Isolation and cleanup of organophosphorus insecticides and their oxones from animal tissues

The influence has been investigated of the electrode filling of carbon paste electrodes on voltammetric measurements (peak current, peak potential, current voltage curve). Greater effects have been observed with the reduction of [Fe(CN)₆]^3? and with systems with adsorptive enrichment.     

Salt and medium effects in the aquation ofcis-amminebromobis(ethylenediamine)cobalt(III) ion

Summary The aquation kinetics ofcis-[Co(NH₃)Br(en)₂]²⁺ were studied in aqueous and mixed aqueous-nonaqueous solvents in the presence of KBr, KCl, LiCl, NaNO₃ and NaClO₄ as supporting electrolytes. It was found that the association between the complex ion and Cl^–, Br^– and NO ₃ ^– ions takes place. The association constants, K_IP, were evaluated from kinetic measurements. The kinetic parameters in the studied media are related to the influence of the cosolvents on the solvation spheres of the reactants and activated complex.     

Neue Synthesen von 4,4′-Äthinylendiphenol (4,4′-Dihydroxytolan)

Zusammenfassung Es werden zwei neue Wege zur herstellung des 4,4-Äthinylendiphenols beschrieben. Der erste beruht auf der Entmethylierung des Bis-(4-methoxyphenyl)acetylens, der zweite auf der Oxydation des 4,4-Dihydroxybenzildihydrazons nach derCurtiusschen Methode.

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Two new syntheses of 4.4-ethynylene diphenol

Two new syntheses of 4.4-ethynylene diphenol are described: demethylation of bis-(4-methoxyphenyl)-acetylene, and oxidation of 4.4-dihydroxybenzildihydrazone according toCurtius.

     

A second-quantization representation of the Epstein-Nesbet partitioning of the full hamiltonian

A second-quantization representation of the Epstein-Nesbet partitioning of the total electronic hamiltonian is suggested. In this approach, the unperturbed hamiltonian contains not only the one-particle orbital energies but also the Coulomb and corresponding exchange two-particle terms. Such a hamiltonian can advantageously be used in all branches of the many-body diagrammatic perturbation theory for simple and correct inclusion of the diagonal ladder and ring diagrams in all orders of perturbation theory.     

Mathematical modeling of physico-chemical characteristics of cement-waste composites in radioactive waste management

An optimization of mortar (as matrix), improved with bentonite clay, used for immobilization of radionuclides⁶⁰Co,¹³⁷Cs,⁸⁵Sr and⁵⁴Mn, is presented. A relatively simple mathematical model is given, which permits minimization of leach rate and permeability and maximization of compressive strength. An optimal solution, based on experimental data, is given. These results will be used for a future Yugoslav radioactive waste storing center.     

Continuous electrophoretic separation of106Ru species in sea water and uptake of the separated fractions by sea algae

¹⁰⁶Ru chloro and nitrosyl-nitrato complexes in sea water were separated into several species by continuous electrophoresis on a filter paper curtain. Biological uptake experiments were carried out on sea algae Fucus virsoides with fractionated¹⁰⁶Ru chloro and nitrosyl-nitrato complex species in sea water. The biological uptake of¹⁰⁶Ru chloro complex species was about 8 times higher than the uptake of¹⁰⁶Ru nitrosyl-nitrato species. Electrophoretically most mobile electrically positively charged cationic species in both systems also showed about 8 times higher biological uptake than the most mobile negatively charged anionic species. A close relation of the biological uptake to the sign of the electrical charge and the electrophoretic mobility of the species is demonstrated. The results are discussed with respect to possible danger to the biological environment as a consequence of the aging of ruthenium species in sea water resulting from¹⁰⁶Ru waste disposal to the sea from a nuclear reprocessing plant. On leave of absence from the National Institute of Radiological Sciences, 9-1, 4-chome, Anagawa, Chiba-shi, Japan, on a fellowship from The Science and Technology Agency of the Japanese Govemment.     

Synthesis of 5-(4,6-dimethyl-2-pyrimidinyl)-1,3,4-oxadiazole-2-thione and its alkylation,aminomethylation, and acylation

The reaction of the hydrazide of 4,6-dimethyl-2-pyrimidinecarboxylic acid with potassium ethylxnthate gave 5-(4,6-dimethyl-2-pyrimidinyl)-1,3,4-oxadiazole-2-thione. The alkylation of this product in an alkaline medium proceeds at the sulfur atom, while the aminomethylation and acylation proceed at the nitrogen atom. The major criterion for the structure of the S- and N-derivatives is the chemical shift of C₍₂₎ in the 1,3,4-oxadiazole ring in the ¹³C NMR spectra.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 700–705, May, 1993.     

Einige analytische Eigenschaften von 1,3-Dimethyl-4,5-diaminouracil

Zusammenfassung 1,3-Dimethyl-4,5-diaminouracil (DAL) hat sich als sehr empfindliches Reagens zum selektiven Nachweis von Co²⁺-Ionen im stark alkalischen Medium einer Phosphatpufferlösung (p_H=11,20) erwiesen. Es wurden vier Additionsverbindungen von DAL mit den Zentralatomen Cd(II), Pd(II), Ni(II) und Co(II) im Verhältnis Me DAL=1 2 hergestellt. Spektrophotometrische Untersuchungen weisen darauf hin, daß bei p_H 6 bis 7 eine Komplexverbindung im Verhältnis CoDAL=12 gebildet wird.

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Summary 1,3-dimethyl-4,5-diaminouracil (DAL) has been found to be a very sensitive reagent for the selective detection of Co²⁺ ions in strong alkaline medium of a phosphate buffer solution (p_H=11.20). Four addition compounds of DAL with the central atoms Cd(II), Pd(II), Ni(II) and Co(II) with the ratio MeDal=12 have been prepared. Spectrophotometric studies indicate that at p_H=6–7, complex compound is produced with the ratio CoDAL=12.

     

Photochemical degradation of hyaluronic acid by singlet oxygen

Changes of the rheological properties of hyaluronic acid (sodium-magnesium salt) solutions after exposure to UV radiation indicate a vigorous decrease in their viscosity, but its still strong shear rate dependence. Whereas the presence of the singlet oxygen sensitizer (anthracene-1-sulphonic acid) brings about a loss of shear dependence; the studied solutions show newtonian behavior.     

The prediction of the behaviour of Λ-hyperon electromagnetic form factors

The behaviour of the -hyperon electric and magnetic form factors is predicted within the modified three resonance ((783), (1020), (1680)) vector-meson dominance (VMD) model with correct analytic properties and the asymptotic behaviour predestinated by the quark model for baryons. The resonance couplings to are evaluated from the known couplings to nucleons by utilizing theSU(3) symmetry and normalization conditions for Dirac and Pauli form factors. The masses and widths of the considered vector mesons are fixed at the world averaged values. The optimal position of the effective inelastic threshold, common for Dirac and Pauli form factors, is determined from the fit of the only existing Orsay DM2 point on the cross section att=5·693 GeV². The mean square charge and magnetic radii of the -hyperon are found to be r _E ² =0·018 F² and r _M ² =–0·027 F², respectively.The authors are very much indebted to Prof. R. Baldini-Ferroli for calling their attention to the problem of -hyperon e.m. ff 's in connection with the FENICE experiment.