Relative translations of adjacent crystals in twin boundaries

1984 ◽  
Vol 42 ◽  
pp. 590-591
Author(s):  
R. Pérez
Keyword(s):  
Experimental Evidence ◽  
Twin Boundary ◽  
Mirror Symmetry ◽  
Experimental Results ◽  
The Other ◽  
Atomic Model ◽  
Translation Vector ◽  
Twin Boundaries ◽  
The Past ◽  
Theoretical Simulations

Theoretical simulations of twin boundary contrast carried out in the past have shown that a relative translation of one crystal with respect to the other may exist. The first method proposed in the literature to determine this translation was given by Pond et. al and Pond This technique has been independently developed by Marukawa, who gave experimental evidence supporting an atomic model of twin boundary on [211] in which the adjacent crystals have mirror symmetry across the twin boundary as opposed to a structure where the two crystals are relatively translated parallel. However, this conclusion has been criticized in the literature. In this communication some recent results obtained in Cu are discussed. These experimental results suggest in one case that the adjacent crystals in a twin boundary have mirror symmetry across the boundary. However, in other cases, the presence of a body translation vector is clearly indicated. Experimental images of twin boundaries have been obtained from wedge shaped specimens of Cu.

The Morphology of Grain Boundary Interactions with Twins in YBa2Cu3O7−δ

1993 ◽  
Vol 319 ◽  
Author(s):  
Jenn-Yue Wang ◽  
A. H. King
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Twin Boundary ◽  
Interfacial Energy ◽  
Coincidence Site Lattice ◽  
The Other ◽  
Twin Boundaries ◽  
Site Lattice ◽  
Dislocation Arrays

AbstractVarious morphologies are observed where twins meet grain boundaries in YBa2Cu3O7−δ. Twins may be “correlated” at the boundary (i.e. twin boundaries from one grain may meet a twin boundary from the other grain in a quadruple junction) and the twins may be narrowed or “constricted” at the boundary. These effects are determined by the interfacial energy. We estimate the energy of the various interfaces by determining the dislocation arrays they contain, using the constrained coincidence site lattice (CCSL) model and Bollmann's O2-lattice formalism. Our approach indicates that there are significant changes in the energy of the interfaces and is thus able to explain the variety of observed morphologies.

Twinning dislocations and structural transition of twin boundary in YBa2Cu3O7-δ

1992 ◽  
Vol 50 (1) ◽  
pp. 238-239
Author(s):  
Yimei Zhu ◽  
M. Suenaga
Keyword(s):  
Diffraction Analysis ◽  
Twin Boundary ◽  
Structural Transition ◽  
Intrinsic Property ◽  
The Other ◽  
Twin Boundaries ◽  
Fringe Contrast ◽  
Boundary Formation ◽  
Contrast Analysis ◽  
Kinetics Of

HREM studies suggest that there are two types of twin boundaries in YBa2Cu307-δ. one with a lattice translation (∼d110) along the boundary for fully oxygenated samples, and the other without a lattice translation for oxygen-deficient ones. Originally, the displacement was attributed to observational phenomena caused by misalignment of the crystal. However, diffraction analysis and twin boundary fringe contrast analysis showed that the lattice translation at the boundary is an intrinsic property of the twin boundary in fully oxygenated YBa2(Cu0.98 M0.02)3O7-δ (M = Cu, Zn, and Ni, and δ∽0.0). To further understand the kinetics of twin boundary formation, we present additional observations on twinning dislocation and structural transition of the twin boundaries.

scholarly journals Employing opposite ratings users in a new approach to collaborative filtering

2022 ◽  
Vol 25 (1) ◽  
pp. 450
Author(s):  
Abdellah El Fazziki ◽  
Yasser El Madani El Alami ◽  
Jalil Elhassouni ◽  
Ouafae El Aissaoui ◽  
Mohammed Benbrahim
Keyword(s):  
Collaborative Filtering ◽  
Basic Assumption ◽  
Recommendation System ◽  
Experimental Results ◽  
The Other ◽  
Unusual Behavior ◽  
New Approach ◽  
The Real ◽  
The Past ◽  
The One

Over the past few decades, various recommendation system paradigms have been developed for both research and industrial purposes to satisfy the needs and preferences of users when they deal with enormous data. The collaborative filtering (CF) is one of the most popular recommendation techniques, although it is still immature and suffers from some difficulties such asparsity, gray sheep and scalability impeding recommendation quality. Therefore, we propose a new CF approach to deal with the gray sheep problem in order to improve the predictions accuracy. To realize this goal, our solution aims to infer new users from real ones existing in datasets. This transformation allows for creating users with opposite preferences to the real ones. On the one hand, our approach permits to amplify the number of neighbors, especially in the case of users who have unusual behavior (gray sheep). On the other hand, it facilitates building a dense similar neighborhood. The basic assumption behind this is that if user X is not similar to user Y, then the imaginary user ¬X is similar to the user Y. The performance of our approach was evaluated using two datasets, MovieLens and FilmTrust. Experimental results have shown that our approach surpasses many traditional recommendation approaches.

Immunoferritin localization of intracellular antigens in positively stained frozen sections

1978 ◽  
Vol 36 (2) ◽  
pp. 168-169
Author(s):  
K. T. Tokuyasu
Keyword(s):  
Surface Tension ◽  
Water Surface ◽  
Thin Layers ◽  
The Other ◽  
Positive Staining ◽  
Frozen Sections ◽  
The Past ◽  
Ultrathin Frozen Sections ◽  
Definition Of

During the past investigations of immunoferritin localization of intracellular antigens in ultrathin frozen sections, we found that the degree of negative staining required to delineate u1trastructural details was often too dense for the recognition of ferritin particles. The quality of positive staining of ultrathin frozen sections, on the other hand, has generally been far inferior to that attainable in conventional plastic embedded sections, particularly in the definition of membranes. As we discussed before, a main cause of this difficulty seemed to be the vulnerability of frozen sections to the damaging effects of air-water surface tension at the time of drying of the sections.Indeed, we found that the quality of positive staining is greatly improved when positively stained frozen sections are protected against the effects of surface tension by embedding them in thin layers of mechanically stable materials at the time of drying (unpublished).

Measurement of the Displacement Across a Coincidence Grain Boundary

1977 ◽  
Vol 35 ◽  
pp. 124-125
Author(s):  
J. W. Matthews ◽  
W. M. Stobbs
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Stacking Fault ◽  
The Other ◽  
Measuring Technique ◽  
High Angle ◽  
Twin Boundaries ◽  
Rigid Displacement ◽  
Cubic Crystals ◽  
Lattice Displacement

Many high-angle grain boundaries in cubic crystals are thought to be either coincidence boundaries (1) or coincidence boundaries to which grain boundary dislocations have been added (1,2). Calculations of the arrangement of atoms inside coincidence boundaries suggest that the coincidence lattice will usually not be continuous across a coincidence boundary (3). There will usually be a rigid displacement of the lattice on one side of the boundary relative to that on the other. This displacement gives rise to a stacking fault in the coincidence lattice.Recently, Pond (4) and Smith (5) have measured the lattice displacement at coincidence boundaries in aluminum. We have developed (6) an alternative to the measuring technique used by them, and have used it to find two of the three components of the displacement at {112} lateral twin boundaries in gold. This paper describes our method and presents a brief account of the results we have obtained.

Applications of Through-Focus Dark Field Image Shifts to Phase Identification

1975 ◽  
Vol 33 ◽  
pp. 178-179
Author(s):  
Prakash Rao
Keyword(s):  
Dark Field Image ◽  
Thin Foil ◽  
Dark Field ◽  
The Other ◽  
Stereo Image ◽  
Phase Identification ◽  
The Past ◽  
Field Electron Microscopy ◽  
Dark Field Electron ◽  
Recent Extension

Image shifts in out-of-focus dark field images have been used in the past to determine, for example, epitaxial relationships in thin films. A recent extension of the use of dark field image shifts has been to out-of-focus images in conjunction with stereoviewing to produce an artificial stereo image effect. The technique, called through-focus dark field electron microscopy or 2-1/2D microscopy, basically involves obtaining two beam-tilted dark field images such that one is slightly over-focus and the other slightly under-focus, followed by examination of the two images through a conventional stereoviewer. The elevation differences so produced are usually unrelated to object positions in the thin foil and no specimen tilting is required.In order to produce this artificial stereo effect for the purpose of phase separation and identification, it is first necessary to select a region of the diffraction pattern containing more than just one discrete spot, with the objective aperture.

Correlational Methods for Analysis of Dance Movements

2011 ◽  
Vol 29 (supplement) ◽  
pp. 283-304 ◽  
Author(s):  
Timothy R. Brick ◽  
Steven M. Boker
Keyword(s):  
Motion Capture ◽  
Mirror Symmetry ◽  
Cross Correlation ◽  
The Other ◽  
Free Form ◽  
Motion Capture Data ◽  
Complex Interactions ◽  
Dance Movements ◽  
Time Lagged ◽  
Insight Into

Among the qualities that distinguish dance from other types of human behavior and interaction are the creation and breaking of synchrony and symmetry. The combination of symmetry and synchrony can provide complex interactions. For example, two dancers might make very different movements, slowing each time the other sped up: a mirror symmetry of velocity. Examining patterns of synchrony and symmetry can provide insight into both the artistic nature of the dance, and the nature of the perceptions and responses of the dancers. However, such complex symmetries are often difficult to quantify. This paper presents three methods – Generalized Local Linear Approximation, Time-lagged Autocorrelation, and Windowed Cross-correlation – for the exploration of symmetry and synchrony in motion-capture data as is it applied to dance and illustrate these with examples from a study of free-form dance. Combined, these techniques provide powerful tools for the examination of the structure of symmetry and synchrony in dance.

‘Newness which never perishes’? Schoenberg’s ambivalent reception of Haydn

2010 ◽  
Vol 51 (1-2) ◽  
pp. 215-224
Author(s):  
Alexander Carpenter
Keyword(s):  
The Other ◽  
Major Influence ◽  
Musical Style ◽  
The Past ◽  
Other Hand ◽  
The Future ◽  
Music Tradition

This paper explores Arnold Schoenberg’s curious ambivalence towards Haydn. Schoenberg recognized Haydn as an important figure in the German serious music tradition, but never closely examined or clearly articulated Haydn’s influence and import on his own musical style and ethos, as he did with many other major composers. This paper argues that Schoenberg failed to explicitly recognize Haydn as a major influence because he saw Haydn as he saw himself, namely as a somewhat ungainly, paradoxical figure, with one foot in the past and one in the future. In his voluminous writings on music, Haydn is mentioned by Schoenberg far less frequently than Bach, Mozart, or Beethoven, and his music appears rarely as examples in Schoenberg’s theoretical texts. When Schoenberg does talk about Haydn’s music, he invokes — with tacit negativity — its accessibility, counterpoising it with more recondite music, such as Beethoven’s, or his own. On the other hand, Schoenberg also praises Haydn for his complex, irregular phrasing and harmonic exploration. Haydn thus appears in Schoenberg’s writings as a figure invested with ambivalence: a key member of the First Viennese triumvirate, but at the same time he is curiously phantasmal, and is accorded a peripheral place in Schoenberg’s version of the canon and his own musical genealogy.

Economic Performance and Public Finance in Kenya, 1960-2010

2018 ◽  
Vol 47 (2) ◽  
Author(s):  
Kempe Ronald Hope
Keyword(s):  
Public Finance ◽  
Economic Performance ◽  
Emerging Economy ◽  
The Other ◽  
Government Investment ◽  
The Past ◽  
Other Hand ◽  
Private Savings ◽  
Per Capita ◽  
Real Growth

Countries with positive per capita real growth are characterised by positive national savings—including government savings, increases in government investment, and strong increases in private savings and investment. On the other hand, countries with negative per capita real growth tend to be characterised by declines in savings and investment. During the past several decades, Kenya’s emerging economy has undergone many changes and economic performance has been epitomised by periods of stability, decline, or unevenness. This article discusses and analyses the record of economic performance and public finance in Kenya during the period 1960‒2010, as well as policies and other factors that have influenced that record in this emerging economy. 

Vom Forst zum Wald. Entwicklungstendenzen im naturnahen Waldbau | From a Production-Oriented Forest to a Multipurpose Forest. New Trends in Near-Natural Silviculture

1999 ◽  
Vol 150 (12) ◽  
pp. 484-488 ◽  
Author(s):  
Wolf Hockenjos
Keyword(s):  
Forest Management ◽  
Timber Harvest ◽  
Timber Harvesting ◽  
Natural Forest ◽  
The Other ◽  
Private Forest ◽  
Wide Spread ◽  
Great Demand ◽  
The Past ◽  
Forest Enterprises

Concepts of near-natural forestry are in great demand these days. Most German forest administrations and private forest enterprises attach great importance to being as «near-natural» as possible. This should allow them to make the most of biological rationalisation. The concept of near-natural forestry is widely accepted, especially by conservationists. However, it is much too early to analyse how successful near-natural forestry has been to date, and therefore to decide whether an era of genuine near-natural forest management has really begun. Despite wide-spread recognition, near-natural forestry is jeopardised by mechanised timber harvesting, and particularly by the large-timber harvester. The risk is that machines, which are currently just one element of the timber harvest will gain in importance and gradually become the decisive element. The forest would then be forced to meet the needs of machinery, not the other way round. Forests would consequently become so inhospitable that they would bear no resemblance to the sylvan image conjured up by potential visitors. This could mean taking a huge step backwards: from a near-natural forest to a forest dominated by machinery. The model of multipurpose forest management would become less viable, and the forest would become divided into areas for production, and separate areas for recreation and ecology. The consequences of technical intervention need to be carefully considered, if near-natural forestry is not to become a thing of the past.

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