The energy levels of the CH and the BH radicals have been calculated by the method of atomic orbitals, taking both s2p2 and sp3 configurations together for the carbon atom and s2p and sp2 for the boron atom and including the overlap integrals and the higher order permutations. The values obtained are in excellent agreement with observations.
The electrolytic reduction of cinnamic acid at a Pb, a Hg, a Hg-Zn or a Pt-Pt cathode in acid solution was studied. It was found that the formation of bimolecular compounds depended on the nature of cathode materials and the condition of the reduction. It was confirmed that the γ-phenylpropyl alcohol could not be produced by the electrolytic reduction of cinnamic acid. It was found that the reduction of cinnamic acid at a Pt-Pt cathode gave cyclohexyl propionic acid. The effect of high pressure of hydrogen in the course of reduction was discussed.
The relation between the kind of ligands and extinction coefficients of the first absorption bands of cobaltic complexes has been discussed. The order of ligands as to the magnitude of the effect which they exert on extinction coefficients of the first bands has been determined empirically, thus NCS^-CrO_4^=SO_3^=NO_2^-CO_3^=C_2O_4^=en OH^-NO_3^-SO_4^=Br^-NH_3Cl^-H_2O. For pentammine cobaltic complexes with the sixth ligands, each of which is coordinated with an oxygen atom, a linear relation has been found to hold between νmax’s and εmax’s of the first bands. For complexes of the type [CoA4X2], the trans-isomer has larger εmax if X has more hyperchromic and trans-pairing effects than A. This investigation was supported by a grant from the Ministry of Education.
In this report, we have presented the results of an experimental investigation carried out of the creep under constant compressive load for concentrated hydrogels of agar-agar. The apparatus which was designed in a previous paper I of this series for the measurement of the compression stress-strain curve was modified to suit the measurement of the creep under constant compressive load. The shape of the creep curves obtained was found to be well fitted by Eq. (1). The influences of temperature, concentration and applied stress on the creep rate in the viscous flow region were investigated separately. One of the interesting facts found was a clear evidence showing that even at zero stress condition there occurred a definite creep process which was closely followed by a straight line within the interval of time of observation employed. It seemed likely that this phenomenon should be associated primarily with the molecular structural feature of the agar-agar gel network which leads the gel to syneresis. It was found for all the data obtained that the relation between λ and S followed Eq.(2) within the limits of experimental error, where λ is the creep rate in the viscous flow region and S is the magnitude of stress applied. This equation involves two parameters λ0 and η, where λ0 stands for the value of λ in the absence of external stress, and η is the Newtonian viscosity corresponding to the region in which a linear viscous flow appears. The influences of various environmental parameters on these two quantities were investigated, obtaining the results as shown in Figures 3, 4 and 5.
As the third report of the series of papers concerning the viscoelastic behavior of concentrated hydrogels of agar-agar, the results of an experimental investigation of the relaxation of stress in an agar-agar gel of a concentration 4 g./100 cc. have been presented, which are summarized as follows: (1) The general type of the relaxation curves obtained may be seen in Figure 2, in which particular attention must be drawn to the behavior that the plotted curves fall across the zero stress base after running certain finite intervals of time. An adequate interpretation of this has been presented in the last section of the text. (2) As was illustrated in the second paper of this series, an agar-agar gel block decreases spontaneously and gradually its volume under the experimental conditions adopted in this series of experiments. Taking into account he spontaneous volume contraction, a system of equations for representing the viscoelastic deformation of an agar-agar gel column subject to compressive load has been presented, in which as a mechanical model of the material two Maxwell relaxation elements connected in parallel have been assumed. (3) All the data of relaxation obtained have been considered in the light of this set of equations. In this way, the numerical results listed in Table 1 have been obtained. (4) The activation energy for relaxation has been calculated for each individual mechanical element by the use of the Arrhenius equation. It has been found that the activation energies so calculated are constant below about 40°C. for both elements, amounting to nearly equal values, the average of which is estimated at about 9 kcal./mole. Above 40°C., for both relaxation elements, deviations from the Arrhenius equation appeared, which are gradually marked with increase in temperature. We have ascribed these deviations to the decrease in the frequency factor in the Arrhenius equation. (5) Finally, the set of equations presented above has been solved for the case of compression creep under constant load, resulting in a creep equation coinciding exactly in form with the empirical creep equation derived in the previous paper II of this series. In addition to this formal agreement of the present theoretical and the previous empirical creep equations, quantitative agreement of them has-been demonstrated by showing that the viscosity values from the previous creep test can be well reproduced by the sum of the individual viscosity values obtained from the present relaxation test.
1. Mechanical behaviors of surfaces of aqueous solutions were studied, and were explained by the three-parameter model with various relaxation times and retardation times. 2. The mode of change of mechanical models with the increase in concentration of the solution were classified into two groups; a change from the dashpot through the Voigt model to the three-parameter model, and a change from the dashpot through the Maxwell model to the three-parameter model. Saponin, crystal violet and sodium stearate belonged to the former, and egg albumin, horse serum albumin, peptone, gum arabic and polyvinyl alcohol, to the latter. It was presumed that this difference was due to the difference in the state of aggregation of their molecule.
The rheological property of the surface of dye solution with a change in pH under constant concentration was studied. Solutions of crystal violet, night blue, congo red and phloxine form the coherent adsorbed layer, while those of scarlet red and methyl orange, do not. The differences between them was considered to be due to the difference in the intensity of the interaction between molecules in the adsorbed layer. The surfaces of solutions of crystal violet, night blue, congo red and phloxine show the transformation of a mechanical model as well as sharp maxima in the value of surface rigidity and surface viscosity coefficient with a change in pH.
The author has assumed in the previous paper that the vibrational term of the partition function of the molecule normal to the surface is equal in both gaseous and liquid films. This assumption was verified at the surface vaporization point in the present paper with the dynamics of material points. The derived relation between frequency and intermolecular distance or potential energy is (12) or (13).
Pitch coke type brushes were found to consist of graphite crystallites having irregular forms and flat surfaces. Sizes of the graphite crystallites were very variable. Well graphitized crystals have relatively flat and smooth surfaces. Less graphitized crystals have rough surfaces. Well-developed flat crystals were split into thin flakes and attached on replica films. Parts of small and badly developed crystallites were seen side by side with the well-developed ones. Carbon black type brushes were found to contain aggregated parts of minute carbon particles and parts of pitch coke origin. The size of the minute particles was approximately the same as that of the original carbon black particles. The minute particles were seen as minute projections or pits on replicas, while they were observed as being linked together to aggregates in directly observed specimens.
1. Wettability of mixed built-up film of stearic acid and barium or calcium stearate decreased with the number of layers, the advancing contact angle tending to the value of about 115°. The difference between θa and θr of built-up film was larger than that of solidified surface. 2. X-film and Y-film of barium or calcium stearate prepared occasionally at almost the same condition showed the same wettability. Increase of barium or calcium content in the film was considered to result in the wettability decrease. 3. Of the three types of metallic ion classified according to the influence on wettability of stearic acid, the following two were studied precisely. (a) Ions of the type III, forming relatively simple stoichiometric compound with stearic acid, the stearates being able to overturn themselves easily in the surface, and the wettability changing with the condition. (Ba, Ca) (b) Ions of the type II, forming a network of a complex structure with stearic acid, which overturn themselves with difficulty in the surface and their wettability does not change with the condition. II—1. Ions, rapidly forming network and render the surface hydrophilic tempolarily. (Al, Cu) II—2. Ions, slowly forming network and rendering the surface hydrophobic (Hg).
The rate constants of the thermal dissociation of carbaminic acid esters in fatty acids were determined. In the case of phenylcarbaminic acid alkylestees, the rates showed the following order. tert-Bu>>isoPr≥Me The relative rates may be considered to denote the ability of —OR groups as proton acceptors and the results of the experiment can be explained by the inductive effect of the substituted alkyl-groups. In the case of alkylcarbaminic acid phenyl-esters, the rates showed the following order. Acetyl>>isoPr>Me The relative rates may be considered to denote the ability of (Remark: Graphics omitted.) groups as proton donors. In acetylcarbaminic acid phenylester, because of the resonance effect of the (Remark: Graphics omitted.) and COOR groups, the intervening nitrogen aquires a positive potential. The phenomenon will make the hydrogen attached to nitrogen have more tendency to transfer, hence the reaction. That isopropylcarbaminic acid phenylester dissociates faster than methyl-carbaminic acid phenylester will be explained by the steric effect of alkyl-groups. The rates of the thermal dissociation of esters depend on the nature of the solvent acids.
(i) Kapfhammer and Eck’s report touching the synthesis of N-p-toluenesulfonyl-L-proline was corrected. (ii) N-p-Toluenesulfonylproline was resulted by the amination and methylamination of [L]-δ-p-toluenesulfonylamino-α- bromovaleric acid. In this case, racemization took place in consequence of amination at 100°, and partial Walden inversions were caused by amination at 0° and methylamination at 0° and 100°.
Various properties of the current-voltage curve of the reduction wave of the hydrogen ion were studied in the system of the dil. HCl in 0.1 N KCl solution. It was found out that the log-plot of the reduction wave is not linear and that the half-wave potential shifts to be more negative with the increase of the limiting current. The temperature coefficient of the half-wave potential was obtained to be about 3 millivolts per degree over the temperature range of 0 to 50°. This value of the temperature coefficient is much larger than the value which is expected when the reduction process of the hydrogen ion proceeds under the condition of the diffusion-controlled type. The Kalousek’s methods were applied to the hydrogen wave in order to test the reversibility of the reduction process and it was shown that this process is one of the irreversible type. These experimental results were satisfactorily explained by assuming the reduction process of the hydrogen ion as follows: First, the hydrogen ion is adsorbed on the surface of the D.M.E., and, next, the adsorbed hydrogen ion is neutralized to the hydrogen atom under the condition of the activation-controlled process. In this case it was assumed that the equilibrium state represented by the Freundlich adsorption isotherm exists between the hydrogen ion in the neighborhood of the electrode surface and the adsorbed hydrogen ion in the adsorbed layer. The value of the free energy of activation of the overall discharge process of the hydrogen ion was calculated.