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Sample records for sats higher volume

  1. Flight Technical Error Analysis of the SATS Higher Volume Operations Simulation and Flight Experiments

    Science.gov (United States)

    Williams, Daniel M.; Consiglio, Maria C.; Murdoch, Jennifer L.; Adams, Catherine H.

    2005-01-01

    This paper provides an analysis of Flight Technical Error (FTE) from recent SATS experiments, called the Higher Volume Operations (HVO) Simulation and Flight experiments, which NASA conducted to determine pilot acceptability of the HVO concept for normal operating conditions. Reported are FTE results from simulation and flight experiment data indicating the SATS HVO concept is viable and acceptable to low-time instrument rated pilots when compared with today s system (baseline). Described is the comparative FTE analysis of lateral, vertical, and airspeed deviations from the baseline and SATS HVO experimental flight procedures. Based on FTE analysis, all evaluation subjects, low-time instrument-rated pilots, flew the HVO procedures safely and proficiently in comparison to today s system. In all cases, the results of the flight experiment validated the results of the simulation experiment and confirm the utility of the simulation platform for comparative Human in the Loop (HITL) studies of SATS HVO and Baseline operations.

  2. Preliminary Validation of the Small Aircraft Transportation System Higher Volume Operations (SATS HVO) Concept

    Science.gov (United States)

    Williams, Daniel; Consiglio, Maria; Murdoch, Jennifer; Adams, Catherine

    2004-01-01

    This document provides a preliminary validation of the Small Aircraft Transportation System (SATS) Higher Volume Operations (HVO) concept for normal conditions. Initial results reveal that the concept provides reduced air traffic delays when compared to current operations without increasing pilot workload. Characteristic to the SATS HVO concept is the establishment of a newly defined area of flight operations called a Self-Controlled Area (SCA) which would be activated by air traffic control (ATC) around designated non-towered, non-radar airports. During periods of poor visibility, SATS pilots would take responsibility for separation assurance between their aircraft and other similarly equipped aircraft in the SCA. Using onboard equipment and simple instrument flight procedures, they would then be better able to approach and land at the airport or depart from it. This concept would also require a new, ground-based automation system, typically located at the airport that would provide appropriate sequencing information to the arriving aircraft. Further validation of the SATS HVO concept is required and is the subject of ongoing research and subsequent publications.

  3. The Small Aircraft Transportation System (SATS), Higher Volume Operations (HVO) Concept and Research

    Science.gov (United States)

    Baxley, B.; Williams, D.; Consiglio, M.; Adams, C.; Abbott, T.

    2005-01-01

    The ability to conduct concurrent, multiple aircraft operations in poor weather at virtually any airport offers an important opportunity for a significant increase in the rate of flight operations, a major improvement in passenger convenience, and the potential to foster growth of operations at small airports. The Small Aircraft Transportation System, (SATS) Higher Volume Operations (HVO) concept is designed to increase capacity at the 3400 non-radar, non-towered airports in the United States where operations are currently restricted to one-in/one-out procedural separation during low visibility or ceilings. The concept s key feature is that pilots maintain their own separation from other aircraft using air-to-air datalink and on-board software within the Self-Controlled Area (SCA), an area of flight operations established during poor visibility and low ceilings around an airport without Air Traffic Control (ATC) services. While pilots self-separate within the SCA, an Airport Management Module (AMM) located at the airport assigns arriving pilots their sequence based on aircraft performance, position, winds, missed approach requirements, and ATC intent. The HVO design uses distributed decision-making, safe procedures, attempts to minimize pilot and controller workload, and integrates with today's ATC environment. The HVO procedures have pilots make their own flight path decisions when flying in Instrument Metrological Conditions (IMC) while meeting these requirements. This paper summarizes the HVO concept and procedures, presents a summary of the research conducted and results, and outlines areas where future HVO research is required. More information about SATS HVO can be found at http://ntrs.nasa.gov.

  4. SATS HVO Concept Validation Experiment

    Science.gov (United States)

    Consiglio, Maria; Williams, Daniel; Murdoch, Jennifer; Adams, Catherine

    2005-01-01

    A human-in-the-loop simulation experiment was conducted at the NASA Langley Research Center s (LaRC) Air Traffic Operations Lab (ATOL) in an effort to comprehensively validate tools and procedures intended to enable the Small Aircraft Transportation System, Higher Volume Operations (SATS HVO) concept of operations. The SATS HVO procedures were developed to increase the rate of operations at non-towered, non-radar airports in near all-weather conditions. A key element of the design is the establishment of a volume of airspace around designated airports where pilots accept responsibility for self-separation. Flights operating at these airports, are given approach sequencing information computed by a ground based automated system. The SATS HVO validation experiment was conducted in the ATOL during the spring of 2004 in order to determine if a pilot can safely and proficiently fly an airplane while performing SATS HVO procedures. Comparative measures of flight path error, perceived workload and situation awareness were obtained for two types of scenarios. Baseline scenarios were representative of today s system utilizing procedure separation, where air traffic control grants one approach or departure clearance at a time. SATS HVO scenarios represented approaches and departure procedures as described in the SATS HVO concept of operations. Results from the experiment indicate that low time pilots were able to fly SATS HVO procedures and maintain self-separation as safely and proficiently as flying today's procedures.

  5. The Revised SAT Score and Its Potential Benefits for the Admission of Minority Students to Higher Education

    Science.gov (United States)

    Santelices, Maria Veronica; Wilson, Mark

    2015-01-01

    This paper investigates the predictive validity of the Revised SAT (R-SAT) score, proposed by Freedle (2003) as an alternative to compensate minority students for the potential harm caused by the relationship between item difficulty and ethnic DIF observed in the SAT. The R-SAT score is the score minority students would have received if only the…

  6. Near-real-time Arctic sea ice thickness and volume from CryoSat-2

    Science.gov (United States)

    Tilling, Rachel L.; Ridout, Andy; Shepherd, Andrew

    2016-09-01

    Timely observations of sea ice thickness help us to understand the Arctic climate, and have the potential to support seasonal forecasts and operational activities in the polar regions. Although it is possible to calculate Arctic sea ice thickness using measurements acquired by CryoSat-2, the latency of the final release data set is typically 1 month due to the time required to determine precise satellite orbits. We use a new fast-delivery CryoSat-2 data set based on preliminary orbits to compute Arctic sea ice thickness in near real time (NRT), and analyse this data for one sea ice growth season from October 2014 to April 2015. We show that this NRT sea-ice-thickness product is of comparable accuracy to that produced using the final release CryoSat-2 data, with a mean thickness difference of 0.9 cm, demonstrating that the satellite orbit is not a critical factor in determining sea ice freeboard. In addition, the CryoSat-2 fast-delivery product also provides measurements of Arctic sea ice thickness within 3 days of acquisition by the satellite, and a measurement is delivered, on average, within 14, 7 and 6 km of each location in the Arctic every 2, 14 and 28 days respectively. The CryoSat-2 NRT sea-ice-thickness data set provides an additional constraint for short-term and seasonal predictions of changes in the Arctic ice cover and could support industries such as tourism and transport through assimilation in operational models.

  7. Point-to-Point! Validation of the Small Aircraft Transportation System Higher Volume Operations Concept

    Science.gov (United States)

    Williams, Daniel M.

    2006-01-01

    Described is the research process that NASA researchers used to validate the Small Aircraft Transportation System (SATS) Higher Volume Operations (HVO) concept. The four phase building-block validation and verification process included multiple elements ranging from formal analysis of HVO procedures to flight test, to full-system architecture prototype that was successfully shown to the public at the June 2005 SATS Technical Demonstration in Danville, VA. Presented are significant results of each of the four research phases that extend early results presented at ICAS 2004. HVO study results have been incorporated into the development of the Next Generation Air Transportation System (NGATS) vision and offer a validated concept to provide a significant portion of the 3X capacity improvement sought after in the United States National Airspace System (NAS).

  8. Do later wake times and increased sleep duration of 12th graders result in more studying, higher grades, and improved SAT/ACT test scores?

    Science.gov (United States)

    Cole, James S

    2016-09-01

    The aim of this study was to investigate the relationship between sleep duration, wake time, and hours studying on high school grades and performance on the Scholastic Aptitude Test (SAT)/ American College Testing (ACT) college entrance exams. Data were collected from 13,071 recently graduated high school seniors who were entering college in the fall of 2014. A column proportions z test with a Bonferroni adjustment was used to analyze proportional differences. Analysis of covariance (ANCOVA) was used to examine mean group differences. Students who woke up prior to 6 a.m. and got less than 8 h of sleep (27 %) were significantly more likely to report studying 11 or more hours per week (30 %), almost double the rate compared to students who got more than 8 h of sleep and woke up the latest (16 %). Post hoc results revealed students who woke up at 7 a.m. or later reported significantly higher high school grades than all other groups (p SAT/ACT scores were from the group that woke up after 7 a.m. but got less than 8 h sleep (M = 1099.5). Their scores were significantly higher than all other groups. This study provides additional evidence that increased sleep and later wake time are associated with increased high school grades. However, this study also found that students who sleep the longest also reported less studying and lower SAT/ACT scores.

  9. International Relations. International Perspectives on Higher Education Research. Volume 3

    Science.gov (United States)

    Tight, Malcolm, Ed.

    2005-01-01

    This is the third volume of International Perspectives on Higher Education Research, a series which aims to feature something of the variety of research being undertaken into higher education systems and issues outside of North America. The theme of this volume is International Relations, or how students, academics, universities and higher…

  10. High Data Rates for AubieSat-2 A & B, Two CubeSats Performing High Energy Science in the Upper Atmosphere

    Science.gov (United States)

    Sims, William H.

    2015-01-01

    This paper will discuss a proposed CubeSat size (3 Units / 6 Units) telemetry system concept being developed at Marshall Space Flight Center (MSFC) in cooperation with Auburn University. The telemetry system incorporates efficient, high-bandwidth communications by developing flight-ready, low-cost, PROTOFLIGHT software defined radio (SDR) payload for use on CubeSats. The current telemetry system is slightly larger in dimension of footprint than required to fit within a 0.75 Unit CubeSat volume. Extensible and modular communications for CubeSat technologies will provide high data rates for science experiments performed by two CubeSats flying in formation in Low Earth Orbit. The project is a collaboration between the University of Alabama in Huntsville and Auburn University to study high energy phenomena in the upper atmosphere. Higher bandwidth capacity will enable high-volume, low error-rate data transfer to and from the CubeSats, while also providing additional bandwidth and error correction margin to accommodate more complex encryption algorithms and higher user volume.

  11. SATS 14

    DEFF Research Database (Denmark)

    Frølunde, Lisbeth; Andreasen, Lars Birch; Hansen, Susanne Pihl

    SATS14 projektet har drejet sig om at undersøge mulighederne i at kunne tilbyde en særlig indsats til de produktionsskoleelever, der har brug for det, så vidt muligt lokalt på deres skole. Projektets formål har været at indhente erfaringer med at tilbyde elever på 14 produktionsskoler på Sjælland...... mål. SATS14 kan dermed ses i en større social sammenhæng. Der er en stigende erkendelse af behovet for initiativer til at hjælpe de elever, der oplever psykiske vanskeligheder. I forordet til en rapport fra Undervisningsministeriet om erhvervsuddannelser beskrives målet: ”95 procent af en...... ungdomsårgang i 2015 skal gennemføre en ungdomsuddannelse… For at opfylde regeringens mål… er det nødvendigt med en særlig indsats for at fastholde de unge, som begynder i en uddannelse, herunder også de bogligt svage” (Kirkegaard og Nielsen, 2008). Da SATS14 projektet startede, var der ikke megen opmærksomhed...

  12. Higher vs. lower fluid volume for septic shock

    DEFF Research Database (Denmark)

    Smith, Søren H; Perner, Anders

    2012-01-01

    ABSTRACT: INTRODUCTION: Patients with septic shock require fluid, but the optimum amount is unknown. Therefore we assessed patient characteristics and outcome associated with fluid volume in unselected patients with septic shock including those with three days of shock. METHODS: We conducted...... a prospective, multicenter, observational study of all adult patients with septic shock during a 3-month study period at six general ICUs: three in university hospitals and three in regional hospitals. After day 1 and 3 of shock, patients were divided into two groups according to the overall median fluid...... volumes. Characteristics between these groups were compared using non-parametric and Chi-square statistics. RESULTS: The 164 included patients received median 4.0 l (IQR 2.3-6.3) of fluid during the first day of septic shock. Patients receiving higher volumes (> 4.0 l) on day 1 had higher p-lactate (3...

  13. Higher Education: Handbook of Theory and Research, Volume XVI.

    Science.gov (United States)

    Smart, John C., Ed.

    This volume contains essays related to various aspects of higher education, focusing on both educational theory and research. The chapters are: (1) "Apologia pro Vita Mia" (Robert Berdahl); (2) "Varieties of Validity: Quality in Qualitative Research" (Yvonna S. Lincoln); (3) "Academic Freedom and Federal Courts in the 1990s: The Legitimation of…

  14. The Entrepreneurial Domains of American Higher Education. ASHE Higher Education Report, Volume 34, Number 5

    Science.gov (United States)

    Mars, Matthew M.; Metcalf, Amy Scott

    2009-01-01

    This volume draws on a diverse set of literatures to represent the various ways in which entrepreneurship is understood in and applied to higher education. It provides a platform for debate for those considering applications of entrepreneurial principles to academic research and practices. Using academic entrepreneurship in the United States as…

  15. CarbonSat Constellation

    Science.gov (United States)

    Sun, Wei; Tobehn, Carsten; Ernst, Robert; Bovensmann, Heinrich; Buchwitz, Michael; Burrows, John P.; Notholt, John

    1 Carbon dioxide (CO2) and methane (CH4) are the most important manmade greenhouse gases (GHGs) which are driving global climate change. Currently, the CO2 measurements from the ground observing network are still the main sources of information but due to the limited number of measurement stations the coverage is limited. In addition, CO2 monitoring and trading is often based mainly on bottom-up calculations and an independent top down verification is limited due to the lack of global measurement data with local resolution. The first CO2 and CH4 mapping from SCIAMACHY on ENVISAT shows that satellites add important missing global information. Current GHG measurement satellites (GOSAT)are limited either in spatial or temporal resolution and coverage. These systems have to collect data over a year or even longer to produce global regional fluxes products. Conse-quently global, timely, higher spatial resolution and high accuracy measurement are required for: 1. A good understanding of the CO2 and CH4 sources and sinks for reliable climate predic-tion; and 2. Independent and transparent verification of accountable sources and sinks in supporting Kyoto and upcoming protocols The CarbonSat constellation idea comes out the trade off of resolution and swath width during CarbonSat mission definition studies. In response to the urgent need to support the Kyoto and upcoming protocols, a feasibility study has been carried out. The proposed solution is a constellation of five CarbonSat satellites in 614km LTAN 13:00, which is able to provide global, daily CO2 and CH4 measurement everywhere on the Earth with high spatial resolution 2 × 2 km and low uncertainty lt;2ppm (CO2) and lt;8ppb (CH4). The unique global daily measurement capability significantly increases the number of cloud free measurements, which enables more reliable services associated with reduced uncertainty, e.g. to 0.15ppm (CO2) per month in 10km and even more timely products. The CarbonSat Constellation in

  16. Improved retrieval of land ice topography from CryoSat-2 data and its impact for volume-change estimation of the Greenland Ice Sheet

    DEFF Research Database (Denmark)

    Nilsson, Johan; Gardner, Alex; Sørensen, Louise Sandberg

    2016-01-01

    A new methodology for retrieval of glacier and ice sheet elevations and elevation changes from CryoSat-2 data is presented. Surface elevations and elevation changes determined using this approach show significant improvements over ESA's publicly available CryoSat-2 elevation product (L2 Baseline......-B). The results are compared to near-coincident airborne laser altimetry from NASA's Operation IceBridge and seasonal height amplitudes from the Ice, Cloud, and Elevation Satellite (ICESat). Applying this methodology to CryoSat-2 data collected in interferometric synthetic aperture mode (SIN) over the high......-relief regions of the Greenland Ice Sheet we find an improvement in the root-mean-square error (RMSE) of 27 and 40% compared to ESA's L2 product in the derived elevation and elevation changes, respectively. In the interior part of the ice sheet, where CryoSat-2 operates in low-resolution mode (LRM), we find...

  17. A survey of SAT solver

    Science.gov (United States)

    Gong, Weiwei; Zhou, Xu

    2017-06-01

    In Computer Science, the Boolean Satisfiability Problem(SAT) is the problem of determining if there exists an interpretation that satisfies a given Boolean formula. SAT is one of the first problems that was proven to be NP-complete, which is also fundamental to artificial intelligence, algorithm and hardware design. This paper reviews the main algorithms of the SAT solver in recent years, including serial SAT algorithms, parallel SAT algorithms, SAT algorithms based on GPU, and SAT algorithms based on FPGA. The development of SAT is analyzed comprehensively in this paper. Finally, several possible directions for the development of the SAT problem are proposed.

  18. Pilot study: whole body manual subcutaneous adipose tissue (SAT) therapy improved pain and SAT structure in women with lipedema.

    Science.gov (United States)

    Herbst, Karen L; Ussery, Christopher; Eekema, Alyna

    2017-09-20

    Background Lipedema is a common painful subcutaneous adipose tissue (SAT) disorder in women affecting the limbs. SAT therapy is a manual therapy to improve soft tissue quality. Objective Determine if SAT therapy improves pain and structure of lipedema SAT. Design Single arm prospective pilot study. Setting Academic medical center. Patients Seven women, 46 ± 5 years, weight 90 ± 19 kg, with lipedema. Intervention Twelve 90-min SAT therapy sessions over 4 weeks. Outcomes Dual X-ray absorptiometry (DXA) scans, SAT ultrasound (Vevo 2100), leg volumetrics, skin caliper assessment, tissue exam, weight, resting metabolic rate, pain assessment, lower extremity functional scale (LEFS) and body shape questionnaire (BSQ) at baseline and end of study. Results Weight, resting metabolic rate and BSQ did not change significantly. Limb fat over total body fat mass (p = 0.08) and trunk fat over total body mass trended down from baseline (p = 0.08) by DXA. Leg volume and caliper assessments in eight of nine areas (p SAT structure in some subjects. Side effects included pain, bruising, itching, swelling and gastroesophageal reflux disease. All women said they would recommend SAT therapy to other women with lipedema. Limitations Small number of subjects. Conclusion SAT therapy in 4 weeks improved tissue structure, perceived leg function, and volume although shape was not affected. While side effects of SAT therapy were common, all women felt the therapy was beneficial.

  19. TechEdSat Nano-Satellite Series Fact Sheet

    Science.gov (United States)

    Murbach, Marcus; Martinez, Andres; Guarneros Luna, Ali

    2014-01-01

    TechEdSat-3p is the second generation in the TechEdSat-X series. The TechEdSat Series uses the CubeSat standards established by the California Polytechnic State University Cal Poly), San Luis Obispo. With typical blocks being constructed from 1-unit (1U 10x10x10 cm) increments, the TechEdSat-3p has a 3U volume with a 30 cm length. The project uniquely pairs advanced university students with NASA researchers in a rapid design-to-flight experience lasting 1-2 semesters.The TechEdSat Nano-Satellite Series provides a rapid platform for testing technologies for future NASA Earth and planetary missions, as well as providing students with an early exposure to flight hardware development and management.

  20. Higher Education: Handbook of Theory and Research. Volumes III [and] IV.

    Science.gov (United States)

    Smart, John C., Ed.

    Two volumes of a handbook on theory and research in higher education are presented. The 11 papers included in Volume III are as follows: "Qualitative Research Methods in Higher Education" (R. Crowson); "Bricks and Mortar: Architecture and the Study of Higher Education" (J. Thelin and J. Yankovich); "Enrollment Demand Models and Their Policy Uses…

  1. SAT math prep course

    CERN Document Server

    Kolby, Jeff

    2011-01-01

    Comprehensive Prep for SAT Math Every year, students pay 1,000 and more to test prep companies to prepare for the math section of the new SAT. Now you can get the same preparation in a book. Features: * Comprehensive Review: Twenty-three chapters provide complete review of SAT math. * Practice: Includes 164 examples and more than 500 exercises! Arranged from easy to medium to hard to very hard. * Diagnostic Test: The diagnostic test measures your strengths and weaknesses and directs you to areas you need to study more. * Performance: If your target is a 700+ score, this is the book!

  2. Higher BMI is associated with higher expiratory airflow normalised for lung volume (FEF25-75/FVC) in COPD.

    Science.gov (United States)

    Abston, Eric; Comellas, Alejandro; Reed, Robert Michael; Kim, Victor; Wise, Robert A; Brower, Roy; Fortis, Spyridon; Beichel, Reinhard; Bhatt, Surya; Zabner, Joseph; Newell, John; Hoffman, Eric A; Eberlein, Michael

    2017-01-01

    The obesity paradox in chronic obstructive pulmonary disease (COPD), whereby patients with higher body mass index (BMI) fare better, is poorly understood. Higher BMIs are associated with lower lung volumes and greater lung elastic recoil, a key determinant of expiratory airflow. The forced expiratory flow (25-75) (FEF25-75)/forced vital capacity (FVC) ratio reflects effort-independent expiratory airflow in the context of lung volume and could be modulated by BMI. We analysed data from the COPDGene study, an observational study of 10 192 subjects, with at least a 10 pack-year smoking history. Data were limited to subjects with BMI 20-40 kg/m(2) (n=9222). Subjects were stratified according to forced expiratory volume in 1 s (FEV1) (%predicted)-quintiles. In regression analyses and Cox proportional hazard models, we analysed the association between BMI, the FEF25-75/FVC ratio, the imaging phenotype, COPD exacerbations, hospitalisations and death. There was no correlation between BMI and FEV1(%predicted). However, a higher BMI is correlated with a higher FEF25-75/FVC ratio. In CT scans, a higher BMI was associated with less emphysema and less air trapping. In risk-adjusted models, the quintile with the highest FEF25-75/FVC ratio was associated with a 46% lower risk of COPD exacerbations (OR 0.54, pBMI was not independently associated with these outcomes. A higher BMI is associated with lower lung volumes and higher expiratory airflows when normalised for lung volume, as quantified by the FEF25-75/FVC ratio. A higher FEF25-75/FVC ratio is associated with a lower risk of COPD exacerbations and death and might quantify functional aspects of the paradoxical effect of higher BMIs on COPD.

  3. SmallSat Database

    Science.gov (United States)

    Petropulos, Dolores; Bittner, David; Murawski, Robert; Golden, Bert

    2015-01-01

    The SmallSat has an unrealized potential in both the private industry and in the federal government. Currently over 70 companies, 50 universities and 17 governmental agencies are involved in SmallSat research and development. In 1994, the U.S. Army Missile and Defense mapped the moon using smallSat imagery. Since then Smart Phones have introduced this imagery to the people of the world as diverse industries watched this trend. The deployment cost of smallSats is also greatly reduced compared to traditional satellites due to the fact that multiple units can be deployed in a single mission. Imaging payloads have become more sophisticated, smaller and lighter. In addition, the growth of small technology obtained from private industries has led to the more widespread use of smallSats. This includes greater revisit rates in imagery, significantly lower costs, the ability to update technology more frequently and the ability to decrease vulnerability of enemy attacks. The popularity of smallSats show a changing mentality in this fast paced world of tomorrow. What impact has this created on the NASA communication networks now and in future years? In this project, we are developing the SmallSat Relational Database which can support a simulation of smallSats within the NASA SCaN Compatability Environment for Networks and Integrated Communications (SCENIC) Modeling and Simulation Lab. The NASA Space Communications and Networks (SCaN) Program can use this modeling to project required network support needs in the next 10 to 15 years. The SmallSat Rational Database could model smallSats just as the other SCaN databases model the more traditional larger satellites, with a few exceptions. One being that the smallSat Database is designed to be built-to-order. The SmallSat database holds various hardware configurations that can be used to model a smallSat. It will require significant effort to develop as the research material can only be populated by hand to obtain the unique data

  4. Analysis of Buried Dielectric Objects Using Higher-Order MoM for Volume Integral Equations

    DEFF Research Database (Denmark)

    Kim, Oleksiy S.; Meincke, Peter; Breinbjerg, Olav

    2004-01-01

    A higher-order method of moments (MoM) is applied to solve a volume integral equation for dielectric objects in layered media. In comparison to low-order methods, the higher-order MoM, which is based on higher-order hierarchical Legendre vector basis functions and curvilinear hexahedral elements...

  5. Exploring Our Solar System with CubeSats and NanoSats

    Science.gov (United States)

    Freeman, Anthony; Norton, Charles

    2015-01-01

    The Jet Propulsion Laboratory (JPL) is NASA's lead center for robotic exploration of our solar system. We are known for our large, flagship missions, such as Voyager, which gave humanity its first close look at Jupiter and Saturn; and the Mars Rovers, which have excited millions worldwide with their daring landing exploits. Less familiar to those outside NASA may be our role in developing the Kepler mission, which has discovered more than 2000 planets around other stars; or the recently launched Soil Moisture Active Passive (SMAP) mission, one of many JPL Earth Science missions. A recent JPL initiative has emphasized low cost missions that use rapidly evolving technology developed for CubeSats and NanoSat s to explore our solar system. Costs are significantly lower (by one or two orders of magnitude) than for conventional JPL missions, and development time is also significantly shorter. At present 21 such CubeSat flight projects are under way at the laboratory with various partners : some in flight, some in development, some in advanced formulation. Four are planned as deep space missions. To succeed in exploring deep space CubeSat/NanoSat missions have to address several challenges: the more severe radiation environment, communications and navigation at a distance, propulsion, and packaging of instruments that can return valuable science into a compact volume/mass envelope. Instrument technologies, including cameras, magnetometers, spectrometers, radiometers, and even radars are undergoing miniaturization to fit on these smaller platforms. Other key technologies are being matured for smallsats and NanoSats in deep space, including micro -electric propulsion, compact radio (and optical) communications, and onboard data reduction. This paper will describe missions that utilize these developments including the first two deep space CubeSats (INSPIRE), planned for launch in 2017; the first pair of CubeSats to be sent to another planet (MARCO), manifested with the In

  6. Barron's SAT math workbook

    CERN Document Server

    Leff MS, Lawrence S

    2016-01-01

    This completely revised edition reflects all of the new questions and question types that will appear on the new SAT, scheduled to be administered in Spring 2016. Includes hundreds of revised math questions and answer explanations, math strategies, test-taking tips, and much more.

  7. Solution of volume-surface integral equations using higher-order hierarchical Legendre basis functions

    DEFF Research Database (Denmark)

    Kim, Oleksiy S.; Meincke, Peter; Breinbjerg, Olav

    2007-01-01

    The problem of electromagnetic scattering by composite metallic and dielectric objects is solved using the coupled volume-surface integral equation (VSIE). The method of moments (MoM) based on higher-order hierarchical Legendre basis functions and higher-order curvilinear geometrical elements...

  8. A Generalization of SAT and #SAT for Robust Policy Evaluation

    Science.gov (United States)

    2014-06-30

    unless the polynomial hierarchy collapses to ΣP2 (a corollary of Dell et al. [2012] and Karp and Lipton [1982]). Proof. Suppose #∃SAT reduces to #P . Then...Klieber, J. Marques-Silva, and E. Clarke. Solving qbf with counterexample guided refinement. In SAT, pages 114–128. Springer, 2012. R.M. Karp and R. Lipton

  9. SAT predicts GPA better for high ability subjects: Implications for Spearman's Law of Diminishing Returns.

    Science.gov (United States)

    Coyle, Thomas; Snyder, Anissa; Pillow, David; Kochunov, Peter

    2011-04-01

    This research examined the predictive validity of the SAT (formerly, the Scholastic Aptitude Test) for high and low ability groups. SAT scores and college GPAs were obtained from the 1997 National Longitudinal Survey of Youth. Subjects were classified as high or low ability by g factor scores from the Armed Services Vocational Aptitude Battery. SAT correlations with GPA were higher for high than low ability subjects. SAT g loadings (i.e., SAT correlations with g) were equivalent for both groups. This is the first study to show that the predictive validity of the SAT varies for ability groups that differ in g. The results contradict a presumption, based on Spearman's Law of Diminishing Returns, that a test's predictive validity should be lower for high ability subjects. Further research is needed to identify factors that contribute to the predictive validity of the SAT for groups that differ in g.

  10. An intelligent system approach to higher-dimensional classification of volume data.

    Science.gov (United States)

    Tzeng, Fan-Yin; Lum, Eric B; Ma, Kwan-Liu

    2005-01-01

    In volume data visualization, the classification step is used to determine voxel visibility and is usually carried out through the interactive editing of a transfer function that defines a mapping between voxel value and color/opacity. This approach is limited by the difficulties in working effectively in the transfer function space beyond two dimensions. We present a new approach to the volume classification problem which couples machine learning and a painting metaphor to allow more sophisticated classification in an intuitive manner. The user works in the volume data space by directly painting on sample slices of the volume and the painted voxels are used in an iterative training process. The trained system can then classify the entire volume. Both classification and rendering can be hardware accelerated, providing immediate visual feedback as painting progresses. Such an intelligent system approach enables the user to perform classification in a much higher dimensional space without explicitly specifying the mapping for every dimension used. Furthermore, the trained system for one data set may be reused to classify other data sets with similar characteristics.

  11. World-volume effective theory for higher-dimensional black holes.

    Science.gov (United States)

    Emparan, Roberto; Harmark, Troels; Niarchos, Vasilis; Obers, Niels A

    2009-05-15

    We argue that the main feature behind novel properties of higher-dimensional black holes, compared to four-dimensional ones, is that their horizons can have two characteristic lengths of very different size. We develop a long-distance world-volume effective theory that captures the black hole dynamics at scales much larger than the short scale. In this limit the black hole is regarded as a blackfold: a black brane (possibly boosted locally) whose world volume spans a curved submanifold of the spacetime. This approach reveals black objects with novel horizon geometries and topologies more complex than the black ring, but more generally it provides a new organizing framework for the dynamics of higher-dimensional black holes.

  12. The Relationship between SAT® Scores and Retention to the Second Year: 2008 SAT Validity Sample. Statistical Report 2012-1

    Science.gov (United States)

    Mattern, Krista D.; Patterson, Brian F.

    2012-01-01

    The College Board formed a research consortium with four-year colleges and universities to build a national higher education database with the primary goal of validating the revised SAT®, which consists of three sections: critical reading (SAT-CR), mathematics (SAT-M), and writing (SAT-W), for use in college admission. A study by Mattern and…

  13. The Relationship between SAT Scores and Retention to the Second Year: Replication with 2009 SAT Validity Sample. Statistical Report 2011-3

    Science.gov (United States)

    Mattern, Krista D.; Patterson, Brian F.

    2012-01-01

    The College Board formed a research consortium with four-year colleges and universities to build a national higher education database with the primary goal of validating the revised SAT for use in college admission. A study by Mattern and Patterson (2009) examined the relationship between SAT scores and retention to the second year of college. The…

  14. Small Sat Analysis Laboratory Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Develop Small Satellite Analysis Laboratory (SatLab): A simulation-of-simulations framework to integrate component and engineering simulations into a single larger...

  15. TechEdSat Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The overall goal of the Technical Education Satellite (TechEdSat) is to employ a small spacecraft to evaluate, demonstrate, and validate two new technologies for...

  16. Propulsion for CubeSats

    Science.gov (United States)

    Lemmer, Kristina

    2017-05-01

    At present, very few CubeSats have flown in space featuring propulsion systems. Of those that have, the literature is scattered, published in a variety of formats (conference proceedings, contractor websites, technical notes, and journal articles), and often not available for public release. This paper seeks to collect the relevant publically releasable information in one location. To date, only two missions have featured propulsion systems as part of the technology demonstration. The IMPACT mission from the Aerospace Corporation launched several electrospray thrusters from Massachusetts Institute of Technology, and BricSAT-P from the United States Naval Academy had four micro-Cathode Arc Thrusters from George Washington University. Other than these two missions, propulsion on CubeSats has been used only for attitude control and reaction wheel desaturation via cold gas propulsion systems. As the desired capability of CubeSats increases, and more complex missions are planned, propulsion is required to accomplish the science and engineering objectives. This survey includes propulsion systems that have been designed specifically for the CubeSat platform and systems that fit within CubeSat constraints but were developed for other platforms. Throughout the survey, discussion of flight heritage and results of the mission are included where publicly released information and data have been made available. Major categories of propulsion systems that are in this survey are solar sails, cold gas propulsion, electric propulsion, and chemical propulsion systems. Only systems that have been tested in a laboratory or with some flight history are included.

  17. CubeSat Cloud: A framework for distributed storage, processing and communication of remote sensing data on cubesat clusters

    Science.gov (United States)

    Challa, Obulapathi Nayudu

    CubeSat Cloud is a novel vision for a space based remote sensing network that includes a collection of small satellites (including CubeSats), ground stations, and a server, where a CubeSat is a miniaturized satellite with a volume of a 10x10x10 cm cube and has a weight of approximately 1 kg. The small form factor of CubeSats limits the processing and communication capabilities. Implemented and deployed CubeSats have demonstrated about 1 GHz processing speed and 9.6 kbps communication speed. A CubeSat in its current state can take hours to process a 100 MB image and more than a day to downlink the same, which prohibits remote sensing, considering the limitations in ground station access time for a CubeSat. This dissertation designs an architecture and supporting networking protocols to create CubeSat Cloud, a distributed processing, storage and communication framework that will enable faster execution of remote sensing missions on CubeSat clusters. The core components of CubeSat Cloud are CubeSat Distributed File System, CubeSat MapMerge, and CubeSat Torrent. The CubeSat Distributed File System has been created for distributing of large amounts of data among the satellites in the cluster. Once the data is distributed, CubeSat MapReduce has been created to process the data in parallel, thereby reducing the processing load for each CubeSat. Finally, CubeSat Torrent has been created to downlink the data at each CubeSat to a distributed set of ground stations, enabling faster asynchronous downloads. Ground stations send the downlinked data to the server to reconstruct the original image and store it for later retrieval. Analysis of the proposed CubeSat Cloud architecture was performed using a custom-designed simulator, called CubeNet and an emulation test bed using Raspberry Pi devices. Results show that for cluster sizes ranging from 5 to 25 small satellites, faster download speeds up to 4 to 22 times faster - can be achieved when using CubeSat Cloud, compared to a

  18. Adipocyte nuclei captured from VAT and SAT.

    Science.gov (United States)

    Ambati, Suresh; Yu, Ping; McKinney, Elizabeth C; Kandasamy, Muthugapatti K; Hartzell, Diane; Baile, Clifton A; Meagher, Richard B

    2016-01-01

    Obesity-related comorbidities are thought to result from the reprogramming of the epigenome in numerous tissues and cell types, and in particular, mature adipocytes within visceral and subcutaneous adipose tissue, VAT and SAT. The cell-type specific chromatin remodeling of mature adipocytes within VAT and SAT is poorly understood, in part, because of the difficulties of isolating and manipulating large fragile mature adipocyte cells from adipose tissues. We constructed MA-INTACT (Mature Adipocyte-Isolation of Nuclei TAgged in specific Cell Types) mice using the adiponectin (ADIPOQ) promoter (ADNp) to tag the surface of mature adipocyte nuclei with a reporter protein. The SUN1mRFP1Flag reporter is comprised of a fragment of the nuclear transmembrane protein SUN1, the fluorescent protein mRFP1, and three copies of the Flag epitope tag. Mature adipocyte nuclei were rapidly and efficiently immuno-captured from VAT and SAT (MVA and MSA nuclei, respectively), of MA-INTACT mice. MVA and MSA nuclei contained 1,000 to 10,000-fold higher levels of adipocyte-specific transcripts, ADIPOQ, PPARg2, EDNRB, and LEP, relative to uncaptured nuclei, while the latter expressed higher levels of leukocyte and endothelial cell markers IKZF1, RETN, SERPINF1, SERPINE1, ILF3, and TNFA. MVA and MSA nuclei differentially expressed several factors linked to adipogenesis or obesity-related health risks including CEBPA, KLF2, RETN, SERPINE1, and TNFA. The various nuclear populations dramatically differentially expressed transcripts encoding chromatin remodeler proteins regulating DNA cytosine methylation and hydroxymethylation (TETs, DNMTs, TDG, GADD45s) and nucleosomal histone modification (ARID1A, KAT2B, KDM4A, PRMT1, PRMT5, PAXIP1). Remarkably, MSA and MVA nuclei expressed 200 to 1000-fold higher levels of thermogenic marker transcripts PRDM16 and UCP1. The MA-INTACT mouse enables a simple way to perform cell-type specific analysis of highly purified mature adipocyte nuclei from VAT and SAT

  19. Effects of a hyperbaric environment on subcutaneous adipose tissue topography (SAT-top).

    Science.gov (United States)

    Möller, Reinhard; Horejsi, Renate; Tafeit, Erwin; Fraidl, Michaela; Dietmaier, Gabriele; Anegg, Udo; Klemen, Huberta; Wallner-Liebmann, Sandra

    2010-12-01

    The physiological reactions of the body in scuba diving situation can be simulated in a pressure chamber by increasing the ambient pressure. In this study the influence of a hyperbaric environment of 6 bar on the changes of the subcutaneous adipose tissue (SAT) thicknesses on different body sites in 68 voluntary men with undersea diving experience was investigated. Measurements of SAT-topography (SAT-Top) were performed with the optical device Lipometer before and after hyperbaric exposure. We observed a significant increase of the SAT-layers of the upper body zones, upper abdomen (+24.5%), lower abdomen (+21%) and front chest (+19%) after hyperbaric exposure. This increase of volume can be assumed to the nitrogen accumulation in fat cells at increased ambient pressures. In conclusion we describe for the first time in detail the influence of a hyperbaric environment on quantitative and topographic changes of SAT.

  20. SmallSats, Iodine Propulsion Technology, Applications to Low-Cost Lunar Missions, and the Iodine Satellite (iSAT) Project

    Science.gov (United States)

    Dankanich, John W.

    2014-01-01

    Closing Remarks: ?(1) SmallSats hold significant potential for future low cost high value missions; (2) Propulsion remains a key limiting capability for SmallSats that Iodine can address: High ISP * Density for volume constrained spacecraft; Indefinite quiescence, unpressurized and non-hazardous as a secondary payload; (3) Iodine enables MicroSat and SmallSat maneuverability: Enables transfer into high value orbits, constellation deployment and deorbit; (4) Iodine may enable a new class of planetary and exploration class missions: Enables GTO launched secondary spacecraft to transit to the moon, asteroids, and other interplanetary destinations for approximately 150 million dollars full life cycle cost including the launch; (5) ESPA based OTVs are also volume constrained and a shift from xenon to iodine can significantly increase the transfer vehicle change in volume capability including transfers from GTO to a range of Lunar Orbits; (6) The iSAT project is a fast pace high value iodine Hall technology demonstration mission: Partnership with NASA GRC and NASA MSFC with industry partner - Busek; (7) The iSAT mission is an approved project with PDR in November of 2014 and is targeting a flight opportunity in FY17.

  1. The Relationship between SAT Scores and Retention to the Third Year: 2006 Cohort. Statistical Report

    Science.gov (United States)

    Mattern, Krista D.; Patterson, Brian F.

    2010-01-01

    Results show that SAT performance is related to third year retention rates. Even after controlling for student and institutional characteristics, returners had higher SAT total scores than non-returners, and the performance gap is not due to differences in the demographic makeup of the two groups. Furthermore, while differences in retention can be…

  2. The SAT® and SAT Subject Tests™: Discrepant Scores and Incremental Validity. Research Report 2012-2

    Science.gov (United States)

    Kobrin, Jennifer L.; Patterson, Brian F.

    2012-01-01

    This study examines student performance on the SAT and SAT Subject Tests in order to identify groups of students who score differently on these two tests, and to determine whether certain demographic groups score higher on one test compared to the other. Discrepancy scores were created to capture individuals' performance differences on the…

  3. COLD-SAT dynamic model

    Science.gov (United States)

    Adams, Neil S.; Bollenbacher, Gary

    1992-01-01

    This report discusses the development and underlying mathematics of a rigid-body computer model of a proposed cryogenic on-orbit liquid depot storage, acquisition, and transfer spacecraft (COLD-SAT). This model, referred to in this report as the COLD-SAT dynamic model, consists of both a trajectory model and an attitudinal model. All disturbance forces and torques expected to be significant for the actual COLD-SAT spacecraft are modeled to the required degree of accuracy. Control and experimental thrusters are modeled, as well as fluid slosh. The model also computes microgravity disturbance accelerations at any specified point in the spacecraft. The model was developed by using the Boeing EASY5 dynamic analysis package and will run on Apollo, Cray, and other computing platforms.

  4. SAT predicts GPA better for high ability subjects: Implications for Spearman’s Law of Diminishing Returns

    Science.gov (United States)

    Coyle, Thomas; Snyder, Anissa; Pillow, David; Kochunov, Peter

    2011-01-01

    This research examined the predictive validity of the SAT (formerly, the Scholastic Aptitude Test) for high and low ability groups. SAT scores and college GPAs were obtained from the 1997 National Longitudinal Survey of Youth. Subjects were classified as high or low ability by g factor scores from the Armed Services Vocational Aptitude Battery. SAT correlations with GPA were higher for high than low ability subjects. SAT g loadings (i.e., SAT correlations with g) were equivalent for both groups. This is the first study to show that the predictive validity of the SAT varies for ability groups that differ in g. The results contradict a presumption, based on Spearman’s Law of Diminishing Returns, that a test’s predictive validity should be lower for high ability subjects. Further research is needed to identify factors that contribute to the predictive validity of the SAT for groups that differ in g. PMID:21562615

  5. CubeSat quantum communications mission

    Energy Technology Data Exchange (ETDEWEB)

    Oi, Daniel K.L. [University of Strathclyde, SUPA Department of Physics, Glasgow (United Kingdom); University of Strathclyde, Strathclyde Space Institute, Glasgow (United Kingdom); Ling, Alex [National University of Singapore, Centre for Quantum Technologies, Singapore (Singapore); National University of Singapore, Dept. of Physics, Singapore (Singapore); Vallone, Giuseppe; Villoresi, Paolo [Universita degli Studi di Padova, Dipartimento di Ingegneria dell' Informazione, Padova (Italy); Greenland, Steve; Kerr, Emma [University of Strathclyde, Advanced Space Concepts Laboratory, Mechanical and Aerospace Engineering, Glasgow (United Kingdom); Macdonald, Malcolm [Technology and Innovation Centre, Scottish Centre of Excellence in Satellite Applications, Glasgow (United Kingdom); Weinfurter, Harald [Ludwig-Maximilians-Universitaet, Department fuer Physik, Munich (Germany); Kuiper, Hans [Delft University of Technology, Space Systems Engineering, Aerospace Engineering, Delft (Netherlands); Charbon, Edoardo [AQUA, EPFL, Lausanne (Switzerland); Delft University of Technology, Delft (Netherlands); Ursin, Rupert [Vienna Austrian Academy of Sciences, Institute for Quantum Optics and Quantum Information, Vienna (Austria)

    2017-12-15

    Quantum communication is a prime space technology application and offers near-term possibilities for long-distance quantum key distribution (QKD) and experimental tests of quantum entanglement. However, there exists considerable developmental risks and subsequent costs and time required to raise the technological readiness level of terrestrial quantum technologies and to adapt them for space operations. The small-space revolution is a promising route by which synergistic advances in miniaturization of both satellite systems and quantum technologies can be combined to leap-frog conventional space systems development. Here, we outline a recent proposal to perform orbit-to-ground transmission of entanglement and QKD using a CubeSat platform deployed from the International Space Station (ISS). This ambitious mission exploits advances in nanosatellite attitude determination and control systems (ADCS), miniaturised target acquisition and tracking sensors, compact and robust sources of single and entangled photons, and high-speed classical communications systems, all to be incorporated within a 10 kg 6 litre mass-volume envelope. The CubeSat Quantum Communications Mission (CQuCoM) would be a pathfinder for advanced nanosatellite payloads and operations, and would establish the basis for a constellation of low-Earth orbit trusted-nodes for QKD service provision. (orig.)

  6. The Globalisation Challenge for European Higher Education: Convergence and Diversity, Centres and Peripheries. Higher Education Research and Policy. Volume 4

    Science.gov (United States)

    Zgaga, Pavel, Ed.; Teichler, Ulrich, Ed.; Brennan, John, Ed.

    2013-01-01

    The last decade has marked the European higher education with a particular dynamics. Today, after a decade of a «concerted» policy, national systems look much more convergent but new questions and dilemmas are emerging: about its nature and quality, about real impact of recent reforms in different countries as well as about its future. The book…

  7. Independent Schools and the SAT

    Science.gov (United States)

    Torres, Amada

    2016-01-01

    In September 2015, when the College Board released its average SAT scores for the 2015 graduating class, two details stood out for many educators: (1) the record participation and diversity numbers (close to 1.7 million students took the test, with 50 percent being students of color); and (2) the test's lower average scores compared with previous…

  8. Tensor Network Contractions for #SAT

    Science.gov (United States)

    Biamonte, Jacob D.; Morton, Jason; Turner, Jacob

    2015-09-01

    The computational cost of counting the number of solutions satisfying a Boolean formula, which is a problem instance of #SAT, has proven subtle to quantify. Even when finding individual satisfying solutions is computationally easy (e.g. 2-SAT, which is in ), determining the number of solutions can be #-hard. Recently, computational methods simulating quantum systems experienced advancements due to the development of tensor network algorithms and associated quantum physics-inspired techniques. By these methods, we give an algorithm using an axiomatic tensor contraction language for n-variable #SAT instances with complexity where c is the number of COPY-tensors, g is the number of gates, and d is the maximal degree of any COPY-tensor. Thus, n-variable counting problems can be solved efficiently when their tensor network expression has at most COPY-tensors and polynomial fan-out. This framework also admits an intuitive proof of a variant of the Tovey conjecture (the r,1-SAT instance of the Dubois-Tovey theorem). This study increases the theory, expressiveness and application of tensor based algorithmic tools and provides an alternative insight on these problems which have a long history in statistical physics and computer science.

  9. Increased sympathetic activation in patients with vasovagal syncope is associated with higher mean platelet volume levels.

    Science.gov (United States)

    Kabul, H K; Celik, M; Yuksel, U Ç; Yalcinkaya, E; Gokoglan, Y; Bugan, B; Barcin, C; Celik, T; Iyisoy, A

    2014-01-01

    Vasovagal syncope (VVS) is supposed to be modulated by increased sympathetic tone following an orthostatic maneuver. Increased sympathetic activity may have an important role in mean platelet volume (MPV), either by peripheral activation or by effects on thrombocytopoiesis. We aimed to show the effects of increased sympathetic activity on platelet size in patients with VVS in the present study. Thirty-seven patients with VVS were compared with age- and sex-matched 33 patients without VVS. All patients have undergone 24 hour holter monitoring for heart rate variability (HRV) and time-domain HRV analysis. Blood samples for MPV measurements were taken before 24 hour holter monitoring. Group 1 was consisted of 37 patients with VVS and group 2 was consisted of 33 patients without VVS. We observed that SDNN, SDNN index, SDSD, RMSDD, PNN50 count were significantly lower and MPV was found significantly higher in patients with VVS (p SDSD (r = -0.396), NN50 count (r = -0.395) and RMSDD (r = -0.393). Multivariate regression analysis showed that SDNN was the only independent variable, which had a significant effect on increased MPV level (β = -0.295 , p = 0.016). We found that MPV was closely associated with increased sympathetic activity in patients with VVS. Our analysis supports the hypothesis that alterations in autonomic status might play a role in the development of platelet size.

  10. Integrated Solar-Panel Antenna Array for CubeSats

    Science.gov (United States)

    Baktur, Reyhan

    2016-01-01

    The goal of the Integrated Solar-Panel Antenna Array for CubeSats (ISAAC) project is to design and demonstrate an effective and efficien toptically transparent, high-gain, lightweight, conformal X-band antenna array that is integrated with the solar panels of a CubeSat. The targeted demonstration is for a Near Earth Network (NEN)radio at X-band, but the design can be easilyscaled to other network radios for higher frequencies. ISAAC is a less expensive and more flexible design for communication systemscompared to a deployed dish antenna or the existing integrated solar panel antenna design.

  11. Electro-Optical Payloads and CubeSat Missions for Earth and Space Science

    Science.gov (United States)

    Swenson, C.; Marchant, A.

    2015-12-01

    Small, low-power electro-optical scientific payloads are required if small satellites and CubeSats are to become significant enablers of new science. Although these are just one class of scientific instrumentation they have often played a key role in many scientific discoveries. The most significant advances in Earth and space science, over the next decade are most likely to derive from new observational techniques. The connection between advances in scientific understanding and technology has historically been demonstrated across many disciplines and time. In this paper we present a review of three such sensors and the associated CubeSat missions and scientific investigation enabled. Each mission involves a relatively recently developed small electro-optical sensor which is tightly integrated with the small satellite bus in to a "Science Craft". The first is the NSF funded OPAL mission which makes use of a high-sensitivity, hyper-spectral limb imager to observe the daytime O2 A-band (near 762nm) emission. These observations allow the temperature of the lower thermosphere to be determined and address questions on the energy budget and response of the thermosphere to geomagnetic storms. The second is the MeNISCuS mission Methane Nadir Imaging Spatial-heterodyne CubeSat Spectrometer which is a demonstration of the volume holographic grating (VHG) spatial heterodyne spectrometer developed under a NASA-sponsored STTR contract. Methane (CH4) is the second most important greenhouse gas and although burning methane produces less CO2 than oil or coal, methane's global warming potential is about ~30 times higher. As a result, if methane leak rates are greater than 3-5%, the warming potential will outweigh the benefit of reduced CO2. The sources of such leaks can be discovered using missions like MeNISCuS. The third instrument and mission is SEDI a CubeSat scaled Fabry-Perot spectrometer focused on a narrow band around the OI(630) red line for observing winds in the

  12. From Higher Education To Employment. Volume I: Australia, Austria, Belgium, Germany = De l'enseignement superieur a l'emploi. Volume I: Allemagne, Australie, Autriche, Belgique.

    Science.gov (United States)

    Organisation for Economic Cooperation and Development, Paris (France).

    This volume presents reports on the flows of graduates from higher education and on their entry into working life in Germany, Austria, Belgium, and Australia. Each paper is written according to detailed guidelines designed to assemble information from many sources, to reflect the state of the art, and to illustrate a variety of approaches,…

  13. Higher Fresh Gas Flow Rates Decrease Tidal Volume During Pressure Control Ventilation.

    Science.gov (United States)

    Mohammad, Shazia; Gravenstein, Nikolaus; Gonsalves, Drew; Vasilopoulos, Terrie; Lampotang, Samsun

    2017-05-01

    We observed that increasing fresh gas flow (FGF) decreased exhaled tidal volume (VT) during pressure control ventilation (PCV). A literature search produced no such description whereby unintended VT changes occur with FGF changes during PCV. To model an infant's lungs, 1 lung of a mechanical lung model (Dual Adult TTL 1600; Michigan Instruments, Inc, Grand Rapids, MI) was set at a compliance of 0.0068 L/cm H2O. An Rp50 resistor (27.2 cm H2O/L/s at 15 L/min) simulated normal bronchial resistance. The simulated lung was connected to a pediatric breathing circuit via a 3.5-mm cuffed endotracheal tube. A ventilator with PCV capability (Model 7900; Aestiva, GE Healthcare, Madison, WI) measured exhaled VT, and a flow monitor (NICO; Respironics, Murraysville, PA) measured peak inspiratory flow, positive end-expiratory pressure (PEEP), and peak inspiratory pressure. In PCV mode, exhaled VT displayed by the ventilator at FGF rates of 1, 6, 10, and 15 L/min was manually recorded across multiple ventilator settings. This protocol was repeated for the Avance CS2 anesthesia machine (GE Healthcare). For the Aestiva, higher FGF rates in PCV mode decreased exhaled VT. Exhaled VT for FGFs of 1, 6, 10, and 15 L/min were on average 48, 34.9, 16.5, and 10 mL, respectively, at ventilator settings of inspiratory pressure of 10 cm H2O, PEEP of 0 cm H2O, and respiratory rate of 20 breaths/min. This is a decrease by up to 27%, 65.6%, and 79.2% when FGFs of 6, 10, and 15 L/min are compared with a FGF of 1 L/min, respectively. In the GE Avance CS2 at the same ventilator settings, VT for FGF rates of 1, 6, 10, and 15 L/min were on average 46, 43, 40.4, and 39.7 mL, respectively. The FGF effect on VT was not as pronounced with the GE Avance CS2 as with the GE Aestiva. FGF has a significant effect on VT during PCV in the Aestiva bellows ventilator, suggesting caution when changing FGF during PCV in infants. Our hypothesis is that at higher FGF rates, an inadvertent PEEP is developed by the flow

  14. Ka Band Parabolic Deployable Antenna (KaPDA) for Interplanetary CubeSat Communications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Ka Band Parabolic Deployable Antenna (KaPDA) for Interplanetary CubeSat Communications allowing moving up from UHF, S or X to get higher gain for a given diameter.

  15. CryoSat: ready to launch (again)

    Science.gov (United States)

    Francis, R.; Wingham, D.; Cullen, R.

    2009-12-01

    Over the last ten years the relationship between climate change and the cryosphere has become increasingly important. Evidence of change in the polar regions is widespread, and the subject of public discussion. During this same ten years ESA has been preparing its CryoSat mission, specifically designed to provide measurements to determine the overall change in the mass balance of all of the ice caps and of change in the volume of sea-ice (rather than simply its extent). In fact the mission was ready for launch in October 2005, but a failure in the launch vehicle led to a loss of the satellite some 6 minutes after launch. The determination to rebuild the satellite and complete the mission was widespread in the relevant scientific, industrial and political entities, and the decision to redirect financial resources to the rebuild was sealed with a scientific report confirming that the mission was even more important in 2005 than at its original selection in 1999. The evolution of the cryosphere since then has emphasised that conclusion. In order to make a meaningful measurement of the secular change of the surface legation of ice caps and the thickness of sea-ice, the accuracy required has been specified as about half of the variation expected due to natural variability, over reasonable scales for the surfaces concerned. The selected technique is radar altimetry. Previous altimeter missions have pioneered the method: the CryoSat instrument has been modified to provide the enhanced capabilities needed to significantly extend the spatial coverage of these earlier missions. Thus the radar includes a synthetic aperture mode which enables the along-track resolution to be improved to about 250 m. This will will allow detection of leads in sea-ice which are narrower than those detected hitherto, so that operation deeper into pack-ice can be achieved with a consequent reduction in errors due to omission. Altimetry over the steep edges of ice caps is hampered by the irregular

  16. Overcoming CubeSat downlink limits with vitamin: A new variable coded modulation protocol

    Science.gov (United States)

    Sielicki, Thomas A.

    Many space missions, including low earth orbit CubeSats, communicate in a highly dynamic environment because of variations in geometry, weather, and interference. At the same time, most missions communicate using fixed channel codes, modulations, and symbol rates, resulting in a constant data rate that does not adapt to the dynamic conditions. When conditions are good, the fixed date rate can be far below the theoretical maximum, called the Shannon limit; when conditions are bad, the fixed data rate may not work at all. To move beyond these fixed communications and achieve higher total data volume from emerging high-tech instruments, this thesis investigates the use of error correcting codes and different modulations. Variable coded modulation (VCM) takes advantage of the dynamic link by transmitting more information when the signal-to-noise ratio (SNR) is high. Likewise, VCM can throttle down the information rate when SNR is low without having to stop all communications. VCM outperforms fixed communications which can only operate at a fixed information rate as long as a certain signal threshold is met. This thesis presents a new VCM protocol and tests its performance in both software and hardware simulations. The protocol is geared towards CubeSat downlinks as complexity is focused in the receiver, while the transmission operations are kept simple. This thesis explores bin-packing as a way to optimize the selection of VCM modes based on expected SNR levels over time. Working end-to-end simulations were created using MATLAB and LabVIEW, while the hardware simulations were done with software defined radios. Results show that a CubeSat using VCM communications will deliver twice the data throughput of a fixed communications system.

  17. Improving Resource-Unaware SAT Solvers

    Science.gov (United States)

    Hölldobler, Steffen; Manthey, Norbert; Saptawijaya, Ari

    The paper discusses cache utilization in state-of-the-art SAT solvers. The aim of the study is to show how a resource-unaware SAT solver can be improved by utilizing the cache sensibly. The analysis is performed on a CDCL-based SAT solver using a subset of the industrial SAT Competition 2009 benchmark. For the analysis, the total cycles, the resource stall cycles, the L2 cache hits and the L2 cache misses are traced using sample based profiling. Based on the analysis, several techniques - some of which have not been used in SAT solvers so far - are proposed resulting in a combined speedup up to 83% without affecting the search path of the solver. The average speedup on the benchmark is 60%. The new techniques are also applied to MiniSAT2.0 improving its runtime by 20% on average.

  18. A Case for Not Going SAT-Optional: Students with Discrepant SAT and HSGPA Performance

    Science.gov (United States)

    Mattern, Krista D.; Shaw, Emily J.; Kobrin, Jennifer L.

    2010-01-01

    Presented at the national conference for the American Educational Research Association (AERA) in 2010. This presentation describes an alternative way of presenting the unique information provided by the SAT over HSGPA, namely examining students with discrepant SAT-HSGPA performance.

  19. Higher programmatic volume in paediatric heart surgery is associated with better early outcomes

    NARCIS (Netherlands)

    Kansy, Andrzej; Ebels, Tjark; Schreiber, Christian; Jacobs, Jeffrey P.; Tobota, Zdzislaw; Maruszewski, Bohdan

    2015-01-01

    Objective: Previous analyses have suggested an association between centre volume and in-hospital mortality, post-operative complications, and mortality in those patients who suffer from a complication. We sought to determine the nature of this association using a multicentre cohort. Methods: All the

  20. Mothership - Affordable Exploration of Planetary Bodies through Individual Nano-Sats and Swarms

    Science.gov (United States)

    DiCorcia, James D.; Ernst, Sebastian M.; Grace, J. Mike; Gump, David P.; Lewis, John S.; Foulds, Craig F.; Faber, Daniel R.

    2015-04-01

    One concept to enable broad participation in the scientific exploration of small bodies is the Mothership mission architecture which delivers third-party nano-sats, experiments, and sensors to a near Earth asteroid or comet. Deep Space Industries' Mothership service includes delivery of nano-sats, communication to Earth, and visuals of the asteroid surface and surrounding area. It allows researchers to house their instruments in a low-cost nano-sat platform that does not require the high-performance propulsion or deep space communication capabilities that otherwise would be required for a solo asteroid mission. This enables organizations with relatively low operating budgets to closely examine an asteroid with highly specialized sensors of their own choosing, while the nano-sats can be built or commissioned by a variety of smaller institutions, companies, or agencies. In addition, the Mothership and its deployed nano-sats can offer a platform for instruments which need to be distributed over multiple spacecraft. The Mothership is designed to carry 10 to 12 nano-sats, based upon a variation of the Cubesat standard, with some flexibility on the specific geometry. The Deep Space Nano-Sat reference design is a 14.5 cm cube, which accomodates the same volume as a traditional 3U Cubesat. This design was found to be more favorable for deep space due to its thermal characteristics. The CubeSat standard was originally designed with operations in low Earth orbit in mind. By deliberately breaking the standard, Deep Space Nano-Sats offer better performance with less chance of a critical malfunction in the more hostile deep space environment. The first mission can launch as early as Q4 2017, with subsequent, regular launches through the 2020's.

  1. MightySat I: In Space

    OpenAIRE

    Braun, Capt. Barbara; Davis, Robert; Itchkawich, Thomas; Goforth, Todd

    1999-01-01

    MightySat is a United States Air Force (USAF) Research Laboratory multi-mission, small satellite program dedicated to providing frequent, inexpensive, on-orbit demonstrations of high-payoff space system technologies. MightySat I, the 140lb pathfmder satellite of the MightySat series, was ejected from the Space Shuttle Endeavor on the 15th of December, 1998. Contact with the satellite was established one hour after ejection, and MightySat I has been performing robustly on-orbit ever since. Thi...

  2. An Operative Complexity Index Shows Higher Volume Hospitals and Surgeons Perform More Complex Adult Spine Deformity Operations.

    Science.gov (United States)

    Paul, Justin C; Lonner, Baron S; Goz, Vadim; Karia, Raj; Toombs, Courtney S; Errico, Thomas J

    2016-11-01

    Though previous studies have shown improved outcomes associated with higher volume surgeons and hospitals, this may not be replicated in ASDS due to case complexity variation. We hypothesized that high-volume surgeons perform more complex surgeries. Therefore, we defined an Operative Complexity Index (OCI), specifically for the National Inpatient Samples (NIS) data, which provides information on in-hospital postoperative complications, to assess rates of adult spine deformity surgery (ASDS) cases as they relate to surgeon and hospital operative volume. The 2001 to 2010 NIS was queried for patients greater than 21 years of age with in-hospital stays, including a spine arthrodesis for a diagnosis of scoliosis. Surgeon and hospital identifiers were used to allocate records into volume quartiles by number of surgeries per year. The OCI was devised considering the number of fusion levels, surgical approach, revision status, and use of osteotomy. The index was validated using blood-loss-related diagnostic and procedural codes. One-way ANOVA assessed continuous measures. Chi-square assessed categorical measures. 141,357 ASDS cases met the inclusion criteria. High-volume surgeons performed a higher rate of longfusions (> 8 levels), revision surgeries, and surgeries requiring osteotomy. The OCI showed weak, but significant, correlation with blood loss values: acute blood loss anemia (r = 0.21) and treatment with blood products (r = 0.12) (p < 0.001). High OCI also was also associated with increased length of stay (r = 0.27) and total charges (r = 0.41) (p < 0.001). The operative complexity index (OCI) for ASDS increases with high-volume surgeons and centers, indicating it can be useful to adjust for surgical invasiveness in the NIS database. Operative complexity must be considered when evaluating patient safety and quality indices among hospitals and surgeons.

  3. Chronicle of Higher Education. Volume 51, Number 28, March 18, 2005

    Science.gov (United States)

    Chronicle of Higher Education, 2005

    2005-01-01

    "Chronicle of Higher Education" presents an abundant source of news and information for college and university faculty members and administrators. This March 18, 2005 issue of "Chronicle of Higher Education" includes the following articles: (1) "After a Loss, Silence?" (Silin, Jonathan G.); (2) "Is Frantz Fanon…

  4. Synthesis of Recent SAT Validity Findings: Trend Data over Time and Cohorts. Research in Review 2014-1

    Science.gov (United States)

    Mattern, Krista D.; Patterson, Brian F.

    2014-01-01

    In March 2005, substantial revisions were made to the SAT, to better align test specifications with K-12 curriculum (Lawrence, Rigol, Van Essen & Jackson, 2003). Over the last five years, the College Board has made a concerted effort to collect higher education outcome data to document evidence of the validity of the SAT for use in college…

  5. CubeSat infrared atmospheric sounder (CIRAS) NASA InVEST technology demonstration

    Science.gov (United States)

    Pagano, Thomas S.

    2017-02-01

    Infrared sounders measure the upwelling radiation of the Earth in the Midwave Infrared (MWIR) and Longwave Infrared (LWIR) region of the spectrum with global daily coverage from space. The observed radiances are assimilated into weather forecast models and used to retrieve lower tropospheric temperature and water vapor for climate studies. There are several operational sounders today including the Atmospheric Infrared Sounder (AIRS) on Aqua, the Crosstrack Infrared Sounder (CrIS) on Suomi NPP and JPSS, and the Infrared Atmospheric Sounding Interferometer (IASI) on the MetOp spacecraft. The CubeSat Infrared Atmospheric Sounder (CIRAS) is a NASA In-flight Validation of Earth Science Technologies (InVEST) program to demonstrate three new instrument technologies in an imaging sounder configuration. The first is a 2D array of High Operating Temperature Barrier Infrared Detector (HOT-BIRD) material, selected for its high uniformity, low cost, low noise and higher operating temperatures than traditional materials. The detectors are hybridized to a commercial ROIC and commercial camera electronics. The second technology is a MWIR Grating Spectrometer (MGS) designed to provide imaging spectroscopy for atmospheric sounding in a CubeSat volume. The MGS employs an immersion grating or grism, has no moving parts, and is based on heritage spectrometers including the OCO- 2. The third technology is a Black Silicon infrared blackbody calibration target. The Black Silicon offers very low reflectance over a broad spectral range on a flat surface and is more robust than carbon nanotubes. JPL will also develop the mechanical, electronic and thermal subsystems for the CIRAS payload. The spacecraft will be a commercially available CubeSat. The integrated system will be a complete 6U CubeSat capable of measuring temperature and water vapor profiles with good lower tropospheric sensitivity. The low cost of CIRAS enables multiple units to be flown to improve temporal coverage or measure 3D

  6. The Social Attribution Task-Multiple Choice (SAT-MC): A Psychometric and Equivalence Study of an Alternate Form.

    Science.gov (United States)

    Johannesen, Jason K; Lurie, Jessica B; Fiszdon, Joanna M; Bell, Morris D

    2013-01-01

    The Social Attribution Task-Multiple Choice (SAT-MC) uses a 64-second video of geometric shapes set in motion to portray themes of social relatedness and intentions. Considered a test of "Theory of Mind," the SAT-MC assesses implicit social attribution formation while reducing verbal and basic cognitive demands required of other common measures. We present a comparability analysis of the SAT-MC and the new SAT-MC-II, an alternate form created for repeat testing, in a university sample (n = 92). Score distributions and patterns of association with external validation measures were nearly identical between the two forms, with convergent and discriminant validity supported by association with affect recognition ability and lack of association with basic visual reasoning. Internal consistency of the SAT-MC-II was superior (alpha = .81) to the SAT-MC (alpha = .56). Results support the use of SAT-MC and new SAT-MC-II as equivalent test forms. Demonstrating relatively higher association to social cognitive than basic cognitive abilities, the SAT-MC may provide enhanced sensitivity as an outcome measure of social cognitive intervention trials.

  7. Preparing for the SAT: A Review

    Science.gov (United States)

    Appelrouth, Jed I.; Zabrucky, Karen M.

    2017-01-01

    In 2016, more than 1.6 million students took the Scholastic Aptitude Test (SAT), a standardized college admissions test (College Board 2016a). Researchers have estimated that 33 percent of students who take the SAT participate in some mode of formal test preparation, such as private tutoring or classes, to prepare for the exam (Buchmann, Condron…

  8. Test anxiety and performance-avoidance goals explain gender differences in SAT-V, SAT-M, and overall SAT scores.

    Science.gov (United States)

    Hannon, Brenda

    2012-11-01

    This study uses analysis of co-variance in order to determine which cognitive/learning (working memory, knowledge integration, epistemic belief of learning) or social/personality factors (test anxiety, performance-avoidance goals) might account for gender differences in SAT-V, SAT-M, and overall SAT scores. The results revealed that none of the cognitive/learning factors accounted for gender differences in SAT performance. However, the social/personality factors of test anxiety and performance-avoidance goals each separately accounted for all of the significant gender differences in SAT-V, SAT-M, and overall SAT performance. Furthermore, when the influences of both of these factors were statistically removed simultaneously, all non-significant gender differences reduced further to become trivial by Cohen's (1988) standards. Taken as a whole, these results suggest that gender differences in SAT-V, SAT-M, and overall SAT performance are a consequence of social/learning factors.

  9. X-Band CubeSat Communication System Demonstration

    Science.gov (United States)

    Altunc, Serhat; Kegege, Obadiah; Bundick, Steve; Shaw, Harry; Schaire, Scott; Bussey, George; Crum, Gary; Burke, Jacob C.; Palo, Scott; O'Conor, Darren

    2015-01-01

    demonstration between a balloon and/or a sounding rocket and a Near Earth Network (NEN) ground system. This paper presents CubeSat communication systems simulation results, analysis of X-band and S-band antennas and RF front-end components, transceiver design, analysis and optimization of space-to-ground communication performance, subsystem development, as well as the test results for an end-to-end X-band CubeSat communication system demonstration. The outcome of this work will be used to pave the way for next generation NEN-compatible X-band CubeSat communication systems to support higher data rates with more advanced modulation and forward error correction (FEC) coding schemes, and to support and attract new science missions at lower cost. It also includes an abbreviated concept of operations for CubeSat users to utilize the NEN, starting from first contact with NASA's communication network and continuing through on-orbit operations.

  10. Recession, Retrenchment, and Recovery: State Higher Education Funding & Student Financial Aid. Volume II: State Profiles

    Science.gov (United States)

    Ambrose, Allison S.; Hines, Edward R.; Hodel, Ross A.; Kelly, Kathleen F.; Mushrush, Christopher E., Pruden, Sheila J.; Vogt, W. Paul

    2006-01-01

    This report is a companion to "Recession, Retrenchment and Recovery: Higher Education Funding and Student Financial Aid" (ED502180). It provides profiles of individual states and their performance on a variety of measures used in the economic and fiscal analysis of the Recession, Retrenchment and Recovery project. The profiles describe the results…

  11. Non-constant volume exponential solutions in higher-dimensional Lovelock cosmologies

    CERN Document Server

    Chirkov, Dmitry; Toporensky, Alexey

    2015-01-01

    In this paper we propose a scheme which allows one to find all possible exponential solutions of special class -- non-constant volume solutions -- in Lovelock gravity in arbitrary number of dimensions and with arbitrate combinations of Lovelock terms. We apply this scheme to (6+1)- and (7+1)-dimensional flat anisotropic cosmologies in Einstein-Gauss-Bonnet and third-order Lovelock gravity to demonstrate how our scheme does work. In course of this demonstration we derive all possible solutions in (6+1) and (7+1) dimensions and compare solutions and their abundance between cases with different Lovelock terms present. As a special but more "physical" case we consider spaces which allow three-dimensional isotropic subspace for they could be viewed as examples of compactification schemes. Our results suggest that the same solution with three-dimensional isotropic subspace is more "probable" to occur in the model with most possible Lovelock terms taken into account, which could be used as kind of anthropic argument...

  12. CryoSat-2: A new perspective on the Cryosphere

    Science.gov (United States)

    Shepherd, A.; Armitage, T.; Briggs, K.; Flament, T.; Hogg, A. E.; McMillan, M.; Muir, A.; Ridout, A.; Sundal, A.; Tilling, R.; Wingham, D.

    2014-12-01

    CryoSat-2 is ESA's first satellite mission dedicated to measuring changes in the polar land ice and sea ice cover. Following its launch in April 2010, we have examined the performance of the instrument over the continental ice sheets of Antarctica and Greenland, the Artic Ocean, and, for the purposes of calibration, over the oceans. We have confirmed the engineering performance at system level of the interferometer demonstrating that it measures across-track surface slopes with a precision of 25 micro-radians and an accuracy of 10 micro-radians, greatly exceeding the pre-launch specifications (100 micro-radians). Over the polar ice sheets, we have examined the performance of the range estimation, and determined the range precision to be 19 cm RMS at 20 Hz. We have examined the retrieval of the phase information over the ice sheets, and found the phase estimates to be robust and little affected by the uncertain ice sheet topography. Based on the calibration of the interferometer, the contribution of the across track slope error is, at 0.4 mm, negligible. Over marine sea ice, we have verified the discrimination of sea ice and ocean lead returns using contemporaneous SAR imagery from ENVISAT, and we have estimated the precision of individual (20 Hz) measurements to be 2 cm. In summary, with the corrected data products, we are able to confirm that the system performance of CryoSat-2 will meet or exceed its specification over the continental and marine ice sheets. This presenetation sumamrises the key outcomes of the mission performance, and presents a series of example case studies where CryoSat-2 data have been applied to study changes in Earth's land and sea ice cover. We show that in 4 years CryoSat has been able to detect changes in the mass of the Antarctic and Greenland ice sheets with an accuracy comparable to that of the past 20 years of conventional satellite altimetry and that important changes have occured in these regions, we show that CryoSat has been able

  13. Lower vs. higher fluid volumes in sepsis-protocol for a systematic review with meta-analysis

    DEFF Research Database (Denmark)

    Meyhoff, T S; Møller, M H; Hjortrup, P B

    2017-01-01

    sequential analysis of randomised clinical trials comparing different strategies to obtain separation in fluid volumes or balances during resuscitation of adult patients with sepsis. We will systematically search the Cochrane Library, MEDLINE, EMBASE, Science Citation Index, BIOSIS and Epistemonikos...... suggested, but the overall benefit or harm in patients with sepsis is unknown. Accordingly, we aim to assess patient-important benefits and harms of lower vs. higher fluid volumes in resuscitation of adult patients with sepsis. METHODS/DESIGN: We will conduct a systematic review with meta-analysis and trial...... for relevant literature. We will follow the recommendations by the Cochrane Collaboration and the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) statement. The risk of systematic errors (bias) and random errors will be assessed, and the overall quality of evidence will be evaluated...

  14. CryoSat-2 Altimetry Applications over Rivers and Lakes

    DEFF Research Database (Denmark)

    Jiang, Liguang; Schneider, Raphael; Andersen, Ole Baltazar

    2017-01-01

    Monitoring the variation of rivers and lakes is of great importance. Satellite radar altimetry is a promising technology to do this on a regional to global scale. Satellite radar altimetry data has been used successfully to observe water levels in lakes and (large) rivers, and has also been...... pattern and provides new opportunities for hydrologic research. The narrow inter-track distance (7.5 km at the equator) makes it possible to monitor many lakes and rivers and SAR mode provides a finer along-track resolution, higher return power and speckle reduction through multi-looks. However, CryoSat-2...... challenges conventional ways of dealing with satellite inland water altimetry data because virtual station time series cannot be directly derived for rivers. We review the CryoSat-2 mission characteristics, data products, and its use and perspectives for inland water applications. We discuss all...

  15. Mass loss of Greenland from GRACE, IceSat and CryoSat

    DEFF Research Database (Denmark)

    Forsberg, René; Sørensen, Louise Sandberg; Fredenslund Levinsen, Joanna

    2013-01-01

    CryoSat data over the Greenland Ice Sheet are used to continue elevation height change data over the Greenland ice sheet, following a decade of detailed monitoring of ice sheet changes with GRACE and IceSat. The combination and validation of the different data for measuring changes is quantified...... by using available airborne lidar data from IceBridge and CryoVEx. There is a special challenge of using CryoSat as fill-in between EnviSat and Sentinel-3 for the longterm measurements of surface elevation changes, a key essential climate variable in the ESA Climate Change Initiative. Another challenge...... is the joint utilization of both altimetry and gravity field change measurements for consistent estimates of regional change patterns. In the paper we analyze GRACE, IceSat and CryoSat data since 2003, and present consistent estimates of overall mass changes with average values around -220 GT/year, showing...

  16. An Optimum Space-to-Ground Communication Concept for CubeSat Platform Utilizing NASA Space Network and Near Earth Network

    Science.gov (United States)

    Wong, Yen F.; Kegege, Obadiah; Schaire, Scott H.; Bussey, George; Altunc, Serhat; Zhang, Yuwen; Patel, Chitra

    2016-01-01

    National Aeronautics and Space Administration (NASA) CubeSat missions are expected to grow rapidly in the next decade. Higher data rate CubeSats are transitioning away from Amateur Radio bands to higher frequency bands. A high-level communication architecture for future space-to-ground CubeSat communication was proposed within NASA Goddard Space Flight Center. This architecture addresses CubeSat direct-to-ground communication, CubeSat to Tracking Data Relay Satellite System (TDRSS) communication, CubeSat constellation with Mothership direct-to-ground communication, and CubeSat Constellation with Mothership communication through K-Band Single Access (KSA).A Study has been performed to explore this communication architecture, through simulations, analyses, and identifying technologies, to develop the optimum communication concepts for CubeSat communications. This paper will present details of the simulation and analysis that include CubeSat swarm, daughter shipmother ship constellation, Near Earth Network (NEN) S and X-band direct to ground link, TDRS Multiple Access (MA) array vs Single Access mode, notional transceiverantenna configurations, ground asset configurations and Code Division Multiple Access (CDMA) signal trades for daughter mother CubeSat constellation inter-satellite crosslink. Results of Space Science X-band 10 MHz maximum achievable data rate study will be summarized. Assessment of Technology Readiness Level (TRL) of current CubeSat communication technologies capabilities will be presented. Compatibility test of the CubeSat transceiver through NEN and Space Network (SN) will be discussed. Based on the analyses, signal trade studies and technology assessments, the functional design and performance requirements as well as operation concepts for future CubeSat end-to-end communications will be derived.

  17. Angiosperms evolved a higher mesophyll surface area per volume to maximize exchange surface under a low CO2 world

    Science.gov (United States)

    Théroux-Rancourt, Guillaume; Mason Earles, J.; Gilbert, Matthew E.; Zwieniecki, Maciej A.; Boyce, C. Kevin; McElrone, Andrew; Brodersen, Craig

    2017-04-01

    Variation in leaf mesophyll structure strongly affects CO2 diffusion and photosynthetic rates. One key trait is the surface of mesophyll cells exposed to intercellular airspace (Sm) which increases mesophyll conductance. Consequently, Sm is a key control of CO2 diffusion among species and genotypes. Using Sm values from the literature (> 200 species with 500 data points) and from our high-resolution X-ray computed tomography (μCT) dataset (currently 117 species), Sm shows little variation from pteridophytes to early angiosperms, while eudicots show the greatest structural diversity. However, Sm increases with total thickness of the mesophyll. By considering the exposed surface of the mesophyll to the intercellular air space (IAS) on a leaf or mesophyll volume (Ames/V mes) rather than leaf area basis (Sm), we demonstrate that angiosperms, and most specifically commelinids and non-basal eudicots, have constructed leaves with more surface per volume, while gymnosperms keep a constant Ames/V mes ratio. Thus, this strong phylogenetic signal suggests that angiosperms have developed IAS properties favoring leaves with higher surface to volume ratio, trait that allowed for the potential of high productivity even as atmospheric CO2 declined over the Cenozoic.

  18. Soft X-ray Focusing Telescope Aboard AstroSat: Design ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy; Volume 38; Issue 2. Soft X-ray Focusing Telescope Aboard AstroSat: Design, Characteristics and Performance. K. P. Singh G. C. Stewart N. J. Westergaard S. Bhattacharayya S. Chandra V. R. Chitnis G. C. Dewangan A. T. Kothare I. M. Mirza K. Mukerjee V. Navalkar ...

  19. Higher body mass index in older adults is associated with lower gray matter volume: implications for memory performance.

    Science.gov (United States)

    Masouleh, Shahrzad Kharabian; Arélin, Katrin; Horstmann, Annette; Lampe, Leonie; Kipping, Judy A; Luck, Tobias; Riedel-Heller, Steffi G; Schroeter, Matthias L; Stumvoll, Michael; Villringer, Arno; Witte, Anja Veronica

    2016-04-01

    Midlife obesity has been associated with increased dementia risk, yet reports on brain structure and function are mixed. We therefore assessed the effects of body mass index (BMI) on gray matter volume (GMV) and cognition in a well-characterized sample of community-dwelled older adults. GMV was measured using 3T-neuroimaging in 617 participants (258 women, 60-80 years, BMI 17-41 kg/m(2)). In addition, cognitive performance and various confounders including hypertension, diabetes, and apolipoprotein E genotype were assessed. A higher BMI correlated significantly with lower GMV in multiple brain regions, including (pre)frontal, temporal, insular and occipital cortex, thalamus, putamen, amygdala, and cerebellum, even after adjusting for confounders. In addition, lower GMV in prefrontal and thalamic areas partially mediated negative effects of (1) higher BMI and (2) higher age on memory performance. We here showed that a higher BMI in older adults is associated with widespread gray matter alterations, irrespective of obesity-related comorbidities and other confounders. Our results further indicate that a higher BMI induces structural alterations that translate into subtle impairments in memory performance in aging. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. AgSat Areas of Interest

    Data.gov (United States)

    Farm Service Agency, Department of Agriculture — The AgSat Areas of Interest map contains area polygons where satellite imagery will be collected for the Farm Service Agency (FSA) to provide imagery coverage for...

  1. NASA 3D Models: CloudSat

    Data.gov (United States)

    National Aeronautics and Space Administration — Launched in April 2006, CloudSat monitors the state of the Earth’s atmosphere and weather with a sophisticated radar system. The instrument, jointly developed with...

  2. PhoneSat - The Smartphone Nanosatellite

    Science.gov (United States)

    Westley, Deborah; Yost, Bruce; Petro, Andrew

    2013-01-01

    PhoneSat 2.4, carried into space on November 19, 2013 aboard a Minotaur I rocket from the Mid-Atlantic Regional Spaceport at NASAs Wallops Flight Facility in Virginia, is the first of the PhoneSat family to use a two-way S-band radio to allow engineers to command the satellite from Earth. This mission also serves as a technology demonstration for a novel attitude determination and control system (ADCS) that establishes and stabilizes the satellites attitude relative to Earth. Unlike the earlier PhoneSats that used a Nexus One, PhoneSat 2.4 uses the Nexus S smartphone, which runs Googles Android operating system, and is made by Samsung Electronics Co., Suwon, So. Korea. The smartphone provides many of the functions needed by the satellite such as a central computer, data memory, ready-made interfaces for communications, navigation and power all pre-assembled in a rugged electronics package.

  3. AgSat Imagery Collection Footprints

    Data.gov (United States)

    Farm Service Agency, Department of Agriculture — The AgSat Imagery Collection Footprints map shows the imagery footprints which have been collected under the USDA satellite blanket purchase agreement. Click on a...

  4. Evolving effective incremental SAT solvers with GP

    OpenAIRE

    Bader, Mohamed; Poli, R.

    2008-01-01

    Hyper-Heuristics could simply be defined as heuristics to choose other heuristics, and it is a way of combining existing heuristics to generate new ones. In a Hyper-Heuristic framework, the framework is used for evolving effective incremental (Inc*) solvers for SAT. We test the evolved heuristics (IncHH) against other known local search heuristics on a variety of benchmark SAT problems.

  5. The Iodine Satellite (iSat) Project Development Towards Critical Design Review

    Science.gov (United States)

    Dankanich, John W.; Calvert, Derek; Kamhawi, Hani; Hickman, Tyler; Szabo, James; Byrne, Lawrence

    2015-01-01

    Despite the prevalence of small satellites in recent years, the systems flown to date have very limited propulsion capability. SmallSats are typically secondary payloads and have significant constraints for volume, mass, and power in addition to limitations on the use of hazardous propellants or stored energy. These constraints limit the options for SmallSat maneuverability. NASA's Space Technology Mission Directorate approved the iodine Satellite flight project for a rapid demonstration of iodine Hall thruster technology in a 12U (cubesat units) configuration under the Small Spacecraft Technology Program. The mission is a partnership between NASA MSFC, NASA GRC, and Busek Co, Inc., with the Air Force supporting the propulsion technology maturation. The team is working towards the critical design review in the final design and fabrication phase of the project. The current design shows positive technical performance margins in all areas. The iSat project is planned for launch readiness in the spring of 2017.

  6. PlumeSat: A Micro-Satellite Based Plume Imagery Collection Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Ledebuhr, A.G.; Ng, L.C.

    2002-06-30

    This paper describes a technical approach to cost-effectively collect plume imagery of boosting targets using a novel micro-satellite based platform operating in low earth orbit (LEO). The plume collection Micro-satellite or PlueSat for short, will be capable of carrying an array of multi-spectral (UV through LWIR) passive and active (Imaging LADAR) sensors and maneuvering with a lateral divert propulsion system to different observation altitudes (100 to 300 km) and different closing geometries to achieve a range of aspect angles (15 to 60 degrees) in order to simulate a variety of boost phase intercept missions. The PlumeSat will be a cost effective platform to collect boost phase plume imagery from within 1 to 10 km ranges, resulting in 0.1 to 1 meter resolution imagery of a variety of potential target missiles with a goal of demonstrating reliable plume-to-hardbody handover algorithms for future boost phase intercept missions. Once deployed on orbit, the PlumeSat would perform a series phenomenology collection experiments until expends its on-board propellants. The baseline PlumeSat concept is sized to provide from 5 to 7 separate fly by data collects of boosting targets. The total number of data collects will depend on the orbital basing altitude and the accuracy in delivering the boosting target vehicle to the nominal PlumeSat fly-by volume.

  7. The Relationship between SAT® Scores and Retention to the Second Year: Replication with the 2010 SAT Validity Sample. Statistical Report 2013-1

    Science.gov (United States)

    Mattern, Krista D.; Patterson, Brian F.

    2013-01-01

    The College Board formed a research consortium with four-year colleges and universities to build a national higher education database with the primary goal of validating the revised SAT for use in college admission. A study by Mattern and Patterson (2009) examined the relationship between SAT scores and retention to the second year. The sample…

  8. SAT: a late NS protein of porcine parvovirus.

    Science.gov (United States)

    Zádori, Zoltán; Szelei, József; Tijssen, Peter

    2005-10-01

    The genomes of all members of the Parvovirus genus were found to contain a small open reading frame (ORF), designated SAT, with a start codon four or seven nucleotides downstream of the VP2 initiation codon. Green fluorescent protein or FLAG fusion constructs of SAT demonstrated that these ORFs were expressed. Although the SAT proteins of the different parvoviruses are not particularly conserved, they were all predicted to contain a membrane-spanning helix, and mutations in this hydrophobic stretch affected the localization of the SAT protein. SAT colocalized with calreticulin in the membranes of the endoplasmic reticulum and the nucleus. A knockout mutant (SAT(-)), with an unmodified VP sequence, showed a "slow-spreading" phenotype. These knockout mutants could be complemented with VP2(-) SAT(+) mutant. The SAT protein is a late nonstructural (NS) protein, in contrast to previously identified NS proteins, since it is expressed from the same mRNA as VP2.

  9. SHA-1, SAT-solving, and CNF

    CSIR Research Space (South Africa)

    Motara, YM

    2017-09-01

    Full Text Available . The per-round output in this stage is denoted by the symbol a, and it is therefore the last five 32-bit words, comprising the final 160 bits generated by the compression function, which will have particular values for a given 16-word input. The output may..., and this means that SAT-solvers are worse than brute force solutions as far as the preimage problem is concerned. This result is not surprising. However, the vastly different behaviours of the different SAT-solvers when faced with different encodings...

  10. Which pulmonary volume should be used in physiotherapy to obtain higher maximal inspiratory pressure in COPD patients?

    Science.gov (United States)

    Marinho, Patricia E M; Berenguer, Amanda; Barros, Andresa; Silva, Thayse N S; Galindo Filho, Valdecir C; De Andrade, Arméle Dornelas; Campos, Tânia F

    2005-01-01

    Patients with chronic obstructive pulmonary disease (COPD) present pulmonary hyperinflation as the main cause of mechanical disadvantages in respiratory muscles. Measurement of the force generated by those muscles is converted into pressure changes. The aim of the present study was to evaluate the maximal inspiratory pressure (MIP) from the residual volume (RV) and from the functional residual capacity (FRC), in patients with COPD, and to determine which pulmonary volume should be used in physiotherapy so as to obtain higher MIP results. An investigation of 18 male patients with stable COPD. Patients were examined using a manual vacuometer to measure the MIP of 20 daily manoeuvres. Ten measurements were taken from the RV and 10 from the FRC, taken alternately with an interval of 1 minute between each measurement, for five consecutive days. Increases in MIP were obtained from the RV measurements (mean +/- SE) from 59.7 (+/- 5.2) to 66.6 (+/- 5.3) cm H2O (F(4,64) = 3.34; p < 0.015) and from the FRC measurements, from 55.4 (+/- 4.9) to 64.4 (+/- 4,8) cm H2O (F(4,64) = 6.72; p < 0.001). Post hoc analysis showed an increase, over consecutive days, in both RV and FRC. For FRC, an increase was revealed on the second and third days, a fall was found on the fourth day and a new increase was found on the last day. MIP reached different levels, between RV and FRC, on the first (t = 2.888; p = 0.010) and fourth (t = 2.165; p = 0.045) days. In the present study, MIP reached higher levels at FRC during the five days of evaluation, and a learning effect occurred in the patients. Motor units from the respiratory muscles may have been recruited in order to perform the manoeuvres during the days of evaluation. The study suggests that there is good evidence for the use of the FRC as a parameter to find the major MIP value.

  11. SAT Participation and Performance for the Class of 2014. Memorandum

    Science.gov (United States)

    Sanderson, Geoffrey T.

    2014-01-01

    SAT participation and performance are milestones on the path to college and career readiness. This report provides the results for SAT participation and performance in Montgomery County (Maryland) Public Schools (MCPS) for the class of 2014. Analysis of postsecondary outcomes for MCPS graduates indicates that graduates who took the SAT were more…

  12. Higher-order accurate space-time schemes for computational astrophysics—Part I: finite volume methods

    Science.gov (United States)

    Balsara, Dinshaw S.

    2017-12-01

    As computational astrophysics comes under pressure to become a precision science, there is an increasing need to move to high accuracy schemes for computational astrophysics. The algorithmic needs of computational astrophysics are indeed very special. The methods need to be robust and preserve the positivity of density and pressure. Relativistic flows should remain sub-luminal. These requirements place additional pressures on a computational astrophysics code, which are usually not felt by a traditional fluid dynamics code. Hence the need for a specialized review. The focus here is on weighted essentially non-oscillatory (WENO) schemes, discontinuous Galerkin (DG) schemes and PNPM schemes. WENO schemes are higher order extensions of traditional second order finite volume schemes. At third order, they are most similar to piecewise parabolic method schemes, which are also included. DG schemes evolve all the moments of the solution, with the result that they are more accurate than WENO schemes. PNPM schemes occupy a compromise position between WENO and DG schemes. They evolve an Nth order spatial polynomial, while reconstructing higher order terms up to Mth order. As a result, the timestep can be larger. Time-dependent astrophysical codes need to be accurate in space and time with the result that the spatial and temporal accuracies must be matched. This is realized with the help of strong stability preserving Runge-Kutta schemes and ADER (Arbitrary DERivative in space and time) schemes, both of which are also described. The emphasis of this review is on computer-implementable ideas, not necessarily on the underlying theory.

  13. Investigating SATS-36 for a Matriculation Sample

    Science.gov (United States)

    Krishnan, Saras; Idris, Noraini

    2015-01-01

    Students' attitudes towards statistics have been more often negative due to many factors such as initial perception of the subject, low ability in mathematics and lack of motivation to study statistics. Studies involving SATS-36 included investigation of the different factors in relation to students' attitude towards statistics. Other studies have…

  14. CryoSat product quality and evolutions

    Science.gov (United States)

    Bouffard, Jérome; Parrinello, Tommaso; Féménias, Pierre

    2017-04-01

    The main CryoSat mission objectives are to measure the regional and basin-scale changes in the thickness of the sea-ice and, in the elevation of the ice sheets and mountain glaciers. Beside its ice-monitoring objective, CryoSat also provides valuable observations for the oceanographic community. The CryoSat data are processed by ESA both over the ocean and ice surfaces with two independent processors. These data need to be routinely Quality-Controlled and thoroughly Validated (QCV). Based on the QCV outcomes from ESA multi-national partners and the feedback from the scientific community, the data products continuously evolve in order to accommodate a wide range of users over the Sea ice, the Land Ice and the Ocean domains. The main objectives of this paper are to give an overview of main CryoSat QCV results and product improvements; as well as to present the processing algorithm upgrades being implemented for future ice and ocean Baselines.

  15. SAT-WIND project. Final report

    DEFF Research Database (Denmark)

    Hasager, Charlotte Bay; Astrup, Poul; Nielsen, Niels Morten

    The SAT-WIND project 'Winds from satellites for offshore and coastal wind energy mapping and wind-indexing' was a research project funded by STVF/DSF in the years 2003 to 2006 (Sagsnr. 2058-03-0006). The goal of the project was to verify the applicability of satellite wind maps derived from passive...

  16. Enhancing SAT Based Planning with Landmark Knowledge

    NARCIS (Netherlands)

    Elffers, J.; Konijnenberg, D.; Walraven, E.M.P.; Spaan, M.T.J.

    2013-01-01

    Several approaches exist to solve Artificial Intelligence planning problems, but little attention has been given to the combination of using landmark knowledge and satisfiability (SAT). Landmark knowledge has been exploited successfully in the heuristics of classical planning. Recently it was also

  17. SAT Scores, Journalism and Public Policy.

    Science.gov (United States)

    Meyer, Philip

    1993-01-01

    The two symposium articles extend "USA Today" SAT state ranking efforts by examining which states have the highest achievers, add the most value to enrolled students, and use resources most effectively. Dynarski and Gleason show that this test measures educational achievement more than innate ability. Graham and Husted adjust rankings…

  18. The liver and kidney expression of sulfate anion transporter sat-1 in rats exhibits male-dominant gender differences.

    Science.gov (United States)

    Brzica, Hrvoje; Breljak, Davorka; Krick, Wolfgang; Lovrić, Mila; Burckhardt, Gerhard; Burckhardt, Birgitta C; Sabolić, Ivan

    2009-04-01

    The sulfate anion transporter (sat-1, Slc26a1) has been cloned from rat liver, functionally characterized, and localized to the sinusoidal membrane in hepatocytes and basolateral membrane (BLM) in proximal tubules (PT). Here, we confirm previously described localization of sat-1 protein in rat liver and kidneys and report on gender differences (GD) in its expression by immunochemical, transport, and excretion studies in rats. The approximately 85-kDa sat-1 protein was localized to the sinusoidal membrane in hepatocytes and BLM in renal cortical PT, with the male-dominant expression. However, the real-time reverse-transcription polymerase chain reaction data indicated no GD at the level of sat-1 mRNA. In agreement with the protein data, isolated membranes from both organs exhibited the male-dominant exchange of radiolabeled sulfate for oxalate, whereas higher oxalate in plasma and 24-h urine indicated higher oxalate production and excretion in male rats. Furthermore, the expression of liver, but not renal, sat-1 protein was: unaffected by castration, upregulated by ovariectomy, and downregulated by estrogen or progesterone treatment in males. Therefore, GD (males > females) in the expression of sat-1 protein in rat liver (and, possibly, kidneys) are caused by the female sex-hormone-driven inhibition at the posttranscriptional level. The male-dominant abundance of sat-1 protein in liver may conform to elevated uptake of sulfate and extrusion of oxalate, causing higher plasma oxalate in males. Oxalate is then excreted by the kidneys via the basolateral sat-1 (males > females) and the apical CFEX (Slc26a6; GD unknown) in PT and eliminated in the urine (males > females), where it may contribute to the male-prevailing development of oxalate urolithiasis.

  19. The SAT Protein of Porcine Parvovirus Accelerates Viral Spreading through Induction of Irreversible Endoplasmic Reticulum Stress.

    Science.gov (United States)

    Mészáros, István; Tóth, Renáta; Olasz, Ferenc; Tijssen, Peter; Zádori, Zoltán

    2017-08-15

    The SAT protein (SATp) of porcine parvovirus (PPV) accumulates in the endoplasmic reticulum (ER), and SAT deletion induces the slow-spreading phenotype. The in vitro comparison of the wild-type Kresse strain and its SAT knockout (SAT-) mutant revealed that prolonged cell integrity and late viral release are responsible for the slower spreading of the SAT- virus. During PPV infection, regardless of the presence or absence of SATp, the expression of downstream ER stress response proteins (Xbp1 and CHOP) was induced. However, in the absence of SATp, significant differences in the quantity and the localization of CHOP were detected, suggesting a role of SATp in the induction of irreversible ER stress in infected cells. The involvement of the induction of irreversible ER stress in porcine testis (PT) cell necrosis and viral egress was confirmed by treatment of infected cells by ER stress-inducing chemicals (MG132, dithiothreitol, and thapsigargin), which accelerated the egress and spreading of both the wild-type and the SAT- viruses. UV stress induction had no beneficial effect on PPV infection, underscoring the specificity of ER stress pathways in the process. However, induction of CHOP and its nuclear translocation cannot alone be responsible for the biological effect of SAT, since nuclear CHOP could not complement the lack of SAT in a coexpression experiment.IMPORTANCE SATp is encoded by an alternative open reading frame of the PPV genome. Earlier we showed that SATp of the attenuated PPV NADL-2 strain accumulates in the ER and accelerates virus release and spreading. Our present work revealed that slow spreading is a general feature of SAT- PPVs and is the consequence of prolonged cell integrity. PPV infection induced ER stress in infected cells regardless of the presence of SATp, as demonstrated by the morphological changes of the ER and expression of the stress response proteins Xbp1 and CHOP. However, the presence of SATp made the ER stress more severe and

  20. Higher convection volume exchange with online hemodiafiltration is associated with survival advantage for dialysis patients: the effect of adjustment for body size.

    Science.gov (United States)

    Davenport, Andrew; Peters, Sanne A E; Bots, Michiel L; Canaud, Bernard; Grooteman, Muriel P C; Asci, Gulay; Locatelli, Francesco; Maduell, Francisco; Morena, Marion; Nubé, Menso J; Ok, Ercan; Torres, Ferran; Woodward, Mark; Blankestijn, Peter J

    2016-01-01

    Mortality remains high for hemodialysis patients. Online hemodiafiltration (OL-HDF) removes more middle-sized uremic toxins but outcomes of individual trials comparing OL-HDF with hemodialysis have been discrepant. Secondary analyses reported higher convective volumes, easier to achieve in larger patients, and improved survival. Here we tested different methods to standardize OL-HDF convection volume on all-cause and cardiovascular mortality compared with hemodialysis. Pooled individual patient analysis of four prospective trials compared thirds of delivered convection volume with hemodialysis. Convection volumes were either not standardized or standardized to weight, body mass index, body surface area, and total body water. Data were analyzed by multivariable Cox proportional hazards modeling from 2793 patients. All-cause mortality was reduced when the convective dose was unstandardized or standardized to body surface area and total body water; hazard ratio (95% confidence intervals) of 0.65 (0.51-0.82), 0.74 (0.58-0.93), and 0.71 (0.56-0.93) for those receiving higher convective doses. Standardization by body weight or body mass index gave no significant survival advantage. Higher convection volumes were generally associated with greater survival benefit with OL-HDF, but results varied across different ways of standardization for body size. Thus, further studies should take body size into account when evaluating the impact of delivered convection volume on mortality end points. Copyright © 2015 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.

  1. Predicting College Performance of American Indians: A Large-Sample Examination of the SAT

    Science.gov (United States)

    Shu, Siwen; Kuncel, Nathan R.; Sackett, Paul R.

    2017-01-01

    Extensive research has examined the validity and fairness of standardized tests in academic admissions. However, due to their underrepresentation in higher education, American Indians have gained much less attention in this research. In the present study, we examined for American Indian students (1) group differences on SAT scores, (2) the…

  2. ACT/SAT Test Preparation and Coaching Programs. What Works Clearinghouse Intervention Report

    Science.gov (United States)

    What Works Clearinghouse, 2016

    2016-01-01

    Most colleges and universities in the United States require students to take the SAT or ACT as part of the college application process. These tests are high stakes in at least three ways. First, most universities factor scores on these tests into admissions decisions. Second, higher scores can increase a student's chances of being admitted to…

  3. System Assessment of a High Power 3-U CubeSat

    Science.gov (United States)

    Shaw, Katie

    2016-01-01

    The Advanced eLectrical Bus (ALBus) CubeSat project is a technology demonstration mission of a 3-UCubeSat with an advanced, digitally controlled electrical power system capability and novel use of Shape Memory Alloy (SMA) technology for reliable deployable solar array mechanisms. The objective of the project is to, through an on orbit demonstration, advance the state of power management and distribution (PMAD) capabilities to enable future missions requiring higher power, flexible and reliable power systems. The goals of the mission include demonstration of: 100 Watt distribution to a target electrical load, efficient battery charging in the orbital environment, flexible power system distribution interfaces, adaptation of power system control on orbit, and reliable deployment of solar arrays and antennas utilizing re-settable SMA mechanisms. The power distribution function of the ALBus PMAD system is unique in the total power to target load capability of 100 W, the flexibility to support centralized or point-to-load regulation and ability to respond to fast transient power requirements. Power will be distributed from batteries at 14.8 V, 6.5 A to provide 100 W of power directly to a load. The deployable solar arrays utilize NASA Glenn Research Center superelastic and activated Nitinol(Nickel-Titanium alloy) Shape Memory Alloy (SMA) technology for hinges and a retention and release mechanism. The deployable solar array hinge design features utilization of the SMA material properties for dual purpose. The hinge uses the shape memory properties of the SMA to provide the spring force to deploy the arrays. The electrical conductivity properties of the SMA also enables the design to provide clean conduits for power transfer from the deployable arrays to the power management system. This eliminates the need for electrical harnesses between the arrays and the PMAD system in the ALBus system design. The uniqueness of the SMA retention and release mechanism design is the

  4. Interplanetary CubeSats system for space weather evaluations and technology demonstration

    Science.gov (United States)

    Viscio, Maria Antonietta; Viola, Nicole; Corpino, Sabrina; Stesina, Fabrizio; Fineschi, Silvano; Fumenti, Federico; Circi, Christian

    2014-11-01

    The paper deals with the mission analysis and conceptual design of an interplanetary 6U CubeSats system to be implemented in the L1 Earth-Sun Lagrangian Point mission for solar observation and in-situ space weather measurements. Interplanetary CubeSats could be an interesting alternative to big missions, to fulfill both scientific and technological tasks in deep space, as proved by the growing interest in this kind of application in the scientific community and most of all at NASA. Such systems allow less costly missions, due to their reduced sizes and volumes, and consequently less demanding launches requirements. The CubeSats mission presented in this paper is aimed at supporting measurements of space weather. The mission envisages the deployment of a 6U CubeSats system in the L1 Earth-Sun Lagrangian Point, where solar observations for in situ measurements of space weather to provide additional warning time to Earth can be carried out. The proposed mission is also intended as a technology validation mission, giving the chance to test advanced technologies, such as telecommunications and solar sails, envisaged as propulsion system. Furthermore, traveling outside the Van Allen belts, the 6U CubeSats system gives the opportunity to further investigate the space radiation environment: radiation dosimeters and advanced materials are envisaged to be implemented, in order to test their response to the harsh space environment, even in view of future implementation on other spacecrafts (e.g. manned spacecrafts). The main issue related to CubeSats is how to fit big science within a small package - namely power, mass, volume, and data limitations. One of the objectives of the work is therefore to identify and size the required subsystems and equipment, needed to accomplish specific mission objectives, and to investigate the most suitable configuration, in order to be compatible with the typical CubeSats (multi units) standards. The work has been developed as collaboration

  5. The Uses of Institutional Culture: Strengthening Identification and Building Brand Equity in Higher Education. ASHE Higher Education Report, Volume 31, Number 2

    Science.gov (United States)

    Toma, J. Douglas, Ed.; Dubrow, Greg, Ed.; Hartley, Matthew, Ed.

    2005-01-01

    Institutional culture matters in higher education, and universities and colleges commonly express the need to strengthen their culture. A strong culture is perceived, correctly so, to engender a needed sense of connectedness between and among the varied constituents associated with a campus. Linking organizational culture and social cohesion is…

  6. Evaluation of multi-mode CryoSat-2 altimetry data over the Po River against in situ data and a hydrodynamic model

    Science.gov (United States)

    Schneider, Raphael; Tarpanelli, Angelica; Nielsen, Karina; Madsen, Henrik; Bauer-Gottwein, Peter

    2018-02-01

    Coverage of in situ observations to monitor surface waters is insufficient on the global scale, and decreasing across the globe. Satellite altimetry has become an increasingly important monitoring technology for continental surface waters. The ESA CryoSat-2 altimetry mission, launched in 2010, has two novel features. (i) The radar altimeter instrument on board of CryoSat-2 is operated in three modes; two of them reduce the altimeter footprint by using Delay-Doppler processing. (ii) CryoSat-2 is placed on a distinct orbit with a repeat cycle of 369 days, leading to a drifting ground track pattern. The drifting ground track pattern challenges many common methods of processing satellite altimetry data over rivers. This study evaluates the observation error of CryoSat-2 water level observations over the Po River, Italy, against in situ observations. The average RMSE between CryoSat-2 and in situ observations was found to be 0.38 meters. CryoSat-2 was also shown to be useful for channel roughness calibration in a hydrodynamic model of the Po River. The small across-track distance of CryoSat-2 means that observations are distributed almost continuously along the river. This allowed resolving channel roughness with higher spatial resolution than possible with in situ or virtual station altimetry data. Despite the Po River being extensively monitored, CryoSat-2 still provides added value thanks to its unique spatio-temporal sampling pattern.

  7. Substance abuse risk in emerging adults associated with smaller frontal gray matter volumes and higher externalizing behaviors.

    Science.gov (United States)

    Weiland, Barbara J; Korycinski, Steven T; Soules, Mary; Zubieta, Jon-Kar; Zucker, Robert A; Heitzeg, Mary M

    2014-04-01

    During emerging adulthood, alcohol and substance use peak. Previous research has suggested that prefrontal and subcortical brain volumes may relate to risk for development of substance abuse. Epidemiological studies indicate that early initiation of alcohol or drug use significantly increases the likelihood of later substance use disorder diagnoses. We hypothesized that frontal regions would be smaller in young adults with early substance use and related problems (early-risk, ER), compared with a control group without early use/problems (C). We further hypothesized that these volumes would be associated with more externalizing behaviors, an additional robust predictor of substance abuse. One hundred and six subjects, ages 18-23, underwent high-resolution anatomical magnetic resonance image scanning. Individuals were categorized as C (n=64) or ER (n=42) using a composite-score of early alcohol/drug use and problems based on prospectively collected assessments; externalizing behaviors were also previously assessed during adolescence. Neuroanatomical volumes were compared between groups and correlated with behavioral measures. ER subjects exhibited more externalizing behaviors than their control counterparts. Total left frontal cortex and left superior frontal cortex volumes were significantly smaller in the ER group, controlling for family history of alcoholism and current substance use. Total gray matter volumes were negatively associated with substance risk score. Further, externalizing behavior score was negatively correlated with both left superior cortical and left total cortical volumes. These findings suggest that smaller frontal cortical volumes, specifically the left superior frontal cortex, represent an underlying risk factor for substance abuse in emerging adults. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  8. Back to Basics: Solving Games with SAT

    Directory of Open Access Journals (Sweden)

    QUER, S.

    2016-08-01

    Full Text Available Games became popular, within the formal verification community, after their application to automatic synthesis of circuits from specifications, and they have been receiving more and more attention since then. This paper focuses on coding the "Sokoban" puzzle, i.e., a very complex single-player strategy game. We show how its solution can be encoded and represented as a Bounded Model Checking problem, and then solved with a SAT solver. After that, to cope with very complex instances of the game, we propose two different ad-hoc divide-and-conquer strategies. Those strategies, somehow similar to state-of-the-art abstraction-and-refinement schemes, are able to decompose deep Bounded Model Checking instances into easier subtasks, trading-off between efficiency and completeness. We analyze a vast set of difficult hard-to-solve benchmark games, trying to push forward the applicability of state-of-the-art SAT solvers in the field. Those results show that games may provide one of the next frontier for the SAT community.

  9. DubaiSat-1 mission overview

    Science.gov (United States)

    Al Rais, Adnan

    2011-11-01

    The Emirates Institution for Advanced Science and technology (EIAST) was founded in 2006 to inspire scientific innovation and foster technological advancement in the United Arab Emirates through its various initiatives and programs. The Space Programme is the first initiative introduced by EIAST aiming at making the UAE an internationally recognized hub for advanced space systems and supporting the creation of a knowledge-based economy by leveraging the advances in the satellite systems. EIAST leading project and starting point in the space programme is DubaiSat-1 satellite mission. The satellite was designed and developed by Satrec Initiative - a pioneer satellite manufacturing company in South Korea, with a strong participation from EIAST engineers. DubaiSat-1 is a catalyst project and part of an in-depth know how and technology transfer program to convey advanced satellites technology to the UAE. The launch of the satellite was on July 29th 2009 onboard Dnepr rocket from Baikonur launch site in Kazakhstan. DubaiSat-1 observes the Earth at a Low Earth Orbit (LEO) with an altitude of 680 Km and generates high resolution optical images at 2.5m panchromatic (Pan) and 5m multispectral (MS) bands at red, green, blue and Near-infrared. The images provide variety of users and decision makers in the UAE with a valuable tool for a wide range of applications including infrastructure development, urban planning as well as environment monitoring and protection.

  10. SmallSat Innovations for Planetary Science

    Science.gov (United States)

    Weinberg, Jonathan; Petroy, Shelley; Roark, Shane; Schindhelm, Eric

    2017-10-01

    As NASA continues to look for ways to fly smaller planetary missions such as SIMPLEX, MoO, and Venus Bridge, it is important that spacecraft and instrument capabilities keep pace to allow these missions to move forward. As spacecraft become smaller, it is necessary to balance size with capability, reliability and payload capacity. Ball Aerospace offers extensive SmallSat capabilities matured over the past decade, utilizing our broad experience developing mission architecture, assembling spacecraft and instruments, and testing advanced enabling technologies. Ball SmallSats inherit their software capabilities from the flight proven Ball Configurable Platform (BCP) line of spacecraft, and may be tailored to meet the unique requirements of Planetary Science missions. We present here recent efforts in pioneering both instrument miniaturization and SmallSat/sensorcraft development through mission design and implementation. Ball has flown several missions with small, but capable spacecraft. We also have demonstrated a variety of enhanced spacecraft/instrument capabilities in the laboratory and in flight to advance autonomy in spaceflight hardware that can enable some small planetary missions.

  11. Touchscreen Sustained Attention Task (SAT) for Rats.

    Science.gov (United States)

    Bangasser, Debra A; Wicks, Brittany; Waxler, David E; Eck, Samantha R

    2017-09-15

    Sustained attention is the ability to monitor intermittent and unpredictable events over a prolonged period of time. This attentional process subserves other aspects of cognition and is disrupted in certain neurodevelopmental, neuropsychiatric, and neurodegenerative disorders. Thus, it is clinically important to identify mechanisms that impair and improve sustained attention. Such mechanisms are often first discovered using rodent models. Therefore, several behavior procedures for testing aspects of sustained attention have been developed for rodents. One, first described by McGaughy and Sarter (1995), called the sustained attention task (SAT), trains rats to distinguish between signal (i.e., brief light presentation) and non-signal trials. The signals are short and thus require careful attention to be perceived. Attentional demands can be increased further by introducing a distractor (e.g., flashing houselight). We have modified this task for touchscreen operant chambers, which are configured with a touchscreen on one wall that can present stimuli and record responses. Here we detail our protocol for SAT in touchscreen chambers. Additionally, we present standard measures of performance in male and female Sprague-Dawley rats. Comparable performance on this task in both sexes highlights its use for attention studies, especially as more researchers are including female rodents in their experimental design. Moreover, the easy implementation of SAT for the increasingly popular touchscreen chambers increases its utility.

  12. Big Software for SmallSats: Adapting cFS to CubeSat Missions

    Science.gov (United States)

    Cudmore, Alan P.; Crum, Gary Alex; Sheikh, Salman; Marshall, James

    2015-01-01

    Expanding capabilities and mission objectives for SmallSats and CubeSats is driving the need for reliable, reusable, and robust flight software. While missions are becoming more complicated and the scientific goals more ambitious, the level of acceptable risk has decreased. Design challenges are further compounded by budget and schedule constraints that have not kept pace. NASA's Core Flight Software System (cFS) is an open source solution which enables teams to build flagship satellite level flight software within a CubeSat schedule and budget. NASA originally developed cFS to reduce mission and schedule risk for flagship satellite missions by increasing code reuse and reliability. The Lunar Reconnaissance Orbiter, which launched in 2009, was the first of a growing list of Class B rated missions to use cFS.

  13. Advances in Ka-Band Communication System for CubeSats and SmallSats

    Science.gov (United States)

    Kegege, Obadiah; Wong, Yen F.; Altunc, Serhat

    2016-01-01

    A study was performed that evaluated the feasibility of Ka-band communication system to provide CubeSat/SmallSat high rate science data downlink with ground antennas ranging from the small portable 1.2m/2.4m to apertures 5.4M, 7.3M, 11M, and 18M, for Low Earth Orbit (LEO) to Lunar CubeSat missions. This study included link analysis to determine the data rate requirement, based on the current TRL of Ka-band flight hardware and ground support infrastructure. Recent advances in Ka-band transceivers and antennas, options of portable ground stations, and various coverage distances were included in the analysis. The link/coverage analysis results show that Cubesat/Smallsat missions communication requirements including frequencies and data rates can be met by utilizing Near Earth Network (NEN) Ka-band support with 2 W and high gain (>6 dBi) antennas.

  14. From Higher Education to Employment. Volume IV: Portugal, United Kingdom, Sweden, Switzerland = De l'enseignement superieur a l'emploi. Volume IV: Portugal, Royaume-Uni, Suede, Suisse.

    Science.gov (United States)

    Organisation for Economic Cooperation and Development, Paris (France).

    This volume reports on the flow of graduates from higher education into working life in Portugal, the United Kingdom, Sweden and Switzerland. Chapters for each nation were contributed by national experts in that field. The first section of the report, on Portugal, contains two papers. The first, written in English, discusses recent changes in the…

  15. From Higher Education To Employment. Volume II: Canada, Denmark, Spain, United States = De l'enseignement superieur a l'emploi. Volume II: Canada, Danemark, Expagne, Etats-Unis.

    Science.gov (United States)

    Organisation for Economic Cooperation and Development, Paris (France).

    This volume presents reports on the flows of graduates from higher education and on their entry into working life in Canada, Denmark, Spain and the United States. Each paper is written according to detailed guidelines designed to assemble information from many sources, to reflect the state of the art, and to illustrate a variety of approaches,…

  16. A higher volume of fibrotic tissue on virtual histology prior to coronary stent implantation predisposes to more pronounced neointima proliferation.

    Science.gov (United States)

    Haine, Steven; Wouters, Kristien; Miljoen, Hielko; Vandendriessche, Tom; Claeys, Marc; Bosmans, Johan; Vrints, Christiaan

    2017-08-11

    Since neointima smooth muscle cells (SMC) mainly originate from the vessel wall, we investigated whether atherosclerotic plaque composition influences subsequent in-stent neointima proliferation and restenosis. We performed intravascular ultrasound (IVUS) with virtual histology in 98 patients prior to elective bare-metal stent (BMS) implantation in de novo coronary artery lesions. Virtual histology variables pre-percutaneous coronary intervention (PCI) were related to in-stent neointima proliferation six months after implantation assessed as late luminal loss of 0.88 mm (interquartile range (IQR) 0.37-1.23 mm) on angiography and as maximal percentage area stenosis of 42% (IQR 33-59%) and percentage volume intima hyperplasia of 27% (IQR 20-36%) on IVUS. A ridge-trace based multiple linear regression model was constructed to account for multicollinearity of the virtual histology variables and was corrected for implanted stent length (18 mm, IQR 15-23 mm), stent diameter (3.0 mm, IQR 2.75-3.5 mm) and lesion volume (146 mm³, IQR 80-201 mm³) prior to PCI. Fibrous tissue volume prior to PCI (49 mm³, IQR 30-77 mm³) was significantly and independently related to late luminal loss (p = .038), maximal percentage area stenosis (p = .041) and percentage volume intima hyperplasia (p = .004). Neither absolute nor relative amounts of fibrofatty, calcified or necrotic core tissue appeared related to any of the restenosis parameters. Subgroup analysis after exclusion of acute coronary syndrome (ACS) patients yielded similar results. Lesions with more voluminous fibrotic tissue pre-PCI show more pronounced in-stent neointima proliferation, even after correction for lesion plaque volume.

  17. Finite-Size Scaling in Random K-SAT Problems

    Science.gov (United States)

    Ha, Meesoon; Lee, Sang Hoon; Jeon, Chanil; Jeong, Hawoong

    2010-03-01

    We propose a comprehensive view of threshold behaviors in random K-satisfiability (K-SAT) problems, in the context of the finite-size scaling (FSS) concept of nonequilibrium absorbing phase transitions using the average SAT (ASAT) algorithm. In particular, we focus on the value of the FSS exponent to characterize the SAT/UNSAT phase transition, which is still debatable. We also discuss the role of the noise (temperature-like) parameter in stochastic local heuristic search algorithms.

  18. Validity of the SAT for Predicting First-Year Grades: 2008 SAT Validity Sample. Statistical Report No. 2011-5

    Science.gov (United States)

    Patterson, Brian F.; Mattern, Krista D.

    2011-01-01

    The findings for the 2008 sample are largely consistent with the previous reports. SAT scores were found to be correlated with FYGPA (r = 0.54), with a magnitude similar to HSGPA (r = 0.56). The best set of predictors of FYGPA remains SAT scores and HSGPA (r = 0.63), as the addition of the SAT sections to the correlation of HSGPA alone with FYGPA…

  19. The NASA CloudSat/GPM Light Precipitation Validation Experiment (LPVEx)

    Science.gov (United States)

    Petersen, Walter A.; L'Ecuyer, Tristan; Moisseev, Dmitri

    2011-01-01

    Ground-based measurements of cool-season precipitation at mid and high latitudes (e.g., above 45 deg N/S) suggest that a significant fraction of the total precipitation volume falls in the form of light rain, i.e., at rates less than or equal to a few mm/h. These cool-season light rainfall events often originate in situations of a low-altitude (e.g., lower than 2 km) melting level and pose a significant challenge to the fidelity of all satellite-based precipitation measurements, especially those relying on the use of multifrequency passive microwave (PMW) radiometers. As a result, significant disagreements exist between satellite estimates of rainfall accumulation poleward of 45 deg. Ongoing efforts to develop, improve, and ultimately evaluate physically-based algorithms designed to detect and accurately quantify high latitude rainfall, however, suffer from a general lack of detailed, observationally-based ground validation datasets. These datasets serve as a physically consistent framework from which to test and refine algorithm assumptions, and as a means to build the library of algorithm retrieval databases in higher latitude cold-season light precipitation regimes. These databases are especially relevant to NASA's CloudSat and Global Precipitation Measurement (GPM) ground validation programs that are collecting high-latitude precipitation measurements in meteorological systems associated with frequent coolseason light precipitation events. In an effort to improve the inventory of cool-season high-latitude light precipitation databases and advance the physical process assumptions made in satellite-based precipitation retrieval algorithm development, the CloudSat and GPM mission ground validation programs collaborated with the Finnish Meteorological Institute (FMI), the University of Helsinki (UH), and Environment Canada (EC) to conduct the Light Precipitation Validation Experiment (LPVEx). The LPVEx field campaign was designed to make detailed measurements of

  20. OpenSatKit Enables Quick Startup for CubeSat Missions

    Science.gov (United States)

    McComas, David; Melton, Ryan

    2017-01-01

    The software required to develop, integrate, and operate a spacecraft is substantial regardless of whether its a large or small satellite. Even getting started can be a monumental task. To solve this problem, NASAs Core Flight System (cFS), NASA's 42 spacecraft dynamics simulator, and Ball Aerospaces COSMOS ground system have been integrated together into a kit called OpenSatKit that provides a complete and open source software solution for starting a new satellite mission. Users can have a working system with flight software, dynamics simulation, and a ground command and control system up and running within hours.Every satellite mission requires three primary categories of software to function. The first is Flight Software (FSW) which provides the onboard control of the satellites and its payload(s). NASA's cFS provides a great platform for developing this software. Second, while developing a satellite on earth, it is necessary to simulate the satellites orbit, attitude, and actuators, to ensure that the systems that control these aspects will work correctly in the real environment. NASAs 42 simulator provides these functionalities. Finally, the ground has to be able to communicate with the satellite, monitor its performance and health, and display its data. Additionally, test scripts have to be written to verify the system on the ground. Ball Aerospace's COSMOS command and control system provides this functionality. Once the OpenSatKit is up and running, the next step is to customize the platform and get it running on the end target. Starting from a fully working system makes porting the cFS from Linux to a users platform much easier. An example Raspberry Pi target is included in the kit so users can gain experience working with a low cost hardware target. All users can benefit from OpenSatKit but the greatest impact and benefits will be to SmallSat missions with constrained budgets and small software teams. This paper describes OpenSatKits system design, the

  1. SAT-Lab: Lenguaje de analisis estructural

    OpenAIRE

    Inaudi, José; Llera, Juan

    2003-01-01

    Convencidos del valor de la computación como herramienta complementaria en la etapa de formación y el de la programación como componenente imprescindible en la formación de ingenieros, se ha desarrollado una herramienta de análisis estructural con la visión de un lenguaje abierto más que de una herramienta computacional de producción convencional. SAT-Lab es un conjunto de funciones o lenguaje para el análisis estructural desarrollado en el ambiente de programación Matlab®. Es una herramienta...

  2. Resolución de los problemas MaxSAT y MinSAT mediante programación lineal entera

    OpenAIRE

    Belenguer Seuma, Andreu

    2012-01-01

    Presentación de una traducción de los problemas MaxSAT y MinSAT a un problema de programación lineal entera e implementación de un resolutor MaxSAT y MinSAT usando Python y el software de programación lineal entera CPLEX. Evaluación de los resultados comparándolos con los de la MaxSAT Evaluation 2010.

  3. Second Moment Method on k-SAT: a General Framework

    CERN Document Server

    Hugel, Thomas

    2010-01-01

    We give a general framework implementing the Second Moment Method on k-SAT and discuss the conditions making the Second Moment Method work in this framework. As applications, we make the Second Moment Method work on boolean solutions and implicants. We extend this to the distributional model of k-SAT.

  4. Comparison of CloudSat and TRMM radar reflectivities

    Indian Academy of Sciences (India)

    Keywords. CloudSat CPR; TRMM PR; CFADs; radar reflectivity. Abstract. Comparison of reflectivity data of radars onboard CloudSat and TRMM is performed using coincident overpasses. The contoured frequency by altitude diagrams (CFADs) are constructed for two cases: (a) only include collocated vertical profiles that ...

  5. Comparing State SAT Scores Using a Mixture Modeling Approach

    Science.gov (United States)

    Kim, YoungKoung Rachel

    2009-01-01

    Presented at the national conference for AERA (American Educational Research Association) in April 2009. The large variability of SAT taker population across states makes state-by-state comparisons of the SAT scores challenging. Using a mixture modeling approach, therefore, the current study presents a method of identifying subpopulations in terms…

  6. Foreign Language Learning and SAT Verbal Scores Revisited

    Science.gov (United States)

    Cooper, Thomas C.; Yanosky, Daniel J., II; Wisenbaker, Joseph M.; Jahner, David; Webb, Elizabeth; Wilbur, Marcia L.

    2008-01-01

    The purpose of the study was to investigate the relationship between foreign language learning and verbal ability in English as measured by the verbal section of the Scholastic Aptitude Test (SAT) Reasoning Test. Comparing foreign language students to nonforeign language students in this study, the effect of taking a foreign language on SAT verbal…

  7. SAT and ACT Predict College GPA after Removing "g"

    Science.gov (United States)

    Coyle, Thomas R.; Pillow, David R.

    2008-01-01

    This research examined whether the SAT and ACT would predict college grade point average (GPA) after removing g from the tests. SAT and ACT scores and freshman GPAs were obtained from a university sample (N=161) and the 1997 National Longitudinal Study of Youth (N=8984). Structural equation modeling was used to examine relationships among g, GPA,…

  8. AstroSat: From Inception to Realization and Launch

    Indian Academy of Sciences (India)

    The origin of the idea of AstroSat multi wavelength satellite mission and how it evolved over the next 15 years from a concept to the successful development of instruments for giving concrete shape to this mission, is recounted in this article. AstroSat is the outcome of intense deliberations in the Indian astronomy community ...

  9. MarsCAT: Mars Array of ionospheric Research Satellites using the CubeSat Ambipolar Thruster

    Science.gov (United States)

    Bering, E. A., III; Pinsky, L.; Li, L.; Jackson, D. R.; Chen, J.; Reed, H.; Moldwin, M.; Kasper, J. C.; Sheehan, J. P.; Forbes, J.; Heine, T.; Case, A. W.; Stevens, M. L.; Sibeck, D. G.

    2015-12-01

    The MarsCAT (Mars Array of ionospheric Research Satellites using the CubeSat Ambipolar Thruster) Mission is a two 6U CubeSat mission to study the ionosphere of Mars proposed for the NASA SIMPLeX opportunity. The mission will investigate the plasma and magnetic structure of the Martian ionosphere, including transient plasma structures, magnetic field structure and dynamics, and energetic particle activity. The transit plan calls for a piggy back ride with Mars 2020 using a CAT burn for MOI, the first demonstration of CubeSat propulsion for interplanetary travel. MarsCAT will make correlated multipoint studies of the ionosphere and magnetic field of Mars. Specifically, the two spacecraft will make in situ observations of the plasma density, temperature, and convection in the ionosphere of Mars. They will also make total electron content measurements along the line of sight between the two spacecraft and simultaneous 3-axis local magnetic field measurements in two locations. Additionally, MarsCAT will demonstrate the performance of new CubeSat telemetry antennas designed at the University of Houston that are designed to be low profile, rugged, and with a higher gain than conventional monopole (whip) antennas. The two MarsCAT CubeSats will have five science instruments: a 3-axis DC magnetometer, adouble-Langmuir probe, a Faraday cup, a solid state energetic particle detector (Science Enhancement Option), and interspacecraft total electron content radio occulation experiment. The MarsCAT spacecraft will be solar powered and equipped with a CAT thruster that can provide up to 4.8 km/s of delta-V, which is sufficient to achieve Mars orbit using the Mars 2020 piggyback. They have an active attitude control system, using a sun sensor and flight-proven star tracker for determination, and momentum wheels for 3-axis attitude control.

  10. Shifting Tides in Global Higher Education: Agency, Autonomy, and Governance in the Global Network. Global Studies in Education, Volume 9

    Science.gov (United States)

    Witt, Mary Allison

    2011-01-01

    The increasing connection among higher education institutions worldwide is well documented. What is less understood is how this connectivity is enacted and manifested on specific levels of the global education network. This book details the planning process of a multi-institutional program in engineering between institutions in the US and…

  11. Assessment Update: Progress, Trends, and Practices in Higher Education. Volume 25, Issue 2, March-April 2013

    Science.gov (United States)

    Banta, Trudy W., Ed.

    2013-01-01

    This issue of "Assessment Update" presents the following articles: (1) "Just Right" Outcomes Assessment: A Fable for Higher Education (Catherine M. Wehlburg); (2) Editor's Notes: Helping Faculty Members Learn (Linda Suskie); (3) Focus on the Bottom-Line: Assessing Business Writing (Michael Cherry and George Klemic); (4)…

  12. Achieving Science with CubeSats: Thinking Inside the Box

    Science.gov (United States)

    Zurbuchen, Thomas H.; Lal, Bhavya

    2017-01-01

    We present the results of a study conducted by the National Academies of Sciences, Engineering, and Medicine. The study focused on the scientific potential and technological promise of CubeSats. We will first review the growth of the CubeSat platform from an education-focused technology toward a platform of importance for technology development, science, and commercial use, both in the United States and internationally. The use has especially exploded in recent years. For example, of the over 400 CubeSats launched since 2000, more than 80% of all science-focused ones have been launched just in the past four years. Similarly, more than 80% of peer-reviewed papers describing new science based on CubeSat data have been published in the past five years.We will then assess the technological and science promise of CubeSats across space science disciplines, and discuss a subset of priority science goals that can be achieved given the current state of CubeSat capabilities. Many of these goals address targeted science, often in coordination with other spacecraft, or by using sacrificial or high-risk orbits that lead to the demise of the satellite after critical data have been collected. Other goals relate to the use of CubeSats as constellations or swarms, deploying tens to hundreds of CubeSats that function as one distributed array of measurements.Finally, we will summarize our conclusions and recommendations from this study; especially those focused on nearterm investment that could improve the capabilities of CubeSats toward increased science and technological return and enable the science communities’ use of CubeSats.

  13. Simulation of the Deployment and Orbit Operations of the NPS-SCAT CubeSat

    Science.gov (United States)

    2008-04-01

    is a great opportunity to implement the engeneering fundamentals learned at the University of the Federal Armed Forces Hamburg and an excellent...panels used. The higher the number, the more efficient the panels. This 17 number is a percentage of how well the cell can convert solar to electrical ...the standardized mechanical and electrical connection between the CubeSats and the launch vehicle. Actually, CalPoly only offers a 3U P-POD, but

  14. Design of Attitude Control Systems for CubeSat-Class Nanosatellite

    Directory of Open Access Journals (Sweden)

    Junquan Li

    2013-01-01

    Full Text Available We present a satellite attitude control system design using low-cost hardware and software for a 1U CubeSat. The attitude control system architecture is a crucial subsystem for any satellite mission since precise pointing is often required to meet mission objectives. The accuracy and precision requirements are even more challenging for small satellites where limited volume, mass, and power are available for the attitude control system hardware. In this proposed embedded attitude control system design for a 1U CubeSat, pointing is obtained through a two-stage approach involving coarse and fine control modes. Fine control is achieved through the use of three reaction wheels or three magnetorquers and one reaction wheel along the pitch axis. Significant design work has been conducted to realize the proposed architecture. In this paper, we present an overview of the embedded attitude control system design; the verification results from numerical simulation studies to demonstrate the performance of a CubeSat-class nanosatellite; and a series of air-bearing verification tests on nanosatellite attitude control system hardware that compares the performance of the proposed nonlinear controller with a proportional-integral-derivative controller.

  15. New electro-optic laser scanners for small-sat to ground laser communication links

    Science.gov (United States)

    Davis, Scott R.; Johnson, Seth T.; Rommel, Scott D.; Anderson, Michael H.; Chen, Jimmy; Chao, Tien-Hsin

    2013-05-01

    In this paper we present new electro-optic beam steering technology and propose to combine it with optical telecommunication technology, thereby enabling low cost, compact, and rugged free space optical (FSO) communication modules for small-sat applications. Small satellite applications, particularly those characterized as "micro-sats" are often highly constrained by their ability to provide high bandwidth science data to the ground. This will often limit the relevance of even highly capable payloads due to the lack of data availability. FSO modules with unprecedented cost and size, weight, and power (SWaP) advantages will enable multi-access FSO networks to spread across previously inaccessible platforms. An example system would fit within a few cubic inch volume, require less than 1 watt of power and be able to provide ground station tracking (including orbital motion over wide angles and jitter correction) with a 50 to 100 Mbps downlink and no moving parts. This is possible, for the first time, because of emergent and unprecedented electro-optic (EO) laser scanners which will replace expensive, heavy, and power-consuming gimbal mechanisms. In this paper we will describe the design, construction, and performance of these new scanners. Specific examples to be discussed include an all electro-optic beamsteer with a 60 degree by 40 degree field of view. We will also present designs for a cube-sat to ground flight demonstration. This development would provide a significant enhancement in capabilities for future NASA and other Government and industry space projects.

  16. CubeSats for Astrophysics: The Current Perspective

    Science.gov (United States)

    Ardila, David R.; Shkolnik, Evgenya; Gorjian, Varoujan

    2017-01-01

    Cubesats are small satellites built to multiples of 1U (1000 cm3). The 2016 NRC Report “Achieving Science with CubeSats” indicates that between 2013 and 2018 NASA and NSF sponsored 104 CubeSats. Of those, only one is devoted to astrophysics: HaloSat (PI: P. Kaaret), a 6U CubeSat with an X-ray payload to study the hot galactic halo.Despite this paucity of missions, CubeSats have a lot of potential for astrophysics. To assess the science landscape that a CubeSat astrophysics mission may occupy, we consider the following parameters:1-Wavelength: CubeSats are not competitive in the visible, unless the application (e.g. high precision photometry) is difficult to do from the ground. Thermal IR science is limited by the lack of low-power miniaturized cryocoolers and by the large number of infrared astrophysical missions launched or planned. In the UV, advances in δ-doping processes result in larger sensitivity with smaller apertures. Commercial X-ray detectors also allow for competitive science.2-Survey vs. Pointed observations: All-sky surveys have been done at most wavelengths from X-rays to Far-IR and CubeSats will not be able to compete in sensitivity with them. CubeSat science should then center on specific objects or object classes. Due to poor attitude control, unresolved photometry is scientifically more promising that extended imaging.3-Single-epoch vs. time domain: CubeSat apertures cannot compete in sensitivity with big satellites when doing single-epoch observations. However, time-domain astrophysics is an area in which CubeSats can provide very valuable science return.Technologically, CubeSat astrophysics is limited by:1-Lack of large apertures: The largest aperture CubeSat launched is ~10 cm, although deployable apertures as large as 20 cm could be fitted to 6U buses.2-Poor attitude control: State-of-the-art systems have demonstrated jitter of ~10” on timescales of seconds. Jitter imposes limits on image quality and, coupled with detector errors

  17. Near Earth Network (NEN) CubeSat Communications

    Science.gov (United States)

    Schaire, Scott

    2017-01-01

    The NASA Near Earth Network (NEN) consists of globally distributed tracking stations, including NASA, commercial, and partner ground stations, that are strategically located to maximize the coverage provided to a variety of orbital and suborbital missions, including those in LEO (Low Earth Orbit), GEO (Geosynchronous Earth Orbit), HEO (Highly Elliptical Orbit), lunar and L1-L2 orbits. The NEN's future mission set includes and will continue to include CubeSat missions. The first NEN-supported CubeSat mission will be the Cubesat Proximity Operations Demonstration (CPOD) launching into LEO in 2017. The majority of the CubeSat missions destined to fly on EM-1, launching in late 2018, many in a lunar orbit, will communicate with ground-based stations via X-band and will utilize the NASA Jet Propulsion Laboratory (JPL)-developed IRIS (Satellite Communication for Air Traffic Management) radio. The NEN recognizes the important role CubeSats are beginning to play in carrying out NASAs mission and is therefore investigating the modifications needed to provide IRIS radio compatibility. With modification, the NEN could potentially expand support to the EM-1 (Exploration Mission-1) lunar CubeSats. The NEN could begin providing significant coverage to lunar CubeSat missions utilizing three to four of the NEN's mid-latitude sites. This coverage would supplement coverage provided by the JPL Deep Space Network (DSN). The NEN, with smaller apertures than DSN, provides the benefit of a larger beamwidth that could be beneficial in the event of uncertain ephemeris data. In order to realize these benefits the NEN would need to upgrade stations targeted based on coverage ability and current configuration ease of upgrade, to ensure compatibility with the IRIS radio. In addition, the NEN is working with CubeSat radio developers to ensure NEN compatibility with alternative CubeSat radios for Lunar and L1-L2 CubeSats. The NEN has provided NEN compatibility requirements to several radio

  18. Higher Adolescent Body Mass Index is Associated with Lower Regional Gray and White Matter Volumes and Lower Levels of Positive Emotionality

    Directory of Open Access Journals (Sweden)

    James T Kennedy

    2016-09-01

    Full Text Available Adolescent obesity is associated with an increased chance of developing serious health risks later in life. Identifying the neurobiological and personality factors related to increases in adiposity is important to understanding what drives maladaptive consummatory and exercise behaviors that result in obesity. Previous research has largely focused on adults with few findings published on interactions among adiposity, brain structure, and personality. In this study, Voxel Based Morphometry (VBM was used to identify associations between gray and white matter volumes and increasing adiposity, as measured by Body Mass Index percentile (BMI%, in 137 adolescents (age range: 9-20 years, Body Mass Index percentile range: 5.16-99.56. Variations in gray and white matter volume and BMI% were then linked to individual differences in personality measures from the Multidimensional Personality Questionnaire (MPQ. After controlling for age and other covariates, BMI% correlated negatively with gray matter volume in the bilateral caudate (right: partial r = -0.338, left: r -0.404, medial prefrontal cortex (partial r = -0.339, anterior cingulate (partial r = -0.312, bilateral frontal pole (right: partial r = -0.368, left: r= -0.316, and uncus (partial r = -0.475 as well as white matter volume bilaterally in the anterior limb of the internal capsule (right: partial r = -0.34, left: r = -0.386, extending to the left middle frontal subgyral white matter. Agentic Positive Emotionality (PEM-AG was correlated negatively with BMI% (partial r = -0.384. PEM-AG was correlated positively with gray matter volume in the right uncus (partial r = 0.329. These results suggest that higher levels of adiposity in adolescents are associated with lower trait levels in reward-related personality domains, as well as structural variations in brain regions associated with reward processing, control, and sensory integration.

  19. 2-Sat Sub-Clauses and the Hypernodal Structure of the 3-Sat Problem

    OpenAIRE

    Powell, D. B.

    2004-01-01

    Like simpler graphs, nested (hypernodal) graphs consist of two components: a set of nodes and a set of edges, where each edge connects a pair of nodes. In the hypernodal graph model, however, a node may contain other graphs, so that a node may be contained in a graph that it contains. The inherently recursive structure of the hypernodal graph model aptly characterizes both the structure and dynamic of the 3-sat problem, a broadly applicable, though intractable, computer science problem. In th...

  20. Current smoking is associated with lower seminal vesicles and ejaculate volume, despite higher testosterone levels, in male subjects of infertile couples.

    Science.gov (United States)

    Lotti, F; Corona, G; Vitale, P; Maseroli, E; Rossi, M; Fino, M G; Maggi, M

    2015-03-01

    What is the impact of smoking behaviour on seminal, hormonal and male genital tract ultrasound parameters in subjects seeking medical care for couple infertility? In males of infertile couples, current smokers (CS), when compared with non-smokers, show lower ejaculate and ultrasound-derived seminal vesicles (SV) volume, despite higher testosterone levels. Data on the effects of smoking on male fertility are conflicting. A correlation between smoking and reduced semen parameters has been reported, however, with a high heterogeneity among studies. An association between smoking behaviour and higher testosterone levels in men has been described in several, but not all, the previous studies. No study has systematically evaluated the impact of smoking on the male genital tract ultrasound characteristics. Retrospective cross-sectional analysis of a consecutive series of 426 subjects seeking medical care for couple infertility from January 2010 to July 2013. From the entire cohort, 394 men (age 36.0 ± 8.0 years) free of genetic abnormalities were selected. All subjects underwent a complete andrological and physical examination, biochemical and hormonal assessment, scrotal and transrectal colour-Doppler ultrasound and semen analysis (including seminal interleukin-8 levels, sIL-8) within the same day. Among the patients evaluated, 229 were never smokers (NS), 56 past smokers (PS) and 109 CS. When CS were compared with the rest of the sample (non-smokers, NS + PS), in a multivariate model (analysis of covariance, ANCOVA) adjusted for age, lifestyle (including alcohol, cannabis and physical activity), BMI and sex hormone-binding globulin, significantly higher androgen (total testosterone, P = 0.001; calculated free testosterone, P fertile men, and therefore true normative data of sonographic parameters cannot be inferred. Due to the cross-sectional nature of our study, neither a causality hypothesis nor mechanistic models can be drawn. Finally, this is a retrospective study

  1. 3D Printing the Complete CubeSat

    Science.gov (United States)

    Kief, Craig

    2015-01-01

    The 3D Printing the Complete CubeSat project is designed to advance the state-of-the-art in 3D printing for CubeSat applications. Printing in 3D has the potential to increase reliability, reduce design iteration time and provide greater design flexibility in the areas of radiation mitigation, communications, propulsion, and wiring, among others. This project is investigating the possibility of including propulsion systems into the design of printed CubeSat components. One such concept, an embedded micro pulsed plasma thruster (mPPT), could provide auxiliary reaction control propulsion for a spacecraft as a means to desaturate momentum wheels.

  2. Airborne campaigns for CryoSat prelaunch calibration and validation

    DEFF Research Database (Denmark)

    Skourup, Henriette; Hanson, Susanne; Hvidegaard, Sine Munk

    2011-01-01

    After the successful launch of CryoSat-2 in April 2010, the first direct validation campaign of the satellite is planned for spring 2011. DTU Space has been involved in ESA’s CryoSat Validation Experiment (CryoVEx) with airborne activities since 2003. To validate the prelaunch performance...... of the CryoSat radar altimeter (SIRAL), an airborne version of the SIRAL altimeter (ASIRAS) has been flown together with a laser scanner in 2006 and 2008. Of particular interest is to study the penetration depth of the radar altimeter over both land- and sea ice. This can be done by comparing the radar...

  3. Function analysis of a new type I PKS-SAT domain by SAT-EAT domain replacement.

    Science.gov (United States)

    Jiao, Y L; Wang, L H; Jiao, B H; Wang, S J; Fang, Y W; Liu, S

    2010-01-01

    The function of a new starter unit acyltransferase (SAT) domain SAT-EF080951 (GenBank accession number) encoded in a new type I polyketide synthase (PKS) gene cluster EF568935 (GenBank accession number) isolated for this study was analyzed by domain replacement with an extender unit AT (EAT) domain of avermectin PKS. It was shown that the SAT-EF080951 incorporated malonyl-CoA specifically in vivo, which contradicted the specificity that we had previously determined by substrate binding test in vitro. The result of this study indicates that type I PKS-SAT can alter its specificity in vivo and functions well in extender units and proved the feasibility of the SAT-EAT domain replacement in type I PKS. We propose that SAT-EAT replacement strategy could be a novel route for increasing the diversity of new polyketides combinatorially biosynthesized. The new type I PKS-SAT-EF080951 studied herein may be further employed for related studies on enzymology or combinatorial biosynthesis of polyketides.

  4. Ames Infusion Stories for NASA Annual Technology Report: Nano Entry System for CubeSat-Class Payloads

    Science.gov (United States)

    Smith, Brandon; Jan, Darrell Leslie; Venkatapathy, Etiraj

    2015-01-01

    The Nano Entry System for CubeSat-Class Payloads led to the development of the Nano-Adaptable Deployable Entry and Placement Technology ("Nano-ADEPT"). Nano-ADEPT is a mechanically deployed entry, descent, and landing (EDL) system that stows during launch and cruise (like an umbrella) and serves as both heat shield and primary structure during EDL. It is especially designed for small spacecraft where volume is a limiting constraint.

  5. A Compilation of Federal Education Laws. Volume III--Higher Education. As Amended through December 31, 1982. Prepared for the Use of the Committee on Education and Labor. House of Representatives, Ninety-Eighth Congress, First Session.

    Science.gov (United States)

    Congress of the U.S., Washington, DC. House Committee on Education and Labor.

    A compilation of federal legislation that pertains to higher education is presented. The sections of this volume cover the general higher education programs, Native American higher education, museums, arts and humanities, and the National Science Foundation. The text of the Higher Education Act of 1965 is presented, covering Titles I-XIII. The…

  6. CubeSat Capabilities for Space Science Missions Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The CubeSat Capabilities for Space Science Missions combines science and engineering talent at Goddard Space Flight Center and the Wallops Flight Facility to...

  7. CubeSat Form Factor Thermal Control Louvers Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Thermal control of small spacecraft, including CubeSats, is a challenge for the next era of NASA spaceflight. Science objectives and components will still require...

  8. Hvorfor lejere bliver sat ud af deres bolig

    DEFF Research Database (Denmark)

    Nielsen, Torben Heien; Christensen, Gunvor

    Antallet af lejere, der bliver sat ud af deres bolig, er steget fra 1499 i 2002 til 2589 i 2006. Lejere kan blive sat ud af deres bolig, hvis de ikke betaler deres husleje til tiden, eller hvis de ikke overholder husordenen det sted de bor. Denne rapport beskriver årsager til, at lejere bliver sat...... ud af deres boliger og baggrunden for stigningen i antallet af udsættelser. desuden beskriver rapporten konsekvenser af en udsættelse og kommer med en række anbefalinger til indsatsområder. Af afgørende betydning for, at lejere bliver sat ud af deres bolig, er lav indkomst, lavt rådighedsbeløb, stor...

  9. Preparation of Foot and Mouth Disease trivalent vaccine type A, O, SAT2 with determination of the Guinea pig protective dose 50 (GPPD50

    Directory of Open Access Journals (Sweden)

    Hind M. Daoud

    2013-09-01

    Full Text Available Aim: To determine the minimal effective dose of Foot and Mouth disease (FMD serotypes (A, O, SAT2 according toantigenic content (146S in order to produce a potent trivalent FMD vaccine.Materials and Methods: Monovalent ISA 206 vaccines were prepared with 3 final concentration of 146S (1.6, 2.2, 2.8μg/dose. The vaccine potency was evaluated by the determination of guinea pig protective dose 50 (GPPD for each 50concentration of 146S for each type of FMD monovalent vaccine where a fourfold dilution of the vaccines was constructedand each dilution was inoculated as 0.5 ml S/C in each of 5 guinea pigs.Results: The obtained results revealed that by using 1.6 μg of 146S for type O Pan Asia-2, AIran O5 and SAT/EGY/2012, theGPPD was 40.4, 19.75 and 31.6 respectively, while the use of 2.2 μg of 146S resulted in GPPD 78.6, 78.6 and 105.8 for the 50 50three types respectively, and by using 2.8 μg of 146S resulted in GPPD 161.7, 105.8 and 161.7 for the three subtypes (A, O, 50SAT2 respectively. So it is clear that the lowest 146S dilution inducing good protection (more than 72 GPPD was 2.2 μg for 50each serotype of used FMD monovalent vaccines. Depending on this result, the trivalent vaccine was formulated as 2.2 μg of146S payload from each virus type/dose with equal volume of montanide ISA206 oil as adjuvant. For more confirmation theprepared trivalent vaccine potency was evaluated by Guinea pig protective dose 50 which was found to be 88 GPPD .Also 50mean SNT antibody titer was detected in serum of the test Guinea pigs 1.56, 1.68 and 1.68 log /ml against FMDVserotype O 10Pan Asia-2, AIran O5 and SAT/EGY/2012 respectively in a higher level than the recommended protective titer (PT=1.2. Alsofor further confirmation the formulated trivalent vaccine which contain 2.2 μg/serotype/dose were evaluated in cattle tomeasure the antibody titer against the three serotypes and the antibody against the three serotypes were found to be higher thanthe recommended

  10. Compositional Verification with Abstraction, Learning, and SAT Solving

    Science.gov (United States)

    2015-05-01

    Compositional Verification with Abstraction, Learning , and SAT Solving Anvesh Komuravelli CMU-CS-15-102 May 2015 School of Computer Science Computer...grant number F8721-05-C-0003, and the Portuguese Science Technology Foundation. The views and conclusions contained in this document are those of the...with Abstraction, Learning , and SAT Solving 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK

  11. Satélites de comunicación

    Directory of Open Access Journals (Sweden)

    Francisco Sacristán Romero

    2015-01-01

    Full Text Available Parte de que los satélites de comunicación son unos artilugios recién nacidos y en fase de desarrolllo. Describe la trayectoria histórica de éstos tres, el uso del satélite y el servicio de televisión, las redes, el HISPASAT enlace entre España y América dificultades y soluciones.

  12. PhoneSat In-flight Experience Results

    Science.gov (United States)

    Salas, Alberto Guillen; Attai, Watson; Oyadomari, Ken Y.; Priscal, Cedric; Schimmin, Rogan S.; Gazulla, Oriol Tintore; Wolfe, Jasper L.

    2014-01-01

    Over the last decade, consumer technology has vastly improved its performances, become more affordable and reduced its size. Modern day smartphones offer capabilities that enable us to figure out where we are, which way we are pointing, observe the world around us, and store and transmit this information to wherever we want. These capabilities are remarkably similar to those required for multi-million dollar satellites. The PhoneSat project at NASA Ames Research Center is building a series of CubeSat-size spacecrafts using an off-the-shelf smartphone as its on-board computer with the goal of showing just how simple and cheap space can be. Since the PhoneSat project started, different suborbital and orbital flight activities have proven the viability of this revolutionary approach. In early 2013, the PhoneSat project launched the first triage of PhoneSats into LEO. In the five day orbital life time, the nano-satellites flew the first functioning smartphone-based satellites (using the Nexus One and Nexus S phones), the cheapest satellite (a total parts cost below $3,500) and one of the fastest on-board processors (CPU speed of 1GHz). In this paper, an overview of the PhoneSat project as well as a summary of the in-flight experimental results is presented.

  13. AstroSat: From Inception to Realization and Launch

    Science.gov (United States)

    Agrawal, P. C.

    2017-06-01

    The origin of the idea of AstroSat multi wavelength satellite mission and how it evolved over the next 15 years from a concept to the successful development of instruments for giving concrete shape to this mission, is recounted in this article. AstroSat is the outcome of intense deliberations in the Indian astronomy community leading to a consensus for a multi wavelength Observatory having broad spectral coverage over five decades in energy covering near-UV, far-UV, soft X-ray and hard X-ray bands. The multi wavelength observation capability of AstroSat with a suite of 4 co-aligned instruments and an X-ray sky monitor on a single satellite platform, imparts a unique character to this mission. AstroSat owes its realization to the collaborative efforts of the various ISRO centres, several Indian institutions, and a few institutions abroad which developed the 5 instruments and various sub systems of the satellite. AstroSat was launched on September 28, 2015 from India in a near equatorial 650 km circular orbit. The instruments are by and large working as planned and in the past 14 months more than 200 X-ray and UV sources have been studied with it. The important characteristics of AstroSat satellite and scientific instruments will be highlighted.

  14. Fate and transport of carbamazepine in soil aquifer treatment (SAT) infiltration basin soils.

    Science.gov (United States)

    Arye, Gilboa; Dror, Ishai; Berkowitz, Brian

    2011-01-01

    The transport and fate of the pharmaceutical carbamazepine (CBZ) were investigated in the Dan Region Reclamation Project (SHAFDAN), Tel-Aviv, Israel. Soil samples were taken from seven subsections of soil profiles (150 cm) in infiltration basins of a soil aquifer treatment (SAT) system. The transport characteristics were studied from the release dynamics of soil-resident CBZ and, subsequently, from applying a pulse input of wastewater containing CBZ. In addition, a monitoring study was performed to evaluate the fate of CBZ after the SAT. Results of this study indicate adsorption, and consequently retardation, in CBZ transport through the top soil layer (0-5 cm) and to a lesser extent in the second layer (5-25 cm), but not in deeper soil layers (25-150 cm). The soluble and adsorbed fractions of CBZ obtained from the two upper soil layers comprised 45% of the total CBZ content in the entire soil profile. This behavior correlated to the higher organic matter content observed in the upper soil layers (0-25 cm). It is therefore deduced that when accounting for the full flow path of CBZ through the vadose zone to the groundwater region, the overall transport of CBZ in the SAT system is essentially conservative. The monitoring study revealed that the average concentration of CBZ decreased from 1094 ± 166 ng L⁻¹ in the recharged wastewater to 560 ± 175 ng L⁻¹ after the SAT. This reduction is explained by dilution of the recharged wastewater with resident groundwater, which may occur as it flows to active reclamation wells. Copyright © 2010 Elsevier Ltd. All rights reserved.

  15. Greater Volume but not Higher Density of Abdominal Aortic Calcium Is Associated With Increased Cardiovascular Disease Risk: MESA (Multi-Ethnic Study of Atherosclerosis).

    Science.gov (United States)

    Forbang, Nketi I; Michos, Erin D; McClelland, Robyn L; Remigio-Baker, Rosemay A; Allison, Matthew A; Sandfort, Veit; Ix, Joachim H; Thomas, Isac; Rifkin, Dena E; Criqui, Michael H

    2016-11-01

    Abdominal aortic calcium (AAC) and coronary artery calcium (CAC) independently and similarly predict cardiovascular disease (CVD) events. The standard AAC and CAC score, the Agatston method, upweights for greater calcium density, thereby modeling higher calcium density as a CVD hazard. Computed tomography scans were used to measure AAC and CAC volume and density in a multiethnic cohort of community-dwelling individuals, and Cox proportional hazard was used to determine their independent association with incident coronary heart disease (CHD, defined as myocardial infarction, resuscitated cardiac arrest, or CHD death), cardiovascular disease (CVD, defined as CHD plus stroke and stroke death), and all-cause mortality. In 997 participants with Agatston AAC and CAC scores >0, the mean age was 66±9 years, and 58% were men. During an average follow-up of 9 years, there were 77 CHD, 118 CVD, and 169 all-cause mortality events. In mutually adjusted models, additionally adjusted for CVD risk factors, an increase in ln(AAC volume) per standard deviation was significantly associated with increased all-cause mortality (hazard ratio=1.20; 95% confidence interval, 1.08-1.33; P<0.01) and an increased ln(CAC volume) per standard deviation was significantly associated with CHD (hazard ratio=1.17; 95% confidence interval, 1.04-1.59; P=0.02) and CVD (hazard ratio=1.20; 95% confidence interval, 1.05-1.36; P<0.01). In contrast, both AAC and CAC density were not significantly associated with CVD events. The Agatston method of upweighting calcium scores for greater density may be inappropriate for CVD risk prediction in both the abdominal aorta and coronary arteries. © 2016 American Heart Association, Inc.

  16. CRUCIAL: CryoSat+ Land and Inland Water

    Science.gov (United States)

    Berry, Philippa; Smith, Richard; Salloway, Mark; Lucas, Bruno Manuel; Dinardo, Salvatore; Benveniste, Jérôme

    2013-04-01

    The CryoSat-2 SIRAL altimeter presents a unique opportunity for inland water height retrieval. In order to maximise the potential of this new dataset the ESA CRUCIAL (CryoSat+ Land and Inland Water) contract has been set up to investigate the application of CryoSat-2 data over land and inland water. When operating in SAR mode CryoSat-2 obtains waveforms at an unprecedented resolution alongtrack, allowing far smaller inland water targets then previously possible to be acquired. Prior work performed with the Envisat Individual echoes has shown that a high Pulse Repetition Frequency (PRF) allows successful measurements to be obtained from river targets as small as 25m across. SAR Full Bit Rate (FBR) data are acquired over the Mekong River area, including the Mekong Delta itself. This region provides the ideal test-bed for obtaining small target inland water measurements and early results of FBR waveform reconstruction and analysis are presented within this paper. Whilst FBR data over land are available in a few test regions, over much of the Earth's land surface measurements are acquired in Low Resolution Mode. These data are comparable to those obtained by conventional altimeters, such as ERS-2 and EnviSat. The non-repeat orbit of CryoSat-2 presents a new challenge to inland water measurement by satellite radar altimetry, as repeat time-series are no longer possible. However, CryoSat-2 data produce stage measurements from along the course of rivers more regularly than the 35-days of previous ESA missions. New methodologies must be investigated to allow hydrologists to harness the full benefit of these new data. This paper presents initial findings of investigations over major river systems captured in LRM mode and a first look at results over the Mekong area from SAR FBR. This additional data will also be used to enhance and improve the Altimetry Corrected Elevations (ACE2) Global Digital Elevation Models.

  17. A Comparison of the SOCIT and DebriSat Experiments

    Science.gov (United States)

    Ausay, E.; Cornejo, A.; Horn, A.; Palma, K.; Sato, T.; Blake, B.; Pistella, F.; Boyle, C.; Todd, N.; Zimmerman, J.; hide

    2017-01-01

    This paper explores the differences between, and shares the lessons learned from, two hypervelocity impact experiments critical to the update of Department of Defense (DOD) and National Aeronautics and Space Administration (NASA) satellite breakup models. The procedures as well as the processes of the fourth Satellite Orbital Debris Characterization Impact Test (SOCIT4) were analyzed and related to the ongoing DebriSat experiment. SOCIT4 accounted for about 90% of the entire satellite mass, but only analyzed approximately 59% with a total of approximately 4,700 fragments. DebriSat aims to recover and analyze 90% of the initial mass and to do so, fragments with at least a longest dimension of 2 mm are collected and processed. DebriSat's use of modern materials, especially carbon fiber, significantly increases the fragment count and to date, there are over 126,000 fragments collected. Challenges, such as procedures and human inputs, encountered throughout the DebriSat experiment are also shared. While, SOCIT4 laid the foundation for the majority of DebriSat processes, the technological advancements since SOCIT4 allow for more accurate, rigorous, and in-depth, procedures that will aid the update of satellite breakup models.

  18. A novel solid-angle tomosynthesis (SAT) scanning scheme.

    Science.gov (United States)

    Zhang, Jin; Yu, Cedric

    2010-08-01

    Digital tomosynthesis (DTS) recently gained extensive research interests in both diagnostic and radiation therapy fields. Conventional DTS images are generated by scanning an x-ray source and flat-panel detector pair on opposite sides of an object, with the scanning trajectory on a one-dimensional curve. A novel tomosynthesis method named solid-angle tomosynthesis (SAT) is proposed, where the x-ray source scans on an arbitrary shaped two-dimensional surface. An iterative algorithm in the form of total variation regulated expectation maximization is developed for SAT image reconstruction. The feasibility and effectiveness of SAT is corroborated by computer simulation studies using three-dimensional (3D) numerical phantoms including a 3D Shepp-Logan phantom and a volumetric CT image set of a human breast. SAT is able to cover more space in Fourier domain more uniformly than conventional DTS. Greater coverage and more isotropy in the frequency domain translate to fewer artifacts and more accurately restored features in the in-plane reconstruction. Comparing with conventional DTS, SAT allows cone-shaped x-ray beams to project from more solid angles, thus provides more coverage in the spatial-frequency domain, resulting in better quality of reconstructed image.

  19. Modeling Tidal Stresses on Planetary Bodies Using an Enhanced SatStress GUI

    Science.gov (United States)

    Patthoff, D. A.; Pappalardo, R. T.; Tang, L.; Kay, J.; Kattenhorn, S. A.

    2014-12-01

    Icy and rocky satellites of our solar system display a wide range of structural deformation on their surfaces. Some surfaces are old and heavily cratered showing little evidence for recent tectonism while other surfaces are sparsely cratered and young, with some moons showing geologically very recent or present-day activity. The young deformation can take the form of small cracks in the surface, large double ridges that can extend for thousands of km, and mountain ranges that can reach heights of several kilometers. Many of the potential sources of stress that can deform the surfaces are likely tied to the diurnal tidal deformation of the moons as they orbit their parent planets. Other secular sources of global-scale stress include: volume change induced by the melting or freezing of a subsurface liquid layer, change in the orbital parameters of the moon, or rotation of the outer shell of the satellite relative to the rest of the body (nonsynchronous rotation or true polar wander). We turn to computer modeling to correlate observed structural features to the possible stresses that created them. A variety of modeling programs exist and generally assume a thin ice shell and/or a multi-layered viscoelastic satellite. The program SatStress, which was developed by Zane Crawford and documented by Wahr et al. (2009), computes tidal and nonsynchronous rotation stresses on a satellite. It was later modified into a more user-friendly version with a graphical user interface (SatStress GUI) by Kay and Kattenhorn (2010). This implementation assumes a 4-layer viscoelastic body and is able to calculate stresses resulting from diurnal tides, nonsynchronous rotation, and ice shell thickening. Here we illustrate our recent enhancements to SatStress GUI and compare modeled stresses to example features observed on the surfaces of Ganymede, Europa, and Enceladus. Kay and Kattenhorn (2010) 41st LPSC, abs # 2046. Wahr et al. (2009) Icarus, 200, 188-206.

  20. LEISA: CubeSat for Ionospheric Characterization

    Science.gov (United States)

    Suddarth, S. C.; Vera, A.; Pollard, H.; Burgett, T.; King, B.; Hulem, D.; MacGillivray, J.; Montoya, M.; Stanton, W.; Trujillo, B.; Wilson, S.; Heileman, G.

    2012-12-01

    The University of New Mexico / Configurable Space Microsystems Innovation and Applications Center (COSMIAC) is designing a highly affordable research satellite called LEISA (Low Earth Ionospheric Spectrum Analyzer) to characterize Ionospheric properties that affect electromagnetic wave propagation. By measuring spectral distortion of both natural and man-made impulses LEISA will measure Total Electron Content (TEC), magnetic field strength, refractive effects, plasma properties, and higher-order electron density profile effects. Additionally, LEISA may shed light on the relationships between lightning effects and thunderstorm weather in the troposphere and the potential relationship between the acoustic/seismic events around thunderstorms and Ionospheric weather. The LEISA design effort has led to a number of innovations that may be relevant to other small science spacecraft. The design is particularly challenging because of the need to implement broadband RF reception from 20-200 MHz as well as to capture and process the resulting signals within a 1u spacecraft (10cm x 10cm x 10cm) with less than 2 watts of average available power. One particular challenge is the deployable electrically small biconic wideband UHF antenna that deploys to approximately 1.5m in length and .5 m in width. The resulting antenna system deploys from a diminutive 500 cubic centimeter volume. The remaining electronics must fit within the remaining 500 cubic centimeters, leading the team to develop a system-on-a-chip (SoC) design using a Xilinx Spartan 6 FPGA. The resulting circuit handles the spectrogram capture as well as all command and data handling functions within an average power footprint of approximately 200mW, reserving energy for analog-to-digital conversion (ADC) during capture events. LEISA builds upon prior work by Los Alamos National Laboratory with FORTE and Cibola Flight Experiment. In addition to being much more affordable, LEISA offers the potential of geo-locating events

  1. Experimental infection of giraffe (Giraffa camelopardalis) with SAT-1 and SAT-2 foot-and-mouth disease virus.

    Science.gov (United States)

    Vosloo, W; Swanepoel, S P; Bauman, M; Botha, B; Esterhuysen, J J; Boshoff, C I; Keet, D F; Dekker, A

    2011-04-01

    The potential role of giraffe (Giraffa camelopardalis) in the epidemiology and spread of foot-and-mouth disease (FMD) SAT types was investigated by experimental infection and detection of virus in excretions using virus isolation on primary pig kidney cell cultures. In two experiments separated by a period of 24 months, groups of four animals were needle infected with a SAT-1 or SAT-2 virus, respectively and two in-contact controls were kept with each group. Viraemia was detected 3-9 days post-infection and virus isolated from mouth washes and faeces only occasionally up to day 13. The SAT-1 virus was transmitted to only one in-contact control animal, probably via saliva that contained virus from vesicles in the mouth of a needle-infected animal. None of the animals infected with the SAT-2 virus had any vesicles in the mouth, and there was no evidence of transmission to the in-contact controls. No virus was detected in probang samples for the duration of the experiments (60 days post-infection), indicating that persistent infection probably did not establish with either of these isolates. Giraffe most likely do not play an important role in FMD dissemination. Transmission of infection would possibly occur only during close contact with other animals when mouth vesicles are evident. © 2010 Blackwell Verlag GmbH.

  2. Lejere der bliver sat ud af deres bolig

    DEFF Research Database (Denmark)

    Christensen, Gunvor; Nielsen, Torben Heien

    Antallet af lejere, der bliver sat ud af deres bolig, er steget i perioden 2002-06. I 2006 blev 2600 husstande, svarende til 0,1 pct. af samtlige husstande i Danmark, sat ud af deres bolig. Stigningen er især sket i de fem største byer: København, Århus, Odense, Ålborg og Esbjerg. I dette...... skal give viden om, hvilke årsager der er til, at nogle lejere bliver sat ud af deres bolig, og hvorfor der er sket en stigning i antallet af udsættelser. Den endelige afrapportering af undersøgelsen af udsættelser i Danmark vil ske i foråret 2008. Undersøgelsen er finansieret af Socialministeriet....

  3. Development and laboratory validation of a lateral flow device for the detection of serotype SAT 2 foot-and-mouth disease viruses in clinical samples.

    Science.gov (United States)

    Ferris, Nigel P; Nordengrahn, Ann; Hutchings, Geoffrey H; Paton, David J; Kristersson, Therese; Brocchi, Emiliana; Grazioli, Santina; Merza, Malik

    2010-02-01

    A lateral flow device (LFD) for the detection of foot-and-mouth disease virus (FMDV) of the SAT 2 serotype was developed using a monoclonal antibody (Mab 2H6). The performance of the LFD was evaluated in the laboratory on suspensions of vesicular epithelia: 305 positive for FMDV type SAT 2 from suspected cases of vesicular disease collected from 30 countries and 1002 samples shown to be negative for FMDV type SAT 2 collected from 67 countries between 1968 and 2008. The diagnostic sensitivity of the LFD for FMDV type SAT 2 was higher at 88% compared to 79% obtained by the reference method of antigen ELISA, and the diagnostic specificity of the LFD was approximately 99% compared to 100% for the ELISA. The device recognized FMDV strains of wide diversity within the FMDV SAT 2 serotype and gave a superior performance for their detection compared to the 1F10 LFD which had been developed previously and shown to perform less well for the detection of FMDVs of this particular serotype. Reactions in the SAT 2 2H6 LFD with the viruses of other FMDV serotypes and swine vesicular disease (which produces a clinically indistinguishable syndrome in pigs), did not occur. These data illustrate the potential for the LFD to be employed to complement the 1F10 device next to the animal in the pen-side diagnosis of FMD, for providing rapid and objective support to veterinarians in their clinical judgment of the disease and for specific confirmation of a FMDV type SAT 2 infection. 2009 Elsevier B.V. All rights reserved.

  4. Solar Electric Propulsion CubeSat Bus for Deep Space Missions Project

    Data.gov (United States)

    National Aeronautics and Space Administration — As electronics continue to shrink in size, the capabilities of CubeSats continues to expand. CubeSats can now perform a wide range of sensing and telecommunications...

  5. AIRS-CloudSat cloud mask and radar reflectivities collocation indexes V3.1

    Data.gov (United States)

    National Aeronautics and Space Administration — This is AIRS-AMSU-CloudSat collocation indexes, in ASCII format. These data map CloudSat profile indexes to the collocated AMSU field of views, and AIRS IR...

  6. AIRS-CloudSat cloud mask, radar reflectivities, and cloud classification matchups V3.2

    Data.gov (United States)

    National Aeronautics and Space Administration — This is AIRS-CloudSat collocated subset, in NetCDF 4 format. These data contain collocated: AIRS Level 1b radiances spectra, CloudSat radar reflectivities, and MODIS...

  7. Integrated CubeSat ADACS with Reaction Wheels and Star Tracker Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The MAI-400SS Space Sextant is a precision attitude determination and control system for CubeSats and Nanosats. The MAI-400SS enables future CubeSat missions with...

  8. CubeSat Power Management Controller and Solar Array Articulation System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The CubeSat platform represents a valuable architecture from which to develop satellite capabilities, payloads and technologies. However, CubeSat spacecraft must be...

  9. On the satisfiability of random regular signed SAT formulas

    CERN Document Server

    Laus, Christian

    2011-01-01

    Regular signed SAT is a variant of the well-known satisfiability problem in which the variables can take values in a fixed set V \\subset [0,1], and the `literals' have the form "x \\le a" or "x \\ge a". We answer some open question regarding random regular signed k-SAT formulas: the probability that a random formula is satisfiable increases with |V|; there is a constant upper bound on the ratio m/n of clauses m over variables n, beyond which a random formula is asypmtotically almost never satisfied; for k=2 and V=[0,1], there is a phase transition at m/n=2.

  10. CryoSat-2 Altimetry Applications over Rivers and Lakes

    OpenAIRE

    Liguang Jiang; Raphael Schneider; Andersen, Ole B.; Peter Bauer-Gottwein

    2017-01-01

    Monitoring the variation of rivers and lakes is of great importance. Satellite radar altimetry is a promising technology to do this on a regional to global scale. Satellite radar altimetry data has been used successfully to observe water levels in lakes and (large) rivers, and has also been combined with hydrologic/hydrodynamic models. Except CryoSat-2, all radar altimetry missions have been operated in conventional low resolution mode with a short repeat orbit (35 days or less). CryoSat-2, c...

  11. Performing High-Quality Science on CubeSats

    DEFF Research Database (Denmark)

    H. Zurbuchen, Thomas; von Steiger, Rudolf; Bartalev, Sergey

    2016-01-01

    January 2016 the International Space Science Institute in Berne, Switzerland,hosted a two-day Forum to focus on the rapid evolution of CubeSats as an enabling technology platform, with special emphasis on their promise to perform high-quality science.The Forum was initiated in coordination...... in this area of research. Our discussions focused on four themes characteristic of CubeSats and their evolution: 1) identification of appropriate science in avariety of research disciplines, 2) technology development, 3) international vs. national approaches, and 4) educational benefits. These discussions...

  12. Radiation Tolerant, FPGA-Based SmallSat Computer System

    Science.gov (United States)

    LaMeres, Brock J.; Crum, Gary A.; Martinez, Andres; Petro, Andrew

    2015-01-01

    The Radiation Tolerant, FPGA-based SmallSat Computer System (RadSat) computing platform exploits a commercial off-the-shelf (COTS) Field Programmable Gate Array (FPGA) with real-time partial reconfiguration to provide increased performance, power efficiency and radiation tolerance at a fraction of the cost of existing radiation hardened computing solutions. This technology is ideal for small spacecraft that require state-of-the-art on-board processing in harsh radiation environments but where using radiation hardened processors is cost prohibitive.

  13. A new assay for determining ganglioside sialyltransferase activities lactosylceramide-2,3-sialyltransferase (SAT I) and monosialylganglioside-2,3-sialyltransferase (SAT IV).

    Science.gov (United States)

    Sun, Cynthia Q; Hubl, Ulrike; Hoefakker, Petra; Vasudevamurthy, Madhusudan K; Johnson, Keryn D

    2014-01-01

    A new assay for the determination of lactosylceramide-2,3-sialyltransferase (SAT I, EC 2.4.99.9) and monosialoganglioside sialyltransferase (SAT IV, EC 2.4.99.2) is described. The assay utilised the commercially available fluorophore labelled sphingolipids, boron dipyrromethene difluoride (BODIPY) lactosylceramide (LacCer), and BODIPY-monosialotetrahexosylganglioside (GM1) as the acceptor substrates, for SAT I and SAT IV, respectively. HPLC coupled with fluorescence detection was used to analyse product formation. The analysis was performed in a quick and automated fashion. The assay showed good linearity for both BODIPY sphingolipids with a quantitative detection limit of 0.05 pmol. The high sensitivity enabled the detection of SAT I and SAT IV activities as low as 0.001 μU, at least 200 fold lower than that of most radiometric assays. This new assay was applied to the screening of SAT I and SAT IV activities in ovine and bovine organs (liver, heart, kidney, and spleen). The results provided evidence that young animals, such as calves, start to produce ganglioside sialyltransferases as early as 7 days after parturition and that levels change during maturation. Among the organs tested from a bovine source, spleen had the highest specific ganglioside sialyltransferase activity. Due to the organ size, the greatest total ganglioside sialyltransferase activities (SAT I and SAT IV) were detected in the liver of both bovine and ovine origin.

  14. Landscape of Higher Education: Human Capital

    Science.gov (United States)

    Edwards, Kelcey; Sawtell, Ellen; Perfetto, Greg; Shapiro, Douglas T.; Kelly, Patrick J.

    2013-01-01

    In this session presented at the Middle States Regional Forum (February 2013), experts working with national data presented trends in higher education from a forward-looking perspective. Senior researchers from the College Board provided trends using SAT, AP, and Net Price Calculator data. The research director of the National Student…

  15. The Effect of Personality Preferences on the 2005 Version of the SAT

    Science.gov (United States)

    Burrs, Ashley

    2013-01-01

    Some researchers suggest the Scholastic Aptitude Test (SAT) is biased toward certain personality types. Extant literature lacked examination of personality constructs and their relationship with SAT scores of the newly revised SAT. The purpose of this study was two-fold. First, this study examined the relationship between the Sensing and Intuition…

  16. The Rise and Demise of the SAT: The University of California Generates Change for College Admissions

    Science.gov (United States)

    Berger, Susan J.

    2012-01-01

    Over the past few months, news about the Scholastic Assessment Test (SAT) has made national headlines and not in a good way: "Large SAT Score Decline Shows Failure of No Child Left Behind and State High-Stakes Testing Strategy" (FairTest 2011); "Eshaghoff, Emory University Student, Allegedly Took SAT For Other Students"…

  17. An Alternative Presentation of Incremental Validity: Discrepant SAT and HSGPA Performance

    Science.gov (United States)

    Mattern, Krista D.; Shaw, Emily J.; Kobrin, Jennifer L.

    2011-01-01

    This study examined discrepant high school grade point average (HSGPA) and SAT performance as measured by the difference between a student's standardized SAT composite score and standardized HSGPA. The SAT-HSGPA discrepancy measure was used to examine whether certain students are more likely to exhibit discrepant performance and in what direction.…

  18. Campaign for vicarious calibration of SumbandilaSat in Argentina

    CSIR Research Space (South Africa)

    Vhengani, LM

    2011-07-01

    Full Text Available to estimate Top-Of-Atmosphere (TOA) spectral radiance. A vicarious calibration field campaign was executed in Argentina to support monitoring of the radiometric response of the multispectral imager aboard SumbandilaSat. Results obtained using two Radiative...

  19. The New SAT and Education Reform in the 1990s.

    Science.gov (United States)

    Rigol, Gretchen W.

    1994-01-01

    The process by which the new Scholastic Aptitude Test (SAT) and achievement tests were developed is outlined, highlighting the evolution of new formats and emphases. It is proposed that the tests, which incorporate extensive changes, encourage genuine learning and respond to increasing cultural diversity in the population. (MSE)

  20. Revalidation of the Sat-Chit-Ananda Scale.

    Science.gov (United States)

    Singh, Kamlesh; Khanna, Pulkit; Khosla, Meenakshi; Rapelly, Mounica; Soni, Akarsh

    2016-11-18

    Sat-Chit-Ananda is an indigenous construct that refers to absolute bliss and consciousness. The present study aimed to strengthen the psychometric properties of the newly developed Sat-Chit-Ananda scale (Singh et al. in Int J Vedic Found Manag 1(2):54-74, 2014). A total of 398 students aged 17-36 years (mean age = 21.33 years, SD = 2.2, 70% males) participated in this study. An exploratory as well as confirmatory factor analysis was computed for the 17-item scale. Its' concurrent validity was established by assessing its correlation with other well-being measures, namely Flourishing (Diener et al. in Soc Indic Res 97:143-156 2010) and Scale of Positive and Negative Experience (Diener et al. 2010). Satisfactory results were obtained from both exploratory and confirmatory factor analyses. Sat-Chit-Ananda and its factors were found to be significantly positively correlated with Flourishing and Positive Experiences and were negatively correlated with Negative Experiences. Thus, the validity of the Sat-Chit-Ananda (Singh et al. 2014) scale stands further substantiated-offering this scale as a promising new assessment tool.

  1. Data Mining the University: College GPA Predictions from SAT Scores

    CERN Document Server

    Hsu, Stephen D H

    2010-01-01

    We analyze a data set comprised of academic records of undergraduates at the University of Oregon from 2000-2004. We find correlations of roughly 0.35 to 0.5 between SAT scores and upper division, in-major GPA (henceforth, GPA). Interestingly, low SAT scores do not preclude high performance in most majors. That is, the distribution of SAT scores after conditioning on high GPA (e.g., 3.5 or even 4.0) typically extends below 1000 (the average among test takers). We hypothesize that "overachievers" overcome cognitive deficits through hard work, and discuss to what extent they can be identified from high school records. Only a few majors seem to exhibit a "cognitive threshold" -- such that high GPA (mastery of the subject matter) is very unlikely below a certain SAT threshold (i.e., no matter how dedicated or hard working the student). Our results suggest that almost any student admitted to university can achieve academic success, if they work hard enough. In addition to our primary result, we find that the best ...

  2. A Validation Dataset for CryoSat Sea Ice Investigators

    DEFF Research Database (Denmark)

    Julia, Gaudelli,; Baker, Steve; Haas, Christian

    provides an independent metric that can be used to objectively evaluate any experimental changes or refinements to the CryoSat data processing that a user may wish to test. This valuable resource is in itself an output of the CryoVal-SI project which is made openly and freely available to the scientific...

  3. CloudSat Reflectivity Data Visualization Inside Hurricanes

    Science.gov (United States)

    Suzuki, Shigeru; Wright, John R.; Falcon, Pedro C.

    2011-01-01

    We have presented methods to rapidly produce visualization and outreach products from CloudSat data for science and the media These methods combine data from several sources in the product generation process In general, the process can be completely automatic, producing products and notifying potential users

  4. NexSat: Previewing NPOESS/VIIRS Imagery Capabilities.

    Science.gov (United States)

    Miller, Steven D.; Hawkins, Jeffrey D.; Kent, John; Turk, F. Joseph; Lee, Thomas F.; Kuciauskas, Arunas P.; Richardson, Kim; Wade, Robert; Hoffman, Carl

    2006-04-01

    Under the auspices of the National Polar-orbiting Operational Environmental Satellite System's (NPOESS) Integrated Program Office (IPO), the Naval Research Laboratory (NRL) has developed "NexSat" (http://www.nrlmry.navy.mil/nexsat_pages/nexsat_home.html public-access online demonstration over the continental United States (CONUS) of near-real-time environmental products highlighting future applications from the Visible/Infrared Imager/Radiometer Suite (VIIRS). Based on a collection of operational and research-grade satellite observing systems, Nex-Sat products include the detection, enhancement, and where applicable, physical retrieval of deep convection, low clouds, light sources at night, rainfall, snow cover, aircraft contrails, thin cirrus layers, dust storms, and cloud/ aerosol properties, all presented in the context of value-added imagery. The purpose of NexSat is threefold: 1) to communicate the advanced capabilities anticipated from VIIRS, 2) to present this information in near-real time for use by forecasters, resource managers, emergency response teams, civic planners, the aviation community, and various government agencies, and 3) to augment the NRL algorithm development multisensor/model-fusion test bed for accelerated transitions to operations during the NPOESS era. This paper presents an overview of NexSat, highlighting selected products from the diverse meteorological phenomenology over the CONUS.

  5. Soft X-ray focusing Telescope aboard AstroSat

    DEFF Research Database (Denmark)

    Singh, K. P.; Dewangan, G. C.; Chandra, S.

    2017-01-01

    The Soft X-ray focusing Telescope (SXT) is a moderateresolution X-ray imaging spectrometer supplementing the ultraviolet and hard X-ray payloads for broadband studies of cosmic sources with AstroSat. Well suited for observing bright X-ray sources, SXT observations of nearby active galactic nuclei...

  6. Sats14: Hurtig indsats over for frafaldstruede produktionsskoleelever

    DEFF Research Database (Denmark)

    Frølunde, Lisbeth; Hansen, Susanne Pihl; Andreasen, Lars Birch

    Sats 14 projektet drejede sig om at undersøge mulighederne i lokalt at tilbyde fx psykologbistand, social- eller specialpædagogisk bistand til produktionsskoleelever med særlige behov. Evalueringen fremhæver projektets resultater og vigtigste pointer: at en stor gruppe elever kan blive hjulpet til...

  7. Exponential Lower Bounds for the PPSZ k-SAT Algorithm

    DEFF Research Database (Denmark)

    Chen, Shiteng; Scheder, Dominik Alban; Talebanfard, Navid

    2013-01-01

    In 1998, Paturi, Pudl´ak, Saks, and Zane presented PPSZ, an elegant randomized algorithm for k-SAT. Fourteen years on, this algorithm is still the fastest known worst-case algorithm. They proved that its expected running time on k-CNF formulas with n variables is at most 2(1−k)n, where k 2 (1/k...

  8. The COLD-SAT experiment for cryogenic fluid management technology

    Science.gov (United States)

    Schuster, J. R.; Wachter, J. P.; Vento, D. M.

    1990-01-01

    The COLD-SAT spacecraft design experiments are described. COLD-SAT will be placed into an initial 1300 km circular orbit by an Atlas commercial launch vehicle. Electric power, experiment control and data management, attitude control, and propulsive accelarations for the experiments will be provided by the three-axis-controlled spacecraft bus. To provide data on the effects that low gravity levels might have on the heat and mass transfer processes involved, low levels of accelaration will be created. The COLD-SAT experiment will be configured into a module. The spacecraft experiment module will include three liquid hydrogen tanks; fluid transfer, pressurization and venting equipment; and instrumentation. Since the largest tank has helium-purged MLI to prevent ingress and freezing of air on the launchpad, it will contain all the liquid hydrogen at the point of launching. The hydrogen tanking system used for the Centaur upper stage of the Atlas will load and top off this tank. Atlas, with its liquid hydrogen upper stage, large payload fairing, and large launch margin, simplifies COLD-SAT design and integration.

  9. The autonomous vision system on TeamSat

    DEFF Research Database (Denmark)

    Betto, Maurizio; Jørgensen, John Leif; Riis, Troels

    1999-01-01

    The second qualification flight of Ariane 5 blasted off-the European Space Port in French Guiana on October 30, 1997, carrying on board a small technology demonstration satellite called TeamSat. Several experiments were proposed by various universities and research institutions in Europe and five...

  10. Malaria Early Warning: The MalarSat project

    Science.gov (United States)

    Roca, M.; Escorihuela, M. J.; Martínez, D.; Torrent, M.; Aponte, J.; Nunez, F.; Garcia, J.

    2009-04-01

    Malaria is one of the major public health challenges undermining development in the world. The aim of MalarSat Project is to provide a malaria risks infection maps at global scale using Earth Observation data to support and prevent epidemic episodes. The proposed service for creating malaria risk maps would be critically useful to improve the efficiency in insecticide programs, vaccine campaigns and the logistics epidemic treatment. Different teams have already carried out studies in order to exploit the use of Earth Observation (EO) data with epidemiology purposes. In the case of malaria risk maps, it has been shown that meteorological data is not sufficient to fulfill this objective. In particular being able to map the malaria mosquito habitat would increase the accuracy of risk maps. The malaria mosquitoes mainly reproduce in new water puddles of very reduced dimensions (about 1 meter wide). There is no instrument that could detect such small patches of water unless there are many of them spread in an area of several hundreds of meters. MalarSat aims at using the radar altimeter data from the EnviSat, RA-2, to try and build indicators of mosquitoes existence. This presentation will show the scientific objectives and principles of the MalarSat project.

  11. Beyond Individual Differences: Exploring School Effects on SAT Scores

    Science.gov (United States)

    Everson, Howard T.; Millsap, Roger E.

    2004-01-01

    This article explores the complex, hierarchical relation among school characteristics, individual differences in academic achievement, extracurricular activities, and socioeconomic background on performance on the verbal and mathematics Scholastic Aptitude Test (SAT). Using multilevel structural equation models (SEMs) with latent means, we…

  12. AMF3 CloudSat Overpasses Field Campaign Report

    Energy Technology Data Exchange (ETDEWEB)

    Matrosov, Sergey [University of Colorado, Boulder; National Oceanic and Atmospheric Administration (NOAA), Boulder, CO (United States). Earth System Research Lab.; Hardin, Joseph [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); De Boer, Gijs [University of Colorado, Boulder; National Oceanic and Atmospheric Administration (NOAA), Boulder, CO (United States). Earth System Research Lab.; Shupe, Matthew [University of Colorado, Boulder; National Oceanic and Atmospheric Administration (NOAA), Boulder, CO (United States). Earth System Research Lab.; Maahn, Maximillian [National Oceanic and Atmospheric Administration (NOAA), Boulder, CO (United States). Earth System Research Lab.; Williams, Christopher [University of Colorado, Boulder; National Oceanic and Atmospheric Administration (NOAA), Boulder, CO (United States). Earth System Research Lab.

    2017-10-15

    Synergy between ground-based and satellite radar observations of clouds and precipitation is important for refining the algorithms to retrieve hydrometeor microphysical parameters, improvements in the retrieval accuracy, and better understanding the advantages and limitations of different retrieval approaches. The new dual-frequency (Ka- and W-band, 35 GHz and 94 GHz) fully polarimetric scanning U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Research Facility cloud radars (SACRs-2) are advanced sensors aimed to significantly enhance remote sensing capabilities (Kollias et al. 2016). One of these radars was deployed as part of the third ARM Mobile Facility (AMF3) at Oliktok Point, Alaska (70.495o N, 149.886oW). The National Aeronautics and Space Administration (NASA) CloudSat satellite, which is part of the polar-orbiting A-train satellite constellation, passes over the vicinity of the AMF3 location (typically within 0-7 km depending on a particular overpass) on a descending orbit every 16 days at approximately 13:21 UTC. The nadir pointing W-band CloudSat cloud profiling radar (CPR) provides vertical profiles of reflectivity that are then used for retrievals of hydrometeor parameters (Tanelli et al. 2008). The main objective of the AMF3 CloudSat overpasses intensive operating period (IOP) campaign was to collect approximately collocated in space and time radar data from the SACR-2 and the CloudSat CPR measurements for subsequent joint analysis of radar variables and microphysical retrievals of cloud and precipitation parameters. Providing the reference for the SACR-2 absolute calibration from the well-calibrated CloudSat CPR was another objective of this IOP. The IOP objectives were achieved by conducting seven special SACR-2 scans during the 10.5-min period centered at the exact time of the CloudSat overpass over the AMF3 (~1321 UTC) on six dates of the CloudSat overpasses during the three-month period allocated to this IOP. These six days

  13. COMPARATIVE STUDY ON EFFICACY OF ROSE BENGAL PLATE TEST (I{BPT AND SERUM AGGLUTINATION TEST (SAT FOR DETECTING THE INCIDENE OF BRUCELLOSIS IN BUFFALOES (Bubolus bubolis

    Directory of Open Access Journals (Sweden)

    Idrees Ali Zahid, Ishtiaq Ahmad and Umer Hayat

    2002-03-01

    Full Text Available Rose Bengal Plate Test (RBPT and Serum Agglutination Test (SAT were applied for the diagnosis of brucellosis in 240 buffaloes maintained at organized livestock farms in Punjab, to measure their comparative efficacy. Based on RBPT and SAT, 11.25 (n=27 and 10.42 percent (n=25 buffaloes were found seropositive, 11.67 (n 28 and 4.58 percent (n= 11 animals showed doubtful results, while 77.08 (n= 185 and 85 percept (n= 204 animals were found seronegative, respectively. Rose Bengal Plate Test detected higher percentages of seropositive, doubtful and seronegative cases than those detected by Serum Agglutination Test, which showed lower percentages or seropositive, doubtful and seronegative cases. This study indicated that SAT is more sensitive and reliable diagnostic test for the detection of Brucella aborlus, antibodies in buffaloes.

  14. Modelling Stresses on Icy Satellites: Upgrading SatStressGUI

    Science.gov (United States)

    Harper, Chad; Pappalardo, Robert T.; Patthoff, Alex; Doan, Nhu

    2017-10-01

    SatStressGUI is a program that calculates surface stresses resulting from candidate stress sources, specifically: diurnal tidal forces, nonsynchronous rotation, ice shell thickening, obliquity, and orbital migration on icy and rocky satellites. SatStressGUI is designed to enable quick calculations and easy to create stress field visuals. Here we report on recent upgrades to SatStressGUI; specifically, enabling it to calculate stresses resulting from obliquity driven stressing in a viscoelastic regime. We define obliquity as the tilt of the satellite’s equatorial plane relative to the orbital plane. Obliquity driven stresses cause asymmetric stress fields about the equator. The resulting asymmetries can affect the orientation of the principal stresses and thereby result in the arcuate (as opposed to boxy) cycloid patterns seen in some icy satellites and allow for fractures to propagate across the equator. In the past, SatStressGUI had the ability to calculate obliquity stresses only for an elastic body; however, icy satellites are better described as viscoelastic bodies. As a result of our recent upgrades; these stress fields, which can result in the formation of surface features such as the lineaments and cycloids found on Europa, can now be more accurately simulated. We used an obliquity model that follows the calculations the calculations of Hermes et al. (Icarus, 215, 417-438, 2011), which takes a closer look at the effects of a non-zero obliquity in a viscoelastic regime. By the calculations of Hermes et al. (Icarus, 215, 417-438, 2011), accounting for viscoelastic behavior of ice could result in a westward shift of the entire stress field. By permitting simulation of surface features from various tidal stresses and comparison them to observations, SatStressGUI can help us gain insight into icy bodies’ deformation history: a history which can better informing our predictions about the interiors and geological histories of satellites such as Europa.

  15. Interpreting force concept inventory scores: Normalized gain and SAT scores

    Directory of Open Access Journals (Sweden)

    Vincent P. Coletta

    2007-05-01

    Full Text Available Preinstruction SAT scores and normalized gains (G on the force concept inventory (FCI were examined for individual students in interactive engagement (IE courses in introductory mechanics at one high school (N=335 and one university (N=292, and strong, positive correlations were found for both populations (r=0.57 and r=0.46, respectively. These correlations are likely due to the importance of cognitive skills and abstract reasoning in learning physics. The larger correlation coefficient for the high school population may be a result of the much shorter time interval between taking the SAT and studying mechanics, because the SAT may provide a more current measure of abilities when high school students begin the study of mechanics than it does for college students, who begin mechanics years after the test is taken. In prior research a strong correlation between FCI G and scores on Lawson’s Classroom Test of Scientific Reasoning for students from the same two schools was observed. Our results suggest that, when interpreting class average normalized FCI gains and comparing different classes, it is important to take into account the variation of students’ cognitive skills, as measured either by the SAT or by Lawson’s test. While Lawson’s test is not commonly given to students in most introductory mechanics courses, SAT scores provide a readily available alternative means of taking account of students’ reasoning abilities. Knowing the students’ cognitive level before instruction also allows one to alter instruction or to use an intervention designed to improve students’ cognitive level.

  16. Interpreting force concept inventory scores: Normalized gain and SAT scores

    Directory of Open Access Journals (Sweden)

    Jeffrey J. Steinert

    2007-05-01

    Full Text Available Preinstruction SAT scores and normalized gains (G on the force concept inventory (FCI were examined for individual students in interactive engagement (IE courses in introductory mechanics at one high school (N=335 and one university (N=292 , and strong, positive correlations were found for both populations ( r=0.57 and r=0.46 , respectively. These correlations are likely due to the importance of cognitive skills and abstract reasoning in learning physics. The larger correlation coefficient for the high school population may be a result of the much shorter time interval between taking the SAT and studying mechanics, because the SAT may provide a more current measure of abilities when high school students begin the study of mechanics than it does for college students, who begin mechanics years after the test is taken. In prior research a strong correlation between FCI G and scores on Lawson’s Classroom Test of Scientific Reasoning for students from the same two schools was observed. Our results suggest that, when interpreting class average normalized FCI gains and comparing different classes, it is important to take into account the variation of students’ cognitive skills, as measured either by the SAT or by Lawson’s test. While Lawson’s test is not commonly given to students in most introductory mechanics courses, SAT scores provide a readily available alternative means of taking account of students’ reasoning abilities. Knowing the students’ cognitive level before instruction also allows one to alter instruction or to use an intervention designed to improve students’ cognitive level.

  17. CloudSat-Based Assessment of GPM Microwave Imager Snowfall Observation Capabilities

    Directory of Open Access Journals (Sweden)

    Giulia Panegrossi

    2017-12-01

    Full Text Available The sensitivity of Global Precipitation Measurement (GPM Microwave Imager (GMI high-frequency channels to snowfall at higher latitudes (around 60°N/S is investigated using coincident CloudSat observations. The 166 GHz channel is highlighted throughout the study due to its ice scattering sensitivity and polarization information. The analysis of three case studies evidences the important combined role of total precipitable water (TPW, supercooled cloud water, and background surface composition on the brightness temperature (TB behavior for different snow-producing clouds. A regression tree statistical analysis applied to the entire GMI-CloudSat snowfall dataset indicates which variables influence the 166 GHz polarization difference (166 ∆TB and its relation to snowfall. Critical thresholds of various parameters (sea ice concentration (SIC, TPW, ice water path (IWP are established for optimal snowfall detection capabilities. The 166 ∆TB can identify snowfall events over land and sea when critical thresholds are exceeded (TPW > 3.6 kg·m−2, IWP > 0.24 kg·m−2 over land, and SIC > 57%, TPW > 5.1 kg·m−2 over sea. The complex combined 166 ∆TB-TB relationship at higher latitudes and the impact of supercooled water vertical distribution are also investigated. The findings presented in this study can be exploited to improve passive microwave snowfall detection algorithms.

  18. CLIpSAT for Interplanetary Missions: Common Low-cost Interplanetary Spacecraft with Autonomy Technologies

    Science.gov (United States)

    Grasso, C.

    2015-10-01

    Blue Sun Enterprises, Inc. is creating a common deep space bus capable of a wide variety of Mars, asteroid, and comet science missions, observational missions in and near GEO, and interplanetary delivery missions. The spacecraft are modular and highly autonomous, featuring a common core and optional expansion for variable-sized science or commercial payloads. Initial spacecraft designs are targeted for Mars atmospheric science, a Phobos sample return mission, geosynchronous reconnaissance, and en-masse delivery of payloads using packetized propulsion modules. By combining design, build, and operations processes for these missions, the cost and effort for creating the bus is shared across a variety of initial missions, reducing overall costs. A CLIpSAT can be delivered to different orbits and still be able to reach interplanetary targets like Mars due to up to 14.5 km/sec of delta-V provided by its high-ISP Xenon ion thruster(s). A 6U version of the spacecraft form fits PPOD-standard deployment systems, with up to 9 km/s of delta-V. A larger 12-U (with the addition of an expansion module) enables higher overall delta-V, and has the ability to jettison the expansion module and return to the Earth-Moon system from Mars orbit with the main spacecraft. CLIpSAT utilizes radiation-hardened electronics and RF equipment, 140+ We of power at earth (60 We at Mars), a compact navigation camera that doubles as a science imager, and communications of 2000 bps from Mars to the DSN via X-band. This bus could form the cornerstone of a large number asteroid survey projects, comet intercept missions, and planetary observation missions. The TugBot architecture uses groups of CLIpSATs attached to payloads lacking innate high-delta-V propulsion. The TugBots use coordinated trajectory following by each individual spacecraft to move the payload to the desired orbit - for example, a defense asset might be moved from GEO to lunar transfer orbit in order to protect and hide it, then returned

  19. Secreted autotransporter toxin (Sat) triggers autophagy in epithelial cells that relies on cell detachment.

    Science.gov (United States)

    Liévin-Le Moal, Vanessa; Comenge, Yannick; Ruby, Vincent; Amsellem, Raymonde; Nicolas, Valérie; Servin, Alain L

    2011-07-01

    The secreted autotransporter toxin, Sat, which belongs to the subfamily of serine protease autotransporters of Enterobacteriaceae, acts as a virulence factor in extraintestinal and intestinal pathogenic strains of Escherichia coli. We observed that HeLa cells exposed to the cell-free culture supernatant of recombinant strain AAEC185p(Sat-IH11128) producing the Sat toxin (CFCS(Sat) ), displayed dramatic disorganization of the F-actin cytoskeleton before loosening cell-to-cell junctions and detachment. Examination of the effect of Sat on GFP-microtubule-associated protein light chain 3 (LC3) HeLa cells revealed that CFCS(Sat) -induced autophagy follows CFCS(Sat) -induced F-actin cytoskeleton rearrangement. The induced autophagy shows an acceleration of the autophagy flux soon after Sat treatment, followed later by a blockade of the flux leading to the accumulation of large GFP-LC3-positive vacuoles in the cell cytoplasm. CFCS(Sat) did not induce cell detachment in autophagy-deficient mouse embryonic fibroblasts in contrast with wild-type mouse embryonic fibroblasts. The CFCS(Sat) -induced large GFP-LC3 dots do not display the characteristics of autophagolysosomes including expression of cathepsin D and Lamp-1 and 2 proteins, and Lysotracker Red- and DQ-BSA-positive labelling. We provide evidences that CFCS(Sat) -induced autophagy is not a cell response intended to get rid of the intracellular toxin. By a pharmacological blockers approach, we found that the blockade of Erk1/2 and p38 MAPKs, but not JNK, inhibited the CFCS(Sat) -induced autophagy and cell detachment whereas phosphatidylinositol-3 kinase blockers inhibiting canonical autophagy were inactive. When attached CFCS(Sat) -treated cells start to detach they showed caspase-independent cell death and rearrangements of the focal adhesion-associated vinculin and paxillin. Collectively, our results support that Sat triggers autophagy in epithelial cells that relies on its cell-detachment effect. © 2011 Blackwell

  20. Pictures Improve Memory of SAT Vocabulary Words.

    Science.gov (United States)

    Price, Melva; Finkelstein, Arleen

    1994-01-01

    Suggests that students can improve their memory of Scholastic Aptitude Test vocabulary words by associating the words with corresponding pictures taken from magazines. Finds that long-term recall of words associated with pictures was higher than recall of words not associated with pictures. (RS)

  1. Max 2-SAT with up to 108 qubits

    Science.gov (United States)

    Santra, Siddhartha; Quiroz, Gregory; Ver Steeg, Greg; Lidar, Daniel A.

    2014-04-01

    We experimentally study the performance of a programmable quantum annealing processor, the D-Wave One (DW1) with up to 108 qubits, on maximum SAT problem with 2 variables per clause (MAX 2-SAT) problems. We consider ensembles of random problems characterized by a fixed clause density, an external parameter which we tune through its critical value in our experiments. We demonstrate that the DW1 is sensitive to the critical value of the clause density. The DW1 results are verified and compared with akmaxsat, an exact, state-of-the-art algorithm. We study the relative performance of the two solvers and how they correlate in terms of problem hardness. We find that the DW1 performance scales more favorably with problem size and that problem hardness correlation is essentially non-existent. We discuss the relevance and limitations of such a comparison.

  2. The Relationship between SAT Scores and Retention to the Second Year: 2007 SAT Validity Sample. Statistical Report No. 2011-4

    Science.gov (United States)

    Mattern, Krista D.; Patterson, Brian F.

    2011-01-01

    This report presents the findings from a replication of the analyses from the report, "Is Performance on the SAT Related to College Retention?" (Mattern & Patterson, 2009). The tables presented herein are based on the 2007 sample and the findings are largely the same as those presented in the original report, and show SAT scores are…

  3. SAT Performance: Understanding the Contributions of Cognitive/Learning and Social/Personality Factors.

    Science.gov (United States)

    Hannon, Brenda; McNaughton-Cassill, Mary

    2011-07-01

    This study identifies a number of sources of individual differences in SAT performance by examining the simultaneous contributions of factors from two otherwise disparate research areas, namely cognition/learning and social/personality. Preliminary analysis revealed that just the cognitive/learning measures accounted for 37.8, 41.4 and 21.9% of the variance in SAT, V-SAT and Q-SAT performance, respectively while just the social/personality measures accounted for 21.4, 18.2 and 17.3% of the variance. When combined, cognitive/learning and social/personality factors accounted for even larger amounts of variance in performance; specifically 43.4, 44.6 and 28% for the SAT, V-SAT and Q-SAT, respectively. Finally, the results revealed that three measures consistently predicted performance on the SAT, V-SAT and Q-SAT; two measures were the learning/cognitive factors of working memory and integration of new text-based information with information from long-term memory and one measure was the social/personality factor, test anxiety.

  4. Dietary pattern associated with selenoprotein P and MRI-derived body fat volumes, liver signal intensity, and metabolic disorders.

    Science.gov (United States)

    di Giuseppe, Romina; Plachta-Danielzik, Sandra; Koch, Manja; Nöthlings, Ute; Schlesinger, Sabrina; Borggrefe, Jan; Both, Marcus; Müller, Hans-Peter; Kassubek, Jan; Jacobs, Gunnar; Lieb, Wolfgang

    2018-02-14

    The association of complex dietary patterns with circulating selenoprotein P (SELENOP) levels in humans is unknown. In a general population sample, we aimed to identify a dietary pattern explaining inter-individual variation in circulating SELENOP concentrations and to study this pattern in relation to prevalent diabetes, metabolic syndrome (MetS), MRI-determined total volumes of visceral (VAT) and subcutaneous (SAT) abdominal adipose tissue, and liver signal intensity/fatty liver disease. In this cross-sectional study, serum SELENOP levels were measured in 853 individuals. In a subsample of 553 participants, whole-body MRI was performed to assess body fat distribution and liver fat. Dietary intake was assessed by a self-administered food frequency questionnaire and the dietary pattern identified using reduced-rank regression (RRR). Multivariable linear and logistic regressions were used to investigate associations between dietary pattern score and metabolic traits. Characterized by high intake of fruit, vegetables and antioxidant beverages, the RRR-derived dietary pattern displayed inverse associations with VAT, SAT, MetS, and prevalent diabetes in multivariable-adjusted restricted cubic splines. Each unit increase in dietary pattern score was associated with 31% higher SELENOP levels, 12% lower VAT (95% CI: - 19%; - 5%), 13% (95% CI: - 20%; - 6%) lower SAT values and 46% (95% CI: 27%; 60%) and 53% (95% CI: 22%; 72%) lower odds of having MetS or diabetes, respectively. No meaningful relations were observed between the dietary pattern and liver traits. Our observations propose diet-related regulation in SELENOP levels and that the identified dietary pattern is inversely related to VAT, SAT, MetS, and prevalent diabetes.

  5. Modular Heat Dissipation Technique for a CubeSat

    Science.gov (United States)

    2015-07-28

    30  Figure 7: TD Thin Shell Data Dialog Box...effort. When a surface or solid is created, the Thin Shell Data dialog box appears as shown in Figure 7. Figure 7: TD Thin Shell Data Dialog Box...CubeSats, because it leaves a considerable area for circuitry on the board and has a simple scheme [ Pumpkin , 2013]. Assuming there are high power

  6. CubeSat Attitude Determination and Helmholtz Cage Design

    Science.gov (United States)

    2012-03-01

    Effects of Electrical and Ferromagnetic Objects . . . . . . . . 57 4.1.2 Room Survey . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 4.2...the theory and knowledge that was incorporated into the design of the cage and the implementation of the attitude determination algorithm in this...example of a 3U CubeSat. Control for Delfi-C3 is composed of hysteresis rods which were tested via a Helmholtz cage similar to the one described in this

  7. The CubeSat Imaging X-ray Solar Spectrometer (CubIXSS) Mission Concept

    Science.gov (United States)

    Caspi, Amir; Shih, Albert Y.; Warren, Harry; DeForest, Craig; Laurent, Glenn Thomas; Schwartz, Richard A.; Woods, Thomas N.; Mason, James; Palo, Scott; Steslicki, Marek; Sylwester, Janusz; Gburek, Szymon; Mrozek, Tomasz; Kowalinski, Miroslaw; Torre, Gabriele; Crowley, Geoffrey; Schattenburg, Mark

    2017-08-01

    Solar soft X-ray (SXR) observations provide important diagnostics of plasma heating, during solar flares and quiescent times. Spectrally- and temporally-resolved measurements are crucial for understanding the dynamics, origins, and evolution of these energetic processes, providing probes both into the temperature distributions and elemental compositions of hot plasmas; spatially-resolved measurements are critical for understanding energy transport and mass flow. A better understanding of the thermal plasma improves our understanding of the relationships between particle acceleration, plasma heating, and the underlying release of magnetic energy during reconnection. We introduce a new proposed small satellite mission, the CubeSat Imaging X-ray Solar Spectrometer (CubIXSS), to measure spectrally- and spatially-resolved SXRs from the quiescent and flaring Sun from a 6U CubeSat platform in low-Earth orbit during a nominal 1-year mission. CubIXSS includes the Amptek X123-FastSDD silicon drift detector, a low-noise, commercial off-the-shelf (COTS) instrument enabling solar SXR spectroscopy from ~0.5 to ~30 keV with ~0.15 keV FWHM spectral resolution with low power, mass, and volume requirements. Multiple detectors and tailored apertures provide sensitivity to a wide range of solar conditions, optimized for a launch during solar minimum. The precise spectra from these instruments will provide detailed measurements of the coronal temperature distribution and elemental abundances from the quiet Sun to active regions and flares. CubIXSS also includes a novel spectro-spatial imager -- the first ever solar imager on a CubeSat -- utilizing a custom pinhole camera and Chandra-heritage X-ray transmission diffraction grating to provide spatially- resolved, full-Sun imaging spectroscopy from ~0.1 to ~10 keV, with ~25 arcsec and ~0.1 Å FWHM spatial and spectral resolutions, respectively. MOXSI’s unique capabilities enable SXR spectroscopy and temperature diagnostics of individual

  8. Evaluation of the Impact of an Additive Manufacturing Enhanced CubeSat Architecture on the CubeSat Development Process

    Science.gov (United States)

    2016-09-15

    structural panel radiation attenuation and mass. The following chapter will show the completed BEAM CubeSat architecture and the results of the...propulsion subsystems were subsumed by the structures subsystem in the AM-augmented architecture , the structures subsystem is mapped to all four proposed...power and propulsion subsystems were reallocated from the standalone subsystems in the baseline architecture to the structure subsystem in the BEAM

  9. "SeismoSAT" project state of the art: connecting seismic data centres via satellite

    Science.gov (United States)

    Pesaresi, Damiano; Lenhardt, Wolfgang; Rauch, Markus; Zivcic, Mladen; Steiner, Rudolf; Bertoni, Michele

    2014-05-01

    Since 2002 the OGS (Istituto Nazionale di Oceanografia e di Geofisica Sperimentale) in Udine (Italy), the Zentralanstalt für Meteorologie und Geodynamik (ZAMG) in Vienna (Austria), and the Agencija Republike Slovenije za Okolje (ARSO) in Ljubljana (Slovenia) are using the Antelope software suite as the main tool for collecting, analyzing, archiving and exchanging seismic data in real time, initially in the framework of the EU Interreg IIIa Italia-Austria project "Trans-national seismological networks in the South-Eastern Alps". The data exchange has proved to be effective and very useful in case of seismic events near the borders between Italy, Austria and Slovenia, where the poor single national seismic networks coverage precluded a correct localization, while the usage of common data from the integrated networks improves considerably the overall reliability of real time seismic monitoring of the area. At the moment the data exchange between the seismic data centres relies on internet: this however is not an ideal condition for civil protection purposes, since internet reliability is poor. For this reason in 2012 the Protezione Civile della Provincia Autonoma di Bolzano in Bolzano (Italy) joined OGS, ZAMG and ARSO in the Interreg IV Italia-Austria project "SeismoSAT" aimed in connecting the seismic data centres in real time via satellite. As it will be illustrated, the general technical schema of the project has been approved, data bandwidths and monthly volumes required have been quantified, the common satellite provider has been selected, the hardware has been purchased and installed, and the all SeismoSAT project is in testing phase.

  10. The relationship of high school graduation exams to graduation rates and SAT scores.

    Directory of Open Access Journals (Sweden)

    Gregory J. Marchant

    2005-01-01

    Full Text Available The current study examined the effect of high school graduation exams on states' graduation rates, states' aggregated SAT scores, and individual students' SAT scores. Three data sources were used: One source identified states requiring a standardized test for graduation; the NCES provided state aggregated data on graduation rates for the class of 2002; and the College Board provided its 2001 SAT database for all test-takers. After controlling for students' demographic characteristics (e.g., race, family education and income, GPA and class rank, regression analyses revealed that states requiring graduation exams had lower graduation rates and lower SAT scores. Individually, students from states requiring a graduation exam performed more poorly on the SAT than did students from states not requiring an exam. The impact of high stakes tests' on students' motivation to stay in school and on the teaching of critical thinking skills (tested by the SAT are discussed.

  11. The coastal mean dynamic topography in Norway observed by CryoSat-2 and GOCE

    DEFF Research Database (Denmark)

    Idžanović, Martina; Ophaug, Vegard; Andersen, Ole Baltazar

    2017-01-01

    New-generation synthetic aperture radar altimetry, as implemented on CryoSat-2, observes sea surface heights in coastal areas that were previously not monitored by conventional altimetry. Therefore,CryoSat-2 is expected to improve the coastal mean dynamic topography (MDT). However, the MDT remains...... highly reliant on the geoid. Using new regional geoid models as well as CryoSat-2 data, we determine three geodetic coastal MDT models in Norway and validate them against independent tide-gauge observations and the operational coastal ocean model NorKyst800. The CryoSat-2 MDTs agree on the ∼3–5 cm level...... terrestrial gravity information provided by aregional geoid model. We also find that the border of the geographical mode mask of CryoSat-2 coincides with the Norwegian Coastal Current, making it challenging to distinguish between artifacts in the CryoSat-2observations during mode switch and ocean signal....

  12. Habitual 'sleep credit' is associated with greater grey matter volume of the medial prefrontal cortex, higher emotional intelligence and better mental health.

    Science.gov (United States)

    Weber, Mareen; Webb, Christian A; Deldonno, Sophie R; Kipman, Maia; Schwab, Zachary J; Weiner, Melissa R; Killgore, William D S

    2013-10-01

    In modern society, people often fail to obtain the amount of sleep that experts recommend for good health and performance. Insufficient sleep can lead to degraded cognitive performance and alterations in emotional functioning. However, most people also acknowledge that on a regular basis they obtain more sleep than they subjectively perceive they need at a minimum to stave off performance decrements, a construct we describe as subjective 'sleep credit'. Few people would contest the notion that getting more sleep is better, but data on both behavioural and neuroanatomical correlates of 'sleep credit' are surprisingly limited. We conducted a voxel-based morphometric study to assess cerebral grey matter correlates of habitually sleeping more than one's subjective requirements. We further tested whether these structural correlates are associated with perceived emotional intelligence and indices of psychopathology while controlling for age, gender, and total intracranial volume. In a sample of 55 healthy adults aged 18-45 years (28 males, 27 females), whole-brain multiple regression showed that habitual subjective 'sleep credit' was correlated positively with grey matter volume within regions of the left medial prefrontal cortex and right orbitofrontal gyrus. Volumes were extracted and regressed against self-report emotion and psychopathology indices. Only grey matter volume of the medial prefrontal cortex cluster correlated with greater emotional intelligence and lower scores on several indices of psychopathology. Findings converge with previous evidence of the role of the medial prefrontal cortex in the relationship between sleep and emotional functioning, and suggest that behaviour and brain structure vary with habitual 'sleep credit'. © 2013 European Sleep Research Society.

  13. Lunar and Lagrangian Point L1/L2 CubeSat Communication and Navigation Considerations

    OpenAIRE

    Schaire, Scott; Wong, Yen; Bussey, George; Shelton, Marta; Folta, Dave; Gramling, Cheryl; Celeste, Peter; Anderson, Mike; Perrotto, Trish; Malphrus, Benjamin; Kruth, Jeff

    2017-01-01

    CubeSats have grown in sophistication to the point that relatively low-cost mission solutions could be undertaken for planetary exploration. There are unique considerations for lunar and L1/L2 CubeSat communication and navigation compared with low earth orbit CubeSats. This paper explores those considerations as they relate to the Lunar IceCube Mission. The Lunar IceCube is a CubeSat mission led by Morehead State University with participation from NASA Goddard Space Flight Center, Jet Propuls...

  14. Madame Satã: a potência de um corpo em cena ( Madame Satã: the power of a body on the scene)

    OpenAIRE

    Rodrigues, Geisa; UFF

    2014-01-01

    RESUMO Este artigo se debruça sobre a análise dos efeitos políticos da configuração do personagem Madame Satã, no filme "Madame Satã" (2002), de Karim Aïnouz. Destaca-se, no caso, uma intimidade que nasce de uma proximidade construída no espaço e no tempo diegéticos e que ao mesmo tempo permite explorar lugares e situações praticamente atemporais e indefinidos: pele, poros, mofo e rachaduras nas paredes, suor, purpurina, tecidos, objetos de cena cotidianos. Desta forma, o corpo de Satã as...

  15. Astrossismologia e o satélite COROT

    Science.gov (United States)

    Andrade, L. B. P.; Janot Pacheco, E.

    2003-08-01

    Este trabalho centra-se em atividades na fase de pré-lançamento do satélite COROT, da agência espacial francesa (CNES), a ser lançado em 2005. O satélite será dedicado à sismologia estelar e à procura de exoplanetas. Nosso programa de trabalho centra-se em dois pontos principais: (1) efetuar uma procura detalhada nos campos COROT de alvos astrofísicos de especial interesse; (2) participar das análises espectroscópicas prévias de alvos selecionados para determinação de parâmetros físicos das estrelas com a maior precisão possível. Na presente etapa, priorizou-se o primeiro ponto do projeto. Foi feito um levantamento geral dos objetos astrofísicos encontrados nos dois campos de observação, centrados em 06H50M e 18H50M, com raios de 10 minutos. Concluiu-se que as estrelas B-Be deverão ser observadas no campo sismológico, enquanto que as anãs brancas deverão sê-lo no campo exoplanetário. Objetos a serem observados foram escolhidos de forma a estarem próximos de alvos principais dos programas centrais do satélite. Paralelamente, estudos e pesquisas bibliográficas foram feitos para compreender os assuntos de interesse principal, ou seja, as pulsações não-radiais de estrelas Ob-Be

  16. Thermal Analysis of Iodine Satellite (iSAT)

    Science.gov (United States)

    Mauro, Stephanie

    2015-01-01

    This paper presents the progress of the thermal analysis and design of the Iodine Satellite (iSAT). The purpose of the iSAT spacecraft (SC) is to demonstrate the ability of the iodine Hall Thruster propulsion system throughout a one year mission in an effort to mature the system for use on future satellites. The benefit of this propulsion system is that it uses a propellant, iodine, that is easy to store and provides a high thrust-to-mass ratio. The spacecraft will also act as a bus for an earth observation payload, the Long Wave Infrared (LWIR) Camera. Four phases of the mission, determined to either be critical to achieving requirements or phases of thermal concern, are modeled. The phases are the Right Ascension of the Ascending Node (RAAN) Change, Altitude Reduction, De-Orbit, and Science Phases. Each phase was modeled in a worst case hot environment and the coldest phase, the Science Phase, was also modeled in a worst case cold environment. The thermal environments of the spacecraft are especially important to model because iSAT has a very high power density. The satellite is the size of a 12 unit cubesat, and dissipates slightly more than 75 Watts of power as heat at times. The maximum temperatures for several components are above their maximum operational limit for one or more cases. The analysis done for the first Design and Analysis Cycle (DAC1) showed that many components were above or within 5 degrees Centigrade of their maximum operation limit. The battery is a component of concern because although it is not over its operational temperature limit, efficiency greatly decreases if it operates at the currently predicted temperatures. In the second Design and Analysis Cycle (DAC2), many steps were taken to mitigate the overheating of components, including isolating several high temperature components, removal of components, and rearrangement of systems. These changes have greatly increased the thermal margin available.

  17. FADS: A demonstrator for MilComSat AOCS

    Science.gov (United States)

    Huddleston, Martin; Cope, Paul

    1995-03-01

    This project covers the attitude and orbit control systems (AOCS) research program being carried out as part of the MOD applied research program for AD CIS(OR)1. The project program is to evaluate the candidate sensor technologies and control algorithms, such as Kalman filters, which may be applied to future UK military ComSats. The specific needs of military satellites for robust and threat-resistant control are not offered by current civil technologies which normally use vulnerable earth sensors or RF pointing which is vulnerable to deception. The program is also to investigate ways of reducing control system complexity and improvements in attitude control precision by enabling structural modes to be controlled. The project examines the most promising attitude control system technologies required to support such future communications payloads. User requirements indicate a need for improved threat resistance and for narrower spot beams, and the program supports this perceived need by the use of improved sensors and control algorithms. Improved pointing on civil ComSats is normally by means of ground RF measurements to form a closed loop control system with the spacecraft. For threat reasons this method is unsuitable for military ComSats, and on-board sensors are therefore used. The use of Silicon array star or earth sensors are the most promising, and the sensor program is to concentrate on these. Limited development and available civil sensors will be considered. Experimental work is based on demonstrating and evaluating real hardware in-the-loop on an existing air bearing experimental rig. This offers the closest simulation of real flight performance that can be obtained. The program will develop the Filtered Attitude Determination System (FADS)rig to be fully representative of a MilSatCom satellite, threat-resistant AOCS solution, employing Silicon array star and earth sensors. Both the BAe Mosaic Earth Sensor (MES) nad Marconi Versatile Star Sensor (VSS

  18. Launch and Early Orbit Operations for CryoSat-2

    Science.gov (United States)

    Mardel, Nic; Marchese, Franco

    2010-12-01

    CryoSat-2 was launched from Baikonur on 8th of April 2010 aboard a modified Dnepr ICBM, the so-called SS18 Satan. Following the ascent and separation from the launch vehicle the Flight Operations Segment (FOS) in ESOC, Darmstadt started the operations to configure the satellite into the correct mode to acquire science; switching on units, configuring software and ensuring that the satellite health and performance was as expected. This paper will describe the operations performed by the FOS during the first weeks in orbit, including the unexpected problems encountered, their implications and solutions.

  19. Assessment of Lead Discrimination from CryoSat-2

    DEFF Research Database (Denmark)

    Kildegaard Rose, Stine; Connor, L. N.; Newman, T.

    to spatial and temporal variability. The measurements of sea ice freeboard may be used to estimate sea ice thickness, when combined with examination of leads between ice floes to determine the local sea surface height. With CryoSat-2 (CS), we have the opportunity to measure much more of the Arctic Ocean due...... Topographic Mapper (ATM) laser altimeter data gathered on April 2, 2012, where the NASA P-3 completed an underflight of CS orbit number 10520, north of Alert, Nunavut, Canada. We present a new lead detecting algorithm which was developed using the CS Level1b (L1b) waveforms, and we analyze its capabilities...

  20. SAT Piura: la realidad y la fantasía

    OpenAIRE

    Sánchez Ruíz, Eduardo Alonso

    2014-01-01

    Como todos los años, en enero, los piuranos recibimos la notificación del Servicio de Administración Tributaria Piura y se difunden otros avisos exhortándonos a pagar nuestros impuestos prediales y arbitrios municipales, puntualmente. Este año, específicamente, el SAT Piura envió, en primera instancia, una carta en la que se indicaba que ya se había generado la determinación del importe de nuestros tributos 2014. En esa comunicación, nos invitaba también a pagar puntualmente para recibir cier...

  1. Multi-sensor Observations of the SpinSat Satellite

    Science.gov (United States)

    2015-10-18

    rate, the sphere’s exterior features a reflectance pattern much like that of a beach- ball , a distributed sequence of retro-reflectors, as well as an...been delivered by a SpaceX Dragon supply ship. The launch and deployment of SpinSat were supported by the DoD Space Test program. Figure 1 shows a...reflectance pattern much like that of a beach- ball , a distributed sequence of retro-reflectors, as well as a set of eight light- emitting diodes (LEDs

  2. The Corporation and the Campus; Corporate Support of Higher Education in the 1970's. Proceedings of the Academy of Political Science, Volume XXX, Number 1.

    Science.gov (United States)

    Connery, Robert H., Ed.

    The purpose of the conference was to bring together educational leaders, corporation executives, and spokesmen for minority groups to examine problems in higher education. The papers include: "The Urban Crisis," by Robert C. Wood, and Harriet A. Zuckerman; "Minority Groups," by Charles V. Hamilton; "The Community and the Campus," by Franklin H.…

  3. Public Policy and the Financing of Higher Education in New York. Hofstra University Yearbook of Business, Series 15, Volume 6, 1980.

    Science.gov (United States)

    McKeough, William, Ed.

    Financing of higher education in New York and the public policies which impinge on, influence, and are reflected in the process are explored in this preliminary probe. Chapters include: The Need for the Study (N. J. King); Implications of Tax Policy (Mark Segal); Institutional Tax Exemptions and Tax Benefits (Steven A. Cohen); State Institutional…

  4. AIRS-AMSU variables-CloudSat cloud mask, radar reflectivities, and cloud classification matchups V3.2

    Data.gov (United States)

    National Aeronautics and Space Administration — This is AIRS-CloudSat collocated subset, in NetCDF 4 format. These data contain collocated: AIRS/AMSU retrievals at AMSU footprints, CloudSat radar reflectivities,...

  5. On Further Examination of "On Further Examination." Quick Reference: Testing/SAT.

    Science.gov (United States)

    National Education Association, Washington, DC.

    Discussions of any test must focus on reliability, content validity, and interpretation of results. In this critique of On Further Examination--the report of the Advisory Panel on the Scholastic Aptitude Test (SAT) Score Decline--the National Education Association (NEA) finds no fault with the reliability of the SAT. Its content validity, however,…

  6. On the Factorial Structure of the SAT and Implications for Next-Generation College Readiness Assessments

    Science.gov (United States)

    Wiley, Edward W.; Shavelson, Richard J.; Kurpius, Amy A.

    2014-01-01

    The name "SAT" has become synonymous with college admissions testing; it has been dubbed "the gold standard." Numerous studies on its reliability and predictive validity show that the SAT predicts college performance beyond high school grade point average. Surprisingly, studies of the factorial structure of the current version…

  7. CryoSat2 Pre-Launch Validation Measurements on Arctic Sea Ice

    DEFF Research Database (Denmark)

    Nicolaus, Marcel; Hendricks, Stefan; Stenseng, Lars

    2010-01-01

    One of the main goals of ESA’s CryoSat-2 mission are estimates of the sea-ice mass and mass balance. For this aim, CryoSat-2 is designed to retrieve high-quality thickness data for over sea ice through its onboard radar altimeter. Together with other satellite data products, these thickness data...

  8. The SAT--What Does It Measure and Does It Still Work?

    Science.gov (United States)

    Comras, Jay

    1984-01-01

    Provides a general description of the aims of the Scholastic Aptitude Test (SAT) and focuses on the reasons for the recent declines in verbal and math scores. Also notes the best sorts of preparation--both general academic and specific preparation--for achieving high SAT scores. (JW)

  9. Survey on the implementation and reliability of CubeSat electrical bus interfaces

    NARCIS (Netherlands)

    Bouwmeester, J.; Langer, M; Gill, E.K.A.

    2016-01-01

    This paper provides results and conclusions on a survey on the implementation and reliability aspects of CubeSat bus interfaces, with an emphasis on the data bus and power distribution. It provides recommendations for a future CubeSat bus standard. The survey is based on a literature study and a

  10. Adapting the Survey of Attitudes towards Statistics (SATS-36) for Estonian Secondary School Students

    Science.gov (United States)

    Hommik, Carita; Luik, Piret

    2017-01-01

    The purpose of this study is to adapt the Survey of Attitudes Towards Statistics (SATS-36) for Estonian secondary school students in order to develop a valid instrument to measure students' attitudes within the Estonian educational context. The SATS-36 was administered to Estonian-speaking secondary school students before their compulsory…

  11. PowerCube: Integrated Power, Propulsion, and Pointing for CubeSats Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The PowerCube is a 1U CubeSat module that provides integrated propulsion, power, and precision pointing to enable the low-cost CubeSat platform to be used to conduct...

  12. FA-SAT Is an Old Satellite DNA Frozen in Several Bilateria Genomes

    Science.gov (United States)

    Ferreira, Daniela; Mendes-da-Silva, Ana; Meles, Susana; Adega, Filomena

    2017-01-01

    Abstract In recent years, a growing body of evidence has recognized the tandem repeat sequences, and specifically satellite DNA, as a functional class of sequences in the genomic “dark matter.” Using an original, complementary, and thus an eclectic experimental design, we show that the cat archetypal satellite DNA sequence, FA-SAT, is “frozen” conservatively in several Bilateria genomes. We found different genomic FA-SAT architectures, and the interspersion pattern was conserved. In Carnivora genomes, the FA-SAT-related sequences are also amplified, with the predominance of a specific FA-SAT variant, at the heterochromatic regions. We inspected the cat genome project to locate FA-SAT array flanking regions and revealed an intensive intermingling with transposable elements. Our results also show that FA-SAT-related sequences are transcribed and that the most abundant FA-SAT variant is not always the most transcribed. We thus conclude that the DNA sequences of FA-SAT and their transcripts are “frozen” in these genomes. Future work is needed to disclose any putative function that these sequences may play in these genomes.

  13. On the Combinatorics of SAT and the Complexity of Planar Problems

    DEFF Research Database (Denmark)

    Talebanfard, Navid

    In this thesis we study several problems arising in Boolean satisfiability ranging from lower bounds for SAT algorithms and proof systems to extremal properties of formulas. The first problem is about construction of hard instances for k-SAT algorithms. For PPSZ algorithm [40] we give the first...

  14. Non-"g" Residuals of the SAT and ACT Predict Specific Abilities

    Science.gov (United States)

    Coyle, Thomas R.; Purcell, Jason M.; Snyder, Anissa C.; Kochunov, Peter

    2013-01-01

    This research examined whether non-"g" residuals of the SAT and ACT subtests, obtained after removing g, predicted specific abilities. Non-"g" residuals of the verbal and math subtests of the SAT and ACT were correlated with academic (verbal and math) and non-academic abilities (speed and shop), both based on the Armed Services…

  15. Repugnant Is to Aversion: A Look at ETX and the New SAT I.

    Science.gov (United States)

    Smith, Michael K.

    1994-01-01

    Although recent educational reforms have called for different types of assessments with more relaxed time requirements, the revised Scholastic Assessment Test (SAT) allows less than one minute per verbal and math problem. According to an SAT tutor who took the new exam along with his students, the new test is unnecessarily tricky and should…

  16. Does Quantity Equal Quality?: The Relationship between Length of Response and Scores on the SAT Essay

    Science.gov (United States)

    Kobrin, Jennifer L.; Deng, Hui; Shaw, Emily J.

    2007-01-01

    This study was designed to address two frequent criticisms of the SAT essay--that essay length is the best predictor of scores, and that there is an advantage in using more "sophisticated" examples as opposed to personal experience. The study was based on 2,820 essays from the first three administrations of the new SAT. Each essay was…

  17. Combining Envisat and CryoSat-2 altimetry to inform hydrodynamic models

    DEFF Research Database (Denmark)

    Schneider, Raphael; Nygaard Godiksen, Peter; Ridler, Marc-Etienne

    , or synthetic wide-swath altimetry data as expected from the SWOT mission. This study is one of the first hydrologic applications of altimetry data from a drifting orbit satellite mission, namely CryoSat-2. CryoSat-2 is equipped with the SIRAL instrument, a new type of radar altimeter similar to SRAL...

  18. From thin-air to flat-sat in 12 months: The Twentesat student project

    NARCIS (Netherlands)

    van Langen, Sven Kevin; Bentum, Marinus Jan; de Vries, Rowan; Grootjans, Robert; Grootjans, Roelof; Brethouwer, Martijn F.

    2014-01-01

    TwenteSat aims to build a twin-satellite interferometer in space, a research satellite system in preparation of the OLFAR project. The project will be completely done by students that work on a voluntary basis. The target is to have a flat-sat of at least one of the satellites ready in a short

  19. Exact Ramsey Theory: Green-Tao numbers and SAT

    CERN Document Server

    Kullmann, Oliver

    2010-01-01

    We consider the links between Ramsey theory in the integers, based on van der Waerden's theorem, and (boolean, CNF) SAT solving. We aim at using the problems from exact Ramsey theory, concerned with computing Ramsey-type numbers, as a rich source of test problems, where especially methods for solving hard problems can be developed. In order to control the growth of the problem instances, we introduce "transversal extensions" as a natural way of constructing mixed parameter tuples (k_1, ..., k_m) for van-der-Waerden-like numbers N(k_1, ..., k_m), such that the growth of these numbers is guaranteed to be linear. Based on Green-Tao's theorem we introduce the "Green-Tao numbers" grt(k_1, ..., k_m), which in a sense combine the strict structure of van der Waerden problems with the (pseudo-)randomness of the distribution of prime numbers. Using standard SAT solvers (look-ahead, conflict-driven, and local search) we determine the basic values. It turns out that already for this single form of Ramsey-type problems, w...

  20. Validation of cryoSat-2 based lake levels

    DEFF Research Database (Denmark)

    Nielsen, Karina; Stenseng, Lars; Andersen, Ole Baltazar

    In this study, which is part of the FP7 project Land and Ocean take up from Sentinel-3 (LOTUS), we demonstrate the potential SAR altimetry. We consider lakes at various sizes and evaluate the CryoSat-2 derived lake levels in terms of along-track precision and agreement with in-situ data. As a ref......In this study, which is part of the FP7 project Land and Ocean take up from Sentinel-3 (LOTUS), we demonstrate the potential SAR altimetry. We consider lakes at various sizes and evaluate the CryoSat-2 derived lake levels in terms of along-track precision and agreement with in-situ data....... To derive lake level time series we apply a state-space model with a robust handling of erroneous data. Instead of attempting to identify and remove the polluted observations we use a mixture distribution to describe the observation noise, which prevents the polluted observations from biasing our final...

  1. Report: antibiotic production by thermophilic Bacillus specie SAT-4.

    Science.gov (United States)

    Muhammad, Syed Aun; Ahmad, Safia; Hameed, Abdul

    2009-07-01

    Production of antimicrobial compounds seems to be a general phenomenon for most bacteria. The prevalence of antimicrobial resistance among key microbial pathogens is increasing at an alarming rate worldwide. Current solutions involve development of a more rationale approach to antibiotic use and discover of new antimicrobials. Bacillus species produce a large number of biological compounds active against bacteria, fungi, protozoa and viruses. The process of production usually involves screening of wide range of microorganisms, testing and modification. Production is carried out using fermentation. Thermophilic spore-forming, gram positive, motile rod bacterial strains were isolated from the Thar Desserts, Sindh Province, Pakistan. These strains were screened and checked for antibacterial activity. The best activity was observed by SAT4 against Micrococcus luteus, Staphylococcus aureus and Pseudomonas aeroginosa. The activity was only observed against gram positive bacteria and no activity was seen against Pseudomonas aeroginosa. Thermophilic Bacillus specie SAT4 was found to be active in the fermentation process to produce the antimicrobial agents. Further optimizations of different conditions (time of incubation, media, pH, glucose concentrations, nitrogen concentrations, and temperature) for antimicrobial production by the selected bacterial strain was performed. Agar diffusion assay was performed to evaluate the antibacterial activity. Optimum conditions for the production of antimicrobials by selected isolate were observed to be 48 hour, pH 5, temperature 55 degrees C, 2% glucose and 1.5% nitrogen concentration. This newly isolated bacterial strain has great potential for antimicrobial production at industrial scale.

  2. Biological system development for GraviSat: A new platform for studying photosynthesis and microalgae in space

    Science.gov (United States)

    Fleming, Erich D.; Bebout, Brad M.; Tan, Ming X.; Selch, Florian; Ricco, Antonio J.

    2014-10-01

    microwells that did not include dissolved bicarbonate due to CO2 starvation. Additionally, oxygen production by some microalgae resulted in bubble formation within the wells, which interfered with sensor measurements. Our research achieved prolonged growth periods (>10 months) without excess oxygen production using two microalgal strains, Chlorella vulgaris UTEX 29 and Dunaliella bardawil 30 861, by lowering light intensities (2-10 μmol photons m-2 s-1) and temperature (4-12 °C). Although the experiments described here were performed to develop the GraviSat platform, the results of this study should be useful for the incorporation of microalgae in other satellite payloads with low-volume microfluidic systems.

  3. SAT1, a glutamine transporter, is preferentially expressed in GABAergic neurons

    Directory of Open Access Journals (Sweden)

    Tom Tallak Solbu

    2010-02-01

    Full Text Available Subsets of GABAergic neurons are able to maintain high frequency discharge patterns, which requires efficient replenishment of the releasable pool of GABA. Although glutamine is considered a preferred precursor of GABA, the identity of transporters involved in glutamine uptake by GABAergic neurons remains elusive. Molecular analyses revealed that SAT1 (Slc38a1 features system A characteristics with a preferential affinity for glutamine, and that SAT1 mRNA expression is associated with GABAergic neurons. By generating specific antibodies against SAT1 we show that this glutamine carrier is particularly enriched in GABAergic neurons. Cellular SAT1 distribution resembles that of GAD67, an essential GABA synthesis enzyme, suggesting that SAT1 can be involved in translocating glutamine into GABAergic neurons to facilitate inhibitory neurotransmitter generation.

  4. SAT1, A Glutamine Transporter, is Preferentially Expressed in GABAergic Neurons

    Science.gov (United States)

    Solbu, Tom Tallak; Bjørkmo, Mona; Berghuis, Paul; Harkany, Tibor; Chaudhry, Farrukh A.

    2009-01-01

    Subsets of GABAergic neurons are able to maintain high frequency discharge patterns, which requires efficient replenishment of the releasable pool of GABA. Although glutamine is considered a preferred precursor of GABA, the identity of transporters involved in glutamine uptake by GABAergic neurons remains elusive. Molecular analyses revealed that SAT1 (Slc38a1) features system A characteristics with a preferential affinity for glutamine, and that SAT1 mRNA expression is associated with GABAergic neurons. By generating specific antibodies against SAT1 we show that this glutamine carrier is particularly enriched in GABAergic neurons. Cellular SAT1 distribution resembles that of GAD67, an essential GABA synthesis enzyme, suggesting that SAT1 can be involved in translocating glutamine into GABAergic neurons to facilitate inhibitory neurotransmitter generation. PMID:20161990

  5. A hybrid bit-encoding for SAT planning based on clique-partitioning

    Science.gov (United States)

    Tapia, Cristóbal; San Segundo, Pablo; Galán, Ramón

    2017-09-01

    Planning as satisfiability is one of the most efficient ways to solve classic automated planning problems. In SAT planning, the encoding used to convert the problem to a SAT formula is critical for the performance of the SAT solver. This paper presents a novel bit-encoding that reduces the number of bits required to represent actions in a SAT-based automated planning problem. To obtain such encoding we first build a conflict graph, which represents incompatibilities of pairs of actions, and bitwise encode the subsets of actions determined by a clique partition. This reduces the number of Boolean variables and clauses of the SAT encoding, while preserving the possibility of parallel execution of compatible (non-neighbor) actions. The article also describes an appropriate algorithm for selecting the clique partition for this application and compares the new encodings obtained over some standard planning problems.

  6. From Higher Education to Employment. Volume III: Finland, France, Italy, Japan, Netherlands, Norway = De l'enseignement superieur a l'emploi. Volume III: Finlande, France, Italie, Japan, Norrege, Pays-Bas.

    Science.gov (United States)

    Organisation for Economic Cooperation and Development, Paris (France).

    This document presents statistical data from the countries of France, Finland, the Netherlands, Japan, Italy, and Norway regarding the flows of graduates from higher education and their entry into the workforce. Among the statistical data presented are the trends and current situation in each country for such areas as college enrollments and…

  7. The CloudSat Education Network: Significant Collaborative Research Between Students and Scientists

    Science.gov (United States)

    Rogers, M. A.; Vane, D.

    2009-12-01

    The CloudSat Education Network (CEN) is the primary education and public outreach component of the CloudSat mission. Approximately 116 schools in 16 countries around the world participate in the CEN, and are recruited from schools in the GLOBE program. Students and teachers in the CEN make atmospheric observations of temperature, precipitation, and crucially, of cloud type and cloud cover amount (including photographs of cloud observations), using a modified GLOBE Atmosphere protocol as a guide for observations. CEN observations are taken coincident with CloudSat overpasses, providing coincident spaceborne- and student surface observations. This puts students and teachers participating in the CEN at the forefront of scientific research as directly contributing partners in a collaborative research endeavor. CEN participants make extensive use of the CloudSat/CEN webpage, which is the primary data entry portal for the CEN. Data collected from CEN students is analyzed by CloudSat scientists for quality control purposes, as well as for use in CloudSat-related research. The webpage also provides students with CloudSat overpass dates and times, as well as CEN-specific updates, and articles about CEN projects distributed through a quarterly newsletter. Besides the newsletter, active CEN schools receive periodic visits from CloudSat scientists, providing an opportunity for students and teachers to interact directly with the scientific community. Results from completed student research include an investigation of the effect of different amounts of cloud cover on locally-grown mushroom crops in Thailand, while CloudSat-directed research using student data includes an analysis of the CloudSat cloud classification algorithm using student-collected data as a ground-truth dataset. The results of this latter study are in the process of publication with participating students and teachers listed as co-authors.

  8. Propulsion System and Orbit Maneuver Integration in CubeSats: Trajectory Control Strategies Using Micro Ion Propulsion

    Science.gov (United States)

    Hudson, Jennifer; Martinez, Andres; Petro, Andrew

    2015-01-01

    The Propulsion System and Orbit Maneuver Integration in CubeSats project aims to solve the challenges of integrating a micro electric propulsion system on a CubeSat in order to perform orbital maneuvers and control attitude. This represents a fundamentally new capability for CubeSats, which typically do not contain propulsion systems and cannot maneuver far beyond their initial orbits.

  9. Initial assessment of CryoSat-2 Performance.

    Science.gov (United States)

    Wingham, D.; Galin, N.; Ridout, A.; Cullen, R.; Giles, K. A.; Laxon, S. W.

    2011-12-01

    Following the launch of CryoSat-2 in April 2010, we have examined the performance of the CryoSat-2 SAR Interferometer over the continental ice sheets of Antarctica and Greenland, the Artic Ocean, and, for the purposes of calibration, over the oceans. Our aim has been to provide confirmation of the engineering performance of the radar interferometer, and to provide an initial geophysical validation of the resulting elevation measurements. We have confirmed the engineering performance at system level of the interferometer through performing a sequence of satellite rolls over the oceans, which provide a surface of known behavior and surface gradient. The activity has identified some errors in the SARIN L1b data products presently issued by ESA. Once corrected, the ocean calibration has demonstrated that the interferometer measures across-track surface slopes with a precision of 25 micro-radians and an accuracy of 10 micro-radians, which may be compared with a pre-launch estimation of 100 micro-radians; in short, the engineering performance greatly its the specification. The elevation measurement over the ice sheets combines the interferometer measurement of across track slope with the range measurement deduced from the SAR echoes. We have examined the performance of the range estimation, and determined the range precision to be 19 cm RMS at 20 Hz. We have examined the retrieval of the phase information over the ice sheets, and found the phase estimates to be robust and little affected by the uncertain ice sheet topography. Based on the calibration of the interferometer, the contribution of the across track slope error is, at 0.4 mm, negligible. While the quantity of data available to us that contains the corrections identified by the interferometer is limited, we have been able to confirm the range precision values from a limited cross-over analysis. Over marine sea ice, we have verified the discrimination of sea ice and ocean lead returns using contemporaneous SAR

  10. Lunar and Lagrangian Point L1 L2 CubeSat Communication and Navigation Considerations

    Science.gov (United States)

    Schaire, Scott; Wong, Yen F.; Altunc, Serhat; Bussey, George; Shelton, Marta; Folta, Dave; Gramling, Cheryl; Celeste, Peter; Anderson, Mile; Perrotto, Trish; hide

    2017-01-01

    CubeSats have grown in sophistication to the point that relatively low-cost mission solutions could be undertaken for planetary exploration. There are unique considerations for lunar and L1/L2 CubeSat communication and navigation compared with low earth orbit CubeSats. This paper explores those considerations as they relate to the Lunar IceCube Mission. The Lunar IceCube is a CubeSat mission led by Morehead State University with participation from NASA Goddard Space Flight Center, Jet Propulsion Laboratory, the Busek Company and Vermont Tech. It will search for surface water ice and other resources from a high inclination lunar orbit. Lunar IceCube is one of a select group of CubeSats designed to explore beyond low-earth orbit that will fly on NASA’s Space Launch System (SLS) as secondary payloads for Exploration Mission (EM) 1. Lunar IceCube and the EM-1 CubeSats will lay the groundwork for future lunar and L1/L2 CubeSat missions. This paper discusses communication and navigation needs for the Lunar IceCube mission and navigation and radiation tolerance requirements related to lunar and L1/L2 orbits. Potential CubeSat radios and antennas for such missions are investigated and compared. Ground station coverage, link analysis, and ground station solutions are also discussed. This paper will describe modifications in process for the Morehead ground station, as well as further enhancements of the Morehead ground station and NASA Near Earth Network (NEN) that are being considered. The potential NEN enhancements include upgrading current NEN Cortex receiver with Forward Error Correction (FEC) Turbo Code, providing X-band uplink capability, and adding ranging options. The benefits of ground station enhancements for CubeSats flown on NASA Exploration Missions (EM) are presented. This paper also describes how the NEN may support lunar and L1/L2 CubeSats without any enhancements. In addition, NEN is studying other initiatives to better support the CubeSat community

  11. Bounds on Threshold of Regular Random $k$-SAT

    CERN Document Server

    Rathi, Vishwambhar; Rasmussen, Lars; Skoglund, Mikael

    2010-01-01

    We consider the regular model of formula generation in conjunctive normal form (CNF) introduced by Boufkhad et. al. We derive an upper bound on the satisfiability threshold and NAE-satisfiability threshold for regular random $k$-SAT for any $k \\geq 3$. We show that these bounds matches with the corresponding bound for the uniform model of formula generation. We derive lower bound on the threshold by applying the second moment method to the number of satisfying assignments. For large $k$, we note that the obtained lower bounds on the threshold of a regular random formula converges to the lower bound obtained for the uniform model. Thus, we answer the question posed in \\cite{AcM06} regarding the performance of the second moment method for regular random formulas.

  12. Survey on the implementation and reliability of CubeSat electrical bus interfaces

    Science.gov (United States)

    Bouwmeester, Jasper; Langer, Martin; Gill, Eberhard

    2017-06-01

    This paper provides results and conclusions on a survey on the implementation and reliability aspects of CubeSat bus interfaces, with an emphasis on the data bus and power distribution. It provides recommendations for a future CubeSat bus standard. The survey is based on a literature study and a questionnaire representing 60 launched CubeSats and 44 to be launched CubeSats. It is found that the bus interfaces are not the main driver for mission failures. However, it is concluded that the Inter Integrated Circuit (I2C) data bus, as implemented in a great majority of the CubeSats, caused some catastrophic satellite failures and a vast amount of bus lockups. The power distribution may lead to catastrophic failures if the power lines are not protected against overcurrent. A connector and wiring standard widely implemented in CubeSats is based on the PC/104 standard. Most participants find the 104 pin connector of this standard too large. For a future CubeSat bus interface standard, it is recommended to implement a reliable data bus, a power distribution with overcurrent protection and a wiring harness with smaller connectors compared with PC/104.

  13. SAT, a flexible and optimized Web application for SSR marker development

    Directory of Open Access Journals (Sweden)

    Rami Jean-François

    2007-11-01

    Full Text Available Abstract Background Simple Sequence Repeats (SSRs, or microsatellites, are among the most powerful genetic markers known. A common method for the development of SSR markers is the construction of genomic DNA libraries enriched for SSR sequences, followed by DNA sequencing. However, designing optimal SSR markers from bulk sequence data is a laborious and time-consuming process. Results SAT (SSR Analysis Tool is a user-friendly Web application developed to minimize tedious manual operations and reduce errors. This tool facilitates the integration, analysis and display of sequence data from SSR-enriched libraries. SAT is designed to successively perform base calling and quality evaluation of chromatograms, eliminate cloning vector, adaptors and low quality sequences, detect chimera or partially digested sequences, search for SSR motifs, cluster and assemble the redundant sequences, and design SSR primer pairs. An additional virtual PCR step establishes primer specificity. Users may modify the different parameters of each step of the SAT analysis. Although certain steps are compulsory, such as SSR motifs search and sequence assembly, users do not have to run the entire pipeline, and they can choose selectively which steps to perform. A database allows users to store and query results, and to redo individual steps of the workflow. Conclusion The SAT Web application is available at http://sat.cirad.fr/sat, and a standalone command-line version is also freely downloadable. Users must send an email to the SAT administrator tropgene@cirad.fr to request a login and password.

  14. SAT, a flexible and optimized Web application for SSR marker development.

    Science.gov (United States)

    Dereeper, Alexis; Argout, Xavier; Billot, Claire; Rami, Jean-François; Ruiz, Manuel

    2007-11-29

    Simple Sequence Repeats (SSRs), or microsatellites, are among the most powerful genetic markers known. A common method for the development of SSR markers is the construction of genomic DNA libraries enriched for SSR sequences, followed by DNA sequencing. However, designing optimal SSR markers from bulk sequence data is a laborious and time-consuming process. SAT (SSR Analysis Tool) is a user-friendly Web application developed to minimize tedious manual operations and reduce errors. This tool facilitates the integration, analysis and display of sequence data from SSR-enriched libraries.SAT is designed to successively perform base calling and quality evaluation of chromatograms, eliminate cloning vector, adaptors and low quality sequences, detect chimera or partially digested sequences, search for SSR motifs, cluster and assemble the redundant sequences, and design SSR primer pairs. An additional virtual PCR step establishes primer specificity. Users may modify the different parameters of each step of the SAT analysis. Although certain steps are compulsory, such as SSR motifs search and sequence assembly, users do not have to run the entire pipeline, and they can choose selectively which steps to perform. A database allows users to store and query results, and to redo individual steps of the workflow. The SAT Web application is available at http://sat.cirad.fr/sat, and a standalone command-line version is also freely downloadable. Users must send an email to the SAT administrator tropgene@cirad.fr to request a login and password.

  15. Pi-Sat: A Low Cost Small Satellite and Distributed Spacecraft Mission System Test Platform

    Science.gov (United States)

    Cudmore, Alan

    2015-01-01

    Current technology and budget trends indicate a shift in satellite architectures from large, expensive single satellite missions, to small, low cost distributed spacecraft missions. At the center of this shift is the SmallSatCubesat architecture. The primary goal of the Pi-Sat project is to create a low cost, and easy to use Distributed Spacecraft Mission (DSM) test bed to facilitate the research and development of next-generation DSM technologies and concepts. This test bed also serves as a realistic software development platform for Small Satellite and Cubesat architectures. The Pi-Sat is based on the popular $35 Raspberry Pi single board computer featuring a 700Mhz ARM processor, 512MB of RAM, a flash memory card, and a wealth of IO options. The Raspberry Pi runs the Linux operating system and can easily run Code 582s Core Flight System flight software architecture. The low cost and high availability of the Raspberry Pi make it an ideal platform for a Distributed Spacecraft Mission and Cubesat software development. The Pi-Sat models currently include a Pi-Sat 1U Cube, a Pi-Sat Wireless Node, and a Pi-Sat Cubesat processor card.The Pi-Sat project takes advantage of many popular trends in the Maker community including low cost electronics, 3d printing, and rapid prototyping in order to provide a realistic platform for flight software testing, training, and technology development. The Pi-Sat has also provided fantastic hands on training opportunities for NASA summer interns and Pathways students.

  16. Airborne campaigns for CryoSat pre-launch calibration and validation

    DEFF Research Database (Denmark)

    Hvidegaard, Sine Munk; Forsberg, René; Skourup, Henriette

    2010-01-01

    From 2003 to 2008 DTU Space together with ESA and several international partners carried out airborne and ground field campaigns in preparation for CryoSat validation; called CryoVEx: CryoSat Validation Experiments covering the main ice caps in Greenland, Canada and Svalbard and sea ice...... in the Arctic Ocean. The main goal of the airborne surveys was to acquire coincident scanning laser and CryoSat type radar elevation measurements of the surface; either sea ice or land ice. Selected lines have been surveyed along with detailed mapping of validation sites coordinated with insitu field work...

  17. NASA Near Earth Network (NEN) Support for Lunar and L1/L2 CubeSats

    Science.gov (United States)

    Schaire, Scott; Altunc, Serhat; Wong, Yen; Shelton, Marta; Celeste, Peter; Anderson, Michael; Perrotto, Trish

    2017-01-01

    The NASA Near Earth Network (NEN) consists of globally distributed tracking stations, including NASA, commercial, and partner ground stations, that are strategically located to maximize the coverage provided to a variety of orbital and suborbital missions, including those in LEO, GEO, HEO, lunar and L1/L2 orbits. The NENs future mission set includes and will continue to include CubeSat missions. The majority of the CubeSat missions destined to fly on EM-1, launching in late 2018, many in a lunar orbit, will communicate with ground based stations via X-band and will utilize the NASA Jet Propulsion Laboratory (JPL) developed IRIS radio. The NEN recognizes the important role CubeSats are beginning to play in carrying out NASAs mission and is therefore investigating the modifications needed to provide IRIS radio compatibility. With modification, the NEN could potentially expand support to the EM-1 lunar CubeSats.The NEN could begin providing significant coverage to lunar CubeSat missions utilizing three to four of the NENs mid-latitude sites. This coverage would supplement coverage provided by the JPL Deep Space Network (DSN). The NEN, with smaller apertures than DSN, provides the benefit of a larger beamwidth that could be beneficial in the event of uncertain ephemeris data. In order to realize these benefits the NEN would need to upgrade stations targeted based on coverage ability and current configuration/ease of upgrade, to ensure compatibility with the IRIS radio. In addition, the NEN is working with CubeSat radio developers to ensure NEN compatibility with alternative CubeSat radios for Lunar and L1/L2 CubeSats. The NEN has provided NEN compatibility requirements to several radio developers who are developing radios that offer lower cost and, in some cases, more capabilities with fewer constraints. The NEN is ready to begin supporting CubeSat missions. The NEN is considering network upgrades to broaden the types of CubeSat missions that can be supported and is

  18. On-orbit low gravity cryogenic scientific investigations using the COLD-SAT Satellite

    Science.gov (United States)

    Bailey, W. J.

    1990-01-01

    The Cryogenic On-Orbit Liquid Depot Storage, Acquisition and Transfer (COLD-SAT) Satellite is an experimental spacecraft designed to investigate the systems and technologies required for an efficient, effective, and reliable management of cryogenic fluids in reduced-gravity space environment. This paper defines the technology needs and the accompanying experimental three-month baseline mission of the COLD-SAT Satellite; describes the experiment subsystems, major features, and rationale for satisfying primary and secondary experimental requirements, using LH2 as the test fluid; and presents the conceptual design of the COLD-SAT spacecraft subsystems which support the on-orbit experiment.

  19. Efficient and Reliable Solar Panels for Small CubeSat Picosatellites

    OpenAIRE

    Ivo Vertat; Ales Vobornik

    2014-01-01

    CubeSat picosatellites have a limited area of walls for solar cells assembling and the available area has to be effectively shared with other parts, such as planar antennas, optical sensors, camera lens, and access port. With standard size of solar cell strings, it is not possible to construct a reliable solar panel for CubeSat with redundant strings interconnection. Typical solar panels for CubeSat consist of two solar cell strings serially wired with no redundancy in case of solar string fa...

  20. Cable y satélite: equipamiento del hogar y consumo televisivo

    Directory of Open Access Journals (Sweden)

    Lic. Emilio Fernández Peña

    2000-01-01

    Full Text Available Los servicios de difusión de canales de televisión de pago por satélite (Canal Satélite Digital y Vía Digital y cable son ya una realidad con importante presencia en el sistema televisivo español. Un millón cuatrocientos mil hogares reciben estos servicios con una preponderancia clara de los transmitidos por satélite respecto a los que usan el cable (1,2 millones.

  1. Retracking CryoSat waveforms for near-real-time ocean forecast products, platform attitude, and other applications

    Science.gov (United States)

    Smith, W. H.; Scharroo, R.; Lillibridge, J. L.; Leuliette, E. W.

    2011-12-01

    Jensen (IEEE TGARS 1999 37(2), 651-658) that waveform sampling rates should be doubled prior to forming the summed squared power, since squaring doubles frequency. This will show whether higher resolution is potentially available from conventional altimeters. Two forthcoming altimeter satellites, Sentinel-3 and Jason-CS, will have instrument heritage from CryoSat's SIRAL. Therefore the altimeter community should be interested in these new capabilities that we can test with CryoSat.

  2. PAN AIR - A Computer Program for Predicting Subsonic or Supersonic Linear Potential Flows about Arbitrary Configurations Using a Higher Order Panel Method. Volume I. Theory Document (Version 1.0)

    Science.gov (United States)

    1980-04-15

    i-L LS.0.1.-U u cy 4- wI CLw 10) 4. 0) .1-1 4)0 WO) to to U ECO) (I f QEl) 44 0) e &.. a3) eL0 sLC . .C.= r-C4- CO .41 01 0 C f- 4J4 1 K 441 41 to LL...1/3(oi + 02 + 03) + (3 c(C) - 01 - a2 - 03) (3/9) = 0(c) (1.3.15a) since Li(C) = 1/3 1 = 1,2,3 (I.3.15b) rhus, f(P) sat 4 sfies six of our... sat s+t s2 +t 2 s2+t 2 (J.4.22) Comb’ning these results, we have -d . s-Jds S2 +t 2 (by definition of ") 02 (J.4.23) The integrals in (J.4.1 8 ) are

  3. CubeSat Ambipolar Thruster for LEO and Deep Space Missions Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Aether Industries proposes the development of a novel, primary plasma propulsion system that is well suited for small spacecraft. This technology, called the CubeSat...

  4. CryoSat-2 Sea Ice Freeboard, Thickness, and Snow Depth Quick Look, Version 1

    Data.gov (United States)

    National Aeronautics and Space Administration — The NASA CryoSat-2 Sea Ice Freeboard, Thickness, and Snow Depth Quick Look product is an experimental sea ice thickness data set containing derived geophysical data...

  5. CryoSat-2 Level-4 Sea Ice Elevation, Freeboard, and Thickness V001

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains 30-day averaged Arctic sea ice thickness estimates, with freeboard and ice surface roughness, derived from the ESA CryoSat-2 Synthetic...

  6. Integrated CubeSat ADACS with Reaction Wheels and Star Tracker Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A high performance ADACS (Attitude Determination and Control System) for CubeSats incorporating Miniature Star Trackers is proposed. The proposed program will focus...

  7. PowerCube: Integrated Power, Propulsion, and Pointing for CubeSats Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Tethers Unlimited, Inc. proposes to develop the PowerCube, an integrated power, propulsion, and pointing solution for CubeSats. The PowerCube combines three...

  8. Deep Space CubeSat Prototype Platform Design and Testing Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to develop and test a proof of concept prototype for a standard CubeSat form factor platform, designed for missions to deep space targets, as opposed to...

  9. Modular NanoSat Launcher Design for Lowest Mission Cost Project

    Data.gov (United States)

    National Aeronautics and Space Administration — As minimum cost will be required for a dedicated NanoSat Launch Vehicle, a series and parallel staged, highly modular vehicle architecture is proposed for design...

  10. 1U CubeSat Lasercom Terminal for Deep Space Communication Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In this NASA SBIR-select Phase 1 program Fibertek, Inc., proposes the design, optimization, and analysis of a 1U CubeSat Lasercom Optical Terminal, optimized for...

  11. SAT-1 -1415T/C polymorphism and susceptibility to schizophrenia.

    Science.gov (United States)

    Bermudo-Soriano, Carlos Riaza; Vaquero-Lorenzo, Concepcion; Diaz-Hernandez, Montserrat; Perez-Rodriguez, M Mercedes; Fernandez-Piqueras, Jose; Saiz-Ruiz, Jeronimo; Baca-Garcia, Enrique

    2009-03-17

    Patients suffering from psychosis show increased blood and fibroblast total polyamine levels. Spermidine/spermine N1-acetyltransferase (SSAT-1) and its coding gene (SAT-1) are the main factors regulating polyamine catabolism. The aim of the present study was to examine the association between the SAT-1 -1415T/C single nucleotide polymorphism (SNP) and schizophrenia. A case-control design was used in order to compare the genotypes for the SNP between schizophrenia patients (n=180, 83 females and 97 males), other non-psychotic psychiatric patients (n=413, 256 females and 157 males), and healthy controls (n=251, 101 females and 150 males). No significant differences in the distribution of the genotypes of the SAT-1 -1415T/C SNP were found groups among groups. We failed to demonstrate a significant association between the SAT-1 -1415T/C SNP and schizophrenia, but a mild association between allele C and psychopathology was found in the female group.

  12. Combined LDI/SAT test to evaluate intestinal lactose digestion and mucosa permeability

    NARCIS (Netherlands)

    Koetse, H. A.; Klaassen, D.; van der Molen, A. R. H.; Elzinga, H.; Bijsterveld, K.; Boverhof, R.; Stellaard, F.

    2006-01-01

    Background Intestinal mucosal damage causes impaired digestive capacity and increased mucosal permeability. Quantification of damage can be used to improve treatment options. Currently, the Lactose Digestion Index (LDI) and the Sugar Absorption Test (SAT) are used for evaluation. The investigation

  13. Plug-and-Play Compatibility for CubeSat Attitude Determination and Control Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The development of Plug-and-play Compatibility for CubeSat Attitude Determination and Control Systems (ADACS) is proposed. Existing Maryland Aerospace (MAI) ADACS...

  14. CS2SAT: THE CONTROL SYSTEMS CYBER SECURITY SELF-ASSESSMENT TOOL

    Energy Technology Data Exchange (ETDEWEB)

    Kathleen A. Lee

    2008-01-01

    The Department of Homeland Security National Cyber Security Division has developed the Control System Cyber Security Self-Assessment Tool (CS2SAT) that provides users with a systematic and repeatable approach for assessing the cyber-security posture of their industrial control system networks. The CS2SAT was developed by cyber security experts from Department of Energy National Laboratories and with assistance from the National Institute of Standards and Technology. The CS2SAT is a desktop software tool that guides users through a step-by-step process to collect facility-specific control system information and then makes appropriate recommendations for improving the system’s cyber-security posture. The CS2SAT provides recommendations from a database of industry available cyber-security practices, which have been adapted specifically for application to industry control system networks and components. Each recommendation is linked to a set of actions that can be applied to remediate-specific security vulnerabilities.

  15. WindSat Radio-Frequency Interference Signature and Its Identification Over Land and Ocean

    National Research Council Canada - National Science Library

    Li, L; Gaiser, Peter W; Bettenhausen, Michael H; Johnston, William

    2006-01-01

    Radio-frequency interference (RFI) in the spaceborne multichannel radiometer data of WindSat and the Advanced Microwave Scanning Radiometer EOS is currently being detected using a spectral difference technique...

  16. The achievement gap: Should we rely on SAT scores to tell us anything about it?

    Directory of Open Access Journals (Sweden)

    Dale Whittington

    2004-04-01

    Full Text Available Increasing numbers of students taking the SAT have declined to identify their race/ethnicity. I examined the impact of non-respondents on the validity of reported racial/ethnic differences and year-to-year changes in test performance. Using an analysis reported by Wainer (1988 and SAT data from 1996 to 2003, I confirmed Wainer’s findings that non-respondents prevent accurate estimations of group differences based on SAT data. I then explored the impact of College Board press release information on news reports about the achievement gap. I found frequent reports of racial/ethnic differences in SAT scores and year-to-year changes in scores but negligible consideration of non-respondents. Press releases and media reports should include information about non-respondents and their impact on accuracy of reported differences based on race/ethnicity.

  17. Integrated Propulsion and Primary Structure Module for Small Satellite and CubeSat Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Over the last decade, the CubeSat platform has emerged as a viable alternative for both innovative technology development and scientific investigation. However, to...

  18. A Green, Safe, Dual-pulse Solid Motor for CubeSat Orbit Changing Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Small satellites such as CubeSats are in need of responsive propulsion, but are limited due to their size. Though single pulse, AP/HTPB fueled solid rocket motors...

  19. Coastal Sea Level from CryoSat-2 SARIn Altimetry in Norway

    DEFF Research Database (Denmark)

    Idžanović, Martina; Ophaug, Vegard; Andersen, Ole Baltazar

    2017-01-01

    Conventional (pulse-limited) altimeters determine the sea surface height with an accuracy of a few centimeters over the open ocean. Sea surface heights and tide-gauge sea level serve as each other’s buddy check. However, in coastal areas, altimetry suffers from numerous effects, which degrade its...... conventional altimeters. In this study, we explore the potential of CryoSat-2 to provide valid observations in the Norwegian coastal zone. We do this by comparing time series of CryoSat-2 sea level anomalies with time series of in situ sea level at 22 tide gauges, where the CryoSat-2 sea level anomalies...... are averaged in a 45-km area around each tide gauge. For all tide gauges, CryoSat-2 shows standard deviations of differences and correlations of 16 cm and 61%, respectively. We further identify the ocean tide and inverted barometer geophysical corrections as the most crucial, and note that a large amount...

  20. The GeneSat-1 Microsatellite MissionA Challenge in Small Satellite Design

    OpenAIRE

    Kitts, Christopher; Hines, John; Agasid, Elwood; Ricco, Antonio; Yost, Bruce; Ronzano, Karolyn; Puig-Suari, Jordi

    2006-01-01

    The mission of the GeneSat-1 technology demonstration spacecraft is to validate the use of researchquality instrumentation for in situ biological research and processing. GeneSat-1 is a “triple-CubeSat” vehicle currently being developed for launch as a secondary payload on a Minotaur launch vehicle in late 2006. Spacecraft and mission development is being led by the NASA Ames Research Center Astrobionics group. However, university participation is a crucial element of the program with signifi...

  1. NPS-SCAT; Communications System Design, Test and Integration of NPS’ First CubeSat

    Science.gov (United States)

    2010-09-01

    Arboleda (Columbia) launched their first CubeSats: CSTB-1, MAST, CAPE-2, and Libertad -1. Cal Poly also launched their first and second CubeSats, CP3...All of the satellites except CAPE-2 and Libertad -1 have established communications with the ground and passed data. CAPE-2 had a faulty...transceiver and Libertad -1 had a non-working ground station prior to launch which repairs were not completed in time to communicate with the satellite. The

  2. RECIFE-SAT: A MILP-based algorithm for the railway saturation problem

    OpenAIRE

    PELLEGRINI, Paola; MARLIERE, Grégory; RODRIGUEZ, Joaquin

    2017-01-01

    Measuring capacity of railway infrastructures is a problem even in its definition. In this paper, we propose RECIFE-SAT, a MILP-based algorithm to quantify capacity by solving the saturation problem. This problem consists of saturating an infrastructure by adding as many trains as possible to an existing (possibly empty) timetable. Specifically, RECIFE-SAT considers a large set of potentially interesting saturation trains and integrates them in the timetable whenever possible. This integratio...

  3. SAT1, a glutamine transporter, is preferentially expressed in GABAergic neurons

    OpenAIRE

    Tom Tallak Solbu; Tom Tallak Solbu; Mona Bjørkmo; Mona Bjørkmo; Paul Berghuis; Tibor Harkany; Tibor Harkany; Farrukh A Chaudhry; Farrukh A Chaudhry

    2010-01-01

    Subsets of GABAergic neurons are able to maintain high frequency discharge patterns, which requires efficient replenishment of the releasable pool of GABA. Although glutamine is considered a preferred precursor of GABA, the identity of transporters involved in glutamine uptake by GABAergic neurons remains elusive. Molecular analyses revealed that SAT1 (Slc38a1) features system A characteristics with a preferential affinity for glutamine, and that SAT1 mRNA expression is associated with GABAe...

  4. SAT1, A Glutamine Transporter, is Preferentially Expressed in GABAergic Neurons

    OpenAIRE

    Solbu, Tom Tallak; Bjørkmo, Mona; Berghuis, Paul; Harkany, Tibor; Chaudhry, Farrukh A.

    2010-01-01

    Subsets of GABAergic neurons are able to maintain high frequency discharge patterns, which requires efficient replenishment of the releasable pool of GABA. Although glutamine is considered a preferred precursor of GABA, the identity of transporters involved in glutamine uptake by GABAergic neurons remains elusive. Molecular analyses revealed that SAT1 (Slc38a1) features system A characteristics with a preferential affinity for glutamine, and that SAT1 mRNA expression is associated with GABAer...

  5. Annual cycle in lakes and rivers from CryoSat-2 altimetry — The Brahmaputra river

    DEFF Research Database (Denmark)

    Villadsen, Heidi; Andersen, Ole Baltazar; Stenseng, Lars

    2014-01-01

    A key concern of the CryoSat-2 orbit has been its long repeat period of 369 days, which is usually undesirable for river and lake monitoring. However, the results of this study show that CryoSat-2 data can indeed be used for such monitoring by utilizing the high spatial coverage and the sub......-cycle period of 30 days. The performance of CryoSat-2/SIRAL altimetry for river level monitoring is investigated by studying river levels retrieved from Ganges and Brahmaputra. An evaluation of CryoSat-2 river levels from LRM, SAR and SARIn data is performed by comparing with Envisat data from the period...... in which the two missions overlapped (2010–2012). Time series constructed using simple linear interpolation are fitted with a model to compare the captured annual signals and amplitudes. The annual cycles seen in CryoSat-2 and Envisat altimetry data agree very well and provide confidence in using CryoSat-2...

  6. Foot-and-mouth disease virus serotype SAT1 in cattle, Nigeria.

    Science.gov (United States)

    Ehizibolo, D O; Haegeman, A; De Vleeschauwer, A R; Umoh, J U; Kazeem, H M; Okolocha, E C; Van Borm, S; De Clercq, K

    2017-06-01

    The knowledge of foot-and-mouth disease virus (FMDV) dynamics and epidemiology in Nigeria and the West Africa subregion is important to support local and regional control plans and international risk assessment. Foot-and-mouth disease virus serotype South African territories (SAT)1 was isolated, identified and characterized from an FMD outbreak in cattle in Nigeria in 2015, 35 years after the last report of FMDV SAT1 in West Africa. The VP1 coding sequence of the Nigerian 2015 SAT1 isolates diverges from reported SAT1 topotypes resulting in a separate topotype. The reporting of a novel FMDV SAT1 strain in the virus pool 5 (West and Central Africa) highlights the dynamic and complex nature of FMDV in this region of Africa. Sustained surveillance is needed to understand the origin, the extent and distribution of this novel SAT1 topotype in the region as well as to detect and monitor the occurrence of (re-)emerging FMDV strains. © 2017 Blackwell Verlag GmbH.

  7. Psychometric validation of the overactive bladder satisfaction with treatment questionnaire (OAB-SAT-q).

    Science.gov (United States)

    Margolis, Mary Kay; Fox, Kathleen M; Cerulli, Annamaria; Ariely, Rinat; Kahler, Kristijan H; Coyne, Karin S

    2009-01-01

    Valid and reliable questionnaires must be used to accurately assess patients' satisfaction with overactive bladder (OAB) treatment. This study evaluated the reliability and validity of the OAB Satisfaction with Treatment Questionnaire (OAB-SAT-q). This was a secondary analysis of clinical study data of patients randomized to darifenacin or darifenacin plus Behavioral Modification Program. Patients completed the Overactive Bladder Questionnaire (OAB-q) and a 3-day bladder diary at Baseline and Week 12 and the OAB-SAT-q at Week 12. Internal consistency reliability was assessed by Cronbach's alpha. Concurrent validity was assessed through correlations with OAB-q change scores and adverse events (AEs). Discriminant validity was assessed among subgroups using general linear models. Analyses utilized a per-protocol population (completion of OAB-q at Baseline and OAB-q and OAB-SAT-q at Week 12) (n = 375). Exploratory factor analysis of the OAB-SAT-q revealed three 3-item subscales (Satisfaction, Side Effects, Endorsement) and two single items (Convenience, Preference). Cronbach's alphas = 0.84-0.95. Subscale-to-subscale correlations = 0.10-0.67 (all P 3 episodes (all P SAT-q does not appear to discriminate by incontinence episodes. The OAB-SAT-q demonstrated good psychometric properties in this initial evaluation-including internal consistency reliability and concurrent and discriminant validity-and appears to be a useful assessment of OAB treatment satisfaction. Neurourol. Urodynam. 28:416-422, 2009. (c) 2008 Wiley-Liss, Inc.

  8. Patient satisfaction with hospital rehabilitation: validation of the SAT-16 questionnaire through Rasch analysis.

    Science.gov (United States)

    Ottonello, M; Franchignoni, F; Giordano, A; Benevolo, E

    2012-02-01

    The SAT-16 is a 16-item self-administered questionnaire measuring patient satisfaction with the quality of care during stay in a rehabilitation unit. A comprehensive psychometric analysis of SAT-16 was performed using both classical test theory and Rasch analysis (RA) to examine its validity and metric properties, and provide further insights for its clinical use in rehabilitation settings. A sample of 9458 patients, consecutively admitted to two Rehabilitation Centres, was examined with SAT-16. Factor (both explorative and confirmatory) analysis and RA were used to process the data in order to examine validity and metric properties of SAT-16. Dimensionality, item fit to the model, response category performance and internal construct validity were assessed. Two subscales were identified by factor analysis and expert review, respectively related to satisfaction with clinical care (items 1-9), and satisfaction with hospital organization and facilities ("hotel" aspects of care, items 10-16). Each subscale underwent a separate RA. Response categories were revised in both subscales of SAT-16, obtaining a new 3-level rating scale. Both subscales showed high internal consistency and internal validity. RA confirmed the appropriateness of SAT-16 and its usefulness in identifying areas for quality improvement. Overall, the questionnaire allows to assess patient satisfaction with the services through: 1) two sub-scores respectively specific for satisfaction with "clinical care" and "hotel aspects of care"; 2) additional information gathered in the optional open-ended questions.

  9. Using Additive Manufacturing to Print a CubeSat Propulsion System

    Science.gov (United States)

    Marshall, William M.

    2015-01-01

    CubeSats are increasingly being utilized for missions traditionally ascribed to larger satellites CubeSat unit (1U) defined as 10 cm x 10 cm x 11 cm. Have been built up to 6U sizes. CubeSats are typically built up from commercially available off-the-shelf components, but have limited capabilities. By using additive manufacturing, mission specific capabilities (such as propulsion), can be built into a system. This effort is part of STMD Small Satellite program Printing the Complete CubeSat. Interest in propulsion concepts for CubeSats is rapidly gaining interest-Numerous concepts exist for CubeSat scale propulsion concepts. The focus of this effort is how to incorporate into structure using additive manufacturing. End-use of propulsion system dictates which type of system to develop-Pulse-mode RCS would require different system than a delta-V orbital maneuvering system. Team chose an RCS system based on available propulsion systems and feasibility of printing using a materials extrusion process. Initially investigated a cold-gas propulsion system for RCS applications-Materials extrusion process did not permit adequate sealing of part to make this a functional approach.

  10. In-vitro evaluation of the PediaSat continuous central venous oxygenation monitoring system.

    Science.gov (United States)

    Baulig, Werner; Spielmann, Nelly; Zaiter, Hassan; Lijovic, Tomislav; Bettex, Dominique; Bürki, Christoph; Weiss, Markus

    2010-03-01

    In-vitro performance of the PediaSat system for continuous monitoring of central venous oxygen saturation by spectrophotometry has been evaluated. PediaSat continuous fibre-optic oximetry catheters were inserted in a black testing chamber, connected with an extracorporeal circuit and filled with human whole blood. Oxygen inflow into the cardiopulmonary bypass system was varied, and the testing chamber was perfused with blood flow of 1000 ml min(-1). Oxygen saturation values measured by PediaSat (S PediaSat O2) were compared with cooximetry (S CO-OX O2) values from simultaneously taken blood samples by Bland-Altman and simple regression analyses. Fifty data pairs were obtained. S PediaSat O2 and S CO-OX O2 values ranged between 28-98 and 24.9-99.5%, respectively. Correlation between S PediSat O2 and S CO-OX O2 was high with an r2 value equal to 0.96 (P central venous oxygen saturation.

  11. Lunar CubeSat Impact Trajectory Characteristics as a Function of Its Release Conditions

    Directory of Open Access Journals (Sweden)

    Young-Joo Song

    2015-01-01

    Full Text Available As a part of early system design activities, trajectory characteristics for a lunar CubeSat impactor mission as a function of its release conditions are analyzed. The goal of this mission is to take measurements of surface magnetic fields to study lunar magnetic anomalies. To deploy the CubeSat impactor, a mother-ship is assumed to have a circular polar orbit with inclination of 90 degrees at a 100 km altitude at the Moon. Both the in- and out-of-plane direction deploy angles as well as delta-V magnitudes are considered for the CubeSat release conditions. All necessary parameters required at the early design phase are analyzed, including CubeSat flight time to reach the lunar surface, impact velocity, cross ranges distance, and associated impact angles, which are all directly affected by the CubeSat release conditions. Also, relative motions between these two satellites are analyzed for communication and navigation purposes. Although the current analysis is only focused on a lunar impactor mission, the methods described in this work can easily be modified and applied to any future planetary impactor missions with CubeSat-based payloads.

  12. Higher-order Kerr effect and harmonic cascading in gases

    OpenAIRE

    Bache, Morten; Eilenberger, Falk; Minardi, Stefano

    2012-01-01

    The higher-order Kerr effect (HOKE) has recently been advocated to explain measurements of the saturation of the nonlinear refractive index in gases. Here we show that cascaded third-harmonic generation results in an effective fifth-order nonlinearity that is negative and significant. Higher-order harmonic cascading will also occur from the HOKE, and the cascading contributions may significantly modify the observed nonlinear index change. At lower wavelengths, cascading increases the HOKE sat...

  13. Deciphering Staphylococcus sciuri SAT-17 Mediated Anti-oxidative Defense Mechanisms and Growth Modulations in Salt Stressed Maize (Zea mays L.).

    Science.gov (United States)

    Akram, Muhammad S; Shahid, Muhammad; Tariq, Mohsin; Azeem, Muhammad; Javed, Muhammad T; Saleem, Seemab; Riaz, Saba

    2016-01-01

    Soil salinity severely affects plant nutrient use efficiency and is a worldwide constraint for sustainable crop production. Plant growth-promoting rhizobacteria, with inherent salinity tolerance, are able to enhance plant growth and productivity by inducing modulations in various metabolic pathways. In the present study, we reported the isolation and characterization of a salt-tolerant rhizobacterium from Kallar grass [Leptochloa fusca (L.) Kunth]. Sequencing of the 16S rRNA gene revealed its lineage to Staphylococcus sciuri and it was named as SAT-17. The strain exhibited substantial potential of phosphate solubilization as well as indole-3-acetic acid production (up to 2 M NaCl) and 1-aminocyclopropane-1-carboxylic acid deaminase activity (up to 1.5 M NaCl). Inoculation of a rifampicin-resistant derivative of the SAT-17 with maize, in the absence of salt stress, induced a significant increase in plant biomass together with decreased reactive oxygen species and increased activity of cellular antioxidant enzymes. The derivative strain also significantly accumulated nutrients in roots and shoots, and enhanced chlorophyll and protein contents in comparison with non-inoculated plants. Similar positive effects were observed in the presence of salt stress, although the effect was more prominent at 75 mM in comparison to higher NaCl level (150 mM). The strain survived in the rhizosphere up to 30 days at an optimal population density (ca. 1 × 10(6) CFU mL(-1)). It was concluded that S. sciuri strain SAT-17 alleviated maize plants from salt-induced cellular oxidative damage and enhanced growth. Further field experiments should be conducted, considering SAT-17 as a potential bio-fertilizer, to draw parallels between PGPR inoculation, elemental mobility patterns, crop growth and productivity in salt-stressed semi-arid and arid regions.

  14. Bounded Semantics of CTL and SAT-Based Verification

    Science.gov (United States)

    Zhang, Wenhui

    Bounded model checking has been proposed as a complementary approach to BDD based symbolic model checking for combating the state explosion problem, esp. for efficient error detection. This has led to a lot of successful work with respect to error detection in the checking of LTL, ACTL (the universal fragment of CTL) and ACTL* properties by satisfiability testing. The use of bounded model checking for verification (in contrast to error detection) of LTL and ACTL properties has later also been studied. This paper studies the potentials and limitations of bounded model checking for the verification of CTL and CTL* formulas. On the theoretical side, we first provide a framework for discussion of bounded semantics, which serves as the basis for bounded model checking, then extend the bounded semantics of ACTL to a bounded semantics of CTL, and discuss the limitation of developing such a bounded semantics for CTL*. On the practical side, a deduction of a SAT-based bounded model checking approach for ACTL properties from the bounded semantics of CTL is demonstrated, and a comparison of such an approach with BDD-based model checking is presented based on experimental results.

  15. Semi-supervised classification tool for DubaiSat-2 multispectral imagery

    Science.gov (United States)

    Al-Mansoori, Saeed

    2015-10-01

    This paper addresses a semi-supervised classification tool based on a pixel-based approach of the multi-spectral satellite imagery. There are not many studies demonstrating such algorithm for the multispectral images, especially when the image consists of 4 bands (Red, Green, Blue and Near Infrared) as in DubaiSat-2 satellite images. The proposed approach utilizes both unsupervised and supervised classification schemes sequentially to identify four classes in the image, namely, water bodies, vegetation, land (developed and undeveloped areas) and paved areas (i.e. roads). The unsupervised classification concept is applied to identify two classes; water bodies and vegetation, based on a well-known index that uses the distinct wavelengths of visible and near-infrared sunlight that is absorbed and reflected by the plants to identify the classes; this index parameter is called "Normalized Difference Vegetation Index (NDVI)". Afterward, the supervised classification is performed by selecting training homogenous samples for roads and land areas. Here, a precise selection of training samples plays a vital role in the classification accuracy. Post classification is finally performed to enhance the classification accuracy, where the classified image is sieved, clumped and filtered before producing final output. Overall, the supervised classification approach produced higher accuracy than the unsupervised method. This paper shows some current preliminary research results which point out the effectiveness of the proposed technique in a virtual perspective.

  16. Analysis of two strains of Peanut stunt virus: satRNA-associated and satRNA free.

    Science.gov (United States)

    Obrępalska-Stęplowska, Aleksandra; Budziszewska, Marta; Wieczorek, Przemysław; Czerwoniec, Anna

    2012-06-01

    Peanut stunt virus (PSV) is a pathogen of legumes, vegetables, trees, and weeds occurring worldwide. The species is characterized by significant genetic variability. PSV strains are classified into four subgroups on the basis of their nucleotide sequence homology. Here, we are presenting two further, fully sequenced PSV strains-PSV-Ag and PSV-G, that could be considered as I subgroup representatives. However, their sequence homology with other typical I subgroups members, similarly as another strain-PSV-P, characterized by our group previously, is lower than 90%. This lead us to propose further subdivision of the I subgroup into IA, IB, and IC units, and to classify PSV-Ag and PSV-G strains to the last one. In this article, we are showing that identity level of PSV-Ag and PSV-G is very high and apart from the presence of satRNA in the first one, they differ only by a few nucleotides in their genomic RNAs. Nevertheless, symptoms they cause on host plants might differ significantly, just as the levels in infected plants. Effect of single amino acid changes between strains on the three-dimensional structure of viral proteins was analyzed. Differences occur mainly on the protein surfaces which can possibly affect protein-protein interaction in infected cells, which is discussed.

  17. The liver and kidney expression of sulfate anion transporter sat-1 in rats exhibits male-dominant gender differences

    OpenAIRE

    Brzica, Hrvoje; Breljak, Davorka; Krick, Wolfgang; Lovrić, Mila; Burckhardt, Gerhard; Burckhardt, Birgitta; Sabolić, Ivan

    2008-01-01

    The sulfate anion transporter (sat-1, Slc26a1) has been cloned from rat liver, functionally characterized, and localized to the sinusoidal membrane in hepatocytes and basolateral membrane (BLM) in proximal tubules (PT). Here, we confirm previously described localization of sat-1 protein in rat liver and kidneys and report on gender differences (GD) in its expression by immunochemical, transport, and excretion studies in rats. The ∼85-kDa sat-1 protein was localized to the sinusoidal membrane ...

  18. Tracking Dynamic Northern Surface Water Changes with High-Frequency Planet CubeSat Imagery

    Directory of Open Access Journals (Sweden)

    Sarah W. Cooley

    2017-12-01

    Full Text Available Recent deployments of CubeSat imagers by companies such as Planet may advance hydrological remote sensing by providing an unprecedented combination of high temporal and high spatial resolution imagery at the global scale. With approximately 170 CubeSats orbiting at full operational capacity, the Planet CubeSat constellation currently offers an average revisit time of <1 day for the Arctic and near-daily revisit time globally at 3 m spatial resolution. Such data have numerous potential applications for water resource monitoring, hydrologic modeling and hydrologic research. Here we evaluate Planet CubeSat imaging capabilities and potential scientific utility for surface water studies in the Yukon Flats, a large sub-Arctic wetland in north central Alaska. We find that surface water areas delineated from Planet imagery have a normalized root mean square error (NRMSE of <11% and geolocation accuracy of <10 m as compared with manual delineations from high resolution (0.3–0.5 m WorldView-2/3 panchromatic satellite imagery. For a 625 km2 subarea of the Yukon Flats, our time series analysis reveals that roughly one quarter of 268 lakes analyzed responded to changes in Yukon River discharge over the period 23 June–1 October 2016, one half steadily contracted, and one quarter remained unchanged. The spatial pattern of observed lake changes is heterogeneous. While connections to Yukon River control the hydrologically connected lakes, the behavior of other lakes is complex, likely driven by a combination of intricate flow paths, underlying geology and permafrost. Limitations of Planet CubeSat imagery include a lack of an automated cloud mask, geolocation inaccuracies, and inconsistent radiometric calibration across multiple platforms. Although these challenges must be addressed before Planet CubeSat imagery can achieve its full potential for large-scale hydrologic research, we conclude that CubeSat imagery offers a powerful new tool for the study and

  19. Design for CubeSat-based dust and radiation studies at Europa

    Science.gov (United States)

    Goel, Ashish; Krishnamoorthy, Siddharth; Swenson, Travis; West, Stephen; Li, Alan; Crew, Alexander; Phillips, Derek James; Screve, Antoine; Close, Sigrid

    2017-07-01

    Europa is one of the icy moons of Jupiter and the possibility of an ocean of liquid water beneath its icy crust makes it one of the most fascinating destinations for exploration in the solar system. NASA's Europa Multiple Flyby Mission (EMFM, formerly Europa Clipper) is slated to visit the icy moon in a timeframe near the year 2022 to study the habitability of Europa. CubeSats carried along by the primary mission can supplement the measurements made, at a relatively low cost, and with the added benefits of involving students at universities in this challenging endeavor. Further, such a mission holds the key to extending the applicability of CubeSats to interplanetary missions. In this paper, we present the design of the Europa Radiation and Dust Observation Satellite (ERDOS), a 3U CubeSat designed to be deployed by the Europa Multiple Flyby Mission to carry out measurements of the radiation and dust environment, before impacting Europa's surface. We present a detailed design for a CubeSat-based secondary mission, and discuss the science goals that may be accomplished by such a mission. Further, we discuss results from a comprehensive analysis of various engineering challenges associated with an interplanetary CubeSat mission, such as radiation shielding and thermal environment control. Our results show that a short duration CubeSat-based flyby mission is feasible when the CubeSat is carried on board the primary mission until the Jovian system is reached. Such a flyby mission can provide important supplementary information to the primary mission about Europa's environment at a closer range and lead to a substantial increase in scientific knowledge about surface processes on Europa.

  20. Development and validation of the smart management strategy for health assessment tool-short form (SAT-SF) in cancer survivors.

    Science.gov (United States)

    Yun, Young Ho; Jung, Ju Youn; Sim, Jin Ah; Lee, JongMog; Noh, Dong-Young; Han, Wonshik; Park, Kyu Joo; Jeong, Seung-Yong; Park, Ji Won; Wu, Hong-Gyun; Chie, Eui Kyu; Kim, Hak Jae; Jung, Kyung Hae; Zo, Jae-Ill; Kim, Sung; Lee, Jeong Eon; Nam, Seok Jin; Lee, Eun Sook; Oh, Jae Hwan; Kim, Young-Woo; Kim, Young Tae; Shim, Young Mog

    2017-10-30

    The aim of this study was to develop and validate a short form (SF) of the Smart Management Strategy for Health Assessment Tool (SAT) for cancer patients. Data for item reduction were derived from cancer patient data (n = 300) previously used to develop the original SAT. We used regression methods to select and score the new SAT-SF. To assess the instrument's reliability and validity, we recruited another 354 cancer patients from the same hospitals who were older than 18 years and accustomed to using the web. All results were compared with that of the long-form SAT (original SAT). The SAT-SF used is the shorter version, a 30-item (from the original 91-item) instrument, to measure cancer patient's health. The 30-item SAT-SF explained 97.7% of total variance of the full 91-item long-form SAT. All SAT-SF subscales demonstrated a high reliability with good internal consistency compared with the original SAT. The total short-form scores of the three SAT sets (SAT-Core, SAT-Preparation, SAT-Implementation) differentiated participant groups according to their stage of goal implementation and percentage of actions taken in the 10 Rules for Highly Effective Health Behavior. We found acceptable correlations between the three SAT-SF sets and the additional assessment tools compared with the original SAT. The 30-item SAT-SF had a satisfactory internal consistency and validity for cancer patients with minimal loss of information compared with the original SAT.

  1. Renormalized Volume

    Science.gov (United States)

    Gover, A. Rod; Waldron, Andrew

    2017-09-01

    We develop a universal distributional calculus for regulated volumes of metrics that are suitably singular along hypersurfaces. When the hypersurface is a conformal infinity we give simple integrated distribution expressions for the divergences and anomaly of the regulated volume functional valid for any choice of regulator. For closed hypersurfaces or conformally compact geometries, methods from a previously developed boundary calculus for conformally compact manifolds can be applied to give explicit holographic formulæ for the divergences and anomaly expressed as hypersurface integrals over local quantities (the method also extends to non-closed hypersurfaces). The resulting anomaly does not depend on any particular choice of regulator, while the regulator dependence of the divergences is precisely captured by these formulæ. Conformal hypersurface invariants can be studied by demanding that the singular metric obey, smoothly and formally to a suitable order, a Yamabe type problem with boundary data along the conformal infinity. We prove that the volume anomaly for these singular Yamabe solutions is a conformally invariant integral of a local Q-curvature that generalizes the Branson Q-curvature by including data of the embedding. In each dimension this canonically defines a higher dimensional generalization of the Willmore energy/rigid string action. Recently, Graham proved that the first variation of the volume anomaly recovers the density obstructing smooth solutions to this singular Yamabe problem; we give a new proof of this result employing our boundary calculus. Physical applications of our results include studies of quantum corrections to entanglement entropies.

  2. Higher education

    OpenAIRE

    Wolter, Andrä

    2009-01-01

    During the last five years higher education research in Germany seems to be in a significant upturn. This is a side effect partly of the obvious boom of empirical educational research in general and partly of the reform movement that has affected the German higher education system since middle of the 1990s. The demand for data in the field of higher education will increase considerably in future. The available data infrastructure for higher education research in Germany consists of two comple...

  3. Progress towards a Drag-free SmallSat

    Science.gov (United States)

    Saraf, Shailendhar

    The net force acting on a drag-free satellite is purely gravitational as all other forces, mainly atmospheric drag and solar radiation pressure, are canceled out. In order to achieve this, a free floating reference (test mass) inside the satellite is shielded against all forces but gravity and a system of thrusters is commanded by a control algorithm such that the relative displacement between the reference and the satellite stays constant. The main input to that control algorithm is the output of a sensor which measures the relative displacement between the satellite and the test mass. Internal disturbance forces such as electrostatic or magnetic forces cannot be canceled out his way and have to be minimized by a careful design of the satellite. A drag-free technology package is under development at Stanford since 2004. It includes an optical displacement sensor to measure the relative position of the test mass inside the satellite, a caging mechanism to lock the test mass during launch, a UV LED based charge management system to minimize the effect of electrostatic forces, a thermal enclosure, and the drag-free control algorithms. Possible applications of drag-free satellites in fundamental physics (Gravity Probe B, LISA), geodesy (GOCE), and navigation (TRIAD I). In this presentation we will highlight the progress of the technology development towards a drag-free mission. The planned mission on a SaudiSat bus will demonstrate drag-free technology on a small spacecraft at a fraction of the cost of previous drag-free missions. The target acceleration noise is 10-12 m/sec2. With multiple such satellites a GRACE-like mission with improved sensitivity and potentially improved spatial and temporal resolution can be achieved.

  4. Attenuation of bulk organic matter, nutrients (N and P), and pathogen indicators during soil passage: Effect of temperature and redox conditions in simulated soil aquifer treatment (SAT)

    KAUST Repository

    Abel, Chol D T

    2012-07-22

    Soil aquifer treatment (SAT) is a costeffective natural wastewater treatment and reuse technology. It is an environmentally friendly technology that does not require chemical usage and is applicable to both developing and developed countries. However, the presence of organic matter, nutrients, and pathogens poses a major health threat to the population exposed to partially treated wastewater or reclaimed water through SAT. Laboratory-based soil column and batch experiments simulating SAT were conducted to examine the influence of temperature variation and oxidation-reduction (redox) conditions on removal of bulk organic matter, nutrients, and indicator microorganisms using primary effluent. While an average dissolved organic carbon (DOC) removal of 17.7 % was achieved in soil columns at 5 °C, removal at higher temperatures increased by 10 % increments with increase in temperature by 5 °C over the range of 15 to 25 °C. Furthermore, soil column and batch experiments conducted under different redox conditions revealed higher DOC removal in aerobic (oxic) experiments compared to anoxic experiments. Aerobic soil columns exhibited DOC removal 15 % higher than that achieved in the anoxic columns, while aerobic batch showed DOC removal 7.8 % higher than the corresponding anoxic batch experiments. Ammonium-nitrogen removal greater than 99 % was observed at 20 and 25 °C, while 89.7 % was removed at 15 °C, but the removal substantially decreased to 8.8 % at 5 °C. While ammonium-nitrogen was attenuated by 99.9 % in aerobic batch reactors carried out at room temperature, anoxic experiments under similar conditions revealed 12.1 % ammonium-nitrogen reduction, corresponding to increase in nitrate-nitrogen and decrease in sulfate concentration. © Springer Science+Business Media B.V. 2012.

  5. Urano y sus dos satélites irregulares recientemente descubiertos

    Science.gov (United States)

    Parisi, M. G.; Brunini, A.

    Hasta hace poco tiempo, Urano era el único de los Planetas Gigantes que no poseía satélites irregulares. Esto lo diferenciaba del resto de los planetas Gigantes, al igual que la peculiar oblicuidad de su eje de spin. La gran inclinación de su eje de rotación se debe probablemente a una colisión que sufrió el planeta con otro embrión planetario al final del proceso de formación. Esta colisión habría desligado satélites exteriores preexistentes del planeta. Recientemente se han descubierto dos satélites irregulares de Urano, lo que introduce algunas nuevas cotas y condiciones en el escenario de la "Hipótesis de la Gran Colisión" . Los satélites irregulares de Urano tuvieron que ser capturados en una etapa posterior a la del escenario de la Gran Colisión, de no ser así, hubieran sido eyectados del sistema por el impulso impartido con ese gran impacto. En este trabajo, se discuten los posibles mecanismos de captura de los satélites irregulares y se presenta un nuevo posible mecanismo para dicha captura.

  6. CubeSat mission design based on a systems engineering approach

    Science.gov (United States)

    Asundi, S. A.; Fitz-Coy, N. G.

    With the exception of the CubeSat specification, CubeSat design and development approaches have been mostly ad hoc, which has questioned their reliability. A systems engineering approach, based on the guidelines of NASA's Systems Engineering Handbook has been developed for CubeSats to facilitate systematic design, development and address their reliability, traceability, and reusability. The CubeSat systems engineering approach, developed as a repeatable process, uses a top-down design methodology to translate mission definitions into basic building blocks, components, interfaces and tasks, that then facilitate a bottom-up development and fabrication process. Some of the design tools (e.g., N2 diagram) described in NASAs Systems Engineering Handbook are utilized early in the design phase to identify potential conflicts in the mechanical and electrical interfaces. A novel subsystem level flowdown, which transcribes the system level requirements into identifiable CubeSat subsystems, (i.e., building blocks) is described. Utilizing this approach yields full traceability from mission concept to subsystem component to flight software. Additionally, the approach facilitates the estimation of the mission overhead in terms of power, telemetry, and computation associated with each component, interface, and task.

  7. Proteomic analysis reveals a novel function of the kinase Sat4p in Saccharomyces cerevisiae mitochondria.

    Directory of Open Access Journals (Sweden)

    Uta Gey

    Full Text Available The Saccharomyces cerevisiae kinase Sat4p has been originally identified as a protein involved in salt tolerance and stabilization of plasma membrane transporters, implicating a cytoplasmic localization. Our study revealed an additional mitochondrial (mt localization, suggesting a dual function for Sat4p. While no mt related phenotype was observed in the absence of Sat4p, its overexpression resulted in significant changes of a specific mitochondrial subproteome. As shown by a comparative two dimensional difference gel electrophoresis (2D-DIGE approach combined with mass spectrometry, particularly two groups of proteins were affected: the iron-sulfur containing aconitase-type proteins (Aco1p, Lys4p and the lipoamide-containing subproteome (Lat1p, Kgd2p and Gcv3p. The lipoylation sites of all three proteins could be assigned by nanoLC-MS/MS to Lys75 (Lat1p, Lys114 (Kgd2p and Lys102 (Gcv3p, respectively. Sat4p overexpression resulted in accumulation of the delipoylated protein variants and in reduced levels of aconitase-type proteins, accompanied by a decrease in the activities of the respective enzyme complexes. We propose a regulatory role of Sat4p in the late steps of the maturation of a specific subset of mitochondrial iron-sulfur cluster proteins, including Aco1p and lipoate synthase Lip5p. Impairment of the latter enzyme may account for the observed lipoylation defects.

  8. Efficient and Reliable Solar Panels for Small CubeSat Picosatellites

    Directory of Open Access Journals (Sweden)

    Ivo Vertat

    2014-01-01

    Full Text Available CubeSat picosatellites have a limited area of walls for solar cells assembling and the available area has to be effectively shared with other parts, such as planar antennas, optical sensors, camera lens, and access port. With standard size of solar cell strings, it is not possible to construct a reliable solar panel for CubeSat with redundant strings interconnection. Typical solar panels for CubeSat consist of two solar cell strings serially wired with no redundancy in case of solar string failure. The loss of electric energy from one solar panel can cause a serious problem for most picosatellites due to minimum margin in the blueprints of the picosatellite subsystem power budget. In this paper, we propose a new architecture of solar panels for PilsenCUBE CubeSat with a high level of redundancy in the case of solar string failure or following switched power regulator failure. Our solar panels use a high efficiency triple junction GaInP2/GaAs/Ge in the form of small triangle strings from the Spectrolab Company. A suitable technology for precise solar cell assembling is also discussed, because CubeSat picosatellites are usually developed by small teams with limited access to high-end facilities.

  9. Sampling and sensitivity analyses tools (SaSAT for computational modelling

    Directory of Open Access Journals (Sweden)

    Wilson David P

    2008-02-01

    Full Text Available Abstract SaSAT (Sampling and Sensitivity Analysis Tools is a user-friendly software package for applying uncertainty and sensitivity analyses to mathematical and computational models of arbitrary complexity and context. The toolbox is built in Matlab®, a numerical mathematical software package, and utilises algorithms contained in the Matlab® Statistics Toolbox. However, Matlab® is not required to use SaSAT as the software package is provided as an executable file with all the necessary supplementary files. The SaSAT package is also designed to work seamlessly with Microsoft Excel but no functionality is forfeited if that software is not available. A comprehensive suite of tools is provided to enable the following tasks to be easily performed: efficient and equitable sampling of parameter space by various methodologies; calculation of correlation coefficients; regression analysis; factor prioritisation; and graphical output of results, including response surfaces, tornado plots, and scatterplots. Use of SaSAT is exemplified by application to a simple epidemic model. To our knowledge, a number of the methods available in SaSAT for performing sensitivity analyses have not previously been used in epidemiological modelling and their usefulness in this context is demonstrated.

  10. Feasibility of assessing the needs of stroke patients after six months using the GM-SAT.

    Science.gov (United States)

    Rothwell, Katy; Boaden, Ruth; Bamford, David; Tyrrell, Pippa J

    2013-03-01

    To investigate the feasibility of administering the Greater Manchester Stroke Assessment Tool (GM-SAT), a structured evidence-based needs assessment tool, in a community setting and its acceptability to stroke patients and their carers. Community stroke services. One hundred and thirty-seven stroke patients at six months post hospital discharge with no communication or cognitive difficulties residing in their own homes. Patients' needs were assessed by information, advice and support (IAS) coordinators from the UK Stroke Association using the GM-SAT. Number and nature of unmet needs identified and actions required to address these; patient/carer feedback; and IAS coordinator feedback. The mean number of unmet needs identified was 3 (min 0, max 14; SD 2.5). The most frequently identified unmet needs related to fatigue (34.3%), memory, concentration and attention (25.5%), secondary prevention non-lifestyle (21.9%) and depression (19.0%). It was found that 50.4% of unmet needs could be addressed through the provision of information and advice. Patients/carers found the assessment process valuable and IAS coordinators found the GM-SAT easy to use. Results demonstrate that the GM-SAT is feasible to administer in the community using IAS coordinators and is acceptable to patients and their carers, as well as staff undertaking the assessments. Further research is needed to determine whether the application of the GM-SAT at six months improves outcomes for patients.

  11. Overview of the Systems Analysis Framework for the EU Bioeconomy. Deliverable 1.4 of the EU FP 7 SAT-BBE project Systems Analysis Tools Framework for the EU Bio-Based Economy Strategy (SAT BBE)

    NARCIS (Netherlands)

    Leeuwen, van M.G.A.; Meijl, van H.; Smeets, E.M.W.; Tabeau-Kowalska, E.W.

    2014-01-01

    In November 2012 the Systems Analysis Tools Framework for the EU Bio-Based Economy Strategy project (SAT-BBE) was launched with the purpose to design an analysis tool useful to monitoring the evolution and impacts of the bioeconomy. In the SAT-BBE project the development of the analysis tool for the

  12. Improving the Arctic Mean Sea Surface with CryoSat-2 Data

    DEFF Research Database (Denmark)

    Stenseng, Lars; Andersen, Ole Baltazar

    Bridge). The new state of the art DTU13MSS is a global high-resolution MSS that includes retracked CryoSat-2 data and thereby extends the polar data coverage up to 88 degrees latitude. Furthermore, in the sea-ice covered areas, the SAR and SARin feature of the altimeter on-board CryoSat-2 increases the amount...... an improvement of more than 20 cm between 82 and 88 degrees latitude. For the first time the three years of retracked CryoSat-2 data will, in combination with DTU13MSS, allow reliable estimation of the trend and annual variations in the high Arctic Ocean sea surface height....

  13. Impact of CryoSat-2 for marine gravity field - globally and in the Arctic Ocean

    DEFF Research Database (Denmark)

    Andersen, Ole Baltazar; Stenseng, Lars; Knudsen, Per

    -in) designed to improve the sea surface /ice height mapping in the Polar Regions. We have investigated the use of two years of CryoSat-2 LRM data as well as CryoSat SAR and SAR-in data for deriving a global gravity field as well as a regional marine gravity field in the Arctic. Both conventional ESA Level 2...... GDR data, NOAA LRM data, but also Level1b (LRM, SAR and SAR-in waveforms) data have been analyzed. A suite of eight different empirical retrackers have been developed and investigated for their ability to predict marine gravity in the Arctic Ocean. The impact of the various improvement offered by Cryo......Sat-2 in comparison with conventional satellite altimetry have been studied and quantified both globally but particularly for the Arctic Ocean using a large number of marine and airborne surveys providing “ground truth” marine gravity....

  14. A review of MEMS micropropulsion technologies for CubeSats and PocketQubes

    Science.gov (United States)

    Silva, Marsil A. C.; Guerrieri, Daduí C.; Cervone, Angelo; Gill, Eberhard

    2018-02-01

    CubeSats have been extensively used in the past decade as scientific tools, technology demonstrators and for education. Recently, PocketQubes have emerged as an interesting and even smaller alternative to CubeSats. However, both satellite types often lack some key capabilities, such as micropropulsion, in order to further extend the range of applications of these small satellites. This paper reviews the current development status of micropropulsion systems fabricated with MEMS (micro electro-mechanical systems) and silicon technology intended to be used in CubeSat or PocketQube missions and compares different technologies with respect to performance parameters such as thrust, specific impulse, and power as well as in terms of operational complexity. More than 30 different devices are analyzed and divided into 7 main categories according to the working principle. A specific outcome of the research is the identification of the current status of MEMS technologies for micropropulsion including key opportunities and challenges.

  15. Integrating BalloonSAT and Atmospheric Dynamic Concepts into the Secondary Classroom

    Science.gov (United States)

    Fong, B. N.; Kennon, J. T.; Roberts, E.

    2016-05-01

    Arkansas BalloonSAT is an educational outreach and scientific research program that is part of Arkansas State University in Jonesboro, AR. The following is a unit of instruction to incorporate BalloonSAT measurements into secondary science classes. Students interpret graphs and identify several atmospheric trends and properties of a typical balloon flight. Students engage critical thinking skills in developing and answering their own questions relevant to the BalloonSAT program. Prerequisite concepts students should know are how to interpret graphs and unit conversions. Students should have a basic understanding of gravity, units of temperature and distance, and error in measurements. The unit is designed for one week after end-of-course exams and before the end of school. The unit may take two to five 50-minute periods, depending on how many activities are completed.

  16. A variable neighborhood Walksat-based algorithm for MAX-SAT problems.

    Science.gov (United States)

    Bouhmala, Noureddine

    2014-01-01

    The simplicity of the maximum satisfiability problem (MAX-SAT) combined with its applicability in many areas of artificial intelligence and computing science made it one of the fundamental optimization problems. This NP-complete problem refers to the task of finding a variable assignment that satisfies the maximum number of clauses (or the sum of weights of satisfied clauses) in a Boolean formula. The Walksat algorithm is considered to be the main skeleton underlying almost all local search algorithms for MAX-SAT. Most local search algorithms including Walksat rely on the 1-flip neighborhood structure. This paper introduces a variable neighborhood walksat-based algorithm. The neighborhood structure can be combined easily using any local search algorithm. Its effectiveness is compared with existing algorithms using 1-flip neighborhood structure and solvers such as CCLS and Optimax from the eighth MAX-SAT evaluation.

  17. The effects of a Self-Alert Training (SAT program in adults with ADHD

    Directory of Open Access Journals (Sweden)

    Simona eSalomone

    2015-02-01

    Full Text Available Attention-Deficit/Hyperactivity Disorder (ADHD, a neuropsychiatric condition characterised by attention and impulsivity problems, is one of the most common behavioral disorders. The first line of treatment for ADHD is psychostimulant medication, but this has limited effectiveness, particularly in adults, and is often associated with adverse side-effects. Thus, it is imperative that new non-pharmaceutical approaches to treatment are developed. This study aims to evaluate the impact of a non-pharmacological Self-Alert Training (SAT intervention on ADHD symptom prevalence, psychological and cognitive functioning, and on everyday functional impairment in adults with ADHD. Fifty-one adult participants with a current diagnosis of ADHD were randomized to either SAT or a Control Training (CT program. They were assessed at baseline, immediately following the 5-week training period, and after 3 months using ADHD symptoms scales, as well as a series of neuropsychological tests and psychological questionnaires. Subjective ratings of everyday life attention and memory problems were also collected. The SAT group showed significant improvements in ADHD inattentive and impulsive symptoms, depressive symptoms and in self-efficacy ratings compared to the CT group at both post-training and at the 3-month assessment. Pre-post improvements in SAT participants on untrained cognitive tasks measuring selective attention and executive functions were also observed. Finally, the SAT group reported improved subjective ratings of everyday life attention at both assessment points. This pattern of results suggests that SAT may be beneficial in treating ADHD symptoms as well as psychological and cognitive impairments in adult ADHD. A large-scale randomized controlled trial is needed.

  18. Global snowfall: A combined CloudSat, GPM, and reanalysis perspective.

    Science.gov (United States)

    Milani, Lisa; Kulie, Mark S.; Skofronick-Jackson, Gail; Munchak, S. Joseph; Wood, Norman B.; Levizzani, Vincenzo

    2017-04-01

    Quantitative global snowfall estimates derived from multi-year data records will be presented to highlight recent advances in high latitude precipitation retrievals using spaceborne observations. More specifically, the analysis features the 2006-2016 CloudSat Cloud Profiling Radar (CPR) and the 2014-2016 Global Precipitation (GPM) Microwave Imager (GMI) and Dual-frequency Precipitation Radar (DPR) observational datasets and derived products. The ERA-Interim reanalysis dataset is also used to define the meteorological context and an independent combined modeling/observational evaluation dataset. An overview is first provided of CloudSat CPR-derived results that have stimulated significant recent research regarding global snowfall, including seasonal analyses of unique snowfall modes. GMI and DPR global annual snowfall retrievals are then evaluated against the CloudSat estimates to highlight regions where the datasets provide both consistent and diverging snowfall estimates. A hemispheric seasonal analysis for both datasets will also be provided. These comparisons aim at providing a unified global snowfall characterization that leverages the respective instrument's strengths. Attention will also be devoted to regions around the globe that experience unique snowfall modes. For instance, CloudSat has demonstrated an ability to effectively discern snowfall produced by shallow cumuliform cloud structures (e.g., lake/ocean-induced convective snow produced by air/water interactions associated with seasonal cold air outbreaks). The CloudSat snowfall database also reveals prevalent seasonal shallow cumuliform snowfall trends over climate-sensitive regions like the Greenland Ice Sheet. Other regions with unique snowfall modes, such as the US East Coast winter storm track zone that experiences intense snowfall rates directly associated with strong low pressure systems, will also be highlighted to demonstrate GPM's observational effectiveness. Linkages between CloudSat and GPM

  19. Ability of sat-1 to transport sulfate, bicarbonate, or oxalate under physiological conditions.

    Science.gov (United States)

    Krick, Wolfgang; Schnedler, Nina; Burckhardt, Gerhard; Burckhardt, Birgitta C

    2009-07-01

    Tubular reabsorption of sulfate is achieved by the sodium-dependent sulfate transporter, NaSi-1, located at the apical membrane, and the sulfate-anion exchanger, sat-1, located at the basolateral membrane. To delineate the physiological role of rat sat-1, [(35)S]sulfate and [(14)C]oxalate uptake into sat-1-expressing oocytes was determined under various experimental conditions. Influx of [(35)S]sulfate was inhibited by bicarbonate, thiosulfate, sulfite, and oxalate, but not by sulfamate and sulfide, in a competitive manner with K(i) values of 2.7 +/- 1.3 mM, 101.7 +/- 9.7 microM, 53.8 +/- 10.9 microM, and 63.5 +/- 38.7 microM, respectively. Vice versa, [(14)C]oxalate uptake was inhibited by sulfate with a K(i) of 85.9 +/- 9.5 microM. The competitive type of inhibition indicates that these compounds are most likely substrates of sat-1. Physiological plasma bicarbonate concentrations (25 mM) reduced sulfate and oxalate uptake by more than 75%. Simultaneous application of sulfate, bicarbonate, and oxalate abolished sulfate as well as oxalate uptake. These data and electrophysiological studies using a two-electrode voltage-clamp device provide evidence that sat-1 preferentially works as an electroneutral sulfate-bicarbonate or oxalate-bicarbonate exchanger. In kidney proximal tubule cells, sat-1 likely completes sulfate reabsorption from the ultrafiltrate across the basolateral membrane in exchange for bicarbonate. In hepatocytes, oxalate extrusion is most probably mediated either by an exchange for sulfate or bicarbonate.

  20. The effects of a Self-Alert Training (SAT) program in adults with ADHD.

    Science.gov (United States)

    Salomone, Simona; Fleming, Grainne R; Shanahan, Jacqueline M; Castorina, Marco; Bramham, Jessica; O'Connell, Redmond G; Robertson, Ian H

    2015-01-01

    Attention-Deficit/Hyperactivity Disorder (ADHD), a neuropsychiatric condition characterized by attention and impulsivity problems, is one of the most common behavioral disorders. The first line of treatment for ADHD is psychostimulant medication, but this has limited effectiveness, particularly in adults, and is often associated with adverse side-effects. Thus, it is imperative that new non-pharmaceutical approaches to treatment are developed. This study aims to evaluate the impact of a non-pharmacological Self-Alert Training (SAT) intervention on ADHD symptom prevalence, psychological and cognitive functioning, and on everyday functional impairment in adults with ADHD. Fifty-one adult participants with a current diagnosis of ADHD were randomized to either SAT or a Control Training (CT) program. They were assessed at baseline, immediately following the 5-week training period, and after 3-months using ADHD symptoms scales, as well as a series of neuropsychological tests and psychological questionnaires. Subjective ratings of everyday life attention and memory problems were also collected. The SAT group showed significant improvements in ADHD inattentive and impulsive symptoms, depressive symptoms and in self-efficacy ratings compared to the CT group at both post-training and at the 3-month assessment. Pre-post improvements in SAT participants on untrained cognitive tasks measuring selective attention and executive functions were also observed. Finally, the SAT group reported improved subjective ratings of everyday life attention at both assessment points. This pattern of results suggests that SAT may be beneficial in treating ADHD symptoms as well as psychological and cognitive impairments in adult ADHD. A large-scale randomized controlled trial (RCT) is needed.

  1. AIRS-CloudSat cloud mask, radar reflectivities, and cloud classification matchups V3.2 (AIRS_CPR_MAT) at GES DISC

    Data.gov (United States)

    National Aeronautics and Space Administration — This is AIRS-CloudSat collocated subset, in NetCDF-4 format. These data contain collocated: AIRS Level 1b radiances spectra, CloudSat radar reflectivities, and MODIS...

  2. AIRS-AMSU variables-CloudSat cloud mask, radar reflectivities, and cloud classification matchups V3.2 (AIRSM_CPR_MAT) at GES DISC

    Data.gov (United States)

    National Aeronautics and Space Administration — This is AIRS-CloudSat collocated subset, in NetCDF 4 format. These data contain collocated: AIRS/AMSU retrievals at AMSU footprints, CloudSat radar reflectivities,...

  3. SAT Participation and Performance and the Attainment of College and Career Readiness Benchmark Scores for the Class of 2013. Memorandum

    Science.gov (United States)

    Sanderson, Geoffrey T.

    2013-01-01

    This memorandum describes the SAT participation and performance for the Montgomery County (Maryland) Public Schools (MCPS) Class of 2013 compared with the graduating seniors in Maryland and the nation. Detailed results of SAT and ACT by high school and student group for graduates in 2011-2013 are included. MCPS students continue to outperform the…

  4. Design of an Air-Breathing Electric Thruster for CubeSat Applications

    Science.gov (United States)

    Jackson, Stephen W.

    The altitude range between 120 and 300 km is relatively unexplored with regard to space weather, atmospheric models, climate observations, the global electric circuit, remote sensing, and intelligence gathering. This altitude range is not conducive to to in situ measurements due to the high magnitudes of drag that are experienced by satellites at these altitudes. The concept of air-breathing propulsion systems have been proposed to counteract drag. These propulsion systems produce thrust through electrostatic propulsion by ionizing the background neutral atmospheric particles. The atmospheric neutral particles that are the cause of drag at these altitudes are used as the fuel source for these air-breathing thrusters. Systems have been conceptually designed for larger satellites, but in this work we show that is possible for CubeSats to employ similar systems. CubeSats are a relatively new technology that have allowed low cost satellites to be built by a variety of entities including universities and private companies at low cost and with rapid development cycles. Due to current restrictions, CubeSats are not allowed to carry propellant. This limits CubeSats from maneuvering, formation flying, orbit raising, drag make-up, and deorbiting. However, this has not prevented the study and design of propulsion systems for CubeSats, with the anticipation of the propellant restrictions being lifted. In this research, a concept for an air-breathing ion thruster is designed for the use in 3U, 6U, 12U, and 27U Cubesats. The design is created to be modular to this system, and each component is discussed separately. An analysis is conducted to determine the best inlet shape for capturing atmospheric particles. This analysis is conducted using a 3D Monte Carlo simulator. The ionization of atmospheric particles is investigated, and issues with ionization of the particles given the design of the system are discussed. Based on the expected inlet capture efficiency and ionization

  5. The QBito CubeSat: Applications in Space Engineering Education at Technical University of Madrid

    Science.gov (United States)

    Fernandez Fraile, Jose Javier; Laverón-Simavilla, Ana; Calvo, Daniel; Moreno Benavides, Efren

    The QBito CubeSat is one of the 50 CubeSats that is being developed for the QB50 project. The project is funded by the 7 (th) Frame Program to launch 50 CubeSats in a ‘string-of-pearls’ configuration for multi-point, in-situ measurements in the lower thermosphere and re-entry research. The 50 CubeSats, developed by an international network of universities and research institutions, will comprise 40 double CubeSats with atmospheric sensors and 10 double or triple CubeSats for science and technology demonstration. It will be the first large-scale CubeSat constellation in orbit; a concept that has been under discussion for several years but not implemented up to now. This project has a high educational interest for universities; beyond the scientific and technological results, being part of an international group of over 90 universities all over the world working and sharing knowledge to achieve a successful mission represents an exciting opportunity. The QBito project main educational motivation is to educate students in space technologies and in space systems engineering. The Universidad Politécnica de Madrid (UPM) is designing, developing, building and testing one of the double CubeSats carrying as payload a kit of atmospheric sensors from the consortium, and other payloads developed by the team such as an IR non-refrigerated sensor, a Phase Change Material (PCM) for thermal control applications, a Fuzzy Logic Attitude Control System and other technological developments such as an optimized antenna deployment mechanism, a lightweight multi-mission configurable structure, and an efficient Electric Power System (EPS) with a Maximum Peak Power Tracker (MPPT). This project has been integrated in the training of the Aerospatiale Engineering, Master and PhD degree students by involving them in the complete engineering process, from its conceptual design to the post-flight conclusions. Three subsystems have been selected for being developed from the conceptual design

  6. A data assimilation system combining CryoSat-2 data and hydrodynamic river models

    DEFF Research Database (Denmark)

    Schneider, Raphael; Ridler, Marc-Etienne; Godiksen, Peter Nygaard

    2017-01-01

    There are numerous hydrologic studies using satellite altimetry data from repeat-orbit missions such as Envisat or Jason over rivers. This study is one of the first examples for the combination of altimetry from drifting-ground track satellite missions, namely CryoSat-2, with a river model. Cryo......Sat-2 SARIn Level 2 data is used to improve a 1D hydrodynamic model of the Brahmaputra River in South Asia, which is based on the Saint-Venant equations for unsteady flow and set up in the MIKE HYDRO River software. After calibration of discharge and water level the hydrodynamic model can accurately...

  7. Greenland 2012 melt event effects on CryoSat-2 radar altimetry

    DEFF Research Database (Denmark)

    Nilsson, Johan; Vallelonga, Paul Travis; Simonsen, Sebastian Bjerregaard

    2015-01-01

    CryoSat-2 data are used to study elevation changes over an area in the interior part of the Greenland Ice Sheet during the extreme melt event in July 2012. The penetration of the radar signal into dry snow depends heavily on the snow stratigraphy, and the rapid formation of refrozen ice layers can...... bias the surface elevations obtained from radar altimetry. We investigate the change in CryoSat-2 waveforms and elevation estimates over the melt event and interpret the findings by comparing in situ surface and snow pit observations from the North Greenland Eemian Ice Drilling Project camp...

  8. Integrated monitoring technologies for the management of a Soil-Aquifer-Treatment (SAT) system.

    Science.gov (United States)

    Papadopoulos, Alexandros; Kallioras, Andreas; Kofakis, Petros; Bumberger, Jan; Schmidt, Felix; Athanasiou, Georgios; Uzunoglou, Nikolaos; Amditis, Angelos; Dietrich, Peter

    2016-04-01

    Artificial recharge of groundwater has an important role to play in water reuse as treated wastewater effluent can be infiltrated into the ground for aquifer recharge. As the effluent moves through the soil and the aquifer, it undergoes significant quality improvements through physical, chemical, and biological processes in the underground environment. Collectively, these processes and the water quality improvement obtained are called soil-aquifer-treatment (SAT) or geopurification. The pilot site of Lavrion Technological & Cultural Park (LTCP) of the National Technical University of Athens (NTUA), involves the employment of plot infiltration basins at experimental scale, which will be using waters of impaired quality as a recharge source, and hence acting as a Soil-Aquifer-Treatment, SAT, system. Τhe LTCP site will be employed as a pilot SAT system complemented by new technological developments, which will be providing continuous monitoring of the quantitative and qualitative characteristics of infiltrating groundwater through all hydrologic zones (i.e. surface, unsaturated and saturated zone). This will be achieved by the development and installation of an integrated system of prototype sensing technologies, installed on-site, and offering a continuous evaluation of the performance of the SAT system. An integrated approach of the performance evaluation of any operating SAT system should aim at parallel monitoring of all hydrologic zones, proving the sustainability of all involved water quality treatment processes within unsaturated and saturated zone. Hence a prototype system of Time and Frequency Domain Reflectometry (TDR & FDR) sensors is developed and will be installed, in order to achieve continuous quantitative monitoring of the unsaturated zone through the entire soil column down to significant depths below the SAT basin. Additionally, the system contains two different radar-based sensing systems that will be offering (i) identification of preferential

  9. SAT2 Foot-and-Mouth Disease Virus Structurally Modified for Increased Thermostability.

    Science.gov (United States)

    Scott, Katherine A; Kotecha, Abhay; Seago, Julian; Ren, Jingshan; Fry, Elizabeth E; Stuart, David I; Charleston, Bryan; Maree, Francois F

    2017-05-15

    Foot-and-mouth disease virus (FMDV), particularly strains of the O and SAT serotypes, is notoriously unstable. Consequently, vaccines derived from heat-labile SAT viruses have been linked to the induction of immunity with a poor duration and hence require more frequent vaccinations to ensure protection. In silico calculations predicted residue substitutions that would increase interactions at the interpentamer interface, supporting increased stability. We assessed the stability of the 18 recombinant mutant viruses in regard to their growth kinetics, antigenicity, plaque morphology, genetic stability, and temperature, ionic, and pH stability by using Thermofluor and inactivation assays in order to evaluate potential SAT2 vaccine candidates with improved stability. The most stable mutant for temperature and pH stability was the S2093Y single mutant, while other promising mutants were the E3198A, L2094V, and S2093H single mutants and the F2062Y-H2087M-H3143V triple mutant. Although the S2093Y mutant had the greatest stability, it exhibited smaller plaques, a reduced growth rate, a change in monoclonal antibody footprint, and poor genetic stability properties compared to those of the wild-type virus. However, these factors affecting production can be overcome. The addition of 1 M NaCl was found to further increase the stability of the SAT2 panel of viruses. The S2093Y and S2093H mutants were selected for future use in stabilizing SAT2 vaccines.IMPORTANCE Foot-and-mouth disease virus (FMDV) causes a highly contagious acute vesicular disease in cloven-hoofed livestock and wildlife. The control of the disease by vaccination is essential, especially at livestock-wildlife interfaces. The instability of some serotypes, such as SAT2, affects the quality of vaccines and therefore the duration of immunity. We have shown that we can improve the stability of SAT2 viruses by mutating residues at the capsid interface through predictive modeling. This is an important finding for the

  10. Inexpensive CubeSat attitude estimation using COTS components and Unscented Kalman Filtering

    DEFF Research Database (Denmark)

    Larsen, Jesper Abildgaard; Vinther, Kasper

    2011-01-01

    This paper describes a quaternion implementation of an Unscented Kalman Filter for attitude estimation on CubeSats using measurements of a sun vector, a magnetic field vector and angular velocity. Using unit quaternions provides a singularity free attitude parameterization. However, the unity...... constraint requires a redesign of the Unscented Kalman Filter. Therefore, a quaternion error state is introduced. Emphasis has been put in making the implementation accessible to other CubeSat by using realistic models of COTS components used for attitude sensing and simulations have shown that the extra...

  11. Neix SatCat, el servidor més complet d'imatges de satèl·lit de Catalunya

    OpenAIRE

    Pons, Xavier

    2012-01-01

    SatCat ja està complet i la UAB i el CREAF poden mostrar la història recent del territori català vista des de l'espai. Aquesta iniciativa, pionera a l’estat espanyol, dóna accés a un banc històric d'imatges del territori català preses pels satèl·lits Landsat entre l'any 1972 i l'actualitat. La informació recollida en el servidor és pública i permetrà avançar en la recerca i l'estudi dels canvis del nostre territori. El Grup de Recerca Mètodes i Aplicacions en Teledetecció i Sistemes d’Informa...

  12. A comparative analysis of the sea ice freeboard from CryoSat. CryoVEx and IceBridge

    DEFF Research Database (Denmark)

    Kildegaard Rose, Stine; Connor, Laurence N.; Farrell, Sinead L.

    The CryoSat Validation Experiment (CryoVEx) has been conducted by ESA, to examine the uncertainties in the satellite measurement of e.g. sea ice thickness. In this study, we aim to estimate the sea ice freeboard from CryoSat-2, and compare it with the high-resolution Airborne Laser Scanner (ALS......) measurements collected along CryoSat-2 ground tracks from the CryoVEx 2012 campaign, together with NASA’s Operation IceBridge data. We will use the CryoSat SAR data level 1b (L1b) to discriminate the leads and from this, estimate the sea ice freeboard. Furthermore, we are looking at the CryoSat level 2 (L2...

  13. A study of radar altimetry signal penetration over percolation facies of the Greenland Ice Sheet as part of the 2011 CryoSat-2 Validation Experiment

    Science.gov (United States)

    de la Pena, S.; Nienow, P.; Wingham, D.

    2011-12-01

    The percolation zone of the Greenland Ice Sheet (GrIS) has a highly variable snowpack structure characterized by the presence of ice lenses, pipes and layers in the volume below the surface. The stratified snowpack and the abrupt densification of near-surface snow, caused by seasonal melt in this region, affect the penetration depth of radar signals and is a potential source of errors for elevation change estimates performed by satellite radar altimetry. As the percolation zone extends further up the ice sheet, it is important to investigate trends and short term variations in radar volume backscatter over large length scales. Continuous monitoring of accumulation and densification processes in this region will lead to improvements in elevation estimates made with radar altimetry, and ultimately to more accurate mass balance estimations. We present results from the 2011 CryoSat-2 Validation Experiment over Greenland, with the aim of comparing for the first time observations from SIRAL, the radar altimeter onboard CryoSat-2, with near-simultaneous field and airborne measurements. The main objective of this comparison is to characterize near-surface snow structure and Ku-Band radar signatures along the western slope of the GrIS (~2000-2600m) to improve our understanding of the SIRAL radar signal interaction with different snow facies. The area of study covers the transition from the percolation zone into the dry snow zone, at elevations between 2000m and 2600m. The observations reveal the effects that the summer melt intensity's elevation gradient has on near surface snowpack. Widespread ice layers were found buried under winter accumulation in areas believed until recently to have little or no seasonal melt. In-situ snow density and structure observations were made along with airborne radar altimetry and Very High Bandwidth (VHB) ground radar measurements to analyse volume backscatter with a spatial resolution not obtainable by satellite, and to assess the

  14. In female rats, ethylene glycol treatment elevates protein expression of hepatic and renal oxalate transporter sat-1 (Slc26a1) without inducing hyperoxaluria.

    Science.gov (United States)

    Breljak, Davorka; Brzica, Hrvoje; Vrhovac, Ivana; Micek, Vedran; Karaica, Dean; Ljubojević, Marija; Sekovanić, Ankica; Jurasović, Jasna; Rašić, Dubravka; Peraica, Maja; Lovrić, Mila; Schnedler, Nina; Henjakovic, Maja; Wegner, Waja; Burckhardt, Gerhard; Burckhardt, Birgitta C; Sabolić, Ivan

    2015-10-01

    To investigate whether the sex-dependent expression of hepatic and renal oxalate transporter sat-1 (Slc26a1) changes in a rat model of ethylene glycol (EG)-induced hyperoxaluria. Rats were given tap water (12 males and 12 females; controls) or EG (12 males and 12 females; 0.75% v/v in tap water) for one month. Oxaluric state was confirmed by biochemical parameters in blood plasma, urine, and tissues. Expression of sat-1 and rate-limiting enzymes of oxalate synthesis, alcohol dehydrogenase 1 (Adh1) and hydroxy-acid oxidase 1 (Hao1), was determined by immunocytochemistry (protein) and/or real time reverse transcription polymerase chain reaction (mRNA). EG-treated males had significantly higher (in μmol/L; mean±standard deviation) plasma (59.7±27.2 vs 12.9±4.1, Psat-1 protein and mRNA expression did not differ significantly between these groups. EG-treated females, in comparison with controls had significantly higher (in μmol/L) serum oxalate levels (18.8±2.9 vs 11.6±4.9, Psat-1 protein, but not mRNA. The mRNA expression of Adh1 was female-dominant and that of Hao1 male-dominant, but both were unaffected by EG treatment. An increased expression of hepatic and renal oxalate transporting protein sat-1 in EG-treated female rats could protect from hyperoxaluria and oxalate urolithiasis.

  15. Vertical Structures of Anvil Clouds of Tropical Mesoscale Convective Systems Observed by CloudSat

    Science.gov (United States)

    Yuan, J.; Houze, R. A., Jr.; Heymsfield, A.

    2011-01-01

    A global study of the vertical structures of the clouds of tropical mesoscale convective systems (MCSs) has been carried out with data from the CloudSat Cloud Profiling Radar. Tropical MCSs are found to be dominated by cloud-top heights greater than 10 km. Secondary cloud layers sometimes occur in MCSs, but outside their primary raining cores. The secondary layers have tops at 6--8 and 1--3 km. High-topped clouds extend outward from raining cores of MCSs to form anvil clouds. Closest to the raining cores, the anvils tend to have broader distributions of reflectivity at all levels, with the modal values at higher reflectivity in their lower levels. Portions of anvil clouds far away from the raining core are thin and have narrow frequency distributions of reflectivity at all levels with overall weaker values. This difference likely reflects ice particle fallout and therefore cloud age. Reflectivity histograms of MCS anvil clouds vary little across the tropics, except that (i) in continental MCS anvils, broader distributions of reflectivity occur at the uppermost levels in the portions closest to active raining areas; (ii) the frequency of occurrence of stronger reflectivity in the upper part of anvils decreases faster with increasing distance in continental MCSs; and (iii) narrower-peaked ridges are prominent in reflectivity histograms of thick anvil clouds close to the raining areas of connected MCSs (superclusters). These global results are consistent with observations at ground sites and aircraft data. They present a comprehensive test dataset for models aiming to simulate process-based upper-level cloud structure around the tropics.

  16. Vertical Structures of Anvil Clouds of Tropical Mesoscale Convective Systems Observed by CloudSat

    Science.gov (United States)

    Hence, Deanna A.; Houze, Robert A.

    2011-01-01

    A global study of the vertical structures of the clouds of tropical mesoscale convective systems (MCSs) has been carried out with data from the CloudSat Cloud Profiling Radar. Tropical MCSs are found to be dominated by cloud-top heights greater than 10 km. Secondary cloud layers sometimes occur in MCSs, but outside their primary raining cores. The secondary layers have tops at 6 8 and 1 3 km. High-topped clouds extend outward from raining cores of MCSs to form anvil clouds. Closest to the raining cores, the anvils tend to have broader distributions of reflectivity at all levels, with the modal values at higher reflectivity in their lower levels. Portions of anvil clouds far away from the raining core are thin and have narrow frequency distributions of reflectivity at all levels with overall weaker values. This difference likely reflects ice particle fallout and therefore cloud age. Reflectivity histograms of MCS anvil clouds vary little across the tropics, except that (i) in continental MCS anvils, broader distributions of reflectivity occur at the uppermost levels in the portions closest to active raining areas; (ii) the frequency of occurrence of stronger reflectivity in the upper part of anvils decreases faster with increasing distance in continental MCSs; and (iii) narrower-peaked ridges are prominent in reflectivity histograms of thick anvil clouds close to the raining areas of connected MCSs (superclusters). These global results are consistent with observations at ground sites and aircraft data. They present a comprehensive test dataset for models aiming to simulate process-based upper-level cloud structure around the tropics.

  17. The MicroMAS CubeSat Mission

    Science.gov (United States)

    Cahoy, K.; Blackwell, W. J.; Allen, G.; Bury, M.; Efromson, R.; Galbraith, C.; Hancock, T.; Leslie, V.; Osaretin, I.; Retherford, L.; Scarito, M.; Shields, M.; Toher, D.; Wight, K.; Miller, D.; Marinan, A.; Paek, S.; Peters, E.; Schmidt, F. H.; Alvisio, B.; Wise, E.; Masterson, R.; Franzim Miranda, D.; Crail, C.; Kingsbury, R.; Souffrant, A.; Orrego, L.; Eslinger, G.; Nicholas, A.; Pong, C.

    2012-12-01

    The recently published Midterm Assessment of NASA's Implementation of the Decadal Survey finds that, "The nation's Earth observing system is beginning a rapid decline in capability as long-running missions end and key new missions are delayed, lost, or canceled. The projected loss of observing capability could have significant adverse consequences for science and society." In this presentation, we explore low-cost, mission-flexible, and rapidly deployable spaceborne sensors that can meet stringent performance requirements pervading the NASA Earth Science measurement programs, including especially the recommended NRC Decadal Survey missions. New technologies have enabled a novel approach toward this science observational goal, and in this paper we describe recent technology develop efforts to address the challenges above through the use of CubeSat radiometers. The Micro-sized Microwave Atmospheric Satellite (MicroMAS) is a 3U cubesat (30x10x10 cm, ~4kg) hosting a passive microwave spectrometer operating near the 118.75-GHz oxygen absorption line. The focus of the first MicroMAS mission (hereafter, MicroMAS-1) is to observe convective thunderstorms, tropical cyclones, and hurricanes from a near-equatorial orbit at approximately 500-km altitude. A MicroMAS flight unit is currently being developed in anticipation of a 2014 launch to be provided by NASA. A parabolic reflector is mechanically rotated as the spacecraft orbits the earth, thus directing a cross-track scanned beam with FWHM beamwidth of 2.4-degrees, yielding an approximately 25-km diameter footprint from a nominal altitude of 500 km. Radiometric calibration is carried out using observations of cold space, the earth's limb, and an internal noise diode that is weakly coupled through the RF front-end electronics. A key technology feature is the development of an ultra-compact intermediate frequency processor module for channelization, detection, and A-to-D conversion. The antenna system and RF front

  18. Higher Education.

    Science.gov (United States)

    Hendrickson, Robert M.

    This chapter reviews litigation in higher education for 1986. The first section discusses the relationship between postsecondary institutions and various governmental agencies, in which litigation covers questions on the authority of boards, access to information through sunshine laws, questions of tax exempt status, and issues of accreditation.…

  19. The determination of the attitude and attitude dynamics of TeamSat

    DEFF Research Database (Denmark)

    Betto, Maurizio; Jørgensen, John Leif; Riis, Troels

    1999-01-01

    The second qualification flight of Ariane 5 was launched from the European Space Port in French Guiana on October 30, 1997. It carried on board a small technology demonstration satellite dubbed TeamSat into which five experiments, proposed by various universities and research institutions, were i...

  20. Solving the SAT problem using a DNA computing algorithm based on ligase chain reaction.

    Science.gov (United States)

    Wang, Xiaolong; Bao, Zhenmin; Hu, Jingjie; Wang, Shi; Zhan, Aibin

    2008-01-01

    A new DNA computing algorithm based on a ligase chain reaction is demonstrated to solve an SAT problem. The proposed DNA algorithm can solve an n-variable m-clause SAT problem in m steps and the computation time required is O (3m+n). Instead of generating the full-solution DNA library, we start with an empty test tube and then generate solutions that partially satisfy the SAT formula. These partial solutions are then extended step by step by the ligation of new variables using Taq DNA ligase. Correct strands are amplified and false strands are pruned by a ligase chain reaction (LCR) as soon as they fail to satisfy the conditions. If we score and sort the clauses, we can use this algorithm to markedly reduce the number of DNA strands required throughout the computing process. In a computer simulation, the maximum number of DNA strands required was 2(0.48n) when n=50, and the exponent ratio varied inversely with the number of variables n and the clause/variable ratio m/n. This algorithm is highly space-efficient and error-tolerant compared to conventional brute-force searching, and thus can be scaled-up to solve large and hard SAT problems.

  1. A systematic risk management approach employed on the CloudSat project

    Science.gov (United States)

    Basilio, R. R.; Plourde, K. S.; Lam, T.

    2000-01-01

    The CloudSat Project has developed a simplified approach for fault tree analysis and probabilistic risk assessment. A system-level fault tree has been constructed to identify credible fault scenarios and failure modes leading up to a potential failure to meet the nominal mission success criteria.

  2. Initial results of CryoSat-2 data from the Arctic

    DEFF Research Database (Denmark)

    Kildegaard Poulsen, Stine; Stenseng, Lars; Skourup, Henriette

    2011-01-01

    between the SAR backscatter and the CryoSat-2 data. The surface elevation is extracted from an 80% threshold retracker and a five parameter - retracker, and this is given with respect to the DTU10 Mean Sea Surface model (MSS). The results are compared with an Envisat ASAR image, and we show...

  3. Validation of CryoSat-2 Performance over Arctic Sea Ice

    DEFF Research Database (Denmark)

    di Bella, Alessandro; Skourup, Henriette; Bouffard, J.

    The main objective of this work is to validate CryoSat-2 (CS2) SARIn performance over sea ice by use of airborne laser altimetry data obtained during the CryoVEx 2012 campaign. A study by [1] has shown that the extra information from the CS2 SARIn mode increases the number of valid sea surface...

  4. Multidirectional Cosmic Ray Ion Detector for Deep Space CubeSats

    Science.gov (United States)

    Wrbanek, John D.; Wrbanek, Susan Y.

    2016-01-01

    NASA Glenn Research Center has proposed a CubeSat-based instrument to study solar and cosmic ray ions in lunar orbit or deep space. The objective of Solar Proton Anisotropy and Galactic cosmic ray High Energy Transport Instrument (SPAGHETI) is to provide multi-directional ion data to further understand anisotropies in SEP and GCR flux.

  5. Keyword Mnemonic Strategy: A Study of SAT Vocabulary in High School English

    Science.gov (United States)

    DeWitt, Kristina Callihan

    2010-01-01

    The purpose for this research study was to introduce and develop supplementary English material for SAT vocabulary instruction by providing memory-enhancing strategies for students with and without disabilities. Five inclusive English classrooms were assigned treatments in a within-subjects crossover design where all students received both…

  6. Design and Validation of an Innovative Data Bus Architecture for CubeSats

    NARCIS (Netherlands)

    van der Linden, Steven; Bouwmeester, J.; Povolac, A.

    2016-01-01

    Since the first successful CubeSat missions in the early 2000s, payloads for this form factor have emerged and have increased in technical performance level. This trend is likely to continue in the near future. However, despite the subsequent increase in data load and the increasing modularity of

  7. A Satellite Data Analysis and CubeSat Instrument Simulator Tool for ...

    Indian Academy of Sciences (India)

    Jordan Vannitsen

    2017-11-27

    spacecraft measure- ments—CubeSat—Mars. 1. Introduction. BIRDY is a 3-Unit CubeSat that is piggy-backed on a host mission to Mars and jettisoned at the beginning of the journey (Segret et al. 2014). The asset of such.

  8. Combining Envisat and CryoSat-2 altimetry to inform hydrodynamic models

    DEFF Research Database (Denmark)

    Schneider, Raphael; Nygaard Godiksen, Peter; Ridler, Marc-Etienne

    2016-01-01

    Decreasing availability of in-situ river monitoring datacan be met with increasing availability and quality ofsatellite altimetry data over rivers. CryoSat-2 is analtimeter mission launched in 2010 by the EuropeanSpace Agency (ESA). With its unique drifting orbit,common procedures of working with...

  9. Soft X-ray Focusing Telescope Aboard AstroSat: Design ...

    Indian Academy of Sciences (India)

    K. P. Singh

    2017-06-19

    Jun 19, 2017 ... Soft X-ray Focusing Telescope Aboard AstroSat: Design, Characteristics and Performance. K. P. SINGH1,∗ ... Here, we present an overview of its design, mechanical hardware, electronics, data modes, observational ..... products using the SXT pipeline software. The pipeline requires Level-1 data files and ...

  10. The ACT and SAT: No Longer Just College Admission Tests. Policy Brief

    Science.gov (United States)

    Hite, Jenny; Lord, Joan

    2014-01-01

    This brief report offers analysis of ACT and SAT results from 2008 to 2013 in the Southern Regional Education Board (SREB) region. The brief focuses on the increase in test participation rates and points to policies that SREB states initiated that affected these rates. Five SREB states currently require 100 percent student participation on the…

  11. A New Approach on the Physical Architecture of CubeSats & PocketQubes

    NARCIS (Netherlands)

    Bouwmeester, J.; Gill, E.K.A.; Speretta, S.; Uludag, M.S.

    2017-01-01

    The dominant architectural approach in CubeSats and PocketQubes is the use of modular physical units, each hosting (part of the) components of classical (virtual) subsystems. Many of these small satellites, however, also host
    subsystems or experiments with slightly alternative approach, e.g.

  12. Foot-and-Mouth Disease Virus Serotype SAT 3 in Long-Horned Ankole Calf, Uganda

    DEFF Research Database (Denmark)

    Dhikusooka, Moses Tefula; Tjørnehøj, Kirsten; Ayebazibwe, Chrisostom

    2015-01-01

    After a 16-year interval, foot-and-mouth disease virus serotype SAT 3 was isolated in 2013 from an apparently healthy long-horned Ankole calf that grazed close to buffalo in Uganda. The emergent virus strain is ≈20% different in nucleotide sequence (encoding VP1 [viral protein 1]) from its closest...

  13. Combining Decision Diagrams and SAT Procedures for Efficient Symbolic Model Checking

    DEFF Research Database (Denmark)

    Williams, Poul Frederick; Biere, Armin; Clarke, Edmund M.

    2000-01-01

    , combined with BDDs and SAT-solvers to perform satisfiability checking. As a result we are able to model check systems for which standard BDD-based methods fail. For example, we model check a liveness property of a 256 bit shift-and-add multiplier and we are able to find a previously undetected bug...

  14. Nine Facts about the SAT That Might Surprise You. Statistical Report

    Science.gov (United States)

    Letukas, Lynn

    2015-01-01

    The purpose of this document is to identify and dispel rumors that are frequently cited about the SAT. The following is a compilation of nine popular rumors organized into three areas: "Student Demographics," "Test Preparation/Test Prediction," and "Test Utilization."

  15. Foot-and-mouth disease virus serotype SAT 3 in long-horned Ankole calf, Uganda.

    Science.gov (United States)

    Dhikusooka, Moses Tefula; Tjørnehøj, Kirsten; Ayebazibwe, Chrisostom; Namatovu, Alice; Ruhweza, Simon; Siegismund, Hans Redlef; Wekesa, Sabenzia Nabalayo; Normann, Preben; Belsham, Graham J

    2015-01-01

    After a 16-year interval, foot-and-mouth disease virus serotype SAT 3 was isolated in 2013 from an apparently healthy long-horned Ankole calf that grazed close to buffalo in Uganda. The emergent virus strain is ≈20% different in nucleotide sequence (encoding VP1 [viral protein 1]) from its closest relatives isolated previously from buffalo in Uganda.

  16. Evaluation of different adjuvants for foot-and-mouth disease vaccine containing all the SAT serotypes.

    Science.gov (United States)

    Cloete, M; Dungu, B; Van Staden, L I; Ismail-Cassim, N; Vosloo, W

    2008-03-01

    Foot-and-mouth disease (FMD) is an economically important disease of cloven-hoofed animals that is primarily controlled by vaccination of susceptible animals and movement restrictions for animals and animal-derived products in South Africa. Vaccination using aluminium hydroxide gel-saponin (AS) adjuvanted vaccines containing the South African Territories (SAT) serotypes has been shown to be effective both in ensuring that disease does not spread from the endemic to the free zone and in controlling outbreaks in the free zone. Various vaccine formulations containing antigens derived from the SAT serotypes were tested in cattle that were challenged 1 year later. Both the AS and ISA 206B vaccines adjuvanted with saponin protected cattle against virulent virus challenge. The oil-based ISA 206B-adjuvanted vaccine with and without stimulators was evaluated in a field trial and both elicited antibody responses that lasted for 1 year. Furthermore, the ISA 206 adjuvanted FMD vaccine protected groups of cattle against homologous virus challenge at very low payloads, while pigs vaccinated with an emergency ISA 206B-based FMD vaccine containing the SAT 1 vaccine strains were protected against the heterologous SAT 1 outbreak strain.

  17. Serological Detection of Foot and Mouth Disease Virus (Fmdv) Sat 1 ...

    African Journals Online (AJOL)

    For SAT 2 virus, Borno and Adamawa States had the highest prevalence with CF, (41.00 and 30.50%) and with NT (46.50 and 29.50%) respectively. These results are of economic significant, since the animals were not vaccinated against FMD. Further studies on other FMD virus serotypes in other states are advocated.

  18. Unfair Treatment? The Case of Freedle, the SAT, and the Standardization Approach to Differential Item Functioning

    Science.gov (United States)

    Santelices, Maria Veronica; Wilson, Mark

    2010-01-01

    In 2003, the "Harvard Educational Review" published a controversial article by Roy Freedle that claimed bias against African American students in the SAT college admissions test. Freedle's work stimulated national media attention and faced an onslaught of criticism from experts at the Educational Testing Service (ETS), the agency…

  19. Coastal sea level from inland CryoSat-2 interferometric SAR altimetry

    DEFF Research Database (Denmark)

    Abulaitijiang, Adili; Andersen, Ole Baltazar; Stenseng, Lars

    2015-01-01

    The European Space Agency's CryoSat-2 satellite can operate in a novel synthetic aperture radar interferometric (SARIn) mode where its nominal footprint (swath) is observed by two antennas and the phase difference between the signals is used to determination the exact location of the scatterer...

  20. Feasibility of asteroid exploration using CubeSats - ASPECT case study

    Science.gov (United States)

    Kohout, T.; Näsilä, A.; Tikka, T.; Granvik, M.; Kestilä, A.; Penttilä, A.; Kuhno, J.; Muinonen, K.; Viherkanto, K.

    2017-09-01

    ASPECT is a 3U CubeSat with a VIS-NIR spectral imager designed to study asteroids. It is designed around radiation-hardened platform with projected life time at least 3 months. It includes autonomous navigation, orbit correction, and data acquisition capabilities.

  1. The satellite DNA AflaSAT-1 in the A and B chromosomes of the grasshopper Abracris flavolineata.

    Science.gov (United States)

    Milani, Diogo; Ramos, Érica; Loreto, Vilma; Martí, Dardo Andrea; Cardoso, Adauto Lima; de Moraes, Karen Cristiane Martinez; Martins, Cesar; Cabral-de-Mello, Diogo Cavalcanti

    2017-08-29

    Satellite DNAs (satDNAs) are organized in repetitions directly contiguous to one another, forming long arrays and composing a large portion of eukaryote genomes. These sequences evolve according to the concerted evolution model, and homogenization of repeats is observed at the intragenomic level. Satellite DNAs are the primary component of heterochromatin, located primarily in centromeres and telomeres. Moreover, satDNA enrichment in specific chromosomes has been observed, such as in B chromosomes, that can provide clues about composition, origin and evolution of this chromosome. In this study, we isolated and characterized a satDNA in A and B chromosomes of Abracris flavolineata by integrating cytogenetic, molecular and genomics approaches at intra- and inter-population levels, with the aim to understand the evolution of satDNA and composition of B chromosomes. AflaSAT-1 satDNA was shared with other species and in A. flavolineata, was associated with another satDNA, AflaSAT-2. Chromosomal mapping revealed centromeric blocks variable in size in almost all chromosomes (except pair 11) of A complement for both satDNAs, whereas for B chromosome, only a small centromeric signal occurred. In distinct populations, variable number of AflaSAT-1 chromosomal sites correlated with variability in copy number. Instead of such variability, low sequence diversity was observed in A complement, but monomers from B chromosome were more variable, presenting also exclusive mutations. AflaSAT-1 was transcribed in five tissues of adults in distinct life cycle phases. The sharing of AflaSAT-1 with other species is consistent with the library hypothesis and indicates common origin in a common ancestor; however, AflaSAT-1 was highly amplified in the genome of A. flavolineata. At the population level, homogenization of repeats in distinct populations was documented, but dynamic expansion or elimination of repeats was also observed. Concerning the B chromosome, our data provided new

  2. Association Between Hepatitis C Virus Coinfection and Regional Adipose Tissue Volume in HIV-Infected Men and Women

    Science.gov (United States)

    Tien, Phyllis C.; Bacchetti, Peter; Gripshover, Barbara; Overton, E. Turner; Rimland, David; Kotler, Don

    2011-01-01

    Objective Coinfection with hepatitis C virus (HCV) is reported to be associated with a higher prevalence of lipodystrophy than HIV infection alone. We examine the association between HCV and adipose tissue volume in HIV-infected men and women. Methods Cross-sectional analysis of HIV-infected subjects from the study of Fat Redistribution and Metabolic Change in HIV Infection. MRI measured regional adipose tissue volume. Detectable HCV RNA defined HCV infection. Results Twenty percent of 792 men and 26% of 329 women were HIV/HCV-coinfected. HIV/HCV-coinfected and HIV-monoinfected women had similar amounts of subcutaneous adipose tissue (SAT) in the leg, lower trunk, upper trunk, and arm and similar amounts of visceral adipose tissue (VAT). Similar findings were seen in men, except in the leg and VAT. After adjustment, HCV infection remained associated with more leg fat in men (12.2%, 95% confidence interval [CI]: 0.3 to 25.3; P = 0.043). Among those on stavudine, HIV-monoinfected men had less leg fat (−7% effect per year of stavudine use, 95% CI: −9 to −5; P < 0.001); a weaker association was seen in HIV/HCV-coinfected men (−2% effect, 95% CI: −7 to 3; P = 0.45). Indinavir was associated with less leg fat (−4% in HIV-monoinfected men, 95% CI: −6 to −1; P = 0.002; −5% in HIV/HCV-coinfected men, 95% CI: −11 to 2; P = 0.14). Conclusions Our findings suggest that HIV/HCV coinfection is not associated with less SAT in men and women. HCV infection seems to mitigate the loss of leg fat seen in HIV-infected men on stavudine. PMID:17356466

  3. Quantifying uncertainties in radar forward models through a comparison between CloudSat and SPartICus reflectivity factors

    Science.gov (United States)

    Mascio, Jeana; Mace, Gerald G.

    2017-02-01

    Interpretations of remote sensing measurements collected in sample volumes containing ice-phase hydrometeors are very sensitive to assumptions regarding the distributions of mass with ice crystal dimension, otherwise known as mass-dimensional or m-D relationships. How these microphysical characteristics vary in nature is highly uncertain, resulting in significant uncertainty in algorithms that attempt to derive bulk microphysical properties from remote sensing measurements. This uncertainty extends to radar reflectivity factors forward calculated from model output because the statistics of the actual m-D in nature is not known. To investigate the variability in m-D relationships in cirrus clouds, reflectivity factors measured by CloudSat are combined with particle size distributions (PSDs) collected by coincident in situ aircraft by using an optimal estimation-based (OE) retrieval of the m-D power law. The PSDs were collected by 12 flights of the Stratton Park Engineering Company Learjet during the Small Particles in Cirrus campaign. We find that no specific habit emerges as preferred, and instead, we find that the microphysical characteristics of ice crystal populations tend to be distributed over a continuum-defying simple categorization. With the uncertainties derived from the OE algorithm, the uncertainties in forward-modeled backscatter cross section and, in turn, radar reflectivity is calculated by using a bootstrapping technique, allowing us to infer the uncertainties in forward-modeled radar reflectivity that would be appropriately applied to remote sensing simulator algorithms.

  4. Electrospray Thrusters for Attitude Control of a 1-U CubeSat

    Science.gov (United States)

    Timilsina, Navin

    With a rapid increase in the interest in use of nanosatellites in the past decade, finding a precise and low-power-consuming attitude control system for these satellites has been a real challenge. In this thesis, it is intended to design and test an electrospray thruster system that could perform the attitude control of a 1-unit CubeSat. Firstly, an experimental setup is built to calculate the conductivity of different liquids that could be used as propellants for the CubeSat. Secondly, a Time-Of-Flight experiment is performed to find out the thrust and specific impulse given by these liquids and hence selecting the optimum propellant. On the other hand, a colloidal thruster system for a 1-U CubeSat is designed in Solidworks and fabricated using Lathe and CNC Milling Machine. Afterwards, passive propellant feeding is tested in this thruster system. Finally, the electronic circuit and wireless control system necessary to remotely control the CubeSat is designed and the final testing is performed. Among the propellants studied, Ethyl ammonium nitrate (EAN) was selected as the best propellant for the CubeSat. Theoretical design and fabrication of the thruster system was performed successfully and so was the passive propellant feeding test. The satellite was assembled for the final experiment but unfortunately the microcontroller broke down during the first test and no promising results were found out. However, after proving that one thruster works with passive feeding, it could be said that the ACS testing would have worked if we had performed vacuum compatibility tests for other components beforehand.

  5. Microbial population shift caused by sulfamethoxazole in engineered-Soil Aquifer Treatment (e-SAT) system.

    Science.gov (United States)

    Rudrashetti, Ashwinkumar P; Jadeja, Niti B; Gandhi, Deepa; Juwarkar, Asha A; Sharma, Abhinav; Kapley, Atya; Pandey, R A

    2017-06-01

    The engineered-Soil Aquifer Treatment (e-SAT) system was exploited for the biological degradation of Sulfamethoxazole (SMX) which is known to bio-accumulate in the environment. The fate of SMX in soil column was studied through laboratory simulation for a period of 90 days. About 20 ppm SMX concentration could be removed in four consecutive cycles in e-SAT. To understand the microbial community change and biological degradation of SMX in e-SAT system, metagenomic analysis was performed for the soil samples before (A-EBD) and after SMX exposure (B-EBD) in the e-SAT. Four bacterial phyla were found to be present in both the samples, with sample B-EBD showing increased abundance for Actinobacteria, Bacteroidetes, Firmicutes and decreased Proteobacterial abundance compared to A-EBD. The unclassified bacteria were found to be abundant in B-EBD compared to A-EBD. At class level, classes such as Bacilli, Negativicutes, Deltaproteobacteria, and Bacteroidia emerged in sample B-EBD owing to SMX treatment, while Burkholderiales and Nitrosomonadales appeared to be dominant at order level after SMX treatment. Furthermore, in response to SMX treatment, the family Nitrosomonadaceae appeared to be dominant. Pseudomonas was the most dominating bacterial genus in A-EBD whereas Cupriavidus dominated in sample B-EBD. Additionally, the sulfur oxidizing bacteria were enriched in the B-EBD sample, signifying efficient electron transfer and hence organic molecule degradation in the e-SAT system. Results of this study offer new insights into understanding of microbial community shift during the biodegradation of SMX.

  6. A 6U CubeSat Constellation for Atmospheric Temperature and Humidity Sounding

    Science.gov (United States)

    Padmanabhan, Sharmila; Brown, Shannon; Kangaslahti, Pekka; Cofield, Richard; Russell, Damon; Stachnik, Robert; Steinkraus, Joel; Lim, Boon

    2013-01-01

    We are currently developing a 118/183 GHz sensor that will enable observations of temperature and precipitation profiles over land and ocean. The 118/183 GHz system is well suited for a CubeSat deployment as 10cm antenna aperture provides sufficiently small footprint sizes (is approx. 25km). This project will enable low cost, compact radiometer instrumentation at 118 and 183 GHz that would fit in a 6U CubeSat with the objective of mass-producing this design to enable a suite of small satellites to image the key geophysical parameters that are needed to improve prediction of extreme weather events. We will take advantage of past and current technology developments at JPL viz. HAMSR (High Altitude Microwave Scanning Radiometer), Advanced Component Technology (ACT'08) to enable low-mass and low-power high frequency airborne radiometers. The 35 nm InP enabling technology provides significant reduction in power consumption (Low Noise Amplifier + Mixer Block consumes 24 mW). In this paper, we will describe the design and implementation of the 118 GHz temperature sounder and 183 GHz humidity sounder instrument on the 6U CubeSat. In addition, a summary of radiometer calibration and retrieval techniques of the temperature and humidity will be discussed. The successful demonstration of this instrument on the 6U CubeSat would pave the way for the development of a constellation consisting of suite of these instruments. The proposed constellation of these 6U CubeSat radiometers would allow sampling of tropospheric temperature and humidity with fine temporal (on the order of minutes) and spatial resolution (is approx. 25 km).

  7. Sat, the secreted autotransporter toxin of uropathogenic Escherichia coli, is a vacuolating cytotoxin for bladder and kidney epithelial cells.

    Science.gov (United States)

    Guyer, Debra M; Radulovic, Suzana; Jones, Faye-Ellen; Mobley, Harry L T

    2002-08-01

    The secreted autotransporter toxin (Sat) of uropathogenic Escherichia coli exhibits cytopathic activity upon incubation with HEp-2 cells. We further investigated the effects of Sat on cell lines more relevant to the urinary tract, namely, those derived from bladder and kidney epithelium. Sat elicited elongation of cells and apparent loosening of cellular junctions upon incubation with Vero kidney cells. Additionally, incubation with Sat triggered significant vacuolation within the cytoplasm of both human bladder (CRL-1749) and kidney (CRL-1573) cell lines. This activity has been associated with only a few other known toxins. Following transurethral infection of CBA mice with a sat mutant, no reduction of CFU in urine, bladder, or kidney tissue was seen compared to that in mice infected with wild-type E. coli CFT073. However, significant histological changes were observed within the kidneys of mice infected with wild-type E. coli CFT073, including dissolution of the glomerular membrane and vacuolation of proximal tubule cells. Such damage was not observed in kidney sections of mice infected with a Sat-deficient mutant. These results indicate that Sat, a vacuolating cytotoxin expressed by uropathogenic E. coli CFT073, elicits defined damage to kidney epithelium during upper urinary tract infection and thus contributes to pathogenesis of urinary tract infection.

  8. Higher spin gauge theories

    CERN Document Server

    Henneaux, Marc; Vasiliev, Mikhail A

    2017-01-01

    Symmetries play a fundamental role in physics. Non-Abelian gauge symmetries are the symmetries behind theories for massless spin-1 particles, while the reparametrization symmetry is behind Einstein's gravity theory for massless spin-2 particles. In supersymmetric theories these particles can be connected also to massless fermionic particles. Does Nature stop at spin-2 or can there also be massless higher spin theories. In the past strong indications have been given that such theories do not exist. However, in recent times ways to evade those constraints have been found and higher spin gauge theories have been constructed. With the advent of the AdS/CFT duality correspondence even stronger indications have been given that higher spin gauge theories play an important role in fundamental physics. All these issues were discussed at an international workshop in Singapore in November 2015 where the leading scientists in the field participated. This volume presents an up-to-date, detailed overview of the theories i...

  9. Captura de satélites durante a formação de Júpiter

    Science.gov (United States)

    Winter, O. C.; Vieira Neto, E.; Yokoyama, T.

    2003-08-01

    O planeta Jupiter apresenta um grande número de satélites irregulares. As características das órbitas destes objetos indicam que os mesmos não teriam se formado ao redor do planeta que se encontram. As teorias existentes são de que estes objetos teriam se formado em uma região distante do planeta e sua evolução dinâmica os teria levado a uma captura gravitacional pelo planeta. Tendo em vista que o processo de captura gravitacional sem efeitos dissipativos não produz uma captura permanente, estudamos o processo de captura durante o estágio de formação do planeta. Realizamos simulações numéricas para os casos de satélites prógrados e retrógrados que inicialmente se encontram ao redor de Jupiter com sua massa atual e então, evoluimos a integração voltando no tempo de modo que o planeta sofra uma redução em sua massa (de 100% para 10% de sua massa atual) e verificamos o instante em que o satélites escapa do planeta (quando sua energia do problema de dois corpos se torna positiva). Assim, analisando o problema inverso no tempo, obtivemos em qual estágio de formação de Jupiter aquele hipotético satélite teria sido capturado. Os resultados mostram que os satélites retrógrados são capturados assim que entram na região delimitada pela esfera de Hill do planeta, enquanto que os satélites prógrados só são capturados quando entram numa região bem mais próxima ao planeta, uma fração da esfera de Hill.

  10. MERRA IAU 2d surface and TOA radiation fluxes subsetted along CloudSat track V5.2.0

    Data.gov (United States)

    National Aeronautics and Space Administration — This is the MERRA IAU 2d surface and TOA radiation fluxes subset, collocated with the CloudSat track. The subset is processed at the Modeling and Assimilation Data...

  11. MERRA IAU 3d assimilated state on pressure subsetted along CloudSat track V5.2.0

    Data.gov (United States)

    National Aeronautics and Space Administration — This is the MERRA IAU 3d assimilated state on pressure subset, collocated with the CloudSat track. The subset is processed at the Modeling and Assimilation Data and...

  12. MERRA IAU 2d atmospheric single-level diagnostics subsetted along CloudSat track V5.2.0

    Data.gov (United States)

    National Aeronautics and Space Administration — This is the MERRA IAU 2d atmospheric single-level diagnostics subset, collocated with the CloudSat track. The subset is processed at the Modeling and Assimilation...

  13. MERRA IAU 3d cloud diagnostics subsetted along CloudSat track V5.2.0

    Data.gov (United States)

    National Aeronautics and Space Administration — This is the MERRA IAU 3d cloud diagnostics subset, collocated with the CloudSat track. The subset is processed at the Modeling and Assimilation Data and Information...

  14. The secreted autotransporter toxin (Sat) does not act as a virulence factor in the probiotic Escherichia coli strain Nissle 1917.

    Science.gov (United States)

    Toloza, Lorena; Giménez, Rosa; Fábrega, María Jose; Alvarez, Carina Shianya; Aguilera, Laura; Cañas, María Alexandra; Martín-Venegas, Raquel; Badia, Josefa; Baldomà, Laura

    2015-10-30

    Escherichia coli Nissle 1917 (EcN) is a probiotic used in the treatment of intestinal diseases. Although it is considered safe, EcN is closely related to the uropathogenic E. coli strain CFT073 and contains many of its predicted virulence elements. Thus, it is relevant to assess whether virulence-associated genes are functional in EcN. One of these genes encodes the secreted autotransporter toxin (Sat), a member of the serine protease autotransporters of Enterobacteriaceae (SPATEs) that are secreted following the type V autotransporter pathway. Sat is highly prevalent in certain E. coli pathogenic groups responsible for urinary and intestinal infections. In these pathogens Sat promotes cytotoxic effects in several lines of undifferentiated epithelial cells, but not in differentiated Caco-2 cells. Here we provide evidence that sat is expressed by EcN during the colonization of mouse intestine. The EcN protein is secreted as an active serine protease, with its 107 kDa-passenger domain released into the medium as a soluble protein. Expression of recombinant EcN Sat protein in strain HB101 increases paracellular permeability to mannitol in polarized Caco-2 monolayers. This effect, also reported for the Sat protein of diffusely adherent E. coli, is not observed when this protein is expressed in the EcN background. In addition, we show that EcN supernatants confer protection against Sat-mediated effects on paracellular permeability, thus indicating that other secreted EcN factors are able to prevent barrier disruption caused by pathogen-related factors. Sat is not required for intestinal colonization, but the EcNsat::cat mutant outcompetes wild-type EcN in the streptomycin-treated mouse model. Analysis of the presence of sat in 29 strains of the ECOR collection isolated from stools of healthy humans shows 34.8 % positives, with high prevalence of strains of the phylogenetic groups D and B2, related with extra-intestinal infections. Sat does not act as a virulence factor

  15. In Bacillus subtilis, the SatA (Formerly YyaR) Acetyltransferase Detoxifies Streptothricin via Lysine Acetylation.

    Science.gov (United States)

    Burckhardt, Rachel M; Escalante-Semerena, Jorge C

    2017-11-01

    Soil is a complex niche, where survival of microorganisms is at risk due to the presence of antimicrobial agents. Many microbes chemically modify cytotoxic compounds to block their deleterious effects. Streptothricin is a broad-spectrum antibiotic produced by streptomycetes that affects Gram-positive and Gram-negative bacteria alike. Here we identify the SatA (for s treptothricin a ce t yltransferase A , formerly YyaR) enzyme of Bacillus subtilis as the mechanism used by this soil bacterium to detoxify streptothricin. B. subtilis strains lacking satA were susceptible to streptothricin. Ectopic expression of satA + restored streptothricin resistance to B. subtilis satA ( Bs SatA) strains. Purified Bs SatA acetylated streptothricin in vitro at the expense of acetyl-coenzyme A (acetyl-CoA). A single acetyl moiety transferred onto streptothricin by SatA blocked the toxic effects of the antibiotic. SatA bound streptothricin with high affinity ( K d [dissociation constant] = 1 μM), and did not bind acetyl-CoA in the absence of streptothricin. Expression of B. subtilis satA + in Salmonella enterica conferred streptothricin resistance, indicating that SatA was necessary and sufficient to detoxify streptothricin. Using this heterologous system, we showed that the SatA homologue from Bacillus anthracis also had streptothricin acetyltransferase activity. Our data highlight the physiological relevance of lysine acetylation for the survival of B. subtilis in the soil. IMPORTANCE Experimental support is provided for the functional assignment of gene products of the soil-dwelling bacilli Bacillus subtilis and Bacillus anthracis This study focuses on one enzyme that is necessary and sufficient to block the cytotoxic effects of a common soil antibiotic. The enzyme alluded to is a member of a family of proteins that are broadly distributed in all domains of life but poorly studied in B. subtilis and B. anthracis The initial characterization of the enzyme provides insights into its

  16. Convective overshooting top detection with MSG SEVIRI, Himawari-8 AHI, and CloudSat CPR data

    Science.gov (United States)

    Im, J.; Kim, M.; Park, S.

    2015-12-01

    Overshooting Tops (OTs) are the clouds that penetrate into the tropopause and grow to the bottom of stratosphere at the top layer of cumulonimbus with very strong updraft. Severe weather conditions such as ground lightning, large hail, strong winds, and heavy rainfall can cause in the cumulonimbus clouds with OTs, with turbulence and lightning occurring very frequently in the area near OTs. In terms of aviation operations, OTs are a very important risk factor. According to Federal Aviation Administration, 509 cases of 4,326 weather-related events from 1992 to 2001were caused by turbulences. The detection of OTs is important to predict the degree and location of severe weather conditions such as turbulence, lightning, and thunderstorms. There are two methods widely used to detect OTs with multispectral images. One is the Water Vapor-InfraRed window channel Brightness Temperature Difference (WV-IRW BTD), which uses the differences in brightness temperatures at an infrared channel (about 11 ㎛). The other approach is the InfraRed Window texture (IRW-texture) method, which is based on the characteristics of OTs that appear a pixel group with low temperatures. The typical IRW-texture algorithm uses simple thresholds to detect OTs, whereas this research proposes an advanced approach based on machine learning techniques such as decision trees, random forest (RF), and support vector machines (SVM) with various variables from geostationary satellite data such as MSG SEVIRI (over Africa) and Himawari AHI (over East Asia) so as to improve the detection of OTs. OT and non-OT samples (e.g. other types of clouds such as stratus and cirrus) were extracted using the CloudSat cloud profiling radar (CPR) and SEVIRI (and Himawari) imagery. Results show that RF produced the best performance in detection of OTs yielding an overall accuracy of 98.33% and a false alarm rate of 9.01%. The user's accuracies of OT and non-OT were similar, whereas the producer's accuracy of non-OT was

  17. Under conditions of large geometric miss, tumor control probability can be higher for static gantry intensity-modulated radiation therapy compared to volume-modulated arc therapy for prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Balderson, Michael, E-mail: michael.balderson@rmp.uhn.ca; Brown, Derek; Johnson, Patricia; Kirkby, Charles

    2016-07-01

    The purpose of this work was to compare static gantry intensity-modulated radiation therapy (IMRT) with volume-modulated arc therapy (VMAT) in terms of tumor control probability (TCP) under scenarios involving large geometric misses, i.e., those beyond what are accounted for when margin expansion is determined. Using a planning approach typical for these treatments, a linear-quadratic–based model for TCP was used to compare mean TCP values for a population of patients who experiences a geometric miss (i.e., systematic and random shifts of the clinical target volume within the planning target dose distribution). A Monte Carlo approach was used to account for the different biological sensitivities of a population of patients. Interestingly, for errors consisting of coplanar systematic target volume offsets and three-dimensional random offsets, static gantry IMRT appears to offer an advantage over VMAT in that larger shift errors are tolerated for the same mean TCP. For example, under the conditions simulated, erroneous systematic shifts of 15 mm directly between or directly into static gantry IMRT fields result in mean TCP values between 96% and 98%, whereas the same errors on VMAT plans result in mean TCP values between 45% and 74%. Random geometric shifts of the target volume were characterized using normal distributions in each Cartesian dimension. When the standard deviations were doubled from those values assumed in the derivation of the treatment margins, our model showed a 7% drop in mean TCP for the static gantry IMRT plans but a 20% drop in TCP for the VMAT plans. Although adding a margin for error to a clinical target volume is perhaps the best approach to account for expected geometric misses, this work suggests that static gantry IMRT may offer a treatment that is more tolerant to geometric miss errors than VMAT.

  18. Sustained attention in mice: expanding the translational utility of the SAT by incorporating the Michigan Controlled Access Response Port (MICARP).

    Science.gov (United States)

    St Peters, Megan; Cherian, Ajeesh Koshy; Bradshaw, Marc; Sarter, Martin

    2011-12-01

    Advances in mouse genetic technology have spurred increasing interest in the development of cognitive tasks for mice. Here, we describe and discuss the modifications necessary to adapt a task for the assessment of sustained attention performance for use in mice, including for taxing the top-down control of such performance. The validity of the Sustained Attention Task (SAT), including the distractor version (dSAT), has previously been demonstrated in rats and humans. This task requires moveable or retractable operanda; insertion of operanda into the operant chambers cues animals to respond to a prior signal or non-signal event, reporting either a hit or a miss, or a correct rejection or false alarm, respectively. Retractable levers did not support sufficiently high and stable levels of performance in mice. Given the widespread use of static nose-poke devices for testing operant performance in mice, we therefore designed and fabricated a retractable nose-poke device. As this device extends into chambers, a hole for nose-poking is slowly opened and closed again as the device retracts (termed the "Michigan Controlled Access Response Port", MICARP). Results describe the effects of variation of signal duration and event rate, trial outcome and trial type probability, effects of mice deprivation levels, and the reliability of SAT and dSAT performance. Mice perform the SAT and dSAT at levels comparable to those observed in rats. This task will be of assistance in expanding the translational usefulness of the SAT and dSAT. Copyright © 2011 Elsevier B.V. All rights reserved.

  19. CryoVEx 2011-12 Airborne Campaigns for CryoSat Validation

    DEFF Research Database (Denmark)

    Skourup, Henriette; Hvidegaard, Sine Munk; Forsberg, René

    2013-01-01

    by comparing the radar and laser measurements, as the laser reflects on the surface, and by overflights of radar reflectors. The campaigns focused on five main validation sites: Devon ice cap (Canada), Austfonna ice cap (Svalbard), the EGIG line crossing the Greenland Ice Sheet, as well as the sea ice north...... 2003. To validate the performance of the CryoSat-2 radar altimeter (SIRAL), the aircraft is equipped with an airborne version of the SIRAL altimeter (ASIRAS) together with a laser scanner. Of particular interest is to study the penetration depth of SIRAL into both land- and sea ice. This can be done...... of Alert and sea ice around Svalbard in the Fram Strait. Selected tracks were planned to match CryoSat-2 passes and a few of them were flown in formation flight with the AlfredWegener Institute (AWI) Polar- 5 carrying an EM induction sounder. The paper presents an overview of the 2011-12 airborne campaigns...

  20. Non Uniform Selection of Solutions for Upper Bounding the 3-SAT Threshold

    CERN Document Server

    Hugel, Thomas

    2010-01-01

    We give a new insight into the upper bounding of the 3-SAT threshold by the first moment method. The best criteria developed so far to select the solutions to be counted discriminate among neighboring solutions on the basis of uniform information about each individual free variable. What we mean by uniform information, is information which does not depend on the solution: e.g. the number of positive/negative occurrences of the considered variable. What is new in our approach is that we use non uniform information about variables. Thus we are able to make a more precise tuning, resulting in a slight improvement on upper bounding the 3-SAT threshold for various models of formulas defined by their distributions.

  1. The NUTS CubeSat Project: Spin-Offs and Technology Development

    Science.gov (United States)

    Birkeland, R.; Stein, T. A.; Tommer, M.; Beermann, B.; Petrasch, J.; Gjersvik, A.

    2015-09-01

    The development of CubeSats allows for the conception and implementation of new approaches and technologies. In this paper we present a spin-off and technology innovation resulting from the NTNU Test Satellite (NUTS). NUTS is a 2U CubeSat under development by students of the Norwegian University of Science and Technology (NTNU) in Trondheim, Norway. The satellite is due to launch in 2017 and is based upon in-house developments. We will describe the innovative carbon-fibre frame, radio systems and proposals for an infrared camera for atmospheric gravity waves observations. A NUTS spinoff, the Cosmic Particle Telescope (CPT-SCOPE), will be presented in greater detail since it has been selected for the BEXUS 20 campaign in autumn 2015. CPT-SCOPE is a Norwegian-German compact radiation monitor prototype developed by students.

  2. Performance evaluation of supervised change detection tool on DubaiSat-2 multispectral and pansharp images

    Science.gov (United States)

    Almatroushi, Hessa R.

    2014-10-01

    Supervised Change Detection Tool (SCDT) is an in-house developed tool in Emirates Institution for Advanced Science and Technology (EIAST). The developed tool is based on Algebra Change Detection algorithm and multi-class Support Vector Machine classifier and is capable of highlighting the areas of change, describing them, and discarding any falsedetections that result from shadow. Further, it can collect the analysis results, which include the change of class an area went through and the overall change percentage of each class defined, in a Microsoft Word document automatically. This paper evaluates the performance of the SCDT, which was initially developed for DubaiSat-1 multispectral images, on DubaiSat-2 multispectral and pansharp images. Moreover, it compares its performance opposed to Change Detection Analysis (i.e. Post-Classification) in ENVI.

  3. Antarctic Grounding Line Mapping From CryoSat-2 Radar Altimetry

    Science.gov (United States)

    Dawson, G. J.; Bamber, J. L.

    2017-12-01

    We present a new technique for mapping the grounding line of Antarctic ice shelves using a combination of CryoSat-2 standard and swath elevation data. Our method is based on detecting the tidal signal in pseudo crossovers and is tested on the Siple Coast region of West Antarctica. The mapped grounding line is in good agreement with previous observations from differential SAR interferometry and from ICESat repeat tracks, with a standard deviation of 1.1 km and 1.0 km, respectively, between these methods and ours. There is, however, an average seaward bias of 0.6 km, which is due to the poorer precision of CryoSat-2. We have improved coverage particularly near the Echelmeyer Ice Stream where we have shown that the grounding zone is approximately 25 km inland from previous estimates. This new method is computationally efficient and can be applied to the rest of Antarctica.

  4. Receptor de señales APT de satélites meteorológicos

    OpenAIRE

    Ciafardini, Juan Pablo

    2010-01-01

    La Administración Nacional Oceánica y Atmosférica de EE.UU. (NOAA) dispone de 4 satélites que orbitan la tierra y transmiten datos en tiempo real de parámetros atmosféricos y climáticos que se pueden capturar con un equipo receptor adecuado y métodos de procesamiento. La transmisión de los datos a tierra se realiza mediante el sistema APT (Automatic Picture Transmission). Este es un sistema sencillo y robusto que permite a cualquier estación de tierra recibir la comunicación del satélite ...

  5. The spiral aftereffect technique (SAT) can differentiate between depressive and somatoform disorder patients.

    Science.gov (United States)

    Olsson, Lars

    2014-04-01

    This study examined how differences in visuo-perceptual patterns are related to psychopathology. Fifty-six patients (37 women, 19 men; M age = 43.8 yr., SD = 13.4) with a main diagnosis of unipolar depression and 42 patients (22 women, 20 men; M age = 42.0 yr., SD = 11.1) with a main diagnosis of somatoform disorder were compared. The duration and trend of a visual motion aftereffect were measured with the Spiral Aftereffect Technique (SAT). The results indicated that successively increasing aftereffect durations characterized the depressive patients, whereas patterns of very short or short final aftereffect preceded by successively decreasing aftereffect durations characterized the patients with a somatoform disorder. The SAT is thus a valuable tool for linking objectively measured perceptual-personality characteristics with some mental disorders.

  6. The Iodine Satellite (iSAT) Hall Thruster Demonstration Mission Concept and Development

    Science.gov (United States)

    Dankanich, John W.; Polzin, Kurt A.; Calvert, Derek; Kamhawi, Hani

    2014-01-01

    The use of iodine propellant for Hall thrusters has been studied and proposed by multiple organizations due to the potential mission benefits over xenon. In 2013, NASA Marshall Space Flight Center competitively selected a project for the maturation of an iodine flight operational feed system through the Technology Investment Program. Multiple partnerships and collaborations have allowed the team to expand the scope to include additional mission concept development and risk reduction to support a flight system demonstration, the iodine Satellite (iSAT). The iSAT project was initiated and is progressing towards a technology demonstration mission preliminary design review. The current status of the mission concept development and risk reduction efforts in support of this project is presented.

  7. CryoSat-2 satellite radar altimetry for river analysis and modelling

    DEFF Research Database (Denmark)

    Schneider, Raphael

    from previous and current satellite altimetry missions, which are in short-repeat orbits with cycles of 10 to 35 days. The orbit configuration of CryoSat-2 is a challenge for hydrologic applications. Short-repeat missions allow deriving time series at locations where the satellite ground track......The global coverage of in situ observations of surface water dynamics is insufficient to effectively manage water resources. Moreover, the availability of these data is decreasing, due to the lack of gauging stations and data sharing. Satellite radar altimetry, initially developed to monitor ocean...... water levels, also offers measurements of water levels of rivers and lakes on a global scale. Because of the continuous upstart of new missions, and sensor and processing innovations, the importance of satellite altimetry data for the hydrologic community is increasing. CryoSat-2, launched...

  8. Sistema Planeta-Satélite. Simulación orbital y potenciales gravitatorios

    Science.gov (United States)

    Medina, C.; Carrillo, M.

    Se presenta un programa (desarrollado en Quick Basic 4.5) que simula, en tres dimensiones, el movimiento orbital de un satélite (o luna) alrededor de un planeta, al tiempo que calcula y grafica, en un plano, el potencial gravitatorio del sistema en función de la distancia al planeta. Para la simulación orbital, se emplea la matriz de transformación entre el sistema del planeta y el plano orbital. Para el cálculo y graficación del potencial se aplica un desarrollo en serie hasta el segundo orden, que da cuenta del efecto de achatamiento de los polos, en caso de que éste exista. Las longitudes de los ejes del planeta, la masa de éste y del satélite, sus tamaños aparentes, y los parámetros orbitales son introducidos por el usuario.

  9. A SAT-Based Analysis of a Calculus for Wireless Sensor Networks

    DEFF Research Database (Denmark)

    Wu, Xi; Nielson, Hanne Riis; Zhu, Huibiao

    2015-01-01

    In viewing the common unreliability problem in wireless communications, the CWQ calculus (a Calculus for Wireless sensor networks from Quality perspective) was recently proposed for modeling and reasoning about WSNs(Wireless Sensor Networks) and their applications from a quality perspective...... of the whole network. Finally, we give a real-world case study with the scenario of refueling a car to demonstrate the applicability of the extended calculus and the SAT-based analysis....

  10. The integrated satellite-acoustic telemetry (iSAT) system for tracking marine megafauna

    KAUST Repository

    De la Torre, Pedro

    2012-10-06

    This document describes the integrated satellite-acoustic telemetry (iSAT) system: an autonomous modular system for tracking the movements of large pelagic fish using acoustic telemetry and satellite communications. The sensor platform is described along with the propulsion and navigation systems. An application for tracking the whale shark (Rhincodon typus) in the Red Sea is included along with a discussion of the technical difficulties that such a system faces.

  11. CanSat Competition: Contributing to the Development of NASA's Vision for Robotic Space Exploration

    Science.gov (United States)

    Berman, Joshua; Berman, Timothy; Billheimer, Thomas; Biclmer. Elizabeth; Hood, Stuart; Neas, Charles

    2007-01-01

    CanSat is an international student design-build-launch competition organized by the American Astronautical Society (AAS) and American Institute of Aeronautics and Astronautics (AIAA). The competition is also sponsored by the Naval Research Laboratory (NRL) and the National Aeronautics and Space Administration (NASA). The CanSat competition is designed for college, university and high school students wanting to participate in an applicable space-related competition. The objective of the CanSat competition is to complete space exploration missions by designing a specific system for a small sounding rocket payload which will follow and perform to a specific set of rules and guidelines for each year's competition. The competition encompasses a complete life-cycle of one year which includes all phases of design, integration, testing, judging and competition. The mission guidelines are based from space exploration missions and include bonus requirement options which teams may choose to participate in. The fundamental goal of the competition is to educate future engineers and scientists. This is accomplished by students applying systems engineering practices to a development project that incorporates an end-to-end life cycle, from requirements analysis, through preliminary design, integration and testing, an actual flight of the CanSat, and concluding with a post-mission debrief. This is done specifically with space related missions to bring a unique aspect of engineering and design to the competition. The competition has been progressing since its creation in 2005. The competition was originally meant to purely convey the engineering and design process to its participants, but through many experiences the competition has also undergone a learning experience with respect to systems engineering process and design. According

  12. An Overview of the NASA/Science Mission Directorate CubeSat Activities

    OpenAIRE

    Moses, J. Daniel; Pierce, David L.; Seablom, Michael S.; Petro, Andrew J.

    2016-01-01

    These are amazing times of space and Earth science discovery related to the Earth system, our Sun, the planets, and the universe. The National Aeronautics and Space Administration (NASA) Science Mission Directorate (SMD) provides CubeSats as a component part of the NASA’s science and technology programs to conduct important scientific and technology investigations, while also providing crucial hands-on training opportunities for students to participate in research. SMD, working with NASA’s Sp...

  13. Early In-orbit Performance of Scanning Sky Monitor Onboard AstroSat

    Indian Academy of Sciences (India)

    M. C. Ramadevi

    E-mail: ramadevi@isac.gov.in; mc.ramadevi@gmail.com. MS received 23 December 2016; accepted 9 May 2017; published online 19 June 2017. Abstract. We report the in-orbit performance of Scanning Sky Monitor (SSM) onboard AstroSat. The SSM operates in the energy range 2.5 to 10 keV and scans the sky to detect ...

  14. Application of CryoSat-2 altimetry data for river analysis and modelling

    Science.gov (United States)

    Schneider, Raphael; Nygaard Godiksen, Peter; Villadsen, Heidi; Madsen, Henrik; Bauer-Gottwein, Peter

    2017-02-01

    Availability of in situ river monitoring data, especially of data shared across boundaries, is decreasing, despite growing challenges for water resource management across the entire globe. This is especially valid for the case study of this work, the Brahmaputra Basin in South Asia. Commonly, satellite altimeters are used in various ways to provide information about such river basins. Most missions provide virtual station time series of water levels at locations where their repeat orbits cross rivers. CryoSat-2 is equipped with a new type of altimeter, providing estimates of the actual ground location seen in the reflected signal. It also uses a drifting orbit, challenging conventional ways of processing altimetry data to river water levels and their incorporation in hydrologic-hydrodynamic models. However, CryoSat-2 altimetry data provides an unprecedentedly high spatial resolution. This paper suggests a procedure to (i) filter CryoSat-2 observations over rivers to extract water-level profiles along the river, and (ii) use this information in combination with a hydrologic-hydrodynamic model to fit the simulated water levels with an accuracy that cannot be reached using information from globally available digital elevation models (DEMs) such as from the Shuttle Radar Topography Mission (SRTM) only. The filtering was done based on dynamic river masks extracted from Landsat imagery, providing spatial and temporal resolutions high enough to map the braided river channels and their dynamic morphology. This allowed extraction of river water levels over previously unmonitored narrow stretches of the river. In the Assam Valley section of the Brahmaputra River, CryoSat-2 data and Envisat virtual station data were combined to calibrate cross sections in a 1-D hydrodynamic model of the river. The hydrologic-hydrodynamic model setup and calibration are almost exclusively based on openly available remote sensing data and other global data sources, ensuring transferability of

  15. Updating Human Capital Decisions: Evidence from SAT Score Shocks and College Applications

    OpenAIRE

    Timothy N. Bond; Bulman, George; Li, Xiaoxiao; Smith, Jonathan

    2016-01-01

    We estimate whether students update their collegepplication portfolios in response to large, unanticipated information shocks generated by the release of SAT scores -- a primary component of admissions decisions. Exploiting new population data on the timing of college selection and a policy that induces students to choose colleges prior to taking exam, we find that the release of scores causes students to update their portfolios in terms of selectivity, tuition, and sector. However, the magni...

  16. Optimizing an Infrared Camera for Observing Atmospheric Gravity Waves from a CubeSat Platform

    OpenAIRE

    Rønning, Snorre Stavik

    2012-01-01

    The NTNU Test Satellite (NUTS) is a double CubeSat deigned by master students at NTNU. The goal of the project is to image atmospheric gravity waves in the OH airglow layer. This thesis explores the theory behind gravity waves and discuss the design of an infrared camera as a payload onboard. Different requirement based on scientific and mechanical limitations are presented. Based on this a suitable infrared camera is presented.

  17. SkySat-1: very high-resolution imagery from a small satellite

    Science.gov (United States)

    Murthy, Kiran; Shearn, Michael; Smiley, Byron D.; Chau, Alexandra H.; Levine, Josh; Robinson, M. Dirk

    2014-10-01

    This paper presents details of the SkySat-1 mission, which is the first microsatellite-class commercial earth- observation system to generate sub-meter resolution panchromatic imagery, in addition to sub-meter resolution 4-band pan-sharpened imagery. SkySat-1 was built and launched for an order of magnitude lower cost than similarly performing missions. The low-cost design enables the deployment of a large imaging constellation that can provide imagery with both high temporal resolution and high spatial resolution. One key enabler of the SkySat-1 mission was simplifying the spacecraft design and instead relying on ground- based image processing to achieve high-performance at the system level. The imaging instrument consists of a custom-designed high-quality optical telescope and commercially-available high frame rate CMOS image sen- sors. While each individually captured raw image frame shows moderate quality, ground-based image processing algorithms improve the raw data by combining data from multiple frames to boost image signal-to-noise ratio (SNR) and decrease the ground sample distance (GSD) in a process Skybox calls "digital TDI". Careful qual-ity assessment and tuning of the spacecraft, payload, and algorithms was necessary to generate high-quality panchromatic, multispectral, and pan-sharpened imagery. Furthermore, the framing sensor configuration en- abled the first commercial High-Definition full-frame rate panchromatic video to be captured from space, with approximately 1 meter ground sample distance. Details of the SkySat-1 imaging instrument and ground-based image processing system are presented, as well as an overview of the work involved with calibrating and validating the system. Examples of raw and processed imagery are shown, and the raw imagery is compared to pre-launch simulated imagery used to tune the image processing algorithms.

  18. Sat1 is dispensable for active oxalate secretion in mouse duodenum

    OpenAIRE

    Ko, Narae; Knauf, Felix; Jiang, Zhirong; Markovich, Daniel; Aronson, Peter S.

    2012-01-01

    Mice deficient for the apical membrane oxalate transporter SLC26A6 develop hyperoxalemia, hyperoxaluria, and calcium oxalate stones due to a defect in intestinal oxalate secretion. However, the nature of the basolateral membrane oxalate transport process that operates in series with SLC26A6 to mediate active oxalate secretion in the intestine remains unknown. Sulfate anion transporter-1 (Sat1 or SLC26A1) is a basolateral membrane anion exchanger that mediates intestinal oxalate transport. Mor...

  19. A data assimilation system combining CryoSat-2 data and hydrodynamic river models

    Science.gov (United States)

    Schneider, Raphael; Ridler, Marc-Etienne; Godiksen, Peter Nygaard; Madsen, Henrik; Bauer-Gottwein, Peter

    2018-02-01

    There are numerous hydrologic studies using satellite altimetry data from repeat-orbit missions such as Envisat or Jason over rivers. This study is one of the first examples for the combination of altimetry from drifting-ground track satellite missions, namely CryoSat-2, with a river model. CryoSat-2 SARIn Level 2 data is used to improve a 1D hydrodynamic model of the Brahmaputra River in South Asia, which is based on the Saint-Venant equations for unsteady flow and set up in the MIKE HYDRO River software. After calibration of discharge and water level the hydrodynamic model can accurately and bias-free represent the spatio-temporal variations of water levels. A data assimilation framework has been developed and linked with the model. It is a flexible framework that can assimilate water level data which are arbitrarily distributed in time and space. The setup has been used to assimilate CryoSat-2 water level observations over the Assam valley for the years 2010-2015, using an Ensemble Transform Kalman Filter (ETKF). Performance improvement in terms of discharge forecasting skill was then evaluated. For experiments with synthetic CryoSat-2 data the continuous ranked probability score (CRPS) was improved by up to 32%, whilst for experiments assimilating real data it could be improved by up to 10%. The developed methods are expected to be transferable to other rivers and altimeter missions. The model setup and calibration is based almost entirely on globally available remote sensing data.

  20. SAT-LAB: A MATLAB Graphical User Interface for simulating and visualizing Keplerian satellite orbits

    Science.gov (United States)

    Piretzidis, Dimitrios; Sideris, Michael G.

    2017-04-01

    SAT-LAB is a MATLAB-based Graphical User Interface (GUI), developed for simulating and visualizing satellite orbits. The primary purpose of SAT-LAB is to provide software with a user-friendly interface that can be used for both academic and scientific purposes. For the simulation of satellite orbits, a simple Keplerian propagator is used. The user can select the six Keplerian elements, and the simulation and visualization of the satellite orbit is performed simultaneously, in real time. The satellite orbit and the state vector, i.e., satellite position and velocity, at each epoch is given in the Inertial Reference Frame (IRF) and the Earth-Fixed Reference Frame (EFRF). For the EFRF, both the 3D Cartesian coordinates and the ground tracks of the orbit are provided. Other visualization options include selection of the appearance of the Earth's coastline and topography/bathymetry, the satellite orbit, position, velocity and radial distance, and the IRF and EFRF axes. SAT-LAB is also capable of predicting and visualizing orbits of operational satellites. The software provides the ability to download orbital elements and other information of operational satellites in the form of Two-Line Element sets. The user can choose among 41 satellite categories, including geodetic, communications, navigation, and weather satellites, as well as space debris from past satellite missions or collisions. Real-time tracking of the position of operational satellites is also available. All the capabilities of SAT-LAB software are demonstrated by providing simulation examples of geostationary, highly elliptical and near polar orbits. Also, visualization examples of operational satellite orbits, such as GNSS and LEO satellites, are given.

  1. SIRAL 2 on CryoSat-2 First Results in Orbit

    Science.gov (United States)

    Rey, L.; Rys, L.; Cullen, R.

    2010-12-01

    CryoSat 2 has last now 2 month in operation. SIRAL 2 on board, the radar altimeter / interferometer, is tested in all the configurations it will have to operate after the current 6 month commissioning phase leading to deliver the topographic data to the scientific community. The present paper analyses the results during this first period concentrated on the instrument behaviour and performance obtained.

  2. The Australian Space Eye: studying the history of galaxy formation with a CubeSat

    OpenAIRE

    Horton, Anthony; Spitler, Lee; Mathers, Naomi; Petkovic, Michael; Griffin, Douglas; Barraclough, Simon; Benson, Craig; Dimitrijevic, Igor; Lambert, Andrew; Previte, Anthony; Bowen, John; Westerman, Solomon; Puig-Suari, Jordi; Reisenfeld, Sam; Lawrence, Jon

    2016-01-01

    The Australian Space Eye is a proposed astronomical telescope based on a 6U CubeSat platform. The Space Eye will exploit the low level of systematic errors achievable with a small space based telescope to enable high accuracy measurements of the optical extragalactic background light and low surface brightness emission around nearby galaxies. This project is also a demonstrator for several technologies with general applicability to astronomical observations from nanosatellites. Space Eye is b...

  3. The implementation of the South African Triage Score (SATS in an urban teaching hospital, Ghana

    Directory of Open Access Journals (Sweden)

    Sarah Rominski

    2014-06-01

    Conclusion: Under-triage is a concern to patient care and safety, and while the under-triage rate of 5.7% in this sample falls within the 5–10% range considered unavoidable by the American College of Surgeons Committee on Trauma, concentrated efforts to regularly train triage nurses to ensure no patients are under-triaged have been undertaken. Overall though, SATS has been implemented successfully in the EC at KATH by triage nurses.

  4. Comparing IceBridge and CryoSat-2 sea ice observations over the Arctic and the Southern Ocean

    Science.gov (United States)

    Yi, D.; Kurtz, N. T.; Harbeck, J.; Hofton, M. A.; Manizade, S.; Cornejo, H.

    2016-12-01

    From 2009 to 2015, CryoSat-2 and IceBridge had 34 coincident lines over sea ice, 23 over the Arctic (20 with ATM, 2 with LVIS, and 1 with both ATM and LVIS) and 11 over the Southern Ocean (9 with ATM and 2 with both ATM and LVIS). In this study, we will compare both surface elevation and sea ice freeboard from CryoSat-2, ATM, and LVIS. We will apply identical ellipsoid, geoid, tide models, and atmospheric corrections to CryoSat-2, ATM, and LVIS data. For CryoSat-2, we will use surface elevation and sea ice freeboard both in the standard CryoSat-2 data product and calculated through a waveform fitting method. For ATM and LVIS, we will use surface elevation and sea ice freeboard in the OIB data product and the elevation and sea ice freeboard calculated through Gaussian waveform fitting method. The results of this study are important for using ATM and LVIS to calibrate/validate CryoSat-2 results and bridging the data gap between ICESat and ICESat-2.

  5. The Biomass Site Assessment Model - BioSAT

    Science.gov (United States)

    James H. Perdue; Timothy M. Young; Timothy G. Rials

    2011-01-01

    The 20th century was marked by rapid growth and increased prosperity in the world. By 2020, the world’s energy consumption is predicted to be 40% higher than it is today, even in the presence of the global 2008/2009 economic recession (Energy Information Administration 2009). Key sources of oil for U.S. markets are located in complex geopolitical environments that...

  6. Application of Max-SAT-based ATPG to optimal cancer therapy design.

    Science.gov (United States)

    Lin, Pey-Chang Kent; Khatri, Sunil P

    2012-01-01

    Cancer and other gene related diseases are usually caused by a failure in the signaling pathway between genes and cells. These failures can occur in different areas of the gene regulatory network, but can be abstracted as faults in the regulatory function. For effective cancer treatment, it is imperative to identify faults and select appropriate drugs to treat the faults. In this paper, we present an extensible Max-SAT based automatic test pattern generation (ATPG) algorithm for cancer therapy. This ATPG algorithm is based on Boolean Satisfiability (SAT) and utilizes the stuck-at fault model for representing signaling faults. A weighted partial Max-SAT formulation is used to enable efficient selection of the most effective drug. Several usage cases are presented for fault identification and drug selection. These cases include the identification of testable faults, optimal drug selection for single/multiple known faults, and optimal drug selection for overall fault coverage. Experimental results on growth factor (GF) signaling pathways demonstrate that our algorithm is flexible, and can yield an exact solution for each feature in much less than 1 second.

  7. Emergence of foot-and-mouth disease virus SAT 2 in Egypt during 2012.

    Science.gov (United States)

    Ahmed, H A; Salem, S A H; Habashi, A R; Arafa, A A; Aggour, M G A; Salem, G H; Gaber, A S; Selem, O; Abdelkader, S H; Knowles, N J; Madi, M; Valdazo-González, B; Wadsworth, J; Hutchings, G H; Mioulet, V; Hammond, J M; King, D P

    2012-12-01

    The epidemiology of foot-and-mouth disease (FMD) in North Africa is complicated by the co-circulation of endemic FMD viruses (FMDV), as well as sporadic incursions of exotic viral strains from the Middle East and Sub-Saharan Africa. This report describes the molecular characterization of SAT 2 FMD viruses that have caused widespread field outbreaks of FMD in Egypt during February and March 2012. Phylogenetic analysis showed that viruses from these outbreaks fell into two distinct lineages within the SAT 2 topotype VII, which were distinct from a contemporary SAT 2 lineage of the same toptype from Libya. These were the first FMD outbreaks due to this serotype in Egypt since 1950 and required the development of a tailored real-time reverse-transcription PCR assay that can be used in the laboratory to distinguish FMD viruses of these lineages from other endemic FMD viruses that might be present in North Africa. These data highlight the ease by which FMDV can cross international boundaries and emphasize the importance of deploying systems to continuously monitor the global epidemiology of this disease. © 2012 Blackwell Verlag GmbH.

  8. The role of socioeconomic status in SAT-grade relationships and in college admissions decisions.

    Science.gov (United States)

    Sackett, Paul R; Kuncel, Nathan R; Beatty, Adam S; Rigdon, Jana L; Shen, Winny; Kiger, Thomas B

    2012-09-01

    This article examines the role of socioeconomic status (SES) in the relationships among college admissions-test scores, secondary school grades, and subsequent academic performance. Scores on the SAT (a test widely used in the admissions process in the United States), secondary school grades, college grades, and SES measures from 143,606 students at 110 colleges and universities were examined, and results of these analyses were compared with results obtained using a 41-school data set including scores from the prior version of the SAT and using University of California data from prior research on the role of SES. In all the data sets, the SAT showed incremental validity over secondary school grades in predicting subsequent academic performance, and this incremental relationship was not substantially affected by controlling for SES. The SES of enrolled students was very similar to that of specific schools' applicant pools, which suggests that the barrier to college for low-SES students in the United States is a lower rate of entering the college admissions process, rather than exclusion on the part of colleges.

  9. Micropropulsion Options for the TechSat21 Space-Based Radar Flight

    Science.gov (United States)

    Schlling, John H.; Spres, Ronald A.; Spanjers, Gregory G.

    1999-11-01

    An assessment of current micropropulsion concepts and their applicability to a new Air Force mission called TechSat21 is given. The goal of TechSat21 is to demonstrate the critical technologies for a formation-flying constellation of satellites that will perform space based radar. The propulsion system must accomplish an initial ascent, 10 year stationkeeping and drag makeup, and end-of-life deorbit. Major constraints on the propulsion system are total mass, minimum impulse bit, and contamination or other interference with the constellation. Due to its technical maturity, high performance, ease of integration, and potential for improved performance over the next couple of years, the recommended propulsion system is the conventional Pulsed Plasma Thruster (PPT) for primary propulsion and the Micro-PPT for stationkeeping. A low-power Hall thruster (-200 W) for primary propulsion and Micro-PPT for stationkeeping is also a strong candidate. Electrodynamic tethers for the deorbits offer a means for further reducing the propulsion mass, albeit at the expense of increased developmental and integration costs. If significant developmental risk is acceptable, the Micro Field Ionization Thruster (MFIT) offers the lowest propulsion system mass, however it is not expected to be available in the timeframe required for the TechSat21 mission.

  10. Signal Amplification Technique (SAT): an approach for improving resolution and reducing image noise in computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Phelps, M.E.; Huang, S.C.; Hoffman, E.J.; Plummer, D.; Carson, R.

    1981-01-01

    Spatial resolution improvements in computed tomography (CT) have been limited by the large and unique error propagation properties of this technique. The desire to provide maximum image resolution has resulted in the use of reconstruction filter functions designed to produce tomographic images with resolution as close as possible to the intrinsic detector resolution. Thus, many CT systems produce images with excessive noise with the system resolution determined by the detector resolution rather than the reconstruction algorithm. CT is a rigorous mathematical technique which applies an increasing amplification to increasing spatial frequencies in the measured data. This mathematical approach to spatial frequency amplification cannot distinguish between signal and noise and therefore both are amplified equally. We report here a method in which tomographic resolution is improved by using very small detectors to selectively amplify the signal and not noise. Thus, this approach is referred to as the signal amplification technique (SAT). SAT can provide dramatic improvements in image resolution without increases in statistical noise or dose because increases in the cutoff frequency of the reconstruction algorithm are not required to improve image resolution. Alternatively, in cases where image counts are low, such as in rapid dynamic or receptor studies, statistical noise can be reduced by lowering the cutoff frequency while still maintaining the best possible image resolution. A possible system design for a positron CT system with SAT is described.

  11. Environmental design implications for two deep space SmallSats

    Science.gov (United States)

    Kahn, Peter; Imken, Travis; Elliott, John; Sherwood, Brent; Frick, Andreas; Sheldon, Douglas; Lunine, Jonathan

    2017-10-01

    The extreme environmental challenges of deep space exploration force unique solutions to small satellite design in order to enable their use as scientifically viable spacecraft. The challenges of implementing small satellites within limited resources can be daunting when faced with radiation effects on delicate electronics that require shielding or unique adaptations for protection, or mass, power and volume limitations due to constraints placed by the carrier spacecraft, or even Planetary Protection compliant design techniques that drive assembly and testing. This paper will explore two concept studies where the environmental constraints and/or planetary protection mitigations drove the design of the Flight System. The paper will describe the key technical drivers on the Sylph mission concept to explore a plume at Europa as a secondary free-flyer as a part of the planned Europa Mission. Sylph is a radiation-hardened smallsat concept that would utilize terrain relative navigation to fly at low altitudes through a plume, if found, and relay the mass spectra data back through the flyby spacecraft during its 24-h mission. The second topic to be discussed will be the mission design constraints of the Near Earth Asteroid (NEA) Scout concept. NEAScout is a 6U cubesat that would utilize an 86 sq. m solar sail as propulsion to execute a flyby with a near-Earth asteroid and help retire Strategic Knowledge Gaps for future human exploration. NEAScout would cruise for 24 months to reach and characterize one Near-Earth asteroid that is representative of Human Exploration targets and telemeter that data directly back to Earth at the end of its roughly 2.5 year mission.

  12. Arctic sea ice freeboard from CryoSat-2: Validation using data from the first IceBridge underflight

    Science.gov (United States)

    Connor, L. N.; Laxon, S. W.; McAdoo, D. C.; Ridout, A.; Cullen, R.; Farrell, S.; Francis, R.

    2011-12-01

    Exact determination of thickness changes in Arctic sea ice is a primary goal of ESA's CryoSat-2 mission. Since its launch on April 8, 2010, CryoSat has collected data to map sea ice thickness and thereby monitor climate-driven ice thickness change. On April 20, 2010 just 12 days after CryoSat's launch - during NASA's IceBridge Spring 2010 campaign, the NASA DC-8 conducted a spatially and temporally coincident survey along some 670 km of a CryoSat ground-track in the northernmost Arctic Ocean. The DC-8 survey was flown out and back along the CryoSat ground-track. The DC-8 collected two laser altimetry datasets: (1) Laser Vegetation Imaging Sensor (LVIS) data, and (2) scanning laser Airborne Topographic Mapper (ATM) data. IceBridge also collected a number of other important data types including digital photography of sea ice, snow thickness radar, Ku-band radar altimetry and gravimetry, which are coincident and nearly simultaneous with SAR-mode Synthetic aperture Interferometric Radar ALtimeter (SIRAL) data collected by CryoSat. LVIS data were collected on the outbound high-altitude (25,000 feet) flight leg while ATM data were collected on the return, low-altitude (1500 feet) flight leg. CryoSat's SIRAL altimeter data are used to retrieve freeboard, i.e., the height of the ice surface above that of the local sea surface (observed in leads). Freeboard can be used to estimate sea ice thickness by assuming the ice is in isostatic equilibrium. In this investigation we compare freeboard retrievals from CryoSat with freeboard estimates derived using IceBridge data. Corrections for snow thickness are applied using IceBridge radar data. Freeboards retrieved using (a) LVIS data and (b) ATM data, are compared with CryoSat freeboard estimates. These two comparisons taken together provide an important assessment of CryoSat's capabilities to precisely map freeboard and thickness change of Arctic sea ice.

  13. Investigating the impact of haze on cloud detection of passive satellite by comparing MODIS, CloudSat and CALIPSO

    Science.gov (United States)

    Gong, W.; Mao, F.

    2015-12-01

    The cloud detection algorithm for passive sensors is usually based on a fuzzy logic system with thresholds determined from previous observations. In recent years, haze and high aerosol concentrations with high AOD occur frequently in China and may critically impact the accuracy of the MODIS cloud detection. Thus, we comprehensively explore this impact by comparing the results from MODIS/Aqua (passive sensor), CALIOP/CALIPSO (lidar sensor), and CPR/CloudSat (microwave sensor) of the A-Train suite of instruments using an averaged AOD as an index for an aerosol concentration value. Case studies concerning the comparison of the three sensors indicate that MODIS cloud detection is reduced during haze events. In addition, statistical studies show that an increase in AOD creates an increase in the percentage of uncertain flags and a decrease in hit rate, a consistency index between consecutive sets of cloud retrievals. Therefore, we can conclude that the ability of MODIS cloud detection is weakened by large concentrations of aerosols. This suggests that use of the MODIS cloud mask, and derived higher level products, in situations with haze requires caution. Further improvement of this retrieval algorithm, is desired as haze studies based on MODIS products are of great interest in a number of related fields.

  14. Statistical Comparison of Cloud and Aerosol Vertical Properties between Two Eastern China Regions Based on CloudSat/CALIPSO Data

    Directory of Open Access Journals (Sweden)

    Yujun Qiu

    2017-01-01

    Full Text Available The relationship between cloud and aerosol properties was investigated over two 4° × 4° adjacent regions in the south (R1 and in the north (R2 in eastern China. The CloudSat/CALIPSO data were used to extract the cloud and aerosol profiles properties. The mean value of cloud occurrence probability (COP was the highest in the mixed cloud layer (−40°C~0°C and the lowest in the warm cloud layer (>0°C. The atmospheric humidity was more statistically relevant to COP in the warm cloud layer than aerosol condition. The differences in COP between the two regions in the mixed cloud layer and ice cloud layer (<−40°C had good correlations with those in the aerosol extinction coefficient. A radar reflectivity factor greater than −10 dBZ occurred mainly in warm cloud layers and mixed cloud layers. A high-COP zone appeared in the above-0°C layer with cloud thicknesses of 2-3 km in both regions and in all the four seasons, but the distribution of the zonal layer in R2 was more continuous than that in R1, which was consistent with the higher aerosol optical thickness in R2 than in R1 in the above-0°C layer, indicating a positive correlation between aerosol and cloud probability.

  15. A pico-satellite assembled and tested during the 6th CanSat Leader Training Program

    Directory of Open Access Journals (Sweden)

    Angel Colin

    2017-02-01

    Full Text Available In this paper, we describe the process to construct a pico-satellite mounted in a bottle of polyethylene terephthalate (PET of 345 ml. The assembly and tests were made during the 6th CanSat Leader Training Program (CLTP-6 at University Hokkaido-Japan in the summer 2015. The pico-satellite was launched in the facilities of Uematsu Electric Co. Ltd. in Akabira-Japan by a paper model rocket, which achieved a height of approximately 100 m. The mission was designed to measure physical variables, such as temperature and humidity using electronic sensors. During the flight, we observed that the temperature inside the rocket was ∼0.5 °C higher than the temperature of the environment. We registered a humidity difference of ∼5%, measured between the maximum height and the landing point. The flight pattern was projected to a plane that covers an area of 50 m × 50 m by means the coordinates of a GPS.

  16. Operating Small Sat Swarms as a Single Entity: Introducing SODA

    Science.gov (United States)

    Conn, Tracie; Dono Perez, Andres

    2017-01-01

    Swarm concepts are a growing topic of interest in the small satellite community. Compared to a small satellite constellation, a swarm has the distinction of being multiple spacecraft in close proximity, in approximately the same orbit. Furthermore, we envision swarms to have capabilities for cross-link communication and station-keeping. Of particular interest is a means to maintain operator-specified geometry, alignment, and/or separation.From NASA's decadal survey, it is clear that simultaneous measurements from a 3D volume of space are desired for a variety of Earth scientific studies. As this mission concept is ultimately extended to deep space, some degree of local control for the swarm to self-correct its configuration is required. We claim that the practicality of ground commanding each individual satellite in the swarm is simply not a feasible concept of operations. In other words, the current state-of-practice does not scale to very large swarms (e.g. 100 spacecraft or more) without becoming cost prohibitive. To contain the operations costs and complexity, a new approach is required: the swarm must be operated as a unit, responding to high-level specifications for relative position and velocity.The Mission Design Division at NASA Ames Research Center is looking to the near future for opportunities to develop satellite swarm technology. As part of this effort, we are developing SODA (Swarm Orbital Dynamics Advisor), a tool that provides the orbital maneuvers required to achieve a desired type of relative swarm motion. The purpose of SODA is two-fold. First, it encompasses the algorithms and orbital dynamics model to enable the desired relative motion of the swarm satellites. The process starts with the user specifying the properties of a swarm configuration. This could be as simple as varying in-track spacing of the swarm in one orbit, or as complex as maintaining a specified 3D geometrical orientation. We presume that science objectives will drive this

  17. CryoTop - CryoSat-2 swath elevation and derived Digital Elevation Models and rates of elevation change products

    Science.gov (United States)

    Gourmelen, N.; Hogg, A.; Escorihuela, M. J.; Wuite, J.; Nagler, T.; Roca, M.; Shepherd, A.; Drinkwater, M. R.

    2016-12-01

    Reference and repeat-observations of ice sheet margin topography is critical to identify changes in ice thickness, provide estimates of mass gain or loss and thus quantify the contribution of the cryosphere to sea level change. The ESA Altimetry mission CryoSat-2 aims at gaining better insight into the evolution of the cryosphere, in particular over the steep slopes typically found along ice sheet margins where the majority of the mass loss is taking place. CryoSat's revolutionary design features a Synthetic Interferometric Radar Altimeter (SIRAL), with two antennas for interferometry, the corresponding SAR Interferometer (SARIn) mode of operation increases spatial resolution while resolving the angular origin of off-nadir echoes occurring over sloping terrain. The SARIn mode is activated over ice sheet margins and the elevation for the Point Of Closest Approach (POCA), or level-2, is a standard product of the CryoSat-2 mission. CryoSat-2 SARIn mode allows a new approach for more comprehensively exploiting the CryoSat-2 record and produce ice elevation and elevation change with enhanced spatial resolution compared to standard CryoSat-2 level-2 products. In this so-called CryoSat-2 Swath SARIn (CSSARIn) approach, the entire waveform is analysed providing elevation beyond the POCA, leading to between 1 and 2 orders of magnitude more elevation measurements than conventional level-2 product. As part of the European Space Agency project CryoTop Evolution we are generating CSSARIn elevation, Digital Elevation Models and maps of rates of surface elevation change over the Greenland and Antarctic Ice Sheets. These products will be generated and distributed to the community. Here we will present the methods and quality assessment of the products as well as showcase examples of the added value of the products.

  18. DOT or SAT for Rifampicin-resistant tuberculosis? A non-randomized comparison in a high HIV-prevalence setting.

    Science.gov (United States)

    Mohr, Erika; Daniels, Johnny; Beko, Busisiwe; Isaakidis, Petros; Cox, Vivian; Steele, Sarah Jane; Muller, Odelia; Snyman, Leigh; De Azevedo, Virginia; Shroufi, Amir; Trivino Duran, Laura; Hughes, Jennifer

    2017-01-01

    Daily directly-observed therapy (DOT) is recommended for rifampicin-resistant tuberculosis (RR-TB) patients throughout treatment. We assessed the impact of self-administered treatment (SAT) in a South African township with high rates of RR-TB and HIV. Community-supported SAT for patients who completed the intensive phase was piloted in five primary care clinics in Khayelitsha. We compared final treatment outcomes among RR-TB patients initiating treatment before (standard-of-care (SOC)-cohort, January 2010-July 2013) and after the implementation of the pilot (SAT-cohort, January 2012-December 2014). All patients with outcomes before January 1, 2017 were considered in the analysis of outcomes. One-hundred-eighteen patients in the SOC-cohort and 174 patients in the SAT-cohort had final RR-TB treatment outcomes; 70% and 73% were HIV-co-infected, respectively. The proportion of patients with a final outcome of loss to follow-up (LTFU) did not differ whether treated in the SOC (25/118, 21.2%) or SAT-cohort (31/174, 17.8%) (P = 0.47). There were no significant differences in the time to 24-month LTFU among HIV-infected and uninfected patients (HR 0.90, 95% CI: 0.51-1.6, P = 0.71), or among patients enrolled in the SOC-cohort versus the SAT-cohort (HR 0.83, 95% CI: 0.49-1.4, P = 0.50) who received at least 6-months of RR-TB treatment. The introduction of SAT during the continuation phase of RR-TB treatment does not adversely affect final RR-TB treatment outcomes in a high TB and HIV-burden setting. This differentiated, patient-centred model of care could be considered in RR-TB programmes to decrease the burden of DOT on patients and health facilities.

  19. Co-circulation of two extremely divergent serotype SAT 2 lineages in Kenya highlights challenges to foot-and-mouth disease control

    DEFF Research Database (Denmark)

    Sangula, Abraham; Belsham, Graham; Muwanika, Vincent

    2010-01-01

    Amongst the SAT serotypes of foot-and-mouth disease virus (FMDV), the SAT 2 serotype is the most widely distributed throughout sub-Saharan Africa. Kenyan serotype SAT 2 viruses have been reported to display the highest genetic diversity for the serotype globally. This complicates diagnosis...... and control, and it is essential that patterns of virus circulation are known in order to overcome these difficulties. This study was undertaken to establish patterns of evolution of FMDV serotype SAT 2 in Kenya using complete VP1 coding sequences in a dataset of 65 sequences from Africa, collected over...

  20. The Performance and Potentials of the CryoSat-2 SAR and SARIn Modes for Lake Level Estimation

    Directory of Open Access Journals (Sweden)

    Karina Nielsen

    2017-05-01

    Full Text Available Over the last few decades, satellite altimetry has proven to be valuable for monitoring lake levels. With the new generation of altimetry missions, CryoSat-2 and Sentinel-3, which operate in Synthetic Aperture Radar (SAR and SAR Interferometric (SARIn modes, the footprint size is reduced to approximately 300 m in the along-track direction. Here, the performance of these new modes is investigated in terms of uncertainty of the estimated water level from CryoSat-2 data and the agreement with in situ data. The data quality is compared to conventional low resolution mode (LRM altimetry products from Envisat, and the performance as a function of the lake area is tested. Based on a sample of 145 lakes with areas ranging from a few to several thousand km 2 , the CryoSat-2 results show an overall superior performance. For lakes with an area below 100 km 2 , the uncertainty of the lake levels is only half of that of the Envisat results. Generally, the CryoSat-2 lake levels also show a better agreement with the in situ data. The lower uncertainty of the CryoSat-2 results entails a more detailed description of water level variations.

  1. Preliminary Analysis of Delta-V Requirements for a Lunar CubeSat Impactor with Deployment Altitude Variations

    Directory of Open Access Journals (Sweden)

    Young-Joo Song

    2015-09-01

    Full Text Available Characteristics of delta-V requirements for deploying an impactor from a mother-ship at different orbital altitudes are analyzed in order to prepare for a future lunar CubeSat impactor mission. A mother-ship is assumed to be orbiting the moon with a circular orbit at a 90 deg inclination and having 50, 100, 150, 200 km altitudes. Critical design parameters that are directly related to the success of the impactor mission are also analyzed including deploy directions, CubeSat flight time, impact velocity, and associated impact angles. Based on derived delta-V requirements, required thruster burn time and fuel mass are analyzed by adapting four different miniaturized commercial onboard thrusters currently developed for CubeSat applications. As a result, CubeSat impact trajectories as well as thruster burn characteristics deployed at different orbital altitudes are found to satisfy the mission objectives. It is concluded that thrust burn time should considered as the more critical design parameter than the required fuel mass when deducing the onboard propulsion system requirements. Results provided through this work will be helpful in further detailed system definition and design activities for future lunar missions with a CubeSat-based payload.

  2. A scalable and accurate targeted gene assembly tool (SAT-Assembler) for next-generation sequencing data.

    Science.gov (United States)

    Zhang, Yuan; Sun, Yanni; Cole, James R

    2014-08-01

    Gene assembly, which recovers gene segments from short reads, is an important step in functional analysis of next-generation sequencing data. Lacking quality reference genomes, de novo assembly is commonly used for RNA-Seq data of non-model organisms and metagenomic data. However, heterogeneous sequence coverage caused by heterogeneous expression or species abundance, similarity between isoforms or homologous genes, and large data size all pose challenges to de novo assembly. As a result, existing assembly tools tend to output fragmented contigs or chimeric contigs, or have high memory footprint. In this work, we introduce a targeted gene assembly program SAT-Assembler, which aims to recover gene families of particular interest to biologists. It addresses the above challenges by conducting family-specific homology search, homology-guided overlap graph construction, and careful graph traversal. It can be applied to both RNA-Seq and metagenomic data. Our experimental results on an Arabidopsis RNA-Seq data set and two metagenomic data sets show that SAT-Assembler has smaller memory usage, comparable or better gene coverage, and lower chimera rate for assembling a set of genes from one or multiple pathways compared with other assembly tools. Moreover, the family-specific design and rapid homology search allow SAT-Assembler to be naturally compatible with parallel computing platforms. The source code of SAT-Assembler is available at https://sourceforge.net/projects/sat-assembler/. The data sets and experimental settings can be found in supplementary material.

  3. Perceptions of a reproductive health self-assessment tool (RH-SAT) in an urban community health center.

    Science.gov (United States)

    Bello, Jennifer K; Adkins, Katlynn; Stulberg, Debra B; Rao, Goutham

    2013-12-01

    Physicians face barriers to incorporating recommended contraceptive and preconception health services, including reproductive life plans (RLPs), into primary care. With promising findings from early studies of RLPs, we examined the impact of a novel reproductive health self-assessment tool (RH-SAT) on reproductive health counseling. We created the RH-SAT for an urban community health center population and trained providers on preconception and contraceptive guidelines. Semi-structured interviews were conducted to assess perceptions of the tool with 22 patients and with all 15 providers at the clinic. Transcripts were thematically analyzed using a grounded theoretical approach. Patients and providers reported the RH-SAT presented new and thought-provoking material that promoted patient participation and facilitated counseling. This RH-SAT is acceptable and useful to patients and providers in an underserved urban health center. In accordance with Medical Communication Alignment Theory (MCAT), increased patient participation in reproductive health discussions may alert providers to patient interest in these topics. This study provides preliminary evidence that the RH-SAT can help overcome barriers to reproductive health counseling in primary care. Providers may wish to incorporate tools into their practice to improve communication with patients about their reproductive health goals. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  4. Learning higher mathematics

    CERN Document Server

    Pontrjagin, Lev Semenovič

    1984-01-01

    Lev Semenovic Pontrjagin (1908) is one of the outstanding figures in 20th century mathematics. In a long career he has made fundamental con­ tributions to many branches of mathematics, both pure and applied. He has received every honor that a grateful government can bestow. Though in no way constrained to do so, he has through the years taught mathematics courses at Moscow State University. In the year 1975 he set himself the task of writing a series of books on secondary school and beginning university mathematics. In his own words, "I wished to set forth the foundations of higher mathematics in a form that would have been accessible to myself as a lad, but making use of all my experience as a scientist and a teacher, ac­ cumulated over many years. " The present volume is a translation of the first two out of four moderately sized volumes on this theme planned by Pro­ fessor Pontrjagin. The book begins at the beginning of modern mathematics, analytic ge­ ometry in the plane and 3-dimensional space. Refin...

  5. SWEET CubeSat - Water detection and water quality monitoring for the 21st century

    Science.gov (United States)

    Antonini, Kelly; Langer, Martin; Farid, Ahmed; Walter, Ulrich

    2017-11-01

    Water scarcity and contamination of clean water have been identified as major challenges of the 21st century, in particular for developing countries. According to the International Water Management Institute, about 30% of the world's population does not have reliable access to clean water. Consequently, contaminated water contributes to the death of about 3 million people every year, mostly children. Access to potable water has been proven to boost education, equality and health, reduce hunger, as well as help the economy of the developing world. Currently used in-situ water monitoring techniques are sparse, and often difficult to execute. Space-based instruments will help to overcome these challenges by providing means for water level and water quality monitoring of medium-to-large sweet (fresh) water reservoirs. Data from hyperspectral imaging instruments on past and present governmental missions, such as Envisat and Aqua, has been used for this purpose. However, the high cost of large multi-purpose space vessels, and the lack of dedicated missions limits the continuous monitoring of inland and coastal water quality. The proposed CubeSat mission SWEET (Sweet Water Earth Education Technologies) will try to fill this gap. The SWEET concept is a joint effort between the Technical University of Munich, the German Space Operations Center and the African Steering Committee of the IAF. By using a novel Fabry-Perot interferometer-based hyperspectral imager, the mission will deliver critical data directly to national water resource centers in Africa with an unmatched cost per pixel ratio and high temporal resolution. Additionally, SWEET will incorporate education of students in CubeSat design and water management. Although the aim of the mission is to deliver local water quality and water level data to African countries, further coverage could be achieved with subsequent satellites. Finally, a constellation of SWEET-like CubeSats would extend the coverage to the whole

  6. High Resolution Energetic X-ray Imager (HREXI) for a Prototype 12U CubeSat

    Science.gov (United States)

    Hong, JaeSub; Allen, Branden; Grindlay, Jonathan E.; Barthelmy, Scott Douglas; Harrison, Fiona

    2017-08-01

    Our High Resolution Energetic X-ray Imager (HREXI) program is developing an Engineering Model (EM) for a 12U CubeSat wide-field hard X-ray (3-200 keV) coded-aperture imaging telescope. HREXI employs an array of CdZnTe (CZT) detectors (each 2 x 2 x 0.3 cm) with a fine-pixellated Tungsten coded aperture mask. The detector assembly utilizes the new technology of Through-Silicon-Vias (TSVs) to control and readout signals from the ASIC bonded to each CZT. TSVs eliminate the need for conventional wire-bonds for electric connections between the ASIC and back end electronics, greatly lowering the assembly complexity and cost, and thus enabling close-tiling of HREXI detectors in a small form factor with comfortable margins. For HREXI EM, we have successfully implemented TSVs on NuSTAR ASICs, which can cover an energy range of 3-200 keV with a FWHM spectral resolution of 1-2 keV. The 12U CubeSat HREXI EM prototype with 64 CZT detectors would image 0.5 sr of sky with FWHM field of view with 11 arcmin resolution for the current generation of the TSV-ASIC and a 20 cm mask - detector plane separation. A flight test of this 12U-HREXI will be proposed after full development and environmental testing to enable a future proposed array of SmallSat-HREXI telescopes with ~2 arcmin resolution for simultaneous full-sky studies of high redshift GRBs and a wide range of transients in the post-Swift era. (This work is supported by NASA grant NNX17AE62G)

  7. Adventures in Private Cloud: Balancing Cost and Capability at the CloudSat Data Processing Center

    Science.gov (United States)

    Partain, P.; Finley, S.; Fluke, J.; Haynes, J. M.; Cronk, H. Q.; Miller, S. D.

    2016-12-01

    Since the beginning of the CloudSat Mission in 2006, The CloudSat Data Processing Center (DPC) at the Cooperative Institute for Research in the Atmosphere (CIRA) has been ingesting data from the satellite and other A-Train sensors, producing data products, and distributing them to researchers around the world. The computing infrastructure was specifically designed to fulfill the requirements as specified at the beginning of what nominally was a two-year mission. The environment consisted of servers dedicated to specific processing tasks in a rigid workflow to generate the required products. To the benefit of science and with credit to the mission engineers, CloudSat has lasted well beyond its planned lifetime and is still collecting data ten years later. Over that period requirements of the data processing system have greatly expanded and opportunities for providing value-added services have presented themselves. But while demands on the system have increased, the initial design allowed for very little expansion in terms of scalability and flexibility. The design did change to include virtual machine processing nodes and distributed workflows but infrastructure management was still a time consuming task when system modification was required to run new tests or implement new processes. To address the scalability, flexibility, and manageability of the system Cloud computing methods and technologies are now being employed. The use of a public cloud like Amazon Elastic Compute Cloud or Google Compute Engine was considered but, among other issues, data transfer and storage cost becomes a problem especially when demand fluctuates as a result of reprocessing and the introduction of new products and services. Instead, the existing system was converted to an on premises private Cloud using the OpenStack computing platform and Ceph software defined storage to reap the benefits of the Cloud computing paradigm. This work details the decisions that were made, the benefits that

  8. CryoSat-2-only gravity model of the Mediterranean: topographic effects and validation

    Science.gov (United States)

    Abulaitijiang, Adili; Barzaghi, Riccardo; Carrion, Daniela; Baltazar Andersen, Ole; Knudsen, Per

    2017-04-01

    The long repeat cycle of the Cryostat-2 provides dense cross track coverage. Combined with the better along track resolution and precision, the 6 years of CryoSat-2 data can be potentially used to extract the high frequency components of the Earth gravity field beyond the Global Geopotential Models (GGMs) which corresponds to a resolution of 9.2 Km at the degree 2160. The high resolution bathymetry models, e.g., SRTM30, correspond to the spatial resolution of around 1 Km. High resolution bathymetry data is used to account for the strong correlation in the short wavelength (1 10 km) gravity features with topography and bathymetry. In this work, with remove-restore technique and Residual Terrain Model (RTM) reduction (using SRTM30), the topographic contribution to the geoid undulation will be examined in several patches (2°×3°) in the Mediterranean. The covariance function of the residual height anomalies with and without the RTM reduction will be estimated and a proper covariance fitting algorithm will introduced when the assumption of isotropy and homogeneity is fulfilled. Then the Least Square Collocation (LSC) algorithm is used to derive the residual gravity anomalies over the ship tracks from the CryoSat-2-only height anomalies. The "full wavelength" true gravity measurement along the ship tracks then will be used to evaluate the final results and performance of the LSC solutions. Alternatively, the FFT method will also be tested, provided that the height anomalies are gridded. The CryoSat-2 altimetry data is retracker and operation mode dependent. Since different retrackers and operation modes (e.g., LRM or SAR) could produce altimetry products with different precision and accuracy, different altimetry datasets, e.g., from RADS and GPOD, will be tested and compared.

  9. Quasi-thermal noise and shot noise spectroscopy on a CubeSat in Earth's ionosphere

    Science.gov (United States)

    Maj, Ronald; Cairns, Iver H.

    2017-03-01

    We investigate the practicality of using quasi-thermal noise (QTN) and shot noise spectroscopy on a CubeSat in the Earth's ionosphere and constrain the satellite antenna length for optimal detection of these signals. The voltage spectra predicted for thermal Langmuir waves (QTN) and particle "shot noise" are modeled, and it is shown that the signals detected can provide two very good, independent, passive, in situ methods of measuring the plasma density and temperature in the ionosphere. The impact of the antenna potential ϕ is also discussed, and we show that the negative potential calculated for the ionosphere due to natural current flows has a significant impact on the voltage power level of the shot noise spectrum. The antenna configuration is also shown to play an important role in the shot noise, with a monopole configuration enhancing the spectrum significantly compared with a dipole. Antenna lengths on the order of 20-40 cm are found to be ideal for ionospheric plasma conditions, nicely matching CubeSat sizes and producing detectable thermal Langmuir waves and shot noise at the microvolt level. Further, with a continuous stream of data points at different latitudes and longitudes an orbiting CubeSat can produce a global picture for the ionospheric plasma density and temperature using QTN and shot noise signals. If implemented, especially in a constellation, these data would be more frequent and cover a much greater domain than current ground-based or single-satellite methods. This could lead to improved ionospheric models, such as the empirically based International Reference Ionosphere.

  10. New insights about cloud vertical structure from CloudSat and CALIPSO observations

    Science.gov (United States)

    Oreopoulos, Lazaros; Cho, Nayeong; Lee, Dongmin

    2017-09-01

    Active cloud observations from A-Train's CloudSat and CALIPSO satellites offer new opportunities to examine the vertical structure of hydrometeor layers. We use the 2B-CLDCLASS-LIDAR merged CloudSat-CALIPSO product to examine global aspects of hydrometeor vertical stratification. We group the data into major cloud vertical structure (CVS) classes based on our interpretation of how clouds in three standard atmospheric layers overlap and provide their global frequency of occurrence. The two most frequent CVS classes are single-layer (per our definition) low and high clouds that represent 53% of cloudy skies, followed by high clouds overlying low clouds, and vertically extensive clouds that occupy near-contiguously a large portion of the troposphere. The prevalence of these configurations changes seasonally and geographically, between daytime and nighttime, and between continents and oceans. The radiative effects of the CVS classes reveal the major radiative warmers and coolers from the perspective of the planet as a whole, the surface, and the atmosphere. Single-layer low clouds dominate planetary and atmospheric cooling and thermal infrared surface warming. We also investigate the consistency between passive and active views of clouds by providing the CVS breakdowns of Moderate Resolution Imaging Spectroradiometer cloud regimes for spatiotemporally coincident MODIS-Aqua (also on the A-Train) and CloudSat-CALIPSO daytime observations. When the analysis is expanded for a more in-depth look at the most heterogeneous of the MODIS cloud regimes, it ultimately confirms previous interpretations of their makeup that did not have the benefit of collocated active observations.

  11. NASA's Physics of the Cosmos and Cosmic Origins programs manage Strategic Astrophysics Technology (SAT) development

    Science.gov (United States)

    Pham, Thai; Thronson, Harley; Seery, Bernard; Ganel, Opher

    2016-07-01

    The strategic astrophysics missions of the coming decades will help answer the questions "How did our universe begin and evolve?" "How did galaxies, stars, and planets come to be?" and "Are we alone?" Enabling these missions requires advances in key technologies far beyond the current state of the art. NASA's Physics of the Cosmos2 (PCOS), Cosmic Origins3 (COR), and Exoplanet Exploration Program4 (ExEP) Program Offices manage technology maturation projects funded through the Strategic Astrophysics Technology (SAT) program to accomplish such advances. The PCOS and COR Program Offices, residing at the NASA Goddard Space Flight Center (GSFC), were established in 2011, and serve as the implementation arm for the Astrophysics Division at NASA Headquarters. We present an overview of the Programs' technology development activities and the current technology investment portfolio of 23 technology advancements. We discuss the process for addressing community-provided technology gaps and Technology Management Board (TMB)-vetted prioritization and investment recommendations that inform the SAT program. The process improves the transparency and relevance of our technology investments, provides the community a voice in the process, and promotes targeted external technology investments by defining needs and identifying customers. The Programs' priorities are driven by strategic direction from the Astrophysics Division, which is informed by the National Research Council's (NRC) "New Worlds, New Horizons in Astronomy and Astrophysics" (NWNH) 2010 Decadal Survey report [1], the Astrophysics Implementation Plan (AIP) [2] as updated, and the Astrophysics Roadmap "Enduring Quests, Daring Visions" [3]. These priorities include technology development for missions to study dark energy, gravitational waves, X-ray and inflation probe science, and large far-infrared (IR) and ultraviolet (UV)/optical/IR telescopes to conduct imaging and spectroscopy studies. The SAT program is the

  12. CryoSat-2 Validation using CryoVEX 2011-12 Airborne Campaigns

    DEFF Research Database (Denmark)

    Skourup, Henriette; Forsberg, René; Kildegaard Rose, Stine

    (SIRAL), the aircraft is equipped with an airborne version of the SIRAL altimeter (ASIRAS) together with a laser scanner. The campaigns are focused on five main validation sites: Devon ice cap (Canada), Austfonna ice cap (Svalbard), the EGIG line crossing the Greenland Ice Sheet, as well as the sea ice...... north of Alert and sea ice around Svalbard in the Fram Strait. Selected tracks were planned to match CryoSat-2 passes and a few of them were flown in formation flight with the Alfred Wegener Institute (AWI) Polar-5 carrying an EM-bird. This presentation summarizes the 2011-12 airborne campaigns...

  13. iSAT: The Integrated Satellite and Acoustic Telemetry system for tracking marine megafauna

    KAUST Repository

    De La Torre, Pedro R.

    2014-05-01

    In this dissertation an innovative technology to study whale sharks, Rhincodon typus is presented. The Integrated Satellite and Acoustic Telemetry project (iSAT) combines underwater acoustic telemetry, autonomous navigation and radio frequency communications into a standalone system. The whale shark, a resident of the Saudi Arabian Red Sea, is the target of the study. The technology presented is designed to help close current gaps in the knowledge of whale shark biology; these are gaps that prohibit the design of optimal conservation strategies. Unfortunately, the various existing tracking technologies each have limitations and are unable to solve all the unanswered questions. Whale shark populations are increasingly threatened by anthropogenic activities such as targeted and indirect fishing pressure, creating an urgent need for better management practices. This dissertation addresses the current state-of-the-art of relevant technologies, including autonomous surface vehicles (ASVs), sensors for research in the ocean and remote monitoring of wild fauna (biotelemetry). iSAT contains components of all of these technologies, but the primary achievement of this dissertation is the development of iSAT’s Acoustic Tracking System (ATS). Underwater, the most efficient way of transmitting energy through long distances is sound. An electronic tag is attached to an animal and works as its acoustic identifier. iSAT’s hydrophone array detects the presence and direction of the acoustic signal generated by the tag. The expected performance, range, and capacity to tell the direction to the tag are explained and compared to the actual measured values. The first operational iSAT ATS is demonstrated. This work represents significant advancement towards a fully autonomous iSAT system. Developments on the power electronics, navigation, renewable energy harvesting, and other modules are included in this research. With the recent integration of digital acquisition systems, i

  14. The Brazilian INPE-UFSM NANOSATC-BR CubeSat Development Capacity Building Program

    Science.gov (United States)

    Schuch, Nelson Jorge; Cupertino Durao, Otavio S.

    The Brazilian INPE-UFSM NANOSATC-BR CubeSat Development Capacity Building Program (CBP) and the results of the NANOSATC-BR1, the first Brazilian CubeSat launching, expected for 2014's first semester, are presented. The CBP consists of two CubeSats, NANOSATC-BR 1 (1U) & 2 (2U) and is expected operate in orbit for at least 12 months each, with capacity building in space science, engineering and computer sciences for the development of space technologies using CubeSats satellites. The INPE-UFSM’s CBP Cooperation is basically among: (i) the Southern Regional Space Research Center (CRS), from the Brazilian INPE/MCTI, where acts the Program's General Coordinator and Projects NANOSATC-BR 1 & 2 Manager, having technical collaboration and management of the Mission’s General Coordinator for Engineering and Space Technology at INPE’s Headquarter (HQ), in São José dos Campos, São Paulo; (ii) the Santa Maria Space Science Laboratory (LACESM/CT) from the Federal University of Santa Maria - (UFSM); (iii) the Santa Maria Design House (SMDH); (iv) the Graduate Program in Microelectronics from the Federal University of Rio Grande do Sul (MG/II/UFRGS); and (v) the Aeronautic Institute of Technology (ITA/DCTA/CA-MD). The INPE-UFSM’s CBP has the involvement of UFSM' undergraduate students and graduate students from: INPE/MCTI, MG/II/UFRGS and ITA/DCTA/CA-MD. The NANOSATC-BR 1 & 2 Projects Ground Stations (GS) capacity building operation with VHF/UHF band and S-band antennas, are described in two specific papers at this COSPAR-2014. This paper focuses on the development of NANOSATC-BR 1 & 2 and on the launching of NANOSATC-BR1. The Projects' concepts were developed to: i) monitor, in real time, the Geospace, the Ionosphere, the energetic particle precipitation and the disturbances at the Earth's Magnetosphere over the Brazilian Territory, and ii) the determination of their effects on regions such as the South American Magnetic Anomaly (SAMA) and the Brazilian sector of the

  15. Mobile CubeSat Command and Control: Assembly and Lessons Learned

    Science.gov (United States)

    2011-09-01

    suppliers like Pumpkin , Clyde Space, and GomSpace which share exhibition booths with students from top universities around the world. The week of...integrated and tested. 1. Hardware and Software The NRL Colony I satellites, designated QbX 1 and 2, were based on the Pumpkin XS-25a CubeSat bus...main components to the MC3. The hard plastic shell and wheels put 18 the mobile in MC3. While an MC3 is not designed to be used, literally, on the

  16. Characterizing DebriSat Fragments: So Many Fragments, So Much Data, and So Little Time

    Science.gov (United States)

    Shiotani, B.; Rivero, M.; Carrasquilla, M.; Allen, S.; Fitz-Coy, N.; Liou, J.-C.; Huynh, T.; Sorge, M.; Cowardin, H.; Opiela, J.; hide

    2017-01-01

    To improve prediction accuracy, the DebriSat project was conceived by NASA and DoD to update existing standard break-up models. Updating standard break-up models require detailed fragment characteristics such as physical size, material properties, bulk density, and ballistic coefficient. For the DebriSat project, a representative modern LEO spacecraft was developed and subjected to a laboratory hypervelocity impact test and all generated fragments with at least one dimension greater than 2 mm are collected, characterized and archived. Since the beginning of the characterization phase of the DebriSat project, over 130,000 fragments have been collected and approximately 250,000 fragments are expected to be collected in total, a three-fold increase over the 85,000 fragments predicted by the current break-up model. The challenge throughout the project has been to ensure the integrity and accuracy of the characteristics of each fragment. To this end, the post hypervelocity-impact test activities, which include fragment collection, extraction, and characterization, have been designed to minimize handling of the fragments. The procedures for fragment collection, extraction, and characterization were painstakingly designed and implemented to maintain the post-impact state of the fragments, thus ensuring the integrity and accuracy of the characterization data. Each process is designed to expedite the accumulation of data, however, the need for speed is restrained by the need to protect the fragments. Methods to expedite the process such as parallel processing have been explored and implemented while continuing to maintain the highest integrity and value of the data. To minimize fragment handling, automated systems have been developed and implemented. Errors due to human inputs are also minimized by the use of these automated systems. This paper discusses the processes and challenges involved in the collection, extraction, and characterization of the fragments as well as the

  17. Modeling and solving semiring constraint satisfaction problems by transformation to weighted semiring Max-SAT

    CSIR Research Space (South Africa)

    Leenen, L

    2007-12-01

    Full Text Available Constraint Satisfaction Problems by Transformation to Weighted Semiring Max-SAT Louise Leenen1, Anbulagan2, Thomas Meyer3, and Aditya Ghose4 1 DSL, SCSSE, University of Wollongong, Australia and DPSS, CSIR, South Africa 2 NICTAstarstar and ANU, Canberra...., Verfaillie, G.: Semiring-based CSPs and valued CSPs: Basic properties and comparison. Con- straints 4 (1999) 199–240 8. Bistarelli, S., Fung, S., Lee, J., Leung, H.: A local search framework for semiring- based constraint satisfaction problems. In: Soft...

  18. Federico García Lorca : una obra teatral satírica /

    OpenAIRE

    Ferrada Castro, Susana

    2016-01-01

    Departament responsable de la tesi: Departament de Filologia Espanyola Federico García Lorca: una obra teatral satírica es el resultado de una investigación sin precedentes, pues, a pesar de lo mucho que se ha escrito sobre Federico García Lorca y su obra, la hipótesis en la que se ha fundamentado esta investigación implica una interpretación inédita de la obra lorquiana y, al mismo tiempo, supone una nueva percepción del poeta, al ahondar en una faceta de su controvertida personalidad de ...

  19. Preliminary gravity recovery from CryoSat-2 data in the Baffin Bay

    DEFF Research Database (Denmark)

    Stenseng, Lars; Andersen, Ole Baltazar

    2012-01-01

    with respect to conventional satellite altimetry: factor of 20 improvements in the along-track resolution, the along-track footprint length which does not vary with wave height (sea state), and improved precision in sea surface height measurements or sea surface slope measurements. In this paper...... recovery of geophysical signal was achieved from measurements averaged to 5 Hz, rather than the simulated 20 Hz full resolution data. A first validation of these theoretical modelling results with respect to resolution and noise is presented using various CryoSat-2 data, and evaluated against conventional...

  20. SatCom for in situ Earth observation and disaster response

    Science.gov (United States)

    Fonseca, Joao

    2010-05-01

    Efficient and robust communications are key to effective management of natural risk and response to disasters. But even in the most developed regions, where the telecommunication backbone provides widespread access to data from monitoring stations in most cases, the institutions who are in charge of alerting civil protection agencies of impending disasters often struggle with telecommunications running costs. In remote regions, telecommunications infrastructure is often scarce and vulnerable to natural disasters, both directly and as a result of the peak of demand that accompanies a crisis.The advent of SatCom, namely VSAT, was heralded as an opportunity for the inclusion of remote regions in the natural hazard monitoring effort. But, while the technical characteristics of satellite communications are suited to achieve that goal, service costs remain a hurdle that hampers widespread use of SatCom for this purpose. The INSPIRE Directive (2007/2/EC) laid down general rules for the establishment of the Infrastructure for Spatial Information in the European Community, for the purposes of Community environmental policies and policies or activities which may have an impact on the environment. INSPIRE builds upon infrastructures for spatial information established and operated by the Member States. The Tampere Convention on Satellite for Disaster Relief and Mitigation was subscribed by 60 countries in 2005 provide the framework for agreement on satellite and other telecommunication matters in most operations of international humanitarian operations. I propose that the potential of SatCom to in situ data retrieval can be better exploited through innovative forms of organization among the end users, and EPOS provides a unique platform to test and implement this approach. The first steps towards the necessary change are: 1) to test different SatCom solutions currently available, evaluating their relative merits towards the expected cost reduction through end user cooperation

  1. CubeSat mechanical design: creating low mass and durable structures

    Science.gov (United States)

    Fiedler, Gilbert; Straub, Jeremy

    2017-05-01

    This paper considers the mechanical design of a low-mass, low-cost spacecraft for use in a multi-satellite sensing constellation. For a multi-spacecraft mission, aggregated small mass and cost reductions can have significant impact. One approach to mass reduction is to make cuts into the structure, removing material. Stress analysis is used to determine the level of material reduction possible. Focus areas for this paper include determining areas to make cuts to ensure that a strong shape remains, while considering the comparative cost and skill level of each type of cut. Real-world results for a CubeSat and universally applicable analysis are presented.

  2. Additive Manufacturing: An Enabling Technology for the MoonBEAM 6U CubeSat Missions

    Science.gov (United States)

    Hopkins, R. C.; Hickman, R. R.; Cavender, D. P.; Dominquez, A.; Schnell, A. R.; Baysinger, M.; Capizzo, P.; Garcia, J.; Fabisinski, L. L.

    2017-01-01

    The Advanced Concepts Office at the NASA Marshall Space Flight Center completed a mission concept study for the Moon Burst Energetics All-sky Monitor (MoonBEAM). The goal of the concept study was to show the enabling aspects that additive manufacturing can provide to CubeSats. In addition to using the additively manufactured tanks as part of the spacecraft structure, the main propulsion system uses a green propellant, which is denser than hydrazine. Momentum unloading is achieved with electric microthrusters, eliminating much of the propellant plumbing. The science mission, requirements, and spacecraft design are described.

  3. Validation of CryoSat-2 SAR mode based lake levels

    DEFF Research Database (Denmark)

    Nielsen, Karina; Stenseng, Lars; Andersen, Ole Baltazar

    2015-01-01

    Lake level serve as an important indicator of the climate and continuous measurements are therefore essential. Satellite radar altimetry has now been used successfully for more than two decades to measure lake level as an addition to gauge measurements. The technique has, due to the large footprint...... of conventional altimetry, primarily been used for large lakes. CryoSat-2, which was launched in 2010, carries the first altimeter that is able to operate in SAR mode. The along-track resolution is approximately 300. m in SAR mode thus enabling us to accurately monitor substantially smaller lakes.Here we evaluate...

  4. Soft X-ray Focusing Telescope Aboard AstroSat: Design, Characteristics and Performance

    DEFF Research Database (Denmark)

    Singh, K; Stewart, G.; Westergaard, Niels Jørgen Stenfeldt

    2017-01-01

    medium resolution X-ray spectroscopy of cosmic X-ray sources of various types. It is the most sensitive X-ray instrument aboard the AstroSat. In its first year of operation, SXT has been used to observe objects ranging from active stars, compact binaries, supernova remnants, active galactic nuclei...... and clusters of galaxies in order to study its performance and quantify its characteriztics. Here, we present an overview of its design, mechanical hardware, electronics, data modes, observational constraints, pipeline processing and its in-orbit performance based on preliminary results from its...

  5. Movimiento de un satélite alrededor de un planeta achatado

    OpenAIRE

    Loayza Cordero, Fredy Miguel

    2011-01-01

    El objetivo de este presente trabajo es determinar y analizar el potencial gravitatorio debido a una masa gravitatoria distribuida uniformemente en un elipsoide de revolución. Aplicaremos la expansión multipolar para determinar el potencial gravitacional para el planeta y así obtendremos una expresión para la fuerza gravitacional. Luego aplicar este potencial en dos problemas reales, por ejemplo el movimiento de satélites naturales alrededor del planeta Saturno (que es achatado por los pol...

  6. Development of Lightweight CubeSat with Multi-Functional Structural Battery Systems

    Science.gov (United States)

    Karkkainen, Ryan L.; Hunter, Roger C.; Baker, Christopher

    2017-01-01

    This collaborative multi-disciplinary effort aims to develop a lightweight, 1-unit (1U) CubeSat (10x10x10 cm) which utilizes improved and fully integrated structural battery materials for mission life extension, larger payload capability, and significantly reduced mass.The electrolytic carbon fiber material serves the multifunctional capacitive energy system as both a lightweight, load bearing structure and an electrochemical battery system. This implementation will improve traditional multifunctional energy storage concepts with a highly effective energy storage capability.

  7. CryoSat Land Ice Product Validation within the CryoVal-LI project

    DEFF Research Database (Denmark)

    Sørensen, Louise Sandberg; Baker, Steven; Csatho, Bea

    The main objective of the ESA funded CryoVal-LI project has been to identify and quantify the error sources for the CryoSat-2 mission over land ice. This has been undertaken through the careful documentation of the possible error sources, the identification of suitable validation sites...... validation analysis has also been carried out for ICESat data. Here, we present the results of these analyses and outline the conclusions reached. Based on the findings from the project, a set of recommendations for the design of future land-ice/satellite validation campaigns will be given. Furthermore...

  8. EDUCAFRICA, December 1986. Special Issue: Case Studies on Higher Education in Africa. Special Volume 1=EDUCAFRICA, Decembre 1986. Etudes de cas sur L'Enseignement Superieur en Afrique, Tome 1.

    Science.gov (United States)

    EDUCAFRICA, 1986

    1986-01-01

    Case studies of the development of higher education in 17 African countries are presented. Eleven of the case studies are written in French, and six are in English. The country reports that are in English are as follows: Cameroon, Ethiopia, Lesotho, Malawi, Sierra Leone, and Tanzania. The country reports in French are: Benin, Burkina Faso,…

  9. Higher Education and Economic Development in Europe, 1975-1980 (A Statistical and Economic Study) = L'enseignement superieur et le development economique en Europe, 1975-1980 (etude statistique et economique). Volume I.

    Science.gov (United States)

    Burloiu, Petre

    Information on higher education in 33 European countries, the United States, and Canada is provided in narrative and statistical form, in both English and French. In addition to covering the 1970-1975 period, comparative information for 1960-1980 is presented. For each country, areas of consideration include: population trends; the level of…

  10. Small-Volume Injections: Evaluation of Volume Administration Deviation From Intended Injection Volumes.

    Science.gov (United States)

    Muffly, Matthew K; Chen, Michael I; Claure, Rebecca E; Drover, David R; Efron, Bradley; Fitch, William L; Hammer, Gregory B

    2017-10-01

    regression model. Analysis of variance was used to determine whether the absolute log proportional error differed by the intended injection volume. Interindividual and intraindividual deviation from the intended injection volume was also characterized. As the intended injection volumes decreased, the absolute log proportional injection volume error increased (analysis of variance, P injection volumes between physicians and pediatric PACU nurses; however, the difference in absolute bias was significantly higher for nurses with a 2-sided significance of P = .03. Clinically significant dose variation occurs when injecting volumes ≤0.5 mL. Administering small volumes of medications may result in unintended medication administration errors.

  11. The performance and potentials of the CryoSat-2 SAR and SARIn modes for lake level estimation

    DEFF Research Database (Denmark)

    Nielsen, Karina; Stenseng, Lars; Andersen, Ole Baltazar

    2017-01-01

    Over the last few decades, satellite altimetry has proven to be valuable for monitoring lake levels. With the new generation of altimetry missions, CryoSat-2 and Sentinel-3, which operate in Synthetic Aperture Radar (SAR) and SAR Interferometric (SARIn) modes, the footprint size is reduced...... to approximately 300 m in the along-track direction. Here, the performance of these new modes is investigated in terms of uncertainty of the estimated water level from CryoSat-2 data and the agreement with in situ data. The data quality is compared to conventional low resolution mode (LRM) altimetry products from...... Envisat, and the performance as a function of the lake area is tested. Based on a sample of 145 lakes with areas ranging from a few to several thousand km2, the CryoSat-2 results show an overall superior performance. For lakes with an area below 100 km2, the uncertainty of the lake levels is only half...

  12. Towards Disentangling Natural and Anthropogenic GHG Fluxes from Space - The CarbonSat Earth Explorer 8 Candidate Mission

    Science.gov (United States)

    Bovensmann, Heinrich

    2015-04-01

    CarbonSat was selected by ESA as one of two candidates for the Earth Explorer Opportunity mission (EE8). Understanding and quantifying climate feedback and forcing mechanisms involving the two most important anthropogenic greenhouse gases, CO2 and CH4, requires the discrimination of natural and anthropogenic CO2 and CH4 fluxes globally, with regional to local spatial scale resolution. The objective of the CarbonSat mission is therefore to quantify natural and anthropogenic sources and sinks of CO2 and CH4. The unique feature of the CarbonSat mission concept is its 'GHG imaging capability', which is achieved by combining high spatial resolution (6 km2) and good spatial coverage (breakthrough: 240 km swath, contiguous ground sampling). This capability enables global imaging of localized strong emission source areas such as cities, power plants, methane seeps, landfills and volcanoes and better separation of natural and anthropogenic GHG sources and sinks. The latter will be further supported by CarbonSat's ability to constrain the fluxes of CO2 exchanged to and from the land biosphere by simultaneously measuring CO2 and sun induced chlorophyll fluorescence (SIF), a process strongly associated with Gross Primary Production (GPP). Source/sink information will be derived from the retrieved atmospheric column-averaged mole fractions of CO2 and CH4 via inverse modelling. CarbonSat aims to deliver spatially-resolved time varying global estimates of dry column mixing ratios of CO2 and CH4 with high precision (~1 to 2 ppm and ~12 ppb, respectively) and rel. accuracy (~0.5 ppm and 5 ppb, respectively). Benefiting from its imaging capabilities along and across track, CarbonSat will provide at least an order of magnitude larger number of cloud-free CO2 soundings than GOSAT and OCO-2. Recent results from the scientific studies and supporting campaigns documenting the expected data quality and potential application areas will be summarised.

  13. Estimación de la cantidad de potencia suministrada por las celdas fotovoltaicas de un CubeSat

    Directory of Open Access Journals (Sweden)

    Jesús D. González Llorente

    2014-04-01

    Full Text Available Los CubeSat son pequeños satélites que, debido a las restricciones propias de sus dimensiones, tienen como única fuente de energía celdas foto-voltaicas sobre su superficie. El propósito de este artículo es estimar la cantidad máxima de potencia que puede obtenerse de estas celdas solares, de manera que sea posible realizar un balance de energía cuando se diseñan misiones espaciales con este tipo de satélites. En el escenario analizado, un CubeSat de 10cm x 10cm x 10cm (1U tiene una cara siempre orientada hacia la Tierra. Se consideran las pérdidas por el coseno del ángulo y la variación de la temperatura debido a la órbita del satélite. Para la estimación se usa un modelo matemático de las celdas solares, con el cual se calcula el punto de máxima potencia según el ángulo de incidencia de la radiación solar y la temperatura sobre una órbita baja alrededor de la Tierra. Los resultados muestran la variación de la potencia eléctrica máxima suministrada por los paneles sobre la porción iluminada de la órbita, sin considerar el albedo de la Tierra. Además de la potencia, se estiman las curvas corriente-voltaje para diferentes ubicaciones sobre la órbita del CubeSat.

  14. Evaluation of multi-mode CryoSat-2 altimetry data over the Po River against in situ data and a hydrodynamic model

    DEFF Research Database (Denmark)

    Schneider, Raphael; Tarpanelli, Angelica; Nielsen, Karina

    2018-01-01

    two novel features. (i) The radar altimeter instrument on board of CryoSat-2 is operated in three modes; two of them reduce the altimeter footprint by using Delay-Doppler processing. (ii) CryoSat-2 is placed on a distinct orbit with a repeat cycle of 369 days, leading to a drifting ground track...

  15. SAT Benchmarks: Development of a College Readiness Benchmark and Its Relationship to Secondary and Postsecondary School Performance. Research Report 2011-5

    Science.gov (United States)

    Wyatt, Jeffrey; Kobrin, Jennifer; Wiley, Andrew; Camara, Wayne J.; Proestler, Nina

    2011-01-01

    The current study was part of an ongoing effort at the College Board to establish college readiness benchmarks on the SAT[R], PSAT/NMSQT[R], and ReadiStep[TM] as well as to provide schools, districts, and states with a view of their students' college readiness. College readiness benchmarks were established based on SAT performance, using a…

  16. The SAT® Essay and College Performance: Understanding What Essay Scores Add to HSGPA and SAT. Research Report 2012-9 (REV: 4-2013)

    Science.gov (United States)

    Shaw, Emily J.; Kobrin, Jennifer L.

    2013-01-01

    This study examines the relationship between students' SAT essay scores and college outcomes, including first-year grade point average (FYGPA) and first-year English course grade average (FY EngGPA), overall and by various demographic and academic performance subgroups. Results showed that the SAT essay score has a positive relationship with both…

  17. SAT Scores, 2013-14: Wake County Public School System (WCPSS). Measuring Up. D&A Report No. 14.14

    Science.gov (United States)

    Gilleland, Kevin; Muli, Juliana

    2014-01-01

    The SAT is a national college entrance examination offered by the College Board and consists of three parts: Mathematics, Critical Reading, and Writing. The top score for each part is 800, for a total possible score of 2400. Colleges use SAT scores, in conjunction with other tools, to measure students' potential for success at the postsecondary…

  18. Complete Genome Sequences of Four Foot-and-Mouth Disease Viruses of Serotype South African Territories 1 (SAT 1), Topotype X, Isolated from Cattle in Nigeria in 2015.

    Science.gov (United States)

    Vandenbussche, Frank; Mathijs, Elisabeth; Ularamu, Hussaini G; Ehizibolo, David O; Haegeman, Andy; Lefebvre, David; Lazarus, David D; Wungak, Yiltawe S; De Vleeschauwer, Annebel R; Van Borm, Steven; De Clercq, Kris

    2017-10-19

    The complete genome sequences of four foot-and-mouth disease viruses of South African territories 1 (SAT 1) serotype are reported. These viruses originate from an outbreak in Nigeria in 2015 and belong to the novel SAT 1 topotype X from the west and central African virus pool. Copyright © 2017 Vandenbussche et al.

  19. COVE, MARINA, and the Future of On-Board Processing (OBP) Platforms for CubeSat Science Missions

    Science.gov (United States)

    Pingree, P.; Bekker, D. L.; Bryk, M.; DeLucca, J.; Franklin, B.; Hancock, B.; Klesh, A. T.; Meehan, C.; Meshkaty, N.; Nichols, J.; Peay, C.; Rider, D. M.; Werne, T.; Wu, Y.

    2012-12-01

    The CubeSat On-board processing Validation Experiment (COVE), JPL's first CubeSat payload launched on October 28, 2011, features the Xilinx Virtex-5QV Single event Immune Reconfigurable FPGA (SIRF). The technology demonstration mission was to validate the SIRF device running an on-board processing (OBP) algorithm developed to reduce the data set by 2-orders of magnitude for the Multi-angle SpectroPolarimetric Imager (MSPI), an instrument under development at JPL (PI: D. Diner). COVE has a single data interface to the CubeSat flight computer that is used to transfer a static image taken from the CubeSat camera and store it to local memory where the FPGA then reads it to run the algorithm on it. In the next generation COVE design, called MARINA, developed for the GRIFEX CubeSat project, the OBP board is extended, using rigid-flex PCB technology, to provide an interface to a JPL-developed Read-Out Integrated Circuit (ROIC) hybridized to a detector developed by Raytheon. In this configuration the focal plane array (FPA) data can be streamed directly to the FPGA for data processing or for storage to local memory. The MARINA rigid-flex PCB design is integrated with a commercial camera lens to create a 1U instrument payload for integration with a CubeSat under development by the University of Michigan and planned for launch in 2014. In the GRIFEX technology demonstration, the limited on-board storage capacity is filled by high-rate FPA data in less than a second. The system is also limited by the CubeSat downlink data rate and several ground station passes are required to transmit this limited amount of data. While this system is sufficient to validate the ROIC technology on-orbit, the system cannot be operated in a way to perform continuous science observations due to the on-board storage and data downlink constraints. In order to advance the current platform to support sustained science observations, more on-board storage is needed. Radiation tolerant memory

  20. Lazy Clause Generation: Combining the Power of SAT and CP (and MIP?) Solving

    Science.gov (United States)

    Stuckey, Peter J.

    Finite domain propagation solving, the basis of constraint programming (CP) solvers, allows building very high-level models of problems, and using highly specific inference encapsulated in complex global constraints, as well as programming the search for solutions to take into account problem structure. Boolean satisfiability (SAT) solving allows the construction of a graph of inferences made in order to determine and record effective nogoods which prevent the searching of similar parts of the problem, as well as the determination of those variables which form a tightly connected hard part of the problem, thus allowing highly effective automatic search strategies concentrating on these hard parts. Lazy clause generation is a hybrid of CP and SAT solving that combines the strengths of the two approaches. It provides state-of-the-art solutions for a number of hard combinatorial optimization and satisfaction problems. In this invited talk we explain lazy clause generation, and explore some of the many design choices in building such a hybrid system, we also discuss how to further incorporate mixed integer programming (MIP) solving to see if we can also inherit its advantages in combinatorial optimization.

  1. Production and characterization of a new antibacterial peptide obtained from Aeribacillus pallidus SAT4

    Directory of Open Access Journals (Sweden)

    Syed Aun Muhammad

    2015-12-01

    Full Text Available A novel thermophilic bacterial strain of the genus Aeribacillus was isolated from Thar Dessert Pakistan. This strain showed significant antibacterial activity against Micrococcus luteus, Staphylococcus aureus, and Pseudomonas aeruginosa. The strain coded as ‘SAT4’ resembled with Aeribacillus pallidus in the morphological, biochemical and molecular tests. The production of antibacterial metabolites by SAT4 was optimized. These active metabolites were precipitated by 50% ammonium sulphate and purified through sephadex G-75 gel permeation chromatography and reverse phase HPLC. The molecular weight of 37 kDa was examined by SDS-PAGE. The structural elucidation of the purified product was studied by FTIR, 1H and 13C NMR. The X-ray diffractions study showed that the crystals belonged to the primitive orthorhombic lattice (a = 12.137, b = 13.421, c = 14.097 Å and 3D structure (proposed name: Aeritracin was determined. This new peptide antibacterial molecule can get a position in pharmaceutical and biotechnological industrial research.

  2. Adaptive fuzzy logic controller with direct action type structures for InnoSAT attitude control system

    Science.gov (United States)

    Bakri, F. A.; Mashor, M. Y.; Sharun, S. M.; Bibi Sarpinah, S. N.; Abu Bakar, Z.

    2016-10-01

    This study proposes an adaptive fuzzy controller for attitude control system (ACS) of Innovative Satellite (InnoSAT) based on direct action type structure. In order to study new methods used in satellite attitude control, this paper presents three structures of controllers: Fuzzy PI, Fuzzy PD and conventional Fuzzy PID. The objective of this work is to compare the time response and tracking performance among the three different structures of controllers. The parameters of controller were tuned on-line by adjustment mechanism, which was an approach similar to a PID error that could minimize errors between actual and model reference output. This paper also presents a Model References Adaptive Control (MRAC) as a control scheme to control time varying systems where the performance specifications were given in terms of the reference model. All the controllers were tested using InnoSAT system under some operating conditions such as disturbance, varying gain, measurement noise and time delay. In conclusion, among all considered DA-type structures, AFPID controller was observed as the best structure since it outperformed other controllers in most conditions.

  3. Detection and Characterization of Ship Targets Using CryoSat-2 Altimeter Waveforms

    Directory of Open Access Journals (Sweden)

    Jesús Gómez-Enri

    2016-02-01

    Full Text Available This article describes an investigation of the new possibilities offered by SAR altimetry compared with conventional altimetry in the detection and characterization of non-ocean targets. We explore the capabilities of the first SAR altimeter installed on the European Space Agency satellite CryoSat-2 for the detection and characterization of ships. We propose a methodology for the detection of anomalous targets in the radar signals, based on the advantages of SAR/Doppler processing over conventional altimetry. A simple metric is proposed for the automatic detection and separation of ship targets; additional geometric considerations are introduced, to assess the compatibility between the structures detected and the actual location and characteristics of the ships observed. A test-case is presented with multiple targets that are confirmed as large vessels cruising in the proximity of a CryoSat-2 track crossing the Alboran Sea (Western Mediterranean. The presence and position of these ships at the time of satellite passage have been corroborated by the data retrieved from the Automatic Information System database. A principal motive for this research is the future altimetry missions that will provide global SAR coverage (e.g., Sentinel-3. This methodology may complement the existing tracking systems, with particular reference to the capability of compiling global statistics based on freely available data.

  4. Early In-orbit Performance of Scanning Sky Monitor Onboard AstroSat

    Science.gov (United States)

    Ramadevi, M. C.; Ravishankar, B. T.; Sitaramamurthy, N.; Meena, G.; Singh, Brajpal; Jain, Anand; Yadav, Reena; Agarwal, Anil; Babu, V. Chandra; Kumar; Kushwaha, Ankur; Vaishali, S.; Iyer, Nirmal Kumar; Nandi, Anuj; Girish, V.; Agarwal, Vivek Kumar; Seetha, S.; Bhattacharya, Dipankar; Balaji, K.; Kumar, Manoj; Kulshresta, Prashanth

    2017-06-01

    We report the in-orbit performance of Scanning Sky Monitor (SSM) onboard AstroSat. The SSM operates in the energy range 2.5 to 10 keV and scans the sky to detect and locate transient X-ray sources. This information of any interesting phenomenon in the X-ray sky as observed by SSM is provided to the astronomical community for follow-up observations. Following the launch of AstroSat on 28th September, 2015, SSM was commissioned on October 12th, 2015. The first power ON of the instrument was with the standard X-ray source, Crab in the field-of-view. The first orbit data revealed the basic expected performance of one of the detectors of SSM, SSM1. Following this in the subsequent orbits, the other detectors were also powered ON to find them perform in good health. Quick checks of the data from the first few orbits revealed that the instrument performed with the expected angular resolution of 12' × 2.5° and effective area in the energy range of interest. This paper discusses the instrument aspects along with few on-board results immediately after power ON.

  5. CubeSats in Hydrology: Ultra-High Resolution Insights into Vegetation Dynamics and Terrestrial Evaporation

    KAUST Repository

    McCabe, Matthew

    2017-12-01

    Satellite-based remote sensing has generally necessitated a trade-off between spatial resolution and temporal frequency, affecting the capacity to observe fast hydrological processes and rapidly changing land surface conditions. An avenue for overcoming these spatiotemporal restrictions is the concept of using constellations of satellites, as opposed to the mission focus exemplified by the more conventional space-agency approach to earth observation. Referred to as CubeSats, these platforms offer the potential to provide new insights into a range of earth system variables and processes. Their emergence heralds a paradigm shift from single-sensor launches to an operational approach that envisions tens to hundreds of small, lightweight and comparatively inexpensive satellites placed into a range of low earth orbits. Although current systems are largely limited to sensing in the optical portion of the electromagnetic spectrum, we demonstrate the opportunity and potential that CubeSats present the hydrological community via the retrieval of vegetation dynamics and terrestrial evaporation and foreshadow future sensing capabilities.

  6. Mothership of Asteroid CubeSats - Enabling Low Cost Swarm Based Investigations of Small Bodies

    Science.gov (United States)

    DiCorcia, J. D.; Ernst, S. M.; Gump, D.; Owens, A.; Lewis, J. S.; Foulds, C.; Faber, D.

    2014-12-01

    Deep Space Industries is under contract to NASA to evaluate options for secondary spacecraft in support of the Asteroid Redirect Mission. One concept to enable broad participation by the scientific community is the Mothership of Asteroid CubeSats to deliver third-party experiments and sensors to a near Earth asteroid. The Mothership service includes delivery of nanosats built by a variety of non-DSI researchers, communications relay to Earth, and visuals of the asteroid surface and surrounding area. This service allows researchers to house their instruments in a low-cost nanosat body that does not require the high-performance propulsion or deep space communications capabilities that otherwise would be required for an asteroid mission. This enables organizations with relatively low operating budgets to closely examine an asteroid with highly specialized sensors of their own choosing. In addition, the Mothership and its deployed nanosats can offer a platform for instruments, that need to be distributed over multiple spacecraft. The Mothership would be designed to carry a variety of form factors, from chipsats to 1U to 8U CubeSats. The initial missions would begin as early as fourth quarter 2017 and continue through 2018-19. Special interest groups are being conducted for gathering input from the small body research community.

  7. Impacts of Different Aerosol Types on Convective Cloud as Observed by CALIPSO/CloudSat Satellites

    Science.gov (United States)

    Jiang, J. H.; Huang, L.; Su, H.

    2016-12-01

    A major uncertainty in the study of aerosol effects on climate is how different types of aerosol affect the properties of different types of clouds. This study takes full advantage of collocated measurements over the globe from CloudSat/CALIPSO and other A-Train satellites to characterize the influence of various aerosol types on convective clouds. The occurrence frequency of six different types of aerosol (i.e., clean marine, dust, polluted continental, clean continental, polluted dust, and smoke) in each target region, as well as their probability density function, vertical and seasonal variations are determined using CALIPSO observations. The effects of different aerosol types on cloud vertical structure, cloud water content and cloud particle effective radius are investigated using collocated CloudSat and CALIPSO profile data. The influence of meteorological conditions on clouds is distinguished from aerosol effects using multi-variable composite analysis. The results will improve our understanding of the aerosol-cloud-climate interactions and potentially help to reduce uncertainties in climate change predictions.

  8. The Application of the Logo Language for Future Astronomical PocketQubes and CubeSats

    Science.gov (United States)

    Jernigan, J. Garrett

    2014-06-01

    The PocketQube T-LogoQube was a successful test of a Logo based system for future astronomical CubeSats. The flight and ground software for T-LogoQube is based on the Logo programing language. This flight software is the first use of the Logo language for the control of any satellite. The T-LogoQube team is compised of ~50 people (professional mentors, faculty, and students). The T-LogoQube uLogo based flight system acheived the following goals:(1) Transmission of fours types of packet data with the RFM22B transceiver.(2) Ability to control T-LogoQube with a "one line uLogo program".(3) The uLogo VM includes a unigue time stamp for all data.(4) Past beacon packets are telemetered for a history of T-LogoQube.(5) Realtime flight analysis of the Magnetometer to measure spin rate on orbit(6) Ability to upload new uLogo code to extend the on orbit operation.(7) Single torque coil to point the T-LogoQube spin axis in any direction(8) Detection and ability to correct SEUsWe will present evolution of Logo for future CubeSats for space based astronomy projects.

  9. BurstCube: A CubeSat for Gravitational Wave Counterparts

    Science.gov (United States)

    Perkins, Jeremy S.; Racusin, Judith; Briggs, Michael; de Nolfo, Georgia; Caputo, Regina; Krizmanic, John; McEnery, Julie E.; Shawhan, Peter; Morris, David; Connaughton, Valerie; Kocevski, Dan; Wilson-Hodge, Colleen A.; Hui, Michelle; Mitchell, Lee; McBreen, Sheila

    2018-01-01

    We present BurstCube, a novel CubeSat that will detect and localize Gamma-ray Bursts (GRBs). BurstCube is a selected mission that will detect long GRBs, attributed to the collapse of massive stars, short GRBs (sGRBs), resulting from binary neutron star mergers, as well as other gamma-ray transients in the energy range 10-1000 keV. sGRBs are of particular interest because they are predicted to be the counterparts of gravitational wave (GW) sources soon to be detectable by LIGO/Virgo. BurstCube contains 4 CsI scintillators coupled with arrays of compact low-power Silicon photomultipliers (SiPMs) on a 6U Dellingr bus, a flagship modular platform that is easily modifiable for a variety of 6U CubeSat architectures. BurstCube will complement existing facilities such as Swift and Fermi in the short term, and provide a means for GRB detection, localization, and characterization in the interim time before the next generation future gamma-ray mission flies, as well as space-qualify SiPMs and test technologies for future use on larger gamma-ray missions. The ultimate configuration of BurstCube is to have a set of ~10 BurstCubes to provide all-sky coverage to GRBs for substantially lower cost than a full-scale mission.

  10. Model predictive and reallocation problem for CubeSat fault recovery and attitude control

    Science.gov (United States)

    Franchi, Loris; Feruglio, Lorenzo; Mozzillo, Raffaele; Corpino, Sabrina

    2018-01-01

    In recent years, thanks to the increase of the know-how on machine-learning techniques and the advance of the computational capabilities of on-board processing, expensive computing algorithms, such as Model Predictive Control, have begun to spread in space applications even on small on-board processor. The paper presents an algorithm for an optimal fault recovery of a 3U CubeSat, developed in MathWorks Matlab & Simulink environment. This algorithm involves optimization techniques aiming at obtaining the optimal recovery solution, and involves a Model Predictive Control approach for the attitude control. The simulated system is a CubeSat in Low Earth Orbit: the attitude control is performed with three magnetic torquers and a single reaction wheel. The simulation neglects the errors in the attitude determination of the satellite, and focuses on the recovery approach and control method. The optimal recovery approach takes advantage of the properties of magnetic actuation, which gives the possibility of the redistribution of the control action when a fault occurs on a single magnetic torquer, even in absence of redundant actuators. In addition, the paper presents the results of the implementation of Model Predictive approach to control the attitude of the satellite.

  11. Arctic Winter Thin Ice Clouds Using RAMS, CloudSat, and CALIPSO

    Science.gov (United States)

    Seigel, R. B.; Stephens, G. L.; Cotton, W. R.; Carrio, G. G.; Blanchet, J.

    2008-12-01

    The Polar regions are an integral part of Earth's energy budget, however they are poorly understood mainly due to their remoteness and lack of observations. The recent launch of two successful satellites, CloudSat and CALIPSO, into the A-Train constellation are providing excellent insight into wintertime clouds and precipitation at the Poles. One distinguishable characteristic seen from satellite data during Arctic winter and spring is an optically thin cloud containing ice crystals large enough to precipitate out. These "thin ice clouds" (TIC) occur in regions most affected by anthropogenic pollution. It is hypothesized that the anthropogenic pollution, likely sulfuric acid, coat the available ice forming nuclei (IN) and render them as inactive particles. Therefore, the effective IN concentrations are reduced in these regions and there is less competition for the same available moisture and large ice crystals form in relatively small concentrations. The ice crystals grow large enough for fall-out and dehydrates the Arctic atmosphere. We use Colorado State University's Regional Atmospheric Modeling System (RAMS) configured as a large eddy simulation (LES) version to simulate these TIC's. RAMS contains three grids with the finest resolution of 50m, which can adequately resolve all relevant microphysical processes. By performing sensitivity experiments to recreate the observed microphysical quantities based on both CloudSat and CALIPSO, we extract the initial conditions to further understand the potential for precipitation dehydration and the effects of aerosol on this process.

  12. Explaining Violent Extremism for Subgroups by Gender and Immigrant Background, Using SAT as a Framework

    Directory of Open Access Journals (Sweden)

    Nele Schils

    2014-10-01

    Full Text Available The principal object of this paper is to study the effects of extremist propensity, exposure to extremist moral settings and their interaction effect on political violence in sub groups by gender and immigrant background. The situational action theory, as outlined by Wikström is used as a framework. Although previous studies have found empirical evidence for this interaction effect in the light of general offending, no study so far has applied SAT to the study of violent extremism. In doing so, we will also address the stability of the interaction effect by gender and immigrant background. The present study is based on a large web survey on self-reported political violence as a measure for violent extremism. Strong support is found for the hypothesis that the effect of exposure to violent extremist moral settings is depending on the strength or weakness of individual violent extremist propensity. This indicates that exposure to violent extremist moral settings has the strongest effect on political violence for individuals with a high propensity to violent extremism. These results imply that SAT can be used to as a framework to explain individual violent extremism. This pattern is found for boys and girls of both native (Belgian and immigrant background.

  13. CryoSat Plus for Oceans - analysis of the state-of-the-art

    Science.gov (United States)

    Naeije, Marc; Gommenginger, Christine; Moreau, Thomas; Cotton, David; Benveniste, Jerome; Dinardo Dinardo, Salvatore

    2013-04-01

    The CryoSat Plus for Oceans (CP4O) project is an ESA initiative carried out by a European wide consortium of altimetry experts. It aims to build a sound scientific basis for new scientific and operational applications of data coming from CryoSat-2 over the open ocean, polar ocean, coastal seas and for seafloor mapping. It also generates and evaluates new methods and products that will enable the full exploitation of the capabilities of the CryoSat-2 SIRAL altimeter, and extend their application beyond the initial mission objectives. It therefore also acts as a preparation for the upcoming Sentinel and Jason SAR enabled altimetry missions. In this paper we address the review of the CryoSat state-of-the-art, relevant current initiatives, algorithms, models and Earth Observation based products and datasets that are relevant in the Cryosat+ ocean theme. Compared to conventional (pulse-limited) altimeter missions, Cryosat-2 is not a dedicated platform for ocean research: typically the microwave radiometer (MWR) for wet tropospheric corrections is lacking, as is the direct measurement of the first order ionospheric effect by means of a dual-frequency altimeter. Also the orbit of Cryosat-2 has a rather long repetition period, unsuited for collinear tracks analyses. These three particular features have been studied already in the HERACLES project on the eve of the first CryoSat launch. We revisit the outcome of this study, update to current understanding and perception, and ultimately develop what was, is and will be proposed in these problem areas. Clearly, we question the standard ionosphere corrections, the wet troposphere corrections and the accuracy of the mean sea surface (MSS) underlying the accuracy of derived sea level anomalies. In addition, Cryosat-2 provides the first innovative altimeter with SAR and SARIn modes. This raises the direct problem of "how to process these data", simply because this has not been done before. Compared to pulse-limited altimetry it

  14. Evolutionary analysis of foot-and-mouth disease virus serotype SAT 1 isolates from east africa suggests two independent introductions from southern africa

    DEFF Research Database (Denmark)

    Sangula, Abraham K.; Belsham, Graham; Muwanika, Vincent B.

    2010-01-01

    Background: In East Africa, foot-and-mouth disease virus serotype SAT 1 is responsible for occasional severe outbreaks in livestock and is known to be maintained within the buffalo populations. Little is known about the evolutionary forces underlying its epidemiology in the region. To enhance our...... appreciation of the epidemiological status of serotype SAT 1 virus in the region, we inferred its evolutionary and phylogeographic history by means of genealogy-based coalescent methods using 53 VP1 coding sequences covering a sampling period from 1948-2007. Results: The VP1 coding sequence of 11 serotype SAT...... 1 FMD viruses from East Africa has been determined and compared with known sequences derived from other SAT 1 viruses from sub-Saharan Africa. Purifying (negative) selection and low substitution rates characterized the SAT 1 virus isolates in East Africa. Two virus groups with probable independent...

  15. Glyoxylate is a substrate of the sulfate-oxalate exchanger, sat-1, and increases its expression in HepG2 cells.

    Science.gov (United States)

    Schnedler, Nina; Burckhardt, Gerhard; Burckhardt, Birgitta C

    2011-03-01

    Hyperoxaluria is a major problem causing nephrolithiasis. Little is known about the regulation of oxalate transport from the liver, the main organ for oxalate synthesis, into the circulation. Since the sulfate anion transporter-1(sat-1) is present in the sinusoidal membrane of hepatocytes and translocates oxalate, its impact on increased oxalate synthesis was studied. Sat-1 expressing oocytes were used for cis-inhibition, trans-stimulation, and efflux experiments with labelled sulfate and oxalate to demonstrate the interactions of oxalate, glyoxylate, and glycolate with sat-1. HepG2 cells were incubated with oxalate and its precursors (glycine, hydroxyproline, glyoxylate, and glycolate). Changes in endogenous sat-1 mRNA-expression were examined using real-time PCR. After incubation of HepG2 cells in glyoxylate, sat-1 protein-expression was analysed by Western blotting, and sulfate uptake into HepG2 cells was measured. RT-PCR was used to screen for mRNA of other transporters. While oxalate and glyoxylate inhibited sulfate uptake, glycolate did not. Sulfate and oxalate uptake were trans-stimulated by glyoxylate but not by glycolate. Glyoxylate enhanced sulfate efflux. Glyoxylate was the only oxalate precursor stimulating sat-1 mRNA-expression. After incubation of HepG2 cells in glyoxylate, both sat-1 protein-expression and sulfate uptake into the cells increased. mRNA-expression of other transporters in HepG2 cells was not affected by glyoxylate treatment. The oxalate precursor glyoxylate was identified as a substrate of sat-1. Upregulated expression of sat-1 mRNA and of a functional sat-1 protein indicates that glyoxylate may be responsible for the elevated oxalate release from hepatocytes observed in hyperoxaluria. Copyright © 2010 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

  16. A hydro-optical model for deriving water quality variables from satellite images (HydroSat): A case study of the Nile River demonstrating the future Sentinel-2 capabilities

    NARCIS (Netherlands)

    Salama, M.; Radwan, M.; van der Velde, R.

    2012-01-01

    This paper describes a hydro-optical model for deriving water quality variables from satellite images, hereafter HydroSat. HydroSat corrects images for atmospheric interferences and simultaneously retrieves water quality variables. An application of HydroSat to Landsat Enhanced Thematic Mapper (ETM)

  17. Physical training of teaching staff at higher educational establishment of the Ministry of Internal Affairs of Ukraine and attitude of officers-instructors to its improvement

    Directory of Open Access Journals (Sweden)

    Bezpaliy S.M.

    2012-08-01

    Full Text Available The attitude of teaching staff to the modern state of organizing and conducting physical training at higher educational establishment of the Ministry of Internal Affairs of Ukraine and directions of its improvement is shown. 126 officers-instructors took part іn an experiment in age 30-50 years old. The questioning was conducted after an author questionnaire. Тhe insufficient efficiency of the operating system of physical training of teaching staff at higher educational establishment has been confirmed and the reasons of low level of physical preparedness and health of officers-instructors have been exposed. It is definite, that about 50% officers-instructors are skipped the employments on physical training systematically. It is set, that principal reasons of admissions of employments are: absence of time (70,7%, unclear planning of employments (11,9%, large volume of tasks of everyday activity (9,5%. It is sat, that officers-instructors desire to be regularly engaged in physical exercises and sport, the advantage is given by independent employment in the mode of day, directed on the improvement of general physical preparedness.

  18. National Board for Higher Mathematics–Grants for Participating in ...

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 10; Issue 10. National Board for Higher Mathematics – Grants for Participating in ICM 2006, Madrid. Information and Announcements Volume 10 Issue 10 October 2005 pp 95-95 ...

  19. EntrySat: A 3U CubeStat to study the reentry atmospheric environment

    Science.gov (United States)

    Anthony, Sournac; Raphael, Garcia; David, Mimoun; Jeremie, Chaix

    2016-04-01

    ISAE France Entrysat has for main scientific objective the study of uncontrolled atmospheric re-entry. This project, is developed by ISAE in collaboration with ONERA and University of Toulouse, is funded by CNES, in the overall frame of the QB50 project. This nano-satellite is a 3U Cubesat measuring 34*10*10 cm3, similar to secondary debris produced during the break up of a spacecraft. EntrySat will collect the external and internal temperatures, pressure, heat flux, attitude variations and drag force of the satellite between ≈150 and 90 km before its destruction in the atmosphere, and transmit them during the re-entry using the IRIDIUM satellite network. The result will be compared with the computations of MUSIC/FAST, a new 6-degree of freedom code developed by ONERA to predict the trajectory of space debris. In order to fulfil the scientific objectives, the satellite will acquire 18 re-entry sensors signals, convert them and compress them, thanks to an electronic board developed by ISAE students in cooperation with EREMS. In order to transmit these data every second during the re-entry phase, the satellite will use an IRIDIUM connection. In order to keep a stable enough attitudes during this phase, a simple attitude orbit and control system using magnetotorquers and an inertial measurement unit (IMU) is developed at ISAE by students. A commercial GPS board is also integrated in the satellite into Entry Sat to determine its position and velocity which are necessary during the re-entry phase. This GPS will also be used to synchronize the on-board clock with the real-time UTC data. During the orbital phase (≈2 year) EntrySat measurements will be recorded transmitted through a more classical "UHF/VHF" connection. Preference for presentation: Poster Most suitable session: Author for correspondence: Dr Raphael F. Garcia ISAE 10, ave E. Belin, 31400 Toulouse, France Raphael.GARCIA@isae.fr +33 5 61 33 81 14

  20. NASA's Space Launch System: Deep-Space Deployment for SmallSats

    Science.gov (United States)

    Schorr, Andy

    2017-01-01

    From its upcoming first flight, NASA's new Space Launch System (SLS) will represent a game-changing opportunity for smallsats. On that launch, which will propel the Orion crew vehicle around the moon, the new exploration-class launch vehicle will deploy 13 6U CubeSats into deep-space, where they will continue to a variety of destinations to perform diverse research and demonstrations. Following that first flight, SLS will undergo the first of a series of performance upgrades, increasing its payload capability to low Earth orbit from 70 to 105 metric tons via the addition of a powerful upper stage. With that change to the vehicle's architecture, so too will its secondary payload accommodation for smallsats evolve, with current plans calling for a change from the first-flight limit of 6U to accommodating a range of sizes up to 27U and potentially ESPA-class payloads. This presentation will provide an overview and update on the first launch of SLS and the secondary payloads it will deploy. Currently, flight hardware has been produced for every element of the vehicle, testing of the vehicle's propulsion elements has been ongoing for years, and structural testing of its stages has begun. Major assembly and testing of the Orion Stage Adapter, including the secondary payload accommodations, will be completed this year, and the structure will then be shipped to Kennedy Space Center for integration of the payloads. Progress is being made on those CubeSats, which will include studies of asteroids, Earth, the sun, the moon, and the impacts of radiation on organisms in deep space. They will feature revolutionary innovations for smallsats, including demonstrations of use of a solar sail as propulsion for a rendezvous with an asteroid, and the landing of a CubeSat on the lunar surface. The presentation will also provide an update on progress of the SLS Block 1B configuration that will be used on the rocket's second flight, a discussion of planned secondary payload accommodations

  1. Drag De-Orbit Device: A New Standard Re-Entry Actuator for CubeSats

    Science.gov (United States)

    Guglielmo, David; Omar, Sanny R.; Bevilacqua, Riccardo

    2017-01-01

    With the advent of CubeSats, research in Low Earth Orbit (LEO) becomes possible for universities and small research groups. Only a handful of launch sites can be used, due to geographical and political restrictions. As a result, common orbits in LEO are becoming crowded due to the additional launches made possible by low-cost access to space. CubeSat design principles require a maximum of a 25-year orbital lifetime in an effort to reduce the total number of spacecraft in orbit at any time. Additionally, since debris may survive re-entry, it is ideal to de-orbit spacecraft over unpopulated areas to prevent casualties. The Drag Deorbit Device (D3) is a self-contained targeted re-entry subsystem intended for CubeSats. By varying the cross-wind area, the atmospheric drag can be varied in such a way as to produce desired maneuvers. The D3 is intended to be used to remove spacecraft from orbit to reach a desired target interface point. Additionally, attitude stabilization is performed by the D3 prior to deployment and can replace a traditional ADACS on many missions.This paper presents the hardware used in the D3 and operation details. Four stepper-driven, repeatedly retractable booms are used to modify the cross-wind area of the D3 and attached spacecraft. Five magnetorquers (solenoids) over three axes are used to damp rotational velocity. This system is expected to be used to improve mission flexibility and allow additional launches by reducing the orbital lifetime of spacecraft.The D3 can be used to effect a re-entry to any target interface point, with the orbital inclination limiting the maximum latitude. In the chance that the main spacecraft fails, a timer will automatically deploy the booms fully, ensuring the spacecraft will at the minimum reenter the atmosphere in the minimum possible time, although not necessarily at the desired target interface point. Although this does not reduce the risk of casualties, the 25-year lifetime limit is still respected, allowing

  2. INSPIRE and MarCO - Technology Development for the First Deep Space CubeSats

    Science.gov (United States)

    Klesh, Andrew

    2016-07-01

    INSPIRE (Interplanetary NanoSpacecraft Pathfinder In a Relevant Environment) and MarCO (Mars Cube One) will open the door for tiny spacecraft to explore the solar system. INSPIRE serves as a trailblazer, designed to demonstrate new technology needed for deep space. MarCO will open the door for NanoSpacecraft to serve in support roles for much larger primary missions - in this case, providing a real-time relay of for the InSight project and will likely be the first CubeSats to reach deep space. Together, these four spacecraft (two for each mission) enable fundamental science objectives to be met with tiny vehicles. Originally designed for a March, 2016 launch with the InSight mission to Mars, the MarCO spacecraft are now complete and in storage. When launched with the InSight lander from Vandenberg Air Force Base, the spacecraft will begin a 6.5 month cruise to Mars. Soon after InSight itself separates from the upper stage of the launch vehicle, the two MarCO CubeSats will deploy and independently fly to Mars to support telecommunications relay for InSight's entry, descent, and landing sequence. These spacecraft will have onboard capability for deep space trajectory correction maneuvers; high-speed direct-to-Earth & DSN-compatible communications; an advanced navigation transponder; a large deployable reflect-array high gain antenna; and a robust software suite. This talk will present an overview of the INSPIRE and MarCO projects, including a concept of operations, details of the spacecraft and subsystem design, and lessons learned from integration and test. Finally, the talk will outline how lessons from these spacecraft are already being utilized in the next generation of interplanetary CubeSats, as well as a brief vision of their applicability for solar system exploration. The research described here was carried out at the Jet Propulsion Laboratory, Caltech, under a contract with the National Aeronautics and Space Administration (NASA).

  3. NEUDOSE: A CubeSat Mission for Dosimetry of Charged Particles and Neutrons in Low-Earth Orbit.

    Science.gov (United States)

    Hanu, A R; Barberiz, J; Bonneville, D; Byun, S H; Chen, L; Ciambella, C; Dao, E; Deshpande, V; Garnett, R; Hunter, S D; Jhirad, A; Johnston, E M; Kordic, M; Kurnell, M; Lopera, L; McFadden, M; Melnichuk, A; Nguyen, J; Otto, A; Scott, R; Wagner, D L; Wiendels, M

    2017-01-01

    During space missions, astronauts are exposed to a stream of energetic and highly ionizing radiation particles that can suppress immune system function, increase cancer risks and even induce acute radiation syndrome if the exposure is large enough. As human exploration goals shift from missions in low-Earth orbit (LEO) to long-duration interplanetary missions, radiation protection remains one of the key technological issues that must be resolved. In this work, we introduce the NEUtron DOSimetry & Exploration (NEUDOSE) CubeSat mission, which will provide new measurements of dose and space radiation quality factors to improve the accuracy of cancer risk projections for current and future space missions. The primary objective of the NEUDOSE CubeSat is to map the in situ lineal energy spectra produced by charged particles and neutrons in LEO where most of the preparatory activities for future interplanetary missions are currently taking place. To perform these measurements, the NEUDOSE CubeSat is equipped with the Charged & Neutral Particle Tissue Equivalent Proportional Counter (CNP-TEPC), an advanced radiation monitoring instrument that uses active coincidence techniques to separate the interactions of charged particles and neutrons in real time. The NEUDOSE CubeSat, currently under development at McMaster University, provides a modern approach to test the CNP-TEPC instrument directly in the unique environment of outer space while simultaneously collecting new georeferenced lineal energy spectra of the radiation environment in LEO.

  4. A Three Degrees of Freedom Test-Bed for Nanosatellite and CubeSat Attitude Dynamics, Determination, and Control

    Science.gov (United States)

    2009-12-01

    Tactical Imaging Nano-sat Yielding Small-Cost Operations and Persistent Earth-coverage UFO UHF Follow On UHF Ultra-High Frequency USCG United...replaced by UHF Follow On ( UFO ) satellites in the 1990s. The UFO satellites are being updated and scheduled for replacement by the Mobile User

  5. Five years of coastal sea level monitoring in the Bay of Bengal with CryoSat-2

    DEFF Research Database (Denmark)

    Andersen, Ole Baltazar

    exploiting five years of CryoSat-2 data. The work is focused on the analysis of CryoSat’s performances over coastal areas with using 20Hz SAR data from SARvatore online processing toolbox. This research is also an opportunity for comparing SIRAL’s LRM and SAR modes, which have covered the same area...

  6. Predicting College Success: The Relative Contributions of Five Social/Personality Factors, Five Cognitive/Learning Factors and SAT Scores

    Science.gov (United States)

    Hannon, Brenda

    2014-01-01

    To-date, studies have examined simultaneously the relative predictive powers of two or three factors on GPA. The present study examines the relative powers of five social/personality factors, five cognitive/learning factors, and SAT scores to predict freshmen and non-freshmen (sophomores, juniors, seniors) academic success (i.e., GPA). The results…

  7. Repeated Test Taking on the SAT: The Effects of Ethnicity, Gender, Financial Aid, and High School Location

    Science.gov (United States)

    Lynch, Lian

    2012-01-01

    The purpose of this study was to determine whether there was a significant relationship between repeated test taking on the SAT and several demographic measures. These measures included ethnicity (American Indian/Alaskan Native, Asian/Asian American/Pacific Islander, Black/African American, Mexican/Mexican American, Puerto Rican, Other…

  8. Contextual Factors Associated with the Validity of SAT Scores and High School GPA for Predicting First-Year College Grades

    Science.gov (United States)

    Kobrin, Jennifer L.; Patterson, Brian F.

    2011-01-01

    Prior research has shown that there is substantial variability in the degree to which the SAT and high school grade point average (HSGPA) predict 1st-year college performance at different institutions. This article demonstrates the usefulness of multilevel modeling as a tool to uncover institutional characteristics that are associated with this…

  9. Hispanics' SAT Scores: The Influences of Level of Parental Education, Performance-Avoidance Goals, and Knowledge about Learning

    Science.gov (United States)

    Hannon, Brenda

    2015-01-01

    This study uncovers which learning (epistemic belief of learning), socioeconomic background (level of parental education, family income) or social-personality factors (performance-avoidance goals, test anxiety) mitigate the ethnic gap in SAT (Scholastic Assessment Test) scores. Measures assessing achievement motivation, test anxiety, socioeconomic…

  10. Target Practice: Reader Response Theory and Teachers' Interpretations of Students' SAT 10 Scores in Data-Based Professional Development

    Science.gov (United States)

    Atkinson, Becky M.

    2012-01-01

    The study reported in this article examines how teachers read and respond to their students' Stanford Achievement Test 10 (SAT 10) scores with the goal of investigating the assumption that data-based teaching practice is more "objective" and less susceptible to divergent teacher interpretation. The study uses reader response theory to…

  11. Validity of the SAT® for Predicting First-Year Grades: 2010 SAT Validity Sample. Statistical Report 2013-2

    Science.gov (United States)

    Patterson, Brian F.; Mattern, Krista D.

    2013-01-01

    The continued accumulation of validity evidence for the core uses of educational assessments is critical to ensure that proper inferences will be made for those core purposes. To that end, the College Board has continued to follow previous cohorts of college students and this report provides updated validity evidence for using the SAT to predict…

  12. A Proposal to Eliminate the SAT in Berkeley Admissions. Research & Occasional Paper Series: CSHE.4.16

    Science.gov (United States)

    Geiser, Saul

    2016-01-01

    The SAT is used for two purposes at the University of California. First is "eligibility": Determining whether applicants meet the minimum requirements for admission to the UC system. Second is "admissions selection": At high-demand campuses such as Berkeley, with many more eligible applicants than places available, test scores…

  13. ROC analysis of subcutaneous adipose tissue topography (SAT-Top) in female coronary heart disease patients and healthy controls.

    Science.gov (United States)

    Wallner, Sandra Johanna; Horejsi, Renate; Zweiker, Robert; Watzinger, Norbert; Möller, Reinhard; Schnedl, Wolfgang Johann; Schauenstein, Konrad; Tafeit, Erwin

    2008-06-01

    The aim of this study was to investigate whether subcutaneous adipose tissue topography (SAT-Top) is different in female CHD patients (n=26) and healthy controls (n=36) matched to age, body size, weight, and BMI. The thicknesses of SAT layers were measured by LIPOMETER at 15 specified body sites. To calculate the power of the different body sites to discriminate between CHD women and healthy controls, receiver operating characteristic (ROC) curve analysis was performed. For each parameter, sensitivity and specificity were calculated at different cutoff points. CHD women showed a significant decrease to 78.36% (p=0.012) at body site 11-front thigh, 73.10% (p=0.012) at 12-lateral thigh, 72.20% (p=0.009) at 13-rear thigh, 66.43% (pSAT thickness at each measured body site is able to discriminate between the two subject groups. The good discrimination results obtained for the present dataset are encouraging enough to recommend applying LIPOMETER SAT-Top measurements in further studies to investigate individual risks for CHD.

  14. Feasibility analysis of XSOLANTRA: A mission concept to detect exoplanets with an array of CubeSats

    Science.gov (United States)

    Banazadeh, P.; Lazio, J.; Jones, D.; Scharf, D. P.; Fowler, W.; Aladangady, C.

    Seeking “ nearby habitable worlds” was one of three science themes identified in the Astronomy Decadal Survey. Hundreds of extrasolar planets are known, but magnetic fields are likely required for these planets to be habitable. As of today, no direct constraints on the magnetic field characteristics of extrasolar planets exist. The ExtraSolar Observing Low-frequency Array of Nano Satellites for Radio Astronomy (XSOLANTRA), formerly known as XSOLARA is a feasibility study of a student designed, built, and tested micro-satellite mission to a Distant Retrograde Orbit (DRO) around Earth. XSOLANTRA will look at the Electron Cyclotron Maser Emission generated by the interaction between stellar wind and a planetary magnetosphere from which interior composition and atmospheric shielding can be inferred. The science instrument for XSOLANTRA is the entire array of fourteen CubeSats operating together as an interferometer. The fourteen CubeSats will be stacked on a SHuttle Expendable Rocket for Payload Augmentation (SHERPA) vehicle as a payload and will be deployed once arrived at DRO. A feasibility study was conducted to demonstrate that a CubeSat mission with cost of no more than $60 million is capable of detecting extrasolar planets. The study showed that a CubeSat mission within these constraints is possible; however, some questions still remain unanswered. This paper summarizes the mission concept starting from the science requirements, key mission design decisions, component level feasibility analysis and management and cost analysis.

  15. Concept, Design, and Prototyping of XSAS: A High Power Extendable Solar Array for CubeSat Applications

    Science.gov (United States)

    Senatore, Patrick; Klesh, Andrew; Zurbuchen, Thomas H.; McKague, Darren; Cutler, James

    2010-01-01

    CubeSats have proven themselves as a reliable and cost-effective method to perform experiments in space, but they are highly constrained by their specifications and size. One such constraint is the average continuous power, about 5 W, which is available to the typical CubeSat. To improve this constraint, we have developed the eXtendable Solar Array System (XSAS), a deployable solar array prototype in a CubeSat package, which can provide an average 23 W of continuous power. The prototype served as a technology demonstrator for the high risk mechanisms needed to release, deploy, and control the solar array. Aside from this drastic power increase, it is in the integration of each mechanism, their application within the small CubeSat form-factor, and the inherent passive control benefit of the deployed geometry that make XSAS a novel design. In this paper, we discuss the requirements and design process for the XSAS system and mechanical prototype, and provide qualitative and quantitative results from numerical simulations and prototype tests. We also discuss future work, including an upcoming NASA zero-gravity flight campaign, to further improve on XSAS and prepare it for future launch opportunities.

  16. AMSR-E Rainfall Subset, collocated with the CloudSat track, in HDF-EOS format V002

    Data.gov (United States)

    National Aeronautics and Space Administration — This is a subset of AMSR-E rain rat eproduct along CloudSat field of view track. The goal of the subset is to select and return AMSR-E data that are within +-100 km...

  17. PAN AIR: A computer program for predicting subsonic or supersonic linear potential flows about arbitrary configurations using a higher order panel method. Volume 4: Maintenance document (version 3.0)

    Science.gov (United States)

    Purdon, David J.; Baruah, Pranab K.; Bussoletti, John E.; Epton, Michael A.; Massena, William A.; Nelson, Franklin D.; Tsurusaki, Kiyoharu

    1990-01-01

    The Maintenance Document Version 3.0 is a guide to the PAN AIR software system, a system which computes the subsonic or supersonic linear potential flow about a body of nearly arbitrary shape, using a higher order panel method. The document describes the overall system and each program module of the system. Sufficient detail is given for program maintenance, updating, and modification. It is assumed that the reader is familiar with programming and CRAY computer systems. The PAN AIR system was written in FORTRAN 4 language except for a few CAL language subroutines which exist in the PAN AIR library. Structured programming techniques were used to provide code documentation and maintainability. The operating systems accommodated are COS 1.11, COS 1.12, COS 1.13, and COS 1.14 on the CRAY 1S, 1M, and X-MP computing systems. The system is comprised of a data base management system, a program library, an execution control module, and nine separate FORTRAN technical modules. Each module calculates part of the posed PAN AIR problem. The data base manager is used to communicate between modules and within modules. The technical modules must be run in a prescribed fashion for each PAN AIR problem. In order to ease the problem of supplying the many JCL cards required to execute the modules, a set of CRAY procedures (PAPROCS) was created to automatically supply most of the JCL cards. Most of this document has not changed for Version 3.0. It now, however, strictly applies only to PAN AIR version 3.0. The major changes are: (1) additional sections covering the new FDP module (which calculates streamlines and offbody points); (2) a complete rewrite of the section on the MAG module; and (3) strict applicability to CRAY computing systems.

  18. Design of an attitude control system for spin-axis control of a 3U CubeSat

    Science.gov (United States)

    Westfall, Alexander J.

    This paper describes the design process of developing a spin-axis control system for a 3U CubeSat, a relatively small satellite. Design requires the CubeSat to de-spin after deployment and direct its antenna to track Earth nadir position. The one degree of freedom controller is developed for the TechEdSat, which is a CubeSat with a payload that allows for the assumption that rotation pitch and yaw rates are sufficiently close to zero. Satellite torqueing disturbances are modeled with reaction wheel noise for a more complete system analysis. Sensor noise is unmodeled. Frequency domain and time domain analyses are presented; the entire system bandwidth operates at 0.08 hertz with 43.2 decibels of gain and 67.7° of phase margin. During nominal operations, pointing accuracy with perfect state knowledge assumption maintains position with steady state error of 13.7 arc seconds and oscillates by 16.7 arc seconds at a rate of 0.7 mHertz. Artificial wheel noise is injected into the model causing the pointing accuracy to drop to +/- 15 arc seconds. Environmental disturbances are modeled extensively; the magnetic field torque is the worst disturbance, at 4.2e-7 Newton-meters. A 0.2 Amp˙m2 magnetorquer dumps the excess momentum every 7.75 hours and require 1.5 hours to complete. In the deployment simulation, a 1 rotation per minute spin is arrested with no angular offset in 60 seconds. Future plans include utilizing the model to build and fly a prototype reaction wheel on a future TechEdSat mission to verify modeled expectations.

  19. Reconstructing geographical movements and host species transitions of foot-and-mouth disease virus serotype SAT 2.

    Science.gov (United States)

    Hall, Matthew D; Knowles, Nick J; Wadsworth, Jemma; Rambaut, Andrew; Woolhouse, Mark E J

    2013-10-22

    Of the three foot-and-mouth-disease virus SAT serotypes mainly confined to sub-Saharan Africa, SAT 2 is the strain most often recorded in domestic animals and has caused outbreaks in North Africa and the Middle East six times in the last 25 years, with three apparently separate events occurring in 2012. This study updates the picture of SAT 2 phylogenetics by using all available sequences for the VP1 section of the genome available at the time of writing and uses phylogeographic methods to trace the origin of all outbreaks occurring north of the Sahara since 1990 and identify patterns of spread among countries of endemicity. Transitions between different host species are also enumerated. Outbreaks in North Africa appear to have origins in countries immediately south of the Sahara, whereas those in the Middle East are more often from East Africa. The results of the analysis of spread within sub-Saharan Africa are consistent with it being driven by relatively short-distance movements of animals across national borders, and the analysis of host species transitions supports the role of the African buffalo (Syncerus caffer) as an important natural reservoir. Foot-and-mouth disease virus is a livestock pathogen of major economic importance, with seven distinct serotypes occurring globally. The SAT 2 serotype, endemic in sub-Saharan Africa, has caused a number of outbreaks in North Africa and the Middle East during the last decades, including three separate incidents in 2012. A comprehensive analysis of all available RNA sequences for SAT 2 has not been published for some years. In this work, we performed this analysis using all previously published sequences and 49 newly determined examples. We also used phylogenetic methods to infer the source country for all outbreaks occurring outside sub-Saharan Africa since 1990 and to reconstruct the spread of viral lineages between countries where it is endemic and movements between different host species.

  20. University of Colorado CubeSat Student Projects as Successful Model for Teaching Students about Engineering Practices

    Science.gov (United States)

    Palo, S. E.; Li, X.; Woods, T. N.; Kohnert, R.

    2014-12-01

    There is a long history of cooperation between students at the University of Colorado, Boulder and professional engineers and scientists at LASP, which has led to many successful space missions with direct student involvement. The recent student-led missions include the Student Nitric Oxide Explorer (SNOE, 1998 - 2002), the Student Dust Counter (SDC) on New Horizons (2006 - present), the Colorado Student Space Weather Experiment (CSSWE), being a very successful NSF CubeSat that launched in September 2012, and the NASA Miniature X-ray Solar Spectrometer (MinXSS) CubeSat (launch will be in early 2015). Students are involved in all aspects of the design, and they experience the full scope of the mission process from concept, to fabrication and test, and mission operations. A significant part of the student involvement in the CubeSat projects is gained by using the CubeSat development as a focal point for an existing two-semester course sequence in CU's Aerospace Engineering Sciences (AES) Department: the Space Hardware Design section of Graduate Projects I & II (ASEN 5018 & ASEN 6028). The goal of these courses is to teach graduate students how to design and build systems using a requirement-based approach and fundamental systems engineering practices. The two-semester sequence takes teams of about 15 students from requirements definition and preliminary design through manufacturing, integration, and testing. In addition to the design process, students learn key professional skills such as working effectively in groups, finding solutions to open-ended problems, and actually building a system to their own set of specifications. The partnership between AES and LASP allows us to include engineering professionals in the mix, thus more effectively training science and engineering students for future roles in the civilian or commercial space industry. The mentoring process with LASP engineers helps to mitigate risk of the inexperience of the students and ensures consistent