Oxidation of Columbium-Chromium Alloys at Elevated Temperatures

Screening studies of the oxidation characteristics of binary alloys of columbium (Ref. 1) showed that chromium was an additive element worthy of intensive study. The screening studies showed that chromium additions were especially helpful in decreasing the oxidation rate of columbium at 10000deg C and were somewhat less beneficial at 12000deg C. It is the purpose of this investigation to study the oxidation characteristics of binary columbium-chromium alloys in more detail

Beam waveguides in the Deep Space Network

A beam waveguide is a mechanism for guiding electromagnetic radiation from one part of an antenna to another through a series of reflectors. Appropriate placement of reflectors on an antenna allows a beam to be guided around the elevation axis and/or below the alidade. The beam waveguide permits placement of all electronics in a room on the alidade below the elevation axis, or below the alidade; feed horn covers to be protected from the weather; and feed electronics to be in spacious rooms rather than in crowded cones, and always level rather than tipping with change in elevation angle. These factors can lead to lower costs in implementation such as Ka-band, better antenna performance at X-band, more efficient and stable performance of transmitters and receivers, and lower maintenance and operating costs. Studies are underway to determine methods for converting the major antennas of the Deep Space Network (DSN) to beam waveguide operations by 1995

Atomic resolution STM imaging of a twisted single-wall carbon nanotube

We present atomically-resolved STM images of single-wall carbon nanotubes (SWNTs) embedded in a crystalline nanotube rope. Although they may be interpreted as of a chiral nanotube, the images are more consistently explained a an achiral armchair tube with a quenched twist distortion. The existence of quenched twists in SWNTs in ropes might explain the fact that both as-grown bulk nanotube material and individual ropes have insulator-like conductivity at low temperature.Comment: preprint, 4 pages, and 4 gif figure

Vibration/vacuum screening of space lubricants Final report

Evaluation of solid film lubricants for ball bearings in space environment

Strategies For The Replacement Of Historic Bridge Guardrails

Bridges that are designated historic present a special challenge to bridge engineers whenever rehabilitation work or improvements are made to the bridges. Federal and state laws protect historically significant bridges, and railings on these bridges can be subject to protection because of the role they play in aesthetics. Unfortunately, original railings on historic bridges do not typically meet current crash-test requirements and typically do not meet current standards for railing height and size of permitted openings. The objective of this study is to develop strategies that can be used to address existing railings on historic bridges and to develop solutions that meet current design requirements. To achieve this objective, three phases of research were conducted. First, an overview of current practice for addressing historic bridge railings was performed. Second, an investigation was conducted to document historic bridge railings in Indiana. Finally, rehabilitation solutions were developed to address the specific bridge railings found in Indiana. Based on this research, three retrofit strategies were developed which include an inboard railing, curb railing, and a simulated historic railing. These rehabilitation solutions can be used to address historic bridge railings not only in Indiana, but across the country

Aristotle’s \u3ci\u3ePoetics\u3c/i\u3e: A Biologist’s Approach to Tragedy

The paper describes a class that introduces Aristotle’s Poetics from the perspective of his scientific, especially biological, treatises: a systematic analysis of what emotions a tragedy is supposed to elicit and how they are resolved by the audience (homoeopathy). Students read 11 ancient and modern plays and view one film, observing whether his theory of the Tragic explains our responses. The final project includes the writing of a tragic story (not a drama) evincing the students’ own understanding of the Tragic based on the readings

Surface roughness during depositional growth and sublimation of ice crystals

Full version of an earlier discussion paper (Chou et al. 2018)Ice surface properties can modify the scattering properties of atmospheric ice crystals and therefore affect the radiative properties of mixed-phase and cirrus clouds. The Ice Roughness Investigation System (IRIS) is a new laboratory setup designed to investigate the conditions under which roughness develops on single ice crystals, based on their size, morphology and growth conditions (relative humidity and temperature). Ice roughness is quantified through the analysis of speckle in 2-D light-scattering patterns. Characterization of the setup shows that a supersaturation of 20 % with respect to ice and a temperature at the sample position as low as-40 °C could be achieved within IRIS. Investigations of the influence of humidity show that higher supersaturations with respect to ice lead to enhanced roughness and irregularities of ice crystal surfaces. Moreover, relative humidity oscillations lead to gradual ratcheting-up of roughness and irregularities, as the crystals undergo repeated growth-sublimation cycles. This memory effect also appears to result in reduced growth rates in later cycles. Thus, growth history, as well as supersaturation and temperature, influences ice crystal growth and properties, and future atmospheric models may benefit from its inclusion in the cloud evolution process and allow more accurate representation of not just roughness but crystal size too, and possibly also electrification properties.Peer reviewe

When Nature Becomes Natural: Spiritual Catastrophe in Pasolini's "Medea"

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Student Athletics and Honors: Building Relationships

Few university administrators today would argue against having more student athletes applying for and successfully completing honors curricula. Such students are great for PR. But, sad to say, coaches and faculty, at least at tier-1 universities like the University of Washington, are often suspicious of each other’s intentions. Some coaches see too much focus on education as a threat to their team’s success and ultimately their jobs; some faculty see athletes, especially in the revenue sports, as uncommitted to education, exploited by universities, and biding their time in school to enter the lucrative professional careers they believe await them. Yet, there exists a goal that both honors students and student athletes, faculty and coaches, share, a goal that could well provide the basis for beginning a productive relationship, namely the pursuit of excellence. In what follows, we make the case that Honors is uniquely situated to assist in the creative development of the way professors and coaches see student athletes. Our case is based on courses offered to student athletes that were overseen by the UW Honors Program and on the useful exchanges the program developed with Student Athletic Services and Undergraduate Academic Affairs, the unit in which the honors program is housed at the University of Washington. This three-way relationship was not part of a preconceived plan; rather, we followed where circumstances led. What we offer here thus represents observations and suggestions, not a fully developed model

STM Studies of Synthetic Peptide Monolayers

We have used scanning probe microscopy to investigate self-assembled monolayers of chemically synthesized peptides. We find that the peptides form a dense uniform monolayer, above which is found a sparse additional layer. Using scanning tunneling microscopy, submolecular resolution can be obtained, revealing the alpha helices which constitute the peptide. The nature of the images is not significantly affected by the incorporation of redox cofactors (hemes) in the peptides.Comment: 4 pages, 3 figures (4 gifs); to appear in the Proceedings of the XIIth Int. Winterschool on Electronic Properties of Novel Materials "Molecular Nanostructures", Kirchberg/Tyrol, Febr. 199