Related Studies in Long Term Lithium Battery Stability

The continuing growth of the use of lithium electrochemical systems in a wide variety of both military and industrial applications is primarily a result of the significant benefits associated with the technology such as high energy density, wide temperature operation and long term stability. The stability or long term storage capability of a battery is a function of several factors, each important to the overall storage life and, therefore, each potentially a problem area if not addressed during the design, development and evaluation phases of the product cycle. Design (e.g., reserve vs active), inherent material thermal stability, material compatibility and self-discharge characteristics are examples of factors key to the storability of a power source

Naval Postgraduate School NPSAT1 Small Satellite

Paper presented at the ESA Small Satellite Systems and Services SymposiumThe NPSAT1 mission, conceived and developed by the Naval Postgraduate School (NPS) Space Systems Academic Group (SSAG), is sponsored and executed by the DoD Space Test Program (SMC SDD). The small satellite is manifested for launch aboard the STP-1 Atlas V Mission due to launch in December 2006. The main objective of the NPSAT1 program is to provide educational opportunities for the offi cer students in the Space Systems Curricula at NPS through the design, testing, integration, and fl ight operations of a small satellite. The 82 kg (180 lbs) satellite will be earth-pointing using a novel, low-cost, 3-axis attitude control scheme. NPSAT1 will provide a platform for a number of spacecraft technology experiments, including a lithium-ion battery, a confi gurable, fault-tolerant processor (CFTP) experiment, and fl ight demonstrations of commercial, off-the-shelf (COTS) components such as microelectromechanical systems (MEMS) rate sensors and a digital camera. The spacecraft command and data handling (C&DH) subsystem is NPS-designed, featuring low-power with error-detection-and-correction (EDAC) memory, an ARM720T microprocessor, and running Linux as the operating system. Two other experiments are provided by the Naval Research Laboratory to investigate ionospheric physics. This paper presents an overview of the spacecraft, its subsystems, and the challenges of a small satellite program in a university environment.Naval Postgraduate School, Monterey, California

Paleotsunami Inundation of a Beach Ridge Plain: Cobble Ridge Overtopping and Interridge Valley Flooding in Seaside, Oregon, USA

The Seaside beach ridge plain was inundated by six paleotsunamis during the last ∼2500 years. Large runups (adjusted \u3e10m in height) overtopped seawardmost cobble beach ridges (7m elevation) at ∼1.3 and ∼2.6 ka before present. Smaller paleotsunami (6−8m in height) likely entered the beach plain interior (4-5m elevation) through the paleo-Necanicum bay mouth. The AD 1700 Cascadia paleotsunami had a modest runup (6-7mheight), yet it locally inundated to 1.5 km landward distance. Bed shear stresses (100−3,300 dyne cm−2) are estimated for paleotsunami surges (0.5−2m depths) that flowed down slopes (0.002−0.017 gradient) on the landward side of the cobble beach ridges. Critical entrainment shear stresses of 1,130−1,260 dyne cm−2 were needed to dislodge the largest clasts (26−32 cm diameter) in paleotsunami coulees that were cut (100−200m width) into the landward side of the cobble ridges

Naval Postgraduate School PANSAT: Lessons Learned

AIAA Space 2001 - Conference and Exposition, Albuquerque, NM, August 28-30, 2001The Petite Amateur Navy Satellite (PANSAT) was launched aboard the STS-95 Discovery Shuttle on 29 October 1998. PANSAT was inserted into a circular, low-Earth orbit at an altitude of 550 km and 28.45° inclination on 30 October 1998. PANSAT continues to operate and support the educational mission at NPS even after reaching its two-year design life. The research aspect also continues with the analysis of the accumulated telemetry data, in terms of how well the spacecraft operated over the mission design life. However, the store-and-forward mission using direct sequence spread spectrum was never realized

Inducing Probabilistic Grammars by Bayesian Model Merging

We describe a framework for inducing probabilistic grammars from corpora of positive samples. First, samples are {\em incorporated} by adding ad-hoc rules to a working grammar; subsequently, elements of the model (such as states or nonterminals) are {\em merged} to achieve generalization and a more compact representation. The choice of what to merge and when to stop is governed by the Bayesian posterior probability of the grammar given the data, which formalizes a trade-off between a close fit to the data and a default preference for simpler models (`Occam's Razor'). The general scheme is illustrated using three types of probabilistic grammars: Hidden Markov models, class-based $n$-grams, and stochastic context-free grammars.Comment: To appear in Grammatical Inference and Applications, Second International Colloquium on Grammatical Inference; Springer Verlag, 1994. 13 page

The End of Innocence: The Effect of California\u27s Recreational Use Statue on Children at Play

One hundred years ago, the idea that children deserved special protection from dangerous conditions found on private property was adopted by both the United States and California Supreme Courts. Due to innocence of children and their inability to perceive possible dangers, landowners were required to provide a higher degree of protection to children than adults. This new and revolutionary idea, later to be labeled the attractive nuisance doctrine, was adopted by the Restatement of Torts in what has been called its most effective single section. However, today in California, a recent decisions has reversed a century of development in the law which has provided protection to children. The duty of care required of a landowner towards the children of this state has returned to that which existed over one hundred years ago

A Spectrum of an Extrasolar Planet

Of the over 200 known extrasolar planets, 14 exhibit transits in front of their parent stars as seen from Earth. Spectroscopic observations of the transiting planets can probe the physical conditions of their atmospheres. One such technique can be used to derive the planetary spectrum by subtracting the stellar spectrum measured during eclipse (planet hidden behind star) from the combined-light spectrum measured outside eclipse (star + planet). Although several attempts have been made from Earth-based observatories, no spectrum has yet been measured for any of the established extrasolar planets. Here we report a measurement of the infrared spectrum (7.5--13.2 micron) of the transiting extrasolar planet HD209458b. Our observations reveal a hot thermal continuum for the planetary spectrum, with approximately constant ratio to the stellar flux over this wavelength range. Superposed on this continuum is a broad emission peak centered near 9.65 micron that we attribute to emission by silicate clouds. We also find a narrow, unidentified emission feature at 7.78 micron. Models of these ``hot Jupiter'' planets predict a flux peak near 10 micron, where thermal emission from the deep atmosphere emerges relatively unimpeded by water absorption, but models dominated by water fit the observed spectrum poorly

Effects of beta-alanine supplementation on brain homocarnosine/carnosine signal and cognitive function: an exploratory study

Objectives: Two independent studies were conducted to examine the effects of 28 d of beta-alanine supplementation at 6.4 g d-1 on brain homocarnosine/carnosine signal in omnivores and vegetarians (Study 1) and on cognitive function before and after exercise in trained cyclists (Study 2). Methods: In Study 1, seven healthy vegetarians (3 women and 4 men) and seven age- and sex-matched omnivores undertook a brain 1H-MRS exam at baseline and after beta-alanine supplementation. In study 2, nineteen trained male cyclists completed four 20-Km cycling time trials (two pre supplementation and two post supplementation), with a battery of cognitive function tests (Stroop test, Sternberg paradigm, Rapid Visual Information Processing task) being performed before and after exercise on each occasion. Results: In Study 1, there were no within-group effects of beta-alanine supplementation on brain homocarnosine/carnosine signal in either vegetarians (p = 0.99) or omnivores (p = 0.27); nor was there any effect when data from both groups were pooled (p = 0.19). Similarly, there was no group by time interaction for brain homocarnosine/carnosine signal (p = 0.27). In study 2, exercise improved cognitive function across all tests (P0.05) of beta-alanine supplementation on response times or accuracy for the Stroop test, Sternberg paradigm or RVIP task at rest or after exercise. Conclusion: 28 d of beta-alanine supplementation at 6.4g d-1 appeared not to influence brain homocarnosine/ carnosine signal in either omnivores or vegetarians; nor did it influence cognitive function before or after exercise in trained cyclists