Hoop/column antenna deployment mechanism overview

The hoop/column antenna program is directed toward the development of a cost effective, large area, self deploying reflector antenna system. Large surface area antenna systems are required in future space missions involving improved land communications, Earth resources observation, and the study of intergalactic energy sources. The hoop/column antenna is a concept where a large antenna system can be packaged within the Space Transportation System (Shuttle) payload bay, launched into Earth orbit where it is released either for deployment as an Earth observation or communications antenna, or boosted into deep space as an intergalactic energy probe. Various mechanisms and support structures are described that are required to deploy the hoop, which is used to support the antenna reflective surface, and the column that is used to position the antenna feeds and the reflector. It also describes a proof-of-concept model (15 meters in diameter) that is currently being ground tested to determine the adequacy of the deployment mechanisms

The Greater Sum of Collaboration: Adding Value to Mathematics Education Through Teamwork

The role of a Mathematics Specialist can vary from pre-K through grade 8 schools. One of the most distinguishing factors involves the relationship between the Mathematics Specialists, administrators, and teachers. In this article, we share our experiences in a school culture that supports common language, collective commitments, trust, and transparency. Using this model, we have experienced high levels of teacher professionalism and student success. As lifelong learners, we continually reflect upon our practices and look for ways to meet the needs of our students. This occurs by implementing purposeful meeting structures that allow us to facilitate discussions around mathematics content, lesson planning, assessment results, and student progress. Administrators Brian Butler and Diane Kerr, along with Mathematics Specialists Tracey Hulen and Jennifer Deinhart, have formed a powerful relationship at Mason Crest Elementary School. This is a Title I school with 560 students, pre-K through grade 5, which promotes reflective practices and allows for flexibility and creativity as we continue to strengthen and improve our practices. Together, we share a story of our collaborative journey with teachers and students to create an effective mathematics program that embraces a conceptual learning philosophy. Ultimately there are two kinds of schools: learning-enriched schools and learning impoverished schools. I have yet to see a school where the learning curves ... of the adults were steeped upward and those of the students were not. Teachers and students go hand in hand as learners ... or they don\u27t go at all. [1] Roland Barth, Hand in Hand, We All Lear

Hyponatremia in the 2009 161-km Western States Endurance Run

Purpose:To determine the incidence of exercise-associated hyponatremia (EAH), the associated biochemical measurements and risk factors for EAH, and whether there is an association between postrace blood sodium concentration ([Na+]) and changes in body mass among participants in the 2009 Western States Endurance Run, a 161-km mountain trail run. Methods: Change in body mass, postrace [Na+], and blood creatine phosphokinase (CPK) concentration, and selected runner characteristics were evaluated among consenting competitors. Results: Of the 47 study participants, 14 (30%) had EAH as defined by a postrace [Na+] /L. Postrace [Na+] and percent change in body mass were directly related (r = .30, P = .044), and 50% of those with EAH had body mass losses of 3–6%. EAH was unrelated to age, sex, finish time, or use of nonsteroidal anti-inflammatory drugs during the run, but those with EAH had completed a smaller (P = .03) number of 161-km ultramarathons. The relationship of CPK levels to postrace [Na+] did not reach statistical significance (r = –.25, P = .097). Conclusions: EAH was common (30%) among finishers of this 161-km ultramarathon and it was not unusual for those with EAH to be dehydrated. As such, changes in body mass should not be relied upon in the assessment for EAH during 161-km ultramarathons

Pragmatic Design: A Case Study of Innovation in a Small Software Company

The research question that underpins this paper is ‘What are the novel features of IS design practice ‘in the wild’? In order to help answer this question, a theoretical perspective that focuses on practitioners’ ‘situated practical theory’ in the ‘co-production’ of IS designs is adopted. The context for this study is that firms operating in the IT sector face particular challenges in navigating the complex web of global regulatory requirements. Accordingly, practitioners indicate the need for IT artefacts to informate and help automate compliance processes in organizations. This paper reports on the design of an innovative IT artefact called Compliance-to-Product (C2P), which is argued to be in the vanguard of a new breed of IS called Compliance Knowledge Management Systems (CKMS). The paper describes how this IT artefact was designed by a small-to-medium sized software enterprise, whose design architecture originated in the ‘situated practical theory’ of the company’s founder. However, the findings illustrate that the detailed design was ‘co-produced’ by a network of social actors from collaborating organizations and that this emerged over time. The paper’s concluding observation is that the findings pose a question for design science and the claims for its ability to shape design practice

The Expanded Very Large Array

In almost 30 years of operation, the Very Large Array (VLA) has proved to be a remarkably flexible and productive radio telescope. However, the basic capabilities of the VLA have changed little since it was designed. A major expansion utilizing modern technology is currently underway to improve the capabilities of the VLA by at least an order of magnitude in both sensitivity and in frequency coverage. The primary elements of the Expanded Very Large Array (EVLA) project include new or upgraded receivers for continuous frequency coverage from 1 to 50 GHz, new local oscillator, intermediate frequency, and wide bandwidth data transmission systems to carry signals with 16 GHz total bandwidth from each antenna, and a new digital correlator with the capability to process this bandwidth with an unprecedented number of frequency channels for an imaging array. Also included are a new monitor and control system and new software that will provide telescope ease of use. Scheduled for completion in 2012, the EVLA will provide the world research community with a flexible, powerful, general-purpose telescope to address current and future astronomical issues.Comment: Added journal reference: published in Proceedings of the IEEE, Special Issue on Advances in Radio Astronomy, August 2009, vol. 97, No. 8, 1448-1462 Six figures, one tabl

A Third Planet Orbiting HIP 14810

We present new precision radial velocities and a three-planet Keplerian orbit fit for the V = 8.5, G5 V star HIP 14810. We began observing this star at Keck Observatory as part of the N2K Planet Search Project. Wright et al. (2007) announced the inner two planets to this system, and subsequent observations have revealed the outer planet planet and the proper orbital solution for the middle planet. The planets have minimum masses of 3.9, 1.3, and 0.6 M_Jup and orbital periods of 6.67, 147.7, and 952 d, respectively. We have numerically integrated the family of orbital solutions consistent with the data and find that they are stable for at least 10^6 yr. Our photometric search shows that the inner planet does not transit.Comment: ApJL, accepte

Improving measurements of SF6 for the study of atmospheric transport and emissions

Sulfur hexafluoride (SF6) is a potent greenhouse gas and useful atmospheric tracer. Measurements of SF6 on global and regional scales are necessary to estimate emissions and to verify or examine the performance of atmospheric transport models. Typical precision for common gas chromatographic methods with electron capture detection (GC-ECD) is 1–2%. We have modified a common GC-ECD method to achieve measurement precision of 0.5% or better. Global mean SF6 measurements were used to examine changes in the growth rate of SF6 and corresponding SF6 emissions. Global emissions and mixing ratios from 2000–2008 are consistent with recently published work. More recent observations show a 10% decline in SF6 emissions in 2008–2009, which seems to coincide with a decrease in world economic output. This decline was short-lived, as the global SF6 growth rate has recently increased to near its 2007–2008 maximum value of 0.30±0.03 pmol mol−1 (ppt) yr−1 (95% C.L.)

The Delta-Delta Intermediate State in 1S0 Nucleon-Nucleon Scattering From Effective Field Theory

We examine the role of the Delta-Delta intermediate state in low energy NN scattering using effective field theory. Theories both with and without pions are discussed. They are regulated with dimensional regularization and MSbar subtraction. We find that the leading effects of the Delta-Delta state can be absorbed by a redefinition of the contact terms in a theory with nucleons only. It does not remove the requirement of a higher dimension operator to reproduce data out to moderate momentum. The explicit decoupling of the Delta-Delta state is shown for the theory without pions.Comment: 16 pages, 3 figures, uses harvma