Rapid Polymer Prototyping for Low Cost and Robust Microrobots

The Rapid Microrobot Prototyping (RaMP) Process uses Loctite(R) photo-patternable polymer products and photolithography to rapidly fabricate robust, inexpensive, and compliant robots. The process is developed and examined on two size scales. On the size scale of several centimeters, two functional robots and a small gripper have been designed and demonstrated with shape memory alloy (SMA) used for actuation. The gripper is 1.2g and costs $3.21 while the inchworm robot is 7.4g and costs$7.76 in small numbers. The second robot costs $14.93 in small numbers. On the sub-centimeter scale, designs and considerations for a walking microrobot fabricated with the process and its control are fully described. The design and kinematics of a thermally actuated, one degree of freedom leg for the microrobot are developed and simulated. Several of these units could be combined to rapidly build a 30 mg functional and simple walking microrobot with the ability to lift several grams

Grace in the Face of Conflict: Can Grace and Courtesy and Peace Curriculum Lessons create a Peaceful Classroom?

GRACE IN THE FACE OF CONFLICT 2 Abstract The purpose of the study was to determine if consistent and purposeful Grace and Courtesy lessons would result in a decrease in student conflicts and disruptive behaviors. The study was conducted in a private Montessori school in Metropolitan NYC. The subjects were 21 Early Childhood (ages 3 to 6) students. Sources of data included a checklist of Grace and Courtesy lessons, a Zone Map to document places of conflicts/disturbances, and a Redirection/Incident journal documenting redirections and incidents by child, and the lessons given them. The conclusion was that there was not enough time to fully develop what is now understood to be a lengthy and intensive research study. The presence of “outlier” students also detracted from the message the lessons were providing. I will continue to deliver the Grace and Courtesy lessons as planned, and will reapply the same processes at the commencement of the next school year

High strain rate effect on tensile ductility and fracture of AM fabricated Inconel 718 with voided microstructures

The paper describes Electromagnetic Ring Expansion Tests (ERET) performed on Laser Melting Powder Bed Fusion (LPBF) Inconel 718 stress relieved test pieces, to establish the effect of a randomly dispersed spherically voided microstructure on tensile ductility, fracture, and fragmentation at high strain rate (10-3 < e < 104 s-1). An empirical model to predict porosity type and growth rates as a function of laser energy density was established, to select the LPBF process parameters to fabricate test pieces under stable conduction and keyhole melting. The size, shape, distribution of macro and keyhole pores in the test pieces obtained for ERET testing were characterised. At high strain rate the number of ring fragments for the highest porosity doubled, accompanied by a reduction in true strain at maximum uniform elongation and fracture strain. The trend for reducing fracture strain with increasing porosity at high strain rate was described by a decaying power law. Overall, there was a significant positive strain rate effect on tensile ductility at lower porosities attributed strain rate hardening (Hart, 1967) [1]. Fracture surfaces containing the highest porosity identified four different void coalescence mechanisms that helped explain the influence of larger pores on the stress state in the alloy.The AM of IN718 and tensile testing was funded by the UoD, College of Science and Engineering Research Excellence Framework (REF) funding for the Director of IISE (P. Wood) and AM Researcher (U. Gunputh). The support of G. Williams for IN718 sample preparation and M. Pawlik for tensile testing is acknowledged. A. Rusinek acknowledges the program UC3M-Santander Chair of Excellence in additive manufacturing. The expanding ring tests investigations were funded by the Polish Ministry of Science and Higher Education, Centre for Research and Development under research grant No. TECHMATSTRATEG2/410049/12/NCBR/2019

Pupil dilation as an implicit measure of appetitive Pavlovian learning

Appetitive Pavlovian conditioning is a learning mechanism of fundamental biological and pathophysiological significance. Nonetheless, its exploration in humans remains sparse, which is partly attributed to the lack of an established psychophysiological parameter that aptly represents conditioned responding. This study evaluated pupil diameter and other ocular response measures (gaze dwelling time, blink duration and count) as indices of conditioning. Additionally, a learning model was used to infer participants' learning progress on the basis of their pupil dilation. Twenty-nine healthy volunteers completed an appetitive differential delay conditioning paradigm with a primary reward, while the ocular response measures along with other psychophysiological (heart rate, electrodermal activity, postauricular and eyeblink reflex) and behavioral (ratings, contingency awareness) parameters were obtained to examine the relation among different measures. A significantly stronger increase in pupil diameter, longer gaze duration and shorter eyeblink duration was observed in response to the reward-predicting cue compared to the control cue. The Pearce-Hall attention model best predicted the trial-by-trial pupil diameter. This conditioned response was corroborated by a pronounced heart rate deceleration to the reward-predicting cue, while no conditioning effect was observed in the electrodermal activity or startle responses. There was no discernible correlation between the psychophysiological response measures. These results highlight the potential value of ocular response measures as sensitive indices for representing appetitive conditioning

Pupillometry and P3 index the locus coeruleus– noradrenergic arousal function in humans

The adaptive gain theory highlights the pivotal role of the locus coeruleus–noradrenergic (LC-NE) system in regulating task engagement. In humans, however, LC-NE functional dynamics remain largely unknown. We evaluated the utility of two candidate psychophysiological markers of LC-NE activity: the P3 event-related potential and pupil diameter. Electroencephalogram and pupillometry data were collected from 24 participants who performed a 37-min auditory oddball task. As predicted by the adaptive gain theory, prestimulus pupil diameter exhibited an inverted U-shaped relationship to P3 and task performance such that largest P3 amplitudes and optimal performance occurred at the same intermediate level of pupil diameter. Large phasic pupil dilations, by contrast, were elicited during periods of poor performance and were followed by reengagement in the task and increased P3 amplitudes. These results support recent proposals that pupil diameter and the P3 are sensitive to LC-NE mode

Household Contamination with Salmonella enterica1

Household contamination with Salmonella enterica increases when occupational exposure exists (cattle farms with known salmonellosis in cattle, a salmonella research laboratory, or a veterinary clinic experiencing an outbreak of salmonellosis). Fifteen of 55 (27.2%) vacuum cleaner bags from households with occupational exposure to S. enterica were positive versus 1 of 24 (4.2% without known exposure. Use of a carpet cleaner and several cleaners/disinfectants reduced, but failed to eliminate, S. enterica from artificially contaminated carpet