Deformed substructures in fine-grained tetragonal zirconia

Transmission electron microscopy (TEM) has been employed to examine the deformed microstructures of a high-purity tetragonal zirconia polycrystal containing 3mol% yttria. The TEM observations reveal that piled-up and tangled dislocations are developed within grains at a high stress, but such substructures do not appear at a lower stress, except for a small number of isolated dislocations. The stress-dependent deformed microstructures suggest that the dislocation substructures observed at a high stress are not due to any experimental artefacts. Applying a model proposed by Eshelby et al. to the observed pile-up dislocations, it can be estimated that a stress concentration of the order of 14-25 is generated around multiple-grain junctions during deformation.     

Ductile fracture mechanism in fine-grained magnesium alloy

The ductile fracture mechanism in a fine-grained magnesium alloy has been investigated by transmission electron microscopy-focused ion beam techniques. In coarse-grained or conventional magnesium alloys, twins form at the very beginning of the deformation process, and crack propagation occurs through the twin boundaries. However, in the alloy used in this study, subgrain structures were found instead of twins at the crack tip. Nanoscale twins formed subsequently owing to large stress in the crack propagation route. The fine-grained alloys showed high fracture toughness resulting from resistance to the twins at the beginning of the deformation.     

Learning fine-grained and category information in navigable real-world space

Spatial judgments are affected by both fine-grained and categorical knowledge. We investigated whether, and how, the two forms of knowledge are learned in real-world, navigable space, as well as the time course of learning each type of knowledge. Participants were Northwestern University undergraduates who estimated the locations of buildings and other landmarks on campus. The Northwestern campus is roughly divided into three regions whose borders are not easy to discern, either from a map or by navigation. Nevertheless, students often refer to these regions linguistically and use them when making housing decisions, choosing classes, and so forth. We found that knowledge of both the fine-grained configuration of locations and the regional distinctions increased with time. However, regional influences on judgments occurred later in students’ time on campus. Consequently, computed distances across the nonexistent border between north and south campus locations became more biased with time. The results have implications for understanding how spatial representations develop in navigable environments.     

The fine-grained metaphysics of artifactual and biological functional kinds

In this paper we consider the emerging position in metaphysics that artifact functions characterize real kinds of artifacts. We analyze how it can circumvent an objection by David Wiggins (Sameness and substance renewed, 2001, 87) and then argue that this position, in comparison to expert judgments, amounts to an interesting fine-grained metaphysics: taking artifact functions as (part of the) essences of artifacts leads to distinctions between principles of activity of artifacts that experts in technology have not yet made. We show, moreover, that our argument holds not only in the artifactual realm but also in biology: taking biological functions as (part of the) essences of organs leads to distinctions between principles of activity of organs that biological experts have not yet made. We run our argument on the basis of analyses of artifact and biological functions as developed in philosophy of technology and of biology, thus importing results obtained outside of metaphysics into the debate on ontological realism. In return, our argument shows that a position in metaphysics provides experts reason for trying to detect differences between principles of activities of artifacts and organs that have not been detected so far.     

A new rotational method in factor analysis

A new rotational method, particularly appropriate when a positive manifold can be assumed, is presented in theory and in computational detail. It is applied to a five-dimensional factorial matrix in which a simple configuration is known to exist. The new technique is much more efficient in yielding the simple configuration than are the methods formerly used. Landahl's transformations can be combined with this method to advantage.     

On the length scale of cyclic strain localization in fine-grained copper films

Fine-grained copper films on a flexible substrate were cyclically deformed under constant strain range control. It was found that cyclic dislocation plasticity through individual dislocation glide is still dominant at the submicrometer scale, while the ability of irreversible slip of dislocations gradually decreases and the damage was changed from extrusion-induced localization to cracking along grain boundary. Statistical evaluation of the mean spacing between slip bands and/or lines leads to a critical scale (～28 nm) below which dislocation-controlled cyclic strain localization would be shut down.     

Contributions of category and fine-grained information to location memory: When categories don't weigh in

Several studies have shown that people's memory for location can be influenced by categorical information. According to a model proposed by Huttenlocher, Hedges, and Duncan (1991), people estimate location by combining fine-grained item-level information in memory with category-level information. When the fine-grained information is inexact, category-level information is given greater weight, which leads to biased responses. We manipulated the distribution of locations presented in order to alter the usefulness of category information, and we manipulated background texture in order to alter accuracy of fine-grained memory. The distributional information reduced bias without altering overall accuracy of responding, whereas the background texture manipulation affected accuracy without changing bias. Our results suggest that category information may weigh in only when it is actively processed.     

Gradual improvement in fine-grained sensitivity to triadic gaze after 6 years of age

The current research compared the ability of adults and children to determine where another person is looking in shared visual space (triadic gaze). In Experiment 1, children (6-, 8-, 10-, and 14-year-olds) and adults viewed photographs of a model fixating a series of positions separated by 1.6° along the horizontal plane. The task was to indicate whether the model was looking to the left or right of one of three target positions (midline, 6.4° left, or 6.4° right). By 6 years of age, thresholds were quite small (M=1.94°) but were roughly twice as large as those of adults (M=1.05°). Thresholds decreased to adult-like levels around 10 years of age. All age groups showed the same pattern of higher sensitivity for central targets than peripheral targets and of misjudging gaze toward peripheral targets as farther from midline than it really was. In subsequent experiments, we evaluated possible reasons for the higher thresholds in 6- and 8-year-olds. In Experiment 2, the thresholds of 6-year-olds did not improve when the range of deviations from the target position that the model fixated covered a much wider range. In Experiment 3, 8-year-olds were less sensitive than adults to small shifts in eye position even though the task required only matching faces with the same eye position and not determining where the person was looking. These findings suggest that by 6 years of age, children are quite sensitive to triadic gaze, which may support inferences about others' interests and intentions. Subsequent improvements in sensitivity involve, at least in part, an increase in sensitivity to eye position.     

Shape, orientation, and apparent rotational motion

Apparent rotational motion was investigated in polygonal shapes ranging in rotational symmetry from random to self-identical under 180 degrees rotation. Observers adjusted the rate of alternation between two computer-displayed orientations of any given polygon to determine the point of breakdown of perceived rigid rotation between those two orientations. For asymmetric polygons, the minimum stimulus-onset asynchrony yielding apparent rigid rotation increased approximately linearly with orientational disparity, as anticipated on the basis of the extension of Korte's third law to rotational motion by Shepard and Judd. For nearly symmetric polygons, however, the critical time increased markedly as the disparities approached 180 degrees, owing to the availability of a shorter, nonrigid rotation in the opposite direction. The results demonstrate the existence of competing mental tendencies to preserve the rigid structure of an object and to traverse a minimum transformational path.     

Memory for pitch in congenital amusia: Beyond a fine-grained pitch discrimination problem

Congenital amusia is a disorder that affects the perception and production of music. While amusia has been associated with deficits in pitch discrimination, several reports suggest that memory deficits also play a role. The present study investigated short-term memory span for pitch-based and verbal information in 14 individuals with amusia and matched controls. Analogous adaptive-tracking procedures were used to generate tone and digit spans using stimuli that exceeded psychophysically measured pitch perception thresholds. Individuals with amusia had significantly smaller tone spans, whereas their digits spans were a similar size to those of controls. An automated operation span task was used to determine working memory capacity. Working memory deficits were seen in only a small subgroup of individuals with amusia. These findings support the existence of a pitch-specific component within short-term memory and suggest that congenital amusia is more than a disorder of fine-grained pitch discrimination.     

Relationship maintenance strategies of rotational workers and their partners

Although individuals who reside permanently in one location and work temporarily in another (i.e., rotational workers) represent a sizeable segment of the population, they are understudied in the empirical literature. Because rotational workers and their at-home partners have unique long-distance relationships due to frequent separations and reunions, they and their relationships should be examined. The primary aim of this study was to identify key factors associated with maintenance of romantic relationships between rotational workers and their at-home partners. Participants (N = 289) were rotational workers (n = 129) and at-home partners of workers (n = 160) who completed online surveys on individual, dyadic, and extra-dyadic relationship maintenance behaviors and relationship characteristics over the course of two working-reunion (roster) phases. Results indicated individual, dyadic, and extra-dyadic behaviors positively predicted perceived relationship quality among partners and workers. Among partners, generosity positively predicted relationship quality at the first reunion and second departure phases. All other individual, dyadic, and extra-dyadic relationship maintenance behaviors predicted relationship quality, regardless of the roster phase. Overall, results suggest the importance of relationship maintenance education for individuals in rotational romantic relationships.     

Father hunger and narcissistic deformation

The author advances the hypothesis that paternal availability and the relationship between the mother and father are crucial components of evolving character structure in children. He proposes that a kind of narcissistic pathology featuring perverse sexuality may eventuate in the absence of paternal availability and in the presence of a disordered relationship between the parents. He also suggests that the ways in which aggression is or is not modulated and organized are crucial components of this evolving disorder, and that boys are more susceptible to its full manifestation and expression than are girls.     

Influence of mode of deformation on microstructural heterogeneities in Ni subjected to large strain deformation

In the present work, the effect of deformation mode (uniaxial compression, rolling and torsion) on the microstructural heterogeneities in a commercial purity Ni is reported. For a given equivalent von Mises strain, samples subjected to torsion have shown higher fraction of high-angle boundaries, kernel average misorientation and recrystallization nuclei when compared to uniaxially compressed and rolled samples. This is attributed to the differences in the slip system activity under different modes of deformation.     

Explaining features of fine-grained phenomena using abstract analyses of phenomena and mechanisms: two examples from chronobiology

Explanations of biological phenomena such as cell division, protein synthesis or circadian rhythms commonly take the form of models of the responsible mechanisms. Recently philosophers of science have attempted to analyze this practice, presenting mechanisms as organized collections of parts performing operations that together produce the phenomenon. But in some cases what researchers seek to explain is not a general phenomenon, but a specific feature of a more fine-grained phenomenon. In some of these cases, it is not the model of the mechanism that performs the explanatory work. I consider a case in which the investigator offered an abstract representation of a fine-grained phenomenon to show why in had the feature in question. I consider a second case in which a researcher abstracted from the mechanism to identify a design principle that explains why the functioning mechanism exhibits a specific feature.