Sample records for astronomy receiver systems

  1. Ambient and Cryogenic, Decade Bandwidth, Low Noise Receiving System for Radio Astronomy Using Sinuous Antenna (United States)

    Gawande, Rohit Sudhir

    Traditionally, radio astronomy receivers have been limited to bandwidths less than an octave, and as a result multiple feeds and receivers are necessary to observe over a wide bandwidth. Next generation of instruments for radio astronomy will benefit greatly from reflector antenna feeds that demonstrate very wide instantaneous bandwidth, and exhibit low noise behavior. There is an increasing interest in wideband systems from both the cost and science point of view. A wideband feed will allow simultaneous observations or sweeps over a decade or more bandwidth. Instantaneous wide bandwidth is necessary for detection of short duration pulses. Future telescopes like square kilometer array (SKA), consisting of 2000 to 3000 coherently connected antennas and covering a frequency range of 70 MHz to 30 GHz, will need decade bandwidth single pixel feeds (SPFs) along with integrated LNAs to achieve the scientific objectives in a cost effective way. This dissertation focuses on the design and measurement of a novel decade bandwidth sinuous-type, dual linear polarized, fixed phase center, low loss feed with an integrated LNA. A decade bandwidth, low noise amplifier is specially designed for noise match to the higher terminal impedance encountered by this antenna yielding an improved sensitivity over what is possible with conventional 50 O amplifiers. The self-complementary, frequency independent nature of the planar sinuous geometry results in a nearly constant beam pattern and fixed phase center over more than a 10:1 operating frequency range. In order to eliminate the back-lobe response over such a wide frequency range, we have projected the sinuous pattern onto a cone, and a ground plane is placed directly behind the cone's apex. This inverted, conical geometry assures wide bandwidth operation by locating each sinuous resonator a quarter wavelength above the ground plane. The presence of a ground plane near a self complementary antenna destroys the self complementary nature

  2. Radio Astronomy Software Defined Receiver Project

    Energy Technology Data Exchange (ETDEWEB)

    Vacaliuc, Bogdan [ORNL; Leech, Marcus [Shirleys Bay Radio Astronomy Consortium; Oxley, Paul [Retired; Flagg, Richard [Retired; Fields, David [ORNL


    The paper describes a Radio Astronomy Software Defined Receiver (RASDR) that is currently under development. RASDR is targeted for use by amateurs and small institutions where cost is a primary consideration. The receiver will operate from HF thru 2.8 GHz. Front-end components such as preamps, block down-converters and pre-select bandpass filters are outside the scope of this development and will be provided by the user. The receiver includes RF amplifiers and attenuators, synthesized LOs, quadrature down converters, dual 8 bit ADCs and a Signal Processor that provides firmware processing of the digital bit stream. RASDR will interface to a user s PC via a USB or higher speed Ethernet LAN connection. The PC will run software that provides processing of the bit stream, a graphical user interface, as well as data analysis and storage. Software should support MAC OS, Windows and Linux platforms and will focus on such radio astronomy applications as total power measurements, pulsar detection, and spectral line studies.

  3. Software systems for astronomy

    CERN Document Server

    Conrad, Albert R


    This book covers the use and development of software for astronomy. It describes the control systems used to point the telescope and operate its cameras and spectrographs, as well as the web-based tools used to plan those observations. In addition, the book also covers the analysis and archiving of astronomical data once it has been acquired. Readers will learn about existing software tools and packages, develop their own software tools, and analyze real data sets.

  4. 47 CFR 73.6027 - Class A TV notifications concerning interference to radio astronomy, research and receiving... (United States)


    ... interference to radio astronomy, research and receiving installations. 73.6027 Section 73.6027... radio astronomy, research and receiving installations. An applicant for digital operation of an existing... astronomy, research and receiving installations. ...

  5. ASTRONOMY. (United States)

    Louisiana Arts and Science Center, Baton Rouge.


  6. Electronic warfare receivers and receiving systems

    CERN Document Server

    Poisel, Richard A


    Receivers systems are considered the core of electronic warfare (EW) intercept systems. Without them, the fundamental purpose of such systems is null and void. This book considers the major elements that make up receiver systems and the receivers that go in them.This resource provides system design engineers with techniques for design and development of EW receivers for modern modulations (spread spectrum) in addition to receivers for older, common modulation formats. Each major module in these receivers is considered in detail. Design information is included as well as performance tradeoffs o

  7. Astronomy Village: Investigating the Solar System (United States)

    Williams, Jeffrey; Croft, Steven; McGee, Steven


    The Astronomy Village: Investigating the Solar System is a new product aimed at astronomy instructional materials for middle school audiences. This multimedia development, funded by the NSF, will be suitable for curriculum supplement, presentations, and public outreach in Earth and planetary science. The presentation will highlight one of the research paths from the Village: Is there life on Mars? Students using this curriculum will solve problems in a rich environment that includes images, hands on labs, simulations, presentations, articles, and web pages. The research questions will be presented using multiple working hypothesis format.

  8. Astronomy

    CERN Document Server

    Seymour, Percy


    With a blend of exciting discoveries and important scientific theory,this innovative and readable introduction to astronomy is ideal for anyone who wants to understand what we know about the universe,and how we know it. Each chapter starts with details of a method of jow astronomers over time have observed the world,and then uses this as a springboard to discuss what they discovered,and why this was important for understanding the cosmos. The last chapter,on dark matter,also focuses on the many things we don''t yet know - reminding us that astronomy,like this book,is a fast-paced and fascinati

  9. SPHEREx: Science Opportunities for Solar System Astronomy (United States)

    Lisse, Carey Michael; SPHEREx Science Team


    SPHEREx, a mission in NASA's Medium Explorer (MIDEX) program that was selected for Phase A study in August 2017, will perform an all-sky near-infrared spectral survey between 0.75 - 5.0 µm in R = 41 filters, and with R = 135 coverage from 4.2 - 5.0 µm, reaching L ~ 19 (5-sigma).SPHEREx has high potential for solar system science. The 96-band survey will cover the entire sky 4 times over the course of 2 years, including thousands of foreground solar system asteroids, comets, Trojans, and KBOs. By canvassing the entire solar system for 2 years, SPHEREx has the potential not only to achieve a relatively complete sensitivity limited survey of the solar system's bodies, but also some capability to search for variation in these bodies over time.For example, the large legacy dataset of SPHEREx will update the WISE catalogue of asteroid sizes and albedos by providing a spectral survey of tens of thousands of bodies. It will provide spectral classification of hundreds of Trojan asteroids, allowing for direct comparison to the asteroid results. It will extend optical surveys of comet composition by dynamical type to hundreds of objects in the NIR, while determining water/dust/CO/CO2 activity vs distance. SPHEREx will also map in great temporal and spatial detail the zodiacal dust debris disk cloud that these bodies produce, providing an unprecedented level of information concerning the sources and sinks of this material.In this paper, we discuss the data release schedule and some example science studies the planetary astronomy community will be able to access using the SPHEREx database. We also outline existing plans within the SPHEREx team to develop software tools to enable easy access to the data and to conduct catalog searches, and ways in which the community can provide input to the SPHEREx Science Team on scientific studies and data/software requirements for those studies, enabling a large number of scientific studies while finding interesting targets for follow

  10. The science case for simultaneous mm-wavelength receivers in radio astronomy (United States)

    Dodson, Richard; Rioja, María J.; Jung, Taehyun; Goméz, José L.; Bujarrabal, Valentin; Moscadelli, Luca; Miller-Jones, James C. A.; Tetarenko, Alexandra J.; Sivakoff, Gregory R.


    This review arose from the European Radio Astronomy Technical Forum (ERATec) meeting held in Firenze, October 2015, and aims to highlight the breadth and depth of the high-impact science that will be aided and assisted by the use of simultaneous mm-wavelength receivers. Recent results and opportunities are presented and discussed from the fields of: continuum VLBI (observations of weak sources, astrometry, observations of AGN cores in spectral index and Faraday rotation), spectral line VLBI (observations of evolved stars and massive star-forming regions) and time domain observations of the flux variations arising in the compact jets of X-ray binaries. Our survey brings together a large range of important science applications, which will greatly benefit from simultaneous observing at mm-wavelengths. Such facilities are essential to allow these applications to become more efficient, more sensitive and more scientifically robust. In some cases without simultaneous receivers the science goals are simply unachievable. Similar benefits would exist in many other high frequency astronomical fields of research.

  11. Photographs and Classroom Response Systems in Middle School Astronomy Classes (United States)

    Lee, Hyunju; Feldman, Allan


    In spite of being readily available, photographs have played a minor and passive role in science classes. In our study, we present an active way of using photographs in classroom discussions with the use of a classroom response system (CRS) in middle school astronomy classes to teach the concepts of day-night and seasonal change. In this new…

  12. Solar System Symphony: Combining astronomy with live classical music (United States)

    Kremer, Kyle; WorldWide Telescope


    Solar System Symphony is an educational outreach show which combines astronomy visualizations and live classical music. As musicians perform excerpts from Holst’s “The Planets” and other orchestral works, visualizations developed using WorldWide Telescope and NASA images and animations are projected on-stage. Between each movement of music, a narrator guides the audience through scientific highlights of the solar system. The content of Solar System Symphony is geared toward a general audience, particularly targeting K-12 students. The hour-long show not only presents a new medium for exposing a broad audience to astronomy, but also provides universities an effective tool for facilitating interdisciplinary collaboration between two divergent fields. The show was premiered at Northwestern University in May 2016 in partnership with Northwestern’s Bienen School of Music and was recently performed at the Colburn Conservatory of Music in November 2016.

  13. Receiver System Analysis and Optimization (United States)


    for several devices from the IBM SiGe 8HP process design kit (the manufacturing process used for the MDREX project): bipolar transistor ( BJT ), spiral...of the project. Most significantly, a transistor -level simulation algorithm compatible with the system level simulation algorithm was developed. This... transistor -level simulation program simultaneously and synchronizing them at time intervals. Since the new capability allows the simulation of the entire

  14. Directional Receiver for Biomimetic Sonar System (United States)

    Guarato, Francesco; Andrews, Heather; Windmill, James F.; Jackson, Joseph; Gachagan, Anthony

    An ultrasonic localization method for a sonar system equipped with an emitter and two directional receivers and inspired by bat echolocation uses knowledge of the beam pattern of the receivers to estimate target orientation. Rousettus leschenaultii's left ear constitutes the model for the design of the optimal receiver for this sonar system and 3D printing was used to fabricate receiver structures comprising of two truncated cones with an elliptical external perimeter and a parabolic flare rate in the upper part. Measurements show one receiver has a predominant lobe in the same region and with similar attenuation values as the bat ear model. The final sonar system is to be mounted on vehicular and aerial robots which require remote control for motion and sensors for estimation of each robot's location.

  15. Global Positioning System receiver evaluation results

    Energy Technology Data Exchange (ETDEWEB)

    Byrne, R.H.


    A Sandia project currently uses an outdated Magnavox 6400 Global Positioning System (GPS) receiver as the core of its navigation system. The goal of this study was to analyze the performance of the current GPS receiver compared to newer, less expensive models and to make recommendations on how to improve the performance of the overall navigation system. This paper discusses the test methodology used to experimentally analyze the performance of different GPS receivers, the test results, and recommendations on how an upgrade should proceed. Appendices contain detailed information regarding the raw data, test hardware, and test software.



  17. Solar central receiver systems comparative economics (United States)

    Eicker, P. J.


    Several major conceptual design studies of solar central receiver systems and components were completed in the last year. The results of these studies were used to compare the projected cost of electric power generation using central receiver systems with that of more conventional power generation. The cost estimate for a molten salt central receiver system is given. Levelized busbar energy cost is shown as a function of annual capacity factor indicating the fraction of the cost due to each of the subsystems. The estimated levelized busbar energy cost for a central receiver (70 to 90 mills per kilowatt hour) is compared with the levelized busbar energy cost for a new coal fired Rankine cycle plant. Sensitivities to the initial cost of coal and the delta fuel escalation are shown.

  18. Fundamental Astronomy

    CERN Document Server

    Karttunen, Hannu; Oja, Heikki; Poutanen, Markku; Donner, Karl Johan


    Fundamental Astronomy gives a well-balanced and comprehensive introduction to the topics of classical and modern astronomy. While emphasizing both the astronomical concepts and the underlying physical principles, the text provides a sound basis for more profound studies in the astronomical sciences. The fifth edition of this successful undergraduate textbook has been extensively modernized and extended in the parts dealing with the Milky Way, extragalactic astronomy and cosmology as well as with extrasolar planets and the solar system (as a consequence of recent results from satellite missions and the new definition by the International Astronomical Union of planets, dwarf planets and small solar-system bodies). Furthermore a new chapter on astrobiology has been added. Long considered a standard text for physical science majors, Fundamental Astronomy is also an excellent reference and entrée for dedicated amateur astronomers.

  19. SKA antenna systems; outlook for non-astronomy applications

    NARCIS (Netherlands)

    van Ardenne, A.; Bentum, Marinus Jan; Boonstra, A.J.


    The globally endorsed Square Kilometre Array project primarily aims to advance high sensitivity radio astronomy using a distributed collection of radio telescope stations spiraling outward from the core along three to five arms out to 3000km. This planned highly sensitive instrument covering a

  20. News Conference: Bloodhound races into history Competition: School launches weather balloon Course: Update weekends inspire teachers Conference: Finland hosts GIREP conference Astronomy: AstroSchools sets up schools network to share astronomy knowledge Teaching: Delegates praise science events in Wales Resources: ELI goes from strength to strength International: South Sudan teachers receive training Workshop: Delegates experience universality (United States)


    Conference: Bloodhound races into history Competition: School launches weather balloon Course: Update weekends inspire teachers Conference: Finland hosts GIREP conference Astronomy: AstroSchools sets up schools network to share astronomy knowledge Teaching: Delegates praise science events in Wales Resources: ELI goes from strength to strength International: South Sudan teachers receive training Workshop: Delegates experience universality

  1. Tools of radio astronomy

    CERN Document Server

    Wilson, Thomas L; Hüttemeister, Susanne


    This 6th edition of “Tools of Radio Astronomy”, the most used introductory text in radio astronomy, has been revised to reflect the current state of this important branch of astronomy. This includes the use of satellites, low radio frequencies, the millimeter/sub-mm universe, the Cosmic Microwave Background and the increased importance of mm/sub-mm dust emission. Several derivations and presentations of technical aspects of radio astronomy and receivers, such as receiver noise, the Hertz dipole and  beam forming have been updated, expanded, re-worked or complemented by alternative derivations. These reflect advances in technology. The wider bandwidths of the Jansky-VLA and long wave arrays such as LOFAR and mm/sub-mm arrays such as ALMA required an expansion of the discussion of interferometers and aperture synthesis. Developments in data reduction algorithms have been included. As a result of the large amount of data collected in the past 20 years, the discussion of solar system radio astronomy, dust em...

  2. Receiving Assistance and Local Food System Participation

    Directory of Open Access Journals (Sweden)

    Rebecca L. Som Castellano


    Full Text Available A body of literature has noted that local food systems (LFSs may not involve active participation by individuals with lower incomes. This is, in part, a function of racial and class hegemony, as well as physical and financial accessibility of LFSs. LFS institutions, such as farmers’ markets, have been working to facilitate receipt of food assistance programs, such as the Supplemental Nutrition Assistance Program (SNAP. Charitable assistance programs, such as food banks, have also been actively working to engage in LFSs, for example, by making local foods available. However, little research has explored the role that receiving public or charitable assistance can play in influencing LFS participation. In this article, I utilize quantitative and qualitative data collected from across the state of Ohio to examine the relationship between receiving assistance and LFS participation for women, who remain predominately responsible for food provisioning in the U.S., including among those who participate in LFSs. Quantitative results suggest that receiving assistance can increase participation in LFSs. Qualitative data provides more nuanced information about the importance of food assistance for women who want to participate in LFSs, and suggest that it is essential that food cooperatives and farmers’ markets are equipped to receive food assistance programs, such as SNAP, in order for women with lower incomes to participate in LFSs.

  3. National Parks for Astronomy and Solar System Outreach (United States)

    Nordgren, T. E.


    With the rise of urban lighting, national, state, and regional parks have become some of the last remaining dark-sky sites the typical family can easily visit. As a consequence, visitors to national parks in the United States consider a star-filled sky an integral part of their "park experience." U.S. national parks have therefore become an increasingly important tool for informal science education and outreach in the areas of astronomy and planetary science, potentially reaching tens of millions of people annually. Fostering stronger astronomer/park collaborations benefits educational and public outreach goals.

  4. Balloon infrared astronomy platform (BIRAP). [development and characteristics of a balloon-borne attitude control system (United States)

    Greeb, M. E.; True, G. A.


    The development of a balloon-borne attitude control system for infrared astronomy studies is discussed. The Balloon Infrared Astronomy Platform (BIRAP) is the result of the development effort. The BIRAP uses electronic gimballing for the offset pointing which eliminates a set of mechanical gimbals. Guide stars with visual magnitudes as low as plus 6 are used for fine tracking assuring that all areas of the sky can be covered. The BIRAP control concept uses a closed loop system in the airborne equipment with automatic update through a command link that can be operated either manually or automatically by a ground based computer.

  5. Astronomy essentials

    CERN Document Server

    Brass, Charles O


    REA's Essentials provide quick and easy access to critical information in a variety of different fields, ranging from the most basic to the most advanced. As its name implies, these concise, comprehensive study guides summarize the essentials of the field covered. Essentials are helpful when preparing for exams, doing homework and will remain a lasting reference source for students, teachers, and professionals. Astronomy includes the historical perspective of astronomy, sky basics and the celestial coordinate systems, a model and the origin of the solar system, the sun, the planets, Kepler'

  6. Transmitter-receiver system for time average fourier telescopy (United States)

    Pava, Diego Fernando

    Time Average Fourier Telescopy (TAFT) has been proposed as a means for obtaining high-resolution, diffraction-limited images over large distances through ground-level horizontal-path atmospheric turbulence. Image data is collected in the spatial-frequency, or Fourier, domain by means of Fourier Telescopy; an inverse twodimensional Fourier transform yields the actual image. TAFT requires active illumination of the distant object by moving interference fringe patterns. Light reflected from the object is collected by a "light-buckt" detector, and the resulting electrical signal is digitized and subjected to a series of signal processing operations, including an all-critical averaging of the amplitude and phase of a number of narrow-band signals. This dissertation reports on the formulation and analysis of a transmitter-receiver system appropriate for the illumination, signal detection, and signal processing required for successful application of the TAFT concept. The analysis assumes a Kolmogorov model for the atmospheric turbulence, that the object is rough on the scale of the optical wavelength of the illumination pattern, and that the object is not changing with time during the image-formation interval. An important original contribution of this work is the development of design principles for spatio-temporal non-redundant arrays of active sources for object illumination. Spatial non-redundancy has received considerable attention in connection with the arrays of antennas used in radio astronomy. The work reported here explores different alternatives and suggests the use of two-dimensional cyclic difference sets, which favor low frequencies in the spatial frequency domain. The temporal nonredundancy condition requires that all active sources oscillate at a different optical frequency and that the frequency difference between any two sources be unique. A novel algorithm for generating the array, based on optimized perfect cyclic difference sets, is described

  7. The Situation with Unique Classification Systems: UDC52 and Astronomy Thesaurus (United States)

    Dorokhova, T. N.; Dorokhov, N. I.


    The existing situation with two classification systems which could be very useful for the Virtual Observatory Mission is presented for discussion. UDC52 is the class for astronomy of the Universal Decimal Classification. Revision of UDC52 was undertaken by G. Wilkins in the 1990s for the British Standards Institute (BSI) and with the approval of IAU Commission 5; however, this project is not in progress at present. In Russia, Ukraine and many other countries the UDC is an obligatory essential element of information in natural and engineering sciences due to the high activity of VINITI (All-Russian Institute of Scientific and Technical Information). At present the VINITI is publishing the fourth complete edition of UDC schedules in 10 volumes. Apparently in the near future, information about the state of the class UDC52, Astronomy, will be presented on the internet. The Astronomy Thesaurus Project with the Multi-Lingual Supplement was realized by R. M. and R. R. Shobbrook in cooperation with librarians of different countries on the instructions of the IAU Commission 5. This list of terms with a definite hierarchy and relationships has demonstrated its usability for the building and development of the NASA ADS retrieval service. We have finished the translation of the Astronomy Thesaurus into Russian, and are preparing the Ukrainian version as an extension of the Multi-Lingual Supplement in the development of the Russian VO. We consider that establishing a special active Committee under Commission 5 for the updating process of the Astronomy Thesaurus and UDC52 and introducing into operation the up-to-date versions would be opportune and effective steps for IVO progress.

  8. Waste receiving and processing plant control system; system design description

    Energy Technology Data Exchange (ETDEWEB)

    LANE, M.P.


    The Plant Control System (PCS) is a heterogeneous computer system composed of numerous sub-systems. The PCS represents every major computer system that is used to support operation of the Waste Receiving and Processing (WRAP) facility. This document, the System Design Description (PCS SDD), includes several chapters and appendices. Each chapter is devoted to a separate PCS sub-system. Typically, each chapter includes an overview description of the system, a list of associated documents related to operation of that system, and a detailed description of relevant system features. Each appendice provides configuration information for selected PCS sub-systems. The appendices are designed as separate sections to assist in maintaining this document due to frequent changes in system configurations. This document is intended to serve as the primary reference for configuration of PCS computer systems. The use of this document is further described in the WRAP System Configuration Management Plan, WMH-350, Section 4.1.

  9. Workshop on Satellite Power Systems (SPS) effects on optical and radio astronomy

    Energy Technology Data Exchange (ETDEWEB)

    Stokes, G.M.; Ekstrom, P.A. (eds.)


    The impacts of the SPS on astronomy were concluded to be: increased sky brightness, reducing the effective aperture of terrestrial telescopes; microwave leakage radiation causing erroneous radioastronomical signals; direct overload of radioastronomical receivers at centimeter wavelengths; and unintentional radio emissions associated with massive amounts of microwave power or with the presence of large, warm structures in orbit causing the satellites to appear as individual stationary radio sources; finally, the fixed location of the geostationary satellite orbits would result in fixed regions of the sky being unusable for observations. (GHT)

  10. Digital coherent receiver technique for onboard receiver of future optical data relay system (United States)

    Araki, Tomohiro


    A digital coherent receiver technique for an onboard receiver for use in a future space optical communication system is investigated. Digital coherent technologies comprising coherent detection and digital signal processing are confirmed to possibly increase the signal speed, improve the receiver sensitivity, and extend tolerance for the Doppler frequency shift. As a facet of expandability, the concept of a multichannel-rate receiver using a digital coherent technique is introduced. Experimental results using 2.5 Gbps DBPSK signal light demodulation are presented together with future issues involved in implementation. This study confirms that the digital coherent receiver has higher expandability than other detection techniques.

  11. Chaco astronomies (United States)

    Martín López, Alejandro


    This presentation discusses the result of 18 years of ethnographic and ethnohistorical studies on Chaco astronomies. The main features of the systems of astronomical knowledge of the Chaco Aboriginal groups will be discussed. In particular we will discuss the relevance of the Milky Way, the role of the visibility of the Pleiades, the ways in which the celestial space is represented, the constitution of astronomical orientations in geographic space, etc. We also address a key feature of their vision of the cosmos: the universe is seen by these groups as a socio-cosmos, where humans and non-humans are related. These are therefore actually socio-cosmologies. We will link this to the theories of Chaco Aboriginal groups about power and political relations.We will discuss how the study of Aboriginal astronomies must be performed along with the studies about astronomies of Creole people and European migrants, as well as anthropological studies about the science teaching in the formal education system and by the mass media. In this form we will discuss the relevance of a very complex system of interethnic relations for the conformation of these astronomical representations and practices.We will also discuss the general methodological implications of this case for the ethnoastronomy studies. In particular we will talk about the advantages of a study of regional scope and about the key importance of put in contact the ethnoastronomy with contemporary issues in social sciences.We also analyze the importance of ethnoastronomy studies in relation to studies of sociology of science, especially astronomy. We also study the potential impact on improving formal and informal science curricula and in shaping effective policies to protect the tangible and intangible astronomical heritage in a context of respect for the rights of Aboriginal groups.

  12. WISE technology: A scientific information system for astronomy and beyond

    NARCIS (Netherlands)

    Belikov, A.; Boxhoorn, D.; Begeman, K.; Valentijn, E.; Vriend, W.-j.; Williams, O. R.


    The data processing of a number of current astronomical projects require an intelligent data handling system which can satisfy the requirements both from users processing the data and users exploring the result. We present the WISE Concept of Scientific Information Systems which has been used in a

  13. The Solar System Ballet: A Kinesthetic Spatial Astronomy Activity (United States)

    Heyer, Inge; Slater, T. F.; Slater, S. J.; Astronomy, Center; Education ResearchCAPER, Physics


    The Solar System Ballet was developed in order for students of all ages to learn about the planets, their motions, their distances, and their individual characteristics. To teach people about the structure of our Solar System can be revealing and rewarding, for students and teachers. Little ones (and some bigger ones, too) often cannot yet grasp theoretical and spatial ideas purely with their minds. Showing a video is better, but being able to learn with their bodies, essentially being what they learn about, will help them understand and remember difficult concepts much more easily. There are three segments to this activity, which can be done together or separately, depending on time limits and age of the students. Part one involves a short introductory discussion about what students know about the planets. Then students will act out the orbital motions of the planets (and also moons for the older ones) while holding a physical model. During the second phase we look at the structure of the Solar System as well as the relative distances of the planets from the Sun, first by sketching it on paper, then by recreating a scaled version in the class room. Again the students act out the parts of the Solar System bodies with their models. The third segment concentrates on recreating historical measurements of Earth-Moon-Sun system. The Solar System Ballet activity is suitable for grades K-12+ as well as general public informal learning activities.

  14. Fundamental astronomy

    CERN Document Server

    Kröger, Pekka; Oja, Heikki; Poutanen, Markku; Donner, Karl


    Now in its sixth edition this successful undergraduate textbook gives a well-balanced and comprehensive introduction to the topics of classical and modern astronomy. While emphasizing both the astronomical concepts and the underlying physical principles, the text provides a sound basis for more profound studies in the astronomical sciences. The chapters on galactic and extragalactic astronomy as well as cosmology were extensively modernized in the previous edition. In this new edition they have been further revised to include more recent results. The long chapter on the solar system has been split into two parts: the first one deals with the general properties, and the other one describes individual objects. A new chapter on exoplanets has been added to the end of the book next to the chapter on astrobiology. In response to the fact that astronomy has evolved enormously over the last few years, only a few chapters of this book have been left unmodified. Long considered a standard text for physical science maj...

  15. Armenian Cultural Astronomy (United States)

    Farmanyan, S. V.; Mickaelian, A. M.


    Cultural Astronomy is the reflection of sky events in various fields of nations' culture. In foreign literature this field is also called "Astronomy in Culture" or "Astronomy and Culture". Cultural astronomy is the set of interdisciplinary fields studying the astronomical systems of current or ancient societies and cultures. It is manifested in Religion, Mythology, Folklore, Poetry, Art, Linguistics and other fields. In recent years, considerable attention has been paid to this sphere, particularly international organizations were established, conferences are held and journals are published. Armenia is also rich in cultural astronomy. The present paper focuses on Armenian archaeoastronomy and cultural astronomy, including many creations related to astronomical knowledge; calendars, rock art, mythology, etc. On the other hand, this subject is rather poorly developed in Armenia; there are only individual studies on various related issues (especially many studies related to Anania Shirakatsi) but not coordinated actions to manage this important field of investigation.

  16. CANFAR+Skytree: A Cloud Computing and Data Mining System for Astronomy (United States)

    Ball, N. M.


    To-date, computing systems have allowed either sophisticated analysis of small datasets, as exemplified by most astronomy software, or simple analysis of large datasets, such as database queries. At the Canadian Astronomy Data Centre, we have combined our cloud computing system, the Canadian Advanced Network for Astronomical Research (CANFAR), with the world's most advanced machine learning software, Skytree, to create the world's first cloud computing system for data mining in astronomy. CANFAR provides a generic environment for the storage and processing of large datasets, removing the requirement for an individual or project to set up and maintain a computing system when implementing an extensive undertaking such as a survey pipeline. 500 processor cores and several hundred terabytes of persistent storage are currently available to users, and both the storage and processing infrastructure are expandable. The storage is implemented via the International Virtual Observatory Alliance's VOSpace protocol, and is available as a mounted filesystem accessible both interactively, and to all processing jobs. The user interacts with CANFAR by utilizing virtual machines, which appear to them as equivalent to a desktop. Each machine is replicated as desired to perform large-scale parallel processing. Such an arrangement enables the user to immediately install and run the same astronomy code that they already utilize, in the same way as on a desktop. In addition, unlike many cloud systems, batch job scheduling is handled for the user on multiple virtual machines by the Condor job queueing system. Skytree is installed and run just as any other software on the system, and thus acts as a library of command line data mining functions that can be integrated into one's wider analysis. Thus we have created a generic environment for large-scale analysis by data mining, in the same way that CANFAR itself has done for storage and processing. Because Skytree scales to large data in

  17. Tether enabled spacecraft systems for ultra long wavelength radio astronomy (United States)

    Gemmer, Thomas; Yoder, Christopher D.; Reedy, Jacob; Mazzoleni, Andre P.


    This paper describes a proposed CubeSat mission to perform unique experiments involving interferometry and tether dynamics. A 3U CubeSat is to be placed in orbit where it will separate into three 1U CubeSats connected by a total of 100 m of tether. The separation between the three units will allow for the demonstration of high resolution radio interferometry. The increased resolution will provide access to the Ultra-Long Wavelength (ULW) scale of the electromagnetic spectrum, which is largely unexplored. During and after completion of the primary experiment, the CubeSat will be able to gather data on tethered dynamics of a space vehicle. Maneuvers to be performed and studied include direct testing of tether deployment and tethered formation flying. Tether deployment is a vital area where more data is needed as this is the phase where many tethered missions have experienced complications and failures. There are a large number of complex dynamical responses predicted by the theory associated with the deployment of an orbiting tethered system. Therefore, it is imperative to conduct an experiment that provides data on what dynamic responses actually occur.

  18. Joint Transmitter-Receiver Optimization in the Downlink CDMA Systems

    Directory of Open Access Journals (Sweden)

    Mohammad Saquib


    Full Text Available To maximize the downlink code-division multiple access (CDMA system capacity, we propose to minimize the total transmitted power of the system subject to users′ signal-to-interference ratio (SIR requirements via designing optimum transmitter sequences and utilizing linear optimum receivers (minimum mean square error (MMSE receiver. In our work on joint transmitter-receiver design for the downlink CDMA systems with multiple antennas and multipath channels, we develop several optimization algorithms by considering various system constraints and prove their convergence. We empirically observed that under the optimization algorithm with no constraint on the system, the optimum receiver structure matches the received transmitter sequences. A simulation study is performed to see how the different practical system constraints penalize the system with respect to the optimum algorithm with no constraint on the system.

  19. Astronomy Patch Day: An Interactive Astronomy Experience for Girl Scouts (United States)

    Knierman, K. A.; McCarthy, D. W.; Schutz, K.


    To help encourage a new generation of women in science, we have created Astronomy Patch Day for the Sahuaro Girl Scout Council in Tucson, Arizona. This all-day event is an interactive experience for Girl Scouts ages 5-18 to learn about astronomical concepts and women in astronomy. Our first Astronomy Patch Day, held on March 19, 2005, in conjunction with the Sahuaro Council's annual Science, Math, and Related Technologies (SMART) program, was very successful, reaching about 150-200 girls and their leaders. Individual troops rotated every half hour among our six activity booths: Earth-Moon, Solar System, Stars, Galaxies, Universe, and Ask an Astronomer, which were staffed by trained Girl Scout Leaders as well as faculty, post-doctoral researchers, and graduate students from Steward Observatory. To earn a patch, younger girls (ages 5-12) had to complete activities at three booths and older girls had to complete all six activities. Positive feedback for this event was received from both the girls and leaders. We plan to hold Astronomy Patch Day annually, possibly with different and/or additional activities in future years. K. Knierman is supported by an Arizona/NASA Space Grant Fellowship. This outreach program is supported by NIRCam/JWST E/PO.

  20. Handbook of Practical Astronomy

    CERN Document Server

    Roth, Günter D


    With amateurs, students, and teachers of astronomy in high schools and colleges particularly in mind, the Handbook of Practical Astronomy is an essential source to demonstrate trends and variety of astronomical observations. The book presents the substance of celestial bodies for the amateur observer: the planets, the stars, and the galaxies. The sun is the local link to the other stars, the nexus of cosmic evolution. The solar system is made up by the sun and all the celestial bodies orbit it. This system is of special interest for the observing amateur. The Handbook of Practial Astronomy spans astronomy, education and computing. Like many other fields of science, astronomy has become digitized and data rich in recent years. Besides the references at the end of each chapter, there are the notes in the margins with astronomical news and observing highlights on the web.

  1. BVRI Standardization of the CCD Photometric System of Sobaeksan Optical Astronomy Observatory

    Directory of Open Access Journals (Sweden)

    Jang Hae Jeong


    Full Text Available A total of 792 CCD images of V523 Cas were obtained on four nights of Jan. 2003 with the BVRI CCD photometric system attached to a 61cm reflector of Sobaeksan Optical Astronomy Observatory (SOAO. The 17 standard stars in the images were used to establish transformation relations between our BVRI system and the standard Johnson-Cousins BVRI system. We derived the tentative equations of transformation between two photometric systems as follows; V = v-0.0689(B-V+0.0063 B-V = 1.3197(b-v-0.1733 V-R = 0.9210(v-r-0.1309 R-I = 0.8892(r-i-0.1055. Using these equations standard V magnitudes and their color indexes (B-V, V-R, R-I for 57 stars in the field of the image were determined.

  2. e2v CMOS and CCD sensors and systems for astronomy (United States)

    Jorden, P. R.; Jerram, P. A.; Fryer, M.; Stefanov, K. D.


    e2v designs and manufactures a wide range of sensors for space and astronomy applications. This includes high performance CCDs for X-ray, visible and near-IR wavelengths. In this paper we illustrate the maturity of CMOS capability for these applications; examples are presented together with performance data. The majority of e2v sensors for these applications are back-thinned for highest spectral response and designed for very low read-out noise; the combination delivers high signal to noise ratio in association with a variety of formats and package designs. The growing e2v capability in delivery of sub-systems and cryogenic cameras is illustrated—including the 1.2 Giga-pixel J-PAS camera system.

  3. Handbook of pulsar astronomy

    CERN Document Server

    Lorimer, Duncan


    Radio pulsars are rapidly rotating highly magnetized neutron stars. Studies of these fascinating objects have provided applications in solid-state physics, general relativity, galactic astronomy, astrometry, planetary physics and even cosmology. Most of these applications and much of what we know about neutron stars are derived from single-dish radio observations using state-of-the-art receivers and data acquisition systems. This comprehensive 2004 book is a unique resource that brings together the key observational techniques, background information and a review of results, including the discovery of a double pulsar system. Useful software tools are provided which can be used to analyse example data, made available on a related website. This work will be of great value not only to graduate students but also to researchers wishing to carry out and interpret a wide variety of radio pulsar observations.

  4. Astronomy research in China (United States)

    Wang, Jingxiu

    Decades of efforts made by Chinese astronomers have established some basic facilities for astronomy observations, such as the 2.16-m optical telescope, the solar magnetic-field telescope, the 13.7-m millimeter-wave radio telescope etc. One mega-science project, the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST), intended for astronomical and astrophysical studies requiring wide fields and large samples, has been initiated and funded. To concentrate the efforts on mega-science projects, to operate and open the national astronomical facilities in a more effective way, and to foster the best astronomers and research groups, the National Astronomical Observatories (NAOs) has been coordinated and organizated. Four research centers, jointly sponsored by observatories of the Chinese Academy of Sciences and universities, have been established. Nine principal research fields have received enhanced support at NAOs. They are: large-scale structure of universe, formation and evolution of galaxies, high-energy and cataclysmic processes in astrophysics, star formation and evolution, solar magnetic activity and heliogeospace environment, astrogeodynamics, dynamics of celestial bodies in the solar system and artificial bodies, space-astronomy technology, and new astronomical techniques and methods.

  5. The road to OLFAR - a roadmap to interferometric long-wavelength radio astronomy using miniaturized distributed space systems

    NARCIS (Netherlands)

    Engelen, Steven; Quillien, Kevin A.; Verhoeven, Chris; Noroozi, Arash; Sundaramoorthy, Prem; van der Veen, Alle-Jan; Rajan, Raj; Rajan, Raj Thilak; Boonstra, Albert Jan; Bentum, Marinus Jan; Meijerink, Arjan; Budianu, A.


    The Orbiting Low Frequency Antennas for Radio Astronomy (OLFAR) project aims to develop a space-based low frequency radio telescope that will explore the universe's so-called dark ages, map the interstellar medium, and discover planetary and solar bursts in other solar systems. The telescope,

  6. Asymmetric Hardware Distortions in Receive Diversity Systems: Outage Performance Analysis

    KAUST Repository

    Javed, Sidrah


    This paper studies the impact of asymmetric hardware distortion (HWD) on the performance of receive diversity systems using linear and switched combining receivers. The asymmetric attribute of the proposed model motivates the employment of improper Gaussian signaling (IGS) scheme rather than the traditional proper Gaussian signaling (PGS) scheme. The achievable rate performance is analyzed for the ideal and non-ideal hardware scenarios using PGS and IGS transmission schemes for different combining receivers. In addition, the IGS statistical characteristics are optimized to maximize the achievable rate performance. Moreover, the outage probability performance of the receive diversity systems is analyzed yielding closed form expressions for both PGS and IGS based transmission schemes. HWD systems that employ IGS is proven to efficiently combat the self interference caused by the HWD. Furthermore, the obtained analytic expressions are validated through Monte-Carlo simulations. Eventually, non-ideal hardware transceivers degradation and IGS scheme acquired compensation are quantified through suitable numerical results.

  7. Mathematical Astronomy in India (United States)

    Plofker, Kim

    Astronomy in South Asia's Sanskrit tradition, apparently originating in simple calendric computations regulating the timing of ancient ritual practices, expanded over the course of two or three millennia to include detailed spherical models, an endless variety of astrological systems, and academic mathematics in general. Assimilating various technical models, methods, and genres from the astronomy of neighboring cultures, Indian astronomers created new forms that were in turn borrowed by their foreign counterparts. Always recognizably related to the main themes of Eurasian geocentric mathematical astronomy, Indian astral science nonetheless maintained its culturally distinct character until Keplerian heliocentrism and Newtonian mechanics replaced it in colonial South Asia's academic mainstream.

  8. Solar Central Receiver Hybrid Power Systems sodium-cooled receiver concept. Final report. Volume III. Appendices

    Energy Technology Data Exchange (ETDEWEB)



    The overall, long term objective of the Solar Central Receiver Hybrid Power System is to identify, characterize, and ultimately demonstrate the viability and cost effectiveness of solar/fossil, steam Rankine cycle, hybrid power systems that: (1) consist of a combined solar central receiver energy source and a nonsolar energy source at a single, common site, (2) may operate in the base, intermediate, and peaking capacity modes, (3) produce the rated output independent of variations in solar insolation, (4) provide a significant savings (50% or more) in fuel consumpton, and (5) produce power at the minimum possible cost in mills/kWh. It is essential that these hybrid concepts be technically feasible and economically competitive with other systems in the near to mid-term time period (1985-1990) on a commercial scale. The program objective for Phase I is to identify and conceptually characterize solar/fossil steam Rankine cycle, commercial-scale, power plant systems that are economically viable and technically feasible. This volume contains appendices to the conceptual design and systems analysis studies gien in Volume II, Books 1 and 2. (WHK)

  9. An automated test system for terahertz receiver characterization (United States)

    Kuenzi, Linda C.; Groppi, Christopher E.; Wheeler, Caleb H.; Mani, Hamdi


    An automated test system was developed to characterize detectors for the Kilopixel Array Pathfinder Project (KAPPa), a 16-pixel 2D integrated heterodyne focal plane array. Although primarily designed for KAPPa, the system can be used with other instruments to automate tests that might be tedious and time-consuming by hand. Mechanical components include an adjustable structure of aluminum t-slot framing that supports a rotating chopper. Driven by a stepper motor, the wheel alternates between blackbodies at room temperature and 77 K. The cold load consists of absorbing material submerged in liquid nitrogen in an open Styrofoam cooler. Python scripts control the mechanical system, interface with receiver components, and process data. Test system operation was verified by sweeping the local oscillator frequency with a Virginia Diodes room temperature receiver. The system was then integrated with the KAPPa receiver to allow complete and automated testing of all array pixels with minimal user intervention.

  10. A Fast Adaptive Receive Antenna Selection Method in MIMO System

    Directory of Open Access Journals (Sweden)

    Chaowei Wang


    Full Text Available Antenna selection has been regarded as an effective method to acquire the diversity benefits of multiple antennas while potentially reduce hardware costs. This paper focuses on receive antenna selection. According to the proportion between the numbers of total receive antennas and selected antennas and the influence of each antenna on system capacity, we propose a fast adaptive antenna selection algorithm for wireless multiple-input multiple-output (MIMO systems. Mathematical analysis and numerical results show that our algorithm significantly reduces the computational complexity and memory requirement and achieves considerable system capacity gain compared with the optimal selection technique in the same time.

  11. SDR implementation of the receiver of adaptive communication system (United States)

    Skarzynski, Jacek; Darmetko, Marcin; Kozlowski, Sebastian; Kurek, Krzysztof


    The paper presents software implementation of a receiver forming a part of an adaptive communication system. The system is intended for communication with a satellite placed in a low Earth orbit (LEO). The ability of adaptation is believed to increase the total amount of data transmitted from the satellite to the ground station. Depending on the signal-to-noise ratio (SNR) of the received signal, adaptive transmission is realized using different transmission modes, i.e., different modulation schemes (BPSK, QPSK, 8-PSK, and 16-APSK) and different convolutional code rates (1/2, 2/3, 3/4, 5/6, and 7/8). The receiver consists of a software-defined radio (SDR) module (National Instruments USRP-2920) and a multithread reception software running on Windows operating system. In order to increase the speed of signal processing, the software takes advantage of single instruction multiple data instructions supported by x86 processor architecture.

  12. Performance Evaluation of Irbene RT-16 Radio Telescope Receiving System

    Directory of Open Access Journals (Sweden)

    Bleiders M.


    Full Text Available In the present paper, recent measurement results of refurbished Irbene RT-16 radio telescope receiving system performance are presented. The aim of the research is to evaluate characteristics of RT-16, which will allow carrying out necessary amplitude calibration in both single dish and VLBI observations, to improve the performance of existing system as well as to monitor, control and compare performance if possible changes in the receiving system will occur in future. The evaluated receiving system is 16 m Cassegrain antenna equipped with a cryogenic receiver with frequency range from 4.5 to 8.8 GHz, which is divided into four sub-bands. Multiple calibration sessions have been carried out by observing stable astronomical sources with known flux density by using in-house made total power registration backend. First, pointing offset calibration has been carried out and pointing model coefficients calculated and applied. Then, amplitude calibration, namely antenna sensitivity, calibration diode equivalent flux density and gain curve measurements have been carried out by observing calibration sources at different antenna elevations at each of the receiver sub-bands. Beam patterns have also been evaluated at different frequency bands. As a whole, acquired data will serve as a reference point for comparison in future performance evaluation of RT-16.

  13. The Effect of Two Receivers on Broadcast Molecular Communication Systems. (United States)

    Lu, Yi; Higgins, Matthew D; Noel, Adam; Leeson, Mark S; Chen, Yunfei


    Molecular communication is a paradigm that utilizes molecules to exchange information between nano-machines. When considering such systems where multiple receivers are present, prior work has assumed for simplicity that they do not interfere with each other. This paper aims to address this issue and shows to what extent an interfering receiver, [Formula: see text], will have an impact on the target receiver, [Formula: see text], with respect to Bit Error Rate (BER) and capacity. Furthermore, approximations of the Binomial distribution are applied to reduce the complexity of calculations. Results show the sensitivity in communication performance due to the relative location of the interfering receiver. Critically, placing [Formula: see text] between the transmitter [Formula: see text] and [Formula: see text] causes a significant increase in BER or decrease in capacity.

  14. Greek astronomy

    CERN Document Server

    Heath, Sir Thomas L


    Astronomy as a science began with the Ionian philosophers, with whom Greek philosophy and mathematics also began. While the Egyptians and Babylonians had accomplished much of astronomical worth, it remained for the unrivalled speculative genius of the Greeks, in particular, their mathematical genius, to lay the foundations of the true science of astronomy. In this classic study, a noted scholar discusses in lucid detail the specific advances made by the Greeks, many of whose ideas anticipated the discoveries of modern astronomy.Pythagoras, born at Samos about 572 B.C., was probably the first

  15. Fundamental Astronomy and Solar System Dynamics : Invited Papers Honoring Prof. Walter Fricke on the occasion of his 70th birthday

    CERN Document Server

    Lieske, J; Seidelmann, P


    "Fundamental Astronomy and Solar System Dynamics", a program of invited papers honoring Professor Walter Fricke, who for thirty years has been Director of the Astronomisches Rechen lnstitut in Heidelberg, was held at the Thompson Conference Center of the University of Texas at Austin on Wednesday 27 March 1985 on the occasion of his seventieth birthday and retirement as Director of ARl. Professor Fricke's contributions to astronomy encompass the areas of galactic dynamics, radial velocities, stellar statistics. the fundamental reference system and the constant of precession. Participants were welcomed to the Uni versi ty of Texas by Professor J. Parker Lamb, Chairman of the Department of Aerospace Engineering and Engineering Mechanics. The presentations ranged from discussions of astrometric problems concerned with the reference system, the constant of precession, major and minor planet observations, planetary ephemerides and lunar and satellite laser ranging, to a study of disc galaxies in massive halos. The...

  16. A Receiver System for the TileCal Muon Signals

    CERN Document Server

    Ciodaro, T


    The muon signals of the hadronic calorimeter of ATLAS (TileCal) have successfully been used to trigger on cosmic rays. These muon signals provided by the trigger tower adder system is currently not used by ATLAS level-one muon trigger, as it has been foreseen for a near-future upgrade. Studies showed that the signal-to-noise ratio is increased if muon signals from the same cell of the last TileCal segmentation layer are summed up together. This work presents a receiver system design for the TileCal muon signals, which is based on the analog sum of both readout signals of the last TileCal detection layer. The receiver system interfaces to ATLAS level-one trigger system aiming at improving overall muon detection.

  17. Single Cell Analysis of a Bacterial Sender-Receiver System. (United States)

    Ramalho, Tiago; Meyer, Andrea; Mückl, Andrea; Kapsner, Korbinian; Gerland, Ulrich; Simmel, Friedrich C


    Monitoring gene expression dynamics on the single cell level provides important information on cellular heterogeneity and stochasticity, and potentially allows for more accurate quantitation of gene expression processes. We here study bacterial senders and receivers genetically engineered with components of the quorum sensing system derived from Aliivibrio fischeri on the single cell level using microfluidics-based bacterial chemostats and fluorescence video microscopy. We track large numbers of bacteria over extended periods of time, which allows us to determine bacterial lineages and filter out subpopulations within a heterogeneous population. We quantitatively determine the dynamic gene expression response of receiver bacteria to varying amounts of the quorum sensing inducer N-3-oxo-C6-homoserine lactone (AHL). From this we construct AHL response curves and characterize gene expression dynamics of whole bacterial populations by investigating the statistical distribution of gene expression activity over time. The bacteria are found to display heterogeneous induction behavior within the population. We therefore also characterize gene expression in a homogeneous bacterial subpopulation by focusing on single cell trajectories derived only from bacteria with similar induction behavior. The response at the single cell level is found to be more cooperative than that obtained for the heterogeneous total population. For the analysis of systems containing both AHL senders and receiver cells, we utilize the receiver cells as 'bacterial sensors' for AHL. Based on a simple gene expression model and the response curves obtained in receiver-only experiments, the effective AHL concentration established by the senders and their 'sending power' is determined.

  18. Controller-area-network bus control and monitor system for a radio astronomy interferometer. (United States)

    Woody, David P; Wiitala, Bradley; Scott, Stephen L; Lamb, James W; Lawrence, Ronald P; Giovanine, Curt; Fredsti, Sancar J; Beard, Andrew; Pryke, Clem; Loh, Michael; Greer, Christopher H; Cartwright, John K; Gutierrez-Kraybill, Colby; Bolatto, Alberto D; Muchovej, Stephen J C


    We describe the design and implementation of a controller-area-network bus (CANbus) monitor and control system for a millimeter wave interferometer. The Combined Array for Research in Millimeter-wave Astronomy (CARMA) is a 15-antenna connected-element interferometer for astronomical imaging, created by the merger of two university observatories. Its new control system relies on a central computer supervising a variety of subsystem computers, many of which control distributed intelligent nodes over CANbus. Subsystems are located in the control building and in individual antennas and communicate with the central computer via Ethernet. Each of the CAN modules has a very specific function, such as reading an antenna encoder or tuning an oscillator. Hardware for the modules was based on a core design including a commercial CANbus-enabled single-board computer and some standard circuitry for interfacing to peripherals. Hardware elements were added or changed as necessary for the specific module types. Similarly, a base set of embedded code was implemented for essential common functions such as CAN message handling and time keeping and extended to implement the required functionality for the different hardware. Using a standard CAN messaging protocol designed to fit the requirements of CARMA and a well-defined interface to the high-level software allowed separate development of high-level code and embedded code with minimal integration problems. Over 30 module types have been implemented and successfully deployed in CARMA, which is now delivering excellent new science data.

  19. Development of an Experimental Phased Array Feed System and Algorithms for Radio Astronomy (United States)

    Landon, Jonathan C.

    Phased array feeds (PAFs) are a promising new technology for astronomical radio telescopes. While PAFs have been used in other fields, the demanding sensitivity and calibration requirements in astronomy present unique new challenges. This dissertation presents some of the first astronomical PAF results demonstrating the lowest noise temperature and highest sensitivity at the time (66 Kelvin and 3.3 m^2/K, respectively), obtained using a narrowband (425 kHz bandwidth)prototype array of 19 linear co-polarized L-band dipoles mounted at the focus of the Green Bank 20 Meter Telescope at the National Radio Astronomy Observatory (NRAO) in Green Bank, West Virginia. Results include spectral line detection of hydroxyl (OH) sources W49N and W3OH, and some of the first radio camera images made using a PAF, including an image of the Cygnus X region. A novel array Y-factor technique for measuring the isotropic noise response of the array is shown along with experimental measurements for this PAF. Statistically optimal beamformers (Maximum SNR and MVDR) are used throughout the work. Radio-frequency interference (RFI) mitigation is demonstrated experimentally using spatial cancelation with the PAF. Improved RFI mitigation is achieved in the challenging cases of low interference-to-noise ratio (INR) and moving interference by combining subspace projection (SP) beamforming with a polynomial model to track a rank 1 subspace. Limiting factors in SP are investigated including sample estimation error, subspace smearing, noise bias, and spectral scooping; each of these factors is overcome with the polynomial model and prewhitening. Numerical optimization leads to the polynomial subspace projection (PSP) method, and least-squares fitting to the series of dominant eigenvectors over a series of short term integrations (STIs) leads to the eigenvector polynomial subspace projection (EPSP) method. Expressions for the gradient, Hessian, and Jacobian are given for use in numerical optimization

  20. System for transmitting and receiving multi-polarized signals

    DEFF Research Database (Denmark)


    The present disclosure relates to: an optical receiver, configured to receive at least three multiplexed, differently polarized, optically transmitted signals, each signal associated with a predefined state of polarization, said receiver comprising a multi- polarization analyzer for obtaining...... an analyzed signal for each of said polarized signals, wherein at least one of said analyzed signals comprises data in the full Stokes space; an optical transmitter, configured to transmit at least three multiplexed, differently polarized, optically transmitted signals, wherein at least one of said polarized...... signals comprises data in the full Stokes space; a system configured to communicate optically over a communication link, comprising: an optical transmitter, configured to generate and multiplex at least three independent data signals having different states of polarization into a multiplexed signal...

  1. The Sardinia Radio Telescope conversion, distribution, and receiver control system (United States)

    Monari, J.; Orfei, A.; Scalambra, A.; Mariotti, S.; Poloni, M.; Fiocchi, F.; Cattani, A.; Maccaferri, A.; Perini, F.; Boschi, M.

    The recent upgrade of the 32-m radio telescope located in Medicina (Bologna - Italy) has allowed us to gain a lot of know-how about ''frequency agility'' management. In this parabolic dish antenna the receiver change is now completely performed only using software controls and avoiding, in this way, human intervention. The acquired experience on this topic has been used to define the framework for the conversion/distribution system design for the SRT (Sardinia Radio Telescope), the new ''64-meter class'' Italian radio telescope. The suitably designed architectures for Local Oscillators (LOs), Intermediate Frequencies (IFs), Ground Unit (GU), Reference (REF) distribution systems and control system will be described in this paper.

  2. Automatic Identification System modular receiver for academic purposes (United States)

    Cabrera, F.; Molina, N.; Tichavska, M.; Araña, V.


    The Automatic Identification System (AIS) standard is encompassed within the Global Maritime Distress and Safety System (GMDSS), in force since 1999. The GMDSS is a set of procedures, equipment, and communication protocols designed with the aim of increasing the safety of sea crossings, facilitating navigation, and the rescue of vessels in danger. The use of this system not only is increasingly attractive to security issues but also potentially creates intelligence products throughout the added-value information that this network can transmit from ships on real time (identification, position, course, speed, dimensions, flag, among others). Within the marine electronics market, commercial receivers implement this standard and allow users to access vessel-broadcasted information if in the range of coverage. In addition to satellite services, users may request actionable information from private or public AIS terrestrial networks where real-time feed or historical data can be accessed from its nodes. This paper describes the configuration of an AIS receiver based on a modular design. This modular design facilitates the evaluation of specific modules and also a better understanding of the standard and the possibility of changing hardware modules to improve the performance of the prototype. Thus, the aim of this paper is to describe the system's specifications, its main hardware components, and to present educational didactics on the setup and use of a modular and terrestrial AIS receiver. The latter is for academic purposes and in undergraduate studies such as electrical engineering, telecommunications, and maritime studies.

  3. System for Isolation Testing of RF Transmitters and Receivers (United States)


    memory 30B. [0018] Programmable device 30 can be based on a software defined radio ( SDR ) configured to operate as described herein. By way of such software defined radio is the open source GNU radio platform utilizing the Universal Software Radio Peripheral. [0019] The advantages a system that can perform isolation testing of a radio frequency (RF) transmitter or an RF receiver. (2) Description of the Prior Art [0004

  4. Novel calibration system with sparse wires for CMB polarization receivers

    Energy Technology Data Exchange (ETDEWEB)

    Tajima, O.; /KEK, Tsukuba /Chicago U., KICP; Nguyen, H.; /Fermilab; Bischoff, C.; /Chicago U., KICP /Harvard-Smithsonian Ctr. Astrophys.; Brizius, A.; Buder, I.; Kusaka, A. /Chicago U., KICP


    B-modes in the cosmic microwave background (CMB) polarization is a smoking gun signature of the inflationary universe. To achieve better sensitivity to this faint signal, CMB polarization experiments aim to maximize the number of detector elements, resulting in a large focal plane receiver. Detector calibration of the polarization response becomes essential. It is extremely useful to be able to calibrate 'simultaneously' all detectors on the large focal plane. We developed a novel calibration system that rotates a large 'sparse' grid of metal wires, in front of and fully covering the field of view of the focal plane receiver. Polarized radiation is created via the reflection of ambient temperature from the wire surface. Since the detector has a finite beam size, the observed signal is smeared according to the beam property. The resulting smeared polarized radiation has a reasonable intensity (a few Kelvin or less) compared to the sky temperature ({approx}10 K observing condition). The system played a successful role for receiver calibration of QUIET, a CMB polarization experiment located in the Atacama desert in Chile. The successful performance revealed that this system is applicable to other experiments based on different technologies, e.g. TES bolometers.

  5. Conceptual design of advanced central receiver power system. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Tracey, T. R.


    The design of a 300 MWe tower focus power plant which uses molten salt heat transfer fluids and sensible heat storage is described in detail. The system consists of nine heliostat fields with 7711 heliostats in each. Four cavity receivers are located at the top of a 155-meter tower. Tasks include: (1) review and analysis of preliminary specification; (2) parametric analysis; (3) selection of preferred configuration; (4) commercial plant conceptual design; (5) assessment of commercial-sized advanced central power system; (6) development plan; (7) program plan; (8) reports and data; (9) program management; (10) safety analysis; and (11) material study and test program. (WHK)

  6. ALO4: Angle Localization and Orientation System with Four Receivers

    Directory of Open Access Journals (Sweden)

    Santiago Elvira


    Full Text Available This paper presents a 2D indoor localization and orientation system based on a TDOA (Time Difference of Arrival technique. It uses an array of receivers (four low-cost ultrasonic resonant devices in a square distribution to implement low-computational-effort DOA (Direction of Arrival algorithms, based on assumed plane-wave reception. The system only demands two transmitters at well-known positions on the ceiling of the room for obtaining the node position and orientation when it is deployed on the floor of the room. This system has been tested using a Xilinx Spartan-3A FPGA that implements a 52 MHz MicroBlaze. The experimental results include a total of 1,440 points, obtaining a mean localization error of 5.17 cm and a mean orientation error of 3.34°. For this system, the localization and orientation processes are executed in less than 50 us.

  7. Astronomy Allies (United States)

    Flewelling, Heather; Alatalo, Katherine A.


    Imagine you are a grad student, at your first conference, and a prominent senior scientist shows interest in your work, and he makes things get way too personal? What would you do? Would you report it? Or would you decide, after a few other instances of harassment, that maybe you shouldn't pursue astronomy? Harassment is under-reported, the policies can be difficult to understand or hard to find, and it can be very intimidating as a young scientist to report it to the proper individuals. The Astronomy Allies Program is designed to help you with these sorts of problems. We are a group of volunteers that will help by doing the following: provide safe walks home during the conference, someone to talk to confidentially, as an intervener, as a resource to report harassment. The Allies are a diverse group of scientists committed to acting as mentors, advocates, and liaisons. The Winter 2015 AAS meeting was the first meeting that had Astronomy Allies, and Astronomy Allies provided a website for information, as well as a twitter, email, and phone number for anyone who needs our help or would like more information. We posted about the Astronomy Allies on the Women In Astronomy blog, and this program resonates with many people: either they want to help, or they have experienced harassment in the past and don't want to see it in the future. Harassment may not happen to most conference participants, but it's wrong, it's against the AAS anti-harassment policy ( ), it can be very damaging, and if it happens to even one person, that is unacceptable. We intend to improve the culture at conferences to make it so that harassers feel they can't get away with their unprofessional behavior.

  8. Exploring the Universe Together: Cooperative Quizzes with and without a Classroom Performance System in Astronomy 101 (United States)

    Byrd, Gene G.; Coleman, Susanna; Werneth, Charles


    Our University of Alabama introductory astronomy course has large enrollments, with the usual problems of low attendance and students putting off studying until just before major exams--with predictable consequences. We tried one strategy--cooperatively answering quiz questions--during our May 2002 interim term. Classes were long: three hours a…

  9. Using Visual Assessments and Tutorials to Teach Solar System Concepts in Introductory Astronomy (United States)

    LoPresto, Michael C.


    Visual assessments and tutorials are instruments that rely on student construction and/or examination of pictures and/or diagrams rather than multiple choice and/or short answer questions. Being a very visual subject, astronomy lends itself to assessments and tutorials of this type. What follows is a report on the results of the use of visual…

  10. Rescuing Middle School Astronomy (United States)

    Mayo, L. A.; Janney, D.


    There is a crisis in education at the middle school level (Spellings, 2006). Recent studies point to large disparities in middle school performance in schools with high minority populations. The largest disparities exist in areas of math and science. Astronomy has a universal appeal for K-12 students but is rarely taught at the middle school level. When it is taught at all it is usually taught in isolation with few references in other classes such as other sciences (e.g. physics, biology, and chemistry), math, history, geography, music, art, or English. The problem is greatest in our most challenged school districts. With scores in reading and math below national averages in these schools and with most state achievement tests ignoring subjects like astronomy, there is little room in the school day to teach about the world outside our atmosphere. Add to this the exceedingly minimal training and education in astronomy that most middle school teachers have and it is a rare school that includes any astronomy teaching at all. In this presentation, we show how to develop and offer an astronomy education training program for middle school teachers encompassing a wide range of educational disciplines that are frequently taught at the middle school level. The prototype for this program was developed and launched in two of the most challenged and diverse school systems in the country; D.C. Public Schools, and Montgomery County (MD) Public Schools.

  11. Astronomy Activities. (United States)

    Greenstone, Sid

    This document consists of activities and references for teaching astronomy. The activities (which include objectives, list of materials needed, and procedures) focus on: observing the Big Dipper and locating the North Star; examining the Big Dipper's stars; making and using an astrolabe; examining retograde motion of Mars; measuring the Sun's…

  12. CIAO: A Modern Data Analysis System for X-Ray Astronomy (United States)

    Fruscione, Antonella


    It is now eighteen years after launch and Chandra continues to produce spectacular results!A portion of the success is to be attributed to the data analysis software CIAO (Chandra Interactive Analysis of Observations) that the Chandra X-Ray Center (CXC) continues to improve and release year after year.CIAO is downloaded more than 1200 times a year and it is used by a wide variety of users around the world: from novice to experienced X-ray astronomers, high school, undergraduate and graduate students, archival users (many new to X-ray or Chandra data), users with extensive resources and others from smaller countries and institutions.The scientific goals and kinds of datasets and analysis cover a wide range: observations spanning from days to years, different instrument configurations and different kinds of targets, from pointlike stars and quasars, to fuzzy galaxies and clusters, to moving solar objects. These different needs and goals require a variety of specialized software and careful and detailed documentation which is what the CIAO software provides. In general, we strive to build a software system which is easy for beginners, yet powerful for advanced users.The complexity of the Chandra data require a flexible data analysis system which provides an environment where the users can apply our tools, but can also explore and construct their own applications. The main purpose of this talk is to present CIAO as a modern data analysis system for X-ray data analysis.CIAO has grown tremendously over the years and we will highlight (a) the most recent advancements with a particular emphasis on the newly developed high-level scripts which simplify the analysis steps for the most common cases making CIAO more accessible to all users - including beginners and users who are not X-ray astronomy specialists, (b) the python-based Sherpa modelling and fitting application and the new stand-alone version openly developed and distributed on Github and (c) progress on methods to

  13. Astronomy and Poetry (overview) (United States)

    Samvelyan, David


    Through this work we have tried to show how astronomy penetrates into the poetry of different periods in time and in various poets' works all over the world. The following work has significant cognitive value, demonstrates and reveals the general nature of certain poets' astronomical ideas and provides a brief analysis in some cases. As a result, we have come to the conclusion that astronomy with all its components such as the sky, our solar system and phenomena such as these have always been a source of inspiration for those who create works of art, moreover some of them have even gained actual astronomical knowledge.

  14. Building a Successful Teachers' Workshop in Astronomy & Astrophysics (United States)

    Smecker-Hane, T. A.; Thornton, C. E.


    We discuss the Teachers' Workshop in Astronomy & Astrophysics, a 2-day long summer workshop we designed to aid K-12 grade teachers in incorporating astronomy and astrophysics into their curricula. These workshops are part of a faculty-led outreach program entitled Outreach in Astronomy & Astrophysics with the UCI Observatory, funded by an NSF FOCUS grant to the University of California, Irvine. Approximately 20 teachers from the Compton, Newport/Mesa and Santa Ana Unified School Districts attend each workshop. Our teachers realize that astronomy captures the imagination of their students, and thus lessons in astronomy can very effectively convey a number of challenging math and science concepts. Our workshop is designed to give teachers the content and instruction needed to achieve that goal. Because only a small fraction of teachers have taken a college astronomy course, an important component of the workshop is lectures on: (1) the motion of objects in the night sky, moon phases and the seasons, (2) the solar system, (3) the physics of light, and (4) interesting applications such as searching for planets around other stars and charting the expansion history of the Universe. The second important component of the workshop is the kit of material each teacher receives, which includes a introductory astronomy textbook, planetarium software, and the ASP's "Universe at Your Fingertips" and "More Universe at Your Fingertips", etc.. The latter two books give teachers many examples of creative hands-on activities and experiments they can do with their classes and instruction on how to build a coherent curriculum for their particular grade level. We also introduce teachers to Contemporary Laboratory Exercises in Astronomy (CLEA), a suite of computer lab exercises that can be used effectively in high school physics classes. For more information, see Funding provided by NSF grant EHR-0227202 (PI: Ronald Stern).

  15. From astronomy to Nature Astronomy (United States)

    Woods, Paul


    Leaving academia was hard, but becoming an editor for Nature Astronomy has been an unexpected delight. That is not to say it is a bed of roses; rather it is the variety and complexity of the challenges of the job that make it so enjoyable.

  16. System and Circuit Design Aspects for CMOS Wireless Handset Receivers

    DEFF Research Database (Denmark)

    Mikkelsen, Jan H.

    The presented work deals with system and circuit design aspects for Complementary Metal Oxide Semiconductor (CMOS) implementations of wireless handset receivers. First, an overview, from a historic perspective, on the use of CMOS in cellular applications is provided. Based on this the tremendous...... developments in CMOS technology are considered and the short-comings from an analog design perspective are evaluated. The lack of high quality passive devices, inductors in particular, is found to be one of the major obstacles in achieving a fully integrated RF design based on CMOS. Following this, an overview...... practice to employ a full separation of different distortion mechanisms. While this approach is very useful when an implementation performance surplus is available it is not an option when a low-cost silicon technology is the target. To manage this, a simple approach that allows all interfering components...

  17. Conceptual design of advanced central receiver power systems sodium-cooled receiver concept. Volume 2, Book 2. Appendices. Final report

    Energy Technology Data Exchange (ETDEWEB)


    The appendices include: (A) design data sheets and P and I drawing for 100-MWe commercial plant design, for all-sodium storage concept; (B) design data sheets and P and I drawing for 100-MWe commercial plant design, for air-rock bed storage concept; (C) electric power generating water-steam system P and I drawing and equipment list, 100-MWe commercial plant design; (D) design data sheets and P and I drawing for 281-MWe commercial plant design; (E) steam generator system conceptual design; (F) heat losses from solar receiver surface; (G) heat transfer and pressure drop for rock bed thermal storage; (H) a comparison of alternative ways of recovering the hydraulic head from the advanced solar receiver tower; (I) central receiver tower study; (J) a comparison of mechanical and electromagnetic sodium pumps; (K) pipe routing study of sodium downcomer; and (L) sodium-cooled advanced central receiver system simulation model. (WHK)

  18. Chinese Astronomy (United States)

    Li, Q.; Murdin, P.


    Astronomy has been a subject of interest to Chinese people since ancient times. As early as the sixteenth century BC, a supernova was recorded on an animal bone used in divination. In ancient China, the main mission for astronomers was to determine the farming seasons and to predict important events for the future according to the phenomena that appeared in the sky. In the minds of rulers in anci...

  19. Computational spherical astronomy (United States)

    Taff, Laurence G.

    The subject of the considered volume is the applied mathematics of spherical astronomy. The book is intended to aid those scientists and engineers, not trained in astrometry, to rapidly master the computational aspects of positional astronomy. Celestial coordinate systems are considered, taking into account the celestial sphere, the horizon system, the equatorial systems, the ecliptic system, the rotational transformations of celestial coordinates, position angle and distance, and special star positions. Other subjects discussed are related to general precession and proper motion, the parallax, the computation of the topocentric place, time systems, photographic astrometry, celestial mechanics, and astronomical catalogs. Attention is given to the power series method for the combined effects of general precession and proper motion, atomic time, the gravitational force, perturbation theory, solar system objects, stars, nonstellar objects, and the linear plate model.

  20. Tools of radio astronomy

    CERN Document Server

    Wilson, Thomas L; Hüttemeister, Susanne


    The recent years have seen breathtaking progress in technology, especially in the receiver and digital technologies relevant for radio astronomy, which has at the same time advanced to shorter wavelengths. This is the updated and completely revised 5th edition of the most used introductory text in radio astronomy. It presents a unified treatment of the entire field from centimeter to sub-millimeter wavelengths. Topics covered include instruments, sensitivity considerations, observational methods and interpretations of the data recorded with both single dishes and interferometers. This text is useful to both students and experienced practicing astronomers. Besides making major updates and additions throughout the book, the authors have re-organized a number of chapters to more clearly separate basic theory from rapidly evolving practical aspects. Further, problem sets have been added at the end of each chapter.

  1. Cryogenic testing and multi-chip module design of a 31.3-45GHz MHEMT MMIC-based heterodyne receiver for radio astronomy (United States)

    Hwang, Yuh-Jing; Chiong, Chau-Ching; Chang, Su-Wei; Wei, Tashun; Wong, Wei-Ting; Lin, Yo-Shen; Chen, Ming-Tang; Wang, Huei; Chang, Hong-Yeh


    A prototype Q-band millimeter-wave heterodyne receiver based on monolithic microwave integrated circuit (MMIC) chips is designed and tested. The MMIC chips, including two three-stage 31.3-45GHz low-noise amplifier (LNA), a diode balanced mixer and a 4-12GHz IF amplifier, are fabricated by a 0.15-um Gallium-Arsenide (GaAs) metamorphic high-electron mobility transistor (MHEMT) foundry service. The MMIC chips are measured by probe in the gain stage. The three-stage 31.3-45GHz LNA MMIC exhibits 31-35dB gain and 2.8-3.5dB noise figure under room temperature environment. The balanced diode mixer with 31.3-45.0GHz RF frequency range and 27.3-33GHz LO frequency range shows 10-13dB conversion loss under 10-dBm LO pumping over 4-12GHz IF frequency range. The LO power of the mixer is provided by a phase-locked GaAs hetero-junction bipolar transistor (HBT) MMIC voltage-controlled oscillator cascaded by a buffer amplifier. The packaged modules of the individual MHEMT MMIC receiver components are designed for testing under 15-20K cryogenic operating temperature to ensure the low-noise performance. A compact multi-chip receiver module design concept will be presented.

  2. A superconducting tunnel junction receiver for submillimeter astronomy, and analysis of observations of post-AGB star molecular envelopes. [AGB (asymptotic giant branch)

    Energy Technology Data Exchange (ETDEWEB)

    Jaminet, P.A.


    A heterodyne receiver designed for astronomical use between 450 and 520 GHz has been constructed. Very low capacitance (C [approximately] 5-10 fF) Superconductor-Insulator-Superconductor (SIS) junctions have been fabricated as the detectors; these junctions lie on the edges of niobium thin films and form Nb-Al-Al[sub 2]O[sub 3]-Al-Nb sandwiches. The double sideband (DSB) receiver noise temperature is between 400 K and 800 K throughout the 70 GHz band. In addition, detailed modelling and analysis of astronomical observations of two post-AGB (Asymptotic Giant Branch) stars was performed. The observations were made with an SIS receiver designed for 345 GHz. CO observations and modelling of the young planetary nebula NGC 7027 provided the best determination yet of its AGB mass loss rate, the first direct evidence for bipolarity in its AGB mass loss, evidence for close hydrodynamic coupling between the planetary nebula and the relic AGB wind, and evidence for evolution in the metallicity of the stellar wind. Observations of the proto-planetary nebula CRL 2688 found evidence for spatially extended fast wind emission with a non-bipolar morphology, and evidence for evolution is elemental abundances in the stellar wind.

  3. Ancient Indian Astronomy in Introductory Texts (United States)

    Narahari Achar, B. N.


    It is customary in introductory survey courses in astronomy to devote some time to the history of astronomy. In the available text books only the Greek contribution receives any attention. Apart from Stonehenge and Chichenitza pictures, contributions from Babylon and China are some times mentioned. Hardly any account is given of ancient Indian astronomy. Even when something is mentioned it is incomplete or incorrect or both. Examples are given from several text books currently available. An attempt is made to correct this situation by sketching the contributions from the earliest astronomy of India, namely Vedaanga Jyotisha.

  4. Radio astronomy

    CERN Document Server

    Alder, Berni


    Methods in Computational Physics, Volume 14: Radio Astronomy is devoted to the role of the digital computer both as a control device and as a calculator in addressing problems related to galactic radio noise. This volume contains four chapters and begins with a technical description of the hardware and the special data-handling problems of using radioheliography, with an emphasis on a selection of observational results obtained with the Culgoora radioheliograph and their significance to solar physics and to astrophysics in general. The subsequent chapter examines interstellar dispersion, i

  5. Random time series in astronomy. (United States)

    Vaughan, Simon


    Progress in astronomy comes from interpreting the signals encoded in the light received from distant objects: the distribution of light over the sky (images), over photon wavelength (spectrum), over polarization angle and over time (usually called light curves by astronomers). In the time domain, we see transient events such as supernovae, gamma-ray bursts and other powerful explosions; we see periodic phenomena such as the orbits of planets around nearby stars, radio pulsars and pulsations of stars in nearby galaxies; and we see persistent aperiodic variations ('noise') from powerful systems such as accreting black holes. I review just a few of the recent and future challenges in the burgeoning area of time domain astrophysics, with particular attention to persistently variable sources, the recovery of reliable noise power spectra from sparsely sampled time series, higher order properties of accreting black holes, and time delays and correlations in multi-variate time series.

  6. Solar system and related topics study by the methods of the low-frequency radio astronomy (United States)

    Konovalenko, A. A.; Rucker, H. O.; Melnik, V. N.; Falkovich, I. S.; Litvinenko, G. V.; Kolyadin, V. L.; Zakharenko, V. V.; Lecacheux, A.; Zarka, Ph.; Reznik, A. P.


    In the present report the possibilities and some results of the high sensitive investigations of the Solar system objects at lowest frequencies have been reviewed. The Sun, Jupiter, Saturn, interplanetary medium, and other objects have been considered. Special attention has been paid to the space weather problem. The stellar-planetary relations have been also investigated, particularly a search of active stars and exo-planets radio emission. During the last years many observations have been performed with the largest decameter arrays UTR-2 (Kharkov, Ukraine) and URAN system (Ukraine) and new receiving equipment. These investigations provided the possibility to get the important information about the fine time-frequency structures of the weak sporadic radio emission. Very good perspectives come into existence in connection to the creation and implementation of the new generation of low-frequency radio telescopes, i.e. LOFAR (the Netherlands), E-LOFAR (European countries), LWA (USA), LSS (France), GURT (Ukraine), etc.

  7. Design and verification of focal plane assembly thermal control system of one space-based astronomy telescope (United States)

    Yang, Wen-gang; Fan, Xue-wu; Wang, Chen-jie; Wang, Ying-hao; Feng, Liang-jie; Du, Yun-fei; Ren, Guo-rui; Wang, Wei; Li, Chuang; Gao, Wei


    One space-based astronomy telescope will observe astronomy objects whose brightness should be lower than 23th magnitude. To ensure the telescope performance, very low system noise requirements need extreme low CCD operating temperature (lower than -65°C). Because the satellite will be launched in a low earth orbit, inevitable space external heat fluxes will result in a high radiator sink temperature (higher than -65°C). Only passive measures can't meet the focal plane cooling specification and active cooling technologies must be utilized. Based on detailed analysis on thermal environment of the telescope and thermal characteristics of focal plane assembly (FPA), active cooling system which is based on thermo-electric cooler (TEC) and heat rejection system (HRS) which is based on flexible heat pipe and radiator have been designed. Power consumption of TECs is dependent on the heat pumped requirements and its hot side temperature. Heat rejection capability of HRS is mainly dependent on the radiator size and temperature. To compromise TEC power consumption and the radiator size requirement, thermal design of FPA must be optimized. Parasitic heat loads on the detector is minimized to reduce the heat pumped demands of TECs and its power consumption. Thermal resistance of heat rejection system is minimized to reject the heat dissipation of TECs from the hot side to the radiator efficiently. The size and surface coating of radiator are optimized to compromise heat reject ion requirements and system constraints. Based on above work, transient thermal analysis of FPA is performed. FPA prototype model has been developed and thermal vacuum/balance test has been accomplished. From the test, temperature of key parts and working parameters of TECs in extreme cases have been acquired. Test results show that CCD can be controlled below -65°C and all parts worked well during the test. All of these verified the thermal design of FPA and some lessons will be presented in this

  8. Initial results for compressive sensing in electronic support receiver systems

    CSIR Research Space (South Africa)

    Du Plessis, WP


    Full Text Available The agile bandwidths of modern radars mean that Electronic Support (ES) receivers require wide instantaneous bandwidths leading to high data rates. Compressive sensing is shown to be a promising technique for reducing data rates for a number...

  9. Torun Radio Astronomy Observatory (United States)

    Murdin, P.


    Torun Center for Astronomy is located at Piwnice, 15 km north of Torun, Poland. A part of the Faculty of Physics and Astronomy of the Nicolaus Copernicus University, it was created by the union of Torun Radio Astronomy Observatory (TRAO) and the Institute of Astronomy on 1 January 1997....

  10. Syllabus Computer in Astronomy (United States)

    Hojaev, Alisher S.


    One of the most important and actual subjects and training courses in the curricula for undergraduate level students at the National university of Uzbekistan is ‘Computer Methods in Astronomy’. It covers two semesters and includes both lecture and practice classes. Based on the long term experience we prepared the tutorial for students which contain the description of modern computer applications in astronomy.The main directions of computer application in field of astronomy briefly as follows:1) Automating the process of observation, data acquisition and processing2) Create and store databases (the results of observations, experiments and theoretical calculations) their generalization, classification and cataloging, working with large databases3) The decisions of the theoretical problems (physical modeling, mathematical modeling of astronomical objects and phenomena, derivation of model parameters to obtain a solution of the corresponding equations, numerical simulations), appropriate software creation4) The utilization in the educational process (e-text books, presentations, virtual labs, remote education, testing), amateur astronomy and popularization of the science5) The use as a means of communication and data transfer, research result presenting and dissemination (web-journals), the creation of a virtual information system (local and global computer networks).During the classes the special attention is drawn on the practical training and individual work of students including the independent one.

  11. Teaching and Learning Astronomy (United States)

    Pasachoff, Jay; Percy, John


    Preface; Part I. Astronomy in the Curriculum Around the World: Preface; 1. Why astronomy is useful and should be included in the school curriculum John R. Percy; 2. Astronomy and mathematics education Rosa M. Ros; 3. Astronomy in the curriculum around the world; 4. Engaging gifted science students through astronomy Robert Hollow; 5. Poster highlights: astronomy in the curriculum around the world; Part II. Astronomy Education Research: Preface; 6. Astronomy education research down under John M. Broadfoot and Ian S. Ginns; 7. A contemporary review of K-16 astronomy education research Janelle M. Bailey and Timothy F. Slater; 8. Implementing astronomy education research Leonarda Fucili; 9. The Astronomy Education Review: report on a new journal Sidney C. Wolff and Andrew Fraknoi; 10. Poster highlights: astronomy education research; Part III. Educating Students: Preface; 11. Textbooks for K-12 astronomy Jay M. Pasachoff; 12. Distance/internet astronomy education David H. McKinnon; 13. Educating students with robotic telescopes - open discussion; 14. Poster highlights - educating students; Part IV. Educating teachers: Preface; 15. Pre-service astronomy education of teachers Mary Kay Hemenway; 16. In-service education of teachers Michèle Gerbaldi; 17. Poster highlights: educating teachers; Part V. Astronomy and Pseudoscience: Preface; 18. Astronomy, pseudoscience and rational thinking Jayant V. Narlikar; 19. Astronomical pseudosciences in North America John R. Percy and Jay M. Pasachoff; Part VI. Astronomy and Culture: Preface; 20. Teaching astronomy in other cultures: archeoastronomy Julieta Fierro; 21. Poster highlights: astronomy and culture; Part VII. Astronomy in Developing Countries: Preface; 22. Astronomy Curriculum for developing countries Case Rijsdijk; 23. Science education resources for the developing countries James C. White II; Part VIII. Public Outreach in Astronomy: Preface; 24. What makes informal education programs successful? Nahide Craig and Isabel

  12. Binocular astronomy

    CERN Document Server

    Tonkin, Stephen


    Binoculars have, for many, long been regarded as an “entry level” observational tool, and relatively few have used them as a serious observing instrument. This is changing! Many people appreciate the relative comfort of two-eyed observing, but those who use binoculars come to realize that they offer more than comfort. The view of the stars is more aesthetically pleasing and therefore binocular observers tend to observe more frequently and for longer periods. Binocular Astronomy, 2nd Edition, extends its coverage of small and medium binoculars to large and giant (i.e., up to 300mm aperture) binoculars and also binoviewers, which brings the work into the realm of serious observing instruments. Additionally, it goes far deeper into the varying optical characteristics of binoculars, giving newcomers and advanced astronomers the information needed to make informed choices on purchasing a pair. It also covers relevant aspects of the physiology of binocular (as in “both eyes”) observation. The first edition ...

  13. Innovation in Astronomy Education (United States)

    Pasachoff, Jay M.; Ros, Rosa M.; Pasachoff, Naomi


    Preface; Part I. General Strategies for Effective Teaching: Introduction; 1. Main objectives of SpS2; 2. Learning astronomy by doing astronomy; 3. Hands-on Universe-Europe; 4. Life on Earth in the atmosphere of the Sun; 5. A model of teaching astronomy to pre-service teachers; 6. How to teach, learn about, and enjoy astronomy; 7. Clickers: a new teaching tool of exceptional promise; 8. Educational opportunities in pro-am collaboration; 9. Teaching history of astronomy to second-year engineering students; 10. Teaching the evolution of stellar and Milky Way concepts through the ages; 11. Educational efforts of the International Astronomical Union; 12. Astronomy in culture; 13. Light pollution: a tool for astronomy education; 14. Astronomy by distance learning; 15. Edible astronomy demonstrations; 16. Amateur astronomers as public outreach partners; 17. Does the Sun rotate around Earth or Earth rotate around the Sun?; 18. Using sounds and sonifications for astronomy outreach; 19. Teaching astronomy and the crisis in science education; 20. Astronomy for all as part of a general education; Poster abstracts; Part II. Connecting Astronomy with the Public: Introduction; 21. A status report from the Division XII working group; 22. Outreach using media; 23. Astronomy podcasting; 24. IAU's communication strategy, hands-on science communication, and the communication of the planet definition discussion; 25. Getting a word in edgeways: the survival of discourse in audiovisual astronomy; 26. Critical evaluation of the new Hall of Astronomy; 27. Revitalizing astronomy teaching through research on student understanding; Poster abstracts; Part III. Effective Use of Instruction and Information Technology: Introduction; 28. ESO's astronomy education program; 29. U.S. student astronomy research and remote observing projects; 30. Global network of autonomous observatories dedicated to student research; 31. Remote telescopes in education: report of an Australian study; 32. Visualizing

  14. Use of Technology Global Positioning System (GPS) Receiver Garmin Etrex Vista as a Tool Navigation


    Paul Jabesh Supit Kilis; Fivtatianti H., SKom. MM Fivtatianti H., SKom. MM


    Global Positioning System (GPS) is a radio system navigation and positioningusing satellites. By using a GPS receiver, we can determine the position of ourexistence. The purpose of this paper is to use a GPS receiver as a navigational tool,which in this study used a GPS receiver is the Garmin eTrex Vista.

  15. The Astronomy Workshop (United States)

    Hamilton, Douglas P.


    {\\bf The Astronomy Workshop} ( is a collection of interactive online educational tools developed for use by students, educators, professional astronomers, and the general public. The more than 20 tools in the Astronomy workshop are rated for ease-of-use, and have been extensively tested in large university survey courses as well as more specialized classes for undergraduate majors and graduate students. Here we briefly describe a few of the available tools. {\\bf Solar Systems Visualizer}: The orbital motions of planets, moons, and asteroids in the Solar System as well as many of the planets in exoplanetary systems are animated at their correct relative speeds in accurate to-scale drawings. Zoom in from the chaotic outer satellite systems of the giant planets all the way to their innermost ring systems. {\\bf Solar System Calculators}: These tools calculate a user-defined mathematical expression simultaneously for all of the Solar System's planets (Planetary Calculator) or moons (Satellite Calculator). Key physical and orbital data are automatically accessed as needed. {\\bf Stellar Evolution}: The "Life of the Sun" tool animates the history of the Sun as a movie, showing students how the size and color of our star has evolved and will evolve over billions of years. In "Star Race," the user selects two stars of different masses and watches their evolution in a split-screeen format that emphasizes the great differences in stellar lifetimes and fates.

  16. Review The Receiver System for the Ooty Wide Field Array

    Indian Academy of Sciences (India)

    contains meta-data containing useful information like sequence number, identification, timestamp, delays and project code. Double buffers are provided using on- chip memory (Block RAMs) so that while one set of 6 frames are being filled in, the previous set of 6 frames are transported to the central processing system. For.

  17. A Distributed, Real-Time Data Monitoring System as Ground Support Equipment for Balloon-Borne Astronomy Experiments (United States)

    Chen, C. M. H.; Baumgartner, W. H.; Cook, W. R.; Davis, A. J.; Harrison, F. A.


    We present a real-time data-monitoring software suite that we developed for the High Energy Focusing Telescope (HEFT). HEFT was one of the first projects to develop focusing mirrors and detectors for hard X-ray astronomy. We deployed these new technologies on the scientific ballooning platform. During a balloon flight, this so-called ‘ground support equipment’ (GSE) allows us to monitor the physical condition of the payload, and to inspect preliminary science data in real time, through displays of tables of frequently updated quantities and their averages, time-series plots, histograms, spectra, and images. Unique from previous implementations of GSE s for other experiments, our system is a server-client network that utilises TCP/IP unicast and UDP multicast to enable multiple, concurrent and independent display clients. Most of the code is in Java, and thus platform-independent. We verified that the software suite works on Linux, Mac OS/X and Windows XP, deployed it in two flight campaigns for use during on-site calibration, pre-launch practice drills, and an observation flight of 24 hours. This system, and individual ideas of its implementation, can be adapted for use in future experiments requiring sophisticated real-time monitoring and data display.

  18. Advances in astronomy and astrophysics

    CERN Document Server

    Kopal, Zdenek


    Advances in Astronomy and Astrophysics, Volume 6 brings together numerous research works on different aspects of astronomy and astrophysics. This volume is composed of five chapters, and starts with the description of improved methods for analyzing and classifying families of periodic orbits in a conservative dynamical system with two degrees of freedom. The next chapter describes the variation of fractional luminosity of distorted components of close binary systems in the course of their revolution, or the accompanying changes in radial velocity. This topic is followed by discussions on vari

  19. Practical astronomy with your calculator

    CERN Document Server

    Duffett-Smith, Peter


    Practical Astronomy with your Calculator, first published in 1979, has enjoyed immense success. The author's clear and easy to follow routines enable you to solve a variety of practical and recreational problems in astronomy using a scientific calculator. Mathematical complexity is kept firmly in the background, leaving just the elements necessary for swiftly making calculations. The major topics are: time, coordinate systems, the Sun, the planetary system, binary stars, the Moon, and eclipses. In the third edition there are entirely new sections on generalised coordinate transformations, nutr

  20. Astrology as Cultural Astronomy (United States)

    Campion, Nicholas

    The practice of astrology can be traced in most if not all human societies, in most time periods. Astrology has prehistoric origins and flourishes in the modern world, where it may be understood as a form of ethnoastronomy - astronomy practiced by the people. The Western tradition, which originated in Mesopotamia and was developed in the Greek world, has been most studied by academics. However, India is also home to a tradition which has survived in a continuous lineage for 2,000 years. Complex systems of astrology also developed in China and Mesoamerica, while all other human societies appear to seek social and religious meaning in the stars.

  1. Astronomy and Politics (United States)

    Steele, John M.

    The relationship between astronomy and politics is a complex but important part of understanding the practice of astronomy throughout history. This chapter explores some of the ways that astronomy, astrology, and politics have interacted, placing particular focus on the way that astronomy and astrology have been used for political purposes by both people in power and people who wish to influence a ruler's policy. Also discussed are the effects that politics has had on the development of astronomy and, in particular, upon the recording and preservation of astronomical knowledge.

  2. Music and Astronomy Under the Stars 2009 (United States)

    Lubowich, D.


    Bring telescopes to where the people are! Music and Astronomy Under the Stars is a three-year NASA-funded astronomy outreach program at community parks during and after music concerts and outdoor family events—such as a Halloween Stars-Spooky Garden Walk. While there have been many astronomy outreach activities and telescope observations at city sidewalks and parks, this program targets a completely different audience: music lovers who are attending summer concerts held in community parks. These music lovers who may never have visited a science museum, planetarium, or star party are exposed to telescope observations and astronomy information with no additional travel costs. Music and Astronomy Under the Stars increased awareness, engagement, and interest in astronomy at classical, pop, rock, and ethnic music concerts. This program includes solar observing before the concerts, telescope observations including a live image projection system, an astronomical video presentation, and astronomy banners/posters. Approximately 500-16,000 people attended each event and 25% to 50% of the people at each event participated in the astronomy program. This program also reached underrepresented and underserved groups (women, minorities, older adults). The target audience (Nassau and Suffolk Counties, New York) is 2,900,000 people, which is larger than combined population of Atlanta, Boston, Denver, Minneapolis, and San Francisco. Although eleven events were planned in 2009, two were canceled due to rain and our largest event, the NY Philharmonic in the Park (attended by 67,000 people in 2008), was cancelled for financial reasons. Our largest event in 2009 was the Tanglewood Music Festival, Lenox MA, attended by 16,000 people where over 5000 people participated in astronomy activities. The Amateur Observers' Society of New York assisted with the NY concerts and the Springfield STARS astronomy club assisted at Tanglewood. In 2009 over 15,000 people participated in astronomy

  3. Ancient Chinese Astronomy - An Overview (United States)

    Shi, Yunli

    Documentary and archaeological evidence testifies the early origin and continuous development of ancient Chinese astronomy to meet both the ideological and practical needs of a society largely based on agriculture. There was a long period when the beginning of the year, month, and season was determined by direct observation of celestial phenomena, including their alignments with respect to the local skyline. As the need for more exact study arose, new instruments for more exact observation were invented and the system of calendrical astronomy became entirely mathematized.

  4. Advances in astronomy and astrophysics

    CERN Document Server

    Kopal, Zdenek


    Advances in Astronomy and Astrophysics, Volume 1 brings together numerous research works on different aspects of astronomy and astrophysics. This book is divided into five chapters and begins with an observational summary of the shock-wave theory of novae. The subsequent chapter provides the properties and problems of T tauri stars and related objects. These topics are followed by discussions on the structure and origin of meteorites and cosmic dust, as well as the models for evaluation of mass distribution in oblate stellar systems. The final chapter describes the methods of polarization mea

  5. African Cultural Astronomy

    CERN Document Server

    Holbrook, Jarita C; Medupe, R. Thebe; Current Archaeoastronomy and Ethnoastronomy research in Africa


    Astronomy is the science of studying the sky using telescopes and light collectors such as photographic plates or CCD detectors. However, people have always studied the sky and continue to study the sky without the aid of instruments this is the realm of cultural astronomy. This is the first scholarly collection of articles focused on the cultural astronomy of Africans. It weaves together astronomy, anthropology, and Africa. The volume includes African myths and legends about the sky, alignments to celestial bodies found at archaeological sites and at places of worship, rock art with celestial imagery, and scientific thinking revealed in local astronomy traditions including ethnomathematics and the creation of calendars. Authors include astronomers Kim Malville, Johnson Urama, and Thebe Medupe; archaeologist Felix Chami, and geographer Michael Bonine, and many new authors. As an emerging subfield of cultural astronomy, African cultural astronomy researchers are focused on training students specifically for do...

  6. A digital receiver with fast frequency- and gain-switching capabilities for MRI systems. (United States)

    Ruipeng, Ning; Yidong, Dai; Guang, Yang; Gengying, Li


    In this article, two issues pertaining to MRI digital receivers are addressed. One is the maintenance of phase coherence between the transmitter and the receiver-an effective solution is proposed, in which the receiver frequency is switched synchronously with the transmitter frequency. The other is the dynamic range of the receiver-gain-switching technique is utilized to improve the dynamic range. To meet the hardware requirements of these solutions, a digital receiver with fast frequency- and gain-switching capabilities was implemented. The primary components of the proposed digital receiver are a variable gain amplifier, a high-speed analog-to-digital converter and a single-chip digital receiver core. The radio-frequency magnetic resonance signal is directly sampled by the analog-to-digital converter and processed in the digital receiver core. By pre-storing the receiver waveform in the on-board SDRAM, the frequency and gain of the receiver may be switched very quickly. The performance of the proposed digital receiver is verified by embedding it in an imaging spectrometer. It is then demonstrated by conducting experiments on a home-built 0.3-T magnetic resonance imaging system. The results show that the phase coherence between the transmitter and the receiver and the dynamic range of the receiver are greatly improved. Consequently, the proposed digital receiver may be useful for obtaining multiple-slice two-dimensional magnetic resonance images with very high resolution.

  7. Acceptance test report for the 241-SY-101 Flexible Receiver Gamma Detector System

    Energy Technology Data Exchange (ETDEWEB)

    Dowell, J.L.


    This Acceptance Test Report is for the 241-SY-101 Flexible Receiver Gamma Detector System. This test verified that the data logger and data converter for the gamma detector system functions as intended.

  8. The Astro-Wise system: a federated information accumulator for astronomy

    NARCIS (Netherlands)

    Valentijn, Edwin A.; Verdoes Kleijn, Gijs


    The Astro-Wise consortium has designed a new paradigm, ‘Awe‘, and implemented a fully scalable and distributed information system to overcome the huge information avalanche in wide-field astronomical imaging Surveys.

  9. Engineering satellite-based navigation and timing global navigation satellite systems, signals, and receivers

    CERN Document Server

    Betz, J


    This book describes the design and performance analysis of satnav systems, signals, and receivers. It also provides succinct descriptions and comparisons of all the world’s satnav systems. Its comprehensive and logical structure addresses all satnav signals and systems in operation and being developed. Engineering Satellite-Based Navigation and Timing: Global Navigation Satellite Systems, Signals, and Receivers provides the technical foundation for designing and analyzing satnav signals, systems, and receivers. Its contents and structure address all satnav systems and signals: legacy, modernized, and new. It combines qualitative information with detailed techniques and analyses, providing a comprehensive set of insights and engineering tools for this complex multidisciplinary field. Part I describes system and signal engineering including orbital mechanics and constellation design, signal design principles and underlying considerations, link budgets, qua tifying receiver performance in interference, and e...

  10. Challenges in Astronomy Education (United States)

    De Greve, Jean-Pierre


    Astronomy is an attractive subject for education. It deals with fascination of the unknown and the unreachable, yet is uses tools, concepts and insights from various fundamental sciences such as mathematics, physics, chemistry, biology. Because of this it can be well used for introducing sciences to young people and to raise their interest in further studies in that direction. It is also an interesting subject for teaching as its different aspects (observation techniques, theory, data sampling and analysis, modelling,?) offer various didactical approaches towards different levels of pupils, students and different backgrounds. And it gives great opportunities to teach and demonstrate the essence of scientific research, through tutorials and projects. In this paper we discuss some of the challenges education in general, and astronomy in particular, faces in the coming decades, given the major geophysical and technological changes that can be deducted from our present knowledge. This defines a general, but very important background in terms of educational needs at various levels, and in geographical distribution of future efforts of the astronomical community. Special emphasis will be given to creative approaches to teaching, to strategies that are successful (such as the use of tutorials with element from computer games), and to initiatives complementary to the regular educational system. The programs developed by the IAU will be briefly highlighted.

  11. The control system of the 3 mm band SIS receiver for the Sardinia Radio Telescope (United States)

    Ladu, A.; Ortu, P.; Saba, A.; Pili, M.; Guadiomonte, F.; Navarrini, A.; Urru, E.; Pisanu, T.; Valente, G.; Marongiu, P.; Mazzarella, G.


    We present the control system of the 84-116 GHz (3 mm band) Superconductor-Insulator-Superconductor (SIS) heterodyne receiver to be installed at the Gregorian focus of the Sardinia Radio Telescope (SRT). The control system is based on a single-board computer from Raspberry, on microcontrollers from Arduino, and on a Python program for communication between the receiver and the SRT antenna control software, which remotely controls the backshorttuned SIS mixer, the receiver calibration system and the Local Oscillator (LO) system.

  12. Performance of Turbo Interference Cancellation Receivers in Space-Time Block Coded DS-CDMA Systems

    Directory of Open Access Journals (Sweden)

    Emmanuel Oluremi Bejide


    Full Text Available We investigate the performance of turbo interference cancellation receivers in the space time block coded (STBC direct-sequence code division multiple access (DS-CDMA system. Depending on the concatenation scheme used, we divide these receivers into the partitioned approach (PA and the iterative approach (IA receivers. The performance of both the PA and IA receivers is evaluated in Rayleigh fading channels for the uplink scenario. Numerical results show that the MMSE front-end turbo space-time iterative approach receiver (IA effectively combats the mixture of MAI and intersymbol interference (ISI. To further investigate the possible achievable data rates in the turbo interference cancellation receivers, we introduce the puncturing of the turbo code through the use of rate compatible punctured turbo codes (RCPTCs. Simulation results suggest that combining interference cancellation, turbo decoding, STBC, and RCPTC can significantly improve the achievable data rates for a synchronous DS-CDMA system for the uplink in Rayleigh flat fading channels.

  13. Coherent receiving efficiency in satellite-ground coherent laser communication system based on analysis of polarization (United States)

    Hao, Shiqi; Zhang, Dai; Zhao, Qingsong; Wang, Lei; Zhao, Qi


    Aimed at analyzing the coherent receiving efficiency of a satellite-ground coherent laser communication system, polarization state of the received light is analyzed. We choose the circularly polarized, partially coherent laser as transmitted light source. The analysis process includes 3 parts. Firstly, an theoretical model to analyze received light's polarization state is constructed based on Gaussian-Schell model (GSM) and cross spectral density function matrix. Then, analytic formulas to calculate coherent receiving efficiency are derived in which both initial ellipticity modification and deflection angle between polarization axes of the received light and the intrinsic light are considered. At last, numerical simulations are operated based on our study. The research findings investigate variations of polarization state and obtain analytic formulas to calculate the coherent receiving efficiency. Our study has theoretical guiding significances in construction and optimization of satellite-ground coherent laser communication system.

  14. Armenian Archaeoastronomy and Astronomy in Culture (United States)

    Mickaelian, Areg M.; Farmanyan, Sona V.


    A review is given on archaeoastronomy in Armenia and astronomical knowledge reflected in the Armenian culture. Astronomy in Armenia was popular since ancient times and Armenia is rich in its astronomical heritage, such as the names of the constellations, ancient observatories, Armenian rock art (numerous petroglyphs of astronomical content), ancient and medieval Armenian calendars, astronomical terms and names used in Armenian language since II-I millennia B.C., records of astronomical events by ancient Armenians (e.g. Halley's comet in 87 B.C., supernovae explosion in 1054), the astronomical heritage of the Armenian medieval great thinker Anania Shirakatsi's (612-685), medieval sky maps and astronomical devices by Ghukas (Luca) Vanandetsi (XVII-XVIII centuries) and Mkhitar Sebastatsi (1676-1749), etc. For systemization and further regular studies, we have created a webpage devoted to Armenian archaeoastronomical matters at Armenian Astronomical Society (ArAS) website. Issues on astronomy in culture include astronomy in ancient Armenian cultures, ethnoastronomy, astronomy in Armenian religion and mythology, astronomy and astrology, astronomy in folklore and poetry, astronomy in arts, astrolinguistics and astroheraldry. A similar webpage for Astronomy in Armenian Culture is being created at ArAS website and a permanent section "Archaeoastronomy and Astronomy in Culture" has been created in ArAS Electronic Newsletter. Several meetings on this topic have been organized in Armenia during 2007-2014, including the archaeoastronomical meetings in 2012 and 2014, and a number of books have been published. Several institutions are related to these studies coordinated by Byurakan Astrophysical Observatory (BAO) and researchers from the fields of astronomy, history, archaeology, literature, linguistics, etc. are involved.

  15. The Unified Astronomy Thesaurus


    Accomazzi, Alberto; Gray, Norman; Erdmann, Chris; Biemesderfer, Chris; Frey, Katie; Soles, Justin


    The Unified Astronomy Thesaurus (UAT) is an open, interoperable and community-supported thesaurus which unifies the existing divergent and isolated Astronomy & Astrophysics vocabularies into a single high-quality, freely-available open thesaurus formalizing astronomical concepts and their inter-relationships. The UAT builds upon the existing IAU Thesaurus with major contributions from the astronomy portions of the thesauri developed by the Institute of Physics Publishing, the American Institu...

  16. Radiometric calibration of wide-field camera system with an application in astronomy (United States)

    Vítek, Stanislav; Nasyrova, Maria; Stehlíková, Veronika


    Camera response function (CRF) is widely used for the description of the relationship between scene radiance and image brightness. Most common application of CRF is High Dynamic Range (HDR) reconstruction of the radiance maps of imaged scenes from a set of frames with different exposures. The main goal of this work is to provide an overview of CRF estimation algorithms and compare their outputs with results obtained under laboratory conditions. These algorithms, typically designed for multimedia content, are unfortunately quite useless with astronomical image data, mostly due to their nature (blur, noise, and long exposures). Therefore, we propose an optimization of selected methods to use in an astronomical imaging application. Results are experimentally verified on the wide-field camera system using Digital Single Lens Reflex (DSLR) camera.

  17. Space and astronomy

    CERN Document Server

    Kirkland, Kyle


    Some daring explorers like to study distant frontiers by venturing out into them, but others prefer to study them by bringing them, or representative samples, a little closer to the lab. Both options are pursued in the fields of space and astronomy. Space exploration and astronomy are intricately linked and are examined in-depth in this guide. Dedicated to the scientists who explore the frontiers of space and astronomy-and the results of their unfamiliar findings-each chapter in Space and Astronomy explores one of the frontiers of this science. The development of technology, such as rocket pro

  18. Visual lunar and planetary astronomy

    CERN Document Server

    Abel, Paul G


    With the advent of CCDs and webcams, the focus of amateur astronomy has to some extent shifted from science to art. The object of many amateur astronomers is now to produce “stunning images” that, although beautiful, are not intended to have scientific merit. Paul Abel has been addressing this issue by promoting visual astronomy wherever possible – at talks to astronomical societies, in articles for popular science magazines, and on BBC TV’s The Sky at Night.   Visual Lunar and Planetary Astronomy is a comprehensive modern treatment of visual lunar and planetary astronomy, showing that even in the age of space telescopes and interplanetary probes it is still possible to contribute scientifically with no more than a moderately priced commercially made astronomical telescope.   It is believed that imaging and photography is somehow more objective and more accurate than the eye, and this has led to a peculiar “crisis of faith” in the human visual system and its amazing processing power. But by anal...

  19. The history of the International Astronomy Olympiad (United States)

    Gavrilov, Michael G.; Salnikov, Igor V.; Vaesterberg, Anders R.


    The International Astronomy Olympiad (IAO) was founded in the 1990s as an annual scientific educating event for students of the junior high school classes. Starting from 4 teams at the 1st event in 1996 the Olympiad includes more than 20 countries nowadays. The style of the problems of IAO is aimed at developing the imagination, creativity and independent thinking. They stimulate the students to recognize the problem independently, to choose a model, to make necessary suppositions, estimations, to conduct multiway calculations or logic operations. The Asian-Pacific Astronomy Olympiad was founded as a ``daughter'' (``affiliated'') olympiad in system of the International Astronomy Olympiad in 2005.

  20. Advances in astronomy and astrophysics 9

    CERN Document Server

    Kopal, Zdenek


    Advances in Astronomy and Astrophysics, Volume 9 covers reviews on the advances in astronomy and astrophysics. The book presents reviews on the Roche model and its applications to close binary systems. The text then describes the part played by lunar eclipses in the evolution of astronomy; the classical theory of lunar eclipses; deviations from geometrical theory; and the methods of photometric observations of eclipses. The problems of other phenomena related in one way or another to lunar eclipses are also considered. The book further tackles the infrared observation on the eclipsed moon, as

  1. High Sensitivity, Radiation Hard InGaAs LIDAR Receiver for Unmanned Aircraft Systems (UAS) Project (United States)

    National Aeronautics and Space Administration — NASA has a requirement for a large-area, high-quantum-efficiency, high-throughput optical receiver for ground-, air-, and space-based LIDAR systems. A...

  2. Design and Construction of a New 1420 MHz Receiver System for a 12-meter Radio Telescope (United States)

    Lemley, Cameron; Castelaz, M. W.


    During the summer of 2013, a new 1420 MHz receiver system was designed and constructed for the 12-meter radio telescope at the Pisgah Astronomical Research Institute (PARI). The new radio receiver system consists of a feedhorn (which is a duplicate of the feedhorn that is currently installed on PARI’s 4.6-meter radio telescope), a low-noise amplifier, a bandpass filter, a downconverter, a SpectraCyber 1420 MHz Hydrogen Line Spectrometer, CommScope CNT-600 braided coaxial cable, and a power supply. Each component was individually tested on the preexisting 4.6-meter radio telescope receiver system before being installed on the 12-meter telescope. This testing process revealed that the spectrometer that was intended for use in the new 12-meter receiver system would require 12-bit software, which was acquired soon thereafter. The new receiver system was then assembled on a rolling cart for further testing. After the 1420 MHz receiver system was moved outside, it successfully detected its first extraterrestrial radio signal. The next step of this project was the installation of the feedhorn at the focus of the 12-meter parabolic reflector and the mounting of the additional receiver system components inside the radio frequency (RF) room of the 12-meter telescope. Following its installation on the 12-meter telescope, the new receiver system was connected to the PARI network via ethernet using a device called a SitePlayer Telnet. The 12-meter telescope was focused by taking continuum scans of Virgo A during its meridian crossing. The positioning of the feedhorn had to be adjusted several times before the new radio receiver system was precisely focused. After focusing the 12-meter telescope, spectra were taken of both the Orion Nebula and the Crab Nebula to test the abilities of the new 1420 MHz receiver system. As a final test of both the angular resolution and time resolution of the new radio receiver system, the 12-meter telescope was used to observe the pulsar PSR J

  3. Real-time environmental inversion using a network of light receiving systems


    Soares, C.; Jesus, S.M.


    This paper reports preliminary environmental inversion results of acoustic data collected simultaneously at two receiving systems during the RADAR’07 sea trial. These receiving systems have communication capabilities that allow for transfering acoustic and telemetric data to a base station with processing capabilities in order to produce environmental estimates during the acoustic experiment. During a large part of the experiment estimates on the temperature field appear to agree with c...

  4. Astronomy for beginners

    CERN Document Server

    Becan, Jeff


    Astronomy For Beginners is a friendly and accessible guide to our universe, our galaxy, our solar system and the planet we call home. Each year as we cruise through space on this tiny blue-green wonder, a number of amazing and remarkable events occur. For example, like clockwork, we'll run head-on into asteroid and cometary debris that spreads shooting stars across our skies. On occasion, we'll get to watch the disk of the Moon passing the Sun, casting its shadow on the face of the Earth, and sometimes we'll get to watch our own shadow as it glides across the face of the Moon. The Sun's path w

  5. NMR transmit-receive system with short recovery time and effective isolation (United States)

    Jurga, K.; Reynhardt, E. C.; Jurga, S.

    A transmit-receive system with a short recovery time and excellent isolation has been developed. The system operates in conjunction with an ENI Model 3200L broadband amplifier and a spin-lock NMR pulse spectrometer. The system has been tested in the frequency range 5.5 to 52 MHz and seems not to generate any background noise.

  6. Interdisciplinary Astronomy Activities (United States)

    Nerantzis, Nikolaos; Mitrouda, Aikaterini; Reizopoulou, Ioanna; Sidiropoulou, Eirini; Hatzidimitriou, Antonios


    On November 9th, 2015, three didactical hours were dedicated to Interdisciplinary Astronomy Activities ( Our students and their teachers formed three groups and in rotation, were engaged with the following activities: (a) viewing unique images of the Cosmos in the mobile planetarium STARLAB (, (b) watching the following videos: Journey to the end of the universe (, Rosetta update (, The Solar System (, Ambition the film ( in the school's library. Students and teachers were informed about our solar system, the Rosetta mission, the universe, etc. and (c) tactile activities such as Meet our home and Meet our neighbors (, and the creation of planets' 3D models (Geology-Geography A' Class Student's book, pg.15). With the activities above we had the pleasure to join the Cosmic Light Edu Kit / International Year of Light 2015 program. After our Interdisciplinary Astronomy Activities, we did a "small" research: our students had to fill an evaluation about their educational gains and the results can be found here Moreover, we discussed about Big Ideas of Science ( and through the "big" impact of the Rosetta mission & the infinity of our universe, we print posters with relevant topics and place them to the classrooms. We thank Rosa Doran (Nuclio - President of the Executive Council) for her continuous assistance and support on innovative science teaching proposals. She is an inspiration.

  7. Biographical Index of Astronomy (United States)

    Brüggenthies, Wilhelm; Dick, Wolfgang R.

    This inventory lists for more than 16,000 astronomers and other persons with relation to astronomy their dates of life and biographical resources (books, papers, encyclopedic entries, obituaries, etc.). Besides professional and amateur astronomers, the index contains numerous mathematicians, physicists, geodesists, geologists, geophysicists, meteorologists, globe and instrument makers, pioneers of space flight, patrons of astronomy, and others.

  8. Rubric Sorting Astronomy Essays (United States)

    Len, P. M.


    Student essays on introductory astronomy exams can be consistently and efficiently graded by a single instructor, or by multiple graders for a large class. This is done by constructing a robust outcome rubric while sorting exams into separate stacks, then checking each stack for consistency. Certain online resources readily provide primary source prompts for writing astronomy exam essay questions.

  9. Astronomy and astrophysics

    National Research Council Canada - National Science Library

    National Research Council Staff


    ... for the Decades 1995 to 2015 Astronomy and Astrophysics Task Group on Astronomy and Astrophysics Space Science Board Commission on Physical Sciences, Mathematics, and Resources National Research Council NATIONAL ACADEMY PRESS Washington, D.C. 1988 Copyrightoriginal retained, the be not from cannot book, paper original however, for version formatting, author...

  10. High energy particle astronomy. (United States)

    Buffington, A.; Muller, R. A.; Smith, L. H.; Smoot, G. F.


    Discussion of techniques currently used in high energy particle astronomy for measuring charged and neutral cosmic rays and their isotope and momentum distribution. Derived from methods developed for accelerator experiments in particle physics, these techniques help perform important particle astronomy experiments pertaining to nuclear cosmic ray and gamma ray research, electron and position probes, and antimatter searches.

  11. Highlights of Astronomy, Vol. 16 (United States)

    Montmerle, Thierry


    Part I. Invited Discourses: 1. The Herschel view of star formation; 2. Past, present and future of Chinese astronomy; 3. The zoo of galaxies; 4. Supernovae, the accelerating cosmos, and dark energy; Part II. Joint Discussion: 5. Very massive stars in the local universe; 6. 3-D views of the cycling Sun in stellar context; 7. Ultraviolet emission in early-type galaxies; 8. From meteors and meteorites to their parent bodies: current status and future developments; 9. The connection between radio properties and high-energy emission in AGNs; 10. Space-time reference systems for future research; Part III. Special Sessions: 11. Origin and complexity of massive star clusters; 12. Cosmic evolution of groups and clusters of galaxies; 13. Galaxy evolution through secular processes; 14. New era for studying interstellar and intergalactic magnetic fields; 15. The IR view of massive stars: the main sequence and beyond; 16. Science with large solar telescopes; 17. The impact hazard: current activities and future plans; 18. Calibration of star-formation rate measurements across the electromagnetic spectrum; 19. Future large scale facilities; 20. Dynamics of the star-planet relations strategic plan and the Global Office of Astronomy for Development; 21. Strategic plan and the Global Office of Astronomy for Development; 22. Modern views of the interstellar medium; 23. High-precision tests of stellar physics from high-precision photometry; 24. Communicating astronomy with the public for scientists; 25. Data intensive astronomy; 26. Unexplained spectral phenomena in the interstellar medium; 27. Light pollution: protecting astronomical sites and increasing global awareness through education.

  12. Development of Laser, Detector, and Receiver Systems for an Atmospheric CO2 Lidar Profiling System (United States)

    Ismail, Syed; Koch, Grady; Abedin, Nurul; Refaat, Tamer; Rubio, Manuel; Singh, Upendra


    A ground-based Differential Absorption Lidar (DIAL) is being developed with the capability to measure range-resolved and column amounts of atmospheric CO2. This system is also capable of providing high-resolution aerosol profiles and cloud distributions. It is being developed as part of the NASA Earth Science Technology Office s Instrument Incubator Program. This three year program involves the design, development, evaluation, and fielding of a ground-based CO2 profiling system. At the end of a three-year development this instrument is expected to be capable of making measurements in the lower troposphere and boundary layer where the sources and sinks of CO2 are located. It will be a valuable tool in the validation of NASA Orbiting Carbon Observatory (OCO) measurements of column CO2 and suitable for deployment in the North American Carbon Program (NACP) regional intensive field campaigns. The system can also be used as a test-bed for the evaluation of lidar technologies for space-application. This DIAL system leverages 2-micron laser technology developed under a number of NASA programs to develop new solid-state laser technology that provides high pulse energy, tunable, wavelength-stabilized, and double-pulsed lasers that are operable over pre-selected temperature insensitive strong CO2 absorption lines suitable for profiling of lower tropospheric CO2. It also incorporates new high quantum efficiency, high gain, and relatively low noise phototransistors, and a new receiver/signal processor system to achieve high precision DIAL measurements.

  13. Astronomy Village: Innovative Uses of Planetary Astronomy Images and Data (United States)

    Croft, S. K.; Pompea, S. M.


    Teaching and learning science is best done by hands-on experience with real scientific data and real scientific problems. Getting such experiences into public and home-schooling classrooms is a challenge. Here we describe two award-winning multimedia products that embody one successful solution to the problem: Astronomy Village: Investigating the Universe, and Astronomy Village: Investigating the Solar System. Each Village provides a virtual environment for inquiry-based scientific exploration of ten planetary and astronomical problems such as ``Mission to Pluto'' and ``Search for a Supernova.'' Both Villages are standards-based and classroom tested. Investigating the Solar System is designed for middle and early high school students, while Investigating the Universe is at the high school and introductory college level. The objective of both Villages is to engage students in scientific inquiry by having them acquire, explore, and analyze real scientific data and images drawn from real scientific problems.

  14. Performance simulation of heterodyne synchronous receiving system in coherent optical communication (United States)

    Zheng, BaiChao; Tong, ShouFeng


    Coherent optical communication technology is currently a hotpot research of communication. Coherent optical communication heterodyne synchronous receiving system is researched. The basic principle of coherent optical communication is introduced in briefly, the heterodyne synchronous receiving system is established in the basis of the principle. A simulation model, charactered as Synchronous receiving system of Coherent Heterodyne, was rightly set up. In addition, with regarding actual device parameters as reference, and under the situation of 2.5Gbps communication rate and 10km as communication distance, Optisystem was operating to accomplish simulation analysis for capacity of this system in different signal-radiation rate and distinguish weather condition. The consequence of simulation demonstrated: as the receiving sensitivity is relatively high when compared communication system of coherent heterodyne to that of IM/DD, the coherent optical communication system has lower requirement to signal rate of radiated laser in the same condition. Consequently, it can be concluded that coherent heterodyne system has high receiving sensitivity, and strong capacity of resisting disturbance, moreover it is appropriately communicated in channel with relatively high disturbance, it possesses great advantages to IM/DD method in atmosphere channel which has strong disturbance.

  15. Reduced-Complexity Radio Architectures for Enhanced Receive Selection Combining in Multiuser Diversity Systems

    Directory of Open Access Journals (Sweden)

    Elpiniki P. Tsakalaki


    Full Text Available Although antenna selection is a simple and efficient technique for enhancing the downlink performance of multiuser diversity systems, the large antenna interelement spacing required for achieving spatial diversity is prohibitive for user terminals due to size restrictions. In order to allay this problem, we propose miniaturized switched beam receiver designs assisted by low-cost passive reflectors. Unlike conventional spatial receive diversity systems, the proposed angular diversity architectures occupy a small volume whereas the antenna system properties are optimized by controlling the strong reactive fields present at small dimensions. The systems are designed for maximum antenna efficiency and low interbeam correlation, thus yielding N practically uncorrelated receive diversity branches. The simulation results show that the proposed enhanced diversity combining systems improve the average throughput of a multiuser network outperforming classical antenna selection especially for small user populations and compact user terminal size.

  16. Reduced-complexity radio architectures for enhanced receive selection combining in multiuser diversity systems

    DEFF Research Database (Denmark)

    Tsakalaki, Elpiniki; Alrabadi, Osama; Papadias, Constantinos B.


    Although antenna selection is a simple and efficient technique for enhancing the downlink performance of multiuser diversity systems, the large antenna interelement spacing required for achieving spatial diversity is prohibitive for user terminals due to size restrictions. In order to allay...... this problem, we propose miniaturized switched beam receiver designs assisted by low-cost passive reflectors. Unlike conventional spatial receive diversity systems, the proposed angular diversity architectures occupy a small volume whereas the antenna system properties are optimized by controlling the strong...... reactive fields present at small dimensions. The systems are designed for maximum antenna efficiency and low interbeam correlation, thus yielding N practically uncorrelated receive diversity branches. The simulation results show that the proposed enhanced diversity combining systems improve the average...

  17. New Trends in Astronomy Education: a ``Mapping" Strategy in Teaching and Learning Astronomy (United States)

    Gulyaev, S.


    The application of a concept of educational ``science maps" to astronomy education is discussed. By analogy with geographical maps, scales of educational science maps -- scales of integration -- are introduced. In astronomy education, scale A represents the level of branches and fields of astronomy and astrophysics, where interconnections between various astronomical disciplines are shown. Scale B represents the level of hypotheses and theories, encompassing a significant segment of a field of astronomy. Scale C represents the level of structures and internal hierarchies, encompassing the ``geography" and ``anatomy" of the material systems and objects essential for a given astronomical discipline, as well as the principal notions and concepts it uses. Science maps of different scales are illustrated with initial examples exploring the application of this methodology in astronomy and astrophysics.

  18. 2009 International Year of Astronomy (IYA2009) (United States)

    Wiseman, Jennifer


    400 years ago, Galileo first turned a telescope to the sky, and to honor that historic moment, 2009 has been designated the International Year of Astronomy (IYA2009). This session will feature two scientists who have used the telescope to understand our solar system and well beyond to yield fantastic new discoveries. Jennifer Wiseman will share the work she does with NASA, presenting beautiful and tantalizing images from the Hubble Space Telescope and discussing how space astronomy can inspire all ages.

  19. A Construction of the Real Time Monitoring System of the Solar Radio Disturbance: II. 2.8GHz Radio Receiver and Radio Environment

    Directory of Open Access Journals (Sweden)

    Yonggi Kim


    Full Text Available As the second step of the real time monitoring system of the solar radio disturbance, we constructed a 2.8 GHz radio receiver with 500 MHz bandwith. Using the control and observing system (Yoon et al.~2004, we observed the Sun, and found some frequencies, which disturb the Solar radio flux to be observed. DMB and aiport control frequencies are identified as responsible for this disturbance. As well as the testing the receiver, the measurment of the radio environment at 2.8 GHz with 500 MHz bandwith are carried out around Chungbuk National University. In fact, the radio power of the two frequencies, 2.649 GHz and 2.874 GHz is so high that we can not observe the Solar radio signal at 2.8 GHz. We report some results of this measurment and suggest the method to overcome this problem. We conclude also that the frequecies, which are important for the astronomy, should be protected in the future.

  20. V-band low-noise integrated circuit receiver. [for space communication systems (United States)

    Chang, K.; Louie, K.; Grote, A. J.; Tahim, R. S.; Mlinar, M. J.; Hayashibara, G. M.; Sun, C.


    A compact low-noise V-band integrated circuit receiver has been developed for space communication systems. The receiver accepts an RF input of 60-63 GHz and generates an IF output of 3-6 GHz. A Gunn oscillator at 57 GHz is phaselocked to a low-frequency reference source to achieve high stability and low FM noise. The receiver has an overall single sideband noise figure of less than 10.5 dB and an RF to IF gain of 40 dB over a 3-GHz RF bandwidth. All RF circuits are fabricated in integrated circuits on a Duroid substrate.

  1. Optimum receiver filter for a noise-based frequency-offset modulation system

    NARCIS (Netherlands)

    Bilal, Ibrahim; Meijerink, Arjan; Bentum, Marinus Jan


    A frequency-offset transmit-reference (TR) system using a noise carrier is considered in additive white Gaussian noise. The system is studied for any given spectrum of the noise carrier, and the expression for the transfer function of an optimal receiver front-end filter is derived. The maximum

  2. Experimental analysis of THz receiver performance in 80 Gbit/s communication system

    DEFF Research Database (Denmark)

    Jia, Shi; Yu, Xianbin; Hu, Hao


    We experimentally analyze the performance of Schottky mixer-based THz receiver in a high-speed THz wireless transmission system incorporating an ultra-broadband uni-travelling carrier photodiode (UTC-PD) as photo-mixing emitter. The multi-channel photonic THz wireless system operates in the 375...

  3. Solar receiver heliostat reflector having a linear drive and position information system (United States)

    Horton, Richard H.


    A heliostat for a solar receiver system comprises an improved drive and control system for the heliostat reflector assembly. The heliostat reflector assembly is controllably driven in a predetermined way by a light-weight drive system so as to be angularly adjustable in both elevation and azimuth to track the sun and efficiently continuously reflect the sun's rays to a focal zone, i.e., heat receiver, which forms part of a solar energy utilization system, such as a solar energy fueled electrical power generation system. The improved drive system includes linear stepping motors which comprise low weight, low cost, electronic pulse driven components. One embodiment comprises linear stepping motors controlled by a programmed, electronic microprocessor. Another embodiment comprises a tape driven system controlled by a position control magnetic tape.

  4. Learning Exercises in Astronomy for Elementary Students (United States)

    Jacoby, Suzanne H.


    Astronomers from the Tucson based National Optical Astronomy Observatories and students in grades K-3 at the Satori School are learning from each other about astronomy and science education. This project is partially funded by a NASA IDEA Grant (Initiative to Develop Education through Astronomy). NOAO astronomers are working with the students and teachers over a series of 12 weeks to present basic concepts in planetary and solar astronomy. Each presentation includes a discussion with the astronomers and a hands-on active learning exercise. Topics presented include: The Living Solar System, Impacts and Hazards, Comets, Space Resources, The Natural Sun, The Sun as a Clock, Sunspots and Solar Rotation, and Solar Music - Helioseismology. Lessons learned, by students and astronomers, will be presented and printed lesson modules available for distribution.

  5. A Millimeter-Wave Quasi-Optical Circuit for Compact Triple-Band Receiving System (United States)

    Han, Seog-Tae; Lee, Jung-Won; Lee, Bangwon; Chung, Moon-Hee; Lee, Sung-Mo; Je, Do-Heung; Wi, Seog-Oh; Goldsmith, Paul F.


    A novel receiver optical system designed for Korean VLBI Network (KVN) has been used for conducting simultaneous millimeter-wave very long baseline interferometry (VLBI) observations at frequencies of 22, 43, 86, and 129 GHz. This multi-frequency band receiver system has been effective in compensation of atmospheric phase fluctuation by unique phase referencing technique in mm-VLBI observations. However, because the original optics system incorporated individual cryogenic receivers in separate cryostats, a rather bulky optical bench of size about 2600 mm x 2300 mm x 60 mm was required. To circumvent difficulties in installation and beam alignment, an integrated quasi-optical circuit incorporating a more compact triple-band receiver in single cryostat is proposed in this paper. The recommended frequency bands of the improved triple-band receiver are K(18-26 GHz) band, Q(35-50 GHz) band, and W(85-115 GHz) band. A frequency-independent quasi-optical circuit for triple band is adopted to obtain constant aperture efficiency as a function of the observed frequencies. The simulation results show that total aperture efficiency of each recommended frequency band is maintained almost constant within 1%. We present the design details of the compact wideband quasi-optical circuit and the triple-band receiver optimized for simultaneous multi-frequency observations.

  6. Teaching Astronomy with Technology (United States)

    Austin, Carmen; Impey, Chris David; Wenger, Matthew


    Students today are expected to have access to computers and the Internet. Students young and old, in school and out of school, are interested in learning about astronomy, and have computers to use for this. Teach Astronomy is a website with a comprehensive digital astronomy textbook freely available to students and educators. In addition to the textbook, there are astronomy Wikipedia articles, image archives from Astronomy Picture of the Day and AstroPix, and video lectures covering all topics of astronomy. Teach Astronomy has a unique search tool called the wikimap that can be used to search through all of the resources on the site. Astronomy: State of the Art (ASOTA) is a massive, open, online course (MOOC). Over 18,000 students have enrolled over the past year and half. This MOOC has been presented in various forms. First, only to students on the web, with content released weekly on host site Udemy. Then to university students who met formally in the classroom for educational activities, but were also expected to watch lectures online on their own time. Presently, it is available online for students to go at their own pace. In the future it will be available in an extended format on a new host site, Coursera. ASOTA instructors use social media to interact with students. Students ask questions via the course host site, Udemy. Live question and answer sessions are conducted using Google Hangouts on Air, and interesting and relevant astronomy news, or supplementary educational content is shared via the ASOTA Facebook page. Teaching on the Internet may seem impersonal and impractical, but by learning to use all of these tools, instructors have the ability to interact with students, and keep them engaged.

  7. The Astronomy of Africa’s Health Systems Literature During the MDG Era: Where Are the Systems Clusters? (United States)

    Sheff, Mallory; Boyer, Christopher B


    Growing international concern about the need for improved health systems in Africa has catalyzed an expansion of the health systems literature. This review applies a bibliometric procedure to analyze the acceleration of scientific writing on this theme. We focus on research published during the Millennium Development Goal (MDG) era between 1990 and 2014, reporting findings from a systematic review of a database comprised of 17,655 articles about health systems themes from sub-Saharan African countries or subregions. Using bibliometric tools for co-word textual analysis, we analyzed the incidence and associations of keywords and phrases to generate and visualize topical foci on health systems as clusters of themes, much in the manner that astronomers represent groupings of stars as galaxies of celestial entities. The association of keywords defines their relative position, with the size of images weighted by the relative frequency of terms. Sets of associated keywords are arrayed as stars that cluster as “galaxies” of concepts in the knowledge universe represented by health systems research from sub-Saharan Africa. Results show that health systems research is dominated by literature on diseases and categorical systems research topics, rather than on systems science that cuts across diseases or specific systemic themes. Systems research is highly developed in South Africa but relatively uncommon elsewhere in the region. “Black holes” are identified by searching for terms in our keyword library related to terms in widely cited reviews of health systems. Results identify several themes that are unexpectedly uncommon in the country-specific health systems literature. This includes research on the processes of achieving systems change, the health impact of systems strengthening, processes that explain the systems determinants of health outcomes, or systematic study of organizational dysfunction and ways to improve system performance. Research quantifying the

  8. The Radio JOVE Project - Shoestring Radio Astronomy (United States)

    Thieman, J.; Flagg, R.; Greenman, W.; Higgins, C.; Reyes, F.; Sky, J.


    Radio JOVE is an education and outreach project intended to give students and other interested individuals hands-on experience in learning radio astronomy. They can do this through building a radio telescope from a relatively inexpensive kit that includes the parts for a receiver and an antenna as well as software for a computer chart recorder emulator (Radio Skypipe) and other reference materials

  9. Interference mitigation for simultaneous transmit and receive applications on digital phased array systems (United States)

    Snow, Trevor M.

    As analog-to-digital (ADC) and digital-to-analog conversion (DAC) technologies become cheaper and digital processing capabilities improve, phased array systems with digital transceivers at every element will become more commonplace. These architectures offer greater capability over traditional analog systems and enable advanced applications such as multiple-input, multiple-output (MIMO) communications, adaptive beamforming, space-time adaptive processing (STAP), and MIMO for radar. Capabilities for such systems are still limited by the need for isolating self-interference from transmitters at co-located receivers. The typical approach of time-sharing the antenna aperture between transmitters and receivers works but leaves the receivers blind for a period of time. For full-duplex operation, some systems use separate frequency bands for transmission and reception, but these require fixed filtering which reduces the system's ability to adapt to its environment and is also an inefficient use of spectral resources. To that end, tunable, high quality-factor filters are used for sub-band isolation and protect receivers while allowing open reception at other frequencies. For more flexibility, another emergent area of related research has focused on co-located spatial isolation using multiple antennas and direct injection of interference cancellation signals into receivers, which enables same-frequency full-duplex operation. With all these methods, self-interference must be reduced by an amount that prevents saturation of the ADC. Intermodulation products generated in the receiver in this process can potentially be problematic, as certain intermodulation products may appear to come from a particular angle and cohere in the beamformer. This work explores various digital phased array architectures and the how the flexibility afforded by an all-digital beamforming architecture, layered with other methods of isolation, can be used to reduce self-interference within the system

  10. Direct Heat-Flux Measurement System (MDF) for Solar central Receiver Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Ballestrin, J.


    A direct flux measurement system, MDF, has been designed, constructed and mounted on top of the SSPS-CRS tower at the Plataforma Solar de Almeria (PSA) in addition to an indirect flux measurement system based on a CCD camera. It's one of the main future objectives to compare systematically both measurements of the concentrated solar power, increasing in this way the confidence in the estimate of this quantity. Today everything is prepared to perform the direct flux measurement on the aperture of solar receivers: calorimeter array, data acquisition system and software. the geometry of the receiver determines the operation and analysis procedures to obtain the indecent power onto the defined area. The study of previous experiences with direct flux measurement systems ha been useful to define a new simpler and more accurate system. A description of each component of the MDF system is included, focusing on the heat-flux sensors or calorimeters, which enables these measurements to be done in a few seconds without water-cooling. The incident solar power and the spatial flux distribution on the aperture of the volumetric receiver Hitrec II are supplied by the above-mentioned MDF system. The first results obtained during the evaluation of this solar receiver are presented including a sunrise-sunset test. All these measurements have been concentrated in one coefficient that describes the global behavior of the Solar Power Plant. (Author) 18 refs.

  11. Discovering Astronomy Through Poetry (United States)

    Mannone, John C.


    The literature is replete with astronomical references. And much of that literature is poetry. Using this fact, not only can the teacher infuse a new appreciation of astronomy, but also, the student has the opportunity to rediscover history through astronomy. Poetry can be an effective icebreaker in the introduction of new topics in physics and astronomy, as well as a point of conclusion to a lecture. This presentation will give examples of these things from the ancient literature (sacred Hebraic texts), classical literature (Homer's Iliad and Odyssey), traditional poetry (Longfellow, Tennyson and Poe) and modern literature (Frost, Kooser, and others, including the contemporary work of this author).

  12. Astronomy and culture

    CERN Document Server

    Hetherington, Edith


    While astronomy is a burgeoning science, with tremendous increases in knowledge every year, it also has a tremendous past, one that has altered humanity's understanding of our place in the universe. The impact of astronomy on culture - whether through myths and stories, or through challenges to the intellectual status quo - is incalculable. This volume in the Greenwood Guides to the Universe series examines how human cultures, in all regions and time periods, have tried to make sense of the wonders of the universe. Astronomy and Culture shows students how people throughout time have struggled

  13. Dispelling superstitions in Nepalese society with astronomy (United States)

    Shah, Rishi


    Throughout human history, astronomy has played crucial rôle in the development of our civilization, culture and daily chores of lives that have been influenced by observations of Sun, moon, planets, stars and other cosmic entities. Our ancestors who were hunting and gathering and foraging food while living in caves learned to think logically by gazing at the twinkling stars in the heavens. Seasons for crops plantation were determined, time concept was introduced, entire sky was charted and the motions of celestial objects were meaningfully understood. With the advent of telescopes, the geocentric model of universe was replaced by the revolutionary heliocentric concept of our Solar System. Astronomy dispelled superstitious beliefs strongly prevailing in societies. Closely associated with numerous disciplines of science astronomy is still flourishing worldwide and is attempting to fly us away to those habitable cosmic bodies of our universe. By establishing well-equipped observational infrastructure local and international astronomy research and development could be enhanced. Introduction of astronomy in education system right from school would attract and encourage students to pursue higher studies for enabling them for participating in future international scientific and exploration programmes. Astronomy has helped our society to progress peacefully and efficiently.

  14. Neural Network-Based Receiver in Band-Limited Communication System with MPPSK Modulation

    Directory of Open Access Journals (Sweden)

    Wang Zixin


    Full Text Available As a type of the spectrally efficient modulation, the m-ary phase position shift keying (MPPSK has been considered to meet the increasing spectrum requirement in the future wireless system. To limit the signal bandwidth and cancel the out-band interference the band-pass filters are used, which introduce the waveform distortion and inter-symbol interference (ISI. Therefore, a single hidden-layer neural network (NN-based receiver is proposed to jointly equalize and demodulate the received signal. The impulse response of the system is static and the network parameters can be obtained after off-line training. The number of the hidden nodes is also determined through simulations. Simulation results show that the NN-based receiver works well in the communication system with different allocated bandwidths. By observing the modified confusion matrix, the false symbol decision is relevant to modulation index, waveform distortions and the ISI.

  15. A novel mirror diversity receiver for indoor MIMO visible light communication systems

    KAUST Repository

    Park, Kihong


    In this paper, we propose and study a non-imaging receiver design reducing the correlation of channel matrix for indoor multiple-input multiple-output (MIMO) visible light communication (VLC) systems. Contrary to previous works, our proposed mirror diversity receiver (MDR) not only blocks the reception of light on one specific direction but also improves the channel gain on the other direction by receiving the light reflected by a mirror deployed between the photodetectors. We analyze the channel capacity and optimal height of mirror in terms of maximum channel capacity for a 2 × 2 MIMO-VLC system in a 2-dimensional geometric model. We prove that this constructive and destructive effects in channel matrix resulting from our proposed MDR are more beneficial to obtain well-conditioned channel matrix which is suitable for implementing spatial-multiplexing MIMO-VLC systems in order to support high data rate.

  16. Analysis of optical amplifier noise in coherent optical communication systems with optical image rejection receivers

    DEFF Research Database (Denmark)

    Jørgensen, Bo Foged; Mikkelsen, Benny; Mahon, Cathal J.


    A detailed theoretical analysis of optical amplifier noise in coherent optical communication systems with heterodyne receivers is presented. The analysis quantifies in particular how optical image rejection receiver configurations reduce the influence of optical amplifier noise on system performa......A detailed theoretical analysis of optical amplifier noise in coherent optical communication systems with heterodyne receivers is presented. The analysis quantifies in particular how optical image rejection receiver configurations reduce the influence of optical amplifier noise on system...... performance. Two types of optical image rejection receivers are investigated: a novel, all-optical configuration and the conventional, microwave-based configuration. The analysis shows that local oscillator-spontaneous emission beat noise (LO-SP), signal-spontaneous emission beat noise (S-SP), and spontaneous......-spontaneous beat noise (SP-SP) can all be reduced by 3 dB, thereby doubling the dynamic range of the optical amplifier. A 2.5-dB improvement in dynamic range has been demonstrated experimentally with the all-optical image rejection configuration. The implications of the increased dynamic range thus obtained...

  17. Enhancing Astronomy Major Learning Through Group Research Projects (United States)

    McGraw, Allison M.; Hardegree-Ullman, K.; Turner, J.; Shirley, Y. L.; Walker-Lafollette, A.; Scott, A.; Guvenen, B.; Raphael, B.; Sanford, B.; Smart, B.; Nguyen, C.; Jones, C.; Smith, C.; Cates, I.; Romine, J.; Cook, K.; Pearson, K.; Biddle, L.; Small, L.; Donnels, M.; Nieberding, M.; Kwon, M.; Thompson, R.; De La Rosa, R.; Hofmann, R.; Tombleson, R.; Smith, T.; Towner, A. P.; Wallace, S.


    The University of Arizona Astronomy Club has been using group research projects to enhance the learning experience of undergraduates in astronomy and related fields. Students work on two projects that employ a peer-mentoring system so they can learn crucial skills and concepts necessary in research environments. Students work on a transiting exoplanet project using the 1.55-meter Kuiper Telescope on Mt. Bigelow in Southern Arizona to collect near-UV and optical wavelength data. The goal of the project is to refine planetary parameters and to attempt to detect exoplanet magnetic fields by searching for near-UV light curve asymmetries. The other project is a survey that utilizes the 12-meter Arizona Radio Observatory on Kitt Peak to search for the spectroscopic signature of infall in nearby starless cores. These are unique projects because students are involved throughout the entire research process, including writing proposals for telescope time, observing at the telescopes, data reduction and analysis, writing papers for publication in journals, and presenting research at scientific conferences. Exoplanet project members are able to receive independent study credit for participating in the research, which helps keep the project on track. Both projects allow students to work on professional research and prepare for several astronomy courses early in their academic career. They also encourage teamwork and mentor-style peer teaching, and can help students identify their own research projects as they expand their knowledge.

  18. Efficient Compensation of Transmitter and Receiver IQ Imbalance in OFDM Systems

    Directory of Open Access Journals (Sweden)

    Tandur Deepaknath


    Full Text Available Radio frequency impairments such as in-phase/quadrature-phase (IQ imbalances can result in a severe performance degradation in direct-conversion architecture-based communication systems. In this paper, we consider the case of transmitter and receiver IQ imbalance together with frequency selective channel distortion. The proposed training-based schemes can decouple the compensation of transmitter and receiver IQ imbalance from the compensation of channel distortion in an orthogonal frequency division multiplexing (OFDM systems. The presence of frequency selective channel fading is a requirement for the estimation of IQ imbalance parameters when both transmitter/receiver IQ imbalance are present. However, the proposed schemes are equally applicable over a frequency flat/frequency selective channel when either transmitter or only receiver IQ imbalance is present. Once the transmitter and receiver IQ imbalance parameters are estimated, a standard channel equalizer can be applied to estimate/compensate for the channel distortion. The proposed schemes result in an overall lower training overhead and a lower computational requirement, compared to the joint compensation of transmitter/receiver IQ imbalance and channel distortion. Simulation results demonstrate that the proposed schemes provide a very efficient compensation with performance close to the ideal case without any IQ imbalance.

  19. Galactic radio astronomy

    CERN Document Server

    Sofue, Yoshiaki


    This book is a concise primer on galactic radio astronomy for undergraduate and graduate students, and provides wide coverage of galactic astronomy and astrophysics such as the physics of interstellar matter and the dynamics and structure of the Milky Way Galaxy and galaxies. Radio astronomy and its technological development have led to significant progress in galactic astronomy and contributed to understanding interstellar matter and galactic structures. The book begins with the fundamental physics of radio-wave radiation, i.e., black body radiation, thermal emission, synchrotron radiation, and HI and molecular line emissions. The author then gives overviews of ingredients of galactic physics, including interstellar matter such as the neutral (HI), molecular hydrogen, and ionized gases, as well as magnetic fields in galaxies. In addition, more advanced topics relevant to the Galaxy and galaxies are also contained here: star formation, supernova remnants, the Galactic Center and black holes, galactic dynamics...

  20. Cultural Astronomy in Japan (United States)

    Renshaw, Steven L.

    While Japan is known more for its contributions to modern astronomy than its archaeoastronomical sites, there is still much about the culture's heritage that is of interest in the study of cultural astronomy. This case study provides an overview of historical considerations necessary to understand the place of astronomy in Japanese society as well as methodological considerations that highlight traditional approaches that have at times been a barrier to interdisciplinary research. Some specific areas of study in the cultural astronomy of Japan are discussed including examples of contemporary research based on interdisciplinary approaches. Japan provides a fascinating background for scholars who are willing to go beyond their curiosity for sites of alignment and approach the culture with a desire to place astronomical iconography in social context.

  1. Stamping through astronomy

    CERN Document Server

    Dicati, Renato


    Stamps and other postal documents are an attractive vehicle for presenting astronomy and its development. Written with expertise and great enthusiasm, this unique book offers a historical and philatelic survey of astronomy and some related topics on space exploration. It contains more than 1300 color reproductions of stamps relating to the history of astronomy, ranging from the earliest observations of the sky to modern research conducted with satellites and space probes. Featured are the astronomers and astrophysicists who contributed to this marvelous story – not only Ptolemy, Copernicus, Kepler, Newton, Herschel, and Einstein but also hundreds of other minor protagonists who played an important role in the development of this, the most ancient yet the most modern of all the sciences. The book also examines in depth the diverse areas which have contributed to the history of astronomy, including the instrumentation, the theories, and the observations. Many stamps illustrate the beauty and the mystery of ce...

  2. Astronomy, Astrology, and Medicine (United States)

    Greenbaum, Dorian Gieseler

    Astronomy and astrology were combined with medicine for thousands of years. Beginning in Mesopotamia in the second millennium BCE and continuing into the eighteenth century, medical practitioners used astronomy/astrology as an important part of diagnosis and prescription. Throughout this time frame, scientists cited the similarities between medicine and astrology, in addition to combining the two in practice. Hippocrates and Galen based medical theories on the relationship between heavenly bodies and human bodies. In an enduring cultural phenomenon, parts of the body as well as diseases were linked to zodiac signs and planets. In Renaissance universities, astronomy and astrology were studied by students of medicine. History records a long tradition of astrologer-physicians. This chapter covers the topic of astronomy, astrology, and medicine from the Old Babylonian period to the Enlightenment.

  3. Combined cycle solar central receiver hybrid power system study. Final technical report. Volume II

    Energy Technology Data Exchange (ETDEWEB)



    This study develops the conceptual design for a commercial-scale (nominal 100 MWe) central receiver solar/fossil fuel hybrid power system with combined cycle energy conversion. A near-term, metallic heat pipe receiver and an advanced ceramic tube receiver hybrid system are defined through parametric and market potential analyses. Comparative evaluations of the cost of power generation, the fuel displacement potential, and the technological readiness of these two systems indicate that the near-term hybrid system has better potential for commercialization by 1990. Based on the assessment of the conceptual design, major cost and performance improvements are projected for the near-term system. Constraints preventing wide-spread use were not identified. Energy storage is not required for this system and analyses show no economic advantages with energy storage provisions. It is concluded that the solar hybrid system is a cost effective alternative to conventional gas turbines and combined cycle generating plants, and has potential for intermediate-load market penetration at 15% annual fuel escalation rate. Due to their flexibility, simple solar/nonsolar interfacing, and short startup cycles, these hybrid plants have significant operating advantages. Utility company comments suggest that hybrid power systems will precede stand-alone solar plants.

  4. Astronomy in Mexico (United States)

    Lee, William H.


    Mexican astronomy has a long standing tradition of excellence in research. After a brief review of its history, I outline the current profile of the community, the available infrastructure and participating institutions, and give a glimpse into the future through current projects. The development of astronomy can serve as a powerful lever for science, technological development, education and outreach, as well as for improving the much needed link between basic research and industry development.

  5. Astronomy in Second Life

    Directory of Open Access Journals (Sweden)

    Gauthier, A.


    Full Text Available Second Life (SL is a multi-user virtual environment that is not limited to adult social entertainment. SL is also a 3D playground for innovative instructors and education/outreach professionals in the sciences. Astronomy and space science have a presence in SL, but it could be so much more. This paper describes some of the current astronomy themed spaces in SL and briefly discusses future innovations.

  6. Music and Astronomy (United States)

    Caballero, José A.; González Sánchez, S.; Caballero, I.

    What do Brian May (Queen's lead guitarist), William Herschel and the Jupiter Symphony have in common? And a white dwarf, a piano and Lagartija Nick? At first glance, there is no connection between them, nor between the Music and the Astronomy. However, there are many revealing examples of musical Astronomy and astronomical Music. This four-page proceeding describes the sonorous poster that we showed during the VIII Scientific Meeting of the Spanish Astronomical Society.

  7. NASA thesaurus: Astronomy vocabulary (United States)

    A terminology of descriptors used by the NASA Scientific and Technical information effort to index documents in the area of astronomy is presented. The terms are listed in hierarchical format derived from the 1988 edition of the NASA Thesaurus Volume 1 -- Hierarchical Listing. Over 1600 terms are included. In addition to astronomy, space sciences covered include astrophysics, cosmology, lunar flight and exploration, meteors and meteorites, celestial mechanics, planetary flight and exploration, and planetary science.

  8. Massive Datasets in Astronomy


    Brunner, Robert J.; Djorgovski, S. George; Prince, Thomas A.; Szalay, Alex S.


    Astronomy has a long history of acquiring, systematizing, and interpreting large quantities of data. Starting from the earliest sky atlases through the first major photographic sky surveys of the 20th century, this tradition is continuing today, and at an ever increasing rate. Like many other fields, astronomy has become a very data-rich science, driven by the advances in telescope, detector, and computer technology. Numerous large digital sky surveys and archives already exist, with informat...

  9. Message-Passing Receiver for OFDM Systems over Highly Delay-Dispersive Channels

    DEFF Research Database (Denmark)

    Barbu, Oana-Elena; Manchón, Carles Navarro; Rom, Christian


    Propagation channels with maximum excess delay exceeding the duration of the cyclic prefix (CP) in OFDM systems cause intercarrier and intersymbol interference which, unless accounted for, degrade the receiver performance. Using tools from Bayesian inference and sparse signal reconstruction, we...... derive an iterative algorithm that estimates an approximate representation of the channel impulse response and the noise variance, estimates and cancels the intrinsic interference and decodes the data over a block of symbols. Simulation results show that the receiver employing our algorithm outperforms...... and future wireless communications systems. By enabling the OFDM receiver experiencing these harsh conditions to locally cancel the interference, our design circumvents the spectral efficiency loss incurred by extending the CP duration, otherwise a straightforward solution. Furthermore, it sets the premises...

  10. Optimal Analytical Solution for a Capacitive Wireless Power Transfer System with One Transmitter and Two Receivers

    Directory of Open Access Journals (Sweden)

    Ben Minnaert


    Full Text Available Wireless power transfer from one transmitter to multiple receivers through inductive coupling is slowly entering the market. However, for certain applications, capacitive wireless power transfer (CWPT using electric coupling might be preferable. In this work, we determine closed-form expressions for a CWPT system with one transmitter and two receivers. We determine the optimal solution for two design requirements: (i maximum power transfer, and (ii maximum system efficiency. We derive the optimal loads and provide the analytical expressions for the efficiency and power. We show that the optimal load conductances for the maximum power configuration are always larger than for the maximum efficiency configuration. Furthermore, it is demonstrated that if the receivers are coupled, this can be compensated for by introducing susceptances that have the same value for both configurations. Finally, we numerically verify our results. We illustrate the similarities to the inductive wireless power transfer (IWPT solution and find that the same, but dual, expressions apply.

  11. Performance and Complexity Evaluation of Iterative Receiver for Coded MIMO-OFDM Systems

    Directory of Open Access Journals (Sweden)

    Rida El Chall


    Full Text Available Multiple-input multiple-output (MIMO technology in combination with channel coding technique is a promising solution for reliable high data rate transmission in future wireless communication systems. However, these technologies pose significant challenges for the design of an iterative receiver. In this paper, an efficient receiver combining soft-input soft-output (SISO detection based on low-complexity K-Best (LC-K-Best decoder with various forward error correction codes, namely, LTE turbo decoder and LDPC decoder, is investigated. We first investigate the convergence behaviors of the iterative MIMO receivers to determine the required inner and outer iterations. Consequently, the performance of LC-K-Best based receiver is evaluated in various LTE channel environments and compared with other MIMO detection schemes. Moreover, the computational complexity of the iterative receiver with different channel coding techniques is evaluated and compared with different modulation orders and coding rates. Simulation results show that LC-K-Best based receiver achieves satisfactory performance-complexity trade-offs.

  12. Teaching Astronomy with Podcasts of the APOD (United States)

    Wagner, Robert M.


    The APOD website provides many excellent astronomy photos that are used to enhance introductory astronomy classes. For nearly six years, podcasts have been used to enhance learning in introductory astronomy classes at Harrisburg Area Community College. Daily 3-5 minute podcasts have been created and made available through iTunes to students in these classes at no charge. Students are asked to subscribe to the podcast collections and are quizzed on the images discussed throughout the semester. Because the images often focus on current findings in astronomy, the students are given instruction on findings that will not appear in their textbooks for several years. The students also receive a taste of some topics that may not be covered or that are just touched upon because of time limits in the classes. The podcasts have been used successfully with both traditional and fully online classes. The use of the podcasts enhances mobile learning as students can download and listen to the podcasts on their smartphones or tablets at their convenience. The student response to the podcasts has been excellent with some students noting that they continue to follow the website and podcasts even after they have completed the class. With mobile learning expanding, this is an excellent way to reach students and encourage them to further research the various topics in astronomy that are covered in the APOD images.

  13. System-Level Design of an Integrated Receiver Front End for a Wireless Ultrasound Probe

    DEFF Research Database (Denmark)

    di Ianni, Tommaso; Hemmsen, Martin Christian; Llimos Muntal, Pere


    In this paper, a system-level design is presented for an integrated receive circuit for a wireless ultrasound probe, which includes analog front ends and beamformation modules. This paper focuses on the investigation of the effects of architectural design choices on the image quality. The point s...

  14. Message-Passing Receivers for Single Carrier Systems with Frequency-Domain Equalization

    DEFF Research Database (Denmark)

    Zhang, Chuanzong; Manchón, Carles Navarro; Wang, Zhongyong


    In this letter, we design iterative receiver algorithms for joint frequency-domain equalization and decoding in a single carrier system assuming perfect channel state information. Based on an approximate inference framework that combines belief propagation (BP) and the mean field (MF) approximati...

  15. Anterior cruciate ligament reconstruction in a patient who has received systemic steroids for autoimmune disease

    Directory of Open Access Journals (Sweden)

    Tetsuro Ushio


    Conclusion: The patient who had received systemic steroids for a long time recovered satisfactorily after the operation, with achievement of knee stability and possibility to prevent degenerative change in the knee joint. ACL reconstruction should be considered even in patients with such medication.

  16. Simulation of a ring resonator-based optical beamformer system for phased array receive antennas

    NARCIS (Netherlands)

    Tijmes, M.R.; Meijerink, Arjan; Roeloffzen, C.G.H.; Bentum, Marinus Jan


    A new simulator tool is described that can be used in the field of RF photonics. It has been developed on the basis of a broadband, continuously tunable optical beamformer system for phased array receive antennas. The application that is considered in this paper is airborne satellite reception of

  17. Optimization of an Angle-Aided Mirror Diversity Receiver for Indoor MIMO-VLC Systems

    KAUST Repository

    Park, Kihong


    In this paper, we investigate the channel correlation problem which affects the performance of indoor multiple-input multiple-output (MIMO) visible light communication (VLC) systems. More specifically, in order to reduce the high correlation of channel matrix in MIMO-VLC intensity channel, we propose a non-imaging receiver called angle-aided mirror diversity receiver (AMDR) which utilizes not only a mirror placement but also a variation of orientation angle for the photodetector (PD) plane. Deploying a mirror helps reducing the correlation by blocking the reception of the light in one specific direction and by receiving additional light reflected in the mirror in another direction, while orienting the angle of PD plane into specific direction enables the directional reception of light. Applying a zero-forcing decorrelator at the receiver, we analyze the bit error rate (BER) performance for a 2×2 multiplexing MIMO-VLC system using a 2-dimensional geometric model. In particular, we formulate a min-max BER problem and find the optimal height of mirror and elevation angle of PD plane. Some selected numerical results validate our proposed optimal solution to our min-max BER problem and show that the BER performance of our proposed AMDR outperforms that of the previous non-imaging receivers.

  18. Cultural Astronomy in Armenia and in the World (United States)

    Farmanyan, S. V.; Mickaelian, A. M.


    Cultural Astronomy is the reflection of sky events in various fields of nations' culture. In foreign literature, this field is also called "Astronomy in Culture" or "Astronomy and Culture". Cultural astronomy is the set of interdisciplinary fields studying the astronomical systems of current or ancient societies and cultures. It is manifested in Religion, Mythology, Folklore, Poetry, Art, Linguistics and other fields. In recent years, considerable attention has been paid to this sphere, particularly international organizations were established, conferences are held and journals are published. Armenia is also rich in cultural astronomy. The present paper focuses on Armenian archaeoastronomy and cultural astronomy, including many creations related to astronomical knowledge; calendars, rock art, mythology, etc. On the other hand, this subject is rather poorly developed in Armenia; there are only individual studies on various related issues (especially many studies related to Anania Shirakatsi) but not coordinated actions to manage this important field of investigation.

  19. Waste Receiving and Processing Facility Module 1 Data Management System Software Requirements Specification

    Energy Technology Data Exchange (ETDEWEB)

    Brann, E.C. II


    This document provides the software requirements for Waste Receiving and Processing (WRAP) Module 1 Data Management System (DMS). The DMS is one of the plant computer systems for the new WRAP 1 facility (Project W-026). The DMS will collect, store and report data required to certify the low level waste (LLW) and transuranic (TRU) waste items processed at WRAP 1 as acceptable for shipment, storage, or disposal.

  20. Waste Receiving and Processing Facility Module 1 Data Management System software requirements specification

    Energy Technology Data Exchange (ETDEWEB)

    Rosnick, C.K.


    This document provides the software requirements for Waste Receiving and Processing (WRAP) Module 1 Data Management System (DMS). The DMS is one of the plant computer systems for the new WRAP 1 facility (Project W-0126). The DMS will collect, store and report data required to certify the low level waste (LLW) and transuranic (TRU) waste items processed at WRAP 1 as acceptable for shipment, storage, or disposal.

  1. The history of astronomy a very short introduction

    CERN Document Server

    Hoskin, Michael


    The History of Astronomy: A Very Short Introduction traces the history of Western astronomy, from prehistoric times to the origins of astrophysics in the mid-nineteenth century and the technical developments since the Second World War. Astronomy, perhaps the first of the sciences, was already well developed by the time of Christ — the arithmetical astronomy of the Babylonians was merged with the Greek geometrical approach. This legacy was transmitted to the West via Islam and led to the Copernican revolution, which in turn led to Kepler and Newton, who provided the principles on which the exploration of the solar system and the stars continued in the eighteenth- and nineteenth centuries.

  2. High-temperature solar receiver integrated with a short-term storage system (United States)

    Giovannelli, Ambra; Bashir, Muhammad Anser; Archilei, Erika Maria


    Small-Scale Concentrated Solar Power Plants could have a potential market for off-grid applications in rural contexts with limited access to the electrical grid and favorable environmental characteristics. Some Small-Scale plants have already been developed, like the 25-30 kWe Dish-Stirling engine. Other ones are under development as, for example, plants based on Parabolic Trough Collectors coupled with Organic Rankine Cycles. Furthermore, the technological progress achieved in the development of new small high-temperature solar receiver, makes possible the development of interesting systems based on Micro Gas Turbines coupled with Dish collectors. Such systems could have several advantages in terms of costs, reliability and availability if compared with Dish-Stirling plants. In addition, Dish-Micro Gas Turbine systems are expected to have higher performance than Solar Organic Rankine Cycle plants. The present work focuses the attention on some challenging aspects related to the design of small high-temperature solar receivers for Dish-Micro Gas Turbine systems. Natural fluctuations in the solar radiation can reduce system performance and damage seriously the Micro Gas Turbine. To stabilize the system operation, the solar receiver has to assure a proper thermal inertia. Therefore, a solar receiver integrated with a short-term storage system based on high-temperature phase-change materials is proposed in this paper. Steady-state and transient analyses (for thermal storage charge and discharge phases) have been carried out using the commercial CFD code Ansys-Fluent. Results are presented and discussed.

  3. Astronomy from the chair - the application of the Internet in promoting of Astronomy (United States)

    Tomic, Zoran


    Internet and modern communication technologies are an indispensable part of modern life. The use of the Internet makes it possible to enhance the education and expand opportunities for acquiring new knowledge. One example is Astronomy, where today thanks to the Internet, we can control telescopes that are distant from us and listen to lectures from Universities in other countries. "Astronomy from the chair" is the name for a concept where amateur astronomers can deal with astronomy from their homes using the Internet. The concept can be divided into four sections depending on the content being offered: Robotic Observatory, Virtual Observatory, Online astronomy broadcasting and Online courses. Robotic observatory is defined as an astronomical instrument and detection system that enables efficient observation without the need of a person's physical intervention. Virtual Observatory is defined as a collection of databases and software tools that use the Internet as a platform for scientific research. Online astronomy broadcasting is part of concept "Astronomy from the chair" which gives users the opportunity to get directly involved in astronomical observation organized by an amateur astronomer from somewhere in the world. Online courses are groups of sites and organizations that provide the opportunity to amateur astronomers to attend lectures, save and watch video materials from lectures, do homework, communicate with other seminar participants and in that way become familiar with the various areas of Astronomy. This paper discusses a new concept that describes how the Internet can be applied in modern education. In this paper will be described projects that allows a large number of astronomy lovers to do their own research without the need to own a large and expensive set of astronomical equipment (Virtual Telescope from Italy, Observatory "Night Hawk" from Serbia and project "Astronomy from an armchair" at Faculty of Sciences and Mathematics in Nis), to help

  4. Radio Wavelength Studies of the Galactic Center Source N3, Spectroscopic Instrumentation For Robotic Telescope Systems, and Developing Active Learning Activities for Astronomy Laboratory Courses (United States)

    Ludovici, Dominic Alesio


    The mysterious radio source N3 appears to be located within the vicinity of the Radio Arc region of the Galactic Center. To investigate the nature of this source, we have conducted radio observations with the VLA and the VLBA. Continuum observations between 2 and 50 GHz reveal that N3 is an extremely compact and bright source with a non-thermal spectrum. Molecular line observations with the VLA reveal a compact molecular cloud adjacent to N3 in projection. The properties of this cloud are consistent with other galactic center clouds. We are able to rule out several hypotheses for the nature of N3, though a micro-blazar origin cannot be ruled out. Robotic Telescope systems are now seeing widespread deployment as both teaching and research instruments. While these systems have traditionally been able to produce high quality images, these systems have lacked the capability to conduct spectroscopic observations. To enable spectroscopic observations on the Iowa Robotic Observatory, we have developed a low cost (˜ 500), low resolution (R ˜ 300) spectrometer which mounts inside a modified filter wheel and a moderate cost (˜ 5000), medium resolution (R ˜ 8000) fiber-fed spectrometer. Software has been developed to operate both instruments robotically and calibration pipelines are being developed to automate calibration of the data. The University of Iowa offers several introductory astronomy laboratory courses taken by many hundreds of students each semester. To improve student learning in these laboratory courses, we have worked to integrate active learning into laboratory activities. We present the pedagogical approaches used to develop and update the laboratory activities and present an inventory of the current laboratory exercises. Using the inventory, we make observations of the strengths and weaknesses of the current exercises and provide suggestions for future refinement of the astronomy laboratory curriculum.

  5. A Pedestrian Dead Reckoning System Integrating Low-Cost MEMS Inertial Sensors and GPS Receiver

    Directory of Open Access Journals (Sweden)

    Jin-feng Li


    Full Text Available The body-mounted inertial systems for pedestrian navigation do not require any preinstalled facilities and can run autonomously. The advantages over other technologies make it especially attractive for the applications such as first responders, military and consumer markets. The hardware platform integrating the low-cost, low-power and small-size MEMS (micro-electro-mechanical systems inertial sensors and GPS (global positioning system receiver is proposed. When the satellite signals are available, the location of the pedestrian is directly obtained from the GPS receiver. The inertial sensors are the complement of the GPS receiver in places where the GPS signals are not available, such as indoors, urban canyons and places under dense foliages. The height tracking is achieved by the barometer. The proposed PDR (pedestrian dead reckoning algorithm is real-timely implemented in the platform. The simple but effective step detection and step length estimation method are realized to reduce the computation and memory requirements on the microprocessor. A complementary filter is proposed to fuse the data from the accelerometer, gyroscope and digital compass for decreasing the heading error, which is the main error source in positioning. The reliability and accuracy of the proposed system is verified by field pedestrian walking tests in outdoors and indoors. The positioning error is less than 4% of the total traveled distance. The results indicate that the pedestrian dead reckoning system is able to provide satisfactory tracking performance.

  6. An appeals system for fines received by adolescents in a token economy. (United States)

    Miller, R P; Cosgrove, J M


    A system is described wherein adolescents participating in a token economy at a state hospital were allowed to appeal fines received from staff. Appeals were heard by a board composed of three residents and a psychology intern. The board met weekly and had full power to rescind or uphold fines. Before initiation of the appeal system, residents complained vigorously about fines received and about the "unfairness" of the staff and the token system, frequently denying responsibility for the infractions involved. Although almost half the fines were upheld, there were practically no more complaints of unfairness, and denials of responsibility declined drastically. The number of residents appealing fines fell from an average of four per week to less than one per week after the system had been in effect for one and one-half months. When asked why the system was not being used more often, residents grudgingly volunteered that most of the fines received were fair. It was not possible to determine whether this was due to changes in residents' attitudes or to actual changes in fining behavior by staff. Results are discussed in terms of effects on residents, acceptance by staff, and implications for further research.

  7. BER analysis of IM/DD FSO system with APD receiver over gamma-gamma turbulence

    Directory of Open Access Journals (Sweden)

    Petković Milica I.


    Full Text Available In this paper, the bit-error rate (BER performance of intensity modulated with direct detection (IM/DD free space optical (FSO system using the on-off keying (OOK and avalanche photodiode (APD receiver is analyzed. The intensity fluctuations of the received optical signal are modeled by gamma gamma distribution, while both zero and nonzero inner scale models are observed. The total receiver noise includes APD shot noise and thermal noise. The BER expression is theoretically derived and numerical results are presented. The results illustrate the BER dependence on the turbulence strength, propagation path length, APD gain and noise temperature. [Projekat Ministarstva nauke Republike Srbije, br. TR-32028 i br. III-44006

  8. Three-phase receiving coil of wireless power transmission system for gastrointestinal robot (United States)

    Jia, Z. W.; Jiang, T.; Liu, Y.


    Power shortage is the bottleneck for the wide application of gastrointestinal (GI) robot. Owing to the limited volume and free change of orientation of the receiving set in GI trace, the optimal of receiving set is the key point to promote the transmission efficiency of wireless power transmission system. A new type of receiving set, similar to the winding of three-phase asynchronous motor, is presented and compared with the original three-dimensional orthogonal coil. Considering the given volume and the space utilization ratio, the three-phase and the three-orthogonal ones are the parameters which are optimized and compared. Both the transmission efficiency and stability are analyzed and verified by in vitro experiments. Animal experiments show that the new one could provide at least 420 mW power in volume of Φ11 × 13mm with a uniformity of 78.3% for the GI robot.

  9. Gnuastro: GNU Astronomy Utilities (United States)

    Akhlaghi, Mohammad


    Gnuastro (GNU Astronomy Utilities) manipulates and analyzes astronomical data. It is an official GNU package of a large collection of programs and C/C++ library functions. Command-line programs perform arithmetic operations on images, convert FITS images to common types like JPG or PDF, convolve an image with a given kernel or matching of kernels, perform cosmological calculations, crop parts of large images (possibly in multiple files), manipulate FITS extensions and keywords, and perform statistical operations. In addition, it contains programs to make catalogs from detection maps, add noise, make mock profiles with a variety of radial functions using monte-carlo integration for their centers, match catalogs, and detect objects in an image among many other operations. The command-line programs share the same basic command-line user interface for the comfort of both the users and developers. Gnuastro is written to comply fully with the GNU coding standards and integrates well with all Unix-like operating systems. This enables astronomers to expect a fully familiar experience in the source code, building, installing and command-line user interaction that they have seen in all the other GNU software that they use. Gnuastro's extensive library is included for users who want to build their own unique programs.

  10. Thermal Analysis of Direct Liquid-Immersed Solar Receiver for High Concentrating Photovoltaic System

    Directory of Open Access Journals (Sweden)

    Xinyue Han


    Full Text Available Concentrator solar cells that operate at high solar concentration level must be cooled. In this paper, direct liquid immersion cooling of triple-junction solar cells (InGaP/InGaAs/Ge is proposed as a heat dissipation solution for dense-array high concentrating photovoltaic (HCPV systems. The advantages of triple-junction CPV cells immersed in a circulating dielectric liquid and dish HCPV technology are integrated into a CPV system to improve the system electrical conversion efficiency. An analytical model for the direct liquid-immersed solar receiver with triple-junction CPV cells is presented. The main outputs of the model are the components temperatures of the receiver and the system electrical efficiency. The influence of concentration factor, mass flow rate, and inlet liquid temperature on the operating temperature of the triple-junction CPV cells and the system electrical conversion efficiency are discussed. It is shown that the system electrical conversion efficiency is very high for a wide range of operating conditions. The three operating parameters have a major effect on the operating temperature of the triple-junction CPV cells and, by extension, system output power. The flow rate selection should match concentration factor to keep the triple-junction CPV cells temperature lower and increase the electrical conversion efficiency of the dense-array HCPV system.

  11. The testing techniques of the automatics fire detection monitoring systems (A receiver and A transmitter)

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Yon Woo; Soong, Woong Sup; Kim, Kee Ha [Korea Atomic Energy Research Institute, Taejon (Korea)


    The major function of the automatic fire detection system is to use effectively the fire-fighting equipments and the shelter apparatus detecting immediately the fire and notifying the fire to a person in charge. To perform these functions, the automatic fire detection system is composed of a receiver and a transmitter which indicate the origin of a fire, sound facility, wiring and power supply. And the main purpose using this system is to stop the spread of the fire and minimize the damage of human life and properties of the facility. 12 refs., 17 figs., 11 tabs. (Author)

  12. Visible Light Communication System Using Silicon Photocell for Energy Gathering and Data Receiving

    Directory of Open Access Journals (Sweden)

    Xiongbin Chen


    Full Text Available Silicon photocell acts as the detector and energy convertor in the VLC system. The system model was set up and simulated in Matlab/Simulink environment. A 10 Hz square wave was modulated on LED and restored in voltage mode at the receiver. An energy gathering and signal detecting system was demonstrated at the baud rate of 19200, and the DC signal is about 2.77 V and AC signal is around 410 mV.

  13. A Coherent Optical OFDM Communication System with Nonlinear Distortion Compensation in the Channel and Receiver (United States)

    Asha, R. S.; Jayasree, V. K.


    A simple and low-cost scheme is proposed for reducing the distortions in the coherent optical orthogonal frequency-division multiplexing (CO-OFDM) system. The total wireless channel noise and the distortions in the receiver can be considered as an additive white Gaussian noise model and all distortions can be reduced using maximum likelihood sequence estimation (MLSE) equalizers. The performance of the CO-OFDM is analyzed for different fiber lengths and laser powers. Results show that the MLSE-equalized system can outperform with a higher Q-factor of 8 dB than conventional CO-OFDM system.

  14. Thermal properties of high temperature vacuum receivers used for parabolic trough solar thermal power system

    Directory of Open Access Journals (Sweden)

    Qinghe Yu


    Full Text Available The receiver's emittance and vacuum pressure are the two of great significance issues on the heat-loss which is the main factor reducing the efficiency of the parabolic though systems. In this paper, the thermal steady-state equilibrium method was used to test the receivers’ heat-loss. The receivers with increasing emittance were tested to study the variation of heat-loss. Meanwhile, the variable vacuum pressure in the annulus that affects the efficiency of the system was investigated. The influence of vacuumizing rate and getters on the vacuum pressure and heat-loss were discussed. The result shows that the emittance and vacuum pressure affect the receiver's heat-loss dramatically, and the emittance is the major influence factor on the thermal properties. The receiver with 0.08 emittance and 10−3 Pa vacuum pressure has a satisfactory heat-loss of 215.6 W/m at 400 °C. The analysis further reveals that the synergistic effect of both emittance and vacuum pressure on the heat-loss can be reflected by the packaging temperature of the glass tube, and a fitting formula has been established to estimate the receivers’ heat-loss according to the packaging temperature of the glass tube.

  15. Metal Mesh Filters for Terahertz Receivers Project (United States)

    National Aeronautics and Space Administration — The technical objective of this SBIR program is to develop and demonstrate metal mesh filters for use in NASA's low noise receivers for terahertz astronomy and...

  16. FPGA-Based Communications Receivers for Smart Antenna Array Embedded Systems

    Directory of Open Access Journals (Sweden)

    James Millar


    Full Text Available Field-programmable gate arrays (FPGAs are drawing ever increasing interest from designers of embedded wireless communications systems. They outpace digital signal processors (DSPs, through hardware execution of a wide range of parallelizable communications transceiver algorithms, at a fraction of the design and implementation effort and cost required for application-specific integrated circuits (ASICs. In our study, we employ an Altera Stratix FPGA development board, along with the DSP Builder software tool which acts as a high-level interface to the powerful Quartus II environment. We compare single- and multibranch FPGA-based receiver designs in terms of error rate performance and power consumption. We exploit FPGA operational flexibility and algorithm parallelism to design eigenmode-monitoring receivers that can adapt to variations in wireless channel statistics, for high-performing, inexpensive, smart antenna array embedded systems.

  17. Receiver IQ mismatch estimation in PDM CO-OFDM system using training symbol (United States)

    Peng, Dandan; Ma, Xiurong; Yao, Xin; Zhang, Haoyuan


    Receiver in-phase/quadrature (IQ) mismatch is hard to mitigate at the receiver via using conventional method in polarization division multiplexed (PDM) coherent optical orthogonal frequency division multiplexing (CO-OFDM) system. In this paper, a novel training symbol structure is proposed to estimate IQ mismatch and channel distortion. Combined this structure with Gram Schmidt orthogonalization procedure (GSOP) algorithm, we can get lower bit error rate (BER). Meanwhile, based on this structure one estimation method is deduced in frequency domain which can achieve the estimation of IQ mismatch and channel distortion independently and improve the system performance obviously. Numerical simulation shows that the proposed two methods have better performance than compared method at 100 Gb/s after 480 km fiber transmission. Besides, the calculation complexity is also analyzed.

  18. Optimal System Frequency Response Model and UFLS Schemes for a Small Receiving-End Power System after Islanding

    Directory of Open Access Journals (Sweden)

    Deyou Yang


    Full Text Available Large frequency deviations after islanding are exceedingly critical in small receiving-end power systems. The under-frequency load shedding (UFLS scheme is an efficient protection step for preventing system black outs. It is very important to get an exact model to design the UFLS schemes. In this paper, an optimization model to achieve the system frequency response (SFR model either from the full-scale power system or from test records was proposed. The optimized SFR model took into account the response of governors-prime movers and the dynamic characteristics of loads developed in the modern power system. Then the UFLS schemes were designed via the optimized SFR model and particle swarm optimization (PSO method. The time-domain simulation with the actual small receiving-end power system was presented to investigate the validity of the presented model and the developed technique.

  19. Astronomy in the Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Palouš, Jan; Hadrava, Petr

    -, č. 128 (2007), s. 3-3 ISSN 0722-6691 Institutional research plan: CEZ:AV0Z10030501 Keywords : astronomy * astropohysics * Czech republic Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics

  20. Python in Astronomy 2016 (United States)

    Jenness, Tim; Robitaille, Thomas; Tollerud, Erik; Mumford, Stuart; Cruz, Kelle


    The second Python in Astronomy conference will be held from 21-25 March 2016 at the University of Washington eScience Institute in Seattle, WA, USA. Similarly to the 2015 meeting (which was held at the Lorentz Center), we are aiming to bring together researchers, Python developers, users, and educators. The conference will include presentations, tutorials, unconference sessions, and coding sprints. In addition to sharing information about state-of-the art Python Astronomy packages, the workshop will focus on improving interoperability between astronomical Python packages, providing training for new open-source contributors, and developing educational materials for Python in Astronomy. The meeting is therefore not only aimed at current developers, but also users and educators who are interested in being involved in these efforts.

  1. The Unified Astronomy Thesaurus (United States)

    Erdmann, Christopher; Frey, Katie


    The Unified Astronomy Thesaurus (UAT) is an open, interoperable and community-supported thesaurus which unifies the existing divergent and isolated Astronomy & Astrophysics vocabularies into a single high-quality, freely-available open thesaurus formalizing astronomical concepts and their inter-relationships. The UAT builds upon both the International Astronomical Union Thesaurus and the International Virtual Observatory Alliance Thesaurus with major contributions from the astronomy portions of the thesauri developed by the Institute of Physics Publishing, the American Institute of Physics, and SPIE, donated to the American Astronomical Society (AAS). In this talk, I will describe the effort behind the creation of the UAT, its continued development through the leadership of the AAS, and discuss some of its current and potential applications.

  2. Teaching Astronomy Online (United States)

    Radnofsky, Mary L.; Bobrowsky, Matthew

    This article is intended to provide an overview of the practical, pedagogical, and philosophical considerations in designing a Web-based astronomy course, and to demonstrate the educational benefits that such online courses can afford students. Because online students need to take more responsibility for their learning, faculty must make course expectations extremely clear. Online education allows for increased student participation and equal access to college by such groups as the military, the handicapped, full-time employees, and rural and senior citizens. Teaching the sciences online--especially astronomy--gives students more time to think critically about new information. This article also includes tools, checklists, and resources helpful for introducing faculty to online course development in astronomy.

  3. Journal of Astrophysics and Astronomy | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. Sergey V. Ershkov. Articles written in Journal of Astrophysics and Astronomy. Volume 38 Issue 1 March 2017 pp 5 Research Article. Forbidden Zones for Circular Regular Orbits of the Moons in Solar System, R3BP · Sergey V. Ershkov · More Details Abstract Fulltext ...

  4. A pilot study of a novel home telemonitoring system for oncology patients receiving chemotherapy. (United States)

    Nimako, Kofi; Lu, Shir-Kiong; Ayite, Bee; Priest, Kathy; Winkley, Andrew; Gunapala, Ranga; Popat, Sanjay; O'Brien, Mary Er


    We examined the accuracy and acceptability of a home telemonitoring system for patients receiving chemotherapy. Patients undergoing two cycles of chemotherapy (over six weeks) used the telemonitoring system to analyse their own blood (capillary) and to enter symptom and temperature data. The blood results obtained from self-testing were compared with those from a venous blood sample analysed in the hospital laboratory analyser (the gold standard). We also documented the number and type of alerts generated by the telemonitoring system. Acceptability (ease of use and patient satisfaction) was assessed using questionnaires. Ten patients (mean age 61 years, 60% female) provided 48-paired samples. None of the patients succeeded in obtaining all blood results within pre-defined limits of agreement (i.e. within 15% for haemoglobin, haematocrit, white cell count; and 20% for neutrophil count) during the study. However, the level of clinical agreement between the system and the laboratory standard was good; only three out of the 48 samples and two out of the 10 patients had differences in blood results that might have had clinical implications. The telemonitoring system correctly generated 42 alerts. The patients found the telemonitoring system easy to use. With further refinement this should become an acceptable component of routine clinical practice for monitoring patients receiving chemotherapy. © SAGE Publications Ltd, 2013.

  5. Conceptual design of Advanced Central Receiver Power Systems sodium-cooled receiver concept: development plan and pilot plant description. Final report

    Energy Technology Data Exchange (ETDEWEB)



    This volume encompasses Task 6 of the Phase I effort on the Advanced Central Receiver. This task included developing a plan to bring the commercial plant conceptual design into being. The base version of the plan includes a pilot plant to be designed and constructed during Phases II and III, three subsystem research experiments to be performed during Phase II, and the design and construction of a commercial demonstration plant. These plans are discussed in detail, as well as several options which could reduce both cost and schedule to achieve the overall goal of a commercial-sized demonstration plant. In evaluating pilot plant characeristics, emphasis was placed on representing commercial plant receiver characteristics and total system operation. In considering total system operation, it was recognized that a water-steam pilot plant would already be in operation, hence certain systems will already have been tested. Several receiver configurations were investigated consisting of from one to five full-size panels, with the objective of representing peak north side power for a 100-MWe plant as well as the peak flux vaue of about 1.4 MW/m/sup 2/. This goal was accomplished with a 5-panel receiver; however, the power to the edge panels is very low. Hence, with little loss, these panels can be eliminated to give a 3-panel configuration. The total absorbed thermal power is about 38 MWt, which is sufficient for about 10 MWe. A plant of this size is described.

  6. Lessons from Mayan Astronomy

    CERN Document Server

    Loeb, Abraham


    The Mayan culture collected exquisite astronomical data for over a millennium. However, it failed to come up with the breakthrough ideas of modern astronomy because the data was analyzed within a mythological culture of astrology that rested upon false but mathematically sophisticated theories about the Universe. Have we learned the necessary lessons to prevent our current scientific culture from resembling Mayan Astronomy? Clearly, data collection by itself is not a guarantee for good science as commonly assumed by funding agencies. A vibrant scientific culture should cultivate multiple approaches to analyzing existing data and to collecting new data.

  7. Solar Central Receiver Hybrid Power Systems sodium-cooled receiver concept. Final report. Volume II, Book 2. Conceptual design, Sections 5 and 6

    Energy Technology Data Exchange (ETDEWEB)



    The overall, long-term objective of the Solar Central Receiver Hybrid Power System program is to identify, characterize, and ultimately demonstrate the viability and cost effectiveness of solar/fossil, steam Rankine cycle, hybrid power systems that: (1) consist of a combined solar central receiver energy source and a nonsolar energy source at a single, common site, (2) may operate in the base, intermediate, and peaking capacity modes, (3) produce the rated output independent of variations in solar insolation, (4) provide a significant savings (50% or more) in fuel consumption, and (5) produce power at the minimum possible cost in mills/kWh. It is essential that these hybrid concepts be technically feasible and economically competitive with other systems in the near to mid-term time period (1985-1990) on a commercial scale. The program objective for Phase I is to identify and conceptually characterize solar/fossil steam Rankine cycle, commercial-scale, power plant systems that are economically viable and technically feasible. This volume contains the detailed conceptual design and cost/performance estimates and an assessment of the commercial scale solar central receiver hybrid power system. (WHK)

  8. The Cambridge encyclopaedia of astronomy

    CERN Document Server


    Astronomy has been transformed in the last two decades by a series of dramatic discoveries that have left most reference books completely out of date. The Cambridge Encyclopaedia of Astronomy presents a broadly based survey of the whole of astronomy which places emphasis on these critical new findings.

  9. Teaching Astronomy in UK Schools (United States)

    Roche, Paul; Roberts, Sarah; Newsam, Andy; Barclay, Charles


    This article attempts to summarise the good, bad and (occasionally) ugly aspects of teaching astronomy in UK schools. It covers the most common problems reported by teachers when asked about covering the astronomy/space topics in school. Particular focus is given to the GCSE Astronomy qualification offered by Edexcel (which is currently the…

  10. Quickly Creating Interactive Astronomy Illustrations (United States)

    Slater, Timothy F.


    An innate advantage for astronomy teachers is having numerous breathtaking images of the cosmos available to capture students' curiosity, imagination, and wonder. Internet-based astronomy image libraries are numerous and easy to navigate. The Astronomy Picture of the Day, the Hubble Space Telescope image archive, and the NASA Planetary…

  11. School-Based Extracurricular Astronomy (United States)

    Stanger, Jeffrey J.


    The International Year of Astronomy in 2009 focused considerable public attention on Astronomy and generated valuable resources for educators. These activities are an effective vehicle for promoting Science to students and to the wider school community. The most engaging practical astronomy activities are best delivered with sustained support from…

  12. Astronomy Education for Physics Students

    Indian Academy of Sciences (India)


    Jan 27, 2016 ... Astronomy is a very interesting subject for undergraduate students studying physics. In this paper, we report astronomy education for undergraduate students in the Physics Department of Guangzhou University, and how we are teaching astronomy to the students. Astrophysics has been rapidly developing ...

  13. The handy astronomy answer book

    CERN Document Server

    Liu, PhD, Charles


    From planetary movements and the exploration of our solar system to black holes and dark matter, this comprehensive reference simplifies all aspects of astronomy with an approachable question-and-answer format. With chapters broken into various astronomical studies—including the universe, galaxies, planets, and space exploration—this fully updated resource is an ideal companion for students, teachers, and amateur astronomers, answering more than 1,000 questions, such as Is the universe infinite? What would happen to you if you fell onto a black hole? What are the basic concepts of Einstein's special theory of relativity? and Who was the first person in space?.

  14. BER Performance of IM/DD FSO System with OOK using APD Receiver

    Directory of Open Access Journals (Sweden)

    M. I. Petković


    Full Text Available In this paper, the performance of intensity-modulated with direct detection (IM/DD free space optical (FSO system using the on-off keying (OOK and avalanche photodiode (APD receiver is observed. The gamma-gamma model is used to describe the effect of atmospheric turbulence since it provides good agreement in the wide range of atmospheric conditions. In addition, the same FSO system with equal gain combining applied at the reception is analyzed. After theoretical derivation of the expression for the bit error rate (BER, the numerical integration with previously specified relative calculation error is performed. Numerical results are presented and confirmed by Monte Carlo simulations. The effects of the FSO link and receiver parameters on the BER performance are discussed. The results illustrate that the optimal APD gain in the minimum BER sense depends considerably on the link distance, atmospheric turbulence strength and receiver temperature. In addition, the value of this optimal gain is slightly different in the case of spatial diversity application compared with single channel reception.

  15. Waste Receiving and Processing (WRAP) Facility Public Address System Review Findings

    Energy Technology Data Exchange (ETDEWEB)



    Public address system operation at the Waste Receiving and Processing (WRAP) facility was reviewed. The review was based on an Operational Readiness Review finding that public address performance was not adequate in parts of the WRAP facility. Several improvements were made to the WRAP Public Address (PA) system to correct the deficiencies noted. Speaker gain and position was optimized. A speech processor was installed to boost intelligibility in high noise areas. Additional speakers were added to improve coverage in the work areas. The results of this evaluation indicate that further PA system enhancements are not warranted. Additional speakers cannot compensate for the high background sound and high reverberation levels found in the work areas. Recommendations to improve PA system intelligibility include minor speaker adjustments, enhanced PA announcement techniques, and the use of sound reduction and abatement techniques where economically feasible.

  16. Nephrogenic systemic fibrosis in patients with chronic kidney disease who received gadopentetate dimeglumine. (United States)

    Hope, Thomas A; Herfkens, Robert J; Denianke, Kwame S; LeBoit, Phillip E; Hung, Yun-Yi; Weil, Eli


    To determine the prevalence of nephrogenic systemic fibrosis (NSF) in patients with chronic kidney disease (CKD) who have received gadopentetate dimeglumine. We retrospectively studied all patients who underwent contrast-enhanced magnetic resonance imagings (CE-MRIs) between January 1, 2004 and May 31, 2007, in the Kaiser Permanente Medical Care Program, a managed care organization providing care for more than 3.3 million residents in Northern California. All patients received gadopentetate dimeglumine. We used 4 methods to discover cases of NSF: review of pathology slides, review of coded diagnosis, review of visits to dermatologists and rheumatologists, and surveys of physicians. During the study period 115,252 CE-MRIs were performed, including 676 in 530 patients receiving dialysis (92% on chronic dialysis and 8% on acute dialysis) and 3,423 in 2,862 patients with elevated serum creatinine levels at the time of gadolinium chelate administration. One dialysis patient had a definite diagnosis of NSF. In 3 additional patients, 1 on chronic dialysis and 2 with CKD, NSF could not be ruled out. The prevalence of NSF in patients with CKD who received gadopentetate dimeglumine is lower than previously reported in patients who have received less stable formulations of gadolinium chelates. The prevalence of NSF in our patient population is likely underreported as all patients were not individually examined and histology was not available in the majority of patients. Furthermore, the prevalence is likely effected by the lower average dose and frequency of gadolinium chelate administration in this study compared with previous reports in the literature.

  17. A novel time of arrival estimation algorithm using an energy detector receiver in MMW systems (United States)

    Liang, Xiaolin; Zhang, Hao; Lyu, Tingting; Xiao, Han; Gulliver, T. Aaron


    This paper presents a new time of arrival (TOA) estimation technique using an improved energy detection (ED) receiver based on the empirical mode decomposition (EMD) in an impulse radio (IR) 60 GHz millimeter wave (MMW) system. A threshold is employed via analyzing the characteristics of the received energy values with an extreme learning machine (ELM). The effect of the channel and integration period on the TOA estimation is evaluated. Several well-known ED-based TOA algorithms are used to compare with the proposed technique. It is shown that this ELM-based technique has lower TOA estimation error compared to other approaches and provides robust performance with the IEEE 802.15.3c channel models.

  18. Long Length Contaminated Equipment Retrieval System Receiver Trailer and Transport Trailer Operations and Maintenance Manual

    Energy Technology Data Exchange (ETDEWEB)

    DALE, R.N.


    A system to accommodate the removal of long-length contaminated equipment (LLCE) from Hanford underground radioactive waste storage tanks was designed, procured, and demonstrated, via a project activity during the 1990s. The system is the Long Length Contaminated Equipment Removal System (LLCERS). LLCERS will be maintained and operated by Tank Farms Engineering and Operations organizations and other varied projects having a need for the system. The responsibility for the operation and maintenance of the LLCERS Receiver Trailer (RT) and Transport Trailer (TT) resides with the RPP Characterization Project Operations organization. The purpose of this document is to provide vendor supplied operating and maintenance (O & M) information for the RT and TT in a readily retrievable form. This information is provided this way instead of in a vendor information (VI) file to maintain configuration control of the operations baseline as described in RPP-6085, ''Configuration Management Plan for Long Length Contaminated Equipment Receiver and Transport Trailers''. Additional Operations Baseline documents are identified in RPP-6085.

  19. Optimum quantum receiver for detecting weak signals in PAM communication systems (United States)

    Sharma, Navneet; Rawat, Tarun Kumar; Parthasarathy, Harish; Gautam, Kumar


    This paper deals with the modeling of an optimum quantum receiver for pulse amplitude modulator (PAM) communication systems. The information bearing sequence {I_k}_{k=0}^{N-1} is estimated using the maximum likelihood (ML) method. The ML method is based on quantum mechanical measurements of an observable X in the Hilbert space of the quantum system at discrete times, when the Hamiltonian of the system is perturbed by an operator obtained by modulating a potential V with a PAM signal derived from the information bearing sequence {I_k}_{k=0}^{N-1}. The measurement process at each time instant causes collapse of the system state to an observable eigenstate. All probabilities of getting different outcomes from an observable are calculated using the perturbed evolution operator combined with the collapse postulate. For given probability densities, calculation of the mean square error evaluates the performance of the receiver. Finally, we present an example involving estimating an information bearing sequence that modulates a quantum electromagnetic field incident on a quantum harmonic oscillator.

  20. Financing alternatives and incentives for solar-thermal central-receiver systems

    Energy Technology Data Exchange (ETDEWEB)

    Bos, P.B.


    As a result of various recently enacted incentive and regulatory legislation combined with the new administration policy and budgetary guidelines, the commercialization of solar thermal central receiver systems will involve financing alternatives other than conventional utility financing. This study was conducted to identify these potential financing alternatives and the associated requirements and impacts on the Department of Energy program. Based upon this analysis, it is concluded that the current alternative financing window is extremely short (through 1985), and that an extension or at the least a gradual phasing out, of the solar tax credits is necessary for the successful transfer of the central receiver technology to the private sector. Furthermore, throughout this time period, continued government support of the R and D activities is necessary to provide the necessary confidence in this technology for the private (financial) sector to underwrite this technology transfer. Consequently, even though the central receiver technology shows high promise for replacing a significant fraction of the oil/gas-fired utility industry peaking and intermediate generation, the current readiness status of this technology still requires further direct and indirect government support for a successful technology transfer. The direct government research and development support will provide the basis for a technological readiness and confidence, whereas the indirect tax incentive support serves to underwrite the extraordinary risks associated with the technology transfer. These support requirements need only be limited to and decreasing during this technology transfer phase, since as the systems approach successful full-scale commercialization, the extraordinary risks will be gradually eliminated. At the time of commercialization the system's value should be on a par with the installed system's cost.

  1. Astronomy on the Walls (United States)

    Santascoy, J.


    Many of us are interested in increasing youth and minority involvement in the sciences. Using art that integrates images of space exploration with ethnic astronomical mythology may increase participation in astronomy in general, while also forming a bridge to underrepresented communities. This paper describes a freely available presentation of Carlos Callejo's Discover the Secrets of the Universe Through the Library for outreach.

  2. Astronomy Video Contest (United States)

    McFarland, John


    During Galileo's lifetime his staunchest supporter was Johannes Kepler, Imperial Mathematician to the Holy Roman Emperor. Johannes Kepler will be in St. Louis to personally offer a tribute to Galileo. Set Galileo's astronomy discoveries to music and you get the newest song by the well known acappella group, THE CHROMATICS. The song, entitled "Shoulders of Giants” was written specifically for IYA-2009 and will be debuted at this conference. The song will also be used as a base to create a music video by synchronizing a person's own images to the song's lyrics and tempo. Thousands of people already do this for fun and post their videos on YOU TUBE and other sites. The ASTRONOMY VIDEO CONTEST will be launched as a vehicle to excite, enthuse and educate people about astronomy and science. It will be an annual event administered by the Johannes Kepler Project and will continue to foster the goals of IYA-2009 for years to come. During this presentation the basic categories, rules, and prizes for the Astronomy Video Contest will be covered and finally the new song "Shoulders of Giants” by THE CHROMATICS will be unveiled

  3. Teaching Astronomy Using Tracker (United States)

    Belloni, Mario; Christian, Wolfgang; Brown, Douglas


    A recent paper in this journal presented a set of innovative uses of video analysis for introductory physics using Tracker. In addition, numerous other papers have described how video analysis can be a meaningful part of introductory courses. Yet despite this, there are few resources for using video analysis in introductory astronomy classes. In…

  4. Physics and astronomy

    CSIR Research Space (South Africa)

    Moraal, H


    Full Text Available The chapter is about physics and astronomy. The chapter gives a background about the origins of physics in South Africa. After the CSIR was founded in 1945, physics emerged as a nationwide and unified discipline. The authors show how physics...

  5. Division x: Radio Astronomy

    NARCIS (Netherlands)

    Taylor, Russ; Chapman, Jessica; Rendong, Nan; Carilli, Christopher; Giovannini, Gabriele; Hills, Richard; Hirabayashi, Hisashi; Jonas, Justin; Lazio, Joseph; Morganti, Raffaella; Rubio, Monica; Shastri, Prajval

    This triennium has seen a phenomenal investment in development of observational radio astronomy facilities in all parts of the globe at a scale that significantly impacts the international community. This includes both major enhancements such as the transition from the VLA to the EVLA in North

  6. Gravitational-Wave Astronomy

    Indian Academy of Sciences (India)

    We present a broad overview of the emerging field of gravitational-wave astronomy. Although gravitational waves have not been directly de- tected yet, the worldwide scientific community is engaged in an exciting search for these elusive waves. Once detected, they will open up a new observational window to the Universe.

  7. SymptomCare@Home: Developing an Integrated Symptom Monitoring and Management System for Outpatients Receiving Chemotherapy. (United States)

    Beck, Susan L; Eaton, Linda H; Echeverria, Christina; Mooney, Kathi H


    SymptomCare@Home, an integrated symptom monitoring and management system, was designed as part of randomized clinical trials to help patients with cancer who receive chemotherapy in ambulatory clinics and often experience significant symptoms at home. An iterative design process was informed by chronic disease management theory and features of assessment and clinical decision support systems used in other diseases. Key stakeholders participated in the design process: nurse scientists, clinical experts, bioinformatics experts, and computer programmers. Especially important was input from end users, patients, and nurse practitioners participating in a series of studies testing the system. The system includes both a patient and clinician interface and fully integrates two electronic subsystems: a telephone computer-linked interactive voice response system and a Web-based Decision Support-Symptom Management System. Key features include (1) daily symptom monitoring, (2) self-management coaching, (3) alerting, and (4) nurse practitioner follow-up. The nurse practitioner is distinctively positioned to provide assessment, education, support, and pharmacologic and nonpharmacologic interventions to intensify management of poorly controlled symptoms at home. SymptomCare@Home is a model for providing telehealth. The system facilitates using evidence-based guidelines as part of a comprehensive symptom management approach. The design process and system features can be applied to other diseases and conditions.

  8. Strategies for Teaching Astronomy (United States)

    Bennett, J.


    No matter whether you are teaching school children, undergraduates, or colleagues, a few key strategies are always useful. I will present and give examples for the following five key strategies for teaching astronomy. 1. Provide a Contextual Framework: It is much easier to learn new facts or concepts if they can be ``binned" into some kind of pre-existing mental framework. Unless your listeners are already familiar with the basic ideas of modern astronomy (such as the hierarchy of structure in the universe, the scale of the universe, and the origin of the universe), you must provide this before going into the details of how we've developed this modern picture through history. 2. Create Conditions for Conceptual Change: Many people hold misconceptions about astronomical ideas. Therefore we cannot teach them the correct ideas unless we first help them unlearn their prior misconceptions. 3. Make the Material Relevant: It's human nature to be more interested in subjects that seem relevant to our lives. Therefore we must always show students the many connections between astronomy and their personal concerns, such as emphasizing how we are ``star stuff" (in the words of Carl Sagan), how studying other planets helps us understand our own, and so on. 4. Limit Use of Jargon: The number of new terms in many introductory astronomy books is larger than the number of words taught in many first courses in foreign language. This means the books are essentially teaching astronomy in a foreign language, which is a clear recipe for failure. We must find ways to replace jargon with plain language. 5. Challenge Your Students: Don't dumb your teaching down; by and large, students will rise to meet your expectations, as long as you follow the other strategies and practice good teaching.

  9. Sender-receiver systems and applying information theory for quantitative synthetic biology. (United States)

    Barcena Menendez, Diego; Senthivel, Vivek Raj; Isalan, Mark


    Sender-receiver (S-R) systems abound in biology, with communication systems sending information in various forms. Information theory provides a quantitative basis for analysing these processes and is being applied to study natural genetic, enzymatic and neural networks. Recent advances in synthetic biology are providing us with a wealth of artificial S-R systems, giving us quantitative control over networks with a finite number of well-characterised components. Combining the two approaches can help to predict how to maximise signalling robustness, and will allow us to make increasingly complex biological computers. Ultimately, pushing the boundaries of synthetic biology will require moving beyond engineering the flow of information and towards building more sophisticated circuits that interpret biological meaning. Copyright © 2014. Published by Elsevier Ltd.

  10. Sender–receiver systems and applying information theory for quantitative synthetic biology (United States)

    Barcena Menendez, Diego; Senthivel, Vivek Raj; Isalan, Mark


    Sender–receiver (S–R) systems abound in biology, with communication systems sending information in various forms. Information theory provides a quantitative basis for analysing these processes and is being applied to study natural genetic, enzymatic and neural networks. Recent advances in synthetic biology are providing us with a wealth of artificial S–R systems, giving us quantitative control over networks with a finite number of well-characterised components. Combining the two approaches can help to predict how to maximise signalling robustness, and will allow us to make increasingly complex biological computers. Ultimately, pushing the boundaries of synthetic biology will require moving beyond engineering the flow of information and towards building more sophisticated circuits that interpret biological meaning. PMID:25282688

  11. Advanced Receiver Design for Mitigating Multiple RF Impairments in OFDM Systems: Algorithms and RF Measurements

    Directory of Open Access Journals (Sweden)

    Adnan Kiayani


    Full Text Available Direct-conversion architecture-based orthogonal frequency division multiplexing (OFDM systems are troubled by impairments such as in-phase and quadrature-phase (I/Q imbalance and carrier frequency offset (CFO. These impairments are unavoidable in any practical implementation and severely degrade the obtainable link performance. In this contribution, we study the joint impact of frequency-selective I/Q imbalance at both transmitter and receiver together with channel distortions and CFO error. Two estimation and compensation structures based on different pilot patterns are proposed for coping with such impairments. The first structure is based on preamble pilot pattern while the second one assumes a sparse pilot pattern. The proposed estimation/compensation structures are able to separate the individual impairments, which are then compensated in the reverse order of their appearance at the receiver. We present time-domain estimation and compensation algorithms for receiver I/Q imbalance and CFO and propose low-complexity algorithms for the compensation of channel distortions and transmitter IQ imbalance. The performance of the compensation algorithms is investigated with computer simulations as well as with practical radio frequency (RF measurements. The performance results indicate that the proposed techniques provide close to the ideal performance both in simulations and measurements.

  12. High-temperature thermal storage systems for advanced solar receivers materials selections (United States)

    Wilson, D. F.; Devan, J. H.; Howell, M.


    Advanced space power systems that use solar energy and Brayton or Stirling heat engines require thermal energy storage (TES) systems to operate continuously through periods of shade. The receiver storage units, key elements in both Brayton and Stirling systems, are designed to use the latent heat of fusion of phase-change materials (PCMs). The power systems under current consideration for near-future National Aeronautics and Space Administration space missions require working fluid temperatures in the 1100 to 1400 K range. The PCMs under current investigation that gave liquid temperatures within this range are the fluoride family of salts. However, these salts have low thermal conductivity, which causes large temperature gradients in the storage systems. Improvements can be obtained, however, with the use of thermal conductivity enhancements or metallic PCMs. In fact, if suitable containment materials can be found, the use of metallic PCMs would virtually eliminate the orbit associated temperature variations in TES systems. The high thermal conductivity and generally low volume change on melting of germanium and alloys based on silicon make them attractive for storage of thermal energy in space power systems. An approach to solving the containment problem, involving both chemical and physical compatibility, preparation of NiSi/NiSi2, and initial results for containment of germanium and NiSi/NiSi2, are presented.

  13. Discovery and Classification in Astronomy (United States)

    Dick, Steven J.


    Three decades after Martin Harwit's pioneering Cosmic Discovery (1981), and following on the recent IAU Symposium "Accelerating the Rate of Astronomical Discovery,” we have revisited the problem of discovery in astronomy, emphasizing new classes of objects. 82 such classes have been identified and analyzed, including 22 in the realm of the planets, 36 in the realm of the stars, and 24 in the realm of the galaxies. We find an extended structure of discovery, consisting of detection, interpretation and understanding, each with its own nuances and a microstructure including conceptual, technological and social roles. This is true with a remarkable degree of consistency over the last 400 years of telescopic astronomy, ranging from Galileo's discovery of satellites, planetary rings and star clusters, to the discovery of quasars and pulsars. Telescopes have served as "engines of discovery” in several ways, ranging from telescope size and sensitivity (planetary nebulae and spiral galaxies), to specialized detectors (TNOs) and the opening of the electromagnetic spectrum for astronomy (pulsars, pulsar planets, and most active galaxies). A few classes (radiation belts, the solar wind and cosmic rays), were initially discovered without the telescope. Classification also plays an important role in discovery. While it might seem that classification marks the end of discovery, or a post-discovery phase, in fact it often marks the beginning, even a pre-discovery phase. Nowhere is this more clearly seen than in the classification of stellar spectra, long before dwarfs, giants and supergiants were known, or their evolutionary sequence recognized. Classification may also be part of a post-discovery phase, as in the MK system of stellar classification, constructed after the discovery of stellar luminosity classes. Some classes are declared rather than discovered, as in the case of gas and ice giant planets, and, infamously, Pluto as a dwarf planet.

  14. The General History of Astronomy (United States)

    Taton, René; Wilson, Curtis; Hoskin, editor Michael, , General


    Part V. Early Phases in the Reception of Newton's Theory: 14. The vortex theory in competition with Newtonian celestial dynamics Eric J. Aiton; 15. The shape of the Earth Seymour L. Chapin; 16. Clairaut and the motion of the lunar apse: The inverse-square law undergoes a test Craig B. Waff; 17. The precession of the equinoxes from Newton to d'Alembert and Euler Curtis Wilson; 18. The solar tables of Lacaille and the lunar tables of Mayer Eric G. Forbes and Curtis Wilson; 19. Predicting the mid-eighteenth-century return of Halley's Comet Craig B. Waff; Part VI. Celestial Mechanics During the Eighteenth Century: 20. The problem of perturbation analytically treated: Euler, Clairaut, d'Alembert Curtis Wilson; 21. The work of Lagrange in celestial mechanics Curtis Wilson; 22. Laplace Bruno Morando; Part VII. Observational Astronomy and the Application of Theory in the Late Eighteenth and Early Nineteenth Century: 23. Measuring solar parallax: The Venus transits of 1761 and 1769 and their nineteenth-century sequels Albert Van Helden; 24. The discovery of Uranus, the Titius-Bode and the asteroids Michael Hoskin; 25. Eighteenth-and nineteenth century developments in the theory and practice of orbit determination Brian G. Marsden; 26. The introduction of statistical reasoning into astronomy: from Newton to Poincaré Oscar Sheynin; 27. Astronomy and the theory of errors: from the method of averages to the method of least squares F. Schmeidler; Part VIII. The Development of Theory During the Nineteenth Century: 28. The golden age of celestial mechanics Bruno Morando; Part IX. The Application of Celestial Mechanics to the Solar System to the End of the Nineteenth Century: 29. Three centuries of lunar and planetary ephemerides and tables Bruno Morando; 30. Satellite ephemerides to 1900 Yoshihide Kozai; Illustrations; Combined index for Parts 2A and 2B.

  15. Promoting mental model building in astronomy education (United States)

    Taylor, Ian; Barker, Miles; Jones, Alister


    While astronomy has recently re-emerged in many science curricula, there remain unresolved teaching and learning difficulties peculiar to astronomy education. This paper argues that mental model building, the core process in astronomy itself, should be reflected in astronomy education. Also, this crucial skill may promote a better understanding of the nature of science by pupils and it resonates with current understandings about pupils' learning in science. However, three practical questions to be considered are: the expressed reservations about the connection between mental model building and meaningful learning; the earliest age of pupils for whom mental model building is appropriate; and the lack of research into pupils' prior ideas about the role of models in science. The paper describes how a four-phase general pedagogical strategy was adopted to create an astronomy teaching and learning package to promote mental model building. The package consists of notes explaining the mental model building followed by an overview of the teaching-learning approach and suggested outlines of the 12 lessons. Research investigated whether that package can help Year 7-8 pupils interrogate and refine their mental models of the Sun-Earth-Moon system within the constraints of an ordinary class of 33 pupils. The results showed that all four phases of the general strategy were necessary and effective in that most pupils were able successively and successfully to critique their mental models of the Sun-Earth-Moon system while also achieving traditional astronomy knowledge goals. Implications are that pupils as young as Year 7-8 may be able to construct other appropriate mental models, such as those for biological populations, atomic structure and plate tectonics.

  16. Solar Central Receiver Hybrid Power Systems sodium-cooled receiver concept. Final report. Volume II, Book 1. Conceptual design, Sections 1 through 4

    Energy Technology Data Exchange (ETDEWEB)



    The overall, long-term objective of the Solar Central Receiver Hybrid Power System program is to identify, characterize, and ultimately demonstrate the viability and cost effectiveness of solar/fossil, steam Rankine cycle, hybrid power systems that: (1) consist of a combined solar central receiver energy source and a nonsolar energy source at a single, common site, (2) may operate in the base, intermediate, and peaking capacity modes, (3) produce the rated output independent of variations in solar insolation, (4) provide a significant savings (50% or more) in fuel consumption, and (5) produce power at the minimum possible cost in mills/kWh. It is essential that these hybrid concepts be technically feasible and economically competitive with other systems in the near to mid-term time period (1985-1990) on a commercial scale. The program objective for Phase I is to identify and conceptually characterize solar/fossil steam Rankine cycle, commercial-scale, power plant systems that are economically viable and technically feasible. This volume presents in detail the market analysis, parametric analysis, and the selection process for the preferred system. (WHK)

  17. Optical receiving system based on a compound parabolic concentrator and a hemispherical lens for visible light communication. (United States)

    Wang, Yun; Lan, Tian; Ni, Guoqiang


    We propose a scheme for designing a new optical receiving system that can reduce the received-energy spot size via integration of a compound parabolic concentrator with a hemispherical lens. SolidWorks is used to model the receiving system, while TracePro is employed for simulations. The field of view is set to 30° and the radius of the compound parabolic concentrator outlet is 5 mm, which is also the radius of the hemispherical lens. Ray-tracing results show that under the given simulation conditions, the radius of the spot area is reduced from 5 to 3 mm at the receiving system and the gain is 5.2. In regard to the relations between received power and the radius of the hemispherical lens R, and the received power and the distance d between the compound parabolic concentrator and hemispherical lens, our detailed analysis yields the following characteristics: (1) the received power increases as R increases, but decreases as d increases; (2) as R increases, the spot area increases and the received flux is dispersed over the receiving plane, which dispersion is disadvantageous for high-speed communication; (3) the gain of the receiving system also varies with R and d; (4) an increase in d leads to decrease in the received flux and gain when d>-2  mm. Based on these characteristics, we set R=5  mm and calculate the energy efficiency. We obtain maximum energy efficiencies for different detection areas.

  18. What's New in Astronomy for 2012? (United States)

    Wilkinson, John


    There's always something new happening in the field of Astronomy. This includes the immediate environment surrounding Earth, the Solar system and the universe. This article looks at some of the recent research astronomers have been undertaking this year. Each article has reference to a web site so teachers can find out more information or ask…

  19. Highlights of Astronomy, Vol. 15 (United States)

    Corbett, Ian


    Preface; Part I. Gruber Cosmology Prize Lecture; Part II. Invited Discourses; Part III. Joint Discussions: 1. Dark matter in early-type galaxies Léon V. E. Koopmans and Tommaso Treu; 2. Diffuse light in galaxy clusters Magda Arnaboldi and Ortwin Gerhard; 3. Neutron stars - timing in extreme environments Tomaso Belloni, Mariano Méndez and Chengmin Zhang; 4. Progress in understanding the physics of Ap and related stars Margarida Cunha; 5. Modelling the Milky Way in the age of Gaia Annie C. Robin; 6. Time and astronomy Pascale Defraigne; 7. Astrophysical outflows and associated accretion phenomena Elisabete M. de Gouveia Dal Pino and Alex C. Raga; 8. Hot interstellar matter in elliptical galaxies Dong-Woo Kim and Silvia Pellegrini; 9. Are the fundamental constants varying with time? Paolo Molaro and Elisabeth Vangioni; 10. 3D views on cool stellar atmospheres - theory meets observation K. N. Nagendra, P. Bonifacio and H. G. Ludwig; 11. New advances in helio- and astero-seismology; 12. The first galaxies - theoretical predictions and observational clues; 13. Eta Carinae in the context of the most massive stars Theodore R. Gull and Augusto Damineli; 14. The ISM of galaxies in the far-infrared and sub-millimetre; 15. Magnetic fields in diffuse media Elisabete M. de Gouveia Dal Pino and Alex Lazarian; 16. IHY global campaign - whole heliosphere interval; Part IV. Special Sessions: SpS 1. IR and sub-mm spectroscopy - a new tool for studying stellar evolution Glenn Wahlgren, Hans Käufl and Florian Kerber; SpS 2. The international year of astronomy Pedro Russo, Catherine Cesarsky and Lars Lindberg Christensen; SpS 3. Astronomy in Antarctica in 2009 Michael G. Burton; SpS 4. Astronomy education between past and future J. P. De Greve; SpS 5. Accelerating the rate of astronomical discovery Ray P. Norris; SpS 6. Planetary systems as potential sites for life Régis Courtin, Alan Boss and Michel Mayor; SpS 7. Young stars, brown dwarfs, and protoplanetary disks Jane Gregorio

  20. A Three-Year Program of Micro- and Nano-System Technology Development for X-Ray Astronomy (United States)

    Canizares, Claude R.


    For many years the work at MIT aimed at the development of new concepts and technologies for space experiments in high-energy astrophysics, but not explicitly supported by flight programs, has been supported. This work has yielded new devices and techniques for X-ray astronomy, primarily low-noise, deep-depletion charge-coupled devices (CCDS) for spectrally-resolved X-ray imaging, and high-performance transmission gratings for high-resolution X-ray spectroscopy. Among the most significant recent achievements have been the development by G. Ricker and associates of the X-ray CCD camera flying on ASCA, and currently in development for AXAF and Astro-E, and the development by C. Canizares and associates of thick, 200 nm-period transmission gratings employing the phenomenon of phase shifting for high-resolution X-ray spectroscopy up to energies of 8- 1 0 keV that is essential for the operation of the AXAF High Energy Transmission Grating Spectrometer (HETGS). Through the current SR&T grant, the latter technology is now being extended successfully to the fabrication of 100 nm-period transmission gratings, which have twice the dispersion of the AXAF gratings. We note that, among other outcomes, the modest investments of past SR&T Grants at MIT resulted in the development of the key technologies for fully one-half of the scientific instrumentation on AXAF. In addition, NASA flight programs that have benefited from previous SR&T support at MIT include the SAS 3 X-ray Observatory, which carried the first rotation modulation collimator, the Focal Plane Crystal Spectrometer (FPCS) on the Einstein Observatory, the CCD cameras on ASCA and planned for Astro-E, the High Energy Transient Experiment (HETE), the Solar EUV Monitor on the Solar and Heliospheric Observatory (SOHO), the Medium Energy Neutral Atom imager (MENA) on the Image for Magnetopause-to-aurora Global Exploration (IMAGE) mission, and the recently-approved Two Wide-Angle Imaging Neutral-atom Spectrometers (TWINS

  1. Grote Reber, Radio Astronomy Pioneer, Dies (United States)


    something of a minor tourist attraction, he later recalled. Using electronics he designed and built that pushed the technical capabilities of the era, Reber succeeded in detecting "cosmic static" in 1939. In 1941, Reber produced the first radio map of the sky, based on a series of systematic observations. His radio-astronomy work continued over the next several years. Though not a professional scientist, his research results were published in a number of prestigious technical journals, including Nature, the Astrophysical Journal, the Proceedings of the Institute of Radio Engineers and the Journal of Geophysical Research. Reber also received a number of honors normally reserved for scientists professionally trained in astronomy, including the American Astronomical Society's Henry Norris Russell Lectureship and the Astronomical Society of the Pacific's Bruce Medal in 1962, the National Radio Astronomy Observatory's Jansky Lectureship in 1975, and the Royal Astronomical Society's Jackson-Gwilt Medal in 1983. Reber's original dish antenna now is on display at the National Radio Astronomy Observatory's site in Green Bank, West Virginia, where Reber worked in the late 1950s. All of his scientific papers and records as well as his personal and scientific correspondence are held by the NRAO, and will be exhibited in the observatory's planned new library in Charlottesville, Virginia. Reber's amateur-radio callsign, W9GFZ, is held by the NRAO Amateur Radio Club. This callsign was used on the air for the first time since the 1930s on August 25, 2000, to mark the dedication of the Robert C. Byrd Green Bank Telescope. The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

  2. Nocardial cerebellar abscess in a case of systemic Lupus erythematosus receiving long term corticotherapy

    Directory of Open Access Journals (Sweden)

    Saberi H


    Full Text Available Central nervous system ranks among the favorite sites to get involved by Nocardia astroides. This opportunistic organism complicates many disorders characterized by cellular or humoral immunity disturbances.A 36-year-old woman is being presented, known to have systemic lupus erythematosus (SLE and having received a two year course of corticosteroid treatment. Cerebellar abscess was found on diagnostic imagings performed because of heddaches and dysequilibrium of two weeks duration.Craniectomy was performed and the abscess excised. Nocardia astroides grew in the pus culture. On switching the empirical therapy to a combination of trimethoprimsulfamethoxazole and vancomycin, the patient exhibited dramatic improvement in symptoms later on and postoperative imaging showed an absence of the lesion. We recommend a high index of clinical suspicion for nocardia abscess in patients suffering from SLE and presenting with neurological treatment presents the only plausible option

  3. Performance analysis of underlay cognitive multihop regenerative relaying systems with multiple primary receivers

    KAUST Repository

    Hyadi, Amal


    Multihop relaying is an efficient strategy to improve the connectivity and extend the coverage area of secondary networks in underlay cognitive systems. In this work, we provide a comprehensive performance study of cognitive multihop regenerative relaying systems in an underlay spectrum sharing scenario with the presence of multiple primary receivers. Both interference power and peak power constraints are taken into account. In our analysis, all the links are subject to independent, non-identically distributed Nakagami-m fading. We derive closed-form expressions for the outage probability, high-order amount of fading, bit error rate, symbol error rate, and ergodic capacity. Different scenarios are presented to illustrate the obtained results and Monte Carlo simulations confirm the accuracy of our analytical derivations. © 2013 IEEE.

  4. Low Complexity Precoder and Receiver Design for Massive MIMO Systems: A Large System Analysis using Random Matrix Theory

    KAUST Repository

    Sifaou, Houssem


    Massive MIMO systems are shown to be a promising technology for next generations of wireless communication networks. The realization of the attractive merits promised by massive MIMO systems requires advanced linear precoding and receiving techniques in order to mitigate the interference in downlink and uplink transmissions. This work considers the precoder and receiver design in massive MIMO systems. We first consider the design of the linear precoder and receiver that maximize the minimum signal-to-interference-plus-noise ratio (SINR) subject to a given power constraint. The analysis is carried out under the asymptotic regime in which the number of the BS antennas and that of the users grow large with a bounded ratio. This allows us to leverage tools from random matrix theory in order to approximate the parameters of the optimal linear precoder and receiver by their deterministic approximations. Such a result is of valuable practical interest, as it provides a handier way to implement the optimal precoder and receiver. To reduce further the complexity, we propose to apply the truncated polynomial expansion (TPE) concept on a per-user basis to approximate the inverse of large matrices that appear on the expressions of the optimal linear transceivers. Using tools from random matrix theory, we determine deterministic approximations of the SINR and the transmit power in the asymptotic regime. Then, the optimal per-user weight coe cients that solve the max-min SINR problem are derived. The simulation results show that the proposed precoder and receiver provide very close to optimal performance while reducing signi cantly the computational complexity. As a second part of this work, the TPE technique in a per-user basis is applied to the optimal linear precoding that minimizes the transmit power while satisfying a set of target SINR constraints. Due to the emerging research eld of green cellular networks, such a problem is receiving increasing interest nowadays. Closed

  5. 3D Virtual Reality for Teaching Astronomy (United States)

    Speck, Angela; Ruzhitskaya, L.; Laffey, J.; Ding, N.


    We are developing 3D virtual learning environments (VLEs) as learning materials for an undergraduate astronomy course, in which will utilize advances both in technologies available and in our understanding of the social nature of learning. These learning materials will be used to test whether such VLEs can indeed augment science learning so that it is more engaging, active, visual and effective. Our project focuses on the challenges and requirements of introductory college astronomy classes. Here we present our virtual world of the Jupiter system and how we plan to implement it to allow students to learn course material - physical laws and concepts in astronomy - while engaging them into exploration of the Jupiter's system, encouraging their imagination, curiosity, and motivation. The VLE can allow students to work individually or collaboratively. The 3D world also provides an opportunity for research in astronomy education to investigate impact of social interaction, gaming features, and use of manipulatives offered by a learning tool on students’ motivation and learning outcomes. Use of this VLE is also a valuable source for exploration of how the learners’ spatial awareness can be enhanced by working in 3D environment. We will present the Jupiter-system environment along with a preliminary study of the efficacy and usability of our Jupiter 3D VLE.

  6. Books Received

    Indian Academy of Sciences (India)

    The Language of the Genes. Steve Jones. Flamingo. 1993, Rs.243.00. Late Night Thoughts of Listening to Mahler's Ninth Symphony. Lewis Thomas. Penguin Books. 1983, Rs.309.00. Safety Evaluation of. Environmental Chemicals. T S S Dikshith. New Age International. 1996, Rs.350.00. Vedic Astronomy. P V Holay.

  7. Astronomy and astrology (United States)

    Zarka, Philippe


    Astrology meets a large success in our societies, from the private to the political sphere as well as in the media, in spite of the demonstrated inaccuracy of its psychological as well as operational predictions. We analyse here the relations between astrology and astronomy, as well as the criticisms opposed by the latter to the former. We show that most of these criticisms are weak. Much stronger ones emerge from the analysis of the astrological practice compared to the scientific method, leading us to conclude to the non-scientificity of astrology. Then we return to the success of astrology, and from its analysis we propose a renewed (and prophylactic) rôle for astronomy in society.

  8. Conceptual design of solar central-receiver hybrid power system: sodium-cooled-receiver concept. Volume I of II. Conceptual design

    Energy Technology Data Exchange (ETDEWEB)


    A market analysis is reported consisting of estimates of overall market size derived from projections of electric power growth, examination of utility plans, and projections of potential regulatory action. Market share is projected by comparisons of the levelized costs of busbar power produced by hybrid coal solar units with costs of other electric power producers such as coal only, nuclear and solar only units. Parametric analyses of the major subsystems, consisting of the collector, receiver, storage, non-solar, electric power generation, and master control subsystems were conducted over a wide range of independent parameters in order to define subsystem operation and interfaces for use in the preferred system selection studies. The selection of the system, subsystems, and components of the 0.8 and 1.4 solar multiple sodium-cooled hybrid central receiver configurations were done. Technically feasible alternatives were compared on an economic basis. Detailed conceptual designs of the selected system concepts for the 0.8 and 1.4 solar multiple plants are presented. Cost estimates are also presented for both plants based on the conceptual designs. (LEW)

  9. Archaeology and astronomy (United States)


    MEETING REPORT The interaction between archaeology and astronomy has a long, tangled and not entirely creditable history, marred by misunderstandings on both sides. But statistics and cultural awareness are bringing a better picture of how and why lasting monuments such as Stonehenge were built. Sue Bowler reports on a joint meeting of the Royal Astronomical Society and the Prehistoric Society, held at Jodrell Bank on 17 July 2009.

  10. Astronomy on a Landfill (United States)

    Venner, Laura


    Engaging "K-to-Gray” audiences (children, families, and older adults) in astronomical activities is one of the main goals of the NJMC Center for Environmental and Scientific Education and the William D. McDowell Observatory located in Lyndhurst, NJ. Perched atop a closed and reclaimed municipal solid waste landfill, our new LEED - certified building (certification pending) and William D. McDowell observatory will assist in bringing the goals of IYA 2009 to the approximately 25,000 students and 15,000 adults that visit our site from the NY/NJ region each year. Diversifying our traditional environmental science offerings, we have incorporated astronomy into our repertoire with "The Sun Through Time” module, which includes storytelling, cultural astronomy, telescope anatomy, and other activities that are based on the electromagnetic spectrum and our current knowledge of the sun. These lessons have also been modified to bring astronomy to underserved communities, specifically those individuals that have dexterity or cognitive ability differences. The program is conducted in a classroom setting and is designed to meet New Jersey Core Curriculum Content Standards. With the installation of our new 20” telescope, students and amateur astronomers will be given the opportunity to perform rudimentary research. In addition, a program is in development that will allow individuals to measure local sky brightness and understand the effects of light pollution on astronomical viewing. Teaching astronomy in an urban setting presents many challenges. All individuals, regardless of ability level or location, should be given the opportunity to be exposed to the wonders of the universe and the MEC/CESE has been successful in providing those opportunities.

  11. Gravitational Wave Astronomy

    CERN Multimedia

    CERN. Geneva


    Gravitational wave astronomy is expected to become an observational field within the next decade. First direct detection of gravitational waves is possible with existing terrestrial-based detectors, and highly probable with proposed upgrades. In this three-part lecture series, we give an overview of the field, including material on gravitional wave sources, detection methods, some details of interferometric detectors, data analysis methods, and current results from observational data-taking runs of the LIGO and GEO projects.

  12. Conceptual design of advanced central receiver power systems sodium-cooled receiver concept. Volume 4. Commercial and pilot plant cost data. Final report

    Energy Technology Data Exchange (ETDEWEB)


    This volume of the advanced central receiver final report presents the cost data using the cost breakdown structure identified in the preliminary specification. Cost summaries are presented in the following sections for the 100-MWe and 281-MWe commercial plant and a 10-MWe pilot plant. Cost substantiation data for this volume are presented in the appendices. Other cost summary data include Nth plant data for the 100-MWe and 281-MWe commercial plants, and a summary for the alternative concept air-rock storage system. The main description of the plant costing technique occurs as part of Section II for the 100-MWe baseline concept.

  13. The New Digital-Receiver-Based System for Antiproton Beam Diagnostics

    CERN Document Server

    Angoletta, Maria Elena; Ludwig, M; Marqversen, O; Pedersen, F


    An innovative system to measure antiproton beam intensity, momentum spread and mean momentum in CERN's Antiproton Decelerator (AD) is described. This system is based on a state-of-the-art Digital Receiver (DRX) board, consisting of 8 Digital Down-Converter (DDC) chips and one Digital Signal Processor (DSP). An ultra-low-noise, wide-band AC beam transformer (0.2 MHz - 30 MHz) is used to measure AC beam current modulation. For bunched beams, the intensity is obtained by measuring the amplitude of the fundamental and second RF Fourier components. On the magnetic plateaus the beam is debunched for stochastic or electron cooling and longitudinal beam properties (intensity, momentum spread and mean momentum) are measured by FFT-based spectral analysis of Schottky signals. The system thus provides real time information characterising the machine performance; it has been used for troubleshooting and to fine-tune the AD, thus achieving further improved performances. This system has been operating since May 2000 and ty...

  14. Receiver design for SPAD-based VLC systems under Poisson-Gaussian mixed noise model. (United States)

    Mao, Tianqi; Wang, Zhaocheng; Wang, Qi


    Single-photon avalanche diode (SPAD) is a promising photosensor because of its high sensitivity to optical signals in weak illuminance environment. Recently, it has drawn much attention from researchers in visible light communications (VLC). However, existing literature only deals with the simplified channel model, which only considers the effects of Poisson noise introduced by SPAD, but neglects other noise sources. Specifically, when an analog SPAD detector is applied, there exists Gaussian thermal noise generated by the transimpedance amplifier (TIA) and the digital-to-analog converter (D/A). Therefore, in this paper, we propose an SPAD-based VLC system with pulse-amplitude-modulation (PAM) under Poisson-Gaussian mixed noise model, where Gaussian-distributed thermal noise at the receiver is also investigated. The closed-form conditional likelihood of received signals is derived using the Laplace transform and the saddle-point approximation method, and the corresponding quasi-maximum-likelihood (quasi-ML) detector is proposed. Furthermore, the Poisson-Gaussian-distributed signals are converted to Gaussian variables with the aid of the generalized Anscombe transform (GAT), leading to an equivalent additive white Gaussian noise (AWGN) channel, and a hard-decision-based detector is invoked. Simulation results demonstrate that, the proposed GAT-based detector can reduce the computational complexity with marginal performance loss compared with the proposed quasi-ML detector, and both detectors are capable of accurately demodulating the SPAD-based PAM signals.

  15. CMOS photodetectors/receivers for smart-pixel based photonic systems (United States)

    Tang, Jianjing; Konanki, Sunil; Seshadri, Bharath; Lee, Boon K.; Chi, Robert C. J.; Steckl, Andrew J.; Beyette, Fred R., Jr.


    The design, characterization and evaluation of CMOS based silicon photodetectors/photoreceivers suitable for smart-pixel based applications are presented. Implemented with a conventional CMOS fabrication process, these photodetectors/receiver circuits can be reliably fabricated for smart-pixel based photonic information processing systems that combine the parallelism associated with optics and the data processing capabilities associated with CMOS logic. Several different CMOS based photodetector structures including p-n junction detectors and bipolar phototransistors are presented. Simulation results indicate that the p-n junction detectors will provide photocurrents in the range of nanoamps with rise/fall times on the order of picoseconds. Although slower response is expected with the phototransistor structure, the optoelectronic gain increases the photocurrent to the microamps range. In addition to fabrication and evaluation of individual photodetectors, we present the design and evaluation of high gain photoreceiver array. Based on a standard 1.2 micrometer CMOS fabrication process the monolithic photodetector/receiver circuit includes a bipolar phototransistor, a three-stage current amplifier and a differential amplifier that produces output at digital logic levels. The photoreceiver with high gain and adjustable threshold has a wide dynamic range. For a reference voltage of 3.2 V, the optical power threshold has been measured at less than 1 nW. A page-oriented optical data detection is demonstrated using a 5 X 5 smart-pixel photoreceiver array.

  16. A Direct Conversion Receiver Adopting Balanced Three-Phase Analog System (United States)

    Yamaji, Takafumi; Ueno, Takeshi; Itakura, Tetsuro

    Recent advanced technology makes digital circuits small and the number of digital functional blocks that can be integrated on a single chip is increasing rapidly. On the other hand, reduction in the size of analog circuits has been insufficient. This means that the analog circuit area is relatively large, and reducing analog circuit area can be effective to make a low cost radio receiver. In this paper, a new wireless receiver architecture that occupies small analog area is proposed, and measured results of the core analog blocks are described. To reduce the analog area, a balanced 3-phase analog system is adopted and the functions of analog baseband filters and VGAs are moved to the digital domain. The test chip consists of a 3-phase downconverter and a 3-phase ADC. There is no analog baseband filter on the chip and the analog filter is assumed to be replaced with a digital filter. The downconverter and ADC occupy 0.28mm2. The measured results show the possibility that the requirements for IMT-2000 are fulfilled even with a small chip area.

  17. Received Signal Strength Database Interpolation by Kriging for a Wi-Fi Indoor Positioning System

    Directory of Open Access Journals (Sweden)

    Shau-Shiun Jan


    Full Text Available The main approach for a Wi-Fi indoor positioning system is based on the received signal strength (RSS measurements, and the fingerprinting method is utilized to determine the user position by matching the RSS values with the pre-surveyed RSS database. To build a RSS fingerprint database is essential for an RSS based indoor positioning system, and building such a RSS fingerprint database requires lots of time and effort. As the range of the indoor environment becomes larger, labor is increased. To provide better indoor positioning services and to reduce the labor required for the establishment of the positioning system at the same time, an indoor positioning system with an appropriate spatial interpolation method is needed. In addition, the advantage of the RSS approach is that the signal strength decays as the transmission distance increases, and this signal propagation characteristic is applied to an interpolated database with the Kriging algorithm in this paper. Using the distribution of reference points (RPs at measured points, the signal propagation model of the Wi-Fi access point (AP in the building can be built and expressed as a function. The function, as the spatial structure of the environment, can create the RSS database quickly in different indoor environments. Thus, in this paper, a Wi-Fi indoor positioning system based on the Kriging fingerprinting method is developed. As shown in the experiment results, with a 72.2% probability, the error of the extended RSS database with Kriging is less than 3 dBm compared to the surveyed RSS database. Importantly, the positioning error of the developed Wi-Fi indoor positioning system with Kriging is reduced by 17.9% in average than that without Kriging.

  18. Received Signal Strength Database Interpolation by Kriging for a Wi-Fi Indoor Positioning System. (United States)

    Jan, Shau-Shiun; Yeh, Shuo-Ju; Liu, Ya-Wen


    The main approach for a Wi-Fi indoor positioning system is based on the received signal strength (RSS) measurements, and the fingerprinting method is utilized to determine the user position by matching the RSS values with the pre-surveyed RSS database. To build a RSS fingerprint database is essential for an RSS based indoor positioning system, and building such a RSS fingerprint database requires lots of time and effort. As the range of the indoor environment becomes larger, labor is increased. To provide better indoor positioning services and to reduce the labor required for the establishment of the positioning system at the same time, an indoor positioning system with an appropriate spatial interpolation method is needed. In addition, the advantage of the RSS approach is that the signal strength decays as the transmission distance increases, and this signal propagation characteristic is applied to an interpolated database with the Kriging algorithm in this paper. Using the distribution of reference points (RPs) at measured points, the signal propagation model of the Wi-Fi access point (AP) in the building can be built and expressed as a function. The function, as the spatial structure of the environment, can create the RSS database quickly in different indoor environments. Thus, in this paper, a Wi-Fi indoor positioning system based on the Kriging fingerprinting method is developed. As shown in the experiment results, with a 72.2% probability, the error of the extended RSS database with Kriging is less than 3 dBm compared to the surveyed RSS database. Importantly, the positioning error of the developed Wi-Fi indoor positioning system with Kriging is reduced by 17.9% in average than that without Kriging.

  19. Instrumental technique in X-ray astronomy (United States)

    Peterson, L. E.


    A detailed review of the development of instruments for X-ray astronomy is given with major emphasis on nonfocusing high-sensitivity counter techniques used to detect cosmic photons in the energy range between 0.20 and 300 keV. The present status of X-ray astronomy is summarized together with significant results of the Uhuru observations, and photon interactions of importance for the detection of X-rays in space are noted. The three principal devices used in X-ray astronomy (proportional, scintillation, and solid-state counters) are described in detail, data-processing systems for these devices are briefly discussed, and the statistics of nuclear counting as applied to X-ray astronomy is outlined analytically. Effects of the near-earth X-ray environment and atmospheric gamma-ray production on X-ray detection by low-orbit satellites are considered. Several contemporary instruments are described (proportional-counter systems, scintillation-counter telescopes, modulation collimators), and X-ray astronomical satellite missions are tabulated.


    Directory of Open Access Journals (Sweden)

    Gurjit Kaur


    Full Text Available In this paper a 16-bit differential phase shift keying (DPSK modulator is designed for 32 dense wavelength division multiplexing (DWDM channels. The DWDM channels are designed with 0.8nm separation in wavelength and operated at 4dBm input power. In the DWDM system, these 32 multiplexed signals propagate through a fiber length of 100 km followed by an erbium-doped fiber amplifier (EDFA inline. The channel is equipped with pre-amplifier and a dispersion compensating fiber for better performance. Also, a threshold detector is designed for both in-phase and quadrature components to detect the input amplitude and provide a quantized output amplitude level. The result shows that, a 16-bit DPSK optical signal is demodulated successfully using direct detection receiver.

  1. System design and treatment efficiency of a surface flow constructed wetland receiving runoff impacted stream water. (United States)

    Maniquiz, M C; Choi, J Y; Lee, S Y; Kang, C G; Yi, G S; Kim, L H


    This study reported the efficiency of a free water surface flow constructed wetland (CW) system that receives runoff impacted stream water from a forested and agricultural watershed. Investigations were conducted to examine the potential effect of hydraulic fluctuations on the CW as a result of storm events and the changes in water quality along the flow path of the CW. Based on the results, the incoming pollutant concentrations were increased during storm events and greater at the near end of the storm than at the initial time of storm. A similar trend was observed to the concentrations exiting the CW due to the wetland being a relatively small percentage of the watershed (time during storm events. The concentrations of most pollutants were significantly reduced (p retention of most pollutants during storm events as the actual water quality of the outflow was significantly better by 21-71% than the inflow and the levels of pollutants were reduced to appreciable levels.

  2. Indigenous Astronomies and Progress in Modern Astronomy

    CERN Document Server

    Ruggles, Clive


    From an anthropological point of view, the whole concept of a "path of progress" in astronomical discovery is anathema, since it implicitly downgrades other cultural perspectives, such as the many "indigenous cosmologies" that still exist in the modern world. By doing so, one risks provoking those who hold them and-as is most obvious in places such as Hawaii where the two "world-views" come into direct contact-reating avoidable resistance to that very progress. The problem is complicated by the existence of "fringe" and "new-age" views that are increasingly confused with, and even passed off as, indigenous perceptions. In a modern world where widespread public perceptions include many that are unscientific in the broadest sense of the term, I shall argue that there are actually a range of positive benefits for progress in scientific astronomy to be derived from the mutual awareness and comprehension of "genuine" cultural world-views whose goals-in common with those of modern science-are to make sense of the c...

  3. Mac OS X for Astronomy (United States)

    Pierfederici, F.; Pirzkal, N.; Hook, R. N.

    Mac OS X is the new Unix based version of the Macintosh operating system. It combines a high performance DisplayPDF user interface with a standard BSD UNIX subsystem and provides users with simultaneous access to a broad range of applications which were not previously available on a single system such as Microsoft Office and Adobe Photoshop, as well as legacy X11-based scientific tools and packages like IRAF, SuperMongo, MIDAS, etc. The combination of a modern GUI layered on top of a familiar UNIX environment paves the way for new, more flexible and powerful astronomical tools to be developed while assuring compatibility with already existing, older programs. In this paper, we outline the strengths of the Mac OS X platform in a scientific environment, astronomy in particular, and point to the numerous astronomical software packages available for this platform; most notably the Scisoft collection which we have compiled.

  4. Rapid stress system drives chemical transfer of fear from sender to receiver.

    Directory of Open Access Journals (Sweden)

    Jasper H B de Groot

    Full Text Available Humans can register another person's fear not only with their eyes and ears, but also with their nose. Previous research has demonstrated that exposure to body odors from fearful individuals elicited implicit fear in others. The odor of fearful individuals appears to have a distinctive signature that can be produced relatively rapidly, driven by a physiological mechanism that has remained unexplored in earlier research. The apocrine sweat glands in the armpit that are responsible for chemosignal production contain receptors for adrenalin. We therefore expected that the release of adrenalin through activation of the rapid stress response system (i.e., the sympathetic-adrenal medullary system is what drives the release of fear sweat, as opposed to activation of the slower stress response system (i.e., hypothalamus-pituitary-adrenal axis. To test this assumption, sweat was sampled while eight participants prepared for a speech. Participants had higher heart rates and produced more armpit sweat in the fast stress condition, compared to baseline and the slow stress condition. Importantly, exposure to sweat from participants in the fast stress condition induced in receivers (N = 31 a simulacrum of the state of the sender, evidenced by the emergence of a fearful facial expression (facial electromyography and vigilant behavior (i.e., faster classification of emotional facial expressions.

  5. Received Signal Strength Recovery in Green WLAN Indoor Positioning System Using Singular Value Thresholding

    Directory of Open Access Journals (Sweden)

    Lin Ma


    Full Text Available Green WLAN is a promising technique for accessing future indoor Internet services. It is designed not only for high-speed data communication purposes but also for energy efficiency. The basic strategy of green WLAN is that all the access points are not always powered on, but rather work on-demand. Though powering off idle access points does not affect data communication, a serious asymmetric matching problem will arise in a WLAN indoor positioning system due to the fact the received signal strength (RSS readings from the available access points are different in their offline and online phases. This asymmetry problem will no doubt invalidate the fingerprint algorithm used to estimate the mobile device location. Therefore, in this paper we propose a green WLAN indoor positioning system, which can recover RSS readings and achieve good localization performance based on singular value thresholding (SVT theory. By solving the nuclear norm minimization problem, SVT recovers not only the radio map, but also online RSS readings from a sparse matrix by sensing only a fraction of the RSS readings. We have implemented the method in our lab and evaluated its performances. The experimental results indicate the proposed system could recover the RSS readings and achieve good localization performance.

  6. Gas spectroscopy system with 245 GHz transmitter and receiver in SiGe BiCMOS (United States)

    Schmalz, Klaus; Rothbart, Nick; Borngräber, Johannes; Yilmaz, Selahattin Berk; Kissinger, Dietmar; Hübers, Heinz-Wilhelm


    The implementation of an integrated mm-wave transmitter (TX) and receiver (RX) in SiGe BiCMOS or CMOS technology offers a path towards a compact and low-cost system for gas spectroscopy. Previously, we have demonstrated TXs and RXs for spectroscopy at 238 -252 GHz and 495 - 497 GHz using external phase-locked loops (PLLs) with signal generators for the reference frequency ramps. Here, we present a more compact system by using two external fractional-N PLLs allowing frequency ramps for the TX and RX, and for TX with superimposed frequency shift keying (FSK) or reference frequency modulation realized by a direct digital synthesizer (DDS) or an arbitrary waveform generator. The 1.9 m folded gas absorption cell, the vacuum pumps, as well as the TX and RX are placed on a portable breadboard with dimensions of 75 cm x 45 cm. The system performance is evaluated by high-resolution absorption spectra of gaseous methanol at 13 Pa for 241 - 242 GHz. The 2f (second harmonic) content of the absorption spectrum of the methanol was obtained by detecting the IF power of RX using a diode power sensor connected to a lock-in amplifier. The reference frequency modulation reveals a higher SNR (signal-noise-ratio) of 98 within 32 s acquisition compared to 66 for FSK. The setup allows for jumping to preselected frequency regions according to the spectral signature thus reducing the acquisition time by up to one order of magnitude.

  7. Received signal strength recovery in green WLAN indoor positioning system using singular value thresholding. (United States)

    Ma, Lin; Xu, Yubin


    Green WLAN is a promising technique for accessing future indoor Internet services. It is designed not only for high-speed data communication purposes but also for energy efficiency. The basic strategy of green WLAN is that all the access points are not always powered on, but rather work on-demand. Though powering off idle access points does not affect data communication, a serious asymmetric matching problem will arise in a WLAN indoor positioning system due to the fact the received signal strength (RSS) readings from the available access points are different in their offline and online phases. This asymmetry problem will no doubt invalidate the fingerprint algorithm used to estimate the mobile device location. Therefore, in this paper we propose a green WLAN indoor positioning system, which can recover RSS readings and achieve good localization performance based on singular value thresholding (SVT) theory. By solving the nuclear norm minimization problem, SVT recovers not only the radio map, but also online RSS readings from a sparse matrix by sensing only a fraction of the RSS readings. We have implemented the method in our lab and evaluated its performances. The experimental results indicate the proposed system could recover the RSS readings and achieve good localization performance.

  8. Operator decision support system for integrated wastewater management including wastewater treatment plants and receiving water bodies. (United States)

    Kim, Minsoo; Kim, Yejin; Kim, Hyosoo; Piao, Wenhua; Kim, Changwon


    An operator decision support system (ODSS) is proposed to support operators of wastewater treatment plants (WWTPs) in making appropriate decisions. This system accounts for water quality (WQ) variations in WWTP influent and effluent and in the receiving water body (RWB). The proposed system is comprised of two diagnosis modules, three prediction modules, and a scenario-based supporting module (SSM). In the diagnosis modules, the WQs of the influent and effluent WWTP and of the RWB are assessed via multivariate analysis. Three prediction modules based on the k-nearest neighbors (k-NN) method, activated sludge model no. 2d (ASM2d) model, and QUAL2E model are used to forecast WQs for 3 days in advance. To compare various operating alternatives, SSM is applied to test various predetermined operating conditions in terms of overall oxygen transfer coefficient (Kla), waste sludge flow rate (Qw), return sludge flow rate (Qr), and internal recycle flow rate (Qir). In the case of unacceptable total phosphorus (TP), SSM provides appropriate information for the chemical treatment. The constructed ODSS was tested using data collected from Geumho River, which was the RWB, and S WWTP in Daegu City, South Korea. The results demonstrate the capability of the proposed ODSS to provide WWTP operators with more objective qualitative and quantitative assessments of WWTP and RWB WQs. Moreover, the current study shows that ODSS, using data collected from the study area, can be used to identify operational alternatives through SSM at an integrated urban wastewater management level.

  9. Intelligent Security IT System for Detecting Intruders Based on Received Signal Strength Indicators

    Directory of Open Access Journals (Sweden)

    Yunsick Sung


    Full Text Available Given that entropy-based IT technology has been applied in homes, office buildings and elsewhere for IT security systems, diverse kinds of intelligent services are currently provided. In particular, IT security systems have become more robust and varied. However, access control systems still depend on tags held by building entrants. Since tags can be obtained by intruders, an approach to counter the disadvantages of tags is required. For example, it is possible to track the movement of tags in intelligent buildings in order to detect intruders. Therefore, each tag owner can be judged by analyzing the movements of their tags. This paper proposes a security approach based on the received signal strength indicators (RSSIs of beacon-based tags to detect intruders. The normal RSSI patterns of moving entrants are obtained and analyzed. Intruders can be detected when abnormal RSSIs are measured in comparison to normal RSSI patterns. In the experiments, one normal and one abnormal scenario are defined for collecting the RSSIs of a Bluetooth-based beacon in order to validate the proposed method. When the RSSIs of both scenarios are compared to pre-collected RSSIs, the RSSIs of the abnormal scenario are about 61% more different compared to the RSSIs of the normal scenario. Therefore, intruders in buildings can be detected by considering RSSI differences.

  10. Using PlayDoh Astronomy for Understanding the Size and Scale of the Earth-Moon System and as a Probe for Spatial Translation Ability (United States)

    Grundstrom, Erika


    To help students love science more and to help them understand the vast distances that pervade astronomy, we use kinesthetic modeling of the Earth-Moon system using PlayDoh. When coupled with discussion, we found (in a pilot study) that students of all ages (children up through adults) acquired a more accurate mental representation of the Earth-Moon system. During early September 2012, we devised and implemented a curriculum unit that focused on the Earth-Moon system and how that relates to eclipses for six middle-Tennessee 6th grade public school classrooms. For this unit, we used PlayDoh as the kinesthetic modeling tool. First, we evaluated what the students knew about the size and scale prior to this intervention using paper and model pre-tests. Second, we used the PlayDoh to model the Earth-Moon system and when possible, conducted an immediate post-test. The students then engaged with the PlayDoh model to help them understand eclipses. Third, we conducted a one-month-later delayed post-test. One thing to note is that about half of the students had experienced the PlayDoh modeling part of a 5th grade pilot lesson during May 2012 therefore the pre-test acted as a four-month-later delayed post-test for these students. We find, among other things, that students retain relative size information more readily than relative distance information. We also find differences in how consistent students are when trying to translate the size/scale they have in their heads to the different modes of assessment utilized.

  11. Episodes from the Early History of Astronomy (United States)

    Aaboe, Asger

    The author does not attempt to give a general survey of early astronomy; rather, he chooses to present a few "episodes" and treats them in detail. However, first he provides the necessary astronomical background in his descriptive account of what you can see when you look at the sky with the naked eye, unblinkered by received knowledge, but with curiosity and wit. Chapter 1 deals with the arithmetical astronomy of ancient Mesopotamia where astronomy first was made an exact science. Next are treated Greek geometrical models for planetary motion, culminating in Ptolemy's equant models in his Almagest. Ptolemy does not assign them absolute size in this work, but, as is shown here, if we scale the models properly, they will yield good values, not only of the directions to the planets, but of the distances to them, as well. Thus one can immediately find the dimensions of the Copernican System from parameters in the Almagest - we have evidence that Copernicus did just that. Further, Islamic astronomers' modifications of Ptolemy's models by devices using only uniform circular motion are discussed, as are Copernicus's adoption of some of them. finally, it is made precise which bothersome problem was resolved by the heliocentric hypothesis, as it was by the Tychonic arrangement. Next, the Ptolemaic System, the first cosmological scheme to incorporate quantitative models, is described as Ptolemy himself did it in a recenlty recovered passage from his Planetary Hypotheses. Here he does assign absolute size to his models in order to fit them into the snugly nested spherical shells that made up his universe. This much maligned system was, in fact, a harmonious construct that remained the basis for how educated people thought of their world for a millennium and a half. Finally, after a brief review of the geometry of the ellipse, the author gives an elementary derivation of Kepler's equation, and shows how Kepler solved it, and further proves that a planet moves very nearly

  12. Astronomy Education for Physics Students (United States)

    Fan, J. H.; Zhang, J. S.; Zhang, J. Y.; Liu, Y.; Wang, H. G.


    Astronomy is a very interesting subject for undergraduate students studying physics. In this paper, we report astronomy education for undergraduate students in the Physics Department of Guangzhou University, and how we are teaching astronomy to the students. Astrophysics has been rapidly developing since 1994, when the center for astrophysics was founded. Now, astrophysics has become a key subject in Guangdong Province, and the Astronomy Science and Technology Research Laboratory one of the key laboratories of the Department of Education of the Guangdong Province. Many undergraduate students, working under the tutorship of faculty members completed their thesis at the Center for Astrophysics in Guangzhou.

  13. Accessible Universe: Making Astronomy Accessible to All in the Regular Elementary Classroom (United States)

    Grady, C. A.; Farley, N.; Zamboni, E.; Avery, F.; Clark, B.; Geiger, N.; Woodgate, B.

    Astronomy is one of the most approachable of the sciences and enjoys tremendous popular interest, beginning at the elementary level and continuing on through college and in the popular media. Space-related topics are some of the most popular science topics in the elementary grades and can serve as a springboard to other sciences, mathematics, technology, and reading for the typical student. Not all students are typical: 10% of American students are identified as having disabilities affecting their education sufficiently that they receive special education services, with perhaps an additional 10% less severely affected. At the elementary level, these students usually receive their science education in comprehensive (mixed-ability) classrooms. Budgetary limitations for most school systems have meant that, for the bulk of these children, individualized accommodations and adaptations for science instruction are not readily available. We have piloted a suite of curriculum materials, modified activities, and instructional strategies, incorporating both Web-based astronomy resources and assistive technology to more effectively teach astronomy to children with disabilities in the elementary regular education classroom.

  14. Summary: Special Session SpS15: Data Intensive Astronomy (United States)

    Montmerle, Thierry


    A new paradigm in astronomical research has been emerging - ``Data Intensive Astronomy'' that utilizes large amounts of data combined with statistical data analyses. The first research method in astronomy was observations by our eyes. It is well known that the invention of telescope impacted the human view on our Universe (although it was almost limited to the solar system), and lead to Keplerfs law that was later used by Newton to derive his mechanics. Newtonian mechanics then enabled astronomers to provide the theoretical explanation to the motion of the planets. Thus astronomers obtained the second paradigm, theoretical astronomy. Astronomers succeeded to apply various laws of physics to reconcile phenomena in the Universe; e.g., nuclear fusion was found to be the energy source of a star. Theoretical astronomy has been paired with observational astronomy to better understand the background physics in observed phenomena in the Universe. Although theoretical astronomy succeeded to provide good physical explanations qualitatively, it was not easy to have quantitative agreements with observations in the Universe. Since the invention of high-performance computers, however, astronomers succeeded to have the third research method, simulations, to get better agreements with observations. Simulation astronomy developed so rapidly along with the development of computer hardware (CPUs, GPUs, memories, storage systems, networks, and others) and simulation codes.

  15. Transmission of Babylonian Astronomy to Other Cultures (United States)

    Jones, Alexander

    Babylonian astronomy and astrology were extensively transmitted to other civilizations in the second and first millennia BC. Greek astronomy in particular was largely shaped by knowledge of Babylonian observations and mathematical astronomy.

  16. New readout and data-acquisition system in an electron-tracking Compton camera for MeV gamma-ray astronomy (SMILE-II)

    Energy Technology Data Exchange (ETDEWEB)

    Mizumoto, T., E-mail: [Department of Physics, Kyoto University, 606-8502 Kyoto (Japan); Matsuoka, Y. [Department of Physics, Kyoto University, 606-8502 Kyoto (Japan); Mizumura, Y. [Unit of Synergetic Studies for Space, Kyoto University, 606-8502 Kyoto (Japan); Department of Physics, Kyoto University, 606-8502 Kyoto (Japan); Tanimori, T. [Department of Physics, Kyoto University, 606-8502 Kyoto (Japan); Unit of Synergetic Studies for Space, Kyoto University, 606-8502 Kyoto (Japan); Kubo, H.; Takada, A.; Iwaki, S.; Sawano, T.; Nakamura, K.; Komura, S.; Nakamura, S.; Kishimoto, T.; Oda, M.; Miyamoto, S.; Takemura, T.; Parker, J.D.; Tomono, D.; Sonoda, S. [Department of Physics, Kyoto University, 606-8502 Kyoto (Japan); Miuchi, K. [Department of Physics, Kobe University, 658-8501 Kobe (Japan); Kurosawa, S. [Institute for Materials Research, Tohoku University, 980-8577 Sendai (Japan)


    For MeV gamma-ray astronomy, we have developed an electron-tracking Compton camera (ETCC) as a MeV gamma-ray telescope capable of rejecting the radiation background and attaining the high sensitivity of near 1 mCrab in space. Our ETCC comprises a gaseous time-projection chamber (TPC) with a micro pattern gas detector for tracking recoil electrons and a position-sensitive scintillation camera for detecting scattered gamma rays. After the success of a first balloon experiment in 2006 with a small ETCC (using a 10×10×15 cm{sup 3} TPC) for measuring diffuse cosmic and atmospheric sub-MeV gamma rays (Sub-MeV gamma-ray Imaging Loaded-on-balloon Experiment I; SMILE-I), a (30 cm){sup 3} medium-sized ETCC was developed to measure MeV gamma-ray spectra from celestial sources, such as the Crab Nebula, with single-day balloon flights (SMILE-II). To achieve this goal, a 100-times-larger detection area compared with that of SMILE-I is required without changing the weight or power consumption of the detector system. In addition, the event rate is also expected to dramatically increase during observation. Here, we describe both the concept and the performance of the new data-acquisition system with this (30 cm){sup 3} ETCC to manage 100 times more data while satisfying the severe restrictions regarding the weight and power consumption imposed by a balloon-borne observation. In particular, to improve the detection efficiency of the fine tracks in the TPC from ~10% to ~100%, we introduce a new data-handling algorithm in the TPC. Therefore, for efficient management of such large amounts of data, we developed a data-acquisition system with parallel data flow.

  17. Receiver Design, Performance Analysis, and Evaluation for Space-Borne Laser Altimeters and Space-to-Space Laser Ranging Systems (United States)

    Davidson, Frederic M.; Sun, Xiaoli; Field, Christopher T.


    This progress report consists of two separate reports. The first one describes our work on the use of variable gain amplifiers to increase the receiver dynamic range of space borne laser altimeters such as NASA's Geoscience Laser Altimeter Systems (GLAS). The requirement of the receiver dynamic range was first calculated. A breadboard variable gain amplifier circuit was made and the performance was fully characterized. The circuit will also be tested in flight on board the Shuttle Laser Altimeter (SLA-02) next year. The second report describes our research on the master clock oscillator frequency calibration for space borne laser altimeter systems using global positioning system (GPS) receivers.

  18. 30 CFR 75.704 - Grounding frames of stationary high-voltage equipment receiving power from ungrounded delta systems. (United States)


    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Grounding frames of stationary high-voltage equipment receiving power from ungrounded delta systems. 75.704 Section 75.704 Mineral Resources MINE SAFETY...-UNDERGROUND COAL MINES Grounding § 75.704 Grounding frames of stationary high-voltage equipment receiving...

  19. All-optical OFDM system using a wavelength selective switch based transmitter and a spectral magnification based receiver

    DEFF Research Database (Denmark)

    Guan, Pengyu; Lefrancois, S.; Lillieholm, Mads


    We demonstrate an AO-OFDM system with a WSS-based transmitter and time-lens based receiver for spectral magnification, achieving BER~10-9 for a 28×10 Gbit/s DPSK AO-OFDM signal. Furthermore, the receiver performance for DPSK and DQPSK is investigated using Monte Carlo simulations....

  20. The Revision of UDC 52 and of the Astronomy Thesaurus (United States)

    Wilkins, George A.

    There is an urgent need for the revision of the Universal Decimal Classification for Astronomy (in class 52) for use in libraries and information retrieval systems. The author has drafted a revised and much extended schedule for UDC 52 with the aim of making it compatible with The Astronomy Thesaurus, which now also needs updating. Further assistance from astronomers and astronomy librarians is, however, required if the revision of UDC 52 and the corresponding updating of the Thesaurus is to be completed satisfactorily without further undue delay.

  1. Astronomy across cultures the history of non-Western astronomy

    CERN Document Server

    Xiaochun, Sun


    Astronomy Across Cultures: A History of Non-Western Astronomy consists of essays dealing with the astronomical knowledge and beliefs of cultures outside the United States and Europe. In addition to articles surveying Islamic, Chinese, Native American, Aboriginal Australian, Polynesian, Egyptian and Tibetan astronomy, among others, the book includes essays on Sky Tales and Why We Tell Them and Astronomy and Prehistory, and Astronomy and Astrology. The essays address the connections between science and culture and relate astronomical practices to the cultures which produced them. Each essay is well illustrated and contains an extensive bibliography. Because the geographic range is global, the book fills a gap in both the history of science and in cultural studies. It should find a place on the bookshelves of advanced undergraduate students, graduate students, and scholars, as well as in libraries serving those groups.

  2. Dyslexia and Astronomy (United States)

    Schneps, Matthew H.; Greenhill, L. J.; Rose, L. T.


    Dyslexia is a hereditary neurological disability that impairs reading. It is believed that anywhere from 5% to 20% of all people in the US may have dyslexia to a greater or lesser degree. Though dyslexia is common, it is a "silent disability" in the sense that it is not easy to tell which individuals suffer from dyslexia and which do not. There is a substantial body of evidence to suggest that people with dyslexia tend to do well in science. For example, Baruj Benacerraf, a Nobel laureate in medicine, is among those whose impairments have been documented and studied. Given that dyslexia was not diagnosed in schools prior to the late 1970's, many established science researchers may have dyslexia and be unaware of their impairment. Therefore, it would not be surprising to find that substantial numbers of scientists working in the fields of astronomy and astrophysics have dyslexia, and yet be unaware of the effects this disability has had on their research. A recently proposed theory by the authors suggests that there may be specific neurological reasons why those with dyslexia may be predisposed to science, and predicts that dyslexia may be associated with enhanced abilities for certain types of visual processing, with special implications for image processing. Our study, funded by the NSF, investigates this hypothesis in the context of astronomy and astrophysics. We expect this work will uncover and document challenges faced by scientists with dyslexia, but perhaps more importantly, lead to an understanding of the strengths these scientists bring to research. The program will serve as a clearing-house of information for scientists and students with dyslexia, and begin to provide mentoring for young people with dyslexia interested in astronomy. Scientists who have reason to believe they may have dyslexia are encouraged to contact the authors.

  3. Academic Training: Astronomy from Space

    CERN Multimedia

    Françoise Benz


    2004-2005 ACADEMIC TRAINING PROGRAMME LECTURE SERIES 14, 15, 16, 18 March from 11.00 to 12.00 hrs - Main Auditorium, bldg. 500 Astronomy from Space by T. Courvoisier / Observatoire de Genève In the very wide field of High Energy astrophysics we will select a number of topics that range from the source of radiative energy in the deep potential well around Schwarzschild and Kerr black holes and the basics of accretion disks around compact objects to the description and (where possible) the understanding of binary systems including a compact object (neutron star or black hole), of Active Galactic Nuclei and of gamma ray bursts. The approach that is chosen aims at giving an understanding of the most important phenomenologies encountered in high energy astrophysics rather than a detailed knowledge of one specific topic. ENSEIGNEMENT ACADEMIQUE ACADEMIC TRAINING Françoise Benz 73127

  4. Gamma-ray Astronomy


    Pohl, Martin


    This paper summarizes recents results in gamma-ray astronomy, most of which were derived with data from ground-based gamma-ray detectors. Many of the contributions presented at this conference involve multiwavelength studies which combine ground-based gamma-ray measurements with optical data or space-based X-ray and gamma-ray measurements. Besides measurements of the diffuse emission from the Galaxy, observations of blazars, gamma-ray bursts, and supernova remnants this paper also covers theo...

  5. Superluminal motion in astronomy

    Energy Technology Data Exchange (ETDEWEB)

    Falla, D.F.; Floyd, M.J. [Department of Physics, University of Wales, Aberystwyth (United Kingdom)


    Several examples of 'intrinsic-type' superluminal motion in astronomy are taken. A simple signal-delay transformation is devised and shown to be sufficient to explain the superluminal effect as resulting from differential signal delay across an expanding source. The distinction between relativistic motion and relativistic kinematics is made. The key kinematical equation used to describe superluminal motion is an alternative statement of the Doppler effect. Relativistic transformations, which are relevant when intervals in different reference frames are compared, then lead to the relativistic Doppler factor ({delta}), which is applicable to measurements on a photographic image, for example that of a relativistic quasar jet with superluminal components. (author)

  6. Astronomy in Iran (United States)

    Sobouti, Y.


    Institute for Advanced Studies in Basic Sciences, Zanjan, Iran In spite of her renowned pivotal role in the advancement of astronomy on the world scale during 9th to 15th centuries, Iran's rekindled interest in modern astronomy is a recent happening. Serious attempts to introduce astronomy into university curricula and to develop it into a respectable and worthwhile field of research began in the mid 60's. The pioneer was Shiraz University. It should be credited for the first few dozens of astronomy- and astrophysics- related research papers in international journals, for training the first half a dozen of professional astronomers and for creating the Biruni Observatory. Here, I take this opportunity to acknowledge the valuable advice of Bob Koch and Ed Guinan, then of the University of Pennsylvania, in the course of the establishment of this observatory. At present the astronomical community of Iran consists of about 65 professionals, half university faculty members and half MS and PhD students. The yearly scientific contribution of its members has, in the past three years, averaged to about 15 papers in reputable international journals, and presently has a healthy growth rate. Among the existing observational facilities, Biruni Observatory with its 51 cm Cassegrain, CCD cameras, photometers and other smaller educational telescopes, is by far the most active place. Tusi Observatory of Tabriz University has 60 and 40 cm Cassegrains, and a small solar telescope. A number of smaller observing facilities exist in Meshed, Zanjan, Tehran, Babol and other places. The Astronomical Society of Iran (ASI), though some 30 years old, has expanded and institutionalized its activities since early 1990's. ASI sets up seasonal schools for novices, organizes annual colloquia and seminars for professionals and supports a huge body of amateur astronomers from among high school and university students. Over twenty of ASI members are also members of IAU and take active part in its

  7. Multimessenger Astronomy with Neutrinos (United States)

    Franckowiak, Anna


    The recent discovery of high-energy astrophysical neutrinos has opened a new window to the Universe. However, the sources of those neutrinos are still unknown. Among the plausible candidates are gamma-ray bursts, active galactic nuclei and supernovae. Combining neutrino data with electromagnetic measurements in a multimessenger approach will increase our ability to identify the neutrino sources and help to solve long-standing problems in astrophysics such as the origin of cosmic rays. Neutrino observations may also contribute to future detections of gravitational wave signals, and enable the study of their source progenitors. I will review the recent progress in multimessenger astronomy using neutrino data.

  8. Gravitational-Wave Astronomy (United States)

    Kelly, Bernard J.


    Einstein's General Theory of Relativity is our best classical description of gravity, and informs modern astronomy and astrophysics at all scales: stellar, galactic, and cosmological. Among its surprising predictions is the existence of gravitational waves -- ripples in space-time that carry energy and momentum away from strongly interacting gravitating sources. In my talk, I will give an overview of the properties of this radiation, recent breakthroughs in computational physics allowing us to calculate the waveforms from galactic mergers, and the prospect of direct observation with interferometric detectors such as LIGO and LISA.

  9. Islamic Mathematical Astronomy (United States)

    Montelle, Clemency

    A short survey on Islamic mathematical astronomy practiced during the period running from the eight century until the fifteenth is presented. Various pertinent themes, such as the translation of foreign scientific works and their impact on the tradition; the introduction, assimilation, and critique of the Ptolemaic model; and the role of observations, will be covered. In addition, the zīj, the dominant format for astronomical works, will be briefly explained as well as the legacy of the Islamic tradition of astral sciences to other cultures.

  10. ACDA Thirty Years of Popularization of Astronomy in Colombia (United States)

    Ocampo, W.; Higuera-G., Mario A.


    The Colombian Association of Astronomical Studies (ACDA) is a Non Profit Organization with thirty years of permanent efforts for the popularization of astronomy and related sciences in Colombia. ACDA put together amateur and profesional astronomers, as well as interested people. We surely had left a footprint on uncountable number of attending people to our activities, members and former members, and have supported the process of building a new society, with more awareness on the importance of science. We devote our efforts to our members and general people, to keep them motivated, support them and follow each member own interests in order to expand and spread their knowledge. In order to achieve our goals we have develop several strategies as: acquire of didactic material and optical instruments, video projections and discussion, astronomical observations, visits to observatories and planetariums, attending conferences and events, and mainly a weekly Saturday morning talk at the Bogotá Planetarium. ACDA has had different study teams on several fields including: Planetary Systems, Astrobiology, Space Exploration, Cosmology, History of Astronomy and Radioastronomy. ACDA has a national brandname on Astronomy due to seriousness and quality of its projects. A good list of members have become profesional astronomers. From our experience we can say: astronomy is a fertile field to teach science, in general there is an absence of astronomy culture in the public, our best communication experience are astronomical observations, explained astronomy movies and colloquiums, our best public are kids and aged people and finally, social networks gave dynamics to our astronomy spreading initiative.

  11. Astronomie spatiale infrarouge, aujourd’hui et demain = Infrared space astronomy, today and tomorrow

    CERN Document Server

    Lequeux, J; David, F


    This book brings together the lectures given at the Les Houches summer school "Infrared space astronomy, today and tomorrow". It gives a wide overview of infrared astronomy, a wavelength domain crucial for studies of the solar system, stars at the beginning and end of their lives, interstellar matter and galaxies at all distances. Recent developments in observational techniques have been tremendous. The first contributions give an introduction to the basic physical processes and methods of detection and data processing. They are followed by a series of lectures dealing with the wide variety of astronomical objects that can be seen in the infrared.

  12. Science and Mathematics in Astronomy (United States)

    Woolack, Edward


    A brief historical introduction to the development of observational astronomy will be presented. The close historical relationship between the successful application of mathematical concepts and advances in astronomy will be presented. A variety of simple physical demonstrations, hands-on group activities, and puzzles will be used to understand how the properties of light can be used to understand the contents of our universe.

  13. Design and modelling of novel evacuated receiver tube of concentration solar power system by using heliostat stadium arrangement

    Directory of Open Access Journals (Sweden)

    Kadhim Khlief Ayad


    Full Text Available A novel concentration solar evacuated receiver tube collector is proposed in this study. Details of design and simulation of the heliostat field are presented. The proposed system uses a heliostat stadium arrangement to focus sunlight towards a receiver (evacuated receiver tube. Heliostat field which looks like stadium arrangement is proposed an alternative system of the tower in the power tower plants to cancel the shading / blocking losses. In this study, simulation results showed that the energy input increases with increased solar irradiation; the increase ranges from 288 to 470W/m.The maximum amount of energy inputs that can be obtained in the receiver for the collector is around 470W/m for the maximum solar density of 688W.m2. In the solar is 402 W/m2, and the useful energy of collectors is about 288 W/m and the thermal efficiency of the receiver was around 23%.

  14. Compressed sensing techniques for receiver based post-compensation of transmitter's nonlinear distortions in OFDM systems

    KAUST Repository

    Owodunni, Damilola S.


    In this paper, compressed sensing techniques are proposed to linearize commercial power amplifiers driven by orthogonal frequency division multiplexing signals. The nonlinear distortion is considered as a sparse phenomenon in the time-domain, and three compressed sensing based algorithms are presented to estimate and compensate for these distortions at the receiver using a few and, at times, even no frequency-domain free carriers (i.e. pilot carriers). The first technique is a conventional compressed sensing approach, while the second incorporates a priori information about the distortions to enhance the estimation. Finally, the third technique involves an iterative data-aided algorithm that does not require any pilot carriers and hence allows the system to work at maximum bandwidth efficiency. The performances of all the proposed techniques are evaluated on a commercial power amplifier and compared. The error vector magnitude and symbol error rate results show the ability of compressed sensing to compensate for the amplifier\\'s nonlinear distortions. © 2013 Elsevier B.V.

  15. PCI Based Read-out Receiver Card in the ALICE DAQ System

    CERN Document Server

    Carena, W; Dénes, E; Divià, R; Schossmaier, K; Soós, C; Sulyán, J; Vascotto, Alessandro; Van de Vyvre, P


    The Detector Data Link (DDL) is the high-speed optical link for the ALICE experiment. This link shall transfer the data coming from the detectors at 100 MB/s rate. The main components of the link have been developed: the destination Interface Unit (DIU), the Source Interface Unit (SIU) and the Read-out Receiver Card (RORC). The first RORC version is based on the VME bus. The performance tests show that the maximum VME bandwidth could be reached. Meanwhile the PCI bus became very popular and is used in many platforms. The development of a PCI-based version has been started. The document describes the prototype version in three sections. An overview explains the main purpose of the card: to provide an interface between the DDL and the PCI bus. Acting as a 32bit/33MHz PCI master the card is able to write or read directly to or from the system memory from or to the DDL, respectively. Beside these functions the card can also be used as an autonomous data generator. The card has been designed to be well adapted to ...

  16. Gravity field error analysis - Applications of Global Positioning System receivers and gradiometers on low orbiting platforms (United States)

    Schrama, Ernst J. O.


    The concept of a Global Positioning System (GPS) receiver as a tracking facility and a gradiometer as a separate instrument on a low-orbiting platform offers a unique tool to map the earth's gravitational field with unprecedented accuracies. The former technique allows determination of the spacecraft's ephemeris at any epoch to within 3-10 cm, the latter permits the measurement of the tensor of second order derivatives of the gravity field to within 0.01 to 0.0001 Eotvos units depending on the type of gradiometer. First, a variety of error sources in gradiometry where emphasis is placed on the rotational problem pursuing as well a static as a dynamic approach is described. Next, an analytical technique is described and applied for an error analysis of gravity field parameters from gradiometer and GPS observation types. Results are discussed for various configurations proposed on Topex/Poseidon, Gravity Probe-B, and Aristoteles, indicating that GPS only solutions may be computed up to degree and order 35, 55, and 85, respectively, whereas a combined GPS/gradiometer experiment on Aristoteles may result in an acceptable solution up to degree and order 240.

  17. An Optical Receiver Post Processing System for the Integrated Radio and Optical Communications Software Defined Radio Test Bed (United States)

    Nappier, Jennifer M.; Tokars, Roger P.; Wroblewski, Adam C.


    The Integrated Radio and Optical Communications (iROC) project at the National Aeronautics and Space Administrations (NASA) Glenn Research Center is investigating the feasibility of a hybrid radio frequency (RF) and optical communication system for future deep space missions. As a part of this investigation, a test bed for a radio frequency (RF) and optical software defined radio (SDR) has been built. Receivers and modems for the NASA deep space optical waveform are not commercially available so a custom ground optical receiver system has been built. This paper documents the ground optical receiver, which is used in order to test the RF and optical SDR in a free space optical communications link.

  18. An Optical Receiver Post-Processing System for the Integrated Radio and Optical Communications Software Defined Radio Test Bed (United States)

    Nappier, Jennifer M.; Tokars, Roger P.; Wroblewski, Adam C.


    The Integrated Radio and Optical Communications (iROC) project at the National Aeronautics and Space Administration's (NASA) Glenn Research Center is investigating the feasibility of a hybrid radio frequency (RF) and optical communication system for future deep space missions. As a part of this investigation, a test bed for a radio frequency (RF) and optical software defined radio (SDR) has been built. Receivers and modems for the NASA deep space optical waveform are not commercially available so a custom ground optical receiver system has been built. This paper documents the ground optical receiver, which is used in order to test the RF and optical SDR in a free space optical communications link.

  19. Acceptance test report, 241-SY-101 Flexible Receiver System, Phase 2 testing

    Energy Technology Data Exchange (ETDEWEB)

    Ritter, G.A.


    This document summarizes the results of the Phase 2 acceptance test of the 241-SY-101 Flexible Receiver System (FRS). The FRS is one of six major components of the Equipment Removal System, which has been designed to retrieve, transport, and store the test mixer pump currently installed in Tank 241-SY-101. The purpose of this acceptance test is to verify the strength of the containment bag and bag bottom cinching mechanism. It is postulated that 68 gallons of waste could be trapped inside the pump internals. The bag must be capable of supporting this waste if it shakes loose and drains to the bottom of the bag after the bag bottom has been cinched closed. This acceptance test was performed at the Maintenance and Storage Facility (MASF) Facility in the 400 area on January 23, 1995. The bag assembly supported the weight of 920 kg (2,020 lbs) of water with no leakage or damage to the bag. This value meets the acceptance criteria of 910 kg of water and therefore the results were found to be acceptable. The maximum volume of liquid expected to be held up in the pump internals is 258 L (68 gallons), which corresponds to 410 kg. This test weight gives just over a safety factor of 2. The bag also supported a small shock load while it was filled with water when the crane hoisted the bag assembly up and down. Based on the strength rating of the bag components, the bag assembly should support 2--3 times the test weight of 910 kg.

  20. Reflux heat-pipe solar receiver for a Stirling dish-electric system (United States)

    Ziph, B.; Godett, T. M.; Diver, R. B.

    This paper describes the preliminary design of a reflux heat-pipe solar receiver to match the STM4-120 variable swashplate Stirling engine to a test bed concentrator at Sandia National Laboratories Distributed Receiver Test Facility. Performance analysis and other design considerations are presented and discussed.

  1. Classics in radio astronomy

    CERN Document Server

    Sullivan, Woodruff Turner


    Radio techniques were the nrst to lead astronomy away from the quiescent and limited Universe revealed by traditional observations at optical wave­ lengths. In the earliest days of radio astronomy, a handful of radio physicists and engineers made one startling discovery after another as they opened up the radio sky. With this collection of classic papers and the extensive intro­ ductory material, the reader can experience these exciting discoveries, as well as understand the developing techniques and follow the motivations which prompted the various lines of inquiry. For instance he or she will follow in detail the several attempts to detect radio waves from the sun at the turn of the century; the unravelling by Jansky of a "steady hiss type static"; the incredible story of Reber who built a 9 meter dish in his backyard in 1937 and then mapped the Milky Way; the vital discoveries by Hey and colleagues of radio bursts from the Sun and of a discrete source in the constellation of Cygnus; the development of re...

  2. Active Astronomy Roadshow Haiti (United States)

    Laycock, Silas; Oram, Kathleen; Alabre, Dayana; Douyon, Ralph; UMass Lowell Haiti Development Studies Center


    College-age Haitian students working with advisors and volunteers from UMass Lowell in 2015 developed and tested an activity-based K-8 curriculum in astronomy, space, and earth science. Our partner school is located in Les Cayes, Haiti a city where only 65% of children attend school, and only half of those will complete 6th grade. Astronomy provides an accessible and non-intimidating entry into science, and activity-based learning contrasts with the predominant traditional teaching techniques in use in Haiti, to reach and inspire a different cohort of learners. Teachers are predominantly women in Haiti, so part of the effort involves connecting them with scientists, engineers and teacher peers in the US. As a developing nation, it is vital for Haitian (as for all) children to grow up viewing women as leaders in science. Meanwhile in the US, few are aware of the reality of getting an education in a 3rd world nation (i.e. most of the world), so we also joined with teachers in Massachusetts to give US school children a peek at what daily life is like for their peers living in our vibrant but impoverished neighbor. Our Haitian partners are committed to helping their sister-schools with curriculum and educator workshops, so that the overall quality of education can rise, and not be limited to the very few schools with access to resources. We will describe the activites, motivation, and and the lessons learned from our first year of the project.

  3. Making Astronomy Accessible (United States)

    Grice, Noreen A.


    A new semester begins, and your students enter the classroom for the first time. You notice a student sitting in a wheelchair or walking with assistance from a cane. Maybe you see a student with a guide dog or carrying a Braille computer. Another student gestures "hello” but then continues hand motions, and you realize the person is actually signing. You wonder why another student is using an electronic device to speak. Think this can't happen in your class? According to the U.S. Census, one out of every five Americans has a disability. And some disabilities, such as autism, dyslexia and arthritis, are considered "invisible” disabilities. This means you have a high probability that one of your students will have a disability. As an astronomy instructor, you have the opportunity to reach a wide variety of learners by using creative teaching strategies. I will share some suggestions on how to make astronomy and your part of the universe more accessible for everyone.

  4. Ancient Astronomy in Armenia (United States)

    Parsamian, Elma S.


    The most important discovery, which enriched our knowledge of ancient astronomy in Armenia, was the complex of platforms for astronomical observations on the Small Hill of Metzamor, which may be called an ancient “observatory”. Investigations on that Hill show that the ancient inhabitants of the Armenian Highlands have left us not only pictures of celestial bodies, but a very ancient complex of platforms for observing the sky. Among the ancient monuments in Armenia there is a megalithic monument, probably, being connected with astronomy. 250km South-East of Yerevan there is a structure Zorats Kar (Karahunge) dating back to II millennium B.C. Vertical megaliths many of which are more than two meters high form stone rings resembling ancient stone monuments - henges in Great Britain and Brittany. Medieval observations of comets and novas by data in ancient Armenian manuscripts are found. In the collection of ancient Armenian manuscripts (Matenadaran) in Yerevan there are many manuscripts with information about observations of astronomical events as: solar and lunar eclipses, comets and novas, bolides and meteorites etc. in medieval Armenia.

  5. Astronomy. Inspiration. Art (United States)

    Stanic, N.


    This paper speculates how poetry and other kind of arts are tightly related to astronomy. Hence the connection between art and natural sciences in general will be discussed in the frame of ongoing multidisciplinary project `Astronomy. Inspiration. Art' at Public Observatory in Belgrade (started in 2004). This project tends to inspire (better to say `infect') artist with a cosmic themes and fantastic sceneries of the Universe. At the very beginning of the project, Serbian poet and philosopher Laza Lazić (who published 49 books of poetry, stories and novels), as well as writer Gordana Maletić (with 25 published novels for children) were interested to work on The Inspiration by Astronomical Phenomena in Serbian Literature. Five young artists and scientists include their new ideas and new approach to multidisciplinary studies too (Srdjan Djukić, Nenad Jeremić, Olivera Obradović, Romana Vujasinović, Elena Dimoski). Two books that will be presented in details in the frame of this Project, "STARRY CITIES" ( and "ASTROLIES", don't offer only interesting illustrations, images from the latest astronomical observations and currently accepted cosmological theories -- those books induces, provoking curiosity in a specific and witty way, an adventure and challenge to explore and create.

  6. Astronomy Education in Greece (United States)

    Metaxa, M.

    Basic education is fundamental to higher education and scientific and technological literacy. We can confront the widespread adult ignorance and apathy about science and technology. Astronomy, an interdisciplinary science, enhances students' interest and overcomes educational problems. Three years ago, we developed astronomy education in these ways: 1. Summer School for School Students. (50 students from Athens came to the first Summer School in Astrophysics at the National Observatory, September 2-5, 1996, for lectures by professional astronomers and to be familiarized with observatory instruments. 2. Introducing Students to Research. (This teaches students more about science so they are more confident about it. Our students have won top prizes in European research contests for their studies of objects on Schmidt plates and computations on PCs.) 3. Hands-on Activities. (Very important because they bring students close to their natural environment. Activities are: variable-star observations (AAVSO), Eratosthenes project, solar-eclipse, sunspot and comet studies. 4. Contact with Professional Astronomers and Institutes. (These help students reach their social environment and motivate them as "science carriers". We try to make contacts at astronomical events, and through visits to appropriate institutions.) 5. Internet Programs. (Students learn about and familiarize themselves with their technological environment.) 6. Laboratory exercises. (Students should do science, not just learn about it We introduced the following lab. exercises: supernova remnants, galaxy classification, both from Schmidt plates, celestial sphere.

  7. 2011 Astronomy Day at McDonald Observatory (United States)

    Preston, Sandra; Hemeway, M.; Wetzel, M.


    Our philosophy is that everyday is Astronomy Day because the McDonald Observatory's Frank N. Bash Visitors Center is open 362 days a year. So, how did we create a special celebration for the "Astronomy Day” declared by the Astronomical League? During September 26-29 we conducted 20 videoconferences and served 12,559 students with "Astronomy Day” programming. Connect2Texas provides bridging for a network of Texas-based museums and cultural, historical, and scientific organizations that offer educational content to schools throughout the state via videoconferencing. Connect2Texas connected McDonald Observatory to 334 schools; most of these schools were in Texas, but schools in a dozen other states also participated. While most schools had a "view-only" connection, at least 20 of the schools had interactive connections, whereby the students could ask questions of the presenter. Connect2Texas also collects evaluation information from the participating schools that we will use to produce a report for our funders and make modifications to future programs as need be. The videoconferences were offered free of charge. The theme for the 2011 Astronomy Day program was the Year of the Solar System, which aligns with NASA's theme for 2011 and 2012. By aligning with this NASA theme, we could leverage NASA artwork and materials to both advertise and enrich the learning experience. Videoconference materials also included pre- and post-videoconference assessment sheets, an inquiry based activity, and pre- and post-videoconference activities, all of which were made available online. One of the lessons learned from past Astronomy Day videoconferences is that the days the Astronomical League declares as "Astronomy Day” are not always good days for Texas schools to participate. So, we choose an Astronomy Day that meets the needs of Texas schools and our schedule - so any day can be Astronomy Day. 2011 Astronomy Day was made possible by The Meyer-Levy Charitable Trust.

  8. Fatigue life analysis of cracked gas receiver of emergency cut-off system in gas gathering station (United States)

    Hu, Junzhi; Zhou, Jiyong; Li, Siyuan


    Small-scale air compressor and gas receiver are used as the driving gas of the emergency cut-off system in gas gathering station. Operation of block valve is ensured by starting and stopping compressor automatically. The frequent start-stop of compressor and the pressure fluctuation pose a threat to the service life of gas receiver, and then affect normal operation of the emergency cut-off system and security of gas gathering station. In this paper, the fatigue life of a pressure vessel with axial semi-elliptical surface crack in the inner wall is analyzed under the varying pressure by means of the theory of fracture mechanics. The influences of the amplitude of pressure fluctuation and the initial crack size on the residual life of gas receiver are discussed. It provides a basis for setting the working parameters of gas receiver of emergency cut-off system and determining the maintenance cycle.

  9. Monte Carlo Analysis of Molecule Absorption Probabilities in Diffusion-Based Nanoscale Communication Systems with Multiple Receivers. (United States)

    Arifler, Dogu; Arifler, Dizem


    For biomedical applications of nanonetworks, employing molecular communication for information transport is advantageous over nano-electromagnetic communication: molecular communication is potentially biocompatible and inherently energy-efficient. Recently, several studies have modeled receivers in diffusion-based molecular communication systems as "perfectly monitoring" or "perfectly absorbing" spheres based on idealized descriptions of chemoreception. In this paper, we focus on perfectly absorbing receivers and present methods to improve the accuracy of simulation procedures that are used to analyze these receivers. We employ schemes available from the chemical physics and biophysics literature and outline a Monte Carlo simulation algorithm that accounts for the possibility of molecule absorption during discrete time steps, leading to a more accurate analysis of absorption probabilities. Unlike most existing studies that consider a single receiver, this paper analyzes absorption probabilities for multiple receivers deterministically or randomly deployed in a region. For random deployments, the ultimate absorption probabilities as a function of transmitter-receiver distance are shown to fit well to power laws; the exponents derived become more negative as the number of receivers increases up to a limit beyond which no additional receivers can be "packed" in the deployment region. This paper is expected to impact the design of molecular nanonetworks with multiple absorbing receivers.

  10. Reflux heat-pipe solar receiver for a Stirling dish-electric system

    Energy Technology Data Exchange (ETDEWEB)

    Ziph, B.; Godett, T.M.; Diver, R.B.


    The feasibility of competitive, modular bulk electric power from the sun is enhanced by the use of a reflux heat-pipe receiver to combine a Stirling engine with a paraboloidal dish concentrator. This combination represents a potential improvement over previous successful demonstrations of Stirling dish-electric technology in terms of enhanced performance, lower cost, and longer life. In the reflux (i.e. gravity assisted) heat-pipe receiver, concentrated solar radiation causes liquid sodium to evaporate, the vapor flows to the Stirling engine heaters where it condenses on the heater tubes. The condensate is returned to and distributed over the receiver by gravity (refluxing) and by capillary forces in a wick lining the receiver. It is essentially an adaptation of sodium heat pipe technology to the peculiar requirements of concentrated solar flux and provides many potential advantages over conventional tube receiver technology. This paper describes the preliminary design of a reflux heat-pipe solar receiver to match the STM4-120 variable swashplate Stirling engine to a Test Bed Concentrator at Sandia National Laboratories Distributed Receiver Test Facility. Performance analysis and other design considerations are presented and discussed.

  11. Performance Analysis of a Six-Port Receiver in a WCDMA Communication System including a Multipath Fading Channel

    Directory of Open Access Journals (Sweden)

    A. O. Olopade


    Full Text Available Third generation communication systems require receivers with wide bandwidth of operation to support high transmission rates and are also reconfigurable to support various communication standards with different frequency bands. An ideal software defined radio (SDR will be the absolute answer to this requirement but it is not achievable with the current level of technology. This paper proposes the use of a six-port receiver (SPR front-end (FE in a WCDMA communication system. A WCDMA end-to-end physical layer MATLAB demo which includes a multipath channel distortion block is used to determine the viability of the six-port based receiver. The WCDMA signal after passing through a multipath channel is received using a constructed SPR FE. The baseband signal is then calibrated and corrected in MATLAB. The six-port receiver performance is measured in terms of bit error rate (BER. The signal-to-noise ratio (SNR of the transmitted IQ data is varied and the BER profile of the communication system is plotted. The effect of the multipath fading on the receiver performance and the accuracy of the calibration algorithm are obtained by comparing two different measured BER curves for different calibration techniques to the simulated BER curve of an ideal receiver.

  12. To See the Unseen: A History of Planetary Radar Astronomy (United States)

    Butrica, Andrew J.


    This book relates the history of planetary radar astronomy from its origins in radar to the present day and secondarily to bring to light that history as a case of 'Big Equipment but not Big Science'. Chapter One sketches the emergence of radar astronomy as an ongoing scientific activity at Jodrell Bank, where radar research revealed that meteors were part of the solar system. The chief Big Science driving early radar astronomy experiments was ionospheric research. Chapter Two links the Cold War and the Space Race to the first radar experiments attempted on planetary targets, while recounting the initial achievements of planetary radar, namely, the refinement of the astronomical unit and the rotational rate and direction of Venus. Chapter Three discusses early attempts to organize radar astronomy and the efforts at MIT's Lincoln Laboratory, in conjunction with Harvard radio astronomers, to acquire antenna time unfettered by military priorities. Here, the chief Big Science influencing the development of planetary radar astronomy was radio astronomy. Chapter Four spotlights the evolution of planetary radar astronomy at the Jet Propulsion Laboratory, a NASA facility, at Cornell University's Arecibo Observatory, and at Jodrell Bank. A congeries of funding from the military, the National Science Foundation, and finally NASA marked that evolution, which culminated in planetary radar astronomy finding a single Big Science patron, NASA. Chapter Five analyzes planetary radar astronomy as a science using the theoretical framework provided by philosopher of science Thomas Kuhn. Chapter Six explores the shift in planetary radar astronomy beginning in the 1970s that resulted from its financial and institutional relationship with NASA Big Science. Chapter Seven addresses the Magellan mission and its relation to the evolution of planetary radar astronomy from a ground-based to a space-based activity. Chapters Eight and Nine discuss the research carried out at ground

  13. System-Level Design of an Integrated Receiver Front End for a Wireless Ultrasound Probe. (United States)

    Di Ianni, Tommaso; Hemmsen, Martin Christian; Llimos Muntal, Pere; Jorgensen, Ivan Harald Holger; Jensen, Jorgen Arendt


    In this paper, a system-level design is presented for an integrated receive circuit for a wireless ultrasound probe, which includes analog front ends and beamformation modules. This paper focuses on the investigation of the effects of architectural design choices on the image quality. The point spread function is simulated in Field II from 10 to 160 mm using a convex array transducer. A noise analysis is performed, and the minimum signal-to-noise ratio (SNR) requirements are derived for the low-noise amplifiers (LNAs) and A/D converters (ADCs) to fulfill the design specifications of a dynamic range of 60 dB and a penetration depth of 160 mm in the B-mode image. Six front-end implementations are compared using Nyquist-rate and Σ∆ modulator ADCs. The image quality is evaluated as a function of the depth in terms of lateral full-width at half-maximum (FWHM) and -12-dB cystic resolution (CR). The designs that minimally satisfy the specifications are based on an 8-b 30-MSPS Nyquist converter and a single-bit third-order 240-MSPS Σ∆ modulator, with an SNR for the LNA in both cases equal to 64 dB. The mean lateral FWHM and CR are 2.4% and 7.1% lower for the Σ∆ architecture compared with the Nyquist-rate one. However, the results generally show minimal differences between equivalent architectures. Advantages and drawbacks are finally discussed for the two families of converters.

  14. Multi-TID detection and characterization in a dense Global Navigation Satellite System receiver network (United States)

    Yang, Heng; Monte-Moreno, Enrique; Hernández-Pajares, Manuel


    The medium-scale traveling ionospheric disturbances (MSTIDs) constitute the most frequent ionospheric wave signatures. We propose a method for detecting the number of simultaneous MSTIDs from a time series of high-pass-filtered Vertical Total Electron Content (VTEC) maps and their parameters. The method is tested on the VTEC map corresponding to a simulated realistic scenario and on actual data from dual-frequency Global Positioning System (GPS) measurements gathered by +1200 GPS receivers of the GPS Earth Observation Network (GEONET) in Japan. The contribution consists of the detection of the number of independent MSTIDs from a nonuniform sampling of the ionospheric pierce points. The problem is set as a sparse decomposition on elements of a dictionary of atoms that span a linear space of possible MSTIDs. These atoms consist of plane waves characterized by a wavelength, direction, and phase on a surface defined, the part of the ionosphere sounded by the GEONET (i.e., 25°N to 50°N of latitude and 125°E to 155°E of longitude). The technique is related to the atomic decomposition and least absolute shrinkage and selection operator. The geophysical contribution of this paper is showing (a) the detection of several simultaneous MSTIDs of different characteristics, with a continuous change in the velocity; (b) detection of circular MSTID waves compatible by time and center with a specific earthquake; (c) simultaneous superposition of two distinct MSTIDs, with almost the same azimuth; and (d) the presence at nighttime of MSTIDs with velocities in the range 400-600 m/s.

  15. Industrial interference and radio astronomy (United States)

    Jessner, A.


    The interferer - victim scenario is described for the case of industrial interference affecting radio astronomical observatories. The sensitivity of radio astronomical receivers and their interference limits are outlined. EMC above 30 MHz is a serious problem for Radio Astronomy. Interferer (CISPR) and victim (ITU-R RA 769) standards are not harmonised. The emissions from the interferer and their spectral characteristics are not defined sufficiently well by CISPR standards. The required minimum coupling losses (MCL) between an industrial device and radio astronomical antenna depends on device properties but is shown to exceed 140 dB in most cases. Spatial separation of a few km is insufficient on its own, the terrain must shield > 30-40 dB, additional mitigations such as extra shielding or suppression of high frequency emissions may be necessary. A case by case compatibility analysis and tailored EMC measures are required for individual installations. Aggregation of many weak rfi emitters can become serious problem. If deployment densities are high enough, the emission constraints can even exceed those for a single interferer at a short distance from the radio observatory. Compatibility studies must account not only for the single interferer but also for many widely distributed interference sources.

  16. New Technology Lunar Astronomy Mission (United States)

    Chen, P. C.; Oliversen, R. J.; Barry, R. K.; Romeo, R.; Pitts, R.; Ma, K. B.


    A scientifically productive Moon-based observatory can be established in the near term (3-5 years) by robotic spacecraft. Such a project is affordable even taking into account NASA's currently very tight budget. In fact the estimated cost of a lunar telescope is sufficiently low that it can be financed by private industry, foundations, or wealthy individuals. The key factor is imaginative use of new technologies and new materials. Since the Apollo era, many new areas of space technology have been developed in the US by NASA, the military, academic and industry sectors, ESA, Japan, and others. These include ultralite optics, radiation tolerant detectors, precision telescope drives incorporating high temperature superconductors, smart materials, active optics, dust and thermal control structures, subminiature spectrometers, tiny radio transmitters and receivers, small rockets, innovative fuel saving trajectories, and small precision landers. The combination of these elements makes possible a lunar observatory capable of front line astrophysical research in UV-Vis-IR imaging, spectrometry, and optical interferometry, at a per unit cost comparable to that of Small Explorer (SMEX) class missions. We describe work in progress at NASA GSFC and elsewhere, applications to other space projects, and spinoff benefits to ground-based astronomy, industry, and education.

  17. Adaptive Jamming Suppression in Coherent FFH System Using Weighted Equal Gain Combining Receiver over Fading Channels with Imperfect CSI

    Directory of Open Access Journals (Sweden)

    Yishan He


    Full Text Available Fast frequency hopping (FFH is commonly used as an antijamming communication method. In this paper, we propose efficient adaptive jamming suppression schemes for binary phase shift keying (BPSK based coherent FFH system, namely, weighted equal gain combining (W-EGC with the optimum and suboptimum weighting coefficient. We analyze the bit error ratio (BER of EGC and W-EGC receivers with partial band noise jamming (PBNJ, frequency selective Rayleigh fading, and channel estimation errors. Particularly, closed-form BER expressions are presented with diversity order two. Our analysis is verified by simulations. It is shown that W-EGC receivers significantly outperform EGC. As compared to the maximum likelihood (ML receiver in conventional noncoherent frequency shift keying (FSK based FFH, coherent FFH/BPSK W-EGC receivers also show significant advantages in terms of BER. Moreover, W-EGC receivers greatly reduce the hostile jammers’ jamming efficiency.

  18. Should Astronomy Abolish Magnitudes? (United States)

    Brecher, K.


    Astronomy is riddled with a number of anachronistic and counterintuitive practices. Among these are: plotting increasing stellar temperature from right to left in the H-R diagram; giving the distances to remote astronomical objects in parsecs; and reporting the brightness of astronomical objects in magnitudes. Historical accident and observational technique, respectively, are the bases for the first two practices, and they will undoubtedly persist in the future. However, the use of magnitudes is especially egregious when essentially linear optical detectors like CCDs are used for measuring brightness, which are then reported in a logarithmic (base 2.512 deg!) scale. The use of magnitudes has its origin in three historical artifacts: Ptolemy's method of reporting the brightness of stars in the "Almagest"; the 19th century need for a photographic photometry scale; and the 19th century studies by psychophysicists E. H. Weber and G. T. Fechner on the response of the human eye to light. The latter work sought to uncover the relationship between the subjective response of the human eye and brain to the objective brightness of external optical stimuli. The resulting Fechner-Weber law states that this response is logarithmic: that is, that the eye essentially takes the logarithm of the incoming optical signal. However, after more than a century of perceptual studies, most intensively by S. S. Stevens, it is now well established that this relation is not logarithmic. For naked eye detection of stars from the first to sixth magnitudes, it can be reasonably well fit by a power law with index of about 0.3. Therefore, the modern experimental studies undermine the physiological basis for the use of magnitudes in astronomy. Should the historical origins of magnitudes alone be reason enough for their continued use? Probably not, since astronomical magnitudes are based on outdated studies of human perception; make little sense in an era of linear optical detection; and provide a

  19. Public Libraries as Partners in Astronomy Outreach (United States)

    Percy, J.


    Public libraries have proven to be effective partners in bringing astronomy to audiences across the large and diverse city of Toronto, Canada, and enabling astronomers - both young and old - to interact with members of our community. This article reflects on the author's experience working with public libraries, especially the Toronto Public Library (TPL), the busiest public library system in the world, to deliver over forty public presentations.

  20. SWUIS-A: A Versatile, Low-Cost UV/VIS/IR Imaging System for Airborne Astronomy and Aeronomy Research (United States)

    Durda, Daniel D.; Stern, S. Alan; Tomlinson, William; Slater, David C.; Vilas, Faith


    We have developed and successfully flight-tested on 14 different airborne missions the hardware and techniques for routinely conducting valuable astronomical and aeronomical observations from high-performance, two-seater military-type aircraft. The SWUIS-A (Southwest Universal Imaging System - Airborne) system consists of an image-intensified CCD camera with broad band response from the near-UV to the near IR, high-quality foreoptics, a miniaturized video recorder, an aircraft-to-camera power and telemetry interface with associated camera controls, and associated cables, filters, and other minor equipment. SWUIS-A's suite of high-quality foreoptics gives it selectable, variable focal length/variable field-of-view capabilities. The SWUIS-A camera frames at 60 Hz video rates, which is a key requirement for both jitter compensation and high time resolution (useful for occultation, lightning, and auroral studies). Broadband SWUIS-A image coadds can exceed a limiting magnitude of V = 10.5 in research done on each research mission. Key advantages of the small, high-performance aircraft on which we can fly SWUIS-A include significant cost savings over larger, more conventional airborne platforms, worldwide basing obviating the need for expensive, campaign-style movement of specialized large aircraft and their logistics support teams, and ultimately faster reaction times to transient events. Compared to ground-based instruments, airborne research platforms offer superior atmospheric transmission, the mobility to reach remote and often-times otherwise unreachable locations over the Earth, and virtually-guaranteed good weather for observing the sky. Compared to space-based instruments, airborne platforms typically offer substantial cost advantages and the freedom to fly along nearly any groundtrack route for transient event tracking such as occultations and eclipses.

  1. Use of hydrofluoroalkane propellant delivery system for inhaled albuterol in patients receiving asthma medications. (United States)

    Boccuzzi, S J; Wogen, J; Roehm, J B


    This study was undertaken to assess drug-use patterns associated with albuterol delivery via a new propellant device compared with conventional chlorofluorocarbon (CFC) metered-dose inhalers (MDIs) in patients taking asthma medications in a population with pharmacy benefits. In addition to their ozone-depleting properties, conventional CFC inhalers often deliver inconsistent doses because of loss of prime and temperature instability. A new propellant, hydrofluoroalkane (HFA), incorporates a re-engineered delivery system associated with dosing reproducibility throughout the life of the canister. Drug markers associated with management of asthma were used to identify a study cohort of new users of inhaled albuterol from a geographically diverse pharmacyclaims database from July 1, 1997, through December 31, 1997. A population of 282,879 members was identified over the 20-month follow-up period. In addition, a subset of chronic albuterol inhaler users (> or = 12 months; n = 96,879) was also identified to support a longitudinal analysis. Disease severity was controlled for by use of inhaled corticosteroids (ICS). To control for canisters received via physician office samples, HFA patient use was corrected by a physician-based canister adjustment based on HFA sample data. A total of 53.1% of participants were women and 46.1% were men; most of the population (72.5%) was therapy and physician samples associated with product launch were controlled for, similar differences were consistently observed. CFC patients used, on average, 1.3 more canisters per year than did HFA patients (P < 0.001), averaging 10.7 canisters (95% CI, 10.6 to 10.7), compared with 9.4 canisters used by HFA patients (95% CI, 8.9 to 9.9). Further analyses indicated that this finding was consistent when ICS use was controlled for (CFC plus ICS mean, 11.9 canisters vs HFA plus ICS mean, 10.4 canisters; P < 0.001). This study provides useful information about the effect of use of a new albuterol delivery

  2. Spreading Astronomy Education Through Africa (United States)

    Baki, P.


    Although Astronomy has been an important vehicle for effectively passing a wide range of scientific knowledge, teaching the basic skills of scientific reasoning, and for communicating the excitement of science to the public, its inclusion in the teaching curricula of most institutions of higher learning in Africa is rare. This is partly due to the fact that astronomy appears to be only good at fascinating people but not providing paid jobs. It is also due to the lack of trained instructors, teaching materials, and a clear vision of the role of astronomy and basic space science within the broader context of education in the physical and applied sciences. In this paper we survey some of the problems bedeviling the spread of astronomy in Africa and discuss some interdisciplinary traditional weather indicators. These indicators have been used over the years to monitor the appearance of constellations. For example, orions are closely intertwined with cultures of some ethnic African societies and could be incorporated in the standard astronomy curriculum as away of making the subject more `home grown' and to be able to reach out to the wider populace in popularizing astronomy and basic sciences. We also discuss some of the other measures that ought to be taken to effectively create an enabling environment for sustainable teaching and spread of astronomy through Africa.

  3. Social Representations of the Integrated High School Students about Astronomy (United States)

    Barbosa, Jose Isnaldo de Lima; Voelzke, Marcos Rincon


    Astronomy issues are not always adequately handled in the formal education system, as well as, their dissemination in the media is often loaded with sensationalism. However, in this context the students are forming their explanations about it. Therefore, this work has the objective of identifying the possible social representations of students from the Integrated High School on the inductor term Astronomy. It is basically a descriptive research, therefore, a quali-qualitative approach was adopted. The procedures for obtaining the data occurred in the form of a survey, and they involved 653 subjects students from the Integrated High School. The results indicate that the surveyed students have social representations of the object Astronomy, which are based on elements from the formal education space, and also disclosed in the media. In addition, they demonstrate that the students have information about Astronomy, and a value judgment in relation to this science.

  4. Astronomy Enrollments and Degrees: Results from the 2012 Survey of Astronomy Enrollments and Degrees. Focus On (United States)

    Mulvey, Patrick; Nicholson, Starr


    Interest in astronomy degrees in the U.S. remains strong, with astronomy enrollments at or near all-time highs for the 2012-13 academic year. The total number of students taking an introductory astronomy course at a degree-granting physics or astronomy department is approaching 200,000. Enrollments in introductory astronomy courses have been…

  5. Terahertz heterodyne technology for astronomy and planetary science

    NARCIS (Netherlands)

    Wild, Wolfgang


    Heterodyne detection techniques play an important role in high-resolution spectroscopy in astronomy and planetary science. In particular, heterodyne technology in the Terahertz range has rapidly evolved in recent years. Cryogenically cooled receivers approaching quantum-limited sensitivity have been

  6. Charge and Discharge Analyses of a PCM Storage System Integrated in a High-Temperature Solar Receiver

    Directory of Open Access Journals (Sweden)

    Ambra Giovannelli


    Full Text Available Solar Dish Micro Gas Turbine (MGT systems have the potential to become interesting small-scale power plants in off-grid or mini-grid contexts for electricity or poly-generation production. The main challenging component of such systems is the solar receiver which should operate at high temperatures with concentrated solar radiations, which strongly vary with time. This paper deals with the design and the analysis of a novel solar receiver integrated with a short-term storage system based on Phase Change Materials to prevent sudden variations in the maximum temperature of the MGT working fluid. Particularly, the charge and discharge behavior of the storage system was analyzed by means of Computational Fluid Dynamic methods to evaluate the potentiality of the concept and the component capabilities. Achieved results were highly satisfactory: the novel solar receiver has a good thermal inertia and can prevent relevant fluctuations in the working fluid temperature for 20–30 min.

  7. Astronomy and political theory (United States)

    Campion, Nicholas


    This paper will argue that astronomical models have long been applied to political theory, from the use of the Sun as a symbol of the emperor in Rome to the application of Copernican theory to the needs of absolute monarchy. We will begin with consideration of astral divination (the use of astronomy to ascertain divine intentions) in the ancient Near East. Particular attention will be paid to the use of Newton's discovery that the universe operates according to a single set of laws in order to support concepts of political quality and eighteenth century Natural Rights theory. We will conclude with consideration of arguments that the discovery of the expanding, multi-galaxy universe, stimulated political uncertainty in the 1930s, and that photographs of the Earth from Apollo spacecraft encouraged concepts of the `global village'.

  8. Superconducting detectors in astronomy (United States)

    Rahman, F.


    Radiation detectors based on superconducting phenomena are becoming increasingly important for observational astronomy. Recent developments in this important field, together with relevant background, are described here. After a general introduction to superconductivity and the field of superconductor-based radiation sensors, the main detector types are examined with regard to their physical form, operating principles and principal advantages. All major forms of superconducting detectors used in contemporary research such as tunnelling detectors, mixers, hot-electron bolometers and transition edge sensitive devices are discussed with an emphasis on how more recent developments are overcoming the shortcomings of the previous device generations. Also, discussed are new ideas in superconducting detector technology that may find applications in the coming years.

  9. The Interactive Astronomy Textbook (United States)

    Fluke, Christopher J.; Barnes, David G.

    We introduce the use of in situ interactive three-dimensional (3-d) figures in digital astronomy textbooks as a means of enhancing student learning. The recent 3-d extensions to the Adobe Portable Document Format (PDF), combined with simple JavaScript, provide new ways to present intrinsically 3-d models, data sets, and instructional diagrams in digital publications. This is an enhancement to the usual method of presenting static, two-dimensional views, or "comic strip" sequences, to indicate changes in viewpoint. Interactive figures provide opportunities for students to undertake active learning while reading a textbook: they are able to explore and uncover the connections between viewpoint, orientation, and the 3-d nature of models and data sets for themselves.

  10. Gravitational wave astronomy

    CERN Multimedia

    CERN. Geneva


    In the past year, the LIGO-Virgo Collaboration announced the first secure detection of gravitational waves. This discovery heralds the beginning of gravitational wave astronomy: the use of gravitational waves as a tool for studying the dense and dynamical universe. In this talk, I will describe the full spectrum of gravitational waves, from Hubble-scale modes, through waves with periods of years, hours and milliseconds. I will describe the different techniques one uses to measure the waves in these bands, current and planned facilities for implementing these techniques, and the broad range of sources which produce the radiation. I will discuss what we might expect to learn as more events and sources are measured, and as this field matures into a standard part of the astronomical milieu.

  11. Astronomy a visual guide

    CERN Document Server

    Garlick, Mark A


    Space has fascinated man and challenged scientists for centuries and astronomy is the oldest and one of the most dynamic of the sciences. Here is a book that will stimulate your curiosity and feed your imagination. Detailed and fascinating text is clearly and richly illustrated with fabulous, vibrant photographs and diagrams. This is a comprehensive guide to understanding and observing the night sky, from distant stars and galaxies to our neighbouring planets; from comets to shooting stars; from eclipses to black holes. With details of the latest space probes, a series of monthly sky maps to provide guidance for the amateur observer and the latest photos from space, this book brings the beauty and wonder of our universe into your living room and will have you reaching for the telescope!

  12. The Development of the Astronomy Digital Library (United States)

    Eichhorn, G.; Accomazzi, A.; Grant, C. S.; Kurtz, M. J.; Murray, S. S.


    The Astronomy Digital Library provides access to astronomical literature and to on-line data. The Astrophysics Data System (ADS) is the literature search system and archive in this library. It is a NASAfunded project and access to all the ADS services is free to everybody world-wide. The ADS Abstract Service allows the searching of four databases with abstracts in Astronomy, Instrumentation, Physics/Geophysics, and the ArXiv Preprints with a total of over 2.9 million references. The system also provides access to reference and citation information, links to on-line data, electronic journal articles, and other on-line information. The ADS Article Service contains the full articles for most of the astronomical literature back to Volume 1. It contains the scanned pages of all the major journals (Astrophysical Journal, Astronomical Journal, Astronomy & Astrophysics, Monthly Notices of the Royal Astronomical Society, and Solar Physics), as well as most smaller journals back to Volume 1. There are now 10 mirror sites of the ADS available in different parts of the world to improve connectivity. The ADS can be accessed through any web browser without signup or login at:

  13. Astronomy in laboratory (United States)

    Suzuki, B.


    It is not easy to practice astronomical observation in a high school. It is difficult to teach authentic astronomy because real-world conditions cannot be reproduced in the classroom. However, the following ideas produce some interesting experiments. 1. The reappearance experiment of the meteor spectrum. We produced emission spectra by using a gas burner and welding. It can be understood that the luminosity of emission lines varies according to temperature. Furthermore, we mixed in liquid chlorides of Na, Ca, Fe, Sg, Si, etc., in different proportions tomimic different meteor spectra. We then observed the time changes of the luminosity using a video camcorder that we attached to a spectroscope. The spectrum in the experiment closely resembled that of a meteor. 2. The verification of the black-drop phenomenon.Long ago, the black-drop phenomenon became important in the case of Venus's passage between the Earth and the Sun, a transit of Venus. We tried to reproduce this phenomenon by using a small ball painted black, solar light, and an artificial illuminant. The profile of the reproduced image was then checked in detail. We found that this phenomenon depended on the influence of the limb darkening of the Sun, the scintillation of the Earth's atmosphere, and the optical performance of the telescope. Furthermore, we imitated Venus's atmosphere as an additional experiment by applying oil on the surface of the small ball. It resulted in an interesting profile but was not a sufficient experiment. Of course, these experiments are in conditions that are very different from the actual physical conditions. However, we think that they provide a very effective method for enhancing students' interest in astronomy. We are planning other experiments with similar themes.

  14. Applied Historical Astronomy (United States)

    Stephenson, F. Richard


    F. Richard Stephenson has spent most of his research career -- spanning more than 45 years -- studying various aspects of Applied Historical Astronomy. The aim of this interdisciplinary subject is the application of historical astronomical records to the investigation of problems in modern astronomy and geophysics. Stephenson has almost exclusively concentrated on pre-telescopic records, especially those preserved from ancient and medieval times -- the earliest reliable observations dating from around 700 BC. The records which have mainly interested him are of eclipses (both solar and lunar), supernovae, sunspots and aurorae, and Halley's Comet. The main sources of early astronomical data are fourfold: records from ancient and medieval East Asia (China, together with Korea and Japan); ancient Babylon; ancient and medieval Europe; and the medieval Arab world. A feature of Stephenson's research is the direct consultation of early astronomical texts in their original language -- either working unaided or with the help of colleagues. He has also developed a variety of techniques to help interpret the various observations. Most pre-telescopic observations are very crude by present-day standards. In addition, early motives for skywatching were more often astrological rather than scientific. Despite these drawbacks, ancient and medieval astronomical records have two remarkable advantages over modern data. Firstly, they can enable the investigation of long-term trends (e.g. in the terrestrial rate of rotation), which in the relatively short period covered by telescopic observations are obscured by short-term fluctuations. Secondly, over the lengthy time-scale which they cover, significant numbers of very rare events (such as Galactic supernovae) were reported, which have few -- if any-- counterparts in the telescopic record. In his various researches, Stephenson has mainly focused his attention on two specific topics. These are: (i) long-term changes in the Earth's rate of

  15. Astronomy Popularization via Sci-fi Movies (United States)

    Li, Qingkang


    It is astronomers’ duty to let more and more young people know a bit astronomy and be interested in astronomy and appreciate the beauty and great achievements in astronomy. One of the most effective methods to popularize astronomy to young people nowadays might be via enjoying some brilliant sci-fi movies related to astronomy with some guidance from astronomers. Firstly, we will introduce the basic information of our selective course “Appreciation of Sci-fi Movies in Astronomy” for the non-major astronomy students in our University, which is surely unique in China, then we will show its effect on astronomy popularization based on several rounds of teaching.

  16. The Profile of Astronomy Amateurs (United States)

    Czart, K.

    Presentation of questionnaires carried out on Polish Astronomy Portal websites. There was over 80 questionnaires during 2 years period. As most part of users visiting this website are astronomy amateurs, we can assume questionnaires give a picture of astronomy amateurs community. Questionnaires can be divided into four main thematical groups: profile of users (age, sex, activities), what do they think about controversial astronomical problems (is Pluto a planet?), what are their likings (favorit star, most beatiful planet) and “business” questions (how did they find our website?, how many astronomical services do they visit regularly?).

  17. Astronomy at the frontiers of science

    CERN Document Server


    Astronomy is by nature an interdisciplinary activity: it involves mathematics, physics, chemistry and biology. Astronomers use (and often develop) the latest technology, the fastest computers and the most refined software.  In this book twenty-two leading scientists from nine countries talk about how astronomy interacts with these other sciences. They describe modern instruments used in astronomy and the relations between astronomy and technology, industry, politics and philosophy. They also discuss what it means to be an astronomer, the history of astronomy, and the place of astronomy in society today.   The book contains twenty chapters grouped in four parts: ASTRONOMY AND PHYSICS discusses the place of astronomy among various branches of (mostly high-energy) physics. ASTRONOMY IN SOCIETY describes not only the historical context of astronomy, but issues facing astronomers today, including funding, planning, worldwide collaboration and links with industry. THE TOOLS OF OBSERVATION AND THE PROFESSION OF AS...

  18. Introducing Astronomy Related Research into Non-Astronomy Courses (United States)

    Walker, Douglas

    The concern over the insufficient number of students choosing to enter the science and engineering fields has been discussed and documented for years. While historically addressed at the national level, many states are now recognizing that the lack of a highly-skilled technical workforce within their states' borders has a significant effect on their economic health. Astronomy, as a science field, is no exception. Articles appear periodically in the most popular astronomy magazines asking the question, "Where are the young astronomers?" Astronomy courses at the community college level are normally restricted to introductory astronomy I and II level classes that introduce the student to the basics of the night sky and astronomy. The vast majority of these courses is geared toward the non-science major and is considered by many students to be easy and watered down courses in comparison to typical physics and related science courses. A majority of students who enroll in these classes are not considering majors in science or astronomy since they believe that science is "boring and won't produce any type of career for them." Is there any way to attract students? This paper discusses an approach being undertaken at the Estrella Mountain Community College to introduce students in selected mathematics courses to aspects of astronomy related research to demonstrate that science is anything but boring. Basic statistical techniques and understanding of geometry are applied to a large virgin data set containing the magnitudes and phase characteristics of sets of variable stars. The students' work consisted of developing and presenting a project that explored analyzing selected aspects of the variable star data set. The description of the data set, the approach the students took for research projects, and results from a survey conducted at semester's end to determine if student's interest and appreciation of astronomy was affected are presented. Using the data set provided, the

  19. Preservice elementary teachers learning of astronomy (United States)

    Fidler, Chuck Gary

    The dissertation presents a new approach for the study of preservice elementary teacher astronomy education. The approach suggests that learning astronomical concepts are facilitated by greater sophistication in scale perception and spatial-aptitude. This dissertation is underscored by the national call for elementary science education reform efforts and suggests certain strategies shown more effective for the development of accurate astronomical comprehension. The present research study describes how preservice elementary teachers conceptualize and communicate ideas about Space. Instead of assuming a universal mental conception of cosmic orientations and relationships, the dissertation claims that the perception of Space related dimensions vary among preservice elementary teachers. Furthermore, the dissertation suggests individual perceptions of the scale sizes and orientations of celestial systems have direct influences on mental models used to organize and communicate astronomical information. The development of inaccurate mental models of the scaled dimensions of Space may perpetuate the teacher-student cycle of misconception and naive-theory generation among children in elementary education settings. The ability to conceptualize the vast cosmos is facilitated by the minds ability to think about vast scales and orientations of celestial objects. The Earth-based perspective of astronomy education compels the learner to think about astronomical principles within imaginary frames of reference and across unfamiliar scaled dimensions. Therefore, mental astronomical model building is underscored by the perception of scale and cosmic spatiality. This study suggests these cognitive skill sets are interconnected and facilitate the learning of accurate astronomy principles; as well as play an important role when designing an astronomy education program for preservice elementary teachers. This research study is comprised of three separate standalone articles designed and

  20. Preliminary design of a solar heat receiver for a Brayton cycle space power system (United States)

    Cameron, H. M.; Mueller, L. A.; Namkoong, D.


    The preliminary design of a solar heat receiver for use as a heat source for an earth-orbiting 11-kWe Brayton-cycle engine is described. The result was a cavity heat receiver having the shape of a frustum of a cone. The wall of the cone is formed by 48 heat-transfer tubes, each tube containing pockets of lithium fluoride for storing heat for as much as 38 minutes of fullpower operation in the shade. Doors are provided in order to dump excess heat especially during operation in orbits with full sun exposure. The receiver material is predominantly columbium - 1-percent-zironium (Cb-1Zr) alloy. Full-scale testing of three heat-transfer tubes for more than 2000 hours and 1250 sun-shade cycles verified the design concept.

  1. Advanced topographic laser altimeter system (ATLAS) receiver telescope assembly (RTA) and transmitter alignment and test (United States)

    Hagopian, John; Bolcar, Matthew; Chambers, John; Crane, Allen; Eegholm, Bente; Evans, Tyler; Hetherington, Samuel; Mentzell, Eric; Thompson, Patrick L.; Ramos-Izquierdo, Luis; Vaughnn, David


    The sole instrument on NASA's ICESat-2 spacecraft shown in Figure 1 will be the Advanced Topographic Laser Altimeter System (ATLAS)1. The ATLAS is a Light Detection and Ranging (LIDAR) instrument; it measures the time of flight of the six transmitted laser beams to the Earth and back to determine altitude for geospatial mapping of global ice. The ATLAS laser beam is split into 6 main beams by a Diffractive Optical Element (DOE) that are reflected off of the earth and imaged by an 800 mm diameter Receiver Telescope Assembly (RTA). The RTA is composed of a 2-mirror telescope and Aft Optics Assembly (AOA) that collects and focuses the light from the 6 probe beams into 6 science fibers. Each fiber optic has a field of view on the earth that subtends 83 micro Radians. The light collected by each fiber is detected by a photomultiplier and timing related to a master clock to determine time of flight and therefore distance. The collection of the light from the 6 laser spots projected to the ground allows for dense cross track sampling to provide for slope measurements of ice fields. NASA LIDAR instruments typically utilize telescopes that are not diffraction limited since they function as a light collector rather than imaging function. The more challenging requirements of the ATLAS instrument require better performance of the telescope at the ¼ wave level to provide for improved sampling and signal to noise. NASA Goddard Space Flight Center (GSFC) contracted the build of the telescope to General Dynamics (GD). GD fabricated and tested the flight and flight spare telescope and then integrated the government supplied AOA for testing of the RTA before and after vibration qualification. The RTA was then delivered to GSFC for independent verification and testing over expected thermal vacuum conditions. The testing at GSFC included a measurement of the RTA wavefront error and encircled energy in several orientations to determine the expected zero gravity figure, encircled

  2. Central Receiver Solar Thermal Power System, Phase 1. CDRL Item 10. First quarterly technical progress report

    Energy Technology Data Exchange (ETDEWEB)

    Hallet, Jr., R. W.; Gervais, R. L.


    The current definition of a 10-MWe pilot plant preliminary design base line is presented, as well as a summary of a 100-MWe commercial plant base line. The subsystems described for the plants include the collector, receiver, thermal storage, and electrical power generation. A master control concept employing a centralized computer is also described. The subsystem research experiment activities for the collector, receiver, and thermal storage subsystems are presented, including a summary of SRE test requirements, overall test scheduling, and status through the conceptual design review phase of the SRE effort.

  3. Electronic Imaging in Astronomy Detectors and Instrumentation

    CERN Document Server

    McLean, Ian


    The second edition of Electronic Imaging in Astronomy: Detectors and Instrumentation describes the remarkable developments that have taken place in astronomical detectors and instrumentation in recent years – from the invention of the charge-coupled device (CCD) in 1970 to the current era of very large telescopes, such as the Keck 10-meter telescopes in Hawaii with their laser guide-star adaptive optics which rival the image quality of the Hubble Space Telescope. Authored by one of the world’s foremost experts on the design and development of electronic imaging systems for astronomy, this book has been written on several levels to appeal to a broad readership. Mathematical expositions are designed to encourage a wider audience, especially among the growing community of amateur astronomers with small telescopes with CCD cameras. The book can be used at the college level for an introductory course on modern astronomical detectors and instruments, and as a supplement for a practical or laboratory class.

  4. Solar central receiver hybrid power system. Monthly technical progress report for the month of December 1978

    Energy Technology Data Exchange (ETDEWEB)



    Levelized busbar energy costs for the sodium-cooled hybrid central receiver concept using both oil and coal as a fuel were developed as a function of the plant capacity factor and as a function of the solar multiple. The fuel escalation question was reviewed in detail on the basis of past historical data, and it was concluded that the lower escalation numbers that are provided in the requirements definition document appear to be more likely to represent the real situation. Subsystem-level trade studies were continued during this reporting period. A detailed investigation of the series/parallel arrangement of the sodium heater and solar receiver was conducted. The various performance, lifetime, and cost factors were determined for each arrangement for the receiver and nonsolar subsystems, respectively. Collector subsystem studies were continued. Revised cost algorithms that include levelized O and M costs for the heliostats were generated in order that they can be used in the field optimization. On the basis of the subsystem studies and the economic assessment work, a reference configuration was tentatively derived. This configuration does not require storage and uses a parallel arrangement of the receiver and the heater. At this time, a coal-fired heater seems to have a potential economic advantage under realistic assumptions for the escalation of coal relative to oil over the next decade or so.

  5. Developing a magnetic sign system to ensure patients receive appropriate nutritional care. (United States)

    Tabiner, Ann; Lewis, Lianne

    The Department of Health has acknowledged that at times patients are not receiving the correct nutritional care to support them to eat and drink. Nutritional link nurses at Milton Keynes Hospital Foundation Trust developed a tool to ensure that all staff, patients and relatives were aware opatients' current andcorrect nutritional status.

  6. An Efficient Rank Adaptation Algorithm for Cellular MIMO Systems with IRC Receivers

    DEFF Research Database (Denmark)

    Mahmood, Nurul Huda; Berardinelli, Gilberto; Tavares, Fernando Menezes Leitão


    of linear interference rejection combining (IRC) receivers. Typically, rank adaptation algorithms are aimed at balancing the trade-off between increasing the spatial gain, and improving the interference resilience property. In this paper, we propose an efficient and computationally effective rank adaptation...

  7. Essays on medieval computational astronomy

    CERN Document Server

    Bergón, José Chabás


    In Essays on Medieval Computational Astronomy the authors provide examples of original and intelligent approaches and solutions given by medieval astronomers to the problems of their discipline, mostly presented in the form of astronomical tables.

  8. From astronomy to data science (United States)

    Rodriguez Zaurín, Javier


    After almost ten years in academia I took one of the best decisions of my life: to leave it. This is my experience transitioning from astronomy to data science in search of a more open, fast-paced working environment.

  9. Critical Issues in the Philosophy of Astronomy and Cosmology (United States)

    Dick, Steven J.


    Although the philosophy of science and of specific sciences such as physics, chemistry, and biology are well-developed fields with their own books and journals, the philosophy of astronomy and cosmology have received little systematic attention. At least six categories of problems may be identified in the astronomical context: 1) the nature of reasoning, including the roles of observation, theory, simulation, and analogy, as well as the limits of reasoning, starkly evident in the anthropic principle, fine-tuning, and multiverse controversies; 2) the often problematic nature of evidence and inference, especially since the objects of astronomical interest are for the most part beyond experiment and experience;3) the influence of metaphysical preconceptions and non-scientific worldviews on astronomy, evidenced, for example in the work of Arthur S. Eddington and many other astronomers; 4) the epistemological status of astronomy and its central concepts, including the process of discovery, the problems of classification, and the pitfalls of definition (as in planets); 5) the role of technology in shaping the discipline of astronomy and our view of the universe; and 6) the mutual interactions of astronomy and cosmology with society over time. Discussion of these issues should draw heavily on the history of astronomy as well as current research, and may reveal an evolution in approaches, techniques, and goals, perhaps with policy relevance. This endeavor should also utilize and synergize approaches and results from philosophy of science and of related sciences such as physics (e.g. discussions on the nature of space and time). Philosophers, historians and scientists should join this new endeavor. A Journal of the Philosophy of Astronomy and Cosmology (JPAC) could help focus attention on their studies.

  10. Music and Astronomy Under the Stars - 2009 Update (United States)

    Lubowich, Donald A.


    Bring telescope to where the people are! Music and Astronomy Under the Stars is a three-year NASA-funded outreach program at parks during and after concerts and family events - a Halloween Spooky Garden Walk. While there have been many outreach activities and telescope observations at city sidewalks and parks, this program targets a completely different audience - music lovers who attend summer concerts held in community parks. These music lovers who may never have visited a science museum, planetarium, or star party are exposed to telescope observations and astronomy information with no additional travel costs. Music and Astronomy Under the Stars increased awareness, engagement, and interest in astronomy at classical, pop, rock, and ethnic music concerts. This program includes solar observing before the concerts, telescope observations including a live image projection system, an astronomical video presentation, and astronomy banners/posters. Approximately 500 - 16,000 people attended each event and 25% to 50% of the people at each event participated in the astronomy program. This program also reached underrepresented and underserved groups (women, minorities, older adults). The target audience is 2,900,000 people, which is larger than combined population of Atlanta, Boston, Denver, Minneapolis, and San Francisco. Although eleven events were planned in 2009, two were canceled due to rain and our largest event, the NY Philharmonic in the Park (attended by 67,000 people in 2008), was cancelled for financial reasons. Our largest event in 2009 was the Tanglewood Music Festival, Lenox MA, attended by 16,000 people where 5000 people participated in astronomy activities. The Amateur Observers' Society of NY assisted with the NY concerts and the Springfield STARS club assisted at Tanglewood. 1500 people looked through telescopes at the Halloween program (6000 saw the posters). In 2009 over 15,000 people participated in these astronomy activities which were attended by

  11. Pondering astronomy's perplexingly preposterous propositions (United States)

    Slater, Tim


    Astronomy is one of those ideas that naturally makes one wonder. Questions of how big? how far? how many? and how long? are just a few ideas that naturally present themselves when one contemplates the night sky and the universe. Despite astronomy's inherent ability to captivate students' interest, even master teachers need an evolving toolkit of innovative strategies to intellectually engage students, particularly in the domain of critical thinking.

  12. Bibliometric Evaluation of Finnish Astronomy (United States)

    Isaksson, E.


    Finnish astronomy publishing provides us with an interesting data sample. It is small but not too small: approximately one thousand articles have been published in a decade. There are only four astronomy institutes to be compared. An interesting paradox also emerges in the field: while Finnish science assessments usually value highly the impact of scientific publishing, no serious evaluations using real bibliometric data have been made. To remedy this, a comprehensive ten-year database of refereed papers was collected and analyzed.

  13. Three-dimensional indoor visible light positioning system with a single transmitter and a single tilted receiver (United States)

    Li, Qing-Lin; Wang, Jin-Yuan; Huang, Ting; Wang, Yongjin


    Recently, visible light positioning has gradually become a research hotspot in indoor environments. Based on a single transmitter and a single tilted optical receiver, a three-dimensional (3-D) indoor visible light positioning system is proposed. The tilted optical receiver is installed on a rotatable and retractable platform. The 3-D space is divided many two-dimensional (2-D) planes by lifting the platform of the optical receiver. In each 2-D plane, various azimuth angles can be obtained by rotating the receiver platform, which offers a feasible way to perform multiple measurements with different azimuth angles to achieve the angle gain. According to the difference of the angle gain, a 3-D positioning algorithm is proposed. Experimental results show that the proposed positioning algorithm can provide good positioning accuracy.

  14. Astronomy in Primary and Secondary Education in Slovenia (United States)

    Gomboc, Andreja


    I will present the status of astronomy in educational system in Slovenia. In primary schools astronomy is offered as an optional course in the last 3 grades (12-15 yrs old), while in secondary schools a few astronomical topics are present only as part of other subjects (e.g. physics, geography). I will describe a pilot project of an astronomy course in secondary schools, which was carried out in the school year 2013/14. The main focus of my presentation will be the experience gained with organisation of the Slovenian National Astronomy Competition. It is organised by the Slovenian Society of Mathematicians, Physicists and Astronomers since 2009, building on an extensive network of over 200 primary and secondary school teachers who participated in IYA2009 activities, and who now represent majority of mentors for the competition. In 2013, only 5 years after the start of competition, our pupils attended the International Olympiad on Astronomy and Astrophysics for the first time and with great success. Supporting activities include the Slovenian version of the Portal to the Universe ( and translation of Space Scoop astronomy news for children.

  15. Astronomy at the Market (United States)

    Roten, Robert; Constantin, A.; Christensen, E.; Dick, E.; Lapolla, J.; Nutter, A.; Corcoran, J.; DiDomenico, N.; Eskridge, B.; Saikin, A.


    We present here an energetic grass-roots outreach program run entirely by undergraduate physics and astronomy majors at James Madison University. Our "Team Awestronomy" takes Astronomy out to the Market, literally. Once a month, for eight months during the academic year, the group sets up a “scientific corner” at the Harrisonburg Farmers Market, offering people the chance to meet with astrophysicists (in the making) and discuss science. Our group members wear t-shirts with simple messages like “Ask me about the Sun,” “...about Black Holes and Mega-Masers” or “...about Big Bang” that initiate the dialog. We help our audience with observations of solar activity through our department’s Coronado telescope equipped with a safe H-alpha filter, sunspotters, and the incredibly simple yet durable and accurate handheld (Project Star) spectrometers, and invite them to the free Saturday Planetarium shows and the star parties hosted by our department on the JMU campus. The team is also prepared with a suite of fun activities aimed particularly at K-5 kids, e.g., building (and eating, after investigating out-gassing properties of) ”dirty comets,” making craters (in pans with flour or sand) and testing how different types of impactors (pebbles, ping-pong balls or even crumpled aluminum foil) affect crater formation, and demonstrations of shock wave created in supernova explosions. The main goals of this outreach program are: 1) to illustrate to people of all ages that science is a fun, creative, and exciting process; 2) to empower people to be curious and to ask questions; 3) to demonstrate that science is a viable career path chosen by many diverse individuals; and 4) to nurture a sense of wonder and awe for the Universe. While this outreach program is aimed at a very general audience, of an extremely wide range, we expect to produce a significant impact on K-12 students in general and in particular on the home-schooled kids. There is a relatively high

  16. Results from the Longitudinal Study of Astronomy Graduate Students (United States)

    Ivie, Rachel


    The Longitudinal Study of Astronomy Graduate Students (LSAGS), an ongoing, joint project of the American Astronomical Society (AAS) and the American Institute of Physics (AIP), first collected survey data from astronomy and astrophysics graduate students in 2007-08. The LSAGS follows the same people, all of whom were in graduate school in 2006-07, over time as they start their careers. Most of the respondents are currently working as postdocs. There have been two rounds of the survey so far, and we have recently received funding for a third round from the National Science Foundation (AST-1347723). Results from the first round showed the importance of mentoring for graduate students. Data collection for the second round has been completed, and AIP has just begun analysis of these data. At this talk, I will present the results of the second survey. Ultimately, the LSAGS will *provide detailed data on trends in employment over 10+ years for a single cohort, *collect data on people who leave the field of astronomy during or after graduate school, *determine whether there are sex differences in attrition from astronomy and reasons for this, and *examine factors that precede decisions to persist in, or leave, the field of astronomy.

  17. Intelligent Cognitive Radio Models for Enhancing Future Radio Astronomy Observations

    Directory of Open Access Journals (Sweden)

    Ayodele Abiola Periola


    Full Text Available Radio astronomy organisations desire to optimise the terrestrial radio astronomy observations by mitigating against interference and enhancing angular resolution. Ground telescopes (GTs experience interference from intersatellite links (ISLs. Astronomy source radio signals received by GTs are analysed at the high performance computing (HPC infrastructure. Furthermore, observation limitation conditions prevent GTs from conducting radio astronomy observations all the time, thereby causing low HPC utilisation. This paper proposes mechanisms that protect GTs from ISL interference without permanent prevention of ISL data transmission and enhance angular resolution. The ISL transmits data by taking advantage of similarities in the sequence of observed astronomy sources to increase ISL connection duration. In addition, the paper proposes a mechanism that enhances angular resolution by using reconfigurable earth stations. Furthermore, the paper presents the opportunistic computing scheme (OCS to enhance HPC utilisation. OCS enables the underutilised HPC to be used to train learning algorithms of a cognitive base station. The performances of the three mechanisms are evaluated. Simulations show that the proposed mechanisms protect GTs from ISL interference, enhance angular resolution, and improve HPC utilisation.

  18. Astronomy in India a historical perspective

    CERN Document Server


    India has a strong and ancient tradition of astronomy, which seamlessly merges with the current activities in Astronomy and Astrophysics in the country. While the younger generation of astronomers and students are reasonably familiar with the current facilities and the astronomical research, they might not have an equally good knowledge of the rich history of Indian astronomy. This particular volume, brought out as a part of the Platinum Jubilee Celebrations of Indian National Science Academy, concentrates on selected aspects of historical development of Indian astronomy in the form of six invited chapters. Two of the chapters – by Balachandra Rao and M.S. Sriram – cover ancient astronomy and the development of calculus in the ancient Kerela text Yuktibhasa. The other four chapters by B.V. Sreekantan, Siraj Hasan, Govind Swarup and Jayant Narlikar deal with the contemporary history of Indian astronomy covering space astronomy, optical astronomy, radio astronomy and developments in relativistic astrophysic...

  19. Astronomy and Atmospheric Optics (United States)

    Cowley, Les; Gaina, Alex


    The authors discusse the insuccess of the observation of the Total Eclipse of the Moon from 10 december 2011 in Romania and relate them with meteoconditions. Only a very short part of the last penumbral phase was observed, while the inital part and the totality was not observed due to very dense clouds. The change in color and brightness during this phase was signaled. Meanwhile, there is an area of science where clouds are of great use and interest. This area is Atmospheric optics, while the science which study clouds is meteorology. Clouds in combination with Solar and Moon light could give rise to a variety of strange, rare and unobvious phenomena in the atmosphere (sky), sometimes confused with Unidentified Flying Objects (UFO). The importance of meteorology for astronomy and atmospheric optics is underlined and an invitation to astronomers to use unfavourable days for athmospheric observations was sent. The web address of the site by Les Cowley, designed for atmospheric optics phenomena is contained in the text of the entry.

  20. Large Databases in Astronomy (United States)

    Szalay, Alexander S.; Gray, Jim; Kunszt, Peter; Thakar, Anirudha; Slutz, Don

    The next-generation astronomy digital archives will cover most of the sky at fine resolution in many wavelengths, from X-rays through ultraviolet, optical, and infrared. The archives will be stored at diverse geographical locations. The intensive use of advanced data archives will enable astronomers to explore their data interactively. Data access will be aided by multidimensional spatial and attribute indices. The data will be partitioned in many ways. Small tag indices consisting of the most popular attributes will accelerate frequent searches. Splitting the data among multiple servers will allow parallel, scalable I/O and parallel data analysis. Hashing techniques will allow efficient clustering, and pair-wise comparison algorithms that should parallelize nicely. Randomly sampled subsets will allow debugging otherwise large queries at the desktop. Central servers will operate a data pump to support sweep searches touching most of the data. The anticipated queries will require special operators related to angular distances and complex similarity tests of object properties, like shapes, colors, velocity vectors, or temporal behaviors. These issues pose interesting data management challenges.

  1. Grab 'n' go astronomy

    CERN Document Server

    English, Neil


      Like everyone else, most amateur astronomers live busy lives. After a long day, the last thing you want as an observer is to have to lug out a large telescope and spend an hour getting it ready before it can be used. Maybe you are going somewhere sure to have dark skies, but you don’t necessarily want astronomy to dominate the trip. Or you are not quite committed to owning a large telescope, but curious enough to see what a smaller, portable setup can accomplish. These are times when a small “grab ’n’ go” telescope, or even a pair of binoculars, is the ideal in­strument. And this book can guide you in choosing and best utilizing that equipment.   What makes a telescope fall into the “grab ’n’ go” category? That’s easy – speed of setting up, ease of use, and above all, portability. This ambitious text is dedicated to those who love to or – because of their limited time – must observe the sky at a moment’s notice. Whether observing from the comfort of a backyard or while on busi...

  2. Gamma Ray Astronomy (United States)

    Wu, S. T.


    The project has progressed successfully during this period of performance. The highlights of the Gamma Ray Astronomy teams efforts are: (1) Support daily BATSE data operations, including receipt, archival and dissemination of data, quick-look science analysis, rapid gamma-ray burst and transient monitoring and response efforts, instrument state-of-health monitoring, and instrument commanding and configuration; (2) On-going scientific analysis, including production and maintenance of gamma-ray burst, pulsed source and occultation source catalogs, gamma-ray burst spectroscopy, studies of the properties of pulsars and black holes, and long-term monitoring of hard x-ray sources; (3) Maintenance and continuous improvement of BATSE instrument response and calibration data bases; (4) Investigation of the use of solid state detectors for eventual application and instrument to perform all sky monitoring of X-Ray and Gamma sources with high sensitivity; and (5) Support of BATSE outreach activities, including seminars, colloquia and World Wide Web pages. The highlights of this efforts can be summarized in the publications and presentation list.

  3. 30 CFR 77.703 - Grounding frames of stationary high-voltage equipment receiving power from ungrounded delta systems. (United States)


    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Grounding frames of stationary high-voltage equipment receiving power from ungrounded delta systems. 77.703 Section 77.703 Mineral Resources MINE SAFETY..., SURFACE COAL MINES AND SURFACE WORK AREAS OF UNDERGROUND COAL MINES Grounding § 77.703 Grounding frames of...

  4. Consumers' intention to use health recommendation systems to receive personalized nutrition advice

    NARCIS (Netherlands)

    S. Wendel (Sonja); B.G.C. Dellaert (Benedict); A. Ronteltap (Amber); H.C.M. van Trijp (Hans)


    textabstractBackground: Sophisticated recommendation systems are used more and more in the health sector to assist consumers in healthy decision making. In this study we investigate consumers' evaluation of hypothetical health recommendation systems that provide personalized nutrition advice. We

  5. Consumers’ intention to use health recommendation systems to receive personalized nutrition advice

    NARCIS (Netherlands)

    S. Wendel (Sonja); B.G.C. Dellaert (Benedict); A. Ronteltap (Amber); H.C.M. van Trijp (Hans)


    markdownabstract__Abstract__ __Background:__ Sophisticated recommendation systems are used more and more in the health sector to assist consumers in healthy decision making. In this study we investigate consumers' evaluation of hypothetical health recommendation systems that provide

  6. Consumers’ intention to use health recommendation systems to receive personalized nutrition advice

    NARCIS (Netherlands)

    Wendel, S.; Dellaert, B.G.C.; Ronteltap, A.; Trijp, van J.C.M.


    Background: Sophisticated recommendation systems are used more and more in the health sector to assist consumers in healthy decision making. In this study we investigate consumers' evaluation of hypothetical health recommendation systems that provide personalized nutrition advice. We examine

  7. Brian M. Kleiner receives Ralph H. Bogle Professor Fellowship in Industrial and Systems Engineering


    Owczarski, Mark


    Brian M. Kleiner, professor of industrial and systems engineering in the College of Engineering at Virginia Tech, has been named the Ralph H. Bogle Professor Fellow in Industrial and Systems Engineering by the Virginia Tech Board of Visitors.

  8. The Design and Evaluation of Transmit and Receive Antennas for an Ionospheric Communications Probe System: A. Multiband Dipole Antenna (United States)


    RECEIVE ANTENNAS FOR AN IONOSPHERIC COMMUNICATIONS PROBE SYSTEM: A. MULTIBAND DIPOLE ANTENNA by Sotirios Georgios Perros December, 1992 Thesis Advisor...PROBE SYSTEM: A. MULTIBANDDIPOLE ANTENNA 12 PERSONAL AUTHOR(S) PERROS , Sotirios Georgios 13a TYPE OF REPORT 13b TIME COVERED 14 DATE OF REPORT (Year...Sotirios Georgios Perros By Lieutenant, Hellenic Navy Dist! ibution I B.S., Hellenic Naval Academy, 1984 Availabiity des Avail i•,(lior Submitted in

  9. Astronomy Village Reaches for New Heights (United States)

    Croft, S. K.; Pompea, S. M.


    We are developing a set of complex, multimedia-based instructional modules emphasizing technical and scientific issues related to Giant Segmented Mirror Telescope project. The modules" pedagogy will be open-ended and problem-based to promote development of problem-solving skills. Problem- based-learning modules that emphasize work on open-ended complex real world problems are particularly valuable in illustrating and promoting a perspective on the process of science and engineering. Research in this area shows that these kinds of learning experiences are superior to more conventional student training in terms of gains in student learning. The format for the modules will be based on the award-winning multi-media educational Astronomy Village products that present students with a simulated environment: a mountaintop community surrounded by a cluster of telescopes, satellite receivers, and telecommunication towers. A number of "buildings" are found in the Village, such as a library, a laboratory, and an auditorium. Each building contains an array of information sources and computer simulations. Students navigate through their research with a mentor via imbedded video. The first module will be "Observatory Site Selection." Students will use astronomical data, basic weather information, and sky brightness data to select the best site for an observatory. Students will investigate the six GSMT sites considered by the professional site selection teams. Students will explore weather and basic site issues (e.g., roads and topography) using remote sensing images, computational fluid dynamics results, turbulence profiles, and scintillation of the different sites. Comparison of student problem solving with expert problem solving will also be done as part of the module. As part of a site selection team they will have to construct a case and present it on why they chose a particular site. The second module will address aspects of system engineering and optimization for a GSMT

  10. A Novel Mirror-Aided Non-imaging Receiver for Indoor 2x2 MIMO Visible Light Communication Systems

    KAUST Repository

    Park, Kihong


    Indoor visible light communication (VLC) systems are now possible because of advances in light emitting diode and laser diode technologies. These lighting technologies provide the foundation for multiple-input multiple-output (MIMO) data transmission through visible light. However, the channel matrix can be strongly correlated in indoor MIMO-VLC systems, preventing parallel data streams from being decoded. Here, in $2\\\\times 2$ MIMO-VLC systems, we describe a mirror diversity receiver (MDR) design that reduces the channel correlation by both blocking the reception of light from one specific direction and improving the channel gain from light from another direction by utilizing a double-sided mirror deployed between the receiver\\'s photodetectors. We report on the channel capacity of the MDR system and the optimal height of its mirrors in terms of maximum channel capacity. We also derived analytic results on the effect of rotation on MDR\\'s performance. Based on numerical and experimental results, we show that the double-sided mirror has both constructive and destructive effects on the channel matrix. Our design can be used with previously described non-imaging systems to improve the performance of indoor VLC systems.

  11. A Grand Vision for European Astronomy (United States)


    Today, and for the first time, astronomers share their global Science Vision for European Astronomy in the next two decades. This two-year long effort by the ASTRONET network of funding agencies, sponsored by the European Commission and coordinated by INSU-CNRS, underscores Europe's ascension to world leadership in astronomy and its will to maintain that position. It will be followed in just over a year by a prioritised roadmap for the observational facilities needed to implement the Vision. Implementation of these plans will ensure that Europe fully contributes to Mankind's ever deeper understanding of the wonders of our Universe. astronet logo "This is a great opportunity to help create a vibrant long-term future for astronomy and science" says Tim de Zeeuw (Leiden Observatory, The Netherlands) who led this community-wide effort. The ASTRONET Science Vision provides a comprehensive overview of the most important scientific questions that European astronomy should address in the next twenty years. The four key questions are the extremes of the Universe, from the nature of the dark matter and dark energy that comprise over 95% of the Universe to the physics of extreme objects such as black holes, neutron stars, and gamma-ray bursts; the formation of galaxies from the first seeds to our Milky Way; the formation of stars and planets and the origin of life; and the crucial question of how do we (and our Solar System) fit in the global picture. These themes reach well beyond the realm of traditional astronomy into the frontiers of physics and biology. The Vision identifies the major new facilities that will be needed to achieve these goals, but also stresses the need for parallel developments in theory and numerical simulations, high-performance computing resources, efficient astronomical data archiving and the European Virtual Observatory, as well as in laboratory astrophysics. "This report is a key input for the even more challenging task of developing a prioritised

  12. Inverse spiking filter based acquisition enhancement in software based global positioning system receiver

    Directory of Open Access Journals (Sweden)

    G. Arul Elango


    Full Text Available The lower visibility of the satellite in the acquisition stage of a GPS receiver under worst noisy situation leads to reacquisition of the data and thereby takes a longer time to obtain the first position fix. If the impulse noise affects the GPS signal, the conventional ways of acquiring the satellites do not guarantee to meet the minimum requirement of four satellites to find the user position. The performance of GPS receiver acquisition can be improved in the low SNR level using inverse spiking filtering technique. In the proposed method, the estimate of the desired GPS L1 signal corrupted by impulse noise (gn is obtained by the prediction error filter (hopt, which is the optimum inverse filter that reshapes the noisy signal (yn into a desired GPS signal (xn. In the proposed method, to detect the visible satellites under weak signal conditions the traditional differential coherent approach is combined with the inverse spiking filter method to increase the number of visible satellites and to avoid the reacquisition process. Montecarlo simulation is carried out to assess the performance of the proposed method for C/N0 of 20 dB-Hz and results indicate that the modified differential coherent method effectively excises the noise with 90% probability of detection. Subsequently tracking operation is also tested to confirm the acquisition performance by demodulating the navigation data successfully.

  13. Consumers’ intention to use health recommendation systems to receive personalized nutrition advice (United States)


    Background Sophisticated recommendation systems are used more and more in the health sector to assist consumers in healthy decision making. In this study we investigate consumers' evaluation of hypothetical health recommendation systems that provide personalized nutrition advice. We examine consumers' intention to use such a health recommendation system as a function of options related to the underlying system (e.g. the type of company that generates the advice) as well as intermediaries (e.g. general practitioner) that might assist in using the system. We further explore if the effect of both the system and intermediaries on intention to use a health recommendation system are mediated by consumers' perceived effort, privacy risk, usefulness and enjoyment. Methods 204 respondents from a consumer panel in the Netherlands participated. The data were collected by means of a questionnaire. Each respondent evaluated three hypothetical health recommendation systems on validated multi-scale measures of effort, privacy risk, usefulness, enjoyment and intention to use the system. To test the hypothesized relationships we used regression analyses. Results We find evidence that the options related to the underlying system as well as the intermediaries involved influence consumers' intention to use such a health recommendation system and that these effects are mediated by perceptions of effort, privacy risk, usefulness and enjoyment. Also, we find that consumers value usefulness of a system more and enjoyment less when a general practitioner advices them to use a health recommendation system than if they use it out of their own curiosity. Conclusions We developed and tested a model of consumers' intention to use a health recommendation system. We found that intermediaries play an important role in how consumers evaluate such a system over and above options of the underlying system that is used to generate the recommendation. Also, health-related information services seem to

  14. Consumers' intention to use health recommendation systems to receive personalized nutrition advice. (United States)

    Wendel, Sonja; Dellaert, Benedict G C; Ronteltap, Amber; van Trijp, Hans C M


    Sophisticated recommendation systems are used more and more in the health sector to assist consumers in healthy decision making. In this study we investigate consumers' evaluation of hypothetical health recommendation systems that provide personalized nutrition advice. We examine consumers' intention to use such a health recommendation system as a function of options related to the underlying system (e.g. the type of company that generates the advice) as well as intermediaries (e.g. general practitioner) that might assist in using the system. We further explore if the effect of both the system and intermediaries on intention to use a health recommendation system are mediated by consumers' perceived effort, privacy risk, usefulness and enjoyment. 204 respondents from a consumer panel in the Netherlands participated. The data were collected by means of a questionnaire. Each respondent evaluated three hypothetical health recommendation systems on validated multi-scale measures of effort, privacy risk, usefulness, enjoyment and intention to use the system. To test the hypothesized relationships we used regression analyses. We find evidence that the options related to the underlying system as well as the intermediaries involved influence consumers' intention to use such a health recommendation system and that these effects are mediated by perceptions of effort, privacy risk, usefulness and enjoyment. Also, we find that consumers value usefulness of a system more and enjoyment less when a general practitioner advices them to use a health recommendation system than if they use it out of their own curiosity. We developed and tested a model of consumers' intention to use a health recommendation system. We found that intermediaries play an important role in how consumers evaluate such a system over and above options of the underlying system that is used to generate the recommendation. Also, health-related information services seem to rely on endorsement by the medical sector

  15. Optical timing receiver for the NASA Spaceborne Ranging System. Part II: high precision event-timing digitizer

    Energy Technology Data Exchange (ETDEWEB)

    Leskovar, Branko; Turko, Bojan


    Position-resolution capabilities of the NASA Spaceborne Laser Ranging System are essentially determined by the timeresolution capabilities of its optical timing receiver. The optical timing receiver consists of a fast photoelectric device; (e.g., photomultiplier or an avalanche photodiode detector), a timing discriminator, a high-precision event-timing digitizer, and a signal-processing system. The time-resolution capabilities of the receiver are determined by the photoelectron time spread of the photoelectric device, the time walk and resolution characteristics of the timing discriminator, and the resolution of the event-timing digitizer. It is thus necessary to evaluate available fast photoelectronic devices with respect to the time-resolution capabilities, and to develop a very low time walk timing discriminator and a high-resolution event-timing digitizer to be used in the high-resolution spaceborne laser ranging system receiver. This part of the report describes the development of a high precision event-timing digitizer. The event-timing digitizer is basically a combination of a very accurate high resolution real time digital clock and an interval timer. The timing digitizer is a high resolution multiple stop clock, counting the time up to 131 days in 19.5 ps increments.

  16. Increased risk of hepatitis B virus reactivation in systemic lupus erythematosus patients receiving immunosuppressants: a retrospective cohort study. (United States)

    Lin, W T; Chen, Y M; Chen, D Y; Lan, J L; Chang, C S; Yeh, H Z; Yang, S S


    Objective We aimed to investigate risk of hepatitis B virus reactivation in systemic lupus erythematosus patients with different hepatitis B virus infection statuses receiving immunosuppressive therapy. Methods We retrospectively analyzed systemic lupus erythematosus patients with positive hepatitis B surface antigen or anti-hepatitis B core IgG antibody who underwent immunosuppressive therapies from January 2001 to December 2012 at a medical center in Taiwan for evidence of hepatitis B virus reactivation. Results During this period, 906 out of 3125 patients who were diagnosed with systemic lupus erythematosus received screening tests for hepatitis B virus. Thirty-eight patients were identified as hepatitis B surface antigen-positive. Fifteen of 38 (39.5%) hepatitis B surface antigen-positive patients developed hepatitis B virus reactivation, and 53.3% of these patients experienced severe hepatitis flare. Three of 157 hepatitis B surface antigen-negative/anti-hepatitis B core IgG antibody-positive patients (1.9%) experienced hepatitis B surface antigen seroreversion after immunosuppressive therapy. Five patients received prophylactic or preemptive antiviral therapy and none of them developed hepatitis B virus flares. A daily dose of prednisolone greater than 5 mg was a risk factor for hepatitis B reactivation by multivariate logistic analysis. Conclusions The risk of hepatitis B virus reactivation is high in lupus patients receiving immunosuppressive therapy. Antiviral prophylaxis or preemption can effectively reduce the incidence of hepatitis B virus reactivation in lupus patients.

  17. Implementation of Multi-standard Wireless Communication Receivers in a Heterogeneous Reconfigurable System-on-Chip

    NARCIS (Netherlands)

    Rauwerda, G.K.; Smit, Gerardus Johannes Maria; Heysters, P.M.

    Future mobile terminals become multi-mode communication systems. In order to handle different standards, we propose to perform baseband processing in heterogeneous reconfigurable hardware. Not only the baseband processing but also error decoding differs for every communication system. We already

  18. Abundance and fate of antibiotics and hormones in a vegetative treatment system receiving cattle feedlot runoff (United States)

    Vegetative treatment systems (VTS) have been developed and built as an alternative to conventional holding pond systems for managing run-off from animal feeding operations. Initially developed to manage runoff nutrients via uptake by grasses, their effectiveness at removing other runoff contaminant...

  19. Epitome of copernican astronomy & harmonies of the world

    CERN Document Server

    Kepler, Johannes, 1571-1630


    The brilliant German mathematician Johannes Kepler (1571-1630), one of the founders of modern astronomy, revolutionized the Copernican heliocentric theory of the universe with his three laws of motion: that the planets move not in circular but elliptical orbits, that their speed is greatest when nearest the sun, and that the sun and planets form an integrated system. This volume contains two of his most important works: The Epitome of Copernican Astronomy (books 4 and 5 of which are translated here) is a textbook of Copernican science, remarkable for the prominence given to physical astronomy and for the extension to the Jovian system of the laws recently discovered to regulate the motions of the Planets. Harmonies of the World (book 5 of which is translated here) expounds an elaborate system of celestial harmonies depending on the varying velocities of the planets.

  20. Astronomy Education Under Dark Skies (United States)

    Cecylia Molenda-Zakowicz, Joanna


    We have been providing professional support for the high school students and the astronomy teachers since 2007. Our efforts include organizing astronomy events that take from several hours, like, e.g., watching the transit of Venus, to several days, like the workshops organized in the framework of the projects 'School Workshops on Astronomy' (SWA) and 'Wygasz'.The SWA and Wygasz workshops include presentations by experts in astronomy and space science research, presentations prepared by students being supervised by those experts, hands-on interactive experience in the amateur astrophotography, various pencil-and-paper exercises, and other practical activities. We pay particular attention to familiarize the teachers and students with the idea and the necessity of protecting the dark sky. The format of these events allows also for some time for teachers to share ideas and best practices in teaching astronomy.All those activities are organized either in the Izera Dark-Sky Park in Poland or in other carefuly selected locations in which the beauty of the dark night sky can be appreciated.

  1. Astronomy cool women in space

    CERN Document Server

    Yasuda, Anita


    Head outside and look up. What do you see? At night you might see stars, the moon, the Milky Way, and planets! During the day all these things will still be there, but they'll be hidden by the bright light of the sun. Astronomy is the study of celestial objects and what's beyond the nebulous boundaries of space. In Astronomy: Cool Women in Space, young readers will be inspired by stories of women who have made great strides in a field that takes courage, persistence, and creativity to pursue. Most people have heard of Carl Sagan and Stephen Hawking, but have you heard of Maria Mitchell or Caroline Herschel? For many decades, female astronomers have been defining the field by making discoveries that changed the human relationship with space. Astronomy: Cool Women in Space will introduce young readers to three women who are bringing the science of astronomy forward and inspiring the next generation of astronomers. The primary sources, essentials questions, and knowledge connections within Astronomy: Cool Women ...

  2. Power collection reduction by mirror surface nonflatness and tracking error for a central receiver solar power system. (United States)

    McFee, R H


    The effects of random waviness, curvature, and tracking error of plane-mirror heliostats in a rectangular array around a central-receiver solar power system are determined by subdividing each mirror into 484 elements, assuming the slope of each element to be representative of the surface slope average at its location, and summing the contributions of all elements and then of all mirrors in the array. Total received power and flux density distribution are computed for a given sun location and set of array parameter values. Effects of shading and blocking by adjacent mirrors are included in the calculation. Alt-azimuth mounting of the heliostats is assumed. Representative curves for two receiver diameters and two sun locations indicate a power loss of 20% for random waviness, curvature, and tracking error of 0.1 degrees rms, 0.002 m(-1), and 0.5 degrees , 3sigma, respectively, for an 18.2-m diam receiver and 0.3 degrees rms, 0.005 m(-1), and greater than 1 degrees , respectively, for a 30.4-m diam receiver.

  3. A Community - Centered Astronomy Research Program (United States)

    Boyce, Pat; Boyce, Grady


    The Boyce Research Initiatives and Education Foundation (BRIEF) is providing semester-long, hands-on, astronomy research experiences for students of all ages that results in their publishing peer-reviewed papers. The course in astronomy and double star research has evolved from a face-to-face learning experience with two instructors to an online - hybrid course that simultaneously supports classroom instruction at a variety of schools in the San Diego area. Currently, there are over 65 students enrolled in three community colleges, seven high schools, and one university as well as individual adult learners. Instructional experience, courseware, and supporting systems were developed and refined through experience gained in classroom settings from 2014 through 2016. Topics of instruction include Kepler's Laws, basic astrometry, properties of light, CCD imaging, use of filters for varying stellar spectral types, and how to perform research, scientific writing, and proposal preparation. Volunteer instructors were trained by taking the course and producing their own research papers. An expanded program was launched in the fall semester of 2016. Twelve papers from seven schools were produced; eight have been accepted for publication by the Journal of Double Observations (JDSO) and the remainder are in peer review. Three additional papers have been accepted by the JDSO and two more are in process papers. Three college professors and five advanced amateur astronomers are now qualified volunteer instructors. Supporting tools are provided by a BRIEF server and other online services. The server-based tools range from Microsoft Office and planetarium software to top-notch imaging programs and computational software for data reduction for each student team. Observations are performed by robotic telescopes worldwide supported by BRIEF. With this success, student demand has increased significantly. Many of the graduates of the first semester course wanted to expand their

  4. Central Receiver Solar Thermal Power System, Phase 1. CDRL Item 2. Pilot Plant preliminary design report. Volume III, Book 1. Collector subsystem

    Energy Technology Data Exchange (ETDEWEB)

    Hallet, Jr., R. W.; Gervais, R. L.


    The central receiver system consists of a field of heliostats, a central receiver, a thermal storage unit, an electrical power generation system, and balance of plant. This volume discusses the collector field geometry, requirements and configuration. The development of the collector system and subsystems are discussed and the selection rationale outlined. System safety and availability are covered. Finally, the plans for collector portion of the central receiver system are reviewed.

  5. BOOK REVIEW: Astronomie und Anschaulichkeit. Die Bilder der populaeren Astronomie des 19. Jahrhunderts (United States)

    Duerbeck, H. W.; Utzt, S.


    Today, popularisation of science also means "pretty pictures": images that accompany articles in magazines and webpages, or are squeezed between the covers of so-called coffee-table books, and the reviewer pleads guilty to having added to this growing pile. But how did this "disease" came into existence? Susanne Utzt, a manager, journalist and student in the history of sciences, has dedicated her master thesis to the investigation of the growing influence of such pictures in the popularisation of astronomy. She has analyzed French and German popular texts by Arago, Guillemin, Flammarion, as well as Littrow, Maedler and Max Wilhelm Meyer that mainly appeared in the second half of the 19th century. Earlier astronomy books just had a few foldout pages with mathematical figures, as the author exemplifies by Littrow's first edition of "Die Wunder des Himmels" of 1834-36. But Flammarion with his "Astronomie Populaire", changed everything: 51 "art pages" and more than 300 figures in the text made it a true picture book, and about a third of Utzt's work is dedicated to its analysis. (In passing, it should be noted that the first 1880 edition of Flammarion's book did not yet contain the "art pages"; the author quotes such pages and text figures according to a German edition of 1907). Besides sober diagrams illustrating the solar system, and telescope drawings showing planetary surfaces and the structure of the solar photosphere, Flammarion includes poetic illustrations like a couple at the seashore at sunset; a scene showing dying Copernicus, already flanked by two angels, as he receives a copy of his De Revolutionibus; or a painting showing a flock of mammoths in an ancient landscape. In most cases, the images are chosen to illustrate the text, but sometimes the text "makes a detour" to permit the inclusion of a pretty picture. Flammarion's book contains drawings illustrating the sphericity of the earth, which appeared in almost identical form in Apian's Cosmography of

  6. W-026, Waste Receiving and Processing Facility data management system validation and verification report

    Energy Technology Data Exchange (ETDEWEB)

    Palmer, M.E.


    This V and V Report includes analysis of two revisions of the DMS [data management system] System Requirements Specification (SRS) and the Preliminary System Design Document (PSDD); the source code for the DMS Communication Module (DMSCOM) messages; the source code for selected DMS Screens, and the code for the BWAS Simulator. BDM Federal analysts used a series of matrices to: compare the requirements in the System Requirements Specification (SRS) to the specifications found in the System Design Document (SDD), to ensure the design supports the business functions, compare the discreet parts of the SDD with each other, to ensure that the design is consistent and cohesive, compare the source code of the DMS Communication Module with the specifications, to ensure that the resultant messages will support the design, compare the source code of selected screens to the specifications to ensure that resultant system screens will support the design, compare the source code of the BWAS simulator with the requirements to interface with DMS messages and data transfers relating to the BWAS operations.

  7. International Olympiad on Astronomy and Astrophysics (United States)

    Soonthornthum, B.; Kunjaya, C.


    The International Olympiad on Astronomy and Astrophysics, an annual astronomy and astrophysics competition for high school students, is described. Examples of problems and solutions from the competition are also given. (Contains 3 figures.)

  8. Student Attitudes Towards Public Funding Of Astronomy (United States)

    Stine, Peter


    Research in astronomy is strongly dependent on public (taxpayer) dollars. In this study we examine the attitudes of college students toward funding of astronomy projects. A survey was given to 269 college students prior to taking an introductory astronomy course. Students were given a short test designed to examine misconceptions about astronomy. They were then asked about their willingness to support public funding for astronomy projects. Students with fundamental misconceptions about mundane topics such as the cause of the seasons and phases of the moon were less than half as likely to support public funding of astronomy projects. Results are also reported showing the relationship between a willingness to fund projects and whether the students had experiences including reading books or magazines on astronomy, exposure to astronomy in high school, and using a telescope.

  9. Scientific literacy: astronomy at school (United States)

    Gangui, A.; Iglesias, M.; Quinteros, C.

    Models constructed by scientists to explain the world often incorporate their actual individual conceptions about different physical phenomena. Likewise, prospective teachers reach general science courses with preconstructed and consistent models of the universe surrounding them. In this project we present a series of basic questionings that make us reflect on the present situation of the teaching-learning relationship in astronomy within the framework of formal education for elementary school teachers. Our project main aims are: 1) to contribute to finding out the real learning situation of preservice elementary teachers, and 2) from these studies, to try and develop didactic tools that can contribute to improve their formal education in topics of astronomy. In spite of being of chief importance within the science teaching topics, mainly due to its interdisciplinarity and cultural relevance, researches in didactics of astronomy are not well represented in our research institutes. FULL TEXT IN SPANISH

  10. Astronomy Teaching Problems in Armenia (United States)

    Gyulzadyan, M. V.


    Astronomy, like any science, constantly develops unlimitedly approaching absolute objective truth; every moment of its accomplishments are due to the level of public welfare demands and culture. Armenia for centuries had a major contributor to the ancient as well as to the modern astronomy development. But it has been already a couple of years that the "Astronomy" course is not present at the schools of Armenia. Despite that fact, several schools put an effort to stress the importance of that subject by extracurricular groups trying to fill that gap. How this work is carried out and what results do we have? What can be done to increase the level of astronomical education as well as for its expansion?

  11. Uplink Performance Analysis of Multicell MU-MIMO Systems with ZF Receivers

    CERN Document Server

    Ngo, Hien Quoc; Duong, Trung Q; Larsson, Erik G


    We consider the uplink of a multicell multiuser multiple-input multiple-output system where the channel experiences both small and large-scale fading. The data detection is done by using the linear zero-forcing technique, assuming the base station (BS) has perfect channel state information. We derive exact closed-form expressions for the uplink rate, symbol error rate, and outage probability per user, as well as a lower bound on the achievable rate. This bound is very tight and becomes exact in the large-antenna limit. We further study the asymptotic performance of the system in the regimes of high signal-to-noise ratio (SNR), large number of antennas, and large number of users per cell. We show that, at high SNRs, the system is interference-limited and hence, we cannot improve the system performance by increasing the transmit power of each user. Instead, by increasing the number of BS antennas, the effects of interference and noise can be reduced, thereby improving the system performance. We further demonstr...

  12. Learning from the Starry Message: Using Galileo's "Sidereus Nuncius" in Introductory Astronomy Classes (United States)

    Wiesner, Matthew P.


    Every introductory astronomy class encounters Galileo during the course as the first man to systematically study the sky with a telescope. Every Astronomy 101 student meets Galileo as one of the major catalysts behind the shift from the Ptolemaic to the Copernican system and as one of the great minds behind the scientific method. But most of the…

  13. Spatial Thinking as the Dimension of Progress in an Astronomy Learning Progression (United States)

    Plummer, Julia D.


    The big idea of "celestial motion", observational astronomy phenomena explained by the relative position and motion of objects in the solar system and beyond, is central to astronomy in primary and secondary education. In this paper, I argue that students' progress in developing productive, scientific explanations for this class of…

  14. Discourse following award of Kepler Gold Medal. [Kepler Laws, planetary astronomy and physics, and Jupiter studies (United States)

    Kuiper, G. P.


    Kuiper briefly reviews Kepler's contributions to the field of planetary astronomy and physics, along with references to his own background in the study of stars, planets, and the solar system. He mentions his participation in NASA programs related to planetary astronomy. He concludes his remarks with thanks for being honored by the award of the Kepler Gold Medal.

  15. AstroJazz: Integrating Live Jazz and Astronomy Education (United States)

    Morrow, C. A.


    AstroJazz is an innovative public education program in astronomy that blends stunning imagery with live jazz music and a touch of humor to awaken the cosmic curiosity of both adults and children. The program debuted in February 2005 at the Fiske Planetarium on the campus of the University of Colorado, Boulder with an astronomer-chanteuse (the author), a pianist, bassist, drummer, and technical assistant who created dome effects to compliment the PowerPoint slides associated with each song. This AstroJazz quartet played ten songs, five original tunes (Look Up!, Are We Alone? Andromeda Affaire, StarMan Blues, Star Kissed)), and five standard tunes with lyrical twists toward astronomy & astrobiology (e.g. Stormy Weather - Solar Style and Stardust a la SETI.) The hour-long program also includes educational interludes where the astronomy chanteuse interacts with the audience, providing insights and perspective into the wonders of our universe. The performance program that is handed to all audience members contains additional "gee-whiz" facts and provides leads to websites like Astronomy Picture of the Day and that provide ongoing points of contact for public interest in astronomy. AstroJazz was very well received in its debut performance and now has several new opportunities to perform. Anecdotal evidence suggests that the AstroJazz program is engaging and educational for a very broad audience, including families with young children, world-class astronomers, and spouses of musicians who had never before been exposed to astronomy. This paper will describe the origins and intended evolution of AstroJazz, and offer a mini-sample of the music and slides used in the program. It will also discuss strategies for how the impact on audiences might be assessed.

  16. The Spectrum Landscape: Prospects for Terrestrial Radio Astronomy (United States)

    Liszt, Harvey Steven


    Radio astronomers work within broad constraints imposed by commercial and other non-astronomical uses of the radio spectrum, somewhat modified to accommodate astronomy’s particular needs through the provision of radio quiet zones, radio frequency allocations, coordination agreements and other devices of spectrum management. As radio astronomers increase the instantaneous bandwidth, frequency coverage and sensitivity of their instruments, these external constraints, and not the limitations of their own instruments, will increasingly be the greatest obstacles to radio astronomy’s ability to observe the cosmos from the surface of the Earth. Therefore, prospects for future radio astronomy operations are contingent on situational awareness and planning for the impact of non-astronomical uses of the radio frequency spectrum. New radio astronomy instruments will have to incorporate adaptive reactions to external developments, and radio astronomers should be encouraged to think in untraditional ways. Increased attention to spectrum management is one of these. In this talk I’ll recap some recent developments such as the proliferation of 76 – 81 GHz car radar and orbiting earth-mapping radars, either of which can burn out a radio astronomy receiver. I’ll summarize present trends for non-astronomical radio spectrum use that will be coming to fruition in the next decade or so, categorized into terrestrial fixed and mobile, airborne and space-borne uses, sub-divided by waveband from the cm to the sub-mm. I’ll discuss how they will impact terrestrial radio astronomy and the various ways in which radio astronomy should be prepared to react. Protective developments must occur both within radio astronomy’s own domain – designing, siting and constructing its instruments and mitigating unavoidable RFI – and facing outward toward the community of other spectrum users. Engagement with spectrum management is no panacea but it is an important means, and perhaps the only

  17. [Private health insurance systems, constitution and the right to receive an equitable health care]. (United States)

    Zúñiga F, Alejandra


    This paper analyzes the constitutional problems that the private health system has faced as a result of the recent decisions of the Constitutional Court and the Supreme Court of Chile in defense of the right to health care and nondiscrimination. It also reviews the comparative literature on health systems that have been successful in the task of reconciling the demands of equity and efficiency in the delivery of health care in the private health sector, in accordance with the constitutional principles of equality and nondiscrimination.

  18. Scalable Multifunction RF Systems: Combined vs. Separate Transmit and Receive Arrays

    NARCIS (Netherlands)

    Huizing, A.G.


    A scalable multifunction RF (SMRF) system allows the RF functionality (radar, electronic warfare and communications) to be easily extended and the RF performance to be scaled to the requirements of different missions and platforms. This paper presents the results of a trade-off study with respect to

  19. Instrument Landing System Localizer Receiver Performance in the Presence of Co-Channel Interference. (United States)


    test results were satisfactory; however, the test airplane was not equipped with an operable AN/ ARC -94 HF radio and AN/APS-121 weather radar, and...Navigational Aid Systems for Aircraft, Parie. France, November 14-18, 1977, Proceedings. (A79-13227 03-04) Paris, Federation des Industries Electriques et

  20. A new system for continuous and remote monitoring of patients receiving home mechanical ventilation (United States)

    Battista, L.


    Home mechanical ventilation is the treatment of patients with respiratory failure or insufficiency by means of a mechanical ventilator at a patient's home. In order to allow remote patient monitoring, several tele-monitoring systems have been introduced in the last few years. However, most of them usually do not allow real-time services, as they have their own proprietary communication protocol implemented and some ventilation parameters are not always measured. Moreover, they monitor only some breaths during the whole day, despite the fact that a patient's respiratory state may change continuously during the day. In order to reduce the above drawbacks, this work reports the development of a novel remote monitoring system for long-term, home-based ventilation therapy; the proposed system allows for continuous monitoring of the main physical quantities involved during home-care ventilation (e.g., differential pressure, volume, and air flow rate) and is developed in order to allow observations of different remote therapy units located in different places of a city, region, or country. The developed remote patient monitoring system is able to detect various clinical events (e.g., events of tube disconnection and sleep apnea events) and has been successfully tested by means of experimental tests carried out with pulmonary ventilators typically used to support sick patients.

  1. A study of the reliability of Stirling engines for distributed receiver systems (United States)

    Holtz, R. E.; Uherka, K. L.


    The objective of this study was to examine the reliability of existing and improved Stirling engine concepts for dispersed solar dish/electric applications in the 25 to 50 kW sub e range. Five current kinematic Stirling engine designs have the capability to meet or exceed the 32 percent system efficiency goal of the DOE Solar Thermal Program. Experience with the Vanguard Solar-Dish/Stirling Engine module demonstrated that the 32 percent efficiency goal is realistic, but that improved Stirling engine reliability is necessary for successful implementation of dispersed solar power systems. A review of historical Stirling engine data illustrated that the three major reliability issues with kinematic Stirling engines are the piston-rod seals, engine hot parts and power control/drive systems. A specific kinematic engine concept that appears to have the potential for meeting the 50,000-hour operating lifetime requirement of solar power systems has a pressurized crankcase to reduce piston-rod seal problems, an indirectly heated hot-end section using heat pipes to smooth out temperature gradients in the heater tubes, and a variable-angle swashplate for power control. Further development efforts are required to establish reliability and validate performance goals of these engine concepts.

  2. A study of the reliability of Stirling engines for distributed receiver systems

    Energy Technology Data Exchange (ETDEWEB)

    Holtz, R.E.; Uherka, K.L.


    The objective of this study was to examine the reliability of existing and improved Stirling engine concepts for dispersed solar dish/electric applications in the 25--50 kW/sub e/ range. Five current kinematic Stirling engine designs have the capability to meet or exceed the 32% system efficiency goal of the DOE Solar Thermal Program. Experience with the Vanguard Solar-Dish/Stirling Engine module demonstrated that the 32% efficiency goal is realistic, but that improved Stirling engine reliability is necessary for successful implementation of dispersed solar power systems. A review of historical Stirling engine data illustrated that the three major reliability issues with kinematic Stirling engines are the piston-rod seals, engine hot parts and power control/drive systems. A specific kinematic engine concept that appears to have the potential for meeting the 50,000-hour operating lifetime requirement of solar power systems has a pressurized crankcase to reduce piston-rod seal problems, an indirectly heated hot-end section using heat pipes to smooth out temperature gradients in the heater tubes, and a variable-angle swashplate for power control. Further development efforts are required to establish reliability and validate performance goals of these engine concepts. 30 refs., 13 figs., 8 tabs.

  3. Research of descriptions of collinear aerial receiving system ADS-B by numeral methods

    Directory of Open Access Journals (Sweden)

    В. П. Харченко


    Full Text Available Calculations of electric field intensity and directional diagrammes for colinear antennas using a method of moments in the framework of two program complexes are carried out. Comparison has shown high level of results coincidence. The sample of the antenna which is used in operating system for reception of ADS-B signals from airborne transponders is constructed

  4. Analysis and Compensation of Transmitter and Receiver I/Q Imbalances in Space-Time Coded Multiantenna OFDM Systems

    Directory of Open Access Journals (Sweden)

    Zou Yaning


    Full Text Available Abstract The combination of orthogonal frequency division multiplexing (OFDM and multiple-input multiple-output (MIMO techniques has been widely considered as the most promising approach for building future wireless transmission systems. The use of multiple antennas poses then big restrictions on the size and cost of individual radio transmitters and receivers, to keep the overall transceiver implementation feasible. This results in various imperfections in the analog radio front ends. One good example is the so-called I/Q imbalance problem related to the amplitude and phase matching of the transceiver I and Q chains. This paper studies the performance of space-time coded (STC multiantenna OFDM systems under I/Q imbalance, covering both the transmitter and the receiver sides of the link. The challenging case of frequency-selective I/Q imbalances is assumed, being an essential ingredient in future wideband wireless systems. As a practical example, the Alamouti space-time coded OFDM system with two transmit and M receive antennas is examined in detail and a closed-form solution for the resulting signal-to-interference ratio (SIR at the detector input due to I/Q imbalance is derived. This offers a valuable analytical tool for assessing the I/Q imbalance effects in any STC-OFDM system, without lengthy data or system simulations. In addition, the impact of I/Q imbalances on the channel estimation in the STC-OFDM context is also analyzed analytically. Furthermore, based on the derived signal models, a practical pilot-based I/Q imbalance compensation scheme is also proposed, being able to jointly mitigate the effects of frequency-selective I/Q imbalances as well as channel estimation errors. The performance of the compensator is analyzed using extensive computer simulations, and it is shown to virtually reach the perfectly matched reference system performance with low pilot overhead.

  5. Analysis and Compensation of Transmitter and Receiver I/Q Imbalances in Space-Time Coded Multiantenna OFDM Systems

    Directory of Open Access Journals (Sweden)

    Yaning Zou


    Full Text Available The combination of orthogonal frequency division multiplexing (OFDM and multiple-input multiple-output (MIMO techniques has been widely considered as the most promising approach for building future wireless transmission systems. The use of multiple antennas poses then big restrictions on the size and cost of individual radio transmitters and receivers, to keep the overall transceiver implementation feasible. This results in various imperfections in the analog radio front ends. One good example is the so-called I/Q imbalance problem related to the amplitude and phase matching of the transceiver I and Q chains. This paper studies the performance of space-time coded (STC multiantenna OFDM systems under I/Q imbalance, covering both the transmitter and the receiver sides of the link. The challenging case of frequency-selective I/Q imbalances is assumed, being an essential ingredient in future wideband wireless systems. As a practical example, the Alamouti space-time coded OFDM system with two transmit and M receive antennas is examined in detail and a closed-form solution for the resulting signal-to-interference ratio (SIR at the detector input due to I/Q imbalance is derived. This offers a valuable analytical tool for assessing the I/Q imbalance effects in any STC-OFDM system, without lengthy data or system simulations. In addition, the impact of I/Q imbalances on the channel estimation in the STC-OFDM context is also analyzed analytically. Furthermore, based on the derived signal models, a practical pilot-based I/Q imbalance compensation scheme is also proposed, being able to jointly mitigate the effects of frequency-selective I/Q imbalances as well as channel estimation errors. The performance of the compensator is analyzed using extensive computer simulations, and it is shown to virtually reach the perfectly matched reference system performance with low pilot overhead.

  6. Advances in astronomy and astrophysics

    CERN Document Server

    Kopal, Zdenek


    Advances in Astronomy and Astrophysics, Volume 4 brings together numerous research works on different aspects of astronomy and astrophysics. This volume is composed of five chapters, and starts with a description of objective prism and its application in space observations. The next chapter deals with the possibilities of deriving reliable models of the figure, density distribution, and gravity field of the Moon based on data obtained through Earth-bound telescopes. These topics are followed by a discussion on the ideal partially relativistic, partially degenerate gas in an exact manner. A ch

  7. Multiverso: Rock'n'Astronomy (United States)

    Caballero, J. A.


    In the last few years, there have been several projects involving astronomy and classical music. But have a rock band ever appeared at a science conference or an astronomer at a rock concert? We present a project, Multiverso, in which we mix rock and astronomy, together with poetry and video art (Caballero, 2010). The project started in late 2009 and has already reached tens of thousands people in Spain through the release of an album, several concert-talks, television, radio, newspapers and the internet.

  8. Advances in astronomy and astrophysics

    CERN Document Server

    Kopal, Zdenek


    Advances in Astronomy and Astrophysics, Volume 2 brings together numerous research works on different aspects of astronomy and astrophysics. This volume is composed of six chapters and begins with a summary of observational record on twilight extensions of the Venus cusps. The next chapter deals with the common and related properties of binary stars, with emphasis on the evaluation of their cataclysmic variables. Cataclysmic variables refer to an object in one of three classes: dwarf nova, nova, or supernova. These topics are followed by discussions on the eclipse phenomena and the eclipses i

  9. Astronomy, space science and geopolitics (United States)

    Courvoisier, Thierry J.-L.


    Astronomy has played a major part in the development of civilisations, not only through conceptual developments, but most importantly through the very practical gains obtained through the observation of Sun, Moon planets and stars. Space sciences, including astronomy, have also played a major rôle in the development of modern societies, as an engine for most subsequent space technology developments. Present trends tend to decrease the rôle of science in space development. This trend should be reversed to give modern ``societies'' their independence in space-related matters that permeate the lives of all inhabitants of the Earth.

  10. Astronomy and Shakespeare's Hamlet. (United States)

    Usher, P. D.


    Payne-Gaposchkin and others have suggested that Hamlet shows evidence of the Bard's awareness of the astronomical revolutions of the sixteenth century. I summarize major arguments and note that the play's themes recur in modern astronomy teaching and research: (1) The play amounts to a redefinition of universal order and humankind's position in it. (2) There is interplay between appearance and reality. Such a contrast is commonplace wherever superficial celestial appearances obscure underlying physical realities, the nature of which emerge as the tale unfolds. (3) The outermost sphere of the Ptolemaic and Copernican models seems to encase humanity, who are liberated by the reality of Digges' model and the implications advanced by Bruno. Similarly the oppressiveness of the castle interior is relieved by the observing platform which enables the heavens to be viewed in their true light. (4) Hamlet could be bounded in a nut-shell and count himself a king of infinite space, were it not that he has bad dreams. These concern the subversiveness of the new doctrine, for Hamlet refers to the infinite universe only hypothetically and in the presence of Rosencrantz and Guildenstern, who are named for relatives of the Danish astronomer Brahe. (5) Hamlet, and Brahe and Bruno, have connections to the university at Wittenberg, as does the Copernican champion Rheticus. (6) Ways are needed to reveal both the truths of nature, and the true nature of Danish royalty. Those unaccustomed to science think that there is madness in Hamlet's method. In particular, `doubt' is advanced as a methodological principle of inquiry. (7) The impression of normalcy and propriety in the upper reaches of society is like the false impression of an encapsulating universe. In Hamlet this duality is dramatized tragically, whereas in King John (cf. BAAS 27, 1325, 1995) it is not; for by 1601 when the writing of Hamlet was probably completed, Shakespeare would have known of the martyrdom of Bruno the previous

  11. Indian Astronomy: The Missing Link in Eurocentric History of Astronomy (United States)

    Haque, Shirin; Sharma, Deva


    A comprehensive history of Astronomy should show in reasonable chronological order, the contributions from wherever they arise in the world, once they are reliably documented. However, the authors note that consistently, the extremely rich contributions from Ancient Indian scholars like Aryabatha and Bhramagupta are omitted in Eurocentric…

  12. Blazing the Trail for Astronomy Education Research (United States)

    Bailey, Janelle M.; Lombardi, Doug


    Education research has long considered student learning of topics in astronomy and the space sciences, but astronomy education research as a sub-field of discipline-based education research is relatively new. Driven by a growing interest among higher education astronomy educators in improving the general education, introductory science survey…

  13. Astronomy Education Project for Guangdong High Schools

    Indian Academy of Sciences (India)


    Jan 27, 2016 ... Guangdong province is an active area in China for astronomy education and popularization. The current status and problems of astronomy education in high schools are reviewed. To tackle these problems, an astronomy education project for high school teachers and students was initiated by Guangzhou ...

  14. Design of pilot channel tracking loop Systems for high sensitivity Galileo receivers


    Kassabian, Nazelie


    Global Navigation Satellite Systems (GNSS) have been in the center stage of the recent technological upheaval that has been initiated by the rise of smartphones in the last decade. This is clearly reflected in the development of many applications based on GNSS technology as well as the emergence of multi-constellation GNSS with the launch of the first Galileo satellites at the end of the year 2011. GNSS does not only guarantee global positioning, navigation and timing services but also extend...

  15. Design and Implementation of a Pilot Signal Scanning Receiver for CDMA Personal Communication Services Systems


    Blankenship, T. Keith III


    In cellular and personal communications services (PCS) systems based on code division multiple access (CDMA), a pilot signal is used on the forward link for synchronization, coherent detection, soft handoff, maintaining orthogonality between base stations, and, in the future, position location. It is critical that the percentage of power allocated to the pilot signal transmitted by each base station be fixed properly to ensure the ability of the CDMA ne...

  16. Performance of a Constructed Wetland and Pretreatment System Receiving Potato Farm Wash Water

    Directory of Open Access Journals (Sweden)

    Vera Bosak


    Full Text Available Many potato processors require on-farm washing of potatoes, creating large quantities of wastewater that requires treatment, starting in the fall until the end of the potato storage period in mid-summer. We studied the treatment of wastewater from a potato farm in Ontario, Canada, using a system of pretreatment (sedimentation, aeration followed by a surface-flow wetland with a dense growth of cattails (Typha sp.. The raw wastewater had high average concentrations of 5-day biochemical oxygen demand (BOD5; 1113 mg·L−1, total suspended solids (TSS; 4338 mg·L−1, total nitrogen (TN; 311 mg·L−1 and total phosphorus (TP; 42.5 mg·L−1. Due to high influent loads, the pretreatment was enlarged during annual sediment cleaning at the end of Year 1 (Y1, which increased the hydraulic retention time and delayed the seasonal onset of wetland loading from winter in Y1 to spring in Year 2 (Y2. Total concentration reduction for the treatment system (pretreatment + wetland in Y2 was 96% BOD5, 99% TSS, 86% TN and 90% TP; and in Y1 was 79% BOD5, 97% TSS, 62% TN and 54% TP. Overall, the best treatment in both the pretreatment and the wetland was seen in spring months. The enlarged pretreatment system enabled seasonal loading of the wetland during the spring and summer, which facilitated improved treatment performance.

  17. Astronomical problems an introductory course in astronomy

    CERN Document Server

    Vorontsov-Vel'Yaminov, B A


    Astronomical Problems: An Introductory Course in Astronomy covers astronomical problems, together with a summary of the theory and the formula to be exercised. The book discusses the types of problems solved with the help of the celestial globe and how to solve astronomical problems. The text tackles problems on interpolation, the celestial sphere, systems of celestial coordinates, and culmination. Problems about the rising and setting of a heavenly body, precession, planetary movement, and parallax and aberration are also considered. The book presents problems about refraction, the apparent m

  18. Music of the heavens Kepler's harmonic astronomy

    CERN Document Server

    Stephenson, Bruce


    Valued today for its development of the third law of planetary motion, Harmonice mundi (1619) was intended by Kepler to expand on ancient efforts to discern a Creator's plan for the planetary system--an arrangement thought to be based on harmonic relationships. Challenging critics who characterize Kepler's theories of harmonic astronomy as ""mystical,"" Bruce Stephenson offers the first thorough technical analysis of the music the astronomer thought the heavens made, and the logic that led him to find musical patterns in his data. In so doing, Stephenson illuminates crucial aspects of Kepler'

  19. Physics and astronomy of the Moon

    CERN Document Server

    Kopal, Zdenek


    Physics and Astronomy of the Moon focuses on the application of principles of physics in the study of the moon, including perturbations, equations, light scattering, and photometry. The selection first offers information on the motion of the moon in space and libration of the moon. Topics include Hill's equations of motion, non-solar perturbations, improved lunar ephemeris, optical and physical libration of the moon, and adjustment of heliometric observations of the moon's libration. The text then elaborates on the dynamics of the earth-moon system, photometry of the moon, and polarization of

  20. Antibiotic resistance genes in municipal wastewater treatment systems and receiving waters in Arctic Canada

    DEFF Research Database (Denmark)

    Neudorf, Kara D.; Huang, Yan Nan; Ragush, Colin M.


    -term storage in WSPs benefitted removal of organic material and some ARGs. However, one WSP system showed evidence of the enrichment of sul1, sul2, mecA, tet(O) and qnr(S). Further research is needed to fully understand if these ARG releases pose a risk to human health, especially in the context of traditional......Domestic wastewater discharges may adversely impact arctic ecosystems and local indigenous people, who rely on being able to hunt and harvest food from their local environment. Therefore, there is a need to develop efficient wastewater treatment plants (WWTPs), which can be operated in remote...

  1. Discretionary decisions and disparities in receiving drug-eluting stents under a universal healthcare system: A population-based study.

    Directory of Open Access Journals (Sweden)

    Raymond N Kuo

    Full Text Available One of the main objectives behind the expansion of insurance coverage is to eliminate disparities in health and healthcare. However, researchers have not yet fully elucidated the reasons for disparities in the use of high-cost treatments among patients of different occupations. Furthermore, it remains unknown whether discretionary decisions made at the hospital level have an impact on the administration of high-cost interventions in a universal healthcare system. This study investigated the adoption of drug-eluting stents (DES versus bare metal-stents (BMS among patients in different occupations and income levels, with the aim of gauging the degree to which the inclination of health providers toward treatment options could affect treatment choices at the patient-level within a universal healthcare system.We adopted a cross-sectional observational study design using hierarchical modeling in conjunction with the population-based National Health Insurance database of Taiwan. Patients who received either a BMS or a DES between 2007 and 2010 were included in the study.During the period of study, 42,124 patients received a BMS (65.3% and 22,376 received DES (34.7%. Patients who were physicians or the family members of physicians were far more likely to receive DES (OR: 3.18, CI: 2.38-4.23 than were patients who were neither physicians nor in other high-status jobs (employers, other medical professions, or public service. Similarly, patients in the top 5% income bracket had a higher probability of receiving a DES (OR: 2.23, CI: 2.06-2.47, p 50% or between 25% and 50% was shown to be strongly associated with the selection of DESs (OR: 3.64 CI: 3.24-4.09 and OR: 2.16, CI: 2.01-2.33, respectively.Even under the universal healthcare system in Taiwan, socioeconomic disparities in the use of high-cost services remain widespread. Differences in the care received by patients of lower socioeconomic status may be due to the discretionary decisions of healthcare

  2. Fiber-Optic Coupled Lidar Receiver System to Measure Stratospheric Ozone (United States)

    Harper, David Brent; Elsayed-Ali, Hani


    The measurement of ozone in the atmosphere has become increasingly important over the past two decades. Significant increases of ozone concentrations in the lower atmosphere, or troposphere, and decreases in the upper atmosphere, or stratosphere, have been attributed to man-made causes. High ozone concentrations in the troposphere pose a health hazard to plants and animals and can add to global warming. On the other hand, ozone in the stratosphere serves as a protective barrier against strong ultraviolet (UV) radiation from the sun. Man-made CFC's (chlorofluorocarbons) act as a catalyst with a free oxygen atom and an ozone molecule to produce two oxygen molecules therefore depleting the protective layer of ozone in the stratosphere. The beneficial and harmful effects of ozone require the study of ozone creation and destruction processes in the atmosphere. Therefore, to provide an accurate model of these processes, an ozone lidar system must be able to be used frequently with as large a measurement range as possible. Various methods can be used to measure atmospheric ozone concentrations. These include different airborne and balloon measurements, solar occulation satellite techniques, and the use of lasers in lidar (high detection and ranging,) systems to probe the atmosphere. Typical devices such as weather balloons can only measure within the direct vicinity of the instrument and are therefore used infrequently. Satellites use solar occulation techniques that yield low horizontal and vertical resolution column densities of ozone.

  3. NASA Stratospheric Observatory For Infrared Astronomy (SOFIA) Airborne Astronomy Ambassador Program Evaluation Results To Date (United States)

    Harman, Pamela K.; Backman, Dana E.; Clark, Coral


    SOFIA is an airborne observatory, capable of making observations that are impossible for even the largest and highest ground-based telescopes, and inspires instrumention development.SOFIA is an 80% - 20% partnership of NASA and the German Aerospace Center (DLR), consisting of a modified Boeing 747SP aircraft carrying a diameter of 2.5 meters (100 inches) reflecting telescope. The SOFIA aircraft is based at NASA Armstrong Flight Research Center, Building 703, in Palmdale, California. The Science Program Office and Outreach Office is located at NASA Ames Research center. SOFIA is one of the programs in NASA's Science Mission Directorate, Astrophysics Division.SOFIA will be used to study many different kinds of astronomical objects and phenomena, including star birth and death, formation of new solar systems, identification of complex molecules in space, planets, comets and asteroids in our solar system, nebulae and dust in galaxies, and ecosystems of galaxies.Airborne Astronomy Ambassador Program:The SOFIA Education and Communications program exploits the unique attributes of airborne astronomy to contribute to national goals for the reform of science, technology, engineering, and math (STEM) education, and to the elevation of public scientific and technical literacy.SOFIA’s Airborne Astronomy Ambassadors (AAA) effort is a professional development program aspiring to improve teaching, inspire students, and inform the community. To date, 55 educators from 21 states; in three cohorts, Cycles 0, 1 and 2; have completed their astronomy professional development and their SOFIA science flight experience. Cycle 3 cohort of 28 educators will be completing their flight experience this fall. Evaluation has confirmed the program’s positive impact on the teacher participants, on their students, and in their communities. Teachers have incorporated content knowledge and specific components of their experience into their curricula, and have given hundreds of presentations and

  4. A Novel WPT System Based on Dual Transmitters and Dual Receivers for High Power Applications: Analysis, Design and Implementation

    Directory of Open Access Journals (Sweden)

    Yong Li


    Full Text Available Traditional Wireless Power Transfer (WPT systems only have one energy transmission path, which can hardly meet the power demand for high power applications, e.g., railway applications (electric trains and trams, etc. due to the capacity constraints of power electronic devices. A novel WPT system based on dual transmitters and dual receivers is proposed in this paper to upgrade the power capacity of the WPT system. The reliability and availability of the proposed WPT system can be dramatically improved due to the four energy transmission paths. A three-dimensional finite element analysis (FEA tool ANSYS MAXWELL (ANSYS, Canonsburg, PA, USA is adopted to investigate the proposed magnetic coupling structure. Besides, the effects of the crossing coupling mutual inductances among the transmitters and receivers are analyzed. It shows that the same-side cross couplings will decrease the efficiency and transmitted power. Decoupling transformers are employed to mitigate the effects of the same-side cross couplings. Meanwhile, the output voltage in the secondary side can be regulated at its designed value with a fast response performance, and the system can continue work even with a faulty inverter. Finally, a scale-down experimental setup is provided to verify the proposed approach. The experimental results indicate that the proposed method could improve the transmitted power capacity, overall efficiency and reliability, simultaneously. The proposed WPT structure is a potential alternative for high power applications.

  5. Python in Astronomy 2016 Unproceedings (United States)

    Robitaille, Thomas; Cruz, Kelle; Greenfield, Perry; Jeschke, Eric; Juric, Mario; Mumford, Stuart; Prescod-Weinstein, Chanda; Sosey, Megan; Tollerud, Erik; VanderPlas, Jake; Ford, Jes; Foreman-Mackey, Dan; Jenness, Tim; Aldcroft, Tom; Alexandersen, Mike; Bannister, Michele; Barbary, Kyle; Barentsen, Geert; Bennett, Samuel; Boquien, Médéric; Campos Rozo, Jose Ivan; Christe, Steven; Corrales, Lia; Craig, Matthew; Deil, Christoph; Dencheva, Nadia; Donath, Axel; Douglas, Stephanie; Ferreira, Leonardo; Ginsburg, Adam; Goldbaum, Nathan; Gordon, Karl; Hearin, Andrew; Hummels, Cameron; Huppenkothen, Daniela; Jennings, Elise; King, Johannes; Lawler, Samantha; Leonard, Andrew; Lim, Pey Lian; McBride, Lisa; Morris, Brett; Nunez, Carolina; Owen, Russell; Parejko, John; Patel, Ekta; Price-Whelan, Adrian; Ruggiero, Rafael; Sipocz, Brigitta; Stevens, Abigail; Turner, James; Tuttle, Sarah; Yanchulova Merica-Jones, Petia; Yoachim, Peter


    This document provides proceedings for unconference sessions as well as hacks/sprints which took place at the Python in Astronomy 2016 workshop, which was held at the University of Washington eScience Institute in Seattle from March 21st to 25th 2016.

  6. Service Learning in Introductory Astronomy (United States)

    Orleski, Michael


    Service learning is a method of instruction where the students in a course use the course's content in a service project. The service is included as a portion of the students' course grades. During the fall semester 2010, service learning was incorporated into the Introduction to Astronomy course at Misericordia University. The class had eight…

  7. Network for Astronomy School Education (United States)

    Deustua, Susana E.; Ros, R. M.; Garcia, B.


    The Network for Astronomy School Education Project (NASE) was developed in response to the IAU's most recent 10 Years Strategic Plan to increase the efforts of the IAU in schools. NASE's mission is to stimulate teaching astronomy in schools, through professional development of primary and secondary school science teachers in developing and emerging countries. NASE's organizational principle is to build capacity by providing courses for three years in cooperation with a Local Organizing Committee (Local NASE Group). The Local NASE Group consists of 6-8 local university professors and education professional who will promote astronomy activities and organize future courses in subsequent years in their region of their country. NASE philosophy is to introduce low-tech astronomy, and has thus developed an a suite of activities that can be carried out with inexpensive, quotidian materials. Supporting these activities is a text for teachers, plus a complete set of instructional materials for each topic. These materials are available in English and Spanish, with future editions available in Chinese and Portuguese. We describe and discuss NASE activities in Central and South America from 2009 to the present.

  8. Music to teach astronomy by (United States)

    Möbius, Eberhard


    Author shares his technique of aligning music selections with his introductory astronomy syllabus. He begins class with a music selection as an introduction to the concepts covered in class. List of 40 music titles and composers used can be downloaded from

  9. Utrecht and Galactic Radio Astronomy

    NARCIS (Netherlands)

    van Woerden, H.

    Important roles in early Dutch Galactic radio astronomy were played by several Utrecht astronomers: Van de Hulst, Minnaert and Houtgast. The poster announcing the conference contained a number of pictures referring to scientific achievements of the Astronomical Institute Utrecht. One of these

  10. Exchange of astronomy teaching experiences (United States)

    Ros, Rosa M.

    The Working Group of the European Association for Astronomy Education responsible for Teacher Training organises an annual Summer School for teachers under expert guidance. For a week the teachers participating can exchange experiences, increase their knowledge and discuss different ideas and perspectives. In general, the instructors are professional astronomers, professors and teachers from different countries. The papers presented offer very practical activities, paying special attention to didactic aspects, and take the form of general lectures to all 40 participants and workshops to reduced groups of 20 participants. There are also day and night observations, without expensive equipment or complicated procedures, that are easy to set up and based on topics that it is possible to use in the classroom. The Summer Schools promote a scientific astronomical education at all levels of astronomy teaching, reinforce the link between professional astronomers and teachers with experience of teaching astronomy, allow debates among the participants on their pedagogical activities already carried out in their own classroom and help them to organise activities outside it. Astronomy teachers need special training, access to specific research, to new educational materials and methods and the opportunity to exchange experiences. All these things are provided by the Summer School.

  11. Astronomy Education Challenges in Egypt (United States)

    El Fady Beshara Morcos, Abd


    One of the major challenges in Egypt is the quality of education. Egypt has made significant progress towards achieving the Education for All and the Millennium Development Goals (MDGs). Many associations and committees as education reform program and education support programs did high efforts in supporting scientific thinking through the scientific clubs. The current state of astronomical education in Egypt has been developed. Astronomy became a part in both science and geography courses of primary, preparatory and secondary stages. Nowadays the Egyptian National Committee for Astronomy, put on its shoulders the responsibility of revising of astronomy parts in the education courses, beside preparation of some training programs for teachers of different stages of educations, in collaboration with ministry of education. General lectures program has been prepared and started in public places , schools and universities. Many TV and Radio programs aiming to spread astronomical culture were presented. In the university stage new astronomy departments are established and astrophysics courses are imbedded in physics courses even in some private universities.

  12. Astronomy and astronomers in Jules Verne's novels (United States)

    Crovisier, Jacques


    Almost all the Voyages Extraordinaires written by Jules Verne refer to astronomy. In some of them, astronomy is even the leading theme. However, Jules Verne was basically not learned in science. His knowledge of astronomy came from contemporaneous popular publications and discussions with specialists among his friends or his family. In this article, I examine, from the text and illustrations of his novels, how astronomy was perceived and conveyed by Jules Verne, with errors and limitations on the one hand, with great respect and enthusiasm on the other hand. This informs us on how astronomy was understood by an ``honnête homme'' in the late 19th century.

  13. Design of high–order HTS dual–band bandpass filters with receiver subsystem for future mobile communication systems

    Energy Technology Data Exchange (ETDEWEB)

    Sekiya, N., E-mail:


    Highlights: • We have developed two high-order HTS dual-band BPFs with a receiver subsystem for future mobile communication systems. • We developed a method for flexibly adjusting the coupling coefficient for the two passbands. • We demonstrated an HTS dual-band BPF receiver subsystem that uses a pulse tube cryocooler and a wideband LNA. • The proposed BPF is evaluated by simulation and measurement with good agreement. - Abstract: We have developed two high-order high-temperature superconducting (HTS) dual-band bandpass filters (BPFs) with a receiver subsystem for future mobile communication systems. They feature stub-loaded hair-pin resonators with two types of microstrip lines between them. One has a six-pole design, and the other has an eight-pole design. Both were designed to operate at 2.15 GHz with a 43-MHz (2%) bandwidth for the lower passband and at 3.50 GHz with a 70-MHz (2%) bandwidth for the upper one. They were fabricated using YBa{sub 2}Cu{sub 3}O{sub y} thin film on a CeO{sub 2}-bufferd r-Al{sub 2}O{sub 3} substrate. The measured results for both filters agree well with the simulated ones. The HTS dual-band BPF receiver subsystem uses a pulse tube cryocooler and a wideband low noise amplifier (LNA). We measured the frequency response of the six-pole dual-band BPF with and without a wideband LNA with a gain of 10 dB. The measured return losses were close.

  14. Incidence of liver injury among cancer patients receiving chemotherapy in an integrated health system. (United States)

    Ulcickas Yood, Marianne; Bortolini, Michele; Casso, Deborah; Beck, Jean G; Oliveria, Susan A; Wells, Karen E; Woodcroft, Kimberley J; Wang, Lisa I


    Using liver laboratory tests (LLTs), Hy's law is a method used to identify drug-induced liver injury (DILI), after excluding other causes. Elevated LLTs in chemotherapy-exposed patients may result from tumor effects or comorbidities. This study evaluated incidence of Hy's law in chemotherapy-treated cancer patients. We identified breast, colorectal, and lung cancer patients diagnosed in 1 January 2000 to 31 December 2007 at a Midwestern health system. Using automated data, potential Hy's law (PHL) cases were defined by patterns of elevated LLTs suggestive of DILI. Among those treated with chemotherapy, we excluded PHL patients with pre-existing conditions that could cause liver injury, producing a cohort meeting Hy's law criteria, according to automated data. Medical record review, conducted among these automated data-derived Hy's law patients, further excluded those with causes of liver injury other than chemotherapy. Using automated data, among chemotherapy-exposed patients (N = 2788), 91 (3.3%) met PHL criteria using LLTs and 64 (2.3%) met Hy's law after excluding underlying liver injury using the International Classification of Diseases, 9th Revision codes. After a medical record review, 62 of 64 patients qualifying as Hy's law through automated data had other potential causes, leaving two patients (0.07%; 95%CI: 0.01-0.24%) with chemotherapy as a likely alternative cause of liver injury. Abnormal LLTs are common in chemotherapy-treated patients. Medical record review showed that the incidence of Hy's law events is rare. These data provide context for evaluating DILI in clinical trials and postmarketing surveillance of anticancer therapies, understanding that automated data alone may substantially overestimate the number of Hy's law cases. Copyright © 2015 John Wiley & Sons, Ltd.

  15. Integrating Astronomy with Elementary Non-Science Curricula (United States)

    Bobrowsky, M.


    A workshop was developed for elementary school teachers to enhance students' understanding of astronomy during the formative years of elementary school by incorporating astronomy into various non-science curricula. Educational material was compiled for teachers and students and training was provided for the teachers in the form of a workshop where both information and hands-on activities were disseminated. In addition, we are producing a video tape from the workshop which will be available not only to those who attended the workshop but to other teachers as well. A useful ``multiplier effect" in this project came from our focus on a school that was hosting a group of teachers in training. After these teachers receive certification, they will end up working in all different schools, thereby reaching large numbers of students for many years. The non-scientific subjects that we will connect to astronomy include history, music, art, language arts, social studies, and mathematics, as well as incidental subjects such as health and public safety. Support for this work was provided by NASA through grant number ED90024.01-94A from the Space Telescope Science Institute which is operated by the Association of Universities for Research in Astronomy Inc. under NASA Contract NAS5-26555.

  16. Research on teaching astronomy in the planetarium

    CERN Document Server

    Slater, Timothy F


    From a noted specialist in astronomy education and outreach, this Brief provides an overview of the most influential discipline-based science education research literature now guiding contemporary astronomy teaching. In recent years, systematic studies of effective and efficient teaching strategies have provided a solid foundation for enhancing college-level students’ learning in astronomy. Teaching astronomy and planetary science at the college-level was once best characterized as professor-centered, information-download lectures. Today, astronomy faculty are striving to drastically improve the learning environment by using innovative teaching approaches.  Uniquely, the authors have organized this book around strands of commonly employed astronomy teaching strategies to help readers, professors, and scholars quickly access the most relevant work while, simultaneously, avoiding the highly specialized, technical vocabulary of constructivist educational pedagogies unfamiliar to most astronomy professors. F...

  17. A Great Moment for Astronomy (United States)


    VLT First Light Successfully Achieved The European Southern Observatory announces that First Light has been achieved with the first VLT 8.2-m Unit Telescope at the Paranal Observatory. Scientifically useful images have been obtained as scheduled, on May 25 - 26, 1998. A first analysis of these images convincingly demonstrates the exceptional potential of the ESO Very Large Telescope. Just one month after the installation and provisional adjustment of the optics, the performance of this giant telescope meets or surpasses the design goals, in particular as concerns the achievable image quality. Exposures lasting up to 10 minutes confirm that the tracking, crucial for following the diurnal rotation of the sky, is very accurate and stable. It appears that the concept developed by ESO for the construction of the VLT, namely an actively controlled, single thin mirror, yields a very superior performance. In fact, the angular resolution achieved even at this early stage is unequalled by any large ground-based telescope . The combination of large area and fine angular resolution will ultimately result in a sensitivity for point sources (e.g. stars), which is superior to any yet achieved by existing telescopes on Earth. The present series of images demonstrate these qualities and include some impressive first views with Europe's new giant telescope. After further optimization of the optical, mechanical and electronic systems, and with increasing operational streamlining, this telescope will be able to deliver unique astronomical data of the highest quality. The commissioning and science verification phases of the complex facility including instruments will last until April 1, 1999, at which time the first visiting astronomers will be received. The full significance of this achievement for astronomy will take time to assess. For Europe, this is a triumph of the collaboration between nations, institutions and industries. For the first time in almost a century, European

  18. Solar central receiver hybrid power system, Phase I. Volume 2. Conceptual design. Final technical report, October 1978-August 1979

    Energy Technology Data Exchange (ETDEWEB)



    The objectives of this study were to develop a hybrid power system design that (1) produces minimum cost electric power, (2) minimizes the capital investment and operating cost, (3) permits capacity displacement, (4) and achieves utility acceptance for market penetration. We have met the first three of these objectives and therefore believe that the fourth, utility acceptance, will become a reality. These objectives have been met by utilizing the Martin Marietta concept that combines the alternate central receiver power system design and a high-temperature salt primary heat transfer fluid and thermal storage media system with a fossil-fired nonsolar energy source. Task 1 reviewed the requirements definition document and comments and recommendations were provided to DOE/San Francisco. Task 2 consisted of a market analysis to evaluate the potential market of solar hybrid power plants. Twenty-two utilities were selected within nine regions of the country. Both written and verbal correspondence was used to assess solar hybrid power plants with respect to the utilities' future requirements and plans. The parametric analysis of Task 3 evaluated a wide range of subsystem configurations and sizes. These analyses included subsystems from the solar standalone alternate central receiver power system using high-temperature molten salt and from fossil fuel nonsolar subsystems. Task 4, selection of the preferred commerical system configuration, utilized the parametric analyses developed in Task 3 to select system and subsystem configurations for the commercial plant design. Task 5 developed a conceptual design of the selected commercial plant configuration and assessed the related cost and performance. Task 6 assessed the economics and performance of the selected configuration as well as future potential improvements or limitations of the hybrid power plants.

  19. Student Understanding of Gravity in Introductory College Astronomy (United States)

    Williamson, Kathryn E.; Willoughby, Shannon


    Twenty-four free-response questions were developed to explore introductory college astronomy students' understanding of gravity in a variety of contexts, including in and around Earth, throughout the solar system, and in hypothetical situations. Questions were separated into three questionnaires, each of which was given to a section of…

  20. Journal of Astrophysics and Astronomy | Indian Academy of Sciences

    Indian Academy of Sciences (India)


    Jan 27, 2016 ... Home; Journals; Journal of Astrophysics and Astronomy; Volume 30; Issue 3-4. Issue front cover thumbnail. Volume 30, Issue 3-4. September-December 2009, pages 133-210. pp 133-143. Close Separation Triple System QSO 1009-0252 with Discordant Redshifts: Is the Spectrum of One Component ...

  1. Journal of Astrophysics and Astronomy | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy; Volume 33; Issue 2. Issue front cover thumbnail. Volume 33, Issue 2. June 2012, pages 201-278. pp 201-211. Effect of Inhomogeneity of the Universe on a Gravitationally Bound Local System: A No-Go Result for Explaining the Secular Increase in the Astronomical ...

  2. The Astronomy Workshop: Web Tools for Astronomy Students at All Levels (United States)

    Hayes-Gehrke, Melissa N.; Hamilton, D.; Deming, G.


    The Astronomy Workshop ( is a collection of over 20 interactive web tools that were developed under the direction of Doug Hamilton for use in undergraduate classes and by the general public. The goal of the website is to encourage students to learn about astronomy by exploiting their fascination with the internet. Two of the tools, Scientific Notation and Solar System Collisions, have instructor materials available to facilitate their use in undergraduate, high school, and junior high classes. The Scientific Notation web tool allows students to practice conversion, addition/subtraction, and multiplication/division with scientific notation, while the Solar System Collisions web tool explores the effects of impacts on the Earth and other solar system bodies. Some web tools allow students to explore our own solar system (Solar System Visualizer) and the Sun's past and future history (The Life of the Sun), Others allow students to experiment with changes in the solar system, such as to the tilt of the Earth (Earth's Seasons) and changing the properties of the planets in the solar system (Build Your Own Solar System).

  3. Books Received

    Indian Academy of Sciences (India)

    VG Bhide. Shekhar Phatak and Associates. 1998, Rs.80. Books Received. Biotechnological Methods of. Pollution Control. S A Abbasi and E Ramasami. Universities Press. 1999, Rs.1S0. The Penguin India Career Guide,. Vol 2, The Scien~es. Usha Albuquerque. Penguin Books. 1996, Rs.250. Fixed Points. Yu A Shashldn.

  4. Books Received

    Directory of Open Access Journals (Sweden)

    Murat Akser


    Full Text Available In 2014 we have received a variety of books onc inema and media from these publishers: Bloomsbury Academic, Cambridge Scholars Publishing, Continuum, Edinburgh University Press, Focal Press, Intellect, Paradigm, Peter Lang, Routledge, University of California Press, Wayne State University Press.

  5. Books Received

    Indian Academy of Sciences (India)

    Books Received. Challenge and Thrill of Pre-College. Mathematics. V Krishnamurthy et al. New Age International. 1996, Rs.220. Mathematics for Science. S M Uppal and H M Humphreys. New Age International. 1996, Rs.17S. Physics for Engineers. M R Srinivasan. New Age Publications. 1996. Statement about ownership ...

  6. Autonomous Acoustic Receiver System (United States)

    Federal Laboratory Consortium — FUNCTION: Collects underwater acoustic data and oceanographic data. Data are recorded onboard an ocean buoy and can be telemetered to a remote ship or shore station...

  7. Astronomy in Aboriginal culture (United States)

    Bhathal, Ragbir


    In all probability, long before other civilizations had named the celestial objects in the night sky, the indigenous people of Australia had not only given them names but had also built an astronomical knowledge system which they incorporated into their social, cultural and religious life. Their socio-cultural astronomical knowledge system both assists and clashes with Australia's legal system, which is based on English law.

  8. On Fast Post-Processing of Global Positioning System Simulator Truth Data and Receiver Measurements and Solutions Data (United States)

    Kizhner, Semion; Day, John H. (Technical Monitor)


    Post-Processing of data related to a Global Positioning System (GPS) simulation is an important activity in qualification of a GPS receiver for space flight. Because a GPS simulator is a critical resource it is desirable to move off the pertinent simulation data from the simulator as soon as a test is completed. The simulator data files are usually moved to a Personal Computer (PC), where the post-processing of the receiver logged measurements and solutions data and simulated data is performed. Typically post-processing is accomplished using PC-based commercial software languages and tools. Because of commercial software systems generality their general-purpose functions are notoriously slow and more than often are the bottleneck problem even for short duration experiments. For example, it may take 8 hours to post-process data from a 6-hour simulation. There is a need to do post-processing faster, especially in order to use the previous test results as feedback for a next simulation setup. This paper demonstrates that a fast software linear interpolation algorithm is applicable to a large class of engineering problems, like GPS simulation data post-processing, where computational time is a critical resource and is one of the most important considerations. An approach is developed that allows to speed-up post-processing by an order of magnitude. It is based on improving the post-processing bottleneck interpolation algorithm using apriori information that is specific to the GPS simulation application. The presented post-processing scheme was used in support of a few successful space flight missions carrying GPS receivers. A future approach to solving the post-processing performance problem using Field Programmable Gate Array (FPGA) technology is described.

  9. GLORI (GLObal navigation satellite system Reflectometry Instrument): A New Airborne GNSS-R receiver for land surface applications (United States)

    Motte, Erwan; Zribi, Mehrez; Fanise, Pascal


    GLORI (GLObal navigation satellite system Reflectometry Instrument) is a new receiver dedicated to the airborne measurement of surface parameters such as soil moisture and biomass above ground and sea state (wave height and direction) above oceans. The instrument is based on the PARIS concept [Martin-Neira, 1993] using both the direct and surface-reflected L-band signals from the GPS constellation as a multistatic radar source. The receiver is based on one up-looking and one down-looking dual polarization hemispherical active antennas feeding a low-cost 4-channel SDR direct down-conversion receiver tuned to the GPS L1 frequency. The raw measurements are sampled at 16.368MHz and stored as 2-bit, IQ binary files. In post-processing, GPS acquisition and tracking are performed on the direct up-looking signal while the down-looking signal is processed blindly using tracking parameters from the direct signal. The obtained direct and reflected code-correlation waveforms are the basic observables for geophysical parameters inversion. The instrument was designed to be installed aboard the ATR42 experimental aircraft from the French SAFIRE fleet as a permanent payload. The long term goal of the project is to provide real-time continuous surface information for every flight performed. The aircraft records attitude information through its Inertial Measurement Unit and a commercial GPS receiver records additional information such as estimated doppler and code phase, receiver location, satellites azimuth and elevation. A series of test flights were performed over both the Toulouse and Gulf of Lion (Mediterranean Sea) regions during the period 17-21 Nov 2014 together with the KuROS radar [Hauser et al., 2014]. Using processing methods from the literature [Egido et al., 2014], preliminary results demonstrate the instrument sensitivity to both ground and ocean surface parameters estimation. A dedicated scientific flight campaign is planned at the end of second quarter 2015 with

  10. EGNSS High Accuracy System Improving Photovoltaic Plant Maintenance using RPAS integrated with Low-cost RTK Receiver

    DEFF Research Database (Denmark)

    Nisi, Marco; Menichetti, Fabio; Bilal, Muhammad

    Global Navigation Satellite System (GNSS) Real Time Kinematic (RTK) is the key enabling technology for a number of applications demanding very high positioning accuracy as their operational requirement. This include, but not limited to, mapping, surveying, robot guidance, and precision agriculture...... to name a few. Typically, GNSS RTK employs high-end dual-frequency receivers and antennas to deliver precise positioning that, in some way, restricts the use of GNSS RTK to a subset of user market due to very high cost. The emerging mass-market user applications, however, require centimeter positioning...... accuracy considering a cost-effective solution. This calls for low-cost GNSS RTK technology to create new possibilities for mass-market user applications to make use of GNSS high accuracy positioning in a variety of ways. One of the applications that make use of low-cost RTK is EGNSS high accuracy system...

  11. An Analytical Approach for Performance Enhancement of FSO Communication System Using Array of Receivers in Adverse Weather Conditions (United States)

    Nagpal, Shaina; Gupta, Amit


    Free Space Optics (FSO) link exploits the tremendous network capacity and is capable of offering wireless communications similar to communications through optical fibres. However, FSO link is extremely weather dependent and the major effect on FSO links is due to adverse weather conditions like fog and snow. In this paper, an FSO link is designed using an array of receivers. The disparity of the link for very high attenuation conditions due to fog and snow is analysed using aperture averaging technique. Further effect of aperture averaging technique is investigated by comparing the systems using aperture averaging technique with systems not using aperture averaging technique. The performance of proposed model of FSO link has been evaluated in terms of Q factor, bit error rate (BER) and eye diagram.

  12. Dynamic modeling of a solar receiver/thermal energy storage system based on a compartmented dense gas fluidized bed (United States)

    Solimene, Roberto; Chirone, Roberto; Chirone, Riccardo; Salatino, Piero


    Fluidized beds may be considered a promising option to collection and storage of thermal energy of solar radiation in Concentrated Solar Power (CSP) systems thanks to their excellent thermal properties in terms of bed-to-wall heat transfer coefficient and thermal diffusivity and to the possibility to operate at much higher temperature. A novel concept of solar receiver for combined heat and power (CHP) generation consisting of a compartmented dense gas fluidized bed has been proposed to effectively accomplish three complementary tasks: collection of incident solar radiation, heat transfer to the working fluid of the thermodynamic cycle and thermal energy storage. A dynamical model of the system laid the basis for optimizing collection of incident radiative power, heat transfer to the steam cycle, storage of energy as sensible heat of bed solids providing the ground for the basic design of a 700kWth demonstration CSP plant.

  13. Multimedia Astronomy Communication: Effectively Communicate Astronomy to the Desired Audience (United States)

    Star Cartier, Kimberly Michelle; Wright, Jason


    A fundamental aspect of our jobs as scientists is communicating our work to others. In this, the field of astronomy holds the double-edged sword of ubiquitous fascination: the topic has been of interest to nearly the entire global population at some point in their lives, yet the learning curve is steep within any subfield and rife with difficult-to-synthesize details. Compounding this issue is the ever-expanding array of methods to reach people in today's Communications Era. Each communication medium has its own strengths and weaknesses, is appropriate in different situations, and requires its own specific skillset in order to maximize its functionality. Despite this, little attention is given to training astronomers in effective communication techniques, often relying on newcomers to simply pick up the ability by mimicking others and assuming that a firm grasp on the subject matter will make up for deficiencies in communication theory. This can restrict astronomers to a narrow set of communication methods, harming both the communicators and the audience who may struggle to access the information through those media.Whether writing a research paper to academic peers or giving an astronomy talk to a pubic audience, successfully communicating a scientific message requires more than just an expert grasp on the topic. A communicator must understand the makeup and prior knowledge of the desired audience, be able to break down the salient points of the topic into pieces that audience can digest, select and maximize upon a medium to deliver the message, and frame the message in a way that hooks the audience and compels further interest. In this work we synthesize the requirements of effective astronomy communication into a few key questions that every communicator needs to answer. We then discuss some of the most common media currently used to communicate astronomy, give both effective and poor examples of utilizing these media to communicate astronomy, and provide key

  14. Tangible Things of American Astronomy (United States)

    Schechner, Sara Jane


    As a science that studies celestial objects situated at vast distances from us, astronomy deals with few things that can be touched directly. And yet, astronomy has many tangible things—scientific instruments, observatories, and log books, for example—which link the past to the present. There is little question about maintaining things still valuable for scientific research purposes, but why should we care about documenting and preserving the old and obsolete? One answer is that material things, when closely examined, enhance our knowledge of astronomy’s history in ways that written texts alone cannot do. A second answer is that learning about the past helps us live critically in the present. In brief case studies, this talk will find meaning in objects that are extraordinary or commonplace. These will include a sundial, an almanac, telescopes, clocks, a rotating desk, photographic plates, and fly spankers.

  15. Academic Training: Gravitational Waves Astronomy

    CERN Multimedia


    2006-2007 ACADEMIC TRAINING PROGRAMME LECTURE SERIES 16, 17, 18 October from 11:00 to 12:00 - Main Auditorium, bldg. 500 Gravitational Waves Astronomy M. LANDRY, LIGO Hanford Observatory, Richland, USA Gravitational wave astronomy is expected to become an observational field within the next decade. First direct detection of gravitational waves is possible with existing terrestrial-based detectors, and highly probable with proposed upgrades. In this three-part lecture series, we give an overview of the field, including material on gravitional wave sources, detection methods, some details of interferometric detectors, data analysis methods, and current results from observational data-taking runs of the LIGO and GEO projects. ENSEIGNEMENT ACADEMIQUE ACADEMIC TRAINING Françoise Benz 73127 If you wish to participate in one of the following courses, please tell to your supervisor and apply electronically from the course description pages that can be found on the Web at: http://www...

  16. Dictionary of astronomy, space, and atmospheric phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Tver, D.F.; Motz, L.; Hartmann, W.K.


    This concise and up-to-date compendium features descriptions and definitions of terms, techniques and equipment relating to celestial phenomena. It explains the latest concepts in space exploration, planetary research, stellar astronomy, and meteorological science. The authors explore the general configurations of star groups, galaxy types, stars, and other small bodies in the solar system, including such important facts as magnitude of each and distance from Earth. They describe the brightest stars one by one. Vital data provided by the Viking, Mariner, and Pioneer space probes, the Voyager flights past Jupiter and its moons, and the Apollo landings are clearly presented and explained. New concepts in stellar astronomy such as quasars, neutron stars (pulsars), and black holes are precisely defined. Also included are discussions of meteor showers and the important rock types found on each planet; definitions of meteorological terms, ad astronomical equipment including telescopes, eyepieces and their accessories, the Golay cell, canopus sensor, filar micrometer, and more. Charts aid in identifying and locating stars and planets, and helpful reference tables list the location of the major celestial bodies - asteroids, constellations, the nearest stars, the brightest stars, interesting double and variable stars and cluters. Also included is the Meisser catalog of the coordinates and magnitudes for more than 100 celestial objects.

  17. Sign Language in Astronomy and Space Sciences (United States)

    Cova, J.; Movilio, V.; Gómez, Y.; Gutiérrez, F.; García, R.; Moreno, H.; González, F.; Díaz, J.; Villarroel, C.; Abreu, E.; Aparicio, D.; Cárdenas, J.; Casneiro, L.; Castillo, N.; Contreras, D.; La Verde, N.; Maita, M.; Martínez, A.; Villahermosa, J.; Quintero, A.


    Teaching science to school children with hearing deficiency and impairment can be a rewarding and valuable experience for both teacher and student, and necessary to society as a whole in order to reduce the discriminative policies in the formal educational system. The one most important obstacle to the teaching of science to students with hearing deficiency and impairments is the lack of vocabulary in sign language to express the precise concepts encountered in scientific endeavor. In a collaborative project between Centro de Investigaciones de Astronomía ``Francisco J. Duarte'' (CIDA), Universidad Pedagógica Experimental Libertador-Instituto Pedagógico de Maturín (UPEL-IPM) and Unidad Educativa Especial Bolivariana de Maturín (UEEBM) initiated in 2006, we have attempted to fill this gap by developing signs for astronomy and space sciences terminology. During two three-day workshops carried out at CIDA in Mérida in July 2006 and UPEL-IPM in Maturín in March 2007 a total of 112 concepts of astronomy and space sciences were coined in sign language using an interactive method which we describe in the text. The immediate goal of the project is to incorporate these terms into Venezuelan Sign Language (LSV).

  18. Astronomy in Brazilian music and poetry (United States)

    de Freitas Mourão, Ronaldo Rogério


    The rôle of astronomy in the Brazilian cultural diversity -though little known world- has been enormous. Thus, the different forms of popular music and erudite, find musical compositions and lyrics inspired by the stars, the eclipses in rare phenomena such as the transit of Venus in front of the sun in 1882, the appearance of Halley's Comet in 1910, in the Big Bang theory. Even in the carnival parades of the blocks at the beginning of the century astronomy was present. More recently, the parade of 1997, the samba school Unidos do Viradouro, under the direction of Joãozinho Trinta, offered a new picture of the first moments of the creation of the universe to join in the white and dark in the components of their school, the idea of matter and anti-matter that reigned in the early moments of the creation of the universe in an explosion of joy. Examples in classical music include Dawn of Carlos Gomes and Carta Celeste by Almeida Prado. Unlike The Planets by Gustav Holst -who between 1914 and 1916 composed a symphonical tribute to the solar system based on astrology- Almeida Prado composed a symphony that is not limited to the world of planets, penetrating the deep cosmos of galaxies. Using various resources of the technique for the piano on the clusters and static movements, violent conflicts between the records of super acute and serious instrument, harpejos cross, etc . . .

  19. LGBT Workplace Climate in Astronomy (United States)

    Gaudi, B. S.; Danner, R.; Dixon, W. V.; Henderson, C. B.; Kay, L. E.


    The AAS Working Group on LGBTIQ Equality (WGLE) held a town hall meeting at the 220th AAS meeting in Anchorage to explore the workplace climate for LGBTIQ individuals working in Astronomy and related fields. Topics of discussion included anti-discrimination practices, general workplace climate, and pay and benefit policies. Four employment sectors were represented: industry, the federal government, private colleges, and public universities. We will summarize and expand on the town hall discussions and findings of the panel members.

  20. RASDR: Benchtop Demonstration of SDR for Radio Astronomy

    Energy Technology Data Exchange (ETDEWEB)

    Vacaliuc, Bogdan [ORNL; Oxley, Paul [Retired; Fields, David [ORNL; Kurtz, Dr. Stan [Universidad Nacional Autonoma de Mexico (UNAM); Leech, Marcus [Shirleys Bay Radio Astronomy Consortium


    The Society of Amateur Radio Astronomers (SARA) members present the benchtop version of RASDR, a Software Defined Radio (SDR) that is optimized for Radio Astronomy. RASDR has the potential to be a common digital receiver interface useful to many SARA members. This document describes the RASDR 0.0 , which provides digitized radio data to a backend computer through a USB 2.0 interface. A primary component of RASDR is the Lime Microsystems Femtocell chip which tunes from a 0.4-4 GHz center frequency with several selectable bandwidths from 0.75 MHz to 14 MHz. A second component is a board with a Complex Programmable Logic Device (CPLD) chip that connects to the Femtocell and provides two USB connections to the backend computer. A third component is an analog balanced mixer up conversion section. Together these three components enable RASDR to tune from 0.015 MHz thru 3.8GHz of the radio frequency (RF) spectrum. We will demonstrate and discuss capabilities of the breadboard system and SARA members will be able to operate the unit hands-on throughout the workshop.

  1. Using art as a medium in communicating astronomy (United States)

    Lau, C. C.


    Batik is a delicate art that requires patience and skill. It is a process of "painting" and "drawing" a unique pattern on fabric using dye and wax. Malaysian designers usually use organic motifs such as flowers, animals, plants, shapes and geometric motifs for their Batik designs. But, in 2006, the Malaysian National Space Agency organised a Batik Art Competition "Space - My Inspiration". Participants were required to produce motifs of space science for their Batik making on the fabric (which measured 1m x 1m) and to write a summary about their Batik design. The objective of this competition was to promote space using Batik and encourage designers or the public to combine space science elements in producing Batik art. This competition had a good response and we received 106 entries from people with art backgrounds, university students, and college students to designers. These participants used backgrounds of the night sky, galaxies, nebulae, the Milky Way, the Solar System and astronauts as their Batik's motif. After this competition, a space Batik exhibition and other space Batik art activities were carried out. It showed that Batik art is an excellent educational and communication tool for astronomy. In conclusion, the Malaysian National Space Agency will carry out various types of space art activities in the future to create awareness and interest in space science among artists.

  2. Astronomy Outreach for Large, Unique, and Unusual Audiences (United States)

    Lubowich, Donald


    My successful outreach program venues include: outdoor concerts and festivals; the US National Mall; churches, synagogues, seminaries, or clergy conferences; the Ronald McDonald Houses of Long Island and Chicago; the Winthrop U. Hospital Children’s Medical Center the Fresh Air Fund summer camps (low-income and special needs); a Halloween star party (costumed kids look through telescopes); a Super Bowl Star Party (targeting women); Science Festivals (World, NYC; Princeton U.; the USA Science and Engineering Festival); and the NYC Columbus Day Parade. Information was also provided about local science museums, citizen science projects, astronomy educational sites, and astronomy clubs to encourage lifelong learning. In 2010 I created Astronomy Festival on the National Mall (co-sponsored by the White House Office of Science and Technology Policy) with the participation of astronomy clubs, scientific institutions and with Tyco Brahe, Johannes Kepler, and Caroline Herschel making guest appearances. My programs include solar, optical, and radio telescope observations, hands-on activities, a live image projection system; large outdoor posters and banners; videos; hands-on activities, and edible astronomy demonstrations.My NASA-funded Music and Astronomy Under the Stars (MAUS) program (60 events 2009 - 2013) reached 50,000 music lovers at local parks and the Central Park Jazz, Newport Folk, Ravinia, or Tanglewood Music Festivals with classical, folk, pop/rock, opera, Caribbean, or county-western concerts assisted by astronomy clubs. Yo-Yo-Ma, the Chicago and Boston Symphony Orchestras, Ravi Coltrane, Esperanza Spalding, Phish, Blood Sweat and Tears, Deep Purple, Tony Orlando, and Wilco performed at these events. MAUS reached underserved groups and attracted large crowds. Young kids participated in this family learning experience - often the first time they looked through a telescope. While < 50% of the participants took part in a science activity in the past year, they

  3. Astronomy in the National Parks (United States)

    Nordgren, Tyler E.


    American national parks are fertile grounds for astronomy and planetary science outreach. They are some of the last remaining dark-sky sites the typical visitor (both U.S. and international) can still experience easily. An internal National Park Service (NPS) study shows a dark starry sky is an integral part of what visitors consider their park experience. As a result, the NPS Night Sky Team (a coordinated group of park rangers and astronomers) is measuring and monitoring the sky brightness over the parks in an attempt to promote within the park service protection of the night sky as a natural resource. A number of parks (e.g. Grand Canyon National Park) are currently expanding their night sky related visitor programs in order to take advantage of this resource and visitor interest. The national parks and their visitors are therefore an ideal audience fully "primed” to learn about aspects of astronomy or planetary science that can be, in any way, associated with the night sky. As one of the astronomers on the NPS Night Sky Team, I have been working with park service personnel on ways to target park visitors for astronomical outreach. The purpose of this outreach is twofold: 1) Strengthen popular investment in preserving dark skies, 2) Strengthen popular investment in current astronomical research. A number of avenues already being used to introduce astronomy outreach into the parks (beyond the simple "star party") will be presented.

  4. Innovative Technology for Teaching Introductory Astronomy (United States)

    Guidry, Mike

    The application of state-of-the-art technology (primarily Java and Flash MX Actionscript on the client side and Java PHP PERL XML and SQL databasing on the server side) to the teaching of introductory astronomy will be discussed. A completely online syllabus in introductory astronomy built around more than 350 interactive animations called ""Online Journey through Astronomy"" and a new set of 20 online virtual laboratories in astronomy that we are currently developing will be used as illustration. In addition to demonstration of the technology our experience using these technologies to teach introductory astronomy to thousands of students in settings ranging from traditional classrooms to full distance learning will be summarized. Recent experiments using Java and vector graphics programming of handheld devices (Personal Digital Assistants and cell phones) with wireless wide-area connectivity for applications in astronomy education will also be described.

  5. Evaluation of a College Freshman Diversity Research Program in Astronomy (United States)

    Tremmel, Michael J.; Garner, S. M.; Schmidt, S. J.; Wisniewski, J. P.; Agol, E.


    Graduate students in the astronomy department at the University of Washington began the Pre-Major in Astronomy Program (Pre-MAP) after recognizing that underrepresented students in STEM fields are not well retained after their transition from high school. Pre-MAP is a research and mentoring program that begins with a keystone seminar where they learn astronomical research techniques that they apply to research projects conducted in small groups. Students also receive one-on-one mentoring and peer support for the duration of the academic year and beyond. Successful Pre-MAP students have declared astronomy and physics majors, expanded their research projects beyond the fall quarter, presented posters at the UW Undergraduate Research Symposium, and received research fellowships and summer internships. Here we examine the success of the program in attracting underrepresented minorities and in facilitating better STEM retention and academic performance among incoming UW students. We use the University of Washington Student Database to study both the performance of Pre-MAP students and the overall UW student body over the past 8 years. We show that Pre-MAP students are generally more diverse than the overall UW population and also come in with a variety of different math backgrounds, which we show to be an important factor on STEM performance for the overall UW population. We find that that Pre-MAP students are both more academically successful and more likely to graduate in STEM fields than their UW peers, regardless of initial math placement.

  6. Astronomy Education through the NSF GK-12 Program (United States)

    Jensen, A. G.


    The National Science Foundation's GK-12 program encourages graduate students in science to be active in public education at the middle school and high school levels. As a GK-12 fellow at the University of Colorado-Boulder (CU), I worked with a local 8th-grade science teacher and his students during the 2003-2004 school year. In the Boulder Valley School District, 8th-grade science covers Earth history, meteorology, astronomy, and oceanography. There are many special challenges for this school district and 8th-grade education in Colorado, including a large number of English as a second language (ESL) students and the administration of standardized tests during March, before students have completed much of the relevant material. As a GK-12 Fellow, my responsibilities included work with the Earth history Full Option Science System (FOSS) kit, guest lecturing, aid in hands-on exercises, and the creation of new activities and assignments. Astronomy activities accomplished through this program include sunspot viewing and a field trip to the Colorado Scale Model Solar System on the CU campus. The GK-12 program at CU will continue for at least two more years, possibly placing future GK-12 fellows who are astronomy grad students into classes that are astronomy- or physics-specific.

  7. Development of a high temperature solar receiver for high-efficient thermionic conversion systems; Fukugo netsuden henkan system yo chokoon taiyo junetsuki no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Umeoka, T.; Naito, H.; Yugami, H.; Arashi, H. [Tohoku University, Sendai (Japan). Faculty of Engineering


    For thermionic conversion systems (TIC) using concentrated sunlight as heat source, the newly developed solar receiver was tested. Concentrated sunlight aims at the inner surface of the cavity type solar receiver. The emitter of TIC installed in the rear of the solar receiver is uniformly heated over 1700K by thermal radiation from the rear of the solar receiver, emitting thermion. Electric power is generated by collecting the thermion by collector. Mo is used as emitter material, however, because of poor heat absorption of Mo, high-absorptive TiC is used for heat absorption surface to heat Mo by thermal conduction from high-temperature TiC. Functionally gradient material (FGM) with an intermediate layer of gradient TiC/Mo ratios between TiC and Mo is used as emitter material. The emitter is thus uniformly heated at high temperatures of 1723{plus_minus}12K. As a result, the developed solar receiver is applicable to heat the emitter of TIC. Heat flux measurement at the graphite cavity clarified that cavity temperature of as high as 1780K and heat flow of 50W/cm{sup 2} are obtained at 4.7kW in input. 6 figs.

  8. Cultural Astronomy in the Armenian Highland (United States)

    Farmanyan, S. V.; Suvaryan, Yu. M.; Mickaelian, A. M. (Eds.)


    The book contains 29 articles of the Proceedings of the Young Scientists Conference "Cultural Astronomy in the Armenian Highland" held at the Armenian National Academy of Sciences on 20-23 June 2016. It consists of 4 main sections: "Introductory", "Cultural Astronomy", "Archaeoastronomy", "Scientific Tourism and Journalism, Astronomical Education and Amateur Astronomy". The book may be interesting to astronomers, culturologists, philologists, linguists, historians, archaeologists, art historians, ethnographers and to other specialists, as well as to students.

  9. The IAU Office of Astronomy for Development (United States)

    Govender, Kevin


    On 16 April 2011 the IAU's Office of Astronomy for Development (OAD) was launched jointly by the President of the IAU and the South African Minister of Science and Technology, at the South African Astronomical Observatory in Cape Town. This OAD was set up to realise the IAU's strategic plan which aims to use astronomy as a tool for development. Communicating astronomy with the public is one of the OAD's focus areas.

  10. Women in Early British and Irish Astronomy Stars and Satellites

    CERN Document Server

    Brück, Mary


    Careers in astronomy for women (as in other sciences) were a rarity in Britain and Ireland until well into the twentieth century. The book investigates the place of women in astronomy before that era, recounted in the form of biographies of about 25 women born between 1650 and 1900 who in varying capacities contributed to its progress during the eighteenth, nineteenth and early twentieth centuries. There are some famous names among them whose biographies have been written before now, there are others who have received less than their due recognition while many more occupied inconspicuous and sometimes thankless places as assistants to male family members. All deserve to be remembered as interesting individuals in an earlier opportunity-poor age. Placed in roughly chronological order, their lives constitute a sample thread in the story of female entry into the male world of science. The book is aimed at astronomers, amateur astronomers, historians of science, and promoters of women in science, but being writte...

  11. The Astronomy Thesaurus and UDC -- Present and Future (Group Discussion for Users and Potential Users) (United States)

    Cummins, Marlene

    A brief discussion of the potential and problems of the Astronomy Thesaurus and UDC classification system took place. Once again, no resolution to the questions of updating and revising these items was found.

  12. Improving Astronomy Achievement and Attitude through Astronomy Summer Project: A Design, Implementation and Assessment (United States)

    Türk, Cumhur; Kalkan, Hüseyin; Iskeleli', Nazan Ocak; Kiroglu, Kasim


    The purpose of this study is to examine the effects of an astronomy summer project implemented in different learning activities on elementary school students, pre-service elementary teachers and in-service teachers' astronomy achievement and their attitudes to astronomy field. This study is the result of a five-day, three-stage, science school,…

  13. The Relationship between Preservice Science Teachers' Attitude toward Astronomy and Their Understanding of Basic Astronomy Concepts (United States)

    Bektasli, Behzat


    Turkish preservice science teachers have been taking a two-credit astronomy class during the last semester of their undergraduate program since 2010. The current study aims to investigate the relationship between preservice science teachers' astronomy misconceptions and their attitudes toward astronomy. Preservice science teachers were given an…

  14. Low complexity MIMO receivers

    CERN Document Server

    Bai, Lin; Yu, Quan


    Multiple-input multiple-output (MIMO) systems can increase the spectral efficiency in wireless communications. However, the interference becomes the major drawback that leads to high computational complexity at both transmitter and receiver. In particular, the complexity of MIMO receivers can be prohibitively high. As an efficient mathematical tool to devise low complexity approaches that mitigate the interference in MIMO systems, lattice reduction (LR) has been widely studied and employed over the last decade. The co-authors of this book are world's leading experts on MIMO receivers, and here they share the key findings of their research over years. They detail a range of key techniques for receiver design as multiple transmitted and received signals are available. The authors first introduce the principle of signal detection and the LR in mathematical aspects. They then move on to discuss the use of LR in low complexity MIMO receiver design with respect to different aspects, including uncoded MIMO detection...

  15. Response of Global Navigation Satellite System receivers to known shaking between 0.2 and 20 Hertz (United States)

    Langbein, John; Evans, John R.; Blume, Fredrick; Johanson, Ingrid


    Over the past decade, several technological advances have allowed Global Navigation Satellite Systems (GNSS) receivers to have the capability to record displacements at high frequencies, with sampling rates approaching 100 samples per second (sps). In addition, communication and computer hardware and software have allowed various institutions, including the U.S. Geological Survey (USGS), to retrieve, process, and display position changes recorded by a network of GNSS sites with small, less than 1-s delays between the time that the GNSS receiver records signals from a constellation of satellites and the time that the position is estimated (a method known as “real-time”). These improvements in hardware and software have allowed the USGS to process GNSS (or a subset of the GNSS, the Global Positioning System, GPS) data in real-time at 1 sps with the goal of determining displacements from earthquakes and volcanoes in real-time. However, the current set of GNSS equipment can record at rates of 100 sps, which allows the possibility of using this equipment to record earthquake displacements over the full range of frequencies that typically are recorded by acceleration and velocity transducers. The advantage of using GNSS to record earthquakes is that the displacement, rather than acceleration or velocity, is recorded, and for large earthquakes, the GNSS sensor stays on scale and will not distort the observations due to clipping of the signal at its highest amplitude. The direct observation of displacement is advantageous in estimating the size and spatial extent of the earthquake rupture. Otherwise, when using velocity or acceleration sensors, the displacements are determined by numerical integration of the observations, which can introduce significant uncertainty in the estimated displacements. However, GNSS technology can, at best, resolve displacements of a few millimeters, and for most earthquakes, their displacements are less than 1 mm. Consequently, to be useful

  16. Low-level software for the pentek 6510 digital receiver board applied to the new AD beam measurement system

    CERN Document Server

    Angoletta, Maria Elena


    The new beam measurement system for the CERN Antiproton Decelerator heavily relies on a Pentek 6510 Digital Receiver (DRX) board. The new system goal is to extract beam parameters from pickup signals. Its digital implementation allows for higher precision, easier management of the hardware as well as modification and improvement with no hardware change. In this scheme, this innovative VME DRX board is responsible for parallel data acquisition, independent digital down conversion and processing of up to 4 digitised inputs. The in-house- developed low-level code (LLC), running on the board, takes care of several tasks, such as interfacing with the Real Time Task (RTT), data processing and board managing. The RTT runs on a PowerPC VME board and controls the DRX board as a master. The LLC is a state machine developed in C and Assembler, which services several interrupts and performs the FFT of complex input data. The DRX low-level system developed is highly modular and easily adaptable to other processing scenari...

  17. A New Online Astronomy Resource for Education and Outreach (United States)

    Impey, C. D.; Hardegree-Ullman, K. K.; Patikkal, A.; Srinathan, A.; Austin, C. L.; Ganesan, N. K.; Guvenen, B. C.


    A new web site called "Teach Astronomy" ( has been created to serve astronomy instructors and their students, amateur astronomers, and members of the public interested in astronomy. The

  18. Inspiring the Next Generation: Astronomy Catalyzes K12 STEM Education (United States)

    Borders, Kareen; Thaller, Michelle; Winglee, Robert; Borders, Kyla


    K-12 educators need effective and relevant astronomy professional development. NASA's Mission Science provides innovative and accessible opportunities for K-12 teachers. Science questions involve scale and distance, including Moon/Earth scale, solar system scale, and distance of objects in the universe. Teachers can gain an understanding of basic telescopes, the history of telescopes, ground and satellite based telescopes, and models of JWST Telescope. An in-depth explanation of JWST and Spitzer telescopes gave participants background knowledge for infrared astronomy observations. During teacher training, we taught the electromagnetic spectrum through interactive stations. The stations included an overview via lecture and power point, the use of ultraviolet beads to determine ultraviolet exposure, the study of lenticulars and diagramming of infrared data, looking at visible light through diffraction glasses and diagramming the data, protocols for using astronomy based research in the classroom, and infrared thermometers to compare environmental conditions around the observatory. An overview of LIDAR physics was followed up by a simulated LIDAR mapping of the topography of Mars.We will outline specific steps for K-12 infrared astronomy professional development, provide data demonstrating the impact of the above professional development on educator understanding and classroom use, and detail future plans for additional K-12 professional development.Funding was provided by Washington STEM, NASA, and the Washington Space Grant Consortium.

  19. Building worlds and learning astronomy on Facebook (United States)

    Harold, J. B.; Hines, D. C.


    James Harold (SSI), Dean Hines (STScI/SSI) and a team at the National Center for Interactive Learning at the Space Science Institute are developing an end-to-end stellar and planetary evolution game for the Facebook platform. Supported by NSF and NASA, and based in part on a prototype funded by STScI several years ago ('MyStar'), the game uses the 'sporadic play' model of games such as Farmville, where players might only take actions a few times a day, but continue playing for months. This framework is an excellent fit for teaching about the evolution of stars and planets. Players will select regions of the galaxy to build their stars and planets, and watch as the systems evolve in scaled real time (a million years to the minute). Massive stars will supernova within minutes, while lower mass stars like our sun will live for weeks, possibly evolving life before passing through a red giant stage and ending their lives as white dwarfs. In addition to allowing players to explore a variety of astronomy concepts (stellar lifecycles, habitable zones, the roles of giant worlds in creating habitable solar systems), the game also allows us to address specific misconceptions. For instance, the game's solar system visualization engine is being designed to confront common issues concerning orbital shapes and scales. 'Mini games' will also let players unlock advanced functionality, while allowing us to create activities focused on specific learning goals. This presentation will focus on the current state of the project as well as its overall goals, which include reaching a broad audience with basic astronomy concepts as well as current science results; exploring the potential of social, 'sporadic play' games in education; and determining if platforms such as Facebook allow us to reach significantly different demographics than are generally targeted by educational games.

  20. Infrared astronomy seeing the heat : from William Herschel to the Herschel space observatory

    CERN Document Server

    Clements, David L


    Uncover the Secrets of the Universe Hidden at Wavelengths beyond Our Optical GazeWilliam Herschel's discovery of infrared light in 1800 led to the development of astronomy at wavelengths other than the optical. Infrared Astronomy - Seeing the Heat: from William Herschel to the Herschel Space Observatory explores the work in astronomy that relies on observations in the infrared. Author David L. Clements, a distinguished academic and science fiction writer, delves into how the universe works, from the planets in our own Solar System to the universe as a whole. The book first presents the major t

  1. Risk of high-grade cervical dysplasia and cervical cancer in women with systemic lupus erythematosus receiving immunosuppressive drugs. (United States)

    Feldman, C H; Liu, J; Feldman, S; Solomon, D H; Kim, S C


    Objective Prior studies suggest an increased risk of cervical cancer among women with systemic lupus erythematosus. However, the relationship with immunosuppressive drugs is not well studied in US nationwide cohorts. We compared the risk of high-grade cervical dysplasia and cervical cancer among women with systemic lupus erythematosus who started immunosuppressive drugs versus hydroxychloroquine. Methods We identified systemic lupus erythematosus patients initiating immunosuppressive drugs or hydroxychloroquine using claims data from two US commercial health plans and Medicaid (2000-2012). We used a validated claims-based algorithm to identify high-grade cervical dysplasia or cervical cancer. To account for potential confounders, including demographic factors, comorbidities, medication use, HPV vaccination status, and health care utilization, immunosuppressive drugs and hydroxychloroquine initiators were 1:1 matched on the propensity score. We used inverse variance-weighted, fixed effect models to pool hazard ratios from the propensity score-matched Medicaid and commercial cohorts. Results We included 2451 matched pairs of immunosuppressive drugs and hydroxychloroquine new users in the commercial cohort and 7690 matched pairs in Medicaid. In the commercial cohort, there were 14 cases of cervical dysplasia or cervical cancer among immunosuppressive drugs users and five cases among hydroxychloroquine users (hazard ratio 2.47, 95% CI 0.89-6.85, hydroxychloroquine = ref). In Medicaid, there were 46 cases among immunosuppressive drugs users and 29 cases in hydroxychloroquine users (hazard ratio 1.24, 95% CI 0.78-1.98, hydroxychloroquine = ref). The pooled hazard ratio of immunosuppressive drugs was 1.40 (95% CI 0.92-2.12). Conclusion Among women with systemic lupus erythematosus, immunosuppressive drugs may be associated with a greater, albeit not statistically significant, risk of high-grade cervical dysplasia and cervical cancer compared to patients receiving

  2. Copernican Astronomy and Oceanic Exploration (United States)

    McKittrick, Paul


    This paper examines the relationships between the century long development of the “New Astronomy” (Copernicus’ axially rotating and solar orbiting earth, governed by Kepler’s laws of planetary motion) of the sixteenth and early seventeenth centuries and the emerging astronomical navigation technologies of the fifteenth and sixteenth century Iberian oceanic explorers and their sixteenth and seventeenth century Protestant competitors. Since the first breakthroughs in Portuguese astronomical navigation in ascertaining latitude at sea were based upon the theories and observations of classically trained Ptolemaic astronomers and cosmographers, it can be argued that the new heliocentric astronomy was not necessary for future developments in early modern navigation. By examining the history of the concurrent revolutions in early modern navigation and astronomy and focusing upon commonalities, we can identify the period during which the old astronomy provided navigators with insufficient results - perhaps hastening the acceptance of the new epistemology championed by Galileo and rejected by Bellarmine. Even though this happened during the period of northern protestant ascendancy in exploration, its roots can be seen during pre-Copernican acceptance in both Lutheran and Catholic Europe. Copernican mathematics was used to calculate Reinhold’s Prutenic Tables despite the author’s ontological rejection of the heliocentric hypothesis. These tables became essential for ascertaining latitude at sea. Kepler’s Rudophine Tables gained even more widespread currency across Europe. His theories were influenced by Gilbert’s work on magnetism - a work partially driven by the requirements of English polar exploration. Sailors themselves never needed to accept a heliocentric cosmography, but the data they brought back to the metropolis undermined Ptolemy, as better data kept them alive at sea. This exchange between theoretician and user in the early modern period drove both

  3. Impacts from urban water systems on receiving waters - How to account for severe wet-weather events in LCA? (United States)

    Risch, Eva; Gasperi, Johnny; Gromaire, Marie-Christine; Chebbo, Ghassan; Azimi, Sam; Rocher, Vincent; Roux, Philippe; Rosenbaum, Ralph K; Sinfort, Carole


    Sewage systems are a vital part of the urban infrastructure in most cities. They provide drainage, which protects public health, prevents the flooding of property and protects the water environment around urban areas. On some occasions sewers will overflow into the water environment during heavy rain potentially causing unacceptable impacts from releases of untreated sewage into the environment. In typical Life Cycle Assessment (LCA) studies of urban wastewater systems (UWS), average dry-weather conditions are modelled while wet-weather flows from UWS, presenting a high temporal variability, are not currently accounted for. In this context, the loads from several storm events could be important contributors to the impact categories freshwater eutrophication and ecotoxicity. In this study we investigated the contributions of these wet-weather-induced discharges relative to average dry-weather conditions in the life cycle inventory for UWS. In collaboration with the Paris public sanitation service (SIAAP) and Observatory of Urban Pollutants (OPUR) program researchers, this work aimed at identifying and comparing contributing flows from the UWS in the Paris area by a selection of routine wastewater parameters and priority pollutants. This collected data is organized according to archetypal weather days during a reference year. Then, for each archetypal weather day and its associated flows to the receiving river waters (Seine), the parameters of pollutant loads (statistical distribution of concentrations and volumes) were determined. The resulting inventory flows (i.e. the potential loads from the UWS) were used as LCA input data to assess the associated impacts. This allowed investigating the relative importance of episodic wet-weather versus "continuous" dry-weather loads with a probabilistic approach to account for pollutant variability within the urban flows. The analysis at the scale of one year showed that storm events are significant contributors to the impacts

  4. Astronomica: Intergating Astronomy Content and Course Management (United States)

    Impey, C. D.


    At the University of Arizona, the web site serves 1200 students per semester with a wide array of astronomy content that is integrated into course management capabilities. In addition to articles, an image data bank, news stories, and a linked 1200-term glossary, there is a recommendation system and a natural language question and answer tool. The site is built on an XML architecture, which allows the delivery of content to handheld devices. Another part of the web site serves voiceXML to web-enabled cell phones. The goal is to increase the level of student engagement and serve different learning styles. The site and content are available for use by outside instructors.

  5. Dealing with Creationism in Astronomy (United States)

    Bridgman, W. T.


    In recent years, the battle to force some form of pseudo-science into American science classrooms has intensified. In court cases and Boards of Education, the sides have formed between religious groups claiming to desire a `balanced' treatment and scientific groups insisting on a total ban on the topics. But there is a third option which has not been explored. Many claims of `Creation Science' and other pseudosciences can be explored and refuted at the level of introductory physics and astronomy classes. I will present a few claims of Young-Earth Creationists (YECs) pertaining to cosmology and illustrate some methods for refuting them.

  6. Astronomy of the vedic altars (United States)

    Kak, Subhash C.

    In this paper, two ancient Indian texts, the Śatapatha Brāhmana and the Rigveda, are examined for their astronomical content. It is argued that the 95 year ritual of agnicayana had an astronomical basis, which implies a knowledge of the length of the tropical year being equal to 365.24675 days. An astronomical code has been discovered in the structure of the Rigveda, which has been partially deciphered. This code expressed the knowledge that the sun and the moon are about 108 times their respective diameters away from the earth. This analysis leads to a major revision of our understanding of the history of ancient astronomy.

  7. Astronomy Map of the World (United States)

    Veras, D.


    I have created an online clickable and zoom-enabled world map - now viewed over 5,400 times - that contains weblinks to institutions where astronomy is either researched professionally and / or and taught in classrooms at the university level. Not included are stand-alone museums, planetariums, amateur astronomical societies, virtual institutes, nor observatories which do not fulfill this criteria. One can click on a marker to access the relevant institute. The map currently contains 697 institutes, and has multiple potential uses for undergraduate students, graduate students, postdocs, faculty and journal editors.

  8. Astronomy Education in Morocco - New Project for Implementing Astronomy in High Schools (United States)

    Darhmaoui, H.; Loudiyi, K.


    Astronomy education in Morocco, like in many developing countries, is not well developed and lacks the very basics in terms of resources, facilities and research. In 2004, the International Astronomical Union (IAU) signed an agreement of collaboration with Al Akhawayn University in Ifrane to support the continued, long-term development of astronomy and astrophysics in Morocco. This is within the IAU program "Teaching for Astronomy Development" (TAD). The initial focus of the program concentrated exclusively on the University's Bachelor of Science degree program. Within this program, and during two years, we were successful in providing adequate astronomy training to our physics faculty and few of our engineering students. We also offered our students and community general astronomy background through courses, invited talks and extra curricular activities. The project is now evolving towards a wider scope and seeks promoting astronomy education at the high school level. It is based on modules from the Hands on Universe (HOU) interactive astronomy program. Moroccan students will engage in doing observational astronomy from their PCs. They will have access to a world wide network of telescopes and will interact with their peers abroad. Through implementing astronomy education at this lower age, we foresee an increasing interest among our youth not only in astronomy but also in physics, mathematics, and technology. The limited astronomy resources, the lack of teachers experience in the field and the language barrier are amongst the difficulties that we'll be facing in achieving the objectives of this new program.

  9. Student Comprehension of Mathematics through Astronomy (United States)

    Search, Robert


    The purpose of this study is to examine how knowledge of astronomy can enhance college-level learning situations involving mathematics. The fundamental symbiosis between mathematics and astronomy was established early in the 17th century when Johannes Kepler deduced the 3 basic laws of planetary motion. This mutually harmonious relationship…

  10. Preservice Science Teachers' Beliefs about Astronomy Concepts (United States)

    Ozkan, Gulbin; Akcay, Hakan


    The purpose of this study was to investigate preservice science teachers' conceptual understanding of astronomy concepts. Qualitative research methods were used. The sample consists of 118 preservice science teachers (40 freshmen, 31 sophomores, and 47 juniors). The data were collected with Astronomy Conceptual Questionnaire (ACQ) that includes 13…

  11. Resources for Teaching Astronomy in UK Schools (United States)

    Roche, Paul; Newsam, Andy; Roberts, Sarah; Mason, Tom; Baruch, John


    This article looks at a selection of resources currently available for use in the teaching of astronomy in UK schools. It is by no means an exhaustive list but it highlights a variety of free resources that can be used in the classroom to help engage students of all ages with astronomy and space science. It also lists several facilities with a…

  12. Encouraging Student Participation in Large Astronomy Courses (United States)

    Willoughby, Shannon D.


    Introductory astronomy is one of the most widely taught classes in the country and the majority of the students who take these classes are non-science majors. Because this demographic of students makes up the majority of astronomy enrollments, it is especially important as instructors that we do our best to make sure these students don't finish…

  13. Some Daytime Activities in Solar Astronomy (United States)

    Burin, Michael J.


    This century's transits of Venus (2004, 2012) captured significant public attention, reminding us that the wonders of astronomy need not be confined to the night. And while nighttime telescope viewing gatherings (a.k.a. "star parties") are perennially popular, astronomy classes are typically held in the daytime. The logistics of…

  14. Organizations and Strategies in Astronomy, volume 4 (United States)

    Heck, A.


    This book is the fourth volume under the title Organizations and Strategies in Astronomy (OSA). These OSA Books are intended to cover a large range of fields and themes. In practice, one could say that all aspects of astronomy-related life and environment are considered in the spirit of sharing specific expertise and lessons learned. This book offers a unique collection of chapters dealing with socio-dynamical aspects of the astronomy (and related space sciences) community: characteristics of organizations, society activities, strategies for development, operational techniques, observing practicalities, environmental constraints, educational policies, public outreach, journal and magazine profiles, publication studies, electronic-media problematics, research communication, evaluation and selection procedures, research indicators, national policies and specificities, expertise sharing, contemporary history, and so on. The experts contributing to this book have done their best to write in a way understandable to readers not necessarily hyperspecialized in astronomy while providing specific detailed information and sometimes enlightening 'lessons learned' sections. The book concludes with an updated bibliography of publications related to socio-astronomy and to the interactions of the astronomy community with the society at large. This book will be most usefully read by researchers, teachers, editors, publishers, librarians, sociologists of science, research planners and strategists, project managers, public-relations officers, plus those in charge of astronomy-related organizations, as well as by students aiming at a career in astronomy or related space science. Link:

  15. Astronomy all the time for everybody (United States)

    Grigore, Valentin


    General contextCommunicating astronomy with the public must be done all year and with all community members using all the available methods to promote the all aspects of astronomy: education, science, research, new technologies, dark-sky protection, astrophotography, mythology, astropoetry, astro arts and music.An annual calendarTwo aspect must be taken in consideration when create a calendar of activity:- astronomical events (eclipses, meteor showers, comets, etc.)- international and local astronomical events: Global Astronomy Months, Astronomy Day, Globe at Night, ISAN, public activitiesCommunicating astronomy with the whole communityA description of the experience of the author organizing over 500 events in 30 years of activity including all the community members: general public, students, teachers, artists, authorities, people with disabilities, minor and adult prisoners, etc.An experience of seven years as TV producer of the astronomy TV show “Ùs and the Sky” is presented.Promotion of the activityThe relation with the mass-media is an important aspect communicating astronomy with the public.Mass-media between rating and correct information of the public.The role of the cooperation with the community in astronomy projectsA successful model: EURONEAR project

  16. The cost of publishing in Danish astronomy

    DEFF Research Database (Denmark)

    Dorch, Bertil F.

    I investigate the cost of publishing in Danish astronomy on a fine scale, including all direct publication costs: The figures show how the annual number of publications with authors from Denmark in astronomy journals increased by a factor approximately four during 15 years (Elsevier’s Scopus...

  17. Indian Mathematics and Astronomy: Some Land- marks

    Indian Academy of Sciences (India)

    Indian Mathematics and. Astronomy: Some Land- marks. Michio Yano*. Indian Mathematics and Astronomy: Some Landmarks··. By S Balachandra Roo. Jnana Deep Publications, Bangalore,. 1994, Pages, VIII + 234, Price Rs. 751-. On Indio). This book is 'mainly addressed to the student community and general read-.

  18. Training in Astronomy for Physics Students

    Indian Academy of Sciences (India)


    Jan 27, 2016 ... In this paper, we describe what we have done with regard to astronomy training for physics students. More and more students are interested in astronomy, they spend their summer holidays and spare time in observations and studying the observation data. Some students are familiar with using the ...

  19. An Inaugural Girl Scout Destinations Astronomy Camp (United States)

    Lebofsky, Larry A.; McCarthy, Donald W.; Wright, Joe; Wright, Rita; Mace, Mikayla; Floyd, Charmayne


    The University of Arizona (UA) conducted its first teenage Girl Scout Destinations Astronomy Camp. This program was preceded by 24 Leadership Workshops for Adult Girl Scout Leaders, initially supported by EPO funding from NIRCam for JWST. For five days in late June, 24 girls (ages 13-17 years) attended from 16 states. The Camp was led by UA astronomers and long-term educators. Representing Girl Scouts of the USA (GSUSA) were a husband/wife amateur astronomer team who are SOFIA Airborne Astronomy and NASA Solar System Ambassadors. Other leaders included a Stanford undergraduate engineering student who is a lifelong Girl Scout and Gold Award recipient and a recent UA Master’s degree science journalist. The Camp is a residential, hands-on “immersion” adventure in scientific exploration using telescopes in southern Arizona’s Catalina Mountains near Tucson. Under uniquely dark skies girls become real astronomers, operating telescopes (small and large) and associated technologies, interacting with scientists, obtaining images and quantitative data, investigating their own questions, and most importantly having fun actually doing science and building observing equipment. Girls achieve a basic understanding of celestial objects, how and why they move, and their historical significance, leading to an authentic understanding of science, research, and engineering. Girls can lead these activities back home in their own troops and councils, encouraging others to consider STEM field careers. These programs are supported by a 5-year NASA Collaborative Agreement, Reaching for the Stars: NASA Science for Girl Scouts (, through the SETI Institute in collaboration with the UA, GSUSA, Girl Scouts of Northern California, the Astronomical Society of the Pacific, and Aries Scientific, Inc. The Girl Scout Destinations Astronomy Camp aligns with the GSUSA Journey: It’s Your Planet-Love It! and introduces the girls to some of the activities being

  20. JPL Big Data Technologies for Radio Astronomy (United States)

    Jones, Dayton L.; D'Addario, L. R.; De Jong, E. M.; Mattmann, C. A.; Rebbapragada, U. D.; Thompson, D. R.; Wagstaff, K.


    During the past three years the Jet Propulsion Laboratory has been working on several technologies to deal with big data challenges facing next-generation radio arrays, among other applications. This program has focused on the following four areas: 1) We are investigating high-level ASIC architectures that reduce power consumption for cross-correlation of data from large interferometer arrays by one to two orders of magnitude. The cost of operations for the Square Kilometre Array (SKA), which may be dominated by the cost of power for data processing, is a serious concern. A large improvement in correlator power efficiency could have a major positive impact. 2) Data-adaptive algorithms (machine learning) for real-time detection and classification of fast transient signals in high volume data streams are being developed and demonstrated. Studies of the dynamic universe, particularly searches for fast (data be analyzed rapidly and with robust RFI rejection. JPL, in collaboration with the International Center for Radio Astronomy Research in Australia, has developed a fast transient search system for eventual deployment on ASKAP. In addition, a real-time transient detection experiment is now running continuously and commensally on NRAO's Very Long Baseline Array. 3) Scalable frameworks for data archiving, mining, and distribution are being applied to radio astronomy. A set of powerful open-source Object Oriented Data Technology (OODT) tools is now available through Apache. OODT was developed at JPL for Earth science data archives, but it is proving to be useful for radio astronomy, planetary science, health care, Earth climate, and other large-scale archives. 4) We are creating automated, event-driven data visualization tools that can be used to extract information from a wide range of complex data sets. Visualization of complex data can be improved through algorithms that detect events or features of interest and autonomously generate images or video to display those