WorldWideScience

Sample records for sun sensor heading

  1. Micro technology based sun sensor

    DEFF Research Database (Denmark)

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

    2003-01-01

    various payloads and platforms. The conventional and commercial actuators and attitude sensors are in most cases not suited for these satellites, which again lead to new design considerations. Another important property is the launch cost, which can be kept relatively low as a result of the concept....... This fact enables students to get hands-on experience with satellite systems design and project management. This paper describes the attitude control and determination system of a Danish student satellite (DTUsat), with main focus on the two-axis MOEMS sun sensor developed. On the magnetotorquer controlled...... 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...

  2. 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.

  3. Protective head of sensors

    International Nuclear Information System (INIS)

    Liska, K.; Anton, P.

    1987-01-01

    The discovery concerns the protective heads of diagnostic assemblies of nuclear power plants for conductors of the sensors from the fuel and control parts of the said assemblies. A detailed description is presented of the design of the protective head which, as compared with the previous design, allows quick and simple assembly with reduced risk of damaging the sensors. The protective head may be used for diagnostic assemblies both in power and in research reactors and it will be used for WWER reactor assemblies. (A.K.). 3 figs

  4. BepiColombo fine sun sensor

    Science.gov (United States)

    Boslooper, Erik; van der Heiden, Nico; Naron, Daniël.; Schmits, Ruud; van der Velde, Jacob Jan; van Wakeren, Jorrit

    2017-11-01

    Design, development and verification of the passive Fine Sun Sensor (FSS) for the BepiColombo spacecraft is described. Major challenge in the design is to keep the detector at acceptable temperature levels while exposed to a solar flux intensity exceeding 10 times what is experienced in Earth orbit. A mesh type Heat Rejection Filter has been developed. The overall sensor design and its performance verification program is described.

  5. Self-Powered Sun Sensor Microsystems

    NARCIS (Netherlands)

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

    2009-01-01

    An analog sun sensor has been designed based on shade profile proportional to the angle of incidence of incoming light projected onto a 2×2 array of photodiodes. This concept enables an autonomous self-powered optical system with two the main functions (electrical power generation for the amplifier

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

    DEFF Research Database (Denmark)

    Bhanderi, Dan

    -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...

  7. 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

  8. 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

  9. CRUQS: A Miniature Fine Sun Sensor for Nanosatellites

    Science.gov (United States)

    Heatwole, Scott; Snow, Carl; Santos, Luis

    2013-01-01

    A new miniature fine Sun sensor has been developed that uses a quadrant photodiode and housing to determine the Sun vector. Its size, mass, and power make it especially suited to small satellite applications, especially nanosatellites. Its accuracy is on the order of one arcminute, and it will enable new science in the area of nanosatellites. The motivation for this innovation was the need for high-performance Sun sensors in the nanosatellite category. The design idea comes out of the LISS (Lockheed Intermediate Sun Sensor) used by the sounding rocket program on their solar pointing ACS (Attitude Control System). This system uses photodiodes and a wall between them. The shadow cast by the Sun is used to determine the Sun angle. The new sensor takes this concept and miniaturizes it. A cruciform shaped housing and a surface-mount quadrant photodiode package allow for a two-axis fine Sun sensor to be packaged into a space approx.1.25xl x0.25 in. (approx.3.2x2.5x0.6 cm). The circuitry to read the photodiodes is a simple trans-impedance operational amplifier. This is much less complex than current small Sun sensors for nanosatellites that rely on photo-arrays and processing of images to determine the Sun center. The simplicity of the circuit allows for a low power draw as well. The sensor consists of housing with a cruciform machined in it. The cruciform walls are 0.5-mm thick and the center of the cruciform is situated over the center of the quadrant photodiode sensor. This allows for shadows to be cast on each of the four photodiodes based on the angle of the Sun. A simple operational amplifier circuit is used to read the output of the photodiodes as a voltage. The voltage output of each photodiode is summed based on rows and columns, and then the values of both rows or both columns are differenced and divided by the sum of the voltages for all four photodiodes. The value of both difference over sums for the rows and columns is compared to a table or a polynomial fit

  10. Linear wide angle sun sensor for spinning satellites

    Science.gov (United States)

    Philip, M. P.; Kalakrishnan, B.; Jain, Y. K.

    1983-08-01

    A concept is developed which overcomes the defects of the nonlinearity of response and limitation in range exhibited by the V-slit, N-slit, and crossed slit sun sensors normally used for sun elevation angle measurements on spinning spacecraft. Two versions of sensors based on this concept which give a linear output and have a range of nearly + or - 90 deg of elevation angle are examined. Results are presented for the application of the twin slit version of the sun sensor in the three Indian satellites, Rohini, Apple, and Bhaskara II, which was successfully used for spin rate control and spin axis orientation control corrections as well as for sun elevation angle and spin period measurements.

  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. Sun-Direction Estimation Using a Partially Underdetermined Set of Coarse Sun Sensors

    Science.gov (United States)

    O'Keefe, Stephen A.; Schaub, Hanspeter

    2015-09-01

    A comparison of different methods to estimate the sun-direction vector using a partially underdetermined set of cosine-type coarse sun sensors (CSS), while simultaneously controlling the attitude towards a power-positive orientation, is presented. CSS are commonly used in performing power-positive sun-pointing and are attractive due to their relative inexpensiveness, small size, and reduced power consumption. For this study only CSS and rate gyro measurements are available, and the sensor configuration does not provide global triple coverage required for a unique sun-direction calculation. The methods investigated include a vector average method, a combination of least squares and minimum norm criteria, and an extended Kalman filter approach. All cases are formulated such that precise ground calibration of the CSS is not required. Despite significant biases in the state dynamics and measurement models, Monte Carlo simulations show that an extended Kalman filter approach, despite the underdetermined sensor coverage, can provide degree-level accuracy of the sun-direction vector both with and without a control algorithm running simultaneously. If no rate gyro measurements are available, and rates are partially estimated from CSS, the EKF performance degrades as expected, but is still able to achieve better than 10∘ accuracy using only CSS measurements.

  13. Laboratory test of an APS-based sun sensor prototype

    Science.gov (United States)

    Rufino, Giancarlo; Perrotta, Alessandro; Grassi, Michele

    2017-11-01

    This paper deals with design and prototype development of an Active Pixel Sensor - based miniature sun sensor and a laboratory facility for its indoor test and calibration. The miniature sun sensor is described and the laboratory test facility is presented in detail. The major focus of the paper is on tests and calibration of the sensor. Two different calibration functions have been adopted. They are based, respectively, on a geometrical model, which has required least-squares optimisation of system physical parameters estimates, and on neural networks. Calibration results are presented for the above solutions, showing that accuracy in the order of 0.01° has been achieved. Neural calibration functions have attained better performance thanks to their intrinsic auto-adaptive structure.

  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

  15. Digital design update for a sun sensor on a chip

    NARCIS (Netherlands)

    Mert, O.

    2014-01-01

    In the beginning of one year project work at Moog-Bradford, the scope of my assignment was coordination of the firmware development activities as defined in the Sun Sensor on a Chip (SSOAC) proposal for ESA GSTP-5 program. As the time progressed in the proposal evaluation process, my project scope

  16. Low-power high-accuracy micro-digital sun sensor by means of a CMOS image sensor

    NARCIS (Netherlands)

    Xie, N.; Theuwissen, A.J.P.

    2013-01-01

    A micro-digital sun sensor (?DSS) is a sun detector which senses a satellite’s instant attitude angle with respect to the sun. The core of this sensor is a system-on-chip imaging chip which is referred to as APS+. The APS+ integrates a CMOS active pixel sensor (APS) array of 368×368??pixels , a

  17. Development of a low-cost sun sensor for nanosatellites

    Science.gov (United States)

    Antonello, Andrea; Olivieri, Lorenzo; Francesconi, Alessandro

    2018-03-01

    Sun sensors represent a common and reliable technology for attitude determination, employed in many space missions thanks to their limited size and weight. Typically, two-axis digital Sun sensors employ an array of active pixels arranged behind a small aperture; the position of the sunlight's spot allows to determine the direction of the Sun. With the advent of smaller vehicles such as CubeSats and Nanosats, there is the need to further reduce the size and weight of such devices: as a trade-off, this usually results in the curtail of the performances. Nowadays, state of the art Sun sensors for CubeSats have resolutions of about 0.5°, with fields of view in the ±45° to ±90° range, with off-the-self prices of several thousands of dollars. In this work we introduce a novel low-cost miniaturized Sun sensor, based on a commercial CMOS camera detector; its main feature is the reduced size with respect to state-of-the-art sensors developed from the same technology, making it employable on CubeSats. The sensor consists of a precisely machined pinhole with a 10 μm circular aperture, placed at a distance of 7 mm from the CMOS. The standoff distance and casing design allow for a maximum resolution of less than 0.03°, outperforming most of the products currently available for nano and pico platforms; furthermore, the nature of the technology allows for reduced size and lightweight characteristics. The design, development and laboratory tests of the sensor are here introduced, starting with the definition of the physical model, the geometrical layout and its theoretical resolution; a more accurate model was then developed in order to account for the geometrical deviations and deformations of the pinhole-projected light-spot, as well as to account for the background noise and disturbances to the electronics. Finally, the laboratory setup is presented along with the test campaigns: the results obtained are compared with the simulations, allowing for the validation of the

  18. 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 (?DSS) 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

  19. 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

  20. MiniDSS: a low-power and high-precision miniaturized digital sun sensor

    NARCIS (Netherlands)

    Boer, B.M. de; Durkut, M.; Laan, E.; Hakkesteegt, H.; Theuwissen, A.; Xie, N.; Leijtens, J.L.; Urquijo, E.; Bruins, P.

    2012-01-01

    A high-precision and low-power miniaturized digital sun sensor has been developed at TNO. The single-chip sun sensor comprises an application specific integrated circuit (ASIC) on which an active pixel sensor (APS), read-out and processing circuitry as well as communication circuitry are combined.

  1. Analysis of earth albedo effect on sun sensor measurements based on theoretical model and mission experience

    Science.gov (United States)

    Brasoveanu, Dan; Sedlak, Joseph

    1998-01-01

    Analysis of flight data from previous missions indicates that anomalous Sun sensor readings could be caused by Earth albedo interference. A previous Sun sensor study presented a detailed mathematical model of this effect. The model can be used to study the effect of both diffusive and specular reflections and to improve Sun angle determination based on perturbed Sun sensor measurements, satellite position, and an approximate knowledge of attitude. The model predicts that diffuse reflected light can cause errors of up to 10 degrees in Coarse Sun Sensor (CSS) measurements and 5 to 10 arc sec in Fine Sun Sensor (FSS) measurements, depending on spacecraft orbit and attitude. The accuracy of these sensors is affected as long as part of the illuminated Earth surface is present in the sensor field of view. Digital Sun Sensors (DSS) respond in a different manner to the Earth albedo interference. Most of the time DSS measurements are not affected, but for brief periods of time the Earth albedo can cause errors which are a multiple of the sensor least significant bit and may exceed one degree. This paper compares model predictions with Tropical Rainfall Measuring Mission (TRMM) CSS measurements in order to validate and refine the model. Methods of reducing and mitigating the impact of Earth albedo are discussed. ne CSS sensor errors are roughly proportional to the Earth albedo coefficient. Photocells that are sensitive only to ultraviolet emissions would reduce the effective Earth albedo by up to a thousand times, virtually eliminating all errors caused by Earth albedo interference.

  2. Modeling Earth Albedo Currents on Sun Sensors for Improved Vector Observations

    DEFF Research Database (Denmark)

    Bhanderi, Dan

    2006-01-01

    Earth albedo influences vector measurements of the solar line of sight vector, due to the induced current on in the photo voltaics of Sun sensors. Although advanced digital Sun sensors exist, these are typically expensive and may not be suited for satellites in the nano or pico-class. Previously...... an Earth albedo model, based on reflectivity data from NASA's Total Ozone Mapping Spectrometer project, has been published. In this paper the proposed model is presented, and the model is sought validated by comparing simulated data with telemetry from the Danish Ørsted satellite. A novel method...... for modeling Sun sensor output by incorporating the Earth albedo model is presented. This model utilizes the directional information of in the Earth albedo model, which is achieved by Earth surface partitioning. This allows accurate simulation of the Sun sensor output and the results are consistent with Ørsted...

  3. MiniDSS: a low-power and high-precision miniaturized digital sun sensor

    Science.gov (United States)

    de Boer, B. M.; Durkut, M.; Laan, E.; Hakkesteegt, H.; Theuwissen, A.; Xie, N.; Leijtens, J. L.; Urquijo, E.; Bruins, P.

    2017-11-01

    A high-precision and low-power miniaturized digital sun sensor has been developed at TNO. The single-chip sun sensor comprises an application specific integrated circuit (ASIC) on which an active pixel sensor (APS), read-out and processing circuitry as well as communication circuitry are combined. The design was optimized for low recurrent cost. The sensor is albedo insensitive and the prototype combines an accuracy in the order of 0.03° with a mass of just 72 g and a power consumption of only 65 mW.

  4. 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.

  5. Accurate and wide field of view MEMS-based sun sensor for industrial applications

    OpenAIRE

    Delgado, Francisco; Quero, J.M.; Garcia Ortega, Juan; López Tarrida, Cristina; Ortega Villasclaras, Pablo Rafael; Bermejo Broto, 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...

  6. Attitude estimation from magnetometer and earth-albedo-corrected coarse sun sensor measurements

    Science.gov (United States)

    Appel, Pontus

    2005-01-01

    For full 3-axes attitude determination the magnetic field vector and the Sun vector can be used. A Coarse Sun Sensor consisting of six solar cells placed on each of the six outer surfaces of the satellite is used for Sun vector determination. This robust and low cost setup is sensitive to surrounding light sources as it sees the whole sky. To compensate for the largest error source, the Earth, an albedo model is developed. The total albedo light vector has contributions from the Earth surface which is illuminated by the Sun and visible from the satellite. Depending on the reflectivity of the Earth surface, the satellite's position and the Sun's position the albedo light changes. This cannot be calculated analytically and hence a numerical model is developed. For on-board computer use the Earth albedo model consisting of data tables is transferred into polynomial functions in order to save memory space. For an absolute worst case the attitude determination error can be held below 2∘. In a nominal case it is better than 1∘.

  7. Infrared Non-Contact Head Sensor for Control of Wheelchair Movements

    DEFF Research Database (Denmark)

    Christensen, Henrik Vie; Garcia, Juan Carlos

    2005-01-01

    This paper presents a new human-machine interface for controlling a wheelchair by head movements. The position of the head is determined by use of infrared sensors, with no parts attached to the head of the user. The placement of the infrared sensors are behind the head of the user, so that the f......This paper presents a new human-machine interface for controlling a wheelchair by head movements. The position of the head is determined by use of infrared sensors, with no parts attached to the head of the user. The placement of the infrared sensors are behind the head of the user, so...

  8. Risk Assessment of Cassini Sun Sensor Integrity Due to Hypervelocity Impact of Saturn Dust Particles

    Science.gov (United States)

    Lee, Allan Y.

    2016-01-01

    A sophisticated interplanetary spacecraft, Cassini is one of the heaviest and most sophisticated interplanetary spacecraft humans have ever built and launched. Since achieving orbit at Saturn in 2004, Cassini has collected science data throughout its four-year prime mission (2004-08), and has since been approved for first and second extended missions through September 2017. In late 2016, the Cassini spacecraft will begin a daring set of ballistic orbits that will hop the rings and dive between the upper atmosphere of Saturn and its innermost D-ring twenty-two times. The "dusty" environment of the inner D-ring region the spacecraft must fly through is hazardous because of the possible damage that dust particles, travelling at speeds as high as 31.4 km/s, can do to spacecraft hardware. During hazardous proximal ring-plane crossings, the Cassini mission operation team plans to point the high-gain antenna to the RAM vector in order to protect most of spacecraft instruments from the incoming energetic ring dust particles. However, this particular spacecraft attitude will expose two Sun sensors (that are mounted on the antenna dish) to the incoming dust particles. High-velocity impacts on the Sun sensor cover glass might penetrate the 2.54-mm glass cover of the Sun sensor. Even without penetration damage, craters created by these impacts on the surface of the cover glass will degrade the transmissibility of light through it. Apart from being directly impacted by the dust particles, the Sun sensors are also threatened by some fraction of ricochet ejecta that are produced by dust particle impacts on the large antenna dish (made of graphite fiber epoxy composite material). Finally, the spacecraft attitude control system must cope with disturbances due to both the translational and angular impulses imparted on the large antenna dish and the long magnetometer boom by the incoming high-velocity projectiles. Analyses performed to quantify the risks the Sun sensors must contend

  9. A geometric model of a V-slit Sun sensor correcting for spacecraft wobble

    Science.gov (United States)

    Mcmartin, W. P.; Gambhir, S. S.

    1994-01-01

    A V-Slit sun sensor is body-mounted on a spin-stabilized spacecraft. During injection from a parking or transfer orbit to some final orbit, the spacecraft may not be dynamically balanced. This may result in wobble about the spacecraft spin axis as the spin axis may not be aligned with the spacecraft's axis of symmetry. While the widely used models in Spacecraft Attitude Determination and Control, edited by Wertz, correct for separation, elevation, and azimuthal mounting biases, spacecraft wobble is not taken into consideration. A geometric approach is used to develop a method for measurement of the sun angle which corrects for the magnitude and phase of spacecraft wobble. The algorithm was implemented using a set of standard mathematical routines for spherical geometry on a unit sphere.

  10. 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.

  11. 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.

  12. An error compensation method for a linear array sun sensor with a V-shaped slit

    International Nuclear Information System (INIS)

    Fan, Qiao-yun; Tan, Xiao-feng

    2015-01-01

    Existing methods of improving measurement accuracy, such as polynomial fitting and increasing pixel numbers, cannot guarantee high precision and good miniaturization specifications of a microsun sensor at the same time. Therefore, a novel integrated and accurate error compensation method is proposed. A mathematical error model is established according to the analysis results of all the contributing factors, and the model parameters are calculated through multi-sets simultaneous calibration. The numerical simulation results prove that the calibration method is unaffected by installation errors introduced by the calibration process, and is capable of separating the sensor’s intrinsic and extrinsic parameters precisely, and obtaining accurate and robust intrinsic parameters. In laboratorial calibration, the calibration data are generated by using a two-axis rotation table and a sun simulator. The experimental results show that owing to the proposed error compensation method, the sun sensor’s measurement accuracy is improved by 30 times throughout its field of view (±60°  ×  ±60°), with a RMS error of 0.1°. (paper)

  13. Cassini Operational Sun Sensor Risk Management During Proximal Orbit Saturn Ring Plane Crossings

    Science.gov (United States)

    Bates, David M.

    2016-01-01

    NASA's Cassini Spacecraft, launched on October 15th, 1997 which arrived at Saturn on June 30th, 2004, is the largest and most ambitious interplanetary spacecraft in history. As the first spacecraft to achieve orbit at Saturn, Cassini has collected science data throughout its four-year prime mission (2004–08), and has since been approved for a first and second extended mission through 2017. As part of the final extended missions, Cassini will begin an aggressive and exciting campaign of high inclination, low altitude flybys within the inner most rings of Saturn, skimming Saturn’s outer atmosphere, until the spacecraft is finally disposed of via planned impact with the planet. This final campaign, known as the proximal orbits, requires a strategy for managing the Sun Sensor Assembly (SSA) health, the details of which are presented in this paper.

  14. Assessment of MODIS sun-sensor geometry variations effect on observed NDVI using MSG SEVIRI geostationary data

    DEFF Research Database (Denmark)

    Fensholt, R.; Sandholt, I.; Proud, Simon Richard

    2010-01-01

    The quality of Earth observation (EO) based vegetation monitoring has improved during recent years, which can be attributed to the enhanced sensor design of new satellites such as MODIS (Moderate Resolution Imaging Spectroradiometer) on Terra and Aqua. It is however expected that sun-sensor geome......The quality of Earth observation (EO) based vegetation monitoring has improved during recent years, which can be attributed to the enhanced sensor design of new satellites such as MODIS (Moderate Resolution Imaging Spectroradiometer) on Terra and Aqua. It is however expected that sun......-sensor geometry variations will have a more visible impact on the Normalized Difference Vegetation Index (NDVI) from MODIS compared to earlier data sources, since noise related to atmosphere and sensor calibration is substantially reduced in the MODIS data stream. For this reason, the effect of varying MODIS......, including a red and NIR band, and the high temporal resolution (15 min) of data, enabling MSG data to be used as a reference for estimating MODIS surface reflectance and NDVI variations caused by varying sun-sensor geometry. The study was performed on data covering West Africa for periods of lowest possible...

  15. A sun-crown-sensor model and adapted C-correction logic for topographic correction of high resolution forest imagery

    Science.gov (United States)

    Fan, Yuanchao; Koukal, Tatjana; Weisberg, Peter J.

    2014-10-01

    Canopy shadowing mediated by topography is an important source of radiometric distortion on remote sensing images of rugged terrain. Topographic correction based on the sun-canopy-sensor (SCS) model significantly improved over those based on the sun-terrain-sensor (STS) model for surfaces with high forest canopy cover, because the SCS model considers and preserves the geotropic nature of trees. The SCS model accounts for sub-pixel canopy shadowing effects and normalizes the sunlit canopy area within a pixel. However, it does not account for mutual shadowing between neighboring pixels. Pixel-to-pixel shadowing is especially apparent for fine resolution satellite images in which individual tree crowns are resolved. This paper proposes a new topographic correction model: the sun-crown-sensor (SCnS) model based on high-resolution satellite imagery (IKONOS) and high-precision LiDAR digital elevation model. An improvement on the C-correction logic with a radiance partitioning method to address the effects of diffuse irradiance is also introduced (SCnS + C). In addition, we incorporate a weighting variable, based on pixel shadow fraction, on the direct and diffuse radiance portions to enhance the retrieval of at-sensor radiance and reflectance of highly shadowed tree pixels and form another variety of SCnS model (SCnS + W). Model evaluation with IKONOS test data showed that the new SCnS model outperformed the STS and SCS models in quantifying the correlation between terrain-regulated illumination factor and at-sensor radiance. Our adapted C-correction logic based on the sun-crown-sensor geometry and radiance partitioning better represented the general additive effects of diffuse radiation than C parameters derived from the STS or SCS models. The weighting factor Wt also significantly enhanced correction results by reducing within-class standard deviation and balancing the mean pixel radiance between sunlit and shaded slopes. We analyzed these improvements with model

  16. Application of Optical Flow Sensors for Dead Reckoning, Heading Reference, Obstacle Detection, and Obstacle Avoidance

    Science.gov (United States)

    2015-09-01

    motion tracking and one sensor for object detection in association with an Arduino microcontroller , we built an indoor ground robot capable of...one sensor for motion tracking and one sensor for object detection in association with an Arduino microcontroller , we built an indoor ground robot...the vehicle from the generated data delivered by the optical sensor to an Arduino microcontroller . The microcontroller controls the speed, heading

  17. Angular velocity determination of spinning solar sails using only a sun sensor

    Directory of Open Access Journals (Sweden)

    Kun Zhai

    2017-02-01

    Full Text Available The direction of the sun is the easiest and most reliable observation vector for a solar sail running in deep space exploration. This paper presents a new method using only raw measurements of the sun direction vector to estimate angular velocity for a spinning solar sail. In cases with a constant spin angular velocity, the estimation equation is formed based on the kinematic model for the apparent motion of the sun direction vector; the least-squares solution is then easily calculated. A performance criterion is defined and used to analyze estimation accuracy. In cases with a variable spin angular velocity, the estimation equation is developed based on the kinematic model for the apparent motion of the sun direction vector and the attitude dynamics equation. Simulation results show that the proposed method can quickly yield high-precision angular velocity estimates that are insensitive to certain measurement noises and modeling errors.

  18. Balanced Cluster Head Selection Based on Modified k-Means in a Distributed Wireless Sensor Network

    OpenAIRE

    Periyasamy, Sasikumar; Khara, Sibaram; Thangavelu, Shankar

    2016-01-01

    A major problem with Wireless Sensor Networks (WSNs) is the maximization of effective network lifetime through minimization of energy usage in the network nodes. A modified k-means (Mk-means) algorithm for clustering was proposed which includes three cluster heads (simultaneously chosen) for each cluster. These cluster heads (CHs) use a load sharing mechanism to rotate as the active cluster head, which conserves residual energy of the nodes, thereby extending network lifetime. Moreover, it re...

  19. Video Analysis Verification of Head Impact Events Measured by Wearable Sensors.

    Science.gov (United States)

    Cortes, Nelson; Lincoln, Andrew E; Myer, Gregory D; Hepburn, Lisa; Higgins, Michael; Putukian, Margot; Caswell, Shane V

    2017-08-01

    Wearable sensors are increasingly used to quantify the frequency and magnitude of head impact events in multiple sports. There is a paucity of evidence that verifies head impact events recorded by wearable sensors. To utilize video analysis to verify head impact events recorded by wearable sensors and describe the respective frequency and magnitude. Cohort study (diagnosis); Level of evidence, 2. Thirty male (mean age, 16.6 ± 1.2 years; mean height, 1.77 ± 0.06 m; mean weight, 73.4 ± 12.2 kg) and 35 female (mean age, 16.2 ± 1.3 years; mean height, 1.66 ± 0.05 m; mean weight, 61.2 ± 6.4 kg) players volunteered to participate in this study during the 2014 and 2015 lacrosse seasons. Participants were instrumented with GForceTracker (GFT; boys) and X-Patch sensors (girls). Simultaneous game video was recorded by a trained videographer using a single camera located at the highest midfield location. One-third of the field was framed and panned to follow the ball during games. Videographic and accelerometer data were time synchronized. Head impact counts were compared with video recordings and were deemed valid if (1) the linear acceleration was ≥20 g, (2) the player was identified on the field, (3) the player was in camera view, and (4) the head impact mechanism could be clearly identified. Descriptive statistics of peak linear acceleration (PLA) and peak rotational velocity (PRV) for all verified head impacts ≥20 g were calculated. For the boys, a total recorded 1063 impacts (2014: n = 545; 2015: n = 518) were logged by the GFT between game start and end times (mean PLA, 46 ± 31 g; mean PRV, 1093 ± 661 deg/s) during 368 player-games. Of these impacts, 690 were verified via video analysis (65%; mean PLA, 48 ± 34 g; mean PRV, 1242 ± 617 deg/s). The X-Patch sensors, worn by the girls, recorded a total 180 impacts during the course of the games, and 58 (2014: n = 33; 2015: n = 25) were verified via video analysis (32%; mean PLA, 39 ± 21 g; mean PRV, 1664

  20. Head ballistocardiogram based on wireless multi-location sensors.

    Science.gov (United States)

    Onizuka, Kohei; Sodini, Charles G

    2015-08-01

    Recently a wearable BCG monitoring technique based on an accelerometer worn at the ear was demonstrated to replace a conventional bulky BCG acquisition system. In this work, a multi-location wireless vital signs monitor was developed, and at least two common acceleration vectors correlating to sitting-BCG were found in the supine position by using head PPG signal as a reference for eight healthy human subjects. The head side amplitude in the supine position is roughly proportional to the sitting amplitude that is in turn proportional to the stroke volume. Signal processing techniques to identify J-waves in a subject having small amplitude was also developed based on the two common vectors at the head side and top.

  1. Energy efficient distributed cluster head scheduling scheme for two tiered wireless sensor network

    Directory of Open Access Journals (Sweden)

    G. Kannan

    2015-07-01

    Full Text Available Wireless Sensor Network (WSN provides a significant contribution in the emerging fields such as ambient intelligence and ubiquitous computing. In WSN, optimization and load balancing of network resources are critical concern to provide the intelligence for long duration. Since clustering the sensor nodes can significantly enhance overall system scalability and energy efficiency this paper presents a distributed cluster head scheduling (DCHS algorithm to achieve the network longevity in WSN. The major novelty of this work is that the network is divided into primary and secondary tiers based on received signal strength indication of sensor nodes from the base station. The proposed DCHS supports for two tier WSN architecture and gives suggestion to elect the cluster head nodes and gateway nodes for both primary and secondary tiers. The DCHS mechanism satisfies an ideal distribution of the cluster head among the sensor nodes and avoids frequent selection of cluster head, based on Received Signal Strength Indication (RSSI and residual energy level of the sensor nodes. Since the RSSI is the key parameter for this paper, the practical experiment was conducted to measure RSSI value by using MSP430F149 processor and CC2500 transceiver. The measured RSSI values were given input to the event based simulator to test the DCHS mechanism. The real time experimental study validated the proposed scheme for various scenarios.

  2. Sensor fusion in head pose tracking for augmented reality

    NARCIS (Netherlands)

    Persa, S.F.

    2006-01-01

    The focus of this thesis is on studying diverse techniques, methods and sensors for position and orientation determination with application to augmented reality applications. In Chapter 2 we reviewed a variety of existing techniques and systems for position determination. From a practical point of

  3. Normalization of time-series satellite reflectance data to a standard sun-target-sensor geometry using a semi-empirical model

    Science.gov (United States)

    Zhao, Yongguang; Li, Chuanrong; Ma, Lingling; Tang, Lingli; Wang, Ning; Zhou, Chuncheng; Qian, Yonggang

    2017-10-01

    Time series of satellite reflectance data have been widely used to characterize environmental phenomena, describe trends in vegetation dynamics and study climate change. However, several sensors with wide spatial coverage and high observation frequency are usually designed to have large field of view (FOV), which cause variations in the sun-targetsensor geometry in time-series reflectance data. In this study, on the basis of semiempirical kernel-driven BRDF model, a new semi-empirical model was proposed to normalize the sun-target-sensor geometry of remote sensing image. To evaluate the proposed model, bidirectional reflectance under different canopy growth conditions simulated by Discrete Anisotropic Radiative Transfer (DART) model were used. The semi-empirical model was first fitted by using all simulated bidirectional reflectance. Experimental result showed a good fit between the bidirectional reflectance estimated by the proposed model and the simulated value. Then, MODIS time-series reflectance data was normalized to a common sun-target-sensor geometry by the proposed model. The experimental results showed the proposed model yielded good fits between the observed and estimated values. The noise-like fluctuations in time-series reflectance data was also reduced after the sun-target-sensor normalization process.

  4. Laboratory Evaluation of Low-Cost Wearable Sensors for Measuring Head Impacts in Sports.

    Science.gov (United States)

    Tyson, Abigail M; Duma, Stefan M; Rowson, Steven

    2018-04-03

    Advances in low-cost wearable head impact sensor technology provide potential benefits regarding sports safety for both consumers and researchers. However, previous laboratory evaluations are not directly comparable and don't incorporate test conditions representative of unhelmeted impacts. This study addresses those limitations. The xPatch by X2 Biosystems and the SIM-G by Triax Technologies were placed on a NOCSAE headform with a Hybrid III neck which underwent impacts tests using a pendulum. Impact conditions included helmeted, padded impactor to bare head, and rigid impactor to bare head to represent long and short-duration impacts seen in helmeted and unhelmeted sports. The wearable sensors were evaluated on their kinematic accuracy by comparing results to reference sensors located at the headform center of gravity. Statistical tests for equivalence were performed on the slope of the linear regression between wearable sensors and reference. The xPatch gave equivalent measurements to the reference in select longer-duration impacts whereas the SIM-G had large variance leading to no equivalence. For the short-duration impacts, both wearable sensors underpredicted the reference. This error can be improved with increases in sampling rate from 1 to 1.5 kHz. Follow-up evaluations should be performed on the field to identify error in vivo. (197/200).

  5. Cardiac and Respiratory Parameter Estimation Using Head-mounted Motion-sensitive Sensors

    Directory of Open Access Journals (Sweden)

    J. Hernandez

    2015-05-01

    Full Text Available This work explores the feasibility of using motion-sensitive sensors embedded in Google Glass, a head-mounted wearable device, to robustly measure physiological signals of the wearer. In particular, we develop new methods to use Glass’s accelerometer, gyroscope, and camera to extract pulse and respiratory waves of 12 participants during a controlled experiment. We show it is possible to achieve a mean absolute error of 0.82 beats per minute (STD: 1.98 for heart rate and 0.6 breaths per minute (STD: 1.19 for respiration rate when considering different observation windows and combinations of sensors. Moreover, we show that a head-mounted gyroscope sensor shows improved performance versus more commonly explored sensors such as accelerometers and demonstrate that a head-mounted camera is a novel and promising method to capture the physiological responses of the wearer. These findings included testing across sitting, supine, and standing postures before and after physical exercise.

  6. Energy Threshold-based Cluster Head Rotation for Routing Protocol in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Hadi Raheem Ali

    2018-05-01

    Full Text Available Energy efficiency represents a fundamental issue in WSNs, since the network lifetime period entirely depends on the energy of sensor nodes, which are usually battery-operated. In this article, an unequal clustering-based routing protocol has been suggested, where parameters of energy, distance, and density are involved in the cluster head election. Besides, the sizes of clusters are unequal according to distance, energy, and density. Furthermore, the cluster heads are not changed every round unless the residual energy reaches a specific threshold of energy. The outcomes of the conducted simulation confirmed that the performance of the suggested protocol achieves improvement in energy efficiency.

  7. Analytical network process based optimum cluster head selection in wireless sensor network.

    Science.gov (United States)

    Farman, Haleem; Javed, Huma; Jan, Bilal; Ahmad, Jamil; Ali, Shaukat; Khalil, Falak Naz; Khan, Murad

    2017-01-01

    Wireless Sensor Networks (WSNs) are becoming ubiquitous in everyday life due to their applications in weather forecasting, surveillance, implantable sensors for health monitoring and other plethora of applications. WSN is equipped with hundreds and thousands of small sensor nodes. As the size of a sensor node decreases, critical issues such as limited energy, computation time and limited memory become even more highlighted. In such a case, network lifetime mainly depends on efficient use of available resources. Organizing nearby nodes into clusters make it convenient to efficiently manage each cluster as well as the overall network. In this paper, we extend our previous work of grid-based hybrid network deployment approach, in which merge and split technique has been proposed to construct network topology. Constructing topology through our proposed technique, in this paper we have used analytical network process (ANP) model for cluster head selection in WSN. Five distinct parameters: distance from nodes (DistNode), residual energy level (REL), distance from centroid (DistCent), number of times the node has been selected as cluster head (TCH) and merged node (MN) are considered for CH selection. The problem of CH selection based on these parameters is tackled as a multi criteria decision system, for which ANP method is used for optimum cluster head selection. Main contribution of this work is to check the applicability of ANP model for cluster head selection in WSN. In addition, sensitivity analysis is carried out to check the stability of alternatives (available candidate nodes) and their ranking for different scenarios. The simulation results show that the proposed method outperforms existing energy efficient clustering protocols in terms of optimum CH selection and minimizing CH reselection process that results in extending overall network lifetime. This paper analyzes that ANP method used for CH selection with better understanding of the dependencies of

  8. Sun Allergy

    Science.gov (United States)

    Sun allergy Overview Sun allergy is a term often used to describe a number of conditions in which an itchy red rash occurs on skin that has been exposed to sunlight. The most common form of sun allergy is ...

  9. Muecas: A Multi-Sensor Robotic Head for Affective Human Robot Interaction and Imitation

    Directory of Open Access Journals (Sweden)

    Felipe Cid

    2014-04-01

    Full Text Available This paper presents a multi-sensor humanoid robotic head for human robot interaction. The design of the robotic head, Muecas, is based on ongoing research on the mechanisms of perception and imitation of human expressions and emotions. These mechanisms allow direct interaction between the robot and its human companion through the different natural language modalities: speech, body language and facial expressions. The robotic head has 12 degrees of freedom, in a human-like configuration, including eyes, eyebrows, mouth and neck, and has been designed and built entirely by IADeX (Engineering, Automation and Design of Extremadura and RoboLab. A detailed description of its kinematics is provided along with the design of the most complex controllers. Muecas can be directly controlled by FACS (Facial Action Coding System, the de facto standard for facial expression recognition and synthesis. This feature facilitates its use by third party platforms and encourages the development of imitation and of goal-based systems. Imitation systems learn from the user, while goal-based ones use planning techniques to drive the user towards a final desired state. To show the flexibility and reliability of the robotic head, the paper presents a software architecture that is able to detect, recognize, classify and generate facial expressions in real time using FACS. This system has been implemented using the robotics framework, RoboComp, which provides hardware-independent access to the sensors in the head. Finally, the paper presents experimental results showing the real-time functioning of the whole system, including recognition and imitation of human facial expressions.

  10. Naturalistic driving study of rear seat child occupants: Quantification of head position using a Kinect™ sensor.

    Science.gov (United States)

    Arbogast, Kristy B; Kim, Jinyong; Loeb, Helen; Kuo, Jonny; Koppel, Sjaan; Bohman, Katarina; Charlton, Judith L

    2016-09-01

    Restraint performance is evaluated using anthropomorphic test devices (ATDs) positioned in prescribed, optimal seating positions. Anecdotally, humans-children in particular-assume a variety of positions that may affect restraint performance. Naturalistic driving studies (NDSs), where cameras and other data acquisition systems are placed in a vehicle used by participants during their regular transportation, offer means to collect these data. To date, these studies have used conventional video and analysis methods and, thus, analyses have largely been qualitative. This article describes a recently completed NDS of child occupants in which their position was monitored using a Kinect sensor to quantify their head position throughout normal, everyday driving trips. A study vehicle was instrumented with a data acquisition system to measure vehicle dynamics, a set of video cameras, and a Kinect sensor providing 3D motion capture at 1 Hz of the rear seat occupants. Participant families used the vehicle for all driving trips over 2 weeks. The child occupants' head position was manually identified via custom software from each Kinect color image. The 3D head position was then extracted and its distribution summarized by seat position (left, rear, center) and restraint type (forward-facing child restraint system [FFCRS], booster seat, seat belt). Data from 18 families (37 child occupants) resulted in 582 trips (with children) for analysis. The average age of the child occupants was 45.6 months and 51% were male. Twenty-five child occupants were restrained in FFCRS, 9 in booster seats, and 3 in seat belts. As restraint type moved from more to less restraint (FFCRS to booster seat to seat belt), the range of fore-aft head position increased: 218, 244, and 340 mm on average, respectively. This observation was also true for left-right movement for every seat position. In general, those in the center seat position demonstrated a smaller range of head positions. For the first

  11. An Orientation Sensor-Based Head Tracking System for Driver Behaviour Monitoring

    Directory of Open Access Journals (Sweden)

    Yifan Zhao

    2017-11-01

    Full Text Available Although at present legislation does not allow drivers in a Level 3 autonomous vehicle to engage in a secondary task, there may become a time when it does. Monitoring the behaviour of drivers engaging in various non-driving activities (NDAs is crucial to decide how well the driver will be able to take over control of the vehicle. One limitation of the commonly used face-based head tracking system, using cameras, is that sufficient features of the face must be visible, which limits the detectable angle of head movement and thereby measurable NDAs, unless multiple cameras are used. This paper proposes a novel orientation sensor based head tracking system that includes twin devices, one of which measures the movement of the vehicle while the other measures the absolute movement of the head. Measurement error in the shaking and nodding axes were less than 0.4°, while error in the rolling axis was less than 2°. Comparison with a camera-based system, through in-house tests and on-road tests, showed that the main advantage of the proposed system is the ability to detect angles larger than 20° in the shaking and nodding axes. Finally, a case study demonstrated that the measurement of the shaking and nodding angles, produced from the proposed system, can effectively characterise the drivers’ behaviour while engaged in the NDAs of chatting to a passenger and playing on a smartphone.

  12. A Nonlinear Attitude Estimator for Attitude and Heading Reference Systems Based on MEMS Sensors

    DEFF Research Database (Denmark)

    Wang, Yunlong; Soltani, Mohsen; Hussain, Dil muhammed Akbar

    2016-01-01

    In this paper, a nonlinear attitude estimator is designed for an Attitude Heading and Reference System (AHRS) based on Micro Electro-Mechanical Systems (MEMS) sensors. The design process of the attitude estimator is stated with detail, and the equilibrium point of the estimator error model...... the problems in previous research works. Moreover, the estimation of MEMS gyroscope bias is also inclueded in this estimator. The designed nonlinear attitude estimator is firstly tested in simulation environment and then implemented in an AHRS hardware for further experiments. Finally, the attitude estimation...

  13. Markov Chain Model-Based Optimal Cluster Heads Selection for Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Gulnaz Ahmed

    2017-02-01

    Full Text Available The longer network lifetime of Wireless Sensor Networks (WSNs is a goal which is directly related to energy consumption. This energy consumption issue becomes more challenging when the energy load is not properly distributed in the sensing area. The hierarchal clustering architecture is the best choice for these kind of issues. In this paper, we introduce a novel clustering protocol called Markov chain model-based optimal cluster heads (MOCHs selection for WSNs. In our proposed model, we introduce a simple strategy for the optimal number of cluster heads selection to overcome the problem of uneven energy distribution in the network. The attractiveness of our model is that the BS controls the number of cluster heads while the cluster heads control the cluster members in each cluster in such a restricted manner that a uniform and even load is ensured in each cluster. We perform an extensive range of simulation using five quality measures, namely: the lifetime of the network, stable and unstable region in the lifetime of the network, throughput of the network, the number of cluster heads in the network, and the transmission time of the network to analyze the proposed model. We compare MOCHs against Sleep-awake Energy Efficient Distributed (SEED clustering, Artificial Bee Colony (ABC, Zone Based Routing (ZBR, and Centralized Energy Efficient Clustering (CEEC using the above-discussed quality metrics and found that the lifetime of the proposed model is almost 1095, 2630, 3599, and 2045 rounds (time steps greater than SEED, ABC, ZBR, and CEEC, respectively. The obtained results demonstrate that the MOCHs is better than SEED, ABC, ZBR, and CEEC in terms of energy efficiency and the network throughput.

  14. Fabrication of robot head module using contact resistance force sensor for human robot interaction and its evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dong Ki; Kim, Jong Ho [Korea Reserch Institute of Standards and Science, Daejeon (Korea, Republic of); Kwon, Hyun Joon [Univ. of Maryland, Maryland (United States); Kwon, Young Ha [Kyung Hee Univ., Gyunggi Do (Korea, Republic of)

    2012-10-15

    This paper presents a design of a robot head module with touch sensing algorithms that can simultaneously detect contact force and location. The module is constructed with a hemisphere and three sensor units that are fabricated using contact resistance force sensors. The surface part is designed with the hemisphere that measures 300 mm in diameter and 150 mm in height. Placed at the bottom of the robot head module are three sensor units fabricated using a simple screen printing technique. The contact force and the location of the model are evaluated through the calibration setup. The experiment showed that the calculated contact positions almost coincided with the applied load points as the contact location changed with a location error of about {+-}8.67 mm. The force responses of the module were evaluated at two points under loading and unloading conditions from 0 N to 5 N. The robot head module showed almost the same force responses at the two points.

  15. Sun protection

    Science.gov (United States)

    ... sun exposure. The start of summer is when UV rays can cause the most skin damage. Use sun protection, even on cloudy days. Clouds and haze don't protect you from the sun. Avoid surfaces that reflect light, such as water, sand, concrete, snow, and areas ...

  16. SIMBIOS Normalized Water-Leaving Radiance Calibration and Validation: Sensor Response, Atmospheric Corrections, Stray Light and Sun Glint. Chapter 14

    Science.gov (United States)

    Mueller, James L.

    2001-01-01

    This Sensor Intercomparison and Merger for Biological and Interdisciplinary Oceanic Studies (SIMBIOS) contract supports acquisition of match up radiometric and bio-optical data for validation of Sea-Viewing Wide Field-of-view Sensor (SeaWiFS) and other ocean color satellites, and evaluation of uncertainty budgets and protocols for in situ measurements of normalized water leaving radiances.

  17. Integrated pressure sensor systems in the cylinder-head gasket; Integrierte Drucksensorik in der Zylinderkopfdichtung

    Energy Technology Data Exchange (ETDEWEB)

    Diez, A.; Maier, U. [ElringKlinger AG (Germany); Eifler, G. [ElringKlinger Motortechnik GmbH (Germany); Schnepf, M. [Kistler Instrumente AG, Winterthur (Switzerland)

    2004-01-01

    The optimisation of engine management plays a major role in the development of modern engines. A significant contribution to this optimisation will be made by a cylinder-head gasket with integrated pressure sensors of the quality required to measure in-cylinder pressure, which ElringKlinger AG together with Kistler Instrumente AG are currently working on. The goal is to provide the automotive industry with a system that makes it possible to optimally control combustion in each individual cylinder. (orig.) [German] Die Optimierung des Motormanagements spielt bei der Entwicklung moderner Motoren eine zentrale Rolle. Eine Zylinderkopfdichtung mit integrierten Druckaufnehmern in Indizierqualitaet, an der die Elring-Klinger AG und die Kistler Instrumente AG derzeit gemeinsam arbeiten, soll hierzu einen entscheidenden Beitrag leisten. Ziel ist es, der Automobilindustrie ein System zur Verfuegung zu stellen, das eine optimierte und zylinderindividuelle Steuerung der Verbrennung ermoeglicht. (orig.)

  18. Development of an Optical Sensor Head for Current and Temperature Measurements in Power Systems

    Directory of Open Access Journals (Sweden)

    Fábio V. B. de Nazaré

    2013-01-01

    Full Text Available The development of a current and temperature monitoring optical device intended to be used in high-voltage environments, particularly transmission lines, is presented. The system is intended to offer not only measurement reliability, but to be also practical and light weighted. Fiber Bragg gratings (FBGs are employed in the measurement of both physical parameters: the current will be acquired using a hybrid sensor head setup—an FBG fixed on a magnetostrictive rod—while a single-point temperature information is provided by a dedicated grating. An inexpensive and outdoor-suitable demodulation method, such as the fixed filter technique, should be used in order to improve the instrumentation robustness, avoiding expensive and complex auxiliary electronics. The preliminary results for laboratory tests are also discussed.

  19. Fast in-situ tool inspection based on inverse fringe projection and compact sensor heads

    Science.gov (United States)

    Matthias, Steffen; Kästner, Markus; Reithmeier, Eduard

    2016-11-01

    Inspection of machine elements is an important task in production processes in order to ensure the quality of produced parts and to gather feedback for the continuous improvement process. A new measuring system is presented, which is capable of performing the inspection of critical tool geometries, such as gearing elements, inside the forming machine. To meet the constraints on sensor head size and inspection time imposed by the limited space inside the machine and the cycle time of the process, the measuring device employs a combination of endoscopy techniques with the fringe projection principle. Compact gradient index lenses enable a compact design of the sensor head, which is connected to a CMOS camera and a flexible micro-mirror based projector via flexible fiber bundles. Using common fringe projection patterns, the system achieves measuring times of less than five seconds. To further reduce the time required for inspection, the generation of inverse fringe projection patterns has been implemented for the system. Inverse fringe projection speeds up the inspection process by employing object-adapted patterns, which enable the detection of geometry deviations in a single image. Two different approaches to generate object adapted patterns are presented. The first approach uses a reference measurement of a manufactured tool master to generate the inverse pattern. The second approach is based on a virtual master geometry in the form of a CAD file and a ray-tracing model of the measuring system. Virtual modeling of the measuring device and inspection setup allows for geometric tolerancing for free-form surfaces by the tool designer in the CAD-file. A new approach is presented, which uses virtual tolerance specifications and additional simulation steps to enable fast checking of metric tolerances. Following the description of the pattern generation process, the image processing steps required for inspection are demonstrated on captures of gearing geometries.

  20. Cluster Head Selection in a Homogeneous Wireless Sensor Network Ensuring Full Connectivity with Minimum Isolated Nodes

    Directory of Open Access Journals (Sweden)

    Tapan Kumar Jain

    2014-01-01

    Full Text Available The research work proposes a cluster head selection algorithm for a wireless sensor network. A node can be a cluster head if it is connected to at least one unique neighbor node where the unique neighbor is the one that is not connected to any other node. If there is no connected unique node then the CH is selected on the basis of residual energy and the number of neighbor nodes. With the increase in number of clusters, the processing energy of the network increases; hence, this algorithm proposes minimum number of clusters which further leads to increased network lifetime. The major novel contribution of the proposed work is an algorithm that ensures a completely connected network with minimum number of isolated nodes. An isolated node will remain only if it is not within the transmission range of any other node. With the maximum connectivity, the coverage of the network is automatically maximized. The superiority of the proposed design is verified by simulation results done in MATLAB, where it clearly depicts that the total numbers of rounds before the network dies out are maximum compared to other existing protocols.

  1. Intracerebral hemorrhage (ICH) evaluation with a novel magnetic induction sensor: a preliminary study using the Chinese head model.

    Science.gov (United States)

    Zhang, Ziyi; Liu, Peiguo; Zhou, Dongming; Zhang, Liang; Lei, Hengdong

    2014-01-01

    Biomedical magnetic induction measurement is a promising method for the detection of intracerebral hemorrhage (ICH), especially in China. Aiming at overcoming the problem of low sensitivity, a magnetic induction sensor is chosen to replace the conventional sensors. It uses a two-arm Archimedean spiral coil as the exciter and a circular coil as the receiver. In order to carry out high-fidelity simulations, the Chinese head model with real anatomical structure is introduced into this novel sensor for the first time. Simulations have been carried out upon early stage ICH measurements. By calculating the state sensitivity and time sensitivity of the perturbation phase of two types of sensors using the electromagnetic software, we conclude that the primary signal received can be largely reduced using the novel sensor, which could effectively increase the time and state sensitivity simultaneously.

  2. Design and implementation of a Sun tracker with a dual-axis single motor for an optical sensor-based photovoltaic system.

    Science.gov (United States)

    Wang, Jing-Min; Lu, Chia-Liang

    2013-03-06

    The dual threats of energy depletion and global warming place the development of methods for harnessing renewable energy resources at the center of public interest. Solar energy is one of the most promising renewable energy resources. Sun trackers can substantially improve the electricity production of a photovoltaic (PV) system. This paper proposes a novel design of a dual-axis solar tracking PV system which utilizes the feedback control theory along with a four-quadrant light dependent resistor (LDR) sensor and simple electronic circuits to provide robust system performance. The proposed system uses a unique dual-axis AC motor and a stand-alone PV inverter to accomplish solar tracking. The control implementation is a technical innovation that is a simple and effective design. In addition, a scaled-down laboratory prototype is constructed to verify the feasibility of the scheme. The effectiveness of the Sun tracker is confirmed experimentally. To conclude, the results of this study may serve as valuable references for future solar energy applications.

  3. Design and Implementation of a Sun Tracker with a Dual-Axis Single Motor for an Optical Sensor-Based Photovoltaic System

    Directory of Open Access Journals (Sweden)

    Chia-Liang Lu

    2013-03-01

    Full Text Available The dual threats of energy depletion and global warming place the development of methods for harnessing renewable energy resources at the center of public interest. Solar energy is one of the most promising renewable energy resources. Sun trackers can substantially improve the electricity production of a photovoltaic (PV system. This paper proposes a novel design of a dual-axis solar tracking PV system which utilizes the feedback control theory along with a four-quadrant light dependent resistor (LDR sensor and simple electronic circuits to provide robust system performance. The proposed system uses a unique dual-axis AC motor and a stand-alone PV inverter to accomplish solar tracking. The control implementation is a technical innovation that is a simple and effective design. In addition, a scaled-down laboratory prototype is constructed to verify the feasibility of the scheme. The effectiveness of the Sun tracker is confirmed experimentally. To conclude, the results of this study may serve as valuable references for future solar energy applications.

  4. Design and Implementation of a Sun Tracker with a Dual-Axis Single Motor for an Optical Sensor-Based Photovoltaic System

    Science.gov (United States)

    Wang, Jing-Min; Lu, Chia-Liang

    2013-01-01

    The dual threats of energy depletion and global warming place the development of methods for harnessing renewable energy resources at the center of public interest. Solar energy is one of the most promising renewable energy resources. Sun trackers can substantially improve the electricity production of a photovoltaic (PV) system. This paper proposes a novel design of a dual-axis solar tracking PV system which utilizes the feedback control theory along with a four-quadrant light dependent resistor (LDR) sensor and simple electronic circuits to provide robust system performance. The proposed system uses a unique dual-axis AC motor and a stand-alone PV inverter to accomplish solar tracking. The control implementation is a technical innovation that is a simple and effective design. In addition, a scaled-down laboratory prototype is constructed to verify the feasibility of the scheme. The effectiveness of the Sun tracker is confirmed experimentally. To conclude, the results of this study may serve as valuable references for future solar energy applications. PMID:23467030

  5. Sun and solar flares

    Energy Technology Data Exchange (ETDEWEB)

    McKenna-Lawlor, S. (Saint Patrick' s Coll., Maynooth (Ireland))

    1982-07-01

    The subject is discussed under the headings: the sun's core (thermonuclear reactions, energy transfer from core through radiation zone, convection zone, photosphere, chromosphere and corona); the photosphere (convection, granulation, sunspots, magnetic fields, solar cycle, rotation of the sun); solar variability and paleoclimatic records (correlation of low solar activity with increased /sup 14/C production in atmosphere); the chromosphere and corona (turbulence, temperature, coronal streamers, energy transfer); solar flares (cosmic rays, aurorae, spectra, velocity of flares, prominences, mechanisms of flares); the solar wind.

  6. How Magnetic Disturbance Influences the Attitude and Heading in Magnetic and Inertial Sensor-Based Orientation Estimation.

    Science.gov (United States)

    Fan, Bingfei; Li, Qingguo; Liu, Tao

    2017-12-28

    With the advancements in micro-electromechanical systems (MEMS) technologies, magnetic and inertial sensors are becoming more and more accurate, lightweight, smaller in size as well as low-cost, which in turn boosts their applications in human movement analysis. However, challenges still exist in the field of sensor orientation estimation, where magnetic disturbance represents one of the obstacles limiting their practical application. The objective of this paper is to systematically analyze exactly how magnetic disturbances affects the attitude and heading estimation for a magnetic and inertial sensor. First, we reviewed four major components dealing with magnetic disturbance, namely decoupling attitude estimation from magnetic reading, gyro bias estimation, adaptive strategies of compensating magnetic disturbance and sensor fusion algorithms. We review and analyze the features of existing methods of each component. Second, to understand each component in magnetic disturbance rejection, four representative sensor fusion methods were implemented, including gradient descent algorithms, improved explicit complementary filter, dual-linear Kalman filter and extended Kalman filter. Finally, a new standardized testing procedure has been developed to objectively assess the performance of each method against magnetic disturbance. Based upon the testing results, the strength and weakness of the existing sensor fusion methods were easily examined, and suggestions were presented for selecting a proper sensor fusion algorithm or developing new sensor fusion method.

  7. Sun Safety

    Science.gov (United States)

    ... Children from the Sun? Are There Benefits to Spending Time Outdoors? The Surgeon General’s Call to Action to Prevent Skin Cancer Related Resources Sun Safety Tips for Men Tips for Families Tips for Schools Tips for Employers Tips for ...

  8. baonan sun

    Indian Academy of Sciences (India)

    Home; Journals; Pramana – Journal of Physics. BAONAN SUN. Articles written in Pramana – Journal of Physics. Volume 90 Issue 2 February 2018 pp 23 Research Article. Rogue waves in the multicomponent Mel'nikov system and multicomponent Schrödinger–Boussinesq system · BAONAN SUN ZHAN LIAN.

  9. Fengrui Sun

    Indian Academy of Sciences (India)

    Home; Journals; Sadhana. Fengrui Sun. Articles written in Sadhana. Volume 34 Issue 5 October 2009 pp 851-864. Profit rate performance optimization for a generalized irreversible combined refrigeration cycle · Kang Ma Lingen Chen Fengrui Sun · More Details Abstract Fulltext PDF. Finite-time exergoeconomic ...

  10. 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.

  11. 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 ...

  12. 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...

  13. Head impacts in a junior rugby league team measured with a wireless head impact sensor: an exploratory analysis.

    Science.gov (United States)

    King, Doug; Hume, Patria; Gissane, Conor; Clark, Trevor

    2017-01-01

    OBJECTIVE The aim of this study was to investigate the frequency, magnitude, and distribution of head impacts sustained by players in a junior rugby league over a season of matches. METHODS The authors performed a prospective cohort analysis of impact magnitude, frequency, and distribution on data collected with instrumented XPatches worn behind the ear of players in an "under-11" junior rugby league team (players under 11 years old). RESULTS A total of 1977 impacts were recorded. Over the course of the study, players sustained an average of 116 impacts (average of 13 impacts per player per match). The measured linear acceleration ranged from 10g to 123g (mean 22g, median 16g, and 95th percentile 57g). The rotational acceleration ranged from 89 rad/sec 2 to 22,928 rad/sec 2 (mean 4041 rad/sec 2 , median 2773 rad/sec 2 , and 95th percentile 11,384 rad/sec 2 ). CONCLUSIONS The level of impact severity based on the magnitude of impacts for linear and rotational accelerations recorded was similar to the impacts reported in studies of American junior and high school football, collegiate football, and youth ice hockey players, but the players in the rugby league cohort were younger, had less body mass, and played at a slower speed than the American players. Junior rugby league players are required to tackle the player to the ground and use a different tackle technique than that used in American football, likely increasing the rotational accelerations recorded at the head.

  14. As reliable as the sun

    Science.gov (United States)

    Leijtens, J. A. P.

    2017-11-01

    Fortunately there is almost nothing as reliable as the sun which can consequently be utilized as a very reliable source of spacecraft power. In order to harvest this power, the solar panels have to be pointed towards the sun as accurately and reliably as possible. To this extend, sunsensors are available on almost every satellite to support vital sun-pointing capability throughout the mission, even in the deployment and save mode phases of the satellites life. Given the criticality of the application one would expect that after more than 50 years of sun sensor utilisation, such sensors would be fully matured and optimised. In actual fact though, the majority of sunsensors employed are still coarse sunsensors which have a proven extreme reliability but present major issues regarding albedo sensitivity and pointing accuracy.

  15. 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.

  16. yimin sun

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Genetics. YIMIN SUN. Articles written in Journal of Genetics. Volume 96 Issue 4 September 2017 pp 687-693 RESEARCH NOTE. The association study of nonsyndromic cleft lip with or without cleft palate identified risk variants of the GLI3 gene in a Chinese population · YIRUI WANG YIMIN SUN ...

  17. jianhua sun

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Biosciences. JIANHUA SUN. Articles written in Journal of Biosciences. Volume 42 Issue 4 December 2017 pp 575-584 Article. MicroRNA-486-5p suppresses TGF-b2-induced proliferation, invasion and epithelial–mesenchymal transition of lens epithelial cells by targeting Smad2.

  18. Energy generation for an ad hoc wireless sensor network-based monitoring system using animal head movement

    DEFF Research Database (Denmark)

    S. Nadimi, Esmaeil; Blanes-Vidal, Victoria; Jørgensen, Rasmus Nyholm

    2011-01-01

    are not easily accessible. Therefore, exploring novel sources of energy generation rather than operating electronics only on limited power supplies such as batteries is a major challenge. Monitoring free-ranging animal behavior is an application in which the entities (animals) within the MANET are not readily...... that the amount of energy generated by the vertical neck–head movement of sheep during grazing can be converted to useful electrical power adequate to provide power for operation of wireless sensor nodes on a continuous basis within a MANET-based animal behavior monitoring system.......The supply of energy to electronics is an imperative constraining factor to be considered during the design process of mobile ad hoc wireless sensor networks (MANETs). This influence is especially important when the MANET is deployed unattended or the wireless modules within the MANET...

  19. Direct measurement of the field from a magnetic recording head using an InAs Hall sensor on a contact write/read tester

    International Nuclear Information System (INIS)

    Gokemeijer, N.J.; Clinton, T.W.; Crawford, T.M.; Johnson, Mark

    2005-01-01

    At 1 Tbit/in 2 areal density magnetic recording dimensions, reliable magnetic field metrology does not exist. One technique to map the spatial profile of the magnetic field of a write head is to use a contact read/write tester. A magnetic recording head is brought into contact with a Hall sensor, and is subsequently scanned with nm resolution. For a 300 nm track width longitudinal recording head, the magnetic field of the head was mapped. Measurements include the down track field gradient and cross-track field profile and the current-field transfer curve. These results suggest this technique offers a viable write field metrology

  20. FRCA: A Fuzzy Relevance-Based Cluster Head Selection Algorithm for Wireless Mobile Ad-Hoc Sensor Networks

    Directory of Open Access Journals (Sweden)

    Taegwon Jeong

    2011-05-01

    Full Text Available Clustering is an important mechanism that efficiently provides information for mobile nodes and improves the processing capacity of routing, bandwidth allocation, and resource management and sharing. Clustering algorithms can be based on such criteria as the battery power of nodes, mobility, network size, distance, speed and direction. Above all, in order to achieve good clustering performance, overhead should be minimized, allowing mobile nodes to join and leave without perturbing the membership of the cluster while preserving current cluster structure as much as possible. This paper proposes a Fuzzy Relevance-based Cluster head selection Algorithm (FRCA to solve problems found in existing wireless mobile ad hoc sensor networks, such as the node distribution found in dynamic properties due to mobility and flat structures and disturbance of the cluster formation. The proposed mechanism uses fuzzy relevance to select the cluster head for clustering in wireless mobile ad hoc sensor networks. In the simulation implemented on the NS-2 simulator, the proposed FRCA is compared with algorithms such as the Cluster-based Routing Protocol (CBRP, the Weighted-based Adaptive Clustering Algorithm (WACA, and the Scenario-based Clustering Algorithm for Mobile ad hoc networks (SCAM. The simulation results showed that the proposed FRCA achieves better performance than that of the other existing mechanisms.

  1. FRCA: a fuzzy relevance-based cluster head selection algorithm for wireless mobile ad-hoc sensor networks.

    Science.gov (United States)

    Lee, Chongdeuk; Jeong, Taegwon

    2011-01-01

    Clustering is an important mechanism that efficiently provides information for mobile nodes and improves the processing capacity of routing, bandwidth allocation, and resource management and sharing. Clustering algorithms can be based on such criteria as the battery power of nodes, mobility, network size, distance, speed and direction. Above all, in order to achieve good clustering performance, overhead should be minimized, allowing mobile nodes to join and leave without perturbing the membership of the cluster while preserving current cluster structure as much as possible. This paper proposes a Fuzzy Relevance-based Cluster head selection Algorithm (FRCA) to solve problems found in existing wireless mobile ad hoc sensor networks, such as the node distribution found in dynamic properties due to mobility and flat structures and disturbance of the cluster formation. The proposed mechanism uses fuzzy relevance to select the cluster head for clustering in wireless mobile ad hoc sensor networks. In the simulation implemented on the NS-2 simulator, the proposed FRCA is compared with algorithms such as the Cluster-based Routing Protocol (CBRP), the Weighted-based Adaptive Clustering Algorithm (WACA), and the Scenario-based Clustering Algorithm for Mobile ad hoc networks (SCAM). The simulation results showed that the proposed FRCA achieves better performance than that of the other existing mechanisms.

  2. Fiber interferometer combining sub-nm displacement resolution with miniaturized sensor head

    NARCIS (Netherlands)

    Cheng, L.K.; Hagen, R.A.J.; Schriek, L.N.; Toet, P.M.; Togt, O.E. van der

    2017-01-01

    The presented interferometer concept enables high-accuracy target displacement measurement in difficult accessible locations and the development of small fiber optic sensor to measure other physical parameters e.g. pressure, vibration, gravity force, etc.. Furthermore, this configuration is

  3. The Sun

    International Nuclear Information System (INIS)

    Hejna, L.; Sobotka, M.

    1987-01-01

    The conference proceedings contain 50 papers classified in six parts. The introductory paper is devoted to magnetic fields of the Sun and of low-mass main-sequence stars. 7 papers discuss the morphology and fine structure of solar active regions, 9 papers deal with evolutionary aspects of the regions, 6 papers with observations and theories of the solar magnetic field, 9 deal with velocity fields, oscillations and waves in the active regions and 18 papers discuss the physical structure of active regions and its diagnostics. (M.D.). 218 figs., 19 tabs., 1,317 refs

  4. Cheap two axis sun following device

    International Nuclear Information System (INIS)

    Roth, P.; Georgiev, A.; Boudinov, H.

    2005-01-01

    A sun following system was constructed and tested. The tracker gives the possibility for automatic measuring of direct solar radiation with a phetylureum. The mechanism is operated by a digital program in the control system, situated separately from the mechanical part. The position of the sun is calculated, and the pointing errors appearing during its daily work are stored for later analysis. Additionally, in the active operation mode, the tracker uses the signal of a sun detecting linear sensor to control the pointing. Two stepper motors move the instrument platform, keeping the sun's beam at the center of the sensor. The mechanism was created at the Laboratory 'Evaluation Solar' of the Technical University Faradaic Santa Maria (UTFSM) in Valparaiso, Chile. The experiments show good results. The described sun tracker gives similar results as the Swiss sun tracker INTRA at a very much lower price

  5. Sun behaviour in Canadian children: results of the 2006 National Sun Survey.

    Science.gov (United States)

    Pichora, Erin C; Marrett, Loraine D

    2010-01-01

    Childhood sun exposure is a particularly important determinant of skin cancer, yet little data are available for children. This paper describes sun behaviour among Canadian children for the summer of 2006. As part of the Second National Sun Survey (NSS2), 1,437 parents reported on the time spent in the sun, and the frequency of sun protection behaviours and sunburning for one of their children aged 1 to 12 years. Analysis was carried out using complex survey procedures in SAS and STATA. The majority of children (94%) spend at least 30 minutes in the sun on a typical summer day; however, regular sun protection is only commonly reported for young children (1 to 5 years) and involves covering their heads and wearing sunscreen (85%). The frequency of other protective behaviours is much lower, and sun protection decreases with age. Older children are also twice as likely to spend extended time in the sun and to get a sunburn. Among older children, boys are more likely to cover their heads and girls are more likely to wear sunscreen. Regular sun protection among Canadian children is low, given their sun exposure. Heavy reliance on sunscreen is consistent with previous reports and indicates that other measures, such as seeking shade and wearing protective clothing, need to be promoted. Riskier sun behaviour among older children may reflect decreased parental control, as well as changing attitudes and peer pressure, and highlights the importance of adult role models and targeted interventions for this age group.

  6. Comparison of Water Vapor Measurements by Airborne Sun Photometer and Near-Coincident in Situ and Satellite Sensors during INTEX/ITCT 2004

    Science.gov (United States)

    Livingston, J.; Schmid, B.; Redemann, J.; Russell, P. B.; Ramirez, S. A.; Eilers, J.; Gore, W.; Howard, S.; Pommier, J.; Fetzer, E. J.; hide

    2007-01-01

    We have retrieved columnar water vapor (CWV) from measurements acquired by the 14-channel NASA Ames Airborne Tracking Sun photometer (AATS-14) during 19 Jetstream 31 (J31) flights over the Gulf of Maine in summer 2004 in support of the Intercontinental Chemical Transport Experiment (INTEX)/Intercontinental Transport and Chemical Transformation (ITCT) experiments. In this paper we compare AATS-14 water vapor retrievals during aircraft vertical profiles with measurements by an onboard Vaisala HMP243 humidity sensor and by ship radiosondes and with water vapor profiles retrieved from AIRS measurements during eight Aqua overpasses. We also compare AATS CWV and MODIS infrared CWV retrievals during five Aqua and five Terra overpasses. For 35 J31 vertical profiles, mean (bias) and RMS AATS-minus-Vaisala layer-integrated water vapor (LWV) differences are -7.1 percent and 8.8 percent, respectively. For 22 aircraft profiles within 1 hour and 130 km of radiosonde soundings, AATS-minus-sonde bias and RMS LWV differences are -5.4 percent and 10.7 percent, respectively, and corresponding J31 Vaisala-minus-sonde differences are 2.3 percent and 8.4 percent, respectively. AIRS LWV retrievals within 80 lan of J31 profiles yield lower bias and RMS differences compared to AATS or Vaisala retrievals than do AIRS retrievals within 150 km of the J31. In particular, for AIRS-minus-AATS LWV differences, the bias decreases from 8.8 percent to 5.8 percent, and the RMS difference decreases from 2 1.5 percent to 16.4 percent. Comparison of vertically resolved AIRS water vapor retrievals (LWVA) to AATS values in fixed pressure layers yields biases of -2 percent to +6 percent and RMS differences of -20 percent below 700 hPa. Variability and magnitude of these differences increase significantly above 700 hPa. MODIS IR retrievals of CWV in 205 grid cells (5 x 5 km at nadir) are biased wet by 10.4 percent compared to AATS over-ocean near-surface retrievals. The MODIS-Aqua subset (79 grid cells

  7. DCE: A Distributed Energy-Efficient Clustering Protocol for Wireless Sensor Network Based on Double-Phase Cluster-Head Election.

    Science.gov (United States)

    Han, Ruisong; Yang, Wei; Wang, Yipeng; You, Kaiming

    2017-05-01

    Clustering is an effective technique used to reduce energy consumption and extend the lifetime of wireless sensor network (WSN). The characteristic of energy heterogeneity of WSNs should be considered when designing clustering protocols. We propose and evaluate a novel distributed energy-efficient clustering protocol called DCE for heterogeneous wireless sensor networks, based on a Double-phase Cluster-head Election scheme. In DCE, the procedure of cluster head election is divided into two phases. In the first phase, tentative cluster heads are elected with the probabilities which are decided by the relative levels of initial and residual energy. Then, in the second phase, the tentative cluster heads are replaced by their cluster members to form the final set of cluster heads if any member in their cluster has more residual energy. Employing two phases for cluster-head election ensures that the nodes with more energy have a higher chance to be cluster heads. Energy consumption is well-distributed in the proposed protocol, and the simulation results show that DCE achieves longer stability periods than other typical clustering protocols in heterogeneous scenarios.

  8. The sun and solar flares

    International Nuclear Information System (INIS)

    McKenna-Lawlor, S.

    1982-01-01

    The subject is discussed under the headings: the sun's core (thermonuclear reactions, energy transfer from core through radiation zone, convection zone, photosphere, chromosphere and corona); the photosphere (convection, granulation, sunspots, magnetic fields, solar cycle, rotation of the sun); solar variability and paleoclimatic records (correlation of low solar activity with increased 14 C production in atmosphere); the chromosphere and corona (turbulence, temperature, coronal streamers, energy transfer); solar flares (cosmic rays, aurorae, spectra, velocity of flares, prominences, mechanisms of flares); the solar wind. (U.K.)

  9. Hand-held Raman sensor head for in-situ characterization of meat quality applying a microsystem 671 nm diode laser

    Science.gov (United States)

    Schmidt, Heinar; Sowoidnich, Kay; Maiwald, Martin; Sumpf, Bernd; Kronfeldt, Heinz-Detlef

    2009-05-01

    A hand-held Raman sensor head was developed for the in-situ characterization of meat quality. As light source, a microsystem based external cavity diode laser module (ECDL) emitting at 671 nm was integrated in the sensor head and attached to a miniaturized optical bench which contains lens optics for excitation and signal collection as well as a Raman filter stage for Rayleigh rejection. The signal is transported with an optical fiber to the detection unit which was in the initial phase a laboratory spectrometer with CCD detector. All elements of the ECDL are aligned on a micro optical bench with 13 x 4 mm2 footprint. The wavelength stability is provided by a reflection Bragg grating and the laser has an optical power of up to 200 mW. However, for the Raman measurements of meat only 35 mW are needed to obtain Raman spectra within 1 - 5 seconds. Short measuring times are essential for the hand-held device. The laser and the sensor head are characterized in terms of stability and performance for in-situ Raman investigations. The function is demonstrated in a series of measurements with raw and packaged pork meat as samples. The suitability of the Raman sensor head for the quality control of meat and other products will be discussed.

  10. Sensors

    CERN Document Server

    Pigorsch, Enrico

    1997-01-01

    This is the 5th edition of the Metra Martech Directory "EUROPEAN CENTRES OF EXPERTISE - SENSORS." The entries represent a survey of European sensors development. The new edition contains 425 detailed profiles of companies and research institutions in 22 countries. This is reflected in the diversity of sensors development programmes described, from sensors for physical parameters to biosensors and intelligent sensor systems. We do not claim that all European organisations developing sensors are included, but this is a good cross section from an invited list of participants. If you see gaps or omissions, or would like your organisation to be included, please send details. The data base invites the formation of effective joint ventures by identifying and providing access to specific areas in which organisations offer collaboration. This issue is recognised to be of great importance and most entrants include details of collaboration offered and sought. We hope the directory on Sensors will help you to find the ri...

  11. Sensors

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, H. [PBI-Dansensor A/S (Denmark); Toft Soerensen, O. [Risoe National Lab., Materials Research Dept. (Denmark)

    1999-10-01

    A new type of ceramic oxygen sensors based on semiconducting oxides was developed in this project. The advantage of these sensors compared to standard ZrO{sub 2} sensors is that they do not require a reference gas and that they can be produced in small sizes. The sensor design and the techniques developed for production of these sensors are judged suitable by the participating industry for a niche production of a new generation of oxygen sensors. Materials research on new oxygen ion conducting conductors both for applications in oxygen sensors and in fuel was also performed in this project and finally a new process was developed for fabrication of ceramic tubes by dip-coating. (EHS)

  12. 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.

  13. Work-time sun behaviours among Canadian outdoor workers: results from the 2006 National Sun Survey.

    Science.gov (United States)

    Marrett, Loraine D; Pichora, Erin C; Costa, Michelle L

    2010-01-01

    The objective of the study was to describe summer work-related sun behaviours among Canadian outdoor workers. Information on time in the sun and sun protection practices at work during the summer of 2006 were collected from 1,337 outdoor workers aged 16-64 years as part of the Second National Sun Survey. Proportions (and 95% confidence intervals) were estimated using procedures appropriate for complex survey designs. Twenty-six percent of all Canadians, 39% of males and 33% of those aged 16-24 years work outdoors during the summer. Although 41% spend four or more hours daily in the sun at work, just over half always or often protect themselves by covering their heads (58%), wearing protective clothing (56%) or wearing sunglasses (54%), and only 29% use sunscreen. Males and those aged 16-24 spend the most work time in the sun but are the least likely to use protection. The prevalence of outdoor work and sun behaviours varies among regions. Study findings confirm the need for strategies to reduce time in the sun and increase the use of sun protection among outdoor workers. In order to be effective, these strategies must include both enhanced workplace policies and practice, and increased individual use of sun protection.

  14. 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.

  15. 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...

  16. Identifying early dehydration risk with home-based sensors during radiation treatment: a feasibility study on patients with head and neck cancer.

    Science.gov (United States)

    Peterson, Susan K; Shinn, Eileen H; Basen-Engquist, Karen; Demark-Wahnefried, Wendy; Prokhorov, Alexander V; Baru, Chaitanya; Krueger, Ingolf H; Farcas, Emilia; Rios, Philip; Garden, Adam S; Beadle, Beth M; Lin, Kai; Yan, Yan; Martch, Stephanie L; Patrick, Kevin

    2013-12-01

    Systems that enable remote monitoring of patients' symptoms and other health-related outcomes may optimize cancer care outside of the clinic setting. CYCORE (CYberinfrastructure for COmparative effectiveness REsearch) is a software-based prototype for a user-friendly cyberinfrastructure supporting the comprehensive collection and analyses of data from multiple domains using a suite of home-based and mobile sensors. This study evaluated the feasibility of using CYCORE to address early at-home identification of dehydration risk in head and neck cancer patients undergoing radiation therapy. Head and neck cancer patients used home-based sensors to capture weight, blood pressure, pulse, and patient-reported outcomes for two 5-day periods during radiation therapy. Data were sent to the radiation oncologist of each head and neck cancer patient, who viewed them online via a Web-based interface. Feasibility outcomes included study completion rate, acceptability and perceived usefulness of the intervention, and adherence to the monitoring protocol. We also evaluated whether sensor data could identify dehydration-related events. Fifty patients consented to participate, and 48 (96%) completed the study. More than 90% of patients rated their ease, self-efficacy, and satisfaction regarding use of the sensor suite as extremely favorable, with minimal concerns expressed regarding data privacy issues. Patients highly valued the ability to have immediate access to objective, self-monitoring data related to personal risk for dehydration. Clinician assessments indicated a high degree of satisfaction with the ease of using the CYCORE system and the resulting ability to monitor their patients remotely. Implementing CYCORE in a clinical oncology care setting is feasible and highly acceptable to both patients and providers.

  17. 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…

  18. The star ''Sun''

    International Nuclear Information System (INIS)

    Pecker, J.-C.

    1982-01-01

    The author gives a resume of our knowledge of the Sun. In particular, he discusses the mass, luminosity and chemical composition of the Sun, and then asks what an observer from Sirius would think about the Sun. (G.T.H.)

  19. SAR and thermal response effects of a two-arm Archimedean spiral coil in a magnetic induction sensor on a human head.

    Science.gov (United States)

    Zhang, Ziyi; Liu, Peiguo; Zhou, Dongming; Zhang, Liang; Ding, Liang

    2015-01-01

    This study investigates the radiation safety of a newly designed magnetic induction sensor. This novel magnetic induction sensor uses a two-arm Archimedean spiral coil (TAASC) as the exciter. A human head model with a real anatomical structure was used to calculate the specific absorption rate (SAR) and temperature change. Computer Simulation Technology (CST) was used to determine the values of the peak 10-g SAR under different operating parameters (current, frequency, horizontal distance between the excitation coil and the receiver coil, vertical distance between the top of the head model and the XOY plane, position of excitation coil, and volume of hemorrhage). Then, the highest response for the SAR and temperature rise was determined. The results showed that this new magnetic induction sensor is safe in the initial state; for safety reasons, the TAASC current should not exceed 4 A. The scalp tissue absorbed most of the electromagnetic energy. The TAASC's SAR/thermal performance was close to that of the circular coil.

  20. Thermal heliotrope - A passive sun-tracker

    Science.gov (United States)

    Byxbee, R. C.

    1971-01-01

    Continuous sun tracking device consists of helical bimetallic coil and control mechanism. Coil produces torque and angular displacement with temperature change, and acts as device's driving element. Control mechanism, concentric shading mechanism containing bimetallic sensor coil, controls tracking rate and provides for reset cycle.

  1. Our turbulent sun

    International Nuclear Information System (INIS)

    Frazier, K.

    1982-01-01

    The quest for a new understanding of the sun and its surprising irregularities, variations, and effects is described. Attention is given to the sun's impact on life on earth, the weather and geomagnetic storms, sunspots, solar oscillations, the missing neutrinos in the sun, the 'shrinking sun', the 'dance' of the orbits, and the search for the 'climate connection'. It is noted that the 1980s promise to be the decade of the sun: not only because solar power may be a crucial ingredient in efforts to solve the energy crisis, but also because there will be brilliant auroras over North America, because sunspot activity will be the second highest since the 17th century, and because an unmanned spacecraft (i.e., the solar polar mission) will leave the plane of the solar system and observe the sun from above and below

  2. Sun's dynamics and nucleosynthesis

    International Nuclear Information System (INIS)

    Gavanescu, Adela; Rusu, Mircea V.

    2005-01-01

    Nucleosynthesis processes in the sun are one of the main results related to the evolution of the Sun. Dynamics and energetics of the Sun could be studied indirectly by their elements products in produced by nucleosynthesis. Also solar atmosphere and its characteristics reveled in its full development is observed during the solar eclipses. We try to correlate these facts in order to obtained data to be used in solar models. (authors)

  3. Head Pose Estimation on Top of Haar-Like Face Detection: A Study Using the Kinect Sensor

    Directory of Open Access Journals (Sweden)

    Anwar Saeed

    2015-08-01

    Full Text Available Head pose estimation is a crucial initial task for human face analysis, which is employed in several computer vision systems, such as: facial expression recognition, head gesture recognition, yawn detection, etc. In this work, we propose a frame-based approach to estimate the head pose on top of the Viola and Jones (VJ Haar-like face detector. Several appearance and depth-based feature types are employed for the pose estimation, where comparisons between them in terms of accuracy and speed are presented. It is clearly shown through this work that using the depth data, we improve the accuracy of the head pose estimation. Additionally, we can spot positive detections, faces in profile views detected by the frontal model, that are wrongly cropped due to background disturbances. We introduce a new depth-based feature descriptor that provides competitive estimation results with a lower computation time. Evaluation on a benchmark Kinect database shows that the histogram of oriented gradients and the developed depth-based features are more distinctive for the head pose estimation, where they compare favorably to the current state-of-the-art approaches. Using a concatenation of the aforementioned feature types, we achieved a head pose estimation with average errors not exceeding 5:1; 4:6; 4:2 for pitch, yaw and roll angles, respectively.

  4. Kug Sun Hong

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science. Kug Sun Hong. Articles written in Bulletin of Materials Science. Volume 33 Issue 1 February 2010 pp 43-47 Composites. Microstructure and mechanical properties of Mg–HAP composites · Asit Kumar Khanra Hwa Chul Jung Seung Hoon Yu Kug Sun Hong Kwang Seon Shin.

  5. F F Sun

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science. F F Sun. Articles written in Bulletin of Materials Science. Volume 37 Issue 1 February 2014 pp 71-76. Study of electroless copper plating on ABS resin surface modified by heterocyclic organosilane self-assembled film · H N Zhang J Wang F F Sun D Liu H Y Wang F Wang.

  6. IEEE Solid-State Sensors Workshop Held in Hilton Head Island, South Carolina, on 2-5 June 1986

    Science.gov (United States)

    1987-06-01

    interactions among tLhe attendees. We encourage your active participation in the panel sessions, in the evening rump session, during the presentation...XV.S. Cumberledge - Motorola Inc. 11:10 PANEL : Production of Sensors - Problems, Solutions, and Prospects Moderator. D- Eddy - General Motors Re...This relations- hip is of particular importance for sensor applica- tions. In comparison the temperature coefficient of monocrystalline p-doped

  7. Mechanical Structural Design of a MEMS-Based Piezoresistive Accelerometer for Head Injuries Monitoring: A Computational Analysis by Increments of the Sensor Mass Moment of Inertia †

    Science.gov (United States)

    Messina, Marco; Njuguna, James; Palas, Chrysovalantis

    2018-01-01

    This work focuses on the proof-mass mechanical structural design improvement of a tri-axial piezoresistive accelerometer specifically designed for head injuries monitoring where medium-G impacts are common; for example, in sports such as racing cars or American Football. The device requires the highest sensitivity achievable with a single proof-mass approach, and a very low error (piezoresistors are located (i.e., x- and y-axis) by increasing the MMI in the x- and y-axis, will undoubtedly increase the longitudinal stresses applied in that areas for a given external acceleration, therefore increasing the piezoresistors fractional resistance change and eventually positively affecting the sensor sensitivity. The final device shows a sensitivity increase of about 80% in the z-axis and a reduction of cross-axis sensitivity of 18% respect to state-of-art sensors available in the literature from a previous work of the authors. Sensor design, modelling, and optimization are presented, concluding the work with results, discussion, and conclusion. PMID:29351221

  8. Sensor

    OpenAIRE

    Gleeson, Helen; Dierking, Ingo; Grieve, Bruce; Woodyatt, Christopher; Brimicombe, Paul

    2015-01-01

    An electrical temperature sensor (10) comprises a liquid crystalline material (12). First and second electrically conductive contacts (14), (16), having a spaced relationship there between, contact the liquid crystalline material (12). An electric property measuring device is electrically connected to the first and second contacts (14), (16) and is arranged to measure an electric property of the liquid crystalline material (12). The liquid crystalline material (12) has a transition temperatur...

  9. 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, ...

  10. 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.

  11. Solid-State Sensor and Actuator Workshop Held in Hilton Head Island, South Carolina on 4-7 June 1990

    Science.gov (United States)

    1990-01-01

    0 So So 70 80 90 ZAW Propagation Angle (Degrees) 0 10 20 30 40 S0 60 70 s0 90 Propagation Angle (0) Figure 2. Variation of surface component ot bulk...8opr w7- C: 300 .63,~m 0: I0 X D3x53jum RESULTS 051 0 t 4 Sealed-cavity sensors with rectangular diaphragms, ranging ME 3 from 53 tun x 300 gn to 95 inn

  12. Triana Safehold: A New Gyroless, Sun-Pointing Attitude Controller

    Science.gov (United States)

    Chen, J.; Morgenstern, Wendy; Garrick, Joseph

    2001-01-01

    Triana is a single-string spacecraft to be placed in a halo orbit about the sun-earth Ll Lagrangian point. The Attitude Control Subsystem (ACS) hardware includes four reaction wheels, ten thrusters, six coarse sun sensors, a star tracker, and a three-axis Inertial Measuring Unit (IMU). The ACS Safehold design features a gyroless sun-pointing control scheme using only sun sensors and wheels. With this minimum hardware approach, Safehold increases mission reliability in the event of a gyroscope anomaly. In place of the gyroscope rate measurements, Triana Safehold uses wheel tachometers to help provide a scaled estimation of the spacecraft body rate about the sun vector. Since Triana nominally performs momentum management every three months, its accumulated system momentum can reach a significant fraction of the wheel capacity. It is therefore a requirement for Safehold to maintain a sun-pointing attitude even when the spacecraft system momentum is reasonably large. The tachometer sun-line rate estimation enables the controller to bring the spacecraft close to its desired sun-pointing attitude even with reasonably high system momentum and wheel drags. This paper presents the design rationale behind this gyroless controller, stability analysis, and some time-domain simulation results showing performances with various initial conditions. Finally, suggestions for future improvements are briefly discussed.

  13. Does the sun ring

    International Nuclear Information System (INIS)

    Isaak, G.R.

    1978-01-01

    The work of various groups, which have been investigating the possibility of measuring the periodicities of solar oscillations in an attempt to test theoretical models of the sun, is reported. In particular the observation of small velocity oscillations of the surface layers of the sun that permits the measurement of the sound waves (or phonons) in the solar atmosphere, is discussed. Oscillations with periods of 2.65 h, 58 and 40 min and amplitudes of 2.7, 0.8 and 0.7 ms -1 respectively are reported. Support for a periodicity at about 2.65 h from a number of other groups using other measuring techniques are considered. It is felt that the most probable interpretation of the observed solar oscillations is that the sun is a resonator which is ringing. (UK)

  14. Sun, weather, and climate

    International Nuclear Information System (INIS)

    Herman, J.R.; Goldberg, R.A.

    1985-01-01

    The general field of sun-weather/climate relationships that is, apparent weather and climate responses to solar activity is introduced and theoretical and experimental suggestions for further research to identify and investigate the unknown casual mechanisms are provided. Topics of discussion include: (1) solar-related correlation factors and energy sources; (2) long-term climate trends; (3) short-term meteorological correlations; (4) miscellaneous obscuring influences; (5) physical processes and mechanisms; (6) recapitulation of sun-weather relationships; and (7) guidelines for experiments. 300 references

  15. 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

  16. Intelligent Sun Tracking for a CPV Power Plant

    International Nuclear Information System (INIS)

    Maqsood, Ishtiaq; Emziane, Mahieddine

    2010-01-01

    The output of a solar panel is strongly dependent on the amount of perpendicular light flux falling on its surface, and a tracking system tries to parallel the vector area of the solar panel surface to the incident solar flux. We present a tracking technique based on a two-axis sun sensor which can be used to increase the power output from a number of CPV arrays connected together in a solar power plant. The outdoor testing procedure of the developed two-axis sun sensor is discussed. The detail of the algorithm used together with the related sun tracking equipment is also presented and discussed for the new two axes sun tracking system.

  17. 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...

  18. Licensing the Sun

    Science.gov (United States)

    Demski, Jennifer

    2013-01-01

    The University of San Diego (USD) and Point Loma Nazarene University (PLNU) are licensing the sun. Both California schools are generating solar power on campus without having to sink large amounts of capital into equipment and installation. By negotiating power purchasing agreements (PPAs) with Amsolar and Perpetual Energy Systems, respectively,…

  19. The Sun in Time

    Science.gov (United States)

    Adams, Mitzi L.; Bero, Elizabeth; Sever, Thomas L.

    1999-01-01

    Leveraging funds from NASA's Initiative to Develop Education through Astronomy and Space Science (IDEAS) program, we combined the expertise of an archaeoastronomer, a solar scientist, and a teacher to trace humankind's view of the Sun and how that has changed, from the time of Stonehenge in about 1800 B.C.E., to the time of the Maya in 700 C.E., up to the modem era. Our program was aimed at middle-school students in an attempt to explain not only how science is done today, but how science has evolved from the observations of ancient societies. From these varied cultures, we touched on methods of observing the Sun, ideas of the composition of the Sun, and the relationship of the Sun to everyday life. Further, using the von Braun Astronomical Society's Planetarium in Huntsville, Alabama as a test-bed for the program, we illustrated concepts such as solstices, equinoxes, and local noon with approximately 800 eighth grade students from the local area. Our presentation to SEPA will include a description of NASA's IDEAS program and how to go about partnering with a NASA astronomer, some slides from our planetarium program and web-site, and some hands-on activities.

  20. 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

  1. 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…

  2. 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.

  3. YUAN-BO SUN

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Genetics. YUAN-BO SUN. Articles written in Journal of Genetics. Volume 97 Issue 1 March 2018 pp 173-178 RESEARCH ARTICLE. Investigating multiple dysregulated pathways in rheumatoid arthritis based on pathway interaction network · XIAN-DONG SONG XIAN-XU SONG GUI-BO LIU ...

  4. The Sun on Trial

    Science.gov (United States)

    Robitaille, Pierre-Marie

    2014-03-01

    For 150 years, the Sun has been seen as a gaseous object devoid of a surface, as required by the Standard Solar Model (SSM). Yet, not one line of observational evidence supports a gaseous Sun. In contrast, overwhelming evidence exists that the Sun is comprised of condensed matter. Recently, 40 proofs have been compiled in conjunction with the Liquid Metallic Hydrogen Solar Model (LMHSM). This model advances that the Sun has a true surface. Photospheric structures, such as sunspots, granules, and faculae, are not optical illusions, as in the SSM, but real objects with a condensed nature. The LMHSM accounts for the thermal spectrum by invoking true inter-atomic structure on the photosphere in the form of the graphite-like layered hexagonal metallic hydrogen lattice first proposed by Wigner and Huntington. Within the convection zone, layered metallic hydrogen, insulated by intercalate atoms, enables the generation of the solar dynamo. Electrons located in conduction bands provide a proper means of generating magnetic fields. Metallic hydrogen ejected from the photosphere also thinly populates the corona, as reflected by the continuous K-coronal spectrum. This coronal matter harvests electrons, resulting in the production of highly ionized atoms. Electron affinity, not temperature, governs the ion profile. The chromosphere is a site of hydrogen and proton capture. Line emission in this region, strongly supports the idea that exothermic condensation reactions are occurring in the chromosphere. In the LMHSM, solar activity and solar winds are regulated by exfoliation reactions occurring in the Sun itself, as the metallic hydrogen lattice excludes non-hydrogen elements from the solar body.

  5. Tribute to Sun Kwok

    International Nuclear Information System (INIS)

    Leung, Kam Ching

    2016-01-01

    Sun Kwok was bom in Hong Kong in 1949. He did all his early schooling in Hong Kong and went to the same high school, Pui Ching Middle School, as I did but he was more than a decade later. There are two Education Systems in Hong Kong; the Chinese Language Schools and English Language School. Pui Ching was started by Christian missionaries in China and has a long history of providing quality education. Pui Ching is a Chinese Language School, and during colonial times, school entrance was difficult for students as we were not eligible to apply for admission to the University of Hong Kong, nor were we able to join the civil service. In spite of these handicaps, the school still managed to produce many excellent academics, including one Nobel Prize winner in physics and one Field's medalist in mathematics. Most of its graduates who sought further education went to the U.S. Or Canada as Sun Kwok did. Sun graduated from McMaster University and then went to the University of Minnesota for graduate studies. In the early 1970s, the University of Minnesota had just built one of the world's first infrared bolometers and the astronomers there (Nick Woolf and Ed Ney) were able to make some of the first infrared observations in the mid-infrared region. Through these observations, circumstellar dust was discovered, leading to the realization the evolved stars are losing mass. Sun wrote his PhD thesis on the mass loss mechanism of red giant stars, proposing that the stellar winds are driven by the mechanism of radiation pressure on grains. His 1975 paper is still widely cited to this date. In the same thesis, he showed that OH maser emission is a manifestation of the mass loss process and OH/IR stars are the most heavily mass-losing stars known. He went back to Canada for postdoctoral studies, first at UBC and then at York University. While at York, he applied his knowledge of mass loss to the problem of formation of planetary nebulae, leading to now well-established interacting

  6. 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.

  7. Sun, Moon and Earthquakes

    Science.gov (United States)

    Kolvankar, V. G.

    2013-12-01

    During a study conducted to find the effect of Earth tides on the occurrence of earthquakes, for small areas [typically 1000km X1000km] of high-seismicity regions, it was noticed that the Sun's position in terms of universal time [GMT] shows links to the sum of EMD [longitude of earthquake location - longitude of Moon's foot print on earth] and SEM [Sun-Earth-Moon angle]. This paper provides the details of this relationship after studying earthquake data for over forty high-seismicity regions of the world. It was found that over 98% of the earthquakes for these different regions, examined for the period 1973-2008, show a direct relationship between the Sun's position [GMT] and [EMD+SEM]. As the time changes from 00-24 hours, the factor [EMD+SEM] changes through 360 degree, and plotting these two variables for earthquakes from different small regions reveals a simple 45 degree straight-line relationship between them. This relationship was tested for all earthquakes and earthquake sequences for magnitude 2.0 and above. This study conclusively proves how Sun and the Moon govern all earthquakes. Fig. 12 [A+B]. The left-hand figure provides a 24-hour plot for forty consecutive days including the main event (00:58:23 on 26.12.2004, Lat.+3.30, Long+95.980, Mb 9.0, EQ count 376). The right-hand figure provides an earthquake plot for (EMD+SEM) vs GMT timings for the same data. All the 376 events including the main event faithfully follow the straight-line curve.

  8. 100 billion suns

    International Nuclear Information System (INIS)

    Kippenhahn, R.

    1983-01-01

    A work on the world of astrophysics primarily for lay readers. The author writes only about the discoveries he ''experienced'' during the past 25 years (before 1979). Illustrated somewhat in color plus a set of superb colar plates. Contents, abridged: The long life of stars. The life story of the sun. The life story of massive stars. The end of stars. How stars are born. Planets and their inhabitants

  9. The sun in time

    International Nuclear Information System (INIS)

    Sonett, C.P.; Giampapa, M.S.; Matthews, M.S.

    1991-01-01

    Various papers on solar science are presented. The topics considered include: variability of solar irradiance, sunspot number, solar diameter, and solar wind properties; theory of luminosity and radius variations; standard solar models; the sun and the IMF; variations of cosmic-ray flux with time; accelerated particles in solar flares; solar cosmic ray fluxes during the last 10 million yrs; solar neutrinos and solar history; time variations of Be-10 and solar activity; solar and terrestrial components of the atmospheric C-14 variation spectrum; solar flare heavy-ion tracks in extraterrestrial objects. Also addressed are: the faint young sun problem; atmospheric responses to solar irradiation; quaternary glaciations; solar-terrestrial relationships in recent sea sediments; magnetic history of the sun; pre- and main-sequence evolution of solar activity; magnetic activity in pre-main-sequence stars; classical T Tauri stars; relict magnetism of meteorites; luminosity variability of solar-type stars; evolution of angular momentum in solar-mass stars; time evolution of magnetic fields on solarlike stars

  10. The flight over the sun

    International Nuclear Information System (INIS)

    Ducrocq, A.

    1985-01-01

    With the ''Ulysse'' mission, a satellite is going for the first time to leave the ecliptic plane to observe the sun poles. The ISPM (International Solar Polar Mission) probe will go and visit the sun in passing Jupiter way. Sun pole regions are surmised to play a major role in solar wind production [fr

  11. Sun Radio Interferometer Space Experiment (SunRISE)

    Science.gov (United States)

    Kasper, Justin C.; SunRISE Team

    2018-06-01

    The Sun Radio Interferometer Space Experiment (SunRISE) is a NASA Heliophysics Explorer Mission of Opportunity currently in Phase A. SunRISE is a constellation of spacecraft flying in a 10-km diameter formation and operating as the first imaging radio interferometer in space. The purpose of SunRISE is to reveal critical aspects of solar energetic particle (SEP) acceleration at coronal mass ejections (CMEs) and transport into space by making the first spatially resolved observations of coherent Type II and III radio bursts produced by electrons accelerated at CMEs or released from flares. SunRISE will focus on solar Decametric-Hectometric (DH, 0.1 space before major SEP events, but cannot be seen on Earth due to ionospheric absorption. This talk will describe SunRISE objectives and implementation. Presented on behalf of the entire SunRISE team.

  12. Attitude sensor alignment calibration for the solar maximum mission

    Science.gov (United States)

    Pitone, Daniel S.; Shuster, Malcolm D.

    1990-01-01

    An earlier heuristic study of the fine attitude sensors for the Solar Maximum Mission (SMM) revealed a temperature dependence of the alignment about the yaw axis of the pair of fixed-head star trackers relative to the fine pointing Sun sensor. Here, new sensor alignment algorithms which better quantify the dependence of the alignments on the temperature are developed and applied to the SMM data. Comparison with the results from the previous study reveals the limitations of the heuristic approach. In addition, some of the basic assumptions made in the prelaunch analysis of the alignments of the SMM are examined. The results of this work have important consequences for future missions with stringent attitude requirements and where misalignment variations due to variations in the temperature will be significant.

  13. Heads Up

    Science.gov (United States)

    ... Connect with Us HEADS UP Apps Reshaping the Culture Around Concussion in Sports Get HEADS UP on Your Web Site Concussion ... HEADS UP on your web site! Create a culture of safety for young athletes Officials, learn how you can ... UP to Providers HEADS UP to Youth Sports HEADS UP to School Sports HEADS UP to ...

  14. Activity Monitors Help Users Get Optimum Sun Exposure

    Science.gov (United States)

    2015-01-01

    Goddard scientist Shahid Aslam was investigating alternative methods for measuring extreme ultraviolet radiation on the Solar Dynamics Observatory when he hit upon semiconductors that measured wavelengths pertinent to human health. As a result, he and a partner established College Park, Maryland-based Sensor Sensor LLC and developed UVA+B SunFriend, a wrist monitor that lets people know when they've received their optimal amounts of sunlight for the day.

  15. The Sun in Time

    Science.gov (United States)

    Adams, Mitzi L.; Sever, Thomas L.; Bero, Elizabeth

    1998-01-01

    Using a grant from NASA's Initiative to Develop Education through Astronomy and Space Science (IDEAS) program, we have developed an inter-disciplinary curriculum for middle-school students which targets both history and astronomy. Our curriculum explores the attitudes and techniques of ancient spiritual leaders, specifically those of the Maya and Inca cultures, who observed and tried to control the Sun. We wish students to understand the probable importance of astronomical observations to these ancient peoples. In addition, using the experience of an archaeologist, we show how modern techniques of viewing the Earth through satellite imagery, has allowed the re-discovery of ancient sites where solar observations and attempted manipulation of the universe took place. To contrast ancient observations of the Sun with modern ones, we use the experience of a solar astronomer and bring to the classroom up-to-date information about solar astronomy and the impact of solar activity on the Earth's environment. In this presentation, we will present fragments of our curriculum as well as results from pre- and post-tests given to participating groups of students. Finally, we will discuss comments from local middle-school teachers who were asked to evaluate our curriculum.

  16. 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

  17. Clustering of Sun Exposure Measurements

    OpenAIRE

    Have, Anna Szynkowiak; Larsen, Jan; Hansen, Lars Kai; Philipsen, Peter Alshede; Thieden, Elisabeth; Wulf, Hans Christian

    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 b...

  18. Sun following system adjustment at the UTFSM

    International Nuclear Information System (INIS)

    Georgiev, A.; Roth, P.; Olivares, A.

    2004-01-01

    The 'Evaluacion Solar' Laboratory of the Technical University Federico Santa Maria (UTFSM) in Valparaiso exists since 1957. Some types of sun following systems using instruments for different types of solar measurements were created during the mentioned period in this Laboratory. A solar tracking unit INTRA was recently installed in the UTFSM. It is considered a modern measuring and registering system for actual measuring of radiation in digital form, easier to store and to process. The action of the sun tracker is autonomous, which makes it a flexible tool to support direct radiation measurements. A special device was designed and constructed to support the measuring instruments. Three Eppley pyrheliometers were mounted on the unit and connected with an automatic registering system. An additional UV measuring sensor will be mounted soon. The realized measurements were compared with the results obtained manually from a K and Z pyrheliometer. The difference between both types of pyrheliometers is very small, which is a good precondition for using the INTRA sun tracker for precise measurements in the future

  19. 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...

  20. 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

  1. Self-powered optical sensor systems

    NARCIS (Netherlands)

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

    2009-01-01

    A 0.35 μm CMOS process has been used for on-chip integration of a sun sensor composed of a 2x2 photodiode array and a current-to-voltage amplifier. Unlike conventional sun sensors, a shade profile proportional to the angle of incidence of incoming light is projected onto the photodiodes. This

  2. 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

  3. Creating a Sun-Safe Camp.

    Science.gov (United States)

    Landrey, Ann

    1996-01-01

    Strategies for minimizing sun exposure of campers and staff include educating campers about the sun's effect on their skin, scheduling activities when the sun is less intense, creating shade at the camp site, incorporating sun protection into camp dress code, and training staff regarding sun protection. Addresses OSHA and liability issues. (LP)

  4. 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

  5. A Sun Path Observation System Based on Augment Reality and Mobile Learning

    OpenAIRE

    Tarng, Wernhuar; Ou, Kuo-Liang; Lu, Yun-Chen; Shih, Yi-Syuan; Liou, Hsin-Hun

    2018-01-01

    This study uses the augmented reality technology and sensor functions of GPS, electronic compass, and three-axis accelerometer on mobile devices to develop a Sun path observation system for applications in astronomy education. The orientation and elevation of the Sun can be calculated by the system according to the user’s location and local time to simulate the Sun path. When holding the mobile device toward the sky, the screen will show the virtual Sun at the same position as that of the rea...

  6. Lifestyle, sun worshipping and sun tanning - what about UV-A sun beds?

    International Nuclear Information System (INIS)

    Thune, P.

    1991-01-01

    This article considers the effects of ultraviolet (UV) light from the sun and UV-A sun beds on the skin. Sun worshipping and sun therapy has been en vogue for centuries, but in another way than used today. A changing lifestyle has led to an increase of various skin diseases, including skin cancer. Short wave UV-light (UV-B) in particular has been blamed for inducing not only erythema and pigmentation but also more chronic skin lesions. Long wave UV-light (UV-A) has been shown to be the cause of similar changes to the skin but the pigmentation is of another quality and affords less protection against the harmful effects of UV-B. A concept of sun reactive skin typing has been created. This is based on self-reported responses to an initial exposure to sun as regards tanning ability and erythema reaction. These two factors have certain practical consequences, not only for UV-phototherapy but also for a person's risk of developing skin cancer. Recently, several research groups and dermatologists have discouraged extensive use of UV-A sun beds because of side effects of varying degrees of seriousness. The possible implications of these side effects for the organism are not fully elucidated and may be more profound than known today. The British Photodermatology Group has issued more stringent rules for persons who, despite advice to the contrary, still wish to use UV-A sun beds. 14 refs., 1 tab

  7. ULYSSES OBSERVATIONS OF THE MAGNETIC CONNECTIVITY BETWEEN CORONAL, MASS EJECTIONS AND THE SUN

    Science.gov (United States)

    Riley, Pete; Goslin, J. T.; Crooker, . U.

    2004-01-01

    We have investigated the magnetic connectivity of coronal mass ejections (CMEs) to the Sun using Ulysses observations of suprathermal electrons at various distances between 1 and 5.2 AU. Drawing on ideas concerning the eruption and evolution of CMEs, we had anticipated that there might be a tendency for CMEs to contain progressively more open field lines, as reconnection back at the Sun either opened or completely disconnected previously closed field lines threading the CMEs. Our results, however, did not yield any discernible trend. By combining the potential contribution of CMEs to the heliospheric flux with the observed buildup of flux during the course of the solar cycle, we also derive a lower limit for the reconnection rate of CMEs that is sufficient to avoid the "flux catastrophe" paradox. This rate is well below our threshold of detectability. Subject headings: solar wind - Sun: activity - Sun: corona - Sun: coronal mass ejections (CMEs) - On-line material: color figure Sun: magnetic fields

  8. 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...

  9. Sun exposure, sun protection and sunburn among Canadian adults.

    Science.gov (United States)

    Pinault, Lauren; Fioletov, Vitali

    2017-05-17

    Ultraviolet radiation (UVR) exposure and a history of sunburn are important risk factors for skin cancer. Sunburn is more common among men, younger age groups, and people in higher income households. Sun protection measures also vary by sex, age, and socioeconomic characteristics. Associations between ambient UVR and sunburn and sun safety measures have not been quantified. A total of 53,130 respondents aged 18 or older answered a Canadian Community Health Survey (CCHS) module on sun safety, which was administered in six provinces from 2005 to 2014. The module contained questions about sunburn, time in the sun, and sun protection. These respondents were linked to an ambient erythemal UVR dataset representing the June-to-August mean. Descriptive statistics and logistic regression were used to examine associations between population characteristics, sunburn, sun safety, time in the sun, and ambient UVR. Sunburn was reported by 33% of respondents and was more common among men, younger age groups, people who were not members of visible minorities, residents of higher income households, and individuals who were employed. On a typical summer day, a larger percentage of women than men sought shade and wore sunscreen, whereas a larger percentage of men wore a hat or long pants. As ambient summer UVR increased, women were more likely to apply sunscreen to their face, seek shade, or wear a hat (OR~1.02 to 1.09 per increase of 187 J/m² of erythemally-weighted UVR, or 5.4% of the mean); these associations were not observed among men. Findings related to sunburn and sun protection were similar to those of previous studies. The association between ambient UVR and women's precautionary measures suggests that information about UVR may influence their decision to protect their skin.

  10. Sun-Earth Day, 2001

    Science.gov (United States)

    Adams, Mitzi L.; Mortfield, P.; Hathaway, D. H.; Whitaker, Ann F. (Technical Monitor)

    2001-01-01

    To promote awareness of the Sun-Earth connection, NASA's Marshall Space Flight Center, in collaboration with the Stanford SOLAR Center, sponsored a one-day Sun-Earth Day event on April 27, 2001. Although "celebrated" on only one day, teachers and students from across the nation, prepared for over a month in advance. Workshops were held in March to train teachers. Students performed experiments, results of which were shared through video clips and an internet web cast. Our poster includes highlights from student experiments (grades 2 - 12), lessons learned from the teacher workshops and the event itself, and plans for Sun-Earth Day 2002.

  11. 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...

  12. 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.

  13. Protecting Yourself from Sun Exposure

    Science.gov (United States)

    Fast Facts Protecting Yourself from Sun Exposure Anyone working outdoors is exposed to the sun’s ultraviolet (UV) rays, even on cloudy ... nausea, and fatigue. In addition to the skin, eyes can become sunburned. Sunburned eyes become red, dry, ...

  14. The sun and the neutrinos

    International Nuclear Information System (INIS)

    Forgacsne Dajka, E.

    2000-01-01

    A review of the solar neutrino puzzle is given. The main processes in the sun, the pp-chain and the CNO cycle are described. The solar neutrino puzzle, i.e. the fact that the detected amount of neutrinos coming from the sun is less than the amount predicted by the solar model is discussed. The first generation solar neutrino experiments are presented. (K.A.)

  15. Sun Protection Among New Zealand Primary School Children.

    Science.gov (United States)

    Gage, Ryan; Leung, William; Stanley, James; Reeder, Anthony; Mackay, Christina; Smith, Moira; Barr, Michelle; Chambers, Tim; Signal, Louise

    2017-12-01

    Schools are an important setting for raising skin cancer prevention awareness and encouraging sun protection. We assessed the clothes worn and shade used by 1,278 children in eight schools in the Wellington region of New Zealand. These children were photographed for the Kids'Cam project between September 2014 and March 2015 during school lunch breaks. Children's mean clothing coverage (expressed as a percentage of body area covered) was calculated. Data on school sun-safety policies were obtained via telephone. Mean total body clothing coverage was 70.3% (95% confidence interval = 66.3%, 73.8%). Body regions with the lowest mean coverage were the head (15.4% coverage), neck (36.1% coverage), lower arms (46.1% coverage), hands (5.3% coverage), and calves (30.1% coverage). Children from schools with hats as part of the school uniform were significantly more likely to wear a hat (52.2%) than children from schools without a school hat (2.7%). Most children (78.4%) were not under the cover of shade. Our findings suggest that New Zealand children are not sufficiently protected from the sun at school. Schools should consider comprehensive approaches to improve sun protection, such as the provision of school hats, sun-protective uniforms, and the construction of effective shade.

  16. Sun glitter imaging analysis of submarine sand waves in HJ-1A/B satellite CCD images

    Science.gov (United States)

    Zhang, Huaguo; He, Xiekai; Yang, Kang; Fu, Bin; Guan, Weibing

    2014-11-01

    Submarine sand waves are a widespread bed-form in tidal environment. Submarine sand waves induce current convergence and divergence that affect sea surface roughness thus become visible in sun glitter images. These sun glitter images have been employed for mapping sand wave topography. However, there are lots of effect factors in sun glitter imaging of the submarine sand waves, such as the imaging geometry and dynamic environment condition. In this paper, several sun glitter images from HJ-1A/B in the Taiwan Banks are selected. These satellite sun glitter images are used to discuss sun glitter imaging characteristics in different sensor parameters and dynamic environment condition. To interpret the imaging characteristics, calculating the sun glitter radiance and analyzing its spatial characteristics of the sand wave in different images is the best way. In this study, a simulated model based on sun glitter radiation transmission is adopted to certify the imaging analysis in further. Some results are drawn based on the study. Firstly, the sun glitter radiation is mainly determined by sensor view angle. Second, the current is another key factor for the sun glitter. The opposite current direction will cause exchanging of bright stripes and dark stripes. Third, brightness reversal would happen at the critical angle. Therefore, when using sun glitter image to obtain depth inversion, one is advised to take advantage of image properties of sand waves and to pay attention to key dynamic environment condition and brightness reversal.

  17. 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.

  18. Automatic Hotspot and Sun Glint Detection in UAV Multispectral Images.

    Science.gov (United States)

    Ortega-Terol, Damian; Hernandez-Lopez, David; Ballesteros, Rocio; Gonzalez-Aguilera, Diego

    2017-10-15

    Last advances in sensors, photogrammetry and computer vision have led to high-automation levels of 3D reconstruction processes for generating dense models and multispectral orthoimages from Unmanned Aerial Vehicle (UAV) images. However, these cartographic products are sometimes blurred and degraded due to sun reflection effects which reduce the image contrast and colour fidelity in photogrammetry and the quality of radiometric values in remote sensing applications. This paper proposes an automatic approach for detecting sun reflections problems (hotspot and sun glint) in multispectral images acquired with an Unmanned Aerial Vehicle (UAV), based on a photogrammetric strategy included in a flight planning and control software developed by the authors. In particular, two main consequences are derived from the approach developed: (i) different areas of the images can be excluded since they contain sun reflection problems; (ii) the cartographic products obtained (e.g., digital terrain model, orthoimages) and the agronomical parameters computed (e.g., normalized vegetation index-NVDI) are improved since radiometric defects in pixels are not considered. Finally, an accuracy assessment was performed in order to analyse the error in the detection process, getting errors around 10 pixels for a ground sample distance (GSD) of 5 cm which is perfectly valid for agricultural applications. This error confirms that the precision in the detection of sun reflections can be guaranteed using this approach and the current low-cost UAV technology.

  19. 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.

  20. Sun Exposure and Psychotic Experiences

    Directory of Open Access Journals (Sweden)

    Izabela Pilecka

    2017-06-01

    Full Text Available ObjectiveSun exposure is considered the single most important source of vitamin D. Vitamin D deficiency has been suggested to play a role in the etiology of psychotic disorders. The aim of the present study was to evaluate the association between sun exposure and psychotic experiences (PEs in a general population sample of Swedish women.MethodsThe study population included participants from The Swedish Women’s Lifestyle and Health cohort study. The 20-item community assessment of psychic experiences (CAPEs was administered between ages 30 and 50 to establish PEs. Sun exposure as measured by (1 sunbathing holidays and (2 history of sunburn was measured between ages 10 and 39. The association between sun exposure and PEs was evaluated by quantile regression models.Results34,297 women were included in the analysis. Women who reported no sunbathing holidays and 2 or more weeks of sunbathing holidays scored higher on the CAPE scale than women exposed to 1 week of sunbathing holidays across the entire distribution, when adjusting for age and education. Similarly, compared with women who reported a history of one sunburn, the women with none or two or more sunburns showed higher scores on the CAPE scale.ConclusionThe results of the present study suggest that, in a population-based cohort of middle aged women, both low and high sun exposure is associated with increased level of positive PEs.

  1. SU(N) Irreducible Schwinger Bosons

    OpenAIRE

    Mathur, Manu; Raychowdhury, Indrakshi; Anishetty, Ramesh

    2010-01-01

    We construct SU(N) irreducible Schwinger bosons satisfying certain U(N-1) constraints which implement the symmetries of SU(N) Young tableaues. As a result all SU(N) irreducible representations are simple monomials of $(N-1)$ types of SU(N) irreducible Schwinger bosons. Further, we show that these representations are free of multiplicity problems. Thus all SU(N) representations are made as simple as SU(2).

  2. 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...... in the questionnaire. Exposure measured in SED by dosimetry correlated strongly with the exposure scale. In a linear regression model of UVR (SED) received, 41 percent of the variation was explained by skin type, age, week of participation and the exposure scale, with the exposure scale as the main contributor...

  3. Nuclear astrophysics of the sun

    International Nuclear Information System (INIS)

    Kocharov, G.E.

    1980-01-01

    In the first chapter we will discuss the problem of nuclear reactions in the interior of the sun and consider the modern aspects of the neutrino astrophysics of the Sun. The second chapter is devoted to the high energy interactions in the solar atmosphere during the flares. Among a great number of events during the solar flares we shall consider mainly the nuclear reactions. Special attention will be paid to the genetic connection between the different components of solar electromagnetic and corpuscular radiation. The idea of the unity of processes in different parts of the Sun, from hot and dense interior up to the rare plasma of the solar corona will be the main line of the book. (orig./WL) 891 WL/orig.- 892 HIS

  4. Torsional oscillations of the sun

    International Nuclear Information System (INIS)

    Snodgrass, H.B.; Howard, R.; National Solar Observatory, Tucson, AZ)

    1985-01-01

    The sun's differential rotation has a cyclic pattern of change that is tightly correlated with the sunspot, or magnetic activity, cycle. This pattern can be described as a torsional oscillation, in which the solar rotation is periodically sped up or slowed down in certain zones of latitude while elsewhere the rotation remains essentially steady. The zones of anomalous rotation move on the sun in wavelike fashion, keeping pace with and flanking the zones of magnetic activity. It is uncertain whether this torsional oscillation is a globally coherent ringing of the sun or whether it is a local pattern caused by and causing local changes in the magnetic fields. In either case, it may be an important link in the connection between the rotation and the cycle that is widely believed to exist but is not yet understood. 46 references

  5. Fibre optic strain sensor: examples of applications

    Science.gov (United States)

    Kruszewski, J.; Beblowska, M.; Wrzosek, P.

    2006-03-01

    Construction of strain sensor for application in safety systems has been presented. The device consists of sensor's head and source and detector units. The head is made of polymer fiber bends. Designed sensor could be mounted in monitoring place (e.g. under a floor) and controlled by PC unit or could be used as a portable device for a valuable object protection.

  6. SunBlock '99: Young Scientists Investigate the Sun

    Science.gov (United States)

    Walsh, R. W.; Pike, C. D.; Mason, H.; Young, P.; Ireland, J.; Galsgaard, K.

    1999-10-01

    SunBlock `99 is a Web-based Public Understanding of Science and educational project which seeks to present the very latest solar research as seen through the eyes of young British scientists. These ``solar guides'' discuss not only their scientific interests, but also their extra-curricular activities and the reasons they chose scientific careers; in other words the human face of scientific research. The SunBlock '99 pages gather a range of solar images and movies from current solar space observatories and discuss the underlying physics and its relationship to the school curriculum. The instructional level is pitched at UK secondary school children (aged 13-16 years). It is intended that the material should not only provide a visually appealing introduction to the study of the Sun, but that it should help bridge the often wide gap between classroom science lessons and the research scientist `out in the field'. SunBlock '99 is managed by a team from the Rutherford Appleton Laboratory and the Universities of St Andrews and Cambridge, together with educational consultants. The production has, in part, been sponsored by PPARC and the Millennium Mathematics Project. Web site addresss: http://www.sunblock99.org.uk

  7. Sun and Skin: The Dark Side of Sun Exposure

    Science.gov (United States)

    ... a toll on your skin and its underlying connective tissue. As a result, your skin may develop more wrinkles and lines. Too much sun exposure can also raise your risk for skin cancer, the most common type of cancer in the ...

  8. Design and fabrication of sun tracker

    International Nuclear Information System (INIS)

    Novinrooz, A. J.; Ghasemi, M. R.; Mohati, M.; Sadri, H.

    2003-01-01

    A sun tacker system, consists of two parts (opto-electronic and hydraulic), has been designed and fabricated to be used in solar thermal power plant. In this paper various parts of the system including optical sensors, electronic circuits, computational control and mechanical lever have been explained and the operational mechanism of each one is discussed. The parabolic mirror used in this plant has 400 cm length, 570 cm width and 170 cm focal length. Rays falling to the axis of mirror are reflected and collected at the focal point, while unparallel rays are diverted. To determine the rate of divergence, a three - dimensional equation of radiation path is written. Using a computational program in Cl anguage the error is calculated from 0t o 0 .5 d eg, for modifying the operational error of the optical system. The optical sensors detect the beam deviation from the mirror's principal axis with a precision of 0.1 degree and transfer the necessary corrections to the active mechanical system of the hydraulic type. A three phase electro motor of 0.7 k W power and one thousand revolutions per minute controls the mirror movement

  9. 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,…

  10. 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)

  11. Teaching "Empire of the Sun."

    Science.gov (United States)

    Riet, Fred H. van

    1990-01-01

    A Dutch teacher presents reading, film viewing, and writing activities for "Empire of the Sun," J. G. Ballard's autobiographical account of life as a boy in Shanghai and in a Japanese internment camp during World War II (the subject of Steven Spielberg's film of the same name). Includes objectives, procedures, and several literature,…

  12. The Award Winning Black Suns

    Science.gov (United States)

    Holbrook, Jarita

    2018-01-01

    Black Suns: An Astrophysics Adventure is a documentary film focusing on the annular and total solar eclipses of 2012. We made a different kind of astronomy documentary showing the human aspects rather than just focusing on pretty astronomy pictures. The film combines personal stories with science. Our heroes are Hakeem Oluseyi and Alphonse Sterling, who valiantly travel to study the solar corona during total solar eclipses. The goals of the film included presenting three dimensional scientists, to show their paths to becoming astrophysicists, and to show them as they collect data and work as scientists. Drama and tension surround taking data during the small window of time during totality. The Black Suns was filmed in Tokyo, Cairns, Tucson, and Melbourne Florida. Uniquely, the film began through a Kickstarter campaign to fund travel and filming in Tokyo. Many American Astronomical Society members donated to the film! Black Suns won the Jury Prize at the 2017 Art of Brooklyn Film Festival. Black Suns will be screening in full on ???.

  13. Sun-view angle effects on reflectance factors of corn canopies

    Science.gov (United States)

    Ranson, K. J.; Daughtry, C. S. T.; Biehl, L. L.; Bauer, M. E.

    1985-01-01

    The effects of sun and view angles on reflectance factors of corn (Zea mays L.) canopies ranging from the six leaf stage to harvest maturity were studied on the Purdue University Agronomy Farm by a multiband radiometer. The two methods of acquiring spectral data, the truck system and the tower systrem, are described. The analysis of the spectral data is presented in three parts: solar angle effects on reflectance factors viewed at nadir; solar angle effects on reflectance factors viewed at a fixed sun angle; and both sun and view angles effect on reflectance factors. The analysis revealed that for nadir-viewed reflectance factors there is a strong solar angle dependence in all spectral bands for canopies with low leaf area index. Reflectance factors observed from the sun angle at different view azimuth angles showed that the position of the sensor relative to the sun is important in determining angular reflectance characteristics. For both sun and view angles, reflectance factors are maximized when the sensor view direction is towards the sun.

  14. Sun Exposure, Sun-Related Symptoms, and Sun Protection Practices in an African Informal Traditional Medicines Market.

    Science.gov (United States)

    Wright, Caradee Y; Reddy, Tarylee; Mathee, Angela; Street, Renée A

    2017-09-28

    Informal workers in African market trade have little formal protection against sun exposure. We aimed to examine sun exposure, sun-related symptoms, and sun protection practices in an informal occupational setting. Trained fieldworkers asked 236 workers in the Warwick Junction market about their workplace, skin and eye sensitivity and skin colour, symptoms faced at work during the summer due to heat, and preventive measures. Data were analyzed using univariate logistic regression to assess the effect of gender and the risk of experiencing symptoms to sun exposure in relation to pre-existing diseases and perception of sun exposure as a hazard. Of the 236 participants, 234 were Black African and 141 (59.7%) were female. Portable shade was the most commonly used form of sun protection (69.9%). Glare from the sun (59.7%) and excessive sweating (57.6%) were commonly reported sun-related health symptoms. The use of protective clothing was more prevalent among those who perceived sun exposure as a hazard ( p = 0.003). In an informal occupational setting, sun exposure was high. Protective clothing and portable shade to eliminate heat and bright light were self-implemented. Action by local authorities to protect informal workers should consider sun exposure to support workers in their efforts to cope in hot weather.

  15. Sun Exposure, Sun-Related Symptoms, and Sun Protection Practices in an African Informal Traditional Medicines Market

    Directory of Open Access Journals (Sweden)

    Caradee Y. Wright

    2017-09-01

    Full Text Available Informal workers in African market trade have little formal protection against sun exposure. We aimed to examine sun exposure, sun-related symptoms, and sun protection practices in an informal occupational setting. Trained fieldworkers asked 236 workers in the Warwick Junction market about their workplace, skin and eye sensitivity and skin colour, symptoms faced at work during the summer due to heat, and preventive measures. Data were analyzed using univariate logistic regression to assess the effect of gender and the risk of experiencing symptoms to sun exposure in relation to pre-existing diseases and perception of sun exposure as a hazard. Of the 236 participants, 234 were Black African and 141 (59.7% were female. Portable shade was the most commonly used form of sun protection (69.9%. Glare from the sun (59.7% and excessive sweating (57.6% were commonly reported sun-related health symptoms. The use of protective clothing was more prevalent among those who perceived sun exposure as a hazard (p = 0.003. In an informal occupational setting, sun exposure was high. Protective clothing and portable shade to eliminate heat and bright light were self-implemented. Action by local authorities to protect informal workers should consider sun exposure to support workers in their efforts to cope in hot weather.

  16. Sun, UV Radiation and Your Eyes

    Science.gov (United States)

    ... Sunglasses Sun Smart UV Safety Infographic The Sun, UV Radiation and Your Eyes Leer en Español: El ... Aug. 28, 2014 Keep an Eye on Ultraviolet (UV) Safety Eye medical doctors (ophthalmologists) caution us that ...

  17. Our prodigal sun. [solar energy technology

    Science.gov (United States)

    1974-01-01

    Characteristics of the sun are reported indicating it as a source of energy. Data from several space missions are discussed, and the solar activity cycle is presented. The corona, flares, prominences, spots, and wind of the sun are also discussed.

  18. 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")

  19. Essential Outdoor Sun Safety Tips for Winter

    Science.gov (United States)

    ... Weekend Warriors expand/collapse Vitamin D Essential Outdoor Sun Safety Tips for Winter Winter sports enthusiasts are ... skiing! Be Mindful of Time Spent in the Sun, Regardless of the Season If possible, ski early ...

  20. Head Lice

    Science.gov (United States)

    ... nits. You should also use hot water to wash any bed linens, towels, and clothing recently worn by the person who had head lice. Vacuum anything that can’t be washed, such as the couch, carpets, your child’s car seat, and any stuffed animals. Because head lice ...

  1. 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.

  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. Can the Sun replace uranium

    International Nuclear Information System (INIS)

    Weinberg, A.M.

    1977-07-01

    Two asymptotic worlds, one based on solar energy, the other based on nuclear energy, are compared. The total energy demand in each case is 2,000 quads. Although the Sun can in principal supply this energy, it probably will be very expensive. If the energy were supplied entirely by breeders, the nuclear energy system would pose formidable systems problems--particularly safety and proliferation. It is suggested that in view of these possible difficulties, all options must be kept open

  4. 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...

  5. Integrable multi parametric SU(N) chain

    International Nuclear Information System (INIS)

    Foerster, Angela; Roditi, Itzhak; Rodrigues, Ligia M.C.S.

    1996-03-01

    We analyse integrable models associated to a multi parametric SU(N) R-matrix. We show that the Hamiltonians describe SU(N) chains with twisted boundary conditions and that the underlying algebraic structure is the multi parametric deformation of SU(N) enlarged by the introduction of a central element. (author). 15 refs

  6. Sun Tracker Operates a Year Between Calibrations

    Science.gov (United States)

    Berdahl, C. M.

    1984-01-01

    Low-cost modification of Sun tracker automatically compensates equation of time and seasonal variations in declination of Sun. Output of Scotch Yoke drive mechanism adjusted through proper sizing of crank, yoke and other components and through choice of gear ratios to approximate seasonal northand south motion of Sun. Used for industrial solar-energy monitoring and in remote meteorological stations.

  7. Sun tracker for clear or cloudy weather

    Science.gov (United States)

    Scott, D. R.; White, P. R.

    1979-01-01

    Sun tracker orients solar collector so that they absorb maximum possible sunlight without being fooled by bright clouds, holes in cloud cover, or other atmospheric conditions. Tracker follows sun within 0.25 deg arc and is accurate within + or - 5 deg when sun is hidden.

  8. The Logic-Based Supervisor Control for Sun-Tracking System of 1 MW HCPV Demo Plant: Study Case

    Directory of Open Access Journals (Sweden)

    Hong-Yih Yeh

    2012-02-01

    Full Text Available This paper presents a logic-based supervisor controller designed for trackers for a 1MW HCPV demo plant in Taiwan. A sun position sensor on the tracker is used to detect the sun position, as the sensor is sensitive to the intensity of sun light. The signal output of the sensor is partially affected by the cloud, which has a hard control position with the traditional PID control. Therefore we have used logic-based supervisor (LBS control which permits switching the PID control to sun trajectory under sunny or cloudy conditions. To verify the stability of the proposed control, an experiment was performed and the results show that the proposed control can efficiently achieve stabilization of the trackers of the 1MW HCPV demo plant.

  9. Temperature dependence of attitude sensor coalignments on the Solar Maximum Mission (SMM)

    Science.gov (United States)

    Pitone, D. S.; Eudell, A. H.; Patt, F. S.

    1990-01-01

    The temperature correlation of the relative coalignment between the fine-pointing sun sensor and fixed-head star trackers measured on the Solar Maximum Mission (SMM) is analyzed. An overview of the SMM, including mission history and configuration, is given. Possible causes of the misalignment variation are discussed, with focus placed on spacecraft bending due to solar-radiation pressure, electronic or mechanical changes in the sensors, uncertainty in the attitude solutions, and mounting-plate expansion and contraction due to thermal effects. Yaw misalignment variation from the temperature profile is assessed, and suggestions for spacecraft operations are presented, involving methods to incorporate flight measurements of the temperature-versus-alignment function and its variance in operational procedures and the spacecraft structure temperatures in the attitude telemetry record.

  10. Head Injuries

    Science.gov (United States)

    ... a severe blow to the head can still knock the brain into the side of the skull ... following certain precautions and taking a break from sports and other activities that make symptoms worse. Playing ...

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

    Science.gov (United States)

    Kasper, J. C.; Lazio, J.; Alibay, F.; Amiri, N.; Bastian, T.; Cohen, C.; Landi, E.; Hegedus, A. M.; Maksimovic, M.; Manchester, W.; Reinard, A.; Schwadron, N.; Cecconi, B.; Hallinan, G.; Krupar, V.

    2017-12-01

    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 R_S. 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 (nu > 15 MHz), which in turn limits the range of solar distances over which they can track the radio emission (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.

  12. SU(N,1) inflation

    International Nuclear Information System (INIS)

    Ellis, J.; Enqvist, K.; Nanopoulos, D.V.; Olive, K.A.; Srednicki, M.

    1985-01-01

    We present a simple model for primordial inflation in the context of SU(N, 1) no-scale n=1 supergravity. Because the model at zero temperature very closely resembles global supersymmetry, minima with negative cosmological constants do not exist, and it is easy to have a long inflationary epoch while keeping density perturbations of the right magnitude and satisfying other cosmological constraints. We pay specific attention to satisfying the thermal constraint for inflation, i.e. the existence of a high temperature minimum at the origin. (orig.)

  13. A Sun Path Observation System Based on Augment Reality and Mobile Learning

    Directory of Open Access Journals (Sweden)

    Wernhuar Tarng

    2018-01-01

    Full Text Available This study uses the augmented reality technology and sensor functions of GPS, electronic compass, and three-axis accelerometer on mobile devices to develop a Sun path observation system for applications in astronomy education. The orientation and elevation of the Sun can be calculated by the system according to the user’s location and local time to simulate the Sun path. When holding the mobile device toward the sky, the screen will show the virtual Sun at the same position as that of the real Sun. The user can record the Sun path and the data of observation date, time, longitude, and latitude using the celestial hemisphere and the pole shadow on the system. By setting different observation times and locations, it can be seen that the Sun path changes with seasons and latitudes. The system provides contextual awareness of the Sun path concepts, and it can convert the observation data into organized and meaningful astronomical knowledge to enable combination of situated learning with spatial cognition. The system can solve the problem of being not able to record the Sun path due to a bad weather or topographical restrictions, and therefore it is helpful for elementary students when conducting observations. A teaching experiment has been conducted to analyze the learning achievement of students after using the system, and the results show that it is more effective than traditional teaching aids. The questionnaire results also reveal that the system is easy to operate and useful in recording the Sun path data. Therefore, it is an effective tool for astronomy education in elementary schools.

  14. 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

  15. Sun-Compass Orientation in Mediterranean Fish Larvae.

    Science.gov (United States)

    Faillettaz, Robin; Blandin, Agathe; Paris, Claire B; Koubbi, Philippe; Irisson, Jean-Olivier

    2015-01-01

    Mortality is very high during the pelagic larval phase of fishes but the factors that determine recruitment success remain unclear and hard to predict. Because of their bipartite life history, larvae of coastal species have to head back to the shore at the end of their pelagic episode, to settle. These settlement-stage larvae are known to display strong sensory and motile abilities, but most work has been focused on tropical, insular environments and on the influence of coast-related cues on orientation. In this study we quantified the in situ orientation behavior of settlement-stage larvae in a temperate region, with a continuous coast and a dominant along-shore current, and inspected both coast-dependent and independent cues. We tested six species: one Pomacentridae, Chromis chromis, and five Sparidae, Boops boops, Diplodus annularis, Oblada melanura, Spicara smaris and Spondyliosoma cantharus. Over 85% of larvae were highly capable of keeping a bearing, which is comparable to the orientation abilities of tropical species. Sun-related cues influenced the precision of bearing-keeping at individual level. Three species, out of the four tested in sufficient numbers, oriented significantly relative to the sun position. These are the first in situ observations demonstrating the use of a sun compass for orientation by wild-caught settlement-stage larvae. This mechanism has potential for large-scale orientation of fish larvae globally.

  16. Sun-Compass Orientation in Mediterranean Fish Larvae.

    Directory of Open Access Journals (Sweden)

    Robin Faillettaz

    Full Text Available Mortality is very high during the pelagic larval phase of fishes but the factors that determine recruitment success remain unclear and hard to predict. Because of their bipartite life history, larvae of coastal species have to head back to the shore at the end of their pelagic episode, to settle. These settlement-stage larvae are known to display strong sensory and motile abilities, but most work has been focused on tropical, insular environments and on the influence of coast-related cues on orientation. In this study we quantified the in situ orientation behavior of settlement-stage larvae in a temperate region, with a continuous coast and a dominant along-shore current, and inspected both coast-dependent and independent cues. We tested six species: one Pomacentridae, Chromis chromis, and five Sparidae, Boops boops, Diplodus annularis, Oblada melanura, Spicara smaris and Spondyliosoma cantharus. Over 85% of larvae were highly capable of keeping a bearing, which is comparable to the orientation abilities of tropical species. Sun-related cues influenced the precision of bearing-keeping at individual level. Three species, out of the four tested in sufficient numbers, oriented significantly relative to the sun position. These are the first in situ observations demonstrating the use of a sun compass for orientation by wild-caught settlement-stage larvae. This mechanism has potential for large-scale orientation of fish larvae globally.

  17. Skin Tone Dissatisfaction, Sun Exposure, and Sun Protection in Australian Adolescents.

    Science.gov (United States)

    Hutchinson, Amanda D; Prichard, Ivanka; Ettridge, Kerry; Wilson, Carlene

    2015-08-01

    This study aimed to assess the adoption of sun protection and sun exposure behaviors, the extent to which these behaviors group together, and the relationship between skin tone dissatisfaction and sun-related behaviors in South Australian adolescents (aged 12-17). A total of 2,875 secondary school students (1,461 male and 1,414 female) completed a questionnaire including questions about sun protection and sun exposure behaviors and skin tone dissatisfaction. Regular adoption of sun protection behaviors was low and ranged from 20% (wearing protective clothing) to 44% (sunscreen use). A principal components analysis identified four subgroups of sun-related behaviors: sun protection, appearance enhancement, sun avoidance, and sun exposure. Females had significantly higher skin tone dissatisfaction than males. Skin tone dissatisfaction was associated with decreased sun protection and avoidance and increased appearance enhancement and sun exposure in both males and females. Skin tone dissatisfaction plays an important role in Australian adolescents' sun-related behavior. Appearance-based interventions may be effective in reducing skin cancer risk through reduced sun exposure.

  18. Sun and planet detection system for satellites. Sonnen- und Erderfassungsverfahren fuer Satelliten

    Energy Technology Data Exchange (ETDEWEB)

    Lange, B O; Scheit, A

    1980-05-22

    The invention refers to a process for the sun and planet detection system for satellites stabilised in three axes and equipped with detection sensors. The purpose of the invention is to describe such a detection system, which makes quick and reliable guiding of the satellite to its final position possible, permits the use of sensors of simple construction and of simple control laws and simple control logic. According to the invention, this problem is solved by having cumulative or alternate steps, depending on the position of the satellite relative to the sun. According to the invention they refer to the position of the sun outside the field of view for the measurement of various components and the simultaneous availability of several component values. It is particularly advantageous if only the absolutely necessary satellite manoeuvres have to be carried out, as this saves fuel and makes it possible to increase the payload or extend the satellite's life. (HWJ).

  19. 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.

  20. Using Online Active-Learning Techniques to Convey Time Compensated Sun Compass Orientation in the Eastern North American Monarch

    OpenAIRE

    Noah Hammond Green; Douglas G. McMahon; Cynthia Brame

    2016-01-01

    A common tool that animals use to navigate in a constant direction is known as ?time compensated sun compass orientation.? This is a process by which animals use the position of the sun along with information from their internal circadian clocks to determine and maintain a directional heading. Many circadian scientists and educators use this process as an example of how the internal circadian clock can directly influence animal behavior. However, many students have difficulty grasping this bi...

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

    Science.gov (United States)

    1996-07-01

    accelerator works. "Some of the big rewards from SOHO will come from better and more continuous observation" comments Vicente Domingo, ESA's project scientist for SOHO. "In other cases wholly new results will help to decide between conflicting theories. UVCS's high-speed oxygen atoms at the source of the fast solar wind are one case in point. Sub-surface motions revealed by MDI are another." Sub-surface flows show pancake-like features MDI is SOHO's oscillations imager and it is the most elaborate of the instruments that probe inside the Sun by helioseismology, using oscillations at the visible surface due to sound waves reverberating through the interior. MDI divides the Sun's surface into a million points and measures vertical motions once a minute by small changes of the wavelength of light. Deducing flows just below the visible surface requires prolonged calculations with a supercomputer. These detect small changes in the travel-time of sound waves according to whether they are heading into, or travelling with, the flow of material inside the Sun. After mapping sub-surface flows across a wide area, the MDI team has analysed a vertical slice. Along a 300,000-kilometre line at the Sun's equator, the computation cuts 8000 kilometres deep into the turbulent convection zone, where the outer part of the Sun boils like a kettle. The main convection cells that link ascending and descending flows turn out to be surprisingly shallow and pancake-like. They reach down about 1500 kilometres, compared with about 4000 kilometres expected by some theorists. Further results from an intensive observing campaign will enable the MDI scientists to confirm that their first results are typical, and to make a movie to see how structures change with time. Stormy weather ahead The oscillation imager MDI also charts magnetic fields running in and out of the Sun's surface. The speckled pattern that it sees will change dramatically in the years ahead, when the Sun is due to swap its north and south

  2. SUN1 splice variants, SUN1_888, SUN1_785, and predominant SUN1_916, variably function in directional cell migration

    OpenAIRE

    Nishioka, Yu; Imaizumi, Hiromasa; Imada, Junko; Katahira, Jun; Matsuura, Nariaki; Hieda, Miki

    2016-01-01

    The LINC complex is a multifunctional protein complex that is involved in various processes at the nuclear envelope, such as nuclear migration, mechanotransduction and chromatin tethering in the meiotic phase. However, it remains unknown how these functions are regulated in different cell contexts. An inner nuclear membrane component of the LINC complex, SUN1, is ubiquitously expressed. The human SUN1 gene produces over 10 variants by alternative splicing. Although functions of SUN1 are relat...

  3. The shivering sun opens its heart

    International Nuclear Information System (INIS)

    Gough, D.

    1976-01-01

    Recent discoveries, by various workers, of global oscillations of the Sun are summarised. The two major ways in which the Sun can vibrate, as a standing acoustic wave and as a standing gravity wave, are discussed. The recently discovered oscillations provide a new rich class of data with which to test theoretical models of the internal structure of the Sun. The implications of these new data with reference to solar models are considered. (U.K.)

  4. Head Start.

    Science.gov (United States)

    Greenman, Geri

    2000-01-01

    Discusses an art project in which students created drawings of mop heads. Explains that the approach of drawing was more important than the subject. States that the students used the chiaroscuro technique, used by Rembrandt and Caravaggio, in which light appears out of the darkness. (CMK)

  5. Coherent states related with SU(N) and SU(N,1) groups

    International Nuclear Information System (INIS)

    Gitman, D.M.; Shelepin, A.L.

    1990-01-01

    The basis of coherent state (CS) for symmetric presentations of groups SU(N) and SU(N,1) is plotted, its properties being investigated. Evolution of CS is considered. Relation between CS of groups SU(N) and Glauber is ascertained

  6. Sun protection counseling by pediatricians has little effect on parent and child sun protection behavior.

    Science.gov (United States)

    Cohen, Liza; Brown, Judith; Haukness, Heather; Walsh, Lori; Robinson, June K

    2013-02-01

    To compare counseling concerning sun protection and outdoor exercise with the parent's report of the behavior of a child aged 9-16 years old. Structured interviews of medical personnel in 3 Chicago area practices elicited information about counseling methods and recommendations. In each practice, a convenience sample of parents completed a self-reported survey of their and their child's behavior. Sun protection counseling occurred more frequently than exercise counseling in all practices (P = .014). Sun protection counseling was associated with parental prompting (P = .004), performing a summer camp physical (P = .002), and the child having a sunburn (P = .003). After controlling for the child's age, sex, and skin tone, sun protection counseling was not associated with the child's use of sun protection. In multivariate analysis of the child's sun protection behavior, parental sunburns, indoor tanning in the last 12 months, perception of skin cancer risk, and sun protection self-efficacy were significant (P = .02). Children who pursued outdoor sports were twice as likely to use inadequate sun protection and sustain sunburns (CI 1.3-1.7). The child's sun protection behavior was influenced by parental sun protection, parental perception of skin cancer risk, and parental sun protection self-efficacy; therefore, sun protection for children needs to be aimed at parents as well as children. Communication with parents in a way that incorporates the principles of motivational interviewing may be more effective in promoting behavioral change than admonitions to use sunscreen. Copyright © 2013 Mosby, Inc. All rights reserved.

  7. Sun Protection for Children: A Review

    Directory of Open Access Journals (Sweden)

    Nazanin Shafie Pour

    2015-01-01

    Full Text Available Chronic ultraviolet exposure results in premature skin aging (photoaging, dyspigmentation, sallow color, textural changes, loss of elasticity, and premalignant actinic keratoses. UVB radiation is mainly responsible for acute damages such as sunburn, and long-term damage including melanoma. Today the sun's ultraviolet radiation (UVR induced skin cancer is a major issue worldwide. History of sun exposure and sunburns are the most important behavioral risks. Childhood sun exposure is considered as a substantial risk because a child’s skin has a thinner stratum corneum, lower levels of protective melanin, and a higher surface area to body-mass-ratio. Thus, protection against UVR in childhood is essential. Research has shown that people who have had a sunburn in childhood or were in the sun unprotected are more likely to have skin cancer. In this article, we review the literature to address the protection of children against sun and skin cancer.

  8. 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.

  9. 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.

  10. SunPy—Python for solar physics

    International Nuclear Information System (INIS)

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

    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. (paper)

  11. Flued head replacement alternatives

    International Nuclear Information System (INIS)

    Smetters, J.L.

    1987-01-01

    This paper discusses flued head replacement options. Section 2 discusses complete flued head replacement with a design that eliminates the inaccessible welds. Section 3 discusses alternate flued head support designs that can drastically reduce flued head installation costs. Section 4 describes partial flued head replacement designs. Finally, Section 5 discusses flued head analysis methods. (orig./GL)

  12. Cluster Based Hierarchical Routing Protocol for Wireless Sensor Network

    OpenAIRE

    Rashed, Md. Golam; Kabir, M. Hasnat; Rahim, Muhammad Sajjadur; Ullah, Shaikh Enayet

    2012-01-01

    The efficient use of energy source in a sensor node is most desirable criteria for prolong the life time of wireless sensor network. In this paper, we propose a two layer hierarchical routing protocol called Cluster Based Hierarchical Routing Protocol (CBHRP). We introduce a new concept called head-set, consists of one active cluster head and some other associate cluster heads within a cluster. The head-set members are responsible for control and management of the network. Results show that t...

  13. In-flight calibration and performance evaluation of the fixed head star trackers for the solar maximum mission

    Science.gov (United States)

    Thompson, R. H.; Gambardella, P. J.

    1980-01-01

    The Solar Maximum Mission (SMM) spacecraft provides an excellent opportunity for evaluating attitude determination accuracies achievable with tracking instruments such as fixed head star trackers (FHSTs). As a part of its payload, SMM carries a highly accurate fine pointing Sun sensor (FPSS). The EPSS provides an independent check of the pitch and yaw parameters computed from observations of stars in the FHST field of view. A method to determine the alignment of the FHSTs relative to the FPSS using spacecraft data is applied. Two methods that were used to determine distortions in the 8 degree by 8 degree field of view of the FHSTs using spacecraft data are also presented. The attitude determination accuracy performance of the in flight calibrated FHSTs is evaluated.

  14. Goniometer head

    International Nuclear Information System (INIS)

    Dzhazairov-Kakhramanov, V.; Berger, V.D.; Kadyrzhanov, K.K.; Zarifov, R.A.

    1994-01-01

    The goniometer head is an electromechanical instrument that performs the independent transfer of a testing sample on three coordinate axes (X, Y, Z) within limits of ±8 mm and independent rotation relative of these directions. The instrument comprises a sample holder, bellows component and three electrometer drives. The sample holder rotates around the axes X and Y, and is installed on the central arm which rotates around axis Z. One characteristic of this instrument is its independence which allows its use in any camera for researches in the field of radiation physics. 2 figs

  15. Vitamin D Beliefs and Associations with Sunburns, Sun Exposure, and Sun Protection

    Science.gov (United States)

    Kim, Bang Hyun; Glanz, Karen; Nehl, Eric J.

    2012-01-01

    The main objective of this study was to examine certain beliefs about vitamin D and associations with sun exposure, sun protection behaviors, and sunburns. A total of 3,922 lifeguards, pool managers, and parents completed a survey in 2006 about beliefs regarding vitamin D and sun-related behaviors. Multivariate ordinal regression analyses and linear regression analysis were used to examine associations of beliefs and other variables. Results revealed that Non-Caucasian lifeguards and pool managers were less likely to agree that they needed to go out in the sun to get enough vitamin D. Lifeguards and parents who were non-Caucasian were less likely to report that sunlight helped the body to produce vitamin D. A stronger belief about the need to go out in the sun to get enough vitamin D predicted more sun exposure for lifeguards. For parents, a stronger belief that they can get enough vitamin D from foods predicted greater sun protection and a stronger belief that sunlight helps the body produce vitamin D predicted lower sun exposure. This study provides information regarding vitamin D beliefs and their association with certain sun related behaviors across different demographic groups that can inform education efforts about vitamin D and sun protection. PMID:22851950

  16. Sun Protection Practices and Sun Exposure among Children with a Parental History of Melanoma

    Science.gov (United States)

    Glenn, Beth A.; Lin, Tiffany; Chang, L. Cindy; Okada, Ashley; Wong, Weng Kee; Glanz, Karen; Bastani, Roshan

    2014-01-01

    Background First-degree relatives of melanoma survivors have a substantially higher lifetime risk for melanoma than individuals with no family history. Exposure to ultraviolet radiation is the primary modifiable risk factor for the disease. Reducing UV exposure through sun protection may be particularly important for children with a parental history of melanoma. Nonetheless, limited prior research has investigated sun protection practices and sun exposure among these children. Methods The California Cancer Registry was used to identify melanoma survivors eligible to participate in a survey to assess their children's sun protection practices and sun exposure. The survey was administered by mail, telephone, or web to Latino and non-Latino white melanoma survivors with at least one child (0–17 years; N = 324). Results Sun exposure was high and the rate of sunburn was equivalent to or higher than estimates from average risk populations. Use of sun protection was suboptimal. Latino children were less likely to wear sunscreen and hats and more likely to wear sunglasses, although these differences disappeared in adjusted analyses. Increasing age of the child was associated with lower sun protection and higher risk for sunburn whereas higher objective risk for melanoma predicted improved sun protection and a higher risk for sunburns. Perception of high barriers to sun protection was the strongest modifiable correlate of sun protection. Conclusions Interventions to improve sun protection and reduce sun exposure and sunburns in high risk children are needed. Impact Intervening in high risk populations may help reduce the burden of melanoma in the U.S. PMID:25587110

  17. Heading Estimation of Robot Combine Harvesters during Turning Maneuveres

    Directory of Open Access Journals (Sweden)

    Md Mostafizar Rahman

    2018-05-01

    Full Text Available Absolute heading is an important parameter for a robot combine harvester or a robot tracked combine harvester, especially while it is turning, but due to the rapid turning of robot combine harvesters, its inertial measurement unit gives a gyro measurement bias that causes heading drift. Our research goal is to estimate the absolute heading of robot combine harvesters by compensating this gyro measurement bias during non-linear turning maneuvers. A sensor fusion method like the extended Kalman filter combined with the tracked combine harvester dynamic model and sensor measurements was used to estimate the absolute heading of a robot combine harvester. Circular, sinusoidal and concave shapes were used to evaluate the estimated heading produced by the sensor fusion method. The results indicate that the estimated heading is better than measured heading which was calculated from the integration of yaw rate gyro measurements, and the root mean square errors (RMSEs for estimated headings are smaller than the measured headings. In practics, the target of this paper is thus the estimation of a heading or absolute heading that is bias compensated, and can be further used to calculate the exact crop periphery for automatic path planning of robot combine harvesters.

  18. Heading Estimation of Robot Combine Harvesters during Turning Maneuveres.

    Science.gov (United States)

    Rahman, Md Mostafizar; Ishii, Kazunobu

    2018-05-01

    Absolute heading is an important parameter for a robot combine harvester or a robot tracked combine harvester, especially while it is turning, but due to the rapid turning of robot combine harvesters, its inertial measurement unit gives a gyro measurement bias that causes heading drift. Our research goal is to estimate the absolute heading of robot combine harvesters by compensating this gyro measurement bias during non-linear turning maneuvers. A sensor fusion method like the extended Kalman filter combined with the tracked combine harvester dynamic model and sensor measurements was used to estimate the absolute heading of a robot combine harvester. Circular, sinusoidal and concave shapes were used to evaluate the estimated heading produced by the sensor fusion method. The results indicate that the estimated heading is better than measured heading which was calculated from the integration of yaw rate gyro measurements, and the root mean square errors (RMSEs) for estimated headings are smaller than the measured headings. In practics, the target of this paper is thus the estimation of a heading or absolute heading that is bias compensated, and can be further used to calculate the exact crop periphery for automatic path planning of robot combine harvesters.

  19. 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 ...

  20. The Sun's Mysteries from Space - I

    Indian Academy of Sciences (India)

    climate. Historically, it was the motion of the planets around the. Sun that .... concentrations of magnetic field, the convection is suppressed ... near-Earth space environments. ... Some of these reach our eyes and can be detected during the rare.

  1. 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...

  2. 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.

  3. 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 ...

  4. Summer weekend sun exposure and sunburn among a New Zealand urban population, 1994-2006.

    Science.gov (United States)

    McLeod, Geraldine Geri F H; Reeder, Anthony I; Gray, Andrew R; McGee, Rob

    2013-08-30

    To describe summer weekend sun exposure and sunburn experience, 1994-2006, among urban New Zealanders (15-69 years) by sex, age group, skin type and outdoor activity type. A series of five telephone surveys undertaken in the summers of 1994, 1997, 1999-2000, 2002-3 and 2005-6 provided a sample of 6,195 respondents with usable data from five major cities (Auckland, Hamilton, Wellington, Christchurch and Dunedin). Respondents were administered a Computer Assisted Telephone Interview (CATI) questionnaire which sought sociodemographic information, sun exposure, and sunburn experience during the most recent weekend. Overall, 69% of the sample had spent at least 15 minutes outdoors between 11am and 4pm. Weekend sunburn was reported by 21%, and was more common among males, young adults and those with highly sun-sensitive skin than females, older adults and those with less sensitive skin. The head/face/neck was the body area most frequently and severely sunburned. Sunburn was associated with greater time spent outdoors and occurred most frequently during water-based (29%) and passive recreational activities (25%) and paid work (23%). Sun protection strategies could usefully be targeted not only towards at-risk population groups, but also towards those activities and contexts most strongly associated with potentially harmful sun exposure.

  5. Sunburn, sun exposure, and sun sensitivity in the Study of Nevi in Children.

    Science.gov (United States)

    Satagopan, Jaya M; Oliveria, Susan A; Arora, Arshi; Marchetti, Michael A; Orlow, Irene; Dusza, Stephen W; Weinstock, Martin A; Scope, Alon; Geller, Alan C; Marghoob, Ashfaq A; Halpern, Allan C

    2015-11-01

    To examine the joint effect of sun exposure and sunburn on nevus counts (on the natural logarithm scale; log nevi) and the role of sun sensitivity. We describe an analysis of cross-sectional data from 443 children enrolled in the prospective Study of Nevi in Children. To evaluate the joint effect, we partitioned the sum of squares because of interaction between sunburn and sun exposure into orthogonal components representing (1) monotonic increase in log nevi with increasing sun exposure (rate of increase of log nevi depends on sunburn), and (2) nonmonotonic pattern. In unadjusted analyses, there was a marginally significant monotonic pattern of interaction (P = .08). In adjusted analyses, sun exposure was associated with higher log nevi among those without sunburn (P sunburn (P = .14). Sunburn was independently associated with log nevi (P = .02), even though sun sensitivity explained 29% (95% confidence interval: 2%-56%, P = .04) of its effect. Children with high sun sensitivity and sunburn had more nevi, regardless of sun exposure. A program of increasing sun protection in early childhood as a strategy for reducing nevi, when applied to the general population, may not equally benefit everyone. Copyright © 2015 Elsevier Inc. All rights reserved.

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

    International Nuclear Information System (INIS)

    Hechenblaikner, Gerald; Ziegler, Tobias

    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 the existing designs. (paper)

  7. Optimization method of star tracker orientation for sun-synchronous orbit based on space light distribution.

    Science.gov (United States)

    Wang, Geng; Xing, Fei; Wei, Minsong; Sun, Ting; You, Zheng

    2017-05-20

    Star trackers, optical attitude sensors with high precision, are susceptible to space light from the Sun and the Earth albedo. Until now, research in this field has lacked systematic analysis. In this paper, we propose an installation orientation method for a star tracker onboard sun-synchronous-orbit spacecraft and analyze the space light distribution by transforming the complicated relative motion among the Sun, Earth, and the satellite to the body coordinate system of the satellite. Meanwhile, the boundary-curve equations of the areas exposed to the stray light from the Sun and the Earth albedo were calculated by the coordinate-transformation matrix under different maneuver attitudes, and the installation orientation of the star tracker was optimized based on the boundary equations instead of the traditional iterative simulation method. The simulation and verification experiment indicate that this installation orientation method is effective and precise and can provide a reference for the installation of sun-synchronous orbit star trackers free from the stray light.

  8. Is HEADS in our heads?

    DEFF Research Database (Denmark)

    Boisen, Kirsten A; Hertz, Pernille Grarup; Blix, Charlotte

    2016-01-01

    contraception], Safety, Self-harm) interview is a feasible way of exploring health risk behaviors and resilience. OBJECTIVE: The purpose of this study was to evaluate how often HEADS topics were addressed according to young patients and staff in pediatric and adult outpatient clinics. METHODS: We conducted...... care professionals participated. We found only small reported differences between staff and young patients regarding whether home, education, and activity were addressed. However, staff reported twice the rate of addressing smoking, alcohol, illegal drugs, sexuality, and contraception compared to young...... patients. Young patients reported that smoking, alcohol, illegal drugs, sexuality, and contraception were addressed significantly more at adult clinics in comparison to pediatric clinics. After controlling for age, gender and duration of illness, according to young patients, adjusted odds ratios...

  9. Taste sensor; Mikaku sensor

    Energy Technology Data Exchange (ETDEWEB)

    Toko, K. [Kyushu University, Fukuoka (Japan)

    1998-03-05

    This paper introduces a taste sensor having a lipid/polymer membrane to work as a receptor of taste substances. The paper describes the following matters: this sensor uses a hollow polyvinyl chloride rod filled with KCl aqueous solution, and placed with silver and silver chloride wires, whose cross section is affixed with a lipid/polymer membrane as a lipid membrane electrode to identify taste from seven or eight kinds of response patterns of electric potential output from the lipid/polymer membrane; measurements of different substances presenting acidic taste, salty taste, bitter taste, sweet taste and flavor by using this sensor identified clearly each taste (similar response is shown to a similar taste even if the substances are different); different responses are indicated on different brands of beers; from the result of measuring a great variety of mineral waters, a possibility was suggested that this taste sensor could be used for water quality monitoring sensors; and application of this taste sensor may be expected as a maturation control sensor for Japanese sake (wine) and miso (bean paste) manufacturing. 2 figs., 1 tab.

  10. SunPy: Python for Solar Physics

    Science.gov (United States)

    Bobra, M.; Inglis, A. R.; Mumford, S.; Christe, S.; Freij, N.; Hewett, R.; Ireland, J.; Martinez Oliveros, J. C.; Reardon, K.; Savage, S. L.; Shih, A. Y.; Pérez-Suárez, D.

    2017-12-01

    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. SunPy aims to provide the software for obtaining and analyzing solar and heliospheric data. This poster introduces a new major release, SunPy version 0.8. The first major new feature introduced is Fido, the new primary interface to download data. It provides a consistent and powerful search interface to all major data providers including the VSO and the JSOC, as well as individual data sources such as GOES XRS time series. It is also easy to add new data sources as they become available, i.e. DKIST. The second major new feature is the SunPy coordinate framework. This provides a powerful way of representing coordinates, allowing simple and intuitive conversion between coordinate systems and viewpoints of different instruments (i.e., Solar Orbiter and the Parker Solar Probe), including transformation to astrophysical frames like ICRS. 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).

  11. 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...

  12. 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…

  13. 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…

  14. Guaranteeing Pointing Performance of the SDO Sun-Pointing Controllers in Light of Nonlinear Effects

    Science.gov (United States)

    Starin, Scott R.; Bourkland, Kristin L.

    2007-01-01

    The Solar Dynamics Observatory (SDO) mission is the first Space Weather Research Network mission, part of NASA s Living With a Star program.1 This program seeks to understand the changing Sun and its effects on the Solar System, life, and society. To this end, the SDO spacecraft will carry three Sun-observing instruments to geosynchronous orbit: Helioseismic and Magnetic Imager (HMI), led by Stanford University; Atmospheric Imaging Assembly (AIA), led by Lockheed Martin Space and Astrophysics Laboratory; and Extreme Ultraviolet Variability Experiment (EVE), led by the University of Colorado. Links describing the instruments in detail may be found through the SDO web site.2 The basic mission goals are to observe the Sun for a very high percentage of the 5-year mission (10-year goal) with long stretches of uninterrupted observations and with constant, high-data-rate transmission to a dedicated ground station. These goals guided the design of the spacecraft bus that will carry and service the three-instrument payload. At the time of this publication, the SDO spacecraft bus is well into the integration and testing phase at the NASA Goddard Space Flight Center (GSFC). A three-axis stabilized attitude control system (ACS) is needed both to point at the Sun accurately and to keep the roll about the Sun vector correctly positioned. The ACS has four reaction wheel modes and 2 thruster actuated modes. More details about the ACS in general and the control modes in particular can be found in Refs. [3-6]. All four of SDO s wheel-actuated control modes involve Sun-pointing controllers, as might be expected from such a mission. Science mode, during which most science data is collected, uses specialized guide telescopes to point accurately at the Sun. Inertial mode has two sub-modes, one tracks a Sun-referenced target orientation, and another maintains an absolute (star-referenced) target orientation, that both employ a Kalman filter to process data from a digital Sun sensor and

  15. 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

    ... DEPARTMENT OF TRANSPORTATION Office of the Secretary [Docket DOT-OST-2011-0169] Application of Sun Air Express, LLC, d/b/a Sun Air International for Commuter Authority AGENCY: Department of... order finding Sun Air Express, LLC d/b/a Sun Air International fit, willing, and able, and awarding it...

  16. 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...

  17. Convective penetration in a young sun

    Science.gov (United States)

    Pratt, Jane; Baraffe, Isabelle; Goffrey, Tom; MUSIC developers group

    2018-01-01

    To interpret the high-quality data produced from recent space-missions it is necessary to study convection under realistic stellar conditions. We describe the multi-dimensional, time implicit, fully compressible, hydrodynamic, implicit large eddy simulation code MUSIC. We use MUSIC to study convection during an early stage in the evolution of our sun where the convection zone covers approximately half of the solar radius. This model of the young sun possesses a realistic stratification in density, temperature, and luminosity. We approach convection in a stellar context using extreme value theory and derive a new model for convective penetration, targeted for one-dimensional stellar evolution calculations. This model provides a scenario that can explain the observed lithium abundance in the sun and in solar-like stars at a range of ages.

  18. Precise nuclear physics for the sun

    International Nuclear Information System (INIS)

    Bemmerer, Daniel

    2012-01-01

    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 populated areas

  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. Head Impact Laboratory (HIL)

    Data.gov (United States)

    Federal Laboratory Consortium — The HIL uses testing devices to evaluate vehicle interior energy attenuating (EA) technologies for mitigating head injuries resulting from head impacts during mine/...

  1. 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.

  2. Heating the Chromosphere in the Quiet Sun

    Science.gov (United States)

    Kohler, Susanna

    2018-04-01

    The best-studied star the Sun still harbors mysteries for scientists to puzzle over. A new study has now explored the role of tiny magnetic-field hiccups in an effort to explain the strangely high temperatures of the Suns upper atmosphere.Schematic illustrating the temperatures in different layers of the Sun. [ESA]Strange Temperature RiseSince the Suns energy is produced in its core, the temperature is hottest here. As expected, the temperature decreases further from the Suns core up until just above its surface, where it oddly begins to rise again. While the Suns surface is 6,000 K, the temperature is higher above this: 10,000 K in the outer chromosphere.So how is the chromosphere of the Sun heated? Its possible that the explanation can be found not amid high solar activity, but in quiet-Sun regions.In a new study led by Milan Goi (Lockheed Martin Solar and Astrophysics Laboratory, Bay Area Environmental Research Institute), a team of scientists has examined a process that quietly happens in the background: the cancellation of magnetic field lines in the quiet Sun.Activity in a SupergranuleTop left: SDO AIA image of part of the solar disk. The next three panels are a zoom of the particular quiet-Sun region that the authors studied, all taken with IRIS at varying wavelengths: 1400 (top right), 2796 (bottom left), and 2832 (bottom right). [Goi et al. 2018]The Sun is threaded by strong magnetic field lines that divide it into supergranules measuring 30 million meters across (more than double the diameter of Earth!). Supergranules may seem quiet inside, but looks can be deceiving: the interiors of supergranules contain smaller, transient internetwork fields that move about, often resulting in magnetic elements of opposite polarity encountering and canceling each other.For those internetwork flux cancellations that occur above the Suns surface, a small amount of energy could be released that locally heats the chromosphere. But though each individual event has a small

  3. 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

  4. 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

  5. Ultraviolet radiation, sun damage and preventing

    International Nuclear Information System (INIS)

    Johnsen, B.; Christensen, T.; Nilsen, L.T.; Hannevik, M.

    2013-01-01

    The report focuses on the large impact of health damages due to excessive UV exposure from natural sun. The first part of the report gives background information on factors significantly affecting the intensity of UV radiation. The second part gives an overview of health effects related to UV exposure, with recommendations on how to avoid excessive UV exposure and still enjoy the positive sides of outdoor activity. The report is intended to contribute to informational activities about sun exposure as recommended by the World Health Organisation and the World Meteorology Organisation. (Author)

  6. 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

  7. Visual perception of axes of head rotation

    Science.gov (United States)

    Arnoldussen, D. M.; Goossens, J.; van den Berg, A. V.

    2013-01-01

    Registration of ego-motion is important to accurately navigate through space. Movements of the head and eye relative to space are registered through the vestibular system and optical flow, respectively. Here, we address three questions concerning the visual registration of self-rotation. (1) Eye-in-head movements provide a link between the motion signals received by sensors in the moving eye and sensors in the moving head. How are these signals combined into an ego-rotation percept? We combined optic flow of simulated forward and rotational motion of the eye with different levels of eye-in-head rotation for a stationary head. We dissociated simulated gaze rotation and head rotation by different levels of eye-in-head pursuit. We found that perceived rotation matches simulated head- not gaze-rotation. This rejects a model for perceived self-rotation that relies on the rotation of the gaze line. Rather, eye-in-head signals serve to transform the optic flow's rotation information, that specifies rotation of the scene relative to the eye, into a rotation relative to the head. This suggests that transformed visual self-rotation signals may combine with vestibular signals. (2) Do transformed visual self-rotation signals reflect the arrangement of the semi-circular canals (SCC)? Previously, we found sub-regions within MST and V6+ that respond to the speed of the simulated head rotation. Here, we re-analyzed those Blood oxygenated level-dependent (BOLD) signals for the presence of a spatial dissociation related to the axes of visually simulated head rotation, such as have been found in sub-cortical regions of various animals. Contrary, we found a rather uniform BOLD response to simulated rotation along the three SCC axes. (3) We investigated if subject's sensitivity to the direction of the head rotation axis shows SCC axes specifcity. We found that sensitivity to head rotation is rather uniformly distributed, suggesting that in human cortex, visuo-vestibular integration is

  8. Visual perception of axes of head rotation

    Directory of Open Access Journals (Sweden)

    David Mattijs Arnoldussen

    2013-02-01

    Full Text Available Registration of ego-motion is important to accurately navigate through space. Movements of the head and eye relative to space are registered through the vestibular system and optical flow, respectively. Here, we address three questions concerning the visual registration of self-rotation. 1. Eye-in-head movements provide a link between the motion signals received by sensors in the moving eye and sensors in the moving head. How are these signals combined into an ego-rotation percept? We combined optic flow of simulated forward and rotational motion of the eye with different levels of eye-in-head rotation for a stationary head. We dissociated simulated gaze rotation and head rotation by different levels of eye-in-head pursuit.We found that perceived rotation matches simulated head- not gaze-rotation. This rejects a model for perceived self-rotation that relies on the rotation of the gaze line. Rather, eye-in-head signals serve to transform the optic flow’s rotation information, that specifies rotation of the scene relative to the eye, into a rotation relative to the head. This suggests that transformed visual self-rotation signals may combine with vestibular signals.2. Do transformed visual self-rotation signals reflect the arrangement of the semicircular canals (SCC? Previously, we found sub-regions within MST and V6+ that respond to the speed of the simulated head rotation. Here, we re-analyzed those BOLD signals for the presence of a spatial dissociation related to the axes of visually simulated head rotation, such as have been found in sub-cortical regions of various animals. Contrary, we found a rather uniform BOLD response to simulated rotation along the three SCC axes.3. We investigated if subject’s sensitivity to the direction of the head rotation axis shows SCC axes specifcity. We found that sensitivity to head rotation is rather uniformly distributed, suggesting that in human cortex, visuo-vestibular integration is not arranged into

  9. Heading and head injuries in soccer.

    Science.gov (United States)

    Kirkendall, D T; Jordan, S E; Garrett, W E

    2001-01-01

    In the world of sports, soccer is unique because of the purposeful use of the unprotected head for controlling and advancing the ball. This skill obviously places the player at risk of head injury and the game does carry some risk. Head injury can be a result of contact of the head with another head (or other body parts), ground, goal post, other unknown objects or even the ball. Such impacts can lead to contusions, fractures, eye injuries, concussions or even, in rare cases, death. Coaches, players, parents and physicians are rightly concerned about the risk of head injury in soccer. Current research shows that selected soccer players have some degree of cognitive dysfunction. It is important to determine the reasons behind such deficits. Purposeful heading has been blamed, but a closer look at the studies that focus on heading has revealed methodological concerns that question the validity of blaming purposeful heading of the ball. The player's history and age (did they play when the ball was leather and could absorb significant amounts of water), alcohol intake, drug intake, learning disabilities, concussion definition and control group use/composition are all factors that cloud the ability to blame purposeful heading. What does seem clear is that a player's history of concussive episodes is a more likely explanation for cognitive deficits. While it is likely that the subconcussive impact of purposeful heading is a doubtful factor in the noted deficits, it is unknown whether multiple subconcussive impacts might have some lingering effects. In addition, it is unknown whether the noted deficits have any affect on daily life. Proper instruction in the technique is critical because if the ball contacts an unprepared head (as in accidental head-ball contacts), the potential for serious injury is possible. To further our understanding of the relationship of heading, head injury and cognitive deficits, we need to: learn more about the actual impact of a ball on the

  10. A CMOS image sensor with row and column profiling means

    NARCIS (Netherlands)

    Xie, N.; Theuwissen, A.J.P.; Wang, X.; Leijtens, J.A.P.; Hakkesteegt, H.; Jansen, H.

    2008-01-01

    This paper describes the implementation and firstmeasurement results of a new way that obtains row and column profile data from a CMOS Image Sensor, which is developed for a micro-Digital Sun Sensor (μDSS).The basic profiling action is achieved by the pixels with p-type MOS transistors which realize

  11. Skin Cancer-Sun Knowledge and Sun Protection Behaviors of Liver Transplant Recipients in Turkey.

    Science.gov (United States)

    Haney, Meryem Ozturk; Ordin, Yaprak Sarigol; Arkan, Gulcihan

    2017-09-08

    The aim of this study was to compare liver transplant recipients (LTRs) with the general population regarding their knowledge of skin cancer, sun health, sun protection behaviors, and affecting factors. This cross-sectional study was conducted in Turkey between March 2016 and September 2016 with 104 LTRs and 100 participants from the general population group (GPG). The mean age of the LTRs was 53.2 ± 11.8 and that of the GPG was 42.7 ± 14.5. The LTRs' skin cancer and sun knowledge were significantly lower than in the GPG, but there was no difference between the two groups in terms of their sun protection behavior scores. The most commonly used sun protection behaviors of LTRs were not being outside and not sunbathing between 10 a.m. and 4 p.m., wearing clothing that covers the skin, and avoiding the solarium. Behaviors commonly practiced by the GPG were wearing sunglasses, wearing sunscreen with a sun protection factor of 15 or higher before going outside, wearing sunscreen at the beach, while swimming or doing physical activity outside, and reapplying it every 2 h. Results of our study will contribute to the development of education and training programs for LTRs on skin cancer. The results also demonstrated the importance of practicing adequate sun protection behaviors which will certainly impact their future health.

  12. 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.

  13. Save Beady Kid from the Sun

    Science.gov (United States)

    Demetrikopoulos, Melissa; Thompson, Wesley; Pecore, John

    2017-01-01

    Art and science help students investigate light energy and practice fair testing. With the goal of finding a way to save "Beady Kid" from invisible rays, students used science practices to investigate the transfer of light energy from the Sun. During this art-integrated science lesson presented in this article, upper elementary (grades…

  14. Neutrinos and our Sun - Part 2

    Indian Academy of Sciences (India)

    the sun during its lifetime of four and a half billion years is given by ... The balance between ... per unit time (the luminosity): ... are operative in all stars during the bulk of their life: (a) ..... Thus the data collected over several years of hard work.

  15. Helping Nevada School Children Become Sun Smart

    Centers for Disease Control (CDC) Podcasts

    This podcast features Christine Thompson, Community Programs Manager at the Nevada Cancer Coalition, and author of a recent study detailing a school-based program to help Nevada school children establish healthy sun safety habits and decrease UV exposure. Christine answers questions about her research and what impact her what impact the program had on children's skin health.

  16. A sun holiday is a sunburn holiday.

    Science.gov (United States)

    Petersen, Bibi; Thieden, Elisabeth; Philipsen, Peter Alshede; Heydenreich, Jakob; Young, Antony Richard; Wulf, Hans Christian

    2013-08-01

    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 by daily skin examinations by the same observer. Erythemally effective ultraviolet radiation (UVR) exposure was assessed with time-stamped personal dosimeters worn on the wrist. Volunteers reported their clothing cover and sunscreen use in diaries, and this information was used to determine body site-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 clearly support a substantial skin cancer risk from sun holidays. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  17. No smoking guns under the Sun

    CERN Document Server

    CERN. Geneva

    2000-01-01

    The Sun is a typical main sequence star that generates its energy via the fusion of hydrogen into helium in two chains of nuclear reactions: the so-called pp chain and the CNO chain. If the nucleon number, electric charge, lepton flavour and energy are conserved and the Sun is in a steady state, then the total solar neutrino flux is fixed, to a good approximation, by the solar luminosity (approximately 65 billion neutrinos/cm2/s at Earth), independent of the specific nuclear reactions that power the Sun and produce neutrinos by beta decay or the electron capture of reaction products. The neutrinos from the dominant pp chain are produced by the beta decay of proton pairs (pp), boron-8 and lithium-4, and by electron capture by pp pairs and beryllium-7. Their spectra can be measured directly in the laboratory or calculated from the standard theory of electroweak interactions. To a very good approximation, they are independent of the conditions in the Sun. Only their relative contributions depend on the detailed ...

  18. Self-calibrating solar position sensor

    Science.gov (United States)

    Maxey, Lonnie Curt

    2018-01-30

    A sun positioning sensor and method of accurately tracking the sun are disclosed. The sensor includes a position sensing diode and a disk having a body defining an aperture for accepting solar light. An extension tube having a body that defines a duct spaces the position sensing diode from the disk such that the solar light enters the aperture in the disk, travels through the duct in the extension tube and strikes the position sensing diode. The extension tube has a known length that is fixed. Voltage signals indicative of the location and intensity of the sun are generated by the position sensing diode. If it is determined that the intensity values are unreliable, then historical position values are used from a table. If the intensity values are deemed reliable, then actual position values are used from the position sensing diode.

  19. Head Trauma: First Aid

    Science.gov (United States)

    First aid Head trauma: First aid Head trauma: First aid By Mayo Clinic Staff Most head trauma involves injuries that are minor and don't require ... 21, 2015 Original article: http://www.mayoclinic.org/first-aid/first-aid-head-trauma/basics/ART-20056626 . Mayo ...

  20. The Sun among the stars. Pt. 3

    International Nuclear Information System (INIS)

    Hardorp, J.

    1980-01-01

    Energy distributions from 3308 to 8390 Angstroem of two candidates for a solar spectral analog and of 14 other northern G-type dwarfs are compared to the solar energy distribution via stellar spectrophotometric standards. The reliability of the stellar and solar flux-calibrations is evaluated. While the stellar calibration seems to be in good shape, solar calibrations differ widely. Labs.and Neckel's calibration is the best match to the energy distributions from 4500 to 8390 Angstroem of those four stars that share the Sun's ultraviolet line spectrum (16 Cyg B, G5V, and the three Hyades stars VB 64, 106, and 142). Below 4500 Angstroem, discrepancies of up to 6% remain which do not seem to be genuine Sun-star differences. An error in the Labs and Neckel tables between 5700 and 6000 Angstroem is corrected. The NASA Standard Tables of Solar Spectral Irradiance cannot be trusted, since there seems to be no star in the sky that look like the NASA-sun. The four stars mentioned are taken to be perfect solar spectral analogs. An improved table of solar spectral irradiance is then given by the magnitudes of 16 Cyg B minus 32.945, based on Tueg's atellar and Labs and Neckel's solar calibrations. The Sun's place in the UBV system is V = -26.71 +- 0.03, B-V = 0.665 +- 0.005, and U-B = 0.20 +- 0.01. Most previous photometric investigations found a bluer Sun because they used the wrong solar calibration. For deriving accurate albedos of planets, any one of the calibrated G-type stars can be used as a standard star, when corrections are applied, although the solar analogs themselves are to be preferred. The MK system of spectral classification should be revised. (orig.)

  1. Patients with acephalic spermatozoa syndrome linked to SUN5 mutations have a favorable pregnancy outcome from ICSI.

    Science.gov (United States)

    Fang, Jianzheng; Zhang, Jingjing; Zhu, Fuxi; Yang, Xiaoyu; Cui, Yugui; Liu, Jiayin

    2018-01-10

    Are Sad1 and UNC84 domain containing 5 (SUN5) mutations associated with the outcomes of ICSI in patients with acephalic spermatozoa syndrome (ASS)? Despite highly abnormal sperm morphology, ASS patients with SUN5 mutations have a favorable pregnancy outcome following ICSI. ASS is a rare cause of infertility characterized by the production of a majority of headless spermatozoa, along with a small proportion of intact spermatozoa with an abnormal head-tail junction. Previous studies have demonstrated that SUN5 mutations may cause ASS. Several studies showed that ICSI could help patients with ASS father children. This retrospective cohort study included 11 infertile ASS males with SUN5 mutations. Five of them underwent five ICSI cycles. Their ICSI results were compared to men with ASS without SUN5 mutations (n = 3) and to men with multiple morphological abnormalities of the sperm flagella (MMAF) (n = 9). All ICSI treatments were completed between Jan 2011 and May 2017. Sanger DNA sequencing was used to detect mutations in SUN5. Clinical and biological data were collected from patients at the fertility center. Sanger sequencing validated 11 patients with SUN5 mutations. Three novel mutations in SUN5 (c.829C>T [p.Q277*]; c.1067G>A [p.R356H]; c.211+1 insGT [p.S71Cfs11*]) were identified in three patients. The rates of fertilization, good-quality embryos and pregnancy for five patients with SUN5 mutations following ICSI were 81.5%, 81.8% and 100%, respectively. The rates of fertilization and good-quality embryos in patients with MMAF were significantly lower compared with ASS patients (65.6 versus 82.4%, P = 0.039 and 53.6 versus 85.2%, P = 0.031, respectively). There were no differences in ICSI results between ASS patients with and without SUN5 mutations. Only a small number patients with SUN5 mutations was available because of its rare incidence. Patients with ASS can be effectively treated with ICSI. SUN5 mutations may be one of the genetic causes of ASS. This study

  2. Head and neck cancer

    International Nuclear Information System (INIS)

    Vogl, S.E.

    1988-01-01

    This book contains 10 chapters. Some of the titles are: Combined Surgical Resection and Irradiation for Head and Neck Cancers; Analysis of Radiation Therapy Oncology Group Head and Neck Database: Identification of Prognostic Factors and the Re-evaluation of American Joint Committee Stages; Combined Modality Approach to Head and Neck Cancer; Induction Combination Chemotherapy of Regionally Advanced Head and Neck Cancer; and Outcome after Complete Remission to Induction Chemotherapy in Head and Neck Cancer

  3. Sun-Earth Scientists and Native Americans Collaborate on Sun-Earth Day

    Science.gov (United States)

    Ng, C. Y.; Lopez, R. E.; Hawkins, I.

    2004-12-01

    Sun-Earth Connection scientists have established partnerships with several minority professional societies to reach out to the blacks, Hispanics and Native American students. Working with NSBP, SACNAS, AISES and NSHP, SEC scientists were able to speak in their board meetings and national conferences, to network with minority scientists, and to engage them in Sun-Earth Day. Through these opportunities and programs, scientists have introduced NASA research results as well indigenous views of science. They also serve as role models in various communities. Since the theme for Sun-Earth Day 2005 is Ancient Observatories: Timeless Knowledge, scientists and education specialists are hopeful to excite many with diverse backgrounds. Sun-Earth Day is a highly visible annual program since 2001 that touches millions of students and the general public. Interviews, classroom activities and other education resources are available on the web at sunearthday.nasa.gov.

  4. Sun burn incidence and knowledge of greek elementary and high school children about sun protection.

    Science.gov (United States)

    Saridi, Maria Ioannis; Toska, Aikaterini George; Rekleiti, Maria Dimitrios; Tsironi, Maria; Geitona, Maria; Souliotis, Kyriakos

    2015-01-01

    Overexposure to sun radiation and particularly its accumulation during childhood and adolescence is a significant risk factor for skin cancer development. The sun burn is particularly important. To estimate sun burn incidence in young pupils in a coastal area of Greece. Two surveys were conducted in a school population in the same district in Greece, over different periods of time, in young people 9 to 18 years old (n=2 977). Anonymous questionnaires were completed. Levels of significance were two- tailed and statistical significance was set at p=0.05. SPSS 17.0 software was used for statistical analysis. From the individual characteristics of the participants it was shown that the majority of them had dark hair and fair skin, whereas a significant percentage reported the existence of moles on face and their body (83.4% vs 68.1%). The sun burn incidence was high in adolescents and the younger pupils (41.9% vs 55.6%). The younger aged children who were living in an urban area had significantly higher rates of sun burn than those living in semi-urban areas (33.8% vs 24.8%, p=0.020). As far as the knowledge of pupils about the risks of sun radiation it was shown that the elementary school pupils had better knowledge than those at high school. Finally, those with better knowledge had the fewer sun burns (Mean 2.83 SD 0.87, pknowledge to the decrease of sun burn incidence is important as long as this is continuous. Therefore, the education should concern not only children but also teachers and parents in the context of continuous and systematic programs of health education.

  5. 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.…

  6. 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

  7. Optical seismic sensor systems and methods

    Science.gov (United States)

    Beal, A. Craig; Cummings, Malcolm E.; Zavriyev, Anton; Christensen, Caleb A.; Lee, Keun

    2015-12-08

    Disclosed is an optical seismic sensor system for measuring seismic events in a geological formation, including a surface unit for generating and processing an optical signal, and a sensor device optically connected to the surface unit for receiving the optical signal over an optical conduit. The sensor device includes at least one sensor head for sensing a seismic disturbance from at least one direction during a deployment of the sensor device within a borehole of the geological formation. The sensor head includes a frame and a reference mass attached to the frame via at least one flexure, such that movement of the reference mass relative to the frame is constrained to a single predetermined path.

  8. Child sun protection: sun-related attitudes mediate the association between children's knowledge and behaviours.

    Science.gov (United States)

    Wright, Caradee; Reeder, Anthony I; Gray, Andrew; Cox, Brian

    2008-12-01

    To describe and investigate the relationship among the sun-related knowledge, attitudes and behaviours of New Zealand primary schoolchildren and consider the roles of sex and school year level. A randomly selected, two-stage cluster sample of 488 children from 27 primary schools in five regions of New Zealand was surveyed regarding their sun-related knowledge, attitudes and behaviours. A scoring system was used to assign a knowledge, attitude and behaviour score to each child. Although knowledge increased with school year level, there was a decline in sun protective attitudes and behaviours. There was little variation in knowledge, attitudes and behaviour between boys and girls, but sex-year level interactions were found for knowledge and behaviour. When considering children's knowledge, attitudes and behaviours simultaneously, knowledge was only significantly associated with behaviours when mediated by attitudes. When targeting child sun protection and skin cancer prevention programmes, a focus on attitudes towards sun exposure and a suntan may prove beneficial in influencing sun-related behaviours.

  9. Sun exposure and sun protection behaviours among young adult sport competitors.

    Science.gov (United States)

    Lawler, Sheleigh; Spathonis, Kym; Eakin, Elizabeth; Gallois, Cindy; Leslie, Eva; Owen, Neville

    2007-06-01

    To explore the relationship between sun protection and physical activity in young adults (18-30 years) involved in four organised sports. Participants (n=237) in field hockey, soccer, tennis and surf sports completed a self-administered survey on demographic and sun-protective behaviours while playing sport. Differences in sun-protective behaviour were explored by sport and by gender. Sunburn during the previous sporting season was high (69%). There were differences between sports for sunburn, sunscreen use and reapplication of sunscreen. Lifesaving had the highest rates compared with the other three sports. Hats and sunglasses worn by participants varied significantly by sports. A greater proportion of soccer and hockey players indicated they were not allowed to wear a hat or sunglasses during competition. For all sports, competition was played mainly in the open with no shade provision for competitors while they were playing. There were some gender differences within each of the sports. Female soccer and tennis players were more likely to wear sunscreen compared with males. Female hockey players were more likely to wear a hat compared with males. Our findings highlight that there is still room for improvement in sun-protective behaviours among young adult sport competitors. There is a need for a systematic approach to sun protection in the sporting environments of young adults. Health promotion efforts to increase physical activity need to be paired with sun protection messages.

  10. Ambient Sensors

    NARCIS (Netherlands)

    Börner, Dirk; Specht, Marcus

    2014-01-01

    This software sketches comprise two custom-built ambient sensors, i.e. a noise and a movement sensor. Both sensors measure an ambient value and process the values to a color gradient (green > yellow > red). The sensors were built using the Processing 1.5.1 development environment. Available under

  11. Topology Optimisation of Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Thike Aye Min

    2016-01-01

    Full Text Available Wireless sensor networks are widely used in a variety of fields including industrial environments. In case of a clustered network the location of cluster head affects the reliability of the network operation. Finding of the optimum location of the cluster head, therefore, is critical for the design of a network. This paper discusses the optimisation approach, based on the brute force algorithm, in the context of topology optimisation of a cluster structure centralised wireless sensor network. Two examples are given to verify the approach that demonstrate the implementation of the brute force algorithm to find an optimum location of the cluster head.

  12. Time-domain fiber loop ringdown sensor and sensor network

    Science.gov (United States)

    Kaya, Malik

    Optical fibers have been mostly used in fiber optic communications, imaging optics, sensing technology, etc. Fiber optic sensors have gained increasing attention for scientific and structural health monitoring (SHM) applications. In this study, fiber loop ringdown (FLRD) sensors were fabricated for scientific, SHM, and sensor networking applications. FLRD biosensors were fabricated for both bulk refractive index (RI)- and surface RI-based DNA sensing and one type of bacteria sensing. Furthermore, the effect of glucose oxidase (GOD) immobilization at the sensor head on sensor performance was evaluated for both glucose and synthetic urine solutions with glucose concentration between 0.1% and 10%. Detection sensitivities of the glucose sensors were achieved as low as 0.05%. For chemical sensing, heavy water, ranging from 97% to 10%, and several elemental solutions were monitored by using the FLRD chemical sensors. Bulk index-based FLRD sensing showed that trace elements can be detected in deionized water. For physical sensing, water and cracking sensors were fabricated and embedded into concrete. A partially-etched single-mode fiber (SMF) was embedded into a concrete bar for water monitoring while a bare SMF without any treatment was directly embedded into another concrete bar for monitoring cracks. Furthermore, detection sensitivities of water and crack sensors were investigated as 10 ml water and 0.5 mm surface crack width, respectively. Additionally fiber loop ringdown-fiber Bragg grating temperature sensors were developed in the laboratory; two sensor units for water, crack, and temperature sensing were deployed into a concrete cube in a US Department of Energy test bed (Miami, FL). Multi-sensor applications in a real concrete structure were accomplished by testing the six FLRD sensors. As a final stage, a sensor network was assembled by multiplexing two or three FLRD sensors in series and parallel. Additionally, two FLRD sensors were combined in series and

  13. 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.

  14. Conception and realization of a PV system provided with a sun tracker operating at dual axis

    Directory of Open Access Journals (Sweden)

    Khalil Kassmi

    2016-06-01

    Full Text Available In this paper, we present the conception, the realization and the experimentation of  a photovoltaic (PV system provided with a sun tracker reliable and low cost operating at dual axis. The tracker's role is to orient the PV generator, whose weight may reach 9 Kg, perpendicular to the sun with very good accuracy. This tracking  based on the use of four LDR sensors, which detect the intensity of light scattered by the sun a processing unit, from  command and control (UTCC, which manages all of the sun tracking tasks (the end detection of parcours, regulation of the power supplied by the PV panels (Command MPPT, ... . The results obtained show a significant improvement of the energy produced, compared to conventional PV installations where generators are fixed and oriented south at a  tilt 45°. During a day of operation, improvement could reach 41% and consumption of the tracking does not exceed 0.55% of the energy production produced by the PV generator (an improvement of 5 % compared to existing trackers.

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

    International Nuclear Information System (INIS)

    Blennow, Mattias; Edsjö, Joakim; Ohlsson, Tommy

    2011-01-01

    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.

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

    International Nuclear Information System (INIS)

    Blennow, Mattias; Edsjoe, Joakim; Ohlsson, Tommy

    2006-01-01

    The prospects for detecting 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

  17. Embedding Sensors During Additive Manufacturing

    Energy Technology Data Exchange (ETDEWEB)

    Sbriglia, Lexey Raylene [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-08-10

    This PowerPoint presentation had the following headings: Fused deposition modeling (FDM); Open source 3D printing; Objectives; Vibration analysis; Equipment; Design; Material choices; Failure causes, such as tension, bubbling; Potential solutions; Simulations; Embedding the sensors; LabView programming; Alternate data acquisition; Problem and proposed solution; and, Conclusions

  18. Pharmaceutical Pill Counting and Inspection Using a Capacitive Sensor

    Directory of Open Access Journals (Sweden)

    Ganesan LETCHUMANAN

    2008-01-01

    Full Text Available A capacitive sensor for high-speed counting and inspection of pharmaceutical products is proposed and evaluated. The sensor is based on a patented Electrostatic Field Sensor (EFS device, previously developed by Sparc Systems Limited. However, the sensor head proposed in this work has a significantly different geometry and has been designed with a rectangular inspection aperture of 160mm × 21mm, which best meets applications where a larger count throughput is required with a single sensor. Finite element modelling has been used to simulate the electrostatic fields generated within the sensor, and as a design tool for optimising the sensor head configuration. The actual and simulated performance of the sensor is compared and analysed in terms of the sensor performance at discriminating between damaged products or detection of miscount errors.

  19. Putting the sun to work in Sacramento

    International Nuclear Information System (INIS)

    Osborn, D.E.

    2000-01-01

    At dawn this morning, the sun went to work for customers of the Sacramento Municipal Utility District (SMUD). The largest photovoltaic (PV) power plant in the world, adjacent to the closed nuclear power plant at Rancho Seco, generated enough electricity for over a thousand customers, rooftop solar water heaters lowered thousands of residential electric bills and rooftop PV systems turned hundreds of Sacramento homes into mini power plants. SMUD, in partnership with their customers-owners, is leading the way in putting the sun to work today. SMUD plans to have at least half of its energy come from energy efficiency, existing hydroelectric plants and renewable resources in this decade. SMUD expects investments made in solar power today to provide its customer-owners with substantial long-term energy, environmental and community benefits. This article describes some of SMUD's efforts

  20. PROPERTIES OF NEAR-SUN ASTEROIDS

    Energy Technology Data Exchange (ETDEWEB)

    Jewitt, David, E-mail: jewitt@ucla.edu [Department of Earth and Space Sciences and Department of Physics and Astronomy, University of California at Los Angeles, 595 Charles Young Drive East, Los Angeles, CA 90095-1567 (United States)

    2013-05-15

    Asteroids near the Sun can attain equilibrium temperatures sufficient to induce surface modification from thermal fracture, desiccation, and decomposition of hydrated silicates. We present optical observations of nine asteroids with perihelia <0.25 AU (sub-solar temperatures {>=}800 K) taken to search for evidence of thermal modification. We find that the broadband colors of these objects are diverse but statistically indistinguishable from those of planet-crossing asteroids having perihelia near 1 AU. Furthermore, images of these bodies taken away from perihelion show no evidence for on-going mass-loss (model-dependent limits {approx}<1 kg s{sup -1}) that might result from thermal disintegration of the surface. We conclude that, while thermal modification may be an important process in the decay of near-Sun asteroids and in the production of debris, our new data provide no evidence for it.

  1. 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)

  2. 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.

  3. The apparent motion of the Sun revisited

    Science.gov (United States)

    Probst, Oliver

    2002-05-01

    The knowledge of the apparent motion of the Sun - due to the combined effects of the rotation of the Earth around its proper axis and the translation around the Sun - is important both in natural and man-made systems. In particular, a proper explanation of the seasons requires an understanding of this solar geometry. In this paper we present a simple derivation of the relevant formulae based on vector algebra. The possible trajectories are discussed in detail. An approximate explicit formula for the seasonal variations of solar radiation is derived and discussed. The calculations give useful insights into the geometry of the problem and are thought to be helpful for the undergraduate teaching of solar energy engineering, classical mechanics and astronomy.

  4. 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".

  5. Sun Protection; A risk management approach

    Science.gov (United States)

    Diffey, Brian

    2017-10-01

    Sun Protection differentiates itself from other texts by adopting a risk-management approach to determine whether, how, and in what circumstances, harm might be caused, and to explore the feasibility of various strategies in controlling exposure to solar UV radiation. This multi-disciplinary book covers topics from climatology through human exposure to sunlight, as well as biological and clinical effects of UV radiation to physical and chemical strategies for photoprotection.

  6. Counseling on Sun Protection and Indoor Tanning.

    Science.gov (United States)

    Balk, Sophie J; Gottschlich, Elizabeth A; Holman, Dawn M; Watson, Meg

    2017-12-01

    The US Preventive Services Task Force recommends clinical counseling for individuals ages 10 to 24 years to decrease skin cancer risk. A national, random sample of US American Academy of Pediatrics members practicing primary care in 2002 (response rate 55%) and 2015 (response rate 43%). Surveys explored attitudes and experiences regarding sun protection counseling; indoor tanning questions were added in 2015. χ 2 tests compared demographics and counseling responses across years, and multivariable logistic regression models examined counseling predictors. More pediatricians in 2015 (34%) than in 2002 (23%) reported discussing sun protection during recent summer months with ≥75% of patients. This pattern held across all patient age groups (each P tanning at least once with 10 to 13 year-old patients; approximately half discussed this with older adolescents. Most (70%) did not know if their states had laws on minors' indoor tanning access; those stating they knew whether a law existed counseled more. Although improved, sun protection counseling rates remain low. Indoor tanning counseling can be improved. Because early-life exposure to UV radiation increases risk and clinician counseling can positively impact prevention behaviors, pediatricians have an important role in skin cancer prevention; counseling may save lives. Time constraints remain a barrier. Copyright © 2017 by the American Academy of Pediatrics.

  7. The structure and evolution of the Sun

    CERN Document Server

    Severino, Giuseppe

    2017-01-01

    This book equips the reader with a coherent understanding of the structure of the Sun and its evolution and provides all the knowledge required to construct a simplified model of the Sun. The early chapters cover key aspects of basic physics and describe the Sun’s size, mass, luminosity, and temperature. Using a semi-empirical approach, the structure of the present Sun is then modeled in detail, layer by layer, proceeding from the photosphere to the convection zone, radiation zone, and core. Finally, all stages of the Sun’s evolution, from its formation to the end of its life, are carefully explained. The book is primarily intended for university students taking the initial steps in moving from physics to astrophysics. It includes worked exercises and problems to illustrate the concepts discussed, as well as additional problems for independent study. With the aim of helping the reader as much as possible, most of the mathematics required to use the book are provided in the text.

  8. Escape of magnetic toroids from the Sun

    International Nuclear Information System (INIS)

    Bieber, John W.; Rust, David M.

    1996-01-01

    Analysis of heliospheric magnetic fields at 1 AU shows that 10 24 Mx of net toroidal flux escapes from the Sun per solar cycle. This rate is compared with the apparent rate of flux emergence at the solar surface, and it is concluded that escaping toroids will remove at least 20% of the emerging flux, and may remove as much as 100% of emerging flux if multiple eruptions occur on the toroids. The data imply that flux escapes the Sun with an efficiency far exceeding Parker's upper limit estimate of 3%. Toroidal flux escape is almost certainly the source of the observed overwinding of the interplanetary magnetic field spiral. Two mechanisms to facilitate net flux escape are discussed: helicity charging to push open the fields and flux transport with reconnection to close them off. We estimate the Sun will shed ∼2x10 45 Mx 2 of magnetic helicity per solar cycle, leading to a mean helicity density of 100 Mx 2 cm -3 at 1 AU, which agrees well with observations

  9. Learning about the Dynamic Sun through Sounds

    Science.gov (United States)

    Quinn, M.; Peticolas, L. M.; Luhmann, J.; MacCallum, J.

    2008-06-01

    Can we hear the Sun or its solar wind? Not in the sense that they make sound. But we can take the particle, magnetic field, electric field, and image data and turn it into sound to demonstrate what the data tells us. We present work on turning data from the two-satellite NASA mission called STEREO (Solar TErrestrial RElations Observatory) into sounds and music (sonification). STEREO has two satellites orbiting the Sun near Earth's orbit to study the coronal mass ejections (CMEs) from the Corona. One sonification project aims to inspire musicians, museum patrons, and the public to learn more about CMEs by downloading STEREO data and using it to make music. We demonstrate the software and discuss the way in which it was developed. A second project aims to produce a museum exhibit using STEREO imagery and sounds from STEREO data. We demonstrate a "walk across the Sun" created for this exhibit so people can hear the features on solar images. We show how pixel intensity translates into pitches from selectable scales with selectable musical scale size and octave locations. We also share our successes and lessons learned.

  10. 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.

  11. Protective clothing in the sun | Tamas | Nigerian Journal of Clinical ...

    African Journals Online (AJOL)

    Sun protecting clothing is clothing designed for sun protection and is producted from the fabric rated for its level ultraviolet (UV) protection. Some textiles and fabrics emloyed in the use of sun protective clothing may be pre-treated with UV inhibiting ingredients during manufacture to enhance their UV blocking capacitiy.

  12. Keeping Cool Close to the Sun

    International Nuclear Information System (INIS)

    Hazi, A

    2006-01-01

    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

  13. A practical equation of state for the sun and sun-like stars

    International Nuclear Information System (INIS)

    Lin, H.H.; Daeppen, W.

    2012-01-01

    For models of the Sun and Sun-like stars, a high-quality equation of state is crucial. Conversely, helio- and asteroseismological observations put constraints on the physical formalisms. They effectively turn the Sun and stars into laboratories for dense plasmas. For models of the Sun and Sun-like stars, the most accurate equation of state so far has been the one developed as part of OPAL opacity project of Livermore. However, the OPAL equation of state is limited in two important respects. First, it is only available in the form of pre-computed tables that are provided from Lawrence Livermore National Laboratory. Applications to stellar modeling require therefore interpolation, with unavoidable loss of accuracy. Second, the OPAL equation of state is proprietary and not freely available. Varying its underlying physical parameters is therefore no option for the community. We report on the most recent progress with the development of a high-precision emulation of the OPAL equation of state that will lead to an in-line tool for modelers (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  14. 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.

  15. Head injury - first aid

    Science.gov (United States)

    ... medlineplus.gov/ency/article/000028.htm Head injury - first aid To use the sharing features on this page, ... a concussion can range from mild to severe. First Aid Learning to recognize a serious head injury and ...

  16. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... the head uses special x-ray equipment to help assess head injuries, severe headaches, dizziness, and other ... aneurysm, bleeding, stroke and brain tumors. It also helps your doctor to evaluate your face, sinuses, and ...

  17. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... for Brain Tumors Radiation Therapy for Head and Neck Cancer Others American Stroke Association National Stroke Association ... Computer Tomography (CT) Safety During Pregnancy Head and Neck Cancer X-ray, Interventional Radiology and Nuclear Medicine ...

  18. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... When the image slices are reassembled by computer software, the result is a very detailed multidimensional view ... Safety Images related to Computed Tomography (CT) - Head Videos related to Computed Tomography (CT) - Head Sponsored by ...

  19. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... the limitations of CT Scanning of the Head? What is CT Scanning of the Head? Computed tomography, ... than regular radiographs (x-rays). top of page What are some common uses of the procedure? CT ...

  20. Sun exposure and protection behavior of Danish farm children

    DEFF Research Database (Denmark)

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

    2014-01-01

    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...

  1. Revelation of the Sun Self-Similarity Skeletal Structures

    International Nuclear Information System (INIS)

    Rantsev-Kartinov, V.A.

    2005-01-01

    The analysis of databases of photographic images of a surface of the Sun, its atmosphere and the closest its space environment taken at various spatial resolutions and for various types of radiation of a surface of the Sun by means of a method multilevel dynamic contrasting, has revealed presence skeletal structures as on the Sun directly such and in its environment. It is demonstrated the revealed a global structures of the Sun and powerful ejections of mass of its corona, as well as the structures of its atmosphere, protuberances, sun-spots and a globular structures of its photosphere

  2. Three-dimensional display of femoral head cartilage thickness maps from MR images

    International Nuclear Information System (INIS)

    Rubin, R.A.; Dolecki, M.; Rubash, H.E.; Thaete, F.L.; Hernden, J.H.

    1990-01-01

    This paper reports on the development of methods for three-dimensional display and analysis of the articular cartilage of the hip from MR images. Cadaveric femoral head specimens were images with three-dimensional GRASS MR imaging. Data were analyzed on a SUN workstation with original software, the ANALYZE package from Richard Robb's Biomedical Research Group at the Mayo Clinic, and SUN's Voxvu program. The articular cartilage was isolated by manually segmenting images. An original computer ray tracing method measured the cartilage thickness radially and produced movies of a rotating femoral head, displaying brightness proportional to cartilage thickness

  3. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... Physician Resources Professions Site Index A-Z Computed Tomography (CT) - Head Computed tomography (CT) of the head uses special x-ray ... What is CT Scanning of the Head? Computed tomography, more commonly known as a CT or CAT ...

  4. Classifying Sensors Depending on their IDs to Reduce Power Consumption in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Ayman Mohammd Brisha

    2010-05-01

    Full Text Available Wireless sensor networks produce a large amount of data that needs to be processed, delivered, and assessed according to the application objectives. Cluster-based is an effective architecture for data-gathering in wireless sensor networks. Clustering provides an effective way for prolonging the lifetime of a wireless sensor network. Current clustering algorithms usually utilize two techniques, selecting cluster heads with more residual energy and rotating cluster heads periodically, in order to distribute the energy consumption among nodes in each cluster and extend the network lifetime. Clustering sensors are divided into groups, so that sensors will communicate information only to cluster heads and then the cluster heads will communicate the aggregated information to the processing center, and this may save energy. In this paper we show Two Relay Sensor Algorithm (TRSA, which divide wireless Sensor Network (WSN into unequaled clusters, showing that it can effectively save power for maximizing the life time of the network. Simulation results show that the proposed unequal clustering mechanism (TRSA balances the energy consumption among all sensor nodes and achieves an obvious improvement on the network lifetime.

  5. Evaluation of First Class and End Class of Medical Students’ Knowledge and Behaviors About the Sun and the Skin

    Directory of Open Access Journals (Sweden)

    Pınar Özuğuz

    2014-03-01

    Full Text Available Objective: We aimed to investigate knowledge and attitude of the first-year and finalyear medical students about ultraviolet (UV light, effects of UV on skin, skin cancers and sunscreens, and to evaluate whether awareness on these subjects were gained during the medical education. Methods: First-year and final-year medical students were asked to complete our questionnaire consisting of 20 questions which were about demographic data of the students and which were intended to assess their knowledge about sun, skin cancers and sun screenings. All the data are analyzed by SPSS20 software. Statistical significance level was set at p<0.05. Results: Of the 120 students, 64 (53.33% were males and 56 (46.66% were females. Of the 120 first-year medical students 78 (65% completed the questionnaire, while 42 (54% among 78 final-year medical students completed the questionnaire. The ratios of answering 3 of the 8 questions about ultraviolet, 3 of the 6 questions about sunscreens and 1 of the 3 questions about UV and skin cancer correctly were significantly higher in final-year students as compared to those in first year students (p≤0.001. Conclusion: During medical education, the awareness of students about issues regarding sun and skin and effective protection from sun is not adequate. Discussing this subject under the heading of sun and skin during the dermatology education program may reduce the lack of awareness on this subject.

  6. Associations between authoritative parenting and the sun exposure and sun protective behaviours of adolescents and their friends.

    Science.gov (United States)

    Mewse, Avril J; Lea, Stephen E G; Ntala, Eleni; Eiser, J Richard

    2011-05-01

    Associations between the sun exposure and sun protective behaviours of adolescents and their friends were examined along with the role played by authoritative parenting and other family and peer socialisation factors. Four hundred and two adolescents (198 males, 204 females) participated in the research. It was found that these adolescents and their friends shared similar sun exposure and sun protective behaviours and had similar parenting backgrounds. Parental authoritativeness was positively associated with the use of sun protection, even after the effects of other familial and peer variables were controlled, but not with the time spent sunbathing which was associated with friends' behaviours. The theoretical and practical implications of these findings are discussed.

  7. Moon and sun shadowing effect measurements

    International Nuclear Information System (INIS)

    Medeiros, Michelle Mesquita de; Gomes, Ricardo Avelino

    2011-01-01

    Full text: The deficit due to the absorption of cosmic rays by the Moon and the Sun can be observed detecting the muon flux generated in extensive air showers. This phenomenon, known as cosmic ray shadow, can be used to study the behaviour of the geomagnetic, solar and interplanetary magnetic fields, to measure the antiproton-proton ratio and to determine the angular resolution and alignment of the detectors to confirm its accuracy and precision. Many experiments using surface or underground detectors have measured the Moon and Sun shadow: MINOS, CYGNUS, CASA, Tibet, MACRO, Soudan2, L3+C, Milagro, BUST, GRAPE and HEGRA. The MINOS experiment (Main Injector Neutrino Oscillation Search) uses two layered steel and plastic scintillator detectors (Near Detector and Far Detector) along with a muon neutrino beam (NuMI - Neutrinos at the Main Injector) to search for ν μ disappearance, and thus neutrino oscillations. However the magnetic field and the fiducial volume of the underground Far Detector at Soudan Underground Mine State Park (Minnesota, USA) allow a great opportunity to investigate cosmic rays at TeV surface energy. The deficit caused by the Moon and the Sun was detected by the MINOS Far Detector and this could also be done using the Near Detector. In this report we describe the motivation of measuring this effect. We present the recent results from MINOS along with its experimental apparatus and, in addition, the main results from the various experiments. We also make considerations about the possibility of doing such a measurement with the MINOS Near Detector. (author)

  8. 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.

  9. Helping Nevada School Children Become Sun Smart

    Centers for Disease Control (CDC) Podcasts

    2017-11-28

    This podcast features Christine Thompson, Community Programs Manager at the Nevada Cancer Coalition, and author of a recent study detailing a school-based program to help Nevada school children establish healthy sun safety habits and decrease UV exposure. Christine answers questions about her research and what impact her what impact the program had on children’s skin health.  Created: 11/28/2017 by Preventing Chronic Disease (PCD), National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP).   Date Released: 11/28/2017.

  10. 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

  11. 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...... formation on galactic scales. A `dark baryon' of mass 5 GeV is a natural candidate and has the required relic abundance if its asymmetry is similar to that of ordinary baryons. We show that such particles can solve the `solar composition problem'. The predicted small decrease in the low energy neutrino...

  12. Investigation of possible sun-weather relationships

    International Nuclear Information System (INIS)

    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

  13. Occupational sun exposure and mycosis fungoides

    DEFF Research Database (Denmark)

    Morales-Suárez-Varela, Maria M.; Olsen, Jorn; Johansen, Preben

    2006-01-01

    OBJECTIVE: We sought to study the association between occupational sun exposure and mycosis fungoides (MF), a peripheral T-cell lymphoma. SUBJECTS and METHODS: A European multicenter case-control study including seven rare cases (one being MF) was conducted between 1995 and 1997. From the 118...... accepted cases, 104 were interviewed, of which 76 were definite cases. Population controls were selected randomly from the regions of case ascertainment. Information based on occupational experiences was coded according to industry types. A job exposure matrix was created according to the expected exposure...

  14. Attention Sensor

    NARCIS (Netherlands)

    Börner, Dirk; Kalz, Marco; Specht, Marcus

    2014-01-01

    This software sketch was used in the context of an experiment for the PhD project “Ambient Learning Displays”. The sketch comprises a custom-built attention sensor. The sensor measured (during the experiment) whether a participant looked at and thus attended a public display. The sensor was built

  15. Study of Λ parameters and crossover phenomena in SU(N) x SU(N) sigma models in two dimensions

    International Nuclear Information System (INIS)

    Shigemitsu, J.; Kogut, J.B.

    1981-01-01

    The spin system analogues of recent studies of the string tension and Λ parameters of SU(N) gauge theories in 4 dimensions are carried out for the SU(N) x SU(N) and O(N) models in 2 dimensions. The relations between the Λ parameters of both the Euclidean and Hamiltonian formulation of the lattice models and the Λ parameter of the continuum models are obtained. The one loop finite renormalization of the speed of light in the lattice Hamiltonian formulations of the O(N) and SU(N) x SU(N) models is calculated. Strong coupling calculations of the mass gaps of these spin models are done for all N and the constants of proportionality between the gap and the Λ parameter of the continuum models are obtained. These results are contrasted with similar calculations for the SU(N) gauge models in 3+1 dimensions. Identifying suitable coupling constants for discussing the N → infinity limits, the numerical results suggest that the crossover from weak to strong coupling in the lattice O(N) models becomes less abrupt as N increases while the crossover for the SU(N) x SU(N) models becomes more abrupt. The crossover in SU(N) gauge theories also becomes more abrupt with increasing N, however, at an even greater rate than in the SU(N) x SU(N) spin models

  16. Head, Neck, and Oral Cancer

    Medline Plus

    Full Text Available ... Head and Neck Pathology Oral, Head and Neck Pathology Close to 49,750 Americans will be diagnosed ... Head and Neck Pathology Oral, Head and Neck Pathology Close to 49,750 Americans will be diagnosed ...

  17. Head-Impact–Measurement Devices: A Systematic Review

    Science.gov (United States)

    O'Connor, Kathryn L.; Rowson, Steven; Duma, Stefan M.; Broglio, Steven P.

    2017-01-01

    Context: With an estimated 3.8 million sport- and recreation-related concussions occurring annually, targeted prevention and diagnostic methods are needed. Biomechanical analysis of head impacts may provide quantitative information that can inform both prevention and diagnostic strategies. Objective: To assess available head-impact devices and their clinical utility. Data Sources: We performed a systematic search of the electronic database PubMed for peer-reviewed publications, using the following phrases: accelerometer and concussion, head impact telemetry, head impacts and concussion and sensor, head impacts and sensor, impact sensor and concussion, linear acceleration and concussion, rotational acceleration and concussion, and xpatch concussion. In addition to the literature review, a Google search for head impact monitor and concussion monitor yielded 15 more devices. Study Selection: Included studies were performed in vivo, used commercially available devices, and focused on sport-related concussion. Data Extraction: One author reviewed the title and abstract of each study for inclusion and exclusion criteria and then reviewed each full-text article to confirm inclusion criteria. Controversial articles were reviewed by all authors to reach consensus. Data Synthesis: In total, 61 peer-reviewed articles involving 4 head-impact devices were included. Participants in boxing, football, ice hockey, soccer, or snow sports ranged in age from 6 to 24 years; 18% (n = 11) of the studies included female athletes. The Head Impact Telemetry System was the most widely used device (n = 53). Fourteen additional commercially available devices were presented. Conclusions: Measurements collected by impact monitors provided real-time data to estimate player exposure but did not have the requisite sensitivity to concussion. Proper interpretation of previously reported head-impact kinematics across age, sport, and position may inform future research and enable staff clinicians

  18. Lifestyle, sun worshipping and sun tanning - what about UV-A sun beds. Livsstil, soling og bruning - hva med UV-A solarier

    Energy Technology Data Exchange (ETDEWEB)

    Thune, P. (Ullevaal Sykehus, Oslo (Norway))

    1991-06-01

    This article considers the effects of ultraviolet (UV) light from the sun and UV-A sun beds on the skin. Sun worshipping and sun therapy has been en vogue for centuries, but in another way than used today. A changing lifestyle has led to an increase of various skin diseases, including skin cancer. Short wave UV-light (UV-B) in particular has been blamed for inducing not only erythema and pigmentation but also more chronic skin lesions. Long wave UV-light (UV-A) has been shown to be the cause of similar changes to the skin but the pigmentation is of another quality and affords less protection against the harmful effects of UV-B. A concept of sun reactive skin typing has been created. This is based on self-reported responses to an initial exposure to sun as regards tanning ability and erythema reaction. These two factors have certain practical consequences, not only for UV-phototherapy but also for a person's risk of developing skin cancer. Recently, several research groups and dermatologists have discouraged extensive use of UV-A sun beds because of side effects of varying degrees of seriousness. The possible implications of these side effects for the organism are not fully elucidated and may be more profound than known today. The British Photodermatology Group has issued more stringent rules for persons who, despite advice to the contrary, still wish to use UV-A sun beds. 14 refs., 1 tab.

  19. Lifestyle, sun worshipping and sun tanning - what about UV-A sun beds. Livsstil, soling og bruning - hva med UV-A solarier

    Energy Technology Data Exchange (ETDEWEB)

    Thune, P [Ullevaal Sykehus, Oslo (Norway)

    1991-06-01

    This article considers the effects of ultraviolet (UV) light from the sun and UV-A sun beds on the skin. Sun worshipping and sun therapy has been en vogue for centuries, but in another way than used today. A changing lifestyle has led to an increase of various skin diseases, including skin cancer. Short wave UV-light (UV-B) in particular has been blamed for inducing not only erythema and pigmentation but also more chronic skin lesions. Long wave UV-light (UV-A) has been shown to be the cause of similar changes to the skin but the pigmentation is of another quality and affords less protection against the harmful effects of UV-B. A concept of sun reactive skin typing has been created. This is based on self-reported responses to an initial exposure to sun as regards tanning ability and erythema reaction. These two factors have certain practical consequences, not only for UV-phototherapy but also for a person's risk of developing skin cancer. Recently, several research groups and dermatologists have discouraged extensive use of UV-A sun beds because of side effects of varying degrees of seriousness. The possible implications of these side effects for the organism are not fully elucidated and may be more profound than known today. The British Photodermatology Group has issued more stringent rules for persons who, despite advice to the contrary, still wish to use UV-A sun beds. 14 refs., 1 tab.

  20. The depth of the honeybee's backup sun-compass systems.

    Science.gov (United States)

    Dovey, Katelyn M; Kemfort, Jordan R; Towne, William F

    2013-06-01

    Honeybees have at least three compass mechanisms: a magnetic compass; a celestial or sun compass, based on the daily rotation of the sun and sun-linked skylight patterns; and a backup celestial compass based on a memory of the sun's movements over time in relation to the landscape. The interactions of these compass systems have yet to be fully elucidated, but the celestial compass is primary in most contexts, the magnetic compass is a backup in certain contexts, and the bees' memory of the sun's course in relation to the landscape is a backup system for cloudy days. Here we ask whether bees have any further compass systems, for example a memory of the sun's movements over time in relation to the magnetic field. To test this, we challenged bees to locate the sun when their known celestial compass systems were unavailable, that is, under overcast skies in unfamiliar landscapes. We measured the bees' knowledge of the sun's location by observing their waggle dances, by which foragers indicate the directions toward food sources in relation to the sun's compass bearing. We found that bees have no celestial compass systems beyond those already known: under overcast skies in unfamiliar landscapes, bees attempt to use their landscape-based backup system to locate the sun, matching the landscapes or skylines at the test sites with those at their natal sites as best they can, even if the matches are poor and yield weak or inconsistent orientation.

  1. 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.

  2. 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.

  3. The SunWise Policy Intervention for School-Based Sun Protection: A Pilot Study

    Science.gov (United States)

    Emmons, Karen M.; Geller, Alan C.; Viswanath, Vish; Rutsch, Linda; Zwirn, Jodie; Gorham, Sue; Puleo, Elaine

    2008-01-01

    Skin cancer is highly preventable, but clearly there is a critical need to focus on better ways to disseminate information about known skin cancer prevention. The U.S. Environmental Protection Agency's (EPA) SunWise Program is one channel for reaching children, teachers, and school nurses. In a pilot study designed to increase adoption of…

  4. 'My child did not like using sun protection': practices and perceptions of child sun protection among rural black African mothers.

    Science.gov (United States)

    Kunene, Zamantimande; Albers, Patricia N; Lucas, Robyn M; Banwell, Cathy; Mathee, Angela; Wright, Caradee Y

    2017-08-25

    Photodamage is partially mitigated by darker skin pigmentation, but immune suppression, photoaging and cataracts occur among individuals with all skin types. To assess practices and acceptability to Black African mothers of sun protection equipment for their children living in a rural area, participants were recruited at the time of their child's 18-month vaccinations. Mothers completed a baseline questionnaire on usual sun behaviours and sun protection practices. They were then provided with sun protection equipment and advice. A follow-up questionnaire was administered two weeks later. Mothers reported that during the week prior to the baseline questionnaire, children spent on average less than 1 hour of time outdoors (most often spent in the shade). Most mothers (97%) liked the sun protection equipment. However, many (78 of 86) reported that their child did not like any of the sun protection equipment and two-thirds stated that the sun protection equipment was not easy to use. Among Black Africans in rural northern South Africa, we found a mismatch between parental preferences and child acceptance for using sun protection when outdoors. A better understanding of the health risks of incidental excess sun exposure and potential benefits of sun protection is required among Black Africans.

  5. ultra-Stable Spectrometer for Sky-Scanning, Sun-Tracking Atmospheric Research (5STAR)

    Science.gov (United States)

    Dunagan, S. E.; Johnson, R. R.; Redemann, J.; Holben, B. N.; Schmid, B.; Flynn, C. J.; Fahey, L.; LeBlanc, S. E.; Liss, J.; Kacenelenbogen, M. S.; Segal-Rosenhaimer, M.; Shinozuka, Y.; Dahlgren, R. P.; Pistone, K.; Karol, Y.

    2017-12-01

    The Spectrometer for Sky-Scanning, Sun-Tracking Atmospheric Research (4STAR) combines airborne sun tracking and sky scanning with diffraction spectroscopy to improve knowledge of atmospheric constituents and their links to air pollution and climate. Direct beam hyperspectral measurement of optical depth improves retrievals of gas constituents and determination of aerosol properties. Sky scanning enhances retrievals of aerosol type and size distribution. Hyperspectral cloud-transmitted radiance measurements enable the retrieval of cloud properties from below clouds. These measurements tighten the closure between satellite and ground-based measurements. 4STAR incorporates a modular sun-tracking/ sky-scanning optical head with optical fiber signal transmission to rack mounted spectrometers, permitting miniaturization of the external optical tracking head, and future detector evolution. 4STAR has supported a broad range of flight experiments since it was first flown in 2010. This experience provides the basis for a series of improvements directed toward reducing measurement uncertainty and calibration complexity, and expanding future measurement capabilities, to be incorporated into a new 5STAR instrument. A 9-channel photodiode radiometer with AERONET-matched bandpass filters will be incorporated to improve calibration stability. A wide dynamic range tracking camera will provide a high precision solar position tracking signal as well as an image of sky conditions around the solar axis. An ultrasonic window cleaning system design will be tested. A UV spectrometer tailored for formaldehyde and SO2 gas retrievals will be added to the spectrometer enclosure. Finally, expansion capability for a 4 channel polarized radiometer to measure the Stokes polarization vector of sky light will be incorporated. This paper presents initial progress on this next-generation 5STAR instrument. Keywords: atmosphere; climate; pollution; radiometry; technology; hyperspectral; fiber optic

  6. What is the sun's real potential?

    International Nuclear Information System (INIS)

    Joliot, P.

    2009-01-01

    The sun has colossal energy potential, yet it is barely exploited. It radiates 10,000 times more energy than man now uses. Plants only recover one thousandth of this immense energy source. A closer look at the potential of processes for using solar energy, from photovoltaics to biofuels and biomass to the 'promise' of artificial photosynthesis The sun represents an inexhaustible source of energy. It is the well from which most of the energy sources available on the earth's surface spring, excepting nuclear and geothermal energy. Among the methods capable of recovering solar energy directly, three of them are currently in use: - Producing hot water with solar collectors; - High-temperature thermal power plants (1,000 deg.C or more); - Photovoltaics. Photovoltaic electricity already represents a significant source of energy in areas with low population density. Generating such power can also help meet the basic needs of poor countries. The last two methods nevertheless require a means for storing the energy produced, a function provided by the hot water tank in the first method. What about photosynthetic reactions that convert solar energy into chemical energy? Photosynthesis not only synthesizes organic products, it also recycles carbon dioxide and regenerates oxygen, all of which are vital to maintaining life on earth. We currently expect to produce renewable energy - mainly biofuels - by converting biomass produced by photosynthesis. Plants generally store less than 1% of the sun's energy in their organic matter. This feeble energy balance can become negative when the energy spent for sowing, harvesting and processing is taken into account, especially if only a fraction of the organic matter is actually collected, as in the case of corn or rapeseed oil. The substantial amount of land and water needed to produce large quantities of biofuels would put too much strain on food crops, especially in light of the large and ever growing numbers of people suffering from

  7. Sensors, Volume 4, Thermal Sensors

    Science.gov (United States)

    Scholz, Jorg; Ricolfi, Teresio

    1996-12-01

    'Sensors' is the first self-contained series to deal with the whole area of sensors. It describes general aspects, technical and physical fundamentals, construction, function, applications and developments of the various types of sensors. This volume describes the construction and applicational aspects of thermal sensors while presenting a rigorous treatment of the underlying physical principles. It provides a unique overview of the various categories of sensors as well as of specific groups, e.g. temperature sensors (resistance thermometers, thermocouples, and radiation thermometers), noise and acoustic thermometers, heat-flow and mass-flow sensors. Specific facettes of applications are presented by specialists from different fields including process control, automotive technology and cryogenics. This volume is an indispensable reference work and text book for both specialists and newcomers, researchers and developers.

  8. A Solar Position Sensor Based on Image Vision.

    Science.gov (United States)

    Ruelas, Adolfo; Velázquez, Nicolás; Villa-Angulo, Carlos; Acuña, Alexis; Rosales, Pedro; Suastegui, José

    2017-07-29

    Solar collector technologies operate with better performance when the Sun beam direction is normal to the capturing surface, and for that to happen despite the relative movement of the Sun, solar tracking systems are used, therefore, there are rules and standards that need minimum accuracy for these tracking systems to be used in solar collectors' evaluation. Obtaining accuracy is not an easy job, hence in this document the design, construction and characterization of a sensor based on a visual system that finds the relative azimuth error and height of the solar surface of interest, is presented. With these characteristics, the sensor can be used as a reference in control systems and their evaluation. The proposed sensor is based on a microcontroller with a real-time clock, inertial measurement sensors, geolocation and a vision sensor, that obtains the angle of incidence from the sunrays' direction as well as the tilt and sensor position. The sensor's characterization proved how a measurement of a focus error or a Sun position can be made, with an accuracy of 0.0426° and an uncertainty of 0.986%, which can be modified to reach an accuracy under 0.01°. The validation of this sensor was determined showing the focus error on one of the best commercial solar tracking systems, a Kipp & Zonen SOLYS 2. To conclude, the solar tracking sensor based on a vision system meets the Sun detection requirements and components that meet the accuracy conditions to be used in solar tracking systems and their evaluation or, as a tracking and orientation tool, on photovoltaic installations and solar collectors.

  9. Surya Namaskar (Sun Salutation): A Path to Good Health

    OpenAIRE

    Amit Vaibhav; Swati Shukla; Om Prakash Singh

    2016-01-01

    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 a...

  10. The quiet Sun brightness temperature at 408 MHz

    International Nuclear Information System (INIS)

    Avignon, Y.; Lantos, P.; Palagi, F.; Patriarchi, P.

    1975-01-01

    The flux of the radio quiet Sun and the brightness temperature at 408 MHz (73cm) are derived from measurements with the E-W Nancay interferometer and the E-W arm of the Medicina North Cross. It is shown that the lowest envelopes, which defined the radio quiet Sun, correspond to transits of extended coronal holes across the disk of the Sun. (Auth.)

  11. Remote sensing of atmospheric optical depth using a smartphone sun photometer.

    Science.gov (United States)

    Cao, Tingting; Thompson, Jonathan E

    2014-01-01

    In recent years, smart phones have been explored for making a variety of mobile measurements. Smart phones feature many advanced sensors such as cameras, GPS capability, and accelerometers within a handheld device that is portable, inexpensive, and consistently located with an end user. In this work, a smartphone was used as a sun photometer for the remote sensing of atmospheric optical depth. The top-of-the-atmosphere (TOA) irradiance was estimated through the construction of Langley plots on days when the sky was cloudless and clear. Changes in optical depth were monitored on a different day when clouds intermittently blocked the sun. The device demonstrated a measurement precision of 1.2% relative standard deviation for replicate photograph measurements (38 trials, 134 datum). However, when the accuracy of the method was assessed through using optical filters of known transmittance, a more substantial uncertainty was apparent in the data. Roughly 95% of replicate smart phone measured transmittances are expected to lie within ±11.6% of the true transmittance value. This uncertainty in transmission corresponds to an optical depth of approx. ±0.12-0.13 suggesting the smartphone sun photometer would be useful only in polluted areas that experience significant optical depths. The device can be used as a tool in the classroom to present how aerosols and gases effect atmospheric transmission. If improvements in measurement precision can be achieved, future work may allow monitoring networks to be developed in which citizen scientists submit acquired data from a variety of locations.

  12. Imaging Sensors

    Indian Academy of Sciences (India)

    BASE. /. VIDEO SIGNAL. L SILICON ceD "UX. ---HEADER. ICc) bee's head is more than fifty times smaller than the human head! ... For a particular radius, the bee can increase the resolution of its .... For example, for 10 J..l m radiation and.

  13. Lack of adequate sun protection for children with oculocutaneous albinism in South Africa

    Science.gov (United States)

    Lund, Patricia M; Taylor, Julie S

    2008-01-01

    Background Childhood is a high risk time for ultraviolet induced skin damage as this age group has more time and opportunity to be outdoors in the sun. Children in Africa with the inherited condition oculocutaneous albinism (OCA) are especially vulnerable due to their lack of protective melanin. They are highly susceptible to developing skin lesions that have both cosmetic and health complications, with a high risk of developing skin cancers. The study aimed to explore the adequacy of sun protection strategies of children with albinism in order to inform future provision. Methods Community based participatory research methods were employed to investigate sun protection strategies in 90 pupils with OCA (40 female and 50 male) boarding at a special school educating pupils with visual impairment in a rural area of northern South Africa. Hats worn and sunscreen preparations used were examined during semi-structured face to face interviews conducted in small peer groups. The resident nurse interpreted if necessary and provided additional information on monitoring and treatment of skin lesions. Results Participants with albinism in this study were exposed to high levels of ultraviolet radiation throughout the year and showed skin damage despite wearing protective head gear. All except one pupil possessed at least one hat, with a mean brim width of 5.4 cm. Gender differences in sun avoidance behaviour were documented, with females seeking shade during recreational periods and males playing soccer outside. Although 38% of pupils were using a sunscreen with a sun protection factor (SPF) rating, only 12% had government sponsored tubes of SPF15 cream. Government sponsored sunscreen preparations were only provided if actively sought, involving time consuming trips to regional hospitals, with inadequate availability and insufficient supply. Conclusion Children with albinism living away from home in rural areas appear to have inadequate sun protection strategies. Changes in

  14. Lack of adequate sun protection for children with oculocutaneous albinism in South Africa

    Directory of Open Access Journals (Sweden)

    Taylor Julie S

    2008-06-01

    Full Text Available Abstract Background Childhood is a high risk time for ultraviolet induced skin damage as this age group has more time and opportunity to be outdoors in the sun. Children in Africa with the inherited condition oculocutaneous albinism (OCA are especially vulnerable due to their lack of protective melanin. They are highly susceptible to developing skin lesions that have both cosmetic and health complications, with a high risk of developing skin cancers. The study aimed to explore the adequacy of sun protection strategies of children with albinism in order to inform future provision. Methods Community based participatory research methods were employed to investigate sun protection strategies in 90 pupils with OCA (40 female and 50 male boarding at a special school educating pupils with visual impairment in a rural area of northern South Africa. Hats worn and sunscreen preparations used were examined during semi-structured face to face interviews conducted in small peer groups. The resident nurse interpreted if necessary and provided additional information on monitoring and treatment of skin lesions. Results Participants with albinism in this study were exposed to high levels of ultraviolet radiation throughout the year and showed skin damage despite wearing protective head gear. All except one pupil possessed at least one hat, with a mean brim width of 5.4 cm. Gender differences in sun avoidance behaviour were documented, with females seeking shade during recreational periods and males playing soccer outside. Although 38% of pupils were using a sunscreen with a sun protection factor (SPF rating, only 12% had government sponsored tubes of SPF15 cream. Government sponsored sunscreen preparations were only provided if actively sought, involving time consuming trips to regional hospitals, with inadequate availability and insufficient supply. Conclusion Children with albinism living away from home in rural areas appear to have inadequate sun protection

  15. Grand Minima: Is The Sun Going To Sleep?

    Science.gov (United States)

    Mcintosh, S. W.; Leamon, R. J.

    2014-12-01

    We explore recent observational work which indicate that the energetics of the sun's outer atmosphere have been on a steady decline for the past decade and perhaps longer. Futher, we show that new investigations into evolution of the Sun's global magnetic activity appear to demonstrate a path through which the Sun can go into, and exit from, a grand activity minimum without great difficulty while retaining an activity cycle - only losing sunspots. Are we at the begining of a new grand(-ish) minimum? Naturally, only time will tell, but the observational evidence hint that one may not be far off to what impact on the Sun-Earth Connection.

  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. Public health challenges in sun protection.

    Science.gov (United States)

    Eide, Melody J; Weinstock, Martin A

    2006-01-01

    Sunscreens are a popular choice for protection from ultraviolet radiation, and hence, important components in the public health campaign to reduce the burden of skin cancer. Public health messages in skin cancer prevention have been used effectively in educational campaigns. The benefits of sunscreen extend beyond skin cancer prevention into other aspects of health and disease prevention: sunscreen decreases the risk for sunburn during physical activity outdoors and seems not to increase the risk for osteoporosis. Public health efforts have laid a solid foundation on which to face the continuing challenge of promoting and developing effective public health campaigns and health policies that encourage sunscreen use, sun protection, and the primary prevention of skin cancer. In this article, the controversies, concerns, and challenges of sunscreen use as it relates to public health are discussed.

  18. 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...

  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. AHP 21: Review: The Sun Rises

    Directory of Open Access Journals (Sweden)

    Mark Bender

    2012-12-01

    Full Text Available 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. ...

  1. Sun's pole-equator flux differences

    Energy Technology Data Exchange (ETDEWEB)

    Belvedere, G [Istituto di Astronomia dell' Universita di Catania, Italy; Paterno, L [Osservatorio Astrofisico di Catania, Italy

    1977-04-01

    The possibility that large flux differences between the poles and the equator at the bottom of the solar convective zone are compatible with the small differences observed at the surface is studied. The consequences of increasing the depth of the convective zone due to overshooting are explored. A Boussinesq model is used for the convective zone and it is assumed that the interaction of the global convection with rotation is modelled through a convective flux coefficient whose perturbed part is proportional to the local Taylor number. The numerical integration of the equations of motion and energy shows that coexistence between large pole-equator flux differences at the bottom and small ones at the surface is possible if the solar convective zone extends to a depth of 0.4 R(Sun). The angular velocity distribution inside the convective zone is in agreement with the ..cap alpha omega..-dynamo theories of the solar cycle.

  2. Head CT scan

    Science.gov (United States)

    ... scan - orbits; CT scan - sinuses; Computed tomography - cranial; CAT scan - brain ... head size in children Changes in thinking or behavior Fainting Headache, when you have certain other signs ...

  3. Bottom head assembly

    International Nuclear Information System (INIS)

    Fife, A.B.

    1998-01-01

    A bottom head dome assembly is described which includes, in one embodiment, a bottom head dome and a liner configured to be positioned proximate the bottom head dome. The bottom head dome has a plurality of openings extending there through. The liner also has a plurality of openings extending there through, and each liner opening aligns with a respective bottom head dome opening. A seal is formed, such as by welding, between the liner and the bottom head dome to resist entry of water between the liner and the bottom head dome at the edge of the liner. In the one embodiment, a plurality of stub tubes are secured to the liner. Each stub tube has a bore extending there through, and each stub tube bore is coaxially aligned with a respective liner opening. A seat portion is formed by each liner opening for receiving a portion of the respective stub tube. The assembly also includes a plurality of support shims positioned between the bottom head dome and the liner for supporting the liner. In one embodiment, each support shim includes a support stub having a bore there through, and each support stub bore aligns with a respective bottom head dome opening. 2 figs

  4. Design of a Solar Tracking System Using the Brightest Region in the Sky Image Sensor.

    Science.gov (United States)

    Wei, Ching-Chuan; Song, Yu-Chang; Chang, Chia-Chi; Lin, Chuan-Bi

    2016-11-25

    Solar energy is certainly an energy source worth exploring and utilizing because of the environmental protection it offers. However, the conversion efficiency of solar energy is still low. If the photovoltaic panel perpendicularly tracks the sun, the solar energy conversion efficiency will be improved. In this article, we propose an innovative method to track the sun using an image sensor. In our method, it is logical to assume the points of the brightest region in the sky image representing the location of the sun. Then, the center of the brightest region is assumed to be the solar-center, and is mathematically calculated using an embedded processor (Raspberry Pi). Finally, the location information on the sun center is sent to the embedded processor to control two servo motors that are capable of moving both horizontally and vertically to track the sun. In comparison with the existing sun tracking methods using image sensors, such as the Hough transform method, our method based on the brightest region in the sky image remains accurate under conditions such as a sunny day and building shelter. The practical sun tracking system using our method was implemented and tested. The results reveal that the system successfully captured the real sun center in most weather conditions, and the servo motor system was able to direct the photovoltaic panel perpendicularly to the sun center. In addition, our system can be easily and practically integrated, and can operate in real-time.

  5. Design of a Solar Tracking System Using the Brightest Region in the Sky Image Sensor

    Directory of Open Access Journals (Sweden)

    Ching-Chuan Wei

    2016-11-01

    Full Text Available Solar energy is certainly an energy source worth exploring and utilizing because of the environmental protection it offers. However, the conversion efficiency of solar energy is still low. If the photovoltaic panel perpendicularly tracks the sun, the solar energy conversion efficiency will be improved. In this article, we propose an innovative method to track the sun using an image sensor. In our method, it is logical to assume the points of the brightest region in the sky image representing the location of the sun. Then, the center of the brightest region is assumed to be the solar-center, and is mathematically calculated using an embedded processor (Raspberry Pi. Finally, the location information on the sun center is sent to the embedded processor to control two servo motors that are capable of moving both horizontally and vertically to track the sun. In comparison with the existing sun tracking methods using image sensors, such as the Hough transform method, our method based on the brightest region in the sky image remains accurate under conditions such as a sunny day and building shelter. The practical sun tracking system using our method was implemented and tested. The results reveal that the system successfully captured the real sun center in most weather conditions, and the servo motor system was able to direct the photovoltaic panel perpendicularly to the sun center. In addition, our system can be easily and practically integrated, and can operate in real-time.

  6. Head waves in ultrasonic testing. Physical principle and application to welded joint testing

    International Nuclear Information System (INIS)

    Wustenberg, H.; Erhard, A.

    1984-01-01

    A head wave sensor is developed from distinct emitter and receiver sensors using longitudinal waves under a 70 0 incidence. These heat wave sensors present a high sensitivity for underlying cracks and are not influenced by surface accidents like liquid drops or welding projection. They are multi mode sensors emitting simultaneously longitudinal head waves, a main longitudinal lobe and a transverse wave with a maximum at about 38 0 . This wave combination can be used for automatic testing of welded joints even with austenitic materials for defect detection near internal or external surfaces. This process can substitute or complete liquid penetrant inspection or magnetic inspection for testing pipes (13 references are given) [fr

  7. Fly me to the Sun! ESA inaugurates the European Project on the Sun

    Science.gov (United States)

    2000-11-01

    In an initiative mounted by ECSITE (European Collaborative for Science, Industry and Technology Exhibitions) with funding from the European Commission and under the supervision, coordination and co-sponsorship of ESA, five teams of youngsters (16-18 years old) from Belgium, France, Germany, Italy and the Netherlands were selected and coordinated by European science museums from each of their countries (Musée des Sciences et des Techniques - Parentville, B; Cité de l'Espace - Toulouse, F; Deutsches Museum - Munich, D; Fondazione IDIS - Naples, I; Foundation Noordwijk Space Expo - Noordwijk, NL). The teams each focused on a theme related to solar research: "How does the Sun work?" (I), "The Sun as a star" (F), "Solar activity" (NL), "Observing the Sun" (D), "Humans and the Sun" (B), and built exhibition "modules" that they will present at the inauguration, in the context of European Science and Technology Week 2000 (6-10 November), promoted by the European Commission. During the two-day event, a jury of representatives of other European science and technology museums, ESA scientists, a science journalist, and two ESA astronauts (Frank de Winne and Andre Kuipers) will judge the youngsters' exhibition modules on the basis of their scientific correctness, their museological value and the commitment shown by the young "communication experts". The winning team will be officially announced on 9 November. The prize is a weekend at the Space Camp in Redu, Belgium. The objective of the European Project on the Sun is educational. It aims, through the direct and "fresh" involvement of youngsters, to heighten European citizens' awareness of space research in general and the Sun's influence on our daily lives in particular. The role of the European Space Agency as reference point in Europe for solar research has been fundamental to the project. From ESA's perspective, EPOS is part of this autumn's wider communication initiative called the Solar Season, which is highlighting ESA

  8. Seasonal hydroclimatic impacts of Sun Corridor expansion

    International Nuclear Information System (INIS)

    Georgescu, M; Mahalov, A; Moustaoui, M

    2012-01-01

    Conversion of natural to urban land forms imparts influence on local and regional hydroclimate via modification of the surface energy and water balance, and consideration of such effects due to rapidly expanding megapolitan areas is necessary in light of the growing global share of urban inhabitants. Based on a suite of ensemble-based, multi-year simulations using the Weather Research and Forecasting (WRF) model, we quantify seasonally varying hydroclimatic impacts of the most rapidly expanding megapolitan area in the US: Arizona’s Sun Corridor, centered upon the Greater Phoenix metropolitan area. Using a scenario-based urban expansion approach that accounts for the full range of Sun Corridor growth uncertainty through 2050, we show that built environment induced warming for the maximum development scenario is greatest during the summer season (regionally averaged warming over AZ exceeds 1 °C). Warming remains significant during the spring and fall seasons (regionally averaged warming over AZ approaches 0.9 °C during both seasons), and is least during the winter season (regionally averaged warming over AZ of 0.5 °C). Impacts from a minimum expansion scenario are reduced, with regionally averaged warming ranging between 0.1 and 0.3 °C for all seasons except winter, when no warming impacts are diagnosed. Integration of highly reflective cool roofs within the built environment, increasingly recognized as a cost-effective option intended to offset the warming influence of urban complexes, reduces urban-induced warming considerably. However, impacts on the hydrologic cycle are aggravated via enhanced evapotranspiration reduction, leading to a 4% total accumulated precipitation decrease relative to the non-adaptive maximum expansion scenario. Our results highlight potentially unintended consequences of this adaptation approach within rapidly expanding megapolitan areas, and emphasize the need for undeniably sustainable development paths that account for

  9. Gas Sensor

    KAUST Repository

    Luebke, Ryan

    2015-01-22

    A gas sensor using a metal organic framework material can be fully integrated with related circuitry on a single substrate. In an on-chip application, the gas sensor can result in an area-efficient fully integrated gas sensor solution. In one aspect, a gas sensor can include a first gas sensing region including a first pair of electrodes, and a first gas sensitive material proximate to the first pair of electrodes, wherein the first gas sensitive material includes a first metal organic framework material.

  10. Gas Sensor

    KAUST Repository

    Luebke, Ryan; Eddaoudi, Mohamed; Omran, Hesham; Belmabkhout, Youssef; Shekhah, Osama; Salama, Khaled N.

    2015-01-01

    A gas sensor using a metal organic framework material can be fully integrated with related circuitry on a single substrate. In an on-chip application, the gas sensor can result in an area-efficient fully integrated gas sensor solution. In one aspect, a gas sensor can include a first gas sensing region including a first pair of electrodes, and a first gas sensitive material proximate to the first pair of electrodes, wherein the first gas sensitive material includes a first metal organic framework material.

  11. Sensor web

    Science.gov (United States)

    Delin, Kevin A. (Inventor); Jackson, Shannon P. (Inventor)

    2011-01-01

    A Sensor Web formed of a number of different sensor pods. Each of the sensor pods include a clock which is synchronized with a master clock so that all of the sensor pods in the Web have a synchronized clock. The synchronization is carried out by first using a coarse synchronization which takes less power, and subsequently carrying out a fine synchronization to make a fine sync of all the pods on the Web. After the synchronization, the pods ping their neighbors to determine which pods are listening and responded, and then only listen during time slots corresponding to those pods which respond.

  12. A MEMS SOI-based piezoresistive fluid flow sensor

    Science.gov (United States)

    Tian, B.; Li, H. F.; Yang, H.; Song, D. L.; Bai, X. W.; Zhao, Y. L.

    2018-02-01

    In this paper, a SOI (silicon-on-insulator)-based piezoresistive fluid flow sensor is presented; the presented flow sensor mainly consists of a nylon sensing head, stainless steel cantilever beam, SOI sensor chip, printed circuit board, half-cylinder gasket, and stainless steel shell. The working principle of the sensor and some detailed contrastive analysis about the sensor structure were introduced since the nylon sensing head and stainless steel cantilever beam have distinct influence on the sensor performance; the structure of nylon sensing head and stainless steel cantilever beam is also discussed. The SOI sensor chip was fabricated using micro-electromechanical systems technologies, such as reactive ion etching and low pressure chemical vapor deposition. The designed fluid sensor was packaged and tested; a calibration installation system was purposely designed for the sensor experiment. The testing results indicated that the output voltage of the sensor is proportional to the square of the fluid flow velocity, which is coincident with the theoretical derivation. The tested sensitivity of the sensor is 3.91 × 10-4 V ms2/kg.

  13. The evolution of protostellar envelopes of masses 3 Msub(sun) and 10 Msub(sun)

    International Nuclear Information System (INIS)

    Yorke, H.W.

    1979-10-01

    The results of numerical calculations solving the coupled equations of hydrodynamics and radiation transfer are presented in a sequence of papers describing the structure, evolution and appearance of protostellar clouds of intermediate mass (3 Msub(sun) 10 Msub(sun). These numerical calculations begin at the time of initial gravitational collapse and continue through the birth of a central protostar, until the infall of material onto the central object has been reversed. For the 10 M case the formation and evolution of a compact HII region is crudely followed after the gas density in the envelope had decreased sufficiently to allow an ionization front to propagate outwards. For all cases calculated spherical symmetry was assumed. Solar abundances were used. (orig.) 891 WL/orig. 892 RDG

  14. Predictors of sun protection behaviours and sunburn among Australian adolescents.

    Science.gov (United States)

    Pettigrew, Simone; Jongenelis, Michelle; Strickland, Mark; Minto, Carolyn; Slevin, Terry; Jalleh, Geoffrey; Lin, Chad

    2016-07-13

    Excessive sun exposure and sunburn increase individuals' risk of skin cancer. It is especially important to prevent sunburn in childhood due to the higher relative risk of skin cancer across the life span compared to risk associated with sunburn episodes experienced later in life. This study examined demographic and attitudinal factors associated with engagement in a range of sun protection behaviours (wearing a hat, wearing protective clothing, staying in the shade, and staying indoors during the middle of the day) and the frequency of sunburn among Western Australian adolescents to provide insights of relevance for future sun protection campaigns. Cross-sectional telephone surveys were conducted annually with Western Australians between 2005/06 and 2014/15. The results from 4150 adolescents aged 14-17 years were used to conduct a path analysis of factors predicting various sun protection behaviours and sunburn. Significant primary predictors of the sun protection behaviours included in the study were skin type (sun sensitivity), gender, tanning-related attitudes and behaviours, and perceived relevance of public service advertisements that advocate sun protection. Of the four sun protection behaviours investigated, staying in the shade and staying indoors during the middle of the day were associated with a lower frequency of sunburn. There is a particular need to target sun protection messages at adolescent males who are less likely to engage in the most effective sun protection behaviours and demonstrate an increased propensity to experience sunburn. The results suggest that such future sun protection messages should include a focus on the importance of staying in the shade or indoors during periods of high UV radiation to increase awareness of the efficacy of these methods of avoiding skin cancer.

  15. 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.

  16. Predictors of sun protection behaviours and sunburn among Australian adolescents

    Directory of Open Access Journals (Sweden)

    Simone Pettigrew

    2016-07-01

    Full Text Available Abstract Background Excessive sun exposure and sunburn increase individuals’ risk of skin cancer. It is especially important to prevent sunburn in childhood due to the higher relative risk of skin cancer across the life span compared to risk associated with sunburn episodes experienced later in life. This study examined demographic and attitudinal factors associated with engagement in a range of sun protection behaviours (wearing a hat, wearing protective clothing, staying in the shade, and staying indoors during the middle of the day and the frequency of sunburn among Western Australian adolescents to provide insights of relevance for future sun protection campaigns. Methods Cross-sectional telephone surveys were conducted annually with Western Australians between 2005/06 and 2014/15. The results from 4150 adolescents aged 14–17 years were used to conduct a path analysis of factors predicting various sun protection behaviours and sunburn. Results Significant primary predictors of the sun protection behaviours included in the study were skin type (sun sensitivity, gender, tanning-related attitudes and behaviours, and perceived relevance of public service advertisements that advocate sun protection. Of the four sun protection behaviours investigated, staying in the shade and staying indoors during the middle of the day were associated with a lower frequency of sunburn. Conclusion There is a particular need to target sun protection messages at adolescent males who are less likely to engage in the most effective sun protection behaviours and demonstrate an increased propensity to experience sunburn. The results suggest that such future sun protection messages should include a focus on the importance of staying in the shade or indoors during periods of high UV radiation to increase awareness of the efficacy of these methods of avoiding skin cancer.

  17. 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

  18. Vortices in the SU(N) x SU(N) spin systems in two dimensions

    International Nuclear Information System (INIS)

    Kares, R.J.D.

    1982-01-01

    The SU(N) x SU(N) or chiral spin systems in two dimensions with spin variables in both the fundamental and the adjoint representations of SU(N) are considered. In the adjoint representation the chiral models are found to possess topologically stable, classical vortex solutions which carry a Z(N) topological charge. A relationship is established between the chiral models and massive Yang-Mills theory in two dimensions. This relationship is exploited to prove the asymptotic freedom of the chiral models and to find their weak coupling mass gap. The connection between the vortices of the chiral models and those of the massive Yang-Mills theory is discussed. The behavior of a gas of vortices in the SU(2) chiral model is considered. This gas is converted to an equivalent field theory and studied using the renormalization group. It is shown that the SU(2) vortex gas does not undergo a Kosterlitz-Thouless phase transition. This behavior probably persists for the higher SU(N) groups as well. Finally, using the massive Yang-Mills theory the effect of the coupling of vortices to spin wave fluctuations is investigated. It is argued that as a result of the vortex-spin wave interaction the vortices acquire a mass scale dynamically. A self consistency condition is derived for the vortex scale and used to compute the mass gap for the chiral models in the presence of vortices. The mass gap obtained in this way is found to be in agreement with the weak coupling result suggesting that vortices may be responsible for generating the mass gap in the chiral models near T = 0

  19. 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…

  20. 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

    2016-06-01

    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 available publicly. Total SPP scores were low {mean 3.6 [95% CI: 3.4-3.9]; median 2 [interquartile range (IQR) 2, 4]}, with only 3.2% of schools achieving the maximum score of 12. Median SPP scores were higher in Northern and Central Queensland [both 2 (IQR 2, 6) and (IQR 2, 5), respectively] than in Southern Queensland [2 (IQR 2, 3); P = 0.004]. Clothing and hat-wearing were addressed in most policies (96% and 89%) while few schools used their SPP to plan outdoor events (5.2%) or reschedule activities to minimize sun exposure (11.7%). The SunSmart Schools program has been operating in Queensland for 17 years, and while most primary schools now have a written SPP, most are not comprehensive. Incentive-based approaches (5-star-rating award scheme and grants) may assist in addressing this issue, to reduce sun exposure of students and teachers. These data provide a baseline from which improvements in the comprehensiveness of school SPPs can be evaluated. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  1. A Forward Authentication Key Management Scheme for Heterogeneous Sensor Networks

    Directory of Open Access Journals (Sweden)

    Huang Jen-Yan

    2011-01-01

    Full Text Available Key encryption technology is a basic technique for protecting the secrecy of transmitted data among sensor nodes in wireless sensor networks. However, sensor nodes are inherently limited by insufficient hardware resources such as memory capacity and battery lifetime. As a result, few current key management schemes are appropriate for wireless sensor networks. This paper proposes a new key management method that uses dynamic key management schemes for heterogeneous sensor networks. The proposed scheme loads a hash function into the base station, cluster heads, and sensor nodes. The cluster heads and sensor nodes then generate their own keychains to provide forward authentication in case of key changes, security breaches, key changes due to security breaches. The cluster heads and sensor nodes establish pairwise keys to ensure transmission secrecy. The proposed scheme decreases the number of keys required for sensor nodes and cluster heads and is robust to the following attacks: guessing attacks, replay attacks, man-in-the-middle attacks, node capture attacks, and denial-of-service attacks.

  2. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... Physician Resources Professions Site Index A-Z Computed Tomography (CT) - Head Computed tomography (CT) of the head uses special x-ray equipment ... story here Images × Image Gallery Patient undergoing computed tomography (CT) scan. View full size with caption Pediatric Content ...

  3. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... Computed tomography (CT) of the head uses special x-ray equipment to help assess head injuries, severe headaches, ... is a diagnostic medical test that, like traditional x-rays, produces multiple images or pictures of the inside ...

  4. Novel Framework for Data Collection in Wireless Sensor Networks Using Flying Sensors

    DEFF Research Database (Denmark)

    Mathur, Prateek; Nielsen, Rasmus Hjorth; Prasad, Neeli R.

    2014-01-01

    This paper proposes a novel framework for data collection from a sensor network using flying sensor nodes. Efficient data communication within the network is a necessity as sensor nodes are usually energy constrained. The proposed framework utilizes the various entities forming the network...... for a different utility compared to their usual role in sensor networks. Use of flying sensor nodes is usually considered for conventional purpose of sensing and monitoring. Flying sensing nodes are usually utilized collectively in the form of an aerial sensor network, they are not expected to function as a data...... collection entity, as proposed in this framework. Similarly, cluster heads (CHs) are usually expected to transfer the aggregated data to an adjoining CH or to the base station (BS) directly. In the proposed framework the CH transfers data directly to the flying sensor node, averting the need for energy...

  5. Reactor head shielding apparatus

    International Nuclear Information System (INIS)

    Schukei, G.E.; Roebelen, G.J.

    1992-01-01

    This patent describes a nuclear reactor head shielding apparatus for mounting on spaced reactor head lifting members radially inwardly of the head bolts. It comprises a frame of sections for mounting on the lifting members and extending around the top central area of the head, mounting means for so mounting the frame sections, including downwardly projecting members on the frame sections and complementary upwardly open recessed members for fastening to the lifting members for receiving the downwardly projecting members when the frame sections are lowered thereto with lead shielding supported thereby on means for hanging lead shielding on the frame to minimize radiation exposure or personnel working with the head bolts or in the vicinity thereof

  6. 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…

  7. Cell Phones and Sun Shadows: Exploring the Equation of Time

    Science.gov (United States)

    Madden, Sean P.

    2010-01-01

    For thousands of years before the invention of reliable clocks, humans measured their days by the motion of the sun. Astronomically, one day was the length of time it took for the sun to return to the same position in the sky. With the advent of precise mechanical chronometers such as Harrison's timekeepers (Sobel and Andrewes 1998), which ran at…

  8. Effect of smoking and sun drying on proximate composition of ...

    African Journals Online (AJOL)

    Effect of smoking and sun drying on proximate composition of Diplotaxodon fish species (Ndunduma) from lake Malawi, Malawi. ... African Journal of Food, Agriculture, Nutrition and Development ... The fish were washed then weighed and thereafter, smoked in a traditional smoking kiln and sun dried on reed mats.

  9. Sun Protection Motivational Stages and Behavior: Skin Cancer Risk Profiles

    Science.gov (United States)

    Pagoto, Sherry L.; McChargue, Dennis E.; Schneider, Kristin; Cook, Jessica Werth

    2004-01-01

    Objective: To create skin cancer risk profiles that could be used to predict sun protection among Midwest beachgoers. Method: Cluster analysis was used with study participants (N=239), who provided information about sun protection motivation and behavior, perceived risk, burn potential, and tan importance. Participants were clustered according to…

  10. THE SUN WAS NOT BORN IN M67

    International Nuclear Information System (INIS)

    Pichardo, Bárbara; Moreno, Edmundo; Allen, Christine; Bedin, Luigi R.; Bellini, Andrea; Pasquini, Luca

    2012-01-01

    Using the most recent proper-motion determination of the old, solar-metallicity, Galactic open cluster M67 in orbital computations in a non-axisymmetric model of the Milky Way, including a bar and three-dimensional spiral arms, we explore the possibility that the Sun once belonged to this cluster. We have performed Monte Carlo numerical simulations to generate the present-day orbital conditions of the Sun and M67, and all the parameters in the Galactic model. We compute 3.5 × 10 5 pairs of orbits Sun-M67 looking for close encounters in the past with a minimum distance approach within the tidal radius of M67. In these encounters we find that the relative velocity between the Sun and M67 is larger than 20 km s –1 . If the Sun had been ejected from M67 with this high velocity by means of a three-body encounter, this interaction would have either destroyed an initial circumstellar disk around the Sun or dispersed its already formed planets. We also find a very low probability, much lower than 10 –7 , that the Sun was ejected from M67 by an encounter of this cluster with a giant molecular cloud. This study also excludes the possibility that the Sun and M67 were born in the same molecular cloud. Our dynamical results convincingly demonstrate that M67 could not have been the birth cluster of our solar system.

  11. 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…

  12. 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…

  13. 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…

  14. Dynamics of the Sun-Earth-Moon System

    Indian Academy of Sciences (India)

    The dynamics of the Sun-Earth-Moon system is discussed with special attention to the effects of. Sun's perturbations on the Moon's orbit around the Earth. Important secular effects are the re- gression of the nodes, the advance of the perigee and the increase in the Moon's mean longitude. We discuss the relationship of the ...

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

    Science.gov (United States)

    ... sleeved shirts and long pants and skirts can provide protection from UV rays. Clothes made from tightly woven ... expected. Remember to plan ahead, and keep sun protection handy—in your car, bag, or child’s backpack. Sun Safety in Schools The Protect Your Students from Skin Cancer fact ...

  16. Chemical sensors

    International Nuclear Information System (INIS)

    Hubbard, C.W.; Gordon, R.L.

    1987-05-01

    The revolution in analytical chemistry promised by recent developments in the field of chemical sensors has potential for significant positive impact on both research and production activities conducted by and for the Department of Energy. Analyses which were, in the past, performed only with a roomful of expensive equipment can now be performed with miniature solid-state electronic devices or small optical probes. Progress in the development of chemical sensors has been rapid, and the field is currently growing at a great rate. In accordance, Pacific Northwest Laboratory initiated a survey of recent literature so that contributors to active programs in research on analytical methods could be made aware of principles and applications of this new technology. This report presents the results of that survey. The sensors discussed here are divided into three types: micro solid-state devices, optical sensors, and piezoelectric crystal devices. The report is divided into three corresponding sections. The first section, ''Micro Solid-State Devices,'' discusses the design, operation, and application of electronic sensors that are produced in much the same way as standard solid-state electronic devices. The second section, ''Optrodes,'' covers the design and operation of chemical sensors that use fiber optics to detect chemically induced changes in optical properties. The final section, ''Piezoelectric Crystal Detectors,'' discusses two types of chemical sensors that depend on the changes in the properties of an oscillating piezoelectric crystal to detect the presence of certain materials. Advantages and disadvantages of each type of sensor are summarized in each section

  17. Intelligent fiber optic sensor for solution concentration examination

    Science.gov (United States)

    Borecki, Michal; Kruszewski, Jerzy

    2003-09-01

    This paper presents the working principles of intelligent fiber-optic intensity sensor used for solution concentration examination. The sensor head is the ending of the large core polymer optical fiber. The head works on the reflection intensity basis. The reflected signal level depends on Fresnel reflection and reflection on suspended matter when the head is submersed in solution. The sensor head is mounted on a lift. For detection purposes the signal includes head submerging, submersion, emerging and emergence is measured. This way the viscosity turbidity and refraction coefficient has an effect on measured signal. The signal forthcoming from head is processed electrically in opto-electronic interface. Then it is feed to neural network. The novelty of presented sensor is implementation of neural network that works in generalization mode. The sensor resolution depends on opto-electronic signal conversion precision and neural network learning accuracy. Therefore, the number and quality of points used for learning process is very important. The example sensor application for examination of liquid soap concentration in water is presented in the paper.

  18. Omnidirectional vision applied to Unmanned Aerial Vehicles (UAVs) attitude and heading estimation

    OpenAIRE

    Mondragon, Ivan F.; Campoy, Pascual; Martinez, Carol; Olivares Mendez, Miguel Angel

    2010-01-01

    This paper presents an aircraft attitude and heading estimator using catadioptric images as a principal sensor for UAV or as a redundant system for IMU (Inertial Measure Unit) and gyro sensors. First, we explain how the unified theory for central catadioptric cameras is used for attitude and heading estimation, explaining how the skyline is projected on the catadioptric image and how it is segmented and used to calculate the UAV's attitude. Then, we use appearance images to obtain a visual co...

  19. Trends in sunburns, sun protection practices, and attitudes toward sun exposure protection and tanning among US adolescents, 1998-2004.

    Science.gov (United States)

    Cokkinides, Vilma; Weinstock, Martin; Glanz, Karen; Albano, Jessica; Ward, Elizabeth; Thun, Michael

    2006-09-01

    Sun exposure in childhood is an important risk factor for developing skin cancer as an adult. Despite extensive efforts to reduce sun exposure among the young, there are no population-based data on trends in sunburns and sun protection practices in the young. The aim of this study was to describe nationally representative trend data on sunburns, sun protection, and attitudes related to sun exposure among US youth. Cross-sectional telephone surveys of youth aged 11 to 18 years in 1998 (N = 1196) and in 2004 (N = 1613) were conducted using a 2-stage sampling process to draw population-based samples. The surveys asked identical questions about sun protection, number of sunburns experienced, and attitudes toward sun exposure. Time trends were evaluated using pooled logistic regression analysis. In 2004, 69% of subjects reported having been sunburned during the summer, not significantly less than in 1998 (72%). There was a significant decrease in the percentage of those aged 11 to 15 years who reported sunburns and a nonsignificant increase among the 16- to 18-year-olds. The proportion of youth who reported regular sunscreen use increased significantly from 31% to 39%. Little change occurred in other recommended sun protection practices. A small reduction in sunburn frequency and modest increases in sun protection practices were observed among youth between 1998 and 2004, despite widespread sun protection campaigns. Nevertheless, the decrease in sunburns among younger teens may be cause for optimism regarding future trends. Overall, there was rather limited progress in improving sun protection practices and reducing sunburns among US youth between 1998 and 2004.

  20. EARTH, MOON, SUN, AND CV ACCRETION DISKS

    International Nuclear Information System (INIS)

    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 (DN) 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 spinning, tilted CV DN systems cannot be described by a precessing ring or by a precessing rigid disk. We find that differential rotation and effects on the disk by the accretion stream must be addressed. Our analysis indicates that the best description of a retrogradely precessing spinning, tilted, CV DN accretion disk is a differentially rotating, tilted disk with an attached rotating, tilted ring located near the innermost disk annuli. In agreement with the observations and numerical simulations by others, we find that our numerically simulated CV DN accretion disks retrogradely precess as a unit. Our final, reduced expression for retrograde precession agrees well with our numerical simulation results and with selective observational systems that seem to have main-sequence secondaries. Our results suggest that a major source to retrograde precession is tidal torques like that by the Moon and the Sun on the Earth. In addition, these tidal torques should be common to a variety of systems where one member is spinning and tilted, regardless if

  1. Optical model and calibration of a sun tracker

    International Nuclear Information System (INIS)

    Volkov, Sergei N.; Samokhvalov, Ignatii V.; Cheong, Hai Du; Kim, Dukhyeon

    2016-01-01

    Sun trackers are widely used to investigate scattering and absorption of solar radiation in the Earth's atmosphere. We present a method for optimization of the optical altazimuth sun tracker model with output radiation direction aligned with the axis of a stationary spectrometer. The method solves the problem of stability loss in tracker pointing at the Sun near the zenith. An optimal method for tracker calibration at the measurement site is proposed in the present work. A method of moving calibration is suggested for mobile applications in the presence of large temperature differences and errors in the alignment of the optical system of the tracker. - Highlights: • We present an optimal optical sun tracker model for atmospheric spectroscopy. • The problem of loss of stability of tracker pointing at the Sun has been solved. • We propose an optimal method for tracker calibration at a measurement site. • Test results demonstrate the efficiency of the proposed optimization methods.

  2. Development of a Meso-Scale Fiberoptic Rotation Sensor for a Torsion Actuator.

    Science.gov (United States)

    Sheng, Jun; Desai, Jaydev P

    2018-01-01

    This paper presents the development of a meso-scale fiberoptic rotation sensor for a shape memory alloy (SMA) torsion actuator for neurosurgical applications. Within the sensor, a rotary head with a reflecting surface is capable of modulating the light intensity collected by optical fibers when the rotary head is coupled to the torsion actuator. The mechanism of light intensity modulation is modeled, followed by experimental model verification. Meanwhile, working performances for different rotary head designs, optical fibers, and fabrication materials are compared. After the calibration of the fiberoptic rotation sensor, the sensor is capable of precisely measuring rotary motion and controlling the SMA torsion actuator with feedback control.

  3. Diffusion of helium in the Sun

    Energy Technology Data Exchange (ETDEWEB)

    Noerdlinger, P D [Michigan State Univ., East Lansing (USA). Dept. of Astronomy and Astrophysics; Amsterdam Univ. (Netherlands). Sterrenkundig Instituut)

    1977-05-01

    I have reduced the set of diffusion and flow equations developed by Burgers for a multi-component gas to a workable scheme for the actual evaluation of the relative diffusion of hydrogen and helium in stars. Previous analyses have used the Aller and Chapman equations, which apply only to trace constitutents and whose coefficients are not believed to be as accurate as Burgers'. Furthermore, the resulting equations have been combined consistently with Paczynski's stellar evolution code to demonstrate small but significant effects in the Sun, from the thermal and gravitational settling of Helium. The core helium content of a 1 M star goes up about 0.04 and the surface helium content down by about -0.03 in 4.5 10/sup 9/ years. The results are still somewhat uncertain because of uncertainties in the underlying plasma physics, and further research is suggested. In any case, the diffusion process speeds up with time, due to increased temperature gradient, and it will be of interest to follow the process in older stars and in later stellar evolution.

  4. Advances in Sun-Earth Connection Modeling

    International Nuclear Information System (INIS)

    Ganguli, S.B.; Gavrishchaka, V.V.

    2003-01-01

    Space weather forecasting is a focus of a multidisciplinary research effort motivated by a sensitive dependence of many modern technologies on geospace conditions. Adequate understanding of the physics of the Sun-Earth connection and associated multi-scale magnetospheric and ionospheric processes is an essential part of this effort. Modern physical simulation models such as multimoment multifluid models with effective coupling from small-scale kinetic processes can provide valuable insight into the role of various physical mechanisms operating during geomagnetic storm/substorm activity. However, due to necessary simplifying assumptions, physical models are still not well suited for accurate real-time forecasting. Complimentary approach includes data-driven models capable of efficient processing of multi-scale spatio-temporal data. However, the majority of advanced nonlinear algorithms, including neural networks (NN), can encounter a set of problems called dimensionality curse when applied to high-dimensional data. Forecasting of rare/extreme events such as large geomagnetic storms/substorms is of the most practical importance but is also very challenging for many existing models. A very promising algorithm that combines the power of the best nonlinear techniques and tolerance to high-dimensional and incomplete data is support vector machine (SVM). We have summarized advantages of the SVM and described a hybrid model based on SVM and extreme value theory (EVT) for rare event forecasting. Results of the SVM application to substorm forecasting and future directions are discussed

  5. 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...

  6. Neutrino propagation in a fluctuating sun

    International Nuclear Information System (INIS)

    Burgess, C.P.; Michaud, D.

    1997-01-01

    We adapt to neutrino physics a general formulation for particle propagation in fluctuating media, initially developed for applications to electromagnetism and neutron optics. In leading approximation this formalism leads to the usual MSW effective Hamiltonian governing neutrino propagation through a medium. Next-to-leading contributions describe deviations from this description, which arise due to neutrino interactions with fluctuations in the medium. We compute these corrections for two types of fluctuations: (i) microscopic thermal fluctuations and (ii) macroscopic fluctuations in the medium s density. While the first of these reproduces standard estimates, which are negligible for applications to solar neutrinos, we find that the second can be quite large, since it grows in size with the correlation length of the fluctuation. We consider two models in some detail. For fluctuations whose correlations extend only over a local region in space of length l, appreciable effects for MSW oscillations arise if (δn/n) 2 l approx-gt 100m or so. Alternatively, a crude model of helioseismic p-waves gives appreciable effects only when (δn/n)approx-gt 1%. In general the dominant effect is to diminish the quality of the resonance, making the suppression of the 7 Be neutrinos a good experimental probe of fluctuations deep within the sun. Fluctuations can also provide a new mechanism for reducing the solar neutrino flux, giving an energy-independent suppression factor of 1/2 away from the resonant region, even for small vacuum mixing angles. copyright 1997 Academic Press, Inc

  7. Open magnetic structures on the sun

    International Nuclear Information System (INIS)

    Levine, R.H.; Altschuler, M.D.; Harvey, J.W.; Jackson, B.V.

    1977-01-01

    High-resolution harmonic analysis of the solar magnetic field has been used successfully to calculate the geometry of open magnetic field lines in the solar corona. Comparison of the loci of open field line footpoints with solar X-ray photographs shows that all of the coronal holes during two solar rotations are successfully represented, including details of their evolution. Some open magnetic configurations derived in the calculations precede by up to one solar rotation the manifestation of coincident dark areas on the X-ray photographs. The only other areas that contribute open field lines to the corona are separations between active-region loop systems. By varying the radius at which field lines are forced to be open in the calculation, it is possible to more closely reproduce the surface configuration of particular coronal holes. Comparison of the size of X-ray holes with the fraction of the solar surface covered by open field lines leads to the conclusion that a significant part of the area of coronal holes must contain closed magnetic fields. Comparison of open field lines which lie in the equatorial plane of the Sun with solar wind data indicates that eventual high-speed solar wind streams are associated with those parts of open magnetic structures that diverge the least. Several important questions raised by this study are under investigation using data for the entire Skylab period

  8. Mediation analysis of decisional balance, sun avoidance and sunscreen use in the precontemplation and preparation stages for sun protection.

    Science.gov (United States)

    Santiago-Rivas, Marimer; Velicer, Wayne F; Redding, Colleen

    2015-01-01

    Mediation analyses of sun protection were conducted testing structural equation models using longitudinal data with three waves. An effect was said to be mediated if the standardised path between processes of change, decisional balance and sun protection outcomes was significant. Longitudinal models of sun protection using data from individuals in the precontemplation (N = 964) and preparation (N = 463) stages who participated of an expert system intervention. Nine processes of change for sun protection, decisional balance constructs of sun protection (pros and cons), sun avoidance behaviour and sunscreen use. With the exception of two processes in the preparation stage, processes of change predicted the pros (r = .126-.614), and the pros predicted the outcomes (r = .181-.272). Three models with the cons as mediator in the preparation stage, and none in the precontemplation stage, showed a mediated relationship between processes and outcomes. In general, mediation analyses found both the process of change-to-pros and pros-to-behaviour paths significant for both precontemplation and preparation stages, and for both sun avoidance and sunscreen use outcomes. Findings provide support for the importance of assessing the role of underlying risk cognitions in improving sun protection adherence.

  9. 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…

  10. Java-based mobile agent platforms for wireless sensor networks

    NARCIS (Netherlands)

    Aiello, F.; Carbone, A.; Fortino, G.; Galzarano, S.; Ganzha, M.; Paprzycki, M.

    2010-01-01

    This paper proposes an overview and comparison of mobile agent platforms for the development of wireless sensor network applications. In particular, the architecture, programming model and basic performance of two Java-based agent platforms, Mobile Agent Platform for Sun SPOT (MAPS) and Agent

  11. Femoral head avascular necrosis

    International Nuclear Information System (INIS)

    Chrysikopoulos, H.; Sartoris, D.J.; Resnick, D.L.; Ashburn, W.; Pretorius, T.

    1988-01-01

    MR imaging has been shown to be more sensitive and specific than planar scintigraphy for avascular necrosis (AVN) of the femoral head. However, experience with single photon emission CT (SPECT) is limited. The authors retrospectively compared 1.5-T MR imaging with SPECT in 14 patients with suspected femoral head AVN. Agreement between MR imaging and SPECT was present in 24 femurs, 14 normal and ten with AVN. MR imaging showed changes of AVN in the remaining four femoral heads. Of these, one was normal and the other three inconclusive for AVN by SPECT. The authors conclude that MR imaging is superior to SPECT for the evaluation of AVN of the hip

  12. Using Priors to Compensate Geometrical Problems in Head-Mounted Eye Trackers

    DEFF Research Database (Denmark)

    Batista Narcizo, Fabricio; Ahmed, Zaheer; Hansen, Dan Witzner

    The use of additional information (a.k.a. priors) to help the eye tracking process is presented as an alternative to compensate classical geometrical problems in head-mounted eye trackers. Priors can be obtained from several distinct sources, such as: sensors to collect information related...... estimation specially for uncalibrated head-mounted setups....

  13. Sun Glint Correction of High and Low Spatial Resolution Images of Aquatic Scenes: a Review of Methods for Visible and Near-Infrared Wavelengths

    Directory of Open Access Journals (Sweden)

    Susan Kay

    2009-10-01

    Full Text Available Sun glint, the specular reflection of light from water surfaces, is a serious confounding factor for remote sensing of water column properties and benthos. This paper reviews current techniques to estimate and remove the glint radiance component from imagery. Methods for processing of ocean color images use statistical sea surface models to predict the glint from the sun and sensor positions and wind data. Methods for higher resolution imaging, used in coastal and shallow water mapping, estimate the glint radiance from the near-infrared signal. The effects of some current methods are demonstrated and possibilities for future techniques are briefly addressed.

  14. Automotive sensors

    Science.gov (United States)

    Marek, Jiri; Illing, Matthias

    2003-01-01

    Sensors are an essential component of most electronic systems in the car. They deliver input parameters for comfort features, engine and emission control as well as for the active and passive safety systems. New technologies such as silicon micromachining play an important role for the introduction of these sensors in all vehicle classes. The importance and use of these sensor technologies in today"s automotive applications will be shown in this article. Finally an outlook on important current developments and new functions in the car will be given.

  15. Piezoceramic Sensors

    CERN Document Server

    Sharapov, Valeriy

    2011-01-01

    This book presents the latest and complete information about various types of piezosensors. A sensor is a converter of the measured physical size to an electric signal. Piezoelectric transducers and sensors are based on piezoelectric effects. They have proven to be versatile tools for the measurement of various processes. They are used for quality assurance, process control and for research and development in many different industries. In each area of application specific requirements to the parameters of transducers and sensors are developed. This book presents the fundamentals, technical des

  16. ACTIVITY-BRIGHTNESS CORRELATIONS FOR THE SUN AND SUN-LIKE STARS

    International Nuclear Information System (INIS)

    Preminger, D. G.; Chapman, G. A.; Cookson, A. M.

    2011-01-01

    We analyze the effect of solar features on the variability of the solar irradiance in three different spectral ranges. Our study is based on two solar-cycles' worth of full-disk photometric images from the San Fernando Observatory, obtained with red, blue, and Ca II K-line filters. For each image we measure the photometric sum, Σ, which is the relative contribution of solar features to the disk-integrated intensity of the image. The photometric sums in the red and blue continuum, Σ r and Σ b , exhibit similar temporal patterns: they are negatively correlated with solar activity, with strong short-term variability, and weak solar-cycle variability. However, the Ca II K-line photometric sum, Σ K , is positively correlated with solar activity and has strong variations on solar-cycle timescales. We show that we can model the variability of the Sun's bolometric flux as a linear combination of Σ r and Σ K . We infer that, over solar-cycle timescales, the variability of the Sun's bolometric irradiance is directly correlated with spectral line variability, but inversely correlated with continuum variability. Our blue and red continuum filters are quite similar to the Stroemgren b and y filters used to measure stellar photometric variability. We conclude that active stars whose visible continuum brightness varies inversely with activity, as measured by the Ca HK index, are displaying a pattern that is similar to that of the Sun, i.e., radiative variability in the visible continuum that is spot-dominated.

  17. 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.

  18. Ineffectiveness of sun awareness posters in dermatology clinics.

    Science.gov (United States)

    Jung, G W; Senthilselvan, A; Salopek, T G

    2010-06-01

    Although sun awareness posters have been used in doctors' offices and clinics for decades to promote sun protective behaviour, there is no evidence of their usefulness. To investigate whether sun awareness posters lead to inquiry of skin cancer and sun protection measures. Patients considered at risk for skin cancer seen at a dermatology clinic were randomly asked to complete a questionnaire designed to assess the effectiveness of three different sun awareness posters placed in patient rooms. The posters were selected on the basis of their catchy slogan and eye-appealing images, and included those featuring parental interest, sex appeal and informative advice. Only half of the patients noticed the posters (50.6%). The poster with sex appeal garnered the most attention (67.8%), followed by the informative poster (49.2%) and the parental interest poster (35.8%) (P poster inquired about cutaneous cancers and sun protection practices twice as often as those who did not notice the poster, only one-tenth of such inquiries were attributed to the poster ( approximately 5% of the target population). As reported in the questionnaire, the posters themselves were less effective than the advice of physicians in influencing patient attitudes towards sun protection measures. Organizations that produce and disseminate posters should consider beyond focus groups when they design their posters and should consider field testing their products to ensure that they are reaching the targeted audience and are having the expected beneficial effect, otherwise their posters are simply decorative.

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

    Science.gov (United States)

    McLeod, Geraldine F H; Reeder, Anthony I; Gray, Andrew R; McGee, Rob

    2017-01-01

    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.

  20. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... you! Do you have a personal story about radiology? Share your patient story here Images × Image Gallery ... Pregnancy Head and Neck Cancer X-ray, Interventional Radiology and Nuclear Medicine Radiation Safety Images related to ...

  1. Exploding head syndrome.

    Science.gov (United States)

    Sharpless, Brian A

    2014-12-01

    Exploding head syndrome is characterized by the perception of abrupt, loud noises when going to sleep or waking up. They are usually painless, but associated with fear and distress. In spite of the fact that its characteristic symptomatology was first described approximately 150 y ago, exploding head syndrome has received relatively little empirical and clinical attention. Therefore, a comprehensive review of the scientific literature using Medline, PsycINFO, Google Scholar, and PubMed was undertaken. After first discussing the history, prevalence, and associated features, the available polysomnography data and five main etiological theories for exploding head syndrome are summarized. None of these theories has yet reached dominance in the field. Next, the various methods used to assess and treat exploding head syndrome are discussed, as well as the limited outcome data. Finally, recommendations for future measure construction, treatment options, and differential diagnosis are provided. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... medically necessary because of potential risk to the baby. This risk is, however, minimal with head CT ... intravenous contrast indicate mothers should not breastfeed their babies for 24-48 hours after contrast medium is ...

  3. Early Head Start Evaluation

    Data.gov (United States)

    U.S. Department of Health & Human Services — Longitudinal information from an evaluation where children were randomly assigned to Early Head Start or community services as usual;direct assessments and...

  4. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... top of page Additional Information and Resources RTAnswers.org Radiation Therapy for Brain Tumors Radiation Therapy for ... Tomography (CT) - Head Sponsored by Please note RadiologyInfo.org is not a medical facility. Please contact your ...

  5. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... of the Head? Computed tomography, more commonly known as a CT or CAT scan, is a diagnostic ... white on the x-ray; soft tissue, such as organs like the heart or liver, shows up ...

  6. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... microphone. top of page How does the procedure work? In many ways CT scanning works very much ... head CT scanning. Manufacturers of intravenous contrast indicate mothers should not breastfeed their babies for 24-48 ...

  7. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... rays). top of page What are some common uses of the procedure? CT scanning of the head ... is done because a potential abnormality needs further evaluation with additional views or a special imaging technique. ...

  8. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... rays). top of page What are some common uses of the procedure? CT scanning of the head ... community, you can search the ACR-accredited facilities database . This website does not provide cost information. The ...

  9. Head Start Impact Study

    Data.gov (United States)

    U.S. Department of Health & Human Services — Nationally representative, longitudinal information from an evaluation where children were randomly assigned to Head Start or community services as usual;direct...

  10. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... Stroke Brain Tumors Computer Tomography (CT) Safety During Pregnancy Head and Neck Cancer X-ray, Interventional Radiology and Nuclear Medicine Radiation Safety Images related to Computed Tomography (CT) - ...

  11. TCGA head Neck

    Science.gov (United States)

    Investigators with The Cancer Genome Atlas (TCGA) Research Network have discovered genomic differences – with potentially important clinical implications – in head and neck cancers caused by infection with the human papillomavirus (HPV).

  12. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... your doctor to evaluate your face, sinuses, and skull or to plan radiation therapy for brain cancer. ... typically used to detect: bleeding, brain injury and skull fractures in patients with head injuries. bleeding caused ...

  13. 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.

  14. Sun protection among Spanish beachgoers: knowledge, attitude and behaviour.

    Science.gov (United States)

    Cercato, M C; Ramazzotti, V; Sperduti, I; Asensio-Pascual, A; Ribes, I; Guillén, C; Nagore, E

    2015-03-01

    This study aims to investigate the level of awareness on the risks related to sun exposure, attitude towards sun protection and sun protection behaviour in Spanish beachgoers. During the summer of 2009, trained assistants conducted a structured interview with 630 sunbathers at the beaches of Valencia, Spain, via administrating a questionnaire including the following: (a) general data (age, gender, education, profession), (b) "knowledge" and "attitude" items and (c) self-assessed sun sensitivity, sun exposure and sun protection characteristics. The health belief model was used to evaluate factors that may influence on engaging healthy behaviour. The median age was 30 (2-82) years; the M/F ratio was 0.60. Despite the widespread regular ("often" or "always", 80%) use of high (>15) sun-protective factor sunscreens, current recommendations on sun protection were not regularly followed, and a history of sunburns is very common (70%). At multivariate analysis, female gender, age, fair hair, freckles, all-day use of sunscreens and wearing sunglasses were independent factors associated with having sunburn history. A high knowledge and a fairly good attitude emerged (median scores, 6/7 and 22/30, respectively). Age class (p = 0.032), educational level (p < 0.0001), sunscreen use (p = 0.048) and adequate timing of the first application of sunscreens (p = 0.015) were predictors of awareness, while factors associated with a more favourable attitude were educational level (p < 0.0001) and regular use of hats (p = 0.001). Wrong beliefs mainly concern sunscreens (false safety); the attractiveness of a tanned look is the main unfavourable attitude. Physical and motivational barriers are common (80%). The findings by highlighting constitutional and psychosocial factors involved in unhealthy behaviour provide useful information to promote sun-safe interventions in this population.

  15. The exploding head syndrome.

    Science.gov (United States)

    Green, M W

    2001-06-01

    This article reviews the features of an uncommon malady termed "the exploding head syndrome." Sufferers describe terrorizing attacks of a painless explosion within their head. Attacks tend to occur at the onset of sleep. The etiology of attacks is unknown, although they are considered to be benign. Treatment with clomipramine has been suggested, although most sufferers require only reassurance that the spells are benign in nature.

  16. Adaptive algorithm of magnetic heading detection

    Science.gov (United States)

    Liu, Gong-Xu; Shi, Ling-Feng

    2017-11-01

    Magnetic data obtained from a magnetic sensor usually fluctuate in a certain range, which makes it difficult to estimate the magnetic heading accurately. In fact, magnetic heading information is usually submerged in noise because of all kinds of electromagnetic interference and the diversity of the pedestrian’s motion states. In order to solve this problem, a new adaptive algorithm based on the (typically) right-angled corridors of a building or residential buildings is put forward to process heading information. First, a 3D indoor localization platform is set up based on MPU9250. Then, several groups of data are measured by changing the experimental environment and pedestrian’s motion pace. The raw data from the attached inertial measurement unit are calibrated and arranged into a time-stamped array and written to a data file. Later, the data file is imported into MATLAB for processing and analysis using the proposed adaptive algorithm. Finally, the algorithm is verified by comparison with the existing algorithm. The experimental results show that the algorithm has strong robustness and good fault tolerance, which can detect the heading information accurately and in real-time.

  17. GPK heading machine

    Energy Technology Data Exchange (ETDEWEB)

    Krmasek, J.; Novosad, K.

    1981-01-01

    This article evaluates performance tests of the Soviet made GPK heading machine carried out in 4 coal mines in Czechoslovakia (Ostrava-Karvina region and Kladno mines). GPK works in coal seams and rocks with compression strength of 40 to 50 MPa. Dimensions of the tunnel are height 1.8 to 3.8 m and width 2.6 to 4.7 m, tunnel gradient plus to minus 10 degrees. GPK weighs 16 t, its conical shaped cutting head equipped with RKS-1 cutting tools is driven by an electric motor with 55 kW capacity. Undercarriage of the GPK, gathering-arm loader, hydraulic system, electric system and dust supression system (water spraying or pneumatic section) are characterized. Specifications of GPK heading machines are compared with PK-3r and F8 heading machines. Reliability, number of failures, dust level, noise, productivity depending on compression strength of rocks, heading rate in coal and in rocks, energy consumption, performance in inclined tunnels, and cutting tool wear are evaluated. Tests show that GPK can be used to drive tunnels in coal with rock constituting up to 50% of the tunnel crosscut, as long as rock compression strength does not exceed 50 MPa. In rocks characterized by higher compression strength cutting tool wear sharply increases. GPK is characterized by higher productivity than that of the PK-3r heading machine. Among the weak points of the GPK are: unsatisfactory reliability and excessive wear of its elements. (4 refs.) (In Czech)

  18. [Buddhist influences on Sun Simiao's precious prescriptions for emergency].

    Science.gov (United States)

    Zhu, J

    1999-10-01

    Living in a period when the Buddhism was quite flourishing, Sun had a close contact with the monk Dao Xuan, the founder of Nanshan Sect Buddhism. Sun's Quian jin fang adopted all schools including Buddhism, evidenced by the following 3 aspects: 1) Direct Buddhist influence, mainly on medical morality; 2) Indian medicine coming together with Buddhism, including the theory of "four - element theory", the conception of all matters are medicines, pills of all disorders, recipes, and keep - fit art. Buddhism acts as a carrier here; 3) the achievements of treatment for beriberi by monks. However, Buddhist influence was far inferior to Taoism as far as Sun's work is concerned.

  19. 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

  20. 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

  1. Evidence for continuum absorption above the quiet sun transition region

    International Nuclear Information System (INIS)

    Schmahl, E.J.; Orrall, F.Q.

    1979-01-01

    We report new evidence for continuum absorption in the solar transition zone in EUV spectra obtained from OSO 4, OSO 6, ATM, and full Sun measurements. This absorption shortward of 912 A is manifest everywhere on the Sun's disk. It is present within network cells and boundaries of the quiet Sun, in coronal holes, in active regions, above the limb, and in solar prominences. Models of the upper chromosphere and the transition zone must be modified to include an admixture of neutral hydrogen (or possibly singly ionized helium) with the hotter plasma

  2. 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.

  3. 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

  4. The Sun as a system of elementary particles

    International Nuclear Information System (INIS)

    Kleczek, J.

    1986-01-01

    The paper based on known facts of solar physics-is an attempt to interpret the Sun as a selfgravitating system of about 10/sup 57/ nucleons and electrons. These elementary particles are endowed with strong, electromagnetic, weak and gravitational interactions. Origin of the Sun, its evolution, structure and physiology are consequences of the four interactions. Each structural property, every evolutionary process, any activity phenomenon or event on the Sun can be traced backwards to the four fundamental forces of nature, viz. to interactions of elementary particles

  5. Preferred solar wind emitting longitudes on the sun

    International Nuclear Information System (INIS)

    Gosling, J.T.; Asbridge, J.R.; Bame, S.J.; Feldman, W.C.

    1977-01-01

    During the 11 1/2-year period from July 1964 through December 1975, high- and low-speed solar wind flows originated from preferred solar longitudes. The preferred longitude effect was most pronounced from 1970 onward but was also evident in the years preceding 1970. The most pronounced modulation in average solar wind speed with longitude (approximately 20%) was obtained when it was assumed that the synodic rotation period of the sun is 27.025 days. Some deep internal structure in the sun must ultmately be responsible for these long-lived longitudinal effects, which appear to rotate rigidly with the sun

  6. 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.

  7. Optischer Sensor

    OpenAIRE

    Brandenburg, A.; Hutter, F.; Edelhaeuser, R.

    1992-01-01

    WO 2010040565 A1 UPAB: 20100506 NOVELTY - The integrated optical sensor comprises a first waveguide (4), a second waveguide (5) optically coupled to the first waveguide via a directional coupler, a substrate, which carries the first and the second waveguides, a single waveguide coupled with a light source, and an output waveguide coupled with a light-sensitive element. The sensor has a functional surface in the region of the directional coupler for depositing or deposition of the substance to...

  8. Wireless sensor

    Science.gov (United States)

    Lamberti, Vincent E.; Howell, JR, Layton N.; Mee, David K.; Sepaniak, Michael J.

    2016-02-09

    Disclosed is a sensor for detecting a target material. The sensor includes a ferromagnetic metal and a molecular recognition reagent coupled to the ferromagnetic metal. The molecular recognition reagent is operable to expand upon exposure to vapor or liquid from the target material such that the molecular recognition reagent changes a tensile stress upon the ferromagnetic metal. The target material is detected based on changes in the magnetic switching characteristics of the ferromagnetic metal caused by the changes in the tensile stress.

  9. 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.

  10. SunFast: A sun workstation based, fuel analysis scoping tool for pressurized water reactors

    International Nuclear Information System (INIS)

    Bohnhoff, W.J.

    1991-05-01

    The objective of this research was to develop a fuel cycle scoping program for light water reactors and implement the program on a workstation class computer. Nuclear fuel management problems are quite formidable due to the many fuel arrangement options available. Therefore, an engineer must perform multigroup diffusion calculations for a variety of different strategies in order to determine an optimum core reload. Standard fine mesh finite difference codes result in a considerable computational cost. A better approach is to build upon the proven reliability of currently available mainframe computer programs, and improve the engineering efficiency by taking advantage of the most useful characteristic of workstations: enhanced man/machine interaction. This dissertation contains a description of the methods and a user's guide for the interactive fuel cycle scoping program, SunFast. SunFast provides computational speed and accuracy of solution along with a synergetic coupling between the user and the machine. It should prove to be a valuable tool when extensive sets of similar calculations must be done at a low cost as is the case for assessing fuel management strategies. 40 refs

  11. Orbit-attitude coupled motion around small bodies: Sun-synchronous orbits with Sun-tracking attitude motion

    Science.gov (United States)

    Kikuchi, Shota; Howell, Kathleen C.; Tsuda, Yuichi; Kawaguchi, Jun'ichiro

    2017-11-01

    The motion of a spacecraft in proximity to a small body is significantly perturbed due to its irregular gravity field and solar radiation pressure. In such a strongly perturbed environment, the coupling effect of the orbital and attitude motions exerts a large influence that cannot be neglected. However, natural orbit-attitude coupled dynamics around small bodies that are stationary in both orbital and attitude motions have yet to be observed. The present study therefore investigates natural coupled motion that involves both a Sun-synchronous orbit and Sun-tracking attitude motion. This orbit-attitude coupled motion enables a spacecraft to maintain its orbital geometry and attitude state with respect to the Sun without requiring active control. Therefore, the proposed method can reduce the use of an orbit and attitude control system. This paper first presents analytical conditions to achieve Sun-synchronous orbits and Sun-tracking attitude motion. These analytical solutions are then numerically propagated based on non-linear coupled orbit-attitude equations of motion. Consequently, the possibility of implementing Sun-synchronous orbits with Sun-tracking attitude motion is demonstrated.

  12. Magnetic Resonance Imaging (MRI) -- Head

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z Magnetic Resonance Imaging (MRI) - Head Magnetic resonance imaging (MRI) of the head uses a powerful ... the Head? What is MRI of the Head? Magnetic resonance imaging (MRI) is a noninvasive medical test that ...

  13. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... News Physician Resources Professions Site Index A-Z Magnetic Resonance Imaging (MRI) - Head Magnetic resonance imaging (MRI) of the head uses a powerful ... the Head? What is MRI of the Head? Magnetic resonance imaging (MRI) is a noninvasive medical test that ...

  14. Head, Neck, and Oral Cancer

    Medline Plus

    Full Text Available ... find out more. Oral, Head and Neck Pathology Oral, Head and Neck Pathology Close to 49,750 Americans will be diagnosed ... find out more. Oral, Head and Neck Pathology Oral, Head and Neck Pathology Close to 49,750 Americans will be diagnosed ...

  15. Head, Neck, and Oral Cancer

    Science.gov (United States)

    ... find out more. Oral, Head and Neck Pathology Oral, Head and Neck Pathology Close to 49,750 Americans will be diagnosed ... find out more. Oral, Head and Neck Pathology Oral, Head and Neck Pathology Close to 49,750 Americans will be diagnosed ...

  16. Sodium reflux pool-boiler solar receiver on-sun test results

    Energy Technology Data Exchange (ETDEWEB)

    Andraka, C E; Moreno, J B; Diver, R B; Moss, T A [Oak Ridge National Lab., TN (United States)

    1992-06-01

    The efficient operation of a Stirling engine requires the application of a high heat flux to the relatively small area occupied by the heater head tubes. Previous attempts to couple solar energy to Stirling engines generally involved directly illuminating the heater head tubes with concentrated sunlight. In this study, operation of a 75-kW{sub t} sodium reflux pool-boiler solar receiver has been demonstrated and its performance characterized on Sandia's nominal 75-kW{sub t} parabolic-dish concentrator, using a cold-water gas-gap calorimeter to simulate Stirling engine operation. The pool boiler (and more generally liquid-metal reflux receivers) supplies heat to the engine in the form of latent heat released from condensation of the metal vapor on the heater head tubes. The advantages of the pool boiler include uniform tube temperature, leading to longer life and higher temperature available to the engine, and decoupling of the design of the solar absorber from the engine heater head. The two-phase system allows high input thermal flux, reducing the receiver size and losses, therefore improving system efficiency. The receiver thermal efficiency was about 90% when operated at full power and 800{degree}C. Stable sodium boiling was promoted by the addition of 35 equally spaced artificial cavities in the wetted absorber surface. High incipient boiling superheats following cloud transients were suppressed passively by the addition of small amounts of xenon gas to the receiver volume. Stable boiling without excessive incipient boiling superheats was observed under all operating conditions. The receiver developed a leak during performance evaluation, terminating the testing after accumulating about 50 hours on sun. The receiver design is reported here along with test results including transient operations, steady-state performance evaluation, operation at various temperatures, infrared thermography, x-ray studies of the boiling behavior, and a postmortem analysis.

  17. VUV Spectroscopy of the Sun as a Star

    Science.gov (United States)

    Kankelborg, Charles; Philip, Judge; Winebarger, Amy R.; Kobayashi, Ken; Smart, Roy

    2017-08-01

    We describe a new sounding rocket mission to obtain the first high resolution, high quality VUV (100-200 nm) spectrum of the Sun-as-a-star. Our immediate science goal is to understand better the processes of chromospheric and coronal heating. HST data exist for a dozen or so Sun-like stars of a quality already beyond our ability to construct a comparable sun-as-a-star UV spectrum. The solar spectrum we obtain will enable us to understand the nature of magnetic energy dissipation as a Sun-like star evolves, and the dependence of magnetic activity on stellar mass and metallicity. This poster presents the instrument design, scientific prospects, and broader impacts of the proposed mission.

  18. Suns-VOC characteristics of high performance kesterite solar cells

    Science.gov (United States)

    Gunawan, Oki; Gokmen, Tayfun; Mitzi, David B.

    2014-08-01

    Low open circuit voltage (VOC) has been recognized as the number one problem in the current generation of Cu2ZnSn(Se,S)4 (CZTSSe) solar cells. We report high light intensity and low temperature Suns-VOC measurement in high performance CZTSSe devices. The Suns-VOC curves exhibit bending at high light intensity, which points to several prospective VOC limiting mechanisms that could impact the VOC, even at 1 sun for lower performing samples. These VOC limiting mechanisms include low bulk conductivity (because of low hole density or low mobility), bulk or interface defects, including tail states, and a non-ohmic back contact for low carrier density CZTSSe. The non-ohmic back contact problem can be detected by Suns-VOC measurements with different monochromatic illuminations. These limiting factors may also contribute to an artificially lower JSC-VOC diode ideality factor.

  19. Sun Tzu's War Theory in the Twenty First Century

    National Research Council Canada - National Science Library

    Kuo, Li-sheng A

    2007-01-01

    .... In accordance with "winning without fighting a battle" scenario, I will argue that the battle-prevention theory school is the most suitable, and Sun Tzu's classic The Art of War is the best choice of approach...

  20. Thermal evaluation of a sun tracking solar cooker

    Energy Technology Data Exchange (ETDEWEB)

    El-Tous, Yousif; Al-Mofleh, Anwar [Department of Electrical Engineering, Faculty of Engineering Technology, Al-Balqa' Applied University, P.O. Box 15008, Amman (Jordan); Badran, Omar. O. [Department of Mechanical Engineering, Faculty of Engineering Technology, Al-Balqa Appllied University, P.O. Box 15008, Amman (Jordan)

    2012-07-01

    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.

  1. Cassava Sun Drying Performance on Various Surfaces and Drying ...

    African Journals Online (AJOL)

    Traditional processing methods that include ... The traditional sun drying method is very inefficient as the product can take 2-. 3 days to dry. .... using a digital balance (Ohaus Corporation type). The same applied .... preservation and marketing.

  2. 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.

  3. The sun, the solar wind, and the heliosphere

    CERN Document Server

    Miralles, Mari Paz

    2011-01-01

    This volume presents a concise, up-to-date overview of current research on the observations, theoretical interpretations, and empirical and physical descriptions of the Sun, the Solar Wind, and the Heliosphere, from the solar interior outward to the planets.

  4. Modelling Structural Flexure Effects in CPV Sun Trackers

    OpenAIRE

    Luque-Heredia, Ignacio; Quéméré, G.; Magalhães, P.H.; Fraile de Lerma, Alberto; Hermanns, Lutz Karl Heinz; Alarcón Álvarez, Enrique; Luque López, Antonio

    2006-01-01

    Nowadays CPV trends mostly based in lens parqueted flat modules, enable the separate design of the sun tracker. To enable this possibility a set of specifications is to be prescribed for the tracker design team, which take into account fundamental requisites such as the maximum service loads both permanent and variable, the sun tracking accuracy and the tracker structural stiffness required to maintain the CPV array acceptance angle loss below a certain threshold. In its first part this paper...

  5. The Sun was Not Born in M67

    Science.gov (United States)

    Pichardo, Bárbara; Moreno, Edmundo; Allen, Christine; Bedin, Luigi R.; Bellini, Andrea; Pasquini, Luca

    2012-03-01

    Using the most recent proper-motion determination of the old, solar-metallicity, Galactic open cluster M67 in orbital computations in a non-axisymmetric model of the Milky Way, including a bar and three-dimensional spiral arms, we explore the possibility that the Sun once belonged to this cluster. We have performed Monte Carlo numerical simulations to generate the present-day orbital conditions of the Sun and M67, and all the parameters in the Galactic model. We compute 3.5 × 105 pairs of orbits Sun-M67 looking for close encounters in the past with a minimum distance approach within the tidal radius of M67. In these encounters we find that the relative velocity between the Sun and M67 is larger than 20 km s-1. If the Sun had been ejected from M67 with this high velocity by means of a three-body encounter, this interaction would have either destroyed an initial circumstellar disk around the Sun or dispersed its already formed planets. We also find a very low probability, much lower than 10-7, that the Sun was ejected from M67 by an encounter of this cluster with a giant molecular cloud. This study also excludes the possibility that the Sun and M67 were born in the same molecular cloud. Our dynamical results convincingly demonstrate that M67 could not have been the birth cluster of our solar system. This work relies partly on observations of the Large Binocular Telescope (LBT). The LBT is an international collaboration among institutions in the United States, Italy, and Germany. LBT Corporation partners are The Ohio State University; The University of Arizona on behalf of the Arizona university system; Istituto Nazionale di Astrofisica, Italy; LBT Beteiligungsgesellschaft, Germany, representing the Max-Planck Society, the Astrophysical Institute Potsdam, and Heidelberg University; and The Research Corporation, on behalf of The University of Notre Dame, University of Minnesota, and University of Virginia.

  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.

  7. 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.

  8. Previous climatic alterations are caused by the sun

    International Nuclear Information System (INIS)

    Groenaas, Sigbjoern

    2003-01-01

    The article surveys the scientific results of previous research into the contribution of the sun to climatic alterations. The author concludes that there is evidence of eight cold periods after the last ice age and that the alterations largely were due to climate effects from the sun. However, these effects are only causing a fraction of the registered global warming. It is assumed that the human activities are contributing to the rest of the greenhouse effect

  9. 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)....

  10. Sun safety knowledge and practice in UK postal delivery workers

    OpenAIRE

    Houdmont, J.; Davis, S.; Griffiths, A.

    2015-01-01

    Background: Postal delivery workers spend a large proportion of their work time outdoors, placing them at increased risk for skin cancer. To date, no studies have examined occupational sun safety knowledge and practice within this group in the UK.\\ud Aims: To describe the occupational sun safety knowledge and practice of UK postal delivery workers and to investigate the association of demographic, personal and occupational factors with knowledge and practice in order to identify potential str...

  11. Pre-main-sequence evolution of the sun

    International Nuclear Information System (INIS)

    Gough, D.

    1980-01-01

    The phase of solar evolution after the dynamical collapse is considered. The physics of the Kelvin-Helmholtz phase of gravitational collapse is described, attention being given to the early stages of the star when it was completely convective. It is noted that subsequently, a radiative core developed and evolution was controlled by the rate at which heat can diffuse through it by radiative transfer. Since the study of the Kelvin-Helmholtz contraction alone does not give enough information regarding the state of the sun when it first settled down to approximate hydrostatic equilibrium, other stars are studied, and information on the sun is obtained by analogy. Many young solar-type stars, such as the T Tauri stars, are not in the completely convective Hayashi (1961) phase hence it is proposed that the sun was completely mixed soon after its formation, which has some bearing on the sun's chemical structure. It is suggested that the surface of the sun was very nonuniform compared with the photosphere of today. The simple solar evolution model presented gives a good guide to the general way in which the sun contracted to the main sequence

  12. 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.

  13. Developing a multipurpose sun tracking system using fuzzy control

    Energy Technology Data Exchange (ETDEWEB)

    Alata, Mohanad [Department of Mechanical Engineering, Jordan University of Science and Technology (JUST), PO Box 3030, Irbid 22110 (Jordan)]. E-mail: alata@just.edu.jo; Al-Nimr, M.A. [Department of Mechanical Engineering, Jordan University of Science and Technology (JUST), PO Box 3030, Irbid 22110 (Jordan); Qaroush, Yousef [Department of Mechanical Engineering, Jordan University of Science and Technology (JUST), PO Box 3030, Irbid 22110 (Jordan)

    2005-05-01

    The present work demonstrates the design and simulation of time controlled step sun tracking systems that include: one axis sun tracking with the tilted aperture equal to the latitude angle, equatorial two axis sun tracking and azimuth/elevation sun tracking. The first order Sugeno fuzzy inference system is utilized for modeling and controller design. In addition, an estimation of the insolation incident on a two axis sun tracking system is determined by fuzzy IF-THEN rules. The approach starts by generating the input/output data. Then, the subtractive clustering algorithm, along with least square estimation (LSE), generates the fuzzy rules that describe the relationship between the input/output data of solar angles that change with time. The fuzzy rules are tuned by an adaptive neuro-fuzzy inference system (ANFIS). Finally, an open loop control system is designed for each of the previous types of sun tracking systems. The results are shown using simulation and virtual reality. The site of application is chosen at Amman, Jordan (32 deg. North, 36 deg. East), and the period of controlling and simulating each type of tracking system is the year 2003.

  14. Sun behaviour on the beach monitored by webcam photos.

    Science.gov (United States)

    Heerfordt, I M; Philipsen, P A; Wulf, H C

    2018-02-01

    To prevent skin cancer, the general population is recommended to limit time in the sun, to wear clothes and to seek shade around noon. This study aimed to investigate the number of beachgoers, the duration of sun exposure, and clothing worn during the day on a beach in Copenhagen. Observational, descriptive study. On 11 beach days in 2014 and 2015, beachgoers were counted every hour from 8:00 to 20:00. It was noted if they wore clothes or swimwear. To estimate the duration of sun exposure, it was noted how long cars were parked by the beach. Of the counted beachgoers 46% were present from noon to 15:00. The number of beachgoers peaked at 15:00 on weekend days (Saturdays and Sunday) and at 16:00 on working days (Monday to Friday). Both on weekend days and working days, the percentage of beachgoers wearing clothes was lowest at 13:00 when about 90% wore only swimwear. Cars were parked for 117 min on average. Around noon, the mean time expanded to 142 min. We assume this to reflect the duration of a beach visit. The results indicate a weak tendency to limit time in the sun and to seek shade when the ultraviolet radiation is strongest in the midday sun. Hopefully information about actual sun behaviour can be used to adjust campaigns. Copyright © 2017 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

  15. Sun safety in construction: a U.K. intervention study.

    Science.gov (United States)

    Houdmont, J; Madgwick, P; Randall, R

    2016-01-01

    Interventions to promote sun safety in the U.K. construction sector are warranted given the high incidence of skin cancer attributable to sun exposure relative to other occupational groups. To evaluate change in sun safety knowledge and practices among construction workers in response to an educational intervention. A baseline questionnaire was administered, followed by a bespoke sector-specific DVD-based intervention. At 12-month follow-up, participants completed a further questionnaire. Analyses were conducted on a sample of 120 workers (intervention group, n = 70; comparison group, n = 50). At follow-up, the proportion of intervention group participants that reported correct sun safety knowledge was not significantly greater than at baseline. However, the intervention group demonstrated significant positive change on 9 out of 10 behavioural measures, the greatest change being use of a shade/cover when working in the sun followed by regularly checking skin for moles or unusual changes. Exposure to this intervention was linked to some specific positive changes in construction workers' self-reported sun safety practices. These findings highlight the potential for educational interventions to contribute to tackling skin cancer in the UK construction sector. The findings support the development of bespoke educational interventions for other high-risk outdoor worker groups. © The Author 2015. Published by Oxford University Press on behalf of the Society of Occupational Medicine. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  16. 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.

  17. The sun as a star: Solar phenomena and stellar applications

    International Nuclear Information System (INIS)

    Noyes, R.W.

    1981-01-01

    Our Sun is a run-of-the-mill star, having no obvious extremes of stellar properties. For this reason it is perhaps more, rather than less, interesting as an astrophysical object, for its sameness to other stars suggests that in studying the Sun, we are studying at close hand common, rather than unusual stellar phenomena. Conversely, comparative study of the Sun and other solar-type stars is an invaluable tool for solar physics, for two reasons: First, it allows us to explore how solar properties and phenomena depend on parameters we cannot vary on the Sun - most fundamentally, rotation rate and mass. Second, study of solar-like stars of different ages allows us to see how stellar and solar phenomena depend on age; study of other stars may be one of the best ways to infer the earlier history of the Sun, as well as its future history. In this review we shall concentrate on phenomena common to the Sun and solar-type (main sequence) stars with different fundamental properties such as mass, age, and rotation. (orig.)

  18. Remote sensing of atmospheric optical depth using a smartphone sun photometer.

    Directory of Open Access Journals (Sweden)

    Tingting Cao

    Full Text Available In recent years, smart phones have been explored for making a variety of mobile measurements. Smart phones feature many advanced sensors such as cameras, GPS capability, and accelerometers within a handheld device that is portable, inexpensive, and consistently located with an end user. In this work, a smartphone was used as a sun photometer for the remote sensing of atmospheric optical depth. The top-of-the-atmosphere (TOA irradiance was estimated through the construction of Langley plots on days when the sky was cloudless and clear. Changes in optical depth were monitored on a different day when clouds intermittently blocked the sun. The device demonstrated a measurement precision of 1.2% relative standard deviation for replicate photograph measurements (38 trials, 134 datum. However, when the accuracy of the method was assessed through using optical filters of known transmittance, a more substantial uncertainty was apparent in the data. Roughly 95% of replicate smart phone measured transmittances are expected to lie within ±11.6% of the true transmittance value. This uncertainty in transmission corresponds to an optical depth of approx. ±0.12-0.13 suggesting the smartphone sun photometer would be useful only in polluted areas that experience significant optical depths. The device can be used as a tool in the classroom to present how aerosols and gases effect atmospheric transmission. If improvements in measurement precision can be achieved, future work may allow monitoring networks to be developed in which citizen scientists submit acquired data from a variety of locations.

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

    International Nuclear Information System (INIS)

    Chaudhari, V.A.; Solanki, C.S.

    2009-01-01

    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 un optimized 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

  20. Radiation sensor

    International Nuclear Information System (INIS)

    Brown, W.L.; Geronime, R.L.

    1977-01-01

    Radiation sensor and thermocouple, respectively, which can be used for reactor in-core instrumentation. The radiation sensor consists of an inconel conductor wire and rhodium emitter wire, the thermocouple of two intertwined alumel or chromel wires. Both are arranged in the center of a metal tube relative to which they are separated by an insulator made of SiO 2 fibers. This insulator is first introduced as a loose fabric between the radiation sensor and the thermocouple, respectively, and the metal tube and then compacted to a density of 35-73% of pure SiO 2 by drawing the tube. There is no need for soldering or welding. The insulation resistivity at room temperature ist between 10 14 and 10 15 ohms. (ORU) [de

  1. Water Sensors

    Science.gov (United States)

    1992-01-01

    Mike Morris, former Associate Director of STAC, formed pHish Doctor, Inc. to develop and sell a pH monitor for home aquariums. The monitor, or pHish Doctor, consists of a sensor strip and color chart that continually measures pH levels in an aquarium. This is important because when the level gets too high, ammonia excreted by fish is highly toxic; at low pH, bacteria that normally break down waste products stop functioning. Sales have run into the tens of thousands of dollars. A NASA Tech Brief Technical Support Package later led to a salt water version of the system and a DoE Small Business Innovation Research (SBIR) grant for development of a sensor for sea buoys. The company, now known as Ocean Optics, Inc., is currently studying the effects of carbon dioxide buildup as well as exploring other commercial applications for the fiber optic sensor.

  2. Sun and aureole spectrometer for airborne measurements to derive aerosol optical properties.

    Science.gov (United States)

    Asseng, Hagen; Ruhtz, Thomas; Fischer, Jürgen

    2004-04-01

    We have designed an airborne spectrometer system for the simultaneous measurement of the direct Sun irradiance and aureole radiance. The instrument is based on diffraction grating spectrometers with linear image sensors. It is robust, lightweight, compact, and reliable, characteristics that are important for airborne applications. The multispectral radiation measurements are used to derive optical properties of tropospheric aerosols. We extract the altitude dependence of the aerosol volume scattering function and of the aerosol optical depth by using flight patterns with descents and ascents ranging from the surface level to the top of the boundary layer. The extinction coefficient and the product of single scattering albedo and phase function of separate layers can be derived from the airborne measurements.

  3. Head first Ajax

    CERN Document Server

    Riordan, Rebecca M

    2008-01-01

    Ajax is no longer an experimental approach to website development, but the key to building browser-based applications that form the cornerstone of Web 2.0. Head First Ajax gives you an up-to-date perspective that lets you see exactly what you can do -- and has been done -- with Ajax. With it, you get a highly practical, in-depth, and mature view of what is now a mature development approach. Using the unique and highly effective visual format that has turned Head First titles into runaway bestsellers, this book offers a big picture overview to introduce Ajax, and then explores the use of ind

  4. Head First Statistics

    CERN Document Server

    Griffiths, Dawn

    2009-01-01

    Wouldn't it be great if there were a statistics book that made histograms, probability distributions, and chi square analysis more enjoyable than going to the dentist? Head First Statistics brings this typically dry subject to life, teaching you everything you want and need to know about statistics through engaging, interactive, and thought-provoking material, full of puzzles, stories, quizzes, visual aids, and real-world examples. Whether you're a student, a professional, or just curious about statistical analysis, Head First's brain-friendly formula helps you get a firm grasp of statistics

  5. Audiovisual Head Orientation Estimation with Particle Filtering in Multisensor Scenarios

    Directory of Open Access Journals (Sweden)

    Javier Hernando

    2007-07-01

    Full Text Available This article presents a multimodal approach to head pose estimation of individuals in environments equipped with multiple cameras and microphones, such as SmartRooms or automatic video conferencing. Determining the individuals head orientation is the basis for many forms of more sophisticated interactions between humans and technical devices and can also be used for automatic sensor selection (camera, microphone in communications or video surveillance systems. The use of particle filters as a unified framework for the estimation of the head orientation for both monomodal and multimodal cases is proposed. In video, we estimate head orientation from color information by exploiting spatial redundancy among cameras. Audio information is processed to estimate the direction of the voice produced by a speaker making use of the directivity characteristics of the head radiation pattern. Furthermore, two different particle filter multimodal information fusion schemes for combining the audio and video streams are analyzed in terms of accuracy and robustness. In the first one, fusion is performed at a decision level by combining each monomodal head pose estimation, while the second one uses a joint estimation system combining information at data level. Experimental results conducted over the CLEAR 2006 evaluation database are reported and the comparison of the proposed multimodal head pose estimation algorithms with the reference monomodal approaches proves the effectiveness of the proposed approach.

  6. Practical Use Technique of Sensor

    International Nuclear Information System (INIS)

    Hwang, Gyu Seop

    1985-11-01

    This book tells of practical use technology of sensor, introducing the recent trend of sensor for electronic industry, IC temperature sensor, radiation temperature sensor of surface acoustic wave, optical fiber temperature sensor, a polyelectrolyte film humidity sensor, semiconductor pressure sensor for industrial instrumentation, silicon integration pressure sensor, thick film humidity sensor and its application, photo sensor reflection type, and color sensor. It also deals with sensor for FA, sensor for a robot and sensor for the chemical industry.

  7. Practical Use Technique of Sensor

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Gyu Seop

    1985-11-15

    This book tells of practical use technology of sensor, introducing the recent trend of sensor for electronic industry, IC temperature sensor, radiation temperature sensor of surface acoustic wave, optical fiber temperature sensor, a polyelectrolyte film humidity sensor, semiconductor pressure sensor for industrial instrumentation, silicon integration pressure sensor, thick film humidity sensor and its application, photo sensor reflection type, and color sensor. It also deals with sensor for FA, sensor for a robot and sensor for the chemical industry.

  8. Sun protection and skin self-examination in melanoma survivors.

    Science.gov (United States)

    Mujumdar, Urvi J; Hay, Jennifer L; Monroe-Hinds, Yvette C; Hummer, Amanda J; Begg, Colin B; Wilcox, Homer B; Oliveria, Susan A; Berwick, Marianne

    2009-10-01

    Patients diagnosed with melanoma are at risk for developing recurrent and second primary disease. Skin self-examination (SSE) and sun protection are standard clinical recommendations to minimize risk. In this study we examined performance of these behaviors in individuals with melanoma drawn from the general population. Potential participants (N=148) with a first primary melanoma diagnosed in 2000 were identified through a population-based cancer registry in New Jersey, USA. One hundred and fifteen individuals participated in a 30 min telephone interview concerning behavioral adherence with SSE and sun protection, self-efficacy for performing these behaviors, and perceived risk of developing another skin cancer. We utilized logistic regression to estimate potential associations of demographic, medical, and psychosocial factors with SSE and sun protection, respectively. Seventeen percent of subjects reported performing comprehensive SSE at least once every two months and 23% engaged in regular sun protection. Utilization of SSE was related to the presence of moles (OR=4.2, 95% CI: 1.1-15) and higher SSE self-efficacy (OR=14.4, 95% CI: 1.9-112). Regular sun protection was related to older age (>60 years; OR=3.3, 95% CI: 1.3-8.7), being female (OR=2.8, 95% CI: 1.1-7.3), and higher sun protection self-efficacy (OR=5.0, 95% CI: 1.4-18). These factors remained significant in multivariate models. In this group of primary melanoma survivors, the rates of SSE and sun protection are comparable to, but do not exceed, general population estimates. This study provides justification for further research to address barriers to prevention and control behaviors in melanoma survivors.

  9. Rancang Bangun Solar Tracker Berbasis Mikrokontroler Atmega8535 Dengan Sensor Ldr Dan Penampil Lcd

    OpenAIRE

    Syafrialdi, Roni; -, Wildian

    2015-01-01

    This research aims to design a solar tracker using a four-quadrant LDR that used for sensing the position of the sun. Solar tracker is the tools used to follow the direction of motion of the sun. The electronic circuits consisting of a power supply circuit, microcontroller ATmega8535 and LCD circuit, stepper motor driver circuit and LDR sensor circuit. The mechanical design using dual axis with stepper motor as an actuator to position the solar cell tilted appropriately to face the sun direct...

  10. Measurement of wall thickness with electrodynamic test heads

    International Nuclear Information System (INIS)

    Koch, R.; Maurer, A.

    1993-01-01

    Starting from the boundary conditions fixed by the physical properties of the electromagnetic/acoustic conversion and the operating limits which result from these for the sensors used, the use of electro-dynamic ultrasonic transducers for measuring wall thickness and double checks in plants for automatic production inspection and production control is shown. The sensor itself is the heart of a test system, but only the equipment and plant concepts surrounding the sensor make economic solution of the test problem possible. The quality of the signals which are supplied by a sensor, determines the quality of a test system. This can only be achieved by optimising all parts of a complex automatic test rig, such as the test head, mechanics, electronics and evaluation for the test problem concerned. (orig./HP) [de

  11. Chemical sensor

    Science.gov (United States)

    Rauh, R. David (Inventor)

    1990-01-01

    A sensor for detecting a chemical substance includes an insertion element having a structure which enables insertion of the chemical substance with a resulting change in the bulk electrical characteristics of the insertion element under conditions sufficient to permit effective insertion; the change in the bulk electrical characteristics of the insertion element is detected as an indication of the presence of the chemical substance.

  12. Load sensor

    NARCIS (Netherlands)

    Van den Ende, D.; Almeida, P.M.R.; Dingemans, T.J.; Van der Zwaag, S.

    2007-01-01

    The invention relates to a load sensor comprising a polymer matrix and a piezo-ceramic material such as PZT, em not bedded in the polymer matrix, which together form a compos not ite, wherein the polymer matrix is a liquid crystalline resin, and wherein the piezo-ceramic material is a PZT powder

  13. Gas sensor

    Science.gov (United States)

    Schmid, Andreas K.; Mascaraque, Arantzazu; Santos, Benito; de la Figuera, Juan

    2014-09-09

    A gas sensor is described which incorporates a sensor stack comprising a first film layer of a ferromagnetic material, a spacer layer, and a second film layer of the ferromagnetic material. The first film layer is fabricated so that it exhibits a dependence of its magnetic anisotropy direction on the presence of a gas, That is, the orientation of the easy axis of magnetization will flip from out-of-plane to in-plane when the gas to be detected is present in sufficient concentration. By monitoring the change in resistance of the sensor stack when the orientation of the first layer's magnetization changes, and correlating that change with temperature one can determine both the identity and relative concentration of the detected gas. In one embodiment the stack sensor comprises a top ferromagnetic layer two mono layers thick of cobalt deposited upon a spacer layer of ruthenium, which in turn has a second layer of cobalt disposed on its other side, this second cobalt layer in contact with a programmable heater chip.

  14. 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

  15. Silva as the Head

    DEFF Research Database (Denmark)

    Svabo, Connie

    2015-01-01

    The head of the performance design programme is substituted by a sister's academy delegate. this performance situation formed part of a week of semesterstart where the students and professors visited Sister's Academy, Malmø. I participated in the Sister's Academy as visiting researcher and here i...

  16. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician Resources Professions Site Index A-Z Computed Tomography (CT) - Head ...

  17. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... are present in the paranasal sinuses. plan radiation therapy for cancer of the brain or other tissues. guide the ... RTAnswers.org Radiation Therapy for Brain Tumors Radiation Therapy for Head and Neck Cancer Others American Stroke Association National Stroke Association top ...

  18. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... full size with caption Pediatric Content Some imaging tests and treatments have special pediatric considerations. The teddy bear denotes child-specific content. Related Articles and Media Radiation Dose in X-Ray and CT Exams Blood Clots CT Perfusion of the Head CT Angiography ( ...

  19. The Twente humanoid head

    NARCIS (Netherlands)

    Reilink, Rob; Visser, L.C.; Bennik, J.; Carloni, Raffaella; Brouwer, Dannis Michel; Stramigioli, Stefano

    2009-01-01

    This video shows the results of the project on the mechatronic development of the Twente humanoid head. The mechanical structure consists of a neck with four degrees of freedom (DOFs) and two eyes (a stereo pair system) which tilt on a common axis and rotate sideways freely providing a three more

  20. 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

  1. Invariant Solar Sail Formations in Elliptical Sun-Synchronous Orbits

    Science.gov (United States)

    Parsay, Khashayar

    Current and past missions that study the Earth's geomagnetic tail require multiple spacecraft to fly in formation about a highly eccentric Keplerian reference orbit that has its apogee inside a predefined science region of interest. Because the geomagnetic tail is directed along the Sun-Earth line and therefore rotates annually, inertially fixed Keplerian orbits are only aligned with the geomagnetic tail once per year. This limitation reduces the duration of the science phase to less than a few months annually. Solar sails are capable of creating non-Keplerian, Sun-synchronous orbits that rotate with the geomagnetic tail. A solar sail flying in a Sun-synchronous orbit will have a continuous presence in the geomagnetic tail throughout the entire year, which significantly improves the in situ observations of the magnetosphere. To achieve a Sun-synchronous orbit, a solar sail is required to maintain a Sun-pointing attitude, which leads to the artificial precession of the orbit apse line in a Sun-synchronous manner, leaving the orbit apogee inside the science region of interest throughout entire the year. To study the spatial and temporal variations of plasma in the highly dynamic environment of the magnetosphere, multiple spacecraft must fly in a formation. The objective for this dissertation is to investigate the feasibility of solar sail formation flying in the Earth-centered, Sun-synchronous orbit regime. The focus of this effort is to enable formation flying for a group of solar sails that maintain a nominally fixed Sun-pointing attitude during formation flight, solely for the purpose of precessing their orbit apse lines Sun-synchronously. A fixed-attitude solar sail formation is motivated by the difficulties in the simultaneous control of orbit and attitude in flying solar sails. First, the secular rates of the orbital elements resulting from the effects of solar radiation pressure (SRP) are determined using averaging theory for a Sun-pointing attitude sail

  2. 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

  3. Head injury in children

    International Nuclear Information System (INIS)

    Sugiura, Makoto; Mori, Nobuhiko; Yokosuka, Reiko; Yamamoto, Masaaki; Imanaga, Hirohisa

    1981-01-01

    Findings of computerized tomography (CT) in 183 cases of head injury in children were investigated with special reference to CT findings of mild head injury. As was expected, CT findings of mild head injury fell within the normal range, in almost all cases. However, abnormal findings were noticed in 4 out of 34 cases (12%) in acute stage and 7 out of 76 cases (9%) in chronic stage. They were 3 cases of localized low density area in acute stage and 6 cases of mild cerebral atrophy in chronic stage, etc. There were some cases of mild head injury in which CT findings were normal while EEG examination revealed abnormality. Also in some cases, x-ray study demonstrated linear skull fracture which CT failed to show. These conventional techniques could be still remained as useful adjunct aid in diagnosis of head injury. CT findings of cases of cerebral contusion in their acute stage were divided as follows; normal, low density, small ventricle and ventricular and/or cisternal hemorrhage, frequency of incidence being 38, 17, 22, 11% respectively. These findings were invariably converted to cerebral atrophy from 10 days to 2 months after the impacts. In the cases with intracranial hematoma revealed by CT, only 32% of them showed clinical signs of Araki's type IV in their acute stage and 63% of them showed no neurological defects, that is Araki's type I and II. A case of extreme diffuse cerebral atrophy which followed acute subdural hematoma caused by tear of bridging veins without cortical contusion was presented. (author)

  4. 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.

  5. 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...

  6. Determination of the decameter wavelength spectrum of the quiet sun

    International Nuclear Information System (INIS)

    Erickson, W.C.; Gergely, T.E.; Kundu, M.R.; Mahoney, M.J.

    1977-01-01

    The Teepee Tee array of the Clark Lake Radio Observatory has been used to compare the flux of the Sun with that of the sidereal sources Tau A and Vir A at several frequencies in the range 109.0-19.0 MHz. Only the two central banks of the E-W arm of the array were used as elements of a phase switched interferometer so that the Sun could be observed as a point souce and compared directly to the sidereal sources. The Sun was still partially resolved however, and appropriate corrections for this effect were made. The observations were taken at times when the Sun and either Tau A or Vir A were at the same declination. The authors have therefore been able to derive the values for the solar flux, without having to resort to a gain vs zenith distance correction. The observations, combined with those available in the literature, allow an accurate derivation of the meter and decameter wavelength spectrum of the quiet Sun. (Auth.)

  7. The Sun/Earth System and Space Weather

    Science.gov (United States)

    Poland, Arthur I.; Fox, Nicola; Lucid, Shannon

    2003-01-01

    Solar variability and solar activity are now seen as significant drivers with respect to the Earth and human technology systems. Observations over the last 10 years have significantly advanced our understanding of causes and effects in the Sun/Earth system. On a practical level the interactions between the Sun and Earth dictate how we build our systems in space (communications satellites, GPS, etc), and some of our ground systems (power grids). This talk will be about the Sun/Earth system: how it changes with time, its magnetic interactions, flares, the solar wind, and how the Sun effects human systems. Data will be presented from some current spacecraft which show, for example, how we are able to currently give warnings to the scientific community, the Government and industry about space storms and how this data has improved our physical understanding of processes on the Sun and in the magnetosphere. The scientific advances provided by our current spacecraft has led to a new program in NASA to develop a 'Space Weather' system called 'Living With a Star'. The current plan for the 'Living With a Star' program will also be presented.

  8. Where were you when the sun went out?

    Science.gov (United States)

    1999-11-01

    strangest thing happened. Just as totality approached the cloud above seemed to thin out, enabling us to see the whole event. We watched in amazement as the last thin bright patch disappeared. There were cheers, horns sounding and applause as the full spectacle was revealed before us - two full minutes of totality. I took photographs through a 600 mm mirror lens, cursing the instability of my flimsy tripod but able to see prominences in some detail. Despite my forward planning the 36 exposure film ran out just as last contact appeared. The excitement of the event prevented any serious, logical and measured photography. I just fired away. As soon as last contact had passed, the clouds reformed and neither Sun nor Moon were seen again until later that afternoon. We had witnessed what is apparently known as the `Red Sea effect' and is caused by the localized cooling due to the umbral shadow `punching' a hole in the cloud cover. The event left us speechless, moved and tearful. Words seemed so inadequate. I had given a number of presentations leading up to this event but nothing could have prepared me for the experience of totality. Darkness came upon us so quickly that we were taken by surprise. Looking up above our heads meant that few of us had noticed the horizon. Friends who were not so lucky with the weather remarked on the beauty of the illuminated horizon. For us it was the nearest thing to a miracle we had ever seen. Roll on 2001! Helen Reynolds writes: My memory of the eclipse will be of lying in a field on a cliff in France staring out to sea. No-one prepares you for the moment of totality; the hairs on the back of your neck literally stand on end. This is not normal. The speed with which darkness falls is frightening. It is inconceivable that minutes ago there was 95%+ coverage of the Sun - the Moon seemed to have no effect and then, suddenly in all senses of the word, darkness literally falls from the sky. The sounds are unreal and the colours are nothing you have

  9. A single magnetic nanocomposite cilia force sensor

    KAUST Repository

    Alfadhel, Ahmed

    2016-04-20

    The advancements in fields like robotics and medicine continuously require improvements of sensor devices and more engagement of cooperative sensing technologies. For example, instruments such as tweezers with sensitive force sensory heads could provide the ability to sense a variety of physical quantities in real time, such as the amount and direction of the force applied or the texture of the gripped object. Force sensors with such abilities could be great solutions toward the development of smart surgical tools. In this work, a unique force sensor that can be integrated at the tips of robotic arms or surgical tools is reported. The force sensor consists of a single bioinspired, permanent magnetic and highly elastic nanocomposite cilia integrated on a magnetic field sensing element. The nanocomposite is prepared from permanent magnetic nanowires incorporated into the highly elastic polydimethylsiloxane. We demonstrate the potential of this concept by performing several experiments to show the performance of the force sensor. The developed sensor element has a 200 μm in diameter single cilium with 1:5 aspect ratio and shows a detection range up to 1 mN with a sensitivity of 1.6 Ω/mN and a resolution of 31 μN. The simple fabrication process of the sensor allows easy optimization of the sensor performance to meet the needs of different applications.

  10. A single magnetic nanocomposite cilia force sensor

    KAUST Repository

    Alfadhel, Ahmed; Khan, Mohammed Asadullah; Cardoso, Susana; Kosel, Jü rgen

    2016-01-01

    The advancements in fields like robotics and medicine continuously require improvements of sensor devices and more engagement of cooperative sensing technologies. For example, instruments such as tweezers with sensitive force sensory heads could provide the ability to sense a variety of physical quantities in real time, such as the amount and direction of the force applied or the texture of the gripped object. Force sensors with such abilities could be great solutions toward the development of smart surgical tools. In this work, a unique force sensor that can be integrated at the tips of robotic arms or surgical tools is reported. The force sensor consists of a single bioinspired, permanent magnetic and highly elastic nanocomposite cilia integrated on a magnetic field sensing element. The nanocomposite is prepared from permanent magnetic nanowires incorporated into the highly elastic polydimethylsiloxane. We demonstrate the potential of this concept by performing several experiments to show the performance of the force sensor. The developed sensor element has a 200 μm in diameter single cilium with 1:5 aspect ratio and shows a detection range up to 1 mN with a sensitivity of 1.6 Ω/mN and a resolution of 31 μN. The simple fabrication process of the sensor allows easy optimization of the sensor performance to meet the needs of different applications.

  11. Head and Neck Cancer Treatment

    Science.gov (United States)

    ... Professions Site Index A-Z Head and Neck Cancer Treatment Head and neck cancer overview What are my ... and neck cancer. For updated information on new cancer treatments that are available, you should discuss these issues ...

  12. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... for Brain Tumors Radiation Therapy for Head and Neck Cancer Others : American Stroke Association National Stroke Association ... MRA) Magnetic Resonance, Functional (fMRI) - Brain Head and Neck Cancer Treatment Brain Tumor Treatment Magnetic Resonance Imaging ( ...

  13. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... are the limitations of MRI of the Head? What is MRI of the Head? Magnetic resonance imaging ( ... brain) in routine clinical practice. top of page What are some common uses of the procedure? MR ...

  14. Head, Neck, and Oral Cancer

    Medline Plus

    Full Text Available ... and Neck Pathology Oral, Head and Neck Pathology Close to 49,750 Americans will be diagnosed with ... and Neck Pathology Oral, Head and Neck Pathology Close to 49,750 Americans will be diagnosed with ...

  15. Head Lice: Prevention and Control

    Science.gov (United States)

    ... and General Public. Contact Us Parasites Home Prevention & Control Language: English (US) Español (Spanish) Recommend on Facebook ... that can be taken to help prevent and control the spread of head lice: Avoid head-to- ...

  16. Continuous liquid level monitoring sensor system using fiber Bragg grating

    Science.gov (United States)

    Sengupta, Dipankar; Kishore, Putha

    2014-01-01

    The design and packaging of simple, small, and low cost sensor heads, used for continuous liquid level measurement using uniformly thinned (etched) optical fiber Bragg grating (FBG) are proposed. The sensor system consists of only an FBG and a simple detection system. The sensitivity of sensor is found to be 23 pm/cm of water column pressure. A linear optical fiber edge filter is designed and developed for the conversion of Bragg wavelength shift to its equivalent intensity. The result shows that relative power measured by a photo detector is linearly proportional to the liquid level. The obtained sensitivity of the sensor is nearly -15 mV/cm.

  17. 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 ...

  18. Sun Safety Practices Among Schools in the United States.

    Science.gov (United States)

    Everett Jones, Sherry; Guy, Gery P

    2017-05-01

    Exposure to the sun's UV radiation is a leading cause of skin cancer. Positive attitudes and beliefs about sun safety behavior, which would make sun protective behavior more likely, could be promoted and supported by school policies and practices. To identify school characteristics associated with having adopted practices that promote sun safety. School-level data from the February 3 to July 23, 2014, School Health Policies and Practices Study's Healthy and Safe School Environment questionnaire were analyzed. The School Health Policies and Practices Study uses a 2-stage sampling design to select a nationally representative sample of schools. All public, state-administered, Catholic, and non-Catholic private schools with any of the grades from kindergarten through 12 were eligible for inclusion. All analyses were conducted using weighted data. Prevalence of sun safety practices. In a nationally representative sample of 828 US schools, representatives of 577 schools (69.7%) responded. Overall, sun safety practices were not common among schools. The most frequent practice was having teachers allow time for students to apply sunscreen at school (47.6%; 95% CI, 42.4%-52.9%). Few schools made sunscreen available for students to use (13.3%; 95% CI, 10.2%-17.0%), almost always or always scheduled outdoor activities to avoid times when the sun was at peak intensity (15.0%; 95% CI, 11.4%-19.6%), or asked parents to ensure that students applied sunscreen before school (16.4%; 95% CI, 12.9%-20.6%). High schools were less likely than elementary schools and middle schools to adopt several practices: for instance, 37.5% of high schools (95% CI, 29.7%-46.0%), 51.6% of middle schools (95% CI, 43.3%-59.7%), and 49.5% of elementary schools (95% CI, 42.0%-57.0%) had teachers allow time for students to apply sunscreen at school, and 11.8% of high schools (95% CI, 7.7%-17.5%), 18.2% of middle schools (95% CI, 13.3%-24.4%), and 14.7% of elementary schools (95% CI, 9.6%-21.8%) almost

  19. 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

  20. Sun and Shade leaves, SIF, and Photosynthetic Capacity

    Science.gov (United States)

    Berry, J. A.; Badgley, G.

    2016-12-01

    Recent advances in retrieval of solar induced chlorophyll fluorescence (SIF) have opened up new possibilities for remote sensing of canopy physiology and structure. To date most of the emphasis has been placed on SIF as an indicator of stress and photosynthetic capacity. However, it is clear that canopy structure can also have an influence. To this point, simulations of SIF in land surface models tend to under predict observed variation in SIF. Also, large, systematic differences in SIF from different canopy types seem to correlate well with the photosynthetic capacity of these canopies. SIF emissions from pampered crops can be several-fold that from evergreen, needle-leaf forests. Yet, these may have similar vegetation indices and absorb a similar fraction of incident PAR. SIF photons produced in a conifer canopy do have a lower probability of escaping its dense, clumped foliage. However, this does not explain the correlated differences in photosynthetic rate and SIF. It is useful, in this regard, to consider the separate contributions of sun and shade leaves to the SIF emitted by a canopy. Sun leaves tend to be displayed to intercept the direct solar beam, and these highly illuminated leaves are often visible from above the canopy. Sun leaves produce more SIF and a large fraction of it escapes. Therefore, the intensity of SIF may be a sensitive indicator of the partitioning of absorbed PAR to sun and shade leaves. Many models account tor the different photosynthetic capacity of sun and shade leaves in calculating canopy responses. However, the fraction of leaves in each category is usually parameterized by an assumed leaf angle distribution (e.g. spherical). In reality, the sun/shade fraction can vary over a wide range, and it has been difficult to measure. SIF and possibly near-IR reflectance of canopies can be used to specify this key parameter with obvious importance to understanding photosynthetic rate.