Europium valence state in europium monoxide-iron (Cobalt) magnetic composites

2009 ◽  
Vol 54 (10) ◽  
pp. 1517-1521 ◽  
Author(s):  
N. I. Ignat’eva ◽  
A. S. Shkvarin ◽  
V. I. Osotov ◽  
L. D. Finkel’shtein
Keyword(s):  
Valence State ◽  
Magnetic Composites ◽  
Iron Cobalt ◽  
Europium Monoxide

Valence state analysis of elements by EPMA and its application

1990 ◽  
Vol 48 (2) ◽  
pp. 230-231
Author(s):  
Chen Liqing ◽  
Liu Zuqin ◽  
Zhang Wei
Keyword(s):  
Valence State ◽  
Line Intensities ◽  
Valence States ◽  
Valence Electrons ◽  
Fe And Mn ◽  
Intensity Ratios ◽  
State Analysis

Valence state analyses of Fe and Mn in oxides by EPMA have been reported in literature. In this paper, the effects of valence state on intensity ratios ILα/IKα and ILα/ILβ of Cu, Ni, Co, Fe, Mn, Cr and their oxides, and on intensity ratios ILβ2/ILα1 and ILγ1/ILα1 of Mo, Nb, Zr and their oxides were studied. It was observed that intensity ratios change with valence states in accordance with some regularities, and these effects could be utilized for analyzing the valence states of catalysts.Valence state analysis of elements by EPMA is based on the fact that changes in the states of valence electrons in the outer shells of an atom cause corresponding changes in line intensities. The M electrons of Cu, Ni, Co, Fe, Mn, Cr and the N electrons of Mo, Nb, Zr are valence electrons. Line Kα1,2 and six lines of L are produced from the transitions of K-L2,3 and L-M or L-N respectively.

Theory for the mixed-valence state

1979 ◽  
Vol 40 (C5) ◽  
pp. C5-374-C5-374 ◽  
Author(s):  
C. M. Varma
Keyword(s):  
Valence State ◽  
Mixed Valence ◽  
Mixed Valence State

MIXED VALENCE STATE OF Sm ON THE SURFACE OF AMORPHOUS La80-xSmxAu20 ALLOYS

1980 ◽  
Vol 41 (C8) ◽  
pp. C8-799-C8-802 ◽  
Author(s):  
G. Krill ◽  
A. Amamou ◽  
A. Berrada ◽  
J. Durand ◽  
N. Hassanain
Keyword(s):  
Valence State ◽  
Mixed Valence ◽  
Mixed Valence State

Tc-99m Labeled Complexes of Aldehydes and Glutamate as Cholescintigraphic Agents

1975 ◽  
Vol 14 (04) ◽  
pp. 330-338
Author(s):  
L. G. Colombetti ◽  
J. S. Arnold ◽  
W. E. Barnes
Keyword(s):  
Nuclear Medicine ◽  
Gall Bladder ◽  
Rose Bengal ◽  
Valence State ◽  
Monosodium Glutamate ◽  
Kinetic Studies ◽  
Scintillation Camera ◽  
Blood Clearance ◽  
Lower Valence ◽  
Wire Basket

SummaryTc-99m pyridoxylidene glutamate has proven to be an excellent biliary scanning agent, far superior in many respect to the commonly used 1-131 rose bengal. The preparation of the compound as previously reported by Baker et al is too time consuming and requires the use of an autoclave which is not available in most nuclear medicine departments. In our facility, we have been preparing similar compounds using several aldehydes and monosodium glutamate to make labeled complexes having the same pharmacological characteristics. The mixture of monosodium glutamate, aldehyde, and Tc-99m pertechnetate is made slightly alkaline, purged with helium, and placed in a sealed vial. The vial, which is protected by a wire basket, is then heated in a laboratory oven at 130° C for a period of 15 to 20 minutes. During this time, the technetium is reduced to a lower valence state and bound to the complex formed. Chromatographic data show that these compounds are chemically similar to that previously reported. The compounds prepared concentrate in the gall bladder of the rabbit in less than 10 minutes. Kinetic studies have been performed on dogs with a scintillation camera and small digital computer to measure rates of blood clearance, liver and gall bladder uptake, and excretion into the intestine. The aldehyde — glutamate complex promises to be a useful scanning agent for the diagnosis of biliary and hepatocellular diseases.

Environmentally Friendly Preparation of Magnetic Composites Featuring Proteolytic Properties

INEOS OPEN ◽  
2020 ◽  
Author(s):  
N. A. Samoilova ◽  
Keyword(s):  
Enzyme Immobilization ◽  
Maleic Acid ◽  
Environmentally Friendly ◽  
Synthetic Polymer ◽  
Magnetic Composites ◽  
Interpolyelectrolyte Complex ◽  
Hydrolysis Rates ◽  
Poly Ethylene ◽  
Noncovalent Binding

The enzyme-containing magnetic composites are presented. The magnetic matrix for enzyme immobilization is obtained by sequential application of an amine-containing polysaccharide—chitosan and a synthetic polymer—poly(ethylene-alt-maleic acid) to the magnetite microparticles to form the interpolyelectrolyte complex shell. Then, the enzyme (trypsin) is immobilized by covalent or noncovalent binding. Thus, the suggested composites can be readily obtained in the environmentally friendly manner. The enzyme capacity of the resulting composites reaches 28.0–32.6 mg/g. The maximum hydrolysis rates of the H-Val-Leu-Lys-pNA substrate provided by these composites range within 0.60·10–7–0.77·10–7 M/min.

Preparing Soft Magnetic Composites for Structural and Micromechanical Investigations

2017 ◽  
Vol 54 (6) ◽  
pp. 366-387
Author(s):  
T. Schwark ◽  
M. Müller ◽  
Y. Mine ◽  
T. Kreuter ◽  
O. Kraft ◽  
...  
Keyword(s):  
Soft Magnetic ◽  
Magnetic Composites ◽  
Soft Magnetic Composites

Chitosan-based Magnetic Composites - Efficient Adsorbents for Removal of Pb(II) and Cu(II) from Aqueous Mono and Bicomponent Solutions

2018 ◽  
Vol 69 (9) ◽  
pp. 2323-2330 ◽  
Author(s):  
Daniela C. Culita ◽  
Claudia Maria Simonescu ◽  
Rodica Elena Patescu ◽  
Nicolae Stanica
Keyword(s):  
Aqueous Solutions ◽  
Metal Ions ◽  
Chemical Properties ◽  
Order Kinetic ◽  
Mass Ratio ◽  
Magnetic Adsorbent ◽  
Magnetic Composites ◽  
Initial Ph ◽  
Order Kinetic Model ◽  
Physical And Chemical

A series of three chitosan-based magnetic composites was prepared through a simple coprecipitation method. It was investigated the influence of mass ratio between chitosan and magnetite on the physical and chemical properties of the composites in order to establish the optimum conditions for obtaining a composite with good adsorption capacity for Pb(II) and Cu(II) from mono and bicomponent aqueous solutions. It was found that the microspheres prepared using mass ratio chitosan / magnetite 1.25/1, having a saturation magnetization of 15 emu g--1, are the best to be used as adsorbent for the metal ions. The influence of different parameters such as initial pH values, contact time, initial concentration of metal ions, on the adsorption of Pb(II) and Cu(II) onto the chitosan-based magnetic adsorbent was investigated in details. The adsorption process fits the pseudo-second-order kinetic model in both mono and bicomponent systems, and the maximum adsorption capacities calculated on the basis of the Langmuir model were 79.4 mg g--1 for Pb(II) and 48.5 mg g--1 for Cu(II) in monocomponent systems, while in bicomponent systems were 88.3 and 49.5 mg g--1, respectively. The results revealed that the as prepared chitosan-based magnetic adsorbent can be an effective and promising adsorbent for Pb(II) and Cu(II) from mono and bicomponent aqueous solutions.

Schiff Base Metal Complexes Precursor for Metal Oxide Nanomaterial: A Review

2020 ◽  
Vol 16 ◽  
Author(s):  
Meghshyam K. Patil ◽  
Vijay H. Masand ◽  
Atish K. Maldhure
Keyword(s):  
Schiff Base ◽  
Metal Complexes ◽  
Metal Oxides ◽  
Base Metal ◽  
Carbonyl Compounds ◽  
Organic Transformations ◽  
Iron Cobalt ◽  
Methods Of Synthesis ◽  
Schiff Base Metal Complexes ◽  
Nickel Manganese

: Schiff bases and their complexes are versatile compounds, which have been synthesized from the condensation of carbonyl compounds with amino compounds and exhibit a broad range of applications in biological, medicinal, catalysis, and industrial purposes. Furthermore, Schiff base-metal complexes have been used as a precursor for the synthesis of different metal oxides, which includes oxides of iron, cobalt, copper, nickel, manganese, vanadium, cadmium, zinc, mercury, etc. and ferrites such as Fe3O4, ZnFe2O4, and ZnCo2O4. These metal oxides have been utilized for several applications, which includes as a catalyst for several organic transformations and for biological activity. This review encompasses different methods of synthesis of metal oxides using Schiff base metal complexes precursor, their characterization, and various applications in detail.

Extraction of iron, cobalt, nickel and copper with dibenzyl sulfoxide solution in toluene

1979 ◽  
Vol 44 (7) ◽  
pp. 2024-2031 ◽  
Author(s):  
František Vláčil ◽  
Huynh Dang Khanh
Keyword(s):  
Nitric Acid ◽  
Hydrochloric Acid ◽  
Distribution Ratio ◽  
Separation Factor ◽  
Chromatographic Separation ◽  
The Other ◽  
Iron Cobalt ◽  
Cobalt Nickel ◽  
Factor Α

The dependence of the distribution ratio of the metal on the concentration of hydrochloric of nitric acid was examined for Fe, Co, Ni and Cu extraction with 0.05M solution of dibenzylsulfoxide in toluene. Iron is extracted considerably more than the other metals, and is better extracted from hydrochloric acid than from nitric acid. The separation factor αFe/M (for 8M-HCl) is of the order of 104; this is not sufficient for a separation of trace quantities of iron from Co, Ni and Cu, but even at lower concentrations of HCl (e.g., 5M) the values is high enough for extraction chromatographic separation. The composition of the iron solvate extracted from HCl or LiCl medium was determined to be HFeCl4.2 B (B = dibenzyl sulfoxide).

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