274 research outputs found
Facial expressions and personality: A kinematical investigation during an emotion induction experiment
Background/Aims: In order to elucidate the relationship between personality traits and expression of positive emotions in healthy volunteers, standardized personality inventories and kinematical analysis of facial expressions can be helpful and were applied in the present study. Methods: Markers fixed at distinct points of the face emitting ultrasonic signals at high frequency gave a direct measure of facial movements with high spatial-temporal resolution. Forty-six healthy participants (mean age: 40.7 years; 20 males, 26 females) watching a witty movie ('Mr. Bean') were investigated. Results: Speed of `laughing' was associated with higher scores on Zuckerman's Sensation Seeking Scale and NEO-FFI (Openness to Experience). Conclusion: Kinematical analysis of facial expressions seems to reflect sensation seeking and related personality styles. Higher speed of facial movements in sensation seekers suggests lowered serotonergic function. Copyright (c) 2006 S. Karger AG, Basel
Finite element analysis of in-situ distortion and bulging for an arbitrarily curved additive manufacturing directed energy deposition geometry
With the recent rise in the demand for additive manufacturing (AM), the need for reliable simulation tools to support experimental efforts grows steadily. Computational welding mechanics approaches can simulate the AM processes but are generally not validated for AM-specific effects originating from multiple heating and cooling cycles. To increase confidence in the outcomes and to use numerical simulation reliably, the result quality needs to be validated against experiments for in-situ and post-process cases. In this article, a validation is demonstrated for a structural thermomechanical simulation model on an arbitrarily curved Directed Energy Deposition (DED) part: at first, the validity of the heat input is ensured and subsequently, the model’s predictive quality for in-situ deformation and the bulging behaviour is investigated. For the in-situ deformations, 3D-Digital Image Correlation measurements are conducted that quantify periodic expansion and shrinkage as they occur. The results show a strong dependency of the local stiffness of the surrounding geometry. The numerical simulation model is set up in accordance with the experiment and can reproduce the measured 3-dimensional in-situ displacements. Furthermore, the deformations due to removal from the substrate are quantified via 3D-scanning, exhibiting considerable distortions due to stress relaxation. Finally, the prediction of the deformed shape is discussed in regards to bulging simulation: to improve the accuracy of the calculated final shape, a novel extension of the model relying on the modified stiffness of inactive upper layers is proposed and the experimentally observed bulging could be reproduced in the finite element model
Impact of repetitive, ultra-short soft X-ray pulses from processing of steel with ultrafast lasers on human cell cultures
Ultrafast lasers, with pulse durations below a few picoseconds, are of
significant interest to the industry, offering a cutting-edge approach to
enhancing manufacturing processes and enabling the fabrication of intricate
components with unparalleled accuracy. When processing metals at irradiances
exceeding the evaporation threshold of about 10^10 W/cm2 these processes can
generate ultra-short, soft X-ray pulses with photon energies above 5 keV. This
has prompted extensive discussions and regulatory measures on radiation safety.
However, the impact of these ultra-short X-ray pulses on molecular pathways in
the context of living cells, has not been investigated so far. Using laser
pulses of 250 fs and 6.7 ps, along with pulse repetition rates exceeding 10
kHz, we conducted the first molecular characterization of epithelial cell
responses to ultra-short soft X-ray pulses generated during processing of steel
with ultrafast lasers. Ambient exposure of vitro human cell cultures, followed
by imaging of the DNA damage response and fitting of the data to an
experimentally calibrated model of dose rate estimation, revealed a linear
increase in the DNA damage response relative to the exposure dose. This is in
line with findings from work using continuous wave soft X-ray sources and
suggests that the ultra-short X-ray pulses do not generate additional hazard.
This research contributes valuable insights into the biological effects of
ultrafast laser processes and their potential implications for user safety
First captive breeding of a night skink (Scincidae: Eremiascincus) from Timor-Leste, Lesser Sunda Islands, with remarks on the reproductive biology of the genus
We report two instances of captive breeding in a species of Timorese night skink (genus Eremiascincus Greer, 1979) in October and December 2012. Four and three neonates, respectively, with total lengths of ca 40 mm each, were discovered during routine maintenance of a terrarium, in which three adult animals (1 male, 2 females) were kept. The absence of eggshells in the terrarium and the unlikelihood of post-eclosion oophagy by the adults suggest that the reproductive mode of the species is viviparous. We also provide a summary of available information pertaining to the reproductive biology of other members of the genus Eremiascincus
Mechanistic Insight into the Uptake and Fate of Persistent Organic Pollutants in Sea Ice
The fate of persistent organic pollutants in sea ice is a poorly researched area and yet ice serves as an important habitat for organisms at the base of the marine foodweb. This study presents laboratory-controlled experiments to investigate the mechanisms governing the fate of organic contaminants in sea ice grown from artificial seawater. Sea ice formation was shown to result in the entrainment of chemicals from seawater, and concentration profiles in bulk ice generally showed the highest levels in both the upper (ice–atmosphere interface) and lower (ice–ocean interface) ice layers, suggesting their incorporation and distribution is influenced by brine advection. Results from a 1-D sea ice brine dynamics model supported this, but also indicated that other processes may be needed to accurately model low-polarity compounds in sea ice. This was reinforced by results from a melt experiment, which not only showed chemicals were more enriched in saltier brine, but also revealed that chemicals are released from sea ice at variable rates. We use our results to demonstrate the importance of processes related to the occurrence and movement of brine for controlling chemical fate in sea ice which provides a pathway for exposure to ice-associated biota at the base of the pelagic food web
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