Plastic Hollow Fibers Research Articles

Plastic hollow fibers as a selective infrared radiation transmitting medium

Plastic hollow waveguides (used as fibers) for infrared (IR) transmission were made from plastic tubes covered, on the internal wall, with a metal layer (Ag) and growing a dielectric thin (AgI) overlayer by direct iodination on it. The existence of several absorption lines at given wavelengths in the middle infrared (mid-IR) region is predicted theoretically and measured experimentally. From the wavelengths of absorption lines the thickness of the AgI film has been computed. The average thickness of the AgI in the hollow waveguide increased with the iodination time and with the concentration of the iodine solution. The crystal size of the AgI was increased with the increase of the AgI thickness. By controlling the iodination process it was possible to make waveguides which can be employed as filters for various wavelengths of the transmitted mid-IR radiation.

Experimental Surgery on Dog's Stomach and Liver Using CO2 Laser Plastic Hollow Fibers: Technical Method

Plastic hollow fibers for the transmission of CO 2 laser energy in curved paths were produced by plating the inner surface of plastic tubes with a metal film and dielectric film upon it. These fibers can transmit high power up to 40 W at the outlet, with high transmission yield even through several bendings. A three-dimensional simulator was built to simulate paths in the dog's body and the outlet power was measured. From the achieved data the expected transmitted power during real surgery was appreciated. The fibers were checked for their influence on live tissues of dogs. Incisions were made in the liver and ulcers in the dogs' stomachs were treated. The fibers were inserted into the stomach through the dogs' esophagus. Complete healing was observed after four weeks.

Characterization of hollow fibers for the transmission of infrared radiation

Plastic hollow fibers were made from plastic tubes covered on the internal wall with a metal layer (a-type) or a metal layer and dielectric layer on top of it (b-type). The CO(2) laser energy transmission through the hollow fiber was measured as a function of the radius of curvature and the coupling lens (focal length at a constant fiber length). The yield of the transmission decreased in subtle curvatures (radius of curvature up to 100 cm) and remained almost constant as the curvature became sharper (down to radius of curvature of 13 cm). For the a-type fibers, the characteristics of attenuation depended on the focal length of the coupling lenses. The energy distribution at the output was measured and mapped. The experimental results showed that the maximum of the energy distribution is asymetrically positioned relative to the center and closer to the internal wall at a smaller bending radius. This was predicted in our previous theoretical calculation. The value of transmitted power attenuation was up to 1.4 dB/m. Maximum power at the output was 30 W, for a fiber of 50-cm length and a cross-sectional diameter of 1.9 mm. These types of hollow fiber have already been used in surgical experiments on dogs.

Preliminary experiments of possible uses in medicine of novel plastic hollow fibers for transmission of CO2 radiation

Plastic hollow fibers for the transmission of CO2 laser energy in curved paths were produced by plating the inner surface of plastic tubes with a metal film and dielectric film upon that. These fibers can transmit high power, up to 40 W at the outlet, with high transmission yield even through several bendings. To demonstrate a possible use of the fibers, they were checked for their influence on live tissues of dogs. Incisions were made in the liver, and ulcers in the dogs' stomachs were treated. The fibers were inserted into the stomach through the esophagus. Complete healing was observed after 4 weeks.

CONTROLLED-RELEASE SEX PHEROMONE LURES FOR MONITORING SPRUCE BUDWORM POPULATIONS

AbstractFive formulations of the primary sex pheromone components of the spruce budworm (Choristoneura fumiferana [Clem.]) were evaluated as lures for monitoring spruce budworm populations: Biolures (Consep Membranes Inc.), Luretape plastic flakes (Hercon, Healthchem Corp.), polyethylene vials (International Pheromone Systems), hollow fibers (Albany International), and polyvinyl chloride (PVC) pellets. PVC pellets showed significant loss in attractiveness over the required 6-week period. Also, different batches of PVC pellets had very different rates of pheromone release and attraction; the oldest lures, stored for the longest period, were the most attractive. Luretape caught fewer moths than anticipated from the release-rate data and showed wide variation in catch among individual lures. Fibers were inconsistent. Biolures and polyethylene vials showed the lowest decline in attractiveness over time and the lowest variation in catch among individual lures, but their capture rates were higher than necessary.

Nonsaturating Traps and Long-Life Attractant Lures for Monitoring Spruce Budworm Males12

The trapping efficacy of various nonsaturating, pheromone-baited traps was contrasted with standard sticky traps for males of Choristoneura fumiferana (Clemens). Several nonsaturating designs that employed a vaporous insecticide (dichlorvos) were comparable in terms of trap catch to fresh sticky traps. Such nonsaturating traps may prove useful in programs to monitor spruce budworm population dynamics. Commercial formulations of ( E ) and (Z)-11-tetradecenal (ca. 97:3) in a plastic laminate or hollow fibers proved effective over several weeks in luring males.

Pressure-flow relations of human blood in hollow fibers at low flow rates.

Suspensions of human red cells in citrated plasma, in Ringer solution, and in Ringer solution containing albumin were passed through straight and curved glass and plastic hollow fibers (diameter range, 100–1,000 μ). Pressure-flow relations were measured over the pressure range of 0.1– 800 mm water, corresponding to a shear stress range of 0.01– 80 dynes/cm2. The suspensions were tested simultaneously in a rotational viscometer. It was found that red cell suspensions exhibit a yield shear stress only if the plasma protein fibrinogen is present. Experimental pressure-flow data in hollow fibers were in excellent agreement with rotational viscometer measurements and with analytical predictions based on the assumptions that blood flows as a homogeneous continuum and that the velocity at the wall is zero. Effects of tube surface characteristics and curvature on the pressure drop-flow rate relation were not discernible. microcirculation models; model blood flow; yield stress of blood; capillary blood flow and viscometry; fibrinogen and blood flow in hollow fibers; non-Newtonian flow of blood in hollow fibers Submitted on July 20, 1964