Analytical Investigation of the Reentry Behavior of the ''flying Wind Tunnel'' Test Vehicle, with Some Effects of Threshold and Torque Level of a Roll-rate Control System

Analytical investigation of reentry behavior of flying wind tunnel test vehicle with some effects of threshold and torque level of roll-rate control syste

Allylic Displacement Reactions of a 2-Acetamido-D-glucal Derivative with Acids and Phenols

Fusion of 3,4,6-tri-O-acetyl-2-(N-acetylacetamido)-1,2-dideoxy- o-arabino-hex-1-enopyranose [I, 2-(N-acetylacetamido)-o-glucal triacetate] with various acids and phenols in the presence of. a trace of p-toluenesulfonic acid causes loss of the acetoxy group at C-3, shift of the double bond to the C-2-C-3 position, and entry of an acyloxy or aryloxy group at C-1 to give esters and glycosides, respectively, of 4,6-di-0-acetyl-2-(N-acetylacetamido)-2,3-dideoxy- a-o-erythro-hex-2-enopyranose (compounds III, V, VI, and VII). In each case, the main product is accompanied by 1,4,6-tri-O- acetyl-2- (N-acetylacetamido) -2,3-dideoxy-a-o-erythro-hex-2-enopyranose (IV), a substance which is found to be readily accessible through the deliberate rearrangement of I under acidic conditions. While IV reacts with benzoic acid when boiled in benzene solution containing hydrogen chloride, I is recovered unchanged after treatment in this fashion. On the basis of these facts, a mechanism for the acid-catalyzed reaction of I with carboxylic acids and phenols is proposed. An improved preparation of I from 2-acetamido-2-deoxy-omannose via 2-acetamido-1,3,4,6-tetra-O-acetyl-2-deoxy-a-o-mannopyranose (II) is described. Phenyl 4,6-di-0-acetyl-2-(N -acetylacetamido )-2,3-dideoxy-a-D- eryth ro-hex-2-enopyranoside (VI) may be reduced by catalytic hydrogenation to the corresponding cyclohexyl glycoside (VIII), the double bond remaining unaffected

The Rearrangement Reaction of Some Acetylated Unsaturated 2-Acetamidoaldose Derivatives. Selective Removal of one N-Acetyl Group from 2-(N-acetylacetamido) Compounds

Two pairs of anomers, the l ,4,6-tri-0-acetyl-2-(N-acetylacetamido)- 2,3-dideoxy-o-hex-2-enopyranoses of the erythro- (II and III) and the threo- series (IV and VI) have been prepared and character; ized. The molecular conformation of these substances has been discussed on the basis of their NMR spectral characteristics. It is suggested that the a-anomers II and IV adopt the H~ conformation as the favorable one, while the B-anomers III and VI most probably tend to take a slightly modified H~ conformation. A convenient preparative method for selective removal of one N-acetyl group from 0-acetylated N-acetylacetamido compounds is described. The reaction can be carried out in aqueous dioxane solution at room temperature in the presence of an ammonium salt at pH ca. 9

Same traits, different variance : Item-Level Variation Within Personality Measures

© 2014 the Author(s). This article has been published under the terms of the Creative Commons Attribution License. Without requesting permission from the Author or SAGE, you may further copy, distribute, transmit, and adapt the article, with the condition that the Author and SAGE Open are in each case credited as the source of the article. The version of record, Jamie S. Churcyard, Karen J. Pine, Shivani Sharma, Ben (C) Fletcher, ' Same Traits, Difference Variance: Item-Level Variation Within Personality Measures', SAGE Open, 2014, is available online via doi: 10.1177/2158244014522634Personality trait questionnaires are regularly used in individual differences research to examine personality scores between participants, although trait researchers tend to place little value on intra-individual variation in item ratings within a measured trait. The few studies that examine variability indices have not considered how they are related to a selection of psychological outcomes, so we recruited 160 participants (age M = 24.16, SD = 9.54) who completed the IPIP-HEXACO personality questionnaire and several outcome measures. Heterogenous within-subject differences in item ratings were found for every trait/facet measured, with measurement error that remained stable across the questionnaire. Within-subject standard deviations, calculated as measures of individual variation in specific item ratings within a trait/facet, were related to outcomes including life satisfaction and depression. This suggests these indices represent valid constructs of variability, and that researchers administering behavior statement trait questionnaires with outcome measures should also apply item-level variability indices.Peer reviewedFinal Published versio

Bostonia. Volume 14

Founded in 1900, Bostonia magazine is Boston University's main alumni publication, which covers alumni and student life, as well as university activities, events, and programs

Nernst quantum oscillations in bulk semi-metals

With a widely available magnetic field of 10 T, one can attain the quantum limit in bismuth and graphite. At zero magnetic field, these two elemental semi-metals host a dilute liquid of carriers of both signs. When the quantum limit is attained, all quasi-particles are confined to a few Landau tubes. Each time a Landau tube is squeezed before definitely leaving the Fermi surface, the Nernst response sharply peaks. In bismuth, additional Nernst peaks, unexpected in the non-interacting picture, are resolved beyond the quantum limit. The amplitude of these unexpected Nernst peaks is larger in the samples with the longest electron mean-free-path.Comment: Accepted for publication in Journal of Physics: Condensed Matter's special issue on Strongly Correlated Electron Systems(SCES

Transverse Magnetoresistance of GaAs/AlGaAs Heterojunctions in the Presence of Parallel Magnetic Fields

We have calculated the resistivity of a GaAs\slash AlGaAs heterojunction in the presence of both an in--plane magnetic field and a weak perpendicular component using a semiclassical Boltzmann transport theory. These calculations take into account fully the distortion of the Fermi contour which is induced by the parallel magnetic field. The scattering of electrons is assumed to be due to remote ionized impurities. A positive magnetoresistance is found as a function of the perpendicular component, in good qualitative agreement with experimental observations. The main source of this effect is the strong variation of the electronic scattering rate around the Fermi contour which is associated with the variation in the mean distance of the electronic states from the remote impurities. The magnitude of the positive magnetoresistance is strongly correlated with the residual acceptor impurity density in the GaAs layer. The carrier lifetime anisotropy also leads to an observable anisotropy in the resistivity with respect to the angle between the current and the direction of the in--plane magnetic field.Comment: uuencoded file containing a 26 page RevTex file and 14 postscript figures. Submitted to Phys. Rev.

Novel Josephson effects between multi-gap and single-gap superconductors

Multi-gap superconductors can exhibit qualitatively new phenomena due to existence of multiple order parameters. Repulsive electronic interactions may give rise to a phase difference of $\pi$ between the phases of the order parameters. Collective modes due to the oscillation of the relative phases of these order parameters are also possible. Here we show that both these phenomena are observable in Josephson junctions between a single-gap and a multi-gap superconductor. In particular, a non-monotonic temperature dependence of the Josephson current through the junction reveals the existence of the $\pi$ phase differences in the multi-gap superconductor. This mechanism may be relevant for understanding several experiments on the Josephson junctions with unconventional superconductors. We also discuss how the presence of the collective mode resonantly enhances the DC Josephson current when the voltage across the junction matches the mode frequency. We suggest that our results may apply to MgB$_2$, 2H-NbSe$_2$, spin ladder and bilayer cuprates.Comment: 4 pages, 2 figure