Effect of Composition and Processing Parameters on the Formation of Nano-Bainite in Advanced High Strength Steels

The nano-bainitic microstructures were compared in a 0.79C-1.5Si-1.98Mn-0.24Mo-1.06Al (wt%) steel after isothermal heat-treatment and a Fe-0.2C-1.5Mn-1.2Si-0.3Mo-0.6Al-0.02Nb (wt%) steel after controlled thermomechanical processing.The microstructure for both steels consisted of bainite.The microstructural characteristics of bainite,such as the morphology of the nano-bainite and thicknesses of bainitic ferrite and retained austenite layers,as a function of steel composition and processing was studied using transmission electron microscopy (TEM).It was found that the nano-bainitic structure can be formed in the low alloy steel through thermomechanical processing.Atom probe tomography (APT) was employed as a powerful technique to determine local composition distributions in three dimensions with atomic resolution.The important conclusions from the APT research were that the carbon content of bainitic ferrite is higher than expected from paraequilibrium level of carbon in ferrite for both steels and that Fe-C clusters and fine particles are formed in the bainitic ferrite in both steels despite the high level of Si.     

Routine and the Perception of Time.

The authors investigated the influence of routine on people's estimation of time, testing the hypothesis that duration is remembered as being shorter when time is spent in a routine activity. In 4 experiments and 2 field studies, the authors compared time estimations in routine and nonroutine conditions. Routine was established by a sequence of markers (Study 1), variation of the task (Studies 2 and 3), or the number of repetitive blocks (Study 4). As hypothesized, the duration of the task was remembered as being shorter in routine conditions than in nonroutine ones. This trend was reversed in experienced (prospective) judgments when participants were informed beforehand of the duration-judgment task (Study 3). In Studies 5 and 6, the authors examined remembered duration judgments of vacationers and kibbutz members, which provided further support for the main hypothesis. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Molecular Dynamics of Methylamine Following C?H and N?H Vibrational Excitation and Promotion to the à State

The molecular dynamics of methylamine, CH₃NH₂, was investigated via vibrationally mediated photodissociation. It was found that the ∼243.1 nm photolysis of initially excited N–H and C–H fundamental stretches and combinations and overtones of methyl deformation yields H photofragments. Surprisingly, the deformations promote the H atom release more effectively, implying mode-dependent enhancement of photodissociation in a relatively large molecule with a torsional degree of freedom. The H Doppler profiles correspond to low translational energies, supporting the dominant non-adiabatic N–H dissociation channel.     

The status of rapid response learning in aging.

Strong evidence exists for an age-related impairment in associative processing under intentional encoding and retrieval conditions, but the status of incidental associative processing has been less clear. In 2 experiments, we examined the effects of age on rapid response learning—the incidentally learned stimulus–response association that results in a reduction in priming when a learned response becomes inappropriate for a new task. Specifically, we tested whether priming was equivalently sensitive in both age groups to reversal of the task-specific decision cue. Experiment 1 showed that cue inversion reduced priming in both age groups with a speeded inside/outside classification task, and in Experiment 2, cue inversion eliminated priming on an associative version of this task. Thus, the ability to encode an association between a stimulus and its initial task-specific response appears to be preserved in aging. These findings provide an important example of a form of associative processing that is unimpaired in older adults. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The role of expectations in comparisons.

Expectations are proposed as a unifying framework for explaining a variety of findings on comparative judgment. Expectations may pertain to either the features of each separate object or their simultaneous occurrence in all relevant objects. Two experiments demonstrate that inducing expectations by varying the frequency with which a component occurs, as well as the frequency with which it is shared by the compared objects, results in augmented weighting of unexpected components. Expectations can arise not only from experienced frequencies but also from an inferred set of alternatives. Features of cohesive stimuli are shown to be more expected than features of noncohesive stimuli, in the latter sense. The relatively higher weighting of distinctive features in cohesive stimuli, as well as the higher weight assigned to structurally aligned differences, could thus reflect modifications in feature expectedness. Further experiments show how task-dependent weighting interacts with expectations to produce asymmetries between similarity and difference judgments. Finally, it is argued that changes in expectations regarding objects' attributes can explain context effects across different domains, including some types of preference reversals. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Catheters coated with Zn-doped CuO nanoparticles delay the onset of catheter-associated urinary tract infections

Catheter-associated urinary tract infections (CAUTIs) are among the most common bacterial infections associated with medical devices.In the current study,the synthesis,coating,antibiofilm properties,and biocompatibility of urinary catheters coated with Zn-doped CuO (Zn0.12Cu0.~O) nanoparticles (NPs) were examined.The doped NPs were synthesized and subsequently deposited on the catheter by the sonochemical method.The coated catheters displayed high antibiofilm activity and promising biocompatibility,as indicated by low in vitro cytotoxicity,negligible associated cytokine secretion,and absence of detectable irritation.The biocompatibility and ability of the Zn-doped CuO coating to inhibit biofilm formation were also evaluated in vivo using a rabbit model.Rabbits catheterized with uncoated catheters scored positive for CAUTI by day 4 of the experiment.In contrast,rabbits catheterized with Zn-doped CuO-coated catheters did not exhibit CAUTI until day 7 or remained completely uninfected for the whole duration of the 7-day experiment.Furthermore,.the in vivo biocompatibility assays and examinations supported the biosafety of Zn-doped CuO-coated catheters.Taken together,these data highlight the potential of Zn-doped CuO nanocomposite as effective antibiofilm compound.     

Ambivalence over emotional expression and well-being: Nomothetic and idiographic tests of the stress-buffering hypothesis.

Examined nomothetic and idiographic relations between ambivalence over emotional expression (as expressed by the Ambivalence Over Emotional Expression Questionnaire; AEQ) and well-being in a 4-mo study with an interim 2-wk diary component. Ss were 66 undergraduates. Nomothetic and idiographic analyses both revealed that AEQ was related to psychological health but not to physical well-being. The nomothetic test of stress-buffering showed that AEQ was more predictive of depression among Ss who had experienced higher levels of positive life-event stress. In contrast, the idiographic test of stress-buffering revealed that Ss higher in AEQ exhibited less covariation between daily stress and negative affect over time. It is proposed that AEQ may reflect 2 types of emotional vulnerability: emotional reactivity and emotional perseveration. (PsycINFO Database Record (c) 2010 APA, all rights reserved)