3,899 research outputs found
Further infrared systems studies for the earth resources program Final report
Design of multispectral scanner for orbital earth resources detectio
Summary of recent investigations of inlet flow distortion effect on engine stability
A review is presented of recent experimental results, analytical procedures and test techniques employed to evaluate the effects of inlet flow distortion on the stability characteristics of representative afterburning turbofan and turbojet compression systems. Circumferential distortions of pressure and temperature, separately and in combination are considered. Resulting engine sensitivity measurements are compared with predictions based on simplified parallel compressor models and with several distortion descriptor parameters
The MiMeS Project: Magnetism in Massive Stars
The Magnetism in Massive Stars (MiMeS) Project is a consensus collaboration
among the foremost international researchers of the physics of hot, massive
stars, with the basic aim of understanding the origin, evolution and impact of
magnetic fields in these objects. The cornerstone of the project is the MiMeS
Large Program at the Canada-France-Hawaii Telescope, which represents a
dedication of 640 hours of telescope time from 2008-2012. The MiMeS Large
Program will exploit the unique capabilities of the ESPaDOnS spectropolarimeter
to obtain critical missing information about the poorly-studied magnetic
properties of these important stars, to confront current models and to guide
theory.Comment: 6 pages, 3 figures, proceedings of IAUS 259: Cosmic Magnetic Field
Energy loss rates of two-dimensional hole gases in inverted Si/Si0.8Ge0.2 heterostructures
We have investigated the energy loss rate of hot holes as a function of carrier temperature TC in p-type inverted modulation-doped (MD) Si/SiGe heterostructures over the carrier sheet density range (3.5–13)×1011 cm–2, at lattice temperatures of 0.34 and 1.8 K. It is found that the energy loss rate (ELR) depends significantly upon the carrier sheet density, n2D. Such an n2D dependence of ELR has not been observed previously in p-type SiGe MD structures. The extracted effective mass decreases as n2D increases, which is in agreement with recent measurements on a gated inverted sample. It is shown that the energy relaxation of the two-dimensional hole gases is dominated by unscreened acoustic phonon scattering and a deformation potential of 3.0±0.4 eV is deduced
Comparison of turbojet-engine altitude performance characteristics and ignition limits with MIL-F-5624A fuel, grades JP-3 and JP-4
The performance of MIL-F-5624A fuels, grades JP-3 and JP-4, was investigated in an axial-flow turbojet engine over a range of altitude conditions of 10,000 to 55,000 feet. Examination of the fuel flow, combustion efficiency, and net thrust specific fuel consumption showed the grade JP-4 fuel to be slightly inferior to the grade JP-3 fuel, although the altitude ignition limits were essentially equal for the two fuels over a range of flight Mach numbers and fuel-inlet temperatures
Ex-Spouses’ Relational Satisfaction as a Function of Coparental Communication in Stepfamilies
This study tested a series of actor-partner interdependence models of coparental communication and relational satisfaction among ex-spouses living in stepfamilies. Participants included 41 ex-spousal dyads (N = 82). Results revealed two actor-oriented models whereby ex-spouses’ supportive and antagonistic coparental communication predicted their own (but not their ex-spouse’s) relational satisfaction. A second set of models revealed that nonresidential parents’ supportive and antagonistic coparental communication with the residential stepparent predicted their own satisfaction with their ex-spouses, as well as their ex-spouse’s satisfaction with them (i.e., a partner effect). Importantly, the findings demonstrate the interdependence of coparenting relationships in stepfamilies, as supportive coparental communication between nonresidential parents and their exspouse’s new partner (i.e., the stepparent) predicted meaningful variance in relational satisfaction for both ex-spouses
Ex-Spouses’ Relational Satisfaction as a Function of Coparental Communication in Stepfamilies
This study tested a series of actor-partner interdependence models of coparental communication and relational satisfaction among ex-spouses living in stepfamilies. Participants included 41 ex-spousal dyads (N = 82). Results revealed two actor-oriented models whereby ex-spouses’ supportive and antagonistic coparental communication predicted their own (but not their ex-spouse’s) relational satisfaction. A second set of models revealed that nonresidential parents’ supportive and antagonistic coparental communication with the residential stepparent predicted their own satisfaction with their ex-spouses, as well as their ex-spouse’s satisfaction with them (i.e., a partner effect). Importantly, the findings demonstrate the interdependence of coparenting relationships in stepfamilies, as supportive coparental communication between nonresidential parents and their exspouse’s new partner (i.e., the stepparent) predicted meaningful variance in relational satisfaction for both ex-spouses
Effects of prenatal depressive symptoms on maternal and infant cortisol reactivity.
Prenatal depression is associated with adverse offspring outcomes, and the prevailing mechanistic theory to account for mood-associated effects implicates alterations of the maternal and foetal hypothalamic-pituitary adrenal (HPA) axes. Recent research suggests that depression may be associated with a failure to attenuate cortisol reactivity during early pregnancy. The aim of the current study is to investigate whether this effect continues into mid and late gestation. A further aim is to test whether maternal prenatal cortisol reactivity directly predicts infant cortisol reactivity. One hundred three pregnant women were recruited during either the second or third trimester. Depressive symptoms were assessed by self-report, and maternal salivary cortisol responses to a stressor (infant distress film) were measured. Approximately 2 months after birth, mothers (n = 88) reported postnatal depression and infant salivary cortisol responses to inoculation were measured. Prenatal depression was not associated with cortisol reactivity to acute stress in mid and late pregnancy. Similarly, neither prenatal depression nor maternal prenatal cortisol reactivity predicted infant cortisol reactivity to inoculation at 2 months. If the effects of prenatal depression on foetal and infant development are mediated by alterations of the maternal and foetal HPA axes, then early pregnancy may be a particularly vulnerable period. Alternatively, changes to HPA reactivity may not be as central to this association as previously thought
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