A second moment NMR method to study phase changes in bone

1985 ◽  
Vol 13 (1) ◽  
pp. 25-28 ◽  
Author(s):  
Anthony A. Silvidi ◽  
Stephen E. Dunn
Keyword(s):  
Phase Changes ◽  
Study Phase ◽  
Second Moment ◽  
Nmr Method

Phase offset indicator (POI): A study of phase shift versus offset and fluid content

Geophysics ◽  
1986 ◽  
Vol 51 (3) ◽  
pp. 679-688 ◽  
Author(s):  
B. Rafipour ◽  
E. Herrin
Keyword(s):  
Phase Shift ◽  
Theoretical Work ◽  
Linear Process ◽  
Phase Changes ◽  
Study Phase ◽  
Complex Spectrum ◽  
Angle Of Incidence ◽  
Matched Filters ◽  
Fluid Content ◽  
Saturated Medium

There is limited published experimental and theoretical work related to offset‐dependent reflection and phase changes at the interface between porous media. An appropriate relationship between seismic parameters and phase shift has not been well‐established. This investigation measures variations of phase for nonnormal incidence reflection as a function of frequency at the interface of a horizontally layered porous (perforated) medium, using a two‐dimensional Plexiglas model. In both parts of this study, phase‐matched filters (PMF) are used to analyze the data. Phase‐matched filters previously have been applied to digital records of Rayleigh waves and Love waves. The purpose of the first part of the study is to demonstrate application of the PMF process to reflected compressional waves and to use this technique in discriminating multiples from primaries. By using this linear process, the complex spectrum of the primary signal can be recovered from the multiple arrivals. The reduction of reflected compressional pulse wavelets to a zero‐phase wavelet provided a tool to examine the change in phase (and amplitude) as the wave travels through a lossy medium. The second part of the study deals with the relationship of phase shift Δϕ at an interface of a horizontally layered porous medium, as a function of fluid content, angle of incidence (offset), and frequency. The result indicates that, at midband frequency of 60 kHz, an air‐ (gas‐) saturated medium would cause a large increase in Δϕ with offset, whereas a water‐saturated medium would show less change in Δϕ with offset. The phase shift‐versus‐offset response for oil is assumed to be intermediate between the responses for gas and water.

Modeling the Effect of Phase Change on LNG Impact With Open-Source CFD

2018 ◽  
Author(s):  
Javier Calderon-Sanchez ◽  
Daniel Duque ◽  
Jesus Gómez-Goñi
Keyword(s):  
Phase Change ◽  
Open Source ◽  
Phase Changes ◽  
Maximum Pressure ◽  
Study Phase ◽  
Vapor Equilibrium ◽  
Pressure Impact ◽  
Phase Change Phenomena ◽  
Impact Events ◽  
Cryogenic Conditions

The phenomenology of loads due to sloshing impact on tanks, such as those in Liquefied Natural Gas (LNG) carriers, is a problem that is currently far from being fully assessed. A main particularity of LNG, among others (such as compressibility or hydroelasticity) is that it is carried at cryogenic temperatures, normally at liquid-vapor equilibrium. This implies phase changes may occur during sloshing impacts. However, phase change phenomena have normally been neglected in sloshing studies. Preliminary works from Behruzi et al. [1] and Ancellin et al. [2] show that phase change may have an effect on the maximum pressure load. The current work aims to study phase change phenomenology in pressure impact events at cryogenic conditions by implementing a phase change model in the open-source tool Open-FOAM. Results will be compared against previous work by the authors (Calderon-Sanchez et al. [3]), which did not feature phase change.

The Interpretation of Crystal Lattice Images

1972 ◽  
Vol 30 ◽  
pp. 550-551
Author(s):  
J. M. Cowley ◽  
Sumio Iijima
Keyword(s):  
Crystal Orientation ◽  
Diffraction Theory ◽  
Phase Changes ◽  
Electron Wave ◽  
Crystal Lattices ◽  
Heavy Atoms ◽  
Lattice Images ◽  
The Right ◽  
Intuitive Interpretation ◽  
Suitable Approximation

The imaging of detailed structures of crystal lattices with 3 to 4Å resolution, given the correct conditions of microscope defocus and crystal orientation and thickness, has been used by Iijima (this conference) for the study of new types of crystal structures and the defects in known structures associated with fluctuations of stoichiometry. The image intensities may be computed using n-beam dynamical diffraction theory involving several hundred beams (Fejes, this conference). However it is still important to have a suitable approximation to provide an immediate rough estimate of contrast and an evaluation of the intuitive interpretation in terms of an amplitude object.For crystals 100 to 150Å thick containing moderately heavy atoms the phase changes of the electron wave vary by about 10 radians suggesting that the “optimum defocus” theory of amplitude contrast for thin phase objects due to Scherzer and others can not apply, although it does predict the right defocus for optimum imaging.

Limitations to the Spacing Effect

2005 ◽  
Vol 52 (4) ◽  
pp. 257-263 ◽  
Author(s):  
Peter P. J. L. Verkoeijen ◽  
Remy M. J. P. Rikers ◽  
Henk G. Schmidt
Keyword(s):  
Free Recall ◽  
Phase Retrieval ◽  
Incidental Learning ◽  
Factor Model ◽  
Recall Performance ◽  
Spacing Effect ◽  
Word List ◽  
Intentional Learning ◽  
Study Phase ◽  
Learning Condition

Abstract. The spacing effect refers to the finding that memory for repeated items improves when the interrepetition interval increases. To explain the spacing effect in free-recall tasks, a two-factor model has been put forward that combines mechanisms of contextual variability and study-phase retrieval (e.g., Raaijmakers, 2003 ; Verkoeijen, Rikers, & Schmidt, 2004 ). An important, yet untested, implication of this model is that free recall of repetitions should follow an inverted u-shaped relationship with interrepetition spacing. To demonstrate the suggested relationship an experiment was conducted. Participants studied a word list, consisting of items repeated at different interrepetition intervals, either under incidental or under intentional learning instructions. Subsequently, participants received a free-recall test. The results revealed an inverted u-shaped relationship between free recall and interrepetition spacing in both the incidental-learning condition and the intentional-learning condition. Moreover, for intentionally learned repetitions, the maximum free-recall performance was located at a longer interrepetition interval than for incidentally learned repetitions. These findings are interpreted in terms of the two-factor model of spacing effects in free-recall tasks.

Study-Phase Retrieval: Suppressing False Recognition in a Repetition Paradigm

2007 ◽  
Author(s):  
Peter M. Wessels ◽  
Jonathan Schnader ◽  
Allison Smith ◽  
Christopher Thomas ◽  
Haley Titus
Keyword(s):  
False Recognition ◽  
Phase Retrieval ◽  
Study Phase

À propos de la folie et de l’amour dans Crime et Châtiment de Dostoïevski

2018 ◽  
pp. 138-144
Author(s):  
Ariane Bazan
Keyword(s):  
Second Moment

Crime et Châtiment raconte l’histoire de Raskolnikov à l’été 1865 à Petersbourg, qui assassine une vieille usurière et sa sœur. Dès avant son geste Raskolnikov se met au travail quant aux questions de la culpabilité, du châtiment et de la rédemption. Le texte présente la folie humaine selon deux modalités, la névrose et la psychose, chacune avec ses deux temporalités, c’est-à-dire un premier moment de conscience d’une séparation d’avec la réalité, et un second moment de séparation effective. Raskolnikov se trouve du côté de la psychose, sur un continuel point de basculement entre les deux temps et les folies de Catherina Ivanovna et, peut-être, d’Arcady Svidrigaïlov, se trouvent du côté de la névrose, avec seul Arcady qui ne bascule pas. La seconde idée est celle de l’enjeu du crime : peut-on se trouver parmi ses frères humains de cet amour inconditionnel qui serait capable d’aimer le criminel le plus abject ? Le paradoxe est que Raskolnikov, qui ne peut supporter la transgression au point de délirer une race pure, met au défi ce monde à aimer le coupable du crime le plus vil. Nous terminerons en proposant que l’amour ne puisse être qu’inconditionnel, même s’il ne peut être illimité.

Remote diagnostics of vibrations of dynamic objects by Doppler microwave sensors

Metrologiya ◽  
2020 ◽  
pp. 25-42
Author(s):  
Dmitrii V. Khablov
Keyword(s):  
Intelligent Systems ◽  
Electromagnetic Waves ◽  
Continuous Monitoring ◽  
Phase Changes ◽  
Vibration Diagnostics ◽  
Remote Diagnostics ◽  
Active Vibration ◽  
Dynamic Objects ◽  
Microwave Sensors ◽  
Non Destructive

This paper describes a promising method for non-contact vibration diagnostics based on the use of Doppler microwave sensors. In this case, active irradiation of the object with electromagnetic waves and the allocation of phase changes using two-channel quadrature processing of the received reflected signal are used. The modes of further fine analysis of the resulting signal using spectral or wavelet transformations depending on the nature of the active vibration are considered. The advantages of this non-contact and remote vibration analysis method for the study of complex dynamic objects are described. The convenience of the method for machine learning and use in intelligent systems of non-destructive continuous monitoring of the state of these objects by vibration is noted.

The Refusal of Politics

2016 ◽  
Author(s):  
Laurent Dubreuil
Keyword(s):  
The Political ◽  
Second Moment ◽  
The Arts

Laurent Dubreuil provocatively proposes an extremist rethinking of the limits of politics – toward a break from politics, the political and policies. Rather than yet another re-articulation, he calls for a refusal of politics, suggesting a form of apolitics that would make our lives more liveable. The first chapter situates the refusal of politics in relation to different contemporary theoretical attempts to renew politics, and makes the case for a greater rupture. The second moment takes up what is liveable in life by way of apolitical experience, in contrast to appropriations of the collective, including a discussion of the arts. Finally, Dubreuil draws up an incomplete inventory of means: forms of existence – often frail and fleeting – that make an exit toward atopia.

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