Evaluation of thermal soak times

A mathematical model for the heat transfer within the electronics package of a Chaparral missile was performed. The Grashof number for this configuration was less than 2000 which indicated that the primary mode of heat transfer was conduction. The Vodicka theory for heat conduction in laminated composite media was utilized to obtain the solution for the model

Computation of steady and unsteady quasi-one-dimensional viscous/inviscid interacting internal flows at subsonic, transonic, and supersonic Mach numbers

Computations of viscous-inviscid interacting internal flowfields are presented for steady and unsteady quasi-one-dimensional (Q1D) test cases. The unsteady Q1D Euler equations are coupled with integral boundary-layer equations for unsteady, two-dimensional (planar or axisymmetric), turbulent flow over impermeable, adiabatic walls. The coupling methodology differs from that used in most techniques reported previously in that the above mentioned equation sets are written as a complete system and solved simultaneously; that is, the coupling is carried out directly through the equations as opposed to coupling the solutions of the different equation sets. Solutions to the coupled system of equations are obtained using both explicit and implicit numerical schemes for steady subsonic, steady transonic, and both steady and unsteady supersonic internal flowfields. Computed solutions are compared with measurements as well as Navier-Stokes and inverse boundary-layer methods. An analysis of the eigenvalues of the coefficient matrix associated with the quasi-linear form of the coupled system of equations indicates the presence of complex eigenvalues for certain flow conditions. It is concluded that although reasonable solutions can be obtained numerically, these complex eigenvalues contribute to the overall difficulty in obtaining numerical solutions to the coupled system of equations

Spheromak formation and sustainment studies at the sustained spheromak physics experiment using high-speed imaging and magnetic diagnostics

A high-speed imaging system with shutter speeds as fast as 2 ns and double frame capability has been used to directly image the formation and evolution of the sustained spheromak physics experiment (SSPX) [E. B. Hooper et al., Nucl. Fusion 39, 863 (1999)]. Reproducible plasma features have been identified with this diagnostic and divided into three groups, according to the stage in the discharge at which they occur: (i) breakdown and ejection, (ii) sustainment, and (iii) decay. During the first stage, plasma descends into the flux conserver shortly after breakdown and a transient plasma column is formed. The column then rapidly bends and simultaneously becomes too dim to photograph a few microseconds after formation. It is conjectured here that this rapid bending precedes the transfer of toroidal to poloidal flux. During sustainment, a stable plasma column different from the transient one is observed. It has been possible to measure the column diameter and compare it to CORSICA [A. Tarditi et al., Contrib. Plasma Phys. 36, 132 (1996)], a magnetohydrodynamic equilibrium reconstruction code which showed good agreement with the measurements. Elongation and velocity measurements were made of cathode patterns also seen during this stage, possibly caused by pressure gradients or E×B drifts. The patterns elongate in a toroidal-only direction which depends on the magnetic-field polarity. During the decay stage the column diameter expands as the current ramps down, until it eventually dissolves into filaments. With the use of magnetic probes inserted in the gun region, an X point which moved axially depending on current level and toroidal mode number was observed in all the stages of the SSPX plasma discharge

PCBs: Old Chemicals Present New Challenges

2014 S.C. Water Resources Conference - Informing Strategic Water Planning to Address Natural Resource, Community and Economic Challenge

Physicochemical characterization of the PEG8000-Na2SO4 aqueous two-phase system

The polyethylene glycol-sodium sulfate aqueous two-phase system has been characterized at 23 °C. Tielines for the phase diagram were obtained experimentally. Phases in equilibrium were characterized by means of the solvatochromic parameters π*, α, and β, which provide a measurement of the polarity/polarizability and the H-bond donor and acceptor abilities, respectively. The ability of the phases to participate in hydrophobic interactions was characterized by means of the free energy of transfer of a methylene group between the conjugated phases, using the partition of a homologous series of dinitrophenylated amino acids. The results show the effect of the presence of polymer and salt in the aqueous phase, and a comparison of both phases with pure water is made.LSRE-PortoUniversidade Católica PortuguesaEscola Superior de Biotecnologia do PortoFundação para a Ciência e a Tecnologia (FCT

Reductive C−C Coupling from α,β‐Unsaturated Nitriles by Intercepting Keteniminates

We present an atom‐economic strategy to catalytically generate and intercept nitrile anion equivalents using hydrogen transfer catalysis. Addition of α,β‐unsaturated nitriles to a pincer‐based Ru−H complex affords structurally characterized κ‐N‐coordinated keteniminates by selective 1,4‐hydride transfer. When generated in situ under catalytic hydrogenation conditions, electrophilic addition to the keteniminate was achieved using anhydrides to provide α‐cyanoacetates in high yields. This work represents a new application of hydrogen transfer catalysis using α,β‐unsaturated nitriles for reductive C−C coupling reactions.An atom‐economic strategy to catalytically generate and intercept nitrile anion equivalents by hydrogen transfer catalysis has been developed. Addition of α,β‐unsaturated nitriles to a pincer‐based Ru−H complex affords keteniminates by selective 1,4‐hydride transfer, which were employed in a net hydrogenative acylation reaction.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/149503/1/anie201904530.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/149503/2/anie201904530-sup-0001-misc_information.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/149503/3/anie201904530_am.pd

From Burdens To Benefits: The Societal Impact Of PDL-Enriched, Efficacy-Enhanced Educators

Societies continue to absorb increased burdens in cost for helping citizens unable to achieve at optimal levels.  Building on past research, we project educational benefits to offset current societal burdens through enhanced educator capabilities.  Studies reviewed show participation in a high-impact professional development and learning solution resulted in improved student performance and reduced dropout rates, reduced disciplinary rates and increased rates for college-bound, along with lower teacher turnover.  Computations show that generalization of such impacts should trade societal burdens for benefits at between $3.7 billion and$6.9 billion within the first year.  Cumulatively within 20 years the burdens converted to benefits are projected to exceed $85 billion.  Enhanced educator capabilities will substantively reduce needs and costs for societal programs, replaced with tangible benefits to all