The flame-retardation of Pyrovatex CP on cellulose substrate has been studied. Since levoglycosan, responsible for the fiammability of cellulose, is formed in the main decomposition process by dehydration, the amounts of water vapour released from untreated and treated cellulose during this process were measured. The water contents of the decomposition products obtained in thermal measurements were absorbed in dioxan and determined dielectrometrically.
Authors:Z. Zhang, T. Cui, J. Zhang, H. Xiong, G. Li, L. Sun, F. Xu, Z. Cao, F. Li, and J. Zhao
The molar heat capacities of the room temperature ionic liquid 1-butyl-3-methylimidazolium hexafluoroborate (BMIPF6) were measured by an adiabatic calorimeter in temperature range from 80 to 390 K. The dependence of the molar heat capacity
on temperature is given as a function of the reduced temperature (X) by polynomial equations, CP,m (J K−1 mol−1) = 204.75 + 81.421X − 23.828 X2 + 12.044X3 + 2.5442X4 [X = (T − 132.5)/52.5] for the solid phase (80–185 K), CP,m (J K−1 mol−1) = 368.99 + 2.4199X + 1.0027X2 + 0.43395X3 [X = (T − 230)/35] for the glass state (195 − 265 K), and CP,m (J K−1 mol−1) = 415.01 + 21.992X − 0.24656X2 + 0.57770X3 [X = (T − 337.5)/52.5] for the liquid phase (285–390 K), respectively. According to the polynomial equations and thermodynamic relationship,
the values of thermodynamic function of the BMIPF6 relative to 298.15 K were calculated in temperature range from 80 to 390 K with an interval of 5 K. The glass transition
of BMIPF6 was measured to be 190.41 K, the enthalpy and entropy of the glass transition were determined to be ΔHg = 2.853 kJ mol−1 and ΔSg = 14.98 J K−1 mol−1, respectively. The results showed that the milting point of the BMIPF6 is 281.83 K, the enthalpy and entropy of phase transition were calculated to be ΔHm = 20.67 kJ mol−1 and ΔSm = 73.34 J K−1 mol−1.
The temperature dependence of the thermal properties (specific heat,Cp, thermal diffusivity,a, and thermal conductivity,K) of endellite clay has been investigated over the temperature rangeR·T⩽T≲/280 °C using the plane temperature wave technique. The experimental results showed that in the initial stage of temperature rise botha andK diminish exponentially with increasing temperature up to ∼100 °C. Above 100 °C, the thermal parameters are found to reach stable values, namely,Cp=0.22±0.008 cal g−1 deg−1,a=(5.0±0.18)−10−4 cm2 sec− 1 andK=(2.2±0.16) · 10−4 cal cm−1 sec−1 deg−1. The explanation of the results was supported by using DTA and TG analysis.
Two wheat-infecting isolates of WDV-WDV-B and WDV-F-
were collected in the field of Martonvásár and Nagykovácsi.
The complete genomes were amplified by PCR, cloned into pBKS+ plasmid and
sequenced. The nucleotide divergence in the total genome of the five isolates-WDV- Fra, WDV-Cz, WDV-Swe, WDV-B and WDV-F-originating from different part of Europe were found to be
0.44-1.69%. The four genes-
MP, CP, RepA and Rep-and two non-coding region-LIR and SIR-
were compared and a phylogenetic tree was constructed.
Authors:A. Turkin, V. Drebushchak, Yulia Kovalevskaya, and I. Paukov
Heat capacity of stoichiometric homogeneous spinel MgFe2O4 was measured from 5 to 305 K and thermodynamic functions were derived for temperatures up to 725 K using our previous high-temperature
experimental data for the same sample.
Anomaly in Cp was found at very low temperatures. Experimental data below 20 K contain large (up to 25% near 5 K) error arising from the
difference in the thermal history between the experimental series.
Magnetic contribution to the low-temperature heat capacity was tested, and the linear function was found to fit experimental
data better than the three-halves power derived from the spin-wave theory.
Summary A double endothermic peak appears in the DSC curve of a PTHF oligomer. In order to investigate this phenomenon, a two-component blend of PTHF was prepared with a number average molecular mass of M=1400, and the double endothermic phenomena were investigated by TM-DSC. The larger the amount of the long chain component in the PTHF blend, the smaller the difference between the Cp-T curve and the normal DSC curve. The amounts of endothermic energy ?Hendo,1, ?Hendo,2 and exothermic energy ?Hexo,1, ?Hexo,2 in each peak at infinite modulation frequency were estimated.
The temperature dependencies of the molar heat capacities of ZnTeO3, Zn2Te3O8, CdTeO3 and CdTe2O5 are determined. The experimental data are statistically processed using the least squares method to determine the parameters in the equations for the corresponding compounds: Cp,m=a+b(T/K)-c(T/K)-2. These equations and the standard molar entropies are used to determine ΔT0S0m, ΔTTH0m and (Φ0m+ΔT,0H0m/T) for T'=298.15 K.
Authors:V. Drebushchak, Yulia Kovalevskaya, I. Paukov, and Elena Boldyreva
Heat capacity of tripeptide diglycylglycine was measured in a temperature range from 6.5 to 304 K. The results were compared
with those for glycine and glycylglycine. Peptide bonding was found not to change CP(T) virtually above 70 K, where heat capacity does not obey the Debye model.
Comparison with literature data allows one to expect a significant difference in the heat capacity for enantiomorph and racemic
species of valine and leucine, like it was found recently for D-and DL-serine.
Two mesoporous silicas (HMS) with high surface area and a pore diameter size of 2 nm were synthesized by a sol–gel method.
Platinum catalysts were prepared with a 1 wt% metal content. A commercial silica supported catalyst was used for comparison.
The catalysts were characterized by H2-TPR, TEM and 29Si-CP-MAS-NMR. The catalytic activity was measured by the hydrodechlorination of 1,2-dichloroethane. The enhanced activity
of the mesoporous catalysts was related to the platinum particle size.
The theoretical approaches to the biogeochemical examination of continental water systems in Yugoslavia are discussed.
These water systems have been characterized by the parameters (partial and integral contents of elements CX) of the components of these systems, vir. living and non-living matter (non-living matter: materials dissolved in water CW, suspended and bed materials Csm and Cbm, soil in the rivers basin Cs; living matter Cvivo: plankton Cp, algae Cal, benthos Cb, shells and crustacea Csc, fish Cf). The values of the integral contents of Cr, Sb, Sc, Fe, Co, La and Na in the components of the rivers Danube, Sava, V. Morava,
Tisa and Karas are presented and discussed.