Finite element analysis of the effects of martensitic phase transformation in TRIP steel sheet forming

This paper aims at investigating the effects of the martensitic phase transformation on the formability of unstable austenitic steel sheets. To this end, the constitutive model developed by Iwamoto and Tsuta (International Journal of Plasticity 2002;18:1583–606) has been implemented in the user's material subroutine of the finite element code Abaqus/Explicit. The different contributions of the martensitic transformation to the overall plastic behaviour are analysed with the aim of assessing their influence in sheet-metal forming. The effects of transformation strains, and of the stress-state dependence of the kinetics of phase transformation are critically discussed in the case of the cup drawing test. The simulation results are also compared with experimental cup tests from the literature.     

Modifying YCN key assignment scheme to resist the attack from Hwang

This paper presents a modified YCN cryptographic key assignment scheme in a hierarchy with exceptions which is secure against Hwang's attack.     

Cerebrovascular response in infants and young children following severe traumatic brain injury: a preliminary report

PURPOSE: Endotoxin (lipopolysaccharide [LPS])-induced systemic organ injury leads to disruption of normal systemic organ metabolic processes, which are manifest clinically by signs of accelerated anaerobic metabolism (e.g., tissue acidosis and hyperlactatemia) and altered VO2-DO2 relationships. The association of increased anaerobic metabolism with VO2-DO2 alterations has led to the notion that ischemia/ reperfusion (I/R) injury may be a prerequisite for the development of VO2-DO2 alterations during endotoxemia. However, in contrast to sepsis, in which oxygen consumption is often increased, oxygen consumption is severely decreased after I/R injury. Based on these observations, we hypothesized that I/R injury would result in systemic organ VO2-DO2 alterations, which are distinct from those that occur in sepsis. MATERIALS AND METHODS: We used the in situ autoperfused feline ileal preparation to simultaneously examine microvascular permeability, reflected as the ileal lymph to plasma protein concentration ratio (CL/CP), and ileal VO2-DO2 relationships after either intravenous LPS (2.0 mg/kg; n = 5) or I/R injury (n = 5), and in matching controls (n = 5). RESULTS: As expected, all LPS-treated and I/R-injured animals were found to have extensive ileal histological damage and marked increases in the CL/CP compared with controls (0.315 +/- 0.009 and 0.329 +/- 0.034, respectively, v 0.097 +/- 0.009; P < .001, both comparisons). In addition, the critical DO2 (DO2c) was elevated, and the critical oxygen extraction was decreased in both the I/R and LPS groups relative to controls. However, as initially hypothesized, the VO2 at the critical DO2 was markedly decreased in the I/R group compared with that of the LPS group. CONCLUSIONS: These data indicate that I/R injury is insufficient to account for the systemic organ VO2-DO2 alterations that occur with LPS injury.     

Rules for neuropsychological diagnosis: Classification of brain function in older children.

A system of rules based on neuropsychological test data and the 2nd author's 4 methods of inference (level of performance, right–left differences, patterns of performance, and pathognomonic signs) was developed for classifying 3 samples (19 Ss each) of 9–14 yr old children as normal, learning disabled, or brain damaged. The 37 rules used a 4-point scaled scoring system with 0 representing adequate performance, 3 indicating distinctly abnormal performance, and 1 and 2 indicating intermediate performance. The rules system classified children into the 3 groups (normal, learning disabled, and brain damaged) with 73.3% accuracy. Although in need of replication, results indicate that the rules system is sensitive to neuropsychological differences between these groups and represents a set of initial guidelines for differentiating among normal, brain-damaged, and learning disabled children. Results also support the contention that learning disability often represents a degree of cerebral dysfunction that is frequently undetected by neurological examination but that can be reliably measured by neuropsychological tests. (9 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The dorsal tegmental noradrenergic projection: An analysis of its role in maze learning.

Evaluated the hypothesis that the noradrenergic projection from the locus coeruleus (LC) to the cerebral cortex and hippocampus is an important neural substrate for learning. Four experiments were conducted with 61 male Wistar rats. Maze performance was studied in Ss receiving either electrolytic lesions of LC or 6-hydroxydopamine (6-OHDA) lesions of the dorsal tegmental noradrenergic projection. The LC lesions did not disrupt the acquisition of a running response for food reinforcement in an L-shaped runway, even though hippocampal-cortical norepinephrine (NE) was reduced to 29%. Greater telencephalic NE depletions (to 6% of control levels) produced by 6-OHDA also failed to disrupt the acquisition of this behavior or to impair the acquisition of a food-reinforced position habit in a 'T'-maze. Neither locomotor activity nor habituation to a novel environment was affected by the 6-OHDA lesions. Ss with such lesions were, however, found to be significantly more distractible than were controls during the performance of a previously trained response. The hypothesis that telencephalic NE is of fundamental importance in learning was not supported. The data suggest that this system may participate in attentional mechanisms. (24 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Emotions and the microcomputer: An exploratory study of young children's responses

The emotional effects of early microcomputer use are of interest to educators and child development researchers. This study took a microanalytic emotion coding system which has been used in basic child development research, and applied it to exploring the effects of computer use on children's emotional responses. Sixteen 5-year-old children were videotaped while using three pieces of software (a drawing program, a face construction program, and a counting program). All three pieces elicited more active, positive, and complex facial expressions than did a comparison segment of television watching. Greater levels of concentration and more socially responsive behavior were also seen in the computer conditions. The drawing program tended to elicit more indicators of concentration and social engagement than the other two, although individual preferences and sample size made conclusions tentative. Results appear to reflect the motivational value of emotions and children's interest in experiences which offer autonomy and control. On the basis of this exploratory study, the methodology seems to have potential for investigating other aspects of children's emotional responses to computers.     

Solution structure, rotational diffusion anisotropy and local backbone dynamics of Rhodobacter capsulatus cytochrome c2

The solution structure, backbone dynamics and rotational diffusion of the Rhodobacter capsulatus cytochrome c2 have been determined using heteronuclear NMR spectroscopy. In all, 1204 NOE-derived distances were used in the structure calculation to give a final ensemble with 0.59(+/-0.08) A rms deviation for the backbone atoms (C, Calpha and N) with respect to the mean coordinates. There is no major difference between the solution structure and the previously solved X-ray crystal structure (1.07(+/-0.07) A rms difference for the backbone atoms), although certain significant local structural differences have been identified. This protein contains five helical regions and a histidine-heme binding domain, connected by a series of structured loops. The orientation of the helices provides an excellent sampling of angular space and thus allows a precise characterization of the anisotropic diffusion tensor. Analysis of the hydrodynamics of the protein has been performed by interpretation of the 15N relaxation data using isotropic, axially asymmetric and fully anisotropic diffusion tensors. The protein can be shown to exhibit significant anisotropic reorientation with a diffusion tensor with principal axes values of 1.405(+/-0.031)x10(7) s-1, 1.566(+/-0.051)x10(7) s-1 and 1.829(+/-0.054)x10(7) s-1. Hydrodynamic calculations performed on the solution structure predict values of 1.399x10(7) s-1, 1.500x10(7) s-1 and 1.863x10(7) s-1 when a solvent shell of 3.5 A is included in the calculation. The optimal orientation of the diffusion tensor has been incorporated into a hybrid Lipari-Szabo type local motion-anisotropic rotational diffusion model to characterize the local mobility in the molecule. The mobility parameters thus extracted show a quantitative improvement with respect to the model-free analysis assuming isotropic reorientation; helical regions exhibit similar dynamic properties and fewer residues require more complex models of internal motion. While the molecule is essentially rigid, a tripeptide loop region (residues 101 to 103) exhibits flexibility in the range of 20 to 30 ps, which appears to be correlated with the order in the NMR solution structure.     

Prolegomenon to the study of apparatus in early psychological laboratories circa 1875-1915.

Although the initial phase of experimental psychology is often referred to as the era of "brass instrument psychology," historians have generally ignored the equipment that was used in favor of the contributions of individuals and "schools." the present paper urges historians to explore the ways in which the linkage between mechanical facilities and concepts interacted and to trace the effects of technological as well as theoretical difficulties. Although attrition of relevant data has occurred, some existent sources are identified including stock lists of manufacturers, laboratory manuals and university inventories, photographs, journal articles, and reminiscences of psychologists. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Fatty acids of pimiento pepper seed oil

Pimiento pepper (Capsicum annum L.) seed oil was shown to contain 66–71% linoleic acid with smaller quantities of 16 and 18 carbon saturated and monounsaturated fatty acids. Neither geographical location nor location within pimiento processing plants influenced the level or composition of the seed oil. Two varieties of bell-type peppers were shown to have essentially the same seed oil composition as that of pimientos. Oil extracted from the fruit wall and placenta of pimientos was red and contained high levels of linolenic and small quantities of very long chain polyunsaturated fatty acids. Journal Series Paper No. 462, Georgia Experiment Station, Experiment, Ga.     

Frontiers of current research: Section introduction.

This article introduces the special section in the current issue of the American Psychologist. The articles in this section appear in two groups. The first is titled "Developmental Perspectives"; the second is titled "Learning and Teaching." (PsycINFO Database Record (c) 2010 APA, all rights reserved)