scholarly journals Elimination of Nyquist ghosting caused by read-out to phase-encode gradient cross-terms in EPI

2002 ◽  
Vol 47 (2) ◽  
pp. 337-343 ◽  
Author(s):  
Stuart M. Grieve ◽  
Andrew M. Blamire ◽  
Peter Styles
Keyword(s):  
Cross Terms ◽  
Phase Encode Gradient ◽  
Phase Encode

A fast spectroscopic imaging method using a blipped phase encode gradient

1989 ◽  
Vol 12 (3) ◽  
pp. 306-315 ◽  
Author(s):  
Peter Webb ◽  
Daniel Spielman ◽  
Albert Macovski
Keyword(s):  
Spectroscopic Imaging ◽  
Imaging Method ◽  
Phase Encode Gradient ◽  
Phase Encode

A Method to Suppress Cross-Terms of Wigner-Ville Distribution Using ASTFT Spectrum

2011 ◽  
Vol 30 (10) ◽  
pp. 2299-2302 ◽  
Author(s):  
Fa-bin Cheng ◽  
Bao-ping Tang ◽  
You-ming Zhong
Keyword(s):  
Cross Terms

Additive-multiplicative description of extrathermodynamic relations: Application to solvent effect

1990 ◽  
Vol 55 (3) ◽  
pp. 634-643 ◽  
Author(s):  
Oldřich Pytela
Keyword(s):  
Solvent Effect ◽  
Additive Model ◽  
Multiplicative Model ◽  
Data Matrix ◽  
Statistical Parameters ◽  
Model Application ◽  
Mutual Correlation ◽  
Linear Free Energy ◽  
Cross Terms ◽  
Energy Relationships

The paper is focused on evaluation of significance of the additive-multiplicative model of extrathermodynamic relations (linear free energy relationships) as compared with the additive model. Application of the method of conjugated deviations to a data matrix describing manifestations of solvent effects in 367 processes in solutions (6 334 data) has shown that introduction of cross-terms into the additive model is statistically significant for a model with two and particularly three parameters. At the same time the calculation has provided a new set of statistical parameters for description of solvent effect with application of the additive-multiplicative model. Compared with an analogous set designated for the additive model, the new parameters show a lower mutual correlation, retaining the same nature of the properties described, i.e. polarity-acidity (PAC parameter), polarity-basicity (PBC), and polarity-polarizability (PPC).

Simulation of Intrinsic Diffusion in Multicomponent Multiphase Systems

1998 ◽  
Vol 527 ◽  
Author(s):  
M. Hunkel ◽  
D. Bergner
Keyword(s):  
Single Phase ◽  
Diffusion Flux ◽  
Wind Effect ◽  
Concentration Profiles ◽  
Intrinsic Diffusion ◽  
Cross Terms ◽  
Multiphase Systems ◽  
Random Alloy ◽  
Simulation Results ◽  
Vacancy Flux

ABSTRACTA simulation model for intrinsic diffusion of multicomponent multiphase systems is presented. The model is not restricted onto a certain number of components or phases. For simplicity, Manning's random alloy model with vanishing vacancy wind effect is used. Then the cross terms of the diffusion flux can be neglected. The simulation routine uses equations for the fluxes, the equation of continuity and an equation for the change of the thickness of volume elements due to the vacancy flux. With this model diffusions paths, concentration profiles, fluxes of the components as well as marker positions can be calculated. The shift of interfaces and the growth of new phases can also be determined. The simulation results were compared with experimental data of the Cu-Fe-Ni system. Diffusion was studied in single-phase areas and across interfaces.

Theoretical Condition for the Cxy=Cyx Relation in Fluid Film Journal Bearings

1989 ◽  
Vol 111 (3) ◽  
pp. 426-429 ◽  
Author(s):  
T. Kato ◽  
Y. Hori
Keyword(s):  
Reynolds Equation ◽  
Journal Bearing ◽  
Journal Bearings ◽  
Fluid Film ◽  
Finite Width ◽  
Damping Coefficients ◽  
Dynamic Coefficients ◽  
Cross Terms ◽  
Linear Damping ◽  
Theoretical Condition

A computer program for calculating dynamic coefficients of journal bearings is necessary in designing fluid film journal bearings and an accuracy of the program is sometimes checked by the relation that the cross terms of linear damping coefficients of journal bearings are equal to each other, namely “Cxy = Cyx”. However, the condition for this relation has not been clear. This paper shows that the relation “Cxy = Cyx” holds in any type of finite width journal bearing when these are calculated under the following condition: (I) The governing Reynolds equation is linear in pressure or regarded as linear in numerical calculations; (II) Film thickness is given by h = c (1 + κcosθ); and (III) Boundary condition is homogeneous such as p=0 or dp/dn=0, where n denotes a normal to the boundary.

Reply to the ‘Comment on “How to interpret Onsager cross terms in mixed ionic electronic conductors”’ by H.-I. Yoo, M. Martin, and J. Janek, Phys. Chem. Chem. Phys., 2015,7, DOI: 10.1039/C4CP05737F

2015 ◽  
Vol 17 (16) ◽  
pp. 11107-11108 ◽  
Author(s):  
I. Riess
Keyword(s):  
Chem Phys ◽  
Cross Terms ◽  
Mixed Ionic Electronic Conductors ◽  
Electronic Conductors ◽  
Phys Chem Chem Phys

The Onsager cross terms are re-examined. Two experiments are suggested to test which of two alternative explanations for these terms is valid.

ANALYSIS OF CAROTID ARTERIAL DOPPLER SIGNALS USING STFT AND WIGNER–VILLE DISTRIBUTION (WVD)

2009 ◽  
Vol 09 (01) ◽  
pp. 49-62
Author(s):  
MELLE SEDDIK AMINA ◽  
M. BEREKSI REGUIG FETHI
Keyword(s):  
Power Spectra ◽  
Doppler Imaging ◽  
Time Frequency ◽  
Ultrasound Frequency ◽  
Doppler Signals ◽  
Cross Terms ◽  
Noticeable Reduction ◽  
Doppler Power ◽  
Short Time

The study presented in this paper is concerned with the analysis of the ultrasound Doppler signal of the carotid arteries in the time-frequency domain using the short time Fourier transform (STFT) and the Wigner–Ville distribution (WVD). This study is carried out in order to investigate the behavior of the spectral broadening index (SBI) derived from spectra obtained using these methods. The variations in the shape of the Doppler power spectra as a function of time are presented in the form of sonograms in order to determine the degree of primitive carotid artery stenosis. The obtained results show a qualitative improvement in the appearance of the sonograms generated using the WVD over the STFT. However, despite this qualitative improvement the WVD suffers from some drawbacks: the presence of the cross terms which are primarily due to its quadratic nature. The application of the Choi–Williams distribution (CWD) in this analysis shows a noticeable reduction of these cross terms, improving therefore the quality of the sonograms. From these generated sonograms, the ultrasound frequency envelopes are extracted. The maximum and the mean frequencies in these envelopes are used to determine the SBI. The magnitude of the CWD-SBI is significantly greater than that of the STFT-SBI. In addition, there is a correlation between the SBIs obtained using the STFT and the CWD and the degree of severity of stenosis measured by 2D Doppler imaging.

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