CFRP truss for the CCAT 25 m diameter submillimeter-wave telescope

CCAT will be a 25 m diameter submillimeter-wave telescope that will operate inside a dome located on Cerro Chajnantor in the Atacama Desert. The telescope must have high aperture efficiency at a wavelength of 350 microns and good performance out to a wavelength of 200 microns. A conceptual design for a carbon fiber reinforced plastic (CFRP) truss and primary reflector support truss has been developed. This design yields a telescope with a net �½ wave front error of <10 microns using a lookup table to adjust the segment actuators to compensate for gravitational deflections. Minor corrections may be required to compensate for the expected 20 C temperature excursions. These can be handled using a coarse lookup table

The Relationship between Parks, Health, Income, and Education in Albuquerque, New Mexico

As resources are becoming scarcer, Southwestern cities are looking for ways to expend less water and money, leading to removal of green spaces. This is happening alongside the current health crisis occurring throughout the United States, which is unfortunate since urban green spaces have been found to improve human health. The purpose of this study, focusing on Albuquerque, New Mexico, is to determine: (1) if those benefits appear to exist in a desert city, and (2) how additional variables, such as income and education, compare with parks regarding impact on community health. A GIS analysis was conducted using park, health, income and education data. The results indicate that while income and education do strongly correlate with certain health indicators, parks also demonstrate a small beneficial relationship with health in relation to chronic obstructive pulmonary disease (COPD), heart disease, and chronic disease

Testing and evaluation of Dacron parachute elements after exposure to ethylene oxide and simulated package loading and heat cycle

Testing Dacron parachute components and assemblies by exposure to ethylene oxide sterilization, simulated package loading, and heat cycl

The importance of the teams in Iowa team-based variable pay pilot project schools

In May 2001, the Iowa legislature enacted Teacher Quality legislation to improve student achievement. This legislation included four components, one of which was the Team-Based Variable Pay Pilot Project (TBVP), which coupled alternative teacher compensation with student achievement.;There has been much research on alternative teacher compensation, which includes recognizing and rewarding teachers as a team, but the research has not focused on the importance of teacher teams. Dianne Chadwick found student and staff achievement were key to the success of TBVP, not variable pay . The researcher found the principals believed the team structure to be the key to the success of TBVP.;The purpose of this qualitative study was to explore the importance of the team by collecting information from all the schools in the pilot project. The researcher used Crow and Pounder\u27s constructs to provide a sketch of the teacher teams. The sketch led to purposeful sampling and a limited number of teacher teams were included in the case study.;The researcher used on-site interviews and observations to probe the degree to which teacher teams exhibited the characteristics of teamness and functioned as a learning community. The researcher identified the strategies used to promote teamness, impact student achievement (student learning), and impact professional growth and development (teacher learning).;The researcher concluded that the team structure and the teams represented the heart of the TBVP Pilot Project. Teachers and principals valued the increased cooperation, collaboration, communication, and shared commitment and credited the teacher teams.;The researcher made a number of recommendations related to traditional and nontraditional teacher teams. The traditional team structure alone was not enough nor were the departments, grade level, and interdisciplinary teams. Iowa\u27s legislators need to continue to fund TBVP in order to further explore the roles the teacher teams play. Principals need to know more about teacher teams in order to create, and recreate as needed, teacher teams that fulfill the promise of teacher teams and serve student and adult needs until every child is successful and every teacher is effective

Visual modulation transfer function as a predictor of acuity

The use of Fourier and modulation transfer techniques implies the ability to characterize an optical system and predict the output resulting from various inputs. In this study, the optical system is defined as a projection system, rear projection screen, and the human eye. A determination of modulation thresholds of visibility for a series of sinusoidal (in transmittance) test objects results after some manipulation in the modulation transfer function of the complete system. This result is then used to predict the subject\u27s ability to resolve conventional acuity challenges. These conventional test objects are then manufactured for projection in the system. Correlation between predicted acuity and observed acuity as tested may now be determined. The result indicates the degree to which optical designers may rely on modulation transfer and fourier techniques to predict the visual performance of a system. Presentation of targets was made using a modified slide projector. Changes in modulation were achieved by addition of a veiling glare projector. Subject response consisted of a forced choice, yes or no, as to whether modulation was perceived in the field of view. Thresholds of perception were defined as that modulation correctly observed 50% of the time. Two-bar targets were produced, and characterized by microdensitometer traces. Using the discrete fourier transform, these targets were convolved with the spread function defined by the M.T.F. Resulting absorption profiles permitted an estimate of image degra dation. When essential details of the object were lost it was predicted that visual resolution would fail. The accuracy of this prediction was tested by presentation of the two bar targets to the subject. Results indicate that while modulation transfer and fourier techniques permit rapid assessment of an optical system, that many factors affect subjective visual response, In testing it was found that while a high degree of correla tion exists between predicted resolution and actual resolution, variability inherent in threshold measurement precludes precision in prediction

CCAT

Star formation, which drives the evolution of baryonic matter in the universe, occurs in the densest regions of the interstellar medium. As a result much of the emergent short wavelength radiation, UV to near IR, is absorbed by intervening dust and reradiated at longer wavelengths, far IR and subillimeter. Indeed the energy density of post primordial extragalactic light is divided equally between these short and long wavelengths, indicating equal amounts of radiation have passed through dusty and optically transparent environments over cosmic time. Comprehensive understanding of the processes of galaxy, star, and planetary formation requires, therefore, high sensitivity and high angular resolution observations, particularly surveys, in the far IR and submillimeter. A consortium led by Cornell and Caltech with JPL is now jointly planning the construction of a 25 m diameter telescope for submillimeter astronomy on a high mountain in northern Chile. This CCAT will combine high sensitivity, a wide field of view, and a broad wavelength range to provide an unprecedented capability for deep, large area, multi-color submillimeter surveys to complement narrow field, high resolution studies with ALMA. CCAT observations will address fundamental themes in contemporary astronomy, notably the formation and evolution of galaxies, the nature of the dark matter and dark energy that comprise most of the content of the universe, the formation of stars and planets, the conditions in circumstellar disks, and the conditions during the early history of the Solar system. The candidate CCAT site, at 5600m in northern Chile, enjoys superb observing conditions. To accommodate large format bolometer cameras, CCAT is designed with a 20 arcmin field of view. CCAT will incorporate closed loop active control of its segmented primary mirror to maintain a half wavefront error of 10 μm rms or less for the entire telescope. Instrumentation under consideration includes both short (650 μm–200 μm) and long (2 mm–750 μm) wavelength bolometer cameras, direct detection spectrometers, and heterodyne receiver arrays. In addition to Cornell and Caltech with JPL, the University of Colorado, the Universities of British Columbia and of Waterloo, the UK Astronomy Technology Centre on behalf of the UK community, and the Universities of Cologne and of Bonn have joined the CCAT consortium. When complete, CCAT will be the largest and most sensitive facility of its class as well as the highest altitude astronomical facility on Earth

Radar studies of the planets

The radar measurements phase of the lunar studies involving reflectivity and topographic mapping of the visible lunar surface was ended in December 1972, but studies of the data and production of maps have continued. This work was supported by Manned Spacecraft Center, Houston. Topographic mapping of the equatorial regions of Mars has been carried out during the period of each opposition since that of 1967. The method comprised extended precise traveling time measurements to a small area centered on the subradar point. As measurements continued, planetary motions caused this point to sweep out extensive areas in both latitude and longitude permitting the development of a fairly extensive topographical map in the equatorial region. Radar observations of Mercury and Venus have also been made over the past few years. Refinements of planetary motions, reflectivity maps and determinations of rotation rates have resulted

Visual Narrative: A Theory and Model for Image-Driven Digital Historiography based on a Case Study of China’s Boxer Uprising (c. 1900)

Digitization that has enabled instant access to vast numbers of archival, historical images, demands a new paradigm for the use of visual imagery in historical research. This thesis proposes a new form of historiography in the digital medium, an image-based narrative mode for authoring and reading history. I propose a digital model for conveying history through the visual record, as an alternative to the printed book. Unlike the quantitative “big data” approach to digital humanities, this research explores visuality itself. In a practice-led approach, the research addresses both aspects of historiography: (1) a method of historical representation; and (2) original historical work on a selected topic. The testbed for historiographic and narrative experiments which led to the model was my case study on the Boxer Uprising in China, c. 1900. While many written histories of the Boxer Uprising exist, I collected a large portion of its extensive visual record for the first time. Sources from around the world, in a variety of media, were assembled into a digital data set that reveals previously unexplored historical themes. A series of visual narratives built in the case study culminated in a proposed “Visual Narrative Field” model. In this model, meaning emerges in the patterns observed between images within a complex visual field. The model vertically integrates three narrative approaches in order to support alternating cognitive modes used to read texts and perceive images. Linear concentration is blended with the non-linear exploration of interactive forms. The model provides historians with a much-needed tool for authoring narrative through relationships between images in a scalable approach. Due to digitization, visual databases are easily assembled, and images are as easily reproduced as written text. The Visual Narrative Field model takes advantage of the characteristics of the newly-digitized visual record, providing a means of authoring visual narrative that can be comprehended without the use of extensive written text. The model thus creates an unprecedented image-based method for performing and presenting historical research

Musical form in non-narrative video

Thesis (M.S.V.S.)--Massachusetts Institute of Technology, Dept. of Architecture, 1986.MICROFICHE COPY AVAILABLE IN ARCHIVES AND ROTCH.Includes bibliographical references (leaves 75-76)."Musical Form in Non- Narrative Video" explores musical structure as a model for visual form over time, specifically in the creation of artistic video. Video is a medium in which sound and image coexist at the source as electronic signals, offering new possibilities of abstract synesthesia. Forms in which neither sight nor sound dominants facilitate a sensory experience of the content. A musical model for abstract form supports an effort to free video from the forward-impelled, linear narrative; to create a form which can be experienced many times on multiple levels. Musical parameters such as meter, dynamics and motivic development are correlated to visual parameters. Their application in my own videotapes is analyzed. Experimental form-generated pieces are outlined. "Aviary" and "Counterpoint" are video scores which present two different approaches to music image composition. A score system in which video and audio can be synchronized via SMPTE Time Code and MIDI Digital Audio Code is examined. Increasing videodisc distribution opens an avenue for serious artistic applications of music- image composition for a home, concert and exhibition medium. The videodisc medium also breaks down the linear impulse in favor of viewer choice with accompanying demands for formal growth.by Ellen Irene Sebring.M.S.V.S