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Charge plate technique in recoil study

IV. Effect of pyridine on the electrodeposition of128I species from (n,γ) activated iodoform pyridine mixtures

Journal of Radioanalytical and Nuclear Chemistry
Author: M. Zaman

Abstract  

The application of charge plate technique in studying the recoil reactions of128I species originating from iodoform following neutron capture in pyridine medium is discussed emphasis being placed on the problem of reactions of energetic iodine species with the radiolytically generated quasi-free electrons. Ag/AgI electrodes, under a potential gradient of 83 V·cm–1 are employed in collecting the nucleogenic iodine species from the irradiated iodoform-pyridine mixtures. It is observed that only128I species are deposited on the anode plate showing a fairly high order of radioactivity. Collected activities are increased with increasing concentration of iodoform in the system, however, no128I species are deposited on cathode surface and the activities are found nil upto the concentration range studied. It could be deduced that the recoil reactions taking place in pure iodoform are specifically influenced by the chemical reactivity of pyridine thereby govems the electrode deposition pattem in iodoform-pyridine molecular liquid mixtures.

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Abstract  

The kinetics of the oxidation of hydroquinone (H2Q), catechol (H2cat) and substituted catechols with nickel(III) macrocycle [NiL1]3+ (L1 = 1,8-bis(2-hydroxyethyl)-1,3,6,8,10,13-hexaazacyclotetradecane) has been studied spectrophotometrically in aqueous perchloric acid in the presence of sulfate. Over the pH range 1–2.6, and at higher sulfate concentration 0.05 < [SO4 2−] < 0.2 mol dm−3, the decomposition of [NiIIIL1] in the oxidation of benzenediols via [NiIIIL1(OH)(H2O)] is small. With hydroquinone, the rate constant is almost independent of the hydrogen ion concentration and with catechols, the involvement of catechol anion (Hcat) has been considered. The rate constants for cross reactions are discussed in terms of the Marcus relationship.

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Abstract  

Phase diagram of the binary system CsNO3–LiNO3 has been drawn by using simultaneously direct and differential thermal analysis between 323 and 723 K. This system is characterized by a congruent intermediate equimolar compound with melting point at 463 K, two eutectic reactions at 447 and 433 K; the eutectic points are respectively at 0,47 and 0,63 mol fraction of LiNO3; a plateau due to the phase transition of CsNO3 at 428 K and an other one at 333 K due to the formation of CsLi(NO3)2. The miscibility in solid state seems to be nil or negligible. These results associated with some other thermodynamic data have been used to calculate the activities of the constituents along the liquidus curve and the activities of the liquid constituents at 723 K. The binary liquid (Cs–Li)NO3 exhibits a negative deviation from the ideal behaviour.

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Abstract  

The thermodynamic and thermal properties of [Cu(L)2·Cl2], [Ni(L)2]·Cl2, [Co(L)2·Cl2]; L=1,2-bis(o-aminophenoxy)ethane (BAFE), complexes have been investigated. The thermal decomposition of the complexes took place in two distinct steps in endothermic reaction up to 700°C. The activation energy E, the entropy change S #, enthalpy H change and Gibbs free energy change G # were calculated from the results of thermogravimetry analysis (TG) and heat capacity from the results of differential scanning calorimetry (DSC). It was found that the thermal stabilities and activation energies of the complexes follow the order Ni(II)>Cu(II)>Co(II) and E Co<E Ni<E Cu, respectively.

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Quantitative Trait Loci (QTL) analyses were conducted in a mapping population of 91 F2 plants derived from a cross between two ahu rice cultivars of Assam, Cheni ahu (dormant, Oryza sativa ssp. indica) and Kolong (non-dormant, Oryza sativa ssp. indica) in order to identify genomic regions affecting seed dormancy and the duration of dormancy. The linkage map based on 70 simple sequence repeat (SSR) markers detected two QTLs for seed dormancy (qSD5, qSD11) and one QTL for duration of dormancy (qSDD5), and came from the dormant parent. The levels of dormancy increased with the presence of any one of the QTLs but qSD5 had larger effect on increasing dormancy, indicating that dormancy could be effectively enhanced by more than one QTL. The QTLs detected could be used to develop near-isogenic lines (NILs) for map-based cloning of seed dormancy in rice, thus to improve the understanding of dormancy of indica rice.

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Abstract  

To study the coherence of thermodynamic data of the AgNO3-LiNO3 -RbNO3 ternary system, phase diagram of the binary system AgNO3 -LiNO3 has been obtained between 303 and 550 K by direct and differential thermal analysis technique. This system is characterized by an eutectic point (25% mol. LiNO3 , 445±1 K) and a plateau due to the solid-solid transition in AgNO3 at 434±1 K. In the solid state the solubility of each component in the other seems to be nil or negligible (no more than a few percents). Using other thermodynamic data, the excess properties of the binary liquid (AgNO3 - LiNO3 ) were calculated at 623 K.

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Nine wheat genotypes differing by Rc (red coleoptile) alleles were investigated for the dynamics of seedling growth and relative anthocyanin content in the coleoptiles in response to cold. The stressed genotypes showed either reduced, similar or increased anthocyanin content compared to unstressed plants. This difference can be partially explained by the allelic state of the Rc genes. In ‘Saratovskaya 29’ weak Rc allele causes low anthocyanin content under optimal growth conditions. Upon cold treatment the level of anthocyanins decreased, whereas it increased in two near isogenic lines (NILs) with strong Rc alleles developed on ‘Saratovskaya 29’, and in some other genotypes having high anthocyanin content under optimal growth conditions. The changes in anthocyanin content correlated negatively with the changes of growth parameters in response to cold stress, suggesting the presence of some stress-dependent regulation of anthocyanin biosynthesis in wheat coleoptiles.

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Abstract

The intersection of all maximal right ideals of a near-ring N is called the quasi-radical of N. In this paper, first we show that the quasi-radical of the zero-symmetric near-ring of polynomials R 0[x] equals to the set of all nilpotent elements of R 0[x], when R is a commutative ring with Nil (R)2 = 0. Then we show that the quasi-radical of R 0[x] is a subset of the intersection of all maximal left ideals of R 0[x]. Also, we give an example to show that for some commutative ring R the quasi-radical of R 0[x] coincides with the intersection of all maximal left ideals of R 0[x]. Moreover, we prove that the quasi-radical of R 0[x] is the greatest quasi-regular (right) ideal of it.

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Anthocyanins are natural antioxidants able to scavenge free radicals, which appear in plant cells under various environmental stresses. In wheat, anthocyanin pigments can be synthesized in vegetative and reproductive organs. The objective of the current study was to estimate the significance of these substances for wheat seedlings protection under irradiation stress (after treatment of dry seeds with moderate doses of gamma-irradiation, 50, 100 and 200 Gy). For this goal a set of near-isogenic lines (8 NILs) carrying different combinations of the Pp (purple pericarp) and Rc (red coleoptile) alleles were used. The effect of gammairradiation on the growth parameters and anthocyanin content in coleoptiles was studied at the 4th day after germination. The germination rate was not affected, while roots’ and shoots’ lengths and fresh weights as well as root number decreased significantly under irradiation treatment. The effect was deeper under higher doses. Irradiation treatment also induced change of root morphology (‘hairy roots’). The effect of treatment on coleoptile anthocyanin content depended on allelic combination at the Rc loci. At the presence of ‘weak’ Rc-A1 allele anthocyanin content decreased, while it did not change in lines with Rc-A1 + Rc-D1 combination (NILs with intensively colored coleoptiles). Factors ‘pericarp color’ and ‘coleoptile color’ influenced vigor of the seedlings under 50 Gy, whereas under higher doses (100 and 200 Gy) these factors did not contribute to growth parameters changes. Statistically significant positive effect of anthocyanins synthesized in coleoptile (in the presence of Rc-A1 + Rc-D1 dominant alleles) on root growth of seedling germinated from 50 Gy-treated seeds was observed.

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Molnár E. On projective models of Thurston geometries, some relevant notes on Nil orbifolds and manifolds. Siberian Electronic Mathematical Reports , ( http://semr.math.nsc.ru ), Vol. 7, 2010, pp. 491

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