Fe Granules Research Articles

Development of Shaped MIL-100(Fe) Granules for High-Performing Adsorption Desalination: From Formulation Optimization to System Test

Development of Shaped MIL-100(Fe) Granules for High-Performing Adsorption Desalination: From Formulation Optimization to System Test

Use of granules and free salts for Fe and Zn fortification of leafy vegetables: Improvements in trace element bioaccessibility and fulfillment of Dietary Reference Intakes

BackgroundLeafy vegetables represent an excellent dietary source of trace elements such as Fe and Zn. Nevertheless, Fe and Zn bioaccessibility can lessen due to a high concentration of anti-nutritional compounds. The encapsulation of Fe and Zn salts as granules could be used to fortify these leafy vegetables. MethodThree leafy vegetables, spinach, Swiss chard and Ethiopian mustard were fortified with iron sulfate and zinc sulfate as granules and free salts in order to test the improvements in the bioaccessibility and fulfillments of DRIs. Fe and Zn granules were prepared in a fluidized bed granulator. A probabilistic analysis was performed, using experimental data, to assess bioaccessible intake and fulfillments of DRIs in European populations. ResultsFe contents ranged between 4.8 mg/100 g of Ethiopian mustard to 157.4 mg/100 g of spinach. Fe and Zn bioaccessibility percentages were low for Swiss chard and spinach without fortification. Fortification with granules improved Fe bioaccessibility of these latter vegetables (196 and 223 mg/100 g). Zn contents in samples without fortification ranged between 2.3 mg/100 g for Ethiopian mustard and 7.4 mg/100 g for spinach. Zn fortification as granules improved Zn bioaccessibility for the three vegetables studied. Thus, Zn bioccessible concentrations ranged between 17.4 and 108 mg/100 g for the solubility assay and between 5.9 and 31.1 mg/100 g for the dialyzability assay. Besides, the probability analysis showed that fortification had a better performance in meeting DRIs for those populations with higher consumption levels of leafy vegetables. ConclusionsThe probability analysis demonstrated that fortification can be a suitable strategy to meet DRIs for both trace elements, which was especially remarkable for Fe. Fortification with granule was more effective in most the cases, although for Ethiopian mustard, free salt of Fe showed a better performance.

Upgraded lithium storage performance of defect-rich Si@C anode assisted by Fe2O3-induced pseudocapacitance

Following a flowsheet comprised of a hydrothermal reaction and a dehydration/carbonization, Si-xFe/O@C anodes featured with Fe-doping and carbon encapsulation were assembled. Comparing with pure Si, Si disseminated with in situ generated nano-scaled ferric oxide (Fe2O3) particulates displays remarkably improved cyclic performance. Fe2O3 may induce amorphization and optimize electrical conductivity, by enhancing the formation of Fe and Li2O amidst charging-discharging cycles. The as-derived Fe phase benefits the transport and storage of lithium-ion and electrons. Meanwhile, numerous tiny interfaces can be constructed between Fe granules and adjacent LixSi or Li2O, and generate pseudocapacitance. After the carbonization of resorcinol-formaldehyde resin encapsulated on Si granules, core-shell structured Si-xFe/O@C particulates can be assembled. Owing to the synergism of defect-rich structure, carbon layer well-wrapped thereon and interfacial pseudocapacitance, these nanocomposite anode materials exhibit long cyclic and upgraded rate performance. After 200 cycles, Si-0.42Fe/O@C anode retains a capacity of 929 mAh·g−1 at 1 A·g−1 and 735 mAh·g−1 at 2 A·g−1. In the rate performance test operated at 5 A·g−1, a high current density, 844 mAh·g−1 could be released. Si-0.42Fe/O@C can be charged with a specific capacity exceeding 250 mAh·g−1 over the potential range of 0.75-3 V at various current densities, demonstrating the contribution of nano-Fe pseudocapacitance effect to the energy storage of Si anodes.

Tunneling magnetoresistance in ensembles of ferromagnetic granules with exchange interaction and random easy axes of magnetic anisotropy

We study the tunneling magnetoresistance in the ensembles of ferromagnetic granules with random easy axes of magnetic anisotropy taking into account the exchange interaction between granules. It is shown that due to the exchange interaction magnetoresistance is effectively decoupled from magnetization, i.e. the strongest negative magnetoresistance can be observed at the field where magnetization is almost saturated. Under some conditions, the sign of magnetoresistance can be reversed and tunneling magnetoresistance can become positive at certain magnetic fields. Our theory agrees with measurements of magnetoresistance in ensembles of Fe granules in SiC x N y matrix.

The open-pin failure of power device under the combined effect of thermo-migration and electro-migration

With the miniaturization of electronic products, power devices sustain more and more operations under high power, high frequency, and high integration. Power electronic devices are subjected to high operating temperature and current density, which poses a serious challenge on the packaging materials. An open-pin failure was found on a metal-oxide-semiconductor field-effect transistor (MOSFE) device after operated for 3−4 a under high current density condition. The lead frame material is C194 alloy, belonging to Cu-Fe-P alloy, which is a copper base alloy strengthened by dispersion. The operating temperature of the MOSFET device is in the range of 88 − 120°C at the full working current of about 15 A from the drain to the source, while the gate current is relatively small in a milliampere level. Failure analysis is conducted on the open-pin MOSFET device. According to the investigations by scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS), two intermetallic compounds (IMCs), Cu3Sn and Cu6Sn5, were formed at both the C194 alloy/Sn-Pb and the Cu/Sn-Pb solder interfaces. However, the crack is always initiated at the C194 alloy/Sn-Pb solder interface, no matter for the source or the drain. Usually, the crack would initiate at the cathode side due to the sole effect of electro-migration. In this work, the crack initiated at the cathode side for the drain, but at the anode side for the source. According to the working condition of the MOSFET device, this failure crack can be attributed to the combined effects of electro-migration and thermo-migration on multi-element interfacial diffusion and vacancy migration. In detail, for the source of MOSFET device, the direction of Cu thermo-migration flux is opposite to the electro-migration flux, while the thermo-migration flux is large so that it can compensate the effect of electro-migration flux, thus leading to the crack at the anode. For the drain of device, the direction of Cu thermo-migration flux is the same as that of electro-migration, which leads to a severe cracking at the cathode. Moreover, in order to reveal the cracking process, SEM analysis was conducted on the fracture surface where plenty of fine Fe-rich granules and some Cu-Sn IMCs were observed. Furthermore, the electron probe micro analysis (EPMA) demonstrated that these fine Fe-rich granules form a continuous layer adjacent to the crack. Transmission electron microscopy (TEM) and selected area electron diffraction (SAED) were also conducted in order to characterize the interfacial microstructure with Fe-rich granules/layer. At the C194/IMC interface, the Fe granules with body-centered cubic (bcc) structure accumulated as a continuous layer with an obvious grain growth compared to the uniformly dispersing Fe granules within the C194 alloy matrix. The existence of segregated Fe layer and Kirkendall voids would weaken the original bonding between C194 and IMC, so the crack always initiated along the Fe layer or Kirkendall voids when the thermal stress or mechanical stress applied. Above all, this coupled open-pin failure mode and its mechanism would provide a theoretical guidance for the optimization of product process and the improvement of service life.

Fast, Cost-effective and Energy Efficient Mercury Removal-Recycling Technology

We herein present a novel and sustainable technology for mercury recycling, with the maximum observed uptake capacity. Facile synthesis of the most efficient (~1.9 gg−1) nano-trap, made of montmorillonite-Fe-iron oxides, was performed to instantaneously remove mercury(II) ions from water. Elemental Hg was recovered from the adduct, by employing Fe granules, at ambient conditions. Varied pHs and elevated temperatures further enhanced this already highly efficient recycling process. The reduction of Hg(II) to Hg(I) by the nano trap and Hg(I) to Hg(0) by Fe granules are the main driving forces behind the recycling process. Facile sustainable recycling of the nano-trap and Fe granules require no additional energy. We have further developed a recyclable model for Hg nano-trap, which is inexpensive (<$5 CAD), and can remove mercury in a few seconds. This technology has multiple applications, including in the communities exposed to mercury contamination.

Iron‐Dicyano Dichloro Quinone Primary Battery

AbstractA Iron/2,3‐dichloro‐5,6‐dicyano‐1,4‐benzoquinone (Fe‐DDQ) primary battery operating in neat methanesulfonic acid (MSA) is explored. As it involves abundant Fe and renewable materials such as DDQ and MSA, it is expected to be cost effective powering system for single use applications. Stainless steel (SS‐304) is used as Fe source (anode) and DDQ in MSA used as cathode. Oxidation characteristics of SS‐304 in neat MSA, 14 M and 12 M MSA were explored. As reactivity of SS with MSA is controllable without any rapid H2 evolution while comparing with that of Fe granules, making/demonstration of SS‐DDQ based battery system is possible. Moreover, neat MSA does not allow formation of passive layer on SS, thereby allowing continuous operation of battery. As a proof of concept, we have demonstrated a two‐cell stack powering a light emitting diode (LED).

Radiosynthesis of 11C-phenytoin Using a DEGDEE Solvent for Clinical PET Studies.

Objective(s):Phenytoin is an antiepileptic drug that is used worldwide. The whole-body pharmacokinetics of this drug have been extensively studied using 11C-phenytoin in small animals. However, because of the limited production amounts that are presently available, clinical 11C-phenytoin PET studies to examine the pharmacokinetics of phenytoin in humans have not yet been performed. We aimed to establish a new synthesis method to produce large amounts of 11C-phenytoin to conduct human studies. Methods: [11C] methane was produced using an in-house cyclotron by the 14N (p, α) 11C nuclear reaction of 5 % of hydrogen containing 95 % of nitrogen gas. About 30 GBq of 11C-methane was then transferred to a homogenization cell containing Fe2O3 powder mixed with Fe granules heated at 320 0C to yield 11C-phosgene. Xylene, 1,4-dioxane, and diethylene glycol diethyl ether (DEGDEE) were investigated as possible reaction solvents. Results:The ratio of 11C-phenytoin radioactivity to the total 11C radioactivity in the reaction vessel (reaction efficiency) was 7.5% for xylene, 11% for 1,4-dioxane, and 37% for DEGDEE. The synthesis time was within 45 min from the end of bombardment until obtaining the final product. The radioactivity produced was more than 4.1 GBq in 10 mL of saline at the end of synthesis. The specific activity of the product ranged from 1.7 to 2.2 GBq/μmol. The quality of the [11C] phenytoin injection passed all criteria required for clinical use. Conclusion:The use of DEGDEE as a solvent enabled the production of a large amount of 11C-phenytoin sufficient to enable PET studies examining the human pharmacokinetics of phenytoin.

Corrosion product and precipitate distribution in two-component Fe(0) permeable reactive barriers

In situ Fe(0) permeable reactive barriers are suitable for the passive treatment of various hazardous substances in groundwater. Unavoidable secondary minerals on cast iron granules (Fe(0)) in permeable reactive barriers cause passivation and reduction of pore volume. Precipitate agglomeration on mixing components might reduce the passivating layers on Fe(0). Mixtures of Fe(0) with different conventional, porous or reactive granular materials (sand, gravel, pumice, anthracite, wood, granular ferric hydroxide, calcite) were analyzed with different methods after 200days exposure to contaminated groundwater in column studies. Gravimetric analyses indicate that the weight increase of the Fe(0) granules was greater than that of all mixing materials except calcite indicating preferential formation of secondary minerals on Fe(0) granules. A greater weight increase compared to Fe(0) was only observed for calcite, which was transformed during the experiment into large and compact aragonite crystals on the granule surfaces. Microscopic analyses of cross-sections showed a corrosion build-up on Fe(0) but only minor precipitate layers on mixing materials. Akaganeite, a non-magnetic ferric hydroxide as major component of the granular ferric hydroxide, was transformed into magnetite during ground water treatment as revealed by X-ray diffraction. Hence iron hydroxides are intermediate phases that further transform to the final product magnetite.

Development and in vitro characterization of a novel prenatal multi‐micronutrient powder incorporating differentially microencapsulated calcium carbonate and ferrous fumarate to overcome intra‐intestinal calcium‐iron interactions

To overcome calcium(Ca)‐iron(Fe) interactions in a prenatal multi‐micronutrient supplement for low‐income settings, we developed a Ca‐Fe‐folic acid (FA) powder for home fortification incorporating enteric coatings sensitive to low pH (for gastric Fe release) and high pH (for mid‐duodenal Ca release). Ca carbonate and ferrous fumarate granules were generated by wet granulation. A fluid‐bed coating process was used to apply subcoat to the Ca granules to improve sphericity and to apply a pH‐sensitive enteric coat. Fe granules were encapsulated with a time‐dependent coating, including FA in the matrix. Fe and Ca dissolution profiles were assessed during sequential exposure to acidic (pH 1.2, 120 min) and basic (pH 5.8, 100 min) media using a modified USP methodology. At pH 1.2, Ca release was 15% after 120 min; Fe release was 90% and 100% at 20 and 35 min, respectively. After 100 min at pH 5.8, 85% of total Ca was released. These dissolution profiles indicated that the differential release of Ca and Fe was achieved within targeted acid‐base environments. Clinical testing to document fractional Ca absorption during pregnancy is underway. Research support was provided by the Saving Lives at Birth partners.Grant Funding Source: Saving Lives at Birth

Relation of Cytosolic Iron Excess to Cardiomyopathy of Friedreich's Ataxia

Cardiomyopathy is the leading cause of death in Friedreich's ataxia. This autosomal recessive disease is caused by a homozygous guanine-adenine-adenine trinucleotide repeat expansion in the frataxin gene (chromosome 9q21). One untoward effect of frataxin deficiency is the lack of iron (Fe)-sulfur clusters. Progressive remodeling of the heart in FA, however, may be more specifically related to sarcoplasmic Fe overload. The Fe-containing inclusions in a small percentage of cardiomyocytes may not represent purely mitochondrial accumulation of the metal. The objective of the present study was to re-examine the contribution of Fe to cardiomyocyte hypertrophy, fiber necrosis, and myocardial scarring, using a combination of X-ray fluorescence, slide histochemistry of Fe, and immunohistochemistry of 2 Fe-related proteins. Polyethylene glycol-embedded human cardiac tissues from the left and right ventricular walls, ventricular septum, right atrium, and atrial septum were studied using qualitative and quantitative X-ray fluorescence. Tissues were recovered from the polyethylene glycol matrix, re-embedded in paraffin, and sectioned for visualization of Fe, ferritin, and ferroportin. X-ray fluorescence showed quantifiable levels of Fe and zinc. Regions of significantly increased Fe (1 to 4 mm(2)) were irregularly distributed throughout the working myocardium. Fe granules were sparse in conductive tissue. Zinc signals remained unchanged. Robust cytosolic ferritin reaction product occurred in many fibers of the affected regions. Ferroportin displayed no response except in fibers with advanced Fe overload. These observations are at variance with the concept of selective Fe overload only in cardiac mitochondria. In conclusion, Fe-mediated damage to cardiomyocytes and myocardial scarring are more likely due to cytosolic Fe excess.

Morphology, magnetic and resonance properties of Fe/MgO multilayers

Magnetic, resonance and transport properties of Fe(t nm)/MgO(3.0 nm) multilayers prepared by pulsed laser deposition were investigated. Comparison of the data allows conclusions on Fe layers morphology. For t<0.61 nm typical features of granular cermet films in dielectric regime are observed, i.e. high electrical resistance, isotropic magnetoresistance and strong temperature dependence of magnetization. For higher t coalescence of Fe granules occurs and metallic percolation cluster is formed at t∼0.81 nm. This is manifested by rapid decrease of films resistance and formation of multipeak ferromagnetic resonance spectra. For t>1.25 nm a continuous coverage of MgO by Fe takes place. However, the morphology of Fe layers is rough. This causes the appearance of magnetostatic resonance modes analogous to those observed for continuous films deposited on embossed surfaces.

Structural and Magnetic Properties of Fe and Au Ion-Implanted Al2O3 Single Crystals

Au ion implantation in Fe ion-implanted Al2O3 (Fe/Al2O3) has been performed in order to tailor the structural, magnetic and optical properties of Fe granules in Al2O3 matrix. After Au ion implantation, Rutherford backscattering (RBS) measurements indicate the decrease and the redistribution of retained Fe atoms with the inclusion of Au atoms, and the patterns of X-ray diffraction (XRD) show the formation of Au granules in the Fe/Al2O3. Besides, the magnetization curves of the Fe/Al2O3 after Au ion implantation show still the superparamagnetic characteristics and the decrease of saturation magnetization, and the optical absorption measurements indicate the formation of Au granules in the Fe/Al2O3 in accordance with the XRD result. In addition, we investigated a behavior of Fe granules in Al2O3 matrix by conversion electron Mössbauer spectroscopy (CEMS), which indicates the decrease of superparamagnetic state as a function of Au ion dose. As a result, it is suggested that Au ion implantation has potentialities to tailor the physical properties of Fe granules in Al2O3 matrix.

Thickness dependence of magnetic properties in (Fe) 0.73(Sm 2O 3) 0.27 nano-granular films

(Fe) 0.73(Sm 2O 3) 0.27 nano-granular films with thicknesses varying from 46 nm to 220 nm were fabricated by a RF magnetron sputtering method. The static and dynamic magnetic properties of these films on thickness dependence have been investigated in detail. High-resolution transmission electron micrograph shows that the films consist of Fe granules and crystalline Sm 2O 3 matrix. The results reveal that there is a critical thickness t c around 65 nm in the (Fe) 0.73(Sm 2O 3) 0.27 nano-granular films. Below t c, the films possess an in-plane uniaxial anisotropy and lower H c. Above t c, the films exhibit a small perpendicular anisotropy, higher H c and stripe domains, and the stripe period increases with increasing film thickness. The dynamic permeability spectra measured over the frequency range of 0.1–7 GHz display one resonance peak for all thicknesses. The spectrum of the film with thickness below t c can be ascribed to the uniform coherent spin procession. Above t c, the increasing film thickness leads to an monotonously increase of the permeability (imaginary part), and a shift of resonance frequency towards the low frequency and a decrease of resonance linewidth for the films with thickness larger than 120 nm.

Giant Hall effect in (GaAs)Fe granular films

A series of (GaAs) 1 − x Fe x ( x: volume fraction) films with Fe granules embedded in GaAs matrix were prepared by magnetron sputtering. Hall Effect of the films was characterized. The largest saturated Hall resistivity of 17.3 μ Ω cm was observed in (GaAs) 30Fe 70 film at room temperature, which is over 2 orders larger than that of pure Fe, about 1 order larger than that of (NiFe)–(Al 2O 3) and (NiCo)–(SiO 2) granular films prepared under the same preparation conditions, and 150% larger than that of Ge 30Fe 70.

A Study on the Highly Efficient Synthesis and Pharmaceutical Evaluation of PET Radiopharmaceuticals for the Clinical Application

Positron Emission Tomography (PET) is an advanced non-invasive technology used in the field of nuclear medicine for clinical diagnosis using radiotracers labeled with short-lived positron emitting radionuclides such as (11)C (half-life: 20.4 min), (13)N, (15)O and (18)F. The present study describes an efficient rapid synthesis method for [(11)C]Phosgene ([(11)C]COCl(2)) which is an important potential precursor for preparation of PET radiopharmaceuticals. Catalytic oxidation of [(11)C]CCl(4) using Fe(2)O(3) powder mixed with Fe granules as an oxidizing agent was newly accomplished with a development of fully automated synthetic apparatus. Utilization of produced [(11)C]COCl(2) provided a substantial synthesis of [2-(11)C]thymine as a key intermediate for preparation of [2-(11)C]thymidine, a PET tracer to evaluate cellular proliferation. Direct ring closure reaction of the alkali metal salt of beta-(N-benzoyl-amino)methacrylamide with [(11)C]COCl(2) readily proceeded under mild conditions to afford [2-(11)C]thymine in fair yield reproducibly. By way of further application, a useful PET ligand for beta-adrenoreceptors, S-(-)-[(11)C]CGP-12177 (CGP) was synthesized in markedly high yield with high specific activity and radiochemical purity. CGP for intravenous injection was prepared in 25 min after EOB with a yield of 1.5+/-0.2 GBq. These results of quality control tests demonstrated that CGP preparation is suitable for routine clinical use. Thus, CGP-PET study has been newly added to clinical PET for cardiac functional investigation in Hokkaido University Hospital.

Antiferromagnetic-coupling-induced magnetoresistance enhancement in Fex(TiO2)1−x films

Fe-incorporated amorphous TiO2 films with different Fe volume fractions of 0.46⩽x⩽0.76 were deposited by cosputtering iron and Ti targets in an Ar+O2 mixture. X-ray diffraction and x-ray photoelectron spectroscopy analyses give a structure of nanosized Fe particles embedded in amorphous TiO2 matrix for the Fex(TiO2)1−x films. Magnetic measurements show antiferromagnetic coupling between nanoscaled Fe granules when x&amp;lt;0.60. The magnetoresistance of Fe0.46(TiO2)0.54 is about −7.6% at room temperature, which increases dramatically with decreasing temperature below ∼100K and reaches −29.3% at 3K. This significant enhancement of magnetoresistance can be qualitatively explained by antiferromagnetic coupling between Fe granules.

Characterisation by X-ray microanalysis of metal granules in the mucus trails of Littorina littorea (Gastropoda) along a putative pollution gradient

Metal-containing granules in the mucus trails of the marine gastropod Littorina littorea from nine sites in north-east England were analysed for elemental composition by X-ray microanalysis and characterised relative to a putative gradient of pollution. Overall granule density varied significantly between sites, means of 6.5-17.0 per field of view (2688 microm2). Most granules found (64%) were poly-metal of a wide variety of compositions, but could be classified as Si+X, Mg+X, S+X, Na+X, P+Ca, P+Al, where X indicates any other combination of elements. Si+Al+X accounted for 61% of the poly-metal granules found and was considered to be contamination from the beach substratum. In single-metal granule form only Ca, Si, Fe, Ti, Al and Na were found. The most common single-metal granule at each site was of Ca, except at two sites, where the most common single-metal granule was of Si. The densities of these granule types varied between sites but differences were found to be significant only in the case of Si granules. Across all sites, single-metal granules of Si (mean = 2.49 microm +/- 1.44 SD, n = 141) and Ca (2.22 microm +/- 1.08 SD, n = 147) were significantly larger than granules of Fe (1.74 microm +/- 0.95 SD, n = 63) and Ti (1.24 microm +/- 0.52 SD, n = 18). The range of sizes was large: Ca (0.5-6 microm), Si (0.5-10 microm), Fe (0.3-4.1 microm), Ti (0.5-2.5 microm). Between the sites there were significant differences in the size of Fe and Si granules but not Ca or Ti granules. Despite these variations in granule type and size, there was no evidence of a relationship with pollution and consequently a detoxifying function of the mucus trail in metal polluted environments is not apparent.

Evolution of magnetoresistance effect in iron–bismuth films

A unique time-dependent magnetotransport behavior has been observed in Fe–Bi films. Approximately one month was required to stabilize resistance after samples were fabricated. Initially, the as-prepared Fe–Bi films exhibit both ordinary magnetoresistance (MR) and anisotropic magnetoresistance. Fe precipitation changes the microstructure. Eventually, an isotropic and negative MR, like a giant MR effect was observed; it arises from electronic transport between Fe granules separated by Bi.

Facing-target sputtered Fe–C granular films: Structural and magnetic properties

Structural and magnetic properties of as-deposited and 550°C annealed Fe–C granular films have been investigated. It is found that the as-deposited samples are composed of amorphous Fe granules dispersed in an amorphous C matrix, and transformed to α(bcc)∕γ(fcc)-Fe and graphitelike C after being annealed at 550°C for one hour. The morphologies of the as-deposited samples are composition dependent, and the phase segregation between Fe and C phases can be seen by high-resolution transmission electron microscopy. Magnetic measurements reveal that the as-deposited samples are superparamagnetic at Fe composition of xv=49,58,65, and soft ferromagnetic at xv=77,84. The in-plane coercivity of the annealed specimens decreases with increasing xv, which is attributed to the enhanced intra-particle interaction, as evidenced by the long-range domain structures observed using magnetic force microscope images. The magnetic reversal mechanism deviates from ideal domain wall motion mode and approaches Stoner–Wohlfarth rotational mode with the decrease of Fe volume fraction.