scholarly journals On the role of actuation for the control of streaky structures in boundary layers

2019 ◽  
Vol 883 ◽  
Author(s):  
Kenzo Sasaki ◽  
Pierluigi Morra ◽  
André V. G. Cavalieri ◽  
Ardeshir Hanifi ◽  
Dan S. Henningson
Keyword(s):  
Boundary Layers ◽  
Streaky Structures ◽  
Image Position

The role of differential phase contrast in electron microscopy

1978 ◽  
Vol 36 (1) ◽  
pp. 176-177
Author(s):  
E.M. Waddell ◽  
J.N. Chapman ◽  
R.P. Ferrier
Keyword(s):  
Phase Contrast ◽  
Practical Method ◽  
Position Vector ◽  
Differential Phase ◽  
Pure Phase ◽  
Differential Phase Contrast ◽  
The Difference ◽  
Image Position ◽  
First Moment

Dekkers and de Lang (1977) have discussed a practical method of realising differential phase contrast in a STEM. The method involves taking the difference signal from two semi-circular detectors placed symmetrically about the optic axis and subtending the same angle (2α) at the specimen as that of the cone of illumination. Such a system, or an obvious generalisation of it, namely a quadrant detector, has the characteristic of responding to the gradient of the phase of the specimen transmittance. In this paper we shall compare the performance of this type of system with that of a first moment detector (Waddell et al.1977).For a first moment detector the response function R(k) is of the form R(k) = ck where c is a constant, k is a position vector in the detector plane and the vector nature of R(k)indicates that two signals are produced. This type of system would produce an image signal given bywhere the specimen transmittance is given by a (r) exp (iϕ (r), r is a position vector in object space, ro the position of the probe, ⊛ represents a convolution integral and it has been assumed that we have a coherent probe, with a complex disturbance of the form b(r-ro) exp (iζ (r-ro)). Thus the image signal for a pure phase object imaged in a STEM using a first moment detector is b2 ⊛ ▽ø. Note that this puts no restrictions on the magnitude of the variation of the phase function, but does assume an infinite detector.

scholarly journals Role of oligomer structures in the surface chemistry of amidinate metal complexes used for atomic layer deposition of thin films

2019 ◽  
Vol 35 (7) ◽  
pp. 720-731 ◽  
Author(s):  
Jonathan Guerrero-Sánchez ◽  
Bo Chen ◽  
Noboru Takeuchi ◽  
Francisco Zaera
Keyword(s):  
Thin Films ◽  
Atomic Layer Deposition ◽  
Surface Chemistry ◽  
Metal Complexes ◽  
Atomic Layer ◽  
Layer Deposition ◽  
Image Position

Abstract

scholarly journals NUMERICAL MODELING OF A TURBULENT BOTTOM BOUNDARY LAYER UNDER SOLITARY WAVES ON A SMOOTH SURFACE

2018 ◽  
pp. 26
Author(s):  
Ahmad Sana ◽  
Hitoshi Tanaka
Keyword(s):  
Boundary Layer ◽  
Boundary Layers ◽  
Solitary Waves ◽  
Bottom Boundary Layer ◽  
Stream Velocity ◽  
Bottom Boundary ◽  
Sediment Movement ◽  
Bottom Boundary Layers ◽  
Turbulent Models

A number of studies on bottom boundary layers under sinusoidal and cnoidal waves were carried out in the past owing to the role of bottom shear stress on coastal sediment movement. In recent years, the bottom boundary layers under long waves have attracted considerable attention due to the occurrence of huge tsunamis and corresponding sediment movement. In the present study two-equation turbulent models proposed by Menter(1994) have been applied to a bottom boundary layer under solitary waves. A comparison has been made for cross-stream velocity profile and other turbulence properties in x-direction.

scholarly journals The Role of Gravity in the Evolution of the Concentration Field in the Electrochemical Membrane Cell

Entropy ◽  
2020 ◽  
Vol 22 (6) ◽  
pp. 680 ◽  
Author(s):  
Kornelia M. Batko ◽  
Andrzej Ślęzak ◽  
Wioletta M. Bajdur
Keyword(s):  
Boundary Layers ◽  
Concentration Polarization ◽  
Concentration Field ◽  
Membrane System ◽  
Volume Transport ◽  
Cellulose Acetate Membrane ◽  
Concentration Boundary ◽  
Concentration Boundary Layers ◽  
Mechanical Stirring

The subject of the study was the osmotic volume transport of aqueous CuSO4 and/or ethanol solutions through a selective cellulose acetate membrane (Nephrophan). The effect of concentration of solution components, concentration polarization of solutions and configuration of the membrane system on the value of the volume osmotic flux ( J v i r ) in a single-membrane system in which the polymer membrane located in the horizontal plane was examined. The investigations were carried out under mechanical stirring conditions of the solutions and after it was turned off. Based on the obtained measurement results J v i r , the effects of concentration polarization, convection polarization, asymmetry and amplification of the volume osmotic flux and the thickness of the concentration boundary layers were calculated. Osmotic entropy production was also calculated for solution homogeneity and concentration polarization conditions. Using the thickness of the concentration boundary layers, critical values of the Rayleigh concentration number ( R C r ), i.e., the switch, were estimated between two states: convective (with higher J v i r ) and non-convective (with lower J v i r ). The operation of this switch indicates the regulatory role of earthly gravity in relation to membrane transport.

An extension of a theorem of Kulakoff

1938 ◽  
Vol 34 (3) ◽  
pp. 316-320
Author(s):  
T. E. Easterfield
Keyword(s):  
Finite Order ◽  
Dihedral Group ◽  
Mixed Group ◽  
Quaternion Group ◽  
Sylow Subgroups ◽  
Cyclic Groups ◽  
Image Position

It has been shown by Kulakoff that if G is a group, not cyclic, of order pl, p being an odd prime, the number of subgroups of G of order pk, for 0 < k < l, is congruent to 1 + p (mod p2); and by Hall that if G is any group of finite order whose Sylow subgroups of G of order pk, p being odd, are not cyclic, then, for 0 < k < l, the number of subgroups of G of order pk is congruent to 1 + p (mod p2). No results were given for the case p = 2. In the present paper it is shown that analogous results hold for the case p = 2, but that the role of the cyclic groups is played by groups of four exceptional types: the cyclic groups themselves, and three non-Abelian types. These groups are defined as follows:(1) The dihedral group, of order 2k, generated by A and B, where(2) The quaternion group, of order 2k, generated by A and B, where(3) The "mixed" group, of order 2k, generated by A and B, where

The role of sunshine in suicide: an explanatory model for the suicide peak in spring

2011 ◽  
Vol 26 (S2) ◽  
pp. 1652-1652
Author(s):  
B. Vyssoki ◽  
G. Sonneck ◽  
N. Praschak-Rieder ◽  
S. Kasper ◽  
M. Willeit ◽  
...  
Keyword(s):  
Statistical Analysis ◽  
Suicidal Behavior ◽  
Seasonal Pattern ◽  
Pearson Correlation ◽  
Central Institute ◽  
Sunshine Hours ◽  
Correlation Tests ◽  
Vulnerable Subjects ◽  
Image Position

IntroductionIt is known from previous studies that suicide follows a seasonal pattern with a peak in spring.ObjectivesAnalyze whether suicidal behavior is associated with the increase in the duration of sunshine in spring.AimsTo investigate the effect of number of sunshine hours per month on suicide rates in Austria between 1996–2006.MethodsSuicide data, differentiated by month of suicide, gender, and method of suicide (violent vs. non-violent methods), were provided by Statistics Austria. Data on the average number of sunshine hours per month were provided by the Austrian Central Institute for Meteorology. For statistical analysis ANOVA tests and Pearson correlation tests were used.ResultsSuicide frequencies were highest between March and May, lowest between November and January (df = 11, F = 5.2, p < .0001). The average number of sunshine hours per month was significantly correlated with the number of suicides among both genders r = .43 (p < .0001), violent methods (r = .48; p < .0001) but not with nonviolent methods (r = .03; p = .707).ConclusionsLight, possibly through interaction with melatonin, norepinephrine and serotonin, may improve motivation and drive first while mood improves at a later point in time. Thereby, a rapid increase in sunshine in spring might increase suicidal tendencies in vulnerable subjects.Fig. 1[Suicides and sunshine hours in Austria,1996-2006]

The role of personality and trait affectivity on delusional ideation

2017 ◽  
Vol 41 (S1) ◽  
pp. S747-S748
Author(s):  
M. Tonna ◽  
F. Paglia ◽  
R. Ottoni ◽  
P. Ossola ◽  
C. De Panfilis ◽  
...  
Keyword(s):  
Structured Interview ◽  
Dimensional Structure ◽  
Italian Version ◽  
Pathological Narcissism ◽  
Delusional Ideation ◽  
Competing Interest ◽  
Image Position ◽  
Personality Features ◽  
Trait Affectivity

ObjectiveThe relationship between personality and delusional ideation in still debated. The present study was aimed to evaluate the role of personality features and trait affectivity on the severity of delusional beliefs, through the lens of a dimensional approach. In fact, robust evidence suggests that delusional experience presents a dimensional structure rather than an all-or-nothing fashion with a severity gradient of delusional beliefs from general population to full-blown delusional disorder (DD).MethodForty-nine inpatients affected by DD and 42 non-delusional outpatients were administered the structured interview for DSM-IV Personality Disorders, the Pathological Narcissism Inventory–Italian Version, the Positive and Negative Affect Schedule and the Peters et al. 33–Italian version.ResultsSeverity of delusional ideation was positively related to “hiding the self” (HS) domain of narcissistic vulnerability and to paranoid traits and negatively related to “positive affect” (PA). Paranoid traits and HS significantly interacted in influencing delusional dimension severity (Fig. 1). Low PA represents a trait affectivity of sadness and lethargy whereas HS is closely related to the experience of shame. We speculate that lower levels of PA and higher levels of HS may grasp the “asthenic” pole of Kretschmer's “sensitive character”.ConclusionThe study findings suggest that the severity of delusional ideation depends, at least in part, on a complex interplay between specific affective and paranoid dispositions within personality. Delusion may constitute the superficial shell, which develops from and cover inner affective vulnerabilities of personality.Fig. 1Disclosure of interestThe authors have not supplied their declaration of competing interest.

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