Biography:

In the past T. Kobayashi has collaborated on articles with K. Onda and O. Kajimoto. One of their most recent publications is Gas absorption accompanied by complex chemical reactions — III Parallel chemical reactions. Which was published in journal Chemical Engineering Science.

More information about T. Kobayashi research including statistics on their citations can be found on their Copernicus Academic profile page.

T. Kobayashi's Articles: (173)

Gas absorption accompanied by complex chemical reactions — III Parallel chemical reactions

AbstractGas absorption accompanied by the parallel chemical reactions is discussed from the view-point of the film theory. The approximate solutions for the ratio Φ are derived by the same method described in our previous papers and compared with the analytical or numerical solutions for several cases. The difference of the ratio Φ between the approximate and the exact solutions is only a few per cent.

Gas absorption accompanied by complex chemical reactions - II Consecutive chemical reactions

AbstractBased upon the film theory, the approximate solutions for gas absorption accompanied by two consecutive chemical reactions of the forms γAA+γBB→γCC+ Product,γA′A′+γCC→γCC→γBB and γAA+γBB→γCC,γAA+γ′CC Product, are derived and compared with the numerical solutions. For the case of equal diffusivities, the approximate and numerical solutions agree with each other within a few per cent.

Gas absorption accompanied by complex chemical reactions-IV: Unsteady state

AbstractFor gas absorption accompanied by (m,n)-(p,q)-th order reversible, consecutive and parallel chemical reactions, the approximate solutions based on the penetration and surface renewal theories are derived under the condition of equal diffusivities, and compared with the approximate solution based on the film theory to manifest the generalized solution being suitable for three theories. For the case of reversible chemical reaction, the approximate solution based on the penetration theory is compared with the numerical solution to examine the accuracy of Hikita and Asai's approximation in the unsteady state. It is found that the division of the approximate solution from the numerical solution is only a few per cent.

4-(N,N-Dimethylamino)benzonitrile solvated by a polar molecule: Structural demand for charge-transfer state formation

AbstractVan der Waals complexes consisting of 4-(N,N-dimethylamino)benzonitrile and a polar molecule such as H2O and CF3H were produced in a free jet. The laser-induced fluorescence spectra of their 0-0 bands showed blue-shifts in contrast to the van der Waals complexes with rare-gas atoms. Their emission spectra did not contain any charge-transfer component which is known to be easily observed in a polar solvent. These facts are interpreted in terms of the structure of the van der Waals complexes.

Picosecond dynamics of the twisted intramolecular charge-transfer state formation of 4- (N,N-dimethylamino) benzonitrile (DMABN) in supercritical fluid solvent

AbstractThe rate of formation of the intramolecular charge-transfer state of 4- (N,N-dimethylamino) benzonitrile (DMABN) has been determined in supercritical CF3H using a fast single-photon counting technique. The rate constant increases rapidly with increasing CF3H density, indicating the importance of the polar environment which is brought about by the CF3H molecules clustering around DMABN.

Quantum beats in systems with nearly equal photon energies of stimulated emission and photoinduced absorption

AbstractQuantum beats in optical nutation are calculated in a system, such as a polydiacetylene, in which photon energies of stimulated emission and photoinduced absorption are nearly equal. It is pointed out that the transversal relaxation time constant and the dipole moment of the transition between self-trapped excitons and m 1Ag excitons, observed as photoinduced absorption, can be determined by a measurement of quantum beats in the optical nutation.

Identification and separation of spectral change due to temperature increase in nanosecond transient absorption spectra of polydiacetylene thin films

AbstractTime dependence of a photoinduced absorbance change in a thin film of polydiacetylene PDA-3BCMU (poly-4,6-decadiyne-1, 10-diol-bis(n-butoxycarbonyl-methylurethane)) was separated from the effect of increasing sample temperature by a newly designed method. The resultant nonthermal contribution relaxes via a geminate recombination process, probably due to polarons.

Laser photolysis study on the photosubstitution in dimanganese and dirhenium decacarbonyls

AbstractTwo photoprimary processes, (1) the metalmetal bond cleavage to give M(CO)5 and (2) CO dissociation without metalmetal bond cleavage to give coordinately unsaturated dimetallic species, M2(CO)g, are verified by the laser flash photolysis of M2(CO)10 (MMn, Re). The nature of the new species is discussed from the excitation wavelength effect and the quenching experiments with alkyl cyanides for MMn, and CO and CCl4 for MMn, Re. Photoreaction of Mn2(CO)g is investigated by nanosecond time-resolved double-flash method.

Analysis of impact properties of A533 steel for nuclear reactor pressure vessel by instrumented Charpy test

AbstractInstrumented Charpy impact test can become more useful by connecting the digital memory and microcomputer, where yield load (Py), maximum load (Pm), premaximum load energy (Ei) and post-maximum load one (Ep) are automatically and rapidly analyzed. In such analysis, cyclic oscillations in a load signal are corrected and smoothened by using a method of moving averages (the nonrecursive low pass digital filter). Dynamic J1c value (J1d) of A533 steel can be measured in a fatigue precracked type Charpy specimen, provided that a true deflection of specimen and a true crack initiation point in the load-deflection curve are known. For this purpose, elastic compliance values of the testing machine and the specimen are measured dynamically by the elastic low blow test to correct the apparent deflection. Crack initiation point, on the other hand, is detected by the plastic low blow test. It is shown that the crack initiation in the fatigue pre-cracked specimen of this material occurs prior to the maximum load, and that the relation between crack initiation energy (EΔα) and pre-maximum load energy (Ei) is EΔαEi − 0.8.

Distribution and characterization of immunoreactive growth hormone (GH) in the pituitary of the frog Rana ridibunda using an antiserum against purified bullfrog GH

AbstractThe presence of growth hormone (GH) in the pituitary of the frog Rana ridibunda was investigated using an antiserum raised against purified bullfrog GH. The immunofluorescence technique revealed that GH-containing cells are exclusively located in the dorsal area of the distal lobe of the pituitary. The relative abundance of these GH-positive cells, which correspond to acidophilic type 2 cells, was 1ζ ± 1% of the total population of endocrine cells of the pars distalis. Frontal sections of the distal lobe indicated that GH-producing cells are distributed in an arc of a circle occupying all of the dorsal part of the lobe. At the electron microscopic level, GH-immunoreactive material was sequestered in large polymorphic granules (200–700 nm). GH was quantified in R. ridibunda pituitary extracts using a radioimmunoassay for bullfrog GH. The displacement curves obtained with serial dilutions of pars distalis extracts were not strictly parallel to the standard curve made with purified bullfrog GH. In contrast, Western blot analysis revealed that GH from R. ridibunda had a molecular weight (22 kDa) similar to that of bullfrog GH. In the pars distalis, the apparent amount of GH was 0.61 ± 0.14 μg per lobe, corresponding to 0.92 ± 0.17% of total proteins in the extracts. In contrast, frog neurointermediate lobe or hypothalamus did not contain significant concentrations of immunoreactive GH (less than 0.006% of total proteins in the extracts). Taken together, these results validate the use of an antiserum to bullfrog GH to investigate the regulation of GH secretion in R. ridibunda.

Epitaxial growth of an organic semiconductor from the vapor phase — TCNQ on potassium chloride

AbstractEpitaxial films of 7,7′,8,8′-tetracyanoquinodimethane (TCNQ), a strong electron acceptor were formed on a KCl cleavage face by condensation from the vapor phase. Electron optical studies revealed that the films assume two different configurations depending upon the condition of the surface treatment, although they are both composed of small crystallites of ac-orientation and take multiple positioning with certain regularities characteristic of the individual types. It was deduced from specific features of the mutual orientation of the deposit and substrate crystals that epitaxial nucleation is governed primarily by the oriented adsorption of TCNQ molecules on the ionic lattice of KCl and secondarily by the sporadic matching of lattice points at the interface of both crystals.

Epitaxial growth of a new polymorph of Cu-Phthalocyanine on graphite

AbstractThe epitiaxial growth of Cu-phthalocyanine vacuum deposited on cleaved surfaces of graphite was studied by means of electron microscopy and selected area electron diffraction. The analysis of titled diffraction patterns revealed that the epitaxial crystallite of Cu-phthalocyanine assumes a new polymorph with an orthorhombic unit cell whose dimensions are a = 14.9, b = 12.2 and c = 13.7 Å. Epitaxial crystallites of Cu-phthalocyanine were found to assume a high-index plane such as (25̄3), at the interface. The appearance of the crystallites and the formation of the new polymorph were ascribed to the strong π-electronic interaction at the surface. This interaction is thought to control the oriented absorption of the molecule upon the surface lattice of the graphite substrate, resulting in formation of epitaxial nuclei of the new polymorph.

Epitaxial relationships during the formation of three-dimensional snow dendrites

AbstractInvestigations of natural polycrystalline snow crystals, especially of plane assemblage of crystals of spatial type, have disclosed a predominant misorientation of 70° in the c-axes between the main branch and the secondary branch. As the result of application of the Coincidence Site Lattice (CSL) theory to the interpretation of this misorientation, {3032}/{0001}, {3034}/{3034} and {3038}/{3038} are proposed as probable boundaries having a good atomic fit and low energies. It follows from this proposition that, once an m-c-c-m type of stacking fault is induced, CSL boundaries will extend beyond the junction, giving the 70° misorientation between a deposit and a substrate.

The role of the cubic structure in freezing of a supercooled water droplet on an ice substrate

AbstractThe possibility of the formation of a metastable cubic (diamond) structure and its role in freezing of a supercooled water droplet on an ice substrate are discussed in terms of two-dimensional nucleation. The mode of stacking sequence of new layers formed by two-dimensional nucleation is divided into single and multi-nucleation according to the degree of supercooling and to the size of the supercooled droplet. In the case of single nucleation a frozen droplet develops into a complete hexagonal single crystal or an optically single crystal (containing discontinuous stacking faults). In the case of multi-nucleation attention is paid to the size effect and the stacking direction of the nucleus to calculate the waiting time in the nucleation. Then the frozen droplets are crystallographically divided into three categories: completely single crystals, optically single crystals (containing a small cubic structure, i.e. stacking faults) and polycrystals with a misorientation of 70.53° between the c-axes.

High density excitation effects on fluorescence from the crystals of aromatic hydrocarbons and charge-transfer complexes

AbstractHigh density excitation effects on fluorescence were studied for the crystals of fluoranthene, chrysene, benzo[g, h, i]perylene, pyrene and pyrene-d10 and also for the crystal of 1,2,4,5-tetracyanobenzene (TCNB)-hexamethylbenzene (HMB) complex. Relative fluorescence intensity in the shorter wavelength region decreased with increasing excitation density (for chrysene, fluoranthene, and benzo[g, h, i]perylene), and the vibrational structure became diffuse at high density excitation (for fluoranthene and chrysene). The rate constants of the bimolecular quenching and exciton migration were obtained by analysis of the fluorescence decay curves at high density excitation for chrysene, pyrene, pyrene-d10, and TCNB-HMB. The exciton hopping rates at 295 K were 2.4 × 1010 s−1 in chrysene and 7.9 × 108s−1 in TCNB-HMB. The differences in the rate between chrysene and fluoranthene (2.2 × 109s−1) and between TCNB-HMB and TCNB-durene (4.2 × 109s−1) are discussed in terms of the coupling intensity between two neighboring oscillators accompanying the transition between ground and the lowest excited singlet state. The difference in the rate and activation energy of exciton migration between pyrene and pyrene-d10 corresponded to a quasilocalized exciton model.

Sleep deprivation: Changes of monoamines and acetylcholine in rat brain

AbstractTotal sleep deprivation in rats produced by maintenance on a 24-hour avoidance schedule produced slightly increased acetylcholine in the telencephalon and markedly decreased 5-hydroxytryptamine and norepinephrine in the diencephalon. After a short period of sleep following the 24-hour sleep deprivation, the decreased 5-hydroxytryptamine and norepinephrine levels rapidly equalled or surpassed the control levels.When the paradoxical sleep was deprived for 96 hours, the acetylcholine content decreased in the telencephalon and the norepinephrine level was significantly lowered in the brain stem. There was, however, no significant change in the level of 5-hydroxytryptamine after 96 hours of paradoxical sleep deprivation.

New catalysts for the high pressure synthesis of cubic BN

AbstractThe catalytic effect of water on the high pressure synthesis of cubic BN from hexagonal BN is studied in further detail. An amorphous substance is found to coexist with cubic BN thus prepared and is tentatively identified as anhydrous ammonium borate. The idea that a melt of ammonium borate which is formed by the reaction of hexagonal BN and water at high pressures and temperatures might act as a flux for the conversion from hexagonal BN to cubic BN, leads to the discovery of new catalysts, Urea, Ammonium borate, Ammonium nitrate, etc. It is also found that cubic BN can be synthesized from Boron and Urea or Ammonium nitrate under the same pressures and temperatures. The results open more efficient ways of synthesizing cubic BN.

Compact N2 laser oscillator- amplifier system for laser microbeam application

AbstractA new design of an oscillator-amplifier system in the TE N2 laser is presented which uses only a single laser tube. Two apertures, each of 1 mm square, are placed on both sides of the optical cavity to limit transverse modes. The laser light from the optical cavity is folded and sent back into the laser tube after expansion. Thus, laser light which is approximately diffraction limited is obtained with an energy of 50 μ J. It is confirmed that this laser provides a microbeam spot with a diameter of less than 1 μm.

A compact TEA CO2 laser for field-based spectrochemical analysis of geological samples

AbstractA compact capacitor-transfer TEA CO2 laser of 180 mJ output energy and 50 ns pulse duration in half width was designed and constructed for field use. This laser is suitable for laser microprobe spectrochemical analysis on geological and mining samples. Experiments show that the use of helium as a surrounding gas suppresses the continuous emission spectrum of the plasma, thus increasing the S/N ratio. Using glass as standard samples, the minimum detectable concentrations are estimated with Zn neutral line and F ionic line to be 60 ppm and 500 ppm, respectively.

Plasma levels of atrial natriuretic peptide under acute hypoxia in normal subjects

AbstractTo investigate whether the acute hypoxia can be a stimulus for atrial natriuretic peptide (ANP) secretion, plasma levels of ANP were determined under three different hypoxic conditions in six normal subjects. During 15% O2 breathing for 10 min, no significant change in plasma ANP level was observed. Severe hypoxia induced by 10% O2 breathing increased the mean pulmonary arterial pressure (Ppa) by 11.6 mm Hg within 10 min (P < 0.01), accompanying a slight but significant rise in plasma ANP level of pulmonary artery (PA) from 24.3 ± 5.3 to 28.2 ± 4.6 pg/ml (P < 0.05). There was a tendency for the ANP level of PA to rise under hypoxic hypobaria at 515 Torr for 10 min, followed by a decrease of that level during 100% O2 breathing under hypobaric condition. These changes, however, still remained in the normal range. No significant changes were observed both in right atrial pressure and in pulmonary capillary wedge pressure under any of the three hypoxic conditions. From these results we conclude that ANP can be released in response to the elevation of Ppa caused by acute hypoxia in normal subjects, but the changes in plasma ANP level may be too small to play a significant physiological role in hemodynamic responses to acute hypoxia.

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