The subject of this work is ethylene polymerisation using Kaminsky type catalysts: Cp2MR2=methylaluminoxane [M=Zr, W, Nb; R=Cl, CH3]. Active center determination and kinetic studies of the (Cp2WCl2+methylaluminoxane) and Cp2ZrCl2+methylaluminoxane) systems are described, using a quenching method with tritiated methanol. The activity of the polymer was determined by liquid scintillation counting. We have found 0.5% and 87% of active centers, respectively for W and Zr system. The catalytic activity of complexes Cp2WCl2 and Cp2NbCl2 was compared with that of Cp2ZrCl2. The W and Nb complexes are found to be less active than the Zr complex.
The changes in the polypeptide patterns of soluble proteins of wheat flag leaves after treatment with two synthetic cytokinin-like substances 3-CP-2-PU [1-(3-chlorophenyl)-3-(2-pyridyl)urea] and 3-CP-4-MPU [1-(3-chlorophenyl)-3-(4-methyl-2-pyridyl)urea] was studied. Both compounds increased differentially in quantity and composition most individual polypeptides identified compared to the non-treated leaves. While 3-CP-2-PU increased only the polypeptide quantity, 3-CP-4-MPU led to the appearance of new polypeptide with Mw of 51 kDa.
Authors:V.-P. Lehto, M. Rahkola, E. Laine, L. Ylianttila, P. Hyssalo, and K. Jokela
The specific heat capacities (cp) for the brain and muscle equivalent liquids were determined with isothermal heat conduction microcalorimetry (IMC) and differential
scanning calorimetry (DSC). IMC was found to afford an accurate technique to measure cp for solid and liquid samples, when an appropriate reference is employed. The accuracy of obtained cp values was estimated to be better than 0.7% with the equivalent liquids. Intercomparison with a conventional isoperibolic
calorimeter showed an excellent agreement within the estimated uncertainty of the isoperibolic calorimeter (3%). Additionally,
suitability of different kinds of IMC sample vessels was tested, and the standard electrical calibration procedure of IMC
was evaluated through the determination of cp with and without a reference material.
The relationship between heat capacity (Cp) and linear thermal expansion (α) derived from the Lennard–Jones potential is Cp=Aα(U0–E), where U0 is the heat of sublimation at T=0, E is the enthalpy and A is the coefficient. The values of A for different solidified inert gases coincide with one another within the limits of experimental error (±2%).
The relationship is shown to be valid for various substances: solidified rare gases, diamond, halite and copper.
Authors:S. Raveendar, G.A. Lee, K.J. Lee, M.J. Shin, J.R. Lee, S.Y. Lee, G.T. Cho, K.H. Ma, and J.W. Chung
The complete chloroplast (cp) genome sequence of Pearl millet (Pennisetum glaucum [L.] R. Br.), an important grain and forage crop in the family Poaceae, is reported in this study. The complete cp genome sequence of P. glaucum is 138,172 bp in length with 38.6% overall GC content and exhibits a typical quadripartite structure comprising one pair of inverted repeat (IR) regions (22,275 bp) separated by a small single-copy (SSC) region (12,409 bp) and a large single-copy (LSC) region (81,213). The P. glaucum cp genome encodes 110 unique genes, 76 of which are protein-coding genes, 4 ribosomal RNA (rRNA) genes, 30 transfer RNA (tRNA) genes and 18 duplicated genes in the IR region. Nine genes contain one or two introns. Whole genome alignments of cp genome were performed for genome-wide comparison. Locally collinear blocks (LCBs) identified among the cp genomes showed that they were well conserved with respect to gene organization and order. This newly determined cp genome sequence of P. glaucum will provide valuable information for the future breeding programs of valuable cereal crops in the family Poaceae.
Authors:W. Szymanski, S. Truszkowski, G. Smietanska, and M. Kowal
The stable radiolysis products of 1-chlorobutane (1-CB), 1-chlorobutene-2 (1-CB-2), 1-chloropropane (1-CP), 2-chloropropane (2-CP) and 1,3-dichloropropane (1,3-DCP) gamma-irradiated in an oxygen-free atmosphere have been investigated. The pure radiolysis products were separated by preparative gas chromatography and identified by NMR and mass spectroscopy as well as qualitative gas chromatography. The compounds formed were determined by potentiometric analysis and quantitative gas chromatography. From 1-CB we have obtained in the gas phase: HCl, H2, butane; in the liquid phase: 2-chlorobutane, 1,3-dichlorobutane and a mixture of oligomers of the initial compound (dimer and trimer). We have not recorded H2 in 1-CB-2. The main gaseous products of radiolysis of 1-CP are HCl and H2. Radiation yield of isomerization was determined. From 2-CP we have obtained in the gas phase: HCl and H2; in the liquid phase: 2,2-dichloropropane and a mixture of oligomers of the initial compound (dimers and trimers). From 1,3-DCP we have found in the gas phase: HCl and H2; in the liquid phase: 1-CP, 2-CP, 1,2-DCP and oligomers. Preliminary schemes for the formation of stable products are proposed.