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Abstract  

Fission fragment angular momenta in thermal neutron induced fission of241Pu have been deduced for the first time from radiochemically determined independent isomeric yield ratios of the corresponding fission products131, 133Te and132I. The values obtained are 5.8±1.1 , 5.95±1.2 and 8.85±0.65 for131, 133Te and132I, resp. The present data along with the literature data are discussed in the light of influence of fragment nuclear structure, such as the presence of odd proton in the fragment and spherical and/or deformed neutron shell configuration.

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Journal of Thermal Analysis and Calorimetry
Authors:
Xue-Gang Chen
,
Shuang-Shuang Lv
,
Ping-Ping Zhang
,
Lu Zhang
, and
Ying Ye

surface area starts to decrease because of the closure of pores induced by the surface melting of oxides (e.g., SiO 2 , K 2 O) and formation of crystalline crystobalite. The BET surface area of WRHA that ashed at 600 and 750 °C are only 19.0 and 5.1 m 2 g

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Abstract  

Stent placement has become an effective treatment for abrupt or threatened vessel closure in recent years. As a preliminary investigation on the allergy problem towards to Ni and Cr metals from implanted stent, the release of the two elements from stents into isotonic NaCl solution was investigated. Trace amounts of Ni and Cr metals released from stents are successfully determined by neutron activation analysis (NAA). An extreme experimental condition is applied in the NAA procedure to reach a low detection limit of 1 ng Ni. A conclusion is given about the influence on the Ni and Cr release from gold coating, from the expansion, and from the different incubation periods.

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Journal of Flow Chemistry
Authors:
Klára Lövei
,
István Greiner
,
János Éles
,
Áron Szigetvári
,
Miklós Dékány
,
Sándor Lévai
,
Zoltán Novák
, and
György István Túrós

In medicinal chemistry, the development of synthetic procedures for the access of new heterocyclic systems as potential scaffolds is elementary. Herein, we report our results on the formation of small drug-like heterocycles, utilizing flow chemistry. This approach enables the extension of the reaction parameter window, including high-pressure/high-temperature or hazardous chemistry. In our work, various novel condensed tricyclic benzothiazoles fused with furo- and thieno-rings were synthesized applying a multistep continuous-flow protocol. The process includes two ring closure steps and a nitro group reduction step. Batch and telescoped continuous-flow syntheses were also designed and performed.

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Abstract  

The influence of active carbon as support on the reducibility of supported metals (Ni, Cu, Cd, Zn) has been studied by means of a temperature programmed reduction (TPR) technique. The TPR profiles indicate that active carbon behaves as a dispersion agent and the supported metal is dispersed in a disordered phase rather than as a stoichiometric compound. The hydrogen consumed in the reduction indicates that the metal residues are present in monovalent and divalent forms. High-temperature reduction peaks were also observed and are explained on the basis of metal-surface interactions and the porosity of the active carbon. Nitrogen adsorption reveals that the active carbon porosity decreases due to progressive closure of the pores when metals are supported on the surface of active carbon.

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Abstract  

Radon exhalation rate from various types of stones, used inside the living buildings, is a major factor for evaluation of the environmental radon level. To verify the significance and lethal impacts of this unknown and obscure source of radiation upon the people around the world, the exhaled radon gas concentrations from the rocks, granodiorite, granite, limestone and aragonite, and the effect of their block sizes on the exhalation rate, have been studied. The block samples, collected from their ores, were transferred to plastic containers in which the CR-39 detectors could properly be placed and air tightened, for concentration measurements. The results show the radon concentration of 7.4 ± 0.8, 6.6 ± 0.6, 0.08 ± 0.02 and 0.09 ± 0.02 kBq m−3 for granodiorite, granite, limestone and aragonite, respectively. The corresponding annual dose values in a closed environment are: 186 ± 20, 166 ± 15, 2.5 ± 1 and 2 ± 1 mSv y−1. These absorbed dose values indicate that granodiorite and granite when used inside the buildings could increase the risk of various cancers while aragonite and limestone have much lower risks and are recommended for use inside the buildings. The former ones when used in the closure areas remedial action should be implemented. The results do not show obvious dependence between the rock size of the samples and their radon exhalation rate.

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LogP values of 41 biologically active chalcones (Figure 1, 1) and their cyclic analogs, E-2-(X-benzylidene)-1-indanones (Figure 1, 2), -tetralones (Figure 1, 3) and -benzosuberones (Figure 1, 4) have been determined by an optimized and validated RPTLC method. The optimized RPTLC investigations were performed on silanized silica gel 60F254 as stationary phase with methanol–water, 60 + 40 (v/v) as mobile phase. The RPTLC method was validated by analysis of three drugs, diazepam, progesterone, and PGE1 ethyl ester, with known experimental logP values. The calibration equation used for the logP TLC calculations was: logP = 4.315RM + 1.436 (n = 11, r = 0.996, s = 0.02, F = 1089). On the basis of the logP TLC values obtained structure–lipophilicity relationships for the investigated chalcones (1) and cyclic chalcone analogs (2–4) were studied. The effects of ring closure, ring size, and the nature and the position of the aromatic substituents on the logP TLC values of the compounds are discussed.

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, Hancock , J , Harrison , J , Morris , P , Ribeiro , D , Wilson , I 2008 Nitric oxide, stomatal closure and abiotic stress . J Exp Bot 59 : 165 – 176 10.1093/jxb/erm293 . 8. Zottini

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mass loss is most likely due to the removal of residual solvent and of water formed as byproduct during imide-ring closures in PAA polymer chains being imidized. The highest rate of mass loss determined from DTG appears at 177 °C, as the minimum of this

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generates 4. The subsequent ring-closure forms cyclic carbonate. Scheme 5 Mechanism path for trans -Ru(py) 4 Cl 2 /TBAC catalyzed cycloadditionof CO 2 with PO In

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