Application of pressure sensitive paint measurement to a low-solidity cascade diffuser of a transonic centrifugal compressor

A pressure sensitive paint (PSP) measurement has been known as a pressure field measurement technique based on the oxygen quenching phenomenon of luminescence of specific luminophores. A PSP measurement was applied for pressure field measurement in a low-solidity circular cascade diffuser of a single-stage transonic centrifugal compressor with 5 in pressure ratio for HFC134a gas. The oxygen concentration was about 500 ppm. Ru (bath-phen) was adsorbed on a silica-gel thinlayer chromatography sheet, and the sheet was pasted onto the side-wall between the cascade vanes. A drastic change in luminescent intensity was recognized during a surge condition. Also the pressure variations based on luminescent intensity agreed well with the pressure fluctuations measured using a semiconductor pressure sensor with high-frequency-response. It was shown that a PSP measurement worked well to investigate the unsteady pressure fields in a circular cascade diffuser of a transonic centrifugal compressor. Moreover, the time response of PSP becomes clear as a problem to be overcome for the present.     

Effects of quaternary ammonium bases on valence-saturated but coordination-unsaturated chelates: Part IV. Extraction of some divalent metal 8-hydroxyquinolinates

The effect of zephiramine on the chelate formation and extraction of some divalent metals with oxine is reported. In the presence of zephiramine, the non-extractable 1:2 zinc— and cadmium—oxine chelates as well as the extractable 1:2 nickel— and manganese—oxine chelates become highly coordinated ternary complexes, M(Q)₃ (zeph), which are easily extracted into 1,2-dichloroethane. Copper is easily extracted into 1,2-dichloroethane as Cu(Q)₂, which is not affected by zephiramine.     

Resonance Raman scattering with a forbidden but vibronically allowed electronic transition: Excitation profiles of combinations and overtones of copper tetraphenylporphyrin in the Q-band resonance

Resonance Raman scattering with the Q band of CuTPP shows a peculiar intensity pattern; bands due to combinations and overtones are strong, whereas the corresponding fundamentals are very weak. By a quantitative analysis of excitation profiles, this phenomenon has been fully accounted for on the basis of the vibronic theory of Raman intensities. Vibronic coupling parameters between the Q and B states of CuTPP have been obtained.     

The role of carbon dioxide in chemoselective hydrogenation of halonitroaromatics over supported noble metal catalysts in supercritical carbon dioxide

Chemoselective hydrogenation of halogenated nitrobenzenes over Pt/C catalysts proceeds effectively in supercritical carbon dioxide (scCO2) to produce halogenated anilines with excellent selectivity; the rate of the hydrogenation of nitro groups is markedly enhanced in scCO2 compared to the neat reaction, and the dehalogenation reaction is significantly suppressed.     

Synthesis of porphyrin-introduced silica gels by sol-gel process

Using a hydroxyl group appended free base porphyrin derivative (HP), porphyrin-introduced silica gels were synthesized by a sol-gel process. The HP content in the materials linearly increased with increasing the HP concentration. Meanwhile, free base tetraphenylporphyrin (TPP) with no hydroxyl groups were almost not incorporated into the silica gels. These facts suggested that the interaction between hydroxyl groups of the HP molecules and silica network is considerably strong. The UV-vis characters of HP-introduced materials were almost the same as pure HP molecules. The Beer's plot indicated that the HP molecules in the materials are dispersed.     

Frequency response of the glucose sensor based on immobilized glucose oxidase membrane

Frequency response of the glucose sensor based on the immobilized glucose oxidase membrane was investigated experimentally by giving the sinusoidal change of glucose concentration to the glucose sensor and observing its output signal. Observed values of gains and phase lags of the frequency response of the glucose sensor followed the frequency response model of the first-order with dead time; The time constant and also the dead time were estimated and found to decrease as the amount of enzyme immobilized in the membrane increased and the thickness of the membrane decreased.

     

Three bits eight states photochromic recording and nondestructive readout by using IR light

A photochromic polymer film containing three different diarylethene derivatives, that is, 1,2-bis(3,5-dimethyl-2-thienyl)perfluorocyclopentene (1), 1,2-bis(2,5-dimethyl-3-thienyl)perfluorocyclopentene (2), and 1,2-bis(2-methyl-5-phenyl-3-thienyl)perfluorocyclopentene (3) was prepared. Upon UV irradiation, the three derivatives changed to their closed-ring isomers having different colors, yellow, red, and blue. They showed different spectra not only in UV/Vis region but also in the IR spectral region. Upon irradiation with visible light of appropriate wavelengths, each closed-ring isomer was selectively bleached, and three bits eight states recording was performed. The eight states could be read out nondestructively by using IR light of appropriate wavenumbers.     

CASSCF and CASPT2 studies on the structures, transition energies, and dipole moments of ground and excited states for azulene

The electronic structure of azulene molecule has been studied. We have obtained the optimized structures of ground and singlet excited states by using the complete active space self-consistent-field (CASSCF) method, and calculated vertical and 0-0 transition energies between the ground and excited states with second-order M?ller-Plesset perturbation theory (CASPT2). The CASPT2 calculations indicate that the bond-equalized C(2v) structure is more stable than the bond-alternating C(s) structure in the ground state. For a physical understanding of electronic structure change from C(2v) to C(s), we have performed the CASSCF calculations of Duschinsky matrix describing mixing of the b(2) vibrational mode between the ground (1A(1)) and the first excited (1B(2)) states based on the Kekule-crossing model. The CASPT2 0-0 transition energies are in fairly good agreement with experimental results within 0.1-0.3 eV. The CASSCF oscillator strengths between the ground and excited states are calculated and compared with experimental data. Furthermore, we have calculated the CASPT2 dipole moments of ground and excited states, which show good agreement with experimental values.     

Concentrated reverse micelles in a random graft block copolymer system: structure and in-situ synthesis of silver nanoparticles

The structure and rheological properties of a poly(dimethylsiloxane)-graft-poly(oxyethylene) copolymer at high concentrations in block-selective solvents were studied by small-angle X-ray scattering (SAXS) and rheometry. Analysis of SAXS data indicates that quasispherical, reverse micellar aggregates (with no ordered packing) are present in concentrated solutions of the copolymer in nonpolar solvents, and that upon addition of water, the size of such aggregates increases due to the solubilization inside the micellar cores. The viscosity of concentrated polymer solutions increases exponentially as water is added, and finally, viscoelastic, gel-like behavior is found in the vicinity of the phase separation limit. It was found that small silver nanoparticles with an average diameter of ≈3 nm can be synthesized inside the copolymer aggregates without the need of a reducing agent; namely, particles embedded in a viscoelastic matrix are obtained. The synthesis seems to follow first-order kinetics. Electronic supplementary material Supplementary material is available in the online version of this article at and is accessible for authorized users.     

Pharmacokinetics of caffeine and its metabolites in horses after intravenous, intramuscular or oral administration.

The pharmacokinetics of caffeine (CAF) and its metabolites, dimethylxanthines, were examined in horses administered 2.5 mg/kg of CAF intravenously (i.v.), intramusculary (i.m.), or orally (p.o.). The plasma samples were extracted by Extrelut and the concentrations of CAF and metabolites were determined by high performance liquid chromatography (HPLC) with a short column. The pharmacokinetics of CAF after bolus i.v. injection were described by the assumption of a two-compartment model, and those of CAF after i.m. or p.o. administration were done by the assumption of a one-compartment model. The biologic half lives of CAF were 15.5, 18.6, and 16.4 h after administering i.v., i.m. and p.o., respectively. The extent of the bioavailability of the p.o. administration was determined as 1.04 times the dose. The differences in pharmacokinetic parameters were not statistically significant among administration routes. A straight correlation existed between the logarithms of body weights of different species of animals and those of their biologic half lives of CAF. Therefore, the biologic half life of CAF in an animal might be predictable as a function of its body weight.