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The article presents data on the synthesis and antimicrobial properties of guanidine-containing carboxymethylcellulose derivatives with different physical and chemical characteristics. The regularities of the reaction of nucleophilic substitution of the aldehyde groups of modified Na-carboxymethylcellulose (Na-CMC) by guanidine under different conditions have been studied. It has been found that the maximal replacement of reactive electrophilic groups by nucleophilic reagent depends on the pH value of the medium, molar ratio of guanidine, and the degree of oxidation of cellulose ester. The azomethine derivatives with different content of nitrogen-containing fragments in the polymer chain have been synthesized by varying the reaction conditions and the number of aldehyde groups in oxidized Na-CMC. Chemical reduction of labile azomethine bonds has led to water-soluble derivatives that contain strong amino-bound guanidine groups. The study shows and substantiates the influence of structural parameters (degree of substitution, quantitative guanidine content, pKα values, and nature of counterions) of macromolecular systems on antibacterial and antifungal properties. The developed approach to the synthesis opens up prospects for the creation of antimicrobial derivatives with regulated physical and chemical characteristics and specified biologically active properties. [ABSTRACT FROM AUTHOR]

Abstract: We synthesized the reproducible heterogeneous catalyst of graphene oxide (GO)-supported palladium nanoparticles (NPs) via a simple and green process. The structure, morphology and physicochemical properties of the synthesized heterogeneous catalyst were characterized by the latest techniques such as high-resolution transmission electron microscopy (TEM), scanning TEM, energy-dispersive X-ray spectroscopy, X-ray diffraction analysis, and X-ray photoelectron spectroscopy. The GO-supported Pd NPs (Pd/GO nanocatalyst) exhibited excellent catalytic activity for the reduction of nitroaromatics to aminoaromatics in aqueous sodium borohydride. The nitroaromatics were converted to corresponding aminoaromatics with high yields (up to 99%) using Pd/GO nanocatalyst in aqueous solution. The hybrid heterogeneous catalyst showed 83% of conversion after six cycles in the reduction of nitrobenzene to aminobenzene. These features ensured the high catalytic activity of the introduced graphene oxide supported Pd nanocatalysts.Graphical abstract: [ABSTRACT FROM AUTHOR]

Physicochemical properties of the iron ore pellets depend on the iron oxide concentrate, gangue content and the amount of fluxes added. The objective of this present work is to study the reducibility as well as the softening-melting behavior of the iron ore bearing fines (mainly containing hematite) pellet with lime to silica ratio (C/S) varying from 0.9 to 2.4 in the temperature range of 1100-1400∘C. Reduction test results show that the highest degree of reduction and degree of metallization of about 95.1 and 94.3%, respectively, are achieved for pellets having C/S ratio 1.6 reduced at 1400∘C for 60 min. Further increase in C/S ratio resulted in lowering the reduction rates due to the formation of calcium ferrite phases as confirmed from X-ray diffractogram and photomicrographs. However, softening-melting characteristics study of slag (C/S above 1.6) revealed that the slag of C/S ratio 2.0 can be considered as primary slag. [ABSTRACT FROM AUTHOR]

Chlorination of 1-hydroxyindole-5,6-dicarbonitriles and 1-hydroxypyrrolo[3,4-f]indole-5,7(1H,6H)-diones with N-chlorosuccinimide afforded previously unknown 3,3-dichloro-3Hindole 1-oxides instead of the expected 3-chloro-1-hydroxyindoles. The latter, however, were prepared in good yields by treatment of the above 3,3-dichloro-3H-indole 1-oxides with piperidine in ethanol. Reduction of 3,3-dichloro-5,6-dicyano-3H-indole 1-oxides with Zn in AcOH yielded the corresponding 3-chloroindole-5,6-dicarbonitriles. [ABSTRACT FROM AUTHOR]

Cu and Al nanoparticles were prepared using a simple chemical etching method followed by a chemical reduction method. The synthesized metal nanoparticles were characterized by Fourier transform infrared (FTIR) spectroscopy, UV-visible spectroscopy, scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), high-resolution transmission electron microscopy (HRTEM), electron-dispersive (EDX) spectrum and water contact angle (WCA) measurements. The application of Cu and Al nanoparticles was tested towards the catalytic reduction of 4-nitrophenol (NiP), hexavalent chromium {Cr(VI)} and rhodamine 6G (R6G) dye in the presence sodiumborohydride (NaBH4) as a reducing agent. From the UV-visible spectrum, the reduction rate constant (kapp) and the induction time (Ti) were determined and compared critically. The HRTEM analysis confirmed the nanosize of Cu and Al prepared by a simple chemical etching process followed by the chemical reduction method. [ABSTRACT FROM AUTHOR]

The paper reports an investigation on the reduction of synthetic gypsum and a Tunisian phosphogypsum sample in pure nitrogen or loaded with H2O vapor, using graphite or natural coke. Thermogravimetry analysis in non-isothermal conditions showed that H2O gas has no effect on the onset temperature of reduction (Tred), whereas the use of coke as a carbon source lowers the Tred of about 50 °C but the reduction rate and the conversion degree into CaS are not significantly affected by the coke proportion. The activation energy and the reaction order were determined using the direct Arrhenius plot and the Coats-Redfern kinetic model. These models led to the same reaction order and to close values of activation energies. The FWO isoconversional method shows that the reduction is more complex than a one step process and leads to lower values of activation energy. Addition of 5% mass of various oxide lowered the activation energy; however, the use of the Co2O3/Co3O4 as additive seems to enhance more the reduction rate. [ABSTRACT FROM AUTHOR]

Decomposition of perchlorate (ClO4−) in subcritical water in the presence of steel slag, a by-product of the steel industry, was investigated. Reactivity of ClO4− was low in pure subcritical water state up to 300 °C, whereas adding steel slag efficiently accelerated the decomposition of ClO4− to Cl−, with no leaching of heavy metals such as chromium and other environmentally undesirable elements (boron and fluorine). When the reaction was performed in subcritical water at a relatively low temperature (250 °C) for 6 h, virtually all ClO4− ions were removed from the reaction solution. The concentration of Cl− after the reaction was well accounted for by the sum of the amount of Cl− ascribed to the decomposition of ClO4− and the amount of Cl− leached from the slag. This method was successfully applied to decompose ClO4− in water samples collected from a man-made reflection pond following a fireworks display, even though these samples contained much higher concentrations of Cl− and SO42− than ClO4−. [ABSTRACT FROM AUTHOR]

Vanadia supported on ceria shows particularly high catalytic reactivity. To elucidate its reduction site, cationic cerium-vanadium oxide clusters, CenVmOx+ (n = 1-6, m = 0-5), were generated in the gas phase and their thermal response, such as reduction by oxygen release, was investigated by gas phase thermal desorption spectrometry. Stoichiometric and near-stoichiometric CenVmOx+ clusters were dominantly formed, suggesting that Ce and V atoms in thermally stable clusters at 310 K have the oxidation states of + 4 and + 5, respectively. An oxygen molecule O2 was found to desorb from the clusters, resulting in formation of CenVmOx−2+, upon heating. Presence of more than two Ce atoms in the clusters for odd values of m, or more than three Ce atoms for even values of m lowered the desorption temperature, indicating that not V atoms (+ 5 to + 4) but Ce atoms (+ 4 to + 3) in CenVmOx+ tend to be reduced. [ABSTRACT FROM AUTHOR]

We have proposed an optimized homogeneous precipitation method for the synthesis of spherical and well-dispersed pure LnOSO (Ln = Gd, Ho, Dy and Lu) nanoparticles (NPs) using synthesized lanthanide sulfates and urea as starting materials. LnOSO NPs can be easily transformed to LnOS by reduction under H flow at 650 °C for Gd, Dy and Ho whereas the reduction with Lu gave only LuO. Particle size was between 500 nm and 3.5 µm. This reduction method allows to obtain LnOS without using HS which is highly toxic and uncomfortable gas. LnOSO/LnOS synthetized can be used for release and oxygen storage or doped with luminescent centers for multimodal medical imaging applications. Graphical abstract: [ABSTRACT FROM AUTHOR]

The reduction behaviour of the oxide scale on hot-rolled, low-carbon steel strip in 5%H-N gas at 650-900 °C was studied. In general, the reduction rate of the oxide scale at the centre location was more rapid than that at the near-edge location. In both cases, the reduction rates at 650 °C were extremely low and the rates increased with increased temperature, reaching their maxima at 850 °C. Arrhenius plot of the rate constant derived from the early parabolic stage revealed that the reduction mechanism at 650-750 °C differed from that at 750-850 °C, with the former being oxygen diffusion in α-Fe and the latter most likely iron diffusion in wustite. In all cases, a thin iron layer formed on the scale surface within a very short time and then the thickness of this layer remained essentially unchanged, while the scale layer was gradually reduced via outward migration of the inner wustite-steel interface, as a result of inward iron diffusion through the wustite layer to that interface. More rapid oxygen diffusion through the thin surface iron layer than the oxygen supply rate through interface reaction was believed to result in a lower oxygen potential at the outer iron-wustite interface, thus providing a driving force for iron to diffuse through the wustite layer. The inner wustite-iron interface became undulating initially; then with the rapid advance of some protruding sections, some parts of the wustite layer were reduced through first, and finally the remaining wustite islands were reduced to complete the reduction process. Porosities were generated when wustite islands were reduced due to localized volume shrinkage. Higher oxygen concentrations in the scales of the near-edge samples were believed to be responsible for their slower reduction rates than those of the centre location samples. [ABSTRACT FROM AUTHOR]

We have investigated the preparation of molybdenum powders by reducing the oxide compounds MoO, MgMoO, and CaMoO with magnesium vapor at residual argon pressures in the range 5-20 kPa and temperatures in the range 700-800°C. Using the MgMoO and CaMoO compounds as precursors, we have obtained molybdenum powders with specific surface areas of up to 20 m/g. The powders have a mesoporous structure. The reduction of the molybdenum compounds under such conditions was accompanied by separation of the reaction products due to the removal of magnesium oxide from the reaction zone. [ABSTRACT FROM AUTHOR]

Herein, six kinds of PdNPs (including icosahedron, sphere, spindle, cube, rod, and wire) were synthesized via simple methods. The catalytic activities were investigated by the reduction reaction of Cr(VI) and Suzuki coupling reaction. Chemically synthesized morphologies of the six catalysis were characterized by transmission electron microscopy, field emission scanning electron microscopy, and X-ray diffraction, etc. Pd icosahedron shows a better catalytic property than other PdNPs with a rate constants 0.42 min for the reduction of Cr(VI). Moreover, the electrocatalyst shows that Pd icosahedron possesses a bigger surface area of 8.56 m/g than other nanoparticles, which is attributed to the better catalyst. The Pd icosahedron possesses a better catalytic property, attributing to the abundant exposed {111} facets with high activity on Pd icosahedron. The catalytic activities are closely related to the surface area with the following order: icosahedrons ≥ sphere > rod > spindle > cube > wire. The Pd icosahedron catalyst represents a strong activity for Suzuki coupling reaction as well, outweighting is 80%. The results reveal that Pd icosahedron acts as an efficient catalyst compared to other PdNPs (wire, rod, sphere, spindle, and cube). [ABSTRACT FROM AUTHOR]

Facile reduction of p-nitrophenol to p-aminophenol by sodium borohydride catalysed by cobalt nanoparticles (CoNPs) has been discussed. A simple approach has been made to synthesize highly active and ordered structures of CoNPs. The air-stable nanoparticles were prepared from cobalt sulphate using tetrabutyl ammonium bromide as surfactant and sodium borohydride as reductant. The cobalt nanocolloids in aqueous medium were found to be efficient reusable catalysts for the p-nitrophenol reduction. Palladium nanoparticles prepared from palladium chloride and the same surfactant were found to reduce p-nitrophenol but lose their catalytic efficiency after recovery. Based on chemical and kinetic studies, an attempt has been made to elucidate the mechanism of p-nitrophenol reduction using these nanoclusters. [ABSTRACT FROM AUTHOR]

Dehydrogenation of propane to propene is one of the important reactions for the production of higher-value chemical intermediates. In the commercial processes, platinum- or chromium oxide-based catalysts have been used for catalytic propane dehydrogenation. Herein, we first report that bulk tungsten oxide can serve as the catalyst for propane dehydrogenation. Tungsten oxide is activated by hydrogen pretreatment and/or co-feeding of hydrogen. Its catalytic activity strongly depends on hydrogen pretreatment time and partial pressure of hydrogen in the feed gas. The activation of tungsten oxide by hydrogen is attributed to reduction of the metal oxide and presence of multivalent oxidation states. Comparison of the catalytic performance of partially reduced WO to other highly active metal oxides shows that WO exhibits superior catalytic activity and selectivity than CrO and GaO. The findings of this work provide the possibility for activation of metal oxides for catalytic reactions and the opportunity for the development of new type of catalytic systems utilizing partially reduced metal oxides. Graphical Abstract: [ABSTRACT FROM AUTHOR]

Oxidation state of iodide complexes of Pt and Pt in large excess of NaI with respect to platinum in water and acetone solution has been determined by means of Pt NMR spectroscopy. In acetone, iodide complexes of Pt are almost quantitatively reduced into Pt, and iodine is bound in a poorly soluble polymeric complex with sodium iodide and acetone. Iodometric titration has revealed the formation of equivalent amount of iodine. Reduction of platinum has not been observed in aqueous medium. [ABSTRACT FROM AUTHOR]

Efficient synthesis of silver nanoparticles stabilized by cetyltrimethylammonium cations (Ag@CTA) is carried out in aqueous medium by methylviologen-mediated electroreduction of silver chloride nanospheres stabilized by surface-active CTA cations (AgCl@CTA, diameter ~330 nm), on a glassy carbon electrode at potentials of the MV/MV redox couple. The nanospheres AgCl@CTA can be reduced immediately on the electrode at a low rate and the resulting metal is deposited on the electrode. In the mediated reduction, the metal is not deposited on the cathode but the quantitative reduction of AgCl to Ag@CTA nanoparticles proceeds completely in solution volume at the theoretical charge. In aqueous solution, the nanoparticles are positively charged (electrokinetic (zeta) potential is +74.6 mV), their characteristic absorption maximum is at 423 nm and the average hydrodynamic diameter is 77 nm. Isolated Ag@CTACl nanoparticles have the size of 39 ± 15 nm. The preferential form of metal nanoparticles is sphere with the diameter of 34 ± 24 nm; nanorods are also obtained in small amounts (4%); the average size of metal grains is 8-16 nm. [ABSTRACT FROM AUTHOR]

The O/Ru(0001) system is widely studied due to its rich phase variety of various stoichiometry and atomic arrangements, including the formation of a RuO/Ru(0001) oxide layer. Apart from homogeneous ruthenium surfaces in certain oxidation states, also strongly heterogeneous surfaces can exist due to oxidation state's variation at the nanoscale. We report on a scanning tunneling microscopy (STM) study of the nanostructuring of the oxidized Ru(0001) surface as a result of its interaction with molecular oxygen at elevated temperatures and subsequent reduction of a resulting RuO film by CO or HCl molecules from the gas phase in high-vacuum environment. [ABSTRACT FROM AUTHOR]

The utilization of copper slag is an attractive option of iron resource. However, extra energy consumption is required and contributes to greenhouse gases. In this paper, biomass was introduced as a new kind of reductant for the reduction of copper slag to decrease the energy consumption. The reduction kinetics and reduction characteristics of three kinds of biomasses were studied by thermogravimetric analyzer (TG). The TG curves showed the reduction reaction of copper slag and biomass could be divided into three stages during heating process: drying and pyrolysis of biomass process (<959 K), pre-reduction process (959-1100 K) and reduction reaction process (>1100 K). Pine sawdust showed the best reducing property and the reduction ratios of pine sawdust, corncob and straw reached to 80.6, 76.1, and 60.0 %, respectively, when the mass ratio of biomass/slag was 2:1. As the additive, CaO had promotion effects on the reduction reaction. With the increase in CaO addition, the reduction ratio of copper slag increased firstly and reached a peak at CaO/slag was 0.3:1 and then it declined due to the changes of slag viscosity. By kinetics analysis, the reduction reaction confirmed well with shrinking core model (R1). The activation energy of reactions was affected by the addition of biomass and heating rate in experiments. With the increase in the addition of biomass, the activation energy of reduction reaction increased gradually; with the increase in heating rate, the activation energy of reduction reaction decreased. [ABSTRACT FROM AUTHOR]

Previously unknown 1-alkyl-, 1-benzyl-, and 1-aryloxyethylderivatives of dichloroimidazoles and products of their structural transformation were synthesized from 4,5-dichloroimidazole or 2-methyl-4,5- dichloroimidazole using alkyl, benzyl or aryloxyethyl halides. These N-substituted compounds were shown to have a weak antibacterial activity against some pathogenic gram-positive and gram-negative bacteria ( Staphylococcus aureus and Escherichia coli). At the same time, some of the obtained compounds demonstrated a significant protistocidal activity against Colpoda steinii, which can exceed in strength the activity of clinically used veterinary drug Baycox. Moreover, these compounds showed a pronounced fungistatic effect. [ABSTRACT FROM AUTHOR]

The activity of cobalt-boron catalysts in sodium borohydride hydrolysis has been correlated with change of structure in the active component of the catalysts upon their thermal treatment. It was shown that at temperatures to 300 °C there takes place loss of water and hydrogen from the catalysts without noticeable changes in activity. At temperatures above 300 °C the amorphous cobalt boride particles undergo crystallization to produce metallic cobalt with a hexagonal structure and this is seemingly the cause of the substantial fall in the rate of hydrogen generation in the presence of cobalt-boron catalysts. [ABSTRACT FROM AUTHOR]

The purely aqueous-phase reduction of a wide range of nitro compounds to the corresponding amines has been carried out with NaBH in the presence of inexpensive Cu nanoparticles as catalyst. The reactions were taken place in water (80 °C) within 4-15 min to give amines in high to excellent yields. [ABSTRACT FROM AUTHOR]

Reduction of unsaturated adamantyl-containing nitriles with lithium aluminum hydride in 2-methyltetrahydrofuran was examined. It was found that under the synthesis conditions a simultaneous reduction of the double bond and the nitrile group successfully occurred. The presence of bulky substituents in the α-position to the adamantyl moiety of nitriles led to a significant increase in the synthesis duration. A satisfactory yield of the target compounds was achieved only by increasing the temperature and using a two-fold excess of lithium aluminum hydride. [ABSTRACT FROM AUTHOR]

The existing two-stage technology used to make iron and steel is based on the use of hot reducing gases, which results in the formation of waste gases and dust and creates an environmental problem. The results obtained from an analysis of metallurgical processes that involve smelting reduction are used to propose a new technology based on the smelting reduction of a monocharge contains carbon and oxides of metals. The monocharge is composed in such a way as to ensure complete reduction of the metals while also preventing their carburization. A monocharge was subjected to smelting reduction to obtain the world's first specimens of directly-made alloy steel without the intermediate conversions - the production of pig iron and metallized semifinished products. [ABSTRACT FROM AUTHOR]

Batch contact experiments with several porous carbon materials showed that carbon solids spontaneously reduce the oxidation state of plutonium in 1-1.5 M acid solutions, without significant adsorption. The final oxidation state and rate of Pu reduction varies with the solution matrix, and also depends on the surface chemistry and surface area of the carbon. It was demonstrated that acidic Pu(VI) solutions can be reduced to Pu(III) by passing through a column of porous carbon particles, offering an easy alternative to electrolysis with a potentiostat. [ABSTRACT FROM AUTHOR]

A new method for the synthesis of N-substituted 3H-imidazo[4,5-b]pyridine via chemical reduction of 1-(3-nitropyridin-2-yl)-1 H-benzimidazole in an acidic media was described. [ABSTRACT FROM AUTHOR]

We propose a short review paper on the mainly adopted techniques for the production of metal nanoparticles in industrial and laboratory scale. The methods are grouped according to the wellknown classification in bottom-up and top-down schemes, with a particular emphasis on the operating conditions specifically adopted. Namely, some aspects concerning the experimental setup, the choice of precursors and reactants and the relevant technical advantages/limitations of the methods are discussed and compared in light of the most recent issues in matter of metal nanoparticles synthesis. [ABSTRACT FROM AUTHOR]

An in situ comparative study of the reduction of Co-containing catalysts for the Fischer-Tropsch process in hydrogen and supercritical (SC) isopropanol is performed by ferromagnetic resonance (FMR) spectroscopy. According to the FMR data, the reduction of cobalt-containing oxide particles to metal in hydrogen starts at temperatures of ~360°C, which is substantially lower than a temperature of the formation of metal particles of the active phase according to powder X-ray diffraction and differential thermogravimetry data ( Т ~ 450°C). In SC isopropanol, the reduction to Co metal occurs at lower temperatures ( T ~ 245°C) as compared with the reduction temperature for these catalysts in hydrogen. It is shown that the reduction in SC isopropanol can lead to the formation of superparamagnetic Co nanoparticles with a narrow particle size distribution. [ABSTRACT FROM AUTHOR]

In methanol, FeCl reacted readily with L1H ( L1H = bis(1-isoquinolylcarbonyl)amide) and afforded a complex having the formula [Fe( L2)Cl] ( 1) { L2 = N-((1-isoquinolyl)(methoxy)methyl)isoquinoline-1-carboxamide ion}. This reaction involves reduction of one of the two carbonyl groups present in L1H to (methoxy)methyl group. A plausible mechanism for the conversion of L1H to L2 has been proposed. Determination of molecular structure of 1 confirmed this conversion. Fe(III) ion is surrounded by three nitrogen atoms of the ligand and two chloride ions, imparting a rare distorted trigonal bipyramidal NCl coordination environment. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

[Figure not available: see fulltext.] The reduction of quaternary 1-(adamantan-1-yl)pyridinium salts with sodium borohydride in ethanol gave 1-(adamantan-1-yl)-1,2,3,6-tetrahydropyridines that reacted with benzene in trifluoromethanesulfonic acid medium, leading to the formation of 1-(adamantan-1-yl)-phenylpiperidines with various spatial orientation of the phenyl substituent. The structure of the obtained phenylpiperidines was confirmed by the spectral dataset. The thermodynamic stability calculations for the conformers of phenylpiperidines were performed with the B3LYP/6-311++(d,p) method. [ABSTRACT FROM AUTHOR]

NaBH with catalytic amounts of NiB as an additive reagent reduced aromatic and aliphatic nitro compounds to the corresponding amines in high to excellent yields. Reduction reactions were carried out in HO within 3-30 min at room temperature or 75-80 °C. The catalytic activity of NiB as an additive reagent was superior to using the in situ precipitated one. Graphical Abstract: [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Three types of new bead-shaped heterogeneous nanoparticle (NP) catalysts were synthesized by simplified procedures and studied for continuous reduction of crystal violet (CV) dye. The stabilizing agent, viz., 2-acryloxyethyltrimethyl ammonium chloride (PAC) was functionalized efficiently onto the surface of insoluble poly(styrene)-co-(vinyl benzyl chloride) beads (PS-PVBC) through surface-initiated atom transfer radical polymerization (SI-ATRP) to obtain insoluble bead matrix having intense surface functional groups labelled as PS- PVBC-g-PAC. These PS-PVBC-PAC beads in turn were used as a common matrix for individual immobilization of AgNPs, AuNPs and PdNPs by following the simple chemical reaction/reduction methods to yield the corresponding bead-shaped heterogeneous NP catalysts, viz., PS-PVBC-g-PAC-AgNPs, PS-PVBC-g-PAC-AuNPs and PS-PVBCg- PAC-PdNPs. These catalysts were characterized by UV-Vis, FT-IR, SEM/EDAX and HRTEM techniques. The catalytic activity of these three types of catalysts were examined through the reduction of CV using NaBH4 as a reducing agent and it was observed that all these catalysts effectively accelerated the reaction. The superior catalyst, viz., PS-PVBC-g-PAC-AuNPs was again used for detail kinetic studies of the same reduction reaction. [ABSTRACT FROM AUTHOR]

Reduction of various aldoximes and ketoximes to the corresponding amines was carried out easily and efficiently with NaBHCN in the presence of ZrCl/nano FeO system. The reactions were carried out under solvent-free conditions at room temperature or 75-80 °C to afford amines in high to excellent yields. Graphical abstract: [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

The paper reports on reduction of cobalt oxide (CoO) to cobalt metal by low temperature hydrogen plasma. Hydrogen flow rate was varied between 1.167 × 10 to 2.5 × 10 m s at a fixed microwave power of 750 W which gave rise to increase in pressure from 1.866 × 10 to 2.933 × 10 Pa and increase in temperature of the plasma-cobalt oxide interface from 823 to 1,039 K. Reduction of cobalt oxide to cobalt occurred in steps: CoO → CoO → Co. The chemical reaction leading to reduction of cobalt oxide to cobalt is found to be first order with respect to hydrogen flow rate. The activation energy for the first stage of reduction i.e. CoO to CoO is found to be 26.2 kJ/mol and that for the second stage reduction of CoO to Co metal is 13.3 kJ/mol. [ABSTRACT FROM AUTHOR]

In this paper, the results of the study of the reduction of basic lead sulphate with a gas (CO + CO) mixture are presented. This is a secondary reaction during the reduction of lead sulphate. The change in the both lead and PbS content in the reaction products, depending on the process temperature and the composition of the gaseous phase, was established. The comparison of the rate of the reduction reaction of lead sulphate and basic lead sulphate shows that the process proceeding with a higher output is the reduction of basic lead sulphate. [ABSTRACT FROM AUTHOR]

Solvent extraction of macro amounts of Mo(V) and Mo(VI) from HCl using Aliquat 336 in chloroform was performed for the electrochemistry of Sg. The extraction reaction attained equilibrium with a shaking time of 10 s in higher than 8 M HCl. The D values of Mo(V) obtained by the electrochemical reduction of Mo(VI) were in good agreement with those obtained by the extraction of MoCl, and the D values of Mo(V) were higher than those of Mo(VI). These results suggested that the reduction behavior of Sg might be studied by electrochemical reduction combined with the present solvent extraction. [ABSTRACT FROM AUTHOR]

Competing reduction and cycloaddition products were formed in the reaction of 8,8-dimethylnaphthalene-1,4,5(8 H)-trione with a hydroxysulfinyldiene. The ratio of reduction to cycloaddition products depended on the stereochemistry of the diene and on the solvent employed, being higher in ethanol than in benzene. The ratio was also affected by the addition of Lewis acids, decreasing in the order BF = AlO > MgCl > ZnCl. The results help to explain and predict the occurrence of these competing processes in Diels-Alder cycloadditions involving quinonedienophiles. [ABSTRACT FROM AUTHOR]

We report here a simple, efficient, practical, and novel preparation method for the preparation of CdS nanoparticles. As described below, cadmium diethyl dithiophosphate has been used as a 3-in-1 precursor for the synthesis of high-quality CdS nanoparticles using a simple hydrothermal method in water. The presented CdS nanoparticles were characterized by TEM, XRD, EDX, UV and fluorescence spectrometer. The results revealed that the prepared CdS nanoparticles had a hexagonal structure. Photocatalytic reduction activity studies show that the CdS nanoparticles have highly photocatalytic activity toward the reduction of nitrobenzenes to aminobenzenes using sunlight as a light source. Reusability of prepared CdS nanoparticles was successfully examined for three times with very slightly loose of photoactivity. Graphical abstract: A simple and practical process for the preparation of hexagonal CdS nanoparticles by hydrothermal decomposition of cadmium O, O′-diethyl dithiophosphate (3 in 1) in water and uses in photoconversion of nitrobenzenes to aminobenzenes.[Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

The magnetic behavior of very fine metallic Ni (Ni) particles dispersed in a matrix of 10 % by mol (m/o) YO-stabilized ZrO (10YSZ) was examined. Specimens that nominally contained 0.1, 0.5, and 1 m/o Ni were prepared by a high-purity chemical synthesis method followed by a reduction treatment in H. A 0.5 m/o Ni specimen was also made by heating in vacuum, within a carbon environment. dc and ac susceptibility measurements revealed the presence of superparamagnetic Ni as well as Ni. A Stoner-Wohlfarth formulation was applied to determine that the average Ni particle size was between 4 and 7 nm, and this was confirmed by transmission electron microscopy. The activation energy for single-domain particle spin reversal and K, the effective anisotropy constant, were determined. K was higher for the vacuum heat treatment specimen because it contained less residual organic material, and therefore a higher density of Ni particles. It is shown that it is possible to make very fine Ni particles in YSZ via a direct conversion from Ni nitrates. [ABSTRACT FROM AUTHOR]

The reduction of Pu(VIII) with water in ozonized 15 and 6 MNaOH solutions after termination of the ozone bubbling was studied by spectrophotometry. Kinetic curves reflecting the whole set of processes that occur in NaOH solutions of different concentrations were obtained. Calculations performed with the experimental curves made it possible to construct the kinetic curves describing the behavior of plutonium in higher oxidation states in solution and to obtain the individual absorption spectra of Pu(VII) and Pu(VIII). The processes occurring in ozonized solutions of Pu(VI) in 6 and 15 M NaOH after termination of the ozone bubbling were found to occur by different mechanisms, yielding in 4 days Pu(VI) and Pu(V), respectively. [ABSTRACT FROM AUTHOR]

The mechanism of reducing silver(I) oxide particles to silver metals was studied using myristyl alcohol as a reducing agent. The reduction temperature of silver oxide with myristyl alcohol decreased to 150 °C from the temperature of silver oxide in air, 400 °C. The reduction temperature was decreased by myristyl alcohol reacting with silver oxide, which was confirmed by our reaction equation model obtained by gas chromatography determination, pyrolysis gas chromatography-mass spectrometry, and Karl Fischer titration. An endothermic of 153.7 kJ mol in the reduction of silver oxide with myristyl alcohol calculated from the reaction model using Hess's law was coincident with that obtained experimentally by differential scanning calorimetry measurements. [ABSTRACT FROM AUTHOR]

Nanoscale zero-valent iron (nZVI) was synthesized and used for the removal of Sb(III) and Sb(V) from aqueous solutions. Results showed that more than 90 % of antimony would be removed in 15 min and that all of antimony could be removed with appropriate nZVI dosage in 90 min. The influence of pH value and possible impurities was investigated. The pH of 4 was found as the optimum pH. Discussion and speculation about the mechanism were presented according to X-ray photoelectron spectroscopy and transmission electron microscopy data. A sheet-like structure was observed after a 90-min reaction, and antimony was detected on the surface by energy-dispersive X-ray spectroscopy. Both Sb(III) and Sb(V) partially reduced in the process. The presence of humic acid transformed the morphology of nZVI but barely influenced the removal efficiency. Competing ions showed diverse influence between Sb(III) and Sb(V). The overall results indicated that nZVI was an efficient and suitable material for the removal of antimony. [ABSTRACT FROM AUTHOR]

The relative stability of different oxidation states of actinide elements is influenced by the nature of complexes formed and redox equilibria in aqueous/non-aqueous solutions. The reduction/stripping studies on Pu(IV) ions from loaded organic phases of 1.1 M tributyl phosphate and of 1.1 M N,N-dihexyl octanamide in n-dodecane were studied using organic soluble tert-butyl hydroquinone (TBH) and aqueous soluble reductants like acetaldoxime (AX) and hydroxyurea (HU). These studies were carried out as a function of reductant and nitric acid concentration (0.5-4 M HNO) and of time. The changes in Pu oxidation states were followed by spectrophotometry for TBH and by distribution ratio values for AX and HU as reductants. Spectrophotometric investigations using TBH as reductant showed that it was desirable to strip Pu(III) formed after reduction of Pu(IV) in the organic phase, which may otherwise be reconverted to extractable Pu(IV) by in situ generated HNO from oxidative degradation of TBH to tert-butyl quinone. Similarly, the biphasic reduction/stripping of Pu(IV) using AX and HU as reductant rate was affected adversely with increased aqueous phase acidity. This data will help in the accurate simulation of Pu separation processes using these reductants in mixer-settlers/pulsed columns or centrifugal contactors. [ABSTRACT FROM AUTHOR]

This paper analyses Richard Bader's 'operational' view of quantum mechanics and the role it plays in the the explanation of chemistry. I argue that QTAIM can partially be reconstructed as an 'austere' form of quantum mechanics, which is in turn committed to an eliminative concept of reduction that stems from Kemeny and Oppenheim. As a reductive theory in this sense, the theory fails. I conclude that QTAIM has both a regulatory and constructive function in the theories of chemistry. [ABSTRACT FROM AUTHOR]

The purpose of this study was to investigate the reduction behavior of cold-bonded composite pellets produced from low-grade hematite iron ore using molasses solution at various concentrations, as well as their physical and chemical properties. Direct-Reduction Iron (DRI) technology makes it possible to assess low-grade iron ores and convert them into scrap at facilities that have electric arc furnaces. The reductant used was coke with fixed carbon of 86.04%. The alkalinity rate was adjusted to 0.7 by adding calcium carbonate. In the composite pellets produced, the 300 N/pellet compression strength recommended in the literature was achieved with a Fe/C ratio of 2.5 and 3 using a 50% concentrated molasses solution. Composite pellets prepared with a Fe/C ratio of 3.5 using a 40% concentrated molasses solution reached a compression strength of 496 N/pellet. The porosity is inversely proportional to the increase in compression strength and binder concentration. Reduction experiments were conducted by applying different temperatures and durations to samples possessing optimum conditions for each Fe/C ratio: the best result was achieved with a 88% reduction rate in composite pellets with a Fe/C ratio of 3.5 at the end of 1 h. Pig iron nuggets were characterized using an optical microscopy (LOM) and a scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS). [ABSTRACT FROM AUTHOR]

We studied the temperature-programmed reduction by NH (NH-TPR) as a supplement to the temperature-programmed reduction by H (H-TPR) for the characterization of supported Cu species. The NH-TPR profile of Cu/SiO, which contained only bulk CuO, exhibited two peaks for N formation in equal amounts, suggesting stepwise reduction of the bulk CuO. In contrast, the H-TPR profile exhibited only one H consumption peak. We also studied Cu-NaZSM-5 samples with various Cu and Na loadings. The Cu ions on ZSM-5 were reduced to Cu but no further. Kinetic analysis revealed that the NH-TPR profile exhibited peaks for separate reductions of isolated and binuclear Cu ions. Thus, we found NH-TPR to be useful for detailed analysis of the reducibility of Cu to Cu in zeolite pores. [ABSTRACT FROM AUTHOR]

An improved method was developed for preparation of 5,6,7,8-tetrahydrofolic acid (THF) and calcium-5-methyltetrahydrofolate (5-MTHF-Ca) by reduction of folic acid using KBH catalyzed by Pb(NO). The yields of THF and 5-MTHF-Ca were 56.5 and 42.7 %, respectively. A convenient method for measurement of THF and 5-MTHF-Ca using liquid chromatography-mass spectrometry (LC-MS) was also established, enabling analysis of those folates within 10 min without application of gradient elution. [ABSTRACT FROM AUTHOR]

Green reduction of graphene oxide (GO) was performed using ascorbic acid (AA) in the presence of poly(sodium 4-styrenesulfonate), which resulted in reduced graphene oxide (PSS-rGO) with excellent solubility and stability in water. Large rGO sheets of 4 μm area and 1.1-nm thickness were obtained. The measurements showed that noncovalent functionalization with PSS molecules prevented rGO from aggregation. The parameters of graphite oxidation process and AA:GO w/w ratio were evaluated, and the obtained results showed that the properties of the reduced material (PSS-rGO) can be tailored by proper selection and adjustment of these parameters. [ABSTRACT FROM AUTHOR]

The reduction of dodecyl iodide, as model compound, with a series of lanthanoid (Ln) metals in the presence of catalytic amounts of samarium diiodide (SmI) has been investigated in detail. The reducing activity of SmI/Ln and the kinds of reduced products were found to be dependent on the individual Ln, but not on SmI. [ABSTRACT FROM AUTHOR]

The promoting effect of ultrasound on the selective reduction of nitroarenes to N-arylhydroxylamines by use of Zn in an environmentally benign CO-HO system has been demonstrated. The yield of N-phenylhydroxylamine reaches 95 % when the reaction is carried out with a Zn-to-nitrobenzene molar ratio of 2.2 under ultrasound (40 kHz) at 25 °C and normal pressure of CO for 60 min. Application of ultrasound to the reaction has the advantages of higher yield of N-arylhydroxylamines, shorter reaction time, and consumption of less Zn. [ABSTRACT FROM AUTHOR]

This paper describes results of the first field demonstration conducted to evaluate an innovative in situ chemical reduction technology to rapidly degrade 81 m of high concentrations of explosives contaminated soils at Ravenna Army Ammunition Plant, Ravenna, Ohio, USA. The primary explosives of concern and associated baseline levels of contamination were 2,4,6-trinitrotoluene (TNT) (383 mg/kg), hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) (180 mg/kg), and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) (15 mg/kg). The in situ chemical treatment process involved selected reductant of sodium hydrosulfite (NaSO) at optimal pH (9-10) with appropriate buffers (e.g., sodium bicarbonate and potassium carbonate) that, when mixed with water, generate free radicals that react very rapidly to degrade nitroaromatics to carbon dioxide (CO), formate (HCOO-), and gaseous nitrogen compounds (NOx). Significant reductions in TNT, RDX, and HMX (>95 %) were observed within 24 h and achieved response complete in under 2 weeks after in situ application of the buffered sodium hydrosulfite. [ABSTRACT FROM AUTHOR]