The Pedagogy of Digital Storytelling in the College Classroom

In the fall of 2008, Rachel Raimist and Walter Jacobs collaboratively designed and taught the course “Digital Storytelling in and with Communities of Color” to 18 undergraduate students from a variety of disciplines. Candance Doerr-Stevens audited the class as a graduate student. This article examines the media making processes of the students in the course, asking how participants used digital storytelling to engage with themselves and the media through content creation that both mimicked and critiqued current media messages. In particular, students used the medium of digital storytelling to build and revise identities for purposes of rememory, reinvention, and cultural remixing. We provide a detailed online account of the digital stories and composing processes of the students through the same multimedia genre that the students were asked to use, that of digital storytelling

The physiological cost of wearing the propellant handler's ensemble at the Kennedy Space Center

The potential for exposure to toxins used in the propulsion systems of spacecraft dictates the use of a whole body protective suit, the Propellant Handler's Ensemble (PHE) during preflight preparation and launching. The weight, structure, and operating parameters of the PHE may be expected to have a significant impact upon the metabolic, cardiovascular, and thermal responses of the user, especially during ambient temperature extremes and high workload situations. Four male subjects participated in tests in -7, 23, and 43 C (20, 74, and 110 F) environments in two versions of the PHE, the autonomous backpack (BP) and the hoseline (HL) supplied configuration. Measurements included heart rate (HR) rectal temperature, four skin temperatures, oxygen (O2), and carbon dioxide (CO2) in the helmet area, interior suit temperature, and suit pressure. Exercise metabolism was estimated from HR, PHE weight, and treadmill speed and grade. The HR responses between each PHE configuration were not statistically different. As a percentage of HR maximum, the mean values were 79 percent (COLD), 84 percent (LAB), and 90 percent (HOT). Helmet O2 and CO2 levels were correlated with percent HR max (P less than 0.001). Rectal temperatures were similar for each PHE configuration, except in the HOT exposure where the BP version exceeded the HL configuration (P less than 0.05). In nearly every instance the HR was driven to moderately high levels, the supplied respiratory gases were not optimum, and thermal adversity was a primary stressor. Our findings suggest that medical and physical fitness standards, along with operational restrictions, should be imposed upon PHE users to avoid situations that could adversely affect the worker

Absolute velocity measurements in sunspot umbrae

In sunspot umbrae, convection is largely suppressed by the strong magnetic field. Previous measurements reported on negligible convective flows in umbral cores. Based on this, numerous studies have taken the umbra as zero reference to calculate Doppler velocities of the ambient active region. To clarify the amount of convective motion in the darkest part of umbrae, we directly measured Doppler velocities with an unprecedented accuracy and precision. We performed spectroscopic observations of sunspot umbrae with the Laser Absolute Reference Spectrograph (LARS) at the German Vacuum Tower Telescope. A laser frequency comb enabled the calibration of the high-resolution spectrograph and absolute wavelength positions. A thorough spectral calibration, including the measurement of the reference wavelength, yielded Doppler shifts of the spectral line Ti i 5713.9 {\AA} with an uncertainty of around 5 m s-1. The measured Doppler shifts are a composition of umbral convection and magneto-acoustic waves. For the analysis of convective shifts, we temporally average each sequence to reduce the superimposed wave signal. Compared to convective blueshifts of up to -350 m s-1 in the quiet Sun, sunspot umbrae yield a strongly reduced convective blueshifts around -30 m s-1. {W}e find that the velocity in a sunspot umbra correlates significantly with the magnetic field strength, but also with the umbral temperature defining the depth of the titanium line. The vertical upward motion decreases with increasing field strength. Extrapolating the linear approximation to zero magnetic field reproduces the measured quiet Sun blueshift. Simply taking the sunspot umbra as a zero velocity reference for the calculation of photospheric Dopplergrams can imply a systematic velocity error.Comment: 10 pages, 7 figures, 2 tables, Appendix with 5 figure

A semantic web approach for built heritage representation

In a built heritage process, meant as a structured system of activities aimed at the investigation, preservation, and management of architectural heritage, any task accomplished by the several actors involved in it is deeply influenced by the way the knowledge is represented and shared. In the current heritage practice, knowledge representation and management have shown several limitations due to the difficulty of dealing with large amount of extremely heterogeneous data. On this basis, this research aims at extending semantic web approaches and technologies to architectural heritage knowledge management in order to provide an integrated and multidisciplinary representation of the artifact and of the knowledge necessary to support any decision or any intervention and management activity. To this purpose, an ontology-based system, representing the knowledge related to the artifact and its contexts, has been developed through the formalization of domain-specific entities and relationships between them

Critical conditions for the wetting of soils

The wettability of soil is of great importance for plants and soil biota and in determining whether flooding and soil erosion will occur. The analysis used in common measurements of soil hydrophobicity makes the assumption that water always enters soils if the average contact angle between the soil and water is 90 degrees or lower; these tests have been used for decades. The authors show theoretically and experimentally that water cannot enter many soils unless the contact angle is considerably lower than this, down to approximately 50 degrees. This difference generates serious errors in determining and modeling soil wetting behavior

Comb-calibrated solar spectroscopy through a multiplexed single-mode fiber channel

We investigate a new scheme for astronomical spectrograph calibration using the laser frequency comb at the Solar Vacuum Tower Telescope on Tenerife. Our concept is based upon a single-mode fiber channel, that simultaneously feeds the spectrograph with comb light and sunlight. This yields nearly perfect spatial mode matching between the two sources. In combination with the absolute calibration provided by the frequency comb, this method enables extremely robust and accurate spectroscopic measurements. The performance of this scheme is compared to a sequence of alternating comb and sunlight, and to absorption lines from Earth's atmosphere. We also show how the method can be used for radial-velocity detection by measuring the well-explored 5-minute oscillations averaged over the full solar disk. Our method is currently restricted to solar spectroscopy, but with further evolving fiber-injection techniques it could become an option even for faint astronomical targets.Comment: 21 pages, 11 figures. A video abstract for this paper is available on youtube. For watching the video, please follow https://www.youtube.com/watch?v=oshdZgrt89I . The video abstract is also available for streaming and download on the related article website of New Journal of Physic