubiquitous soil minerals will allow for systematic research of the fundamental properties of these minerals.

Soft-lithographic patterning of room termperature-sintering Ag Nanoparticles on foil

NARCIS (Netherlands)

Moonen, P.; Bat, E.; Voorthuijzen, W. Pim; Huskens, Jurriaan

2013-01-01

Room temperature-sintering, poly(acrylic acid)-capped silver nanoparticles (Ag-PAA NPs) were used in a wide range of nanofabrication methods to form metallic silver microstructures on flexible poly(ethylene terephthalate) (PET) substrates. Silver wires on top of PET foil were patterned by

Soft-lithographic patterning of room temperaturesintering Ag nanoparticles on foil

NARCIS (Netherlands)

Moonen,P.F.; Bat,E.; Voorthuijzen, W.P.; Huskens, J.

2013-01-01

Room temperature-sintering, poly(acrylic acid)-capped silver nanoparticles (Ag-PAA NPs) were used in a wide range of nanofabrication methods to form metallic silver microstructures on flexible poly(ethylene terephthalate) (PET) substrates. Silver wires on top of PET foil were patterned by

3D plasmonic nanostar structures for recyclable SERS applications

DEFF Research Database (Denmark)

Chirumamilla, Manohar; Gopalakrishnan, Anisha; Toma, Andrea

2015-01-01

Nanofabrication of metallic nanostructures/nanoparticles enables the detection of analyte molecules at ultra-low concentrations with the aid of plasmon induced hot-spots. The high fabrication cost and large fabrication time of nanostructures limit their usage in practical applications. Here we pr...

Towards high purity nanostructures from electron beam induced deposition of platinum

NARCIS (Netherlands)

Botman, A.P.J.M.

2009-01-01

Electron beam induced deposition (EBID) is a novel nanofabrication technique allowing the rapid prototyping of three-dimensional nanodevices and the metallic wiring of nanostructures, and is a promising technique for many applications in nanoresearch. EBID is a process wherein a precursor molecule

Photocatalytic Reduction of Hexavalent Chromium Induced by Photolysis of Ferric/tartrate Complex

Energy Technology Data Exchange (ETDEWEB)

Feng, Xianghua; Ding, Shimin; Zhang, Lixian [Yangtze Normal Univ., Fuling (China)

2012-11-15

Photocatalytic reduction of hexavalent chromium (Cr(VI)) in ferric-tartrate system under irradiation of visible light was investigated. Effects of light resources, initial pH value and initial concentration of various reactants on Cr(VI) photocatalytic reduction were studied. Photoreaction kinetics was discussed and a possible photochemical pathway was proposed. The results indicate that Fe(III)-tartrate system is able to rapidly and effectively photocatalytically reduce Cr(VI) utilizing visible light. Initial pH variations results in the concentration changes of Fe(III)-tartrate complex in this system, and pH at 3.0 is optimal for Cr(VI) photocatalytic reduction. Efficiency of Cr(VI) photocatalytic reduction increases with increasing initial concentrations of Cr(VI), Fe(III) and tartrate. Kinetics analysis indicates that initial Fe(III) concentration affects Cr(VI) photoreduction most significantly.

Photocatalytic Reduction of Hexavalent Chromium Induced by Photolysis of Ferric/tartrate Complex

International Nuclear Information System (INIS)

Feng, Xianghua; Ding, Shimin; Zhang, Lixian

2012-01-01

Photocatalytic reduction of hexavalent chromium (Cr(VI)) in ferric-tartrate system under irradiation of visible light was investigated. Effects of light resources, initial pH value and initial concentration of various reactants on Cr(VI) photocatalytic reduction were studied. Photoreaction kinetics was discussed and a possible photochemical pathway was proposed. The results indicate that Fe(III)-tartrate system is able to rapidly and effectively photocatalytically reduce Cr(VI) utilizing visible light. Initial pH variations results in the concentration changes of Fe(III)-tartrate complex in this system, and pH at 3.0 is optimal for Cr(VI) photocatalytic reduction. Efficiency of Cr(VI) photocatalytic reduction increases with increasing initial concentrations of Cr(VI), Fe(III) and tartrate. Kinetics analysis indicates that initial Fe(III) concentration affects Cr(VI) photoreduction most significantly

Implementation of ferric hydroxide-based media for removal of toxic metalloids

Science.gov (United States)

Szlachta, Małgorzata; Wójtowicz, Patryk

2017-11-01

Effective removal of inorganic arsenic species is possible by application of the sorption technique with the use of iron-based sorbents. This study investigates the removal of arsenic(III) and arsenic(V) from an aqueous solution by application of a granular ferric hydroxide-based sorbent. The performance of tested media was evaluated based on the batch and fixed-bed adsorption studies. The efficiency of the process was determined with various treatment times, adsorbent doses, initial concentrations of arsenic and various solution temperatures. The obtained adsorption data were fitted with pseudo-first and second-order kinetic models and Langmuir and Freundlich isotherm equations. It was observed that the overall arsenite removal was lower when compared to the arsenate, and all tested operating parameters influenced the process efficiency. The experiments under dynamic conditions showed high treatment capacity and stability of tested adsorbent over a long period of time.

Performance evaluation of ALCAN-AASF50-ferric coated activated alumina and granular ferric hydroxide (GFH) for arsenic removal in the presence of competitive ions in an active well :Kirtland field trial - initial studies.

Energy Technology Data Exchange (ETDEWEB)

Neidel, Linnah L.; Krumhansl, James Lee; Siegel, Malcolm Dean; Khandaker, Nadim Reza

2006-01-01

This report documents a field trial program carried out at Well No.15 located at Kirtland Air Force Base, Albuquerque, New Mexico, to evaluate the performance of two relatively new arsenic removal media, ALCAN-AASF50 (ferric coated activated alumina) and granular ferric hydroxide (US Filter-GFH). The field trial program showed that both media were able to remove arsenate and meet the new total arsenic maximum contaminant level (MCL) in drinking water of 10 {micro}g/L. The arsenate removal capacity was defined at a breakthrough effluent concentration of 5 {micro}g/L arsenic (50% of the arsenic MCL of 10 {micro}g/L). At an influent pH of 8.1 {+-} 0.4, the arsenate removal capacity of AASF50 was 33.5 mg As(V)/L of dry media (29.9 {micro}g As(V)/g of media on a dry basis). At an influent pH of 7.2 {+-} 0.3, the arsenate removal capacity of GFH was 155 mg As(V)/L of wet media (286 {micro}g As(V)/g of media on a dry basis). Silicate, fluoride, and bicarbonate ions are removed by ALCAN AASF50. Chloride, nitrate, and sulfate ions were not removed by AASF50. The GFH media also removed silicate and bicarbonate ions; however, it did not remove fluoride, chloride, nitrate, and sulfate ions. Differences in the media performance partly reflect the variations in the feed-water pH between the 2 tests. Both the exhausted AASF50 and GFH media passed the Toxicity Characteristic Leaching Procedure (TCLP) test with respect to arsenic and therefore could be disposed as nonhazardous waste.

Prevention of Acid Mine Drainage Through Complexation of Ferric Iron by Soluble Microbial Growth Products

Science.gov (United States)

Pandey, S.; Yacob, T. W.; Silverstein, J.; Rajaram, H.; Minchow, K.; Basta, J.

2011-12-01

Acid mine drainage (AMD) is a widespread environmental problem with deleterious impacts on water quality in streams and watersheds. AMD is generated largely by the oxidation of metal sulfides (i.e. pyrite) by ferric iron. This abiotic reaction is catalyzed by conversion of ferrous to ferric iron by iron and sulfur oxidizing microorganisms. Biostimulation is currently being investigated as an attempt to inhibit the oxidation of pyrite and growth of iron oxidizing bacteria through addition of organic carbon. This may stimulate growth of indigenous communities of acidophilic heterotrophic bacteria to compete for oxygen. The goal of this research is to investigate a secondary mechanism associated with carbon addition: complexation of free Fe(III) by soluble microbial growth products (SMPs) produced by microorganisms growing in waste rock. Exploratory research at the laboratory scale examined the effect of soluble microbial products (SMPs) on the kinetics of oxidation of pure pyrite during shaker flask experiments. The results confirmed a decrease in the rate of pyrite oxidation that was dependent upon the concentration of SMPs in solution. We are using these data to verify results from a pyrite oxidation model that accounts for SMPs. This reactor model involves differential-algebraic equations incorporating total component mass balances and mass action laws for equilibrium reactions. Species concentrations determined in each time step are applied to abiotic pyrite oxidation rate expressions from the literature to determine the evolution of total component concentrations. The model was embedded in a parameter estimation algorithm to determine the reactive surface area of pyrite in an abiotic control experiment, yielding an optimized value of 0.0037 m2. The optimized model exhibited similar behavior to the experiment for this case; the root mean squared of residuals for Fe(III) was calculated to be 7.58 x 10-4 M, which is several orders of magnitude less than the actual

Dietary bioavailability of Cu adsorbed to colloidal hydrous ferric oxide

Science.gov (United States)

Cain, Daniel J.; Croteau, Marie-Noële; Fuller, Christopher C.

2013-01-01

The dietary bioavailability of copper (Cu) adsorbed to synthetic colloidal hydrous ferric oxide (HFO) was evaluated from the assimilation of 65Cu by two benthic grazers, a gastropod and a larval mayfly. HFO was synthesized, labeled with 65Cu to achieve a Cu/Fe ratio comparable to that determined in naturally formed HFO, and then aged. The labeled colloids were mixed with a food source (the diatom Nitzschia palea) to yield dietary 65Cu concentrations ranging from 211 to 2204 nmol/g (dry weight). Animals were pulse fed the contaminated diet and assimilation of 65Cu from HFO was determined following 1–3 days of depuration. Mass transfer of 65Cu from HFO to the diatom was less than 1%, indicating that HFO was the source of 65Cu to the grazers. Estimates of assimilation efficiency indicated that the majority of Cu ingested as HFO was assimilated (values >70%), implying that colloidal HFO potentially represents a source of dietary Cu to benthic grazers, especially where there is active formation and infiltration of these particles into benthic substrates.

Ligand Exchange Kinetics of Environmentally Relevant Metals

Energy Technology Data Exchange (ETDEWEB)

Panasci, Adele Frances [Univ. of California, Davis, CA (United States)

2014-07-15

The interactions of ground water with minerals and contaminants are of broad interest for geochemists but are not well understood. Experiments on the molecular scale can determine reaction parameters (i.e. rates of ligand exchange, activation entropy, activation entropy, and activation volume) that can be used in computations to gain insight into reactions that occur in natural groundwaters. Experiments to determine the rate of isotopic ligand exchange for three environmentally relevant metals, rhodium (Rh), iron (Fe), and neptunium (Np), are described. Many environmental transformations of metals (e.g. reduction) in soil occur at trivalent centers, Fe(III) in particular. Contaminant ions absorb to mineral surfaces via ligand exchange, and the reversal of this reaction can be dangerous, releasing contaminants into the environment. Ferric iron is difficult to study spectroscopically because most of its complexes are paramagnetic and are generally reactive toward ligand exchange; therefore, Rh(III), which is diamagnetic and less reactive, was used to study substitution reactions that are analogous to those that occur on mineral oxide surfaces. Studies on both Np(V) and Np(VI) are important in their own right, as ²³⁷Np is a radioactive transuranic element with a half-life of 2 million years.

[Bioregeneration of the solutions obtained during the leaching of nonferrous metals from waste slag by acidophilic microorganisms].

Science.gov (United States)

Fomchenko, N V; Murav'ev, M I; Kondrat'eva, T F

2014-01-01

The bioregeneration of the solutions obtained after the leaching of copper and zinc from waste slag by sulfuric solutions of ferric sulfate is examined. For bioregeneration, associations of mesophilic and moderately thermqophilic acidophilic chemolithotrophic microorganisms were made. It has been shown that the complete oxidation of iron ions in solutions obtained after the leaching of nonferrous metals from waste slag is possible at a dilution of the pregnant solution with a nutrient medium. It has been found that the maximal rate of oxidation of iron ions is observed at the use of a mesophilic association of microorganisms at a threefold dilution of the pregnant solution with a nutrient medium. The application ofbioregeneration during the production of nonferrous metals from both waste and converter slags would make it possible to approach the technology of their processing using the closed cycle of workflows.

Investigation on reusing water treatment residuals to remedy soil contaminated with multiple metals in Baiyin, China

International Nuclear Information System (INIS)

Wang, Changhui; Zhao, Yuanyuan; Pei, Yuansheng

2012-01-01

Highlights: ► Fe/Al water treatment residuals (FARs) can stabilize As, Pb, Ni, Zn, Cr and Cu. ► FARs cannot stabilize Ba and Cd. ► The properties of FARs and soil affect the FARs’ ability of stabilizing metals. - Abstract: In this work, the remediation of soils contaminated with multiple metals using ferric and alum water treatment residuals (FARs) in Baiyin, China, was investigated. The results of metals fractionation indicated that after the soil was treated with FARs, arsenic (As), lead (Pb), nickel (Ni), zinc (Zn) and copper (Cu) could be transformed into more stable forms, i.e., As bound in crystalline Fe/Al oxides and other metals in the oxidable and residual forms. However, the forms of chromium (Cr) and cadmium (Cd) were unaffected. Interestingly, due to the effect of FARs, barium (Ba) was predominantly transformed into more mobile forms. The bioaccessibility extraction test demonstrated that the FARs reduced the bioaccessibility of As by 25%, followed by Cu, Cr, Zn, Ni and Pb. The bioaccessibility of Cd and Ba were increased; in particular, there was an increase of 41% for Ba at the end of the test. In conclusion, the FARs can be used to remedy soil contaminated with multiple metals, but comprehensive studies are needed before practical applications of this work.

Engineered Metallic Nanostructures: Fabrication, Characterization, and Applications

Science.gov (United States)

Bohloul, Arash

Metallic nanostructures have garnered a great deal of attention due to their fascinating optical properties, which differ from the bulk metal. They have been proven to exceed expectations in wide variety of applications including chemical and biological sensing. Nevertheless, high-throughput and low cost nanofabrication techniques are required to implant metallic nanostructures in widespread applications. With that vision, this thesis presents a versatile and reliable method for scalable fabrication of gold nanostructures. In this approach, a plasma-treated ordered array of polystyrene nanospheres acts as an initial mask. The key step in this process is the vapor-deposition of nickel as a sacrificial mask. Thereby, gold nanostructures are directly formed on the substrate through the nickel mask. This is an easy, powerful, and straightforward method that offers several degrees of freedom to precisely control the shape and size of nanostructures. We made a library of nanostructures including gold nanocrescents, double crescents, nanorings, and nanodisks with the ability to tune the size in the range of 150 to 650 nm. The fabricated nanostructures are highly packed and uniformly cover the centimeter scale substrate. The optical properties of metallic nanostructures were extensively studied by a combination of UV-Vis-NIR and Fourier transform infrared (FTIR) spectroscopies, and correlation between optical response and geometrical parameters were investigated. In the next part of this thesis, highly sensitive surface enhanced infrared absorption (SEIRA) analysis was demonstrated on gold nanocrescent arrays. Theoretical modeling was confirmed that these substrates provide highly dense and strong hot-spots over the substrate, which is required for surface enhanced spectroscopic studies. Gold nanocrescent arrays exhibit highly tunable plasmon resonance to cover desired molecular vibrational bands. These substrates experimentally illustrated 3 orders of magnitude

Cost-minimization analysis favours intravenous ferric carboxymaltose over ferric sucrose for the ambulatory treatment of severe iron deficiency.

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Xavier Calvet

Full Text Available OBJECTIVE: Intravenous iron is widely used to treat iron deficiency in day-care units. Ferric carboxymaltose (FCM allows administration of larger iron doses than iron sucrose (IS in each infusion (1000 mg vs. 200 mg. As FCM reduces the number of infusions required but is more expensive, we performed a cost-minimization analysis to compare the cost impact of the two drugs. MATERIALS AND METHODS: The number of infusions and the iron dose of 111 consecutive patients who received intravenous iron at a gastrointestinal diseases day-care unit from 8/2007 to 7/2008 were retrospectively obtained. Costs of intravenous iron drugs were obtained from the Spanish regulatory agencies. The accounting department of the Hospital determined hospital direct and indirect costs for outpatient iron infusion. Non-hospital direct costs were calculated on the basis of patient interviews. In the pharmacoeconomic model, base case mean costs per patient were calculated for administering 1000 mg of iron per infusion using FCM or 200 mg using IS. Sensitivity analysis and Monte Carlo simulation were performed. RESULTS: Under baseline assumptions, the estimated cost of iron infusion per patient and year was €304 for IS and €274 for FCM, a difference of €30 in favour of FCM. Adding non-hospital direct costs to the model increased the difference to €67 (€354 for IS vs. €287 for FCM. A Monte Carlo simulation taking into account non-hospital direct costs favoured the use of FCM in 97% of simulations. CONCLUSION: In this pharmacoeconomic analysis, FCM infusion reduced the costs of iron infusion at a gastrointestinal day-care unit.

Segmentation of the potential consumers of ferric medicines based on data of iron deficiency anemia prevalence

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Z. N. Mnushko

2013-08-01

Full Text Available INTRODUCTION. According to WHO 3.6 billion of people on the planet have latent iron deficiency and another 1.8 billion of people suffer from iron deficiency anemia (IDA. According to the Ministry of Health of Ukraine information the prevalence and the incidence of iron deficiency anemia is 1163.9 and 404.5 per 100 000 persons, respectively. However, this information is only clinically confirmed cases of IDA. The largest share in the structure of morbidity has the latent iron deficiency, which is characterized by less prominent clinical manifestations. Treatment of IDA aimed not only at addressing anemia as a symptom, but also at the elimination of iron deficiency and replenishment of its reserves in the organism, which can be achieved by taking ferric drugs. Today ferric drugs market is characterized by high leveled competition, stable demand and a wide range of products. Therefore, an important issue in the study of the market is to find the best ways to determining its potential capacity to expand the marketing potential and to provide iron supplementation as many consumers who need treatment and prevention of iron deficiency. GOAL OF THE STUDY. the segmentation of the population that needs treatment and prevention of iron deficiency on the basis of the etiological factors that cause development of anemia, based on official statistics on morbidity. MATERIALS AND METODS. According to the standard classification of the iron deficiency we have identified four main groups of etiological factors that lead to the development of IDA: bleeding, iron malabsorption, increased body's need for iron, as well as complicated genesis factors. In order to determine the total number of individual segments we have analyzed the reports of the State Statistics Committee of Ukraine, Health Statistics Centre of Ministry of Health of Ukraine, as well as electronic database of medical statistics “Health for All”. RESULTS AND DISCUSSION. According to the estimates

Hydrous Ferric Oxides in Sediment Catalyze Formation of Reactive Oxygen Species during Sulfide Oxidation

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Sarah A. Murphy

2016-11-01

Full Text Available Abstract: This article describes the formation of reactive oxygen species as a result of the oxidation of dissolved sulfide by Fe(III-containing sediments suspended in oxygenated seawater over the pH range 7.00 and 8.25. Sediment samples were obtained from across the coastal littoral zone in South Carolina, US, at locations from the beach edge to the forested edge of a Spartina dominated estuarine salt marsh and suspended in aerated seawater. Reactive oxygen species (superoxide and hydrogen peroxide production was initiated in sediment suspensions by the addition of sodium bisulfide. The subsequent loss of HS-, formation of Fe(II (as indicated by Ferrozine, and superoxide and hydrogen peroxide were monitored over time. The concentration of superoxide rose from the baseline and then persisted at an apparent steady state concentration of approximately 500 nanomolar at pH 8.25 and 200 nanomolar at pH 7.00 respectively until >97% hydrogen sulfide was consumed. Measured superoxide was used to predict hydrogen peroxide yield based on superoxide dismutation. Dismutation alone quantitatively predicted hydrogen peroxide formation at pH 8.25 but over predicted hydrogen peroxide formation at pH 7 by a factor of approximately 102. Experiments conducted with episodic spikes of added hydrogen peroxide indicated rapid hydrogen peroxide consumption could account for its apparent low instantaneous yield, presumably the result of its reaction with Fe(II species, polysulfides or bisulfite. All sediment samples were characterized for total Fe, Cu, Mn, Ni, Co and hydrous ferric oxide by acid extraction followed by mass spectrometric or spectroscopic characterization. Sediments with the highest loadings of hydrous ferric oxide were the only sediments that produced significant dissolved Fe(II species or ROS as a result of sulfide exposure.

Structural characterization of ferric hemoglobins from three antarctic fish species of the suborder notothenioidei.

Science.gov (United States)

Vergara, Alessandro; Franzese, Marisa; Merlino, Antonello; Vitagliano, Luigi; Verde, Cinzia; di Prisco, Guido; Lee, H Caroline; Peisach, Jack; Mazzarella, Lelio

2007-10-15

Spontaneous autoxidation of tetrameric Hbs leads to the formation of Fe (III) forms, whose physiological role is not fully understood. Here we report structural characterization by EPR of the oxidized states of tetrameric Hbs isolated from the Antarctic fish species Trematomus bernacchii, Trematomus newnesi, and Gymnodraco acuticeps, as well as the x-ray crystal structure of oxidized Trematomus bernacchii Hb, redetermined at high resolution. The oxidation of these Hbs leads to formation of states that were not usually detected in previous analyses of tetrameric Hbs. In addition to the commonly found aquo-met and hydroxy-met species, EPR analyses show that two distinct hemichromes coexist at physiological pH, referred to as hemichromes I and II, respectively. Together with the high-resolution crystal structure (1.5 A) of T. bernacchii and a survey of data available for other heme proteins, hemichrome I was assigned by x-ray crystallography and by EPR as a bis-His complex with a distorted geometry, whereas hemichrome II is a less constrained (cytochrome b5-like) bis-His complex. In four of the five Antartic fish Hbs examined, hemichrome I is the major form. EPR shows that for HbCTn, the amount of hemichrome I is substantially reduced. In addition, the concomitant presence of a penta-coordinated high-spin Fe (III) species, to our knowledge never reported before for a wild-type tetrameric Hb, was detected. A molecular modeling investigation demonstrates that the presence of the bulkier Ile in position 67beta in HbCTn in place of Val as in the other four Hbs impairs the formation of hemichrome I, thus favoring the formation of the ferric penta-coordinated species. Altogether the data show that ferric states commonly associated with monomeric and dimeric Hbs are also found in tetrameric Hbs.

The Porphyromonas gingivalis ferric uptake regulator orthologue binds hemin and regulates hemin-responsive biofilm development.

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Catherine A Butler

Full Text Available Porphyromonas gingivalis is a Gram-negative pathogen associated with the biofilm-mediated disease chronic periodontitis. P. gingivalis biofilm formation is dependent on environmental heme for which P. gingivalis has an obligate requirement as it is unable to synthesize protoporphyrin IX de novo, hence P. gingivalis transports iron and heme liberated from the human host. Homeostasis of a variety of transition metal ions is often mediated in Gram-negative bacteria at the transcriptional level by members of the Ferric Uptake Regulator (Fur superfamily. P. gingivalis has a single predicted Fur superfamily orthologue which we have designated Har (heme associated regulator. Recombinant Har formed dimers in the presence of Zn2+ and bound one hemin molecule per monomer with high affinity (Kd of 0.23 µM. The binding of hemin resulted in conformational changes of Zn(IIHar and residue 97Cys was involved in hemin binding as part of a predicted -97C-98P-99L- hemin binding motif. The expression of 35 genes was down-regulated and 9 up-regulated in a Har mutant (ECR455 relative to wild-type. Twenty six of the down-regulated genes were previously found to be up-regulated in P. gingivalis grown as a biofilm and 11 were up-regulated under hemin limitation. A truncated Zn(IIHar bound the promoter region of dnaA (PGN_0001, one of the up-regulated genes in the ECR455 mutant. This binding decreased as hemin concentration increased which was consistent with gene expression being regulated by hemin availability. ECR455 formed significantly less biofilm than the wild-type and unlike wild-type biofilm formation was independent of hemin availability. P. gingivalis possesses a hemin-binding Fur orthologue that regulates hemin-dependent biofilm formation.

Surface complexation modeling of Cu(II adsorption on mixtures of hydrous ferric oxide and kaolinite

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Schaller Melinda S

2008-09-01

Full Text Available Abstract Background The application of surface complexation models (SCMs to natural sediments and soils is hindered by a lack of consistent models and data for large suites of metals and minerals of interest. Furthermore, the surface complexation approach has mostly been developed and tested for single solid systems. Few studies have extended the SCM approach to systems containing multiple solids. Results Cu adsorption was measured on pure hydrous ferric oxide (HFO, pure kaolinite (from two sources and in systems containing mixtures of HFO and kaolinite over a wide range of pH, ionic strength, sorbate/sorbent ratios and, for the mixed solid systems, using a range of kaolinite/HFO ratios. Cu adsorption data measured for the HFO and kaolinite systems was used to derive diffuse layer surface complexation models (DLMs describing Cu adsorption. Cu adsorption on HFO is reasonably well described using a 1-site or 2-site DLM. Adsorption of Cu on kaolinite could be described using a simple 1-site DLM with formation of a monodentate Cu complex on a variable charge surface site. However, for consistency with models derived for weaker sorbing cations, a 2-site DLM with a variable charge and a permanent charge site was also developed. Conclusion Component additivity predictions of speciation in mixed mineral systems based on DLM parameters derived for the pure mineral systems were in good agreement with measured data. Discrepancies between the model predictions and measured data were similar to those observed for the calibrated pure mineral systems. The results suggest that quantifying specific interactions between HFO and kaolinite in speciation models may not be necessary. However, before the component additivity approach can be applied to natural sediments and soils, the effects of aging must be further studied and methods must be developed to estimate reactive surface areas of solid constituents in natural samples.

Electrical Properties of Photodiode Ba0.25Sr0.75TiO3 (BST Thin Film Doped with Ferric Oxide on p-type Si (100 Substrate using Chemical Solution Deposition Method

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Irzaman

2011-12-01

Full Text Available In this paper we have grown pure Ba0.25Sr0.75TiO3 (BST and BST doped by Ferric Oxide Fe2O3 (BFST with doping variations of 5%, 10%, and 15% above type-p Silicon (100 substrate using the chemical solution deposition (CSD method with spin coating technique at rotation speed of 3000 rpm, for 30 seconds. BST thin film are made with a concentration of 1 M 2-methoxyethanol and annealing temperature of 850OC for the Si (100 substrate. Characterization of the thin film is performed for the electrical properties such as the current-voltage (I-V curve using Keithley model 2400 as well as dielectric constant, time constant, pyroelectric characteristics, and depth measurement. The results show that the thin film depth increases if the concentration of the Ferric Oxide doping increases. The I-V characterization shows that the BST and BFST thin film has photodiode properties. The dielectric constant increases with the addition of doping. The maximum dielectric constant value is obtained for 15 % doping concentration namely 83.1 for pure BST and 6.89, 11.1, 41.63 and 83.1, respectively for the Ferric Oxide doping based BST with concentration of 5%, 10%, and 15%. XRD spectra of 15 % of ferric oxide doped BST thin film tetragonal phase, we carried out the lattice constant were a = b = 4.203 Å; c = 4.214 Å; c/a ratio = 1.003

Comparison of ferric chloride and aluminum sulfate on phosphorus removal and membrane fouling in MBR treating BAF effluent of municipal wastewater

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Xin Li

2017-12-01

Full Text Available A membrane bioreactor (MBR was used for treating biological aerated filter effluent in a municipal wastewater plant, and chemical phosphorus removal was accomplished in the MBR. The results showed that ferric chloride of 20 mg/L and aluminum sulfate of 30 mg/L were the optimal dosages for total phosphorus (TP removal, and the TP removal efficiency was over 80%. In long-term continuous operations, both ferric chloride and aluminum sulfate effectively mitigated membrane fouling, with the corresponding growth rate of transmembrane pressure decreased to 0.08 and 0.067 kPa/d, respectively. Sludge particle sizes analysis demonstrated that the decrease of particle sizes lower than 50 μm was the main reason for membrane fouling control. Simultaneously, the proteins and polysaccharide (PS concentrations in the MBR supernatant were analyzed, and the PS concentration significantly decreased to 2.02 mg/L at aluminum sulfate of 30 mg/L, indicating the flocculation of aluminum sulfate on PS was the main reason for mitigation of membrane fouling.

Standard test methods for pitting and crevice corrosion resistance of stainless steels and related alloys by use of ferric Chloride solution

CERN Document Server

American Society for Testing and Materials. Philadelphia

2003-01-01

1.1 These test methods cover procedures for the determination of the resistance of stainless steels and related alloys to pitting and crevice corrosion (see Terminology G 15) when exposed to oxidizing chloride environments. Six procedures are described and identified as Methods A, B, C, D, E, and F. 1.1.1 Method A—Ferric chloride pitting test. 1.1.2 Method B—Ferric chloride crevice test. 1.1.3 Method C—Critical pitting temperature test for nickel-base and chromium-bearing alloys. 1.1.4 Method D—Critical crevice temperature test for nickel-base and chromium-bearing alloys. 1.1.5 Method E—Critical pitting temperature test for stainless steels. 1.1.6 Method F—Critical crevice temperature test for stainless steels. 1.2 Method A is designed to determine the relative pitting resistance of stainless steels and nickel-base, chromium-bearing alloys, whereas Method B can be used for determining both the pitting and crevice corrosion resistance of these alloys. Methods C, D, E and F allow for a rankin...

Safety of intravenous ferric carboxymaltose versus oral iron in patients with nondialysis-dependent CKD

DEFF Research Database (Denmark)

Roger, Simon D; Gaillard, Carlo A; Bock, Andreas H

2017-01-01

-label, multicenter, prospective study of patients with nondialysis-dependent CKD, anemia and iron deficiency randomized (1:1:2) to IV ferric carboxymaltose (FCM), targeting higher (400-600 µg/L) or lower (100-200 µg/L) ferritin, or oral iron. A post hoc analysis of adverse event rates per 100 patient......: These results further support the conclusion that correction of iron deficiency anemia with IV FCM is safe in patients with nondialysis-dependent CKD.......Background: The evidence base regarding the safety of intravenous (IV) iron therapy in patients with chronic kidney disease (CKD) is incomplete and largely based on small studies of relatively short duration. Methods: FIND-CKD (ClinicalTrials.gov number NCT00994318) was a 1-year, open...

Nanospot soldering polystyrene nanoparticles with an optical fiber probe laser irradiating a metallic AFM probe based on the near-field enhancement effect.

Science.gov (United States)

Cui, Jianlei; Yang, Lijun; Wang, Yang; Mei, Xuesong; Wang, Wenjun; Hou, Chaojian

2015-02-04

With the development of nanoscience and nanotechnology for the bottom-up nanofabrication of nanostructures formed from polystyrene nanoparticles, joining technology is an essential step in the manufacturing and assembly of nanodevices and nanostructures in order to provide mechanical integration and connection. To study the nanospot welding of polystyrene nanoparticles, we propose a new nanospot-soldering method using the near-field enhancement effect of a metallic atomic force microscope (AFM) probe tip that is irradiated by an optical fiber probe laser. On the basis of our theoretical analysis of the near-field enhancement effect, we set up an experimental system for nanospot soldering; this approach is carried out by using an optical fiber probe laser to irradiate the AFM probe tip to sinter the nanoparticles, providing a promising technical approach for the application of nanosoldering in nanoscience and nanotechnology.

A study on the alkali leaching of complex compound for molybdenum trioxide and ferric oxide

International Nuclear Information System (INIS)

Kim, C.G.; Whang, Y.K.

1981-01-01

This study is to determine the alkali-leaching meachanism by which complex compound by the reaction made between molybdenite (MoS 2 ) and ferric oxide (Fe 2 O 3 ) in the roasted are when molybdenum trioxide (MoO 3 ) is formed by the roasting reaction of molybdenite concentrate. The results obtained from this experiment are summarized as follows: The heating reaction analysis shows that the complex compound of iron molybdates (Fe 2 O 3 .3-4 MoO 3 ) is formed by the reaction of molybdenum trioxide and ferric oxide at temperatures of above 500 0 C. It is shown that at various reaction temperature below 400 0 C molybdenum trioxide is almost completely leached by caustic soda irrespective of the mole ratio of two chemical samples used for the experiment, whereas at temperature above 400 0 C the leaching rate of molybdenum trioxide decreases except that it varies from 70.77% at a temperature of 900 0 C at which the mole ratio is 1 to 1 to 84.08% at a temperature of 1000 0 C. The x-ray diffraction analysis has shown that the complex compound reacted at a temperature of 1000 0 C produces a complex compound with the crystal structure of iron molybdates, and the alkali-leached residues even with 19.0% of molybdenum trioxide, however, contain only α-Fe 2 O 3 , without showing iron molybdates. The crystalline compound of iron molybdates obtained as a result of heating reaction was leached by using caustic soda, while MoO 3 and Fe 2 O 3 in the leaching residue was found to contain other compounds unable to be leached by caustic soda. (author)

Synthesis of waste cooking oil based biodiesel via ferric-manganese promoted molybdenum oxide / zirconia nanoparticle solid acid catalyst: influence of ferric and manganese dopants.

Science.gov (United States)

Alhassan, Fatah H; Rashid, Umer; Taufiq-Yap, Yun Hin

2015-01-01

The utilization of ferric-manganese promoted molybdenum oxide/zirconia (Fe-Mn- MoO3/ZrO2) (FMMZ) solid acid catalyst for production of biodiesel was demonstrated. FMMZ is produced through impregnation reaction followed by calcination at 600°C for 3 h. The characterization of FMMZ had been done using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), thermal gravimetric analysis (TGA), temperature programmed desorption of NH3 (TPD-NH3), transmission electron microscopy(TEM) and Brunner-Emmett-Teller (BET) surface area measurement. The effect of waste cooking oil methyl esters (WCOME's) yield on the reactions variables such as reaction temperature, catalyst loading, molar ratio of methanol/oil and reusability were also assessed. The catalyst was used to convert the waste cooking oil into corresponding methyl esters (95.6%±0.15) within 5 h at 200℃ reaction temperature, 600 rpm stirring speed, 1:25 molar ratio of oil to alcohol and 4% w/w catalyst loading. The reported catalyst was successfully recycled in six connective experiments without loss in activity. Moreover, the fuel properties of WCOME's were also reported using ASTM D 6751 methods.

Heavy Metals Induce Iron Deficiency Responses at Different Hierarchic and Regulatory Levels.

Science.gov (United States)

Lešková, Alexandra; Giehl, Ricardo F H; Hartmann, Anja; Fargašová, Agáta; von Wirén, Nicolaus

2017-07-01

In plants, the excess of several heavy metals mimics iron (Fe) deficiency-induced chlorosis, indicating a disturbance in Fe homeostasis. To examine the level at which heavy metals interfere with Fe deficiency responses, we carried out an in-depth characterization of Fe-related physiological, regulatory, and morphological responses in Arabidopsis ( Arabidopsis thaliana ) exposed to heavy metals. Enhanced zinc (Zn) uptake closely mimicked Fe deficiency by leading to low chlorophyll but high ferric-chelate reductase activity and coumarin release. These responses were not caused by Zn-inhibited Fe uptake via IRON-REGULATED TRANSPORTER (IRT1). Instead, Zn simulated the transcriptional response of typical Fe-regulated genes, indicating that Zn affects Fe homeostasis at the level of Fe sensing. Excess supplies of cobalt and nickel altered root traits in a different way from Fe deficiency, inducing only transient Fe deficiency responses, which were characterized by a lack of induction of the ethylene pathway. Cadmium showed a rather inconsistent influence on Fe deficiency responses at multiple levels. By contrast, manganese evoked weak Fe deficiency responses in wild-type plants but strongly exacerbated chlorosis in irt1 plants, indicating that manganese antagonized Fe mainly at the level of transport. These results show that the investigated heavy metals modulate Fe deficiency responses at different hierarchic and regulatory levels and that the interaction of metals with physiological and morphological Fe deficiency responses is uncoupled. Thus, this study not only emphasizes the importance of assessing heavy metal toxicities at multiple levels but also provides a new perspective on how Fe deficiency contributes to the toxic action of individual heavy metals. © 2017 American Society of Plant Biologists. All Rights Reserved.

Determination of metallic impurities in raw materials for radioisotope production by atomic absorption spectroscopy

International Nuclear Information System (INIS)

Roca, M.; Alvarez, F.; Capdevila, C.

1969-01-01

Atomic absorption spectrometry has been used for the determination of traces of calcium in scandium oxide, copper in zinc, iron in cobalt oxide, manganese In ferric oxide, nickel in copper and zinc in gallium oxide. The influences on the sensitivities arising from the hollow cathode currents, the gas pressures and the acid concentrations have been considered. A study of the interferences from the metallic matrices has also been performed, the interference due to the absorption of the manganese radiation by the atoms of iron being the most outstanding . In order to remove the interfering elements and increase sensitivity, pre-concentration methods have been tested. The addition methods has also been used. (Author) 14 refs

Radio-frequency capacitance spectroscopy of metallic nanoparticles.

OpenAIRE

Frake, James C.; Kano, Shinya; Ciccarelli, Chiara; Griffiths, Jonathan; Sakamoto, Masanori; Teranishi, Toshiharu; Majima, Yutaka; Smith, Charles G.; Buitelaar, Mark R.

2015-01-01

Recent years have seen great progress in our understanding of the electronic properties of nanomaterials in which at least one dimension measures less than 100 nm. However, contacting true nanometer scale materials such as individual molecules or nanoparticles remains a challenge as even state-of-the-art nanofabrication techniques such as electron-beam lithography have a resolution of a few nm at best. Here we present a fabrication and measurement technique that allows high sensitivity and hi...

Potential side effects of ammonium-ferric-hexacyano-ferrate application: enhanced radiostrontium transfer and free cyanide release

International Nuclear Information System (INIS)

Vandenhove, Hildegarde; Hees, May van; Vandecasteele, Christian

2000-01-01

The effect of the application of ammonium-ferric-hexacyano-ferrate (AFCF), effective in reducing soil-to-plant radiocaesium transfer, on radiostrontium transfer was tested for ryegrass grown under greenhouse conditions on sandy soil for 310 days. Identical radiostrontium transfer factors (9.4 kg kg -1 ) were obtained with 0 or 10 g AFCF m -2 applied. Amending AFCF to planted or uncovered sandy or loamy soils in quantities of up to 100 g AFCF m -2 did not result in detectable levels of free cyanide. Negative side effects of AFCF application to soil are hence unlikely

Design and Analysis of Multilayered Waveguide Structure With Metal-Dielectric Gratings for Sensing With Reflection Narrowband Notch Filter

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Guiju ZHANG

2015-11-01

Full Text Available Developments in micro and nanofabrication technologies have led a variety of grating waveguide structures (GWS being proposed and implemented in optics and laser application systems. A new design of multilayered nanostructure double-grating is described for reflection notch filter. Thin metal film and dielectric film are used and designed with one-dimensional composite gratings. The results calculated by rigorous coupled-wave analysis (RCWA present that the thin metal film between substrate and grating can produce significant attenuated reflections and efficiency in a broad reflected spectral range. The behavior of such a reflection filter is evaluated for refractive index sensing, which can be applied inside the integrated waveguide structure while succeeding cycles in measurement. The filter peaks are designed and obtained in a visible range with full width half maximum (FWHM of several nanometers to less than one nanometer. The multilayered structure shows a sensitivity of refractive index of 220nm/RIU as changing the surroundings. The reflection spectra are studied under different periods, depths and duty cycles. The passive structure and its characteristics can achieve practical applications in various fields, such as optical sensing, color filtering, Raman spectroscopy and laser technology.DOI: http://dx.doi.org/10.5755/j01.ms.21.4.9625

A high-throughput screening strategy for nitrile-hydrolyzing enzymes based on ferric hydroxamate spectrophotometry.

Science.gov (United States)

He, Yu-Cai; Ma, Cui-Luan; Xu, Jian-He; Zhou, Li

2011-02-01

Nitrile-hydrolyzing enzymes (nitrilase or nitrile hydratase/amidase) have been widely used in the pharmaceutical industry for the production of carboxylic acids and their derivatives, and it is important to build a method for screening for nitrile-hydrolyzing enzymes. In this paper, a simple, rapid, and high-throughput screening method based on the ferric hydroxamate spectrophotometry has been proposed. To validate the accuracy of this screening strategy, the nitrilases from Rhodococcus erythropolis CGMCC 1.2362 and Alcaligenes sp. ECU0401 were used for evaluating the method. As a result, the accuracy for assaying aliphatic and aromatic carboxylic acids was as high as the HPLC-based method. Therefore, the method may be potentially used in the selection of microorganisms or engineered proteins with nitrile-hydrolyzing enzymes.

Study of the Efficiency of Arsenic Removal from Drinking Water by Granular Ferric Hydroxide (GFH

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.R. Asgari

2008-04-01

Full Text Available Background and ObjectivePollution of surface and ground water to arsenic (As has been reported from many parts of the world and in some regions of Iran especially in Kurdistan province. Natural pollution of water to As is in fact dependent to geological characteristics of a region. To day, various methods have been recommended for As removal that each of which has special advantages and drawbacks. Granular ferric hydroxide (GFH is a relatively new adsorbent available in market which is principally introduced for As removal.MethodsThis study was an applied survey in which the effects of changing contact time, As concentration, adsorbent weight, pH as well as the effect of sulfate and chloride ions in arsenic removal were determined. Moreover, the model of absorption by GFH was studied and compared with Freundlich and Langmuir models. Raw data were analyzed by Excel and SPSS softwares. ResultsResults showed that As adsorption by GFH imitate both the Freundlich and Langmuir equations (with R2 >0.95. Optimum PH was 7.5 and duration of the process about 30 minutes was sufficient for optimum removal of As. It was also found that efficiency of As removal was high when small amounts of adsorbent were used. Furthermore, sulfate and chloride ions in concentrations used in this study had no noticeable effect on As removal and Fe added during process remains in the water more than the standard value (0.3 mg/l.ConclusionAccording to this study, GFH could be considered as a suitable adsorbent for As removal from polluted water resources because of its high performance without any needs to PH adjustment. However, there are few drawbacks such as Fe addition and relatively high initial cost. Keywords: Arsenic, Granular Ferric Hydroxide (GFH, Adsorption, Drinking Water

Ion sorption onto hydrous ferric oxides: Effect on major element fluid chemistry at Aespoe, Sweden

International Nuclear Information System (INIS)

Bruton, C.J.; Viani, B.E.

1996-06-01

The observed variability of fluid chemistry at the Aespoe Hard Rock Laboratory is not fully described by conservative fluid mixing models. Ion exchange may account for some of the observed discrepancies. It is also possible that variably charged solids such as oxyhydroxides of Fe can serve as sources and sinks of anions and cations through surface complexation. Surface complexation reactions on hydrous ferric oxides involve sorption of both cations and anions. Geochemical modeling of the surface chemistry of hydrous ferric oxides (HFOs) in equilibrium with shallow HBH02 and deep KA0483A waters shows that HFOs can serve as significant, pH-sensitive sources and sinks for cations and anions. Carbonate sorption is favored especially at below-neutral pH. A greater mass of carbonate is sorbed onto HFO surfaces than is contained in the fluid when 10 g goethite, used as a proxy for HFOs, is in contact with 1 kg H 2 O. The masses of sorbent required to significantly impact fluid chemistry through sorption/desorption reactions seem to be reasonable when compared to the occurrences of HFOs at Aespoe. Thus, it is possible that small changes in fluid chemistry can cause significant releases of cations or anions from HFOs into the fluid phase or, alternately, result in uptake of aqueous species onto HFO surfaces. Simulations of the mixing of shallow HBH02 and native KA0483A waters in the presence of a fixed mass of goethite show that surface complexation does not cause the concentrations of Ca, Sr, and SO 4 to deviate from those that are predicted using conservative mixing models. Results for HCO 3 are more difficult to interpret and cannot be addressed adequately at this time

Investigation on reusing water treatment residuals to remedy soil contaminated with multiple metals in Baiyin, China

Energy Technology Data Exchange (ETDEWEB)

Wang, Changhui; Zhao, Yuanyuan [The Key Laboratory of Water and Sediment Sciences, Ministry of Education, School of Environment, Beijing Normal University, Beijing 100875 (China); Pei, Yuansheng, E-mail: yspei@bnu.edu.cn [The Key Laboratory of Water and Sediment Sciences, Ministry of Education, School of Environment, Beijing Normal University, Beijing 100875 (China)

2012-10-30

Highlights: Black-Right-Pointing-Pointer Fe/Al water treatment residuals (FARs) can stabilize As, Pb, Ni, Zn, Cr and Cu. Black-Right-Pointing-Pointer FARs cannot stabilize Ba and Cd. Black-Right-Pointing-Pointer The properties of FARs and soil affect the FARs' ability of stabilizing metals. - Abstract: In this work, the remediation of soils contaminated with multiple metals using ferric and alum water treatment residuals (FARs) in Baiyin, China, was investigated. The results of metals fractionation indicated that after the soil was treated with FARs, arsenic (As), lead (Pb), nickel (Ni), zinc (Zn) and copper (Cu) could be transformed into more stable forms, i.e., As bound in crystalline Fe/Al oxides and other metals in the oxidable and residual forms. However, the forms of chromium (Cr) and cadmium (Cd) were unaffected. Interestingly, due to the effect of FARs, barium (Ba) was predominantly transformed into more mobile forms. The bioaccessibility extraction test demonstrated that the FARs reduced the bioaccessibility of As by 25%, followed by Cu, Cr, Zn, Ni and Pb. The bioaccessibility of Cd and Ba were increased; in particular, there was an increase of 41% for Ba at the end of the test. In conclusion, the FARs can be used to remedy soil contaminated with multiple metals, but comprehensive studies are needed before practical applications of this work.

Supplementation with a dietary multicomponent (Lafergin(®)) based on Ferric Sodium EDTA (Ferrazone(®)): results of an observational study.

Science.gov (United States)

Cignini, Pietro; Mangiafico, Lucia; Padula, Francesco; D'Emidio, Laura; Dugo, Nella; Aloisi, Alessia; Giorlandino, Claudio; Vitale, Salvatore Giovanni

2015-01-01

During pregnancy, iron deficiency anemia is recognized as a specific risk factor for both adverse maternal and perinatal outcome. We decided to test the hypothesis that the daily administration of Lafergin(®), a dietary multicomponent based on Ferrazone(®) (Ferric Sodium EDTA), Lactoferrin, Vitamin C and Vitamin B12, from first trimester of pregnancy until the end of gestation, may significantly reduce, in anemic women, the severity of anemia compared to controls who received ferrous sulfate or liposomal iron.

Comparative Evaluation of U.S. Brand and Generic Intravenous Sodium Ferric Gluconate Complex in Sucrose Injection: In Vitro Cellular Uptake

Directory of Open Access Journals (Sweden)

Min Wu

2017-12-01

Full Text Available Iron deficiency anemia is a common clinical consequence for people who suffer from chronic kidney disease, especially those requiring dialysis. Intravenous (IV iron therapy is a widely accepted safe and efficacious treatment for iron deficiency anemia. Numerous IV iron drugs have been approved by U.S. Food and Drug Administration (FDA, including a single generic product, sodium ferric gluconate complex in sucrose. In this study, we compared the cellular iron uptake profiles of the brand (Ferrlecit® and generic sodium ferric gluconate (SFG products. We used a colorimetric assay to examine the amount of iron uptake by three human macrophage cell lines. This is the first published study to provide a parallel evaluation of the cellular uptake of a brand and a generic IV iron drug in a mononuclear phagocyte system. The results showed no difference in iron uptake across all cell lines, tested doses, and time points. The matching iron uptake profiles of Ferrlecit® and its generic product support the FDA’s present position detailed in the draft guidance on development of SFG complex products that bioequivalence can be based on qualitative (Q1 and quantitative (Q2 formulation sameness, similar physiochemical characterization, and pharmacokinetic bioequivalence studies.

Effect of composition on corrosion resistance of high-alloy austenitic stainless steel weld metals

International Nuclear Information System (INIS)

Marshall, P.I.; Gooch, T.G.

1993-01-01

The corrosion resistance of stainless steel weld metal in the ranges of 17 to 28% chromium (Cr), 6 to 60% nickel (Ni), 0 to 9% molybdenum (Mo), and 0.0 to 0.37% nitrogen (N) was examined. Critical pitting temperatures were determined in ferric chloride (FeCl 3 ). Passive film breakdown potentials were assessed from potentiodynamic scans in 3% sodium chloride (NaCl) at 50 C. Potentiodynamic and potentiostatic tests were carried out in 30% sulfuric acid (H 2 SO 4 ) ar 25 C, which was representative of chloride-free acid media of low redox potential. Metallographic examination and microanalysis were conducted on the test welds. Because of segregation of alloying elements, weld metal pitting resistance always was lower than that of matching composition base steel. The difference increased with higher Cr, Mo, and N contents. Segregation also reduced resistance to general corrosion in H 2 SO 4 , but the effect relative to the base steel was less marked than with chloride pitting. Segregation of Cr, Mo, and N in fully austenitic deposits decreased as the Ni' eq- Cr' eq ratio increased. Over the compositional range studied, weld metal pitting resistance was dependent mainly on Mo content and segregation. N had less effect than in wrought alloys. Both Mo and N enhanced weld metal corrosion resistance in H 2 SO 4

Reactions of Ferrous Coproheme Decarboxylase (HemQ) with O2 and H2O2 Yield Ferric Heme b.

Science.gov (United States)

Streit, Bennett R; Celis, Arianna I; Shisler, Krista; Rodgers, Kenton R; Lukat-Rodgers, Gudrun S; DuBois, Jennifer L

2017-01-10

A recently discovered pathway for the biosynthesis of heme b ends in an unusual reaction catalyzed by coproheme decarboxylase (HemQ), where the Fe(II)-containing coproheme acts as both substrate and cofactor. Because both O 2 and H 2 O 2 are available as cellular oxidants, pathways for the reaction involving either can be proposed. Analysis of reaction kinetics and products showed that, under aerobic conditions, the ferrous coproheme-decarboxylase complex is rapidly and selectively oxidized by O 2 to the ferric state. The subsequent second-order reaction between the ferric complex and H 2 O 2 is slow, pH-dependent, and further decelerated by D 2 O 2 (average kinetic isotope effect of 2.2). The observation of rapid reactivity with peracetic acid suggested the possible involvement of Compound I (ferryl porphyrin cation radical), consistent with coproheme and harderoheme reduction potentials in the range of heme proteins that heterolytically cleave H 2 O 2 . Resonance Raman spectroscopy nonetheless indicated a remarkably weak Fe-His interaction; how the active site structure may support heterolytic H 2 O 2 cleavage is therefore unclear. From a cellular perspective, the use of H 2 O 2 as an oxidant in a catalase-positive organism is intriguing, as is the unusual generation of heme b in the Fe(III) rather than Fe(II) state as the end product of heme synthesis.

Dual fortification of salt with iodine and iron: a randomized, double-blind, controlled trial of micronized ferric pyrophosphate and encapsulated ferrous fumarate in southern India

NARCIS (Netherlands)

Andersson, M.; Thankachan, P.; Muthayya, S.; Goud, R.B.; Kurpad, A.V.; Hurrell, R.F.

2008-01-01

Background:Dual fortification of salt with iodine and iron could be a sustainable approach to combating iodine and iron deficiencies. Objective:We compared the efficacy of dual-fortified salt (DFS) made by using 2 proposed contrasting formulas-one fortifying with iron as micronized ground ferric

Water-soluble organo-building blocks of aminoclay as a soil-flushing agent for heavy metal contaminated soil

International Nuclear Information System (INIS)

Lee, Young-Chul; Kim, Eun Jung; Ko, Dong Ah; Yang, Ji-Won

2011-01-01

Highlights: ► Aminoclays have synthesized using centered metals with aminopropyl silane. ► Developed aminoclay has unique nano-sized and water-soluble properties. ► Aminoclay showed high heavy metal capacity with metal ions and its less toxicity. ► Aminoclay could be used to remediate heavy metals from soils an alternative soil-flushing agent. - Abstract: We demonstrated that water-soluble aminopropyl magnesium functionalized phyllosilicate could be used as a soil-flushing agent for heavy metal contaminated soils. Soil flushing has been an attractive means to remediate heavy metal contamination because it is less disruptive to the soil environment after the treatment was performed. However, development of efficient and non-toxic soil-flushing agents is still required. We have synthesized aminoclays with three different central metal ions such as magnesium, aluminum, and ferric ions and investigated applicability of aminoclays as soil flushing agents. Among them, magnesium (Mg)-centered aminoclay showed the smallest size distribution and superior water solubility, up to 100 mg/mL. Mg aminoclay exhibited cadmium and lead binding capacity of 26.50 and 91.31 mg/g of Mg clay, respectively, at near neutral pH, but it showed negligible binding affinity to metals in acidic conditions. For soil flushing with Mg clay at neutral pH showed cadmium and lead were efficiently extracted from soils by Mg clay, suggesting strong binding ability of Mg clay with cadmium and lead. As the organic matter and clay compositions increased in the soil, the removal efficiency by Mg clay decreased and the operation time increased.

Filamentous hydrous ferric oxide biosignatures in a pipeline carrying acid mine drainage at Iron Mountain Mine, California

Science.gov (United States)

Williams, Amy J.; Alpers, Charles N.; Sumner, Dawn Y.; Campbell, Kate M.

2017-01-01

A pipeline carrying acidic mine effluent at Iron Mountain, CA, developed Fe(III)-rich precipitate caused by oxidation of Fe(II)aq. The native microbial community in the pipe included filamentous microbes. The pipe scale consisted of microbial filaments, and schwertmannite (ferric oxyhydroxysulfate, FOHS) mineral spheres and filaments. FOHS filaments contained central lumina with diameters similar to those of microbial filaments. FOHS filament geometry, the geochemical environment, and the presence of filamentous microbes suggest that FOHS filaments are mineralized microbial filaments. This formation of textural biosignatures provides the basis for a conceptual model for the development and preservation of biosignatures in other environments.

Heavy Metals Induce Iron Deficiency Responses at Different Hierarchic and Regulatory Levels1[OPEN

Science.gov (United States)

2017-01-01

In plants, the excess of several heavy metals mimics iron (Fe) deficiency-induced chlorosis, indicating a disturbance in Fe homeostasis. To examine the level at which heavy metals interfere with Fe deficiency responses, we carried out an in-depth characterization of Fe-related physiological, regulatory, and morphological responses in Arabidopsis (Arabidopsis thaliana) exposed to heavy metals. Enhanced zinc (Zn) uptake closely mimicked Fe deficiency by leading to low chlorophyll but high ferric-chelate reductase activity and coumarin release. These responses were not caused by Zn-inhibited Fe uptake via IRON-REGULATED TRANSPORTER (IRT1). Instead, Zn simulated the transcriptional response of typical Fe-regulated genes, indicating that Zn affects Fe homeostasis at the level of Fe sensing. Excess supplies of cobalt and nickel altered root traits in a different way from Fe deficiency, inducing only transient Fe deficiency responses, which were characterized by a lack of induction of the ethylene pathway. Cadmium showed a rather inconsistent influence on Fe deficiency responses at multiple levels. By contrast, manganese evoked weak Fe deficiency responses in wild-type plants but strongly exacerbated chlorosis in irt1 plants, indicating that manganese antagonized Fe mainly at the level of transport. These results show that the investigated heavy metals modulate Fe deficiency responses at different hierarchic and regulatory levels and that the interaction of metals with physiological and morphological Fe deficiency responses is uncoupled. Thus, this study not only emphasizes the importance of assessing heavy metal toxicities at multiple levels but also provides a new perspective on how Fe deficiency contributes to the toxic action of individual heavy metals. PMID:28500270

Possible Association of Ferrous Phosphates and Ferric Sulfates in S-rich Soil on Mars

Science.gov (United States)

Mao, J.; Schroeder, C.; Haderlein, S.

2012-12-01

NASA Mars Exploration Rover (MER) Spirit explored Gusev Crater to look for signs of ancient aqueous activity, assess past environmental conditions and suitability for life. Spirit excavated light-toned, S-rich soils at several locations. These are likely of hydrothermal, possibly fumarolic origin. At a location dubbed Paso Robles the light-toned soil was also rich in P - a signature from surrounding rock. While S is mainly bound in ferric hydrated sulfates [1], the mineralogy of P is ill-constrained [2]. P is a key element for life and its mineralogy constrains its availability. Ferrous phases observed in Paso Robles Mössbauer spectra may represent olivine and pyroxene from surrounding basaltic soil [1] or ferrous phosphate minerals [3]. Phosphate is well-known to complex and stabilize Fe 2+ against oxidation to Fe 3+ . Schröder et al. [3] proposed a formation pathway of ferrous phosphate/ferric sulfate associations: sulfuric acid reacts with basalt containing apatite, forming CaSO4 and phosphoric acid. The phosphoric and/or excess sulfuric acid reacts with olivine, forming Fe2+-phosphate and sulfate. The phosphate is less soluble and precipitates. Ferrous sulfate remains in solution and is oxidized as pH increases. To verify this pathway, we dissolved Fe2+-chloride and Na-phosphate salts in sulfuric acid inside an anoxic glovebox. The solution was titrated to pH 6 by adding NaOH when a first precipitate formed, which was ferrous phosphate according to Mössbauer spectroscopy (MB). At that point the solution was removed from the glovebox and allowed to evaporate in the presence of atmospheric oxygen, leading to the oxidation of Fe2+. The evaporation rate was controlled by keeping the suspensions at different temperatures; pH was monitored during the evaporation process. The final precipitates were analyzed by MB and X-Ray Fluorescence (XRF), comparable to MER MB and Alpha Particle X-ray Spectrometer instrument datasets, and complementary techniques such as X

The Effect of Pressure on Iron Speciation in Silicate Melts at a Fixed Oxygen Fugacity: The Possibility of a Redox Profile Through a Terrestrial Magma Ocean

Science.gov (United States)

Armstrong, K.; Frost, D. J.; McCammon, C. A.; Rubie, D. C.; Boffa Ballaran, T.

2017-12-01

As terrestrial planets accreted, mantle silicates equilibrated with core-forming metallic iron, which would have imposed a mantle oxygen fugacity below the iron-wüstite oxygen buffer. Throughout Earth's history, however, the oxygen fugacity of at least the accessible portions of the upper mantle has been 4-5 orders of magnitude higher. The process that caused the rapid increase in the redox state of the mantle soon after core formation is unclear. Here we test the possibility that pressure stabilises ferric iron in silicate melts, as has been observed in silicate minerals. A deep magma ocean, which would have likely existed towards the end of accretion, could then develop a gradient in oxygen fugacity for a fixed ferric-ferrous ratio as a result of pressure. We have equilibrated an andesitic melt with a Ru-RuO2 buffer in a multianvil press between 5 and 24 GPa. Further experiments were performed on the same melt in equilibrium with iron metal. The recovered melts were then analysed using Mössbauer spectroscopy to determine the ferric/ferrous ratio. The results show that for the Ru-RuO2 buffer at lower pressures, the ferric iron content decreases with pressure, due to a positive volume change of the reaction FeO + 1/4O2 = FeO1.5. Ferric iron content also appears to be sensitive to water content at lower pressures. However, above 15 GPa this trend apparently reverses and the ferric iron content increases with pressure. This reversal in pressure dependence would drive the oxygen fugacity of a deep magma ocean with a fixed ferric/ferrous ratio down with increasing depth. This would create a redox gradient, where the magma ocean could potentially be in equilibrium with metallic iron at its base but more oxidised in its shallower regions. Crystallisation of this magma ocean could render an upper mantle oxygen fugacity similar to that in the Earth's accessible mantle today.

Enhanced dark hydrogen fermentation by addition of ferric oxide nanoparticles using Enterobacter aerogenes.

Science.gov (United States)

Lin, Richen; Cheng, Jun; Ding, Lingkan; Song, Wenlu; Liu, Min; Zhou, Junhu; Cen, Kefa

2016-05-01

Ferric oxide nanoparticles (FONPs) were used to facilitate dark hydrogen fermentation using Enterobacter aerogenes. The hydrogen yield of glucose increased from 164.5±2.29 to 192.4±1.14mL/g when FONPs concentration increased from 0 to 200mg/L. SEM images of E. aerogenes demonstrated the existence of bacterial nanowire among cells, suggesting FONPs served as electron conduits to enhance electron transfer. TEM showed cellular internalization of FONPs, indicating hydrogenase synthesis and activity was potentially promoted due to the released iron element. When further increasing FONPs concentration to 400mg/L, the hydrogen yield of glucose decreased to 147.2±2.54mL/g. Soluble metabolic products revealed FONPs enhanced acetate pathway of hydrogen production, but weakened ethanol pathway. This shift of metabolic pathways allowed more nicotinamide adenine dinucleotide for reducing proton to hydrogen. Copyright © 2016 Elsevier Ltd. All rights reserved.

Reactive solute transport in streams: A surface complexation approach for trace metal sorption

Science.gov (United States)

Runkel, Robert L.; Kimball, Briant A.; McKnight, Diane M.; Bencala, Kenneth E.

1999-01-01

A model for trace metals that considers in-stream transport, metal oxide precipitation-dissolution, and pH-dependent sorption is presented. Linkage between a surface complexation submodel and the stream transport equations provides a framework for modeling sorption onto static and/or dynamic surfaces. A static surface (e.g., an iron- oxide-coated streambed) is defined as a surface with a temporally constant solid concentration. Limited contact between solutes in the water column and the static surface is considered using a pseudokinetic approach. A dynamic surface (e.g., freshly precipitated metal oxides) has a temporally variable solid concentration and is in equilibrium with the water column. Transport and deposition of solute mass sorbed to the dynamic surface is represented in the stream transport equations that include precipitate settling. The model is applied to a pH-modification experiment in an acid mine drainage stream. Dissolved copper concentrations were depressed for a 3 hour period in response to the experimentally elevated pH. After passage of the pH front, copper was desorbed, and dissolved concentrations returned to ambient levels. Copper sorption is modeled by considering sorption to aged hydrous ferric oxide (HFO) on the streambed (static surface) and freshly precipitated HFO in the water column (dynamic surface). Comparison of parameter estimates with reported values suggests that naturally formed iron oxides may be more effective in removing trace metals than synthetic oxides used in laboratory studies. The model's ability to simulate pH, metal oxide precipitation-dissolution, and pH-dependent sorption provides a means of evaluating the complex interactions between trace metal chemistry and hydrologic transport at the field scale.

Radical-Scavenging Activity and Ferric Reducing Ability of Juniperus thurifera (L.), J. oxycedrus (L.), J. phoenicea (L.) and Tetraclinis articulata (L.)

OpenAIRE

El Jemli, Meryem; Kamal, Rabie; Marmouzi, Ilias; Zerrouki, Asmae; Cherrah, Yahia; Alaoui, Katim

2016-01-01

Objective. The aim of this work is to study and compare the antioxidant properties and phenolic contents of aqueous leaf extracts of Juniperus thurifera, Juniperus oxycedrus, Juniperus Phoenicea, and Tetraclinis articulata from Morocco. Methods. Antioxidant activities of the extracts were evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical-scavenging ability, Trolox equivalent antioxidant capacity (TEAC), and ferric reducing antioxidant power (FRAP) assays. Also the total phenolic ...

Coagulant effect of ferric chloride for separation of biomass from the microalgae Chlorella sp. of the water; Efeito coagulante do cloreto ferrico para separacao da biomassa da microalga Chlorella sp. da agua

Energy Technology Data Exchange (ETDEWEB)

Souza, Tamara Daiane de; Mendes, Mucio Andre dos Santos Alves [Universidade Federal de Vicosa (UFV), MG (Brazil). Dept. de Engenharia Agricola e Ambiental], E-mail: tamara_daiane@yahoo.com.br; Matos, Antonio Teixeira de [Universidade Federal de Vicosa (UFV), MG (Brazil). Dept. de Engenharia Agricola; Lo Monaco, Paola Alfonsa Vieira [Instituto Federal do Espirito Santo (IFES), Santa Teresa, ES (Brazil); Universidade Federal de Vicosa (DEA/UFV), MG (Brazil). Dept. de Engenharia Agricola

2010-07-01

Currently, much interest has been focused on the biotechnological potential of microalgae, mainly in the production of biofuels. For this to become viable the biomass of algae should be separated from the water and the process of coagulation/flocculation/sedimentation may be an alternative. This study aimed to evaluate the effect of ferric chloride as coagulant agent of the microalgae Chlorella vulgaris. Were tested five concentrations of ferric chloride in the suspension containing the microalgae: 20,0; 30,0; 40,0; 50,0 e 100,0 g L{sup -1}. The tests were performed using the Jar-test apparatus and the turbidity was measured in suspensions after 2 hours of sedimentation. Mathematical equations were adjusted by regression, relating the concentration used in the tests according to the turbidity of the suspension. There was a linear decrease in turbidity with the addition of ferric chloride, and for concentration of 100.0 g L{sup -1} was achieved a removal efficiency of turbidity of 58%. However, it is necessary to conduct further research, evaluating the economic feasibility of the technique in the separation of microalgae from the water. (author)

Biogeochemical reactive-diffusive transport of heavy metals in Lake Coeur d'Alene sediments

International Nuclear Information System (INIS)

Sevinc Sengoer, S.; Spycher, Nicolas F.; Ginn, Timothy R.; Sani, Rajesh K.; Peyton, Brent

2007-01-01

Decades of runoff from precious-metal mining operations in the Lake Coeur d'Alene Basin, Idaho, have left the sediments in this lake heavily enriched with toxic metals, most notably Zn, Pb and Cu, together with As. The bioavailability, fate and transport of these metals in the sediments are governed by complex biogeochemical processes. In particular, indigenous microbes are capable of catalyzing reactions that detoxify their environments, and thus constitute an important driving component in the biogeochemical cycling of these metals. Here, the development of a quantitative model to evaluate the transport and fate of Zn, Pb and Cu in Lake Coeur d'Alene sediments is reported. The current focus is on the investigation and understanding of local-scale processes, rather than the larger-scale dynamics of sedimentation and diagenesis, with particular emphasis on metal transport through reductive dissolution of Fe hydroxides. The model includes 1-D inorganic diffusive transport coupled to a biotic reaction network including consortium biodegradation kinetics with multiple terminal electron acceptors and syntrophic consortium biotransformation dynamics of redox front. The model captures the mobilization of metals initially sorbed onto hydrous ferric oxides, through bacterial reduction of Fe(III) near the top of the sediment column, coupled with the precipitation of metal sulfides at depth due to biogenic sulfide production. Key chemical reactions involve the dissolution of ferrihydrite and precipitation of siderite and Fe sulfide. The relative rates of these reactions play an important role in the evolution of the sediment pore-water chemistry, notably pH, and directly depend on the relative activity of Fe and SO 4 reducers. The model captures fairly well the observed trends of increased alkalinity, sulfide, Fe and heavy metal concentrations below the sediment-water interface, together with decreasing terminal electron acceptor concentrations with depth, including the

Porphyria Cutanea Tarda in a Patient with End-Stage Renal Disease: A Case of Successful Treatment with Deferoxamine and Ferric Carboxymaltose

Directory of Open Access Journals (Sweden)

Natacha Rodrigues

2017-01-01

Full Text Available Porphyria cutanea tarda (PCT is a rare disease, with a strong association with hepatitis C virus. PCT is particularly problematic in end-stage renal disease patients as they have no renal excretion of porphyrins and these are poorly dialyzed. Also, conventional treatment of PCT is compromised in these patients as hydroxychloroquine is contraindicated, phlebotomies with the stipulated frequency are poorly tolerated in already anaemia-prone patients, and iron-chelating agents are less efficient in removing iron and contribute to worsening anaemia. The authors report a patient on haemodialysis, with hepatitis C infection, that is diagnosed with PCT. Despite the good clinical results with deferoxamine, she became dependent on blood transfusions because of her ferropenic state. Every time oxide iron was started, the patient developed clinical features of the disease, resolving after the suspension of the drug. A decision was made to start the patient on ferric carboxymaltose, which was well tolerated without disease symptoms and need of further blood transfusions. This case suggests that deferoxamine is efficient in treatment of porphyria cutanea tarda. Also, ferric carboxymaltose may be a valuable option for refractory anaemia in patients with this disease and end-stage renal disease, as it seems to provide iron without clinical relapse of the disease.

Preparation of polymeric aluminium ferric chloride from bauxite tailings

Directory of Open Access Journals (Sweden)

Ma D.

2013-01-01

Full Text Available Bauxite tailings are the main solid wastes in the ore dressing process. The Al2O3 and Fe2O3 contents in bauxite tailings can reach 50% and 13% respectively. The present study proposed a feasible method to use bauxite tailings to prepare polymeric aluminium ferric chloride (PAFC, a new composite inorganic polymer for water purification. Bauxite tailings roasted reacting with hydrochloric acid under air, pickle liquor which mainly contains Fe3+, Al3+ was generated, then calcium aluminate was used to adjust pH value and the basicity of the pickle liquor, the PAFC was subsequently prepared after the polymerization process. The optimal synthesizing parameters for the preparation of PAFC obtained were as follows: the concentration of hydrochloric acid of 24 wt%, ratio of hydrochloric acid to bauxite tailings of 6:1, temperature of 90ºC, leaching time of 2.5 hours, ration of pickle liquor to calcium aluminate of 12:1, polymerization temperature of 90ºC and polymerization time of about 3 hours. The basicity of PAFC was higher than 68%, the sum concentration of Al2O3 and Fe2O3 was beyond 12.5%. The results of flocculation tests indicate that the PAFC has a better performance of removing the turbidity of wastewater compared to PAC, and PAFC prepared by bauxite tailings is a kind of high quality flocculants.

Development of a focused ion beam micromachining system

Energy Technology Data Exchange (ETDEWEB)

Pellerin, J.G.; Griffis, D.; Russell, P.E.

1988-12-01

Focused ion beams are currently being investigated for many submicron fabrication and analytical purposes. An FIB micromachining system consisting of a UHV vacuum system, a liquid metal ion gun, and a control and data acquisition computer has been constructed. This system is being used to develop nanofabrication and nanomachining techniques involving focused ion beams and scanning tunneling microscopes.

Physico-chemical properties of the new generation IV iron preparations ferumoxytol, iron isomaltoside 1000 and ferric carboxymaltose.

Science.gov (United States)

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.

Design, fabrication and cold tests of a super ferric octupole corrector for the LHC

International Nuclear Information System (INIS)

Garcia-Tabares, L.; Calero, J.; Laurent, G.; Russenschuck, S.; Siegel, N.; Traveria, M.; Aguirre, P.; Etxeandia, J.; Garcia, J.

1996-01-01

In the corrections scheme of the LHC it is planed to install octupole corrector magnets in the short straight section of the lattice. Initially these correctors were distributed windings on the cold bore tube nested in the tuning quadrupoles. The latter being suppressed a new compact super ferric design was chosen for the octupole prototype, suitable for a two-in-one configuration. This prototype was designed by CERN and CEDEX/Spain, built at INDAR/Spain and tested at CEDEX. The paper reports on the design of the prototype, describes the fabrication and assembly and presents the measurement results. Special interest has been taken to design a simple and compact magnet, easy to fabricate and training free below nominal field. First results show the feasibility of the solution wich will be finally confirmed by magnetic measurement. (Author) 4 refs

Renal function in patients with non-dialysis chronic kidney disease receiving intravenous ferric carboxymaltose

DEFF Research Database (Denmark)

Macdougall, Iain C; Bock, Andreas H; Carrera, Fernando

2017-01-01

BACKGROUND: Preclinical studies demonstrate renal proximal tubular injury after administration of some intravenous iron preparations but clinical data on renal effects of intravenous iron are sparse. METHODS: FIND-CKD was a 56-week, randomized, open-label, multicenter study in which patients...... with non-dialysis dependent chronic kidney disease (ND-CKD), anemia and iron deficiency without erythropoiesis-stimulating agent therapy received intravenous ferric carboxymaltose (FCM), targeting either higher (400-600 μg/L) or lower (100-200 μg/L) ferritin values, or oral iron. RESULTS: Mean (SD) e...... quartiles of FCM dose, change in ferritin or change in TSAT versus change in eGFR. Dialysis initiation was similar between groups. Renal adverse events were rare, with no indication of between-group differences. CONCLUSION: Intravenous FCM at doses that maintained ferritin levels of 100-200 μg/L or 400...

Induction of hepatic and renal metallothionein synthesis by ferric nitrilotriacetate in mice: the role of MT as an antioxidant

International Nuclear Information System (INIS)

Min, Kyong-Son; Morishita, Fumio; Tetsuchikawahara, Noriko; Onosaka, Satomi

2005-01-01

Metallothionein (MT) demonstrates strong antioxidant properties, yet the physiological relevance of its antioxidant action is not clear. Injection of mice with ferric nitrilotriacetate (Fe-NTA) caused a dose-dependent increase in hepatic and renal MT. Fe-NTA caused a greater increase in hepatic and renal MT concentration (2.5- and 4-fold) compared with FeCl 3 at the same dose of ferric ion. MT mRNA levels were markedly elevated in both of tissues. Thiobarbituric acid (TBA) values in both tissues reached a maximum after 2-4 h. The MT concentrations were significantly increased after 2-4 h in liver and after 8-16 h in kidneys. Plasma concentrations of cytokines such as IL-6 and TNFα were elevated by 4 h; IL-6 levels were 24 times higher after Fe-NTA than that after injection of FeCl 3 . Pretreatment of mice with ZnSO 4 attenuated nephrotoxicity induced by Fe-NTA after 2 h, but was not effective 4 h after injection. After a Fe-NTA injection, a loss of Cd-binding properties of preinduced MT was observed only in kidneys of Zn-pretreated mice but not in liver. Treatment with BSO, glutathione (GSH) depletor, intensified a loss of its Cd-binding properties after a Fe-NTA injection. These results indicate that induction of MT synthesis may result from reactive oxygen species (ROS) generated by Fe-NTA, and MT may act in vivo as a complementary antioxidant

A radioisotope study of the dispersion of ferric hydroxide floc in Bass Strait

International Nuclear Information System (INIS)

Davison, A.

1983-01-01

The dispersion of ferric hydroxide floc in Bass Strait waters adjacent to Burnie, Tasmania, has been investigated using radioisotope tracer techniques. Gold-198 labelled floc was employed to follow the movement of floc produced by dilution of the iron-rich effluent from a titanium dioxide plant. Dispersion was determined under calm and storm conditions. Tidal and wind-driven currents were measured, oscillating wave generated currents were calculated, and lateral and vertical dispersion coefficients were determined. It is concluded that floc disperses episodically during storms. The agglomerated floc remains trapped in a stable seabed layer which spreads slowly at seabed level when wind velocities are less than 15 m s -1 . When wind velocities exceed this level, the wave generated oscillating currents at seabed level, 30 m below the surface, are strong enough to raise the floc into suspension where advective dispersion occurs. Since tidal currents in the area are negligible, the direction of floc movement depends on the direction of the wind-driven current during each storm

Precise coulometric titration of uranium in a high-purity uranium metal and in uranium compounds

International Nuclear Information System (INIS)

Tanaka, Tatsuhiko; Yoshimori, Takayoshi

1975-01-01

Uranium in uranyl nitrate, uranium trioxide and a high-purity uranium metal was assayed by the coulometric titration with biamperometric end-point detection. Uranium (VI) was reduced to uranium (IV) by solid bismuth amalgam in 5M sulfuric acid solution. The reduced uranium was reoxidized to uranium (VI) with a large excess of ferric ion at a room temperature, and the ferrous ion produced was titrated with the electrogenerated manganese(III) fluoride. In the analyses of uranium nitrate and uranium trioxide, the results were precise enough when the error from uncertainty in water content in the samples was considered. The standard sample of pure uranium metal (JAERI-U4) was assayed by the proposed method. The sample was cut into small chips of about 0.2g. Oxides on the metal surface were removed by the procedure shown by National Bureau of Standards just before weighing. The mean assay value of eleven determinations corrected for 3ppm of iron was (99.998+-0.012) % (the 95% confidence interval for the mean), with a standard deviation of 0.018%. The proposed coulometric method is simple and permits accurate and precise determination of uranium which is matrix constituent in a sample. (auth.)

Water-soluble organo-building blocks of aminoclay as a soil-flushing agent for heavy metal contaminated soil

Energy Technology Data Exchange (ETDEWEB)

Lee, Young-Chul [Department of Chemical and Biomolecular Engineering (BK21 program), KAIST, 335 Gwahak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Kim, Eun Jung [Advanced Biomass R and D Center, KAIST, 291 Daehakno, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Ko, Dong Ah [Department of Chemical and Biomolecular Engineering (BK21 program), KAIST, 335 Gwahak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Yang, Ji-Won, E-mail: jiwonyang@kaist.ac.kr [Department of Chemical and Biomolecular Engineering (BK21 program), KAIST, 335 Gwahak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Advanced Biomass R and D Center, KAIST, 291 Daehakno, Yuseong-gu, Daejeon 305-701 (Korea, Republic of)

2011-11-30

Highlights: Black-Right-Pointing-Pointer Aminoclays have synthesized using centered metals with aminopropyl silane. Black-Right-Pointing-Pointer Developed aminoclay has unique nano-sized and water-soluble properties. Black-Right-Pointing-Pointer Aminoclay showed high heavy metal capacity with metal ions and its less toxicity. Black-Right-Pointing-Pointer Aminoclay could be used to remediate heavy metals from soils an alternative soil-flushing agent. - Abstract: We demonstrated that water-soluble aminopropyl magnesium functionalized phyllosilicate could be used as a soil-flushing agent for heavy metal contaminated soils. Soil flushing has been an attractive means to remediate heavy metal contamination because it is less disruptive to the soil environment after the treatment was performed. However, development of efficient and non-toxic soil-flushing agents is still required. We have synthesized aminoclays with three different central metal ions such as magnesium, aluminum, and ferric ions and investigated applicability of aminoclays as soil flushing agents. Among them, magnesium (Mg)-centered aminoclay showed the smallest size distribution and superior water solubility, up to 100 mg/mL. Mg aminoclay exhibited cadmium and lead binding capacity of 26.50 and 91.31 mg/g of Mg clay, respectively, at near neutral pH, but it showed negligible binding affinity to metals in acidic conditions. For soil flushing with Mg clay at neutral pH showed cadmium and lead were efficiently extracted from soils by Mg clay, suggesting strong binding ability of Mg clay with cadmium and lead. As the organic matter and clay compositions increased in the soil, the removal efficiency by Mg clay decreased and the operation time increased.

Glutathione-dependent extracellular ferric reductase activities in dimorphic zoopathogenic fungi

Science.gov (United States)

Zarnowski, Robert; Woods, Jon P.

2009-01-01

In this study, extracellular glutathione-dependent ferric reductase (GSH-FeR) activities in different dimorphic zoopathogenic fungal species were characterized. Supernatants from Blastomyces dermatitidis, Histoplasma capsulatum, Paracoccidioides brasiliensis and Sporothrix schenckii strains grown in their yeast form were able to reduce iron enzymically with glutathione as a cofactor. Some variations in the level of reduction were noted amongst the strains. This activity was stable in acidic, neutral and slightly alkaline environments and was inhibited when trivalent aluminium and gallium ions were present. Using zymography, single bands of GSH-FeRs with apparent molecular masses varying from 430 to 460 kDa were identified in all strains. The same molecular mass range was determined by size exclusion chromatography. These data demonstrate that dimorphic zoopathogenic fungi produce and secrete a family of similar GSH-FeRs that may be involved in the acquisition and utilization of iron. Siderophore production by these and other fungi has sometimes been considered to provide a full explanation of iron acquisition in these organisms. Our work reveals an additional common mechanism that may be biologically and pathogenically important. Furthermore, while some characteristics of these enzymes such as extracellular location, cofactor utilization and large size are not individually unique, when considered together and shared across a range of fungi, they represent an important novel physiological feature. PMID:16000713

Removal of the blue 1 dye of aqueous solutions using ferric zeolite

International Nuclear Information System (INIS)

Pinedo H, S. Y.

2010-01-01

Water is essential to all life forms, including humans. In recent years water use has increased substantially, also has been altered in its capacity as a result of various human activities, such as domestic, industrial and agricultural, also by natural activity. Undoubtedly one of the main pollutants today are the waste generated by the food industry, due to the use of dyes for the production of their products. So it is necessary to restore water quality through treatment systems to remove contaminants, and thus prevent disease and imbalance of ecosystems. Due to the above, it is important to conduct research directed towards finding new ways to remove dyes such as blue 1 used in the food industry, using low cost materials and abundant in nature as zeolites. To accomplish the above, the present study has the purpose to evaluate the adsorption capacity of the blue dye 1 in aqueous solutions. To accomplish that objective, the zeolite material was reconditioned to improve its sorption properties of the material and provide the ability to adsorb pollutants such as this dye. The zeolite material was characterized by scanning electron microscopy and elemental analysis, X-ray diffraction and infrared spectroscopy. To evaluate the ability of blue 1 dye sorption the kinetics and sorption isotherms were determined; the experimental results were adjusted to mathematical models such as pseudo-first order, pseudo second order and Elovich to describe the kinetic process, and the Langmuir, Freundlich and Langmuir-Freundlich to describe sorption isotherms. The results showed that ferric zeolite surface is a heterogeneous material and has a considerable adsorption capacity, which makes it a potential adsorbent for removing color from aqueous streams. Also the sorption of the dye was evaluated at different ph values; the most sorption was carried out at ph values 1, 3 and 11. We also evaluated the change in mass where the sorption capacities for the blue 1 increase by increasing

Metal-Anion Pairing at Oxide/Water Interfaces: Theoretical and Experimental Investigations from the Nanoscale to the Macroscale

Energy Technology Data Exchange (ETDEWEB)

Allen, Heather [The Ohio State Univ., Columbus, OH (United States)

2016-11-14

We combine the use of several techniques including bulk adsorption experiments, X-ray absorption, infrared, total internal reflection Raman, and vibrational sum frequencygeneration (XAS, IR, TIR-Raman, VSFG) spectroscopies, and molecular modeling to investigate ion adsorption at mineral surfaces. XAS and TIR-Raman provides data on how the metal binds to the surface (e.g., monodentate, bidentate), IR provides data on bulk anion adsorption at mineral surfaces from aqueous solutions, and VSFG provides surface specific data on anion adsorption at the mineral surface as well as impact of adsorbed metal-anion pairs on water structure at the mineral surface. Molecular modeling is used to guide spectroscopic data interpretation by providing information on water structure around ions in solution and the structure of metal-anion complexes in aqueous solutions. In addition, molecular modeling is used to provide insight into water structure at mineral surfaces, the surface sites involved in ion adsorption, and the distribution of ion pairs between aqueous solution and the mineral surface. Our studies have focused on systems involving alkaline earth metal (Mg2+, Ca2+, Sr2+, Ba2+) and heavy metal (Co2+, Cd2+) cations. The anions we have selected for studyinclude Cl-, NO3-, ClO4-, SO42-, SeO32-, and SeO42-. Ion adsorption and the potential formation ofternary complexes on silica (quartz, amorphous silica), alumina (corundum and gibbsite), and ferric iron oxides (goethite and hematite) are under investigation.

Femtosecond excitations in metallic nanostructures. From ultrafast light confinement to a local electron source

Energy Technology Data Exchange (ETDEWEB)

Ropers, C.

2007-07-11

This thesis contributes to the understanding of optical excitations in metallic nanostructures. In experiments on selected model structures, the dynamics of these excitations and their electromagnetic spatial modes are investigated with femtosecond temporal and nanometer spatial resolution, respectively. Angle- and time-resolved transmission experiments on metallic thin film gratings demonstrate the dominant role resonant surface plasmon polaritons (SPPs) play in the optical properties of such structures. The lifetimes of these excitations are determined, and it is shown that coherent couplings among SPP-resonances result in drastic lifetime modifications. Near the visible part of the spectrum, subradiant SPP lifetimes of up to 200 femtoseconds are observed, which is considerably longer than previously expected for these structures. The spatial SPP mode profiles are imaged using a custom-built near-field optical microscope. The experiments reveal a direct correlation between the spatial mode structure and the dynamics of different SPP resonances. Coupling-induced SPP band gaps are identified as splittings into symmetric and antisymmetric surface modes. These findings allow for an interpretation of the near-field optical image contrast in terms of the contributions of different vectorial components of the electromagnetic near-field. A selective imaging of different electric and magnetic field components is demonstrated for various types of near-field probes. Furthermore, the excitation of SPPs in periodic structures is employed in a novel type of near-field tip. The resonant excitation of SPPs in a nanofabricated grating on the shaft of a sharp metallic tip results in their concentration at the tip apex. The final part of the thesis highlights the importance of optical field enhancements for the local generation of nonlinear optical signals at the apex of sharp metallic tips. Specifically, the observation of intense multiphoton electron emission after femtosecond

Groundwater arsenic removal by coagulation using ferric(III) sulfate and polyferric sulfate: A comparative and mechanistic study.

Science.gov (United States)

Cui, Jinli; Jing, Chuanyong; Che, Dongsheng; Zhang, Jianfeng; Duan, Shuxuan

2015-06-01

Elevated arsenic (As) in groundwater poses a great threat to human health. Coagulation using mono- and poly-Fe salts is becoming one of the most cost-effective processes for groundwater As removal. However, a limitation comes from insufficient understanding of the As removal mechanism from groundwater matrices in the coagulation process, which is critical for groundwater treatment and residual solid disposal. Here, we overcame this hurdle by utilizing microscopic techniques to explore molecular As surface complexes on the freshly formed Fe flocs and compared ferric(III) sulfate (FS) and polyferric sulfate (PFS) performance, and finally provided a practical solution in As-geogenic areas. FS and PFS exhibited a similar As removal efficiency in coagulation and coagulation/filtration in a two-bucket system using 5mg/L Ca(ClO)2. By using the two-bucket system combining coagulation and sand filtration, 500 L of As-safe water (<10 μg/L) was achieved during five treatment cycles by washing the sand layer after each cycle. Fe k-edge X-ray absorption near-edge structure (XANES) and As k-edge extended X-ray absorption fine structure (EXAFS) analysis of the solid residue indicated that As formed a bidentate binuclear complex on ferrihydrite, with no observation of scorodite or poorly-crystalline ferric arsenate. Such a stable surface complex is beneficial for As immobilization in the solid residue, as confirmed by the achievement of much lower leachate As (0.9 μg/L-0.487 mg/L) than the US EPA regulatory limit (5 mg/L). Finally, PFS is superior to FS because of its lower dose, much lower solid residue, and lower cost for As-safe drinking water. Copyright © 2015. Published by Elsevier B.V.

Demonstration of the efficiency and robustness of an acid leaching process to remove metals from various CCA-treated wood samples.

Science.gov (United States)

Coudert, Lucie; Blais, Jean-François; Mercier, Guy; Cooper, Paul; Janin, Amélie; Gastonguay, Louis

2014-01-01

In recent years, an efficient and economically attractive leaching process has been developed to remove metals from copper-based treated wood wastes. This study explored the applicability of this leaching process using chromated copper arsenate (CCA) treated wood samples with different initial metal loading and elapsed time between wood preservation treatment and remediation. The sulfuric acid leaching process resulted in the solubilization of more than 87% of the As, 70% of the Cr, and 76% of the Cu from CCA-chips and in the solubilization of more than 96% of the As, 78% of the Cr and 91% of the Cu from CCA-sawdust. The results showed that the performance of this leaching process might be influenced by the initial metal loading of the treated wood wastes and the elapsed time between preservation treatment and remediation. The effluents generated during the leaching steps were treated by precipitation-coagulation to satisfy the regulations for effluent discharge in municipal sewers. Precipitation using ferric chloride and sodium hydroxide was highly efficient, removing more than 99% of the As, Cr, and Cu. It appears that this leaching process can be successfully applied to remove metals from different CCA-treated wood samples and then from the effluents. Copyright © 2013 Elsevier Ltd. All rights reserved.

Determination of extraction equilibria for several metals in the development of a process designed to recover aluminum and other metals from coal combustion ash

Energy Technology Data Exchange (ETDEWEB)

Seeley, F.G.; McDowell, W.J.; Felker, L.K.; Kelmers, A.D.; Egan, B.Z.

1981-01-01

Laboratory-scale tests of several methods for the recovery of resource materials from fly ash have led to the development of a sinter/dilute acid leach method (Calsinter process) in which fly ash is sintered with a source of calcium oxide (CaCO/sub 3/, CaSO/sub 4/, CaO, and/or limestone flue-gas desulfurization scrubber sludge) at 1000 to 1200/sup 0/C, followed by a two-stage leach of the sintered solids with dilute sulfuric acid. Recovery of aluminum from this leach solution in a relatively pure form requires that several contaminants, particularly iron, must be separated from the aluminum before it can be precipitated. Therefore, distribution coefficients for iron (III) and 16 other metal ions have been determined in the liquid-liquid extraction system: Primene JM-T - toluene versus aqueous ammonium sulfate (and sodium sulfate) as a function of sulfate, acid, metal ion, and amine sulfate concentration. A study of iron (III) loading equilibria as a function of time indicated that equilibrium was essentially achieved in 1 h; however, some changes, probably in the nature of the extracted species, occurred over a period of approximately 20 h. Iron (III) extraction results obtained under various sulfate concentration matrix conditions suggested the formation of an aqueous complex of ferric ammonium sulfate, which depressed iron distribution to the organic phase. Extraction isotherms for Ag, As, Cd, Cr, and Fe all exhibit linearity at low loading conditions with unit slopes, including the same degree of association of the metal ion species in both the organic and the aqueous phase. Other metal ions for which distribution coefficients are reported are: Ba, Mg, Mn, Na, K, P, Pb, Th, Ti, and U.

Seasonal and spatial patterns of metals at a restored copper mine site. I. Stream copper and zinc

International Nuclear Information System (INIS)

Bambic, Dustin G.; Alpers, Charles N.; Green, Peter G.; Fanelli, Eileen; Silk, Wendy K.

2006-01-01

Seasonal and spatial variations in metal concentrations and pH were found in a stream at a restored copper mine site located near a massive sulfide deposit in the Foothill copper-zinc belt of the Sierra Nevada, California. At the mouth of the stream, copper concentrations increased and pH decreased with increased streamflow after the onset of winter rain and, unexpectedly, reached extreme values 1 or 2 months after peaks in the seasonal hydrographs. In contrast, aqueous zinc and sulfate concentrations were highest during low-flow periods. Spatial variation was assessed in 400 m of reach encompassing an acidic, metal-laden seep. At this seep, pH remained low (2-3) throughout the year, and copper concentrations were highest. In contrast, the zinc concentrations increased with downstream distance. These spatial patterns were caused by immobilization of copper by hydrous ferric oxides in benthic sediments, coupled with increasing downstream supply of zinc from groundwater seepage. - Seasonal hydrology and benthic sediments control copper and zinc concentrations in a stream through a restored mine site

Ferric Sulfate and Proline Enhance Heavy-Metal Tolerance of Halophilic/Halotolerant Soil Microorganisms and Their Bioremediation Potential for Spilled-Oil Under Multiple Stresses

Science.gov (United States)

Al-Mailem, Dina M.; Eliyas, Mohamed; Radwan, Samir S.

2018-01-01

The aim of this study was to explore the heavy-metal resistance and hydrocarbonoclastic potential of microorganisms in a hypersaline soil. For this, hydrocarbonoclastic microorganisms were counted on a mineral medium with oil vapor as a sole carbon source in the presence of increasing concentrations of ZnSO4, HgCl2, CdSO4, PbNO3, CuSO4, and Na2HAsO4. The colony-forming units counted decreased in number from about 150 g-1 on the heavy-metal-free medium to zero units on media with 40–100 mg l-1 of HgCl2, CdSO4, PbNO3, or Na2HAsO4. On media with CuSO4 or ZnSO4 on the other hand, numbers increased first reaching maxima on media with 50 mg l-1 CuSO4 and 90 mg l-1 ZnSO4. Higher concentrations reduced the numbers, which however, still remained considerable. Pure microbial isolates in cultures tolerated 200–1600 mg l-1 of HgCl2, CdSO4, PbNO3, CuSO4, and Na2HAsO4 in the absence of crude oil. In the presence of oil vapor, the isolates tolerated much lower concentrations of the heavy metals, only 10–80 mg l-1. The addition of 10 Fe2(SO4)3 and 200 mg l-1 proline (by up to two- to threefold) enhanced the tolerance of several isolates to heavy metals, and consequently their potential for oil biodegradation in their presence. The results are useful in designing bioremediation technologies for oil spilled in hypersaline areas. PMID:29563904

Optimizing iron delivery in the management of anemia: patient considerations and the role of ferric carboxymaltose

Directory of Open Access Journals (Sweden)

Toblli JE

2014-12-01

Full Text Available Jorge Eduardo Toblli, Margarita Angerosa Nephrology Section, Department of Internal Medicine, Hospital Alemán, School of Medicine, University of Buenos Aires, Argentina Abstract: With the challenge of optimizing iron delivery, new intravenous (iv iron–carbohydrate complexes have been developed in the last few years. A good example of these new compounds is ferric carboxymaltose (FCM, which has recently been approved by the US Food and Drug Administration for the treatment of iron deficiency anemia in adult patients who are intolerant to oral iron or present an unsatisfactory response to oral iron, and in adult patients with non-dialysis-dependent chronic kidney disease (NDD-CKD. FCM is a robust and stable complex similar to ferritin, which minimizes the release of labile iron during administration, allowing higher doses to be administered in a single application and with a favorable cost-effective rate. Cumulative information from randomized, controlled, multicenter trials on a diverse range of indications, including patients with chronic heart failure, postpartum anemia/abnormal uterine bleeding, inflammatory bowel disease, NDD-CKD, and those undergoing hemodialysis, supports the efficacy of FCM for iron replacement in patients with iron deficiency and iron-deficiency anemia. Furthermore, as FCM is a dextran-free iron–carbohydrate complex (which has a very low risk for hypersensitivity reactions with a small proportion of the reported adverse effects in a large number of subjects who received FCM, it may be considered a safe drug. Therefore, FCM appears as an interesting option to apply high doses of iron as a single infusion in a few minutes in order to obtain the quick replacement of iron stores. The present review on FCM summarizes diverse aspects such as pharmacology characteristics and analyzes trials on the efficacy/safety of FCM versus oral iron and different iv iron compounds in multiple clinical scenarios. Additionally, the

Effects of ferric ions on the catalytic ozonation process on sanitary landfill leachates

Directory of Open Access Journals (Sweden)

Messias Borges Silva

2013-04-01

Full Text Available Leachates exhibiting an unstable ratio of biochemical oxygen demand (BOD and chemical oxygen demand (COD of approximately 0.45 are typical of new landfills in the City of Cachoeira Paulista, Brazil. Although the organic matter portion is bio-treatable, the presence of refractory leached organic material requires unconventional effluent-treatment processes. Leachate treatment with ozone oxidation, in the presence of ferric ions, acts as catalyst in the formation of hydroxyl radicals. Ozone was obtained by corona-discharge from high-purity O2 gas. The treatment was performed in natura in a jacketed borosilicate glass reactor containing 900 ml of leachate. The analyzed response variable was expressed as the concentration of dissolved organic carbon (DOC. In order to determine the optimal proportions to produce the greatest degradation rate for organic materials, variations in experimental O2 flow-fed to the generator, the Fe(iii concentration, and the output of the ozonator were conducted over two experimental runs. Experimental models showed a DOC degradation on the order of 81.25%.

Studies on the preparation of ferric-hydroxide macro aggregate and hydroxyapatite particles labelled with Sm-153, Ho-166 and/or Dy-165 for radiation synovectomy

International Nuclear Information System (INIS)

Le Van So; Pham Ngoc Dien; Truong Hong Nghia; Nguyen Thi Thu; Nguyen Cong Duc; Vo Thji Cam Hoa; Bui Van Cuong

2004-01-01

The modified methods for the preparation of Hydroxyapatite particle (HA) and Ferric Hydroxide Macro Aggregated (FHMA of high stability and uniformity in particle size and of good geometrical shape suitable for production of radiolabeled carrier for radiation synovectomy purpose were developed. 165 Dy, 166 Ho and/or 153 Sm labeled HA and FHMA were produced using a simple labelling method. (author)

An investigation of magnox sludge and alumino-ferric floc waste simulate, immobilised by a cementitious matrix

International Nuclear Information System (INIS)

Halley, D.G.

1983-09-01

Magnox sludge and alumino ferric floc simulates, prepared using non-radioactive tracers were immobilised by a cementitious system. Formulation design aimed at optimising pollutant leaching with permeability and compressive strength as secondary considerations. The behaviour of the products under accelerated weathering conditions was investigated. The study was divided into two parts: Formulation design in Phase I and the systematic testing of the optimum formulations under freeze-thaw, and hydration -dehydration conditions in Phase 2. Analytical method development for leachate analysis continued through both Phases. The Barnwood method of leach testing was used. The immobilised waste had good physical properties (i.e. high strength and low permeability) and a significant improvement was achieved during the course of the work in the leach rates of the tracers, particularly of caesium and strontium. (author)

Nanofabrication de boites quantiques laterales pour l'optimisation de qubits de spin

Science.gov (United States)

Camirand Lemyre, Julien

On présente dans ce travail un nouveau type de qubit de spin dont les performances reposent sur les propriétés d'un seul électron dans une double boîte quantique. Le fort moment dipolaire de la double boite combiné à une large variation du champ magnétique entre les deux boîtes permettrait de réaliser des opérations logiques plus rapidement que dans une seule boîte quantique. Pour maximiser les variations du champ magnétique, on utilisera un micro-aimant placé le plus près possible d'une des deux boîtes. À cette fin, une hétérostructure de GaAs/A1GaAs sur laquelle sont déposées des grilles d'aluminium a été utilisée pour former une double boite quantique latérale. L'occupation par un seul électron de la double boîte est confirmée par des mesures de transport électrique à basse température ainsi que par l'observation du blocage de spin. De plus, un procédé d'oxydation des grilles par plasma d'oxygène a été développé. Une étude des propriétés de l'oxyde formé par cette méthode montre qu'il est possible de placer un micro-aimant directement sur la surface de l'hétérostructure sans affecter l'isolation électrique entre les grilles. Cette nouvelle approche permet de produire des champs magnétiques encore plus intenses que dans les expériences antérieures, pour lesquelles le micro-aimant est placé beaucoup plus loin de la surface. L'ensemble du procédé de fabrication, de la photolithographie à l'électrolithographie, a été développé au cours de ce travail dans les salles blanches du département de génie électrique et dans les salles propres du département de physique de l'Université de Sherbrooke. Ce travail est une étape importante dans la réalisation de qubits de spin plus performants dans les boîtes quantiques latérales. Mots-clés: Information quantique, Spin, Rotations ultra-rapides, Boîtes quantiques latérales, Micro-aimants, Oxydation plasma, Nanofabrication.

Low-cost fabrication technologies for nanostructures: state-of-the-art and potential

International Nuclear Information System (INIS)

Santos, A; Deen, M J; Marsal, L F

2015-01-01

In the last decade, some low-cost nanofabrication technologies used in several disciplines of nanotechnology have demonstrated promising results in terms of versatility and scalability for producing innovative nanostructures. While conventional nanofabrication technologies such as photolithography are and will be an important part of nanofabrication, some low-cost nanofabrication technologies have demonstrated outstanding capabilities for large-scale production, providing high throughputs with acceptable resolution and broad versatility. Some of these nanotechnological approaches are reviewed in this article, providing information about the fundamentals, limitations and potential future developments towards nanofabrication processes capable of producing a broad range of nanostructures. Furthermore, in many cases, these low-cost nanofabrication approaches can be combined with traditional nanofabrication technologies. This combination is considered a promising way of generating innovative nanostructures suitable for a broad range of applications such as in opto-electronics, nano-electronics, photonics, sensing, biotechnology or medicine. (topical review)

Low-cost fabrication technologies for nanostructures: state-of-the-art and potential

Science.gov (United States)

Santos, A.; Deen, M. J.; Marsal, L. F.

2015-01-01

In the last decade, some low-cost nanofabrication technologies used in several disciplines of nanotechnology have demonstrated promising results in terms of versatility and scalability for producing innovative nanostructures. While conventional nanofabrication technologies such as photolithography are and will be an important part of nanofabrication, some low-cost nanofabrication technologies have demonstrated outstanding capabilities for large-scale production, providing high throughputs with acceptable resolution and broad versatility. Some of these nanotechnological approaches are reviewed in this article, providing information about the fundamentals, limitations and potential future developments towards nanofabrication processes capable of producing a broad range of nanostructures. Furthermore, in many cases, these low-cost nanofabrication approaches can be combined with traditional nanofabrication technologies. This combination is considered a promising way of generating innovative nanostructures suitable for a broad range of applications such as in opto-electronics, nano-electronics, photonics, sensing, biotechnology or medicine.

The role of electrolyte anions (ClO4-, NO3-, and Cl-) in divalent metal (M2+) adsorption on oxide and hydroxide surfaces in salt solutions

International Nuclear Information System (INIS)

Criscenti, L.J.; Sverjensky, D.A.

1999-01-01

Adsorption of divalent metal ions (M 2+ ) onto oxide and hydroxide surfaces from solutions of strong electrolytes has typically been inferred to take place without the involvement of the electrolyte anion. Only in situations where M 2+ forms a strong enough aqueous complex with the electrolyte anion (for example, CdCl + or PbCl + ) has it been frequently suggested that the metal and the electrolyte anion adsorb simultaneously. A review of experimental data for the adsorption of Cd 2+ , Pb 2+ , Co 2+ , UO 2 2+ , Zn 2+ , Cu 2+ , Ba 2+ , Sr 2+ , and Ca 2+ onto quartz, silica, goethite, hydrous ferric oxide, corundum, γ-alumina, anatase, birnessite, and magnetite, from NaNO 3 , KNO 3 , NaCl, and NaClO 4 solutions over a wide range of ionic strengths (0.0001 M-1.0 M), reveals that transition and heavy metal adsorption behavior with ionic strength is a function of the type of electrolyte. In NaNO 3 solutions, metal adsorption exhibits little or no dependence on the ionic strength of the solution. However, in NaCl solutions, transition and heavy metal adsorption decreases strongly with increasing ionic strength. In NaClO 4 solutions, metal adsorption decreases strongly with increasing ionic strength. In NaClO 4 solutions, metal adsorption exhibits little dependence on ionic strength but is often suggestive of an increase in metal adsorption with increasing ionic strength. Analysis of selected adsorption edges was carried out using the extended triple-layer model and aqueous speciation models that included metal-nitrate, metal-chloride, and metal-hydroxide complexes

A hydro-geochemical study of Nahr-Ibrahim catchment area: Fluvial metal transport

International Nuclear Information System (INIS)

Korfali, Samira

2004-01-01

peaks only to calcite, dolomite and quartz. No speciation of metals in flood plain soils was done, nor XRD. The flood plain contains mostly terra rossa soils high in oxides and it is expected that the Ferric soil phase would have a major role in metal retention. The objective of this study is a complete hydro-geochemical survey of Nahr-Ibrahim catchment area and this study would clarify fluvial metal transport within the catchment area. The outcome of this work might assess the factors that influence water quality. This is attained through an improved knowledge of river hydrology, texture of sediment and soil, minerals in soil and sediment and soil and sediment geochemistry

Biosynthesis of Multicomponent Nanoparticles with Extract of Mortiño (Vaccinium floribundum Kunth Berry: Application on Heavy Metals Removal from Water and Immobilization in Soils

Directory of Open Access Journals (Sweden)

Mayra Abril

2018-01-01

Full Text Available Through preparation of multicomponent nanoparticles (MCNPs using ferric chloride (FeCl3, sodium sulfate (Na2SO4, and the extract of mortiño fruit (Vaccinium floribundum Kunth, we dramatically improved the removal/immobilization of heavy metals from water and in soils. As-prepared nanoparticles were spherical measuring approximately 12 nm in diameter and contained iron oxides and iron sulfides in the crystal structure. Removal of copper and zinc from water using MCNPs showed high efficiencies (>99% at pH above 6 and a ratio of 0.5 mL of the extract:10 mL 0.5 M FeCl3·6H2O : 10 mL 0.035 M Na2SO4. The physisorption process followed by chemisorption was regarded as the removal mechanism of Cu and Zn from water. While, when MCNPs were used to treat soils contaminated with heavy metals, more than 95% of immobilization was accomplished for all metals. Nevertheless, the distribution of the metallic elements changed in the soil fractions after treatment. Results indicate that immobilization of metals after the injection of nanoparticles into soils was effective. Metals did not leach out when soils were drained with rain, drinking, and deionized water but fairly leached out under acidic water drainage.

Differential scanning calorimetric study of HTPB based composite propellants in presence of nano ferric oxide

Energy Technology Data Exchange (ETDEWEB)

Patil, Prajakta R.; Krishnamurthy, V.N.; Joshi, Satyawati S. [Department of Chemistry, University of Pune, Pune 411007 (India)

2006-12-15

A comparative study of the thermal decomposition of ammonium perchlorate (AP)/hydroxy terminated polybutadiene (HTPB) based composite propellants has been carried out in presence and absence of nano iron oxide at different heating rates in a dynamic nitrogen atmosphere using differential scanning calorimetry. The pronounced effect was a lowering of the high temperature decomposition by 49 C. A higher heat release up to 40% was observed in presence of nano ferric oxide (3.5 nm). The kinetic parameters were evaluated using the Kissinger method. The increase of the rate constant in the catalyzed propellant confirmed the enhancement of the catalytic activity of ammonium perchlorate. The scanning electron micrographs of nano Fe{sub 2}O{sub 3} incorporated in HTPB revealed a well-separated characteristic necklace-like structure of {alpha}-Fe{sub 2}O{sub 3} particles at high magnification. (Abstract Copyright [2006], Wiley Periodicals, Inc.)

Plasmonic nanostructures: synthesis, functionalization & sensing applications

OpenAIRE

Yang, Wenjuan

2017-01-01

Nobel metal nanoparticles possess unique materials properties different from their corresponding bulk materials, which have sparked extensive research developments in the field of nanofabrication over the past few decades. In particular, the rational design of plasmonic nanoparticles (“artificial atoms”) is emerging as an exciting route for engineering material properties with high accuracy. Synthetic advances enable the sophisticated control over their size, shape, composition, and morpholog...

Special Advanced Studies for Pollution Prevention. Delivery Order 0065: The Monitor - Spring 2001

Science.gov (United States)

2001-06-01

coating) baths by remov- ing trace contaminant metals as well as restoring and maintaining the hexavalent chromium or ferric species. The oxidizing...power for the process acid is restored by oxidation (trivalent chromium to hexavalent chromium or ferrous to ferric) at the anode. Other sources of...selection to the application. UF membranes are suitable for particles in the molecular range of 0.1-0.01microns. Microfiltration membranes are similar

Formation, aggregation and reactivity of amorphous ferric oxyhydroxides on dissociation of Fe(III)-organic complexes in dilute aqueous suspensions

Science.gov (United States)

Bligh, Mark W.; Waite, T. David

2010-10-01

While chemical reactions that take place at the surface of amorphous ferric oxides (AFO) are known to be important in aquatic systems, incorporation of these reactions into kinetic models is hindered by a lack of ability to reliably quantify the reactivity of the surface and the changes in reactivity that occur over time. Long term decreases in the reactivity of iron oxides may be considered to result from changes in the molecular structure of the solid, however, over shorter time scales where substantial aggregation may occur, the mechanisms of reactivity loss are less clear. Precipitation of AFO may be described as a combination of homogeneous and heterogeneous reactions, however, despite its potentially significant role, the latter reaction is usually neglected in kinetic models of aquatic processes. Here, we investigate the role of AFO in scavenging dissolved inorganic ferric (Fe(III)) species (Fe') via the heterogeneous precipitation reaction during the net dissociation of organically complexed Fe(III) in seawater. Using sulfosalicylic acid (SSA) as a model ligand, AFO was shown to play a significant role in inducing the net dissociation of the Fe-SSA complexes with equations describing both the heterogeneous precipitation reaction and the aging of AFO being required to adequately describe the experimental data. An aggregation based mechanism provided a good description of AFO aging over the short time scale of the experiments. The behaviour of AFO described here has implications for the bioavailability of iron in natural systems as a result of reactions involving AFO which are recognised to occur over time scales of minutes, including adsorption of Fe' and AFO dissolution, precipitation and ageing.

Nanorobotic end-effectors: Design, fabrication, and in situ characterization

Science.gov (United States)

Fan, Zheng

Nano-robotic end-effectors have promising applications for nano-fabrication, nano-manufacturing, nano-optics, nano-medical, and nano-sensing; however, low performances of the conventional end-effectors have prevented the widespread utilization of them in various fields. There are two major difficulties in developing the end-effectors: their nano-fabrication and their advanced characterization in the nanoscale. Here we introduce six types of end-effectors: the nanotube fountain pen (NFP), the super-fine nanoprobe, the metal-filled carbon nanotube (m CNT)-based sphere-on-pillar (SOP) nanoantennas, the tunneling nanosensor, and the nanowire-based memristor. The investigations on the NFP are focused on nano-fluidics and nano-fabrications. The NFP could direct write metallic "inks" and fabricating complex metal nanostructures from 0D to 3D with a position servo control, which is critically important to future large-scale, high-throughput nanodevice production. With the help of NFP, we could fabricate the end-effectors such as super-fine nanoprobe and m CNT-based SOP nanoantennas. Those end-effectors are able to detect local flaws or characterize the electrical/mechanical properties of the nanostructure. Moreover, using electron-energy-loss-spectroscopy (EELS) technique during the operation of the SOP optical antenna opens a new basis for the application of nano-robotic end-effectors. The technique allows advanced characterization of the physical changes, such as carrier diffusion, that are directly responsible for the device's properties. As the device was coupled with characterization techniques of scanning-trasmission-electron-microscopy (STEM), the development of tunneling nanosensor advances this field of science into quantum world. Furthermore, the combined STEM-EELS technique plays an important role in our understanding of the memristive switching performance in the nanowire-based memristor. The developments of those nano-robotic end-effectors expend the study

Iron deficiency up-regulates iron absorption from ferrous sulphate but not ferric pyrophosphate and consequently food fortification with ferrous sulphate has relatively greater efficacy in iron-deficient individuals

NARCIS (Netherlands)

Zimmermann, M.B.; Biebinger, R.; Egli, I.; Zeder, C.; Hurrell, R.F.

2011-01-01

Fe absorption from water-soluble forms of Fe is inversely proportional to Fe status in humans. Whether this is true for poorly soluble Fe compounds is uncertain. Our objectives were therefore (1) to compare the up-regulation of Fe absorption at low Fe status from ferrous sulphate (FS) and ferric

Towards a More Complete Picture: Dissimilatory Metal Reduction by Anaeromyxobacter Species

International Nuclear Information System (INIS)

Loeffler, Frank E.

2004-01-01

We investigate the physiological requirements of available Anaeromyxobacter isolates, and assess their distribution and abundance in the environment, including DOE sites. The performers on this project include Frank Loeffler (PI), Robert Sanford (Co-PI), Qingzhong Wu (postdoc), Sara Henry (graduate student) and Cornell Gayle (undergraduate student). Year-1 efforts focused on method and tool development to address the research objectives. First, we compared different analytical assays (based on fluorescent light emission and calorimetric methods) to quantify U(VI) in cultures of Anaeromyxobacter dehalogenans strain 2CP-C. The assays were optimized to reflect specific culture conditions, and we found that a laser-excited spectrofluorescence assay provided reproducible and accurate information on the amount of U(VI) reduced in bacterial cultures. To demonstrate the ability of Anaeromyxobacter dehalogenans strain 2CP-C to reduce U(VI), washed suspensions of fumarate-grown cells were prepared. These experiments confirmed that the rapid reduction of U(VI) to U(IV) depended on the presence of live cells, and no U(VI) reduction occurred in cell-free controls. Additional experiments explored the ability of three different Anaeromyxobacter strains to grow with the mineral hematite, an insoluble form of ferric iron, as electron acceptor. All strain grew equally well with soluble ferric iron (provided as ferric citrate) but distinct differences were observed between strains when grown with hematite. All strains tested shared a 16S rRNA gene similarity of >99.5%, suggesting that closely related strains may differ in their ability to access insoluble forms of ferric iron

Stabilized-solubilized ferric pyrophosphate as a new iron source for food fortification. Bioavailability studies by means of the prophylactic-preventive method in rats.

Science.gov (United States)

Salgueiro, M J; Arnoldi, S; Kaliski, M A; Torti, H; Messeri, E; Weill, R; Zubillaga, M; Boccio, J

2009-02-01

The purpose of the present work was to evaluate the iron bioavailability of a new ferric pyrophosphate salt stabilized and solubilized with glycine. The prophylactic-preventive test in rats, using ferrous sulfate as the reference standard, was applied as the evaluating methodology both using water and yogurt as vehicles. Fifty female Sprague-Dawley rats weaned were randomized into five different groups (group 1: FeSO(4); group 2: pyr; group 3: FeSO(4) + yogurt; group 4: pyr + yogurt and group 5: control). The iron bioavailability (BioFe) of each compound was calculated using the formula proposed by Dutra-de-Oliveira et al. where BioFe % = (HbFef - HbFei) x 100/ToFeIn. Finally, the iron bioavailability results of each iron source were also given as relative biological value (RBV) using ferrous sulfate as the reference standard. The results showed that both BioFe % and RBV % of the new iron source tested is similar to that of the reference standard independently of the vehicle employed for the fortification procedure (FeSO(4) 49.46 +/- 12.0% and 100%; Pyr 52.66 +/- 15.02% and 106%; FeSO(4) + yogurth 54.39 +/- 13.92% and 110%; Pyr + yogurt 61.97 +/- 13.54% and 125%; Control 25.30 +/- 6.60, p soluble ferric pyrophosphate may be considered as an optimal iron source for food fortification.

Photodegradation of bisphenol A in simulated lake water containing algae, humic acid and ferric ions

International Nuclear Information System (INIS)

Peng Zhang'e; Wu Feng; Deng Nansheng

2006-01-01

The photodegradation of bisphenol A (BPA), a suspected endocrine disruptor (ED), in simulated lake water containing algae, humic acid and Fe 3+ ions was investigated. Algae, humic acid and Fe 3+ ions enhanced the photodegradation of BPA. Photodegradation efficiency of BPA was 36% after 4 h irradiation in the presence of 6.5 x 10 9 cells L -1 raw Chlorella vulgaris, 4 mg L -1 humic acid and 20 μmol L -1 Fe 3+ . The photodegradation efficiency of BPA was higher in the presence of algae treated with ultrasonic than that without ultrasonic. The photodegradation efficiency of BPA in the water only containing algae treated with ultrasonic was 37% after 4 h irradiation. The algae treated with heating can also enhance the photodegradation of BPA. This work helps environmental scientists to understand the photochemical behavior of BPA in lake water. - Algae, humic acid and ferric ions can induce the photodegradation of bisphenol A in an aqueous environment

Photodegradation of bisphenol A in simulated lake water containing algae, humic acid and ferric ions

Energy Technology Data Exchange (ETDEWEB)

Peng Zhang' e [School of Resources and Environmental Science, Wuhan University, Wuhan 430079 (China)]. E-mail: zhepeng@126.com; Wu Feng [School of Resources and Environmental Science, Wuhan University, Wuhan 430079 (China)]. E-mail: fengwu@whu.edu.cn; Deng Nansheng [School of Resources and Environmental Science, Wuhan University, Wuhan 430079 (China)]. E-mail: nsdengwhu@163.com

2006-12-15

The photodegradation of bisphenol A (BPA), a suspected endocrine disruptor (ED), in simulated lake water containing algae, humic acid and Fe{sup 3+} ions was investigated. Algae, humic acid and Fe{sup 3+} ions enhanced the photodegradation of BPA. Photodegradation efficiency of BPA was 36% after 4 h irradiation in the presence of 6.5 x 10{sup 9} cells L{sup -1} raw Chlorella vulgaris, 4 mg L{sup -1} humic acid and 20 {mu}mol L{sup -1} Fe{sup 3+}. The photodegradation efficiency of BPA was higher in the presence of algae treated with ultrasonic than that without ultrasonic. The photodegradation efficiency of BPA in the water only containing algae treated with ultrasonic was 37% after 4 h irradiation. The algae treated with heating can also enhance the photodegradation of BPA. This work helps environmental scientists to understand the photochemical behavior of BPA in lake water. - Algae, humic acid and ferric ions can induce the photodegradation of bisphenol A in an aqueous environment.

Selective depression mechanism of ferric chromium lignin sulfonate for chalcopyrite-galena flotation separation

Science.gov (United States)

Yu, Jin-sheng; Liu, Run-qing; Wang, Li; Sun, Wei; Peng, Hong; Hu, Yue-hua

2018-05-01

Selective recovery of chalcopyrite-galena ore by flotation remains a challenging issue. The development of highly efficient, low-cost, and environmentally friendly depressants for this flotation is necessary because most of available reagents (e.g., K2Cr2O4) are expensive and adversely affect the environment. In this study, ferric chromium lignin sulfonate (FCLS), which is a waste-product from the paper and pulp industry, was introduced as a selective depressant for galena with butyl xanthate (BX) as a collector. Results show that the residue recovery of Pb in Cu concentrate was substantially reduced to 4.73% using FCLS compared with 10.71% using the common depressant K2Cr2O4. The underlying mechanisms were revealed using zeta-potential measurements and X-ray photoelectron spectroscopy (XPS). Zeta-potential measurements revealed that FCLS was more efficiently absorbed onto galena than onto chalcopyrite. XPS measurements further suggested that FCLS enhanced the surface oxidation of galena but prevented that of chalcopyrite. Thus, FCLS could be a potential candidate as a depressant for chalcopyrite-galena flotation because of its low cost and its lack of detrimental effects on the environment.

Simultaneous separation of copper, cadmium and cobalt from sea-water by co-flotation with octadecylamine and ferric hydroxide as collectors.

Science.gov (United States)

Cabezon, L M; Caballero, M; Cela, R; Perez-Bustamante, J A

1984-08-01

A method is proposed for the simultaneous quantitative separation of traces ofCu(II), Cd(II) and Co(II) from sea-water samples by means of the co-flotation (adsorbing colloid flotation) technique with ferric hydroxide as co-precipitant and octadecylamine as collector. The experimental parameters have been studied and optimized. The drawbacks arising from the low solubility of octadecylamine and the corresponding sublates in water have been avoided by use of a 6M hydrochloric acid-MIBK-ethanol (1:2:2 v v ) mixture. The results obtained by means of the proposed method have been compared with those given by the usual ammonium pyrrolidine dithiocarbamate/MIBK extraction method.

Comparative impacts of iron oxide nanoparticles and ferric ions on the growth of Citrus maxima.

Science.gov (United States)

Hu, Jing; Guo, Huiyuan; Li, Junli; Gan, Qiuliang; Wang, Yunqiang; Xing, Baoshan

2017-02-01

The impacts of iron oxide nanoparticles (γ-Fe 2 O 3 NPs) and ferric ions (Fe 3+ ) on plant growth and molecular responses associated with the transformation and transport of Fe 2+ were poorly understood. This study comprehensively compared and evaluated the physiological and molecular changes of Citrus maxima plants as affected by different levels of γ-Fe 2 O 3 NPs and Fe 3+ . We found that γ-Fe 2 O 3 NPs could enter plant roots but no translocation from roots to shoots was observed. 20 mg/L γ-Fe 2 O 3 NPs had no impact on plant growth. 50 mg/L γ-Fe 2 O 3 NPs significantly enhanced chlorophyll content by 23.2% and root activity by 23.8% as compared with control. However, 100 mg/L γ-Fe 2 O 3 NPs notably increased MDA formation, decreased chlorophyll content and root activity. Although Fe 3+ ions could be used by plants and promoted the synthesis of chlorophyll, they appeared to be more toxic than γ-Fe 2 O 3 NPs, especially for 100 mg/L Fe 3+ . The impacts caused by γ-Fe 2 O 3 NPs and Fe 3+ were concentration-dependent. Physiological results showed that γ-Fe 2 O 3 NPs at proper concentrations had the potential to be an effective iron nanofertilizer for plant growth. RT-PCR analysis showed that γ-Fe 2 O 3 NPs had no impact on AHA gene expression. 50 mg/L γ-Fe 2 O 3 NPs and Fe 3+ significantly increased expression levels of FRO2 gene and correspondingly had a higher ferric reductase activity compared to both control and Fe(II)-EDTA exposure, thus promoting the iron transformation and enhancing the tolerance of plants to iron deficiency. Relative levels of Nramp3 gene expression exposed to γ-Fe 2 O 3 NPs and Fe 3+ were significantly lower than control, indicating that all γ-Fe 2 O 3 NPs and Fe 3+ treatments could supply iron to C. maxima seedlings. Overall, plants can modify the speciation and transport of γ-Fe 2 O 3 NPs or Fe 3+ for self-protection and development by activating many physiological and molecular processes. Copyright © 2016 Elsevier

A voltammetric method for Fe(iii) in blood serum using a screen-printed electrode modified with a Schiff base ionophore.

Science.gov (United States)

Mittal, Susheel K; Rana, Sonia; Kaur, Navneet; Banks, Craig E

2018-05-23

Herein, a potent electrochemical ionophore (SMS-2) based on a Schiff base has been used for the modification of a screen-printed electrode (SPE). The modified disposable electrode can selectively detect ferric ions in an aqueous medium. Redox behavior of the proposed strip was characterized using cyclic voltammetry (CV) and differential pulse voltammetry (DPV). Incorporation of the ligand in the ink of the SPE enhanced the analytical performance of the electrode, and its surface modification was confirmed by SEM and EDX analysis. Shifting/quenching of the cathodic peak potential of the ionophore after binding with Fe(iii) ions was used to detect and measure the ferric ion concentration. This sensor can identify Fe(iii) in the detection range from 0.625 μM to 7.5 μM. The modified SPE can selectively detect ferric ions in the presence of many other interfering ions and has been successfully used to determine the Fe(iii) content in blood serum samples. The metal-ionophore complex structure was optimized using DFT calculations to study the energetics of the metal-ionophore interactions.

New Insight into the Local Structure of Hydrous Ferric Arsenate Using Full-Potential Multiple Scattering Analysis, Density Functional Theory Calculations, and Vibrational Spectroscopy.

Science.gov (United States)

Wang, Shaofeng; Ma, Xu; Zhang, Guoqing; Jia, Yongfeng; Hatada, Keisuke

2016-11-15

Hydrous ferric arsenate (HFA) is an important arsenic-bearing precipitate in the mining-impacted environment and hydrometallurgical tailings. However, there is no agreement on its local atomic structure. The local structure of HFA was reprobed by employing a full-potential multiple scattering (FPMS) analysis, density functional theory (DFT) calculations, and vibrational spectroscopy. The FPMS simulations indicated that the coordination number of the As-Fe, Fe-As, or both in HFA was approximately two. The DFT calculations constructed a structure of HFA with the formula of Fe(HAsO 4 ) x (H 2 AsO 4 ) 1-x (OH) y ·zH 2 O. The presence of protonated arsenate in HFA was also evidenced by vibrational spectroscopy. The As and Fe K-edge X-ray absorption near-edge structure spectra of HFA were accurately reproduced by FPMS simulations using the chain structure, which was also a reasonable model for extended X-Ray absorption fine structure fitting. The FPMS refinements indicated that the interatomic Fe-Fe distance was approximately 5.2 Å, consistent with that obtained by Mikutta et al. (Environ. Sci. Technol. 2013, 47 (7), 3122-3131) using wavelet analysis. All of the results suggested that HFA was more likely to occur as a chain with AsO 4 tetrahedra and FeO 6 octahedra connecting alternately in an isolated bidentate-type fashion. This finding is of significance for understanding the fate of arsenic and the formation of ferric arsenate minerals in an acidic environment.

Electrochemical peroxidation as a tool to remove arsenic and copper from smelter wastewater

DEFF Research Database (Denmark)

Gutiérrez, Claudia; Hansen, Henrik K.; Nuñez, Patricio

2010-01-01

Electrochemical peroxidation (ECP) is a method that recently has been applied in the treatment of heavy metal polluted wastewater. This method is based on the anodic dissolution of iron to ferrous ions that reacts with H2O2 to produce tiny particles of ferric oxides. These oxides adsorb metals ef...

Determination of residual fluoroquinolones in honey by liquid chromatography using metal chelate affinity chromatography.

Science.gov (United States)

Yatsukawa, Yoh-Ichi; Ito, Hironobu; Matsuda, Takahiro; Nakamura, Munetomo; Watai, Masatoshi; Fujita, Kazuhiro

2011-01-01

A new analytical method for the simultaneous determination of seven fluoroquinolones, namely, norfloxacin, ciprofloxacin, danofloxacin, enrofloxacin, orbifloxacin, sarafloxacin, and difloxacin, especially in dark-colored honey, has been developed. Fluoroquinolone antibiotics were extracted from samples with MacIlvaine buffer solution (pH 4.0) containing EDTA disodium salt dihydrate. The extracts were treated with both a polymeric cartridge and a metal chelate affinity column preloaded with ferric ion (Fe3+). LC separation with fluorescence detection was performed at 40 degrees C using an Inertsil ODS-4 analytical column (150 x 4.6 mm, 3 microm). The mobile phase was composed of 20 mM/L citrate buffer solution (pH 3.1)-acetonitrile mixture (70 + 30, v/v) containing 1 mM/L sodium dodecyl sulfate. Lomefloxacin was used as an internal standard. The developed method was validated according to the criteria of European Commission Decision 2002/657/EC. Decision limits and detection capabilities were below 2.9 and 4.4 microg/kg, respectively.

Theory favors a stepwise mechanism of porphyrin degradation by a ferric hydroperoxide model of the active species of heme oxygenase.

Science.gov (United States)

Kumar, Devesh; de Visser, Samuël P; Shaik, Sason

2005-06-08

The report uses density functional theory to address the mechanism of heme degradation by the enzyme heme oxygenase (HO) using a model ferric hydroperoxide complex. HO is known to trap heme molecules and degrade them to maintain iron homeostasis in the biosystem. The degradation is initiated by complexation of the heme, then formation of the iron-hydroperoxo species, which subsequently oxidizes the meso position of the porphyrin by hydroxylation, thereby enabling eventually the cleavage of the porphyrin ring. Kinetic isotope effect studies indicate that the mechanism is assisted by general acid catalysis, via a chain of water molecules, and that all the events occur in concert. However, previous theoretical treatments indicated that the concerted mechanism has a high barrier, much higher than an alternative mechanism that is initiated by O-O bond homolysis of iron-hydroperoxide. The present contribution studies the stepwise and concerted acid-catalyzed mechanisms using H(3)O(+)(H(2)O)(n)(), n = 0-2. The effect of the acid strength is tested using the H(4)N(+)(H(2)O)(2) cluster and a fully protonated ferric hydroperoxide. All the calculations show that a stepwise mechanism that involves proton relay and O-O homolysis, in the rate-determining step, has a much lower barrier (>10 kcal/mol) than the corresponding fully concerted mechanism. The best fit of the calculated solvent kinetic isotope effect, to the experimental data, is obtained for the H(3)O(+)(H(2)O)(2) cluster. The calculated alpha-deuterium secondary kinetic isotope effect is inverse (0.95-0.98), but much less so than the experimental value (0.7). Possible reasons for this quantitative difference are discussed. Some probes are suggested that may enable experiment to distinguish the stepwise from the concerted mechanism.

Determination of the molar extinction coefficient for the ferric reducing/antioxidant power assay.

Science.gov (United States)

Hayes, William A; Mills, Daniel S; Neville, Rachel F; Kiddie, Jenna; Collins, Lisa M

2011-09-15

The FRAP reagent contains 2,4,6-tris(2-pyridyl)-s-triazine, which forms a blue-violet complex ion in the presence of ferrous ions. Although the FRAP (ferric reducing/antioxidant power) assay is popular and has been in use for many years, the correct molar extinction coefficient of this complex ion under FRAP assay conditions has never been published, casting doubt on the validity of previous calibrations. A previously reported value of 19,800 is an underestimate. We determined that the molar extinction coefficient was 21,140. The value of the molar extinction coefficient was also shown to depend on the type of assay and was found to be 22,230 under iron assay conditions, in good agreement with published data. Redox titration indicated that the ferrous sulfate heptahydrate calibrator recommended by Benzie and Strain, the FRAP assay inventors, is prone to efflorescence and, therefore, is unreliable. Ferrous ammonium sulfate hexahydrate in dilute sulfuric acid was a more stable alternative. Few authors publish their calibration data, and this makes comparative analyses impossible. A critical examination of the limited number of examples of calibration data in the published literature reveals only that Benzie and Strain obtained a satisfactory calibration using their method. Copyright © 2011 Elsevier Inc. All rights reserved.

Polyethyleneimine-templated copper nanoclusters via ascorbic acid reduction approach as ferric ion sensor

Energy Technology Data Exchange (ETDEWEB)

Feng, Jie; Ju, Yuyun; Liu, Juanjuan; Zhang, Huige [State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000 (China); Department of Chemistry, Lanzhou University, Lanzhou 730000 (China); Chen, Xingguo, E-mail: chenxg@lzu.edu.cn [State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000 (China); Department of Chemistry, Lanzhou University, Lanzhou 730000 (China); Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province, Lanzhou 730000 (China)

2015-01-07

Highlights: • A new method for synthesis of the BPEI-CuNCs is established. • A facile approach for Fe{sup 3+} ion sensing by fluorescence quenching is developed. • The method for Fe{sup 3+} sensing has high sensitivity and excellent selectivity. - Abstract: In this report we reported a facile one-pot method for synthesis of water-soluble and stable fluorescent CuNCs at room temperature, in which branched polyethyleneimine (BPEI) served as capping scaffold and ascorbic acid as reducing agent. The prepared BPEI-CuNCs exhibited excellent properties such as good water-solubility, photostability and high stability toward high ionic strength. Based on the electron transfer induced fluorescence quenching mechanism, this fluorescence probe was used for the sensitive and selective determination of ferric ions (Fe{sup 3+}) in aqueous solution. The limit of detection was 340 nM in the linear range of 0.5–1000 μM, which was lower than the maximum level of Fe{sup 3+} permitted in drinking water by the U.S. Environmental Protection Agency. The method was successfully applied to the detection of Fe{sup 3+} in tap water, Yellow River water and human urine samples with the quantitative spike recoveries ranging from 95.3% to 112.0%.

Polyethyleneimine-templated copper nanoclusters via ascorbic acid reduction approach as ferric ion sensor

International Nuclear Information System (INIS)

Feng, Jie; Ju, Yuyun; Liu, Juanjuan; Zhang, Huige; Chen, Xingguo

2015-01-01

Highlights: • A new method for synthesis of the BPEI-CuNCs is established. • A facile approach for Fe 3+ ion sensing by fluorescence quenching is developed. • The method for Fe 3+ sensing has high sensitivity and excellent selectivity. - Abstract: In this report we reported a facile one-pot method for synthesis of water-soluble and stable fluorescent CuNCs at room temperature, in which branched polyethyleneimine (BPEI) served as capping scaffold and ascorbic acid as reducing agent. The prepared BPEI-CuNCs exhibited excellent properties such as good water-solubility, photostability and high stability toward high ionic strength. Based on the electron transfer induced fluorescence quenching mechanism, this fluorescence probe was used for the sensitive and selective determination of ferric ions (Fe 3+ ) in aqueous solution. The limit of detection was 340 nM in the linear range of 0.5–1000 μM, which was lower than the maximum level of Fe 3+ permitted in drinking water by the U.S. Environmental Protection Agency. The method was successfully applied to the detection of Fe 3+ in tap water, Yellow River water and human urine samples with the quantitative spike recoveries ranging from 95.3% to 112.0%

Will the application of Ammonium-Ferric-Hexacyano-Ferrate enhance the vertical migration of radiocaesium?

International Nuclear Information System (INIS)

Vandenhove, H.; Bacquoy, C.; Hees, M. van; Lewyckyj, N.; Vandecasteele, C.

1998-01-01

The consideration of a possible enhanced vertical migration of radiocaesium with the application of ammonium-ferric-hexacyano-ferrate (AFCF) as countermeasure, due to the colloidal nature of AFCF, made us set up a series of migration experiments. For the study two soil types were considered, which were either left unplanted or cultivated with ryegrass. Two AFCF concentrations, 1 and 10 g m -2 , and an untreated control were applied. A simple diffusion-convection model was fitted to the data.The application of AFCF did not enhance the downward migration of radiocaesium in the profile. Moreover, for an unplanted sandy soil the application of AFCF significantly retarded the migration: 10 g AFCF m -2 decreased the convection term, V, from 0·78 to 0·42 cm a -1 and the diffusion component, D, from 0·21 to 0·09 cm 2 a -1 . For all other experimental conditions (unplanted loamy soil, ryegrass cultivated sandy and loamy soil), the application of AFCF did not have any effect on radiocaesium migration. Since AFCF does not promote the vertical migration of radiocaesium, enhanced groundwater contamination is improbable. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

Bottom-Up Nanofabrication of Supported Noble Metal Alloy Nanoparticle Arrays for Plasmonics

DEFF Research Database (Denmark)

Nugroho, Ferry A. A.; Iandolo, Beniamino; Wagner, Jakob Birkedal

2016-01-01

Mixing different elements at the nanoscale to obtain alloy nanostructures with fine-tuned physical and chemical properties offers appealing opportunities for nanotechnology and nanoscience. However, despite widespread successful application of alloy nanoparticles made by colloidal synthesis...... in heterogeneous catalysis, nanoalloy systems have been used very rarely in solid-state devices and nanoplasmonics-related applications. One reason is that such applications require integration in arrays on a surface with compelling demands on nanoparticle arrangement, uniformity in surface coverage......, and optimization of the surface density. These cannot be fulfilled even using state-of-the-art self -assembly strategies of colloids. As a solution, we present here a generic bottom-up nanolithography-compatible fabrication approach for large-area arrays of alloy nanoparticles on surfaces. To illustrate...

Heavy metal removal mechanisms of sorptive filter materials for road runoff treatment and remobilization under de-icing salt applications.

Science.gov (United States)

Huber, Maximilian; Hilbig, Harald; Badenberg, Sophia C; Fassnacht, Julius; Drewes, Jörg E; Helmreich, Brigitte

2016-10-01

The objective of this research study was to elucidate the removal and remobilization behaviors of five heavy metals (i.e., Cd, Cu, Ni, Pb, and Zn) that had been fixed onto sorptive filter materials used in decentralized stormwater treatment systems receiving traffic area runoff. Six filter materials (i.e., granular activated carbon, a mixture of granular activated alumina and porous concrete, granular activated lignite, half-burnt dolomite, and two granular ferric hydroxides) were evaluated in column experiments. First, a simultaneous preloading with the heavy metals was performed for each filter material. Subsequently, the remobilization effect was tested by three de-icing salt experiments in duplicate using pure NaCl, a mixture of NaCl and CaCl2, and a mixture of NaCl and MgCl2. Three layers of each column were separated to specify the attenuation of heavy metals as a function of depth. Cu and Pb were retained best by most of the selected filter materials, and Cu was often released the least of all metals by the three de-icing salts. The mixture of NaCl and CaCl2 resulted in a stronger effect upon remobilization than the other two de-icing salts. For the material with the highest retention, the effect of the preloading level upon remobilization was measured. The removal mechanisms of all filter materials were determined by advanced laboratory methods. For example, the different intrusions of heavy metals into the particles were determined. Findings of this study can result in improved filter materials used in decentralized stormwater treatment systems. Copyright © 2016 Elsevier Ltd. All rights reserved.

Measurement of the ferric diffusion coefficient in agarose and gelatine gels by utilization of the evolution of a radiation induced edge as reflected in relaxation rate images

International Nuclear Information System (INIS)

Pedersen, Torje V.; Olsen, Dag R.; Skretting, Arne

1997-01-01

A method has been developed to determine the diffusion coefficients of ferric ions in ferrous sulphate doped gels. A radiation induced edge was created in the gel, and two spin-echo sequences were used to acquire a pair of images of the gel at different points of time. For each of these image pairs, a longitudinal relaxation rate image was derived. From profiles through these images, the standard deviations of the Gaussian functions that characterize diffusion were determined. These data provided the basis for the determination of the ferric diffusion coefficients by two different methods. Simulations indicate that the use of single spin-echo images in this procedure may in some cases lead to a significant underestimation of the diffusion coefficient. The technique was applied to different agarose and gelatine gels that were prepared, irradiated and imaged simultaneously. The results indicate that the diffusion coefficient is lower in a gelatine gel than in an agarose gel. Addition of xylenol orange to a gelatine gel lowers the diffusion coefficient from 1.45 to 0.81 mm 2 h -1 , at the cost of significantly lower R 1 sensitivity. The addition of benzoic acid to the latter gel did not increase the R 1 sensitivity. (author) OK

The influence of ferric iron in calcined nano-Mg/Al hydrotalcite on adsorption of Cr (VI) from aqueous solution

Energy Technology Data Exchange (ETDEWEB)

Xiao Lili [College of Chemistry, Dalian University of Technology, Dalian, Liaoning 116023 (China); Ma Wei, E-mail: chmawv@yahoo.com [College of Chemistry, Dalian University of Technology, Dalian, Liaoning 116023 (China); Han Mei; Cheng Zihong [College of Chemistry, Dalian University of Technology, Dalian, Liaoning 116023 (China)

2011-02-15

Research highlights: {yields} The reconstruction processes of CH-Mg/Al and CH-Mg/Al/Fe were fast and efficient, but the adsorption of Cr (VI) on CH-Mg/Al/Fe reached equilibrium faster. {yields} The removal mechanism involved not only intercalation but also adsorption on external surface of the layers and interlayer anion exchange. {yields} The existence of Fe3{sup +} in Mg/Al calcined hydrotalcite led to the interlayer anion exchange more difficult and it is affected equilibrium amount of Cr (VI) adsorption. - Abstract: The influence of ferric iron in calcined nano-Mg/Al hydrotalcite on removal of Cr (VI) from aqueous solution was studied from aspects of structure characteristics, adsorption properties and mechanism discussions. The calcined hydrotalcites (CH-Mg/Al and CH-Mg/Al/Fe) were obtained by thermal decomposition of their corresponding precursors and characterized by XRD, TEM, pH{sub PZC} and FTIR. The adsorption properties were studied as a function of pH, initial Cr (VI) concentration and contact time. The results showed that the nature of adsorption is endothermic and spontaneous for both CH-Mg/Al and CH-Mg/Al/Fe, but the thermodynamic parameter value changes revealed the addition of Fe{sup 3+} is disadvantage to adsorption process and the theoretical saturated adsorption capacity decreased by approximately 10.2 mg/g at tested temperatures. The removal mechanism involved not only intercalation but adsorption on external surface of the layers and interlayer anion exchange for both CH-Mg/Al and CH-Mg/Al/Fe. Furthermore, the results also indicated that intercalation accounts for a large proportion during removal process whatever for CH-Mg/Al, or for CH-Mg/Al/Fe. Additionally, the replacement of Al{sup 3+} by Fe{sup 3+} in CH-Mg/Al led to the interlayer anion exchange more difficult. On the basis of the results, it is concluded that the existence of ferric iron in calcined Mg/Al hydrotalcite is unfavorable to removal of Cr (VI) from aqueous solution.

Highly efficient removal of trace thallium from contaminated source waters with ferrate: Role of in situ formed ferric nanoparticle.

Science.gov (United States)

Liu, Yulei; Wang, Lu; Wang, Xianshi; Huang, Zhuangsong; Xu, Chengbiao; Yang, Tao; Zhao, Xiaodan; Qi, Jingyao; Ma, Jun

2017-11-01

Thallium (Tl) is highly toxic to mammals and relevant pollution cases are increasing world-widely. Convenient and efficient method for the removal of trace Tl from contaminated source water is imperative. Here, the removal of trace Tl by K 2 FeO 4 [Fe(VI)] was investigated for the first time, with the exploration of reaction mechanisms. Six different types of water treatment agents (powdered activated carbon, Al 2 (SO 4 ) 3 , FeCl 3 , δ-MnO 2 , MnO 2 nano-particles, and K 2 FeO 4 ) were used for the removal of Tl in spiked river water, and K 2 FeO 4 showed excellent removal performance. Over 92% of Tl (1 μg/L) was removed within 5 min by applying 2.5 mg/L of K 2 FeO 4 (pH 7.0, 20 °C). XPS analysis revealed that in the reaction of Tl(I) with K 2 FeO 4 , Tl(I) was oxidized to Tl(III), and removed by the K 2 FeO 4 reduced ferric particles. The removal of Tl by in situ formed and ex situ formed ferric particle was examined respectively, and the results revealed that the removal of trace Tl could be attributed to the combination of adsorption and coprecipitation processes. The hydrodynamic size of the reduced particle from K 2 FeO 4 ranged from 10 nm to 100 nm, and its surface was negatively charged under neutral pH condition. These factors were conducive for the efficient removal of Tl by K 2 FeO 4 . The effects of solution pH, coexisting ions (Na + , Ca 2+ , and HCO 3 - ), humic acid, solution temperature, and reductive environment on the removal and desorption of Tl were investigated, and the elimination of Tl in polluted river water and reservoir water was performed. These results suggest that K 2 FeO 4 could be an efficient and convenient agent on trace Tl removal. Copyright © 2017. Published by Elsevier Ltd.

Optical and electrical properties of thin films of bismuth ferric oxide; Propiedades opticas y electricas de peliculas delgadas de oxido de bismuto ferrico

Energy Technology Data Exchange (ETDEWEB)

Cardona R, D.

2014-07-01

The bismuth ferric oxide (BFO) has caused great attention in recent years because of their multi ferric properties, making it very attractive for different technological applications. In this paper simultaneous ablation of two white (Bi and Fe{sub 2}O{sub 3}) was used in a reactive atmosphere (containing oxygen) to deposit thin films of BFO. The composition of the films is changed by controlling the plasma parameters such as the average kinetic energy of the ions (E p) and the plasma density (Np). The effects caused by excess of Bi and Fe in atomic structure and the optical and electrical properties of the films BiFeO{sub 3} in terms of plasma parameters were studied. The X-ray diffraction patterns of BFO samples with excess of bismuth above 2% at. They exhibited small changes in structure leading to improved levels of leakage currents compared to levels of the film with a stoichiometry close to BiFeO{sub 3} composition. These samples showed a secondary phase (Bi{sub 2}5FeO{sub 4}0 selenite type) that led to the increase in the values of band gap and resistivity as well as the improvement of the piezoelectric properties. On the other hand, the films with iron excess showed as secondary phase compounds of iron oxide (α - γ-Fe{sub 2}O{sub 3}) that caused increments in the conductivity and decrease in the values of band gap. The results are discussed in terms of the excesses of Bi and Fe which were correlated with the plasma parameters. (Author)

Direct fabrication of rigid microstructures on a metallic roller using a dry film resist

International Nuclear Information System (INIS)

Jiang, Liang-Ting; Huang, Tzu-Chien; Chang, Chih-Yuan; Ciou, Jian-Ren; Yang, Sen-Yeu; Huang, Po-Hsun

2008-01-01

This paper presents a novel method to fabricate a metallic roller mold with microstructures on its surface using a dry film resist (DFR). The DFR is laminated uniformly onto the curvy surface of a copper roller. After that, the micro-scale photoresist on the surface of the roller can be patterned by non-planar lithography using a flexible film photomask, followed by ferric chloride wet etching to obtain the desired microstructures. This method overcomes the uniformity issue of photoresist coating on rollers, and solves the molds sliding problem during the embossing process because the microstructures are fabricated directly on the roller surface. Furthermore, the rigid metallic roller mold has excellent strength durability and temperature endurance, which can be used in roller hot embossing with a high embossing pressure. The fabricated microstructure roller mold is used as a mold in the hybrid extrusion roller embossing process and successfully fabricates uniform micro-scale prominent line arrays on PC films. This result proves that the roller fabricated by this method can be successfully used in roller embossing for microstructure mass production. The excellent flatness of dry film resist laminating is the key in this fabrication process. The flexible film photomask can be easily designed using CAD software; this roller fabrication method enhances the design flexibility and reduces the cost and time

Evaluation of candidate alloys for the construction of metal flex hoses in the STS launch environment

Science.gov (United States)

Ontiveros, Cordelia

1988-01-01

Various vacuum jacketed cryogenic supply lines at the Shuttle launch site use convoluted flexible expansion joints. The atmosphere at the launch site has a very high salt content, and during a launch, fuel combustion products include hydrochloric acid. This extremely corrosive environment has caused pitting corrosion failure in the flex hoses, which were made of 304L stainless steel. A search was done to find a more corrosion resistant replacement material. This study focused on 19 metal alloys. Tests which were performed include electrochemical corrosion testing, accelerated corrosion testing in a salt fog chamber, long term exposure at the beach corrosion testing site, and pitting corrosion tests in ferric chloride solution. Based on the results of these tests, the most corrosion resistant alloys were found to be (in order) Hastelloy C-22, Inconel 625, Hastelloy C-276, Hastelloy C-4, and Inco Alloy G-3. Of these top five alloys, the Hastelloy C-22 stands out as being the best of those tested for this application.

Ferric oxide nanoparticles decorated carbon nanotubes and carbon nanofibers: From synthesis to enhanced removal of phenol

Directory of Open Access Journals (Sweden)

Hamza A. Asmaly

2015-09-01

Full Text Available In this work, ferric oxide nanoparticle decorated carbon fibers and carbon nanotubes (CNF/Fe2O3 and CNT/Fe2O3 were synthesized and characterized by scanning electron microscopy (SEM, thermogravimetric analysis (TGA, energy dispersive X-ray spectroscopy (EDS, transmission electron microscopy (TEM, X-ray diffraction (XRD, zeta potential and BET surface area analyzer. The prepared nanocomposites were evaluated or the removal of phenol ions from aqueous solution. The effects of experimental parameters, such as shaking speed, pH, contact time, adsorbent dosage and initial concentration, were evaluated for the phenol removal efficiency. The adsorption experimental data were represented by both the Langmuir and Freundlich isotherm models. The Langmuir isotherm model best fitted the data on the adsorption of phenol, with a high correlation coefficient. The adsorption capacities, as determined by the Langmuir isotherm model were 0.842, 1.098, 1.684 and 2.778 mg/g for raw CNFs, raw CNTs, CNF–Fe2O3 and CNT–Fe2O3, respectively.

Nanofabrication of SERS Substrates for Single/Few Molecules Detection

KAUST Repository

Melino, Gianluca

2015-05-04

Raman spectroscopy is among the most widely employed methods to investigate the properties of materials in several fields of study. Evolution in materials science allowed us to fabricate suitable substrates, at the nanoscale, capable to enhance the electromagnetic field of the signals coming from the samples which at this range turn out to be in most cases singles or a few molecules. This particular variation of the classical technique is called SERS (Surface Enanched Raman Spectroscopy). In this work, the enhancement of the electromagnetic field is obtained by manipulation of the optical properties of metals with respect to their size. By using electroless deposition (bottom up technique), gold and silver nanoparticles were deposited in nanostructured patterns obtained on silicon wafers by means of electron beam lithography (top down technique). Rhodamine 6G in aqueous solution at extremely low concentration (10-8 M) was absorbed on the resultant dimers and the collection of the Raman spectra demonstrated the high efficiency of the substrates.

Total phenolic content and in-vitro antioxidant activities from methanolic extract of alligator pipefish, Syngnathoides biaculeatus (Bloch, 1785)

Digital Repository Service at National Institute of Oceanography (India)

Sanaye, S.V.; Pise, N.M.; Pawar, A.P.; Parab, P.P.; Sreepada, R.A.; Pawar, H.B.; Murugan, A.

-vitro antioxidant activities in terms of reducing power (RP), metal chelating activity (MCA), 2,2 diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, ferric reducing antioxidant power (FRAP), inhibition of lipid peroxidation (LPX) and hydroxyl radical...

The effect of ammonium ferric hexacyanoferrate on reducing radiocaesium transfer from grass silage to sheep

Directory of Open Access Journals (Sweden)

A. PAASIKALLIO

2008-12-01

Full Text Available A study was carried out to examine the effect of ammonium ferric hexacyanoferrate (AFCF on the transfer of radiocaesium from grass silage to the tissues of male lambs. During ensiling, a formic acid based additive and AFCF were sprayed on grass contaminated with 134Cs and the mixture was allowed to incubate for 45 days. A dose of 21 mg AFCF d-1, fed to sheep offered contaminated silage for fourteen days, reduced 134Cs transfer to muscle by 45% compared to that of control sheep. An equivalent dose of AFCF administered in a capsule reduced transfer by only 3%. In another experiment, AFCF intake of 50, 100 and 150 mg d-1 for ten days reduced 134Cs transfer to sheep muscle by 75, 82 and 86%, respectively. In control lambs, of average live weight 38 and 47 kg, the feed to muscle 134Cs transfer coefficient averaged 0.15 d kg-1, but equilibrium between tissue and feed 134Cs had probably not been reached due to the short feeding period. Increasing doses of AFCF from 0 to 150 mg d-1 increased the faecal/urinary 134Cs ratio from 2 to 42.;

Low-Cost and Rapid Fabrication of Metallic Nanostructures for Sensitive Biosensors Using Hot-Embossing and Dielectric-Heating Nanoimprint Methods

Directory of Open Access Journals (Sweden)

Kuang-Li Lee

2017-07-01

Full Text Available We propose two approaches—hot-embossing and dielectric-heating nanoimprinting methods—for low-cost and rapid fabrication of periodic nanostructures. Each nanofabrication process for the imprinted plastic nanostructures is completed within several seconds without the use of release agents and epoxy. Low-cost, large-area, and highly sensitive aluminum nanostructures on A4 size plastic films are fabricated by evaporating aluminum film on hot-embossing nanostructures. The narrowest bandwidth of the Fano resonance is only 2.7 nm in the visible light region. The periodic aluminum nanostructure achieves a figure of merit of 150, and an intensity sensitivity of 29,345%/RIU (refractive index unit. The rapid fabrication is also achieved by using radio-frequency (RF sensitive plastic films and a commercial RF welding machine. The dielectric-heating, using RF power, takes advantage of the rapid heating/cooling process and lower electric power consumption. The fabricated capped aluminum nanoslit array has a 5 nm Fano linewidth and 490.46 nm/RIU wavelength sensitivity. The biosensing capabilities of the metallic nanostructures are further verified by measuring antigen–antibody interactions using bovine serum albumin (BSA and anti-BSA. These rapid and high-throughput fabrication methods can benefit low-cost, highly sensitive biosensors and other sensing applications.

Rebalancing electrolytes in redox flow battery systems

Science.gov (United States)

Chang, On Kok; Pham, Ai Quoc

2014-12-23

Embodiments of redox flow battery rebalancing systems include a system for reacting an unbalanced flow battery electrolyte with a rebalance electrolyte in a first reaction cell. In some embodiments, the rebalance electrolyte may contain ferrous iron (Fe.sup.2+) which may be oxidized to ferric iron (Fe.sup.3+) in the first reaction cell. The reducing ability of the rebalance reactant may be restored in a second rebalance cell that is configured to reduce the ferric iron in the rebalance electrolyte back into ferrous iron through a reaction with metallic iron.

Long-term variations in sediment heavy metals of a reservoir with changing trophic states: Implications for the impact of climate change.

Science.gov (United States)

Wu, Qiong; Qi, Jun; Xia, Xinghui

2017-12-31

Two dated sediment cores from the Miyun Reservoir of Beijing in China were analyzed to reconstruct the pollution history of heavy metals including cadmium (Cd), chromium (Cr), iron (Fe), nickel (Ni), and zinc (Zn) as well as phosphorus (P). Enrichment factor (EF) and geoaccumulation index (I geo ) were applied to assess the enrichment status of heavy metals. Average EF and I geo values indicated that the studied heavy metals in the sediments mainly originated from non-point source pollution and soil-water erosion, showing low ecological risks. In addition, correlation analysis and principal component analysis (PCA) identified that Cd, Zn, and P were mainly from agricultural diffusion pollution caused by utilization of the phosphate fertilizer; Zn, Ni, and Cr originated from soil erosion. PCA analysis was further conducted to investigate the relationships among meteorological factors, algae-dominant total organic carbon (TOC), and heavy metals. Results showed that algae-dominant TOC had strong positive correlation with temperature, which can be explained by that increased temperature accelerated the growth of algae. Meanwhile the opposite loadings between algae-dominant TOC and heavy metal suggested that primary production played an important role in migration and transformation of metals. Moreover, stepwise multiple regression models showed that Fe was sensitive to temperature, which accounted for approximately 39.0% and 40.1% of the variations in Fe of two sediment cores, respectively. Fe showed significant decreasing trends during the past 50years. Reductive environment of water-sediment interface caused by increasing temperature probably contributed to the restoration of ferric iron, resulting in the release of soluble Fe to overlying waters. Future climate change with elevated temperature and extreme weather events will aggravate the ecological risk of heavy metals in water environment due to the enhanced leaching effect and non-point source pollution as well

Determination of metallic impurities in raw materials for radioisotope production by atomic absorption spectroscopy; Determinacion de trazas metalicas en amterias primas para la produccion de radioisotopos por espectroscopia de absorcion atomica

Energy Technology Data Exchange (ETDEWEB)

Roca, M; Alvarez, F; Capdevila, C

1969-07-01

Atomic absorption spectrometry has been used for the determination of traces of calcium in scandium oxide, copper in zinc, iron in cobalt oxide, manganese In ferric oxide, nickel in copper and zinc in gallium oxide. The influences on the sensitivities arising from the hollow cathode currents, the gas pressures and the acid concentrations have been considered. A study of the interferences from the metallic matrices has also been performed, the interference due to the absorption of the manganese radiation by the atoms of iron being the most outstanding . In order to remove the interfering elements and increase sensitivity, pre-concentration methods have been tested. The addition methods has also been used. (Author) 14 refs.

Extractive metallurgy. Recent advances

International Nuclear Information System (INIS)

Stevenson, E.J.

1977-01-01

Detailed technical information derived from patents issued since 1975 on extractive metallurgy is presented. In part one, concerning copper, the major areas covered are: smelting and roasting; acid leaching; ammonia leach processes; cuprous chloride and ferric chloride; and recovery of copper values from solution. Part two covers other metals, including: nickel and cobalt; ocean floor nodules; lead, zinc, molybdenum and manganese; precious metals; and uranium titanium, tantalum, rhenium, gallium, and other metals

RAAF Orion Aircraft A9-300 Oxygen Fire

Science.gov (United States)

1987-01-01

8217Tribochemical Effects in Technology III - Ignition of Metal Fires by Tribochemical Reactions’. Die Technick 24 Jg Heft 5 Mai (1969). 313. 7. MALONEY, K.M...to kinetic heating but to tribomechanically induced reactions. In a second series of experiments Heinicke and Harenz [Reference 6] showed that metal ... fires could be initiated by grinding metals and ferric oxide in a baii mill, pressurized with oxygen. The lag between the start of the grinding and

Formation of ferric iron crusts in Quaternary sediments of Lake Baikal, Russia, and implications for paleoclimate

Science.gov (United States)

Deike, R.G.; Granina, L.; Callender, E.; McGee, J.J.

1997-01-01

Phosphate-bearing, ferric iron and siliceous crusts ranging in age from Recent to approximately 65,000 yr B.P. are observed in sediments of Lake Baikal. In younger sediments the crusts are at the base of a spectrum of secondary iron and manganese oxides that accumulate near the sediment/water interface in the zone of positive oxidation potential beneath an oxygenated water column. In areas where the average Quaternary sedimentation rates have been slow (e.g. 0.026 mm/yr), the crusts are more common, and span a wider range of ages. No crusts have been found where the Quaternary sedimentation mode has been deltaic and rapid (0.15 mm/yr). Independent core correlation based on magnetic properties of the sediment suggests that crusts can be correlated over most of Academician Ridge, an area that is particularly sensitive to climatic events affecting the concentration of suspended sediment. These crusts may be indicative of periods of low suspended sediment concentration, which occur during sustained transitions from glacial periods of high detrital input, to interglacial periods of high diatom sedimentation. The crusts are dominated by iron-rich and siliceous amorphous mineral phases, with an FeO:SiO2 by weight of 3:1. Regardless of age or location in the lake the Fe phase always includes Ca, P and Mn. Extensive microprobe data for these four elements recast as normalized elemental weight percent reveal linear trends of Ca:P and Fe:P. With increasing P, Ca also increases such that the two elements maintain a linear relationship passing very close to the origin and with a mean molar Ca:P=0.3 (too low for well-characterized apatite). Conversely, with increasing P, Fe decreases (mean molar Fe:P=3.4). There is no correlation between Mn and P. Molar Fe:P ratios for vivianite (an Fe(II) phosphate mineral observed in sediments closely below some crusts) are clustered around a stoichiometric composition. The covariant increase in Ca:P and the corresponding decrease in Fe:P may

Characteristics and adaptability of iron- and sulfur-oxidizing microorganisms used for the recovery of metals from minerals and their concentrates

Directory of Open Access Journals (Sweden)

Rawlings Douglas E

2005-05-01

Full Text Available Abstract Microorganisms are used in large-scale heap or tank aeration processes for the commercial extraction of a variety of metals from their ores or concentrates. These include copper, cobalt, gold and, in the past, uranium. The metal solubilization processes are considered to be largely chemical with the microorganisms providing the chemicals and the space (exopolysaccharide layer where the mineral dissolution reactions occur. Temperatures at which these processes are carried out can vary from ambient to 80°C and the types of organisms present depends to a large extent on the process temperature used. Irrespective of the operation temperature, biomining microbes have several characteristics in common. One shared characteristic is their ability to produce the ferric iron and sulfuric acid required to degrade the mineral and facilitate metal recovery. Other characteristics are their ability to grow autotrophically, their acid-tolerance and their inherent metal resistance or ability to acquire metal resistance. Although the microorganisms that drive the process have the above properties in common, biomining microbes usually occur in consortia in which cross-feeding may occur such that a combination of microbes including some with heterotrophic tendencies may contribute to the efficiency of the process. The remarkable adaptability of these organisms is assisted by several of the processes being continuous-flow systems that enable the continual selection of microorganisms that are more efficient at mineral degradation. Adaptability is also assisted by the processes being open and non-sterile thereby permitting new organisms to enter. This openness allows for the possibility of new genes that improve cell fitness to be selected from the horizontal gene pool. Characteristics that biomining microorganisms have in common and examples of their remarkable adaptability are described.

Relative bioavailability of micronized, dispersible ferric pyrophosphate added to an apple juice drink.

Science.gov (United States)

Roe, Mark A; Collings, Rachel; Hoogewerff, Jurian; Fairweather-Tait, Susan J

2009-03-01

Food iron fortification is a sustainable and relatively simple strategy to reduce/prevent iron deficiency but is a challenge for the food industry because of possible adverse organoleptic changes caused by the added iron. A micronized dispersible ferric pyrophosphate, trademarked as SunActive Fe, has recently been developed. SunActive Fe has a small particle size, is water soluble and may be suitable for fortifying liquid products. To determine the relative bioavailability of SunActive Fe and its suitability for addition to pure apple juice. Iron absorption from SunActive Fe added to pure apple juice (Minute Maid) was compared with absorption from ferrous sulphate, a highly bioavailable form of iron, in 15 women with relatively low iron stores. Both forms of iron were enriched with an iron stable isotope and iron absorption from the apple juice drinks was calculated from the isotopic enrichment of red blood cells 14 days after the last test meal. Although mean absorption of iron from SunActive Fe was significantly lower than from ferrous sulphate (5.5% compared with 9.1%), the mean bioavailability of SunActive Fe iron relative to ferrous sulphate was 0.6, indicating that it is a good source of bioavailable iron. Iron Absorption from SunActive Fe was positively correlated (r = 0.97, P = 0.01) with absorption from ferrous sulphate, and negatively correlated with serum ferritin concentration (ferrous sulphate r = -0.81, P apple juice and is a potentially useful fortificant for liquid food products.

Multiconfigurational and DFT analyses of the electromeric formulation and UV-vis absorption spectra of the superoxide adduct of ferrous superoxide reductase.

Science.gov (United States)

Attia, Amr A A; Cioloboc, Daniela; Lupan, Alexandru; Silaghi-Dumitrescu, Radu

2016-12-01

The putative initial adduct of ferrous superoxide reductase (SOR) with superoxide has been alternatively formulated as ferric-peroxo or ferrous-superoxo. The ~600-nm UV-vis absorption band proposed to be assigned to this adduct (either as sole intermediate in the SOR catalytic cycle, or as one of the two intermediates) has recently been interpreted as due to a ligand-to-metal charge transfer, involving thiolate and superoxide in a ferrous complex, contrary to an alternative assignment as a predominantly cysteine thiolate-to-ferric charge transfer in a ferric-peroxo electromer. In an attempt to clarify the electromeric formulation of this adduct, we report a computational study using a multiconfigurational complete active space self-consistent field (MC-CASSCF) wave function approach as well as modelling the UV-vis absorption spectra with time-dependent density functional theory (TD-DFT). The MC-CASSCF calculations disclose a weak interaction between iron and the dioxygenic ligand and a dominant configuration with an essentially ferrous-superoxo character. The computed UV-vis absorption spectra reveal a marked dependence on the choice of density functional - both in terms of location of bands and in terms of orbital contributors. For the main band in the visible region, besides the recently reported thiolate-to-superoxide charge transfer, a more salient, and less functional-dependent, feature is a thiolate-to-ferric iron charge transfer, consistent with a ferric-peroxo electromer. By contrast, the computed UV-vis spectra of a ferric-hydroperoxo SOR model match distinctly better (and with no qualitative dependence on the DFT methodology) the 600-nm band as due to a mainly thiolate-to-ferric character - supporting the assignment of the SOR "600-nm intermediate" as a S=5/2 ferric-hydroperoxo species. Copyright © 2016 Elsevier Inc. All rights reserved.

Arsenic Removal from Water Using Various Adsorbents: Magnetic Ion Exchange Resins, Hydrous Ion Oxide Particles, Granular Ferric Hydroxide, Activated Alumina, Sulfur Modified Iron, and Iron Oxide-Coated Microsand

KAUST Repository

Sinha, Shahnawaz

2011-09-30

The equilibrium and kinetic adsorption of arsenic on six different adsorbents were investigated with one synthetic and four natural types (two surface and two ground) of water. The adsorbents tested included magnetic ion exchange resins (MIEX), hydrous ion oxide particles (HIOPs), granular ferric hydroxide (GFH), activated alumina (AA), sulfur modified iron (SMI), and iron oxide-coated mic - rosand (IOC-M), which have different physicochemical properties (shape, charge, surface area, size, and metal content). The results showed that adsorption equilibriums were achieved within a contact period of 20 min. The optimal doses of adsorbents determined for a given equilibrium concentration of C eq = 10 μg/L were 500 mg/L for AA and GFH, 520–1,300 mg/L for MIEX, 1,200 mg/L for HIOPs, 2,500 mg/L for SMI, and 7,500 mg/L for IOC-M at a contact time of 60 min. At these optimal doses, the rate constants of the adsorbents were 3.9, 2.6, 2.5, 1.9, 1.8, and 1.6 1/hr for HIOPs, AA, GFH, MIEX, SMI, and IOC-M, respectively. The presence of silicate significantly reduced the arsenic removal efficiency of HIOPs, AA, and GFH, presumably due to the decrease in chemical binding affinity of arsenic in the presence of silicate. Additional experiments with natural types of water showed that, with the exception of IOC-M, the adsorbents had lower adsorption capacities in ground water than with surface and deionized water, in which the adsorption capacities decreased by approximately 60–95 % .

Dissolution behaviour of ferric pyrophosphate and its mixtures with soluble pyrophosphates: Potential strategy for increasing iron bioavailability.

Science.gov (United States)

Tian, Tian; Blanco, Elena; Smoukov, Stoyan K; Velev, Orlin D; Velikov, Krassimir P

2016-10-01

Ferric pyrophosphate (FePP) is a widely used iron source in food fortification and in nutritional supplements, due to its white colour, that is very uncommon for insoluble Fe salts. Although its dissolution is an important determinant of Fe adsorption in human body, the solubility characteristics of FePP are complex and not well understood. This report is a study on the solubility of FePP as a function of pH and excess of pyrophosphate ions. FePP powder is sparingly soluble in the pH range of 3-6 but slightly soluble at pH8. In the presence of pyrophosphate ions the solubility of FePP strongly increases at pH 5-8.5 due to formation a soluble complex between Fe(III) and pyrophosphate ions, which leads to an 8-10-fold increase in the total ionic iron concentration. This finding is beneficial for enhancing iron bioavailability, which important for the design of fortified food, beverages, and nutraceutical products. Copyright © 2016 Elsevier Ltd. All rights reserved.

An experimental study on accelerated fouling of aluminum oxide and ferric oxide particles in internally enhanced tubes

Energy Technology Data Exchange (ETDEWEB)

Abedin, Mohammad Zoynal; Kim, Nae Hyun [School of Mechanical System Engineering, Incheon National University, Incheon (Korea, Republic of)

2016-12-15

This paper describes the results of accelerated particulate fouling tests performed on three enhanced tubes and a plain tube. The tests were performed using ferric oxide and aluminum oxide as foulant materials. Three enhanced tubes included 25 start, 10 start helically ribbed tubes and a ripple tube. Effects of the water velocity (0.9 to 1.8 m/s) and foulant concentration (750 to 2500 ppm) were investigated. At 750 ppm, the enhanced tubes fouled almost the same as the plain tube for the entire velocity range tested (0.9 to 1.8 m/s). The enhanced tube fouled faster than the plain tube for cases of high concentration combined with low velocities. Of the three enhanced tubes, the 25 start helically ribbed tube fouled faster than the ripple and the 10 start helically ribbed tubes. One thing to be noted is that the fouling concentrations used in the tests are significantly higher than would be expected in commercial heat exchangers. Also, the velocity range investigated is lower than would be expected in heat exchanger operation.

Kinetic study of the reduction of Ferric-1, 10-Orthophenanthroline with Uranium (IV) DTPA

International Nuclear Information System (INIS)

Perveen, Rashida; Naqvi, Iftikhar Imam

2006-01-01

The reduction of ferric 1, 10-orthophenanthroline by Uranium (IV) complex of Diethylenetriaminepentaacetic acid was investigated in aqueous hydrochloride acid at 30C, ionic strength 0.01 mole dm-3 and pH 3.5. The mechanism and rate law for the formation of [Fe (opt) 3] was established by isolation method at constant and varying pH values. Spectroscopic method was employed for this investigation. The rate constant and order of reaction with respect to each of the reactant the [U (IV) DTPA] and [Fe(opt3)] was established by plotting a graph 1n (A-At) vs. time. The reaction was observed to be following first order with respect each of following reactants. Overall reaction order was found to be two, having the value of the rate constant 571.59 m min. at pH 3.5. Thermodynamic parameters for the reaction were determined to be E=26.47 kj mol, G=35.11 kj mol, H=24.86 mol and S= 50.17 mol. With the help of Arrhenius equation activation energy for the reaction was calculated. Change in enthalpy and entropy for the reaction (S, H) were determined from the slope and intercept of Eyring plot. Hydrogen ion dependence of the reaction was determined by varying the pH and the rate law was determined. (author)

Comparison of the Performance of Corn Starch Coagulant Aid Accompany with Alum, Polyaluminum Chloride and Ferric Chloride Coagulants in Turbidity Removal from Water

Directory of Open Access Journals (Sweden)

Leila Mosleh

2014-09-01

Full Text Available Background: The most important process in water treatment plant is coagulation and flocculation. Regular chemical coagulant which used in Iran are aluminum sulfate (Alum and ferric chloride. Chemical coagulants have hazardous effect on human health and their cost is high for developing country. The purpose of this study was to evaluate the comparison of chemical coagulants accompany with corn starch as a coagulant aid, for the turbidity removal from water. Methods: This study was accomplished in pilot-scale with synthetic turbid water using clay. In this research, initial turbidity of 250 and 500 NTU was experimented. Chemical coagulant dose during the experiment was 1, 2 and 5 ppm and natural coagulant dose was 0, 0.1, 0.3, 0.5 and 0.7 ppm. Results: The results showed that maximum removal efficiency of turbidity in initial turbidity of 250 NTU belonged to poly aluminum chloride with 5 ppm dosage and corn starch with 0.7 ppm dosage which removed and reduced the initial turbidity to 98.48% and 3.73 NTU, respectively. Moreover, in initial turbidity of 500 NTU the maximum removal efficiency was 98.52% which belonged to ferric chloride and corn starch (5 and 0.7 ppm respectively and reduced the initial turbidity to 7.4 NTU. Conclusions: The results of this study showed that using natural coagulant aid reduce the chemical coagulant consumption, and also does not have significant effect on pH range and reduce the health risks. While huge amount of required polyelectrolytes for water treatment plant imported to the country and the production of corn starch in our country is high, it is hope that the results of this project can be used in industrial scale.

Indirect spectrophotometric determination of arbutin, whitening agent through oxidation by periodate and complexation with ferric chloride

Science.gov (United States)

Barsoom, B. N.; Abdelsamad, A. M. E.; Adib, N. M.

2006-07-01

A simple and accurate spectrophotometric method for the determination of arbutin (glycosylated hydroquinone) is described. It is based on the oxidation of arbutin by periodate in presence of iodate. Excess periodate causes liberation of iodine at pH 8.0. The unreacted periodate is determined by measurement of the liberated iodine spectrophotometrically in the wavelength range (300-500 nm). A calibration curve was constructed for more accurate results and the correlation coefficient of linear regression analysis was -0.9778. The precision of this method was better than 6.17% R.S.D. ( n = 3). Regression analysis of Bear-Lambert plot shows good correlation in the concentration range 25-125 ug/ml. The identification limit was determined to be 25 ug/ml a detailed study of the reaction conditions was carried out, including effect of changing pH, time, temperature and volume of periodate. Analyzing pure and authentic samples containing arbutin tested the validity of the proposed method which has an average percent recovery of 100.86%. An alternative method is also proposed which involves a complexation reaction between arbutin and ferric chloride solution. The produced complex which is yellowish-green in color was determined spectophotometrically.

Solar Ultraviolet-B Radiation Increases Phenolic Content and Ferric Reducing Antioxidant Power in Avena sativa

Directory of Open Access Journals (Sweden)

Christopher T. Ruhland

2007-06-01

Full Text Available We examined the influence of solar ultraviolet-B radiation (UV-B; 280-320 nm on the maximum photochemical efficiency of photosystem II (Fv/Fm, bulk-soluble phenolic concentrations, ferric-reducing antioxidant power (FRAP and growth of Avena sativa. Treatments involved placing filters on frames over potted plants that reduced levels of biologically effective UV-B by either 71% (reduced UV-B or by 19% (near-ambient UV-B over the 52 day experiment (04 July - 25 August 2002. Plants growing under near-ambient UV-B had 38% less total biomass than those under reduced UV-B. The reduction in biomass was mainly the result of a 24% lower leaf elongation rate, resulting in shorter leaves and less total leaf area than plants under reduced UV-B. In addition, plants growing under near-ambient UV-B had up to 17% lower Fv/Fm values early in the experiment, and this effect declined with plant age. Concentrations of bulk-soluble phenolics and FRAP values were 17 and 24% higher under near-ambient UV-B than under reduced UV-B, respectively. There was a positive relationship between bulk-soluble phenolic concentrations and FRAP values. There were no UV-B effects on concentrations of carotenoids (carotenes + xanthophylls.

Formation, reactivity and aging of amorphous ferric oxides in the presence of model and membrane bioreactor derived organics.

Science.gov (United States)

Bligh, Mark W; Maheshwari, Pradeep; David Waite, T

2017-11-01

Iron salts are routinely dosed in wastewater treatment as a means of achieving effluent phosphorous concentration goals. The iron oxides that result from addition of iron salts partake in various reactions, including reductive dissolution and phosphate adsorption. The reactivity of these oxides is controlled by the conditions of formation and the processes, such as aggregation, that lead to a reduction in accessible surface sites following formation. The presence of organic compounds is expected to significantly impact these processes in a number of ways. In this study, amorphous ferric oxide (AFO) reactivity and aging was investigated following the addition of ferric iron (Fe(III)) to three solution systems: two synthetic buffered systems, either containing no organic or containing alginate, and a supernatant system containing soluble microbial products (SMPs) sourced from a membrane bioreactor (MBR). Reactivity of the Fe(III) phases in these systems at various times (1-60 min) following Fe(III) addition was quantified by determining the rate constants for ascorbate-mediated reductive dissolution over short (5 min) and long (60 min) dissolution periods and for a range (0.5-10 mM) of ascorbate concentrations. AFO particle size was monitored using dynamic light scattering during the aging and dissolution periods. In the presence of alginate, AFO particles appeared to be stabilized against aggregation. However, aging in the alginate system was remarkably similar to the inorganic system where aging is associated with aggregation. An aging mechanism involving restructuring within the alginate-AFO assemblage was proposed. In the presence of SMPs, a greater diversity of Fe(III) phases was evident with both a small labile pool of organically complexed Fe(III) and a polydisperse population of stabilized AFO particles present. The prevalence of low molecular weight organic molecules facilitated stabilization of the Fe(III) oxyhydroxides formed but subsequent aging

Metals, heavy metals and microorganism removal from spent filter backwash water by hybrid coagulation-UF processes

Directory of Open Access Journals (Sweden)

Mokhtar Mahdavi

2018-04-01

Full Text Available Spent filter backwash water (SFBW reuse has attracted particular attention, especially in countries that experience water scarcity. It can act as a permanent water source until the water treatment plant is working. In this study, the concentrations of Fe, Al, Pb, As, and Cd with total and fecal coliform (TC/FC were investigated in raw and treated SFBW by hybrid coagulation-UF processes. The pilot plant consisted of pre-sedimentation, coagulation, flocculation, clarification, and ultrafiltration (UF units. Poly-aluminum ferric chloride (PAFCL and ferric chloride (FeCl3 were used as pretreatment. The results showed that, at the optimum dose of PAFCl, the average removal of TC and FC was 88 and 79% and with PAFCl-UF process, it reached 100 and 100%, respectively. For FeCl3, removal efficiency of TC and FC were 81 and 72% and by applying FeCl3-UF process, it reached 100 and 100%, respectively. In comparison with FeCl3, PAFCl showed better removal efficiency for Fe, Pb, As, and Cd, except residual Al concentration. Coagulation-UF process could treat SFBW efficiently and treated SFBW could meet the US-EPA drinking water standard. Health risk index values of Fe, AL, Pb, AS, and Cd in treated SFBW indicate no risk of exposure to the use of this water.

Cryo magnetic separation adaptation to environment technologies: application to industrial effluents; Adaptation de la separation cryomagnetique aux technologies de l`environnement: application a l`epuration d`effluents liquides industriels

Energy Technology Data Exchange (ETDEWEB)

Bureau, V

1993-12-20

Cryomagnetic separation adaptation to environment technologies application to industrial liquid effluents. The performance, obtained by superconducting high filed - high gradient magnetic separation, permitted to foresee the magnetic treatment of heavy metals in rinse waters, derived from the surface finishing industry. The paramagnetic ions, precipitated in basic media as hydroxides, present a very hydrated amorphous structure, which masks their subjacent magnetic properties. Coprecipitation of a `magnetic carrier`, jointly with the heavy metals, has been studied: ferric chloride forms in basic media, an hydrated iron oxide. Its structure is of the goethite type, and it stabilizes as hematite. The magnetic susceptibility of the obtained product is still weak and its crystalline structure is not enough affirmative to utilize magnetic filtration with efficiency. Mixture of ferrous sulphate and ferric chloride forms, in a basic media, an hydrated magnetite. Initial ideal ratio between divalent iron and trivalent iron, varies between 0,5 and 1,2. This mixture, coprecipitated with the heavy metals, permits to optimize the magnetic cleaning of the fluids in a high field - high gradient filter. (author)

Simulation of ferric ions transfer in dosemeter Fricke-Xylenol-Gel in means no homogeneous; Simulacao da difusao de ions ferricos em dosimetros Fricke-Xilenol-Gel em meios nao homogeneos

Energy Technology Data Exchange (ETDEWEB)

Milani, Caio J.; Bevilacqua, Joyce da Silva, E-mail: caio.milani@usp.br, E-mail: joyce@ime.usp.br [Universidade de Sao Paulo (USP), SP (Brazil). Instituto de Matematica e Estatistica. Departamento de Matematica Aplicada; Cavinato, Christianne C.; Rodrigues Junior, Orlando; Campos, Leticia L., E-mail: rodrijr@ipen.br, E-mail: Icrodri@ipen.br, E-mail: ccavinato@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (lPEN/CNEN-SP), Sao Paulo, SP (Brazil). Gerencia de Metrologia das Radiacoes

2013-11-01

Dosimetry in three dimensions using Fricke-Xilenol-Gel dosimeters (FXG) allows the confirmation and a better understanding of a treatment by Radiotherapy. The technique involves the assessment of the irradiated volumes by magnetic resonance imaging (MRI) or optical-CT. On both cases, the time elapsed between the irradiation and the measurement is an important factor in the quality of results. The quality of the images can be compromised by the mobility of the ferric ions (Fe{sup 3+}), formed during the the interaction of the radiation with the matter, increasing the uncertainty in the determination of the isodoses in the volume. In this work, the phenomenon of the diffusion of the ferric ions formed by an irradiated region is simulated in a bidimensional domain. The dynamic of the Fe{sup 3+} in Fricke-Gel is modeled by a parabolic partial differential equation and solved by the ADI-Peaceman-Rachford algorithm. Stability and consistency of the method guarantee the convergence of the numerical solution for a pre-defined error magnitude, based on choices for the discretization values of time and space. Homogeneous and non-homogeneous cases are presented considering an irradiated region and a physical barrier that prevents the movement of the ions, on the non-homogeneous case. Graphical visualizations of the phenomenon are presented for better understanding of the process. (author)

Cofortification of ferric pyrophosphate and citric acid/trisodium citrate into extruded rice grains doubles iron bioavailability through in situ generation of soluble ferric pyrophosphate citrate complexes.

Science.gov (United States)

Hackl, Laura; Cercamondi, Colin I; Zeder, Christophe; Wild, Daniela; Adelmann, Horst; Zimmermann, Michael B; Moretti, Diego

2016-05-01

Iron fortification of rice is a promising strategy for improving iron nutrition. However, it is technically challenging because rice is consumed as intact grains, and ferric pyrophosphate (FePP), which is usually used for rice fortification, has low bioavailability. We investigated whether the addition of a citric acid/trisodium citrate (CA/TSC) mixture before extrusion increases iron absorption in humans from FePP-fortified extruded rice grains. We conducted an iron absorption study in iron-sufficient young women (n = 20), in which each participant consumed 4 different meals (4 mg Fe/meal): 1) extruded FePP-fortified rice (No CA/TSC); 2) extruded FePP-fortified rice with CA/TSC added before extrusion (CA/TSC extruded); 3) extruded FePP-fortified rice with CA/TSC solution added after cooking and before consumption (CA/TSC solution); and 4) nonextruded rice fortified with a FeSO4 solution added after cooking and before consumption (reference). Iron absorption was calculated from erythrocyte incorporation of stable iron isotopes 14 d after administration. In in vitro experiments, we assessed the soluble and dialyzable iron from rice meals in which CA/TSC was added at different preparation stages and from meals with different iron:CA:TSC ratios. Fractional iron absorption was significantly higher from CA/TSC-extruded meals (3.2%) than from No CA/TSC (1.7%) and CA/TSC solution (1.7%; all P solubility and dialyzability were higher in CA/TSC-extruded rice than in rice with No CA/TSC and CA/TSC solution, and solubility increased with higher amounts of added CA and TSC in extruded rice. Iron bioavailability nearly doubled when CA/TSC was extruded with FePP into fortified rice, resulting in iron bioavailability comparable to that of FeSO4 We attribute this effect to an in situ generation of soluble FePP citrate moieties during extrusion and/or cooking because of the close physical proximity of FePP and CA/TSC in the extruded rice matrix. This trial was registered at

Metals Recovery from Acid Mine Drainage and Possibilities for their Utilization

Czech Academy of Sciences Publication Activity Database

Michalková, E.; Schwarz, M.; Pulišová, Petra; Máša, B.; Sudovský, P.

2013-01-01

Roč. 22, č. 4 (2013), s. 1111-1118 ISSN 1230-1485 R&D Projects: GA MŠk 7AMB12SK155 Institutional support: RVO:61388980 Keywords : acid mine drainage * ferric pigments * adsorbent Subject RIV: CA - Inorganic Chemistry Impact factor: 0.600, year: 2013

The aqueous solubility of ofloxacin in the presence of metallic cations

African Journals Online (AJOL)

Ferrous sulphate produced the greatest increase in the solubility of ofloxacin. It was followed by ferric ammonium citrate, magnesium sulphate, aluminium hydroxide and calcium carbonate. Potassium chloride and sodium bicarbonate produced very slight increases. In all the cases, the solubility of ofloxacin increased as the ...

The passivation of calcite by acid mine water. Column experiments with ferric sulfate and ferric chloride solutions at pH 2

Energy Technology Data Exchange (ETDEWEB)

Soler, Josep M. [Institute of Earth Sciences ' Jaume Almera' (CSIC), Lluis Sole i Sabaris s/n, 08028 Barcelona, Catalonia (Spain); Institute of Environmental Assessment and Water Research (CSIC), Jordi Girona 18, 08034 Barcelona, Catalonia (Spain)], E-mail: jsoler@ija.csic.es; Boi, Marco [Institute of Earth Sciences ' Jaume Almera' (CSIC), Lluis Sole i Sabaris s/n, 08028 Barcelona, Catalonia (Spain); Institute of Environmental Assessment and Water Research (CSIC), Jordi Girona 18, 08034 Barcelona, Catalonia (Spain); Mogollon, Jose Luis [Institute of Earth Sciences ' Jaume Almera' (CSIC), Lluis Sole i Sabaris s/n, 08028 Barcelona, Catalonia (Spain); Instituto de Ciencias de la Tierra, Universidad Central de Venezuela, Caracas 1020-A (Venezuela, Bolivarian Republic of); Cama, Jordi; Ayora, Carlos [Institute of Earth Sciences ' Jaume Almera' (CSIC), Lluis Sole i Sabaris s/n, 08028 Barcelona, Catalonia (Spain); Institute of Environmental Assessment and Water Research (CSIC), Jordi Girona 18, 08034 Barcelona, Catalonia (Spain); Nico, Peter S.; Tamura, Nobumichi; Kunz, Martin [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States)

2008-12-15

Column experiments, simulating the behavior of passive treatment systems for acid mine drainage, have been performed. Acid solutions (HCl or H{sub 2}SO{sub 4}, pH 2), with initial concentrations of Fe(III) ranging from 250 to 1500 mg L{sup -1}, were injected into column reactors packed with calcite grains at a constant flow rate. The composition of the solutions was monitored during the experiments. At the end of the experiments (passivation of the columns), the composition and structure of the solids were measured. The dissolution of calcite in the columns caused an increase in pH and the release of Ca into the solution, leading to the precipitation of gypsum and Fe-oxyhydroxysulfates (Fe(III)-SO{sub 4}-H{sup +} solutions) or Fe-oxyhydroxychlorides (Fe(III)-Cl-H{sup +} solutions). The columns worked as an efficient barrier for some time, increasing the pH of the circulating solutions from 2 to {approx}6-7 and removing its metal content. However, after some time (several weeks, depending on the conditions), the columns became chemically inert. The results showed that passivation time increased with decreasing anion and metal content of the solutions. Gypsum was the phase responsible for the passivation of calcite in the experiments with Fe(III)-SO{sub 4}-H{sup +} solutions. Schwertmannite and goethite appeared as the Fe(III) secondary phases in those experiments. Akaganeite was the phase responsible for the passivation of the system in the experiments with Fe(III)-Cl-H{sup +} solutions.

Acid-curing and ferric-trickle leaching effluent used in closed circuit uranium extractive process

International Nuclear Information System (INIS)

Jin Suoqing; Xiang Qinfang; Guo Jianzheng; Lu Guizhu; Su Yanru

1998-01-01

The new uranium ore process consists of crushing ore, mixing crushed ore with strong acid in rotating drums and curing the mixture in piles, trickle-leaching the ore beds with ferric solution, extracting uranium from pregnant solution with tertiary amine, precipitating product and disposing residue tailings. All the process effluent is used in closed circuit. There will be no process water to be discharged in the flowsheet except the tailings carrying off 15% water because during leaching moisture content of the ore rises to 15%. Tailings produced by the process are moist and friable, and can be disposed of on a pile or returned to the mine. Main technical parameters of the process: (a) water consumption is 0.2∼0.3 m 3 /t ore, electric power consumption is 20∼30 kW·h/t ore; (b) ore crushing up to -5∼-7 mm, leaching period is 12∼45 d, U content of residue is 0.01%∼0.02%, producing pregnant solution is 0.3∼0.5 m 3 /t ore, which is 1/5∼1/8 that of conventional agitation leaching process; (c) organic agent consumption is 1/5∼1/8 that of the conventional agitation process. All the research results above are tested by the pilot-plant test and industrial test. The new process has been applied to recovery of uranium in the mine located at northeast of China

Sodium pyrophosphate enhances iron bioavailability from bouillon cubes fortified with ferric pyrophosphate.

Science.gov (United States)

Cercamondi, Colin I; Duchateau, Guus S M J E; Harika, Rajwinder K; van den Berg, Robin; Murray, Peter; Koppenol, Wieneke P; Zeder, Christophe; Zimmermann, Michael B; Moretti, Diego

2016-08-01

Fe fortification of centrally manufactured and frequently consumed condiments such as bouillon cubes could help prevent Fe deficiency in developing countries. However, Fe compounds that do not cause sensory changes in the fortified product, such as ferric pyrophosphate (FePP), exhibit low absorption in humans. Tetra sodium pyrophosphate (NaPP) can form soluble complexes with Fe, which could increase Fe bioavailability. Therefore, the aim of this study was to investigate Fe bioavailability from bouillon cubes fortified with either FePP only, FePP+NaPP, ferrous sulphate (FeSO4) only, or FeSO4+NaPP. We first conducted in vitro studies using a protocol of simulated digestion to assess the dialysable and ionic Fe, and the cellular ferritin response in a Caco-2 cell model. Second, Fe absorption from bouillon prepared from intrinsically labelled cubes (2·5 mg stable Fe isotopes/cube) was assessed in twenty-four Fe-deficient women, by measuring Fe incorporation into erythrocytes 2 weeks after consumption. Fe bioavailability in humans increased by 46 % (P<0·005) when comparing bouillons fortified with FePP only (4·4 %) and bouillons fortified with FePP+NaPP (6·4 %). Fe absorption from bouillons fortified with FeSO4 only and with FeSO4+NaPP was 33·8 and 27·8 %, respectively (NS). The outcome from the human study is in agreement with the dialysable Fe from the in vitro experiments. Our findings suggest that the addition of NaPP could be a promising strategy to increase Fe absorption from FePP-fortified bouillon cubes, and if confirmed by further research, for other fortified foods with complex food matrices as well.

Effect of soil amendments and crop varieties on the amelioration of heavy metal uptake into crops grown on polluted soils of Bangladesh

International Nuclear Information System (INIS)

Chamon, A.S.

2000-11-01

Bangladesh possesses many industrial sites, whereby wastes and effluents are directly discharged into the environment without any treatment. Agricultural areas are contaminated thereby and the food quality is impaired. Therefore, the aim of the present work was to develop simple and cost effective strategies to reduce soil-plant transfer of harmful substances. Three sites were selected in the vicinity of Dhaka city (Tongi pharmaceutical, Tejgaon industrial and Hazaribagh tannery area). Field and pot experiments were carried out with different varieties of field crops (rice, wheat and tomato) and different soil amendments (cowdung, city waste compost, oil cake, waterhyacinth, poultry litter, lime and red mud). At the site Tongi, pollutants mainly consists of organic compounds. The soil of Tejgaon is acidic (pH=5.7), contains high organic matter and elevated concentrations of Zn (685 mg/kg), Pb (136 mg/kg), and Cd (2.6 mg/kg). The Hazaribagh region is polluted by a highly elevated concentration of heavy metals, especially Cr (11000 mg/kg). The amendment by organic residues significantly improved harvested rice yield as well as the contents of heavy metals were partly reduced on Tongi soil. The different varieties of rice and wheat showed distinct differences in biomass yield and in heavy metal accumulation on three soils. The positive effect of lime application in reducing metal uptake by rice, wheat and tomato plants were observed on both Tejgaon and Hazaribagh soil, compared to the control. Red mud (ferric oxide) applied in small amounts, on Tejgaon and Hazaribagh soil, led to an increase in biomass production and improved yield for rice plants and to significant reductions of soil plant transfer for Zn, Ni, Cd and Cr. (author)

Resistless Fabrication of Nanoimprint Lithography (NIL Stamps Using Nano-Stencil Lithography

Directory of Open Access Journals (Sweden)

Juergen Brugger

2013-10-01

Full Text Available In order to keep up with the advances in nano-fabrication, alternative, cost-efficient lithography techniques need to be implemented. Two of the most promising are nanoimprint lithography (NIL and stencil lithography. We explore here the possibility of fabricating the stamp using stencil lithography, which has the potential for a cost reduction in some fabrication facilities. We show that the stamps reproduce the membrane aperture patterns within ±10 nm and we validate such stamps by using them to fabricate metallic nanowires down to 100 nm in size.

AMOEBA Polarizable Force Field Parameters of the Heme Cofactor in Its Ferrous and Ferric Forms.

Science.gov (United States)

Wu, Xiaojing; Clavaguera, Carine; Lagardère, Louis; Piquemal, Jean-Philip; de la Lande, Aurélien

2018-04-16

We report the first parameters of the heme redox cofactors for the polarizable AMOEBA force field in both the ferric and ferrous forms. We consider two types of complexes, one with two histidine side chains as axial ligands and one with a histidine and a methionine side chain as ligands. We have derived permanent multipoles from second-order Møller-Plesset perturbation theory (MP2). The sets of parameters have been validated in a first step by comparison of AMOEBA interaction energies of heme and a collection of biologically relevant molecules with MP2 and Density Functional Theory (DFT) calculations. In a second validation step, we consider interaction energies with large aggregates comprising around 80 H 2 O molecules. These calculations are repeated for 30 structures extracted from semiempirical PM7 DM simulations. Very encouraging agreement is found between DFT and the AMOEBA force field, which results from an accurate treatment of electrostatic interactions. We finally report long (10 ns) MD simulations of cytochromes in two redox states with AMOEBA testing both the 2003 and 2014 AMOEBA water models. These simulations have been carried out with the TINKER-HP (High Performance) program. In conclusion, owing to their ubiquity in biology, we think the present work opens a wide array of applications of the polarizable AMOEBA force field on hemeproteins.

Effects of molecular composition of natural organic matter on ferric iron complexation at circumneutral pH.

Science.gov (United States)

Fujii, Manabu; Imaoka, Akira; Yoshimura, Chihiro; Waite, T D

2014-04-15

Thermodynamic and kinetic parameters for ferric iron (Fe[III]) complexation by well-characterized humic substances (HS) from various origins were determined by a competitive ligand method with 5-sulfosalicylic acid at circumneutral pH (6.0-8.0) and an ionic strength of ∼0.06 M. The measured Fe binding properties including conditional stability constants and complexation capacities ranged over more than 2 orders of magnitude, depending on the origin and the particular operationally defined fraction of HS examined. Statistical comparison of the complexation parameters to a range of chemical properties of the HS indicated a strong positive correlation between Fe(III) complexation capacity and aromatic carbon content in the HS at all pHs examined. In contrast, the complexation capacity was determined to be up to a few orders of magnitude smaller than the concentration of carboxylic and phenolic groups present. Therefore, specific functional groups including those resident in the proximity of aromatic structures within the HS are likely preferable for Fe(III) coordination under the conditions examined. Overall, our results suggest that the concentration of dissolved Fe(III) complexes in natural waters is substantially influenced by variation in HS characteristics in addition to other well-known factors such as HS concentration and nature and concentration of competing cations present.

Coagulant recovery and reuse for drinking water treatment.

Science.gov (United States)

Keeley, James; Jarvis, Peter; Smith, Andrea D; Judd, Simon J

2016-01-01

Coagulant recovery and reuse from waterworks sludge has the potential to significantly reduce waste disposal and chemicals usage for water treatment. Drinking water regulations demand purification of recovered coagulant before they can be safely reused, due to the risk of disinfection by-product precursors being recovered from waterworks sludge alongside coagulant metals. While several full-scale separation technologies have proven effective for coagulant purification, none have matched virgin coagulant treatment performance. This study examines the individual and successive separation performance of several novel and existing ferric coagulant recovery purification technologies to attain virgin coagulant purity levels. The new suggested approach of alkali extraction of dissolved organic compounds (DOC) from waterworks sludge prior to acidic solubilisation of ferric coagulants provided the same 14:1 selectivity ratio (874 mg/L Fe vs. 61 mg/L DOC) to the more established size separation using ultrafiltration (1285 mg/L Fe vs. 91 mg/L DOC). Cation exchange Donnan membranes were also examined: while highly selective (2555 mg/L Fe vs. 29 mg/L DOC, 88:1 selectivity), the low pH of the recovered ferric solution impaired subsequent treatment performance. The application of powdered activated carbon (PAC) to ultrafiltration or alkali pre-treated sludge, dosed at 80 mg/mg DOC, reduced recovered ferric DOC contamination to water quality parameters. Several PAC-polished recovered coagulants provided the same or improved DOC and turbidity removal as virgin coagulant, as well as demonstrating the potential to reduce disinfection byproducts and regulated metals to levels comparable to that attained from virgin material. Copyright © 2015 Elsevier Ltd. All rights reserved.

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

Directory of Open Access Journals (Sweden)

Daniel Kupka

2004-12-01

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

Stimulation of NADH-dependent microsomal DNA strand cleavage by rifamycin SV.

Science.gov (United States)

Kukiełka, E; Cederbaum, A I

1995-04-15

Rifamycin SV is an antibiotic anti-bacterial agent used in the treatment of tuberculosis. This drug can autoxidize, especially in the presence of metals, and generate reactive oxygen species. A previous study indicated that rifamycin SV can increase NADH-dependent microsomal production of reactive oxygen species. The current study evaluated the ability of rifamycin SV to interact with iron and increase microsomal production of hydroxyl radical, as detected by conversion of supercoiled plasmid DNA into the relaxed open circular state. The plasmid used was pBluescript II KS(-), and the forms of DNA were separated by agarose-gel electrophoresis. Incubation of rat liver microsomes with plasmid plus NADH plus ferric-ATP caused DNA strand cleavage. The addition of rifamycin SV produced a time- and concentration-dependent increase in DNA-strand cleavage. No stimulation by rifamycin SV occurred in the absence of microsomes, NADH or ferric-ATP. Stimulation occurred with other ferric complexes besides ferric-ATP, e.g. ferric-histidine, ferric-citrate, ferric-EDTA, and ferric-(NH4)2SO4. Rifamycin SV did not significantly increase the high rates of DNA strand cleavage found with NADPH as the microsomal reductant. The stimulation of NADH-dependent microsomal DNA strand cleavage was completely blocked by catalase, superoxide dismutase, GSH and a variety of hydroxyl-radical-scavenging agents, but not by anti-oxidants that prevent microsomal lipid peroxidation. Redox cycling agents, such as menadione and paraquat, in contrast with rifamycin SV, stimulated the NADPH-dependent reaction; menadione and rifamycin SV were superior to paraquat in stimulating the NADH-dependent reaction. These results indicate that rifamycin SV can, in the presence of an iron catalyst, increase microsomal production of reactive oxygen species which can cause DNA-strand cleavage. In contrast with other redox cycling agents, the stimulation by rifamycin SV is more pronounced with NADH than with NADPH as the

Metallated metal-organic frameworks

Energy Technology Data Exchange (ETDEWEB)

Bury, Wojciech; Farha, Omar K.; Hupp, Joseph T.; Mondloch, Joseph E.

2017-08-22

Porous metal-organic frameworks (MOFs) and metallated porous MOFs are provided. Also provided are methods of metallating porous MOFs using atomic layer deposition and methods of using the metallated MOFs as catalysts and in remediation applications.

Nanofluidic technology for biomolecule applications: a critical review

NARCIS (Netherlands)

Napoli, M.; Eijkel, Jan C.T.; Pennathur, S.

2010-01-01

In this review, we present nanofluidic phenomena, particularly as they relate to applications involving analysis of biomolecules within nanofabricated devices. The relevant length scales and physical phenomena that govern biomolecule transport and manipulation within nanofabricated nanofluidic

FAIRY: a randomized controlled patient-blind phase III study to compare the efficacy and safety of intravenous ferric carboxymaltose (Ferinject®) to placebo in patients with acute isovolemic anemia after gastrectomy - study protocol for a randomized controlled trial.

Science.gov (United States)

Reim, Daniel; Kim, Young-Woo; Nam, Byung Ho; Kim, Mi-Jung; Yook, Jeong Hwan; Park, Young Kyu; Roh, Sung Hoon; Yu, Wan Sik; Bae, Jae Moon

2014-04-05

Isovolemic anemia (decrease in hemoglobin concentration with normal or even increased blood volume) after gastric cancer surgery may negatively influence short- and long-term outcomes. Therefore correction of isovolemic postoperative anemia is supposed to be beneficial. This prospective randomized placebo-controlled multicenter trial is designed to evaluate the efficacy of ferric carboxymaltose administration with the primary end point of successful hemoglobin level increase by 2 g/dl at 12 weeks after randomization. Gastric cancer patients after oncologic resection and postoperative hemoglobin level ≥ 7 g/dl to hemoglobin level, hematology and quality of life assessment 3 and 12 weeks after randomization. Correction of isovolemic postoperative anemia in gastric cancer patients after oncologic resection is considered to be beneficial. Administration of ferric carboxymaltose is considered to be superior to placebo for anemia correction without the possible risks of red blood cell transfusion. Further, improved quality of life for patients with quick recovery of hemoglobin levels is expected. NCT01725789 (international: http://www.clinicaltrials.gov) and NCCCTS-12-644 (NCC, Korea).

A modular continuous flow reactor system for the selective bio-oxidation of iron and precipitation of schwertmannite from mine-impacted waters.

Science.gov (United States)

Hedrich, Sabrina; Johnson, D Barrie

2012-02-01

A novel modular bioremediation system which facilitates the selective removal of soluble iron from extremely acidic (pH ∼2) metal-rich wastewaters by ferrous iron oxidation and selective precipitation of the ferric iron produced is described. In the first of the three modules, rapid ferrous iron oxidation was mediated by the recently-characterized iron-oxidizing autotrophic acidophile, "Ferrovum myxofaciens", which grew as long "streamers" within the reactor. Over 90% of the iron present in influent test liquors containing 280mg/L iron was oxidized at a dilution rate of 0.41h(-1), in a proton-consuming reaction. The ferric iron-rich solutions produced were pumped into a second reactor where controlled addition of sodium hydroxide caused the water pH to increase to 3.5 and ferric iron to precipitate as the mineral schwertmannite. Addition of a flocculating agent promoted rapid aggregation and settling of the fine-grain schwertmannite particles. A third passive module (a packed-bed bioreactor, also inoculated with "Fv. myxofaciens") acted as a polishing reactor, lowering soluble iron concentrations in the processed water to iron from a synthetic acidic (pH 2.1) mine water that contained soluble aluminum, copper, manganese and zinc in addition to iron. Schwertmannite was again produced, with little or no co-precipitation of other metals. Copyright © 2011 Elsevier Ltd. All rights reserved.

Recycling of electric appliances. Utilization of the new EU regulation; Recycling von Elektrogeraeten. Nutzen der neuen EU-Richtlinie

Energy Technology Data Exchange (ETDEWEB)

Friege, Henning [Awista GmbH, Duesseldorf (Germany)

2012-10-15

In the light of a shortage of resources the recycling of secondary raw materials and especially of metals from electric appliances is increasingly gaining importance. If one is to believe the announcements, everything is regulated in the best way. But when one considers closer the data from the recycling of resources and especially the non-ferric (NF) metals from electric and electronic appliances, this still is not a success story - we ought to write it.

Flocculation of Chlamydomonas reinhardtii with Different Phenotypic Traits by Metal Cations and High pH

Directory of Open Access Journals (Sweden)

Jianhua Fan

2017-11-01

Full Text Available Concentrating algal cells by flocculation as a prelude to centrifugation could significantly reduce the energy and cost of harvesting the algae. However, how variation in phenotypic traits such as cell surface features, cell size and motility alter the efficiency of metal cation and pH-induced flocculation is not well understood. Our results demonstrate that both wild-type and cell wall-deficient strains of the green unicellular alga Chlamydomonas reinhardtii efficiently flocculate (>90% at an elevated pH of the medium (pH 11 upon the addition of divalent cations such as calcium and magnesium (>5 mM. The trivalent ferric cation (at 10 mM proved to be essential for promoting flocculation under weak alkaline conditions (pH ∼8.5, with a maximum efficiency that exceeded 95 and 85% for wild-type CC1690 and the cell wall-deficient sta6 mutant, respectively. Near complete flocculation could be achieved using a combination of 5 mM calcium and a pH >11, while the medium recovered following cell removal could be re-cycled without affecting algal growth rates. Moreover, the absence of starch in the cell had little overall impact on flocculation efficiency. These findings contribute to our understanding of flocculation in different Chlamydomonas strains and have implications with respect to inexpensive methods for harvesting algae with different phenotypic traits. Additional research on the conditions (e.g., pH and metal ions used for efficient flocculation of diverse algal groups with diverse characteristics, at both small and large scale, will help establish inexpensive procedures for harvesting cell biomass.

Non-transferrin-bound iron (NTBI uptake by T lymphocytes: evidence for the selective acquisition of oligomeric ferric citrate species.

Directory of Open Access Journals (Sweden)

Joao Arezes

Full Text Available Iron is an essential nutrient in several biological processes such as oxygen transport, DNA replication and erythropoiesis. Plasma iron normally circulates bound to transferrin. In iron overload disorders, however, iron concentrations exceed transferrin binding capacity and iron appears complexed with low molecular weight molecules, known as non-transferrin-bound iron (NTBI. NTBI is responsible for the toxicity associated with iron-overload pathologies but the mechanisms leading to NTBI uptake are not fully understood. Here we show for the first time that T lymphocytes are able to take up and accumulate NTBI in a manner that resembles that of hepatocytes. Moreover, we show that both hepatocytes and T lymphocytes take up the oligomeric Fe3Cit3 preferentially to other iron-citrate species, suggesting the existence of a selective NTBI carrier. These results provide a tool for the identification of the still elusive ferric-citrate cellular carrier and may also open a new pathway towards the design of more efficient iron chelators for the treatment of iron overload disorders.

Dragon Fruit Foliage Plant-Based Coagulant for Treatment of Concentrated Latex Effluent: Comparison of Treatment with Ferric Sulfate

Directory of Open Access Journals (Sweden)

Juferi Idris

2013-01-01

Full Text Available The effectiveness of dragon fruit foliage as a natural coagulant for treatment of concentrated latex effluent was investigated and compared with ferric sulfate, a chemical coagulant. Dragon fruit is a round and often red-colored fruit with scales-like texture and is native to south American countries which is also cultivated and heavily marketed in southeast Asian countries. Its foliage represents a part of its overall plant system. Latex effluent is one of the main byproduct from rubber processing factories in Malaysia. Three main parameters investigated were chemical oxygen demand (COD, suspended solids (SS, and turbidity of effluent. Coagulation experiments using jar test were performed with a flocculation system where the effects of latex effluent pH as well as coagulation dosage on coagulation effectiveness were examined. The highest recorded COD, SS, and turbidity removal percentages for foliage were observed for effluent pH 10 at 94.7, 88.9, and 99.7%, respectively. It is concluded that the foliage showed tremendous potential as a natural coagulant for water treatment purposes. The foliage could be used in the pretreatment stage of Malaysian latex effluent prior to secondary treatment.

Nanofabrication with biomolecules

OpenAIRE

Chow, Dominic C.; Johannes, Matthew S.; Lee, Woo-Kyung; Clark, Robert L.; Zauscher, Stefan; Chilkoti, Ashutosh

2005-01-01

The advances in biotechnology and nanotechnology are spawning a new and exciting manufacturing tool – bionanofabrication – which enables revolutionary ways of building complex bionanostructures on surfaces with nanometer precision. Here, we highlight the opportunities and challenges in the development of this emerging technology and discuss its use in genomics, proteomics, nanostructures, nanomaterials, drug discovery, and synthetic biology. To provide useful insights into the future directio...

Method of producing homogeneous mixed metal oxides and metal-metal oxide mixtures

International Nuclear Information System (INIS)

Quinby, T.C.

1980-01-01

A method for preparing particulate metal or metal oxide of controlled partile size comprises contacting an an aqueous solution containing dissolved metal values with excess urea at a temperature sufficient to cause urea to react with water to provide a molten urea solution containing the metal values; heating the molten urea solution to cause the metal values to precipitate, forming a mixture containing precipitated metal values; heating the mixture containing precipitated metal values to evaporate volatile material leaving a dry powder containing said metal values. The dry powder can be calcined to provide particulate metal oxide or reduced to provide particulate metal. Oxide mixtures are provided when the aqueous solution contains values of more than one metal. Homogeneousmetal-metal oxide mistures for preparing cermets can be prepared by selectively reducing at least one of the metal oxides. (auth)

Method of producing homogeneous mixed metal oxides and metal--metal oxide mixtures

International Nuclear Information System (INIS)

Quinby, T.C.

1978-01-01

Metal powders, metal oxide powders, and mixtures thereof of controlled particle size are provided by reacting an aqueous solution containing dissolved metal values with excess urea. Upon heating, urea reacts with water from the solution to leave a molten urea solution containing the metal values. The molten urea solution is heated to above about 180 0 C, whereupon metal values precipitate homogeneously as a powder. The powder is reduced to metal or calcined to form oxide particles. One or more metal oxides in a mixture can be selectively reduced to produce metal particles or a mixture of metal and metal oxide particles

Mechanism of pyrrhotite formation from ferric oxyhydroxide catalyst; Kokoritsu sekitan ekika shokubai no kaihatsu (Okishi suisankatetsu shokubai karano pyrrhotite seisei kyodo)

Energy Technology Data Exchange (ETDEWEB)

Tazawa, K.; Koyama, T.; Kaneko, T.; Shimasaki, K. [Nippon Brown Coal Liquefaction Co. Ltd., Tokyo (Japan)

1996-10-28

It is thought that iron-based catalysts for coal liquefaction exercise their catalytic activity by forming pyrrhotite (Fe(1-x)S). However, there are still a lot of unknown problems remained concerning the formation and agglomeration behaviors of pyrrhotite. These make a difficulty for improving the activity of iron-based catalysts. In this study, sulfiding behaviors of {alpha}-iron oxyhydroxide ({alpha}-FeOOH) and {gamma}-iron oxyhydroxide ({gamma}-FeOOH) were investigated to reveal the formation and agglomeration behaviors of pyrrhotite. It was found that pyrrhotite was easily converted from ferric oxyhydroxide catalysts having large specific surface areas at the sulfiding temperature below 250{degree}C, and fine crystallites of pyrrhotite were formed at the initial stage of sulfiding. Crystal growth of pyrrhotite at the sulfiding temperature over 350{degree}C depended on the catalyst forms. It was also found that smaller crystallites of pyrrhotite were formed from {gamma}-FeOOH than from {alpha}-FeOOH and amorphous iron oxyhydroxide. 5 refs., 7 figs., 1 tab.

Nanoparticles with tunable shape and composition fabricated by nanoimprint lithography.

Science.gov (United States)

Alayo, Nerea; Conde-Rubio, Ana; Bausells, Joan; Borrisé, Xavier; Labarta, Amilcar; Batlle, Xavier; Pérez-Murano, Francesc

2015-11-06

Cone-like and empty cup-shaped nanoparticles of noble metals have been demonstrated to provide extraordinary optical properties for use as optical nanoanntenas or nanoresonators. However, their large-scale production is difficult via standard nanofabrication methods. We present a fabrication approach to achieve arrays of nanoparticles with tunable shape and composition by a combination of nanoimprint lithography, hard-mask definition and various forms of metal deposition. In particular, we have obtained arrays of empty cup-shaped Au nanoparticles showing an optical response with distinguishable features associated with the excitations of localized surface plasmons. Finally, this route avoids the most common drawbacks found in the fabrication of nanoparticles by conventional top-down methods, such as aspect ratio limitation, blurring, and low throughput, and it can be used to fabricate nanoparticles with heterogeneous composition.

Nonlocal inhomogeneous broadening in plasmonic nanoparticle ensembles

DEFF Research Database (Denmark)

Tserkezis, Christos; Maack, Johan Rosenkrantz; Liu, Z.

Nonclassical effects are increasingly more relevant in plasmonics as modern nanofabrication techniques rapidly approach the extreme nanoscale limits, for which departing from classical electrodynamics becomes important. One of the largest-scale necessary corrections towards this direction...... is to abandon the local response approximation (LRA) and take the nonlocal response of the metal into account, typically through the simple hydrodynamic Drude model (HDM), which predicts a sizedependent deviation of plasmon modes from the quasistatic (QS) limit. While this behaviour has been explored for simple...... metallic nanoparticles (NPs) or NP dimers, the possibility of inhomogeneous resonance broadening due to size variation in a large NP collection and the resulting spectral overlap of modes (as depicted in Fig. 1), has been so far overlooked. Here we study theoretically the effect of nonlocality on ensemble...

Nanoparticles with tunable shape and composition fabricated by nanoimprint lithography

International Nuclear Information System (INIS)

Alayo, Nerea; Bausells, Joan; Pérez-Murano, Francesc; Conde-Rubio, Ana; Labarta, Amilcar; Batlle, Xavier; Borrisé, Xavier

2015-01-01

Cone-like and empty cup-shaped nanoparticles of noble metals have been demonstrated to provide extraordinary optical properties for use as optical nanoanntenas or nanoresonators. However, their large-scale production is difficult via standard nanofabrication methods. We present a fabrication approach to achieve arrays of nanoparticles with tunable shape and composition by a combination of nanoimprint lithography, hard-mask definition and various forms of metal deposition. In particular, we have obtained arrays of empty cup-shaped Au nanoparticles showing an optical response with distinguishable features associated with the excitations of localized surface plasmons. Finally, this route avoids the most common drawbacks found in the fabrication of nanoparticles by conventional top-down methods, such as aspect ratio limitation, blurring, and low throughput, and it can be used to fabricate nanoparticles with heterogeneous composition. (paper)

Diamond anvil cells using boron-doped diamond electrodes covered with undoped diamond insulating layer

Science.gov (United States)

Matsumoto, Ryo; Yamashita, Aichi; Hara, Hiroshi; Irifune, Tetsuo; Adachi, Shintaro; Takeya, Hiroyuki; Takano, Yoshihiko

2018-05-01

Diamond anvil cells using boron-doped metallic diamond electrodes covered with undoped diamond insulating layers have been developed for electrical transport measurements under high pressure. These designed diamonds were grown on a bottom diamond anvil via a nanofabrication process combining microwave plasma-assisted chemical vapor deposition and electron beam lithography. The resistance measurements of a high-quality FeSe superconducting single crystal under high pressure were successfully demonstrated by just putting the sample and gasket on the bottom diamond anvil directly. The superconducting transition temperature of the FeSe single crystal was increased to up to 43 K by applying uniaxial-like pressure.

Influence of mechanical activation on the leaching of non-ferrous metals from a CuPbZn complex concentrate

Directory of Open Access Journals (Sweden)

Godoèíková Erika

2000-09-01

Full Text Available The aim of study was to research the procedures of copper, lead and zinc leaching from CuPbZn complex sulphide concentrate during the intervention of mechanical activation.Mechanical activation belongs to innovative procedures, which intensifies technological processes by means of creation of new surfaces and making defective structure of solid phase. Mechanical impact on the solid phase is a suitable procedure to ensure the mobility of its structure elements and to accumulate the mechanical energy that is later used in following processes of leaching.This paper deals with the intensification of the chloride and thiourea leaching of copper, lead and zinc from a CuPbZn complex concentrate of Hodruša-Hámre (Slovak deposit by using the mechanical activation in an attritor. Ferric chloride and thiourea were used as leaching reagents. The leaching of the concentrate with ferric chloride solution afforded 23 % recovery of Cu, 99 % of Pb and 28 % of Zn. 9 % recovery of Cu, 17 % of Pb and 3 % of Zn were achieved by the leaching with thiourea. Thus results showed that the extraction of Cu, Zn and also Pb in the case of thiourea leaching was low. The use of milling in the attritor as an innovation method of pretreatment leads to the structural degradation and increasing the surface area of the investigated concentrate from the original value of 0.18 m2g-1 to the maximum value of 4.67 m2g-1. This fact manifested itself in the subsequent process of extraction of Cu, Pb and Zn into the chloride and thiourea solutions. Our results indicate more effective leaching of pretreated concentrate in the chloride medium with recoveries of 84 % Zn and 100 % Pb. In thiourea, the recoveries for Zn and Pb were low, however 99 % Cu can be recovered. In regard to the economy, the extraction of Cu, Pb and Zn was studied in this work with the aspect of minimal energy consumption during milling. The maximum recoveries of non-ferrous metals in the solutions of ferric chloride

Student Support for EIPBN 2014 Conference - Final Report

Energy Technology Data Exchange (ETDEWEB)

Farrow, Reginald C.

2014-09-16

The 58th International Conference on Electron, Ion and Photon Beam Technology and Nanofabrication (EIPBN), 2014, was held at the Omni Shoreham Hotel in Washington, DC, May 27 to 30, 2014. The EIPBN Conference is recognized as the foremost international meeting dedicated to lithographic science and technology and its application to micro and nanofabrication techniques. The conference brought together 386 engineers and scientists from industries and universities from all over the world to discuss recent progress and future trends. Among the emerging technologies that are within the scope of EIPBN is Nanofabrication for Energy Sources along with nanofabrication for the realization of low power integrated circuits. Every year, EIPBN provides financial support for students to attend the conference. Travel support for 43 students came from a mixture of government agencies and corporate donors. The Department of Energy Office of Basic Energy Sciences provided $5,000 to support student travel from US universities to participate at EIPBN 2014 through grant DE-SC0011789.

pH dependence of cyanide binding to the ferric heme domain of the direct oxygen sensor from Escherichia coli and the effect of alkaline denaturation.

Science.gov (United States)

Bidwai, Anil K; Ok, Esther Y; Erman, James E

2008-09-30

The spectrum of the ferric heme domain of the direct oxygen sensor protein from Escherichia coli ( EcDosH) has been measured between pH 3.0 and 12.6. EcDosH undergoes acid denaturation with an apparent p K a of 4.24 +/- 0.05 and a Hill coefficient of 3.1 +/- 0.6 and reversible alkaline denaturation with a p K a of 9.86 +/- 0.04 and a Hill coefficient of 1.1 +/- 0.1. Cyanide binding to EcDosH has been investigated between pH 4 and 11. The EcDosH-cyanide complex is most stable at pH 9 with a K D of 0.29 +/- 0.06 microM. The kinetics of cyanide binding are monophasic between pH 4 and 8. At pH >or=8.5, the reaction is biphasic with the fast phase dependent upon the cyanide concentration and the slow phase independent of cyanide. The slow phase is attributed to conversion of denatured EcDosH to the native state, with a pH-independent rate of 0.052 +/- 0.006 s (-1). The apparent association rate constant for cyanide binding to EcDosH increases from 3.6 +/- 0.1 M (-1) s (-1) at pH 4 to 520 +/- 20 M (-1) s (-1) at pH 11. The dissociation rate constant averages (8.6 +/- 1.3) x 10 (-5) s (-1) between pH 5 and 9, increasing to (1.4 +/- 0.1) x 10 (-3) s (-1) at pH 4 and (2.5 +/- 0.1) x 10 (-3) s (-1) at pH 12.2. The mechanism of cyanide binding is consistent with preferential binding of the cyanide anion to native EcDosH. The reactions of imidazole and H 2O 2 with ferric EcDosH were also investigated and show little reactivity.

Radioactive waste material disposal

Science.gov (United States)

Forsberg, Charles W.; Beahm, Edward C.; Parker, George W.

1995-01-01

The invention is a process for direct conversion of solid radioactive waste, particularly spent nuclear fuel and its cladding, if any, into a solidified waste glass. A sacrificial metal oxide, dissolved in a glass bath, is used to oxidize elemental metal and any carbon values present in the waste as they are fed to the bath. Two different modes of operation are possible, depending on the sacrificial metal oxide employed. In the first mode, a regenerable sacrificial oxide, e.g., PbO, is employed, while the second mode features use of disposable oxides such as ferric oxide.

Recovery of gold and uranium from calcines

Energy Technology Data Exchange (ETDEWEB)

Livesey-Goldblatt, E.

1981-10-06

The invention concerns the recovery of non-ferrous metals, such as gold, uranium or the like from iron oxide containing calcines which have the non-ferrous metal present in solid solution and/or encapsulated within the iron oxide. The calcine is reacted, while stirring vigorously, with sulphuric acid or another strong inorganic acid to cause the iron to form the ferric salt. The material obtained is mixed with water and the liquid and solid phases are separated from each other. The non-ferrous metal is then obtained from at least one of these phases by leaching, or the like.

Extracting metals directly from metal oxides

International Nuclear Information System (INIS)

Wai, C.M.; Smart, N.G.; Phelps, C.

1997-01-01

A method of extracting metals directly from metal oxides by exposing the oxide to a supercritical fluid solvent containing a chelating agent is described. Preferably, the metal is an actinide or a lanthanide. More preferably, the metal is uranium, thorium or plutonium. The chelating agent forms chelates that are soluble in the supercritical fluid, thereby allowing direct removal of the metal from the metal oxide. In preferred embodiments, the extraction solvent is supercritical carbon dioxide and the chelating agent is selected from the group consisting of β-diketones, halogenated β-diketones, phosphinic acids, halogenated phosphinic acids, carboxylic acids, halogenated carboxylic acids, and mixtures thereof. In especially preferred embodiments, at least one of the chelating agents is fluorinated. The method provides an environmentally benign process for removing metals from metal oxides without using acids or biologically harmful solvents. The chelate and supercritical fluid can be regenerated, and the metal recovered, to provide an economic, efficient process. 4 figs

Effect of Arsenic on the Formation and Adsorption Property of Ferric Hydroxide Precipitates in ZVI Treatment

Energy Technology Data Exchange (ETDEWEB)

Peng, Xing; Xi, Beidou; Zhao, Ying; Shi, Qiantao; Meng, Xiaoguang; Mao, Xuhui; Jiang, Yonghai; Ma, Zhifei; Tan, Wenbing; Liu, Hongliang; Gong, Bin (Stevens); (Beijing NU); (CRAES); (Wuhan)

2017-08-14

Treatment of arsenic by zerovalent iron (ZVI) has been studied extensively. However, the effect of arsenic on the formation of ferric hydroxide precipitates in the ZVI treatment has not been investigated. We discovered that the specific surface area (ca. 187 m2/g) and arsenic content (ca. 67 mg/g) of the suspended solids (As-containing solids) generated in the ZVI treatment of arsenic solutions were much higher than the specific surface area (ca. 37 m2/g) and adsorption capacity (ca.12 mg/g) of the suspended solids (As-free solids) generated in the arsenic-free solutions. Arsenic in the As-containing solids was much more stable than the adsorbed arsenic in As-free solids. XRD, SEM, TEM, and selected area electron diffraction (SAED) analyses showed that the As-containing solids consisted of amorphous nanoparticles, while the As-free solids were composed of micron particles with weak crystallinity. Extended X-ray absorption fine structure (EXAFS) analysis determined that As(V) was adsorbed on the As-containing suspended solids and magnetic solid surfaces through bidentate binuclear complexation; and As(V) formed a mononuclear complex on the As-free suspended solids. The formation of the surface As(V) complexes retarded the bonding of free FeO6 octahedra to the oxygen sites on FeO6 octahedral clusters and prevented the growth of the clusters and their development into 3-dimensional crystalline phases.

Protective Effect of Low Dose Gamma Irradiation against Oxidative Damage in Rats Administrated with Ferric- Nitrilotriacetate

International Nuclear Information System (INIS)

Mansonr, S.Z.

2009-01-01

Many studies have demonstrated the beneficial adaptive response of low dose gamma-irradiation. Low dose gamma-irradiation (LDR) might be effective for the prevention of various reactive oxygen species-related diseases. Ferric nitrilotriacetate (Fe-NTA) is a strong oxidant, which generates highly reactive hydroxyl radical and causes injuries of various organs including the kidney and liver. This study was designed to investigate the ability of low dose gamma-irradiation to restrain Fe-NT A induced oxidative stress. Sprague Dawley male albino rats were subjected to low dose gamma-irradiation (50 cGy). Animals were challenged with Fe-NT A (9 mg Fe/kg body weight, intraperitoneally). Results showed that Fe-NTA enhances lipid peroxidation (LPx) accompanied with reduction in glutathione (GSH) content, antioxidant enzymes, viz., glutathione peroxidase (GPX), glutathione reductase (GR), superoxide dismutase (SOD), catalase (CAT) and phase-U metabolizing enzyme glutathione-S-transferase (GST). Fe-NTA also enhances the concentration of blood urea nitrogen (BUN) and serum creatinine as well as alanine aminotransferase (ALT), aspartate aminotransferase (AST) and gamma-glutamyl transpeptidase (GGT) activities. Exposure to low dose gamma- irradiation (3 h after Fe-NTA administration) resulted in a significant decrease in LPx, BUN, serum creatinine contents as well as ALT, AST and GGT enzyme activities. GSH content; GST and antioxidant enzymes were also recovered to significant level. Thus, our data suggest that exposure to LDR might be a useful antioxidant mediator to suppress the Fe-NTA induced-oxidative damage in rats

Protective Effect of Low Dose Gamma Irradiation against Oxidative Damage in Rats Administrated with Ferric- Nitrilotriacetate

International Nuclear Information System (INIS)

Mansonr, S.Z.

2008-01-01

Many studies have demonstrated the beneficial adaptive response of low dose gamma-irradiation. Low dose gamma-irradiation (LDR) might be effective for the prevention of various reactive oxygen species-related diseases. Ferric nitrilotriacetate (Fe-NTA) is a strong oxidant, which generates highly reactive hydroxyl radical and causes injuries of various organs including the kidney and liver. This study was designed to investigate the ability of low dose gamma-irradiation to restrain Fe-NT A induced oxidative stress. Sprague Dawley male albino rats were subjected to low dose gamma-irradiation (50 cGy). Animals were challenged with Fe-NT A (9 mg Fe/kg body weight, intraperitoneally). Results showed that Fe-NTA enhances lipid peroxidation (LPx) accompanied with reduction in glutathione (GSH) content, antioxidant enzymes, viz., glutathione peroxidase (GPX), glutathione reductase (GR), superoxide dismutase (SOD), catalase (CAT) and phase-U metabolizing enzyme glutathione-S-transferase (GST). Fe-NTA also enhances the concentration of blood urea nitrogen (BUN) and serum creatinine as well as alanine aminotransferase (ALT), aspartate aminotransferase (AST) and gamma-glutamyl transpeptidase (GGT) activities. Exposure to low dose gamma- irradiation (3 h after Fe-NTA administration) resulted in a significant decrease in LPx, BUN, serum creatinine contents as well as ALT, AST and GGT enzyme activities. GSH content; GST and antioxidant enzymes were also recovered to significant level. Thus, our data suggest that exposure to LDR might be a useful antioxidant mediator to suppress the Fe-NTA induced-oxidative damage in rats

Comparative Evaluation of U.S. Brand and Generic Intravenous Sodium Ferric Gluconate Complex in Sucrose Injection: Physicochemical Characterization

Directory of Open Access Journals (Sweden)

Dajun Sun

2018-01-01

Full Text Available The objective of this study was to evaluate physicochemical equivalence between brand (i.e., Ferrlecit and generic sodium ferric gluconate (SFG in sucrose injection by conducting a series of comparative in vitro characterizations using advanced analytical techniques. The elemental iron and carbon content, thermal properties, viscosity, particle size, zeta potential, sedimentation coefficient, and molecular weight were determined. There was no noticeable difference between brand and generic SFG in sucrose injection for the above physical parameters evaluated, except for the sedimentation coefficient determined by sedimentation velocity analytical ultracentrifugation (SV-AUC and molecular weight by asymmetric field flow fractionation-multi-angle light scattering (AFFF-MALS. In addition, brand and generic SFG complex products showed comparable molecular weight distributions when determined by gel permeation chromatography (GPC. The observed minor differences between brand and generic SFG, such as sedimentation coefficient, do not impact their biological activities in separate studies of in vitro cellular uptake and rat biodistribution. Coupled with the ongoing clinical study comparing the labile iron level in healthy volunteers, the FDA-funded post-market studies intended to illustrate comprehensive surveillance efforts ensuring safety and efficacy profiles of generic SFG complex in sucrose injection, and also to shed new light on the approval standards on generic parenteral iron colloidal products.

Transuranium removal from Hanford high level waste simulants using sodium permanganate and calcium

International Nuclear Information System (INIS)

Wilmarth, W.R.; Rosencrance, S.W.; Nash, C.A.; Fonduer, F.F.; Di Pirete, D.P.; Di Prete, C.C.

2000-01-01

Plutonium and americium are present in the Hanford high level liquid waste complexant concentrate (CC) due to the presence of complexing agents including di-(2-ethylhexyl) phosphoric acid (D 2 EHPA), tributylphosphate (TBP), hydroxyethylene diamine triacetic acid (HEDTA), ethylene diamine tetraacetic acid (EDTA), citric acid, glycolic acid, and sodium gluconate. The transuranic concentrations approach 600 nCi/g and require processing prior to encapsulation into low activity glass. BNFL's (British Nuclear Fuels Limited's) original process was a ferric co-precipitation method based on earlier investigations by Herting and Orth, et al. Furthermore, flocculation and precipitation are widely used for clarification in municipal water treatment. Co-precipitation of Np, Am, and Pu with ferric hydroxide is also used within an analytical method for the sum of those analytes. Tests to evaluate BNFL's original precipitation process indicated the measured decontamination factors (DFs) and filter fluxes were too low. Therefore, an evaluation of alternative precipitation agents to replace ferric ion was undertaken. Agents tested included various transition metals, lanthanide elements, uranium species, calcium, strontium, and permanganate

Radionuclide sorption in soils and sediments: oxide-organic matter competition

International Nuclear Information System (INIS)

Maes, A.; Cremers, A.

1986-01-01

This paper deals with the speciation of europium in the solid phase and liquid phase extracts of Boom Clay under in situ conditions. Using a new method for measuring the europium-humic acid complex stability constant at high pH, it is shown that carbonate complexation is poorly competitive with humic acid, europium being quantitatively present as humic acid complex, its stability constant being of the order of 10 12 -10 13 . It is furthermore shown that partial oxidation of the sediment, which is strongly reducing under in situ conditions, leads to a significant increase in Ksub(D) values, whatever the liquid/solid ratio used. This effect is ascribed to the involvement of ferric oxides which are generated in the solid phase and which lead to a displacement of the metal from the humic acid sink. Some examples are presented which demonstrate that at high pH, around 9, ferric oxides may be competitive with humic acids for metal sorption and that this effect increases with pH. (author)

Moessbauer spectra of olivine-rich achondrites - Evidence for preterrestrial redox reactions

Science.gov (United States)

Burns, R. G.; Martinez, S. L.

1991-01-01

Moessbauer spectral measurements at 4.2 K were made on several ureilites and the two shergottites found in Antarctica, as well as two ureilite falls, three SNC meteorite falls, and two finds in order to distinguish products of preterrestrial redox reactions from phases formed during oxidative weathering on the earth. The spectra indicated that several ureilites contain major proportions of metallic iron, much of which resulted from preterrestrial carbon-induced reduction of ferrous iron in the outermost 10-100 microns of olivine grains in contact with carbonaceous material in the ureilites. The cryptocrystalline nature of these Fe inclusions in olivine renders the metal extremely vulnerable to aerial oxidation, even in ureilites collected as falls. It is inferred that the nanophase ferric oxides or oxyhydroxides identified in Brachina and Lafayette were produced by terrestrial weather of olivines before the meteorites were found. The absence of goethite in two olivine-bearing Antarctic shergottites suggests that the 2 percent ferric iron determined in their Moessbauer spectra also originated from oxidation on Mars.

Radionuclide sorption in soils and sediments: Oxide - organic matter competition

International Nuclear Information System (INIS)

Maes, A.; Cremers, A.

1985-01-01

This paper deals with the speciation of europium in the solid phase and liquid phase extracts of Boom clay under in situ conditions. Using a new method for measuring the europium-humic acid complex stability constant at high pH, it is shown that carbonate complexation is poorly competitive with humic acid, europium being quantitatively present as humic acid complex, its stability constant being of the order of 10/sup 12/--10/sup 13/. It is furthermore shown that partial oxidation of the sediment, which is strongly reducing under in situ conditions, leads to a significant increase in K/sub D/ values, whatever the liquid/solid ratio used. This effect is ascribed to the involvement of ferric oxides which are generated in the solid phase and which lead to a displacement of the metal from the humic acid sink. Some examples are presented which demonstrate that a high pH, around 9, ferric oxides may be competitive with humic acids for metal sorption and that this effect increases with pH

Oxidative stability of soybean oil in oleosomes as affected by pH and iron.

Science.gov (United States)

Kapchie, Virginie N; Yao, Linxing; Hauck, Catherine C; Wang, Tong; Murphy, Patricia A

2013-12-01

The oxidative stability of oil in soybean oleosomes, isolated using the Enzyme-Assisted Aqueous Extraction Process (EAEP), was evaluated. The effects of ferric chloride, at two concentration levels (100 and 500 μM), on lipid oxidation, was examined under pH 2 and 7. The peroxide value (PV) and thiobarbituric acid-reactive substance (TBARS) value of oil, in oleosome suspensions stored at 60 °C, were measured over a 12 day period. The presence of ferric chloride significantly (Poil in the isolated oleosome, as measured by the PV and TBARS. Greater lipid oxidation occurred under an acidic pH. In the pH 7 samples, the positively charged transition metals were strongly attracted to the negatively charged droplets. However, the low ζ-potential and the high creaming rate at this pH, may have limited the oxidation. Freezing, freeze-drying or heating of oleosomes have an insignificant impact on the oxidative stability of oil in isolated soybean oleosomes. Manufacturers should be cautious when adding oleosomes as ingredients in food systems containing transition metal ions. Published by Elsevier Ltd.

Distribution of heavy metals in cocoa farm soils in the Western Region of Ghana

International Nuclear Information System (INIS)

Ackah, Justice Edusei

2012-10-01

Western Region is the largest cocoa producer in Ghana. Cocoa farmlands have over the past decades received heavy doses of agrochemical application to boost cocoa production. These agrochemicals, however, may contain heavy metals and it is therefore likely that the metals may have accumulated in the soils. Evaluating the total concentrations and understanding the distribution characteristics of heavy metals in cocoa growing soils can aid environmental managers and even help regulate the rate of agrochemical application. A study was therefore, carried out on some selected soils of major cocoa growing areas in Western Region of Ghana to determine the levels of cadmium (Cd), chromium (Cr), copper (Cu), iron (Fe), manganese (Mn), nickel (Ni), lead (Pb) and zinc (Zn) in the soils and also to determine some of the soil factors that control the distribution of the heavy metals in the soil. Eight soils (two Haplic Luvisols, three Ferric Acrisols, one Haplic Ferrasol and two Dystric Fluvisols) and their accompanying pristine soils as control were taken from adjacent natural forests sampled at depths of 0 – 10 cm, 10 – 30 cm, 30 – 50 cm, 50 – 80 cm and 80 – 100 cm. These soils were analysed for their particle size distribution, pH, organic carbon, cation exchange capacity, exchangeable bases, and total and bio-available Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn. The study indicated that the ΔpH which is pH_K_C_l – pH_H_2_O were all negative indicating that the soils generally had net negative charges on their colloidal surface. For all soils, clay content and pH increased with depth indicating co-migration of the two soil parameters whilst total organic carbon content decreased with depth. Cation exchange capacity, however, did not show any clear pattern with depth in the soils. The average abundance of heavy metals determined in these soils decreased as follows: Fe > Mn > Cr > Zn > Cu > Cd > Pb > Ni. The soils had low metal contents, less than or within the range of

FAIRY: a randomized controlled patient-blind phase III study to compare the efficacy and safety of intravenous ferric carboxymaltose (Ferinject®) to placebo in patients with acute isovolemic anemia after gastrectomy - study protocol for a randomized controlled trial

OpenAIRE

Reim, Daniel; Kim, Young-Woo; Nam, Byung Ho; Kim, Mi-Jung; Yook, Jeong Hwan; Park, Young Kyu; Roh, Sung Hoon; Yu, Wan Sik; Bae, Jae Moon

2014-01-01

Background Isovolemic anemia (decrease in hemoglobin concentration with normal or even increased blood volume) after gastric cancer surgery may negatively influence short- and long-term outcomes. Therefore correction of isovolemic postoperative anemia is supposed to be beneficial. This prospective randomized placebo-controlled multicenter trial is designed to evaluate the efficacy of ferric carboxymaltose administration with the primary end point of successful hemoglobin level increase by 2 g...

Dielectric-based subwavelength metallic meanders for wide-angle band absorbers.

Science.gov (United States)

Shen, Su; Qiao, Wen; Ye, Yan; Zhou, Yun; Chen, Linsen

2015-01-26

We propose nano-meanders that can achieve wide-angle band absorption in visible regime. The nano-meander consists of a subwavelength dielectric grating covered by continuous ultra-thin Aluminum film (less than one tenth of the incident wavelength). The excited photonic resonant modes, such as cavity mode, surface plasmonic mode and Rayleigh-Wood anomaly, are discussed in detail. Nearly total resonant absorption due to funneling mechanism in the air nano-groove is almost invariant with large incident angle in transverse magnetic polarization. From both the structural geometry and the nanofabrication point of view, the light absorber has a very simple geometrical structure and it is easy to be integrated into complex photonic devices. The highly efficient angle-robust light absorber can be potential candidate for a range of passive and active photonic applications, including solar-energy harvesting as well as producing artificial colors on a large scale substrate.

Durability of metals from archaeological objects, metal meteorites, and native metals

International Nuclear Information System (INIS)

Johnson, A.B. Jr.; Francis, B.

1980-01-01

Metal durability is an important consideration in the multi-barrier nuclear waste storage concept. This study summarizes the ancient metals, the environments, and factors which appear to have contributed to metal longevity. Archaeological and radiochemical dating suggest that human use of metals began in the period 6000 to 7000 BC. Gold is clearly the most durable, but many objects fashioned from silver, copper, bronze, iron, lead, and tin have survived for several thousand years. Dry environments, such as tombs, appear to be optimum for metal preservation, but some metals have survived in shipwrecks for over a thousand years. The metal meteorites are Fe-base alloys with 5 to 60 wt% Ni and minor amounts of Co, I, and S. Some meteoritic masses with ages estimated to be 5,000 to 20,000 years have weathered very little, while other masses from the same meteorites are in advanced stages of weathering. Native metals are natural metallic ores. Approximately five million tonnes were mined from native copper deposits in Michigan. Copper masses from the Michigan deposits were transported by the Pleistocene glaciers. Areas on the copper surfaces which appear to represent glacial abrasion show minimal corrosion. Dry cooling tower technology has demonstrated that in pollution-free moist environments, metals fare better at temperatures above than below the dewpoint. Thus, in moderate temperature regimes, elevated temperatures may be useful rather than detrimental for exposures of metal to air. In liquid environments, relatively complex radiolysis reactions can occur, particularly where multiple species are present. A dry environment largely obviates radiolysis effects

Durability of metals from archaeological objects, metal meteorites, and native metals

Energy Technology Data Exchange (ETDEWEB)

Johnson, A.B. Jr.; Francis, B.

1980-01-01

Metal durability is an important consideration in the multi-barrier nuclear waste storage concept. This study summarizes the ancient metals, the environments, and factors which appear to have contributed to metal longevity. Archaeological and radiochemical dating suggest that human use of metals began in the period 6000 to 7000 BC. Gold is clearly the most durable, but many objects fashioned from silver, copper, bronze, iron, lead, and tin have survived for several thousand years. Dry environments, such as tombs, appear to be optimum for metal preservation, but some metals have survived in shipwrecks for over a thousand years. The metal meteorites are Fe-base alloys with 5 to 60 wt% Ni and minor amounts of Co, I, and S. Some meteoritic masses with ages estimated to be 5,000 to 20,000 years have weathered very little, while other masses from the same meteorites are in advanced stages of weathering. Native metals are natural metallic ores. Approximately five million tonnes were mined from native copper deposits in Michigan. Copper masses from the Michigan deposits were transported by the Pleistocene glaciers. Areas on the copper surfaces which appear to represent glacial abrasion show minimal corrosion. Dry cooling tower technology has demonstrated that in pollution-free moist environments, metals fare better at temperatures above than below the dewpoint. Thus, in moderate temperature regimes, elevated temperatures may be useful rather than detrimental for exposures of metal to air. In liquid environments, relatively complex radiolysis reactions can occur, particularly where multiple species are present. A dry environment largely obviates radiolysis effects.

MetalS(3), a database-mining tool for the identification of structurally similar metal sites.

Science.gov (United States)

Valasatava, Yana; Rosato, Antonio; Cavallaro, Gabriele; Andreini, Claudia

2014-08-01

We have developed a database search tool to identify metal sites having structural similarity to a query metal site structure within the MetalPDB database of minimal functional sites (MFSs) contained in metal-binding biological macromolecules. MFSs describe the local environment around the metal(s) independently of the larger context of the macromolecular structure. Such a local environment has a determinant role in tuning the chemical reactivity of the metal, ultimately contributing to the functional properties of the whole system. The database search tool, which we called MetalS(3) (Metal Sites Similarity Search), can be accessed through a Web interface at http://metalweb.cerm.unifi.it/tools/metals3/ . MetalS(3) uses a suitably adapted version of an algorithm that we previously developed to systematically compare the structure of the query metal site with each MFS in MetalPDB. For each MFS, the best superposition is kept. All these superpositions are then ranked according to the MetalS(3) scoring function and are presented to the user in tabular form. The user can interact with the output Web page to visualize the structural alignment or the sequence alignment derived from it. Options to filter the results are available. Test calculations show that the MetalS(3) output correlates well with expectations from protein homology considerations. Furthermore, we describe some usage scenarios that highlight the usefulness of MetalS(3) to obtain mechanistic and functional hints regardless of homology.

Experimental Phase Equilibria Studies of the Pb-Fe-O System in Air, in Equilibrium with Metallic Lead and at Intermediate Oxygen Potentials

Science.gov (United States)

Shevchenko, M.; Jak, E.

2017-12-01

The phase equilibria information on the Pb-Fe-O system is of practical importance for the improvement of the existing thermodynamic database of lead-containing slag systems (Pb-Zn-Fe-Cu-Si-Ca-Al-Mg-O). Phase equilibria of the Pb-Fe-O system have been investigated: (a) in air at temperatures between 1053 K and 1373 K (780 °C and 1100 °C); (b) in equilibrium with metallic lead at temperatures between 1053 K and 1373 K (780 °C and 1100 °C); and (c) at intermediate oxidation conditions for the liquid slag in equilibrium with two solids (spinel + magnetoplumbite), at temperatures between 1093 K and 1373 K (820 °C and 1100 °C). The high-temperature equilibration/quenching/electron probe X-ray microanalysis technique has been used to accurately determine the compositions of the phases in equilibrium in the system. The Pb and Fe concentrations in the phases were determined directly; preliminary thermodynamic modeling with FactSage was used to estimate the ferrous-to-ferric ratios and to present the results in the ternary diagram.

Persistent Microvascular Obstruction After Myocardial Infarction Culminates in the Confluence of Ferric Iron Oxide Crystals, Proinflammatory Burden, and Adverse RemodelingCLINICAL PERSPECTIVE

Energy Technology Data Exchange (ETDEWEB)

Kali, Avinash; Cokic, Ivan; Tang, Richard; Dohnalkova, Alice; Kovarik, Libor; Yang, Hsin-Jung; Kumar, Andreas; Prato, Frank S.; Wood, John C.; Underhill, David; Marban, Eduardo; Dharmakumar, Rohan

2016-11-01

Emerging evidence now supports the notion that persistent microvascular obstruction (PMO) may be more predictive of major adverse cardiovascular events than MI size itself. But, how PMO, a phenomenon limited to the acute/sub-acute period of MI, imparts adverse remodeling throughout the post MI period, particularly after its resolution, is incompletely understood. We hypothesized that PMOs resolve into chronic iron crystals within MI territories and actively impart a proinflammatory burden and adverse remodeling of infarction and LV in the chronic phase of MI. Canine models reperfused (n=20) and non-reperfused (n=20) with and without PMO were studied with serial cardiac MRI to characterize the spatiotemporal relationships between PMO, iron deposition, and infarct and LV remodeling indices between acute (day 7, post MI) and chronic (week 8, post MI). Histopathology and immunohistochemistry were used to validate the iron deposition, microscopically map and quantify the relationship between iron-rich chronic MI regions against pro-inflammatory macrophages, proinflammatory cytokines and matrix metalloproteinase. Atomic resolution transmission electron microscopy (TEM) was used to determine the crystallinity of iron and assess the physical effects of iron on lysosomes within macrophages, and energy-dispersive X-ray spectroscopy (EDS) to identify the chemical composition of the iron composite. Results showed that PMOs lead to iron deposition within chronic MI and that the extent of chronic iron deposition is strongly related to PMO Volume (r>0.6, p<0.001). TEM and EDS analysis showed that iron within chronic MI is found within macrophages as aggregates of nanocrystals of ~2.5 nm diameter in ferric state. Correlative histological studies showed that iron content, proinflammatory burden and collagen degrading enzyme were highly correlated (r >0.7, p<0.001). Iron within chronic MI was significantly associated with infarct resorption (r>0.5, p<0.001) and adverse structural (r

Wash water waste pretreatment system study

Science.gov (United States)

1976-01-01

The use of real wash water had no adverse effect on soap removal when an Olive Leaf soap based system was used; 96 percent of the soap was removed using ferric chloride. Numerous chemical agents were evaluated as antifoams for synthetic wash water. Wash water surfactants used included Olive Leaf Soap, Ivory Soap, Neutrogena and Neutrogena Rain Bath Gel, Alipal CO-436, Aerosol 18, Miranol JEM, Palmeto, and Aerosol MA-80. For each type of soapy wash water evaluated, at least one antifoam capable of causing nonpersistent foam was identified. In general, the silicones and the heavy metal ions (i.e., ferric, aluminum, etc.) were the most effective antifoams. Required dosage was in the range of 50 to 200 ppm.

Recent Advances in Antimicrobial Hydrogels Containing Metal Ions and Metals/Metal Oxide Nanoparticles

Directory of Open Access Journals (Sweden)

Fazli Wahid

2017-11-01

Full Text Available Recently, the rapid emergence of antibiotic-resistant pathogens has caused a serious health problem. Scientists respond to the threat by developing new antimicrobial materials to prevent or control infections caused by these pathogens. Polymer-based nanocomposite hydrogels are versatile materials as an alternative to conventional antimicrobial agents. Cross-linking of polymeric materials by metal ions or the combination of polymeric hydrogels with nanoparticles (metals and metal oxide is a simple and effective approach for obtaining a multicomponent system with diverse functionalities. Several metals and metal oxides such as silver (Ag, gold (Au, zinc oxide (ZnO, copper oxide (CuO, titanium dioxide (TiO2 and magnesium oxide (MgO have been loaded into hydrogels for antimicrobial applications. The incorporation of metals and metal oxide nanoparticles into hydrogels not only enhances the antimicrobial activity of hydrogels, but also improve their mechanical characteristics. Herein, we summarize recent advances in hydrogels containing metal ions, metals and metal oxide nanoparticles with potential antimicrobial properties.

The new generation of intravenous iron: chemistry, pharmacology, and toxicology of ferric carboxymaltose.

Science.gov (United States)

Funk, Felix; Ryle, Peter; Canclini, Camillo; Neiser, Susann; Geisser, Peter

2010-01-01

An ideal preparation for intravenous iron replacement therapy should balance effectiveness and safety. Compounds that release iron rapidly tend to cause toxicity, while large molecules can induce antibody formation and cause anaphylactic reactions. There is therefore a need for an intravenous iron preparation that delivers appropriate amounts of iron in a readily available form but with minimal side effects and thus with an excellent safety profile. In this paper, a review is given on the chemistry, pharmacology, and toxicology of ferric carboxymaltose (FCM, Ferinject), a stable and robust complex formulated as a colloidal solution with a physiological pH. The complex is gradually taken up mainly from the hepatic reticulo-endothelial system (RES), followed by effective delivery of iron to the endogeneous transport system for the haem synthesis in new erythrocytes, as shown in studies on the pharmacodynamics and pharmacokinetics with radio-labelled FCM. Studies with radio-labelled FCM also demonstrated a barrier function of the placenta and a low transfer of iron into the milk of lactating rats. Safety pharmacology studies indicated a favourable profile with regard to cardiovascular, central nervous, respiratory, and renal toxicity. A high maximum non-lethal dose was demonstrated in the single-dose toxicity studies. Furthermore, based on the No-Observed-Adverse-Effect-Levels (NOAELs) found in repeated-dose toxicity studies and on the cumulative doses administered, FCM has good safety margins. Reproductive and developmental toxicity studies did not reveal any direct or indirect harmful effects. No genotoxic potential was found in in vitro or in vivo studies. Moreover, antigenicity studies showed no cross-reactivity of FMC with anti-dextran antibodies and also suggested that FCM does not possess sensitizing potential. Lastly, no evidence of irritation was found in local tolerance studies with FCM. This excellent toxicity profile and the high effectiveness of FCM allow

Effect of ammonium and nitrate on ferric chelate reductase and nitrate reductase in Vaccinium species.

Science.gov (United States)

Poonnachit, U; Darnell, R

2004-04-01

Most Vaccinium species have strict soil requirements for optimal growth, requiring low pH, high iron availability and nitrogen primarily in the ammonium form. These soils are limited and are often located near wetlands. Vaccinium arboreum is a wild species adapted to a wide range of soils, including high pH, low iron, and nitrate-containing soils. This broader soil adaptation in V. arboreum may be related to increased efficiency of iron or nitrate uptake compared with the cultivated Vaccinium species. Nitrate, ammonium and iron uptake, and nitrate reductase (NR) and ferric chelate reductase (FCR) activities were compared in two Vaccinium species grown hydroponically in either nitrate or ammonia, with or without iron. The species studied were the wild V. arboreum and the cultivated V. corymbosum interspecific hybrid, which exhibits the strict soil requirements of most Vaccinium species. Ammonium uptake was significantly greater than nitrate uptake in both species, while nitrate uptake was greater in the wild species, V. arboreum, compared with the cultivated species, V. corymbosum. The increased nitrate uptake in V. arboreum was correlated with increased root NR activity compared with V. corymbosum. The lower nitrate uptake in V. corymbosum was reflected in decreased plant dry weight in this species compared with V. arboreum. Root FCR activity increased significantly in V. corymbosum grown under iron-deficient conditions, compared with the same species grown under iron-sufficient conditions or with V. arboreum grown under either iron condition. V. arboreum appears to be more efficient in acquiring nitrate compared with V. corymbosum, possibly due to increased NR activity and this may partially explain the wider soil adaptation of V. arboreum.

Heterogeneous catalytic ozonation of biologically pretreated Lurgi coal gasification wastewater using sewage sludge based activated carbon supported manganese and ferric oxides as catalysts.

Science.gov (United States)

Zhuang, Haifeng; Han, Hongjun; Hou, Baolin; Jia, Shengyong; Zhao, Qian

2014-08-01

Sewage sludge of biological wastewater treatment plant was converted into sewage sludge based activated carbon (SBAC) with ZnCl₂ as activation agent, which supported manganese and ferric oxides as catalysts (including SBAC) to improve the performance of ozonation of real biologically pretreated Lurgi coal gasification wastewater. The results indicated catalytic ozonation with the prepared catalysts significantly enhanced performance of pollutants removal and the treated wastewater was more biodegradable and less toxic than that in ozonation alone. On the basis of positive effect of higher pH and significant inhibition of radical scavengers in catalytic ozonation, it was deduced that the enhancement of catalytic activity was responsible for generating hydroxyl radicals and the possible reaction pathway was proposed. Moreover, the prepared catalysts showed superior stability and most of toxic and refractory compounds were eliminated at successive catalytic ozonation runs. Thus, the process with economical, efficient and sustainable advantages was beneficial to engineering application. Copyright © 2014 Elsevier Ltd. All rights reserved.

Comparative evaluation of post-column free radical scavenging and ferric reducing antioxidant power assays for screening of antioxidants in strawberries.

Science.gov (United States)

Raudonis, Raimondas; Raudone, Lina; Jakstas, Valdas; Janulis, Valdimaras

2012-04-13

ABTS and FRAP post-column techniques evaluate the antioxidant characteristics of HPLC separated compounds with specific reagents. ABTS characterize their ability to scavenge free radicals by electron-donating antioxidants, resulting in the absorbance decrease of the chromophoric radical. FRAP - is based on the reduction of Fe(III)-tripyridyltriazine complex to Fe(II)-tripyridyltriazine at low pH by electron-donating antioxidants, resulting in an absorbance increase. Both post-column assays were evaluated and compared according to the following validation parameters: specificity, precision, limit of detection (LoD), limit of quantitation (LoQ) and linearity. ABTS and FRAP post-column assays were specific, repeatable and sensitive and thus can be used for the evaluation of antioxidant active compounds. Antioxidant active compounds were quantified according to TEAC for each assay and ABTS/FRAP ratio was derived. No previous records of antioxidative activity of leaves and fruits of strawberries (Fragaria viridis, Fragaria moschata) research have been found. The research results confirm the reliability of ABTS and FRAP post-column assays for screening of antioxidants in complex mixtures and the determination of radical scavenging and ferric reducing ability by their TEAC values. Copyright © 2012 Elsevier B.V. All rights reserved.

The Role of Intermediates in the Process of Red Ferric Pigment Manufacture from FeSO4.7H2O

International Nuclear Information System (INIS)

Zboril, Radek; Mashlan, Miroslav; Petridis, Dimitris; Krausova, Dagmar; Pikal, Petr

2002-01-01

One method of industrial manufacture of red ferric pigments is based on the thermal decomposition of FeSO 4 .7H 2 O into α-Fe 2 O 3 (copperas red). The difficult reproducibility of the color quality of the final pigment is the main problem of this process. One of the factors that can influence the pigment color is contamination by some of the intermediates formed during the transformation process. The identification of two groups of intermediates is the basic result of an extensive laboratory investigation carried out using 57 Fe Moessbauer spectroscopy and X-ray powder diffraction (XRD). The first group of intermediates includes sulfato-phases as FeSO 4 .H 2 O, FeSO 4 , Fe(OH)SO 4 , Fe 2 O(SO 4 ) 2 , Fe 2 O(SO 4 ) 2 .xH 2 O x element of (0,1), and Fe 2 (SO 4 ) 3 . Thermally metastable polymorphs of iron(III) oxide, β-Fe 2 O 3 , γ-Fe 2 O 3 and ε-Fe 2 O 3 , represent the other group. Moessbauer characterization of all intermediate products is given. A significant influence of β-Fe 2 O 3 on the pigment color was found.

A hydrogen-ferric ion rebalance cell operating at low hydrogen concentrations for capacity restoration of iron-chromium redox flow batteries

Science.gov (United States)

Zeng, Y. K.; Zhao, T. S.; Zhou, X. L.; Zou, J.; Ren, Y. X.

2017-06-01

To eliminate the adverse impacts of hydrogen evolution on the capacity of iron-chromium redox flow batteries (ICRFBs) during the long-term operation and ensure the safe operation of the battery, a rebalance cell that reduces the excessive Fe(III) ions at the positive electrolyte by using the hydrogen evolved from the negative electrolyte is designed, fabricated and tested. The effects of the flow field, hydrogen concentration and H2/N2 mixture gas flow rate on the performance of the hydrogen-ferric ion rebalance cell have been investigated. Results show that: i) an interdigitated flow field based rebalance cell delivers higher limiting current densities than serpentine flow field based one does; ii) the hydrogen utilization can approach 100% at low hydrogen concentrations (≤5%); iii) the apparent exchange current density of hydrogen oxidation reaction in the rebalance cell is proportional to the square root of the hydrogen concentration at the hydrogen concentration from 1.3% to 50%; iv) a continuous rebalance process is demonstrated at the current density of 60 mA cm-2 and hydrogen concentration of 2.5%. Moreover, the cost analysis shows that the rebalance cell is just approximately 1% of an ICRFB system cost.

Nanofabrication and Electrochemical Characterization of Self- Assembled Monolayers Sandwiched between Metal Nanoparticles and Electrode Surfaces

Science.gov (United States)

Cea, Pilar; Martín, Santiago; Gonza´lez-Orive, Alejandro; Osorio, Henrry M.; Quintín, Pablo; Herrer, Lucía

2016-01-01

Nanoscience and nanotechnology have reached the syllabi of many upper-division undergraduate and master level courses all over the world. There is therefore a growing need for practical exercises that illustrate the fabrication, characterization, properties, and applications of nanomaterials. Here we describe an advanced-level laboratory…

Cost-effectiveness analysis of ferric carboxymaltose in iron-deficient patients with chronic heart failure in Sweden.

Science.gov (United States)

Hofmarcher, Thomas; Borg, Sixten

2015-01-01

Iron deficiency is a common but treatable comorbidity in chronic heart failure (CHF) that is associated with impaired health-related quality-of-life (HRQoL). This study evaluates the cost-effectiveness of the intravenous iron preparation ferric carboxymaltose (FCM) for the treatment of iron deficiency in CHF from a Swedish healthcare perspective. A cost-effectiveness analysis with a time horizon of 24 weeks was performed to compare FCM treatment with placebo. Data on health outcomes and medical resource use were mainly taken from the FAIR-HF trial and combined with Swedish cost data. An incremental cost-effectiveness ratio (ICER) was calculated as well as the change in per-patient costs for primary care and hospital care. In the FCM group compared with placebo, quality-adjusted life years (QALYs) are higher (difference = 0.037 QALYs), but so are per-patient costs [(difference = SEK 2789 (€303)]. Primary care and hospital care equally share the additional costs, but within hospitals there is a major shift of costs from inpatient care to outpatient care. The ICER is SEK 75,389 (€8194) per QALY. The robustness of the result is supported by sensitivity analyses. Treatment of iron deficiency in CHF with FCM compared with placebo is estimated to be cost-effective. The ICER in the base case scenario is twice as high as previously thought, but noticeably below SEK 500,000 (€54,300) per QALY, an informal average reference value used by the Swedish Dental and Pharmaceutical Benefits Agency. Increased HRQoL and fewer hospitalizations are the key drivers of this result.

Extraction process for removing metallic impurities from alkalide metals

Science.gov (United States)

Royer, Lamar T.

1988-01-01

A development is described for removing metallic impurities from alkali metals by employing an extraction process wherein the metallic impurities are extracted from a molten alkali metal into molten lithium metal due to the immiscibility of the alkali metals in lithium and the miscibility of the metallic contaminants or impurities in the lithium. The purified alkali metal may be readily separated from the contaminant-containing lithium metal by simple decanting due to the differences in densities and melting temperatures of the alkali metals as compared to lithium.

Metal-metal-hofteproteser

DEFF Research Database (Denmark)

Ulrich, Michael; Overgaard, Søren; Penny, Jeannette

2014-01-01

In Denmark 4,456 metal-on-metal (MoM) hip prostheses have been implanted. Evidence demonstrates that some patients develope adverse biological reactions causing failures of MoM hip arthroplasty. Some reactions might be systemic. Failure rates are associated with the type and the design of the Mo...

Effects of ferric iron reduction and regeneration on nitrous oxide and methane emissions in a rice soil.

Science.gov (United States)

Huang, Bin; Yu, Kewei; Gambrell, Robert P

2009-01-01

A laboratory soil slurry experiment and an outdoor pot experiment were conducted to study effects of ferric iron (Fe(III)) reduction and regeneration on nitrous oxide (N(2)O) and methane (CH(4)) emissions in a rice (Oryza sativa L.) soil. The anoxic slurry experiment showed that enhancing microbial Fe(III) reduction by ferrihydrite amendment (40 mol Fe g(-1)) transitionally stimulated N(2)O production and lowered CH(4) production by 16% during an initial 33-day incubation. Increased regeneration of Fe(III) through a 4-day aeration period in the Fe-amended slurry compared to the control slurry reduced CH(4) emission by 30% in the subsequent 15-day anaerobic incubation. The pot experiment showed that ferrihydrite amendment (63 micromol Fe g(-1)) stimulated N(2)O fluxes in the days following flooding. The Fe amendment suppression on CH(4) emission was obscured in the early season but became significant upon reflooding in the mid- and late-seasons. As a result, seasonal CH(4) emission in Fe-amended pots was 26% lower than the control with a single 2-day drainage and 69% lower with a double 2-day drainage. The reduction in CH(4) emission upon reflooding from the Fe-amended pots was mainly attributed to the increased Fe(III) regeneration during drainage showing a mechanism of Fe(III) regeneration in mitigating CH(4) emission by short-term drainage in flooded soils.

Vertically grown zinc oxide nanorods functionalized with ferric oxide for in vivo and non-enzymatic glucose detection

Science.gov (United States)

Marie, Mohammed; Manoharan, Anishkumar; Kuchuk, Andrian; Ang, Simon; Manasreh, M. O.

2018-03-01

An enzyme-free glucose sensor based on vertically grown zinc oxide nanorods (NRs) functionalized with ferric oxide (Fe2O3) is investigated. The well-aligned and high density ZnO NRs were synthesized on an FTO/glass substrate by a sol-gel and hydrothermal growth method. A dip-coating technique was utilized to modify the surface of the as-grown ZnO NRs with Fe2O3. The immobilized surface was coated with a layer of nafion membrane. The fabricated glucose sensor was characterized amperometrically at room temperature using three electrodes stationed in the phosphate buffer solution, where ZnO NRs/Fe2O3/nafion membrane was the sensing or working electrode, and platinum plate and silver/silver chloride were used as the counter and reference electrodes, respectively. The proposed non-enzymatic and modified glucose sensor exhibited a high sensitivity in the order of 0.052 μA cm-2 (mg/dL)-1, a lower detection limit of around 0.95 mmol L-1, a sharp and fast response time of ˜1 s, and a linear response to changes in glucose concentrations from 100-400 mg dL-1. The linear amperometric response of the sensor covers the physiological and clinical interest of glucose levels for diabetic patients. The device continues to function accurately after multiple measurements with a good reproducibility. The proposed glucose sensor is expected to be used clinically for in vivo monitoring of glucose.

Harmful algal bloom removal and eutrophic water remediation by commercial nontoxic polyamine-co-polymeric ferric sulfate-modified soils.

Science.gov (United States)

Dai, Guofei; Zhong, Jiayou; Song, Lirong; Guo, Chunjing; Gan, Nanqin; Wu, Zhenbin

2015-07-01

Harmful algal bloom has posed great threat to drinking water safety worldwide. In this study, soils were combined with commercial nontoxic polyamine poly(epichlorohydrin-dimethylamine) (PN) and polymeric ferric sulfate (PFS) to obtain PN-PFS soils for Microcystis removal and eutrophic water remediation under static laboratory conditions. High pH and temperature in water could enhance the function of PN-PFS soil. Algal removal efficiency increased as soil particle size decreased or modified soil dose increased. Other pollutants or chemicals (such as C, P, and organic matter) in eutrophic water could participate and promote algal removal by PN-PFS soil; these pollutants were also flocculated. During PN-PFS soil application in blooming field samples, the removal efficiency of blooming Microcystis cells exceeded 99 %, the cyanotoxin microcystins reduced by 57 %. Water parameters (as TP, TN, SS, and SPC) decreased by about 90 %. CODMn, PO4-P, and NH4-N also sharply decreased by >45 %. DO and ORP in water improved. Netting and bridging effects through electrostatic attraction and complexation reaction could be the two key mechanisms of Microcystis flocculation and pollutant purification. Considering the low cost of PN-PFS soil and its nontoxic effect on the environment, we proposed that this soil combination could be applied to remove cyanobacterial bloom and remediate eutrophic water in fields.

Mid-infrared and near-infrared spectroscopic study of selected magnesium carbonate minerals containing ferric iron-Implications for the geosequestration of greenhouse gases.

Science.gov (United States)

Frost, Ray L; Reddy, B Jagannadha; Bahfenne, Silmarilly; Graham, Jessica

2009-04-01

The proposal to remove greenhouse gases by pumping liquefied CO(2) several kilometres below the ground implies that many carbonate containing minerals will be formed. Among these minerals brugnatellite and coalingite are probable. Two ferric ion bearing minerals brugnatellite and coalingite with a hydrotalcite-like structure have been characterised by a combination of infrared and near-infrared (NIR) spectroscopy. The infrared spectra of the OH stretching region are characterised by OH and water stretching vibrations. Both the first and second fundamental overtones of these bands are observed in the NIR spectra in the 7030-7235 cm(-1) and 10,490-10,570 cm(-1) regions. Intense (CO(3))(2-) symmetric and antisymmetric stretching vibrations support the concept that the carbonate ion is distorted. The position of the water bending vibration indicates the water is strongly hydrogen bonded in the mineral structure. Split NIR bands at around 8675 and 11,100 cm(-1) indicate that some replacement of magnesium ions by ferrous ions in the mineral structure has occurred. Near-infrared spectroscopy is ideal for the assessment of the formation of carbonate minerals.

Technologies for Extracting Valuable Metals and Compounds from Geothermal Fluids

Energy Technology Data Exchange (ETDEWEB)

Harrison, Stephen [SIMBOL Materials

2014-04-30

Executive Summary Simbol Materials studied various methods of extracting valuable minerals from geothermal brines in the Imperial Valley of California, focusing on the extraction of lithium, manganese, zinc and potassium. New methods were explored for managing the potential impact of silica fouling on mineral extraction equipment, and for converting silica management by-products into commercial products.` Studies at the laboratory and bench scale focused on manganese, zinc and potassium extraction and the conversion of silica management by-products into valuable commercial products. The processes for extracting lithium and producing lithium carbonate and lithium hydroxide products were developed at the laboratory scale and scaled up to pilot-scale. Several sorbents designed to extract lithium as lithium chloride from geothermal brine were developed at the laboratory scale and subsequently scaled-up for testing in the lithium extraction pilot plant. Lithium The results of the lithium studies generated the confidence for Simbol to scale its process to commercial operation. The key steps of the process were demonstrated during its development at pilot scale: 1. Silica management. 2. Lithium extraction. 3. Purification. 4. Concentration. 5. Conversion into lithium hydroxide and lithium carbonate products. Results show that greater than 95% of the lithium can be extracted from geothermal brine as lithium chloride, and that the chemical yield in converting lithium chloride to lithium hydroxide and lithium carbonate products is greater than 90%. The product purity produced from the process is consistent with battery grade lithium carbonate and lithium hydroxide. Manganese and zinc Processes for the extraction of zinc and manganese from geothermal brine were developed. It was shown that they could be converted into zinc metal and electrolytic manganese dioxide after purification. These processes were evaluated for their economic potential, and at the present time Simbol

Mercury, monomethyl mercury, and dissolved organic carbon concentrations in surface water entering and exiting constructed wetlands treated with metal-based coagulants, Twitchell Island, California

Science.gov (United States)

Stumpner, Elizabeth B.; Kraus, Tamara E.C.; Fleck, Jacob A.; Hansen, Angela M.; Bachand, Sandra M.; Horwath, William R.; DeWild, John F.; Krabbenhoft, David P.; Bachand, Philip A.M.

2015-09-02

Coagulation with metal-based salts is a practice commonly employed by drinking-water utilities to decrease particle and dissolved organic carbon concentrations in water. In addition to decreasing dissolved organic carbon concentrations, the effectiveness of iron- and aluminum-based coagulants for decreasing dissolved concentrations both of inorganic and monomethyl mercury in water was demonstrated in laboratory studies that used agricultural drainage water from the Sacramento–San Joaquin Delta of California. To test the effectiveness of this approach at the field scale, nine 15-by-40‑meter wetland cells were constructed on Twitchell Island that received untreated water from island drainage canals (control) or drainage water treated with polyaluminum chloride or ferric sulfate coagulants. Surface-water samples were collected approximately monthly during November 2012–September 2013 from the inlets and outlets of the wetland cells and then analyzed by the U.S. Geological Survey for total concentrations of mercury and monomethyl mercury in filtered (less than 0.3 micrometers) and suspended-particulate fractions and for concentrations of dissolved organic carbon.

Magnetic particles

Science.gov (United States)

Chang, Manchium (Inventor); Colvin, Michael S. (Inventor)

1989-01-01

Magnetic polymer particles are formed by swelling porous, polymer particles and impregnating the particles with an aqueous solution of precursor magnetic metal salt such as an equimolar mixture of ferrous chloride and ferric chloride. On addition of a basic reagent such as dilute sodium hydroxide, the metal salts are converted to crystals of magnetite which are uniformly contained througout the pores of the polymer particle. The magnetite content can be increased and neutral buoyancy achieved by repetition of the impregnaton and neutralization steps to adjust the magnetite content to a desired level.

Metal-on-metal hip joint tribology.

Science.gov (United States)

Dowson, D; Jin, Z M

2006-02-01

The basic tribological features of metal-on-metal total hip replacements have been reviewed to facilitate an understanding of the engineering science underpinning the renaissance of these hard-on-hard joints. Metal-on-polymer hip replacements operate in the boundary lubrication regime, thus leading to the design guidance to reduce the femoral head diameter as much as is feasible to minimize frictional torque and volumetric wear. This explains why the gold-standard implant of this form from the past half-century had a diameter of only 22.225 mm (7/8 in). Metal-on-metal implants can operate in the mild mixed lubrication regime in which much of the applied load is supported by elastohydrodynamic films. Correct tribological design leads to remarkably low steady state wear rates. Promotion of the most effective elastohydrodynamic films calls for the largest possible head diameters and the smallest clearances that can reasonably be adopted, consistent with fine surface finishes, good sphericity and minimal structural elastic deformation of the cup on its foundations. This guidance, which is opposite in form to that developed for metal-on-polymer joints, is equally valid for solid (monolithic) metallic heads on metallic femoral stems and surface replacement femoral shells. Laboratory measurements of friction and wear in metal-on-metal joints have confirmed their potential to achieve a very mild form of mixed lubrication. The key lies in the generation of effective elastohydrodynamic lubricating films of adequate thickness compared with the composite roughness of the head and cup. The calculation of the film thickness is by no means easy, but the full procedure is outlined and the use of an empirical formula that displays good agreement with calculations based upon the full numerical solutions is explained. The representation of the lambda ratio, lambda, embracing both film thickness and composite roughness, is described.

Sedimentibacter sp. With corrosive capability, Ferric-reducing, isolated from an oil separation tank

International Nuclear Information System (INIS)

Lopez-Jimenez, G.; Loera, O.; Ramirez, F.; Monroy, O.; Fernandez-Linares, L. C.

2009-01-01

Bio corrosion is a common problem in oil and gas industry facilities. characterization of the microbial populations responsible for bio corrosion and the interactions between different microorganisms with metallic surfaces is required in order to implemented efficient monitoring and control strategies. (Author)

Development of Surface Complexation Models of Cr(VI) Adsorption on Soils, Sediments and Model Mixtures of Kaolinite, Montmorillonite, γ-Alumina, Hydrous Manganese and Ferric Oxides and Goethite

Energy Technology Data Exchange (ETDEWEB)

Koretsky, Carla [Western Michigan University

2013-11-29

Hexavalent chromium is a highly toxic contaminant that has been introduced into aquifers and shallow sediments and soils via many anthropogenic activities. Hexavalent chromium contamination is a problem or potential problem in the shallow subsurface at several DOE sites, including Hanford, Idaho National Laboratory, Los Alamos National Laboratory and the Oak Ridge Reservation (DOE, 2008). To accurately quantify the fate and transport of hexavalent chromium at DOE and other contaminated sites, robust geochemical models, capable of correctly predicting changes in chromium chemical form resulting from chemical reactions occurring in subsurface environments are needed. One important chemical reaction that may greatly impact the bioavailability and mobility of hexavalent chromium in the subsurface is chemical binding to the surfaces of particulates, termed adsorption or surface complexation. Quantitative thermodynamic surface complexation models have been derived that can correctly calculate hexavalent chromium adsorption on well-characterized materials over ranges in subsurface conditions, such pH and salinity. However, models have not yet been developed for hexavalent chromium adsorption on many important constituents of natural soils and sediments, such as clay minerals. Furthermore, most of the existing thermodynamic models have been developed for relatively simple, single solid systems and have rarely been tested for the complex mixtures of solids present in real sediments and soils. In this study, the adsorption of hexavalent chromium was measured as a function of pH (3-10), salinity (0.001 to 0.1 M NaNO3), and partial pressure of carbon dioxide(0-5%) on a suite of naturally-occurring solids including goethite (FeOOH), hydrous manganese oxide (MnOOH), hydrous ferric oxide (Fe(OH)3), γ-alumina (Al2O3), kaolinite (Al2Si2O5(OH)4), and montmorillonite (Na3(Al, Mg)2Si4O10(OH)2-nH2O). The results show that all of these materials can bind substantial quantities of

Arsenic Adsorption Equilibrium Concentration and Adsorption Rate of Activated Carbon Coated with Ferric-Aluminum Hydroxides

Science.gov (United States)

Zhang, M.; Sugita, H.; Oguma, T.; Hara, J.; Takahashi, S.

2015-12-01

In some areas of developing countries, ground or well water contaminated with arsenic has been reluctantly used as drinking water. It is highly desirable that effective and inexpensive arsenic removal agents should be developed and provided to reduce the potential health risk. Previous studies demonstrated that activated carbon coated with ferric-aluminum hydroxides (Fe-Al-C) has high adsorptive potential for removal of arsenic. In this study, a series of experiments using Fe-Al-C were carried to discuss adsorption equilibrium time, adsorption equilibrium concentration and adsorption rate of arsenic for Fe-Al-C. Fe-Al-C used in this study was provided by Astec Co., Ltd. Powder reagent of disodium hydrogen arsenate heptahydrate was dissolved into ion-exchanged water. The solution was then further diluted with ion-exchanged water to be 1 and 10 mg/L as arsenic concentration. The pH of the solution was adjusted to be around 7 by adding HCl and/or NaOH. The solution was used as artificial arsenic contaminated water in two types of experiments (arsenic adsorption equilibrium and arsenic adsorption rate tests). The results of the arsenic equilibrium tests were showed that a time period of about 3 days to reach apparent adsorption equilibrium for arsenic. The apparent adsorption equilibrium concentration and adsorbed amount of arsenic on Fe-Al-C adsorbent could be estimated by application of various adsorption isotherms, but the distribution coefficient of arsenic between solid and liquid varies with experimental conditions such as initial concentration of arsenic and addition concentration of adsorbent. An adsorption rate equation that takes into account the reduction in the number of effective adsorption sites on the adsorbent caused by the arsenic adsorption reaction was derived based on the data obtained from the arsenic adsorption rate tests.

ELECTRODEPOSITION OF NICKEL ON URANIUM

Science.gov (United States)

Gray, A.G.

1958-08-26

A method is described for preparing uranium objects prior to nickel electroplating. The process consiats in treating the surface of the uranium with molten ferric chloride hexahydrate, at a slightiy elevated temperature. This treatment etches the metal surface providing a structure suitable for the application of adherent electrodeposits and at the same time plates the surface with a thin protective film of iron.

Predicting dietborne metal toxicity from metal influxes

Science.gov (United States)

Croteau, M.-N.; Luoma, S.N.

2009-01-01

Dietborne metal uptake prevails for many species in nature. However, the links between dietary metal exposure and toxicity are not well understood. Sources of uncertainty include the lack of suitable tracers to quantify exposure for metals such as copper, the difficulty to assess dietary processes such as food ingestion rate, and the complexity to link metal bioaccumulation and effects. We characterized dietborne copper, nickel, and cadmium influxes in a freshwater gastropod exposed to diatoms labeled with enriched stable metal isotopes. Metal influxes in Lymnaea stagnalis correlated linearly with dietborne metal concentrations over a range encompassing most environmental exposures. Dietary Cd and Ni uptake rate constants (kuf) were, respectively, 3.3 and 2.3 times higher than that for Cu. Detoxification rate constants (k detox) were similar among metals and appeared 100 times higher than efflux rate constants (ke). Extremely high Cu concentrations reduced feeding rates, causing the relationship between exposure and influx to deviate from linearity; i.e., Cu uptake rates leveled off between 1500 and 1800 nmol g-1 day-1. L. stagnalis rapidly takes up Cu, Cd, and Ni from food but detoxifies the accumulated metals, instead of reducing uptake or intensifying excretion. Above a threshold uptake rate, however, the detoxification capabilities of L. stagnalis are overwhelmed.

Metal Matrix Composite Solar Cell Metallization

Directory of Open Access Journals (Sweden)

Wilt David M.

2017-01-01

Full Text Available Advanced solar cells are moving to ever thinner formats in order to save mass and in some cases improve performance. As cells are thinned, the possibility that they may fracture or cleave due to mechanical stresses is increased. Fractures of the cell can degrade the overall device performance if the fracture propagates through the contact metallization, which frequently occurs. To address this problem, a novel semiconductor metallization system based on multi-walled carbon nanotube (CNT reinforcement, termed metal matrix composite (MMC metallization is under investigation. Electro-mechanical characterization of MMC films demonstrate their ability to provide electrical conductivity over >40 micron wide cracks in the underlying semiconductor, with the carbon nanotubes bridging the gap. In addition, these materials show a “self-healing” behaviour, electrically reconnecting at ~30 microns when strained past failure. Triple junction (TJ space cells with MMC metallization demonstrated no loss in Jsc after intentional fracture, whereas TJ cells with conventional metallization suffer up to 50% Jsc loss.

Method of producing homogeneous mixed metal oxides and metal-metal oxide mixtures

International Nuclear Information System (INIS)

1980-01-01

Finely divided powders are prepared by first reacting an aqueous solution containing dissolved metal values with excess urea. After the reaction of water in the solution with urea is complete, the resulting molten urea solution is heated to cause metal values in solution to precipitate. The resulting mixture containing precipitated metal values is heated to evaporate volatile material, leaving a dry powder containing the metal values. Detailed examples are given. (U.K.)

Fluorescent sensors based on quinoline-containing styrylcyanine: determination of ferric ions, hydrogen peroxide, and glucose, pH-sensitive properties and bioimaging.

Science.gov (United States)

Yang, Xiaodong; Zhao, Peiliang; Qu, Jinqing; Liu, Ruiyuan

2015-08-01

A novel styrylcyanine-based fluorescent probe 1 was designed and synthesized via facile methods. Ferric ions quenched the fluorescence of probe 1, whereas the addition of ferrous ions led to only small changes in the fluorescence signal. When hydrogen peroxide was introduced into the solution containing probe 1 and Fe(2+) , Fe(2+) was oxidized to Fe(3+), resulting in the quenching of the fluorescence. The probe 1/Fe(2+) solution fluorescence could also be quenched by H2 O2 released from glucose oxidation by glucose oxidase (GOD), which means that probe 1/Fe(2+) platform could be used to detect glucose. Probe 1 is fluorescent in basic and neutral media but almost non-fluorescent in strong acidic environments. Such behaviour enables it to work as a fluorescent pH sensor in both the solution and solid states and as a chemosensor for detecting volatile organic compounds with high acidity and basicity. Subsequently, the fluorescence microscopic images of probe 1 in live cells and in zebrafish were achieved successfully, suggesting that the probe has good cell membrane permeability and a potential application for imaging in living cells and living organisms. Copyright © 2014 John Wiley & Sons, Ltd.

Determinants of quality of life of patients with heart failure and iron deficiency treated with ferric carboxymaltose: FAIR-HF sub-analysis.

Science.gov (United States)

Gutzwiller, Florian S; Pfeil, Alena M; Comin-Colet, Josep; Ponikowski, Piotr; Filippatos, Gerasimos; Mori, Claudio; Braunhofer, Peter G; Szucs, Thomas D; Schwenkglenks, Matthias; Anker, Stefan D

2013-10-09

Heart failure (HF) is a burden to patients and health care systems. The objectives of HF treatment are to improve health related quality of life (HRQoL) and reduce mortality and morbidity. We aimed to evaluate determinants of health-related quality of life (HRQoL) in patients with iron deficiency and HF treated with intravenous (i.v.) iron substitution or placebo. A randomised, double-blind, placebo-controlled trial (n = 459) in iron-deficient chronic heart failure (CHF) patients with or without anaemia studied clinical and HRQoL benefits of i.v. iron substitution using ferric carboxymaltose (FCM) over a 24-week trial period. Multivariate analysis was carried out with various clinical variables as independent variables and HRQoL measures as dependent variables. Mean change from baseline of European Quality of Life - 5 Dimensions (EQ-5D) (value set-based) utilities (on a 0 to 100 scale) at week 24 was 8.91 (i.v. iron) and 0.68 (placebo; p model remained stable. In this study, i.v. iron substitution, exercise tolerance, stroke, country of residence and renal function influenced measures of HRQoL in patients with heart failure and iron deficiency. © 2013.

Infection or metal hypersensitivity? The diagnostic challenge of failure in metal-on-metal bearings.

LENUS (Irish Health Repository)

Galbraith, John G

2011-04-01

The use of second generation metal-on-metal hip articulations has gained favour in the past few years. A hypersensitivity reaction to the metal-on-metal bearing, although rare, is a reported complication and is a novel mode of failure of these implants. Differentiating failure secondary to infection from failure secondary to metal hypersensitivity represents a significant diagnostic challenge. A retrospective review of all cases of hip arthroplasty using metal-on-metal bearings over a 5-year period at a tertiary referral centre identified 3 cases of failure secondary to metal hypersensitivity. Clinical presentation, serological markers, radiological imaging and histological analysis of all cases identified were evaluated. Histological analysis of periprosthetic tissue in all 3 cases identified characteristic features such as perivascular lymphocytic aggregates and chronic inflammation consistent with aseptic lymphocytic vasculitis-associated lesions (ALVAL). This study highlights that failure secondary to metal hypersensitivity must be considered in patients presenting with the reappearance of persistent pain, marked joint effusion, and the development of early osteolysis in the absence of infection.

Alkali metal and alkali metal hydroxide intercalates of the layered transition metal disulfides

International Nuclear Information System (INIS)

Kanzaki, Y.; Konuma, M.; Matsumoto, O.

1981-01-01

The intercalation reaction of some layered transition metal disulfides with alkali metals, alkali metal hydroxides, and tetraalkylammonium hydroxides were investigated. The alkali metal intercalates were prepared in the respective metal-hexamethylphosphoric triamide solutions in vaccuo, and the hydroxide intercalates in aqueous hydroxide solutions. According to the intercalation reaction, the c-lattice parameter was increased, and the increase indicated the expansion of the interlayer distance. In the case of alkali metal intercalates, the expansion of the interlayer distance increased continuously, corresponding to the atomic radius of the alkali metal. On the other hand, the hydroxide intercalates showed discrete expansion corresponding to the effective ionic radius of the intercalated cation. All intercalates of TaS 2 amd NbS 2 were superconductors. The expansion of the interlayer distance tended to increase the superconducting transition temperature in the intercalates of TaS 2 and vice versa in those of NbS 2 . (orig.)

The role of low-energy electrons in focused electron beam induced deposition: four case studies of representative precursors

Directory of Open Access Journals (Sweden)

Rachel M. Thorman

2015-09-01

Full Text Available Focused electron beam induced deposition (FEBID is a single-step, direct-write nanofabrication technique capable of writing three-dimensional metal-containing nanoscale structures on surfaces using electron-induced reactions of organometallic precursors. Currently FEBID is, however, limited in resolution due to deposition outside the area of the primary electron beam and in metal purity due to incomplete precursor decomposition. Both limitations are likely in part caused by reactions of precursor molecules with low-energy (3, Pt(PF34, Co(CO3NO, and W(CO6. Through these case studies, it is evident that this combination of studies can provide valuable insight into potential mechanisms governing deposit formation in FEBID. Although further experiments and new approaches are needed, these studies are an important stepping-stone toward better understanding the fundamental physics behind the deposition process and establishing design criteria for optimized FEBID precursors.

Quinoline-substituted Zinc(II) phthalocyanine for the dual detection of ferric and zinc ions

Energy Technology Data Exchange (ETDEWEB)

Gupta, Ankush [Lyallpur Khalsa College of Engineering, Jalandhar (India); Kim, A Rong [Dong-A University, Busan (Korea, Republic of); Kim, Kyung Sub; Na, Kun [The Catholic University, Seoul (Korea, Republic of); Choi, Myung Seok [Konkuk University, Seoul (Korea, Republic of); Park, Jong S. [Pusan National University, Busan (Korea, Republic of)

2015-09-15

Here we present the synthesis and properties of quinoline-substituted zinc(II) phthalocyanine, Zn[Pc(O-QN){sub 4} ]. Zn[Pc(O-QN){sub 4} ] can function as a highly selective chemosensor against Fe{sup 3+} and Zn{sup 2+} ions, exhibiting efficient fluorescence quenching and enhancement, respectively. Various characterization techniques were employed to investigate the intermolecular interactions of Zn[Pc(O-QN){sub 4} ] with metal ions. A double-electron exchange and a forbidden photoinduced electron transfer behavior in Zn[Pc(O-QN){sub 4} ] were attributed to such opposite responses. Furthermore, by taking advantage of selectivity, we successfully employed Zn[Pc(O-QN)-4 ] to stain and record confocal fluorescence microscopy images of Chang liver cells in the presence of metal ions.

Controlling Magnetic and Ferroelectric Order Through Geometry: Synthesis, Ab Initio Theory, Characterization of New Multi-Ferric Fluoride Materials

Energy Technology Data Exchange (ETDEWEB)

Halasyamani, Shiv [Univ. of Houston, TX (United States); Fennie, Craig [Cornell Univ., Ithaca, NY (United States)

2016-11-03

We have focused on the synthesis, characterization, and ab initio theory on multi-functional mixed-metal fluorides. With funding from the DOE, we have successfully synthesized and characterized a variety of mixed metal fluoride materials.

Coordination modes of tyrosinate-ligated catalase-type heme enzymes: magnetic circular dichroism studies of Plexaura homomalla allene oxide synthase, Mycobacterium avium ssp. paratuberculosis protein-2744c, and bovine liver catalase in their ferric and ferrous states.

Science.gov (United States)

Bandara, D M Indika; Sono, Masanori; Bruce, Grant S; Brash, Alan R; Dawson, John H

2011-12-01

Bovine liver catalase (BLC), catalase-related allene oxide synthase (cAOS) from Plexaura homomalla, and a recently isolated protein from the cattle pathogen Mycobacterium avium ssp. paratuberculosis (MAP-2744c (MAP)) are all tyrosinate-ligated heme enzymes whose crystal structures have been reported. cAOS and MAP have low (enzymes in their ferric and ferrous states using magnetic circular dichroism and UV-visible absorption spectroscopy. The MAP protein shows remarkable spectral similarities to cAOS and BLC in its native Fe(III) state, but clear differences from ferric proximal heme ligand His93Tyr Mb (myoglobin) mutant, which may be attributed to the presence of an Arg(+)-N(ω)-H···¯O-Tyr (proximal heme axial ligand) hydrogen bond in the first three heme proteins. Furthermore, the spectra of Fe(III)-CN¯, Fe(III)-NO, Fe(II)-NO (except for five-coordinate MAP), Fe(II)-CO, and Fe(II)-O(2) states of cAOS and MAP, but not H93Y Mb, are also similar to the corresponding six-coordinate complexes of BLC, suggesting that a tyrosinate (Tyr-O¯) is the heme axial ligand trans to the bound ligands in these complexes. The Arg(+)-N(ω)-H to ¯O-Tyr hydrogen bond would be expected to modulate the donor properties of the proximal tyrosinate oxyanion and, combined with the subtle differences in the catalytic site structures, affect the activities of cAOS, MAP and BLC. Copyright © 2011 Elsevier Inc. All rights reserved.

Application of liquid metals for the extraction of solid metals

International Nuclear Information System (INIS)

Borgstedt, H.U.

1996-01-01

Liquid metals dissolve several solid metals in considerable amounts at moderate temperatures. The dissolution processes may be based upon simple physical solubility, formation of intermetallic phases. Even chemical reactions are often observed in which non-metallic elements might be involved. Thus, the capacity to dissolve metals and chemical properties of the liquid metals play a role in these processes. Besides the solubility also chemical properties and thermochemical data are of importance. The dissolution of metals in liquid metals can be applied to separate the solutes from other metals or non-metallic phases. Relatively noble metals can be chemically reduced by the liquid phases. Such solution processes can be applied in the extractive metallurgy, for instance to extract metals from metallic waste. The recycling of metals is of high economical and ecological importance. Examples of possible processes are discussed. (author)

Near-field scanning optical microscopy based nanostructuring of glass

International Nuclear Information System (INIS)

Chimmalgi, A; Hwang, D J; Grigoropoulos, C P

2007-01-01

Nanofabrication, at lateral resolutions beyond the capability of conventional optical lithography techniques, is demonstrated here. Femtosecond laser was used in conjunction with Near-field Scanning Optical Microscopes (NSOMs) to nanostructure thin metal films. Also, the possibility of using these nanostructured metal films as masks to effectively transfer the pattern to the underlying substrate by wet etching process is shown. Two different optical nearfiled processing schemes were studied for near-field nanostructuring. In the first scheme, local field enhancement in the near-field of a scanning probe microscope (SPM) probe tip irradiated with femtosecond laser pulses was utilized (apertureless NSOM mode) and as a second approach, femtosecond laser beam was spatially confined by cantilevered NSOM fiber tip (apertured NOSM mode). The minimized heat- and shock-affected areas introduced during ultrafast laser based machining process, allows processing of even high conductivity thin metal films with minimized formation of any interfacial compounds between the metal films and the underlying substrate. Potential applications of this method may be in the fields of nanolithography, nanofluidics, nanoscale chemical and gas sensors, high-density data storage, nano-opto-electronics, as well as biotechnology related applications

Lithography-free centimeter-long nanochannel fabrication method using an electrospun nanofiber array

International Nuclear Information System (INIS)

Park, Suk Hee; Shin, Hyun-Jun; Lee, Sangyoup; Kim, Yong-Hwan; Yang, Dong-Yol; Lee, Jong-Chul

2012-01-01

Novel cost-effective methods for polymeric and metallic nanochannel fabrication have been demonstrated using an electrospun nanofiber array. Like other electrospun nanofiber-based nanofabrication methods, our system also showed high throughput as well as cost-effective performances. Unlike other systems, however, our fabrication scheme provides a pseudo-parallel nanofiber array a few centimeters long at a speed of several tens of fibers per second based on our unique inclined-gap fiber collecting system. Pseudo-parallel nanofiber arrays were used either directly for the PDMS molding process or for the metal lift-off process followed by the SiO 2 deposition process to produce the nanochannel array. While the PDMS molding process was a simple fabrication based on one-step casting, the metal lift-off process followed by SiO 2 deposition allowed finetuning on height and width of nanogrooves down to subhundred nanometers from a few micrometers. Nanogrooves were covered either with cover glass or with PDMS slab and nanochannel connectivity was investigated with a fluorescent dye. Also, nanochannel arrays were used to investigate mobility and conformations of λ-DNA. (paper)

Topographically Engineered Large Scale Nanostructures for Plasmonic Biosensing

Science.gov (United States)

Xiao, Bo; Pradhan, Sangram K.; Santiago, Kevin C.; Rutherford, Gugu N.; Pradhan, Aswini K.

2016-04-01

We demonstrate that a nanostructured metal thin film can achieve enhanced transmission efficiency and sharp resonances and use a large-scale and high-throughput nanofabrication technique for the plasmonic structures. The fabrication technique combines the features of nanoimprint and soft lithography to topographically construct metal thin films with nanoscale patterns. Metal nanogratings developed using this method show significantly enhanced optical transmission (up to a one-order-of-magnitude enhancement) and sharp resonances with full width at half maximum (FWHM) of ~15nm in the zero-order transmission using an incoherent white light source. These nanostructures are sensitive to the surrounding environment, and the resonance can shift as the refractive index changes. We derive an analytical method using a spatial Fourier transformation to understand the enhancement phenomenon and the sensing mechanism. The use of real-time monitoring of protein-protein interactions in microfluidic cells integrated with these nanostructures is demonstrated to be effective for biosensing. The perpendicular transmission configuration and large-scale structures provide a feasible platform without sophisticated optical instrumentation to realize label-free surface plasmon resonance (SPR) sensing.

High-Pressure Thermodynamic Properties of f-electron Metals, Transition Metal Oxides, and Half-Metallic Magnets

International Nuclear Information System (INIS)

Richard T. Scalettar; Warren E. Pickett

2005-01-01

This project involves research into the thermodynamic properties of f-electron metals, transition metal oxides, and half-metallic magnets at high pressure. These materials are ones in which the changing importance of electron-electron interactions as the distance between atoms is varied can tune the system through phase transitions from localized to delocalized electrons, from screened to unscreened magnetic moments, and from normal metal to one in which only a single spin specie can conduct. Three main thrusts are being pursued: (1) Mott transitions in transition metal oxides, (2) magnetism in half-metallic compounds, and (3) large volume-collapse transitions in f-band metals

High-Pressure Thermodynamic Properties of f-electron Metals, Transition Metal Oxides, and Half-Metallic Magnets

Energy Technology Data Exchange (ETDEWEB)

Scalettar, Richard T.; Pickett, Warren E.

2004-07-01

This project involves research into the thermodynamic properties of f-electron metals, transition metal oxides, and half-metallic magnets at high pressure. These materials are ones in which the changing importance of electron-electron interactions as the distance between atoms is varied can tune the system through phase transitions from localized to delocalized electrons, from screened to unscreened magnetic moments, and from normal metal to one in which only a single spin specie can conduct. Three main thrusts are being pursued: (1) Mott transitions in transition metal oxides, (2) magnetism in half-metallic compounds, and (3) large volume-collapse transitions in f-band metals.

High-Pressure Thermodynamic Properties of f-electron Metals, Transition Metal Oxides, and Half-Metallic Magnets

Energy Technology Data Exchange (ETDEWEB)

Richard T. Scalettar; Warren E. Pickett

2005-08-02

This project involves research into the thermodynamic properties of f-electron metals, transition metal oxides, and half-metallic magnets at high pressure. These materials are ones in which the changing importance of electron-electron interactions as the distance between atoms is varied can tune the system through phase transitions from localized to delocalized electrons, from screened to unscreened magnetic moments, and from normal metal to one in which only a single spin specie can conduct. Three main thrusts are being pursued: (i) Mott transitions in transition metal oxides, (ii) magnetism in half-metallic compounds, and (iii) large volume-collapse transitions in f-band metals.

When lithography meets self-assembly: a review of recent advances in the directed assembly of complex metal nanostructures on planar and textured surfaces

Science.gov (United States)

Hughes, Robert A.; Menumerov, Eredzhep; Neretina, Svetlana

2017-07-01

One of the foremost challenges in nanofabrication is the establishment of a processing science that integrates wafer-based materials, techniques, and devices with the extraordinary physicochemical properties accessible when materials are reduced to nanoscale dimensions. Such a merger would allow for exacting controls on nanostructure positioning, promote cooperative phenomenon between adjacent nanostructures and/or substrate materials, and allow for electrical contact to individual or groups of nanostructures. With neither self-assembly nor top-down lithographic processes being able to adequately meet this challenge, advancements have often relied on a hybrid strategy that utilizes lithographically-defined features to direct the assembly of nanostructures into organized patterns. While these so-called directed assembly techniques have proven viable, much of this effort has focused on the assembly of periodic arrays of spherical or near-spherical nanostructures comprised of a single element. Work directed toward the fabrication of more complex nanostructures, while still at a nascent stage, has nevertheless demonstrated the possibility of forming arrays of nanocubes, nanorods, nanoprisms, nanoshells, nanocages, nanoframes, core-shell structures, Janus structures, and various alloys on the substrate surface. In this topical review, we describe the progress made in the directed assembly of periodic arrays of these complex metal nanostructures on planar and textured substrates. The review is divided into three broad strategies reliant on: (i) the deterministic positioning of colloidal structures, (ii) the reorganization of deposited metal films at elevated temperatures, and (iii) liquid-phase chemistry practiced directly on the substrate surface. These strategies collectively utilize a broad range of techniques including capillary assembly, microcontact printing, chemical surface modulation, templated dewetting, nanoimprint lithography, and dip-pen nanolithography and

Does ascorbic acid supplementation affect iron bioavailability in rats fed micronized dispersible ferric pyrophosphate fortified fruit juice?

Science.gov (United States)

Haro-Vicente, Juan Francisco; Pérez-Conesa, Darío; Rincón, Francisco; Ros, Gaspar; Martínez-Graciá, Carmen; Vidal, Maria Luisa

2008-12-01

Food iron (Fe) fortification is an adequate approach for preventing Fe-deficiency anemia. Poorly water-soluble Fe compounds have good sensory attributes but low bioavailability. The reduction of the particle size of Fe fortificants and the addition of ascorbic acid might increase the bioavailability of low-soluble compounds. The present work aims to compare the Fe absorption and bioavailability of micronized dispersible ferric pyrophosphate (MDFP) (poorly soluble) to ferrous sufate (FS) (highly soluble) added to a fruit juice in presence or absence of ascorbic acid (AA) by using the hemoglobin repletion assay in rats. After a hemoglobin depletion period, four fruit juices comprised of (1) FS, (2) MDFP, (3) FS + AA, (4) MDFP + AA were produced and administered to a different group of rats (n = 18) over 21 days. During the repletion period, Fe balance, hemoglobin regeneration efficiency (HRE), relative bioavailability (RBV) and Fe tissue content were determined in the short, medium and long term. Fe absorption and bioavailability showed no significant differences between fortifying the fruit juice with FS or MDFP. The addition of AA to the juice enhanced Fe absorption during the long-term balance study within the same Fe source. HRE and Fe utilization increased after AA addition in both FS and MDFP groups in every period. Fe absorption and bioavailability from MDFP were comparable to FS added to a fruit juice in rats. Further, the addition of AA enhanced Fe absorption in the long term, as well as Fe bioavailability throughout the repletion period regardless of the Fe source employed.

Determination of the biodistribution and biokinetics of radiopharmaca like 166Ho-ferric-hydroxide or 153Sm-EDTMP used for therapeutic treatment by energy dispersive measurements

International Nuclear Information System (INIS)

Fischer, H.; Poljanc, K.; Aiginger, H.; Pruefert, U.; Granegger, S.; Ofluoglu, S.; Pirich, Ch.; Sinzinger, H.; Dudczak, R.; Steger, F.

2003-01-01

The activity distribution of beta-emitting radionuclides in the human body and the respective therapeutic dose distribution in the target and the unwanted leakage in the other organs was determined by measurement of corresponding gamma-lines. The measurement was done by scanning in a whole-body counter in the General Hospital Vienna. It is possible to localize activity and dose distribution by means of the detected activity profiles of the four detectors. Two typical treatments are reported: the treatment of synovitis using radiation of 166 Ho-Ferric-Hydroxide (characteristic gamma-line: 81 keV) and radionuclide therapy focused at the palliative treatment of bone metastases with 153 Sm-EDTMP, a bone seeking beta-emitting radionuclide (characteristic gamma-line: 103 keV). For the determination of the applied dose, the leakage and the quality assurance spectroscopic data of a clinical whole-body counter can be a useful tool for controlling and monitoring in health care. (authors)

Transport properties of metal-metal and metal-insulator heterostructures

Energy Technology Data Exchange (ETDEWEB)

Fadlallah Elabd, Mohamed Mostafa

2010-06-09

In this study we present results of electronic structure and transport calculations for metallic and metal-insulator interfaces, based on density functional theory and the non-equilibrium Green's function method. Starting from the electronic structure of bulk Al, Cu, Ag, and Au interfaces, we study the effects of different kinds of interface roughness on the transmission coefficient (T(E)) and the I-V characteristic. In particular, we compare prototypical interface distortions, including vacancies, metallic impurities, non-metallic impurities, interlayer, and interface alloy. We find that vacancy sites have a huge effect on transmission coefficient. The transmission coefficient of non-metallic impurity systems has the same behaviour as the transmission coefficient of vacancy system, since these systems do not contribute to the electronic states at the Fermi energy. We have also studied the transport properties of Au-MgO-Au tunnel junctions. In particular, we have investigated the influence of the thickness of the MgO interlayer, the interface termination, the interface spacing, and O vacancies. Additional interface states appear in the O-terminated configuration due to the formation of Au-O bonds. An increasing interface spacing suppresses the Au-O bonding. Enhancement of T(E) depends on the position and density of the vacancies (the number of vacancies per unit cell). (orig.)

Influence of metallurgical and electrochemical factors on cracking of steels at nuclear power plants under high temperature

International Nuclear Information System (INIS)

Pokhmurskii, V.I.; Gnyp, I.P.

1994-01-01

The influence of metallurgical heterogeneities in steels and electrochemical factors on corrosion cracking under high temperature water environment is studied, with special emphasis on the influence of manganese sulfide inclusions and other non-metallic ones on the crack growth rate. Results show that the electro-chemical conditions for an hydrogen concentration increase in a pre-failure zone exist at a crack tip under cyclic loading; hydrogen penetrating into metals at high temperature reduces manganese sulfides, ferric carbides, and cause high pressure of gases in micro-discontinuities, thus leading to cyclic corrosion cracking; anodic (relatively to a metal matrix) inclusions are rather the cause of steel cracking resistance decrease than cathodic ones. 16 refs., 4 figs

Quantitative method of viral pollution determination for large volume of water using ferric hydroxide gel impregnated on the surface of glassfibre cartridge

Directory of Open Access Journals (Sweden)

Akira Homma

1974-01-01

Full Text Available Quantitative method of viral pollution determination for large volume of water using ferric hydroxide gel impregnated on the surface of glassfibre cartridge filter. The use of ferric hydroxide gel, impregnated on the surface of glassfibre cartridge filter enable us to recover 62.5% of virus (Poliomylitis type I, Lsc strain exsogeneously added to 400 liters of tap-water. The virus concentrator system consists of four cartridge filters, in which the three first one are clarifiers, where the contaminants are removed physically, without significant virus loss at this stage. The last cartridge filter is impregnated with ferric hydroxide gel, where the virus is adsorbed. After the required volume of water has been processed, the last filter is removed from the system and the viruses are recovered from the gel, using 1 liter of glycine/NaOH buffer, at pH 11. Immediately the eluate is clarified through series of cellulose acetate membranes mounted in a 142mm Millipore filter. For the second step of virus concentration, HC1 1N is added slowly to the eluate to achieve pH 3.5-4. MgC1, is added to give a final concentration of 0.05M and the viruses are readsorbed on a 0.45 , porosity (HA cellulose acetate membrane, mounted in a 90 mm Millipore filter. The viruses are recovered using the same eluent plus 10% of fetal calf serum, to a final volume of 3 ml. In this way, it was possible to concentrate virus from 400 liters of tap-water, into 1 liter in the first stage of virus concentration and just to 3 ml of final volume in a second step. The efficiency, simplicity and low operational cost, provded by the method, make it feasible to study viral pollution of recreational and tap-water sources.Relata-se o emprego de um concentrador portátil, o qual se mostrou capaz de recuperar 62,5% dos vírus (Polio I, amostra Lsc experimentalmente dispersos em 400 litros de água, os quais foram reduzidos a 3 ml. O sistema concentrador de vírus é composto de quatro

Alkali metals and group IIA metals

International Nuclear Information System (INIS)

Fenton, D.E.

1987-01-01

This chapter on the coordination complexes of the alkali metals of group IIA starts with a historical perspective of their chemistry, from simple monodentate ligands, metal-β-diketonates to the macrocyclic polyethers which act as ligands to the alkali and akaline earth metals. Other macrocyclic ligands include quarterenes, calixarenes, porphyrins, phthalocyanines and chlorophylls. A section on the naturally occurring ionophores and carboxylic ionophores is included. (UK)

Submicron three-dimensional structures fabricated by reverse contact UV nanoimprint lithography

DEFF Research Database (Denmark)

Kehagias, N.; Reboud, Vincent; Chansin, G.

2006-01-01

The fabrication of a three-dimensional multilayered nanostructure is demonstrated with a newly developed nanofabrication technique, namely, reverse contact ultraviolet nanoimprint lithography. This technique is a combination of reverse nanoimprint lithography and contact ultraviolet lithography....... In this process, a UV cross-linkable polymer and a thermoplastic polymer are spin coated onto a patterned hybrid metal-quartz stamp. These thin polymer films are then transferred from the stamp to the substrate by contact at a suitable temperature and pressure. The whole assembly is then exposed to UV light....... After separation of the stamp and the substrate, the unexposed polymer areas are rinsed away with acetone leaving behind the negative features of the original stamp with no residual layer....

Large-area nanoimprinting on various substrates by reconfigurable maskless laser direct writing

KAUST Repository

Lee, Daeho

2012-08-10

Laser-assisted, one-step direct nanoimprinting of metal and semiconductor nanoparticles (NPs) was investigated to fabricate submicron structures including mesh, line, nanopillar and nanowire arrays. Master molds were fabricated with high-speed (200mms 1) laser direct writing (LDW) of negative or positive photoresists on Si wafers. The fabrication was completely free of lift-off or reactive ion etching processes. Polydimethylsiloxane (PDMS) stamps fabricated from master molds replicated nanoscale structures (down to 200nm) with no or negligible residual layers on various substrates. The low temperature and pressure used for nanoimprinting enabled direct nanofabrication on flexible substrates. With the aid of high-speed LDW, wafer scale 4inch direct nanoimprinting was demonstrated. © 2012 IOP Publishing Ltd.

Sub-10 nm colloidal lithography for circuit-integrated spin-photo-electronic devices

Directory of Open Access Journals (Sweden)

Adrian Iovan

2012-12-01

Full Text Available Patterning of materials at sub-10 nm dimensions is at the forefront of nanotechnology and employs techniques of various complexity, efficiency, areal scale, and cost. Colloid-based patterning is known to be capable of producing individual sub-10 nm objects. However, ordered, large-area nano-arrays, fully integrated into photonic or electronic devices have remained a challenging task. In this work, we extend the practice of colloidal lithography to producing large-area sub-10 nm point-contact arrays and demonstrate their circuit integration into spin-photo-electronic devices. The reported nanofabrication method should have broad application areas in nanotechnology as it allows ballistic-injection devices, even for metallic materials with relatively short characteristic relaxation lengths.

Plasmonic colour generation

DEFF Research Database (Denmark)

Kristensen, Anders; Yang, Joel K. W.; Bozhevolnyi, Sergey I.

2016-01-01

Plasmonic colours are structural colours that emerge from resonant interactions between light and metallic nanostructures. The engineering of plasmonic colours is a promising, rapidly emerging research field that could have a large technological impact. We highlight basic properties of plasmonic...... colours and recent nanofabrication developments, comparing technology-performance indicators for traditional and nanophotonic colour technologies. The structures of interest include diffraction gratings, nanoaperture arrays, thin films, and multilayers and structures that support Mie resonances...... and whispering-gallery modes. We discuss plasmonic colour nanotechnology based on localized surface plasmon resonances, such as gap plasmons and hybridized disk–hole plasmons, which allow for colour printing with sub-diffraction resolution. We also address a range of fabrication approaches that enable large...

Performance of metallic fuels in liquid-metal fast reactors

International Nuclear Information System (INIS)

Seidel, B.R.; Walters, L.C.; Kittel, J.H.

1984-01-01

Interest in metallic fuels for liquid-metal fast reactors has come full circle. Metallic fuels are once again a viable alternative for fast reactors because reactor outlet temperature of interest to industry are well within the range where metallic fuels have demonstrated high burnup and reliable performance. In addition, metallic fuel is very tolerant of off-normal events of its high thermal conductivity and fuel behavior. Futhermore, metallic fuels lend themselves to compact and simplified reprocessing and refabrication technologies, a key feature in a new concept for deployment of fast reactors called the Integral Fast Reactor (IFR). The IFR concept is a metallic-fueled pool reactor(s) coupled to an integral-remote reprocessing and fabrication facility. The purpose of this paper is to review recent metallic fuel performance, much of which was tested and proven during the twenty years of EBR-II operation

Removal of the blue 1 dye of aqueous solutions using ferric zeolite; Remocion del colorante azul 1 de soluciones acuosas utilizando zeolita ferrica

Energy Technology Data Exchange (ETDEWEB)

Pinedo H, S. Y.

2010-07-01

Water is essential to all life forms, including humans. In recent years water use has increased substantially, also has been altered in its capacity as a result of various human activities, such as domestic, industrial and agricultural, also by natural activity. Undoubtedly one of the main pollutants today are the waste generated by the food industry, due to the use of dyes for the production of their products. So it is necessary to restore water quality through treatment systems to remove contaminants, and thus prevent disease and imbalance of ecosystems. Due to the above, it is important to conduct research directed towards finding new ways to remove dyes such as blue 1 used in the food industry, using low cost materials and abundant in nature as zeolites. To accomplish the above, the present study has the purpose to evaluate the adsorption capacity of the blue dye 1 in aqueous solutions. To accomplish that objective, the zeolite material was reconditioned to improve its sorption properties of the material and provide the ability to adsorb pollutants such as this dye. The zeolite material was characterized by scanning electron microscopy and elemental analysis, X-ray diffraction and infrared spectroscopy. To evaluate the ability of blue 1 dye sorption the kinetics and sorption isotherms were determined; the experimental results were adjusted to mathematical models such as pseudo-first order, pseudo second order and Elovich to describe the kinetic process, and the Langmuir, Freundlich and Langmuir-Freundlich to describe sorption isotherms. The results showed that ferric zeolite surface is a heterogeneous material and has a considerable adsorption capacity, which makes it a potential adsorbent for removing color from aqueous streams. Also the sorption of the dye was evaluated at different ph values; the most sorption was carried out at ph values 1, 3 and 11. We also evaluated the change in mass where the sorption capacities for the blue 1 increase by increasing

Synthesis of LiFePO4/C cathode material from ferric oxide and organic lithium salts

International Nuclear Information System (INIS)

Shi Zhongqi; Huang Ming; Huai Yongjian; Lin Ziji; Yang Kerun; Hu Xuebu; Deng Zhenghua

2011-01-01

Research highlights: → LiFePO 4 can be synthesized from Fe 2 O 3 by a sequence of free-radical reactions. → Organic lithium salts can avoid the composition segregation of the precursor. → Low cost ferric oxide and environmentally friendly distilled water are used. - Abstract: LiFePO 4 /C cathode material has been simply synthesized via a modified in situ solid-state reaction route using the raw materials of Fe 2 O 3 , NH 4 H 2 PO 4 , Li 2 C 2 O 4 and lithium polyacrylate (PAALi). The sintering temperature of LiFePO 4 /C precursor is studied by thermo-gravimetric (TG)/differential thermal analysis (DTA). The physical properties of LiFePO 4 /C are then investigated through analysis using by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscope (TEM) and the electrochemical properties are investigated by electrochemical impedance spectra (EIS), cyclic voltammogram (CV) and constant current charge/discharge test. The LiFePO 4 /C composite with the particle size of ∼200 nm shows better discharge capacity (156.4 mAh g -1 ) than bare LiFePO 4 (52.3 mAh g -1 ) at 0.2 C due to the improved electronic conductivity which is demonstrated by EIS. The as-prepared LiFePO 4 /C through this method also shows excellent high-rate characteristic and cycle performance. The initial discharge capacity of the sample is 120.5 mAh g -1 and the capacity retention rate is 100.6% after 50 cycles at 5 C rate. The results prove that the using of organic lithium salts can obtain a high performance LiFePO 4 /C composite.

Understanding of the mode of action of Fe(III)-EDDHA as iron chlorosis corrector based on its photochemical and redox behavior.

Science.gov (United States)

Gómez-Gallego, Mar; Pellico, Daniel; Ramírez-López, Pedro; Mancheño, María J; Romano, Santiago; de la Torre, María C; Sierra, Miguel A

2005-10-07

The very low reduction potential of the chelate Fe(III)-EDDHA (EDDHA = ethylenediamine N,N'-bis(2-hydroxy)phenylacetic acid) makes it unreactive in photochemically or chemically induced electron transfer processes. The lack of reactivity of this complex toward light invalidates photodegradation as an alternative mechanism for environmental elimination. However, in spite of its low reduction potential, the biological reduction of Fe(III)-EDDHA is very effective. Based on electrochemical measurements, it is proposed that Fe(III)-EDDHA itself is not the substrate of the enzyme ferric chelate reductase. Likely, at the more acidic pH in the vicinity of the roots, the ferric chelate in a closed form (FeL-) could generate a vacant coordination site that leads to an open hexacoordinate species (FeHL) where the reduction of the metal by the enzyme takes place.

Study of Dronino Iron Meteorite Weathering in Clay Sand Using Mössbauer Spectroscopy

Directory of Open Access Journals (Sweden)

Grigoriy A. Yakovlev

2016-06-01

Full Text Available Weathering products of two fragments of Dronino iron ungrouped meteorite found in the wet and drier clay sand were studied using X-ray diffraction and Mössbauer spectroscopy with a high velocity resolution. The products of metal oxidation in the internal and external surface layers were different for both fragments. The weathering products in fragment found in the wet clay sand contain magnetite (Fe3O4, maghemite (γ-Fe2O3, goethite (α-FeOOH and probably ferrihydrite (5Fe2O3∙9H2O while those in fragment found in drier clay sand contained ferric hydrous oxides (FeOOH and siderite (FeCO3 mainly. Concretions found near the first fragment contain ferric hydrous oxides (FeOOH mainly. This work is licensed under a Creative Commons Attribution 4.0 International License.

Studies of Metal-Metal Bonded Compounds in Catalysis

Energy Technology Data Exchange (ETDEWEB)

Berry, John F. [Univ. of Wisconsin, Madison, WI (United States)

2018-01-19

The overall goals of this research are (1) to define the fundamental coordination chemistry underlying successful catalytic transformations promoted by metal-metal bonded compounds, and (2) to explore new chemical transformations that occur at metal-metal bonded sites that could lead to the discovery of new catalytic processes. Transformations of interest include metal-promoted reactions of carbene, nitrene, or nitrido species to yield products with new C–C and C–N bonds, respectively. The most promising suite of transition metal catalysts for these transformations is the set of metal-metal bonded coordination compounds of Ru and Rh of the general formula M₂(ligand)₄, where M = Ru or Rh and ligand = a monoanionic, bridging ligand such as acetate. Development of new catalysts and improvement of catalytic conditions have been stymied by a general lack of knowledge about the nature of highly reactive intermediates in these reactions, the knowledge that is to be supplied by this work. Our three specific objectives for this year have been (A) to trap, isolate, and characterize new reactive intermediates of general relevance to catalysis, (B) to explore the electronic structure and reactivity of these unusual species, and how these two properties are interrelated, and (C) to use our obtained mechanistic knowledge to design new catalysts with a focus on Earth-abundant first-row transition metal compounds.

New metals

International Nuclear Information System (INIS)

Bergqvist, U.

1983-12-01

The aim of this report is to estimate the exposure to various metals and metal compounds and discuss the available information of the possible toxic effects of these metals and compounds. In the first section, some metals are defined as those with either a large or a fast increasing exposure to living organisms. The available information on toxicity is discussed in the second section. In the third section interesting metals are defined as compounds having a large exposure and an apparent insufficient knowledge of their possible toxic effects. Comments on each of these metals are also to be found in the third section. (G.B.)

Breast milk metal ion levels in a young and active patient with a metal-on-metal hip prosthesis.

Science.gov (United States)

Nelis, Raymond; de Waal Malefijt, Jan; Gosens, Taco

2013-01-01

Metal-on-metal resurfacing arthroplasty of the hip has been used increasingly over the last 10 years in younger active patients. The dissolution of the metal wear particles results in measurable increases in cobalt and chromium ions in the serum and urine of patients with a metal-on-metal bearing. We measured the cobalt, chromium, and molybdenum ion levels in urine; serum; and breast milk in a young and active patient with a metal-on-metal hip prosthesis after a pathologic fracture of the femoral neck. Metal-on-metal hip prosthesis leads to increasing levels of molybdenum in breast milk in the short-term follow-up. There are no increasing levels of chromium and cobalt ions in breast milk. Besides the already known elevated concentrations in serum of chromium and cobalt after implantation of a metal-on-metal hip prosthesis, we found no increasing levels of chromium and cobalt in urine. Copyright © 2013 Elsevier Inc. All rights reserved.

Myo-inositol-14C, phytic acid-14C and ferric phytate-14C metabolism through microbian action in an andosol soil

International Nuclear Information System (INIS)

Gonzalez I, J.

1977-01-01

The myo-inositol- 14 C, phytic acid- 14 C and ferric phytate- 14 C compounds were incubated in an andosol soil at 70% of the field capacity and at 36.5 deg C during twelve days. These compounds suffered a microbian oxidation at 14 CO 2 of 61.0, 1.9 and 0% respectively. The fixation of the phytic acid- 14 C was observed through the fast decrease in the metabolism, due to the formation of complexes with the Fe and Al (phytates). The myo-inositol- 14 C metabolism was reduced by a factor of nine at the second incubation day. The following mechanisms were observed in the myo-inositol metabolism: (i) adsorption of the inositol by the soil minerals, (ii) adsorption by humic acids, (iii) myo-inositol phosphorylation and (iv) epimerization of myo-inositol to chiro-inositol. It was found that the (i) and (ii) formation depends on the soil microbian activity. The (i), (ii) and (iii) interactions were considered as possible mechanisms for the inhibition of the myo-inositol microbian oxidation. The inhibition of the myo-inositol oxidation through adsorption or phosphorylation is considered as a chemical blockade for the hydroaxial group, avoiding this way a microbian oxidation stereospecific of this hydroxil group. (author)

Radical-Scavenging Activity and Ferric Reducing Ability of Juniperus thurifera (L., J. oxycedrus (L., J. phoenicea (L. and Tetraclinis articulata (L.

Directory of Open Access Journals (Sweden)

Meryem El Jemli

2016-01-01

Full Text Available Objective. The aim of this work is to study and compare the antioxidant properties and phenolic contents of aqueous leaf extracts of Juniperus thurifera, Juniperus oxycedrus, Juniperus Phoenicea, and Tetraclinis articulata from Morocco. Methods. Antioxidant activities of the extracts were evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH free radical-scavenging ability, Trolox equivalent antioxidant capacity (TEAC, and ferric reducing antioxidant power (FRAP assays. Also the total phenolic and flavonoids contents of the extracts were determined spectrophotometrically. Results. All the extracts showed interesting antioxidant activities compared to the standard antioxidants (butylated hydroxytoluene (BHT, quercetin, and Trolox. The aqueous extract of Juniperus oxycedrus showed the highest antioxidant activity as measured by DPPH, TEAC, and FRAP assays with IC50 values of 17.91±0.37 μg/mL, 19.80±0.55 μg/mL, and 24.23±0.07 μg/mL, respectively. The strong correlation observed between antioxidant capacities and their total phenolic contents indicated that phenolic compounds were a major contributor to antioxidant properties of these plants extracts. Conclusion. These results suggest that the aqueous extracts of Juniperus thurifera, Juniperus oxycedrus, Juniperus phoenicea, and Tetraclinis articulata can constitute a promising new source of natural compounds with antioxidants ability.