Set & Drift: Department of Defense Operations During the Cuban Crisis

A Report by Adam Yarmolinsky, Special Assistant to the Secretary of Defense, 13 February 196

Un rattrapage raté . II. La variation à court terme

Comme pour la première phase de notre étude comparative du changement au Québec par rapport à l'Ontario durant le quart de siècle 1950-1974 (R.S., XVIII, 1, 1977), cette analyse est basée sur un ensemble de séries chronologiques annuelles portant sur quarante-huit indicateurs socio-économiques. Nous traitons ici les variations résiduelles, une fois les tendances extraites, sous mode d'abord synchronique puis diachronique. Les corrélations entre variables décalées dans le temps permettent l'exploration de liens séquentiels qui ouvrent la voie à l'interprétation causale. Les résultats de cette analyse permettent de confirmer certaines interprétations acquises et de mettre en relief l'importance d'un processus d'adaptation démographique au Québec

Un rattrapage raté. La changement social dans le québec d'après-guerre, 1950-1974 : une comparaison Québec/Ontario

Partant d'une position théorique aussi inductive que possible et travaillant avec des séries de données empiriques portant sur vingt-cinq années consécutives, les auteurs scrutent quelques-unes des tendances de fond socio-économiques qui se sont manifestées dans la période de l'après-guerre. Se servant d'une méthodologie qui comporte un agencement de techniques statistiques à l'intérieur de laquelle l'analyse des tendances ne représente que la première de trois étapes (les deux autres devant être réalisées ultérieurement), on soumet les tendances à un examen comparatif, Québec-Ontario. Cet examen se poursuit à la lumière des interprétations existantes sur le changement social dans le Québec de l'après-guerre et à l'aide des concepts d'industrialisation, de modernisation et de progrès social. En plus de mettre en relief quelques-unes de ces interprétations existantes, on cherche à constater jusqu'à quel point, relativement à l'Ontario, le Québec a su s'industrialiser, a été touché par la modernisation et a connu le progrès social

Electron-Ion Equilibrium and Shock Precursors in the Northeast Limb of the Cygnus Loop

We present an observational study using high-resolution echelle spectroscopy of collisionless shocks in the Cygnus Loop supernova remnant. Measured Hα line profiles constrain pre-shock heating processes, shock speeds, and electron-ion equilibration (Te /Ti ). The shocks produce faint Hα emission line profiles, which are characterized by narrow and broad components. The narrow component is representative of the pre-shock conditions, while the broad component is produced after charge transfer between neutrals entering the shock and protons in the post-shock gas, thus reflecting the properties of the post-shock gas. We observe a diffuse Hα region extending about 25 ahead of the shock with line width ~29 km s–1, while the Hα profile of the shock itself consists of broader than expected narrow (36 km s–1) and broad (250 km s–1) components. The observed diffuse emission arises in a photoionization precursor heated to about 18,000 K by He I and He II emission from the shock, with additional narrow component broadening originating from a thin cosmic-ray precursor. Broad to narrow component intensity ratios of ~1.0 imply full electron-ion temperature equilibration Te Ti in the post-shock region. Broad component line widths indicate shock velocities of about 400 km s–1. Combining the shock velocities with proper motions suggests that the distance to the Cygnus Loop is ~890 pc, significantly greater than the generally accepted upper limit of 637 pc

The Kepler End-to-End Model: Creating High-Fidelity Simulations to Test Kepler Ground Processing

The Kepler mission is designed to detect the transit of Earth-like planets around Sun-like stars by observing 100,000 stellar targets. Developing and testing the Kepler ground-segment processing system, in particular the data analysis pipeline, requires high-fidelity simulated data. This simulated data is provided by the Kepler End-to-End Model (ETEM). ETEM simulates the astrophysics of planetary transits and other phenomena, properties of the Kepler spacecraft and the format of the downlinked data. Major challenges addressed by ETEM include the rapid production of large amounts of simulated data, extensibility and maintainability

MSU Xtreme: Minnesota State University, Mankato\u27s Entry into the Clean Snowmobile Challenge 2001

Minnesota State University, Mankato’s Automotive Engineering Technology program formed a team to enter the Clean Snowmobile Challenge 2001. Selections for the organization’s machine included a 2001 Polaris Edge Chassis specially outfitted with a 2000 500 cc two-stroke Polaris engine. Modifications to the snowmobile were made specifically for Clean Snowmobile Challenge 2001 events. Acceleration, emissions, cold start, noise, fuel economy/range, handling/drivability, hill climb, and static display made up the list of events featured in the competition. MSU Xtreme has modified the snowmobile in every area with special emphasis on emissions and handling. Testing and analysis of the sled’s systems brought the team to its resulting design. The technical paper describes the results of those tests, explains the team design procedures, and presents all modifications made to the snowmobile

Ultrafast evanescent heat transfer across solid interfaces via hyperbolic phonon polaritons in hexagonal boron nitride

The efficiency of phonon-mediated heat transport is limited by the intrinsic atomistic properties of materials, seemingly providing an upper limit to heat transfer in materials and across their interfaces. The typical speeds of conductive transport, which are inherently limited by the chemical bonds and atomic masses, dictate how quickly heat will move in solids. Given that phonon-polaritons, or coupled phonon-photon modes, can propagate at speeds approaching 1 percent of the speed of light - orders of magnitude faster than transport within a pure diffusive phonon conductor - we demonstrate that volume-confined, hyperbolic phonon-polariton(HPhP) modes supported by many biaxial polar crystals can couple energy across solid-solid interfaces at an order of magnitude higher rates than phonon-phonon conduction alone. Using pump-probe thermoreflectance with a mid-infrared, tunable, probe pulse with sub-picosecond resolution, we demonstrate remote and spectrally selective excitation of the HPhP modes in hexagonal boron nitride in response to radiative heating from a thermally emitting gold source. Our work demonstrates a new avenue for interfacial heat transfer based on broadband radiative coupling from a hot spot in a gold film to hBN HPhPs, independent of the broad spectral mismatch between the pump(visible) and probe(mid-IR) pulses employed. This methodology can be used to bypass the intrinsically limiting phonon-phonon conductive pathway, thus providing an alternative means of heat transfer across interfaces. Further, our time-resolved measurements of the temperature changes of the HPhP modes in hBN show that through polaritonic coupling, a material can transfer heat across and away from an interface at rates orders of magnitude faster than diffusive phonon speeds intrinsic to the material, thus demonstrating a pronounced thermal transport enhancement in hBN via phonon-polariton coupling