1,053 research outputs found

    TLC determination of functionality in prepolymers

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    Application of thin-layer chromatographics provides rapid qualitative determination of functional distribution in experimental prepolymer. Functionality distribution is of fundamental importance for it determines; (1) manner in which given carboxyl-terminated prepolymer will cure and (2) physical properties of resulting product

    Glass transition temperatures of liquid prepolymers obtained by thermal penetrometry

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    Thermal penetrometry is experimental technique for detecting temperature at which frozen prepolymer becomes soft enough to be pierced by weighted penetrometer needle; temperature at which this occurs is called penetration temperature. Apparatus used to obtain penetration temperatures can be set up largely from standard parts

    Are There Any Redshift >8 Gamma-Ray Bursts in the BATSE Catalog?

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    Several luminosity indicators have been found for Gamma-Ray Bursts (GRBs) wherein measurable light curve and spectral properties are well-correlated with the peak luminosity. Several papers have each applied one different luminosity relation to find redshifts for BATSE GRBs and claim to identify specific bursts with z>8. The existence of such high redshift events is not surprising, as BATSE has enough sensitivity to see them and GRBs are expected out to the redshift of the first star formation. To improve results we used five luminosity relations with updated calibrations to determine redshifts with error bars. Combining these relations, we calculated the redshifts of 36 BATSE GRBs with claimed z>8. Our results include 13 bursts with our derived best redshift z_best>8, which looks promising at first. But the calculated redshift uncertainties are significantly large in these selected cases. With only one exception, all of our bursts have z_1siglow<9. The one exception (BATSE trigger 2035) is likely a short duration burst at z>~4. Our best case for a very high redshift event is BATSE trigger 3142 with z_best>20 and z_1siglow=8.9, however we can only say z>4.1 at the two-sigma confidence level. In all, we cannot point toward any one BATSE burst as confidently having z>8. One implication is to greatly weaken prior claims that GRBs have a steeply rising rate-density out to high redshifts.Comment: ApJ in press, 18 page

    Saturated hydrocarbon polymeric binder for advanced solid propellant and hybrid solid grains Quarterly report no. 2, 1 Feb. - 30 Apr. 1966

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    Synthesis and analysis of ethylene-neohexene copolymers with other non ketene-imine group free radicals for solid and hybrid grain propellant saturated hydrocarbon binder progra

    Acting out our dam future: science-based role-play simulations as mechanisms for learning and natural resource planning

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    Science often does not make its way into decisions, leading to a problematic gap between scientific and societal progress. To tackle this issue, our research tests a novel science-based negotiation simulation that integrates a role-play simulation (RPS) with a system dynamics model (SDM). In RPSs, stakeholders engage in a mock decision-making process (reflecting real-life institutional arrangements and scientific knowledge) for a set period. System dynamics models (SDMs) are visual tools used to simulate the interactions and feedback within a complex system. We test the integration of the two approaches with stakeholders in New England via a series of two consecutive workshops across two states. The workshops engage stakeholders from diverse groups to foster dialogue, learning, and creativity. Participants discuss a hypothetical (yet realistic) decision scenario to consider scientific information and explore dam management options that meet one another\u27s interests. In the first workshop, participants contributed to the design of the fictionalized dam decision scenario and the SDM. In the second workshop, participants assumed another representative\u27s role and discussed dam management options for the fictionalized scenario. This presentation will briefly report on the practical design of this science-based role-play, and particularly emphasize preliminary results of workshop outcomes, which were evaluated using debriefing sessions, surveys, concept mapping exercises, and interviews. Results will determine the extent to which this new knowledge production process leads to learning, use of science, and more collaborative decision-making about dams in New England and beyond

    Three-dimensional central-moments-based lattice Boltzmann method with external forcing: A consistent, concise and universal formulation

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    The cascaded or central-moments-based lattice Boltzmann method (CM-LBM) is a robust alternative to the more conventional BGK-LBM for the simulation of high-Reynolds number flows. Unfortunately, its original formulation makes its extension to a broader range of physics quite difficult. To tackle this issue, a recent work [A. De Rosis, Phys. Rev. E 95, 013310 (2017)] proposed a more generic way to derive concise and efficient three-dimensional CM-LBMs. Knowing the original model also relies on central moments that are derived in an adhoc manner, i.e., by mimicking those of the Maxwell-Boltzmann distribution to ensure their Galilean invariance a posteriori, a very recent effort [A. De Rosis and K. H. Luo, Phys. Rev. E 99, 013301 (2019)] was proposed to further generalize their derivation. The latter has shown that one could derive Galilean invariant CMs in a systematic and a priori manner by taking into account high-order Hermite polynomials in the derivation of the discrete equilibrium state. Combining these two approaches, a compact and mathematically sound formulation of the CM-LBM with external forcing is proposed. More specifically, the proposed formalism fully takes advantage of the D3Q27 discretization by relying on the corresponding set of 27 Hermite polynomials (up to the sixth order) for the derivation of both the discrete equilibrium state and the forcing term. The present methodology is more consistent than previous approaches, as it properly explains how to derive Galilean invariant CMs of the forcing term in an a priori manner. Furthermore, while keeping the numerical properties of the original CM-LBM, the present work leads to a compact and simple algorithm, representing a universal methodology based on CMs and external forcing within the lattice Boltzmann framework.Comment: Published in Phys. Fluids as Editor's Pic

    East Texas in the Election of 1860 and the Secession Crisis

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    Chronicles of Oklahoma

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    Article discusses conditions of the Confederate forces in Indian Territory towards the end of the Civil War through background information and inclusion of an inspection report by Lieutenant James Patterson, Assistant Inspector General
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