No abstract available

[en] The design thermoplastic-film recording camera and its performance for holography of extended objects are reported. Special corona geometry and accurate control of development heat by constant current heating and high resolution measurement of the develop temperature make easy recording of reproducible, large aperture holograms possible. The experimental results give the transfer characteristics, the diffraction efficiency characteristics and the spatial frequency response. (orig.)

[en] We report the dependence of the ortho-positronium (o-Ps) lifetime τ₃ and intensity I₃ on the thermodynamic history of a number of amorphous homopolymer and copolymer glasses that were pressure-densified at pressures up to 200 MPa. Small macroscopic volume changes up to 1.85% yield large microscopic volume changes in the pressure-densified glasses, i.e., τ₃ decreases by a maximum of 9%, while I₃ remains constant, and the Simha-Somcynsky free-volume fraction decreases by a maximum of 31% and correlates with the free-volume size Vτ₃.

[en] This study was performed to localize the high frequency ultrasonic transducers using polyvinylidene fluoride (PVDF) and polyvinylidene fluoride trifluorethylene (copolymer). The characteristics of fabricated high frequency transducers such as beam diameter, frequency spectrum and pressure level of the first echo signal from the specimen in the water were analyzed and compared. As test specimens, the steel balls with 0.5 mm and 1.5 mm diameter and steel block with 30 mm thick were used. The high frequency detection field of a transducer was affected by increasing the length of cable between high frequency transducer and ultrasonic pulser/receiver. As the size of a specimen increased, the high frequency detection field decreased and the amplitude of a reflection signal increased. The pressure level of copolymer tranduser was found to be higher than that of PVDF transducer but the high frequency detection field of PVDF was wider than that of copolymer.

No abstract available

[en] We study the conformational behavior in a plane of a comb copolymer molecule, consisting of a semiflexible backbone and rigid side chains interacting via a van der Waals potential. Using a mean-field approach, two different regimes are distinguished depending on the strength of the attraction between the side chains. In the weak attraction limit the side chains are oriented preferably perpendicular to the backbone. The persistence length λ of the comb copolymer molecule scales as the second power of the length of the side chain L: λ∝L². In the strong attraction limit all side chains become strongly tilted and the persistence length scales as λ∝L⁴. The nonlinear bending regime is also studied and characterized by a change in structure and a decreasing moment of bending force as a function of curvature, i.e., bending becomes easier

[en] Purpose: In irradiating high energy radioactive rays to a sheet-like continuous organic polymer to improve the properties of the polymer, to effect irradiation so that absorbing dose of the irradiated body is even over the entire width of the sheet. Constitution: In travelling an irradiated body composed of a lengthy organic polymer under the radioactive ray irradiating window for irradiation of the radioactive rays, the irradiated body is reversed for plural times passing through a plurality of inclined guide rolls so that the irradiated body may travel along the passage in the form of a multilayer. In this manner, the irradiated body may be travelled under the irradiating window successively from the first layer to the uppermost layer or in the order reversed thereto for accomplishment of irradiation about one half of the desired radiation dose. Thereafter, the irradiated body is travelled with the inclination angle of the body to the irradiation window reversed to irradiate radioactive rays in the quantity of the remaining about one half to thereby irradiate the desired dose of the radioactive rays. (Yoshihara, H.)

[en] A volatile organic compound (VOC) transport model has been developed to describe unsteady-state VOC permeation and diffusion within a waste drum. Model equations account for three primary mechanisms for VOC transport from a void volume within the drum. These mechanisms are VOC permeation across a polymer boundary, VOC diffusion across an opening in a volume boundary, and VOC solubilization in a polymer boundary. A series of lab-scale experiments was performed in which the VOC concentration was measured in simulated waste drums under different conditions. A lab-scale simulated waste drum consisted of a sized-down 55-gal metal drum containing a modified rigid polyethylene drum liner. Four polyethylene bags were sealed inside a large polyethylene bag, supported by a wire cage, and placed inside the drum liner. The small bags were filled with VOC-air gas mixture and the VOC concentration was measured throughout the drum over a period of time. Test variables included the type of VOC-air gas mixtures introduced into the small bags, the small bag closure type, and the presence or absence of a variable external heat source. Model results were calculated for those trials where the VOC permeability had been measured. Permeabilities for five VOCs [methylene chloride, 1,1,2-trichloro-1,2,2-trifluoroethane (Freon-113), 1,1,1-trichloroethane, carbon tetrachloride, and trichloroethylene] were measured across a polyethylene bag. Comparison of model and experimental results of VOC concentration as a function of time indicate that model accurately accounts for significant VOC transport mechanisms in a lab-scale waste drum

[en] System concepts have been developed which could provide a significant time delay against a penetration attempt by a terrorist force. The delay time is achieved through the use of a variety of urethane foam produced obstacles that increase the amount of equipment and demolition devices an intruder must carry to progress into the facility

No abstract available