Long-chain fatty acids containing ether linkage. I. The antibacterial and fungicidal activities of some new β-alkyloxypropionic acids and their methyl esters

β-Alkoxypropionic acids and their methyl esters were made with alkoxy groups ranging from C₄H₉O to C₁₈H₃₅O: R-O-CH₂CH₂COOH (CH₃). Methyl esters and acids were also made with one and with two oxyethylene groups between the alkoxy group and the propionic acid group: RO (CH₂ CH₂ O) n-CH₂CH₂ COOH(CH₃). The compounds were tested againstStaphylococcus aureus and againstPenicillium for growth inhibition. The optimum size of the alkoxy group appears to be R=C₁₂H₂₅. Oxyethylene groups enhanced the activity againstS. aureus, but had relatively little effect againstPenicillium.     

Modification of Takaishi-Sensui formula for a diaphragm gauge system connected by an arbitrary length pipe

The thermal transpiration effect in a vacuum system, where a circular pipe connects a capacitance diaphragm gauge (CDG) and a vacuum vessel, was numerically investigated using the direct simulation Monte Carlo (DSMC) method. The simulated pressure ratios were plotted versus the Knudsen number K, over the range 10⁻³ ≤ K ≤ 10³, for a fixed diameter and various pipe lengths. The curve obtained here was compared with that obtained using the Takaishi-Sensui formula (T-S curve). For a long pipe, with λ ≥ 10, (λ: aspect ratio of length to diameter), the simulated curve agreed well with the T-S curve over the entire examined range of K. For a shorter pipe (λ < 10), the simulated curve seemed to shift in the low K (high pressure) direction, with respect to the T-S curve, and the distance between the curves abruptly increased with decreasing λ. The discrepancy for a short pipe was found to be removable by rescaling the Knudsen number. The discrepancy that originally existed for a long pipe could also be reduced, if the reflection on the pipe wall obeyed an incompletely accommodated Maxwell model.     

Possible role of dentin matrix in region-specific deposition of cellular and acellular extrinsic fibre cementum

The mechanism whereby a region-specific deposition of the two types of cementum (cellular cementum and acellular extrinsic fibre cementum) is regulated on the growing root surface was tested using bisphosphonate-affected teeth of young rats and guinea pigs. The animals were injected subcutaneously with 8 or 10 mg P x kg body weight(-1) x day(-1) of 1-hydroxyethylidene-1,1-bisphosphonate (HEBP) for 1 or 2 weeks. In rat molars, HEBP prevented mineralization of newly formed root dentin matrix and totally inhibited de novo deposition of acellular extrinsic fibre cementum. Instead, thick cellular cementum was induced on the non-mineralized root dentin surface, irrespective of the position of the root. In both animals, cellular cementum was also induced on the non-mineralized surface of root analogue dentin in HEBP-affected incisors, where only acellular extrinsic fibre cementum is deposited under normal conditions. In normal rat molars, dentin sialoprotein (DSP) was concentrated along the dentin-cellular cementum border, but not that of dentin and acellular extrinsic fibre cementum. In HEBP-affected rat incisors, DSP was shown to penetrate through the non-mineralized dentin into the surrounding tissues, but not through the mineralized portions. These data suggest that, at the site of cellular cementum formation, putative inducing factors for cellular cementum might diffuse into the periodontal space through the newly deposited mantle dentin matrix before it is mineralized. At earlier stages of root formation, mantle dentin might mineralize more promptly not to allow such diffusion. The timing of mineralization of mantle dentin matrix might be the key determinant of the types of the cementum deposited on the growing root surface.     

Mars14 Monte Carlo simulation for the shielding studies of the J-PARC 3 GeV ring

MARS14 Monte Carlo simulations were performed for collimation and shielding studies of the J-PARC 3 GeV synchrotron ring. The beam line module locations in the 348.3 m ring and the curved tunnel sections were described by the 'MAD-MARS beam line builder' tool. A 400 MeV proton beam loss distribution, calculated with the STRUCT code, was used as a 4 kW source term in the collimator region, with 1 kW source terms in the injection and extraction regions at 400 MeV and 3 GeV, respectively. Deep penetration calculations were carried out with good statistics using a newly developed three-dimensional multi-layer technique. Prompt dose-rate distributions were calculated inside and outside the concrete and soil shield up to the ground level. Using the calculation results obtained thus, an effective shielding design was made.     

Oxygen pressure measurements of silica saturated Fe-O-SiO2 melts by the emf method using zirconia solid electrolyte

The thermodynamic properties of silica-saturated iron silicate slags have been studied from oxygen partial pressure measurements using a solid electrolyte galvanic cell. The oxygen activity in molten silver bath equilibrated with iron silicate slags was determined by the following cell type, Pt, Ni-NiO/O=/slag-Ag(O), LaCrO₃, Pt at temperatures between 1473 and 1573 K for the slags ranging in compositions from iron saturation to magnetite saturation. The oxygen partial pressures obtained in this investigation were in good agreement with those given by the previous study using the CO-CO₂ gas equilibrium method. The data showed that the Fe⁺⁺⁺/Fe⁺⁺ ratio is proportional toP _{o 2} ^¼     

Bimodal fingerprint capturing system based on compound-eye imaging module

A compact imaging system called TOMBO (Thin Observation Module by Bound Optics) is proposed in which a microlens array is used for thin hardware configuration. This paper describes a fingerprint-capturing module as an application of the TOMBO. Experimental results by the TOMBO prototype system are shown to clarify the applicability of the TOMBO to the fingerprint capturing. Different types of biometrics, i.e., fingerprint and face images, are captured by the same hardware, which shows the extendability of the system for multimodal identification.     

Impact-damage visualization in CFRP by resistive heating: Development of a new detection method for indentations caused by impact loads

Rapid and automatic inspection of composite aircraft after every flight would reduce the safety factor and allow for more flights. Although, an electrical resistance change method (ERCM) has been proposed, there are many problems with its practical application. In this study, a new diagnostic method, impact-damage visualization, was developed. Indentation damage increases fiber-fiber contact at the interlaminar interface and electrical conductivity. Consequently, electrical current applied to the material will concentrate around the damaged area, and lead to selective and intense resistive heating. This temperature increase can be observed by thermography or detected as a change in electrical resistance caused by the temperature difference. The proposed method had sufficient reliability and sensitivity for practical application as a damage inspection method.     

Ultrastructural and histochemical evaluation of appositional mineralization of circumpulpal dentin at the crown- and root-analog portions of rat incisors

Mineralization of circumpulpal dentin has been interpreted in such a way that predentin matrix is abruptly converted to almost fully mineralized dentin at the mineralization front. A group of investigators pointed out the existence of intermediary layer along the mineralization front of rat incisor dentin and claimed that dentin mineralization is a rather transient process. Owing to a paucity of information, however, the entity of transient mineralization of dentin has remained elusive. Here we confirmed the existence of a lightly mineralized layer (LL) along the mineralization front of rat incisor dentin, recognizable by both light and electron microscopy, in routinely processed specimens. LL less than 3?μm thick was shown to be located along the mineralization front of crown-analog dentin and tapered out toward the root analog of the incisor. Electron microscopy revealed that mineral deposition first occurred in the non-collagenous matrix of LL and that mineralization of collagen fibers took place sometime later at the conventional mineralization front. Microscopic appearance of the mineral phase of LL varied considerably depending on the histological processing of ultrathin sections, thus explaining the inconsistent interpretation of dentin mineralization in previous studies. These data suggest that mineralization of circumpulpal dentin in rat incisors proceeds in a stepwise or a transient manner, initiated by crystal deposition in the non-collagenous matrix followed by massive mineral deposition in collagen fibers at the mineralization front. The thickness of LL where only the non-collagenous matrix is mineralized may vary in relation to differences in the local non-collagenous matrix and also the rate of collagen mineralization in the respective portions of circumpulpal dentin.