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An investigation has been conducted into the effectiveness of two ‘production-line’ post-sinter surface treatments, namely steam treatment and oil impregnation, as methods of improving the corrosion-resistance of ferrous powder-metallurgy parts. Electrochemical techniques and simple immersion tests followed by transverse rupture strength determination were used to evaluate corrosion behaviour in aqueous chloride and dilute sulphuric acid solutions. ‘As-sintered’ and wrought and machined parts were tested for comparison purposes.In the chloride solution the corrosion-resistance of the treated parts was higher than that of either the as-sintered or machined parts, the steam treatment being particularly effective. In the acid solution, steam-treated parts showed the lowest corrosion-resistance of the four, with oil impregnation giving the highest resistance.

Sodium hypochlorite oxidation of cotton cellulose in the presence of traces of cobaltous hydroxide has been studied. The oxycellulose thus formed has been further chemically modified by subjecting it separately to aqueous solutions of chlorous acid and sodium borohydride. Cobaltous hydroxide has been shown to possess more intense catalytic activity in the hypochlorite oxidation of cellulose than nickel hydroxide, ferrous hydroxide, and manganous hydroxide reported earlier.

The redox behaviour of some Fe(III) porphyrins and hemipeptides has been investigated polarographically as a fonction of axial coordination in dimethylformamide. Low spin as well as high spin complexes exhibit three one-electron reduction steps. Two azaaromatic bases have been shown to bind the ferric prophyrins in two separate steps and the ferrous prophyrins in a single step. They are released upon reduction of the latter complexes. Histidine was shown to form more stable intramolecular complexes when bound covalently to the porphyrin.

This paper describes the iron eectrodeposition from a solution mainly composed of ferrous sulfate catholyte by using two compartment cells separated by an anion exchange membrane. In particular, it describes the effects of electrolyte conditions on current efficiencies for iron deposition on cathode and on efficiency of sulfuric acid generation in anolyte. There were close relations among the concentration of sulfuric acid in anolyte, pH of catholyte, efficiency of sulfuric acid generation, and efficiency of iron deposition. When the sulfuric acid concentration in the anolyte increased, the efficiency of sulfuric acid (generated in the anolyte passing through the anion exchange membrane from the catholyte) decreased, which led to lowering of the pH value of catholyte and also lowering of the iron deposition efficiency on the cathode. The current efficiency for iron deposition rapidly decreased when the pH value of ferrous sulfate catholyte was below 2.5. It was proposed to keep the sulfuric acid concentration in the anolyte at lower than 50g/l and to keep the pH value of catholyte at above 2.5 for the purpose of keeping the efficiency of sulfuric acid (generated in anolyte) higher and of keeping the efficiency of iron deposition (on cathode) higher.

In recent years, new electric steel mills have been built and total electric steel mill production has increased substantially in the south- eastern United States. For several years, the Southeast has been an excess producer of ferrous scrap—the basic raw material used in electric steel mill production. (1) Ferrous scrap, particularly scrap steel, can be used in varying quantities in all types of steel-making furnaces: the open-hearth, electric, basic oxygen (BOF), and Bessemer. Only electric- arc steel-making furnaces, however, are currently used in the area con- sidered by this paper, and they are charged almost exclusively with steel scrap. Electric furnace steel producers depend almost exclusively on the scrap industry for their basic raw material. Purchased scrap con- sumption for electric mills ranges from 75 to 100 percent of the total scrap consumed, depending on whether or not mill-revert scrap is con- sidered as a separate source. Cast iron is not purchased or consumed by steel mills. For the most part, it is bought and used by large foundries located in the Birmingham-Anniston, Alabama, area. STUDY AREA. This paper focuses on the functional components of the ferrous scrap industry currently providing essential raw materials for five electric steel mills located in three Southeastern states. These five steel producers are located in a relatively compact geographical area within Georgia, South Carolina, and North Carolina. Since all five mills are electric, they are dependent on ferrous scrap as a raw material. The outer boundary of their collective raw materials supply area thus serves

It has been demonstrated that oxalate ligands of trisoxalatochromate(III) and trisoxalatoferrate(III) complex anions located outside the first coordination sphere of the decayed atom are still involved in the local radiolytic processes initiated by the EC-decay. The yields of 57Fe species found in ferrous charge state were interpreted by using radiolytical data on potassium trisoxalatochromate(III) and trisoxalatoferrate(III).

The use of iron oxide sorbents to remove oxides of nitrogen (NOx) from gaseous mixtures containing small amounts of NOx such as the exhaust from an internal combustion engine or flue gases, without interference from carbon oxides or water vapor and thermally regenerable at relatively low temperatures, are disclosed. A preferred sorbent is supported ferric oxide for sorption of NOx from gaseous mixtures containing oxygen. Ferrous or ferrosoferric oxide sorbents are also suitable in the presence or absence of oxygen.

Purified NADPH cytochrome c reductase catalyzes the oxidation of NADPH in the presence of Fe3+, ADP and EDTA. EDTA in this system appears to elevate the redox potential of ferric ion and of its iron complex thereby facilitating the transfer of one electron from NADPH to tri-valent iron (more rapidly than superoxide is formed) through a flavin moiety in the reductase, but it diminishes the concentration of free iron to be required for phospholipid peroxidation. The reduction of Fe3+ by the xanthine-xanthine oxidase system is different from that manifested by the NADPH-NADPH cytochrome c reductase system in the manner in which the former is carried out in the main by Ostaggered2staggered− · generated by the substrate - O2 - enzyme interaction. Reduced iron, which is free in the solution, plays an important role for the initiation and propagation of the phospholipid peroxidation, monitored by malondialdehyde assay and light emission. In the xanthine-induced lipoxygenation system, the ·OH radical, probably produced from hydrogen peroxide by the action of Fe2+, is not involved in the initiation of the peroxidative cleavage of phospholipid in microsomal lipoprotein.

Active participation of iron in biological cycles of transformation is connected with its changeable valence and its ability to form complexes with organic compounds. All organisms use iron as a means of electron transfer in enzymatic systems, but the role of iron is most diverse in the metabolism of microorganisms, where iron may serve as an oxidizer (Fe3+) in the course of anaerobic respiration and as an energy source (Fe2). Because of the part played by iron in metabolic functions, the vital activities of microorganisms are essential factors in the mobilization and transformation of iron in soils. There are several mechanisms for mobilization of iron from stable natural compounds. However, the metabolites excreted by microorganisms into the soil as strong chemical reagents and the activities of microbial enzymes are principal factors in these processes. The biochemical activity of microorganisms, depending on environmental conditions, results in mobilization or stabilization of iron in soils. The utilization of ferrous iron as an energy source by bacteria leads to its accumulation by bacterial cells in the form of hydroxides. In the course of time, these biogenic iron deposits are transformed into ortsteins and eventually into limonite and goethite.

The formation of Fe(II)Fe(III)-intermediate green complex in aqueous solutions has been investigated. From the u.v. absorption spectra and the chemical analysis of neutral and slightly alkaline sulphate solutions of 5 × 10 −4 – 7 × 10 −4 mole/l iron at different pH's, the complex Fe(II) 1 Fe(III) 1 was found with the progress of aerial oxidation of Fe(II) species corresponding to FeOH + . The result has been used to estimate the iron composition of solid-green rust II. The participation of the green complex and green rust in the formation of Fe 3 O 4 and γ-FeOOH in corrosion process of iron in aqueous solutions was briefly discussed.

Transient effects observed in the anodic dissolution of iron using potential step methods are examined in terms of theories of the relaxation of electrochemical pre-equilibria, change in shape of etch pits, and pH changes at the electrode surface. The variation of the relaxation times and amplitudes of the transients with the experimental parameters, is compared to the theoretical predictions; the steady state behaviour at the rotating disc electrode is also examined. It is shown that the dominant contribution to the transient is the build up of ferrous ions in the diffusion layer, which results in a local increase in pH (by exclusion of H + from the diffusion layer). The mechanistic theories of dissolution of iron are reassessed, and a modified mechanism is proposed to account for the results.

1. Adult specimens of Ascaris lumbricoides of similar weights were incubated under nitrogen for 24 hours in a synthetic medium with 1 mM 2,2′-dipyridyl. 2. Under these conditions, the viability of the parasites was not affected as evidenced by the amount of ATP in the whole sample and the mobility after mechanical stimulus. 3. Incorporation of [14C]proline into non-collagenous proteins in the body wall and cuticle was reproducibly higher in 2,2′-dipyridyl-treated specimens than in untreated worms. Synthesis of collagenous hydroxyproline was inhibited in the cuticle and, to a greater extent, in the muscle layer. 4. After transferring the specimens into a fresh medium enriched with 0·1 mM ferrous ions and incubated under 70% oxygen, the muscle collagen remained underhydroxylated. The synthesis of hydroxyproline, however, was almost completely normalized in the cuticle collagen. 5. We interpret the data as further evidence of the existence of at least two different enzymes hydroxylating collagenous proline, one located in the subcuticle and the other in the muscle layer of Ascaris lumbricoides.

The chemical factors affecting the accuracy of Wilson's procedure for determination of ferrous iron in silicates have been investigated. This procedure utilizes pentavalent vanadium to oxidize ferrous iron as it is set free from the silicate by hydrofluoric acid. The quadrivalent vanadium produced is more resistant to oxidation by oxygen than ferrous iron, and conserves the reducing power of the silicate. The procedure is done at room temperature. Recovery of ferrous iron under various conditions has been studied to elucidate the chemical mechanisms of loss in the procedure. Some improvements have been made. The studies indicate that the procedure is of high accuracy. An effect resulting in loss of ferrous iron titre has been found, involving the chemical attack of solids by solutions containing oxygen and pentavalent vanadium. This loss does not appear to take place if all ion species are in solution.

An iterative technique employing computer processing of spectrophotometric data has been used to obtain the two formation constants for complexing of nitrogenous bases with Iron(II) phthalocyanine in dimethylsulfoxide. Good correlations of K f with pK BH are obtained for the first formation step with a closely related set of ligands. π-bonding does not appear as important as in similar reactions with ferrous porphyrins.

Suspensions ofThiobacillus ferrooxidans in Warburg flasks oxidized ferrous iron and coupled14CO2 fixation to the oxidation. The sulphates of zinc, cobalt, copper, nickel or uranium (0.1–1.0 M) depressed the rate of Fe2+ oxidation: nickel and uranyl ions were the most inhibitory. Uranyl, copper and nickel ions inhibited iron-dependent CO2-fixation, the two former producing a marked uncoupling effect on CO2-fixation, similar to that produced by 2:4-dinitrophenol. Molybdate also inhibited iron oxidation. Incorporation of14C-labelled amino acids and glucose was largely dependent on energy from ferrous-iron oxidation and was also strongly inhibited by uranyl sulphate. Kinetic analysis of the inhibition of iron-oxidation by uranium indicated mixed competitive and non-competitive inhibition. Little binding of238U,63Ni or59Fe toT. ferrooxidans was observed and the effects of uranium were concluded to result mainly from loose binding at sites on the cell membrane concerned with iron-oxidation and possibly the transport of other metals. Molybdate probably interfered with sulphate-dependent steps of iron oxidation. Uncoupling of CO2-fixation probably resulted in part from interference with energy metabolism and could depend on transport of uranyl ions through the cell membrane. CO2-fixation by an uraniumtolerant culture (U+) was less sensitive to uranyl-inhibition than that by the wild-type strain (U−), but iron oxidation and CO2-fixation were much more sensitive to uranium when the U− organisms were previously cultured on thiosulphate rather than ferrous iron.

In order to study the effect of conformational changes in electron-transfer reactions of Co(III)–polymer complexes, cis-[Co(III)(en)2LCl]Cl2, where the ligand L is PVI(poly-N-vinyl-2-methylimidazole) or NEI (N-ethylimidazole), was prepared. Electrontransfer reactions with ferrous sulfate or FeEDTA2− were examined mainly with respect to the effects of the degree of coordination, ionic strength, composition of reaction solvent, in relation to the conformational changes. In the reduction by FeEDTA2−, an increase in the degree of coordination of Co(III)–PVI brought about an extreme increase in its reactivity, while it was almost unity in the reduction by ferrous sulfate. With an increase in the ionic strength, the reactivity decreased due to the electrostatic shielding in the reduction by FeEDTA2−. It was noticed that the reaction of Co(III)–PVI was much more enthalpically disadvantageous due to the shrinkage of the polymer chain than that of Co(III)–NEI, when neutral salts were added. In an aqueous alcoholic solvent, an increase in the alcohol concentration accelerated the reaction with FeEDTA2−, and especially in the reaction of Co(III)-PVI, the maximum and minimum points of the reactivity were observed. On increasing the reaction temperature, the maximum and minimum points shifted to lower alcohol concentration. These phenomena are discussed in regard to the conformational changes of Co(III)–PVI.

Mossbauer spectroscopic studies show that ferric ions in low concentrations (0.05 wt%) on η-Al2O3 are unaffected by hydrogen at room temperature and can only be reduced to the ferrous state at temperatures as high as 700 °C. Ferric ions in PdFeη-Al2O3 catalysts, however, are reduced to the ferrous state at room temperature and to the metallic state at 500 °C with formation of PdFe alloys. The results of this investigation are consistent with a model in which the reduction of iron to the metallic state and formation of PdFe alloys requires contact between a palladium particle and the oxide of iron which is reduced. Hydrogen “spillover” does occur but only across the interfacial contacts between palladium particles and the iron oxide. No evidence was found to support a model, proposed by others, in which ferromagnetic iron metal is formed in reduced PdFeAl2O3 catalysts as a result of the diffusion of hydrogen over the support surface from palladium particles to an oxide of iron.

By use of radiotracer techniques, the iron self-diffusion coefficient in ferrous sulfide single crystals above 620 K was found to be D = D0δ exp {−[(81±4) + (84±20)δ]/RT}where the exponential units are kJ/mole, D0 is 1.7± 0.1×10−2 and 3.0±0.2 × 10−2 cm2 sec−1for diffusion in the a- and c-directions, respectively, and δ is the deviation from stoichiometry as given in the formula, Fe1-δS.This is a vacancy diffusion mechanism and is discussed in detail. Below 570 K the coefficient is lower than the values given by this equation because of vacancy ordering. The diffusion coefficient for sulfur is many orders of magnitude smaller than for iron. The significance of the data for the Fe−S2reaction and other examples of iron diffusion is discussed.

An unusually iron-rich, strongly peralkaline dyke occurring near the Ilimaussaq intrusion, south Greenland, is described. The dyke has developed two facies characterised respectively by the mafic assemblages pyroxene+amphibole+aemigmatite, and pyroxene+magnetite. The differences can be explained as an effect of loss of up to 4% Na1O from the magnetite-bearing facies (relative to the magnetite-free facies). The effect is in accordance with the phase relations at 1 atm in the synthetic system Na2OAl2O2Fe2O2SiO2. Continued alkali loss and magnetic precipitation will change the differentiation trend from agpaitic with iron enrichment towards miaskitic with iron depletion. It is suggested that the extreme degree of iron enrichment in the dyke resulted from the coincidence of low oxygen fugacity and strong peralkalinity tending to stabilise both ferrous and ferric iron in the liquid.

When a plant is run on threshold agents of the polyacrylic type, the resultant high brine pH can cause iron, if present, to precipitate on heat transfer surfaces as Ca(Mg 0.67 Fe 0.33 )(CO 3 ) 2 (ferroan dolomite), or as Mg 6 FeCO 3 (OH) 13 ·4H 2 O (brugnatellite). Both deposits severely inhibit heat transfer. The soluble iron contributing to these formations can be complexed by adding agents such as the phenol-substituted ethylenediamine diacetic acids. Above concentrations of 0.2 to 0.4 ppm, copper will precipitate the polymers onto heat transfer surfaces; this too can be alleviated by chelating agents. Such treatment can be costly, but fortunately only temporary where the metal ions emanate from the internal corrosion associated with acid treatment. Supersaturation of calcium carbonate and magnesium hydroxide by threshold agents will raise brine recycle pH to more than 9, eliminate carbonic acid attack and thus drastically reduce corrosion rates of copper and ferrous alloys in one to two days. Thus, the principal objective of such specific metal treatment is to “hold off” the negative effects of dissolved metals until corrosion subsides in the brine circuit.

Electrodeposited films of cobalt–iron traditionally have been thought of in terms of their magnetic properties. The current investigation, however, has demonstrated that the mechanical properties of bulk coatings of cobalt–iron alloys can be equally attractive. Bulk coating (> 100 μ) of cobalt–iron have been electrodeposited in the concentration range of 1%–12.6% Fe as a function of cathodic current density (1–10 A/dm2), electrolyte temperature (60–90 °C) and ferrous concentration in the electrolyte (0.5–5.0 g/liter Fe++). Microstructure–mechanical property relationships, including yield strengths, ultimate tensile strengths and microhardnesses, have been determined for these materials after a 15 min, 482 °C (900 °F) stress relief anneal. Room temperature yield strengths as high as 102 kg/mm2 (145 000 psi) and ultimate tensile strengths of up to 135 kg/mm2 (192 000 psi) have been obtained. The general trends indicate that lower electrolyte temperatures, and higher iron contents yield coatings with greater...

This paper describes the effect of solution pH on the passive film on iron which was investigated by ellipsometry and by cathodic reduction combined with chemical analysis. Anodic two-step passivation was employed to exclude anodic deposition of ferrous ion, resulting from anodic oxidation of iron. The film in acid solution is almost anhydrous oxide, whereas the film in neutral and alkaline solution has an outer hydrated oxide layer, whose thickness decreases with decreasing pH. The hydrated outer layer depends also on the anion present in solution. The transition layer model of the film is proposed to explain the results.

Solution of silver ion, which is stable in the presence of appropriate concentrations of ferrous and ferric salts, is reduced by ferrous salts if fluoride is added. This fact has been utilized to develop a spot test for fluoride. 2μg of fluoride ion can be detected. A method for the removal of fluoride from interfering ions is also described.

Douglas-fir and red oak wood meal, cellulose, and an 0-acetyl-4-0-methylglucuronoxylan were exposed to finely divided iron powder under conditions favorable for rusting. Analyses of the wood meal and polysaccharides following exposure indicated that rusting iron causes a decomposition of all wood constituents. Cellulose was oxidized in the presence of rusting iron to form an oxycellulose which was predominantly reducing in character. Direct depolymerization of cellulose and xylan also occurred. The deterioration was favored by an acidic environment, contrary to earlier reports that the primary degradation mechanism is alkalidependent. An iron-catalyzed oxidation of wood constituents is theorized to occur as a result of free-radical production associated with ferrous ion oxidation in the presence of organic compounds. The free radicals produced lead to the formation of hydrogen peroxide which allows Fenton-type reactions to occur.

The iron chelates of polymethyl-substituted dipyrromethenes were prepared. The ferrous ion was found to form complexes having a ligand to metal ratio of 2 : 1 with 5,5′-substituted dipyrromethenes, 3,3′,5,5′-tetramethyl- and 3,3′,4,4′,5,5′-hexamethyl-dipyrromethene. On the other hand, the ferric ion gave a complex having a 3 : 1 molar ratio of ligand to metal with a 5,5′-unsubstituted ligand, 3,3′,4-trimethyldipyrromethene. The complexes were studied by means of visible and IR spectroscopy as well as by magnetic susceptibility measurements. The iron(II) chelates were confirmed to be of high spin type with distorted tetrahedral structure (D2), while the iron(III) chelate demonstrated a low spin character with hexacoordination. The strong ligand-field bands of the latter complex was ascribed to the trigonally distorted octahedral coordination (D3) along with a high covalent nature of metal-ligand bonds.

1, 9-Diazaanthracene (IV), 4-methyl-1, 9-diazaanthracene (V), 4, 6-phenanthroline (I), 1, 6-phenanthroline (III), and 5-methyl-1, 6-phenanthroline (II) were synthesized by the reaction of 2-, 3-, or 4-aminoquinolines with glycerol or methyl vinyl ketone, in the presence of sulfo-mix, ferrous sulfate, and boric acid. Methylation of I with methyl iodide afforded the monomethiodide (VI) in which methyl iodide was proved to have reacted with the nitrogen in 6-position. Chichibabin amination of I afforded 5-amino-4, 6-phenanthroline (VIII) and this amination was examined by comparison of reaction indices by the Huckel molecular orbital method.

The effects of low-spin Fe^(2+) in the earth's lower mantle are investigated in considerable detail. The existence of low-spin Fe^(2+) permits the formation of an extra phase, since Mg^(2+) and low-spin Fe^(2+) probably do not form solid solutions. The elastic behavior of phases containing low-spin iron is predicted from bulk modulus systematics and is compared with available shock wave data. It is likely that the high pressure phases of several ferrous iron compounds involve low-spin Fe^(2+). Iron will be spin-paired in the mantle below 1700 km and perhaps at higher levels as well. The observed density and bulk modulus in the lower mantle are inconsistent with any combination of phases in a pyrolite bulk composition but can be fit quite well by a model with all Fe^(2+) spin-paired below 650 km. The lower mantle is richer in FeO and SiO_2 than the upper mantle. The spin-pairing of Fe^(2+) provides an excellent mechanism for both iron and silicon enrichment in the lower mantle by partial melting. Thus spin-pairing in iron provides support for previous arguments for chemical inhomogeneity of the mantle and also provides a mechanism for generating the inhomogeneity. This removes the motivation for reducing FeO and SiO_2 in the mantle to supply Fe and Si for the core.

A method is described for the preparation of native oxymyoglobin from bovine heart muscle. The aqueous extract is gel filtered on Sephadex G-50 to isolate myoglobin from hemoglobin. Native oxymyoglobin is then separated from metmyoglobin by DEAE-cellulose chromatography. There is a marked effect of temperature on the autoxidation of native oxymyoglobin to metmyoglobin, with Q10 values approximating 5.3 over the pH range of 5–10. The activation energies over this pH range are shown to be almost constant, i.e., 26.5 kcal·mole−1. In contrast to the suggestions in earlier reports, the autoxidation rate of native oxymyoglobin estimated at physiological pH and temperature is quite high with t12 ≤ 1.5 days under air saturation. This suggests the existence of an in vivo system(s) immediately reducing metmyoglobin formed to the ferrous state.

The 57Fe Mossbauer effect and the magnetism of the ferrous compound Fe(4.7-(CH3)2-phen)2(NCS)2 have been studied in detail between 4.2 and 298K (phen=1.10-phenanthroline). At the temperature Tc=121.5K, the Mossbauer spectrum changes abruptly and the effective magnetic moment decreases. The observations are interpreted in terms of a high-spin (5T2) to or from low-spin (1A1) transition associated with a phase change at Tc. The transition is incomplete, although only a slight contribution ( approximately 2% and approximately 4% respectively) of the complementary state remains at the highest and the lowest temperature studied. Debye-Waller factors were determined from the saturation corrected areas of the Mossbauer spectra and results provide evidence for different lattice dynamical properties at the sites of 5T2 and 1A1 ground-state iron(II) molecules in the crystal.

The possibility of the recycling of ferrous materials is examined. The percentage of ferrous in garbage, energy costs for the production of steel, and the role of scrap dealers in the recycling process are discussed. The freight rates for virgin and scrap materials are also discussed.

SUMMARY Reduced (Fe”+) carboxymethylated cytochrome c (Cmcytochrome c) reversibly binds ligands of ferrous iron, e.g. CO, cyanide, ethyl isocyanide, and oxygen, at neutral PH. Titrations of the reduced protein with CO show that over the pH range 6 to 9.5 the stoichiometry of binding is one, and that the spectrum of the Cm-cytochrome c complex with CO is practically pH-independent. The kinetics of CO binding of Cm-cytochrome c have been studied as a function of pH. At low pH values the binding process as observed by stopped flow or photolysis techniques conforms to a simple bimolecular process (2’ = 1.6 X 106M-r s-l), whereas at high pH the process, although remaining simple, it is NlOO-fold slower. At intermediate pH values, the binding of CO occurs in a biphasic reaction, the proportions of the fast and slow phases depending on the pH, on the monitoring wave length, and, in the case of photolytic experiments, on the CO concentration. The dissociation rate constants of CO from Cm-cytochrome c were measured by replacement with oxygen or ethyl isocyanide. A model is proposed in which the acid and alkaline conformers of the ligand-free protein have different ligandbinding properties. It is suggested that there is a pH-dependent transition in the CO adduct of Cm-cytochrome c and the pK of this transition is reported. The model is consistent with simple thermodynamic considerations. Binding between ferrous Cm-cytochrome c and 02 has been examined. At pH 6, a stable O2 complex, similar to myoglobin, is formed, whereas at pH 9 0% rapidly oxidized the heme iron.

At low concentrations (up to 50 mg/l) humic acid enhances cell elongation in excised pea root segments, but at higher concentrations it is inhibitory. At concentrations stimulating cell elongation humic acid has no effect on protein metabolism but does inhibit the formation of cell-wall bound hydroxyproline from proline. Humic acid does not stimulate cell elongation or inhibit the formation of cell-wall bound hydroxyproline in the presence of ferrous iron. Results similar to those of humic acid were obtained using the iron chelator αα'-dipyridyl, but γγ'-dipyridyl. which does not chelate iron. was without effect on cell elongation. The cessation of cell elongation corresponds to the time at which there is a substantial increase in cellwall bound hydroxyproline, this latter process requiring ferrous iron. Thus humic acid may enhance growth by virtue of its ability to complex ferrous iron within the plant tissues.

A model transport system is described in which iron can be quantitatively transported from an outside compartment to an inside compartment separated by an organic phase. Transport is dependent upon the presence of a ferric ionophore, ferrichrome or ferrichrome A. The metal is reduced to the ferrous state by ascorbic acid in the inner compartment and trapped by the water-soluble ferrous chelator, ferrozine. The iron-trapping mechanism provides a thermodynamic drive analogous to trapping by heme synthesis in vivo. Conditions are described which allow ferrichrome, but not ferrichrome A, to act as an ionophore. It is shown that transfer of iron from ferrichrome A to deferriferrichrome is kinetically possible, suggesting a role for ferrichrome A in vivo.

The effect of high temperature homogenization on sulfide inclusions was studied in directionally solidified AISI 4340 low alloy steel of various sulfur contents and in directionally solidified iron-carbon-manganese-sulfur alloys. The morphological modifications of the various types of inclusions caused by coarsening were investigated versus homogenization time. The decrease of the number of inclusions per unit volume of matrix, and that of the sulfide-matrix interface area per unit volume of sulfide, and the increase of the mean over-all inclusion size with homogenization time were quantitatively established. These variations were compared in a specific case with analytical predictions based on a coarsening model.

Acid gradient elution technique was used at three stages with low, medium and high acid concentrations (N/10, 5 N and 10 N HCl) successively to dissolve phosphorus components of varying solubility. Chittor soil and sand each mixed with tricalcium phosphate and ferrous phosphate were eluted by this technique. It has been possible to roughly demarcate the peaks of Al, Fe and Ca bound phosphates in the gradient elution curves.

The rates of alkaline denaturation of hemoglobin A, hemoglobin F, and isolated alpha, beta, and gamma subunits have been measured as a function of the ligand state of the heme iron. Under all conditions hemoglobin A and its isolated subunits were completely denatured before the initial measurement was made. A similar result was obtained with the high spin ferric (met) forms of hemoglobin F and isolated gamma subunits. However, in the low spin ferric (cyanmet) and liganded ferrous (oxy, carbonmonoxy) forms, hemoglobin F was partially resistant to alkaline denaturation and this resistance could be attributed to the presence of gamma subunits. In addition, the alpha subunits of hemoglobin F are more stable than those of hemoglobin A due to their association with gamma subunits. These results suggest that the above liganded forms of hemoglobin F have similar structures and this structure is different from that of the same derivatives of hemoglobin A.

Effects of percolating of water through the submerged paddy fields were analyzed by laboratory experiments. Soil samples were taken from the surface layer of three kinds of paddy soil with varying amounts of easily decomposable organic substances. The air-dried soil samples put in glass vessels were incubated under submerged conditions. One series of the submerged soil was percolated with water (percolated plot) and another series was held under stagnant water (nonpercolated plot). Complex nature of the effects of the percolating water on the soil dynamics is fairly well clarified. If a soil contains large amount of easily decomposable organic substances, both supply of molecular oxygen and removal of water-soluble toxic substances are considered to enhance microbial activities and lead to increase in formation of ammonium and ferrous iron and decrease in Eh of the soil. Meanwhile, if a soil contains small amount of easily decomposable organic substances, supply of molecular oxygen will oxidizes ...

A study was made of the initiation of polymerization of styrene in dimethylformamide with azoisobutyrodinitrile in the presence of ferric chloride. It was shown that at 70° primary radicals formed by the decomposition of the initiator do not interact with ferric chloride. With an increase in temperature to 90° the rate of this reaction increases considerably. Initiation takes place by addition of primary dimethylcyanomethyl radicals to styrene at the β-carbon atom of the vinyl group with the reduction of ferric to ferrous chloride and addition of the chlorine atom to the α-carbon atom of this group. A system was devised for the interaction of ferric chloride with extended radicals. γ-Dimethylcyano-α-chloropropylbenzene was the product of the initiation of polymerization of styrene.

There are five oxidation-reduction states of horseradish peroxidase which are interconvertible. These states are ferrous, ferric, Compound II (ferryl), Compound I (primary compound of peroxidase and H2O2), and Compound III (oxy-ferrous). The presence of heme-linked ionization groups was confirmed in the ferrous enzyme by spectrophotometric and pH stat titration experiments. The values of pK were 5.87 for isoenzyme A and 7.17 for isoenzymes (B + C). The proton was released when the ferrous enzyme was oxidized to the ferric enzyme while the uptake of the proton occurred when the ferrous enzyme reacted with oxygen to form Compound III. The results could be explained by assuming that the heme-linked ionization group is in the vicinity of the sixth ligand and forms a stable hydrogen bond with the ligand. The measurements of uptake and release of protons in various reactions also yielded the following stoichiometries: Ferric peroxidase + H2O2 → Compound I, Compound I + e− + H+ → Compound II, Compound II + e− + H+ → ferric peroxidase, Compound II + H2O2 → Compound III, Compound III + 3e− + 3H+ → ferric peroxidase. Based on the above stoichiometries and assuming the interaction between the sixth ligand and heme-linked ionization group of the protein, it was possible to picture simple models showing structural relations between five oxidation-reduction states of peroxidase. Tentative formulae are as follows: [Pr·Po·Fe-(II) $ PrH+·Po·Fe(II)] is for the ferrous enzyme, Pr·Po·Fe(III)OH2 for the ferric one, Pr·Po·Fe(IV)OH− for Compound II, Pr(OH−)·Po+·Fe(IV)OH− for Compound I, and PrH+·Po·Fe(III)O2− for Compound III, in which Pr stands for protein and Po for porphyrin. And by Fe(IV)OH−, for instance, is meant that OH− is coordinated at the sixth position of the heme iron and the formal oxidation state of the iron is four.

An investigation of high-temperature catalytic-reform ing equipment after 2.5 years of use showed the presence of deposits of sulfurous,compos ition corrosion products on the walls of pipelines made of Kh5M steel. These deposits appeared because of action on the metal of products from the high-temperature dissociation of sulfur-containing compounds contained in the reaction mixture. The catalyst's activity decreased because of the accumulation of ferric oxide. Oxide formation occurred during the initial formation of ferrous chloride during reaction with HCI and subsequent conversion to the oxide during regeneration. To decrease the formation of ferrous chloride and ferric oxide on the catalyst, it was recommended, for technical reasons, that the addition of chloroorganic compounds be limited to 0.002% chlorine content in the starting material. Industrial corrosion tests of major metallic construction materials were carried out under conditions of reactors for ordinary catalytic reforming (Table 1) and of a process with catalyst promotion by chlorine (the chlorine content in the reforming starting material was not more than 0.0005%, see Table 2). The working temperature (480~ and other process conditions practically did not differ. The test results showed that adding even 0.005% chlorine to the starting mixture practically did not affect the corrosion rate of the high-temperature equipment. The somewhat higher values of the corrosion rate in media without

The ferric ferricyanide reaction has been generally considered to depend on the reduction of ferricyanide to ferrocyanide and, in the presence of the ferric ion, the consequent production of Prussian Blue. In testing the ability of ferricyanide to prevent the azo-coupling reactions of enterochromaffin cells and of the noradrenaline islets of the adrenal medulla, ferricyanide proved to be an effective oxidant in alkaline solution, but failed to quinonize the two catechols below pH 6. Similar results are obtained in oxidative blocking of cutaneous sulphydryl sites against the ferric ferricyanide reaction and against staining by the mercaptide acid azo-coupling reaction of Lillie & Glenner (1965). Ferric ferricyanide solutions are used at pH 2–2.5 and the ferric ion is an effective quinonizing and thiol-oxidizing agent at this pH level; the ferricyanide ion is not. The ferric ferricyanide reaction depends on the reduction of ferric to ferrous ions in the presence of ferricyanide, with the production of Turnbull's Blue.

It is the purpose of this study to investigate the effects of shape of pores on toughness and ductility of sintered iron.Compacts with a density range of 5.9-7.6 g/cm3 were pressed from electrolytic iron powder and pre-sintered at 1100°C for 10 min in hydrogen. Subsequently they were infiltrated with ferrous chloride by soaking for 4 min in its melt at 750°C.Activated-sintering (or reduction of ferrous chloride) was carried out at 800°C, 950°C and 1100°C for 5 min-3 hr in hydrogen. Impact and tensile properties of these materials with round pores were compared to those of conventionally sintered ones with sharp edged pores.The results were summarized as follows.1. The roundness of the pores caused an increase in the charpy shelf energy and made the ductile-brittle transition more evident.For this reason, the impact strength of the activation-sintered iron was, at 200°C, about two times as large as that of conventionally sintered iron with the same density, but at low temperatures, smaller than that.2. Activated-sintering increased the ultimate tensile strength and the fracture strain by 10-50% over conventional sintering. But the yield strength was hardly affected by the pore shape.3. The relative strength and the fracture strain of porous materials were expressed as functions relating not only to the porosity but also to the notch effect of the pores.

The value of α, the transfer coefficient, determined using varying redox concentration ratios of the ferrous-ferric couple by the extrapolation method in the three acid media is 0·52. the values of α obtained by zero point method are 0·69 in 1·0 N H 2 SO 4 , 0·58 in 1·0 N HClO 4 and 0·54 in 1·0 N HCl. The values of the rate constant determined by the extrapolation method are of the order of 5 × 10 −2 cm/sec, 10 × 10 −2 cm/sec, 10·5 × 10 −2 cm/sec in the three respective acids. However, the k 0 a -values obtained by the zero point method differ appreciably and they are found to increase from 1·5 to 3 times in magnitude. It is found that the rate of reaction in HClO 4 is much faster as compared to that in the other two acids.

SummaryAn assessment was made of a once daily, quick release dosage form of chelated iron (equivalent to 80 mg. ferrous iron) and folic acid (350μg.) for routine prophylaxis of anaemia of pregnancy in 81 patients attending a general practice ante-natal clinic. Treatment lasted for a mean of 4.2 months. Haemoglobin levels, packed cell volume, and mean corpuscular haemoglobin concentrations were monitored before and after treatment in 47 patients, but only haemoglobin in the remainder. The preparation was shown to be an effective haematinic and proved highly acceptable to the patients, side-effects being reported in only 3 (3.7 %) patients.

The primary-metal-producing industry, which is concerned with making metal from ore rather than from waste materials and scrap, is at present undergoing major changes in the technological processes and methods which are used. In both ferrous and non-ferrous metallurgy, application of the concepts and techniques generally described as ‘process engineering’ is having important effects on the design and operation of new manufacturing capacity. In non-ferrous extractive metallurgy there are, in addition, more fundamental changes taking place. Metals are being produced by using chemical reactions which have never before been employed for this purpose. There are several reasons why new processes and the new technology associated with their use are now being accepted by an industry which is by tradition extremely conservative. These reasons must be separately identified if the relative advantages of traditional and new methods of treating a particular ore are to be understood. It is convenient to outline first the kind of process generally referred to as ‘pyrometallurgical’ taking as an example an ore containing nickel, copper and platinum metals with gold.