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Abstract

Heat capacity was measured for two composite systems based on silica gel KSK and calcium chloride confined to its pores. One corresponds to an anhydrous state, while another contains water bound with the salt to give the composition of CaCl2·2.04H2O. The measurements were performed in the temperature range of 6–300 K with a vacuum adiabatic calorimeter. The smoothed experimental curves C p(T) were used for calculating the calorimetric entropy and the enthalpy increment for both studied systems as well as the effective heat capacity associated only with water in the hydrated composite. The heat capacities C p(298.15 K) of both composites were compared with those calculated as a linear addition of the heat capacities of silica gel and bulk calcium chloride (or its dihydrate) with appropriate weight coefficients.

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Abstract  

In an adiabatic vacuum calorimeter, the temperature dependence of the heat capacity C p of phenylated polyphenylene and initial comonomer 1,4-bis(2,4,5-triphenylcyclopentadienone-3-yl)benzene was studied between 6 and 340 K with an uncertainty of about 0.2%. In a calorimeter with a static bomb and an isothermal shield their energies of combustion DUcomb were measured. From the experimental data, the thermodynamic functions C p 0 (T), H 0(T)-H 0(0), S 0(T)-S0(0), G 0(T)-H 0(0) were calculated from 0 to 340 K, and standard enthalpies of combustion ΔH comb 0 and thermodynamic parameters of formation-enthalpies ΔH f 0, entropies ΔH f 0, Gibbs functions ΔG f 0 - of the substances studied were estimated at T=298.15 K at standard pressure. The results were used to calculate the thermodynamic characteristics (ΔH f 0S f 0, ΔG f 0) of phenylated polyphenylene synthesis in the range from 0 to 340 K.

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Abstract  

Equilibrium adiabatic heat-capacity measurements have been made on zone refined samples of CeB6 and PrB6. Companion measurements made on LaB6, NdB6, and GdB6 have been reported elsewhere. These show cooperative lambda-type anomalies associated with antiferro-magnetic ordering. Except for lanthanum hexaboride, Schottky internal crystal field levels result in significant contributions to the thermodynamic functions. The gross thermodynamic properties at 298.15 K heat capacity (Cp/R), entropy increment (ΔT 0,m S 0/R), and Gibbs energy function are correlated with the nature of the lanthanide. For LaB6, CeB6, PrB6, NdB6, and GdB6 the three properties are, respectively: {11.654, 12.014, 11.997, 11.916, 11.695} Cp/R; {10.001, 11.803, 12.430, 12.558, 13.982} S0/R, and finally {4.379, 5.912, 6.232, 6.451, 7.905}Φ0 m/R.

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Abstract  

Heat capacity of unstable quenched solid solutions (Fe1−xNix)0.96S was measured by DSC (enthalpy method and scanning heating). According to optic microscopy and X-ray powder diffraction, the samples are homogeneous phase of NiAs type with unit cell parameters changing regularly with composition. Heat capacity changes with composition irregularly due to the difference in magnetic properties of the end members: C p/1.96R=4.1 for Fe-rich samples and 3.3 for Ni-rich ones. There is no exact limit between two types of magnetic ordering. Instead, samples with intermediate composition (0.7<x<0.8) show large fluctuations in C p due to the inconsistency of alternative (FeS and NiS) types of magnetic ordering.

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Abstract  

Adsorption isotherms and differential heats of adsorption of tetrahydropyrrol (THP) and cyclopentane CP), as well as THP and methanol mixtures (mole ratio 1∶1, 1∶2 and 1∶4) on the graphitized carbon black Sterling MT surface were determined. The influence of dilution of [THP] on its ability to undergo homomolecular association was tested. Even 1∶4 dilution of THP does not prevent is association. Methanol strongly interacts with THP in the mixed adsorbed layer forming heteromolecular associates.

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Acta Veterinaria Hungarica
Authors: Janina Skipor, Aleksandra Szczepkowska, Marta Kowalewska, Andrzej Herman, and Paweł Lisiewski

The blood-cerebrospinal fluid barrier (BCSFB) located in the epithelial cells of the choroid plexus (CP) forms the interface between the cerebrospinal fluid (CSF) and pathogen components circulating in the blood. The CP is also implicated in the passage of peripheral immune signals and circulation of immune cells into the central nervous system. Toll-like receptors (TLRs) are patternrecognition receptors that play a crucial role in the recognition of pathogens and triggering of the innate immune response. In sheep, ten members of the TLR family have been identified and cloned. We used real-time PCR analyses to examine the profiles of TLR mRNA expression in the CP of cerebral ventricles in healthy adult ewes. The transcripts for all ten TLRs except TLR8 were present; however, we observed a high variation in the degree of expression of the TLR5 and TLR1 genes (coefficient of variation: 61% and 46%, respectively) as well as a moderate variation in the expression of the TLR4 (34%), TLR2 (27%) and TLR6 (26%) genes. The TLR9, TLR7, TLR3 and TLR10 genes were the four receptors with relatively invariable expression levels (coefficient of variation: 7%, 8%, 16% and 17%, respectively) across the six adult ewes. The concentration of cortisol in blood collected prior to sacrificing the ewes ranged from 0.18 to 78.9 ng/ml. There was no correlation between cortisol concentration and mRNA expression of any of the examined TLRs. These data suggest that the CP has the potential to sense the presence of many bacterial and viral components and mediate responses for the elimination of invading microorganisms, thereby protecting the brain.

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Chemically modified acidic alumina T stationary phases have been prepared by organosilylation with the trifunctional organosilicon compounds n -octadecyltrichlorosilane, 3-mercaptopropyltri-methoxysilane, and N -(2-aminoethyl)-3-aminopropyltrimethoxysilane. These chemically modified phases were characterized by elemental analysis, measurement of specific surface area, FTIR spectroscopy, 13 C CP/MAS NMR spectroscopy, mass spectrometry, and thermal analysis. The TLC behavior of unmodified and chemically modified acidic alumina T has been tested by separation and identification of some dyes and benzo[ a ]pyrene derivatives.

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Abstract  

In this work, hydrogenation of sorbic acid to cis-hex-3-enoic acid using homogeneous Ru catalyst [Cp*Ru(sorbic acid)]Tf (Tf = CF3SO3 ) immobilized to smectite materials by means of ion exchange has been studied. The immobilized catalyst was utilized for heterogeneous hydrogenation of sorbic acid to the desired cis-hex-3-enoic acid, achieving the selectivity of up to 95% and the possibility of the catalyst to be reused.

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Abstract  

The heat capacities of Ln(Me2dtc)3(C12H8N2) (Ln = La, Pr, Nd, Sm, Me2dtc = dimethyldithiocarbamate) have been measured by the adiabatic method within the temperature range 78–404 K. The temperature dependencies of the heat capacities, C p,m[La(Me2dtc)3(C12H8N2)] = 542.097 + 229.576 X − 27.169 X 2 + 14.596 X 3 − 7.135 X 4 (J K−1 mol−1), C p,m[Pr(Me2dtc)3(C12H8N2)] = 500.252 + 314.114 X − 17.596 X 2 − 0.131 X 3 + 16.627 X 4 (J K−1 mol−1), C p,m[Nd(Me2dtc)3(C12H8N2)] = 543.586 + 213.876 X − 68.040 X 2 + 1.173 X 3 + 2.563 X 4 (J K−1 mol−1) and C p,m[Sm(Me2dtc)3(C12H8N2)] = 528.650 + 216.408 X − 16.492 X 2 + 12.076 X 3 + 4.912 X 4 (J K−1 mol−1), were derived by the least-squares method from the experimental data. The heat capacities of Ce(Me2dtc)3(C12H8N2) and Pm(Me2dtc)3(C12H8N2) at 298.15 K were evaluated to be 617.99 and 610.09 J K−1 mol−1, respectively. Furthermore, the thermodynamic functions (entropy, enthalpy and Gibbs free energy) have been calculated using the obtained experimental heat capacity data.

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Journal of Radioanalytical and Nuclear Chemistry
Authors: M. Kumar Raju, P. Sugathan, T. Seshi Reddy, B. Thirumala Rao, S. Muralithar, R. Singh, R. Bhowmik, and P. Madhusudhana Rao

Abstract  

The high spin level structure of 73As nucleus is studied by populating the nucleus in 64Ni(12C,p2n)73As reaction. Level scheme is revised significantly. Positive parity sequence is extended up to 33/2+ and a negative parity side band is identified and extended up to high spins 37/2. In addition about 15 new energy levels and a total of about 25 new gamma transitions were placed in the level scheme.

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