Mechanism of diene polymerization
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Local Frederiks transitions near a solid/nematic interface
We consider a solid/nematic interface where long range van der Waals torques favor homeotropic alignment, while a direct steric effect tends to induce a planar alignment. Depending on the relative strength of the two contributions, one may find two transitions : planar ↔ conical and conical ↔ homeotropic. This is remi…
Pyrophosphates of Tetravalent Elements and a Mössbauer Study of SnP2O7
Cubic M 4+ P 2 O 7 pyrophosphates of Ti, Zr, Hf, Sn, and Pb have been examined by X-ray powder diffractometry and by infrared, Raman, and Mössbauer 119 Sn spectroscopy. The tin compound appeared to be of Chaunac's type I (with P 2 O 7 groups oriented at random) and could be converted to type II (with ordered P 2 O 7 g…
Dose rate effects in nickel-ion-irradiated nickel
Nickel samples have been irradiated at two different dose rates with the same dose of 2.8-MeV 58Ni+ to a peak damage level of 13 dpa. The peak damage dose rates were ∼7 × 10−2 dpa sec−1 (HDR) and ∼7 × 10−4 dpa sec−1 (LDR). An upward shift of ∼75°C in the low-temperature limit for swelling has been observed for this in…
Some Preliminary Considerations of A Molten-Salt Extraction Process to Remove Tritium from Liquid Lithium Fusion Reactor Blankets
A method is described for removing tritium from liquid lithium fusion reactor blankets by extraction with molten salt. Results of distribution coefficient measurements made with lithium-lithium halide mixtures have demonstrated that tritium is preferentially distributed in the salt phase by a factor >1.0 on a volumetr…
Electroinitiated cationic polymerization of styrene by direct electron transfer
Abstract We have studied by cyclic voltammetry the mechanisms of electron transfer and peak potentials of eleven alkenes, propylene oxide, propylene sulfide, and carbon disulfide. We have also studied the cationic polymerization of styrene in acetonitrile solution initiated by controlled potential electrolysis at the…
Thermal expansion of mixed−alkali germanate glasses
Thermal expansion measurements were made for several series of Na2O⋅K2O⋅GeO2 glasses, for one series of Na2O⋅Rb2O⋅GeO2 glasses, and for one series of Na2O⋅Cs2O⋅GeO2 glasses. Negative deviations from additivity were observed in the critical and deformation temperatures in every case, with the deviations increasing with…
Heats of Mixing in Liquid Copper or Gold Binary Alloys
Using the single adiabatic wall calorimeter, heats of mixing in the binary liquid alloys of copper and silver, gold, aluminum, gallium, indium, germanium or tin, and also in the binary alloys of gold and silver, aluminum, gallium, indium, germanium or tin were determined at 1100°C.The experimental method and procedure…
Crystallization and Crystal Data of Monellin
Crystals of monellin, a sweet protein from Dioscoreophyllum cumminsii, were grown by vapor diffusion of 20% ethanol into buffered protein solution. The crystals are orthorhombic, belonging to space group P2(1)2(1)2, with a = 54.4 A, b = 113.0 A, c = 40.8 A, and V = 250,300 A(3). The asymmetric unit contains two comple…
The nuclear magnetic resonance spectra of porphyrins. Part X. Carbon-13 nuclear magnetic resonance spectra of some meso-tetraarylporphyrins and their metal chelates
The 13C n.m.r. spectra of meso-tetraphenylporphyrin (TPP), the zinc(II), cadmium(II), bis[mercury(II) acetate], and various thallium(III) derivatives, and some related analogues are reported and assigned. In meso-tetra-(o-tolyl)-porphyrin and meso-tetra-(1-naphthyl)porphyrin only one species was observed. The introduc…
Carrier Mobilities in Insulating Polymers Measured by Time of Flight Method
Carrier mobilities of several insulating polymers such as PET, PS were studied by the time of flight method using pulsed electron beam bombardment. For example, the mobilities obtained in an electric field of 1∼2 MV/cm were 2×10 -5 cm 2 /V·sec for the electron and 1×10 -4 cm 2 /V·sec for the hole at 27 °C in PET with…
Catalyst Deactivation Due to Pore-Plugging by Reaction Products
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCatalyst Deactivation Due to Pore-Plugging by Reaction ProductsEsmond NewsonCite this: Ind. Eng. Chem. Process Des. Dev. 1975, 14, 1, 27–33Publication Date (Print):January 1, 1975Publication History Published online1 May 2002Published inissue 1 January 1975https://pubs.acs.o…
Relaxation and final-state structure in XPS of atoms, molecules, and metals
Photoemission from a many-electron system is a many-electron process, even though the transition operator may affect only one electron directly. Relaxation and “shake-up” structure are related by a sum rule: when one is present, the other must also be present. Shake-up structure is shown to be accurately predictable i…
Shear flow induced polarization in ferroelectric smectics C
The existence of ferroelectricity in the chiral smectic C phase has been established from polarization measurements in the presence of an electric field [1]. In this article we study the case where the polarization is created by applying a shear velocity parallel to the smectic planes : The helicoidal structure is dis…
Structure and reactivity of ruthenium(II) porphyrin complexes. Photochemical ligand ejection and formation of ruthenium porphyrin dimers
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTStructure and reactivity of ruthenium(II) porphyrin complexes. Photochemical ligand ejection and formation of ruthenium porphyrin dimersFrederick R. Hopf, Terrence P. O'Brien, W. Robert Scheidt, and David G. WhittenCite this: J. Am. Chem. Soc. 1975, 97, 2, 277–281Publication…
Ferroelectric properties and fatiguing effects of modified PbTiO3 ceramics
The ferroelectric properties of fine-grained PbTiO3 ceramics modified by small amounts of La and Mn have been investigated using both quasi-static (∼ 0.05 Hz) and more dynamic (0.5-50 Hz) electric driving fields.Information about the domain reorientation processes were obtained from lateral switching strain and hyster…
Analysis of the optical spectrum of Tm 3 + in LiY F 4
Absorption and fluorescence spectra of ${\mathrm{Tm}}^{3+}$ in single-crystal LiY${\mathrm{F}}_{4}$ were recorded at temperatures between 5 and 77 K. The energy levels for the ground configuration were established from these data with the aid of theoretical calculations. Parameters were obtained that gave a least-squa…
High-field Mössbauer study of manganese-zinc ferrites
The disordered ferrite system, ${\mathrm{Mn}}_{1\ensuremath{-}x}{\mathrm{Zn}}_{x}{\mathrm{Fe}}_{2}{\mathrm{O}}_{4}$ for $0\ensuremath{\le}x\ensuremath{\le}0.95$ has been studied by the M\"ossbauer-effect technique at 4.2 K in applied magnetic fields of 50 and 90 kOe. In these fields a ferrimagnetic structure is implie…
Thermal Transition Behavior of Polyurethanes Based on Toluene Diisocyanate
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThermal Transition Behavior of Polyurethanes Based on Toluene DiisocyanateN. S. Schneider, C. S. Paik Sung, R. W. Matton, and J. L. IllingerCite this: Macromolecules 1975, 8, 1, 62–67Publication Date (Print):January 1, 1975Publication History Published online1 May 2002Publis…
D-Glucose Dehydrogenase from Bacillus megaterium M 1286: Purification, Properties and Structure
1) Glucose dehydrogenase from Bacillus megaterium has been purified to a specific activity of 550 U per mg protein. The homogeneity of the purified enzyme was demonstrated by gel electrophoresis and isoelectric focusing. 2) The amino acid composition has been determined. 3) The molecular weight of the native enzyme wa…