Measurements of discharge ion distribution around an anode wire of a gas counter

Measurements of the discharge ion distribution around an anode wire of a gas counter are performed with a single wire counter having an additional signal wire. The weighting function which relates the induced signal on the signal wire to the initial ion distribution is derived analytically. Results of measurements of average angular distribution of the discharge ions around the anode wire are shown. In addition to the proportional mode, discharge ion spatial distribution in the self-quenching streamer mode is observed.     

Identity of alpha-glucosidase of human kidney with urine F-1 alpha-glucosidase

alpha-Glucosidase was extracted from a homogenate of human kidney, initially with 0.02 M Tris-HCl buffer, pH 7.6, and subsequently with a mixture of 0.5% cholate and 0.5% Triton X-100 in the same buffer, pH 7.6. The enzyme in each of these two fractions was purified to the electrophoretically pure state by fractional precipitation with ammonium sulfate, column chromatographies on DEAE-cellulose, hydroxyapatite, Bio Gel A-1.5 m and affinity chromatography on heated glutinous rice. The two purified alpha-glucosidase preparations obtained were the same in enzymatic and proteochemical properties, and the molecular weight and isoelectric point estimated were 3 x 10(5) and 4.2, respectively. No evidence for subunit structure was obtained. The optimum pH for activity was 5.6 and the activity was drastically inhibited by Nojirimycin. The alpha-glucosidase readily hydrolyzed maltose, starch, and glycogen, producing only glucose. It hydrolyzed maltotriitol to split the non-reducing end glucose, but scarcely hydrolyzed maltitol or various other heteroglucosides examined. All these proteochemical and enzymatic properties of kidney alpha-glucosidase were the same as those of urine F-1 alpha-glucosidase. Also, kidney tissue alpha-glucosidase produced a clear precipitin line with antisera against urine F-1 alpha-glucosidase. These facts suggest that F-1 alpha-glucosidase in urine originates from kidney tissue.     

Optical switch matrix with simplified N×Ntree structure

Optical switch matrices with compact size and excellent crosstalk characteristics are discussed. Novel architectures for optical switch matrices are obtained by condensing the structure of N× N tree structure. 4×4 switches fabricated on LiNbO₃ substrates are discussed     

Dietary induction of cholesterol gallstones in hamsters from three different sources

Cholesterol gallstones were produced in young male, golden Syrian hamsters, obtained from three different suppliers, by administering a nutritionally adequate, semipurified diet for periods of either 5 or 10 weeks. The major components of the lithogenic diet were casein, cornstarch, butterfat, corn oil and 0.3% cholesterol. The hamsters were obtained from Sesco, Harlan Sprague-Dawley (Engle hamster) and Charles River (Lakeview hamster). There were profound differences among the three groups with respect to gallstone formation and cholesterol metabolism: The highest incidence of gallstones occurred in Sesco hamsters, 44.4% and 63.6% after 5 and 10 weeks on the lithogenic diet, respectively. In the Engle hamster, after a 5-week feeding, cholesterol crystals and gallstones were absent. When the feeding period was extended to 10 weeks, cholesterol gallstones were present in 45.5% of the animals. In the Lakeview hamsters, neither gallstones nor cholesterol crystals were found in the gallbladder after a 5-week period. After 10 weeks, cholesterol gallstones were found in only a single hamster. In all groups, the lithogenic diet produced large increases of liver, serum and biliary cholesterol concentrations and increased liver weights. When the animals were fed for 5 weeks, only the bile of Sesco hamsters became supersaturated. Supersaturated bile was induced in all groups after a 10-week feeding of the lithogenic diet with cholesterol saturation ranging from 1.47 to 1.97. These data indicate that it is possible to induce cholesterol gallstones in hamsters by means of a nutritionally adequate, semipurified diet of moderate cholesterol content. The source of the animals appears to be an important variable, because there were significant differences among the hamsters of differing origins, in cholesterol metabolism and rates of gallstone formation.     

A Comparative Study on the Various In Vitro Assays of Active Oxygen Scavenging Activity in Foods

ABSTRACT: Various in vitro assays of active oxygen-scavenging activity in foods were compared by evaluating the activity of 13 food phenolic compounds and Trolox. 1,1-Diphenyl-2-picrylhydrazyl (DPPH)-HPLC and liposome oxidation methods were sensitive for these compounds, while deoxyribose oxidation and Randox kit methods were less sensitive. The deoxyguanosine oxidation method could not determine the activity since food polyphenols were pro-oxidative in this assay. Among these assays, the DPPH-HPLC method was shown to be the best since the liposome oxidation method is affected more by the structure of phenolic compounds than the DPPH-HPLC method.     

Secure optical memory system with polarization encryption

A novel secure holographic memory system with polarization encoding is proposed. Two-dimensional original data are encoded as a two-dimensional polarization distribution. The polarization state at each pixel is scrambled by a mask that changes the polarization state into a random state. The mask can rotate the direction of the principal axes of the elliptically polarized light and can change the phase retardation at each pixel. The light with the random polarization state is stored as a hologram that can produce the vector phase-conjugate beam. In the decryption the vector phase-conjugation readout can recover the original polarization state by use of the same mask used in the encryption. Experimental results of encryption and decryption with a bacteriorhodopsin film are presented.     

Real-time three-dimensional object recognition with multiple perspectives imaging

A novel system for recognizing three-dimensional (3D) objects by use of multiple perspectives imaging is proposed. A 3D object under incoherent illumination is projected into an array of two-dimensional (2D) elemental images by use of a microlens array. Each elemental 2D image corresponds to a different perspective of the 3D object. Multiple perspectives imaging based on integral photography has been used for 3D display. In this way, the whole set of 2D elemental images records 3D information about the input object. After an optical incoherent-to-coherent conversion, an optical processor is employed to perform the correlation between the input and the reference 3D objects. Use of micro-optics allows us to process the 3D information in real time and with a compact optical system. To the best of our knowledge this 3D processor is the first to apply the principle of integral photography to 3D image recognition. We present experimental results obtained with both a digital and an optical implementation of the system. We also show that the system can recognize a slightly out-of-plane rotated 3D object.     

Shift-invariant three-dimensional object recognition by means of digital holography

We present an optoelectronic method to analyze three-dimensional (3D) scenes that is able to detect the presence, and also the position and orientation, of a reference 3D object. The data-acquisition procedure is based on digital holography. A phase-shifting interferometer records a single digital Fresnel hologram of the 3D scene with an intensity-recording device. Holographic information of the 3D reference object is also obtained with the same method. Correlation techniques are then applied to recognize the presence and position of the 3D reference object in the 3D scene. The technique also allows us to detect the 3D reference with a small out-of-plane rotation. Preliminary experimental results are presented that demonstrate the theory.     

Novel crosslinking system with hydroxyl-containing polymer, alicyclic polyepoxide and polyalkoxysilane

The crosslinking system based on the reaction among alicyclic epoxide group, hydroxyl group and alkoxysilyl group in the presence of aluminum β-diketone chelate have been developed. Five kinds of reaction are possible, and the result of gas chromatography and infrared analyses indicated that the main reaction is the ring-opening reaction of alicyclic epoxide group with hydroxyl group and/or hydroxysilyl group. The acrylic resin obtained by free radical polymerization of these three kinds of functional monomers and non-functional monomers showed good curing property, and the film was superior in acid rain resistance and outdoor durability. The resin is suitable to use in automotive 2coat–1bake clear coat. The viscosity of this binder system was remarkably reduced by addition of a low molecular weight alicyclic polyepoxide compound and an alkoxysilane oligomer without affecting to its good curing property. Such a system made it possible to design novel high solid coatings. It was found that the crosslinking could be extended to the combination of a polyester polyol, an alicyclic epoxide compound and an alkoxysilane oligomer. In this case, it was necessary that the polyester polyol contained highly reactive terminal hydroxyl group in the branch chains.     

Sintering of Si3N4 with the Addition of Rare-Earth Oxides

The effect of rare-earth oxide additives on the densification of silicon nitride by pressureless sintering at 1600° to 1700°C and by gas pressure sintering under 10 MPa of N₂ at 1800° to 2000°C was studied. When a single-component oxide, such as CeO₂, Nd₂O₃, La₂O₃, Sm₂O₃, or Y₂O₃, was used as an additive, the sintering temperature required to reach approximate theoretical density became higher as the melting temperature of the oxide increased. When a mixed oxide additive, such as Y₂O₃–Ln₂O₃ (Ln=Ce, Nd, La, Sm), was used, higher densification was achieved below 2000°C because of a lower liquid formation temperature. The sinterability of silicon nitride ceramics with the addition of rare-earth oxides is discussed in relation to the additive compositions.