Silicone modified resins for graphite fiber laminates

The development of silicon modified resins for graphite fiber laminates which will prevent the dispersal of graphite fibers when the composites are burned is discussed. Eighty-five silicone modified resins were synthesized and evaluated including unsaturated polyesters, thermosetting methacrylates, epoxies, polyimides, and phenolics. Neat resins were judged in terms of Si content, homogeneity, hardness, Char formation, and thermal stability. Char formation was estimated by thermogravimetry to 1,000 C in air and in N2. Thermal stability was evaluated by isothermal weight loss measurements for 200 hrs in air at three temperatures. Four silicone modified epoxies were selected for evaluation in unidirectional filament wound graphite laminates. Neat samples of these resins had 1,000 C char residues of 25 to 50%. The highest flexural values measured for the laminates were a strength of 140 kpsi and a modulus of 10 Mpsi. The highest interlaminar shear strength was 5.3 kpsi

Silicone modified resins for graphite fiber laminates

Six silicone modified resins were selected for evaluation in unidirectional filament wound graphite laminates. Neat samples of these resins had 1,000 C char residues of 6-63%. The highest flexural values measured for the laminates were a strength of 1,220 MPa and a modulus of 105 GPa. The highest interlaminar shear strength was 72 MPa

Synthesis of pyrrone polymers, 21 June 1967 - 21 June 1968

Synthesis of pyrrone polymers by reactions of dianhydride and diacetoamido diamines or with tetramin

Taking a “Deep Dive”: What Only a Top Leader Can Do

Unlike most historical accounts of strategic change inside large firms, empirical research on strategic management rarely uses the day-to-day behaviors of top executives as the unit of analysis. By examining the resource allocation process closely, we introduce the concept of a deep dive, an intervention when top management seizes hold of the substantive content of a strategic initiative and its operational implementation at the project level, as a way to drive new behaviors that enable an organization to shift its performance trajectory into new dimensions unreachable with any of the previously described forms of intervention. We illustrate the power of this previously underexplored change mechanism with a case study, in which a well-established firm overcame barriers to change that were manifest in a wide range of organizational routines and behavioral norms that had been fostered by the pre-existing structural context of the firm.Strategic Change, Resource Allocation Process, Top-down Intervention

Early-type Galaxies in the Cluster Abell 2390 at z=0.23

To examine the evolution of the early-type galaxy population in the rich cluster Abell 2390 at z=0.23 we have gained spectroscopic data of 51 elliptical and lenticular galaxies with MOSCA at the 3.5 m telescope on Calar Alto Observatory. This investigation spans both a broad range in luminosity (-19.3>M_B>-22.3) and uses a wide field of view of 10'x10', therefore the environmental dependence of different formation scenarios can be analysed in detail as a function of radius from the cluster centre. Here we present results on the surface brightness modelling of galaxies where morphological and structural information is available in the F814W filter aboard the Hubble Space Telescope (HST) and investigate for this subsample the evolution of the Fundamental Plane.Comment: 5 pages, 5 figures, to appear in "Carnegie Observatories Astrophysics Series, Vol. 3: Clusters of Galaxies: Probes of Cosmological Structure and Galaxy Evolution", ed. J. S. Mulchaey, A. Dressler, and A. Oemler (Pasadena: Carnegie Observatories, http://www.ociw.edu/ociw/symposia/series/symposium3/proceedings.html

Labor Law - Evidence- Production of Pre-Trial Statements for Purpose of Cross-Examination in NLRB Proceeding

Respondent was accused of unfair labor practices. At the hearing before the trial examiner, respondent requested pre-trial statements of the general counsel\u27s witnesses who testified, for the purpose of impeaching their credibility on cross-examination. The trial examiner\u27s refusal was upheld by the NLRB. Upon motion to reopen the record, held, the record is reopened and further proceedings are to be held before the trial examiner. The holding of Jencks v. United States applies to NLRB proceedings; hence respondent has the right for cross-examination purposes to production of pre-trial statements made by the general counsel\u27s witnesses which directly relate to their testimony. Ra-Rich Mfg. Corp., 121 N.L.R.B. No. 90, 42 L.R.R.M. 1403 (1958)

Political Consequences of the development of Russia\u27s Inland Waterways

The foundation for present Russian industrial development was laid in the period 1925 to 1933. Russians, with the aid of American technicians built factories in accordance with American standards. They installed American equipment and machinery in these factories. At the same time they constructed huge dams and power plants. Russia was then a market for American products and certainly offered no competition to United States industry. This was so, even though it was recognized that within the great Russian land mass lay huge reserves of resources. Few recognized then that these factors could, if developed, enable Russia to build an industrial empire capable of challenging the United States. Attributes of location, area, population and natural resources which enabled the United States to become the world\u27s foremost industrial power were possessed also by Russia

Instructor Modeled Postural Positions and Their Influence on Instructional Test Scores of Tenth-grade Students

Purpose. The problem was to determine if instructor modeled postural positions Influence Instructional test scores of selected tenth-grade students. (Abstract shortened.

Anionic Transport in Nitella clavata

This study examines aspects of anion transport, focusing on Cl-, No3- and So4-2 in Nitella clavata. The researcher measures the uptake of radioactive Cl- in the presence/absence of a hexose in order to determine if glucose inhibits Cl- influx. The author grew Nitella clavata in open tanks of culture solution, with a light intensity of 100 foot-candles at the cultures’ surface. Only the first, second, or third intermodal cells proximal to the apical tip were used. Harvested cells were then conditioned from one to seven days under controlled conditions. First, the researcher used titration to measure net hydrogen ion influxes and hydroxide effluxes. Then the researcher treated cells in with K/experimental solutions and rinsed them in non-tracer/appropriate experimental solution in order to measure cell radioactivity. The researcher also measured unidirectional chloride efflux using a radioassay with a Nuclear-Chicago low background gas flow counter. Intracellular chloride activity was determined by measuring vacuolar sap chloride concentration potentiometrically. Ultimately, the researcher could find no evidence to support the hypothesis that Nitella clavata possesses a hexose/H+ cotransport system, nor could she provide evidence for a Cl-/H+ cotransport system through competitive inhibition with a hexose/H+ mechanism. Possibilities for further research include radioisotope tracing of NO3-, Cl- and SO4-2 in the presence of other anions