Is There Enhanced Depletion of Gas-Phase Nitrogen in Moderately Reddened Lines of Sight?

We report on the abundance of interstellar neutral nitrogen (NI) for 30 sightlines, using data from the Far Ultraviolet Spectroscopic Explorer (FUSE) and the Hubble Space Telescope (HST). NI column densities are derived by measuring the equivalent widths of several ultraviolet absorption lines and subsequently fitting those to a curve of growth. We find a mean interstellar N/H of 51+/-4 ppm. This is below the mean found by Meyer et al. of 62(+4,-3) ppm (adjusted for a difference in f-values). Our mean N/H is similar, however, to the (f-value adjusted) mean of 51+/-3 ppm found by Knauth et al. for a larger sample of sightlines with larger hydrogen column densities comparable to those in this study. We discuss the question of whether or not nitrogen shows increased gas-phase depletion in lines of sight with column densities log(H_tot) >~ 21, as claimed by Knauth et al. The nitrogen abundance in the line of sight toward HD 152236 is particularly interesting. We derive very small N/H and N/O ratios for this line of sight that may support a previous suggestion that members of the Sco OB1 association formed from an N-deficient region.Comment: Accepted in The Astrophysical Journal, 9/2006 (expected pub. date: 1/2007) 38 pages, 5 figures (4 color

Attribution of Responsibility after Failures within Platform Ecosystems

Increasingly, new hardware and software are embedded within ecosystems that include a platform and modules. Ideally these ecosystems perform reliably. However, if an ambiguously sourced failure occurs within one of these ecosystems, users are left to distribute blame across the various components of the ecosystem. The actual distribution of this blame, however, can be difficult to predict. This study investigates attribution of blame and discontinuance recommendations for ecosystem components after an ambiguously sourced failure. To extend platform ecosystems and attribution theory, we conducted a scenario-based experiment investigating the negative consequences of failure for platform and module components and the contingent effects from design elements (border strength) and contextual factors (task goal directedness, disruption severity). Results demonstrated a diffusion of negative consequences for failure across ecosystem components, but ecosystem modules (apps) received the majority of the blame and highest discontinuance recommendations. High border strength shifted negative consequences for failure away from the OS to the device. Low goal-directedness resulted in users taking more of the blame for the failure, and higher disruption severity resulted in higher discontinuance recommendations for the OS and device. Importantly, the amount of blame attributed to one component in an ecosystem predicted discontinuance recommendations for other components

EFFECTS OF FRONT SQUAT TRAINING METHODS ON FRONT SQUAT ONE REPETITION MAX AND CLEAN PULL FORCE PRODUCTION

This study examined effects of a 6 week front squat training program using a standard weight lifting technique (control) or a time under tension (TUT) technique on clean pull peak ground reaction force (pGRF) and front squat one rep maximum (1RM). Male collegiate subjects (n=9) with strength training experience performed a front squat 1RM. They also did a clean pull with their reported clean 1RM on force platforms pre and post training to determine pGRF. Front squat 1RM and pGRF for the clean didn’t differ between groups (p\u3e0.05) from pre to post-testing. Front squat 1RM increased 5.3% from pre to post in the TUT group, and 2.9% in the control group. Overall from pre to post-training there was a significant increase in front squat 1RM and relative strength (

EFFECTS OF CUTTING WEIGHT VIA SAUNA ON FORCE PRODUCTION AND RATE OF FORCE DEVELOPMENT FOR THE OLYMPIC SNATCH PULL

This study examined the effects of cutting weight on ground reaction force (GRF), rate of force development (RFD) for the snatch pull. Vertical jump (VJ) was also tested compared to normal conditions. Olympic male weightlifters (n=7) used sauna and food/water restrictions (SW) to achieve 1-2% body mass loss. Snatch pull peak vertical GRF, RFD and VJ height after SW didn’t differ from control pulls (p >0.05). Mean (±SD) GRF for control = 2405 ± 381 N; while after cutting weight and sauna = 2241 ± 404 N. VJ control after pulls mean = 56.0 ± 9.7 cm. Vertical jump on the weight cut day after pulls mean = 58.0 ± 9.2 cm. GRF decreased by 12.7% and VJ increased by 3.4% after weight cutting compared to control; however, these performance variables were not significantly different from the control condition (p > 0.05)

Eye of the Blamestorm: An Exploration of User Blame Assessment within Compound Digital Platforms

More and more IS-enabled technologies are being used within the context of ecosystems that include both hardware and software components that act together as a central platform; we term these ecosystems digital compound platform ecosystems. However, given the interconnectedness of components within these platforms, if an ambiguously sourced failure occurs within one of these ecosystems, users may blame and/or take action against components in the ecosystem that were not actually at fault. This study considers antecedents of both blame and discontinuance intent within such ecosystems given a system failure of ambiguous origins. We test manipulations for border strength, goal directedness, and resolution duration to understand their impact. We find that all three of these manipulations have an effect on user assessment of blame and discontinuance intent. Further, we establish that blame is not a required condition for discontinuance intent to occur

Free volume variation with molecular weight of polymers

Free volume measurements were made in several molecular weight fractions of two different geometries of poly(arylene ether ketone)s. Free volumes were measured using positron lifetime spectroscopy. It has been observed that the free volume cell size V(sub f) varies with the molecular weight M of the test samples according to an equation of the form V(sub f) = AM(B), where A and B are constants. The molecular weights computed from the free volume cell sizes are in good agreement with the values measured by gel permeation chromatography

TRIATHLON CYCLE-RUN TRANSITION: SEATED VERSUS ALTERNATING SEATED AND STANDING CYCLING

Nine experienced triathletes completed two trials of a cycle to run transition. During the last three minutes of a 30 minute cycling bout (at power output equal to lactate threshold) subjects either remained seated (SEAT), or alternated seated and standing cycling (30 s at a time) (ALT). Minimum and maximum knee angle and stride frequency were obtained at the end of a three minute control run (C) and at minutes 0, 2, & 4, of running after cycling transition. The only difference found by Two-Way Repeated Measures ANOVA (condition X minute) was that C was significantly different than minute 0 of the transition for stride frequency (

Low-force contact heating and softening using micromechanical switches in diffusive-ballistic electron-transport transition

We demonstrate softening of the gold-to-gold contact in surface micromachined microelectromechanical switches under electrostatic force near 30 μN30μN, which results from the heating of contact asperities sustaining electron transport. A bias potential that causes the switch contacts to soften is measured for initial contact resistance varying between 0.5 and 300 Ω300Ω. The asperity sizes in this range are comparable to the electron mean-free path at room temperature. We show that contact spots smaller than the mean-free path require larger bias for softening. Our results can be explained using a model accounting for ballistic electron transport in the contact.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87858/2/023507_1.pd