Paul DeYoung

Transfer and/or Breakup Modes in The He-6+Bi-209 Reaction Near the Coulomb Barrier

Reaction products from the interaction of 6He with 209Bi have been measured at energies near the Coulomb barrier. A 4He group of remarkable intensity, which dominates the total reaction cross section, has been observed. The angular distribution of the group suggests that it results primarily from a direct nuclear process. It is likely that this transfer and/or breakup channel is the doorway state that accounts for the previously observed large sub-barrier fusion enhancement in this system.

Amperometric detection of hydrazine by cyclic voltammetry and flow injection analysis using ruthenium modified glassy carbon electrodes

Glassy carbon electrodes modified with (5-amino-1,10-phenanthroline)bis(bipyridine)ruthium(II) chloride hydrate, [(bpy)(2)Ru(5-phenNH(2))]Cl(2).H(2)O, are shown to oxidize hydrazine with excellent sensitivity. The presence of an amine group on the ruthenium complex facilitates electropolymerization onto the electrode surface. Using cyclic voltammetry, a large catalytic current is observed upon oxidation of hydrazine in phosphate buffer (pH 5.0), compared to the current obtained from the ruthenium-modified electrode with no hydrazine present. The sensitivity of cyclic voltammetry is sufficient for obtaining a linear calibration curve for hydrazine over the range of 10(-5) to 10(-2)M. Hydrodynamic amperometry was used to determine the working potential for flow injection analysis. The limit of detection for hydrazine was determined to be 8.5muM using FIA. The thickness of these films was shown to increase linearly with the number of electropolymerization cycles, in the range of 1000-2500nm for 5-20 cycles, respectively, using Rutherford backscattering spectrometry (RBS). RBS analysis also suggests that the film is multilayered with the outermost layers containing a high ruthenium concentration, followed by layers where the concentration of ruthenium decreases linearly and approaches zero at the electrode surface.

Evidence for the ground-state resonance of 26O.

Evidence for the ground state of the neutron-unbound nucleus (26)O was observed for the first time in the single proton-knockout reaction from a 82 MeV/u (27)F beam. Neutrons were measured in coincidence with (24)O fragments. (26)O was determined to be unbound by 150(-150)(+50) keV from the observation of low-energy neutrons. This result agrees with recent shell-model calculations based on microscopic two- and three-nucleon forces.

Compassion-focused reappraisal, benefit-focused reappraisal, and rumination after an interpersonal offense: Emotion-regulation implications for subjective emotion, linguistic responses, and physiology

This repeated measures psychophysiology experiment studied three responses to a past interpersonal offense (38 females and 33 males). We compared rumination with two offense reappraisal strategies. Compassion-focused reappraisal emphasized the offenders humanity, and interpreted the transgression as evidence of the offenders need for positive transformation. Benefit-focused reappraisal emphasized insights gained or strengths shown in facing the offense. Supporting the manipulations, compassion-focused reappraisal stimulated the most empathy and forgiveness, whereas benefit-focused reappraisal prompted the most benefit language and gratitude. Both reappraisals decreased aroused, negative emotion, and related facial muscle tension at the brow (corrugator). Both reappraisals increased happiness and positive emotion in ratings and linguistic analyses. Compassion stimulated the greatest social language, calmed tension under the eye (orbicularis oculi), and slowed heart beats (R–R intervals). A focus on benefits prompted the greatest joy, stimulated smiling (zygomatic) activity, and buffered the parasympathetic nervous system against ruminations adverse effects on heart rate variability (HRV).

Study of Two-Neutron Radioactivity in the Decay of 26O

A new technique was developed to measure the lifetimes of neutron unbound nuclei in the picosecond range. The decay of 26O→24O+n+n was examined as it had been predicted to have an appreciable lifetime due to the unique structure of the neutron-rich oxygen isotopes. The half-life of 26O was extracted as 4.5(-1.5)(+1.1)(stat)±3(syst)  ps. This corresponds to 26O having a finite lifetime at an 82% confidence level and, thus, suggests the possibility of two-neutron radioactivity.

Compassionate reappraisal and emotion suppression as alternatives to offense-focused rumination: Implications for forgiveness and psychophysiological well-being

This within subjects experiment (28 females, 26 males) examined three responses to a past interpersonal offender. We contrasted offense-focused rumination with two subsequent, counterbalanced coping strategies: compassionate reappraisal and emotion suppression. Compassionate reappraisal emphasized the offenders human qualities and need for positive change. Emotion suppression inhibited the experience and expression of negative offense-related emotions. Offense rumination was associated with negative emotion, faster heartbeats (i.e., shortened electrocardiogram R-R intervals), and lower heart rate variability (HRV; i.e., the high-frequency component of the R-R power spectrum). By contrast, both compassionate reappraisal and emotion suppression decreased negative emotion in ratings and linguistic analyses, calmed eye muscle tension (orbicularis oculi EMG, electromyography), and maintained HRV at baseline levels. Suppression inhibited negative emotion expression at the brow (corrugator EMG) and slowed cardiac R-R intervals, but without forgiveness effects. Only compassionate reappraisal significantly increased positive emotions, smiling (zygomatic EMG), and social language along with forgiveness.

MoNA—The Modular Neutron Array

The Modular Neutron Array (MoNA), a highly efficient time-of-flight neutron detector, is being constructed for use at the National Superconducting Cyclotron Laboratory. The modular design of the detector provides significant flexibility and allows the bulk of the assembly and testing to be done by undergraduates at nine of the schools participating in the project.

Search for 21C and constraints on 22C

A search for the neutron-unbound nucleus

Search for

^{21}

^{21}

C was performed via the single proton removal reaction from a beam of 22 N at 68 MeV/u. Neutrons were detected with the Modular Neutron Array (MoNA) in coincidence with