134 research outputs found
Nuclear reactor power as applied to a space-based radar mission
The SP-100 Project was established to develop and demonstrate feasibility of a space reactor power system (SRPS) at power levels of 10's of kilowatts to a megawatt. To help determine systems requirements for the SRPS, a mission and spacecraft were examined which utilize this power system for a space-based radar to observe moving objects. Aspects of the mission and spacecraft bearing on the power system were the primary objectives of this study; performance of the radar itself was not within the scope. The study was carried out by the Systems Design Audit Team of the SP-100 Project
Testing of Milliwatt Power Source Components
A milliwatt power source (MPS) has been developed to satisfy the requirements of several potential solar system exploration missions. The MPS is a small power source consisting of three major components: a space qualified heat source (RHU), a thermopile (thermoelectric converter or TEC) and a container to direct the RHU heat to the TEC. Thermopiles from Hi-Z Technology, Inc. of San Diego and the Institute of Thermoelectricity of Chernivtsi Ukraine suitable for the MPS were tested and shown to perform as expected, producing 40 mW of power with a temperature difference of about 170°C. Such thermopiles were successfully life tested for up to a year. A MPS container designed and built by Swales Aerospace was tested with both a TEC simulator and actual TEC. The Swales unit, tested under dynamic vacuum, provided less temperature difference than anticipated, such that the TEC produced 20 mW of power with heat input equivalent to a RHU
The Student Movement Volume 106 Issue 18: Spring, Strings, and Jeans: AU Composers Take the Stage
HUMANS
Freshman Spotlight Interview: George Isaac, Interviewed by: Lauren Kim
From Berrien Springs to Beirut - A Spring Break Mission Trip, Interviewed by: Irina Gagiu
Student Workers Across Campus, Interviewed by: Grace No
ARTS & ENTERTAINMENT
Creative Spotlight: In Passing Podcast, Interviewed by: Megan Napod
Signal Boost: Inventing Anna, Gabriela Francisco
The 94th Academy Awards: Desert Sci-Fi, Kooky Westers, & much more, Solana Campbell
NEWS
Gym Class Heroes Challenge, Sion Kim
Sunday Music Series: Andrews University Composers Concert, Andrew Pak
The Election, Chris Ngugi
IDEAS
Is Carbon Capture the Key to Stopping Climate Change?. Lyle Goulbourne
Learning to Focus: Navigating the Weird, Wacky Mind of A Sould Blessed with ADD or ADHD, Angelina Nesmith
Silenced Chalk: Unheard Women in STEM, Alexander Navarro
PULSE
Hamil Day: Making a Holiday, T Bruggeman
Spring at Andrews, Isabella Koh
Unplugging from Social Media, Gloria Oh
THE LAST WORD
You Can\u27t Give What You Don\u27t Have: Fill Your Cup, Megan Napodhttps://digitalcommons.andrews.edu/sm-106/1017/thumbnail.jp
Miniaturized Radioisotope Solid State Power Sources
Abstract. Electrical power requirements for the next generation of deep space missions cover a wide range from the kilowatt to the milliwatt. Several of these missions call for the development of compact, low weight, long life, rugged power sources capable of delivering a few milliwatts up to a couple of watts while operating in harsh environments. Advanced solid state thermoelectric microdevices combined with radioisotope heat sources and energy storage devices such as capacitors are ideally suited for these applications. By making use of macroscopic film technology, microgenerators operating across relatively small temperature differences can be conceptualized for a variety of high heat flux or low heat flux heat source configurations. Moreover, by shrinking the size of the thermoelements and increasing their number to several thousands in a single structure, these devices can generate high voltages even at low power outputs that are more compatible with electronic components. Because the miniaturization of state-of-the-art thermoelectric module technology based on Bi 2 Te 3 alloys is limited due to mechanical and manufacturing constraints, we are developing novel microdevices using integrated-circuit type fabrication processes, electrochemical deposition techniques and high thermal conductivity substrate materials. One power source concept is based on several thermoelectric microgenerator modules that are tightly integrated with a 1.1W Radioisotope Heater Unit. Such a system could deliver up to 50mW of electrical power in a small lightweight package of approximately 50 to 60g and 30cm 3 . An even higher degree of miniaturization and high specific power values (mW/mm 3 ) can be obtained when considering the potential use of radioisotope materials for an alpha-voltaic or a hybrid thermoelectric/alpha-voltaic power source. Some of the technical challenges associated with these concepts are discussed in this paper
Digital transformations and the archival nature of surrogates
Large-scale digitization is generating extraordinary collections of visual
and textual surrogates, potentially endowed with transcendent long-term cultural
and research values. Understanding the nature of digital surrogacy is a substantial
intellectual opportunity for archival science and the digital humanities, because of
the increasing independence of surrogate collections from their archival sources.
The paper presents an argument that one of the most significant requirements for the
long-term access to collections of digital surrogates is to treat digital surrogates as
archival records that embody traces of their fluid lifecycles and therefore are worthy
of management and preservation as archives. It advances a theory of the archival
nature of surrogacy founded on longstanding notions of archival quality, the traces
of their source and the conditions of their creation, and the functional ââwork of the
archive.ââ The paper presents evidence supporting a ââsecondary provenanceââ
derived from re-digitization, re-ingestion of multiple versions, and de facto
replacement of the original sources. The design of the underlying research that
motivates the paper and summary findings are reported separately. The research has
been supported generously by the US Institute of Museum and Library Services.Institute for Museum and Library ServicesPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/111825/1/J26 Conway Digital Transformations 2014-pers.pdfDescription of J26 Conway Digital Transformations 2014-pers.pdf : Main articl
Biomass and Burning Characteristics of Sugar Pine Cones
We investigated the physical and burning characteristics of sugar pine (Pinus lambertiana Douglas) cones and their contribution to woody surface fuel loadings. Field sampling was conducted at the Yosemite Forest Dynamics Plot (YFDP), a 25.6 ha mapped study plot in Yosemite National Park, California, USA. We developed a classification system to describe sugar pine cones of different sizes and decay conditions, and examined differences among cone classes in biomass, bulk density, flame length, burning time, consumption, and relative contribution to surface fuel loads. Sugar pine cones comprised 601 kg ha-1 of surface fuels. Mature cones comprised 54% of cone biomass, and aborted juvenile cones accounted for 44%. Cone biomass, diameter, and bulk density differed among cone condition classes, as did burning characteristics (one-way ANOVA, P \u3c 0.001 in all cases). Flame lengths ranged from 5 cm to 94 cm for juvenile cones, and 71 cm to 150 cm for mature cones. Our results showed that the developmental stage at which sugar pine cones become surface fuels determines their potential contribution to surface fire behavior in Sierra Nevada mixed-conifer forests. Sugar pine cones burn with greater flame lengths and flame times than the cones of other North American fire-tolerant pine species studied to date, indicating that cones augment the surface fire regime of sugar pine forests, and likely do so to a greater degree than do cones of other pine species
A user's guide to the Encyclopedia of DNA elements (ENCODE)
The mission of the Encyclopedia of DNA Elements (ENCODE) Project is to enable the scientific and medical communities to interpret the human genome sequence and apply it to understand human biology and improve health. The ENCODE Consortium is integrating multiple technologies and approaches in a collective effort to discover and define the functional elements encoded in the human genome, including genes, transcripts, and transcriptional regulatory regions, together with their attendant chromatin states and DNA methylation patterns. In the process, standards to ensure high-quality data have been implemented, and novel algorithms have been developed to facilitate analysis. Data and derived results are made available through a freely accessible database. Here we provide an overview of the project and the resources it is generating and illustrate the application of ENCODE data to interpret the human genome
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