THE INFLUENCE OF SURFACE ENERGY ON THE INCOMMENSURATE SUPERSTRUCTURE FORMATION PROCESSES

Author(s):  
S. Sveleba ◽  
I. Katerynchuk ◽  
I. Kunyo ◽  
I. Karpa ◽  
Ya. Shmygelsky
Author(s):  
Michael W. Bench ◽  
Paul G. Kotula ◽  
C. Barry Carter

The growth of semiconductors, superconductors, metals, and other insulators has been investigated using alumina substrates in a variety of orientations. The surface state of the alumina (for example surface reconstruction and step nature) can be expected to affect the growth nature and quality of the epilayers. As such, the surface nature has been studied using a number of techniques including low energy electron diffraction (LEED), reflection electron microscopy (REM), transmission electron microscopy (TEM), molecular dynamics computer simulations, and also by theoretical surface energy calculations. In the (0001) orientation, the bulk alumina lattice can be thought of as a layered structure with A1-A1-O stacking. This gives three possible terminations of the bulk alumina lattice, with theoretical surface energy calculations suggesting that termination should occur between the Al layers. Thus, the lattice often has been described as being made up of layers of (Al-O-Al) unit stacking sequences. There is a 180° rotation in the surface symmetry of successive layers and a total of six layers are required to form the alumina unit cell.


Author(s):  
P. J. Goodhew

Cavity nucleation and growth at grain and phase boundaries is of concern because it can lead to failure during creep and can lead to embrittlement as a result of radiation damage. Two major types of cavity are usually distinguished: The term bubble is applied to a cavity which contains gas at a pressure which is at least sufficient to support the surface tension (2g/r for a spherical bubble of radius r and surface energy g). The term void is generally applied to any cavity which contains less gas than this, but is not necessarily empty of gas. A void would therefore tend to shrink in the absence of any imposed driving force for growth, whereas a bubble would be stable or would tend to grow. It is widely considered that cavity nucleation always requires the presence of one or more gas atoms. However since it is extremely difficult to prepare experimental materials with a gas impurity concentration lower than their eventual cavity concentration there is little to be gained by debating this point.


Author(s):  
Eva Walther ◽  
Claudia Trasselli

Abstract. Two experiments tested the hypothesis that self-evaluation can serve as a source of interpersonal attitudes. In the first study, self-evaluation was manipulated by means of false feedback. A subsequent learning phase demonstrated that the co-occurrence of the self with another individual influenced the evaluation of this previously neutral target. Whereas evaluative self-target similarity increased under conditions of negative self-evaluation, an opposite effect emerged in the positive self-evaluation group. A second study replicated these findings and showed that the difference between positive and negative self-evaluation conditions disappeared when a load manipulation was applied. The implications of self-evaluation for attitude formation processes are discussed.


2019 ◽  
Vol 35 (4) ◽  
pp. 485-496
Author(s):  
S. RAJKUMAR ◽  
◽  
R. JOSEPH BENSINGH ◽  
M. ABDUL KADER ◽  
SANJAY K NAYAK ◽  
...  

2014 ◽  
Vol 2 (1) ◽  
pp. 8
Author(s):  
Debbie MacLellan ◽  
Jacqui Gingras ◽  
Daphne Lordly ◽  
Jennifer Brady

This paper explores beginning dietetic practitioners’ perspectives on the process of becoming dietetics professionals through the use of vignettes to illuminate the complex process of professional socialization.  Embedded in these vignettes are three themes related to the socialization process that occurs in the early years of dietetic practice: congruence, resilience, and relationships.  Our findings indicate that new dietitians struggle to develop their dietitian identity.  They feel unprepared for the relational and practice realities of the workplace and find the transition from dietetic intern to dietitian challenging.  They seek many ways to cope including seeking support from others and planning for the future but some consider leaving the profession.  It is important to understand the professional socialization and identity formation processes that occur during the early years of practice to ensure that dietitians feel prepared and supported as they begin their careers.


TAPPI Journal ◽  
2015 ◽  
Vol 14 (9) ◽  
pp. 565-576 ◽  
Author(s):  
YUCHENG PENG ◽  
DOUGLAS J. GARDNER

Understanding the surface properties of cellulose materials is important for proper commercial applications. The effect of particle size, particle morphology, and hydroxyl number on the surface energy of three microcrystalline cellulose (MCC) preparations and one nanofibrillated cellulose (NFC) preparation were investigated using inverse gas chromatography at column temperatures ranging from 30ºC to 60ºC. The mean particle sizes for the three MCC samples and the NFC sample were 120.1, 62.3, 13.9, and 9.3 μm. The corresponding dispersion components of surface energy at 30°C were 55.7 ± 0.1, 59.7 ± 1.3, 71.7 ± 1.0, and 57.4 ± 0.3 mJ/m2. MCC samples are agglomerates of small individual cellulose particles. The different particle sizes and morphologies of the three MCC samples resulted in various hydroxyl numbers, which in turn affected their dispersion component of surface energy. Cellulose samples exhibiting a higher hydroxyl number have a higher dispersion component of surface energy. The dispersion component of surface energy of all the cellulose samples decreased linearly with increasing temperature. MCC samples with larger agglomerates had a lower temperature coefficient of dispersion component of surface energy.


TAPPI Journal ◽  
2010 ◽  
Vol 9 (5) ◽  
pp. 29-35 ◽  
Author(s):  
PAULINE SKILLINGTON ◽  
YOLANDE R. SCHOEMAN ◽  
VALESKA CLOETE ◽  
PATRICE C. HARTMANN

Blocking is undesired adhesion between two surfaces when subjected to pressure and temperature constraints. Blocking between two coated paperboards in contact with each other may be caused by inter-diffusion, adsorption, or electrostatic forces occurring between the respective coating surfaces. These interactions are influenced by factors such as the temperature, pressure, surface roughness, and surface energy. Blocking potentially can be reduced by adjusting these factors, or by using antiblocking additives such as talc, amorphous silica, fatty acid amides, or polymeric waxes. We developed a method of quantifying blocking using a rheometer. Coated surfaces were put in contact with each other with controlled pressure and temperature for a definite period. We then measured the work necessary to pull the two surfaces apart. This was a reproducible way to accurately quantify blocking. The method was applied to determine the effect external factors have on the blocking tendency of coated paperboards, i.e., antiblocking additive concentration, film thickness, temperature, and humidity.


2013 ◽  
Vol 51 (10) ◽  
pp. 735-741
Author(s):  
Dong-Yong Kim ◽  
Eun-Wook Jeong ◽  
Kwun Nam Hui ◽  
Youngson Choe ◽  
Jung-Ho Han ◽  
...  

2010 ◽  
Vol 3 (1) ◽  
pp. 1-30 ◽  
Author(s):  
Heike Baeskow

For many decades there has been a consensus among linguists of various schools that derivational suffixes function not only to determine the word-class of the complex expressions they form, but also convey semantic information. The aspect of suffix-inherent meaning is ignored by representatives of a relatively new theoretical direction – Neo-Construction Grammar – who consider derivational suffixes to be either purely functional elements of the grammar or meaningless phonological realizations of abstract grammatical morphemes. The latter view is maintained by adherents of Distributed Morphology, who at the same time emphasize the importance of conceptual knowledge for derivational processes without attempting to define this aspect. The purpose of this study is first of all to provide support for the long-standing assumption that suffixes are inherently meaningful. The focus of interest is on the suffixes -ship, -dom and -hood. Data from Old English and Modern English (including neologisms) will show that these suffixes have developed rich arrays of meaning which cannot be structurally derived. Moreover, since conceptual knowledge is indeed an important factor for word-formation processes, a concrete, theory-independent model for the representation of the synchronically observable meaning components associated with -ship, -dom and -hood will be proposed.


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