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The dielectric permittivity in polymers, fluoroelastomers and ethylene propylene diene monomers was measured as a function of both frequency and temperature. Several relaxation processes were revealed and analyzed through a developed algorithm to analyze the relaxation. The β and the α relaxations were observed and occurred in that order as the temperature was increased. Maxwell-Wagner-Sillars contributions, including conduction, were present at high temperatures and low frequencies. The molecular chains responsible for the relaxation processes were assigned by using molecular modeling with the dipole moment included. The activation energy, Vogel-Fulcher temperature and glass transition temperature were also obtained.

To characterize the dielectric relaxation embedded in polymers, we developed a program algorithm that analyzes the relaxation processes from dielectric permittivity versus frequency data based on governing functions such as the Havriliak-Negami function including the conductivity contribution. With the help of the developed simulation program, we have identified three processes: an α process due to rotational and segmental motions of the C-C bond, an α’ process attributed to the fluctuation of the end-to-end dipole vector of the polymer chain, and the conduction contribution observed at high temperatures and low frequencies. The activation energy and glass transition temperature for the two main relaxations were independently determined from both the imaginary permittivity versus frequency and temperature by assuming Arrhenius dependence and the Vogel-Fulcher-Tamman law. The results obtained by the two methods for α and α’ relaxations were compared with each other and with that obtained by differential scanning calorimetry.

Filler effects on H2 diffusion in nitrile butadiene rubbers (NBRs) blended with carbon black and silica fillers of different concentrations are first investigated by employing a volumetric analysis. Total uptake, solubility, and diffusivity of hydrogen for ten filled-NBR, including neat NBR, are determined in an exposed pressure range of 1.3 MPa~92.6 MPa. Filler dependence on hydrogen uptake and diffusion is distinctly observed in the NBRs blended with high abrasion furnace (HAF) carbon black (CB) fillers compared to NBRs blended with medium thermal furnace (MT) CB and silica filler, which is related to the specific surface area of carbon black and interface structure. The HAF CB filled-NBR follows dual sorption behavior combined with Henry’s law and the Langmuir model, responsible for two contributions of solubility from polymer and filler. However, a single gas sorption behavior coming from the polymer is observed satisfying Henry’s law up to 92.6 MPa for NBR blended with MT CB filled-NBR and silica filled-NBR. Diffusion demonstrates Knudsen and bulk diffusion behavior below and above, respectively, at certain pressures. With increasing pressure, the filler effect on diffusion is reduced, and diffusivity converges to a value. The correlation observed between diffusivity and filler content (or crosslink density) is discussed.

Nondestructive impedance spectroscopy (IS) was developed and demonstrated to detect the effects of hydrogen on nitrile butadiene rubber exposed to hydrogen gas (H2) at high pressures up to 10 MPa. IS was applied to obtain an in situ and real-time quantification of H2 penetration into and its desorption out of rubber under high pressure. The diffusion coefficients of H2 were also obtained from the time evolution of the capacitance, which were compared with those obtained by thermal desorption gas analysis. The in situ measurements of the capacitance and the dissipation factor under various pressures during cyclic stepwise pressurization and decompression demonstrated the diffusion behaviour of H2, the phase of the rubber under high pressure, the transport properties of H2 gas, and the physicochemical interaction between H2 and the rubber. These phenomena were supported by a COMSOL simulation based on the electric current conservation equation and scanning electron microscopy (SEM) observations.

This paper describes a method to determine absolutely the dissipation factor (DF) of a capacitor connected with resistor in series that doesn’t depend on any reference capacitor with a known DF. The method was applied to calibrate the DFs for two capacitor-resistor boxes that had DF ranges of 1 × 10−5 to 1 × 10−2 (C-R connecting box A) and 5 × 10−6 to 5 × 10−3 (C-R connecting box B), together with uncertainty estimation. The principle of the absolute determination is based on “elimination” of the DF of a reference capacitor by subtracting DF readings from two successive measurements. This method was applied to the calibration of DF in the range 5 × 10−6 to 1 × 10−2 at voltages up to 1 kV. Results obtained using this method were confirmed by comparing them with DF obtained using different methods The developed DF standard could be used to calibrate DF for commercial capacitors and DF methods.

We established an ex-situ technique for evaluating hydrogen gas permeability by thermal desorption analysis (TDA) gas chromatography (GC) and by self-developed diffusion analysis software. Absorbed hydrogen mass in rubber, related to the GC-peak area, is recorded as a function of elapsed time after decompressing the hydrogen under high-pressure. From the charging amount (CH0) and diffusivity (D) obtained by the developed diffusion analysis program, the solubility(S) and permeability(P) is evaluated via Henry’s law and P = SD, respectively. The techniques were applied to ethylene propylene diene monomer (EPDM) rubber, sealing material candidates in hydrogen infrastructures. EPDM sample mixed with carbon black fillers showed dual hydrogen diffusion behaviors, whereas EPDM sample without carbon black showed a single hydrogen diffusion behavior. There was no appreciable pressure or size dependence on D, S and P. P are consistent with that measured by different researcher within the expanded uncertainty.

The dielectric permittivity of synthetic rubber polymers, nitrile butadiene rubber (NBR) and ethylene propylene diene monomer (EPDM), with both frequency and temperature variations, was thoroughly investigated by dielectric relaxation spectroscopy (DRS). The spectrum versus frequency of DRS was analyzed with the semiempirical Havriliak–Negami formula and conductivity contribution by employing the newly developed “dispersion analyzer” analysis program. The main dielectric relaxations called the α- and β-processes, associated with the cooperative motion of chains in polymers, were discovered in the low-temperature region. In the high-temperature region, we found Maxwell–Wagner–Sillars (MWS) relaxation associated with polymer interfacing and normal-mode (α’) relaxation responsible for end-to-end dipole vector motion. The activation energies of schematic molecular chains responsible for the relaxation processes were obtained with the information about its motional mode. The glass transition temperature and dipole moment for the side group were also determined and compared with those from previous studies. In the EPDM specimen, the peaks of α- and β-relaxation merged at high temperature and were separated with decreasing temperature. The first observations of both merging and splitting were consistent with the results on the temperature dependency of the relaxation strength. Both contour mapping and three-dimensional plots for the two rubbers provide visual information for the distribution and mapping of relaxation.

We report two different volumetric analysis techniques to determine the transport properties of hydrogen dissolved in rubbery polymers. This measures the volume filled by the released hydrogen from rubber by gas collection in a graduated cylinder and by gas chromatography after exposure a sample with high-pressure hydrogen and decompression. From the measurement results, the uptake (C∞), diffusion coefficient (D), and solubility (S) of hydrogen are quantified by employing an upgraded diffusion analysis program. These methods are applied to three cylindrical rubber samples. Dual adsorption behaviors with increasing pressure are observed for all rubber samples. C∞ follows Henry's law up to ∼15 MPa, whereas the Langmuir model applies up to 90 MPa. No size dependence are observed for C∞ and S, whereas pressure-dependent D shows Knudsen and bulk diffusion behavior below and above a critical pressure, respectively. The S and D measured in two techniques are consistent with each other within the expanded uncertainty evaluated. A COMSOL simulation is compared with experimental investigations.

Permeation of hydrogen gas (H2) into nitrile butadiene rubber (NBR), which is one of the strong candidates for sealing material in H2 energy infrastructures, was quantified using a gas chromatography (GC) and a self-developed diffusion-analysis program. NBR samples were charged with H2 in a high-pressure chamber for 24 h then decompressed into atmosphere, and the mass of H2 released from the sample was measured as a function of elapsed time after decompression. The developed program calculated the total charging amount C0 and diffusivity D, which were then used to calculate the H2 solubility S and permeability P for variation of pressure. The samples were polymerized with and without carbon black (CB) filler in cylindrical shapes with different diameters. It appeared that the filler contributes to increase S and decrease D. The uncertainty analysis against the evaluated data was carried out, too, in order that the method could be applicable as a standard test for the permeation properties of various polymer membranes.

The complex dielectric permittivity of fluoroelastomers in response to both frequency and temperature variations was thoroughly investigated by dielectric relaxation spectroscopy. To characterize the various types of relaxation processes, the dispersion spectra of permittivity in the frequency domain were successively deconvoluted using a newly developed simulation program that uses the empirical Havriliak-Negami model based on the Debye dielectric model and conductivity contribution. At 233 K ≤ T ≤ 290 K, the α and β relaxation processes were independently observed; they merged at T ≥ 290 K. At T > 303 K, and both Maxwell-Wagner-Sillars (MWS) relaxation, known as interfacial polarization, and conductivity relaxation processes were observed. From the α relaxation process, which is related to the glass transition phenomenon, the glass transition temperature Tg was determined using the Vogel-Fulther-Tamman-Hesse (VFTH) temperature dependence law; the result was similar to the estimate of Tg obtained using differential scanning calorimetry. The temperature dependence of conductivity complies well with VFTH behaviors, whereas the β and MWS processes can be described using the Arrhenius temperature dependence law. The corresponding activation energies of the rotational side groups and DC conductivity were obtained.

Three techniques for determining the hydrogen permeation properties of rubber samples were developed based on the volumetric and gravimetric measurements of released H2 gas after sample decompression. These methods include gas chromatography (GC) by thermal desorption analysis (TDA), volumetric collection (VC) measurement of hydrogen by graduated cylinder and gravimetric (GM) measurement by electronic balance. By measuring the released hydrogen against elapsed time after the decompression of pressure, the charging amount (C0) and diffusivity (D) were obtained with the developed diffusion analysis program. From these values, the solubility (S) and permeability (P) of polymers were evaluated through the relations of Henry's law and P = S D , respectively. The developed techniques were applied to three kinds of spherically shaped sealing rubber materials. D, S and P were analyzed as a function of pressure. The transport behaviors obtained in the three methods are discussed and compared with the characteristics of each measuring technique. The correlations between transport parameters and carbon black filler or density are discussed.

We experimentally studied the comprehensive optical properties of the laser lines and fluorescent spectrum generated by a continuous tunable cholesteric liquid crystal (CLC) laser array. We found that the laser lines generated from a CLC with a right-handed circular helix were right-handed circular polarized and laser lines generated from a CLC with a left-handed circular helix were left-handed circular polarized. Inside the photonic band gap, the CLC structure with right-(left-) handed helicity suppressed the fluorescence generated with right (left) circular polarized light, and instead the suppressed right (left) circular polarized light energy moved to the outside of the photonic band gap, so we can say that the fluorescence intensity outside of the photonic band gap is enhanced with right (left) handed circular polarized light. Depending on the position of the photonic band gap, the fluorescence quantum yield value increased by up to ∼15%. These enhanced fluorescence intensities at the PBG edge will evolve into lasing at the upper lasing threshold. It is particularly interesting to see that the fluorescence intensity and shape could be controlled by adjusting the external geometrical factor of the photonic band gaps. The lasing threshold of the CLC lasers was in the range of 1.5–5.3 μJ/pulse. For CLC laser device applications, it is necessary and essential to know the optical properties of the generated laser lines and of the fluorescence spectrum.

Fine-structured polymerized cholesteric liquid crystal (PCLC) wedge laser devices have been realized, with high fine spatial tunability of the lasing wavelength. With resolution less than 0.3 nm in a broad spectral range, more than one hundred laser lines could be obtained in a PCLC cell without extra devices. For practical device application, we studied the stability of the device in detail over time, and in response to strong external light sources, and thermal perturbation. The PCLC wedge cells had good temporal stability for 1 year and showed good stability for strong perturbations, with the lasing wavelength shifting less than 1 nm, while the laser peak intensities decreased by up to 34%, and the high energy band edge of the photonic band gap (PBG) was red shifted 3 nm by temperature perturbation. However, when we consider the entire lasing spectrum for the PCLC cell, the 1-nm wavelength shift may not matter. Although the laser peak intensities were decreased by up to 34% in total for all of the perturbation cases, the remaining 34% laser peak intensity is considerable extent to make use. This good stability of the PCLC laser device is due to the polymerization of the CLC by UV curing. This study will be helpful for practical CLC laser device development.

We introduce the concept ofq-deformed probability and discuss theq-deformed binomial distribution.

In this paper we obtain the new expression for the number operator of the q-deformed oscillator algebra including theq = 0 case and prove the equivalence between this expression and an earlier one given by theq-number forq>0.

In this paper we investigate aq=0 plane which cannot be obtained by puttingq=0 in the Wess-Zumino formalism and has no classical analog.

In this paper a newq-derivative is proposed and its properties are discussed. We defineq-addition and study its axiomatic properties. Theq-exponents andq-logarithmic function are introduced and their algebraic structure discussed.

In this paper we discuss q-deformed classical mechanics. We set up the q-deformed Lagrangian and obtain the q-deformed equation of motion by using the variation technique. In this calculation we regard time as a discrete q-deformed variable.

We obtain the commutation relation between rows and columns ofN ×N quantum matrices. We derive the quantum determinant and discuss its property in terms of the q-deformed Levi-Civita symbol. We find the inverse and trace ofN×N quantum matrices. Finally we discuss the q-deformed complexification of the quantum matrices.

In this paper we use a special choice of the GLX,qij(2N) quantum plane and its differential calculus for a q-deformed phase space to define a modified Poisson bracket and construct the contraction rule for the q-deformed Levi-Civita symbol. We find the q-deformed phase-space variable realization of the soq(3) and q-deformed Poincare algebras.

In this paper we construct a generalized deformed algebra having the q-deformed Heisenberg-Weyl algebras and Tamm-Dancoff algebra as its special cases. We also show that the algebra is a Hopf algebra. Moreover we obtain a realization of the generalized deformed su(N) algebra in terms of the generalized deformed Heisenberg-Weyl algebra and discuss the deformed harmonic oscillator problem.

In the framework of stochastic quantization, the conformal anomaly of Fujikawa's string theory is derived and the standard dimension {ital D}=26 is obtained once again. It is shown that the quantum origin of that anomaly comes from a breaking of the naive Leibnitz formula in stochastic processes.

The gauge transformations, Becchi-Rouet-Stora structures, and gauge-invariant actions are constructed for the higher-spin fields in representations [n,1] and [2,2], where [${n}_{1}$,${n}_{2}$,...,${n}_{i}$,. . . ] denotes the Young tableaux with the ${n}_{i}$ box in the ith column.