Kinetic Monte Carlo approach to modeling dislocation mobility

We describe a kinetic Monte Carlo (kMC) approach to modeling dislocation motion, directly linking the energetics of dislocation kink nucleation and migration on the atomistic scale with the experimental data on the microscale. A study of planar glide of screw dislocation in Si, an ideal test-bed for our method is first discussed, followed by preliminary results for a more complicated problem, three-dimensional motion of screw dislocation in BCC metals. We find that accuracy of the model predictions, even in the favorable case of Si, cannot claim to be quantitative because of uncertainties in the atomistic results for kink energetics. On the other hand, the kMC method is useful for qualitatively probing the mechanisms controlling dislocation motion, and it is capable of providing plausible explanation of some puzzling features of the experimental data.     

Convergences among psychoanalytic and cognitive-behavioral theories of depression.

Discusses 2 types of depression based on disruptions of (1) interpersonal relatedness or (2) self-esteem, and considers the nature, etiology, and treatment of depression based on the phenomenology of the issues that cause individuals to become depressed. The interpersonal perspective of S. Arieti and J. Bemporad (1980), the object relations perspective of J. Bowlby (see record 1988-16459-001), and the psychoanalytic ego psychology and cognitive developmental theory perspective of S. J. Blatt (1992) are compared and contrasted with each other and with the cognitive-behavioral perspective of A. T. Beck (1983). Areas of agreement and differences among these 4 theoretical positions are discussed in terms of their implications for treatment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of motive for helping, recipient's inability to reciprocate, and sex on devaluation of the recipient's competence.

Tested the prediction that motive base will interact with reciprocation such that greater superiority in perceived competence will occur following nonreciprocation than following reciprocation of efficacy-motivated helpers. It was hypothesized that this effect would be qualified by the helper's motivation for helping, the evaluative attribute in question, and the helper's set. 60 male and 60 female undergraduates were asked to imagine that during the preceding weekend they had successfully rescued a boatload of children. For half of the Ss, the scenario emphasized efficacy-motivating helping; for the other half, it emphasized empathy-motivated helping. Ss were then put to work on the "easier" of 2 "randomly assigned" word-forming tasks, whereas their same-sex partner (a confederate) worked on the "harder" task. Once Ss reached their quota they were invited to send their excess letters to the still-struggling co-worker; all did. In return, the confederate attempted successfully or unsuccessfully to share his or her earnings. As predicted, the efficacy-motivated helpers, unlike their empathy-motivated counterparts, rated themselves as more competent than, but not more sociable than, the recipient who was unable to reciprocate. Weak support was found for the prediction that these differences in perceived competence would largely apply to male helpers. (34 ref) (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Microstructure of Hardened Cement Paste—A New Interpretation

Morphological features of hydrated portland cement paste exhibited on carefully polished surfaces have been critically examined using backscatter mode scanning electron microscopy. A new interpretation and classification of such features is proposed. The microstructure is seen to consist of distinct grains of the order of 10 μm and larger ("phenograins") set in a cellular groundmass of smaller particles and pores. Most of the phenograins are dense pseudomorphs of the larger cement grains, but some are large calcium hydroxide crystals, and in some cements a few may represent inert filler grains added to the cement. The phenograins that are pseudomorphs of cement particles may be solid, gapped, or hollow; and, at a given age, various stages of hydration are represented in different grains. While many pseudomorph phenograins consist of a simple core of unhydrated material surrounded by a uniform shell of hydration product, more complex and irregular structures are also found. Relationships between these features and earlier classifications of cement hydration product particles are discussed, and implications with respect to difficulties in image analysis of hardened cement paste are examined.     

Supercomputers — past,present, prospects

In the fourth decade of the computer age, supercomputers are attracting increasingly more attention.     

Fredholm integral equation of the Laser Intensity Modulation Method (LIMM): Solution with the polynomial regularization and L-curve methods

The Laser Intensity Modulation Method (LIMM) is widely used for the determination of the spatial distribution of polarization in polar ceramics and polymers, and space charge in non-polar polymers. The analysis of experimental data requires a solution of a Fredholm integral equation of the 1st kind. This is an ill-posed problem that has multiple and very different solutions. One of the more frequently used methods of solution is based upon Tikhonov regularization. A new method, the Polynomial Regularization Method (PRM), was developed for solving the LIMM equation with an 8th degree polynomial using smoothing to achieve a stable and optimal solution. An algorithm based upon the L-curve method (LCM) was used for the prediction of the best regularization parameter. LIMM data were simulated for an arbitrary polarization distribution and were analyzed using PRM and LCM. The calculated distribution function was in good agreement with the simulated polarization distribution. Experimental polarization distributions in a poorly poled sample of polyvinylidene fluoride (PVDF) and in a LiNbO₃ bimorph, and space charge in polyethylene were analyzed. The new techniques were applied to the analysis of 3-dimensional polarization distributions.     

Individuality and relatedness: Evolution of a fundamental dialectic.

Western psychologies have traditionally given greater importance to self-development than to interpersonal relatedness, stressing the development of autonomy independence, and identity as central factors in the mature personality. In contrast, women, many minority groups, and non-Western societies have generally placed greater emphasis on issues of relatedness. This article traces the individualistic bias and recent challenges to this view. It is proposed that evolutionary pressures of natural selection result in 2 basic developmental lines: interpersonal relatedness and self-definition, which interact in a dialectical fashion. An increasingly mature sense of self is contingent on interpersonal relationships: conversely, the continued development of increasingly mature interpersonal relationships is contingent on mature self-definition. Conclusions include implications for social policy and for facilitating more balanced development of both dimensions in all members of society. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

"Impact of perfectionism and need for approval on the brief treatment of depression: The National Institute of Mental Health Treatment of Depression Collaborative Research Program revisited": Correction.

Reports an error in the original article by S. J. Blatt et al (Journal of Consulting and Clinical Psychology, 1995[Feb], 63[1], 125–232. Corrections in Table 2, which presented correlations of 5 measures of therapeutic change at pretreatment with 4 outcome variables, resulted in reducing the size and significance of the correlations of pretreatment Social Adjustment Scale scores in predicting therapeutic change. (The following abstract of this article originally appeared in record 1995-25991-001). Patients in the National Institute of Mental Health Treatment of Depression Collaborative Research Program (TDCRP) were administered at intake with the Dysfunctional Attitude Scale (DAS; A. N. Weissman & A. T. Beck 1978). Factor analyses of the DAS in the TDCRP data as well as in several independent samples reveal two primary factors: an interpersonal factor, Need for Approval, and a self-critical factor, Perfectionism. This study explored the hypotheses that these factors, assessed prior to treatment, would have differential interactions with the two forms of psychotherapy evaluated in the TDCRP as well as differential relationships to various outcome measures (depression, clinical functioning, and social adjustment). … (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The destructiveness of perfectionism: Implications for the treatment of depression.

Reports in the public media indicate that intense perfectionism and severe self-criticism played a role in the suicide of three remarkably talented individuals. The role of perfectionism in these suicides is consistent with recent extensive investigations of aspects of perfectionism as well as further analyses of the NIMH Treatment of Depression Collaborative Research Program (TDCRP), indicating that intense perfectionism interfered significantly with therapeutic response in the various brief treatments for depression. Self-critical individuals, however, made substantial improvement in long-term intensive treatment. These findings suggest the value of considering psychopathology, especially depression, from a psychological rather than a symptomatic perspective; that different patients may be differentially responsive to various types of therapy; and that more extensive therapy may be necessary for many highly perfectionistic, self-critical patients. (PsycINFO Database Record (c) 2010 APA, all rights reserved)