Calculated<tex>$I-V$</tex>Characteristics and Their Critical Scaling of Ag/Bi2223 Tapes Based on Weak Link Path Model

2005 ◽  
Vol 15 (2) ◽  
pp. 2454-2457 ◽  
Author(s):  
K. Ogawa ◽  
K. Osamura
Author(s):  
J.-Y. Wang ◽  
Y. Zhu ◽  
A.H. King ◽  
M. Suenaga

One outstanding problem in YBa2Cu3O7−δ superconductors is the weak link behavior of grain boundaries, especially boundaries with a large-angle misorientation. Increasing evidence shows that lattice mismatch at the boundaries contributes to variations in oxygen and cation concentrations at the boundaries, while the strain field surrounding a dislocation core at the boundary suppresses the superconducting order parameter. Thus, understanding the structure of the grain boundary and the grain boundary dislocations (which describe the topology of the boundary) is essential in elucidating the superconducting characteristics of boundaries. Here, we discuss our study of the structure of a Σ5 grain boundary by transmission electron microscopy. The characterization of the structure of the boundary was based on the coincidence site lattice (CSL) model.Fig.l shows two-beam images of the grain boundary near the projection. An array of grain boundary dislocations, with spacings of about 30nm, is clearly visible in Fig. 1(a), but invisible in Fig. 1(b).


Author(s):  
Z. L. Wang ◽  
C. L. Briant ◽  
J. DeLuca ◽  
A. Goyal ◽  
D. M. Kroeger ◽  
...  

Recent studies have shown that spray-pyrolyzed films of the Tl-1223 compound (TlxBa2Ca2Cu3Oy, with 0.7 < × < 0.95) on polycrystalline yttrium stabilized zirconia substrates can be prepared which have critical current density Jc near 105 A/cm2 at 77 K, in zero field. The films are polycrystalline, have excellent c-axis alignment, and show little evidence of weak-link behavior. Transmission electron microscopy (TEM) studies have shown that most grain boundaries have small misorientation angles. It has been found that the films have a nigh degree of local texture indicative of colonies of similarly oriented grains. It is believed that inter-colony conduction is enhanced by a percolative network of small angle boundaries at colony interfaces. It has also been found that Jc is increased by a factor of 4 - 5 after the films were annealed at 600 °C in oxygen. This study is thus carried out to determine the effect on grain boundary chemistry of the heat treatment.


GeroPsych ◽  
2017 ◽  
Vol 30 (2) ◽  
pp. 49-59 ◽  
Author(s):  
Anna L. Seidler ◽  
Julia K. Wolff

Abstract. Background: Previous studies point to a potential relationship between self-perceptions of aging (SPA) and cognitive performance. However, most of these studies are limited by their experimental design. Previous longitudinal studies looked solely at memory as an outcome variable without examining the directionality of effects. The present study examines the direction of effects between two domains of SPA (personal growth and physical losses) and processing speed (PS). Methods: The sample consists of 8,198 participants of the German Ageing Survey (DEAS), aged between 40 and 93 years. A cross-lagged path model was estimated to examine directions of relationships across 3 years via chi-squared difference tests for each domain of SPA. Results: In the unconstrained models, the effect of SPA domain personal growth in 2008 on PS in 2011 and vice versa were marginally significant. For SPA domain physical losses, the effect of SPA on PS was significant, whereas the other direction of the effect did not reach significance. However, the cross-lagged paths of both domains of SPA on PS and vice versa could be set equal without a significant loss of model fit. The resulting associations indicate a significant bidirectional relationship between both domains of SPA and PS. Discussion and conclusion: This study provides initial evidence that SPA can influence trajectories of cognitive decline and vice versa. The results emphasize the detrimental and beneficial effects that stereotypes can have on individuals and add further evidence to the theory of stereotype embodiment.


2020 ◽  
Vol 32 (4) ◽  
pp. 165-175 ◽  
Author(s):  
Leman Pınar Tosun ◽  
Ezgi Kaşdarma

Abstract. In the current study we examined a psychological mechanism linking Facebook use to depression. A survey was conducted with 319 undergraduates about their passive Facebook use, their frequency of making upward social comparisons on Facebook, the emotions evoked through these comparisons, and their levels of depression. Half of the participants were given questions about the Facebook comparisons they made with their close friends, while the other half were given questions about the Facebook comparisons they made with acquaintances. Analysis of the whole sample revealed that upward Facebook comparison elicited assimilative emotions (inspiration, optimism, and admiration) more than contrastive emotions did (envy and resentment). A path model was developed in which passive use of Facebook predicted the frequency of making upward social comparisons, and, in turn, the frequency of making upward Facebook comparisons predicted depression through two routes: one through contrastive emotions and other through assimilative emotions. The results suggested that the model fits the data. As expected, the frequency of upward Facebook comparisons was associated with the increases in frequency of both contrastive and assimilative emotions, and the associations of these two types of emotions with depression were in opposite directions: Depression increased as the frequency of contrastive emotions increased, and it decreased as the frequency of assimilative emotions increased. The strength of the latter aforementioned association was stronger when the comparison targets were acquaintances rather than close friends.


2009 ◽  
Author(s):  
Kevin C. Stagl ◽  
Cameron Klein ◽  
Patrick J. Rosopa ◽  
Deborah DiazGranados ◽  
Eduardo Salas ◽  
...  
Keyword(s):  

1997 ◽  
Vol 473 ◽  
Author(s):  
J. A. Davis ◽  
J. D. Meindl

ABSTRACTOpportunities for Gigascale Integration (GSI) are governed by a hierarchy of physical limits. The levels of this hierarchy have been codified as: 1) fundamental, 2) material, 3) device, 4) circuit and 5) system. Many key limits at all levels of the hierarchy can be displayed in the power, P, versus delay, td, plane and the reciprocal length squared, L-2, versus response time, τ, plane. Power, P, is the average power transfer during a binary switching transition and delay, td, is the time required for the transition. Length, L, is the distance traversed by an interconnect that joins two nodes on a chip and response time, τ, characterizes the corresponding interconnect circuit. At the system level of the hierarchy, quantitative definition of both the P versus td and the L-2 versus τ displays requires an estimate of the complete stochastic wiring distribution of a chip.Based on Rent's Rule, a well known empirical relationship between the number of signal input/output terminals on a block of logic and the number of gate circuits with the block, a rigorous derivation of a new complete stochastic wire length distribution for an on-chip random logic network is described. This distribution is compared to actual data for modern microprocessors and to previously described distributions. A methodology for estimating the complete wire length distribution for future GSI products is proposed. The new distribution is then used to enhance the critical path model that determines the maximum clock frequency of a chip; to derive a preliminary power dissipation model for a random logic network; and, to define an optimal architecture of a multilevel interconnect network that minimizes overall chip size. In essence, a new complete stochastic wiring distribution provides a generic basis for maximizing the value obtained from a multilevel interconnect technology.


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