Determination of the secondary well in the 62P12 CsXe potential

Experimental data existing in the literature on broadening and shift at low densities and on position of the red satellite band of the D₁ line of Cs perturbed by Xe are used to obtain information on the range 6Å-∞ of the difference potential. Assuming a Lennard-Jones (n-6) model, best agreement is obtained for n=8 and n=7, in accordance with the low curvature expected for a secondary well. Potential for the first excited state is obtained by addition of the difference potential to the ground state potential, and the parameters of the resulting secondary well are given.     

Reaction of (−)-carvone with phenylmethanethiol in the presence of basic Csβ-zeolite

Reaction of (−)-carvone with phenylmethanethiol in the presence of basic Csβ-zeolite gave products of hetero-Michael addition. Two stereoisomeric products of addition of phenylmethanethiol at the endocyclic double carbon-carbon bond of (−)-carvone were isolated and characterized.     

The calculation of Cs and Rb conductivities in the region of liquid–plasma transition

The conductivity and thermal conductivity of Cs and Rb are calculated in the liquid phase and in the region between the plasma (gas) and the liquid states. The last area is located at the temperatures higher than the critical one, near the critical point. The Ziman formalism originated from the liquid metal theory was used for the calculations. The results of present calculations were compared with available experiments and calculations of other researchers. It was found that the liquid state formalism can be applied to expanded liquid Cs and Rb at densities higher than the critical one, but another type of models is necessary at lower densities.     

Mössbauer spectroscopy of133Cs following the decay of133Xe atoms implanted in metals

Mössbauer effect measurements for the 81 keV transition in¹³³Cs have been performed with¹³³Xe-implanted sources prepared by means of an electromagnetic isotope separator. The behavior of the isomer shift of¹³³Cs impurities was studied in various metals. Some correlations were found between measured isomer shifts and electronic properties of the host materials, and they show that the host conduction electrons have an important role in the determination of the isomer shift in metals.     

Determination of the leaching rate of radionuclide 134Cs from the solidified radioactive wastes in Syrian Portland cement and cement–microsilica matrixes

The suitability of Syrian Portland cement for disposal of solidified low-level radioactive waste was assessed by measuring the leaching rate of ¹³⁴Cs. In ordinary cement concrete, a leaching rate of 1.309 × 10^?3 g/cm² per day was measured. Mixing this concrete with microsilica reduced significantly the leaching rate to 3.106 × 10^?4 g/cm² per day for 1% mixing, and to 9.645 × 10^?5 g/cm² per day for 3% mixing. It was also found that the application of a latex paint reduced these leaching rates by about 10%. These results, along with mechanical strength tests (under radiation exposure, high temperature, long water immersion and freeze–thaw cycling) indicate that Syrian Portland cement is suited for the disposal of low-level radioactive waste.     

On variations of volumetric activity of 90Sr and 137Cs in the Baltic Sea coastal waters near the shore of Lithuania in 2005–2009

The article presents the measurement results of the volumetric activity (VA) of artificial radionuclides ⁹⁰Sr and ¹³⁷Cs in the coastal waters of the Baltic Sea near the Curonian Peninsula in 2005–2009. The annual average values for this period of time were 12 Bq/m³ (⁹⁰Sr) and 40 Bq/m³ (¹³⁷Cs). Considerable variations in the VA of the radionuclide in individual measurements compared to the average results were observed. The extreme values were 6 and 16 Bq/m³ for ⁹⁰Sr and for ¹³⁷Cs—27 and 75 Bq/m³. It is proposed to allow such variations under the influence of a variety of external factors such as hydro meteorological situations, inflowing rivers and bays, storm activity and etc. Besides, a possibility of penetration of radionuclides into the sea waters from the additional radioactive sources is not excluded.     

Study of the cutting triangle NaF–KCl–CsCl of the quaternary reciprocal system Na,K, Cs||F,Cl

The quaternary reciprocal system Na, K, Cs||F, Cl was partitioned into simplexes by a geometric method. A tree of phases of the system was constructed, which has a linear structure and comprises three stable tetrahedra divided by two cutting triangles. The cutting triangle NaF–KCl–CsCl was experimentally studied by differential thermal analysis. The composition and melting point of a eutectic alloy in the stable triangle were determined.     

Nonadiabatic collision model calculations of ion-pair formation cross sections of Cs+O2→Cs++O2-

This paper has improved Hickman's nonadiabatic collision model by substituting Hickman's constant velocity classical straight line trajectory approximation with the solution of motion equation mR=-dV(R)/dR, and has calculated the cross sections of ion-pair formation Cs+O2 -Cs++O2- with the improved nonadiabatic collision model (INCM). A comparison of our results with other theoretical and experimental results has been made.     

The evaluation of 137Cs radioactivities in soils taken from the Babia Góra National Park

The aim of this work was to determine ¹³⁷Cs and ⁴⁰K radioactivities in soil samples taken from the Babia Góra National Park (BPN) in south Poland. The cluster analysis (CA) and principal component analysis (PCA) were used to discuss the obtained data. 10 cm thick soil cores were collected from the BPN area. Each sample was divided into three sub-samples. The samples were dried, homogenized and packed in polyethylene containers. The radioactivities of ¹³⁷Cs and ⁴⁰K were measured by means of gamma spectrometry. It was found that ¹³⁷Cs radioactivity in the whole 10 cm soil cores was in the range from 1,916 to 28,551 Bq m^?2. The radioactivity of ⁴⁰K varied from 1,642 to 25,654 Bq m^?2. Using CA it was possible to diverse the soils taking into account soil types. By use of the PCA method, it was chosen three factors which are appropriate to characterize researched parameters.     

Charge exchange of O2+ with Cs: spectroscopy and predissociation pathways for the Πg Rydberg states of O2

Electron capture by keV O₂⁺ (X₂Π_g) ions from Cs atoms yields predominantly the ¹Π_g and ³Π_g Rydberg states of O₂ which subsequently predissociate. Through the use oftranslational spectroscopy on the neutral product atoms, we have located a number of vibrational levels of these states and determined the dissociation channels. Furthermore we have observed competition between diabatic and adiabatic behaviour in the dissociating channels.     

Allosteric effects in norbadione A. A clue for the accumulation process of 137Cs in mushrooms?

A fruitful combination of potentiometry, absorption spectrophotometry, ESMS and 1H NMR enabled the characterisation of two caesium complexes with norbadione A and the determination of the respective stability constants of a mononuclear and a dinuclear caesium complex at pH approximately 6; a preliminary study allowed the assignment of five protonation sites of this pigment; a positively cooperative binding of the second Cs+ cation was observed.     

137Cs in Biota and Sediment Samples from Turkish Coast of the Black Sea, 1997–1998

During the periods of 1997–1998, macroalgae, sea snail, mussel, fish and sediment samples were collected from different stations at Turkish Black Sea coast in order to determine activity levels of ¹³⁷Cs radionuclide. ¹³⁷Cs activity in the tested algae species and in soft parts of mussel and sea snail, were found to be below the lower limit of detection. On the other hand, the ¹³⁷Cs concentration in muscle tissue of the sea snail samples were found from 6±2 to 19±7 Bq·kg^–1 dry weight. The range of the ¹³⁷Cs concentration in anchovy fish muscles were found between 4±2 – 10±5 Bq·kg^–1 dry weight. The ¹³⁷Cs concentration in the whiting fish muscle was found below the lower limit of detection. However, this activity found in shad fish muscle to be 25±10 Bq·kg^–1 dry weight. The concentrationsof the ¹³⁷Cs activity in the sediment samples proved that the eastern region of the Black Sea was affected by Chernobyl at a very high degree compared with the western part. The measured ²³⁸U, ²³²Th and ⁴⁰K concentrations in sediment samples are within the range of the cited values in the previous works at the Turkish Black Sea coast.     

Ammonia Formation on (Ru + Cs)/C Catalysts by the Interaction of Adsorbed Nitrogen with Hydrogen That Diffused from the Bulk of Cesium–Ruthenium Particles

The high-temperature (T _max = 625 ) and (T _max = 750 ) states of ammonia and (T _max = 550–750 ), (T _max = 750–900 ), and (T _max > 900 K) states of hydrogen were detected on (Ru + Cs)/C catalysts for ammonia synthesis activated under the reaction conditions (P = 30 atm; T = 650 K; the initial pressure ratio P_{N 2}/P_{H 2} = 1/3). A mechanism was proposed for the formation of ammonia as a result of the interaction of chemisorbed nitrogen with hydrogen that diffused from the bulk of cesium–ruthenium particles.     

Synthesis of heterocyclic compounds using basic zeolite Csβ*

The application of the basic zeolite Csβ as catalyst for the interaction of methyl vinyl ketone (MVK) with 5-methoxybenzimidazole-2-thiol leads to a Michael heteroreaction exclusively at the N-nucleophilic center with the formation of a fairly unusual product of di-addition of MVK to thiol. The reaction of 1,2,4-triazole-3-thiol with MVK in the presence of zeolite Csβ proceeds both at the S- and also at the N-nucleophilic center and leads to the formation of products of mono- and diaddition according to Michael, and also to the product of heterocyclization. On interacting crotonaldehyde with salicylaldehyde in the presence of Csβ 2-methyl-2H-chromene-3-carbaldehyde is formed.     

Electron Transfer in the Cs⊂{Mn4Fe4} Cubic Switch: A Soluble Molecular Model of the MnFe Prussian-Blue Analogues

A mixed-valence {Mn^II₃Mn^IIIFe^II₂Fe^III₂} cyanide-bridged molecular cube hosting a caesium cation, Cs⊂{Mn₄Fe₄}, was synthesized and structurally characterized by X-ray diffraction. Cyclic-voltammetry measurements show that its electronic state can be switched between five different redox states, which results in a remarkable electrochromic effect. Magnetic measurements on fresh samples point to the occurrence of a spin-state change near room temperature, which could be ascribed to a metal-to-metal electron transfer converting the {Fe^II−CN−Mn^III} pair into a {Fe^III−CN−Mn^II} pair. This feature was only previously observed in the polymeric MnFe Prussian-blue analogues (PBAs). Moreover, this novel switchable molecule proved to be soluble and stable in organic solvents, paving the way for its integration into advanced materials.     

On the fine-structure dependence of the Cs(7p, 2P12,320)+H2→ CsH+H reaction cross section

The experimentally observed effect of the Cs¹ fine-structure level on the title reaction is reproduced by a rough (collinear, one dimensional) dynamical treatment using accurate long-distance entrance channel potentials, as obtained from an effective Hamiltonian method, and hemiquantal dynamics in the collision energy range 0.03 to 0.13 eV. The system is shown to behave adiabatically at large distances, to undergo a transition from adiabatic to diabatic behaviour with respect to spin-orbit coupling in the 11–8.5 au Cs-H distance range, and to transfer adiabatically the whole ²Σ⁺ weight of the electronic wavefunction into theionic channel in the harpooning region.     

Transition dipole moments between the low-lying Ω(g,u)(+∕-) states of the Rb2 and Cs2 molecules

For the Rb(2) and Cs(2) molecules, the adiabatic potential-energy curves and the transition dipole moments of the 43 Ω((+∕-)) (g,u) low-lying states dissociating adiabatically to the limits up to ns+(n-1)d (n = 5,6 for Rb(2) and Cs(2), respectively), have been computed as a function of the internuclear distance R for a large and dense grid. Each molecule was treated as a two-electron system. We used an ab initio approach involving a relativistic non-empirical pseudo-potential for Rb and Cs cores, core-valence polarization potentials, and full valence configuration interaction calculations for the two valence electrons. Spin-orbit effects were taken into account through semi-empirical spin-orbit pseudopotentials. Equilibrium distances, transition energies, rotational constants, and harmonic frequencies as well as depths of wells and heights of barriers are reported for all the molecular states investigated in Hund's cases (a) and (c). Extensive tables of energy values and transition dipole moments are given in an auxiliary (EPAPS) files as a database for future studies on Rb(2) and Cs(2).     

Contents of238Pu,239,240Pu and137Cs in sediments and shore depositions of the Vltava river in 1995–1996

The²³⁸Pu,^239,240Pu and¹³⁷Cs concentrations in sediments and shore deposition samples of the Vltava river were determined.^239,240Pu and¹³⁷Cs concentrations in sediment samples (five locations) ranged from 19.6 to 124.8 mBq·kg⁻¹ and from 1.8 to 28.2 Bq·kg⁻¹, respectively. The²³⁸Pu,^239,240Pu and¹³⁷Cs concentrations in shore deposition samples (four locations) ranged from 2 to 16.8, from 26.8 to 477.2 mBq·kg⁻¹, and from 1.6 to 86.3 Bq·kg⁻¹, respectively. The superficial activity of studied radionuclides in shore deposition areas was determined and radionuclide origin at studied locations was discussed.     

Anionic polymerization of ϵ-caprolactam-lix effect of the ratio of reacting components,of the medium and of the ring size on the initial stage of the anionic polymerization of lactams

Effects of the concentrations and ratio of reacting components and of temperature on the kinetics of reaction of N-propionyllactam (I) with potassium salt of lactam (KL) were studied for derivatives of ϵ-caprolactam, 8-octanelactam and 12-dodecanelactam. For ϵ-caprolactam, the initial rates of propagation, acylation of open-chain amide groups and condensation of growth centres were estimated. At the ratio of the starting components [I]₀/[KL]₀ = 0.5-3, the participation of the polymerization reaction is constant, amounting to ca 45% of the overall consumption of 1. The condensation reaction is 14–36% of the total consumption of I; its initial rate passes through a maximum at [I]₀/[KL]₀ = 2. With increasing permittivity of the medium, the total rate of consumption of I increases; in two media with the same bulk permittivity, however, the rates may differ by as much as one order of magnitude.