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Sample records for sun glassfish application

  1. Java EE 7 with GlassFish 4 Application Server

    CERN Document Server

    Heffelfinger, David R

    2014-01-01

    This book is a practical guide and follows a very user-friendly approach. The book aims to get the reader up to speed in Java EE 7 development. All major Java EE 7 APIs and the details of the GlassFish 4 server are covered followed by examples of their use.If you are a Java developers who wants to become proficient with Java EE 7 this book is ideal for you. Readers are expected to have some experience with Java and to have developed and deployed applications in the past, but don't need any previous knowledge of Java EE or J2EE. It teaches the reader how to use GlassFish 4 to develop and deploy

  2. Beginning Java EE 6 Platform with GlassFish 3

    CERN Document Server

    Goncalves, Antonio

    2010-01-01

    Java Enterprise Edition (Java EE) continues to be one of the leading Java technologies and platforms from Oracle (previously Sun). Beginning Java EE 6 Platform with GlassFish 3, Second Edition is this first tutorial book on the final (RTM) version of the Java EE 6 Platform. Step by step and easy to follow, this book describes many of the Java EE 6 specifications and reference implementations, and shows them in action using practical examples. This book uses the new version of GlassFish 3 to deploy and administer the code examples. Written by an expert member of the Java EE 6 specification requ

  3. Parambassis waikhomi, a new species of glassfish (Teleostei: Ambassidae from Loktak Lake, northeastern India

    Directory of Open Access Journals (Sweden)

    K. Geetakumari

    2012-11-01

    Full Text Available Parambassis waikhomi, a new species of glassfish from Loktak Lake, Chindwin basin in Manipur, northeastern India is distinguished from its congeners by the presence of 58-60 lateral line scales; two predorsal bones; a vertically elongated humeral spot; 24 vertebrae; maxilla reaching to ⅓ of the orbit; 8.2- 10.9 interorbital width; four preorbital ridge, 11 preorbital edge, six supraorbital ridge, 18 serrae at lower edge of preoperculum, 24 serrae at hind margin of preoperculum. The species differs from its nearest congener P. ranga by the presence of 9-10 (vs. 12-13 pectoral fin rays and 19-20 (vs. 22-28 gill rakers.

  4. 77 FR 34122 - Application of Sun Air Express, LLC, d/b/a Sun Air International for Commuter Authority

    Science.gov (United States)

    2012-06-08

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF TRANSPORTATION Office of the Secretary Application of Sun Air Express, LLC, d/b/a Sun Air International for Commuter... to show cause why it should not issue an order finding Sun Air Express, LLC d/b/a Sun...

  5. Sun

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ Sun Microsystems, Inc. is committed to open standards,a standardization system, and sharing within the information tech nology field, focusing not only on technical innovation, but also on new ideas, practices and future development.

  6. Application of new control strategy for sun tracking

    Energy Technology Data Exchange (ETDEWEB)

    Rubio, F.R.; Ortega, M.G.; Gordillo, F.; Lopez-Martinez, M. [Depto. Ingenieria de Sistemas y Automatica, Escuela Superior de Ingenieros, Universidad de Sevilla, 41092 Sevilla (Spain)

    2007-07-15

    The application of high concentration solar cells technology allows a significant increase in the amount of energy collected by solar arrays per unit area. However, to make it possible, more severe specifications on the sun pointing error are required. In fact, the performance of solar cells with concentrators decreases drastically if this error is greater than a small value. These specifications are not fulfilled by simple tracking systems due to different sources of errors (e.g., small misalignments of the structure with respect to geographical north) that appear in practice in low cost, domestic applications. This paper presents a control application of a sun tracker that is able to follow the sun with high accuracy without the necessity of either a precise procedure of installation or recalibration. A hybrid tracking system that consists of a combination of open loop tracking strategies based on solar movement models and closed loop strategies using a dynamic feedback controller is presented. Energy saving factors are taken into account, which implies that, among other factors, the sun is not constantly tracked with the same accuracy, to prevent energy overconsumption by the motors. Simulation and experimental results with a low cost two axes solar tracker are exposed, including a comparison between a classical open loop tracking strategy and the proposed hybrid one. (author)

  7. Research and application of devices for synchronously tracking the sun

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Ming; Sun, Youhong; Wang, Qinghua; Wu, Xiaohan [Jilin Univ. Changchun (China). College of Construction Engineering

    2008-07-01

    This paper introduces a concept of apparent motion orbit of the sun, and put forward the theory of synchronous (linear) tracking the sun. Using solarium mechanism to trail the running path of solar hour angel, and using modified sine function framework to trace solar apparent declination path, and then connect these two mechanisms with linear transmission chain. More than 45%{proportional_to}122% electricity can be output by the synchronous tracking photovoltaic (PV) devices compare with those fixed PV ones with the same area between the spring equinox to the summer solstice. The 17m{sup 2} heat collector of synchronous tracking, its static wind-driven power consumption is less than 3.5W (0.2W/m{sup 2}), and the gale consumption is less than 7W(0.34W/m{sup 2}). The apparatus can be utilized widely in solar power, heating, lighting systems and other solar energy utilization. (orig.)

  8. A Comprehensive Introduction to Sun Family Taiji Boxing: Theory and Applications

    Directory of Open Access Journals (Sweden)

    Jake Burroughs

    2012-07-01

    Full Text Available Though well known in China, Sun Family Taiji is one of the least known of Chinese martial arts here in the West. Created by one of China’s top martial artists, Sun Lutang, in what many consider the “Golden Years” of Chinese pugilism (turn of the 20th century, this style offers proper structure, full body power, and dynamic stepping. Training in Sun Taiji presents not only an extremely healthy exercise for all ages, but also an effective system of combat. This is a concise yet inclusive overview of Sun Family Taiji Boxing, including the historical background, real-world applications, and the theory involved in this often overlooked system of Taiji.

  9. Smartphone mobile application delivering personalized, real-time sun protection advice: a randomized clinical trial.

    Science.gov (United States)

    Buller, David B; Berwick, Marianne; Lantz, Kathy; Buller, Mary Klein; Shane, James; Kane, Ilima; Liu, Xia

    2015-05-01

    Mobile smartphones are rapidly emerging as an effective means of communicating with many Americans. Using mobile applications (apps), they can access remote databases, track time and location, and integrate user input to provide tailored health information. A smartphone mobile app providing personalized, real-time sun protection advice was evaluated in a randomized clinical trial. The trial was conducted in 2012 and had a randomized pretest-posttest controlled design with a 10-week follow-up. Data were collected from a nationwide population-based survey panel. A sample of 604 non-Hispanic and Hispanic adults from the Knowledge Panel 18 years or older who owned an Android smartphone were enrolled. The mobile app provided advice on sun protection (ie, protection practices and risk of sunburn) and alerts (to apply or reapply sunscreen and get out of the sun), hourly UV Index, and vitamin D production based on the forecast UV Index, the phone's time and location, and user input. Percentage of days using sun protection and time spent outdoors (days and minutes) in the midday sun and number of sunburns in the past 3 months were collected. Individuals in the treatment group reported more shade use (mean days staying in the shade, 41.0% vs 33.7%; P = .03) but less sunscreen use (mean days, 28.6% vs 34.5%; P = .048) than controls. There was no significant difference in number of sunburns in the past 3 months (mean, 0.60 in the treatment group vs 0.62 for controls; P = .87). Those who used the mobile app reported spending less time in the sun (mean days keeping time in the sun to a minimum, 60.4% for app users vs 49.3% for nonusers; P = .04) and using all protection behaviors combined more (mean days, 39.4% vs 33.8%; P = .04). The mobile app improved some sun protection. Use of the mobile app was lower than expected but associated with increased sun protection. Providing personalized advice when and where people are in the sun may help reduce sun exposure.

  10. Improving the color of bulgur: new industrial applications of tempering and UV/sun-light treatments

    OpenAIRE

    Balci, Fatih; Mustafa BAYRAM

    2014-01-01

    Color (CIE b*; yellowness) is an important parameter for bulgur quality. Color of bulgur is mainly due to natural pigments (carotenoids) that are present at different levels in wheat. In order to increase the customer acceptability, the producers try to obtain yellowish color in bulgur. In this study, two different tempering methods (spray and steam) were used before sun and UV- light polishing applications. Sun and UV-light were applied to tempered bulgur for 12, 24, 36, 48, 60 and 72 h. Moi...

  11. Accurate and Wide-Field-of-View MEMS-Based Sun Sensor for Industrial Applications

    OpenAIRE

    Delgado Seseña, Francisco José; Quero Reboul, José Manuel; García Ortega, Juan de la Cruz; López Tarrida, Cristina; Ortega, Pablo R; Bermejo, Sandra

    2012-01-01

    This paper describes the design, fabrication, sim- ulation, and experimental results of an improved miniaturized two-axis sun sensor for industrial applications, created by adapt- ing a technology used previously in satellite applications. The sensor for each axis is composed of six photodiodes integrated in a crystalline-silicon substrate and a layer of cover glass, which is used to protect the silicon and to hold the windows. The high preci...

  12. Effects of Cosmetic Formulations Containing Hydroxyacids on Sun-Exposed Skin: Current Applications and Future Developments

    Directory of Open Access Journals (Sweden)

    Andrija Kornhauser

    2012-01-01

    Full Text Available This paper describes recent data on the effects of various skin formulations containing hydroxyacids (HAs and related products on sun-exposed skin. The most frequently used classes of these products, such as α- and β-hydroxyacids, polyhydroxy acids, and bionic acids, are reviewed, and their application in cosmetic formulations is described. Special emphasis is devoted to the safety evaluation of these formulations, particularly on the effects of their prolonged use on sun-exposed skin. We also discuss the important contribution of cosmetic vehicles in these types of studies. Data on the effects of HAs on melanogenesis and tanning are also included. Up-to-date methods and techniques used in those explorations, as well as selected future developments in the cosmetic area, are presented.

  13. The vectorial photoelectric effect under solar irradiance and its application to sun sensing

    CERN Document Server

    Hechenblaikner, Gerald

    2014-01-01

    Sun sensors are an integral part of the attitude and orbit control system onboard almost any spacecraft. While the majority of standard analogue sun sensors is based on photo-detectors which produce photo-currents proportional to the cosine of the incidence angle (cosine detectors), we propose an alternative scheme where the vectorial photoelectric effect is exploited to achieve a higher sensitivity of the sensed photo-current to the incidence angle. The vectorial photo-effect is investigated in detail for metal cathode detectors in a space environment. Besides long operational lifetimes without significant degradation, metal cathode detectors are insensitive to earth albedo, which may significantly reduce the errors affecting attitude measurements in low earth orbits. Sensitivity curves are calculated and trade-offs performed with the aim of optimizing the sensitivity whilst also providing currents sufficient for detection. Simple applications and detector configurations are also discussed and compared to ex...

  14. TAE+ 5.1 - TRANSPORTABLE APPLICATIONS ENVIRONMENT PLUS, VERSION 5.1 (SUN3 VERSION)

    Science.gov (United States)

    TAE SUPPORT OFFICE

    1994-01-01

    TAE (Transportable Applications Environment) Plus is an integrated, portable environment for developing and running interactive window, text, and graphical object-based application systems. The program allows both programmers and non-programmers to easily construct their own custom application interface and to move that interface and application to different machine environments. TAE Plus makes both the application and the machine environment transparent, with noticeable improvements in the learning curve. The main components of TAE Plus are as follows: (1) the WorkBench, a What You See Is What You Get (WYSIWYG) tool for the design and layout of a user interface; (2) the Window Programming Tools Package (WPT), a set of callable subroutines that control an application's user interface; and (3) TAE Command Language (TCL), an easy-to-learn command language that provides an easy way to develop an executable application prototype with a run-time interpreted language. The WorkBench tool allows the application developer to interactively construct the layout of an application's display screen by manipulating a set of interaction objects including input items such as buttons, icons, and scrolling text lists. Data-driven graphical objects such as dials, thermometers, and strip charts are also included. TAE Plus updates the strip chart as the data values change. The WorkBench user specifies the windows and interaction objects that will make up the user interface, then specifies the sequence of the user interface dialogue. The description of the designed user interface is then saved into resource files. For those who desire to develop the designed user interface into an operational application, the WorkBench tool also generates source code (C, Ada, and TCL) which fully controls the application's user interface through function calls to the WPTs. The WPTs are the runtime services used by application programs to display and control the user interfaces. Since the WPTs access the

  15. Low-Power Low-Noise CMOS Imager Design: in Micro-Digital Sun Sensor Application

    NARCIS (Netherlands)

    Xie, N.

    2012-01-01

    A digital sun sensor is superior to an analog sun sensor in aspects of resolution, albedo immunity, and integration. The proposed Micro-Digital Sun Sensor (µDSS) is an autonomous digital sun sensor which is implemented by means of a CMOS image sensor, which is named APS+. The µDSS is designed speci

  16. The Other Seven-Eighths--Application of Iceberg Principle in The Sun Also Rises

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    Hemingway is a giant literary figure in American literature and his famous “Iceberg Principle” has great influence on literary creation afterwards. As a main representative of the Lost Generation, he produced great works reflecting the disil usionment that left by the war. The sun also rises is a great one among them and the iceberg principle was successful y applied in the novel. This paper attempts to select a scene of the story to analyze the application of the principle in it, looking for the other seven-eighths.

  17. User-centered development of a smart phone mobile application delivering personalized real-time advice on sun protection.

    Science.gov (United States)

    Buller, David B; Berwick, Marianne; Shane, James; Kane, Ilima; Lantz, Kathleen; Buller, Mary Klein

    2013-09-01

    Smart phones are changing health communication for Americans. User-centered production of a mobile application for sun protection is reported. Focus groups (n = 16 adults) provided input on the mobile application concept. Four rounds of usability testing were conducted with 22 adults to develop the interface. An iterative programming procedure moved from a specification document to the final mobile application, named Solar Cell. Adults desired a variety of sun protection advice, identified few barriers to use and were willing to input personal data. The Solar Cell prototype was improved from round 1 (seven of 12 tasks completed) to round 2 (11 of 12 task completed) of usability testing and was interoperable across handsets and networks. The fully produced version was revised during testing. Adults rated Solar Cell as highly user friendly (mean = 5.06). The user-centered process produced a mobile application that should help many adults manage sun safety.

  18. Improving the color of bulgur: new industrial applications of tempering and UV/sun-light treatments.

    Science.gov (United States)

    Balci, Fatih; Bayram, Mustafa

    2015-09-01

    Color (CIE b*; yellowness) is an important parameter for bulgur quality. Color of bulgur is mainly due to natural pigments (carotenoids) that are present at different levels in wheat. In order to increase the customer acceptability, the producers try to obtain yellowish color in bulgur. In this study, two different tempering methods (spray and steam) were used before sun and UV- light polishing applications. Sun and UV-light were applied to tempered bulgur for 12, 24, 36, 48, 60 and 72 h. Moisture content (%, d.b.), ash content (%, d.b.), protein content (%, d.b.), total carotenoid content in terms of lutein equivalent (TCC) and color values (CIE L*; lightness, CIE b*; yellowness, CIE a*; redness and CIE YI; yellowness index) were determined. It was found that UV-light was more effective (P CIE L* and CIE b* values compared to sunlight. Both tempering methods were significantly (P CIE L*, CIE b* and CIE YI values. Steam tempering has a significant effect (P CIE b* values as well as UV and time of UV exposure. The highest value of TCC i.e. 6.31 μg/g was obtained by using spray tempering and UV-light exposure. As a conclusion, as proposed methods steam tempering and UV-light have an obvious positive effect on the color of bulgur.

  19. Micro-digital sun sensor: an imaging sensor for space applications

    NARCIS (Netherlands)

    Xie, N.; Theuwissen, A.J.P.; Büttgen, B.; Hakkesteegt, H.C.; Jasen, H.; Leijtens, J.A.P.

    2010-01-01

    Micro-Digital Sun Sensor is an attitude sensor which senses relative position of micro-satellites to the sun in space. It is composed of a solar cell power supply, a RF communication block and an imaging chip which is called APS+. The APS+ integrates a CMOS Active Pixel Sensor (APS) of 512×512 pixel

  20. Sun Allergy

    Science.gov (United States)

    ... if you have unusual, bothersome skin reactions after exposure to sunlight. For severe or persistent symptoms, you may need ... m. when the sun is brightest. Avoid sudden exposure to lots of sunlight. Many people have sun allergy symptoms when they ...

  1. GTK+在Sun Solaris系统中的开发与应用%Development and Application in the Sun Solaris System Based on the GTK+

    Institute of Scientific and Technical Information of China (English)

    王雅芬; 胡世安; 刘杉坚; 袁子立

    2012-01-01

    详细阐述了GTK+和Samba的基本概念与关键技术,介绍了一种Sun Solaris系统下的开发图形用户界面GUI(Graphic User Interface)的方法.在Windows系统下利用GTK+开发GUI,并通过Samba软件完成Sun Solaris 和Windows系统下的资源共享及交互,实现了跨系统文件资源共享、可视化操作与文档实时处理,由文件交换/文件传输软件将可执行程序传输至Sun Solaris系统的共享文件夹下,实现Sun Solaris系统下的GUI开发.该方法可操作性强,对不熟悉Sun Solaris系统下编程的用户和开发人员尤为方便,且界面友好、扩展性强、可靠度高、兼容广泛,可广泛应用在Windows与Solaris跨平台移植开发中.%It elaborates on GTK+ and Samba's basic concept and key techonloy,mainly introduces how to develop GUI (Graphic User Interface) on the Sun Solarieis system. In the Windows system developing GUI with GTK+ ,and through Samba software to complete Sun Solaris and Windows system resource sharing and interaction, realize the across system file sharing, visual operation and document processing. By the FXP/FTP software executable program is transmitted to the Sun Solaris shared folders, realization of Sun Solaris system user interface development This method is easy to operate , especially for users and developers not familiar with programming under Sun Solaris system, and has a friendly interface, strong expansibility,high reliability, compatibility with a wide and other advantages. Also it can be widely used in the Windows and Solar in the development of transplantation across platform.

  2. TAE+ 5.1 - TRANSPORTABLE APPLICATIONS ENVIRONMENT PLUS, VERSION 5.1 (SUN3 VERSION WITH MOTIF)

    Science.gov (United States)

    TAE SUPPORT OFFICE

    1994-01-01

    TAE (Transportable Applications Environment) Plus is an integrated, portable environment for developing and running interactive window, text, and graphical object-based application systems. The program allows both programmers and non-programmers to easily construct their own custom application interface and to move that interface and application to different machine environments. TAE Plus makes both the application and the machine environment transparent, with noticeable improvements in the learning curve. The main components of TAE Plus are as follows: (1) the WorkBench, a What You See Is What You Get (WYSIWYG) tool for the design and layout of a user interface; (2) the Window Programming Tools Package (WPT), a set of callable subroutines that control an application's user interface; and (3) TAE Command Language (TCL), an easy-to-learn command language that provides an easy way to develop an executable application prototype with a run-time interpreted language. The WorkBench tool allows the application developer to interactively construct the layout of an application's display screen by manipulating a set of interaction objects including input items such as buttons, icons, and scrolling text lists. Data-driven graphical objects such as dials, thermometers, and strip charts are also included. TAE Plus updates the strip chart as the data values change. The WorkBench user specifies the windows and interaction objects that will make up the user interface, then specifies the sequence of the user interface dialogue. The description of the designed user interface is then saved into resource files. For those who desire to develop the designed user interface into an operational application, the WorkBench tool also generates source code (C, Ada, and TCL) which fully controls the application's user interface through function calls to the WPTs. The WPTs are the runtime services used by application programs to display and control the user interfaces. Since the WPTs access the

  3. Aztec Suns

    Science.gov (United States)

    Petersen, Hugh

    2010-01-01

    The Aztec Sun Stone is a revered Mexican artifact. It is said to be perhaps the most famous symbol of Mexico, besides its flag. It primarily depicts the four great disasters that led to the migration of the Mexica people to modern-day Mexico City. The Aztec Sun Stone also contains pictographs depicting the way the Mexica measured time, and was…

  4. Aztec Suns

    Science.gov (United States)

    Petersen, Hugh

    2010-01-01

    The Aztec Sun Stone is a revered Mexican artifact. It is said to be perhaps the most famous symbol of Mexico, besides its flag. It primarily depicts the four great disasters that led to the migration of the Mexica people to modern-day Mexico City. The Aztec Sun Stone also contains pictographs depicting the way the Mexica measured time, and was…

  5. Photometric magnetic-activity metrics tested with the Sun: application to Kepler M dwarfs

    Directory of Open Access Journals (Sweden)

    Mathur Savita

    2014-05-01

    Full Text Available The Kepler mission has been providing high-quality photometric data leading to many breakthroughs in the exoplanet search and in stellar physics. Stellar magnetic activity results from the interaction between rotation, convection, and magnetic field. Constraining these processes is important if we want to better understand stellar magnetic activity. Using the Sun, we want to test a magnetic activity index based on the analysis of the photometric response and then apply it to a sample of M dwarfs observed by Kepler. We estimate a global stellar magnetic activity index by measuring the standard deviation of the whole time series, Sph. Because stellar variability can be related to convection, pulsations or magnetism, we need to ensure that this index mostly takes into account magnetic effects. We define another stellar magnetic activity index as the average of the standard deviation of shorter subseries which lengths are determined by the rotation period of the star. This way we can ensure that the measured photometric variability is related to starspots crossing the visible stellar disc. This new index combined with a time-frequency analysis based on the Morlet wavelets allows us to determine the existence of magnetic activity cycles. We measure magnetic indexes for the Sun and for 34 M dwarfs observed by Kepler. As expected, we obtain that the sample of M dwarfs studied in this work is much more active than the Sun. Moreover, we find a small correlation between the rotation period and the magnetic index. Finally, by combining a time-frequency analysis with phase diagrams, we discover the presence of long-lived features suggesting the existence of active longitudes on the surface of these stars.

  6. Advanced nanostructured materials and their application for improvement of sun-light harvesting and efficiency of solar cells

    Science.gov (United States)

    Dimova-Malinovska, D.

    2016-02-01

    This review describes the application of different nanostructured materials in solar cells technology for improvement of sun-light harvesting and their efficiency. Several approaches have recently been proposed to increase the efficiency of solar cells above the theoretical limit which are based on a “photon management” concept that employs such phenomena as: (i) down-conversion, and (ii) surface plasmon resonance effect (iii) decreasing of the loss due to the reflection of the radiation, (iv) increasing of the reflection from the back contact, v) increasing of the effective solar cells surface, etc. The results demonstrate the possibility for to increasing of light harvesting, short circuit current and efficiency by application of nanomaterials in thin film and hetero-junction (HJ) solar cells. The first promising results allow an expectation for application of advanced nanomaterials in the 3d generation solar cells.

  7. Covariant Hamiltonian representation of Noether's theorem and its application to SU(N) gauge theories

    CERN Document Server

    Struckmeier, Jürgen; Vasak, David

    2016-01-01

    We present the derivation of the Yang-Mills gauge theory based on the covariant Hamiltonian representation of Noether's theorem. As the starting point, we re-formulate our previous presentation of the canonical Hamiltonian derivation of Noether's theorem. The formalism is then applied to derive the Yang-Mills gauge theory. The Noether currents of U(1) and SU(N) gauge theories are derived from the respective infinitesimal generating functions of the pertinent symmetry transformations which maintain the form of the Hamiltonian.

  8. Application of the Langley plot for calibration of sun sensors for the Halogen Occultation Experiment (HALOE)

    Science.gov (United States)

    Moore, Alvah S., Jr.; Mauldin, L. ED, III; Stump, Charles W.; Reagan, John A.; Fabert, Milton G.

    1989-01-01

    The calibration of the Halogen Occultation Experiment (HALOE) sun sensor is described. This system consists of two energy-balancing silicon detectors which provide coarse azimuth and elevation control signals and a silicon photodiode array which provides top and bottom solar edge data for fine elevation control. All three detectors were calibrated on a mountaintop near Tucson, Ariz., using the Langley plot technique. The conventional Langley plot technique was modified to allow calibration of the two coarse detectors, which operate wideband. A brief description of the test setup is given. The HALOE instrument is a gas correlation radiometer that is now being developed for the Upper Atmospheric Research Satellite.

  9. Sun meter

    Science.gov (United States)

    Younskevicius, Robert E.

    1978-01-01

    A simple, inexpensive device for measuring the radiation energy of the sun impinging on the device. The measurement of the energy over an extended period of time is accomplished without moving parts or tracking mechanisms.

  10. The Sun

    CERN Document Server

    Golub, Leon

    2017-01-01

    Essential for life on earth and a major influence on our environment, the Sun is also the most fascinating object in the daytime sky. Every day we feel the effect of its coming and going – literally the difference between day and night. But figuring out what the Sun is, what it’s made of, why it glows so brightly, how old it is, how long it will last – all of these take thought and observation. Leon Golub and Jay M. Pasachoff offer an engaging and informative account of what scientists know about the Sun, and the history of these discoveries. Solar astronomers have studied the Sun over the centuries both for its intrinsic interest and in order to use it as a laboratory to reveal the secrets of other stars. The authors discuss the surface of the Sun, including sunspots and their eleven-year cycle, as well as the magnetism that causes them; the Sun’s insides, as studied mainly from seismic waves that astronomers record on its surface; the outer layers of the Sun that we see from Earth only at eclipses ...

  11. Spatial deconvolution of spectropolarimetric data: an application to quiet Sun magnetic elements

    Science.gov (United States)

    Quintero Noda, C.; Asensio Ramos, A.; Orozco Suárez, D.; Ruiz Cobo, B.

    2015-07-01

    Context. One of the difficulties in extracting reliable information about the thermodynamical and magnetic properties of solar plasmas from spectropolarimetric observations is the presence of light dispersed inside the instruments, known as stray light. Aims: We aim to analyze quiet Sun observations after the spatial deconvolution of the data. We examine the validity of the deconvolution process with noisy data as we analyze the physical properties of quiet Sun magnetic elements. Methods: We used a regularization method that decouples the Stokes inversion from the deconvolution process, so that large maps can be quickly inverted without much additional computational burden. We applied the method on Hinode quiet Sun spectropolarimetric data. We examined the spatial and polarimetric properties of the deconvolved profiles, comparing them with the original data. After that, we inverted the Stokes profiles using the Stokes Inversion based on Response functions (SIR) code, which allow us to obtain the optical depth dependence of the atmospheric physical parameters. Results: The deconvolution process increases the contrast of continuum images and makes the magnetic structures sharper. The deconvolved Stokes I profiles reveal the presence of the Zeeman splitting while the Stokes V profiles significantly change their amplitude. The area and amplitude asymmetries of these profiles increase in absolute value after the deconvolution process. We inverted the original Stokes profiles from a magnetic element and found that the magnetic field intensity reproduces the overall behavior of theoretical magnetic flux tubes, that is, the magnetic field lines are vertical in the center of the structure and start to fan when we move far away from the center of the magnetic element. The magnetic field vector inferred from the deconvolved Stokes profiles also mimic a magnetic flux tube but in this case we found stronger field strengths and the gradients along the line-of-sight are larger

  12. Organic Synthetic Advanced Materials for Optoelectronic and Energy Applications (at National Sun Yat-sen University) 

    Energy Technology Data Exchange (ETDEWEB)

    Yen, Hung-Ju [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Chemistry Division

    2016-11-14

    These slides cover Hung-Ju Yen's recent work in the synthesis and structural design of functional materials, which were further used for optoelectronic and energy applications, such as lithium ion battery, solar cell, LED, electrochromic, and fuel cells. This was for a job interview at National Sun Yat-sen University. The following topics are detailed: current challenges for lithium-ion batteries; graphene, graphene oxide and nanographene; nanographenes with various functional groups; fine tune d-spacing through organic synthesis: varying functional group; schematic view of LIBs; nanographenes as LIB anode; rate performance (charging-discharging); electrochromic technology; electrochromic materials; advantages of triphenylamine; requirement of electrochromic materials for practical applications; low driving voltage and long cycle life; increasing the electroactive sites by multi-step synthetic procedures; synthetic route to starburst triarylamine-based polyamide; electrochromism ranging from visible to NIR region; transmissive to black electrochromism; RGB and CMY electrochromism.

  13. Midnight sun

    Energy Technology Data Exchange (ETDEWEB)

    Brunger, A.P.; Lambert, S.B.; Gagnon, M.P.

    1990-09-01

    Midnight Sun, the University of Waterloo's solar-electric car, was designed and built by about 30 engineering, kinesiology and physics students for the GM Sunrayce USA held in July 1990. The car measures 2 m by 4.2 m, weighs 224 kg, can collect about 1000 W of solar electricity in full sun, and had a top speed of 79 km/h. The race took 11 days to cover the 1644 miles from the Epcot Center in Lake Buena Vista, Florida to the GM Technical Center in Warren, Michigan. Thirty-two cars, powered only by solar energy, competed in this race. Midnight Sun showed its potential during the race qualifying runs by completing the required qualifying course with the 12th fastest time of 52.83 seconds, and the 6th fastest trap speed of 63 km/h. During the Sunrayce, Midnight Sun came in second on day 1 of the race, tenth on day 6, and eighth on day 7, and was one of only 17 solar cars that were able to make it up the toughest hill in the race on day 8. The most serious problems encountered by the car were a weak rear suspension, power losses, and failure of bypass diodes in the photovoltaic array. Midnight Sun was in 17th place overall at the end of day 9. At about 11:00 am on day 10 in Ohio, the Waterloo car was moving at 60 km/h when it was bumped off the road by an out of control pickup truck. The solar car driver was not hurt. Despite the difficulties, the next day Midnight Sun was repaired and driven across the finish line at the ceremonial finish. After receiving time penalties for not completing the last day and a half of the race, Midnight Sun was awarded 24th place with an official cumulative time of 114 h 37 min 15 s. 4 figs., 4 tabs.

  14. Spatial deconvolution of spectropolarimetric data: an application to quiet Sun magnetic elements

    CERN Document Server

    Noda, C Quintero; Suárez, D Orozco; Cobo, B Ruiz

    2015-01-01

    Observations of the Sun from the Earth are always limited by the presence of the atmosphere, which strongly disturbs the images. A solution to this problem is to place the telescopes in space satellites, which produce observations without any (or limited) atmospheric aberrations. However, even though the images from space are not affected by atmospheric seeing, the optical properties of the instruments still limit the observations. In the case of diffraction limited observations, the PSF establishes the maximum allowed spatial resolution, defined as the distance between two nearby structures that can be properly distinguished. In addition, the shape of the PSF induce a dispersion of the light from different parts of the image, leading to what is commonly termed as stray light or dispersed light. This effect produces that light observed in a spatial location at the focal plane is a combination of the light emitted in the object at relatively distant spatial locations. We aim to correct the effect produced by t...

  15. Little Sun

    DEFF Research Database (Denmark)

    Ebbesen, Toke Riis

    2017-01-01

    the ideas of Alfred Gell’s anthropology of art and the indicative framework derived from Argentinian semiotician Juan Pablo Bonta and Jørn Guldberg. The toy-like solar lamp Little Sun by Olafur Eliasson and Frederik Ottesen is used as case that blends the registers of social design and art......, and as an example of how designers attempt to determine meaning potentials through design in a complex interplay of different strategies. In the final analysis, what characterise objects like Little Sun is seldom that they communicate their meanings in themselves, but instead rely on forceful mediations to gain...

  16. Little sun

    DEFF Research Database (Denmark)

    Ebbesen, Toke Riis

    2017-01-01

    the ideas of Alfred Gell’s anthropology of art and the indicative framework derived from Argentinian semiotician Juan Pablo Bonta and Jørn Guldberg. The toy-like solar lamp Little Sun by Olafur Eliasson and Frederik Ottesen is used as case that blends the registers of social design and art......, and as an example of how designers attempt to determine meaning potentials through design in a complex interplay of different strategies. In the final analysis, what characterise objects like Little Sun is seldom that they communicate their meanings in themselves, but instead rely on forceful mediations to gain...

  17. General formula for on-axis sun-tracking system and its application in improving tracking accuracy of solar collector

    Energy Technology Data Exchange (ETDEWEB)

    Chong, K.K.; Wong, C.W. [Faculty of Engineering and Science, Universiti Tunku Abdul Rahman, Off Jalan Genting Kelang, Setapak, 53300 Kuala Lumpur (Malaysia)

    2009-03-15

    Azimuth-elevation and tilt-roll tracking mechanism are among the most commonly used sun-tracking methods for aiming the solar collector towards the sun at all times. It has been many decades that each of these two sun-tracking methods has its own specific sun-tracking formula and they are not interrelated. In this paper, the most general form of sun-tracking formula that embraces all the possible on-axis tracking methods is presented. The general sun-tracking formula not only can provide a general mathematical solution, but more significantly it can improve the sun-tracking accuracy by tackling the installation error of the solar collector. (author)

  18. Signal Conditioning for the Kalman Filter: Application to Satellite Attitude Estimation with Magnetometer and Sun Sensors.

    Science.gov (United States)

    Esteban, Segundo; Girón-Sierra, Jose M; Polo, Óscar R; Angulo, Manuel

    2016-10-31

    Most satellites use an on-board attitude estimation system, based on available sensors. In the case of low-cost satellites, which are of increasing interest, it is usual to use magnetometers and Sun sensors. A Kalman filter is commonly recommended for the estimation, to simultaneously exploit the information from sensors and from a mathematical model of the satellite motion. It would be also convenient to adhere to a quaternion representation. This article focuses on some problems linked to this context. The state of the system should be represented in observable form. Singularities due to alignment of measured vectors cause estimation problems. Accommodation of the Kalman filter originates convergence difficulties. The article includes a new proposal that solves these problems, not needing changes in the Kalman filter algorithm. In addition, the article includes assessment of different errors, initialization values for the Kalman filter; and considers the influence of the magnetic dipole moment perturbation, showing how to handle it as part of the Kalman filter framework.

  19. Signal Conditioning for the Kalman Filter: Application to Satellite Attitude Estimation with Magnetometer and Sun Sensors

    Directory of Open Access Journals (Sweden)

    Segundo Esteban

    2016-10-01

    Full Text Available Most satellites use an on-board attitude estimation system, based on available sensors. In the case of low-cost satellites, which are of increasing interest, it is usual to use magnetometers and Sun sensors. A Kalman filter is commonly recommended for the estimation, to simultaneously exploit the information from sensors and from a mathematical model of the satellite motion. It would be also convenient to adhere to a quaternion representation. This article focuses on some problems linked to this context. The state of the system should be represented in observable form. Singularities due to alignment of measured vectors cause estimation problems. Accommodation of the Kalman filter originates convergence difficulties. The article includes a new proposal that solves these problems, not needing changes in the Kalman filter algorithm. In addition, the article includes assessment of different errors, initialization values for the Kalman filter; and considers the influence of the magnetic dipole moment perturbation, showing how to handle it as part of the Kalman filter framework.

  20. Sun Proof

    Centers for Disease Control (CDC) Podcasts

    2012-10-23

    In this podcast for kids, the Kidtastics talk about the harmful effects of the sun and how to protect yourself from it.  Created: 10/23/2012 by Centers for Disease Control and Prevention (CDC).   Date Released: 10/23/2012.

  1. Discover Space Weather and Sun's Superpowers: Using CCMC's innovative tools and applications

    Science.gov (United States)

    Mendoza, A. M. M.; Maddox, M. M.; Kuznetsova, M. M.; Chulaki, A.; Rastaetter, L.; Mullinix, R.; Weigand, C.; Boblitt, J.; Taktakishvili, A.; MacNeice, P. J.; Pulkkinen, A. A.; Pembroke, A. D.; Mays, M. L.; Zheng, Y.; Shim, J. S.

    2015-12-01

    Community Coordinated Modeling Center (CCMC) has developed a comprehensive set of tools and applications that are directly applicable to space weather and space science education. These tools, some of which were developed by our student interns, are capable of serving a wide range of student audiences, from middle school to postgraduate research. They include a web-based point of access to sophisticated space physics models and visualizations, and a powerful space weather information dissemination system, available on the web and as a mobile app. In this demonstration, we will use CCMC's innovative tools to engage the audience in real-time space weather analysis and forecasting and will share some of our interns' hands-on experiences while being trained as junior space weather forecasters. The main portals to CCMC's educational material are ccmc.gsfc.nasa.gov and iswa.gsfc.nasa.gov

  2. Sun L-Band Brightness Temperature Estimate from Soil Moisture and Ocean Salinity (SMOS) Mission: A Potential New Space Weather Applications for SMOS Data

    Science.gov (United States)

    Crapolicchio, Raffaele; Capolongo, Emiliano; Bigazzi, Alberto

    2016-08-01

    The paper presents the results of a validation study to assess the potentiality of the Level-1b (L1b) Soil Moisture and Ocean Salinity (SMOS) Sun Brightness Temperature (BT) as a valuable L-band radio signal useful in the space weather context. The validation exercise, done for both eruptive and quite/active Sun, focused on SMOS data availability, coverage and statistical analysis with respect to the United States Air Force (USAF) Radio Solar Telescope Network (RSTN) recorded data. In both cases the comparison of the two data sets has shown a strong timing correlation and an impressive burst amplitude correspondence. The paper also presents main advantages and some caveats in the use of the SMOS dataset. The results obtained encourage to pursue further studies both on the SMOS L1 processing algorithm refinement and on the usage of SMOS BT as an additional, independent and important source of information for space weather applications.

  3. Prototype of sun projector device

    Science.gov (United States)

    Ihsan; Dermawan, B.

    2016-11-01

    One way to introduce astronomy to public, including students, can be handled by solar observation. The widely held device for this purpose is coelostat and heliostat. Besides using filter attached to a device such as telescope, it is safest to use indirect way for observing the Sun. The main principle of the indirect way is deflecting the sun light and projecting image of the sun on a screen. We design and build a simple and low-cost astronomical device, serving as a supplement to increase public service, especially for solar observation. Without using any digital and intricate supporting equipment, people can watch and relish image of the Sun in comfortable condition, i.e. in a sheltered or shady place. Here we describe a design and features of our prototype of the device, which still, of course, has some limitations. In the future, this prototype can be improved for more efficient and useful applications.

  4. Sun and Sun Worship in Different Cultures

    Science.gov (United States)

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

    2014-10-01

    The Sun symbol is found in many cultures throughout history, it has played an important role in shaping our life on Earth since the dawn of time. Since the beginning of human existence, civilisations have established religious beliefs that involved the Sun's significance to some extent. As new civilisations and religions developed, many spiritual beliefs were based on those from the past so that there has been an evolution of the Sun's significance throughout cultural development. For comparing and finding the origin of the Sun we made a table of 66 languages and compared the roots of the words. For finding out from where these roots came from, we also made a table of 21 Sun Gods and Goddesses and proved the direct crossing of language and mythology.

  5. A unified normal mode approach to dynamic tides and its application to rotating Sun-like stars

    CERN Document Server

    Ivanov, P B; Chernov, S V

    2013-01-01

    We determine the response of a uniformly rotating star to tidal perturbations due to a companion. General periodic orbits and parabolic flybys are considered. We evaluate energy and angular momentum exchange rates as a sum of contributions from normal modes allowing for dissipative processes. We consider the case when the response is dominated by the contribution of an identifiable regular spectrum of low frequency modes, such as gravity modes and evaluate it in the limit of very weak dissipation. Our formalism may be applied both to Sun-like stars with radiative cores and convective envelopes and to more massive stars with convective cores and radiative envelopes. We provide general expressions for transfer of energy and angular momentum valid for an orbit with any eccentricity. Detailed calculations are made for Sun-like stars in the slow rotation regime where centrifugal distortion is neglected in the equilibrium and the traditional approximation is made for the normal modes. We use both a WKBJ procedure a...

  6. Sun's rap song

    Science.gov (United States)

    Hogan, M.; Lee, W.

    1995-07-01

    We present a rap song composed for the Sun, our star. This Sun's Rap Song can be utilized in classroom teaching to spark the students' interest and facilitate the students' learning of the relevant subjects.

  7. MedSun Reports

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Medical Product Safety Network (MedSun) is an adverse event reporting program launched in 2002. The primary goal for MedSun is to work collaboratively with the...

  8. MedSun Reports

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Medical Product Safety Network (MedSun) is an adverse event reporting program launched in 2002. The primary goal for MedSun is to work collaboratively with the...

  9. Application of the SKYRAD Improved Langley plot method for the in situ calibration of CIMEL Sun-sky photometers.

    Science.gov (United States)

    Campanelli, Monica; Estellés, Víctor; Tomasi, Claudio; Nakajima, Teruyuki; Malvestuto, Vincenzo; Martínez-Lozano, José Antonio

    2007-05-10

    The in situ procedure for determining the solar calibration constants, originally developed for the PREDE Sun-sky radiometers and based on a modified version of the Langley plot, was applied to a CIMEL instrument located in Valencia, Spain, not integrated into AERONET. Taking into account the different mechanical and electronic characteristics of the two radiometers, the method was adapted to the characteristics of the CIMEL instrument. The iterative procedure for the determination of the solar calibration constants was applied to a 3-year data set. The results were compared with the two sets of experimental calibration constants determined during this period using the standard Langley plot method. The agreement was found to be consistent with the experimental errors, and the method can definitely also be used to determine the solar calibration constant for the CIMEL instrument, improving its calibration. The method can be used provided the radiometer is previously calibrated for diffuse radiance using a standard lamp.

  10. The length of stay determinants for sun-and-sand tourism: An application for the Region of Murcia

    Directory of Open Access Journals (Sweden)

    Sánchez García, Juan Francisco

    2008-01-01

    Full Text Available While tourist arrivals increase annually in Spain, tourist average real expenditure has decreased significantly over the last few years, with important effects on tourism revenues. The process is clearly driven by the reduction of the length of stay of tourists at destinations, but surprisingly this variable has received little attention in the literature. We estimate a length of stay function for sun-and-sand tourists visiting the Region of Murcia over the period 2002-2006 using count data models. Our results show that both tourists’ personal and family characteristics together with economic variables (budget restrictions, income and prices are key factors in determining the duration of the stay. Quantitative identification of the determinants of a tourist’s length of stay could provide important guidelines for designing policies aimed at influencing length of stay in tourist‘s seaside destinations.

  11. Seasons by the Sun

    Science.gov (United States)

    Stark, Meri-Lyn

    2005-01-01

    Understanding the Sun has challenged people since ancient times. Mythology from the Greek, Inuit, and Inca cultures attempted to explain the daily appearance and nightly disappearance of the Sun by relating it to a chariot being chased across the sky. While people no longer believe the Sun is a chariot racing across the sky, teachers are still…

  12. Personal, Seasonal Suns

    Science.gov (United States)

    Sutley, Jane

    2010-01-01

    This article presents an art project designed for upper-elementary students to (1) imagine visual differences in the sun's appearance during the four seasons; (2) develop ideas for visually translating their personal experiences regarding the seasons to their sun drawings; (3) create four distinctive seasonal suns using colors and imagery to…

  13. Calibration and Application of an Array of Portable FTIR Spectrometers (EM27/SUN) for Detecting Greenhouse Gas Emissions

    Science.gov (United States)

    Frey, M.; Chelin, P.; Fratacci, T.; Schäfer, K.; Xueref-Remy, I.; Te, Y. V.; Jeseck, P.; Janssen, C.; Vogel, F. R.; Hase, F.; Blumenstock, T.; Kiel, M.; Sha, M. K.; Tu, Q.; Gross, J.; Gizaw, G.

    2015-12-01

    Anthropogenic global warming is mainly driven by a continuing increase of atmospheric greenhouse gases abundances. Precise knowledge of the variable atmospheric concentrations is of utmost importance for the quantification of sinks and sources of these gases. For global observations of column-averaged dry air mole fractions of greenhouse gases, satellite-borne instruments (e.g. GOSAT or OCO-2) are used. These instruments are validated against a network of ground-based high resolution Fourier-Transform Infrared (FTIR) spectrometers. This network, called TCCON (Total Carbon Column Observing Network), provides column-averaged abundances with reference precision and accuracy. However, these instruments are expensive, logistically demanding and stationary, so TCCON is less adequate for the quantification of sinks and sources on a regional scale. Recently the Karlsruhe Institute of Technology developed a portable FTIR spectrometer (EM27/SUN) together with Bruker Optics, Ettlingen. In addition to filling in the spatial gaps of the existing TCCON network for better global coverage, a set of these spectrometers can be arranged for detecting localized sinks and sources of greenhouse gases on a regional level, e.g. major cities or fracking areas. Due to their long lifetime, CO2 and CH4 emissions of these sources only introduce a small enhancement to the accumulated atmospheric background abundance. Therefore, high precision and stability are a prerequisite for the measurements. We present a rigorous calibration procedure for a quintuple of EM27/SUN spectrometers. Moreover, we show results from a test campaign conducted 2014 in the major city of Berlin, Germany. We demonstrate that the CO2 emissions of Berlin can be clearly identified in the observations. Measurement results are compared with a simple dispersion model. Finally, a comparison between Berlin data and data from a recent campaign in the megacity Paris is shown.

  14. Application of snow models to snow removal operations on the Going-to-the-Sun Road, Glacier National Park

    Science.gov (United States)

    Fagre, Daniel B.; Klasner, Frederick L.

    2000-01-01

    Snow removal, and the attendant avalanche risk for road crews, is a major issue on mountain highways worldwide. The Going-to-the-Sun Road is the only road that crosses Glacier National Park, Montana. This 80-km highway ascends over 1200m along the wall of a glaciated basin and crosses the continental divide. The annual opening of the road is critical to the regional economy and there is public pressure to open the road as early as possible. Despite the 67-year history of snow removal activities, few stat on snow conditions at upper elevations were available to guide annual planning for the raod opening. We examined statistical relationships between the opening date and nearby SNOTEL data on snow water equivalence (WE) for 30 years. Early spring SWE (first Monday in April) accounted for only 33% of the variance in road opening dates. Because avalanche spotters, used to warn heavy equipment operators of danger, are ineffective during spring storms or low-visibility conditions, we incorporated the percentage of days with precipitation during plowing as a proxy for visibility. This improved the model's predictive power to 69%/ A mountain snow simulator (MTSNOW) was used to calculate the depth and density of snow at various points along the road and field data were collected for comparison. MTSNOW underestimated the observed snow conditions, in part because it does not yet account for wind redistribution of snow. The severe topography of the upper reaches of the road are subjected to extensive wind redistribution of snow as evidence by the formation of "The Big Drift" on the lee side of Logan Pass.

  15. ON FELICITOUS CHARACTER OF GENERALIZED SUN-GRAPHS

    Institute of Scientific and Technical Information of China (English)

    YANG Si-hua; YAO Bing; YAO Ming

    2015-01-01

    Felicitous character of some generalized sun-graphs is investigated in this note, and furthermore the exact felicitous labellings of two classes of generalized sun-graphs are obtained by analyzing the structures of the generalized sun-graphs. And the constructed graph theory models in coding theory, communication networks, logistics and other aspects have important applications.

  16. Sun Safe Mode Controller Design for LADEE

    Science.gov (United States)

    Fusco, Jesse C.; Swei, Sean S. M.; Nakamura, Robert H.

    2015-01-01

    This paper presents the development of sun safe controllers which are designed to keep the spacecraft power positive and thermally balanced in the event an anomaly is detected. Employed by NASA's Lunar Atmosphere and Dust Environment Explorer (LADEE), the controllers utilize the measured sun vector and the spacecraft body rates for feedback control. To improve the accuracy of sun vector estimation, the least square minimization approach is applied to process the sensor data, which is proven to be effective and accurate. To validate the controllers, the LADEE spacecraft model engaging the sun safe mode was first simulated and then compared with the actual LADEE orbital fight data. The results demonstrated the applicability of the proposed sun safe controllers.

  17. Sun-Earth Days

    Science.gov (United States)

    Thieman, J.; Ng, C.; Lewis, E.; Cline, T.

    2010-08-01

    Sun-Earth Day is a well-coordinated series of programs, resources and events under a unique yearly theme highlighting the fundamentals of heliophysics research and missions. A menu of activities, conducted throughout the year, inspire and educate participants. Sun-Earth Day itself can vary in date, but usually is identified by a celebration on or near the spring equinox. Through the Sun-Earth Day framework we have been able to offer a series of coordinated events that promote and highlight the Sun, its connection to Earth and the other planets. Sun-Earth Day events are hosted by educators, museums, amateur astronomers and scientists and occur at schools, community groups, parks, planetaria and science centers around the globe. Sun-Earth Day raises the awareness and knowledge of formal and informal education audiences concerning space weather and heliophysics. By building on the success of Sun-Earth Day yearly celebrations, we seek to affect people of all backgrounds and ages with the wonders of heliophysics science, discovery, and exploration in ways that are both tangible and meaningful to their lives.

  18. Optimal control of sun tracking solar concentrators

    Science.gov (United States)

    Hughes, R. O.

    1979-01-01

    Application of the modern control theory to derive an optimal sun tracking control for a point focusing solar concentrator is presented. A standard tracking problem converted to regulator problem using a sun rate input achieves an almost zero steady state tracking error with the optimal control formulation. However, these control techniques are costly because optimal type algorithms require large computing systems, thus they will be used mainly as comparison standards for other types of control algorithms and help in their development.

  19. Sun and Sjogren's Syndrome

    Science.gov (United States)

    Patient Education Sheet The Sun and Sjögren’s Syndrome The SSF thanks Mona Z. Mofid, MD, FAAD, Diplomate, American Board of Dermatology, and Medical Director, American Melanoma Foundation, San Diego, California, ...

  20. Why Study the Sun?

    Indian Academy of Sciences (India)

    Arvind Bhatnagar

    2006-06-01

    In this presentation we briefly describe the Sun through large number of illustrations and pictures of the Sun taken from early times to the present day space missions. The importance of the study of the Sun is emphasized as it is the nearest star which presents unparallelled views of surface details and numerous phenomena. Our Sun offers a unique celestial laboratory where a large variety of phenomena take place, ranging in temporal domain from a few milliseconds to several decades, in spatial domain from a few hundred kilometers to thousands of kilometers, and in the temperature domain from a few thousand degrees to several million degrees. Its mass motion ranges from thousandths to thousands of kilometers per second. Such an object provides us with a unique laboratory to study the state of matter in the Universe. The existing solar ground-based and space missions have already revealed several mysteries of the outer environment of our Sun and much more is going to come in the near future from planned new sophisticated ground-based solar telescopes and Space missions. The new technique of helioseismology has unravelled many secrets of the solar interior and has put the Standard Solar Model (SSM) on firm footing. The long-standing problem of solar neutrinos has been recently sorted out, and even the ‘back side’ view of the Sun can be seen using the technique of holographic helioseismology.

  1. The Sun and Earth

    Science.gov (United States)

    Gopalswamy, Natchimuthuk

    2012-01-01

    Thus the Sun forms the basis for life on Earth via the black body radiation it emits. The Sun also emits mass in the form of the solar wind and the coronal mass ejections (CMEs). Mass emission also occurs in the form of solar energetic particles (SEPs), which happens during CMEs and solar flares. Both the mass and electromagnetic energy output of the Sun vary over a wide range of time scales, thus introducing disturbances on the space environment that extends from the Sun through the entire heliosphere including the magnetospheres and ionospheres of planets and moons of the solar system. Although our habitat is located in the neutral atmosphere of Earth, we are intimately connected to the non-neutral space environment starting from the ionosphere to the magnetosphere and to the vast interplanetary space. The variability of the solar mass emissions results in the interaction between the solar wind plasma and the magnetospheric plasma leading to huge disturbances in the geospace. The Sun ionizes our atmosphere and creates the ionosphere. The ionosphere can be severely disturbed by the transient energy input from solar flares and the solar wind during geomagnetic storms. The complex interplay between Earth's magnetic field and the solar magnetic field carried by the solar wind presents varying conditions that are both beneficial and hazardous to life on earth. This seminar presents some of the key aspects of this Sun-Earth connection that we have learned since the birth of space science as a scientific discipline some half a century ago.

  2. Sun-synchronous satellite orbit determination

    Science.gov (United States)

    Ma, Der-Ming; Zhai, Shen-You

    2004-02-01

    The linearized dynamic equations used for on-board orbit determination of Sun-synchronous satellite are derived. Sun-synchronous orbits are orbits with the secular rate of the right ascension of the ascending node equal to the right ascension rate of the mean sun. Therefore the orbit is no more a closed circle but a tight helix about the Earth. In the paper, instead of treating the orbit as a closed circle, the actual helix orbit is taken as nominal trajectory. The details of the linearized equations of motion for the satellite in the Sun-synchronous orbit are derived. The linearized equations are obtained by perturbing the Keplerian motion with the J2 correction and the effect of sun's attraction being neglected. Combined with the GPS navigation equations, the Kalman filter formulation is given. The particular application considered is the circular Sun-synchronous orbit with the altitude of 800 km and inclination of 98.6°. The numerical example simulated by MATLAB® shows that only the pseudo-range data used in the algorithm still gives acceptable results. Based on the simulation results, we can use the on-board GPS receivers' signal only as an alternative to determine the orbit of Sun-Synchronous satellite and therefore circumvents the need for extensive ground support.

  3. Lessons from the Sun

    Directory of Open Access Journals (Sweden)

    Robitaille P.-M.

    2011-07-01

    Full Text Available In this brief note, the implications of a condensed Sun will be examined. A celestial body composed of liquid metallic hydrogen brings great promise to astronomy, relative to understanding thermal emission and solar structure. At the same time, as an incom- pressible liquid, a condensed Sun calls into question virtually everything which is cur- rently believed with respect to the evolution and nature of the stars. Should the Sun be condensed, then neutron stars and white dwarfs will fail to reach the enormous densities they are currently believed to possess. Much of cosmology also falls into question, as the incompressibility of matter curtails any thought that a primordial atom once existed. Aging stars can no longer collapse and black holes will know no formative mechanism. A condensed Sun also hints that great strides must still be made in understanding the nature of liquids. The Sun has revealed that liquids possess a much greater potential for lattice order than previously believed. In addition, lessons may be gained with regards to the synthesis of liquid metallic hydrogen and the use of condensed matter as the basis for initiating fusion on Earth.

  4. Magnetohydrodynamics of the sun

    CERN Document Server

    Priest, Eric

    2014-01-01

    Magnetohydrodynamics of the Sun is a completely new up-to-date rewrite from scratch of the 1982 book Solar Magnetohydrodynamics, taking account of enormous advances in understanding since that date. It describes the subtle and complex interaction between the Sun's plasma atmosphere and its magnetic field, which is responsible for many fascinating dynamic phenomena. Chapters cover the generation of the Sun's magnetic field by dynamo action, magnetoconvection and the nature of photospheric flux tubes such as sunspots, the heating of the outer atmosphere by waves or reconnection, the structure of prominences, the nature of eruptive instability and magnetic reconnection in solar flares and coronal mass ejections, and the acceleration of the solar wind by reconnection or wave-turbulence. It is essential reading for graduate students and researchers in solar physics and related fields of astronomy, plasma physics and fluid dynamics. Problem sets and other resources are available at www.cambridge.org/9780521854719.

  5. The Sun's Supergranulation

    CERN Document Server

    Rieutord, Michel

    2010-01-01

    The Sun's supergranulation refers to a physical pattern covering the surface of the quiet Sun with a typical horizontal scale of approximately 30000km. Its most noticeable observable signature is as a fluctuating velocity field whose components are mostly horizontal. Supergranulation was discovered more than fifty years ago, however explaining why and how it originates still represents one of the main challenges of modern solar physics. A lot of work has been devoted to the subject over the years, but observational constraints, conceptual difficulties and numerical limitations have all concurred to prevent a detailed understanding of the supergranulation phenomenon so far. With the advent of 21st century supercomputing resources and the availability of unprecedented high-resolution observations of the Sun, the solar community has now reached a stage at which key progress can be made on this question. A unifying strategy between observations and modeling is more than ever required for this to be possible. The ...

  6. Sun, Earth and Sky

    Science.gov (United States)

    Lang, Kenneth R.

    1995-01-01

    The Sun is enveloped by a hot, tenuous million-degree corona that expands to create a continuous solar wind that sweeps past all the planets and fills the heliosphere. The solar wind is modulated by strong gusts that are initiated by powerful explosions on the Sun, including solar flares and coronal mass ejections. This dynamic, invisible outer atmosphere of the Sun is currently under observation with the soft X-ray telescope aboard the Yohkoh spacecraft, whose results are presented. We also show observations from the Ulysses spacecraft that is now passing over the solar pole, sampling the solar wind in this region for the first time. Two other spacecraft, Voyager 1 and 2, have recently detected the outer edge of the invisible heliosphere, roughly halfway to the nearest star. Magnetic solar activity, the total radiative output from the Sun, and the Earth's mean global surface temperature all vary with the 11-year sunspot cycle in which the total number of sunspots varies from a maximum to a minimum and back to a maximum again in about 11 years. The terrestrial magnetic field hollows out a protective magnetic cavity, called the magnetosphere, within the solar wind. This protection is incomplete, however, so the Sun feeds an unseen world of high-speed particles and magnetic fields that encircle the Earth in space. These particles endanger spacecraft and astronauts, and also produce terrestrial aurorae. An international flotilla of spacecraft is now sampling the weak points in this magnetic defense. Similar spacecraft have also discovered a new radiation belt, in addition to the familiar Van Allen belts, except fed by interstellar ions instead of electrons and protons from the Sun.

  7. Piece of the sun

    CERN Document Server

    Wayne, Teddy

    2015-01-01

    Our rapidly industrialising world has an insatiable hunger for energy, and conventional sources are struggling to meet demand. Oil is running out, coal is damaging our climate, many nations are abandoning nuclear, yet solar, wind and water will never be a complete replacement. The solution, says Daniel Clery in this deeply researched and revelatory book, is to be found in the original energy source: the Sun itself. There, at its centre, the fusion of 630 million tonnes of hydrogen every second generates an unfathomable amount of energy. By replicating even a tiny piece of the Sun's power

  8. Near-Sun asteroids

    Science.gov (United States)

    Emel'yanenko, V. V.

    2017-01-01

    As follows from dynamical studies, in the course of evolution, most near-Earth objects reach orbits with small perihelion distances. Changes of the asteroids in the vicinity of the Sun should play a key role in forming the physical properties, size distribution, and dynamical features of the near-Earth objects. Only seven of the discovered asteroids are currently moving along orbits with perihelion distances q orbits farther from the Sun. In this study, we found asteroids that have been recently orbiting with perihelion distances q orbits for hundreds to tens of thousands of years. To carry out astrophysical observations of such objects is a high priority.

  9. The SUN S TRAVELS

    Institute of Scientific and Technical Information of China (English)

    Robert; Louis; Stevenson

    2005-01-01

    The sun is not a-bed, when I At night upon my pillow lie; Stilt round the earth his Way he takes, And morning after morning makes. White here at home, in shining day, We round the sunny garden play, Each tittle Indian sleepy - head Is being kissed and put to bed. And When at eve I rise from tea, Day dawns beyond the Atlantic Sea; And all the children in the West Are getting up and being dressed.The SUN'S TRAVELS@Robert Louis Stevenson

  10. Maximising the sun

    CSIR Research Space (South Africa)

    Conradie, Dirk CU

    2010-08-01

    Full Text Available South Africa is blessed with some of the best quality solar radiation in the world. In the light of this many exciting opportunities exist to utilize the sun to its full potential in the design of energy efficient buildings. Passive solar buildings...

  11. Sun Ultra 5

    CERN Multimedia

    1998-01-01

    The Sun Ultra 5 is a 64-bit personal computer based on the UltraSPARC microprocessor line at a low price. The Ultra 5 has been declined in several variants: thus, some models have a processor with less cache memory to further decrease the price of the computer.

  12. The Toboggan Sun

    NARCIS (Netherlands)

    Davidson, WPS; van der Werf, SY

    2005-01-01

    Special variants of the Novaya Zemlya effect may arise from localized temperature inversions that follow the height profile of hills or mountains. Rather than following its natural path, the rising or setting Sun may, under such circumstances, appear to slide along a distant mountain slope. We found

  13. Go Sun Smart

    Science.gov (United States)

    Scott, Michael D.; Buller, David B.; Walkosz, Barbara J.; Andersen, Peter A.; Cutter, Gary R.; Dignan, Mark B.

    2008-01-01

    This is the story of Go Sun Smart, a worksite wellness program endorsed by the North American Ski Area Association and funded by the National Cancer Institute. Between 2000 and 2002 we designed and implemented a large-scale worksite intervention at over 300 ski resorts in North America with the objective of reducing ski area employees and guests…

  14. Sun, Earth and Sky

    CERN Document Server

    Lang, Kenneth R

    2006-01-01

    This Second Edition of Sun, Earth and Sky updates the popular text by providing comprehensive accounts of the most recent discoveries made by five modern solar spacecraft during the past decade. Their instruments have used sound waves to peer deep into the Sun’s inner regions and measure the temperature of its central nuclear reactor, and extended our gaze far from the visible Sun to record energetic outbursts that threaten Earth. Breakthrough observations with the underground Sudbury Neutrino Observatory are also included, which explain the new physics of ghostly neutrinos and solve the problematic mismatch between the predicted and observed amounts of solar neutrinos. This new edition of Sun, Earth and Sky also describes our recent understanding of how the Sun’s outer atmosphere is heated to a million degrees, and just where the Sun’s continuous winds come from. As humans we are more intimately linked with our life-sustaining Sun than with any other astronomical object, and the new edition therefore p...

  15. Our Explosive Sun

    Science.gov (United States)

    Brown, D. S.

    2009-01-01

    The Sun's atmosphere is a highly structured but dynamic place, dominated by the solar magnetic field. Hot charged gas (plasma) is trapped on lines of magnetic force that can snap like an elastic band, propelling giant clouds of material out into space. A range of ground-based and space-based solar telescopes observe these eruptions, particularly…

  16. Clothing reduces the sun protection factor of sunscreens

    DEFF Research Database (Denmark)

    Beyer, Ditte Maria; Faurschou, Annesofie; Haedersdal, M

    2010-01-01

    Individuals are recommended to wait for 20 min following sunscreen application before dressing. However, this is probably seldom done in daily life, and therefore we investigated how dressing earlier than 20 min after application affected the sun protection factor (SPF)....

  17. Ra: The Sun for Science and Humanity

    Science.gov (United States)

    1996-01-01

    To guide the development of the Ra Strategic Framework, we defined scientific and applications objectives. For our primary areas of scientific interest, we choose the corona, the solar wind, the Sun's effect on the Earth, and solar theory and model development. For secondary areas of scientific interest, we selected sunspots, the solar constant, the Sun's gravitational field, helioseismology and the galactic cosmic rays. We stress the importance of stereoscopic imaging, observations at high spatial, spectral, and temporal resolutions, as well as of long duration measurements. Further exploration of the Sun's polar regions is also important, as shown already by the Ulysses mission. From an applications perspective, we adopted three broad objectives that would derive complementary inputs for the Strategic Framework. These were to identify and investigate: possible application spin-offs from science missions, possible solar-terrestrial missions dedicated to a particular application, and possible future applications that require technology development. The Sun can be viewed as both a source of resources and of threats. Our principal applications focus was that of threat mitigation, by examining ways to improve solar threat monitoring and early warning systems. We compared these objectives to the mission objectives of past, current, and planned international solar missions. Past missions (1962-1980) seem to have been focused on improvement of scientific knowledge, using multiple instrument spacecraft. A ten year gap followed this period, during which the results from previous missions were analyzed and solar study programmes were prepared in international organizations. Current missions (1990-1996) focus on particular topics such as the corona, solar flares, and coronal mass ejections. In planned missions, Sun/Earth interactions and environmental effects of solar activity are becoming more important. The corona is the centre of interest of almost all planned missions

  18. Stars resembling the Sun

    Science.gov (United States)

    Cayrel de Strobel, G.

    This review is primarily directed to the question whether photometric solar analogues remain such when subjected to detailed spectroscopic analyses and interpreted with the help of internal stucture models. In other words, whether the physical parameters: mass, chemical composition, age (determining effective temperature and luminosity), chromospheric activity, equatorial rotation, lithium abundance, velocity fields etc., we derive from the spectral analysis of a photometric solar analogue, are really close to those of the Sun. We start from 109 photometric solar analogues extracted from different authors. The stars selected had to satisfy three conditions: i) their colour index (B-V) must be contained in the interval: Δ (B-V) = 0.59-0.69, ii) they must possess a trigonometric parallax, iii) they must have undergone a high resolution detailed spectroscopic analysis. First, this review presents photometric and spectrophotometric researches on solar analogues and recalls the pionneering work on these stars by the late Johannes Hardorp. After a brief discussion on low and high resolution spectroscopic researches, a comparison is made between effective temperatures as obtained, directly, from detailed spectral analyses and those obtained, indirectly, from different photometric relations. An interesting point in this review is the discussion on the tantalilizing value of the (B-V)solar of the Sun, and the presentation of a new reliable value of this index. A short restatement of the kinematic properties of the sample of solar analogues is also made. And, finally, the observational ( T eff, M bol) diagram, obtained with 99 of the initially presented 109 analogues, is compared to a theoretical ( T eff, M bol) diagram. This latter has been constructed with a grid of internal structure models for which, (very important for this investigation), the Sun was used as gauge. In analysing the position, with respect to the Sun, of each star we hoped to find a certain number of

  19. Clothing reduces the sun protection factor of sunscreens

    DEFF Research Database (Denmark)

    Beyer, Ditte Maria; Faurschou, Annesofie; Haedersdal, M

    2010-01-01

    Individuals are recommended to wait for 20 min following sunscreen application before dressing. However, this is probably seldom done in daily life, and therefore we investigated how dressing earlier than 20 min after application affected the sun protection factor (SPF).......Individuals are recommended to wait for 20 min following sunscreen application before dressing. However, this is probably seldom done in daily life, and therefore we investigated how dressing earlier than 20 min after application affected the sun protection factor (SPF)....

  20. SCIENCE OF SUN PHOTOMETRY

    Directory of Open Access Journals (Sweden)

    Alexandru Dan Toma

    2013-07-01

    Full Text Available Typically, the total amount of gases and particles in a column of atmosphere cannot be determined from measurements just at Earth's surface, by a single measurement essentially at the bottom of the atmosphere column. Balloons, airplanes, and rockets are all used to perform direct measurements in the atmosphere at altitudes up to and beyond the stratosphere. Satellite-based instruments provide global views, but it is difficult to infer surface and column distributions from space-based measurements, so such measurements must still be supplemented by ground-based measurements. Sun photometry is an important way of probing the atmosphere from the ground to measure the effects of the atmosphere on Sun radiation crossing through the atmosphere to Earth's surface. These indirect technique provide information about the entire atmosphere above the observer, not just the atmosphere that can be sampled directly close to Earth's surface.

  1. How hot is the sun

    Institute of Scientific and Technical Information of China (English)

    刘超

    2001-01-01

    Do you know how hot thesun is? There are no solidsor liquids on the sun. Why not? The temperature onoutside the sun is more than 10, 000℃, and that at the centre is about 20, 000, 000℃.The sun is so hot that all thesolids and all the liquids havebeen turned into gases.

  2. The sun, our star

    Science.gov (United States)

    Noyes, R. W.

    Observational data, analytical models, and instrumentation used to study the sun and its evolution are detailed, and attention is given to techniques for converting solar energy to useful power on earth. The star ignited when the mutual gravitational attractions of dust and vapor in a primordial cloud in the Galaxy caused an in-rush of accelerating particles which eventually became dense enough to ignite. The heat grew until inward rushing matter was balanced by outward moving radiative forces. The planets formed from similar debris, and solar radiation is suggested to have triggered the chemical reactions giving rise to life on earth. Visual, spectroscopic, coronagraphic, and UV observations of the sun from the ground and from spacecraft, particularly Skylab, are described, together with features of the solar surface, magnetic field, sunspots, and coronal loops. Models for the processes that occur in the solar interior are explored, as are the causes of solar flares. Attention is given to solar cells, heliostat arrays, wind turbines, and water turbines as means to convert, either directly or indirectly, the earth-bound solar energy to electrical and thermal power. Finally, the life cycle of the sun, about 9 billion yr in duration, is summarized, noting the current status of midlife.

  3. 槽式太阳能跟踪控制系统的研制及应用%Development and application of sun-tracking control system for parabolic trough solar collector

    Institute of Scientific and Technical Information of China (English)

    王金平; 王军; 冯炜; 王登文; 张耀明

    2015-01-01

    Concentrating Solar Power (CSP) systems use lenses or mirrors and tracking systems to focus a large area of sunlight into a small beam. Heat transfer fluid is heated by sun rays through the solar concentrator, then used as a heat source for a conventional power plant. A wide range of concentrating technologies has existed; the most developed are parabolic trough collector (PTC), linear fresnel reflector system (LF), power tower, and dish/engine system (DE). Parabolic trough collector is considered as one of the most mature applications of solar energy in these four technologies, which makes it worth developing. Sun-tracking system plays an important role in the development of solar energy applications, especially for the high solar concentration systems that directly convert the solar energy into thermal or electrical energy. High accuracy of sun-tracking is required to ensure that the solar collector is capable of harnessing the maximum solar energy throughout the day. Compared to fixed systems, power output of single-axis and dual-axis tracking systems can increase by 25% and 41% respectively under the same condition. It is clear that an accurate sun-tracking control system can make solar collectors receive more solar radiation energy to improve the solar energy utilization. A good sun-tracking system must be reliable and able to track the sun at the right angle even in the periods of cloud cover. Although the tracking system is more complex and costs higher than the fixed system, increasing the annual output power can reduce cost effectively. As for photoelectric tracking mode, a sun position sensor is used to provide feedback signals to judge where the sun is, but they don’t work on cloudy days because of the lower sensitivity. The stability of the solar tracking system is a key factor to obtain the maximum sunlight from parabolic trough collector. In order to improve tracking stability and accuracy of the parabolic trough collector sun-tracking control

  4. Review - The Sun Rises

    Directory of Open Access Journals (Sweden)

    Mark Bender

    2012-12-01

    Full Text Available Review of: Blackburn, Stuart H. 2010. The Sun Rises: A Shaman's Chant, Ritual Exchange and Fertility in the Apatani Valley. Leiden: Brill. xvii+401. Color and black and white photographs, maps. ISBN: 9789-0041-7578-5 (hardcover, 97USD. The Sun Rises is a model study contextualizing an oral narrative tradition in the social and ritual fabric of a remote community in northeast India. In many ways a companion volume to Himalayan Tribal Tales (Blackburn 2008, the text presents the first substantial translation of a key ritual text of the Apantani Valley dwellers in Arunachal Pradesh, located on the contested border between China (Tibet and India. The Apatani speak a Tibeto-Burman language, practice intensive rice agriculture in carefully terraced fields, and number about 35,000. Their clans populate several centuries-old villages. Until recently, they were separated from the lowlands of Assam and surrounded only by peoples practicing various forms of shifting agriculture. The valley dwellers have increasingly encountered modernization over the last few decades, including Indian and global popular culture, and Christianity. The heart of this book is a chant of nineteen segments.

  5. Eruptions from the Sun

    Science.gov (United States)

    Kohler, Susanna

    2015-11-01

    The Sun often exhibits outbursts, launching material from its surface in powerful releases of energy. Recent analysis of such an outburst captured on video by several Sun-monitoring spacecraft may help us understand the mechanisms that launch these eruptions.Many OutburstsSolar jets are elongated, transient structures that are thought to regularly release magnetic energy from the Sun, contributing to coronal heating and solar wind acceleration. Coronal mass ejections (CMEs), on the other hand, are enormous blob-like explosions, violently ejecting energy and mass from the Sun at incredible speeds.But could these two types of events actually be related? According to a team of scientists at the University of Science and Technology of China, they may well be. The team, led by Jiajia Liu, has analyzed observations of a coronal jet that they believe prompted the launch of a powerful CME.Observing an ExplosionGif of a movie of the CME, taken by the Solar Dynamics Observatorys Atmospheric Imaging Assembly at a wavelength of 304. The original movie can be found in the article. [Liu et al.]An army of spacecraft was on hand to witness the event on 15 Jan 2013 including the Solar Dynamics Observatory (SDO), the Solar and Heliospheric Observatory (SOHO), and the Solar Terrestrial Relations Observatory (STEREO). The instruments on board these observatories captured the drama on the northern limb of the Sun as, at 19:32 UT, a coronal jet formed. Just eight minutes later, a powerful CME was released from the same active region.The fact that the jet and CME occurred in the same place at roughly the same time suggests theyre related. But did the initial motions of the CME blob trigger the jet? Or did the jet trigger the CME?Tying It All TogetherIn a recently published study, Liu and collaborators analyzed the multi-wavelength observations of this event to find the heights and positions of the jet and CME. From this analysis, they determined that the coronal jet triggered the release

  6. Here comes the sun...; Here comes the sun...

    Energy Technology Data Exchange (ETDEWEB)

    Best, Robert [Centro de Investigacion en Energia (CIE) de la UNAM, Temixco, Morelos (Mexico)

    2010-07-01

    It sounds a bit strange that you can use solar energy to maintain or refrigerate products or spaces below the ambient temperature, because we know that something that makes the sun is heating; but yes indeed, the sun can produce cold, and in addition without polluting, and without consuming conventional energy. In this document are mentioned the various research projects on solar cooling that have been made in the Energy Research Center at the Universidad Nacional Autonoma de Mexico such as the thermo-chemical intermittent refrigerator, the geothermal cooling demonstration system in Mexicali, B.C., the GAX system for air conditioning, the ice producer intermittent solar refrigerator, the continuous solar refrigerator, the refrigeration by ejection-compression. It also mentions the functioning of heat pumps and the process of solar drying applications in agricultural products. [Spanish] Suena un poco extrano que se pueda utilizar la energia solar para mantener o refrigerar productos o espacios por debajo de la temperatura ambiente, ya que sabemos que algo que hace el sol es calentar; pero si, el sol puede producir frio, y ademas sin contaminar y sin consumir energia convencional. En este documento se mencionan las diferentes investigaciones sobre refrigeracion solar que se han realizado en el Centro de Investigacion en Energia de la Universidad Nacional Autonoma de Mexico como el refrigerador termoquimico intermitente, el sistema demostrativo de refrigeracion geotermico en Mexicali, B.C., el sistema GAX para aire acondicionado, el refrigerador solar intermitente productor de hielo, el refrigerador continuo solar, la refrigeracion por eyecto-compresion. Tambien se menciona el funcionamiento de las bombas de calor y el proceso de secado solar de aplicacion en productos agropecuarios.

  7. The validated sun exposure questionnaire

    DEFF Research Database (Denmark)

    Køster, B; Søndergaard, J; Nielsen, J B

    2017-01-01

    Few questionnaires used in monitoring sun-related behavior have been tested for validity. We established criteria validity of a developed questionnaire for monitoring population sun-related behavior. During May-August 2013, 664 Danes wore a personal electronic UV-dosimeter for one week...... that measured the outdoor time and dose of erythemal UVR exposure. In the following week, they answered a questionnaire on their sun-related behavior in the measurement week. Outdoor time measured by dosimetry correlated strongly with both outdoor time and the developed exposure scale measured....... The weekly sunburn fraction correlated strongly with the number of ambient sun hours (r=0.73, p

  8. The Sun, Mercury, and Venus

    CERN Document Server

    Elkins-Tanton, Linda T

    2010-01-01

    The Messenger mission to Mercury opened a new window into the inner solar system. In 2008, this mission began a number of years of flybys, culminating in an orbital insertion around Mercury and producing unparalleled observations about this mysterious innermost planet. Mercury orbits so close to the Sun, from the point of view of Earth, that seeing it from the Earth against the Sun's glare is a great challenge. At the same time, the huge gravitational force of the Sun makes it a challenge to put a mission on Mercury without losing it into the Sun. Now, with heightened understanding of Mercury,

  9. The Rapidly Rotating Sun

    Science.gov (United States)

    Hanasoge, Shravan M.; Duvall, Thomas L., Jr.; Sreenivasan, Katepalli R.

    2012-01-01

    Convection in the solar interior is thought to comprise structures at a continuum of scales, from large to small. This conclusion emerges from phenomenological studies and numerical simulations though neither covers the proper range of dynamical parameters of solar convection. In the present work, imaging techniques of time-distance helioseismology applied to observational data reveal no long-range order in the convective motion. We conservatively bound the associated velocity magnitudes, as a function of depth and the spherical-harmonic degree l to be 20-100 times weaker than prevailing estimates within the wavenumber band l ux of a solar luminosity outwards? The Sun is seemingly a much faster rotator than previously thought, with advection dominated by Coriolis forces at scales l < 60.

  10. Sun light European Project

    Science.gov (United States)

    Soubielle, Marie-Laure

    2015-04-01

    2015 has been declared the year of light. Sunlight plays a major role in the world. From the sunbeams that heat our planet and feed our plants to the optical analysis of the sun or the modern use of sun particles in technologies, sunlight is everywhere and it is vital. This project aims to understand better the light of the Sun in a variety of fields. The experiments are carried out by students aged 15 to 20 in order to share their discoveries with Italian students from primary and secondary schools. The experiments will also be presented to a group of Danish students visiting our school in January. All experiments are carried out in English and involve teams of teachers. This project is 3 folds: part 1: Biological project = what are the mechanisms of photosynthesis? part 2: Optical project= what are the components of sunlight and how to use it? part 3: Technical project= how to use the energy of sunlight for modern devices? Photosynthesis project Biology and English Context:Photosynthesis is a process used by plants and other organisms to convert light energy, normally from the Sun, into chemical energy that can later fuel the organisms' activities. This chemical energy is stored in molecules which are synthesized from carbon dioxide and water. In most cases, oxygen is released as a waste product. Most plants perform photosynthesis. Photosynthesis maintains atmospheric oxygen levels and supplies all of the organic compounds and most of the energy necessary for life on Earth. Outcome: Our project consists in understanding the various steps of photosynthesis. Students will shoot a DVD of the experiments presenting the equipments required, the steps of the experiments and the results they have obtained for a better understanding of photosynthesis Digital pen project Electricity, Optics and English Context: Sunlight is a complex source of light based on white light that can be decomposed to explain light radiations or colours. This light is a precious source to create

  11. Physics of the sun

    CERN Document Server

    Holzer, Thomas; Mihalas, Dimitri; Ulrich, Roger

    1986-01-01

    This volume, together with its two companion volumes, originated in a study commis­ sioned by the United States National Academy of Sciences on behalf of the National Aeronautics and Space Administration. A committee composed of Tom Holzer, Dimitri Mihalas, Roger Ulrich and myself was asked to prepare a comprehensive review of current knowledge concerning the physics of the sun. We were fortunate in being able to persuade many distinguished scientists to gather their forces for the preparation of 21 separate chapters covering not only solar physics but also relevant areas of astrophysics and solar-terrestrial relations. It proved necessary to divide the chapters into three separate volumes that cover three different aspects of solar physics. Volumes 1 and 2 are concerned with 'The Solar Interior' and with 'The Solar Atmosphere'. This volume, devoted to 'Astrophysics and Solar-Terrestrial Relations', focuses on problems of solar physics from these two different but complementary perspectives. The emphasis thr...

  12. The Sun in Time: Activity and Environment

    Directory of Open Access Journals (Sweden)

    Güdel Manuel

    2007-12-01

    Full Text Available The Sun's magnetic activity has steadily declined during its main-sequence life. While the solar photospheric luminosity was about 30% lower 4.6 Gyr ago when the Sun arrived on the main sequence compared to present-day levels, its faster rotation generated enhanced magnetic activity; magnetic heating processes in the chromosphere, the transition region, and the corona induced ultraviolet, extreme-ultraviolet, and X-ray emission about 10, 100, and 1000 times, respectively, the present-day levels, as inferred from young solar-analog stars. Also, the production rate of accelerated, high-energy particles was orders of magnitude higher than in present-day solar flares, and a much stronger wind escaped from the Sun, permeating the entire solar system. The consequences of the enhanced radiation and particle fluxes from the young Sun were potentially severe for the evolution of solar-system planets and moons. Interactions of high-energy radiation and the solar wind with upper planetary atmospheres may have led to the escape of important amounts of atmospheric constituents. The present dry atmosphere of Venus and the thin atmosphere of Mars may be a product of early irradiation and heating by solar high-energy radiation. High levels of magnetic activity are also inferred for the pre-main sequence Sun. At those stages, interactions of high-energy radiation and particles with the circumsolar disk in which planets eventually formed were important. Traces left in meteorites by energetic particles and anomalous isotopic abundance ratios in meteoritic inclusions may provide evidence for a highly active pre-main sequence Sun. The present article reviews these various issues related to the magnetic activity of the young Sun and the consequent interactions with its environment. The emphasis is on the phenomenology related to the production of high-energy photons and particles. Apart from the activity on the young Sun, systematic trends applicable to the entire

  13. Sun为eCommerce提供高可用性平台--记电子商务外包资源领先提供商Digital River对Sun平台的选用%Provision of Highly Applicable Platform by Sun for E-Commerce:Selection of Sun Platform by Digital River, the Leading Supplier of E-Commerce Resources

    Institute of Scientific and Technical Information of China (English)

    SUN公司北京分公司

    2004-01-01

    @@ Digital River公司是全球领先的电子商务外包资源提供商,在Sun StorEdge 9960磁盘阵列、Sun Fire 6800服务器,以及Sun 420R/280R架装式服务器等系统的采用,成功地提高了网络系统的性能,并扩展了客户服务项目.

  14. Why the sun sucks - Architects versus the sun

    NARCIS (Netherlands)

    De Lange, N.; Niesten, J.; Taminiau, P.

    2014-01-01

    This "designers' manual" is made during the TIDO-course AR0531 Innovation and Sustainability This manual will show how not to design with the Sun. By showing examples how buildings have failed that have not taken the Sun and its effects in consideration, one should get a clearer picture of how you

  15. Why the sun sucks - Architects versus the sun

    NARCIS (Netherlands)

    De Lange, N.; Niesten, J.; Taminiau, P.

    2014-01-01

    This "designers' manual" is made during the TIDO-course AR0531 Innovation and Sustainability This manual will show how not to design with the Sun. By showing examples how buildings have failed that have not taken the Sun and its effects in consideration, one should get a clearer picture of how you

  16. Development and application of the portable full autocontrol sun-photometer%便携式全自动太阳光度计的研制及其应用

    Institute of Scientific and Technical Information of China (English)

    李建玉; 徐文清; 伽丽丽; 詹杰; 高亦桥; 魏合理

    2012-01-01

    研制了一种基于VB平台可实时测量监控的可视化多波长便携式全自动太阳光度计DTF-6,可实现瞬时太阳辐照度、整层大气气溶胶光学厚度和可降水量的实时测量与显示,具有电机运转、太阳跟踪、加热温度等强大的在线检测功能.该仪器是在自行研制的第三第四代太阳光度计的基础上进行的改进,仪器更方便使用、更适应恶劣环境、更小型化和具有更高的性能价格比.通过对实测结果的分析和比较,该仪器令人满意,并给出仪器标定结果,同时对其应用进行了阐述.%A set of portable autocontrol muti-wavalength sun-photometer base on Visual Basic, which is real-time and obvious, is developed. It can measure and display instantaneous solar radiation and atmospheric aerosol optical thickness and precipitable water as well. It is also provided with the on-line detection function of electric engine operation, sun tracing , heating temperature et al. This instrument is improved based on the prototype developed by ourselves. The sun-photometer is more portable and can more accommodate to the abominable environment, more miniaturize and improve the ratio of his performance and price. The measured results of this device are satisfactory via the analysis and compare of measured data Also the instrument calibration and its application are described.

  17. Methods on Efficiently Relating Data from the Sun to In-situ Data at L1: An Application to the Slow Solar Wind

    Science.gov (United States)

    McQuillan, Maria; Viall, Nicholeen

    2017-01-01

    Understanding space weather has become increasingly important as scientists and spacecraft extend their reach further into the universe. The solar wind is highly ionized plasma that constantly bombards the earth. It causes compression and relaxation in our magnetosphere, and affects spacecraft and astronauts in outer space. There are two types of solar wind, fast wind and slow wind. The fast wind is considered to be steady in composition and speed, and travels at speeds greater than 500 km/s. The slow solar wind is known for being highly variable in composition and speed, and travels at speeds less than 500 km/s. Fast solar wind originates from coronal hole regions on the sun, while the slow solar wind’s origin is very controversial. There are currently two types of theories for slow solar wind. One theory involves wave heating dynamics, while the other contends that slow solar wind originates from magnetic reconnection that continually opens magnetic field lines. These models are currently under-constrained with both types able to reproduce the long-term, average behavior of the wind. To further constrain these models it was necessary to research small scale structure in the solar wind, however analyzing these structures pushes the limits of the current instrument capabilities. We developed techniques that provide an automated process to quickly generate results from multiple different analysis techniques, allowing the user to compare data from STEREO’s Heliospheric Imager (HI) and from data taken at L1. This increases the efficiency and ability to relate data from the sun in HI and data at Earth at L1. These techniques were applied to a study on the slow solar wind which lead to possible evidence for the S-Web model.

  18. Smart, passive sun facing surfaces

    Science.gov (United States)

    Hively, Lee M.

    1996-01-01

    An article adapted for selectively utilizing solar radiation comprises an absorptive surface and a reflective surface, the absorptive surface and the reflective surface oriented to absorb solar radiation when the sun is in a relatively low position, and to reflect solar radiation when the sun is in a relatively high position.

  19. Global Seismology of the Sun

    CERN Document Server

    Basu, Sarbani

    2016-01-01

    The seismic study of the Sun and other stars offers a unique window into the interior of these stars. Thanks to helioseismology, we know the structure of the Sun to admirable precision. In fact, our knowledge is good enough to use the Sun as a laboratory. We have also been able to study the dynamics of the Sun in great detail. Helioseismic data also allow us to probe the changes that take place in the Sun as solar activity waxes and wanes. The seismic study of stars other than the Sun is a fairly new endeavour, but we are making great strides in this field. In this review I discuss some of the techniques used in helioseismic analyses and the results obtained using those techniques. In this review I focus on results obtained with global helioseismology, i.e., the study of the Sun using its normal modes of oscillation. I also briefly touch upon asteroseismology, the seismic study of stars other than the Sun, and discuss how seismic data of others stars are interpreted.

  20. Reconnection on the Sun

    Science.gov (United States)

    Kohler, Susanna

    2016-05-01

    Because the Sun is so close, it makes an excellent laboratory to study processes we cant examinein distant stars. One openquestion is that of how solar magnetic fields rearrange themselves, producing the tremendous releases of energy we observe as solar flares and coronal mass ejections (CMEs).What is Magnetic Reconnection?Magnetic reconnection occurs when a magnetic field rearranges itself to move to a lower-energy state. As field lines of opposite polarity reconnect, magnetic energy is suddenly converted into thermal and kinetic energy.This processis believed to be behind the sudden releases of energy from the solar surface in the form of solar flares and CMEs. But there are many different models for how magnetic reconnection could occur in the magnetic field at the Suns surface, and we arent sure which one of these reconnection types is responsible for the events we see.Recently, however, several studies have been published presenting some of the first observational support of specific reconnection models. Taken together, these observations suggest that there are likely several different types of reconnection happening on the solar surface. Heres a closer look at two of these recent publications:A pre-eruption SDO image of a flaring region (b) looks remarkably similar to a 3D cartoon for typical breakout configuration (a). Click for a closer look! [Adapted from Chen et al. 2016]Study 1:Magnetic BreakoutLed by Yao Chen (Shandong University in China), a team of scientists has presented observations made by the Solar Dynamics Observatory (SDO) of a flare and CME event that appears to have been caused by magnetic breakout.In the magnetic breakout model, a series of loops in the Suns lower corona are confined by a surrounding larger loop structure called an arcade higher in the corona. As the lower loops push upward, reconnection occurs in the upper corona, removing the overlying, confining arcade. Without that extra confinement, the lower coronal loops expand upward

  1. The development of the Heliometer of the Observatorio Nacional of Rio de Janeiro and application to the study of the Sun-Earth system

    CERN Document Server

    Neto, Eugênio Reis

    2013-01-01

    This work presents the development and construction of the Heliometer of the Observat\\'orio Nacional/MCTI. This instrument is designed to monitor changes on the solar diameter with the accuracy of the next-generation solar satellites. A review of the heliometric method is made and the building and testing of 4 prototypes is described. The instrument has a mirror objective split in dihedral, formed by the hemi-sections of a parabolic mirror. The materials that form the instrument have thermal and mechanical stability to 10^(-7). The number of optical parts is minimized and their quality is greater than {\\lambda}/12. An original software for the automated collection and analysis of the images was developed. With its latest version fully developed, we conducted an observational campaign of 9 days, deriving more than 70000 heliometric images of the Sun. The measured solar diameter has a standard deviation of 0.5 arcseconds, with no instrumental bias, and limited only by the provisional atmospheric modeling. There...

  2. CU AMAX-DOAS applications in cloud-free and cloudy atmospheres: innovative Scattered Sun Light observations of trace gases and aerosol extinction

    Science.gov (United States)

    Volkamer, R.; Baidar, S.; Coburn, S.; Dix, B. K.; Oetjen, H.; Ortega, I.; Sinreich, R.; Atmospeclab

    2011-12-01

    An innovative airborne scanning multi-axis differential optical absorption spectroscopy (CU AMAX-DOAS) instrument has been developed at the University of Colorado, Boulder. The instrument collects scattered sunlight spectra in a sequence of discrete viewing angles, and employs the DOAS method (inherently calibrated, and selective) to simultaneously retrieve multiple trace gases, e.g., nitrogen dioxide (NO2), nitrous acid (HONO), formaldehyde (HCHO), glyoxal (CHOCHO), bromine oxide (BrO), iodine oxide (IO), chlorine dioxide (OClO), water vapor (H2O), and oxygen dimers (O4, at 360nm, 477nm, and 632nm) differential slant column densities (dSCD). Vertical profiles of these gases and multi-spectral aerosol extinction are inferred by combining Monte-Carlo Radiative Transfer Modelling (RTM) and optimal estimation techniques to construct a model atmosphere that can in principle represent 3D clouds and aerosols. The atmospheric state of this model atmosphere is constrained by observations of O4 dSCDs, Raman Scattering Probability (RSP), and intensity ratios, i.e., quantities that depend solely on relative intensity changes, without need for a direct sun view, or absolute radiance calibration. We show results from ongoing validation efforts (NOAA TwinOtter aircraft during CalNex and CARES), and demonstrate vertical profile retrievals (NSF/NCAR GV over the tropical Pacific Ocean) in both cloud-free and cloudy atmospheres.

  3. Totality eclipses of the Sun

    CERN Document Server

    Littmann, Mark; Willcox, Ken

    2008-01-01

    A total eclipse of the Sun is the most awesome sight in the heavens. Totality: Eclipses of the Sun takes you to eclipses of the past, present, and future, and lets you see - and feel - why people travel to the ends of the Earth to observe them. - ;A total eclipse of the Sun is the most awesome sight in the heavens. Totality: Eclipses of the Sun takes you to eclipses of the past, present, and future, and lets you see - and feel - why people travel to the ends of the Earth to observe them. Totality: Eclipses of the Sun is the best guide and reference book on solar eclipses ever written. It explains: how to observe them; how to photograph and videotape them; why they occur; their history and mythology; and future eclipses - when and where to see them. Totality also tells the remarkable story of how eclipses shocked scientists, revealed the workings of the Sun, and made Einstein famous. And the book shares the experiences and advice of many veteran eclipse observers. Totality: Eclipses of the Sun is profusely ill...

  4. Sun, UV Radiation and Your Eyes

    Science.gov (United States)

    ... Patient Stories Español Eye Health / Tips & Prevention Your Eyes and the Sun Sections The Sun, UV Radiation ... Safety Infographic The Sun, UV Radiation and Your Eyes Written by: David Turbert Aug. 28, 2014 Keep ...

  5. Clustering of Sun Exposure Measurements

    DEFF Research Database (Denmark)

    Have, Anna Szynkowiak; Larsen, Jan; Hansen, Lars Kai

    2002-01-01

    In a medically motivated Sun-exposure study, questionnaires concerning Sun-habits were collected from a number of subjects together with UV radiation measurements. This paper focuses on identifying clusters in the heterogeneous set of data for the purpose of understanding possible relations between...... Sun-habits exposure and eventually assessing the risk of skin cancer. A general probabilistic framework originally developed for text and Web mining is demonstrated to be useful for clustering of behavioral data. The framework combines principal component subspace projection with probabilistic...

  6. Sun position calculator (SPC) for Landsat imagery with geodetic latitudes

    Science.gov (United States)

    Seong, Jeong C.

    2015-12-01

    Landsat imagery comes with sun position information such as azimuth and sun elevation, but they are available only at the center of a scene. To aid in the use of Landsat imagery for various solar radiation applications such as topographic correction, solar power, urban heat island, agriculture, climate and vegetation, it is necessary to calculate the sun position information at every pixel. This research developed a PC application that creates sun position data layers in ArcGIS at every pixel in a Landsat scene. The SPC program is composed of two major routines - converting universal transverse Mercator (UTM) projection coordinates to geographic longitudes and latitudes, and calculating sun position information based on the Meeus' routine. For the latter, an innovative method was also implemented to account for the Earth's flattening on an ellipsoid. The Meeus routine implemented in this research showed about 0.2‧ of mean absolute difference from the National Renewable Energy Laboratory (NREL) Solar Position Algorithm (SPA) routine when solar zenith and azimuth angles were tested with every 30 min data at four city locations (Fairbanks, Atlanta, Sydney and Rio Grande) on June 30, 2014. The Meeus routine was about ten times faster than the SPA routine. Professionals who need the Sun's position information for Landsat imagery will benefit from the SPC application.

  7. NEW SUNS IN THE COSMOS?

    Energy Technology Data Exchange (ETDEWEB)

    De Freitas, D. B.; Leao, I. C.; Lopes, C. E. Ferreira; Paz-Chinchon, F.; Canto Martins, B. L.; Alves, S.; De Medeiros, J. R. [Departamento de Fisica, Universidade Federal do Rio Grande do Norte, 59072-970 Natal, RN (Brazil); Catelan, M. [Departamento de Astronomia y Astrofisica, Pontificia Universidad Catolica de Chile, Av. Vicuna Mackenna 4860, 782-0436 Macul, Santiago (Chile)

    2013-08-20

    The present work reports on the discovery of three stars that we have identified to be rotating Sun-like stars, based on rotational modulation signatures inferred from light curves from the CoRoT mission's Public Archives. In our analysis, we performed an initial selection based on the rotation period and position in the period-T{sub eff} diagram. This revealed that the stars CoRoT IDs 100746852, 102709980, and 105693572 provide potentially good matches to the Sun with a similar rotation period. To refine our analysis, we applied a novel procedure, taking into account the fluctuations of the features associated with photometric modulation at different time intervals and the fractality traces that are present in the light curves of the Sun and of these ''New Sun'' candidates alike. In this sense, we computed the so-called Hurst exponent for the referred stars, for a sample of 14 CoRoT stars with sub- and super-solar rotational periods, and for the Sun itself in its active and quiet phases. We found that the Hurst exponent can provide a strong discriminant of Sun-like behavior, going beyond what can be achieved with solely the rotation period itself. In particular, we find that CoRoT ID 105693572 is the star that most closely matches the solar rotation properties as far as the latter's imprints on light curve behavior are concerned. The stars CoRoT IDs 100746852 and 102709980 have significant smaller Hurst exponents than the Sun, notwithstanding their similarity in rotation periods.

  8. Thermal evaluation of a sun tracking solar cooker

    Directory of Open Access Journals (Sweden)

    Yousif El-Tous, Omar. O. Badran, Anwar Al-Mofleh

    2012-01-01

    Full Text Available Solar energy is one of many important types of renewable energy. Jordan is of great needs for renewable energy systems applications since it depends totally in generation of its required energy on imported oil. This study is an experimental work of tracking system developed for enhancing the solar heating using solar cooker. An electronic sun tracking device was used for rotating the solar heater with the movement of the sun. A comparison between fixed and sun tracked cooker showed that the use of sun tracking increased the heating temperature by 36% due to the increase in radiation concentration and using internal mirror reflectors. The programming method used for tracking control works efficiently in all weather conditions regardless of the presence of clouds. It can be used as backup control circuit in which relays are the essential control devices.

  9. SunShot Initiative Portfolio Book 2014

    Energy Technology Data Exchange (ETDEWEB)

    Solar Energy Technologies Office

    2014-05-01

    The 2014 SunShot Initiative Portfolio Book outlines the progress towards the goals outlined in the SunShot Vision Study. Contents include overviews of each of SunShot’s five subprogram areas, as well as a description of every active project in the SunShot’s project portfolio as of May 2014.

  10. From 1 Sun to 10 Suns c-Si Cells by Optimizing Metal Grid, Metal Resistance, and Junction Depth

    Directory of Open Access Journals (Sweden)

    Vikrant A. Chaudhari

    2009-01-01

    Full Text Available Use of a solar cell in concentrator PV technology requires reduction in its series resistance in order to minimize the resistive power losses. The present paper discusses a methodology of reducing the series resistance of a commercial c-Si solar cell for concentrator applications, in the range of 2 to 10 suns. Step by step optimization of commercial cell in terms of grid geometry, junction depth, and electroplating of the front metal contacts is proposed. A model of resistance network of solar cell is developed and used for the optimization. Efficiency of unoptimized commercial cell at 10 suns drops by 30% of its 1 sun value corresponding to resistive power loss of about 42%. The optimized cell with grid optimization, junction optimization, electroplating, and junction optimized with electroplated contacts cell gives resistive power loss of 20%, 16%, 11%, and 8%, respectively. An efficiency gain of 3% at 10 suns for fully optimized cell is estimated.

  11. Earth's Heat Source - The Sun

    CERN Document Server

    Manuel, Oliver K

    2009-01-01

    The Sun encompasses planet Earth, supplies the heat that warms it, and even shakes it. The United Nation Intergovernmental Panel on Climate Change (IPCC) assumed that solar influence on our climate is limited to changes in solar irradiance and adopted the consensus opinion of a Hydrogen-filled Sun, the Standard Solar Model (SSM). They did not consider the alternative solar model and instead adopted another consensus opinion: Anthropogenic greenhouse gases play a dominant role in climate change. The SSM fails to explain the solar wind, solar cycles, and the empirical link of solar surface activity with Earth changing climate. The alternative solar model, that was molded from an embarrassingly large number of unexpected observations revealed by space-age measurements since 1959, explains not only these puzzles but also how closely linked interactions between the Sun and its planets and other celestial bodies induce turbulent cycles of secondary solar characteristics that significantly affect Earth climate.

  12. The Sun: Our Nearest Star

    Science.gov (United States)

    Adams, M. L.; Six, N. Frank (Technical Monitor)

    2002-01-01

    We have in our celestial backyard, a prime example of a variable star. The Sun, long thought to be "perfect" and unvarying, began to reveal its cycles in the early 1600s as Galileo Galilei and Christoph Scheiner used a telescope to study sunspots. For the past four hundred years, scientists have accumulated data, showing a magnetic cycle that repeats, on average, every eleven (or twenty-two) years. In addition, modern satellites have shown that the energy output at radio and x-ray wavelengths also varies with this cycle. This talk will showcase the Sun as a star and discuss how solar studies may be used to understand other stars.

  13. Day the sun went out

    CERN Multimedia

    2007-01-01

    "A new british sci-fi movie envisages the death of the sun not in billions of years, but in decades. And, amazingly, the film's scientific adviser says this may not be so far from the truth..." (1/2 page)

  14. Effects of Early Sun Exposure

    Science.gov (United States)

    ... can be harmful. It can lead to:Skin changes. Some skin cells with melanin can form a clump. This creates freckles and moles. Over time, these can develop cancer.Early aging. Time spent in the sun makes your skin age faster than normal. Signs of this are wrinkled, tight, or leathery ...

  15. Tracking Planets around the Sun

    Science.gov (United States)

    Riddle, Bob

    2008-01-01

    In earlier columns, the celestial coordinate system of hour circles of right ascension and degrees of declination was introduced along with the use of an equatorial star chart (see SFA Star Charts in Resources). This system shows the planets' motion relative to the ecliptic, the apparent path the Sun follows during the year. An alternate system,…

  16. How Bright Is the Sun?

    Science.gov (United States)

    Berr, Stephen

    1991-01-01

    Presents a sequence of activities designed to allow eighth grade students to deal with one of the fundamental relationships that govern energy distribution. Activities guide students to measure light bulb brightness, discover the inverse square law, compare light bulb light to candle light, and measure sun brightness. (two references) (MCO)

  17. Tracking Planets around the Sun

    Science.gov (United States)

    Riddle, Bob

    2008-01-01

    In earlier columns, the celestial coordinate system of hour circles of right ascension and degrees of declination was introduced along with the use of an equatorial star chart (see SFA Star Charts in Resources). This system shows the planets' motion relative to the ecliptic, the apparent path the Sun follows during the year. An alternate system,…

  18. 太阳能集热技术在褐煤干燥工艺上应用的研究%Application and Study on Heat Collection Technology from Sun Energy in Lignite Drying Process

    Institute of Scientific and Technical Information of China (English)

    崔意华; 杨会民

    2013-01-01

    简述了褐煤应用技术的现状;借助Aspen plus软件模拟了褐煤干燥脱水工艺;提出了将太阳能集热技术与褐煤干燥技术耦合的技术思想和工艺流程。研究结果表明,该耦合技术具有节能降耗、环境友好、可就地生产的特点。%Author has briefly described the present situation of lignite application technology; has simulated the dry/dewater process of lignite by means of Aspen plus software; has supposed the technical idea taking the heat collection technology of sun energy coupled with the lignite dry technology and the process flow.Research result indicates that this coupling technology has the features of saving energy and reducing consume , friendly environ-ment, local production.

  19. The Sun Radio Imaging Space Experiment (SunRISE) Mission

    Science.gov (United States)

    Lazio, Joseph; Kasper, Justin; Maksimovic, Milan; Alibay, Farah; Amiri, Nikta; Bastian, Tim; Cohen, Christina; Landi, Enrico; Manchester, Ward; Reinard, Alysha; Schwadron, Nathan; Cecconi, Baptiste; Hallinan, Gregg; Hegedus, Alex; Krupar, Vratislav; Zaslavsky, Arnaud

    2017-04-01

    Radio emission from coronal mass ejections (CMEs) is a direct tracer of particle acceleration in the inner heliosphere and potential magnetic connections from the lower solar corona to the larger heliosphere. Energized electrons excite Langmuir waves, which then convert into intense radio emission at the local plasma frequency, with the most intense acceleration thought to occur within 20 RS. The radio emission from CMEs is quite strong such that only a relatively small number of antennas is required to detect and map it, but many aspects of this particle acceleration and transport remain poorly constrained. Ground-based arrays would be quite capable of tracking the radio emission associated with CMEs, but absorption by the Earth's ionosphere limits the frequency coverage of ground-based arrays (ν ≳ 15 MHz), which in turn limits the range of solar distances over which they can track the radio emission (≲ 3RS). The state-of-the-art for tracking such emission from space is defined by single antennas (Wind/WAVES, Stereo/SWAVES), in which the tracking is accomplished by assuming a frequency-to-density mapping; there has been some success in triangulating the emission between the spacecraft, but considerable uncertainties remain. We describe the Sun Radio Imaging Space Experiment (SunRISE) mission concept: A constellation of small spacecraft in a geostationary graveyard orbit designed to localize and track radio emissions in the inner heliosphere. Each spacecraft would carry a receiving system for observations below 25 MHz, and SunRISE would produce the first images of CMEs more than a few solar radii from the Sun. Part of this research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.

  20. Tanel Padar & The Sun veab õhukitarri

    Index Scriptorium Estoniae

    2008-01-01

    Õhukitarri Eesti meistrivõistlustest 19. apr. Tallinnas Rock Cafés (võistluste eestvedajaks on ansambel Tanel Padar & The Sun, kes samas esitleb oma esimest ingliskeelset albumit "Here Comes The Sun")

  1. Tanel Padar & The Sun veab õhukitarri

    Index Scriptorium Estoniae

    2008-01-01

    Õhukitarri Eesti meistrivõistlustest 19. apr. Tallinnas Rock Cafés (võistluste eestvedajaks on ansambel Tanel Padar & The Sun, kes samas esitleb oma esimest ingliskeelset albumit "Here Comes The Sun")

  2. Caddo Sun Accounts across Time and Place

    Science.gov (United States)

    Gerona, Carla

    2012-01-01

    Billy Day, a Tunica/Biloxi, recently described the significance of the sun for Caddoan people. Day quoted an "old Caddo relative" of his who said: "I used to go outside and hold my hands up and bless myself with the sun--'a'hat.' Well, I can't do that anymore because they say we are sun worshipers. We didn't worship the sun. We worshiped what was…

  3. Global Warming Blame the Sun

    CERN Document Server

    Calder, N

    1997-01-01

    Concern about climate change reaches a political peak at a UN conference in Kyoto, 1-10 December, but behind the scenes the science is in turmoil. A challenge to the hypothesis that greenhouse gases are responsible for global warming comes from the discovery that cosmic rays from the Galaxy are involved in making clouds (Svensmark and Friis-Christensen, 1997). During the 20th Century the wind from the Sun has grown stronger and the count of cosmic rays has diminished. With fewer clouds, the EarthÕs surface has warmed up. This surprising mechanism explains the link between the Sun and climate change that astronomers and geophysicists have suspected for 200 years.

  4. Total eclipses of the sun.

    Science.gov (United States)

    Zirker, J B

    1980-12-19

    Total eclipses of the sun offer research opportunities in a variety of sciences. Some of the advances in solar physics resulting from eclipse observations are discussed. Experiments at the total eclipse of 16 February 1980 in India are also described. These included a test of general relativity, studies in coronal physics, investigations of solar prominences, diameter measurements, a search for interplanetary dust, a study of the gravity waves in the earth's atmosphere, and experiments on the biological effects on animals and humans.

  5. Revisiting SU(N) integrals

    CERN Document Server

    Zuber, Jean-Bernard

    2016-01-01

    In this note, I revisit integrals over $\\SU(N)$ of the form $ \\int DU\\, U_{i_1j_1}\\cdots U_{i_pj_p}\\Ud_{k_1l_1}\\cdots \\Ud_{k_nl_n}$. While the case $p=n$ is well known, it seems that explicit expressions for $p=n+N$ had not appeared in the literature. Similarities and differences, in particular in the large $N$ limit, between the two cases are discussed

  6. Coherent States with SU(N) Charges

    CERN Document Server

    Mathur, M; Mathur, Manu; Paul, Samir K.

    2003-01-01

    We define coherent states carrying SU(N) charges by exploiting generalized Schwinger boson representation of SU(N) Lie algebra. These coherent states are defined on $2 (2^{N - 1} - 1)$ complex planes. They satisfy continuity property and provide resolution of identity. We also exploit this technique to construct the corresponding non-linear SU(N) coherent states.

  7. The Sun Rises on the Solar Sector

    OpenAIRE

    Ahmad, Reyaz A.

    2009-01-01

    Energy from the sun is abundant and free. Solar energy is in essence electromagnetic radiation emitted from the sun. Earth's climate, hydrologic systems, and ecosystems all derive from the sun. Other forms of renewable power such as wind, wave, biomass, and hydro are an indirect function of solar radiation.

  8. The Sun A User's Manual

    CERN Document Server

    Vita-Finzi, Claudio

    2008-01-01

    The Sun is an account of the many ways in which our nearest star affects our planet, how its influence has changed over the last few centuries and millennia, and the extent to which we can predict its future impact. The Sun's rays foster the formation of Vitamin D by our bodies, but it can also promote skin cancer, cataracts, and mutations in our DNA. Besides providing the warmth and light essential to most animal and plant life, solar energy contributes substantially to global warming. Although the charged particles of the solar wind shield us from harmful cosmic rays, solar storms may damage artificial satellites and cripple communication systems and computer networks. The Sun is the ideal renewable energy source, but its exploitation is still bedevilled by the problems of storage and distribution. Our nearest star, in short, is a complex machine which needs to be treated with caution, and this book will equip every reader with the knowledge that is required to understand the benefits and dangers it can bri...

  9. The faint young Sun problem

    CERN Document Server

    Feulner, Georg

    2012-01-01

    For more than four decades, scientists have been trying to find an answer to one of the most fundamental questions in paleoclimatology, the `faint young Sun problem'. For the early Earth, models of stellar evolution predict a solar energy input to the climate system which is about 25% lower than today. This would result in a completely frozen world over the first two billion years in the history of our planet, if all other parameters controlling Earth's climate had been the same. Yet there is ample evidence for the presence of liquid surface water and even life in the Archean (3.8 to 2.5 billion years before present), so some effect (or effects) must have been compensating for the faint young Sun. A wide range of possible solutions have been suggested and explored during the last four decades, with most studies focusing on higher concentrations of atmospheric greenhouse gases like carbon dioxide, methane or ammonia. All of these solutions present considerable difficulties, however, so the faint young Sun prob...

  10. Sun Savvy Students: Free Teaching Resources from EPA's SunWise Program

    Science.gov (United States)

    Hall-Jordan, Luke

    2008-01-01

    With summer in full swing and the sun is naturally on our minds, what better time to take advantage of a host of free materials provided by the U.S. Environmental Protection Agency's Sun Wise program. Sun Wise aims to teach students and teachers about the stratospheric ozone layer, ultraviolet (UV) radiation, and how to be safe while in the Sun.…

  11. A low-power and high-precision miniaturized digital sun sensor

    NARCIS (Netherlands)

    Boer, B.M. de; Durkut, M.

    2013-01-01

    A prototype miniaturized digital sun sensor (miniDSS) was developed by TNO. It is expected to be launched on QuadSat for in-orbit demonstration. The single-chip sun sensor comprises an application specific integrated circuit (ASIC) on which an active pixel sensor (APS), read-out and processing circu

  12. Micro technology based sun sensor

    DEFF Research Database (Denmark)

    Hales, Jan Harry; Pedersen, Martin; Fléron, René

    2003-01-01

    There is increasing interest among universities in the scientific and educational possibilities of picosatellites base on the CubeSat 5 concept. Due to sever mass and dimension constraints place on this type of satellites, new approaches and ideas regarding different systems arises to accommodate...... DTUsat sun sensors are needed along with a magnetometer to obtain unambiguous attitude determination for the ACDS and the payloads - an electrodynamic tether and a camera. The accuracy needed was not obtainable by employing conventional attitude sensors. Hence a linear slit sensor was designed...

  13. Solar flare leaves sun quaking

    Science.gov (United States)

    1998-05-01

    Dr. Alexander G. Kosovichev, a senior research scientist from Stanford University, and Dr. Valentina V. Zharkova from Glasgow (United Kingdom) University found the tell-tale seismic signature in data on the Sun's surface collected by the Michelson Doppler Imager onboard the Solar and Heliospheric Observatory (SOHO) spacecraft immediately following a moderate-sized flare on July 9, 1996. "Although the flare was a moderate one, it still released an immense amount of energy," said Dr. Craig Deforest, a researcher with the SOHO project. "The energy released is equal to completely covering the Earth's continents with a yard of dynamite and detonating it all at once." SOHO is a joint project of the European Space Agency and NASA. The finding is reported in the May 28 issue of the journal Nature, and is the subject of a press conference at the spring meeting of the American Geophysical Union in Boston, Mass., May 27. The solar quake that the science team recorded looks much like ripples spreading from a rock dropped into a pool of water. But over the course of an hour, the solar waves traveled for a distance equal to 10 Earth diameters before fading into the fiery background of the Sun's photosphere. Unlike water ripples that travel outward at a constant velocity, the solar waves accelerated from an initial speed of 22,000 miles per hour to a maximum of 250,000 miles per hour before disappearing. "People have looked for evidence of seismic waves from flares before, but they didn't have a theory so they didn't know where to look," says Kosovichev. Several years ago Kosovichev and Zharkova developed a theory that can explain how a flare, which explodes in space above the Sun's surface, can generate a major seismic wave in the Sun's interior. According to the currently accepted model of solar flares, the primary explosion creates high-energy electrons (electrically charged subatomic particles). These are funneled down into a magnetic flux tube, an invisible tube of magnetic

  14. Seismology of the Wounded Sun

    CERN Document Server

    Cally, Paul S

    2013-01-01

    Active regions are open wounds in the Sun's surface. Seismic oscillations from the interior pass through them into the atmosphere, changing their nature in the process to fast and slow magneto-acoustic waves. The fast waves then partially reflect and partially mode convert to upgoing and downgoing Alfv\\'en waves. The reflected fast and downgoing Alfv\\'en waves then re-enter the interior through the active regions that spawned them, infecting the surface seismology with signatures of the atmosphere. Using numerical simulations of waves in uniform magnetic fields, we calculate the upward acoustic and Alfv\\'enic losses in the atmosphere as functions of field inclination and wave orientation as well as the Time-Distance `travel time' perturbations, and show that they are related. Travel time perturbations relative to quiet Sun can exceed 40 seconds in 1 kG magnetic field. It is concluded that active region seismology is indeed significantly infected by waves leaving and re-entering the interior through magnetic w...

  15. The Sun's New Exotic Neighbour

    Science.gov (United States)

    2006-03-01

    Using ESO's Very Large Telescope in Chile, an international team of researchers [1] discovered a brown dwarf belonging to the 24th closest stellar system to the Sun. Brown dwarfs are intermediate objects that are neither stars nor planets. This object is the third closest brown dwarf to the Earth yet discovered, and one of the coolest, having a temperature of about 750 degrees Celsius. It orbits a very small star at about 4.5 times the mean distance between the Earth and the Sun. Its mass is estimated to be somewhere between 9 and 65 times the mass of Jupiter. At a time when astronomers are peering into the most distant Universe, looking at objects as far as 13 billion light-years away, one may think that our close neighbourhood would be very well known. Not so. Astronomers still find new star-like objects in our immediate vicinity. Using ESO's VLT, they just discovered a brown dwarf companion to the red star SCR 1845-6357, the 36th closest star to the Sun. ESO PR Photo 11/06 ESO PR Photo 11a/06 New Brown Dwarf in the Solar Neighbourhood (Artist's Impression) "This newly found brown dwarf is a valuable object because its distance is well known, allowing us to determine with precision its intrinsic brightness", said team member Markus Kasper (ESO). "Moreover, from its orbital motion, we should be able in a few years to estimate its mass. These properties are vital for understanding the nature of brown dwarfs." To discover this brown dwarf, the team used the high-contrast adaptive optics NACO Simultaneous Differential Imager (SDI [2]) on ESO's Very Large Telescope, an instrument specifically developed to search for extrasolar planets. The SDI camera enhances the ability of the VLT and its adaptive optics system to detect faint companions that would normally be lost in the glare of the primary star. In particular, the SDI camera provides additional, often very useful spectral information which can be used to determine a rough temperature for the object without follow

  16. TRIGONOMETRIC SU(N) GAUDIN MODEL

    Institute of Scientific and Technical Information of China (English)

    曹俊鹏; 侯伯宇; 岳瑞宏

    2001-01-01

    In this paper, we obtain the eigenstates and the eigenvalues of the Hamiltonians of the trigonometric SU(N) Gaudin model based on the quasi-classical limit of the trigonometric SU(N) chain with the periodic boundary condition.By using the quantum inverse scattering method, we also obtain the eigenvalues of the generating function of the trigonometric SU(N) Gaudin model.

  17. The summer sun shone round me

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The summer sun shone round me, The folded valley lay In a stream of sun and odour, That sultry summer day. The tall trees stood in the sunlight As still as still could be, But the deep grass sighed and rustled And bowed and beckoned me. The deep grass moved and whispered And bowed and brushed my face. It whis pered in the sunshine: The winter comes apdce.”The summer sun shone round me

  18. Sun awareness in Maltese secondary school students.

    Science.gov (United States)

    Aquilina, S; Gauci, A Amato; Ellul, M; Scerri, L

    2004-11-01

    Studies indicate that reducing exposure to ultraviolet light during childhood and adolescence decreases the risk of skin cancer. From a young age, children need to be educated about the sun's harmful effects on the skin and how best to protect themselves. To help in the design of school-based interventions to raise sun awareness, a school survey was carried out to identify students' stereotypes and misconceptions. A total of 965 students attending Maltese secondary schools in forms 1, 2 and 3 were surveyed in May 2002, using a structured questionnaire designed to examine students' sun-related attitudes and knowledge. A high level of sun awareness among students was demonstrated, with high scores on knowledge of the effects of the sun on the skin, knowledge of skin cancer and knowledge of sun protection. Girls were clearly more knowledgeable than boys. However, of all the students surveyed, 55% thought that a suntan made them look better and 70% thought that their friends would desire a tan. These views were commoner among the older students. Skin type and hair or eye colour had no bearing on attitudes towards tanning or sun-related knowledge. The commonest misconceptions were that 'the sun is bad for your skin only when you get sunburnt' and that 'you cannot get too much sun on a cloudy day'. Deliberate suntanning was more frequently reported by girls than by boys and by students in the higher forms. Attitude change lags behind knowledge. Future school sun awareness interventions need to take into account gender and age differences in students' attitudes and perspectives. They should aim at motivating attitude change and preventive behaviour through consistent and repeated sun-education messages that are supported by a sun-conscious school environment.

  19. Sun Jingxia Devotes Herself to Nursing Work

    Institute of Scientific and Technical Information of China (English)

    1995-01-01

    "I really didn’t expect that at my advanced age, I would be awarded the highest honor in international nursing circles," said Mme. Sun Jingxia, 81, who had just returned from Beijing where she received the Nightingale Medal. Wearing a light yellow suit, with a collar bordered in red, Sun is inhigh spirits, reminding people of the beauty of the setting sun. It is clear that Sun Jingxia has deep feelings as she looks at the medal which shows a relief of Florence Nightingale’s head. She spoke in her usual soft voice but with some excitement, "President Jiang

  20. Real-Time Projection Shadow with Respect to Sun Position in Virtual Environments

    Directory of Open Access Journals (Sweden)

    Hoshang Kolivand

    2011-11-01

    Full Text Available This paper proposes a real-time software for outdoor rendering to control the shadows position with effect of sun's position. The position of sun plays an important rule for outdoor games. Calculation of sun's position, as a result, position and length of shadows require a lot of attention and preciseness. Julian dating is used to calculate the sun's position in the virtual dome. In addition, of computer graphics, building design is another field that this paper contributes on it. To create shadow, projection shadow is proposed. By calculating the sun's position in the specific date, time and location on the earth, shadow is generated. Length and angle of shadow are two parameters measured for building design and both of them are calculated in this real-time application. Therefore, it can be used for teachers to teach some part of physics about earth orbit and it can be used in building design and commercial games in virtual reality systems.

  1. Regina vs Hubbs: Determining the Sun's Position

    CERN Document Server

    Samra, Raminder Singh

    2012-01-01

    Here I determined the Sun's position as an expert witness for crown counsel. From my calculations I found the Sun's location in the sky was such that it could not impede the driver's vision, as a result it could not have been the reason for the accused to be involved in a motor vehicle accident.

  2. Evaluation of a sun safety education programme for primary school students in Switzerland.

    Science.gov (United States)

    Reinau, Daphne; Meier, Christoph R; Gerber, Nathalie; Surber, Christian

    2014-07-01

    The incidence of skin cancer has increased worldwide, with rates being especially high in Switzerland compared with other European countries. Extensive sun exposure during childhood is considered a key factor for skin carcinogenesis. The aim of the study was to evaluate the impact of a school-based sun safety education programme developed by the Swiss Cancer Leagues on primary school students' sun-related knowledge, protective behaviours and sunburn rates. In summer 2011, 1-h sun safety education sessions were held at 33 primary schools throughout the Canton of Zurich (North-Eastern Switzerland). Children in the participating school classes (first, second and third graders) answered a questionnaire on their sun-related knowledge, behaviours and sunburn experience shortly before and 1 year after the intervention. Overall, 3110 completed pretest and 1738 post-test questionnaires were eligible for analysis. The evaluation of pretest data showed considerable room for improvement in terms of sun-related knowledge, considering that merely a good half of the children were conscious that the sun may present a hazard to health. Overall, more than 95% of students benefited from the protection of sunscreen (application by parents: 73%; application by child: 66%), but only 36% stated that they generally sought shade on sunny days. After the intervention, knowledge increased considerably and significantly (P<0.0001), but there was no change in sun-protective behaviours (use of sunscreen, seeking shade). However, we observed a nonsignificant trend towards decreased sunburn rates. The brief one-time sun safety education sessions were effective in sustainably improving children's sun-related knowledge and possibly to some extent in decreasing their sunburn rates.

  3. Mitochondrial DNA deletion percentage in sun exposed and non sun exposed skin.

    Science.gov (United States)

    Powers, Julia M; Murphy, Gillian; Ralph, Nikki; O'Gorman, Susan M; Murphy, James E J

    2016-12-01

    The percentages of mitochondrial genomes carrying the mtDNA(3895) and the mtDNA(4977) (common) deletion were quantified in sun exposed and non sun exposed skin biopsies, for five cohorts of patients varying either in sun exposure profile, age or skin cancer status. Non-melanoma skin cancer diagnoses are rising in Ireland and worldwide [12] but most risk prediction is based on subjective visual estimations of sun exposure history. A quantitative objective test for pre-neoplastic markers may result in better adherence to sun protective behaviours. Mitochondrial DNA (mtDNA) is known to be subject to the loss of a significant proportion of specific sections of genetic code due to exposure to ultraviolet light in sunlight. Although one such deletion has been deemed more sensitive, another, called the mtDNA(4977) or common deletion, has proved to be a more useful indicator of possible risk in this study. Quantitative molecular analysis was carried out to determine the percentage of genomes carrying the deletion using non sun exposed and sun exposed skin biopsies in cohorts of patients with high or low sun exposure profiles and two high exposure groups undergoing treatment for NMSC. Results indicate that mtDNA deletions correlate to sun exposure; in groups with high sun exposure habits a significant increase in deletion number in exposed over non sun exposed skin occurred. An increase in deletion percentage was also seen in older cohorts compared to the younger group. The mtDNA(3895) deletion was detected in small amounts in exposed skin of many patients, the mtDNA(4977) common deletion, although present to some extent in non sun exposed skin, is suggested to be the more reliable and easily detected marker. In all cohorts except the younger group with relatively lower sun exposure, the mtDNA(4977) deletion was more frequent in sun exposed skin samples compared to non-sun exposed skin.

  4. Gravitational Lensing Characteristics of the Transparent Sun

    CERN Document Server

    Patla, Bijunath

    2007-01-01

    The transparent Sun is modeled as a spherically symmetric and centrally condensed gravitational lens using recent Standard Solar Model (SSM) data. The Sun's minimum focal length is computed to a refined accuracy of 23.5 +/- 0.1 AU, just beyond the orbit of Uranus. The Sun creates a single image of a distant point source visible to observers inside this minimum focal length and to observers sufficiently removed from the line connecting the source through the Sun's center. Regions of space are mapped where three images of a distant point source are created, along with their associated magnifications. Solar caustics, critical curves, and Einstein rings are computed and discussed. Extremely high gravitational lens magnifications exist for observers situated so that an angularly small, unlensed source appears near a three-image caustic. Types of radiations that might undergo significant solar lens magnifications as they can traverse the core of the Sun, including neutrinos and gravitational radiation, are discusse...

  5. Vibration Based Sun Gear Damage Detection

    Science.gov (United States)

    Hood, Adrian; LaBerge, Kelsen; Lewicki, David; Pines, Darryll

    2013-01-01

    Seeded fault experiments were conducted on the planetary stage of an OH-58C helicopter transmission. Two vibration based methods are discussed that isolate the dynamics of the sun gear from that of the planet gears, bearings, input spiral bevel stage, and other components in and around the gearbox. Three damaged sun gears: two spalled and one cracked, serve as the focus of this current work. A non-sequential vibration separation algorithm was developed and the resulting signals analyzed. The second method uses only the time synchronously averaged data but takes advantage of the signal/source mapping required for vibration separation. Both algorithms were successful in identifying the spall damage. Sun gear damage was confirmed by the presence of sun mesh groups. The sun tooth crack condition was inconclusive.

  6. A Physical Model of Phaethon, a Near-Sun Object

    Science.gov (United States)

    Boice, Daniel C.; Benkhoff, J.; Huebner, W. F.

    2013-10-01

    Physico-chemical modeling is central to understand the important physical processes that occur in small solar system bodies. We have developed a computer code, SUSEI, that includes the physico-chemical processes relevant to comets within a global modeling framework to better understand observations and in situ measurements and to provide valuable insights into the intrinsic properties of their nuclei. SUISEI includes a 3D model of gas and heat transport in porous sub-surface layers in the interior of the nucleus. We have successfully used this model in our study of previous comets at normal heliocentric distances [e.g., 46P/Wirtanen, D/1993 F2 (Shoemaker-Levy 9)]. We have adapted SUISEI to model near-Sun objects to reveal significant differences in the chemistry and dynamics of their comae (atmosphere) with comets that don’t closely approach the Sun. At small heliocentric distances, temperatures are high enough to vaporize surface materials and dust, forming a source of gas. Another important question concerns the energy balance at the body’s surface, namely what fraction of incident energy will be conducted into the interior versus that used for sublimation. This is important to understand if the interior stays cold and is relatively unaltered during each perihelion passage or is significantly devolatilized. This also bears upon the regimes where sublimation and ablation due to ram pressure dominate in the erosion or eventual destruction of sun-grazers. The resulting model will be an important tool for studying sungrazing comets and other near-Sun objects. We will present results on the application of SUISEI to the near-Sun object, Phaethon. Acknowledgements: We appreciate support from the SwRI IR&D and the NSF Planetary Astronomy Programs.

  7. The Sun and How to Observe It

    CERN Document Server

    Jenkins, Jamey L

    2009-01-01

    Without the Sun, all life on Earth would perish. But what exactly do we know about this star that lights, heats, and powers Earth? Actually, we know quite a lot, thanks mainly to a host of eager solar observers. Looking directly at the Sun is EXTREMELY hazardous. But many astronomers, both professional and amateur, have found ways to view the Sun safely to learn about it. You, too, can view the Sun in all of its glorious detail. Some of the newest, most exciting telescopes on the market are affordable to amateur astronomers or even just curious sky watchers, and with this guide to what the Sun has to offer, including sunspots, prominences, and flares, plus reviews of the latest instruments for seeing and capturing images of the Sun, you can contribute to humankind’s knowledge of this immense ball of glowing gases that gives us all life. For a complete guide to Sun viewing, see also Total Solar Eclipses and How to Observe Them (2007) by Martin Mobberley in this same series.

  8. SunPy—Python for solar physics

    Science.gov (United States)

    SunPy Community; Mumford, Stuart J.; Christe, Steven; Pérez-Suárez, David; Ireland, Jack; Shih, Albert Y.; Inglis, Andrew R.; Liedtke, Simon; Hewett, Russell J.; Mayer, Florian; Hughitt, Keith; Freij, Nabil; Meszaros, Tomas; Bennett, Samuel M.; Malocha, Michael; Evans, John; Agrawal, Ankit; Leonard, Andrew J.; Robitaille, Thomas P.; Mampaey, Benjamin; Campos-Rozo, Jose Iván; Kirk, Michael S.

    2015-01-01

    This paper presents SunPy (version 0.5), a community-developed Python package for solar physics. Python, a free, cross-platform, general-purpose, high-level programming language, has seen widespread adoption among the scientific community, resulting in the availability of a large number of software packages, from numerical computation (NumPy, SciPy) and machine learning (scikit-learn) to visualization and plotting (matplotlib). SunPy is a data-analysis environment specializing in providing the software necessary to analyse solar and heliospheric data in Python. SunPy is open-source software (BSD licence) and has an open and transparent development workflow that anyone can contribute to. SunPy provides access to solar data through integration with the Virtual Solar Observatory (VSO), the Heliophysics Event Knowledgebase (HEK), and the HELiophysics Integrated Observatory (HELIO) webservices. It currently supports image data from major solar missions (e.g., SDO, SOHO, STEREO, and IRIS), time-series data from missions such as GOES, SDO/EVE, and PROBA2/LYRA, and radio spectra from e-Callisto and STEREO/SWAVES. We describe SunPy's functionality, provide examples of solar data analysis in SunPy, and show how Python-based solar data-analysis can leverage the many existing tools already available in Python. We discuss the future goals of the project and encourage interested users to become involved in the planning and development of SunPy.

  9. Anisotropic microstructure near the sun

    Science.gov (United States)

    Coles, W. A.; Grall, R. R.; Spangler, S. R.; Sakurai, T.; Harmon, J. K.

    1996-07-01

    Radio scattering observations provide a means of measuring a two-dimensional projection of the three-dimensional spatial spectrum of electron density, i.e., in the plane perpendicular to the line of sight. Earlier observations have shown that the microstructure at scales of the order of 10 km becomes highly field-aligned inside of 10 Rsolar [Armstrong et al., 1990]. Earlier work has also shown that density fluctuations at scales larger than 1000 km have a Kolmogorov spectrum, whereas the smaller scale structure has a flatter spectrum and is considerably enhanced above the Kolmogorov ``background'' [Coles et al., 1991]. Here we present new observations made during 1990 and 1992. These confirm the earlier work, which was restricted to one source on a few days, but they suggest that the anisotropy changes abruptly near 6 Rsolar which was not clear in the earlier data. The axial ratio measurements are shown on Figure 1 below. The new observations were made with a more uniform sampling of the spatial plane. They show that contours of constant correlation are elliptical. This is apparently inconsistent with the spatial correlation of the ISEE-3 magnetic field which shows a ``Maltese Cross'' shape [Matthaeus et al., 1990]. However this inconsistency may be only apparent: the magnetic field and density correlations need not have the same shape; the scale of the magnetic field correlations is at least 4 orders of magnitude larger; they are much further from the sun; and they are point measurements whereas ours are path-integrated. We also made two simultaneous measurements, at 10 Rsolar, of the anisotropy on scales of 200 to 4000 km. Significant anisotropy was seen on the smaller scales, but the larger scale structure was essentially isotropic. This suggests that the process responsible for the anisotropic microstructure is independent of the larger scale isotropic turbulence. It is then tempting to speculate that the damping of this anisotropic process inside of 6 Rsolar

  10. The Sun's dusty interstellar environment

    Science.gov (United States)

    Sterken, Veerle

    2016-07-01

    The Sun's dusty interstellar environment Interstellar dust from our immediate interstellar neighborhood travels through the solar system at speeds of ca. 26 km/s: the relative speed of the solar system with respect to the local interstellar cloud. On its way, its trajectories are altered by several forces like the solar radiation pressure force and Lorentz force. The latter is due to the charged dust particles that fly through the interplanetary magnetic field. These trajectories differ per particle type and size and lead to varying fluxes and directions of the flow inside of the solar system that depend on location but also on phase in the solar cycle. Hence, these fluxes and directions depend strongly on the configuration of the inner regions and outer regions of the heliosphere. Several missions have measured this dust in the solar system directly. The Ulysses dust detector data encompasses 16 years of intestellar dust fluxes and approximate directions, Stardust captured returned to Earth a few of these particles sucessfully, and finally the Cassini dust detector allowed for compositional information to be obtained from the impacts on the instrument. In this talk, we give an overview of the current status of interstellar dust research through the measurements made inside of the solar system, and we put them in perspective to the knowledge obtained from more classical astronomical means. In special, we focus on the interaction of the dust with the interplanetary magnetic field, and on what we learn about the dust (and the fields) by comparing the available dust data to computer simulations of dust trajectories. Finally, we synthesize the different methods of observation, their results, and give a preview on new research opportunities in the coming year(s).

  11. Perspectives on the Interior of the Sun

    Indian Academy of Sciences (India)

    S. Μ. Chitre

    2000-09-01

    The interior of the Sun is not directly accessible to observations. Nonetheless, it is possible to infer the physical conditions inside the Sun with the help of structure equations governing its equilibrium and with the powerful observational tools provided by the neutrino fluxes and oscillation frequencies. The helioseismic data show that the internal constitution of the Sun can be adequately represented by a standard solar model. It turns out that a cooler solar core is not a viable solution for the measured deficit of neutrino fluxes, and the resolution of the solar neutrino puzzle should be sought in the realm of particle physics.

  12. The Jovian period in the Sun?

    Science.gov (United States)

    Kotov, V. A.

    2015-09-01

    The 41-year measurements of the Doppler effect of the photosphere performed at the Crimean Astrophysical Observatory, discovered two periods of global oscillations of the Sun: 9600.606(12) s and 9597.929(15) s. Their beat period, 398.4(2.9) d, well agrees with a synodic orbital period of Jupiter, PJ = 398.9 d, raising a new problem for solar physics, cosmogony and cosmology. A hypothesis is advanced that the PJ beating of the Sun is induced by gravitation of Jupiter, revolving in a privileged reference system "the Sun - the Earth".

  13. Semiautomatic sun shots with the WIDIF DIflux

    Science.gov (United States)

    Rasson, Jean L.; Hendrickx, Olivier; Marin, Jean-Luc

    2017-07-01

    The determination of magnetic declination angle entails finding two directions: geographic north and magnetic north. This paper deals with the former. The known way to do it by using the sun's calculable orientation in the sky is improved by using a device based on a WIDIF DIflux theodolite and split photocells positioned on its telescope ocular. Given the WIDIF accurate timing and location provided by the onboard GPS receiver, an astronomical computation can be effected to accurately and quickly determine the sun's azimuth and an auxiliary mark's azimuth. The precise sun's crossing of the split photocell, amplified by the telescope's magnification, allows azimuth accuracies of a few seconds of arc.

  14. SunDial: embodied informal science education using GPS

    Directory of Open Access Journals (Sweden)

    Megan K. Halpern

    2011-06-01

    Full Text Available Science centers serve a number of goals for visitors, ideally providing experiences that are educational, social, and meaningful. This paper describes SunDial, a handheld application developed for families to use at a science center. Inspired by the idea of geocaching, the high-tech treasure hunting game that utilizes GPS technologies, SunDial asks families to use a single handheld device to locate and participate in a series of learning modules around the museum. Observations of 10 families suggest that it supports rich informal science education experiences, provides insights about families’ interaction patterns around and with single handheld devices, and demonstrates the value of navigation as an educational experience. Further, using recently released guidelines for Informal Science Education (ISE experiences to inform the design process proved valuable, tying features of the technology to educational and social goals, and giving evidence that explicit reference to these guidelines can improve ISE experiences and technologies.

  15. The impact of Sun-weather research on forecasting

    Science.gov (United States)

    Larsen, M. F.

    1979-01-01

    The possible impact of Sun-weather research on forecasting is examined. The type of knowledge of the effect is evaluated to determine if it is in a form that can be used for forecasting purposes. It is concluded that the present understanding of the effect does not lend itself readily to applications for forecast purposes. The limits of present predictive skill are examined and it is found that skill is most lacking for prediction of the smallest scales of atmospheric motion. However, it is not expected that Sun-weather research will have any significant impact on forecasting the smaller scales since predictability at these scales is limited by the finite grid size resolution and the time scales of turbulent diffusion. The predictability limits for the largest scales are on the order of several weeks although presently only a one week forecast is achievable.

  16. 76 FR 24523 - Sun & Lake Pharmacy, Inc.; D/B/A the Medicine Shoppe; Revocation of Registration

    Science.gov (United States)

    2011-05-02

    ... Enforcement Administration Sun & Lake Pharmacy, Inc.; D/B/A the Medicine Shoppe; Revocation of Registration On... Administration, issued an Order to Show Cause to Sun & Lake Pharmacy, Inc., d/b/a The Medicine Shoppe... Certificate of Registration, BS9433828, as a retail pharmacy, and the denial of any pending applications to...

  17. 76 FR 9346 - Sun City Project LLC; Supplemental Notice That Initial Market-Based Rate Filing Includes Request...

    Science.gov (United States)

    2011-02-17

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Sun City Project LLC; Supplemental Notice That Initial Market- Based Rate...-referenced proceeding of Sun City Project LLC's application for market-based rate authority, with...

  18. dCache: implementing a high-end NFSv4.1 service using a Java NIO framework

    CERN Document Server

    CERN. Geneva

    2012-01-01

    dCache is a high performance scalable storage system widely used by HEP community. In addition to set of home grown protocols we also provide industry standard access mechanisms like WebDAV and NFSv4.1. This support places dCache as a direct competitor to commercial solutions. Nevertheless conforming to a protocol is not enough; our implementations must perform comparably or even better than commercial systems. To achieve this, dCache uses two high-end IO frameworks from well know application servers: GlassFish and JBoss. This presentation describes how we implemented an rfc1831 and rfc2203 compliant ONC RPC (Sun RPC) service based on the Grizzly NIO framework, part of the GlassFish application server. This ONC RPC service is the key component of dCache’s NFSv4.1 implementation, but is independent of dCache and available for other projects. We will also show some details of dCache NFS v4.1 implementations, describe some of the Java NIO techniques used and, finally, present details of our performance e...

  19. CE-318太阳光度计在大气环境监测中的应用%Application of CE-318 Sun Photometer in Atmospheric Environmental Monitoring

    Institute of Scientific and Technical Information of China (English)

    李礼; 余家燕; 杨灿; 唐晓

    2012-01-01

    CE-318 sun photometer plays an important role in atmospheric environmental monitoring and research by scanning the direct solar radiation and sky light automatically and the optical characteristics of atmospheric aerosol can be obtained through specific inversion calculation.The instrument structure,measuring work procedure and inversion algorithm of CE-318 sun photometer were introduced in this paper.The monitoring result of atmospheric angstrom wavelength index in 2010 Chongqing was briefly analyzed.%CE-318太阳光度计自动进行太阳直接辐射和天空光扫描探测,通过反演计算可获取大气气溶胶各种光学特性,在大气环境监测与研究领域发挥着重要作用。介绍了CE-318太阳光度计的仪器结构、测量工作程序和反演算法,并对2010年重庆城区大气Angstrom波长指数测量结果进行了简要分析。

  20. Finding the lost siblings of the Sun

    Science.gov (United States)

    Liu, Cheng; Feltzing, Sofia; Ruchti, Gregory

    2014-01-01

    We have performed a spectral analysis on 18 stars solar sibling candidate. We found that only one one of the candidateshas solar metallicity and at the same time might have an age comparable to that of the Sun.

  1. Sun and Other Types of Radiation

    Science.gov (United States)

    ... What Causes Cancer? Sun and Other Types of Radiation Learn about the different types of radiation and ... other diseases. Learn more here. Other Types of Radiation Exposure Not all types of radiation have been ...

  2. Sun behaviour after cutaneous malignant melanoma

    DEFF Research Database (Denmark)

    Idorn, L W; Datta, P; Heydenreich, J

    2013-01-01

    Background  It has been reported that patients with cutaneous malignant melanoma (CMM) can lower their risk of a second primary melanoma by limiting recreational sun exposure. Previous studies based on questionnaires and objective surrogate measurements indicate that before their diagnosis......, patients with CMM are exposed to higher ultraviolet radiation (UVR) doses than controls, followed by a reduction after diagnosis. Objectives  In a prospective, observational case-control study, we aimed to assess sun exposure after diagnosis of CMM by objective measurements to substantiate advice about sun...... months and 6 years before the start of the study. During a summer season participants filled in sun exposure diaries daily and wore personal electronic UVR dosimeters in a wristwatch that continuously measured time-stamped UVR doses in standard erythema dose. Results  The UVR dose of recently diagnosed...

  3. UV Photography Shows Hidden Sun Damage

    Science.gov (United States)

    ... mcat1=de12", ]; for (var c = 0; c UV photography shows hidden sun damage A UV photograph gives ... developing skin cancer and prematurely aged skin. Normal photography UV photography 18 months of age: This boy's ...

  4. Nilaja Sun's "No Child...": Reflections on Success

    Science.gov (United States)

    Sun, Nilaja; Alexander, Phillip; Huldeen, Branden; Russell, Ron; Friedman, Melissa

    2007-01-01

    This article describes Nilaja Sun's groundbreaking one-woman show about a TA, her students, and her school, and includes interviews with the author/performer, an excerpt of the work, and a discussion of the organization behind it.

  5. The Sun murrab Baltimaadesse ja Soome

    Index Scriptorium Estoniae

    2008-01-01

    Aprillis andis ansambel Tanel Padar & The Sun Soomes, Lätis, Leedus ja Eestis üksteist kontserti. Heliplaadi "Here Gomes The Sun" lugu "Hopelessness You" on Soome raadiote tipp 300s neljakümnendal kohal, lugu "Learn the game" on Leedu FM99 raadios 33 enim mängitava loo seas, laul "One of those days" saavutas Läti raadio SWH rokkmuusika edetabelis teise koha.

  6. The Sun murrab Baltimaadesse ja Soome

    Index Scriptorium Estoniae

    2008-01-01

    Aprillis andis ansambel Tanel Padar & The Sun Soomes, Lätis, Leedus ja Eestis üksteist kontserti. Heliplaadi "Here Gomes The Sun" lugu "Hopelessness You" on Soome raadiote tipp 300s neljakümnendal kohal, lugu "Learn the game" on Leedu FM99 raadios 33 enim mängitava loo seas, laul "One of those days" saavutas Läti raadio SWH rokkmuusika edetabelis teise koha.

  7. How to Observe the Sun Safely

    CERN Document Server

    Macdonald, Lee

    2012-01-01

    How to Observe the Sun Safely, Second Edition gives all the basic information and advice the amateur astronomer needs to get started in observing our own ever-fascinating star. Unlike many other astronomical objects, you do not need a large telescope or expensive equipment to observe the Sun. And it is possible to take excellent pictures of the Sun with today's low-cost digital cameras! This book surveys what is visible on the Sun and then describes how to record solar features and measure solar activity levels. There is also an account of how to use H-alpha and Calcium-K filters to observe and record prominences and other features of the solar chromosphere, the Sun's inner atmosphere. Because we are just entering a period of high activity on the Sun, following a long, quiet period, this is a great time to get involved with solar observing. Still emphasizing safety first, this Second Edition reflects recent and exciting advances in solar observing equipment. Chapters 6 through 8 have been completely revised ...

  8. Orientation in birds. The sun compass.

    Science.gov (United States)

    Schmidt-Koenig, K; Ganzhorn, J U; Ranvaud, R

    1991-01-01

    The sun compass was discovered by G. Kramer in caged birds showing migratory restlessness. Subsequent experiments with caged birds employing directional training and clock shifts, carried out by Hoffman and Schmidt-Koenig, showed that the sun azimuth is used, and the sun altitude ignored. In the laboratory, McDonald found the accuracy to be +/- 3 degrees(-)+/- 5 degrees. According to Hoffmann and Schmidt-Koenig, caged birds trained at medium northern latitudes were able to allow for the sun's apparent movement north of the arctic circle, but not in equatorial and trans-equatorial latitudes. In homing experiments, and employing clock shifts, Schmidt-Koenig demonstrated that the sun compass is used by homing pigeons during initial orientation. This finding is the principal evidence for the existence of a map-and-compass navigational system. Pigeons living in equatorial latitudes utilize the sun compass even under the extreme solar conditions of equinox, achieving angular resolution of about 3 degrees in homing experiments. According to preliminary analyses, the homing pigeons' ephemerides are retarded by several weeks (Ranvaud, Schmidt-Koenig, Ganzhorn et al.).

  9. SunPy: Solar Physics in Python

    Science.gov (United States)

    Ryan, Daniel; Christe, Steven; Mumford, Stuart; Perez Suarez, David; Ireland, Jack; Shih, Albert Y.; Inglis, Andrew; Liedtke, Simon; Hewett, Russel

    2015-04-01

    SunPy is a community-developed open-source software library for solar physics. It is written in Python, a free, cross-platform, general-purpose, high-level programming language which is being increasingly adopted throughout the scientific community as well as further afield. This has resulted in a wide array of software packages useful for scientific computing, from numerical computation (NumPy, SciPy, etc.), to machine learning (scifitlearn), to visualization and plotting (matplotlib). SunPy aims to provide required specialised software for analysing solar and heliospheric datasets in Python. The current version is 0.5 with 0.6 expected to be released later this year. SunPy provides solar data access through integration with the Virtual Solar Observatory (VSO), the Heliophysics Event Knowledgebase (HEK), and the HELiophysics Integrated Observatory (HELIO) webservices. It supports common data types from major solar missions such as images (SDO/AIA, STEREO, PROBA2/SWAP etc.), time series (GOES/XRS, SDO/EVE, PROBA2/LYRA), and radio spectra (e-Callisto, STEREO/WAVES). SunPy’s code base is publicly available through github.com and can be contributed to by anyone. In this poster we demonstrate SunPy’s functionality and future goals of the project. We also encourage interested users to become involved in further developing SunPy.

  10. Implications of advanced warning messages on eliminating sun glare disturbances at signalized intersections

    Directory of Open Access Journals (Sweden)

    Qing Li

    2016-08-01

    Full Text Available Due to sun glare disturbances, drivers encounter fatal threats on roadways, particularly at signalized intersections. Many studies have attempted to develop applicable solutions, such as avoiding sun positions, applying road geometric re-directions, and wearing anti-glare glasses. None of these strategies have fully solved the problem. As one of the “Connected Vehicle” practices proposed by the U.S. Department of Transportation, advanced warning messages (AWMs are capable of providing wireless information about traffic controls. AWM acts as a supplement to conventional signs and signals, which can be blocked by obstacles or natural disturbances, such as sun glare. The drivers' smart advisory system (DSAS can provide drivers with AWM. Using a driving simulator this research explores the effects of DSAS messages on driving behaviors under sun glare disturbance. Statistical analyses were applied to assess (1 the negative impacts of sun glare, (2 the compensation of the DSAS AWM to sun glare effects, and (3 the improvement in driving performance due to DSAS AWM. Four performance indexes were measured, including (1 half kinetic energy speed, (2 mean approach speed, (3 brake response time, and (4 braking distance. The effects of the socio-demographic factors, such as gender, age, educational background, and driving experience were also studied. The analytical results illustrate that the DSAS can compensate for reduced visibility due to sun glare and improve driving performance to a normal visual situation, particularly for left turn and through movement.

  11. Application of Combing the Solar Energy and Noise Reduction in the Outdoor Sun-Shading Louver%太阳能减噪结合板在建筑室外遮阳百叶中的应用研究

    Institute of Scientific and Technical Information of China (English)

    阎国鹏; 敖永安; 许志鹏; 郝亚芬; 邱峰

    2014-01-01

    The study is aimed to apply the solar panel combined with the PVC noise reduction hole board into the outdoor sun-shading louver so that it could improve the light environment and sound envi-ronment of the building and reduce the energy consumption. The sun-shading louver composing of the solar panel and PVC noise reduction hole board installed in the existing buildings is tested, compared with the original building, and analyzing its effects of energy efficiency and noise reduction performance. Through comparing the effects of energy efficiency with or without the sun-shading louver set, it found that in Bei-jing area, under the certain structure, every 100 square meters of solar panel can save 1.52 tons of standard coal, while the noise reduction board can reduce 10%~20% noise indoor. The result shows that the certain structure of the outdoor sun-shading louvers can decrease some sunlight from outdoor into indoor in sum-mer and reduce the noise from outdoor while providing the necessary sunshine in winter. The structure is simple and durable, while it can reduce the load of heating and air-conditioning and save energy.%将太阳能光电转换板与PVC减噪孔板结合应用于建筑遮阳百叶中,在改善建筑光环境的同时对建筑声环境与能耗有所改善。在已有建筑中,将太阳能光电转换板与PVC减噪孔板结合构成建筑遮阳百叶的叶片,在保证系统遮阳性能的条件下,与原有建筑对比测试,分析太阳能减噪结合板节能效益和减噪性能。通过对比遮阳板设置前后得到太阳能减噪结合板的节能效益,发现在北京地区在一定的设计结构下,每使用100 m2太阳能光电转换板能节约1.52吨标准煤,减噪板能减少10%~20%的室内噪音。一定结构的太阳能减噪结合板遮阳百叶可减少夏季进入室内的阳光,能保证冬季必要日照的同时减少进入建筑室内的噪音;结构简单,耐用,可减少建筑供暖和空调

  12. Challenges for asteroseismic analysis of Sun-like stars

    CERN Document Server

    Chaplin, W J; Appourchaux, T; Elsworth, Y; New, R; Toutain, T

    2008-01-01

    Asteroseismology of Sun-like stars is undergoing rapid expansion with, for example, new data from the CoRoT mission and continuation of ground-based campaigns. There is also the exciting upcoming prospect of NASA's Kepler mission, which will allow the asteroseismic study of several hundred Sun-like targets, in some cases for periods lasting up to a few years. The seismic mode parameters are the input data needed for making inference on stars and their internal structures. In this paper we discuss the ease with which it will be possible to extract estimates of individual mode parameters, dependent on the mass, age, and visual brightness of the star. Our results are generally applicable; however, we look at mode detectability in the context of the upcoming Kepler observations. To inform our discussions we make predictions of various seismic parameters. To do this we use simple empirical scaling relations and detailed pulsation computations of the stochastic excitation and damping characteristics of the Sun-like...

  13. Usable Electricity from the Sun.

    Science.gov (United States)

    Energy Research and Development Administration, Washington, DC. Div. of Solar Energy.

    This brochure gives an overview to solar photovoltaic energy production. Some of the topics discussed are: (1) solar cell construction; (2) parallel and series cell arrays; (3) effects of location on solar cell array performance; (4) solar economics; (5) space aplications of solar photovoltaic power; and (6) terrestrial applications of solar…

  14. Synthetic Spectroscopy and Photometry for the Sun

    Science.gov (United States)

    Bell, R. A.

    1993-05-01

    The availability of a digital version of the solar line spectrum (Kitt Peak Preliminary Solar Atlas, Brault & Testerman 1972) has made it possible to carry out detailed comparisons of observed and synthetic spectra. The more accurately the spectrum of the Sun, and other standard stars, can be reproduced, the more likely the line list is to give reliable results in other applications. Detailed comparisons have been made using three lists. The first two are: 1) One which has been used repeatedly by the author and collaborators e.g. Bell, Dickens & Gustafsson (ApJ,229,604,1979); Tripicco & Bell (AJ,103,1285,1992); 2) One derived from Kurucz (Stellar Atmospheres: Beyond Classical Models, Kluwer, Dordrecht, p408,1991) for elements between Ca and Ni, supplemented with lines for other elements from Kurucz & Peytremann (SAO Spec Rept 362,1975) and molecular lines from the author's list (e.g. Bell & Gustafsson MNRAS,236,653,1989). The Kurucz list predicts many lines in the solar spectrum which are either not seen or are observed to be far weaker. The errors in oscillator strength may exceed a factor of 10. On the other hand, there are not a corresponding number of lines which are observed but which are not present in the synthetic spectra. Needless to say, this excess in the computed line absorption will affect the calculation of both model atmospheres and synthetic magnitudes. For example, the computed U-B colors will be too red. In view of these errors, and the much better fit which spectra calculated using the author's lists give to the solar line spectrum, the Kurucz list has been used only to fill in gaps in the author's list, thereby creating a third list. This list also incorporates new laboratory gf values (e.g. O'Brian et al. JOSA B,8,1185,1991). Detailed comparisons of observed and synthetic solar spectra from the different lists are shown.

  15. The sun and space weather Second Edition

    CERN Document Server

    Hanslmeier, Arnold

    2007-01-01

    This second edition is a great enhancement of literature which will help the reader get deeper into the specific topics. There are new sections included such as space weather data sources and examples, new satellite missions, and the latest results. At the end a comprehensive index is given which will allow the reader to quickly find his topics of interest. The Sun and Space weather are two rapidly evolving topics. The importance of the Sun for the Earth, life on Earth, climate and weather processes was recognized long ago by the ancients. Now, for the first time there is a continuous surveillance of solar activity at nearly all wavelengths. These data can be used to improve our understanding of the complex Sun-Earth interaction. The first chapters of the book deal with the Sun as a star and its activity phenomena as well as its activity cycle in order to understand the complex physics of the Sun-Earth system. The reader will see that there are many phenomena but still no definite explanations and models exis...

  16. The Sun Sense Study: An Intervention to Improve Sun Protection in Children

    Science.gov (United States)

    Glasser, Alice; Shaheen, Magda; Glenn, Beth A.; Bastani, Roshan

    2010-01-01

    Objectives: To assess the effect of a multicomponent intervention on parental knowledge, sun avoidance behaviors, and sun protection practices in children 3-10 years. Methods: A randomized trial at a pediatric clinic recruited 197 caregiver-child pairs (90% parents). Intervention included a brief presentation and brochure for the parent and…

  17. After the Bell: Developing Sun Sense--Learning about Protection from the Sun's Rays

    Science.gov (United States)

    Farenga, Stephen J.; Ness, Daniel

    2008-01-01

    The American Academy of Dermatology (2008) reports that our students will experience 80% of their lifetime exposure to the Sun by the time they are 18. Further, research has demonstrated that continued exposure to the Sun's ultraviolet rays can lead to skin aging, sunburn, immune suppression, ocular melanoma, cataracts, corneal burns, and even…

  18. A sun holiday is a sunburn holiday

    DEFF Research Database (Denmark)

    Petersen, Bibi; Thieden, Elisabeth; Philipsen, Peter Alshede

    2013-01-01

    Many people take holidays in sunny locations with the express aim of sunbathing. This may result in sunburn, which is a risk factor for skin cancer. We investigated 25 Danish sun seekers during a week's holiday in the Canary Islands. The percentage of body surface area with sunburn was determined......-specific UVR doses after adjustment for sun protection factor. Remarkably, we found that all volunteers sunburned at some point. The risk of sunburn correlated significantly with the adjusted body site-specific UVR dose. Furthermore, there was also a significant relationship between the daily UVR dose...... and percentage of body surface area with sunburn. Our study shows that holiday UVR exposure results in a high risk of sunburn, which potentially increases the risk of skin cancer. Possible protection by melanogenesis is insufficient to protect against sunburn during a 1-week sun holiday. Finally, our data...

  19. Precise nuclear physics for the sun

    Energy Technology Data Exchange (ETDEWEB)

    Bemmerer, Daniel

    2012-07-01

    For many centuries, the study of the Sun has been an important testbed for understanding stars that are further away. One of the first astronomical observations Galileo Galilei made in 1612 with the newly invented telescope concerned the sunspots, and in 1814, Joseph von Fraunhofer employed his new spectroscope to discover the absorption lines in the solar spectrum that are now named after him. Even though more refined and new modes of observation are now available than in the days of Galileo and Fraunhofer, the study of the Sun is still high on the agenda of contemporary science, due to three guiding interests. The first is connected to the ages-old human striving to understand the structure of the larger world surrounding us. Modern telescopes, some of them even based outside the Earth's atmosphere in space, have succeeded in observing astronomical objects that are billions of light-years away. However, for practical reasons precision data that are important for understanding stars can still only be gained from the Sun. In a sense, the observations of far-away astronomical objects thus call for a more precise study of the closeby, of the Sun, for their interpretation. The second interest stems from the human desire to understand the essence of the world, in particular the elementary particles of which it consists. Large accelerators have been constructed to produce and collide these particles. However, man-made machines can never be as luminous as the Sun when it comes to producing particles. Solar neutrinos have thus served not only as an astronomical tool to understand the Sun's inner workings, but their behavior on the way from the Sun to the Earth is also being studied with the aim to understand their nature and interactions. The third interest is strictly connected to life on Earth. A multitude of research has shown that even relatively slight changes in the Earth's climate may strongly affect the living conditions in a number of densely

  20. Neptune as a Mirror for the Sun

    Science.gov (United States)

    Kohler, Susanna

    2017-01-01

    How would the Kepler mission see a star like the Sun? We now know the answer to this question due to a creative approach: a new study has used the Kepler K2 mission to detect signals from the Sun reflected off of the surface of Neptune.Asteroseismology uses different oscillation modes of a star to probe its internal structure and properties. [Tosaka]Information in OscillationsKeplers most glamorous work is in discovering new planets around other stars. To successfully do this, however, the spacecraft is also quietly doing a lot of very useful work in the background, characterizing the many stars in our vicinity that planets might be found around.One of the ways Kepler gets information about these stars is from oscillations of the stars intensities. In asteroseismology, we look at oscillatory modes that are caused by convection-driven pressure changes on the inside of the star. All stars with near-surface convection oscillate like this including the Sun and by measuring the oscillations in intensity of these stars, we can make inferences about the stars properties.A Planetary MirrorWe do this by first understanding our Suns oscillations especially well (made easier by the fact that its nearby!). Then we use asteroseimic scaling relations determined empirically that relate characteristics like mass and radius of other stars to those of the Sun, based on the relation between the stars oscillation properties to the Suns.The trouble is, those oscillation properties are difficult to measure, and different instruments often measure different values. For this reason, wed like to measure the Suns oscillations with the same instrument we use to measure other stars oscillations: Kepler.Top panel: Kepler K2 49-day light curve of Neptune. Bottom panel: power density spectrum as a function of frequency (grey). Neptunes rotation frequencies and harmonics appear toward the left side (blue); the excess power due to the solar modes is visible toward the bottom right. The green curve

  1. The Spectrum of Darkonium in the Sun

    CERN Document Server

    Kouvaris, Chris; Nielsen, Niklas Grønlund

    2016-01-01

    Dark matter that gets captured in the Sun may form positronium-like bound states if it self-interacts via light dark photons. In this case, dark matter can either annihilate to dark photons or recombine in bound states which subsequently also decay to dark photons. The fraction of the dark photons that leave the Sun without decaying to Standard Model particles have a characteristic energy spectrum which is a mixture of the direct annihilation process, the decays of ortho- and para- bound states and the recombination process. The ultimate decay of these dark photons to positron-electron pairs (via kinetic mixing) outside the Sun creates a distinct signal that can either identify or set strict constraints on dark photon models.

  2. The spectrum of darkonium in the Sun

    Science.gov (United States)

    Kouvaris, Chris; Langæble, Kasper; Grønlund Nielsen, Niklas

    2016-10-01

    Dark matter that gets captured in the Sun may form positronium-like bound states if it self-interacts via light dark photons. In this case, dark matter can either annihilate to dark photons or recombine in bound states which subsequently also decay to dark photons. The fraction of the dark photons that leave the Sun without decaying to Standard Model particles have a characteristic energy spectrum which is a mixture of the direct annihilation process, the decays of ortho- and para- bound states and the recombination process. The ultimate decay of these dark photons to positron-electron pairs (via kinetic mixing) outside the Sun creates a distinct signal that can either identify or set strict constraints on dark photon models.

  3. The sun since the Bronze Age

    Science.gov (United States)

    Eddy, J. A.

    1976-01-01

    An investigation is conducted concerning the behavior of the sun during the last 7000 years. The C-14 content in carbonaceous fossil material can be used as an indicator regarding the level of solar activity at the time when the carbon was assimilated in the process of photosynthesis. Living trees, such as the bristlecone pine, provide a solar activity record to about 3000 B.C. The record can be extended with the aid of well-preserved dead wood to beyond 5000 B.C. The results of an analysis of solar activity levels as a function of time on the basis of C-14 contents are presented in a graph. Attention is given to the Maunder Minimum, a history of the sun in the last 5000 years, an interpretation of the major C-14 excursions, and the sun and climate history.

  4. 'My Sun' and 'Guided by the Moon'

    Directory of Open Access Journals (Sweden)

    Rebecca Baillie

    2013-07-01

    Full Text Available My Sun and Guided by the Moon (2012 show the heavily pregnant artist with her swollen belly covered in gold and silver leaf. The work is suggestive that the connectivity experienced by an expectant mother, extends outwards, even as far as her relationship with the cosmos. The 'sun' portrait was taken on a bright September morning, and its partner image, the following October, on the night of a full moon. Female cycles and the importance of time passing during a pregnancy are referenced. Interestingly, bearing in mind that the artist gave birth to a son in November, creating the 'moon' portrait felt like a familiar, empowering and yet isolated expression of selfhood, whilst the 'sun/son' version exuded the energy of a collaboration, and stimulated feelings of joy, liberation and potentiality. By seeming contradiction, the boy was born on a full moon, exactly a month to the day that Guided by the Moon was taken.

  5. Semiautomatic sun shots with the WIDIF DIflux

    Directory of Open Access Journals (Sweden)

    J. L. Rasson

    2017-07-01

    Full Text Available The determination of magnetic declination angle entails finding two directions: geographic north and magnetic north. This paper deals with the former. The known way to do it by using the sun's calculable orientation in the sky is improved by using a device based on a WIDIF DIflux theodolite and split photocells positioned on its telescope ocular. Given the WIDIF accurate timing and location provided by the onboard GPS receiver, an astronomical computation can be effected to accurately and quickly determine the sun's azimuth and an auxiliary mark's azimuth. The precise sun's crossing of the split photocell, amplified by the telescope's magnification, allows azimuth accuracies of a few seconds of arc.

  6. The sun and heliosphere at solar maximum.

    Science.gov (United States)

    Smith, E J; Marsden, R G; Balogh, A; Gloeckler, G; Geiss, J; McComas, D J; McKibben, R B; MacDowall, R J; Lanzerotti, L J; Krupp, N; Krueger, H; Landgraf, M

    2003-11-14

    Recent Ulysses observations from the Sun's equator to the poles reveal fundamental properties of the three-dimensional heliosphere at the maximum in solar activity. The heliospheric magnetic field originates from a magnetic dipole oriented nearly perpendicular to, instead of nearly parallel to, the Sun's rotation axis. Magnetic fields, solar wind, and energetic charged particles from low-latitude sources reach all latitudes, including the polar caps. The very fast high-latitude wind and polar coronal holes disappear and reappear together. Solar wind speed continues to be inversely correlated with coronal temperature. The cosmic ray flux is reduced symmetrically at all latitudes.

  7. Haloes around the Moon and the Sun

    Science.gov (United States)

    Gaina, Alex; Gaina, Danielle A.

    2008-10-01

    The authors observations of the Haloes around the Moon and the Sun during few last years are reported. A Historical review of the phenomenon is given since the observations by Benvenuto Cellini and Gaston Tissandier is given. A photograph (from eight available) of the Halo around the Sun observed in Chisinau on 21 May 2007 is included. The Halo from 21 May 2007 occured after a very fast increasing of the air temperature during one day by more than 15 Deg. The authors consider, that the phenomenon is due to scattering of light on Cirri clouds(7 km altitude), present on the sky during that day. They formed due to very fast heating.

  8. SunShot Initiative Fact Sheet

    Energy Technology Data Exchange (ETDEWEB)

    DOE Solar Energy Technologies Office

    2015-04-01

    The U.S. Department of Energy (DOE) SunShot Initiative is a collaborative national effort launched in 2011 that aggressively drives innovation to make solar energy fully cost competitive with traditional energy sources before the end of the decade. The SunShot fact sheet outlines goals and successes of the program as it works with private companies, universities, non-profit organizations, state and local governments, and national laboratories to drive down the cost of solar electricity to $0.06 per kilowatt-hour, without incentives, by the year 2020.

  9. Radio emission of the sun and planets

    CERN Document Server

    Zheleznyakov, V V

    1970-01-01

    International Series of Monographs in Natural Philosophy, Volume 25: Radio Emission of the Sun and Planets presents the origin of the radio emission of the planets. This book examines the outstanding triumphs achieved by radio astronomy of the solar system. Comprised of 10 chapters, this volume begins with an overview of the physical conditions in the upper layers of the Sun, the Moon, and the planets. This text then examines the three characteristics of radio emission, namely, the frequency spectrum, the polarization, and the angular spectrum. Other chapters consider the measurements of the i

  10. Improved Laboratory Transition Probabilities for Ce II, Application to the Cerium Abundances of the Sun and Five r-process Rich, Metal-Poor Stars, and Rare Earth Lab Data

    CERN Document Server

    Lawler, J E; Cowan, J J; Ivans, I I; Hartog, E A Den

    2009-01-01

    Recent radiative lifetime measurements accurate to +/- 5% using laser-induced fluorescence (LIF) on 43 even-parity and 15 odd-parity levels of Ce II have been combined with new branching fractions measured using a Fourier transform spectrometer (FTS) to determine transition probabilities for 921 lines of Ce II. This improved laboratory data set has been used to determine a new solar photospheric Ce abundance, log epsilon = 1.61 +/- 0.01 (sigma = 0.06 from 45 lines), a value in excellent agreement with the recommended meteoritic abundance, log epsilon = 1.61 +/- 0.02. Revised Ce abundances have also been derived for the r-process-rich metal-poor giant stars BD+17 3248, CS 22892-052, CS 31082-001, HD 115444 and HD 221170. Between 26 and 40 lines were used for determining the Ce abundance in these five stars, yielding a small statistical uncertainty of 0.01 dex similar to the Solar result. The relative abundances in the metal-poor stars of Ce and Eu, a nearly pure r-process element in the Sun, matches r-process ...

  11. Application of Photoelectric Position Sensor in High Precision Automatic Sun Tracker%光电位置传感器在高精度太阳自动对准中的应用

    Institute of Scientific and Technical Information of China (English)

    曲春英; 卞秀芬

    2016-01-01

    To improve the utilization rate of solar energy,the current problems of sun tracking is analyzed,the solar spotlight system is developed based on photoelectric position sensor;the tracking device is designed to achieve sta⁃bility;tracking strategy adopts photoelectric tracking combined with calendar-reckoning,and all-weather automatic tracking was realized. Experimental results show the method is simple,and it has high tracking precision,good sta⁃bility.%分析了目前太阳跟踪方式中存在的问题,为进一步提高太阳跟踪精度和利用率,设计了基于光电位置传感器的太阳追光系统;设计了跟踪装置,达到了跟踪的稳定性;跟踪策略上采用光电跟踪与视日跟踪相结合,实现了全天候自动跟踪。经试验表明:该方法简单,跟踪精度高,稳定性好。

  12. A new method of single celestial-body sun positioning based on theory of mechanisms

    Institute of Scientific and Technical Information of China (English)

    Zhang Wei; Xu Xiaofeng; Wu Yuanzhe

    2016-01-01

    Considering defects of current single celestial-body positioning methods such as discon-tinuity and long period, a new sun positioning algorithm is herein put forward. Instead of tradi-tional astronomical spherical trigonometry and celestial coordinate system, the proposed new positioning algorithm is built by theory of mechanisms. Based on previously derived solar vector equations (from a C1R2P2 series mechanism), a further global positioning method is developed by inverse kinematics. The longitude and latitude coordinates expressed by Greenwich mean time (GMT) and solar vector in local coordinate system are formulated. Meanwhile, elimination method of multiple solutions, errors of longitude and latitude calculation are given. In addition, this algo-rithm has been integrated successfully into a mobile phone application to visualize sun positioning process. Results of theoretical verification and smart phone’s test demonstrate the validity of pre-sented coordinate’s expressions. Precision is shown as equivalent to current works and is acceptable to civil aviation requirement. This new method solves long-period problem in sun sight running fix-ing and improves applicability of sun positioning. Its methodology can inspire development of new sun positioning device. It would be more applicable to be combined with inertial navigation systems for overcoming discontinuity of celestial navigation systems and accumulative errors of inertial nav-igation systems.

  13. A new method of single celestial-body sun positioning based on theory of mechanisms

    Directory of Open Access Journals (Sweden)

    Zhang Wei

    2016-02-01

    Full Text Available Considering defects of current single celestial-body positioning methods such as discontinuity and long period, a new sun positioning algorithm is herein put forward. Instead of traditional astronomical spherical trigonometry and celestial coordinate system, the proposed new positioning algorithm is built by theory of mechanisms. Based on previously derived solar vector equations (from a C1R2P2 series mechanism, a further global positioning method is developed by inverse kinematics. The longitude and latitude coordinates expressed by Greenwich mean time (GMT and solar vector in local coordinate system are formulated. Meanwhile, elimination method of multiple solutions, errors of longitude and latitude calculation are given. In addition, this algorithm has been integrated successfully into a mobile phone application to visualize sun positioning process. Results of theoretical verification and smart phone’s test demonstrate the validity of presented coordinate’s expressions. Precision is shown as equivalent to current works and is acceptable to civil aviation requirement. This new method solves long-period problem in sun sight running fixing and improves applicability of sun positioning. Its methodology can inspire development of new sun positioning device. It would be more applicable to be combined with inertial navigation systems for overcoming discontinuity of celestial navigation systems and accumulative errors of inertial navigation systems.

  14. BcSUN1, a B. cinerea SUN-Family Protein, Is Involved in Virulence

    Science.gov (United States)

    Pérez-Hernández, Alicia; González, Mario; González, Celedonio; van Kan, Jan A. L.; Brito, Nélida

    2017-01-01

    BcSUN1 is a glycoprotein secreted by Botrytis cinerea, an important plant pathogen that causes severe losses in agriculture worldwide. In this work, the role of BcSUN1 in different aspects of the B. cinerea biology was studied by phenotypic analysis of Bcsun1 knockout strains. We identified BcSUN1 as the only member of the Group-I SUN family of proteins encoded in the B. cinerea genome, which is expressed both in axenic culture and during infection. BcSUN1 is also weakly attached to the cellular surface and is involved in maintaining the structure of the cell wall and/or the extracellular matrix. Disruption of the Bcsun1 gene produces different cell surface alterations affecting the production of reproductive structures and adhesion to plant surface, therefore reducing B. cinerea virulence. BcSUN1 is the first member of the SUN family reported to be involved in the pathogenesis of a filamentous fungus. PMID:28163701

  15. Sun exposure and sun protection practices of children and their parents.

    LENUS (Irish Health Repository)

    Kiely, A D

    2009-05-01

    The primary aims of this study were: to estimate sun exposure in hours of children in Cork during the summer months; to examine sun protection measures used by children and their parents and to explore parental knowledge of sun exposure and protection. A cross-sectional study, using a semi-structured questionnaire, was conducted in June 2006 in primary schools, pre-schools and creches throughout Cork City and County. Parents of 250 children aged less than 12 years were sampled. Mean sun exposure of Cork children was 40.9 hours per week in the summer months, with 77 (46.1%) children developing sunburn. 59.3% of the studied children were of skin type 1 or 2. 95 (57%) children on weekdays and 137 (82%) children at weekends were exposed to the sun between 11 am and 3 pm. Sunscreen and hats\\/caps were the most common protection measures used. A minority used protective clothing, sunglasses or sought shade. Thirty one (30.5%) children had sunscreen reapplied every 2 hours. Knowledge of sun protection was considerable among Irish parents. However the frequency of sunburn among Irish children suggests we are not providing them with adequate sun protection.

  16. Rational SU(N) Gaudin Model

    Institute of Scientific and Technical Information of China (English)

    曹俊鹏; 侯伯宇; 岳瑞宏

    2001-01-01

    We propose the eigenstates and eigenvalues of Hamiltonians of the rational SU(N) Gaudin model based onthe quasi-classical limit of the SU ( N) chain under the periodic boundary condition. Using the quantum inversescattering method, we also obtain the eigenvalues of the generation function of the rational SU ( N) Gaudin model.

  17. Asymmetric dark matter and the Sun

    DEFF Research Database (Denmark)

    Frandsen, Mads Toudal; Sarkar, Subir

    2010-01-01

    Cold dark matter particles with an intrinsic matter-antimatter asymmetry do not annihilate after gravitational capture by the Sun and can affect its interior structure. The rate of capture is exponentially enhanced when such particles have self-interactions of the right order to explain structure...

  18. SunPy - Python for Solar Physics

    CERN Document Server

    Community, The SunPy; Christe, Steven; Pérez-Suárez, David; Ireland, Jack; Shih, Albert Y; Inglis, Andrew R; Liedtke, Simon; Hewett, Russell J; Mayer, Florian; Hughitt, Keith; Freij, Nabil; Meszaros, Tomas; Bennett, Samuel M; Malocha, Michael; Evans, John; Agrawal, Ankit; Leonard, Andrew J; Robitaille, Thomas P; Mampaey, Benjamin; Campos-Rozo, Jose Iván; Kirk, Michael S

    2015-01-01

    This paper presents SunPy (version 0.5), a community-developed Python package for solar physics. Python, a free, cross-platform, general-purpose, high-level programming language, has seen widespread adoption among the scientific community, resulting in the availability of a large number of software packages, from numerical computation (NumPy, SciPy) and machine learning (scikit-learn) to visualisation and plotting (matplotlib). SunPy is a data-analysis environment specialising in providing the software necessary to analyse solar and heliospheric data in Python. SunPy is open-source software (BSD licence) and has an open and transparent development workflow that anyone can contribute to. SunPy provides access to solar data through integration with the Virtual Solar Observatory (VSO), the Heliophysics Event Knowledgebase (HEK), and the HELiophysics Integrated Observatory (HELIO) webservices. It currently supports image data from major solar missions (e.g., SDO, SOHO, STEREO, and IRIS), time-series data from mis...

  19. Essential Outdoor Sun Safety Tips for Winter

    Science.gov (United States)

    ... ve Got Skin in the Game Anti-Aging Vitamin D Related: What Is Skin Cancer? | True Stories | Ask the Experts Blog Events ... Weekend Warriors expand/collapse Golf: You've Got Skin in the Game expand/collapse Vitamin D Essential Outdoor Sun Safety Tips for Winter ...

  20. Sino-Sun Architects & Engineers

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Sino-Sun is an A-Class state architectural design company organized by a group of experts who have returned to China after studying abroad. In the 10 yearssince its establishment, it has grown into an outstanding andwell-known design team, which has influence in the national archi-tectural design field.

  1. Ulysses Passes South Pole of Sun

    Institute of Scientific and Technical Information of China (English)

    程林

    1995-01-01

    On the 14th of September,1994, the fastest scientific instrument in space passed the south pole of the Sun,a place where no human-made object has been before. A spaceprobe called Ulysses made the polar pass at about midday as it continued to collect data on the solar wind,a stream of high-energy sub-atomic

  2. Isotopes Tell Sun's Origin and Operation

    Science.gov (United States)

    Manuel, O.; Kamat, Sumeet A.; Mozina, Michael

    2006-03-01

    Modern versions of Aston's mass spectrometer enable measurements of two quantities - isotope abundances and masses - that tell the Sun's origin and operation. Isotope analyses of meteorites, the Earth, Moon, Mars, Jupiter, the solar wind, and solar flares over the past 45 years indicate that fresh, poorly-mixed, supernova debris formed the solar system. The iron-rich Sun formed on the collapsed supernova core and now itself acts as a magnetic plasma diffuser, as did the precursor star, separating ions by mass. This process covers the solar surface with lightweight elements and with the lighter isotopes of each element. Running difference imaging provides supporting evidence of a rigid, iron-rich structure below the Sun's fluid outer layer of lightweight elements. Mass measurements of all 2,850 known nuclides expose repulsive interactions between neutrons that trigger neutron-emission at the solar core, followed by neutron-decay and a series of reactions that collectively generate solar luminosity, solar neutrinos, the carrier gas for solar mass separation, and an outpouring of solar-wind hydrogen from the solar surface. Neutron-emission and neutron-decay generate ~ 65% of solar luminosity; H-fusion ~ 35%, and ~ 1% of the neutron-decay product survives to depart as solar-wind hydrogen. The energy source for the Sun and other ordinary stars seems to be neutron-emission and neutron-decay, with partial fusion of the decay product, rather than simple fusion of hydrogen into helium or heavier elements.

  3. Sun Baiqiu Fights for the Human Cause

    Institute of Scientific and Technical Information of China (English)

    1994-01-01

    SUN Baiqiu liked to read well known literature from all over the world when she was a little girl. She sympathized with the good-hearted characters and hated the greedy and the evil. She imagined that she would become like a fairy godmother, holding a magic wand and helping the poor but kind people in distress. In 1963 she graduated from Haerbin

  4. The Sun in Time: Activity and Environment

    CERN Document Server

    Güdel, M

    2007-01-01

    (abridged) The Sun's magnetic activity has steadily declined during its main-sequence life. While the solar photospheric luminosity was about 30% lower 4.6 Gyr ago when the Sun arrived on the main sequence compared to present-day levels, its faster rotation generated enhanced magnetic activity; magnetic heating processes in the chromosphere, the transition region, and the corona induced ultraviolet, extreme-ultraviolet, and X-ray emission about 10, 100, and 1000 times, respectively, the present-day levels, as inferred from young solar-analog stars. Also, the production rate of accelerated, high-energy particles was orders of magnitude higher than in present-day solar flares, and a much stronger wind escaped from the Sun, permeating the entire solar system. The consequences of the enhanced radiation and particle fluxes from the young Sun were potentially severe for the evolution of solar-system planets and moons. Interactions of high-energy radiation and the solar wind with upper planetary atmospheres may have...

  5. 《孙子兵法》谋略思想与警务危机谈判运用研究%On the Application of Sun Tzu's Strategic Thought to the Police Crisis Negotiation

    Institute of Scientific and Technical Information of China (English)

    孙良玉

    2015-01-01

    Sun Tzu's art of strategic thought and the operational principle and strategy and tactics, can draw lessons in the field of police negotiation and be applied to police negotiation practice.The study of the close relationship between "knowing each other, fighting without failure", negotiation preparation, the police personnel quality of "wisdom, trust, kindness, bravery, strictness", negotiation skills with the police of "avoiding the virtual strike"and the police negotiation functions can help the police negotiators take better means, negotiation strategy and more useful methods to solve practical problems.%《孙子兵法》中论述的很多谋略思想、作战原则以及战略战术,完全能够借鉴到警务危机谈判领域中,运用于警务危机谈判实践中。研究“知彼知己,百战不殆”与警务危机谈判准备,“智、信、仁、勇、严”与警务危机谈判人员素质,“致人而不致于人”与警务危机谈判推进,“避实击虚”与警务危机谈判技巧,“不战而屈人之兵”与警务危机谈判功能之间的密切联系,可以帮助警务危机谈判人员更好地采取非武力的警务危机谈判手段,运用警务危机谈判谋略,获取更多解决实际问题的有益方法,促使警务危机的和平解决。

  6. School Sun-Protection Policies--Does Being SunSmart Make a Difference?

    Science.gov (United States)

    Turner, Denise; Harrison, Simone L.; Buettner, Petra; Nowak, Madeleine

    2014-01-01

    Evaluate the comprehensiveness of primary school sun-protection policies in tropical North Queensland, Australia. Pre-determined criteria were used to assess publicly available sun-protection policies from primary schools in Townsville (latitude 19.3°S; n = 43), Cairns (16.9°S; n = 46) and the Atherton Tablelands (17.3°S; n = 23) during 2009-2012.…

  7. Observing the Sun with NuSTAR

    Science.gov (United States)

    Kohler, Susanna

    2016-07-01

    The Nuclear Spectroscopic Telescope Array (NuSTAR) is a space telescope primarily designed to detect high-energy X-rays from faint, distant astrophysical sources. Recently, however, its occasionally been pointing much closer to home, with the goal of solving a few longstanding mysteries about the Sun.Intensity maps from an observation of a quiet-Sun region near the north solar pole and an active region just below the solar limb. The quiet-Sun data will be searched for small flares that could be heating the solar corona, and the high-altitude emission above the limb may provide clues about particle acceleration. [Adapted from Grefenstette et al. 2016]An Unexpected TargetThough we have a small fleet of space telescopes designed to observe the Sun, theres an important gap: until recently, there was no focusing telescope making solar observations in the hard X-ray band (above ~3 keV). Conveniently, there is a tool capable of doing this: NuSTAR.Though NuSTARs primary mission is to observe faint astrophysical X-ray sources, a team of scientists has recently conducted a series of observations in which NuSTAR was temporarily repurposed and turned to focus on the Sun instead.These observations pose an interesting challenge precisely because of NuSTARs extreme sensitivity: pointing at such a nearby, bright source can quickly swamp the detectors. But though the instrument cant be used to observe the bright flares and outbursts from the Sun, its the perfect tool for examining the parts of the Sun weve been unable to explore in hard X-rays before now such as faint flares, or the quiet, inactive solar surface.In a recently published study led by Brian Grefenstette (California Institute of Technology), the team describes the purpose and initial results of NuSTARs first observations of the Sun.Solar MysteriesWhat is NuSTAR hoping to accomplish with its solar observations? There are two main questions that hard X-ray observations may help to answer.How are particles accelerated in

  8. A Tracking Sun Photometer Without Moving Parts

    Science.gov (United States)

    Strawa, Anthony W.

    2012-01-01

    This innovation is small, lightweight, and consumes very little electricity as it measures the solar energy attenuated by gases and aerosol particles in the atmosphere. A Sun photometer is commonly used on the Earth's surface, as well as on aircraft, to determine the solar energy attenuated by aerosol particles in the atmosphere and their distribution of sizes. This information is used to determine the spatial and temporal distribution of gases and aerosols in the atmosphere, as well as their distribution sizes. The design for this Sun photometer uses a combination of unique optics and a charge coupled device (CCD) array to eliminate moving parts and make the instrument more reliable. It could be selfcalibrating throughout the year. Data products would be down-welling flux, the direct-diffuse flux ratio, column abundance of gas phase constituents, aerosol optical depth at multiple-wavelengths, phase functions, cloud statistics, and an estimate of the representative size of atmospheric particles. These measurements can be used to obtain an estimate of aerosol size distribution, refractive index, and particle shape. Incident light is received at a light-reflecting (inner) surface, which is a truncated paraboloid. Light arriving from a hemispheric field of view (solid angle 2 steradians) enters the reflecting optic at an entrance aperture at, or adjacent to, the focus of the paraboloid, and is captured by the optic. Most of this light is reflected from an inner surface. The light proceeds substantially parallel to the paraboloid axis, and is detected by an array detector located near an exit aperture. Each of the entrance and exit apertures is formed by the intersection of the paraboloid with a plane substantially perpendicular to the paraboloid axis. Incident (non-reflected) light from a source of limited extent (the Sun) illuminates a limited area on the detector array. Both direct and diffuse illumination may be reflected, or not reflected, before being received on

  9. UV photography, masculinity, and college men's sun protection cognitions.

    Science.gov (United States)

    Walsh, Laura A; Stock, Michelle L

    2012-08-01

    This study examined the impact of an ultraviolet (UV) photography intervention and masculinity on college men's sun protection cognitions, including: perceived vulnerability to skin damage, attitudes toward sun protection, willingness to engage in sun protection behaviors, and intentions to receive a skin cancer exam. After completing a baseline survey, participants (N = 152) viewed a black-and-white photo of their face. Half also viewed a photo showing their UV damage. Participants then completed a second survey assessing sun protection cognitions. Regressions revealed that masculinity predicted lower sun protection cognitions, and men in the UV photograph condition reported higher sun protection cognitions. Masculinity by condition interactions showed that the positive effect of UV photography was stronger among masculine men. Negative associations between masculinity and sun protection cognitions were significant only among men who did not receive the intervention. Findings suggest that UV photography is a promising sun protection intervention among masculine men.

  10. Neutrinos from WIMP annihilations in the Sun including neutrino oscillations

    Energy Technology Data Exchange (ETDEWEB)

    Blennow, Mattias, E-mail: emb@kth.se [Department of Theoretical Physics, School of Engineering Sciences, Royal Institute of Technology (KTH) - AlbaNova University Center, SE-106 91 Stockholm (Sweden); Edsjoe, Joakim, E-mail: edsjo@physto.se [Department of Physics, Stockholm University - AlbaNova University Center, SE-106 91 Stockholm (Sweden); Ohlsson, Tommy, E-mail: tommy@theophys.kth.se [Department of Theoretical Physics, School of Engineering Sciences, Royal Institute of Technology (KTH) - AlbaNova University Center, SE-106 91 Stockholm (Sweden)

    2011-12-15

    The prospects to detect neutrinos from the Sun arising from dark matter annihilations in the core of the Sun are reviewed. Emphasis is placed on new work investigating the effects of neutrino oscillations on the expected neutrino fluxes.

  11. How Can I Protect My Children from the Sun?

    Science.gov (United States)

    ... How Can I Protect My Children from the Sun? Language: English Español (Spanish) Recommend on Facebook Tweet ... other options to prevent UV damage. Too Much Sun Hurts Turning pink? Unprotected skin can be damaged ...

  12. Blinded by the light the secret life of the sun

    CERN Document Server

    Gribbin, John

    1991-01-01

    An investigation into the secrets and the new scientific developments which are changing our perceptions of the sun. The book tackles such questions as: does the sun breathe?; can it make sound?; is its centre ice-cold? The new research in sun science will alter our perception not only of the sun, but of the whole universe and add to the understanding of how the world works. The author has also written "Hothouse Earth" and "The Hole in the Sky".

  13. Observing the sun a pocket field guide

    CERN Document Server

    Jenkins, Jamey L

    2013-01-01

    A comprehensive solar observing guide for use at the telescope by amateur astronomers at all three levels: beginning, intermediate, and advanced. Users will find invaluable information for identifying features through photos, charts, diagrams in a logical, orderly fashion and then interpreting the observations. Because the Sun is a dynamic celestial body in constant flux, astronomers rarely know for certain what awaits them at the eyepiece. All features of the Sun are transient and sometimes rather fleeting. Given the number of features and the complex life cycles of some solar features, it can be a challenging hobby, and this guide provides all of the guidance necessary to inform observers about the sights and events unfolding before their eyes on the most active and powerful member of our Solar System.

  14. Power producing sun shades; Elproducerende solafskaermninger

    Energy Technology Data Exchange (ETDEWEB)

    Johnsen, K.; Soerensen, Henrik; Katic, I.; Schmidt-Petersen, H.; AAroe, D.

    2012-01-15

    Integrating photovoltaics into sun shades takes advantage of the best opportunities to capture and utilize solar energy when the shades are most needed to shield users from solar radiation. The report describes results of a development project for solar shading in the form of broad, horizontal and rotating lamellae with solar cells and an integrated control function that simultaneously is optimized based on energy consumption and thermal and visual indoor climate. The project idea was to meet the needs for effective sun protection in the present office, commercial and public buildings, where glass facades are dominant. The conclusion of the development project is that it rarely would be optimal to integrate solar cells into movable shades. This will normally only be relevant in cases where it is justified by architectural considerations. (LN)

  15. Hierarchical analysis of the quiet Sun magnetism

    CERN Document Server

    Ramos, A Asensio

    2014-01-01

    Standard statistical analysis of the magnetic properties of the quiet Sun rely on simple histograms of quantities inferred from maximum-likelihood estimations. Because of the inherent degeneracies, either intrinsic or induced by the noise, this approach is not optimal and can lead to highly biased results. We carry out a meta-analysis of the magnetism of the quiet Sun from Hinode observations using a hierarchical probabilistic method. This model allows us to infer the statistical properties of the magnetic field vector over the observed field-of-view consistently taking into account the uncertainties in each pixel due to noise and degeneracies. Our results point out that the magnetic fields are very weak, below 275 G with 95% credibility, with a slight preference for horizontal fields, although the distribution is not far from a quasi-isotropic distribution.

  16. A new perspective on quiet Sun magnetism

    Institute of Scientific and Technical Information of China (English)

    LITES; Bruce; William

    2009-01-01

    The Hinode mission has provided us with a new, quantitative view of the magnetism of the quiet Sun. It has revealed that the quiet internetwork areas are blanketed by horizontal fields that appear at first sight to have more flux than the vertical fields resolved on the same 0.3 size scale. These measurements point to the possibility that the horizontal fields might be the primary source of the "hidden turbulent flux" of the quiet Sun anticipated from Hanle effect depolarization. In this paper, evidence is presented suggesting that the "seething" horizontal fields observed by Harvey in 2007 and the horizontal fields revealed by Hinode are the same phenomenon. Because the seething fields appear to be of uniform fluctuation over the whole disk, the phenomenon is most likely not associated with the dynamo source of solar activity. Thus, the small-scale "hidden turbulent flux" lends support to the notion of a local solar dynamo acting on granular sizes and time scales.

  17. Under the Lens: Investigating the Sun's Mysteries

    Science.gov (United States)

    Harwood, William; Klotz, Irene

    2008-11-01

    Sometime around 2012, the waxing 11-year solar cycle once again will reach its peak. Between now and then, magnetically turbulent sunspots, spawned by some still mysterious process, will form near the poles in increasing numbers and migrate toward the Sun's faster-rotating equator in pairs of opposite polarity. Titanic magnetic storms will rage as immense flux tubes rise to the surface in active regions around sunspots and spread out in a boiling sea of electric charge. Magnetic field lines across an enormous range of scales will arc and undulate, rip apart and reconnect, heating the Sun's upper atmosphere and occasionally triggering brilliant flares and multibillion-megaton coronal mass ejections (CMEs) that travel through the solar wind and slam into Earth.

  18. Wreathes of Magnetism in Rapidly Rotating Suns

    CERN Document Server

    Brown, Benjamin P; Brun, Allan Sacha; Toomre, Juri

    2009-01-01

    When our Sun was young it rotated much more rapidly than now. Observations of young, rapidly rotating stars indicate that many possess substantial magnetic activity and strong axisymmetric magnetic fields. We conduct simulations of dynamo action in rapidly rotating suns with the 3-D MHD anelastic spherical harmonic (ASH) code to explore the complex coupling between rotation, convection and magnetism. Here we study dynamo action realized in the bulk of the convection zone for two systems, rotating at three and five times the current solar rate. We find that substantial organized global-scale magnetic fields are achieved by dynamo action in these systems. Striking wreathes of magnetism are built in the midst of the convection zone, coexisting with the turbulent convection. This is a great surprise, for many solar dynamo theories have suggested that a tachocline of penetration and shear at the base of the convection zone is a crucial ingredient for organized dynamo action, whereas these simulations do not includ...

  19. How plants LINC the SUN to KASH.

    Science.gov (United States)

    Zhou, Xiao; Meier, Iris

    2013-01-01

    Linkers of the nucleoskeleton to the cytoskeleton (LINC) complexes formed by SUN and KASH proteins are conserved eukaryotic protein complexes that bridge the nuclear envelope (NE) via protein-protein interactions in the NE lumen. Revealed by opisthokont studies, LINC complexes are key players in multiple cellular processes, such as nuclear and chromosomal positioning and nuclear shape determination, which in turn influence the generation of gametes and several aspects of development. Although comparable processes have long been known in plants, the first plant nuclear envelope bridging complexes were only recently identified. WPP domain-interacting proteins at the outer NE have little homology to known opisthokont KASH proteins, but form complexes with SUN proteins at the inner NE that have plant-specific properties and functions. In this review, we will address the importance of LINC complex-regulated processes, describe the plant NE bridging complexes and compare them to opisthokont LINC complexes.

  20. International Sun-Earth Explorer (ISEE)

    Science.gov (United States)

    Murdin, P.

    2000-11-01

    Series of three US satellites designed to study the solar wind and its interaction with the Earth's magnetosphere. ISEE-1 and 2 were placed into highly elliptical Earth orbits. ISEE-3 was placed in a halo orbit at the L1 Lagrangian point between the Sun and Earth. It gave advance warning of solar storms heading towards Earth. (See also INTERNATIONAL COMETARY EXPLORER and EXPLORER.)...

  1. Operational Art and the Rising Sun

    Science.gov (United States)

    1994-05-16

    shall run wild for the first six months or a year, but I have utterly no confidence for the second or third ’Potter, p. 46; Michael Slackman, Target...attack that no american carriers in 26Joseph K. Taussig , "A Tactical View of Pearl Harbor", Paul Stillwell, ed., Air Raid: Pearl Harbor! (Annapolis, MD...Weiner, 1991. Slackman, Michael . Target: Pearl Harbor. Honolulu: University of Hawaii Press, 1990. Stephan, John J. Hawaii Under the Rising Sun

  2. Complete Solution of Sun Tracking for Heliostat

    Institute of Scientific and Technical Information of China (English)

    CHEN Ying-Tian; LIM Boon-Han; LIM Chern-Sing

    2006-01-01

    A general solution of sun tracking for an arbitrarily oriented heliostat towards an arbitrarily located target on the earth is published. With the most general form of solar tracking formulae, it is seen that the used azimuthelevation, spinning-elevation tracking formulae etc. are the special cases of it. The possibilities of utilizing the general solution and its significance in solar energy engineering are discussed.

  3. Complete Solution of Sun Tracking for Heliostat

    Science.gov (United States)

    Chen, Ying-Tian; Lim, Boon-Han; Lim, Chern-Sing

    2006-01-01

    A general solution of sun tracking for an arbitrarily oriented heliostat towards an arbitrarily located target on the earth is published. With the most general form of solar tracking formulae, it is seen that the used azimuth-elevation, spinning-elevation tracking formulae etc. are the special cases of it. The possibilities of utilizing the general solution and its significance in solar energy engineering are discussed.

  4. Sun protection factor persistence during a day with physical activity and bathing

    DEFF Research Database (Denmark)

    Bodekaer, M.; Faurschou, A.; Philipsen, P.A.

    2008-01-01

    application. The minimal erythema dose (MED) was determined 24 h after irradiation. The sun protection factor (SPF) was calculated, as MED on protected skin/MED on unprotected skin. RESULTS: The SPFs of the inorganic and organic sunscreen, respectively, were reduced by 38% and 41% after 4 h and by 55% and 58...

  5. Hot water from the sun: a consumer guide to solar water heating

    Energy Technology Data Exchange (ETDEWEB)

    McPherson, Beth

    2005-02-15

    The following topics are discussed: how solar water heaters work, making good use of the sun, estimating costs and savings, choosing the right dealer/installer, choosing the right system, warranties and contracts, getting a good installation, and living with your solar energy system. The appendices discuss system performance and durability, and provide sources of additional information on solar energy and its applications. (MHR)

  6. Outdoor Workers' Use of Sun Protection at Work and Leisure

    Directory of Open Access Journals (Sweden)

    Cheryl E. Peters

    2016-09-01

    Conclusion: This high-participation rate cohort helps characterize sun protection behaviors among outdoor workers. Workers practiced better sun protection at work than on weekends, suggesting that workplace policies supportive of sun protection could be useful for skin cancer prevention in the construction industry.

  7. Design and Fabrication of an Albedo Insensitive Analog Sun Sensor

    NARCIS (Netherlands)

    Wu, H.; Emadi, A.; De Graaf, G.; Leijtens, J.; Wolffenbuttel, R.F.

    2011-01-01

    A sun sensor is usually included in a satellite for optically measuring the position relative to the sun. The accuracy of a conventional sun sensor is affected by reflected sunlight at the nearby earth atmosphere: the albedo radiation. The part of the spectrum at near IR (1.5 μm) is not included in

  8. Exploring Young People's Beliefs and Images about Sun Safety

    Science.gov (United States)

    White, K. M.; Robinson, N. G.; Young, R. McD.; Anderson, P. J.; Hyde, M. K.; Greenbank, S.; Keane, J.; Rolfe, T.; Vardon, P.; Baskerville, D.

    2008-01-01

    To understand young people's low levels of sun protection behaviour, 145 young people (aged 12 to 20 years) were recruited from Queensland, to participate in a one-hour focus group where they discussed issues related to sun protection and images of tanned and non-tanned people. Responses were content analysed to identify common sun protection…

  9. Maximizing Output Power of a Solar Panel via Combination of Sun Tracking and Maximum Power Point Tracking by Fuzzy Controllers

    OpenAIRE

    Mohsen Taherbaneh; A. H. Rezaie; H. Ghafoorifard; Rahimi, K; M. B. Menhaj

    2010-01-01

    In applications with low-energy conversion efficiency, maximizing the output power improves the efficiency. The maximum output power of a solar panel depends on the environmental conditions and load profile. In this paper, a method based on simultaneous use of two fuzzy controllers is developed in order to maximize the generated output power of a solar panel in a photovoltaic system: fuzzy-based sun tracking and maximum power point tracking. The sun tracking is performed by changing the solar...

  10. Keeping Cool Close to the Sun

    Energy Technology Data Exchange (ETDEWEB)

    Hazi, A

    2006-01-13

    The germanium detector in the gamma-ray spectrometer (GRS) aboard the MESSENGER spacecraft is only the size and weight of a can of peaches but will play a critical role in investigating Mercury, the planet closest to the Sun. The MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging) spacecraft travels at about 38 kilometers per second and is named after the scientific goals of the mission. It is the first spacecraft to visit Mercury since 1975. MESSENGER must take an oblique route to approach Mercury so that it does not fly past the planet and fall directly into the Sun. The spacecraft will travel 7.9 billion kilometers, flying by Earth once, Venus twice, and Mercury three times before settling into orbit around this mysterious planet. Of all the terrestrial planets, which include Venus, Earth, and Mars, Mercury is the smallest and the densest; its days are 176 Earth days long, two complete orbits of the planet around the Sun. Temperatures range from a high of 450 C on the Sun side during its long day to a low of -185 C on its night side. By studying this extreme planet, scientists hope to better understand how Earth formed and evolved. The GRS, one of the seven lightweight scientific instruments on MESSENGER, will be used to help scientists determine the abundance of elements in Mercury's crust, including the materials that might be ice at its poles. Livermore engineer Norman Madden led the West Coast team effort to design and build the GRS in a collaboration led by Johns Hopkins University Applied Physics Laboratory (JHUAPL). The team included Lawrence Berkeley and Lawrence Livermore national laboratories as well as University of California at Berkeley (UCB) Space Sciences Laboratory (SSL). The JHUAPL MESSENGER project is a National Aeronautics and Space Administration (NASA) Discovery Mission. Because the detector needs to operate at very low temperatures and MESSENGER is close to the Sun, the thermal design to protect the detector was

  11. Watching the Sun to Improve Exoplanet Detection

    Science.gov (United States)

    Kohler, Susanna

    2015-12-01

    Looking for stars that wobble is one of the key ways by which we detect exoplanets: the gravitational pull of planets cause tiny variations in stars radial velocities. But our ability to detect Earth twins is currently limited by our ability to distinguish between radial-velocity variations caused by exoplanets, and those caused by noise from the star itself. A team of scientists has recently proposed that the key to solving this problem may be to examine our own star.Precision Amid NoiseThe radial-velocity technique works well for detecting large planets on close orbits, but detecting an Earth twin requires being able to detect star motion on the order of 10 cm/s! This precision is hard to reach, because activity on the stellar surface i.e., sunspots, plages (bright spots), or granulation can also cause variations in the measured radial velocity for the star, obscuring the signature of a planet.Because the stars were examining arent resolved, we cant track the activity on their surfaces so how can we better understand the imprint that stellar activity has on radial-velocity measurements? A team of scientists has come up with a clever approach: examine the Sun as though it were a distant star.Wealth of InformationThe team, led by Xavier Dumusque (Branco-Weiss Fellow at the Harvard-Smithsonian Center for Astrophysics) and David F. Phillips (Harvard-Smithsonian Center for Astrophysics), has begun a project to observe the Sun with a ground-based solar telescope. The telescope observes the full disk of the Sun and feeds the data into the HARPS-N spectrograph in Spain, a spectrograph normally used for radial-velocity measurements of other stars in the hunt for exoplanets.But the team has access to other data about the Sun, too: information from satellites like the Solar Dynamics Observatory and SORCE about the solar activity and total irradiance during the time when the spectra were taken. Dumusque and collaborators have combined all of this information, during a week

  12. The Sun: the Earth light source

    Science.gov (United States)

    Berrilli, Francesco; Giovannelli, Luca; Del Moro, Dario; Piazzesi, Roberto; Catena, Liu` Maria; Amicucci, Giordano; Vittorio, Nicola

    2015-04-01

    We have implemented at Department of Physics of University of Rome Tor Vergata a project called "The Sun: the Earth light source". The project obtained the official endorsement from the IAU Executive Committee Working Group for the International Year of Light. The project, specifically designed for high school students, is focused on the "scientific" study of Sun light by means of a complete acquisition system based on "on the shelf" appropriately CMOS low-cost sensor with free control s/w and self-assembled telescopes. The project (hereafter stage) plan is based on a course of two weeks (60 hours in total). The course contains 20 hours of theoretical lectures, necessary to learn basics about Sun, optics, telescopes and image sensors, and 40 hours of laboratory. During the course, scientists and astronomers share with high schools students, work activities in real research laboratories. High schools teachers are intensely involved in the project. Their role is to share activities with university teachers and realize outreach actions in the home institutions. Simultaneously, they are introduced to innovative teaching methods and the project in this way is regarded as a professional development course. Sun light analysis and Sun-Earth connection through light are the main scientific topics of this project. The laboratory section of the stage is executed in two phases (weeks): First phase aims are the realization of a keplerian telescope and low-cost acquisition system. During this week students are introduced to astronomical techniques used to safety collect and acquire solar light; Second phase aims is the realization of a low-cost instrument to analyse sunlight extracting information about the solar spectrum, solar irradiance and Sun-Earth connection. The proposed stage has been already tested in Italy reached the fifth edition in 2014. Since 2010, the project has been a cornerstone outreach program of the University of Rome Tor Vergata, the Italian Ministry of

  13. Monitoring Holes in the Sun's Corona

    Science.gov (United States)

    Kohler, Susanna

    2016-09-01

    Coronal holes are where the fast solar wind streams out of the Suns atmosphere, sending charged particles on rapid trajectories out into the solar system. A new study examines how the distribution of coronal holes has changed over the last 40 years.Coronal holes form where magnetic field lines open into space (B) instead of looping back to the solar surface (A). [Sebman81]Source of the Fast Solar WindAs a part of the Suns natural activity cycle, extremely low-density regions sometimes form in the solar corona. These coronal holes manifest themselves as dark patches in X-ray and extreme ultraviolet imaging, since the corona is much hotter than the solar surface that peeks through from underneath it.Coronal holes form when magnetic field lines open into space instead of looping back to the solar surface. In these regions, the solar atmosphere escapes via these field lines, rapidly streaming away from the Suns surface in whats known as the fast solar wind.Coronal Holes Over Space and TimeAutomated detection of coronal holes from image-based analysis is notoriously difficult. Recently, a team of scientists led by Kenichi Fujiki (ISEE, Nagoya University, Japan) has developed an automated prediction technique for coronal holes that relies instead on magnetic-field data for the Sun, obtained at the National Solar Observatorys Kitt Peak between 1975 and 2014. The team used these data to produce a database of 3335 coronal hole predictions over nearly 40 years.Latitude distribution of 2870 coronal holes (each marked by an x; color indicates polarity), overlaid on the magnetic butterfly map of the Sun. The low-latitude coronal holes display a similar butterfly pattern, in which they move closer to the equator over the course of the solar cycle. Polar coronal holes are more frequent during solar minima. [Fujiki et al. 2016]Examining trends in the coronal holes distribution in latitude and time, Fujiki and collaborators find a strong correlation between the total area covered

  14. Sun protecting and sun exposing behaviors: testing their relationship simultaneously with indicators of ultraviolet exposure among adolescents.

    Science.gov (United States)

    Williams, Melinda; Caputi, Peter; Jones, Sandra C; Iverson, Don

    2011-01-01

    The aim of this study was to build on existing understanding of adolescent sun-related behavior by combining sun protecting and sun exposing behaviors and testing their relationship simultaneously with indicators of ultraviolet (UV) exposure. Data were collected for 692 adolescents aged between 12 and 18 years. General linear modeling was undertaken to test the relationship of sun-related behaviors with indicators of UV exposure. Overall, the combined sun protection and sun exposing behaviors accounted for 13.8% of the variance in the number of sunburns, 28.1% of the variance in current tan and 57.5% of the variance in desired tan, respectively. Results indicated that having a strong desire for a tan was significantly associated with spending time tanning, delaying the use of sun protection, wearing brief clothing and using no sun protection; whereas the number of sunburns was significantly associated with sunscreen use, avoiding peak hours and delaying sun protection. Current tan was significantly associated with wearing sunglasses, shade use and time spent tanning. In examining sun-related behaviors among adolescents, consideration needs to be given to both sun exposing and sun protecting behaviors. This research has important implications for conceptualizing outcomes in programs designed to reduce UV exposure.

  15. Sun-care product advertising in parenting magazines: what information does it provide about sun protection?

    Science.gov (United States)

    Kang, Hannah; Walsh-Childers, Kim

    2014-01-01

    This study analyzed the content of sun-care product advertisements in five major U.S. parenting magazines with high circulation: Family Circle, Parents, Family Fun, Parenting (Early Years), and Parenting (School Years). The study examined what information sun-care product advertisements tell parents about skin cancer prevention and about sunscreen use for themselves or for their children based on the Health Belief Model concepts of perceived benefits and perceived barriers. Results showed that the most commonly mentioned benefit of the product was that it blocks ultraviolet A (UVA) and ultraviolet B (UVB) rays. One-third of the ads promoted the product's effectiveness in overcoming four of the barriers that prevent people from using sunscreens: eye irritation, skin irritation, an unpleasant smell, and the need to reapply sunscreen too often or after physical activity. However, only a few of the ads provided information about the consequences of unprotected sun exposure or mentioned methods of sun protection or skin cancer prevention other than sunscreen use. We discuss the implications of these messages for parents' ability to understand correctly how to protect their children from damaging sun exposure.

  16. [Research on absolute calibration of sun channel of sun photometer using laser raster scanning method].

    Science.gov (United States)

    Xu, Wen-Bin; Li, Jian-Jun; Zheng, Xiao-Bing

    2013-01-01

    In the present paper, a new calibration method of absolute spectral irradiance responsivity of sun channel of sun photometer was developed. A tunable laser was used as source and a standard tranfer detector, calibrated against cryogenic absolute radiometer, was used to measure laser beam power. By raster scanning of a single collimated laser beam to generate the uniform irradiance field at the plane of effective aperture stop of sun photometer, the absolute irradiance responsivity of center wavelength of the 870 nm unpolarized sun channels of sun photometer was obtained accurately. The relative spectral irradiance responsivity of corresponding channel was obtained by using lamp-monochromator system and then used to acquire the absolute spectral irradiance responsivity in the laboratory. On the basis of the above results, the top-of-the-atmosphere responsive constant V0 was obtained by integration with extraterrestrial solar spectral irradiance data. Comparing the calibration result with that from GSFC, NASA in 2009, the difference is only 3.75%. In the last, the uncertainties of calibration were evaluated and reached to 2.06%. The principle feasibility of the new method was validated.

  17. Design and Manufacturing of a High-Precision Sun Tracking System Based on Image Processing

    Directory of Open Access Journals (Sweden)

    Kianoosh Azizi

    2013-01-01

    Full Text Available Concentration solar arrays require greater solar tracking precision than conventional photovoltaic arrays. This paper presents a high precision low cost dual axis sun tracking system based on image processing for concentration photovoltaic applications. An imaging device is designed according to the principle of pinhole imaging, making sun rays to be received on a screen through pinhole and to be a sun spot. The location of the spot is used to adjust the orientation of the solar panel. A fuzzy logic controller is developed to achieve this goal. A prototype was built, and experimental results have proven the good performance of the proposed system and low error of tracking. The operation of this system is independent of geographical location, initial calibration, and periodical regulations.

  18. Thermal and orbital analysis of Earth monitoring Sun-synchronous space experiments

    Science.gov (United States)

    Killough, Brian D.

    1990-01-01

    The fundamentals of an Earth monitoring Sun-synchronous orbit are presented. A Sun-synchronous Orbit Analysis Program (SOAP) was developed to calculate orbital parameters for an entire year. The output from this program provides the required input data for the TRASYS thermal radiation computer code, which in turn computes the infrared, solar and Earth albedo heat fluxes incident on a space experiment. Direct incident heat fluxes can be used as input to a generalized thermal analyzer program to size radiators and predict instrument operating temperatures. The SOAP computer code and its application to the thermal analysis methodology presented, should prove useful to the thermal engineer during the design phases of Earth monitoring Sun-synchronous space experiments.

  19. Frequency shifts of resonant modes of the Sun due to near-surface convective scattering

    CERN Document Server

    Bhattacharya, Jishnu; Antia, H M

    2015-01-01

    Measurements of oscillation frequencies of the Sun and stars can provide important independent constraints on their internal structure and dynamics. Seismic models of these oscillations are used to connect structure and rotation of the star to its resonant frequencies, which are then compared with observations, the goal being that of minimizing the difference between the two. Even in the case of the Sun, for which structure models are highly tuned, observed frequencies show systematic deviations from modeled frequencies, a phenomenon referred to as the "surface term." The dominant source of this systematic effect is thought to be vigorous near-surface convection, which is not well accounted for in both stellar modeling and mode-oscillation physics. Here we bring to bear the method of homogenization, applicable in the asymptotic limit of large wavelengths (in comparison to the correlation scale of convection), to characterize the effect of small-scale surface convection on resonant-mode frequencies in the Sun....

  20. Effects of motives on reactions to safe sun messages.

    Science.gov (United States)

    Aspden, Trefor; Ingledew, David K; Parkinson, John A

    2015-01-01

    We investigated whether appearance motive for sun exposure, which strongly predicts exposure behaviour, would predict reactions to safe sun messages. In a survey with an embedded experiment, 245 individuals completed measures of motives, read a safe sun message framed by incentive (appearance/health), tone (directive/nondirective) and valence (gain/loss), then completed measures of reactions. For participants high in appearance motive, an appearance-nondirective message was most persuasive. Regardless of individual's appearance motive, appearance messages produced lower reactance if phrased using nondirective language. To maximise persuasion and minimise reactance in individuals most motivated to sun expose, safe sun messages should focus on appearance using nondirective language.

  1. The Sun's interior structure and dynamics, and the solar cycle

    CERN Document Server

    Broomhall, A -M; Howe, R; Norton, A A; Thompson, M J

    2014-01-01

    The Sun's internal structure and dynamics can be studied with helioseismology, which uses the Sun's natural acoustic oscillations to build up a profile of the solar interior. We discuss how solar acoustic oscillations are affected by the Sun's magnetic field. Careful observations of these effects can be inverted to determine the variations in the structure and dynamics of the Sun's interior as the solar cycle progresses. Observed variations in the structure and dynamics can then be used to inform models of the solar dynamo, which are crucial to our understanding of how the Sun's magnetic field is generated and maintained.

  2. A highly accurate wireless digital sun sensor based on profile detecting and detector multiplexing technologies

    Science.gov (United States)

    Wei, Minsong; Xing, Fei; You, Zheng

    2017-01-01

    The advancing growth of micro- and nano-satellites requires miniaturized sun sensors which could be conveniently applied in the attitude determination subsystem. In this work, a profile detecting technology based high accurate wireless digital sun sensor was proposed, which could transform a two-dimensional image into two-linear profile output so that it can realize a high update rate under a very low power consumption. A multiple spots recovery approach with an asymmetric mask pattern design principle was introduced to fit the multiplexing image detector method for accuracy improvement of the sun sensor within a large Field of View (FOV). A FOV determination principle based on the concept of FOV region was also proposed to facilitate both sub-FOV analysis and the whole FOV determination. A RF MCU, together with solar cells, was utilized to achieve the wireless and self-powered functionality. The prototype of the sun sensor is approximately 10 times lower in size and weight compared with the conventional digital sun sensor (DSS). Test results indicated that the accuracy of the prototype was 0.01° within a cone FOV of 100°. Such an autonomous DSS could be equipped flexibly on a micro- or nano-satellite, especially for highly accurate remote sensing applications.

  3. Improving the Efficacy of Appearance-Based Sun Exposure Interventions with the Terror Management Health Model

    Science.gov (United States)

    Morris, Kasey Lynn; Cooper, Douglas P.; Goldenberg, Jamie L.; Arndt, Jamie; Gibbons, Frederick X.

    2014-01-01

    The terror management health model (TMHM) suggests that when thoughts of death are accessible people become increasingly motivated to bolster their self-esteem relative to their health, because doing so offers psychological protection against mortality concerns. Two studies examined sun protection intentions as a function of mortality reminders and an appearance-based intervention. In Study 1, participants given a sun protection message that primed mortality and shown a UV-filtered photo of their face reported greater intentions to use sun protection on their face, and took more sunscreen samples than participants shown a regular photo of their face. In Study 2, reminders of mortality increased participants’ intentions to use facial sun protection when the UV photo was specifically framed as revealing appearance consequences of tanning, compared to when the photo was framed as revealing health consequences, or when no photo was shown. These findings extend the terror management health model, and provide preliminary evidence that appearance-based tanning interventions have a greater influence on sun protection intentions under conditions that prime thoughts of death. We discuss implications of the findings, and highlight the need for additional research examining the applicability to long-term tanning behavior. PMID:24811049

  4. A microfabricated sun sensor using GaN-on-sapphire ultraviolet photodetector arrays

    Science.gov (United States)

    Miller, Ruth A.; So, Hongyun; Chiamori, Heather C.; Suria, Ateeq J.; Chapin, Caitlin A.; Senesky, Debbie G.

    2016-09-01

    A miniature sensor for detecting the orientation of incident ultraviolet light was microfabricated using gallium nitride (GaN)-on-sapphire substrates and semi-transparent interdigitated gold electrodes for sun sensing applications. The individual metal-semiconductor-metal photodetector elements were shown to have a stable and repeatable response with a high sensitivity (photocurrent-to-dark current ratio (PDCR) = 2.4 at -1 V bias) and a high responsivity (3200 A/W at -1 V bias) under ultraviolet (365 nm) illumination. The 3 × 3 GaN-on-sapphire ultraviolet photodetector array was integrated with a gold aperture to realize a miniature sun sensor (1.35 mm × 1.35 mm) capable of determining incident light angles with a ±45° field of view. Using a simple comparative figure of merit algorithm, measurement of incident light angles of 0° and 45° was quantitatively and qualitatively (visually) demonstrated by the sun sensor, supporting the use of GaN-based sun sensors for orientation, navigation, and tracking of the sun within the harsh environment of space.

  5. The Apsidal Precession for Low Earth Sun Synchronized Orbits

    Directory of Open Access Journals (Sweden)

    Shkelzen Cakaj

    2015-09-01

    Full Text Available By nodal regression and apsidal precession, the Earth flattering at satellite low Earth orbits (LEO is manifested. Nodal regression refers to the shift of the orbit’s line of nodes over time as Earth revolves around the Sun. Nodal regression is orbit feature utilized for circular orbits to be Sun synchronized. A sun¬-synchronized orbit lies in a plane that maintains a fixed angle with respect to the Earth-Sun direction. In the low Earth Sun synchronized circular orbits are suited the satellites that accomplish their photo imagery missions. Nodal regression depends on orbital altitude and orbital inclination angle. For the respective orbital altitudes the inclination window for the Sun synchronization to be attained is determined. The apsidal precession represents major axis shift, respectively the argument of perigee deviation. The apsidal precession simulation, for inclination window of sun synchronized orbital altitudes, is provided through this paper.

  6. Sun exposure and protection behavior of Danish farm children

    DEFF Research Database (Denmark)

    Bodekær, Mette; Øager Petersen, Bibi; Philipsen, Peter Alshede

    2014-01-01

    Healthy sun habits acquired in childhood could reduce skin cancer incidence. We examined the sun exposure and protection behavior of an expected high-exposure group of children, and the association to their parents. Open, prospective cohort study. One hundred and thirty nine participants (40...... families) kept daily sun behavior diaries (sun exposure, sunscreen use, sunburns) over a 4-month summer period (15,985 diary days). The Pigment Protection Factor (PPF), an objective measure of sun exposure, was measured at two body sites, before and after summer. All participants presented data from...... the same 115 days. Risk behavior (sun exposure of upper body) took place on 9.5 days (boys) and 15.6 days (girls). Sunburn and sunscreen use were infrequent. Boys' sun exposure resulted in an increased photo protection over the study period of 1.7 SED (upper arm) and 0.8 SED (shoulder) to elicit erythema...

  7. Grand Challenges in the Physics of the Sun and Sun-like Stars

    CERN Document Server

    Thompson, Michael J

    2014-01-01

    The study of stellar structure and evolution is one of the main building blocks of astrophysics, and the Sun has an importance both as the star that is most amenable to detailed study and as the star that has by far the biggest impact on the Earth and near-Earth environment through its radiative and particulate outputs. Over the past decades, studies of stars and of the Sun have become somewhat separate. But in recent years, the rapid advances in asteroseismology, as well as the quest to better understand solar and stellar dynamos, have emphasized once again the synergy between studies of the stars and the Sun. In this article I have selected two "grand challenges" both for their crucial importance and because I thnk that these two problems are tractable to significant progress in the next decade. They are (i) understanding how solar and stellar dynamos generate magnetic field, and (ii) improving the predictability of geo-effective space weather.

  8. Carousel Trackers with 1-Sun or 3-Sun Modules for Commercial Building Rooftops

    Energy Technology Data Exchange (ETDEWEB)

    Gehl, Anthony C [ORNL; Maxey, L Curt [ORNL; Fraas, Dr. Lewis [JX Crystals, Inc.; Avery, James E. [JX Crystals, Inc.; Minkin, Leonid M [ORNL; Huang, H, [JX Crystals, Inc.

    2008-01-01

    The goal is lower cost solar electricity. Herein, two evolutional steps are described toward achieving this goal. The first step is to follow the sun with a solar tracker. Herein, a carousel tracker is described for mounting on commercial building flat rooftops in order to produce more kWh per kW relative to fixed PV modules. The second evolutionary improvement is to produce lower cost 3-sun CPV modules where two thirds of the expensive single crystal silicon material is replaced by less expensive mirror material. This paper describes the performance and durability of two prototype installations demonstrating these evolutionary innovations. In the first case, the installation and operation of 2 carousels equipped with traditional flat plate modules is described. In the second case, the operation of a carousel equipped with new 3-sun CPV modules is described. Both systems have been operating as expected for several months through the winter of 2007.

  9. Performance of 3-Sun Mirror Modules on Sun Tracking Carousels on Flat Roof Buildings

    Energy Technology Data Exchange (ETDEWEB)

    Fraas, Dr. Lewis [JX Crystals, Inc.; Avery, James E. [JX Crystals, Inc.; Minkin, Leonid M [ORNL; Maxey, L Curt [ORNL; Gehl, Anthony C [ORNL; Hurt, Rick A [ORNL; Boehm, Robert F [ORNL

    2008-01-01

    Commercial buildings represent a near term market for cost competitive solar electric power provided installation costs and solar photovoltaic module costs can be reduced. JX Crystals has developed a carousel sun tracker that is prefabricated and can easily be deployed on building flat roof tops without roof penetration. JX Crystals is also developing 3-sun PV mirror modules where less expensive mirrors are substituted for two-thirds of the expensive single crystal silicon solar cell surface area. Carousels each with four 3-sun modules have been set up at two sites, specifically at Oak Ridge National Lab and at the University of Nevada in Las Vegas. The test results for these systems are presented.

  10. Performance of 3-sun mirror modules on sun tracking carousels on flat roof buildings

    Science.gov (United States)

    Fraas, Lewis; Avery, James; Minkin, Leonid; Maxey, Curt; Gehl, Tony; Hurt, Rick; Boehm, Robert

    2008-08-01

    Commercial buildings represent a near term market for cost competitive solar electric power provided installation costs and solar photovoltaic module costs can be reduced. JX Crystals has developed a carousel sun tracker that is prefabricated and can easily be deployed on building flat roof tops without roof penetration. JX Crystals is also developing 3-sun PV mirror modules where less expensive mirrors are substituted for two-thirds of the expensive single crystal silicon solar cell surface area. Carousels each with four 3-sun modules have been set up at two sites, specifically at Oak Ridge National Lab and at the University of Nevada in Las Vegas. The test results for these systems are presented.

  11. Autonomous Sun-Direction Estimation Using Partially Underdetermined Coarse Sun Sensor Configurations

    Science.gov (United States)

    O'Keefe, Stephen A.

    In recent years there has been a significant increase in interest in smaller satellites as lower cost alternatives to traditional satellites, particularly with the rise in popularity of the CubeSat. Due to stringent mass, size, and often budget constraints, these small satellites rely on making the most of inexpensive hardware components and sensors, such as coarse sun sensors (CSS) and magnetometers. More expensive high-accuracy sun sensors often combine multiple measurements, and use specialized electronics, to deterministically solve for the direction of the Sun. Alternatively, cosine-type CSS output a voltage relative to the input light and are attractive due to their very low cost, simplicity to manufacture, small size, and minimal power consumption. This research investigates using coarse sun sensors for performing robust attitude estimation in order to point a spacecraft at the Sun after deployment from a launch vehicle, or following a system fault. As an alternative to using a large number of sensors, this thesis explores sun-direction estimation techniques with low computational costs that function well with underdetermined sets of CSS. Single-point estimators are coupled with simultaneous nonlinear control to achieve sun-pointing within a small percentage of a single orbit despite the partially underdetermined nature of the sensor suite. Leveraging an extensive analysis of the sensor models involved, sequential filtering techniques are shown to be capable of estimating the sun-direction to within a few degrees, with no a priori attitude information and using only CSS, despite the significant noise and biases present in the system. Detailed numerical simulations are used to compare and contrast the performance of the five different estimation techniques, with and without rate gyro measurements, their sensitivity to rate gyro accuracy, and their computation time. One of the key concerns with reducing the number of CSS is sensor degradation and failure. In

  12. Magnetic Patches in Internetwork Quiet Sun

    Science.gov (United States)

    De Wijn, Alfred; Lites, B.; Berger, T.; Shine, R.; Title, A.; Katsukawa, Y.; Tsuneta, S.; Suematsu, Y.; Shimizu, T.; Hinode Team

    2007-05-01

    We study strong flux elements in the quiet sun in the context of the nature of quiet-sun magnetism, its coupling to chromospheric, transition-region and coronal fields, and the nature of a local turbulent dynamo. Strong, kilogauss flux elements show up intermittently as small bright points in G-band and Ca II H images. Although bright points have been extensively studied in the magnetic network, internetwork magnetism has only come under scrutiny in recent years. A full spectrum of field strengths seems to be ubiquitously present in the internetwork at small spatial scales, with the stronger elements residing in intergranular lanes. De Wijn et al. (2005) found that bright points in quiet sun internetwork areas appear recurrently with varying intensity and horizontal motion within long-lived patches that outline cell patterns on mesogranular scales. They estimate that the "magnetic patches" have a mean lifetime of nine hours, much longer than granular timescales. We use multi-hour sequences of G-band and Ca II H images as well as magnetograms recorded by the Hinode satellite to follow up on their results. The larger field of view, the longer sequences, the addition of magnetograms, and the absence of atmospheric seeing allows us to better constrain the patch lifetime, to provide much improved statistics on IBP lifetime, to compare IBPs to network bright points, and to study field polarity of IBPs in patches and between nearby patches. Hinode is an international project supported by JAXA, NASA, PPARC and ESA. We are grateful to the Hinode team for all their efforts in the design, build and operation of the mission.

  13. Recursively arbitrarily vertex-decomposable suns

    Directory of Open Access Journals (Sweden)

    Olivier Baudon

    2011-01-01

    Full Text Available A graph \\(G = (V,E\\ is arbitrarily vertex decomposable if for any sequence \\(\\tau\\ of positive integers adding up to \\(|V|\\, there is a sequence of vertex-disjoint subsets of \\(V\\ whose orders are given by \\(\\tau\\, and which induce connected graphs. The aim of this paper is to study the recursive version of this problem on a special class of graphs called suns. This paper is a complement of [O. Baudon, F. Gilbert, M. Woźniak, Recursively arbitrarily vertex-decomposable graphs, research report, 2010].

  14. The radiation belt of the Sun

    CERN Document Server

    Gruzinov, Andrei

    2013-01-01

    For a given solar magnetic field, the near-Sun (phase-space) density of cosmic ray electrons and positrons of energy above about 10GeV can be calculated from first principles, without any assumptions about the cosmic ray diffusion. This is because the sunlight Compton drag must be more important than diffusion. If the solar magnetic field has an appreciable dipole component, the electron/positron density should have a belt-like dent, perhaps extending to several solar radii. The belt structure appears because the quasi-bound orbits are depopulated by the sunlight Compton drag.

  15. Search for Neutrinos from the Sun

    Science.gov (United States)

    Davis, Raymond Jr.

    1968-09-01

    A solar neutrino detection system has been built to observe the neutrino radiation from the sun. The detector uses 3,900,000 liters of tetrachloroethylene as the neutrino capturing medium. Argon is removed from the liquid by sweeping with helium gas, and counted in a small low level proportional counter. The recovery efficiency of the system was tested with Ar{sup 36} by the isotope dilution method, and also with Ar{sup 37} produced in the liquid by fast neutrons. These tests demonstrate that Ar{sup 37} produced in the liquid by neutrino capture can be removed with a 95 percent efficiency by the procedure used.

  16. Dual Axis Light Sensor for Tracking Sun

    Science.gov (United States)

    Shibata, Miki; Tambo, Toyokazu

    We have developed convenient light sensors to control a platform of solar cell panel. Dual axis light sensor in the present paper has structure of 5 PD (photodiode) light sensor which is composed of 5 photodiodes attached on a frustum of pyramid(1). Light source can be captured in front of the sensor by rotating the X and Y axis as decreasing the output deviation between two pairs of outside photodiodes. We here report the mechanism of sun tacking using the dual axis 5 PD light sensor and the fundamental results performed in the dark room.

  17. Hinode, the Sun, and public outreach

    Science.gov (United States)

    Yaji, K.; Tonooka, H.; Shimojo, M.; Tokimasa, N.; Suzuki, D.; Nakamichi, A.; Shimoikura, I.

    2015-03-01

    Extended Abstract Hinode is a solar observation satellite in Japan and its launch was in September 2006. Its name means ``SUNRISE`` in Japanese. It has three instruments onboard in visible light, X-ray, EUV to solve mystery of coronal heating and origins of magnetic fields. Hinode has been providing us with impressive solar data, which are very important for not only investigating solar phenomena but also giving new knowledge about the sun to the public. In order to efficiently communicate Hinode data to the public, we organized working group for public use of Hinode data. which are composed of both researchers and educators in collaboration. As follow, we introduce our activities in brief. For the public use of Hinode data, at first, we produced two DVDs introducing Hinode observation results. In particular, second DVD contains a movie for kids, which are devloped to picturebook. Now, it is under producing an illustrated book and a planetarium program. It turn out that the DVDs help the public understand the sun from questionnaire surveys. Second, we developed teaching materials from Hinode data and had a science classroom about the sun, solar observations, practice with PC such as imaging software at junior high school. As the results, they had much interests in Hinode data. Third, we have joint observations with high school students and so on in a few years. The students compare their own data with Hinode data and have a presentation at science contests. The joint observations make their motivation higher in their activities. It is important to record and report our activities in some ways. So, we positively publish papers and have presentions in domestic/international meetings. Though we are supported in budget, resources and so on by NAOJ Hinode Team, we apply research funds for promoting our EPO activities and acquire some funds such as NAOJ Joint Research Expenses and Grands-Aid for Scientific Research Funds since the launch. This way, since its launch, we

  18. Selective factors in sun-weather research

    Science.gov (United States)

    Taylor, H. A., Jr.

    1986-01-01

    Research on the correlations between solar wind/IMF disturbances and subsequent winter troposphere vorticity changes (denoted SV) are reviewed to investigate sun-weather relationships. Uncertainties in the research attempting to link short-term solar variations and associated changes in the lower atmosphere are discussed, and it is noted that such analyses have generally not addressed either the choice of parameters or the selective factors involved in the physical relationships existing between parameters. It is suggested that the identification of a viable mechanism scenario would require a detailed multiparameter selective factor analysis, extending to the investigation of the atmospheric data as well as the solar wind/IMF parameters.

  19. Investigation of possible sun-weather relationships

    Energy Technology Data Exchange (ETDEWEB)

    Businger, S

    1978-01-01

    Statistical correlations between anomalous solar activity (as denoted by large solar flares, active plages, and interplanetary magnetic sector boundaries) and the circulation of the troposphere are reviewed. Two indices (measuring atmospheric vorticity and mean zonal geostrophic flow in the northern hemisphere) are analyzed in an effort to reveal possible sun-weather relationships. The result of this analysis provides no additional statistical evidence for a connection between solar activity and the weather. Finally, physical mechanisms that have been suggested to explain the claimed correlations are discussed.

  20. Mapping Magnetic Field Lines between the Sun and Earth

    Science.gov (United States)

    Li, Bo; Cairns, Iver; Gosling, J. T.; Lobzin, Vasili; Steward, Graham; Neudegg, Dave; Owens, Mathew

    2016-07-01

    Magnetic field topologies between the Sun and Earth are important for the connectivity to Earth of solar suprathermal particles, e.g., solar energetic particles and the electrons in type III solar radio bursts. An approach is developed for mapping large-scale magnetic field lines in the solar equatorial plane, using near-Earth observations and a solar wind model with nonzero azimuthal magnetic field at the source surface. The predicted field line maps show that near both minimal and maximal solar activity the field lines are typically open and that loops with both ends either connected to or disconnected from the Sun occur sometimes. The open field lines, nonetheless, often do not closely follow the Parker spiral, being less or more tightly wound, or strongly azimuthally or radially oriented, or inverted. Assessments of the mapped field line configurations using time-varying suprathermal electron pitch angle distributions (PADs) observed by Wind show that the mapping predictions agree quantitatively (˜90%) with the PAD observations and outperform (by ˜20%) the predictions using the standard Parker spiral model. Application to a type III radio burst observed by Ulysses and Wind shows that the mapping prediction agrees well with the local magnetic field line traced by the type III source path, which covers heliocentric distances of ˜0.1--0.4 AU. Furthermore, applications to local field structures inferred from ACE observations demonstrate that the mapping can predict the majority (65-75%) of the local field line inversions for the multiple phases of the solar cycle.

  1. A Novel Multi-Aperture Based Sun Sensor Based on a Fast Multi-Point MEANSHIFT (FMMS Algorithm

    Directory of Open Access Journals (Sweden)

    Gao-Fei Zhang

    2011-03-01

    Full Text Available With the current increased widespread interest in the development and applications of micro/nanosatellites, it was found that we needed to design a small high accuracy satellite attitude determination system, because the star trackers widely used in large satellites are large and heavy, and therefore not suitable for installation on micro/nanosatellites. A Sun sensor + magnetometer is proven to be a better alternative, but the conventional sun sensor has low accuracy, and cannot meet the requirements of the attitude determination systems of micro/nanosatellites, so the development of a small high accuracy sun sensor with high reliability is very significant. This paper presents a multi-aperture based sun sensor, which is composed of a micro-electro-mechanical system (MEMS mask with 36 apertures and an active pixels sensor (APS CMOS placed below the mask at a certain distance. A novel fast multi-point MEANSHIFT (FMMS algorithm is proposed to improve the accuracy and reliability, the two key performance features, of an APS sun sensor. When the sunlight illuminates the sensor, a sun spot array image is formed on the APS detector. Then the sun angles can be derived by analyzing the aperture image location on the detector via the FMMS algorithm. With this system, the centroid accuracy of the sun image can reach 0.01 pixels, without increasing the weight and power consumption, even when some missing apertures and bad pixels appear on the detector due to aging of the devices and operation in a harsh space environment, while the pointing accuracy of the single-aperture sun sensor using the conventional correlation algorithm is only 0.05 pixels.

  2. Sun-Earth Day Connects History, Culture and Science

    Science.gov (United States)

    Cline, T.; Thieman, J.

    2003-12-01

    The NASA Sun-Earth Connection Education forum annually promotes and event called Sun-Earth Day: a national celebration of the Sun, the space around the Earth (geospace), and how all of it affects life on our planet. For the past 3 years this event has provided a venue by which classrooms, museums, planetaria, and at NASA centers have had a sensational time sharing stories, images, and activities related to the Sun-Earth connections and the views o fthe Sun from Earth. Each year we select a different theme by which NASA Space Science can be further related to cross-curricular activities. Sun-Earth Day 2002, "Celebrate the Equinox", drew parallels between Native American Cultures and NASA's Sun-Earth Connection research via cultural stories, interviews, web links, activities and Native American participation. Sun-Earth Day 2003, "Live From the Aurora", shared the beauty of the Aurora through a variety of activities and stories related to perspectives of Northern Peoples. Sun-Earth Day 2004 will share the excitement of the transit of Venus through comparisons of Venus with Earth and Mars, calculations of the distances to nearby stars, and the use of transits to identify extra-solar planets. Finally, Sun-Earth Day 2005 will bring several of these themes together by turning our focus to the history and culture surrounding ancient observatories such as Chaco Canyon, Machu Picchu, and Chichen Itza.

  3. The Sun and the Earth's Climate

    Directory of Open Access Journals (Sweden)

    Haigh Joanna D.

    2007-10-01

    Full Text Available Variations in solar activity, at least as observed in numbers of sunspots, have been apparent since ancient times but to what extent solar variability may affect global climate has been far more controversial. The subject had been in and out of fashion for at least two centuries but the current need to distinguish between natural and anthropogenic causes of climate change has brought it again to the forefront of meteorological research. The absolute radiometers carried by satellites since the late 1970s have produced indisputable evidence that total solar irradiance varies systematically over the 11-year sunspot cycle, relegating to history the term “solar constant”, but it is difficult to explain how the apparent response to the Sun, seen in many climate records, can be brought about by these rather small changes in radiation. This article reviews some of the evidence for a solar influence on the lower atmosphere and discusses some of the mechanisms whereby the Sun may produce more significant impacts than might be surmised from a consideration only of variations in total solar irradiance.

  4. Seismic Sounding of Convection in the Sun

    CERN Document Server

    Hanasoge, Shravan; Sreenivasan, Katepalli R

    2015-01-01

    Our Sun, primarily composed of ionized hydrogen and helium, has a surface temperature of 5777~K and a radius $R_\\odot \\approx 696,000$ km. In the outer $R_\\odot/3$, energy transport is accomplished primarily by convection. Using typical convective velocities $u\\sim100\\,\\rm{m\\,s^{-1}}$ and kinematic viscosities of order $10^{-4}$ m$^{2}$s$^{-1}$, we obtain a Reynolds number $Re \\sim 10^{14}$. Convection is thus turbulent, causing a vast range of scales to be excited. The Prandtl number, $Pr$, of the convecting fluid is very low, of order $10^{-7}$\\,--\\,$10^{-4}$, so that the Rayleigh number ($\\sim Re^2 Pr$) is on the order of $10^{21}\\,-\\,10^{24}$. Solar convection thus lies in extraordinary regime of dynamical parameters, highly untypical of fluid flows on Earth. Convective processes in the Sun drive global fluid circulations and magnetic fields, which in turn affect its visible outer layers ("solar activity") and, more broadly, the heliosphere ("space weather"). The precise determination of the depth of sola...

  5. Exoplanets Clue to Sun's Curious Chemistry

    Science.gov (United States)

    2009-11-01

    A ground-breaking census of 500 stars, 70 of which are known to host planets, has successfully linked the long-standing "lithium mystery" observed in the Sun to the presence of planetary systems. Using ESO's successful HARPS spectrograph, a team of astronomers has found that Sun-like stars that host planets have destroyed their lithium much more efficiently than "planet-free" stars. This finding does not only shed light on the lack of lithium in our star, but also provides astronomers with a very efficient way of finding stars with planetary systems. "For almost 10 years we have tried to find out what distinguishes stars with planetary systems from their barren cousins," says Garik Israelian, lead author of a paper appearing this week in the journal Nature. "We have now found that the amount of lithium in Sun-like stars depends on whether or not they have planets." Low levels of this chemical element have been noticed for decades in the Sun, as compared to other solar-like stars, and astronomers have been unable to explain the anomaly. The discovery of a trend among planet-bearing stars provides a natural explanation to this long-standing mystery. "The explanation of this 60 year-long puzzle is for us rather simple," adds Israelian. "The Sun lacks lithium because it has planets." This conclusion is based on the analysis of 500 stars, including 70 planet-hosting stars. Most of these stars were monitored for several years with ESO's High Accuracy Radial Velocity Planet Searcher. This spectrograph, better known as HARPS, is attached to ESO's 3.6-metre telescope and is the world's foremost exoplanet hunter. "This is the best possible sample available to date to understand what makes planet-bearing stars unique," says co-author Michel Mayor. The astronomers looked in particular at Sun-like stars, almost a quarter of the whole sample. They found that the majority of stars hosting planets possess less than 1% of the amount of lithium shown by most of the other stars

  6. A new perspective on quiet Sun magnetism

    Institute of Scientific and Technical Information of China (English)

    LITES Bruce William

    2009-01-01

    The Hinode mission has provided us with a new, quantitative view of the magnetism of the quiet Sun. It has revealed that the quiet internetwork areas are blanketed by horizontal fields that appear at first sight to have more flux than the vertical fields resolved on the same 0.3″ size scale. These measurements point to the possibility that the horizontal fields might be the primary source of the "hidden turbulent flux" of the quiet Sun anticipated from Hanle effect depolarization. In this paper, evidence is presented suggesting that the "seething" horizontal fields observed by Harvey in 2007 and the horizontal fields revealed by Hinode are the same phenomenon. Because the seething fields appear to be of uniform fluctuation over the whole disk, the phenomenon is most likely not associated with the dynamo source of solar activity. Thus, the small-scale "hidden turbulent flux" lends support to the notion of a local solar dynamo acting on granular sizes and time scales.

  7. Promoting sun safety among zoo visitors.

    Science.gov (United States)

    Mayer, J A; Lewis, E C; Eckhardt, L; Slymen, D; Belch, G; Elder, J; Engelberg, M; Eichenfield, L; Achter, A; Nichols, T; Walker, K; Kwon, H; Talosig, M; Gearen, C

    2001-09-01

    Each year, millions of children visit zoological parks, where they are exposed to long bouts of ultraviolet radiation (UVR). We conducted a study in the winter and replicated it in the summer to evaluate an intervention for reducing UVR exposure during the zoo visit. Each study used a nonequivalent control group design: one zoological site received the intervention and a second received evaluation only. Key outcome measures consisted of observed prevalence of hat use by exiting children (N = 8,721 and 8,524, respectively, in winter and summer studies) and purchase rates of sunscreen and hats in zoo gift shops. Intervention consisted of tip sheets for parents, children's activities, prompts, and discounts off the price of sunscreen and sun-protective hats. In the summer study, sales of both sunscreen and target hats increased significantly at the intervention site relative to the control site, whereas in the winter study, only sunscreen sales at the intervention site had a significant (relative) increase. Children's hat use increased significantly at the intervention site, but only in the winter study. The multicomponent program was effective in promoting purchases of sun-safe items, but its impact on children's hat use was inconclusive. Copyright 2001 American Health Foundation and Academic Press.

  8. Light Work: Contemporary Artists Consider the Sun

    Science.gov (United States)

    Cummins, Rebecca

    2005-01-01

    Modern day life and timekeepers have profoundly affected the way we conceptualize time and our position in the universe. Over the past year, I have been investigating the apparent movement of the Sun both sculpturally and photographically. In this paper, I discuss my collaborations with Woody Sullivan and highlight several of the sundials, both gigantic and intimate, created by University of Washington students in the class Where is Noon? Regarding Giant Sundials that we co-taught in Spring 2003. I have continued to develop artistic approaches to solar events. Some of these sunworks have not been designed specifically to measure the exact time of day as a classic sundial does, but to stimulate a greater awareness of our subjective and paradoxical relationship to nature and technology. Other, almost domestic, poetic, humorous or intimate ways of interacting with science and technology are being actively explored. I will also provide a background to previous works I have done in relation to the Sun and optics, and briefly mention artists who are using astronomical events as a point of departure.

  9. Two sun-like superflare stars rotating as slow as the Sun*

    Science.gov (United States)

    Nogami, Daisaku; Notsu, Yuta; Honda, Satoshi; Maehara, Hiroyuki; Notsu, Shota; Shibayama, Takuya; Shibata, Kazunari

    2014-04-01

    We report on the results of high dispersion spectroscopy of two "superflare stars," KIC 9766237 and KIC 9944137 with Subaru/HDS. Superflare stars are G-type main sequence stars, but show gigantic flares compared to the Sun, which have recently been discovered in the data obtained with the Kepler spacecraft. Though most of these stars are thought to have a rotation period shorter than 10 d on the basis of photometric variabilities, the two targets of the present paper are estimated to have rotation periods of 21.8 d and 25.3 d. Our spectroscopic results clarified that these stars have stellar parameters similar to those of the Sun in terms of the effective temperature, surface gravity, and metallicity. The projected rotational velocities derived by us are consistent with the photometric rotation period, indicating a fairly high inclination angle. The average strength of the magnetic field on the surface of these stars are estimated to be 1-20 G, by using the absorption line of Ca II 8542. We could not detect any hint of binarity in our spectra, although more data are needed to firmly rule out the presence of an unseen low-mass companion. These results claim that the spectroscopic properties of these superflare stars are very close to those of the Sun, and support the hypothesis that the Sun might cause a superflare.

  10. Perry, Kelvin, and the age of the sun

    Science.gov (United States)

    Tipler, Frank J.

    2013-04-01

    Lord Kelvin argued that the Sun had to be between 20 and 100 million years old, based on the assumption that the Sun's energy source was gravitational contraction. As everyone now knows, the Sun's actual power source is the thermonuclear fusion of hydrogen into helium. But Kelvin's number is based on a physical assumption for which he could give no justification: the Sun's density is approximately constant. Had Kelvin assumed instead that the Sun had a small core near a black hole radius - an assumption allowed by the knowledge of physicists at the end of the nineteenth century - he would have obtained an age for the Sun as long as 10 trillion years, completely consistent with the long time scale required for evolution. Conversely, had Kelvin accepted the geologists' time scale, he would have been forced to acknowledge the existence of very dense objects, making it easier for twentieth century astronomers to accept the existence of black holes and neutron stars.

  11. Scalar model of SU(N) glueball \\`a la Heisenberg

    CERN Document Server

    Dzhunushaliev, Vladimir

    2016-01-01

    Nonperturbative model of glueball is studied. The model is based on the nonperturbative quantization technique suggested by Heisenberg. 2- and 4-point Green functions for a gauge potential are expressed in terms of two scalar fields. The first scalar field describes quantum fluctuations of a subgroup $SU(n) \\subset SU(N)$, and the second one describes quantum fluctuations of coset $SU(N) / SU(n)$. An effective Lagrangian for the scalar fields is obtained. The coefficients for all terms in the Lagrangian are calculated, and it is shown that they depend on $\\dim SU(n), \\dim SU(N)$. It is demonstrated that spherically symmetric solution describing the glueball does exist.

  12. Sun One Portal Server体系架构

    Institute of Scientific and Technical Information of China (English)

    王勇泉

    2003-01-01

    目前,门户市场上存在着国内外多种多样的产品,本文主要介绍Sun公司的Sun ONE Portal Servero Sun ONE Portal Server到目前为止,在全球拥有400多个客户,分布于金融、电信、政府、汽车、制造、教育等行业。Sun ONE Portal Server是Sun ONE的重要组成部分。首先,让我们来看看Sun ONE(Sun Open Net Environment)的

  13. Multi-Aperture CMOS Sun Sensor for Microsatellite Attitude Determination

    Directory of Open Access Journals (Sweden)

    Michele Grassi

    2009-06-01

    Full Text Available This paper describes the high precision digital sun sensor under development at the University of Naples. The sensor determines the sun line orientation in the sensor frame from the measurement of the sun position on the focal plane. It exploits CMOS technology and an original optical head design with multiple apertures. This allows simultaneous multiple acquisitions of the sun as spots on the focal plane. The sensor can be operated either with a fixed or a variable number of sun spots, depending on the required field of view and sun-line measurement precision. Multiple acquisitions are averaged by using techniques which minimize the computational load to extract the sun line orientation with high precision. Accuracy and computational efficiency are also improved thanks to an original design of the calibration function relying on neural networks. Extensive test campaigns are carried out using a laboratory test facility reproducing sun spectrum, apparent size and distance, and variable illumination directions. Test results validate the sensor concept, confirming the precision improvement achievable with multiple apertures, and sensor operation with a variable number of sun spots. Specifically, the sensor provides accuracy and precision in the order of 1 arcmin and 1 arcsec, respectively.

  14. Sun Protection Belief Clusters: Analysis of Amazon Mechanical Turk Data.

    Science.gov (United States)

    Santiago-Rivas, Marimer; Schnur, Julie B; Jandorf, Lina

    2016-12-01

    This study aimed (i) to determine whether people could be differentiated on the basis of their sun protection belief profiles and individual characteristics and (ii) explore the use of a crowdsourcing web service for the assessment of sun protection beliefs. A sample of 500 adults completed an online survey of sun protection belief items using Amazon Mechanical Turk. A two-phased cluster analysis (i.e., hierarchical and non-hierarchical K-means) was utilized to determine clusters of sun protection barriers and facilitators. Results yielded three distinct clusters of sun protection barriers and three distinct clusters of sun protection facilitators. Significant associations between gender, age, sun sensitivity, and cluster membership were identified. Results also showed an association between barrier and facilitator cluster membership. The results of this study provided a potential alternative approach to developing future sun protection promotion initiatives in the population. Findings add to our knowledge regarding individuals who support, oppose, or are ambivalent toward sun protection and inform intervention research by identifying distinct subtypes that may best benefit from (or have a higher need for) skin cancer prevention efforts.

  15. Interstellar Dust Close to the Sun

    CERN Document Server

    Frisch, Priscilla C

    2012-01-01

    The low density interstellar medium (ISM) close to the Sun and inside of the heliosphere provides a unique laboratory for studying interstellar dust grains. Grain characteristics in the nearby ISM are obtained from observations of interstellar gas and dust inside of the heliosphere and the interstellar gas towards nearby stars. Comparison between the gas composition and solar abundances suggests that grains are dominated by olivines and possibly some form of iron oxide. Measurements of the interstellar Ne/O ratio by the Interstellar Boundary Explorer spacecraft indicate that a high fraction of interstellar oxygen in the ISM must be depleted onto dust grains. Local interstellar abundances are consistent with grain destruction in ~150 km/s interstellar shocks, provided that the carbonaceous component is hydrogenated amorphous carbon and carbon abundances are correct. Variations in relative abundances of refractories in gas suggest variations in the history of grain destruction in nearby ISM. The large observed ...

  16. Imaging convection and magnetism in the sun

    CERN Document Server

    Hanasoge, Shravan

    2015-01-01

    This book reviews the field of helioseismology and its outstanding challenges and also offers a detailed discussion of the latest computational methodologies. The focus is on the development and implementation of techniques to create 3-D images of convection and magnetism in the solar interior and to introduce the latest computational and theoretical methods to the interested reader. With the increasing availability of computational resources, demand for greater accuracy in the interpretation of helioseismic measurements and the advent of billion-dollar instruments taking high-quality observations, computational methods of helioseismology that enable probing the 3-D structure of the Sun have increasingly become central. This book will benefit students and researchers with proficiency in basic numerical methods, differential equations and linear algebra who are interested in helioseismology.

  17. Choosing an expected sun protection factor value.

    Science.gov (United States)

    Sica, John R; Caswell, Michael

    2015-01-01

    Sun protection factor, SPF, is a measure of the efficacy of a topical sunscreen product; the higher the SPF, the greater the blockage of ultraviolet-induced erythema. While there are several methods to determine SPF, the Food and Drug Administration (FDA) methods are unique. The FDA methods define the label SPF value as the largest whole integer after subtracting an "A" value from the mean SPF. The A value, composed of the product of the upper 5% point of the t-distribution and the standard deviation (SD), divided by √(n), where n equals the number of subjects, has a significant impact on the label SPF value. Two examples explore this impact. Development of strategies to mitigate the impact of A using expected SPF values are explored using historical clinical trial data. A more enlightened choice of expected SPF values is shown to lead to higher label SPF values.

  18. Coronal Mass Ejections: From Sun to Earth

    Science.gov (United States)

    Patsourakos, S.

    2016-06-01

    Coronal Mass Ejections (CMEs) are gigantic expulsions of magnetized plasmas from the solar corona into the interplanetary (IP) space. CMEs spawn ~ 1015 gr of mass and reach speeds ranging between several hundred to a few thousand km/s (e.g., Gopalswamy et al. 2009; Vourlidas et al. 2010). It takes 1-5 days for a CME to reach Earth. CMEs are one of the most energetic eruptive manifestations in the solar system and are major drivers of space weather via their magnetic fields and energetic particles, which are accelerated by CME-driven shocks. In this review we give a short account of recent, mainly observational, results on CMEs from the STEREO and SDO missions which include the nature of their pre-eruptive and eruptive configurations and the CME propagation from Sun to Earth. We conclude with a discussion of the exciting capabilities in CME studies that will soon become available from new solar and heliospheric instrumentation.

  19. An Encounter between the Sun and Venus

    CERN Multimedia

    2004-01-01

    The astronomical event of the year will take place on Tuesday, 8 June, when Venus transits across the disk of the sun. In the framework of CERN's 50th anniversary celebrations, the CERN Astronomy Club and the Orion Club invite you to attend their observation of the event on the car park of the Val-Thoiry shopping centre (France) between 7.15 a.m. and 1.30 p.m. Various instruments will be set up in a special tent so that the event can be observed without any risk of damage to the eyes. As the observation of this astronomical event will depend on the weather forecast, confirmation of the above arrangements will be given on the 50th anniversary website the day before.

  20. Earth, Moon, Sun, and CV Accretion Disks

    CERN Document Server

    Montgomery, M M

    2009-01-01

    Net tidal torque by the secondary on a misaligned accretion disk, like the net tidal torque by the Moon and the Sun on the equatorial bulge of the spinning and tilted Earth, is suggested by others to be a source to retrograde precession in non-magnetic, accreting Cataclysmic Variable (CV) Dwarf Novae systems that show negative superhumps in their light curves. We investigate this idea in this work. We generate a generic theoretical expression for retrograde precession in spinning disks that are misaligned with the orbital plane. Our generic theoretical expression matches that which describes the retrograde precession of Earths' equinoxes. By making appropriate assumptions, we reduce our generic theoretical expression to those generated by others, or to those used by others, to describe retrograde precession in protostellar, protoplanetary, X-ray binary, non-magnetic CV DN, quasar and black hole systems. We find that differential rotation and effects on the disk by the accretion stream must be addressed. Our a...

  1. Convectively driven vortex flows in the Sun

    CERN Document Server

    Bonet, J A; Almeida, J Sanchez; Cabello, I; Domingo, V

    2008-01-01

    We have discovered small whirlpools in the Sun, with a size similar to the terrestrial hurricanes (<~0.5 Mm). The theory of solar convection predicts them, but they had remained elusive so far. The vortex flows are created at the downdrafts where the plasma returns to the solar interior after cooling down, and we detect them because some magnetic bright points (BPs) follow a logarithmic spiral in their way to be engulfed by a downdraft. Our disk center observations show 0.009 vortexes per Mm^2, with a lifetime of the order of 5 min, and with no preferred sense of rotation. They are not evenly spread out over the surface, but they seem to trace the supergranulation and the mesogranulation. These observed properties are strongly biased by our type of measurement, unable to detect vortexes except when they are engulfing magnetic BPs.

  2. Substructure of Quiet Sun Bright Points

    CERN Document Server

    Andic, Aleksandra; Goode, Phillip R

    2010-01-01

    Since photospheric bright points (BPs) were first observed, there has been a question as to how are they structured. Are they just single flux tubes or a bundle of the flux-tubes? Surface photometry of the quiet Sun (QS) has achieved resolution close to 0.1" with the New Solar Telescope at Big Bear Solar Observatory. This resolution allowed us to detect a richer spectrum of BPs in the QS. The smallest BPs we observed with TiO 705.68 nm were 0.13", and we were able to resolve individual components in some of the BPs clusters and ribbons observed in the QS, showing that they are composed of the individual BPs. Average size of observed BPs was 0.22".

  3. Cartography of the sun and the stars

    CERN Document Server

    Neiner, Coralie

    2016-01-01

    The mapping of the surface of stars requires diverse skills, analysis techniques and advanced modeling, i.e. the collaboration of scientists in various specialties. This volume gives insights into new techniques allowing for the first time to obtain resolved images of stars. It takes stock of what has been achieved so far in Chile, on the ESO VLTI instrument or, in the States, on the CHARA instrument. In recent times interferometry, combined with adaptive optics has allowed to reconstruct images of stars. Besides the Sun (of course) by now five stars have been resolved in detail. In addition to interferometry, this book highlights techniques used for mapping the surfaces of stars using photometry made by space observatories; Zeeman- and Doppler Imaging; mapping the surface element abundances via spectroscopy. This book will also take stock of the best images of the  solar surface, made by connecting the differential rotation to the underlying physical parameters derived from helioseismology. Recent measureme...

  4. Sun-Earth Day 2005: Ancient Observatories: Timeless Knowledge

    Science.gov (United States)

    Thieman, J. R.; Cline, T.; Lewis, E.; Hawkins, I.; Odenwald, S.; Mayo, L.

    2005-05-01

    The NASA Sun-Earth Connection Education Forum (SECEF) annually promotes an event called Sun-Earth Day. For Sun-Earth Day 2005 SECEF has selected a theme called "Ancient Observatories: Timeless Knowledge. This year's Sun-Earth Day theme is your ticket to a fascinating journey through time as we explore centuries of sun watching by a great variety of cultures. From ancient solar motion tracking to modern solar activity monitoring the Sun has always occupied an important spot in mankind's quest to understand the Universe. Sun-Earth Day events usually are centered on the spring equinox around March 21, but this year there has already been a webcast from the San Francisco Exploratorium and the Native American ruins at Chaco Canyon, New Mexico on the day of winter solstice 2004. There will be another webcast on March 20 live from Chichen Itza, Mexico highlighting the solar alignment that makes a serpent appear on one of the ancient pyramids. The website http://sunearthday.nasa.gov has been developed to provide the necessary resources and opportunities for participation by scientists and educators in giving school or general public programs about Sun-Earth Day. The goal is to involve as much of the student population and the public in this event as possible and to help them understand the importance of the Sun for ancient and modern peoples. Through engaging activities available on the website, classrooms and museums can create their own event or participate in one of the opportunities we make available. Scientists, educators, amateur astronomers, and museums are invited to register on the website to receive a free packet of materials about Sun-Earth Day for use in making presentations or programs about the event. Past and future Sun-Earth Days will be discussed as well.

  5. SOHO reveals how sunspots take a stranglehold on the Sun

    Science.gov (United States)

    2001-11-01

    what order the contestants arrive at the finish. Here the runners are packets of sound waves, and the obstacles are local variations in temperature, magnetic fields and gas flows beneath the Sun's surface. "We needed better mathematical tricks," comments Duvall. "So we put together ideas from classical and quantum physics, and also from a recent advance in seismology on the Earth." In an earlier application of solar tomography, the team examined in detail the ante-natal events for an important group of sunspots born on 12 January 1998. They found sound waves beginning to travel faster and faster through the region where sunspots were about to form. Less than half a day elapsed between signs of unusual magnetic activity in the Sun's interior and the appearance of the dark spots on a previously unblemished surface. "Sunspots form when intense magnetic fields break through the visible surface," says Alexander Kosovichev of Stanford. "We could see the magnetic field shooting upwards like a fountain, faster than we expected." Even late on the previous day there was little hint of anything afoot, either at the surface or in the interior. By midnight (Universal Time) a region of strong magnetic field had risen from a depth of 18 000 kilometres and was already half way to the surface, travelling at 4500 km/hr. Sound speeds were increasing above the perturbed zone. By 8:00 a.m. an intense, rope-like magnetic field was in possession of a column of gas 20 000 kilometres wide and reaching almost to the visible surface. In the uppermost layer beneath the surface, the magnetic rope divided itself into strands that made the individual sunspots of the group. Under a large, well-established sunspot, in June 1998, the sound waves revealed a persistent column of hot, magnetised gas rising from deep in the interior. At a depth of 4000 kilometres it spread fingers towards neighbouring parts of the surface where it sustained some smaller sunspots. The magnetic column was not connected to

  6. Improving sun-safe knowledge, attitude and behaviour in parents of primary school children: a pilot study.

    Science.gov (United States)

    Cercato, M C; Nagore, E; Ramazzotti, V; Sperduti, I; Guillén, C

    2013-03-01

    Excessive sun exposure, mainly in childhood, represents one of the major skin cancer risk factors. Sun protection habits should start early in life to be effective. The purpose of this study was to investigate knowledge, attitude and sun protection behaviour in parents (P) and in their children (C). The educational intervention addressed the parents of 131 primary school pupils in Valencia, Spain, during the school year 2007-2008. A self-administered pre- and post-intervention questionnaire was handed in during school hours to be filled in by parents. Parents' compliance was very high (88 %). At baseline, regular high-sun-protective-factor (>15) sunscreen use was common (P, 64 %; C, 95 %); wearing clothing (T-shirt: P, 34 %, C, 62 %; hat: P, 29 %, C, 64 %) and sun avoidance at midday (P, 23 %; C, 29 %) were less frequent. Almost 70 % of parents reported difficulties, mainly due to the children's refusal. A high knowledge score (median, 6/7) and a medium/high attitude score (median, 24/30) in parents were observed; however, lifetime sunburn history was generally reported (P, 88 %; C, 24 %). Factors associated with parents' knowledge were a personal history of sunburns and regularly repeating sunscreen application to children (median score: 6 vs 5; p ≤ 0.01) Predictors of a more favourable attitude were female caretakers and having daughters (median score: 30 vs 25 and 25 vs 24, respectively; p ≤ 0.01). A trend towards limited post-intervention positive changes emerged; however, sun avoidance habit decreased (35 vs 20 %, p = 0.01). Despite a high level of parents' knowledge, sun protection in children is not adequate, and sunburns are not uncommon. Unfavourable beliefs and attitudes need to be overcome and quality of messages improved to achieve sun-safe exposure in children.

  7. Sun Protection Policies of Australian Primary Schools in a Region of High Sun Exposure

    Science.gov (United States)

    Harrison, S. L.; Garzón-Chavez, D. R.; Nikles, C. J.

    2016-01-01

    Queensland, Australia has the highest rates of skin cancer globally. Predetermined criteria were used to score the comprehensiveness of sun protection policies (SPP) of primary schools across Queensland. SPP were sought for schools in 10 regions (latitude range 16.3°S-28.1°S) from 2011 to 2014. Of the 723 schools sampled, 90.9% had a written SPP…

  8. Correction of sun glint effect on MIVIS data of the Sicily campaign in July 2000

    Directory of Open Access Journals (Sweden)

    E. Zappitelli

    2006-06-01

    Full Text Available To assess the suspended and dissolved matter in water in the visible and near infrared spectral regions it is necessary to estimate with adequate accuracy the water leaving radiance. Consequently radiance measured by a remote sensor has to be corrected from the atmospheric and the sea surface effects consisting in the path radiance and the sun and sky glitter radiance contributions. This paper describes the application of the sun glint correction scheme on to airborne hyperspectral MIVIS measurements acquired on the area of the Straits of Messina during the campaign in July 2000. In the Messina case study data have been corrected for the atmospheric effects and for the sun-glitter contribution evaluated following the method proposed by Cox and Munk (1954, 1956. Comparison between glitter contaminated and glitter free data has been made taking into account the radiance profiles relevant to selected scan lines and the spectra of different pixels belonging to the same scan line and located out and inside the sun glitter area. The results show that spectra after correction have the same profile as the contaminated ones, although, at this stage, free glint data have not yet been used in water constituent retrieval and consequently the reliability of such correction cannot be completely evaluated.

  9. Artificial Sun synchronous frozen orbit control scheme design based on J2 perturbation

    Institute of Scientific and Technical Information of China (English)

    Gong-Bo Wang; Yun-He Meng; Wei Zheng; Guo-Jian Tang

    2011-01-01

    Sun synchronous orbit and frozen orbit formed due to J2 perturbation have very strict constraints on orbital parameters,which have restricted the application a lot.In this paper,several control strategies were illustrated to realize Sun synchronous frozen orbit with arbitrary orbital elements using continuous low-thrust.Firstly,according to mean element method,the averaged rate of change of the orbital elements,originating from disturbing constant accelerations over one orbital period,was derived from Gauss' variation of parameters equations.Then,we proposed that binormal acceleration could be used to realize Sun synchronous orbit,and radial or transverse acceleration could be adopted to eliminate the rotation of the argument of the perigee.Finally,amending methods on the control strategies mentioned above were presented to eliminate the residual secular growth.Simulation results showed that the control strategies illustrated in this paper could realize Sun synchronous frozen orbit with arbitrary orbital elements,and can save much more energy than the schemes presented in previous studies,and have no side effect on other orbital parameters' secular motion.

  10. Polar Magnetic Field Reversals of the Sun in Maunder Minimum

    Indian Academy of Sciences (India)

    V. I. Makarov; A. G. Tlatov

    2000-09-01

    A possible scenario of polar magnetic field reversal of the Sun during the Maunder Minimum (1645-1715) is discussed using data of magnetic field reversals of the Sun for 1880-1991 and the 14C content variations in the bi-annual rings of the pine-trees in 1600-1730 yrs.

  11. Quadrant to Measure the Sun's Altitude

    Science.gov (United States)

    Windsor, A Morgan, Jr.

    2013-01-01

    The changing altitude of the Sun (either over the course of a day or longer periods) is a phenomenon that students do not normally appreciate. However, the altitude of the Sun affects many topics in disciplines as diverse as astronomy, meteorology, navigation, or horology, such as the basis for seasons, determination of latitude and longitude, or…

  12. Sun avoidance strategies at the Large Millimeter Telescope

    Science.gov (United States)

    Souccar, Kamal; Smith, David R.; Schloerb, F. Peter; Wallace, Gary

    2016-07-01

    The Large Millimeter Telescope observatory is extending its night time operation to the day time. A sun avoidance strategy was therefore implemented in the control system in real-time to avoid excessive heating and damage to the secondary mirror and the prime focus. The LMT uses an "on-the-fly" trajectory generator that receives as input the target location of the telescope and in turn outputs a commanded position to the servo system. The sun avoidance strategy is also implemented "on-the-fly" where it intercepts the input to the trajectory generator and alters that input to avoid the sun. Two sun avoidance strategies were explored. The first strategy uses a potential field approach where the sun is represented as a high-potential obstacle in the telescope's workspace and the target location is represented as a low-potential goal. The potential field is repeatedly calculated as the sun and the telescope move and the telescope follows the induced force by this field. The second strategy is based on path planning using visibility graphs where the sun is represented as a polygonal obstacle and the telescope follows the shortest path from its actual position to the target location via the vertices of the sun's polygon. The visibility graph approach was chosen as the favorable strategy due to the efficiency of its algorithm and the simplicity of its computation.

  13. Relationship Factors and Couples' Engagement in Sun Protection

    Science.gov (United States)

    Manne, S. L.; Coups, E. J.; Kashy, D. A.

    2016-01-01

    Individuals may be more motivated to adopt health practices if they consider the benefits of these behaviors for their close relationships. The goal of this study was to examine couple concordance with sun protection and use the interdependence and communal coping theory to evaluate the role of relationship factors in sun protection. One hundred…

  14. Regular Biology Students Learn Like AP Students with SUN

    Science.gov (United States)

    Batiza, Ann; Luo, Wen; Zhang, Bo; Gruhl, Mary; Nelson, David; Hoelzer, Mark; Ning, Ling; Roberts, Marisa; Knopp, Jonathan; Harrington, Tom; LaFlamme, Donna; Haasch, Mary Anne; Vogt, Gina; Goodsell, David; Marcey, David

    2016-01-01

    The SUN approach to biological energy transfer education is fundamentally different from past practices that trace chemical and energy inputs and outputs. The SUN approach uses a hydrogen fuel cell to convince learners that electrons can move from one substance to another based on differential attraction. With a hydrogen fuel cell, learners can…

  15. Wien's Law and the Temperature of the Sun

    Science.gov (United States)

    Biermann, Mark L.; Katz, Debora M.; Aho, Robert; Diaz-Barriga, James; Petron, Jerome

    2002-10-01

    A simple approach is used in an attempt to determine the temperature of the sun by modeling the sun as a blackbody radiator and applying Wein's Law. Apparently excellent results are obtained, but the results are false as a consequence of two corrections which cancel out.

  16. Mr. Sun Laiyan Appointed as Administrator of CNSA

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    The State Council of the People's Republic of China announced on April 23, 2004 that Mr. Sun Laiyan was appointed to be the Administrator of China National Space Administration (CNSA). Mr. Luan Enjie was announced to retire from the office. Mr. Sun Laiyan, born in October 1957, graduated from Xian Communication

  17. Growth and morphogenesis of sun and shade plants

    NARCIS (Netherlands)

    Corre, W.J.

    1984-01-01

    A number of species of sun and shade plants in the vegetative phase were grown in different light intensities, different light qualities (r/fr ratio) and different combinations of light intensity and nutrient supply. Sun and shade species were also grown at various plant densities and in interspecif

  18. Sun Safety Knowledge, Attitudes, and Behaviors among Beachgoing Adolescents

    Science.gov (United States)

    Merten, Julie Williams; Higgins, Sue; Rowan, Alan; Pragle, Aimee

    2014-01-01

    Background: Skin cancer rates are rising and could be reduced with better sun protection behaviors. Adolescent exposure to ultraviolet (UV) radiation is damaging because it can lead to skin cancer. This descriptive study extends understanding of adolescent sun exposure attitudes, knowledge, and behaviors. Methods: A sample of 423 beachgoing…

  19. Description of the Sun as a Star: General Physical Characteristics

    Science.gov (United States)

    Kucera, Theresa; Crannell, Carol Jo

    2000-01-01

    Numerical parameters characterizing the size and energy output of the sun are presented. These values are the standard yardstick by which other stars are measured. The large number of significant digits tabulated here serve mainly to illustrate the precision to which these parameters are known. Also listed are parameters characterizing the earth's orbit around the sun and the intensity of the sun's radiation at the mean orbital distance. The appearance of the sun depends critically on how it is observed. Each type of radiation observed carries specific information about the physical processes at work on the sun. Special types of instruments reveal aspects otherwise invisible. Coronagraphs reveal the dimmer outer regions of the sun's atmosphere otherwise visible only during total solar eclipses. Spectroscopy can reveal motions, magnetic field strengths, temperatures and densities. In situ measurements have revealed the characteristics of the solar wind and extended our knowledge of the solar magnetic field both near the earth and beyond the orbits of the planets. As an example, the sun's disk observed almost simultaneously in six different wavelengths of light is shown. In visible light we can see the white disk of the sun with the dark spots known as sunspots. By analyzing the spectral lines produced by the sun we can measure the strength of the sun's magnetic field at its surface, producing a magnetogram. This magnetogram reveals that the sunspots are regions of intense magnetic field. Further images of the sun reveal that the sunspot regions are just the bases of systems of hot loops which emit radio-waves, ultraviolet light and X-rays. The sun imaged in a spectral line of hydrogen known as "H alpha" is shown. In this line we also see the long dark "filaments". These filaments form in long channels between areas of opposing magnetic field. Such channels can be seen in the ultraviolet image. Data concerning the sun are obtained with many different kinds of

  20. The Sun is Condensed Matter and has a Real Surface

    Science.gov (United States)

    Robitaille, Pierre-Marie

    2014-03-01

    The idea that the Sun was a gaseous in nature was born from 1858-65. At that time, a group of men, including Herbert Spencer, Father Angelo Secchi, Warren de la Rue, Balfour Stewart, and Benjamin Loewy, advanced that the Sun was a ball of gas. In 1865, Hervé Faye was the first to argue that the solar surface was merely an illusion. Dismissing all signs to the contrary, solar physics has promoted this idea to the present day, as manifested by the Standard Solar Model. In this work, overwhelming observational evidence will be presented that the Sun does indeed possess a distinct surface (see P.M. Robitaille, Forty Lines of Evidence for Condensed Matter -- The Sun on Trial: Liquid Metallic Hydrogen as a Solar Building Block, Progress in Physics, 2013, v. 4, 90-143). Our telescopes and satellites are sampling real structures on the surface of the Sun.

  1. Exotic World Blisters Under the Sun

    Science.gov (United States)

    2006-01-01

    This artist's concept shows a Jupiter-like planet soaking up the scorching rays of its nearby 'sun.' NASA's Spitzer Space Telescope used its heat-seeking infrared eyes to figure out that a gas-giant planet like the one depicted here is two-faced, with one side perpetually in the cold dark, and the other forever blistering under the heat of its star. The illustration portrays how the planet would appear to infrared eyes, showing temperature variations across its surface. The planet, called Upsilon Andromedae b, was first discovered in 1996 around the star Upsilon Andromedae, located 40 light-years away in the constellation Andromeda. This star also has two other planets orbiting farther out. Upsilon Andromedae b is what's known as a 'hot-Jupiter' planet, because it is made of gas like our Jovian giant, and it is hot, due to its tight, 4.6-day-long jaunt around its star. The toasty planet orbits at one-sixth the distance of Mercury from our own sun. It travels in a plane that is seen neither edge- nor face-on from our solar system, but somewhere in between. Scientists do not know how fast Upsilon Andromedae b is spinning on its axis, but they believe that it is tidally locked to its star, just as our locked moon forever hides its 'dark side' from Earth's view. Spitzer observed Upsilon Andromedae b at five points during the planet's trip around its star. The planet's light levels went up or down, as detected by Spitzer, depending on whether the planet's sunlit or dark side was pointed toward Earth. These data indicate that the temperature difference between the two hemispheres of the planet is about 1,400 degrees Celsius (2,550 degrees Fahrenheit). According to astronomers, this means that the side of the planet that faces the star is always as hot as lava, while the other side could potentially be as cold as ice. Specifically, the hot side of the planet ranges from about 1,400 to 1,650 degrees Celsius (2,550 to 3,000 degrees Fahrenheit), and the cold side from about

  2. The risks and benefits of sun exposure 2016

    Science.gov (United States)

    Hoel, David G.; Berwick, Marianne; de Gruijl, Frank R.

    2016-01-01

    ABSTRACT Public health authorities in the United States are recommending that men, women and children reduce their exposure to sunlight, based on concerns that this exposure will promote skin cancer. On the other hand, data show that increasing numbers of Americans suffer from vitamin D deficiencies and serious health problems caused by insufficient sun exposure. The body of science concerning the benefits of moderate sun exposure is growing rapidly, and is causing a different perception of sun/UV as it relates to human health. Melanoma and its relationship to sun exposure and sunburn is not adequately addressed in most of the scientific literature. Reports of favorable health outcomes related to adequate serum 25(OH)D concentration or vitamin D supplementation have been inappropriately merged, so that benefits of sun exposure other than production of vitamin D are not adequately described. This review of recent studies and their analyses consider the risks and benefits of sun exposure which indicate that insufficient sun exposure is an emerging public health problem. This review considers the studies that have shown a wide range health benefits from sun/UV exposure. These benefits include among others various types of cancer, cardiovascular disease, Alzheimer disease/dementia, myopia and macular degeneration, diabetes and multiple sclerosis. The message of sun avoidance must be changed to acceptance of non-burning sun exposure sufficient to achieve serum 25(OH)D concentration of 30 ng/mL or higher in the sunny season and the general benefits of UV exposure beyond those of vitamin D. PMID:27942349

  3. Knowledge and Practice of Sun Protection in Schools in South Africa Where No National Sun Protection Programme Exists

    Science.gov (United States)

    Wright, Caradee Y.; Reeder, Anthony I.; Albers, Patricia N.

    2016-01-01

    Interventions in primary schools that increase sun-protective behaviours and decrease ultraviolet radiation exposure, sunburn incidence and skin cancer risk can be effective. SunSmart School Accreditation Programmes (SSAP) are recommended. Prior to SSAP implementation in South Africa, we explored the feasibility of obtaining national baseline…

  4. Interstellar Clouds Near the Sun, III

    Science.gov (United States)

    Frisch, Priscilla C.

    We propose to continue a study of interstellar sight-lines with low total column densities in order to determine the nature (temperature, density, fractional ionization) of the low density gas near the Sun and within the interior of the local superbubble. IUE data, combined with previous Copernicus observations, can be used to delimit the filling factor of nearby low density warm gas, and by default restrict the filling factor of 10^6 K plasma. In the proposed program, observations of MgI and ZnII(and in one region CIV) are combined with cloud maps and ground-based NaI observations (from a separate program) to restrict gas temperature, spatial and electron densities. The Welty et al. (1986) technique for removing fixed pattern noise through observations of a template star (used to flat-field the target stars on a pixel-by-pixel basis) is used to enable 3sigma absorption line detections at the 6-9 mA level, depending on the number of exposures involved. The ultimate goal of both the IUE and ground-based program is to map out the local interstellar medium. Apart from the intrinsic interest of this problem, it will help define regions where ultraviolet sources can be observed with FUSE/Lyman at lambda<912 A.

  5. The Chemical Composition of the Sun

    Science.gov (United States)

    Asplund, Martin; Grevesse, Nicolas; Sauval, A. Jacques; Scott, Pat

    2009-09-01

    The solar chemical composition is an important ingredient in our understanding of the formation, structure, and evolution of both the Sun and our Solar System. Furthermore, it is an essential reference standard against which the elemental contents of other astronomical objects are compared. In this review, we evaluate the current understanding of the solar photospheric composition. In particular, we present a redetermination of the abundances of nearly all available elements, using a realistic new three-dimensional (3D), time-dependent hydrodynamical model of the solar atmosphere. We have carefully considered the atomic input data and selection of spectral lines, and accounted for departures from local thermodynamic equilibrium (LTE) whenever possible. The end result is a comprehensive and homogeneous compilation of the solar elemental abundances. Particularly noteworthy findings are significantly lower abundances of C, N, O, and Ne compared to the widely used values of a decade ago. The new solar chemical composition is supported by a high degree of internal consistency between available abundance indicators, and by agreement with values obtained in the Solar Neighborhood and from the most pristine meteorites. There is, however, a stark conflict with standard models of the solar interior according to helioseismology, a discrepancy that has yet to find a satisfactory resolution.

  6. Framing the Sun and Buildings as Commons

    Directory of Open Access Journals (Sweden)

    Jeffrey R. S. Brownson

    2013-09-01

    Full Text Available This study frames integration of Solar Energy Conversion Systems (SECS with the built environment, addressing on-site limitations for resource allocation in the urban context. The Sun, buildings, and solar technologies are investigated as resource systems within Ostrom’s framework of the commons and shared governance, with associated goods (as resource units appropriated from light conversion (products of daylight, heat, power, shade, money. Light is transient and unevenly distributed across the hours of the day across the year. Building surfaces utilized to convert light into useful products such as electricity are often “area-constrained” and cannot provide total power to all occupants in urban structures. Being unevenly distributed over time and being area-constrained makes the appropriated goods from the solar resource system scarce to commercial buildings and multi-family residences. Scarce commodities require management strategies to distribute the variable returns derived from technologies such as PV and solar hot water. The balance between sustainable urban communities and limited surface area to deliver solar products to all occupants will soon drive communities to consider how the solar goods are managed and allocated. Examples demonstrate management of solar resource and associated goods through collective actions of local communities via utility sponsored models, solar gardens, and crowd-sourced investment.

  7. Supersonic Magnetic Flows in the Quiet Sun

    CERN Document Server

    Borrero, J M; Schlichenmaier, R; Schmidt, W; Berkefeld, T; Solanki, S K; Bonet, J A; Iniesta, J C del Toro; Domingo, V; Barthol, P; Gandorfer, A

    2012-01-01

    In this contribution we describe some recent observations of high-speed magnetized flows in the quiet Sun granulation. These observations were carried out with the Imaging Magnetograph eXperiment (IMaX) onboard the stratospheric balloon {\\sc Sunrise}, and possess an unprecedented spatial resolution and temporal cadence. These flows were identified as highly shifted circular polarization (Stokes $V$) signals. We estimate the LOS velocity responsible for these shifts to be larger than 6 km s$^{-1}$, and therefore we refer to them as {\\it supersonic magnetic flows}. The average lifetime of the detected events is 81.3 s and they occupy an average area of about 23\\,000 km$^2$. Most of the events occur within granular cells and correspond therefore to upflows. However some others occur in intergranular lanes or bear no clear relation to the convective velocity pattern. We analyze a number of representative examples and discuss them in terms of magnetic loops, reconnection events, and convective collapse.

  8. Observing the Sun with Coronado telescopes telescopes

    CERN Document Server

    Pugh, Philip

    2007-01-01

    The Sun provides amateur astronomers with one of the few opportunities for daytime astronomy. In order to see the major features of our nearest star, special telescopes that have a very narrow visible bandwidth are essential. The bandwidth has to be as narrow as 1 A- 10-10 m (1 Angstrom) and centred on the absorption line of neutral hydrogen. This makes many major features of the Suna (TM)s chromosphere visible to the observer. Such narrow-band "Fabry-Perot etalon filters" are high technology, and until the introduction of the Coronado range of solar telescopes, were too expensive for amateur use. The entry-level Coronado telescope, the PST (Personal Solar Telescope) costs under 500. Solar prominences (vast columns of plasma, best seen at the edge of the solar disk), filaments, flares, sunspots, plage and active regions are all visible and can be imaged to produce spectacular solar photographs. Philip Pugh has assembled a team of contributors who show just how much solar work can be done with Coronado telesco...

  9. South Australian adolescent ophthalmic sun protective behaviours.

    Science.gov (United States)

    Pakrou, N; Casson, R; Fung, S; Ferdowsi, N; Lee, G; Selva, D

    2008-06-01

    To study student's knowledge of the effects of sunlight on the eyes, as well as their sun protective behaviours. In total, 640 [corrected] students aged 13-18 years were surveyed in South Australia, during August-September 2004, using a standardized previously used survey. Scores were calculated regarding knowledge about ultraviolet light, sunlight effects on eyes, as well as eye and body protection. Risk factor scores were produced for each student. The data were analysed by the analysis of variance (ANOVA), as well as the Cochran-Mantel-Haenszel methods. Results were compared to the same survey conducted in 1995 in Queensland Australia. This group demonstrated a moderate level of knowledge, similar to the 1995 survey. Students in the older age groups demonstrated significantly higher knowledge. The majority of students (74%) owned a pair of sunglasses; however, 44.5% almost never wore their glasses. The reported frequency of wearing sunglasses was significantly related to advertising, believing sunglasses protect the eyes, as well as personal, family, and peer attitudes towards wearing sunglasses. The results of our survey suggest no significant change in knowledge and behaviours of students, compared to the 1995 survey. We feel it is imperative that adolescents be made more aware of the damaging effects of sunlight and the benefits of eye protection. Health promotion campaigns should target the youth and consider that as a group, they are significantly influenced by the media, peers, and family attitudes.

  10. Clouds and the Faint Young Sun Paradox

    CERN Document Server

    Goldblatt, Colin

    2011-01-01

    We investigate the role which clouds could play in resolving the Faint Young Sun Paradox (FYSP). Lower solar luminosity in the past means that less energy was absorbed on Earth (a forcing of -50 Wm-2 during the late Archean), but geological evidence points to the Earth being at least as warm as it is today, with only very occasional glaciations. We perform radiative calculations on a single global mean atmospheric column. We select a nominal set of three layered, randomly overlapping clouds, which are both consistent with observed cloud climatologies and reproduce the observed global mean energy budget of Earth. By varying the fraction, thickness, height and particle size of these clouds we conduct a wide exploration of how changed clouds could affect climate, thus constraining how clouds could contribute to resolving the FYSP. Low clouds reflect sunlight but have little greenhouse effect. Removing them entirely gives a~forcing of +25 Wm-2 whilst more modest reduction in their efficacy gives a forcing of +10 ...

  11. Saturation of Stellar Winds from Young Suns

    CERN Document Server

    Suzuki, Takeru K; Kataoka, Ryuho; Kato, Yoshiaki; Matsumoto, Takuma; Miyahara, Hiroko; Tsuneta, Saku

    2013-01-01

    (Abridged)We investigate mass losses via stellar winds from sun-like main sequence stars with a wide range of activity levels. We perform forward-type magnetohydrodynamical numerical experiments for Alfven wave-driven stellar winds with a wide range of the input Poynting flux from the photosphere. Increasing the magnetic field strength and the turbulent velocity at the stellar photosphere from the current solar level, the mass loss rate rapidly increases at first owing to the suppression of the reflection of the Alfven waves. The surface materials are lifted up by the magnetic pressure associated with the Alfven waves, and the cool dense chromosphere is intermittently extended to 10-20% of the stellar radius. The densities of the corona and transition region above the chromosphere is also high, which leads to efficient radiative losses. Eventually most of the input Poynting energy from the stellar surface escapes by the radiation. As a result, there is no more sufficient energy remained for the kinetic energy...

  12. Sunscreen use and failures--on site observations on a sun-holiday.

    Science.gov (United States)

    Petersen, Bibi; Datta, Pameli; Philipsen, Peter Alshede; Wulf, Hans Christian

    2013-01-01

    With this observation study we aimed to determine how and when sunscreen was used. 20 sun seekers were observed during a one-week sun holiday in Hurghada, Egypt. The sunscreen application thickness was related to part of body, time outdoors, exposure to ultraviolet radiation and to sunburning. Skin sites with sunscreen were exposed to UVR significantly longer and received significantly higher UVR doses than skin sites without sunscreen. They received an average of 0.62 SED [0.0-9.3 SED] (13% of their MED) before the first sunscreen application of the day. The average sunscreen used was SPF15 and the sunscreen application thickness was in average 0.79 mg cm(-)2 giving an approximated effect of SPF3. For different body parts either the total UVR exposure dose or the UVR exposure time and UVR exposure dose before the first sunscreen application were higher for sunburned than non-sunburned skin sites. In the final model gender, skin type and UVR to skin (adjusted for SPF and sunscreen application thickness) were significant predictors of sunburning. The sunscreen application thickness of 0.79 mg cm(-)2 was less than the 2 mg cm(-2) used for testing SPF. The late start of sunscreen use and improper application thickness was ineffective in preventing sunburn, and therefore could not compensate for the risk of prolonged UVR exposure and high UVR doses. Our results lead us to suspect that the protective effect of sunscreen use against DNA-damage, and thereby skin cancer, is minimal the way sunscreen is used under real sun holiday conditions.

  13. Unintended Sunburn: A Potential Target for Sun Protection Messages

    Directory of Open Access Journals (Sweden)

    Geraldine F. H. McLeod

    2017-01-01

    Full Text Available New Zealand (NZ has the highest melanoma incidence rate in the world. Primary prevention efforts focus on reducing sunburn incidence and increasing sun protective practices in the population. However, sunburn from excessive ultraviolet radiation (UVR remains common. To reduce sunburn incidence, it is important to examine those individuals who experience unintended sunburn. This study aims to use data from the NZ Triennial Sun Protection Survey to describe respondents who were not intending to tan but were sunburnt after outdoor UVR exposure. Information on sociodemographics, concurrent weather conditions, sun protection attitudes and knowledge, and outdoor behaviour was also collected. The results showed 13.5% of respondents’ experienced unintended sunburn during the survey weekend but had not attempted to obtain a tan that summer. Respondents who reported unintended sunburn were more likely than others to have been near water and in unshaded areas, used sunscreen, had higher SunSmart knowledge scores, had lower positive attitudes towards tanning, and were outdoors for a longer duration with less body coverage. As sunburn was unintended these respondents’ outdoor sun protective behaviours may be amenable to change. Future public health initiatives should focus on increasing sun protection (clothing and shade and reducing potential barriers to sun protection.

  14. Catastrophic rotational braking among Sun-like stars. A model of the Sun's rotation evolution

    Science.gov (United States)

    Gondoin, P.

    2017-03-01

    Context. Observations of young open clusters show a bimodal distribution of stellar rotation. In those clusters, Sun-like stars group into two main populations of fast and slow rotators. Beyond an age of approximately 600 Myr, the two populations converge towards a single sequence of slow rotators. Aims: The present study addresses the origin of this bimodal distribution and the cause of its observed evolution. Methods: New prescriptions of mass-loss rate and Alfven radius dependences on Rossby number suggested by observations are implemented in a phenomenological model of angular-momentum loss and redistribution. The obtained model is used to calculate the time evolution of a rotation-period distribution of solar-mass stars similar to that observed in the 5 Myr-old NGC 2362 open cluster. The simulated distributions at subsequent ages are compared with those of h Per, the Pleiades, M 50, M 35, and M 37. Results: The model is able to reproduce the appearance and disappearance of a bimodal rotation-period distribution in open clusters providing that a brief episode of large-angular-momentum loss is included in the early evolution of Sun-like stars. Conclusions: I argue that a transitory episode of large-angular-momentum loss occurs on Sun-like stars with Rossby numbers between 0.13 and 0.3. This phenomenon of enhanced magnetic braking by stellar wind would be mainly driven by a rapid increase of mass loss at a critical rotation rate. This scenario accounts for the bimodal distribution of stellar rotation in open clusters with ages between 20-30 Myr and approximately 600 Myr. The mass-loss rate increase could account for a significant fraction of the X-ray luminosity decay of Sun-like stars in the 0.13-0.3 Rossby number range where a transition from the saturated to the non-saturated regime of X-ray emission is observed. Observed correlations between Li abundance and rotation sequences in the Pleiades and M 34 clusters support this scenario.

  15. Traditions of the Sun, One Model for Expanding Audience Access

    Science.gov (United States)

    Hawkins, I.; Paglierani, R.

    2006-12-01

    The Internet is a powerful tool with which to expand audience access, bringing students, teachers and the public to places and resources they might not otherwise visit or make use of. We will present Traditions of the Sun, an experiential Web site that invites exploration of the world's ancient observatories with special emphasis on Chaco Culture National Historic Park in the Four Corners region of the US and several sites in the Yucatan Peninsula in Mexico. Traditions of the Sun includes resources in English and Spanish along with a unique trilingual on-line book, "Traditions of the Sun, A Photographic Journal," containing explanatory text in Yucatec Maya as well. Traditions of the Sun offers rich opportunities for virtual visits to ancient sites used for solar observing while learning about current NASA research on the Sun and indigenous solar practices within a larger historical and cultural context. The site contains hundreds of photographs, historic images and rich multimedia to help tell the story of the Sun-Earth Connection. Visitors to the site can zoom in on the great Mayan cities of Chichen Itza, Uxmal, Dzibilchaltun, and Mayapan to learn about Mayan astronomy, history, culture, and science. They can also visit Chaco Canyon to watch sunrise over Pueblo Bonito on the summer solstice, take a virtual reality tour of the great kiva at Casa Rinconada or see panoramic vistas from Fajada Butte, an area which, for preservation purposes, is restricted to the public. Traditions of the Sun provides one model of how exploration and discovery can come to life for both formal and informal audiences via the Internet. Traditions of the Sun is a collaborative project between NASA's Sun-Earth Connection Education Forum, the National Park Service, Instituto National de Antropologia e Historia, Universidad Nacional Autonoma de Mexico, and Ideum.

  16. THE UBV(RI){sub C} COLORS OF THE SUN

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez, I. [McDonald Observatory and Department of Astronomy, University of Texas at Austin, 1 University Station, C1400 Austin, TX 78712-0259 (United States); Michel, R.; Schuster, W. J. [Observatorio Astronomico Nacional, Universidad Nacional Autonoma de Mexico, Apartado Postal 877, Ensenada, B.C., CP 22800 (Mexico); Sefako, R.; Van Wyk, F. [South African Astronomical Observatory, P.O. Box 9, Observatory 7935, Cape Town (South Africa); Tucci Maia, M. [UNIFEI, DFQ-Instituto de Ciencias Exatas, Universidade Federal de Itajuba, Itajuba MG (Brazil); Melendez, J. [Departamento de Astronomia do IAG/USP, Universidade de Sao Paulo, Rua do Matao 1226, Sao Paulo, 05508-900 SP (Brazil); Casagrande, L. [Max-Planck-Institut fuer Astrophysik, Karl-Schwarzschild-Str. 1, Postfach 1317, D-85741 Garching (Germany); Castilho, B. V. [Laboratorio Nacional de Astrofisica/MCT, Rua Estados Unidos 154, 37504-364 Itajuba, MG (Brazil)

    2012-06-10

    Photometric data in the UBV(RI){sub C} system have been acquired for 80 solar analog stars for which we have previously derived highly precise atmospheric parameters T{sub eff}, log g, and [Fe/H] using high-resolution, high signal-to-noise ratio spectra. UBV and (RI){sub C} data for 46 and 76 of these stars, respectively, are published for the first time. Combining our data with those from the literature, colors in the UBV(RI){sub C} system, with {approx_equal} 0.01 mag precision, are now available for 112 solar analogs. Multiple linear regression is used to derive the solar colors from these photometric data and the spectroscopically derived T{sub eff}, log g, and [Fe/H] values. To minimize the impact of systematic errors in the model-dependent atmospheric parameters, we use only the data for the 10 stars that most closely resemble our Sun, i.e., the solar twins, and derive the following solar colors: (B - V){sub Sun} = 0.653 {+-} 0.005, (U - B){sub Sun} = 0.166 {+-} 0.022, (V - R){sub Sun} = 0.352 {+-} 0.007, and (V - I){sub Sun} = 0.702 {+-} 0.010. These colors are consistent, within the 1{sigma} errors, with those derived using the entire sample of 112 solar analogs. We also derive the solar colors using the relation between spectral-line-depth ratios and observed stellar colors, i.e., with a completely model-independent approach, and without restricting the analysis to solar twins. We find (B - V){sub Sun} = 0.653 {+-} 0.003, (U - B){sub Sun} = 0.158 {+-} 0.009, (V - R){sub Sun} = 0.356 {+-} 0.003, and (V - I){sub Sun} = 0.701 {+-} 0.003, in excellent agreement with the model-dependent analysis.

  17. CUNY Sun-Earth Research, Space Climate

    Science.gov (United States)

    Cotten, D. E.; Cheung, T. D.; Marchese, P. J.; Johnson, L. P.; Austin, S.; Tremberger, G.

    2007-05-01

    Faculty and students at Queensborough Community College and Medgar Evers College of the City University of New York (CUNY) have, over several years now, employed simple software familiar to most undergraduate students to perform useful calculations, including statistical analyses, regarding various geophysical phenomena. Topics have included Space Weather, Interplanetary Magnetic Field (IMF) direction and strength fluctuations, geomagnetic and ionospheric responses to solar flares, and Coronal Mass Ejection (CME) events. Our statistical analyses have utilized second-order measures of fluctuation of the IMF strength, especially what we now call the Cheung number: the number of times that the value of Sigma-B, as provided by the ACE (Advanced Composition Explorer) data, has exceeded 0.5nT during a 6 hour interval. We have also utilized the Higuchi fractal dimension of various somewhat random fluctuations, including Sigma-B and the brightness or strength of adjacent pixels or data points in somewhat random data sequences in time or spatial dimension, including IMF fluctuations and SOHO (Solar Heliographic Observer) images of the Sun. These we have correlated with each other and with such variables as SEP (Solar Energetic Particle) peak flux, TEC (Total Electron Content) of the ionosphere, and Dst (Disturbance storm-time) in the geomagnetic field. Recent results indicate that the IMF fluctuation measures are well correlated with the SEP peak flux, the Dst, and TEC. Higuchi fractal analysis of SOHO photospheric ultraviolet brightness indicates, consistent with concomitant increased chaos or randomness of photospheric brightness, an increased likelihood of solar flare events or CME affecting interplanetary space and the earth's magnetosphere/ionosphere/atmosphere.

  18. AsteroFLAG - from the Sun to the stars

    Energy Technology Data Exchange (ETDEWEB)

    Chaplin, W J; Elsworth, Y [School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham, B15 2TT (United Kingdom); Appourchaux, T; Baudin, F [Institut d' Astrophysique Spatiale (IAS), Batiment 121, F-91405, Orsay Cedex (France); Arentoft, T; Christensen-Dalsgaard, J; Kjeldsen, H [Department of Physics and Astronomy, University of Aarhus, DK-8000 Aarhus C (Denmark); Ballot, J [Max-Planck-Institut fuer Astrophysik, Karl-Schwarzschild-Str. 1, Postfach 1317, 85741, Garching (Germany); Bazot, M [Centro de AstrofIsica Universidade do Porto, 4150-762 Porto (Portugal); Bedding, T R [School of Physics, University of Sydney, Sydney, NSW 2006 (Australia); Creevey, O L [High Altitude Observatory, National Center for Atmospheric Research, Boulder, CO 80301 (United States); Duez, V; Garcia, R A [DAPNIA/CEA, CE Saclay, FR-91191 Gif-sur-Yvette Cedex (France); Fletcher, S T [Faculty of Arts, Computing, Engineering and Sciences, Sheffield Hallam University, Sheffield S1 1WB (United Kingdom); Gough, D O; Houdek, G [Institute of Astronomy, University of Cambridge, Cambridge CB3 0HA (United Kingdom); Jimenez, A; Jimenez-Reyes, S J [Instituto de Astrofisica de Canarias, E-38200, La Laguna, Tenerife (Spain); Lazrek, M [LPHEA, Faculte des Sciences Semlalia, Universite Cadi Ayyad, Marrakech (Morocco); Leibacher, J W, E-mail: w.j.chaplin@bham.ac.uk (and others)

    2008-10-15

    We stand on the threshold of a critical expansion of asteroseismology of Sun-like stars, the study of stellar interiors by observation and analysis of their global acoustic modes of oscillation. The Sun-like oscillations give a very rich spectrum allowing the internal structure and dynamics to be probed down into the stellar cores to very high precision. Asteroseismic observations of many stars will allow multiple-point tests of crucial aspects of stellar evolution and dynamo theory. The aims of the asteroFLAG collaboration are to help the community to refine existing, and to develop new, methods for analysis of the asteroseismic data on the Sun-like oscillators.

  19. On the Observations of the Sun in Polynesia

    CERN Document Server

    Rjabchikov, Sergei

    2014-01-01

    The role of the Polynesian sun god Tagaloa has been studied. The Polynesian characters Maui-tikitiki, Tane and Tiki were related to the sun as well. The solar data of Easter Island are essential indeed. The rongorongo text on the Santiago staff about the solar eclipse of December 20, 1805 A.D. has been decoded. The Mataveri calendar was probably incised on a rock in 1775 A.D. So, a central event during the bird-man festval was the day of vernal equinox. The priests-astronomers watched not only the sun and the moon, but also some stars of the zodiacal constellations and other bright stars.

  20. Spacecraft Attitude Determination with Earth Albedo Corrected Sun Sensor Measurements

    DEFF Research Database (Denmark)

    Bhanderi, Dan

    This thesis focuses on advanced modeling of the Earth albedo experienced by satellites in Earth orbit. The model of the Earth albedo maintains directional information of the Earth albedo irradiance from each partition on the Earth surface. This allows enhanced modeling of Sun sensor current outputs......-Method, Extended Kalman Filter, and Unscented Kalman Filter algorithms are presented and the results are compared. Combining the Unscented Kalman Filter with Earth albedo and enhanced Sun sensor modeling allows for three-axis attitude determination from Sun sensor only, which previously has been perceived...

  1. Human eye and the sun hot and cold light

    CERN Document Server

    Vavilov, S I

    1965-01-01

    The Human Eye and the Sun, """"Hot"""" and """"Cold"""" Light is a translation from the Russian language and is a reproduction of texts from Volume IV of S.I. Vavilov, president of the U.S.S.R. Academy of Sciences. The book deals with theoretical and practical developments in lighting techniques. The text gives a brief introduction on the relationship of the human eye and the sun, describing the properties of light, of the sun, and of the human eye. The book describes hot (incandescence) and cold light (luminescence) as coming from different sources. These two types of light are compared. The

  2. System modeling based measurement error analysis of digital sun sensors

    Institute of Scientific and Technical Information of China (English)

    WEI; M; insong; XING; Fei; WANG; Geng; YOU; Zheng

    2015-01-01

    Stringent attitude determination accuracy is required for the development of the advanced space technologies and thus the accuracy improvement of digital sun sensors is necessary.In this paper,we presented a proposal for measurement error analysis of a digital sun sensor.A system modeling including three different error sources was built and employed for system error analysis.Numerical simulations were also conducted to study the measurement error introduced by different sources of error.Based on our model and study,the system errors from different error sources are coupled and the system calibration should be elaborately designed to realize a digital sun sensor with extra-high accuracy.

  3. Balloon-Borne System Would Aim Instrument Toward Sun

    Science.gov (United States)

    Polites, M. E.

    1992-01-01

    Proposed system including digital control computer, control sensors, and control actuators aims telescope or other balloon-borne instrument toward Sun. Pointing system and instrument flown on gondola, suspended from balloon. System includes reaction wheel, which applies azimuthal control torques to gondola, and torque motor to apply low-frequency azimuthal torques between gondola and cable. Three single-axis rate gyroscopes measure yaw, pitch, and roll. Inclinometer measures roll angle. Two-axis Sun sensor measures deviation, in yaw and pitch, of attitude of instrument from line to apparent center of Sun. System provides initial coarse pointing, then maintains fine pointing.

  4. Outdoor Workers and Sun Protection: Knowledge and Behaviour

    Directory of Open Access Journals (Sweden)

    Jane Cioffi

    2012-11-01

    Full Text Available Outdoor workers are at high risk of developing skin cancer. Primary prevention can potentiallyreduce the incidence of skin cancer in this group. This study aimed to determine theknowledge and sun protective behaviour of outdoor workers towards skin cancer. A shortquestionnaire was used to collect data from workers on construction sites during workinghours. Despite workers having knowledge of the risks of skin cancer their use of sun protectionwas less than satisfactory, particularly considering their cumulative exposure.Workplace health education programs for outdoor workers addressing sun protection areindicated, as is further research to increase understanding of issues workers have withsun protection in the workplace.

  5. The Iconography and Symbolism of Sun God in Urartian Art

    Science.gov (United States)

    Poghosyan, Gayane

    2016-12-01

    The predominating symbol of the winged sun disc in Urartian religious iconography testifies the significant role and importance of the sun in worship. The stylistic variation and peculiar iconographic features of the winged discs, sacred animals and divine images associated with solar deity shows the relationship between the cult of the sun god, sequence of the different phases of the year and constellations in Urartian culture. Such kind of iconography is possibly formed and stylized in result of interaction of ancient human imaginations, influence of rock paintings and religious beliefs.

  6. Study of Black Consciousness in A Raisin in The Sun

    Directory of Open Access Journals (Sweden)

    Rehana Kousar

    2014-07-01

    Full Text Available This work explores Black Consciousness in A Raisin in the Sun by Hansberry. Black Consciousness elaborates an awareness of and pride in one’s identity as a black person. It analyzes A Raisin in the Sun by applying the theory of Black Consciousness under the perspective of Fanon. This study analysis the drama at three levels: sense of pride on black culture and identity, struggle against Apartheid and Blacks’ resolution to accept the challenges of White Community. Keywords: Black Consciousness, Apartheid, Identity, Culture, A Raisin in the Sun, cross – cultural studies, diasporic, African Literature

  7. The Maunder minimum and the variable sun-earth connection

    CERN Document Server

    Wei Hock Soon, Willie

    2003-01-01

    This book takes an excursion through solar science, science history, and geoclimate with a husband and wife team who revealed some of our sun's most stubborn secrets. E Walter and Annie S D Maunder's work helped in understanding our sun's chemical, electromagnetic and plasma properties. They knew the sun's sunspot migration patterns and its variable, climate-affecting, inactive and active states in short and long time frames. An inactive solar period starting in the mid-seventeenth century lasted approximately seventy years, one that E Walter Maunder worked hard to make us understand: the Maun

  8. Nearest star the surprising science of our sun

    CERN Document Server

    Golub, Leon

    2014-01-01

    How did the Sun evolve, and what will it become? What is the origin of its light and heat? How does solar activity affect the atmospheric conditions that make life on Earth possible? These are the questions at the heart of solar physics, and at the core of this book. The Sun is the only star near enough to study in sufficient detail to provide rigorous tests of our theories and help us understand the more distant and exotic objects throughout the cosmos. Having observed the Sun using both ground-based and spaceborne instruments, the authors bring their extensive personal experience to this sto

  9. Milne-Eddington inversions of high resolution observations of the quiet Sun

    CERN Document Server

    Suárez, D Orozco; Vögler, A; Iniesta, J C Del Toro

    2010-01-01

    The physical conditions of the solar photosphere change on very small spatial scales both horizontally and vertically. Such a complexity may pose a serious obstacle to the accurate determination of solar magnetic fields. We examine the applicability of Milne-Eddington (ME) inversions to high spatial resolution observations of the quiet Sun. Our aim is to understand the connection between the ME inferences and the actual stratifications of the atmospheric parameters. We use magnetoconvection simulations of the solar surface to synthesize asymmetric Stokes profiles such as those observed in the quiet Sun. We then invert the profiles with the ME approximation. We perform an empirical analysis of the heights of formation of ME measurements and analyze the uncertainties brought about by the ME approximation. We also investigate the quality of the fits and their relationship with the model stratifications. The atmospheric parameters derived from ME inversions of high-spatial resolution profiles are reasonably accur...

  10. Shift control method for the local time at descending node based on sun-synchronous orbit satellite

    Institute of Scientific and Technical Information of China (English)

    Yang Yong'an; Feng Zuren; Sun Linyan; Tan Wei

    2009-01-01

    This article analyzes the shift factors of the descending node local time for sun-synchronous satellites and proposes a shift control method to keep the local time shift within an allowance range. It is found that the satellite orbit design and the orbit injection deviation are the causes for the initial shift velocity, whereas the atmospheric drag and the sun gravitational perturbation produce the shift acceleration. To deal with these shift factors, a shift control method is put forward, through such methods as orbit variation design, orbit altitude, and inclination keeping control. The simulation experiment and practical application have proved the effectiveness of this control method.

  11. Two Sun-like Superflare Stars Rotating as Slow as the Sun

    CERN Document Server

    Nogami, Daisaku; Honda, Satoshi; Maehara, Hiroyuki; Notsu, Shota; Shibayama, Takuya; Shibata, Kazunari

    2014-01-01

    We report on the results of high dispersion spectroscopy of two `superflare stars', KIC 9766237, and KIC 9944137 with Subaru/HDS. Superflare stars are G-type main sequence stars, but show gigantic flares compared to the Sun, which have been recently discovered in the data obtained with the Kepler spacecraft. Though most of these stars are thought to have a rotation period shorter than 10 days on the basis of photometric variabilities, the two targets of the present paper are estimated to have a rotation period of 21.8 d, and 25.3 d. Our spectroscopic results clarified that these stars have stellar parameters similar to those of the Sun in terms of the effective temperature, surface gravity, and metallicity. The projected rotational velocities derived by us are consistent with the photometric rotation period, indicating a fairy high inclination angle. The average strength of the magnetic field on the surface of these stars are estimated to be 1-20 G, by using the absorption line of Ca II 8542. We could not det...

  12. Sun, the Earth, and Near-Earth Space: A Guide to the Sun-Earth System

    Science.gov (United States)

    Eddy, John A.

    2010-01-01

    In a world of warmth and light and living things we soon forget that we are surrounded by a vast universe that is cold and dark and deadly dangerous, just beyond our door. On a starry night, when we look out into the darkness that lies around us, the view can be misleading in yet another way: for the brightness and sheer number of stars, and their chance groupings into familiar constellations, make them seem much nearer to each other, and to us, that in truth they are. And every one of them--each twinkling, like a diamond in the sky--is a white-hot sun, much like our own. The nearest stars in our own galaxy--the Milky Way-- are more than a million times further away from us than our star, the Sun. We could make a telephone call to the Moon and expect to wait but a few seconds between pieces of a conversation, or but a few hours in calling any planet in our solar system.

  13. Sunscreen use related to UV exposure, age, sex, and occupation based on personal dosimeter readings and sun-exposure behavior diaries.

    Science.gov (United States)

    Thieden, Elisabeth; Philipsen, Peter A; Sandby-Møller, Jane; Wulf, Hans Christian

    2005-08-01

    To examine during what behaviors people apply sunscreen and to assess the relationship to UV exposure monitored by personal dosimetry and diaries. Open prospective observational study. University hospital. A convenience sample of 340 Danish volunteers: children, adolescents, indoor workers, sun worshippers, golfers, and gardeners (age range, 4-68 years). Intervention Subjects recorded sunscreen use and sun-exposure behavior in diaries and carried personal, electronic UV dosimeters, measuring time-stamped UV doses continuously, during a median of 119 days covering 346 sun-years (1 sun-year equals 1 subject participating during 1 summer season). Associations between sunscreen use and age, sex, skin type, occupation, sunburn, UV exposure doses, and behavior; and adequate application density and sun protection factor required to prevent sunburn. There were great variations in sunscreen use, which was highly correlated with risk behavior (sunbathing or exposing the upper body) (r = 0.39; P<.001). Sunscreens were used on a median of 5 days per sun-year (range, 1 day for gardeners to 16 days for sun worshippers). Ten percent of females and 41% of males never used sunscreens. Females used sunscreens more but also had more unprotected risk behavior than males (8 days vs 4 days; P<.001). Sunscreen use was not correlated with age, and children had as much unprotected risk behavior as adults. Sunscreens were used on 86% of the days with risk behavior in southern Europe vs 20% in northern Europe (P<.001). The UV doses were significantly higher on days with sunscreen (P< or = .03) and on sunburn days (P<.001). The median sun protection factor was 10.5. The sun-protecting effect corresponded to an application density of 0.5 mg/cm2. Days with sunscreen correlated not with days without risk behavior, but with days "sunbathing with the intention to tan," indicating that sunscreens were used as tanning aids to avoid sunburn.

  14. Low Frequency Radio Emission from the 'Quiet' Sun

    Indian Academy of Sciences (India)

    R. Ramesh

    2000-09-01

    We present observations of the 'quiet' Sun close to the recent solar minimum (Cycle 22), with the Gauribidanur radioheliograph. Our main conclusion is that coronal streamers also influence the observed radio brightness temperature.

  15. On Sun-to-Earth Propagation of Coronal Mass Ejections

    CERN Document Server

    Liu, Ying D; Lugaz, Noé; Möstl, Christian; Davies, Jackie A; Bale, Stuart D; Lin, Robert P

    2013-01-01

    We investigate how coronal mass ejections (CMEs) propagate through, and interact with, the inner heliosphere between the Sun and Earth, a key question in CME research and space weather forecasting. CME Sun-to-Earth kinematics are constrained by combining wide-angle heliospheric imaging observations, interplanetary radio type II bursts and in situ measurements from multiple vantage points. We select three events for this study, the 2012 January 19, 23, and March 7 CMEs. Different from previous event studies, this work attempts to create a general picture for CME Sun-to-Earth propagation and compare different techniques for determining CME interplanetary kinematics. Key results are obtained concerning CME Sun-to-Earth propagation. Our comparison between different techniques (and data sets) also has important implications for CME observations and their interpretations. Future CME observations and space weather forecasting are discussed based on these results. See detail in the PDF.

  16. Some Melanoma Survivors Still Seek Out the Sun

    Science.gov (United States)

    ... https://medlineplus.gov/news/fullstory_163887.html Some Melanoma Survivors Still Seek Out the Sun 1 in ... Even after surviving the potentially deadly skin cancer melanoma, some people continue to go out in the ...

  17. A New Way that Planets can Affect the Sun

    Science.gov (United States)

    Wolff, Charles; Patrone, Paul

    2010-01-01

    As planets orbit the Sun, the Sun also has to move to keep the total momentum of the solar system constant. The Sun's small orbital motion plus its 25 day rotation about its axis combine to invigorate some solar instabilities. Occasional convection cells at the proper phase in their short life can be strengthened by factors of two or more. This local burst of extra kinetic energy eventually reaches the surface where it can increase the intensity of solar activity. It might explain some reports in the last century of how planetary positions correlate with solar activity. This is the first effect of planets that is large enough to cause a significant response on the Sun.

  18. Science Experimenter: Observing the Sun and Solar Eclipses.

    Science.gov (United States)

    Mims, Forrest M., III

    1991-01-01

    Describes the construction and use of simple optical aids that allow the amateur scientist to safely observe sunspots and solar eclipses and also to measure the sun's rotation. (five references) (JJK)

  19. A Short Proof to Some Results of Sun and Wang

    Institute of Scientific and Technical Information of China (English)

    Wei Cao

    2007-01-01

    We give a short proof to some results of Sun and Wang on counting the number of solutions of a class of equations over finite fields. Our proof is elementary and only based on matrix properties and recursion techniques.

  20. 'Eye Freckles' May Predict Sun-Related Problems

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_167479.html 'Eye Freckles' May Predict Sun-Related Problems The spots ... on the iris -- the colored part of the eye -- aren't cancerous, but these "eye freckles" could ...

  1. With Summer Sun Comes Heightened Skin Cancer Risk

    Science.gov (United States)

    ... fullstory_166481.html With Summer Sun Comes Heightened Skin Cancer Risk Doctor shares tips for prevention, recognition To ... skies comes a warning to protect yourself from skin cancer. "Skin cancer, like all types of cancer, is ...

  2. Comparative analysis of the quasi-similar structures on the dynamic spectra of the Sun and Jupiter

    Science.gov (United States)

    Litvinenko, G.; Konovalenko, A.; Zakharenko, V.; Vinogradov, V.; Dorovsky, V.; Melnik, V.; Brazhenko, A.; Shaposhnikov, V.; Rucker, H. O.; Zarka, Ph.

    2014-04-01

    In many literary sources planet Jupiter called the Sun, which is not fully developed. It should be partially confirmed by the experimental fact that the quasisimilar in shape features appear in the dynamic spectra both in the Sun and the Jovian radio emission. The comparative analysis of the similar properties in the emission spectra of Jupiter and the Sun and analogy between the plasma processes in the solar corona and magnetosphere of Jupiter can allow also define the similar features in the radiation mechanisms of these cosmic objects. One of the promising approaches to investigating features of the Jovian DAM emission and the decameter solar radiation is application of novel experimental techniques with a further detailed analysis of the obtained data.

  3. Towards label-free evaluation of oxidative stress in human skin exposed to sun filters (Conference Presentation)

    Science.gov (United States)

    Osseiran, Sam; Wang, Hequn; Suita, Yusuke; Roider, Elisabeth; Fisher, David E.; Evans, Conor L.

    2016-02-01

    Skin cancer, including basal cell carcinoma, squamous cell carcinoma, and melanoma, is the most common form of cancer in North America. Paradoxically, skin cancer incidence is steadily on the rise even despite the growing use of sunscreens over the past decades. One potential explanation for this discrepancy involves the sun filters in sunscreen, which are responsible for blocking harmful ultraviolet radiation. It is proposed that these agents may produce reactive oxygen species (ROS) at the site of application, thereby generating oxidative stress in skin that gives rise to genetic mutations, which may explain the rising incidence of skin cancer. To test this hypothesis, ex vivo human skin was treated with five common chemical sun filters (avobenzone, octocrylene, homosalate, octisalate, and oxybenzone) as well as two physical sun filters (zinc oxide compounds), both with and without UV irradiation. To non-invasively evaluate oxidative stress, two-photon excitation fluorescence (2PEF) and fluorescence lifetime imaging microscopy (FLIM) of the skin samples were used to monitor levels of NADH and FAD, two key cofactors in cellular redox metabolism. The relative redox state of the skin was assessed based on the fluorescence intensities and lifetimes of these endogenous cofactors. While the sun filters were indeed shown to have a protective effect from UV radiation, it was observed that they also generate oxidative stress in skin, even in the absence of UV light. These results suggest that sun filter induced ROS production requires more careful study, especially in how these reactive species impact the rise of skin cancer.

  4. 基于太阳光谱的FTIR技术监测石油化工区丙烯的浓度分布%Application of Fourier Transform Infrared Spectroscopy Based on Sun Spectrum to Monitor the Distribution of Propylene from Petrochemical Industry

    Institute of Scientific and Technical Information of China (English)

    冯书香; 徐亮; 高闽光; 程巳阳; 金岭; 冯明春; 李相贤

    2012-01-01

    In the paper, a new method is introduced for real-time monitoring the column concentration of propylene from petrochemical industry, which is based on the technique of Fourier Transform Infrared Spectroscopy (FTIR) by using sun spectrum. The retrieval algorithm of the concentrations of polluted gases based on nonlinear least squares is proposed. Continuous measurements surrounding the pre-monitoring contaminated areas are performed with a closed loop by using self-developed vehicular FTIR system to obtain the regional background reference spectrum, measured spectrum ,while application of a simplified gas radiative transmission model to calculate atmospheric transmittance spectrum, and finally using the nonlinear least squares fitting algorithm for atmospheric transmittance spectrum to achieve the column concentration of propylene surrounding polluted areas. Using this method, remote sensing experiment of propylene in Shanghai Gaoqiao petrochemical zone was done. The experimental result shows that the measured column concentration distribution of propylene well reflects the pollutantD emission and dispersion and proves the availability of the vehicular FTIR technology in monitoring regional gas pollution.%介绍了一种基于太阳光谱的傅里叶变换红外光谱( FTIR)技术实时监测石油化工区丙烯浓度分布情况的新方法和非线性最小二乘法反演污染气体浓度的算法.利用自主研发的车载FTIR系统对预监测污染源区域做闭合环路测量获取背景参考谱、测量谱,同时应用气体辐射传输的简化模型计算得到大气透过率谱,最终应用非线性最小二乘拟合算法对大气透过率谱反演得出污染源区域周边污染气体分布的柱浓度信息.运用此方法实际遥测了上海高桥石油化工区丙烯排放的情况,实验结果显示,测量的丙烯柱浓度分布准确地反应了污染物的排放和扩散情况,证明了车载FTIR技术在区域性污染气体监测方面的实用性.

  5. Sunscreen Keeps People Out In Dangerous Sun

    Institute of Scientific and Technical Information of China (English)

    Maggie; Fox; 陈鸣煜

    1999-01-01

    本文最吸引读者、最值得回味的是标题。其含义和主题句一致,彼此呼应。但是,标题更简洁、更精彩,它是一句具有拟人色彩的非人称主语句(ImpersonalSubject Sentence)。标题是否可译为:防晒露将人们置于“毒日”之下! 防晒霜的作用本来是 shield people from the sun’s burning rays。 然而,为什么 people who use sunscreen have higher rates of skin cancer andalso develop more moles(痣). which can become cancerous(致癌的)? 值得好好研究!原来,原因之一是防晒霜使用者的微妙的心理在起作用: …people feel a false sense of security when they use sunscreen. 另一个原因是:本来只能使用4次的一瓶防晒霜,不少人却使用了整整一个夏季。自然, 防晒霜就没有能够发挥其作用。为此,作者出语诙谐: Sunscreen should be something on your weekly or monthly grocery list. 文章的末句是: People should be warned to avoid the sun,period, and told sunscreen is foruse when they have to be out,she added. 其中出现的period不是名词,而是感叹词。它常用于美国口语,意思是:就是这么回事。用于叙述事实或看法后表示强调。另如: I could have prevented them,and I didn’t.Period. 我本可以拦住?

  6. Grid Modeling for the SunShot Vision Study

    Energy Technology Data Exchange (ETDEWEB)

    Brinkman, G.; Denholm, P.; Drury, E.; Ela, E.; Mai, T.; Margolis, R.; Mowers, M.

    2012-02-01

    This document describes the use of production cost modeling in the SunShot Vision study, including methods used to create the SunShot Vision scenarios, their implementation in the Gridview model, and assumptions regarding transmission system and operation of each generator type. It also describes challenges and limitations of modeling solar generation technologies in production cost models, and suggests methods for improving their representation in current models.

  7. Tactile Sun: Bringing an Invisible Universe to the Visually Impaired

    Science.gov (United States)

    Isidro, G. M.; Pantoja, C. A.

    2014-07-01

    A tactile model of the Sun has been created as a strategy for communicating astronomy to the blind or visually impaired, and as a useful outreach tool for general audiences. The model design was a collaboration between an education specialist, an astronomy specialist and a sculptor. The tactile Sun has been used at astronomy outreach events in Puerto Rico to make activities more inclusive and to increase public awareness of the needs of those with disabilities.

  8. Exact solution of an su(n) spin torus

    CERN Document Server

    Hao, Kun; Li, Guang-Liang; Yang, Wen-Li; Shi, Kangjie; Wang, Yupeng

    2016-01-01

    The trigonometric su(n) spin chain with anti-periodic boundary condition (su(n) spin torus) is demonstrated to be Yang-Baxter integrable. Based on some intrinsic properties of the R-matrix, certain operator product identities of the transfer matrix are derived. These identities and the asymptotic behavior of the transfer matrix together allow us to obtain the exact eigenvalues in terms of an inhomogeneous T-Q relation via the off-diagonal Bethe Ansatz.

  9. Exact solution of an su(n) spin torus

    Science.gov (United States)

    Hao, Kun; Cao, Junpeng; Li, Guang-Liang; Yang, Wen-Li; Shi, Kangjie; Wang, Yupeng

    2016-07-01

    The trigonometric su(n) spin chain with anti-periodic boundary condition (su(n) spin torus) is demonstrated to be Yang-Baxter integrable. Based on some intrinsic properties of the R-matrix, certain operator product identities of the transfer matrix are derived. These identities and the asymptotic behavior of the transfer matrix together allow us to obtain the exact eigenvalues in terms of an inhomogeneous T  -  Q relation via the off-diagonal Bethe Ansatz.

  10. Space Science for Children: All about the Sun [Videotape].

    Science.gov (United States)

    1999

    This 23-minute videotape aims to give children, grades K-4, a broad understanding of the center of our solar system, the sun. It explains how the sun provides us with life-giving light and heat, how it's responsible for our seasons and weather, and why it's the primary source of energy on Earth. A hands-on activity in which children create their…

  11. What does the Sun teach us about properties of matter?

    Science.gov (United States)

    Basu, S.

    2003-05-01

    Helioseismology has proved to be an extremely powerful tool to study the structure and dynamics of the Sun. This technique also allows the Sun to be used as a laboratory to study the properties of matter. In this talk I shall discuss how we use helioseismology to study properties of matter, and what we have learned so far. In particular, I shall concentrate on neutrinos and stellar equations of state.

  12. Magnetic Bipoles in Emerging Flux Regions on the Sun

    Science.gov (United States)

    Barth, C. S.; Livi, S. H. B.

    1990-11-01

    ABSTRACT. We analyse magnetograms and H-alpha filtergrams of an Emerging Flux Region. Small bipoles have been observed on the magnetograms emerging between opposite polarities. Separation velocities of the opposite poles for 45 bipoles observed on June 9, 1985 have been measured and are in the range 0.5 contribuciones de los bipolos emergentes. Key words: SUN-CHROMOSPHERE - SUN-MAGNETIC FIELDS

  13. 孙美琳的礼物%Sun Meilin's Gift

    Institute of Scientific and Technical Information of China (English)

    Jack

    2004-01-01

    @@ Sun Meilin was thinking about the time when she lived in Guangzhou with her husband. Their marriage was a happy one, until one day when she came home early from work and found her husband in bed, making love to an old friend of hers. Sun had walked into her apartment using her key to get in, and then into her room, expecting nothing out of the ordinary.

  14. The EUV emission from sun-grazing comets

    OpenAIRE

    Bryans, Paul; Pesnell, W Dean

    2012-01-01

    The Atmospheric Imaging Assembly (AIA) on the Solar Dynamics Observatory (SDO) has observed two sun-grazing comets as they passed through the solar atmosphere. Both passages resulted in a measurable enhancement of Extreme Ultraviolet (EUV) radiance in several of the AIA bandpasses. We explain this EUV emission by considering the evolution of the cometary atmosphere as it interacts with the ambient solar atmosphere. Molecules in the comet rapidly sublimate as it approaches the Sun. They are th...

  15. Khufu, Khafre and Menkaure Pyramids and the Sun

    CERN Document Server

    Sparavigna, Amelia Carolina

    2016-01-01

    In this paper we discuss the orientation of the Egyptian pyramids at Giza with respect to sunrises and sunsets, using SunCalc.net software. We can see that Khufu and Khafre pyramids had been positioned in a manner that, from each pyramid, it was always possible to observe the points of the horizon where the sun was rising and setting on each day of the year. A discussion for the Menkaure pyramid is also proposed.

  16. SunShot Vision Study: February 2012 (Book)

    Energy Technology Data Exchange (ETDEWEB)

    2012-02-01

    The objective of the SunShot Vision Study is to provide an in-depth assessment of the potential for solar technologies to meet a significant share of electricity demand in the United States during the next several decades. Specifically, it explores a future in which the price of solar technologies declines by about 75% between 2010 and 2020 - in line with the U.S. Department of Energy (DOE) SunShot Initiative's targets.

  17. CONCEPTUAL STEPS TOWARDS EXPLORING THE FUNDAMENTAL NATURE OF OUR SUN

    Directory of Open Access Journals (Sweden)

    Attila Grandpierre

    2004-06-01

    Full Text Available One of the basic questions of solar research is the nature of the Sun. We show here how the plasma nature of the Sun leads to the self-generation of solar activity. The release of magnetic, rotational, gravitational, nuclear energies and that of the gravity mode oscillations deviate from uniformity and spherical symmetry. Through instabilities they lead to the emergence of sporadic and localized regions like flux tubes, electric filaments, magnetic elements and high temperature regions. A systematic approach exploring the solar collective degrees of freedom, extending to ordering phenomena of the magnetic features related to Higgs fields, is presented. Handling solar activity as transformations of energies from one form to another one presents a picture on the network of the energy levels of the Sun, showing that the Sun is neither a mere "ball of gas" nor a "quiescent steady-state fusion-reactor machine", but a complex self-organizing system. Since complex self-organizing systems are similar to living systems (and, by some opinion, identical with them, we also consider what arguments indicate the living nature of the Sun. Thermodynamic characteristics of the inequilibrium Sun are found important in this respect and numerical estimations of free energy rate densities and specific exergies are derived.

  18. Magnetic cycles of Sun-like stars with different levels of coronal and chromospheric activity — comparison with the Sun

    Science.gov (United States)

    Shimanovskaya, Elena; Bruevich, Vasiliy; Bruevich, Elena

    2016-09-01

    The atmospheric activity of the Sun and Sun-like stars is analyzed involving observations from the HK-project at the Mount Wilson Observatory, the California and Carnegie Planet Search Program at the Keck and Lick Observatories and the Magellan Planet Search Program at the Las Campanas Observatory. We show that for stars of F, G and K spectral classes, the cyclic activity, similar to the 11-yr solar cycle, is different: it becomes more prominent in K-stars. Comparative study of Sun-like stars with different levels of chromospheric and coronal activity confirms that the Sun belongs to stars with a low level of chromospheric activity and stands apart among these stars by its minimum level of coronal radiation and minimum level of variations in photospheric flux.

  19. Magnetic cycles of Sun-like stars with different levels of coronal and chromospheric activity -- comparison with the Sun

    CERN Document Server

    Bruevich, E A; Shimanovskaya, E V

    2016-01-01

    The atmospheric activity of the Sun and Sun-like stars is analyzed involving observations from HK-project at the Mount Wilson Observatory, the California and Carnegie Planet Search Program at the Keck and Lick Observatories and the Magellan Planet Search Program at the Las Campanas Observatory. We show that for stars of F, G and K spectral classes, the cyclic activity, similar to the 11-yr solar cycles, is different: it becomes more prominent in K-stars. Comparative study of Sun-like stars with different levels of the chromospheric and coronal activity confirms that the Sun belongs to stars with the low level of the chromospheric activity and stands apart among these stars by the minimum level of its coronal radiation and the minimum level of its variations of the photospheric flux.

  20. An automated method for the evaluation of the pointing accuracy of Sun-tracking devices

    Science.gov (United States)

    Baumgartner, Dietmar J.; Pötzi, Werner; Freislich, Heinrich; Strutzmann, Heinz; Veronig, Astrid M.; Rieder, Harald E.

    2017-03-01

    The accuracy of solar radiation measurements, for direct (DIR) and diffuse (DIF) radiation, depends significantly on the precision of the operational Sun-tracking device. Thus, rigid targets for instrument performance and operation have been specified for international monitoring networks, e.g., the Baseline Surface Radiation Network (BSRN) operating under the auspices of the World Climate Research Program (WCRP). Sun-tracking devices that fulfill these accuracy requirements are available from various instrument manufacturers; however, none of the commercially available systems comprise an automatic accuracy control system allowing platform operators to independently validate the pointing accuracy of Sun-tracking sensors during operation. Here we present KSO-STREAMS (KSO-SunTRackEr Accuracy Monitoring System), a fully automated, system-independent, and cost-effective system for evaluating the pointing accuracy of Sun-tracking devices. We detail the monitoring system setup, its design and specifications, and the results from its application to the Sun-tracking system operated at the Kanzelhöhe Observatory (KSO) Austrian radiation monitoring network (ARAD) site. The results from an evaluation campaign from March to June 2015 show that the tracking accuracy of the device operated at KSO lies within BSRN specifications (i.e., 0.1° tracking accuracy) for the vast majority of observations (99.8 %). The evaluation of manufacturer-specified active-tracking accuracies (0.02°), during periods with direct solar radiation exceeding 300 W m-2, shows that these are satisfied in 72.9 % of observations. Tracking accuracies are highest during clear-sky conditions and on days where prevailing clear-sky conditions are interrupted by frontal movement; in these cases, we obtain the complete fulfillment of BSRN requirements and 76.4 % of observations within manufacturer-specified active-tracking accuracies. Limitations to tracking surveillance arise during overcast conditions and

  1. New Suns in the Cosmos II: Differential rotation in $Kepler$ Sun-like stars

    CERN Document Server

    Chagas, M L Das; Costa, A D; Lopes, C E Ferreira; Sobrinho, R Silva; Paz-Chinchón, F; Leão, I C; Valio, A; de Freitas, D B; Martins, B L Canto; Lanza, A F; De Medeiros, J R

    2016-01-01

    The present study reports the discovery of Sun-like stars, namely main-sequence stars with $T_{\\rm eff}$, $\\log g$ and rotation periods $P_{rot}$ similar to solar values, presenting evidence of surface differential rotation. An autocorrelation of the time series was used to select stars presenting photometric signal stability from a sample of 881 stars with light curves collected by the $Kepler$ space-borne telescope, in which we have identified 17 stars with stable signals. A simple two-spot model together with a Bayesian information criterion were applied to these stars in the search for indications of differential rotation; in addition, for all 17 stars, it was possible to compute the spot rotation period $P$, the mean values of the individual spot rotation periods and their respective colatitudes, and the relative amplitude of the differential rotation.

  2. New Suns in the Cosmos II: differential rotation in Kepler Sun-like stars

    Science.gov (United States)

    Das Chagas, M. L.; Bravo, J. P.; Costa, A. D.; Ferreira Lopes, C. E.; Silva Sobrinho, R.; Paz-Chinchón, F.; Leão, I. C.; Valio, A.; de Freitas, D. B.; Canto Martins, B. L.; Lanza, A. F.; De Medeiros, J. R.

    2016-12-01

    The present study reports the discovery of Sun-like stars, namely main-sequence stars with Teff, log g and rotation periods Prot similar to solar values, presenting evidence of surface differential rotation (DR). An autocorrelation of the time series was used to select stars presenting photometric signal stability from a sample of 881 stars with light curves collected by the Kepler space-borne telescope, in which we have identified 17 stars with stable signals. A simple two-spot model together with a Bayesian information criterion were applied to these stars in the search for indications of DR; in addition, for all 17 stars, it was possible to compute the spot rotation period P, the mean values of the individual spot rotation periods and their respective colatitudes, and the relative amplitude of the DR.

  3. Pico-satellite Autonomous Navigation with Magnetometer and Sun Sensor Data

    Institute of Scientific and Technical Information of China (English)

    HAN Ke; WANG Hao; TU Binjie; JIN Zhonghe

    2011-01-01

    This article presents a near-Earth satellite orbit estimation method for pico-satellite applications with light-weight and low-power requirements.The method provides orbit information autonomously from magnetometer and sun sensor, with an extended Kalman filter (EKF).Real-time position/velocity parameters are estimated with attitude independently from two quantities: the measured magnitude of the Earth's magnetic field, and the measured dot product of the magnetic field vector and the sun vector.To guarantee the filter's effectiveness, it is recommended that the sun sensor should at least have the same level of accuracy as magnetometer.Furthermore, to reduce filter's computation expense, simplification methods in EKF's Jacobian calculations are introduced and testified, and a polynomial model for fast magnetic field calculation is developed.With these methods,50% of the computation expense in dynamic model propagation and 80% of the computation burden in measurement model calculation can be reduced.Tested with simulation data and compared with original magnetometer-only methods, filter achieves faster convergence and higher accuracy by 75% and 30% respectively, and the suggested simplification methods are proved to be harmless to filter's estimation performance.

  4. Around the Sun in a Graphing Calculator.

    Science.gov (United States)

    Demana, Franklin; Waits, Bert K.

    1989-01-01

    Discusses the use of graphing calculators for polar and parametric equations. Presents eight lines of the program for the graph of a parametric equation and 11 lines of the program for a graph of a polar equation. Illustrates the application of the programs for planetary motion and free-fall motion. (YP)

  5. A Community Python Library for Solar Physics (SunPy)

    Science.gov (United States)

    Christe, Steven; Shih, A. Y.; Ireland, J.; Perez-Suarez, D.; Mumford, S.; Hughitt, V. K.; Hewett, R.; Mayer, F.; SunPy Dev Team

    2013-07-01

    Python, a free, cross platform, general purpose, high-level programming language, has seen widespread adoption among the scientific community resulting in the availability of a large range of software, from numerical computation (NumPy, SciPy) and machine learning to spectral analysis and visualization (Matplotlib). SunPy is a data analysis toolkit specializing in providing the software necessary to analyze solar and heliospheric datasets in Python. It aims to provide a free and open-source alternative to the IDL-based SolarSoft (SSW) solar data analysis environment. We present the latest release of SunPy (0.3). This release includes a major refactor of the main SunPy code to improve ease of use for the user as well as a more consistent interface. SunPy provides downloading capability through integration with the Virtual Solar Observatory (VSO) and the the Heliophysics Event Knowledgebase (HEK). It can open image fits files from major solar missions (SDO/AIA, SOHO/EIT, SOHO/LASCO, STEREO) into WCS-aware maps. SunPy provides advanced time-series tools for data from mission such as GOES, SDO/EVE, and Proba2/LYRA as well as support for radio spectra (e.g. e-Callisto). We present examples of solar data analysis in SunPy, and show how Python-based solar data-analysis can leverage the many existing data analysis tools already available in Python. We discuss the future goals of the project and encourage interested users to become involved in the planning and development of SunPy.

  6. Photometric Variations In The Sun And Solar-Type Stars

    Science.gov (United States)

    Giampapa, Mark

    The rich array of solar magnetic field-related phenomena we see occurs not only on stellar counterparts of our Sun but in stars that represent significant departures in their fundamental parameters from those of the Sun. Though these phenomena appear energetically negligible when compared to the total luminosity of stars, they nevertheless govern the angular momentum evolution and modulate the radiative and particle output of the Sun and late-type stars. The term "The Solar-Stellar Connection" has been coined to describe the solar-stellar synergisms in the investigation of the generation, emergence and coupling of magnetic fields with the outer solar-stellar atmosphere to produce what we broadly refer to as magnetic activity. With the discovery of literally thousands of planets beyond our solar system, the Solar-Stellar-Planet Connection is quickly emerging as a new area of investigation of the impacts of magnetic activity on exoplanet atmospheres. In parallel with this rapid evolution in our perspectives is the advent of transformative facilities for the study of the Sun and the dynamic Universe. The primary focus of this invited talk will be on photometric variations in solar-type stars and the Sun. These brightness variations are associated with thermal homogeneities typically defined by magnetic structures that are also spatially coincident with key radiative proxies. Photometric variability in solar-type stars and the Sun includes transient brightening, rotational modulation by cool spots and cycle-related variability, each with a characteristic signature in time and wavelength. The emphasis of this presentation will be on the relationship between broadband photometric variations and magnetic field-related activity in solar-type stars and the Sun. Facets of this topic will be discussed both retrospectively and prospectively as we enter a revolutionary, new era for astronomy.

  7. Orbit Determination Error Analysis Results for the Triana Sun-Earth L2 Libration Point Mission

    Science.gov (United States)

    Marr, G.

    2003-01-01

    Using the NASA Goddard Space Flight Center's Orbit Determination Error Analysis System (ODEAS), orbit determination error analysis results are presented for all phases of the Triana Sun-Earth L1 libration point mission and for the science data collection phase of a future Sun-Earth L2 libration point mission. The Triana spacecraft was nominally to be released by the Space Shuttle in a low Earth orbit, and this analysis focuses on that scenario. From the release orbit a transfer trajectory insertion (TTI) maneuver performed using a solid stage would increase the velocity be approximately 3.1 km/sec sending Triana on a direct trajectory to its mission orbit. The Triana mission orbit is a Sun-Earth L1 Lissajous orbit with a Sun-Earth-vehicle (SEV) angle between 4.0 and 15.0 degrees, which would be achieved after a Lissajous orbit insertion (LOI) maneuver at approximately launch plus 6 months. Because Triana was to be launched by the Space Shuttle, TTI could potentially occur over a 16 orbit range from low Earth orbit. This analysis was performed assuming TTI was performed from a low Earth orbit with an inclination of 28.5 degrees and assuming support from a combination of three Deep Space Network (DSN) stations, Goldstone, Canberra, and Madrid and four commercial Universal Space Network (USN) stations, Alaska, Hawaii, Perth, and Santiago. These ground stations would provide coherent two-way range and range rate tracking data usable for orbit determination. Larger range and range rate errors were assumed for the USN stations. Nominally, DSN support would end at TTI+144 hours assuming there were no USN problems. Post-TTI coverage for a range of TTI longitudes for a given nominal trajectory case were analyzed. The orbit determination error analysis after the first correction maneuver would be generally applicable to any libration point mission utilizing a direct trajectory.

  8. SOHO reveals violent action on the quiet Sun

    Science.gov (United States)

    1996-05-01

    SOHO's scientists are impressed by the vigorous action that they see going on every day, because the Sun is in the very quietest phase of its eleven-year cycle of activity. To ground-based observatories it appears extremely calm just now. The early indications of SOHO's performance amply justify the creation of a sungazing spacecraft capable of observing ultraviolet emissions that are blotted out by the Earth's atmosphere. Apart from the imager, two ultraviolet spectrometers and an ultraviolet coronagraph (an imager for the outer atmosphere) are busy analysing the violent processes at a wide range of wavelengths. Between them, these instruments should cure long-lasting ignorance concerning the Sun, especially about why the atmosphere is so hot and what drives the solar wind that blows non-stop into the Solar System. Scientists from other experimental teams use SOHO to explore the Sun from its deep interior to the far reaches of the solar wind. They have watched the supposedly quiet Sun belching huge masses of gas into space. They have mapped a hole burnt by the solar wind in a breeze of gas coming from the stars. And they have detected currents of gas flowing just below the visible surface. SOHO is a project of international cooperation between the European Space Agency and NASA. The spacecraft was built in Europe and instrumented by scientists on both sides of the Atlantic. NASA launched SOHO on 2 December 1995, and also provides the ground stations and an operations centre near Washington. The first results are the more remarkable because SOHO arrived at its vantage point 1,500,000 kilometres out in space only in February, and formally completed its commissioning on 16 April. It has a long life ahead of it. All scientific instruments are working well. The luminosity oscillation imager belonging to the VIRGO experiment had trouble with its lens cover. When opened, the cover rebounded on its hinges and closed again. Commands were devised that gave a shorter impulse

  9. Ancient cults of the sun (German Title: Antike Sonnenkulte)

    Science.gov (United States)

    Hansen, Rahlf

    In ancient astronomy, the heliocentric system of Aristarchus of Samos did not meet universal approval. Contrary to that, the cult of the sun gained immense importance in the Roman Empire. Relics of this significance we still find e.g. in the meaning of the Sunday in the week and in the date of Christmas. The rise of the sun cults is characterised by the merging of different gods from various cultures. Already in classical Greece the god of the sun, Helios, almagated with the god of light, Apollo. The resulting entity was regarded as the harmonic guide of the visible universe, symbolized by Apoll. As well as he plays the lyre, he conducts the cosmos harmonically as the sun. Plato recommends to politicians to study musical harmonics and astronomy in order to get a feeling of the right way to rule the state. In consequence to the conquests of Alexander the Great, the Babylonian star religion was mingled with Greek cosmology and the concept of transmigration of souls. The astrology resulting therefrom spread out over the whole Hellenistic world and was very common in the Roman Empire. The calendar with its religious division of time as the days of the week, following the principle of the gods of the planets governing the hour, was well known. The god of the sun was graded up by the adoption of the calendar of the sun from Egypt by Caesar. Augustus chose Apoll as his guardian god and built with “his” sundial a symbol of the god of the sun, which was visible from a long distance. Augustus used more astral symbols as propaganda of leadership. During the competition with the Parthians, another large empire, for world domination the focus fell on an Iranian god: the Iranian god of light and contract - Mithras. Shortly before 100 A.D., a new cult of mysteries arose in the Roman Empire, called cult of Mithras, and spread quickly. It combined the attributes of a classical sun-god with a religion of salvation, guaranteed by baptism, communion and seven degrees to be passed

  10. Sun-Earth Day - Teaching Heliophysics Through Education Technology

    Science.gov (United States)

    Thieman, J.; Cline, T.; Lewis, E.

    2010-01-01

    Sun-Earth Day (SED) is an Education and Outreach program supported by the U.S, National Aeronautics and Space Administration (NASA). The intent of the program is to teach students and the general public about Heliophysics (the science of the study of the Sun, how it varies, and how solar dynamics affect the rest of the solar system, especially the Earth). The program was begun ten years ago. Each year since that time a particular day has been designated as "Sun-Earth Day ,,. Usually the day of the spring equinox (March 20 or 21) is Sun-Earth Day, but other days have been used as well. Each year a theme is chosen relating to Heliophysics and events reflecting that theme are planned not only for Sun-Earth Day, but for the entire year. From the very beginning educational technology was emphasized in the events in order to effectively reach wide audiences with the SED message. The main approach has been to have a "webcast" related to each year's theme, often from a location that supports the theme as well. For example, a webcast took place from the Mayan pyramids at Chichen Itza, Mexico to highlight the theme of "Ancient Observatories, Timeless Knowledge". Webcasts were not the only technology employed, however. Many of the themes centered on the dynamic nature of the Sun and the effects that solar storms can have on interplanetary space and in our day-to-day life on Earth. Activities for tracking when solar storms happen and how they affect the Earth were developed and brought together in an educational package called Space Weather Action Centers. This project is explained in more detail in another presentation in this session being given by Norma Teresinha Oliveira Reis. Recent Sun-Earth Days have utilized "social networking" technologies to reach widespread groups on the internet. Podcasts, Vodcasts, Facebook, Twitter, and Second Life are the types of network technologies being employed now. The NASA Distance learning Network is another method for bringing Sun

  11. Sun exposure patterns of urban, suburban, and rural children

    DEFF Research Database (Denmark)

    Bodekær, Mette; Petersen, Bibi; Philipsen, Peter Alshede

    2015-01-01

    BACKGROUND: Sun exposure is the main etiology of skin cancer. Differences in skin cancer incidence have been observed between rural and urban populations. OBJECTIVES: As sun exposure begins in childhood, we examined summer UVR exposure doses and sun behavior in children resident in urban, suburban......, and rural areas. METHODS: Personal, electronic UVR dosimeters and sun behavior diaries were used during a summer (3.5 months) by 150 children (4-19 years of age) resident in urban, suburban, and rural areas. RESULTS: On school/kindergarten days rural children spent more time outdoors and received higher UVR...... doses than urban and suburban children (rural: median 2.3 h per day, median 0.9 SED per day, urban: median 1.3 h per day, median 0.3 SED per day, suburban: median 1.5 h per day, median 0.4 SED per day) (p ≤ 0.007). Urban and suburban children exhibited a more intermittent sun exposure pattern than rural...

  12. A High Temperature Liquid Plasma Model of the Sun

    Directory of Open Access Journals (Sweden)

    Robitaille P.-M.

    2007-01-01

    Full Text Available In this work, a liquid model of the Sun is presented wherein the entire solar mass is viewed as a high density/high energy plasma. This model challenges our current understanding of the densities associated with the internal layers of the Sun, advocating a relatively constant density, almost independent of radial position. The incompressible nature of liquids is advanced to prevent solar collapse from gravitational forces. The liquid plasma model of the Sun is a non-equilibrium approach, where nuclear reactions occur throughout the solar mass. The primary means of addressing internal heat transfer are convection and conduction. As a result of the convective processes on the solar surface, the liquid model brings into question the established temperature of the solar photosphere by highlighting a violation of Kirchhoff’s law of thermal emission. Along these lines, the model also emphasizes that radiative emission is a surface phenomenon. Evidence that the Sun is a high density/high energy plasma is based on our knowledge of Planckian thermal emission and condensed matter, including the existence of pressure ionization and liquid metallic hydrogen at high temperatures and pressures. Prior to introducing the liquid plasma model, the historic and scientific justifications for the gaseous model of the Sun are reviewed and the gaseous equations of state are also discussed.

  13. Was Lepenski Vir an ancient Sun or Pleiades observatory?

    CERN Document Server

    Pankovic, Vladan; Krmar, Miodrag

    2015-01-01

    In this work we consider some old hypotheses according to which remarkable mesolithic village Lepenski Vir (9500 -- 5500 BC) at the right (nearly west) Danube riverside in the Iron gate in Serbia was an ancient (one of the oldest) Sun observatory. We use method recently suggested by A. C. Sparavigna, concretely we use "freely available software" or local Sun radiation direction simulation computer programs. In this way we obtain and discuss pictures of the sunrise in the Lepenski Vir during winter and summer solstice and spring and autumn equinox in relation to position of the mountains, especially Treskavac (Trescovat) and Kukuvija at left (nearly east) Danube riverside (in Romania). While mountain Kukuvija represents really the marker for the Sun in date of the winter solstice, mountain Treskavac, in despite to usual opinions, does not represent a real marker for the Sun in date of the summer solstice. Sun rises behind Treskavac, roughly speaking, between 22.April and 1. May. It corresponds to year period w...

  14. Low-frequency heliographic observations of the quiet Sun corona

    Science.gov (United States)

    Stanislavsky, A. A.; Koval, A. A.; Konovalenko, A. A.

    2013-12-01

    We present new results of heliographic observations of quiet-Sun radio emission fulfilled by the UTR-2 radio telescope. The solar corona investigations have been made close to the last solar minimum (Cycle 23) in the late August and early September of 2010 by means of the two-dimensional heliograph within 16.5-33 MHz. Moreover, the UTR-2 radio telescope was used also as an 1-D heliograph for one-dimensional scanning of the Sun at the beginning of September 2010 as well as in short-time observational campaigns in April and August of 2012. The average values of integral flux density of the undisturbed Sun continuum emission at different frequencies have been found. Using the data, we have determined the spectral index of quiet-Sun radio emission in the range 16.5-200 MHz. It is equal to -2.1±0.1. The brightness distribution maps of outer solar corona at frequencies 20.0 MHz and 26.0 MHz have been obtained. The angular sizes of radio Sun were estimated. It is found that the solar corona at these frequencies is stretched-out along equatorial direction. The coefficient of corona ellipticity varies slightly during above period. Its mean magnitudes are equal to ≈ 0.75 and ≈ 0.73 at 20.0 MHz and 26.0 MHz, respectively. The presented results for continuum emission of solar corona conform with being ones at higher frequencies.

  15. ON SUN-TO-EARTH PROPAGATION OF CORONAL MASS EJECTIONS: II. SLOW EVENTS AND COMPARISON WITH OTHERS

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Ying D.; Hu, Huidong; Wang, Chi; Yang, Zhongwei; Wang, Rui [State Key Laboratory of Space Weather, National Space Science Center, Chinese Academy of Sciences, Beijing 100190 (China); Luhmann, Janet G. [Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States); Richardson, John D., E-mail: liuxying@spaceweather.ac.cn [Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States)

    2016-02-15

    As a follow-up study on Sun-to-Earth propagation of fast coronal mass ejections (CMEs), we examine the Sun-to-Earth characteristics of slow CMEs combining heliospheric imaging and in situ observations. Three events of particular interest, the 2010 June 16, 2011 March 25, and 2012 September 25 CMEs, are selected for this study. We compare slow CMEs with fast and intermediate-speed events, and obtain key results complementing the attempt of Liu et al. to create a general picture of CME Sun-to-Earth propagation: (1) the Sun-to-Earth propagation of a typical slow CME can be approximately described by two phases, a gradual acceleration out to about 20–30 solar radii, followed by a nearly invariant speed around the average solar wind level; (2) comparison between different types of CMEs indicates that faster CMEs tend to accelerate and decelerate more rapidly and have shorter cessation distances for the acceleration and deceleration; (3) both intermediate-speed and slow CMEs would have speeds comparable to the average solar wind level before reaching 1 au; (4) slow CMEs have a high potential to interact with other solar wind structures in the Sun–Earth space due to their slow motion, providing critical ingredients to enhance space weather; and (5) the slow CMEs studied here lack strong magnetic fields at the Earth but tend to preserve a flux-rope structure with an axis generally perpendicular to the radial direction from the Sun. We also suggest a “best” strategy for the application of a triangulation concept in determining CME Sun-to-Earth kinematics, which helps to clarify confusions about CME geometry assumptions in the triangulation and to improve CME analysis and observations.

  16. An Introduction to Waves and Oscillations in the Sun

    CERN Document Server

    Narayanan, A Satya

    2013-01-01

    Astrophysicists and others studying the Sun will find this expansive coverage of what we know about waves and oscillations in our nearest star an informative introduction to a hot contemporary topic. After a section summarizing the Sun's physical characteristics, the volume moves on to explore the basics of electrodynamics, which in turn facilitate a discussion of magnetohydrodynamics (MHD). The material also details the often complex nature of waves and oscillations in uniform and non-uniform media, before categorizing the observational signatures of oscillations and exploring the instabilities in fluid, dealing with a range of known forms. Lastly, a section on helioseismology explores our growing familiarity with the internal structure of the Sun. This book is a unified portal to a thorough grounding in solar waves that includes a wealth of explanatory vignettes demystifying concepts such as flux tubes, current-free and force-free magnetic fields, the prominences, and the relationship between the vorticity ...

  17. Skylab Apollo Telescope Mount Spar and Sun End

    Science.gov (United States)

    1971-01-01

    The Apollo Telescope Mount (ATM) was designed and developed by the Marshall Space Flight Center and served as the primary scientific instrument unit aboard Skylab (1973-1979). The ATM contained eight complex astronomical instruments designed to observe the Sun over a wide spectrum from visible light to x-rays. This image depicts the sun end and spar of the ATM flight unit showing individual telescopes. All solar telescopes, the fine Sun sensors, and some auxiliary systems are mounted on the spar, a cruciform lightweight perforated metal mounting panel that divides the canister lengthwise into four equal compartments. The spar assembly was nested inside a cylindrical canister that fit into a complex frame named the rack, and was protected by the solar shield.

  18. Results of I Love My Sun Project 2014-2016

    Science.gov (United States)

    Mosna, Zbysek; Macusova, Eva; Kouba, Daniel; Blanch, Estefania; Humlova, Danka

    2016-08-01

    I Love My Sun is educational project for 4-11 years old children (primary schools). It started as European COST 724 project developed by the team of prof. Dr. Y. Tulunay. During the event, children first draw their idea of the Sun. After that, about 20 min long presentation and discussion is performed by a young scientist in the field of Space and Plasma Physics. Finally, the children use new knowledge, draw their new idea of the Sun and the pictures "before" and "after" are compared. Czech version of the project has been performed since September 2014 in 16 classes of Czech primary schools. Spanish version of the project has been performed at the Ebro Observatory with 60 pre-school children. Up to now we collected more than 300 pairs of pictures.

  19. Sun protection in newborns. A comparison of educational methods.

    Science.gov (United States)

    Bolognia, J L; Berwick, M; Fine, J A; Simpson, P; Jasmin, M

    1991-10-01

    We investigated the effect of education on the sun exposure of newborns. Mothers of healthy newborns (n = 275) were enrolled in the spring of 1989 and interviewed by telephone in the fall of 1989. The mothers were divided into a control group, a low-level intervention group, and a high-level intervention group. Both the low-level and high-level interventions succeeded in reducing the amount of time the newborns were allowed to spend in direct sunlight. Both types of intervention also resulted in reduced sun exposure time for the mothers. Although the number of mothers who used sunscreen was approximately the same in all three groups, when sunscreen use was controlled for, the intervention groups spent significantly less unprotected time in the sun than the control group. The mothers and newborns in both intervention groups simply spent less time outdoors.

  20. The Sun. A typical star in the solar neighborhood?

    CERN Document Server

    Melendez, Jorge

    2013-01-01

    The Sun is used as the fundamental standard in chemical abundance studies, thus it is important to know whether the solar abundance pattern is representative of the solar neighborhood. Albeit at low precision (0.05 - 0.10 dex) the Sun seems to be a typical solar-metallicity disk star, at high precision (0.01 dex) its abundance pattern seems abnormal when compared to solar twins. The Sun shows a deficiency of refractory elements that could be due to the formation of terrestrial planets. The formation of giant planets may also introduce a signature in the chemical composition of stars. We discuss both planet signatures and also the enhancement of neutron-capture elements in the solar twin 18 Sco.

  1. Dimming of the Mid-20th Century Sun

    CERN Document Server

    Foukal, Peter

    2015-01-01

    Advances in understanding of the white light faculae measured at the Royal Greenwich Observatory from 1874 to 1976 suggest that they offer a more direct measure of solar brightening by small diameter photospheric magnetic flux tubes than do chromospheric proxies. Proxies such as the area of Ca K plages, the Mg index or the microwave flux include many dark photospheric structures as well as pores and sunspots. Our reconstruction of variation in total solar irradiance,TSI,based on the faculae indicates that the sun dimmed by almost 0.1 percent in the mid- twentieth century rather than brightening as represented in previous reconstructions. This dimmimg at the sun's highest activity level since the seventeenth century is consistent with the photometric behavior observed in somewhat younger sun like stars. The prolonged TSI decrease may have contributed more to the cooling of climate between about 1940 and 1970 than present models indicate.

  2. What Is the Source of Quiet Sun Transition Region Emission?

    CERN Document Server

    Schmit, Donald

    2016-01-01

    Dating back to the first observations of the on-disk corona, there has been a qualitative link between the photosphere's magnetic network and enhanced transition-temperature plasma emission. These observations led to the development of a general model that describes emission structures through the partitioning of the atmospheric volume with different magnetic loop geometries that exhibit different energetic equilibria. Does the internetwork produce transition-temperature emission? What fraction of network flux connects to the corona? How does quiet sun emission compare with low-activity Sun-like stars? In this work, we revisit the canonical model of the quiet sun, with high-resolution observations from IRIS and HMI in hand, to address those questions. We use over 900 deep exposures of Si IV 1393A from IRIS along with nearly simultaneous HMI magnetograms to quantify the correlation between transition-temperature emission structures and magnetic field concentrations through a number of novel statistics. Our obs...

  3. The Real Reasons for Seasons--Sun-Earth Connections: Unraveling Misconceptions about the Earth and Sun. Grades 6-8. Teacher's Guide. LHS GEMS.

    Science.gov (United States)

    Gould, Alan; Willard, Carolyn; Pompea, Stephen

    This guide is aimed at helping students arrive at a clear understanding of seasons as they investigate the connections between the sun and the earth. Activities include: (1) "Name the Season"; (2) "Sun-Earth Survey"; (3) "Trip to the Sun"; (4) "What Shape is Earth's Orbit?"; (5) "Temperatures around the…

  4. The Sun as you never saw it before

    Science.gov (United States)

    1997-02-01

    The remarkable images come from SOHO's visible-light coronagraph LASCO. It masks the intense rays from the Sun's surface in order to reveal the much fainter glow of the solar atmosphere, or corona. Operated with its widest field of view, in its C3 instrument, LASCO's unprecedented sensitivity enables it to see the thin ionized gas of the solar wind out to the edges of the picture, 22 million kilometres from the Sun's surface. Many stars are brighter than the gas, and they create the background scene. The results alter human perceptions of the Sun. Nearly 30 years ago, Apollo photographs of the Earth persuaded everyone of what until then they knew only in theory, that we live on a small planet. Similarly the new imagery shows our motion in orbit around the Sun, and depicts it as one star among - yet close enough to fill the sky emanations that engulf us. For many centuries even astrologers knew that the Sun was in Sagittarius in December and drifting towards the next zodiacal constellation, Capricornus. This was a matter of calculation only, because the Sun's own brightness prevented a direct view of the starfield. The SOHO-LASCO movie makes this elementary point of astronomy a matter of direct observation for the first time. The images are achievable only from a vantage point in space, because the blue glow of the Earth's atmosphere hides the stars during the day. A spacial allocation of observing time, and of data tranmission from the SOHO spacecraft, enabled the LASCO team to obtain large numbers of images over the period 22-28 December 1996. Since then, a sustained effort in image processing, frame by frame, has achieved a result of high technical and aesthetic quality. Only now is the leader of the LASCO team, Guenter Brueckner of the US Naval Research Laboratory, satisfied with the product and ready to authorize its release. "I spend my life examining the Sun," Brueckner says, "but this movie is a special thrill. For a moment I forget the years of effort that

  5. Simple transfer calibration method for a Cimel Sun-Moon photometer: calculating lunar calibration coefficients from Sun calibration constants.

    Science.gov (United States)

    Li, Zhengqiang; Li, Kaitao; Li, Donghui; Yang, Jiuchun; Xu, Hua; Goloub, Philippe; Victori, Stephane

    2016-09-20

    The Cimel new technologies allow both daytime and nighttime aerosol optical depth (AOD) measurements. Although the daytime AOD calibration protocols are well established, accurate and simple nighttime calibration is still a challenging task. Standard lunar-Langley and intercomparison calibration methods both require specific conditions in terms of atmospheric stability and site condition. Additionally, the lunar irradiance model also has some known limits on its uncertainty. This paper presents a simple calibration method that transfers the direct-Sun calibration constant, V0,Sun, to the lunar irradiance calibration coefficient, CMoon. Our approach is a pure calculation method, independent of site limits, e.g., Moon phase. The method is also not affected by the lunar irradiance model limitations, which is the largest error source of traditional calibration methods. Besides, this new transfer calibration approach is easy to use in the field since CMoon can be obtained directly once V0,Sun is known. Error analysis suggests that the average uncertainty of CMoon over the 440-1640 nm bands obtained with the transfer method is 2.4%-2.8%, depending on the V0,Sun approach (Langley or intercomparison), which is comparable with that of lunar-Langley approach, theoretically. In this paper, the Sun-Moon transfer and the Langley methods are compared based on site measurements in Beijing, and the day-night measurement continuity and performance are analyzed.

  6. Occupational sun protection: workplace culture, equipment provision and outdoor workers' characteristics.

    Science.gov (United States)

    Reeder, Anthony I; Gray, Andrew; McCool, Judith P

    2013-01-01

    The aim of this study was to describe outdoor workers' sun-protective practices, workplace sun-safety culture and sun-protective equipment provision; investigate the association of demographic, personal and occupational factors with sun-protective practices; and identify potential strategies for improving workers' sun protection. The present study used a clustered survey design with randomly identified employers in nine occupations. Employees provided questionnaire measures of demographics, personal characteristics (skin type, skin cancer risk perceptions, tanning attitudes, sun-exposure knowledge), personal occupational sun protection practices (exposure reduction, use of sun-protective clothing, sunscreen and shade), workplace sun-protective equipment provision and perceived workplace sun-safety culture. Summative scores were calculated for attitudes, knowledge, workplace provision and culture. A multivariable model was built with worker and workplace variables as plausible predictors of personal sun protection. In this study, 1,061 workers (69% participation) from 112 workplaces provided sufficient information for analysis. Sex, age, prioritized ethnicity, education and risk perception differed significantly between occupational groups (pworkplace sun-protection equipment provision and supportive culture. After adjustment, each one-point increase in Workplace Sun-safety Culture 2013Score (range 12 points) was associated with a 0.16 higher Personal Sun-Protection Score (pWorkplace Provision Score (range 4 points) was associated with a 0.14 higher score (pworkplace culture are promising components for the development of comprehensive programmes to improve outdoor workers' sun-protective practices.

  7. Modeling temperature and stress in rocks exposed to the sun

    Science.gov (United States)

    Hallet, B.; Mackenzie, P.; Shi, J.; Eppes, M. C.

    2012-12-01

    The potential contribution of solar-driven thermal cycling to the progressive breakdown of surface rocks on the Earth and other planets is recognized but under studied. To shed light on this contribution we have launched a collaborative study integrating modern instrumental and numerical approaches to define surface temperatures, stresses, strains, and microfracture activity in exposed boulders, and to shed light on the thermo-mechanical response of boulders to diurnal solar exposure. The instrumental portion of our study is conducted by M. Eppes and coworkers who have monitored the surface and environmental conditions of two ~30 cm dia. granite boulders (one in North Carolina, one in New Mexico) in the field for one and tow years, respectively. Each boulder is instrumented with 8 thermocouples, 8 strain gauges, a surface moisture sensor and 6 acoustic emission (AE) sensors to monitor microfracture activity continuously and to locate it within 2.5 cm. Herein, we focus on the numerical modeling. Using a commercially available finite element program, MSC.Marc®2008r1, we have developed an adaptable, realistic thermo-mechanical model to investigate quantitatively the temporal and spatial distributions of both temperature and stress throughout a boulder. The model accounts for the effects of latitude and season (length of day and the sun's path relative to the object), atmospheric damping (reduction of solar radiation when traveling through the Earth's atmosphere), radiative interaction between the boulder and its surrounding soil, secondary heat exchange of the rock with air, and transient heat conduction in both rock and soil. Using representative thermal and elastic rock properties, as well as realistic representations of the size, shape and orientation of a boulder instrumented in the field in North Carolina, the model is validated by comparison with direct measurements of temperature and strain on the surface of one boulder exposed to the sun. Using the validated

  8. Multispectral Emission of the Sun during the First Whole Sun Month: Magnetohydrodynamic Simulations

    Science.gov (United States)

    Lionello, Roberto; Linker, Jon A.; Mikic, Zoran

    2008-01-01

    We demonstrate that a three-dimensional magnetohydrodynamic (MHD) simulation of the corona can model its global plasma density and temperature structure with sufficient accuracy to reproduce many of the multispectral properties of the corona observed in extreme ultraviolet (EW) and X-ray emission. The key ingredient to this new type of global MHD model is the inclusion of energy transport processes (coronal heating, anisotropic thermal conduction, and radiative losses) in the energy equation. The calculation of these processes has previously been confined to one-dimensional loop models, idealized two-dimensional computations, and three-dimensional active region models. We refer to this as the thermodynamic MHD model, and we apply it to the time period of Carrington rotation 1913 (1996 August 22 to September 18). The form of the coronal heating term strongly affects the plasma density and temperature of the solutions. We perform our calculation for three different empirical heating models: (1) a heating function exponentially decreasing in radius; (2) the model of Schrijver et al.; and (3) a model reproducing the heating properties of the quiet Sun and active regions. We produce synthetic emission images from the density and temperature calculated with these three heating functions and quantitatively compare them with observations from E W Imaging Telescope on the Solar and Heliospheric Observatory and the soft X-ray telescope on Yohkoh. Although none of the heating models provide a perfect match, heating models 2 and 3 provide a reasonable match to the observations.

  9. SUN-RAH: a nucleoelectric BWR university simulator based in reduced order models; SUN-RAH: simulador universitario de nucleoelectrica BWR basado en modelos de orden reducido

    Energy Technology Data Exchange (ETDEWEB)

    Morales S, J.B.; Lopez R, A.; Sanchez B, A.; Sanchez S, R.; Hernandez S, A. [DEPFI, Campus Morelos, en IMTA Jiutepec, Morelos (Mexico)]. e-mail: jms0620@yahoo.com

    2003-07-01

    The development of a simulator that allows to represent the dynamics of a nucleo electric central, with nuclear reactor of the BWR type, using reduced order models is presented. These models present the characteristics defined by the dominant poles of the system (1) and most of those premature operation transitories in a power station can be reproduced with considerable fidelity if the models are identified with data of plant or references of a code of better estimate like RAMONA, TRAC (2) or RELAP. The models of the simulator are developments or own simplifications starting from the physical laws and retaining the main terms. This work describes the objective of the project and the general specifications of the University student of Nucleo electric simulator with Boiling Water Reactor type (SUN-RAH) as well as the finished parts that fundamentally are the nuclear reactor, the one of steam supply (NSSS), the plant balance (BOP), the main controllers of the plant and the implemented graphic interfaces. The pendent goals as well as the future developments and applications of SUN-RAH are described. (Author)

  10. SOHO starts a revolution in the science of the Sun

    Science.gov (United States)

    1996-07-01

    In addition, SOHO has found clues to the forces that accelerate the solar wind of atomic particles blowing unceasingly through the Solar System. By relating the huge outbursts called coronal mass ejections to preceding magnetic changes in the Sun, SOHO scientists hope to predict such events which, in the Earth's vicinity, endanger power supplies and satellites. SOHO sees differences in the strength of the solar wind in various directions, by mapping a cavity in the cloud of interstellar hydrogen surrounding the Sun. As a bonus, SOHO secured remarkable images of Comet Hyakutake, by ultraviolet and visible light. The revolution in solar science will seem more complete when all the pieces and actions of the Sun, detected by twelve different instruments, are brought together in observations and concepts. Fundamental questions will then be open to re-examination, about the origin of the Sun's magnetism, the cause of its variations in the 11-year cycle of sunspot activity, and the consequences for the Solar System at large. SOHO is greater than the sum of its parts. "SOHO takes solar science by storm," says Roger Bonnet, the European Space Agency's Director of Science, "thanks to its combination of instruments. Unprecedented results from individual telescopes and spectrometers are impressive, of course, but what is breathtaking is SOHO's ability to explore the Sun all the way from its nuclear core to the Earth's vicinity and beyond. We can expect a completely new picture of how agitation inside the Sun, transmitted through the solar atmosphere, directly affects us on the Earth." SOHO is a project of international cooperation between the European Space Agency and NASA. The spacecraft was built in Europe and instrumented by scientists on both sides of the Atlantic. NASA launched SOHO and provides the ground stations and an operations centre at the Goddard Space Flight Center near Washington. SOHO has an uninterrupted view of the Sun from a halo orbit around Lagrangian

  11. Purification and Structural Analysis of SUN and KASH Domain Proteins.

    Science.gov (United States)

    Esra Demircioglu, F; Cruz, Victor E; Schwartz, Thomas U

    2016-01-01

    Molecular tethers span the nuclear envelope to mechanically connect the cytoskeleton and nucleoskeleton. These bridge-like tethers, termed linkers of nucleoskeleton and cytoskeleton (LINC) complexes, consist of SUN proteins at the inner nuclear membrane and KASH proteins at the outer nuclear membrane. LINC complexes are central to a variety of cell activities including nuclear positioning and mechanotransduction, and LINC-related abnormalities are associated with a spectrum of tissue-specific diseases, termed laminopathies or envelopathies. Protocols used to study the biochemical and structural characteristics of core elements of SUN-KASH complexes are described here to facilitate further studies in this new field of cell biology.

  12. Cosmic Ray Sun Shadow in Soudan 2 Underground Muon Flux

    CERN Document Server

    Allison, W W M; Ayres, D S; Barrett, W L; Bode, C; Border, P M; Brooks, C B; Cobb, J H; Cotton, R J; Courant, H; Demuth, D M; Fields, T H; Gallagher, H R; García-García, C; Goodman, M C; Gran, R; Joffe-Minor, T M; Kafka, T; Kasahara, S M; Leeson, W; Lichtfield, P J; Longley, N P; Mann, W A; Marshak, M L; Milburn, R H; Miller, W H; Mualem, L M; Napier, A; Oliver, W P; Pearce, G F; Peterson, E A; Petyt, D A; Price, L E; Ruddick, K; Sánchez, M; Schneps, J; Schub, M H; Seidlein, R; Stassinakis, A; Thron, J L; Vasilev, V; Villaume, G; Wakely, S P; West, N; Wall, D

    1999-01-01

    The absorption of cosmic rays by the sun produces a shadow at the earth. The angular offset and broadening of the shadow are determined by the magnitude and structure of the interplanetary magnetic field (IPMF) in the inner solar system. We report the first measurement of the solar cosmic ray shadow by detection of deep underground muon flux in observations made during the entire ten-year interval 1989 to 1998. The sun shadow varies significantly during this time, with a $3.3\\sigma$ shadow observed during the years 1995 to 1998.

  13. Wilson loop expectations in $SU(N)$ lattice gauge theory

    CERN Document Server

    Jafarov, Jafar

    2016-01-01

    This article gives a rigorous formulation and proof of the $1/N$ expansion for Wilson loop expectations in strongly coupled $SU(N)$ lattice gauge theory in any dimension. The coefficients of the expansion are represented as absolutely convergent sums over trajectories in a string theory on the lattice, establishing a kind of gauge-string duality. Moreover, it is shown that in large $N$ limit, calculations in $SU(N)$ lattice gauge theory with coupling strength $2\\beta$ corresponds to those in $SO(N)$ lattice gauge theory with coupling strength $\\beta$ when $|\\beta|$ is sufficiently small.

  14. Presenting the science of the Sun to the general public

    Science.gov (United States)

    Choudhuri, Arnab Rai

    2016-07-01

    Although the science behind the Sun is so fascinating, there has not been sufficient worldwide effort in presenting this science to the general public. My recently published popular science book "Nature's Third Cycle: A Story of Sunspots" (Oxford University Press, 2015) is probably the first popular science book introducing the phenomenology of the solar cycle along with a non-technical account of dynamo theory. I shall discuss my perspective of the challenges involved in presenting the science of the Sun to the public. The Amazon link of my book is: http://www.amazon.co.uk/Natures-Third-Cycle-Story-Sunspots/dp/0199674752/

  15. ON SUN-TO-EARTH PROPAGATION OF CORONAL MASS EJECTIONS

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Ying D. [State Key Laboratory of Space Weather, National Space Science Center, Chinese Academy of Sciences, Beijing (China); Luhmann, Janet G.; Moestl, Christian; Bale, Stuart D.; Lin, Robert P. [Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States); Lugaz, Noe [Space Science Center, University of New Hampshire, Durham, NH 03824 (United States); Davies, Jackie A., E-mail: liuxying@ssl.berkeley.edu [Space Science and Technology Department, Rutherford Appleton Laboratory, Didcot (United Kingdom)

    2013-05-20

    We investigate how coronal mass ejections (CMEs) propagate through, and interact with, the inner heliosphere between the Sun and Earth, a key question in CME research and space weather forecasting. CME Sun-to-Earth kinematics are constrained by combining wide-angle heliospheric imaging observations, interplanetary radio type II bursts, and in situ measurements from multiple vantage points. We select three events for this study, the 2012 January 19, 23, and March 7 CMEs. Different from previous event studies, this work attempts to create a general picture for CME Sun-to-Earth propagation and compare different techniques for determining CME interplanetary kinematics. Key results are obtained concerning CME Sun-to-Earth propagation: (1) the Sun-to-Earth propagation of fast CMEs can be approximately formulated into three phases: an impulsive acceleration, then a rapid deceleration, and finally a nearly constant speed propagation (or gradual deceleration); (2) the CMEs studied here are still accelerating even after the flare maximum, so energy must be continuously fed into the CME even after the time of the maximum heating and radiation has elapsed in the corona; (3) the rapid deceleration, presumably due to interactions with the ambient medium, mainly occurs over a relatively short timescale following the acceleration phase; and (4) CME-CME interactions seem a common phenomenon close to solar maximum. Our comparison between different techniques (and data sets) has important implications for CME observations and their interpretations: (1) for the current cases, triangulation assuming a compact CME geometry is more reliable than triangulation assuming a spherical front attached to the Sun for distances below 50-70 solar radii from the Sun, but beyond about 100 solar radii we would trust the latter more; (2) a proper treatment of CME geometry must be performed in determining CME Sun-to-Earth kinematics, especially when the CME propagation direction is far away from the

  16. Researching on Database Hot Standby Software SUN CLUSTER%SUN CLUSTER数据库双机热备研究

    Institute of Scientific and Technical Information of China (English)

    罗江华; 刘瑞宏

    2012-01-01

    介绍了双机热备的工作原理,Sun cluster的系统需求,构造Sun cluster系统的基本步骤以及在Solaris环境下,采用Sun cluster配置Oracle 10g数据库双机热备系统的情况并对双机切换进行了测试.应用表明,采用了双机热备的数据库系统能有效地避免数据库服务器宕杌而导致的应用系统拒绝服务,从而使应用系统运行更加稳定、可靠.

  17. Sun-Earth Day: Reaching the Education Audience by Informal Means

    Science.gov (United States)

    Thieman, J.; Lewis, E.; Cline, T.

    2010-01-01

    For ten years the Sun-Earth Day program has promoted Heliophysics education to ever larger audiences through events centered on attractive annual themes. What originally started out as a one day event quickly evolved into a series of programs and events that occur throughout the year culminating with a celebration on or near the Spring Equinox. The events are often formal broadcasts or webcasts seeking to convey the science behind the latest solar-terrestrial mission discoveries. This has been quite successful, but it is clear that the younger generation increasingly depends on social networking approaches and informal news transmission for learning what is happening in the world around them. For 2010, the Sun-Earth Day team put emphasis on using informal approaches to bring the theme to the audience. The main event, a webcast from the NASA booth at the National Science Teachers Association (NSTA) annual meeting by the NASA EDGE group, took a lighthearted and offbeat approach to interviewing scientists and educators about Heliophysics news. NASA EDGE programs are unscripted and unpredictable, and that represents a different approach to getting the message across. The webcast was supplemented by a number of social networking avenues. The Sun-Earth Day program explored a wide range of social media applications including Facebook, Twitter, NING, podcasting, iPhone apps, etc. Each of these offers unique and effective methods to promote Heliophysics content and mission related highlights. The facebook site was quite popular and message posting there told the Sun-Earth Day story piece by piece. The same could be said of twittering and the tweetup held at the NSTA site. Has all of this been effective? Results are still being gathered, but anecdotal responses from the world seem very positive. What other methods might be used in the future to bring the science to a personal hands-on, interactive experience? Outcomes: Participants will: (1) Be introduced to the Sun

  18. Could Ultracool Dwarfs Have Sun-Like Activity?

    Science.gov (United States)

    Kohler, Susanna

    2016-11-01

    Solar-like stars exhibit magnetic cycles; our Sun, for instance, displays an 11-year period in its activity, manifesting as cyclic changes in radiation levels, the number of sunspots and flares, and ejection of solar material. Over the span of two activity cycles, the Suns magnetic field flips polarity and then returns to its original state.An artists illustration comparing the Sun to TRAPPIST-1, an ultracool dwarf star known to host several planets. [ESO]But what about the magnetic behavior of objects near the cooler end of the stellar main sequence do they exhibit similar activity cycles?Effects of a Convecting InteriorDwarf stars have made headlines in recent years due to their potential to harbor exoplanets. Because these cooler stars have lower flux levels compared to the Sun, their habitable zones lie much closer to the stars. The magnetic behavior of these stars is therefore important to understand: could ultracool dwarfs exhibit solar-like activity cycles that would affect planets with close orbits?The differences in internal structure between different mass stars. Ultracool dwarfs have fully convective interiors. [www.sun.org]Theres a major difference between ultracool dwarfs (stars of spectral type higher than M7 and brown dwarfs) and Sun-like stars: their internal structures. Sun-like stars have a convective envelope that surrounds a radiative core. The interiors of cool, low-mass objects, on the other hand, are fully convective.Based on theoretical studies of how magnetism is generated in stars, its thought that the fully convective interiors of ultracool dwarfs cant support large-scale magnetic field formation. This should prevent these stars from exhibiting activity cycles like the Sun. But recent radio observations of dwarf stars have led scientist Matthew Route (ITaP Research Computing, Purdue University) to question these models.A Reversing Field?During observations of the brown dwarf star J1047+21 in 20102011, radio flares were detected with

  19. The Eclipse of the Sun: Sun-dials, Clocks and Natural Time in the Late Seventeenth Century.

    Science.gov (United States)

    Turner, Anthony

    2015-01-01

    The Sun, in the early seventeenth century was, as it always had been, the ultimate arbiter of time-measurement In the last quarter of the century however this role was called into question as the new precision of post-Huygenian clocks revealed that natural time and the artificial mean time of the clock were not the same. Initially the question was little understood by the general public. The paper examines some early attempts to explain why "Sun-time" in 1700 was no longer "true-time."

  20. Seismology of the Sun : Inference of Thermal, Dynamic and Magnetic Field Structures of the Interior

    CERN Document Server

    Hiremath, K M

    2012-01-01

    Recent overwhelming evidences show that the sun strongly influences the Earth's climate and environment. Moreover existence of life on this Earth mainly depends upon the sun's energy. Hence, understanding of physics of the sun, especially the thermal, dynamic and magnetic field structures of its interior, is very important. Recently, from the ground and space based observations, it is discovered that sun oscillates near 5 min periodicity in millions of modes. This discovery heralded a new era in solar physics and a separate branch called helioseismology or seismology of the sun has started. Before the advent of helioseismology, sun's thermal structure of the interior was understood from the evolutionary solution of stellar structure equations that mimicked the present age, mass and radius of the sun. Whereas solution of MHD equations yielded internal dynamics and magnetic field structure of the sun's interior. In this presentation, I review the thermal, dynamic and magnetic field structures of the sun's inter...

  1. Analysis of meiosis in SUN1 deficient mice reveals a distinct role of SUN2 in mammalian meiotic LINC complex formation and function.

    Directory of Open Access Journals (Sweden)

    Jana Link

    2014-02-01

    Full Text Available LINC complexes are evolutionarily conserved nuclear envelope bridges, composed of SUN (Sad-1/UNC-84 and KASH (Klarsicht/ANC-1/Syne/homology domain proteins. They are crucial for nuclear positioning and nuclear shape determination, and also mediate nuclear envelope (NE attachment of meiotic telomeres, essential for driving homolog synapsis and recombination. In mice, SUN1 and SUN2 are the only SUN domain proteins expressed during meiosis, sharing their localization with meiosis-specific KASH5. Recent studies have shown that loss of SUN1 severely interferes with meiotic processes. Absence of SUN1 provokes defective telomere attachment and causes infertility. Here, we report that meiotic telomere attachment is not entirely lost in mice deficient for SUN1, but numerous telomeres are still attached to the NE through SUN2/KASH5-LINC complexes. In Sun1(-/- meiocytes attached telomeres retained the capacity to form bouquet-like clusters. Furthermore, we could detect significant numbers of late meiotic recombination events in Sun1(-/- mice. Together, this indicates that even in the absence of SUN1 telomere attachment and their movement within the nuclear envelope per se can be functional.

  2. Measuring sun exposure habits and sun protection behaviour using a comprehensive scoring instrument--an illustration of a possible model based on Likert scale scorings and on estimation of readiness to increase sun protection.

    Science.gov (United States)

    Falk, M; Anderson, C D

    2012-08-01

    Few attempts to present a comprehensive scoring instrument for sun exposure and protection have been made. The present paper aims to describe a possible set of questions suitable for such an instrument, comprising the most important aspects of sun exposure and protection. The material from a previously performed intervention study, using a questionnaire based on Likert scales and on the Transtheoretical Model of Behaviour Change (TTM), was utilised. 213 primary healthcare patients filled in the questionnaire and were randomised into two groups receiving sun protection advice, in Group 1 in letter-form, and in Group 2 orally during a doctor's consultation. In the original study, increased sun protection/readiness to increase sun protection was demonstrated for several items in Group 2, at six months. To compose a comprehensive scoring instrument, five questions concerning sun exposure/protection (intentional tanning, sunscreen use, choice of SPF, number of occasions with sunburn, and time spent in the sun at midday), were selected to give a 20 point behavioural score. Similarly, four TTM-based questions (giving up sunbathing, using clothes for sun protection, using sunscreens, and staying in the shade) gave a 16 point "propensity-to-change"-score. At follow-up, increased sun protection reflected in the behavioural score occurred only in Group 2 (p Likert scale behavioural score with a TTM-based propensity-to-change-score seems promising for the creation of a questionnaire-based, comprehensive scoring instrument for sun exposure and protection. Copyright © 2012 Elsevier Ltd. All rights reserved.

  3. Sun Exposure and Reduced Risk of Multiple Sclerosis

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2008-09-01

    Full Text Available The association between red hair color (RHC melanocortin 1 receptor genotype, past environmental sun exposure, and risk of multiple sclerosis (MS was investigated in a population-based case-control study in Tasmania, Australia, involving 136 cases with MS and 272 controls.

  4. Small-scale eruptive filaments on the quiet sun

    Science.gov (United States)

    Hermans, Linda M.; Martin, Sara F.

    1986-01-01

    A study of a little known class of eruptive events on the quiet sun was conducted. All of 61 small-scale eruptive filamentary structures were identified in a systematic survey of 32 days of H alpha time-lapse films of the quiet sun acquired at Big Bear Solar Observatory. When fully developed, these structures have an average length of 15 arc seconds before eruption. They appear to be the small-scale analog of large-scale eruptive filaments observed against the disk. At the observed rate of 1.9 small-scale eruptive features per field of view per average 7.0 hour day, the rate of occurence of these events on the sun were estimated to be greater than 600 per 24 hour day.. The average duration of the eruptive phase was 26 minutes while the average lifetime from formation through eruption was 70 minutes. A majority of the small-scale filamentary sturctures were spatially related to cancelling magnetic features in line-of-sight photospheric magnetograms. Similar to large-scale filaments, the small-scale filamentary structures sometimes divided opposite polarity cancelling fragments but often had one or both ends terminating at a cancellation site. Their high numbers appear to reflect the much greater flux on the quiet sun. From their characteristics, evolution, and relationship to photospheric magnetic flux, it was concluded that the structures described are small-scale eruptive filaments and are a subset of all filaments.

  5. On the Physical Constitution of the Sun — Part I

    Directory of Open Access Journals (Sweden)

    Faye H.

    2011-07-01

    Full Text Available Patrice Robitaille (TAV College, Montreal, Canada provides a translation of Herv ́ e August Etienne Albans Faye’s classic report Sur la constitution physique du soleil , as it appeared in February 1865 within Les Mondes ,1865, v.7, 293–306. Herv ́ e Faye (Oc- tober 1, 1814 – July 4, 1902 led a distinguished life, both in science and public ser- vice. He was widely regarded as one of the premier astronomers of his day. He had studied under the great Franc ̧ois Arago. In 1843, he became a Chevalier de la Legion d’Honneur and, in 1877, served as the French Minister of Education (Catholic Ency- clopedia, 1913. Faye’s report On the Physical Constitution of the Sun was a crucial milestone in the history of astronomy. It was through this paper, that the Sun became viewed as devoid of a distinct surface. The work was also interesting as it presented Faye’s early conception of the gaseous Sun. In addition, through its submission, Faye had sought the approbation of Father Secchi relative to claims of simultaneous discov- ery (see P.M.Robitaille. A Thermodynamic History of the Solar Constitution — I: The Journey to a Gaseous Sun. Progr. Phys. , 2011, v.3, 3–25. Faye’s work would continue to impact solar physics until the 1920s.

  6. Daidzein: A review of pharmacological effects | Sun | African Journal ...

    African Journals Online (AJOL)

    Meng-Yao Sun, Ying Ye, Ling Xiao, Khalid Rahman, Wei Xia, Hong Zhang ... is an isoflavone with extensive nutritious value and is mainly extracted from soy plants. ... Results: Daidzein is reported to play a significant role in the prevention and ...

  7. Sun Tzu's Art of War and competition and cooperation

    DEFF Research Database (Denmark)

    Odgaard, Liselotte

    rule, state sovereignty and territorial integrity and economic and social development. In line with Sun Tzu’s concepts of strategy, these objectives are attempted achieved by means of a defensive strategy designed to change the status quo in China’s favour. A new status quo involves obtaining...

  8. The Sun's Corona Observed by the Skylab Mission

    Science.gov (United States)

    1970-01-01

    The Sun's corona stretches far beyond the dense, irner corona seen in x-rays and ultraviolet light, and beyond the limits of what we normally see in the dark sky of a total solar eclipse. Its farthest reaches are delineated by tapered streamers that stretch into interplanetary space, extending the domain of our nearest star much farther than its visible disk. We see the outer corona briefly at total eclipses of the Sun, where it appears white and delicate against the starry background of a temporarily darkened, daytime sky. Even then, Earth's intervening atmosphere is bright enough to limit our view of the outer corona. At Skylab's orbital altitude, where almost no air was left and where the sky was starkly black, the outer corona was at last clearly seen. In the thousands of coronal portraits made by Skylab, in which the corona was observed more extensively than in all the centuries of humanity's interest in the Sun, the corona was constantly altering its form, ever adjusting to the shifting magnetic fields from the Sun's surface that so obviously gave it its distinctive shape. Skylab's coronagraph observations coupled with x-ray pictures of the inner corona helped establish the origin of the corona's varied forms and the important connection between coronal holes and high-speed streams in the solar wind.

  9. Teaching "A Raisin in the Sun": Literature and Life.

    Science.gov (United States)

    Lund, Charles

    1989-01-01

    One approach to teaching literature combines a work of drama or fiction with a popular text on human needs and relationships. Virginia Satir's "Peoplemaking," a book on family dynamics, provides a theoretical framework in which to evaluate the decisions of the characters in Lorraine Hansberry's "A Raisin in the Sun." (MSE)

  10. Conceptual Steps towards Exploring the Fundamental Nature of our Sun

    CERN Document Server

    Grandpierre, A

    2004-01-01

    One of the basic questions of solar research is the nature of the Sun. We show here how the plasma nature of the Sun leads to the self-generation of solar activity. The release of magnetic, rotational, gravitational, nuclear energies and that of the gravity mode oscillations deviate from uniformity and spherical symmetry. Through instabilities they lead to the emergence of sporadic and localized regions like flux tubes, electric filaments, magnetic elements and high temperature regions. A systematic approach exploring the solar collective degrees of freedom, extending to ordering phenomena of the magnetic features related to Higgs fields, is presented. Handling solar activity as transformations of energies from one form to another one presents a picture on the network of the energy levels of the Sun, showing that the Sun is neither a mere "ball of gas" nor a "quiescent steady-state fusion-reactor machine", but a complex self-organizing system. Since complex self-organizing systems are similar to living system...

  11. Nilaja Sun's "No Child"...: Revealing Teaching and Learning through Theater

    Science.gov (United States)

    Hetland, Lois

    2009-01-01

    This article presents an analysis of Nilaja Sun's one-woman play, "No Child" . . ., that applies the Studio Habits of Mind framework to reveal essential features of great teaching artistry and great teaching. The play conveys much about twenty-first century schools and the policies that control them; about respect, equity, justice, and the lack of…

  12. DOE SunShot System Integration Program. Accomplishments and Impacts

    Energy Technology Data Exchange (ETDEWEB)

    Boynton, Shannon [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Ellis, Abraham [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2016-02-01

    During FY15, Sandia National Laboratories executed research and development (R&D) work on a portfolio of 16 SunShot Program Systems Integration (SI) agreements, with a total FY15 budget of $13.2 million. This document summarizes the impact of the Sandia contributions based on Sandia’s direct contributions by DOE.

  13. SunShot Catalyst Prize Competition Fact Sheet

    Energy Technology Data Exchange (ETDEWEB)

    Solar Energy Technologies Office

    2015-04-01

    This fact sheet is an overview of the Catalyst Energy Innovation Prize, an open innovation program launched in 2014 by the U.S. Department of Energy SunShot Initiative. This program aims to catalyze the rapid creation and development of products and solutions that address near-term challenges in the U.S. solar energy marketplace.

  14. Micro digital sun sensor: system in a package

    NARCIS (Netherlands)

    Boom, C.W. de; Leijtens, J.A.P.; Duivenbode, L.M.H. van; Heiden, N. van der

    2004-01-01

    A novel micro Digital Sun Sensor (μDSS) is under development in the frame of a micro systems technology (MST) development program (Microned) from the Dutch Ministry of Economic Affairs. Use of available micro system technologies in combination with the implementation of a dedicated solarcell for pow

  15. Solar Energy Education. Reader, Part II. Sun story. [Includes glossary

    Energy Technology Data Exchange (ETDEWEB)

    1981-05-01

    Magazine articles which focus on the subject of solar energy are presented. The booklet prepared is the second of a four part series of the Solar Energy Reader. Excerpts from the magazines include the history of solar energy, mythology and tales, and selected poetry on the sun. A glossary of energy related terms is included. (BCS)

  16. Mechanical Sun-Tracking Technique Implemented for Maximum ...

    African Journals Online (AJOL)

    The solar panel is allowed to move from east to west and back forth with a maximum allowable angle of 180o. Its movement is in only one axis. The prototype built carries the panel from eastward to westward tracking the sun movement from ...

  17. The interstellar cloud surrounding the Sun -- a new perspective

    CERN Document Server

    Gry, Cecile

    2014-01-01

    Aims: We offer a new, simpler picture of the local interstellar medium around the Sun (LISM) made of a single continuous cloud enveloping the Sun. This new outlook enables the description of a diffuse cloud from within and brings to light some unexpected properties. Methods: We re-examine the kinematics and abundances of the local interstellar medium, as revealed by the published results for the ultraviolet absorption lines of MgII, FeII and HI. Results: In contrast to previous representations, our new picture of the LISM consists of a single, monolithic cloud that surrounds the Sun in all directions and accounts for most of the matter present in the first 50 parsecs around the Sun. The cloud fills the space around us out to about 9 pc in most directions, although its boundary is very irregular with possibly a few extensions up to 20 pc. The cloud does not behave like a rigid body: gas within the cloud is being differentially decelerated in the direction of motion, and the cloud is expanding in directions per...

  18. Teaching "A Raisin in the Sun": Literature and Life.

    Science.gov (United States)

    Lund, Charles

    1989-01-01

    One approach to teaching literature combines a work of drama or fiction with a popular text on human needs and relationships. Virginia Satir's "Peoplemaking," a book on family dynamics, provides a theoretical framework in which to evaluate the decisions of the characters in Lorraine Hansberry's "A Raisin in the Sun." (MSE)

  19. Rejuvenating the sun and avoiding other global catastrophes

    CERN Document Server

    Beech, Martin

    2008-01-01

    Canadian academic Martin Beech has written a text that crosses the line between science fiction and science fact. Put simply, his book details a method that just might be able to stop the Sun from losing its power and, ultimately, save humanity and the Earth itself.

  20. The New Woman in "The Sun Also Rises"

    Science.gov (United States)

    Yu, Xiaoping

    2010-01-01

    Hemingway is a famous American writer and a spokesman of the Lost Generation. His life attitude of the characters in the novels influenced the whole world. His first masterpiece "The Sun Also Rises" contributes a lot to the rise of feminism and make the world began to be familiar with a term: The New Woman through the portrayal of Brett.…

  1. Tree Leaf Shadows to the Sun's Density: A Surprising Route

    Science.gov (United States)

    Mallmann, A. James

    2013-01-01

    Rays of sunlight that strike raindrops produce rainbows that provide information about the spectrum of sunlight. Rays of sunlight that strike airborne ice crystals produce halos, sun pillars, and many other patterns of light and color in the sky. Analysis of those patterns makes it possible to determine the types and orientations of the ice…

  2. Distant future of the Sun and Earth revisited

    CERN Document Server

    Schroder, Klaus-Peter

    2008-01-01

    We revisit the distant future of the Sun and the solar system, based on stellar models computed with a thoroughly tested evolution code. For the solar giant stages, mass-loss by the cool (but not dust-driven) wind is considered in detail. Using the new and well-calibrated mass-loss formula of Schroder & Cuntz (2005, 2007), we find that the mass lost by the Sun as an RGB giant (0.332 M_Sun, 7.59 Gy from now) potentially gives planet Earth a significant orbital expansion, inversely proportional to the remaining solar mass. According to these solar evolution models, the closest encounter of planet Earth with the solar cool giant photosphere will occur during the tip-RGB phase. During this critical episode, for each time-step of the evolution model, we consider the loss of orbital angular momentum suffered by planet Earth from tidal interaction with the giant Sun, as well as dynamical drag in the lower chromosphere. We find that planet Earth will not be able to escape engulfment, despite the positive effect o...

  3. Tree Leaf Shadows to the Sun's Density: A Surprising Route

    Science.gov (United States)

    Mallmann, A. James

    2013-01-01

    Rays of sunlight that strike raindrops produce rainbows that provide information about the spectrum of sunlight. Rays of sunlight that strike airborne ice crystals produce halos, sun pillars, and many other patterns of light and color in the sky. Analysis of those patterns makes it possible to determine the types and orientations of the ice…

  4. The Early Years: The Earth-Sun System

    Science.gov (United States)

    Ashbrook, Peggy

    2015-01-01

    We all experience firsthand many of the phenomena caused by Earth's Place in the Universe (Next Generation Science Standard 5-ESS1; NGSS Lead States 2013) and the relative motion of the Earth, Sun, and Moon. Young children can investigate phenomena such as changes in times of sunrise and sunset (number of daylight hours), Moon phases, seasonal…

  5. Are the majority of Sun-like stars single?

    CERN Document Server

    Whitworth, A P

    2015-01-01

    It has recently been suggested that, in the field, $\\sim\\!\\!56\\%$ of Sun-like stars ($0.8\\,{\\rm M}_{_\\odot}\\lesssim M_\\star\\lesssim 1.2\\,{\\rm M}_{_\\odot}$) are single. We argue here that this suggestion may be incorrect, since it appears to be based on the multiplicity frequency of systems with Sun-like primaries, and therefore takes no account of Sun-like stars that are secondary (or higher-order) components in multiple systems. When these components are included in the reckoning, it seems likely that only $\\sim\\!46\\%$ of Sun-like stars are single. This estimate is based on a model in which the system mass function has the form proposed by Chabrier, with a power-law Salpeter extension to high masses; there is a flat distribution of mass ratios; and the probability that a system of mass $M$ is a binary is $\\,0.50 + 0.46\\log_{_{10}}\\!\\left(M/{\\rm M}_{_\\odot}\\right)\\,$ for $\\,0.08\\,{\\rm M}_{_\\odot}\\leq M\\leq 12.5\\,{\\rm M}_{_\\odot}$, $\\,0\\,$ for $\\,M12.5\\,{\\rm M}_{_\\odot}$. The constants in this last relation ar...

  6. Micro digital sun sensor: system in a package

    NARCIS (Netherlands)

    Boom, C.W. de; Leijtens, J.A.P.; Duivenbode, L.M.H. van; Heiden, N. van der

    2004-01-01

    A novel micro Digital Sun Sensor (μDSS) is under development in the frame of a micro systems technology (MST) development program (Microned) from the Dutch Ministry of Economic Affairs. Use of available micro system technologies in combination with the implementation of a dedicated solarcell for pow

  7. Micro digital sun sensor: system in a package

    NARCIS (Netherlands)

    Boom, C.W. de; Leijtens, J.A.P.; Duivenbode, L.M.H. van; Heiden, N. van der

    2004-01-01

    A novel micro Digital Sun Sensor (μDSS) is under development in the frame of a micro systems technology (MST) development program (Microned) from the Dutch Ministry of Economic Affairs. Use of available micro system technologies in combination with the implementation of a dedicated solarcell for

  8. MuSun: muon capture on the deuteron

    Directory of Open Access Journals (Sweden)

    Luo Xiao

    2015-01-01

    Full Text Available The goal of the MuSun experiment at PSI is to measure the rate of muon capture on the deuteron with a precision of 1.5%. This rate will be used to fix the low-energy constant that describes the two-nucleon weak axial current in Chiral perturbation theory. It will therefore calibrate evaluations of solar proton-proton fusion and neutrino-deuteron scattering(SNO experiment. MuSun forms part of the systematic program to achieve a new level of precision in confronting the theories of weak interactions, QCD and few body physics. MuSun inherits some of the well developed techniques and apparatus from a successful measurement of the rate for muon capture on the proton, the MuCap experiment, also performed at PSI. As in MuCap, MuSun uses a TPC as an active target. To optimize the molecular kinetics, its ultra-pure deuterium gas is kept at 31K. The status of the hardware and details of the data analysis for a high statistics run taken in 2013 will be presented.

  9. HIV/AIDS Universal Precaution Practices in Sun Dance Ceremonies.

    Science.gov (United States)

    Giroux, Jennifer; Takehara, Joan; Asetoyer, Charon; Welty, Thomas

    1997-01-01

    The Aberdeen (South Dakota) Area Indian Health Service has sponsored educational projects to reduce risk of HIV transmission via skin piercing and flesh offerings during traditional Sun Dance ceremonies. Projects emphasized universal precautions, provided medical supplies, and respected the sacredness of the ceremony. Evaluation indicates that…

  10. Revival of the "Sun Festival": An educational and outreach project

    Science.gov (United States)

    Montabone, Luca

    2016-10-01

    In ancient times, past civilisations used to celebrate both the winter and summer solstices, which represented key moments in the periodical cycle of seasons and agricultural activities. In 1904, the French astronomer Camille Flammarion, the engineer Gustave Eiffel, the science writer Wilfrid de Fonvielle and the Spanish astronomer Josep Comas i Solà decided to celebrate the summer solstice with a festival of science, art and astronomical observations opened to the public at the Eiffel tower in Paris. For ten consecutive years (1904-1914) on the day of the summer solstice, the "Sun Festival" (Fête du Soleil in French) included scientific and technological lectures and demostrations, celestial observations, music, poetry, danse, cinema, etc. This celebration was interrupted by the First World War, just to resume in Barcelona, Spain, between 1915 and 1937, and in Marseille, France, in the 1930s. It was the founders' dream to extend this celebration to all cities in France and elsewhere.It is only during the International Year of Astronomy in 2009, to our knowledge, that the "Sun Festival" was given another chance in France, thanks to the joint effort of several scientific and cultural centers (Centres de Culture Scientifique, Technique et Industrielle, CCSTI) and the timely support of the European Space Agency (ESA). In this occasion again, the festival was characterized by the combination of science, art and technological innovation around a common denominator: our Sun!We have recently revived the idea of celebrating the summer solstice with a "Sun Festival" dedicated to scientific education and outreach about our star and related topics. This project started last year in Aix-les-Bains, France, with the "Sun and Light Festival" (2015 was the International Year of Light), attended by about 100 people. This year's second edition was in Le Bourget-du-Lac, France. Following the COP21 event, the specific theme was the "Sun and Climate Festival", and we had about 250

  11. Recent Progress in Understanding the Sun's Magnetic Dynamo

    Science.gov (United States)

    Hathaway, David. H.

    2004-01-01

    100 years ago we thought that the Sun and stars shone as a result of slow gravitational contraction over a few tens of millions of years - putting astronomers at odds with geologists who claimed that the Earth was much, much older. That mystery was solved in the 1920s and 30s with the discovery of nuclear energy (proving that the geologists had it right all along). Other scientific mysteries concerning the Sun have come and gone but three major mysteries remain: 1) How does the Sun produce sunspots with an 11-year cycle? 2) What produces the huge explosions that result in solar flares, prominence eruptions, and coronal mass ejections? and 3) Why is the Sun's outer atmosphere, the corona, so darned hot? Recent progress in solar astronomy reveals a single key to understanding all three of these mysteries.The 11-year time scale for the sunspot cycle indicates the presence of a magnetic dynamo within the Sun. For decades this dynamo was though to operate within the Sun's convection zone - the outmost 30% of the Sun where convective currents transport heat and advect magnetic lines of force. The two leading theories for the dynamo had very different models for the dynamics of the convection zone. Actual measurements of the dynamics using the techniques of helioseismology showed that both of these models had to be wrong some 20 years ago. A thin layer of strongly sheared flow at the base of the convection zone (now called the tachocline) was then taken to be the seat of the dynamo. Over the last 10 years it has become apparent that a weak meridional circulation within the convection zone also plays a key role in the dynamo. This meridional circulation has plasma rising up from the tachocline in the equatorial regions, spreading out toward the poles at a top speed of about 10-20 m/s at the surface, sinking back down to the tachocline in the polar regions, and then flowing back toward the equator at a top speed of about 1-2 m/s in the tachocline itself. Recent dynamo

  12. Recent Progress in Understanding the Sun's Magnetic Dynamo

    Science.gov (United States)

    Hathaway, David. H.

    2004-01-01

    100 years ago we thought that the Sun and stars shone as a result of slow gravitational contraction over a few tens of millions of years - putting astronomers at odds with geologists who claimed that the Earth was much, much older. That mystery was solved in the 1920s and 30s with the discovery of nuclear energy (proving that the geologists had it right all along). Other scientific mysteries concerning the Sun have come and gone but three major mysteries remain: 1) How does the Sun produce sunspots with an 11-year cycle? 2) What produces the huge explosions that result in solar flares, prominence eruptions, and coronal mass ejections? and 3) Why is the Sun's outer atmosphere, the corona, so darned hot? Recent progress in solar astronomy reveals a single key to understanding all three of these mysteries.The 11-year time scale for the sunspot cycle indicates the presence of a magnetic dynamo within the Sun. For decades this dynamo was though to operate within the Sun's convection zone - the outmost 30% of the Sun where convective currents transport heat and advect magnetic lines of force. The two leading theories for the dynamo had very different models for the dynamics of the convection zone. Actual measurements of the dynamics using the techniques of helioseismology showed that both of these models had to be wrong some 20 years ago. A thin layer of strongly sheared flow at the base of the convection zone (now called the tachocline) was then taken to be the seat of the dynamo. Over the last 10 years it has become apparent that a weak meridional circulation within the convection zone also plays a key role in the dynamo. This meridional circulation has plasma rising up from the tachocline in the equatorial regions, spreading out toward the poles at a top speed of about 10-20 m/s at the surface, sinking back down to the tachocline in the polar regions, and then flowing back toward the equator at a top speed of about 1-2 m/s in the tachocline itself. Recent dynamo

  13. Earth Oblateness and Relative Sun Motion Considerations in the Determination of an Ideal Orbit for the Nimbus Meteorological Satellite

    Science.gov (United States)

    Bandeen, William R.

    1961-01-01

    It is desired that the Nimbus meteorological satellite always cross the equator around local noon and, half-an-orbit later, cross the equator in the other direction around local midnight. The application of the phenomenon of nodal regression toward this end is discussed, and an analysis of the parameters angles of inclination, periods, and heights of such "ideal" circular orbits is presented. Also, the relative motion of the apparent versus the fictitious mean sun is briefly discussed.

  14. SunPy 0.8 - Python for Solar Physics

    Science.gov (United States)

    Inglis, Andrew; Bobra, Monica; Christe, Steven; Hewett, Russell; Ireland, Jack; Mumford, Stuart; Martinez Oliveros, Juan Carlos; Perez-Suarez, David; Reardon, Kevin P.; Savage, Sabrina; Shih, Albert Y.; Ryan, Daniel; Sipocz, Brigitta; Freij, Nabil

    2017-08-01

    SunPy is a community-developed open-source software library for solar physics. It is written in Python, a free, cross-platform, general-purpose, high-level programming language which is being increasingly adopted throughout the scientific community. Python is one of the top ten most often used programming languages, as such it provides a wide array of software packages, such as numerical computation (NumPy, SciPy), machine learning (scikit-learn), signal processing (scikit-image, statsmodels) to visualization and plotting (matplotlib, mayavi). SunPy aims to provide the software for obtaining and analyzing solar and heliospheric data. This poster introduces a new major release of SunPy (0.8). This release includes two major new functionalities, as well as a number of bug fixes. It is based on 1120 contributions from 34 unique contributors. Fido is the new primary interface to download data. It provides a consistent and powerful search interface to all major data sources provides including VSO, JSOC, as well as individual data sources such as GOES XRS time series and and is fully pluggable to add new data sources, i.e. DKIST. In anticipation of Solar Orbiter and the Parker Solar Probe, SunPy now provides a powerful way of representing coordinates, allowing conversion between coordinate systems and viewpoints of different instruments, including preliminary reprojection capabilities. Other new features including new timeseries capabilities with better support for concatenation and metadata, updated documentation and example gallery. SunPy is distributed through pip and conda and all of its code is publicly available (sunpy.org).

  15. Our Dynamic Sun (Hannes Alfvén Medal Lecture)

    Science.gov (United States)

    Priest, Eric

    2017-04-01

    The Sun, an object of worship for early civilisations, is the main source of light and life on Earth and of our space weather, with many subtle effects on our environment. The lecture will introduce you to the Sun and its dynamic phenomena, and will aim to show how our understanding of many aspects of the Sun has been revolutionized over the past few years by current spacecraft observations and models. Much of the dynamic behaviour is driven by the magnetic field since, in the outer atmosphere (or corona), it represents by far the largest source of energy. The interior of the Sun, revealed by solar seismology, possesses a strong shear layer at the base of the convection zone, where sunspot magnetic fields are generated. But a small-scale dynamo is also operating near the surface of the Sun, generating magnetic fields that thread the lowest layer of the solar atmosphere, the photosphere, in a turbulent convective state. Above the photosphere lies the highly dynamic fine-scale chromosphere and beyond that the rare corona at high temperatures exceeding one million degrees K. Magnetic mechanisms for heating the corona (an intriguing puzzle) will be described. Other puzzles include the structure of giant flux ropes, known as prominences, which have complex fine structure. Occasionally, they erupt and produce huge ejections of mass and magnetic field (coronal mass ejections), which can disrupt the space environment of the Earth. When such eruptions originate in active regions around sunspots, they are also associated with solar flares, where magnetic energy is converted to kinetic, heat and fast particle energy. A new theory will be presented for the origin of the twist that is observed in erupting prominences.

  16. SunSmart: Evaluation of a Pilot School-Based Sun Protection Intervention in Hispanic Early Adolescents

    Science.gov (United States)

    Miller, K. A.; Langholz, B. M.; Ly, T.; Harris, S. C.; Richardson, J. L.; Peng, D. H.; Cockburn, M. G.

    2015-01-01

    The incidence of melanoma is rising among Hispanic populations in the United States. The purpose of this study is to evaluate the impact of a pilot sun safety educational intervention conducted from 2006 to 2012 on Hispanic early adolescents in a high ultraviolet environment. Nineteen schools with high Hispanic enrollment were recruited from urban…

  17. ULYSSES comes full circle, before revisiting the Sun's poles

    Science.gov (United States)

    1998-04-01

    From its unique perspective, Ulysses has provided scientists with the very first all-round map of the heliosphere, the huge bubble in space filled by the Sun's wind. The Earth swims deep inside the heliosphere, and gusts and shocks in the solar wind can harm satellites, power supplies and ommunications. They may also affect our planet's weather. A better grasp of the solar weather in the heliosphere is therefore one of the major aims of ESA's science programme. In a project of international cooperation between ESA and NASA, Ulysses was launched towards Jupiter in October 1990 by the US space shuttle Discovery. Arriving in February 1992, Ulysses stole energy from the giant planet in a slingshot manoeuvre and was propelled back towards the Sun in an elongated orbit almost at right angles to the ecliptic plane, where the Earth and other planets circle the Sun. "This month Ulysses returns to the point in space where its out-of-ecliptic journey began, but Jupiter isn't there," explains Richard Marsden, ESA's project scientist for Ulysses. "Following its own inexorable path around the Sun, Jupiter is far away on the opposite side of the Solar System. So Ulysses' course will not be changed a second time. The spacecraft is now in effect a man-made comet, forever bound into a 6-year polar orbit around the Sun." Ulysses now starts its second orbit. It will travel over the poles of the Sun in 2000-2001 just as the count of dark sunspots is expected to reach a maximum. With its operational life extended for the Ulysses Solar Maximum Mission, the spacecraft will find the heliosphere much stormier than during its first orbit. Discoveries so far Like its mythical namesake, Ulysses has already had an eventful voyage of discovery. Its unique trajectory has provided the scientific teams with a new perspective, from far out in space and especially in the previously unknown regions of the heliosphere over the Sun's poles. Passing within 9.8 degrees of the polar axis, the highly

  18. [Historical origin of Jiu Tangshu·biography of Sun Simiao].

    Science.gov (United States)

    Song, Zhen-Min

    2012-09-01

    The book Datang Xinyu·Sun Simiao was compiled by Liu Su according to the original national historical papers of the Tang Dynasty which basically kept the features of national history. Based on this book and Binglishufu Xu (written by Lu Zhaolin) and Tanbinlu·Sun Simiao, Zhang Du sorted out the data about Sun Simiao and compiled the book Xuanshizhi·Sun Simiao (in which the three stories of his lifetime were made up). Jiu Tangshi·Sun Simiao was edited by historiographers in the Hou-Jin Dynasty according to the biography of Sun Simiao in Tang national history, and referring to the Datang Xinyu·Sun Simiao, Xuanshizhi·Sun Simiao, in which they only made a few adjustments on the basis of Xuanshizhi. Du Guangting compiled Xianzhuan Shiyi·Sun Simiao and Xuanshizhi·Sun Simiao and added three stories of gods and spirits about Sun Simiao after he became immortal. Taipingguangji of the North Song Dynasty was compiled according to Xianzhuan Shiyi·Sun Simiao and Xuanshizhi·Sun Simiao.

  19. Dissemination of go sun smart in outdoor recreation: effect of program exposure on sun protection of guests at high-altitude ski areas.

    Science.gov (United States)

    Walkosz, Barbara J; Buller, David B; Andersen, Peter A; Scott, Michael D; Dignan, Mark B; Cutter, Gary R; Liu, Xia; Maloy, Julie A

    2014-09-01

    Go Sun Smart is a theory-based health communication program designed to influence sun-protection behaviors of employees and guests at high-altitude ski areas to reduce skin cancer risk. The effects of Go Sun Smart, in a Phase IV dissemination randomized posttest-only trial, on sun-protection behaviors of ski area guests are reported. Program use was assessed by on-site observation and guest message exposure, and sun protection was measured in intercept surveys at ski areas. Dissemination strategy-enhanced versus basic-was not significantly related to sun safety practices. Additional analyses examined the relation between message exposure and guests' sun safety practices. Ski areas displaying at least 6 Go Sun Smart materials in guest-only areas and 9 Go Sun Smart materials throughout the area increased guests' message exposure. Higher message exposure within the high-use ski areas was associated with improved sun protection by guests but not within the low-use ski areas. The authors underscore the importance of program implementation and message exposure on the success of evidence-based health communication efforts applied industrywide.

  20. Simplification of Sun Tracking Mode to Gain High Concentration Solar Energy

    Directory of Open Access Journals (Sweden)

    Omar Aliman

    2007-01-01

    Full Text Available Power conversion from solar thermal energy to electrical energy is still very cost-intensive. Serious effort has to be given in the development of the concentrator or heliostat structure expenditure which contributing the most expensive component in a central receiver solar power plant. With current development to find alternatives and lower down the capital, a new mode of sun tracking has been developed and feasibility tested. As it applies a single stage collector replacing conventional double stages structure, the new technique has significantly benefits use in high temperature and high concentration solar energy applications. Meanwhile, the stationary or fixed target (receiver offers more convenient working environment for various applications. Large and heavy solar powered Stirling Engine could be placed at the stationary location. On the other advantage offers by the new technique, the optical alignment was reasonably easier and less time consuming.

  1. FREQUENCY SHIFTS OF RESONANT MODES OF THE SUN DUE TO NEAR-SURFACE CONVECTIVE SCATTERING

    Energy Technology Data Exchange (ETDEWEB)

    Bhattacharya, J.; Hanasoge, S.; Antia, H. M. [Department of Astronomy and Astrophysics, Tata Institute of Fundamental Research, Mumbai-400005 (India)

    2015-06-20

    Measurements of oscillation frequencies of the Sun and stars can provide important independent constraints on their internal structure and dynamics. Seismic models of these oscillations are used to connect structure and rotation of the star to its resonant frequencies, which are then compared with observations, the goal being that of minimizing the difference between the two. Even in the case of the Sun, for which structure models are highly tuned, observed frequencies show systematic deviations from modeled frequencies, a phenomenon referred to as the “surface term.” The dominant source of this systematic effect is thought to be vigorous near-surface convection, which is not well accounted for in both stellar modeling and mode-oscillation physics. Here we bring to bear the method of homogenization, applicable in the asymptotic limit of large wavelengths (in comparison to the correlation scale of convection), to characterize the effect of small-scale surface convection on resonant-mode frequencies in the Sun. We show that the full oscillation equations, in the presence of temporally stationary three-dimensional (3D) flows, can be reduced to an effective “quiet-Sun” wave equation with altered sound speed, Brünt–Väisäla frequency, and Lamb frequency. We derive the modified equation and relations for the appropriate averaging of 3D flows and thermal quantities to obtain the properties of this effective medium. Using flows obtained from 3D numerical simulations of near-surface convection, we quantify their effect on solar oscillation frequencies and find that they are shifted systematically and substantially. We argue therefore that consistent interpretations of resonant frequencies must include modifications to the wave equation that effectively capture the impact of vigorous hydrodynamic convection.

  2. The Spiral Arm Segments of the Galaxy within 3 kpc from the Sun: A Statistical Approach

    Science.gov (United States)

    Griv, Evgeny; Jiang, Ing-Guey; Hou, Li-Gang

    2017-08-01

    As can be reasonably expected, upcoming large-scale APOGEE, GAIA, GALAH, LAMOST, and WEAVE stellar spectroscopic surveys will yield rather noisy Galactic distributions of stars. In view of the possibility of employing these surveys, our aim is to present a statistical method to extract information about the spiral structure of the Galaxy from currently available data, and to demonstrate the effectiveness of this method. The model differs from previous works studying how objects are distributed in space in its calculation of the statistical significance of the hypothesis that some of the objects are actually concentrated in a spiral. A statistical analysis of the distribution of cold dust clumps within molecular clouds, H ii regions, Cepheid stars, and open clusters in the nearby Galactic disk within 3 kpc from the Sun is carried out. As an application of the method, we obtain distances between the Sun and the centers of the neighboring Sagittarius arm segment, the Orion arm segment in which the Sun is located, and the Perseus arm segment. Pitch angles of the logarithmic spiral segments and their widths are also estimated. The hypothesis that the collected objects accidentally form spirals is refuted with almost 100% statistical confidence. We show that these four independent distributions of young objects lead to essentially the same results. We also demonstrate that our newly deduced values of the mean distances and pitch angles for the segments are not too far from those found recently by Reid et al. using VLBI-based trigonometric parallaxes of massive star-forming regions.

  3. The COST example for outreach to the general public: I love my Sun

    Science.gov (United States)

    Tulunay, Yurdanur; Crosby, Norma Bock; Tulunay, Ersin; Calders, Stijn; Parnowski, Aleksei; Sulic, Desanka

    2013-01-01

    It is important to educate children about the important role that the Sun has in their lives. This paper presents an educational outreach tool entitled "I Love My Sun" that has been developed for school children in the approximate age range of 7 through 11 years. The main objective of this tool is to make children aware of space weather, the Sun, Sun-Earth relations and how they, the children, are part of this global picture. Children are given a lecture about the Sun. The lecture is preceded and followed by the children drawing a picture of the Sun. In this paper the background behind the "I Love My Sun" initiative is given and it is described how to perform an "I Love My Sun". The main results from events in Turkey, Belgium, Ukraine and Serbia are presented.

  4. Structure and expression of the maize (Zea mays L. SUN-domain protein gene family: evidence for the existence of two divergent classes of SUN proteins in plants

    Directory of Open Access Journals (Sweden)

    Simmons Carl R

    2010-12-01

    Full Text Available Abstract Background The nuclear envelope that separates the contents of the nucleus from the cytoplasm provides a surface for chromatin attachment and organization of the cortical nucleoplasm. Proteins associated with it have been well characterized in many eukaryotes but not in plants. SUN (Sad1p/Unc-84 domain proteins reside in the inner nuclear membrane and function with other proteins to form a physical link between the nucleoskeleton and the cytoskeleton. These bridges transfer forces across the nuclear envelope and are increasingly recognized to play roles in nuclear positioning, nuclear migration, cell cycle-dependent breakdown and reformation of the nuclear envelope, telomere-led nuclear reorganization during meiosis, and karyogamy. Results We found and characterized a family of maize SUN-domain proteins, starting with a screen of maize genomic sequence data. We characterized five different maize ZmSUN genes (ZmSUN1-5, which fell into two classes (probably of ancient origin, as they are also found in other monocots, eudicots, and even mosses. The first (ZmSUN1, 2, here designated canonical C-terminal SUN-domain (CCSD, includes structural homologs of the animal and fungal SUN-domain protein genes. The second (ZmSUN3, 4, 5, here designated plant-prevalent mid-SUN 3 transmembrane (PM3, includes a novel but conserved structural variant SUN-domain protein gene class. Mircroarray-based expression analyses revealed an intriguing pollen-preferred expression for ZmSUN5 mRNA but low-level expression (50-200 parts per ten million in multiple tissues for all the others. Cloning and characterization of a full-length cDNA for a PM3-type maize gene, ZmSUN4, is described. Peptide antibodies to ZmSUN3, 4 were used in western-blot and cell-staining assays to show that they are expressed and show concentrated staining at the nuclear periphery. Conclusions The maize genome encodes and expresses at least five different SUN-domain proteins, of which the PM3

  5. Understanding Space Weather: The Sun as a Variable Star

    Science.gov (United States)

    Strong, Keith; Saba, Julia; Kucera, Therese

    2012-01-01

    The Sun is a complex system of systems and until recently, less than half of its surface was observable at any given time and then only from afar. New observational techniques and modeling capabilities are giving us a fresh perspective of the solar interior and how our Sun works as a variable star. This revolution in solar observations and modeling provides us with the exciting prospect of being able to use a vastly increased stream of solar data taken simultaneously from several different vantage points to produce more reliable and prompt space weather forecasts. Solar variations that cause identifiable space weather effects do not happen only on solar-cycle timescales from decades to centuries; there are also many shorter-term events that have their own unique space weather effects and a different set of challenges to understand and predict, such as flares, coronal mass ejections, and solar wind variations.

  6. HARPS-N observes the Sun as a star

    CERN Document Server

    Dumusque, Xavier; Phillips, David F; Buchschacher, Nicolas; Cameron, Andrew Collier; Cecconi, Massimo; Charbonneau, David; Cosentino, Rosario; Ghedina, Adriano; Latham, David W; Li, Chih-Hao; Lodi, Marcello; Lovis, Christophe; Molinari, Emilio; Pepe, Francesco; Udry, Stephane; Sasselov, Dimitar; Szentgyorgyi, Andrew; Walsworth, Ronald

    2015-01-01

    Radial velocity perturbations induced by stellar surface inhomogeneities including spots, plages and granules currently limit the detection of Earth-twins using Doppler spectroscopy. Such stellar noise is poorly understood for stars other than the Sun because their surface is unresolved. In particular, the effects of stellar surface inhomogeneities on observed stellar radial velocities are extremely difficult to characterize, and thus developing optimal correction techniques to extract true stellar radial velocities is extremely challenging. In this paper, we present preliminary results of a solar telescope built to feed full-disk sunlight into the HARPS-N spectrograph, which is in turn calibrated with an astro-comb. This setup enables long-term observation of the Sun as a star with state-of-the-art sensitivity to radial velocity changes. Over seven days of observing in 2014, we show an average 50\\cms radial velocity rms over a few hours of observation. After correcting observed radial velocities for spot and...

  7. SU(N) multi-Skyrmions at finite volume

    Energy Technology Data Exchange (ETDEWEB)

    Canfora, Fabrizio [Centro de Estudios Cientificos (CECS), Casilla, Valdivia (Chile); Di Mauro, Marco; Naddeo, Adele [Universita di Salerno, Dipartimento di Fisica ' ' E.R. Caianiello' ' , Fisciano, SA (Italy); Kurkov, Maxim A. [Universita di Napoli Federico II, Dipartimento di Matematica e Applicazioni ' ' R. Caccioppoli' ' , Napoli (Italy)

    2015-09-15

    We study multi-soliton solutions of the fourdimensional SU(N) Skyrme model by combining the hedgehog ansatz for SU(N) based on the harmonic maps of S{sup 2} into CP{sup N-1} and a geometrical trick which allows to analyze explicitly finite-volume effects without breaking the relevant symmetries of the ansatz. The geometric set-up allows to introduce a parameter which is related to the ft Hooft coupling of a suitable large N limit, in which N → ∞ and the curvature of the background metric approaches zero, in such a way that their product is constant. The relevance of such a parameter to the physics of the system is pointed out. In particular, we discuss how the discrete symmetries of the configurations depend on it. (orig.)

  8. On the Path to SunShot - Executive Summary

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2016-05-01

    The halfway mark of the SunShot Initiative’s 2020 target date is a good time to take stock: How much progress has been made? What have we learned? What barriers and opportunities must still be addressed to ensure that solar technologies achieve cost parity in 2020 and realize their full potential in the decades beyond? To answer these questions, the Solar Energy Technology Office launched the On the Path to SunShot series in early 2015 in collaboration with the National Renewable Energy Laboratory (NREL) and with contributions from Lawrence Berkeley National Laboratory (LBNL), Sandia National Laboratories (SNL), and Argonne National Laboratory (ANL). The reports focus on the areas of technology development, systems integration, and market enablers.

  9. Radio emission of the sun at millimeter wavelengths

    Science.gov (United States)

    Nagnibeda, V. G.; Piotrovich, V. V.

    This review article deals with the radio emission originating from different solar atmospheric regions - the quiet solar atmosphere, active regions and solar flares. All experimental data of the quiet Sun brightness temperature at the region of 0.1 - 20 mm wavelength are summarized. The quiet Sun brightness distributions across the disk and values of the solar radio radius are reviewed. The properties of the sources of sunspot-associated active region emission and radio brightness depression associated with Hα-filaments are considered in comparison with observations at centimetre and optical domains. The observational properties of millimetre wave bursts and their correlations with similar phenomena at other domains are reviewed. Special reference is devoted to nearly 100% correlation impulsive radio bursts with hard X-ray bursts. Existence of the fine temporal structure containing many spikes with time scales up to 10 ms as well as observations of quasi-periodic millisecond oscillations are discussed.

  10. Quest for finding the lost siblings of the Sun

    CERN Document Server

    Liu, C; Feltzing, S; Martínez-Barbosa, C A; Bensby, T; Brown, A G A; Zwart, S F Portegies

    2014-01-01

    The aim of this paper is to find lost siblings of the Sun by analyzing high resolution spectra. Finding solar siblings will enable us to constrain the parameters of the parental cluster and the birth place of the Sun in the Galaxy. The solar siblings can be identified by accurate measurements of metallicity, stellar age and elemental abundances for solar neighbourhood stars. The solar siblings candidates were kinematically selected based on their proper motions, parallaxes and colours. Stellar parameters were determined through a purely spectroscopic approach and partly physical method, respectively. Comparing synthetic with observed spectra, elemental abundances were computed based on the stellar parameters obtained using a partly physical method. A chemical tagging technique was used to identify the solar siblings. We present stellar parameters, stellar ages, and detailed elemental abundances for Na, Mg, Al, Si, Ca, Ti, Cr, Fe, and Ni for 32 solar sibling candidates. Our abundances analysis shows that four ...

  11. Exact Diagonalization of Heisenberg SU(N) models.

    Science.gov (United States)

    Nataf, Pierre; Mila, Frédéric

    2014-09-19

    Building on advanced results on permutations, we show that it is possible to construct, for each irreducible representation of SU(N), an orthonormal basis labeled by the set of standard Young tableaux in which the matrix of the Heisenberg SU(N) model (the quantum permutation of N-color objects) takes an explicit and extremely simple form. Since the relative dimension of the full Hilbert space to that of the singlet space on n sites increases very fast with N, this formulation allows us to extend exact diagonalizations of finite clusters to much larger values of N than accessible so far. Using this method, we show that, on the square lattice, there is long-range color order for SU(5), spontaneous dimerization for SU(8), and evidence in favor of a quantum liquid for SU(10).

  12. Evidence That Solar Flares Drive Global Oscillations in the Sun

    Science.gov (United States)

    Karoff, C.; Kjeldsen, H.

    2008-05-01

    Solar flares are large explosions on the Sun's surface caused by a sudden release of magnetic energy. They are known to cause local short-lived oscillations traveling away from the explosion like water rings. Here we show that the energy in the solar acoustic spectrum is correlated with flares. This means that the flares drive global oscillations in the Sun in the same way that the entire Earth is set ringing for several weeks after a major earthquake such as the 2004 December Sumatra-Andaman one. The correlation between flares and energy in the acoustic spectrum of disk-integrated sunlight is stronger for high-frequency waves than for ordinary p-modes which are excited by the turbulence in the near-surface convection zone immediately beneath the photosphere.

  13. The Surprising History of Claims for Life on the Sun

    Science.gov (United States)

    Crowe, Michael J.

    2011-11-01

    Because astronomers are now convinced that it is impossible for life, especially intelligent life, to exist on the Sun and stars, it might be assumed that astronomers have always held this view. This paper shows that throughout most of the history of astronomy, some intellectuals, including a number of well-known astronomers, have advocated the existence of intelligent life on our Sun and thereby on stars. Among the more prominent figures discussed are Nicolas of Cusa, Giordano Bruno, William Whiston, Johann Bode, Roger Boscovich, William Herschel, Auguste Comte, Carl Gauss, Thomas Dick, John Herschel, and François Arago. One point in preparing this paper is to show differences between the astronomy of the past and that of the present.

  14. [Experience of professor Sun Liuhe in treating facial peripheral paralysis].

    Science.gov (United States)

    Lu, Mei; Zhang, Huan-huan; Zhang, Hui-fang

    2009-06-01

    Professor Sun Liuhe is engaged in medical service for over 40 years. He is deeply involved in research on intractable and complicated diseases. Especially, in treating facial paralysis, he makes diagnosis and treatment based on overall analysis of symptoms and causes, differentiation of syndrome for etiology. Without confining himself to ancient treatment methods, by applying both acupuncture and Chinese medicine, selecting auxiliary acupoints according to differentiation of meridians related to illness, as well as considering anatomy. Professor Sun holds ancient and modern therapeutic methods, brings forth ideas of using new acupoints to prevent perversion based on pulse tracings, and uses cutting therapy for the cases suffering from facial paralysis for a long time. This method can shorten treatment courses, to a great extent, and achieve good therapeutic effects on intractable facial paralysis, which has revealed distinctness of acupuncture therapy.

  15. The Role of the Magnetorotational Instability in the Sun

    CERN Document Server

    Kagan, Daniel

    2014-01-01

    We calculate growth rates for nonaxisymmetric instabilities including the magnetorotational instability (MRI) throughout the Sun. We first derive a dispersion relation for nonaxisymmetric instability including the effects of shear, convective buoyancy, and three diffusivities (thermal conductivity, resistivity, and viscosity). We then use a solar model evolved with the stellar evolution code MESA and angular velocity profiles determined by Global Oscillations Network Group (GONG) helioseismology to determine the unstable modes present at each location in the Sun and the associated growth rates. The overall instability has unstable modes throughout the convection zone and also slightly below it at middle and high latitudes. It contains three classes of modes: large-scale hydrodynamic convective modes, large-scale hydrodynamic shear modes, and small-scale magnetohydrodynamic (MHD) shear modes, which may be properly called MRI modes. While large-scale convective modes are the most rapidly growing modes in most o...

  16. HARPS-N OBSERVES THE SUN AS A STAR

    Energy Technology Data Exchange (ETDEWEB)

    Dumusque, Xavier; Glenday, Alex; Phillips, David F.; Charbonneau, David; Latham, David W.; Li, Chih-Hao; Sasselov, Dimitar; Szentgyorgyi, Andrew; Walsworth, Ronald [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Buchschacher, Nicolas; Lovis, Christophe; Pepe, Francesco; Udry, Stéphane [Observatoire Astronomique de l’Université de Genève, 51 Chemin des Maillettes, 1290 Sauverny (Switzerland); Cameron, Andrew Collier [SUPA, School of Physics and Astronomy, University of St. Andrews, North Haugh, St. Andrews, Fife, KY16 9SS (United Kingdom); Cecconi, Massimo; Cosentino, Rosario; Ghedina, Adriano; Lodi, Marcello; Molinari, Emilio, E-mail: xdumusque@cfa.harvard.edu [INAF—Fundación Galileo Galilei, Rambla José Ana Fernández Pérez 7, E-38712 Breña Baja (Spain)

    2015-12-01

    Radial velocity (RV) perturbations induced by stellar surface inhomogeneities including spots, plages and granules currently limit the detection of Earth-twins using Doppler spectroscopy. Such stellar noise is poorly understood for stars other than the Sun because their surface is unresolved. In particular, the effects of stellar surface inhomogeneities on observed stellar radial velocities are extremely difficult to characterize, and thus developing optimal correction techniques to extract true stellar radial velocities is extremely challenging. In this paper, we present preliminary results of a solar telescope built to feed full-disk sunlight into the HARPS-N spectrograph, which is in turn calibrated with an astro-comb. This setup enables long-term observation of the Sun as a star with state-of-the-art sensitivity to RV changes. Over seven days of observing in 2014, we show an average 50 cm s{sup −1} RV rms over a few hours of observation. After correcting observed radial velocities for spot and plage perturbations using full-disk photometry of the Sun, we lower by a factor of two the weekly RV rms to 60 cm s{sup −1}. The solar telescope is now entering routine operation, and will observe the Sun every clear day for several hours. We will use these radial velocities combined with data from solar satellites to improve our understanding of stellar noise and develop optimal correction methods. If successful, these new methods should enable the detection of Venus over the next two to three years, thus demonstrating the possibility of detecting Earth-twins around other solar-like stars using the RV technique.

  17. Capturing small asteroids into a Sun-Earth Lagrangian point

    Science.gov (United States)

    Lladó, Neus; Ren, Yuan; Masdemont, Josep J.; Gómez, Gerard

    2014-02-01

    In this paper we address the feasibility of capturing small Near-Earth Asteroids (NEAs) into the vicinity of the Sun-Earth L2 libration point using a continuous-thrust propulsion system assumed to be attached to the asteroid. The vicinity of this libration point is a gateway to the Earth-Moon neighborhood and using it for capture, or for transit, small NEAs could be interesting for mining or science purposes.

  18. Solar Energy Education. Reader, Part IV. Sun schooling

    Energy Technology Data Exchange (ETDEWEB)

    1981-05-01

    A collection of magazine articles which focus on solar energy is presented. This is the final book of the four part series of the Solar Energy Reader. The articles include brief discussions on energy topics such as the sun, ocean energy, methane gas from cow manure, and solar homes. Instructions for constructing a sundial and a solar stove are also included. A glossary of energy related terms is provided. (BCS)

  19. AV-95 Sun Devil: High-Speed Military Rotorcraft

    Science.gov (United States)

    1996-01-01

    The AV-95 Sun Devil must combine helicopter capabilities, such as vertical takeoff and landings (VTOL) and rotor-powered flight, along with long-duration cruise and high-speed dash capabilities unobtainable by conventional helicopters. To be able to perform both tasks, and perform them well, the AV-95 Sun Devil design incorporates several unconventional devices; the AV-95 uses two convertible turbofan engines, able to provide both shaft power for the main rotor and tall fan as well as jet thrust either separately or simultaneously. Other devices used for the AV-95 include a variable diameter main rotor and a blown flap. In helicopter mode, the AV-95 Sun Devil performs like a winged helicopter. The addition of wings to an attack helicopter results in two significant advantages. First, the addition of wings makes a helicopter more maneuverable than a wingless, but otherwise similar helicopter. Second, since the wings produce lift, rotor stall and compressibility effects can be significantly delayed at high tip velocities. In fixed-wing mode, the main rotor is completely off-loaded but slightly powered, and the rotor diameter has been minimized. The AV-95 Sun Devil has many advantages over other VTOL aircraft. The conversion process is simple and fast; conversion does not make the AV-95 vulnerable to enemy attack during conversion such as a tilt-wing or a tilt-rotor. Stop-rotor aircraft and a stowed rotor aircraft require heavy breaking of the rotor for conversion; this adds time for conversion and weight to the aircraft. Because the AV-95 never stops the rotor in flight, much weight is spared, and conversion is much simpler and faster.

  20. Estimation of surface insolation using sun-synchronous satellite data

    Science.gov (United States)

    Darnell, Wayne L.; Staylor, W. Frank; Gupta, Shashi K.; Denn, Fred M.

    1988-01-01

    A technique is presented for estimating insolation at the earth's surface using only sun-synchronous satellite data. The technique was tested by comparing the insolation results from year-long satellite data sets with simultaneous ground-measured insolation taken at five continental United States sites. Monthly average insolation values derived from the satellite data showed a standard error of 4.2 W/sq m, or 2.7 percent of the average ground insolation value.

  1. What Is the Source of Quiet Sun Transition Region Emission?

    Science.gov (United States)

    Schmit, D. J.; De Pontieu, Bart

    2016-11-01

    Dating back to the first observations of the on-disk corona, there has been a qualitative link between the photosphere’s magnetic network and enhanced transition-temperature plasma emission. These observations led to the development of a general model that describes emission structures through the partitioning of the atmospheric volume with different magnetic loop geometries that exhibit different energetic equilibria. Does the internetwork produce transition-temperature emission? What fraction of network flux connects to the corona? How does quiet Sun emission compare with low-activity Sun-like stars? In this work, we revisit the canonical model of the quiet Sun, with high-resolution observations from the Interface Region Imaging Spectrograph (IRIS) and HMI in hand, to address those questions. We use over 900 deep exposures of Si iv 1393 Å from IRIS along with nearly simultaneous HMI magnetograms to quantify the correlation between transition-temperature emission structures and magnetic field concentrations through a number of novel statistics. Our observational results are coupled with analysis of the Bifrost MHD model and a large-scale potential field model. Our results paint a complex portrait of the quiet Sun. We measure an emission signature in the distant internetwork that cannot be attributed to network contribution. We find that the dimmest regions of emission are not linked to the local vertical magnetic field. Using the MHD simulation, we categorize the emission contribution from cool mid-altitude loops and high-altitude coronal loops and discuss the potential emission contribution of spicules. Our results provide new constraints on the coupled solar atmosphere so that we can build on our understanding of how dynamic thermal and magnetic structures generate the observed phenomena in the transition region.

  2. Liquid Metallic Hydrogen: A Building Block for the Liquid Sun

    OpenAIRE

    Robitaille P.-M.

    2011-01-01

    Liquid metallic hydrogen provides a compelling material for constructing a condensed matter model of the Sun and the photosphere. Like diamond, metallic hydrogen might have the potential to be a metastable substance requiring high pressures for forma- tion. Once created, it would remain stable even at lower pressures. The metallic form of hydrogen was initially conceived in 1935 by Eugene Wigner and Hillard B. Huntington who indirectly anticipated its elevated critical temper...

  3. [Textual research on Newly Carved sun Zhenren's Qian jin fang].

    Science.gov (United States)

    Su, L

    1995-01-01

    As one of the ancient edition of Qian jin fang, this Newly Carved Sun Zhenren's Qian Jin Fang is far more authentic in the structure of its contents and its text, as compared to those editions of the Song Dynasty, and is, of course, closer to its original form and more reliable with textual significance. This article explores the distribution, characters of the edition and time of carving.

  4. Surya Namaskar (Sun Salutation: A Path to Good Health

    Directory of Open Access Journals (Sweden)

    Amit Vaibhav

    2016-07-01

    Full Text Available Surya Namaskar (Sun Salutation is an ancient and sacred yogic technique of India for expressing gratitude to the Sun. Surya Namaskar is a set of 12 Asanas (postures, It is done preferably in the morning while facing the rising sun. There are numerous health benefits of Surya Namaskar for different system of the body specially musculoskeletal, cardiovascular, gastrointestinal, nervous system, respiratory and endocrinal. The heart, liver, intestine, stomach, chest, throat, legs and backbone are main benefited organs. By practicing Surya Namaskar each and every cell of body get revitalize and regenerated, therefore it is highly recommended by all yoga experts for healthy routine life. The regular practice of Surya Namaskar improves blood circulation throughout the body, maintains health and makes the body disease-free. Regular practice of Surya Namaskar gives strength, flexibility and vitality to the body. Sun Salutation asanas help to burn extra body fat on belly, buttocks and back by modulating endocrinal system. It also helps to regulate menstrual cycles among women and also facilitate an easy childbirth. Apart from these benefits of Surya Namaskar also help to keep the mind stress free, calm and illuminated. Thus, a regular practice of Surya Namaskar is highly recommended to keep the body and mind healthy. Though the Surya Namaskar steps are very scientific and practical science ancient time but still it needs advance modern scientific justification to spread it globally, keeping this thing into the mind the present review has been framed to revalidate sacred steps of Surya Namaskar on the basis of available evidence based studies.

  5. Searching for Chambers and Caves in Teotihuacan's Sun Pyramid

    Science.gov (United States)

    Alfaro, R.; Arrieta, E.; Barba P., L.; Becerril, A. D.; Belmont, E.; Carrillo, I.; Cabrera M., J. I.; Esquivel, O.; Grabski, V.; López R., J. M.; Manzanilla N., L.; Martínez D., A.; Menchaca R., A.; Moreno, M.; Núñez C., R.; Plascencia, J. C.; Rangel, M.; Villoro, M.

    2003-06-01

    In this work a status report of a search for caves in the Sun pyramid in Teotihuacan, México is presented. From an archeological perspective the main goal is to gather evidence to determine whether the pyramid was a state or a funerary temple. The general layout of the detector that is being built is an updated version of the one originally proposed by Alvarez et al..

  6. Spring on the Sun: A New Cycle of Sunspots

    Science.gov (United States)

    Klotz, Irene

    2008-05-01

    Amateur German astronomer Samuel Heinrich Schwabe was searching for a planet inside Mercury's orbit when he made the serendipitous discovery of the Sun's cycle in 1843. Scientists later figured out that the cycle supplies the energy that drives space weather. But anticipating the start of a new 11-year solar cycle is a bit like waiting for spring: It's hard to tell sometimes when will be the year's final winter chill.

  7. Chemistry, sun, energy and environment; Chimie, soleil, energie et environnement

    Energy Technology Data Exchange (ETDEWEB)

    Bouchy, M. [Ecole Nationale Superieure des Industries Chimiques (ENSIC), 54 - Villers-les-Nancy (France); Enea, O. [Poitiers Univ., 86 (France); Flamant, G. [IMP-Odeillo-CNRS (France)] (and others)

    2000-07-01

    This document provides the 35 papers presented at the 'Chemistry, Sun, Energy and Environment' meeting, held February 3-4, 2000 in Saint-Avold, France. The main studied topic was the use of solar radiation for water treatment, volatile organic compounds decomposition and in some thermochemical processes. These research subjects are tackled in a fundamental and practical point of view. (O.M.)

  8. The effect of royal sun agaricus, agaricus brasiliensis S. Wasser et al., Extract on methyl Methanesulfonate caused genotoxicity in Drosophila melanogaster

    NARCIS (Netherlands)

    Savic, T.; Patenkovic, A.; Sokovic, M.; Glamoclija, J.; Andjelkovic, M.; Griensven, van L.J.L.D.

    2011-01-01

    The effect of culinary-medicinal Royal Sun Agaricus (Agaricus brasiliensis) hot water extract on methyl methane sulfonate (MMS) induced mutagenicity/genotoxity in Drosophila melanogaster was studied using a quick and broadly applicable in vivo assay, i.e., the wing somatic mutation and recombination

  9. Sun Tzu’s Art of War for Telecom : Telecom vs OTT from a Daoistic Perspective

    NARCIS (Netherlands)

    Stokking, H.M.; Strijkers, R.J.

    2012-01-01

    Sun Tzu's Art of War is a work of Chinese philosophy. It can be seen as a manual for warfare, but at the same time it is so much more. Sun Tzu's Art of War describes how the ultimate victory is one won without fighting. Any sector, including the telecommunications sector, may learn from Sun Tzu's wo

  10. Sun Tzu and the Art of Business Six Strategic Principles for Managers

    CERN Document Server

    McNeilly, Mark R

    2011-01-01

    More than two millennia ago the famous Chinese general Sun Tzu wrote the classic work on military strategy, The Art of War. Now, in a new edition of Sun Tzu and the Art of Business, Mark McNeilly shows how Sun Tzu's strategic principles can be applied to

  11. Sun Tzu’s Art of War for Telecom : Telecom vs OTT from a Daoistic Perspective

    NARCIS (Netherlands)

    Stokking, H.M.; Strijkers, R.J.

    2012-01-01

    Sun Tzu's Art of War is a work of Chinese philosophy. It can be seen as a manual for warfare, but at the same time it is so much more. Sun Tzu's Art of War describes how the ultimate victory is one won without fighting. Any sector, including the telecommunications sector, may learn from Sun Tzu's wo

  12. An autonomous low power high resolution micro-digital sun sensor

    NARCIS (Netherlands)

    Xie, N.; Theuwissen, A.J.P.

    2011-01-01

    Micro-Digital Sun Sensor (μDSS) is a sun detector which senses the respective angle between a satellite and the sun. It is composed of a solar cell power supply, a RF communication block and a CMOS Image Sensor (CIS) chip, which is called APS+. The paper describes the implementation of a prototype o

  13. 76 FR 20992 - Sun Chemical Corp.; Filing of Color Additive Petition

    Science.gov (United States)

    2011-04-14

    ... HUMAN SERVICES Food and Drug Administration Sun Chemical Corp.; Filing of Color Additive Petition AGENCY... announcing that Sun Chemical Corp. has filed a petition proposing that the color additive regulations for D&C... been filed by Sun Chemical Corp., 5020 Spring Grove Ave., Cincinnati, OH 45232. The petition...

  14. The Sun: A Star at the Center of Our Solar System

    Science.gov (United States)

    Adams, Mitzi L.

    2016-01-01

    There is a star at the center of our solar system! But what is a star? How do stars work? What are the characteristics of our Sun and how are these traits different from other stars? How does the Sun compare to stars such as Betelgeuse and Rigel? "Will the Sun end its life with a bang or a whimper?"

  15. An autonomous low power high resolution micro-digital sun sensor

    NARCIS (Netherlands)

    Xie, N.; Theuwissen, A.J.P.

    2011-01-01

    Micro-Digital Sun Sensor (μDSS) is a sun detector which senses the respective angle between a satellite and the sun. It is composed of a solar cell power supply, a RF communication block and a CMOS Image Sensor (CIS) chip, which is called APS+. The paper describes the implementation of a prototype

  16. MWA Observations of Solar Radio Bursts and the Quiet Sun

    Science.gov (United States)

    Cairns, I.; Oberoi, D.; Morgan, J.; Bastian, T.; Bhatnagar, S.; Bisi, M.; Benkevitch, L.; Bowman, J.; Donea, A.; Giersch, O.; Jackson, B.; Chat, G. L.; Golub, L.; Hariharan, K.; Herne, D.; Kasper, J.; Kennewell, J.; Lonsdale, C.; Lobzin, V.; Matthews, L.; Mohan, A.; Padmanabhan, J.; Pankratius, V.; Pick, M.; Subramanian, P.; Ramesh, R.; Raymond, J.; Reeves, K.; Rogers, A.; Sharma, R.; Tingay, S.; Tremblay, S.; Tripathi, D.; Webb, D.; White, S.; Abidin, Z. B. Z.

    2017-01-01

    A hundred hours of observing time for solar observations is requested during the 2017-A observing semester. These data will be used to address science objectives for solar burst science (Goal A), studies of weak non-thermal radiation (Goal B) and quiet sun science (Goal C). Goal A will focus on detailed investigations of individual events seen in the MWA data, using the unsurpassed spectroscopic imaging ability of the MWA to address some key solar physics questions. Detailed observations of type II bursts, of which MWA has observed two, will be one focus, with MWA polarimetric imaging observations of type III bursts another focus. Goal B will address studies of the numerous short lived and narrow band emission features, significantly weaker than those seen by most other instruments revealed by the MWA. These emission features do not resemble any known types of solar bursts, but are possible signatures of "nanoflares" which have long been suspected to play a role in coronal heating. A large database of these events is needed to be able to reliably estimate their contribution to coronal heating. These observations will contribute to this database. Goal C will focus on characterizing the Sun's background thermal emission, their short and long term variability and looking for evidence of a scattering disc around the Sun.

  17. The Mount Wilson Observatory S-index of the Sun

    Science.gov (United States)

    Egeland, Ricky; Soon, Willie; Baliunas, Sallie; Hall, Jeffrey C.; Pevtsov, Alexei A.; Bertello, Luca

    2017-01-01

    The most commonly used index of stellar magnetic activity is the instrumental flux scale of singly ionized calcium H & K line core emission, S, developed by the Mount Wilson Observatory (MWO) HK Project, or the derivative index {R}{HK}\\prime . Accurately placing the Sun on the S scale is important for comparing solar activity to that of the Sun-like stars. We present previously unpublished measurements of the reflected sunlight from the Moon using the second-generation MWO HK photometer during solar cycle 23 and determine cycle minimum {S}23,\\min =0.1634+/- 0.0008, amplitude {{Δ }}{S}23=0.0143+/- 0.0012, and mean =0.1701+/- 0.0005. By establishing a proxy relationship with the closely related National Solar Observatory Sacramento Peak calcium K emission index, itself well correlated with the Kodaikanal Observatory plage index, we extend the MWO S time series to cover cycles 15–24 and find on average =0.1621+/- 0.0008, =0.0145+/- 0.0012, =0.1694+/- 0.0005. Our measurements represent an improvement over previous estimates that relied on stellar measurements or solar proxies with non-overlapping time series. We find good agreement from these results with measurements by the Solar-Stellar Spectrograph at Lowell Observatory, an independently calibrated instrument, which gives us additional confidence that we have accurately placed the Sun on the S-index flux scale.

  18. Absolute spectral radiance responsivity calibration of sun photometers

    Energy Technology Data Exchange (ETDEWEB)

    Xu Qiuyun; Zheng Xiaobing; Zhang Wei; Wang Xianhua; Li Jianjun; Li Xin [Key Laboratory of Optical Calibration and Characterization, Chinese Academy of Sciences, Hefei 230031 (China); Li Zhengqiang [Laboratoire d' Optique Atmospherique, Universite Lille 1, Villeneuve d' Ascq 59655 (France) and State Key Laboratory of Remote Sensing Science, Institute of Remote Sensing Applications, Chinese Academy of Sciences, Beijing 100101 (China)

    2010-03-15

    Sun photometers are designed to measure direct solar irradiance and diffused sky radiance for the purpose of atmospheric parameters characterization. A sun photometer is usually calibrated by using a lamp-illuminated integrating sphere source for its band-averaged radiance responsivity, which normally has an uncertainty of 3%-5% at present. Considering the calibration coefficients may also change with time, a regular high precision calibration is important to maintain data quality. In this paper, a tunable-laser-based facility for spectral radiance responsivity calibration has been developed at the Key Laboratory of Optical Calibration and Characterization, Chinese Academy of Sciences. A reference standard radiance radiometer, calibrated against cryogenic radiometer, is used to determine the radiance from a laser-illuminated integrating sphere source. Spectral radiance responsivity of CIMEL CE318-2 sun photometer is calibrated using this new calibration system with a combined standard uncertainty of about 0.8%. As a validation, the derived band-averaged radiance responsivity are compared to that from a Goddard Space Flight Center lamp-based sphere calibration and good agreements (difference <1.4%) are found from 675 to 1020 nm bands.

  19. Absolute spectral radiance responsivity calibration of sun photometers.

    Science.gov (United States)

    Xu, Qiuyun; Zheng, Xiaobing; Li, Zhengqiang; Zhang, Wei; Wang, Xianhua; Li, Jianjun; Li, Xin

    2010-03-01

    Sun photometers are designed to measure direct solar irradiance and diffused sky radiance for the purpose of atmospheric parameters characterization. A sun photometer is usually calibrated by using a lamp-illuminated integrating sphere source for its band-averaged radiance responsivity, which normally has an uncertainty of 3%-5% at present. Considering the calibration coefficients may also change with time, a regular high precision calibration is important to maintain data quality. In this paper, a tunable-laser-based facility for spectral radiance responsivity calibration has been developed at the Key Laboratory of Optical Calibration and Characterization, Chinese Academy of Sciences. A reference standard radiance radiometer, calibrated against cryogenic radiometer, is used to determine the radiance from a laser-illuminated integrating sphere source. Spectral radiance responsivity of CIMEL CE318-2 sun photometer is calibrated using this new calibration system with a combined standard uncertainty of about 0.8%. As a validation, the derived band-averaged radiance responsivity are compared to that from a Goddard Space Flight Center lamp-based sphere calibration and good agreements (difference <1.4%) are found from 675 to 1020 nm bands.

  20. Poynting-Robertson-like Drag at the Sun's Surface

    Science.gov (United States)

    Cunnyngham, Ian; Emilio, Marcelo; Kuhn, Jeff; Scholl, Isabelle; Bush, Rock

    2017-02-01

    The Sun's internal rotation Ω (r ,Θ ) has previously been measured using helioseismology techniques and found to be a complex function of colatitude θ and radius r . From helioseismology and observations of apparently "rooted" solar magnetic tracers, we know that the surface rotates more slowly than much of the interior. The cause of this slow-down is not understood, but it is important for understanding stellar rotation generally and any plausible theory of the solar interior. A new analysis using 5-min solar p -mode limb oscillations as a rotation "tracer" finds an even larger velocity gradient in a thin region at the top of the photosphere. This shear occurs where the solar atmosphere radiates energy and angular momentum. We suggest that the net effect of the photospheric angular momentum loss is similar to Poynting-Robertson "photon braking" on, for example, Sun-orbiting dust. The resultant photospheric torque is readily computed and, over the Sun's lifetime, is found to be comparable to the apparent angular momentum deficit in the near-surface shear layer.

  1. The Faint Young Sun Paradox: A Simplified Thermodynamic Approach

    Directory of Open Access Journals (Sweden)

    F. Angulo-Brown

    2012-01-01

    Full Text Available Classical models of the Sun suggest that the energy output in the early stage of its evolution was 30 percent less than today. In this context, radiative balance alone between The Sun and the Earth was not sufficient to explain the early presence of liquid water on Earth’s surface. This difficulty is called the faint young Sun paradox. Many proposals have been published to solve this paradox. In the present work, we propose an oversimplified finite-time thermodynamic approach that describes the air convective cells in the Earth atmosphere. This model introduces two atmospheric modes of thermodynamic performance: a first mode consisting in the maximization of the power output of the convective cells (maximum power regime and a second mode that consists in maximizing a functional representing a good trade-off between power output and entropy production (the ecological regime. Within the assumptions of this oversimplified model, we present different scenarios of albedo and greenhouse effects that seem realistic to preserve liquid water on the Earth in the early stage of formation.

  2. Growing tropical forage legumes in full sun and silvopastoral systems

    Directory of Open Access Journals (Sweden)

    Saulo Alberto do Carmo Araújo

    2017-02-01

    Full Text Available Growth was evaluated three tropical forage legumes in two cropping systems: silvopastoral system (SSP and full sun. A completely randomized design was adopted in factorial three legumes (estilosanthes cv. Campo Grande (Stylozanthes macrocephala x Stylozanthes capitata, tropical kudzu (Pueraria phaseoloides (Roxb. Benth and macrotiloma (Macrotyloma axillare cv. Java x two farming systems, with 4 repetitions. A eucalyptus SSP already deployed, with spatial arrangement of 12 x 2 m between trees was used. Legumes were planted in January 2014 a uniform cut being made in May 2014. The court assessment was carried out 125 days after the uniformity cut. There was difference for mass production of dry legumes (PMMSL between cultivation systems, evidencing increased productivity in the farming full sun. The macrotiloma showed higher PMSL (5.29 kg DM ha-1 cut-1, while the kudzu obtained the lowest yield (3.42 kg DM ha-1 cut-1 in the sun growing full. The cultivation of legumes in SSP increased the levels of mineral matter, crude protein and neutral detergent fiber. The shade provided by the SSP caused a reduction in the mass of dry matter production, but also altered the chemical composition of the studied legumes.

  3. Dynamics of the global Sun from interior to outer atmosphere

    Science.gov (United States)

    Schrijver, Carolus

    2012-07-01

    The Sun is the only star whose magnetic activity can be resolved in stunning detail. Current observational capabilities range from full-sphere coverage to measurements of details more than 10,000 times smaller than that. Acoustic waves enable us to probe the dynamics of the deep interior, while heliospheric imagers reveal the evolution of coronal mass ejections to beyond the orbit of the Earth. This comprehensive view of a magnetically active star, complemented by rapid advances in numerical capabilities, are revealing how the coupled system of interior, atmosphere, and heliosphere evolves dynamically through the sunspot cycle, punctuated by flux emergence, field eruptions, and irradiance variations. The Sun is not only a touchstone for the interpretation of many astrophysical observations, but its variability affects our society in more ways than we routinely appreciate; this drives a need to understand it well enough that forecasts of its electromagnetic weather can be made. This lecture, starting from the very different perspectives of astrophysical curiosity and societal need, focuses on trends near the frontier of our knowledge about the Sun's functioning as a global system.

  4. Design of solar cell lighting and sun tracking system

    Energy Technology Data Exchange (ETDEWEB)

    Khaing, A.A. [Mandalay Technological Univ., Mandalay (Myanmar); Ministry of Science, Yangon (Myanmar)

    2008-07-01

    A solar cell lighting and sun tracking system was discussed and the characteristics of solar cells were studied. An SM50H solar module was analyzed with a maximum power rating of 50 W and a current rate of 3.15 A. The main components of the system include solar cells, charged controllers, and a sun tracking system. The solar tracker is an automatic control system designed to track the solar modules in relation to the sun's direction. A linear drive actuator was used to track the modules with an energy consumption rate between 24 and 36 DC voltages. Power output solar cell equations were presented along with a review of batteries used for stationary and portable solar energy equipment. Issues related to cost of tracking systems were discussed. System sizing recommendations were provided, and solar cell design requirements were reviewed. A comparison of tracking and fixed solar energy systems was presented for a day in Yangon, Myanmar. It was concluded that solar tracking systems can be used to provide energy in rural and remote areas. 18 refs., 4 tabs., 5 figs.

  5. Energy Input Flux in the Global Quiet-Sun Corona

    Science.gov (United States)

    Mac Cormack, Cecilia; Vásquez, Alberto M.; López Fuentes, Marcelo; Nuevo, Federico A.; Landi, Enrico; Frazin, Richard A.

    2017-07-01

    We present first results of a novel technique that provides, for the first time, constraints on the energy input flux at the coronal base (r ˜ 1.025 R ⊙) of the quiet Sun at a global scale. By combining differential emission measure tomography of EUV images, with global models of the coronal magnetic field, we estimate the energy input flux at the coronal base that is required to maintain thermodynamically stable structures. The technique is described in detail and first applied to data provided by the Extreme Ultraviolet Imager instrument, on board the Solar TErrestrial RElations Observatory mission, and the Atmospheric Imaging Assembly instrument, on board the Solar Dynamics Observatory mission, for two solar rotations with different levels of activity. Our analysis indicates that the typical energy input flux at the coronal base of magnetic loops in the quiet Sun is in the range ˜0.5-2.0 × 105 (erg s-1 cm-2), depending on the structure size and level of activity. A large fraction of this energy input, or even its totality, could be accounted for by Alfvén waves, as shown by recent independent observational estimates derived from determinations of the non-thermal broadening of spectral lines in the coronal base of quiet-Sun regions. This new tomography product will be useful for the validation of coronal heating models in magnetohydrodinamic simulations of the global corona.

  6. Moon and Sun shadow observation with IceCube

    Energy Technology Data Exchange (ETDEWEB)

    Bos, Fabian; Tenholt, Frederik; Becker-Tjus, Julia [Theoretische Physik, Ruhr-Universitaet, Bochum (Germany); Westerhoff, Stefan [University of Wisconsin, Madison (United States); Collaboration: IceCube-Collaboration

    2015-07-01

    The analysis of the Moon shadow is a standard method in IceCube to determine the angular resolution and absolute pointing capabilities of the IceCube detector at the geographic South Pole. The Sun has not been used as a calibrator thus far, as its shadow is expected to be influenced by the solar magnetic field, which deflects the cosmic rays near the solar surface. This, on the other hand, provides indirect pieces of information on the magnetic field structure of the Sun. This talk shows a first analysis of the Sun shadow with IceCube data. The analysis is based on the data of the detector configurations with 79 (IC79) and 86 strings (IC86) from 2010 through 2012. To examine the shadows, a binned method is used to compare all events from one on-source with two off-source windows. For the IC40 and IC59 configuration a deficit with a statistical significance of more than 6σ was observed.

  7. Biomimetic photo-actuation: sensing, control and actuation in sun-tracking plants.

    Science.gov (United States)

    Dicker, M P M; Rossiter, J M; Bond, I P; Weaver, P M

    2014-09-01

    Although the actuation mechanisms that drive plant movement have been investigated from a biomimetic perspective, few studies have looked at the wider sensing and control systems that regulate this motion. This paper examines photo-actuation-actuation induced by, and controlled with light-through a review of the sun-tracking functions of the Cornish Mallow. The sun-tracking movement of the Cornish Mallow leaf results from an extraordinarily complex-yet extremely elegant-process of signal perception, generation, filtering and control. Inspired by this process, a concept for a simplified biomimetic analogue of this leaf is proposed: a multifunctional structure employing chemical sensing, signal transmission, and control of composite hydrogel actuators. We present this multifunctional structure, and show that the success of the concept will require improved selection of materials and structural design. This device has application in the solar-tracking of photovoltaic panels for increased energy yield. More broadly it is envisaged that the concept of chemical sensing and control can be expanded beyond photo-actuation to many other stimuli, resulting in new classes of robust solid-state devices.

  8. Sun energy, heat radiation and daylight on surfaces with different orientation

    Energy Technology Data Exchange (ETDEWEB)

    Aydinli, S.

    1981-05-01

    A calculation method is presented which allows to predetermine illuminances and irradiances incident on surfaces with any orientation originating from sun, clear sky, overcast sky, and the average sky which can be expected over a period of several years. The results of the calculations give the necessary data for the effective use of sun energy and daylight for interior lighting. A modified formula for the average sky may be applied for the calculation of the average irradiances evaluating the irradiances for the clear sky and the overcast sky conditions which can be expected according to the long term local sunshine duration (probability of sunshine) and local average values of the turbidity factor as a function of the day of the year and the hour of the day. In order to make the method applicable for any place the computed values are compared with measuring data available for surfaces with different orientations. Finally the annual radiant exposure on surfaces with different orientations is determined for Berlin.

  9. Dynamical systems for modeling evolution of the magnetic field of the Sun, stars and planets

    Science.gov (United States)

    Popova, E.

    2016-12-01

    The magnetic activity of the Sun, stars and planets are connected with a dynamo process based on the combined action of the differential rotation and the alpha-effect. Application of this concept allows us to get different types of solutions which can describe the magnetic activity of celestial bodies. We investigated the dynamo model with the meridional circulation by the low-mode approach. This approach is based on an assumption that the magnetic field can be described by non-linear dynamical systems with a relatively small number of parameters. Such non-linear dynamical systems are based on the equations of dynamo models. With this method dynamical systems have been built for media which contains the meridional flow and thickness of the spherical shell where dynamo process operates. It was shown the possibility of coexistence of quiasi-biennial oscillations, 22-year cycle, and grand minima of magnetic activity which is consistent with the observational data for the solar activity. We obtained different regimes (oscillations, vacillations, dynamo-bursts) depending on a value of the dynamo-number, the meridional circulation, and thickness of the spherical shell. We discuss features of these regimes and compare them with the observed features of the magnetic fields of the Sun, stars and Earth. We built theoretical paleomagnetic time scale and butterfly-diagrams for the helicity and toroidal magnetic field for different regimes.

  10. Similar features that appear both on the dynamic spectra of the Sun and Jupiter

    Science.gov (United States)

    Litvinenko, G.; Konovalenko, A.; Zakharenko, V.; Vinogradov, V.; Dorovsky, V.; Melnik, V.; Shaposhnikov, V.; Rucker, H. O.; Zarka, Ph.

    2013-09-01

    At present, the physical nature of the basic components of the solar sporadic radiation has been well studied and reliably identified non-equilibrium particle emission mechanisms responsible for their origin [1, 2, and references therein]. Jupiter decameter emission (DAM) represents an extraordinary astrophysical phenomenon which is characterized by an unusual complexity of the frequency-temporal structure of its dynamic spectra. It should be noted that since of its discovering many problems in the theory of the Jovian decameter emission have been successfully investigated and solved [3, and references therein]. Nevertheless, a great number of physical features of this phenomenon still remain unclear. It should be noted that the quasi-similar in shape features appear in the dynamic spectra both in the Sun and the Jovian radio emission. We hope that future research of the similar properties in the emission spectra of Jupiter and the Sun and analogy between the plasma processes in the solar corona and magnetosphere of Jupiter can allow also define the similar features in the radiation mechanisms of these cosmic objects. One of the promising approaches to investigating features of the Jovian DAM emission and the decameter solar radiation is application of novel experimental techniques with a further detailed analysis of the obtained data.

  11. New polynomially exact integration rules on U(N) and SU(N)

    CERN Document Server

    Ammon, Andreas; Jansen, Karl; Leövey, Hernan; Volmer, Julia

    2016-01-01

    In lattice Quantum Field Theory, we are often presented with integrals over polynomials of coefficients of matrices in U(N) or SU(N) with respect to the Haar measure. In some physical situations, e.g., in presence of a chemical potential, these integrals are numerically very difficult since their integrands are highly oscillatory which manifests itself in form of the sign problem. In these cases, Monte Carlo methods often fail to be adequate, rendering such computations practically impossible. We propose a new class of integration rules on U(N) and SU(N) which are derived from polynomially exact rules on spheres. We will examine these quadrature rules and their efficiency at the example of a 0+1 dimensional QCD for a non-zero quark mass and chemical potential. In particular, we will demonstrate the failure of Monte Carlo methods in such applications and that we can obtain polynomially exact, arbitrary precision results using the new integration rules.

  12. Existence and Stability the Lagrangian point $L_4$ for the Earth-Sun system under a relativistic framework

    CERN Document Server

    Perdomo, Oscar M

    2016-01-01

    It is well known that, from the Newtonian point of view, the Lagrangian point $L_4$ in the circular restricted three body is stable if $\\mu< \\frac{1}{18}(9-\\sqrt{19})\\approx 0.03852$. In this paper we will provide a formula that allows us to compute the eigenvalues of the matrix that determines the stability of the equilibrium points of a family of ordinary differential equations. As an application we will show that, under the relativistic framework, the Lagrangian point $L_4$ is also stable for the Sun-Earth system. Similar arguments show the stability for $L_4$ not only for the Sun-Earth system but for systems coming from a range of values for $\\mu$ similar to those in the Newtonian restricted three body problem.

  13. Maximizing Output Power of a Solar Panel via Combination of Sun Tracking and Maximum Power Point Tracking by Fuzzy Controllers

    Directory of Open Access Journals (Sweden)

    Mohsen Taherbaneh

    2010-01-01

    Full Text Available In applications with low-energy conversion efficiency, maximizing the output power improves the efficiency. The maximum output power of a solar panel depends on the environmental conditions and load profile. In this paper, a method based on simultaneous use of two fuzzy controllers is developed in order to maximize the generated output power of a solar panel in a photovoltaic system: fuzzy-based sun tracking and maximum power point tracking. The sun tracking is performed by changing the solar panel orientation in horizontal and vertical directions by two DC motors properly designed. A DC-DC converter is employed to track the solar panel maximum power point. In addition, the proposed system has the capability of the extraction of solar panel I-V curves. Experimental results present that the proposed fuzzy techniques result in increasing of power delivery from the solar panel, causing a reduction in size, weight, and cost of solar panels in photovoltaic systems.

  14. Quest for the lost siblings of the Sun

    Science.gov (United States)

    Liu, C.; Ruchti, G.; Feltzing, S.; Martínez-Barbosa, C. A.; Bensby, T.; Brown, A. G. A.; Portegies Zwart, S. F.

    2015-03-01

    Aims: The aim of this paper is to find lost siblings of the Sun by analyzing high resolution spectra. Finding solar siblings will enable us to constrain the parameters of the parental cluster and the birth place of the Sun in the Galaxy. Methods: The solar siblings can be identified by accurate measurements of metallicity, stellar age and elemental abundances for solar neighbourhood stars. The solar siblings candidates were kinematically selected based on their proper motions, parallaxes and colours. Stellar parameters were determined through a purely spectroscopic approach and partly physical method, respectively. Comparing synthetic with observed spectra, elemental abundances were computed based on the stellar parameters obtained using a partly physical method. A chemical tagging technique was used to identify the solar siblings. Results: We present stellar parameters, stellar ages, and detailed elemental abundances for Na, Mg, Al, Si, Ca, Ti, Cr, Fe, and Ni for 32 solar sibling candidates. Our abundances analysis shows that four stars are chemically homogenous together with the Sun. Technique of chemical tagging gives us a high probability that they might be from the same open cluster. Only one candidate - HIP 40317 - which has solar metallicity and age could be a solar sibling. We performed simulations of the Sun's birth cluster in analytical Galactic model and found that most of the radial velocities of the solar siblings lie in the range -10 ≤ Vr ≤ 10 km s-1, which is smaller than the radial velocity of HIP 40317 (Vr = 34.2 km s-1), under different Galactic parameters and different initial conditions of the Sun's birth cluster. The sibling status for HIP 40317 is not directly supported by our dynamical analysis. Based on observations made with Nordic Optical Telescope at La Palma under programme 44-014. Based on observations made with ESO VLT Kueyen Telescope at the Paranal observatory under program me ID 085.C-0062(A), 087.D-0010(A), and 088.B-0820(A

  15. Sun behaviour after cutaneous malignant melanoma: a study based on ultraviolet radiation measurements and sun diary data.

    Science.gov (United States)

    Idorn, L W; Datta, P; Heydenreich, J; Philipsen, P A; Wulf, H C

    2013-02-01

    It has been reported that patients with cutaneous malignant melanoma (CMM) can lower their risk of a second primary melanoma by limiting recreational sun exposure. Previous studies based on questionnaires and objective surrogate measurements indicate that before their diagnosis, patients with CMM are exposed to higher ultraviolet radiation (UVR) doses than controls, followed by a reduction after diagnosis. In a prospective, observational case-control study, we aimed to assess sun exposure after diagnosis of CMM by objective measurements to substantiate advice about sun behaviour. The study population consisted of 24 patients recently diagnosed with CMM during the 7 months preceding the start of the study; 51 controls who matched these recently diagnosed patients in age, sex, occupation and constitutive skin type; and 29 patients diagnosed with CMM between 12 months and 6 years before the start of the study. During a summer season participants filled in sun exposure diaries daily and wore personal electronic UVR dosimeters in a wristwatch that continuously measured time-stamped UVR doses in standard erythema dose. The UVR dose of recently diagnosed patients on days with body exposure was one-third lower, and the number of days using sunscreen was double that of matched controls. However, in patients diagnosed more than 12 months earlier, the UVR dose on days with body exposure was one-third higher and the number of days using sunscreen was half that of recently diagnosed patients. Patients with CMM limited their UVR dose on days with body exposure, and by using sunscreen further reduced UVR reaching the skin, although only immediately after diagnosis. © 2012 The Authors. BJD © 2012 British Association of Dermatologists.

  16. Solar winds surfs waves in the Sun's atmosphere!

    Science.gov (United States)

    1999-07-01

    The fact that this electrified plasma speeds up to almost 3 million kilometres per hour as it leaves the Sun - twice as fast as originally predicted - has been known for years. The interpretation of how it happens is the real and surprising novelty: "The waves in the Sun's atmosphere are produced by vibrating solar magnetic field lines, which give solar wind particles a push just like an ocean wave gives a surfer a ride" said Dr John Kohl, principal investigator for the Ultraviolet Coronal Spectrometer (UVCS) - the instrument among the 12 aboard SOHO which gathered the data - and for the Spartan 201 mission. The outermost solar atmosphere, or corona, is only seen from Earth during a total eclipse of the Sun, when it appears as a shimmering, white veil surrounding the black lunar disc. The corona is an extremely tenuous, electrically charged gas, known as plasma, that flows throughout the solar system as the solar wind. The waves are formed by rapidly vibrating magnetic fields in the coronal plasma. They are called magneto - hydro - dynamic (MHD) waves and are believed to accelerate the solar wind. The solar wind is made up of electrons and ions, electrically charged atoms that have lost electrons. The electric charge of the solar wind particles forces them to travel along invisible lines of magnetic force in the corona. The particles spiral around the magnetic field lines as they rush into space. "The magnetic field acts like a violin string: when it's touched, it vibrates. When the Sun's magnetic field vibrates with a frequency equal to that of the particle spiraling around the magnetic field, it heats it up, producing a force that accelerates the particle upward and away from the Sun," says Dr. Ester Antonucci, an astronomer at the observatory of Turin, Italy, and co-investigator for SOHO's UVCS an instrument developed with considerable financial support by the Italian Space Agency, ASI. In a way this is similar to what happens if two people hold a string at

  17. Comprehensive Performance Analysis of Sun Tracker for Solar Energy%太阳能发电阳光跟踪器综合性能分析

    Institute of Scientific and Technical Information of China (English)

    刘鹏; 陈海; 毛伙南; 郭金基; 梁洞庭; 郭诚; 王美芳; 曾玲玲

    2013-01-01

      The solar energy performance under the control of the sun tracker was tested. The system design of sun tracker and control push rod were introduced. The calculation of sun angle,its working principle,and operation function were discussed. Finally,application example was introduced.%  进行阳光跟踪器控制下太阳能电池板发电的对比测试;介绍阳光跟踪器及控制电动推杆系统设计;讨论太阳光角度的计算,分析其工作原理,检验其运行的功能;最后给出实例。

  18. 孙光荣教授“三联药对”组方思想在变应性血管炎中的应用%Preliminary Study of Application of Professor Sun Guangrong’s prescription thought“Compatibility of Three drugs”in Treating Allergic Vasculitis

    Institute of Scientific and Technical Information of China (English)

    刘勤建

    2014-01-01

    Allergic vasculitis belongs to vascular inflammation and necrosis disease. The cause of the disease is not clear. It is clinically thought that infection, drug allergy, serum sickness and other factors are related to the occurrence of allergic vasculitis. Allergic vasculitis involves the vascular in the superficial dermis of patients and results in a vascular necrosis in skin. In serious cases, the illness will accumulate in other organs, which is a serious threat to the life quality of the patients. Professor Sun Guangrong has been in clinical research of TCM for many years. He created the thought of “compatibility of three drugs”. Professor Sun thinks the causes of allergic vasculitis include several factors such as heredity, qi stagnation, blood stasis, phlegm and toxin accumulation and depression. In the treatment, supplementing Qi and activating blood circulation, soothing liver and relievingYu, clearing heat and detoxifying, promoting Qi circulation and resolving phlegm should be the main methods. In drug prescription, Danshen, astragalus, American ginseng should be adopted as the king medicine, the radix ranunculi ternati, tulip, Herba Scutellariae barbatae should be the minister medicine. This paper mainly analyzes the way of professor Sun Guangrong’s thought“compatibility of three drugs”in treating allergic vasculitis.%变应性血管炎属于血管炎症坏死性疾病,发病原因暂未明确,临床认为变应性血管炎的发生与感染、药物变态、血清病变等因素相关,变应性血管炎会累及患者真皮上部血管,致使皮肤出现血管坏死,情况严重时,病情会累及其他内脏,严重地威胁患者的生存质量。孙光荣教授在中医临床研究工作上有着多年的历史,创设了“三联药对”思想。孙光荣教授认为,变应性血管炎发病原因与遗传、气滞、血瘀、毒聚、痰凝、抑郁等因素相关,在治疗方式上,应该以益气活血、疏肝解

  19. Measuring sun exposure in epidemiological studies: Matching the method to the research question.

    Science.gov (United States)

    King, Laura; Xiang, Fan; Swaminathan, Ashwin; Lucas, Robyn M

    2015-12-01

    Sun exposure has risks and benefits for health. Testing these associations requires tools for measuring sun exposure that are feasible and relevant to the time-course of the health outcome. Recent sun exposure, e.g. the last week, is best captured by dosimeters and sun diaries. These can also be used for medium-term sun exposure e.g. over several weeks, but incur a high participant burden. Self-reported data on "typical time outdoors" for working and non-working days, is less detailed and not influenced by day-to-day variation. Over a longer period, e.g. the lifetime, or for particular life stages, proxies of sun exposure, such as latitude of residence or ambient ultraviolet (UV) radiation levels (from satellites or ground-level monitoring) can be used, with additional detail provided by lifetime sun exposure calendars that include locations of residence, usual time outdoors, and detail of sunburn episodes. Objective measures of lifetime sun exposure include microtopography of sun-exposed skin (e.g. using silicone casts) or conjunctival UV autofluorescence. Potential modifiers of the association between sun exposure and the health outcome, such as clothing coverage and skin colour, may also need to be measured. We provide a systematic approach to selecting sun exposure measures for use in epidemiological health research.

  20. The Sun's Journey Through the Local Interstellar Medium: The PaleoLISM and Paleoheliosphere

    CERN Document Server

    Frisch, P C

    2006-01-01

    Over the recent past, the galactic environment of the Sun has differed substantially from today. Sometime within the past ~130,000 years, and possibly as recent as ~56,000 years ago, the Sun entered the tenuous tepid partially ionized interstellar material now flowing past the Sun. Prior to that, the Sun was in the low density interior of the Local Bubble. As the Sun entered the local ISM flow, we passed briefly through an interface region of some type. The low column densities of the cloud now surrounding the solar system indicate that heliosphere boundary conditions will vary from opacity considerations alone as the Sun moves through the cloud. These variations in the interstellar material surrounding the Sun affected the paleoheliosphere.