Quantitative Estimation of Dark Muscle Content in the Mackerel Meat Paste and its Products Using Antisera Against Myosin Light Chains

ABSTRACT: Based on the high level of extractability of myosin subunits (light chains), even after prolonged heat treatment of muscle, a new method to evaluate the dark muscle content in the fish meat and products of mackerel is proposed. Tissue-specific rabbit antisera with myosin light chains (A1 from ordinary muscle and D1 from dark muscle) from mackerel Scomber japonicus were obtained. Mackerel meat paste (surimi) was dissolved in 8 M urea containing 1% SDS, and diffused on agar plates containing antiserum against A1 or D1 by single radial immunodiffusion (SRID). The results obtained showed that the area of halos formed in the plates was quite proportional to the content of dark muscle.     

Consideration of the band-gap tunability of BaSi2 by alloying with Ca or Sr based on the electronic structure calculations

The electronic structures and total energies of BaSi₂-SrSi₂ and BaSi₂-CaSi₂ systems have been calculated using the first-principle pseudopotential method to clarify the band gap tunability of BaSi₂ by alloying with Sr or Ca. From an energetic consideration of the compounds where all the Ba_I sites or all the Ba_II sites of the BaSi₂ lattice are preferentially replaced by Sr or Ca, it is expected that the Ba_I site will be preferentially replaced by Sr rather than the Ba_II sites. Compounds where all the Ba_II sites are replaced by Sr or all the Ba_II or all the Ba_I sites are replaced by Ca are energetically unfavorable compared to the undissolved system of BaSi₂ and SrSi₂ or CaSi₂. The effect of the addition of Sr or Ca into the BaSi₂ lattice on the gap value is different depending on the replaced sites of Ba. The replacement of Ba_I site by Sr will broaden the band gap of BaSi₂, which is consistent with the observed results.     

Low-temperature deposition of crystallized TiO2 thin films

Crystallized TiO₂ thin films were deposited on a non-heated substrate by two methods: oxygen-ion-assisted reactive evaporation (ORE) and high-rate reactive sputtering (HRS) using two sputtering sources. When the films were deposited on an unheated glass substrate, amorphous films were initially grown on the substrate in case of both deposition methods, although an increase in oxygen-ion energy above 600 eV led to a growth of a crystallized layer on the amorphous films in the case of ORE. When the films were deposited by HRS on a crystallized TiO₂ seed layer, homo-epitaxial growth was observed, and crystallized TiO₂ films with an excellent hydrophilic property were obtained on unheated substrate. In contrast, when the films were deposited by ORE, amorphous films were initially grown on the crystallized TiO₂ seed layer in a similar manner to the deposition of films on a glass substrate, and homo-epitaxial growth was not observed. These results suggest that the large kinetic energy of titanium atoms arriving at the substrate during HRS is a key factor in promoting epitaxial growth of the TiO₂ film at low temperature.     

Effects of grain refinement on surface enhancement of thin-film chlorine-doped crystalline selenium

In this study, the surface enhancement of thin-film crystalline selenium (c-Se) is successfully demonstrated through grain refinement using chlorine (Cl) doping. We fabricated c-Se films via doping with various halogens, such as Cl, bromine (Br), and iodine (I). In particular, for Cl, we prepared c-Se films with different doping concentrations of 0, 50, and 500 ppm on glass substrates to investigate the details of concentration effects on surface enhancement. The long helical chains of Se atoms that comprise a large molecule in hexagonal Se, which is the most stable form of Se, are terminated via halogen doping into Se, leading to a marked reduction in the size of polycrystalline grains. In addition, the grain size of c-Se sharply decreases as the Cl doping concentration is increased. The mean surface roughness of a 500-ppm-Cl-doped c-Se film measured via atomic force microscopy decreased to approximately one-fourth that of the equivalent undoped c-Se film. This is a promising technology that could bring great benefits to c-Se-based imaging devices.     

Effects of a barrier on creeping discharge characteristics in SF6 and N2 gases under pulse voltages

This paper describes the effect of a barrier on creeping discharge characteristics in SF₆, N₂, and their mixtures. The barrier height effect on the discharge voltage was investigated under a positive pulse voltage. The discharge voltage increased with increasing barrier height in SF₆ gas. On the other hand, the discharge voltage hardly changed with the barrier height in N₂ gas. In order to clarify the mechanism of the initial creeping corona, it was observed by optical techniques, including an ultra-high-speed electronic imaging system (IMACON 468). The creeping corona path revealed differences in images at various barrier heights. The accumulated charge induced on the barrier by the initial corona in SF₆ gas was able to suppress the development of the later creeping corona, in contrast with N₂ gas. © 1998 Scripta Technica, Electr Eng Jpn, 125(4): 1–8, 1998     

Vibration control of two-mass system with low inertia ratio considering practical use

In some industrial motor-drive systems, a torsional vibration is often generated because of an elastic element in torque transmission. Such a mechanical system is modeled as a two-mass system and it is well-known that the suppressing vibration of a low inertia ratio two-mass system where the motor inertia is larger than the load inertia is very difficult. This paper proposes a speed control system of a low-inertia ratio system, taking into account not only the dynamic responses but also a robust stability. The proposed control system is based on the H^∞ control theory and the resonance ratio control due to the feedback of the estimated shaft torque. Combining the H^∞ controller with the resonance ratio controller, the control system with high robust stability can be obtained comparing with the conventional resonance ratio control. The variable feedback gain system and the construction of the disturbance observer are discussed in order to reject the effects of noise. The simulated and experimental results show that the proposed speed control system is useful for the two-mass system with low inertia ratio. ©1998 Scripta Technica, Electr Eng Jpn, 125(2): 1–9, 1998     

Generalized analysis of operating limits on PM motors and suitable machine parameters for constant-power operation

Permanent magnet synchronous motors (PM motors) are widely used in industrial applications. Some applications such as electric vehicles and compressor drives require constant-power operation. The available maximum power under specified voltage and current constraints can be obtained by optimal current vector control, such as maximum torque control and flux-weakening control. The operating limits, however, strongly depend on the machine parameters. This paper examines the relationships between the machine parameters and the output characteristics. It is shown that the power-versus-speed characteristic depends only on the difference between the magnet flux linkage and the maximum flux linkage of the d-axis armature reaction. The maximum torque and the constant-power operating range are obtained as functions of this difference. The optimal machine parameters and the design of PM motors for constant power operation are discussed based on the overall analytical results and on analyses that takes into account both copper loss and core loss in light-load operation. © 1998 Scripta Technica. Electr Eng Jpn, 123(3): 55–63, 1998     

Relationship between IgA Nephropathy and Porphyromonas gingivalis; Red Complex of Periodontopathic Bacterial Species

IgA nephropathy (IgAN) has been considered to have a relationship with infection in the tonsil, because IgAN patients often manifest macro hematuria just after tonsillitis. In terms of oral-area infection, the red complex of periodontal bacteria (Porphyromonas gingivalis (P. gingivalis), Treponema denticol (T. denticola) and Tannerella forsythia (T. forsythia)) is important, but the relationship between these bacteria and IgAN remains unknown. In this study, the prevalence of the red complex of periodontal bacteria in tonsil was compared between IgAN and tonsillitis patients. The pathogenicity of IgAN induced by P. gingivalis was confirmed by the mice model treated with this bacterium. The prevalence of P. gingivalis and T. forsythia in IgAN patients was significantly higher than that in tonsillitis patients (p < 0.001 and p < 0.05, respectively). A total of 92% of tonsillitis patients were free from red complex bacteria, while only 48% of IgAN patients had any of these bacteria. Nasal administration of P. gingivalis in mice caused mesangial proliferation (p < 0.05 at days 28a nd 42; p < 0.01 at days 14 and 56) and IgA deposition (p < 0.001 at day 42 and 56 after administration). Scanning-electron-microscopic observation revealed that a high-density Electron-Dense Deposit was widely distributed in the mesangial region in the mice kidneys treated with P. gingivalis. These findings suggest that P. gingivalis is involved in the pathogenesis of IgAN.     

Formation energies of two-dimensional nuclei randomly-generated on (001), (110), and (111) planes of a face-centered-cubic crystal

Monte-Carlo simulations of the two-dimensional crystal nucleus growth on (001), (110) and (111) crystal planes of a face-centeredcubic lattice have been conducted considering: (1) the adsorption of an atom from the surrounding gases, (2) its surface diffusion, (3) its annihilation, and (4) its being incorporated into the crystal nucleus. The energy of the formed nucleus was calculated using the bond-splitting model with reference to the energy of atoms at the half-crystal position and its dependence on the nucleus size were evaluated. The results implies that Pangarov's theory to explain the dependence of preferred orientation on the supersaturation might have to be amended in case above dynamic processes have a vital effect on the shape of nucleus of deposited thin films.     

Deposits obtained by photolysis of hexamethyldisilane by ArF excimer laser (SiC thin film preparation by ArF excimer laser chemical vapor deposition, Part 2)

Thin films have been prepared by decomposition of hexamethyldisilane (HMDS) by ArF excimer laser at the fixed laser fluence of 800 J m⁻² and the substrate temperatures from 300 to 673 K and have been characterized using X-ray diffraction (XRD), scanning electron microscope observation, IR reflection spectroscopy and X-ray photoelectron spectroscopy. The XRD patterns showed the formation of 3C-SiC films but it is suggested that the films obtained at lower substrate temperature include organic functional groups, which might be derived from gaseous reaction products. Hydrogen existing in the form of Si-CH₂-Si could be decreased by decreasing the partial pressures of HMDS.