Effect of the langmuir-type ion adsorption on the membrane potential of a non-charged membrane

Membrane potential is determined by the combination of the properties of ions and of the membrane. There is, therefore, a possibility that the properties of ions can be reflected on the membrane potential more effectively by artificially modifying the membrane properties. In this paper, the membrane is assumed to have no charge but to adsorb cations or anions selectively, and the effect of Langmuir-type adsorption of ions on the membrane potential is investigated theoretically. The variation of the amount of adsorbed ions affects not only the surface potential but also the diffusion potential within the membrane. The membrane potential shows a minimum or a maximum with the variation of the ion concentration in the bulk solution. This phenomenon results from the variation of the amount of ions adsorbed onto the membrane surfaces. Therefore, information on both the adsorption coefficient of a given ion and the amount of saturation of absorption of the ion is obtained from an analysis of the membrane potential. The theory is applied to the analysis of the affinity membrane potential, which can be used for the determination of blood type, and it is shown that the theory is in good agreement with experimental data.     

Characterization of Pyrene Photoproducts in Chloroform by Gas-Chromatography and Gas-Chromatography Mass-Spectrometry

Photoproducts resulting from illumination of a pyrene-chloroform solution using several light sources (sunlight, lamp, a pulsed laser) were analyzed by using gas chromatography (GC) and GC-mass spectrometry. The main photoproducts in chloroform were chloropyrene and pyrenecarboxaldehydes, and their relative yields depended on differences in illumination conditions. Chloropyrene was formed under all types of light illumination, while ultraviolet lights was required for the formation of pyrenecarboxaldehydes. Several reaction mechanisms are proposed to account for the formation of chloropyrene and pyrenecarboxaldehydes.     

Hydrolysis of 4-cyano-1-ethoxypyrimido[1,6-a]benzimidazole: Formation of a ynaminonitrile and benzimidazolidines

The title compound 4 was hydrolyzed to a new type of ynaminonitrile 5 and benzimidazolidines 7 and 9 under acidic or basic conditions. Reaction mechanisms were proposed.     

Rotational and vibrational states of excitonic molecules in CuBr studied by the two-photon-resonant Raman scattering

Excited states of excitonic molecules are found in the study of the two-photon-resonant Raman scattering. These states consist of four levels and have binding energies of 1.0–1.8 meV, which are very small compared with those of the ground states. They are considered to be the rotational and vibrational states of excitonic molecules.     

Brillouin scattering investigation of paraelectric KH2PO4 under applied uniaxial stress

The Brillouin scattering spectra of KH₂PO₄ under an applied uniaxial stress have been studied in the neighborhood of the ferroelectric transition. Dependence of shear acoustic phonon on the uniaxial stress is similar to dependence on electric field. The acoustic phonon is overdamped near T_c, but become underdamped under the applied shear stress. In the case of ΔT(= T — T_c) < ～ 0.05 K, application of stress caused a transition not to have any soft acoustic phonon.     

Extraction of alkali metal picrates by crown ethers having uncharged coordinating flexible side-chains

Crown ethers were synthesized which have a flexible, neutral side-chain capable of providing the crown ether-bound metal with an additional binding site from the axial direction. Liquid—liquid extraction of alkali metal picrates with these crown ethers was studied; the extraction is compared with that of the normal crown ethers as well as those crown ethers with a proton-dissociable side-chain. The neutral side-chain may assist or suppress the ease of metal extraction depending on the site of the ligating atom on the chain. An anionic ligating side-chain interacts favorably with the lighter metals, resulting in a net decrease in the metal extraction selectivity.     

Second-order Raman spectra of CsCl single crystals

The second-order Raman spectra of CsCl single crystals have been measured at room temperature for different Raman polarizations and crystal orientations. With the help of the calculated selection rules for a CsCl-type lattice, observed nineteen peaks and shoulders were assigned by the critical point analysis based on the neutron scattering data. By comparing the observed Raman intensities with the thermally weighted two-phonon density-of-states calculated by using a simple shell model, it has turned out that though the measured spectra are dominantly determined by the two-phonon density-of-states, the effect of the q-dependence of the polarizability cannot entirely be neglected.