Continuous fiber thermoplastic prepreg

A pultrusion machine employing a corrugated impregnator vessel to immerse multiple, continuous strand, fiber tow in an impregnating material, and an adjustable metered exit orifice for the impregnator vessel to control the quantity of impregnating material retained by the impregnated fibers, is provided. An adjustable height insert retains transverse rod elements within each depression of the corrugated vessel to maintain the individual fiber tows spread and in contact with the vessel bottom. A series of elongated heating dies, transversely disposed on the pultrusion machine and having flat heating surfaces with radiused edges, ensure adequate temperature exposed dwell time and exert adequate pressure on the impregnated fiber tows, to provide the desired thickness and fiber/resin ratio in the prepreg formed. The prepreg passing through the pulling mechanism is wound on a suitable take-up spool for subsequent use. A formula is derived for determining the cross sectional area opening of the metering device. A modification in the heating die system employs a heated nip roller in lieu of one of the pressure applying flat dies

A comparison of the feeding values of red clover hays of low and average phosphorus supplement, as the roughage in the ration for growing calves

This thesis is a report of work done by The University of Tennessee Experiment Station during the year of 1941-42 with which the writer assisted. The experiment was a continuation of work begun in 1939 to obtain information relating to the effects of feeding red clover hays of varying phosphorus contents to growing beef calves (3). Results from the first year\u27s work indicated that when beef calves were fed rations in which hays of varied phosphorus content furnished the roughage the animals receiving the high-phosphorus red clover hay made better use of their feed, maintained a higher blood phosphorus and a thriftier condition, as evidenced by making greater gains and more growth than animals receiving the low-phosphorus hay of the same species . At the end of the first year\u27s experiment it was thought advisable to continue the work. The objective for the second year\u27s work was to study the growth of calves fed rations differing only in the phosphorus content of the red clover hays” (14). Results obtained for the second year were not consistent with those for 1939. The low phosphorus hay gave consistently better results as measured by gain in weight. It was thought that this might be due to certain undesirable factors (e.g. foreign matter) in the high-phosphorus hay. Also, the phosphorus content of the low-phosphorus hay used during the second year contained 0.16 percent phosphorus which was considerably above that for either the first or third year. The work was continued this past year to (A) compare the feeding value of a red clover hay of a good average phosphorus content with one of low phosphorus content, as the roughage in wintering ration for growing calves, and (B) to compare the effects of adding a liberal phosphorus supplement to rations fed for objective A

The treatment of delinquent negro girls in three North Carolina cities.

Thesis (M.A.)--Boston Universit

Doris Waltz : Doris, The Village Maiden

https://digitalcommons.library.umaine.edu/mmb-ps/2062/thumbnail.jp

Comparison of flexural properties of aramid-reinforced pultrusions having varied matrices, pretreatments and postcures

Aramid-reinforced composite materials of equal fiber volume and varied polymer thermoset matrices were pultruded and flexurally tested to failure. The objective was to improve the flexural properties of aramid-reinforced pultrusions. Pultrusions of both sized and unsized aramid fiber with four different resin systems were compared to determine the effects of sizing compounds and postcuring on flexural strength, fiber wettability, and fiber-to-resin interface bonding. Improvements in flexural strength resulting from pretreatments with the sizing solutions used were marginal. The most significant improvements in flexural properties resulted from postcuring. Flexural strengths ranged from a low of 39,647 psi (273MPa) to a high of 80,390 psi (554 MPa), an overall increase of 103 percent. The fact that postcuring improved the flexural properties of the pultrusions of the four resin systems indicates that a full cure did not occur in any of the resin systems during the pultrusion process. The increased flexural strengths of the polyester and vinyl ester pultrusions were the most surprising. The four resin systems examined were Interplastic Corporation VE 8300 vinyl ester, Ashland Chemical Company Aropol 7430 Polyester, and Shell Chemical Company Epon 9302 and Epon 9310 epoxides

Potential for on-orbit manufacture of large space structures using the pultrusion process

On-orbit manufacture of lightweight, high-strength, advanced-composite structures using the pultrusion process is proposed. This process is adaptable to a zero-gravity environment by using preimpregnated graphite-fiber reinforcement systems. The reinforcement material is preimpregnated with a high-performance thermoplastic resin at a ground station, is coiled on spools for compact storage, and is transported into Earth orbit. A pultrusion machine is installed in the Shuttle cargo bay from which very long lengths of the desired structure is fabricated on-orbit. Potential structural profiles include rods, angles, channels, hat sections, tubes, honeycomb-cored panels, and T, H, and I beams. A potential pultrudable thermoplastic/graphite composite material is presented as a model for determining the effect on Earth-to-orbit package density of an on-orbit manufacture, the package density is increased by 132 percent, and payload volume requirement is decreased by 56.3 percent. The fabrication method has the potential for on-orbit manufacture of structural members for space platforms, large space antennas, and long tethers

Pultrusion Die Assembly

This invention relates generally to pultrusion die assemblies, and more particularly, to a pultrusion die assembly which incorporates a plurality of functions in order to produce a continuous, thin composite fiber reinforced thermoplastic material. The invention is useful for making high performance thermoplastic composite materials in sheets which can be coiled on a spool and stored for further processing

Ambolena Snow

Woman carrying rodhttps://scholarsjunction.msstate.edu/cht-sheet-music/4374/thumbnail.jp

Prairie Flowers

Title with flowers and leaves around Prairiehttps://scholarsjunction.msstate.edu/cht-sheet-music/7969/thumbnail.jp

Re-Assembled Botulinum Neurotoxin Inhibits CNS Functions without Systemic Toxicity

The therapeutic potential of botulinum neurotoxin type A (BoNT/A) has recently been widely recognized. BoNT/A acts to silence synaptic transmission via specific proteolytic cleavage of an essential neuronal protein, SNAP25. The advantages of BoNT/A-mediated synaptic silencing include very long duration, high potency and localized action. However, there is a fear of possible side-effects of BoNT/A due to its diffusible nature which may lead to neuromuscular blockade away from the injection site. We recently developed a “protein-stapling” technology which allows re-assembly of BoNT/A from two separate fragments. This technology allowed, for the first time, safe production of this popular neuronal silencing agent. Here we evaluated the re-assembled toxin in several CNS assays and assessed its systemic effects in an animal model. Our results show that the re-assembled toxin is potent in inhibiting CNS function at 1 nM concentration but surprisingly does not exhibit systemic toxicity after intraperitoneal injection even at 200 ng/kg dose. This shows that the re-assembled toxin represents a uniquely safe tool for neuroscience research and future medical applications